bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ Synthesis and Characterization of Spherical CdS/Polyacrylamide Nanocomposites by γ-Irradiation in W/O Microemulsions
Authors: Ni Yonghong , Ge Xuewu , Liu Huarong , Zhang Zhicheng , Ye Qiang
Published: March 2003

Spherical CdS/polyacrylamide (CdS–PAM) nanocomposites were successfully synthesized in single step by γ-irradiation in a W/O microemulsion under ambient pressure at room temperature. The final product was characterized by various means such as XRD, IR, UV–vis, PL, ED and TEM. The TEM image clearly showed the homogeneous dispersion of CdS–PAM nanocomposites with the dimension of 50 nm.
Enhanced DNA Cleavage by Mercury(II) Porphyrin at a Low Concentration of HaeIII Restriction Enzyme
Authors: Nyarko Elvis , Tabata Masaaki , Watanabe Keiichi
Published: March 2003

Mercury(II) porphryin enhanced DNA cleavage in the presence of 0.2 units µL−1 of HaeIII at which concentration the restriction enzyme could not cleave DNA in the absence of the porphyrin. This was ascribed to the synergistic effect of the bound Hg2+ ions to DNA and the intercalated free base porphyrin, released from the mercury(II) porphyrin complex upon binding to DNA, which was confirmed by UV–visible and CD spectroscopic measurements.
Occupational risk in health care and research
Authors: Vecchio Daniela , Sasco Annie J. , Cann Cristina I.
Published: March 2003

Background

Working in the health care and research sectors has been linked to various hazards.

Methods

Studies published in the peer‐reviewed literature that are pertinent to the exposures or diseases relevant to these fields were reviewed.

Results

The most important exposures include infectious agents, formaldehyde, anesthetic agents, antineoplastic drugs, and ethylene oxide. The best‐documented evidence is that of infectious risk primarily among clinical personnel. Monitoring studies of persons occupationally exposed to anesthetics clearly demonstrate behavioral effects, possible risk of reproductive problems, as well as cytogenetic effects of unknown significance. The latter two impairments are also observed among those exposed to antineoplastic drugs and ethylene oxide. Exposure to formaldehyde appears to be associated with nasopharyngeal tumors. Whereas increased risk of cancer of certain sites, particularly the brain and lymphohematopoietic system, is found among research and health care personnel, no specific exposure has been linked to these neoplasms.

Conclusions

Although some results are inconsistent, continued environmental and biological monitoring will allow better assessment of exposures and of implemented protection measures. Am. J. Ind. Med. 43:369–397, 2003. © 2003 Wiley‐Liss, Inc.
Molecular mechanisms of S100‐target protein interactions
Authors: Zimmer Danna B. , Wright Sadosky Patti , Weber David J.
Published: March 2003

S100 proteins have no known enzymatic activity and exert their intracellular effects via interaction with and regulation of the activity of other proteins, termed target proteins, in both a Ca2+‐dependent and Ca2+‐independent manner. Structural studies have identified the linker region between the two EF‐hand Ca2+binding domains and the C‐terminus as Ca2+‐dependent target protein binding sites in several S100 family members. In fact, C‐terminal aromatic residues are obligatory for interaction of S100A1 with several of its Ca2+‐dependent target proteins. Pharmacological studies suggest the presence of additional Ca2+‐dependent binding motifs on some family members. A minimum of seven family members interact with and regulate the activity of aldolase A in a Ca2+‐independent manner. In the case of S100A1, Ca2+‐independent target protein interactions utilize a binding motif distinct from the C‐terminal Ca2+‐dependent target protein binding site. Several studies suggest that ionic interactions participate in the interaction of S100 family members with Ca2+‐independent target proteins. While some target proteins are activated by multiple family members, other target proteins exhibit family member‐specific activation, i.e., they are activated by a single family member. As predicted, family member specific interactions appear to be mediated by regions that exhibit the most divergence in amino acid sequence among family members, the linker or “hinge” region and the C terminus. Further specificity in S100‐target protein interactions may arise from the different biochemical/biophysical properties of the individual family members, including affinity for metal ions (Ca2+, Zn2+, and Cu2+), oligomerization properties, heterodimerization, post‐translational modifications, and lipid‐binding. Delineation of the structural motifs that mediate S100‐target protein interactions and determination of the in vivo relevance of these interactions are needed to fully understand the role of S100 proteins in normal and diseased cells. Microsc. Res. Tech. 60:552–559, 2003. © 2003 Wiley‐Liss, Inc.
Altered levels of cerebrospinal fluid reelin in frontotemporal dementia and Alzheimer's disease
Authors: Sáez‐Valero Javier , Costell Mercedes , Sjögren Magnus , Andreasen Niels , Blennow Kaj , Luque Juan M.
Published: March 2003

Reelin is an essential glycoprotein for correct cytoarchitectonic organization during CNS development. Its function in the adult brain is far less well understood, but altered brain and blood reelin levels have been reported in some psychiatric disorders, and the possibility has been considered of an involvement of the reelin signaling pathway in neurodegeneration. Here we report, for the first time, the presence of detectable levels of reelin in rat and human cerebrospinal fluid (CSF) and show evidence for the involvement of a 180‐kDa reelin fragment in two neurodegenerative disorders. This fragment was analyzed by Western blotting in CSF samples from 13 healthy control individuals and 14 frontotemporal dementia (FTD) and 20 Alzheimer's disease (AD) patients. Increased CSF 180‐kDa reelin was found in FTD (161.7 ± 6.7 arbitrary units; a.u.) and AD (151.4 ± 3.8 a.u.) compared with control individuals (141.4 ± 1.2 a.u., P < 0.05). Our results strongly suggest the involvement of reelin signaling in neurodegenerative pathologies. © 2003 Wiley‐Liss, Inc.
Bulk viscoelastic contribution to the wet‐sliding friction of rubber compounds
Authors: Pan Xiao‐Dong , Kelley Edward D. , Hayes Michael W.
Published: March 2003

