bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of numerical eigenfunctions in the fractal‐like finite element method
Authors: Tsang D. K. L. , Oyadiji S. O. , Leung A. Y. T. 
Published: September 2004

AbstractThe fractal‐like finite element method is an accurate and efficient method to determine the stress intensity factors (SIF) around crack tips. The use of a self‐similar mesh together with the William's eigenfunctions reduce the number of unknowns significantly. The SIFs are the primary unknowns and no post‐processing is required. In all previous studies, we used the analytic eigenfunction expression to perform the global transformation. However, the eigenfunction cannot be found analytically in general crack problems. Two‐dimensional axisymmetrical cracks are considered here. The resulting static equilibrium equations in local co‐ordinates are non‐homogeneous ordinary differential equations, for which the analytic eigenfunction cannot be found completely. We use a finite difference method to determine all the eigenfunctions needed numerically. Our evaluated SIF values show very close agreement with published results. Copyright © 2004 John Wiley & Sons, Ltd.
Error estimation for geometrically non‐linear analysis of framed structures
Authors: Izzuddin B. A. , Chew A. , Smith D. Lloyd 
Published: September 2004

AbstractThis paper is concerned with the estimation of errors that arise in the geometrically non‐linear analysis of framed structures using 1D beam‐column finite elements. A quartic element is used to illustrate specific issues of error estimation relating to geometrically non‐linear analysis, this element exhibiting most of the sources of error that arise with other 1D elements. After a brief description of the quartic element, the sources of error that it manifests in geometrically non‐linear analysis are highlighted. The first source of error is due to equilibrium defaults, including contributions from finite element discretization and from the approximation of equivalent loads, whereas the second source of error is due to compatibility defaults. Next, a stress recovery method, termed the ‘Exact equilibrium recovery’ (EER) method, is proposed for the estimation of equilibrium errors due to finite element discretization. This method, specifically developed for framed structures, is element based and is shown to be more effective than other patch‐based recovery methods. An overall error estimation method is then proposed, providing separate yet combinable measures for equilibrium and compatibility errors. Finally, several examples are presented to demonstrate the effectiveness of the proposed error estimation method in the geometrically non‐linear analysis of framed structures, illustrating also the relative importance of the various sources of error that are manifested in typical problems. Copyright © 2004 John Wiley & Sons, Ltd.
Small organization mergers in arts and humanities
Authors: Toepler Stefan , Seitchek Cara , Cameron Theresa 
Published: September 2004

AbstractThis chapter discusses a case study of the merger between two relatively small organizations: a local nonprofit arts council and a public county‐level humanities commission. As this case deviates from other merger analyses that tend to focus on larger health and social service agencies, the chapter examines how well key findings of the nonprofit merger literature apply to mergers of organizations of smaller size and in other fields. Generally, we find that the merger literature so far provides sufficient guidance for nonprofit managers in fields such as the arts, where merger pressures have only now begun to mount.
Fetal cells in maternal plasma are found in a late state of apoptosis
Authors: Kolialexi Aggeliki , Tsangaris George Th , Antsaklis Aris , Mavrou Ariadni 
Published: September 2004

AbstractObjectiveThe present study was designed to give possible answers to some of the discrepancies regarding the presence or not of intact fetal cells in maternal plasma during pregnancy.Materials and Methods12‐mL peripheral blood was collected from 33 pregnant women in the second trimester: 6 mL was harvested by 3‐step Percoll gradient centrifugation and plasma cells were analyzed by FISH with X/Y chromosome specific probes. From the remaining 6 mL, plasma‐derived cells were isolated with three different gradient centrifugation protocols and apoptosis was determined following EthBr staining.ResultsThe number of cells recovered ranged from 900 to 3000. At least one Y positive signal was seen in 12 out of 17 cases with male fetuses at a frequency of 0.12% (range 0.05–0.27%). No XY cells were detected in the plasma of women carrying female fetuses. Hybridization efficiency was <60%. EthBr staining demonstrated that the majority of these cells were in their late apoptosis.ConclusionOur findings confirm the presence of intact fetal apoptotic cells in maternal plasma; however, their late apoptotic state and the low number does not as yet encourage their use in clinical practice. Copyright © 2004 John Wiley & Sons, Ltd.
Quantitative real‐time PCR technique for rapid prenatal diagnosis of Down syndrome
Authors: Hu Yali , Zheng Mingming , Xu Zhengfeng , Wang Xinru , Cui Hengmi 
Published: September 2004

