bluuebunny/crossref_metadata_2025 huggingface dataset:
Hormonal Profile of Women with Self-Reported Symptoms of Oligomenorrhea and/or Hirsutism: Northern Finland Birth Cohort 1966 Study
Authors: Taponen Saara , Martikainen Hannu , Järvelin Marjo-Riitta , Laitinen Jaana , Pouta Anneli , Hartikainen Anna-Liisa , Sovio Ulla , McCarthy Mark I. , Franks Stephen , Ruokonen Aimo
Published: January 2003

The hormonal profiles of nested female patients (n = 500) with self-reported symptoms typical of polycystic ovary syndrome (PCOS), oligomenorrhea, and/or hirsutism and their randomly selected controls (n = 1026) at the age of 31 yr were analyzed in a general population-based Northern Finland birth cohort 1966 to find out whether the symptomatic women also have the endocrine characteristics of PCOS and could be detected in a general population using simple questions. Higher medians of serum testosterone (T) (2.10 vs. 1.90 nmol/liter, P < 0.001), LH (5.40 vs. 4.85 U/liter, P = 0.005), insulin (53.8 vs. 51.66 pmol/liter, P = 0.040), and free androgen index (FAI) (4.01 vs. 3.03, P < 0.001) and lower glucose/insulin ratio (91.1 × 108vs. 94.9 × 108, P = 0.048) and SHBG (52.4 vs. 60.7 nmol/liter, P < 0.001) were observed among the cases, but no difference was observed in cortisol and glucose levels between the cases and controls. Of all the women in the cohort, 10.2% reported only oligomenorrhea and had biochemical findings similar to the whole case group. Those who reported only hirsutism (10.4%) were in between the case and control groups according to biochemical findings. The subjects who reported both oligomenorrhea and hirsutism (3.4%) had the highest T, LH, FAI, insulin, and glucose and the lowest SHBG and glucose/insulin ratio, compared with the case group and the groups with either symptom only indicating a dose-response manner in typical endocrine profile of PCOS by adding up symptoms. The levels of T and FAI were higher and SHBG lower in groups with overweight or obesity both at 14 and 31 yr, compared with groups with normal weight at 14 yr and overweight or obesity at 31 yr. In the group with normal weight at 14 and 31 yr and the group with overweight or obesity at 14 yr but normal weight at 31 yr, the levels of T and FAI were lowest and SHBG highest. T and FAI were higher and SHBG lower among the cases than the controls in groups stratified by weight development from adolescence to adulthood. In conclusion, this longitudinal study of a large, stable population indicates that women with self-reported symptoms of hirsutism and/or oligomenorrhea show endocrine characteristics of PCOS and can be detected in a general population using simple questions. These symptoms are markers of the underlying metabolic alterations possibly associated with increased health risks in later life.
Purification and Characterization of a Novel Intracellular 17β-Estradiol Binding Protein in Estrogen-Resistant New World Primate Cells
Authors: Chen Hong , Hu Bing , Huang Gang-Hua , Trainor Amanda G. , Abbott David H. , Adams John S.
Published: January 2003

Compared to Old World primates, including man, New World primates display target-tissue resistance to gonadal steroid hormones. In female New World primates this resistant phenotype is characterized by elevated concentrations of plasma estradiol and progesterone. Here we describe the discovery of an intracellular estrogen binding protein (IEBP) that acts to concentrate 17β-estradiol (E2) in the cytoplasm of New World primate target cells. IEBP was purified by E2-affinity chromatography from postnuclear extracts of the B95-8 cells established from an E2-resistant New World primate. Compared with unpurified extract, affinity-purified IEBP demonstrated a 300-fold enrichment in specific E2 binding activity; half-maximal displacement of[ 3H]E2 from affinity-purified IEBP was observed with 0.1 nM E2. Affinity-purified extracts were subjected to SDS-PAGE with isolation of a dominant 27-28 kDa protein. N-terminal sequencing of tryptic peptides of the protein showed sequence homology with human heat shock protein-27 (hsp27). By immunoblot and E2 binding capacity, IEBP was 1] 2–3-fold greater in New World than in Old World primate tissues and cell lines, 2] heat-inducible and 3] up-regulated in vivo in the presence of the functioning female gonad. In conclusion, IEBP is a specific E2-interacting heat shock protein in the hsp-27 family that is relatively overexpressed in estrogen-resistant cells.
Elasto-multi-body dynamics of a multicylinder internal combustion engine
Authors: Kushwaha M , Gupta S , Kelly P , Rahnejat H
Published: January 2003

This paper presents a multi-body model of a four-cylinder, four-stroke diesel engine, incorporating component flexibility. The model also includes engine firing order and experimentally measured combustion time history. The paper presents numerical predictions for conical motion of the flywheel as a result of combined torsion-deflection modes of the flexible crankshaft system. The half-engine order responses induce complex three-dimensional whirling motion of the flywheel, which is responsible for repetitive shock loading of the drivetrain system through impact with the clutch system. This leads to an assortment of noise and vibration concerns, one of which is in-cycle vibration of the clutch system. Numerical prediction of this vibration response agrees well with experimental findings.
Influence of preview uncertainties in the preview control of vehicle suspensions
Authors: Vahidi A , Eskandarian A
Published: January 2003

Active control of vehicle suspensions has long been known as an effective way of enhancing isolation of unwanted vibrations. It is further shown in the literature that obtaining ‘preview’ information of the ‘future’ road inputs will result in smoother control with less control effort. Most of these studies assume perfect preview measurements. This paper is a simulation analysis to verify if the benefits of preview are valid in the presence of uncertainty. The optimal control scheme for preview control of a quarter-car suspension model is briefly presented, followed by numerical simulations. The analysis addresses two different possible sources of uncertainty in preview measurements. Comparison of the performance for various levels of uncertainty in the preview shows that noise/uncertainty can be an issue, with an adverse effect that sometimes increases with preview length. In other words, it is shown that controllers with longer preview can be more susceptible to noise. However, the limits of tolerable noise are not very restrictive, and the well-known benefits of preview can still be achieved if the measurement errors are maintained below a limited level.
A case study of the rolling contact of a calendar roll
Authors: Jårvenpåå V-M , Yuan L , Keskinen E
Published: January 2003

