bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular classification of liver cirrhosis in a rat model by proteomics and bioinformatics
Authors: Xu Xiu‐Qin , Leow Chon K. , Lu Xin , Zhang Xuegong , Liu Jun S. , Wong Wing‐Hung , Asperger Arndt , Deininger Sören , Eastwood Leung Hon‐chiu 
Published: August 2004

AbstractLiver cirrhosis is a worldwide health problem. Reliable, noninvasive methods for early detection of liver cirrhosis are not availabe. Using a three‐step approach, we classified sera from rats with liver cirrhosis following different treatment insults. The approach consisted of: (i) protein profiling using surface‐enhanced laser desorption/ionization (SELDI) technology; (ii) selection of a statistically significant serum biomarker set using machine learning algorithms; and (iii) identification of selected serum biomarkers by peptide sequencing. We generated serum protein profiles from three groups of rats: (i) normal (n = 8), (ii) thioacetamide‐induced liver cirrhosis (n = 22), and (iii) bile duct ligation‐induced liver fibrosis (n = 5) using a weak cation exchanger surface. Profiling data were further analyzed by a recursive support vector machine algorithm to select a panel of statistically significant biomarkers for class prediction. Sensitivity and specificity of classification using the selected protein marker set were higher than 92%. A consistently down‐regulated 3495 Da protein in cirrhosis samples was one of the selected significant biomarkers. This 3495 Da protein was purified on‐chip and trypsin digested. Further structural characterization of this biomarkers candidate was done by using cross‐platform matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) peptide mass fingerprinting (PMF) and matrix‐assisted laser desorption/ionization time of flight/time of flight (MALDI‐TOF/TOF) tandem mass spectrometry (MS/MS). Combined data from PMF and MS/MS spectra of two tryptic peptides suggested that this 3495 Da protein shared homology to a histidine‐rich glycoprotein. These results demonstrated a novel approach to discovery of new biomarkers for early detection of liver cirrhosis and classification of liver diseases.
Highly phosphorylated bacterial proteins
Authors: Rosen Ran , Becher Dörte , Büttner Knut , Biran Dvora , Hecker Michael , Ron Eliora Z. 
Published: August 2004

AbstractWe show in Gram‐negative and Gram‐positive bacteria the appearance of highly acidic proteins, which are highly phosphorylated. This group of proteins includes many cellular proteins, such as chaperones, biosynthetic, and metabolic enzymes. These proteins accumulate under stress conditions or under conditions, which overload the proteolytic system. Pulse chase experiments using radioactive phosphate indicate that the phosphorylated proteins have a short half‐life, suggesting that they could be degradation intermediates. Moreover, results from in vitro experiments in Escherichia coli indicated that ribosomal proteins become susceptible to proteolysis after polyphosphorylation. Therefore, it is possible that the highly phosphorylated proteins represent a group of proteins tagged for degradation by phosphorylation. Such a tagging process may be involved in a general bacterial degradation pathway.
Helicobacter pylori vaccine development based on combined subproteome analysis
Authors: Bumann Dirk , Jungblut Peter R. , Meyer Thomas F. 
Published: August 2004

AbstractEffective vaccines could provide long‐term solutions to many important infectious diseases, however, vaccine development has been hampered by the slow identification of protective antigens. Proteomics provides global information about relevant antigen properties and thus might be ideally suited for identifying promising vaccine antigen subsets. Helicobacter pylori proteomics data are stored in a proteomics database (http://www.mpiib‐berlin.mpg.de/2D‐PAGE/). In this review, we describe how a combined Helicobacter subproteome analysis resulted in the rapid identification of novel, highly protective antigens. This illustrates the great potential of pathogen proteomics for vaccine development.
The Helicobacter pylori CagA protein induces tyrosine dephosphorylation of ezrin
Authors: Selbach Matthias , Moese Stefan , Backert Steffen , Jungblut Peter R. , Meyer Thomas F. 
Published: August 2004