AbstractObjectivesTo develop a reliable and specific technique for rapid prenatal diagnosis of Down syndrome.MethodsHigh throughput real‐time PCR technique was used to measure the DSCR3 gene dosage of genomic DNAs from uncultured amniocytes of fetuses, lymphocytes of trisomy 21 syndrome patients, and normal people, compared to conventional cytogenetic karyotype analysis.ResultsThe DSCR3/GAPDH ratio of uncultured amniocytes in trisomy 21 syndrome fetuses to normal fetuses was 1.69 ± 0.17 to 1.06 ± 0.14, respectively (p < 0.001); and the DSCR3/GAPDH ratio of lymphocytes in trisomy 21 syndrome children to normal people was 1.67 ± 0.13 to 0.99 ± 0.10, respectively (p < 0.001). Real‐time PCR technique effectively differentiates the normal fetuses from the trisomy 21 syndrome fetuses; therefore, compared to the results of the conventional cytogenetic karyotype analysis, the DSCR3/GAPDH ratios of trisomy 21 syndrome fetuses are significantly higher than those of normal fetuses.ConclusionBecause the DSCR3/GAPDH ratio of trisomy 21 syndrome fetuses is significantly higher than that of normal fetuses, the genomic DNA real‐time PCR technique may be a reliable and specific method for the rapid prenatal diagnosis of Down syndrome. Copyright © 2004 John Wiley & Sons, Ltd.
Obstetricians' agreement on fetal prognosis after ultrasound diagnosis of fetal anomalies
Authors: Bijma Hilmar H. , Wildschut Hajo I. J. , van der Heide Agnes , van der Maas Paul J. , Wladimiroff Juriy W. 
Published: September 2004

AbstractIntroductionAfter ultrasound diagnosis of a severe fetal anomaly is made, difficult decisions may arise regarding obstetric management. Guidelines have been developed to support obstetricians in decision‐making. However, it is unknown to what extent in the clinical situation, guidelines are actually supportive.ObjectivesWe aimed at: (1) determining whether obstetricians in the presence of a fetal anomaly are able to classify fetal prognosis according to guidelines; (2) establishing inter‐ and intra‐observer agreement regarding fetal prognosis.MethodsWe used three categories of fetal prognosis: category 1: the infant has no chance of survival and the abnormalities cannot be treated (1.1); or the infant has a chance of extra‐uterine survival but post‐natal use of life‐prolonging medical treatment is considered futile (1.2); category 2: the infant has a chance of extra‐uterine survival and post‐natal use of life‐prolonging medical treatment, if necessary, is considered beneficial. Five senior obstetricians categorized 100 case descriptions of severe fetal abnormalities, which were classified again after five months.ResultsFour obstetricians were able to classify 98% or more of cases. In 67% of cases, four or all obstetricians agreed on fetal prognosis. The overall kappa coefficient was 0.48 (moderate agreement). The differences between obstetricians represented systematic differences in opinions on how to classify cases. Intra‐observer agreement was 82 to 97%.ConclusionObstetricians were usually able to classify fetal prognosis according to guidelines, but in a substantial number of cases, there was a disagreement reflecting systematic differences between obstetricians. Copyright © 2004 John Wiley & Sons, Ltd.
The cell wall subproteome of Listeria monocytogenes
Authors: Schaumburg Jessica , Diekmann Oliver , Hagendorff Petra , Bergmann Simone , Rohde Manfred , Hammerschmidt Sven , Jänsch Lothar , Wehland Jürgen , Kärst Uwe 
Published: September 2004

