bluuebunny/crossref_metadata_2025 huggingface dataset:
CD14 Monocyte Receptor, Involved in the Inflammatory Cascade, and Insulin Sensitivity
Authors: Fernández-Real José Manuel , Broch Montserrat , Richart Cristóbal , Vendrell Joan , López-Bermejo Abel , Ricart Wifredo
Published: April 2003

Soluble CD14 (sCD14), detectable at high concentrations constitutively present in the circulation, plays a key role in the neutralization of lipopolysaccharide, one of the most potent biologic response modifiers currently recognized and involved in the regulation of the inflammatory cascade. We tested whether circulating sCD14 was linked to inflammatory parameters and to insulin resistance in apparently healthy subjects.

Serum sCD14 concentration did not significantly correlate with body mass index (BMI), waist to hip ratio, systolic or diastolic blood pressure, serum glucose, fasting insulin, fasting insulin resistance index [homeostasis model assessment (HOMA)], or serum uric acid among 123 subjects. The association between sCD14 and fasting insulin (r = −0.19, P = 0.08) and between sCD14 and HOMA (r = −0.21, P = 0.06) tended toward statistical significance among men. Unexpectedly, sCD14 correlated positively with fasting triglycerides (TG) in all the subjects (r = 0.22, P = 0.014), and this association was most significant in men (r = 0.34, P = 0.002). After controlling for TG, the relationships between sCD14 levels and fasting insulin (r = −0.25, P = 0.029), HOMA (r = −0.28, P = 0.014), and uric acid (r = −0.30, P = 0.006) were significant in men. Among nonsmoking men (n = 44), sCD14 significantly correlated with waist diameter (r = −0.30, P = 0.03), diastolic blood pressure (r = −0.34, P = 0.022), and HOMA (r = −0.30, P = 0.03). In a multiple linear regression analysis, BMI (P < 0.00001), TG (P = 0.003), and sCD14 (P = 0.04) (but not age, sex, waist, or smoking status) independently contributed to 26% of HOMA variance.

A polymorphism of the CD14 gene, a C-to-T transition at bp −159 from the major transcription start site, seems to play a significant role in regulating serum sCD14 levels. In a subsample of 33 healthy subjects, carriers of the T allele were similar (in age, sex, BMI, fat mass, waist to hip ratio, blood pressure, and fasting glucose and insulin levels) to C/C homozygotes. In the former, integrated area under the curve for serum glucose concentrations after an oral glucose tolerance test was significantly lower (P = 0.02), and insulin sensitivity (SI) index (minimal model analysis) significantly higher (P = 0.036), than in C/C homozygotes. Among 32 type 2 diabetic subjects, carriers of the T allele also showed a significantly higher SI index (P = 0.03) and had significantly lower C-reactive protein (P = 0.03) and lower circulating soluble intercellular adhesion molecule-1 concentrations (P = 0.01) than did C/C homozygotes.

To our knowledge, this is the first study to suggest an effect of a genetic polymorphism on both SI (healthy subjects and type 2 diabetic patients) and endothelial dysfunction (sICAM-1 levels) in type 2 diabetes mellitus.
A Combined Approach for Gene Discovery Identifies Insulin-Like Growth Factor-Binding Protein-Related Protein 1 as a New Gene Implicated in Human Endometrial Receptivity
Authors: Domínguez Francisco , Avila Silvia , Cervero Ana , Martín Julio , Pellicer Antonio , Castrillo José Luis , Simón Carlos
Published: April 2003

In the past, human endometrial receptivity has been investigated by chasing specific molecules throughout the menstrual cycle. Now the genomic approach allows us to investigate the hierarchical contribution of a high number of genes to a specific function. In this study, we analyzed differentially the gene expression pattern of 375 human cytokines, chemokines, and related factors, plus that of their receptors, in endometrial receptivity. To do this, we used a combined approach of human endometrium and cell lines. We have compared the gene expression pattern in receptive vs. prereceptive human endometria and contrasted the results with gene expression in the highly adhesive cell line (to JAR cells and mouse blastocysts) RL95-2 vs. HEC-1A, a cell line with markedly less adhesiveness. IGF-binding protein-related protein 1 (IGFBP-rP1), also known as IGFBP-7/mac 25, was the second most up-regulated gene in both of the investigated models. These results were corroborated by performing RT-PCR on the same RNA samples and validated by quantitative fluorescent RT-PCR and in situ hybridization in endometrium throughout the menstrual cycle. Interestingly, a 35-fold increase in expression during the receptive phase was compared with the prereceptive phase followed by a sharp increase in the late luteal. Further quantitative fluorescent RT-PCR experiments using the epithelial and stromal endometrial fraction throughout the menstrual cycle confirmed that IGFBP-rP1 expression was localized in the epithelial and stromal compartments and up-regulated mainly in the latter. In situ experiments confirmed the endometrial localization and regulation of IGFBP-rP1 mRNA. At the protein level, IGFBP-rP1 was localized by immunohistochemistry at the apical part of the luminal and glandular epithelium, stromal, and endothelial cells. In conclusion, using a genomic approach with a combined experimental design of receptivity in vivo and in vitro, we have discovered the implication of IGFBP-rP1 in endometrial physiology, which seems related to endometrial receptivity.
Leptin and Body Fat in Type 2 Diabetes and Monodrug Therapy
Authors: Sivitz William I. , Wayson Sheila M. , Bayless Margaret L. , Larson Linda F. , Sinkey Christine , Bar Robert S. , Haynes William G.
Published: April 2003

