bluuebunny/crossref_metadata_2025_split huggingface dataset:
Negative Temperature Coefficient of Resistivity in Lightweight Conductive Carbon Nanotube/Polymer Composites
Authors: Xiang Zhi‐Dong , Chen Tao , Li Zhong‐Ming , Bian Xiang‐Cheng 
Published: January 2009

AbstractIt is particularly difficult to prepare a foam CPC material because its porous structure makes it hard to form a conductive network. We utilized acetone‐assisted dispersion to disperse CNTs into PU foam and successfully prepared a lightweight conductive CNT/assembled PU foam composite. The NTC effect, which exclusively exists in the melt state CPC materials, has unexpectedly been observed in the solid‐state lightweight conductive CNT/sPU composite. Higher gas fraction and lower matrix modulus could result in stronger NTC effect. The mechanism that thermal expansion of gas wrapped in the cellular structure induces more perfect conductive paths has been proposed to satisfactorily elucidate the NTC effect and its gas fraction and matrix modulus dependence.magnified image
Nuclear import of human MLH1, PMS2, and MutLα: Redundancy is the key
Authors: Leong Vivian , Lorenowicz Jessica , Kozij Natalie , Guarné Alba 
Published: January 2009

AbstractDNA mismatch repair maintains genomic stability by correcting errors that have escaped polymerase proofreading. Defects on mismatch repair genes lead to an increased mutation rate, microsatellite instability and predisposition to human non‐polyposis colorectal cancer (HNPCC). Human MutLα is a heterodimer formed by the interaction of MLH1 and PMS2 that coordinates a series of key events in mismatch repair. It has been proposed that nuclear import of MutLα may be the first regulatory step on the activation of the mismatch repair pathway. Using confocal microscopy and mismatch repair deficient cells, we have identified the sequence determinants that drive nuclear import of human MLH1, PMS2, and MutLα. Transient transfection of the individual proteins reveals that MLH1 has a bipartite and PMS2 has a single monopartite nuclear localization signal. Although dimerization is not required for nuclear localization, the MutLα heterodimer is imported more efficiently than the MLH1 or PMS2 monomers. Interestingly, the bipartite localization signal of MLH1 can direct import of MutLα even when PMS2 encompasses a mutated localization signal. Hence we conclude that the presence of redundant nuclear localization signals guarantees nuclear transport of MutLα and, consequently, efficient mismatch repair. © 2009 Wiley‐Liss, Inc.
Considerations of the discontinuous deformation analysis on wave propagation problems
Authors: Gu Jiong , Zhao Zhiye 
Published: January 2009

AbstractIn rock engineering, the damage criteria of the rock mass under dynamic loads are generally governed by the threshold values of wave amplitudes, such as the peak particle velocity and the peak particle acceleration. Therefore, the prediction of wave attenuation across fractured rock mass is important on assessing the stability and damage of rock mass under dynamic loads. This paper aims to investigate the applications of the discontinuous deformation analysis (DDA) for modeling wave propagation problems in rock mass. Parametric studies are carried out to obtain an insight into the influencing factors on the accuracy of wave propagations, in terms of the block size, the boundary condition and the incident wave frequency. The reflected and transmitted waves from the interface between two materials are also numerically simulated. To study the tensile failure induced by the reflected wave, the spalling phenomena are modeled under various loading frequencies. The numerical results show that the DDA is capable of modeling the wave propagation in jointed rock mass with a good accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
Antidepressant medication use and risk of persistent pulmonary hypertension of the newborn
Authors: Andrade Susan E. , McPhillips Heather , Loren David , Raebel Marsha A. , Lane Kimberly , Livingston James , Boudreau Denise M. , Smith David H. , Davis Robert L. , Willy Mary E. , Platt Richard 
Published: January 2009

