bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-lived Colored Merocyanine Conformers in the Aggregates Formed on UV Irradiation of Spiropyran. A Raman Spectroscopic Study
Authors: Onai Yoshiyuki , Kasatani Kazuo , Kobayashi Makoto , Shinohara Hisanori , Sato Hiroyasu 
Published: May 2006

Abstract
Resonance Raman spectra of the aggregate formed on the UV irradiation of 6-nitro-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indoline] (6-nitro BIPS) in nonpolar solvents revealed the presence of long-lived colored merocyanine conformers.
Preparation and Properties of Organic Polymer Ferromagnet with Indigo Unit
Authors: Tanaka Hitoshi , Tokuyama Kouichi , Sato Tsuneyuki , Ota Tadatoshi 
Published: May 2006

Abstract
A new organic polymer ferromagnet with indigo unit in the main chain was prepared and its magnetic properties were examined. Resulting polymer contained the fraction which attracted to a permanent magnet and it showed a definitive hysteresis loop at room temperature.
Reactivities of Sulfur and Selenium in Adduct Formation of (η5-Cyclopentadienyl)(1,2-diphenyl-1,2-ethylenedichalcogenolato)cobalt(III) Complexes with Ethyl Diazoacetate
Authors: Sakurada Masami , Okubo Joe , Kajitani Masatsugu , Akiyama Takeo , Sugimori Akira 
Published: May 2006

Abstract
The reactivity and selectivity of S and Se of (η5-cyclopentadienyl)(1,2-diphenyl-1,2-ethylenedichalchogenolato)cobalt(III) in the alkylidene adduct formation with ethyl diazoacetate were studied. The relative reactivities of dithiolato, selenolatothiolato (1c), and diselenolato complexes are 1 : 26 : 400 at 40 °C. In contrast to the large difference in the reactivities in intermolecular competition, S and Se in 1c reacted with low intramolecular selectivity.
Increasing Packing Density of Hydrated Dipalmitoylphosphatidylcholine Unilamellar Vesicles Induced by Trehalose
Authors: Nishiwaki Tetsuo , Sakurai Minoru , Inoue Yoshio , Chûjô Riichirô , Kobayashi Shôichi 
Published: May 2006

Abstract
On the basis of the observation of 31P{1H} nuclear Overhauser enhancement, trehalose is shown to increase the packing density of the polar head groups of phospholipid unilamellar vesicles. This finding is not consistent with previous results obtained for Langmuir-type membranes or multilamellar vesicles. The present results explain the anti-fusogenic ability of trehalose.
Facile Conversion of the t-Butylthio Group of 1,3,4,6-Tetrakis(t-butylthio)thieno[3,4-c]thiophene into Other Alkylthio Groups Initiated by Protonation
Authors: Tsubouchi Akira , Matsumura Noboru , Inoue Hiroo 
Published: May 2006

Abstract
The t-butylthio group of 1,3,4,6-tetrakis(t-butylthio)thieno[3,4-c]thiophene was converted into other alkylthio groups by treatment with trifluoroacetic acid, followed by alkylation with alkyl iodides.
Synthesis and Structure of Thiolate Complexes Containing (η5-C5Me5)RhIII Groups
Authors: Hou Zhaomin , Ozawa Yoshiki , Isobe Kiyoshi 
Published: May 2006

Abstract
Reaction of [Cp*RhCl2]2 (Cp* = η5-C5Me5) with NaSMe in H2O–MeOH (1:1 by volume) gave [Cp*Rh(μ-SMe)3RhCp*]Cl·2H2O which was converted to [Cp*Rh(μ-SMe)3RhCp*]2[W3S9] by treatment with WS42−. In the presence of MoO3 the reaction led to formation of [Cp*RhCl(μ-SMe)2RhCp*Cl]. X-Ray structure analyses revealed that [Cp*Rh(μ-SMe)3RhCp*]2[W3S9] has three μ2-bridged SMe ligands and that [Cp*RhCl(μ-SMe)2RhCp*Cl] has a syn-planar conformation with two μ2-bridged SMe ligands.
Importance of Apparent Density of BaLa2O4 Catalysts in Oxidative Coupling of Methane
Authors: Yamagata Nobutsugu , Abe Youji , Igarashi Kouji , Ishikawa Takao , Sahara Masae , Okazaki Susumu 
Published: May 2006