The wet‐sliding friction characteristics of rubber compounds made of high cis‐polybutadiene were examined with a British pendulum skid tester at room temperature. Three series of compounds were prepared—unfilled or filled with carbon black at two different levels. The bulk viscoelastic properties as characterized by the bulk glass‐transition temperature for the compounds were systematically adjusted by changing the crosslinking density via sulfur vulcanization. In fact, the dynamic mechanical glass‐transition temperature for the compounds ranges between approximately −100 and 20 °C. Consequently, the wet‐sliding friction of these rubber compounds is dramatically affected. With increasing compound glass‐transition temperature, the wet‐sliding friction increases to a maximum and then decreases. However, the rate of increase or decrease varies with the amount of filler in the compounds. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 757–771, 2003
Evaluation of an enzyme immunoassay for the detection of the insect growth regulator fenoxycarb in environmental and biological samples
Authors: Le Hong T M , Szurdoki Ferenc , Székács András
Published: March 2003

A competitive enzyme‐linked immunosorbent assay (ELISA) for fenoxycarb was adapted for quantitative detection of this insect growth regulator in various environmental, agricultural, food and biological matrices. Environmental samples were taken from soil and surface waters in Hungary. The ELISA enabled fenoxycarb detection in surface waters in the 1.1–125 ng ml−1 concentration range without sample cleanup. In contrast, soil produced a strong matrix effect due to humic acids and other soil components. Several fruit homogenates and commercial fruit juices (eg apple, pear, grape) were analyzed by the ELISA. The assay was found to be suitable for analysis of fenoxycarb in fruit juices diluted 1:40. Biological samples included insect, fish and bovine tissues. The ELISA was applied to detect fenoxycarb in various biological matrices from larvae of the silkworm, Bombyx mori L. The assay proved useful for the analysis of haemolymph diluted 1:10 or at higher dilutions. Fat body and whole body homogenates, however, caused severe matrix effects. Fenoxycarb was detected in liver homogenates (diluted 1:40) from fish treated with various doses of fenoxycarb, and the concentrations determined correlated with the applied doses. The method was used to analyze spiked bovine urine samples diluted 1:10 or at greater dilutions. Fenoxycarb content determined by the ELISA in water and fruit juice samples was validated using GC‐MS with solid‐phase microextraction (SPME) sample preparation. The results of these studies demonstrated both the value and limitations of the assay when used for monitoring fenoxycarb in environmental, food and biological samples.

© 2003 Society of Chemical Industry
Local early induced resistance of plants as the first line of defence against bacteria
Authors: Klement Zoltán , Bozsó Zoltán , Kecskés Mihály L , Besenyei Eszter , Arnold Czelleng , Ott Péter G
Published: March 2003

This paper is an overview of a non‐specific local early induced resistance (EIR) mechanism, distinct from the incompatible‐specific hypersensitive reaction (HR). We have shown that the local induced resistance (LIR) described earlier is not a single and uniform response to pathogen infection, because an early (EIR) and a late form can be distinguished. EIR operates from 3–6 h post‐inoculation (hpi) until about 20 hpi, and is inhibited by a short heat‐shock or the eukaryotic protein synthesis inhibitor, cycloheximide. In contrast, LIR, which corresponds to the induced resistance forms discovered earlier, requires more time (about 24 h) and intensive illumination to develop, and is effective for a longer period. EIR develops parallel with HR and is sometimes able to prevent it when the induction time of HR is longer than the time required for the development of EIR. It seems that EIR inhibits the metabolism of bacteria and the activity of hrp genes which otherwise are required for the induction of HR. In a compatible host–pathogen relationship the effect of EIR fails to take place. The rapid development of EIR is greatly influenced by temperature and the physiological state of the plant. EIR activates the accumulation of hydrogen peroxide at the bacterial attachment, expressing new peroxidase isoenzymes in the initiated plant tissue. It seems that this is a native general local defence mechanism which can localise foreign organisms even at the penetration site.

© 2003 Society of Chemical Industry
Environmental complexity has different effects on the structure of neurons in the prefrontal cortex versus the parietal cortex or nucleus accumbens
Authors: Kolb Bryan , Gorny Grazyna , Söderpalm Anna H. V. , Robinson Terry E.
Published: March 2003

Complex housing has been used widely as a model of experience‐dependent change. Animals housed in complex environments typically show synaptogenesis throughout the sensory and motor cortex as well as the striatum and hippocampus, and thus it is generally assumed that such changes are likely to be found throughout the cerebrum. The purpose of the present study was to determine whether persistent alterations of dendritic morphology would be found in two regions that had previously not been examined, namely, the medial prefrontal region (Cg3) and nucleus accumbens (NAcc). The results show that housing female rats in complex environments for 3.5 months increased dendritic arborization on medium spiny neurons in the NAcc and on pyramidal cells in the somatosensory cortex (Par 1), but not in Cg3. Environmental complexity increased spine density in all three areas, however. The failure to find increased dendritic length or branching in Cg3 was unexpected. Thus, the data suggest that complex housing may not engage prefrontal neurons in the same manner as neurons in sensory or motor areas. It appears that complex housing may not produce generalized changes in cerebral morphology. The data further suggest that it is prudent to measure both dendritic length and spine density in studies of experience‐dependent effects on synaptic plasticity. Synapse 48:149–153, 2003. © 2003 Wiley‐Liss, Inc.
Effect of Bee Venom Treatment in Sows with Oligogalactic Syndrome Postpartum
Authors: Choi Seok Hwa , Kang Seong Soo , Bae Chun Sik , Cho Seong Koo , Pak Sok Cheon
Published: March 2003

