bluuebunny/crossref_metadata_2025_split huggingface dataset:
TTV infection in children born to mothers infected with TTV but not with HBV, HCV, or HIV
Authors: Komatsu Haruki , Inui Ayno , Sogo Tsuyoshi , Kuroda Koichi , Tanaka Toshio , Fujisawa Tomoo 
Published: September 2004

AbstractThe TT virus (TTV) was isolated recently from the serum of a patient with post‐transfusion hepatitis. TTV infection is widespread in the general population, and its prevalence increases continuously with age. The pathogenic role of TTV in liver disease remains controversial, and the source of transmission is still unclear. We investigated the pathogenicity and epidemiology of TTV infection in infants born to TTV DNA‐positive mothers. Enrolled in this study were 22 mother–child pairs testing negative for antibodies to hepatitis B, hepatitis C, and the human immunodeficiency viruses (HIVs). The children were followed for 30 months after birth. Serum TTV DNA was detected by N22‐PCR, and the PCR products were cloned and sequenced. The prevalence of TTV infection in children increased with age. Of the 22 children, 13 (59%) became positive for TTV DNA during the follow‐up period. Of these 13 children, 6 (46%) had elevated levels of serum alanine aminotransferase (ALT), although the elevations were transient and mild. TTV viremia was not associated significantly with the abnormal ALT levels. Children with TTV viremia developed neither severe liver disease nor fulminant hepatitis. Phylogenetic analysis showed that, in 11 (85%) of the 13 pairs, the mother and child had the same genotype at the first PCR‐positive time point. Among those 11 mother–child pairs, 6 (55%) had identical TTV nucleotide sequences. However, the genotype of predominant clones changed in 5 (50%) of 10 children who were positive for TTV DNA at two or more time points during the follow‐up period. In conclusion, this study did not provide evidence that TTV infection is related to liver disease in children. Although the main source of TTV infection in children is presumed to be their mothers, transmitted via non‐parenteral routes in the course of daily contact, intrafamilial carriers may also be sources of TTV infection. J. Med. Virol. 74:499–506, 2004. © 2004 Wiley‐Liss, Inc.
Flexible GMRES‐FFT method for fast matrix solution: application to 3D dielectric bodies electromagnetic scattering
Authors: Chen R. S. , Ding D. Z. , Fan Z. H. , Yung Edward K. N. , Chan C. H. 
Published: September 2004

AbstractIn this paper, the electromagnetic wave scattering is analysed by the efficient Krylov subspace iterative fast Fourier transform (FFT) technique in terms of the electric field integral equation (EFIE) for a dielectric body of general shape, inhomogeneity, and anisotropy. However, when the permittivity of the scatter becomes large, the convergence rate of Krylov subspace iterative methods slow down. Therefore, the inner–outer flexible generalized minimum residual method (FGMRES) is used to accelerate the iteration. As a result, nearly 10 times convergence improvement is achieved for high permittivity cases. Copyright © 2004 John Wiley & Sons, Ltd.
Reexpression of vimentin in differentiated neuroblastoma cells enhances elongation of axonal neurites
Authors: Dubey Maya , Hoda Sadaf , Chan Walter K.‐H. , Pimenta Aurea , Ortiz Daniela D. , Shea Thomas B. 
Published: September 2004

AbstractVimentin (Vm) is initially expressed by early neuronal precursors in situ and in culture. Vm is essential for neuritogenesis at least in culture and is gradually replaced by neurofilaments (NFs) because of down‐regulation of Vm expression. This period is accompanied by a slowing of axonal elongation. We examined whether continued expression of Vm could foster continued axonal elongation. NB2a/d1 cells differentiated with dibutyryl cAMP were transfected with constructs expressing Vm or the middle‐molecular‐weight NF subunit (NF‐M) each conjugated to green fluorescent protein (GFP). Axonal neurites of cells expressing GFP‐Vm were 30% longer than those of nonexpressing cells, or cells expressing GFP‐M, and exhibited a decrease in neurite caliber. Expression of GFP‐M did not enhance axonal neurite length but significantly increased caliber. These findings provide further evidence of a role for Vm in axonal outgrowth. Culturing of nontransfected cells on laminin increased neurite length, but cells expressing GFP‐Vm demonstrated an equivalent increase whether cultured on laminin or culture plastic. Axonal neurites of cells expressing GFP‐Vm turned to avoid a nonfavorable substrate (nitrocellulose), but culturing of these cells on nitrocellulose did not impair axonal outgrowth. These latter findings indicate that the more robust outgrowth following reexpression of Vm is independent of a favorable or nonfavorable substrate but that axonal neurites of these cells still interact with the substrate to the extent that the substrate can influence directionality. © 2004 Wiley‐Liss, Inc.
Metallothionein I and II mitigate age‐dependent secondary brain injury
Authors: Natale JoAnne E. , Knight Jay Brandon , Cheng Ying , Rome Justin E. , Gallo Vittorio 
Published: September 2004

