bluuebunny/crossref_metadata_2025 huggingface dataset:
Curcumin inspired synthesis of unsymmetrical diarylpentanoids with highly potent anti-parasitic activities: in silico studies and DFT-based stereochemical calculation
Authors: Din Zia Ud , Santos Alef dos , Trapp Marilia Almeida , Lazarin-Bidóia Danielle , Garcia Francielle Pelegrin , Peron Francieli , Nakamura Celso Vataru , Rodrigues-Filho Edson
Published: January 2016

Unsymmetrical diarylpentanoid analogues of curcumin have been synthesized by Claisen–Schmidt condensation of different aldehydes and ketones.
The removal of organophosphorus pesticides from water using a new amino-substituted calixarene-based magnetic sporopollenin
Authors: Kamboh Muhammad Afzal , Ibrahim Wan Aini Wan , Nodeh Hamid Rashidi , Sanagi Mohd Marsin , Sherazi Syed Tufail Hussain
Published: January 2016

This study describes the synthesis, characterization and application of a new amino-substituted p-tert-butylcalix[4]arene-based magnetic sporopollenin, Calix-EPPTMS-MS (4), for the removal of two toxic organophosphorus pesticides from water.
Tungsten carbide/porous carbon core–shell nanocomposites as a catalyst support for methanol oxidation
Authors: Lang Xiaoling , Shi Meiqin , Jiang Yekun , Chen Huan , Ma Chunan
Published: January 2016

The Pt–WC@C demonstrates higher electrochemical activity, which could be attributed to the better dispersed Pt on WC which leads to the improved synergistic effect between WC and Pt.
Development of composite anion-exchange membranes using poly(vinyl alcohol) and silica precursor for pervaporation separation of water–isopropanol mixtures
Authors: Premakshi H. G. , Kariduraganavar M. Y. , Mitchell G. R.
Published: January 2016

Composite anion-exchange membranes (AEMs) were prepared using sol–gel techniques with poly(vinyl alcohol) and anion-exchange silica precursor (AESP). Among the composite AEMs, the membrane containing 4 mass% of AESP (M-4) exhibited the excellent pervaporation performance.
Temperature-dependent catalytic reduction of 4-nitrophenol based on silver nanoclusters protected by a thermo-responsive copolymer ligand
Authors: Lü Jianhua , Fu Yuqin , Song Yajiao , Wang Dongmei , Lü Changli
Published: January 2016

A facile strategy is developed for fabricating novel nanocatalysts of Ag NCs protected with a temperature-responsive copolymer ligand containing 8-hydroxyquinoline and isopropylacrylamide segments.
Fluoride concentration controlled TiO2nanotubes: the interplay of microstructure and photocatalytic performance
Authors: Wang Xueqin , Li Yanfang , Song Hua , Huang Yudong , Su Ren , Besenbacher Flemming
Published: January 2016

Increasing [F−] of the electrolyte resulted in an increase of both the length and diameter of TiO2NTs, which further improved the photocurrent response and the photodecolorization of RhB.
Facile hydrothermal growth of VO2 nanowire, nanorod and nanosheet arrays as binder free cathode materials for sodium batteries
Authors: Wang Hongkuan , Li Wenzao , Fei Huifang , Guo Liping , Feng Jinkui , Ci Lijie , Xiong Shenglin
Published: January 2016

Owing to the natural abundance and low standard potential of sodium, sodium-ion batteries are now considered to be promising power systems for electric vehicles and stationary energy storage.
The biocompatibility evaluation of iron oxide nanoparticles synthesized by a one pot process for intravenous iron supply
Authors: Li Juanjuan , Liu Yang , Cha Ruitao , Ran Bei , Mou Kaiwen , Wang Huashan , Xie Qian , Sun Jiashu , Jiang Xingyu
Published: January 2016

This paper reports a new synthesis method to control the size of iron oxide nanoparticles (IONs) by adding sodium citrate during fabrication to obtain sodium citrate-modified iron oxide nanoparticles (SCIONs).
Hydrothermal synthesis of a Ba and Mg co-doped Bi12GeO20 photocatalyst with enhanced visible light catalytic activity
Authors: Chen Yi , Fang Jianzhang , Lu Shaoyou , Cen Chaoping , Cheng Cong , Ren Lu , Feng Weihua , Fang Zhanqiang
Published: January 2016

(Ba, Mg)-codoped Bi12GeO20 was successfully synthesized through the one-step hydrothermal method, and the band gap was greatly narrowed.
Synthesis of silicon-doped reduced graphene oxide and its applications in dye-sensitive solar cells and supercapacitors
Authors: Wang Zegao , Chen Yuanfu , Li Pingjian , He Jiarui , Zhang Wanli , Guo Zheng , Li Yanrong , Dong Mingdong
Published: January 2016

The silicon-doped reduced graphene oxide was synthesized via annealing treatment of triphenylsilane and graphene oxide. It exhibits significant enhancement in electrocatalytic and electrochemical properties.
Chain-like Fe3O4@resorcinol-formaldehyde resins–Ag composite microstructures: facile construction and applications in antibacterial and catalytic fields
Authors: Zhong Yiman , Ni Yonghong , Li Shifeng , Wang Meifang
Published: January 2016

