5,181 research outputs found

    Change-Point Estimation of Nonstationary I(d) Processes

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    We examine the least-squares estimator of change point for nonstationary I(d) data with 0.5least-squares estimator, change point, nonstationary I(d) process, spurious change

    Performance Testing of Micro Loop Heat Pipes

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    [[abstract]]A 60 mm×33 mm×0.8 mm micro loop heat pipe (MLHP), consisting of an evaporator, vapor line, condenser and two liquid lines, was fabricated and characterized. The wicking structure consists of parallel V-grooves with a hydraulic diameter of 47 μm, 67 μm and 83 μm, and is formed by bulk silicon etching. The MLHP was realized by bonding a glass wafer onto a silicon substrate, so as to result in a transparent cover for two-phase flow visualization. Water and methanol were used as the working fluids. The test results showed that water demonstrates a wider heat load performance range (3.3W~12.96W) than methanol (1.2W~5.85W) for the MLHP with an evaporator area of 1 cm^2 and condenser temperature of 17℃. The best thermal resistance of the MLHP was 0.106℃/W, 64 times higher than that without fluid filling. The smaller diameter grooves caused the higher liquid capillarity and enhanced transfer capacity. It was observed that the presence of non-condensable gas negatively affected the reliability of the MLHP and significantly reduced the performance.[[notice]]補正完畢[[incitationindex]]A&HC

    Anti-inflammatory and anti-coagulatory activities of caffeic acid and ellagic acid in cardiac tissue of diabetic mice

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    <p>Abstract</p> <p>Background</p> <p>Caffeic acid (CA) and ellagic acid (EA) are phenolic acids naturally occurring in many plant foods. Cardiac protective effects of these compounds against dyslipidemia, hypercoagulability, oxidative stress and inflammation in diabetic mice were examined.</p> <p>Methods</p> <p>Diabetic mice were divided into three groups (15 mice per group): diabetic mice with normal diet, 2% CA treatment, or 2% EA treatment. One group of non-diabetic mice with normal diet was used for comparison. After 12 weeks supplement, mice were sacrificed, and the variation of biomarkers for hypercoagulability, oxidative stress and inflammation in cardiac tissue of diabetic mice were measured.</p> <p>Results</p> <p>The intake of CA or EA significantly increased cardiac content of these compounds, alleviated body weight loss, elevated plasma insulin and decreased plasma glucose levels in diabetic mice (<it>p </it>< 0.05). These treatments also significantly enhanced plasma antithrombin-III and protein C activities (<it>p </it>< 0.05); and decreased triglyceride content in cardiac tissue and plasma (<it>p </it>< 0.05), in which the hypolipidemic effects of EA were significantly greater than that of CA (<it>p </it>< 0.05). CA or EA significantly lowered cardiac levels of malondialdehyde, reactive oxygen species, interleukin (IL)-beta, IL-6, tumor necrosis factor (TNF)-alpha and monocyte chemoattractant protein (MCP)-1 (<it>p </it>< 0.05); and retained cardiac activity of glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (<it>p </it>< 0.05). These compounds also significantly up-regulated cardiac mRNA expression of GPX1, SOD and catalase; and down-regulated IL-1beta, IL-6, TNF-alpha and MCP-1 mRNA expression in diabetic mice (<it>p </it>< 0.05).</p> <p>Conclusion</p> <p>These results support that CA and EA could provide triglyceride-lowering, anti-coagulatory, anti-oxidative, and anti-inflammatory protection in cardiac tissue of diabetic mice. Thus, the supplement of these agents might be helpful for the prevention or attenuation of diabetic cardiomyopathy.</p
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