508 research outputs found

    Spectroscopy of the neutron-rich actinide nucleus U-240 following multinucleon-transfer reactions

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    B. Birkenbach et al.; 9 pags.; 9 figs.; 2 tabs.; PACS number(s): 23.20.Lv, 25.70.Hi, 27.90.+b, 29.40.GxBackground: Nuclear structure information for the neutron-rich actinide nuclei is important since it is the benchmark for theoretical models that provide predictions for the heaviest nuclei. Purpose: gamma-ray spectroscopy of neutron-rich heavy nuclei in the actinide region. Method: Multinucleon-transfer reactions in Zn-70 + U-238 and Xe-136 + U-238 have been measured in two experiments performed at the INFN Legnaro, Italy. In the Zn-70 experiment the high-resolution HPGe Clover Array (CLARA) coupled to the magnetic spectrometer PRISMA was employed. In the Xe-136 experiment the high-resolution Advanced Gamma Tracking Array (AGATA) was used in combination with PRISMA and the Detector Array for Multinucleon Transfer Ejectiles (DANTE). Results: The ground-state band (g.s. band) of U-240 was measured up to the 20(+) level and a tentative assignment was made up to the (24(+)) level. Results from gamma gamma coincidence and from particle coincidence analyses are shown. Moments of inertia (MoI) show a clear upbend. Evidence for an extended first negative-parity band of U-240 is found. Conclusions: A detailed comparison with latest calculations shows best agreement with cranked relativistic Hartree-Bogoliubov (CRHB) calculations for the g.s. band properties. The negative-parity band shows the characteristics of a K-pi = 0 band based on an octupole vibration. ©2015 American Physical SocietyThe research leading to these results has received funding from the German Bundesministerium fur Bildung ¨ und Forschung (BMBF) under Contract No. 05P12PKFNE TP4, the European Union Seventh Framework Programme (FP7/2007-2013) under Grant No. 262010-ENSAR, and the Spanish Ministerio de Ciencia e Innovacion under Contract No. FPA2011-29854-C04. A.V. thanks the Bonn-Cologne Graduate School of Physics and Astronomy (BCGS) for financial support. One of the authors (A. Gadea) was supported by MINECO, Spain, under Grants No. FPA2011-29854-C04 759 and No. FPA2014-57196-C5; Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019; and EU under the FEDER program.Peer Reviewe

    Lifetime measurements in 63^{63}Co and 65^{65}Co

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    Lifetimes of the 9/219/2^-_1 and 3/213/2^-_1 states in 63^{63}Co and the 9/219/2^-_1 state in 65^{65}Co were measured using the recoil distance Doppler shift and the differential decay curve methods. The nuclei were populated by multi-nucleon transfer reactions in inverse kinematics. Gamma rays were measured with the EXOGAM Ge array and the recoiling fragments were fully identified using the large-acceptance VAMOS spectrometer. The E2 transition probabilities from the 3/213/2^-_1 and 9/219/2^-_1 states to the 7/27/2^- ground state could be extracted in 63^{63}Co as well as an upper limit for the 9/217/219/2^-_1\rightarrow7/2^-_1 BB(E2) value in 65^{65}Co. The experimental results were compared to large-scale shell-model calculations in the pfpf and pfg9/2pfg_{9/2} model spaces, allowing to draw conclusions on the single-particle or collective nature of the various states.Comment: 8 pages, 8 figures, 1 table, accepted for publication in Physical Review

    Multi-Phonon γ\gamma-Vibrational Bands and the Triaxial Projected Shell Model

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    We present a fully quantum-mechanical, microscopic, unified treatment of ground-state band and multi-phonon γ\gamma-vibrational bands using shell model diagonalization with the triaxial projected shell model. The results agree very well with data on the g- and γ\gamma-band spectra in 156170^{156-170}Er, as well as with recently measured 4+4^+ 2-phonon γ\gamma-bandhead energies in 166^{166}Er and 168^{168}Er. Multi-phonon γ\gamma-excitation energies are predicted.Comment: 4 pages, 4 figures, submitted to Phys. Lett.