Chain-like Fe3O4@RF–Ag microstructures with excellent antibacterial and catalytic activities were constructed by a simple two-step route.
Molecular dynamics simulations for 5,5′-bistetrazole-1,1′-diolate (TKX-50) and its PBXs
Authors: Yu Yuehai , Chen Shusen , Li Xin , Zhu Jiaping , Liang Hui , Zhang Xiaoxin , Shu Qinghai
Published: January 2016

Molecular dynamics has been carried out to study the mechanical properties, moldability, binding energies, and detonation properties of TKX-50 and TKX-50 based polymer bonded explosives (PBXs) with four commonly used polymer binders.
New insights into exciton binding and relaxation from high time resolution ultrafast spectroscopy of CH3NH3PbI3and CH3NH3PbBr3films
Authors: sharma Vinay , Aharon Sigalit , Gdor Itay , Yang Chunfan , Etgar Lioz , Ruhman Sanford
Published: January 2016

High time resolution broadband pump-probe experiments on CH3NH3PbI3and CH3NH3PbBr3films show that interband and exciton transitions are essential to understanding transient spectra, which reflect exciton binding energies of 20–30 meV in both materials.
Bio-inspired sensors based on photonic structures of Morpho butterfly wings: a review
Authors: Li Qingsong , Zeng Qi , Shi Lei , Zhang Xiaohua , Zhang Ke-Qin
Published: January 2016

This review summarizes the state-of-the-art development of Morpho butterfly wings used for various physical and chemical sensors.
Spontaneous generation of interlayers in OPVs with silver cathodes: enhancing Voc and lifetime
Authors: Shamieh B. , Obuchovsky S. , Frey G. L.
Published: January 2016

A major contribution to the performance improvement of organic photovoltaic (OPV) devices is due to the successful engineering of the metal/organic interface by generating interlayers.
Chelation-assisted Pd-catalysed ortho-selective oxidative C–H/C–H cross-coupling of aromatic carboxylic acids with arenes and intramolecular Friedel–Crafts acylation: one-pot formation of fluorenones
Authors: Sun Denan , Li Bijin , Lan Jingbo , Huang Quan , You Jingsong
Published: January 2016

Starting from the readily available substrates, an efficient method for the synthesis of fluorenone derivatives has been developed.
Surprising impact of remote groups on the folding–unfolding and dimer-chain equilibria of bifunctional H-bonding unimers
Authors: Liu Rui , Cheng Shuang , Baker Erin S. , Smith Richard D. , Zeng Xiao Cheng , Gong Bing
Published: January 2016

The remote end groups of aromatic foldamers are found to profoundly impact the assembling propensity of these molecules.
Bulk nanostructure of the prototypical ‘good’ and ‘poor’ solvate ionic liquids [Li(G4)][TFSI] and [Li(G4)][NO3]
Authors: Murphy Thomas , Callear Sam K. , Yepuri Nageshwar , Shimizu Karina , Watanabe Masayoshi , Canongia Lopes José N. , Darwish Tamim , Warr Gregory G. , Atkin Rob
Published: January 2016

The bulk nanostructures of a prototypical ‘good’ solvate ionic liquid (SIL) and ‘poor’ SIL have been examined using neutron diffraction and empirical potential structure refinement (EPSR) simulated fits.
Electron conjugation versus π–π repulsion in substituted benzenes: why the carbon–nitrogen bond in nitrobenzene is longer than in aniline
Authors: Zhang Huaiyu , Jiang Xiaoyu , Wu Wei , Mo Yirong
Published: January 2016

Computations show that the enhanced π–π repulsion in nitrobenzene, contributed by both the electrostatic interaction and the Pauli exchange, is responsible for the stretched C–N bond in nitrobenzene (1.486 Å) compared with the C–N bond in aniline (1.407 Å).
Correction: Phosphorylation of bio-based compounds: the state of the art
Authors: Illy Nicolas , Fache Maxence , Ménard Raphaël , Negrell Claire , Caillol Sylvain , David Ghislain
Published: January 2016

Correction for ‘Phosphorylation of bio-based compounds: the state of the art’ by Nicolas Illy, et al., Polym. Chem., 2015, 6, 6257–6291.
Influence of the electrodeposition potential on the crystallographic structure and effective magnetic easy axis of cobalt nanowires
Authors: Irshad M. I. , Mohamed N. M. , Abdullah M. Z. , Saheed M. S. M. , Mumtaz A. , Yasar M. , Yar A. , Zeeshan M. A. , Sort J.
Published: January 2016

Cobalt nanowires (NWs) have been synthesized by electrodeposition inside the pores of anodized aluminium oxide templates, at different values of applied deposition potential.
Digital realisation of the IEC flickermeter using root mean square of the voltage waveform
Authors: Balouji Ebrahim , Salor Ozgul
Published: January 2016

In this study, a digital realisation of the IEC (International Electrotechnical Committee) flickermeter using root mean square (RMS) of the voltage waveform as its input, instead of the voltage waveform, is presented. The aim of this research work is to compute the flicker severity according to the IEC flickermeter standard, IEC 61000‐4‐15, when only the RMS values of the voltage waveform are available. Hence, a new method is proposed to compute the light flicker directly from half‐cycle‐RMS values of the voltage, which are computed based on the IEC power quality standard, IEC 61000‐4‐30. Beginning from the signal model for a voltage with flicker provided in IEC 61000‐4‐15, the RMS of the voltage waveform is derived in terms of the flicker frequency components and the corresponding amplitudes. It has been shown on simulation data that short‐term flicker severity can be computed by the proposed method with an average error rate of 0.021%. The method has also been applied on field data collected at a transformer substation supplying an electric arc furnace plant, and has been shown to successfully generate flicker severity from RMS voltage waveforms, when compared with the IEC flickermeter results.
Electronic spectra of 2- and 3-tolunitrile in the gas phase. I. A study of methyl group internal rotation via rovibronically resolved spectroscopy
Authors: Ruiz-Santoyo José Arturo , Wilke Josefin , Wilke Martin , Yi John T. , Pratt David W. , Schmitt Michael , Álvarez-Valtierra Leonardo
Published: January 2016

