661 research outputs found

    Glutathione Restores the Mechanism of Synaptic Plasticity in Aged Mice to That of the Adult

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    Glutathione (GSH), the major endogenous antioxidant produced by cells, can modulate the activity of N-methyl-D-aspartate receptors (NMDARs) through its reducing functions. During aging, an increase in oxidative stress leads to decreased levels of GSH in the brain. Concurrently, aging is characterized by calcium dysregulation, thought to underlie impairments in hippocampal NMDAR-dependent long-term potentiation (LTP), a form of synaptic plasticity thought to represent a cellular model for memory

    The 5p15.33 Locus Is Associated with Risk of Lung Adenocarcinoma in Never-Smoking Females in Asia

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    Genome-wide association studies of lung cancer reported in populations of European background have identified three regions on chromosomes 5p15.33, 6p21.33, and 15q25 that have achieved genome-wide significance with p-values of 10−7 or lower. These studies have been performed primarily in cigarette smokers, raising the possibility that the observed associations could be related to tobacco use, lung carcinogenesis, or both. Since most women in Asia do not smoke, we conducted a genome-wide association study of lung adenocarcinoma in never-smoking females (584 cases, 585 controls) among Han Chinese in Taiwan and found that the most significant association was for rs2736100 on chromosome 5p15.33 (p = 1.30×10−11). This finding was independently replicated in seven studies from East Asia totaling 1,164 lung adenocarcinomas and 1,736 controls (p = 5.38×10−11). A pooled analysis achieved genome-wide significance for rs2736100. This SNP marker localizes to the CLPTM1L-TERT locus on chromosome 5p15.33 (p = 2.60×10−20, allelic risk = 1.54, 95% Confidence Interval (CI) 1.41–1.68). Risks for heterozygote and homozygote carriers of the minor allele were 1.62 (95% CI; 1.40–1.87), and 2.35 (95% CI: 1.95–2.83), respectively. In summary, our results show that genetic variation in the CLPTM1L-TERT locus of chromosome 5p15.33 is directly associated with the risk of lung cancer, most notably adenocarcinoma

    Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

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    Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью

    Climate simulations for 1880-2003 with GISS modelE

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    We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. The greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.Comment: 44 pages; 19 figures; Final text accepted by Climate Dynamic

    A New Look at the Scalar Meson f0(500)f_0(500) via D+π+π+νD^+\to \pi^+\pi^-\ell^+\nu_\ell Decays

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    Using 2.93 fb12.93~\mathrm{fb}^{-1} of e+ee^+e^- collision data collected with the BESIII detector at the center-of-mass energy of 3.773 GeV, we investigate the semileptonic decays D+π+π+νD^+\to \pi^+\pi^- \ell^+\nu_\ell (=e\ell=e and μ\mu). The D+f0(500)μ+νμD^+\to f_0(500)\mu^+\nu_\mu decay is observed for the first time. By analyzing simultaneously the differential decay rates of D+f0(500)μ+νμD^+\to f_0(500) \mu^+\nu_\mu and D+f0(500)e+νeD^+\to f_0(500) e^+\nu_e in different +ν\ell^+\nu_\ell four-momentum transfer intervals, the product of the relevant hadronic form factor f+f0(0)f^{f_0}_{+}(0) and the magnitude of the cdc\to d Cabibbo-Kobayashi-Maskawa matrix element Vcd|V_{cd}| is determined to be f+f0(0)Vcd=0.0787±0.0060stat±0.0033systf_{+}^{f_0} (0)|V_{cd}|=0.0787\pm0.0060_{\rm stat}\pm0.0033_{\rm syst} for the first time. With the input of Vcd|V_{cd}| from the global fit in the standard model, we determine f+f0(0)=0.350±0.027stat±0.015systf_{+}^{f_0} (0)=0.350\pm0.027_{\rm stat}\pm0.015_{\rm syst}. The absolute branching fractions of D+f0(500)(π+π)μ+νμD^+\to f_0(500)_{(\pi^+\pi^-)}\mu^+\nu_\mu and D+ρ(π+π)0μ+νμD^+\to \rho^0_{(\pi^+\pi^-)} \mu^+\nu_\mu are determined as (0.72±0.13stat±0.10syst)×103(0.72\pm0.13_{\rm stat}\pm0.10_{\rm syst})\times10^{-3} and (1.64±0.13stat±0.11syst)×103(1.64\pm0.13_{\rm stat}\pm0.11_{\rm syst})\times 10^{-3}. Combining these results with those of previous BESIII measurements on their semielectronic counterparts from the same data sample, we test lepton flavor universality by measuring the branching fraction ratios BD+ρ0μ+νμ/BD+ρ0e+νe=0.88±0.10{\mathcal B}_{D^+\to \rho^0 \mu^+\nu_\mu}/{\mathcal B}_{D^+\to \rho^0 e^+\nu_e}=0.88\pm0.10 and BD+f0(500)μ+νμ/BD+f0(500)e+νe=1.14±0.28{\mathcal B}_{D^+\to f_0(500) \mu^+\nu_\mu}/{\mathcal B}_{D^+\to f_0(500) e^+\nu_e}=1.14\pm0.28, which are compatible with the standard model expectation.Comment: Supplemental Materials added in this versio

    First Observation of a Three-Resonance Structure in e+ee^+e^-\rightarrow{non-open} Charm Hadrons

