Evaluating angular ion current density for atomically defined nanotips - Urban, R.; Wolkow, R.A.; Pitters, J.L. (Microscopy and Microanalysis, 2014)
In this paper we investigate methods to characterize angular current density from atomically defined gas field ion sources. We show that the ion beam emitted from a single apex atom is described by a two-dimensional Gaussian profile. Owing to the Gaussian shape of the beam and the requirement to collect the majority of the ion current, fixed apertures have inhomogeneous illumination. Therefore, angular current density measurements through a fixed aperture record averaged angular current density. This makes comparison of data difficult as averaged angular current density depends on aperture size. For the same reasons, voltage normalization cannot be performed for fixed aperture measurements except for aperture sizes that are infinitely small. Consistent determination of angular current density and voltage normalization, however, can be achieved if the beam diameter as well as total ion current are known. In cases where beam profile cannot be directly imaged with a field ion microscope, the beam profile could be extracted from measurements taken at multiple acceleration voltages and/or with multiple aperture sizes. © Microscopy Society of America 2014.

Nano-dot markers for electron tomography formed by electron beam-induced deposition: Nanoparticle agglomerates application - Hayashida, M.; Malac, M.; Bergen, M.; Li, P. (Ultramicroscopy, 2014)
A method allowing fabrication of nano-dot markers for electron tomography was developed using an electron beam-induced deposition in an ordinary dual beam instrument (FIB and SEM) or an SEM. The electron beam deposited nano-dot markers are suitable for automatic alignment of tomographic series. The accuracy of the alignment was evaluated and the method was demonstrated on agglomerated nanoparticle samples using a rod-shaped sample with no missing wedge effect. Simulations were used to assess the effect of marker size on alignment accuracy. © 2014.
Keywords: Electron tomography; Nanoparticle agglomerate; Electron beam induced deposition; Fiducial marker; Nano-dot marker; FIB sample preparation

Wine yeast typing by MALDI-TOF MS - Usbeck, J.C.; Wilde, C.; Bertrand, D.; Behr, J.; Vogel, R.F. (Applied Microbiology and Biotechnology, 2014)
For the production of wine, the most important industrially used yeast species is Saccharomyces cerevisiae. Years of experience have shown that wine quality and property are significantly affected by the employed strain conducting the fermentation. Consequently, the ability of a strain level differentiation became an important requirement of modern winemaking. In our study, we showed that the differentiation by time-consuming and laborious biochemical and DNA-based methods to enable a constant beverage quality and characteristics can be replaced by matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), accompanied by the additional benefit of an application prediction. Mass fingerprints of 33 Saccharomyces strains, which are commonly used for varying wine fermentations, were generated by MALDI-TOF MS upon optimized sample preparation and instrument settings and analyzed by a cluster analysis for strain or ecotype-level differentiation. As a reference method, delta-PCR was chosen to study the genetic diversity of the employed strains. Finally, the cluster analyses of both methods were compared. It could be shown that MALDI-TOF MS, acting at proteome level, provides valuable information about the relationship between yeast strains and their application potential according to their MALDI mass fingerprint. © 2014 Springer-Verlag Berlin Heidelberg.
Keywords: Yeast; MALDI TOF MS; Time of flight mass spectrometry; Wine fermentation; Candida krusei; Saccharomyces bayanus; Saccharomyces cerevisiae; Saccharomyces uvarum

Validity of the dipole approximation in TEM-EELS studies - Egerton, R.F.; Mcleod, R.A.; Malac, M. (Microscopy Research and Technique, 2014)
Nondipole effects in electron energy-loss spectroscopy are evaluated in terms of deviation of the inelastic scattering from a Lorentzian angular distribution, which is assumed in established procedures for plural-scattering deconvolution, thickness measurement, and Kramers-Kronig analysis. The deviation appears to be small and may be outweighed by the effect of plural (elastic+inelastic) scattering, which is not removed by conventional deconvolution methods. In the core-loss region of the spectrum, non-Lorentzian behaviour stems from a reduction of the generalized oscillator strength from its optical value and (for energies far above an ionization threshold) formation of a Bethe-ridge angular distribution. At incident energies above 200 keV, retardation effects further distort the angular dependence, even for core losses just above threshold. With an on-axis collection aperture, non-dipole effects are masked by the rapid falloff of intensity with scattering angle, but they may become important for off-axis measurements. Near-edge fine structure is sensitive to nondipole effects but these can be minimized by use of an angle-limiting collection aperture. © 2014 Wiley Periodicals, Inc.
Keywords: EELS; nondipole; Lorentzian angular distribution

Immersed boundary solution of natural convection in a square cavity with an enclosed rosette-shaped hot cylinder - Ilinca, F.; Hétu, J.-F. (Numerical Heat Transfer; Part A: Applications, 2014)
Numerical solutions are shown for the natural convection flow inside a cold square enclosure with a hot rosette-shaped cylinder inside. Solutions are obtained using an immersed-boundary finite element method. The study investigates the effect of the rosette-shape factor on the heat transfer and fluid flow for Rayleigh numbers between 103 and 107. Results indicate the formation of recirculation cells of number, size, and location depending strongly on the shape of the cylinder and on the Rayleigh number. All solutions reach a steady state, except when the rosette-shape factor is 0.6 at Ra = 106, for which a periodic transient solution is obtained. © 2014 Taylor and Francis Group, LLC.
Keywords: Natural convection; Heat transfer and fluid flow; Immersed boundary; Natural convection flow; Numerical solution; Rayleigh number; Recirculation cells; Square enclosures; Transient solutions; Cylinders (shapes)

Transition between mechanisms of laser-induced field-free molecular orientation - Znakovskaya, I.; Spanner, M.; De, S.; Li, H.; Ray, D.; Corkum, P.; Litvinyuk, I. V.; Cocke, C. L.; Kling, M. F. (Physical Review Letters, 2014)
The transition between two distinct mechanisms for the laser-induced field-free orientation of CO molecules is observed via measurements of orientation revival times and subsequent comparison to theoretical calculations. In the first mechanism, which we find responsible for the orientation of CO up to peak intensities of 8×1013 W/cm2, the molecules are impulsively oriented through the hyperpolarizability interaction. At higher intensities, asymmetric depletion through orientation-selective ionization is the dominant orienting mechanism. In addition to the clear identification of the two regimes of orientation, we propose that careful measurements of the onset of the orientation depletion mechanism as a function of the laser intensity will provide a relatively simple route to calibrating absolute rates of nonperturbative strong-field molecular ionization. © 2014 American Physical Society.
Keywords: Depletion mechanism; Field-free orientation; Hyper-polarizability; Laser intensities; Measurements of; Molecular ionization; Nonperturbative; Theoretical calculations; Ionization; Molecules; Molecular orientation

Ethanol extract of Liuwei Dihuang reduces weight gain and visceral fat in obese-prone CD rats fed a high-fat diet - Nair, Sandhya V. G.; Zhang, Junzeng; Wang, Yanwen (Experimental Biology and Medicine, 2014)
The current study investigated the effect and mechanisms of action of Liuwei Dihuang ethanol extract (LWDH-EE) on obesity and related metabolic phenotypes in male obese-prone CD rats. The rats were fed a high-fat diet and treated with 0 (obese control), 350 (EE350), or 700 (EE700) mg/kg/d of LWDH-EE in water once a day by gavage feeding for 10 weeks. The EE700 decreased body weight after 3 weeks of the treatment and the effect was maintained throughout the remaining study period. The EE700 also significantly reduced visceral fat and improved metabolic phenotypes by lowering the serum total cholesterol (T-C), non-high-density lipoprotein cholesterol, triacylglycerol, free fatty acids (FFA), and leptin levels. The EE350 reduced epididymal fat, serum T-C, and FFA but did not significantly affect other parameters. LWDH-EE dose-dependently increased fat and carbohydrate oxidations, energy expenditure, and the relative efficiency of fat oxidation for energy expenditure. EE350 and EE700 reduced food intake only in week 5 and did not affect the accumulative food intake in every week and the entire treatment period. Taken together, the results suggest that LWDH-EE is a potential therapeutic agent for the prevention of obesity possibly through a primary action of increasing energy metabolism and expenditure, along with a possible effect of decreasing energy intake.
Keywords: blood lipids; energy expenditure; hormones; Liuwei Dihuang ethanol extract; obese rats; visceral fat; weight gain

Comparing m31 and milky way satellites: The extended star formation histories of andromeda - Weisz, D.R.; Skillman, E.D.; Hidalgo, S.L.; Monelli, M.; Dolphin, A.E.; McConnachie, A.; Bernard, E.J.; Gallart, C.; Aparicio, A.; Boylan-Kolchin, M.; Cassisi, S.; Cole, A.A.; et al. (The Astrophysical Journal, 2014)
We present the first comparison between the lifetime star formation histories (SFHs) of M31 and Milky Way (MW) satellites. Using the Advanced Camera for Surveys on board the Hubble Space Telescope, we obtained deep optical imaging of Andromeda II (And II; MV = -12.0; log(M /M⊙) ∼ 6.7) and Andromeda XVI (And XVI; MV = -7.5; log(M /M⊙) ∼ 4.9) yielding color-magnitude diagrams that extend at least 1 mag below the oldest main-sequence turnoff, and are similar in quality to those available for the MW companions. And II and And XVI show strikingly similar SFHs: both formed 50%-70% of their total stellar mass between 12.5 and 5 Gyr ago (z ∼ 5-0.5) and both were abruptly quenched ∼5 Gyr ago (z ∼ 0.5). The predominance of intermediate age populations in And XVI makes it qualitatively different from faint companions of the MW and clearly not a pre-reionization fossil. Neither And II nor And XVI appears to have a clear analog among MW companions, and the degree of similarity in the SFHs of And II and And XVI is not seen among comparably faint-luminous pairs of MW satellites. These findings provide hints that satellite galaxy evolution may vary substantially among hosts of similar stellar mass. Although comparably deep observations of more M31 satellites are needed to further explore this hypothesis, our results underline the need for caution when interpreting satellite galaxies of an individual system in a broader cosmological context. © 2014. The American Astronomical Society. All rights reserved.

Thermodynamic post-processing versusGC-content pre-processing for DNA codessatisfying the hamming distance and reverse-complement constraints - Tulpan, D.; Smith, D.H.; Montemanni, R. (IEEE/ACM Transactions on Computational Biology and Bioinformatics, 2014)
Stochastic, meta-heuristic and linear construction algorithms for the design of DNA strands satisfying Hamming distance and reverse-complement constraints often use a GC-content constraint to pre-process the DNA strands. Since GC-content is a poor predictor of DNA strand hybridization strength the strands can be filtered by post-processing using thermodynamic calculations. An alternative approach is considered here, where the algorithms are modified to remove consideration of GC-content and rely on post-processing alone to obtain large sets of DNA strands with satisfactory melting temperatures. The two approaches (pre-processing GC-content and post-processing melting temperatures) are compared and are shown to be complementary when large DNA sets are desired. In particular, the second approach can give significant improvements when linear constructions are used. © 2014 IEEE.
Keywords: Algorithms; Bioinformatics; DNA; Hamming distance; Melting point; Stochastic systems; Construction algorithms; DNA design; Linear codes; Post processing; Pre-processing; reverse-complement; Stochastic local searches; Thermodynamic calculations; Gene encoding

Investigation of the scaling law on gelation of oppositely charged nanocrystalline cellulose and polyelectrolyte - Lu, A.; Wang, Y.; Boluk, Y. (Carbohydrate Polymers, 2014)
The sol-gel transition in the mixture system of oppositely charged polyelectrolyte (quaternized hydroxyethylcellulose ethoxylate, QHEC) and nanocrystalline cellulose (NCC) induced by electrostatic adsorption interaction was investigated by rheological means. Winter and Chambon theory was validated to be applicable for the critical gel point determination, and critical gel point have been successfully determined. With QHEC concentration increasing, more NCC were needed to form a critical gel, and smaller loss tangent and relaxation exponent (n) values at the gel point were observed, indicating the elastic nature of mixture was enhanced with QHEC increase. Gel strength behaved as a function of both QHEC and NCC concentrations, suggesting the gel network at the critical point was composed of entanglements and association of QHEC macromolecular chains, as well as the electrostatic adsorption interaction between QHEC chains and NCC rods. The calculated number of NCC rods per junction decreased from 0.30 to 0.01 when the QHEC concentration increased from 1.0 wt% to 3.0 wt%, indicating the electrostatic adsorption interaction between the NCC rods and QHEC chains was less significant to gel formation at higher QHEC concentrations. Therefore, the exponents of scaling law η0 ∝ ∈-γ and Ge ∝ ∈z for the QHEC/NCC mixtures revealed that the scaling law n = z/(z + γ) between n, γ, and z was only feasible at highest QHEC concentration, since the intermolecular interaction (electrostatic adsorption interaction in this article) was so weak that can be neglected and the critical gel network was dominated by QHEC chain entanglements and association. © 2014 Elsevier Ltd.

Radiative heat transfer in the core of axisymmetric pool fires - I: Evaluation of approximate radiative property models - Consalvi, J.L.; Liu, F. (International Journal of Thermal Sciences, 2014)
Radiative heat transfer calculations are conducted in two laboratory-scale axisymmetric methane pool fires generated on a burner of 0.38 m diameter with heat release rates (HRR) of 34 and 176 kW by using the 'exact' Line-By-Line (LBL) method, the narrow band correlated-k (NBCK) model, the full-spectrum correlated-k (FSCK) model, the multi-scale full-spectrum k-distribution (MSFSK) model, and a grey wide-band model (WBM). For each radiative model the corresponding absorption coefficients for carbon dioxide, water vapor, carbon monoxide and methane are generated from the same high-resolution spectroscopic database. Model results show that the contribution of carbon monoxide can be neglected whereas that of methane increases with HRR. In addition, the grey approximation for soot holds for these weakly sooting flames. Comparisons with LBL solutions show that WBM fails to predict accurately the radiative heat transfer through the fuel rich core. The FSCK model presents the best compromise in terms of accuracy and computational efficiency for the 34 kW pool fire. However, significant discrepancies are observed for the 176 kW pool fire where the strong attenuation of radiation by methane invalidates the 'correlated' assumption of the absorption coefficient. MSFSK and NBCK models provide very accurate predictions, with the MSFSK model being more efficient when overlap parameters are tabulated as a function of temperature and composition. © 2014 Elsevier Masson SAS. All rights reserved.
Keywords: Absorption spectroscopy; Carbon dioxide; Carbon monoxide; Heat radiation; Methane; Plasma diagnostics; Radiative transfer; Absorption co-efficient; Gas radiative properties; Heat Release Rate (HRR); K distribution; Pool fires; Radiative heat transfer; Radiative property models; Spectroscopic database; Fire protection

A 115In solid-state NMR study of low oxidation-state indium complexes - Hamaed, H.; Johnston, K.E.; Cooper, B.F.T.; Terskikh, V.V.; Ye, E.; Macdonald, C.L.B.; Arnold, D.C.; Schurko, R.W. (Chemical Science, 2014)
115In solid-state NMR (SSNMR) spectroscopy is applied to characterise a variety of low oxidation-state indium(i) compounds. 115In static wideline SSNMR spectra of several In(i) complexes were acquired with moderate and ultra-high field NMR spectrometers (9.4 and 21.1 T, respectively). 115In MAS NMR spectra were obtained with moderate and ultra-fast (>60 kHz) spinning speeds at 21.1 T. In certain cases, variable-temperature (VT) 115In SSNMR experiments were performed to study dynamic behaviour and phase transitions. The indium electric field gradient (EFG) and chemical shift (CS) tensor parameters were determined from the experimental spectra. With the aid of first principles calculations, the tensor parameters and orientations are correlated to the structure and symmetry of the local indium environments. In addition, calculations aid in proposing structural models for samples where single crystal X-ray structures could not be obtained. The rapidity with which high quality 115In SSNMR spectra can be acquired at 21.1 T and the sensitivity of the 115In NMR parameters to the indium environment suggest that 115In SSNMR is a powerful probe of the local chemical environments of indium sites. This work demonstrates that 115In NMR can be applied to a wide range of important materials for the purpose of increasing our understanding of structures and dynamics at the molecular/atomic level, especially for the characterisation of disordered, microcrystalline and/or multi-valence solids for which crystal structures are unavailable. This journal is © The Royal Society of Chemistry 2014.
Keywords: Chemical environment; Dynamic behaviours; Electric field gradients; Experimental spectra; First-principles calculation; Single crystal x-ray structures; Structural models; Variable temperature; Electric fields; Indium; Nuclear magnetic resonance spectroscopy; Solid state physics; Spectrometers; Tensors; Indium compounds

Surface modification of nonviral nanocarriers for enhanced gene delivery - Fortier, Charles; Durocher, Yves; De Crescenzo, Gregory (Nanomedicine, 2014)
Biomedical nanotechnology has given a new lease of life to gene therapy with the ever-developing and ever-diversifying nonviral gene delivery nanocarriers. These are designed to pass a series of barriers in order to bring their nucleic acid cargo to the right subcellular location of particular cells. For a given application, each barrier has its dedicated strategy, which translates into a physicochemical, biological and temporal identity of the nanocarrier surface. Different strategies have thus been explored to implement adequate surface identities on nanocarriers over time for systemic delivery. In that context, this review will mainly focus on organic nanocarriers, for which these strategies will be described and discussed.
Keywords: biofunctionalization; lateral stabilization; nonviral gene delivery; polymeric coating; responsive teethering; shielding; surface modification

The ACS LCID project. X.The star formation history of IC 1613: revisiting the over-cooling problem - Skillman, E.D.; Hidalgo, S.L.; Weisz, D.R.; Monelli, M.; Gallart, C.; Aparicio, A.; Bernard, E.J.; Boylan-Kolchin, M.; Cassisi, S.; Cole, A.A.; Dolphin, A.E.; Ferguson, H.C.; et al. (The Astrophysical Journal, 2014)
We present an analysis of the star formation history (SFH) of a field near the half-light radius in the Local Group dwarf irregular galaxy IC 1613 based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. Our observations reach the oldest main sequence turn-off, allowing a time resolution at the oldest ages of ∼1 Gyr. Our analysis shows that the SFH of the observed field in IC 1613 is consistent with being constant over the entire lifetime of the galaxy. These observations rule out an early dominant episode of star formation in IC 1613. We compare the SFH of IC 1613 with expectations from cosmological models. Since most of the mass is in place at early times for low-mass halos, a naive expectation is that most of the star formation should have taken place at early times. Models in which star formation follows mass accretion result in too many stars formed early and gas mass fractions that are too low today (the "over-cooling problem"). The depth of the present photometry of IC 1613 shows that, at a resolution of ∼1 Gyr, the star formation rate is consistent with being constant, at even the earliest times, which is difficult to achieve in models where star formation follows mass assembly. © 2014. The American Astronomical Society. All rights reserved.

Microfabrication of passive electronic components with printed graphene-oxide deposition - Sinar, D.; Knopf, G.K.; Nikumb, S. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Flexible electronic circuitry is an emerging technology that will significantly impact the future of healthcare and medicine, food safety inspection, environmental monitoring, and public security. Recent advances in drop-on-demand printing technology and electrically conductive inks have enabled simple electronic circuits to be fabricated on mechanically flexible polymers, paper, and bioresorbable silk. Research has shown that graphene, and its derivative formulations, can be used to create low-cost electrically conductive inks. Graphene is a one atom thick two-dimensional layer composed of carbon atoms arranged in a hexagonal lattice forming a material with very high fracture strength, high Young's Modulus, and low electrical resistance. Non-conductive graphene-oxide (GO) inks can also be synthesized from inexpensive graphite powders. Once deposited on the flexible substrate the electrical conductivity of the printed GO microcircuit traces can be restored through thermal reduction. In this paper, a femtosecond laser with a wavelength of 775nm and pulse width of 120fs is used to transform the non-conductive printed GO film into electrically conductive oxygen reduced graphene-oxide (rGO) passive electronic components by the process of laser assisted thermal reduction. The heat affected zone produced during the process was minimized because of the femtosecond pulsed laser. The degree of conductivity exhibited by the microstructure is directly related to the laser power level and exposure time. Although rGO films have higher resistances than pristine graphene, the ability to inkjet print capacitive elements and modify local resistive properties provides for a new method of fabricating sensor microcircuits on a variety of substrate surfaces. © 2014 SPIE.
Keywords: Capacitive sensors; Composite micromechanics; Elastic moduli; Flexible electronics; Fracture toughness; Ink; Microanalysis; Microelectrodes; Microfabrication; Micromachining; Printing; Technology; Drop-on-demand printing; Electrical conductivity; Electrically conductive; Electrically conductive inks; Environmental Monitoring; Femtosecond pulsed laser; Passive electronic components; Thermal reduction; Graphene

Electricity production from synthesis gas in a multi-electrode microbial fuel cell - Hussain, A.; Raghavan, V.; Guiot, S.R.; Tartakovsky, B. (Journal of Chemical Technology and Biotechnology, 2014)
BACKGROUND: Electricity production in single-anode/cathode MFCs fed with simulated synthesis gas (syngas) as the sole electron donor has recently been demonstrated. This study evaluated the ability of a multi-anode/cathode MFC fed with syngas to achieve improved volumetric efficiency at several operating temperatures and electrode arrangements. RESULTS: A maximum power density of 33 mW LR-1 (normalized to the anodic compartment volume) and a coulombic efficiency (CE) of 43% was achieved at an operating temperature of 37°C. MFC operation at 50°C resulted in a much lower power density of 10 mW LR-1 and a CE of 15%. The MFC power density was greatly impacted by the electrode arrangement and the highest power density was achieved in a three anode-two cathode (3A-2C) arrangement. CONCLUSION: The multi-electrode design enhanced the performance of a syngas-fed MFC, which could have major economic and operational implications for designing large-scale syngas-fed MFCs. The MFC performance at elevated temperatures was restricted by low microbial activity, implying that a thermophilic rather than a mesophilic inoculum might be required for successful operation under thermophilic conditions. © 2013 Society of Chemical Industry.
Keywords: Carbon monoxide; Microbial fuel cells; Temperature; Electricity production; Electrode arrangement; Maximum power density; Multi-electrode; Operating temperature; Synthesis gasses (syngas); Thermophilic conditions; Volumetric efficiency; Synthesis gas; article; economic aspect; electricity; electrode; electron; gas; inoculation; microbial activity; microbial fuel cell; temperature

Reconstructing folding energy landscapes by single-molecule force spectroscopy - Woodside, M.T.; Block, S.M. (Annual Review of Biophysics, 2014)
Folding may be described conceptually in terms of trajectories over a landscape of free energies corresponding to different molecular configurations. In practice, energy landscapes can be difficult to measure. Single-molecule force spectroscopy (SMFS), whereby structural changes are monitored in molecules subjected to controlled forces, has emerged as a powerful tool for probing energy landscapes. We summarize methods for reconstructing landscapes from force spectroscopy measurements under both equilibrium and nonequilibrium conditions. Other complementary, but technically less demanding, methods provide a model-dependent characterization of key features of the landscape. Once reconstructed, energy landscapes can be used to study critical folding parameters, such as the characteristic transition times required for structural changes and the effective diffusion coefficient setting the timescale for motions over the landscape. We also discuss issues that complicate measurement and interpretation, including the possibility of multiple states or pathways and the effects of projecting multiple dimensions onto a single coordinate. Copyright © 2014 by Annual Reviews. All rights reserved.
Keywords: article; conformation; diffusion coefficient; DNA hairpin; energy; equilibrium constant; feedback system; force; measurement; optical tweezers; priority journal; protein folding; protein function; protein structure; signal transduction; single molecule force spectroscopy; spectroscopy; structure activity relation

Chondrus crispus - A present and historical model organism for red seaweeds - Collén, J.; Cornish, M.L.; Craigie, J.; Ficko-Blean, E.; Hervé, C.; Krueger-Hadfield, S.A.; Leblanc, C.; Michel, G.; Potin, P.; Tonon, T.; Boyen, C. (Advances in Botanical Research, 2014)
Chondrus crispus, or Irish moss, is a common edible red seaweed that can be found on rocky shores in the Northern Atlantic. The cell wall contains carrageenan and C. crispus is the original source of this commercially used thickener. Because of the ecological and economic importance of this red alga a relatively important research literature exists and one of the recent achievements in C. crispus research is the sequencing of its genome. In this chapter we review some of the literature with the aim to promote C. crispus as a model organism for florideophyte red seaweeds. We consider subjects like commercial and historical uses, ecology, genetics, population structure, mating systems, physiology, cell wall biology and genomics. © 2014 Elsevier Ltd.

The role of Carboxydothermus hydrogenoformans in the conversion of calcium phosphate from amorphous to crystalline state - Haddad, M.; Vali, H.; Paquette, J.; Guiot, S.R. (PLoS ONE, 2014)
Two previously unknown modes of biomineralization observed in the presence of Carboxydothermus hydrogenoformans are presented. Following the addition of NaHCO3 and the formation of an amorphous calcium phosphate precipitate in a DSMZ medium inoculated with C. hydrogenoformans , two distinct crystalline solids were recovered after 15 and 30 days of incubation. The first of these solids occurred as micrometric clusters of blocky, angular crystals, which were associated with bacterial biofilm. The second solid occurred as 30-50 nm nanorods that were found scattered among the organic products of bacterial lysis. The biphasic mixture of solids was clearly dominated by the first phase. The X-ray diffractometry (XRD) peaks and Fourier transform infrared spectroscopy (FTIR) spectrum of this biphasic material consistently showed features characteristic of Mg-whitlockite. No organic content or protein could be identified by dissolving the solids. In both cases, the mode of biomineralization appears to be biologically induced rather than biologically controlled. Since Mg is known to be a strong inhibitor of the nucleation and growth of CaP, C. hydrogenoformans may act by providing sites that chelate Mg or form complexes with it, thus decreasing its activity as nucleation and crystal growth inhibitor. The synthesis of whitlockite and nano-HAP-like material by C. hydrogenoformans demonstrates the versatility of this organism also known for its ability to perform the water-gas shift reaction, and may have applications in bacterially mediated synthesis of CaP materials, as an environmentally friendly alternative process. © 2014 Haddad et al.
Keywords: bicarbonate; calcium phosphate; hydroxyapatite; magnesium; nanocrystal; nanorod; article; bacteriolysis; biofilm; biomineralization; Carboxydothermus hydrogenoformans; complex formation; controlled study; crystallization; electron microscopy; hyperthermophilic bacterium; infrared spectroscopy; nonhuman; X ray diffraction

Increasing phytoremediation efficiency and reliability using novel omics approaches - Bell, T.H.; Joly, S.; Pitre, F.E.; Yergeau, E. (Trends in Biotechnology, 2014)
Phytoremediation is a cost-effective green alternative to traditional soil remediation technologies, but has experienced varied success in practice. The recent omics revolution has led to leaps in our understanding of soil microbial communities and plant metabolism, and some of the conditions that promote predictable activity in contaminated soils and heterogeneous environments. Combinations of omics tools and new bioinformatics approaches will allow us to understand integrated activity patterns between plants and microbes, and determine how this metaorganism can be modified to maximize growth, appropriate assembly of microbial communities, and, ultimately, phytoremediation activity. Here we provide an overview of how new omics-mediated discoveries can potentially be translated into an effective and reliable environmental technology. © 2014 Etienne Yergeau.
Keywords: Bioinformatics; Microorganisms; Soil conservation; Soil pollution; Metagenomics; Metaorganism; Metatranscriptomics; Next-generation sequencing; Phytoremediation; Bioremediation

Understanding interactions of functionalized nanoparticles with proteins: A case study on lactate dehydrogenase - Stueker, O.; Ortega, V.A.; Goss, G.G.; Stepanova, M. (Small, 2014)
Nanomaterials in biological solutions are known to interact with proteins and have been documented to affect protein function, such as enzyme activity. Understanding the interactions of nanoparticles with biological components at the molecular level will allow for rational designs of nanomaterials for use in medical technologies. Here we present the first detailed molecular mechanics model of functionalized gold nanoparticle (NP) interacting with an enzyme (l-lactate dehydrogenase (LDH) enzyme). Molecular dynamics (MD) simulations of the response of LDH to the NP binding demonstrate that although atomic motions (dynamics) of the main chain exhibit only a minor response to the binding, the dynamics of side chains are significantly constrained in all four active sites that predict alteration in kinetic properties of the enzyme. It is also demonstrated that the 5 nm gold NPs cause a decrease in the maximal velocity of the enzyme reaction (Vmax) and a trend towards a reduced affinity (increased Km) for the β-NAD binding site, while pyruvate enzyme kinetics (Km and Vmax) are not significantly altered in the presence of the gold NPs. These results demonstrate that modeling of NP:protein interactions can be used to understand alterations in protein function. Using molecular dynamic simulations for single, functionalized nanoparticles in solution and a newly developed method of analysis, Stueker and co-workers describe the effects of binding of a mercapto-undecanoic acid functionalized 4.2 nm gold nanoparticle on the structural and dynamic properties of the biological enzyme LDH. The predictions help to explain the experimentally determined alterations in measured LDH enzyme activity when exposed to these particles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords: Biomedical engineering; Chains; Computer simulation; Enzyme activity; Enzyme kinetics; Gold; Medical nanotechnology; Metal nanoparticles; Molecular dynamics; Nanostructured materials; Reaction kinetics; Enzyme functions; Functionalized gold nanoparticles; Functionalized nanoparticles; Lactate dehydrogenase; Molecular dynamics simulations; Molecular simulations; Structural and dynamic properties; toxicology; Proteins

Crystallographic and glycan microarray analysis of human polyomavirus 9 VP1 identifies N-glycolyl neuraminic acid as a receptor candidate - Khan, Z.M.; Liu, Y.; Neu, U.; Gilbert, M.; Ehlers, B.; Feizi, T.; Stehle, T. (Journal of Virology, 2014)
Human polyomavirus 9 (HPyV9) is a closely related homologue of simian B-lymphotropic polyomavirus (LPyV). In order to define the architecture and receptor binding properties of HPyV9, we solved high-resolution crystal structures of its major capsid protein, VP1, in complex with three putative oligosaccharide receptors identified by glycan microarray screening. Comparison of the properties of HPyV9 VP1 with the known structure and glycan-binding properties of LPyV VP1 revealed that both viruses engage short sialylated oligosaccharides, but small yet important differences in specificity were detected. Surprisingly, HPyV9 VP1 preferentially binds sialyllactosamine compounds terminating in 5-N-glycolyl neuraminic acid (Neu5Gc) over those terminating in 5-N-acetyl neuraminic acid (Neu5Ac), whereas LPyV does not exhibit such a preference. The structural analysis demonstrated that HPyV9 makes specific contacts, via hydrogen bonds, with the extra hydroxyl group present in Neu5Gc. An equivalent hydrogen bond cannot be formed by LPyV VP1. © 2014, American Society for Microbiology.
Keywords: glycan; n glycoloylneuraminic acid; oligosaccharide; protein VP1; article; binding site; complex formation; controlled study; cross reaction; crystal structure; crystallography; hydrogen bond; microarray analysis; molecular cloning; nonhuman; nucleotide sequence; Polyoma virus; Polyomavirus 9 VP1; priority journal; protein expression; receptor binding; structure analysis; viral tropism; Capsid Proteins; Cloning, Molecular; Crystallography; Humans; Hydrogen Bonding; Microarray Analysis; Models, Molecular; Neuraminic Acids; Polyomavirus; Polysaccharides; Protein Conformation

A fucose containing polymer-rich fraction from the brown alga Ascophyllum nodosum mediates lifespan increase and thermal-tolerance in Caenorhabditis elegans, by differential effects on gene and protein expression - Kandasamy, S.; Khan, W.; Evans, F.D.; Critchley, A.T.; Zhang, J.; Fitton, J.H.; Stringer, D.N.; Gardiner, V.-A.; Prithiviraj, B. (Food and Function, 2014)
The extracts of the brown alga, Ascophyllum nodosum, which contains several bioactive compounds, have been shown to impart biotic and abiotic stress tolerance properties when consumed by animals. However, the physiological, biochemical and molecular mechanism underlying such effects remain elusive. We investigated the effect of A. nodosum fucose-containing polymer (FCP) on tolerance to thermally induced stress using the invertebrate animal model, Caenorhabditis elegans. FCP at a concentration of 150 μg mL-1 significantly improved the life span and tolerance against thermally induced stress in C. elegans. The treatment increased the C. elegans survival by approximately 24%, when the animals were under severe thermally induced stress (i.e. 35 °C) and 27% under mild stress (i.e. 30 °C) conditions. The FCP induced differential expression of genes and proteins is associated with stress response pathways. Under thermal stress, FCP treatment significantly altered the expression of 65 proteins (54 up-regulated & 11 down-regulated). Putative functional analysis of FCP-induced differential proteins signified an association of altered proteins in stress-related molecular and biochemical pathways of the model worm. © 2014 The Royal Society of Chemistry.
Keywords: Bioactive compounds; Biochemical pathway; Biotic and abiotic stress; Caenorhabditis elegans; Differential effect; Differential expressions; Invertebrate animals; Thermally induced stress; Animals; Gallium alloys; Proteins; Gene expression

Molecular susceptibility weighted imaging of the glioma rim in a mouse model - Blasiak, Barbara; Landry, James; Tyson, Randy; Sharp, Jonathan; Iqbal, Umar; Abulrob, Abedelnasser; Rushforth, David; Matyas, John; Ponjevic, Dragana; Sutherland, Garnette R.; Wolfsberger, Stefan; Tomanek, Boguslaw (Journal of Neuroscience Methods, 2014)
Background: Glioma is the most common and most difficult to treat brain cancer. Despite many efforts treatment, efficacy remains low. As neurosurgical removal is the standard procedure for glioma, a method, allowing for both early detection and exact determination of the location, size and extent of the tumor, could improve a patient's positive response to therapy. New method: We propose application of susceptibility weighted molecular magnetic resonance imaging using, targeted contrast agents, based on superparamagnetic iron oxide nanoparticles, for imaging of the, glioma rim, namely brain-tumor interface. Iron oxide attached to the targeted cells increases, susceptibility differences at the boundary between tumor and normal tissue, providing the opportunity, to utilize susceptibility weighted imaging for improved tumor delineation. We investigated potential, enhancement of the tumor-brain contrast, including tumor core and rim when using susceptibility, weighted MRI for molecular imaging of glioma. Results: There were significant differences in contrast-to-noise ratio before, 12 and 120. min after contrast, agent injection between standard gradient echo pulse sequence and susceptibility weighted molecular, magnetic resonance imaging for the core-brain, tumor rim-core and tumor rim-brain areas. Comparison with existing methods: Currently, the most common MRI contrast agent used for glioma diagnosis is a non-specific, gadolinium-based agent providing T1-weighted enhancement. Susceptibility-weighted magnetic, resonance imaging is much less efficient when no targeted superparamagnetic contrast agents are, used. Conclusion: The improved determination of glioma extent provided by SWI offers an important new tool for, diagnosis and surgical planning.

Simultaneous formation of nitrogen and sulfur-doped transition metal catalysts for oxygen reduction reaction through pyrolyzing carbon-supported copper phthalocyanine tetrasulfonic acid tetrasodium salt - Qing, X.; Shi, J.; Ma, C.; Fan, M.; Bai, Z.; Chen, Z.; Qiao, J.; Zhang, J. (Journal of Power Sources, 2014)
In this work, we report a spontaneous formation of copper (Cu-N-S/C) catalysts containing both nitrogen (N) and sulfur (S) elements using a one-step pyrolysis of carbon supported copper phthalocyanine tetrasulfonic acid tetrasodium salt (CuTSPc/C). The obtained catalysts exhibit high catalytic activities for oxygen reduction reaction (ORR) in alkaline media. Through electrochemical measurements and physical characterizations, several observations are reached as follows: (1) different pyrolysis temperatures can result in different catalyst structures and performances, and the optimum pyrolysis temperature is found to be 700 °C; (2) the electron transfer number of the ORR process catalyzed by the unpyrolyzed catalyst is about 2.5, after the pyrolysis, this number is increased to 3.5, indicating that the pyrolysis process can change the ORR pathway from a 2-electron transfer dominated process to a 4-electron transfer dominated one; (3) increasing catalyst loading from 40 μg cm-2 to 505 μg cm-2 can effectively improve the catalytic ORR activity, under which the percentage of H2O2 produced decreases sharply from 39.5% to 7.8%; and (4) the Cu ion can bond on pyridinic-N, graphite-N and C-Sn-C to form Cu-N-S/C catalyst active sites, which play the key role in the ORR activity. © 2014 Elsevier B.V. All rights reserved.
Keywords: Carbon; Electrolytic reduction; Electron transitions; Loading; Nitrogen; Sulfur; Transition metal compounds; Active site; Copper phthalocyanine; Copper phthalocyanine tetrasulfonic acid; Doped carbons; Electrochemical measurements; Oxygen reduction reaction; Physical characterization; Transition metal catalysts; Catalyst activity

Quantum strain sensor with a topological insulator HgTe quantum dot - Korkusinski, M.; Hawrylak, P. (Scientific Reports, 2014)
We present a theory of electronic properties of HgTe quantum dot and propose a strain sensor based on a strain-driven transition from a HgTe quantum dot with inverted bandstructure and robust topologically protected quantum edge states to a normal state without edge states in the energy gap. The presence or absence of edge states leads to large on/off ratio of conductivity across the quantum dot, tunable by adjusting the number of conduction channels in the source-drain voltage window. The electronic properties of a HgTe quantum dot as a function of size and applied strain are described using eight-band k·p Luttinger and Bir-Pikus Hamiltonians, with surface states identified with chirality of Luttinger spinors and obtained through extensive numerical diagonalization of the Hamiltonian.

Heat release rates of modern residential furnishings during combustion in a room calorimeter - Bwalya, A.; Gibbs, E.; Lougheed, G.; Kashef, A. (Fire and Materials, 2014)
Results are presented from a number of fire experiments that were conducted in a room environment to study the fire characteristics of typical residential furnishings and assist in the design of a subsequent phase of a project involving fully furnished room fire experiments. The experiments were conducted in a 16-m2 test room (with dimensions 3.8m wide×4.2m long×2.4m high), which had a 1.5×1.5-m window opening. The furnishings tested included mattresses, bed clothes, bed assemblies, upholstered seating furniture, clothing arrangements, books, plastic audio/video media and storage cases, toys, shoes, and a computer workstation setup. The smoke (gaseous products of combustion) from the room was collected using a hood system in order to measure the heat release rate (HRR) and optical density of the smoke. The test room was instrumented with load cells, heat flux gauges, thermocouples and velocity probes in order to take the following measurements: mass loss, total heat flux on gauge-installed flush with the internal surfaces (floor, walls, and ceiling), temperatures at numerous locations, and gas velocities in the window opening. Twin-size mattresses produced peak HRRs of approximately 3800kW, and the maximum room temperature was approximately 980°C. The HRRs of bed assemblies of various sizes and configurations ranged from 1800kW for a twin-size bed to 6250kW for a bunk bed. The maximum temperature and heat flux recorded in the experiments were 1071°C and 221kW/m2, respectively. Upholstered chairs and sofas had HRRs ranging from 630kW for an ottoman to 3360kW for a two-seat sofa. In tests with clothing, toys, shoes, books, a computer workstation, and CD/DVD media, the peak HRRs ranged from 440kW for a bookcase to 2045kW for toys. Furnishings containing a large proportion of rigid thermoplastic plastics, such as shoes and media cases, produced very dense smoke even at low HRRs. The effect of parameters such as bed clothes, mattress type, foundation type, bed assembly and chair size, material composition, and fuel package arrangement was evident in the results. Because the room dimensions and wall lining materials remained constant, temperatures were linearly proportional to the peak HRR (and exposure time) until the ventilation limit (approximately 4100kW) was reached. © 2014 John Wiley & Sons, Ltd.