Rotationally resolved fluorescence excitation spectra of the origin bands in the S1←S0 transition of 2-tolunitrile (2TN) and 3-tolunitrile (3TN) have been recorded in the collision-free environment of a molecular beam. Analyses of these data provide the rotational constants of each molecule and the potential energy curves governing the internal rotation of the attached methyl groups in both electronic states. 2TN exhibits much larger barriers along this coordinate than 3TN. Interestingly, the electronic transition dipole moment in both molecules is markedly influenced by the position of the attached methyl group rather than the position of the cyano group; possible reasons for this intriguing behavior are discussed.
Single crystal elastic constants evaluated with surface acoustic waves generated and detected by lasers within polycrystalline steel samples
Authors: Gasteau D. , Chigarev N. , Ducousso-Ganjehi L. , Gusev V. E. , Jenson F. , Calmon P. , Tournat V.
Published: January 2016

We report on a laser generated and detected surface acoustic wave method for evaluating the elastic constants of micro-crystals composing polycrystalline steel. The method is based on the measurement of surface wave velocities in many micro-crystals oriented randomly relative to both the wave propagation direction and the sample surface. The surface wave velocity distribution is obtained experimentally thanks to the scanning potentiality of the method and is then compared to the theoretical one. The inverse problem can then be solved, leading to the determination of three elastic constants of the cubic symmetry micro-crystals. Extensions of the method to the characterization of texture, preferential orientation of micro-crystals or welds could be foreseen.
Molecular anions of polydeprotonated naphthalenes: An investigation on the metastability and deprotonation energies using nuclear-charge stabilization method
Authors: Sangwan Poonam , Vikas
Published: January 2016

The dianions and trianions of doubly- and triply-deprotonated naphthalenes are investigated using density functional theory (DFT) computations employing hybrid, long-range, and dispersion corrected exchange-correlation functionals. The investigated polyanionic species are found to be metastable with negative electron affinity and are further treated using a nuclear-charge stabilization method. The tunneling lifetimes of these anionic species were estimated to be a few femtoseconds. Notably, the deprotonated energies (DPEs) of naphthalene leading to the formation of triply deprotonated trianions are observed to be affected by the metastability of the dianions and trianions. For the deprotonation of doubly deprotonated dianions, the DPE calculated using the improved methodology based on the stabilization method is found to be nearly 100 kcal/mol more than that computed using the conventional procedure. Though the various DFT approximations employed are in a good agreement for predicting the lifetimes of the metastable species but in the prediction of electron-affinities and deprotonation energies, the dispersion-corrected DFT-D3 significantly disagrees with the long-range corrected DFT methods employing cam-B3LYP and ωB97XD exchange-correlation functionals.
Polymerization of defect states at dislocation cores in InAs
Authors: Park Ji-Sang , Kang Joongoo , Yang Ji-Hui , McMahon W. E. , Wei Su-Huai
Published: January 2016

Dislocations are essentially lines of point defects which can act as recombination centers in semiconductor devices. These point defects do not behave as isolated defects. Their spatial proximity enables them to hybridize into a one-dimensional band, and the distribution of resulting defect-band states is determined by both the position of the band and its dispersion. In the case of glissile 90° partial dislocations in III-V semiconductors, the dislocation core can adopt a variety of different reconstructions. Each of these reconstructions has a different arrangement of point defects, which affects the hybridization into defect bands and their associated dispersion. Here, we illustrate these principles by performing first-principles calculations for InAs and find that some defect levels for InAs dislocations lie outside of the band gap where they cannot act as recombination centers. To provide some insight into the electronic structure of dislocations in ternary alloys, some examples relevant to InGaAs and GaAsP are included.
Microwave measurements of the tropolone–formic acid doubly hydrogen bonded dimer
Authors: Pejlovas Aaron M. , Serrato Agapito , Lin Wei , Kukolich Stephen G.
Published: January 2016

The microwave spectrum was measured for the doubly hydrogen bonded dimer formed between tropolone and formic acid. The predicted symmetry of this dimer was C2v(M), and it was expected that the concerted proton tunneling motion would be observed. After measuring 25 a- and b-type rotational transitions, no splittings which could be associated with a concerted double proton tunneling motion were observed. The calculated barrier to the proton tunneling motion is near 15 000 cm−1, which would likely make the tunneling frequencies too small to observe in the microwave spectra. The rotational and centrifugal distortion constants determined from the measured transitions were A = 2180.7186(98) MHz, B = 470.873 90(25) MHz, C = 387.689 84(22) MHz, DJ = 0.0100(14) kHz, DJK = 0.102(28) kHz, and DK = 13.2(81) kHz. The B3LYP/aug-cc-pVTZ calculated rotational constants were within 1% of the experimentally determined values.
Near-zero temperature coefficient of resistivity associated with magnetic ordering in antiperovskite Mn3+xNi1−xN
Authors: Deng Sihao , Sun Ying , Wang Lei , Wu Hui , Shi Kewen , Hu Pengwei , Huang Qingzhen , Wang Cong
Published: January 2016

