bluuebunny/crossref_metadata_2025 huggingface dataset:
Total uterine artery blood volume flow rate in nulliparous women is associated with birth weight and gestational age at delivery
Authors: McKelvey A. , Pateman K. , Balchin I. , Peebles D. M. , Rodeck C. H. , David A. L.
Published: March 2016

Objectives

To investigate the relationship between total uterine artery blood volume flow rate (TVFR) and birth weight and gestational age at delivery, and to establish normal ranges of TVFR throughout pregnancy.

Methods

This was a prospective cohort study of 334 nulliparous women booking antenatal care at University College London Hospital between August 2008 and September 2009. Women underwent a transabdominal ultrasound examination of uterine arteries for measurement of TVFR at 12, 20 and 24 weeks' gestation. Pregnancy outcomes were recorded and linear regression was used to study the relationship between TVFR and gestational age at delivery and birth weight.

Results

A total of 551 ultrasound scans were performed. There was a significant, positive correlation between TVFR at 11–13 weeks (TVFR1) and at 22–26 weeks (TVFR3) and birth weight. For every 100‐mL/min increase in TVFR1 and TVFR3, there was an increase in birth weight of 45 g and 27 g, respectively. There was also a positive association between TVFR1 and gestational age at delivery, with a 1.4‐day increase in gestational age for every 100‐mL/min increase of TVFR1.

Conclusion

Ultrasound measurement of TVFR in the first trimester is significantly associated with both birth weight and gestational age at delivery. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
The effect of pulling speed on mechanical properties of pultruded kenaf fiber reinforced vinyl ester composites
Authors: Fairuz A.M. , Sapuan S.M. , Zainudin E.S. , Jaafar C.N.A.
Published: March 2016

During the pultrusion process, there are some parameters that influence the mechanical performance of pultruded composites. The pultruded kenaf composites processing parameter such as pulling speed influenced the pressure and curing behavior of the pultruded composites. The optimal pulling speed leads to the sufficient pressure and temperature and facilitated curing the pultruded composites. Mechanical properties such as tensile strength and modulus, flexural strength and modulus, and compressive strength of kenaf pultruded composites were analyzed in this study and the optimal pulling speed of pultruded composites was determined. The tensile strength and tensile modulus showed the optimal pulling speeds at 0.3 and 0.1 m/min, respectively, while, flexural strength, flexural modulus, and compressive strength were at 0.4, 0.2, and 0.3 m/min, respectively. Scanning electron microscopy images were utilized to study the effect of pulling speed on the morphology of the tensile fracture sample. Fiber wetting, fiber matrix adhesion, the gaps within the samples, and fiber breakages were among the phenomena occurring in the composites. J. VINYL ADDIT. TECHNOL., 24:E13–E20, 2018. © 2016 Society of Plastics Engineers
Climate change communication: what can we learn from communication theory?
Authors: Ballantyne Anne Gammelgaard
Published: March 2016

The literature on climate change communication addresses a range of issues relevant to the communication of climate change and climate science to lay audiences or publics. In doing so, it approaches this particular challenge from a variety of different perspectives and theoretical frameworks. Analyzing the body of scholarly literature on climate change communication, this article critically reviews how communication is conceptualized in the literature and concludes that the field of climate change communication is characterized by diverging and incompatible understandings of communication as a theoretical construct. In some instances, communication theory appears reduced to an ‘ad hoc’ toolbox, from which theories are randomly picked to provide studies with a fitting framework. Inspired by the paradigm shift from transmission to interaction within communication theory, potential lessons from the field of communication theory are highlighted and discussed in the context of communicating climate change. Rooted in the interaction paradigm, the article proposes a meta‐theoretical framework that conceptualizes communication as a constitutive process of producing and reproducing shared meanings. Rather than operating in separate ontological and epistemological perspectives, a meta‐theoretical conceptualization of communication would ensure a common platform that advances multiperspective argumentation and discussion of the role of climate change communication in society.WIREs Clim Change2016, 7:329–344. doi: 10.1002/wcc.392

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Communication
Tunable electronic and magnetic properties of two‐dimensional materials and their one‐dimensional derivatives
Authors: Zhang Zhuhua , Liu Xiaofei , Yu Jin , Hang Yang , Li Yao , Guo Yufeng , Xu Ying , Sun Xu , Zhou Jianxin , Guo Wanlin
Published: March 2016

Low‐dimensional materials exhibit many exceptional properties and functionalities which can be efficiently tuned by externally applied force or fields. Here we review the current status of research on tuning the electronic and magnetic properties of low‐dimensional carbon, boron nitride, metal‐dichalcogenides, phosphorene nanomaterials by applied engineering strain, external electric field and interaction with substrates, etc, with particular focus on the progress of computational methods and studies. We highlight the similarities and differences of the property modulation among one‐ and two‐dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities in typical nanostructures are also presented. Finally, prospective and challenges for applying the tunable properties into functional devices are discussed. WIREs Comput Mol Sci 2016, 6:324–350. doi: 10.1002/wcms.1251

This article is categorized under:

Structure and Mechanism > Computational Materials Science
Two Energetic Ionic Salts of en·PA·H2O and en·TNR: Preparation, Structural Characterization, and Properties
Authors: Zhang Zhi‐Bin , Yin Lei , Yin Xin , Zhang Jian‐Guo
Published: March 2016

