2,824 research outputs found

    Semiclassical Quantization for the Spherically Symmetric Systems under an Aharonov-Bohm magnetic flux

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    The semiclassical quantization rule is derived for a system with a spherically symmetric potential V(r)rνV(r) \sim r^{\nu} (2<ν<)(-2<\nu <\infty) and an Aharonov-Bohm magnetic flux. Numerical results are presented and compared with known results for models with ν=1,0,2,\nu = -1,0,2,\infty. It is shown that the results provided by our method are in good agreement with previous results. One expects that the semiclassical quantization rule shown in this paper will provide a good approximation for all principle quantum number even the rule is derived in the large principal quantum number limit n1n \gg 1. We also discuss the power parameter ν\nu dependence of the energy spectra pattern in this paper.Comment: 13 pages, 4 figures, some typos correcte

    Photoresponsive and Ultraviolet to Visible-Light Range Photocatalytic Properties of ZnO:Sb Nanowires

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    100學年度研究獎補助論文[[abstract]]Zinc oxide (ZnO) doped antimony (Sb) nanowires have been synthesized for improving ultraviolet sensing and photocatalytic properties. Upon illumination by UV light (365nm , 2.33mWcm−2 ), the photoelectric current of the ZnO:Sb nanowires exhibited a rapid photoresponse as compared to that of the ZnO nanowires. A highest ratio of photocurrent to dark current of around 48.8-fold was achieved in the as-synthesized ZnO:Sb nanowires. A UV-visible spectrophotometer was used to investigate the absorbance spectrum of the ZnO:Sb nanowires, which exhibited a high absorbance ratio with redshift effect in contrast to that of the ZnO nanowires. Visible-light photocatalysis and UV photoresponsive properties of the ZnO:Sb nanowires are superior to those of the ZnO nanowires.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]電子

    SRSF1-dependent nuclear export of C9ORF72 repeat-transcripts: targeting toxic gain-of-functions induced by protein sequestration as a selective therapeutic strategy for neuroprotection

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    Microsatellite repeat expansions cause several incurable and lethal neurodegenerative disorders including ataxias, myotonic dystrophy, Huntington's disease and C9ORF72-linked amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Abnormal repeat transcripts generated from the expanded loci are substrates of repeat-associated non-AUG (RAN) translation, an unconventional form of translation leading to the production of polymeric repeat proteins with cytotoxic and aggregating properties. The mechanisms involved in the pathogenesis of microsatellite repeat expansion disorders remain a hotly debated topic. They are shared between toxic loss/gain of functions due to intranuclear RNA foci that sequesters RNA-binding proteins and RAN translation of repeat proteins in the cytoplasm. We recently elucidated the molecular mechanism driving the nuclear export of C9ORF72 repeat transcripts and showed for the first time that this pathway can be manipulated to confer neuroprotection. Strikingly, we discovered that intron-retaining C9ORF72 repeat transcripts hijack the physiological NXF1-dependent export pathway by selective RNA-repeat sequestration of SRSF1. Antagonizing SRSF1 and the nuclear export of C9ORF72 repeat transcripts promoted in turn the survival of patient-derived motor neurons and suppressed neurodegeneration-associated motor deficits in Drosophila (Hautbergue et al. Nature Communications 2017; 8:16063). In this invited Research Highlight review, we aim to place this work in the context of our previous studies on the nuclear export of mRNAs, provide a summary of the published research and highlight the significance of these findings as a novel therapeutic strategy for neuroprotection in C9ORF72-ALS/FTD. In addition, we emphasize that protein sequestration, often thought as of inducing loss-of-function mechanisms, can also trigger unwanted protein interactions and toxic gain-of-functions

    System-size scan of dihadron azimuthal correlations in ultra-relativistic heavy ion collisions