The objective of this study was to determine the clinico-therapeutic effect of worker honeybee venom in sows with oligogalactic syndrome postpartum. Comparison between bee venom- and drug-treated groups was our main concern in the present study. Sows after parturition were assigned to bee venom- and drug-treated groups, respectively. In the bee venom-treated group, 22 sows were bee-acupunctured once a day for 3 consecutive days. Honeybees (Apis mellifera L.) for bee acupuncture were about 15 days old after metamorphosis. Live bees were used to sting the acupoints known as Yang-ming (ST-18, 1.5 cm lateral to the base of the last two pairs of teats) and Jiao-chao (GV-1, at the indentation between the base of tail and the anus). In the drug-treated group, 20 sows were intramuscularly injected with a standard dose of penicillin G (400,000 IU/head) once a day for 3 consecutive days. On post-treatment day 4, 85.0% of the drug-treated group and 90.9% of the bee venom-treated group recovered from oligogalactic syndrome postpartum. The result suggested that apitherapy using worker honeybee is an effective treatment for sows with oligogalactic syndrome postpartum.
In Situ Observation of Adsorbed Heptylviologen Cation Radicals by Slab Optical Waveguide Spectroscopy Utilizing Indium-tin-oxide Electrode
Authors: Matsuda Naoki , Takatsu Akiko , Kato Kenji , Shigesato Yuzo
Published: March 2003

In situ observation of absorption spectra of heptylviologen cation radical (HV+·) was performed by slab optical waveguide (SOWG) spectroscopy utilizing indium-tin-oxide (ITO) electrodes. It was found that HV+· existed as both monomer and dimer on ITO with a monolayer deposition. With Nafion coated ITO, a band at about 555 nm disappeared, which indicated that this band was assigned to the adsorbed species consisting of HV+· and the counter anion (Br−).
Detection of Radicals and Radical Pairs in Photo-irradiated 2,4,6-Triisopropyl-4′-methoxycarbonylbenzophenone in the Solid State
Authors: Yamauchi Jun , Yasui Satoshi , Ito Yoshikatsu
Published: March 2003

Polycrystalline 2,4,6-triisopropyl-4′-methoxycarbonylbenzophenone was photo-irradiated in vacuo and the colored solid obtained exhibited intense ESR signals which are attributable to mono-radical and radical pair species. These are intermediates after the hydrogen abstraction by photo-excited carbonyl from isopropyl group.
Preparation of a Hybrid Preceramic Precursor for Al-Si-C-N Nanocomposites via a Molecular Building Block Approach
Authors: Koyama Seiichi , Nakashima Hiroaki , Sugahara Yoshiyuki , Kuroda Kazuyuki
Published: March 2003

The reaction between (HAlNPri)m (Pri = CH(CH3)2) and [MeSi(H)NH]n (Me = CH3) led to hydrogen elimination to form a hybrid precursor. Thermogravimetry revealed that the ceramic yield of the hybrid precursor was much higher than those of (HAlNPri)m and [MeSi(H)NH]n, which was ascribed to the hydrogen elimination condensation between the AlH groups in (HAlNPri)m and the NH groups in [MeSi(H)NH]n during precursor synthesis and pyrolysis. The pyrolyzed product under Ar was a mixture of β-SiC, β-Si3N4 and 2H wurtzite-type compound, and the particle sizes were in the range of 20-30 nm.
Stereoselective Formation of [Cr(edda or eddp)(N-N)]-Type Complexes with 1,10-Phenanthroline (edda=ethylenediamine-N,N′-diacetate; eddp=ethylenediamine-N,N′-dipropionate)
Authors: Yonemura Toshiaki , Nakayama Ryoko , Sakagami Narumi , Okamoto Ken-ichi , Ama Tomoharu , Kawaguchi Hiroshi , Yasui Takaji
Published: March 2003

The [Cr(edda or eddp)(N-N)]-type complexes (edda=ethylenediamine-N,N′-diacetate; eddp=ethylenediamine-N,N′-dipropionate), trans(O)-[Cr(edda)(phen)]Cl and csi(O)-[Cr(eddp)(phen)]Cl, were first prepared stereoselectively and characterized by UV-Vis absorption and IR spectra and X-ray crystal analysis. The optically active (−)CD510-[Cr(edda)(phen)]+ was readily racemized even in an acidic aqueous solution within a period of several hours.
Reactions of [Chloro(1,2-phenylenedioxy)silyl]iron Complex Cp(CO)2FeSiCl(o-O2C6H4) with Nucleophiles
Authors: Yamaguchi Koji , Ueno Keiji , Ogino Hiroshi
Published: March 2003

Reactions of FpSiCl(cat)(1:Fp=(η5-C5H5)Fe(CO)2, cat=o-O2C6H4) with lithium 2-(dimethylaminomethyl)phenoxide(LiOArN) afforded FpSi(cat)(OArN) (2), while that with acetylacetone resulted in the formation of a mixture of a hexacoordinate silicon compound Si(cat)(acac)2 (acac=η2-CH3COCHCOCH3) and FpH. Structural determination of 2 by X-ray crystallography revealed that there is no interaction between the silicon atom and the dimethylamino group.
Tetralkylammonium Permanganate Epoxidation of an Unreactive Double Bond by an Intramolecular Oxygen-atom Transfer Process
Authors: Caycho Juana Robles , García-Tellado Fernando , Armas Pedro de , Marrero-Tellado Jose Juan
Published: March 2003

The ammonium permanaganate oxidation of a tricyclic, rigid diene gives the mono- dihydroxylated compound together with the diol- epoxide derivative. The epoxidation involves an intramolecular oxygen- atom transfer process from the anchored manganese (V) diester to the second double bond.
Kinetics of Chain Organization at the Thermochromic Transition of Polysianes
Authors: Sanji Takanobu , Sakamoto Kenkichi , Sakurai Hideki
Published: March 2003

Kinetics of the conformational transition of polysilanes was studied by monitoring the time dependent changes in UV absorption. The conformational change is regarded as a process of the crystallization and its time evolution in conformity to the scaling law with three-dimensional growth of the transition.
A Novel Meso-Oxygenation of an Iron Porphyrin Complex Related to Meso-Hydroxylation Catalyzed by Heme Oxygenase
Authors: Murakami Tatsuya , Watanabe Yoshihito , Morishima Isao
Published: March 2003

A novel iron porphyrin complex, FeIII(BMBpCPP) (1a), in which two meso-positions are less hindered, is converted to an iron(III) isoporphyrin complex (3a) via an intermediate (2a) by the reaction with 1 equiv of pNPBA in CH2Cl2 at −70 °C.
Unusual Solvatochromism of a New Conjugated Polymer Containing Oxadiazole
Authors: Meng Hong , Yu Wang-Lin , Huang Hsing Hua , Huang Wei
Published: March 2003

