157 research outputs found

    Influence of Tea Catechins on Lipid Metabolism

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    Tea catechins reduce serum cholesterol concentration and suppress postprandial hypertriacylglycerolemia in experimental animals and humans. These effects are mainly ascribed to gallate esters of catechins, (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG). During heat treatment for pasteurization, tea catechins are epimerized to so-called heat-treated tea catechins such as (-)-catechin gallate (CG) and (-)-gallocatechin gallate (GCG). We showed that both tea catechins and heat-treated tea catechins with galloyl moiety lower intestinal absorption of cholesterol by inhibiting micellar solubility of cholesterol. Since they inhibited pancreatic lipase in vitro and slowed down lymphatic absorption of triacylglycerol, we think that delayed intestinal absorption of triacylglycerol in the feeding of the catechin preparations causes suppression of postprandial hyper-triacylglycerolemia. It has been reported that tea catechins and heat-treated tea catechins with galloyl moiety suppress deposition of visceral fat in experimental animals and humans. Some studies suggested that stimulation of hepatic β-oxidation might be a cause of reduced deposition of visceral fat. However, our study did not show any acceleration of β-oxidation in rat liver. Although there are some controversial observations, results obtained suggest a possibility that tea catechins and heat-treated tea catechins with galloyl moiety improve lipid metabolism and contribute to prevention of life-style related diseases

    Increased Sensitivity of Atomic Absorption Analysis

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    In order to increase the sensitivity in atomic absorption spectrometry, many improvements, for example, those of light source, detector, flame and atomizer, were investigated. In addition to these improvements, it is asserted that the increased sensitivity of this kind of spectrometry by the addition of or the extraction with an organic solvent is one of the most interesting ideas from the point of analytical chemistry

    Sinistral En Echelon Folding of the Sambagawa Schists and Its Tectonic Implication

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    The folds of the Sambagawa schists, which were produced during the last phase (Hijikawa—Oboke phase = Dh phase) of their folding history, are developed as a series of sinistral en echelon upright folds with half wavelength of less than 20 Km (Hara et al.,1977,1992). The Dh phase folds in Shikoku are accompanied with two culminations, Oboke culmination and Nakashichiban culmination, placed near the MTL. Their movement picture during the formation process of such the Dh phase folds has been analyzed on the basis of orientation pattern of parasitic folds and quartz microtextures. It has been clarified that the Dh phase folds were produced by left—lateral shear under N —S compression, being accompanied by the southward tectonic emplacement of two rigid bodies which gave rise to the Oboke and Nakshichiban culminations. These bodies can be assumed to be granitic and/or high—temperature metamorphic rocks tectonically derived from the Kurosegawa—Koryoke continent, as judged from the seismic refraction data in the Oboke district after Ichikawa (1968)

    A Study of Atomic Absorption Spectrometry : Determination of Magnesium and Calcium in Slag and Cast Iron

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    Atomic absorption-spectrometric determinations of magnesium and of calcium were carried out and the method was applied to the determination of magnesium and calcium in slag and to the determination of magnesium in cast iron. The absorbance for magnesium was measured at 2852A by using 30 mA of current of hollow cathode lamp, 1.1 kg/cm^2 of air pressure and 0.48 kg/cm^2 of acetylene gas pressure. That for calcium was measured at 4227A by using 50 mA of current of hollow cathode lamp, 1.1 kg/cm^2 of air pressure and 0.5 kg/cm^2 of acetylene gas pressure. Effects of diverse ions and acid concentrations were also examined. Aluminium, silicon and several other ions interfered with the atomic absorption of magnesium and calcium in flame, but those interferences were all eliminated by 1.5 mg/ml of strontium in the sample solution. These fundamental results were applied to the determination of magnesium and calcium in slag. Magnesium in cast iron was also determined by a standard addition method without any preliminary separation. The results were very accurate and highly reproducible

    Statins Activate Human PPARα Promoter and Increase PPARα mRNA Expression and Activation in HepG2 Cells

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    Statins increase peroxisome proliferator-activated receptor α (PPARα) mRNA expression, but the mechanism of this increased PPARα production remains elusive. To examine the regulation of PPARα production, we examined the effect of 7 statins (atorvastatin, cerivastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin) on human PPARα promoter activity, mRNA expression, nuclear protein levels, and transcriptional activity. The main results are as follows. (1) Majority of statins enhanced PPARα promoter activity in a dose-dependent manner in HepG2 cells transfected with the human PPARα promoter. This enhancement may be mediated by statin-induced HNF-4α. (2) PPARα mRNA expression was increased by statin treatment. (3) The PPARα levels in nuclear fractions were increased by statin treatment. (4) Simvastatin, pravastatin, and cerivastatin markedly enhanced transcriptional activity in 293T cells cotransfected with acyl-coenzyme A oxidase promoter and PPARα/RXRα expression vectors. In summary, these data demonstrate that PPARα production and activation are upregulated through the PPARα promoter activity by statin treatment