The near-zero temperature coefficient of resistivity (NZ-TCR) behavior is reported in the antiperovskite compounds Mn3+xNi1−xN (0 ≤ x ≤ 0.333). Our results indicate that the broad temperature range (above 275 K extending to above 220 K) of NZ-TCR is obtained by Mn doping at the Ni site. The short-range magnetic ordering is revealed by both neutron powder diffraction and inverse magnetic susceptibility. Further, we find a strong correlation between the anomalous resistivity change of Mn3+xNi1−xN from the metal-like to the NZ-TCR behavior and the lack of the long-range magnetic ordering. The possible mechanism of NZ-TCR behavior is discussed using the spin-disorder scattering model.
Giant semiclassical magnetoresistance in high mobility TaAs2 semimetal
Authors: Wu Desheng , Liao Jian , Yi Wei , Wang Xia , Li Peigang , Weng Hongming , Shi Youguo , Li Yongqing , Luo Jianlin , Dai Xi , Fang Zhong
Published: January 2016

We report the observation of colossal positive magnetoresistance (MR) in single crystalline, high mobility TaAs2 semimetal. The excellent fit of MR by a single quadratic function of the magnetic field B over a wide temperature range (T = 2–300 K) suggests the semiclassical nature of the MR. The measurements of Hall effect and Shubnikov-de Haas oscillations, as well as band structure calculations, suggest that the giant MR originates from the nearly perfectly compensated electrons and holes in TaAs2. The quadratic MR can even exceed 1 200 000% at B = 9 T and T = 2 K, which is one of the largest values among those of all known semi-metallic compounds, including the very recently discovered WTe2 and NbSb2. The giant positive magnetoresistance in TaAs2 not only has a fundamentally different origin from the negative colossal MR observed in magnetic systems but also provides a nice complemental system that will be beneficial for applications in magnetoelectronic devices.
Polar-direct-drive experiments with contoured-shell targets on OMEGA
Authors: Marshall F. J. , Radha P. B. , Bonino M. J. , Delettrez J. A. , Epstein R. , Glebov V. Yu. , Harding D. R. , Stoeckl C. , Frenje J. A. , Gatu Johnson M. , Séguin F. H. , Sio H. , Zylstra A. , Giraldez E.
Published: January 2016

Polar-driven direct-drive experiments recently performed on the OMEGA Laser System have demonstrated the efficacy of using a target with a contoured shell with varying thickness to improve the symmetry and fusion performance of the implosion. The polar-driven contoured-shell implosions have substantially reduced low mode perturbations compared to polar-driven spherical-shell implosions as diagnosed by x-ray radiographs up to shell stagnation. Fusion yields were increased by more than a factor of ∼2 without increasing the energy of the laser by the use of contoured shells.
Identifying and discriminating phase transitions along decaying shocks with line imaging Doppler interferometric velocimetry and streaked optical pyrometry
Authors: Millot Marius
Published: January 2016

Ultrafast line-imaging velocity interferometer system for any reflector and streaked optical pyrometry are now commonly used to obtain high precision equation of state and electronic transport data under dynamic compression at major high energy density science facilities. We describe a simple way to improve distinguishing phase transformation signatures from other signals when monitoring decaying shock waves. The line-imaging capability of these optical diagnostics offers additional supporting evidence to the assignment of particular anomalies—such as plateaus or reversals—to the occurrence of a phase transition along the Hugoniot. We illustrate the discussion with two example datasets collected during laser driven shock compression of quartz and stishovite.
The role of asymmetrical and repulsive coupling in the dynamics of two coupled van der Pol oscillators
Authors: Astakhov Sergey , Gulai Artem , Fujiwara Naoya , Kurths Jürgen
Published: January 2016

A system of two asymmetrically coupled van der Pol oscillators has been studied. We show that the introduction of a small asymmetry in coupling leads to the appearance of a “wideband synchronization channel” in the bifurcational structure of the parameter space. An increase of asymmetry and transition to repulsive interaction leads to the formation of multistability. As the result, the tip of the Arnold's tongue widens due to the formation of folds defined by saddle-node bifurcation curves for the limit cycles on the torus.
Two-dimensional percolation threshold in confined Si nanoparticle networks
Authors: Laube J. , Gutsch S. , Wang D. , Kübel C. , Zacharias M. , Hiller D.
Published: January 2016

Non-percolating and percolating silicon quantum dot (QD) networks were investigated by plane-view energy filtered transmission electron microscopy (EF-TEM). The Si QD networks were prepared by plasma enhanced chemical vapor deposition on free standing 5 nm Si3N4 membranes, followed by high temperature annealing. The percolation threshold from non-percolating to percolating networks is found to be in between a SiOx stoichiometry of SiO0.5 up to SiO0.7. Using the EF-TEM images, key structural parameters of the Si QD ensemble were extracted and compared, i.e., their size distribution, nearest neighbor distance, and circularity. Increasing the silicon excess within the SiOx layer results in an ensemble of closer spaced, less size-controlled, and less circular Si QDs that give rise to coupling effects. Furthermore, the influence of the structural parameters on the optical and electrical Si QD ensemble properties is discussed.
Energy bandgap variation in oblique angle-deposited indium tin oxide
Authors: Kim Kyurin , Park Jun Hyuk , Kim Hyunsoo , Kim Jong Kyu , Fred Schubert E. , Cho Jaehee
Published: January 2016

