bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐Constrained Sintering of Mixed Low‐Temperature‐Cofired Ceramic Laminates
Authors: Chang Jui‐Chuan , Jean Jau‐Ho
Published: May 2006

A self‐constrained low‐temperature‐cofired ceramic (LTCC) system, composed of a low‐fire La2O3–B2O3–CaO–Al2O3‐based glass (LBG)+alumina (LBGA) and high‐fire BaO–B2O3–SiO2‐based glass (BBSG)+alumina (BBSGA), has been developed. As the densification temperature range required for the LBGA is lower than that for the BBSGA, both systems densify and constrain alternatively during cofiring of a multilayer LBGA/BBSGA laminate. This results in the linear shrinkage of multilayer LBGA/BBSGA laminate taking place only in the Z direction with little shrinkage in the X–Y directions, exhibiting promising characteristics of self‐constrained densification.
Preparation of Y‐type Barium Hexaferrite by the Glass–Ceramic Method
Authors: Nagae Masahiro , Atsumi Takashi , Yoshio Tetsuo
Published: May 2006

Y‐type Ba‐hexaferrites (Ba2Zn2Fe12O22), which have been identified as electromagnetic wave absorbers, were prepared by the glass–ceramic method. Glasses with the composition 0.1ZnO·0.9(xB2O3·yBaO·(1−x−y)Fe2O3) were prepared, and the precipitation of Y‐type Ba‐hexaferrite from the glass matrix was investigated. Y‐type Ba‐hexaferrite were precipitated by heating glass specimens with roughly the composition 0.1ZnO·0.9(0.2B2O3·0.5BaO·0.3Fe2O3) at temperatures above about 1073 K. The lower temperature limit at which single‐phase Y‐type powder was obtained after leaching with a dilute HCl solution was about 1093 K. The low‐temperature formation of Y‐type Ba‐hexaferrite was linked to the generation of a liquid phase. The shape of Y‐type crystals depended strongly on the heating temperature and changed from a plate‐like hexagon to a complex polyhedron with increasing heating temperature.
Residual Stress and Microstructural Evolution in Environmental Barrier Coatings of Tantalum Oxide Alloyed with Aluminum Oxide and Lanthanum Oxide
Authors: Weyant C. M. , Faber K. T. , Almer J. D. , Guiheen J. V.
Published: May 2006

Pure Ta2O5 has been investigated as a possible environmental barrier coating (EBC) material for silicon nitride‐based ceramics, but was found to be inadequate because of localized buckling and the formation of microcracks. To address these issues, alloying additions were explored to improve some of the properties of Ta2O5 for this application. Aluminum oxide (Al2O3) was investigated to stabilize the low‐temperature β‐Ta2O5 phase and reduce grain growth in the coating through the formation of a solid solution. Lanthanum oxide (La2O3) was investigated as a second phase former designed to pin grain‐boundaries and reduce grain growth. High‐brilliance X‐rays at the Advanced Photon Source at Argonne National Laboratory were used to evaluate residual stress and phase evolution in the alloyed coatings. Scanning electron microscopy was used to study microstructural changes and grain growth. Al2O3 was successful at stabilizing β‐Ta2O5 and the Al2O3 and La2O3 significantly reduced grain growth in the coatings. Significant microcracking was observed in the coatings alloyed with Al2O3 after thermal cycling in air. Coatings alloyed with Al2O3 and La2O3 showed no evidence of microcracking. However, some of the alloyed coatings which were first thermally cycled in air and subsequently exposed to high‐temperature steam completely delaminated from the AS800 silicon nitride substrates, a highly undesirable result for an EBC.
Rheological Characterisation of Electrosterically Dispersed Alumina Suspensions During In Situ Coagulation
Authors: Binner Jon G.P. , Santacruz Isabel , McDermott Andrew M.
Published: May 2006

A near‐net shape route for the production of advanced ceramic components has been developed that uses carboxylic acid derivatives as coagulants to achieve the destabilization of electrosterically dispersed high solids content ceramic suspensions via pH modification driving the suspension towards its IEP. In the present work, the effect of the time‐dependent in situ hydrolysis of the coagulant, d‐gulonic‐γ‐lactone, on the progressive destabilization of the precursor suspension to form highly viscous pastes has been characterized rheologically. The macroscopically determined dynamic storage and loss modulii, G′ and G″, obtained during oscillatory investigations have been found to be sensitive rheological parameters that describe the structural changes occurring at a microscopic level within the material. The progression of coagulation has been found to be critically dependent on the coagulant concentration and suspension temperature. Increasing either of these variables greatly accelerates the extent and rate of coagulation. Furthermore, with judicious control over them, coagulation characteristics approaching idealized behavior can be obtained.
Facile Preparation of ZnTiO3 Ceramic Powders in Sodium/Potassium Chloride Melts
Authors: Xing Xianran , Zhang Caiyan , Qiao Lijie , Liu Guirong , Meng Jian
Published: May 2006

A facile molten salt synthesis route was developed to prepare ZnTiO3 ceramic powders with simple oxides ZnO and TiO2 using sodium and potassium chloride eutectic salts as flux. The role of calcination temperature and time and the amount of salt addition to ZnTiO3 formation was investigated by thermogravimetry‐differential thermal analysis, X‐ray diffraction and Fourier transformation‐infrared spectroscopy measurements. Pure hexagonal phase of ZnTiO3 could be obtained from the mixture of the simple oxides and the chlorides (50 mol% KCl, 20 times to oxides in molar ratio) heating at 800°C for 6 h. The scanning electron microscopy images revealed the products were hexagonal sheets of about 1–3 μm size. Increasing the amount of salt aids in reducing the crystal sizes of final ceramic powders because of diluting the solution.
Dispersion of Nano‐Sized γ‐Alumina Powder in Non‐Polar Solvents
Authors: Liu Jen‐Chieh , Jean Jau‐Ho , Li Chia‐Chen
Published: May 2006

