bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscoelastic behavior of polyacrylonitrile/dimethyl sulfoxide concentrated solution with water
Authors: Du Weiping , Chen Huifang , Xu Haifeng , Pan Ding , Pan Ning 
Published: June 2009

AbstractThe spinnability and polydispersity of polyacrylonitrile/dimethyl sulfoxide (PAN/DMSO)/H2O spinning solutions with conventional PAN molecular weight and comparative high PAN concentration have been investigated using a cone‐plate rheometer. It is observed from the measurements that, the viscosities of the solutions decreased with the rising of shear rate, and then stabilized to almost the same value, regardless of the PAN concentration. The chain orientation in the fiber formed under constant shear rate cannot be changed considerably even after long relaxation of more than 900s. For dynamic experiments, a steady increase of both G′ and G″ with escalating oscillation frequency was seen for all samples. Higher viscous‐elastic modulus at higher H2O content was found, too. It is also concluded from the log G′ − log G″ plot and the gel point that the PAN/DMSO/H2O system with regular PAN molecular weight behaves very close to a mono‐disperse system, thus very suitable for gel spinning and for preparation of high performance PAN precursor fiber. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1437–1442, 2009
Amphiphilic polymer electrolytes consisting of PVC‐g‐POEM comb‐like copolymer and LiCF3SO3
Authors: Koh Joo Hwan , Lee Kyung Ju , Seo Jin Ah , Kim Jong Hak 
Published: June 2009

AbstractAn amphiphilic comb‐like copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly((oxyethylene)9 methacrylate) (POEM) side chains, PVC‐graft‐POEM was synthesized via atom transfer radical polymerization. This comb copolymer was complexed with LiCF3SO3 to form a solid polymer electrolyte. FTIR and FT‐Raman spectroscopy indicate that lithium salts are dissolved in the ion conducting POEM domains of microphase‐separated graft copolymer up to 10 wt % of salt concentration. Microphase‐separated structure of the materials and the selective interaction of lithium ions with POEM domains were revealed by transmission electron microscopy, wide angle X‐ray scattering, and differential scanning calorimetry. The maximum ionic conductivity of 4.4 × 10−5 S/cm at room temperature was achieved at 10 wt % of salt concentration, above which salts are present as less mobile species such as ion pairs and higher order ionic aggregates, as characterized by FT‐Raman spectroscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1443–1451, 2009
Women's perceptions and experience of adjuvant tamoxifen therapy account for their adherence: breast cancer patients' point of view
Authors: Pellegrini Isabelle , Sarradon‐Eck Aline , Ben Soussan Patrick , Lacour Anne‐Claude , Largillier Rémy , Tallet Agnès , Tarpin Carole , Julian‐Reynier Claire 
Published: June 2009

AbstractObjective: The aim of this study on primary breast cancer patients undergoing adjuvant tamoxifen treatment was to determine how their perceptions of the treatment and their experience of side‐effects contributed to their adherence to the treatment.Methods: A consecutive series of primary breast cancer patients eligible for tamoxifen therapy were studied qualitatively by conducting semi‐structured in‐depth interviews at two French cancer centres.Results: The women aged 35–65 (N=34) were struggling with several issues involving their understanding and experience of the treatment, which have not been documented so far. These issues included confusion about the ‘hormonal’ nature and activity of tamoxifen and the etiology of the changes in their menopausal status, as well as the symbolic associations formed by patients about the paradox of taking a treatment that has aging effects but saves lives.Conclusions: This study shows the great physical burden often associated with tamoxifen treatment and brings to light women's own complex representations of the treatment and their interpretation of the side‐effects. Better communication between health‐care providers and patients should ultimately help to prevent refusal or discontinuation of tamoxifen treatment. Copyright © 2009 John Wiley & Sons, Ltd.
Impact of different chloride and glucose solutions on nasal potential difference
Authors: House Hugh H. , Middleton Peter G. 
Published: June 2009

