bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frog p26olf, a molecule with two S100‐like regions in a single peptide
Authors: Miwa Naofumi , Kawamura Satoru 
Published: March 2003

AbstractAn S100‐like calcium‐binding protein, p26olf, was originally isolated from the frog (Rana Catesbeiana) olfactory epithelium with four chromatographical steps. The primary structure of p26olf contains two S100‐like regions aligned in tandem with four functional EF‐hands. At 100 mM K+, wild‐type p26olf binds Ca2+ with a Kd value of 22 μM and a Hill coefficient of 2.0. Each EF‐hand seems to have different affinity for Ca2+: it is high in EF‐A and ‐B and low in EF‐C and ‐D. In our Ca2+‐binding model, the order of Ca2+‐binding to p26olf is EF‐B, EF‐A, EF‐C, and EF‐D. Expression of mRNA of p26olf is detected in various frog tissues: it is high in the olfactory epithelium, lung, and spleen, moderate in brain, retina, heart, and kidney, and low in liver and muscle. Immunohistochemical studies revealed that p26olf is prominently localized in the cilia of both olfactory and lung respiratory epithelium and especially enriched in the distal segment of the olfactory cilia. Several proteins in the olfactory cilia bind to p26olf in the presence of Ca2+, suggesting that they are possible target proteins of p26olf. One of these target proteins is immunologically identified as a β‐adrenergic receptor kinase‐like protein. In the olfactory cilia, p26olf may have some roles in the olfactory transduction or adaptation through interaction with this β‐adrenergic receptor kinase‐like protein. Microsc. Res. Tech. 60:593–599, 2003. © 2003 Wiley‐Liss, Inc.
Effect of hypoglycemia on brain glycogen metabolism in vivo
Authors: Choi In‐Young , Seaquist Elizabeth R. , Gruetter Rolf 
Published: March 2003

AbstractThe brain contains a small but significant amount of glycogen, which has long been considered to play an insignificant role in the brain. In this study, brain glycogen metabolism was measured using 13C NMR spectroscopy at 9.4 T. Brain glycogen metabolism was modulated by hyperinsulinemia resulting in a net accumulation. The role of glycogen in maintaining brain function is unknown; one possibility is that it may serve as an endogenous glucose reservoir to protect the brain against severe hypoglycemia. To address this possibility, rats were subjected to insulin‐induced moderate hypoglycemia and when the level of brain glucose approached zero, brain glycogen content began to decrease gradually, demonstrating utilization of this glucose reservoir. The brain glycogen signal never became undetectable, however, even during 2 hr of hypoglycemia. When plasma and brain glucose concentrations were restored, glycogen increased and the concentration exceeded the pre‐hypoglycemic level by several‐fold. The data suggest that brain glycogen can provide fuel for extended periods of time when glucose supply is inadequate. Furthermore, brain glycogen can rebound (super‐compensate) after a single episode of hypoglycemia. We postulate that brain glycogen serves as an energy store during hypoglycemia and that it may participate in the creation of reduced physiological responses to hypoglycemia that are involved in a symptom often observed in patients with diabetes, hypoglycemia unawareness. © 2003 Wiley‐Liss, Inc.
Miscibility and interactions in blends of two proton‐donating polymers: Poly(acrylic acid)/poly(p‐vinylphenol) blends
Authors: Li Xue‐Dong , Goh S. H. 
Published: March 2003

AbstractBlends of poly(acrylic acid) (PAA) and poly(p‐vinylphenol) (PVPh) were prepared from N,N‐dimethylformamide (DMF) and ethanol solutions. The DMF‐cast blends exhibited single Tg's, as shown by modulated differential scanning calorimetry, whereas the ethanol‐cast blends had double Tg's. Fourier transform infrared spectroscopy showed that there was a specific interaction between PAA and PVPh in the DMF‐cast blends. The single‐Tg blends cast from DMF showed single‐exponential decay behavior for the proton spin–lattice relaxation in both the laboratory frame and the rotating frame, indicating that the two polymers mixed intimately on a scale of 2–3 nm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 789–796, 2003
A review of fungal antagonists of powdery mildews and their potential as biocontrol agents
Authors: Kiss Levente 
Published: March 2003