Indium tin oxide (ITO) thin films deposited using the oblique angle deposition (OAD) technique exhibit a strong correlation between structural and optical properties, especially the optical bandgap energy. The microstructural properties of ITO thin films are strongly influenced by the tilt angle used during the OAD process. When changing the tilt angle, the refractive index, porosity, and optical bandgap energy of ITO films also change due to the existence of a preferential growth direction at the interface between ITO and the substrate. Experiments reveal that the ITO film's optical bandgap varies from 3.98 eV (at normal incident deposition) to 3.87 eV (at a 60° tilt angle).
Magnetic nanoparticle composed nanowires fabricated by ultrashort laser ablation in air
Authors: Nedyalkov N. , Nakajima Y. , Terakawa M.
Published: January 2016

In this paper, a method for formation of nanoparticle composed wires of magnetic materials is presented. The method is based on ultrashort laser ablation in air at atmospheric pressure in the presence of external magnetic field. The material ablated at these conditions is composed of nanosized spherical particles that form chains with length of a few tens of microns. These structures are deposited on the substrate's surface as they are arranged parallel to the applied magnetic field. The obtained results can be used for designing a technology for magnetic materials assembly at open environment conditions.
Pool boiling enhancement through bubble induced convective liquid flow in feeder microchannels
Authors: Jaikumar A. , Kandlikar S. G.
Published: January 2016

Bubbles departing from the nucleation sites induce a liquid flow from the bulk to the heated surface during pool boiling. Alternating the nucleating regions with non-nucleating regions facilitates separate liquid-vapor pathways for departing vapor bubbles and returning liquid. We explored an additional enhancement through liquid feeder channels on the heater surface directing the returning liquid towards the nucleating region. The nucleating bubbles were confined to the nucleating region as the returning liquid flow induced strong convective currents over the non-nucleating regions. In the best performing configuration, the nucleating regions were 0.5 mm wide, separated by non-nucleating regions of width 2.125 mm, which corresponded to the bubble departure diameter. The non-nucleating regions contained 0.5 mm wide feeder channels directing liquid towards the nucleating region. High speed images indicated distinct vapor columns over the nucleating regions with liquid channeled through the feeder channels. At higher heat fluxes, the strong liquid currents established over the feeder channels suppressed any undesirable nucleation in them keeping the separated vapor-liquid pathways functional. This enhancement technique resulted in a critical heat flux of 394 W/cm2 at a wall superheat of 5.5 °C which translated to a heat transfer coefficient of 713 kW/m2 °C. The additional surface area and high heat transfer coefficient due to microchannel flow in feeder channels, and the unobstructed surface available for the bubbles to expand over the prime heat transfer surface area before departing were seen to be responsible for their superior performance.
Communication: Temperature derivative of the dielectric constant gives access to multipoint correlations in polar liquids
Authors: Matyushov Dmitry V. , Richert Ranko
Published: January 2016

Fluctuations of the dipole moment of a macroscopic dielectric sample are induced by thermal motions. The variance of the sample dipole moment, characterizing the extent of thermal fluctuations, is a decaying function of temperature for many polar liquids. This result is inconsistent with the Nyquist (fluctuation-dissipation) theorem predicting the variance of a macroscopic property to grow linearly with temperature. The reason for a qualitatively different behavior is in strong multi-particle correlations of dipolar orientations. An equation connecting the temperature slope of the dielectric constant to a static three-point correlation function is derived. When applied to experimental data for polar and hydrogen-bonding liquids at normal conditions, the three-point correlations of different liquids fall on a single master curve as a function of the dielectric constant. Static three-point correlation functions can potentially reflect the growing spatial correlation length on approach to the glass transition. However, the measured temperature slope of the dielectric constant of glycerol does not indicate a change in such a lengthscale.
Force-dependent switch in protein unfolding pathways and transition-state movements
Authors: Zhuravlev Pavel I. , Hinczewski Michael , Chakrabarti Shaon , Marqusee Susan , Thirumalai D.
Published: January 2016

Significance

Single-domain proteins with symmetrical arrangement of secondary structural elements in the native state are expected to fold by diverse pathways. However, understanding the origins of pathway diversity, and the experimental signatures for identifying it, are major challenges, especially for small proteins with no obvious symmetry in the folded states. We show rigorously that upward curvature in the logarithm of unfolding rates as a function of force (or denaturants) implies that the folding occurs by diverse pathways. The theoretical concepts are illustrated using simulations of src SH3 domain, which explain the emergence of parallel pathways in single-molecule pulling experiments and provide structural description of the routes to the unfolded state. We make testable predictions illustrating the generality of the theory.
Properties assessment of the first industrial coils of low-density duplex δ-TRIP steel
Authors: Xiong X. C. , Sun L. , Wang J. F. , Jin X. Y. , Wang L. , Xu B. Y. , Chen P. , Wang G. D. , Yi H. L.
Published: January 2016

