1,119 research outputs found

    The nature of iron-oxygen vacancy defect centers in PbTiO3

    Full text link
    The iron(III) center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c-axis. Its microscopic structure has been analyzed in detail comparing results from a semi-empirical Newman superposition model analysis based on finestructure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B-site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12 K, exhibiting a c/a-ratio of 1.0721.Comment: 11 pages, 5 figures, accepted in Phys. Rev.

    Constraining the Hadronic Contributions to the Muon Anomalous Magnetic Moment

    Full text link
    The mini-proceedings of the Workshop on "Constraining the hadronic contributions to the muon anomalous magnetic moment" which included the "13th meeting of the Radio MonteCarLow WG" and the "Satellite meeting R-Measurements at BES-III" held in Trento from April 10th to 12th, 2013, are presented. This collaboration meeting aims to bring together the experimental e+e- collider communities from BaBar, Belle, BESIII, CMD2, KLOE, and SND, with theorists working in the fields of meson transitions form factors, hadronic contributions to (g-2)_\mu and effective fine structure constant, and development of Monte Carlo generator and Radiative Corrections for precision e+e- and tau physics.Comment: 45 pages, 17 contributions. Editors: P. Masjuan and G. Venanzon

    Safety, tumor trafficking and immunogenicity of chimeric antigen receptor (CAR)-T cells specific for TAG-72 in colorectal cancer.

    Get PDF
    BackgroundT cells engineered to express chimeric antigen receptors (CARs) have established efficacy in the treatment of B-cell malignancies, but their relevance in solid tumors remains undefined. Here we report results of the first human trials of CAR-T cells in the treatment of solid tumors performed in the 1990s.MethodsPatients with metastatic colorectal cancer (CRC) were treated in two phase 1 trials with first-generation retroviral transduced CAR-T cells targeting tumor-associated glycoprotein (TAG)-72 and including a CD3-zeta intracellular signaling domain (CART72 cells). In trial C-9701 and C-9702, CART72 cells were administered in escalating doses up to 1010 total cells; in trial C-9701 CART72 cells were administered by intravenous infusion. In trial C-9702, CART72 cells were administered via direct hepatic artery infusion in patients with colorectal liver metastases. In both trials, a brief course of interferon-alpha (IFN-α) was given with each CART72 infusion to upregulate expression of TAG-72.ResultsFourteen patients were enrolled in C-9701 and nine in C-9702. CART72 manufacturing success rate was 100% with an average transduction efficiency of 38%. Ten patients were treated in CC-9701 and 6 in CC-9702. Symptoms consistent with low-grade, cytokine release syndrome were observed in both trials without clear evidence of on target/off tumor toxicity. Detectable, but mostly short-term (≤14 weeks), persistence of CART72 cells was observed in blood; one patient had CART72 cells detectable at 48 weeks. Trafficking to tumor tissues was confirmed in a tumor biopsy from one of three patients. A subset of patients had 111Indium-labeled CART72 cells injected, and trafficking could be detected to liver, but T cells appeared largely excluded from large metastatic deposits. Tumor biomarkers carcinoembryonic antigen (CEA) and TAG-72 were measured in serum; there was a precipitous decline of TAG-72, but not CEA, in some patients due to induction of an interfering antibody to the TAG-72 binding domain of humanized CC49, reflecting an anti-CAR immune response. No radiologic tumor responses were observed.ConclusionThese findings demonstrate the relative safety of CART72 cells. The limited persistence supports the incorporation of co-stimulatory domains in the CAR design and the use of fully human CAR constructs to mitigate immunogenicity

    Measurement of azimuthal asymmetries in inclusive charged dipion production in e+ee^+e^- annihilations at s\sqrt{s} = 3.65 GeV

    Get PDF
    We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e+eππXe^+e^-\rightarrow \pi\pi X based on a data set of 62 pb1\rm{pb}^{-1} at the center-of-mass energy s=3.65\sqrt{s}=3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.Comment: 7 pages, 5 figure