Chromaticity-matched but spectrally different light source effects on simple and complex color judgments - Veitch, Jennifer A.; Whitehead, Lorne A.; Mossman, Michele; Pilditch, Toby D. (Color Research and Application, 2014)
As light-emitting diode (LED) light sources mature, lighting designers will be able to deliver white light with a variety of spectral power distributions and a variety of color rendering properties. This experiment examined the effects of three spectral power distributions (SPDs) that were matched in illuminance and chromaticity on three measures of color perception: one objective (performance on the Farnsworth-Munsell 100 hue test) and two subjective (judgments of the attractiveness of one's own skin, and preferences for the saturation of printed images). The three SPDs were a quartz-halogen (QH) lamp and two LED sources that were matched to the QH lamp in terms of both illuminance and chromaticity; the three light sources were nominally CCT = 3500 K, x = 0.40, y = 0.39 and ∼ 400 lx. LED A used three channels (red, green, blue), and had very poor color rendering (Ra = 18). LED B used four channels (red, amber, cyan, white) and had very good color rendering (R a = 96, whereas the QH had Ra = 98). Secondary hypotheses addressed the effects of age and skin and eye color on the dependent measures. As expected, LED A delivered very different color perceptions on all measures when compared to QH; LED B did not differ from QH. The results show that it is possible for LED sources to match the familiar incandescent sources. However, although it is possible to deliver what appear to be millions of colors with a three-chip (RGB) device, there is the risk of creating a very poor luminous environment. © 2013 National Research Council Canada and Wiley Periodicals, Inc.
Keywords: Color rendering properties; Different lights; illuminants; Printed images; Source effects; Spectral power distribution; Color image processing; Color vision; Light sources; Quartz; Light emitting diodes

N,N′-Bis(salicylidene)ethylenediamine as a nitrogen-rich precursor to synthesize electrocatalysts with high methanol-tolerance for polymer electrolyte membrane fuel cell oxygen reduction reaction - Zhou, X.; Xu, P.; Xu, L.; Bai, Z.; Chen, Z.; Qiao, J.; Zhang, J. (Journal of Power Sources, 2014)
A cost-effective chemical, N,N′-bis(salicylidene)ethylenediamine (salen), is used as a ligand to form a carbon-supported Co-salen complex (Co-salen/C) by a simple solid-sate reaction. The Co-salen/C is then pyrolyzed at 600, 700, 800, 900, and 1000 °C to form carbon-supported Co-N-S/C catalysts for the oxygen reduction reaction (ORR). XRD, EDX, TEM, and XPS are used to characterize the catalysts' composition, crystalline nature, morphology, and possible surface groups induced by heat-treatment. Investigation of the catalytic activity and the ORR mechanisms using rotating disk electrode and rotating ring-disk electrode techniques demonstrates that all of these Co-N-S/C catalysts are highly active for the ORR in an O2-saturated 0.1 M KOH solution, but the catalyst heat treated at 700°C gives the best ORR activity. The overall electron transfer number for the catalyzed ORR was determined to be 3.6-3.9, with 3.7-19.9% H2O2 production over the potential range of -0.05 to -0.60 V, suggesting that the ORR catalyzed by Co-N-S/C catalysts is dominated by a 4-electron transfer pathway from O 2 to H2O. In addition, these catalysts exhibit superior methanol tolerance to commercial 40% Pt/C catalyst, thus the Co-N-S/C catalysts are promising for use as electrocatalysts in alkaline polymer electrolyte membrane fuel cells. © 2014 Elsevier B.V. All rights reserved.
Keywords: Active site; Alkaline polymer electrolyte membrane; Methanol tolerance; Non-precious metal catalysts; Oxygen reduction reaction; Rotating disk electrodes; Rotating ring-disk electrode techniques; Solid-sate reactions; Alkaline fuel cells; Alkalinity; Carbon; Catalysis; Electrocatalysts; Electrolytes; Electrolytic reduction; Electron transitions; Methanol; Proton exchange membrane fuel cells (PEMFC); Rotating disks; Cobalt compounds

Radiative heat transfer through the fuel-rich core of laboratory-scale pool fires - Consalvi, J.L.; Liu, F. (Combustion Science and Technology, 2014)
Radiative heat transfer calculations are conducted along the axis of six axisymmetric pool fires by using the "exact" line-by-line (LBL) method, the narrow band correlated k (NBCK) model, the full-spectrum correlated k (FSCK) model, the multi-scale full-spectrum k-distribution (MSFSK) model, and the wide-band model implemented in the fire dynamic simulator (FDS). The two baseline cases correspond to 34 kW and 176 kW methane pool fires generated on a burner of 0.38 m diameter. For each heat release rate, two other moderately and heavily sooting pool fires were generated by considering higher soot volume fractions while keeping temperature and gaseous species concentrations unaltered. For each radiative model, the corresponding absorption coefficients for carbon dioxide, water vapor, carbon monoxide, and methane were generated from the same high-resolution spectroscopic databases. Model results show that the contribution of carbon monoxide to the radiative intensity can be neglected, whereas that of methane increases with the heat release rate (HRR) and decreases as the soot loading increases. It is also found that the gray approximation for soot holds for the 34 kW pool fires and the weakly and moderately sooting 176 kW pool fires but ceases to be valid for the heavily sooting 176 kW pool fire. Concerning the accuracy of the different approximate radiative models, comparisons with the LBL solutions show that the NBCK model can be used as a reference if LBL solutions are not available. On the other hand, the FDS wide-band model fails in predicting accurately the radiative intensity through the fuel-rich core of pool fires. Finally, the FSCK provide predictions within 10% of LBL solutions with the exception of the heavily sooting 176 kW pool fire where the strong attenuation of radiation by methane invalidates the "correlated" assumption of the absorption coefficient. In this case, the MSFSK model must be considered, improving substantially the predictions of the FSCK. Copyright © Taylor & Francis Group, LLC.
Keywords: Absorption spectroscopy; Carbon dioxide; Carbon monoxide; Forecasting; Fuels; Loading; Methane; Plasma diagnostics; Radiative transfer; Soot; Absorption co-efficient; Fire dynamic simulators; Fuel-rich core; Gaseous species concentrations; Heat Release Rate (HRR); Radiative heat transfer; Soot volume fraction; Spectroscopic database; Fire protection

Process window for friction stir lap welding of aluminum alloy 6061 - Larose, S.; Guérin, M.; Wanjara, P. (Advanced Materials Research, 2014)
Precipitation-hardenable 6xxx series aluminum alloys are incorporated in many structural components with due consideration of their good combination of properties including a relatively high strength, outstanding extrudability and excellent corrosion resistance. Accordingly, AA6061 has been identified as a very good candidate material for structural lightweighting of transportation vehicles. However, the weldability of aluminum alloy (AA) 6061 by means of conventional technologies such as GMAW and GTAW methods is limited by sensitivity to solidification cracking. In this respect, friction stir welding (FSW) presents a tremendous potential for assembly of aluminum structures for the transportation industry due to the low heat involved that can mitigate crack formation and, thus, translate into improved mechanical performance of the assembly. In this work, FSW of 3.18 mm thick AA6061-T6 sheets in the lap joint configuration was investigated. This configuration is considered to be more challenging for assembly by FSW than the butt joint type due to the orientation of the interface with respect to the welding tools and the necessity to break the oxide layer on two aluminium alloy planar surfaces. Weld trials were performed to examine the influence of the FSW tool geometry and process parameters on the welding defects, microstructure, hardness and bend performance. Unacceptable material expulsion and/or significant thinning in one of the two overlapped sheets were produced under most conditions. A set of FSW tool geometries leading to a viable process operational window under which the risk of defects could be mitigated and/or eliminated was identified in this study. © (2014) Trans Tech Publications, Switzerland.
Keywords: Aluminum alloys; Corrosion resistance; Cracks; Materials handling; Welding; AA6061-T6; Excellent corrosion resistances; Friction stir lap welding; Friction stir welding(FSW); Lap welding; Process window; Solidification cracking; Transportation vehicles; Friction stir welding

Transgenic expression of neuronal dystonin isoform 2 partially rescues the disease phenotype of the Dystonia musculorum mouse model of hereditary sensory autonomic neuropathy VI - Ferrier, A.; Sato, T.; De Repentigny, Y.; Gibeault, S.; Bhanot, K.; O'Meara, R.W.; Lynch-Godrei, A.; Kornfeld, S.F.; Young, K.G.; Kothary, R. (Human Molecular Genetics, 2014)
A newly identified lethal form of hereditary sensory and autonomic neuropathy (HSAN), designated HSAN-VI, is caused by a homozygous mutation in the bullous pemphigoid antigen 1 (BPAG1)/dystonin gene (DST). The HSAN-VI mutation impacts all major neuronal BPAG1/dystonin protein isoforms: dystonin-a1, -a2 and -a3. Homozygous mutations in the murine Dst gene cause a severe sensory neuropathy termed dystonia musculorum (dt). Phenotypically, dt mice are similar to HSAN-VI patients, manifesting progressive limb contractures, dystonia, dysautonomia and early postnatal death. To obtain a better molecular understanding of disease pathogenesis in HSAN-VI patients and the dt disorder, we generated transgenic mice expressing a myc-tagged dystonin-a2 protein under the regulation of the neuronal prion protein promoter on the dtTg4/Tg4 background, which is devoid of endogenous dystonin-a1 and -a2, but does express dystonin-a3. Restoring dystonin-a2 expression in the nervous system, particularly within sensory neurons, prevented the disorganization of organelle membranes and microtubule networks, attenuated the degeneration of sensory neuron subtypes and ameliorated the phenotype and increased life span in these mice. Despite these improvements, complete rescue was not observed likely because of inadequate expression of the transgene. Taken together, this study provides needed insight into the molecular basis of the dt disorder and other peripheral neuropathies including HSAN-VI. © The Author 2013. Published by Oxford University Press. All rights reserved.

Solvation models: Theory and validation - Purisima, E.O.; Sulea, T. (Current Pharmaceutical Design, 2014)
Water plays an active role in many fundamental phenomena in cellular systems such as molecular recognition, folding and conformational equilibria, reaction kinetics and phase partitioning. Hence, our ability to account for the energetics of these processes is highly dependent on the models we use for calculating solvation effects. For example, theoretical prediction of protein-ligand binding modes (i.e., docking) and binding affinities (i.e., scoring) requires an accurate description of the change in hydration that accompanies solute binding. In this review, we discuss the challenges of constructing solvation models that capture these effects, with an emphasis on continuum models and on more recent developments in the field. In our discussion of methods, relatively greater attention will be given to boundary element solutions to the Poisson equation and to nonpolar solvation models, two areas that have become increasingly important but are likely to be less familiar to many readers. The other focus will be upon the trending efforts for evaluating solvation models in order to uncover limitations, biases, and potentially attractive directions for their improvement and applicability. The prospective and retrospective performance of a variety of solvation models in the SAMPL blind challenges will be discussed in detail. After just a few years, these benchmarking exercises have already had a tangible effect in guiding the improvement of solvation models. © 2014 Bentham Science Publishers.

Silicon atomic quantum dots enable beyond-CMOS electronics - Wolkow, Robert A.; Livadaru, Lucian; Pitters, Jason; Taucer, Marco; Piva, Paul; Salomons, Mark; Cloutier, Martin; Martins, Bruno V. C. (Field-Coupled Nanocomputing : Paradigms, Progress, and Perspectives, 2014)
We review our recent efforts in building atom-scale quantum-dot cellular automata circuits on a silicon surface. Our building block consists of silicon dangling bond on a H-Si(001) surface, which has been shown to act as a quantum dot. First the fabrication, experimental imaging, and charging character of the dangling bond are discussed. We then show how precise assemblies of such dots can be created to form artificial molecules. Such complex structures can be used as systems with custom optical properties, circuit elements for quantum-dot cellular automata, and quantum computing. Considerations on macro-to-atom connections are discussed.
Keywords: Atoms; Dangling bonds; Quantum computers; Quantum optics; Semiconductor quantum dots; Silicon; Artificial molecule; Atomic quantum dots; Complex structure; Precise assembly; Quantum Computing; Quantum dot cellular automata; Silicon dangling bond; Silicon surfaces; Automata theory

Purification and characterization of hydrolytic and transgalactosyl α-galactosidase from Lactobacillus helveticus ATCC 10797 - Kandari, S.; Choi, Y.J.; Lee, B.H. (European Food Research and Technology, 2014)
α-Galactosidase purified from Lactobacillus helveticus ATCC 10797 by fast performance liquid chromatography system using ion exchange and gel-filtration columns showed the Km of 3.83 mM and Vmax of 416.44 μmol/min/mg protein calculated from the substrate p-nitrophenyl-α-d-galactopyranoside. The molecular mass was 188 kDa by gel-filtration, but 90 kDa by SDS-PAGE, indicating a homodimer. The optimum temperature was 37 °C, and the optimum pH was at 6 with an acceptable stability between pH 4 and 8. This enzyme was activated by 10 mM monovalent ions such as K+, NH4 +, Li+, and CS+, while the activity was inhibited by divalent ions such as Cu2+, Zn2+, and Fe2+. Melibiose was hydrolyzed to glucose and galactose, raffinose to galactose and sucrose, while stachyose to galactose and sucrose. A novel source of α-galactosidase from L. helveticus possessing both hydrolytic activity to eliminate flatulence sugars and transgalactosylation activities to synthesize galacto-oligosaccharides is identified and characterized. © 2014 Springer-Verlag Berlin Heidelberg.

Molecular insights on the recognition of a Lactococcus lactis cell wall pellicle by the phage 1358 receptor binding protein - Farenc, C.; Spinelli, S.; Vinogradov, E.; Tremblay, D.; Blangy, S.; Sadovskaya, I.; Moineau, S.; Cambillau, C. (Journal of Virology, 2014)
The Gram-positive bacterium Lactococcus lactis is used for the production of cheeses and other fermented dairy products. Accidental infection of L. lactis cells by virulent lactococcal tailed phages is one of the major risks of fermentation failures in industrial dairy factories. Lactococcal phage 1358 possesses a host range limited to a few L. lactis strains and strong genomic similarities to Listeria phages. We report here the X-ray structures of phage 1358 receptor binding protein (RBP) in complex with monosaccharides. Each monomer of its trimeric RBP is formed of two domains: a "shoulder" domain linking the RBP to the rest of the phage and a jelly roll fold "head/host recognition" domain. This domain harbors a saccharide binding crevice located in the middle of a monomer. Crystal structures identified two sites at the RBP surface,̃8 Å from each other, one accommodating a GlcNAc monosaccharide and the other accommodating a GlcNAc or a glucose 1-phosphate (Glc1P) monosaccharide. GlcNAc and GlcNAc1P are components of the polysaccharide pellicle that we identified at the cell surface of L. lactis SMQ-388, the host of phage 1358. We therefore modeled a galactofuranose (Galf) sugar bridging the two GlcNAc saccharides, suggesting that the trisaccharidic motif GlcNAc-Galf-GlcNAc (or Glc1P) might be common to receptors of genetically distinct lactococcal phages p2, TP091-1, and 1358. Strain specificity might therefore be elicited by steric clashes induced by the remaining components of the pellicle hexasaccharide. Taken together, these results provide a first insight into the molecular mechanism of host receptor recognition by lactococcal phages. © 2014, American Society for Microbiology.
Keywords: binding protein; glucose 1 phosphate; monomer; monosaccharide; phage 1358 receptor binding protein; unclassified drug; article; bacterial cell wall; bacterial cell wall pellicle; bacteriophage; binding site; cell surface; controlled study; crystal structure; Lactococcus lactis; nonhuman; phage 1358; phage TP091 1; priority journal; protein carbohydrate interaction; protein domain; protein motif; protein structure

Assessment of tissue oxygenation of periodontal inflammation in patients with coronary artery diseases using optical spectroscopy - Zhang, C.; Xiang, X.; Xu, M.; Fan, C.; Sowa, M.G.; Liu, K.-Z. (BMC Oral Health, 2014)
Background: We have recently developed a non-invasive periodontal diagnostic tool that was validated in periodontitis patients without systemic disorders like coronary artery disease (CAD). The purpose of present study is to verify whether this optical instrument can also be used in periodontitis patients with CAD.Methods: A total of 62 periodontitis patients with CAD were recruited along with a control group consisting of 59 age and gender matched periodontitis volunteers without systemic disorders. Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed and evaluated from the two groups. A modified Beer-Lambert unmixing model that incorporates a nonparametric scattering loss function was used to determine the relative contribution of deoxygenated hemoglobin (Hb) and oxygenated hemoglobin (HbO2) to the overall spectrum. The balance between tissue oxygen delivery and utilization in periodontal tissues was then assessed.Results: Tissue oxygen saturation was significantly decreased in the periodontitis sites (p < 0.01), compared to the healthy sites in those individuals with CAD. There was a trend towards increased concentration of Hb and decreased concentration of HbO2 from healthy to diseased sites, without statistical significance (p > 0.05). No statistical differences were found in tissue oxygen saturation between the CAD and control groups either in periodontal healthy or inflammatory sites.Conclusion: This study supports the hypothesis that optical spectroscopy can determine the periodontal inflammation in patients with certain systemic disorders like CAD. And the overall periodontal oxygenation profiles in CAD patients resemble those in non-CAD individuals either in healthy or inflammatory sites. © 2014 Zhang et al.; licensee BioMed Central Ltd.

In vivo imaging of brain cancer using epidermal growth factor single domain antibody bioconjugated to near-infrared quantum dots - Fatehi, D.; Baral, T.N.; Abulrob, A. (Journal of Nanoscience and Nanotechnology, 2014)
Diagnosis of glioblastoma multiform (GBM) with MRI lacks molecular information and requires a biopsy for pathologic confirmation. The EGFRvIII, is a constitutively active mutant of the EGF receptor, identified in a high percentage of brain cancers and associated with increased invasiveness and resistance, making it a good target to improve imaging and diagnosis. The present study shows that conjugation of near-infrared quantum dot (Qd800) to an anti-EGFRvIII single domain antibody, made of the variable region with an extra cysteine for site-specific conjugation (EG2-Cys), increased its internalization in U87MG-EGFRvIII cells in vitro compared to Qd800 conjugated with the Fc region of the antibody (EG2-hFc) or unconjugated. EG2-Cys also improved the contrast in Near-Infrared Imaging of mice bearing orthotopic glioblastoma. The increased accumulation was confirmed by fluorescence microscopy of brain sections. The specificity of EG2-Cys in brain tumor expressing the EGFRvIII mutant receptor may provide an accurate less invasive diagnosis and determine the level of tumor aggressiveness and resistance. Copyright © 2014 American Scientific Publishers All rights reserved.
Keywords: EGFR protein, mouse; epidermal growth factor receptor; monoclonal antibody; quantum dot; animal; article; brain tumor; fluorescence microscopy; glioblastoma; human; infrared radiation; metabolism; methodology; molecular imaging; mouse; nude mouse; pathology; reproducibility; sensitivity and specificity; tumor cell line; Animals; Antibodies, Monoclonal; Brain Neoplasms; Cell Line, Tumor; Glioblastoma; Humans; Infrared Rays; Mice; Mice, Nude; Microscopy, Fluorescence; Molecular Imaging; Quantum Dots; Receptor, Epidermal Growth Factor; Reproducibility of Results; Sensitivity and Specificity

The disk around the brown dwarf KPNO TAU 3 - Broekhoven-Fiene, H.; Matthews, B.; Duchêne, G.; Di Francesco, J.; Scholz, A.; Chrysostomou, A.; Jayawardhana, R. (The Astrophysical Journal, 2014)
We present submillimeter observations of the young brown dwarfs KPNO Tau 1, KPNO Tau 3, and KPNO Tau 6 at 450 μm and 850 μm taken with the Submillimetre Common-User Bolometer Array on the James Clerk Maxwell Telescope. KPNO Tau 3 and KPNO Tau 6 have been previously identified as Class II objects hosting accretion disks, whereas KPNO Tau 1 has been identified as a Class III object and shows no evidence of circumsubstellar material. Our 3σ detection of cold dust around KPNO Tau 3 implies a total disk mass of (4.0 ± 1.1) × 10-4 M ⊙ (assuming a gas to dust ratio of 100:1). We place tight constraints on any disks around KPNO Tau 1 or KPNO Tau 6 of <2.1 × 10-4 M ⊙ and <2.7 × 10-4 M ⊙, respectively. Modeling the spectral energy distribution of KPNO Tau 3 and its disk suggests the disk properties (geometry, dust mass, and grain size distribution) are consistent with observations of other brown dwarf disks and low-mass T-Tauri stars. In particular, the disk-to-host mass ratio for KPNO Tau 3 is congruent with the scenario that at least some brown dwarfs form via the same mechanism as low-mass stars. © 2014. The American Astronomical Society. All rights reserved..

Intrasasal vaccination against acinetobacter baumannii-associated pneumonia in mice - Kuo Lee, Rhonda; Harris, Gregg; Yan, Hongbin; Xu, H. Howard; Conlan, Wayne J.; Patel, Girishchandra B.; Chen, Wangxue (Vaccine, 2014)
Multidrug-resistant Acinetobacter baumannii has become an important causative agent of healthcare associated infections. Hospital- and community-acquired pneumonia is the most common clinical manifestation of A. baumannii infection worldwide and is often associated with high mortality. Most experimental vaccine studies to date have evaluated vaccines against systemic A. baumannii infections following systemic immunization. We recently demonstrated that a mouse model of respiratory A. baumannii infection using the strain LAC-4 results in disease progression that is similar to that observed in humans. Here we used this model in conjunction with an inactivated whole cell vaccine to evaluate the feasibility of developing protective mucosal vaccines against respiratory A. baumannii infection and to investigate the potential mechanism of protection of such vaccines. Our results showed that intranasal immunization with formalin-killed whole cells of the LAC-4 strain elicited mucosal and systemic antigen-specific immune responses, and protected mice against lethal intranasal or intraperitoneal challenges. Compared to naïve mice, immunized mice had significantly fewer bacteria in their lungs, and the pathogen was barely detectable in blood and spleens at 24 h post challenge, indicating the ability of immunized mice to control extrapulmonary dissemination of the pathogen. Mechanistic studies using gene-deficient mice, neutropenic mice, or passive immunization showed that B cells and neutrophils, but not FcRγ, played crucial roles in the protection against respiratory A. baumannii challenge of intranasally immunized mice whereas passive transfer of hyperimmune sera only prolonged the survival time of challenged mice by 48 h. These results provide immunological insights for the rational design of novel mucosal vaccines to protect against respiratory A. baumannii infection and demonstrate the feasibility to develop such vaccines.
Keywords: Acinetobacter baumannii; Pneumonia; Mucosal immunization; B cells; Neutrophils

Stimulation of insulin signaling and inhibition of JNK-AP1 activation protect cells from amyloid-β-induced signaling dysregulation and inflammatory response - Bamji-Mirza, M.; Callaghan, D.; Najem, D.; Shen, S.; Hasim, M.S.; Yang, Z.; Zhang, W. (Journal of Alzheimer's Disease, 2014)
One of the hallmarks of Alzheimer's disease (AD) is the accumulation and deposition of amyloid-β (Aβ) peptides in the brain and cerebral vasculature. Aβ evokes neuroinflammation and has been implicated in insulin signaling disruption and JNK-AP1 activation, contributing to AD neuropathologies including oxidative injury and vascular insufficiencies. In this study we aim to better understand the protective mechanisms of insulin signaling and JNK-AP1 inhibition on the adverse effects of Aβ. Four-hour treatment of hCMEC/D3, the immortalized human brain endothelial cells (iHBEC), with Aβ1-42 resulted in significant c-Jun phosphorylation, oxidative stress, and cell toxicity. Concurrent treatment with Aβ1-42 and insulin or Aβ1-42 and JNK inhibitor SP600125 significantly improved cell viability. Cytokine array on conditioned media showed that insulin and SP600125 strongly reduced all Aβ 1-42-induced cytokines. ELISA confirmed the protective effect of insulin and SP600125 on Aβ-induced expression of interleukin (IL)-8 and Growth related oncogene-α (Gro-α). qRT-PCR revealed that insulin and SP600125 protected iHBEC from Aβ1-42-induced inflammatory gene expression. Transcription factor profiling showed that treatment of iHBEC with Aβ1-42, insulin, or SP600125 alone or in combination resulted in profound changes in modulating the activities of multiple transcription factors and relevant pathways, some of which were validated by western blot. Insulin treatment and JNK inhibition in vitro synergistically reduced c-Jun phosphorylation and thus JNK-AP1 signaling activation. The study suggests that activation of insulin and blocking of JNK-AP1 signaling inhibits Aβ-induced dysregulation of insulin signaling and inflammatory response.
Keywords: actin; amyloid beta protein; amyloid beta protein[1-42]; anthra[1,9 cd]pyrazol 6(2h) one; early growth response factor 2; granulocyte macrophage colony stimulating factor; insulin; interleukin 2; interleukin 23; interleukin 23p19; interleukin 32; interleukin 6; interleukin 8; macrophage inflammatory protein 1beta; monocyte chemotactic protein 1; protein c jun; stress activated protein kinase; transcription factor AP 1; transcription factor E2F1; tumor necrosis factor alpha; tumor suppressor protein; article; cell growth; cell viability; controlled study; cytokine release; cytotoxicity; densitometry; gene expression; human; human cell; immunoblotting; in vitro study; inflammation; insulin treatment; lipid oxidation; negative feedback; oxidative stress; priority journal; protein expression; protein phosphorylation; signal transduction; transcription initiation; Western blotting

Predicting the relative solubilities of racemic and enantiopure crystals by density-functional theory - Otero-de-la-Roza, A.; Cao, B.H.; Price, I.K.; Hein, J.E.; Johnson, E.R. (Angewandte Chemie - International Edition, 2014)
Isolation of chiral molecules as pure enantiomers remains a fundamental challenge in chemical research. Enantioselective enrichment through preferential crystallization is an efficient method to achieve enantiopure compounds, but its applicability depends on the relative stability of the enantiopure and racemic crystal forms. Using a simple thermodynamic model and first-principles density-functional calculations, it is possible to predict the difference in solubility between the enantiopure and racemic solid phases. This approach uses dispersion-corrected density functionals and is capable of accurately predicting the solution-phase entantiomeric excess to within about 10% of experimental measurements on average. The accuracy of the exchange-hole dipole moment (XDM) model of dispersion enables the viability of the proposed method. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Four-probe measurements with a three-probe scanning tunneling microscope - Salomons, M.; Martins, B.V.C.; Zikovsky, J.; Wolkow, R.A. (Review of Scientific Instruments, 2014)
We present an ultrahigh vacuum (UHV) three-probe scanning tunneling microscope in which each probe is capable of atomic resolution. A UHV JEOL scanning electron microscope aids in the placement of the probes on the sample. The machine also has a field ion microscope to clean, atomically image, and shape the probe tips. The machine uses bare conductive samples and tips with a homebuilt set of pliers for heating and loading. Automated feedback controlled tip-surface contacts allow for electrical stability and reproducibility while also greatly reducing tip and surface damage due to contact formation. The ability to register inter-tip position by imaging of a single surface feature by multiple tips is demonstrated. Four-probe material characterization is achieved by deploying two tips as fixed current probes and the third tip as a movable voltage probe. © 2014 AIP Publishing LLC.
Keywords: Loading; Microscopes; Scanning electron microscopy; Surfaces; Atomic resolution; Automated feedback; Contact formation; Electrical stability; Field ion microscope; Four-probe measurement; Material characterizations; Reproducibilities; Probes

Canadian Adjuvant Initiative Workshop, March 26-27, 2013-Ottawa, Canada - Krishnan, L.; Twine, S.; Gerdts, V.; Barreto, L.; Richards, J.C. (Human Vaccines and Immunotherapeutics, 2014)
Novel adjuvants hold the promise for developing effective modern subunit vaccines capable of appropriately modulating the immune response against challenging diseases such as those caused by chronic and/or intracellular pathogens and cancer. Over the past decade there has been intensive research into discovering new adjuvants, however, their translation into routine clinical use is lagging. To stimulate discussion and identify opportunities for networking and collaboration among various stakeholders, a Canadian Adjuvant Initiative Workshop was held in Ottawa. Sponsored by the National Research Council Canada, Canadian Institutes of Health Research and the Vaccine Industry Committee, a two day workshop was held that brought together key Canadian and international stakeholders in adjuvant research from industry, academia and government. To discover innovation gaps and unmet needs, the presentations covered a board range of topics in adjuvant development; criteria for selection of lead adjuvant candidates from an industry perspective, discovery research across Canada, bioprocessing needs and challenges, veterinary vaccines, Canadian vaccine trial capabilities, the Canadian regulatory framework and WHO formulation laboratory experience. The workshop concluded with a discussion on the opportunity to create a Canadian Adjuvant Development Network. This report details the key discussion points and steps forward identified for facilitating adjuvant development research in Canada. © 2014 Landes Bioscience.
Keywords: Wart virus vaccine; bioprocess; Canada; CD8+ T lymphocyte; commercial phenomena; conference paper; drug approval; drug formulation; drug industry; drug legislation; experimental model; health care delivery; health care policy; human; immune response; immunogenicity; nonhuman; trend study; vaccination; vaccine production; veterinary medicine

Quantitative nonlinear optical assessment of atherosclerosis progression in rabbits - Mostaço-Guidolin, L.B.; Kohlenberg, E.K.; Smith, M.; Hewko, M.; Major, A.; Sowa, M.G.; Ko, A.C.-T. (Analytical Chemistry, 2014)
Quantification of atherosclerosis has been a challenging task owing to its complex pathology. In this study, we validated a quantitative approach for assessing atherosclerosis progression in a rabbit model using a numerical matrix, optical index for plaque burden, derived directly from the nonlinear optical microscopic images captured on the atherosclerosis-affected blood vessel. A positive correlation between this optical index and the severity of atherosclerotic lesions, represented by the age of the rabbits, was established based on data collected from 21 myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits with age ranging between new-born and 27 months old. The same optical index also accurately identified high-risk locations for atherosclerotic plaque formation along the entire aorta, which was validated by immunohistochemical fluorescence imaging. © 2014 American Chemical Society.
Keywords: Blood vessels; Optical correlation; Atherosclerotic lesions; Atherosclerotic plaque; Fluorescence imaging; Microscopic image; Non-linear optical; Numerical matrices; Positive correlations; Quantitative approach; Diseases

Performance of laser polishing in finishing of metallic surfaces - Bordatchev, E.V.; Hafiz, A.M.K.; Tutunea-Fatan, O.R. (International Journal of Advanced Manufacturing Technology, 2014)
Laser polishing is presently regarded as one of the enabling technologies hoped to eventually replace the need for time-consuming and error-prone manual polishing operations which are often required by metallic surfaces. During laser polishing, a thin layer of material is being melted as a result of laser irradiation. Since molten metal is characterized by increased relocation capabilities, laser polishing is generally accompanied by a more or less significant decrease in the surface roughness. The primary objective of this study is to present a comprehensive snapshot of the advancements made over more than one decade with respect to theoretical and experimental investigation of laser polishing technology. However, in addition to the usual review of the state-of-theart in the field, the study places an increased emphasis on the finishing performance of the process, defined through the perspective of pre- and postpolishing surface roughness. The implementation of this metric with strong practical implications has revealed that under appropriate process parameters, certain classes of metallic materials can reduce their average surface roughness by more than 80 %, possibly to Ra=5 nm. Nonetheless, a more rigorous and fundamental understanding of the intrinsic mechanisms underlying laser polishing remains one of the currently unfulfilled premises toward a wider industrial adoption of the process. © Springer-Verlag London 2014.
Keywords: Liquid metals; Metallic compounds; Surface roughness; Laser polishing; Metallic material; Polishability; Process parameters; Surface finishes; Surface measurement

Derivation and experimental validation of Lamb wave equations for an n-layered anisotropic composite laminate - Pant, S.; Laliberte, J.; Martinez, M.; Rocha, B. (Composite Structures, 2014)
Lamb waves are ultrasonic guided waves that propagate between two parallel free surfaces and their use for damage detection has been widely explored and demonstrated. Damage in materials/structures can be detected by analyzing the difference between the phase/group velocity and the loss of amplitude of Lamb waves on damaged and un-damaged specimens. The propagation characteristics of Lamb waves are described in the form of dispersion curves, which are plots of phase/group velocities versus the product of frequency-thickness generated by solving the Lamb wave equations. Lamb waves' dispersion behaviors for isotropic materials are well established in the literature; however, such is not the case for the laminated composites. The most common methods for solving the Lamb wave equations in composites consist of using laminated plate theory or 3D linear elasticity by assuming an orthotropic and/or higher symmetry. This assumption may not be true, if the actuators and sensors in an orthotropic or transversely isotropic laminates are installed in a non-principle direction or the layup is symmetric but not balanced. This paper presents a full derivation of Lamb wave equations for n-layered monoclinic composite laminates based on linear 3D elasticity by considering the displacement fields in all three directions using the partial wave technique in combination with the Global Matrix (GM) approach. In the partial wave technique, the principle of superposition of three upward and three downward travelling plane waves are assumed in order to satisfy the associated boundary conditions. The bounded upper and lower surfaces reflect the waves and the combination of these reflections going towards the upper or lower interfaces results in the propagating guided waves. The GM approach is used to assemble all the equations from each layer to form a global, unified matrix that describes the displacement and stress fields along the entire laminate associated with the wave propagation. A robust method for numerically solving the Lamb wave equations is also presented. The presented method was verified experimentally by analyzing the propagation of Lamb waves in two different composite panels constructed out of unidirectional carbon-fiber epoxy prepreg and fiber-metal laminate (GLARE 3-3/4). The panels were instrumented with lead zirconate titanate (PZT) piezoelectric sensors, which were excited at different frequencies ranging from 20. kHz to 500. kHz to generate and acquire the waves. The waves were excited and gathered at three different propagation angles of 0°, 45°, and 90° for the carbon-fiber epoxy laminate panel and at six different angles of 0°, 20°, 45°, 70° and 90° for the fiber-metal laminates (GLARE). The phase and group velocities of the fundamental symmetric ( So) and anti-symmetric ( Ao) Lamb waves were extracted by tracking the peaks of each individual wave phase and the wave envelope respectively using an in-house code developed in MATLAB. It was found that the presented 3D linear elasticity model followed the experimental data closely for both symmetric and anti-symmetric Lamb modes. The analytical method presented in this paper was able to predict the Lamb wave dispersion for both the carbon-fiber epoxy laminate and the hybrid fiber-metal laminate proving the robustness and versatility of the solution method. © 2014 Elsevier Ltd.
Keywords: Carbon; Composite materials; Crystallography; Damage detection; Dispersion (waves); Dispersions; Elasticity; Fibers; Glare; Guided electromagnetic wave propagation; Matrix algebra; Semiconducting lead compounds; Surface waves; Three dimensional; Ultrasonic applications; Ultrasonic waves; Wave equations; Wave propagation; Acoustic-ultrasonic; Dispersion curves; Displacement and stress fields; Experimental validations; Fiber metal laminates; Phase and group velocities; Principle of superposition; Propagation characteristics; Laminated composites

High removal rate grinding of titanium alloys with electroplated CBN wheels - Shi, Z.; Attia, H. (International Journal of Abrasive Technology, 2014)
This paper is concerned with an experimental study on the grinding of a titanium alloy using electroplated CBN wheels with water-based grinding fluid and wheel surface cleaning fluid applied at high pressures. The objective is to explore the approaches and conditions to grind titanium alloys with enhanced material removal rates. Straight surface grinding experiments were conducted on titanium alloy blocks in both shallow depth of cut and creep-feed modes. Grinding power, forces, surface roughness, and radial wheel wear were measured. Specific material removal rates of 8 mm2/s in shallow cut mode and 3 mm2/s at a depth of cut as high as 3 mm in creep-feed mode were achieved without burning and smearing of ground surfaces. An average G-ratio of about 155 was obtained with a shallow depth of cut grinding condition. It was showed that it is feasible to grind titanium alloys with electroplated CBN wheels at enhanced removal rates by applying grinding and wheel cleaning fluid at high pressures. Copyright © 2014 Inderscience Enterprises Ltd.
Keywords: Creep; Surface roughness; Titanium alloys; Wheels; G ratio; Grinding conditions; Grinding power; High removal rates; Material removal rate; Removal rate; Specific materials; Wheel wears; Grinding (machining)

The gluconeogenesis pathway is involved in maintenance of enterohaemorrhagic Escherichia coli O157:H7 in bovine intestinal content - Bertin, Y.; Deval, C.; De La Foye, A.; Masson, L.; Gannon, V.; Harel, J.; Martin, C.; Desvaux, M.; Forano, E. (PLoS ONE, 2014)
Enterohaemorrhagic Escherichia coli (EHEC) are responsible for outbreaks of food- and water-borne illness. The bovine gastrointestinal tract (GIT) is thought to be the principle reservoir of EHEC. Knowledge of the nutrients essential for EHEC growth and survival in the bovine intestine may help in developing strategies to limit their shedding in bovine faeces thus reducing the risk of human illnesses. To identify specific metabolic pathways induced in the animal GIT, the transcriptome profiles of EHEC O157:H7 EDL933 during incubation in bovine small intestine contents (BSIC) and minimal medium supplemented with glucose were compared. The transcriptome analysis revealed that genes responsible for the assimilation of ethanolamine, urea, agmatine and amino acids (Asp, Thr, Gly, Ser and Trp) were strongly up-regulated suggesting that these compounds are the main nitrogen sources for EHEC in BSIC. A central role for the gluconeogenesis pathway and assimilation of gluconeogenic substrates was also pinpointed in EHEC incubated in BSIC. Our results suggested that three amino acids (Asp, Ser and Trp), glycerol, glycerol 3-phosphate, L-lactate and C4-dicarboxylates are important carbon sources for EHEC in BSIC. The ability to use gluconeogenic substrates as nitrogen sources (amino acids) and/or carbon sources (amino acids, glycerol and lactate) may provide a growth advantage to the bacteria in intestinal fluids. Accordingly, aspartate (2.4 mM), serine (1.9 mM), glycerol (5.8 mM) and lactate (3.6 mM) were present in BSIC and may represent the main gluconeogenic substrates potentially used by EHEC. A double mutant of E. coli EDL933 defective for phosphoenolpyruvate synthase (PpsA) and phosphoenolpyruvate carboxykinase (PckA), unable to utilize tricarboxylic acid (TCA) intermediates was constructed. Growth competition experiments between EHEC EDL933 and the isogenic mutant strain in BSIC clearly showed a significant competitive growth advantage of the wild-type strain further illustrating the importance of the gluconeogenesis pathway in maintaining EHEC in the bovine GIT. © 2014 Bertin et al.
Keywords: agmatine; amino acid; asparagine; aspartic acid; complementary DNA; dicarboxylic acid; ethanolamine; glycerol; glycerophosphate; glycine; lactic acid; nitrogen; phosphoenolpyruvate; phosphoenolpyruvate carboxykinase (GTP); pyruvate water dikinase; serine; threonine; transcriptome; tricarboxylic acid; tryptophan; unclassified drug; urea; article; bacterial strain; carbon source; cattle; DNA microarray; enterohemorrhagic Escherichia coli; gastrointestinal tract; gene expression; gluconeogenesis; nonhuman; nucleotide sequence; RNA extraction; small intestine; upregulation; wild type

Human mesenchymal stem cells express a myofibroblastic phenotype in vitro: comparison to human cardiac myofibroblasts - Ngo, M.A.; Müller, A.; Li, Y.; Neumann, S.; Tian, G.; Dixon, I.M.C.; Arora, R.C.; Freed, D.H. (Molecular and Cellular Biochemistry, 2014)
Cardiac fibrosis accompanies a variety of myocardial disorders, and is induced by myofibroblasts. These cells may be composed of a heterogeneous population of parent cells, including interstitial fibroblasts and circulating progenitor cells. Direct comparison of human bone marrow-derived mesenchymal stem cells (BM-MSCs) and cardiac myofibroblasts (CMyfbs) has not been previously reported. We hypothesized that BM-MSCs readily adopt a myofibroblastic phenotype in culture. Human primary BM-MSCs and human CMyfbs were isolated from patients undergoing open heart surgery and expanded under standard culture conditions. We assessed and compared their phenotypic and functional characteristics by examining their gene expression profile, their ability to contract collagen gels and synthesize collagen type I. In addition, we examined the role of non-muscle myosin II (NMMII) in modulating MSC myogenic function using NMMII siRNA knockdown and blebbistatin, a specific small molecule inhibitor of NMMII. We report that, while human BM-MSCs retain pluripotency, they adopt a myofibroblastic phenotype in culture and stain positive for the myofibroblast markers α-SMA, vimentin, NMMIIB, ED-A fibronectin, and collagen type 1 at each passage. In addition, they contract collagen gels in response to TGF-β1 and synthesize collagen similar to human CMyfbs. Moreover, inhibition of NMMII activity with blebbistatin completely attenuates gel contractility without affecting cell viability. Thus, human BM-MSCs share and exhibit similar physiological and functional characteristics as human CMyfbs in vitro, and their propensity to adopt a myofibroblast phenotype in culture may contribute to cardiac fibrosis. © 2014 Springer Science+Business Media New York.