A novel low-density steel with high aluminium content was, for the first time, manufactured as coils by the conventional industry process consisting of continuous casting followed by hot-rolling and cold-rolling. The duplex δ-TRIP microstructure, comprising a mixture of blocky retained austenite and both δ- and α-ferrite, was then produced by laboratory-scale heat treatments. The microstructure generation was achieved by an intercritical annealing followed by direct quenching, which was the same process as that for producing conventional dual-phase steels. The alloy exhibits quite interesting mechanical properties with a combination of 930 MPa tensile strength and of 21% total elongation, both in rolling and transverse directions. The formability of this novel alloy was assessed and discussed.
Quantifying the metallurgical response of a nuclear steel to welding thermal cycles
Authors: O'Meara N. , Abdolvand H. , Francis J. A. , Smith S. D. , Withers P. J.
Published: January 2016

Solid-state phase transformations can drastically influence the evolution of stress in welds due to the strains associated with the transformations and related changes in mechanical properties. As such, finite-element predictions of welding residual stresses need reliable materials data including, where applicable, information on phase transformation kinetics and phase- and temperature-dependent material properties. Owing to a scarcity of such data, many authors have used uncalibrated empirical modelling approaches for the prediction of welding residual stresses. This paper addresses this critical shortage for an important nuclear pressure vessel (SA508) steel. Austenite formation, grain growth and decomposition data are presented and subsequently used to calibrate transformation models. These models are shown to accurately predict microstructure and residual stresses for experimental test cases.

This paper is part of a Themed Issue on Measurement, modelling and mitigation of residual stress.
Quenching and partitioning steel produced through hot rolling, direct quenching and annealing
Authors: Guo H. , Zhao A. , Ding R. , Zhi C. , He J.
Published: January 2016

A novel type of quenching and partitioning steel was developed using direct quenching after hot finishing rolling, followed by intercritical annealing, quenching and partitioning (DQ–Q&P) process. The desirable combination of strength and ductility was obtained. The effect of various intercritical annealing temperatures on the microstructures and mechanical proprieties was studied. With the decreasing intercritical annealing temperature, the amount of acicular retained austenite increased, which exhibited a good work-hardening behaviour resulting in enhanced tensile strength and total elongation. After annealing at 740°C, superior mechanical properties, which were the ultimate tensile strength of 1015 MPa and total elongation of 32.22%, were achieved.
Evolution of the microstructure and properties of laser-clad FeCrNiCoBx high-entropy alloy coatings
Authors: Zhang C. , Chen G. J. , Dai P. Q.
Published: January 2016

FeCrNiCoB x high-entropy alloy coatings were prepared by laser cladding, and the effects of boron addition on the microstructure, hardness and corrosion resistance of the coatings were studied. Results showed that the coatings comprised a simple FCC solid solution with boride precipitation. When 0.5 ≤  x ≤ 1.0, (Cr, Fe)2B with an orthorhombic structure was found in the coatings, and the hardness and corrosion resistance of the coatings were enhanced by increasing boron content. As x approached 1.25, the borides changed from orthorhombic (Cr, Fe)2B to tetragonal (Fe, Cr)2B, which deteriorated the corrosion resistance of the coatings. Stacking faults found in (Cr, Fe)2B may be caused by the phase transformation of borides.
Age and Growth of Atlantic Sturgeon in the New York Bight
Authors: Dunton Keith J. , Jordaan Adrian , Secor David H. , Martinez Christopher M. , Kehler Thomas , Hattala Kathy A. , Van Eenennaam Joel P. , T. Fisher Matthew , McKown Kim A. , Conover David O. , Frisk Michael G.
Published: January 2016

Accurate estimates of age and growth of fishes are important in the management and conservation of species and for the development of modeling approaches. Assessments of endangered or rare species typically are limited by poor or inadequate data owing to low abundance, unrepresentative sampling, and/or restrictions on sampling. Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus, which occurs along the east coast of North America, has five distinct population segments (DPSs) listed under the U.S. Endangered Species Act. The New York Bight (NYB) DPS is listed as endangered and represents the largest DPS in the United States. Coastal trawl surveys from 2005 to 2012 were used to evaluate the current age structure of the NYB DPS. A total of 21 year-classes (mean age = 8.89 years, n = 742 fish) were observed. Age data for the NYB DPS were combined with other available age estimates from multiple research laboratories and sources (n = 2,774) in the Hudson River and Delaware River as well from the coastal regions of New York, New Jersey, and Delaware from 1975 to 2012. Collectively, the combined data set captured much of the age range of the species, minimizing age biases and resulting in improved von Bertalanffy parameter estimates (L∞ = 278.87, K = 0.057, t0 = −1.27) with high overall model fit (r2 = 0.87). We assessed the effects of individual data sets through a series of leave-one-out bootstrap routines that evaluated the influence of each data set on growth parameter estimates. The parameter estimates of the von Bertalanffy growth function were influenced by sampling location and/or researcher effects. Despite these differences, the combined data set approach used here represents the most comprehensive study on the age-and-growth relationship of Atlantic Sturgeon and provides parameter estimates for the development of population dynamics models and valuable information for future management.

