359 research outputs found

    Pu-Erh tea and GABA attenuates oxidative stress in kainic acid-induced status epilepticus

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Pu-Erh tea is one of the most-consumed beverages due to its taste and the anti-anxiety-producing effect of the gamma-aminobutyric acid (GABA) if contains. However the protective effects of Pu-Erh tea and its constituent, GABA to kainic acid (KA)-induced seizure have not been fully investigated.</p> <p>Methods</p> <p>We analyzed the effect of Pu-Erh tea leaf (PETL) and GABA on KA-induced neuronal injury <it>in vivo </it>and <it>in vitro</it>.</p> <p>Results</p> <p>PETL and GABA reduced the maximal seizure classes, predominant behavioral seizure patterns, and lipid peroxidation in male FVB mice with status epilepticus. PETL extracts and GABA were effective in protecting KA-treated PC12 cells in a dose-dependent manner and they decreased Ca<sup>2+ </sup>release, ROS production and lipid peroxidation from KA-stressed PC12 cells. Western blot results revealed that mitogen-activated protein kinases (MAPKs), RhoA and cyclo-oxygenase-2 (COX-2) expression were increased in PC12 cells under KA stress, and PETL and GABA significantly reduced COX-2 and p38 MAPK expression, but not that of RhoA. Furthermore, PETL and GABA reduced PGE<sub>2 </sub>production from KA-induced PC12 cells.</p> <p>Conclusions</p> <p>Taken together, PETL and GABA have neuroprotective effects against excitotoxins that may have clinical applications in epilepsy.</p

    Flavor and CP Violation with Fourth Generations Revisited

    Full text link
    The Standard Model predicts a very small CP violation phase sin2ΦBsSM0.04\sin2\Phi^{\rm SM}_{B_s} \simeq -0.04%= \arg M_{12} \simeq \arg\,(V^*_{ts}V_{tb})^2in in B_s--\bar B_smixing. mixing. %, i.e. of order \lambda^2\eta.Anyfinitevalueof. Any finite value of \Phi_{B_s}measuredattheTevatronwouldimplyNewPhysics.Withrecenthintsforfinite measured at the Tevatron would imply New Physics. With recent hints for finite \sin2\Phi_{B_s},experimentsattheTevatron,wereconsiderthepossibilityofa4thgeneration.Asrecentdirectsearchboundshavebecomeconsiderablyheavierthan300GeV,wetakethe, % have appeared from CDF and D\O\, experiments at the Tevatron, we reconsider the possibility of a 4th generation. As recent direct search bounds have become considerably heavier than 300 GeV, we take the t'masstobeneartheunitarityboundof500GeV.Combiningthemeasuredvaluesof mass to be near the unitarity bound of 500 GeV. Combining the measured values of \Delta m_{B_s}with with {\cal B}(B \to X_s\ell^+\ell^-),togetherwithtypical, together with typical f_{B_s}values,wefindasizable values, we find a sizable \sin2\Phi^{\rm SM4}_{B_s} \sim -0.33.Using. Using %a typical value of m_{b'} = 480GeV,weextracttherange GeV, we extract the range % a range of values, 0.06 < |V_{t'b}| < 0.13fromtheconstraintsof from the constraints of \Gamma(Z\to b\bar b),, \Delta m_{D}and and {\cal B}(K^+\to\pi^+\nu\bar\nu).Afuturemeasurementof. A future measurement of {\cal B}(K_L\to\pi^0\nu\bar\nu)willdetermine will determine V_{t'd}$.Comment: 8 pages, 11 figure

    Fourth Generation Leptons and Muon g2g-2

    Full text link
    We consider the contributions to gμ2g_\mu-2 from fourth generation heavy neutral and charged leptons, NN and EE, at the one-loop level. Diagrammatically, there are two types of contributions: boson-boson-NN, and EE-EE-boson in the loop diagram. In general, the effect from NN is suppressed by off-diagonal lepton mixing matrix elements. For EE, we consider flavor changing neutral couplings arising from various New Physics models, which are stringently constrained by μeγ\mu\to e\gamma. We assess how the existence of a fourth generation would affect these New Physics models.Comment: Minor changes, with references update

    Mechanics of Optimal Structural Design for Extreme Loads to Peak System Responses

    Get PDF
    [[abstract]]Over the past decades, with the development of modern manufacturing and information technology, demands of smart and economical structural designs have been increasing considerably. Central to this engineering issue is that a good structural design needs to embrace both necessary capabilities to afford critical load distributions and the best arrangement of materials serving the performance criteria using limited resources. Here, a new analysis technique is proposed to achieve optimal structural designs considering peak system responses as design constraints respective to extreme load distributions. We anticipate that the technique will open a door for designing efficient structural systems which satisfy safety requirements under various sophisticated loadings from the environment.[[sponsorship]]Tamkang University[[sponsorship]]Taiwan Association of Wind Engineering[[sponsorship]]Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20151101~20151102[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]New Taipe