    Application of Level-Set Type Topology Optimization Analysis for Cavity Shape Estimation Problem in Structures Based On Non-Destructive Hammering Test

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    In this study, we present application of the level-set type topology optimization analysis for the cavity shape estimation problem in structures based on the non-destructive hammering test. The cavity shape is identified so as to minimize a performance function. The performance function is defined as the square sum of the residual between computed and the observed displacements on structure surface. In this study, accuracy of identified cavity shape is investigated by changing numerical parameters in the topology optimization

    Structured triacylglycerol containing behenic and oleic acids suppresses triacylglycerol absorption and prevents obesity in rats

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    <p>Abstract</p> <p>Background</p> <p>Dietary 1(3)-behenoyl-2,3(1)-dioleoyl-<it>rac</it>-glycerol (BOO) has been reported to inhibit pancreatic lipase activity <it>in vitro </it>and suppress postprandial hypertriacylglycerolemia in humans. In the present study, the anti-obesity activities of BOO and its inhibitory effects on lymphatic triacylglycerol (TAG) absorption were investigated in rats.</p> <p>Methods</p> <p>In Experiment 1, rats were fed either BOO or soybean oil (SO) diet for 6 weeks. In the BOO diet, 20% of SO was replaced with an experimental oil rich in BOO. In Experiments 2 and 3, rats cannulated in the thoracic duct were administered an emulsions containing trioleoylglycerol (OOO) or an oil mixture (OOO:BOO, 9:1). Tri[1-<sup>14</sup>C]oleoylglycerol (<sup>14</sup>C-OOO) was added to the emulsions administered in Experiment 3.</p> <p>Results</p> <p>No observable differences were detected in food intake or body weight gain between the BOO and SO groups in Experiment 1. Plasma and liver TAG concentrations and visceral fat weights were significantly lower in the BOO group than in the SO group. The apparent absorption rate of fat was significantly lower in the BOO group than in the SO group. In Experiment 2, the lymphatic recovery of oleic and behenic acids was significantly lower at 5 and 6 h after BOO administration than after OOO administration. In Experiment 3, the lymphatic recovery of <sup>14</sup>C-OOO was significantly lower at 5 and 6 h after BOO administration than after OOO administration.</p> <p>Conclusions</p> <p>These results suggest that BOO prevents deposition of visceral fat and hepatic TAG by lowering and delaying intestinal absorption of TAG.</p

    Photoelastic Stress Analysis Error Quantification in Vasculature Models for Robot Feedback Control

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    Abstract-Real-time and accurate stress calculation in walls of vasculature is desired to provide catheter insertion robots of feedback control without changing the catheter stiffness and lumen. This feedback source has also applications in endovascular surgery simulation for human skills and medical tools evaluation. For that purpose we consider photoelastic effect, as birefringence produced by light retardation relates with the stress inside the photoelastic materials. In this research a polariscope was designed for urethane elastomer vasculature models, the photoelastic coefficient of urethane elastomer was measured, and the camera system was calibrated to quantify and reduce error of the measurement system. An average error of 3.6% was found for the pressure range of 70-189 mmHg inside the model of urethane elastomer, this enables to calculate accurately stress in vasculature models during Human Blood Pressure Simulation (HBPS). That way we will be able to compare in a closed loop stress produced by HBPS and by the catheter motion when manipulated by a robot. I. INTRODUCTION RAINING with simulators reduces risks of injury and costs during practice for minimally invasive surgery C. Tercero is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: [email protected]). S. Ikeda is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: ikeda @robo.mein.nagoya-u.ac.jp). In previous studies photoelastic effect was used with a catheter insertion robot to evaluate catheters In this research we will present a calibration method for the transmittance equation to measure the optical path length, a polariscope designed for our simulation purpose, the deduction of the photoelastic coefficient of urethane elastomer, and the normalization parameters calibration to calculate the principal component of stress in the vasculature model with an inner pressure range of 40-189mmHg. It is desirable to measure stress with an error below 5% for the HBPS range, to use it as reference for control loop illustrated in figure 2. Photoelastic Stress Analysis Error Quantification i
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