bluuebunny/crossref_metadata_2025_split huggingface dataset:
First‐principle study of electronic structures of multi‐layer graphenes
Authors: Li M. M. , Zhang J. , Li F. J. , Zhu F. X. , Zhang M. , Zhao X. F. 
Published: April 2009

AbstractEnergetic evaluation of possible stacking structures of monolayer, bi‐layer and tri‐layer graphene crystals has been performed using the density‐functional theory under the local density approximation AA stacking of carbon hexagonal monolayer and graphite with AB stacking was also discussed for the reference. It was shown that multi‐layer graphenes are direct band‐gap semiconductors, and the width of their band gaps of graphene crystals can be adjusted by changing the number of graphene layers. The property of band structures of multi‐layer graphenes suggests the potential application for solar cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Barotropic instability in the tropical cyclone outer region
Authors: Peng Jiayi , Li Tim , Peng Melinda S. , Ge Xuyang 
Published: April 2009

AbstractThe growth of asymmetric perturbations and their interactions with the symmetric flow are investigated for wind profiles in a tropical cyclone with instability in its outer region. Three tangential wind profiles are examined: TC1, a strong barotropic instability profile in the outer region; TC2, a stable wind profile; and TC3, a weaker instability profile comparing to TC1 with a larger distance between the inner negative and the outer positive vorticity gradient centres.An eigenvalue analysis indicates that azimuthal wave‐number two is the most unstable mode in both TC1 and TC3, with an e‐folding time‐scale of about 1 and 9 days, respectively. Numerical simulations using a linear barotropic model, with an initial asymmetry specified in the outer region, confirm the eigenvalue analysis. A mechanism is provided to explain the difference between simulations in TC1 and TC2. In both the stable and unstable case, an inner asymmetry is induced by the initial outer asymmetry acting on the symmetric vorticity gradient. Subsequently, the newly generated inner asymmetry feeds back positively to the outer asymmetry with the unstable profile. Because of this positive feedback, the inner and the outer asymmetries maintain an up‐shear phase tilting, leading to a continuous energy transfer from the symmetric flow to the asymmetric perturbation. In the stable TC2, the inner asymmetry could not amplify the outer initial asymmetry as there is no basic‐state radial vorticity gradient there. Also due to this feedback process, disturbances grow faster where the (absolute) basic‐state vorticity gradients are large. Therefore, the position of an initial disturbance plays a minor role in determining the outcome of the system.Simulations with a nonlinear barotropic model and a primitive equation model further confirm the significant weakening of the maximum tangential wind due to the positive feedback process in TC1. Simulations for TC3 show a smaller change of the symmetric tangential wind, as expected. Copyright © 2009 Royal Meteorological Society
Common predictor effects for multivariate longitudinal data
Authors: Jia Juan , Weiss Robert E. 
Published: April 2009

AbstractMultivariate outcomes measured longitudinally over time are common in medicine, public health, psychology and sociology. The typical (saturated) longitudinal multivariate regression model has a separate set of regression coefficients for each outcome. However, multivariate outcomes are often quite similar and many outcomes can be expected to respond similarly to changes in covariate values. Given a set of outcomes likely to share common covariate effects, we propose the clustered outcome common predictor effect model and offer a two step iterative algorithm to fit the model using available software for univariate longitudinal data. Outcomes that share predictor effects need not be chosen a priori; we propose model selection tools to let the data select outcome clusters. We apply the proposed methods to psychometric data from adolescent children of HIV+ parents. Copyright © 2009 John Wiley & Sons, Ltd.
Improving Biocompatibility of Implantable Metals by Nanoscale Modification of Surfaces: An Overview of Strategies, Fabrication Methods, and Challenges
Authors: Variola Fabio , Vetrone Fiorenzo , Richert Ludovic , Jedrzejowski Pawel , Yi Ji‐Hyun , Zalzal Sylvia , Clair Sylvain , Sarkissian Andranik , Perepichka Dmitrii F. , Wuest James D. , Rosei Federico , Nanci Antonio 
Published: April 2009