    A case of acute appendicitis with Vibrio fluvialis peritonitis

    Get PDF
    AbstractHuman infections caused by Vibrio fluvialis are rarely reported. The most common clinical presentation of V. fluvialis infection is acute gastroenteritis with diarrhea. Reported extra-intestinal infections caused by V. fluvialis have included bacteremia, hemorrhagic cellulitis and cerebritis. Peritonitis is an uncommon clinical presentation of Vibrio infections, and most cases have occurred in patients receiving peritoneal dialysis or those with liver cirrhosis. Herein, we report the first case of acute appendicitis with V. fluvialis peritonitis

    Probing Flavor Changing Neutral Higgs Couplings at LHC

    Get PDF
    Uniquely heavy with mass at the weak scale, the top quark may have large flavor changing couplings to Higgs bosons that are as yet unexplored. We show that such couplings can be directly probed at the LHC through the parton subprocess c(cˉ)gt(tˉ)A0c(\bar c)g \to t (\bar t)A^0, where the pseudoscalar A0A^0 subsequently decays into tcˉt \bar c or tˉc{\bar t} c, giving rise to the intriguing final state of like sign top quark pairs. After demanding ±±\ell^\pm\ell^\pm, missing energy and two bb-jets, the major background turns out to be qqˉWttˉq\bar q' \to Wt \bar t, which can be partially suppressed by jet counting. The signal can then manifest itself in the asymmetry of numbers of ++\ell^+\ell^+ and \ell^-\ell^- events. To further improve the signal over background, efficient tt vs. tˉ\bar t tagging methods should be developed.Comment: 14 pages, REVTEX, 3 figures include

    Overexpression of hTERT increases stem-like properties and decreases spontaneous differentiation in human mesenchymal stem cell lines

    Get PDF
    To overcome loss of stem-like properties and spontaneous differentiation those hinder the expansion and application of human mesenchymal stem cells (hMSCs), we have clonally isolated permanent and stable human MSC lines by ectopic overexpression of primary cell cultures of hMSCs with HPV 16 E6E7 and human telomerase reverse transcriptase (hTERT) genes. These cells were found to have a differentiation potential far beyond the ordinary hMSCs. They expressed trophoectoderm and germline specific markers upon differentiation with BMP4 and retinoic acid, respectively. Furthermore, they displayed higher osteogenic and neural differentiation efficiency than primary hMSCs or hMSCs expressed HPV16 E6E7 alone with a decrease in methylation level as proven by a global CpG island methylation profile analysis. Notably, the demethylated CpG islands were highly associated with development and differentiation associated genes. Principal component analysis further pointed out the expression profile of the cells converged toward embryonic stem cells. These data demonstrate these cells not only are a useful tool for the studies of cell differentiation both for the mesenchymal and neurogenic lineages, but also provide a valuable source of cells for cell therapy studies in animal models of skeletal and neurological disorders

    Flavor Changing Neutral Higgs Couplings and Top-Charm Production at Next Linear Collider

    Get PDF
    We explore the possibility of detecting flavor changing neutral Higgs couplings at the Next Linear Collider (NLC) through e+eνeνeˉtcˉe^+e^-\to \nu_e\bar{\nu_e} t\bar{c}. In the framework of a general two-Higgs doublet model, we perform a complete calculation and find that σ(e+eνeνetcˉ,νeνeˉtˉc)\sigma (e^+e^-\to \nu_e\nu_e t\bar{c}, \nu_e\bar{\nu_e} {\bar t}c) could reach 9\sim 9 fb for s=2TeV\sqrt{s}=2 TeV. This amounts to an annual production of 500 tcˉt\bar{c} plus tˉc\bar{t}c pairs at the NLC with an integrated luminosity of 50 fb1^{-1}. The dependence of tctc-production rate on the neutral scalar mixing angle is mild except when sin2α0or1\sin^2\alpha \to 0 or 1. The ννW+W\nu\nu W^+W^- background should be manageable after bb-tagging, while ννttˉ\nu\nu t\bar t background should not be a problem when the signal event rate is still interesting. The process, together with e+eνeνeˉW+W,νeνeˉZZe^+e^-\to \nu_e\bar{\nu_e} W^+W^-, \nu_e\bar{\nu_e} ZZ studies, offer the chance of measuring the tt-cc-Higgs coupling.Comment: REVTEX, 18 pages, 7 figures; Report number change
    corecore