90 research outputs found

    Asymmetrical membrane fluidity of bovine adrenal chromaffin cells and granules and effect of trichosporin-B-VIa

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    AbstractWe examined membrane fluidity of bovine adrenal chromaffin cells and chromaffin granules using cationic trimethylammonium derivative of diphenylhexatriene (TMA-DPH) as a fluorescence probe. After adding TMA-DPH to the suspension of chromaffin cells and that of granules, it first bound to the outer layer of the plasma membrane of the cells and that of the granule membrane, then gradually penetrated the inner layer of each membrane and distributed to both leaflets of the respective membranes. Accompanying increases in the ratio of incorporated probe on the cytoplasmic side of the chromaffin cell membrane, its fluorescence anisotropy gradually decreased. However, in chromaffin granules, the fluorescence anisotropy gradually increased with increases in the ratio of incorporated probe. These findings suggest that the inner layer of the plasma membrane and outer layer of the granular membrane are more fluid than the corresponding side of each membrane, which is suitable for the fusion between both membranes. We also examined the effect of trichosporin-B-VIa, a fungal ion channel forming α-aminoisobutyric acid-containing peptide, on the fluidity of chromaffin cells using TMA-DPH. The peptide decreased the fluorescence anisotropy and increased the fluorescence intensity in the concentration range that induced Ca2+ dependent catecholamine secretion, suggesting that a change in lipid dynamics of the lipid bilayer of the plasma membrane was induced by this peptide

    Validity of Dietary Surveys in Physically Active Japanese Male Students

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    Under or overestimating dietary intake is considered a serious problem in dietary surveys. We compared estimated energy intake (EI) with measured total energy expenditure (TEE) in 22 physically active Japanese male students (age: 20.6±1.2 years: active group) and 37 physically non-active male students (age: 19.3±1.4 years: control group). EI was estimated by a food frequency questionnaire (FFQg). TEE was calculated by using the time study method with a measured basal metabolic rate. The accuracy of EI (EI/TEE) was 0.57 in the active group and 0.74 in the control group; showing a significant difference between the two groups (p<0.01). EI/TEE was negatively associated (r=-0.395, p<0.05) with BMI in the control group, but not in the active group. Intake of confectioneries, oils and fruits in the active group was significantly higher (p<0.01, p<0.05, p<0.01 respectively) than the control group. Intake of confectioneries and fruits per 1,000kcal was significantly higher (p<0.05, p<0.01 respectively) but grains were significantly lower (p<0.01) in the active group than the control group. EI/TEE was positively associated (r=0.539, p<0.05) with intake of fish per 1,000kcal in the active group. These results suggested that underestimating dietary intake might occur more often among physically active male students than physically inactive male students and it seemed to be associated with their lack of interest in food rather than psychological factors

    Quantitative study of near equilibrium in dissociative mechanism of nickel in silicon

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    The dissociative mechanism of nickel in silicon has been studied experimentally, assuming the near equilibrium represented by CiCV / Cs = Ci eq C eq / Cs eq , where subscripts i, V, and s represent interstitial nickel atoms, vacancies, and substitutional nickel atoms, respectively, superscript eq represents the thermal equilibrium, and CA is the concentration of component A. However, the assumption of the near equilibrium has not yet been verified experimentally, because it is difficult to measure CV in silicon. In the present work, the simultaneous diffusion equations of the dissociative mechanism of nickel in silicon are solved numerically by double-precision FORTRAN without assuming the near equilibrium under the condition of in-diffusion of nickel into a silicon specimen, and the establishment of the near equilibrium is verified. It is also clarified that the near equilibrium is a transitional process which continues until the thermal equilibrium is reached. After the near equilibrium is reached, the very small difference of two nearly equal terms is an important factor in solving the diffusion equations. In other words, high accuracy is necessary to solve the diffusion equations. Concerning this, it is verified that the accuracy of double-precision FORTRAN is sufficiently high to solve the diffusion equations in the present work

    Identifying dynamical systems with bifurcations from noisy partial observation

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    Dynamical systems are used to model a variety of phenomena in which the bifurcation structure is a fundamental characteristic. Here we propose a statistical machine-learning approach to derive lowdimensional models that automatically integrate information in noisy time-series data from partial observations. The method is tested using artificial data generated from two cell-cycle control system models that exhibit different bifurcations, and the learned systems are shown to robustly inherit the bifurcation structure.Comment: 16 pages, 6 figure