Received February 23, 2015; accepted September 24, 2015
Predation on Chinook Salmon Parr by Hatchery Salmonids and Fallfish in the Salmon River, New York
Authors: Johnson James H. , Nack Christopher C. , Chalupnicki Marc A. , Abbett Ross , McKenna J. E.
Published: January 2016

Naturally reproduced Chinook Salmon Oncorhynchus tshawytscha contribute substantially to the fishery in Lake Ontario. The Salmon River, a Lake Ontario tributary in New York, produces the largest numbers of naturally spawned Chinook Salmon, with parr abundance in the river often exceeding 10 million. In the spring of each year, large numbers of hatchery salmonid yearlings—potential predators of Chinook Salmon parr—are released into the Salmon River by the New York State Department of Environmental Conservation. We sought to examine predation on Chinook Salmon parr in the Salmon River during May and June prior to out-migration. Over the 4 years examined (2009–2012), annual consumption of Chinook Salmon parr by hatchery-released yearling steelhead O. mykiss and Coho Salmon O. kisutch ranged from 1.5 to 3.3 million and from 0.4 to 2.1 million, respectively. In 2009, Fallfish Semotilus corporalis were estimated to consume 2.9 million Chinook Salmon parr. Predation was higher in May, when the average TL of Chinook Salmon parr was 44.5 mm, than in June. Fallfish were also important predators of naturally reproduced steelhead subyearlings, consuming an estimated 800,000 steelhead in 2009. Hatchery-released yearling salmonids consumed 13.8–15.3% of the Chinook Salmon parr that were estimated to be present in the Salmon River during 2010–2012. Earlier releases of hatchery salmonid yearlings could reduce the riverine consumption of Chinook Salmon parr by facilitating the out-migration of yearlings prior to Chinook Salmon emergence.

Received February 23, 2015; September 29, 2015
Comparison of Electrofishing Techniques and Effort Allocation across Diel Time Periods, Seasons, Sites, and Habitat in the Ohio Coastal Waters of Western Lake Erie
Authors: Ross J. E. , Mayer C. M. , Tyson J. T. , Weimer E. J.
Published: January 2016

Coastal (<3-m depth) and nearshore (3–15-m depth) zones of large freshwater lakes are generally rich in complex habitats that are important for fisheries, but they are often highly degraded and understudied. We identified spatial and temporal sampling efficiencies for monitoring coastal fish communities in a large freshwater lake by use of electrofishing. During 2011 and 2012, we sampled 21 coastal sites in Lake Erie's western basin via daytime and nighttime electrofishing with multiple replicates throughout the summer sampling season. Nighttime electrofishing captured more species and more individuals with less effort than daytime electrofishing; nighttime electrofishing conducted early in the season (i.e., late spring and early summer) was more efficient than that conducted late in the season (i.e., late summer and early fall). A sampling design based on 500 m of shoreline per site required fewer sites and person-hours to attain 65% and 75% of total species richness (6 and 11 sites, respectively) than a design that used 100 m/site. A 300-m/site design was more efficient at targeting 90% of total species richness. Targeting of wetland habitat increased the number of species captured but missed species that were only found at other habitat types. A sampling design that targeted 11 sites (75% of species richness) sufficiently described fish community metrics (e.g., number of tolerant species) since the design captured nearly all fish species that were relevant to each metric. This study provides the foundation for a coastal monitoring program in western Lake Erie and serves as a starting point for program development in other large freshwater lakes.

Received January 16, 2015; accepted October 8, 2015
Introduced Flathead Catfish Consumptive Demand on Native Fishes of the Upper Gila River, New Mexico
Authors: Hedden Skyler C. , Gido Keith B. , Whitney James E.
Published: January 2016

Predation by nonnative fish is often cited as a leading cause of declining native fish populations, but quantifying these negative interactions is difficult. Bioenergetics modeling provides a tool to estimate consumptive demand of nonnative species and to identify those that pose the greatest threats to native biota. We used bioenergetics modeling to estimate the consumptive demand of Flathead Catfish Pylodictis olivaris on native fishes in the upper Gila River, New Mexico, across an elevational gradient. Model results were coupled with measured densities and size structure of Flathead Catfish populations, as well as water temperatures, to predict its predatory threat. Potential consumption was highest at lower elevation sites because of higher water temperatures, but actual consumption was highest at mid-elevation sites because of the prevalence of larger individuals there. Potential annual consumptive demand of Flathead Catfish on native fish across our nine sampling sites ranged from 0.0 to 3.1 g/m2, which exceeded native fish productivity at one site. Our results identify areas within the upper Gila River where introduced Flathead Catfish consumption is likely to negatively impact native fish populations.
Molly users versus Nonusers in a Sample of College Alcohol Drinkers: Differences in Substance-Related Harms and Sensation Seeking
Authors: Linden-Carmichael Ashley N. , Stamates Amy L. , Sheehan Brynn E. , Lau-Barraco Cathy
Published: January 2016

