bluuebunny/crossref_metadata_2025_split huggingface dataset:
Downregulation of complexin I and complexin II in the medial thalamus is blocked by N‐acetylcysteine in experimental Wernicke's encephalopathy
Authors: Hazell Alan S. , Wang Chunlei 
Published: November 2004

AbstractMetabolic dysfunction as a consequence of thiamine (vitamin B1) deficiency (TD), a model of Wernicke's encephalopathy, leads to elevation of extracellular glutamate concentration in vulnerable brain regions consistent with the development of excitotoxicity. Complexin I and complexin II are two genes labeling principally inhibitory and excitatory synapses, respectively. Because current evidence supports an important role for complexins in the modulation of neurotransmitter release, we examined the involvement of both proteins in the pathology of the medial thalamus and inferior colliculus in TD rats by immunoblotting. At the symptomatic stage, complexin I and complexin II levels in the medial thalamus were decreased by 63% and 45%, respectively, compared to control animals, but were unchanged in the inferior colliculus. These changes in thalamus were also observed using immunohistochemical methods, and seemed to be due to downregulation of both proteins because synaptophysin levels were unaffected in this brain region. In addition, cotreatment with the antioxidant N‐ acetylcysteine prevented both neuronal loss and downregulation of complexins. Our findings suggest dysregulation of excitatory and inhibitory neurotransmitter release in the medial thalamus, which is not present in the inferior colliculus. Furthermore, loss of complexin I and II in the thalamus may be mediated by processes that involve oxidative stress. Such changes in complexin levels may contribute to the pathophysiology of thalamic damage in TD, and offer a potential basis for the well‐known differences in pathology between this structure and the inferior colliculus in this disorder. © 2004 Wiley‐Liss, Inc.
The travel cost method and the economic value of leisure time
Authors: Douglas Aaron J. , Johnson Richard L. 
Published: November 2004

AbstractRecent estimates of high values for tourist related recreation USA amenity values indicate that allocation of basic water and terrestrial resources to recreation activities should be given precedence over conventional market oriented activities that often degrade or even extirpate the resource. We discuss at length the travel cost method (TCM), a survey based technique that quantifies the non‐market benefits of trips to recreation sites. The TCM has been cast in the role of an ‘umpire’ in recent resource allocation debates. Understanding the key role of the TCM in the debate will aid tourist agency officials throughout the world. This article is a U.S. Government work and is in the public domain in the U.S.A.
Comparison between Polymorphic Behaviors of Ziegler‐Natta and Metallocene‐Made Isotactic Polypropylene: The Role of the Chain Microstructure
Authors: De Rosa Claudio , Auriemma Finizia , Spera Clementina 
Published: November 2004

AbstractAn analysis of the polymorphic behavior of samples of isotactic polypropylene (iPP) prepared with heterogeneous Ziegler‐Natta catalysts is presented. A comparison with the crystallization properties of iPP samples prepared with a single center homogeneous metallocene catalyst is also shown. Samples of Ziegler‐Natta iPP samples, prepared with MgCl2‐supported catalysts, have been fractionated by extraction with boiling solvents. The irregular fraction, insoluble in diethyl ether and soluble in hexane, crystallizes from the melt almost totally in the γ form. The more stereoregular fractions crystallize instead basically in the α form. The relative amount of γ form crystallized from the melt is much lower that that observed in samples of metallocene‐made iPP containing comparable amount of defects. While in the metallocene‐made iPP the distribution of defects along the chains is random, in Ziegler‐Natta iPP samples the majority of defects are segregated in a small fraction of poorly crystallizable macromolecules or in more irregular portions of the chain, so that much longer fully isotactic sequences can be produced, leading to the crystallization of the α form. This analysis allows concluding that some fractions of Ziegler‐Natta iPP are characterized by chains with a stereo‐block microstructure, consisting in regular isotactic sequences linked to more irregular sequences.
Micro‐Rheological Modeling of Flow‐Induced Crystallization in Mixed Shear/Extensional Flows
Authors: Coppola Salvatore , Grizzuti Nino 
Published: November 2004

