bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the brown rice diet on visceral obesity and endothelial function: the BRAVO study
Authors: Shimabukuro Michio , Higa Moritake , Kinjo Rie , Yamakawa Ken , Tanaka Hideaki , Kozuka Chisayo , Yabiku Kouichi , Taira Shin-Ichiro , Sata Masataka , Masuzaki Hiroaki
Published: August 2013

Brown rice (BR) and white rice (WR) produce different glycaemic responses and their consumption may affect the dietary management of obesity. In the present study, the effects of BR and WR on abdominal fat distribution, metabolic parameters and endothelial function were evaluated in subjects with the metabolic syndrome in a randomised cross-over fashion. In study 1, acute postprandial metabolic parameters and flow- and nitroglycerine-mediated dilation (FMD and NMD) of the brachial artery were determined in male volunteers with or without the metabolic syndrome after ingestion of either BR or WR. The increases in glucose and insulin AUC were lower after ingestion of BR than after ingestion of WR (P= 0·041 andP= 0·045, respectively). FMD values were decreased 60 min after ingestion of WR (P= 0·037v. baseline), but the decrease was protected after ingestion of BR. In study 2, a separate cohort of male volunteers (n27) with the metabolic syndrome was randomised into two groups with different BR and WR consumption patterns. The values of weight-based parameters were decreased after consumption of BR for 8 weeks, but returned to baseline values after a WR consumption period. Insulin resistance and total cholesterol and LDL-cholesterol levels were reduced after consumption of BR. In conclusion, consumption of BR may be beneficial, partly owing to the lowering of glycaemic response, and may protect postprandial endothelial function in subjects with the metabolic syndrome. Long-term beneficial effects of BR on metabolic parameters and endothelial function were also observed.
A meta-analysis study of gene expression datasets in mouse liver under PPARα knockout
Authors: HE KAN , WANG ZHEN , WANG QISHAN , PAN YUCHUN
Published: August 2013

Gene expression profiling of peroxisome-proliferator-activated receptor α (PPARα) has been used in several studies, but there were no consistent results on gene expression patterns involved in PPARα activation in genome-wide due to different sample sizes or platforms. Here, we employed two published microarray datasets both PPARα dependent in mouse liver and applied meta-analysis on them to increase the power of the identification of differentially expressed genes and significantly enriched pathways. As a result, we have improved the concordance in identifying many biological mechanisms involved in PPARα activation. We suggest that our analysis not only leads to more identified genes by combining datasets from different resources together, but also provides some novel hepatic tissue-specific marker genes related to PPARα according to our re-analysis.
Meeting summary: ethical aspects of whole exome and whole genome sequencing studies (WES/WGS) in rare diseases, Tel Aviv, Israel, January 2013
Authors: FARBEROV LUBA , GILAM AVITAL , ISAKOV OFER , SHOMRON NOAM
Published: August 2013

A recent E-Rare workshop reviewed the ethical aspects of whole exome and whole genome-sequencing studies (WES and WGS, respectively) in rare diseases. Leveraging new genomic technologies, which output vast amounts of known and novel genetic variants, researchers are learning more about the genetic basis and mechanisms involved in rare diseases. In some cases, these findings are translated into diagnostic tools for the benefit of rare disease patients. Among the disclosed data, which can assist in treatment management, incidental findings await, bringing with them ethical concerns for the clinicians, researchers and patients.
“Roving Executioners”? The Use of Lethal Force in Malawi and Warnings from R v Cheuka
Authors: Gumboh Esther
Published: August 2013

Between 2009 and 2011, Malawi witnessed an increase in the use of lethal force by the police. The president urged the police to implement a “shoot to kill” policy, a move which received wide acceptance in the country but also raised concerns from human rights activists. In 2009, the Malawi High Court in R v Cheuka considered the scope of section 44 of the Police Act which governs the use of firearms by the police. Clouded by the human rights implications of the shooting which led to the case, the court misinterpreted the law by introducing principles of international law that were not expressly provided for. The court also failed to expound a comprehensive test to determine the shooter's intentions. Nevertheless, the decision sheds some light on the efficacy of the law on the use of lethal force in Malawi and the question of whether a shoot to kill policy can be reconciled with the law.
DO SELF-REPORTED HEALTH INDICATORS PREDICT MORTALITY? EVIDENCE FROM MATLAB, BANGLADESH
Authors: RAZZAQUE ABDUR , MUSTAFA A. H. M. G. , STREATFIELD PETER KIM
Published: August 2013

In order to understand current and changing patterns of population health, there is a clear need for high-quality health indicators. The World Health Organization Study on Global AGEing and Adult Health (SAGE) survey platform and the International Network for the Demographic Evaluation of Populations and Their Health in developing countries (INDEPTH) generated data for this study. A total of 4300 people aged 50 years or older were selected randomly from the Matlab Health and Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research, Bangladesh. The health indicators derived from these survey data are self-rated general health, overall health state, quality of life and disability levels. The outcome of the study is mortality over a 2-year follow-up since the survey. Among the four health indicators, only self-rated health was significantly associated with subsequent mortality irrespective of sex: those who reported bad health had higher mortality than those who reported good health, even after controlling for socio-demographic factors. For all other three health indicators, such associations exist but are significant only for males, while for females it is significant only for ‘quality of life’.
DETERMINANTS OF UNPROTECTED CASUAL HETEROSEXUAL SEX IN GHANA
Authors: KUMI-KYEREME AKWASI , TUOYIRE DEREK A. , DARTEH EUGENE K. M.
Published: August 2013