Abstract
A voluminous catalyst composed of mainly a composite oxide of BaLa2O4 was found to be effective for oxidative coupling of methane to ethane and ethylene. The high C2 yield is probably due to the low apparent density of the catalyst as well as to its high basicity.
Infrared Studies of the Phototransformation of Phytochrome
Authors: Sakai Jun , Morita Eugene Hayato , Hayashi Hidenori , Furuya Masaki , Tasumi Mitsuo 
Published: May 2006

Abstract
Infrared spectral changes caused by red light irradiation have been observed for pea phytochrome. The results obtained seem to contain useful information for elucidating structural changes of the chromophore and its environment occurring in the phototransformation of phytochrome.
Photochemical Surface Modification of Poly(2-hydroxyethyl methacrylate) Film with 1-(1-Pyrenyl)-2-methylpropene
Authors: Ichinose Nobuyuki , Kitamura Noboru , Masuhara Hiroshi 
Published: May 2006

Abstract
Introduction of pyrenyl group to surface of a poly(2-hydroxyethyl methacrylate) (PHEMA) film was achieved by photoreaction of the film with an acetonitrile solution containing 1-(1-pyrenyl)-2-methylpropene and dimethyl terephthalate (DMTP). Spatial patterning of the film was also explored to show a possible application of the method to microfabrication with photo-functional molecules.
Efficient NAD+-Regeneration System with Heterocyclic o-Quinones and Molecular Oxygen Catalyzed by Diaphorase
Authors: Itoh Shinobu , Mita Naruyoshi , Ohshiro Yoshiki 
Published: May 2006

Abstract
Addition of catalase and diaphorase drastically improved efficiency of the NAD+-regeneration system with heterocyclic o-quinones and molecular oxygen.
Synthesis of α-Keto-steroidal Spiro-thiazolidines
Authors: Takahashi Tomoyoshi , Takahashi Miki , Hashimoto Akira , Satoh Yasuo 
Published: May 2006

Abstract
α-Bromo-steroidal ketones were converted into α-keto spiro-thiazolidine derivatives with β-aminothiols (H2N(CH2)2SH, o-H2NC6H4SH), in pyridine solution at room temperature.
Highly Sensitive Analysis of SnO2/Solution Interface by Internal Reflection–Fluorescence Spectroscopy
Authors: Nakashima Tetsuto , Fujishima Akira 
Published: May 2006

Abstract
Internal reflection-fluorescence Spectroscopy was applied to the analysis of SnO2/solution interface. Changes in the fluorescence intensity of 1,3-di-n-butyl-5-[4-[3,3-dimethyl-1-(-sulfopropyl)-2-indolinylidene]-2 -butenylidene]-2-thiobarbituric acid sodium salt were measured at very low dye concentration as a function of pH. The point of zero charge and the distribution of the positive charge sites of SnO2 thin film surface were investigated. The electrochemical potential of SnO2/solution interface was estimated.
Kinetics of the Reaction between Cobalt and Selenium Vapor at High Temperatures
Authors: Sasaki Yoshinori , Takahashi Kazuhiro 
Published: May 2006

Abstract
Metallic cobalt was selenidized at temperatures of 550–700 °C in selenium vapor at 4.5 kPa. The products were Co3Se4 and CoSe2. All the selenidization reactions proceeded according to a parabolic rate law, and the component which diffused was cobalt.
35Cl NQR Spectra and the Addition Reactions to 2-Chlorobutadiene of N,N-Dichloromethane- and N,N,p-Trichlorobenzenesulfonamide
Authors: Nagao Yoshitaka , Katagiri Shigeyoshi 
Published: May 2006

Abstract
35Cl NQR spectra of N,N-dichloromethane- and N,N,p-trichlorobenzenesulfonamide were measured at liquid nitrogen temperature. The former compound showed a single absorption line at 53.570 MHz, while the latter three lines at 52.405, 52.041 and 35.529 MHz. The bond ionicities estimated from 35Cl NQR frequencies for these compounds were related to the yields of the addition reaction to 2-chlorobutadiene.
Effects of Zinc(II) on Fluorescence Properties of Divalent Europium–Poly(Methacrylate Containing 15-crown-5 Structure) Complex
Authors: Higashiyama Nobuyuki , Adachi Gin-ya 
Published: May 2006