Estimating the contribution of impurities to the uncertainty of metal fixed-point temperatures - Hill, K.D. (International Journal of Thermophysics, 2014)
The estimation of the uncertainty component attributable to impurities remains a central and important topic of fixed-point research. Various methods are available for this estimation, depending on the extent of the available information. The sum of individual estimates method has considerable appeal where there is adequate knowledge of the sensitivity coefficients for each of the impurity elements and sufficiently low uncertainty regarding their concentrations. The overall maximum estimate (OME) forsakes the behavior of the individual elements by assuming that the cryoscopic constant adequately represents (or is an upper bound for) the sensitivity coefficients of the individual impurities. Validation of these methods using melting and/or freezing curves is recommended to provide confidence. Recent investigations of indium, tin, and zinc fixed points are reported. Glow discharge mass spectrometry was used to determine the impurity concentrations of the metals used to fill the cells. Melting curves were analyzed to derive an experimental overall impurity concentration (assuming that all impurities have a sensitivity coefficient equivalent to that of the cryoscopic constant). The two values (chemical and experimental) for the overall impurity concentrations were then compared. Based on the data obtained, the pragmatic approach of choosing the larger of the chemical and experimentally derived quantities as the best estimate of the influence of impurities on the temperature of the freezing point is suggested rather than relying solely on the chemical analysis and the OME method to derive the uncertainty component attributable to impurities. © 2014 Her Majesty the Queen in Right of Canada.

The spiral arms of the milky way: The relative location of each different arm tracer within a typical spiral arm width - Vallée, J.P. (Astronomical Journal, 2014)
From the Sun's location in the Galactic disk, different arm tracers (CO, H I, hot dust, etc.) have been employed to locate a tangent to each spiral arm. Using all various and different observed spiral arm tracers (as published elsewhere), we embark on a new goal, namely the statistical analysis of these published data (data mining) to statistically compute the mean location of each spiral arm tracer. We show for a typical arm cross-cut, a separation of 400 pc between the mid-arm and the dust lane (at the inner edge of the arm, toward the Galactic center). Are some arms major and others minor? Separating arms into two sets, as suggested by some, we find the same arm widths between the two sets. Our interpretation is that we live in a multiple (four-arm) spiral (logarithmic) pattern (around a pitch angle of 12°) for the stars and gas in the Milky Way, with a sizable interarm separation (around 3 kpc) at the Sun's location and the same arm width for each arm (near 400 pc from mid-arm to dust lane). © 2014. The American Astronomical Society. All rights reserved.

Hybrid device employing three-dimensional arrays of MnO in carbon nanosheets bridges battery-supercapacitor divide - Wang, H.; Xu, Z.; Li, Z.; Cui, K.; Ding, J.; Kohandehghan, A.; Tan, X.; Zahiri, B.; Olsen, B.C.; Holt, C.M.B.; Mitlin, D. (Nano Letters, 2014)
It is a challenge to meld the energy of secondary batteries with the power of supercapacitors. Herein, we created electrodes finely tuned for this purpose, consisting of a monolayer of MnO nanocrystallites mechanically anchored by pore-surface terminations of 3D arrays of graphene-like carbon nanosheets ("3D-MnO/CNS"). The biomass-derived carbon nanosheets should offer a synthesis cost advantage over comparably performing designer nanocarbons, such as graphene or carbon nanotubes. High Li storage capacity is achieved by bulk conversion and intercalation reactions, while high rates are maintained through stable ∼20 nm scale diffusion distances. For example, 1332 mAh g -1 is reached at 0.1 A g-1, 567 mAh g-1 at 5 A g-1, and 285 mAh g-1 at 20 A g-1 with negligible degradation at 500 cycles. We employed 3D-MnO/CNS (anode) and carbon nanosheets (cathode) to create a hybrid capacitor displaying among the most promising performances reported: based on the active materials, it delivers 184 Wh kg-1 at 83 W kg-1 and 90 Wh kg-1 at 15-000 W kg-1 with 76% capacity retention after 5000 cycles. © 2014 American Chemical Society.
Keywords: Anodes; Energy storage; Graphene; Lithium; Manganese oxide; Nanosheets; Secondary batteries; Three dimensional; 3D arrays; Capacity retention; Carbon nanosheets; Diffusion distance; Hybrid devices; Intercalation reaction; Li-ion capacitors; MnO; Capacitors

Phase-pure crystalline zinc phosphide nanoparticles: Synthetic approaches and characterization - Mobarok, M.H.; Luber, E.J.; Bernard, G.M.; Peng, L.; Wasylishen, R.E.; Buriak, J.M. (Chemistry of Materials, 2014)
Zinc phosphide may have potential for photovoltaic applications due to its high absorptivity of visible light and the earth abundance of its constituent elements. Two different solution-phase synthetic strategies for phase-pure and crystalline Zn3P2 nanoparticles (∼3-15 nm) are described here using dimethylzinc and vary with phosphorus source. Use of tri-n-octylphosphine (TOP) with ZnMe2 takes place at high temperatures (∼350 C) and appears to proceed via rapid in situ reduction to Zn(0), followed by subsequent reaction with TOP over a period of several hours to produce Zn3P2 nanoparticles. Some degree of control over size was obtained through variance of the TOP concentration in solution; the average size of the particles decreases with increasing TOP concentration. With the more reactive phosphine, P(SiMe3)3, lower temperatures, ∼150 C, and shorter reaction times (1 h) are required. When P(SiMe3)3 is used, the reaction mechanism most likely proceeds via phosphido-bridged dimeric Zn(II) intermediates, and not metallic zinc species, as is the case with TOP. In all cases, the nanoparticles were characterized by a combination of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and solution and solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) analyses. Surface investigation through a combination of MAS 31P NMR and XPS analyses suggests that the particles synthesized with TOP at 350 C possess a core-shell structure consisting of a crystalline Zn3P 2 core and an amorphous P(0)-rich shell. Conversely, the ligand and phosphorus sources are decoupled in the P(SiMe3)3 synthesis, resulting in significantly reduced P(0) formation. © 2014 American Chemical Society.
Keywords: Constituent elements; Core shell structure; Nuclear magnetic resonance(NMR); Photovoltaic applications; Reaction mechanism; Synthetic approach; Synthetic strategies; Tri-n-octylphosphine; Chelation; Crystalline materials; Magic angle spinning; Nanoparticles; Phosphorus; Phosphorus compounds; Photoelectrons; Reaction intermediates; Synthesis (chemical); Transmission electron microscopy; X ray diffraction; X ray photoelectron spectroscopy; Zinc compounds; Zinc

Structural analysis of lipopolysaccharide produced by Heddleston serovars 10, 11, 12 and 15 and the identification of a new Pasteurella multocida lipopolysaccharide outer core biosynthesis locus, L6 - Harper, M.; St. Michael, F.; John, M.; Steen, J.; Van Dorsten, L.; Parnas, H.; Vinogradov, E.; Adler, B.; Cox, A.D.; Boyce, J.D. (Glycobiology, 2014)
Pasteurella multocida is a Gram-negative bacterial pathogen classified into 16 serovars based on lipopolysaccharide (LPS) antigens. Previously, we have characterized the LPS outer core biosynthesis loci L1, L2, L3, L5 and L7, and have elucidated the full range of LPS structures associated with each. In this study, we have determined the LPS structures produced by the type strains representing the serovars 10, 11, 12 and 15 and characterized a new LPS outer core biosynthesis locus, L6, common to all. The L6 outer core biosynthesis locus shares significant synteny with the L3 locus but due to nucleotide divergence, gene duplication and gene redundancy, the L6 and L3 LPS outer cores are structurally distinct. Using LPS structural and genetic differences identified in each L6 strain, we have predicted a role for most of the L6 glycosyltransferases in LPS assembly. Importantly, we have identified two glycosyltransferases, GctD and GatB, that differ by one amino acid, A162T, but use different donor sugars [uridine diphosphate (UDP)-Glc and UDP-Gal, respectively]. The longest outer core oligosaccharide, produced by the serovar 12 type strain, contained a terminal region consisting of β-Gal-(1,4)- β-GlcNAc-(1,3)-β-Gal-(1,4)-β-Glc that was identical in structure to the vertebrate glycosphingolipid, paragloboside. Mimicry of host glycosphingolipids has been observed previously in P. multocida strains belonging to L3 LPS genotype, which produce LPS similar in structure to the globo-series of glycosphingolipids. The expression of a paragloboside-like oligosaccharide on the LPS produced by the serovar 12 type strain indicates that strains belonging to the L6 LPS genotype may also engage in molecular mimicry. © The Author 2014.
Keywords: bacterium lipopolysaccharide; glycosyltransferase; n acetylglucosamine; oligosaccharide; uridine diphosphate galactose; uridine diphosphate glucose; article; bacterial genetics; biosynthesis; capillary electrophoresis; carbohydrate analysis; electrospray mass spectrometry; gene duplication; gene mutation; genetic difference; genotype; heteronuclear single quantum coherence; methylation; nonhuman; nuclear Overhauser effect; Pasteurella multocida; priority journal; serotype; synteny

Synthesis and optical properties of thiol functionalized CdSe/ZnS (Core/Shell) quantum dots by ligand exchange - Zhu, H.; Hu, M.Z.; Shao, L.; Yu, K.; Dabestani, R.; Zaman, M.B.; Liao, S. (Journal of Nanomaterials, 2014)
The colloidal photoluminescent quantum dots (QDs) of CdSe (core) and CdSe/ZnS (core/shell) were synthesized at different temperatures with different growth periods. Optical properties (i.e., UV/Vis spectra and photoluminescent emission spectra) of the resulting QDs were investigated. The shell-protected CdSe/ZnS QDs exhibited higher photoluminescent (PL) efficiency and stability than their corresponding CdSe core QDs. Ligand exchange with various thiol molecules was performed to replace the initial surface passivation ligands, that is, trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP), and the optical properties of the surface-modified QDs were studied. The thiol ligand molecules in this study included 1,4-benzenedimethanethiol, 1,16-hexadecanedithiol, 1,11-undecanedithiol, biphenyl-4,4′-dithiol, 11-mercapto-1-undecanol, and 1,8-octanedithiol. After the thiol functionalization, the CdSe/ZnS QDs exhibited significantly enhanced PL efficiency and storage stability. Besides surface passivation effect, such enhanced performance of thiol-functionalized QDs could be due to cross-linked assembly formation of dimer/trimer clusters, in which QDs are linked by dithiol molecules. Furthermore, effects of ligand concentration, type of ligand, and heating on the thiol stabilization of QDs were also discussed. © 2014 Huaping Zhu et al.
Keywords: Emission spectroscopy; Ligands; Molecules; Semiconductor quantum dots; 1 ,4-Benzenedimethanethiol; Ligand concentration; Photoluminescent efficiencies; Photoluminescent emission; Surface passivation; Surface passivation effects; Thiol-functionalization; Trioctylphosphine oxide; Optical properties

Activation of innate immune responses by Haemophilus influenzae lipooligosaccharide - Choi, J.; Cox, A.D.; Li, J.; McCready, W.; Ulanova, M. (Clinical and Vaccine Immunology, 2014)
A Gram-negative pathogen Haemophilus influenzae has a truncated endotoxin known as lipooligosaccharide (LOS). Recent studies on H. influenzae LOS highlighted its structural and compositional implications for bacterial virulence; however, the role of LOS in the activation of innate and adaptive immunity is poorly understood. THP-1 monocytes were stimulated with either lipopolysaccharide (LPS) from Escherichia coli or LOS compounds derived from H. influenzae Eagan, Rd, and Rd lic1 lpsA strains. Cell surface expression of key antigen-presenting, costimulatory, and adhesion molecules, as well as gene expression of some cytokines and pattern recognition receptors, were studied. Eagan and Rd LOS had a lower capacity to induce the expression of ICAM-1, CD40, CD58, tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) compared to LPS. In contrast, antigen-presenting (HLA-ABC or HLA-DR) and costimulatory (CD86) molecules and NOD2 were similarly upregulated in response to LOS and LPS. LOS from a mutant Rd strain (Rd lic1 lpsA) consistently induced higher expression of innate immune molecules than the wild-type LOS, suggesting the importance of phosphorylcholine and/or oligosaccharide extension in cellular responses to LOS. An LOS compound with a strong ability to upregulate antigen-presenting and costimulatory molecules combined with a low proinflammatory activity may be considered a vaccine candidate to immunize against H. influenzae. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Keywords: caspase recruitment domain protein 15; caspase recruitment domain protein 4; CD40 antigen; CD86 antigen; HLA A antigen; HLA B antigen; HLA C antigen; HLA DR antigen; intercellular adhesion molecule 1; interleukin 10; interleukin 1beta; lipid A; lipooligosaccharide; lymphocyte function associated antigen 3; pattern recognition receptor; toll like receptor 4; tumor necrosis factor alpha; adaptive immunity; antigen presentation; article; bacterial strain; controlled study; cytokine response; Escherichia coli; gene expression; Haemophilus influenzae; human; human cell; immunostimulation; innate immunity; matrix assisted laser desorption ionization time of flight mass spectrometry; monocyte; nonhuman; priority journal; protein expression; upregulation

A review of invasive Haemophilus influenzae disease in the Indigenous populations of North America - Tsang, R.S.W.; Bruce, M.G.; Lem, M.; Barreto, L.; Ulanova, M. (Epidemiology and Infection, 2014)
Historically, the highest incidence rates of invasive Haemophilus influenzae disease in the world were found in North American and Australian Indigenous children. Although immunization against H. influenzae type b (Hib) led to a marked decrease in invasive Hib disease in countries where it was implemented, this disease has not been eliminated and its rates in Indigenous communities remain higher than in the general North American population. In this literature review, we examined the epidemiology of invasive H. influenzae disease in the pre-Hib vaccine era, effect of carriage on disease epidemiology, immune response to H. influenzae infection and Hib vaccination in Indigenous and Caucasian children, and the changing epidemiology after Hib conjugate vaccine has been in use for more than two decades in North America. We also explored reasons behind the continued high rates of invasive H. influenzae disease in Indigenous populations in North America. H. influenzae type a (Hia) has emerged as a significant cause of severe disease in North American Indigenous communities. More research is needed to define the genotypic diversity of Hia and the disease burden that it causes in order to determine if a Hia vaccine is required to protect the vulnerable populations. Copyright © Cambridge University Press 2014.
Keywords: ampicillin; antibody; cefotaxime; cephalosporin derivative; Haemophilus influenzae vaccine; immunoglobulin G; rifampicin; antibiotic therapy; antibody response; bacterial virulence; chemoprophylaxis; disease predisposition; disease transmission; Haemophilus infection; Haemophilus influenzae; health care need; human; immune response; immunization; incidence; indigenous people; infection rate; invasive species; North America; post exposure prophylaxis; review; risk factor; socioeconomics

Nanomicellar formulation of coenzyme Q10 (Ubisol-Q10) effectively blocks ongoing neurodegeneration in the mouse 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model: Potential use as an adjuvant treatment in Parkinson's disease - Sikorska, M.; Lanthier, P.; Miller, H.; Beyers, M.; Sodja, C.; Zurakowski, B.; Gangaraju, S.; Pandey, S.; Sandhu, J.K. (Neurobiology of Aging, 2014)
Although the support for the use of antioxidants, such as coenzyme Q10 (CoQ10), to treat Parkinson's disease (PD) comes from the extensive scientific evidence, the results of conducted thus far clinical trials are inconclusive. It is assumed that the efficacy of CoQ10 is hindered by insolubility, poor bioavailability, and lack of brain penetration. We have developed a nanomicellar formulation of CoQ10 (Ubisol-Q10) with improved properties, including the brain penetration, and tested its effectiveness in mouse MPTP (1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine) model with the objectives to assess its potential use as an adjuvant therapy for PD. We used a subchronic MPTP model (5-daily MPTP injections), characterized by 50% loss of dopamine neurons over a period of 28days. Ubisol-Q10 was delivered in drinking water. Prophylactic application of Ubisol-Q10, started 2weeks before the MPTP exposure, significantly offset the neurotoxicity (approximately 50% neurons died in MPTP group vs. 17% in MPTP+ Ubisol-Q10 group by day 28). Therapeutic application of Ubisol-Q10, given after the last MPTP injection, was equally effective. At the time of intervention on day 5 nearly 25% of dopamine neurons were already lost, but the treatment saved the remaining 25% of cells, which otherwise would have died by day 28. This was confirmed by cell counts, analyses of striatal dopamine levels, and improved animals' motor skill on a beam walk test. Similar levels of neuroprotection were obtained with 3 different Ubisol-Q10 concentrations tested, that is, 30mg, 6mg, or 3mg CoQ10/kg body weight/day, showing clearly that high doses of CoQ10 were not required to deliver these effects. Furthermore, the Ubisol-Q10 treatments brought about a robust astrocytic activation in the brain parenchyma, indicating that astroglia played an active role in this neuroprotection. Thus, we have shown for the first time that Ubisol-Q10 was capable of halting the neurodegeneration already in progress; however, to maintain it a continuous supplementation of Ubisol-Q10 was required. The pathologic processes initiated by MPTP resumed if supplementation was withdrawn. We suggest that in addition to brain delivery of powerful antioxidants, Ubisol-Q10 might have also supported subcellular oxidoreductase systems allowing them to maintain a favorable cellular redox status, especially in astroglia, facilitating their role in neuroprotection. Based on this data further clinical testing of this formulation in PD patients might be justifiable. © 2014 Elsevier Inc.

Lipids isolated from the cultivated red alga Chondrus crispus inhibit nitric oxide production - Banskota, A.H.; Stefanova, R.; Sperker, S.; Lall, S.; Craigie, J.S.; Hafting, J.T. (Journal of Applied Phycology, 2014)
A MeOH extract of cultivated Chondrus crispus showed dose-dependent nitric oxide (NO) inhibition of lipopolysaccharide-induced NO production in macrophage RAW264.7 cells. NO inhibition-guided fractionation of the extract led to identification of eicosapentaenoic acid (EPA, 1), arachidonic acid (AA, 2), lutein (3), and eight galactolipids as active components. Based on spectral analysis, the isolated galactolipids were identified as (2S)-1,2-bis-O-eicosapentaenoyl-3-O-β-d-galactopyranosylglycerol (4), (2S)-1-O-eicosapentaenoyl-2-O-arachidonoyl-3-O-β-d-galactopyranosylglycerol (5), (2S)-1-O-(6Z,9Z,12Z,15Z-octadecatetranoyl)-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (6), (2S)-1-O-eicosapentaenoyl-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (7), (2S)-1,2-bis-O-arachidonoyl-3-O-β-d-galactopyranosylglycerol (8), (2S)-1-O-arachidonoyl-2-O-palmitoyl-3-O-β-d-galactopyranosylglycerol (9), (2S)-1-O-eicosapentaenoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (10), and (2S)-1-O-arachidonoyl-2-O-palmitoyl-3-O-(β-d-galactopyranosyl-6-1α-d-galactopyranosyl)-glycerol (11). All the isolated compounds showed significant NO inhibitory activity. This is the first report of the isolation and identification of individual galactolipids from C. crispus. Moreover, (2S)-1,2-bis-O-arachidonoyl -3-O-β-d-galactopyranosylglycerol (8) is a novel compound.
Keywords: Cultivated Chondrus crispus; Nitric oxide; icosapentaenoic acid; Arachidonic acid; Lutein; Galactolipid; Monogalactosyldiacylglycerol; Digalactosyldiacylglycerol

Evidence that a synthetic amyloid-ß oligomer-binding peptide (ABP) targets amyloid-ß deposits in transgenic mouse brain and human Alzheimer's disease brain - Chakravarthy, B.; Ito, S.; Atkinson, T.; Gaudet, C.; Ménard, M.; Brown, L.; Whitfield, J. (Biochemical and Biophysical Research Communications, 2014)
The synthetic ~5kDa ABP (amyloid-ß binding peptide) consists of a region of the 228kDa human pericentrioloar material-1 (PCM-1) protein that selectively and avidly binds in vitro Aβ1-42 oligomers, believed to be key co-drivers of Alzheimer's disease (AD), but not monomers (Chakravarthy et al., (2013) [3]). ABP also prevents Aß1-42 from triggering the apoptotic death of cultured human SHSY5Y neuroblasts, likely by sequestering Aß oligomers, suggesting that it might be a potential AD therapeutic. Here we support this possibility by showing that ABP also recognizes and binds Aβ1-42 aggregates in sections of cortices and hippocampi from brains of AD transgenic mice and human AD patients. More importantly, ABP targets Aβ1-42 aggregates when microinjected into the hippocampi of the brains of live AD transgenic mice. © 2014.
Keywords: amyloid beta protein; amyloid beta protein[1-42]; amyloid beta protein[25-35]; oligomer; synthetic peptide; Alzheimer disease; animal experiment; animal model; animal tissue; apoptosis; article; brain; brain cortex; brain tissue; controlled study; hippocampus; human; human tissue; immunohistology; microinjection; mouse; neuroblast; nonhuman; nucleotide sequence; priority journal; protein aggregation; protein targeting; transgenic mouse; Mus musculus; AD transgenic mice; Alzheimer's disease; Amyloid binding peptide; Aβ(1-42) oligomers; Human AD brains; PCM-1 protein; Aged; Aged, 80 and over; Alzheimer Disease; Amino Acid Sequence; Amyloid beta-Peptides; Animals; Autoantigens; Brain; Cell Cycle Proteins; Cell Line; Humans; Male; Mice; Mice, Transgenic; Middle Aged; Molecular Sequence Data; Peptide Fragments; Peptides; Protein Binding

Higher efficacy of dietary DHA provided as a phospholipid than as a triglyceride for brain DHA accretion in neonatal piglets - Liu, L.; Bartke, N.; Van Daele, H.; Lawrence, P.; Qin, X.; Park, H.G.; Kothapalli, K.; Windust, A.; Bindels, J.; Wang, Z.; Brenna, J.T. (Journal of Lipid Research, 2014)
Long-chain PUFAs (LCPUFAs) occur in foods primarily in the natural lipid classes, triacylglycerols (TAGs) or phospholipids (PLs). We studied the relative efficacy of the neural omega-3 DHA provided in formula to growing piglets as a dose of 13C-DHA bound to either TAG or phosphatidylcholine (PC). Piglets were assigned to identical formula-based diets from early life and provided with TAG-13C-DHA or PC-13C-DHA orally at 16 days. Days later, piglet organs were analyzed for 13C-DHA and other FA metabolites. PC-13C-DHA was 1.9-fold more efficacious for brain gray matter DHA accretion than TAG-13C-DHA, and was similarly more efficacious in gray matter synaptosomes, retina, liver, and red blood cells (RBCs). Liver labeling was greatest, implying initial processing in that organ followed by export to other organs, and suggesting that transfer from gut to bloodstream to liver in part drove the difference in relative efficacy for tissue accretion. Apparent retroconversion to 22:5n-3 was more than double for PC-13C-DHA and was more prominent in neural tissue than in liver or RBCs. These data directly support greater efficacy for PC as a carrier for LCPUFAs compared with TAG, consistent with previous studies of arachidonic acid and DHA measured in other species. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.
Keywords: docosahexaenoic acid; phosphatidylcholine; phospholipid; triacylglycerol; animal experiment; animal tissue; article; body weight; brain cortex; controlled study; diet supplementation; erythrocyte; female; gray matter; liver; male; newborn; nonhuman; piglet; priority journal; retina; synaptosome; tissue distribution

Highly regenerable mussel-inspired Fe3O 4@Polydopamine-Ag core-shell microspheres as catalyst and adsorbent for methylene blue removal - Xie, Y.; Yan, B.; Xu, H.; Chen, J.; Liu, Q.; Deng, Y.; Zeng, H. (ACS Applied Materials and Interfaces, 2014)
We report a facile method to synthesize Fe3O 4@polydopamine (PDA)-Ag core-shell microspheres. Ag nanoparticles (NPs) are deposited on PDA surfaces via in situ reduction by mussel-inspired PDA layers. High catalytic activity and fast adsorption of a model dye methylene blue (MB) at different pH values are achieved mainly due to the presence of monodisperse Ag NPs and electrostatic interactions between PDA and MB. The as-prepared Fe3O4@PDA-Ag microspheres also show high cyclic stability (>27 cycles), good acid stability, and fast regeneration ability, which can be achieved efficiently within several minutes by using NaBH4 as the desorption agent, showing great potentials in a wide range of applications. © 2014 American Chemical Society.
Keywords: Adsorption; Aromatic compounds; Microspheres; Molluscs; Water treatment; Cyclic stability; Dye removal; Polydopamine; regeneration ability; Situ reduction; Silver

Acetylsalicylic acid (ASA) increases the solubility of cholesterol when incorporated in lipid membranes - Alsop, R.J.; Barrett, M.A.; Zheng, S.; Dies, H.; Rheinstädter, M.C. (Soft Matter, 2014)
Cholesterol has been well established as a mediator of cell membrane fluidity. By interacting with lipid tails, cholesterol causes the membrane tails to be constrained thereby reducing membrane fluidity, well known as the condensation effect. Acetylsalicylic acid (ASA), the main ingredient in aspirin, has recently been shown to increase fluidity in lipid bilayers by primarily interacting with lipid head groups. We used high-resolution X-ray diffraction to study both ASA and cholesterol coexisting in model membranes of dimyristoylphosphatidylcholine (DMPC). While a high cholesterol concentration of 40 mol% cholesterol leads to the formation of immiscible cholesterol bilayers, as was reported previously, increasing the amount of ASA in the membranes between 0 to 12.5 mol% was found to significantly increase the fluidity of the bilayers and dissolve the cholesterol plaques. We, therefore, present experimental evidence for an interaction between cholesterol and ASA on the level of the cell membrane at elevated levels of cholesterol and ASA. © 2014 the Partner Organisations.
Keywords: Cell membranes; Cytology; Fluidity; Lipid bilayers; X ray diffraction; Acetylsalicylic acids; Condensation effects; Dimyristoylphosphatidylcholine; Experimental evidence; High cholesterols; High resolution X ray diffraction; Lipid membranes; Membrane fluidity; Cholesterol

Using electrospray laser desorption ionization mass spectrometry to rapidly examine the integrity of proteins stored in various solutions - Cho, Y.-T.; Huang, M.-Z.; Wu, S.-Y.; Hou, M.-F.; Li, J.; Shiea, J. (Analytical and Bioanalytical Chemistry, 2014)
Electrospray laser desorption ionization mass spectrometry (ELDI/MS) allows the rapid desorption and ionization of proteins from solutions under ambient conditions. In this study, we have demonstrated the use of ELDI/MS to efficiently examine the integrity of the proteins stored in various solutions before they were further used for other biochemical tests. The protein standards were prepared in the solutions containing buffers, organic salts, inorganic salts, strong acid, strong base, and organic solvents, respectively, to simulate those collected from solvent extraction, filtration, dialysis, or chromatographic separation. Other than the deposit of a drop of the sample solution on the metallic sample plate in an ELDI source, no additional sample pretreatment is needed. The sample drop was then irradiated with a pulsed laser; this led to desorption of the analyte molecules, which subsequently entered the ESI plume to undergo postionization. Because adjustment of the composition of the sample solution is unnecessary, this technique appears to be useful for rapidly evaluating the integrity of proteins after storage or prior to further biochemical treatment. In addition, when using acid-free and low-organic-solvent ESI solutions for ELDI/MS analysis, the native conformations of the proteins in solution could be detected. © Springer-Verlag Berlin Heidelberg 2013.
Keywords: Conformations; Desorption; Drops; Filtration; Ionization; Liquid chromatography; Mass spectrometry; Proteins; Solvent extraction; Additional samples; Ambient conditions; Biochemical treatments; Chromatographic separations; ELDI; Laser desorption; Laser desorption ionization mass spectrometry; Native conformation; Electrospray ionization

Pitting corrosion characterization of wrought Stellite alloys in Green Death Solution with immersion test and extreme value analysis model - Zhang, X.Z.; Liu, R.; Chen, K.Y.; Yao, M.X. (Journal of Materials Engineering and Performance, 2014)
This article presents a study of the corrosion behavior of two wrought Stellite alloys, Stellite 6B, and Stellite 6K, in Green Death solution, utilizing the extreme value analysis (EVA) model, which is a statistics tool developed based on the Gumbel distribution. Green Death solution a typical oxidized testing solution used in industry for assessing the corrosion resistance of materials. The data of maximum pit depths are obtained from the immersion tests on these alloys for various exposure periods. The top ten maximum pit depths in each specimen surface after the immersion test are measured using a surface texture and contour measuring instrument. These data are the input parameters of the EVA model and the outcomes of the model are the extreme values (minimum thickness) required for the alloys under a given service condition. It is shown that Stellite 6K, which contains higher carbon content but smaller-size carbides, exhibits better corrosion resistance in regard to the extreme value. The results and mechanisms of Stellite 6B and Stellite 6K in Green Death solution corrosion are discussed. © 2014 ASM International.
Keywords: Carbides; Corrosion resistance; Pitting; Solid solutions; Stellite; Value engineering; Corrosion behavior; Corrosion characterization; Extreme value analysis; Gumbel distribution; Measuring instruments; Pit depths; Service conditions; Stellite alloy; Alloys

Towards the development of a surface plasmon resonance assay to evaluate the glycosylation pattern of monoclonal antibodies using the extracellular domains of CD16a and CD64 - Dorion-Thibaudeau, J.; Raymond, C.; Lattová, E.; Perreault, H.; Durocher, Y.; De Crescenzo, G. (Journal of Immunological Methods, 2014)
We here report the production and purification of the extracellular domains of two Fcγ receptors, namely CD16a and CD64, by transient transfection in mammalian cells. The use of these two receptor ectodomains for the development of quantitative assays aiming at controlling the quality of monoclonal antibody production lots is then discussed. More specifically, the development of surface plasmon resonance-based biosensor assays for the evaluation of the glycosylation pattern and the aggregation state of monoclonal antibodies is presented. Our biosensor approach allows discriminating between antibodies harboring different galactosylation profiles as well as to detect low levels (i.e., less than 2%) of monoclonal antibody aggregates. © 2014 Elsevier B.V.
Keywords: CD16a antigen; CD64 antigen; Fc receptor; glycan; immunoglobulin G; monoclonal antibody; unclassified drug; animal cell; antibody production; article; binding kinetics; biosensor; controlled study; gel permeation chromatography; glycosylation; human; human cell; in vitro study; mammal cell; matrix assisted laser desorption ionization time of flight mass spectrometry; nonhuman; priority journal; protein purification; quantitative assay; surface plasmon resonance; transient transfection; Mammalia

Development of residual stresses during electron beam processing - Demaria, C.; Paźsdzior, P.; Johnston, A.; Djokic, D.; Hubert, P. (Journal of Strain Analysis for Engineering Design, 2014)
In order to further advance the state of the art in the electron beam processing of polymers and composites, it is necessary to better understand the development of cure-induced residual stresses. In situ measurement of electron beam cure-induced stress development is challenging due to the bombardment of specimens with intense beams of very high-voltage electrons. In this study, a custom fixture was designed to measure the deformation of an electron beam-cured specimen during processing and thereby to assess specimen stress state during the curing process. The unbalanced composite specimen consisted of two cured unidirectional carbon-epoxy laminates separated by a thin woven fibreglass carrier, which was infused by a layer of electron beam curable epoxy resin systems (Tactix 123 and CAT B). The out-of-plane specimen deformations were monitored during various electron beam irradiation schedules and subsequent thermal post-cure. The preliminary results confirmed that the apparatus was not affected by the irradiation and was capable of accurately measuring the specimen warpage during the cure. It was also shown that the electron beam-cured specimens exhibit a reduced residual stress state compared to equivalent thermally cured specimens. It was observed that the irradiation dose rate applied to a specimen is the main factor in the difference in the way residual stresses develop during electron beam curing. Furthermore, the results suggest that there is a direct relation between the stress-free temperature (TSF) and the temperature of the specimen at gelation (TGEL). © IMechE 2014.
Keywords: Composite materials; Deformation; Electron beams; Epoxy resins; Gelation; Irradiation; Residual stresses; Carbon-epoxy laminates; Composite specimens; Electron beam curing; Electron beam irradiation; Electron beam processing; In-situ measurement; Residual stress state; Stress-free temperature; Curing

Evolution of antiferromagnetic susceptibility under uniaxial pressure in Ba(Fe1 x Cox) 2 As2 - Dhital, C.; Hogan, T.; Yamani, Z.; Birgeneau, R.J.; Tian, W.; Matsuda, M.; Sefat, A.S.; Wang, Z.; Wilson, S.D. (Physical Review B - Condensed Matter and Materials Physics, 2014)
Neutron diffraction measurements are presented measuring the responses of both magnetic and structural order parameters of parent and lightly Co-doped Ba(Fe1 xCox)2As2 under the application of uniaxial pressure. We find that the uniaxial pressure induces a thermal shift in the onset of antiferromagnetic order that grows as a percentage of TN as Co doping is increased and the superconducting phase is approached. Additionally, as uniaxial pressure is increased within parent and lightly doped Ba(Fe1 xCox)2As2 on the first-order side of the tricritical point, we observe a decoupling between the onsets of the orthorhombic structural distortion and antiferromagnetism. Our findings place needed constraints on models exploring the nematic susceptibility of the bilayer pnictides in the tetragonal, paramagnetic regime. © 2014 American Physical Society.

Biofuels and Bioproducts Produced through Microbial Conversion of Biomass - Yang, T.C.; Kumaran, J.; Amartey, S.; Maki, M.; Li, X.; Lu, F.; Qin, W. (Bioenergy Research: Advances and Applications, 2014)
Lignocellulose is a complex polymer composed of intertwined cellulose, hemicelluloses and lignin substances. Research on conversion of lignocellulosic biomass into biofuels and other bioproducts is on the increase recently. Significant advances have been made toward the development of various technologies for pretreatment of the lignocellulosic biomass. The conversion of lignocellulose, therefore, could offer the advantage of cheaper fermentable sugars for the production of biofuels and chemicals. However, due to the complex structure of lignocellulose biomass, development of an efficient and cost-effective pretreatment process is necessary. Also, efficient enzyme hydrolysis of carbohydrates into simple sugars allows higher reaction rates and increased yields of accessible sugars (hexoses and pentoses). Furthermore, an efficient microorganism, capable of degrading biomass efficiently and in high yields, is necessary to facilitate a sustainable and economically viable manufacturing of biofuels and bioproducts from lignocellulosic raw materials. Currently, a number of pretreatment methods have been developed, with only a few being optimized on an industrial scale. This review provides practical examples and gives a broad overview of the current status of biofuels and bioproducts produced through microbial conversion of lignocellulosic biomass. Both biological and nonbiological pretreatments of biomass, prior to hydrolysis, and different processes of microbial-mediated biomass conversion have been discussed. Furthermore, the development of novel microorganism strains, through genetic engineering, for biomass conversion and the pros and cons of commonly used microorganisms in biomass conversion have also been discussed. © 2014 Elsevier B.V. All rights reserved.

High-mobility solution-processed zinc oxide thin films on silicon nitride - Benlamri, M.; Bothe, K.M.; Ma, A.M.; Shoute, G.; Afshar, A.; Sharma, H.; Mohammadpour, A.; Gupta, M.; Cadien, K.C.; Tsui, Y.Y.; Shankar, K.; Barlage, D.W. (Physica Status Solidi - Rapid Research Letters, 2014)
A high effective electron mobility of 33 cm2 V-1 s-1 was achieved in solution-processed undoped zinc oxide (ZnO) thin films. The introduction of silicon nitride (Si3N4) as growth substrate resulted in a mobility improvement by a factor of 2.5 with respect to the commonly used silicon oxide (SiO2). The solution-processed ZnO thin films grown on Si3N4, prepared by low-pressure chemical vapor deposition, revealed bigger grain sizes, lower strain and better crystalline quality in comparison to the films grown on thermal SiO2. These results show that the nucleation and growth mechanisms of solution-processed films are substrate dependent and affect the final film structure accordingly. The substantial difference in electron mobilities suggests that, in addition to the grain morphology and crystalline structure effects, defect chemistry is a contributing factor that also depends on the particular substrate. In this respect, interface trap densities measured in high-κ HfO2/ZnO MOSCAPs were about ten times lower in those fabricated on Si3N4 substrates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electron-electron interaction mediated indirect coupling of electron and magnetic ion or nuclear spins in self-assembled quantum dots - Mendes, U.C.; Korkusinski, M.; Hawrylak, P. (Physical Review B - Condensed Matter and Materials Physics, 2014)
We show here the existence of the indirect coupling of electron and magnetic or nuclear ion spins in self-assembled quantum dots mediated by electron-electron interactions. With a single localized spin placed in the center of the dot, only the spins of electrons occupying the zero angular momentum states couple directly to the localized spin. We show that when the electron-electron interactions are included, the electrons occupying finite angular momentum orbitals interact with the localized spin. This effective interaction is obtained using exact diagonalization of the microscopic Hamiltonian as a function of the number of electronic shells, shell spacing, and anisotropy of the electron-Mn exchange interaction. The effective interaction can be engineered to be either ferromagnetic or antiferromagnetic by tuning the parameters of the quantum dot. © 2014 American Physical Society.