AbstractPurposeTo determine the prevalence of persistent pulmonary hypertension of the newborn (PPHN) among infants whose mothers were exposed to antidepressants in the third trimester of pregnancy compared to the prevalence among infants whose mothers were not exposed to antidepressants in the third trimester.MethodsA retrospective study was conducted using the automated databases of four health plans participating in the HMO Research Network Center for Education and Research on Therapeutics. Women who delivered an infant in a hospital from 1 January 1996 through 31 December 2000 were identified. The administrative databases were used to identify full‐term infants whose mothers received an antidepressant during the third trimester of pregnancy and unexposed infants whose mothers did not receive an antidepressant during the third trimester. Hospitalization data were used to identify diagnoses or procedure codes potentially indicative of PPHN.ResultsAmong 1104 infants exposed to antidepressants in the third trimester and a matched sample of 1104 unexposed infants, five infants were classified by the expert reviewers as having PPHN. Among those infants whose mothers were exposed to selective serotonin reuptake inhibitors (SSRIs) in the third trimester, the prevalence of PPHN was 2.14 per 1000 (95% confidence interval (CI) 0.26, 7.74), while the prevalence among infants whose mothers were not exposed was 2.72 per 1000 (95%CI 0.56, 7.93).ConclusionsWe did not find an association between SSRI use in late pregnancy and PPHN. Limitations of the present study, including the small number of confirmed cases, suggest further research in this area may be warranted. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and X‐ray structures of unexpected 2‐O‐(5‐deoxy‐1,2‐O‐isopropylidene‐α‐D‐glucofuranos‐5‐yloxy)quinoxalines
Authors: Jarmoumi Chakir , Lakhrissi Brahim , Mondieig Denise , Négrier Philippe , Léger J. M. , Massip S. , Lazar Zhor , Benali Bouziane , Massoui Mohamed , Essassi El Mokhtar 
Published: January 2009

AbstractReaction of 3‐methyl‐2(1H)‐quinoxalinone (4) and 2(1H)‐quinoxalinone (5) with 5,6‐anhydro‐1,2‐O‐isopropylidene‐
α‐D‐glucofuranose 6 gives the unexpected O‐glucoquinoxalines derivatives by the intermediary novel intramolecular rearrangement of 5,6‐anhydro‐1,2‐O‐isopropylidene‐α‐D‐glucofuranose to the corresponding 3,6‐anhydro form. The obtained O‐glucoquinoxalines 7,8 were identified by NMR spectroscopy. The X‐ray crystal structures have been determined at room temperature. Moreover, a solid–solid phase transition has been detected at 198.9 K for O‐glucoquinoxalines 7 and the structure of the low‐temperature phase has been solved at 188 K. Copyright © 2009 John Wiley & Sons, Ltd.
The benzilic ester rearrangement: synthesis of labelled compounds and theoretical studies
Authors: Marques Carolina S. , Ramalho J. P. Prates , Burke Anthony J. 
Published: January 2009

Abstract1,3‐Diphenyl‐2(13C)‐hydroxy‐3‐methoxypropan‐1‐one was synthesised and used to probe the mechanism of a benzilic ester rearrangement (BER). Computational studies suggest that the preferred site of attack of the nucleophile in this benzilic ester rearrangement is on C‐14. On the basis of these results a new reaction mechanism is proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Enthalpies of formation and isomerization of cis‐ and trans‐decalin, and their oxa‐analogs by G3(MP2)//B3LYP calculations
Authors: Taskinen Esko 
Published: January 2009

AbstractG3(MP2)//B3LYP calculations have been carried out on trans‐ and cis‐decalin, and their mono‐, di‐, tri‐, and tetraoxa‐analogs. The main purpose of the work was to obtain enthalpies of formation for these compounds, and to study the relative stabilities of the cis–trans and positional isomers of the various (poly)oxadecalins. Comparison of the computational enthalpies of formation with the respective experimental ones, known only for the decalins and 1,3,5,7‐tetraoxadecalins, shows that in both cases the computational values are more negative than the experimental ones, the deviations being −5 to −7 kJ mol−1 for the decalins and −12 to −17 kJ mol−1 for the 1,3,5,7‐tetraoxadecalins. The respective computational enthalpies of cis–trans isomerization, however, are in excellent to satisfactory agreement with the experimental data. The cis–trans enthalpy differences vary from +11.0 kJ mol−1 for decalin to −15.4 kJ mol−1 for 1,4,5,8‐tetraoxadecalin. Low relative enthalpy values were also calculated for the cis isomers of 1,8‐dioxadecalin (−3.7 kJ mol−1), 1,3,6‐trioxadecalin (−4.6 kJ mol−1), 1,3,8‐trioxadecalin (−9.7 kJ mol−1), 1,4,5‐ trioxadecalin (−5.6 kJ mol−1), 1,3,5,8‐tetraoxadecalin (−7.3 kJ mol−1), and 1,3,6,8‐tetraoxadecalin (−14.5 kJ mol−1). Copyright © 2009 John Wiley & Sons, Ltd.
Hydrogen cyanide as a biomarker for Pseudomonas aeruginosa in the breath of children with cystic fibrosis
Authors: Enderby Beth , Smith David , Carroll W. , Lenney W. 
Published: January 2009