    Optical and Near-Infrared Photometry of Nova V2362 Cyg : Rebrightening Event and Dust Formation

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    We present optical and near-infrared (NIR) photometry of a classical nova, V2362 Cyg (= Nova Cygni 2006). V2362 Cyg experienced a peculiar rebrightening with a long duration from 100 to 240 d after the maximum of the nova. Our multicolor observation indicates an emergence of a pseudophotosphere with an effective temperature of 9000 K at the rebrightening maximum. After the rebrightening maximum, the object showed a slow fading homogeneously in all of the used bands for one week. This implies that the fading just after the rebrightening maximum ( less or equal 1 week ) was caused by a slowly shrinking pseudophotosphere. Then, the NIR flux drastically increased, while the optical flux steeply declined. The optical and NIR flux was consistent with blackbody radiation with a temperature of 1500 K during this NIR rising phase. These facts are likely to be explained by dust formation in the nova ejecta. Assuming an optically thin case, we estimate the dust mass of 10^(-8) -- 10^(-10) M_solar, which is less than those in typical dust-forming novae. These results support the senario that a second, long-lasting outflow, which caused the rebrightening, interacted with a fraction of the initial outflow and formed dust grains.Comment: 6 pages, 4 figures, 2010, PASJ, 62, 1103--1108, in pres

    The 2006 November outburst of EG Aquarii: the SU UMa nature revealed

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    We report time-resolved CCD photometry of the cataclysmic variable EG Aquarii during the 2006 November outburst During the outburst, superhumps were unambiguously detected with a mean period of 0.078828(6) days, firstly classifying the object as an SU UMa-type dwarf nova. It also turned out that the outburst contained a precursor. At the end of the precursor, immature profiles of humps were observed. By a phase analysis of these humps, we interpreted the features as superhumps. This is the second example that the superhumps were shown during a precursor. Near the maximum stage of the outburst, we discovered an abrupt shift of the superhump period by {\sim} 0.002 days. After the supermaximum, the superhump period decreased at the rate of P˙/P\dot{P}/P=8.2×105-8.2{\times}10^{-5}, which is typical for SU UMa-type dwarf novae. Although the outburst light curve was characteristic of SU UMa-type dwarf novae, long-term monitoring of the variable shows no outbursts over the past decade. We note on the basic properties of long period and inactive SU UMa-type dwarf novae.Comment: 9 pages, 7 figures, accepted for PAS

    マッショウ タンカクキュウ サイボウ オ モチイタ マッショウ ドウミャク ヘイソクショウ ニ タイスル アラタナ ケッカン シンセイ リョウホウ ノ ココロミ

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    Earlier studies have shown that bone marrow-derived mononuclear cell(BM-MNC)implantation induces therapeutic angiogenesis in patients with peripheral arterial disease(PAD). However, the invasiveness of bone marrow collection limits clinical application of BM-MNC implantation.We performed peripheral blood-derived mononuclear cell(PB-MNC)implantation in ischemic limbs of five patients with PAD. After implantation, clinical symptoms such as rest pain and numbness were relieved in four patients. Maximal walking distance markedly increased from 160 m to 915 m in one patient. Non-healing ulcers were cured after repeated cell implantation in one patient with Burger disease. There was no adverse event. These findings suggest that PB-MNC implantation is a safe and noninvasive strategy for therapeutic angiogenesis for the treatment of severe PAD

    JPN Guidelines for the management of acute pancreatitis: severity assessment of acute pancreatitis

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    This article addresses the criteria for severity assessment and the severity scoring system of the Ministry of Health and Welfare of Japan; now the Japanese Ministry of Health, Labour, and Welfare (the JPN score). It also presents data comparing the JPN score with the Acute Physiology and Chronic Health Evaluation (APACHE) II score and the Ranson score, which are the major measuring scales used in the United States and Europe. The goal of investigating these scoring systems is the achievement of earlier diagnosis and more appropriate and successful treatment of severe or moderate acute pancreatitis, which has a high mortality rate. This article makes the following recommendations in terms of assessing the severity of acute pancreatitis
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