bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective role of melatonin in domoic acid‐induced neuronal damage in the hippocampus of adult rats
Authors: Ananth C. , Gopalakrishnakone P. , Kaur C. 
Published: March 2003

AbstractDomoic acid (DA), a kainite‐receptor agonist and potent inducer of neurotoxicity, has been administered intravenously in adult rats in the present study (0.75 mg/kg body weight) to demonstrate neuronal degeneration followed by glial activation and their involvement with inducible nitric oxide synthase (iNOS) in the hippocampus. An equal volume of normal saline was administered in control rats. The pineal hormone melatonin, which protects the neurons efficiently against excitotoxicity mediated by sensitive glutamate receptor, was administered intraperitoneally (10 mg/kg body weight), 20 min before, immediately after, and 1 h and 2 h after the DA administration, to demonstrate its role in therapeutic strategy. Histopathological analysis (Nissl staining) demonstrated extensive neuronal damage in the pyramidal neurons of CA1, CA3 subfields and hilus of the dentate gyrus (DG) in the hippocampus at 5 days after DA administration. Sparsely distributed glial fibrillary acidic protein (GFAP)‐immunoreactive astrocytes were observed in the hippocampus at 4–24 h after DA administration and in the control rats. Astrogliosis was evidenced by increased GFAP immunoreactivity in the areas of severe neuronal degeneration at 5 days after DA administration. Along with this, microglial cells exhibited an intense immunoreaction with OX‐42, indicating upregulation of complement type 3 receptors (CR3). Ultrastructural study revealed swollen or shrunken degenerating neurons in the CA1, CA3 subfields and hilus of the DG and hypertrophied astrocytes showing accumulation of intermediate filament bundles in the cytoplasm were observed after administration of DA. Although no significant change could be observed in the mRNA level of iNOS expression between the DA‐treated rats and controls at 4–24 h and at 5‐day time intervals, double immunofluorescense revealed co‐expression of induced iNOS with GFAP immunoreactive astrocytes, but not in the microglial cells, and iNOS expression in the neurons of the hippocampal subfields at 5 days after DA administration. Expression of iNOS was not observed in the hippocampus of control rats. DA‐induced neuronal death, glial activation, and iNOS protein expression were attenuated significantly by melatonin treatment and were comparable to the control groups. The results of the present study suggest that melatonin holds potential for the treatment of pathologies associated with DA‐induced brain damage. It is speculated that astrogliosis and induction of iNOS protein expression in the neurons and astrocytes of the hippocampus may be in response to DA‐induced neuronal degeneration. Hippocampus 2003;13:375–387. © 2003 Wiley‐Liss, Inc.
Multiple hypothalamic sites control the frequency of hippocampal theta rhythm
Authors: Woodnorth Mary‐Anne , Kyd Rachel J. , Logan Barbara J. , Long Mark A. , McNaughton Neil 
Published: March 2003

AbstractStimulation of a neural pathway originating in the brainstem reticular formation, with synapses in the medial hypothalamus, activates the hippocampal theta rhythm. The frequency of reticular‐elicited theta is determined in the medial supramammillary nucleus (mSuM) completely in anaesthetised rats, but only partially when the animal is awake. We tested other medial hypothalamic sites for their capacity to control theta frequency in awake rats. Blockade of sodium channels (1 μl fast infusion of the local anaesthetic procaine, experiment 1) or increased inhibition by GABA (Chlordiazepoxide [CDP], experiment 2) was found to reduce or increase the frequency of reticular‐elicited theta, depending on the precise site of injection, in the region of the dorsomedial hypothalamic nucleus (DMH) and the posterior hypothalamic nucleus (PH). A band of null sites for CDP was located in the region of the ventral border of PH and dorsal border of mSuM. Using 0.5 and 1 μl CDP, and slow infusions (experiment 3), it was found that effective PH sites were also separate from mSuM in the rostrocaudal direction. In experiment 4, the DMH/PH region was mapped with unilateral and bilateral slow infusions of 0.5 μl CDP. CDP significantly reduced frequency in medial (periventricular) and dorsal PH, but not DMH. Bilateral injections appeared to generally sum the usual effects of unilateral injection, producing effects of intermediate size. However, the absolute frequency change in any given site, or with any pair of sites, did not exceed 1 Hz, which is similar to what is seen with single injections in mSuM. Overall, it appears that at, any one time, theta frequency may be determined by a complex interplay between distinct but interacting modulatory regions in the medial hypothalamus. Hippocampus 2003;13:361–374. © 2003 Wiley‐Liss, Inc.
Improving hydrogen/deuterium exchange mass spectrometry by reduction of the back‐exchange effect
Authors: Kipping Marc , Schierhorn Angelika 
Published: March 2003

