bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and characterisation of poliovirus mutants resistant to heating at 50°c for 30 min
Authors: Shiomi Hiroshi , Urasawa Tomoko , Urasawa Shozo , Kobayashi Nobumichi , Abe Shibobu , Taniguchi Koki 
Published: September 2004

AbstractPoliovirus is heat‐labile; on heating at 50°C for 30 min its infectivity decreases drastically and its antigenicity reverts from N to H. However, mutants resistant to heating at 50°C for 30 min from the Sabin 1 and 2 viruses were isolated by repeating the process of incubation of the virus stock at 50°C for 30 min and multiplication of the remaining virus in a cell culture. The isolated mutants were stable genetically, and maintained the rct and d markers of the parent virus. On electron microscopical examination, the mutants were observed to retain the intact morphology after being heated at 50°C for 30 min, while the parent virus was converted to empty particles devoid of RNA under the same conditions. On determination of the nucleotide sequence of the P1 region, a single nucleotide sequence substitution was detected at nucleotide no. 2741, resulting in an amino acid change from valine to alanine at the 87th position of VP1. This amino acid might be associated with the heat‐resistance of the mutants. Furthermore, it was found that the thermostable mutants obtained in this study, which are resistant to “high” temperature (50°C) for a short time (30 min), were not stable against heating at the ambient temperature (37°C) for a long time (5 or 7 days). This suggests that the inactivation at high temperature for a short time and that at ambient temperature for a long time involve different mechanisms. J. Med. Virol. 74:484–491, 2004. © 2004 Wiley‐Liss, Inc.
Hepatitis E in the south west of France in individuals who have never visited an endemic area
Authors: Mansuy Jean Michel , Peron Jean Marie , Abravanel Florence , Poirson Hélène , Dubois Martine , Miedouge Marcel , Vischi Françoise , Alric Laurent , Vinel Jean Pierre , Izopet Jacques 
Published: September 2004

AbstractA total of 431 consecutive patients from the Midi Pyrenees area with acute hepatitis with unknown etiology in 2001–2002 were tested for the presence of immunoglobulin G‐class (IgG) anti‐hepatitis E virus (HEV) antibodies. Forty‐six (10.7%) had anti‐HEV IgG, and the results were questionable for a further 17 (3.9%). Real time PCR based on TaqMan detection was used to identify HEV genome fragments in the serum of patients with positive or questionable anti‐HEV serology. HEV RNA was found in 25.4% of cases. All amplification products were sequenced and analyzed. Phylogenetic analysis revealed that all the strains were genotype 3. In conclusion, virological and epidemiological data indicate that genotype 3 viruses are circulating in the south west part of France (Midi‐Pyrenees) in patients with acute hepatitis and who have not visited recently areas in which HEV is endemic. J. Med. Virol. 74:419–424, 2004. © 2004 Wiley‐Liss, Inc.
Simplified equivalent‐circuit modelling for decoupled and partial decoupled methods in semiconductor device simulation
Authors: Dai Jing‐Fu , Chang Chia‐Cherng , Lee Jia‐Wen , Li Szu‐Ju , Tsai Yao‐Tsung 
Published: September 2004

AbstractIn this paper, we study the decoupled method which requires less memory on semiconductor device simulation. The decoupled method decouples the three equivalent circuits of semiconductor and solves them sequentially. The three equivalent circuits are formed by formulating the three partial differential equations that describe the electrical behaviour of semiconductor. Since the decoupled method solves one equation in each stage, the decoupled method uses one‐ninth memory space of the coupled method. When decoupling the three equivalent circuits, the decoupled method yields a boundary condition limitation. In order to overcome the limitation, we propose a compromising partial decoupled method which has complete boundary condition and requires four‐ninth memory space of the coupled method. The three methods are compared for computational efficiency and accuracy in the simulation of BJT. The simulation results are identical. Copyright © 2004 John Wiley & Sons, Ltd.
Wide‐band modelling of CMOS interconnections and voiding damages with the lumped element LE‐FDTD method
Authors: Alimenti F. , Impronta M. , Scorzoni A. , Roselli L. 
Published: September 2004