Energetic salts of en·PA·H2O and en·TNR were synthesized by using ethylenediamine and picric acid (PA) or 2,4,6‐trinitroresorcinol (TNR) as raw materials, and their structures were characterized by elemental analysis and FT‐IR spectroscopy. Single crystals of the title salts were obtained and their structures were determined by single‐crystal X‐ray diffraction. The thermal decomposition behaviors were investigated by DSC and TG‐DTG technologies, furthermore the non‐isothermal kinetic parameters and enthalpies of formation for the salts were calculated. Their combustion heats were measured by oxygen bomb calorimetry and their enthalpies of formation were also calculated based on the combustion heat data. In addition, the detonation pressure (P) and detonation velocities (D) of the salts were predicted by using the K‐J equations. The results indicated that the title salts have potential applications in the field of energetic materials.
Asymptotic estimates of buckling radial pressure for multi‐walled carbon nanotubes at different variants of boundary conditions
Authors: Mikhasev Gennadi , Botogova Marina
Published: March 2016

Buckling of short multi‐walled carbon nanotubes (MWCNTs) under external radial pressure is studied on the base of a multiple‐shell model. The modified Mushtari‐Donell‐Vlasov type equations taking into account the van der Waals (vdW) interaction forces between adjacent tubes are used as the governing ones. In contrast to a majority of available studies on buckling of MWCNTs, which consider only the simply supported boundary conditions, this paper based on the asymptotic approach allows for the study of the buckling behavior of MWCNTs with different variants of the boundary conditions at the tube edges. At first, the pre‐buckling membrane hoop stress‐resultants induced by radial pressure are determined for each wall. Then, introducing a small parameter defined as a thickness‐to‐radius ratio, the asymptotic solutions of the boundary value problem are constructed for different cases which depend on the outermost radius of a MWCNT. The relevance of the present approach is confirmed by good agreement between asymptotic estimates and exact values of the buckling radial pressure for simply supported double‐ and triple‐walled nanotubes determined on the base of the accepted shell model. In addition, the validity of the asymptotic estimates is justified by comparing theirs with existing data obtained on the base of the available multiple‐shell model taking into account the pressure dependence of the interlayer vdW forces. The influence of the outermost radius, aspect ratio and boundary conditions as well on the buckling radial pressure is analyzed in this study.
Brief report: Benefit finding and identity processes in type 1 diabetes: Prospective associations throughout adolescence
Authors: Luyckx Koen , Ramsey Meagan A. , Kelly Caitlin S. , Wiebe Deborah J. , Mello Daniel , Oris Leen , Prikken Sofie , Verschueren Margaux , Berg Cynthia A.
Published: March 2016

Identity formation constitutes a core developmental task during adolescence, but may be challenged when having a chronic illness such as type 1 diabetes. The present study examined whether viewing positive benefits to one's diabetes across adolescence was related to greater identity exploration and commitment later in time. A total of 55 adolescents (10–14 years; 47% female) with type 1 diabetes participated in a six‐wave study spanning 3 years (with six‐month measurement intervals). Through latent growth curve modeling, Time 6 identity scores were regressed on intercept and slope terms of benefit finding through Times 1–4, simultaneously controlling for demographic and clinical variables. Identity exploration (but not commitment) at Time 6 was positively predicted by the intercept and slope of benefit finding: adolescents who find benefits in diabetes are more inclined to explore different alternatives later on in adolescence. Benefit finding may constitute a resource facilitating identity formation in adolescents with diabetes.
Sexual Practices, Fertility Intentions, and Awareness to Prevent Mother-to-Child Transmission of HIV Among Infected Pregnant Women at the Yaounde Central Hospital
Authors: Kuete Martin , Yuan Hongfang , He Qian , Tchoua Kemayou Aude Laure , Ndognjem Tita Pale , Yang Fan , Hu ZhiZong , Tian BoZhen , Zhao Kai , Zhang HuiPing , Xiong ChengLiang
Published: March 2016

Introduction

The sexual and reproductive health of people living with HIV is fundamental for their well-being. Antiretroviral therapy and reproductive technologies have significantly improved quality of life of people living with HIV in developed countries. In sub-Saharan Africa, the epicenter of HIV, the sexual practices and fertility of women infected with HIV have been understudied.

Aim

To assess the sexual behavior, fertility intentions, and awareness of preventing mother-to-child transmission of HIV in pregnant women with HIV-negative partners in Yaounde Central Hospital (Yaounde, Cameroon).

Methods

A cross-sectional survey using a semistructured, interviewer-administered questionnaire was conducted at the antenatal unit and HIV clinic in 2014.

Main Outcome Measures

Ninety-four pregnant women infected with HIV provided consistent information on (i) sociodemographic characteristics, (ii) sexual and fertility patterns, (iii) awareness of preventing mother-to-child transmission of HIV, and (iv) their unmet needs.

Results

Although sexual desire had significantly changed since their HIV diagnosis, the women were highly sexually active. Approximately 19% of women had more than one sexual partner and 40% had regular unprotected sex during the 12-month period before the interviews (P < .0001). Twenty-nine percent of women preferred intermittent sexual intercourse and inconsistent condom use to delay pregnancy, but the abortion rate remained high. Age, marital status, and education affected women's awareness of mother-to-child transmission (P < .05); and no association existed between the number of living children and future pregnancies (rs = −0.217; P = .036).