AbstractBoth the immediate insult and delayed apoptosis contribute to functional deficits after brain injury. Secondary, delayed apoptotic death is more rapid in immature than in adult CNS neurons, suggesting the presence of age‐dependent protective factors. To understand the molecular pathobiology of secondary injury in the context of brain development, we identified changes in expression of oxidative stress response genes during postnatal development and target deprivation‐induced neurodegeneration. The antioxidants metallothionein I and II (MT I/II) were increased markedly in the thalamus of adult C57BL/6 mice compared to mice <15 days old. Target deprivation generates reactive oxygen species that mediate neuronal apoptosis in the central nervous system; thus the more rapid apoptosis observed in the immature brain might be due to lower levels of MT I/II. We tested this hypothesis by documenting neuronal loss after target‐deprivation injury. MT I/II‐deficient adult mice experienced greater thalamic neuron loss at 96 hr after cortical injury compared to that in controls (80 ± 2% vs. 57 ± 4%, P < 0.01), but not greater overall neuronal loss (84 ± 4% vs. 79 ± 3%, MT I/II‐deficient vs. controls). Ten‐day‐old MT I/II‐deficient mice, however, experienced both faster onset of secondary neuronal death (30 vs. 48 hr) and greater overall neuronal loss (88 ± 2% vs. 69 ± 4%, P = 0.02). MT I/II are thus inhibitors of age‐dependent secondary brain injury, and the low levels of MT I/II in immature brains explains, in part, the enhanced susceptibility of the young brain to neuronal loss after injury. These findings have implications for the development of age‐specific therapeutic strategies to enhance recovery after brain injury. © 2004 Wiley‐Liss, Inc.
Interleukin‐1: A master regulator of neuroinflammation
Authors: Basu Anirban , Krady J. Kyle , Levison Steven W. 
Published: September 2004

AbstractInterleukins 1α and 1β (IL‐1) are very potent signaling molecules that are expressed normally at low levels, but are induced rapidly in response to local or peripheral insults. IL‐1 coordinates systemic host defense responses to pathogens and to injury and not surprisingly it has similar effects within the central nervous system (CNS). Numerous reports have correlated the presence of IL‐1 in the injured or diseased brain, and its effects on neurons and nonneuronal cells in the CNS, but it is only recently that the importance of IL‐1 signaling has been recognized. This article reviews studies that demonstrate that IL‐1 is at or near the top of the hierarchical cytokine signaling cascade in the CNS that results in the activation of endogenous microglia and vascular endothelial cells to recruit peripheral leukocytes (i.e., neuroinflammation). The IL‐1 system thus provides an attractive target for therapeutic intervention to ameliorate the destructive consequences of neuroinflammation. © 2004 Wiley‐Liss, Inc.
Effect of the lanthanide ionic radius on the Raman spectroscopy of lanthanide agardite minerals
Authors: Frost Ray L. , Erickson Kristy L. , Weier Matt L. , McKinnon Adam R. , Williams Peter A. , Leverett Peter 
Published: September 2004

AbstractRaman microscopy was used to study the Raman spectra of a series of rare earth element agardites ACu6(AsO4)3(OH)6 ·3H2O, where A = lanthanide3+. These minerals have a porous framework similar to that of zeolites with a structure based on (A3+)1−x(A2+)xCu6(OH)6(AsO4)3−x(AsO3OH)x. Two sets of AsO stretching vibrations were found and assigned to the vibrational modes of AsO4 and HAsO4 units. The position of selected bands was found to be sensitive to the lanthanide ionic radius. Raman spectra of the low‐wavenumber region are complex. Bending modes of the AsO4 and HAsO4 units were found to be sensitive to the ionic radius of the lanthanide ion. Linear relationships between positions of the Raman bands were derived, with correlation coefficients >0.90. Copyright © 2004 John Wiley & Sons, Ltd.
Production of fermentable media from vine‐trimming wastes and bioconversion into lactic acid by Lactobacillus pentosus
Authors: Bustos Guadalupe , Moldes Ana Belén , Cruz José Manuel , Domínguez José Manuel 
Published: September 2004