AbstractThe measurement of deuterium incorporation kinetics using hydrogen/deuterium (H/D) exchange experiments is a valuable tool for the investigation of the conformational dynamics of biomolecules in solution. Experiments consist of two parts when using H/D exchange mass spectrometry to analyse the deuterium incorporation. After deuterium incorporation at high D2O concentration, it is necessary to decrease the D2O concentration before the mass analysis to avoid deuterium incorporation under artificial conditions of mass spectrometric preparation and measurement. A low D2O concentration, however, leads to back‐exchange of incorporated deuterons during mass analysis. This back‐exchange is one of the major problems in H/D exchange mass spectrometry and must be reduced as much as possible. In the past, techniques using electrospray ionization (ESI) had the lowest back‐exchange values possible in H/D exchange mass spectrometry. Methods for the measurement of H/D exchange by matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) that have been developed since 1998 have some significant advantages, but they could not achieve the back‐exchange minima of ESI methods. Here, we present a protocol for H/D exchange MALDI‐MS which allows for greater minimization of back‐exchange compared with H/D exchange ESI‐MS under similar conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Macromolecular assembly of Helicobacter pylori urease investigated by mass spectrometry
Authors: Pinkse Martijn W. H. , Maier Claudia S. , Kim Jung‐In , Oh Byung‐Ha , Heck Albert J. R. 
Published: March 2003

AbstractThe supramolecular assembly of Helicobacter pylori urease was studied by nanoflow electrospray ionization orthogonal time‐of‐flight mass spectrometry. The measured molecular mass of the urease complex of 1.06 MDa corresponds to a dodecameric (αβ)12 assembly of urease α (26 kDa) and β (61 kDa) subunits. The dodecamer disassembles readily into (αβ)3 subunits in solution and under controlled collisional‐induced dissociation in the gas phase. This is in strong support of an ((αβ)3)4 architecture consistent with the recently published x‐ray structure. In vitro, the α and β subunits are capable of re‐assembling to (αβ)3, but not further to the dodecameric complex. Copyright © 2003 John Wiley & Sons, Ltd.
Contributions of mass spectrometry in the study of nucleic acid‐binding proteins and of nucleic acid–protein interactions
Authors: Rusconi Filippo , Guillonneau François , Praseuth Danièle 
Published: March 2003