AbstractFlow Induced Crystallization (FIC) is the common term to indicate the acceleration in polymer crystallization kinetics due to the action of flow. When modeling FIC, two major challenges are encountered. On the one hand, the model must be able to produce quantitative reliable results, while correctly describing the coupling between the intrinsic (quiescent) crystallization kinetics and the rheological response of the polymer. On the other hand, the model must be able to describe the complex kinematics taking place in real industrial processes. In this paper, we present the predictions of a recently proposed model for FIC in the case of a mixed flow, where both shear and extensional components are present at the same time. In particular, the effects of the overall flow intensity and of relative weight between shear and extension on the enhancement in nucleation rate are presented and discussed. Some guidelines for future development are also proposed.
Blends Based on Polystyrene and Statistical Aromatic Copolycarbonates
Authors: Penco Maurizio , Sartore Luciana , Bigotti Fabio , Spagnoli Gloria , Ferrari Fabrizio , D'Antone Salvatore 
Published: November 2004

AbstractThe compatibility of polystyrene (PS) with aromatic copolycarbonates containing bisphenol A (BPA) and tetramethyl bisphenol A (TMBPA) was investigated. The simple prevision scheme developed by Sonja Krause was employed to evaluate the effect of the copolymer molecular structure on the miscibility with polystyrene. These prevision data were used to select copolycarbonates of potential interest. Statistical copolycarbonates (CPC) containing different BPA/TMBPA molar ratios were synthesised by polycondensation reaction between a mixture of the two monomers and phosgene. PS/polycarbonates blends, prepared by casting from chloroform solution, were studied with differential scanning calorimetry and optical microscopy to evaluate the components compatibility, which increases with the TMBPA copolymer content.
Engineered Green Fluorescence Proteins for Proteomics and Biomolecular Electronic Applications
Authors: Bizzarri Ranieri , Pellegrini Vittorio , Arcangeli Caterina , Ferrari Aldo , Nifosì Riccardo , Pingue Pasqualantonio , Tozzini Valentina , Giacca Mauro , Beltram Fabio 
Published: November 2004

AbstractThe discovery of the photochromic characteristics of engineered green fluorescent proteins (GFPs) allows new proteomics and biomolecular electronic applications. In particular, photoreversibility among two distinct optical states can lead to the realization of a bio‐optical high density storage memory. Here we review our recent work on an optically bistable GFP and we report the recent developments of self‐assembly methods for spatial immobilization of proteins into well‐definite 2D patterns.
(4‐Vinylpyridine‐Styrene) Copolymer as Host Polymer for Chromophoric Complexes with Potential Second Order Nonlinear Optical Properties
Authors: Borbone Fabio , Caruso Ugo , De Maria Antonella , Fusco Michela , Panunzi Barbara , Roviello Antonio 
Published: November 2004

AbstractA series of new metal containing polymers for second order nonlinear optics have been prepared by grafting Cu (II) and Pd (II) chromophoric complexes on a preformed (4‐vinylpyridine‐styrene) copolymeric backbone. The metallated polymers have been chemically and physically characterized. They show high glass transition temperatures, high thermal stability and good solubility. Their properties have been compared with analogous metallated poly(4‐vinylpyridine) samples: variations in the polymeric backbone, as well as in ligands, metal, and metallation ratio, allow to tune their properties.
On solution of Lamé equations in axisymmetric domains with conical points
Authors: Nkemzi Boniface 
Published: November 2004

AbstractPartial Fourier series expansion is applied to the Dirichlet problem for the Lamé equations in axisymmetric domains $\hat{\Omega}$⊂ℝ3 with conical points on the rotation axis. This leads to dimension reduction of the three‐dimensional boundary value problem resulting to an infinite sequence of two‐dimensional boundary value problems on the plane meridian domain Ωa⊂ℝ of $\hat{\Omega}$ with solutions un(n=0,1,2,…) being the Fourier coefficients of the solution û of the 3D BVP. The asymptotic behaviour of the Fourier coefficients un (n=0,1,2,…) near the angular points of the meridian domain Ωa is fully described by singular vector‐functions which are related to the zeros αn of some transcendental equations involving Legendre functions of the first kind. Equations which determine the values of αn are given and a numerical algorithm for the computation of αn is proposed with some plots of values obtained presented. The singular vector functions for the solution of the 3D BVP is obtained by Fourier synthesis. Copyright © 2004 John Wiley & Sons, Ltd
Intracellular Ca2+ regulation in a human prostate stromal cell culture
Authors: Wu C , Fry PM , Sui G , Fry CH 
Published: November 2004