Abstract
The Eu2+-Zn2+-poly(methacrylate containing 15-crown-5 structure) complex excited by U.V. light was found to yield bright blue emission. Its emission intensity was observed to be ca. 50% of that for CaWO4:Pb (NBS1026), while the emission intensity for Eu2+-poly(methacrylate containing 15-crown-5 structure) was ca. 20%. The luminescence lifetime gets much longer by virtue of the Zn2+ coexistence. This Eu2+-Zn2+-polymer complex will be a new promising blue phosphor.
Convenient Synthesis and Dichroic Properties of Heterocyclic Quinone Dyes, 3-(Dialkylamino)benzo[b]naphtho[2,3-d]furan-6,11-diones
Authors: Yoshida Katsuhira , Adachi Takako , Oga Norio , Kubo Yuji 
Published: May 2006

Abstract
New heterocyclic quinone dyes, 3-(dialkylamino)benzo[b]naphtho[2,3-d]furan-6,11-diones, were conveniently prepared from 1,4-naphthoquinone and m-(dialkylamino)phenols. These dyes show dichroic properties and good solubility in a nematic liquid crystalline system.
Preparation, Characterization, and Intercalation of (PbS)(TS2)2; (T = Ti, Nb, Ta), New Ternary Sulfides with Layered Composite Crystal Structure
Authors: Gotoh Yoshito , Akimoto Junji , Sakurai Makoto , Kiyozumi Yoshimichi , Suzuki Kunio , Oosawa Yoshinao 
Published: May 2006

Abstract
A few (PbS)(TS2)2; (T = Ti, Nb, Ta) type of ternary sulfides has been prepared. On the basis of powder X-ray diffraction, it is suggested that they have layered composite crystal structure in which a two-atom-thick PbS layer and two adjacent three-atom-thick TS2 sandwiches are stacked alternately. Intercalation of hydrazine into the sulfides has been observed.
Tetraaminoanthraquinones. New Donor for CT Complexes with Electric Conductivity
Authors: Matsuoka Masaru , Oka Hidetaka , Kitao Teijiro 
Published: May 2006

Abstract
Tetraaminoanthraquinones are found to be a novel electron donor to form intermolecular charge-transfer (CT) complexes with various acceptors. They show electric conductivity of 10−3–20 S cm−1 and are semiconductors.
Absolute Configuration of Sipholenol-A. Presence of Two Conformers of MTPA Ester Moiety in a Crystalline State
Authors: Inouye Yoshinobu , Ohtani Ikuko , Kusumi Takenori , Kashman Yoel , Kakisawa Hiroshi 
Published: May 2006

Abstract
Absolute configuration of sipholenol-A was established as (4S) by a single crystal X-ray analysis of its (S)-(−)-MTPA ester. Two conformers of the MTPA ester moiety were recognized as an occupancy of 0.5:0.5 in crystalline state; the positions of the groups can be rationalized by van der Waals interactions to nearest molecules.
The Utility of 2′-Thp Group in the Synthesis of the Relatively Long RNA Fragments on the Solid Phase
Authors: Tanimura Hiroshi , Imada Takashi 
Published: May 2006

Abstract
The stability of 2′-O-tetrahydropyranyl (Thp) group during several acidic treatments used for removal of 5′-O-9-(4-methoxy)phenyl xanthenyl (Mox) group in synthesis of 30 nucleotide long uridine molecules on the solid supports via cyanoethylphosphoramidite method is discussed.
Novel and Selective Enzymatic Hydrolysis of γ-Ester of Dimethyl α-Dehydroglutamate with α-Chymotrypsin A
Authors: Shin Chung-gi , Seki Masashi , Takahashi Nobuyuki 
Published: May 2006