Abstract

I.
Introduction
306

II.
Supramolecular Structure Characterization
308

A. A Protein Is Used as a “Hook”
309

1. Immuno‐Precipitation
309

2. Tagging with a Poly‐Histidine Sequence
310

3. Direct Analysis of Large Protein Complexes
311

4. Tandem Affinity Purification Tag Procedure
312

B. A Nucleic Acid Is Used as a “Hook” or as a “Tracking Label”
314

1. Purification of a Nucleic Acid–Protein Complex in Solution
316

2. Preparative Electrophoretic Mobility Shift Assay
317

3. Surface‐Enhanced Laser Desorption/Ionization
317

4. Surface Plasmon Resonance
319

5. Probing Nucleic Acid–Protein Interactions on Membranes
320

III.
Supramolecular Analysis in the Gas Phase
321

IV.
Molecular Structure Characterization
324

A. Determination of the Assembly Topology
324

1. Non Site‐Directed Cross‐Links
326

2. Native‐State Chemistry
330

3. Site‐Directed Cross‐Links
332

B. Regulation of the Complex's Structure and Function
334

1. Protein Phosphorylation
334

2. Modification of the Basic Residues
336

3. Oxidoreduction Balance‐Related Modifications
337

V.
Concluding Remarks
339

A. Factual Contributions
339

B. Perspectives
340

Acknowledgments
341

Abbreviations
341

References
341

Nucleic acid–protein (NA–P) interactions play essential roles in a variety of biological processes—gene expression regulation, DNA repair, chromatin structure regulation, transcription regulation, RNA processing, and translation—to cite only a few. Such biological processes involve a broad spectrum of NA–P interactions as well as protein–protein (P–P) interactions. These interactions are dynamic, in terms of the chemical composition of the complexes involved and in terms of their mere existence, which may be restricted to a given cell‐cycle phase. In this review, the contributions of mass spectrometry (MS) to the deciphering of these intricate networked interactions are described along with the numerous applications in which it has proven useful. Such applications include, for example, the identification of the partners involved in NA–P or P–P complexes, the identification of post‐translational modifications that (may) regulate such complexes' activities, or even the precise molecular mapping of the interaction sites in the NA–P complex. From a biological standpoint, we felt that it was worth the reader's time to be as informative as possible about the functional significance of the analytical methods reviewed herein. From a technical standpoint, because mass spectrometry without proper sample preparation would serve no purpose, each application described in this review is detailed by duly emphasizing the sample preparation—whenever this step is considered innovative—that led to significant analytical achievements. © 2003 Wiley Periodicals, Inc., Mass Spec Rev 21:305–348, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.10036
Block factorized preconditioners for high‐order accurate in time approximation of the Navier‐Stokes equations
Authors: Veneziani Alessandro 
Published: March 2003

AbstractComputationally efficient solution methods for the unsteady Navier‐Stokes incompressible equations are mandatory in real applications of fluid dynamics. A typical strategy to reduce the computational cost is to split the original problem into subproblems involving the separate computation of velocity and pressure. The splitting can be carried out either at a differential level, like in the Chorin‐Temam scheme, or in an algebraic fashion, like in the algebraic reinterpretation of the Chorin‐Temam method, or in the Yosida scheme (see 1 and 19). These fractional step schemes indeed provide effective methods of solution when dealing with first order accurate time discretizations. Their extension to high order time discretization schemes is not trivial. To this end, in the present work we focus our attention on the adoption of inexact algebraic factorizations as preconditioners of the original problem. We investigate their properties and show that some particular choices of the approximate factorization lead to very effective schemes. In particular, we prove that performing a small number of preconditioned iterations is enough to obtain a time accurate solution, irrespective of the dimension of the system at hand. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 487–510, 2003
Stability of polyaniline in air and acidic water
Authors: Hobaica Stephen C. 
Published: March 2003

AbstractPolyaniline is a member of the class of electrically conducting polymers, having possible commercial applications such as coatings. Aqueous‐based polyaniline coatings are preferred over organic solvent or concentrated strong acid based coatings because water is not a pollutant. The overall goal of this study was to further the development of water‐based polyaniline coatings by an examination of the effect of acidic water (pH 1.18) and air on polyaniline. Knowledge of the effect of water on the structure, molecular weight, electrical conductivity, and diffusion of the dopant assisted in ascertaining whether polyaniline degraded with water exposure. Knowledge of how Fourier transform infrared (FTIR) spectra would be affected by dry air was important for determining if polyaniline was chemically stable with time. The results showed that the molecular weight, ultraviolet–visible and FTIR spectra, and carbon‐to‐nitrogen molar ratio in the polymer backbone all remained unchanged during acidic water immersion. The constant nature of these physical parameters showed a high degree of water stability. A chloride ion diffusion coefficient of 2.8 to 85 × 10−9 cm2/h, the chloride concentration, and the electrical conductivity were also measured with the water immersion time. Aging polyaniline powders in a desiccator for 5 years showed no effect on the molecular structure, as indicated by the FTIR spectrum. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 807–822, 2003
Prenatal Sonographic Diagnosis of Klippel-Trenaunay-Weber Syndrome Associated with Umbilical Cord Hemangioma
Authors: Sahinoglu Zeki , Uludogan Mehmet , Delikara Nuri M. 
Published: March 2003

AbstractKlippel-Trenaunay-Weber syndrome (KTW), also known as angio-osteohypertrophy syndrome, is a complex developmental disorder characterized by asymmetric hemi-hypertrophy of limbs and trunk due to bony and soft tissue overgrowth that may extend across the midline, varicose veins, and cutaneous hemangiomata. This rare syndrome has been previously described in the prenatal period by ultrasonography, and in literature, there are quite different presentation of cases. We describe a case suggested as a KTW syndrome by prenatal ultrasonography. The sonographic appearance of an unilateral leg hypertrophy associated with irregular echolucent cystic areas was consistent with KTW syndrome. A spheric, weak-echogenic mass without any active blood flow located in the umbilical cord revealed by color Doppler ultrasonography was an unexpected finding. The postpartum examination confirmed the prenatal diagnosis.
Stoichiometric Decomposition of Pure Water over Pt-Loaded Ti/B Binary Oxide under UV-Irradiation
Authors: Moon Sang-Chul , Mametsuka Hiroaki , Suzuki Eiji , Anpo Masakazu 
Published: March 2003