Inhibition activity of antifreeze proteins with natural gas hydrates in saline and the light crude oil mimic, heptane - Sharifi, H.; Walker, V.K.; Ripmeester, J.; Englezos, P. (Energy and Fuels, 2014)
For practical purposes, kinetic hydrate inhibitors must perform predictably in the presence of oil as well as saline and high driving forces, but such deterministic behavior is rarely achieved. Here, we evaluated two biological inhibitors, type I and type III antifreeze proteins (AFPs I and III), under these exacting conditions using a double high-pressure crystallizer apparatus and additionally assayed using high-pressure micro-differential scanning calorimetry. The two AFP types behaved somewhat differently under these environmental conditions. The addition of AFP I reduced natural gas hydrate induction time, whereas AFP III had no impact on hydrate crystal nucleation. Nonetheless, for both AFPs, gas hydrate growth was significantly inhibited to ∼50% of that found in control experiments. Once hydrate had formed, decomposition was slower and started later. Thus, gas hydrates formed in the presence of APF I and III appeared to remain stable outside the hydrate stable zone, an observation that has also been noted for other inhibitors. Our observations have potential implications for the use of biological inhibitors under subsea pipeline conditions. © 2014 American Chemical Society.
Keywords: Differential scanning calorimetry; Hydration; Natural gas; Antifreeze protein; Crystal nucleation; Deterministic behavior; Environmental conditions; Inhibition activity; Kinetic hydrate inhibitors; Scanning calorimetry; Sub-sea pipelines; Gas hydrates

A review of graphene-based nanostructural materials for both catalyst supports and metal-free catalysts in PEM fuel cell oxygen reduction reactions - Zhou, X.; Qiao, J.; Yang, L.; Zhang, J. (Advanced Energy Materials, 2014)
A comprehensive overview and description of graphene-based nanomaterials explored in recent years for catalyst supports and metal-free catalysts for polymer electrolyte membrane (PEM) fuel cell oxygen reduction reactions (ORR) is presented. The catalyst material structures/morphologies, material selection, and design for synthesis, catalytic performance, catalytic mechanisms, and theoretical approaches for catalyst down-selection and catalyzed ORR mechanisms are emphasized with respect to the performance of ORR catalysts in terms of both activity and stability. When graphene-based materials, including graphene and doped graphene, are used as the supporting materials for both Pt/Pt alloy catalysts and non-precious metal catalyst, the resulting ORR catalysts can give superior catalyst activity and stability compared to those of conventional carbon-supported catalysts; when they are used as metal-free ORR catalysts, significant catalytic activity and stability are observed. The nitrogen-doped graphene materials even show superior performance compared to supported metal catalysts. Challenges including the lack of material mass production, unoptimized catalyst structure/morphology, insufficient fundamental understanding, and testing tools/protocols for performance optimization and validation are identified, and approaches to address these challenges are suggested. A comprehensive overview and description of graphene-based nanomaterials for catalyst supports and metal-free catalysts for polymer electrolyte membrane (PEM) fuel cell oxygen reduction reactions (ORR) is presented. The catalyst material selection, design, synthesis, and characterization, as well as a theoretical understanding of the catalysis process and mechanisms are discussed. The challenges and their corresponding approaches, in addition to directions for future perspectives and research are suggested. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords: Catalysis; Catalyst supports; Characterization; Electrocatalysts; Electrolytic reduction; Fuel cells; Graphene; Materials; Metals; Nanostructured materials; Polyelectrolytes; Proton exchange membrane fuel cells (PEMFC); Carbon-supported catalysts; Nanostructural materials; Nitrogen-doped graphene; Non-precious metal catalysts; Oxygen reduction reaction; Performance optimizations; Polymer electrolyte membranes; Supported-metal catalysts; Catalyst activity

An experimental investigation of the long-term stability of triple-point-of-water cells - Hill, K.D. (International Journal of Thermophysics, 2014)
Contamination of triple-point-of-water (TPW) cells by the chemical components of the borosilicate glass that contains the water is now widely recognized as the principal contributor to long-term drift of the cell temperature. To add to the available experimental data, a comparison of 24 TPW cells of various ages (from 10 years to 59 years), manufacturers (NRC, Jarrett, Isotech), and materials (borosilicate glass and fused quartz) was undertaken in 2013. Twelve cells from this group were compared to one another in 1997. By comparing the current inter-cell temperature differences to those determined 16 years earlier, it was found that some cells have remained stable, others have become colder (as might be expected from ongoing dissolution of the glass), and one or two show an apparent increase in temperature that seems anomalous. Also included among the 24 cells are five cells of borosilicate glass and five of fused quartz that were purchased 10 years ago. By comparing the relative temperature differences among this group of borosilcate and fused-quartz-encapsulated cells to the values obtained when they were last compared 6 years ago, it was found that the average temperature of the borosilcate group of cells decreases by (Formula presented.), in reasonable agreement with an average drift of (Formula presented.) suggested 12 years ago. It was concluded that fused quartz is the superior container for TPW cells. © 2014 Her Majesty the Queen in Rights of Canada.

Characterizing the rate and coherence of single-electron tunneling between two dangling bonds on the surface of silicon - Shaterzadeh-Yazdi, Z.; Livadaru, L.; Taucer, M.; Mutus, J.; Pitters, J.; Wolkow, R.A.; Sanders, B.C. (Physical Review B - Condensed Matter and Materials Physics, 2014)
We devise a scheme to characterize tunneling of an excess electron shared by a pair of tunnel-coupled dangling bonds on a silicon surface - effectively a two-level system. Theoretical estimates show that the tunneling should be highly coherent but too fast to be measured by any conventional techniques. Our approach is instead to measure the time-averaged charge distribution of our dangling-bond pair by a capacitively coupled atomic-force-microscope tip in the presence of both a surface-parallel electrostatic potential bias between the two dangling bonds and a tunable midinfrared laser capable of inducing Rabi oscillations in the system. With a nonresonant laser, the time-averaged charge distribution in the dangling-bond pair is asymmetric as imposed by the bias. However, as the laser becomes resonant with the coherent electron tunneling in the biased pair the theory predicts that the time-averaged charge distribution becomes symmetric. This resonant symmetry effect should not only reveal the tunneling rate, but also the nature and rate of decoherence of single-electron dynamics in our system. © 2014 American Physical Society.

Identification and characterisation of glycoproteins on the spore surface of Clostridium difficile - Strong, Philippa C. R.; Fulton, Kelly M.; Aubry, Annie; Foote, Simon; Twine, Susan M.; Logan, Susan M. (Journal of Bacteriology, 2014)
In this study, we identify a major spore surface protein, BclA, and provide evidence that this protein is glycosylated. Following extraction of the spore surface, solubilized proteins were separated by one-dimensional PAGE and stained with glycostain to reveal a reactive high-molecular-mass region of approximately 600 kDa. Tandem mass spectrometry analysis of in-gel digests showed this band to contain peptides corresponding to a putative exosporangial glycoprotein (BclA3) and identified a number of glycopeptides modified with multiple N-acetyl hexosamine moieties and, in some cases, capped with novel glycans. In addition, we demonstrate that the glycosyltransferase gene sgtA (gene CD3350 in strain 630 and CDR3194 in strain R20291), which is located immediately upstream of the bclA3 homolog, is involved in the glycosylation of the spore surface, and is cotranscribed with bclA3. The presence of anti-β-O-GlcNAc-reactive material was demonstrated on the surface of spores by immunofluorescence and in surface extracts by Western blotting, although each strain produced a distinct pattern of reactivity. Reactivity of the spore surface with the anti-β-O-GlcNAc antibody was abolished in the 630 and R20291 glycosyltransferase mutant strains, while complementation with a wild-type copy of the gene restored the β-O-GlcNAc reactivity. Phenotypic testing of R20291 glycosyltransferase mutant spores revealed no significant change in sensitivity to ethanol or lysozyme. However, a change in the resistance to heat of R20291 glycosyltransferase mutant spores compared to R20291 spores was observed, as was the ability to adhere to and be internalized by macrophages.
Keywords: Clostridium difficile; spores; glycoprotein; glycosyltransferase

Anti-frameshifting ligand reduces the conformational plasticity of the SARS virus pseudoknot - Ritchie, D.B.; Soong, J.; Sikkema, W.K.A.; Woodside, M.T. (Journal of the American Chemical Society, 2014)
Programmed -1 ribosomal frameshifting (-1 PRF) stimulated by mRNA pseudoknots regulates gene expression in many viruses, making pseudoknots potential targets for anti-viral drugs. The mechanism by which pseudoknots trigger -1 PRF, however, remains controversial, with several competing models. Recent work showed that high -1 PRF efficiency was linked to high pseudoknot conformational plasticity via the formation of alternate conformers. We tested whether pseudoknots bound with an anti-frameshifting ligand exhibited a similar correlation between conformational plasticity and -1 PRF efficiency by measuring the effects of a ligand that was found to inhibit -1 PRF in the SARS coronavirus on the conformational dynamics of the SARS pseudoknot. Using single-molecule force spectroscopy to unfold pseudoknots mechanically, we found that the ligand binding effectively abolished the formation of alternate conformers. This result extends the connection between -1 PRF and conformational dynamics and, moreover, suggests that targeting the conformational dynamics of pseudoknots may be an effective strategy for anti-viral drug design. © 2014 American Chemical Society.

High-accuracy measurement of the differential scalar polarizability of a Sr+ 88 clock using the time-dilation effect - Dubé, P.; Madej, A.A.; Tibbo, M.; Bernard, J.E. (Physical Review Letters, 2014)
We report a high-accuracy measurement of the differential static scalar polarizability Δα0 of the 5sS1/22-4dD5/22 transition of the Sr+88 ion. The high accuracy is obtained by comparing the micromotion-induced positive scalar Stark shift to the negative time-dilation shift. Measurement of the trap drive frequency where these shifts cancel is used to determine Δα0 without the need to determine the electric field. Δα0 is a critical parameter for the operation of frequency standards as it determines the blackbody radiation frequency shift coefficient, the largest source of uncertainty in the Sr+88 ion clock. The measured value of Δα0 is -4.7938(71)×10-40Jm2/V2. Taking into account the dynamic correction, the blackbody shift at 300 K is 0.24799(37) Hz. The contribution of the blackbody shift coefficient to the uncertainty of the ion standard has been reduced by a factor of 24, from 2×10-17 to 8.3×10-19. The revised total uncertainty of our reference standard is 1.2×10-17, limited by the blackbody field evaluation. An additional benefit of the low uncertainty of Δα0 is the ability to suppress, by a factor of about 200, the net micromotion frequency shifts. © 2014 Published by the American Physical Society.
Keywords: Antenna radiation; Electric fields; Frequency shift keying; Frequency standards; Polarization; Black body radiation; Dynamic correction; Field evaluation; High-accuracy measurements; Reference standard; Scalar polarizability; Shift coefficients; Total uncertainties; Ions

Observing Dirac's classical phase space analog to the quantum state - Bamber, C.; Lundeen, J.S. (Physical Review Letters, 2014)
In 1945, Dirac attempted to develop a "formal probability" distribution to describe quantum operators in terms of two noncommuting variables, such as position x and momentum p [Rev. Mod. Phys. 17, 195 (1945)]. The resulting quasiprobability distribution is a complete representation of the quantum state and can be observed directly in experiments. We measure Dirac's distribution for the quantum state of the transverse degree of freedom of a photon by weakly measuring transverse x so as to not randomize the subsequent p measurement. Furthermore, we show that the distribution has the classical-like feature that it transforms (e.g., propagates) according to Bayes' law. © 2014 American Physical Society.

Protease-resistant single-domain antibodies inhibit Campylobacter jejuni motility - Hussack, Greg; Riazi, Ali; Ryan, Shannon; van Faassen, Henk; Mackenzie, Roger; Tanha, Jamshid; Arbabi-Ghahroudi, Mehdri (Protein Engineering, Design and Selection, 2014)
Camelid heavy-chain antibody variable domains (VHHs) are emerging as potential antimicrobial reagents. We have engineered a previously isolated VHH (FlagV1M), which binds Campylobacter jejuni flagella, for greater thermal and proteolytic stability. Mutants of FlagV1M were obtained from an error-prone polymerase chain reaction library that was panned in the presence of gastrointestinal (GI) proteases. Additional FlagV1M mutants were obtained through disulfide-bond engineering. Each approach produced V HHs with enhanced thermal stability and protease resistance. When the beneficial mutations from both approaches were combined, a hyperstabilized VHH was created with superior stability. The hyperstabilized V HH bound C. jejuni flagella with wild-type affinity and was capable of potently inhibiting C. jejuni motility in assays performed after sequential digestion with three major GI proteases, demonstrating the remarkable stability imparted to the VHH by combining our engineering approaches.
Keywords: C. jejuni; motility; protease resistance; protein stability; VHH

Introduction - Germer, T.A.; Zwinkels, J.C.; Tsai, B.K. (Experimental Methods in the Physical Sciences, 2014)
This chapter is an introduction to Spectrophotometry: Accurate Measurements of the Optical Properties of Materials. It presents a short history of spectrophotometry. A very brief description of the principles of uncertainty analysis is given. Finally, an overview of the rest of the book is given. © 2014 Elsevier Inc.

Development of a cell permeable competitive antagonist of RhoA and CRMP4 binding, TAT-C4RIP, to promote neurite outgrowth - Khazaei, M.R.; Montcalm, S.; Di Polo, A.; Fournier, A.E.; Durocher, Y.; Tone, S.O. (Journal of Molecular Neuroscience, 2014)
Neurons fail to re-extend their processes within the central nervous system environment in vivo, and this is partly because of inhibitory proteins expressed within myelin debris and reactive astrocytes that actively signal to the injured nerve cells to limit their growth. The ability of the trans-acting activator of transcription (TAT) protein transduction domain (PTD) to transport macromolecules across biological membranes raises the possibility of developing it as a therapeutic delivery tool for nerve regeneration. Most studies have produced TAT PTD fusion protein in bacteria, which can result in problems such as protein solubility, the formation of inclusion bodies and the lack of eukaryotic posttranslational modifications. While some groups have investigated the production of TAT PTD fusion protein in mammalian cells, these strategies are focused on generating TAT PTD fusions that are targeted to the secretory pathway, where furin protease as well as other proteases can cleave the TAT PTD. As an alternative to mutating the furin cleavage site in the TAT PTD, we describe a novel method to generate cytosolic TAT PTD fusion proteins and purify them from cell lysates. Here, we use this method to generate TAT-C4RIP, a cell permeable competitive antagonist of binding between the small GTPase RhoA and the cytosolic phosphoprotein Collapsin response mediator protein 4 (CRMP4). We demonstrate that TAT-C4RIP transduces cells in vitro and in vivo and retains its biological activity to attenuate myelin inhibition in an in vitro neurite outgrowth assay. © 2014 Springer Science+Business Media New York.

Conjugate heat transfer of an internally air-cooled nozzle guide vane and shrouds - Jiang, L.; Wu, X.; Zhang, Z. (Advances in Mechanical Engineering, 2014)
In order to assess the life of gas turbine critical components, it is essential to adequately specify their aerothermodynamic working environments. Steady-state analyses of the flow field and conjugate heat transfer of an internally air-cooled nozzle guide vane (NGV) and shrouds of a gas turbine engine at baseline operating conditions are numerically investigated. A high-fidelity CFD model is generated and the simulations are carried out with properly defined boundary conditions. The features of the complicated flow and temperature fields are revealed. In general, the Mach number is lower and the temperature is higher on the NGV pressure side than those on the suction side. There are two high temperature regions on the pressure side, and the temperature across the middle section is relatively low. These findings are closely related to the locations of the holes and outlets of the cooling flow passage, and consistent with the field observations of damaged NGVs. As a technology demonstration, the results provide required information for the life analysis of the NGV/shrouds assembly and improvement of the cooling flow arrangement. © 2014 Leiyong Jiang et al.

Analysis of acquired resistance to metronomic oral topotecan chemotherapy plus pazopanib after prolonged preclinical potent responsiveness in advanced ovarian cancer - Cruz-Muñoz, William; Di Desidero, Teresa; Man, Shan; Xu, Ping; Jaramillo, Maria Luz; Hashimoto, Kae; Collins, Catherine; Banville, Myriam; O'Connor-Mccourt, Maureen D.; Kerbel, Robert S. (Angiogenesis, 2014)
An alternative or follow-up adjunct to conventional maximum tolerated dose (MTD) chemotherapy now in advanced phase III clinical trial assessment is metronomic chemotherapy - the close regular administration of low doses of drug with no prolonged breaks. A number of preclinical studies have shown metronomic chemotherapy can cause long term survival of mice with advanced cancer, including metastatic disease, in the absence of overt toxicity, especially when combined with targeted antiangiogenic drugs. However, similar to MTD chemotherapy acquired resistance eventually develops, the basis of which is unknown. Using a preclinical model of advanced human ovarian (SKOV-3-13) cancer in SCID mice, we show that acquired resistance can develop after terminating prolonged (over 3 months) successful therapy utilizing daily oral metronomic topotecan plus pazopanib, an oral antiangiogenic tyrosine kinase inhibitor (TKI). Two resistant sublines were isolated from a single mouse, one from a solid tumor (called KH092-7SD, referred to as 7SD) and another from ascites tumor cells (called KH092-7AS, referred to as 7AS). Using these sublines we show acquired resistance to the combination treatment is due to tumor cell alterations that confer relative refractoriness to topotecan. The resistant phenotype is heritable, associated with reduced cellular uptake of topotecan and could not be reversed by switching to MTD topotecan or to another topoisomerase-1 inhibitor, CPT-11, given either in a metronomic or MTD manner nor switching to another antiangiogenic drug, e.g. The anti-VEGFR-2 antibody, DC101, or another TKI, sunitinib. Thus, in this case cross resistance seems to exist between MTD and metronomic topotecan, the basis of which is unknown. However, gene expression profiling revealed several potential genes that are stably upregulated in the resistant lines, that previously have been implicated in resistance to various chemotherapy drugs, and which, therefore, may contribute to the drug resistant phenotype.
Keywords: Metastasis; Ovarian cancer; Chemotherapy; Topotecan; Pazopanib; Resistance

Carrier localization and electronic phase separation in a doped spin-orbit-driven Mott phase in Sr3 (Ir1-x Ru x)2O7 - Dhital, C.; Hogan, T.; Zhou, W.; Chen, X.; Ren, Z.; Pokharel, M.; Okada, Y.; Heine, M.; Tian, W.; Yamani, Z.; Opeil, C.; Helton, J.S.; et al. (Nature Communications, 2014)
Interest in many strongly spin-orbit-coupled 5d-transition metal oxide insulators stems from mapping their electronic structures to a J eff=1/2 Mott phase. One of the hopes is to establish their Mott parent states and explore these systems' potential of realizing novel electronic states upon carrier doping. However, once doped, little is understood regarding the role of their reduced Coulomb interaction U relative to their strongly correlated 3d-electron cousins. Here we show that, upon hole-doping a candidate Jeff=1/2 Mott insulator, carriers remain localized within a nanoscale phase-separated ground state. A percolative metal-insulator transition occurs with interplay between localized and itinerant regions, stabilizing an antiferromagnetic metallic phase beyond the critical region. Our results demonstrate a surprising parallel between doped 5d- and 3d-electron Mott systems and suggest either through the near-degeneracy of nearby electronic phases or direct carrier localization that U is essential to the carrier response of this doped spin-orbit Mott insulator. © 2014 Macmillan Publishers Limited. All rights reserved.
Keywords: iridium; ruthenium; strontium; correlation; Coulomb criterion; nanotechnology; phase transition; article; controlled study; crystal structure; electronics; high temperature; low temperature; mott phase; neutron diffraction; neutron scattering; phase separation; phase transition; roentgen spectroscopy; transition temperature; X ray powder diffraction

Wide-field hubble space telescope observations of the globular cluster system in NGC 1399 - Puzia, T.H.; Paolillo, M.; Goudfrooij, P.; Maccarone, T.J.; Fabbiano, G.; Angelini, L. (The Astrophysical Journal, 2014)
We present a comprehensive high spatial resolution imaging study of globular clusters (GCs) in NGC 1399, the central giant elliptical cD galaxy in the Fornax galaxy cluster, conducted with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). Using a novel technique to construct drizzled point-spread function libraries for HST/ACS data, we accurately determine the fidelity of GC structural parameter measurements from detailed artificial star cluster experiments and show the superior robustness of the GC half-light radius, rh, compared with other GC structural parameters, such as King core and tidal radius. The measurement of rh for the major fraction of the NGC 1399 GC system reveals a trend of increasing r h versus galactocentric distance, R gal, out to about 10 kpc and a flat relation beyond. This trend is very similar for blue and red GCs, which are found to have a mean size ratio of r h, red/r h, blue = 0.82 ± 0.11 at all galactocentric radii from the core regions of the galaxy out to ∼40 kpc. This suggests that the size difference between blue and red GCs is due to internal mechanisms related to the evolution of their constituent stellar populations. Modeling the mass density profile of NGC 1399 shows that additional external dynamical mechanisms are required to limit the GC size in the galaxy halo regions to rh ≈ 2 pc. We suggest that this may be realized by an exotic GC orbit distribution function, an extended dark matter halo, and/or tidal stress induced by the increased stochasticity in the dwarf halo substructure at larger galactocentric distances. We compare our results with the GC rh distribution functions in various galaxies and find that the fraction of extended GCs with rh ≥ 5 pc is systematically larger in late-type galaxies compared with GC systems in early-type galaxies. This is likely due to the dynamically more violent evolution of early-type galaxies. We match our GC rh measurements with radial velocity data from the literature and split the resulting sample at the median rh value into compact and extended GCs. We find that compact GCs show a significantly smaller line-of-sight velocity dispersion, 〈σcmp〉 = 225 ± 25 km s-1, than their extended counterparts, 〈σ ext〉 = 317 ± 21 km s-1. Considering the weaker statistical correlation in the GC rh color and the GC r h-R gal relations, the more significant GC size-dynamics relation appears to be astrophysically more relevant and hints at the dominant influence of the GC orbit distribution function on the evolution of GC structural parameters. © 2014. The American Astronomical Society. All rights reserved.

Charging mechanism and moving reaction fronts in a supercapacitor with pseudocapacitance - Kadyka, T.; Eikerling, M. (Journal of the Electrochemical Society, 2014)
A model of a supercapacitor with pseudocapacitance focusing on effects along the thickness of the electrode was developed. Fast charging, i.e. high power density operation, was analyzed. The occurrence of moving reaction fronts under these conditions is found and discussed. Indicators of the occurrence of moving reaction fronts were defined by analyzing the reaction front velocity and deriving the reaction penetration depth. Effects of the moving reaction fronts on cyclic voltammograms were simulated and an asymmetric broadening of the oxidation peak was found. The influence of the moving reaction fronts on the performance of the supercapacitor was investigated by means of charging energy analysis. Losses were found mainly at the end of the oxidation phase. Partial charging under fast charging conditions reduces the losses. The scale-up of the electrode mass loading and thus the influence of the thickness was analyzed. Simulation results could be used as an "operation map" to avoid conditions with significant losses. © 2013 The Electrochemical Society. All rights reserved.
Keywords: Asymmetric broadening; Charging energies; Charging mechanism; Cyclic voltammograms; High power density; Moving reaction fronts; Pseudocapacitance; Super capacitor; Charging (batteries); Electric charge; Electrolytic capacitors; Loading

Global small-angle X-ray scattering data analysis for multilamellar vesicles: the evolution of the scattering density profile model - Heftberger, P.; Kollmitzer, B.; Heberle, F.A.; Pan, J.; Rappolt, M.; Amenitsch, H.; Kučerka, N.; Katsaras, J.; Pabst, G. (Journal of Applied Crystallography, 2014)
The highly successful scattering density profile (SDP) model, used to jointly analyze small-angle X-ray and neutron scattering data from unilamellar vesicles, has been adapted for use with data from fully hydrated, liquid crystalline multilamellar vesicles (MLVs). Using a genetic algorithm, this new method is capable of providing high-resolution structural information, as well as determining bilayer elastic bending fluctuations from standalone X-ray data. Structural parameters such as bilayer thickness and area per lipid were determined for a series of saturated and unsaturated lipids, as well as binary mixtures with cholesterol. The results are in good agreement with previously reported SDP data, which used both neutron and X-ray data. The inclusion of deuterated and non-deuterated MLV neutron data in the analysis improved the lipid backbone information but did not improve, within experimental error, the structural data regarding bilayer thickness and area per lipid. © 2014 International Union of Crystallography.
Keywords: Experimental errors; Multi-lamellar vesicles; Scattering density; Small angle X-ray scattering; Small-angle x-rays; Structural information; Structural parameter; Unilamellar vesicle; Binary mixtures; Crystalline materials; Deuterium; Genetic algorithms; Scattering; X ray scattering; X rays

Aquatic toxicity of manufactured nanomaterials: Challenges and recommendations for future toxicity testing - Schultz, A.G.; Boyle, D.; Chamot, D.; Ong, K.J.; Wilkinson, K.J.; McGeer, J.C.; Sunahara, G.; Goss, G.G. (Environmental Chemistry, 2014)
Environmental context The increased use of nanomaterials in industrial and consumer products requires robust strategies to identify risks when they are released into the environment. Aquatic toxicologists are beginning to possess a clearer understanding of the chemical and physical properties of nanomaterials in solution, and which of the properties potentially affect the health of aquatic organisms. This review highlights the main challenges encountered in aquatic nanotoxicity testing, provides recommendations for overcoming these challenges, and discusses recent studies that have advanced our understanding of the toxicity of three important OECD nanomaterials, titanium dioxide, zinc oxide and silver nanomaterials. Abstract Aquatic nanotoxicologists and ecotoxicologists have begun to identify the unique properties of the nanomaterials (NMs) that potentially affect the health of wildlife. In this review the scientific aims are to discuss the main challenges nanotoxicologists currently face in aquatic toxicity testing, including the transformations of NMs in aquatic test media (dissolution, aggregation and small molecule interactions), and modes of NM interference (optical interference, adsorption to assay components and generation of reactive oxygen species) on common toxicity assays. Three of the major OECD (Organisation for Economic Co-operation and Development) priority materials, titanium dioxide (TiO2), zinc oxide (ZnO) and silver (Ag) NMs, studied recently by the Natural Sciences and Engineering Research Council of Canada (NSERC), National Research Council of Canada (NRC) and the Business Development Bank of Canada (BDC) Nanotechnology Initiative (NNBNI), a Canadian consortium, have been identified to cause both bulk effect, dissolution-based (i.e. free metal), or NM-specific toxicity in aquatic organisms. TiO2 NMs are most toxic to algae, with toxicity being NM size-dependent and principally associated with binding of the materials to the organism. Conversely, dissolution of Zn and Ag NMs and the subsequent release of their ionic metal counterparts appear to represent the primary mode of toxicity to aquatic organisms for these NMs. In recent years, our understanding of the toxicological properties of these specific OECD relevant materials has increased significantly. Specifically, researchers have begun to alter their experimental design to identify the different behaviour of these materials as colloids and, by introducing appropriate controls and NM characterisation, aquatic nanotoxicologists are now beginning to possess a clearer understanding of the chemical and physical properties of these materials in solution, and how these materials may interact with organisms. Arming nanotoxicologists with this understanding, combined with knowledge of the physics, chemistry and biology of these materials is essential for maintaining the accuracy of all future toxicological assessments. © CSIRO 2014.

Ionization compression impact on dense gas distribution and star formation: Probability density functions around H II regions as seen by Herschel - Tremblin, P.; Schneider, N.; Minier, V.; Didelon, P.; Hill, T.; Anderson, L.D.; Motte, F.; Zavagno, A.; Andre, P.; Arzoumanian, D.; Audit, E.; Benedettini, M.; et al. (Astronomy and Astrophysics, 2014)
Aims. Ionization feedback should impact the probability distribution function (PDF) of the column density of cold dust around the ionized gas. We aim to quantify this effect and discuss its potential link to the core and initial mass function (CMF/IMF). Methods. We used Herschel column density maps of several regions observed within the HOBYS key program in a systematic way: M 16, the Rosette and Vela C molecular clouds, and the RCW 120 Hâ ‰ ii region. We computed the PDFs in concentric disks around the main ionizing sources, determined their properties, and discuss the effect of ionization pressure on the distribution of the column density. Results. We fitted the column density PDFs of all clouds with two lognormal distributions, since they present a "double-peak" or an enlarged shape in the PDF. Our interpretation is that the lowest part of the column density distribution describes the turbulent molecular gas, while the second peak corresponds to a compression zone induced by the expansion of the ionized gas into the turbulent molecular cloud. Such a double peak is not visible for all clouds associated with ionization fronts, but it depends on the relative importance of ionization pressure and turbulent ram pressure. A power-law tail is present for higher column densities, which are generally ascribed to the effect of gravity. The condensations at the edge of the ionized gas have a steep compressed radial profile, sometimes recognizable in the flattening of the power-law tail. This could lead to an unambiguous criterion that is able to disentangle triggered star formation from pre-existing star formation. Conclusions. In the context of the gravo-turbulent scenario for the origin of the CMF/IMF, the double-peaked or enlarged shape of the PDF may affect the formation of objects at both the low-mass and the high-mass ends of the CMF/IMF. In particular, a broader PDF is required by the gravo-turbulent scenario to fit the IMF properly with a reasonable initial Mach number for the molecular cloud. Since other physical processes (e.g., the equation of state and the variations among the core properties) have already been said to broaden the PDF, the relative importance of the different effects remains an open question. © 2014 ESO.
Keywords: C (programming language); Clouds; Distribution functions; Equations of state; Gases; Impact ionization; Ionization of gases; Probability distributions; Stars; Compression zones; Different effects; Equation of state; H II regions; ISM: structure; Log-normal distribution; Methods:observational; Stars: formation; Probability density function

Oxidation behaviour of gamma titanium aluminides with or without protective coatings - Kim, D.; Seo, D.; Huang, X.; Sawatzky, T.; Saari, H.; Hong, J.; Kim, Y.-W. (International Materials Reviews, 2014)
The γ-TiAl alloys are promising high temperature materials for aeroengines due to their low density, high specific strength and low material cost compared with Nickel based superalloys. However, the insufficient ductility at room temperature and the limited oxidation resistance at temperatures above approximately 750°C have limited their applications. Oxidation resistance in the application temperature range of 800 and 1000°C is of particular importance. Remarkable improvement to the environmental resistance by adding ternary and quaternary elements to the γ-TiAl alloys has been reported; however, alloying additions frequently deteriorate their mechanical properties. Surface modifications or coatings, which promote the formation of highly protective alumina scales, are also viable ways to improve the environmental resistance of TiAl alloys. In this article, the research work from the last 30 years on the oxidation behaviour of bare and coated TiAl alloys will be reviewed, with special focus on the γ-TiAl alloys. The review will begin with the oxidation behaviour of TiAl substrate alloys and the oxidation behaviour of γ-TiAl alloys with high temperature coatings such as aluminide, MCrAlY, Ti-Al-X and thermal barrier coating (TBC) system will be followed. © 2014 Institute of Materials, Minerals and Mining and ASM International Published by Maney for the Institute and ASM International.

Importance of π-stacking interactions in the hydrogen atom transfer reactions from activated phenols to short-lived N-oxyl radicals - Mazzonna, M.; Bietti, M.; Dilabio, G.A.; Lanzalunga, O.; Salamone, M. (Journal of Organic Chemistry, 2014)
A kinetic study of the hydrogen atom transfer from activated phenols (2,6-dimethyl- and 2,6-di-tert-butyl-4-substituted phenols, 2,2,5,7,8- pentamethylchroman-6-ol, caffeic acid, and (+)-cathechin) to a series of N-oxyl radical (4-substituted phthalimide-N-oxyl radicals (4-X-PINO), 6-substituted benzotriazole-N-oxyl radicals (6-Y-BTNO), 3-quinazolin-4-one-N-oxyl radical (QONO), and 3-benzotriazin-4-one-N-oxyl radical (BONO)), was carried out by laser flash photolysis in CH3CN. A significant effect of the N-oxyl radical structure on the hydrogen transfer rate constants (kH) was observed with kH values that monotonically increase with increasing NO-H bond dissociation energy (BDENO-H) of the N-hydroxylamines. The analysis of the kinetic data coupled to the results of theoretical calculations indicates that these reactions proceed by a hydrogen atom transfer (HAT) mechanism where the N-oxyl radical and the phenolic aromatic rings adopt a π-stacked arrangement. Theoretical calculations also showed pronounced structural effects of the N-oxyl radicals on the charge transfer occurring in the π-stacked conformation. Comparison of the kH values measured in this study with those previously reported for hydrogen atom transfer to the cumylperoxyl radical indicates that 6-CH3-BTNO is the best N-oxyl radical to be used as a model for evaluating the radical scavenging ability of phenolic antioxidants. © 2014 American Chemical Society.
Keywords: Atoms; Bond strength (chemical); Hydrogen; Isomers; Phenols; Rate constants; Bond dissociation energies; Hydrogen atom transfers (HAT); Hydrogen-atom transfer; Laser flash photolysis; Phenolic antioxidant; Phenolic aromatic rings; Stacking interaction; Theoretical calculations; Free radical reactions; 6 hydroxy 2,2,5,7,8 pentamethylchroman; acetonitrile; antioxidant; caffeic acid; catechin; hydrogen; hydroxylamine; n oxyl radical; phenol derivative; phthalimide; quinazoline derivative; radical; triazine derivative; unclassified drug; article; chemical binding; density functional theory; dissociation; energy; enthalpy; gas; hydrogen bond; proton transport; solvent effect; time

The oxygen index on soot production in propane diffusion flames - Henríquez, R.; Demarco, R.; Consalvi, J.L.; Liu, F.; Fuentes, A. (Combustion Science and Technology, 2014)
An experimental study of the effect of oxygen index (OI) on soot formation in laminar coflow propane diffusion flames is presented. The OI was defined as the oxygen volumetric concentration in the oxidizer flow, O2/(O 2+N2), which was varied from 21% to 37%. The influence of the OI was quantified by means of three variables: the flame height, the soot volume fraction, and the vertical distribution of radiative heat flux. The flame height was based on CH* spontaneous emission and found to vary inversely with the OI, following the classical theory of Roper. As the OI increases, the rates of soot growth and soot oxidation are enhanced, and the maximum soot volume fraction and the peak of integrated soot volume fraction also increase. Moreover, the evolution of the peak of radiative heat flux and the maximum soot volume fraction are found to follow the same evolution with the OI. Copyright © Taylor & Francis Group, LLC.
Keywords: Diffusion; Heat flux; Oxygen; Propane; Soot; Volume fraction; Classical theory; Diffusion Flame; Effect of oxygen; Radiative heat fluxes; Soot formations; Soot volume fraction; Vertical distributions; Volumetric concentrations; Dust

Insights into the behavior of biological clathrate hydrate inhibitors in aqueous saline solutions - Sharifi, H.; Walker, V.K.; Ripmeester, J.; Englezos, P. (Crystal Growth and Design, 2014)
The performance of two antifreeze proteins (AFPs), type I and III (AFP I and III), as kinetic natural gas hydrate inhibitors in saline solutions was evaluated using a high pressure micro differential scanning calorimeter and a high pressure apparatus consisting of two crystallizers. Although AFP I and III were found to prolong crystallization time and reduce initial gas hydrate growth in saline solutions, the growth rate increased when hydrate started to form in the gas phase. Circular dichroism experiments suggested that the saline solution did not perturb AFP I and III structures. However, in the presence of saline, the inhibitory activity of AFP I to prolong induction time decreased while AFP III was more active. As a consequence, we propose that a decrease in hydrophobic forces and the neutralization of ion charges could explain AFP adsorption to the surface of hydrate crystals. Once the hydrate formed, melting was delayed, and consequently hydrate decomposition took longer in the presence of AFPs. We suggest conditions whereby the properties of AFPs could be harnessed for petrochemical recovery and transport. © 2014 American Chemical Society.
Keywords: Differential scanning calorimetry; Hydration; Antifreeze protein; Clathrate hydrate; Crystallization time; Differential scanning calorimeters; High pressure apparatus; Hydrate decomposition; Hydrophobic forces; Inhibitory activity; Gas hydrates

Applications of in situ Raman spectroscopy for identifying nickel hydroxide materials and surface layers during chemical aging - Hall, David S.; Lockwood, David J.; Poirier, Shawn; Bock, Christina; MacDougall, Barry R. (ACS Applied Materials and Interfaces, 2014)
The applications of in situ vibrational spectroscopy for identifying bulk and surface Ni(OH)2 are discussed. Raman spectra from α- and β-Ni(OH)2 samples immersed in water are generally similar to those collected from comparable dry samples. However, the Raman scattering intensities vary, and dry β-Ni(OH)2 additionally exhibits a surface O-H stretching mode at 3690 cm-1. Using in situ Raman spectroscopy, the spontaneous transformation of α-Ni(OH)2 to β-Ni(OH)2 in room-temperature water was monitored. Such transformations are conventionally performed in high-temperature alkaline media. An intralayer OH-diffusion model is proposed. Internal stresses at the α/β-phase boundary caused shifted peaks, higher order vibrational modes, and a new water peak at 3520 cm-1. We conclude that Raman spectroscopy may be applied to observe Ni(OH)2 materials in situ during chemical and electrochemical treatments. Such measurements provide information on the proportions of α- and β-Ni(OH)2 and their fine structural details with high sensitivity. © Published 2014 by the American Chemical Society.
Keywords: Alkalinity; Raman scattering; Raman spectroscopy; Surfaces; Vibrational spectroscopy; Electrochemical treatments; In-situ Raman spectroscopy; Nickel hydroxides; Raman scattering intensity; Spontaneous transformation; Stretching modes; Structural details; Vibrational modes; Nickel

A preliminary ventilation rate determination methods study for residential buildings and offices based on VOC emission database - Ye, W.; Won, D.; Zhang, X. (Building and Environment, 2014)
Ventilation is commonly used as a basic means to supply outdoor air to indoor environment to achieve better indoor air quality. To reduce harmful effect due to indoor pollutants such as formaldehyde and VOCs emitted from building materials, proper ventilation should be maintained to meet a minimum ventilation rate at least. Two new methods, i.e., characteristic and two-stage ventilation rate method, were proposed to predict ventilation rate based on building material emissions. Scenarios involving four standard rooms and different material loadings were analyzed to study adequate ventilation rates for residential buildings and offices. The study followed the IAQ procedure recommended by ASHRAE. The emission source data were from the National Research Council Canada (NRC) database. The building material emissions and consequent VOC concentrations were predicted by using two approaches called the characteristic emission rate method and the two-stage emission rate method. The ventilation rates were calculated for ten scenarios to meet the thresholds given by seven indoor air quality references. The results showed that the ventilation rate depended on the selection of reference standard, material and emission area. The dominating chemical substance in determining ventilation rate in various cases was not unique. The time to take for the emission to complete was 2.5-5 years for all cases. Due to the inherent nature of the characteristic emission rate method for over-estimating long-term emissions, replacing the characteristic ventilation rate with steady-state ventilation rate could lead to the ventilation rate requirement reduced by approximately half. © 2014 Elsevier Ltd.
Keywords: Building codes; Building materials; Buildings; Indoor air pollution; ACH; Characteristic emission; Determination methods; Indoor environment; LCI; Material emissions; National Research Council; Residential building; Ventilation; air quality; building; construction material; emission; indoor air; ventilation; volatile organic compound

Inter-cage dynamics in structure I, II, and H fluoromethane hydrates as studied by NMR and molecular dynamics simulations - Trueba, A.T.; Kroon, M.C.; Peters, C.J.; Moudrakovski, I.L.; Ratcliffe, C.I.; Alavi, S.; Ripmeester, J.A. (Journal of Chemical Physics, 2014)
Prospective industrial applications of clathrate hydrates as materials for gas separation require further knowledge of cavity distortion, cavity selectivity, and defects induction by guest-host interactions. The results presented in this contribution show that under certain temperature conditions the guest combination of CH3F and a large polar molecule induces defects on the clathrate hydrate framework that allow intercage guest dynamics. 13C NMR chemical shifts of a CH3F/CH4/TBME sH hydrate and a temperature analysis of the 2H NMR powder lineshapes of a CD3F/THF sII and CD3F/TBME sH hydrate, displayed evidence that the populations of CH4 and CH3F in the D and D′ cages were in a state of rapid exchange. A hydrogen bonding analysis using molecular dynamics simulations on the TBME/CH3F and TBME/CH4 sH hydrates showed that the presence of CH3F enhances the hydrogen bonding probability of the TBME molecule with the water molecules of the cavity. Similar results were obtained for THF/CH3F and THF/CH4 sII hydrates. The enhanced hydrogen bond formation leads to the formation of defects in the water hydrogen bonding lattice and this can enhance the migration of CH3F molecules between adjacent small cages. © 2014 AIP Publishing LLC.
Keywords: Defects; Hydration; Hydrogen bonds; Industrial applications; Molecular dynamics; Molecules; Nuclear magnetic resonance spectroscopy; Clathrate hydrate; Gas separations; Guest-host interactions; Hydrogen-bond formation; Molecular dynamics simulations; NMR chemical shifts; Temperature analysis; Temperature conditions; Gas hydrates

Computational study of the effect of dispersion interactions on the thermochemistry of aggregation of fused polycyclic aromatic hydrocarbons as model asphaltene compounds in solution - Moreira Da Costa, L.; Stoyanov, S.R.; Gusarov, S.; Seidl, P.R.; Walkimar De M. Carneiro, J.; Kovalenko, A. (The Journal of Physical Chemistry A, 2014)
Density functional theory (DFT), Møller-Plesset second-order perturbation theory (MP2), and semiempirical methods are employed for the geometry optimization and thermochemistry analysis of π-π stacked di-, tri-, tetra-, and pentamer aggregates of the fused polycyclic aromatic hydrocarbons (PAHs) naphthalene, anthracene, phenanthrene, tetracene, pyrene, and coronene as well as benzene. These aggregates (stabilized by dispersion interactions) are highly relevant to the intermolecular aggregation of asphaltenes, major components of heavy petroleum. The strength of π-π stacking interaction is evaluated with respect to the π-stacking distance and thermochemistry results, such as aggregation enthalpies, entropies, and Gibbs free energies (ΔG298). For both π-stacking interplanar distances and thermochemistry, the ωB97X-D functional with an augmented damped R-6 dispersion correction term and MP2 are in the closest agreement with the highly accurate spin-component scaled MP2 (SCS-MP2) method that we selected as a reference. The ΔG298 values indicate that the aggregation of coronene is spontaneous at 298 K and the formation of pyrene dimers occurs spontaneously at temperature lower than 250 K. Aggregates of smaller PAHs would be stable at even lower temperature. These findings are supported by X-ray crystallographic determination results showing that among the PAHs studied only coronene forms continuous stacked aggregates in single crystals, pyrene forms dimers, and smaller PAHs do not form π-π stacked aggregates. Thermochemistry analysis results show that PAHs containing more than four fused benzene rings would spontaneously form aggregates at 298 K. Also, round-shaped PAHs, such as phenanthrene and pyrene, form more stable aggregates than linear PAHs, such as anthracene and tetracene, due to decreased entropic penalty. These results are intended to help guide the synthesis of model asphaltene compounds for spectroscopic studies so as to help understand the aggregation behavior of heavy petroleum. © 2014 American Chemical Society.
Keywords: Computational studies; Dispersion interaction; Intermolecular aggregation; Polycyclic aromatic hydrocarbons (PAHS); Second order perturbation theory; Semi-empirical methods; Spectroscopic studies; Thermochemistry analysis; Anthracene; Asphaltenes; Benzene; Electromagnetic dispersion; Naphthalene; Pyrene; Spectroscopic analysis; Thermochemistry; X ray crystallography; Aggregates

Zircon mineral solids concentrated from Athabasca oil sands froth treatment tailings: Surface chemistry and flotation properties - Marshall, G.M.; Patarachao, B.; Moran, K.; Mercier, P.H.J. (Minerals Engineering, 2014)
Zircon mineral solids concentrated from Athabasca oil sands froth treatment tailings were compared by X-ray photoelectron spectroscopy, infrared spectroscopy, and collector-assisted froth flotation before and after surface cleaning in a low temperature, radio-frequency oxygen plasma. Plasma cleaning was effective at removing a surface bound layer of organic matter having chemical markers consistent with bituminous fractions. Specifically, the observation of long-chain aliphatics, ester and ether linkages, aromatic indicators, and hydroxyls in the absence of carboxylic acid groups, suggested the surface organic layer was representative of asphaltene or resin. Supporting this interpretation was the identification of pyrrolic and thiophenic chemical states. Plasma degradation of the hydrocarbon component transformed the zircon particles from hydrophobic to hydrophilic as evidenced by their recovery in water/ethanol froth flotation tests. The cleaned zircon particles were subsequently collected in the froth using dodecylamine. This work explains the surface conditions responsible for the reporting of zircon to the froth treatment tailings and demonstrates the efficacy of plasma cleaning as a means to condition zircon for coupling with collector agents. A physical model of surface adsorption is discussed and process implications are considered. © 2014 Published by Elsevier Ltd.
Keywords: Chemical cleaning; Infrared spectroscopy; Oil sands; Plasma applications; Plasmas; Surface chemistry; X ray photoelectron spectroscopy; Zircon; Athabasca oil sands; Carboxylic acid groups; Hydrocarbon components; Plasma degradation; Plasma treatment; Surface adsorption; Surface conditions; Surface organic layers; Froth flotation

A regenerating self-assembled gold nanoparticle-containing electrochemical impedance sensor - Mahmoud, A.M.; Tang, T.; Jed Harrison, D.; Lee, W.E.; Jemere, A.B. (Biosensors and Bioelectronics, 2014)
We report on the development of an electrochemical reductive desorption protocol for repeated regeneration of gold electrodes modified with multi-layers of self-assembled surfaces for use in electrochemical sensing. The gold electrodes were first modified with 1,6-hexanedithiol to which gold nanoparticles were attached in a subsequent modification step. Attachment of thiolated single-stranded nucleic acid oligomers to the gold nanoparticles completed the electrochemical sensor. The changes of electrode behavior after each assembly and desorption processes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques. The self-assembled sensor showed a wide dynamic range (0.1-100. nM), a low detection limit (20. pM) and high reproducibility (4.4% RSD) for complementary nucleic acid target molecules, along with reusability. On a single gold electrode, the complete sensor-target structure could be assembled and disassembled at least four times with 90% of its original signal intact. © 2014 Elsevier B.V.