The rolling contact of a case study is discussed. A method for describing the contact of the two rolls of a calender unit is presented. Firstly, the rotor dynamics system of a roll is described by expressing the kinetic energy in a global non-rotating coordinate frame and the strain energy in a rotating frame by using a finite element (FE) mesh and then by deriving the rotor dynamical matrix equations accordingly. The contact of the two rolls is then defined as a line contact moving on the roll surfaces according to the rotation movements. A procedure for determining the movement on the surface of FE mesh is presented. The contact stiffness function between the rolls is described. The aim of this study is to create a cost effective simulation approach for numerical time domain analyses. An example simulation is illustrated.
Dynamic interaction of vehicles moving on uniform bridges
Authors: Jalili N , Esmailzadeh E
Published: January 2003

The dynamic interaction problem of moving vehicles on uniform suspension bridges is studied. The resulting variable moving loads acting on the bridge are of great practical importance to both bridge and automotive engineers. The vehicle, including the occupants, is modelled as a planar half-car with six degrees of freedom, and the bridge is assumed to obey the Euler-Bernoulli beam theory with arbitrary conventional boundary conditions. However, the numerical simulations presented here are for the case of a vehicle travelling at a constant speed on a bridge with simply supported end conditions. Owing to the continuously moving location of the loads on the bridge, the governing differential equations will have time-varying coefficients and hence become rather complicated. The relationship between the bridge vibration characteristics and the vehicle speed is established, resulting in a search for a particular speed that determines the maximum values of dynamic deflection and the bending moment of the bridge.
Enhancement of an Anodic Photocurrent for Polymer Langmuir–Blodgett Monolayer Containing Tris(2,2′-bipyridine)ruthenium Complex by Surface Plasmon Excitation
Authors: Fukuda Nobuko , Mitsuishi Masaya , Aoki Atsushi , Miyashita Tokuji
Published: January 2003

An anodic photocurrent due to photoinduced electron transfer between excited Ru(bpy)32+ and triethanolamine was remarkably enhanced by light irradiation using the surface plasmon resonance on a silver electrode which was modified by amphiphilic copolymer Langmuir–Blodgett monolayer containing Ru(bpy)32+ compared with irradiation of transmitted light.
Convenient Synthesis of a Central 2,3,6-Trisubstituted Pyridine Skeleton of a Macrobicyclic Antibiotic, Cyclothiazomycin
Authors: Okabe Akihiro , Ito Akinori , Okumura Kazuo , Shin Chung-gi
Published: January 2003

The first convenient synthesis of the main central 2,3,6-trisubstituted pyridine skeleton [protected Fragment A-B] of a macrobicyclic antibiotic, cyclothiazomycin, was achieved.
Application of Thiouronium Derivatives as Anion Ionophores for Ion Selective Electrodes
Authors: Sasaki Shin-ichi , Hashizume Akio , Ozawa Satoru , Citterio Daniel , Iwasawa Naoko , Suzuki Koji
Published: January 2003

Novel anion ionophores based on thiouronium derivatives were synthesized, and their application to ion selective electrodes (ISEs) was examined. The electrodes clearly exhibited an anti-Hofmeister selectivity pattern with enhanced selectivity for the iodide anion.
Properties of Photoexcited States of C180, a Triangle Trimer of C60
Authors: Fujitsuka Mamoru , Fujiwara Koichi , Murata Yasujiro , Uemura Shinobu , Kunitake Masashi , Ito Osamu , Komatsu Koichi
Published: January 2003

Photophysical properties of C180 “cis-2/cis-2/cis-2”, a triangle triad of C60, were investigated by various methods including a transient absorption spectroscopy. Fluorescence and triplet absorption spectra were similar to those of C120 (C60 dimer) and other 1, 2-adducts of C60. On the other hand, short fluorescence lifetime and small quantum yield for the intersystem crossing process indicate that the photophysical properties of C180 are affected by the non-radiative process in the singlet excited state.
The Ruthenium-Catalyzed Addition of β C–H Bonds in Aldehydes to Olefins
Authors: Kakiuchi Fumitoshi , Sato Taisuke , Igi Kimitaka , Chatani Naoto , Murai Shinji
Published: January 2003

The addition of a β C–H bond to the formyl group of aldehydes to olefins took place with the aid of Ru(H)2(CO)(PPh3)3 as a catalyst. Several olefins can be used in the catalytic reaction of conjugate enals. The presence of a sterically hindered substituent at the ortho position of benzaldehyde and the presence of an electron donating substituent appear to be important factor in accomplishing the desired coupling reaction.
Oxidation of Various Secondary Amines to Imines with N-tert-Butylphenylsulfinimidoyl Chloride
Authors: Mukaiyama Teruaki , Kawana Asahi , Fukuda Yoshio , Matsuo Jun-ichi
Published: January 2003

Various secondary amines were smoothly oxidized to the corresponding imines at −78 °C by using N-tert-butylphenylsulfinimidoyl chloride and DBU.
Highly Durable Enantio-Differentiating Nickel Catalyst for Repeated Use for the Hydrogenation of Methyl Acetoacetate
Authors: Osawa Tsutomu , Sakai Saori , Harada Tadao , Takayasu Osamu
Published: January 2003

The enantio-differentiating hydrogenation of methyl acetoacetate was repeated 30 times over a fine Ni powder catalyst while modifiers (optically active tartaric acid and NaBr) were directly added to the reaction media only in the first run. Over 80% optical yields were attained for the repeated runs. The addition of sodium 2-ethylhexanoate increased the optical yields in the subsequent runs. The very simple and highly durable enantio-differentiating nickel catalyst for repeated use was developed by an in situ modification.
Preparation of CdS Semiconductor Nanowire by a Convenient Ultraviolet Irradiation Technique
Authors: Wu Shuang-Ding , Zhu Zhengang , Tan Jingyun , Gao Junchang
Published: January 2003

Cadmium sulfide (CdS) nanowire was synthesized by a convenient ultraviolet irradiation method using hydroxyethyl cellulose as a soft template at room temperature.
A Simple Alcohothermal Synthetic Route to High Surface Area Zirconia Aerogel
Authors: Hu Juncheng , Cao Yong , Deng Jingfa
Published: January 2003