Abstract
A titanium-boron binary oxide has been prepared by the sol-gel method and used as a photocatalyst for the decomposition of water. The structure of titanium oxide species in the Ti/B binary oxide was amorphous before and crystal after calcination in O2, while the boron oxide species retained its amorphous state. Pt-loaded Ti/B photocatalysts were found to decompose water stoichiometrically in aqueous suspension systems. Their photocatalytic activities decreased markedly with increase in the calcination temperature, indicating that the photocatalytic activity of the Ti/B binary oxide was strongly dependent on the crystal phase of the titanium oxide.
New Lithium Ion Conductor Li3InBr6 Studied by 7Li NMR
Authors: Tomita Yasumasa , Fuji-i Aya , Ohki Hiroshi , Yamada Koji , Okuda Tsutomu 
Published: March 2003

Abstract
Super ionic conductor Li3InBr6 (σ=10−3Scm−1 at 297 K) due to lithium ions was synthesized and characterized by temperature dependence of the 7Li NMR T1. The substitution effect of the cation and the temperature behavior of T1 suggested that the high ionic conductivity resulted from the considerably disordered state of the cationic sublattice.
Cell-expansion of Tris(2,4-pentanedionato)chromium and -aluminum under Light Irradiation
Authors: Okumura Toshihiko , Ikagawa Takashi , Otsuka Takuhiro , Kaizu Youkoh 
Published: March 2003

Abstract
In the previous letter,1 we have reported on the cell-expansion and contraction of platinum(II) complexes under light irradiation and discussed the results in the term of the molecular structures in the excited states. For tris(2,4-pentanedionato)chromium and -aluminum(abbreviated as Cr(acac)3 and Al(acac)3, respectively), we also found the cell-expansion under light irradiation. The X-ray powder patterns of these complexes were shifted to low reflect-angle than original one by light absorption of the complexes. The shift of X-ray powder pattern of Al(acac)3 is due to thermal cell-expansion caused by internal conversion of the molecule under light irradiation. In case of Cr(acac)3, however, the shifts are due to not only the thermal cell-expansion but also another reason concerned with the structures in the excited states.
Preparation of New Carbosilane Dendrimers Carrying Mesogenic Groups
Authors: Terunuma Daiyo , Kato Tomonori , Nishio Rei , Matsuoka Koji , Kuzuhara Hiroyoshi , Aoki Yoshio , Nohira Hiroyuki 
Published: March 2003

Abstract
A series of new carbosilane dendrimers was prepared by repeating a combination of hydrosilation and allylation on a core molecule, triallylphenylsilane. Subsequent hydroboration and oxidation of the dendrimers gave the polyol derivatives, which were treated with a mesogenic molecule, 6-(4-cyanobiphenyl-4′-oxy) hexanoyl chloride, to give new carbosilane dendrimers carrying mesogenic groups. It was found that the all carbosilane dendrimers exhibited liquid crystal phases. The effects of the dendrimer generations on the ranges of liquid crystal temperature were investigated.
Silole-Acetylene π-Electronic Systems with Low Bandgaps: Synthesis, Structure, and UV-vis Absorption Spectra of 2,5-Diethynylsiloles Derivatives and Their Polymers
Authors: Yamaguchi Shigehiro , Iimura Kazuo , Tamao Kohei 
Published: March 2003

Abstract
A series of 2,5-diethynylsilole derivatives and their polymers, prepared by the Stille coupling reaction, show unique optical properties such as long-wavelength absorptions in their UV-vis absorption spectra.
Synthesis and Structure of a Series of Oligo[1,1-(2,3,4,5-tetramethylsilole)]s
Authors: Kanno Ken-ichiro , Ichinohe Masaaki , Kabuto Chizuko , Kira Mitsuo 
Published: March 2003

Abstract
A series of oligo(1,1-silole)s, Me3Si[SiC4Me4]n SiMe3 (3: n=3, 4:n=4, 5:n=5) were synthesized and characterized. X-ray diffraction analysis of tersilole 3 revealed that the pentasilane backbone has almost all-trans conformation. The oligo(1,1-silole)s show distinct UV absorptions due to σ-σ*, σ-π*, and π-π* transitions.
1,3-Bis[5-(dimesitylboryl)thiophen-2-yl]benzene and 1,3,5-Tris[5-(dimesitylboryl)thiophen-2-yl]benzene as a Novel Family of Electron-Transporting Hole Blockers for Organic Electroluminescent Devices
Authors: Kinoshita Motoi , Shirota Yasuhiko 
Published: March 2003