Conclusion

HIV-infected women living with HIV-negative partners in Cameroon expressed high sexual and fertility intentions with several unmet needs, including safer sexual practices and conception. Incorporating and supporting safe sexual educational practices and conception services in maternal care can decrease risky sexual behavior and vertical transmission.
Sulfiredoxin-1 protects against simulated ischaemia/reperfusion injury in cardiomyocyte by inhibiting PI3K/AKT-regulated mitochondrial apoptotic pathways
Authors: Zhang Jiankai , He Zhangyou , Guo Jinhua , Li Zhe , Wang Xiaohong , Yang Chun , Cui Xiaojun
Published: March 2016

Reactive oxygen species (ROS)-triggered cardiac cell injury is recognized as the major contributor for the pathogenesis progression of ischaemic cardiovascular diseases. Sulfiredoxin-1 (Srx-1) is an endogenous antioxidant and exerts the crucial neuroprotective effects in cerebral ischaemia. However, its function and the underlying mechanism in ischaemic heart diseases remain poorly defined. Here, a dramatical decrease in Srx-1 was validated in H9c2 cardiomyocytes upon simulated ischaemia–reperfusion (SI/R) injury. Moreover, Srx-1 protected H9c2 cells from SI/R-injured injury as the evidences that Srx-1 up-regulation attenuated the inhibitory effects on cell viability, lactate dehydrogenase (LDH) and cell apoptosis upon SI/R treatment. Knockdown of Srx-1 accelerated cell injury upon SI/R. Mechanism assay corroborated that SI/R treatment noticeably aggravated the loss of mitochondrial membrane potential (Δψm), which was remarkably abated in Ad-Srx-1 groups. Importantly, Srx-1 elevation substantially reduced cytochrome c release, the activity of caspase-9 and caspase-3, accompany with the subsequent decrease in the cleavage of poly (ADP ribose) polymerase (PARP). Concomitantly, overexpression of Srx-1 also decreased the expression of pro-apoptosis protein Bax and increased anti-apoptotic Bcl-2 expression. Further analysis substantiated that Srx-1 treatment remarkably induced the activation of PI3K/AKT signalling. Preconditioning with LY294002 dramatically decreased Srx-1-enhanced cell resistance to SI/R injury. Importantly, LY294002 mitigated the inhibitory effects of Srx-1 on Δψm loss, cytochrome c release, caspase-9/3 activity, and the expression of Bcl-2 family. Together, these results suggested that Srx-1 might protect cardiomyocyte injury upon SI/R by suppressing PI3K/AKT-mediated mitochondria dependent apoptosis, revealing a promising therapeutic agent against ischaemic cardiovascular diseases.
Cerebral blood flow regulation, exercise and pregnancy: why should we care?
Authors: Bisson Michèle , Marc Isabelle , Brassard Patrice
Published: March 2016

Cerebral blood flow (CBF) regulation is an indicator of cerebrovascular health increasingly recognized as being influenced by physical activity. Although regular exercise is recommended during healthy pregnancy, the effects of exercise on CBF regulation during this critical period of important blood flow increase and redistribution remain incompletely understood. Moreover, only a few studies have evaluated the effects of human pregnancy on CBF regulation. The present work summarizes current knowledge on CBF regulation in humans at rest and during aerobic exercise in relation to healthy pregnancy. Important gaps in the literature are highlighted, emphasizing the need to conduct well-designed studies assessing cerebrovascular function before, during and after this crucial life period to evaluate the potential cerebrovascular risks and benefits of exercise during pregnancy.
Die Rolle von Präferenzen für Langzeitpflege in der sozialen Pflegeversicherung – Ergebnisse von Experteninterviews
Authors: Heuchert M. , König H.-H. , Lehnert T.
Published: March 2016

Hintergrund: Aufgrund der Alterung der deutschen Bevölkerung wird die Zahl pflegebedürftiger Menschen in Zukunft stark zunehmen. Informationen über Präferenzen für Langzeitpflege können für Entscheidungsträger bei zukünftigen Reformen der Pflegeversicherung eine wichtige Quelle darstellen. So kann die Kenntnis von Präferenzen zu einer besseren Übereinstimmung zwischen den Wünschen und der Inanspruchnahme von Leistungen beitragen. Ziel der Studie ist es Präferenzen für Langzeitpflege mit den dahinterstehenden Gründen, als auch die Möglichkeiten individuelle Präferenzen im Rahmen der Pflegeversicherung zu realisieren, darzustellen.

Methoden: Leitfadengestützte Interviews mit 20 Experten aus dem Bereich Langzeitpflege (Pflegeversicherung) zwischen Juli und September 2014, die mit Methoden der qualitativen Inhaltsanalyse ausgewertet wurden.

Ergebnisse: Unabhängig vom Pflegearrangement präferieren Menschen eine zeitlich und organisatorisch flexible Pflege, bei der sich Autonomie und Individualität so weit wie möglich aufrechterhalten lassen. Idealerweise erfolgt die Pflege in der eigenen Häuslichkeit durch Angehörige. Daneben besitzt die Versorgung durch ambulante Pflegedienste ebenfalls eine (zunehmend) hohe Bedeutung. Stationäre Pflege wird nur sehr selten der informellen häuslichen Pflege vorgezogen. Zwischenmenschliche Bedürfnisse spielen für die meisten Pflegebedürftigen eine größere Rolle als rein körperbezogene und fachliche Aspekte der Pflege.