AbstractIntroductionThe nasal potential difference (nasal PD) technique can provide useful diagnostic information and can be used to assess the physiological effect of new treatments for cystic fibrosis (CF). In preparation for multi center trials of new CF treatments, many groups worldwide have sought to standardize the protocol, but subtle differences in solution composition remain. This article has compared the effect of different chloride and glucose concentrations on the PD.MethodsFollowing pre‐treatment with amiloride to block sodium absorption, the effect of 0 mM versus 6 mM chloride was compared in six non‐CF and six CF subjects. In a separate series of experiments, the effect of glucose on baseline PD was examined in the range of 0–20 mM.ResultsFollowing amiloride pre‐treatment, the change from 6 to 0 mM chloride increased the PD by ∼2 mV in the non‐CF subjects; the reverse protocol decreased PD by a similar amount. As expected, little change in PD occurred in the CF subjects. Changing the glucose concentration between 0, 10, and 20 mM had little effect on nasal PD in non‐CF and CF subjects.ConclusionThe use of 0 mM chloride gives responses in the non‐CF subjects, which are ∼2 mV greater than protocols which use low (6 mM) chloride. Different glucose concentrations appear to exert little effect on baseline PD, suggesting that electrogenic glucose transport plays a limited role in airway transport at rest. Pediatr Pulmonol. 2009; 44:645–648. © 2009 Wiley‐Liss, Inc.
Spirometric pulmonary function parameters of healthy Chinese children aged 3–6 years in Taiwan
Authors: Jeng Mei‐Jy , Chang Hua‐Lun , Tsai Meng‐Chiao , Tsao Pen‐Chen , Yang Chia‐Feng , Lee Yu‐Sheng , Soong Wen‐Jue , Tang Ran‐Bin 
Published: June 2009

AbstractSpirometry is a well‐known technique for evaluating pulmonary function, but few studies have focused on preschool children. The aim of this study was to determine reference values of forced spirometric parameters in young Chinese children, aged 3–6 years, in Taiwan. Spirometric measurements were performed at day care centers by experienced pediatricians. Of 248 children without a history of chronic respiratory illness, at least two valid spirometric attempts were obtained from 214 children (109 boys and 105 girls; age: 36–83 [mean = 61] months; height: 90–131 [mean = 111] cm). Values of forced expiratory volume in 1 sec (FEV1) and 0.5 sec (FEV0.5), forced vital capacity (FVC), peak expiratory flow rate (PEF), forced expiratory between 25% and 75% FVC (FEF25–75), and forced expiratory flow rate at 25%, 50%, and 75% of FVC (FEF25, FEF50, and FEF75) were derived and analyzed. There were significant positive correlations between study parameters and body height, body weight, and age. Height was the most consistently correlated measurement in both boys and girls. Although boys tended to have higher spirometric values than girls, we found significant differences only in FVC and FEV1 between boys and girls aged 6 years. The regression equations of each parameter were obtained. In conclusion, spirometric pulmonary function tests are feasible in 3‐ to 6‐year‐old children. The obtained values and regression equations provide a reference for Chinese preschool children and may be of value in evaluating pulmonary function of children with respiratory problems in this age group. Pediatr Pulmonol. 2009; 44:676–682. © 2009 Wiley‐Liss, Inc.
Combined XBIC/μ‐XRF/μ‐XAS/DLTS investigation of chemical character and electrical properties of Cu and Ni precipitates in silicon
Authors: Trushin M. , Vyvenko O. , Seifert W. , Kittler M. , Zizak I. , Erko A. , Seibt M. , Rudolf C. 
Published: June 2009

AbstractCombination of DLTS method and synchrotron‐based analytical microprobe techniques was used to study the precipitation of Cu and Ni atoms at two kinds of structural defects in silicon lattice: dislocation network created by direct wafer bonding and oxygen‐induced microdefects. Results of our measurements revealed the difference in the preferred precipitation places: Ni particles in form of NiSi2 were found only at the dislocation network, while Cu particles in form of Cu3Si were found both at the dislocation network and at the oxygen‐induced microdefects. DLTS measurements showed Ni acceptor levels in Ni contaminated sample and a broad band related to Cu precipitates in Cu contaminated one. In case of simultaneous Cu and Ni contamination NiSi2 and Cu3Si precipitates were found definitely at the same places indicating therefore that the metals interact during precipitation. DLTS showed the superposition of spectra for only Ni and for only Cu contaminated samples. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generation and suppression of misfit dislocations at the seed/crystal interface in Si bulk crystal growth
Authors: Taishi Toshinori , Hoshikawa Keigo , Ohno Yutaka , Yonenaga Ichiro 
Published: June 2009

