57 research outputs found

    Effect of microstructures on the electron-phonon interaction in the disordered metals Pd60_{60}Ag40_{40}

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    Using the weak-localization method, we have measured the electron-phonon scattering times τep\tau_{ep} in Pd60_{60}Ag40_{40} thick films prepared by DC- and RF-sputtering deposition techniques. In both series of samples, we find an anomalous 1/τepT21/\tau_{ep} \propto T^2\ell temperature and disorder dependence, where \ell is the electron elastic mean free path. This anomalous behavior cannot be explained in terms of the current concepts for the electron-phonon interaction in impure conductors. Our result also reveals that the strength of the electron-phonon coupling is much stronger in the DC than RF sputtered films, suggesting that the electron-phonon interaction not only is sensitive to the total level of disorder but also is sensitive to the microscopic quality of the disorder.Comment: accepted for publication in Phys. Rev.

    Acute anal stretch inhibits NMDA-dependent pelvic-urethra reflex potentiation via spinal GABAergic inhibition in anesthetized rats

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    The impact of acute anal stretch on the pelvic-urethra reflex potentiation was examined in urethane-anesthetized rats by recording the external urethra sphincter electromyogram activity evoked by the pelvic afferent stimulation. Test stimulation (1 stimulation/30 s) evoked a baseline reflex activity with a single action potential that was abolished by gallamine (5 mg/kg iv). On the other hand, the repetitive stimulation (1 stimulation/1 s) induced spinal reflex potentiation (SRP) that was attenuated by intrathecal 6-cyano-7-nitroquinoxaline- 2,4-dione (a glutamatergic alpha-amino-3-hydroxy-5-methyl- 4-isoxazoleproprionat receptor antagonist, 100 mu M, 10 mu l) and D-2-amino-5-phosphonovalerate [a glutamatergic N-methyl-D-aspartate (NMDA) antagonist, 100 mu M, 10 mu l]. Acute anal stretch using a mosquito clamp with a distance of 4 mm exhibited no effect, whereas distances of 8 mm attenuated and 12 mm abolished the repetitive stimulation-induced SRP. Intrathecal NMDA (100 mu M, 10 mu l) reversed the abolition on SRP caused by anal stretch. On the other hand, pretreated bicuculline [gamma-aminobutyric acid (GABA) A receptor antagonist, 100 mu M, 10 mu l] but not hydroxysaclofen (GABA(B) receptor antagonist) counteracted the abolition on the repetitive stimulation-induced SRP caused by the anal stretch. All of the results suggested that anal stretch may be used as an adjunct to assist voiding dysfunction in patients with overactive urethra sphincter and that GABAergic neurotransmission is important in the neural mechanisms underlying external urethra sphincter activity inhibited by anal stretch

    H-Ras oncogene counteracts the growth-inhibitory effect of genistein in T24 bladder carcinoma cells

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    Among eight human bladder cancer cell lines we examined, only T24 cells were resistant to the growth inhibition effect of genistein, an isoflavone and potent anticancer drug. Since the T24 cell line was the only cell line known to overexpress oncogenic H-Ras(val12), we investigated the role of H-Ras(val 12) in mediating drug resistance. Herein, we demonstrate that the phenotype of T24 cells could be dramatically reversed and became relatively susceptible to growth inhibition by genistein if the synthesis of H- Ras(val 12) or its downstream effector c-Fos had been suppressed. The inhibition of Ras-mediated signalling with protein kinase inhibitors, such as PD58059 and U0126 which inhibited MEK and ERK, in T24 cells also rendered the identical phenotypic reversion. However, this reversion was not observed when an inhibitor was used to suppress the protein phosphorylation function of PI3 K or PKC. These results suggest that the signal mediated by H-Ras(val 12) is predominantly responsible for the resistance of the cells to the anticancer drug genistein

    Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

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    Load-carrying capacities and failure modes of scaffold-shoring systems, Part II: An analytical model and its closed-form solution

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    Critical loads and load-carrying capacities for steel scaffolds used as shoring systems were compared using computational and experimental methods in Part I of this paper. In that paper, a simple 2-D model was established for use in evaluating the structural behavior of scaffold-shoring systems. This 2-D model was derived using an incremental finite element analysis (FEA) of a typical complete scaffold-shoring system. Although the simplified model is only two-dimensional, it predicts the critical loads and failure modes of the complete system. The objective of this paper is to present a closed-form solution to the 2-D model. To simplify the analysis, a simpler model was first established to replace the 2-D model. Then, a closed-form solution for the critical loads and failure modes based on this simplified model were derived using a bifurcation (eigenvalue) approach to the elastic-buckling problem. In this closed-form equation, the critical loads are shown to be function of the number of stories, material properties, and section properties of the scaffolds. The critical loads and failure modes obtained from the analytical (closed-form) solution were compared with the results from the 2-D model. The comparisons show that the critical loads from the analytical solution (simplified model) closely match the results from the more complex model, and that the predicted failure modes are nearly identical

    Load-carrying capacities and failure modes of scaffold-shoring systems, Part I: Modeling and experiments