Schlussfolgerung: Während die flexiblen Wahl- und Kombinationsmöglichkeiten der Pflegeversicherung eine wichtige Grundlage zur Realisierung individueller Präferenzen darstellen, steht die fehlende frühzeitige Auseinandersetzung mit dem Thema einer bedarfs- und präferenzgerechten Pflege vielfach entgegen.
Three-dimensional interaction of a finite-span synthetic jet in a crossflow
Authors: Van Buren Tyler , Beyar Michael , Leong Chia Min , Amitay Michael
Published: March 2016

The formation and evolution of flow structures due to the interaction of a finite-span synthetic jet with a zero-pressure gradient laminar boundary layer were experimentally investigated using stereoscopic particle image velocimetry. A synthetic jet with three orifice aspect ratios of AR = 6, 12, and 18 was issued into a free-stream velocity of U∞ = 10 m/s (Reδ = 2000) at blowing ratios of Cb = 0.5–1.5. The interaction was found to be associated with two sets of flow structures: (1) a recirculation region downstream of the orifice due to virtual blockage, and (2) a steady streamwise vortex pair farther downstream. These two flow structures were characterized in detail. Tube-like velocity deficits in the free-stream were evident, as well as regions of increased velocity within the boundary layer. Reducing the aspect ratio of the orifice decreased the spacing of the edgewise vortices (generated due to the finite span of the orifice) as well as reducing the virtual blockage of the jet. A control volume analysis of the fluid streamwise momentum indicates that there is a momentum deficit just downstream of the jet orifice and the change in streamwise momentum is proportionally similar for all cases.
Laminar and turbulent flows over hydrophobic surfaces with shear-dependent slip length
Authors: Khosh Aghdam Sohrab , Ricco Pierre
Published: March 2016

Motivated by extensive discussion in the literature, by experimental evidence and by recent direct numerical simulations, we study flows over hydrophobic surfaces with shear-dependent slip lengths and we report their drag-reduction properties. The laminar channel-flow and pipe-flow solutions are derived and the effects of hydrophobicity are quantified by the decrease of the streamwise pressure gradient for constant mass flow rate and by the increase of the mass flow rate for constant streamwise pressure gradient. The nonlinear Lyapunov stability analysis, first applied to a two-dimensional channel flow by Balogh et al. [“Stability enhancement by boundary control in 2-D channel flow,” IEEE Trans. Autom. Control 46, 1696-1711 (2001)], is employed on the three-dimensional channel flow with walls featuring shear-dependent slip lengths. The feedback law extracted through the stability analysis is recognized for the first time to coincide with the slip-length model used to represent the hydrophobic surfaces, thereby providing a precise physical interpretation for the feedback law advanced by Balogh et al. The theoretical framework by Fukagata et al. [“A theoretical prediction of friction drag reduction in turbulent flow by superhydrophobic surfaces,” Phys. Fluids 18, 051703 (2006)] is employed to model the drag-reduction effect engendered by the shear-dependent slip-length surfaces and the theoretical drag-reduction values are in very good agreement with our direct numerical simulation data. The turbulent drag reduction is measured as a function of the hydrophobic-surface parameters and is found to be a function of the time- and space-averaged slip length, irrespective of the local and instantaneous slip behaviour at the wall. For slip parameters and flow conditions that could be realized in the laboratory, the maximum computed turbulent drag reduction is 50% and the drag reduction effect degrades when slip along the spanwise direction is considered. The power spent by the turbulent flow on the hydrophobic walls is computed for the first time and is found to be a non-negligible portion of the power saved through drag reduction, thereby recognizing the hydrophobic surfaces as a passive-absorbing drag-reduction method. The turbulent flow is further investigated through flow visualizations and statistics of the relevant quantities, such as vorticity and strain rates. When rescaled in drag-reduction viscous units, the streamwise vortices over the hydrophobic surface are strongly altered, while the low-speed streaks maintain their characteristic spanwise spacing. We finally show that the reduction of vortex stretching and enstrophy production is primarily caused by the eigenvectors of the strain rate tensor orienting perpendicularly to the vorticity vector.
Block-diagonalization as a tool for the robust diabatization of high-dimensional potential energy surfaces
Authors: Venghaus Florian , Eisfeld Wolfgang
Published: March 2016

Robust diabatization techniques are key for the development of high-dimensional coupled potential energy surfaces (PESs) to be used in multi-state quantum dynamics simulations. In the present study we demonstrate that, besides the actual diabatization technique, common problems with the underlying electronic structure calculations can be the reason why a diabatization fails. After giving a short review of the theoretical background of diabatization, we propose a method based on the block-diagonalization to analyse the electronic structure data. This analysis tool can be used in three different ways: First, it allows to detect issues with the ab initio reference data and is used to optimize the setup of the electronic structure calculations. Second, the data from the block-diagonalization are utilized for the development of optimal parametrized diabatic model matrices by identifying the most significant couplings. Third, the block-diagonalization data are used to fit the parameters of the diabatic model, which yields an optimal initial guess for the non-linear fitting required by standard or more advanced energy based diabatization methods. The new approach is demonstrated by the diabatization of 9 electronic states of the propargyl radical, yielding fully coupled full-dimensional (12D) PESs in closed form.
Nonlinear evolution of the Kelvin-Helmholtz instability in the double current sheet configuration
Authors: Mao Aohua , Li Jiquan , Liu Jinyuan , Kishimoto Yasuaki
Published: March 2016