To better understand the relations among leptin, insulin, and body fat during the metabolic progression to diabetes and during drug monotherapy, metabolic parameters were examined in subjects classified as 1) type 2 diabetes; 2) impaired fasting glucose or mild diabetes mellitus; 3) nondiabetic, matched for body mass index (BMI); and 4) nonobese, nondiabetic. Diabetic subjects were also studied during no pharmacological treatment, after 3 months of randomization to metformin or glyburide, and after 3 months of cross-over to the opposite drug. Log leptin correlated more with percent body fat (slope, 0.042; confidence interval, 0.036–0.047; r2 = 0.826; P < 0.0001) than with total fat mass, percent truncal or nontruncal fat, or BMI. When normalized to percent fat, leptin did not differ by gender. Leptin normalized to percent fat was 35% less in untreated diabetes than that in BMI-matched controls (P < 0.001). Leptin normalized to percent fat was increased by 25% (P < 0.01) as a result of glyburide therapy compared with pretreatment values, but was unchanged by therapy with metformin. Across a spectrum of subjects with diabetes, impaired fasting glucose/mild diabetes, or BMI-matched nondiabetic controls, normalized leptin significantly correlated with glucose-induced insulin release, but not with insulin sensitivity. Our data suggest that plasma leptin is reduced in untreated type 2 diabetes probably as a consequence of reduced insulin secretion and that circulating leptin concentrations are differentially affected by monodrug therapy.
A Consensus Report of the Role of Serum Thyroglobulin as a Monitoring Method for Low-Risk Patients with Papillary Thyroid Carcinoma
Authors: Mazzaferri E. L. , Robbins R. J. , Spencer C. A. , Braverman L. E. , Pacini F. , Wartofsky L. , Haugen B. R. , Sherman S. I. , Cooper D. S. , Braunstein G. D. , Lee S. , Davies T. F. , Arafah B. M. , Ladenson P. W. , Pinchera A.
Published: April 2003

Recent studies have provided new information regarding the optimal surveillance protocols for low-risk patients with differentiated thyroid cancer (DTC). This article summarizes the main issues brought out in a consensus conference of thyroid cancer specialists who analyzed and discussed this new data.

There is growing recognition of the value of serum thyroglobulin (Tg) as part of routine surveillance. An undetectable serum Tg measured during thyroid hormone suppression of TSH (THST) is often misleading. Eight studies show that 21% of 784 patients who had no clinical evidence of tumor with baseline serum Tg levels usually below 1 μg/liter during THST had, in response to recombinant human TSH (rhTSH), a rise in serum Tg to more than 2 μg/liter. When this happened, 36% of the patients were found to have metastases (36% at distant sites) that were identified in 91% by an rhTSH-stimulated Tg above 2 μg/liter. Diagnostic whole body scanning, after either rhTSH or thyroid hormone withdrawal, identified only 19% of the cases of metastases. Ten studies comprising 1599 patients demonstrate that a TSH-stimulated Tg test using a Tg cutoff of 2 μg/liter (either after thyroid hormone withdrawal or 72 h after rhTSH) is sufficiently sensitive to be used as the principal test in the follow-up management of low-risk patients with DTC and that the routine use of diagnostic whole body scanning in follow-up should be discouraged. On the basis of the foregoing, we propose a surveillance guideline using TSH-stimulated Tg levels for patients who have undergone total or near-total thyroidectomy and 131I ablation for DTC and have no clinical evidence of residual tumor with a serum Tg below 1 μg/liter during THST.
Mitochondria of Human Adrenal Cortex Have Tubular Cristae with Bulbous Tips
Authors: Riva Alessandro , Loffredo Felice , Uccheddu Alessandro , Riva Francesca Testa , Tandler Bernard
Published: April 2003

By taking advantage of a modified osmium maceration technique, we have been able to examine by high resolution scanning electron microscopy (HRSEM) the interior of human adrenocortical mitochondria from which all soluble material has been extracted. The so-called vesicles apparent in thin sections examined by transmission electron microscopy actually are finger-like cristae as determined by HRSEM. These digitiform cristae have a segmented appearance and a bulbous tip. The segmented form of the cristae may have important metabolic implications.
Crystal Structure of 2,6-Dimethylpyridinium Hydrogen Fumarate: Hydrogen Bonds of C(sp3)–H···O, C(sp2)–H···O and N+–H···O−(sp3)
Authors: Pan Yuan Jiang , Jin Zhi Min , Sun Cui Rong , Jiang Chong Wen
Published: April 2003

X-ray diffraction study on 2,6-dimethylpyridinium hydrogen fumarate reveals that the same site of O−(sp3) is confined by hydrogen bonds not only of N+–H···O−, but also those of C(sp3)–H···O and C(sp2)–H···O.
The First Synthesis of Stilbene Dendrimers and their Photochemical trans–cis Isomerization
Authors: Mizutani Takuo , Ikegami Masashi , Nagahata Ritsuko , Arai Tatsuo
Published: April 2003

Highly branched stilbene dendrimers underwent trans–cis isomerization in the excited singlet state within the lifetime of 10 ns.
A Rational Design of Helix: Absolute Helix Synthesis by Binaphthyl-Salen Fusion
Authors: Furusho Yoshio , Maeda Takeshi , Takeuchi Takeshi , Makino Nobuaki , Takata Toshikazu
Published: April 2003

A rational design of helical molecules is presented. Fusing chiral binaphthyl units and metallosalen complexes resulted in formation of molecules which inevitably adopt certain helical conformations.
Effective Second-Order Nonlinear Optical Coefficient of a Novel Transparent Material: N,N-Diphenyl-8-[2-(4-pyridyl)ethenyl]dibenzofuran-2-ylamine
Authors: Kawamata Jun , Akiba Masaharu , Inagaki Yoshio
Published: April 2003

N,N-Diphenyl-8-[2-(4-pyridyl)ethenyl]dibenzofuran-2-ylamine (1) has been synthesized and its second-order nonlinear optical coefficient has been examined by means of Second Harmonic Wave Generated with the Evanescent Wave (SHEW) method. As a result, 1 has been found to exhibit an effective d coefficient 3.0 times as large as that of urea. The cutoff wavelength of the compound was estimated to be 370 nm.
Regio- and Stereoselective Addition of Ketene Silyl Acetals to Quinolinium Salts by Way of an Intramolecular C=O···Qu+ or C=S···Qu+ Interaction
Authors: Yamada Shinji , Morita Chisako
Published: April 2003