Casual heterosexual sex remains a significant contributor to HIV transmissions in Ghana. The study used data from the 2008 Ghana Demographic and Health Survey (GDHS) to assess the socio-demographic, economic and spatial factors influencing unprotected casual heterosexual sex among men and women. The results of the binary logistic regression models revealed that women aged 35–44 had significantly higher odds of engaging in unprotected casual heterosexual sex than those aged 15–24, unlike the men. There were significantly lower odds of unprotected casual heterosexual sex for women and men with exposure to print media compared with those without exposure. Compared with men residing in the Western Region, unprotected casual heterosexual sex was significantly less likely among those in the Upper East Region. There is the need for behavioural change campaigns in Ghana that take into consideration the multiplicity of factors that determine unprotected casual heterosexual sex.
Mechanisms of change underlying the efficacy of cognitive behaviour therapy for chronic fatigue syndrome in a specialist clinic: a mediation analysis
Authors: Stahl D. , Rimes K. A. , Chalder T.
Published: August 2013

Background

Several randomized controlled trials (RCTs) have shown that cognitive behavioural psychotherapy (CBT) is an efficacious treatment for chronic fatigue syndrome (CFS). However, little is known about the mechanisms by which the treatment has its effect. The aim of this study was to investigate potential mechanisms of change underlying the efficacy of CBT for CFS. We applied path analysis and introduce novel model comparison approaches to assess a theoretical CBT model that suggests that fearful cognitions will mediate the relationship between avoidance behaviour and illness outcomes (fatigue and social adjustment).

Method

Data from 389 patients with CFS who received CBT in a specialist service in the UK were collected at baseline, at discharge from treatment, and at 3-, 6- and 12-month follow-ups. Path analyses were used to assess possible mediating effects. Model selection using information criteria was used to compare support for competing mediational models.

Results

Path analyses were consistent with the hypothesized model in which fear avoidance beliefs at the 3-month follow-up partially mediate the relationship between avoidance behaviour at discharge and fatigue and social adjustment respectively at 6 months.

Conclusions

The results strengthen the validity of a theoretical model of CBT by confirming the role of cognitive and behavioural factors in CFS.
Comparison of organic and conventional managements on yields, nutrients and weeds in a corn–cabbage rotation
Authors: Bajgai Yadunath , Kristiansen Paul , Hulugalle Nilantha , McHenry Melinda
Published: August 2013

Conventional soil management systems (SMS) use synthetic inputs to maximize crop productivity, which leads to environmental degradation. Organic SMS is an alternative that is claimed to prevent or mitigate such negative environmental impacts. Vegetable production systems rely on frequent tillage to prepare beds and manage weeds, and are also characterized by little crop residue input. The use of crop residues and organic fertilizers may counteract the negative impacts of intensive vegetable production. To test this hypothesis, we evaluated the effect of sweet corn (Zea maysL. var.rugosa) residue incorporation in a corn–cabbage (Brassica oleraceaL.) rotation on crop yields, nutrient uptake, weed biomass and soil nutrients for organic and conventional SMS in two contrasting soil types (a Chromosol and a Vertosol). Yields of corn and cabbage under the organic SMS were not lower than the conventional SMS, possibly due to the equivalent N, P and K nutrients applied. Macro-nutrient uptake between the organic and conventional SMS did not differ for cabbage heads. Corn residue incorporation reduced the average in-crop weed biomass in cabbage crops by 22% in 2010 and by 47% in 2011. Corn residue-induced inhibitions on weed biomass may be exploited as a supplementary tool to mechanical weed control for the organic SMS, potentially reducing the negative impacts of cultivation on soil organic carbon. Residue incorporation and the organic SMS increased the average total soil N by 7 and 4% compared with the treatments without residue and the conventional SMS, respectively, indicating the longer-term fertility gains of these treatments. Exchangeable K, but not Colwell P, in the soil was significantly increased by residue incorporation. The clayey Vertosol conserved higher levels of nutrients than the sandy Chromosol. Yields under organic SMS can match that of conventional SMS. Residue incorporation in soil improved soil nutrients and reduced weed biomass.
Negative Modeling Results: A Dime a Dozen or a Stepping Stone to Scientific Discovery?
Authors: Hendriks B
Published: August 2013

CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e48; doi:10.1038/psp.2013.28; advance online publication 12 June 2013
Transient kinetic analyses of the ribonuclease H cleavage activity of HIV-1 reverse transcriptase in complex with efavirenz and/or a β-thujaplicinol analogue
Authors: Herman Brian D. , Sluis-Cremer Nicolas
Published: August 2013