A novel alcohothermal process has been successfully developed to prepare the thermally stable tetragonal zirconia aerogel using a cheap inorganic salt as the starting material. The results showed that the as-prepared zirconia aerogel has a high surface area and a well-developed textural mesoporosity, which is highly attractive for potential applications in heterogeneous catalysis.
Stereo- and Regioselective Opening of 3-Phenylglycidates by Trifluoromethylsulfonamide under Solid–Liquid Heterogeneous Conditions
Authors: Penso Michele , Albanese Domenico , Landini Dario , Lupi Vittoria
Published: January 2003

Ethyl cis- and trans-3-phenylglycidates have been opened stereo- and regioselectively with trifluoromethylsulfonamide in the presence of catalytic amounts of solid sodium carbonate. Under these conditions, (2R,3R)-3-phenylglycidate produces exclusively ethyl (2R,3S)-3-N(trifluoromethanesulfonyl)amino-2-hydroxy-3-phenylpropionate deriving from the attack of the nucleophile on the C-3 carbon atom.
Spectroscopic Properties of Noble Metal Nano-Particles Covered with J-Aggregates of Cyanine Dye
Authors: Sato Tomoo , Tsugawa Fusahiro , Tomita Toshinori , Kawasaki Mitsuo
Published: January 2003

We have found, for the first time, a unique spectroscopic property of noble metal nano-particles (colloidal silver in solution or noble metal island film) covered with a J-aggregate monolayer. The spectral dip or hole at the position of the J-band was observed in the surface plasmon band. The appearance of the hole was related to the interaction between the surface plasmon of the noble metal nano-particles and the Frenkel exciton of the J-aggregate.
Furfural Hydrogenation to Furfuryl Alcohol over a Novel Ni–Co–B Amorphous Alloy Catalyst
Authors: Luo Hongshan , Li Hexing , Zhuang Li
Published: January 2003

The ultrafine Ni–Co–B amorphous catalysts were employed in liquid-phase furfural hydrogenation, which showed higher activity and better selectivity to furfuryl alcohol than either Ni–B, or Co–B, or the mixture of Ni–B and Co–B catalysts. The promoting effect of Co-dopant was briefly discussed.
A Novel Electron Beam-Induced Reaction of Sulfonium Salt in the Crystalline State
Authors: Moon Seongyun , Maekawa Yasunari , Yoshida Masaru
Published: January 2003

The electron beam irradiation of triphenylsulfonium methanesulfonate in the crystalline state provides a new benzene-substituted sulfonium salt. This product has not been observed either by photolysis in the crystalline state nor by electron beam irradiation in a solution. The formation of the substitution product was confirmed by GC–MS analysis.
Intermolecular [2+2] Photocycloaddition of Formyl- and Cyano-Substituted Diphenylhexatrienes in the Solid State
Authors: Sonoda Yoriko , Miyazawa Akira , Hayashi Shigenobu , Sakuragi Masako
Published: January 2003

Crystalline powder of all-trans-1,6-bis(4-R-phenyl)-1,3,5-hexatriene (R = CHO and CN) underwent intermolecular [2+2] photocycloaddition at the 1,2-position of the triene to give mirror symmetric dimers. For the formyl derivative the presence of C–H···O hydrogen bonds was suggested by IR and 13C CP/MAS NMR spectra.
Assembly of Diethylenetriaminepentaacetatocobaltate(III) Complexes on the Surface Lysine Residues of Myoglobin
Authors: Tsukahara Keiichi , Nishimine Mari , Kiguchi Kimiko , Shioyama Yuka , Matsui Miho , Kubota Naoko , Arakawa Ryuichi
Published: January 2003

Myoglobin, whose lysine residues are linked with diethylenetriaminepentaacetatocobaltate(III) complexes, was prepared and characterized.
Hydrogen Atom Transfer of 5-Hydroxyflavone in the Excited Triplet State
Authors: Norikane Yasuo , Arai Tatsuo
Published: January 2003

Behavior of 5-hydroxyflavone (5HF) in the excited triplet state was studied for the first time by transient absorption and phosphorescence spectroscopies. 5HF underwent the intramolecular hydrogen atom transfer in the excited triplet state at room temperature.
Kinetic Evidence for the Hydrophobic Atmosphere of the Catalytic Cavity in Carboxypeptidase Y Based on a Linear Relationship between Michaelis–Menten Constant Km and Hydrophobicity of the Substrates
Authors: Kanosue Yoshifumi , Hiraga Yoshikazu , Kojima Satoshi , Ohkata Katsuo
Published: January 2003

In the hydrolysis of several dipeptides by carboxypeptidase-Y (CPD-Y), there was found a good linear relationship (r = 0.999) between Michaelis–Menten constant Km and hydrophobicity of the substrates evaluated as relative elution volume in reversed-phase HPLC.
Ruthenium-Catalyzed Dehydrogenative Silylation of Aryloxazolines with Hydrosilanes via C–H Bond Cleavage
Authors: Kakiuchi Fumitoshi , Igi Kimitaka , Matsumoto Mitsutaka , Chatani Naoto , Murai Shinji
Published: January 2003

The reaction of aryloxazolines with trialkylhydrosilanes using Ru3(CO)12 or Ru(H)2(CO)(PPh3)3 complex as a catalyst resulted in dehydrogenative silylation to form ortho silylated aryloxazolines in good to excellent yields. This reaction can be applied to aryloxazolines having either electron-donating (Nme2, Ome, and CH3) or -withdrawing (CF3 and F) groups.
A Catalytic and Stereoselective Glycosylation with Glucopyranosyl Fluoride by Using Various Protic Acids
Authors: Jona Hideki , Mandai Hiroki , Mukaiyama Teruaki
Published: January 2003

A catalytic and stereoselective glycosylation with glucosyl fluoride was effectively performed by using a catalytic amount of various protic acids. When the glycosylation was carried out, for example, using perchloric acid (HClO4) in diethyl ether (Et2O), the major products were α-glycosides while β-stereoselectivity was observed when tetrakis(pentafluorophenyl)boric acid [HB(C6F5)4] was used in a mixed solvent of trifluoromethylbenzene (BTF)–pivalonitrile (tBuCN) = (5:1). The stereoselectivity was controlled by not only the effect of solvent but also by the nature of counter anion of the catalyst such as B(C6F5)4− or ClO4−.
Yb(Otf)3·H2O: A Novel Reagent for the Chemoselective Hydrolysis of Isopropylidene Acetals
Authors: Yadav J S , Reddy B V Subba , Reddy K Srinivasa
Published: January 2003

