120 research outputs found

    Fe-Mg heteorogeneity in the low-Ca pyroxenes during metamorphism of the ordinary chondrites

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    Pyroxenes in nine ordinary chondrites, ALH-764 (LL3), ALH-77214 (L3.4), ALH-77015 (L3.5), Yamato-74191 (L3.6), Hedjaz (L3.7), ALH-77304 (LL3.8), ALH-78084 (H3.9), Yamato-75097 (L4) and ALH-77230 (L4), were examined by an optical microscope, a scanning electron microscope with a back-scattered electron image technique, and an X-ray microprobe analyzer. Characteristic textures due to alternating lamellae of Fe-rich and Fe-poor compositions have been found in the low-Ca pyroxenes in the chondrites irrespective of their chemical groups, H, L and LL. As far as the author knows, this is the first observation of such lamellae textures in the pyroxenes. These textures are common and remarkable in the higher subtypes of type 3 chondrites (L3.6,L3.7,LL3.8 and H3.9), while they are rare in lower subtypes (<3.5) and type 4 chondrites. These textures are considered to have been formed in the Fe-Mg homogenization process of the ordinary chondrites during metamorphism

    An electron microscopic study of gas condensates in the system Mg-Si-O-H

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    Condensates of MgSiO_3 and SiO_2 from a gas formed by evaporation of enstatite at an H_2 pressure of 4.4×10^ bar and a temperature of 1525℃ by B. O. MYSEN and I. KUSHIRO (Am. Mineral. (in press), 1988) and I. KUSHIRO and B. O. MYSEN (Advances in Physical Geochemistry, New York, Springer (in press), 1988) were investigated with an analytical transmission electron microscope (ATEM), a scanning electron microscope (SEM) and an electron probe microanalyzer (EPMA). With decreasing temperature at an approximately constant total pressure the Mg/(Mg+Si) atomic ratio of the condensate (mixture of MgSiO_3 and SiO_2 polymorphs) decreases first, then increases, and finally reaches a constant value. This compositional change of the condensate is inconsistent with the equilibrium condensation model. The TEM studies suggest that metastable condensation of coesite and probably of protoenstatite and cristobalite took place. Coesite probably condensed by heterogeneous nucleation on protoenstatite. Fibrous quartz was also formed by heterogeneous nucleation on molybdenum fibers which condensed from a molybdenum vapor by a partial evaporation of a Knudsen cell used in the experiment. Heterogeneous nucleation might have played an important role in condensation process in the solar nebula. The texture of the experimental clinopyroxene condensate is different from that in interplanetary dust particles (J. P. BRADLEY et al., Nature, 301,473,1983)

    Hydrogen bonds of DsrD protein revealed by neutron crystallography

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    Hydrogen bonds of DNA-binding protein DsrD have been determined by neutron diffraction. In terms of proton donors and acceptors, DsrD protein shows striking differences from other proteins

    トクシマ ダイガク ニオケル ケイエイ センス オ ユウスル π ガタ ギジュツシャ ノ イクセイ オ メザシタ チョウキ インターンシップ ノ トリクミ

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    徳島大学大学院先端技術科学教育部では,専門技術と経営に関する素養を持って工学的解決策を 提案できる課題解決型技術者の育成を目的とした教育プロジェクト「経営センスを有するπ型技術者の 協働育成プログラム」を実施している.このプログラムによって派遣した学生8 名は,専門技術だけで なく,“仕事の効率化”と“コミュニケーション能力”の重要性を認識でき,派遣先企業から高い評価 を得た.その一方で,課題としては,学生と企業のマッチング,企業と指導教員と学生との連携をサポ ートするコーディネータの活用,長期インターンシップ事前事後の評価基準の作成が挙げられた.Graduate School for Advanced Science and Technology, the University of Tokushima conducts "Cooperative education program of π-type engineer with business sense". This programs aim at fostered business solution professional engineer. The program sends eight students. They learn that "business efficiency" and "communication skills" from company. On the one hand, as the task is, graduate student and company matching, coordinator supported company manager and graduate student, assessment standard of pre-post-project survey

    Beneficial Effect of Brewers' Yeast Extract on Daily Activity in a Murine Model of Chronic Fatigue Syndrome