The nonlinear evolution of the Kelvin-Helmholtz (KH) instability driven by a radially antisymmetric shear flow in the double current sheet configuration is numerically investigated based on a reduced magnetohydrodynamic model. Simulations reveal different nonlinear fate of the KH instability depending on the amplitude of the shear flow, which restricts the strength of the KH instability. For strong shear flows far above the KH instability threshold, the linear electrostatic-type KH instability saturates and achieves a vortex flow dominated quasi-steady state of the electromagnetic (EM) KH turbulence with large-amplitude zonal flows as well as zonal fields. The magnetic surfaces are twisted significantly due to strong vortices but without the formation of magnetic islands. However, for the shear flow just over the KH instability threshold, a weak EM-type KH instability is saturated and remarkably damped by zonal flows through modifying the equilibrium shear flow. Interestingly, a secondary double tearing mode (DTM) is excited subsequently in highly damped KH turbulence, behaving as a pure DTM in a flowing plasma as described in Mao et al. [Phys. Plasmas 21, 052304 (2014)]. However, the explosive growth phenomenon is replaced by a gradually growing oscillation due to the extremely twisted islands. As a result, the release of the magnetic energy becomes slow and the global magnetic reconnection tends to be gentle. A complex nonlinear interaction between the EM KH turbulence and the DTMs occurs for the medium shear flows above the KH instability threshold, turbulent EM fluctuations experience oscillatory nonlinear growth of the DTMs, finally achieves a quasi-steady state with the interplay of the fluctuations between the DTMs and the EM KH instability.
Evolutionary geometry of Lagrangian structures in a transitional boundary layer
Authors: Zheng Wenjie , Yang Yue , Chen Shiyi
Published: March 2016

We report a geometric study of Lagrangian structures in a weakly compressible, spatially evolving transitional boundary layer at the Mach number 0.7. The Lagrangian structures in the transition process are extracted from the Lagrangian scalar field by a sliding window filter at a sequence of reference times. The multi-scale and multi-directional geometric analysis is applied to characterize the geometry of spatially evolving Lagrangian structures, including the averaged inclination and sweep angles at different scales ranging from one half of the boundary layer thickness to several viscous length scales. Here, the inclination angle is on the plane of the streamwise and wall-normal directions, and the sweep angle is on the plane of the streamwise and spanwise directions. In general, the averaged inclination angle is increased and the sweep angle is decreased with the reference time. The variation of the angles for large-scale structures is smaller than that for small-scale structures. Before the transition, the averaged inclination and sweep angles are only slightly altered for all the scales. As the transition occurs, averaged inclination angles increase and sweep angles decrease rapidly for small-scale structures. In the late transitional stage, the averaged inclination angle of small-scale structures with 30 viscous length scales is approximately 42°, and the averaged sweep angle in the logarithm law region is approximately 30°. Additionally, the geometry of Lagrangian structures in transitional boundary layer flow is compared with that in the fully developed turbulent channel flow.
Effects of rapid thermal annealing on two-dimensional delocalized electronic states of the epitaxial N δ-doped layer in GaAs
Authors: Ogawa Yasuhiro , Harada Yukihiro , Baba Takeshi , Kaizu Toshiyuki , Kita Takashi
Published: March 2016

We have conducted rapid thermal annealing (RTA) for improving the two-dimensional (2D) arrangement of electronic states in the epitaxial nitrogen (N) δ-doped layer in GaAs. RTA rearranged the N-pair configurations in the GaAs (001) plane and reduced the number of non-radiative recombination centers. Furthermore, a Landau shift, representing the 2D delocalized electronic states in the (001) plane, was observed at around zero magnetic field intensity in the Faraday configuration.
Origin of selenium–gold interaction in F2CSe⋯AuY (Y = CN, F, Cl, Br, OH, and CH3): Synergistic effects
Authors: Guo Xin , Yang Yu-Ping , Li Qing-Zhong , Li Hai-Bei
Published: March 2016

Selenium–gold interaction plays an important role in crystal materials, molecular self-assembly, and pharmacochemistry involving gold. In this paper, we unveiled the mechanism and nature of selenium–gold interaction by studying complexes F2CSe⋯AuY (Y = CN, F, Cl, Br, OH, and CH3). The results showed that the formation of selenium–gold interaction is mainly attributed to the charge transfer from the lone pair of Se atom to the Au—Y anti-bonding orbital. Energy decomposition analysis indicated that the polarization energy is nearly equivalent to or exceeds the electrostatic term in the selenium–gold interaction. Interestingly, the chalcogen–gold interaction becomes stronger with the increase of chalcogen atomic mass in F2CX⋯AuCN (X = O, S, Se, and Te). The cyclic ternary complexes are formed with the introduction of NH3 into F2CSe⋯AuY, in which selenium–gold interaction is weakened and selenium–nitrogen interaction is strengthened due to the synergistic effects.
Twisted Landau damping rates in multi-component dusty plasmas
Authors: Ali S. , Bukhari S. , Mendonca J. T.
Published: March 2016