Background: Molly is one form of MDMA (3,4-methylenedioxymethamphetamine) that is touted to be more “pure” and potentially less harmful than other forms, such as ecstasy. Media reports and case studies suggest that this drug is popular among college students and is related to adverse health problems. The current study sought to address the knowledge gaps about Molly by examining whether users differ in substance use outcomes and sensation seeking than nonusers. Specifically, this study tested whether Molly users engaged in heavier use of other substances and experienced more substance-related harms in general than nonusers. Further, the current study investigated whether Molly users exhibited higher levels of sensation seeking than nonusers. Lastly, this study examined whether Molly user status would be associated with substance-related harms beyond the confounding influence of other substance use and trait sensation seeking. Methods: Participants were 710 (71.9% female) college alcohol drinkers who completed self-report surveys about substance use (i.e., Molly, alcohol, and other drug use), substance-related problems, and sensation seeking. Results: Results revealed that approximately 12% of the sample reported lifetime Molly use. Molly users compared with nonusers reported higher levels of other drug use, alcohol use, substance-related problems, and sensation seeking. Further, Molly users reported experiencing poorer substance use outcomes (e.g., blacking out, academic/occupational problems, and withdrawal symptoms) after accounting for sensation seeking and other substance use. Conclusions: These findings indicate that Molly users are higher in sensation seeking and that use is uniquely related to greater risk for substance-related harms. These preliminary findings demonstrate a need for correcting possible misperceptions regarding the purity of Molly and educating users on the potential for experiencing associated harms. Such information could be used to develop efficacious prevention programming for college students.
A Delayed Injection-Site Reaction in a Patient Receiving Extended-Release Naltrexone
Authors: Ahamad Keith , Korthuis P. Todd , Lum Paula J. , Johnson Cheyenne , Wood Evan
Published: January 2016

Background

Pharmacotherapy, such as oral naltrexone, has proven effective in treating alcohol use disorder, although medication adherence has presented challenges. Although a formulation of extended-release naltrexone for intramuscular injection has been developed to counter daily adherence issues, injection-site reactions can occur within days of depot injection. Case: The authors report a case of an individual with alcohol use disorder who had a previously undescribed delayed injection-site reaction that occurred 11 days after injection. Subsequent challenge with the medication resulted in recurrence of the reaction. Discussion: Although extended-release naltrexone is generally well tolerated, injection-site reactions can complicate treatment and can appear more than 10 days after medication administration.
A Tiered Model of Substance use Severity and Life Complexity: Potential for Application to Needs-Based Planning
Authors: Barker S. Fiona , Best David , Manning Victoria , Savic Michael , Lubman Dan I. , Rush Brian
Published: January 2016

Background: In order to improve long-term outcomes for individuals with substance use problems, one approach is to adopt a system planning model that considers both addiction severity and life complexities. The tiered approach has been developed and tested to describe systems-level need based on levels of risk and problem severity. Methods: An existing tiered model was modified to accommodate Australian data, incorporating substance use severity and life complexity. The hypothesis was that tiers would reflect differences in well-being amongst help seekers such that an increase in tier would be associated with a reduction in well-being, suggesting the need for more intensive (and integrated) interventions. The model was tested using 2 data sets of screening data, collected from face-to-face alcohol and other drug (AOD) service ( n = 430) and online help ( n = 309) seekers, drawn from a larger sample of 2,766 screens. The screen included demographic information and substance use, mental health, and quality of life measures. Results: There was a significant relationship between well-being and tier ranking, suggesting that the model adequately captured elements of severity and complexity that impact on well-being. There were notable differences between the help-seeking populations with a higher proportion of online respondents allocated to lower tiers and more face-to-face respondents allocated to higher tiers. However, there was an overlap in these populations, with more than half of online respondents classified as higher tiers and one fifth of face-to-face respondents classified as lower tiers. This suggests that the model can be used both to assess unmet need in out-of-treatment groups and demand in the absence of dependence in a subpopulation of the face-to-face treatment population. C onclusions: The tiered model provides a method to understand levels of AOD treatment need and, as part of needs-based planning, may be used to optimize treatment responses and resourcing.
Contribution of Elevated Intracellular Calcium to Pulmonary Arterial Myocyte Alkalinization during Chronic Hypoxia
Authors: Undem Clark , Luke Trevor , Shimoda Larissa A.
Published: January 2016

In the lung, exposure to chronic hypoxia (CH) causes pulmonary hypertension, a debilitating disease. Development of this condition arises from increased muscularity and contraction of pulmonary vessels, associated with increases in pulmonary arterial smooth muscle cell (PASMC) intracellular pH (pHi) and Ca2+ concentration ([Ca2+]i). In this study, we explored the interaction between pHi and [Ca2+]i in PASMCs from rats exposed to normoxia or CH (3 weeks, 10% O2). PASMC pHi and [Ca2+]i were measured with fluorescent microscopy and the dyes BCECF and Fura‐2. Both pHi and [Ca2+]i levels were elevated in PASMCs from hypoxic rats. Exposure to KCl increased [Ca2+]i and pHi to a similar extent in normoxic and hypoxic PASMCs. Conversely, removal of extracellular Ca2+ or blockade of Ca2+ entry with NiCl2 or SKF 96365 decreased [Ca2+]i and pHi only in hypoxic cells. Neither increasing pHi with NH4Cl nor decreasing pHi by removal of bicarbonate impacted PASMC [Ca2+]i. We also examined the roles of Na+/Ca2+ exchange (NCX) and Na+/H+ exchange (NHE) in mediating the elevated basal [Ca2+]i and Ca2+‐dependent changes in PASMC pHi. Bepridil, dichlorobenzamil, and KB‐R7943, which are NCX inhibitors, decreased resting [Ca2+]i and pHi only in hypoxic PASMCs and blocked the changes in pHi induced by altering [Ca2+]i. Exposure to ethyl isopropyl amiloride, an NHE inhibitor, decreased resting pHi and prevented changes in pHi due to changing [Ca2+]i. Our findings indicate that, during CH, the elevation in basal [Ca2+]i may contribute to the alkaline shift in pHi in PASMCs, likely via mechanisms involving reverse‐mode NCX and NHE.