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    System-size dependence of dihadron azimuthal correlations in ultra-relativistic heavy ion collision is simulated by a multi-phase transport model. The structure of correlation functions and yields of associated particles show clear participant path-length dependences in collision systems with a partonic phase. The splitting parameter and root-mean-square width of away-side correlation functions increase with collision system size from 14^{14}N+14^{14}N to 197^{197}Au+197^{197}Au collisions. The double-peak structure of away-side correlation functions can only be formed in sufficient "large" collision systems under partonic phase. The contrast between the results with partonic phase and with hadron gas could suggest some hints to study onset of deconfinment.Comment: 8 pages, 4 figures, 1 table; Nucl. Phys. A (accepted

    Mean-field description of ground-state properties of drip-line nuclei. (I) Shell-correction method

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    A shell-correction method is applied to nuclei far from the beta stability line and its suitability to describe effects of the particle continuum is discussed. The sensitivity of predicted locations of one- and two-particle drip lines to details of the macroscopic-microscopic model is analyzed.Comment: 22 REVTeX pages, 13 uuencoded postscript figures available upon reques

    Ethnic differences translate to inadequacy of high-risk screening for gestational diabetes mellitus in an Asian population: a cohort study

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    Background: universal and high-risk screening for gestational diabetes mellitus (GDM) has been widely studied and debated. Few studies have assessed GDM screening in Asian populations and even fewer have compared Asian ethnic groups in a single multi-ethnic population.Methods: 1136 pregnant women (56.7% Chinese, 25.5% Malay and 17.8% Indian) from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort study were screened for GDM by 75-g oral glucose tolerance test (OGTT) at 26–28 weeks of gestation. GDM was defined using the World Health Organization (WHO) criteria. High-risk screening is based on the guidelines of the UK National Institute for Health and Clinical Excellence.Results: universal screening detected significantly more cases than high-risk screening [crude OR 2.2 (95% CI 1.7-2.8)], particularly for Chinese women [crude OR = 3.5 (95% CI 2.5-5.0)]. Pre-pregnancy BMI &gt; 30 kg/m2 (adjusted OR = 3.4, 95% CI 1.5-7.9) and previous GDM history (adjusted OR = 6.6, 95% CI 1.2-37.3) were associated with increased risk of GDM in Malay women while GDM history was the only significant risk factor for GDM in Chinese women (adjusted OR = 4.7, 95% CI 2.0-11.0).Conclusion: risk factors used in high-risk screening do not sufficiently predict GDM risk and failed to detect half the GDM cases in Asian women. Asian women, particularly Chinese, should be screened to avoid under-diagnosis of GDM and thereby optimize maternal and fetal outcome

    Measurement of Hadron and Lepton-Pair Production at 130GeV < \sqrt{s} < 189 GeV at LEP

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    We report on measurements of e+e- annihilation into hadrons and lepton pairs. The data have been collected with the L3 detector at LEP at centre-of-mass energies between 130 and 189 GeV. Using a total integrated luminosity of 243.7 pb^-1, 25864 hadronic and 8573 lepton-pair events are selected for the measurement of cross sections and leptonic forward-backward asymmetries. The results are in good agreement with Standard Model predictions

    Measurement of the Tau Branching Fractions into Leptons

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    Using data collected with the L3 detector near the Z resonance, corresponding to an integrated luminosity of 150pb-1, the branching fractions of the tau lepton into electron and muon are measured to be B(tau->e nu nu) = (17.806 +- 0.104 (stat.) +- 0.076 (syst.)) %, B(tau->mu nu nu) = (17.342 +- 0.110 (stat.) +- 0.067 (syst.)) %. From these results the ratio of the charged current coupling constants of the muon and the electron is determined to be g_mu/g_e = 1.0007 +- 0.0051. Assuming electron-muon universality, the Fermi constant is measured in tau lepton decays as G_F = (1.1616 +- 0.0058) 10^{-5} GeV^{-2}. Furthermore, the coupling constant of the strong interaction at the tau mass scale is obtained as alpha_s(m_tau^2) = 0.322 +- 0.009 (exp.) +- 0.015 (theory)
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