Abstract
A novel family of electron-transporting hole blockers, 1,3-bis[5-(dimesitylboryl)thiophen-2-yl]benzene and 1,3,5-tris[5-(dimesitylboryl)thiophen-2-yl]benzene (TMB-TB), were designed and synthesized. They were found to exhibit multiple redox behavior in electrochemical reduction and to readily form stable amorphous glasses with high glass-transition temperatures above 100 °C. TMB-TB was proven to function well as a hole blocker in blue-emitting organic electroluminescent devices.
[2+2]-Cycloaddition Reaction of Styrene Derivatives Using an Fe(III) Salt Catalyst
Authors: Ohara Hiroyuki , Itoh Toshiyuki , Nakamura Masaharu , Nakamura Eiichi 
Published: March 2003

Abstract
Iron(III) perchlorate catalyzed cyclodimerization of trans-anethole gave trans,anti,trans-cyclobutane stereospecifically in good yield. Alumina supported iron(III) perchlorate was an especially efficient one-electron oxidation reagent.
Intercalation of Metalloporphyrin-Surfactant Complex into Layered Niobate and the Photochemical Injection of Electrons to Niobate
Authors: Yamaguchi Yorihisa , Yui Tatsuto , Takagi Shinsuke , Shimada Tetsuya , Inoue Haruo 
Published: March 2003

Abstract
An anionic metalloporphyrin (Zn(II)TCPP4−) was successfully co-intercalated into the layered oxide K4Nb6O17 with cationic surfactant (CTAB). Photochemical injection of electrons into the niobate layer was observed.
Fabrication of Polymer Particle Monolayer onto Alkylated Glass Plates
Authors: Yamaguchi Keizo , Taniguchi Tatsuo , Kawaguchi Seigou , Nagai Katsutoshi 
Published: March 2003

Abstract
Polymer particle monolayer was fabricated onto alkylated glass plates. The concentration of sodium chloride and cetyltrimethylammonium bromide (CTAB) was found to play a key role in control of the morphology and coverage of the monolayer on the alkylated glass plates.
New Synthetic Method of Benzaldehydes and α,β-Unsaturated Aldehydes with I2 under Photoirradiation
Authors: Itoh Akichika , Kodama Tomohiro , Masaki Yukio 
Published: March 2003

Abstract
Benzylic alcohols and allylic alcohols were found to be oxidized to the corresponding benzaldehydes and α,β-unsaturated aldehydes easily in the presence of I2 under photoirradiation.
High Lithium Ion Conductivity of Glass–Ceramics Derived from Mechanically Milled Glassy Powders
Authors: Hayashi Akitoshi , Hama Shigenori , Morimoto Hideyuki , Tatsumisago Masahiro , Minami Tsutomu 
Published: March 2003

Abstract
Crystallization of the 80Li2S·20P2S5 (mol%) glassy powders derived from mechanical milling improved their conductivities. The obtained glass–ceramic exhibited high conductivity of approximately 10−3 S cm−1 at room temperature. The stabilization of the high-temperature phase of Li7PS6 crystal in the glass matrix brought about those high conductivities.
Photo-Induced Long-Lived Intramolecular Electron Transfer in a Co Valence Tautomeric Complex
Authors: Sato Osamu , Hayami Shinya , Gu Zhong-ze , Seki Kanako , Nakajima Rie , Fujishima Akira 
Published: March 2003

Abstract
A photo-induced valence tautomerism was observed in a Co complex, [CoIII-LS(phen)(3,5-DBSQ)(3,5-DBCat)]. In this system, visible light illumination induces an electron transfer from 3,5-DBCat to CoIII-LS, producing [CoII-HS(phen)(3,5-DBSQ)2]. The resultant photo-induced metastable state could be trapped more than 1 h at 5 K.
Observation of Highly Ordered 3 × 4 Phase of Ethanethiol Self-Assembled Monolayer on Au(111)
Authors: Kawasaki Mitsuo , Nagayama Hiromichi 
Published: March 2003

Abstract
A novel observation of a highly ordered self-assembled monolayer of ethanethiol (a very short-chain alkanethiol) on Au(111) is reported. A good structural perfection of the monolayer allowed a surprisingly high-resolution STM imaging clearly uncovering the unique 3 × 4 unit cell and the detailed atomic arrangement therein. Along with the infrared reflection absorption spectrum of the monolayer the results indicate that the interchain interactions involving such short alkyl chains can still play a dominant role in controlling the overall monolayer structure.