bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation of hydrogen adsorption with increasing Li doping on carbon nanotubes
Authors: Rangel E. , Ramirez‐de‐Arellano J. M. , Magana L. F. 
Published: December 2010

AbstractDensity functional theory (DFT) and molecular dynamics (MD) were used to study hydrogen adsorption on the external surface of single‐walled carbon nanotubes decorated with Li. We considered doping ratios of C64Li, C8Li, and C4Li. We found that these systems could store up to 0.77, 3.7, and 7.6 wt.% hydrogen, respectively, at atmospheric pressure and 300 K. The latter case satisfies the requirement for technological applications. However, experimentally, carbon nanotubes are in bundles. Therefore, we studied a bundle of nanotubes each with coverage C4Li, under the same conditions. We found that the hydrogen storage capacity is drastically reduced to 2.7 wt.%. This figure is very similar to experimental results.
Size‐, dimensionality‐, and composition‐dependent Debye temperature of monometallic and bimetallic nanocrystals in the deep nanometer scale
Authors: Yang C. C. , Li S. 
Published: December 2010

AbstractA nanothermodynamic model was established to describe the Debye temperature of monometallic and bimetallic nanocrystals in the deep nanometer scale with respect to the effects of size, dimensionality, and also composition. The results indicate that the Debye temperature decreases with decreasing crystal size for both monometallic and bimetallic nanocrystals, which is consistent with the experimental data. With considering the physicochemical properties of monometallic and bimetallic nanocrystals in the sub‐5 nm scale, the developed model may provide new insight into the fundamental understanding of their thermal stability for applications in heterogeneous catalysis, sensors as well as microelectronic devices.
Perspective: Björn Roos and direct configuration interaction
Authors: Shavitt Isaiah 
Published: December 2010

AbstractThe introduction, impact, and development of the direct configuration interaction (CI) approach are reviewed. The removal of the limitation on the size of CI calculation by eliminating the need to store the Hamiltonian matrix and the streamlining of the calculation of the eigenvector updates in each iteration are seen to be the key transformative contributions of this approach. The initial introduction, limited to closed‐shell single‐reference CISD (CI with single and double excitations) calculations, underwent successive generalizations, culminating in procedures based on the graphical unitary group approach, allowing applications to multireference CISD calculations for any electronic state. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111:3263–3266, 2010
Unique para‐effect in electron ionization mass spectra of bis(perfluoroacyl) derivatives of bifunctional aminobenzenes
Authors: Tretyakov Kirill V. , Todua Nino G. , Borisov Roman S. , Zaikin Vladimir G. , Stein Stephen E. , Mikaia Anzor I. 
Published: December 2010

AbstractA new kind of ‘para‐effect’ under electron ionization (EI) conditions has been discovered for a series of bis(perfluoroacyl) derivatives of o‐, m‐ and p‐phenylenediamines, ‐hydroxybenzeneamines and ‐mercaptobenzeneamines of a common structure RCOX–C6H4–NHCOR (X = NH, S, O; R = CF3, C2F5, C3F7). Only the para‐isomers showed successive loss of a radical RCO• and a molecule RCN, leading to very intense peaks in the EI spectra. The composition and the origin of the [M–COR–NCR]+ ions were confirmed by exact mass measurements and linked scan experiments. The proposed mechanism of their formation takes into account likely para‐quinoid structures of the precursor ions. A similar rearrangement has not been observed for para‐isomers in the series of bis(perfluoroacyl) derivatives of benzenediols, mercaptophenols and dimercaptobenzenes. Published in 2010 by John Wiley & Sons, Ltd.
Ultrasound ionization of biomolecules
Authors: Wu Chen‐I , Wang Yi‐Sheng , Chen Nelson G. , Wu Chung‐Yi , Chen Chung‐Hsuan 
Published: December 2010

AbstractTo date, mass spectrometric analysis of biomolecules has been primarily performed with either matrix‐assisted laser desorption/ionization (MALDI) or electrospray ionization (ESI). In this work, ultrasound produced by a simple piezoelectric device is shown as an alternative method for soft ionization of biomolecules. Precursor ions of proteins, saccharides and fatty acids showed little fragmentation. Cavitation is considered as a primary mechanism for the ionization of biomolecules. Copyright © 2010 John Wiley & Sons, Ltd.
Direct analysis of trace level bisphenol A, octylphenols and nonylphenol in bottled water and leached from bottles by ultra‐high‐performance liquid chromatography/tandem mass spectrometry
Authors: Wang Jinyuan , Schnute William C. 
Published: December 2010