AbstractHelicobacter pylori is one of the most wide‐spread bacterial pathogens and infects the human stomach to cause diseases, such as gastritis, gastric ulceration, and gastric cancer. A major virulence determinant is the H. pylori CagA protein (encoded by the cytotoxin‐associated gene A) which is translocated from the bacteria into the cytoplasm of host cells by a type IV secretion system. In the host cell, CagA is phosphorylated on tyrosine residues and induces rearrangements of the actin cytoskeleton. We have previously shown that tyrosine‐phosphorylated CagA inhibits the catalytic activity of Src family kinases and induces tyrosine dephosphorylation of several host cell proteins. Here, we identified one of these proteins as ezrin by a combination of preparative gel electrophoresis, two‐dimensional electrophoresis (2‐DE) and matrix‐assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS). Specific pharmacological inhibition of Src family kinases also induces ezrin dephosphorylation. Therefore, ezrin dephosphorylation appears to be induced by CagA‐mediated Src inactivation. Ezrin is the founding member of the ezrin‐radixin‐moesin (ERM) family of proteins which are signalling integrators at the cell cortex. Since ezrin is a component of microvilli and a linker protein between actin filaments and membrane proteins, this observation has important implications for H. pylori pathogenesis and might also help to explain the development of gastric cancer.
Short Communication – Presentation of differentially regulated proteins within a web‐accessible proteome database system of microorganisms
Authors: Pleißner Klaus‐Peter , Schmelzer Peter , Wehrl Wolfgang , Jungblut Peter R. 
Published: August 2004

AbstractWeb‐accessible proteome databases represent indispensable tools for quantitative and comparative proteomics research. The majority of two‐dimensional gel electrophoresis (2‐DE) databases contains clickable 2‐DE gel images and descriptive textual information such as protein name, Mr/pI values, methods of identification, cellular localization and other information on proteins. Although a great part of the work in comparative proteomics consists of the analysis of 2‐DE gels using image analysis approaches, most proteome databases lack the ability to present protein abundance data and their alterations within experiments via the web. Now, differentially regulated proteins detected in microbial experiments by quantitative gel image analysis are presented in a web‐accessible relational database DIFF (Differentially Regulated Proteins). The DIFF database is a part of the proteome database system for microbial research available at http://www.mpiib‐berlin.mpg.de/2D‐PAGE.
Preparation of the enantiopure 1,2‐diamine monomer and its polymerization: The efficient polymeric chiral ligand of an asymmetric hydrogenation catalyst
Authors: Itsuno Shinichi , Tsuji Atsushi , Takahashi Miyuki 
Published: August 2004

AbstractAn enantiopure 1,2‐diamine monomer possessing a p‐vinylbenzyl group as a polymerizable group was synthesized from chiral 1,2‐bis(p‐hydroxyphenyl)‐N,N′‐bis(tert‐butoxycarbonyl)‐1,2‐diaminoethane. The chiral monomer was copolymerized with styrene, and this was followed by the deprotection of the tert‐butoxycarbonyl group, which yielded the polymer‐supported chiral 1,2‐diamine. The polymeric catalyst system was established with the polymeric chiral 1,2‐diamine complexed with 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl/RuCl2. In the presence of potassium tert‐butoxide (t‐BuOK), the polymeric catalyst system worked well in the asymmetric hydrogenation of aromatic ketones. The corresponding chiral secondary alcohols were obtained in quantitative yields with a high level of enantioselectivity. The insolubility of the catalyst, caused by the crosslinked structure of the polymer, made it recyclable. The polymeric catalyst was reused several times without a loss of catalytic activity. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4556–4562, 2004
Coordinate anionic ring‐opening polymerization of oxetanes with aluminum benzyl alcoholate bis(2,6‐di‐tert‐butyl‐4‐methylphenolate)
Authors: Kanoh Shigeyoshi , Takemura Atsushi , Fukuda Koh‐ichi , Chinwanitcharoen Charoen , Motoi Masatoshi 
Published: August 2004

AbstractAluminum benzyl alcoholate bis(2,6‐di‐tert‐butyl‐4‐methylphenolate) (BnOAD), which was prepared through the mixing of equimolar amounts of benzyl alcohol and methylaluminum bis(2,6‐di‐tert‐butyl‐4‐methylphenolate) (MAD), successfully polymerized four‐membered cyclic ethers in a coordinate anionic ring‐opening manner. The polymerization of 3‐(4‐bromobutoxymethyl)‐3‐methyloxetane (OxBr) with 5 mol % BnOAD proceeded slowly in toluene at 25 °C and produced sufficiently high‐molecular‐weight poly(OxBr) in a moderate yield in 24 h. The polymerization was greatly accelerated by the addition of a sterically hindered Lewis acid such as MAD, and this resulted in a nearly quantitative polymer yield within 24 h. In sharp contrast, conventional cationic polymerization with boron trifluoride etherate as a typical Lewis acid initiator produced low‐molecular‐weight poly(OxBr) along with a substantial amount of the cyclic tetramer. The polymerization of the simplest unsubstituted oxetane with BnOAD resulted in failure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4570–4579, 2004
Synthesis of asymmetric star‐branched polymers consisting of three or four different segments in composition by means of living anionic polymerization with a new dual‐functionalized 1,1‐bis(3‐chloromethylphenyl)ethylene
Authors: Higashihara Tomoya , Hirao Akira 
Published: August 2004