AbstractThere are approximately 40 fungal species that have so far been reported as natural antagonists of powdery mildews or have been tested as their potential biocontrol agents. This review summarizes the published data on their identification, taxonomy, ecology, modes of action and biocontrol efficacy. The results obtained with the two products already registered, AQ10 Biofungicide® and Sporodex®, are also discussed.© 2003 Society of Chemical Industry
Novel Preparation of Asymmetric Liposomes with Inner and Outer Layer of Different Materials
Authors: Xiao Zhongdang , Huang Ninping , Xu Minhua , Lu Zuhong , Wei Yu 
Published: March 2003

Abstract
Asymmetric liposomes whose inner and outer layer with different materials, which are very useful in liposome and membrane research, have been prepared layer by layer from reverse micelles. In general, the diameters of the liposomes ranged from 30 nm to 100 nm. Fluorescein quenching experiment showed that asymmetric liposomes with inner layer being lipid and outer single-chain [(bpy)2Ru(diazafluorenone)(CH2)15CH3](PF6)2 had been success-fully prepared. The half-life of flip-flop of bilayer is estimated for 17 days. The method present is of significance in liposome and membrane study.
Synthesis and DNA Binding Property of a Novel Peptide Nucleic Acid that Contains cis-4-Adeninyl-l-prolinol Unit
Authors: Shigeyasu Masanori , Kuwahara Masayasu , Sisido Masahiko , Ishikawa Teruhiko 
Published: March 2003

Abstract
A novel oxy-peptide nucleic acid that contains a cis-4-adeninyl-l-prolinol unit in the main chain (PPNA) was synthesized. The peptide nucleic acid with nine adenine units [PPNA(A9)] hybridized with the complementary DNA (T9). The hybrid showed a very sharp melting curve with Tm = 34 °C.
Preparation and Characterization of Lithium Ion Conducting Glass–Polymer Composites
Authors: Hayashi Akitoshi , Kitade Taku , Ikeda Yuko , Kohjiya Shinzo , Matsuda Atsunori , Tatsumisago Masahiro , Minami Tsutomu 
Published: March 2003

Abstract
Glass–polymer composite electrolytes of high lithium ion conducting oxysulfide glass and the comb-shaped poly(oxyethylene) polymer (TEC-19) were prepared. The conductivity of the composite with 2 vol% TEC-19 doped with LiClO4 was 1 × 10−3 at 100 °C and 3 × 10−5 S cm−1 at 30 °C. The composite exhibited a 4 V stable potential window versus Li+/Li.
Novel 1,2-Dilithiodisilanes Derived from Reduction of Stable Tetrakis(trialkylsilyl)disilenes with Lithium Metal
Authors: Kira Mitsuo , Iwamoto Takeaki , Yin Dongzhu , Maruyama Toyotaro , Sakurai Hideki 
Published: March 2003

Abstract
1,2-Dilithiotetrakis(trialkylsilyl)disilanes [(R3Si)2SiLi]2 (R3Si = t-BuMe2Si and i-Pr2MeSi) were prepared as stable off-white powder by the reduction of the corresponding tetrakis(trialkylsilyl)disilenes with lithium in THF. The 1,2-dilithiodisilanes reacted with water, iodomethane, and chlorosilanes to give the corresponding disubstituted products in high yields.
Visible Light-Induced Degradation of Methylene Blue on S-doped TiO2
Authors: Umebayashi Tsutomu , Yamaki Tetsuya , Tanaka Sigeru , Asai Keisuke 
Published: March 2003

Abstract
A sulfur (S)-doped titanium dioxide (TiO2) photocatalyst was synthesized by oxidative annealing of titanium disulfide (TiS2). TiS2 turned into anatase TiO2 when annealed in air. The residual S atoms occupied O-atom sites in the TiO2 to form Ti–S bonds. The S doping caused the absorption edge of TiO2 to be shifted into the lower energy region. Consequently, methylene blue adsorbed on the S-doped TiO2 was photocatalytically decomposed by visible light irradiation.
The relationship of mental illness to targeted contact behavior toward state government agencies and officials
Authors: Scalora Mario J. , Baumgartner Jerome V. , Plank Gary L. 
Published: March 2003