The spectroscopic properties of a new synthesized conjugated polymer constituted of 3,3′-didecyl-2,2′-bithiophene and 2,6-di-1,3,4-oxadiazole-toluene moieties in the mixed solvent system of chloroform (solvent for the polymer) and methanol (non-solvent for the polymer) were studied. An unusual solvatochromism either in absorption or in emission was observed for the first time on conjugated polymers containing oxadiazole.
Kaolinitic Clay Catalyzed Reaction of Sulfur Monochloride with Aromatics: An Efficient and High Yield Synthesis of Symmetrical Disulfides
Authors: Vyas Renu , Chanda Bhanu , Sudalai A
Published: March 2003

Kaolinitic clay efficiently catalyses the reaction of sulfur monochloride with arenes to yield symmetrical 4,4′ arene disulfides in a single step under heterogeneous phase.
A Novel Synthesis of 1,3-Diol Diesters by the Reaction of Aldehydes with Oxime Esters Catalyzed by Samarium Complex
Authors: Kawasaki Yumi , Tashiro Daisuke , Sakaguchi Satoshi , Ishii Yasutaka
Published: March 2003

CP*2Sm(thf)2 was found to be an efficient catalyst for the synthesis of 1,3-diol diesters by the coupling reaction of aldehydes with oxime esters under mild conditions. For instance, the reaction of acetaldehyde with cyclohexanone oxime acetate catalyzed by CP*2Sm(thf)2 gave 1,3-diacetoxybutane in 70% yield. Treatment of acetaldehyde with isopropenyl acetate in the presence of a small amount of cyclohexanone oxime acetate and Cp*2Sm(thf)2 resulted in the corresponding 1,3-diol diester in good yield.
Synthesis of a New Nitrone for Detection of Radical Species
Authors: Sato Rikiya , Nakahashi Kenichi , Iwadate Hiroshi , Takeishi Makoto , Igarashi Takashi , Obara Heitaro , Kamada Hitoshi
Published: March 2003

A water-soluble new nitrone, α-(2-pyridyl) N-(2-hydroxy-1,1-dimethylethyl) nitrone, was synthesized and found to be useful for selective detection of oxygen-centered radicals in aqueous reactions.
Reaction of 1,3-Dihalopropene with Trialkylmanganate
Authors: Kakiya Hirotada , Inoue Rie , Shinokubo Hiroshi , Oshima Koichiro
Published: March 2003

A three-component coupling reaction was performed. Treatment of 1,3-dibromopropene or 1,3-dichloropropene with tributylmanganate (n-Bu3MnLi) provided a butylated allylmanganese compound which could be trapped by an electrophile such as benzaldehyde.
Reduction of Dicationic Porphyrin with N21,N22- and N23,N24- Double Bridge
Authors: Setsune Jun-ichiro , Kashihara Kenji , Wada Ken-ichi
Published: March 2003

Novel 5H,10H-isoporphomethenes were obtained by the NaBH4 reduction of dicationic porphyrin with N21,N22-(1,2-diphenyletheno) and N23,N24-(ethoxycarbonylmethano) double bridge.
An Expeditious Synthesis of Optically Pure 1,4,5,6-Tetrahydro-as-Triazines, Fused to the Carbohydrate Skeleton
Authors: Saeed Muhammad , Abdel-Jalil Raid J , Voelter Wolfgang , El-Abadelah Mustafa M.
Published: March 2003

An easy and high yield one pot reaction to enantiomerically pure 1,4,5,6-tetrahydro-as-triazines 5a–d and 8a–d is described, starting from benzyl 4-amino-2,3-anhydro-4-deoxy-β-l-lyxopyranoside (3) and benzyl 4-amino-2,3-anhydro-4-deoxy-α-d-lyxopyranoside (6).
Partial Oxidation of Methane over Ni/θ-Al2O3 Catalysts
Authors: Roh Hyun-Seog , Jun Ki-Won , Dong Wen-Sheng , Park Sang-Eon , Joe Yung-Il
Published: March 2003

Ni/θ-Al2O3 exhibits remarkably high catalytic activity and stability in partial oxidation of methane to synthesis gas. It gives more than 98% CH4 conversion, 98% H2 selectivity and 100% CO selectivity at 850 °C and the activity was maintained for 100 h.
The Metal Complex of 2-[2-(4-Cyanophenyl)ethenyl]-8-hydroxyquinoline (2-CEHQ) Ligand: A Novel Trinuclear Zinc(II) Complex with Red Light Emission
Authors: Zhang Jing , Xiong Ren-Gen , Chen Zhen-Feng , You Xiao-Zeng , Lee Gene-Hsiang , Peng Shie-Ming
Published: March 2003

A neutral trinuclear zinc(II) complex containing 2-[2-(4-cyanophenyl)ethenyl]-8-quinolinol (2-CEQH) with strong red light emission was synthesized by hydro(solvo)thermal reaction and its structure was determined by X-ray single crystal diffraction study.
Layered Lithium Insertion Material of LiNi1/2Mn1/2O2 : A Possible Alternative to LiCoO2 for Advanced Lithium-Ion Batteries
Authors: Ohzuku Tsutomu , Makimura Yoshinari
Published: March 2003

We have successfully prepared a layered nickel manganese oxide of LiNi1/2Mn1/2O2 (a = 2.89 Å and c = 14.30 Å in hexagonal setting) and shown that this material may be a possible alternative to LiCoO2 for advanced lithium batteries in terms of the operating voltage, rechargeable capacity, cycleability, safety, and materials economy.
First Electrochemical Reductions of C84 Films on Electrodes
Authors: Nakashima Naotoshi , Wahab Nor Wahida Binti , Mori Makoto , Murakami Hiroto , Sagara Takamasa
Published: March 2003

The higher fullerene C84 embedded in cast films of molecular-bilayer-forming cationic lipids on electrodes was found to exhibit evident electron transfer reactions leading to the generation of C84 multi-charged anions.
Deuterium Nuclear Magnetic Resonance Study of Lipophilic Chains in the C12E3/Decane/Water Ternary System
Authors: Tonegawa Akimitsu , Michiue Ayako , Ohno Keiichi , Matsuura Hiroatsu , Yamada Koji , Okuda Tsutomu
Published: March 2003