AbstractTrimmings of vineshoots, an agricultural waste with little use, were hydrolysed with dilute sulphuric acid (1–5%) in order to obtain sugar solutions suitable as fermentation media. The operational conditions for hydrolysis were selected on the basis of both the generation of hemicellulosic sugars (mainly xylose) and glucose and the concentrations of reaction byproducts affecting fermentation (furfural, hydroxymethylfurfural and acetic acid). Hemicellulosic hydrolysates were supplemented with nutrients and fermented with Lactobacillus pentosus, without any previous detoxification stage, to produce lactic acid. Under the best operational conditions assayed (3% H2SO4 and 15 min), 21.8 g lactic acid l−1 was produced (QP = 0.844 g l−1 h−1, YP/S = 0.77 g g−1), which represents a theoretical yield of 99.6%. Acetic acid was the primary byproduct formed from xylose, at about 25% of the lactic acid level. Copyright © 2004 Society of Chemical Industry
Effects of drought stress and its sudden relief on free radical processes in barley
Authors: Goodman Bernard A , Newton Adrian C 
Published: September 2004

AbstractThe generation of free radicals and other paramagnetic species has been investigated by electron paramagnetic resonance (EPR) spectroscopy in leaves of barley plants during and after release of drought stress. Three cultivars were studied; the mlo‐resistant spring barley cultivars, Atem and Krona, along with the cultivar Golden Promise, with the wild‐type dominant Mlo. In the cultivar Atem, which exhibits a partial loss of resistance to powdery mildew after relief of drought stress, the free radical levels were elevated in the drought‐stressed samples compared with those seen in the controls, but they returned rapidly to the control levels after release of the stress. The other two cultivars showed little or no change in the free radical signal for any of the treatments. A sizeable increase in the level of a mononuclear Fe(III) complex was seen in the droughted samples (compared with the levels in the watered controls), and these elevated levels remained after release of the stress. These observations are discussed in the context of molecular processes in the mesophyll cells, where activation of plasma membrane H + ‐ATPase by 14‐3‐3 proteins leads to a decrease in pH. This, in turn, perturbs the Fe(II) speciation in favour of more easily oxidized complexes, and results in the generation of the mononuclear Fe(III) complex. The greater change in free radical activity in Atem as a result of drought stress compared with that seen with the other cultivars indicates that it is affected to a greater extent by the stress. Copyright © 2004 Society of Chemical Industry
Production of a root‐specific flavour compound, 2‐hydroxy‐4‐methoxy benzaldehyde by normal root cultures of Decalepis hamiltonii Wight and Arn (Asclepiadaceae)
Authors: Giridhar P , Rajasekaran T , Ravishankar GA 
Published: September 2004

AbstractThe flavour compound 2‐hydroxy‐4‐methoxy benzaldehyde from normal roots of swallow root (Decalepis hamiltonii) raised in vitro was extracted with dichloromethane, evaporated to dryness and dissolved in ethanol for qualitative (TLC) and quantitative (GC‐MS) analysis. Maximum root biomass and the maximum content of flavour compound (40 ± 2.1 µg g−1 dry weight) were recorded after 45 days of growth on Murashige and Skoog medium containing 1.0 mg l−1 α‐naphthaleneacetic acid. Copyright © 2004 Society of Chemical Industry
Formation and electrochemical behaviour of poly(pyrrole) coatings on steel substrates
Authors: Hamer W. J. , Koene L. , de Wit J. H. W. 
Published: September 2004

AbstractThis paper focuses on the deposition process and the semi‐conductive properties of PPy layers on steel. The polymerisation of PPy was performed galvanostatically on steel in an aqueous solution of 0.1 M pyrrole and 0.1 M oxalic acid (H2C2O4) using a current density of 1 mA/cm2. The build‐up of a ferrous oxalate (FeC2O4) layer, which seals the seel substrate surface, is initially observed. PPy layers made by this method are always doped with oxalate anions. A mechanism is proposed in which PPy deposits at sites where ferrous oxalate is dissolved. PPy is a semiconductor, just like oxide films formed naturally on some metals. Mott‐Schottky diagrams for 9.0, 11.6 and 15.0 kHz suggests a frequency dependence of the dielectric constant of polypyrrole (εPPy). The flatband potential EFB was about − 0.39 V vs. NHE and the charge carrier density was estimated to be about 5 · 1020 m−3. Also, in earlier work by Rammelt et al. and by Miller and Bockris (using different electrolytes and substrate materials) a frequency dependence has been found for a constant phase element that was used to describe the space charge capacitance CSC. The frequency dependence observed can partly be ascribed to surface roughness, which seems experimentally supported by SEM‐research.
Urban and marine corrosion: Comparative behaviour between field and laboratory conditions
Authors: Iribarren Laco J. I. , Liesa Mestres F. , Cadena Villota F. , Bilurbina Alter L. 
Published: September 2004

