3,687 research outputs found

    Analysis on Safety of Removing the Closure Segment in a Prestressed Concrete Cable-stayed Bridge

    Get PDF
    AbstractAiming at failure of closure segment in a prestressed concrete cable-stayed bridge, a strengthening technology, namely replacing the closure segment, was firstly put forward. But removing the old closure segment was a process of release of internal force and had great risk. So the structural safety possibly induced by removing must be analyzed and confirmed. Based on FEM and summary of engineering experience, the construction stages for removing the old closure segment were simulated, and then some analysis relevant to safety, including thermal effect, dynamic characteristics and global stability of the whole bridge structure, were systematically presented. According to these analysis results, corresponding prevention and control measures were provided to ensure construction safety. Studies showed that, variation range of its structural state between before and after removing is not obvious, and its dynamic characteristics changed little after removing. In addition, structural instability could not be induced by removing, but for the sake of improving construction safety reliability, necessary safety prevention and control measures were indispensable. Analysis on safety of removing the old closure segment constituted the important part of the strengthening technology of replacing the closure segment, and became the theoretical basis of removing partial structural members for existing bridges

    Introduction on atomic layer deposition for high-k dielectric & high mobility oxide semiconductor thin film transistors

    Get PDF
    Amorphous oxide semiconductors have been widely studied for the potential use in flat panel displays such as active matrix liquid crystal display (LCD) and Organic light emitting diodes (OLEDs). Since reporting amorphous InGaZnO semiconductor thin film transistor (TFT) in 2003 & 2004, many multi-component oxide semiconductors have been intensively investigated and developed by reactive sputtering method. Very recently, the sputtered InGaZnO TFTs are already adopted in mass-production to fabricate AMOLED TVs. However, there remain several problems such as high mobility & stability issues. Also, virtual and argument reality (VR, AR) applications are rapidly emerging in display markets but the main issues are high resolution and low-voltage driving technologies. Please click Additional Files below to see the full abstract

    Effects of photoperiod on body mass, thermogenesis and body composition in Eothenomys miletus during cold exposure

    Get PDF
    Many small mammals respond to seasonal changes in photoperiod by altering body mass and adiposity. These animals may provide valuable models for understanding the regulation of energy balance. In present study, we examined the effect on body mass, rest metabolic rate, food intake and body composition in cold-acclimated (5 °C) in Eothenomys miletus by transferring them from a short (SD, 8h :16h L: D) to long day photoperiod (LD, 16h: 8h L:D). During the first 4 weeks of exposure to SD, E. miletus decreased body mass. After the next 4 weeks of exposure to LD, which the average difference between body masses of LD and SD voles was 4.76 g. This 14.74% increase in body mass reflected significant increases in absolute amounts of body components, including wet carcass mass, dry carcass mass and body fat mass. After correcting body composition and organ morphology data for the differences in body mass, only livers, kidney, and small intestine were enlarged due to photoperiod treatment during cold exposure. E. miletus increased RMR and energy intake exposure to LD, but maintained a stable level to SD after 28 days. Serum leptin levels were positively correlated with body mass, body fat mass, RMR as well as energy intake. All of the results indicated that E. miletus may provide an attractive novel animal model for investigation of the regulation of body mass and energy balance at organism levels. Leptin is potentially involved in the photoperiod induced body mass regulation and thermogenesis in E. miletus during cold exposure

    Effect of Acorus tatarinowii extract on hyperprolactinemia in rats

    Get PDF
    Purpose: To determine the mechanism underlying the anti-hyperprolactinemia effect of Acorus tatarinowii extract (ATE) in rats. Methods: Rats were divided into six groups (n =10 each group), viz, healthy control, untreated hyperprolactinemic rats, hyperprolactinemic rats treated with bromocriptine (0.6 mg/kg), and hyperprolactinemic rats treated with ATE (3.2, 6.4, or 12.8 g/kg). After 30 days, the hypothalamic protein levels of dopamine D2 receptor, protein kinase A (PKA), and cyclic adenosine monophosphate (cAMP) were determined. Results: Dopamine D2 receptor levels were lower in untreated hyperprolactinemic rats than in healthy control (p < 0.01), but this decrease was attenuated by ATE (p < 0.05). Elevated PKA levels in untreated hyperprolactinemic rats (0.78 ± 0.03µg/mL, p < 0.01) were decreased by ATE (3.2 g/kg, 0.51 ± 0.02 µg/mL, p < 0.05; 6.4 g/kg, 0.39 ± 0.03 µg/mL, p < 0.01; 12.8 g/kg, 0.24 ± 0.04 µg/mL, p < 0.01). Similarly, elevated cAMP levels in hyperprolactinemic rats (3.1 ± 0.3 ng/mL) were lowered by ATE (3.2 g/kg, 2.2 ± 0.4 ng/mL, p < 0.05; 6.4 g/kg, 1.8 ± 0.3 ng/mL, p < 0.01; 12.8 g/kg, 1.4 ± 0.3 ng/mL, p < 0.01). Conclusion: ATE anti-hyperprolactinemia activity is mediated by dopamine D2 receptor signaling via cAMP/PKA pathway

    Ethanol Extract of the Flower Chrysanthemum morifolium Augments Pentobarbital-Induced Sleep Behaviors: Involvement of Cl− Channel Activation

    Get PDF
    Dried Chrysanthemum morifolium flowers have traditionally been used in Korea for the treatment of insomnia. This study was performed to investigate whether the ethanol extract of Chrysanthemum morifolium flowers (EFC) enhances pentobarbital-induced sleep behaviors. EFC prolonged sleep time induced by pentobarbital similar to muscimol, a GABAA receptors agonist. EFC also increased sleep rate and sleep time when administrated with pentobarbital at a subhypnotic dosage. Both EFC and pentobarbital increased chloride (Cl−) influx in primary cultured cerebellar granule cells. EFC increased glutamic acid decarboxylase (GAD) expression levels, but had no effect on the expression of α1-, β2-, and γ2-subunits of the GABAA receptor in the hippocampus of a mouse brain. This is in contrast to treatment with pentobarbital, which showed decreased α1-subunit expression and no change in GAD expression. In conclusion, EFC augments pentobarbital-induced sleep behaviors; these effects may result from Cl− channel activation

    Prediction of large esophageal varices in cirrhotic patients using classification and regression tree analysis

    Get PDF
    OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8%. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84% for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2% for high-risk group and 15.2% for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patient
    corecore