AbstractA high‐throughput method was developed for the direct analysis of trace level bisphenol A (BPA), 4‐n‐octylphenol (4‐n‐OP), 4‐tert‐octylphenol (4‐t‐OP) and 4‐n‐nonylphenol (4‐n‐NP) in water samples by ultra‐high‐performance liquid chromatography/tandem mass spectrometry (uHPLC/MS/MS) using an isotope‐labeled internal standard. Aliquots of water samples were spiked with the internal standard and analyzed without sample cleanup or enrichment. All target analytes were chromatographically separated within 3 min and detected using the highly selective multiple reaction monitoring (MRM) detection mode. The method detection limits were statistically calculated and ranged from 0.040 ppb (BPA) to 0.057 ppb (4‐n‐NP). Excellent correlation of determination was achieved for each analyte with r greater than 0.995. Precision was achieved within 8% relative standard deviation (RSD) for all analytes, and recoveries from spiked samples ranged from 97% to 106.2% except for 4‐n‐OP which may be corrected by using an isotope‐labeled analog as internal standard. This method was used for analyzing eight randomly selected bottled water samples and found no detectable target analytes. This method was also used to analyze target analytes leached from bottles (6 low cost bottles and 6 brand‐name baby‐feeding bottles). Low levels of BPA were found in three bottles after they had been heated in a microwave oven, and a trace amount of 4‐n‐NP was also found in three bottles. 4‐t‐OP, which has not been reported as a leachable chemical, was found in two brand name baby‐feeding bottles from the same manufacturer, and was confirmed with bottles from different batches. Copyright © 2010 John Wiley & Sons, Ltd.
Measurement of the δ34S value in methionine by double spike multi‐collector thermal ionization mass spectrometry using Carius tube digestion
Authors: Mann Jacqueline L. , Kelly W. Robert 
Published: December 2010

AbstractMethionine is an essential amino acid and is the primary source of sulfur for humans. Using the double spike (33S‐36S) multi‐collector thermal ionization mass spectrometry (MC‐TIMS) technique, three sample bottles of a methionine material obtained from the Institute for Reference Materials and Measurements have been measured for δ34S and sulfur concentration. The mean δ34S value, relative to Vienna Canyon Diablo Troilite (VCDT), determined was 10.34 ± 0.11‰ (n = 9) with the uncertainty reported as expanded uncertainties (U). These δ34S measurements include a correction for blank which has been previously ignored in studies of sulfur isotopic composition. The sulfur concentrations for the three bottles range from 56 to 88 µg/g. The isotope composition and concentration results demonstrate the high accuracy and precision of the DS‐MC‐TIMS technique for measuring sulfur in methionine. Published in 2010 by John Wiley & Sons, Ltd.
Rapid screening and characterization of metabolites from a marine‐derived actinomycete by high‐performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry
Authors: Liu Cheng‐Wei , Lu Yuan‐Yuan , Yang Zhen‐Zheng , Xing Ying‐Ying , Xi Tao 
Published: December 2010

AbstractA rapid and reliable method has been optimized and established for the analysis of the metabolites from a marine actinomycete by high‐performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry (HPLC/QTOF MS/MS). From MS/MS spectra, the product ions of [M + H]+ were recorded to provide abundant structural information of the mother nucleus and peptide moieties. Using the QTOF MS/MS and in‐source collision‐induced dissociation (in‐source CID) techniques, three main metabolites including actinomycin D, actinomycin V and actinomycin I were determined and characterized by elemental compositions of precursor and product ions (<7 ppm). Additionally, this method provided information about the compositions of the peptide residues and the sequences of the amino acid from a series of fragment ions. It proved useful for the identiﬁcation of the metabolites in marine samples which have similar structures especially when there were no reference compounds available. Copyright © 2010 John Wiley & Sons, Ltd.
Rapid characterization of triterpene saponins from Conyza blinii by liquid chromatography coupled with mass spectrometry
Authors: Qiao Xue , Zhang Xing , Ye Min , Su Yan‐fang , Dong Jing , Han Jian , Yin Jun , Guo De‐an 
Published: December 2010