    Study of D+Kπ+e+νeD^{+} \to K^{-} \pi^+ e^+ \nu_e

    Full text link
    We present an analysis of the decay D+Kπ+e+νeD^{+} \to K^{-} \pi^+ e^+ \nu_e based on data collected by the BESIII experiment at the ψ(3770)\psi(3770) resonance. Using a nearly background-free sample of 18262 events, we measure the branching fraction B(D+Kπ+e+νe)=(3.71±0.03±0.08)%\mathcal{B}(D^{+} \to K^{-} \pi^+ e^+ \nu_e) = (3.71 \pm 0.03 \pm 0.08)\%. For 0.8<mKπ<1.00.8<m_{K\pi}<1.0 GeV/c2c^{2} the partial branching fraction is B(D+Kπ+e+νe)[0.8,1]=(3.33±0.03±0.07)%\mathcal{B}(D^{+} \to K^{-} \pi^+ e^+ \nu_e)_{[0.8,1]} = (3.33 \pm 0.03 \pm 0.07)\%. A partial wave analysis shows that the dominant Kˉ(892)0\bar K^{*}(892)^{0} component is accompanied by an \emph{S}-wave contribution accounting for (6.05±0.22±0.18)%(6.05\pm0.22\pm0.18)\% of the total rate and that other components are negligible. The parameters of the Kˉ(892)0\bar K^{*}(892)^{0} resonance and of the form factors based on the spectroscopic pole dominance predictions are also measured. We also present a measurement of the Kˉ(892)0\bar K^{*}(892)^{0} helicity basis form factors in a model-independent way.Comment: 17 pages, 6 figure

    Confirmation of a charged charmoniumlike state Zc(3885)Z_c(3885)^{\mp} in e+eπ±(DDˉ)e^+e^-\to\pi^{\pm}(D\bar{D}^*)^\mp with double DD tag

    Full text link
    We present a study of the process e+eπ±(DDˉ)e^+e^-\to\pi^{\pm}(D\bar{D}^*)^{\mp} using data samples of 1092~pb1^{-1} at s=4.23\sqrt{s}=4.23~GeV and 826~pb1^{-1} at s=4.26\sqrt{s}=4.26~GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the DD meson pair and the bachelor π±\pi^{\pm} in the final state, we confirm the existence of the charged structure Zc(3885)Z_c(3885)^{\mp} in the (DDˉ)(D\bar{D}^*)^{\mp} system in the two isospin processes e+eπ+D0De^+e^-\to\pi^+D^0D^{*-} and e+eπ+DD0e^+e^-\to\pi^+D^-D^{*0}. By performing a simultaneous fit, the statistical significance of Zc(3885)Zc(3885)^{\mp} signal is determined to be greater than 10σ\sigma, and its pole mass and width are measured to be MpoleM_{\rm{pole}}=(3881.7±\pm1.6(stat.)±\pm1.6(syst.))~MeV/c2c^2 and Γpole\Gamma_{\rm{pole}}=(26.6±\pm2.0(stat.)±\pm2.1(syst.))~MeV, respectively. The Born cross section times the (DDˉ)(D\bar{D}^*)^{\mp} branching fraction (σ(e+eπ±Zc(3885))×Br(Zc(3885)(DDˉ))\sigma(e^+e^-\to\pi^{\pm}Z_{c}(3885)^{\mp}) \times Br(Z_{c}(3885)^{\mp}\to(D\bar{D}^*)^{\mp})) is measured to be (141.6±7.9(stat.)±12.3(syst.)) pb(141.6\pm7.9(\text{stat.})\pm12.3(\text{syst.}))~\text{pb} at s=4.23\sqrt{s}=4.23~GeV and (108.4±6.9(stat.)±8.8(syst.)) pb(108.4\pm6.9(\text{stat.})\pm8.8(\text{syst.}))~\text{pb} at s=4.26\sqrt{s}=4.26~GeV. The polar angular distribution of the π±\pi^{\pm}-Zc(3885)Z_c(3885)^{\mp} system is consistent with the expectation of a quantum number assignment of JP=1+J^P=1^+ for Zc(3885)Z_c(3885)^{\mp}

    Measurement of the e+eπ+π\mathrm e^+\mathrm e^-\rightarrow\mathrm\pi^+\mathrm\pi^- Cross Section between 600 and 900 MeV Using Initial State Radiation

    Get PDF
    We extract the e+eπ+πe^+e^-\rightarrow \pi^+\pi^- cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb1^{-1} taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor Fπ2|F_\pi|^2 as well as the contribution of the measured cross section to the leading order hadronic vacuum polarization contribution to (g2)μ(g-2)_\mu. We find this value to be aμππ,LO(600900  MeV)=(368.2±2.5stat±3.3sys)1010a_\mu^{\pi\pi,\rm LO}(600-900\;\rm MeV) = (368.2 \pm 2.5_{\rm stat} \pm 3.3_{\rm sys})\cdot 10^{-10}.Comment: 14 pages, 7 figures, accepted by PL
    corecore