AbstractA detailed study of the corrosion phenomena of carbon steel has been investigated in this work by means of the comparison of field and laboratory tests. Two areas of the metropolitan area of Barcelona (Spain) were selected to carry out the field tests, whereas two different solutions of sodium chloride and sodium hydrogen sulfite were used to simulate the field conditions by means of cyclic laboratory tests. The corrosion rate has been evaluated from the weight loss of the specimens and the morphology surface has been visualized by optical and scanning electron microscopy. Corrosion products and contaminants have been analyzed by X‐ray diffraction and energy‐dispersive X‐ray spectroscopy, respectively. The penetration results can be adjusted to the Passano equation and the corrosivity degree can be assigned in accordance with ISO standards.A correlation between field and laboratory tests has been found, by comparing the specimens with the same degree of corrosion, showing the validity of the accelerated laboratory tests in order to simulate the field conditions.
Microbial consortium influence upon steel corrosion rate, using the electrochemical impedance spectroscopy technique
Authors: Hernández‐Gayosso M. J. , Zavala‐Olivares G. , Ruiz‐Ordaz N. , García‐Esquivel R. , Mora‐Mendoza J. L. 
Published: September 2004

AbstractThe Electrochemical Impedance Technique was used to evaluate the influence of a microbial consortium, isolated from a gas pipeline, upon API XL52 steel corrosion rate. The bacteria growth exhibited two different kinetics behavior, one for the plancktonic and the other for the sessile phase. The sessile bacteria were found to be the main responsible for the corrosion rate increment observed during the experiments and no relationship between the plancktonic microorganisms and the corrosion rate increment was found.The diagrams obtained from the electrochemical impedance measurements, indicated a biofilm formation and that the system changed from activation to diffusion control. Although the system was under diffusion control, an increment on the corrosion rate was detected, and a localized corrosion process was induced. The results were complemented with some surface analysis using Scanning Electron Microscopy.
Synthesis and Characterisation of Terminal Carbohydrate Modified Poly(dimethylsiloxane)s
Authors: Henkensmeier Dirk , Abele Bors Cajus , Candussio Anton , Thiem Joachim 
Published: September 2004

AbstractSummary: In the 1990's, carbohydrate modified silicones were developed as a novel class of hydrophilic modified silicones which are now ready for marketing and industrially available, mainly as ingredients of cosmetic formulations. This report focuses on the synthesis of α,ω‐carbohydrate modified linear poly(dimethylsiloxane)s by hydrosilylation reactions. Thus, a series of carbohydrate derivatives was synthesised and reacted with a hydrodimethylsilyl‐terminated poly(dimethylsiloxane) applying Speier's catalyst. The resulting oils were characterised by MALDI TOF MS and NMR spectroscopy. Deprotection gave a series of novel amphiphilic modified silicones, which were more viscous than their protected analogues, due to hydrogen bonding.General structure of the amphiphilic carbohydrate modified poly(dimethylsiloxane)s.magnified imageGeneral structure of the amphiphilic carbohydrate modified poly(dimethylsiloxane)s.
Effect of Tacticity on the Structure of Poly(1‐octadecene)
Authors: VanderHart David L. , Pérez Ernesto , Bello Antonio , Vasquez Jaime , Quijada Raúl 
Published: September 2004