AbstractMechanism of generation and suppression of misfit dislocations in Si bulk crystal growth at the seed/crystal interface is studied. Misfit dislocations in B‐doped CZ‐Si crystal growth are suppressed when the difference in B concentration between a seed and the grown crystal is at least 9 × 1018 cm–3, corresponding to 4.5 × 10–5 of misfit strain. Similar misfit strain of 3.4 × 10–5 was obtained in Ge‐doped CZ‐Si crystal growth. In the CZ‐Si crystal growth, a transition region of impurity concentration with about 40 μm in width is formed at the seed/crystal interface in both dislocation‐free and dislocated crystals by diffusion of impurity atoms from the seed. From a macroscopic viewpoint at the seed/crystal interface, the critical misfit strain in Si bulk crystal growth is larger than that in epitaxial growth model in a consideration that the width of the transition region is the critical thickness of the grown layer. We propose a preliminary new mechanism of generation and suppression of misfit dislocations dependent on the local misfit strain at the interface during the growth from a microscopic viewpoint. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cation‐interlinking network cluster approach in application to extended defects in covalent‐bonded glassy semiconductors
Authors: Shpotyuk Oleh , Boyko Vitaliy , Hyla Malgorzata 
Published: June 2009

AbstractA principally new cation‐interlinking network cluster approach (CINCA) was proposed to describe different types of glass‐forming structural units in network covalent‐bonded solids like to chalcogenide vitreous semiconductors. Within this approach, two (or three) interconnected cation‐centered polyhedra form more stretched structural fragments conditionally named atomic clusters, reflecting in such a way whole backbone of covalent‐bonded semiconductor multiply duplicated in a space. The probability of possible atomic clusters is estimated with numerical parameter giving average formation energy in respect to the number of atoms involved in the cluster and average coordination number. This approach was probed at the example of regular network clusters based on AsS3/2 pyramids mutually‐interconnected through bridge ‐S‐ atom contrasted with irregular double‐bond‐based quasi‐tetrahedral structural S = AsS3 defects within binary As‐S system. The corresponding mathematical calculations confirming a preference of regularly‐linked structural units over irregular ones was performed using HyperChem 7.5 program. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of interstitials with buried amorphous layer in silicon
Authors: Oliviero E. , David M. L. , Fichtner P. F. P. 
Published: June 2009

AbstractBuried amorphous layers have been produced in silicon single crystal by lithium implantation at liquid nitrogen temperature and followed by a 400 °C annealing. By this process, a wide region, perfectly crystalline and free of any extended defect, is formed ahead of the buried amorphous layer up to the implanted surface. Neon has then been implanted in this front region at high fluence and high temperature (250 °C) in order to create bubbles and avoid further amorphization. In the presence of a buried amorphous layer, significant decrease of the extended defect density is observed at the neon end of range region. The results are discussed in terms of interstitial trapping, i.e. the buried amorphous layer acting as an efficient sink for interstitials during recrystallization. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Doping influence on the nanoindentation response of GaAs
Authors: Bourhis Eric Le , Patriarche Gilles 
Published: June 2009

AbstractWe have studied the nanoindentation structures realised at room temperature (RT) on (001) GaAs being either undoped, heavily n or p doped. Elastic‐plastic nanoindentations were made under a large range of loads (between 0.2 mN and 50 mN) at room temperature using a Berkovich indenter. Transmission electron microscopy (TEM) was used to observe systematically the nanoindentation structures (central zone and rosette arms) and to investigate changes in dislocations activity. The mechanical responses of all types of samples are relatively close either in terms of hardness or pop‐in load amplitude. In contrast, indentation rosette structure appears to be sensitive to doping. Perfect dislocations show long screw segments only in undoped and n‐doped specimens and this is attributed to mobility effects. Moreover, p‐doped specimens show no partial dislocations while undoped and n‐doped specimens show partial dislocations in one and both rosette arms respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamics of nanostructure formation using point defects on semiconductors by laser radiation
Authors: Medvid A. , Onufrijevs P. , Dauksta E. , Barloti J. , Grabovskis D. , Ulyashin A. 
Published: June 2009