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    We report the measurement of the cross sections for e+ee^+e^-\rightarrow{nOCH} (nOCH stands for non-open charm hadrons) with improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We observe for the first time a three-resonance structure in the energy-dependent lineshape of the cross sections, which are R(3760)\mathcal R(3760), R(3780)\mathcal R(3780) and R(3810)\mathcal R(3810) with significances of 9.4σ9.4\sigma, 15.7σ15.7\sigma, and 9.8σ9.8\sigma, respectively. The R(3810)\mathcal R(3810) is observed for the first time. We found two solutions in analysis of the cross sections. For solution I [solution II], we measure the mass, the total width and the product of electronic width and nOCH decay branching fraction to be (3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7) [(3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7)] MeV/c2c^2, (11.6±2.6±1.9)(11.6 \pm 2.6 \pm 1.9) [(11.5±2.5±1.8)(11.5 \pm 2.5 \pm 1.8)] MeV, and (10.8±3.2±2.3)(10.8\pm 3.2\pm 2.3) [(11.0±2.9±2.4)(11.0\pm 2.9\pm 2.4)] eV for the R(3810)\mathcal R(3810), respectively. In addition, we measure the branching fractions B(R(3760){\mathcal B}({\mathcal R}(3760)\rightarrow{nOCH})=(24.5±13.4±27.4)%[(6.8±5.4±7.6)%])=(24.5 \pm 13.4 \pm 27.4)\% [(6.8 \pm 5.4 \pm 7.6)\%] for the first time, and B(R(3780){\mathcal B}(\mathcal R(3780)\rightarrow{nOCH})=(11.6±5.8±7.8)%[(10.3±4.5±6.9)%])=(11.6 \pm 5.8 \pm 7.8)\% [(10.3 \pm 4.5 \pm 6.9)\%]. Moreover, we determine the open-charm (OC) branching fraction B(R{\mathcal B}({\mathcal R}(3760)(3760)\rightarrow{OC})=(75.5±13.4±27.4)%[(93.2±5.4±7.6)%])=(75.5 \pm 13.4 \pm 27.4)\% [(93.2 \pm 5.4 \pm 7.6)\%], which supports the interpretation of R(3760)\mathcal R(3760) as an OC pair molecular state, but contained a simple four-quark state component. The first uncertainties are from fits to the cross sections, and the second are systematic

    Study of the doubly Cabibbo-suppressed decays Ds+K+K+πD^+_s\to K^+K^+\pi^- and Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0

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    Based on 7.33 fb1^{-1} of e+ee^+e^- collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, the experimental studies of the doubly Cabibbo-suppressed decays Ds+K+K+πD^+_s\to K^+K^+\pi^- and Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0 are reported. We determine the absolute branching fraction of Ds+K+K+πD^+_s\to K^+K^+\pi^- to be (1.230.25+0.28(stat)±0.06(syst){1.23^{+0.28}_{-0.25}}({\rm stat})\pm0.06({\rm syst})) ×104\times 10^{-4}. No significant signal of Ds+K+K+ππ0D^+_s\to K^+K^+\pi^-\pi^0 is observed and the upper limit on its decay branching fraction at 90\% confidence level is set to be 1.7×1041.7\times10^{-4}.Comment: 10 pages, 4 figures, 4 table

    Search for an invisible muon philic scalar X0X_{0} or vector X1X_{1} via J/ψμ+μ+invisibleJ/\psi\to\mu^+\mu^-+\rm{invisible} decay at BESIII

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    A light scalar X0X_{0} or vector X1X_{1} particles have been introduced as a possible explanation for the (g2)μ(g-2)_{\mu} anomaly and dark matter phenomena. Using (8.998±0.039)×109(8.998\pm 0.039)\times10^9 \jpsi events collected by the BESIII detector, we search for a light muon philic scalar X0X_{0} or vector X1X_{1} in the processes J/ψμ+μX0,1J/\psi\to\mu^+\mu^- X_{0,1} with X0,1X_{0,1} invisible decays. No obvious signal is found, and the upper limits on the coupling g0,1g_{0,1}' between the muon and the X0,1X_{0,1} particles are set to be between 1.1×1031.1\times10^{-3} and 1.0×1021.0\times10^{-2} for the X0,1X_{0,1} mass in the range of 1<M(X0,1)<10001<M(X_{0,1})<1000~MeV/c2/c^2 at 90%\% confidence level.Comment: 9 pages 7 figure

    Observation of the Singly Cabibbo-Suppressed Decay Λc+ΣK+π+\Lambda_{c}^{+}\to \Sigma^{-}K^{+}\pi^{+}

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    The singly Cabibbo-suppressed decay Λc+ΣK+π+\Lambda_{c}^{+}\to \Sigma^{-}K^{+}\pi^{+} is observed for the first time with a statistical significance of 6.4σ6.4\sigma by using 4.5 fb1^{-1} of e+ee^+e^- collision data collected at center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII. The absolute branching fraction of Λc+ΣK+π+\Lambda_{c}^{+}\to \Sigma^{-}K^{+}\pi^{+} is measured to be (3.8±1.3stat±0.2syst)×104(3.8\pm1.3_{\rm stat}\pm0.2_{\rm syst})\times 10^{-4} in a model-independent approach. This is the first observation of a Cabibbo-suppressed Λc+\Lambda_{c}^{+} decay involving Σ\Sigma^- in the final state. The ratio of branching fractions between Λc+ΣK+π+\Lambda_{c}^{+}\to \Sigma^{-}K^{+}\pi^{+} and the Cabibbo-favored decay Λc+Σπ+π+\Lambda_{c}^{+}\to \Sigma^- \pi^+\pi^+ is calculated to be (0.4±0.1)sc2(0.4 \pm 0.1)s_{c}^{2}, where scsinθc=0.2248s_{c} \equiv \sin\theta_c = 0.2248 with θc\theta_c the Cabibbo mixing angle. This ratio significantly deviates from 1.0sc21.0s_{c}^{2} and provides important information for the understanding of nonfactorization contributions in Λc+\Lambda_{c}^{+} decays.Comment: 8 pages, 2 figure
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