Keeping in view the kinetic treatment for plasma particles, the electrostatic twisted dust-acoustic (DA) and dust-ion-acoustic (DIA) waves are investigated in a collisionless unmagnetized multi-component dusty plasma, whose constituents are the electrons, singly ionized positive ions, and negatively charged massive dust particulates. With this background, the Vlasov–Poisson equations are coupled together to derive a generalized dielectric constant by utilizing the Laguerre-Gaussian perturbed distribution function and electrostatic potential in the paraxial limit. The dispersion and damping rates of twisted DA and DIA waves are analyzed with finite orbital angular momentum states in a multi-component dusty plasma. Significant modifications concerning the real wave frequencies and damping rates appeared with varying twisted dimensionless parameter and dust concentration. In particular, it is shown that dust concentration enhances the phase speed of the DIA waves in contrary to DA waves, whereas the impact of twisted parameter reduces the frequencies of both DA and DIA waves. The results should be useful for the understanding of particle transport and trapping phenomena caused by wave excitation in laboratory dusty plasmas.
Space charge limited current mechanism in Bi2S3 nanowires
Authors: Kunakova Gunta , Viter Roman , Abay Simon , Biswas Subhajit , Holmes Justin D. , Bauch Thilo , Lombardi Floriana , Erts Donats
Published: March 2016

We report on the charge transport properties of individual Bi2S3 nanowires grown within the pores of anodized aluminum oxide templates. The mean pore diameter was 80 nm. Space charge limited current is the dominating conduction mechanism at temperatures below 160 K. Characteristic parameters of nanowires, such as trap concentration and trap characteristic energy, were estimated from current–voltage characteristics at several temperatures.
Temperature dependence of the photoluminescence polarization of ordered III-V semiconductor alloys
Authors: Prutskij T. , Makarov N. , Attolini G.
Published: March 2016

We studied the linear polarization of the photoluminescence (PL) emission of atomically ordered GaInAsP and GaInP alloys with different ordering parameters in the temperature range from 10 to 300 K. The epitaxial layers of these alloys were grown on GaAs and Ge (001) substrates by metal organic vapor phase epitaxy. The polarization of the PL emission propagating along different crystallographic axes depends on the value of biaxial strain in the layer and changes with temperature. We calculated the PL polarization patterns for different propagation directions as a function of biaxial strain using an existing model developed for ternary atomically ordered III-V alloys. Comparing the calculated PL polarization patterns with those obtained experimentally, we separated the variation of the PL polarization due to change of biaxial strain with temperature.
Note: Dynamic meso-scale full field surface deformation measurement of heterogeneous materials
Authors: Ravindran S. , Tessema A. , Kidane A.
Published: March 2016

A dynamic experiment at mesoscale is developed to measure local deformation and strain in granular materials at high temporal and spatial resolutions. The experimental setup is comprised of a high-speed camera along with a high magnification extension tube. The method is demonstrated by measuring the full field strain across and in the boundary of the crystals at a high temporal resolution in polymer bonded sugar crystals and glass beads filled epoxy particulate composite specimens under dynamic loading. In both cases, the local strain heterogeneity is captured successfully. The measured strain and deformation field can be further used to obtain the relative motion of each crystal, crystal rotation, and the relative displacement between the polymer interface and the crystal, which are very critical to understand the local failure mechanisms in heterogeneous materials.
Generation of quasi-monoenergetic protons from a double-species target driven by the radiation pressure of an ultraintense laser pulse
Authors: Pae Ki Hong , Kim Chul Min , Nam Chang Hee
Published: March 2016

In laser-driven proton acceleration, generation of quasi-monoenergetic proton beams has been considered a crucial feature of the radiation pressure acceleration (RPA) scheme, but the required difficult physical conditions have hampered its experimental realization. As a method to generate quasi-monoenergetic protons under experimentally viable conditions, we investigated using double-species targets of controlled composition ratio in order to make protons bunched in the phase space in the RPA scheme. From a modified optimum condition and three-dimensional particle-in-cell simulations, we showed by varying the ion composition ratio of proton and carbon that quasi-monoenergetic protons could be generated from ultrathin plane targets irradiated with a circularly polarized Gaussian laser pulse. The proposed scheme should facilitate the experimental realization of ultrashort quasi-monoenergetic proton beams for unique applications in high field science.
Inferring gene targets of drugs and chemical compounds from gene expression profiles
Authors: Noh Heeju , Gunawan Rudiyanto
Published: March 2016

Motivation: Finding genes which are directly perturbed or targeted by drugs is of great interest and importance in drug discovery. Several network filtering methods have been created to predict the gene targets of drugs from gene expression data based on an ordinary differential equation model of the gene regulatory network (GRN). A critical step in these methods involves inferring the GRN from the expression data, which is a very challenging problem on its own. In addition, existing network filtering methods require computationally intensive parameter tuning or expression data from experiments with known genetic perturbations or both.

Results: We developed a method called DeltaNet for the identification of drug targets from gene expression data. Here, the gene target predictions were directly inferred from the data without a separate step of GRN inference. DeltaNet formulation led to solving an underdetermined linear regression problem, for which we employed least angle regression (DeltaNet-LAR) or LASSO regularization (DeltaNet-LASSO). The predictions using DeltaNet for expression data of Escherichia coli , yeast, fruit fly and human were significantly more accurate than those using network filtering methods, namely mode of action by network identification (MNI) and sparse simultaneous equation model (SSEM). Furthermore, DeltaNet using LAR did not require any parameter tuning and could provide computational speed-up over existing methods.

Conclusion: DeltaNet is a robust and numerically efficient tool for identifying gene perturbations from gene expression data. Importantly, the method requires little to no expert supervision, while providing accurate gene target predictions.