AbstractHypothesis:Hydrogen cyanide (HCN) is emitted by Pseudomonas aeruginosa (PA) in vitro. We hypothesized that exhaled HCN could be measured using Selected Ion Flow Tube Mass Spectrometry (SIFT‐MS) and that concentrations would be higher in children with cystic fibrosis (CF) and PA infection than in children with asthma.Methods:Children aged 7–17 years with CF (n = 16) or asthma (n = 21) attending outpatient clinics provided breath samples between July and December 2007. HCN was measured using the SIFT‐MS Profile 3 instrument. FeNO was measured with a Sievers NOA 280i analyzer. Baseline inter‐group differences between HCN and FeNO concentrations were compared using the Mann–Whitney U test. Children were invited to re‐attend fortnightly. Breath samples, spirometry, growth and clinical status were measured at each visit.Results:There were significant baseline differences in exhaled HCN and FeNO concentrations between the two groups. Children with CF had higher median HCN concentrations than those with asthma: 13.5 parts per billion (ppb) (IQR 8.1–16.5) versus 2.0 ppb (IQR 0.0–4.8) (P < 0.001). Children with CF had lower median FeNO levels compared to children with asthma: 13.4 ppb (IQR 8.9–17.6) versus 57.9 ppb (IQR 34.0–85.7) (P < 0.001). Intra‐subject variability was high and significant changes in HCN concentrations were not observed related to changes in lung function or clinical status.Conclusion:This study provides proof of principle that HCN is detectable in the breath of children with CF and is elevated compared to children with asthma. Further studies are required to capture data from acutely unwell children and more accurately delineate responses to treatment. Pediatr Pulmonol. 2009; 44:142–147. © 2009 Wiley‐Liss, Inc.
Respiratory function during infancy in survivors of the INNOVO trial
Authors: Hoo Ah‐Fong , Beardsmore Caroline S. , Castle Rosemary A. , Ranganathan Sarath C. , Tomlin Keith , Field David , Elbourne Diana , Stocks Janet 
Published: January 2009

AbstractRationale:Despite encouraging reports suggesting that inhaled nitric oxide (iNO) appear to improve outcome in hypoxemic term and near term infants by improving oxygenation and reducing need for ECMO, the long‐term benefits of iNO remain unclear. This study aimed to compare lung function at approximately 1 year in infants who were and were not randomly allocated to iNO as part of their neonatal management for severe respiratory failure at birth. Furthermore, results were compared to lung function of healthy infants.Methods:Maximal expiratory flow at functional residual capacity $(V'_{{\rm maxFRC}} )$ was measured at approximately 1 year of age (corrected for any prematurity) in survivors of the INNOVO trial. Results were expressed as Z‐scores, adjusted for sex and body size, based on data from healthy controls using identical techniques.Results:Technically satisfactory results were obtained in 30 infants (53% < 34 weeks gestation), 19 of whom were randomized to receive iNO $V'_{{\rm maxFRC}}$. Z‐score was significantly reduced in infants with prior respiratory failure, whether or not they had been allocated to iNO (mean (SD) Z‐score: −2.0 (1.2) and −2.6 (1.1), respectively, 95% CI difference; iNO vs. no iNO: −0.3; 1.6, P = 0.2). There was significant respiratory morbidity in both groups during the first year of life.Conclusions:These results suggest that airway function remains reduced at 1 year of age following severe respiratory failure at birth, whether or not iNO is administered. Pediatr Pulmonol. 2009; 44:155–161. © 2009 Wiley‐Liss, Inc.
A Schottky top‐gated two‐dimensional electron system in a nuclear spin free Si/SiGe heterostructure
Authors: Sailer J. , Lang V. , Abstreiter G. , Tsuchiya G. , Itoh K. M. , Ager J. W. , Haller E. E. , Kupidura D. , Harbusch D. , Ludwig S. , Bougeard D. 
Published: January 2009

AbstractWe report on the realization and top‐gating of a two‐dimensional electron system in a nuclear spin free environment using 28Si and 70Ge source material in molecular beam epitaxy. Electron spin decoherence is expected to be minimized in nuclear spin‐free materials, making them promising hosts for solid‐state based quantum information processing devices. The two‐dimensional electron system exhibits a mobility of 18000 cm2/(V s) at a sheet carrier density of 4.6 × 1011 cm–2 at low temperatures. Feasibility of reliable gating is demonstrated by transport through split‐gate structures realized with palladium Schottky top‐gates which effectively control the two‐dimensional electron system underneath. Our work forms the basis for the realization of an electrostatically defined quantum dot in a nuclear spin free environment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lower uterine segment thickness measurement in pregnant women with previous Cesarean section: reliability analysis using two‐ and three‐dimensional transabdominal and transvaginal ultrasound
Authors: Martins W. P. , Barra D. A. , Gallarreta F. M. P. , Nastri C. O. , Filho F. M. 
Published: January 2009