To disperse nano‐sized γ‐alumina powders in non‐polar solvents, the surface of γ‐alumina has to be modified with unsaturated oleic acid, which forms aluminum‐oleate on the surface. This changes the surface characteristics of γ‐alumina powders from hydrophilic to hydrophobic in nature. A colloidally stable γ‐alumina non‐polar suspension is obtained when a critical amount of aluminum‐oleate compound is formed on the surface. This is also evidenced by the results of adsorption and theoretical calculation of potential energies, which confirm the colloidal stability of organic γ‐alumina suspension caused by the steric repulsion mechanism.
The Role of Material Chemistry in Processing BaTiO3 in Aqueous Suspensions
Authors: Adair J. H. , Crampo J. , Mandanas M. M. , Suvaci E.
Published: May 2006

The application of material chemistry concepts to processing powder suspensions including solution thermodynamics will be demonstrated on several material systems, notably the complex metal oxide, barium titanate, in aqueous environments. After a discussion of the relevant thermodynamic and kinetic issues for fine particles in liquids, various characterization approaches to understand and control the behavior of powders in liquids will be discussed. Various colloidal characterization techniques, high‐resolution TEM, and chemical analyses of both the solution and solid exposed to solution have been used to study the nature of the chemical reactions and subsequent altered surface layers in the barium titanate–water system. The key factor in developing an effective aqueous processing scheme for any water sensitive material (and all metal oxides are water sensitive) in aqueous suspension, is recognition that deleterious surface hydrolysis reactions must be prevented. It is shown that local chemical inhomogeneities play a role in abnormal grain growth in the barium titanate system exposed to aqueous environments, but can be controlled with appropriate chemical passivation approaches. The success of a passivation–dispersion approach in the aqueous processing of these materials will be discussed as well as the implementation of the general concept of material chemistry approaches to the aqueous processing of other water sensitive materials.
Constrained Sintering of Low‐Temperature Co‐Fired Ceramics
Authors: Mohanram Aravind , Lee Sang‐Ho , Messing Gary L. , Green David J.
Published: May 2006

This paper discusses the effect of uniaxial compressive stress and pressureless constraint on the microstructure, density, and shrinkage anisotropy during the sintering of two commercial low‐temperature co‐fired ceramic (LTCC) systems, i.e., Heraeus CT2000 (CT) and DuPont 951Tape (DU). Under uniaxial compression, the ratio of axial to transverse shrinkage of DU is significantly higher than that of CT. A simple linear viscous theory was used to estimate the change in the strain rates produced by the external stress and the stress required to produce zero shrinkage. The theory was found to overestimate the measured stress‐induced strain rates. The uniaxial compressive stress required for zero overall shrinkage was estimated to be ∼60 kPa for DU and 80 kPa for CT. The estimate for the DU materials was in good agreement with the experimental data, but there was significant deviation for the CT material. Higher viscosity and higher constraining stresses led to lower densities in pressure‐less constrained CT specimens compared with DU.
Cost effectiveness of brace, physiotherapy, or both for treatment of tennis elbow
Authors: Struijs P A A , Korthals-de Bos I B C , van Tulder M W , van Dijk C N , Bouter L M , Assendelft W J J
Published: May 2006

Background:The annual incidence of tennis elbow in the general population is high (1–3%). Tennis elbow often leads to limitation of activities of daily living and work absenteeism. Physiotherapy and braces are the most common treatments.

Objectives:The hypothesis of the trial was that no difference exists in the cost effectiveness of physiotherapy, braces, and a combination of the two for treatment of tennis elbow.

Methods:The trial was designed as a randomised controlled trial with intention to treat analysis. A total of 180 patients with tennis elbow were randomised to brace only (n  =  68), physiotherapy (n  =  56), or a combination of the two (n  =  56). Outcome measures were success rate, severity of complaints, pain, functional disability, and quality of life. Follow up was at six, 26, and 52 weeks. Direct healthcare and non-healthcare costs and indirect costs were measured. Mean cost differences over 12 months were evaluated by applying non-parametric bootstrap techniques.

Results:No clinically relevant or statistically significant differences were found between the groups. Success rate at 12 months was 89% in the physiotherapy group, 86% in the brace group, and 87% in the combination group. Mean total costs per patient were €2069 in the brace only group, €978 in the physiotherapy group, and €1256 in the combination group. The mean difference in total costs between the physiotherapy and brace group was substantial (€1005), although not significant. Cost effectiveness ratios and cost utility ratios showed physiotherapy to be the most cost effective, although this also was not statistically significant.

Conclusion:No clinically relevant or statistically significant differences in costs were identified between the three strategies.
Glutamate metabolism in HIV-infected macrophages: implications for the CNS
Authors: Porcheray Fabrice , Léone Cathie , Samah Boubekeur , Rimaniol Anne-Cécile , Dereuddre-Bosquet Nathalie , Gras Gabriel
Published: May 2006

Central nervous system disorders are still a common complication of human immunodeficiency virus (HIV) infection and can lead to dementia and death. They are mostly the consequences of an inflammatory macrophagic activation and relate to glutamate-mediated excitotoxicity. However, recent studies also suggest neuroprotective aspects of macrophage activation through the expression of glutamate transporters and glutamine synthetase. We thus aimed to study whether HIV infection or activation of macrophages could modulate glutamate metabolism in these cells. We assessed the effect of HIV infection on glutamate transporter expression as well as on glutamate uptake by macrophages and showed that glutamate transport was partially decreased in the course of virus replication, whereas excitatory amino acid transporter-2 (EAAT-2) gene expression was dramatically increased. The consequences of HIV infection on glutamine synthetase were also measured and for the first time we show the functional expression of this key enzyme in macrophages. This expression was repressed during virus production. We then quantified EAAT-1 and EAAT-2 gene expression as well as glutamate uptake in differentially activated macrophages and show that the effects of HIV are not directly related to pro- or anti-inflammatory mediators. Finally, this study shows that glutamate transport by macrophages is less affected than what has been described in astrocytes. Macrophages may thus play a role in neuroprotection against glutamate in the infected brain, through their expression of both EAATs and glutamine synthetase. Because glutamate metabolism by activated macrophages is sensitive to both HIV infection and inflammation, it may thus be of potential interest as a therapeutic target in HIV encephalitis.
Encoding of Naturalistic Optic Flow by a Population of Blowfly Motion-Sensitive Neurons
Authors: Karmeier K. , van Hateren J. H. , Kern R. , Egelhaaf M.
Published: May 2006