Abstract
Selective enzymatic hydrolysis of γ-ester of Cbz–ΔGlu (OMe)–OMe with α-chymotrypsin at pH 9 was readily achieved to give the corresponding α-half ester (Cbz–ΔGlu–OMe) along with a small amount of Cbz–ΔGlu(OMe)–OH and Cbz–ΔGlu–OH.
Synthesis of 4,5-Ethylenedithio-4′,5′-(2-oxatrimethylenedithio)tetrathiafulvalene (EOTT) and Electrical Conductivities of Their Ion-Radical Salts
Authors: Nakano Hideyuki , Yamada Kazuyori , Nogami Takashi , Shirota Yasuhiko , Miyamoto Akihito , Kobayashi Hayao 
Published: May 2006

Abstract
The title molecule (EOTT), which is a new unsymmetrical TTF derivative, was synthesized, and several ion-radical salts of EOTT were prepared by electrochemical crystallization. Room temperature conductivities of these salts were found to be in the range of 10−1–102 S cm−1. Among them, EOTT2IBr2 and EOTT2AuI2 showed metallic behavior in electrical conduction down to ca. 15 and 4.2 K, respectively.
Marbling with Amphiphilic Molecules on the Electron Microscopic Scale
Authors: Iriyama Keiji , Araki Toshinari , Tanaka Akira , Iwasaki Takashi 
Published: May 2006

Abstract
Electron microscopic technique allowed the visualization of a pattern in a monolayer similar to that in marbling with Chinese ink on the electron microscopic scale. On the basis of the visualized pattern, the origin of structural defects in a monolayer was speculated.
Electron Microscopic Evidence for the Preparation of Langmuir–Blodgett Film Systems without Any Micro-Pores
Authors: Iriyama Keiji , Tanaka Akira , Araki Toshinari , Yokoi Sei-ichi , Shimada Naoki , Shimada Shigeru , Iwasaki Takashi 
Published: May 2006

Abstract
Electron microscopic examinations of Langmuir–Blodgett film structure were able to help the preparation of the film systems without any micro-pores on the electron microscopic scale.
Direct Oxidation of Silicon Substrates Using ArF Excimer Laser Photolysis of N2O at Low Temperatures
Authors: Tsuji Masaharu , Sakumoto Minoru , Obase Hiroshi , Nishimura Yukio 
Published: May 2006

Abstract
Silicon has been directly oxidized by using oxygen atoms produced from an ArF excimer laser photolysis of N2O. Uniform Si2O films with a thickness of &lt; 130 Å were grown at the substrate temperature range of 30–500 °C and a laser power of about 150 mJ. The dependence of the film thickness on the laser shots, the substrate temperature, and the N2O pressure was examined.
Acid-Catalyzed One-Electron Reduction of Nitrite to Nitric Oxide by an NADH Analog and 1,1′-Dimethylferrocene in the Absence and Presence of Dioxygen
Authors: Fukuzumi Shunichi , Yorisue Tomohiro 
Published: May 2006

Abstract
One-electron reduction of nitrite to nitric oxide proceeds efficiently by an acid-stable NADH analog, 9,10-dihydro-10-methylacridine (two-electron reductant) as well as 1,1′-dimethylferrocene (one-electron reductant) in the presence of perchloric acid in acetonitrile. The effects of dioxygen on both the one-electron and two-electron reductant systems are compared.
Oxidation of Silicon Substrates in the Flowing Afterglow by Using O2, N2O, and H2O
Authors: Tsuji Masaharu , Sakumoto Minoru , Fujii Yuichi , Obase Hiroshi , Nishimura Yukio 
Published: May 2006

Abstract
Silicon was directly oxidized by using O atoms and OH radicals produced from the Ar afterglow reactions of O2, N2O and H2O at substrate temperatures below 350 °C. Uniform thin SiO2 films were grown in all cases. The maximum film thickness was limited to about 20 Å by diffusion of oxidation species across the grown film.
Thermal Reactions of Xylenes in a Temperature Gradient System
Authors: Kawakami Shigenobu , Iwaki Shingo , Yu Aiming , Nakada Masashiro , Yamaguchi Tatsuaki 
Published: May 2006

Abstract
4,4′-Dimethylbibenzyl was produced in high yield with [2.2]paracyclophane and toluene as by-products by the dehydrogenative coupling of p-xylene under a temperature gradient system, i.e., the thermal diffusion reactor. The results were different from those by the conventional tube reactors where far less selectivity for 4,4′-dimethylbibenzyl was obtained.
Amphoteric Redox Nature of p-Benzoquinones with Donor- and Acceptor-Substituents
Authors: Kitagawa Toshikazu , Toyoda Jiro , Nakasuji Kazuhiro , Yamamoto Hiroshi , Murata Ichiro 
Published: May 2006