The order parameters of lipophilic chains in the liquid crystalline phases of the C12E3/decane/water ternary system have been studied by deuterium NMR spectroscopy. The order parameters derived indicate that the decane molecules added to the C12E3/water system penetrate into the lipophilic alkyl layer of the surfactant and make the structure of the lipophilic layer disordered. The lipophilic layers in the reversed hexagonal phase are more disordered than those in the lamellar phase.
Shift of Fe 3d Band due to Chlorine for Fe(III)(salen)
Authors: Shigemi Akio , Tochio Tatsunori , Fujiwara Manabu , Kawai Jun , Matsushita Takayuki , Isozumi Yasuhito , Mukoyama Takeshi , Ikeda Shigero
Published: March 2003

The valence band (VB) spectrum of an iron(III) complex, [Fe(salen)Cl], in X-ray photoelectron spectroscopy (XPS) has been calculated with the DV-Xα molecular-orbital method. The influence of chlorine (Cl) in the VB spectrum is examined. It is found that the shallowest binding energy peak in VB spectrum originates from Cl 3p and Fe 3d, and Fe 3d band is deepened due to chlorine for the Fe(III) Schiff base complex in the XPS VB spectra.
Chromophoric System of Unsymmetrical Indamine Dyes Derived from (Diethylamino)thiazole Dimer
Authors: Kim Jae Joon , Funabiki Kazumasa , Shibata Katsuyoshi , Muramatsu Hiroshige , Shiozaki Hisayoshi , Matsui Masaki
Published: March 2003

Unsymmetrical indamine dyes have been synthesized by the reaction of (diethylamino)thiazole dimer with 4-nitrosoanilines followed by heating with metal salts. The chromophoric system for these indamine dyes was described as the mixture of the π–π* transition coming from the alternant chromophore inside the bithiazolyl moiety and the charge-transfer from anilino to bithiazolyl moieties.
Selective Hydrogenation of 2-Methylbenzaldehyde Using Palladium Particles Generated in situ in Surfactant Exchanged Fluorotetrasilicic Mica
Authors: Sivakumar Thiripuranthagan , Mori Tohru , Kubo Jun , Morikawa Yutaka
Published: March 2003

Palladium intercalated surfactant-exchanged fluorotetrasilicic mica (Pd-HDP-TSM) was synthesized by ion exchange of surfactant with TSM, intercalation and in situ reduction of palladium. This catalyst showed the highest selectivity to 2-methylbenzyl alcohol for the title reaction when compared with supported catalysts. Interestingly, in contrast with the supported catalysts, Pd-HDP-TSM catalysts do not favor the consecutive reaction yielding the hydrogenolysis products such as xylene and toluene.
Lattice Structure of Mesoscopic Rod-like J Aggregates of Thiacyanine Dye Characterized by Atomic Force Microscopy
Authors: Yao Hiroshi , Kitamura Shin-ichi , Kimura Keisaku
Published: March 2003

We characterized the lattice structure of mesoscopic rod-like J aggregates of thiacyanine dye on mica possessing similar morphological and spectroscopic characteristics with those in bulk solution. The structure showed a staircase molecular arrangement.
Selective Synthesis of Chlorohydrogermanes from Mono-, Di-, and Trihydrogermanes
Authors: Ohshita Joji , Toyoshima Yutaka , Iwata Arihiro , Tang Heqing , Kunai Atsutaka
Published: March 2003

Treatment of hydrogermanes, R4−nGeHn (R = Hex, Et, Ph, n = 1–3), with 2 equiv of CuCl2 in ether at room temperature or in toluene under reflux led to selective replacement of an H–Ge bond with a Cl–Ge bond, giving the corresponding chlorohydrogermanes, R4−nGeHn−1Cl, selectively.
Enantioselectivity in the Hydrolysis by Lipase: A Study of MALDI TOF-MS Analysis
Authors: Utsumi Ryoichi , Izumi Shunsuke , Hirata Toshifumi
Published: March 2003

The mechanism of the enantioselectivity of lipase has been investigated by MALDI TOF-MS with photoaffinity probes. When 1-phenylethyl m-benzoylbenzoate was used as a photoaffinity probe, both the enantiomer that reacts as a substrate of lipase and the non-reactive enantiomer combined with lipase. However, in the case of isobornyl m-benzoylbenzoate, only the reactive photoaffinity probe combined with lipase.
Synthesis of DNA Templates Containing the Fifth Base, 2-Amino-6-(dimethylamino)purine, for Specific Transcription Involving Unnatural Base Pairs
Authors: Hirao Ichiro , Nojima Takahiko , Mitsui Tsuneo , Yokoyama Shigeyuki
Published: March 2003

An unnatural nucleobase, pyridin-2-one (denoted as y), can be specifically incorporated into RNA opposite 2-amino-6-(dimethylamino)purine (denoted as x) in DNA templates by T7 RNA polymerase. For the easy preparation of DNA templates containing x, protecting groups for the 2-amino group of x were examined. Although the general N2 protecting groups, such as isobutyryl and acetyl, resisted removal by the usual treatment with concentrated ammonia at 55 °C for 6 h, the N2-phenoxyacetyl group was successfully removed from the protected oligomers. This DNA synthesis would be a useful method for preparation of DNA templates toward enzymatic incorporation of unnatural nucleosides into RNA at desired positions.
Formation and Electrochemical Characteristics of Multilayers of Au Nanoclusters Covered by Mixed Self-Assembled Monolayers of Three Kinds of Alkanethiols with Methyl, Ferrocene, or Carboxylate Terminal Group on Au(111) Surface
Authors: Kondo Toshihiro , Okamura Masayuki , Uosaki Kohei
Published: March 2003