In sensory systems information is encoded by the activity of populations of neurons. To analyze the coding properties of neuronal populations sensory stimuli have usually been used that were much simpler than those encountered in real life. It has been possible only recently to stimulate visual interneurons of the blowfly with naturalistic visual stimuli reconstructed from eye movements measured during free flight. Therefore we now investigate with naturalistic optic flow the coding properties of a small neuronal population of identified visual interneurons in the blowfly, the so-called VS and HS neurons. These neurons are motion sensitive and directionally selective and are assumed to extract information about the animal's self-motion from optic flow. We could show that neuronal responses of VS and HS neurons are mainly shaped by the characteristic dynamical properties of the fly's saccadic flight and gaze strategy. Individual neurons encode information about both the rotational and the translational components of the animal's self-motion. Thus the information carried by individual neurons is ambiguous. The ambiguities can be reduced by considering neuronal population activity. The joint responses of different subpopulations of VS and HS neurons can provide unambiguous information about the three rotational and the three translational components of the animal's self-motion and also, indirectly, about the three-dimensional layout of the environment.
Micromechanics of Smart Composite Plates with Periodically Embedded Actuators and Rapidly Varying Thickness
Authors: Kalamkarov A. L. , Georgiades A. V. , Challagulla K. , Saha G. C.
Published: May 2006

Asymptotic homogenization models for smart composite plates with periodically arranged embedded actuators and rapidly varying thickness are derived. The formulated models enable the determination of both local fields and effective elastic, actuation, thermal expansion, and hygroscopic expansion coefficients from three-dimensional local unit cell problems. The actuation coefficients, for example piezoelectric or magnetostrictive, characterize the intrinsic transducer nature of active smart materials that can be used to induce strains and stresses in a coordinated fashion. The theory is illustrated by means of examples pertaining to thin smart composite plates of uniform thickness, riband waferreinforced smart composite structures, and sandwich smart composite plates with honeycomb filler.
Pole-Placement Vibration Control of a Flexible Composite I-beam using Piezoceramic Sensors and Actuators
Authors: Sethi V. , Song G.
Published: May 2006

This article concerns active vibration control of a flexible 3.35-m long composite I-beam that is used in civil structures in a cantilevered configuration by using piezoceramic materials, in particular the PZT (lead zirconate titanate), in the form of patches. These PZT patches are surface-bonded on the I-beam and function as actuators and sensors. A real time data acquisition and control system is used to record the experimental data and to implement controllers. To assist the control system design, open loop testing and system identification are conducted. A pole-placement controller is designed and is simulated using the identified model. Simulations show a dramatic increase in damping of the beam. Experimental results verify the simulated results and demonstrate the effectiveness of active control of a civil structure using smart materials.
The fading of reported effectiveness. A meta-analysis of randomised controlled trials
Authors: Gehr Bernhard T , Weiss Christel , Porzsolt Franz
Published: May 2006

Background

The "real" effect size of a medical therapy is constant over time. In contrast, the effect size reported in randomised controlled trials (RCTs) may change over time because the sum of all kinds of bias influencing the reported effectiveness is not necessarily constant. As this would affect the validity of meta-analyses, we tested the hypothesis that the reported effect size decreases over time. Furthermore, we tested three hypotheses that would explain a possible change.

Methods

Because of well established outcome measures, the lipid-lowering drugs Pravastatin and Atorvastatin (serum low-density lipoprotein cholesterol, LDL-C) and the anti-glaucoma drugs Timolol and Latanoprost (intraocular pressure, IOP) were chosen for this investigation. Studies were identified by a standardized MEDLINE search. RCTs investigating the above identified medications administered as monotherapy, and in defined dosages, were included. Publication year, baseline (= pre-treatment value in the treatment group of interest) and post intervention means, number of patients and the assignment to experimental or control group were extracted for each study.

Results

A total of 625 citations were screened; 206 met the inclusion criteria. The reported effect size of Pravastatin (change of reported effect size in five years: -3.22% LDL-C, P < .0001), Timolol (-0.56 mmHg, P < .0001) and Latanoprost (-1.78 mmHg, P = .0074) decreased over time, while there was no significant change for Atorvastatin (+0.31% LDL-C, P = .8618). Multiple regression analysis showed that baseline values were the most important influencing factor; study size or treatment group did not play a significant role.

Conclusion

The effectiveness of medical therapies reported in RCTs decreases over time in three of the four investigated pharmaceuticals, caused mainly by baseline differences. We call this phenomenon "fading of reported effectiveness". Under this condition the validity of a meta-analysis may be impaired. Therefore we propose to observe this phenomenon in future meta-analyses in order to guarantee a maximum of transparency.
Ontogenetic variations in the venom proteome of the Amazonian snake Bothrops atrox
Authors: Guércio Rafael AP , Shevchenko Anna , Shevchenko Andrej , López-Lozano Jorge L , Paba Jaime , Sousa Marcelo V , Ricart Carlos AO
Published: May 2006

Background

Bothrops atrox is responsible for the majority of snakebite accidents in the Brazilian Amazon region. Previous studies have demonstrated that the biological and pharmacological activities of B. atrox venom alter with the age of the animal. Here, we present a comparative proteome analysis of B. atrox venom collected from specimens of three different stages of maturation: juveniles, sub-adults and adults.