AbstractResearch in the burgeoning field of threat assessment has illuminated the importance of mental illness factors when considering risk of targeted violence—particularly related to government agencies and officials. The authors analyzed 127 cases investigated by a state law enforcement agency regarding threatening or other contacts toward public officials or state agency employees prompting security intervention. Univariate and discriminant analysis indicated that mentally ill subjects were significantly more likely to engage in more contacts as well as to make specific demands during such contacts. Mentally ill subjects were also more likely to articulate help‐seeking concerns and employ religious themes, as opposed to using insulting, degrading, or ominous language toward the target or issuing complaints regarding policy issues. Contrary to other research, the mentally ill subjects within this sample were not significantly more likely to engage in approach behavior, a threshold for higher risk of violence. Implications for threat assessment activity are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Formation, Structure and Reactivity of Boryloxycarbyne Complexes of Group 6 Metals
Authors: Braunschweig Holger , Klinkhammer Karl W. , Koster Margot , Radacki Krzysztof 
Published: March 2003

AbstractReaction of the diborane(4) B2(NMe2)2I2 with two equivalents of K[(η5‐C5H5)M(CO)3] (M=Cr, Mo, W) yielded the dinuclear boryloxycarbyne complexes [{(η5‐C5H5)(OC)2MCO}2B2(NMe2)2] (4 a, M=Mo; b, M=W; c, M=Cr), which were fully characterised in solution by multinuclear NMR methods. The Mo and W complexes 4 a, b proved to be kinetically favoured products of this reaction and underwent quantitative rearrangement in solution to afford the complexes [{(η5‐C5H5)(OC)2MCO}B(NMe2)B(NMe2){M(CO)3(η5‐C5H5)}] (5 a, M=Mo; b, M=W); 5 a was characterised by X‐ray crystallography in the solid state. Corresponding reactions of B2(NMe2)2I2 with only one equivalent of K[(η5‐C5H5)M(CO)3] (M=Mo, W) initially afforded 1:1 mixtures of the boryloxycarbyne complexes 4 a, b and unconsumed B2(NMe2)2I2. This mixture, however, yielded finally the diborane(4)yl complexes [(η5‐C5H5)(OC)3M{B(NMe2)B(NMe2)I}] (6 a, M=Mo; b, M=W) by [(η5‐C5H5)(OC)3M] transfer and rearrangement. Density functional calculations were carried out for 4 c and 5 a, b.
Novel 4,4′‐Bipyridinium‐Based Cationic Mono‐ and Bicyclic Cyclophanes
Authors: Rajakumar Perumal , Srinivasan Kannupal 
Published: March 2003

AbstractThe intra‐annularly functionalised tetracationic cyclophanes 3a−b were synthesised from the corresponding m‐terphenyl dibromides and 4,4′‐bipyridine by a simple quaternisation methodology. An intra‐annularly linked tetracationic cyclophane 10 was synthesised in three steps and it possesses a concave structure and novel intramolecular CT interactions. Synthesis of the tetracationic cyclophanes 13, 16a and 16b containing carbonyl groups was accomplished from the corresponding carbonyl dibromides and 4,4′‐bipyridine. Sixfold coupling of a tricarbonyl tribromide with 4,4′‐bipyridine afforded a rare hexacationic cyclophane 18. The cyclophanes 3a and 3c form CT complexes with a bis(1H‐indol‐3‐yl)(phenyl)methane compound while the cyclophane 13 forms CT complexes with 1,4‐dimethoxybenzene and indole. Electrochemical parameters were obtained for all the cyclophanes. They exhibit two sets of redox peaks and most of them are quasireversible. The smallest‐cavity cyclophane 13 has the lowest reduction potentials in the series. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Carboxyl‐Tethered Symmetric Conjugated Polyenes as Fluorescent Transmembrane Probes of Lipid Bilayers
Authors: Quesada Ernesto , Acuña A. Ulises , Amat‐Guerri Francisco 
Published: March 2003