AbstractThis paper illustrates the application of a lumped element‐finite difference time domain (LE‐FDTD) simulator to the wide‐band modelling of CMOS interconnections. To achieve very accurate results the short‐open calibration (SOC) technique has been adopted. Specific parameters of a CMOS interconnection laterally screened by a stack of metal vias have been extracted in the two cases of an unperturbed and a purposely damaged metal line. The behaviour of void‐like defects in the metal line has been also studied using the fully three‐dimensional capabilities of the simulator. It has been demonstrated that, at least in the simulated cases, only the specific resistance is affected by damaging. Copyright © 2004 John Wiley & Sons, Ltd.
Comparison between line and surface integral formulations of the hybrid mode‐matching/two‐dimensional finite element method
Authors: Crinó Vincenzo , Tomassoni Cristiano , Mongiardo Mauro 
Published: September 2004

AbstractThe hybrid mode‐matching/two‐dimensional‐finite‐element (MM/FEM2D) technique has been proposed for the analysis of discontinuities with waveguides of arbitrary cross section; this technique combines the computational efficiency of modal analysis with the versatility and flexibility of the FEM approach.In this paper, we present in detail a surface‐integrals and a line‐integrals formulation of the hybrid MM/FEM2D technique, in case the ‘Standard Formulation’ is used as FEM2D formulation. Such formulations allow computing analytically both the normalization and the coupling integrals. Furthermore, we compare the accuracy obtained by using the line‐integrals and the corresponding surface‐integrals formulation. To these aims we present several numerical results. Copyright © 2004 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies, conformations and ab initio calculations of n‐propyltrichlorosilane
Authors: Aleksa V. , Klaeboe P. , Nielsen C. J. , Guirgis G. A. , Durig J. R. 
Published: September 2004

AbstractInfrared spectra of n‐propyltrichlorosilane (CH3CH2CH2SiCl3) were obtained in the vapour, amorphous and crystalline solid phases in the range 4000–50 cm−1. Additional spectra in argon and nitrogen matrices at 5 K were recorded before and after annealing to 20–36 K. Raman spectra of the compound as a liquid were recorded at various temperatures between 300 and 153 K and spectra of the amorphous and crystalline solids were obtained. The spectra revealed the existence of two conformers (anti and gauche) in the fluid phases and in the matrices. When the vapour was shock‐frozen on a cold‐finger at 78 K and subsequently annealed to 120–130 K, 10 Raman bands and eight IR bands of the liquid were reduced in intensity in the amorphous phase and vanished in the crystal. Frequent intensity variations were observed in the infrared spectra of argon and nitrogen matrices before and after annealing. These spectra revealed the existence of one conformer (anti) in the crystal. From intensity variations of four independent pairs of anti and gauche bands in the Raman spectra between 300 and 150 K, an average value ΔH°(gauche–anti) = 4.6 ± 0.3 kJ mol−1 was obtained in the liquid. Annealing experiments on n‐propyltrichlorosilane in the matrices demonstrate that the gauche bands vanish after annealing, revealing that the anti conformer has the lower energy. The spectra of both conformers were interpreted in detail. Ab initio and DFT calculations gave optimized geometries, infrared and Raman intensities and scaled vibrational wavenumbers for the anti and gauche conformers. The conformational energy difference derived was 7.6 and 6.4 kJ mol−1 for the HF/6–311G* and B3LYP/6–311G* basis sets, respectively, with anti being the low‐energy conformer. Copyright © 2004 John Wiley & Sons, Ltd.
Raman spectroscopy of a family of organoaluminum compounds
Authors: Beard Bruce C. 
Published: September 2004

AbstractRaman spectroscopy was used for the study of a sequential family of organoaluminum compounds. The compounds were prepared by redistribution reactions between trimethylaluminum and tri‐tert‐butoxyaluminum, leading to molecules with all possible ligand combinations. In the liquid phase, these compounds exist as dimers linked by bridging ligands involved in three‐center bonding. Terminal groups are exchanged first followed by the bridging groups. Characteristic group wavenumbers and molecular modes were compared at every stage of redistribution in the spectral range of 1100–150 cm−1. Copyright © 2004 John Wiley & Sons, Ltd.
Corrosion inhibition approach of oil production systems in offshore oilfields
Authors: Zhao L. , Teng H. K. , Yang Y. S. , Tan X. 
Published: September 2004