Abstract
The redox potentials of sixteen substituted p-benzoquinones were measured by cyclic voltammetry. In addition to the first and the second reduction potentials, the first oxidation potential showed linear dependence on Σ(σm + σp)/2 Hammett constant for a wide range of substituents.
Bacteria-Like Fixation of Carbon Dioxide under UV-Light Irradiation with Defect-Free ZnS Quantum Crystallites
Authors: Kanemoto Masashi , Shiragami Tsutomu , Pac Chyongjin , Yanagida Shozo 
Published: May 2006

Abstract
Photoreduction of CO2 to formic acid and a small quantity of CO can be achieved effectively in water by using defect-free ZnS quantum crystallites and their aggregates as catalysts and S2− and H2PO2− ions as sacrificial electron donors under &gt;290-nm irradiation.
Unusual Copper Salt Promoted Addition Reactions of Cyclic 1,3-Dicarbonylmethanides to Olefinic Bonds
Authors: Ogawa Takuji , Hayami Kazuo , Iyama Hironobu , Suzuki Hitomi 
Published: May 2006

Abstract
Carbanions derived from cyclic 1,3-dicarbonyl compounds reacted smoothly with some vinyl bromides and 1,3-enones in HMPA in the presence of copper(I) iodide to give geminally disubstituted alkanes in good yields. The products were easily dehydrated intramolecularly to form 4H-pyran derivatives almost quantitatively.
The Effect of a Direct Dye on the Formation Process of the Structure of Bacterial Cellulose
Authors: Kai Akira , Kido Hiroyasu , Ishida Norikazu 
Published: May 2006

Abstract
It was found that the structure of cellulose obtained from the Acetobacter-culture in the presence of the direct dye of cellulose is fixed in a priori by the structure of a dye. The product from the culture with a direct red 80 formed the cellulose II, and it, from culture with a congo red formed the cellulose IV.
A Novel Ultra-thin Cation-exchange Membrane Prepared by Plasma Polymerization
Authors: Ogumi Zempachi , Uchimoto Yoshiharu , Yasuda Kazuaki , Takehara Zen-ichiro 
Published: May 2006

Abstract
An ultra-thin membrane containing sulfonic ester group was prepared by plasma polymerization of methyl benzenesulfonate and 1,3-butadiene. The sulfonic ester group of the plasma polymer was transformed to lithium sulfonate group by treatment with lithium iodide. The resultant ultra-thin cation exchange membrane was about 0.2 μm thick and pinhole-free, and showed high K+ ion transference number of 0.92 in the aqueous KCl system and resistance of 1.3 Ωcm2.
Convenient Syntheses of Oligoribonucleotides Having 2′-5′ and/or 3′-5′ Phosphodiester Linkage
Authors: Ozaki Hiroaki , Nakamoto Akio , Shimidzu Takeo 
Published: May 2006

Abstract
Sequence-defined Oligoribonucleotides having 2′-5′ and/or 3′-5′ phosphodiester linkage have been synthesized by use of 5′-protected ribonucleoside 2′,3′-cyclic phosphoramidite on solid support. In coupling reaction, pKa of azole as a catalyst governs the activation. The resulting 2′-5′ and/or 3′-5′ linked Oligoribonucleotides were easily separated by reversed-phase chromatography.
Asymmetric Hydrosilylation of Cyclopentadiene and Styrene with Chlorosilanes Catalyzed by Palladium Complexes of Chiral (β-N-Sulfonylaminoalkyl)phosphines
Authors: Okada Toshimi , Morimoto Toshiaki , Achiwa Kazuo 
Published: May 2006

Abstract
It was found that the palladium complexes of newly prepared chiral (β-aminoalkyl)phosphine derivatives bearing N-sulfonyl groups were efficient catalysts for asymmetric hydrosilylations of cyclopentadiene and styrene with chlorosilanes.
Plasma, salivary and urinary cotinine in non-smoker Italian women exposed and unexposed to environmental tobacco smoking (SEASD study)
Authors: Simoni Marzia , Baldacci Sandra , Puntoni Roberto , Pistelli Francesco , Farchi Sara , Presti Elena Lo , Pistelli Riccardo , Corbo Giuseppe , Agabiti Nerina , Basso Salvatore , Matteelli Gabriella , Di Pede Francesco , Carrozzi Laura , Forastiere Francesco , Viegi Giovanni 
Published: May 2006

