231 research outputs found

    Cardiomyocyte ionic currents in intact young and aged murine Pgc-1β-/- atrial preparations.

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    INTRODUCTION: Recent studies reported that energetically deficient murine Pgc-1β-/- hearts replicate age-dependent atrial arrhythmic phenotypes associated with their corresponding clinical conditions, implicating action potential (AP) conduction slowing consequent upon reduced AP upstroke rates. MATERIALS AND METHODS: We tested a hypothesis implicating Na+ current alterations as a mechanism underlying these electrophysiological phenotypes. We applied loose patch-clamp techniques to intact young and aged, WT and Pgc-1β-/-, atrial cardiomyocyte preparations preserving their in vivo extracellular and intracellular conditions. RESULTS AND DISCUSSION: Depolarising steps activated typical voltage-dependent activating and inactivating inward (Na+) currents whose amplitude increased or decreased with the amplitudes of the activating, or preceding inactivating, steps. Maximum values of peak Na+ current were independently influenced by genotype but not age or interacting effects of genotype and age on two-way ANOVA. Neither genotype, nor age, whether independently or interactively, influenced voltages at half-maximal current, or steepness factors, for current activation and inactivation, or time constants for recovery from inactivation following repolarisation. In contrast, delayed outward (K+) currents showed similar activation and rectification properties through all experimental groups. These findings directly demonstrate and implicate reduced Na+ in contrast to unchanged K+ current, as a mechanism for slowed conduction causing atrial arrhythmogenicity in Pgc-1β-/- hearts

    Measurement of proton electromagnetic form factors in e+eppˉe^+e^- \to p\bar{p} in the energy region 2.00-3.08 GeV

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    The process of e+eppˉe^+e^- \rightarrow p\bar{p} is studied at 22 center-of-mass energy points (s\sqrt{s}) from 2.00 to 3.08 GeV, exploiting 688.5~pb1^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section~(σppˉ\sigma_{p\bar{p}}) of e+eppˉe^+e^- \rightarrow p\bar{p} is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (GE/GM|G_{E}/G_{M}|) and the value of the effective (Geff|G_{\rm{eff}}|), electric (GE|G_E|) and magnetic (GM|G_M|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. GE/GM|G_{E}/G_{M}| and GM|G_M| are determined with high accuracy, providing uncertainties comparable to data in the space-like region, and GE|G_E| is measured for the first time. We reach unprecedented accuracy, and precision results in the time-like region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on non-perturbative Quantum Chromodynamics

    Search for the decay J/ψγ+invisibleJ/\psi\to\gamma + \rm {invisible}

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    We search for J/ψJ/\psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψJ/\psi produced through the process ψ(3686)π+πJ/ψ\psi(3686)\to\pi^+\pi^-J/\psi in a data sample of (448.1±2.9)×106(448.1\pm2.9)\times 10^6 ψ(3686)\psi(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2  GeV/c2\mathrm{\ Ge\kern -0.1em V}/c^2. The upper limit corresponding to an invisible particle with zero mass is 7.0×107\times 10^{-7} at the 90\% confidence level

    Precise Measurements of Branching Fractions for Ds+D_s^+ Meson Decays to Two Pseudoscalar Mesons

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    We measure the branching fractions for seven Ds+D_{s}^{+} two-body decays to pseudo-scalar mesons, by analyzing data collected at s=4.1784.226\sqrt{s}=4.178\sim4.226 GeV with the BESIII detector at the BEPCII collider. The branching fractions are determined to be B(Ds+K+η)=(2.68±0.17±0.17±0.08)×103\mathcal{B}(D_s^+\to K^+\eta^{\prime})=(2.68\pm0.17\pm0.17\pm0.08)\times10^{-3}, B(Ds+ηπ+)=(37.8±0.4±2.1±1.2)×103\mathcal{B}(D_s^+\to\eta^{\prime}\pi^+)=(37.8\pm0.4\pm2.1\pm1.2)\times10^{-3}, B(Ds+K+η)=(1.62±0.10±0.03±0.05)×103\mathcal{B}(D_s^+\to K^+\eta)=(1.62\pm0.10\pm0.03\pm0.05)\times10^{-3}, B(Ds+ηπ+)=(17.41±0.18±0.27±0.54)×103\mathcal{B}(D_s^+\to\eta\pi^+)=(17.41\pm0.18\pm0.27\pm0.54)\times10^{-3}, B(Ds+K+KS0)=(15.02±0.10±0.27±0.47)×103\mathcal{B}(D_s^+\to K^+K_S^0)=(15.02\pm0.10\pm0.27\pm0.47)\times10^{-3}, B(Ds+KS0π+)=(1.109±0.034±0.023±0.035)×103\mathcal{B}(D_s^+\to K_S^0\pi^+)=(1.109\pm0.034\pm0.023\pm0.035)\times10^{-3}, B(Ds+K+π0)=(0.748±0.049±0.018±0.023)×103\mathcal{B}(D_s^+\to K^+\pi^0)=(0.748\pm0.049\pm0.018\pm0.023)\times10^{-3}, where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode Ds+K+Kπ+D_s^+\to K^+K^-\pi^+. Precision of our measurements is significantly improved compared with that of the current world average values