Chiral 1,4-dihydroquinolines were synthesized by the addition of ketene silyl acetals to quinolinium salts. The stereoselectivity was associated with the intramolecular interaction between the quinolinium and the carbonyl or thiocarbonyl groups, which was revealed by 1H NMR spectroscopy and X-ray analysis.
A One-Step Synthesis of Reactive Polycarbonate Precursors by the Coupled Oxidative Carbonylation of Bisphenol-A and Phenol with Carbon Monoxide
Authors: Kim Won Bae , Lee Jae Sung
Published: April 2003

The reactive polycarbonate precursors of phenyl carbonate-ended oligomers amenable to polycondensation in the phosgene-free polycarbonate process were catalytically synthesized via a novel one-step reaction of the coupled oxidative carbonylation of bisphenol-A and phenol with carbon monoxide.
Assignment of the C K-Shell Photoabsorption Spectrum of CF3CN Molecule
Authors: Okada Kazumasa , Tanimoto Shuichiro , Ibuki Toshio , Saito Ko , Gejo Tatsuo
Published: April 2003

Assignment of the total C photoabsorption spectrum of CF3CN in the K-shell region has been established with the help of an angle-resolved photofragment ion spectroscopy. The anisotropy parameters for the energetic CF3+ and CN+ fragments were evaluated at the selected photon energies. The linear C–C≡N skeleton basically held in this region since the strongly negative anisotropy parameters were obtained at the πCN* ← CF(1s) transition.
Improved Solid-State Dye Solar Cells with Polypyrrole using a Carbon-Based Counter Electrode
Authors: Kitamura Takayuki , Maitani Masato , Matsuda Mizuho , Wada Yuji , Yanagida Shozo
Published: April 2003

Solid state dye-sensitized solar cell using polypyrrole as a hole transport layer was improved. Carbon-based counter electrode gave a good electric contact with the hole transport layer of polypyrrole to give higher cell performance compared to the cell with gold or platinum counter electrode.
Facilitated Transfer of Hydrophilic Anions across the Nitrobenzene–Water Interface by a Hydrogen-Bonding Ionophore: Applicability for Multianalyte Detection
Authors: Nishizawa Seiichi , Yokobori Tomoyuki , Shioya Takeshi , Teramae Norio
Published: April 2003

A hydrogen bond-forming bis-thiourea 3 can effectively facilitate the transfer of various hydrophilic anions, such as Cl−, CH3COO−, H2PO4−, HPO42− and SO42−, across the nitrobenzene–water interface, suggesting possible use of 3 for multianalyte detection with an amperometric sensing mode.
Electrical Properties of tert-Butyl-Substituted Germanium Cluster
Authors: Watanabe Akira , Unno Masashi , Hojo Fusao , Miwa Takao
Published: April 2003

Conductive amorphous germanium film was prepared by heat treatment of tert-butyl-substituted germanium cluster at 200 °C and the crystallization was observed above 500 °C, which are remarkably lower temperatures than those of n-propyl-substituted germanium cluster.
Synthesis of a Tridentate Hydrosilane and Its Reaction with Palladium(0) Complexes
Authors: Chen Wanzhi , Shimada Shigeru , Hayashi Teruyuki , Tanaka Masato
Published: April 2003

A new tridentate hydrosilane (2-SiH3C6H4)2SiH2 reacts with a mixture of Pd(Pet3)4 and R2PCH2CH2PR2 (R = Me or Et) to give dinuclear (silyl)(µ-silylene)palladium(II) complexes, while the reaction with a mixture of Pd(Pet3)4 and Cy2PCH2CH2Pcy2 (Cy = cyclohexyl) afforded a mononuclear (silyl)(disilanyl)palladium(II) complex, the Si–Si bond of which was formed by the intramolecular dehydrocoupling. The structures of the new complexes were determined by X-ray diffraction.
The Quest of Stable Silanones: Substituent Effects
Authors: Kimura Masahiro , Nagase Shigeru
Published: April 2003

In quest of isolable silanones (R2Si=O), substituent effects are theoretically investigated. Substituent groups worthy of experimental testing are predicted, which make silanones kinetically stable toward dimerization and isomerization.
Unexpected Reactions of an Isolable Dialkylsilylene with Haloalkanes
Authors: Ishida Shintaro , Iwamoto Takeaki , Kabuto Chizuko , Kira Mitsuo
Published: April 2003

Reactions of an isolable dialkylsilylene with dichloromethane and (chloromethyl)cyclopropane occur in solution to afford the double silylene insertion product and an unusual 5-silaspiro[4.4]nonane derivative, respectively. The activation of the carbon–chlorine bonds due to the complexation of haloalkanes with the silylene may facilitate the nucleophilic attack of another silylene under the present reaction conditions.
Hydrolytic Stability of Ribose Phosphodiester Bonds within Several Oligonucleotides at High Temperatures Using a Real-Time Monitoring Method for Hydrothermal Reactions
Authors: Kawamura Kunio
Published: April 2003

The hydrolytic stability of ribose phosphodiester bond within several types of oligonucleotides was measured at 150–200 °C using a real-time monitoring method. It was observed that the stability of a phosphodiester linkage is dependent on the surrounding sequences of the phosphodiester linkage at high temperatures. The fact indicates that some weak interactions, such as hydrophobic interaction, might be effective within the oligonucleotides at high temperatures.
Gelation of Ionic Liquids with a Low Molecular-Weight Gelator Showing Tgel above 100 °C
Authors: Ikeda Atsushi , Sonoda Kenshi , Ayabe Masatsugu , Tamaru Shun-ichi , Nakashima Takuya , Kimizuka Nobuo , Shinkai Seiji
Published: April 2003

In an attempt to obtain solidified ionic liquids a cholesterol-based gelator has been applied to gelation of these liquids. By addition of a small amount of low molecular-weight gelator 1, ionic liquids such as N,N′-dialkyl-substituted imidazolium ions and N-alkyl pyridinium ions are easily gelated to give the sufficiently thermostable physical gels.
A Useful and Environmentally Benign Synthetic Protocol for Dethiolization by Employing Vanadium Pentoxide Catalyzed Oxidation of Ammonium Bromide by Hydrogen Peroxide
Authors: Mondal Ejabul , Bose Gopal , Sahu Priti Rani , Khan Abu T
Published: April 2003

