360 research outputs found

    An Experimental Derivation of Partial Structure Functions of Amorphous Pd_<80>Si_<20> Alloy Using Combination of X-ray, Electron and Neutron Diffraction Experiments

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    Three partial interference functions corresponding to Pd-Pd, Pd-Si and Si-Si correlations have been separated using the combination of three total interference functions observed by neutron, X-ray and electron diffraction experiments respectively. The number-concentration correlation functions were calculated from the partial Pd-Pd, Pd-Si and Si-Si correlation functions

    A Geometrical Relaxation Model on Structure Change and Kinetics during Low-Temperature Annealing of Amorphous Metals

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    The atomic scale structure relaxation in melt-quenched amorphous metals has been simulated in a computer using a geometrical relaxation model of the dense random packing of hard spheres. The atomic arrangement and kinetics during the geometrical relaxation has been compared with the experimental behaviors on the low-temperature annealing of amorphous alloys

    A Study of Fermi Surfaces of the α-Phase Cu-Ge and Cu-Si Alloys by Positron Annihilation(Physics)

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    Angular correlation measurements on the fcc solid solutions of Cu-Ge and Cu-Si alloys have been carried out on single crystals with four crystallographic orientations by a crossed-slit geometry. The results on both the alloys are nearly the same. The -neck radius and the -radius of the Fermi surfaces increase almost linearly with increasing electron concentration in accord with previous results on Cu-Al and Cu-Zn alloys. The Fermi surface does not touch the square faces of the Brillouin zone at the solubility limit. The results agree fairly well with a calculation based on the sinking-conduction band model

    The Fermi Surfaces of Cu-Pd Alloys Studied by Positron Annihilation(Physics)

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    The Fermi surfaces of Cu-Pd alloys below 63% Pd are studied by means of the angular correlation of positron annihilation with crossed-and long-slit geometries. The (001)- and (110)-radii decrease with increasing palladium content up to 30% in agreement with a calculation based on the rigid band model. The (111) neck radius also decreases with increasing composition, and it is suggested that the Fermi surface detaches from the hexagonal face of the Brillouin zone around 20% Pd, but remains to bulge in this direction at higher compositions. No detectable change is found in the correlation curves of the ordered and disordered states at 15 and 19% Pd. The origin of stabilization of the long period ordered structure near Cu_3Pd is discussed in the light of the present results

    The role of subunit epsilon in the catalysis and regulation of FOF1-ATP synthase

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    AbstractThe regulation of ATP synthase activity is complex and involves several distinct mechanisms. In bacteria and chloroplasts, subunit epsilon plays an important role in this regulation, (i) affecting the efficiency of coupling, (ii) influencing the catalytic pathway, and (iii) selectively inhibiting ATP hydrolysis activity. Several experimental studies indicate that the regulation is achieved through large conformational transitions of the α-helical C-terminal domain of subunit epsilon that occur in response to membrane energization, change in ATP/ADP ratio or addition of inhibitors. This review summarizes the experimental data obtained on different organisms that clarify some basic features as well as some molecular details of this regulatory mechanism. Multiple functions of subunit epsilon, its role in the difference between the catalytic pathways of ATP synthesis and hydrolysis and its influence on the inhibition of ATP hydrolysis by ADP are also discussed

    RUNNING ECONOMY AND GASTROCNEMIUS MUSCLE LENGTH DURING RUNNING FOR KENYAN AND JAPANESE ELITE DISTANCE RUNNERS

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    The purpose of this study was to compare running economy and gastrocnemius muscle length during running for Kenyan and Japanese elite distance runners. Running economy was measured on the treadmill at 340 m/min while running motion was captured on the inside straight track at their racing speed. Gastrocnemius muscle length was estimated by the equation of Grieve et al. (1978) during the support phase at race speed running on the track. Kenyan runners showed higher running economy and smaller shortening length change of gastrocnemius during support phase than Japanese. These results suggest that shortening gastrocnemius during support phase of the running relates to running economy

    Shift Work and Diabetes Mellitus among Male Workers in Japan:Does the Intensity of Shift Work Matter?

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    The purpose of this study was to examine the association between shift work and diabetes mellitus by separating shift workers according to the intensity of their shift work (seasonal shift work and continuous shift work). Between May and October 2009, we collected data from annual health checkups and questionnaires at a manufacturing company in Shizuoka, Japan. Questionnaires were returned by 1,601 workers (response rate:96.2%, men/women=1,314/287). Diabetes mellitus was defined as hemoglobin A1c≥6.5% and fasting blood sugar≥126mg/dl. After exclusions, which included all the women and clerical workers because they did not work in shifts, we analyzed 475 skilled male workers. After adjusting for age, smoking status, frequency of alcohol consumption, and cohabitation status, odds ratios for diabetes mellitus were 0.98 (95% confidence interval [CI]:0.28-4.81) and 2.10 (95% CI:0.77-5.71) among seasonal shift workers and continuous shift workers, respectively, compared with non-shift workers. In an age-stratified analysis (<45 years vs.≥45 years), the association between continuous shift work and diabetes mellitus was more pronounced among older participants. Compared with non-shift workers, the risk of diabetes mellitus was increased among continuous shift workers, whereas its effect is limited among seasonal shift workers

    Effects of Heparin and Enoxaparin on APP Processing and Aβ Production in Primary Cortical Neurons from Tg2576 Mice

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    BACKGROUND Alzheimer's disease (AD) is caused by accumulation of Aβ, which is produced through sequential cleavage of β-amyloid precursor protein (APP) by the β-site APP cleaving enzyme (BACE1) and γ-secretase. Enoxaparin, a low molecular weight form of the glycosaminoglycan (GAG) heparin, has been reported to lower Aβ plaque deposition and improve cognitive function in AD transgenic mice. METHODOLOGY/PRINCIPAL FINDINGS We examined whether heparin and enoxaparin influence APP processing and inhibit Aβ production in primary cortical cell cultures. Heparin and enoxaparin were incubated with primary cortical cells derived from Tg2576 mice, and the level of APP and proteolytic products of APP (sAPPα, C99, C83 and Aβ) was measured by western blotting. Treatment of the cells with heparin or enoxaparin had no significant effect on the level of total APP. However, both GAGs decreased the level of C99 and C83, and inhibited sAPPα and Aβ secretion. Heparin also decreased the level of β-secretase (BACE1) and α-secretase (ADAM10). In contrast, heparin had no effect on the level of ADAM17. CONCLUSIONS/SIGNIFICANCE The data indicate that heparin and enoxaparin decrease APP processing via both α- and β-secretase pathways. The possibility that GAGs may be beneficial for the treatment of AD needs further study.This work was funded by a project grant (490031) from the National Health and Medical Research Council of Australia (http://www.nhmrc.gov.au). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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