EFV (efavirenz) and β-thujaplicinol [2,7-dihydroxy-4-1(methylethyl)-2,4,6-cycloheptatrien-1-one] have contrasting effects on the RNase H activity of HIV-1 RT (reverse transcriptase). EFV binds in the non-nucleoside inhibitor-binding pocket and accelerates this activity, whereas β-thujaplicinol binds in the RNase H active site and inhibits it. We have used pre-steady-state kinetic analyses to gain an insight into the mechanism by which EFV and a β-thujaplicinol analogue [19616 (2,7-dihydroxy-2,4,6-cyclo-heptatrien-1-one)] modulate RT RNase H activity. Our data show that EFV and 19616 have no effect on polymerase-dependent RNase H cleavages. However, both compounds significantly affected the rates of polymerase-independent RNase H cleavages. In regard to the latter, we found no evidence that the bound RNA/DNA template/primer substrate restricted 19616 from interacting with RT. In light of these data, we propose a model in which 19616 binds to the RNase H active site of RT after the primary polymerase-dependent RNase H cleavage has occurred and stabilizes the 3′-end of the DNA primer in the polymerase active site thus blocking the enzyme's ability to carry out the polymerase-independent cleavages. By contrast, EFV destabilizes the 3′-end of the DNA primer in the DNA polymerase active site and promotes RT-mediated polymerase-independent cleavages. Consistent with this model, we show antagonism between EFV and 19616.
Robust fault‐tolerant control of uncertain fractional‐order systems against actuator faults
Authors: Shen Hao , Song Xiaona , Wang Zhen
Published: August 2013

This study investigates the problem of robust fault‐tolerant control for uncertain fractional‐order (FO) systems against actuator faults, whose commensurate order α is assumed to be 1 ≤ α  < 2. By using reciprocal projection lemma and some properties of Kronecker product, the authors present a sufficient condition for the existence of fault‐tolerant FO dynamic output feedback controllers for the FO systems with polytope‐type uncertainty. The controller designed here takes the possible actuator faults into consideration and ensures the resulting closed‐loop system is robustly stable. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed design method.
Fuzzy control synthesis for large‐scale systems with weighted interconnections
Authors: Chang Wei , Wang Wen‐June
Published: August 2013

This study examines the stabilisation problem associated with a particular type of large‐scale system. This type of large‐scale system consists of several non‐linear subsystems, which are connected to each other via interconnections of variable weighting. Interconnections of variable weighting between two subsystems denote that the interaction strength between the two subsystems is variable. Moreover, the weight may even be zero at some times or in some cases. In this study the authors suppose that the range of weight variation between any two subsystems is known, and that the stabilisation conditions for the large‐scale system are derived and that decentralised controllers which satisfy the conditions are synthesised. In the main result derivation, the Takagi–Sugeno (T –S) fuzzy model of a large‐scale system is used and a parallel distribution compensation (PDC) type fuzzy controller is synthesised based on the linear‐matrix‐inequality (LMI) method. Finally, a numerical example is given to demonstrate that the main theorem is applicable and the synthesised controller is effective.
Dissipative Hamiltonian realisation and decentralised saturated control of multi‐machine multi‐load power systems
Authors: Liu Yanhong , Li Jianyong , Ding Qingqing , Chu Bing
Published: August 2013

Using the energy‐based Hamiltonian function method, this study investigates the decentralised saturated excitation control of multi‐machine multi‐load power systems based on the structure preserving dynamic model. First, a constructive procedure is proposed for the dissipative Hamiltonian realisation of non‐linear differential algebraic systems and transform the power system to its equivalent dissipative Hamiltonian system. Constant feedforward control is proposed to adjust the system to the desired equilibrium point. Then, we put forward a decentralised saturated excitation controller using only the local information. Simulation results show that the proposed control scheme can effectively improve the transient stability of the power system.
Influence of the surface charge on the homogeneity of colloidal crystals
Authors: Zhou Hongwei , Xu Shenghua , Ouyang Wenze , Sun Zhiwei , Liu Lixia
Published: August 2013

Five groups of suspensions composed of polystyrene particles, having similar size but different effective surface charge, were adopted to investigate the effects of surface charge and volume fraction on the homogeneity of colloidal crystals through checking the difference between Dexp and Duni by reflection spectroscopy method (Dexp, Duni are the experimental and the expected value of the average nearest neighbor interparticle distance by assuming a uniform structure, respectively). We found volume fractions (ranging from 0.006 to 0.02) and structure types basically have no influence on the values of Dexp/Duni. Moreover, for crystals formed by lowly charged particles, Dexp/Duni is approximately equal to 1, implying the crystals are homogeneous. With the increase of effective surface charge, Dexp gradually deviates from Duni and the formed crystals become inhomogeneous. Our experimental observations are in accordance with the previous simulation results. Additionally, we also found Dexp/Duni initially drops quickly with increasing effective surface charge and then it tends to an asymptotic value (∼0.85), it is supposedly due to the saturation of effective charge. Our relevant computer simulations confirmed that the study scheme that using Dexp/Duni as an indicator to assess the homogeneity of crystal structure is tenable and the simulation results are consistent with experiments.
A gyro-gauge independent minimal guiding-center reduction by Lie-transforming the velocity vector field
Authors: de Guillebon L. , Vittot M.
Published: August 2013

We introduce a gyro-gauge independent formulation of a simplified guiding-center reduction, which removes the fast time-scale from particle dynamics by Lie-transforming the velocity vector field. This is close to Krylov-Bogoliubov method of averaging the equations of motion, although more geometric. At leading order, the Lie-transform consists in the generator of Larmor gyration, which can be explicitly inverted, while working with gauge-independent coordinates and operators, by using the physical gyro-angle as a (constrained) coordinate. This brings both the change of coordinates and the reduced dynamics of the minimal guiding-center reduction order by order in a Larmor radius expansion. The procedure is algorithmic and the reduction is systematically derived up to full second order, in a more straightforward way than when Lie-transforming the phase-space Lagrangian or averaging the equations of motion. The results write up some structures in the guiding-center expansion. Extensions and limitations of the method are considered.
Local order and dynamic properties of liquid and undercooled Cu55Hf45 and Cu62Hf38 alloys by ab initio molecular dynamics
Authors: Jakse N. , Nguyen T. L. T. , Pasturel A.
Published: August 2013