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    This paper proposes a simple numerical model for use in a finite analysis (FEA) of scaffold-shoring systems. The structural model consists of a single set of multiple-story scaffolds with constraints in the out-of-plane direction at every connection joint between stories. Although this model has only two dimensions (termed the 2-D model), it is derived from the analysis of a complete scaffold-shoring system and represents the structural behavior of a complete three-dimensional system. Experimental testing of scaffolds up to three stories in height conducted in the laboratory, along with an outdoor test of a five-story scaffold system, were used to validate the 2-D model. Both failure modes and critical loads were compared. In the comparison of failure modes, the computational results agree very well with the test results. However, in the comparison of critical loads, computational results were consistently somewhat greater than test results. The decreasing trends of critical loads with number of stories in both the test and simulation results were similar. After investigations to explain the differences between the computationally and experimentally determined critical loads, it was recommended that the 2-D model be used as the numerical model in subsequent analysis. In addition, the computational critical loads were calibrated and revised in accordance with the experimental critical loads, and the revised critical loads were then used as load-carrying capacities for scaffold-shoring systems for any number of stories. Finally, a simple procedure is suggested for determining load-carrying capacities of scaffold-shoring systems of heights other than those considered in this study

    A monitoring method for scaffold-frame shoring systems for elevated concrete formwork

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    This article proposes a monitoring method to prevent scaffold-frame shoring systems, used as a falsework for an elevated concrete formwork, from collapse. Basically, if a scaffold-frame shoring fails, it fails in buckling failure mode. To avoid the buckling failure, it is recommended that two parameters, axial forces and lateral displacements, be monitored in the field. The allowable axial forces and displacements for these two parameters as well as the locations of the monitoring instruments to be installed are proposed based on analysis and full-scale laboratory experiments. A data gathering real-time analysis program should be combined with the monitoring process so that warning signals can be issued in advance of the collapse, The whole monitoring process including the alert giving can be managed using a personal computer. A flowchart to show this management is also proposed herein. Finally, a site test has been performed, and the test result indicates that the suggested monitoring method is basically applicable. (C) 2000 Elsevier Science Ltd. All rights reserved

    Pd/Oxide/InGaP MOS Schottky Hydrogen Sensor with Native Thin Oxide

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    Two Chinese Herbal Regimens Safe for the Elderly on Inhibiting Liver and Bladder Tumor Cell Growth and Regulating Gene Expression

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    Background: Cancers have become one of the most lethal diseases in elders. In traditional Chinese medicine, Tan-Chih-Hsiao-Yao-San (TCHYS) and Long-Daan-Shiah-Gan-Tang (LDSGT) are used to treat cancers. However, the growth-inhibitory effects and gene expression profiles of these drugs on cancer cells are still unclear. Methods: This study assessed the effects of TCHYS and LDSGT on viability of liver and bladder tumor cells, and bladder TCCSUP cells were further subjected to profile gene expression patterns with microarray technology for identifying gene candidates that may be involved in the tumorigenesis. Results: The results revealed that both drugs significantly eliminated the growth of Chang liver and three hepatoma cells. On the contrary, the embryonic liver WRL68 cells showed less response to the treatments, whereas the control agent genistein had much higher inhibitory effect in WRL68 cells than in the other hepatoma cells. Both TCHYS and LDSGT, as well as cisplatin and paclitaxel, exhibited dose-dependent suppression on the viability of all bladder cancer cells. To characterize the possible regulation for such effects, the profiling of gene expression was performed with complementary DNA chips. When bladder transitional cell carcinoma (TCC) TCCSUP cells were treated with TCHYS, 29 upregulated and 28 downregulated genes were detected; whereas 54 genes were upregulated in the same cells treated with LDSGT. Moreover, the detected gene expression patterns were also confirmed by using the reverse transcription-polymerase chain reaction assay. Conclusion: This study initiates the evaluations of drug efficacies and gene expression profiles of traditional Chinese medicines, which may provide important information and identify useful biomarkers for treating cancers. Copyright (C) 2011, Taiwan Society of Geriatric Emergency & Critical Care Medicine. Published by Elsevier Taiwan LLC. All rights reserved

    Characterization of the Possible Roles for B Class MADS Box Genes in Regulation of Perianth Formation in Orchid1[C]

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    To investigate sepal/petal/lip formation in Oncidium Gower Ramsey, three paleoAPETALA3 genes, O. Gower Ramsey MADS box gene5 (OMADS5; clade 1), OMADS3 (clade 2), and OMADS9 (clade 3), and one PISTILLATA gene, OMADS8, were characterized. The OMADS8 and OMADS3 mRNAs were expressed in all four floral organs as well as in vegetative leaves. The OMADS9 mRNA was only strongly detected in petals and lips. The mRNA for OMADS5 was only strongly detected in sepals and petals and was significantly down-regulated in lip-like petals and lip-like sepals of peloric mutant flowers. This result revealed a possible negative role for OMADS5 in regulating lip formation. Yeast two-hybrid analysis indicated that OMADS5 formed homodimers and heterodimers with OMADS3 and OMADS9. OMADS8 only formed heterodimers with OMADS3, whereas OMADS3 and OMADS9 formed homodimers and heterodimers with each other. We proposed that sepal/petal/lip formation needs the presence of OMADS3/8 and/or OMADS9. The determination of the final organ identity for the sepal/petal/lip likely depended on the presence or absence of OMADS5. The presence of OMADS5 caused short sepal/petal formation. When OMADS5 was absent, cells could proliferate, resulting in the possible formation of large lips and the conversion of the sepal/petal into lips in peloric mutants. Further analysis indicated that only ectopic expression of OMADS8 but not OMADS5/9 caused the conversion of the sepal into an expanded petal-like structure in transgenic Arabidopsis (Arabidopsis thaliana) plants
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