    Newly defined ATP-binding cassette subfamily B member 5 positive dermal mesenchymal stem cells promote healing of chronic iron-overload wounds via secretion of interleukin-1 receptor antagonist

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    In this study, we report the beneficial effects of a newly identified dermal cell subpopulation expressing the ATP‐binding cassette subfamily B member 5 (ABCB5) for the therapy of nonhealing wounds. Local administration of dermal ABCB5+‐derived mesenchymal stem cells (MSCs) attenuated macrophage‐dominated inflammation and thereby accelerated healing of full‐thickness excisional wounds in the iron‐overload mouse model mimicking the nonhealing state of human venous leg ulcers. The observed beneficial effects were due to interleukin‐1 receptor antagonist (IL‐1RA) secreted by ABCB5+‐derived MSCs, which dampened inflammation and shifted the prevalence of unrestrained proinflammatory M1 macrophages toward repair promoting anti‐inflammatory M2 macrophages at the wound site. The beneficial anti‐inflammatory effect of IL‐1RA released from ABCB5+‐derived MSCs on human wound macrophages was conserved in humanized NOD‐scid IL2rγ null mice. In conclusion, human dermal ABCB5+ cells represent a novel, easily accessible, and marker‐enriched source of MSCs, which holds substantial promise to successfully treat chronic nonhealing wounds in humans

    Synthesis and characterization of CuO nanowires by a simple wet chemical method

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    We report a successful synthesis of copper oxide nanowires with an average diameter of 90 nm and lengths of several micrometers by using a simple and inexpensive wet chemical method. The CuO nanowires prepared via this method are advantageous for industrial applications which require mass production and low thermal budget technique. It is found that the concentration and the quantity of precursors are the critical factors for obtaining the desired one-dimensional morphology. Field emission scanning electron microscopy images indicate the influence of thioglycerol on the dispersity of the prepared CuO nanowires possibly due to the stabilization effect of the surface caused by the organic molecule thioglycerol. The Fourier transform infrared spectrum analysis, energy dispersive X-ray analysis, X-ray diffraction analysis, and X-ray photoemission spectrum analysis confirm clearly the formation of a pure phase high-quality CuO with monoclinic crystal structure

    Observation of a structure in e+eϕηe^+e^- \to \phi \eta^{\prime} at s\sqrt{s} from 2.05 to 3.08 GeV

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    The process e+eϕηe^{+}e^{-} \to \phi \eta^{\prime} has been studied for the first time in detail using data sample collected with the BESIII detector at the BEPCII collider at center of mass energies from 2.05 to 3.08 GeV. A resonance with quantum numbers JPC=1J^{PC}=1^{--} is observed with mass MM = (2177.5 ±\pm 4.8 (stat) ±\pm 19.5 (syst)) MeV/c2{ \it{c}^{\mathrm{2}}} and width Γ\Gamma = (149.0 ±\pm 15.6 (stat) ±\pm 8.9 (syst)) MeV with a statistical significance larger than 10σ\sigma. The observed structure could be identified with the ϕ(2170)\phi(2170), then the ratio of partial width between the ϕη\phi \eta^{\prime} by BESIII and ϕη\phi \eta by BABAR is (BϕηRΓeeR)/(BϕηRΓeeR)\mathcal{B}^{R}_{\phi \eta}\Gamma^{R}_{ee})/{(\mathcal{B}^{R}_{\phi \eta^{\prime}}\Gamma^{R}_{ee})} = 0.23 ±\pm 0.10 (stat) ±\pm 0.18 (syst), which is smaller than the prediction of the ssˉgs\bar{s}g hybrid models by several orders of magnitude

    Measurements of the absolute branching fractions of D0(+)KKˉππD^{0(+)}\to K\bar K\pi\pi decays