Results

Optimized conditions for two-dimensional gel electrophoresis (2-DE) of pooled venom samples were achieved using immobilized pH gradient (IPG) gels of non-linear 3–10 pH range during the isoelectric focusing step and 10–20% gradient polyacrylamide gels in the second dimension. Software-assisted analysis of the 2-DE gels images demonstrated differences in the number and intensity of spots in juvenile, sub-adult and adult venoms. Although peptide mass fingerprinting (PMF) failed to identify even a minor fraction of spots, it allowed us to group spots that displayed similar peptide maps. The spots were subjected to a combination of tandem mass spectrometry and Mascot and MS BLAST database searches that identified several classes of proteins, including metalloproteinases, serine proteinases, lectins, phospholipases A2, L-amino oxidases, nerve growth factors, vascular endothelial growth factors and cysteine-rich secretory proteins.

Conclusion

The analysis of B. atrox samples from specimens of different ages by 2-DE and mass spectrometry suggested that venom proteome alters upon ontogenetic development. We identified stage specific and differentially expressed polypeptides that may be responsible for the activities of the venom in each developmental stage. The results provide insight into the molecular basis of the relation between symptomatology of snakebite accidents in humans and the venom composition. Our findings underscore the importance of the use of venoms from individual specimen at various stages of maturation for the production of antivenoms.
Hospitalisation among immigrants in Italy
Authors: Cacciani Laura , Baglio Giovanni , Rossi Lorenza , Materia Enrico , Marceca Maurizio , Geraci Salvatore , Spinelli Angela , Osborn John , Guasticchi Gabriella
Published: May 2006

Background

Immigration is increasing in Italy. In 2003, 2.6 million foreign citizens lived in the country; 52% were men and the majority were young adults who migrated for work. The purpose of this study was to investigate differences in hospitalisation between immigrants and the resident population during the year 2000 in the Lazio region.

Methods

Hospital admissions of immigrants from Less Developed Countries were compared to those of residents. We measured differences in hospitalisation rates and proportions admitted.

Results

Adult immigrants have lower hospitalisation rates than residents (134.6 vs. 160.5 per thousand population for acute care; 26.4 vs. 38.3 for day care). However, hospitalisation rates for some specific causes (injuries, particularly for men, infectious diseases, deliveries and induced abortions, ill-defined conditions) were higher for immigrants than for residents. Immigrants under 18 years seem to be generally healthy; causes of admission in this group are similar to those of residents of the same age (respiratory diseases, injuries and poisoning). The only important differences are for infectious and parasitic diseases, with a higher proportion among immigrant youths.

Conclusion

The low hospitalisation rates for foreigners may suggest that they are a population with good health status. However, critical areas, related to poor living and working conditions and to social vulnerability, have been identified. Under-utilisation of services and low day care rates may be partially due to administrative, linguistic, and cultural barriers. As the presence of foreigners becomes an established phenomenon, it is important to evaluate their epidemiological profile, develop instruments to monitor and fulfil their specific health needs and plan health services for a multi-ethnic population.
Issues of informed consent for intrapartum trials: a suggested consent pathway from the experience of the Release trial [ISRCTN13204258]
Authors: Vernon Gillian , Alfirevic Zarko , Weeks Andrew
Published: May 2006

Service users within the NHS are increasingly being asked to participate in clinical research. In Liverpool Women's NHS Foundation Trust, approximately 35% of women take part in research during their pregnancy. For many studies the consent process is simple; information is provided and signed consent is given. There is a difficulty, however, with obtaining informed consent from women in pregnancy who become eligible only when they develop unforeseen complications, especially when they occur acutely. The problem is compounded with women in labour who may be frightened, vulnerable, in pain, under the effect of opiate analgesia, or all of the above. If research to improve the care of these women is to continue, then special consent procedures are needed. These procedures must ensure that the woman's autonomy is protected whilst recognising that women under these circumstances vary enormously, both in their desire for information and their ability to comprehend it. This paper will discuss the obtaining of consent in this situation, and describe an information and consent pathway for intrapartum research which has been developed in collaboration with consumer groups as a way in which these issues can be tackled.
Robo1 regulates the development of major axon tracts and interneuron migration in the forebrain
Authors: Andrews William , Liapi Anastasia , Plachez Céline , Camurri Laura , Zhang Jiangyang , Mori Susumu , Murakami Fujio , Parnavelas John G. , Sundaresan Vasi , Richards Linda J.
Published: May 2006

The Slit genes encode secreted ligands that regulate axon branching,commissural axon pathfinding and neuronal migration. The principal identified receptor for Slit is Robo (Roundabout in Drosophila). To investigate Slit signalling in forebrain development, we generated Robo1 knockout mice by targeted deletion of exon 5 of the Robo1 gene. Homozygote knockout mice died at birth, but prenatally displayed major defects in axon pathfinding and cortical interneuron migration. Axon pathfinding defects included dysgenesis of the corpus callosum and hippocampal commissure, and abnormalities in corticothalamic and thalamocortical targeting. Slit2 and Slit1/2 double mutants display malformations in callosal development, and in corticothalamic and thalamocortical targeting, as well as optic tract defects. In these animals, corticothalamic axons form large fasciculated bundles that aberrantly cross the midline at the level of the hippocampal and anterior commissures,and more caudally at the medial preoptic area. Such phenotypes of corticothalamic targeting were not observed in Robo1 knockout mice but,instead, both corticothalamic and thalamocortical axons aberrantly arrived at their respective targets at least 1 day earlier than controls. By contrast, in Slit mutants, fewer thalamic axons actually arrive in the cortex during development. Finally, significantly more interneurons (up to twice as many at E12.5 and E15.5) migrated into the cortex of Robo1 knockout mice,particularly in both rostral and parietal regions, but not caudal cortex. These results indicate that Robo1 mutants have distinct phenotypes,some of which are different from those described in Slit mutants, suggesting that additional ligands, receptors or receptor partners are likely to be involved in Slit/Robo signalling.
Langmuir–Blodgett Films of Ferrocene Sulfide and Sulfone Derivatives with a Long Alkyl Chain
Authors: Li Jin-ru , Liu Ming-hua , Nakahara Hiroo , Sato Masaru , Fukuda Kiyoshige
Published: May 2006