    Vancomycin versus Placebo for Treating Persistent Fever in Patients with Neutropenic Cancer Receiving Piperacillin-Tazobactam Monotherapy

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    This prospective, double-blind trial assessed whether the addition of a glycopeptide would be able to reduce the time to defervescence in neutropenic patients with cancer who had persistent fever 48-60 h after the initiation of empirical piperacillin-tazobactam monotherapy. Of 763 eligible patients, 165 with persistent fever were randomized to receive piperacillin-tazobactam therapy plus either vancomycin therapy or placebo. Defervescence was observed in 82 (95%) of 86 patients in the vancomycin group and in 73 (92%) of 79 patients in the placebo group (P = .52). The distributions of the time to defervescence were not statistically significant between the 2 groups (estimated hazard ratio, 1.03; 95% confidence interval, 0.75-1.43; P = .75). The number of additional episodes of gram-positive bacteremia and the percentage of patients for whom amphotericin B was empirically added to their therapy regimen were also similar in both groups. This study failed to demonstrate that the empirical addition of vancomycin therapy to the treatment regimen is of benefit to persistently febrile neutropenic patients with cance

    Comparative activity of carbapenem testing (the COMPACT study) in Turkey

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    <p>Abstract</p> <p>Background</p> <p>Recent evidence indicates that Gram-negative bacterial pathogens, the most common of which are <it>Pseudomonas </it>spp., <it>Enterobacteriaceae</it>, and <it>Acinetobacter baumannii</it>, are frequent causes of hospital-acquired infections. This study aims to evaluate the in vitro activity of doripenem and comparator carbapenem antibiotics against Gram-negative clinical isolates collected from COMParative Activity of Carbapenem Testing (COMPACT) study centres in Turkey.</p> <p>Methods</p> <p>Ten centres in Turkey were invited to submit <it>Pseudomonas aeruginosa</it>, <it>Enterobacteriaceae</it>, and other Gram-negative isolates from intensive care unit (ICU)/non-ICU patients with complicated intra-abdominal infections, bloodstream infections, or nosocomial pneumonia, including ventilator-associated pneumonia, between May and October 2008. Susceptibility was determined by each centre using E-test. A central laboratory performed species confirmation as well as limited susceptibility and quality-control testing.</p> <p>Results</p> <p>Five hundred and ninety six isolates were collected. MIC<sub>90 </sub>values for doripenem, meropenem, and imipenem, respectively, were 32, ≥ 64, and ≥ 64 mg/L against <it>Pseudomonas </it>spp.; 0.12, 0.12, and 0.5 mg/L against <it>Enterobacteriaceae</it>; and ≥ 64 mg/L for each against other Gram-negative isolates. In determining the susceptibility of hospital isolates of selected Gram-negative pathogens to doripenem, imipenem, and meropenem, we found that against all pathogens combined, the MIC<sub>90 </sub>for ICU compared with non-ICU isolates was higher.</p> <p>Conclusions</p> <p>Doripenem showed similar or slightly better activity than meropenem and better activity than imipenem against the Gram-negative pathogens collected in Turkey.</p

    A Typology of Child Sponsorship Activity

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    Framing the debate over child sponsorship in terms of legitimacy and changing perceptions of credible international humanitarian interventions, this chapter takes exception to the tendency of child sponsorship critics to assume that sponsorship funded activity is much the same everywhere and similar today when compared to sponsorship practice in the past. Mindful of ongoing critique of child sponsorship, this chapter seeks to position those international non-governmental organisations that utilise child sponsorship to fund interventions, in a landscape of contested ideas. It argues that informed critique of child sponsorship is best achieved through a typology of funded interventions. Four key types of sponsorship funded activity are identified as emerging over time, some of which are currently deemed to be less legitimate in terms of poverty reduction and are best seen as welfare measures aimed at individual children rather than community development or advocacy activities

    Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway

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    <p>Abstract</p> <p>Background</p> <p>Increasing reports of carbapenem resistant <it>Acinetobacter baumannii </it>infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of <it>A. baumannii </it>isolates, by comparing to the validated test methods.</p> <p>Methods</p> <p>Selected 112 clinical isolates of <it>A. baumanii </it>collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD), disk diffusion (DD), Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test.</p> <p>Results</p> <p>MicroScan performed true identification of all <it>A. baumannii </it>strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78%) were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%). Vitek 2 produced eight minor errors(7.2%). BD Phoenix produced three major errors (2.8%). DD produced two very major errors (1.8%) (slightly higher (0.3%) than the acceptable limit) and three major errors (2.7%). MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25%) and 50 minor errors (44.6%).</p> <p>Conclusion</p> <p>Reporting errors for <it>A. baumannii </it>against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility testing method to validate imipenem susceptibility. Etest, whereever available, may be used as an easy method to confirm imipenem susceptibility.</p
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