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    Based on 2.93~fb1^{-1} e+ee^+e^- collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report the measurements of the absolute branching fractions of D0K+Kπ0π0D^0\to K^+K^-\pi^0\pi^0, D0KS0KS0π+πD^0\to K^0_SK^0_S\pi^+\pi^-, D0KS0Kπ+π0D^0\to K^0_SK^-\pi^+\pi^0, D0KS0K+ππ0D^0\to K^0_SK^+\pi^-\pi^0, D+K+Kπ+π0D^+\to K^+K^-\pi^+\pi^0, D+KS0K+π0π0D^+\to K^0_SK^+\pi^0\pi^0, D+KS0Kπ+π+D^+\to K^0_SK^-\pi^+\pi^+, D+KS0K+π+πD^+\to K^0_SK^+\pi^+\pi^-, and D+KS0KS0π+π0D^+\to K^0_SK^0_S\pi^+\pi^0. The decays D0K+Kπ0π0D^0\to K^+K^-\pi^0\pi^0, D0KS0Kπ+π0D^0\to K^0_SK^-\pi^+\pi^0, D0KS0K+ππ0D^0\to K^0_SK^+\pi^-\pi^0, D+KS0KS0π+π0D^+\to K^0_SK^0_S\pi^+\pi^0, and D+KS0K+π0π0D^+\to K^0_SK^+\pi^0\pi^0 are observed for the first time. The branching fractions of the decays D0KS0KS0π+πD^0\to K^0_SK^0_S\pi^+\pi^-, D+K+Kπ+π0D^+\to K^+K^-\pi^+\pi^0, D+KS0Kπ+π+D^+\to K^0_SK^-\pi^+\pi^+, and D+KS0K+π+πD^+\to K^0_SK^+\pi^+\pi^- are measured with improved precision compared to the world-average values.Comment: 11 pages, 5 figure

    Model-independent determination of the relative strong-phase difference between D0D^0 and Dˉ0KS,L0π+π\bar{D}^0\rightarrow K^0_{S,L}\pi^+\pi^- and its impact on the measurement of the CKM angle γ/ϕ3\gamma/\phi_3

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    Crucial inputs for a variety of CPCP-violation studies can be determined through the analysis of pairs of quantum-entangled neutral DD mesons, which are produced in the decay of the ψ(3770)\psi(3770) resonance. The relative strong-phase parameters between D0D^0 and Dˉ0\bar{D}^0 in the decays D0KS,L0π+πD^0\rightarrow K^0_{S,L}\pi^+\pi^- are studied using 2.93~fb1{\rm fb}^{-1} of e+ee^+e^- annihilation data delivered by the BEPCII collider and collected by the BESIII detector at a center-of-mass energy of 3.773 GeV. Results are presented in regions of the phase space of the decay. These are the most precise measurements to date of the strong-phase parameters in DKS,L0π+πD \to K_{S,L}^0\pi^+\pi^- decays. Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle γ/ϕ3\gamma/\phi_3 is expected to be between 0.70.7^\circ and 1.21.2^\circ, for an analysis using the decay B±DK±B^{\pm}\rightarrow DK^{\pm}, DKS0π+πD\rightarrow K^0_S\pi^+\pi^-, where DD represents a superposition of D0D^0 and D0ˉ\bar{D^0} states. This is a factor of three smaller than that achievable with previous measurements. Furthermore, these results provide valuable input for charm-mixing studies, other measurements of CPCP violation, and the measurement of strong-phase parameters for other DD-decay modes.Comment: 34 pages, 10 figure

    Search for the semileptonic decay D0(+)b1(1235)(0)e+νeD^{0(+)}\to b_1(1235)^{-(0)} e^+\nu_e

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    Using 2.93 fb12.93~\mathrm{fb}^{-1} of e+ee^+e^- annihilation data collected at a center-of-mass energy s=3.773\sqrt{s}=3.773 GeV with the BESIII detector operating at the BEPCII collider, we search for the semileptonic D0(+)D^{0(+)} decays into a b1(1235)(0)b_1(1235)^{-(0)} axial-vector meson for the first time. No significant signal is observed for either charge combination. The upper limits on the product branching fractions are BD0b1(1235)e+νeBb1(1235)ωπ<1.12×104{\mathcal B}_{D^0\to b_1(1235)^- e^+\nu_e}\cdot {\mathcal B}_{b_1(1235)^-\to \omega\pi^-}<1.12\times 10^{-4} and BD+b1(1235)0e+νeBb1(1235)0ωπ0<1.75×104{\mathcal B}_{D^+\to b_1(1235)^0 e^+\nu_e}\cdot {\mathcal B}_{b_1(1235)^0\to \omega\pi^0}<1.75\times 10^{-4} at the 90\% confidence level.Comment: 9 pages, 3 figure
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