A facile chemoselective hydrolysis of terminal isopropylidene acetals has been achieved using a catalytic amount of Yb(Otf)3·H2O in acetonitrile at ambient temperature.
A Novel Route to Prepare Nano-Hg2Cl2 Arrays
Authors: Wang Yinhai , Mo Jimei , Cai Weili , Yao Lianzeng , Zhang Lide
Published: January 2003

Recently, we find a novel route to prepare nano-Hg2Cl2 in the pores of alumina membrane. To the best of our knowledge, it is first time for preparing nano-Hg2Cl2 arrays. The nano-Hg2Cl2 has a potential application as nanoelectrode.
Photoswitching of Intramolecular Magnetic Interaction Using Photochromic Diarylethene Spin Coupler: Introduction of Thiophene Spacer
Authors: Matsuda Kenji , Matsuo Mitsuyoshi , Irie Masahiro
Published: January 2003

Photochromic 1,2-bis(2-methyl-1-benzothiophen-3-yl)perfluorocyclopentene having two nitronyl nitroxide radicals with a thiophene-2,5-diyl spacer was prepared and the intramolecular magnetic interaction was compared with the derivative having the radicals with a p-phenylene spacer. The stronger magnetic interaction was observed for the compound with the thiophene spacer.
Highly Thermostable Liposome from 72-Membered Macrocyclic Tetraether Lipid: Importance of 72-Membered Lipid for Archaea to Thrive under Hyperthermal Environments
Authors: Arakawa Kenji , Eguchi Tadashi , Kakinuma Katsumi
Published: January 2003

The thermostability of liposomes comprising from a 1:1 mixture of archaeal 72-membered macrocyclic tetraether diphospholipids was investigated for the first time in comparison with those of acyclic and 36-membered macrocyclic diether phospholipids. The liposomes of the former 72-membered macrocyclic lipid certainly form thermostable liposomes.
Improved Yield of Enzyme Reaction in Microchannel Reactor
Authors: Miyazaki Masaya , Nakamura Hiroyuki , Maeda Hideaki
Published: January 2003

Trypsin-catalyzed hydrolysis of benzoylarginine-p-nitroanilide using a microchanel reactor showed higher yield than batchwise reaction at lower enzyme concentration. The rate of reaction seemed to be 20 times greater than that in the batchwise system.
Palladium-Catalyzed Benzannulation of Conjugated Enynes in Fluorous Biphasic System
Authors: Saito Shinichi , Chounan Yukiyasu , Nogami Tsutomu , Ohmori Osamu , Yamamoto Yoshinori
Published: January 2003

We carried out the benzannulation (cyclodimerization) of conjugated enynes in fluorous biphasic system in the presence of perfluoro-tagged palladium catalyst and succeeded in reusing the catalyst for several times.
Extraordinary High Tetravalent Cation Conducting Behaviors in Solid
Authors: Imanaka Nobuhito , Ueda Tomohiro , Adachi Gin-ya
Published: January 2003

A tetravalent cation conductor whose ionic conductivity is extraordinary high and comparable to the conductivity range of the representative divalent oxide anion conductors, was artificially designed by strictly choosing the constituent elements and the structure of the solid. Promising applications such as rechargeable batteries and chemical sensors for a global environmental monitoring, are greatly expected.
Photochemical Production of Sugar-like Interconvertible Anomeric Naphthopyranylhemiacetals from Acenaphthylene and Chloranil
Authors: Haga Naoki , Takayanagi Hiroaki , Tokumaru Katsumi
Published: January 2003

Irradiation of acenaphthylene (ACN) and p-chloranil with > 420 nm light in 1,2-dichloroethane gives two interconvertible anomeric naphthopyranylhemiacetals in high yields (> 70%), whereas irradiation of ACN with other 1,4-benzoquinones does not afford this type of products. The above products will result from photochemical formation of an oxetane followed by its hydration. These products are stereoselectively converted into an identical naphthopyranylacetal in primary alcohols.
Fabrication of Nano-rod Copper-polymer Composites by γ-Irradiation Route in a Heterogeneous System
Authors: Ni Yonghong , Ge Xuewu , Liu Huarong , Zhang Zhicheng , Ye Qiang , Wang Feng
Published: January 2003

Nano-rod copper-polymer composites were synthesized by γ-irradiation in a heterogeneous solution system under atmospheric pressure at room temperature. The product was characterized by XRD, TEM and IR spectrum, respectively. The investigation showed that a rather low dose rate of irradiation was necessary in the formation of nano-rod composites.
Oxidized Diamond Supported Ni Catalyst for Synthesis Gas Formation from Methane
Authors: Nakagawa Kiyoharu , Nishimoto Hiroaki , Enoki Yuji , Egashira Sayaka , Ikenaga Na-oki , Kobayashi Tetsuhiko , Nishitani-Gamo Mikka , Ando Toshihiro , Suzuki Toshimitsu
Published: January 2003

Oxidized diamond gave the best performance among the support materials of Ni loaded catalysts for the partial oxidation of methane. Ni(5 wt%)/oxidized diamond afforded 20% conversion of methane (CH4/O2 = 5) to give CO and H2 ratio of 2.0 at 873 K. Ni(5 wt%)/oxidized diamond also showed high catalytic activity for the CO2 reforming of methane.
Removal of Lead from Vermiculite by Using l-Asparaginic-N,N-diacetic Acid, a Novel Biodegradable Chelating Reagent, and Depolymerized Pectic Acid
Authors: Xueyi Guo , Inoue Katsutoshi , Mishima Kenji
Published: January 2003

The removal of lead from vermiculite by means of elution with two kinds of novel chemical reagents l-asparaginic-N,N-diacetic acid and depolymerized pectic acid, was investigated. The effects of contact time, concentration of the reagents and equilibrium pH of solution on elution of lead were examined by batch-wise technique. It was found that both of the reagents are effective for the removal of lead and have the potential application for the remediation of soil polluted by heavy metals.
Titanium-Promoted Cobalt Sulfide Catalysts for NO Decomposition and Reduction by CO
Authors: Zhaoliang Zhang , Jun Ma , Zhaoqong Liu , Shaoling Ren , Xiyao Yang , Yuan Kou
Published: January 2003