AbstractAimsProstate stromal cell cultures are used in vitro to study the cellular pathophysiology of benign prostatic hyperplasia (BPH), but their functional properties are poorly understood. This study characterized intracellular Ca2+ ([Ca2+]i) regulation in a cultured cell line in comparison to freshly isolated cells, as a background to understanding contractile regulation and cellular proliferation in this tissue.MethodsProstate stromal cells were isolated from either PrS6 cell cultures, with an extended life span by transfection with the SV40 T‐antigen, tsA58‐U19, or freshly obtained transition zone prostate samples, primary cells. [Ca2+]i was measured in vitro with the indicator Fura‐2 by epifluorescence microscopy.ResultsPhenylephrine, high‐K+, and caffeine induced Ca2+‐transients in primary cells (resting [Ca2+]i 94 ± 8 nM, n = 29; peak 193 ± 26 nM, n = 19). In PrS6 cells resting [Ca2+]i was 96 ± 8 nM (n = 78) and in 34 of these 78 cells, 30 μM phenylephrine increased [Ca2+]i to 296 ± 28 nM. 5‐methyl‐urapidil (10–30 μM) inhibited this response in 10 of 16 cells. Spontaneous Ca2+‐transients were also observed in 91% of phenylephrine‐responsive cells, but in only 20% of non‐responsive cells (P < 0.01). Ca2+‐transients were also induced by high‐K+ solution, and 20 mM caffeine. The latter abolished the response to subsequent phenylephrine application. Depletion of intracellular Ca2+ stores by caffeine or restoration from a Ca2+‐free superfusate caused a substantial rise of [Ca2+]i.ConclusionsPrS6 prostate stromal cells express functional α1‐adrenoceptors associated with spontaneous intracellular Ca2+‐transients. They exhibit functional Ca2+ channels, intracellular Ca2+ stores, and Ca2+ entry induced by store depletion. Stromal cultures can therefore be used to characterize the cellular physiology of prostate stromal cell contraction and proliferation. © 2004 Wiley‐Liss, Inc.
On Dimensional Adaptivity For Mixed Beam‐Shell‐Structures
Authors: Wenzel Michael 
Published: December 2004

AbstractA hierarchical model for dimensional adaptivity, using mixed beam‐shell structures, is presented. Thin‐walled beam structures are often calculated on the base of beam theories. Parts of the global structure, like framework corners, are usually analyzed with shell elements in a separate model. To minimize the modeling and calculation expense, a transition element to couple beam and shell structures is used. A dimensional adaptiv algorithm is introduced to automate this the procedure of modeling and calculation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The research on physiological property of functionalized hyaluronan: interaction between sulfated hyaluronan and plasma proteins
Authors: Satoh Takashi , Nishiyama Koh , Nagahata Misao , Teramoto Akira , Abe Koji 
Published: November 2004

AbstractHyaluronan (HA) is a natural polysaccharides which has no sulfated group but high molecular weight in comparison with other glycosaminoglycans (GAGs). Previously it has been cleared up that the cell function of human keratinocytes is affected by S‐HA (HA substituted with sulfated groups). Most biomedical materials contact with blood components, proteins, cells, etc. In this study, the interaction between S‐HA and blood components is discussed, that is, plasma proteins. And the application of S‐HA for new analytical and separation method of some proteins is pointed out. None of the proteins were adsorbed to HA. Fibronectin and fibinogen were adsorbed to S‐HA, but immunoglobulin‐G and insulin were not adsorbed to it as well as heparin. However, albumin could interact only with heparin, and it did not interact with S‐HA. Furthermore S‐HA adsorbed the plasma proteins that did not adsorb to heparin. It is clear that S‐HA showed different interaction with the plasma proteins in comparison with natural sulfated polysaccharides. Copyright © 2004 John Wiley & Sons, Ltd.
Structure and properties of CE/CTBN/EP blends: II. Effect of EP on the mechanical properties and thermostability of the CE/CTBN system
Authors: Feng Yu , Fang Zhengping , Gu Aijuan 
Published: December 2004