AbstractObjectiveTo evaluate the reliability of two‐ and three‐dimensional ultrasonographic measurement of the thickness of the lower uterine segment (LUS) in pregnant women by transvaginal and transabdominal approaches.MethodsThis was a study of 30 pregnant women who had had at least one previous Cesarean section and were between 36 and 39 weeks' gestation, with singleton pregnancies in cephalic presentation. Sonographic examinations were performed by two observers using both 4–7‐MHz transabdominal and 5–8‐MHz transvaginal volumetric probes. LUS measurements were performed using two‐ and three‐dimensional ultrasound, evaluating the entire LUS thickness transabdominally and the LUS muscular thickness transvaginally. Each observer measured the LUS four times by each method. Reliability was analyzed by comparing the mean of the absolute differences, the intraclass correlation coefficients, the 95% limits of agreement and the proportion of differences < 1 mm.ResultsTransvaginal ultrasound provided greater reliability in LUS measurements than did transabdominal ultrasound. The use of three‐dimensional ultrasound improved significantly the reliability of the LUS muscular thickness measurement obtained transvaginally.ConclusionsUltrasonographic measurement of the LUS muscular thickness transvaginally appears more reliable than does that of the entire LUS thickness transabdominally. The use of three‐dimensional ultrasound should be considered to improve measurement reliability. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Doing worse but knowing better: An exploration of the relationship between HIV/AIDS knowledge and sexual behavior among adolescents in Flemish secondary schools
Authors: Berten Hans , Van Rossem Ronan 
Published: January 2009

ABSTRACTMost studies on sexual behavior have approached the relationship between AIDS knowledge and sexual behavior unidirectionally. This paper sets out to examine a reciprocal relationship between AIDS knowledge and sexual behavior, in which it is possible that adolescents who enter into sexuality may start to actively seek out information on sex. Additionally, the effects of various sources for AIDS‐related information and condom use are analyzed. Data from the Flemish Educational Assessment project, which surveyed a sample of adolescents from the 3rd and 5th years of secondary school, were used. Results indicate that the relationship between AIDS knowledge and sexual behavior is quite complex. On one hand, we find that better knowledge leads to a later onset of sexuality and more consistent condom use; on the other hand, we find that adolescents who start sex earlier and use condoms inconsistently tend to be more knowledgeable about AIDS.
Parameterization of EPIC crop model for simulation of cotton growth in South Texas
Authors: KO J. , PICCINNI G. , GUO W. , STEGLICH E. 
Published: January 2009

SUMMARYParameterization in crop simulation modelling is a general procedure to calibrate a crop model to explore the best fit for a certain regional environment of interest. The parameters of radiation use efficiency (RUE) and light interception coefficient (k) of cotton (Gossypium hirsutum) for different cultivars were estimated under various irrigation conditions in South Texas in 2006 and 2007. A calibration procedure was then performed for determination of RUE using the environmental policy impact calculator (EPIC) crop model (Williams et al.1984). This was carried out using data sets obtained separately from the data for parameter estimation. The estimates of k and RUE were 0·63 and 2·5 g/MJ, respectively, which were determined based on the field experiment and variation of simulated lint yield. When the parameters were used with EPIC to simulate the variability in lint yields, a correlation coefficient of 0·86 and root mean square error (RMSE) of 0·22 t/ha were obtained, presenting no significant differences (paired t-test: P=0·282) between simulation and measurement. The results demonstrate that an appropriate estimate of the model parameters including RUE is essential in order to make crop models reproduce field conditions properly in simulating crop growth, yield and other variables.
Study on strip spiral Blumlein line for the pulsed forming line of intense electron-beam accelerators
Authors: Liu J.L. , Cheng X.B. , Qian B.L. , Ge B. , Zhang J.D. , Wang X.X. 
Published: January 2009

