89 research outputs found

    Exploration of new superconductors and functional materials and fabrication of superconducting tapes and wires of iron pnictides

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    This paper reviews the highlights of a 4-years-long research project supported by the Japanese Government to explore new superconducting materials and relevant functional materials. The project found several tens of new superconductors by examining ~1000 materials, each of which was chosen by Japanese team member experts with a background in solid state chemistry. This review summarizes the major achievements of the project in newly found superconducting materials, and the wire and tape fabrication of iron-based superconductors. It is a unique feature of this review to incorporate a list of ~700 unsuccessful materials examined for superconductivity in the project. In addition, described are new functional materials and functionalities discovered during the project.Comment: 141 pages, 127 Figures, 14 Tables, 535 Refrence

    PPARγ Ligand as a Promising Candidate for Colorectal Cancer Chemoprevention: A Pilot Study

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    Activating synthetic ligands for peroxisome proliferator-activated receptor gamma (PPARγ), such as pioglitazone, are commonly used to treat persons with diabetes mellitus with improvement of insulin resistance. Several reports have clearly demonstrated that PPARγ ligands could inhibit colorectal cancer cell growth and induce apoptosis. Meanwhile, aberrant crypt foci (ACF) have come to be established as a biomarker of the risk of CRC in azoxymethane-treated mice and rats. In humans, ACF can be detected using magnifying colonoscopy. Previously, CRC and adenoma were used as a target for chemopreventive agents, but it needs a long time to evaluate, however, ACF can be a surrogate marker of CRC even for a brief period. In this clinical study, we investigated the chemopreventive effect of pioglitazone on the development of human ACF as a surrogate marker of CRC. Twenty-nine patients were divided into two groups, 20 were in the endoscopically normal control group and 9 were in the pioglitazone (15 mg/day) group, and ACF and adenoma were examined before and after 1-month treatment. The number of ACF was significantly decreased (5.8 ± 1.1 to 3.3 ± 2.3) after 1 month of pioglitazone treatment, however, there was no significant change in the number of crypts/ACF or in the number and size of adenomas. Pioglitazone may have a clinical application as a cancer-preventive drug. This investigation is just a pilot study, therefore, further clinical studies are needed to show that the PPARγ ligand may be a promising candidate as a chemopreventive agent for colorectal carcinogenesis

    Durability Analysis of the REIMEI Satellite Li-ion Batteries after more than 14 Years of Operation in Space

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    The satellite REIMEI was launched in August 2005, this is one of the first satellites to use Li-ion batteries. REIMEI is a small scientific satellite designed for carrying out aurora observations using three different cameras. The main scientific mission of the satellite ended in 2013. More than 14 years have passed, and the batteries have experienced over 78,100 charge/discharge cycles. REIMEI remains in operation with a new mission dedicated to analyzing its Li-ion battery. In this work, we present a durability analysis for the REIMEI battery based on telemetry data

    Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF). ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients.</p> <p>Methods/Design</p> <p>This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation.</p> <p>Discussion</p> <p>This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with type 2 diabetes taking under treatment with metformin have been reported to be at a lower risk of cancer development than those not taking under treatment with metformin. We showed in a previous study that metformin suppressed the formation of human colorectal ACF. We therefore decided to conduct a study to determine whether metformin might suppress the formation of human colorectal polyps.</p> <p>Trial registration</p> <p>This trial has been registered in the University hospital Medical Information Network (UMIN) Clinical Trials Registry as <a href="http://www.clinicaltrials.gov/ct2/show/UMIN000006254">UMIN000006254</a></p

    Microstructure-resolved degradation simulation of lithium-ion batteries in space applications

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    In-orbit satellite REIMEI, developed by the Japan Aerospace Exploration Agency, has been relying on off-the-shelf Li-ion batteries since its launch in 2005. The performance and durability of Li-ion batteries is impacted by various degradation mechanisms, one of which is the growth of the solid-electrolyte interphase (SEI). In this article, we analyse the REIMEI battery and parameterize a full-cell model with electrochemical cycling data, computer tomography images, and capacity fading experiments using image processing and surrogate optimization. We integrate a recent model for SEI growth into a full-cell model and simulate the degradation of batteries during cycling. To validate our model, we use experimental and in-flight data of the satellite batteries. Our combination of SEI growth model and microstructure-resolved 3D simulation shows, for the first time, experimentally observed inhomogeneities in the SEI thickness throughout the negative electrode for the degraded cell

    Roxithromycin Specifically Inhibits Development of Collagen Induced Arthritis and Production of Proinflammatory Cytokines by Human T Cells and Macrophages