AbstractSummary: A sample of poly(1‐octadecene), synthesized with a highly active heterogeneous Ziegler‐Natta catalyst, has been fractioned with heptane, giving soluble and insoluble fractions. Both fractions and the original polymer have been characterized by size exclusion chromatography, solution and solid‐state 13C NMR, DSC and X‐ray diffraction. The results show that the fractionation occurs on the basis of both molecular mass and tacticity differences, with the atactic content concentrated in the lower molecular mass chains. Thus, the soluble fraction, having a lower average molecular mass than the original sample, consists predominantly of atactic chains, whereas the insoluble fraction is mainly isotactic. The analysis of the solid‐state structure reveals that both atactic and isotactic fractions are able to crystallize, although their crystalline structures are different. The NMR and X‐ray data together support the “most probable” structure for the isotactic polymer advanced by Turner‐Jones. That structure is characterized by an orthorhombic crystal form, where a) the backbone crystallizes in a quaternary helical conformation, b) the sidechains are packed in a way analogous to orthorhombic polyethylene, and c) successive sidechains are conformationally inequivalent. Support for points b) and c) are respectively found in the chemical shift of the sidechains and in the splittings observed for backbone carbons and for some sidechain carbons located near the points of attachment. In addition, there is evidence that the mobility of sidechain sites at points near both the bonded and free ends are not uniform from chain to chain. On the other hand, the crystal form for the atactic polymer shows only sidechain order with some support for the notion that this order approximates the disordered hexagonal rotator phase of the alkanes.X‐ray diffractograms of the three poly(1‐octadecene) samples.magnified imageX‐ray diffractograms of the three poly(1‐octadecene) samples.
Second Order Nonlinear Optical Performances of Polymers Containing Imidazole and Benzimidazole Chromophores
Authors: Carella Antonio , Centore Roberto , Sirigu Augusto , Tuzi Angela , Quatela Alessia , Schutzmann Stefano , Casalboni Mauro 
Published: September 2004

AbstractSummary: Condensation polymers based on two different NLO‐active chromophores, namely 2‐[4‐[(4‐N,N‐dihydroxyethylamino)phenylazo]phenyl]‐5(6)‐nitrobenzimidazole (BZI) and 2‐[4‐(4‐N,N‐dihydroxyethylamino)phenylazo]‐4,5‐dicyanoimidazole (IMI), have been synthesized and their basic properties measured. The second order NLO properties of poled polymers were investigated by SHG procedures at different temperatures (35, 65 and 85 °C) and exposure times. Resonance free d33 coefficients (λ = 1 368 nm) took values in the range 1.8–4.0 pm · V−1, but the time stability of their SHG signal was fairly acceptable, particularly for the high Tg (e.g. 188 °C) polymer for which a relaxation time (at 25 °C) of 2.8 years has been determined.BZI and IMI chromophores.magnified imageBZI and IMI chromophores.
Cellulose Acetate‐graft‐Poly(hydroxyalkanoate)s: Synthesis and Dependence of the Thermal Properties on Copolymer Composition
Authors: Teramoto Yoshikuni , Ama Shoko , Higeshiro Tomokazu , Nishio Yoshiyuki 
Published: September 2004

AbstractSummary: Several different series of cellulose acetate‐graft‐poly(hydroxyalkanoate)s (CA‐g‐PHAs) were synthesized over a wide range of compositions by the graft copolymerization of lactic acid, L‐lactide, (R,S)‐β‐butyrolactone, δ‐valerolactone and ε‐caprolactone onto the residual hydroxyl positions of CA, by virtue of a suitable catalyst, solvent and procedure for each individual case. To achieve a diversity of molecular architectures of the respective graft copolymer series, the degree of acetyl substitution (acetyl DS) of the CA starting material was also varied, resulting in different levels of the intramolecular density of grafts. The CA‐g‐PHAs thus obtained were subjected to differential scanning calorimetric measurements and the relationship between their molecular structure and thermal transition behavior was estimated, in comparison with some semi‐empirical equations available for polymer blends or comb‐like polymers. In particular, the composition dependence of the Tgs of the graft copolymers was represented well in terms of a formula proposed by Reimschuessel for comb‐like polymers, when CAs of acetyl DS ≈2 were employed as a trunk polymer. The deviation of the glass transition data from the model function was discussed in connection with the manner of graft modification.
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Codes and invariant theory
Authors: Nebe G. , Rains E. M. , Sloane N. J. A. 
Published: September 2004

AbstractThe main theorem in this paper is a far‐reaching generalization of Gleason's theorem on the weight enumerators of codes which applies to arbitrary‐genus weight enumerators of self‐dual codes defined over a large class of finite rings and modules. The proof of the theorem uses a categorical approach, and will be the subject of a forthcoming book. However, the theorem can be stated and applied without using category theory, and we illustrate it here by applying it to generalized doubly‐even codes over fields of characteristic 2, doubly‐even codes over ℤ/2fℤ, and self‐dual codes over the noncommutative ring 𝔽q + 𝔽q u, where u2 = 0. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)