Atomic structures of liquid and undercooled Cu55Hf45 and Cu62Hf38 alloys have been studied using first-principles molecular dynamics simulations. It is found that both chemical short-range order and icosahedral short-range order are more pronounced at xCu = 0.55. We also evidence differences with the atomic structures of parent CuxZr1-x alloys. In examining the dynamic properties, we show that diffusivity and viscosity are closely related to the local structures of these two alloys. More particularly, we show that the icosahedral ordering is responsible for the more pronounced slowing down of the dynamics in the Cu55Hf45 alloy leading to a non-Arrhenius behavior in the undercooled region.
Formation of uni-directional ultrathin metallic YSi2 nanowires on Si(110)
Authors: Hus Saban M. , Weitering Hanno H.
Published: August 2013

Ultrathin YSi2 nanowires were grown epitaxially on the Si(110) surface. High-aspect-ratio nanowire growth is induced by the strongly anisotropic lattice-match between the silicide crystal lattice and the Si(110) surface, similar to the established formation of rare-earth silicide nanowires on Si(100). In contrast to the Si(100) case, however, YSi2 nanowires on Si(110) grow in a single orientation along the [11¯0] direction and exhibit a clear preference of nucleating at step edges when these edges are aligned along the [11¯0] growth direction. This suggests a promising avenue for the fabrication of regular nanowire arrays with controlled wire separation, by varying the miscut angle of the Si wafer. The nanowires are metallic and are embedded in a reconstructed Si(110)-(23×3)R54.7°-Y semiconducting surface layer.
The vibrational bound states of isomerising disilyne
Authors: Law Mark M. , Perotto Carlo U.
Published: August 2013

Full-dimensional variational calculations are reported for the isomerising disilyne molecule, Si2H2. Large-scale calculations using coordinates based on orthogonal satellite vectors permitted the computation of excited vibrational state energies and wavefunctions for all four isomeric forms: dibridged Si(H2)Si, monobridged Si(H)SiH, disilavinylidene H2SiSi, and trans-bent HSiSiH. Energies and wavefunctions have been determined for the lowest 2400 totally symmetric vibrational states; this set includes highly excited states above all three chemically relevant isomerisation barriers – up to about 8300 cm−1 above the (dibridged) ground state. States strongly localised in the dibridged, monobridged, and disilavinylidene regions of the potential energy surface have been found as well as many partially or fully delocalised states. For the trans-bent form, only partially localised states have been identified. Comparisons are made with similar literature calculations on the isovalent acetylene-vinylidene system HCCH/H2CC.
Inelastic neutron scattering spectrum of H2@C60 and its temperature dependence decoded using rigorous quantum calculations and a new selection rule
Authors: Xu Minzhong , Ye Shufeng , Powers Anna , Lawler Ronald , Turro Nicholas J. , Bačić Zlatko
Published: August 2013

In the supramolecular complex H2@C60, the lightest of molecules, H2, is encapsulated inside the most highly symmetric molecule C60. The elegance and apparent simplicity of H2@C60 conceal highly intricate quantum dynamics of the coupled translational and rotational motions of the guest molecule in a nearly spherical nanoscale cavity, which embodies some of the most fundamental concepts of quantum mechanics. Here we present the first rigorous and highly accurate quantum calculations of the inelastic neutron scattering (INS) spectra of this prototypical endohedral fullerene complex and their temperature dependence. The calculations enable complete assignment of the recently reported experimental INS spectra of H2@C60 measured at several temperatures. We also derive a new and unexpected selection rule for the INS spectroscopy of H2 in a near-spherical confinement, which explains why the INS transitions between certain translation-rotation eigenstates of H2 in C60 have zero intensity and do not appear in the spectra.
Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients
Authors: Siddiqui Sanna F. , Knipe Kevin , Manero Albert , Meid Carla , Wischek Janine , Okasinski John , Almer Jonathan , Karlsson Anette M. , Bartsch Marion , Raghavan Seetha
Published: August 2013

Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.
Solvent cavitation under solvophobic confinement
Authors: Ashbaugh Henry S.
Published: August 2013

The stability of liquids under solvophobic confinement can tip in favor of the vapor phase, nucleating a liquid-to-vapor phase transition that induces attractive forces between confining surfaces. In the case of water adjacent to hydrophobic surfaces, experimental and theoretical evidence support confinement-mediated evaporation stabilization of biomolecular and colloidal assemblies. The macroscopic thermodynamic theory of cavitation under confinement establishes the connection between the size of the confining surfaces, interfacial free energies, and bulk solvent pressure with the critical evaporation separation and interfacial forces. While molecular simulations have confirmed the broad theoretical trends, a quantitative comparison based on independent measurements of the interfacial free energies and liquid-vapor coexistence properties has, to the best of our knowledge, not yet been performed. To overcome the challenges of simulating a large number of systems to validate scaling predictions for a three-dimensional fluid, we simulate both the forces and liquid-vapor coexistence properties of a two-dimensional Lennard-Jones fluid confined between solvophobic plates over a range of plate sizes and reservoir pressures. Our simulations quantitatively agree with theoretical predictions for solvent-mediated forces and critical evaporation separations once the length dependence of the solvation free energy of an individual confining plate is taken into account. The effective solid-liquid line tension length dependence results from molecular scale correlations for solvating microscopic plates and asymptotically decays to the macroscopic value for plates longer than 150 solvent diameters. The success of the macroscopic thermodynamic theory at describing two-dimensional liquids suggests application to surfactant monolayers to experimentally confirm confinement-mediated cavitation.
Dynamics of the C/H and C/F exchanges in the reaction of 3P carbon atoms with vinyl fluoride
Authors: Lee Shih-Huang , Chen Wei-Kan , Chin Chih-Hao , Huang Wen-Jian
Published: August 2013