AbstractDynamics of nanostructures (nanocones and nanocavties) formation on surface of semiconductors by laser radiation based on Thermogradient effect (TGE) is studied. Nanostructures formation of both nanohills and nanocavities are explained by point defects redistribution in gradient of temperature at the irradiated surface. Study of photoluminescence (PL), atomic force microscopy (AFM) and Raman back‐scattering spectra speak in favour of presence of quantum confinement effect (QCE) on the top of nanocones on the irradiated surface of semiconductor single crystals. Aggregation of vacancies under the irradiated surface forms nanocavities. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge‐derivatized amino acids facilitate model studies on protein side‐chain modifications by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Zhu Xiaochun , Anderson Vernon E. , Sayre Lawrence M. 
Published: June 2009

AbstractThe α‐amino groups of histidine and lysine were derivatized with p‐carboxylbenzyltriphenylphosphonium to form the pseudo dipeptides, PHis and PLys, which can be sensitively detected by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) due to the fixed positive charge of the phosphonium group. Detection limits of PHis and PLys by MALDI‐TOFMS were both 30 fmol with a signal‐to‐noise ratio of 5:1. These pseudo dipeptides were excellent surrogates for His‐ or Lys‐containing peptides in model reactions mimicking proteins with reactive electrophiles, prominently those generated by peroxidation of polyunsaturated fatty acids including 4‐hydroxy‐2(E)‐nonenal (HNE), 4‐oxo‐2(E)‐nonenal (ONE), 2(E)‐octenal, and 2(E)‐heptenal. An air‐saturated solution of linoleic acid (d0:d5 = 1:1) was incubated in the presence of Fe(II) and ascorbate with these two pseudo dipeptides, and the reaction products were characterized by MALDI‐TOFMS and liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS). By using PHis and PLys, the previously reported ONE‐derived His‐furan adduct was detected along with evidence for a cyclic α,β‐unsaturated ketone. A dimer formed from ONE was found to react with PHis through Michael addition. Alkenals were found to form two novel adducts with PLys. 2(E)‐Octenoic acid–His Michael adduct and Nε‐pentanoyllysine were identified as potential protein side‐chain adducts modified by products of linoleic acid peroxidation. In addition, when PHis or PLys and AcHis or BocLys were exposed to the linoleic acid peroxidation, an epoxy‐keto‐ocatadecenoic acid mediated His–His cross‐link was detected, along with the observation of a His–ONE/9,12‐dioxo‐10‐dodecenoic acid–Lys derived pyrrole cross‐link. Copyright © 2009 John Wiley & Sons, Ltd.
Phospholipids in liquid chromatography/mass spectrometry bioanalysis: comparison of three tandem mass spectrometric techniques for monitoring plasma phospholipids, the effect of mobile phase composition on phospholipids elution and the association of phospholipids with matrix effects
Authors: Xia Yuan‐Qing , Jemal Mohammed 
Published: June 2009

AbstractBecause plasma phospholipids may cause matrix effects in bioanalytical liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods, it is important to establish optimal mass spectrometric techniques to monitor the fate of phospholipids during method development and application. We evaluated three MS/MS techniques to monitor phospholipids using positive and negative electrospray ionization (ESI). The first technique is based on using positive precursor ion scan of m/z 184, positive neutral loss scan of 141 Da and negative precursor ion scan of m/z 153. The second technique is based on using class‐specific positive and negative selected reaction monitoring (SRM) transitions to monitor class‐representative phospholipids. The third technique, previously reported, utilizes in‐source collision‐induced dissociation (CID)‐based positive SRM of m/z 184 → 184. We recommend the all‐inclusive technique 1 for use in qualitative assessment of all classes of phospholipids and technique 2 for use in quantitative assessment of class‐representative phospholipids. Secondly, we evaluated the elution behaviors of the plasma phospholipids under different reversed‐phase mobile phase conditions. The phospholipid‐eluting strength of a mobile phase was mainly dependent on the type and amount (%) of the organic eluent and the strength increased in the order of methanol, acetonitrile and isopropyl alcohol. Under the commonly used gradient and isocratic elution schemes in LC/MS/MS bioanalysis, not all the phospholipids are eluted off the column. Thirdly, we investigated the association between phospholipids and matrix effects in positive and negative ESI using basic, acidic and neutral analytes. While the phospholipids caused matrix effects in both positive and negative ESI, the extent of ionization suppression was analyte‐dependent and was inversely related to the retention factor and broadness of the phospholipids peaks. The lysophospholipids which normally elute earlier in reversed‐phase chromatography are more likely to cause matrix effects compared to the later‐eluting phospholipids in spite of the larger concentrations of the latter in plasma. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of acetone as an alternative to acetonitrile in peptide analysis by liquid chromatography/mass spectrometry
Authors: Fritz Ria , Ruth Wolfgang , Kragl Udo 
Published: June 2009