Enrichment of large-diameter semiconducting SWCNTs by polyfluorene extraction for high network density thin film transistors - Ding, J.; Li, Z.; Lefebvre, J.; Cheng, F.; Dubey, G.; Zou, S.; Finnie, P.; Hrdina, A.; Scoles, L.; Lopinski, G.P.; Kingston, C.T.; Simard, B.; et al. (Nanoscale, 2014)
A systematic study on the use of 9,9-dialkylfluorene homopolymers (PFs) for large-diameter semiconducting (sc-) single-walled carbon nanotube (SWCNT) enrichment is the focus of this report. The enrichment is based on a simple three-step extraction process: (1) dispersion of as-produced SWCNTs in a PF solution; (2) centrifugation at a low speed to separate the enriched sc-tubes; (3) filtration to collect the enriched sc-SWCNTs and remove excess polymer. The effect of the extraction conditions on the purity and yield including molecular weight and alkyl side-chain length of the polymers, SWCNT concentration, and polymer/SWCNT ratio have been examined. It was observed that PFs with alkyl chain lengths of C10, C12, C14, and C18, all have an excellent capability to enrich laser-ablation sc-SWCNTs when their molecular weight is larger than ∼10 000 Da. More detailed studies were therefore carried out with the C12 polymer, poly(9,9-di-n-dodecylfluorene), PFDD. It was found that a high polymer/SWCNT ratio leads to an enhanced yield but a reduced sc-purity. A ratio of 0.5-1.0 gives an excellent sc-purity and a yield of 5-10% in a single extraction as assessed by UV-vis-NIR absorption spectra. The yield can also be promoted by multiple extractions while maintaining high sc-purity. Mechanistic experiments involving time-lapse dispersion studies reveal that m-SWCNTs have a lower propensity to be dispersed, yielding a sc-SWCNT enriched material in the supernatant. Dispersion stability studies with partially enriched sc-SWCNT material further reveal that m-SWCNTs : PFDD complexes will re-aggregate faster than sc-SWCNTs : PFDD complexes, providing further sc-SWCNT enrichment. This result confirms that the enrichment was due to the much tighter bundles in raw materials and the more rapid bundling in dispersion of the m-SWCNTs. The sc-purity is also confirmed by Raman spectroscopy and photoluminescence excitation (PLE) mapping. The latter shows that the enriched sc-SWCNT sample has a narrow chirality and diameter distribution dominated by the (10,9) species with d = 1.29 nm. The enriched sc-SWCNTs allow a simple drop-casting method to form a dense nanotube network on SiO2/Si substrates, leading to thin film transistors (TFTs) with an average mobility of 27 cm2 V -1 s-1 and an average on/off current ratio of 1.8 × 106 when considering all 25 devices having 25 μm channel length prepared on a single chip. The results presented herein demonstrate how an easily scalable technique provides large-diameter sc-SWCNTs with high purity, further enabling the best TFT performance reported to date for conjugated polymer enriched sc-SWCNTs. © 2014 The Royal Society of Chemistry.
Keywords: Alkyl side-chain lengths; Diameter distributions; Extraction conditions; Photoluminescence excitation; Semiconducting-SWCNTs; Singlewalled carbon nanotube (SWCNT); Thin-film transistor (TFTs); UV-Vis-NIR absorption; Chain length; Complex networks; Extraction; Molecular weight; Single-walled carbon nanotubes (SWCN); Thin film transistors; Thin films; Dispersions

Gafchromic® film dosimetry for low energy X radiation - Mehta, K.; Parker, A.; Tessier, F. (Radiation Measurements, 2014)
Recent developments have produced low energy X ray systems capable of providing a radiation dose to adequate volumes suitable for sterile inset programmes. To support the adoption of these new systems, the performance of the Gafchromic® HD-810 dosimetry system previously used for gamma irradiation needed to be better understood at the lower photon energies. For low energy photons, the optical density of the irradiated Gafchromic HD-810 film dosimeters significantly depends on the material surrounding them. For example, if paper, Mylar® or PVC is used to house the dosimeter during irradiation, the optical density can vary by as much as a factor of three or more for the same dose. This paper is an attempt to elucidate the performance of the Gafchromic HD-810 film dosimeters for such low energy X radiation (∼150 keV). Our data show that this behaviour can be explained by the fact that these materials have significantly different photon mass attenuation coefficient. This conclusion was reinforced with mathematical simulation using Monte Carlo modelling. We also show that with the different structure of another Gafchromic film dosimeter (MD-V2-55) this effect is virtually non-existent. An understanding of the behaviour of thin film dosimeters like Gafchromic HD-810 under radiation is crucial for reliable dosimetry. We hope that this work can also provide guidance in the use of other thin film dosimeters at similar low photon energies. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Density (optical); Density measurement (optical); Dosimetry; Photons; Polyvinyl chlorides; Thin films; Different structure; Electron equilibrium; Low energy photons; Mass attenuation coefficients; Mathematical simulations; Monte Carlo modelling; RS-2400; Thin film dosimeters; Dosimeters

Flow visualization and characterization for optimized MQL machining of composites - Iskandar, Y.; Tendolkar, A.; Attia, M.H.; Hendrick, P.; Damir, A.; Diakodimitris, C. (CIRP Annals - Manufacturing Technology, 2014)
Limited information is available on the effect of Minimum Quantity Lubrication (MQL) parameters (oil flow rate OFR, air flow rate AFR, nozzle orientation and distance from the cutting zone) on flow characteristics. 'Particle Image Velocimetry' and 'Phase Doppler Anemometry' flow visualization methods were used to define the optimal MQL jet for better penetration and cooling/lubrication; coherent, small magnitude/number of vorticities, and small droplets of high velocity. Effect of flow characteristics on cutting forces, temperature, tool wear and geometric errors was examined in CFRP milling. Optimum AFR, OFR and nozzle distance from the cutting zone were established and compared to flood, pressurized air, and dry machining. © 2014 CIRP.
Keywords: Composite materials; Cutting; Drop formation; Flow rate; Nozzles; Flow charac-teristics; Geometric errors; Limited information; Minimum quantity lubrication; Nozzle orientations; Particle image velocimetries; Phase Doppler anemometry; Visualization method; Flow visualization

Structural basis for selective cross-reactivity in a bactericidal antibody against inner core lipooligosaccharide from Neisseria meningitidis - Parker, M.J.; Gomery, K.; Richard, G.; Mackenzie, C.R.; Cox, A.D.; Richards, J.C.; Evans, S.V. (Glycobiology, 2014)
The structure of a antigen-binding fragment (Fab) from the bactericidal monoclonal antibody LPT3-1 specific to lipooligosaccharide (LOS) inner cores from Neisseria meningitidis has been solved in complex with an eight-sugar inner core fragment NmL3 galE lpt3 KOH to 2.69 Å resolution. The epitope is centered about an inner core N-acetylglucosamine residue unique to N. meningitidis and does not include the lipid A moiety, which is disordered in the structure, but is positioned to allow the binding of free and membrane-anchored full-length LOS. All the amino acid residues that contact antigen are of germline origin but, remarkably, two consecutive somatic mutations of serine to glycine in the heavy chain at residues 52 and 52a are positioned to deprive the antibody of advantageous interactions and so weaken binding. However, these mutations are key to allowing selective cross-reactivity with the HepII-3-PEtn inner core variant expressed by 70% of strains. Neisseria meningitidis is a leading cause of disease in the developed world and is especially dangerous to children, who lack the necessary protective antibodies. The structure of Fab LPT3-1 in complex with LOS provides insight into the antibody's selective ability to recognize multiple clinically relevant variations of the LOS inner core from N. meningitidis. © The Author 2014.
Keywords: amino acid; bacterium antibody; glycine; lipid A; lipooligosaccharide; monoclonal antibody; monoclonal antibody LPT3 1; n acetylglucosamine; serine; unclassified drug; antigen recognition; article; bacterial strain; controlled study; cross reaction; drug structure; heavy chain; Neisseria meningitidis; nonhuman; priority journal; somatic mutation; structure analysis; X ray crystallography

Development of robust control law for active buffeting load alleviation of smart fin structures - Chen, Y.; Ulker, F.D.; Wickramasinghe, V.; Zimcik, D.G. (Journal of Intelligent Material Systems and Structures, 2014)
Aerodynamic buffeting load can lead to premature fatigue damage of aircraft vertical fin structures. This article presents a robust control law development strategy for active buffeting load alleviation of a smart fin structure. The impact of aerodynamic loads on the modeling uncertainties of the smart fin was investigated through extensive wind tunnel tests. Test results revealed that the airflow introduced higher damping ratio and caused frequency shift to the vibration modes. These aerodynamic effects may adversely affect the performance and robustness of active control laws. Based on the observations, the structured singular value synthesis technique was used to develop a robust control law for the smart fin using a truncated baseline dynamic model. A parametric uncertainty block was introduced to account for the changes in the modal parameters of the baseline dynamic model due to the aerodynamic effects. An additive uncertainty block was included to account for the unmodeled higher-order vibration modes as well as the modeling errors in the low frequency range. The robust performance of the control law was demonstrated through simulations as well as extensive closed-loop control experiments in the wind tunnel using various free airstreams and vortical airflows. This provided a verified control law design strategy for active buffeting alleviation applications. © The Author(s) 2013.

Synthesis of high quality single-walled carbon nanotubes with purity enhancement and diameter control by liquid precursor Ar-H2 plasma spraying - Kim, K.S.; Kingston, C.T.; Ruth, D.; Barnes, M.; Simard, B. (Chemical Engineering Journal, 2014)
As usage of carbon nanotubes continues to increase in both scientific research and practical applications, there has been a growing interest in the large-scale synthesis of those materials with high quality and high purity. Here we report a new plasma process developed for the large-scale synthesis of high quality single-walled carbon nanotubes (SWCNTs). An induction thermal plasma with a liquid precursor spraying technique was employed for an effective synthesis of SWCNTs from a mixture of toluene and ferrocene. It has been successfully demonstrated in this new process that high quality SWCNTs can be synthesized continuously with a reasonably high-purity, the structural quality of the materials produced being comparable to those of SWCNTs produced from the laser vaporization process. The high temperature of the plasma, over 4000. K, seems to be responsible for the production of high quality SWCNTs and the rapid treatment of a large amount of feedstock, whereas the hydrogen plasma contributes to the purity enhancement by selective etching of amorphous carbon. It is also found that the diameter distribution of SWCNTs can be controlled effectively by varying the sulfur content in the feedstock mixture, which is very promising for many advanced applications of SWCNTs such as SWCNT-based electronics. © 2014.
Keywords: Amorphous carbon; Feedstocks; Liquids; Mixtures; Organometallics; Plasma spraying; Plasmas; Single-walled carbon nanotubes (SWCN); Thermal spraying; Diameter control; Diameter distributions; Induction plasma; Induction thermal plasma; Large scale synthesis; Liquid precursors; Scientific researches; Single-walled carbon nanotube (SWCNTs); Process control

Mineralization of the connective tissue: A complex molecular process leading to age-related loss of function - Shindyapina, A.V.; Mkrtchyan, G.V.; Gneteeva, T.; Buiucli, S.; Tancowny, B.; Kulka, M.; Aliper, A.; Zhavoronkov, A. (Rejuvenation Research, 2014)
Age-related metastatic mineralization of soft tissues has been considered a passive and spontaneous process. Recent data have demonstrated that calcium salt deposition in soft tissues could be a highly regulated process. Although calcification occurs in any tissue type, vascular calcification has been of particular interest due to association with atherosclerosis, chronic kidney disease (CKD), and osteoporosis. Different mechanisms underlying calcium apatite accumulation are explored with these age-related disorders. In the case of atherosclerotic plaques, oxy-lipids trigger release of the pro-inflammatory cytokines and inflammation that activate calcification processes in aorta intimae. In CKD patients, renal failure alters the balance between calcium and phosphate levels usually regulated by fibroblast growth factor-23 (FGF23), Klotho, and vitamin D, and vascular smooth muscle cells (VSMCs) begin to explore an osteoblastosteoblast-like phenotype. Calcification could affect extracellular matrix along with VSMCs. Collagen is a major component of extracellular matrix and its modifications accumulate with age. The formation of cross-links between collagen fibers is regulated by the action of lysine hydroxylases and lysyl oxidase and could occur spontaneously. Oxidation-induced advanced glycation end products (AGEs) are a major type of spontaneous cross-links that accelerate with age and may result in tissue stiffness, problems with recycling, and potential accumulation of calcium apatite. Applying strategies for clearing the AGEs proposed by de Grey may be more difficult in the highly mineralized extracellular matrix. We performed bioinformatic analysis of the molecular pathways underlying calcification in atherosclerotic and CKD patients, signaling pathways of collagen cross-links formation, and bone mineralization, and we propose new potential targets and review drugs for calcification treatment. © Copyright 2014, Mary Ann Liebert, Inc. 2014.
Keywords: advanced glycation end product; bone morphogenetic protein; collagen; fibroblast growth factor; fresolimumab; hydroxymethylglutaryl coenzyme A reductase inhibitor; matrix metalloproteinase inhibitor; metelimumab; pioglitazone; procollagen lysine 2 oxoglutarate 5 dioxygenase; protein lysine 6 oxidase; age; aging; article; atherosclerosis; bioinformatics; blood vessel calcification; bone disease; bone mineralization; chronic kidney disease; connective tissue; craniofacial synostosis; cross linking; hormone substitution; human; kidney polycystic disease; nonhuman; nuclear magnetic resonance imaging; optical coherence tomography; ossification; priority journal; protein cross linking; pseudoxanthoma elasticum; rigidity; soft tissue calcification; tissue degeneration; tissue mineralization

Epimers of azaspiracids: Isolation, structural elucidation, relative LC-MS response, and in vitro toxicity of 37-epi-azaspiracid-1 - Kilcoyne, J.; McCarron, P.; Twiner, M.J.; Nulty, C.; Crain, S.; Quilliam, M.A.; Rise, F.; Wilkins, A.L.; Miles, C.O. (Chemical Research in Toxicology, 2014)
Since azaspiracid-1 (AZA1) was identified in 1998, the number of AZA analogues has increased to over 30. The development of an LC-MS method using a neutral mobile phase led to the discovery of isomers of AZA1, AZA2, and AZA3, present at ∼2-16% of the parent analogues in phytoplankton and shellfish samples. Under acidic mobile phase conditions, isomers and their parents are not separated. Stability studies showed that these isomers were spontaneous epimerization products whose formation is accelerated with the application of heat. The AZA1 isomer was isolated from contaminated shellfish and identified as 37-epi-AZA1 by nuclear magnetic resonance (NMR) spectroscopy and chemical analyses. Similar analysis indicated that the isomers of AZA2 and AZA3 corresponded to 37-epi-AZA2 and 37-epi-AZA3, respectively. The 37-epimers were found to exist in equilibrium with the parent compounds in solution. 37-epi-AZA1 was quantitated by NMR, and relative molar response studies were performed to determine the potential differences in LC-MS response of AZA1 and 37-epi-AZA1. Toxicological effects were determined using Jurkat T lymphocyte cells as an in vitro cell model. Cytotoxicity experiments employing a metabolically based dye (i.e., MTS) indicated that 37-epi-AZA1 elicited a lethal response that was both concentration- and time-dependent, with EC50 values in the subnanomolar range. On the basis of EC50 comparisons, 37-epi-AZA1 was 5.1-fold more potent than AZA1. This data suggests that the presence of these epimers in seafood products should be considered in the analysis of AZAs for regulatory purposes. © 2014 American Chemical Society.
Keywords: 37 epiazaspiracid 1; acetonitrile; azaspiracid; dye; unclassified drug; aqueous solution; article; carbon nuclear magnetic resonance; concentration response; consumer; controlled study; cytotoxicity; cytotoxicity assay; decarboxylation; epimer; epimerization; experimental model; food contamination; half life time; in vitro study; leukemia cell line; liquid chromatography; mass spectrometry; mussel; phytoplankton; proton nuclear magnetic resonance; reaction analysis; sea food; shellfish; structure analysis; tandem mass spectrometry; time; toxicity testing; toxin analysis

An immunogenic peptide in the A-box of HMGB1 protein reverses apoptosis-induced tolerance through RAGE receptor - LeBlanc, P.M.; Doggett, T.A.; Choi, J.; Hancock, M.A.; Durocher, Y.; Frank, F.; Nagar, B.; Ferguson, T.A.; Saleh, M. (Journal of Biological Chemistry, 2014)
Apoptotic cells trigger immune tolerance in engulfing phagocytes. This poorly understood process is believed to contribute to the severe immunosuppression and increased susceptibility to nosocomial infections observed in critically ill sepsis patients. Extracellular high mobility group box 1 (HMGB1) is an important mediator of both sepsis lethality and the induction of immune tolerance by apoptotic cells. We have found that HMGB1 is sensitive to processing by caspase-1, resulting in the production of a fragment within its N-terminal DNA-binding domain (the A-box) that signals through the receptor for advanced glycation end products (RAGE) to reverse apoptosis-induced tolerance. In a two-hit mouse model of sepsis, we show that tolerance to a secondary infection and its associated mortality were effectively reversed by active immunization with dendritic cells treated with HMGB1 or the Abox fragment, but not a noncleavable form of HMGB1. These findings represent a novel link between caspase-1 and HMGB1, with potential therapeutic implications in infectious and inflammatory diseases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
Keywords: Biochemistry; Biology; Advanced glycation end products; Apoptotic cells; Critically ills; DNA-binding domain; High-mobility groups; Immune tolerances; Inflammatory disease; Nosocomial infection; Cell death; advanced glycation end product; advanced glycation end product receptor; aspartic acid; cryopyrin; dendritic cell vaccine; high mobility group B1 protein; inflammasome; interleukin 1beta converting enzyme; recombinant enzyme; A box; active immunization; amino terminal sequence; animal cell; animal experiment; animal model; animal tissue; apoptosis; article; candidemia; cell therapy; delayed hypersensitivity; dendritic cell; DNA binding motif; embryo; immunogenicity; immunological tolerance; immunomodulation; in vitro study; mortality; mouse; nonhuman; priority journal; protein domain; protein protein interaction; secondary infection; sepsis; Apoptosis; Caspase; Inflammation; Innate Immunity; Receptor for Advanced Glycation End Products (RAGE); Sepsis; Tolerance; Animals; Apoptosis; Candida; Candidiasis; Caspase 1; Dendritic Cells; Fibroblasts; HMGB1 Protein; Immune Tolerance; Immunity, Innate; Inflammation; Mice; Mice, Inbred C57BL; Mice, Knockout; Peptides; Receptors, Immunologic; Recombinant Proteins; Sepsis; Surface Plasmon Resonance

Superhydrophobic stability of nanotube array surfaces under impact and static forces - Zhu, L.; Shi, P.; Xue, J.; Wang, Y.; Chen, Q.; Ding, J.; Wang, Q. (ACS Applied Materials and Interfaces, 2014)
The surfaces of nanotube arrays were coated with poly(methyl methacrylate) (PMMA) using an imprinting method with an anodized alumina membrane as the template. The prepared nanotube array surfaces then either remained untreated or were coated with NH2(CH2)3Si(OCH 3)3(PDNS) or CF3(CF2) 7CH2CH2Si(OC2H5) 3 (PFO). Thus, nanotube arrays with three different surfaces, PDNS, PMMA (without coating), and PFO, were obtained. All three surfaces (PDNS, PMMA, and PFO) exhibited superhydrophobic properties with contact angles (CA) of 155, 166, and 168°, respectively, and their intrinsic water contact angles were 30, 79, and 118°, respectively. The superhydrophobic stabilities of these three surfaces were examined under dynamic impact and static pressures in terms of the transition from the Cassie-Baxter mode to the Wenzel mode. This transition was determined by the maximum pressure (pmax), which is dependent on the intrinsic contact angle and the nanotube density of the surface. A pmax greater than 10 kPa, which is sufficiently large to maintain stable superhydrophobicity under extreme weather conditions, such as in heavy rain, was expected from the PFO surface. Interestingly, the PDNS surface, with an intrinsic CA of only 30°, also displayed superhydrophobicity, with a CA of 155°. This property was partially maintained under the dynamic impact and static pressure tests. However, under an extremely high pressure (0.5 MPa), all three surfaces transitioned from the Cassie-Baxter mode to the Wenzel mode. Furthermore, the lost superhydrophobicity could not be recovered by simply relieving the pressure. This result indicates that the best way to maintain superhydrophobicity is to increase the pmax of the surface to a value higher than the applied external pressure by using low surface energy materials and having high-density binary nano-/microstructures on the surface. © 2014 American Chemical Society.
Keywords: Alumina; Contact angle; Energy barriers; Esters; Nanotubes; Silicon; Anodized alumina membranes; External pressures; Extreme weather conditions; Low surface energy materials; Nanotube arrays; Poly(methyl methacrylate) (PMMA); State transitions; Superhydrophobic; Hydrophobicity

Erythorbic acid promoted synthesis of CdS quantum dots in aqueous solution and study on optical properties - Liang, Y.; Yu, K.; Wang, J.; Chen, J.; Sun, B.; Shao, L. (Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014)
The effect of erythorbic acid (EA) on the aqueous formation of CdS quantum dots (QDs) at room temperature was explored in this work. Without N2 protection, CdS QDs were synthesized in water by a one-pot non-hot-injection approach at room temperature. The Cd and S sources were CdCl2 and Na2S, respectively, together with 3-mercapto-propionic acid (MPA) as the passivating ligand. The experimental results indicate that the use of the oxygen scavenger, i.e., EA, was critical for the formation of the CdS QDs with reasonably good optical properties, and it is also important to tune experimental parameters such as MPA-to-Cd molar ratios, pH, and reactant concentrations. The mechanism about the EA promoted formation of CdS QDs was discussed in terms of NMR, IR, in situ absorption, and photoemission studies. The very reason for the EA promoted formation of CdS QDs is due to its reducibility and passivation on the QD surface (particularly in alkaline environment). The present study suggests that the use of EA could be a practical means to enable the room-temperature formation of QDs in water. © 2014 Elsevier B.V.
Keywords: Alkalinity; Cadmium chloride; Optical properties; Passivation; Scavenging; Semiconductor quantum dots; Water injection; Acid-promoted synthesis; Cds quantum dots(QDs); Environment friendly; Experimental parameters; Oxygen scavengers; QDs; Reactant concentrations; Water-soluble; Cadmium sulfide; 3 mercaptopropionic acid; cadmium sulfate; isoascorbic acid; quantum dot; absorption; aqueous solution; article; chemical structure; infrared spectrometry; nuclear magnetic resonance; priority journal; room temperature; synthesis

Electrochemical performance of gadolinia-doped ceria (CGO) electrolyte thin films for ITSOFC deposited by spray pyrolysis - Reolon, R.P.; Halmenschlager, C.M.; Neagu, R.; De Fraga Malfatti, C.; Bergmann, C.P. (Journal of Power Sources, 2014)
Solid Oxide Fuel Cell is an attractive, efficient, alternative source of power generation. However several challenges remained for this technology to be viable. These challenges include high power density, degradation rate, and cost. One way to decrease the SOFC cost is to use stainless steel interconnector. To be able to use a stainless steel interconnector one of the challenges is to find a way to produce an electrolyte, which does not need sintering at high temperature. This work presents the results of the process applied to gadolinia-doped ceria thin films deposited in cycles by spray pyrolysis. The aim of this work was to obtain thin, dense, and continuous CGO coatings, which has electrochemical performance suitable to be used as electrolyte for SOFC. The results obtained show that the air flow rate influenced the droplets size and hence the film quality. X-ray diffraction analysis showed that the films were crystalline after the deposition. Electrochemical tests showed maximum power density of 510 mW cm-2 at 650 °C with a thickness average of 3.30 μm when the film was deposited in 12 cycles showing that the film has a potential to be used as an electrolyte for ITSOFC on metal support. © 2014 Elsevier B.V. All rights reserved.
Keywords: Degradation; Sintering; Solid oxide fuel cells (SOFC); Spray pyrolysis; Thin films; X ray diffraction analysis; Alternative source; Electrochemical performance; Electrochemical test; Electrolyte thin film; Gadolinia doped ceria; Gadolinium doped ceria; High power density; Maximum power density; Electrolytes

The structure of the polysaccharide isolated from Acinetobacter baumannii strain LAC-4 - Vinogradov, E.; Maclean, L.; Xu, H.H.; Chen, W. (Carbohydrate Research, 2014)
The structure of the surface polysaccharide from a hypervirulent for mice Acinetobacter baumannii strain LAC-4 was studied. The polysaccharide was built of trisaccharide repeating units containing α-l-fucosamine, α-d-glucosamine, and α-8-epi-legionaminic acid. The structure interpretation was based mostly on NMR data. Polysaccharide was obtained using a procedure of LPS O-chain preparation, although whether it is an LPS O-chain or capsular polysaccharide remained unclear. © 2014 Published by Elsevier Ltd. All rights reserved.
Keywords: Nuclear magnetic resonance; Organic compounds; Structure (composition); Synthesis (chemical); Acinetobacters; Baumannii; Capsular polysaccharides; D-glucosamine; LPS; NMR data; O-polysaccharide; Repeating unit; Chains; lipopolysaccharide; polysaccharide; trisaccharide; Acinetobacter baumannii; anion exchange chromatography; article; bacterial strain; carbohydrate analysis; gel chromatography; nonhuman; nuclear magnetic resonance spectroscopy; priority journal

Conductivity of Si(111)-(7×7): The role of a single atomic step - Martins, B.V.C.; Smeu, M.; Livadaru, L.; Guo, H.; Wolkow, R.A. (Physical Review Letters, 2014)
While it is known that the Si-(7×7) is a conducting surface, measured conductivity values differ by 7 orders of magnitude. Here we report a combined STM and transport method capable of surface conductivity measurement of step-free or single-step containing surface regions and having minimal interaction with the sample, and by which we quantitatively determine the intrinsic conductivity of the Si-(7×7) surface. We found that a single step has a conductivity per unit length about 50 times smaller than the flat surface. Our first principles quantum transport calculations confirm and lend insight into the experimental observation. © 2014 American Physical Society.
Keywords: Quantum electronics; Conducting surfaces; First-principles quantum transports; Intrinsic conductivity; Minimal interactions; Orders of magnitude; Per unit length; Surface conductivity; Transport method; Silicon

Orally delivered water soluble Coenzyme Q10 (Ubisol-Q10) blocks on-going neurodegeneration in rats exposed to paraquat: Potential for therapeutic application in Parkinson's disease - Muthukumaran, K.; Leahy, S.; Harrison, K.; Sikorska, M.; Sandhu, J.K.; Cohen, J.; Keshan, C.; Lopatin, D.; Miller, H.; Borowy-Borowski, H.; Lanthier, P.; Weinstock, S.; et al. (BMC Neuroscience, 2014)
Background: Paraquat, still used as an herbicide in some parts of the world, is now regarded as a dangerous environmental neurotoxin and is linked to the development Parkinson's disease (PD). Paraquat interacts with cellular redox systems and causes mitochondrial dysfunction and the formation of reactive oxygen species, which in turn, plays a crucial role in the pathophysiology of PD. Various antioxidant therapies have been explored with the expectations that they deliver health benefits to the PD patients, however, no such therapies were effective. Here we have tested the neuroprotective efficacy of a novel water-soluble CoQ10 (Ubisol-Q10), in a rat model of paraquat-induced neurodegeneration in order to evaluate its potential application in the management of PD.Results: We have developed a rat model of progressive nigrostriatal degeneration by giving rats five intraperitoneal injections of paraquat (10 mg/kg/injection), once every five days. Neuronal death occurred over a period of 8 weeks with close to 50% reduction in the number of tyrosine hydroxylase-positive cells. Ubisol-Q10, at 6 mg CoQ10/kg body weight/day, was delivered as a supplement in drinking water. The intervention begun after the completion of paraquat injections when the neurodegenerative process had already began and about 20% of TH-positive neurons were lost. Ubisol-Q10 treatment halted the progression of neurodegeneration and remaining neurons were protected. The outcomes were evaluated based on the number of surviving tyrosine hydroxylase-positive neurons in the substantia nigra region and improved motor skills in response to the Ubisol-Q10 intervention. To maintain this neuroprotection, however, continuous Ubisol- Q10 supplementation was required, if withdrawn, the neuronal death pathway resumed, suggesting that the presence of CoQ10 was essential for blocking the pathway.Conclusion: The CoQ10, given orally as Ubisol-Q10 in drinking solution, was effective in blocking the progression of neurodegeneration when administered therapeutically (post-toxin injection), at a much lower concentration than other previously tested oil soluble formulations and well within the acceptable daily intake of 12 mg/kg/day. Such unprecedented neuroprotection has never been reported before. These results are very encouraging and suggest that Ubisol-Q10 should be further tested and developed as a therapy for halting the progression of PD. © 2014 Muthukumaran et al.; licensee BioMed Central Ltd.
Keywords: paraquat; tyrosine 3 monooxygenase; ubiquinone; animal cell; animal experiment; animal model; animal tissue; article; brain death; cell survival; controlled study; disease course; motor performance; nerve cell; neuroprotection; neurotoxicity; nonhuman; Parkinson disease; rat; striatonigral degeneration; substantia nigra; treatment outcome

2D NMR barcoding and differential analysis of complex mixtures for chemical identification: The Actaea triterpenes - Qiu, F.; McAlpine, J.B.; Lankin, D.C.; Burton, I.; Karakach, T.; Chen, S.-N.; Pauli, G.F. (Analytical Chemistry, 2014)
The interpretation of NMR spectroscopic information for structure elucidation involves decoding of complex resonance patterns that contain valuable molecular information (δ and J), which is not readily accessible otherwise. We introduce a new concept of 2D-NMR barcoding that uses clusters of fingerprint signals and their spatial relationships in the δ-δ coordinate space to facilitate the chemical identification of complex mixtures. Similar to widely used general barcoding technology, the structural information of individual compounds is encoded as a specifics pattern of their C,H correlation signals. Software-based recognition of these patterns enables the structural identification of the compounds and their discrimination in mixtures. Using the triterpenes from various Actaea (syn. Cimicifuga) species as a test case, heteronuclear multiple-bond correlation (HMBC) barcodes were generated on the basis of their structural subtypes from a statistical investigation of their δH and δC data in the literature. These reference barcodes allowed in silico identification of known triterpenes in enriched fractions obtained from an extract of A. racemosa (black cohosh). After dereplication, a differential analysis of heteronuclear single-quantum correlation (HSQC) spectra even allowed for the discovery of a new triterpene. The 2D barcoding concept has potential application in a natural product discovery project, allowing for the rapid dereplication of known compounds and as a tool in the search for structural novelty within compound classes with established barcodes. © 2014 American Chemical Society.
Keywords: Bar codes; Mixtures; Nuclear magnetic resonance; Chemical identification; Differential analysis; Molecular information; Software-based recognition; Spatial relationships; Spectroscopic information; Structural identification; Structural information; Chemical analysis

Static and predictive tomographic reconstruction for wide-field multi-object adaptive optics systems - Correia, C.; Jackson, K.; Véran, J.-P.; Andersen, D.; Lardière, O.; Bradley, C. (Journal of the Optical Society of America A: Optics and Image Science, and Vision, 2014)
Multi-object adaptive optics (MOAO) systems are still in their infancy: their complex optical designs for tomographic, wide-field wavefront sensing, coupled with open-loop (OL) correction, make their calibration a challenge. The correction of a discrete number of specific directions in the field allows for streamlined application of a general class of spatio-angular algorithms, initially proposed in Whiteley et al. [J. Opt. Soc. Am. A 15, 2097 (1998)], which is compatible with partial on-line calibration. The recent Learn and Apply algorithm from Vidal et al. [J. Opt. Soc. Am. A 27, A253 (2010)] can then be reinterpreted in a broader framework of tomographic algorithms and is shown to be a special case that exploits the particulars of OL and aperture-plane phase conjugation. An extension to embed a temporal prediction step to tackle sky-coverage limitations is discussed. The trade-off between lengthening the camera integration period, therefore increasing system lag error, and the resulting improvement in SNR can be shifted to higher guide-star magnitudes by introducing temporal prediction. The derivation of the optimal predictor and a comparison to suboptimal autoregressive models is provided using temporal structure functions. It is shown using end-to-end simulations of Raven, the MOAO science, and technology demonstrator for the 8 m Subaru telescope that prediction allows by itself the use of 1-magnitude-fainter guide stars. © 2013 Optical Society of America.
Keywords: Adaptive optics systems; Auto regressive models; End-to-end simulation; On-line calibration; Temporal prediction; Temporal structures; Tomographic reconstruction; Wave-front sensing; Algorithms; Calibration; Optical phase conjugation; Signal to noise ratio; Stars; Tomography

Central-transition double-quantum sideband NMR spectroscopy of half-integer quadrupolar nuclei: Estimating internuclear distances and probing clusters within multi-spin networks - Brinkmann, A.; Edén, M. (Physical Chemistry Chemical Physics, 2014)
We introduce a strategy to estimate the size of clusters of recoupled homonuclear half-integer quadrupolar nuclei under magic-angle spinning (MAS) conditions, by combining double-quantum (2Q) sideband NMR experiments with an approximate numerical analysis based on the summation of all spin-pairs present over a given radius of the structure. The experiment relies solely on the evolution of homonuclear 2Q coherences (2QC) among the central-transitions (CT) of half-integer spins and is suitable for probing clusters in network structures, such as those encountered in large groups of oxide-based materials. Experimental 11B, 23Na and 27Al NMR results are presented on bis(catecholato)diboron, Na2SO4 and Al 2O3, respectively; in each case, the growth of the spin-cluster size was monitored from a series of experiments that employed progressively lengthened 2QC excitation intervals. Our new approach is the first option for probing larger constellations of half-integer spins; it provides similar information as the "multiple-quantum spin counting" experiment, which is well-established for spin-1/2 applications but has hitherto not been demonstrated for half-integer spins undergoing MAS. We also discuss various options for determining the internuclear distance within a (nearly) isolated pair of half-integer spins by comparing the experimental 2Q sideband NMR spectra with results from numerical simulations involving various degrees of approximation. © 2014 the Partner Organisations.