Two product channels C3H2F + H and C3H3 + F were identified in the reaction of C(3P) atoms with vinyl fluoride (C2H3F) at collision energy 3.7 kcal mol−1 in a crossed molecular-beam apparatus using selective photoionization. Time-of-flight (TOF) spectra of products C3H2F and C3H3 were measured at 12–16 laboratory angles as well as a TOF spectrum of atomic F, a counter part of C3H3, was recorded at single laboratory angle. From the best simulation of product TOF spectra, translational-energy distributions at seven scattering angles and a nearly isotropic (forward and backward peaked) angular distribution were derivable for exit channel C3H2F + H (C3H3 + F) that has average kinetic-energy release of 14.5 (4.9) kcal mol−1. Products C3H2F + H and C3H3 + F were estimated to have a branching ratio of ∼53:47. Furthermore, TOF spectra and photoionization spectra of products C3H2F and C3H3 were measured at laboratory angle 62° with photoionization energy ranging from 7 eV to 11.6 eV. The appearance of TOF spectra is insensitive to photon energy, implying that only single species overwhelmingly contributes to products C3H2F and C3H3. HCCCHF (H2CCCH) was identified as the dominant species based on the measured ionization threshold of 8.3 ± 0.2 (8.6 ± 0.2) eV and the maximal translational-energy release. The C/H and C/F exchange mechanisms are stated.
Observation of 3D defect mediated dust acoustic wave turbulence with fluctuating defects and amplitude hole filaments
Authors: Chang Mei-Chu , Tsai Ya-Yi , I Lin
Published: August 2013

We experimentally demonstrate the direct observation of defect mediated wave turbulence with fluctuating defects and low amplitude hole filaments, from a 3D self-excited plane dust acoustic wave in a dusty plasma by reducing dissipation. The waveform undulation is found to be the origin for the amplitude and the phase modulations of the local dust density oscillation, the broadening of the sharp peaks in the frequency spectrum, and the fluctuating defects. The corrugated wave crest surface also causes the observed high and low density patches in the transverse (xy) plane. Low oscillation amplitude spots (holes) share the same positions with the defects. Their trajectories in the xyt space appear in the form of chaotic filaments without long term predictability, through uncertain pair generation, propagation, and pair annihilation.
Ferromagnetic ordering and Griffiths-like phase behavior in Gd5Ge3.9Al0.1
Authors: Zou J. D. , Liu J. , Mudryk Y. , Pecharsky V. K. , Gschneidner K. A.
Published: August 2013

Gd5Ge3.9Al0.1 crystallizes in the Sm5Ge4-type structure at room temperature, but unlike the parent Gd5Ge4 that remains antiferromagnetic in a zero magnetic field down to at least 2 K, the ground state of the Al-substituted compound is ferromagnetic. The Curie temperature of Gd5Ge3.9Al0.1 is nearly the same as that of Gd5Ge4 in a 50 kOe magnetic field. The Griffiths-like phase behavior is observed in both Gd5Ge4 and Gd5Ge3.9Al0.1 compounds. Compared with Gd5Ge4, the Néel temperature of the aluminum-substituted compound decreases by 2 K, while the onset temperature of the Griffiths-like phase decreases by 5 K. Substitution of Al for Ge increases the magnetocaloric effect of Gd5Ge4, and the entropy change peak shifts from 41 K to 49 K.
CoTaZr/Pd multilayer with perpendicular magnetic anisotropy
Authors: Lau Yong Chang , Kurt Hüseyin , Coey J. M. D.
Published: August 2013

We report a novel perpendicularly magnetized thin film [Co91.5Ta4.5Zr4/Pd]5 multilayer, which exhibits strong perpendicular magnetic anisotropy when grown on 5 nm of Pd and Ru seed layers. The Pd-seeded multilayer annealed at 300 °C shows an effective uniaxial anisotropy constant, Keff = 1.1 MJ m−3, with an anisotropy field as high as 1.6 T. The perpendicular anisotropy is sustained on annealing at 400 °C for 1 h. X-ray diffraction on multilayers with 30 repeats suggests that the use of amorphous CoTaZr reduces the stress of the stack, compared to [Co/Pd] multilayer.
In-situ observation of nanomechanical behavior arising from critical-temperature-induced phase transformation in Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 thin film
Authors: Wang Z. M. , Cai Zh. L. , Zhao K. , Guo X. L. , Chen J. , Sun W. , Cheng Zh. X. , Kimura H. , Li B. W. , Yuan G. L. , Yin J. , Liu Zh. G.
Published: August 2013

