2,154 research outputs found

    u-RANIA: a neutron detector based on \mu -RWELL technology

    Full text link
    In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL (μ\mu -RWELL) technology. The μ\mu -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B4_4C on the copper surface of the cathode allows the thermal neutrons detection through the release of 7^7Li and α\alpha particles in the active volume. This technology has been developed to be an efficient and convenient alternative to the 3^3He shortage. The goal of the project is to prove the feasibility of such a novel neutron detector by developing and testing small planar prototypes with readout boards suitably segmented with strip or pad read out, equipped with existing electronics or readout in current mode. Preliminary results from the test with different prototypes, showing a good agreement with the simulation, will be presented together with construction details of the prototypes and the future steps of the project.Comment: Prepared for the INSTR20 Conference Proceeding for JINS

    Prune cAMP phosphodiesterase binds nm23-H1 and promotes cancer metastasis

    Get PDF
    We identify a new enzymatic activity underlying metastasis in breast cancer and describe its susceptibility to therapeutic inhibition. We show that human prune (h-prune), a phosphoesterase DHH family appertaining protein, has a hitherto unrecognized cyclic nucleotide phosphodiesterase activity effectively suppressed by dipyridamole, a phosphodiesterase inhibitor. h-prune physically interacts with nm23-H1, a metastasis suppressor gene. The h-prune PDE activity, suppressed by dipyridamole and enhanced by the interaction with nm23-H1, stimulates cellular motility and metastasis processes. Out of 59 metastatic breast cancer cases analyzed, 22 (37%) were found to overexpress h-prune, evidence that this novel enzymatic activity is involved in promoting cancer metastasis

    A model to explain angular distributions of J/ψJ/\psi and ψ(2S)\psi(2S) decays into ΛΛ‾\Lambda\overline{\Lambda} and Σ0Σ‾0\Sigma^0\overline{\Sigma}^0

    Full text link
    BESIII data show a particular angular distribution for the decay of the J/ψJ/\psi and ψ(2S)\psi(2S) mesons into the hyperons ΛΛ‾\Lambda\overline{\Lambda} and Σ0Σ‾0\Sigma^0\overline{\Sigma}^0. More in details the angular distribution of the decay ψ(2S)→Σ0Σ‾0\psi(2S) \to \Sigma^0\overline{\Sigma}^0 exhibits an opposite trend with respect to that of the other three channels: J/ψ→ΛΛ‾J/\psi \to \Lambda\overline{\Lambda}, J/ψ→Σ0Σ‾0J/\psi \to \Sigma^0\overline{\Sigma}^0 and ψ(2S)→ΛΛ‾\psi(2S) \to \Lambda\overline{\Lambda}. We define a model to explain the origin of this phenomenon.Comment: 6 pages, 7 figures, to be published in Chinese Physics

    The Straw Tube Trackers of the PANDA Experiment

    Full text link
    The PANDA experiment will be built at the FAIR facility at Darmstadt (Germany) to perform accurate tests of the strong interaction through bar pp and bar pA annihilation's studies. To track charged particles, two systems consisting of a set of planar, closed-packed, self-supporting straw tube layers are under construction. The PANDA straw tubes will have also unique characteristics in term of material budget and performance. They consist of very thin mylar-aluminized cathodes which are made self-supporting by means of the operation gas-mixture over-pressure. This solution allows to reduce at maximum the weight of the mechanical support frame and hence the detector material budget. The PANDA straw tube central tracker will not only reconstruct charged particle trajectories, but also will help in low momentum (< 1 GeV) particle identification via dE/dx measurements. This is a quite new approach that PANDA tracking group has first tested with detailed Monte Carlo simulations, and then with experimental tests of detector prototypes. This paper addresses the design issues of the PANDA straw tube trackers and the performance obtained in prototype tests.Comment: 7 pages,16 figure

    A Cylindrical GEM Inner Tracker for the BESIII experiment at IHEP

    Full text link
    The Beijing Electron Spectrometer III (BESIII) is a multipurpose detector that collects data provided by the collision in the Beijing Electron Positron Collider II (BEPCII), hosted at the Institute of High Energy Physics of Beijing. Since the beginning of its operation, BESIII has collected the world largest sample of J/{\psi} and {\psi}(2s). Due to the increase of the luminosity up to its nominal value of 10^33 cm-2 s-1 and aging effect, the MDC decreases its efficiency in the first layers up to 35% with respect to the value in 2014. Since BESIII has to take data up to 2022 with the chance to continue up to 2027, the Italian collaboration proposed to replace the inner part of the MDC with three independent layers of Cylindrical triple-GEM (CGEM). The CGEM-IT project will deploy several new features and innovation with respect the other current GEM based detector: the {\mu}TPC and analog readout, with time and charge measurements will allow to reach the 130 {\mu}m spatial resolution in 1 T magnetic field requested by the BESIII collaboration. In this proceeding, an update of the status of the project will be presented, with a particular focus on the results with planar and cylindrical prototypes with test beams data. These results are beyond the state of the art for GEM technology in magnetic field

    Treatment decision-making of secondary prevention after venous thromboembolism. data from the real-life START2-POST-VTE register

    Get PDF
    Patients with venous thromboembolism (VTE) should receive a decision on the duration of anticoagulant treatment (AT) that is often not easy to make. Sixteen Italian clinical centers included patients with recent VTE in the START2-POST-VTE register and reported the decisions taken on duration of AT in each patient and the reasons for them. At the moment of this report, 472 (66.9%) of the 705 patients included in the registry were told to stop AT in 59.3% and to extend it in 40.7% of patients. Anticoagulant treatment lasted ≥3 months in &gt;90% of patients and was extended in patients with proximal deep vein thrombosis because considered at high risk of recurrence or had thrombophilic abnormalities. d-dimer testing, assessment of residual thrombus, and patient preference were also indicated among the criteria influencing the decision. In conclusion, Italian doctors stuck to the minimum 3 months AT after VTE, while the secondary or unprovoked nature of the event was not seen as the prevalent factor influencing AT duration which instead was the result of a complex and multifactorial evaluation of each patient

    Observation of ηc→ωω\eta_c\to\omega\omega in J/ψ→γωωJ/\psi\to\gamma\omega\omega

    Get PDF
    Using a sample of (1310.6±7.0)×106(1310.6\pm7.0)\times10^6 J/ψJ/\psi events recorded with the BESIII detector at the symmetric electron positron collider BEPCII, we report the observation of the decay of the (11S0)(1^1 S_0) charmonium state ηc\eta_c into a pair of ω\omega mesons in the process J/ψ→γωωJ/\psi\to\gamma\omega\omega. The branching fraction is measured for the first time to be B(ηc→ωω)=(2.88±0.10±0.46±0.68)×10−3\mathcal{B}(\eta_c\to\omega\omega)= (2.88\pm0.10\pm0.46\pm0.68)\times10^{-3}, where the first uncertainty is statistical, the second systematic and the third is from the uncertainty of B(J/ψ→γηc)\mathcal{B}(J/\psi\to\gamma\eta_c). The mass and width of the ηc\eta_c are determined as M=(2985.9±0.7±2.1) M=(2985.9\pm0.7\pm2.1)\,MeV/c2c^2 and Γ=(33.8±1.6±4.1) \Gamma=(33.8\pm1.6\pm4.1)\,MeV.Comment: 13 pages, 6 figure

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

    Full text link
    The process of e+e−→ppˉe^+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~pb−1^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section~(σppˉ\sigma_{p\bar{p}}) of e+e−→ppˉe^+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
    • …
    corecore