A wide variety of thioacetals and thioketals can be cleaved chemoselectively in presence of olefin and aromatic ring as well as other protecting groups to carbonyl compounds by employing V2O5 catalyzed oxidation of ammonium bromide by H2O2 in CH2Cl2–H2O solvent system; mild conditions, high selectivity, good yield, and no side products such as bromination or oxidation are some of the major advantages.
Insoluble Lithium Complex of Polyether Carboxylic Acids Consisting of Naphthalene Repeating Unit and Its Stable Monolayer on Aqueous Surfaces
Authors: Taguchi Kazuhiro , Murakami Teiichi , Higuchi Masahiro , Goto Midori , Hiratani Kazuhisa , Okada Akemi , Akabori Sadatoshi , Miyake Yasuhito , Miyata Mikiji
Published: April 2003

We synthesized several polyether dicarboxylic acids with naphthalene and trimethylene groups as repeating units. The polyethers selectively formed complexes with lithium, an alkali metal. In contrast to the typical polyethers, their alkali metal complexes exhibited very low solubilities for water and hydrophobic organic solvents such as chloroform and toluene. Polyethers having seven naphthalene units formed a stable monolayer on an aqueous subphase, only when alkali metal hydroxides were added, but not acid.
Assistance of Core-Ion Dissociation by Energy Transmission from Solvent Molecules in N3O3−(NO)n (n = 0–38) Impact onto Silicon Surface
Authors: Yamaguchi Hitoshi , Yasumatsu Hisato , Kondow Tamotsu
Published: April 2003

A size-selected cluster anion, N3O3−(NO)n (n = 0–38), was allowed to collide onto a silicon surface, and the product anions, NO2−, N2O2− and N3O3−(NO)m (m = 0–2), from the surface were observed mass-spectroscopically. The branching fractions of the product anions were measured as functions of the energy of the incoming parent cluster anion and the size, n. It was found that NO molecules located in the vicinity of the core ion, N3O3−, transmit their kinetic energy to N3O3− most efficiently.
A New Maturity Indicator of Sedimentary Organic Matter Based on Thermal Fission of Allylic Bond in Porphyrins
Authors: Nomoto Shinya , Kozono Masaki , Mita Hajime , Shimoyama Akira
Published: April 2003

A 3-ethyl-4-methylpyrrole unit in etioporphyrin was shown to be converted to a 3,4-dimethylpyrrole unit by the action of heat, which was proved to be catalyzed by Na-montmorillonite. Time courses of the reaction could be followed by analyzing 2-ethyl-3-methyl- and 2,3-dimethylmaleimide after chromic acid oxidation of the porphyrin. The ratio of these maleimides was proposed as a new maturity indicator for sedimentary organic matter.
Ring-Opening Glycosylation of a Chitobiose Oxazoline Catalyzed by a Non-Chitinolytic Mutant of Chitinase
Authors: Sakamoto Junji , Watanabe Takeshi , Ariga Yumiko , Kobayashi Shiro
Published: April 2003

Ring-opening glycosylation of a chitobiose oxazoline was exclusively achieved by catalysis of a mutated chitinase that is only active for the glycosylation and not for chitinolysis.
Novel Anode Material for Lithium-ion Batteries: Carbon-Coated Silicon Prepared by Thermal Vapor Decomposition
Authors: Umeno Tatsuo , Fukuda Kenji , Wang Hongyu , Dimov Nikolay , Iwao Takashi , Yoshio Masaki
Published: April 2003

Carbon-coated Si has been prepared by thermal vapor decomposition technique. The electrochemical behaviors of carbon-coated Si together with Si have been investigated as anode materials for lithium-ion batteries. The good cycleability of carbon-coated Si under lithiation capacity of 1200 mA h/g has been correlated with ex situ XRD patterns as well as SEM graphs.
Synthesis of Nanowires and Coral-Shaped Nanostructures of Ag by an Ultraviolet Photo-Reduction Technique at Room Temperature
Authors: Zhou Yong , Hao Lingyun , Hu Yuan , Zhu Yurui , Chen Zuyao
Published: April 2003

Nanowires and coral-shaped nanostructures of Ag were prepared by an ultraviolet photo-reduction technique at room temperature.
Design of a Novel Cyclopropane Donor Bis(trimethylsilylmethyl)cyclopropane and Its Electron Transfer Reactions
Authors: Oku Akira , Yamauchi Yoshihito , Schroeder Marc
Published: April 2003

A novel donor of SET reactions, 1,1-bis(trimethylsilylmethyl)-2-phenylcyclopropane (BTCP), was designed to function as a homoallylic 1-phenyl-3-(trimethylsilylmethyl)-3-butenyl radical (5). Thus, non-irradiated reaction of BTCP with DDQ or chloranil gave a six-membered cyclic compound, which corresponds to a Diels–Alder adduct of 3-trimethylsilylmethyl-1,3-butadiene derived from BTCP. The photoinduced electron transfer reaction of BTCP with ketones afforded the C–C coupling products of 5 in high yields.
The First Stable Aromatic S-Nitrosothiol: Synthesis, Structure and Reactivity
Authors: Itoh Maiko , Takenaka Keiko , Okazaki Renji , Takeda Nobuhiro , Tokitoh Norihiro
Published: April 2003

The first stable aromatic S-nitrosothiol, S-nitroso-4-t-butyl-2,6-bis[(2,2″, 6,6″-tetramethyl-m-terphenyl-2′-yl)methyl]benzenethiol, was synthesized by the nitrosation of the corresponding thiol and the structure was established by X-ray crystallography. Its oxidation and reactions with some nucleophiles were carried out.
CD Investigation of Porphyrin–Porphyrin Interaction with Links to Acyclic β-Sheet Peptide Self-Assembled in an Aqueous Media
Authors: Arai Toru , Inudo Makiko , Ishimatsu Tomomi , Sasaki Tomikazu , Kato Tamaki , Nishino Norikazu
Published: April 2003