AbstractThe human body is an intricate biochemical–mechanical system, with an exceedingly precise hierarchical organization in which all components work together in harmony across a wide range of dimensions. Many fundamental biological processes take place at surfaces and interfaces (e.g., cell–matrix interactions), and these occur on the nanoscale. For this reason, current health‐related research is actively following a biomimetic approach in learning how to create new biocompatible materials with nanostructured features. The ultimate aim is to reproduce and enhance the natural nanoscale elements present in the human body and to thereby develop new materials with improved biological activities. Progress in this area requires a multidisciplinary effort at the interface of biology, physics, and chemistry. In this Review, the major techniques that have been adopted to yield novel nanostructured versions of familiar biomaterials, focusing particularly on metals, are presented and the way in which nanometric surface cues can beneficially guide biological processes, exerting influence on cellular behavior, is illustrated.Frontispiece adapted from Reference 94.magnified image
Nanoporous Polymers for Hydrogen Storage
Authors: Germain Jonathan , Fréchet Jean M. J. , Svec Frantisek 
Published: April 2009

AbstractThe design of hydrogen storage materials is one of the principal challenges that must be met before the development of a hydrogen economy. While hydrogen has a large specific energy, its volumetric energy density is so low as to require development of materials that can store and release it when needed. While much of the research on hydrogen storage focuses on metal hydrides, these materials are currently limited by slow kinetics and energy inefficiency. Nanostructured materials with high surface areas are actively being developed as another option. These materials avoid some of the kinetic and thermodynamic drawbacks of metal hydrides and other reactive methods of storing hydrogen. In this work, progress towards hydrogen storage with nanoporous materials in general and porous organic polymers in particular is critically reviewed. Mechanisms of formation for crosslinked polymers, hypercrosslinked polymers, polymers of intrinsic microporosity, and covalent organic frameworks are discussed. Strategies for controlling hydrogen storage capacity and adsorption enthalpy via manipulation of surface area, pore size, and pore volume are discussed in detail.magnified image
Behavioral abnormalities in synapsin II knockout mice implicate a causal factor in schizophrenia
Authors: Dyck Bailee A. , Skoblenick Kevin J. , Castellano Jessica M. , Ki Kitty , Thomas Nancy , Mishra Ram K. 
Published: April 2009

AbstractRecent studies on the phosphoprotein synapsin II have revealed reduced expression in postmortem medial prefrontal cortex tissues from subjects with schizophrenia, and chronic antipsychotic drug treatment has resulted in concurrent increases in synapsin II mRNA and protein levels. Collectively, this research suggests a role of synapsin II in the pathophysiology of schizophrenia; however, whether synapsin II plays a causal role in this disease process still remains unclear. Therefore, the goal of this investigation was to examine whether synapsin II knockout mice display behavioral abnormalities commonly expressed in preclinical animal models of schizophrenia, namely deficits in prepulse inhibition (PPI), decreased social behavior, and locomotor hyperactivity. Results indicate that mice with knockout of the synapsin II gene demonstrate deficits in PPI at three prepulse intensities (67, 70, and 73 dB), along with deficits in habituation to startle to a 110 dB acoustic pulse. Knockout animals also expressed decreased social behavior and increased locomotor activity when compared to wildtype and heterozygous populations. Complete knockout of the synapsin II gene was confirmed in postmortem brain tissues via immunoblotting. In conclusion, these results confirm that synapsin II knockout mice display behavioral endophenotypes similar to established preclinical animal models of schizophrenia, and lend support to the notion that abnormalities in synapsin II expression may play a causal role in the underlying pathophysiological mechanisms of schizophrenia. Synapse 63:662–672, 2009. © 2009 Wiley‐Liss, Inc.
Impact of audit of routine second‐trimester cardiac images using a novel image‐scoring method
Authors: Sairam S. , Awadh A. M. A. , Cook K. , Papageorghiou A. T. , Carvalho J. S. 
Published: April 2009