AbstractCarboxyl‐terminated butadiene‐acrylonitrile rubber (CTBN) has often been used to improve the toughness of cyanate ester (CE) resin while sacrificing modulus and thermostability. In this paper, the addition of the appropriate amount of epoxy resin (EP) to the CE/CTBN system is shown to not only increase the modulus and thermostability of the blend, but also improve the toughness. The values of impact strength showed a maximum for the CE/CTBN/EP 100/5/5 blend. The temperature of 10 % weight loss (T10) improves from 376 °C for CE/CTBN 100/5 to 407 °C for the CE/CTBN/EP 100/5/2.5 blend. It is proposed that addition of the appropriate amount of EP can decrease the mobility and increase the stability of CTBN via the reaction between the terminal carboxyl group of CTBN and the hydroxyl group of EP. But a very high EP concentration will decrease the crosslinking density of CE, consequently reducing the mechanical properties and thermostability of the blends. Copyright © 2004 Society of Chemical Industry
Phosphonation of polysulfones via lithiation and reaction with chlorophosphonic acid esters
Authors: Lafitte Benoît , Jannasch Patric 
Published: November 2004

AbstractA noncatalytic route for the phosphonation of polysulfones was established in which lithiated sites on polysulfones were reacted with an excess of chlorophosphonic acid esters through an SNP(V) mechanism. Both the bisphenol A and biphenyl sulfone segments of the polysulfone main chain were modified according to whether brominated polysulfone or pristine polysulfone was used. Up to 50% of the repeating units of the polysulfones were modified by a careful selection of reaction parameters to avoid crosslinking. The phosphonated polysulfones in their acid form showed high thermal stability with decomposition temperatures of approximately 350 °C under nitrogen. Polysulfones with phosphonated bisphenol A segments showed good membrane‐forming properties and are candidates for components in ionomer composite membranes for fuel cells. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 273–286, 2005
Cryogenic sediment‐filled wedges, northern Delaware, USA
Authors: Lemcke Mary D. , Nelson Frederick E. 
Published: November 2004

AbstractWedge‐like sedimentary structures at two sites in northern Delaware USA are located at the erosional surface of, and extend into, channel deposits of the fluvial, mid‐Pleistocene Columbia Formation. The wedges are 0.25–0.60 m wide at the top, 1.0–1.5 m in vertical extent, contain moderate to poorly sorted, and vertically‐stratified sediment, and are overlain unconformably by a layer of wind‐blown silt. Several hypotheses for the formation and infill of the wedges were evaluated using detailed physical, stratigraphic, and sedimentological information. The most likely explanation for the features is that they are relict cryogenic structures formed by thermal‐contraction cracking in permafrost, and filled with wind‐blown sediments derived from the Columbia Formation. The wedges are believed to have formed in the tundra environment that existed in northern Delaware, south of the Laurentide Ice Sheet, during the coldest parts of the Wisconsinan glaciation. Copyright © 2004 John Wiley & Sons, Ltd.
CFTR: More than just a chloride channel
Authors: Mehta Anil 
Published: November 2004

AbstractThis review examines the cystic fibrosis transmembrane conductance regulator (CFTR) protein. After summarizing the ion channels regulated by CFTR, the review focuses on the functions of CFTR that do not relate directly to a disease mechanism based on a channelopathy. The key concept is that newly synthesized CFTR has to enter lipid vesicles which bud from the endoplasmic reticulum. This is abnormally low in ΔF508 CFTR. Normal wild type vesicular CFTR enters a recycling pool of lipid vesicles which transiently dock with the apical membrane only for CFTR to be retrieved shortly after into a sub‐apical recycling compartment. This retrieval is abnormally fast in ΔF508 CFTR. The review discusses the relationship between this process and the difficult topic of fat metabolism and then explores the possible links between abnormal fatty acid turnover and inflammatory cascades that are abnormal in cystic fibrosis. Finally the review concentrates on the emerging functions of a protein kinase (AMP‐activated kinase) which is bound near the C terminus of the CFTR protein whose functions could intergrate some of the abnormalities in lipid metabolism that result from mislocalization of CFTR in clinical disease. Pediatr Pulmonol. 2005; 39:292–298. © 2004 Wiley‐Liss, Inc.
Predicting protein functional sites with phylogenetic motifs
Authors: La David , Sutch Brian , Livesay Dennis R. 
Published: November 2004