Amphiphilic peptide, Ac-Cys(Por)-Lys-Val-(-Ser-Val-)n-Lys-Val-NH2 (n = 0 or 1, Cys(Por) = side-chain porphyrin-linked Cys), self-assembled to form the β-sheet in buffer solution-2,2,2-trifluoroethanol and showed exciton coupled Cotton effects in the porphyrin region due to the closely oriented porphyrins.
General and Greener Route to Ketones by Palladium-Catalyzed Direct Conversion of Carboxylic Acids with Organoboronic Acids
Authors: Kakino Ryuki , Narahashi Hirohisa , Shimizu Isao , Yamamoto Akio
Published: April 2003

Cross-coupling reaction of carboxylic acids with organoboron compounds catalyzed by palladium complexes in the presence of an activator such as dimethyl dicarbonate under mild conditions gives ketones in excellent yields except for certain substrates.
Preparation of Fine Sr2CeO4 Particles for a Blue Phosphor
Authors: Chiga Takanobu , Masui Toshiyuki , Imanaka Nobuhito , Adachi Gin-ya
Published: April 2003

Fine Sr2CeO4 particles of a blue emission phosphor have been synthesized using a chemical co-precipitation technique, and the textual and optical properties were compared with the one synthesized by the conventional solid-state reaction method. Mean particle size of the prepared Sr2CeO4 fine particles was smaller than that given by the sample prepared from the solid-state reaction method. However, photoluminescence intensity was maintained in spite that it usually decreases with the particle size reduction.
Electrochemical Studies for Interaction between [Cu(salen)] and La(III) Ion in N,N-Dimethylformamide
Authors: Manseki Kazuhiro , Shimizu Yuko , Obata Akiko , Sakiyama Hiroshi , Unoura Kei , Sakamoto Masatomi , Nishida Yuzo , Sadaoka Yoshihiko , Okawa Hisashi
Published: April 2003

The interaction between [Cu(salen)] and La(III) in DMF was studied by cyclic voltammetry and EQCM (Electrochemical Quartz Crystal Microbalance) technique. The quasi-reversible redox wave of [Cu(salen)] around −1.1 V vs Ag/AgCl was replaced by a reduction wave around −0.9 V on forming a [Cu(salen)···La] complex. The CuLa complex disproportionated on the electrode to exhibit an anodic stripping of Cu(0) to Cu(II) around +0.2 V.
A 3-Volt Lithium-Ion Cell with Li[Ni1/2Mn3/2]O4 and Li[Li1/3Ti5/3]O4 : A Method to Prepare Stable Positive-Electrode Material of Highly Crystallized Li[Ni1/2Mn3/2]O4
Authors: Ohzuku Tsutomu , Ariyoshi Kingo , Yamamoto Satoshi , Makimura Yoshinari
Published: April 2003

Li[Ni1/2Mn3/2]O4 having a spinel-framework structure was prepared by a two-step solid state reaction, i.e., crystallization at 1000 °C followed by an oxidation at 700 °C in air, and examined in nonaqueous lithium cells. Thus prepared Li[Ni1/2Mn3/2]O4 showed low polarization and stability against electrolyte oxidation with rechargeable capacity of about 110–130 mAh/g at 4.7 V with 10–30 mAh/g at 4.0 V vs Li. Capacity in region of ca. 4.0 V vs Li, which was usually observed for the samples prepared by the conventional method, can be minimized by the oxidation process at 700 °C. A 3-volt lithium-ion battery with two insertion materials based on lithiated transition metal oxides having spinel-framework structures is demonstrated therefrom.
Spindle-Type EuO Nanocrystals and Their Magnetic Properties
Authors: Thongchant Supitcha , Hasegawa Yasuchika , Wada Yuji , Yanagida Shozo
Published: April 2003

EuO nanocrystals were prepared by liquid phase reaction of europium metal in liquid ammonia for the first time. TEM revealed that the EuO nanocrystals had a spindle shape with mean length of 280 nm (a) by mean width of 95 nm (b). The SQUID measurement showed that the EuO nanocrystals turned into ferromagnetic phase at 70 K and 150 K.
Regioselective Photohydroxylation of Quinolinium Ions in Smectite Clay Interlayers
Authors: Usami Hisanao , Shimizu Yoshiaki , Fujimatsu Hitoshi , Iijima Takashi
Published: April 2003

Quinolinium and N-methylquinolinium intercalated in smectite clays were irradiated with ultraviolet light longer than 300 nm under air atmosphere. 5-Hydroxyquinolinium was primarily obtained in both systems.
White Light Optical Waveguide Detection of Transient Absorption Spectra in Ultrathin Organic Films upon Pulsed Laser Excitation
Authors: Kawai Hideki , Nakano Kazuhiro , Nagamura Toshihiko
Published: April 2003

White light optical waveguide (WOWG) method was applied to transient absorption spectroscopy of ultrathin polymer films. Tetraphenylporphinetetrasulfonic acid (TPPS) in poly(vinyl alcohol) films on the surface of OWG glass was excited with the second harmonics of a nanosecond Nd:YAG laser. The transient absorption spectrum of excited triplet TPPS was detected highly sensitively for a film with the absorbance at 532 nm of only 0.0005.
Tautomeric Equilibrium of Fluorescein in Solution: Ab Initio Calculations
Authors: Jang Yun Hee , Hwang Sungu , Chung Doo Soo
Published: April 2003

The tautomeric equilibrium of fluorescein was investigated by calculating the relative free energies of various tautomers at neutral, anionic, and dianionic states both in the gas phase and in solution (water or DMSO) using an ab initio quantum mechanical method (B3LYP/6-31++G**) in combination with the Poisson–Boltzmann continuum solvation approach.
Synthesis of Carthamin Acetate, the Red Pigment in Safflower Petals
Authors: Sato Shingo , Kumazawa Toshihiro , Watanabe Hiroyuki , Takayanagi Koji , Matsuba Shigeru , Onodera Jun-ichi , Obara Heitaro , Furuhata Kimio
Published: April 2003