AbstractSynthesis and modification of imidazoline were carried out based on review of the corrosion inhibitor development and application for oilfields. A series of imidazoline compounds were synthesised through the solvent dewatering and vacuum dewatering methods. After reaction of imidazoline with ethane oxide, the produced compound was used to react with halogen hydrocarbon and polyphosphoric acid respectively. Finally an agent with performance of corrosion‐inhibition, sterilisation and anti‐scaling was obtained. The structures of the compounds were characterised by the Fourier transformation infrared spectrum. The relationships between corrosion inhibition effectiveness of the compounds and their structures were investigated so as to determine the structure of a novel corrosion inhibitor. The selected corrosion inhibitor was evaluated by a series of experiments to understand the characteristics of imidazoline derivative and some major factors associated with oil production in the oilfields of China. The experimental results showed that this corrosion inhibitor has outstanding performance of corrosion inhibition and sterilization, and is suitable for corrosion inhibition of the oil abstraction systems with high water‐content in the offshore oilfields.
Poly(4‐hexyl‐1,2,4‐triazole‐4H): An Electron Semiconducting Analogue to Regioregular Poly(hexylthiophene)
Authors: Janietz Silvia , Barche Jens , Wedel Armin , Sainova Dessislava 
Published: September 2004

AbstractSummary: For the development of n‐channel field‐effect transistors it is indispensable to look for semiconducting polymers with electrons as majority charge carriers (n‐type). In addition high electron mobility values are of significant advantage in these compounds. Polymers with electron transporting properties have been rarely investigated. Main chain polymers with strong acceptor units like 1,2,4‐triazoles‐4H are potential candidates for electron transporting materials in electronic devices. Therefore, a synthetic pathway leading to an organo‐soluble polymer consisting only of 4‐hexyl‐1,2,4‐triazole‐4H units in the main chain is presented in this work. We will report the synthesis using modified classical polycondensation. The chemical and electronic properties of the polytriazole have been investigated in detail. The material has been used to prepare “electron‐only” devices for the calculation of the electron mobility.The suggested chemical structure of poly(4‐hexyl‐1,2,4‐triazole‐4H) (PHTA).magnified imageThe suggested chemical structure of poly(4‐hexyl‐1,2,4‐triazole‐4H) (PHTA).
Influence of Mid‐Chain Radicals on Acrylate Free Radical Polymerization: Effect of Ester Alkyl Group
Authors: Sato Eriko , Emoto Tetsuya , Zetterlund Per B. , Yamada Bunichiro 
Published: September 2004

AbstractSummary: The benzene solution polymerizations of tert‐butyl acrylate (tBA) and 2‐ethylhexyl acrylate (EHA) have been investigated with respect to the effects of mid‐chain radicals (MCRs) on the rate of polymerization, the total radical concentration, the apparent rate coefficients for propagation, termination, and β‐fragmentation, the contents of unsaturated end groups and branching, and the molecular weight distribution. The EHA polymerization involves a considerably higher concentration of MCR and is more significantly affected by MCR than the tBA polymerization. The MCR content as estimated by electron paramagnetic resonance (EPR) spectroscopy during photosensitized EHA polymerization was as high as 70% of the total radical concentration at 25 °C. However, no 1H and 13C NMR resonances due to unsaturated ends and branching, respectively, were detected for the poly(EHA) obtained at 25 °C. These findings indicate that a high MCR content does not directly correspond to significant MCR effects on the polymer structure. The rate constants for mutual reaction ($k'_{\rm t}$) and β‐fragmentation (kf) of MCR were estimated for the two assumed cases where MCR was consumed solely by (i) mutual reaction, and (ii) β‐fragmentation, based on the after‐effect of the photosensitized EHA polymerization monitored by EPR spectroscopy at 25 °C; $k'_{\rm t}$ = 3.5 × 103 L · mol · s−1 and kf = 4.2 × 10−2 s−1. These rate coefficients were compared with those for reactions of structurally similar radicals.Reaction pathways of MCRs.magnified imageReaction pathways of MCRs.
Isothermal Crystallization of Poly(ε‐caprolactone) in Blend with Poly(styrene‐co‐acrylonitrile): Influence of Phase Separation Process
Authors: Madbouly Samy A. , Ougizawa Toshiaki 
Published: September 2004