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    The aim of this study was to assess the effect of Brewers' yeast extract (BYE) on daily activity in a mouse model of chronic fatigue syndrome (CFS). CFS was induced by repeated injection of Brucella abortus (BA) antigen every 2 weeks. BYE was orally administered to mice in a dose of 2 g per kg per day for 2 weeks before injecting BA and for 4 weeks thereafter. We evaluated daily running activity in mice receiving BYE as compared with that in untreated mice. Weekly variation of body weight (BW) and survival in both groups was monitored during the observation period. Spleen weight (SW), SW/BW ratio, percent splenic follicular area and expression levels of interferon-γ (IFN-γ) and interleukin-10 (IL-10) mRNA in spleen were determined in both groups at the time of sacrifice. The daily activity during 2 weeks after the second BA injection was significantly higher in the treated group than in the control. There was no difference in BW between both groups through the experimental course. Two mice in the control died 2 and 7 days after the second injection, whereas no mice in the treated group died. Significantly decreased SW and SW/BW ratio were observed in the treated mice together with elevation of splenic follicular area. There were suppressed IFN-γ and IL-10 mRNA levels in spleens from the treated mice. Our results suggest that BYE might have a protective effect on the marked reduction in activity following repeated BA injection via normalization of host immune responses

    Epidemiology of potentially inappropriate medication use in elderly patients in Japanese acute care hospitals.

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    [Purpose]The elderly receive many medications which may have adverse effects. Little evidence is available about the epidemiology of potentially inappropriate medications being prescribed to the elderly in Japan as defined by the Beers criteria, or whether or not these medications result in harm when used in this population. [Methods]We conducted a prospective cohort study of patients aged ≥65 years who were admitted to three acute care hospitals in Japan. Trained research nurses followed up patients from randomly selected wards and collected data about their medications and all potential adverse drug events (ADEs). Two independent reviewers evaluated all the data. The use of potentially inappropriate medications and their effects on patients were identified using the updated Beers criteria. [Results]A total of 2155 elderly patients were eligible; 56.1% received at least one drug listed in the Beers criteria (BL drug). The rates of BL drug prescriptions were 103.8 per 100 admissions and 53.7 per 1000 patient-days, and the incidence rate of ADEs related to BL drugs was 1.7 per 100 BL drug prescriptions. Among patients aged ≥65 years, relatively younger patients (p = 0.0002) and those with less complications (p = 0.04) were likely to be prescribed BL drugs. [Conclusions]Although BL drugs were frequently prescribed to elderly Japanese inpatients, the incidence of related ADEs appeared infrequent. These data suggest that re-evaluation of the appropriateness of the Beers criteria is needed before they are used in Japan and other nations to assess quality or for decision support

    Mao-to Prolongs the Survival of and Reduces TNF-α Expression in Mice with Viral Myocarditis

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    Goal of this study was to evaluate effects of Mao-to on development of myocarditis induced by encephalomyocarditis (EMC) virus in mice. Mice were randomly divided into five groups. Group N included uninfected controls (n = 18), while group A, B and C underwent intraperitoneal injection of EMC virus. Group A was administered oral saline from day 0 to day 4. Group B was administered oral Mao-to (500 mg−1 kg−1 day−1) from day 0 to day 4. Group C was administered Mao-to from day 2 to day 6. Group D was administered Mao-to from day 5 to day 10. Treated mice were followed for survival rates during 2 weeks after infection. Body weight (BW) and organ weights including heart (HW), lungs, thymus and spleen were examined on days 4, 6 and 14. Survival rate of group C (36.4%) was significantly improved compared with group A, B or D (0% of each, P < 0.05). HW and HW/BW ratio in group C was significantly (P < 0.05) lower than those in group A, B or D. Viral titers of hearts were significantly different among groups A, B and C. Cardiac expression in tumor necrosis factor-α (TNF-α) was significantly reduced in group C in comparison with group A, B or D on day 6 by immunohistochemical study. Administration of Mao-to starting on day 2 improves mortality resulting from viral myocarditis in mice with reduced expression of cardiac TNF-α. These findings suggest that timing of Mao-to is crucial for preventing cardiac damage in mice with viral myocarditis
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