Silicon photonic integration platform-Have we found the sweet spot? - Xu, D.-X.; Schmid, J.H.; Reed, G.T.; Mashanovich, G.Z.; Thomson, D.J.; Nedeljkovic, M.; Chen, X.; Van Thourhout, D.; Keyvaninia, S.; Selvaraja, S.K. (IEEE Journal on Selected Topics in Quantum Electronics, 2014)
The current trend in silicon photonics towards higher levels of integration as well as the model of using CMOS foundries for fabrication are leading to a need for standardization of substrate parameters and fabrication processes. In particular, for several established research and development foundries that grant general access, silicon-on-insulator wafers with a silicon thickness of 220 nm have become the standard substrate for which devices and circuits have to be designed. In this study we investigate the role of silicon device layer thickness in design optimization of various components that need to be integrated in a typical optical transceiver, including both passive ones for routing, wavelength selection, and light coupling as well as active ones such as monolithic modulators and on-chip lasers produced by hybrid integration. We find that in all devices considered there is an advantage in using a silicon thickness larger than 220 nm, either for improved performance or for simplified fabrication processes and relaxed tolerances. © 2014 IEEE.

Enhancing optical field intensities in Gaussian-profile fiber Bragg gratings - Upham, J.; De Leon, I.; Grobnic, D.; Ma, E.; Dicaire, M.-C.N.; Schulz, S.A.; Murugkar, S.; Boyd, R.W. (Optics Letters, 2014)
Gaussian profile fiber Bragg gratings exhibit narrow-bandwidth transmission peaks with significant group delay at the edge of their photonic bandgap. We demonstrate group delays ranging from 0.2 to 5.6 ns from a 1.2 cm structure. Simulations suggest such a device would be capable of enhancing the field intensity of incoming light by a factor of 800. Enhancement is confirmed by photothermally induced bistability of these peaks even at sub-milliwatt input powers with as much as a four-fold difference in the magnitude of their responses. The strong field intensities of these modes could significantly enhance desired nonlinear optical responses in fiber, provided the impact of absorption is addressed. © 2014 Optical Society of America.
Keywords: Group delay; Field intensity; Gaussian profiles; Incoming light; Nonlinear optical response; Optical field intensity; Photothermally; Strong field; Transmission peaks; Fiber Bragg gratings

Magnetic resonance microscopy for assessment of morphological changes in hydrating hydroxypropylmethylcellulose matrix tablets in situ - is it possible to detect phenomena related to drug dissolution within the hydrated matrices? - Kulinowski, P.; Młynarczyk, A.; Jasiński, K.; Talik, P.; Gruwel, M.L.H.; Tomanek, B.; Weglarz, W.P.; Dorozyński, P. (Pharmaceutical Research, 2014)
Purpose: So far, the hydrated part of the HPMC matrix has commonly been denoted as a "gel" or "pseudogel" layer. No MRI-based results have been published regarding observation of internal phenomena related to drug dissolution inside swelling polymeric matrices during hydration. The purpose of the study was to detect such phenomena. Methods: Multiparametric, spatially and temporally resolved T2 MR relaxometry, in situ, was applied to study formation of the hydration progress in HPMC matrix tablets loaded with L-dopa and ketoprofen using a 11.7 T MRI system. Two spin-echo based pulse sequences were used, one of them specifically designed to study short T2 signals. Results: Two components in the T2 decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T2 values, were obtained. Based on the data, different region formation patterns (i.e. multilayer structure) were registered depending on drug presence and solubility. Inside the matrix with incorporated sparingly soluble drug a specific layer formation due to drug dissolution was detected, whereas a matrix with very slightly soluble drug does not form distinct external "gel-like" layer. Conclusions: We have introduced a new paradigm in the characterization of hydrating matrices using 1H MRI methods. It reflects molecular mobility and concentration of water inside the hydrated matrix. For the first time, drug dissolution related phenomena, i.e. particular front and region formation, were observed by MRI methods. © 2014 The Author(s).

Screening-level estimates of indoor exposure to volatile organic compounds emitted from building materials - Ye, Wei; Little, John C.; Won, Doyun; Zhang, Xu (Building and Environment, 2014)
Knowing the value of the key mass-transfer model parameters is a critical requirement for evaluating volatile organic compound (VOC) emissions from indoor materials. The key parameters are diffusion coefficient (D), partition coefficient (K), and initial material-phase emittable concentration (C0). Although these parameters can be individually measured in the laboratory, the required time and expense are substantial. A simple method of determining D and C0 using data from ventilated chamber tests and dimensionless analysis is proposed and then validated using VOC emission data from the material emissions database developed by National Research Council Canada (NRC). The primary application of this method is to provide a rapid screening-level estimate of inhalation exposure to VOCs in building materials. Two standard scenarios using the NRC database are employed to demonstrate the value of the approach to indoor air quality assessment. The method could be a useful screening tool for assessing material emissions or environmental exposures. © 2014 Elsevier Ltd.
Keywords: VOC; diffusion coefficient; chamber test; characteristic emission rate

Apple flavonols and n-3 polyunsaturated fatty acid-rich fish oil lowers blood C-reactive protein in rats with hypercholesterolemia and acute inflammation - Sekhon-Loodu, S.; Catalli, A.; Kulka, M.; Wang, Y.; Shahidi, F.; Rupasinghe, H.P.V. (Nutrition Research, 2014)
Both quercetin glycosides and omega-3 polyunsaturated fatty acids (n-3 PUFA) are well established for their individual health benefits in ameliorating metabolic disease. However, their combined effects are not well documented. It was hypothesized that the beneficial properties of quercetin glycosides can be enhanced when provided in combination with n-3 PUFA. Therefore, the aim of the present study was to investigate the effects of apple flavonols (AF) and fish oil (FO), alone and in combination, on proinflammatory biomarkers and lipid profiles in rats fed a high-fat diet. Sixty male Wistar rats were randomly divided into 5 groups (n = 12) and fed a high-fat diet for 4 weeks. One of the 5 groups of rats was used as the high-fat control. The other 4 groups of rats were injected with lipopolysaccharide (LPS) (5 mg/kg body weight) intraperitoneally, 5 hours before euthanization. One of these 4 groups was used as the hypercholerolemic and inflammatory control (high-fat with lipopolysaccharide [HFL]), and the other 3 received AF (HFL + 25 mg/kg per day AF), FO (HFL + 1 g/kg per day FO), or the combination (HFL + AF + FO). Compared to the HFL group, the AF, FO, and AF + FO groups showed lower serum concentrations of interleukin-6 and C-reactive protein (CRP) levels. The AF, FO, and AF + FO also had lowered serum triacylglycerol and non-high-density lipoprotein cholesterol (HDL-C) concentrations, but higher HDL-C levels relative to the HFL group. An additive effect was observed on serum CRP in the AF + FO group as compared with the AF or FO groups. The results demonstrated that AF and FO inhibited the production of proinflammatory mediators and showed an improved efficacy to lower serum CRP when administered in combination, and they significantly improved blood lipid profiles in rats with diet-induced hyperlipidemia and LPS-induced acute inflammation. © 2014 Elsevier Inc. All rights reserved.

Characterization of optical coherence tomography images acquired at large distances with large-diameter beams - Popescu, D.P.; Smith, M.S.D.; Sowa, M.G. (IEEE Photonics Journal, 2014)
We tested the imaging capabilities for variants of a 1550-nm swept-source fiber-based optical coherence tomography system with a telecentric system incorporated at the end of its sample arm. The system was designed for in vivo imaging of burns; therefore, we acquired images from samples located at distances greater than 24 cm from the exit of the telecentric system. Each system variation had a specific combination of diameters for the reference and sample beams. In the reference arm, we used, alternately, two collimated beams with diameters of 1.5 and 14 mm, respectively. In the sample arm, we tested collimated beams with the following diameters: 1.5, 3.5, 5.7, 8.4, and 14 mm. A galvanometric mirror system scanned the collimated sample beam across the entrance pupil of the telecentric system. The sample beam exited the telecentric system parallel with its optical axis and convergent onto the sample. Depending on the collimator used in the sample arm, images were acquired with beams focused to waist diameters ranging from 40 to 240 μm. We acquired images with the sample at different locations within a ±30 mm range centered about the sample beam waist. Furthermore, we used the signal-to-noise ratio, the detected signal intensity, and the visual appearance to compare images acquired with different sample/reference beam configurations. © 2014 IEEE.
Keywords: Image analysis; Molecular physics; Photonics; Speckle; Beam configuration; Collimated beams; Imaging capabilities; Medical optics instrumentation; Signal intensities; System variations; Telecentric system; Visual appearance; Optical tomography

The Smn-independent beneficial effects of trichostatin a on an intermediate mouse model of spinal muscular atrophy - Liu, H.; Yazdani, A.; Murray, L.M.; Beauvais, A.; Kothary, R. (PLoS ONE, 2014)
Spinal muscular atrophy is an autosomal recessive neuromuscular disease characterized by the progressive loss of alpha motor neurons in the spinal cord. Trichostatin A (TSA) is a histone deacetylase inhibitor with beneficial effects in spinal muscular atrophy mouse models that carry the human SMN2 transgene. It is currently unclear whether TSA specifically targets the SMN2 gene or whether other genes respond to TSA and in turn provide neuroprotection in SMA mice. We have taken advantage of the Smn2B/- mouse model that does not harbor the human SMN2 transgene, to test the hypothesis that TSA has its beneficial effects through a non-SMN mediated pathway. TSA increased the median lifespan of Smn2B/- mice from twenty days to eight weeks. As well, there was a significant attenuation of weight loss and improved motor behavior. Pen test and righting reflex both showed significant improvement, and motor neurons in the spinal cord of Smn2B/- mice were protected from degeneration. Both the size and maturity of neuromuscular junctions were significantly improved in TSA treated Smn2B/- mice. Of interest, TSA treatment did not increase the levels of Smn protein in mouse embryonic fibroblasts or myoblasts obtained from the Smn2B/- mice. In addition, no change in the level of Smn transcripts or protein in the brain or spinal cord of TSA-treated SMA model mice was observed. Furthermore, TSA did not increase Smn protein levels in the hind limb muscle, heart, or liver of Smn2B/- mice. We therefore conclude that TSA likely exerts its effects independent of the endogenous mouse Smn gene. As such, identification of the pathways regulated by TSA in the Smn 2B/- mice could lead to the development of novel therapeutics for treating SMA. © 2014 Liu et al.

Developing trends in aptamer-based biosensor devices and their applications - Mackay, S.; Wishart, D.; Xing, J.Z.; Chen, J. (IEEE Transactions on Biomedical Circuits and Systems, 2014)
Aptamers are, in general, easier to produce, easier to store and are able to bind to a wider variety of targets than antibodies. For these reasons, aptamers are gaining increasing popularity in environmental monitoring as well as disease detection and disease management applications. This review article examines the research and design of RNA and DNA aptamer based biosensor systems and applications as well as their potential for integration in effective biosensor devices. As single stranded DNA or RNA molecules that can bind to specific targets, aptamers are well suited for biomolecular recognition and sensing applications. Beyond being able to be designed for a near endless number of specific targets, aptamers can also be made which change their conformation in a predictable and consistent way upon binding. This can lead to many unique and effective detection methods using a variety of optical and electrochemical means. © 2007-2012 IEEE.
Keywords: Antibodies; Carbon nanotubes; Chemical detection; RNA; Aptamers; Biomolecular recognition; ELectrochemical detection; Environmental Monitoring; Optical detection; SELEX; Sensing applications; Single-stranded DNA; Biosensors

Diverse metastable structures formed by small oligomers of α-synuclein probed by force spectroscopy - Neupane, K.; Solanki, A.; Sosova, I.; Belov, M.; Woodside, M.T. (PLoS ONE, 2014)
Oligomeric aggregates are widely suspected as toxic agents in diseases caused by protein aggregation, yet they remain poorly characterized, partly because they are challenging to isolate from a heterogeneous mixture of species. We developed an assay for characterizing structure, stability, and kinetics of individual oligomers at high resolution and sensitivity using single-molecule force spectroscopy, and applied it to observe the formation of transient structured aggregates within single oligomers of α-synuclein, an intrinsically-disordered protein linked to Parkinson's disease. Measurements of the molecular extension as the proteins unfolded under tension in optical tweezers revealed that even small oligomers could form numerous metastable structures, with a surprisingly broad range of sizes. Comparing the structures formed in monomers, dimers and tetramers, we found that the average mechanical stability increased with oligomer size. Most structures formed within a minute, with size-dependent rates. These results provide a new window onto the complex α-synuclein aggregation landscape, characterizing the microscopic structural heterogeneity and kinetics of different pathways. © 2014 Neupane et al.
Keywords: alpha synuclein; dimer; monomer; oligomer; tetramer; animal cell; article; controlled study; enzyme kinetics; mathematical computing; molecular probe; molecular stability; nonhuman; oligomerization; optical tweezers; Parkinson disease; particle size; protein aggregation; protein stability; protein structure; single molecule force spectroscopy; spectroscopy

Optimization of enzyme assisted extraction of polysaccharides from Astragalus membranaceus - Chen, H.; Zhou, X.; Zhang, J. (Carbohydrate Polymers, 2014)
Astragalus polysaccharide (APS) is known to have a variety of pharmacological activities. In the present study, enzyme assisted extraction of APS from Astragalus mongholicus using various enzymes were examined. Research found that glucose oxidase offered a better performance in enhancement of extraction yields of APS than other ones. Glucose oxidase assisted extraction process was further optimized by using response surface method (RSM) to obtain maximum yield of crude APS. The optimized extraction conditions were as follows: enzyme amount of 3.0%, enzyme treated time of 3.44 d, enzyme treated temperature of 56.9 °C and extraction solvent pH of 7.8. Under these conditions, the experimental yield was 29.96 ± 0.14%, which was well in close agreement with the value (30.19%) predicted by RSM model and increased more than 250% compared with none enzyme treated ones. Pharmacological test showed that enzyme assisted APS had a better antioxidant activity (about 2 times higher) than none enzyme treated ones. © 2014 Elsevier Ltd.
Keywords: Extraction; Glucose oxidase; Glucose sensors; Polysaccharides; Surface properties; Anti-oxidant activities; Astragalus membranaceus; Astragalus mongholicus; Astragalus polysaccharides; Enzyme-assisted extractions; Extraction conditions; Pharmacological activity; Response surface method; Enzymes

Stimulus-selective regulation of human mast cell gene expression, degranulation and leukotriene production by fluticasone and salmeterol - Catalli, A.; Karpov, V.; Erdos, L.E.; Tancowny, B.P.; Schleimer, R.P.; Kulka, M. (PLoS ONE, 2014)
Despite the fact that glucocorticoids and long acting beta agonists are effective treatments for asthma, their effects on human mast cells (MC) appear to be modest. Although MC are one of the major effector cells in the underlying inflammatory reactions associated with asthma, their regulation by these drugs is not yet fully understood and, in some cases, controversial. Using a human immortalized MC line (LAD2), we studied the effects of fluticasone propionate (FP) and salmeterol (SM), on the release of early and late phase mediators. LAD2 cells were pretreated with FP (100 nM), SM (1 μM), alone and in combination, at various incubation times and subsequently stimulated with agonists substance P, C3a and IgE/anti-IgE. Degranulation was measured by the release of β-hexosaminidase. Cytokine and chemokine expression were measured using quantitative PCR, ELISA and cytometric bead array (CBA) assays. The combination of FP and SM synergistically inhibited degranulation of MC stimulated with substance P (33% inhibition compared to control, n = 3, P< .05). Degranulation was inhibited by FP alone, but not SM, when MC were stimulated with C3a (48% inhibition, n = 3, P<.05). As previously reported, FP and SM did not inhibit degranulation when MC were stimulated with IgE/anti-IgE. FP and SM in combination inhibited substance P-induced release of tumor necrosis factor (TNF), CCL2, and CXCL8 (98%, 99% and 92% inhibition, respectively, n = 4, P<.05). Fluticasone and salmeterol synergistically inhibited mediator production by human MC stimulated with the neuropeptide substance P. This synergistic effect on mast cell signaling may be relevant to the therapeutic benefit of combination therapy in asthma. © 2014 Catalli et al.
Keywords: beta n acetylhexosaminidase; complement component C3a; fluticasone propionate; immunoglobulin E; immunoglobulin E antibody; interleukin 8; leukotriene; monocyte chemotactic protein 1; salmeterol; substance P; tumor necrosis factor; article; cell stimulation; combination chemotherapy; concentration response; controlled study; cytokine production; drug mechanism; drug potentiation; enzyme release; gene expression regulation; human; human cell; incubation time; intracellular signaling; mast cell degranulation; monotherapy

Hydrogen-catalyzed, pilot-scale production of small-diameter boron nitride nanotubes and their macroscopic assemblies - Kim, Keun Su; Kingston, Christopher T.; Hrdina, Amy; Jakubinek, Michael B.; Guan, Jingwen; Plunkett, Mark; Simard, Benoit (ACS Nano, 2014)
Boron nitride nanotubes (BNNTs) exhibit a range of properties that are as compelling as those of carbon nanotubes (CNTs); however, very low production volumes have prevented the science and technology of BNNTs from evolving at even a fraction of the pace of CNTs. Here we report the high-yield production of small-diameter BNNTs from pure hexagonal boron nitride powder in an induction thermal plasma process. Few-walled, highly crystalline small-diameter BNNTs (∼5 nm) are produced exclusively and at an unprecedentedly high rate approaching 20 g/h, without the need for metal catalysts. An exceptionally high cooling rate (∼105 K/s) in the induction plasma provides a strong driving force for the abundant nucleation of small-sized B droplets, which are known as effective precursors for small-diameter BNNTs. It is also found that the addition of hydrogen to the reactant gases is crucial for achieving such high-quality, high-yield growth of BNNTs. In the plasma process, hydrogen inhibits the formation of N2 from N radicals and promotes the creation of B-N-H intermediate species, which provide faster chemical pathways to the re-formation of a h-BN-like phase in comparison to nitridation from N2. We also demonstrate the fabrication of macroscopic BNNT assemblies such as yarns, sheets, buckypapers, and transparent thin films at large scales. These findings represent a seminal milestone toward the exploitation of BNNTs in real-world applications. © Published 2014 by the American Chemical Society.
Keywords: Boron nitride; Carbon nanotubes; Plasmas; Boron nitride nanotubes (BNNTs); Hexagonal boron nitride; High quality; Induction thermal plasma; large scale; Pilot-scale production; Assembly

Polar lipids from the marine macroalga Palmaria palmata inhibit lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells - Banskota, A.H.; Stefanova, R.; Sperker, S.; Lall, S.P.; Craigie, J.S.; Hafting, J.T.; Critchley, A.T. (Phytochemistry, 2014)
The EtOAc soluble fraction of a MeOH/CHCl3 extract of Palmaria palmata showed strong nitric oxide (NO) inhibitory activity against lipopolysaccharide (LPS)-induced NO production in murine RAW264.7 cells. NO inhibition-guided isolation led to identification of three new polar lipids including a sulfoquinovosyl diacylglycerol (SQDG) (2S)-1-O-eicosapentaenoyl-2-O- myristoyl-3-O-(6-sulfo-α-d-quinovopyranosyl)-glycerol (1) and two phosphatidylglycerols, 1-O-eicosapentaenoyl-2-O-trans-3-hexadecenoyl-3-phospho- (1′-glycerol)-glycerol (3) and 1-O-eicosapentaenoyl-2-O-palmitoyl-3- phospho-(1′-glycerol)-glycerol (4) from the EtOAc fraction. Seven known lipids were also isolated including a SQDG (2), a phospholipid (5) and five galactolipids (6-10). Structures of the isolated lipids were elucidated by spectral analyses. The isolated SQDGs, phosphatidylglycerols and phospholipid possessed strong and dose-dependent NO inhibitory activity compared to N G-methyl-l-arginine acetate salt (l-NMMA), a well-known NO inhibitor used as a positive control. Further study suggested that these polar lipids suppressed NO production through down-regulation of inducible nitric oxide synthase (iNOS).
Keywords: Murinae; Palmaria palmata; Palmariaceae; Rhodymenia palmata

Liquid chromatography/mass spectrometry of domoic acid and lipophilic shellfish toxins with selected reaction monitoring and optional confirmation by library searching of product ion spectra - McCarron, P.; Wright, E.; Quilliam, M.A. (Journal of AOAC International, 2014)
LC/MS methodology for the analysis of domoic acid and lipophilic toxins in shellfish was developed using a hybrid triple quadrupole linear ion trap mass spectrometer. For routine quantitation a scheduled selected reaction monitoring (SRM) method for the analysis of domoic acid, okadaic acid, dinophysistoxins, azaspiracids, pectenotoxins, yessotoxins, gymnodimines, spirolides, and pinnatoxins was developed and validated. The method performed well in terms of LOD, linearity, precision, and trueness. Taking advantage of the high instrument sensitivity, matrix effects were mitigated by reducing the amount of sample introduced to the mass spectrometer. Optionally, samples can be analyzed using information dependent acquisition (IDA) methods, either in positive or negative mode, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a sample with those from a specially constructed spectral library. Methods were applied to the analysis of a new certified reference material and Canadian mussels (Mytilus edulis) implicated in a 2011 diarrhetic shellfish poisoning (DSP) incident. The scheduled SRM method enabled the screening and quantitation of multiple phycotoxins. As DSP had not previously been observed in this area of Canada, positive identification of putative toxins was accomplished using the IDA and spectral search method. Analysis of the 2011 toxic mussel samples revealed the presence of high levels of dinophysistoxin-1, which explained the DSP symptoms, as well as pectenotoxins, yessotoxins, and variety of cyclic imines. © 2014 Publishing Technology.
Keywords: Mass spectrometers; Mass spectrometry; Metabolites; Molluscs; Shellfish; Certified reference materials; Diarrhetic shellfish poisoning; Hybrid triple quadrupole-linear ion trap mass spectrometer; Information-dependent acquisitions; Liquid chromatography/mass spectrometry; Product ion spectra; Selected reaction monitoring; Spectral libraries; Toxic materials; domoic acid; drug derivative; kainic acid; lipid; marine toxin; animal; article; chemistry; food analysis; liquid chromatography; mass spectrometry; methodology; molecular library; reproducibility; shellfish; Animals; Chromatography, Liquid; Food Analysis; Kainic Acid; Lipids; Marine Toxins; Mass Spectrometry; Reproducibility of Results; Shellfish; Small Molecule Libraries

Discovering biological patterns from short time-series gene expression profiles with integrating PPI data - Fan, Wei-Wei; Chen, Bolin; Selvaraj, Gopalan; Wu, Fang-Xiang (Neurocomputing, 2014)
As genes with similar functions are closely related, cluster analysis becomes an important tool to understand and predicts gene functions (patterns) from gene expression profiles. In many situations, each gene expression profile only contains a few data points. Directly applying traditional clustering algorithms to such short gene expression profiles cannot obtain biological meaningful patterns. In this paper, we propose a novel method to discover biologically meaningful patterns by clustering short time-series gene expression profiles with integrating protein-protein interaction (PPI) data. Numerical experiments are conducted on two sets of Arabidopsis thaliana short time-series gene expression profiles, with treatments of cold stress and drought stress, respectively. The proposed method can effectively assign genes belonging to target functional clusters (patterns), in terms of having small p-value of GO term 'response to cold' (GO:0009409) in dataset one, and small p-value of GO term 'response to water deprivation' (GO:0009414) in dataset two than those from an existing clustering algorithm (namely STEM) for short time-series gene expression profiles. Additionally, our proposed method is able to identify higher percentage of stress-related genes and un-annotated genes in resultant cluster than STEM for both datasets; which does not only improve gene clustering effectiveness, but also contribute to functional prediction of un-annotated genes.
Keywords: Pattern discovery; Cluster analysis; Short time-series gene expression profile; Protein–protein interaction; GO term

Microstructure, bioactivity and wear resistance of sintered composite Co-Cr-Mo/Bioglass® for medical implant applications - Cai, F.; Miyata, C.; Huang, X.; Yang, Q. (International Journal of Surface Science and Engineering, 2014)
A sintered Co-Cr-Mo/Bioglass® composite coating, developed for medical implant application, is examined and compared to plasma-sprayed and sintered monolithic Co-Cr-Mo coatings. In addition to microstructure and wear resistance analysis, the bioactivities and corrosion behaviours of various coatings are assessed using simulated body fluid (SBF) immersion. The sintered Co-Cr-Mo/Bioglass® composite and monolithic Co-Cr-Mo coatings have more porous structure than the plasma sprayed Co-Cr-Mo coating. Although the Co-Cr-Mo/Bioglass® composite coating has adequate bonding between Co-Cr-Mo powder and glass particles, the wear resistance is lower than the plasma sprayed Co-Cr-Mo and Stellite 21 substrate. After SBF immersion, calcium is present on the Co-Cr-Mo/Bioglass composite coating, but not on the Co-Cr-Mo coating. It indicates the formation of an apatite layer on the Co-Cr- Mo/Bioglass composite coating and potentially better bioactivity than the monolithic coatings. Copyright © 2014 Inderscience Enterprises Ltd.
Keywords: Bioactivity; Composite coatings; Composite materials; Glass bonding; Microhardness; Microstructure; Phosphate minerals; Plasma jets; Plasma spraying; Sintering; Wear of materials; Wear resistance; Apatite layers; Corrosion behaviour; Glass particles; Medical implants; Monolithic coatings; Porous structures; Resistance analysis; Simulated body fluids; Chromate coatings

Allosteric noncompetitive small molecule selective inhibitors of CD45 tyrosine phosphatase suppress T-cell receptor signals and inflammation in vivo - Perron, M.D.; Chowdhury, S.; Aubry, I.; Purisima, E.; Tremblay, M.L.; Uri Saragovi, H. (Molecular Pharmacology, 2014)
CD45 is a receptor-like member of the protein tyrosine phosphatase (PTP) family. We screened in silico for small molecules binding at a predicted allosteric pocket unique to the CD45 intracellular domain, and validated inhibitors by in vitro phosphatase assays. Compound 211 exhibited a CD45 IC 50 value of 200 nM and had >.100-fold selectivity over six related PTPs. The relevance of the allosteric pocket was verified through site-directed mutagenesis. Compound 211 has a noncompetitive mechanism of action, and it is extremely effective at preventing dephosphorylation of substrate Lck phosphotyrosine (pY)-505 versus preventing dephosphorylation of Lck pY-393. In cultured primary T cells, compound 211 prevents T-cell receptor-mediated activation of Lck, Zap-70, and mitogen-activated protein kinase, and interleukin-2 production. In a delayed-type hypersensitivity reaction in vivo, compound 211 abolished inflammation. This work demonstrates a novel approach to develop effective allosteric inhibitors that can be expanded to target the corresponding allosteric domains of other receptor PTPs.
Keywords: CD45 antigen; compound 211; interleukin 2; mitogen activated protein kinase; protein kinase Lck; protein kinase ZAP 70; protein tyrosine phosphatase inhibitor; T lymphocyte receptor; unclassified drug; animal cell; animal experiment; animal model; article; assay; binding site; cell activity; computer model; controlled study; cytokine production; delayed hypersensitivity; drug dose escalation; drug potency; drug selectivity; female; IC 50; immunosuppressive treatment; in vivo study; inflammation; lymphocytic infiltration; molecular docking; mouse; neutropenia; nonhuman; priority journal; protein dephosphorylation; signal transduction; single drug dose; site directed mutagenesis; spleen cell; T lymphocyte; Allosteric Regulation; Allosteric Site; Animals; Antigens, CD45; Cells, Cultured; Enzyme Activation; Female; Hypersensitivity, Delayed; Immunologic Factors; Immunosuppressive Agents; Inflammation; Interleukin-2; Lymphocyte Specific Protein Tyrosine Kinase p56(lck); Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Molecular Docking Simulation; Mutagenesis, Site-Directed; Naphthoquinones; Phosphorylation; Phosphotyrosine; Receptors, Antigen, T-Cell; Signal Transduction; Structure-Activity Relationship; ZAP-70 Protein-Tyrosine Kinase

Robustness of tungsten single atom tips to thermal treatment and air exposure - Vesa, C.; Urban, R.; Pitters, J.L.; Wolkow, R.A. (Applied Surface Science, 2014)
Experiments aimed at assessing the robustness of nitrogen-etched, single-atom tips (SATs) prepared using W(1 1 1) single crystal wire were performed. Our experiments showed that single-atoms tips sustain minimal damage when exposed to atmospheric conditions and can be readily and quickly nitrogen-etched to single-atom tips thereafter. The SATs can be annealed at temperatures up to 1100 C with minimal shape changes. Moreover, annealing temperatures in excess of 1200 C resulted in an apex faceting which may prove important in further single-atom tip creation. Procedures for warming of the SATs from operating temperatures of 80 K were also evaluated to determine conditions that limit tip contamination. These results show that SATS could be fabricated in a dedicated vacuum system and subsequently transferred to other instruments where they would undergo a brief conditioning procedure to recover the single-atom apex configuration prior to being subjected to operating conditions.. © 2014 Elsevier B.V.
Keywords: Experiments; Gas industry; Ion sources; Nitrogen; Single crystals; Faceting; Field ion microscopy; Gas assisted etchings; Gas field ion sources; Single atoms; Atoms

Identification of susceptibility variants in ADIPOR1 gene associated with type 2 diabetes, coronary artery disease and the comorbidity of type 2 diabetes and coronary artery disease - Jin, Z.; Pu, L.; Sun, L.; Chen, W.; Nan, N.; Li, H.; Zhu, H.; Yang, X.; Wang, N.; Hui, J.; Zhang, Y.; Zhou, Q.; et al. (PLoS ONE, 2014)
Objective: Adiponectin receptor 1 (encoded by ADIPOR1) is one of the major adiponectin receptors, and plays an important role in glucose and lipid metabolism. However, few studies have reported simultaneous associations between ADIPOR1 variants and type 2 diabetes (T2D), coronary artery disease (CAD) and T2D with CAD. Based on the "common soil" hypothesis, we investigated whether ADIPOR1 polymorphisms contributed to the etiology of T2D, CAD, or T2D with CAD in a Northern Han Chinese population. Methods: Our multi-disease comparison study enrolled 657 subjects, including 165 with T2D, 173 with CAD, 174 with both T2D and CAD (T2D+CAD), and 145 local healthy controls. Six ADIPOR1 single nucleotide polymorphisms (SNPs) were genotyped and their association with disease risk was analyzed. Results: Multi-case-control comparison identified two ADIPOR1 variants: rs3737884-G, which was simultaneously associated with an increased risk of T2D, CAD, and T2D+CAD (P-value range, 9.80×10-5-6.30×10-4; odds ratio (OR) range: 1.96-2.42) and 16850797-C, which was separately associated with T2D and T2D+CAD (P-value range: 0.007-0.014; OR range: 1.71-1.77). The risk genotypes of both rs3737884 and 16850797 were consistently associated with common metabolic phenotypes in all three diseases (P-value range: 4.81×10 -42-0.001). We observed an increase in the genetic dose-dependent cumulative risk with increasing risk allele numbers in T2D, CAD and T2D+CAD (Ptrend from 1.35×10-5-0.002). Conclusions: Our results suggest that ADIPOR1 risk polymorphisms are a strong candidate for the "common soil" hypothesis and could partially contribute to disease susceptibility to T2D, CAD, and T2D with CAD in the Northern Han Chinese population. © 2014 Jin et al.
Keywords: adiponectin receptor 1; AdipoR1 gene; adult; aged; article; case control study; comorbidity; controlled study; coronary artery disease; female; genetic association; genetic risk; genetic susceptibility; genotype; Han Chinese; human; major clinical study; male; non insulin dependent diabetes mellitus; single nucleotide polymorphism

Irradiation behaviour of α2 and γ phases in He ion implanted titanium aluminide alloy - Zhu, H.; Wei, T.; Blackford, M.; Short, K.; Carr, D.; Harrison, R.; Edwards, L.; Seo, D.; Maruyama, K. (Intermetallics, 2014)
A Ti-45Al-2Nb-2Mn + 0.8 vol.% TiB2 (at.%) alloy with fully lamellar microstructure consisting of hexagonal-close-packed (hcp) α2 and face-centred-tetragonal (fct) γ phases was irradiated by implanting helium ions to different fluences. Microstructural examination showed that helium cavities are formed in both the α2 and γ phases after He-ion irradiation. However, the helium cavities and their size change with fluence are much larger in the α2 phase than those in the γ phase, indicating that the γ phase exhibits better tolerance to the He-ion irradiation than the α2 phase. Since α2 and γ phases have different crystal structures, they possess differences in helium solubility and interstitial migration. These differences are responsible for the variation in radiation damage behaviour between the two phases. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Defects: constitutional vacancies; F. Electron microscopy , transmission; Hexagonal close packed; Interstitial migration; Irradiation effect; Microstructural examination; Titanium aluminide alloy; Titanium aluminides , based on TiAl; Helium; Ions; Irradiation; Niobium; Radiation damage; Titanium; Titanium alloys

Structure of poly(N-isopropylacrylamide) brushes and steric stability of their grafted cellulose nanocrystal dispersions - Hemraz, U.D.; Lu, A.; Sunasee, R.; Boluk, Y. (Journal of Colloid and Interface Science, 2014)
Thermo-responsive poly (N-isopropylacrylamide) (poly(NIPAAm)) brushes were grafted from the surface of cellulose nanocrystals (CNC) via living radical polymerization (LRP) using different initiator and monomer concentrations. The dry film thickness of the poly(NIPAAm) layer around CNC was calculated based on Scanning Electron Microscopy (SEM) and dynamic light scattering (DLS) measurements. The wet film thicknesses of grafted poly(NIPAAm) brushes in water were calculated to be 15 and 9. nm for NIPAAm-CNC-1 and NIPAAm-CNC-2, respectively. Grafted chain densities and wet film thicknesses at below and above the critical temperature (T= 34. °C) of polyNIPAAm were calculated by applying mean-field analytical theory. The non-ionic poly(NIPAAm) brushes screened the surface charges of CNC particles, leading to a significant decrease in the absolute zeta potential values for the poly(NIPAAm) grafted CNCs compared to the unmodified and initiator modified CNC samples. Nevertheless, the colloidal stability of poly(NIPAAm) grafted CNC particles were still maintained by steric stabilization below the critical temperature On the other side, hydrophobic attractions among poly(NIPAAm) grafted CNC rods above 34. °C lead to coagulation and phase separation. While both poly(NIPAAm) grafted CNC samples showed thermo-responsive behavior, the reversibility of this temperature triggered property was dependent on grafting density. © 2014 Elsevier Inc.
Keywords: Acrylic monomers; Brushes; Cellulose derivatives; Colloids; Convergence of numerical methods; Dynamic light scattering; Film thickness; Living polymerization; Phase separation; Scanning electron microscopy; Stabilization; Temperature; Cellulose nano-crystals; Cellulose nanocrystal (CNC); Hydrophobic attraction; Living radical polymerization; Poly (n isopropylacrylamide); Rod-like particles; Steric; Thermo-responsive behaviors; Grafting (chemical); amide; bromine; carbon; carbonyl derivative; cellulose; hydroxyl group; monomer; nanocrystal; nitrogen; oxygen; poly(n isopropylacrylamide); sulfate; article; chemical modification; chemical structure; diffusion coefficient; dispersion; film; gel permeation chromatography; hydrolysis; infrared spectroscopy; light scattering; macromolecule; molecular weight; phase separation; polymerization; priority journal; scanning electron microscopy; scanning transmission electron microscopy; surface charge; surface property; temperature; thickness; transition temperature; X ray photoelectron spectroscopy; zeta potential; Acrylic Compounds; Cellulose Derivatives; Colloids; Monomers; Optical Scattering; Polymerization; Scanning Electron Microscopy; Stabilization; Temperature

Temperature coefficients of the refractive index for complex hydrocarbon mixtures - Wen, Q.; Shen, J.; Gieleciak, R.; Michaelian, K.H.; Rohling, J.H.; Astrath, N.G.C.; Baesso, M.L. (International Journal of Thermophysics, 2014)
Temperature coefficients of the refractive index ((Formula presented.)) in the (Formula presented.) to (Formula presented.) temperature interval for hydrocarbon mixtures containing as many as 14 compounds were investigated in this work. The measured (Formula presented.) of the mixtures were compared with calculations based on the values for each compound and their concentrations. Differences of about 1 % between measured and calculated values were observed for all mixtures. The additivity of (Formula presented.) for these hydrocarbons enables preparation of surrogate fuels that are formulated to have properties like those of specific diesel fuels. © 2014 Crown Copyright.