Multilayers of Au nanoclusters covered by self-assembled monolayers containing a mixture of three kinds of alkanethiols terminated by methyl, ferrocene, or carboxylate groups were constructed on a Au(111) surface based on the electrostatic interaction between a carboxylate anion and metal cation. Electrochemical measurements showed that an electron is transferred between ferrocene and the Au(111) electrode through the Au nanocluster cores and/or ferrocene groups.
Ultrasonic Enhancement on the Hydrolysis of Diethyl 1,2-Benzenedicarboxylate
Authors: Yim Bongbeen , Yoo Youngeok , Nagata Yoshio , Maeda Yasuaki
Published: March 2003

The ultrasonic enhancement on the hydrolysis of diethyl 1,2-benzenedicarboxylate results from the dissipated heat when the cavitation micro-bubbles were vigorously collapsed. The effective temperature in a solution depends on the nature of the dissolved gas. The relatively broad region that spreads from the interface of the cavitation micro-bubble plays an important role in the sonolytic hydrolysis of esters.
A 207Pb NMR study of the adducts of triphenyllead chloride and diphenyllead dichloride
Authors: Margolis Lara A. , Schaeffer Charles D. , Yoder Claude H.
Published: March 2003

207Pb NMR spectra were used to determine the structure of adducts of triphenyllead chloride and diphenyllead dichloride in CH2Cl2 and CH3CN. The bases included several phosphorus donors, such as tributylphosphine, oxygen donors, such as tributylphosphine oxide, and nitrogen donors, such as pyridine. A number of bidentate bases were also studied. The 207Pb spectra indicate that rapid exchange occurs in the adducts, even at temperatures of −90 °C. The magnitude of the shift relative to the lead acid indicates that all of the bases, including the bidentate bases, form five‐coordinate adducts with triphenyllead chloride. Diphenyllead dichloride forms six‐coordinate adducts, except for the adduct with tributylphosphine, which is five‐coordinate. This is the first report of a five‐coordinate adduct of diphenyllead dichloride. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of pyrano‐Agarofurans
Authors: Boyer François‐Didier , Descoins Charles , Ducrot Paul‐Henri
Published: March 2003

This paper describes the synthesis of pyrano‐agarofuran tetraol 8. The key step of the synthesis lies in the stereoselectivity encountered in the hydrogenation of precursor 13 because of its peculiar cis‐decalinic conformation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The Structure of 4‐Benzoyl‐5‐methyl‐2‐phenylpyrazol‐3‐one Oxime and Its Methyl Derivatives
Authors: Holzer Wolfgang , Hahn Katharina , Brehmer Thomas , Claramunt Rosa M. , Pérez‐Torralba Marta
Published: March 2003

1H and 13C NMR spectroscopic investigations of 4‐benzoyl‐5‐methyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one oxime (4) and different methylation products thereof (5−11) indicate that 4 exists predominantly as 4‐enaminopyrazolone in [D6]DMSO solution. Single‐crystal X‐ray analysis revealed that in the solid state the same tautomeric structure of 4 was present, and closely resembles that of the corresponding N‐methylamino product (6). Both compounds are stabilised by an intramolecular hydrogen bond between the pyrazolone C=O group and the N‐OH proton. A 1,2‐dihydro‐3H‐pyrazol‐3‐one structure was found in a clathrate of O‐methyloxime 5 and dichloromethane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
First Partially Intramolecular Palladium‐Catalyzed [2+2+2] Cycloaddition of Benzyne: Application to the Synthesis of Benzo[b]fluorenones
Authors: Peña Diego , Pérez Dolores , Guitián Enrique , Castedo Luis
Published: March 2003

The palladium(0)‐catalyzed reaction of benzyne with suitably functionalized benzodiynes to afford benzo[b]fluorenones is described. The outcome of the reaction is affected by the steric and electronic properties of the diynes and proved to be regioselective when an unsymmetrically substituted aryne is used. This work represents the first example of a partially intramolecular [2+2+2] cycloaddition involving arynes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Easy Synthesis of New Chiral Tetradentate N4 Schiff Bases and Their Use as Ligands for Metal Complexes
Authors: Karamé Iyad , Tommasino M. Lorraine , Faure René , Lemaire Marc
Published: March 2003

The chiral N4 Schiff bases (1R,2R)‐N,N′‐bis(2‐p‐tosylaminobenzylidene)‐1,2‐diaminocyclohexane (H2CyTs, 1), (1R,2R)N,N′‐bis(2‐trifluoromethylsulfonaminobenzylidene)‐1,2‐diaminocyclohexane (H2CyTf, 2), (1R,2R)‐N,N′‐bis(2‐aminobenzylidene)‐1,2‐diaminocyclohexane (3) and (1R,2R)‐N,N′‐bis(2‐nitrobenzylidene)‐1,2‐diaminocyclohexane (4) were synthesized by a new and easy method in high purity and good yields. All the organic compounds were characterized by elemental analysis, mass spectrometry, IR and 1H and 13C NMR spectroscopy. Divalent Co, Cu and Ni complexes 5−8, containing the sulfonamide ligands 1 or 2, have been prepared and characterized. The X‐ray crystal structures of complexes [Co(1R,2R)‐CyTs] (6) and [Ni(1R,2R)‐CyTf] (8) have been solved. These complexes are potential precursors for homogeneous asymmetric catalysis of a variety of reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Alcohol‐induced memory impairment in trace fear conditioning: A hippocampus‐specific effect
Authors: Weitemier Adam Z. , Ryabinin Andrey E.
Published: March 2003

It has been hypothesized that the amnesic effects of alcohol are through selective disruption of hippocampal function. Delay and trace fear conditioning are useful paradigms to investigate hippocampal‐dependent and independent forms of memory. With delay fear conditioning, learning of explicit cues does not depend on normal hippocampal function, whereas learning explicit cues in trace fear conditioning does. In both delay and trace fear conditioning, the hippocampus is involved in learning to contextual cues, but it may not be entirely necessary. The present study investigates the effects of alcohol on the acquisition of delay and trace fear conditioning in mice, using freezing as a measure of learning. Male C57BL/6J mice were injected with 0.8 or 1.6 g/kg of 20% v/v alcohol and were immediately exposed to eight tone‐footshock pairings in which the conditional stimulus (CS) either coterminated with a footshock unconditional stimulus (US) (delay conditioning) or was separated from the footshock by a 30‐s trace interval (trace conditioning). During trace, but not delay fear conditioning, 0.8 g/kg alcohol impaired learning to a tone CS. This dose also impaired context‐dependent learning in both procedures (although only slightly for trace fear conditioning). The 1.6 g/kg alcohol exerted a nonselective impairment on learning. The impairment by alcohol of learning to a tone CS when it is hippocampus‐dependent, but not when it is hippocampus‐independent provides further support for the hypothesis that alcohol exerts a selective effect on hippocampus‐dependent learning. Hippocampus 2003;13:305–315. © 2003 Wiley‐Liss, Inc.
Involuntary, unreinforced (pure) spatial learning is impaired by fimbria‐fornix but not by dorsal hippocampus lesions
Authors: White Norman M. , Holahan Matthew R. , Goffaux Philippe
Published: March 2003