AbstractSummary: The isothermal crystallization process of poly(ε‐caprolactone) (PCL) and its blend with styrene‐acrylonitrile random copolymer containing 27.5 wt.‐% acrylonitrile has been investigated as a function of crystallization and melting temperatures for different melting times in the vicinity of the lowest critical solution temperature (LCST)‐type phase diagram using DSC. The obtained results showed that the isothermal crystallization kinetics from the melt of PCL in the blend was greatly affected by the presence of SAN. For a given crystallization temperature, the crystallization half time (t0.5) in the case of PCL/SAN = 80/20 blend was much longer than the corresponding value for pure PCL. This depression in the crystallization kinetics of PCL in the blend was mainly attributed to the favorable interaction between the two components and the reduction in chain mobility as a result of increasing the Tg by adding the amorphous component (SAN). In addition, the value of t0.5 was found to be independent of the melting temperature (Tm) and melting time for pure PCL. The isothermal crystallization kinetics for samples that were crystallized after decomposition into different stages of phase separation were also investigated. A major acceleration in the crystallization kinetics was observed isothermally for the samples that had undergone phase separation in the early and middle stages. The isothermal crystallization kinetics was also analyzed based on the Avrami approach. Although the crystallization kinetics was accelerated to a great extent by the liquid‐liquid phase separation, no change in the crystallization mechanism could be predicted. Furthermore, the phase separation process of PCL/SAN blend has been studied indirectly by following the variation in t0.5 at different melting temperatures and melting times above the LCST phase diagram.Melting temperature, Tm, dependence of crystallization half time, t0.5.magnified imageMelting temperature, Tm, dependence of crystallization half time, t0.5.
Electrospinning of Chitosan
Authors: Ohkawa Kousaku , Cha Dongil , Kim Hakyong , Nishida Ayako , Yamamoto Hiroyuki 
Published: September 2004

AbstractSummary: An electrospun nonwoven fabric of a cationic polysaccharide, chitosan, was successfully prepared. The present study focuses on the effect of the electrospinning solvent and the chitosan concentration on the morphology of the resulting nonwoven fabrics. The solvents tested were dilute hydrochloric acid, acetic acid, neat formic acid and trifluoroacetic acid. As the chitosan concentration was increased, the morphology of the deposition on the collector changed from spherical beads to interconnected fibrous networks. The addition of dichloromethane to the chitosan‐TFA solution improved the homogeneity of the electrospun chitosan fiber. Under optimized conditions, homogenous (not interconnected) chitosan fibers with a mean diameter of 330 nm were prepared.Effects of the coexisting dichloromethane (MC) in the prespun chitosan‐TFA solution on the morphology of the electrospun chitosan fibers. The volume ratio of TFA:MC was 70:30 (×5 000).magnified imageEffects of the coexisting dichloromethane (MC) in the prespun chitosan‐TFA solution on the morphology of the electrospun chitosan fibers. The volume ratio of TFA:MC was 70:30 (×5 000).
Low‐Density Polyethylene Superhydrophobic Surface by Control of Its Crystallization Behavior
Authors: Lu Xiaoying , Zhang Changchun , Han Yanchun 
Published: September 2004

AbstractSummary: A simple and inexpensive method for forming a low‐density polyethylene (LDPE) superhydrophobic surface by controlling the crystallization behavior of LDPE by adjusting the crystallization time and nucleation rate has been proposed. The resulting porous surface, with hierarchical micro‐ and nanostructures on the beautiful floral designs, has a water contact angle of 173.0° ± 2.5°.A highly porous surface created by adding nonsolvent (cyclohexanone) followed by evaporation of the LDPE in a vacuum at 25 °C (left, inset shows corresponding water contact angle). Nanostructures on the florallike crystal structures (right).magnified imageA highly porous surface created by adding nonsolvent (cyclohexanone) followed by evaporation of the LDPE in a vacuum at 25 °C (left, inset shows corresponding water contact angle). Nanostructures on the florallike crystal structures (right).
Microdeformation in Heterogeneous Polymers, Revealed by Electron Microscopy
Authors: Plummer Christopher J.G. , Béguelin Philippe , Grein Chrystelle , Gensler Rudolph , Dupuits Laure , Gaillard Cedric , Stadelmann Pierre , Kausch Hans‐Henning , Månson Jan‐Anders E. 
Published: September 2004