AbstractThe surface subproteome of Listeria monocytogenes that includes many proteins already known to be involved in virulence and interaction with host cells has been characterized. A new method for the isolation of a defined surface proteome of low complexity has been established based on serial extraction of proteins by different salts at high concentration, and in all 55 proteins were identified by N‐terminal sequencing and mass spectrometry. About 16% of these proteins are of unknown function and three proteins have no orthologue in the nonpathogenic L. innocua and might be involved in virulence mechanisms. Remarkably, a relatively high number of proteins with a function in the cytoplasmic compartment was identified in this surface proteome. These proteins had neither predicted or detectable signal peptides nor could any modification be observed except removal of the N‐terminal methionine. Enolase (Lmo2455) is one of these proteins. It was shown to be present in the cell wall of the pathogen by immunoelectron microscopy and, along with heat shock factor DnaK (Lmo1473), elongation factor TU (Lmo2653), and glyceraldehyde‐3‐phosphate dehydrogenase (Lmo2459), it was found to be able to bind human plasminogen in overlay blots and surface plasmon resonance (SPR) experiments. The KD values of these interactions were determined by SPR measurements. The data indicate a possible role of these proteins as receptors for human plasminogen on the bacterial cell surface. The potential role of this recruitment of a host protease for extracellular invasion mechanisms is discussed.
Synthesis of rod copolyaramids with short flexible spacers
Authors: Boivin Julie , Brisson Josée 
Published: September 2004

AbstractRegular rigid‐flexible copolymers composed of aramid segments and aliphatic chains formed of 5 to 10 CH2 groups were synthesized using a two‐stage procedure. A first stage consisted of synthesizing, under Yamasaki–Higashi phosphorylation conditions, poly(paraphenylene terephthalamide) blocks or macromonomers of different lengths by using an excess of phenylene diamine. These macromonomers, with functionalized amine extremities, were reacted in a second stage, using the Higashi phosphorylation conditions, with a terephthalic‐acid end‐capped aliphatic amine. Macromonomer molecular weights and polydispersities were estimated from viscosity and NMR measurements, whereas for block copolymers viscosity measurements and size exclusion chromatography of allylated derivatives were performed. Block polydispersity increased with increasing length of block, but remained below 1.6. Copolymers were found to have Mw values from 2500 to 8600 g mol−1, depending on block length and aliphatic chain used. Polydispersity indices were systematically higher for block copolymers than for macromonomers, with values ranging from 1.6 to 4.7. Mv and Mw were found to be comparable for all copolyaramids, which indicates that addition of short aliphatic chains had a negligible effect on Mark–Houwink parameters. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5098–5112, 2004
Side‐chain cholesteric liquid‐crystalline elastomers derived from smectic crosslinking units: Synthesis and phase behavior
Authors: Hu Jian‐She , Zhang Bao‐Yan , Guan Yan , He Xiao‐Zhi 
Published: September 2004

AbstractNew side‐chain cholesteric liquid‐crystalline elastomers containing cholesteryl 4‐allyloxybenzoate as cholesteric mesogenic units and biphenyl 4,4′‐bis(10‐undecen‐1‐ylenate) as smectic crosslinking units were synthesized. The chemical structures of the olefinic compounds and polymers obtained were confirmed by element analysis, Fourier transform infrared, proton nuclear magnetic resonance, and carbon‐13 nuclear magnetic resonance spectra. The mesogenic properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X‐ray diffraction measurements. The influence of the concentration of the crosslinking unit on the phase behavior of the elastomers was examined. The elastomers containing less than 17 mol % of the crosslinking units revealed elasticity, reversible mesomorphic phase transition, wider mesophase temperature ranges, and higher thermal stability. The experimental results demonstrated that the glass‐transition temperature, isotropization temperature, and mesophase temperature ranges decreased with an increasing concentation of the crosslinking unit. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5262–5270, 2004
Surface characterization of plasma‐modified poly(ethylene terephthalate) film surfaces
Authors: Inagaki Norihiro , Narushim Kazuo , Tuchida Norio , Miyazaki Kohji 
Published: September 2004