AbstractIn this report, we demonstrate that phylogenetic motifs, sequence regions conserving the overall familial phylogeny, represent a promising approach to protein functional site prediction. Across our structurally and functionally heterogeneous data set, phylogenetic motifs consistently correspond to functional sites defined by both surface loops and active site clefts. Additionally, the partially buried prosthetic group regions of cytochrome P450 and succinate dehydrogenase are identified as phylogenetic motifs. In nearly all instances, phylogenetic motifs are structurally clustered, despite little overall sequence proximity, around key functional site features. Based on calculated false‐positive expectations and standard motif identification methods, we show that phylogenetic motifs are generally conserved in sequence. This result implies that they can be considered motifs in the traditional sense as well. However, there are instances where phylogenetic motifs are not (overall) well conserved in sequence. This point is enticing, because it implies that phylogenetic motifs are able to identify key sequence regions that traditional motif‐based approaches would not. Further, phylogenetic motif results are also shown to be consistent with evolutionary trace results, and bootstrapping is used to demonstrate tree significance. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Phenomenological description of polarization switching in ferroelectric semiconductors with charged defects
Authors: Morozovska Anna N. , Eliseev Eugene A. 
Published: December 2004

AbstractWe have proposed the phenomenological description of polarization switching peculiarities in ferroelectric semiconductors with charged defects and prevailing extrinsic conductivity. More precisely, we have modified the Landau–Ginsburg approach and shown that the macroscopic state of the aforementioned inhomogeneous system can be described by three coupled equations for three order parameters. Both the experimentally observed coercive field values, well below the thermodynamic one, and the various hysteresis loop deformations (minor, constricted and double loops) have been obtained in the framework of our model. The obtained results qualitatively explain the ferroelectric switching in such bulk ferroelectric materials as SBN single crystals doped with Ce, lead zirconate titanate (PZT) films doped with Nd, and La‐doped PZT ceramics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetooptics of quintet states of Tb3+ ion in terbium–yttrium aluminum garnet
Authors: Valiev U. V. , Gruber J. B. , Zandi B. , Rustamov U. R. , Rakhmatov A. S. , Dzhuraev D. R. , Narzullaev N. M. 
Published: December 2004

AbstractThe luminescence spectra and the degrees of magnetic circular polarization of luminescence (MCPL) have been studied in paramagnetic garnet Tb0.2Y2.8Al5O12 (YAG:Tb3+) for the radiative 4f–4f transition 5D4 ® 7F6. The features of the spectral dependencies of the MCPL degree with allowed (in symmetry) optical transitions between the Stark sublevels of the ground 7F6 and excited 5D4 multiplets of the non‐Kramers rare‐earth Tb3+ ion have been found in the YAG garnet structure. In the paramagnetic garnet Tb0.2Y2.8Al5O12 within the close ultraviolet spectral range, the non‐trivial features of the spectra of magnetic circular dichroism (MCD) have been found; they evidence a significant contribution of the quasi‐doublet states in the multiplets 5D3, 5G5 and 5L10 to magnetooptics of the 4f–4f transitions. The results of numerical calculations of the energy and wave functions have been presented for some Stark sublevels of the 5D4 and 7F6 multiplets of the Tb3+ ion in the crystalline field of D2 symmetry. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phosphorus–hydrogen complexes in LEC‐grown InP
Authors: Ulrici W. , Kwasniewski A. , Czupalla M. , Neubert M. 
Published: December 2004

AbstractIn LEC‐grown InP, about 30 sharp vibrational absorption lines are measured in the frequency region 2200 to 2350 cm–1. All these lines are due to phosphorus‐hydrogen stretching modes. Experiments on InP containing both hydrogen and deuterium finally proved that the line at 2202.4 cm–1 is due to a single hydrogen atom bonded to P in an indium vacancy (VIn) and that the line at 2315.6 cm–1 is due to the complex of four P–H bonds in an VIn. In InP:H:D, this VInH4 complex gives rise to six vibrational lines in the region of P–H modes and six lines in the region of P–D modes because of the five different types of VInHnDm complexes. The measured frequencies of these 12 lines are in excellent agreement with those obtained from ab initio calculations reported in the literature. Additional P–H complexes are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reply to “Comment on ‘Orbital ordering and orbital fluctuations in transition metal oxides’” [phys. stat. sol. (b) 242, No. 4, 962 (2005)]
Authors: Oleś Andrzej M. 
Published: December 2004

AbstractWe point out that the high degeneracy of 3T1g ground state of V3+ ions in LaVO3, used to derive the spin‐orbital model analyzed in the previous paper [A. M. Oleś, phys. stat. sol. (b) 236, 281 (2003)], allows for the orbital fluctuations which stabilize the ferromagnetic bonds in the C‐type antiferromagnetic phase of cubic vanadates. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)