Cobalt sulfide and titanium-promoted cobalt sulfides were reported as catalysts for NO decomposition and reduction by CO. Titanium-promoted cobalt sulfides showed not only nearly complete NO removal but the simultaneous catalytic reduction of NO and SO2 by CO to N2 and elemental sulfur, respectively.
An Oxidative Transformation of N′-Phenylhydrazide to t-Butyl Ester Using a Copper(II) Halide–Lithium t-Butoxide System
Authors: Yamaguchi Jun-ichi , Aoyagi Takashi , Fujikura Ryohei , Suyama Takayuki
Published: January 2003

Reactions of hydrazides or N′-phenylhydrazides with a copper(II) reagent prepared from copper(II) bromide and lithium t-butoxide smoothly proceeded to give the corresponding t-butyl ester in high yield.
A Catalytic Asymmetric 1,3-Dipolar Cycloaddition of Nitrones to Allyl Alcohol
Authors: Ding Xia , Taniguchi Katsumi , Ukaji Yutaka , Inomata Katsuhiko
Published: January 2003

A highly diastereo- and enantioselective 1,3-dipolar cycloaddition of nitrones bearing an amide moiety to allyl alcohol has been realized by using a catalytic amount of diisopropyl (R,R)-tartrate as a chiral auxiliary. Addition of amine N-oxide such as pyridine N-oxide, was crucial to realize a reproducible excellent enantioselectivity up to 98% ee.
Styrylpyrylium Derivatives for Second-Order Nonlinear Optics
Authors: Tsuji Kyoko , Okada Shuji , Oikawa Hidetoshi , Matsuda Hiro , Nakanishi Hachiro
Published: January 2003

The first hyperpolarizabilities (β) of styrylpyrylium derivatives were systematically investigated by hyper-Rayleigh scattering experiments and semiempirical calculation in relation to their absorption. They were found to be potential second-order nonlinear optical species covering the longer cutoff-wavelength range compared with the corresponding stilbazolium derivatives.
A Novel Looping Structure of Linear Hexapeptide Boc-[d-Ala-(Z)-β-phenyldehydroalanine-l-Ala]2-OMe
Authors: Inai Yoshihito , Oshikawa Tatsuo , Yamashita Mitsuji , Kato Itsuki , Hirabayashi Tadamichi
Published: January 2003

Hexapeptide Boc-(d-Ala-ΔZPhe-l-Ala)2-OCH3 [Boc = tert-butyloxycarbonyl; ΔZPhe = (Z)-β-phenyldehydroalanine] in the solid state exhibited a novel looping backbone consisting of three partially overlapped β-turns supported by intramolecular (i+3) → i hydrogen bonds. Here the looping backbone also included a β-bend ribbon structure.
Deep Hydrodesulfurization over W-Based Catalysts Supported by Siliceous MCM-41
Authors: Wang Anjie , Li Xiang , Chen Yongying , Han Difei , Wang Yao , Hu Yongkang , Kabe Toshiaki
Published: January 2003

A deep HDS catalyst, exhibiting considerably high activity in desulfurizing dibenzothiophene and a high-sulfur gas oil, was prepared by depositing Ni–W species over siliceous MCM-41.
Synthesis, Structure, and Photochemistry of 2-Silyl- and 2-Disilanyl-2-aryl-1,3-dithiane Derivatives
Authors: Reddy Anugula Mahipal , Tsutsui Shinobu , Sakamoto Kenkichi
Published: January 2003

A series of 2-silyl- and 2-disilanyl-substituted 2-aryl-1,3-dithiane derivatives were prepared by the reactions of 2-aryl-2-lithio-1,3-dithianes with the corresponding chlorosilanes. Photolysis of 2-phenyl-2-(pentamethyldisilanyl)-1,3-dithiane resulted in the intermediary formation of 1,1-dimethyl-2-phenyl-2-(trimethylsilyl)-1-silaethene.
Relationship between the Excited Multiplet EPR and Phosphorescence Lifetime in the Excited Triplet Octaethylporphinatozinc Coordinated by One TEMPO Radical
Authors: Ishii Kazuyuki , Ishizaki Takeo , Kobayashi Nagao
Published: January 2003

by the combined use of time-resolved electron paramagnetic resonance (TREPR) and phosphorescence emissions, two kinds of octaethylporphinatozinc coordinated by an axial ligand containing a nitroxide radical have been investigated.
Enhanced Chemiluminescence of Bis(2,4,6-trichlorophenyl) Oxalate–Hydrogen Peroxide–Dyestuff System in the Presence of Polymer Particles
Authors: Tsukagoshi Kazuhiko , Tomita Yuji , Nakajima Riichiro
Published: January 2003

Chemiluminescence property of bis(2,4,6-trichlorophenyl) oxalate–hydrogen peroxide–dyestuff system was examined in the presence of polymer particles. The chemiluminescence of the system was enhanced through an interaction between xanthene dyestuffs and polymer particles. For example, when using erythrosine B, the chemiluminescence intensity in the presence of the particles was about 20 times larger than that in the absence of them. It was clarified from preliminary experiments that the enhanced chemiluminescence with the particles was useful for the determination of H2O2 and dyestuff-labeled d-glucose.
Synthesis of a Novel Oxotungsten(VI) Complex Having a Chelating Bis(aryloxo) Ligand and Its Catalytic Behavior for Ring-Opening Metathesis Polymerization
Authors: Takashima Yoshinori , Nakayama Yuushou , Harada Akira
Published: January 2003

An oxotungsten complex coordinated with O–S–O chelating bis(aryloxo) ligand, WO{S(4-Me-6-tBuC6H2O)2}Cl2 (1), was synthesized by the reaction of WOCl4 with 2, 2′-S(4-Me-6-tBuC6H2OH)2. The structure of the complex 1 was determined by single-crystal X-ray analysis to have pseudo Cs symmetry. The catalytic behavior of 1/AlEt3 system for the ring-opening metathesis polymerization of norbornene was studied. In this catalytic system, strong dependencies of cis/trans selectivity on the catalyst concentration and on the polymerization temperature were observed. With increasing catalyst concentration and with lowering polymerization temperature, the resulting poly(norbornene)s tend to have higher cis-regularity. Oppositely, trans-rich poly(norbornene)s were produced by the polymerization under low catalyst concentration and at high polymerization temperature. We propose that these observations might come from oxotungsten–aluminum interaction.
Lipase-Catalyzed Hydrolytic Degradation of Polyurethane in Organic Solvent
Authors: Takamoto Tetsufumi , Shirasaka Hitoshi , Uyama Hiroshi , Kobayashi Shiro
Published: January 2003