AbstractPoly(ethylene terephthalate) (PET) film surfaces were modified by argon (Ar), oxygen (O2), hydrogen (H2), nitrogen (N2), and ammonia (NH3) plasmas, and the plasma‐modified PET surfaces were investigated with scanning probe microscopy, contact‐angle measurements, and X‐ray photoelectron spectroscopy to characterize the surfaces. The exposure of the PET film surfaces to the plasmas led to the etching process on the surfaces and to changes in the topography of the surfaces. The etching rate and surface roughness were closely related to what kind of plasma was used and how high the radio frequency (RF) power was that was input into the plasmas. The etching rate was in the order of O2 plasma > H2 plasma > N2 plasma > Ar plasma > NH3 plasma, and the surface roughness was in the order of NH3 plasma > N2 plasma > H2 plasma > Ar plasma > O2 plasma. Heavy etching reactions did not always lead to large increases in the surface roughness. The plasmas also led to changes in the surface properties of the PET surfaces from hydrophobic to hydrophilic; and the contact angle of water on the surfaces decreased. Modification reactions occurring on the PET surfaces depended on what plasma had been used for the modification. The O2, Ar, H2, and N2 plasmas modified mainly CH2 or phenyl rings rather than ester groups in the PET polymer chains to form CO groups. On the other hand, the NH3 plasma modified ester groups to form CO groups. Aging effects of the plasma‐modified PET film surfaces continued as long as 15 days after the modification was finished. The aging effects were related to the movement of CO groups in ester residues toward the topmost layer and to the movement of CO groups away from the topmost layer. Such movement of the CO groups could occur within at least 3 nm from the surface. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3727–3740, 2004
Microthermal analysis of the melting behavior in zone‐drawn isotactic polypropylene fibers
Authors: Ye Jiping , Hasegawa T. , Suzuki A. 
Published: September 2004

AbstractA microthermal analysis (μTA) method with an ultrahigh heating rate was applied to a zone‐drawn isotactic polypropylene fiber to evaluate the melting behaviors inherent to the microstructural changes occurring during the drawing process. The μTA melting point decreased with a reduction in the melting temperature because of the suppression of crystal reorganization and increased with an increase in the melting temperature because of the suppression of the relief of the orientation of the molecular chains, in comparison with the conventional melting point obtained by traditional differential scanning calorimetry. This study examined a convenient and powerful method for investigating the melting behavior for polymeric materials inherent to the original microstructure with less influence from thermal‐measurement heating. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3677–3681, 2004
Adhesive bonding of glassy polymer surfaces by an ultrathin layer of a semicrystalline polymer
Authors: McSwain Rachel L. , Markowitz Alison R. , Shull Kenneth R. 
Published: September 2004

AbstractTo develop a greater understanding of interfacial interactions between a semicrystalline polymer and a glassy polymer, adhesion tests were performed on very thin layers of poly(ethylene oxide) (PEO) sandwiched between two layers of poly(tetramethyl bisphenol A polycarbonate) (TMPC). The tests were designed to provide intimate contact between the surfaces while they were heated above the melting point of the PEO and cooled back to room temperature. A contact mechanics approach, based on the Johnson, Kendall, and Roberts theory, was used to determine values of the energy release rate describing the energetic driving force for crack propagation within the interfacial region. The ability to measure crack propagation at large values of the energy release rate was limited by rupture of the silicone elastomer that was used to provide a sufficiently compliant matrix for the adhesion experiment. By cycling the tensile stress at relatively low loading levels, we were able to measure fatigue crack propagation at values of the energy release rate that did not result in failure of the elastomer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3809–3821, 2004
Hydrophobic Recovery of Vacuum Ultraviolet Irradiated Polyolefin Surfaces
Authors: Truica‐Marasescu Florina , Jedrzejowski Pawel , Wertheimer Michael R. 
Published: September 2004