AbstractThe pulse forming line (PFL) is the key part of the intense electron-beam accelerators (IEBA), which determines the quality and characteristic of the output beam current of the IEBA. Compared with the accelerator with traditional Blumlein line, an IEBA based on strip spiral Blumlein line (SSBL) can increase the duration of the output pulse in the same geometrical dimension. But the disadvantage of the SSBL is that the output voltage waveform at the matched load may be distorted, which influences the electron beam quality. In this paper, according to the electromagnetic theory, formulas for calculating the main electric parameters of SSBL (inductance, capacitance, transmission time, and characteristic impedance) are deduced. The effect of the geometric parameters of SSBL on the slowing coefficient is analyzed. The designed condition of SSBL for the output ideal voltage pulse in the matched load is obtained by theoretical analysis. Furthermore, the Karat code is used to simulate the output voltage waveform of SSBL on the matched load for different spiral angels. At last, a couple of contrastive experiments are performed on an electron-beam accelerator based on the SSBL with water dielectric. The experimental results agree with the theoretical and simulated results.
The Théâtre du Soleil, Part Two: the Road to Cambodia
Authors: Kiernander Adrian 
Published: January 2009

One theatre company alone in France, since the end of Vilar's Théâtre National Populaire, continues to make us consider the relationships between theatre and life, the place of theatre in society, its ability to modify the order of things in some way. It is the Théâtre du Soleil, guided by Ariane Mnouchkine.THE SEARCH for a contemporary popular theatre which has occupied the Théâtre du Soleil almost since its foundation 22 years ago has led the company at various times into innovations in both subject matter and performance style. Their latest production,The Terrible but Unfinished History of Norodom Sihanouk, King of Combodia, breaks new ground in both areas.
Trends in HCV prevalence, risk factors and distribution of viral genotypes in injecting drug users: findings from two cross-sectional studies
Authors: OLIVEIRA M. L. A. , YOSHIDA C. F. T. , TELLES P. R. , HACKER M. A. , OLIVEIRA S. A. N. , MIGUEL J. C. , do Ó K. M. R. , BASTOS F. I. 
Published: January 2009

SUMMARYIn the last decade, a declining prevalence of HCV infection has been described in injecting drug users (IDUs) in different countries. This study is the first to assess temporal trends in drug-injecting patterns, HCV infection rates and viral genotype distribution in 770 Brazilian IDUs, recruited by two cross-sectional studies (1994–1997 and 1999–2001). A substantial decline in the prevalence of HCV infection was found over the years (75% in 1994vs. 20·6% in 2001,P<0·001) that may be a consequence of the significant reduction in the overall frequencies of drug injection and needle-sharing, as well as the participation of IDUs in initiatives aimed at reducing drug-related harm. No trend was found in terms of viral genotype distribution. Despite the favourable scenario, preventive measures must be maintained, especially in vulnerable subgroups such as young or new injectors, where risky behaviours through direct and indirect sharing practices remain common.
Heightened stress responsiveness and emotional reactivity during pubertal maturation: Implications for psychopathology
Authors: Dahl Ronald E. , Gunnar Megan R. 
Published: January 2009

AbstractThe onset of adolescence, and more specifically the advent of pubertal maturation, represents a key developmental window for understanding the emergence of psychopathology in youth. The papers in this special section examine normative differences in the neurobiology of stress and emotional functioning over the peripubertal period. The work in this special section helps to fill in gaps in our understanding of key mechanisms that may contribute to increased vulnerabilities in behavioral and psychiatric morbidity during this developmental period.
Developmental changes in hypothalamus–pituitary–adrenal activity over the transition to adolescence: Normative changes and associations with puberty
Authors: Gunnar Megan R. , Wewerka Sandi , Frenn Kristin , Long Jeffrey D. , Griggs Christopher 
Published: January 2009

AbstractHome baseline and laboratory stressor (Trier Social Stress Test for Children) measures of salivary cortisol were obtained from 82 participants (40 girls) aged 9, 11, 13, and 15 years. Measures of pubertal development, self-reported stress, parent reports of child depressive symptoms and fearful temperament, and cardiac measures of sympathetic and parasympathetic activity were also obtained. Significant increases in the home cortisol baselines were found with age and pubertal development. Cortisol stress reactivity differed by age group with 11-year-olds and 13-year-old boys showing blunted reactivity and 9-year-olds, 13-year-old girls, and 15-year-olds showing significant cortisol reactions. Cortisol reactivity correlated marginally with sexual maturation. Measures of sympathetic activity revealed increased sympathetic modulation with age. Higher sympathetic tone was associated with more fearful temperament, whereas greater cortisol reactivity was associated with more anxious and depressed symptoms for girls. The importance of these findings for the hypothesis that puberty-associated increases in hypothalamic–pituitary–adrenal axis activity heightens the risk of psychopathology is discussed.