Carthamin acetate, (3S,3′S)-1-[5-(p-acetoxycinnamoyl)-3-C-(β-d-2″,3″,4″,6″-tetra-O-acetylglucopyranosyl)-3,4-dihydroxy-2,6-diketo]cyclohex-4-enylidene-1′-[5′-(p-acetoxycinnamoyl)-3′-C-(β-d-2″′,3″′,4″′, 6″′-tetra-O-acetylglucopyranosyl)-2′,3′,4′-trihydroxy-6′-keto]cyclohexa-1′,4′-dienylmethane 7a and its (3R, 3′R)-epimer 7b were synthesized via the C-glycosylation of 2-acetyl-1,3,4,5-benzenetetrol using acetobromoglucose in the presence of sodium hyride, followed by aldol condensation with p-hydroxybenzaldehyde after methyl-protection of the enolic hydroxy group, and subsequent dimerization with triethyl orthoformate after demethylation, in a total yield of 0.6%. Their absolute configurations were determined by X-ray analysis of the key intermediate 4b.
Preparation of High Activity Catalyst for Ammonia Synthesis by Supporting Well-Defined Ru Nanoparticles on γ-Al2O3
Authors: Miyazaki Akane , Balint Ioan , Aika Ken-ichi , Nakano Yoshio
Published: April 2003

Uniform ruthenium metal nanoparticles with an average diameter of 5 nm have been prepared and supported on γ-Al2O3 up to 6.3 wt%. The Ru/Al2O3 catalyst prepared by this method had unusually high activity for ammonia synthesis. The rate of ammonia formation was at least 12 times higher than the rate of non-promoted Ru/Al2O3 catalysts prepared by conventional impregnation methods.
Acid-Catalyzed Cyclization of Vinylsilanes Bearing a Hemiacetal Group
Authors: Miura Katsukiyo , Takahashi Tatsuyuki , Nishikori Hisashi , Hosomi Akira
Published: April 2003

In the presence of a catalytic amount of TsOH·H2O, hemiacetals derived from (Z)-4-trialkylsilyl-3-buten-1-ols and chloral were cyclized to 2-trichloromethyl-4-trialkylsilylmethyl-1,3-dioxanes in good to high yields. The substrates bearing an allylic substituent achieved high levels of 1,2-asymmetric induction. When the silyl group was a benzyldimethylsilyl group, the products could be efficiently converted to 1,2,4-triol derivatives by oxidative cleavage of the silicon–carbon bond.
Polar Assembly of 2,6-Diethynylpyridine through C(sp2)–H···N, C(sp)–H···π and π–π Stacking Interactions: Crystal Structure and Nonlinear Optical Properties
Authors: Ohkita Masakazu , Suzuki Takanori , Nakatani Keitaro , Tsuji Takashi
Published: April 2003

The crystallization of 2,6-diethynylpyridine 1 leads to C(sp2)–H···N hydrogen bonded head-to-tail tapes which are held together by C(sp)–H···π hydrogen bridges to form 2D polar sheets; further assembly through π–π stacking interaction results in 3D polar crystals which show intense powder SHG response, 5-fold stronger than crystalline urea.
π–π and σ–π Interactions in α,ω-Dinaphthyl and -Dianthryl Oligosilanes in Solution
Authors: Karatsu Takashi , Shibata Toshifumi , Nishigaki Atsuko , Fukui Keijiro , Kitamura Akihide
Published: April 2003

The π–π and σ–π interactions in α,ω-di-1-naphthyl and -di-9-anthryl oligosilanes [Np–(SiMe2)n–Np (1–4), Ant–(SiMe2)n–Ant (5–8), n = 1–4] were investigated in solution. In nonpolar solvents such as cyclohexane, a strong excimer fluorescence is observed, which indicates a strong π–π interaction. In a polar solvent (CH3CN), a charge-transfer (CT) emission is observed for 3 and 4 due to the σ–π interaction.
Rund um Kohlensäure
Authors: Kölle Ulrich
Published: April 2003

KOHLENSÄURE, eine Substanz in aller Munde, im direkten Sinne des Wortes, ist chemisch eine vertrackte, daher aber auch besonders interessante Spezies. Als Verbrennungsprodukt von Kohlenstoff und kohlenstoffhaltigen Substanzen ist das Kohlenstoffdioxid einer der ersten „chemischen Stoffe”︁, welche Schüler im Chemieunterricht kennen lernen und in Form von CO2, Carbonat und Hydrogencarbonat wird diese „Kohlensäure”︁ immer wieder auftauchen. Da könnte es sich lohnen, sie selber, H2CO3, einmal unter die Lupe zu nehmen.
Modellexperimente zum Gasbrenner und zur Wasserstrahlpumpe
Authors: de Vries Tönjes
Published: April 2003

ZU DEN WICHTIGSTEN GERÄTEN im Labor und auch im Chemieunterricht zählt zweifelsohne der Gasbrenner. Es wundert daher nicht, dass dessen Aufbau in nahezu allen Schulbüchern auf den ersten Seiten beschrieben wird. Auch im Chemie‐Anfangsunterricht erforschen Schüler begeistert mit Hilfe von Magnesia‐Stäbchen die unterschiedlichen Temperaturzonen in der Brennerflamme [vgl. 1]. Obwohl das Gerät einfach zu bedienen ist, wird das dahinter steckende Funktionsprinzip von Schülern oft nicht verstanden. Dieses liegt sicherlich darin begründet, dass der Weg des Erdgases durch den Brenner im wahrsten Sinne des Wortes nicht „durchschaubar”︁ ist. Es ist nur schwer erkennbar, dass sich durch die angesogene Luft im Brennerrohr ein Gas/Luft‐Gemisch bildet. In ähnlicher Weise verborgen ist auch die Funktionsweise der ebenfalls häufig im Unterricht eingesetzten Wasserstrahlpumpen 1).