AbstractObjectiveTo assess the impact of using an objective scoring method to audit cardiac images obtained as part of the routine 21–23‐week anomaly scan.MethodsA prospective audit and re‐audit (6 months later) were conducted on cardiac images obtained by sonographers during the routine anomaly scan. A new image‐scoring method was devised based on expected features in the four‐chamber and outflow tract views. For each patient, scores were awarded for documentation and quality of individual views. These were called ‘Documentation Scores’ and ‘View Scores’ and were added to give a ‘Patient Score’ which represented the quality of screening provided by the sonographer for that particular patient (maximum score, 15). In order to assess the overall performance of sonographers, an ‘Audit Score’ was calculated for each by averaging his or her Patient Scores. In addition, to assess each sonographer's performance in relation to particular aspects of the various views, each was given their own ‘Sonographer View Scores’, derived from image documentation and details of four‐chamber view (magnification, valve offset and septum) and left and right outflow tract views. All images were scored by two reviewers, jointly in the primary audit and independently in the re‐audit. The scores from primary and re‐audit were compared to assess the impact of feedback from the primary audit.ResultsEight sonographers participated in the study. The median Audit Score increased significantly (P < 0.01), from 10.8 (range, 9.8–12.4) in the primary audit to 12.4 (range, 10.4–13.6) in the re‐audit. Scores allocated by the two reviewers in the re‐audit were not significantly different (P = 0.08).ConclusionObjective scoring of fetal heart images is feasible and has a positive impact on the quality of cardiac images acquired at the time of the routine anomaly scan. This audit tool has the potential to be applied in every obstetric scanning unit and may improve the effectiveness of screening for congenital heart defects. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Lifetime maximization schemes under end‐to‐end frame‐error constraints in wireless multimedia sensor networks
Authors: Lu Yi‐Jen , Sheu Tsang‐Ling 
Published: April 2009

AbstractOf significance in wireless multimedia sensor networks (WMSN) is the maintenance of media quality and the extension of route lifetime since media stream is more sensitive in quality requirement than data flow. In this paper, the problem of how to balance the needs on constraining end‐to‐end (e2e) quality and prolonging lifetime in an established route can be interpreted as a nonlinear optimization paradigm, which is then shown to be a max—min composite formulation when an e2e frame‐error probability is given. To solve this max—min problem, we propose two novel methods: route‐associated power management (RAPM) and link‐associated power management (LAPM). For computation‐restricted sensor nodes, the RAPM scheme with adding a simplification condition on power management can effectively reduce the power cost at computation and also rapidly determine optimum lifetime from numerous candidate routes. On the other hand, if computing power is not the major concern in a sink node, rather than using a heuristic method, we employ the LAPM algorithm to solve the lifetime maximization problem in a more accurate fashion. Solid theoretical analysis and simulation results are presented to validate our proposed schemes. Both analytical and simulation results demonstrate that the LAPM scheme is very comparable to the heuristic approach. Copyright © 2009 John Wiley & Sons, Ltd.
Reactivity of 2,2′‐Bis(2N‐(1,1′,3,3′‐tetramethyl‐guanidino))diphenylene‐amine with CuI and [Cu(MeCN)4][PF6]: Benzimidazole Formation vs. Cu Oxidation
Authors: Herres‐Pawlis Sonja , Seshadri Tarimala , Flörke Ulrich , Henkel Gerald 
Published: April 2009

AbstractThe reaction of 2,2′‐Bis(2N‐(1,1′,3,3′‐tetramethyl‐guanidino))diphenylene‐amine (TMG2PA) (1) with CuI in MeCN results in the formation of [CuII(TMG2PAamid)I] (2) indicatingthat CuI is the target of an oxidative attack of the N‐H proton of the ligand which itself is converted to molecular hydrogen. In contrast, if [Cu(MeCN)4][PF6] is used as the CuI source, [CuI2(TMGbenz)2][PF6]2 (3) is obtained instead. The use of the non‐coordinating counterion [PF6]– apparently prevents CuI from oxidation but induces itself a cyclisation reaction within the ligand which results in the formation of a benzimidazole‐guanidine ligand.
Sodium Nitroprusside as a Source of Metalloligand in Direct Synthesis of Cu/Fe Complexes
Authors: Vreshch Olesia V. , Nesterova Oksana V. , Kokozay Vladimir N. , Dyakonenko Viktoriya V. , Shishkin Oleg V. , Cormary Benoit , Malfant Isabelle , Jezierska Julia 
Published: April 2009

AbstractThis article discusses synthesis of two heterometallic complexes [Cu(phen)2Fe(CN)5(NO)]·2H2O (1) and [Cu(phen)3][Fe(CN)5(NO)]·2H2O (2) prepared from zerovalent copper, sodium nitroprusside (SNP), ammonium thiocyanate in dimethylformamide (DMF) solution of 1,10‐phenanthroline (phen). Single crystal X‐ray analysis revealed that compound 1 has a molecular structure with [Cu(phen)2]2+ and [Fe(CN)5NO]2– blocks joined through a bridging CN group of nitroprusside whereas compound 2 consists of a separate [Cu(phen)3]2+ cation and [Fe(CN)5NO]2– anion. The magnetic behaviour of compound 1 is paramagnetic. Compound 1 displays photo‐induced transition to the metastable state SI after irradiation with blue light, what was proved by a low‐frequency shift of ν(N–O) bands.
Facile Fabrication of Ultrafine Copper Nanoparticles in Organic Solvent
Authors: Zhang Han-Xuan , Siegert Uwe , Liu Ran , Cai Wen-Bin 
Published: April 2009