With ferrocenyl octadecyl sulfide, stable monolayers on water surface can be obtained by mixing with stearic acid or by oxidizing to the sulfone derivative and can be easily deposited on solid supports to form well-organized LB films, as confirmed by polarized IR spectra and X-ray diffraction. The LB films exhibit electrochemical activity.
Novel Carbinolamine Complex Derived from Ketomalonate and trans-[CoCl2(3,7-Diaza-1,9-diaminononane)]+. Synthesis and Characterization of [Co(N-(3,7-Diaza-9-aminononyl)-α-amino-α-hydroxymalonato)] ClO4·H2O
Authors: Kojima Takahiko , Usui Takeshi , Yashiro Morio , Kuroda Reiko , Yano Shigenobu , Yoshikawa Sadao , Hidai Masanobu
Published: May 2006

A novel carbinolamine complex, [Co(N-(3,7-diaza-9-aminononyl)-α-amino-α-hydroxymalonato)]+, was obtained from the reaction of ketomalonic acid and trans-[CoCl2(2,3,2-tet)]+ and the molecular structure was determined by X-ray analysis. A free OH group in the carbinolamine linkage had aromatic properties despie it binds to an sp3 carbon.
Synthesis, Conformation, and the Stereoselective Sulfur Extrusion Reaction of a New Intraannular Dibromo-Substituted Tetrathia[4.4]metacyclophane
Authors: Fujihara Hisashi , Chiu Jer-Jye , Furukawa Naomichi
Published: May 2006

The oxidative coupling of 2,6-bis(mercaptomethyl)bromobenzene using I2 gave syn- and anti-10,20-dibromo-2,3,12,13-tetrathia[4.4]metacyclophane (1) which can be isolated in the solid state at room temperature. The sulfur extrusion reaction of anti-1with (Et2N)3P afforded the corresponding dithia[3.3]metacyclophane, while syn-1 gave the trithia[3.4]metacyclophane.
Catalytic Activity for NO Decomposition of Cobalt Tetrapropoxyphthalocyanine Supported on Titania
Authors: Fujitsu Hiroshi , Sakakihara Toshiaki , Mochida Isao
Published: May 2006

Cobalt-tetrapropoxyphthalocyanine, CoPc(OPr)4, impregnated with THF onto TiO2 provided an anion radical (g value: 2.003) which gave a stationary NO(500 ppm) conversion of 27% in a flow reaction without oxygen at 423 K. Oxygen in the reactant gas increased the conversion to 55%, which decreased gradually to the stationary 27% without any formation of NC2 or CC2.
Novel Flow Injection Method for Selective Spectrophotometric Determination of Acetylcholine Using Thermochromism of Ion Associates
Authors: Sakai Tadao , Gao Yun-hua , Ohno Noriko , Ura Nobuo
Published: May 2006

A selective and rapid spectrophotometric method for the determination of acetylcholine has been developed by flow injection technique coupled with ion pair extraction using tetrabromophenolphthalein ethyl ester dichloroethane solution, where selectivity can be improved by using both higher pH(pH 11) on extraction and thermochromism of ion associates in a flow system.
Stereo-Specific Binding of Dinuclear Copper(II) Complex of l-Carnosine with DNA
Authors: Chikira Makoto , Mizukami Yoichiro
Published: May 2006

EPR spectra of the title complex in DNA fibers revealed that the complex binds to the DNA with a specific orientation keeping its dinuclear structure unchanged from that in solution. The binding structure has been estimated from an angular dependence of the triplet-state EPR intensity.
High-Temperature Steam Reforming of Hydrocarbons over Nickel/Hexaaluminate Catalysts
Authors: Machida Masato , Teshima Takahiro , Eguchi Koichi , Arai Hiromichi
Published: May 2006

Hexaaluminate supports effectively suppressed the sintering of supported Ni particles and the carbon deposition in the steam reforming reaction. These prominent features result from a large surface area of the hexaaluminate support in the presence of high-temperature water vapor.
Mn3+-Mediated Coupling-Cyclization of 5-Arylpent-1-enes with Active Methylene Compounds by Electrooxidation
Authors: Shundo Ryushi , Nishiguchi Ikuzo , Matsubara Yoshiharu , Hirashima Tsuneaki
Published: May 2006

Selective coupling-cyclization of 5-arylpent-1-enes with active methylene compounds was developed by indirect electrooxidation using a small amount of Mn(OAc)2·4H2O to give 1-[2,2-(disubstituted)ethyl]tetralines in good yields.
Electronic Spectrum of Jet-Cooled Tropolone-3-d
Authors: Sekiya Hiroshi , Nagashima Yusuke , Nishimura Yukio , Mori Akira , Takeshita Hitoshi
Published: May 2006

The laser fluorescence excitation spectrum of jet-cooled tropolone-3-d has been measured to investigate the effect of an unsymmetrical substitution of a deuterium on proton tunneling and the equilibrium geometry.
A New Synthesis of (E)-1-Alkyl-1-trimethylsilylpropenes via Hydroboration of 3-Chloro-1-trimethylsilylpropyne with Dialkylboranes
Authors: Hoshi Masayuki , Masuda Yuzuru , Arase Akira
Published: May 2006