Pure spatial learning occurs when rats acquire information about an environment while exploring it in the absence of reinforcers. We previously reported that voluntary, unreinforced exploration of a radial maze retards subsequent reinforced conditioned cue preference (CCP) learning in the same maze. In the present experiment, we examined the effects of involuntary, unreinforced pre‐exposure to a radial maze. During pre‐exposure, rats were moved by an experimenter between the ends of two arms of a radial maze five times in 30 min. This form of pre‐exposure retarded CCP learning, whereas rats that were not pre‐exposed and rats that were pre‐exposed to a maze in a different room displayed normal CCP learning. These findings suggest that some information specific to the maze environment was acquired during involuntary unreinforced pre‐exposure to it. In experiment 2, the retardation of reinforced CCP learning by involuntary unreinforced pre‐exposure was eliminated by fimbria‐fornix lesions made before pre‐exposure but was unaffected by fimbria‐fornix lesions made after pre‐exposure but before training. Large neurotoxic lesions of the dorsal hippocampus made before pre‐exposure had no effect on the retardation of CCP learning, but the rats with these lesions were impaired on a standard test of reinforced spatial learning in a water maze. The lesion effects in experiment 2 are similar to those previously reported for voluntary exploration and suggest that pure spatial learning may occur during both voluntary exploration of and involuntary exposure to an environment in the absence of reinforcers. Pure spatial learning can apparently occur with exposure to two different locations within an environment, but the rats do not have to move between the locations voluntarily. An intact fimbria‐fornix is required for acquisition but not expression of this form of learning. The hippocampus is not involved in this form of learning. Hippocampus 2003;13:324–333. © 2003 Wiley‐Liss, Inc.
Monitoring of S100 homodimerization and heterodimeric interactions by the yeast two‐hybrid system
Authors: Deloulme Jean Christophe , Gentil Benoît Jean , Baudier Jacques
Published: March 2003

The S100 family consists of 19 members, which function as transducers of calcium signals in a tissue‐specific manner. Upon calcium binding, the conformation of many S100 proteins changes dramatically. Several hydrophobic residues are exposed, allowing the S100 proteins to interact with their target proteins, and thereby to transduce calcium signals into specific biological responses. To further elucidate the exact contribution of the S100 calciproteins in the calcium signalling pathways, several groups have applied the yeast two‐hybrid technology to identify putative target proteins for the various S100 calciproteins. Two‐hybrid large screens using S100 proteins as baits have confirmed the biochemical and structural feature of S100, which enable them to form homodimers and the ability of some members to form specific heterodimers in vivo. Yeast two‐hybrid investigations have allowed the identification of conserved hydrophobic residues and domains that are crucial for the stabilization of S100 homo‐ and heterodimers. Furthermore, this method clearly underlines that the homo‐ and heterodimerization mechanisms differ among the members of the S100 family. However, several lines of evidence strongly suggest that two‐hybrid methodology is limited to the analysis of interactions that are calcium‐independent, since no target proteins other than S100 family members themselves have been detected with this methodology. Microsc. Res. Tech. 60:560–568, 2003. © 2003 Wiley‐Liss, Inc.
Gas‐phase ion chemistry in the ternary SiH4–C3H6–PH3 system
Authors: Calderan Stefania , Operti Lorenza , Rabezzana Roberto , Vaglio Gian Angelo
Published: March 2003

Propene–phosphine and the silane–propene–phosphine gaseous mixtures were studied by ion trap mass spectrometry. For the binary mixture the variation of ion abundances under different partial pressures and the mechanisms of ion–molecule reactions are reported. Moreover, the rate constants of the main processes were measured and compared with the collisional rate constants to determine the reaction efficiencies. In the ternary silane–propene–phosphine mixture the mechanisms of formation of $\hbox{Si}_{m}\hbox{C}_{n}\hbox{P}_{p}\hbox{H}_{s}^{+}$ ion clusters were elucidated, but the complexity of the system and the low abundances of the ions usually isolated by successive steps prevented the determination of rate constants. The hydrogenated ternary ions are mainly formed by reactions of $\hbox{Si}_{r}\hbox{P}_{s}\hbox{H}_{t}^{+}$ ions with propene, whereas a minor contribution comes from reactions of $\hbox{Si}_{m}\hbox{C}_{n}\hbox{H}_{p}^{+}$ ions with phosphine. The $\hbox{C}_{v}\hbox{P}_{w}\hbox{H}_{z}^{+}$ ions show very low reactivity with silane. The formation processes of these species are discussed in relation to their possible role as precursors of amorphous silicon carbides doped with phosphorus obtained by deposition from properly activated silane–propene–phosphine mixtures. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of post‐translational modification and characterization of the domain structure of dynamin A from Dictyostelium discoideum
Authors: Schlosser Andreas , Klockow Boris , Manstein Dietmar J. , Lehmann Wolf D.
Published: March 2003

The post‐translational modifications of the 96 kDa protein dynamin A from Dictyostelium discoideum were analyzed using Q‐TOF mass spectrometry. The accurate molecular mass of the intact protein revealed a covalent modification causing an additional mass of 42 Da. The modification could be identified as N‐terminal acetylation by tandem mass spectrometry. Extracted ion chromatograms for the a1 and b1 ion of the tryptic T1 peptide were used to detect the acetylated peptide within 54 nanoelectrospray ionization tandem mass spectra. Owing to the accurate molecular mass of the intact protein, additional covalent modifications could be excluded. In addition to the covalent modification, the domain structure of dynamin A was determined by applying a combination of limited proteolysis, sodium dodecylsulfate polyacrylamide gel electrophoresis, automated tandem mass spectrometry and protein database searching. Copyright © 2003 John Wiley & Sons, Ltd.
A Model for the Elastoplastic Behavior of Isotactic Poly(propylene) Below the Yield Point
Authors: Drozdov Aleksey D. , Christiansen Jesper deC.
Published: March 2003

Observations are reported on isotactic poly(propylene) (iPP) in a series of tensile loading‐unloading tests with a constant strain rate at room temperature. A constitutive model is developed for the elastoplastic behavior of a semicrystalline polymer at isothermal uniaxial deformations with small strains. The stress‐strain relations are determined by 5 adjustable parameters which are found by fitting the experimental data.