Im vorliegenden Beitrag werden zunächst die beiden Geräten zugrunde liegenden strömungsphysikalischen Prinzipien beschrieben und auf Teilchenebene gedeutet. Anschließend werden Modellexperimente vorgestellt, die die Funktionsweise von Gasbrenner und Wasserstrahlpumpe veranschaulichen.
Geostatistical analysis of ground‐survey elevation data to elucidate spatial and temporal river channel change
Authors: Chappell Adrian , Heritage George L. , Fuller Ian C. , Large Andrew R. G. , Milan David J.
Published: April 2003

A digital elevation model (DEM) of a fluvial environment represented landform surface variability well and provided a medium for monitoring morphological change over time. Elevation was measured above an arbitrary datum using a ground‐based three‐dimensional tacheometric survey in two reaches of the River Nent, UK, in July 1998, October 1998 (after flood conditions) and June 1999. A detailed geostatistical analysis of the elevation data was used to model the spatial variation of elevation and to produce DEMs in each reach and for each survey period. Maps of the difference in elevation were produced and volumetric change was calculated for each reach and each survey period. The parameters of variogram models were used to describe the morphological character of each reach and to elucidate the linkages between process and the form of channel change operating at different spatial and temporal scales.

The analysis of channel change on the River Nent shows the potential of geostatistics for investigating the magnitude and frequency of geomorphic work in other rivers. A flood modified the channel features, but low magnitude and high frequency flows rationalized the morphology. In spite of relatively small amounts of net flux the channel features changed as a consequence of the reworking of existing material. The blocking of chute entrances and redirection of the channel had a considerable effect on the behaviour of the channel. Such small changes suggested that the distributary system was sensitive to variation in sediment regime.

Plots of the kriging variances against sampling intervals were used to quantify the temporal variation in sampling redundancy (ranging between −11 per cent and +93 per cent). These curves illustrated the importance of bespoke sampling designs to reduce sampling effort by incorporating anisotropic variation in space and geomorphic information on flow regime. Variation in the nugget parameter of the variogram models was interpreted as sampling inaccuracy caused by variability in particle size and is believed to be important for future work on surface roughness. Copyright © 2003 John Wiley & Sons, Ltd.
The importance of plant root characteristics in controlling concentrated flow erosion rates
Authors: Gyssels G. , Poesen J.
Published: April 2003

While it has been demonstrated in numerous studies that the aboveground characteristics of the vegetation are of particular importance with respect to soil erosion control, this study argues the importance of separating the influence of vegetation on soil erosion rates into two parts: the impact of leaves and stems (aboveground biomass) and the influence of roots (belowground biomass). Although both plant parameters form inseparable constituents of the total plant organism, most studies attribute the impact of vegetation on soil erosion rates mainly to the characteristics of the aboveground biomass. This triggers the question whether the belowground biomass is of no or negligible importance with respect to soil erosion by concentrated flow. This study tried to answer this question by comparing cross‐sectional areas of concentrated flow channels (rills and ephemeral gullies) in the Belgian Loess Belt for different cereal and grass plant densities. The results of these measurements highlighted the fact that both an increase in shoot density as well as an increase in root density resulted in an exponential decrease of concentrated flow erosion rates. Since protection of the soil surface in the early plant growth stages is crucial with respect to the reduction of water erosion rates, increasing the plant root density in the topsoil could be a viable erosion control strategy. Copyright © 2003 John Wiley & Sons, Ltd.
Flow hydraulics and geomorphic effects of glacial‐lake outburst floods in the Mount Everest region, Nepal
Authors: Cenderelli Daniel A. , Wohl Ellen E.
Published: April 2003

Glacial‐lake outburst floods (GLOFs) on 3 September 1977 and 4 August 1985 dramatically modified channels and valleys in the Mount Everest region of Nepal by eroding, transporting, and depositing large quantities of sediment for tens of kilometres along the flood routes. The GLOF discharges were 7 to 60 times greater than normal floods derived from snowmelt runoff, glacier meltwater, and monsoonal precipitation (referred to as seasonal high flow floods, SHFFs). Specific stream power values ranged from as low as 1900 W m−2 in wide, low‐gradient valley segments to as high as 51 700 W m−2 in narrow, high‐gradient valley segments bounded by bedrock. Along the upper 16 km of the GLOF routes, the reach‐averaged specific stream power of the GLOFs was 3·2 to 8·0 times greater than the reach‐averaged specific stream power of the SHFFs. The greatest geomorphic change occurred along the upper 10 to 16 km of the GLOF routes, where the ratio between the GLOF specific stream power and the SHFF specific stream power was the greatest, there was an abundant supply of sediment, and channel/valley boundaries consisted primarily of unconsolidated sediment. Below 11 to 16 km from the source area, the geomorphic effects of the GLOFs were reduced because of the lower specific stream power ratio between the GLOFs and SHFFs, more resistant bedrock flow boundaries, reduced sediment supply, and the occurrence of past GLOFs. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of halocarbons in the Tiber and Marta rivers by static headspace and liquid–liquid extraction analysis
Authors: Russo Mario V. , Campanella Luigi , Avino Pasquale
Published: April 2003

Volatile organochlorine compounds in the Tiber and Marta rivers have been analyzed by liquid–liquid extraction and headspace gas chromatography. Several different halogenated compounds were identified, in particular chloroform, bromoform, trichloroethane, trichloroethene, and tetrachloroethene. The concentrations of the halocarbons varied between 0.05 and 4.5 μg L–1 with a relative standard deviation ≤4.0%. The highest concentrations were observed for chloroform, bromoform, and tetrachloroethene in the Marta and Tiber rivers. The results obtained by use of the two analytical methods were similar.
CO/Alkene Copolymers as a Promising Class of Biocompatible Materials, 1. Examination of the In Vitro Toxicity
Authors: Reuter P. , Fuhrmann R. , Mücke A. , Voegele J. , Rieger B. , Franke R.‐P.
Published: April 2003

Novel 1,4‐polyketones were synthesized by a PdII catalyzed copolymerization reaction from cheap technical monomers. The spectrum of mechanical properties ranges from highly crystalline, hard materials to thermoplastic, soft elastomers. The hydrophilicity of the surface is adjustable from nonpolar to highly polar by a proper choice of the α‐olefin component. This control of polymer properties is a basis for the development of new biocompatible materials. The results of standardized as well as more specific in vitro tests clearly demonstrate the nontoxicity of the investigated copolymers.