The successive treatment of 3-chloro-1-trimethylsilylpropyne with dialkylboranes and aqueous sodium hydroxide provided (E)-1-alkyl-1-trimethylsilylpropenes whose alkyl groups were derived from a terminal or internal alkene via dialkylboranes.
Reactions of Meso-ionic Compounds with Metal Complexes. Formation of (η5-Cyclopentadienyl)(1,2-diaryl-1,2-ethylenedithiolato)cobalt(III) Complexes in the Thermal and Photochemical Reactions of 2,5-Diaryl-1,3-dithiolylium-4-olate with [Co(cp)] Species
Authors: Sugimori Akira , Matsudaira Yorimasa , Tono Masaki , Kajitani Masatsugu , Akiyama Takeo , Sugiyama Toru
Published: May 2006

The title meso-ionic compounds react thermally and photochemically with [Co(cp)] species to give dithiolatocobalt complexes. 5-Phenyl-2-(p-tolyl)-1,3-dithiolylium-4-olate gives (η5-cyclopentadieny)(1-phenyl-2-(p-tolyl)-1,2-ethylenedithiolato)cobalt(III) with high selectivity.
Molecular and Crystal Structures of 5-Nitrofuran-2-aldoxime and Thiophene Analogues as SHG Materials
Authors: Matsuoka Masaru , Furukawa Masayoshi , Takao Mitsukazu , Kitao Teijiro , Hamada Masayuki , Nakatsu Kazumi
Published: May 2006

5-Nitrofuran-2-aldoxime (1b) exhibits crystallographic polymorphism. The isolated two crystals show SHG efficiency of 12 and 3 times that of urea. 5-Nitrothiophene-2-aldoxime (2b) shows weak SHG response because of the hyper valent interactions of O–S–O atoms. Two crystals of 1b and 2b belong to P212121 space group.
New Observation of 5-Coordinate Dinuclear Complexes with 1,1,2,2-Tetraacetylethanate and N-Alkylated Diethylenetriamine
Authors: Kambayashi Hide , Masuda Yuichi , Fukuda Yutaka
Published: May 2006

Seven dinuclear mixed ligand complexes of Ni(II) and Cu(II) containing tetraketonate (taet) and pentamethyldiethylenetriamine (Me5dien) were synthesized, M2(taet)(Me5dien)2X2·nH2O. The structures of these dinuclear complexes change between 5-coordinate (C4v–C4v) and 6-coordinate (Oh–Oh) ones depending upon the anion coordinating power and the metal ions used.
Copper-Induced Deselenative Coupling of Selenoamides Leading to 1,2-Enediamines
Authors: Sekiguchi Masahito , Ogawa Akiya , Kambe Nobuaki , Sonoda Noboru
Published: May 2006

N,N-Disubstituted selenoamides were found to undergo deselenative coupling by the action of copper(0), providing 1,2-enediamines in good yields. The driving force of this reaction may be a high affinity of selenium for soft metals such as copper.
A Novel Synthesis of Lactones by the Oxidation of Alicyclic Ketones with Oxone in Aprotic Solvent in the Presence of “Wet-Alumina”
Authors: Hirano Masao , Oose Masaki , Morimoto Takashi
Published: May 2006

Oxidation of cycloalkanones with Oxone in dichloro methane in the presence of “wet-alumina” afforded lactones in good yield under mild conditions.
Growth of Gd2SiO5 Crystals from MF (M = Li, Na, and K) Fluxes
Authors: Oishi Shuji , Hirao Minoru
Published: May 2006

The growth of Gd2SiO5. crystals from MF (M = Li, Na, and K) fluxes was attempted by a slow cooling method. Crystals of Gd2SiO5 were grown from LiF and KF fluxes. Well-formed Gd2SiO5 crystals up to 0.4 mm long were grown from KF flux. Unwanted NaGdSiO4 crystals were grown from NaF flux.
Ab Initio MO Study of the Reaction of Pentacoordinate Allylsilicates with Aldehydes
Authors: Kira Mitsuo , Sato Kazuhiko , Sakurai Hideki , Hada Masahiko , Izawa Masaru , Ushio Jiro
Published: May 2006

Transition state structures for the reaction of allyltetrafluorosilicate with formaldehyde as well as structures of the silicate and related compounds were located with ab initio MO calculations. The origin of the unique reactivity of pentacoordinate allylsilicates observed experimentally is discussed on this basis.
Microemulsion Capillary Electrophoresis
Authors: Watarai Hitoshi
Published: May 2006

Microemulsion capillary electrophoresis, which employed oil in water microemulsions as the electrophoretic media was demonstrated for the separation of ionic and non-ionic samples.
Langmuir–Blodgett Films of Polyacrylic Acid Modified with Perfluoroalkyl Groups
Authors: Tamura Masanori , Sekiya Akira
Published: May 2006

Long chain perfluoroalkyl groups were introduced to polyacrylic acid, and Langmuir–Blodgett films of the polymers were successfully prepared. The preparation of the polymer LB films containing metal ions was achieved by spreading the polymer solution on the aqueous solution of metal salt. Characterization of the films was attempted.
Cocation Effect in Catalytic Property of Copper Ion-Exchanged ZSM-5 Zeolites for the Direct Decomposition of Nitrogen Monoxide
Authors: Kagawa Shuichi , Ogawa Hiroshi , Furukawa Hiroshi , Teraoka Yasutake
Published: May 2006

The coexistence of metal cations such as alkaline earth and transition metal cations with Cu ions in ZSM-5 zeolites promoted the catalytic activity of Cu ion for the direct decomposition of nitrogen monoxide at temperatures above 450 °C. The promotion effect was found to depend on the ion exchange mode.
Thermotropic Liquid-Crystalline Ionic Polymers
Authors: Ujiie Seiji , Iimura Kazuyoshi
Published: May 2006

Thermotorpic liquid-crystalline ionic polymers formed between the anionic polymer and the cationic low-mass compound have been prepared, and their thermal properties and orientational structures have been studied. They spontaneously organized homeotropic structures in the smectic phases.
Addition Reactions of Cation Radicals of Nitroalkanes to Olefinic Compounds by the Use of Manganese(III) 2-Pyridinecarboxylate
Authors: Narasaka Koichi , Iwakura Kazunori , Okauchi Tatsuo
Published: May 2006