AbstractRecent investigations of the tensile fracture behaviour of representative glassy and semicrystalline impact‐resistant polymers are reviewed, with emphasis on the microdeformation behaviour as revealed by electron microscopy of sections from bulk specimens, where the crack‐tip damage zone has been embedded and/or stained under load, and on thin films deformed in situ. The insight that such techniques have provided into the toughening mechanisms is discussed.
Morphology and Properties of Particulate Filled Polymers
Authors: Pukánszky Béla , Móczó János 
Published: September 2004

AbstractAlthough the structure of particulate filled polymers is usually thought to be very simple, often structure related phenomena determine their properties. Segregation occurs only when long flow paths and large particles are used in production. The occurrence and extent of aggregation depend on the relative magnitude of attractive and separating forces, which prevail during the homogenization of the composite; the balance of adhesive and shear forces determines structure. Fillers of small particle size always aggregate, usually leading to decreased strength and especially low impact resistance. Anisotropic particles (talc, mica, short fibers) are orientated during processing. ESR is a relatively simple technique for the estimation of orientation and orientation distribution, which are determined by processing conditions, i.e. flow pattern, shear conditions, mold filling rates, cooling conditions, etc. The orientation of the particles strongly affects composite stiffness and strength. In practice, often several factors simultaneously influence the properties of products prepared from particulate filled polymers. Separation of the effects of the influencing factors is difficult, although such knowledge would help to control composite properties. The structure and properties of injection and compression moulded PP composites containing CaCO3 or talc differs considerably from each other. The aggregation of CaCO3, the nucleating effect and the orientation of talc affect product properties. The latter are also influenced by the skin‐core structure developing during injection molding as well as by the orientation of the polymer. An example is discussed in this paper, which facilitates the identification of the effect of these factors with the help of a simple model and indicates a way in which product properties can be controlled.
Morphology and Properties of Poly(oxymethylene) Engineering Plastics
Authors: Sukhanova Tatiana , Bershtein Vladimir , Keating Mimi , Matveeva Galina , Vylegzhanina Milana , Egorov Victor , Peschanskaya Nina , Yakushev Pavel , Flexman Edmund , Greulich Stefan , Sauer Bryan , Schodt Kathleen 
Published: September 2004

AbstractComparative WAXD/SAXS/SEM/DSC structural studies of a series of semi‐crystalline poly(oxymethylene) (POM) engineering plastics, including the commercial products, homopolymer Delrin® and typical poly(oxymethylene‐co‐oxyethylene)s, and a few lab‐made POM compositions, were performed. The latter differed in their content of functional additives (present in low concentrations) and POM molecular weight characteristics. In parallel, their densities, thermal behavior/laser‐interferometric creep rate spectra (DSC/CRS) at 20‐180 °C, as well as long‐term creep resistance (LTCR) at 20 °C were studied. It has been found that introducing the nucleating agents and oxyethylene units resulted in formation of more fine spherulitic or practically non‐spherulitic structure with close‐ or loose‐packed lamellar stacks. The presence of both “thick” (5‐10 nm) and “thin” (1.5‐3 nm) lamellae in the weight ratio of ∼3:1 was shown in all cases. Close values of real POM crystallinities, not exceeding 50%, were obtained by WAXD and DSC. A predominant role of “straightened out” or slightly bent tie chains in disordered layers of isotropic POMs was presumed, resulting in segmental dynamics differently constrained by crystallites (DSC/CRS data). As a result, certain morphology ‐ density ‐ creep resistance correlations were found.
Autosomal recessive primary generalized dystonia in two siblings from a consanguineous family
Authors: Moretti Paolo , Hedera Peter , Wald John , Fink John 
Published: September 2004

AbstractWe describe the clinical features of a brother and sister with non–dopa‐responsive, childhood‐onset, generalized dystonia. The children were born to consanguineous parents, had no family history of neurologic disease, no evidence of structural or metabolic causes of dystonia, and negative testing for the GAG946 deletion mutation in the DYT1 gene. This report supports the existence of a generalized type of dystonia with autosomal recessive inheritance (DYT2). © 2004 Movement Disorder Society