Availability and implementation: DeltaNet is available on http://www.cabsel.ethz.ch/tools/DeltaNet .

Contact:  rudi.gunawan@chem.ethz.ch

Supplementary information:  Supplementary data are available at Bioinformatics online.
Cuticular bacteria appear detrimental to social spiders in mixed but not
monoculture exposure
Authors: Keiser Carl N. , Shearer Taylor A. , DeMarco Alexander E. , Brittingham Hayley A. , Knutson Karen A. , Kuo Candice , Zhao Katherine , Pruitt Jonathan N.
Published: March 2016

Much of an animal’s health status, life history, and behavior are dictated by interactions with its endogenous and exogenous bacterial communities. Unfortunately, interactions between hosts and members of their resident bacterial community are often ignored in animal behavior and behavioral ecology. Here, we aim to identify the nature of host–microbe interactions in a nonmodel organism, the African social spider Stegodyphus dumicola. We collected and identified bacteria from the cuticles of spiders in situ and then exposed spiders to bacterial monocultures cultures via topical application or injection. We also topically inoculated spiders with a concomitant “cocktail” of bacteria and measured the behavior of spiders daily for 24 days after inoculation. Lastly, we collected and identified bacteria from the cuticles of prey items in the capture webs of spiders, and then fed spiders domestic crickets which had been injected with these bacteria. We also injected 1 species of prey-borne bacteria into the hemolymph of spiders. Only Bacillus thuringiensis caused increased mortality when injected into the hemolymph of spiders, whereas no bacterial monocultures caused increased mortality when applied topically, relative to control solutions. However, a bacterial cocktail of cuticular bacteria caused weight loss and mortality when applied topically, yet did not detectibly alter spider behavior. Consuming prey injected with prey-borne bacteria was associated with an elongated lifespan in spiders. Thus, indirect evidence from multiple experiments suggests that the effects of these bacteria on spider survivorship appear contingent on their mode of colonization and whether they are applied in monoculture or within a mixed cocktail. We urge that follow-up studies should test these host–microbe interactions across different social contexts to determine the role that microbes play in colony performance.
Leveraging a Redesigned Morbidity and Mortality Conference That Incorporates the Clinical and Educational Missions of Improving Quality and Patient Safety
Authors: Tad-y Darlene B. , Pierce Read G. , Pell Jonathan M. , Stephan Lindsie , Kneeland Patrick P. , Wald Heidi L.
Published: March 2016

Problem

The morbidity and mortality (M&M) conference is a vital event that can affect medical education, quality improvement, and peer review in academic departments. Historically, M&M conferences have emphasized cases that highlight diagnostic uncertainty or complex management conundrums. In this report, the authors describe the development, pilot, and refinement of a systems-based M&M conference model that combines the educational and clinical missions of improving quality and patient safety in the University of Colorado Department of Medicine.

Approach

In 2011, a focused taskforce completed a literature review that informed the development of a framework for the redesigned systems-based M&M conference. The new model included a restructured monthly conference, longitudinal curriculum for residents, and formal channels for interaction with clinical effectiveness departments. Each conference features an in-depth discussion of an adverse event using specific quality improvement tools. Areas for improvement and suggested action items are identified during the conference and delegated to the relevant clinical departments.

Outcomes

The new process has enabled the review of 27 adverse events over two years. Sixty-three action items were identified, and 33 were pursued. An average of 50 to 60 individuals participate in each conference, including interprofessional and interdisciplinary colleagues. Resident and faculty feedback regarding the new format has been positive, and other departments are starting to adopt this model.

Next Steps

A more robust process for identifying and selecting cases to discuss is needed, as is a stable, sufficient mechanism to manage the improvement initiatives that come out of each conference.
Control of Respiratory Drive and Effort in Extracorporeal Membrane Oxygenation Patients Recovering from Severe Acute Respiratory Distress Syndrome
Authors: Mauri Tommaso , Grasselli Giacomo , Suriano Grazia , Eronia Nilde , Spadaro Savino , Turrini Cecilia , Patroniti Nicolo’ , Bellani Giacomo , Pesenti Antonio
Published: March 2016

AbstractAbstract

Patients recovering from severe acute respiratory distress syndrome on extracorporeal membrane oxygenation while receiving ventilator support developed lower tidal volume and transpulmonary pressure when extracorporeal carbon dioxide extraction was increased and Paco
2 levels decreased. This suggests a mechanism for lessening lung injury in spontaneously breathing patients on extracorporeal membrane oxygenation.

Background

The amount of extracorporeal carbon dioxide removal may influence respiratory drive in acute respiratory distress syndrome (ARDS) patients undergoing extracorporeal membrane oxygenation (ECMO). The authors evaluated the effects of different levels of extracorporeal carbon dioxide removal in patients recovering from severe ARDS undergoing pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA).

Methods

The authors conducted a prospective, randomized, crossover study on eight spontaneously breathing ARDS patients undergoing venovenous ECMO since 28 ± 20 days. To modulate carbon dioxide extraction, ECMO gas flow (GF) was decreased from baseline resting protective conditions (i.e., GF100%, set to obtain pressure generated in the first 100 ms of inspiration against an occluded airway less than 2 cm H2O, respiratory rate less than or equal to 25 bpm, tidal volume less than 6 ml/kg, and peak airway pressure less than 25 cm H2O) to GF50%-GF25%-GF0% during both PSV and NAVA (random order for ventilation mode). Continuous recordings of airway pressure and flow and esophageal pressure were obtained and analyzed during all study phases.