Silyl derivatives of aci-nitroalkanes react with olefins such as silyl enol ether, vinyl sulfide, and enamine by oxidation with manganese(III) 2-pyridinecarboxylate to give the intermolecular addition products selectively.
Calicoferols A and B, Two Novel Secosterols Possessing Brine-Shrimp Lethality from the Gorgonian Calicogorgia sp.
Authors: Ochi Masamitsu , Yamada Koji , Kotsuki Hiyoshizo , Shibata Kozo
Published: May 2006

The structures of calicoferols A and B, two new secosterols possessing brine-shrimp lethality isolated from the gorgonian Calicogorgia sp. have been determined on the basis of spectroscopic and chemical evidence.
Acyclic Oxy-Cope Rearrangement. Dependence of E/Z Stereoselection on Substrate Stereochemistry
Authors: Tomooka Katsuhiko , Wei Shih-Yi , Nakai Takeshi
Published: May 2006

The E/Z stereoselection in the acyclic oxy-Cope rearrangement of stereochemically-defined 3-methyl-1,5-heptadien-4-ols, prepared via diastereoselective [2,3]Wittig variants, has been evaluated, thereby permitting to propose a reasonable transition-state model for this type of anionic oxy-Cope variant.
Chirality Recognition by a Color Change in Crowned Cholesteric Liquid Crystals
Authors: Shinkai Seiji , Nishi Tadahiko , Matsuda Tsutomu
Published: May 2006

Alkali (R)- and (S)-mandelates can change the helical pitch of cholesteric liquid crystals containing steroidal crown ethers in an enantioselective manner. In certain cases the pitch difference between (R)- and (S)-mandelates can be detected visually as a color change in the liquid crystals.
Synthesis of (E)-2-Styrylchromones
Authors: Cavaleiro José A S , Elguero José , Jimeno M Luísa , Silva Artur M S
Published: May 2006

A new synthesis of (E)-2-styrylchromones has been developed in paralell with synthetic studies on several flavone derivatives.
Nature of the Effect of Counter Cations on the Redox Property of 12-Molybdophosphates
Authors: Kim Hee Chul , Moon Sang Heup , Lee Wha Young
Published: May 2006

The role of counter cations of 12-molybdophosphates in determining the redox property of the catalysts has been studied systematically. It is suggested that the electronegative cations act as large electron reservoirs to facilitate electron transfer in the redox process, as supported by the XPS results.
Isophenoxazine Synthase Model. Oxidation of o-Aminophenol by an Oxidation-Active Flavin Mimic in an Aqueous Solution
Authors: Yano Yumihiko , Ikuta Masato , Amamiya Yoshiyuki , Nabeshima Tatsuya
Published: May 2006

It was found that a flavin mimic, benzo-dipteridine (BDP), oxidizes o-aminophenol in an aqueous solution under anaerobic conditions. Under aerobic conditions, 2-aminophenoxazine-3-one was isolated. This is the first example of an isophenoxazine synthase model.
Selective Synthesis of Cellulose-Type Copolymers by Ring-Opening Copolymerization of 1,4-Anhydro-α-D-ribopyranose Derivatives
Authors: Yoshida Takashi , Song Lixin , Wu Cheng Pei , Hatanaka Kenichi , Uryu Toshiyuki
Published: May 2006

Stereoregular cellulose-type copoymers, (1→4)-β-D-ribopyranan derivatives, were prepared by selective ring-opening copolymerization of 1,4-anhydro-2,3-O-benzylidene- and -2,3-di-O-t-butyldimethylsilyl-α-D-ribopyranoses with antinomy pentachloride as catalyst at 0 °C. Being subjected to branching reaction, the copolymer can be converted into branched (1→4)-β-D-ribopyranans.
Facile Synthesis of Regioselectively Deuteriated (3R)-(−)-[8,8,8-2H3]Linalool
Authors: Hiraga Yoshikazu , Izumi Shunsuke , Hirata Toshifumi , Suga Takayuki
Published: May 2006

Regloseleetively deuteriated (3R)-(−)-[8,8,8-2H3] linalool was synthesized from (4R)-(−)-4-acetyl-3-methyl-5-hexenal, which was prepared from (3R)-(−)-linalyl acetate, with the synthesis of (2E,6R)-(−)-2,6-dimethyl-2,7-[1,1-2H2]octadiene-1,6-diol as the key step.
Transformation of Electronic Structure of Diaryldiazomethane Radical Cations as Studied by Cyclic Voltammetry
Authors: Ishiguro Katsuya , Ikeda Masatoshi , Sawaki Yasuhiko
Published: May 2006

The anodic oxidation of diaryldiazomethanes has been studied by cyclic voltammetry in CH2Cl2 at low temperature. It is shown that the initially formed π-radical cations are converted to σ-radical cations, which have a more negative reduction potential. The rate constant for the transformation of π- to σ-radicals could be determined for the typical case of dimesityldiazomethane by means of digital simulation of the cyclic voltammogram.
Stereoregulation in the Alternating Copolymerization Giving Highly Coheterotactic Poly(Methyl Methacrylate-alt-Styrene). Direct Determination of Coisotactic Parameters
Authors: Gotoh Yaeko , Yamashita Mihoko , Nakamura Masato , Toshima Naoki , Hirai Hidefumi
Published: May 2006

Coisotactic parameters of two steps in a propagating process, one from styrene (St) unit to methyl methacrylate (MMA) unit and the other from MMA unit to St unit, were experimentally determined in alternating copolymerization of MMA with St under the copolymerization conditions giving highly coheterotactic poly(MMA-alt-St). The former step resulted in highly syndiotactic addition and the latter, in highly isotactic addition.
A Chiral Total Synthesis of (−)-Physostigmine
Authors: Node Manabu , Hao Xiao-jiang , Fuji Kaoru
Published: May 2006