Hydrolytic degradation of polyurethane has been achieved using lipase as catalyst. The degradation of polyurethane containing an aliphatic polyester chain as soft segment rapidly took place in the presence of Candida antarctica lipase in toluene at 60 °C to give oligomers with molecular weight less than 500.
Synthesis of CuS Millimeter-Scale Tubular Crystals
Authors: Wang Chunrui , Tang Kaibin , Yang Qing , Bin Hai , Shen Guozhen , Qian Yitai
Published: January 2003

CuS millimeter-scale tubular crystals were synthesized for the first time via a hydrothermal method at 185 °C. A possible growth mechanism of CuS tubular crystals was proposed.
A Molecular Pyroelectric Using a Chiral Zinc(II) Complex: High Pyroelectric Coefficient by Second-order Pyroelectricity
Authors: Sakiyama Hiroshi , Ito Tatsuya
Published: January 2003

A chiral zinc complex [Zn(R-salphet)2] [R-salphet− = N-(R)-1-phenylethylsalicylideneiminate(1–)] showed second-order pyroelectricity in a starch matrix. The pyroelectric coefficient was found to be 2.0 ± 1.5 mC m−2 K−1, which is much greater than that of practical pyroelectric materials. The resonance and antiresonance frequencies were found to be 50 kHz and 90 kHz, respectively, from the admittance measurement. The electromechanical coupling factor was calculated to be 0.95.
Peculiar Cycle Behavior of LiAl0.1Mn1.9O4 Material in the 3 V Region
Authors: Lee Yun Sung , Sun Yang Kook , Yoshio Masaki
Published: January 2003

LiAl0.1Mn1.9O4 was synthesized using LiOH, Al(NO3)3, and two different Mn3O4 sources (Tosoh and Chuodenki, Japan). Two LiAl0.1Mn1.9O4 showed similar physicochemical properties, but these presented very different cycle performance in the 3 V region. The ex-situ XRD measurements also revealed that the two materials showed different X-ray patterns after discharge to 2.2 V after 50 cycles. We found new phenomenon that the LiAl0.1Mn1.9O4 materials might show an entirely different cycle behaviors in the 3 V region even if they were synthesized using Mn source of the same crystal structure.
Synthesis of Citronellyl Acetate via a Transacetylation to Citronellol from Acetyl Coenzyme A Produced from Glucose and Acetate in Growing Yeasts
Authors: Oda Shinobu , Sugai Takeshi , Ohta Hiromichi
Published: January 2003

A novel coupling system, which is an acetylation system of primary alcohols with acetyl coenzyme A [acetyl-CoA] formed via the metabolism of glucose and acetate, was developed with Hansenula and Pichia. The supplementation of sodium acetate to glucose as the source of acetyl-CoA was effective to enhance the reaction rate and yield of acetylation of citronellol.
Preparation and Characterization of Regioregular Head-to-Tail π-Conjugated Poly(pyridine-2,5-diyl)s
Authors: Yamamoto Takakazu , Nakamura Takeshi , Fukumoto Hiroki , Kubota Kenji
Published: January 2003

Regioregular head–to-tail π-conjugated polypyridines have been prepared for the first time by organometallic polycondensation using Ni(II) complexes as the catalyst. The proportion of the HT-content in poly(6-hexylpyridine-2,5-diyl) was higher than 95%.
A Novel Strategy for Synthesis of Optically Active Polyanilines in Organic System
Authors: Su Shi-Jian , Kuramoto Noriyuki
Published: January 2003

Optically active polyanilines that were readily soluble in various organic solvents were prepared by oxidation of aniline with an electron acceptor, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in the presence of (+)- or (−)-camphorsulfonic acid (CSA). Their chiroptical properties in solutions are strongly dependent on the nature of organic solvents and structure of monomers.
Gas Phase Hydrogen Electrooxidation Using an Integrated Ultramicroelectrode
Authors: Umeda Minoru , Dokko Kaoru , Mohamedi Mohamed , Itoh Takashi , Uchida Isamu
Published: January 2003

We have demonstrated a hydrogen electrooxidation in the gas phase by employing a Nafion-coated integrated ultramicroelectrode, which represents the three-phase interface of a membrane assembled electrode for a polymer electrolyte fuel cell. The limiting current of gas-phase hydrogen oxidation is proven to be more than ten times larger than that in hydrogen saturated water.
Characterization of Dendritic Polymer-Modified Porous Silica Particles Using Size Exclusion Chromatography
Authors: Sakai Kiyoshi , Teng Tan Chun , Katada Aya , Harada Tomomi , Uemura Shinobu , Asami Yukio , Sakata Masayo , Kunitake Masashi , Hirayama Chuichi
Published: January 2003

Dendritic polymer-modified porous silica particles prepared by poly(amidoamine) (PAMAM) dendrimer synthesis reaction were characterized by elementary analysis (EA) and size exclusion chromatography (SEC). EA demonstrated the successful alternate growth of dendritic layers on the particles. The phased growth of polymer moieties by cascade reactions filled pores on silica particle, and decreased Mlims. It was found that the pore-size distribution can be controlled by the generation number and the reaction conditions.
Aluminum Chloride–Iron Promoted Coupling of Sulfonyl Chlorides with Alkyl Halides in Aqueous Media
Authors: Saikia Promod , Laskar Dhrubojyoti D , Prajapati Dipak , Sandhu Jagir S
Published: January 2003

A simple and inexpensive procedure for the coupling of sulfonyl chlorides and alkyl halides with aluminum chloride–iron system at ambient temperature in high yield is achieved in aqueous media.
Crystal Structures and Electrical Properties of 1:1 and 4:1 PF6 Salts of BO–HBDTTwith an α′-Type Donor Arrangement
Authors: Takahashi Kazuko , Shirahata Takashi
Published: January 2003

Crystal structures and electronic properties of [BO–HBDTT][PF6] and [BO–HBDTT]4[PF6] have been clarified. The donor packing patterns in these salts can be basically classified into α′-type, in which the donor stacks in the twisted overlap mode regarding the 1,3-dithiole rings. Intrastack intermolecular C–H···O contacts play an important role in the metallic nature of [BO–HBDTT]4[PF6].
Synthesis of TBA–Silicalite-2 Zeolite Nanocrystals
Authors: Dong Jun-Ping , Sun Yao-Jun , Long Ying-Cai
Published: January 2003