In this Letter, we use the nanoindentation technique and vary the testing temperature to above and below critical values to study the nanomechanical features of a strong Pb-free piezoelectric Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) thin film across its piezoelectric-optimal morphotropic phase boundary. The mechanisms responsible for the Young's modulus and hardness evolution are then discussed. An X-ray diffraction method that can detect the d(110) variation associated with the change in the inclination angle ψ of the (110) plane was developed to quantify the residual stress in the BZT-0.5BCT films.
Shockwave-induced deformation of organic particles during laser shockwave cleaning
Authors: Hoon Kim Tae , Cho Hanchul , Busnaina Ahmed , Park Jin-Goo , Kim Dongsik
Published: August 2013

Although the laser shockwave cleaning process offers a promising alternative to conventional dry-cleaning processes for nanoscale particle removal, its difficulty in removing organic particles has been an unexplained problem. This work elucidates the physics underlying the ineffectiveness of removing organic particles using laser shock cleaning utilizing polystyrene latex particles on silicon substrates. It is found that the shockwave pressure is high enough to deform the particles, increasing the contact radius and consequently the particle adhesion force. The particle deformation has been verified by high-angle scanning electron microscopy. The Maugis-Pollock theory has been applied to predict the contact radius, showing good agreement with the experiment.
Perpendicular magnetic anisotropy in Ta/Co2FeAl/MgO multilayers
Authors: Gabor M. S. , Petrisor T. , Tiusan C. , Petrisor T.
Published: August 2013

In this paper, we demonstrate the stabilization of perpendicular magnetic anisotropy (PMA) in Ta/Co2FeAl/MgO multilayers sputtered on thermally oxidized Si(100) substrates. The magnetic analysis points out that these films show significant interfacial anisotropy even in the as-deposited state, KS=0.67 erg/cm2, enough to provide PMA for the as-deposited films with thicknesses below 1.5 nm. Moreover, the interfacial anisotropy is enhanced by thermal annealing up to 300 °C. The presence of a magnetic dead layer, whose thickness increases with annealing temperature, was also identified.
Dimension and liner dependent thermomechanical strain characterization of through-silicon vias using synchrotron x-ray diffraction
Authors: Liu Xi , Thadesar Paragkumar A. , Taylor Christine L. , Kunz Martin , Tamura Nobumichi , Bakir Muhannad S. , Sitaraman Suresh K.
Published: August 2013

Strain measurements are demonstrated for through-silicon vias (TSVs) using synchrotron x-ray diffraction to characterize the effect of copper via dimensions and liner materials. Reduction in strains in the silicon around TSVs is observed for the TSVs with smaller via diameters and the TSVs with a thicker polymer liner. To interpret the measured two-dimensional (2D) TSV strain distribution maps of the three-dimensional (3D) TSV strains, a data averaging method based on the energy dependent x-ray absorption is implemented along with additional considerations from the sample preparation by means of an indirect comparison methodology.
Arsenic decapping and pre-atomic layer deposition trimethylaluminum passivation of Al2O3/InGaAs(100) interfaces
Authors: Ahn Jaesoo , Kent Tyler , Chagarov Evgueni , Tang Kechao , Kummel Andrew C. , McIntyre Paul C.
Published: August 2013

The interrelated effects of initial surface preparation and precursor predosing on defect passivation of atomic layer deposited (ALD) Al2O3/InGaAs(100) interfaces are investigated. Interface trap distributions are characterized by capacitance-voltage and conductance-voltage analysis of metal-oxide-semiconductor capacitors. Thermal desorption conditions for a protective As2 layer on the InGaAs surface and dosing conditions of trimethylaluminum prior to ALD-Al2O3 are varied to alter the interface trap densities. Experimental results are consistent with the predictions of ab initio electronic structure calculations showing that trimethylaluminum dosing of the As-rich In0.53Ga0.47As(100) surface suppresses interface traps by passivating As dangling bonds prior to the initiation of Al2O3 deposition.
Strain-induced enhancement of the thermoelectric power in thin films of hole-doped La2NiO4+δ
Authors: Bach P. L. , Vila-Fungueiriño J. M. , Leborán V. , Ferreiro-Vila Elías , Rodríguez-González B. , Rivadulla F.
Published: August 2013

We propose a novel route for optimizing the thermoelectric power of a polaronic conductor, independent of its electronic conductivity. This mechanism is exemplified here in thin-films of La2NiO4+δ. Tensile stress induced by epitaxial growth on SrTiO3 doubles the thermoelectric power of ≈15 nm thick films relative to ≈90 nm films, while the electronic conductivity remains practically unchanged. Epitaxial strain influences the statistical contribution to the high temperature thermopower, but introduces a smaller correction to the electronic conductivity. This mechanism provides a new way for optimizing the high temperature thermoelectric performance of polaronic conductors.
Molecular dynamics simulations of single-layer molybdenum disulphide (MoS2): Stillinger-Weber parametrization, mechanical properties, and thermal conductivity
Authors: Jiang Jin-Wu , Park Harold S. , Rabczuk Timon
Published: August 2013