Development of a vectored vaccine against Hepatitis E virus - Trabelsi, K.; Kamen, A.; Kallel, H. (Vaccine, 2014)
Hepatitis E virus is a non-enveloped ssRNA virus [1] that causes human acute hepatitis through primarily fecal and oral transmission [2]. Currently, no commercial hepatitis E (HEV) vaccine is available. In the absence of an appropriate cell culture system for HEV propagation, HEV pseudocapsids (ORF2 protein) have been produced either in Escherichia coli or in insect cells and they have been shown to protect monkeys against virus challenge and to be effective in the prevention of natural HEV infection of humans.In this work, we propose to develop a novel candidate vaccine against hepatitis E infection using adeno-associated virus (AAV) as a vector expressing the gene of the truncated capsid protein of HEV (aa 112-aa 660). rAAV will be produced in Sf9 cells using the baculovirus expression vector system.For this purpose, construction of recombinant baculoviruses was performed and viral stocks of BacRep, BacCap for serotypes 2, 5 and 6 were prepared in Sf9 cells. The recombinant baculovirus coding for the truncated capsid protein of HEV (BacITRHEVORF2) was also constructed, the virus titer was equal to 5.41×109PFU/mL, at the third passage. Transduction of HEK 293 EBNA cells with rAAV was carried out; the production of HEVORF2 was confirmed by Western blot. Optimization of rAAV production in Sf9 cells is currently ongoing. © 2014 Elsevier Ltd.
Keywords: baculovirus vector; capsid protein; hepatitis E vaccine; parvovirus vector; article; baculovirus expression system; cell density; cell viability; controlled study; expression vector; HEK293 cell line; hepatitis E; Hepatitis E virus; human; human cell; MTT assay; nonhuman; priority journal; protein expression; SF9 cell line; virus recombinant; Western blotting

Tractography of meyer's loop asymmetries - Dreessen de Gervai, P.; Sboto-Frankenstein, U.N.; Bolster, R.B.; Thind, S.; Gruwel, M.L.H.; Smith, S.D.; Tomanek, B. (Epilepsy Research, 2014)
Purpose: The purpose of the current study was to use diffusion tensor imaging (DTI) to conduct tractography of the optic radiations (OR) and its component bundles and to assess both the degree of hemispheric asymmetry and the inter-subject variability of Meyer's Loop (ML). We hypothesized that there are significant left versus right differences in the anterior extent of ML to the temporal pole (TP) in healthy subjects. Materials and methods: DTI data were acquired on a 3. T Siemens MRI system using a single-shot Spin Echo EPI sequence. The dorsal, central and ML bundles of the OR were tracked and visualized in forty hemispheres of twenty healthy volunteers. The uncinate fasciculus (UF) was also tracked in these subjects so that it could be used as a distinct anatomical reference. Measurements were derived for the distance between ML-TP, ML and the temporal horn (ML-TH) and ML and the uncinate fasciculus (ML-UF). Paired difference t-tests were carried out with SPSS 14.0. Results: ML and the UF were successfully tracked and visualized in all 20 volunteers. Significant hemispheric asymmetries were found for all measurements with left distances shorter than the right (P < 0.005). In 50% of the subjects the left ML-UF distance was ≤1.9. mm. Conclusion: The results support our hypothesis and demonstrate that left ML-TP distances are significantly shorter than right ML-TP distances. These asymmetries are also reflected in shorter left distances between ML-TH and ML-UF. Moreover, these results are of interest to left-sided temporal lobe epilepsy surgery because it is not only more likely to disturb the anterior extent of ML but also renders the often closely located posterior aspect of the left UF more vulnerable to potential surgical impact.
Keywords: Meyer's Loop; Asymmetry; Optic radiations; Diffusion tensor imaging

Numerical study of confined laminar CH4/air diffusion flames established in an inverted burner - Liu, F.; Smallwood, G.J. (Combustion Science and Technology, 2014)
Several experimental studies have demonstrated that confined laminar diffusion flames established in an inverted burner are very stable and emit soot when the global equivalence ratio exceeds a critical value. An inverted diffusion flame can be used as a stable source of soot particles for development and intercomparison of various particle sizing techniques. Unlike normal coflow diffusion flames fired upward, inverted diffusion flames fired downward experience a negative gravity, the resultant flow fields are very different, and the residence time is significantly prolonged. The different flow fields in normal and inverted diffusion flames mean that the flame structure and soot formation characteristics are significantly different. This study makes a first attempt to numerically investigate the flame properties and soot formation in confined laminar coflow CH4/air diffusion flames established in an inverted axisymmetric burner at atmospheric pressure. A fairly detailed reaction mechanism, GRI Mech 3.0, was used to model combustion chemistry. Soot formation was modeled using a semi-empirical, acetylene-based, two-equation soot model. Radiation heat transfer was calculated using the discrete-ordinates method and a wide-band non-gray gas model. Numerical calculations were conducted over a relatively narrow range of global equivalence ratio of 0.54-0.67 based on a recent experimental study. The heat transfer boundary condition was found to be important to the prediction of soot emission and the velocity distribution. Using measured temperature distribution along the quartz tube, the numerical model successfully predicted the emission of soot under the conditions investigated and revealed the flow, temperature, and species concentration distributions in the inverted coflow diffusion flames for the first time. However, the predicted primary soot particle diameters are significantly smaller than those reported in the literature based on TEM images analysis of sampled soot. The discrepancies between the numerical results and experimental data can be attributed to the deficiency of the simple soot model and the approximate treatment of the heat transfer boundary conditions at the quartz tube. Copyright © Crown.
Keywords: Air; Atmospheric pressure; Boundary conditions; Combustion; Computer simulation; Diffusion; Dust; Flow fields; Heat transfer; Residence time distribution; Coflow diffusion flames; Detailed reaction mechanisms; Diffusion Flame; Discrete-ordinates method; Global equivalence ratio; Laminar diffusion flames; Particle sizing techniques; Species concentration; Soot

Milk sphingomyelin domains in biomimetic membranes and the role of cholesterol: Morphology and nanomechanical properties investigated using AFM and force spectroscopy - Guyomarc'H, F.; Zou, S.; Chen, M.; Milhiet, P.-E.; Godefroy, C.; Vié, V.; Lopez, C. (Langmuir, 2014)
Milk sphingomyelin (MSM) and cholesterol segregate into domains in the outer bilayer membrane surrounding milk fat globules. To elucidate the morphology and mechanical properties of theses domains, supported lipid bilayers with controlled molar proportions of MSM, dioleoylphosphatidylcholine (DOPC) and cholesterol were produced in buffer mimicking conditions of the milk aqueous phase. Atomic force microscopy imaging showed that (i) for T < 35 °C MSM segregated in gel phase domains protruding above the fluid phase, (ii) the addition of 20 mol % cholesterol resulted in smaller and more elongated l o phase domains than in equimolar MSM/DOPC membranes, (iii) the MSM/cholesterol-enriched lo phase domains were less salient than the MSM gel phase domains. Force spectroscopy measurements furthermore showed that cholesterol reduced the resistance of MSM/DOPC membrane to perforation. The results are discussed with respect to the effect of cholesterol on the biophysical properties of lipid membranes. The combination of AFM imaging and force mapping provides unprecedented insight into the structural and mechanical properties of milk lipid membranes, and opens perspectives for investigation of the functional properties of MSM domains during milk fat processing or digestion. © 2014 American Chemical Society.
Keywords: Atomic force microscopy; Biomimetics; Lipid bilayers; Mechanical properties; Morphology; Oils and fats; Phospholipids; Biomimetic membrane; Biophysical properties; Dioleoylphosphatidylcholine; Functional properties; Morphology and mechanical properties; Nanomechanical property; Structural and mechanical properties; Supported lipid bilayers; Cholesterol

Formulation-properties versatility of wood fiber biocomposites based on polylactide and polylactide/thermoplastic starch blends - Mihai, M.; Legros, N.; Alemdar, A. (Polymer Engineering and Science, 2014)
This article discusses the interrelation between formulation, processing, and properties of biocomposites composed of a bioplastic reinforced with wood fibers. Polylactide (PLA) and polylactide/thermoplastic starch blends (PLA/TPS) were used as polymeric matrices. Two grades of PLA, an amorphous and a semicrystalline one, were studied. TPS content in the PLA/TPS blends was set at 30, 50, and 70 wt%. Two types of wood fiber were selected, a hardwood (HW) and a softwood (SW), to investigate the effect of the fiber type on the biocomposite properties. Finally, the impact of different additives on biocomposite properties was studied with the purpose to enhance the bioplastic/wood fiber adhesion and, therefore, the final mechanical performance. The biocomposites containing 30 wt% of wood fibers were obtained by twin-screw extrusion. The properties of the biocomposites are described in terms of morphology, thermal, rheological, and mechanical properties. Furthermore, the biocomposites were tested for humidity and water absorption and biodegradability. An almost 100% increase in elastic modulus and 25% in tensile strength were observed for PLA/wood fiber biocomposite with the best compatibilization strategy used. The presence of the TPS in the biocomposites at 30 and 50 wt% maintained the tensile strength higher or at least equal as for the virgin PLA. These superior tensile results were due to the inherent affinity between the matrices and wood fibers improved by the addition of a combination of coupling and a branching agent. In addition to their outstanding mechanical performance, the biocomposites showed high biodegradation within 60 days. POLYM. ENG. SCI., 54:1325-1340, 2014. © Her Majesty the Queen in Right of Canada 2013 © Her Majesty the Queen in Right of Canada 2013.
Keywords: Biodegradation; Fibers; Mechanical properties; Polyesters; Starch; Tensile strength; Wood products; Bio-composites; Branching Agent; Mechanical performance; Poly lactide; Polymeric matrices; Semicrystallines; Starch blends; Twin screw extrusion; Composite materials; Biodegradation; Composites; Fibers; Mechanical Properties; Polyesters; Starch; Tensile Strength; Wood Products

Cloning and characterization of the first GH10 and GH11 xylanases from Rhizopus oryzae - Xiao, Zhizhuang; Grosse, Stephan; Bergeron, Hélène; Lau, Peter C. K. (Applied Microbiology and Biotechnology, 2014)
The only available genome sequence for Rhizopus oryzae strain 99-880 was annotated to not encode any β-1,4-endoxylanase encoding genes of the glycoside hydrolase (GH) family 10 or 11. Here, we report the identification and cloning of two such members in R. oryzae strain NRRL 29086. Strain 29086 was one of several selected fungi grown on wheat or triticale bran and screened for xylanase activity among other hydrolytic actions. Its high activity (138 U/ml) in the culture supernatant led to the identification of two activity-stained proteins, designated Xyn-1 and Xyn-2 of respective molecular masses 32,000 and 22,000. These proteins were purified to electrophoretic homogeneity and characterized. The specific activities of Xyn-1 and Xyn-2 towards birchwood xylan were 605 and 7,710 U/mg, respectively. Kinetic data showed that the lower molecular weight Xyn-2 had a higher affinity (Km = 3.2 ± 0.2 g/l) towards birchwood xylan than Xyn-1 by about 4-fold. The melting temperature (Tm) of the two proteins, estimated to be in the range of 49.5-53.7 °C indicated that they are rather thermostable proteins. N-terminal and internal peptide sequences were obtained by chemical digestion of the purified xylanases to facilitate cloning, expression in Escherichia coli, and sequencing of the respective gene. The cloned Rhizopus xylanases were used to demonstrate release of xylose from flax shives-derived hemicellulose as model feedstock. Overall, this study expands the catalytic toolbox of GH10 and 11 family proteins that have applications in various industrial and bioproducts settings.
Keywords: Rhizopus oryzae; Endoxylanase; GH family 10 and 11; Penicillium; Triticale; Zygomycete; Flax shives

Simultaneous instantaneous measurements of soot volume fraction, primary particle diameter, and aggregate size in turbulent buoyant diffusion flames - Crosland, B.M.; Thomson, K.A.; Johnson, M.R. (Proceedings of the Combustion Institute, 2014)
Understanding the mechanisms of soot formation, growth, oxidation, and emission is important for diverse reasons including better combustor design, quantifying soot's contribution to climate change, and mitigating air quality concerns. Instantaneous soot measurement in turbulent flames is difficult, and has mostly been restricted to high-momentum jet flames and pool fires. The current work partially fills this gap by presenting simultaneous measurements of soot volume fraction (fv ), effective aggregate radius of gyration (Rgm 1), and primary particle diameter (dp ) in combination with separately-acquired measurements of mean gas velocity, within a range of turbulent buoyant non-premixed jet flames burning a fuel mixture representative of associated gas flares in the upstream oil and gas industry. Fifteen cases comprising six possible nozzle exit velocities and four nozzle diameters were studied. Histograms of fv and dp support the suggestion that reduced fv near the flame tip results from increased soot intermittency rather than reduced local fv . Furthermore, the data indicate that oxidation of mature soot structures occurs rapidly and completely, and is insensitive to the local fv . For most conditions studied, centerline fv shows self-similar behavior when scaled by measured flame height in the axial direction. The more buoyancy-dominated flames show a marked increase in peak fv that occurs lower in flame-length-normalized coordinates, while the more momentum-dominated flames show a decreased peak fv that occurs higher in flame-length-normalized coordinates. Low in the flame, soot is only present in an annular region where fv, dp, and Rgm 1 all grow. Once soot is present on the centerline, dp growth slows and dp is relatively constant at all radial locations and all conditions higher in the flame. Aggregate size continues to grow steadily with increased flame height and correlates well with residence time when adjusted to account for differing flow fields close to the burner outlet. © 2014.

Synthetic observations of the evolution of starless cores in a molecular cloud simulation: Comparisons with JCMT data and predictions for ALMA - Mairs, S.; Johnstone, D.; Offner, S.S.R.; Schnee, S. (The Astrophysical Journal, 2014)
Interpreting the nature of starless cores has been a prominent goal in star formation for many years. In order to characterize the evolutionary stages of these objects, we perform synthetic observations of a numerical simulation of a turbulent molecular cloud. We find that nearly all cores that we detect are associated with filaments and eventually form protostars. We conclude that observed starless cores that appear Jeans unstable are only marginally larger than their respective Jeans masses (within a factor of three). We note single dish observations such as those performed with the James Clerk Maxwell Telescope appear to miss significant core structure on small scales because of beam averaging. Finally, we predict that interferometric observations with Atacama Large Millimeter Array Cycle 1 will resolve the important small-scale structure, which has so far been missed by millimeter wavelength observations. © 2014. The American Astronomical Society. All rights reserved..

Single-electron dynamics of an atomic silicon quantum dot on the H-Si (100)- (2×1) surface - Taucer, M.; Livadaru, L.; Piva, P.G.; Achal, R.; Labidi, H.; Pitters, J.L.; Wolkow, R.A. (Physical Review Letters, 2014)
Here we report the direct observation of single electron charging of a single atomic dangling bond (DB) on the H-Si(100)-2×1 surface. The tip of a scanning tunneling microscope is placed adjacent to the DB to serve as a single-electron sensitive charge detector. Three distinct charge states of the dangling bond - positive, neutral, and negative - are discerned. Charge state probabilities are extracted from the data, and analysis of current traces reveals the characteristic single-electron charging dynamics. Filling rates are found to decay exponentially with increasing tip-DB separation, but are not a function of sample bias, while emptying rates show a very weak dependence on tip position, but a strong dependence on sample bias, consistent with the notion of an atomic quantum dot tunnel coupled to the tip on one side and the bulk silicon on the other. © 2014 American Physical Society.

Screening and identification of soybean seed-specific genes by using integrated bioinformatics of digital differential display, microarray, and RNA-seq data - Yin, G.; Xu, H.; Liu, J.; Gao, C.; Sun, J.; Yan, Y.; Hu, Y. (Gene, 2014)
Soybean is one of the most economically important crops in the world. Soybean seeds have abundant protein and lipid content and very high economic value. In this study, a total of 184 seed-specific genes were obtained using online microarray databases, DDD, and RNA-seq data. The reported seed-specific genes in soybean and the 184 seed-specific genes analyzed in this paper were compared. Of the screened genes, 26 were common to both previous reports and the current screening. Meanwhile, 90 of the 184 genes have homologous counterparts in Arabidopsis, among which 24 have seed-specific expression, as indicated by microarray data for Arabidopsis. Furthermore, promoter analysis showed that almost all seed-specific genes contain at least one seed specific-related element. Seed-specific element Skn-1 motif exists in most, if not all, of the seed-specific genes screened. Five genes were randomly selected from 184 soybean seed specific gene pool and their expressions were quantified using quantitative real time polymerase chain reaction (qRT-PCR) to further confirm the specificity of the screened genes. The results indicated that all five genes showed seed-specific expression. Moreover, the identification of genes with seed-specific expression screened in this study provides information valuable to the in-depth study of soybean. © 2014 Elsevier B.V.

Laser surface texturing of gray cast iron for improving tribological behavior - Bathe, R.; Sai Krishna, V.; Nikumb, S.K.; Padmanabham, G. (Applied Physics A: Materials Science and Processing, 2014)
Laser surface texturing process involves creation of microfeatures, e.g., tiny dimples, usually distributed in a certain pattern, covering only a fraction of the surface of the material that is being treated. The process offers several advantages for tribological applications, including improved load capacity, wear resistance, lubrication lifetime, and reduced friction coefficient. In the present study, the surface modification of gray cast iron, using millisecond (λ = 1,064 nm), nanosecond (λ = 1,064 nm) and femtosecond (λ = 800 nm) pulse duration laser irradiation, is adopted to establish a particular geometrical pattern with dimple features and dimensions, to improve wear and friction behavior. The effect of various laser processing parameters, including laser pulse energy, pulse duration and processing speed, on the performance characteristics of the laser-treated samples is investigated. The microtextured surfaces were produced on gray cast iron using different millisecond (0.5 ms), nanosecond (40 ns) and femtosecond (120 fs) laser source with the dimple depth between 3 and 15 μm. The coefficient of friction for the untextured surface was ~0.55, millisecond laser textured ~0.31, nanosecond laser textured ~0.02 and femtosecond laser ~0.01, under normal force of 50 N and sliding speed of 63 mm/s. Surface texturing of the gray cast iron surface using femtosecond pulse duration resulted in significant improvement in wear resistance in comparison to the untextured as well as millisecond and nanosecond laser-textured surface. © 2014 Springer-Verlag Berlin Heidelberg.

Bulge mass is king: The dominant role of the bulge in determining the fraction of passive galaxies in the sloan digital sky survey - Bluck, A.F.L.; Trevor Mendel, J.; Ellison, S.L.; Moreno, J.; Simard, L.; Patton, D.R.; Starkenburg, E. (Monthly Notices of the Royal Astronomical Society, 2014)
We investigate the origin of galaxy bimodality by quantifying the relative role of intrinsic and environmental drivers to the cessation (or 'quenching') of star formation in over half a million local Sloan Digital Sky Survey galaxies. Our sample contains a wide variety of galaxies at z = 0.02-0.2, with stellar masses of 8 < log(M*/M⊙) < 12, spanning the entire morphological range from pure discs to spheroids, and over four orders of magnitude in local galaxy density and halo mass. We utilize published star formation rates and add to this recent GIM2D photometric and stellar mass bulge + disc decompositions from our group.We find that the passive fraction of galaxies increases steeply with stellar mass, halo mass, and bulge mass, with a less steep dependence on local galaxy density and bulge-to-total stellarmass ratio (B/T). At fixed internal properties, we find that central and satellite galaxies have different passive fraction relationships. For centrals, we conclude that there is less variation in the passive fraction at a fixed bulge mass, than for any other variable, including total stellar mass, halo mass, and B/T. This implies that the quenching mechanism must be most tightly coupled to the bulge.We argue that radio-mode active galactic nucleus feedback offers the most plausible explanation of the observed trends. © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society.

Texture development in a friction stir lap-welded AZ31B magnesium alloy - Naik, B.S.; Chen, D.L.; Cao, X.; Wanjara, P. (Metallurgical and Materials Transactions A, 2014)
The present study was aimed at characterizing the microstructure, texture, hardness, and tensile properties of an AZ31B-H24 Mg alloy that was friction stir lap welded (FSLWed) at varying tool rotational rates and welding speeds. Friction stir lap welding (FSLW) resulted in the presence of recrystallized grains and an associated hardness drop in the stir zone (SZ). Microstructural investigation showed that both the AZ31B-H24 Mg base metal (BM) and SZ contained β-Mg17Al12 and Al8Mn5 second phase particles. The AZ31B-H24 BM contained a type of basal texture (0001)〈11(Formula presented.)0〉 with the (0001) plane nearly parallel to the rolled sheet surface and 〈11(Formula presented.)0〉 directions aligned in the rolling direction. FSLW resulted in the formation of another type of basal texture (0001)〈10(Formula presented.)0〉 in the SZ, where the basal planes (0001) became slightly tilted toward the transverse direction, and the prismatic planes (10(Formula presented.)0) and pyramidal planes (10(Formula presented.)1) exhibited a 30 deg + (n - 1) × 60 deg rotation (n = 1, 2, 3, ...) with respect to the rolled sheet normal direction, due to the shear plastic flow near the pin surface that occurred from the intense local stirring. With increasing tool rotational rate and decreasing welding speed, the maximum intensity of the basal poles (0001) in the SZ decreased due to a higher degree of dynamic recrystallization that led to a weaker or more random texture. The tool rotational rate and welding speed had a strong effect on the failure load of FSLWed joints. A combination of relatively high welding speed (20 mm/s) and low tool rotational rate (1000 rpm) was observed to be capable of achieving a high failure load. This was attributed to the relatively small recrystallized grains and high intensity of the basal poles in the SZ arising from the low heat input as well as the presence of a small hooking defect. © 2014 The Minerals, Metals & Materials Society and ASM International.

Apolipoprotein E, amyloid-beta, and neuroinflammation in Alzheimer's disease - Dorey, E.; Chang, N.; Liu, Q.Y.; Yang, Z.; Zhang, W. (Neuroscience Bulletin, 2014)
Alzheimer's disease (AD) is characterized by the accumulation and deposition of amyloid-beta (Aβ) peptides in the brain. Neuroinflammation occurs in the AD brain and plays a critical role in the neurodegenerative pathology. Particularly, Aβ evokes an inflammatory response that leads to synaptic dysfunction, neuronal death, and neurodegeneration. Apolipoprotein E (ApoE) proteins are involved in cholesterol transport, Aβ binding and clearance, and synaptic functions in the brain. The ApoE4 isoform is a key risk factor for AD, while the ApoE2 isoform has a neuroprotective effect. However, studies have reached different conclusions about the roles of the isoforms; some show that both ApoE3 and ApoE4 have anti-inflammatory effects, while others show that ApoE4 causes a predisposition to inflammation or promotes an inflammatory response following lipopolysaccharide treatment. These discrepancies may result from the differences in models, cell types, experimental conditions, and inflammatory stimuli used. Further, little was known about the role of ApoE isoforms in the Aβ-induced inflammatory response and in the neuroinflammation of AD. Our recent work showed that ApoE isoforms differentially regulate and modify the Aβ-induced inflammatory response in neural cells, with ApoE2 suppressing and ApoE4 promoting the response. In this article, we review the roles, mechanisms, and interrelations among Aβ, ApoE, and neuroinflammation in AD. © 2014 Shanghai Institutes for Biological Sciences, CAS and Springer-Verlag.
Keywords: amyloid beta protein; apolipoprotein E; apolipoprotein E2; apolipoprotein E3; apolipoprotein E4; lipopolysaccharide; Alzheimer disease; cell type; cholesterol transport; disease predisposition; human; nerve cell; nerve cell necrosis; nerve degeneration; nervous system inflammation; neuropathology; nonhuman; review; risk factor; synapse

Determination of mercury in gasoline by photochemical vapor generation coupled to graphite furnace atomic absorption spectrometry - de Jesus, Alexandre; Sturgeon, Ralph E.; Liu, Jixin; Silva, Márcia M. (Microchemical Journal, 2014)
Quantitation of mercury in gasoline by graphite furnace atomic absorption spectrometry following its photochemical vapor generation is described. Samples were prepared as a mixture of gasoline and propan-2-ol. A high efficiency flow through 19W photochemical vapor generator was used to process prepared samples with in-situ collection of the resultant Hg0 vapor onto reduced palladium in the graphite tube. Response from inorganic and organomercury standards added to the samples did not differ significantly. A limit of detection and characteristic mass of 0.1μgL-¹ and 0.6ng were obtained, respectively. Relative standard deviations of replicate measurements of 3.0ngmL-1 added Hg(II) were typically 7-8%. Recoveries of spikes from samples ranged from 90 to 97%. The concentration of mercury in all tested samples of gasoline was below the limit of quantitation (0.3μgL-¹). The method was rapid, efficient, green, fit-for-purpose, responsive to both inorganic and organic mercury species and should also respond to any Hg0 endogenously present in the sample. © 2014 Elsevier B.V.

Prospects for measuring supermassive black hole masses with future extremely large telescopes - Do, T.; Wright, S.A.; Barth, A.J.; Barton, E.J.; Simard, L.; Larkin, J.E.; Moore, A.M.; Wang, L.; Ellerbroek, B. (Astronomical Journal, 2014)
The next generation of giant-segmented mirror telescopes (>20 m) will enable us to observe galactic nuclei at much higher angular resolution and sensitivity than ever before. These capabilities will introduce a revolutionary shift in our understanding of the origin and evolution of supermassive black holes by enabling more precise black hole mass measurements in a mass range that is unreachable today. We present simulations and predictions of the observations of nuclei that will be made with the Thirty Meter Telescope (TMT) and the adaptive optics assisted integral-field spectrograph IRIS, which is capable of diffraction-limited spectroscopy from Z band (0.9 μm) to K band (2.2 μm). These simulations, for the first time, use realistic values for the sky, telescope, adaptive optics system, and instrument to determine the expected signal-to-noise ratio of a range of possible targets spanning intermediate mass black holes of 104 M⊙to the most massive black holes known today of >1010 M ⊙. We find that IRIS will be able to observe Milky Way mass black holes out the distance of the Virgo Cluster, and will allow us to observe many more of the brightest cluster galaxies where the most massive black holes are thought to reside. We also evaluate how well the kinematic moments of the velocity distributions can be constrained at the different spectral resolutions and plate scales designed for IRIS. We find that a spectral resolution of 8000 will be necessary to measure the masses of intermediate mass black holes. By simulating the observations of galaxies found in Sloan Digital Sky Survey DR7, we find that over 105 massive black holes will be observable at distances between 0.005 < z < 0.18 with the estimated sensitivity and angular resolution provided by access to Z-band (0.9 μm) spectroscopy from IRIS and the TMT adaptive optics system. These observations will provide the most accurate dynamical measurements of black hole masses to enable the study of the demography of massive black holes, address the origin of the M BH-σ and M BH-L relationships, and evolution of black holes through cosmic time. © 2014. The American Astronomical Society. All rights reserved..

Single-molecule force spectroscopy of rapidly fluctuating, marginally stable structures in the intrinsically disordered protein α -synuclein - Solanki, A.; Neupane, K.; Woodside, M.T. (Physical Review Letters, 2014)
Intrinsically disordered proteins form transient, fluctuating structures that are difficult to observe directly. We used optical tweezers to apply force to single α-synuclein molecules and measure their extension, characterizing the resulting conformational transitions. Force-extension curves revealed rapid fluctuations at low force, arising from the folding of two different classes of structure that were only marginally stable. The energy landscape for these transitions was characterized via the force-dependent kinetics derived from correlation analysis of the extension trajectories. The barriers were small, only a few kBT, but the diffusion was slow, revealing a landscape that is flat but rough. © 2014 American Physical Society.
Keywords: Optical tweezers; Proteins; Conformational transitions; Correlation analysis; Different class; Energy landscape; Force-extension curves; Intrinsically disordered proteins; Single molecule force spectroscopy; Stable structures; Molecules; alpha synuclein; DNA; article; atomic force microscopy; chemical model; chemistry; methodology; protein conformation; protein folding; protein stability; spectroscopy; thermodynamics; alpha-Synuclein; DNA; Microscopy, Atomic Force; Models, Chemical; Protein Conformation; Protein Folding; Protein Stability; Spectrum Analysis; Thermodynamics

Laser micromachining of oxygen reduced graphene-oxide films - Sinar, D.; Knopf, G.K.; Nikumb, S.; Andrushchenko, A. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Non-conductive graphene-oxide (GO) inks can be synthesized from inexpensive graphite powders and deposited on functionalized flexible substrates using inkjet printing technology. Once deposited, the electrical conductivity of the GO film can be restored through laser assisted thermal reduction. Unfortunately, the inkjet nozzle diameter (∼40μm) places a limit on the printed feature size. In contrast, a tightly focused femtosecond pulsed laser can create precise micro features with dimensions in the order of 2 to 3 μm. The smallest feature size produced by laser microfabrication is a function of the laser beam diameter, power level, feed rate, material characteristics and spatial resolution of the micropositioning system. Laser micromachining can also remove excess GO film material adjacent to the electrode traces and passive electronic components. Excess material removal is essential for creating stable oxygen-reduced graphene-oxide (rGO) printed circuits because electron buildup along the feature edges will alter the conductivity of the non-functional film. A study on the impact of laser ablation on the GO film and the substrate are performed using a 775nm, 120fs pulsed laser. The average laser power was 25mW at a spot size of ∼ 5μm, and the feed rate was 1000-1500mm/min. Several simple microtraces were fabricated and characterized in terms of electrical resistance and surface topology. © 2014 SPIE.
Keywords: Composite micromechanics; Ink; Laser ablation; Microanalysis; Microfabrication; Micromachining; Oxide films; Oxygen; Pulsed lasers; Substrates; Electrical conductivity; Femtosecond pulsed laser; Ink-jet printing technologies; Laser micro-fabrication; Laser micro-machining; Material characteristics; Passive electronic components; Thermal reduction; Graphene

In a glycosylation reaction how does a hydroxylic nucleophile find the activated anomeric carbon? - Whitfield, D.M. (Carbohydrate Research, 2014)
The mechanism by which nucleophilic hydroxyls are attracted to activated glycopyranosyl donors is not known. Besides the intrinsic attraction of oxygen centred negative dipoles towards the developing electron deficiency at the anomeric carbon only a few suggestions have been given in the literature. By studying the effect on Density Functional Theory (DFT) modelled glycosylation reactions on the presence of polar additives as tested with acetonitrile two possible effects have been identified. One was noted in a previous publication ( Carbohydr. Res. 2012, 356, 180-190) and two further examples discovered here that suggest that a lone pair of a nucleophile approaching a donor with a β-leaving group from the α-face can act as the antiperiplanar lone pair that assists leaving group departure. This interaction starts at just under a nucleophile C-1 separation of 3. Å and has an incipient bond angle of O-5-C-1-Nuc(O or N) of very close to 90° which can be at C-1 with the p-type orbital at C-1-O-5 of the incipient oxacarbenium ion, that is, the LUMO of the activated donor. The 2nd interaction is less well studied and is suggested to be a similar bonding interaction which moves β-face nucleophiles to O-Nuc-C-1-leaving groups angles close to 180°.

Assessment of tissue oxygenation of periodontal inflammation in smokers using optical spectroscopy - Liu, K.-Z.; Duarte, P.M.; Santos, V.R.; Xiang, X.; Xu, M.; Miranda, T.S.; Fermiano, D.; Gonçalves, T.E.D.; Sowa, M.G. (Journal of Clinical Periodontology, 2014)
Background We have recently developed a periodontal diagnostic tool that was validated in non-smokers with periodontitis. Tobacco smoking is a recognized risk factor for periodontal diseases that can mask gingival bleeding and lead to a false negative diagnosis. Therefore, the purpose of current study is to further validate this instrument in smokers with periodontal diseases. Methods Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed and evaluated from healthy (n = 108), gingivitis (n = 100), and periodontitis (n = 79) sites of 54 systemically healthy smokers. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of deoxygenated haemoglobin (Hb) and oxygenated haemoglobin (HbO2) to the overall spectrum. The balance between tissue oxygen delivery and utilization in periodontal tissues was then assessed. Results Tissue oxygen saturation was significantly decreased in the gingivitis (p = 0.016) and periodontitis (p = 0.007) sites, compared to the healthy sites. There was a trend towards increased concentration of Hb and decreased concentration of HbO2 from healthy to diseased sites, without statistical significance (p > 0.05). Conclusions Optical spectroscopy can determine tissue oxygenation profiles of healthy and diseased sites in smokers. The spectral profile of periodontal sites in smokers generally resembles those from non-smoking patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Further study of the optimisation of the tractive efficiency of all-wheel-drive vehicles - Huang, W.; Wong, J.Y.; Knezevic, Z. (International Journal of Heavy Vehicle Systems, 2014)
This paper examines the tractive efficiency of all-wheel-drive vehicles in general and the slip efficiency in particular. It focuses on the analysis of the conditions for achieving the optimal slip efficiency. Results of detailed theoretical analyses indicate that all drive wheels operating at the same slip will be the necessary and sufficient conditions for achieving the optimal slip efficiency, if their thrust-slip relationships are either linear or nonlinear with similar characteristics. If the thrust-slip relationships of the drive wheels are nonlinear with different characteristics, the optimal slip efficiency will be reached with the slips of the drive wheels not being equal. The basic findings of this investigation are substantiated with experimental data. The results of this study suggest that the requirement for all drive wheels operating at the same slip provides a reasonable basis for a practical control strategy of an active system to distribute torque (thrust) among the drive wheels to achieve the optimal (or close to the optimal) slip efficiency of all-wheel-drive vehicles under most operating conditions. Copyright © 2014 Inderscience Enterprises Ltd.
Keywords: Digital storage; Efficiency; Off road vehicles; Optimization; Vehicle wheels; Vehicles; All-wheel drives; Distribution of torque (thrust); Linear or nonlinear thrust-slip relationship; Tractive efficiency; Tractive performance; Wheeled vehicles; All wheel drive vehicles

Effect of past delivery practices on current conditions of cast-iron water pipes - Rajani, B.; Dickinson, J.; Xue, H.; Woodard, P.; Canas, R. (Journal of Infrastructure Systems, 2014)
Cast-iron pipes installed between 1850 and the early 1960s in North America, United Kingdom, and European countries were produced in foundries located near growing urban centers. Their considerable weight, size (especially larger-diameter pipes), and limited transportation facilities made their handling and delivery to the installation site difficult. Historical anecdotal evidence exists to suggest that some cast-iron pipes may have been damaged during delivery. This paper examines different mechanical models to examine what specific conditions may have led to pipe damage during delivery and installation. Analyses show that if pipes did incur damage, then cracks were likely to have occurred on the inside of the pipe bell or spigot ends. Furthermore, it appears that the spigot ends of smaller-diameter pipes had higher risk of damage during delivery, whereas both bell and spigot ends faced increased risk of damage in larger-diameter pipes. Monte Carlo simulations were conducted to account for uncertainties in the parameters that were used in the different models. © 2013 American Society of Civil Engineers.

Effect of health protective factors on health deficit accumulation and mortality risk in older adults in the Beijing longitudinal study of aging - Wang, C.; Song, X.; Mitnitski, A.; Fang, X.; Tang, Z.; Yu, P.; Rockwood, K. (Journal of the American Geriatrics Society, 2014)
Objectives: To evaluate transitions in health status and risk of death in older adults in relation to baseline health deficits and protective factors. Design: Prospective cohort study with reassessments at 5, 8, and 15 years. Setting: Secondary analysis of data from the Beijing Longitudinal Study on Aging. Participants: Urban and rural community-dwelling people aged 55 and older at baseline (n = 3,275), followed from 1992 to 2007, during which time 51% died. Measurements: Health status was quantified using the deficit accumulation-based frailty index (FI), constructed from 30 intrinsic health measures. A protection index was constructed using 14 extrinsic items (e.g., exercise, education). The probabilities of health changes, including death, were evaluated using a multistate transition model. Results: Women had more health deficits (mean baseline FI 0.13 ± 0.11) than did men (mean baseline FI 0.11 ± 0.10). Although health declined on average (mean FIs increased), improvement and stability were common. Baseline health significantly affected health transitions and survival over various follow-up durations (odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.17-1.37 for men; OR = 1.24, 95% CI = 1.16-1.33 for women for each increment of deficits). Each protective factor reduced the risk of health decline and the risk of death in men and women by 13% to 25%. Conclusion: Deficit accumulation-based transition modeling demonstrates persisting effects of baseline health status on age-related health outcomes. Some mitigation by protective factors can be demonstrated, suggesting that improving physical and social conditions might be beneficial. © 2014, The American Geriatrics Society.
Keywords: aged; aging; article; Center for Epidemiological Studies Depression Scale; China; cohort analysis; daily life activity; educational status; exercise; female; follow up; frailty index; health deficit; health status; human; longevity; longitudinal study; major clinical study; male; Mini Mental State Examination; mortality; population dynamics; prospective study; protection index; rural population; secondary analysis; survival; urban population

Dynamical evolution of viscous disks around be stars. II. Polarimetry - Haubois, X.; Mota, B.C.; Carciofi, A.C.; Draper, Z.H.; Wisniewski, J.P.; Bednarski, D.; Rivinius, T. (The Astrophysical Journal, 2014)
Be stars exhibit variability for a great number of observables. Putting the pieces of the disk dynamics together is not an easy task and requires arduous modeling before achieving a good fit to the observational data. In order to guide the modeling process and make it more efficient, it is very instructive to investigate reference dynamical cases. This paper focuses on continuum polarimetric quantities and is the second of a series that aims to demonstrate the capacity of deriving the dynamical history and fundamental parameters of a classical Be star through follow-up of various observables. After a detailed study of the different opacities at play in the formation of polarized spectra, we investigate predictions of polarimetric observables in the continuum for different dynamical scenarios. Our models are based on a coupling of a hydrodynamic viscous decretion simulations in a disk and a three-dimensional non-LTE radiative transfer code. Through introduction of the polarization color diagram (PCD), we show that certain combinations of polarimetric observables exhibit features that are characteristic of a mass-loss history. This diagram also enables estimates of fundamental parameters such as the inclination angle, disk density scale, and the α viscous diffusion parameter. We present the PCD as a powerful diagnosis tool to track the dynamical phases of a Be star, such as disk build-up, dissipation, periodic, and episodic outbursts. Finally, we confront our models with observations of four Be stars that exhibited long-term polarimetric activity. © 2014. The American Astronomical Society. All rights reserved..

The proteome of mouse cerebral arteries - Badhwar, A.; Stanimirovic, D.B.; Hamel, E.; Haqqani, A.S. (Journal of Cerebral Blood Flow and Metabolism, 2014)
The cerebral vasculature ensures proper cerebral function by transporting oxygen, nutrients, and other substances to the brain. Distribution of oxygenated blood throughout the neuroaxis takes place at the level of the circle of Willis (CW). While morphologic and functional alterations in CW arteries and its main branches have been reported in cerebrovascular and neurodegenerative diseases, accompanying changes in protein expression profiles remain largely uncharacterized. In this study, we performed proteomics to compile a novel list of proteins present in mouse CW arteries and its ramifications. Circle of Willis arteries were surgically removed from 6-month-old wild-type mice, proteins extracted and analyzed by two proteomics approaches, gel-free nanoLC-mass spectrometry (MS)/MS and gel-based GelLC-MS/MS, using nanoAcquity UPLC coupled with ESI-LTQ Orbitrap XL. The two approaches helped maximize arterial proteome coverage. Six biologic and two technical replicates were performed. In all, 2,188 proteins with at least 2 unique high-scoring peptides were identified (6,630 proteins total). Proteins were classified according to vasoactivity, blood-brain barrier specificity, tight junction and adhesion molecules, membrane transporters/channels, and extracellular matrix/basal lamina proteins. Furthermore, we compared the identified CW arterial proteome with the published brain microvascular proteome. Our database provides a vital resource for the study of CW cerebral arterial protein expression profiles in health and disease. © 2014 ISCBFM All rights reserved.
Keywords: carrier protein; cell adhesion molecule; membrane protein; proteome; scleroprotein; tight junction protein; amino acid sequence; animal tissue; artery wall; article; basement membrane; blood brain barrier; blood vessel reactivity; brain artery; brain circulus arteriosus; male; mass spectrometer; mouse; nonhuman; nucleotide sequence; priority journal; protein analysis; protein database; protein expression; protein function; protein isolation; proteomics; tandem mass spectrometry; ultra performance liquid chromatography; unindexed sequence; wild type

APOE and APOC1 gene polymorphisms are associated with cognitive impairment progression in Chinese patients with late-onset Alzheimer's disease - Zhou, Q.; Peng, D.T.; Yuan, X.R.; Lv, Z.P.; Pang, S.H.; Jiang, W.Y.; Yang, C.Y.; Shi, X.H.; Pang, G.F.; Yang, Y.G.; Xie, H.Q.; Zhang, W.D.; et al. (Neural Regeneration Research, 2014)
Current evidence shows that apolipoprotein E (APOE), apolipoprotein CI (APOC1) and low density lipoprotein receptor-related protein (LRP) variations are related to late-onset Alzheimer's disease. However, it remains unclear if genetic polymorphisms in these genes are associated with cognitive decline in late-onset Alzheimer's disease patients. We performed a 30-month longitudinal cohort study to investigate the relationship between Alzheimer's disease and APOE, APOC1, and LRP. In this study, 78 Chinese Han patients with late-onset Alzheimer's disease were recruited form Guangxi Zhuang Autonomous Region in China. APOE, APOC1, and LRP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphisms. The Mini-Mental State Examination and Clinical Dementia Rating Scale were used to assess patients' cognitive function. After a 30-month follow-up period, we found a significant reduction in Mini-Mental State Examination total score, a higher proportion of patients fulfilling cognitive impairment progression criteria, and a higher proportion of APOC1 H2 carriers in APOE ε4 carriers compared with non-carriers. In addition, the APOE ε4 allele frequency was significantly higher in the cognitive impairment progression group compared with the non-cognitive impairment progression group. In conclusion, APOE ε4 plays an important role in augmenting cognitive decline, and APOC1 H2 may act synergistically with APOE ε4 in increasing the risk of cognitive decline in Chinese patients with late-onset Alzheimer's disease.
Keywords: aged; Alzheimer disease; apolipoprotein CI gene; apolipoprotein E gene; article; cognition; cognitive defect; cohort analysis; disease association; disease course; DNA extraction; DNA polymorphism; female; follow up; gel electrophoresis; gene; gene frequency; gene interaction; genotype; human; longitudinal study; low density lipoprotein receptor related protein gene; major clinical study; male; outcome assessment; polymerase chain reaction; rating scale; restriction fragment length polymorphism; scoring system; ultraviolet spectrophotometry

Relationship between the spectral line based weighted-sum-of-gray-gases model and the full spectrum k-distribution model - Chu, H.; Liu, F.; Consalvi, J.-L. (Journal of Quantitative Spectroscopy and Radiative Transfer, 2014)
The relationship between the spectral line based weighted-sum-of-gray-gases (SLW) model and the full-spectrum k-distribution (FSK) model in isothermal and homogeneous media is investigated in this paper. The SLW transfer equation can be derived from the FSK transfer equation expressed in the k-distribution function without approximation. It confirms that the SLW model is equivalent to the FSK model in the k-distribution function form. The numerical implementation of the SLW relies on a somewhat arbitrary discretization of the absorption cross section whereas the FSK model finds the spectrally integrated intensity by integration over the smoothly varying cumulative-k distribution function using a Gaussian quadrature scheme. The latter is therefore in general more efficient as a fewer number of gray gases is required to achieve a prescribed accuracy. Sample numerical calculations were conducted to demonstrate the different efficiency of these two methods. The FSK model is found more accurate than the SLW model in radiation transfer in H2O; however, the SLW model is more accurate in media containing CO2 as the only radiating gas due to its explicit treatment of 'clear gas.'. © 2014 Published by Elsevier Ltd.
Keywords: Carbon dioxide; Frequency shift keying; Absorption cross sections; Full spectrum k distributions; Gas radiation; Global models; Numerical implementation; SLW; Weighted-sum-of-gray-gases; Weighted-sum-of-gray-gases models; Spectroscopy; absorption; accuracy assessment; gas; Gaussian method; numerical model; radiative transfer; spectrum

Uncertainties in seakeeping analysis and related loads and response procedures - Kim, Y.; Hermansky, G. (Ocean Engineering, 2014)
This paper presents the uncertainties in seakeeping analysis and the related International Towing Tank Conference (ITTC) procedures for loads and responses for waves. One of the emerging issues in ITTC activities is uncertainty analysis. ITTC (2008) has published a report with recommendations for uncertainty analysis for ship model testing, which summarized the fundamentals and examples of uncertainty analysis. Furthermore, a specific description focusing on seakeeping experiments was introduced by the Seakeeping Committee (2011) in their procedure, 7.5-02 07-02.1 Rev. 4, ITTC - Recommended Procedures and Guidelines: Seakeeping Experiments. This procedure is based on the International Organization for Standardization Guide 98-3, Uncertainty of Measurements - Part 3 (2008). In this paper, the uncertainties in seakeeping analysis are considered, and technical issues regarding the related ITTC procedure for motion responses and loads are introduced. Next, the background of uncertainty analysis in the ITTC procedure 7.5-02 07-02.1 Rev. 4 is described in detail. The types and primary sources of uncertainty in seakeeping analysis are also described, and an appropriate procedure is proposed. Some existing representative studies on uncertainty, which were carried out with respect to seakeeping analysis, are introduced. Furthermore, this paper includes several technical issues with numerical seakeeping and loads analyses. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Experiments; Seakeeping; Ship models; International organization for standardizations; ISO UOM; ITTC procedure; Model testing; Motion response; Primary sources; Uncertainty of measurement; Uncertainty sources; Uncertainty analysis

Population analysis of mesophilic microbial fuel cells fed with carbon monoxide - Hussain, A.; Bruant, G.; Mehta, P.; Raghavan, V.; Tartakovsky, B.; Guiot, S.R. (Applied Biochemistry and Biotechnology, 2014)
Electricity generation in a microbial fuel cell (MFC) fed with carbon monoxide (CO) has been recently demonstrated; however, the microbial ecology of this system has not yet been described. In this work the diversity of the microbial community present at the anode of CO-fed MFCs was studied by performing denaturing gradient gel electrophoresis (DGGE) and high-throughput sequencing (HTS) analyses. HTS indicated a significant increase of the archaeal genus Methanobacterium and of the bacterial order Clostridiales, notably including Clostridium species, while in both MFCs DGGE identified members of the bacterial genera Geobacter, Desulfovibrio, and Clostridium, and of the archaeal genera Methanobacterium, Methanofollis, and Methanosaeta. In particular, the presence of Geobacter sulfurreducens was identified. Tolerance of G. sulfurreducens to CO was confirmed by growing G. sulfurreducens with acetate under a 100 % CO atmosphere. This observation, along with the identification of acetogens, supports the hypothesis of the two-step process in which CO is converted to acetate by the carboxidotrophic Bacteria and acetate is then oxidized by CO-tolerant electricigenic Bacteria to produce electricity. © 2013 Her Majesty the Queen in Right of Canada.