Abstract
A facile chemical reduction method has been developed to fabricate ultrafine copper nanoparticles whose sizes can be controlled down to ca. 1 nm by using poly(N-vinylpyrrolidone) (PVP) as the stabilizer and sodium borohyrdride as the reducing agent in an alkaline ethylene glycol (EG) solvent. Transmission electron microscopy (TEM) results and UV–vis absorption spectra demonstrated that the as-prepared particles were well monodispersed, mostly composed of pure metallic Cu nanocrystals and extremely stable over extended period of simply sealed storage.
Children's catastrophic thinking about their pain predicts pain and disability 6 months later
Authors: Vervoort T. , Eccleston C. , Goubert L. , Buysse A. , Crombez G. 
Published: April 2009

AbstractCatastrophic thinking about pain has been identified as an important determinant of adjustment to pain, in both adults and children. No study has investigated the prospective and unique role of catastrophizing in explaining later pain and disability in children. The aim of the present study was to investigate the prospective roles of catastrophic thinking about pain, pain intensity, and trait anxiety and their putative relationship with pain and disability tested 6 months later. Participants were 323 schoolchildren. Analyses revealed that the child's pain catastrophizing at baseline had a small but unique contribution to the prediction of pain and disability 6 months later, even when controlling for the initial pain and disability levels. In line with expectations, moderation analyses revealed that the effects of catastrophizing upon pain and disability at follow‐up were only true for those children reporting low levels intensity of pain at baseline. The variability in disability and pain complaint could not be explained by trait anxiety. Instead anxious disposition might be best conceived of as a precursor of catastrophizing in children; i.e. children with higher levels of trait anxiety at baseline were more inclined to report higher levels of catastrophizing at follow‐up. The findings are discussed in terms of potential mechanisms through which catastrophizing might exert its negative impact upon pain and disability outcomes in children.
Central pain in multiple sclerosis – Sensory abnormalities
Authors: Österberg A. , Boivie J. 
Published: April 2009

AbstractMany patients with multiple sclerosis (MS) develop central neuropathic pain (CP). In the present study somatosensory abnormalities have been analysed in detail in 62 patients with MS and CP (42 women, 20 men; mean age 52 years) and in a control group of 10 women and 6 men (mean age 47 years) with MS and sensory symptoms, but without pain.Assessment included clinical testing and quantitative methods (QST) for the measurement of perception thresholds for touch, vibration, and temperatures.All CP patients except two (97%) had abnormal thresholds for innoxious and/or noxious temperatures, compared to 81% in the control group (p < 0.05). There was a tendency towards the opposite regarding sensibility to touch, which was decreased in 66% vs. 87% (n.s.), vibration (55% vs. 81%; n.s.) and to joint movement (32% vs. 62%; p < 0.04).Comparisons between painful and non‐painful regions showed both the absolute threshold values and the index values to be significantly more abnormal, in the CP regions, for warmth (p < 0.001), cold (p < 0.05), difference limen (innoxious warmth and cold, p < 0.01), cold pain (p < 0.01) and heat pain/cold pain combined (p < 0.001).Also the comparisons between regions with central pain and regions with sensory symptoms in the controls showed significantly more abnormal thresholds in the CP patients for warmth (p < 0.05), cold (p < 0.01), difference limen (innoxious warmth and cold, p < 0.01) and heat pain/cold pain combined (p < 0.001).The results support the general hypothesis that only patients who have lesions affecting the spinothalamo‐cortical pathways run the risk of developing central pain.
Changes in levator ani muscle after vaginal hysterectomy and prolapse repair using the Total Prolift procedure
Authors: Song Yanfeng , Ye Peixiang , Hong Xinru , Ke Guizhu , Sun Qinghua , Chen Ziqian , Ma Ming 
Published: April 2009