A chiral total synthesis of (−)-physostigmine via (−)-eserethole has been achieved starting from (S)-(−)-2-methyl-2-(2′-nitrovinyl)-δ-valerolactone.
Oxidation of Thymidine by Peroxomono- and Peroxodisulfate Ions
Authors: Itahara Toshio , Koga Sunao
Published: May 2006

Oxidation of thymidine by KHSO5 gave thymidine glycols, while a similar treatment with Na2S2O8 gave 5-hydroxymethyl-2′-deoxyuridine.
Cyclohexane Inclusion Compound with 2,2-Dibutyl-N,N′-di(1-naphthyl)malonamide
Authors: Hiratani Kazuhisa , Goto Midori
Published: May 2006

A novel clathrate-type inclusion compound has been formed from recrystallization of 2,2-dibutyl-N,N′-di(1-naphthyl)malonamide with restricted organic molecules, which was characterized by the thermal analyses (DSC and TGA) and the X-ray structural analysis.
Ex Situ Observation of Electrochemically Hydrogenated Palladium Using a Scanning Tunneling Microscope
Authors: Ohmori Takashi , Sakamaki Kenji , Hashimoto Kazuhito , Fujishima Akira
Published: May 2006

Morphological transformations were observed ex situ on a palladium (Pd) surface induced by electrochemically absorbed hydrogen using a scanning tunneling microscope (STM). Hydrogenated Pd exhibited β-phase and hydrogen absorption into Pd transformed the surface into a more detailed, nodular-like structure.
Indirect complexometric determination of mercury(II) in synthetic alloys and complexes using ethanethiol as a selective masking agent
Authors: Karthikeyan J. , Parameshwara P. , Shetty Nityananda , Shetty Prakash
Published: May 2006

Acomplexometric method for the determination of mercury(II) in presence of other metal ions, based on the selective masking action of ethanethiol towards mercury( II) is described. Mercury(II) present in a given sample solution is first complexed with an excess of EDTAand the unreacted EDTAis titrated against zinc sulphate solution at pH 5-6 (hexamine buffer) using xylenol orange as the indicator. An excess of a 0.3 % solution of ethanethiol is then added to displace EDTA from the Hg(II)-EDTA complex. The released EDTAis titrated with a standard zinc sulphate solution. Reproducible and accurate results are obtained for 4-85 mg of mercury(II) with a relative error of less than +-0.46 % and coefficient of variation of not more than 0.47 %. The effects of the presence of various ions were studied. The method can be used for the analysis of mercury in its synthetic alloy mixtures and also in complexes.
Effect of Sr on the properties of Ce-Zr-La mixed oxides
Authors: Rao Richuan , Lianyong LI , Fengyi LI
Published: May 2006

Ce-Zr-La-Sr mixed oxides, with different Sr contents, were prepared by the sol-gel method. In a flow-system microreactor, the reduction properties and the oxygen storage capacity (OSC) of the Ce-Zr-La-Sr mixed oxides were investigated by a temperature programmed reduction (TPR) and a pulse technique. It was shown that the properties of the Ce-Zr-La mixed oxides depend on the Sr content and that the optimum Sr content in the Ce-Zr-La-Sr mixed oxide is 3 mol%. The Ce-Zr-La-Sr mixed oxides doped with 3 mol% Sr (Ce0.52Zr0.4La0.05Sr0.03O1.945) has the largest specific surface area and better reduction properties and oxygen storage capacity in comparison to the other investigated samples. The XRD results of the Ce-Zr-La-Sr mixed oxides showed that their X-ray diffraction patterns are well in agreement with that of fluorite-type CeO2 with Sr ions incorporated into the Ce-Zr-La mixed oxide structures. With increasing calcination temperature, the intensity of the X-ray diffraction peaks increased, but no new peaks were observed. All of these indicate that the synthesized samples had good thermal stability.
The influence of activation and relaxation time on the synthesis of cordierite ceramics
Authors: Djordjevic Natasa , Pavlovic Ljubica
Published: May 2006

Due to its properties, cordierite, 2MgO.2Al2O3 .5SiO2, is nowadays an attractive ceramic material for various applications. Mechanochemical activation of the initial components was used in order to decrease the sintering temperature. Changes in the specific surface area of the activated components were determined by the BET method. The TG and DTA methods were used to monitor the temperature induced changes in the analyzed three-component system. The influence of the relaxation time on the activated components was analyzed by FTIR spectroscopy of both the initial components and the activated mixture after 24 h and 24 months relaxation periods. .
On Sylow subgroups of Sn
Authors: Bakic Rados
Published: May 2006

We give a new approach to description of p-Sylow subgroup normalizes in the groups Sn (symmetric group on n letters).
On some Akivis-Goldberg type metrics
Authors: Deszcz Ryszard
Published: May 2006

We investigate Akivis?Goldberg type metrics satisfying some additional assumptions.
A function defined on an even-dimensional real submanifold of a Hermitian manifold
Authors: Okumura Masafumi
Published: May 2006

On an even-dimensional real sub manifold of a Hermitian manifold, making use of the fundamental 2-form of the ambient manifold, we define a function. In this paper, we investigate the function in detail in some special sub manifold.
Monotone images of W-sets and hereditarily weakly confluent images of continua
Authors: Hatch Jonathan , Stanojevic Caslav
Published: May 2006

A proper subcontinuum H of a continuum X is said to be a W-set provided for each continuous surjective function f from a continuum Y onto X, there exists a subcontinuum C of Y that maps entirely onto H. Hereditarily weakly confluent (HWC) mappings are those with the property that each restriction to a subcontinuum of the domain is weakly confluent. In this paper, we show that the monotone image of a W-set is a W-set and that there exists a continuum which is not in class W but which is the HWC image of a class W continuum.