Enhancing multimodality functional and molecular imaging using glucose-coated gold nanoparticles - Feng, G.; Kong, B.; Xing, J.; Chen, J. (Clinical Radiology, 2014)
Aim: To describe how pegylated glucose-coated gold nanoparticles (PEG-Glu-GNPs) can help improve computed tomography (CT) imaging. Materials and methods: PEG-Glu-GNPs were designed for use as an imaging nanoprobe to act an effective contrast agent for both CT and PET scans. Twelve BALB/c mice were divided into two groups: mice with injected with PEG-Glu-GNPs and control mice. The mice were examined using high-resolution micro-CT at different time intervals (24 h, 7 days, and 15 days) after the injection of the particles. Greyscale density and CT attenuation values were determined to trace the excretion of the particles over time. Results: Tumour contours were easily distinguished from surrounding tissue in mice injected with PEG-Glu-GNPs but not controls. This distinction was still visible at 7 days, but not at 15 days post-injection. Conclusion: Molecular imaging technology has enabled the development of a new generation of imaging probes. These sophisticated probes can visualize biological processes or enable early diagnosis of diseases in vivo. Compared to conventional CT images and PET scans, PEG-Glu-GNPs significantly improved image quality at the cellular and molecular level, which can significantly aid the early detection of cancer or cancer metastases. © 2014 The Royal College of Radiologists.

Study on the pre-ignition temperature variations of wire insulation under overload conditions in microgravity by the functional simulation method - Wang, K.; Wang, B.; Kong, W.; Liu, F. (Journal of Fire Sciences, 2014)
A functional simulation method was applied to study the pre-ignition temperature variations of wire insulation under overload conditions in normal gravity. A simplified heating mode was proposed to theoretically investigate the wire heating process. Results of the temperature variations of wire insulation prior to ignition in normal gravity, but under reduced pressures, were obtained and compared with microgravity experimental results in order to investigate the effects of pressure and current on the pre-ignition thermal features of the wire insulation. Results show that the functional simulation method was effective to simulate the natural convection heat transfer effect on the wire insulation, which is a useful alternative approach to predict the pre-ignition thermal features of wire insulation by overload over a long duration in a microgravity environment. © The Author(s) 2013.
Keywords: Ignition; Microgravity; Microgravity processing; Temperature distribution; Wire; Functional simulations; Microgravity environments; Overload condition; Temperature variation; Thermal features; weak buoyant environment; Wire insulation; Wire-heating process; Thermal insulation

Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4: An efficient synthesis of multi-substituted perhydrofuro[2,3-b]furans and perhydrofuro[2,3-b]pyrans - Ma, X.; Zhang, J.; Tang, Q.; Ke, J.; Zou, W.; Shao, H. (Chemical Communications, 2014)
Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4 is described. The method offers multi-substituted perhydrofuro[2,3-b]furans (bis-THFs) and perhydrofuro[2,3-b] pyrans containing a quaternary carbon chiral center in good to excellent yields. © 2014 The Royal Society of Chemistry.
Keywords: carbohydrate derivative; cyclopropane derivative; furo[2,3 b]furan derivative; ketone derivative; pyran derivative; tin chloride; article; catalysis; chirality; cycloaddition; quantum yield; reaction analysis; stereochemistry; synthesis

Evaluating the flow stress of aerospace alloys for tube hydroforming process by free expansion testing - Saboori, M.; Champliaud, H.; Gholipour, J.; Gakwaya, A.; Savoie, J.; Wanjara, P. (International Journal of Advanced Manufacturing Technology, 2014)
In order to obtain accurate tube hydroforming (THF) simulation results, one of the important inputs in the finite element model (FEM) of the process is the mechanical response of the material during THF. Generally, the mechanical response is defined by the stress-strain behavior that can be determined from tensile testing of the specimens extracted either from the sheet used for roll forming of the tubes or directly from the tubes. More recently, free expansion testing has been used to characterize the mechanical response of the material for hydroforming applications. The free expansion test can emulate process conditions similar to those found during THF, and as such, can be used to obtain reliable and accurate information on the mechanical response/properties of the tubular material. The aim of this research is to present an approach for evaluating the stress-strain behavior of different materials using a 3D deformation measurement system in conjunction with an analytical model. Here, to characterize the mechanical response of the materials, free expansion and tensile testing were used for austenitic stainless steel types 321 (SS 321) and 304L (SS 304L), INCONEL® alloy 718 (IN 718), and aluminum alloy 6061 in the annealed "0" temper condition (AA 6061-0). The mechanical response of each material, measured through free expansion testing of tubular forms, was compared to the respective stress-strain behavior determined from the uniaxial tensile test using ASTM E8 geometry specimens extracted from the tubes. For each material studied in this work, the two flow stress behaviors were distinct, indicating that the test method can have a noticeable effect on the mechanical response. Finite element analysis (FEA) of the free expansion of each material was also utilized to simulate the THF process with the flow stress curves obtained experimentally; the predicted expansion and burst pressure results were close to the experimental data indicating that the approach developed and described in this work has merit for characterizing the mechanical response of aerospace alloys for hydroforming applications. © 2014 Her Majesty the Queen in Right of Canada.
Keywords: Aluminum alloys; Austenitic stainless steel; Characterization; Finite element method; Materials testing apparatus; Metal forming; Plastic flow; Tensile testing; Tubes (components); 3D deformation measurements; Finite element simulations; Flow stress behavior; Material characterizations; Stress-strain behaviors; Tube hydroforming; Tube hydroforming process; Uniaxial tensile test; Materials properties

Numerical and experimental study of preforming stage in tube hydroforming - Farimani, S.M.; Gholipour, J.; Champliaud, H.; Savoie, J.; Wanjara, P. (Key Engineering Materials, 2014)
The preforming stage in hydroforming of an aerospace generic shape was investigated using a combination of experimentation and numerical modeling. The preform die was manufactured using a rapid prototyping method, namely the selective laser sintering (SLS) process. The preforming experiments were conducted on 0.9 mm and 1.2 mm thick stainless steel 321 (SS321) tubes. To evaluate the preforming process, an automated deformation measurement system, ARGUS®, was used to measure the 3-dimensional (3D) strains on the deformed tubes. Data collected from the experiments were used to validate the simulation of the preforming stage. The simulation and experimental results were found to be in good agreement, indicating that the preform model can be used as a starting point for simulating the tube hydroforming (THF) process. In addition, the SLS approach was found to be very promising, as it reduced greatly the lead time and cost of process development for THF. © 2014 Trans Tech Publications, Switzerland.
Keywords: Computer simulation; Experiments; Finite element method; Laser heating; Tubes (components); Unattended sensors; Aerospace alloys; Deformation measurements; Generic shapes; Numerical and experimental study; Preforming process; Process development; Selective laser sintering; Tube hydroforming; Preforming

Hybrid laser-arc welding of AA6061-T6 butt joints - Wanjara, Priti; Cao, Xinjin (Advanced Materials Research, 2014)
Hybrid laser-arc welding (HLAW) of butt joints in 3.18 mm thick aluminum alloy (AA) 6061-T6 sheets was investigated in the present study. Under optimized process conditions, high integrity welds with approximately 2% shrinkage and gas porosity were obtained. The weld bead geometry was determined to conform to the crown and root reinforcement specifications for welded aluminum construction - CSA W 59.2 M1191. Softening in the heat-affected zone (HAZ) and fusion zone (FZ) of the welds was observed, the former due to grain coarsening and the latter due to the dissolution of the hardening precipitates as well as the dilution from the application of the ER 5356 filler wire. Under optimized process conditions, the gap tolerance was determined to be 0.5 mm, beyond which the performance of the joints during bend testing was compromised.
Keywords: Butt welding; Electric arc welding; Heat affected zone; 6061; Aluminum construction; Butt joints; Hardening precipitates; Hybrid laser-arc welding; Optimized process; Root reinforcement; Weld bead geometry; Aluminum alloys

Photosintering and electrical performance of CuO nanoparticle inks - Paquet, C.; James, R.; Kell, A.J.; Mozenson, O.; Ferrigno, J.; Lafrenière, S.; Malenfant, P.R.L. (Organic Electronics: physics, materials, applications, 2014)
A copper oxide (CuO) nanoparticle ink was inkjet printed and photosintered in order to optimize electrical performance as a function of pattern dimension. For a given photosintering condition, electrical conductance varied strongly with line widths, ranging from 100 to 300 μm, illustrating the implications of printing and sintering complex circuit designs with varying feature sizes. By tuning the time delay between printing and sintering, exposure wavelength, radiant energy, pulse width and the distance between the light-source and substrate, photosintering conditions were optimized so that variations in sheet resistance for different line widths were minimized. Using optimized photosintering conditions, a sheet resistance value as low as 150 mΩ/□ (resistivity of 9 μΩ cm) and current carrying capacity of 280 mA for a 300 μm wide trace was achieved. © 2014 Published by Elsevier B.V. All rights reserved.
Keywords: Copper; Nanoparticles; Printing; Sheet resistance; Sintering; Complex circuits; Conductive ink; Copper oxide nanoparticles; CuO nanoparticles; Electrical conductance; Electrical performance; Nanoparticle inks; Photosintering; Ink

Spectral fluorescence measurements - Zwinkels, J.C.; DeRose, P.C.; Leland, J.E. (Experimental Methods in the Physical Sciences, 2014)
This chapter covers the topic of spectral fluorescence measurements. These fluorescence measurements offer significant advantages in terms of sensitivity and selectivity, finding wide use in a range of applications in analytical and color technologies. The accurate measurement of fluorescent optical quantities, such as spectral excitation and emission curves and quantum yields, has become increasingly important because of the increasing use of fluorescent materials in manufacturing for enhancing appearance, for example, whiteness, brightness, colorfulness, and conspicuity, and for bioanalytical applications, for example, medical diagnostics. Conventional spectrophotometric instrumentation and procedures may not give meaningful results because the measured spectral fluorescence data will not only depend on the intrinsic optical properties of the fluorescent sample but are also strongly influenced by the instrument characteristics and its interaction with the sample and its environment. The extent of this distortion depends on the details of the instrument design, including its spectral, geometric, polarization, and temporal characteristics, and on the characteristics of the sample itself. This chapter discusses these basic principles, specialized terminology and instrumentation, and experimental calibration and measurement procedures that are used for reliable and accurate measurements of fluorescent materials. This includes a description of both one- and two-monochromator methods. © 2014 Elsevier Inc.

Correlation between dynamic mechanical thermo-analysis and composition-based models for C-S-H in hydrated portland cement paste - Pourbeik, P.; Beaudoin, J.J.; Alizadeh, R.; Raki, L. (Materials and Structures, 2014)
A dynamic mechanical analysis (DMTA) technique was used to assess the mechanical performance of 1.4 nm tobermorite (T), jennite (J) and mixtures of tobermorite and jennite and tobermorite and calcium hydroxide (CH). A comparison of E′ (storage modulus) and tan∂ (internal friction) versus temperature curves for compacted solid bodies of these mineral systems with corresponding curves for cement paste hydrated for 2 month and 3 years (both referred to as 'young') and 45-year-old paste (referred to as 'old') was made. Original data was provided to assess the practical validity of the Richardson-Groves composition-based models for the C-S-H in cement paste. Differences in mechanical performance between the 'young' paste and the 'old' paste could be accounted for by application of a T/J dominant model ('young' paste) and a J-T/CH structural model with a minor amount of T ('old paste'). © 2014 RILEM.

Theoretical concepts in spectrophotometric measurements - Germer, T.A.; Zwinkels, J.C.; Tsai, B.K. (Experimental Methods in the Physical Sciences, 2014)
This chapter will describe some of the theoretical concepts of obtaining optical properties from spectrophotometric measurements. The optical properties of interest can be the spectrophotometric quantities themselves or the calculated optical constants (complex refractive index, absorption, and scattering coefficients). At first, the different radiometric quantities, describing radiance, irradiance, and radiometric intensity will be introduced. The relationships between these quantities and the electromagnetic fields will then be described. Then, the spectrophotometric quantities, such as spectral regular reflectance and transmittance, radiance, irradiance, emittance, diffuse reflectance, diffuse transmittance, and the bidirectional reflectance distribution function will be defined. The Kirchhoff relationship between the reflectance and emittance will be derived. A review of the Fresnel relations will be given, including expressions appropriate for thin films and thick films. Finally, three models for light scattering will be reviewed, including the theory of Kubelka and Munk, important for measuring highly diffuse, volume scattering materials for color formulation applications, scattering from rough surfaces in the facet approximation, useful for very rough surfaces, and vector first-order perturbation theory, useful for smooth surfaces. © 2014 Elsevier Inc.

The molecular structure of a phosphatidylserine bilayer determined by scattering and molecular dynamics simulations - Pan, J.; Cheng, X.; Monticelli, L.; Heberle, F.A.; Kučerka, N.; Tieleman, D.P.; Katsaras, J. (Soft Matter, 2014)
Phosphatidylserine (PS) lipids play essential roles in biological processes, including enzyme activation and apoptosis. We report on the molecular structure and atomic scale interactions of a fluid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS). A scattering density profile model, aided by molecular dynamics (MD) simulations, was developed to jointly refine different contrast small-angle neutron and X-ray scattering data, which yielded a lipid area of 62.7 Å2 at 25 °C. MD simulations with POPS lipid area constrained at different values were also performed using all-atom and aliphatic united-atom models. The optimal simulated bilayer was obtained using a model-free comparison approach. Examination of the simulated bilayer, which agrees best with the experimental scattering data, reveals a preferential interaction between Na+ ions and the terminal serine and phosphate moieties. Long-range inter-lipid interactions were identified, primarily between the positively charged ammonium, and the negatively charged carboxylic and phosphate oxygens. The area compressibility modulus KA of the POPS bilayer was derived by quantifying lipid area as a function of surface tension from area-constrained MD simulations. It was found that POPS bilayers possess a much larger K A than that of neutral phosphatidylcholine lipid bilayers. We propose that the unique molecular features of POPS bilayers may play an important role in certain physiological functions. This journal is © the Partner Organisations 2014.
Keywords: Amino acids; Atoms; Cell death; Lipid bilayers; Molecular dynamics; Molecular structure; Scattering; Area compressibility; Atomic-scale interaction; Molecular dynamics simulations; Phosphatidylcholine; Phosphatidylserine; Physiological functions; Preferential interaction; United-atom models; Computer simulation

Accurate, precise and direct determination of dissolved phosphate and silicate in seawater by IEC SF-ICPMS - Yang, L.; Pagliano, E.; Mester, Z. (Analytical Chemistry, 2014)
A method is described for the direct determination of dissolved phosphate and silicate in seawater using ion exclusion chromatography (IEC) coupled with sector field inductively coupled plasma mass spectrometry (SF-ICPMS). Dissolved silicate was determined by double isotope dilution using a 29Si spike, whereas one point gravimetric standard addition with internal standard of the same 29Si spike was employed to quantitate dissolved phosphate. Medium resolution was used for all measurements in order to resolve polyatomic interferences on Si and P isotopes. Concentrations of 1.670 ± 0.008 and 30.20 ± 0.09 μM (SD, n = 6) with precisions of 0.47 and 0.31% for the dissolved phosphate and silicate, respectively, were obtained in National Research Council Canada certified reference material MOOS-3 seawater, in good agreement with certified values of 1.60 ± 0.15 and 30.5 ± 0.8 μM (U, k = 2), respectively. The reported method is a rapid (10 min per run), simple, and accurate online technique that requires no sample pretreatment. Moreover, this procedure achieves <0.5% precision (at above analyte concentrations) and method detection limits of 0.006 and 0.004 μM (0.18 as P and 0.11 ng g-1 as Si), respectively, using a of 100 μL injection of seawater. The proposed technique is robust and well-suited for the determination of dissolved phosphate and silicate in seawater. © Published 2014 by the American Chemical Society.
Keywords: Chromatography; Inductively coupled plasma mass spectrometry; Ion chromatography; Isotopes; Seawater; Silicates; Silicon; Analyte concentration; Certified reference materials; Dissolved phosphates; Ion exclusion chromatographies; Method detection limits; National Research Council; Polyatomic interferences; Sector field inductively coupled plasma mass spectrometries; Dissolution

Simulation of reactive spraying deposition technology for fabricating fuel cell catalyst layer - Hu, G.-L.; Neagu, R.; Wang, Q.-P.; Li, G.-N.; Zhang, Z.-G.; Zheng, Y.-Q. (工程热物理学报, 2014)
The reactive spraying deposition technology is a new catalyst layer fabrication technology for producing nanometer particle and spraying the catalyst layer with steady performance. A three-dimensional comprehensive mathematical model of flow and heat/mass transfer coupling with chemical reactions for fuel gas and droplet combustion during reactive spraying deposition technology (RSDT) is presented in this paper to theoretically study complex physical and chemical processes during RSDT. The RNG k -ε model is employed to describe turbulent combustion gas flow. The droplet particle is tracked and analyzed in a Lagrangian frame. The Monte Carlo method is used to simulate the growth of surface structure of the catalyst layer. The computational results can be used to provide some reference for optimization of this technology.
Keywords: Monte Carlo method; Multi-species reaction; Numerical simulation; Reactive spraying deposition technology (RSDT); RNG k-ε model; Computational results; Deposition technology; Droplet combustion; Fabrication Technologies; Fuel-cell catalyst layers; Nanometer particles; Turbulent

Real-time diagnosing polymer extruding behaviour during rheometer processing(II) - Zhao, Lijuan; Zhong, Qin; Zhuang, Hongjun; Sun, Zhigang (高分子材料科学与工程, 2014)
Ultrasonic, temperature and pressure sensors were combined together to be used in a slit rheometer to investigate the relationship between ultrasound signals with the rheological properties of PP and PS in processing. It is found that ultrasonic signals can represent monotone changes of polymer relaxation for different polymers under different processing conditions, and it also can indicate the shear thinning of polymer melting. Under the certain processing condition, there is an exponential relationship between ultrasonic signals with the viscosity of polymers, while the former factor and index number increase with the temperature increasing. Maxwell equations were used to simulate the relaxation of polymers in slit die, and it is found that two parallel connections Maxwell can fit the relaxation process well. This work can be used to investigate the viscoelasticity of polymers during rheometer processing.
Keywords: In-line diagnosis; Maxwell equations; Rheology; Ultrasound

Storing GHz bandwidth heralded single photons in a room-temperature Raman memory : efficiency and noise - Nunn, Joshua; Michelberger, Patrick S.; Chamption, Tessa F.; Sprague, Michael R.; Kaczmarek, Krzysztof; Saunders, Dylan J.; Kolthammer, Steven W.; Jin, Xian-Min; England, Duncan G.; Walmsley, Ian A. (Conference Paper: Quantum Information and Measurement: Quantum Memories (QTu2B), 2014)
We store GHz-bandwidth heralded single photons in a room-temperature Raman memory, which is a crucial primitive for scalable quantum photonics. We discuss methods to suppress four-wave mixing noise, which accompanies the retrieved photons.

One-magnon and exciton inelastic light scattering in the antiferromagnet CoF2 - Meloche, E.; Cottam, M. G.; Lockwood, D. J. (Low Temperature Physics, 2014)
Experimental data are reported for the temperature and polarization dependence of the one-magnon Raman light scattering in the rutile-structure antiferromagnet CoF₂ (Neel temperature TN = 38 K). The low-lying excitons are also investigated at low temperatures and comparisons made with results from earlier Raman, infrared, and neutron scattering work. A detailed analysis of the one-magnon Stokes and anti-Stokes Raman spectra is presented resulting in comprehensive data for the temperature variation up to TN of the one-magnon frequency, line width, and integrated intensity. A theory of the one-magnon scattering and other magnetic transitions is constructed based mainly on a spin S = 3/2 exchange model, extending a simpler effective S = 1/2 approach. The excitation energies and spectral intensities over a broad range of temperatures are obtained using a Green's function equation of motion method that allows for a careful treatment of the single-ion anisotropy. Overall the S = 3/2 theory compares well with the experimental data.

Multimodal nonlinear optical microscopy : from biophotonics to geophotonics - Andreana, Marco; Stolow, Albert (Optics and Photonics News, 2014)
Nonlinear optical spectroscopies such as CARS and SRS offer rapid, label-free, chemical-specific imaging. And the ability to simultaneously deploy multiple modes of nonlinear imaging on a single sample is creating some striking new views of natural materials.

Rotating electrode methods and oxygen reduction electrocatalysts - Xing, Wei; Yin, Geping; Zhang, Jiujun (Elsevier B.V., 2014)
Rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) techniques are one kind of the important and commonly used methods in electrochemical science and technology, particularly, in the fundamental understanding of electrochemical catalytic reaction mechanisms such as electrocatalytic oxygen reduction reaction (ORR). The kinetics and mechanisms of ORR catalyzed by both noble metal- and nonnoble metal-based electrocatalysts are the most important aspects in fuel cell and other ORR-related electrochemical technologies. Using RDE and RRDE to evaluate the activities of catalysts and their catalyzed ORR mechanisms is necessary and also one of the most feasible approaches in the development of ORR electrocatalysts.
Keywords: Rotating disk electrode techniques; rotating ring-disk electrode techniques; oxygen reduction electrocatalysts

Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel - Lévesque, D.; Rousseau, G.; Wanjara, P.; Cao, X.; Monchalin, J.-P. (40th Review of Progress in Quantitative Nondestructive Evaluation: Incorporating the 10th International Conference on Barkhausen Noise and Micromagnetic Testing, 2014)
The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

Intrinsically microporous soluble polyimides incorporating Tröger’s Basefor membrane gas separation - Zhuang, Yongbing; Seong, Jong Geun; Do, Yu Seong; Jo, Hye Jin; Cui, Zhaoliang; Lee, Jongmyeong; Lee, Young Moo; Guiver, Michael D. (Macromolecules, 2014)
Polyimides with intrinsic microporosity were readily prepared by introducing Tröger’s base (TB) into the polymer backbone via polymerization between imide-containing diamines and dimethoxymethane (DMM). Two imide-containing diamines were prepared by reaction of 2,5-dimethyl-1,4-phenylenediamine (DPD) with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA). The resulting polyimides were readily soluble in common organic solvents, had good mechanical properties, with tensile strength in the range of 59–64 MPa and elongation at break of 5–17%, good thermal stability and extremely high glass transition temperatures (Tgs), up to 425 °C. The polyimides with incorporated TB units had high fractional free volume (FFV ≥ 0.215) resulting from poor chain-packing and exhibited significant microporosity and good gas transport properties. The novel polymer architecture in this study extends the development of polyimides with intrinsic microporosity for membrane-based gas separation.

Specific inhibitors for identifying pathways for methane production from carbon monoxide by a nonadapted anaerobic mixed culture - Navarro, Silvia Sancho; Cimpoia, Ruxandra; Bruant, Guillaume; Guiot, Serge R. (Canadian Journal of Microbiology, 2014)
Specific inhibitors such as 2-bromoethanesulfonate (BES) and vancomycin were employed in activity batch tests to decipher metabolic pathways that are preferentially used by a mixed anaerobic consortium (sludge from an anaerobic digester) to transform carbon monoxide (CO) into methane (CH₄). We first evaluated the inhibitory effect of both BES and vancomycin on the microbial community, as well as the efficiency and stability of vancomycin at 35 °C, over time. The activity tests with CO₂–H₂, CO, glucose, acetate, formate, propionate, butyrate, methanol, and ethanol showed that vancomycin does not inhibit some Gram-negative bacteria, and 50 mmol/L BES effectively blocks CH₄ production in the sludge. However, when sludge was incubated with propionate, butyrate, methanol, or ethanol as the sole energy and carbon source, methanogenesis was only partially inhibited by BES. Separate tests showed that 0.07 mmol/L vancomycin is enough to maintain its inhibitory efficiency and stability in the population for at least 32 days at 35 °C. Using the inhibitors above, it was demonstrated that CO conversion to CH₄ is an indirect, 2-step process, in which the CO is converted first to acetate and subsequently to CH₄.
Keywords: carbon monoxide, anaerobic, methanation, methanogenesis, carboxydotrophy, bromoethanesulfonate (BES), vancomycin

Ion transport by nanochannels in ion-containing aromatic copolymers - Li, Nanwen; Guiver, Michael D. (Macromolecules, 2014)
The search for the next generation of highly ion-conducting polymer electrolyte membranes has been a subject of intense research because of their potential applications in energy storage and transformation devices, such as fuel cells, vanadium flow batteries, membrane-based artificial photosynthesis, water electrolysis, or water treatment processes such as electrodialysis desalination. Nanochannels that contain ionic groups, through which “hydrated” ions can pass, are believed to be of key importance for efficient ion transport in polymer electrolytes membranes. In this Perspective, we present an overview of the approaches to induce ion-conducting nanochannel formation by self-assembly, using polymer architecture such as block or comb-shaped copolymers. The transport properties of ion-containing aromatic copolymers are examined to obtain an insight into the fundamental behavior of these materials, which are targeted toward applications in fuel cells and other electrochemical devices. Challenges in obtaining well-defined nanochannel morphologies, and possible strategies to improve transport properties in aromatic copolymers having structures with the potential to withstand operation in electrochemical/chemical devices, are discussed. Opportunities for the application of ion-containing aromatic copolymer membranes in fuel cells, vanadium flow batteries, membrane-based artificial photosynthesis, electrolysis, and electrodialysis are also reviewed. Research needs for further improvements in ionic conductivity and durability, and their applications are identified.

Alternative coating technologies for metal-ceramic nanocomposite films : potential application for solar thermal absorber - Bensebaa, F.; Di Domenicantonio, D.; Scoles, L.; Kingston, D.; Mercier, P.; Marshall, G. (International Journal of Low-Carbon Technologies, 2014)
Metal-ceramic nanocomposite films for solar absorbers have been obtained by electro-deposition technique. This coating technique uses a mixed solution of nickel nanoparticles and sub-micron alumina particles. The relative ration of Ni-to-Al in these films is varied by tuning the concentration of nickel and alumina particles in the starting solution. Three films with different Ni/Al ratios have been prepared and characterized with X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Even in absence of any heat treatment, significant amounts of nickel in a metallic state have been found in all three samples.
Keywords: electrodeposition; nanoparticle; coating; metal; solar

Mixed gas sorption in glassy polymeric membranes: II. CO2/CH4 mixtures in a polymer of intrinsic microporosity (PIM-1) - Vopička, Ondřej; De Angelis, Maria Grazia; Du, Naiying; Li, Nanwen; Guiver, Michael D.; Sarti, Giulio Cesare (Journal of Membrane Science, 2014)
The individual solubility of CH4 and CO2 from binary gas mixtures was measured at 35 °C and up to 35 bar in a polymer of intrinsic microporosity (PIM-1), at different compositions of the gas phase (from 0 to 50 mol% of CO2). The experiments were conducted on a pressure-decay apparatus equipped with a gas chromatograph, allowing a highly flexible measuring procedure. The gas solubility was plotted versus gas phase composition, total pressure, gas fugacity and second gas concentration. The mixed gas solubility of both species, CH4 and CO2, is lower than the pure gas value at the same fugacity, but the reduction of methane solubility due to the presence of CO2 is generally more significant. Such behavior is due to the fact that CO2 has normally higher solubility than methane: indeed the depression of the solubility coefficient with respect to the pure gas value is similar for both gases, when reported at the same concentration of the second gas. The real, mixed gas solubility selectivity is in general higher than the ideal value calculated from pure gas behavior. The ratio between real and ideal solubility selectivity increases with CO2 concentration in the membrane, according to a single mastercurve, reaching a maximum value of 4, and it also increases with the ratio between CO2 and CH4 concentration in the membrane. In particular, as in the case of other glassy polymers, the real solubility selectivity of CO2 over CH4 is higher than the ideal value if c(CO2)>c(CH4), and it is lower than the ideal value if the opposite condition holds true. Such behavior occurs because the competition for sorption is normally less effective on the more abundant penetrant in the polymer. A selectivity–solubility performance plot can be drawn for this system.
Keywords: intrinsic microporosity; gas transport; solubility; mixed gas

Superhydrophobicity and water repelling characteristics of thermally sprayed titanium dioxide - Sharifi, N.; Ettouil, Ben F.; Mousavi, M.; Pugh, M.; Dolatabadi, A.; Moreau, C. (Journal of thermal spray technology, 2014)
The wetting behavior (hydrophobicity/hydrophilicity) of atmospheric plasma sprayed (APS) and suspension plasma sprayed (SPS) TiO2 coatings was investigated. The effect of different spraying process parameters on the water contact angle (WCA) of these coatings was studied using a Taguchi method for design of experiments. It was found that by controlling the spraying parameters, coatings can be developed with WCAs as high as 140° despite the natural hydrophilicity of TiO2. SEM imaging showed that these coatings have a hierarchical (dual scale) roughness that provides the hydrophobicity of their surface by enhancing water repellency and mobility on the surface.

Characterization of an oleate 12-desaturase from Physaria fendleri and identification of 5′UTR introns in divergent FAD2 family genes - Lozinsky, Sharla; Yang, Hui; Forseille, Li; Cook, Gillian R.; Ramirez-erosa, Irving; Smith, Mark A. (Plant Physiology and Biochemistry, 2014)
Mining of an EST sequence collection representing genes expressed during seed development in Physaria fendleri identified abundant sequences encoding apparent homologues of the Arabidopsis oleate 12-desaturase (AtFAD2 At3g12120). Of the 62 sequenced clones, 59 were identified as encoding the previously characterized bifunctional oleate 12-hydroxylase/desaturase (LFAH12/PfFAH12). The remaining 3 clones encoded a second FAD2 homologue. Isolation of a full length ORF and heterologous expression in yeast revealed that this sequence, designated PfFAD2, is the first full length sequence from any Physaria species that encodes an oleate 12-desaturase. PfFAD2 was expressed in both leaf and developing seed with activity on palmitate (16:1δ9) and oleate (18:1δ9). Sequence comparison revealed that PfFAD2 shares 93% amino acid identity with Arabidopsis FAD2 and only 84% identity with PfFAH12. By comparison of EST and genomic sequences it was revealed that the PfFAD2 gene encodes a transcript with a single intron of 1120bp in the 5'-untranslated region (5'UTR). A short intron, 81bp in length, was also discovered in the 5'UTR of the PfFAH12 gene, 16bp upstream of the translation initiation codon. In silico examination of FAD2 like genes from the genome of castor (Ricinus communis) identified putative 5'UTR introns in genes encoding the castor oleate 12-desaturase (RcFAD2) and oleate 12-hydroxylase (CFAH12). By sequencing of genomic DNA the presence of single 5'UTR introns in each gene, and the size of these introns, was confirmed. These findings suggest that 5'UTR introns may be a characteristic feature of FAD2 genes and also of divergent FAD2 genes encoding fatty acid modifying enzymes, and that the selection pressure maintaining these introns is very different.
Keywords: FAD2; Fatty acid desaturase; Fatty acid hydroxylase; Lesquerella5'UTR intron; Physaria fendleri

Lymphadenopathy: what defines a palpable lymph node? - Xu, Jason J.; Campbell, Gordon; Alsaffar, Hussain; Brandt, Michael G.; Doyle, Philip C.; Glicksman, Jordan T.; Fung, Kevin (Head & Neck, 2014)
BACKGROUND: The threshold size required to detect lymphadenopathy via palpation has never been formally determined. The purpose of this study was to determine the threshold, sensitivity, and error of node palpation and how this changes with experience. METHODS: Lymphadenopathy models were created using polyvinyl alcohol cryogel (PVA-C) to mimic tissue tactility. Node diameter ranged from 0.5 to 4 cm. Study subjects were medical students, otolaryngology residents, and otolaryngology consultants. Each subject provided 22 estimates of size. Primary outcomes were the sensitivity, error (true vs estimated size), and threshold of palpation. RESULTS: Thirty subjects completed the study. Sensitivity was 60%, 74%, and 86% for students, residents, and consultants, respectively (p < .01). Error was 0.88 cm, 0.61 cm, and 0.57 cm, respectively (p < .05). Palpation threshold was 1.32 cm, 0.83 cm, and 0.75 cm, respectively (p < .05). All participants detected nodes ≥2 cm, whereas consultants detected nodes ≥1 cm.
Keywords: physical examination; lymph node palpation; medical education; simulation

Third body behavior during dry sliding of cold-sprayed Al-Al₂O₃ composites : in situ tribometry and microanalysis - Shockley, J. Michael; Descartes, S.; Irissou, É.; Legoux, J.-G.; Chromik, R. R. (Tribology Letters, 2014)
Reciprocating sliding wear experiments were conducted on cold-sprayed pure aluminum and Al–22.6 wt% Al2O3 coatings using a custom-built in situ tribometer. Using a transparent sapphire counterface for the wear tests, the dynamic behavior of third body material in the contact was optically observed. The presence of Al2O3 particles led to greater stability of the transfer films adhering to the sapphire counterface, as well as greater stability of the friction coefficient and lower wear rates. Ex situ microanalysis of material in the wear tracks and transfer films suggests that the presence of Al2O3 particles promoted strain localization during sliding. This produced more uniform third body microstructures and protected the underlying aluminum matrix from deformation, which slowed the rate of transfer to the counterface.
Keywords: Cold spray; aluminum composite; third bodies; in situ tribometry; tribological circuit.

Effect of heat treatment on the microstructure and mechanical properties of stainless steel 316L coatings produced by cold spray for biomedical applications - AL-Mangour, Bandar; Vo, Phuong; Mongrain, Rosaire; Irissou, Éric; Yue, Stephen (Journal of Thermal Spray Technology, 2014)
In this study, the effects of heat treatment on the microstructure and mechanical properties of cold sprayed stainless steel 316L coatings using N2 and He as propellant gases were investigated. Powder and coating characterizations, including coating microhardness, coating porosity, and XRD phase analysis were performed. It was found that heat treatment reduced porosity, improved inter-particle bonding, and increased ductility. XRD results confirmed that no phase transformation occurred during deposition. Significant increase in UTS and ductility was observed for the annealed specimens obtained with nitrogen propellant, whereas little changes were observed for the helium propellant produced specimen.
Keywords: cold gas dynamic spray; fractography; inter-particle bonding; mechanical properties; stent

ESPRESSO: The next European exoplanet hunter - Pepe, F.; Molaro, P.; Cristiani, S.; Rebolo, R.; Santos, N.C.; Dekker, H.; Mégevand, D.; Zerbi, F. M.; Cabral, A.; Di Marcantonio, P.; Abreu, M.; Affolter, M.; et al. (Astronomische Nachrichten, 2014)
The acronym ESPRESSO stems for Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations; this instrument will be the next VLT high resolution spectrograph. The spectrograph will be installed at the Combined-Coudé Laboratory of the VLT and linked to the four 8.2 m Unit Telescopes (UT) through four optical Coudé trains. ESPRESSO will combine efficiency and extreme spectroscopic precision. ESPRESSO is foreseen to achieve a gain of two magnitudes with respect to its predecessor HARPS, and to improve the instrumental radial-velocity precision to reach the 10 cm s-1 level. It can be operated either with a single UT or with up to four UTs, enabling an additional gain in the latter mode. The incoherent combination of four telescopes and the extreme precision requirements called for many innovative design solutions while ensuring the technical heritage of the successful HARPS experience. ESPRESSO will allow to explore new frontiers in most domains of astro-physics that require precision and sensitivity. The main scientific drivers are the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby G to M-dwarfs and the analysis of the variability of fundamental physical constants. The project passed the final design review in May 2013 and entered the manufacturing phase. ESPRESSO will be installed at the Paranal Observatory in 2016 and its operation is planned to start by the end of the same year.