AbstractConyza blinii Le'vl is a medicinal herb used for the treatment of inflammation in Chinese folk medicine. Its major bioactive constituents are triterpene saponins, most of which contain 6–8 sugar residues. In this report, electrospray ionization tandem mass spectrometry fragmentation behaviors of bisdesmosidic triterpene saponins (conyzasaponin A, B, and C) were studied in both positive and negative ion modes with an ion‐trap mass spectrometer. In full scan mass spectrometry, these saponins gave predominant [M–H]− and [M+Na]+ ions, which determined the molecular weights. In tandem mass spectrometry (MSn, n = 2–4), the [M–H]− and [M+Na]+ ions yielded fragments [Y0α–H]− and [Bα+Na]+, which were diagnostic for the structures of the triterpene skeleton and sugar chains. The structural elucidation was approved by accurate mass data using IT‐TOF‐MS. An interpretation guideline based on MSn (n = 2–4) diagnostic ions was proposed in order to elucidate the chemical structures of unknown triterpene saponins in C. blinii extract. The saponins in C. blinii were separated by liquid chromatography with a methanol/acetonitrile/water solvent system, and then analyzed by ion‐trap and IT‐TOF mass spectrometers. Based on the interpretation guideline, a total of 35 triterpenoid saponins were tentatively identified. Among them, 15 saponins had been previously reported, and the other 20 saponins were reported from Conyza species for the first time. This study indicates that LC/MS is a powerful technology for the rapid characterization of complicated saponins in herbal extracts. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of the volatile organic compounds of Italian ‘Fossa’ cheese by solid‐phase microextraction gas chromatography/mass spectrometry
Authors: Gioacchini Anna Maria , De Santi Mauro , Guescini Michele , Brandi Giorgio , Stocchi Vilberto 
Published: December 2010

AbstractFossa cheese is an Italian hard cheese, ripened for up to 3 months in underground pits dug into tuffaceous rock. During this period, the cheese develops a unique flavour and intense and somewhat piquant aroma. Solid‐phase microextraction gas chromatography/mass spectrometry (SPME‐GC/MS) was utilized to characterize the volatile organic compounds (VOCs) of Fossa cheese. A total of 75 VOCs were separated and identified; in particular, the major class of compounds found in the cheeses ripened in the pits were the esters of fatty acids. Discriminant analysis of volatile profiles allowed us to distinguish between cheeses in different stages of seasoning (60‐day‐old cheese and cheese ripened an additional 90 days in and out of the pits). Copyright © 2010 John Wiley & Sons, Ltd.
Seabird satellite tracking validates the use of latitudinal isoscapes to depict predators' foraging areas in the Southern Ocean
Authors: Jaeger Audrey , Lecomte Vincent J. , Weimerskirch Henri , Richard Pierre , Cherel Yves 
Published: December 2010

AbstractStable isotopes are increasingly being used to trace wildlife movements. A fundamental prerequisite of animal isotopic tracking is a good knowledge of spatial isotopic variations in the environment. Few accessible reference maps of the isotopic landscape (“isoscapes”) are available for marine predators. Here, we validate for the first time an isotopic gradient for higher trophic levels by using a unique combination of a large number of satellite‐tracks and subsequent blood plasma isotopic signatures from a wide‐ranging oceanic predator. The plasma δ13C and δ15N values of wandering albatrosses (n = 45) were highly and positively correlated to the Southern Ocean latitudes at which the satellite‐tracked individuals foraged. The well‐defined latitudinal baseline carbon isoscapes in the Southern Ocean is thus reflected in the tissue of consumers, but with a positive shift due to the cumulative effect of a slight 13C‐enrichment at each trophic level. The data allowed us to estimate the carbon isotopic position of the main oceanic fronts in the area, and thus to delineate robust isoscapes of the main foraging zones for top predators. The plasma δ13C and δ15N values were positively and linearly correlated, thus suggesting that latitudinal isoscapes also occur for δ15N at the base of the food web in oceanic waters of the Southern Ocean. The combination of device deployments with sampling of relevant tissues for isotopic analysis appears to be a powerful tool for investigating consumers' isoscapes at various spatio‐temporal scales. Copyright © 2010 John Wiley & Sons, Ltd.
Multiple‐stage mass spectrometry analysis of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and their derivatives
Authors: Gallart‐Ayala H. , Moyano E. , Galceran M.T. 
Published: December 2010