Siliceous MEL-type (silicalite-2) zeolite nanocrystals with average particle size of less than 100 nm were hydrothermally synthesized in a reactant system of TBAOH–TEOS–H2O. Investigation by using XRD, SEM, 13C and 29Si MAS NMR, FT-IR and N2 adsorption shows that the nanocrystals are aggregates of primary particles free of intergrowth with MFI (silicalite-1) zeolite, and possess ∼ 34% silanol groups in the framework as well as ∼0.9 mL·g−1 of mesopore volume. Silicalite-2 nanocrystals exhibit the particular structural characteristics: vibration at 550 cm−1 in IR spectrum splits; the signal of methyl group of TBAOH in 13C MAS CP NMR spectrum appears as singlet, which is different from that of silicalite-2 single crystals.
Stereostructure and Bioactivities of Jolkinolide D
Authors: Kigoshi Hideo , Ichino Takao , Yamada Kaoru , Ijuin Yasuharu , Makita Solange Fumi , Uemura Daisuke
Published: January 2003

The stereostructure and bioactivities of jolkinolide D, a diterpenoid from Euphorbia jolkini, were investigated. Jolkinolide D inhibited tumor invasion into the basement membrane and induced apoptosis in tumor cells.
Efficient Anion Binding to Cerium(IV) Bis(porphyrinate) Double Decker Utilizing Positive Homotropic Allosterism
Authors: Yamamoto Masashi , Sugasaki Atsushi , Ikeda Masato , Takeuchi Masayuki , Frimat Karine , James Tony D , Shinkai Seiji
Published: January 2003

New cerium(IV) bis(porphyrinate) double decker bearing two pairs of anion binding sites was synthesized. This anion receptor can bind dianionic tartarate guest according to positive homotropic allosterism. Analysis using the Hill equation afforded log K (association constant) = 9.33 [(mol dm−3)−2] and n (Hill coefficient) = 2.1 (± 0.1). This is the first example where “static” anion binding has been combined with the “dynamic” allosteric system.
Vacuum-Ultraviolet Circular Dichroism Spectrophotometer Using Synchrotron Radiation: Optical System and On-line Performance
Authors: Ojima Noriyuki , Sakai Kenichi , Matsuo Koichi , Matsui Takashi , Fukazawa Tomoyuki , Namatame Hirofumi , Taniguchi Masaki , Gekko Kunihiko
Published: January 2003

With the aim of measuring the circular dichroism (CD) spectra of biomaterials in aqueous solutions in the vacuum ultraviolet region between 310 and 140 nm, an optical system withstanding high vacuum was incorporated into the beam line 15 of Hiroshima Synchrotron Radiation Center (HiSOR). The performance of the constructed system was confirmed to be satisfactory in the high-vacuum on-line experiments by monitoring the CD spectra of ammonium d-camphor-10-sulfonate, d- and l-alanines in water.
Formation and Growth of Spinel-type LiMn2O4 Single Crystals by LiCl–MnCl2 Flux Evaporation
Authors: Tang Weiping , Yang Xiaojing , Kanoh Hirofumi , Ooi Kenta
Published: January 2003

Octahedral and rectangle-like LiMn2O4 single crystals larger than 0.1 × 0.1 × 0.1 mm3 in size were synthesized by evaporating a melt of LiCl and MnCl2 at 750 °C. The nucleation and growth of the crystals proceeds on the wall of a pure alumina crucible. Phase analysis showed that purity of phase was affected by MnCl2 partial pressure.
Synthesis of Pyridine and Isoquinoline Derivatives by the Palladium-Catalyzed Cyclization of Olefinic Ketone O-Pentafluorobenzoyloximes
Authors: Tsutsui Hironori , Narasaka Koichi
Published: January 2003

Pyridines and isoquinolines are synthesized from olefinic ketone O-pentafluorobenzoyloximes by treatment with a catalytic amount of Pd(PPh3)4 in the presence of (n-Bu)4NCl and triethylamine.
Direct Observation of Extraction of Cu(II) into Microcapsules Containing 8-Quinolinol by Use of Capillary and Chemiluminescence Detection
Authors: Tsukagoshi Kazuhiko , Ouji Yukiteru , Nakajima Riichiro
Published: January 2003

In order to observe extraction behavior of a metal ion into microcapsules containing an extraction reagent, a new method using a fused-silica capillary and chemiluminescence (CL) detection was developed. The microcapsules were prepared from hexamethylenediamine and terephthaloyl chloride by interfacial polymerization. 8-Quinolinol was used as an extraction reagent, with which Cu(II) was extracted into the microcapsules. An aliquot of Cu(II) aqueous solution in the emulsion including the microcapsules was delivered by siphoning through the capillary to CL detection cell. The extraction of Cu(II) into the microcapsules was directly observed by measuring the Cu(II) concentration with the CL intensity.
Combinatorial Molecular Imprinting for Formation of Atrazine Decomposing Polymers
Authors: Takeuchi Toshifumi , Fukuma Daigo , Matsui Jun , Mukawa Takashi
Published: January 2003

Synthetic polymers capable of atrazine-selective decomposition were prepared by molecular imprinting. A combinatorial approach was employed using an automated polymer preparation/evaluation system for the selection of functional monomers to construct the atrazine decomposition sites. Combined use of methacrylic acid and 2-sulfoethyl methacrylate provided atrazine-decomposing polymers in which atrazine was converted to a non-toxic compound atraton and the imprinting effects enhanced the catalytic activity.
Direct Dehydrogenation of Methanol to Formaldehyde over Novel Ag-Containing Ceramics
Authors: Dong Yi , Dai Wei-Lin , Li Jia-Liang , Deng Jing-Fa
Published: January 2003

A novel silver-ceramics supported catalyst showing excellent activity and selectivity in the direct dehydrogenation of methanol to formaldehyde was prepared. The selectivity was as high as 100% and the yield of formaldehyde reached 70%.
Reversible Reduction and Reoxidation of Langmuir–Blodgett Films of Octacyanophthalocyanine Dilithium Complex
Authors: Xiang Hong-Qi , Tanaka Keiji , Takahara Atsushi , Kajiyama Tisato
Published: January 2003

