39 research outputs found

    Epinephrine and short-term survival in cardiogenic shock : an individual data meta-analysis of 2583 patients

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    Correction Volume: 44 Issue: 11 Pages: 2022-2023 DOI: 10.1007/s00134-018-5372-9Catecholamines have been the mainstay of pharmacological treatment of cardiogenic shock (CS). Recently, use of epinephrine has been associated with detrimental outcomes. In the present study we aimed to evaluate the association between epinephrine use and short-term mortality in all-cause CS patients. We performed a meta-analysis of individual data with prespecified inclusion criteria: (1) patients in non-surgical CS treated with inotropes and/or vasopressors and (2) at least 15% of patients treated with epinephrine administrated alone or in association with other inotropes/vasopressors. The primary outcome was short-term mortality. Fourteen published cohorts and two unpublished data sets were included. We studied 2583 patients. Across all cohorts of patients, the incidence of epinephrine use was 37% (17-76%) and short-term mortality rate was 49% (21-69%). A positive correlation was found between percentages of epinephrine use and short-term mortality in the CS cohort. The risk of death was higher in epinephrine-treated CS patients (OR [CI] = 3.3 [2.8-3.9]) compared to patients treated with other drug regimens. Adjusted mortality risk remained striking in epinephrine-treated patients (n = 1227) (adjusted OR = 4.7 [3.4-6.4]). After propensity score matching, two sets of 338 matched patients were identified and epinephrine use remained associated with a strong detrimental impact on short-term mortality (OR = 4.2 [3.0-6.0]). In this very large cohort, epinephrine use for hemodynamic management of CS patients is associated with a threefold increase of risk of death.Peer reviewe

    Electron and ion elastic scattering modeling in Geant4-DNA

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    The general purpose Monte Carlo simulation toolkit Geant4 is currently being extended for the simulation of biological effects of ionizing radiation at the cellular and DNA scales, in the framework of the Geant4-DNA project, an activity of the Geant4 collaboration which was initiated by the European Space Agency for the prediction of direct and non-direct radiobiological damages in long duration manned space exploration missions [1]. A complete set of physics processes is already available to Geant4 users for the modeling of the physical interactions of electrons, protons, neutral hydrogen atoms and alpha particles including their charged states in liquid water, the main component of biological medium [2]

    Energy deposition in small-scale targets of liquid water using the very low energy electromagnetic physics processes of the Geant4 toolkit

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    In the perspective of building an open source simulation platform dedicated to the modelling of early biological molecular damages due to ionising radiation at the DNA scale, the general-purpose Geant4 Monte Carlo simulation toolkit has been recently extended with specific very low energy electromagnetic physics processes for liquid water medium. These processes - also called ''Geant4-DNA'' processes - simulate the physical interactions induced by electrons, hydrogen and helium atoms of different charge states. The present work reports on the energy deposit distributions obtained for incident electrons, protons and alpha particles in nanometre-size volumes comparable to those present in the genetic material of mammalian cells. The frequency distributions of the energy deposition obtained for three typical geometries of nanometre-size cylindrical targets placed in a spherical phantom are found to be in reasonable agreement with prior works. Furthermore, we present a combination of the Geant4-DNA processes with a simplified geometrical model of a cellular nucleus allowing the evaluation of energy deposits in volumes of biological interest

    PIXE simulation in Geant4

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    Geant4 is a general purpose and open source C + + Monte Carlo simulation toolkit, widely used in the scientific community. It is able to simulate physical interactions of particles through matter. According to the user's needs, models for the simulation of electromagnetic (EM) interactions are provided in two Geant4 subpackages, the 'standard' EM subpackage, well suited for a wide range of applications and the 'low-energy' EM subpackage, able to reach the electronVolt regime. Particle-induced X-ray emission (PIXE) is a well known and a very useful technique for quantitative elemental analysis in environmental, archaeological, biological, medical and space applications. An atomic de-excitation module is part of the Geant4 'low-energy' EM subpackage since 1999 and has been validated in recent years. PIXE simulation has been included in this subpackage in 2001 and new ionisation cross-sectional models following the ECPSSR theory have been added for the PIXE simulation in 2008. In 2010, these models have been further extended to higher energies. In this work, we present new results on the verification of these models and an overview of the new interface to PIXE modelling prepared for the recent public release of the Geant4 toolkit (December 2010) allowing a unified usage of the Geant4 de-excitation module by both 'standard' and 'low-energy' subpackages. Copyright © 2011 John Wiley & Sons, Ltd

    Modeling Radiation Chemistry in the Geant4 Toolkit

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    Mathieu KARAMITROS , Alfonso MANTERO , Sebastien INCERTI , Werner FRIEDLAND , Gerard BALDACCHINO , Philippe BARBERET , Mario BERNAL , Riccardo CAPRA , Christophe CHAMPION , Ziad EL BITAR , Ziad FRANCIS , Paul GUEYE , Anton IVANCHENKO , Vladimir IVANCHENKO , Hisaya KURASHIGE , Barbara MASCIALINO , Philippe MORETTO , Petteri NIEMINEN , Giovanni SANTIN , Herve SEZNEC , Hoang N. TRAN , Carmen VILLAGRASA 9 and Christina ZACHARATOU 1

    Dose point kernels in liquid water: An intra-comparison between GEANT4-DNA and a variety of Monte Carlo codes

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    Modeling the radio-induced effects in biological medium still requires accurate physics models to describe the interactions induced by all the charged particles present in the irradiated medium in detail. These interactions include inelastic as well as elastic processes. To check the accuracy of the very low energy models recently implemented into the GEANT4 toolkit for modeling the electron slowing-down in liquid water, the simulation of electron dose point kernels remains the preferential test. In this context, we here report normalized radial dose profiles, for mono-energetic point sources, computed in liquid water by using the very low energy "GEANT4-DNA" physics processes available in the GEANT4 toolkit. In the present study, we report an extensive intra-comparison of profiles obtained by a large selection of existing and well-documented Monte-Carlo codes, namely, EGSnrc, PENELOPE, CPA100, FLUKA and MCNPX.Modélisation des dommages à l'ADN induits par les rayonnements ionisants avec l'outil Monte Carlo Geant4 et validation expérimental

    Comparison of Geant4-DNA simulation of S-values with other Monte Carlo codes

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    Monte Carlo simulations of S-values have been carried out with the Geant4-DNA extension of the Geant4 toolkit. The S-values have been simulated for monoenergetic electrons with energies ranging from 0.1 keV up to 20 keV, in liquid water spheres (for four radii, chosen between 10 nm and 1 μm), and for electrons emitted by five isotopes of iodine (131, 132, 133, 134 and 135), in liquid water spheres of varying radius (from 15 μm up to 250 μm). The results have been compared to those obtained from other Monte Carlo codes and from other published data. The use of the Kolmogorov–Smirnov test has allowed confirming the statistical compatibility of all simulation results
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