Results

At higher levels of extracorporeal carbon dioxide extraction, pressure generated in the first 100 ms of inspiration against an occluded airway decreased from 2.8 ± 2.7 cm H2O (PSV, GF0%) and 3.0 ± 2.1 cm H2O (NAVA, GF0%) to 0.9 ± 0.5 cm H2O (PSV, GF100%) and 1.0 ± 0.8 cm H2O (NAVA, GF100%; P < 0.001) and patients’ inspiratory muscle pressure passed from 8.5 ± 6.3 and 6.5 ± 5.5 cm H2O to 4.5 ± 3.1 and 4.2 ± 3.7 cm H2O (P < 0.001). In time, decreased inspiratory drive and effort determined by higher carbon dioxide extraction led to reduction of tidal volume from 6.6 ± 0.9 and 7.5 ± 1.2 ml/kg to 4.9 ± 0.8 and 5.3 ± 1.3 ml/kg (P < 0.001) and of peak airway pressure from 21 ± 3 and 25 ± 4 cm H2O to 21 ± 3 and 21 ± 5 cm H2O (P < 0.001). Finally, transpulmonary pressure linearly decreased when the amount of carbon dioxide extracted by ECMO increased (R2 = 0.823, P < 0.001).

Conclusions

In patients recovering from ARDS undergoing ECMO, the amount of carbon dioxide removed by the artificial lung may influence spontaneous breathing. The effects of carbon dioxide removal on spontaneous breathing during the earlier acute phases of ARDS remain to be elucidated.
The Influence of Linguistic Proficiency on Masked Text Recognition Performance in Adults With and Without Congenital Hearing Impairment
Authors: Huysmans Elke , Bolk Elske , Zekveld Adriana A. , Festen Joost M. , de Groot Annette M. B. , Goverts S. Theo
Published: March 2016

Objective:

The authors first examined the influence of moderate to severe congenital hearing impairment (CHI) on the correctness of samples of elicited spoken language. Then, the authors used this measure as an indicator of linguistic proficiency and examined its effect on performance in language reception, independent of bottom-up auditory processing.

Design:

In groups of adults with normal hearing (NH, n = 22), acquired hearing impairment (AHI, n = 22), and moderate to severe CHI (n = 21), the authors assessed linguistic proficiency by analyzing the morphosyntactic correctness of their spoken language production. Language reception skills were examined with a task for masked sentence recognition in the visual domain (text), at a readability level of 50%, using grammatically correct sentences and sentences with distorted morphosyntactic cues. The actual performance on the tasks was compared between groups.

Results:

Adults with CHI made more morphosyntactic errors in spoken language production than adults with NH, while no differences were observed between the AHI and NH group. This outcome pattern sustained when comparisons were restricted to subgroups of AHI and CHI adults, matched for current auditory speech reception abilities. The data yielded no differences between groups in performance in masked text recognition of grammatically correct sentences in a test condition in which subjects could fully take advantage of their linguistic knowledge. Also, no difference between groups was found in the sensitivity to morphosyntactic distortions when processing short masked sentences, presented visually.

Conclusions:

These data showed that problems with the correct use of specific morphosyntactic knowledge in spoken language production are a long-term effect of moderate to severe CHI, independent of current auditory processing abilities. However, moderate to severe CHI generally does not impede performance in masked language reception in the visual modality, as measured in this study with short, degraded sentences. Aspects of linguistic proficiency that are affected by CHI thus do not seem to play a role in masked sentence recognition in the visual modality.
Determinants of Functional Outcome in Distal Radius Fractures in High-Functioning Patients Older Than 55 Years
Authors: Larouche Jeremie , Pike Jeffrey , Slobogean Gerard P. , Guy Pierre , Broekhuyse Henry , O'Brien Peter , Lefaivre Kelly A.
Published: March 2016

Objectives:

To determine the influence of treatment and radiographic parameters on patient-reported functional outcomes on a population of non-frail elderly with distal radius fractures.

Design:

Prospective cohort study.

Setting:

Level 1 trauma center.

Patients/Participants:

Patients older than 55 years presenting with a distal radius fracture and a Canadian Study of Health and Aging Clinical Frailty Scale score of 1 or 2.

Intervention:

Closed reduction and casting or open reduction and internal fixation as per the treating surgeons' decision.

Main Outcome Measures:

Radiographic scores at baseline, 6 weeks, and 12 weeks, as well as Disabilities of the Arm, Shoulder and Hand, Short Form 36, and Patient-Reported Wrist Evaluation scores up to 1 year after injury. Univariate analysis and linear regression analysis were performed on outcome measures.

Results:

No difference exists in outcomes based on treatment choice. Patients with ulnar positivity greater than 2 mm at baseline, after treatment, and at final follow-up had worse patient-reported scores at 1 year. Persistent articular gaps and/or steps greater than 2 mm after treatment were also associated with worse patient-reported outcomes.

Conclusion:

Even in high-functioning patients older than 55 years, there was no difference in patient-reported outcomes at 1 year in the open reduction group as compared with the closed reduction group. Instead, physicians should pay particular attention to radial shortening and persistent articular gaps following their chosen treatment plan for distal radial fractures.

Level of Evidence:

Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.