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    ABSTRACT. Objective. Roxithromycin (RXM) is a macrolide antibiotic that is effective in treatment of chronic lower respiratory tract diseases including diffuse panbronchiolitis and bronchial asthma. Its mechanism of action apart from its antibacterial action remains unclear. To determine the mechanism of action of RXM, we evaluated the effect of RXM on T cell functions and the inflammatory responses in mice with collagen induced arthritis (CIA). Methods. T cell proliferation, cytokine production by T cells stimulated through CD28, CD26, or PMA with or without anti-CD3 Mab, cytokine production by macrophages stimulated with lipopolysaccharide, and transendothelial migration of T cells were analyzed in the presence or absence of various concentrations of RXM. We evaluated the effect of RXM treatment in collagen induced arthritis in mice. Results. RXM did not affect the production of Th1-type and Th2-type cytokines, whereas it specifically inhibited production of proinflammatory cytokines such as tumor necrosis factor-α and interleukin 6 (IL-6) by T cells and macrophages. RXM inhibited T cell migration. We found that RXM treatment of mice with CIA reduced the severity of arthritis and serum level of IL-6, as well as leukocyte migration into the affected joints and destruction of bones and cartilage. Conclusion. Our findings strongly suggest that RXM may be useful for the therapy of rheumatoid arthritis as well as other inflammatory diseases such as Crohn&apos;s disease. (J Rheumatol 2005; 32:1765-74

    Early effect of oral administration of omeprazole with mosapride as compared with those of omeprazole alone on the intragastric pH

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    <p>Abstract</p> <p>Background</p> <p>The ideal medication for acid-related diseases should have a rapid onset of action to promote hemostasis and cause efficient resolution of symptoms. The aim of our study was to comparatively investigate the inhibitory effect on gastric acid secretion of a single oral administration of omeprazole plus mosapride with that of omeprazole alone.</p> <p>Methods</p> <p>Ten Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 6 hours after a single oral administration of omeprazole 20 mg or that of omeprazole 20 mg plus mosapride 5 mg (the omeprazole being administered one hour after the mosapride). Each administration was separated by a 7-days washout period.</p> <p>Results</p> <p>The average pH during the 6-hour period after administration of omeprazole 20 mg plus mosapride 5 mg was higher than that after administration of omeprazole 20 mg alone (median: 3.22 versus 4.21, respectively; <it>p </it>= 0.0247).</p> <p>Conclusions</p> <p>In H. pylori -negative healthy male subjects, an oral dose of omeprazole 20 mg plus mosapride 5 mg increased the intragastric pH more rapidly than omeprazole 20 mg alone.</p

    Low-Temperature Deposition of Nanocrystalline ZnO Phosphor Films from Neutral Ethanolic Zinc Acetate Solutions in the Absence of Base

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    Nanocrystalline ZnO phosphor films were prepared from an ethanolic solution of zinc acetate dihydrate on fluorine-doped tin oxide coated glass substrates through a chemical bath deposition at a low temperature of 60°C. Because the deposition was achieved without using a base such as NaOH or LiOH, the ZnO film prepared was chemically pure in terms of cation impurities. It was indicated that the deposition of ZnO 26 Another problem encountered in these methods is that they include procedures that are harmful to certain kinds of practically useful substrate materials for film depositions. Basic solutions employed in colloid For the film deposition, a portion of the above-mentioned solution was placed into a 20 mL glass bottle with a tight-fitting screw cap. Conducting glass plates coated with F-doped SnO 2 ͑FTO͒ were used as substrates. The glass substrate was immersed in the solution so that it could slant against the bottle wall and the FTO-coated side could face the bottom of the bottle. The bottle was placed in a constant temperature oven and kept at 60°C for 48 h. After the deposition, the substrates were removed from the bottle, rinsed with ethanol, and dried at room temperature. Crystal structure identification was made by X-ray diffraction ͑XRD͒ with a Rigaku model RAD-C diffractometer using Cu K␣ radiation. Morphology and particle sizes were observed by fieldemission scanning electron microscopy ͑FESEM͒ and highresolution transmission electron microscopy ͑HRTEM͒ with a Hitachi model S-4700 and a Philips model TECNAI F20 microscope, respectively. Photoluminescence ͑PL͒ spectra were measured at room temperature with a Shimadzu model RF-5700PC using a Xe lamp ͑150 W͒ as a UV light source. Results and Discussion We first examined a reaction pathway of the ZnO formation under the neutral condition in the absence of base. It is reported that alkoxyacetate complexes are formed in polyol solutions of zinc acetate dihydrate, which leads to the formation of layered hydroxide zinc acetate ͑LHZA͒, Zn 5 (OH) 8 (CH 3 COO) 2 •2H 2 O. 27 Interestingly, we have also observed the precipitation of LHZA and its derivatives, which have slightly different compositions, in the ethanolic solution during heating at 60°C.
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