201 research outputs found

    Further investigations of linear trirhodium complexes: experimental and theoretical studies of Rh-3(dpa)(4)Cl-2 and Rh-3(dpa)(4)Cl-2 (BF4) dpa = bis(2-pyridyl)amido anion

    Get PDF
    The linear trirhodium compound, Rh-3(dpa)(4)Cl-2 (1), and its one-electron oxidation product, [Rh-3(dpa)(4)Cl-2]BF4 (2), have been synthesized and studied extensively. The magnetic measurement for compound 1 shows that it possesses one unpaired electron that is assigned to occupy the sigma(nb) orbital ((2)A(2)) by DFT calculations. Upon oxidation, a beta-spin electron of 1 is removed, that causes compound 2 to exhibit a triplet ground state. DFT calculations indicate that the two unpaired electrons of 2 occupy sigma(nb) and delta* orbitals (B-3(1)), which is supported by H-1 NMR spectrum. Unlike their isoelectronic analogues [Co-3(dpa)(4)Cl-2] (3) and [Co-3(dpa)(4)(Cl)(2)]BF4 (4), both compound 1 and 2 do not display the spin-crossover phenomenon. The reason may be attributed to the relative large energy gap between B-3(1) and open-shell singlet B-1(1) states

    Epidemiology of invasive fungal diseases among patients with haematological disorders in the Asia-Pacific: a prospective observational study

    Get PDF
    AbstractWe conducted a 2-year multicentre prospective observational study to determine the epidemiology of and mortality associated with invasive fungal diseases (IFDs) among patients with haematological disorders in Asia. Eleven institutions from 8 countries/regions participated, with 412 subjects (28.2% possible, 38.3% probable and 33.5% proven IFDs) recruited. The epidemiology of IFDs in participating institutions was similar to Western centres, with Aspergillus spp. (65.9%) or Candida spp. (26.7%) causing the majority of probable and proven IFDs. The overall 30-day mortality was 22.1%. Progressive haematological disorder (odds ratio [OR] 5.192), invasive candidiasis (OR 3.679), and chronic renal disease (OR 6.677) were independently associated with mortality

    Role of calcineurin in Porphyromonas gingivalis-induced myocardial cell hypertrophy and apoptosis

    Get PDF
    Background and objective: Periodontal pathogen Porphyromonas gingivalis (P. gingivalis) increased cardiomyocyte hypertrophy and apoptosis whereas Actinobaeillus actinomycetemcomitans and Prevotella intermedia had no effects. The purpose of this study is to clarify the role of calcineurin signaling pathway in P. gingivalis-induced H9c2 myocardial cell hypertrophy and apoptosis. Methods: DNA fragmentation, nuclear condensation, cellular morphology, calcineurin protein, Bcl2- associated death promoter (Bad) and nuclear factor of activated T cell (NFAT)-3 protein products in cultured H9c2 myocardial cell were measured by agarose gel electrophoresis, DAPI, immunofluorescence, and Western blotting following P. gingivalis and/or pre-administration of CsA (calcineurin inhibitors cyclosporin A). Results: P. gingivalis not only increased calcineurin protein, NFAT-3 protein products and cellular hypertrophy, but also increased DNA fragmentation, nuclear condensation and Bad protein products in H9c2 cells. The increased cellular sizes, DNA fragmentation, nuclear condensation, and Bad of H9c2 cells treated with P. gingivalis were all significantly reduced after pre-administration of CsA. Conclusion: Our findings suggest that the activity of calcineurin signal pathway may be initiated by P. gingivalis and further lead to cell hypertrophy and death in culture H9c2 myocardial cells

    Measurement of Cosmic-ray Muon-induced Spallation Neutrons in the Aberdeen Tunnel Underground Laboratory

    Get PDF
    AbstractMuon-induced neutrons are one of the major backgrounds to various underground experiments, such as dark matter searches, low-energy neutrino oscillation experiments and neutrino-less double beta-decay experiments. Previous experiments on the underground production rate of muon-induced neutrons were mostly carried out either at shallow sites or at very deep sites. The Aberdeen Tunnel experiment aims to measure the neutron production rate at a moderate depth of 611 meters water equivalent. Our apparatus comprises of six layers of plastic-scintillator hodoscopes for tracking the incident cosmic-ray muons, and 760 L of gadolinium-doped liquid-scintillator for both neutron production and detection targets. In this paper, we describe the design and the performance of the apparatus. The preliminary result on the measurement of neutron production rate is also presented

    Protons in near earth orbit

    Get PDF
    The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

    Search for antihelium in cosmic rays

    Get PDF
    The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure

    A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

    Get PDF
    The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the 100MeV\sim 100 \mathrm{MeV} to 1TeV1 \mathrm{TeV} range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected 10810^8 cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary π\pi^- and μ\mu^- emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change

    Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

    Get PDF

    The Physics of the B Factories

    Get PDF

    Search for the Zγ decay mode of new high-mass resonances in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    This letter presents a search for narrow, high-mass resonances in the Zγ final state with the Z boson decaying into a pair of electrons or muons. The √s = 13 TeV pp collision data were recorded by the ATLAS detector at the CERN Large Hadron Collider and have an integrated luminosity of 140 fb−1. The data are found to be in agreement with the Standard Model background expectation. Upper limits are set on the resonance production cross section times the decay branching ratio into Zγ. For spin-0 resonances produced via gluon–gluon fusion, the observed limits at 95% confidence level vary between 65.5 fb and 0.6 fb, while for spin-2 resonances produced via gluon–gluon fusion (or quark–antiquark initial states) limits vary between 77.4 (76.1) fb and 0.6 (0.5) fb, for the mass range from 220 GeV to 3400 GeV
    corecore