AbstractA series of four‐armed A2BC, AB2C, and ABC2 asymmetric star‐branched polymers with a three‐component system, the A, B, and C segments of which are polystyrene, polyisoprene, and poly(4‐trimethylsilylstyrene), respectively, have been successfully synthesized with a methodology based on living anionic polymerization with dual‐functionalized 1,1‐bis(3‐chloromethylphenyl)ethylene (1). These star‐branched polymers have well‐defined architectures and precisely controlled chain lengths, as confirmed by size exclusion chromatography, 1H and 13C NMR, vapor pressure osmometry, and static light scattering analyses. A simple and convenient one‐pot process for star‐branched polymer synthesis is an additional advantage of this methodology. One problem to be solved is that the synthetic route is limited in some cases by the inherently low reactivity of polyisoprenyllithium toward the 1,1‐diphenylethylene functionality of in‐chain‐functionalized polymers. A new four‐armed ABCD star‐branched polymer, the A, B, C, and D segments of which are polyisoprene, poly(4‐methoxystyrene), polystyrene, and poly(4‐trimethylsilylstyrene), could also be synthesized through the extension of the methodology using 1 to a four‐component system. The successful results strongly demonstrate the synthetic versatility and potential of this methodology for a wide variety of well‐defined asymmetric star‐branched polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4535–4547, 2004
Asymmetric oxidative coupling polymerization affording polynaphthylene with 1,1′‐bi‐2‐naphthol units
Authors: Habaue Shigeki , Ajiro Hiroharu , Yoshii Yasuhiro , Hirasa Tetsuya 
Published: August 2004

AbstractThe oxidative coupling polymerizations of racemic‐, (R)‐, and (S)‐2,2′‐dimethoxymethoxy‐1,1′‐binaphthalene‐3,3′‐diols were carried out with a copper catalyst with various ligands, such as N,N,N′,N′‐tetramethylethylenediamine (TMEDA), (S)‐(+)‐1‐(2‐pyrrolidinylmethyl)pyrrolidine, (−)‐sparteine, and (S)‐(−)‐2,2′‐isopropylidenebis(4‐phenyl‐2‐oxazoline) [(−)‐Phbox], under an O2 atmosphere. For example, a 10/1 (v/v) MeOH · H2O‐insoluble polymer with a number‐average molecular weight of 3.8 × 103, from a polymerization with CuCl–TMEDA followed by acetylation of the hydroxyl groups, was obtained in a 71% yield. Polymerization with (−)‐Phbox proceeded in an S‐selective manner to give a polymer with the highest negative specific rotation from the (S)‐monomer. The obtained polymer was successfully converted into a polymer with the optically pure 1,1′‐bi‐2‐naphthol unit based on the original monomer structure, which could be used as a polymeric chiral auxiliary and showed catalytic activity for the asymmetric diethylzinc addition reaction to aldehydes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4528–4534, 2004
Spectroscopic evidence for diastereomeric helical segments of polysilane bearing enantiopure (S)‐ and (R)‐3,7‐dimethyloctyl groups
Authors: Saxena Anubhav , Rai Roopali , Ohira Akihiro , Fujiki Michiya 
Published: August 2004