AbstractObjectiveTo assess changes in the levator plate angle (LPA), anteroposterior length of the levator hiatus (H‐line), and pelvic floor descent (M‐line) after vaginal hysterectomy and prolapse repair using the Gynecare Prolift Total Pelvic Floor Repair System.MethodsBefore and after the intervention, 20 women with pelvic floor prolapse underwent dynamic magnetic resonance imaging in supine position during the Valsalva maneuver to measure the LPA, H‐line, and M‐line. Paired t tests were performed and Pearson correlation coefficients calculated from values obtained using the pelvic organ prolapse quantification system.ResultsAfter the intervention the LPA was smaller (46.92° vs 55.39°, P < 0.05), the H‐line was shorter (53.70 cm vs 60.46 cm, P < 0.05), and the M‐line was shorter (19.58 cm vs 25.27 cm, P < 0.05).ConclusionThese changes suggest an efficient reconstruction and reinforcement of the pelvic floor after the surgery.
The comparative absorption of silicon from different foods and food supplements
Authors: Sripanyakorn Supannee , Jugdaohsingh Ravin , Dissayabutr Wacharee , Anderson Simon H. C. , Thompson Richard P. H. , Powell Jonathan J. 
Published: April 2009

Dietary Si (orthosilicic acid; OSA) appears important in connective tissue health, and although the sources and intakes of Si are well established, its absorption is not. Si absorption was measured from eight high-Si-containing sources: alcohol-free beer; OSA solution (positive control); bananas; green beans; supplemental choline-stabilised OSA (ChOSA); supplemental monomethyl silanetriol (MMST); supplemental colloidal silica (CS); magnesium trisilicate British Pharmacopoeia antacid (MTBP). Two of the supplements and the antacid were pre-selected following an in vitro dissolution assay. Fasting, healthy subjects (CS, n 3; others, n ≥ 5) each ingested two of the sources separated by a 1-week wash-out period. Blood and urine were collected and measured for total Si concentrations by inductively coupled plasma optical emission spectrometry. Absorption, based on urinary Si excretion, was highest for MMST and alcohol-free beer (64 % of dose), followed by green beans (44 %), OSA (43 %), ChOSA (17 %), bananas and MTBP (4 %) and CS (1 %). Peak serum concentrations occurred by 0.5 h for MMST and green beans, 1.5 h for OSA and alcohol-free beer, 2 h for ChOSA and CS, and 4 h for MTBP. Area under the serum curves correlated positively with urinary Si output (r 0·82; P < 0·0001). Absorption of Si from supplements and antacids was consistent with their known chemical speciation and kinetics of dissolution under simulated gastrointestinal conditions. Monomeric silicates were readily absorbed, while particulate silicates were decreasingly well absorbed with increasing polymerisation. The present results highlight the need to allow for relative absorption of Si from different foods or supplements in subsequent epidemiological and intervention studies.
Sip size of orangeade: effects on intake and sensory-specific satiation
Authors: Weijzen Pascalle L. G. , Smeets Paul A. M. , de Graaf Cees 
Published: April 2009

Sensory-specific satiation (SSS) drives food selection and contributes to meal termination. We hypothesised that smaller sips would increase SSS due to increased oro-sensory exposure, irrespective of energy content. The objective was to determine the effects of sip size and energy content on ad libitum intake of orangeade and subjective SSS for orangeade. Orangeade intake and ratings of wanting and liking were measured before and after ad libitum orangeade consumption in a 2 × 2 cross-over design (n 53). Conditions differed in energy content (no-energy v. regular-energy orangeade) and in sip size (large, 20 g/sip v. small, 5 g/sip). The mean intake of both orangeades was lower when consumed with small sips than when consumed with large sips (regular-energy, 352 v. 493 g; no-energy, 338 v. 405 g; both P < 0·001). When consumed with large sips, the mean intake of no-energy orangeade was lower than that of regular-energy orangeade (P = 0·02). When consumed with small sips, subjective SSS (based on the desire to drink) was higher for no-energy orangeade than for regular-energy orangeade (P = 0·01), while mean intake was comparable. We concluded that smaller sip size, i.e. increased oro-sensory exposure per unit of consumption, can lower intake of sweet drinks. Only with low oro-sensory exposure (large sip size) was intake higher for an energy-containing sweet drink than for a no-energy sweet drink. This suggests that intake of sweet drinks is stimulated by (metabolic) reward value and inhibited by sensory satiation. This underpins the importance of SSS for meal termination.