AbstractThe fragmentation of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives was studied by electrospray ioization tandem mass spectrometry. Multiple‐stage mass spectrometry and accurate mass measurements were combined to establish the fragmentation pathways. BADGEs and BFDGEs tend to form ammonium adducts under electrospray conditions which fragmented easily. The fragmentation of [M+NH4]+ for BADGEs started with the cleavage of the phenyl‐alkyl bond, which was followed by the α‐cleavage of the ether group to generate the characteristic product ions at m/z 135, [C9H11O]+, and m/z 107, [C7H7O]+. The fragmentation of the BFDGE isomer mixtures was studied by on‐line reversed‐phase liquid chromatography coupled to multiple‐stage mass spectrometry (LC/MSn). Information obtained from product ion spectra for each BFDGE isomer and its comparison with the fragmentation pathway of BADGE allowed each isomer and the chromatographic elution order to be identified. Copyright © 2010 John Wiley & Sons, Ltd.
Expansion of time window for mass spectrometric measurement of amide hydrogen/deuterium exchange reactions
Authors: Coales Stephen J. , E Sook Yen , Lee Jessica E. , Ma Anita , Morrow Jeffrey A. , Hamuro Yoshitomo 
Published: December 2010

AbstractBackbone amide hydrogen exchange rates can be used to describe the dynamic properties of a protein. Amide hydrogen exchange rates in a native protein may vary from milliseconds (ms) to several years. Ideally, the rates of all amide hydrogens of the analyte protein can be determined individually. To achieve this goal, monitoring of a wider time window is critical, in addition to high sequence coverage and high sequence resolution. Significant improvements have been made to hydrogen/deuterium exchange mass spectrometry methods in the past decade for better sequence coverage and higher sequence resolution. On the other hand, little effort has been made to expand the experimental time window to accurately determine exchange rates of amide hydrogens. Many fast exchanging amide hydrogens are completely exchanged before completion of a typical short exchange time point (10–30 s) and many slow exchanging amide hydrogens do not start exchanging before a typical long exchanging time point (1–3 h). Here various experimental conditions, as well as a quenched‐flow apparatus, are utilized to monitor cytochrome c amide hydrogen exchange behaviors over more than eight orders of magnitude (0.0044–1 000 000 s), when converted into the standard exchange condition (pH 7 and 23°C). Copyright © 2010 John Wiley & Sons, Ltd.
The impact of salt, fat and sugar levels on toddler food intake
Authors: Bouhlal Sofia , Issanchou Sylvie , Nicklaus Sophie 
Published: December 2010

Understanding the early determinants of food intake, in particular the role of food sensory quality, is a necessary step to improve the prevention of unhealthy food habits. However, the extent to which food intake varies according to salt, fat and sugar content is imperfectly known. The present study aimed at evaluating whether toddler food intake varied during lunches or snacks in which salt, fat or sugar contents had been modified in common foods. Seventy-four children (30 (se 0·5) months old) participated in the study in their usual day-care centres. Every other week, they were served lunches composed, among other items, of green beans and pasta with varying salt (0, 0·6 and 1·2 % added salt) or fat (0, 2·5 and 5 % added butter) levels and afternoon snacks composed of fruit purée varying in sugar level (0, 5 and 10 % added sugar). During each meal, children could eat as much as they wanted from the target foods. Each food was weighed before and after the meal. Salt level had a positive impact on the intake of the target foods. On the contrary, no impact of added fat or added sugar levels was observed. This implies that fat and sugar addition could be avoided in foods for children without having an impact on palatability, allowing the energy density of children's diet to be limited. Salt addition should be limited, but its suppression in vegetables, whose intake is to be promoted, should be considered cautiously.
Personality and bipolar disorder: dissecting state and trait associations between mood and personality
Authors: Barnett J. H. , Huang J. , Perlis R. H. , Young M. M. , Rosenbaum J. F. , Nierenberg A. A. , Sachs G. , Nimgaonkar V. L. , Miklowitz D. J. , Smoller J. W. 
Published: December 2010