We present a parameterization of the Stillinger-Weber potential to describe the interatomic interactions within single-layer MoS2 (SLMoS2). The potential parameters are fitted to an experimentally obtained phonon spectrum, and the resulting empirical potential provides a good description for the energy gap and the crossover in the phonon spectrum. Using this potential, we perform classical molecular dynamics simulations to study chirality, size, and strain effects on the Young's modulus and the thermal conductivity of SLMoS2. We demonstrate the importance of the free edges on the mechanical and thermal properties of SLMoS2 nanoribbons. Specifically, while edge effects are found to reduce the Young's modulus of SLMoS2 nanoribbons, the free edges also reduce the thermal stability of SLMoS2 nanoribbons, which may induce melting well below the bulk melt temperature. Finally, uniaxial strain is found to efficiently manipulate the thermal conductivity of infinite, periodic SLMoS2.
Mechanism of magnetization enhancement at CoO/permalloy interfaces
Authors: Grytsyuk Sergiy , Schwingenschlögl Udo
Published: August 2013

We investigate the magnetic properties of CoO(111)/permalloy(111) interfaces by ab-initio calculations. We employ a (5 × 5)CoO/(6 × 6)permalloy supercell, to satisfy the ∼5:6 ratio of the lattice constants, and optimize the atomic density near the interface. While experimentally the interface magnetization is 14% higher than in the bulk, we find for the purely O/Co-terminated interface a decrease/increase by 140%/40%, which enables insight into the real interface with partial O deficiency and atomic intermixing. Intermixing between Fe and Ni significantly lowers the total energy, which promotes Fe accumulation at the interface. Since Co-O bonds are energetically favorable, O diffusion into the permalloy is suppressed.
Facile maskless fabrication of organic field effect transistors on biodegradable substrates
Authors: Campana Alessandra , Cramer Tobias , Greco Pierpaolo , Foschi Giulia , Murgia Mauro , Biscarini Fabio
Published: August 2013

Fabrication of a test pattern with interdigitated gold electrodes (channel length 12 μm) on a biodegradable substrate is achieved by direct laser ablation of a Au film using a high-precision multifunction infrared-laser scan marker. The whole process involves two solvent-free steps: Au film deposition by sublimation followed by maskless ablation. The approach is suited for fast prototyping of a variety of materials. We demonstrate the fabrication of a water-gated organic field effect transistor on the biodegradable poly(lactic-co-glycolic acid) scaffold and its operations in water.
Giant magnetoresistance enhancement at room-temperature in organic spin valves based on La0.67Sr0.33MnO3 electrodes
Authors: Chen B. B. , Zhou Y. , Wang S. , Shi Y. J. , Ding H. F. , Wu D.
Published: August 2013

We have systematically studied the magnetoresistance (MR) of Alq3-based organic spin valves using as-grown La0.67Sr0.33MnO3 (LSMO), annealed LSMO, and La0.67Ca0.33MnO3 as the bottom electrode. A giant enhancement of MR ratio (more than one order of magnitude) is observed when the optimal annealed LSMO is used, and the measured MR can be as high as 2.2% at room temperature. Below ∼100 K, the temperature dependence of the normalized MR is almost identical with these three electrodes despite the strong difference in Curie temperature (from 250 K to 360 K). We attribute this similar MR temperature dependence to the spin relaxation in Alq3.
N-(L-2-Aminopentanoyl)-L-phenylalanine dihydrate, a hydrophobic dipeptide with a nonproteinogenic residue
Authors: Görbitz Carl Henrik , Yadav Vitthal N.
Published: August 2013

The title dipeptide, better known as L-norvalyl-L-phenylalanine {systematic name: (S)-2-[(S)-2-aminopentanamido]-3-phenylpropanoic acid dihydrate}, C14H20N2O3·2H2O, has a nonproteinogenic N-terminal residue. In the solid state, it takes on a molecular conformation typical for one of the three classes of nanoporous dipeptides, but like two related compounds with a hydrophobic N-terminal residue and a C-terminal L-phenylalanine, it fails to form channels or pores. Instead, the crystal structure is divided into distinct hydrophobic and hydrophilic layers, the latter encompassing cocrystallized water molecules connecting the charged N- and C-terminal groups.
Role of γ‐glutamyltranspeptidase in the pathogenesis of Helicobacter pylori infection
Authors: Rimbara Emiko , Mori Shigetarou , Kim Hyun , Shibayama Keigo
Published: August 2013

γ‐Glutamyltranspeptidase and asparaginase have been shown to play important roles in Helicobacter pylori colonization and cell death induced by H. pylori infection. In this study, the association of γ‐glutamyltranspeptidase and asparaginase was elucidated by comparing activities of both deamidases in H. pylori strains from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer. γ‐Glutamyltranspeptidase activities in H. pylori strains from patients with gastric cancer were significantly higher than in those from patients with chronic gastritis or gastric ulcers. There was a wide range of asparaginase activities in H. pylori strains from patients with gastric cancer and these were not significantly than those from patients with other diseases. To identify the contributions of γ‐glutamyltranspeptidase and asparaginase to gastric cell inflammation, human gastric epithelial cells (AGS line) were infected with H. pylori wild‐type and knockout strains and inflammatory responses evaluated by induction of interleukin‐8 (IL‐8). IL‐8 response was significantly decreased by knockout of the γ‐glutamyltranspeptidase‐encoding gene but not by knockout of the asparaginase‐encoding gene. Additionally, IL‐8 induction by infection with the H. pylori wild‐type strain was significantly decreased by adding glutamine during infection. These findings indicate that IL‐8 induction caused by γ‐glutamyltranspeptidase activity in H. pylori is mainly attributable to depletion of glutamine. These data suggest that γ‐glutamyltranspeptidase plays a significant role in the chronic inflammation caused by H. pylori infection.
Distribution of antimicrobial‐resistant lactic acid bacteria in natural cheese in Japan
Authors: Ishihara Kanako , Nakajima Kumiko , Kishimoto Satoko , Atarashi Fumiaki , Muramatsu Yasukazu , Hotta Akitoyo , Ishii Satomi , Takeda Yasuyuki , Kikuchi Masanori , Tamura Yutaka
Published: August 2013