AbstractWe synthesized two optically active helical polysilanes, poly[(S)‐3,7‐dimethyloctyl‐3‐phenylpropylsilane] (PS1) and poly[(R)‐3,7‐dimethyloctyl‐3‐phenylpropylsilane] (PS2), bearing a flexible and rodlike silicon main chain and enantiopure alkyl side chains with (S)‐ and (R)‐chiral centers, respectively, at the γ‐positions. PS1 and PS2 underwent a thermodriven helix–helix transition at 10 °C in isooctane. Circular dichroism (CD) and UV studies demonstrated the transition characteristics, such as the transition temperature, population of right‐ and left‐handed helical motifs, global shape, and screw pitch. At −80 °C, the dissymmetry ratio suggested that a preferential right‐handed or left‐handed screw sense was present in the polymer chains of PS1 and PS2, respectively. However, above the transition temperature, the appearance of a bisignate cotton band in the CD spectra suggested that both right‐handed screw‐sense, tight helical segments and left‐handed screw‐sense, loose helical segments coexisted in the same chains of PS1 and PS2. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4518–4527, 2004
Asymmetric anionic polymerization of 2,6‐dimethyl‐7‐phenyl‐1,4‐benzoquinone methide
Authors: Uno Takahiro , Minari Masaya , Kubo Masataka , Itoh Takahito 
Published: August 2004

AbstractAsymmetric anionic polymerizations of 2,6‐dimethyl‐7‐phenyl‐1,4‐benzoquinone methide (1) were performed with various chiral anionic initiators, and the specific rotations of the obtained polymers were investigated. Optically active poly(1)s with configurational chirality were obtained with all the initiators, and a complex of fluorenyllithium (FlLi) with (−)‐sparteine [(−)‐Sp] produced poly(1) with the largest negative specific rotation ([α]435 = −26.8°). The specific rotations of poly(1)s obtained with FlLi/(−)‐Sp depended on the initiator concentration and the solvent polarity. The maximum specific rotations were obtained at an almost constant initiator concentration (ca. 0.03 mol/L), regardless of the monomer concentration, in toluene, whereas a higher initiator concentration was required in more polar solvents. These results suggested that the aggregation state of the propagating chain end significantly affected the specific rotation of poly(1). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4548–4555, 2004
Specific thermosensitive volume change of biopolymer gels derived from propylated poly(γ‐glutamate)s
Authors: Shimokuri Taiki , Kaneko Tatsuo , Akashi Mitsuru 
Published: August 2004

AbstractThermosensitive biopolymers with an amphipathic structure were synthesized through the propyl esterification of the carboxyl groups of poly(γ‐glutamic acid) (γ‐PGA). The clouding temperature on heating was controlled by the addition of different amounts of NaCl and by the degree of esterification. The clearing temperature on cooling was independent of the aqueous milieu, presumably because of the strong multiple hydrogen bonds between the polymer chains formed in the collapsed state. The hydrogel of γ‐PGA propylate crosslinked by a chemical reaction with hexamethylene diisocyanate also showed pH‐responsive and thermoresponsive shrinking, but the volume recovery was incomplete during the cooling process. A Fourier transform infrared/attenuated total reflection study showed that the incomplete volume recovery might be associated with the amide hydrogen bonding being strengthened by the chemical crosslinkage. The addition of urea made the volume change complete. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4492–4501, 2004
Preparation and characterization of polyfuran/poly(2‐fluoroaniline) conducting composites
Authors: Gök Ayşegül , Sari Beki̇r , Talu Muzaffer 
Published: August 2004

AbstractThis article deals with the chemical synthesis and characterization of poly(2‐fluoroaniline) (P2FAn) and polyfuran (PFu) homopolymers and PFu/P2FAn and P2FAn/PFu composites. P2FAn and PFu homopolymers were synthesized using ammonium persulfate and antimony (III) chloride as catalyst, respectively. These homopolymers and composites were studied in the doped state using Fourier transform infrared spectroscopy and ultraviolet–visible absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy, four‐probe conductivity technique, and Gouy Scale measurements. PFu/P2FAn and P2FAn/PFu composites were found to possess different thermal, conductivity, electronic, and morphological properties from each other when synthesis order of guest and host polymers was varied. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3359–3367, 2004
Generalizations of the AdS/CFT correspondence
Authors: Kirsch I. 
Published: August 2004

