37 research outputs found

    Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

    Get PDF
    BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

    Prediction of prompt neutron spectra of the photon induced reactions on

    Full text link
    The processing of experimental data for the photon induced reactions on 238U and 232Th investigated by quasi-monochromatic γ-ray beams (produced in Laser Compton scattering at the NewSUBARU facility) needs the prediction of prompt neutron spectra. They are obtained using reliable models and systematics, i.e. the most employed and well validated approach of the most probable fragmentation with input parameters provided by a recent systematic and fission chance probabilities based on nuclear reaction calculations performed with the EMPIRE code

    A unified understanding of (γ, n) and (n, γ) reactions and direct neutron-multiplicity sorting

    Full text link
    We discuss the γ-ray strength function toward a unified understanding of (γ,n) and (n,γ) reactions and propose a novel technique of direct neutron-multiplicity sorting to resolve the long-standing discrepancy between the Livermore and Scalya data of partial photoneutron cross sections.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

    E3 and M2 transition strengths in Bi 83209

    Full text link
    The 1i132›1h92(M2) and 3s12›2f72(E3) reduced proton transition probabilities in Bi83209 have been determined from the direct half-life measurements of the 1321+ and 121+ states using the Romanian array for ?-ray SPectroscopy in HEavy ion REactions (RoSPHERE). The 1321+ and 121+ states were found to have T12=0.120(15) ns and T12=9.02(24) ns respectively. Angular distribution measurements were used to determine an E3/M2 mixing ratio of ?=-0.184(13) for the 1609 keV ?-ray transition deexciting the 1321+ state. This value for ? was combined with the measured half-life to give reduced transition probabilities of B(E3,1321+›921-)=12(2)×103e2fm6 and B(M2,1321+›921-)=38(5)µN2fm2. These values are in good agreement with calculations within the finite Fermi system. The extracted value of B(E3,121+›721-)=6.3(2)×103e2fm6 can be explained by a small (~6%) admixture in the wave function of the 121+ state. © 2016 American Physical Society.Science Foundation Ireland National Science Foundation Science and Technology Facilities CouncilThe staff of the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest, Romania are thanked for their excellent technical support during this experiment. This work was supported by a UK NuSTAR grant (ST/G000697/1) from the Science and Technology Facilities Council (STFC) and by NSF Grant No. PHY-1404442. O.J.R. acknowledges support from Science Foundation Ireland under Grant No. 12/IP/1288. T.A. acknowledges support from Almajmaah University, Saudi Arabia. The work of N.M.F. has been funded by the Sectoral Operational Programme Human Resources Development 2007-2013 of the Ministry of European Funds through the Financial Agreement POSDRU/159/1.5/S/132397. P.H.R. acknowledges support from the UK National Measurement Office (NMO)

    Photoneutron reactions in nuclear astrophysics

    Full text link
    Highly-monochromatic γ-ray beams are produced at the NewSUBARU synchrotron radiation facility by the inverse Compton scattering of laser photons from relativistic electrons. The latest s-process study in nuclear astrophysics with the γ-ray beam is presented.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

    Photoneutron cross section measurements on Sm isotopes

    Full text link
    The Extreme Light Infrastructure - Nuclear Physics, one of the three pillars of the Extreme Light Infrastructure Pan-European initiative, is a new large scale facility dedicated to nuclear physics with extreme electromagnetic fields. ELI-NP will host two 10 PW lasers and a very brilliant Gamma beam system with unprecedented intensity and energy resolution parameters. We propose to perform photon induced nuclear reactions using the very brilliant γ-ray beams provided by the Gamma beam system to examine in detail the photon absorption process and its decay modes. Here the experimental program related to nuclear research on reactions above the neutron separation threshold, which is under preparation at ELI-NP, is presented.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

    γ-ray strength function for thallium isotopes relevant to the 205Pb−205Tl chronometry

    Full text link
    Photoneutron cross sections were measured for 203Tl and 205Tl at energies between the one- and two-neutron thresholds using quasimonochromatic γ -ray beams produced in laser Compton scattering at the NewSUBARU synchrotron radiation facility. Our measurement results in cross sections significantly different from the previously reported bremsstrahlung experiment, leading to rather different giant dipole resonance (GDR) parameters, in particular to lower GDR peak energies and higher peak cross sections. The photoneutron data are used to constrain the γ -ray strength function on the basis of the Hartree-Fock-Bogolyubov plus quasiparticle random-phase approximation using the Gogny D1M interaction. Supplementing the experimentally constrained γ -ray strength function with the zero-limit E1 and M1 contributions for the de-excitation mode, we estimate the Maxwellian-averaged cross section for the s-process branching-point nucleus 204Tl in the context of the 205Pb-205Tl chronometry
    corecore