AbstractThe synthesis of a new series of fluorescent transmembrane probes in which two hydrophilic methyl ester or carboxyl groups are connected by a polymethylene chain, with four, five or six conjugated double bonds in a central position, is reported. The length of the linear structures was designed to match the width of typical lipid bilayers. These bolaamphiphilic compounds result, with overall yields higher than 80%, from an easy PdII‐catalyzed double cross‐coupling between terminal acetylene esters and conjugated 1,ψ‐dihalopolyenes, followed by selective triple bond partial reduction with activated zinc, and iodine isomerization to the all‐(E) isomer. An alternative approach, based on a Stille double cross‐coupling between the appropriate all‐(E)‐ψ‐halopolyenes and (E)‐bis(tributylstannyl)ethene, yielded mixtures that could not be resolved by standard chromatographic methods due to the presence of other simultaneous coupling reactions, which are also discussed in detail. Nevertheless, the Stille method can be of utility for the obtention of carbonyl‐polyene conjugated analogs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Solid‐State Structural Study of the Charge‐Transfer Complexes of 5,7,9‐Trimethyl‐ and 2,11,20‐Trithia[33](1,3,5)cyclophanes
Authors: Yasutake Mikio , Araki Koji , Zhou Ming , Nogita Rika , Shinmyozu Teruo 
Published: March 2003

Abstract5,7,9‐Trimethyl[33](1,3,5)cyclophane (1), with two binding sites of different donating ability, adopts aC3conformation both in the solid state (−170 °C) and in CD2Cl2solution at −90 °C. 5,7,9‐Trimethyl[33](1,3,5)cyclophane‐2,11,20‐trione (9) has the sameC3symmetry, while [33](1,3,5)cyclophane‐2,11,20‐trione (12) adopts theCsstructure in the solid state (−170 °C). The structures of1and9are the first examples of C3orC3hsymmetries in the [33](1,3,5)cyclophanes; their preferred conformers areCsboth in solution and in the solid state. The cyclophane1shows much stronger donating ability than the parent [33](1,3,5)cyclophane (2). In the TCNQ‐F4(1:1) complex of1, the donor (D) and the acceptor (A) are stacked alternately, with partial and complete D‐A overlaps being observed in the solid state (−170 °C) in the forms of partial D‐A overlap of the methyl‐substituted benzene face and TCNQ‐F4and of nearly complete D‐A overlap of the methyl‐unsubstituted benzene face and TCNQ‐F4. The former type of overlap is generally observed in the TCNQ‐F4complexes of the [3n]cyclophanes, and the transannular D‐A distance (3.22 Å) is much shorter than that in the latter (3.58 Å). This supports the idea that the methyl‐substituted benzene ring interacts more strongly than the methyl‐unsubstituted benzene ring with the acceptor. Consistently with this, two types of acceptor columns are observed, and the transannular distances between acceptors are 3.45 Å for the methyl‐unsubstituted side and 3.26 Å for the methyl‐substituted side. In the 2,11,20‐trithia[33](1,3,5)cyclophane (4)‐TCNQ‐F4(1:1) complex, an alternating D‐A stacking similar to that in [33](1,3,5)cyclophane (2)‐TCNQ‐F4(1:1) is observed. The acceptors are stacked in a parallel fashion and form an infinite column, the A−A distance in the (4)‐TCNQ‐F4(1:1) complex being 3.10 Å, and the acceptors in the unit cell are arranged parallel in a plane, the A‐A distance being 3.12 Å. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Phosphopeptide detection and sequencing by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight tandem mass spectrometry
Authors: Bennett Keiryn L. , Stensballe Allan , Podtelejnikov Alexandre V. , Moniatte Marc , Jensen Ole Nørregaard 
Published: March 2003