Abstract
An outline and map of the potential natural vegetation of Ireland
Authors: Cross J.R. 
Published: May 2006

Abstract. A map of the potential natural vegetation of Ireland with an outline description of the vegetation units is presented. The vegetation of Ireland has a distinctive and highly oceanic character as a result of its location on the northwestern extremity of the Eurasian landmass and its recent geological and vegetation history. Forests would naturally cover the greater part of the island but the long history of forest decline over the last 6000 yr, due to clearance by man and paludification, has led to the present situation where native forest cover is less than 1 % of the land area. Together with intensive land use, drainage, peat cutting and the introduction of alien species, this presents considerable difficulties in the construction of mapping units.The map, which has been compiled as part of the Vegetation Map of Europe at a scale of 1 : 2.5 million, contains 20 mapping units. They comprise: nine forests, i.e. montane birch forests (one unit), acidophilous oak forests (two units), forests of oak or oak and ash with hazel on mostly base‐rich soils (four units), forests on alluvium and gleyed clays (one unit each); five mire types, i.e. blanket mires (two units), raised bogs (one unit), sedge mires (one unit), degraded raised bogs (one unit); and six minor units viz. heaths (two units), sand dunes (two units), salt marshes (one unit) and polders (one unit). As a result of human activity, the potential natural vegetation, especially the forests, will differ considerably from the former natural climax vegetation.
Conservation of bog plant species assemblages: Assessing the role of natural remnants in mined sites
Authors: Poulin Monique , Rochefort Line , Desrochers André 
Published: May 2006

Abstract. Bogs, economically valuable wetlands, are subjected to exploitation in southern Canada. We addressed plant conservation within bogs mined for peat, in which small undisturbed remnants are left, mostly at the margins of the mined areas. The main goal of the study was to test whether these remnants act as refuges for plants which could recolonize areas that are planned for restoration after mining is completed.Mosses, lichens and vascular plants were sampled in remnants of 24 mined bogs in southeastern Canada during the summer of 1997. The vegetation was also sampled at the margins and centres of 24 nearby natural bogs in plots similar in size to these remnants. Using similarity analysis and ordination techniques, we found that plant species assemblages in remnants of mined bogs differ from those near the margins of natural bogs, and that certain species are associated with the centre of natural bogs, due to the presence of pools. We also showed that water conditions of remnants are affected by drainage due to peat mining. Sphagnum moss showed itself to be a key indicator of mining effects on vegetation. Implications for peat resource management and bog conservation are discussed.
Determinants of floristic diversity and vegetation composition on the islands of Lake Burollos, Egypt
Authors: Khedr Abdel‐Hamid , Lovett‐Doust Jon 
Published: May 2006

Abstract. A floristic and environmental survey was carried out on 22 uninhabited islands (0.1‐8.4 ha) in Lake Burollos, Egypt. A total of 58 vascular plant species was recorded. The number of habitats on each island was counted. There was a positive correlation between island area and number of habitat types. Island area was significantly positively correlated with various measures of floristic diversity, including the total number of species present, and the numbers of annual, herbaceous, and shrublet species. Perennial and shrub species numbers did not differ significantly with island area. In addition to island area, elevation and soil salinity, as well as distance to the Mediterranean Sea, all contributed significantly to variation in species composition in the terrestrial habitats. Water salinity and transparency accounted for 69% of the variation in aquatic species numbers. There was a weak effect of isolation on similarity of species composition on islands.Eight vegetation types, represented by 13 indicator species identified after TWINSPAN analysis, were distinguished by soil characteristics. Species richness was inversely correlated with clay, organic carbon and total nitrogen in the soil, but positively correlated with calcium carbonate content.From a management perspective, long‐term monitoring of threatened habitats in the lake is urgently required as a starting point to preserve biodiversity. Finally, we conclude that the present study supports the hypothesis indicating that larger areas feature higher species richness due to increased numbers of habitats.