BackgroundSome personality characteristics have previously been associated with an increased risk for psychiatric disorder. Longitudinal studies are required in order to tease apart temporary (state) and enduring (trait) differences in personality among individuals with bipolar disorder (BD). This study aimed to determine whether there is a characteristic personality profile in BD, and whether associations between BD and personality are best explained by state or trait effects.MethodA total of 2247 participants in the Systematic Treatment Enhancement Program for Bipolar Disorder study completed the NEO Five-Factor Inventory administered at study entry, and at 1 and 2 years.ResultsPersonality in BD was characterized by high neuroticism (N) and openness (O), and low agreeableness (A), conscientiousness (C) and extraversion (E). This profile was replicated in two independent samples, and openness was found to distinguish BD from major depressive disorder. Latent growth modeling demonstrated that manic symptoms were associated with increased E and decreased A, and depressed symptoms with higher N and lower E, A, C and O. During euthymic phases, high N and low E scores predicted a future depression-prone course.ConclusionsWhile there are clear state effects of mood on self-reported personality, personality variables during euthymia predict future course of illness. Personality disturbances in extraversion, neuroticism and openness may be enduring characteristics of patients with BD.
Bridging Divides and Breaking Homes: Young Women's Lifecycle Labour Mobility as a Family Managerial Strategy
Authors: May Shannon 
Published: December 2010

AbstractThis article highlights the case of a rural north-east Chinese village where youth labour mobility is a marriage strategy deployed by parents and engaged in by young people given constraints on education and income in the countryside. While some rural mothers and their daughters do make the fairytale of “marrying-up” into an urban household come true, for most rural young women migrants the self-oriented consumption that they are encouraged to pursue free of rural domestic responsibilities sets them up for heartbreak when they are brought back for a rural marriage. As long as rural households are left to rely on the “insurance” of land and a younger generation to work it and provide labour of domestic subsistence, they will pull sons (and wives for them) back to the countryside, and try to marry daughters to urban households to expand their network of security. This new twist on an old managerial strategy sets up a tragic conflict: young men are encouraged to return to the countryside, while young women are pushed to provide a “uniting bridge” into the city and, when they fail, are brought back to the countryside for marriage. If the experiences of families in Huangbaiyu village are not an anomaly but signal a broader trend, a generation of returnee young women who are frustrated and angry in rural marriages and abandon their husbands and parents-in-law will dramatically influence the future of China's development.
Adaptation des aînés à la résidence pour personnes âgées: Activité de loisirs et autodétermination
Authors: Altintas Emin , Majchrzak Gaëlle , Leconte Claire , Guerrien Alain 
Published: December 2010

ABSTRACTThe purpose of this study was to better understand adjustment and life satisfaction in later life. In particular, it examined the contribution of leisure participation and motivation toward leisure in older people’s adjustment to their nursing homes and their satisfaction with life.. Study results underlined the contribution of participation in leisure activities both to the adaptation of an elderly person to his residence and to life satisfaction. In terms of adaptation to the residence, participation in recreational activities exhibited this mediational sequence: leisure participation → self-determined motivation for leisure → adjustment to nursing homes. This suggests that leisure participation has an indirect effect on older people’s adaptability. Various practical implications of this research emerge for the development of future recreational programs in nursing homes to promote seniors’ adaptation.
Influenza surveillance in Shenzhen, the largest migratory metropolitan city of China, 2006–2009
Authors: WANG X. , CHENG X. W. , MA H. W. , HE J. F. , XIE X. , FANG S. S. , WU C. L. , LU X. , MEI S. J. , LI Y. , CHENG J. Q. 
Published: December 2010

SUMMARYShenzhen is one of the largest migratory metropolitan cities in China. A standardized influenza surveillance system has been operating in Shenzhen for several years. The objectives of the present study were to describe the epidemiology of influenza in Shenzhen and to assess the impact of pandemic H1N1 on influenza activity. An average rate of 71 cases of influenza-like illness (ILI)/1000 consultations was reported, which was greater than the rate in the preceding 3 years. Laboratory surveillance showed that the annual proportion of specimens positive for influenza was 25·4% in 2009, representing a significant increase over the proportions of 5·4%, 11·6% and 12·2% in 2006, 2007 and 2008, respectively. A total of 414 ILI outbreaks were reported in 2009, which was a marked increase compared to the previous 3 years. Influenza activity reached a record high in Shenzhen in 2009. Seasonal A/H3N2 was the dominant strain during the summer and was gradually replaced by pandemic H1N1. A semi-annual cycle for influenza circulation began to appear due to the emergence of pandemic H1N1.