11 research outputs found

    Laser generated electron transport experiment in a novel wire nail target

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    The transport of high intensity (2x1020 W/cm2) laser generated relativistic electrons with a solid target has been studied in a novel geometry. The targets were 20 um diameter solid copper wires, coated with ~ 2um of titanium, with an 80 um diameter hemispherical termination. They were illuminated by an ~500fs, ~200J pulse of 1.053um laser light focused to a ~ 20um diameter spot centered on the flat face of the hemisphere. K-alpha fluorescence from the Cu and Ti regions was imaged together with extreme ultraviolet (X-UV) emission at 68 and 256eV. Results showed a quasi exponential decline in K-alpha emission along the wire over a distance of a few hundred microns from the laser focus, consistent with bulk Ohmic inhibition of the relativistic electron transport. Weaker Ka and X-UV emission on a longer scale length showed limb brightening suggesting a transition to enhanced transport at the surface of the wire

    Energy Injection for Fast Ignition

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    In the fast ignition concept, assembled fuel is ignited through a separate high intensity laser pulse. Fast Ignition targets facilitate this ignition using a reentrant cone. It provides clear access through the overlaying coronal plasma, and controls the laser plasma interaction to optimize hot-electron production and transport into the compressed plasma. Recent results suggest that the cone does not play any role in guiding light or electrons to its tip, and coupling to electrons can be reduced by a small amount of preplasma. This puts stringent requirements on the ignition laser focusing, pointing, and prepulse

    Attributable Mortality of Ventilator-associated Pneumonia Among Patients with COVID-19

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    International audienceRationale: Patients with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are at higher risk of ventilator-associated pneumonia (VAP) and may have an increased attributable mortality (increased or decreased risk of death if VAP occurs in a patient) and attributable fraction (proportion of deaths that are attributable to an exposure) of VAP-related mortality compared with subjects without coronavirus disease (COVID-19). Objectives: Estimation of the attributable mortality of the VAP among patients with COVID-19. Methods: Using the REA-REZO surveillance network, three groups of adult medical ICU patients were computed: control group (patients admitted between 2016 and 2019; prepandemic patients), pandemic COVID-19 group (PandeCOV+), and pandemic non-COVID-19 group (PandeCOV-) admitted during 2020. The primary outcome was the estimation of attributable mortality and attributable fraction related to VAP in these patients. Using multistate modeling with causal inference, the outcomes related to VAP were also evaluated. Measurements and Main Results: A total of 64,816 patients were included in the control group, 7,442 in the PandeCOV- group, and 1,687 in the PandeCOV+ group. The incidence of VAP was 14.2 (95% confidence interval [CI], 13.9 to 14.6), 18.3 (95% CI, 17.3 to 19.4), and 31.9 (95% CI, 29.8 to 34.2) per 1,000 ventilation-days in each group, respectively. Attributable mortality at 90 days was 3.15% (95%, CI, 2.04% to 3.43%), 2.91% (95% CI, -0.21% to 5.02%), and 8.13% (95% CI, 3.54% to 12.24%), and attributable fraction of mortality at 90 days was 1.22% (95% CI, 0.83 to 1.63), 1.42% (95% CI, -0.11% to 2.61%), and 9.17% (95% CI, 3.54% to 12.24%) for the control, PandeCOV-, and PandeCOV+ groups, respectively. Except for the higher risk of developing VAP, the PandeCOV- group shared similar VAP characteristics with the control group. PandeCOV+ patients were at lower risk of death without VAP (hazard ratio, 0.62; 95% CI, 0.52 to 0.74) than the control group. Conclusions: VAP-attributable mortality was higher for patients with COVID-19, with more than 9% of the overall mortality related to VAP

    Attributable Mortality of Ventilator-associated Pneumonia Among Patients with COVID-19

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    International audienceRationale: Patients with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are at higher risk of ventilator-associated pneumonia (VAP) and may have an increased attributable mortality (increased or decreased risk of death if VAP occurs in a patient) and attributable fraction (proportion of deaths that are attributable to an exposure) of VAP-related mortality compared with subjects without coronavirus disease (COVID-19). Objectives: Estimation of the attributable mortality of the VAP among patients with COVID-19. Methods: Using the REA-REZO surveillance network, three groups of adult medical ICU patients were computed: control group (patients admitted between 2016 and 2019; prepandemic patients), pandemic COVID-19 group (PandeCOV+), and pandemic non-COVID-19 group (PandeCOV-) admitted during 2020. The primary outcome was the estimation of attributable mortality and attributable fraction related to VAP in these patients. Using multistate modeling with causal inference, the outcomes related to VAP were also evaluated. Measurements and Main Results: A total of 64,816 patients were included in the control group, 7,442 in the PandeCOV- group, and 1,687 in the PandeCOV+ group. The incidence of VAP was 14.2 (95% confidence interval [CI], 13.9 to 14.6), 18.3 (95% CI, 17.3 to 19.4), and 31.9 (95% CI, 29.8 to 34.2) per 1,000 ventilation-days in each group, respectively. Attributable mortality at 90 days was 3.15% (95%, CI, 2.04% to 3.43%), 2.91% (95% CI, -0.21% to 5.02%), and 8.13% (95% CI, 3.54% to 12.24%), and attributable fraction of mortality at 90 days was 1.22% (95% CI, 0.83 to 1.63), 1.42% (95% CI, -0.11% to 2.61%), and 9.17% (95% CI, 3.54% to 12.24%) for the control, PandeCOV-, and PandeCOV+ groups, respectively. Except for the higher risk of developing VAP, the PandeCOV- group shared similar VAP characteristics with the control group. PandeCOV+ patients were at lower risk of death without VAP (hazard ratio, 0.62; 95% CI, 0.52 to 0.74) than the control group. Conclusions: VAP-attributable mortality was higher for patients with COVID-19, with more than 9% of the overall mortality related to VAP