Langmuir–Blodgett film of octacyanophthalocyanine dilithium complex with strong electron-withdrawing substituents was first prepared and its redox behavior was studied by cyclic voltammetry. The LB film exhibited excellent redox reversibility in an acid electrolyte. In contrast to the case of a solution-casting film, two couples of redox peaks were clearly discerned on the voltammetric curve. Also, the linear dependence of cathodic current on scan rate was kept up to 4000 mV s−1, which was 10 times larger than that of the solution-casting film.
Correlation between Phototoxicity and Photoionization Efficiency of Phenothiazine Drugs
Authors: Kojima Masanobu , Nebashi Satomi , Nakamura Kimitoshi , Ikeda Tsunehiko , Yatsushiro Akiko , Tajima So , Tobita Seiji
Published: January 2003

Irradiation of sodium hyaluronate (NaHA) in the presence of phenothiazine derivatives (PTZ) caused degradation of the biopolymer. It was found that measurement of the degradation efficiency was useful for estimation of the phototoxicity of the phenothiazine drugs. The results of laser photolysis suggested that the photoionization of PTZ is a key step in initiating degradation of NaHA.
Synthetic Studies on Lycopodium Alkaloid, Magellanine: Stereoselective Construction of Functionallized Angular Tricyclic Skeletons by Intramolecular Pauson–Khand Reaction
Authors: Ishizaki Miyuki , Niimi Yuka , Hoshino Osamu
Published: January 2003

Angular tricyclic compounds as intermediates for total synthesis of magellanine were synthesized by stereoselective Ireland–Claisen rearrangement and intramolecular Pauson–Khand reaction of exo-methylenecyclohexylalkynes. Interestingly, remarkably different reactivity was observed in the Pauson–Khand reaction of cis- and trans-disubstituted exo-methylenecyclohexylalkynes.
Electrochemical Formation of Hydrogen Atom Adduct of 5,5-Dimethyl-1-pyrroline-N-oxide and Its Mechanism
Authors: Endo Nobuyuki , Higashi Kousuke , Tajima Kunihiko , Makino Keisuke
Published: January 2003

In order to make the method of spin trapping technique with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) more powerful in biological investigation, using electrochemical reaction, we have developed the method to observe an ESR spectrum composed of only a spin adduct of hydrogen atoms (DMPO-H). It has been elucidated that DMPO-H is produced through the hydrogen atom formation, not through the reduction of DMPO.
The First Lower-Rim O-Arylation of Calix[4]arenes
Authors: Zeng Xianshun , Weng Linhong , Zhang Zheng-Zhi
Published: January 2003

The first lower-rim full O-pyridyl and O-quinolyl ether derivatives of calix[4]arene and p-tert-butylcalix[4]arene in 1,3-alternate conformation have been synthesized using cesium carbonate as a promoter at high reaction temperature and their structures and conformations were characterized by 1H NMR spectra and X-ray crystallography.
A New Type of Cation Responsive Chromoionophore with Spectral Sensitivity in the Near-Infrared Spectral Range
Authors: Citterio Daniel , Sasaki Shin-ichi , Suzuki Koji
Published: January 2003

A long wavelength absorbing cation responsive chromoionophore 1 based on the strongly π-electron accepting dicyanovinylindane subunit and an electron donating N-phenylazacrown ether binding site was synthesized. The absorption spectra of this compound in CH3CN show strong changes in the near-infrared (NIR) spectral range upon binding of cations in the crown-ether moiety.
Synthesis of 1-Stibaphenalenes, the First Example of Group 15 Phenalenes, via a 1,5-Dilithium Intermediate
Authors: Yasuike Shuji , Niwa Mayumi , Yamaguchi Kentaro , Tsuchiya Takashi , Kurita Jyoji
Published: January 2003

The first examples of 1-stibaphenalenes 1 and 6 have been prepared by the condensation of dibromophenylstibane with 1,5-dilithium intermediate 5, generated in situ from (Z)-1-bromo-2-[1-(8-bromonaphthyl)]-1-trimethylsilylethene (4). Single crystal X-ray analysis of 1 revealed that the naphthalene and the fused stibinine ring are almost coplanar (mean deviation 0.0264 Å), and the phenyl group on the antimony is oriented perpendicular with the phenalene ring.
An Interference-Free, Amperometric Biosensor for Acetic Acid Based on a Tri-enzyme/polydimethylsiloxane-bilayer Membrane
Authors: Mizutani Fumio , Sawaguchi Takahiro , Iijima Seiichiro
Published: January 2003

An amperometric acetate-sensing electrode with high performance characteristics, such as high selectivity (e.g., free from the interference by ethanol, l-cysteine and hydrogen peroxide) and high stability (usable for a month), was prepared by immobilizing acetate kinase, pyruvate kinase and pyruvate oxidase on a polydimethylsiloxane-coated oxygen electrode.
Selective Hydration of a Carboxylate Group in Nitrobenzene
Authors: Osakai Toshiyuki , Nakata Sachiko , Ogawa Hajime
Published: January 2003

Eight different carboxylate ions were extracted with Crystal Violet into nitrobenzene. The Karl Fischer method was employed to determine the numbers of water molecules co-extracted with the carboxylate ions, i.e., their hydration numbers (nh) in nitrobenzene. The values of nh for the carboxylate ions were little dependent on their chemical structures, being 2.4 ± 0.2 as the average value.
Three-Dimensional Polymers with Metal–Oxygen and Metal–Ligand Chains: [Mn(II)(4,4′-bipy)2(Cr2O7)(H2O)2] and [Co(II)(4,4′-bipy)2(Cr2O7)]
Authors: Hayashi Yoshihito , Tagami Tomoko , Mano Hidesato , Uehara Akira
Published: January 2003

Reaction of aqueous solutions of [M(H2O)6](ClO4)2 (M = Mn(II) and Co(II)) and dichromate ion with 4,4′-bipy provides coordination polymers with metal–oxygen chain. The structure of [Mn(4,4′-bipy)2(Cr2O7)(H2O)2] reveals the 2D sheet structure which is constructed by hydrogen bonding between 1D chains, while [Co(4,4′-bipy)2(Cr2O7)] shows hybrid 3D polymers which have metal–bipy square grid and the dichromate pillar forms an interpenetrated cuboidal 3D structure.