The stress σ (MPa) versus strain ε in a tensile loading‐unloading test with the maximum strain εmax = 0.09. Circles: experimental data. Solid line: results of numerical simulation.

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The stress σ (MPa) versus strain ε in a tensile loading‐unloading test with the maximum strain εmax = 0.09. Circles: experimental data. Solid line: results of numerical simulation.
Crystal Orientation Behavior of a Poly(vinylidene fluoride)/Nylon 11 Blend
Authors: Li Yongjin , Kaito Akira
Published: March 2003

The oriented crystallization of poly(vinylidene fluoride) (PVDF) in stretched films of a PVDF/nylon 11 blend was investigated. At low crystallization temperature the c‐axis of the PVDF α‐form was oriented to the orientation axis of the nylon 11 matrix, but c‐axis orientation gradually changed to a‐axis orientation upon increasing the crystallization temperature. Under all crystallization conditions studied, considerable amounts of PVDF in its β‐form with c‐axis orientation were produced as well.

Phase morphology of a stretched film of PVDF/nylon 11 blend observed with confocal laser scanning microscopy.

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Phase morphology of a stretched film of PVDF/nylon 11 blend observed with confocal laser scanning microscopy.
Potato tuber phospholipids contain colneleic acid in the 2‐position
Authors: Fauconnier Marie-Laure , Williams Todd D. , Marlier Michel , Welti Ruth
Published: March 2003

Colneleic acid (9‐[1′(E),3′(Z)‐nonadienyloxy]‐8(E)‐nonenoic acid) is produced from linoleic acid by the sequential action of 9‐lipoxygenase and divinyl ether synthase. We demonstrate that a small fraction of the colneleic acid in potato tubers is esterified in phospholipids. This colneleic acid was released by chemical hydrolysis and a phospholipase A2, but not by a lipase with 1‐acyl specificity. Phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol contain molecular species with nominal masses consistent with identification as palmitoyl,colneleoyl species. Exact mass analysis of its fragments confirmed the identity of palmitoyl,colneloyl phosphatidylinositol. To our knowledge, this work represents the first identification of a colneleoyl phospholipid.
NOISE-INDUCED TRANSMISSION OF SIGNALS THROUGH A CHAIN OF LEVEL-CROSSING DETECTORS
Authors: FUCHIKAMI NOBUKO , SAKAGUCHI TOSHIFUMI
Published: March 2003

We study noise-assisted propagation of periodic signals for one-dimensional arrays composed of one-way coupled level-crossing detectors (LCD). Analytical expressions are obtained for the signal decay length through chains and the signal decay time through rings, where noise is uncorrelated so that the signal transmission from a LCD to the neighboring one is Markovian. Recent numerical simulations for one-dimensional arrays of one-way coupled bistable oscillators are discussed in comparison to the present analytical results.
The Synthesis of Mesoporous Silica Spheres by Octylamine Templating
Authors: Singh Puyam S , Kosuge Katsunori
Published: March 2003

Mesoporous silica hollow spheres have been synthesized by a simple route of hydrolysis of acidic tetraethylorthosilicate solution with octylamine surfactant at ambient temperature. The resultant silica spheres have high BET surface areas of 850 to 950 m2/g and mesopore diameters of ca. 2 nm after the samples were calcined in air at 500 °C. The shell thickness of the spheres can be varied by changing the synthesis composition of the reaction system.
Manganese-catalyzed Phenylation of Acetylenic Compounds with a Phenyl Grignard Reagent
Authors: Yorimitsu Hideki , Tang Jun , Okada Kenji , Shinokubo Hiroshi , Oshima Koichiro
Published: March 2003

Treatment of homopropargylic alcohol derivatives or phenylacetylene compounds with phenylmagnesium bromide in the presence of a catalytic amount of manganese(II) chloride afforded phenylated products in good yields with high regio- and stereoselectivities.
Preparation of Alkenyl Sulfides by the Olefination of Thiolesters Using Thioacetals
Authors: Takeda Takeshi , Watanabe Mikako , Nozaki Naoki , Fujiwara Tooru
Published: March 2003

The reaction of thiolesters with titanocene alkylidenes prepared by the treatment of thioacetals with the low valent titanium species Cp2Ti[P(OEt)3]2 produced the corresponding alkenyl sulfides in good yields with moderate to good Z stereoselectivity.
Synthesis of (η5-Cyclopentadienyl)(η4-cyclopenta-2,4-dien-1-thione)cobalt by the Reaction of Cobaltacyclopentadiene Derivative with CS2 in the Presence of Co(I) Complex
Authors: Lee Jong-Chan , Tomita Ikuyoshi , Endo Takeshi
Published: March 2003

(η5-Cyclopentadienyl)(η4-2,3,4,5-tetraphenylcyclopenta -2,4-dien-1-thione) cobalt was obtained by the reaction of (η5-cyclopentadienyl)triphenylphosphinecobalta-2,3,4,5-tetraphenylcyclopentadiene with CS2 in the presence of cobalt(I) complex in quantitative yield, which was also converted quantitatively to (η5-cyclopentadienyl) (η5-1-methylmercapto-2,3,4,5-tetraphenylcyclopentadienyl) cobalticinium iodide by the treatment with methyl iodide.