AbstractA prototype matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight (MALDI‐QqTOF) tandem mass spectrometer was used to sequence a series of phosphotyrosine‐, phosphothreonine‐ and phosphoserine‐containing peptides. The high mass resolution and mass accuracy of the instrument allowed the localization of one, three or four phosphorylated amino acid residues in phosphopeptides up to 3.1 kDa.Tandem mass spectra of two different phosphotyrosine peptides permitted amino acid sequence determination and localization of one and three phosphorylation sites, respectively. The phosphotyrosine immonium ion at m/z 216.04 was observed in these MALDI low‐energy CID tandem mass spectra. Elimination of phosphate groups was evident from the triphosphorylated peptide but not from the monophosphorylated species. The main fragmentation pathway for the synthetic phosphothreonine‐containing peptide and for phosphoserine‐containing peptides derived from β‐casein and ovalbumin was the β‐elimination of phosphoric acid with concomitant conversion of phosphoserine to dehydroalanine and phosphothreonine to 2‐aminodehydrobutyric acid. Peptide fragment ions of the b‐ and y‐type allowed, in all cases, the localization of phosphorylation sites. Ion signals corresponding to (‐17), (‐18) and (‐17) fragment ions were also observed. The abundant neutral loss of phosphoric acid (−98 Da) is useful for femtomole level detection of phosphoserine‐peptides in crude peptide mixtures generated by gel in situ digestion of phosphoproteins. Copyright © 2001 John Wiley & Sons, Ltd.
Genetic background determines phenotypic severity of the Plp rumpshaker mutation
Authors: Al‐Saktawi K. , McLaughlin M. , Klugmann M. , Schneider A. , Barrie J.A. , McCulloch M.C. , Montague P. , Kirkham D. , Nave K.‐A. , Griffiths I.R. 
Published: March 2003

AbstractThe rumpshaker mutation of the proteolipid protein (Plp) gene causes dysmyelination in man and mouse. We show that the phenotype in the mouse depends critically on the genetic background in which the mutation is expressed. On the C3H background there is normal longevity whereas changing to a C57BL/6 strain results in seizures and death at around postnatal day 30. The more severe phenotype is associated with less myelin and reduced levels of major myelin proteins. There are also more apoptotic cells, including oligodendrocytes, increased numbers of proliferating cells, increased numbers of NG2+ oligodendrocyte progenitors and increased microglia compared to the milder phenotype. The number of mature oligodendrocytes is similar to wild‐type in both strains of mutant, however, suggesting that increased oligodendrocyte death is matched by increased generation from progenitors. The dichotomy of phenotype probably reflects the influence of modifying loci. The localization of these putative modifying genes and their mode of action remain to be determined. © 2003 Wiley‐Liss, Inc.
Viscoelasticity in Polymer Films on Rigid Substrates
Authors: Krupička Andreas , Johansson Mats , Hult Anders 
Published: March 2003

AbstractThe viscoelasticity of two thermally crosslinked polymer coatings was examined in terms of relaxation of the applied stress after a sudden strain. Two different transient methods were utilized: flat‐ended cylindrical indentation testing of a polymer film on a rigid substrate and tensile testing of a corresponding free‐standing polymer film. The correlation between tensile and indentation tests was studied. The mechanical response of a viscoelastic layer deposited on a rigid substrate was investigated as a function of indentation depth. There was good agreement between the results of the tensile and indentation tests for thick film layers at moderate indentation depths. The findings indicate that the substrate influences the coating performance by reducing the viscous contribution to the stress response and amplifying the magnitude of the equilibrium modulus for large indentation depths. The indentation method utilized here was shown to be a potentially suitable tool for the determination of Poisson's ratio of polymer films.
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Temperature‐Responsive Graft Copolymers with Poly(propylene glycol) Side Chains
Authors: Maeda Yasushi , Tsubota Miki , Ikeda Isao 
Published: March 2003