    Attributable Mortality of Ventilator-associated Pneumonia Among Patients with COVID-19

    No full text
    International audienceRationale: Patients with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are at higher risk of ventilator-associated pneumonia (VAP) and may have an increased attributable mortality (increased or decreased risk of death if VAP occurs in a patient) and attributable fraction (proportion of deaths that are attributable to an exposure) of VAP-related mortality compared with subjects without coronavirus disease (COVID-19). Objectives: Estimation of the attributable mortality of the VAP among patients with COVID-19. Methods: Using the REA-REZO surveillance network, three groups of adult medical ICU patients were computed: control group (patients admitted between 2016 and 2019; prepandemic patients), pandemic COVID-19 group (PandeCOV+), and pandemic non-COVID-19 group (PandeCOV-) admitted during 2020. The primary outcome was the estimation of attributable mortality and attributable fraction related to VAP in these patients. Using multistate modeling with causal inference, the outcomes related to VAP were also evaluated. Measurements and Main Results: A total of 64,816 patients were included in the control group, 7,442 in the PandeCOV- group, and 1,687 in the PandeCOV+ group. The incidence of VAP was 14.2 (95% confidence interval [CI], 13.9 to 14.6), 18.3 (95% CI, 17.3 to 19.4), and 31.9 (95% CI, 29.8 to 34.2) per 1,000 ventilation-days in each group, respectively. Attributable mortality at 90 days was 3.15% (95%, CI, 2.04% to 3.43%), 2.91% (95% CI, -0.21% to 5.02%), and 8.13% (95% CI, 3.54% to 12.24%), and attributable fraction of mortality at 90 days was 1.22% (95% CI, 0.83 to 1.63), 1.42% (95% CI, -0.11% to 2.61%), and 9.17% (95% CI, 3.54% to 12.24%) for the control, PandeCOV-, and PandeCOV+ groups, respectively. Except for the higher risk of developing VAP, the PandeCOV- group shared similar VAP characteristics with the control group. PandeCOV+ patients were at lower risk of death without VAP (hazard ratio, 0.62; 95% CI, 0.52 to 0.74) than the control group. Conclusions: VAP-attributable mortality was higher for patients with COVID-19, with more than 9% of the overall mortality related to VAP

    Equation of state of CH1.36: first-principles molecular dynamics simulations and shock-and-release wave speed measurements

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    We report the computation and measurement of the equation of state of a plastic with composition CH1.36. The computational scheme employed is density functional theory based molecular dynamics, at the conditions: 1.8 g/cm3 <ρ<10 g/cm3, and 4000 K <T< 100 000 K. Experimental measurements are of the shock speeds in a geometry in which the plastic is directly abutting a different material, liquid deuterium, from which release wave behavior in the plastic can be deduced. After fitting our computed pressure and internal energy with a Mie-Grüneisen free energy model, we predict the principal shock Hugoniot and various shock-and-release paths and show that they agree with both recently published laser-shock data and our new data regarding the shock speeds on release. We also establish that, at least in the particular (ρ,T) range considered, the equation of state of this complex two-component material is well described by an equal pressure and temperature mixture of pure C and H equations of state with a composition-weighted additive-volume assumption. This observation, together with our fit to the limited-range simulation data, can form the basis for the construction of an accurate wide-range equation of state model for this plastic. Implications for its use as an ablator in inertial confinement fusion capsules are discussed

    Safety, efficacy, and pharmacokinetics of gremubamab (MEDI3902), an anti-Pseudomonas aeruginosa bispecific human monoclonal antibody, in P. aeruginosa-colonised, mechanically ventilated intensive care unit patients : a randomised controlled trial

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    Background: Ventilator-associated pneumonia caused by Pseudomonas aeruginosa (PA) in hospitalised patients is associated with high mortality. The effectiveness of the bivalent, bispecific mAb MEDI3902 (gremubamab) in preventing PA nosocomial pneumonia was assessed in PA-colonised mechanically ventilated subjects. Methods: EVADE (NCT02696902) was a phase 2, randomised, parallel-group, double-blind, placebo-controlled study in Europe, Turkey, Israel, and the USA. Subjects ≥ 18 years old, mechanically ventilated, tracheally colonised with PA, and without new-onset pneumonia, were randomised (1:1:1) to MEDI3902 500, 1500 mg (single intravenous dose), or placebo. The primary efficacy endpoint was the incidence of nosocomial PA pneumonia through 21 days post-dose in MEDI3902 1500 mg versus placebo, determined by an independent adjudication committee. Results: Even if the initial sample size was not reached because of low recruitment, 188 subjects were randomised (MEDI3902 500/1500 mg: n = 16/87; placebo: n = 85) between 13 April 2016 and 17 October 2019. Out of these, 184 were dosed (MEDI3902 500/1500 mg: n = 16/85; placebo: n = 83), comprising the modified intent-to-treat set. Enrolment in the 500 mg arm was discontinued due to pharmacokinetic data demonstrating low MEDI3902 serum concentrations. Subsequently, enrolled subjects were randomised (1:1) to MEDI3902 1500 mg or placebo. PA pneumonia was confirmed in 22.4% (n = 19/85) of MEDI3902 1500 mg recipients and in 18.1% (n = 15/83) of placebo recipients (relative risk reduction [RRR]: − 23.7%; 80% confidence interval [CI] − 83.8%, 16.8%; p = 0.49). At 21 days post-1500 mg dose, the mean (standard deviation) serum MEDI3902 concentration was 9.46 (7.91) μg/mL, with 80.6% (n = 58/72) subjects achieving concentration
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