AbstractSummary: Film samples of low‐density polyethylene (LDPE) and biaxially oriented poly(propylene) (BOPP) were surface modified by vacuum ultraviolet (VUV) irradiation using a Kr resonant lamp at λ = 123.6 nm in low‐pressure ammonia gas, and were then stored in air. The time‐dependence of the surface properties was monitored using several complementary surface‐sensitive techniques such as contact angle goniometry (CAG), X‐ray photoelectron spectroscopy (XPS), and time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS), which allows one to determine the surface energy, and chemical composition at different depths. The relative importance of four possible mechanisms involved in surface hydrophobic recovery is discussed, and we show that in our particular case the main mechanism is rotational and/or translational motion of polymer chains and chain segments. This restructuring determines the observed “loss” of functional groups, which occurs within the first few monolayers of the surface (∼1 nm), as shown by the ToF‐SIMS results, and which leads to the observed decrease in the surface energy. In the deeper surface regions (∼10 nm) long‐lived radicals react with oxygen and water vapor upon exposure to the atmosphere, leading to an increase in the concentration of bound oxygen, as observed by XPS. Finally, CAG measurements show that the hydrophobic recovery is reversible and can be significantly reduced by cross‐linking near the surface, as illustrated by depth sensing nano‐indentation measurements on BOPP surfaces.Surface energy, γs, values as a function of storage time for VUV/NH3‐treated a) LDPE (Ed = 14.1 J · cm−2), and b) BOPP samples (Ed = 28.2 J · cm−2). Open symbols pertain to rinsed samples.magnified imageSurface energy, γs, values as a function of storage time for VUV/NH3‐treated a) LDPE (Ed = 14.1 J · cm−2), and b) BOPP samples (Ed = 28.2 J · cm−2). Open symbols pertain to rinsed samples.
Surface Analysis of Plasma‐Deposited Polymer Films, 3
Authors: Oran Umut , Swaraj Sufal , Friedrich Jörg F. , Unger Wolfgang E. S. 
Published: September 2004

AbstractSummary: Pulsed‐plasma‐deposited ethylene films were studied by time‐of‐flight static secondary ion mass spectrometry (ToF‐SSIMS) before and after exposure to ambient air. The influence of the external plasma parameters on the secondary ion mass spectra of plasma‐deposited ethylene films was investigated. From these data, information on the chemical character of the plasma‐deposited ethylene films was derived. The investigation of the effect of external plasma parameters on the chemical character of the plasma‐deposited ethylene films revealed that there were some drastic changes in the secondary ion mass spectra of the films. It was found that fragmentation and re‐arrangement of the monomer molecules in the plasma, which affects the chemical character of the deposited films, vary according to the external plasma parameters. When the plasma polymers are exposed to air, extensive oxygen incorporation occurs. The oxygen uptake is high at the beginning and then it levels of. Some indications for the formation and decay of peroxy radicals (COO•) and, subsequently, hydroperoxides (COOH) are found. It was observed that the oxygen uptake of the plasma deposited ethylene films increase when the plasma conditions become harder.Intensity ratios [m/z 12−/14− (C−/CH)] for plasma‐deposited ethylene samples versus duty cycle. Note that the unsaturated character increases with increasing m/z 12−/14− (C−/CH) intensity ratios.magnified imageIntensity ratios [m/z 12−/14− (C−/CH)] for plasma‐deposited ethylene samples versus duty cycle. Note that the unsaturated character increases with increasing m/z 12−/14− (C−/CH) intensity ratios.
Effects of volumetric ice content and strain rate on shear strength under triaxial conditions for frozen soil samples
Authors: Arenson Lukas U. , Johansen Martha M. , Springman Sarah M. 
Published: September 2004

AbstractA set of triaxial constant strain rate and constant stress tests was performed on artificially frozen soil samples to study the effect of the volumetric ice fraction, strain rate and also confining stress on the mobilized shear strength. In general, the peak shear strength increased with decreasing volumetric ice content and increasing strain rate. Pure ice samples, however, showed a peak shear strength that was higher than that for those containing about 80% ice by volume for a similar strain rate, although the loss in strength after this maximum was usually much more pronounced, reaching a lower large strain strength than that for frozen sands. The influence of the ice in samples with low ice contents was primarily noticeable at low strains, whereas the large strain behaviour was very similar to that of the unfrozen material. The tests showed the dependency of the mechanical failure and deformation mode of frozen soils on the loading conditions. It could be demonstrated further that large strains have a significant influence on the strength of frozen geo‐materials and therefore efforts should be made to establish in situ strain states when analysing the stability of frozen slopes. Copyright © 2004 John Wiley & Sons, Ltd.