AbstractThe phase behavior of graft copolymers in aqueous solution was investigated. The graft copolymers consist of poly(propylene glycol) (PPG) side chains and N,N‐dimethylacrylamide (dMA), N‐vinylimidazole (VIm), and N‐isopropylacrylamide (iPA), respectively, as backbones. Phase transition temperatures of the PPG copolymers increased with increasing the content of dMA and iPA as relatively more hydrophilic comonomers and with an increase in the degree of ionization of the incorporated VIm units.Chemical structure of the graft copolymersmagnified imageChemical structure of the graft copolymers
Influence of Alkylaluminium Activators and Mixtures thereof on Ethylene Polymerization with a Tridentate Bis(imino)pyridinyliron Complex
Authors: Radhakrishnan Karunakaran , Cramail Henri , Deffieux Alain , François Philippe , Momtaz Ardéchir 
Published: March 2003

AbstractThe effect of various alkylaluminium compounds and their mixtures on ethylene polymerization catalyzed with a tridentate bis(imino)pyridinyliron catalyst is studied. Triethylaluminium and trihexylaluminium are good cocatalysts but yield polyethylenes with broad molar mass distribution (MMD) whereas triisobutylaluminium, a less efficient activator, gives polyethylenes with unimodal and narrow MMD. Specific mixtures of branched and linear alkylaluminium compounds yield highly active catalytic systems and polyethylenes with unimodal and tunable MMD.SEC traces of PE prepared with iron catalyst and (1) TEA, (2) TiBA, and (3) THA (Al/Fe = 250) as cocatalysts.magnified imageSEC traces of PE prepared with iron catalyst and (1) TEA, (2) TiBA, and (3) THA (Al/Fe = 250) as cocatalysts.
Thermal, morphology, and NMR characterizations on phase behavior and miscibility in blends of isotactic polystyrene with poly(cyclohexyl methacrylate)
Authors: Chang Li Ling , Woo E. M. 
Published: March 2003

AbstractThe miscibility and phase behavior in a binary blend of isotactic polystyrene (iPS) and poly(cyclohexyl methacrylate) (PCHMA) were investigated by differential scanning calorimetry, optical microscopy (OM), and solid‐state 13C cross‐polarity/magic‐angle spinning NMR. The iPS/PCHMA blend was miscible when all compositions showed a single composition‐dependent glass‐transition temperature (Tg) and when the blend went through a thermodynamic phase transition upon heating to above the lower critical solution temperature as determined by OM measurements. The 1H NMR spin‐relaxation times in the laboratory frame (T) and in the rotating frame (T) for iPS/PCHMA blends with various compositions and neat components were directly measured through solid‐state13C NMR. The results of T indicated that the blends are homogeneous, at least on a scale of 75–85 nm, confirming the miscibility of the system. The single decay and composition‐dependent T values for each blend further demonstrated the blends are homogeneous on a scale of 2.5–3.5 nm. The results suggested that iPS and PCHMA are intimately mixed at the molecular level within the blends at all compositions. The tacticity of polystyrene does not seem to adversely influence the miscibility in blends of iPS/PCHMA. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 772–784, 2003
Silicic Acid Polymerization Catalyzed by Amines and Polyamines
Authors: Mizutani Tadashi , Nagase Hisato , Ogoshi Hisanobu 
Published: March 2003

Abstract
Polymerization and subsequent gelation of silicic acid in water were catalyzed by amines and polyamines. Particularly effective were poly(allylamine), poly(lysine), and poly(arginine), which promoted spontaneous gelation. The resultant silica gel contained a sizable portion of amines, which altered the surface properties of silica gel.
Total Synthesis of Antibiotic, Micrococcin P, from 2,3,6-Polythiazolesubstituted Pyridine Skeleton [Fragment A-C]
Authors: Shin Chung-gi , Okumura Kazuo , Shigekuni Masashi , Nakamura Yutaka 
Published: March 2003

Abstract
Total synthesis of an antibiotic, micrococcin P, was first accomplished by the coupling of a 2,3,6-polythiazole-substituted pyridine skeleton [Fragment A-C] with the independently synthesized Fragments B and D, and then deprotection with trifluoroacetic acid and final intramolecular cyclization using BOP as condensing agent.