AbstractAcetonitrile as a solvent used in liquid chromatography/mass spectrometry (LC/MS) of peptides and proteins is a relatively toxic solvent (LD50 oral; rat; 2,460 mg/kg) compared to alternatives like methanol (LD50 oral; rat; 5,628 mg/kg) and acetone (LD50 oral; rat; 5,800 mg/kg). Strategies to minimize its consumption in LC are either to reduce the inner diameter of the column or replace acetonitrile with a suitable alternative. Methanol is often recommended to replace acetonitrile in peptide analysis. In this study however, the main focus lies on another alternative solvent for LC/MS of peptides; acetone. A number of model proteins were tryptically digested and the peptide solutions were analyzed on a linear trap quadrupole (LTQ) mass spectrometer. The performances of acetonitrile, methanol and acetone were compared according to the quality of the chromatograms obtained and identification of the peptides using the BioWorks™ software developed by Thermo Scientific. In accordance to the elutropic series, acetone was found to significantly reduce the retention times of peptides separated by C18 column material with regard to acetonitrile while methanol led to increased retention times. Acetone was the superior solvent to methanol for most of the tested model proteins reaching similar sequence coverage and numbers of identified peptides as acetonitrile. We therefore propose acetone as an alternative to acetonitrile in LC/MS of peptides. Copyright © 2009 John Wiley & Sons, Ltd.
Structural characterization of pregnane glycosides from Cynanchum auriculatum by liquid chromatography on a hybrid ion trap time‐of‐flight mass spectrometer
Authors: Qi Lian‐Wen , Gu Xiao‐Jie , Li Ping , Liang Yan , Hao Haiping , Wang Guangji 
Published: June 2009

AbstractA method coupling high‐performance liquid chromatography with hybrid ion trap time‐of‐flight mass spectrometry (TOFMS) using an electrospray ionization source was firstly used to characterize ten major pregnane glycosides including one novel compound auriculoside IV from the roots of Cynanchum auriculatum Royle ex Wight. In the MS/MS spectra, fragmentation reactions of the [M+Na]+ were recorded to provide abundant structural information on the aglycone and glycosyl moieties. Experiments using TOFMS allowed us to obtain precise elemental compositions of molecular ions and subsequent product ions with errors less than 6 ppm. The pregnane glycosides in C. auriculatum were classified into two major core groups: one is caudatin characterized by the neutral loss of one ikemamic acid molecule (128 Da) from the precursor ion, and the other is kidjoranin characterized by the neutral loss of cinnamic acid (148 Da) from the precursor ion. Meanwhile, a series of sugar‐chain fragment ions provided valuable information about the compositions of the sugar residues and the sequences of the sugar chain. Logical fragmentation pathways for pregnane glycosides have been proposed and are useful for the identification of these compounds in natural products especially when there are no reference compounds available. Copyright © 2009 John Wiley & Sons, Ltd.
Electrospray ionization mass spectrometric observation of ligand exchange of zinc pyrithione with amino acids
Authors: Moriwaki Hiroshi , Okabayashi Masanori , Watanabe Takehiro , Kawasaki Hideya , Arakawa Ryuichi 
Published: June 2009

AbstractZinc pyrithione (ZnPT) is widely used as an antidandruff or antifouling reagent. However, this compound is considered toxic, such as the teratogenic effect, to aquatic lives, and it is important to clarify the mechanism of its toxicity. In this study, the interactions between ZnPT and amino acids were observed using electrospray ionization mass spectrometry (ESI‐MS) in order to obtain information on the activity of ZnPT within the living body. The ZnPT complex ([ZnPT‐ligand+Amino acid]+), in which the ligand of ZnPT was exchanged by the amino acid, was detected in ZnPT solutions mixed with one of 20 amino acids by ESI‐MS. Histidine and cysteine, in particular, showed a high reactivity with ZnPT, while serine and glycine showed a low reactivity. The complexes of ZnPT and a peptide were also observed by the ESI‐MS measurement of the solution containing ZnPT with the peptide. These results would be useful to understand the mechanism of ZnPT toxicities to living creatures. Copyright © 2009 John Wiley & Sons, Ltd.