Polyketone synthesis.

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Polyketone synthesis.
A Note on Analysis and Numerics for Radiative MHD in 3D
Authors: Dedner Andreas , Rohde Christian , Wesenberg Matthias
Published: April 2003

The equations of radiative magnetohydrodynamics describe the dynamics of an electrically conducting fluid interacting with magnetic fields and radiation. In particular they provide a widely accepted mathematical model for the physics in the solar photosphere and convection zone. In the spatially three‐dimensional case we present several notions of solutions for the Cauchy problem and discuss existence and uniqueness issues. Furthermore we report on numerical experiments in the context of solar physics.
Construction and complexity of hierarchical matrices
Authors: Grasedyck Lars , Hackbusch Wolfgang
Published: April 2003

In previous papers a class of ℋ︁‐matrices was introduced which are data‐sparse and allow an approximate matrix arithmetic of nearly optimal complexity. The complexity analysis for the (approximate) matrix arithmetics in the class of ℋ︁‐matrices is based on two criteria, the sparsity and the idempotency. We describe a general strategy for the construction of the ℋ︁‐matrices where the two criteria are fulfilled.
Stability Analysis of Full Annular Rub in Rotor‐to‐Stator Systems
Authors: Jiang Jun , Ulbrich Heinz
Published: April 2003

This paper outlines the analytical study of the stability of a more realistic rotor‐to‐stator contact model, which considers the stator as an elastic body having finite mass and being elastically supported. For this model, no report on the stability analysis is available in the literature by our knowledge. In this study, the analytical solution, corresponding to the synchronous full annular rub motion, is first solved, then the stability condition of it is derived. Based on the systematic parametric studies, one gains a deeper insight into the nature of the dynamical behavior of the rotor‐to‐stator contact system. Since the previously investigated simpler rotor‐to‐stator contact models are only the special cases of the present model, the limitation of the simpler models and the influence of the system parameters, which were omitted or assigned to specific values in the simpler models, have been revealed through the present investigation.
Nonlinear Controller Design for PWM–Controlled Converters
Authors: Kugi A. , Schlacher K.
Published: April 2003

This contribution is concerned with the nonlinear controller design for a certain class of PWM (pulse width modulation) – controlled converter systems. It will be shown that under certain assumptions the SSA (state space averaging) – model of the PWM–controlled converter with the duty ratio as the plant input has a very special mathematical structure. Based on this mathematical model a modified version of the nonlinear H2–design where an integral term is systematically included in the nonlinear controller will be presented.
Modelling and identification of rigid‐body dynamics of parallel kinematic structures
Authors: Grotjahn Martin
Published: April 2003

A new approach for modelling the dynamics of parallel kinematic (PKM) structures is presented in this paper. It leads to a formulation of the dynamic equations which is linear with respect to a dynamic parameter vector of minimal dimension. Thus, the equations can be directly used for parameter identi.cation by linear estimation techniques. The algorithm utilisesJourdain's principle of virtual power which leads to very efficient resulting code. The parameter reduction is based on opening the kinematic loops so that analytic rules known from serial robots can be implemented. Additionally, a new approach for dynamic parameter identification is suggested. The application to modelling the PKM PaLiDa and identifying its gravitational parameters proves the capacity of the presented approaches.
Asymptotic evaluation of effective complex moduli of fibre‐reinforced viscoelastic composite materials
Authors: Andrianov I. , Danishevs'kyy V. , Weichert D.
Published: April 2003

We propose an asymptotic approach for the evaluation of effective complex moduli of viscoelastic fibre‐reinforced composite materials. Our method is based on the homogenization technique. We start with a non‐trivial expansion of the input plane‐strain boundary value problem by ratios of visco‐elastic constants. This allows to simplify the governing equations to forms analogous to the complex transport problem. Then we apply the asymptotic homogenization method, coming from the original problem on multi‐connected domain to the cell problem, defined on a unit cell of the periodic structure. For the analytical solution of the cell problem we apply the boundary perturbation technique, the asymptotic expansion by a distance between two neighbouring fibres and the method of two‐point Padé approximants. As results we derive uniform analytical representations for effective complex moduli, valid for all values of the components volume fractions and properties.
On the construction of conservation laws with the Neutral Action Method
Authors: Nordbrock Uwe , Kienzler Reinhold
Published: April 2003

In constructing conservation laws, Noether's classical theorem can only be applied, if a Lagrangian function is available for the system of interest. A recently developed procedure, the so called Neutral‐Action Method, allows a systematic construction, even if no Lagrangian function exists.
Thermo–mechanical behaviour of steel including phase transitions and transformation–induced plasticity
Authors: Wolff Michael , Böhm Michael , Schmidt Alfred
Published: April 2003

In the framework of Rational Mechanics, we formulate a continuum‐mechanical model for the thermo‐mechanical behaviour of steel. Our plasticity model is based on the assumption of intermediate configurations. We include phase transitions, plasticity as well as transformation‐induced plasticity (TRIP) and allow for general material laws. Some consequences will be derived from the Clausius‐Duhem inequality. The resulting model is a system of strongly coupled PDE's for displacement, temperature and phase distributions. A quenching test is numerically simulated. This work has been partially supported by the DFG via the SFB 570 “Distortion Engineering”, University of Bremen.
Modelling of 3‐D Linear Viscoelastic Swelling of Charged Tissues and Gels
Authors: Ehlers Wolfgang , Acartürk Ayhan , Markert Bernd
Published: April 2003

The skeleton of hydrated tissues or gels exhibits flow‐independent viscoelastic properties [2] which are strongly coupled with the dissipative phenomena resulting from the interstitial fluid flow and the electrochemical swelling mechanisms [4]. Following this, it is the goal of this contribution to combine a linear viscoelasticity formulation with an electrochemical swelling theory in the framework of a well‐founded multiphasic concept. Proceeding from a macroscopic mixture approach, the governing equations can be expressed in terms of three primary variables, namely the solid displacement uS, the effective pore‐fluid pressure p and the molar salt concentration cm of the interstitial fluid.