AbstractWe consider generalizations of the AdS/CFT correspondence in which probe branes are embedded in gravity backgrounds dual to either conformal or confining gauge theories. These correspond to defect conformal field theories (dCFT) or QCD‐like theories with fundamental matter, respectively. Moreover, starting from the dCFT we discuss the deconstruction of intersecting M5‐branes and M‐theory. We obtain the following results:i) Holography of defect conformal field theories. We consider holography for a general D3‐Dp brane intersection in type IIB string theory (p ∈ {3,5,7}). The corresponding near‐horizon geometry is given by a probe AdS‐brane in AdS5 × S5. The dual defect conformal field theory describes 𝒩 = 4 super Yang‐Mills degrees of freedom coupled to fundamental matter on a lower‐dimensional space‐time defect. We derive the spectrum of fluctuations about the brane embedding and determine the behaviour of correlation functions involving defect operators. We also study the dual conformal field theory in the case of intersecting D3‐branes. To this end, we develop a convenient superspace approach in which both two‐ and four‐dimensional fields are described in a two‐dimensional (2,2) superspace. We show that quantum corrections vanish to all orders in perturbation theory, such that the theory remains a (defect) conformal field theory when quantized.ii) Flavour in generalized AdS/CFT dualities. We present a holographic non‐perturbative description of QCD‐like theories with a large number of colours by embedding D7‐brane probes into two non‐supersymmetric gravity backgrounds. Both backgrounds exhibit confinement of fundamental matter and a discrete glueball and meson spectrum. We numerically compute the $\bar{\psi}\psi$ quark condensate and meson spectrum associated with these backgrounds. In the first background, we find some numerical evidence for a first order phase transition at a critical quark mass where the D7 embedding undergoes a geometric transition. In the second, we find a chiral symmetry breaking condensate as well as the associated Goldstone boson.iii) Deconstruction of extra dimensions. We apply the deconstruction method to the dCFT of intersecting D3‐branes to obtain a field theory description for intersecting M5‐branes. The resulting theory corresponds to two six‐dimensional (2,0) superconformal field theories which we show to have tensionless strings on their four‐dimensional intersection. Moreover, we argue that the SU(2)L R‐symmetry of the dCFT matches the manifest SU(2) R‐symmetry of the M5‐M5 intersection. We finally explore the fascinating idea of deconstructing M‐theory itself. We give arguments for an equivalence of M‐theory on a certain background with the Higgs branch of a four‐dimensional non‐supersymmetric (quiver) gauge theory: in addition to a string theoretical motivation, we find wrapped M2‐branes in the mass spectrum of the quiver theory at low energies.
Influence of phosphine on hatching of Cryptolestes ferrugineus (Coleoptera: Cucujidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae)
Authors: Rajendran Somiahnadar , Parveen Hajira , Begum Khamrunissa , Chethana Ramesh 
Published: August 2004

AbstractThe hatching and mortality response of 0‐ to 48‐h‐old eggs of field strains of the stored‐product insects Cryptolestes ferrugineus (Stephens), Lasioderma serricorne (F) and Oryzaephilus surinamensis (L) following phosphine fumigation for 24, 48 or 120 h at 27 (±2) °C was investigated. Hatching was delayed and reduced in the first few days in a phosphine‐resistant strain of C ferrugineus that was treated with 2.0–7.0 mg litre−1 doses for 48 h (5–80% mortality) and with 1.0–2.0 mg litre−1 for 120 h (44–84% mortality). In both the exposures there were significant increases in hatching on later days when compared with the corresponding controls. Developmental delay was, however, not evident in susceptible strains of C ferrugineus, L serricorne and O surinamensis that were exposed to phosphine for 24 h. Copyright © 2004 Society of Chemical Industry
Size effects in thin films of order–disorder ferroelectrics allowing for the depolarization field
Authors: Eliseev E. A. , Glinchuk M. D. 
Published: August 2004

AbstractFilms of order–disorder type ferroelectrics have been considered in the mean field approximation taking into account a depolarization field. It has been shown that size effects in this system could be described on the base of a bulk system equation of state with Curie temperature dependent on the film thickness. A comparison of different type ferroelectric film properties has been performed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ground‐state geometry and electronic structure of light atom clusters, especially H isotopes, Li, B, and C
Authors: March N. H. 
Published: August 2004

AbstractThe ground‐state geometry and electronic structure of light clusters remains an area of considerable current interest for both many‐body theory and experiment. We cite here recent experimental studies of H isotopes that may have important implications for energy production. Therefore a summary will first be given of quantum‐chemical results on the singly charged cationic clusters H(H2)m for some values of m ≤ 14, studied by Gobet et al. (2002). More recent theoretical work on doubly charged D clusters is also reported. Some attention is then given to results on small Li clusters, isolated in argon matrices by Kornath et al. (2003), in relation to many‐body theory. This is followed by a study of almost‐spherical cages of B and of C atoms: both neutral and charged clusters again being referred to in the case of boron. Finally, some mixtures of light atoms are considered, with special focus on BN cages and cationic hydrocarbons. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004