To determine and compare the extent of contamination caused by antimicrobial‐resistant lactic acid bacteria (LAB) in imported and domestic natural cheeses on the Japanese market, LAB were isolated using deMan, Rogosa and Sharpe (MRS) agar and MRS agar supplemented with six antimicrobials. From 38 imported and 24 Japanese cheeses, 409 LAB isolates were obtained and their antimicrobial resistance was tested. The percentage of LAB resistant to dihydrostreptomycin, erythromycin, and/or oxytetracycline isolated from imported cheeses (42.1%) was significantly higher than that of LAB resistant to dihydrostreptomycin or oxytetracycline from cheeses produced in Japan (16.7%; P = 0.04). Antimicrobial resistance genes were detected in Enterococcus faecalis (tetL, tetM, and ermB; tetL and ermB; tetM) E. faecium (tetM), Lactococcus lactis (tetS), Lactobacillus (Lb.), casei/paracasei (tetM or tetW), and Lb. rhamnosus (ermB) isolated from seven imported cheeses. Moreover, these E. faecalis isolates were able to transfer antimicrobial resistance gene(s). Although antimicrobial resistance genes were not detected in any LAB isolates from Japanese cheeses, Lb. casei/paracasei and Lb. coryniformis isolates from a Japanese farm‐made cheese were resistant to oxytetracycline (minimal inhibitory concentration [MIC], 32 µg/mL). Leuconostoc isolates from three Japanese farm‐made cheeses were also resistant to dihydrostreptomycin (MIC, 32 to > 512 µg/mL). In conclusion, the present study demonstrated contamination with antimicrobial‐resistant LAB in imported and Japanese farm‐made cheeses on the Japanese market, but not in Japanese commercial cheeses.
Community differentiation and population enrichment ofSargassoSea bacterioplankton in the euphotic zone of a mesoscale mode‐water eddy
Authors: Nelson Craig E. , Carlson Craig A. , Ewart Courtney S. , Halewood Elisa R.
Published: August 2013

Eddies are mesoscale oceanographic features (∼ 200 km diameter) that can cause transient blooms of phytoplankton by shifting density isoclines in relation to light and nutrient resources. To better understand how bacterioplankton respond to eddies, we examined depth‐resolved distributions of bacterial populations across an anticyclonic mode‐water eddy in theSargassoSea. Previous work on this eddy has documented elevated phytoplankton productivity and diatom abundance within the eddy centre with coincident bacterial productivity and biomass maxima. We illustrate bacterial community shifts within the eddy centre, differentiating populations uplifted along isopycnals from those enriched or depleted at horizons of enhanced bacterial and primary productivity. Phylotypes belonging to theRoseobacter,OCS116 and marineActinobacteria clades were enriched in the eddy core and were highly correlated with pigment‐based indicators of diatom abundance, supporting developing hypotheses that members of these clades associate with phytoplankton blooms. Typical mesopelagic clades (SAR202,SAR324,SAR406 andSAR11IIb) were uplifted within the eddy centre, increasing bacterial diversity in the lower euphotic zone. Typical surface oligotrophic clades (SAR116,OM75,Prochlorococcus andSAR11Ia) were relatively depleted in the eddy centre. The biogeochemical context of a bloom‐inducing eddy provides insight into the ecology of the diverse uncultured bacterioplankton dominating the oligotrophic oceans.
Leaf‐associated fungal diversity in acidified streams: insights from combining traditional and molecular approaches
Authors: Clivot Hugues , Cornut Julien , Chauvet Eric , Elger Arnaud , Poupin Pascal , Guérold François , Pagnout Christophe
Published: August 2013

We combined microscopic and molecular methods to investigate fungal assemblages on alder leaf litter exposed in the benthic and hyporheic zones of five streams across a gradient of increasing acidification for 4 weeks. The results showed that acidification and elevated Al concentrations strongly depressed sporulating aquatic hyphomycetes diversity in both zones of streams, while fungal diversity assessed by denaturing gradient gel electrophoresis (DGGE) appeared unaffected. Clone library analyses revealed that fungal communities on leaves were dominated by members of Ascomycetes and to a lesser extent by Basidiomycetes and Chytridiomycetes. An important contribution of terrestrial fungi was observed in both zones of the most acidified stream and in the hyporheic zone of the reference circumneutral stream. The highest leaf breakdown rate was observed in the circumneutral stream and occurred in the presence of both the highest diversity of sporulating aquatic hyphomycetes and the highest contribution to clone libraries of sequences affiliated with aquatic hyphomycetes. Both methods underline the major role played by aquatic hyphomycetes in leaf decomposition process. Our findings also bring out new highlights on the identity of leaf‐associated fungal communities and their responses to anthropogenic alteration of running water ecosystems.