Immunocompromised hosts, which encompass a diverse population of persons with malignancies, human immunodeficiency virus disease, solid organ, and hematologic transplants, autoimmune diseases, and ...primary immunodeficiencies, bear a significant burden of the morbidity and mortality due to coronavirus disease-2019 (COVID-19). Immunocompromised patients who develop COVID-19 have a more severe illness, higher hospitalization rates, and higher mortality rates than immunocompetent patients. There are no well-defined treatment strategies that are specific to immunocompromised patients and vaccines, monoclonal antibodies, and convalescent plasma are variably effective. This review focuses on the specific impact of COVID-19 in immunocompromised patients and the gaps in knowledge that require further study.
Immunocompromised hosts, which encompass a diverse population of persons with malignancies, human immunodeficiency virus disease, solid organ, and hematologic transplants, autoimmune diseases, and ...primary immunodeficiencies, bear a significant burden of the morbidity and mortality due to coronavirus disease-2019 (COVID-19). Immunocompromised patients who develop COVID-19 have a more severe illness, higher hospitalization rates, and higher mortality rates than immunocompetent patients. There are no well-defined treatment strategies that are specific to immunocompromised patients and vaccines, monoclonal antibodies, and convalescent plasma are variably effective. This review focuses on the specific impact of COVID-19 in immunocompromised patients and the gaps in knowledge that require further study.
The paper presents a numerical study where a hybrid CFD-Chemical Reactor Network (CRN) approach is used to predict pollutant emissions in a tubular combustor for aero-engine applications. A ...fully-automated clustering of the simulated flow field with the generation of a reactor network representative of the main flow features is exploited. Similar cells are detected and grouped using a two step approach, the first one based only on aerodynamic criteria for turbulent flows followed by a chemical refinement based on mixture fraction. A formulation for turbulent diffusion fluxes is introduced in the reactor code to model species and energy exchanges between reactors. Three different operating conditions are studied for which measured NOx and CO are available. Results highlight the importance of including turbulent diffusion in the network solution. The accurate prediction of pollutant emissions at different load points confirms that CFD-CRN is a valid and flexible approach for preliminary assessment of aero-engine combustor emissions in the design phase.
The evolution of dense plasmas prior to the arrival of the peak of the laser irradiation is critical to understanding relativistic laser plasma interactions. The spectral properties of a reflected ...laser pulse after the interaction with a plasma can be used to gain insights about the interaction itself, whereas the effect of holeboring has a predominant role. Here we developed an analytical model, describing the non-relativistic temporal evolution of the holeboring velocity in the presence of an arbitrary overdense plasma density and laser intensity profile. We verify this using two-dimensional particle-in-cell simulations, showing a major influence on the holeboring dynamic depending on the density profile. The influence on the reflected laser pulse has been verified during an experiment at the PHELIX laser. We show that this enables the possibility to determine the sub-micrometer scale length of the preplasma by measuring the maximum holeboring velocity and acceleration during the laser-plasma interaction.
In this work, we present the results of an experiment aiming at proton acceleration using a focus with a homogeneous intensity distribution, called smoothed focus. To achieve this goal, we ...implemented a phase plate before the pre-amplifier of the Petawatt High-Energy Laser for Heavy Ion EXperiments laser facility. The phase plate was used for the first time at a high-power short-pulse laser. Demonstrating a low divergent ion beam was the main goal of this work. Numerical simulations using the particle-in-cell code Extendable PIC Open Collaboration estimated a 2–5 times reduction in the angular divergence of the proton beam using a phase plate due to a smoother sheath at the rear side of the target. However, the reduction in the angular divergence was not sensible according to the experimental data. A positive point is that the spectrum of protons that are generated with the smoothed beam is shifted toward lower energies, provided that the laser absorption is kept in check, compared to the Gaussian proton spectrum. Moreover, the number of protons that are generated with the smoothed beam is higher than the ones generated with the Gaussian beam.
The FairRoot framework Al-Turany, M; Bertini, D; Karabowicz, R ...
Journal of physics. Conference series,
01/2012, Letnik:
396, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The FairRoot framework is an object oriented simulation, reconstruction and data analysis framework based on ROOT. It includes core services for detector simulation and offline analysis. The ...framework delivers base classes which enable the users to easily construct their experimental setup in a fast and convenient way. By using the Virtual Monte Carlo concept it is possible to perform the simulations using either Geant3 or Geant4 without changing the user code or the geometry description. Using and extending the task mechanism of ROOT it is possible to implement complex analysis tasks in a convenient way. Moreover, using the FairCuda interface of the framework it is possible to run some of these tasks also on GPU. Data IO, as well as parameter handling and data base connections are also handled by the framework. Since some of the experiments will not have an experimental setup with a conventional trigger system, the framework can handle also free flowing input streams of detector data. For this mode of operation the framework provides classes to create the needed time sorted input streams of detector data out of the event based simulation data. There are also tools to do radiation studies and to visualize the simulated data. A CMake-CDash based building and monitoring system is also part of the FairRoot services which helps to build and test the framework on many different platforms in an automatic way, including also Continuous Integration.
This paper presents a set of numerical analyses carried out on a model combustor equipped with a prefilming airblast injection system using a multi-coupled approach that includes the solution of the ...liquid film over the prefilming surface. The main objective of this study is to perform a systematic investigation of all the relevant aspects involved in the liquid fuel preparation of airblast atomizers, ranging from the interaction between the gas phase and the liquid film to the effect of velocity fluctuations on the dispersion of droplets downstream of the injector exit. Measurements at high pressure and reacting conditions are available for the case considered here, therefore, allowing to perform such investigation at engine-relevant conditions. The solution of the liquid film evolution over the prefilming surface suggests that the interaction between the gas phase and the liquid film is an important aspect to be considered for a reliable simulation of prefilming airblast systems since it has a strong impact on both velocity and fuel temperature at the atomizing edge. The role of primary breakup has been investigated by performing a sensitivity analysis to different theoretical and correlation-based models. Results obtained from this analysis, performed using Reynolds averaged Navier-Stokes simulations, show that the various formulations predict a quite different diameter, affecting the mixing field in the downstream region and therefore pointing out the necessity of more advanced and robust formulations. A comparison between experimental measurements and a scale-adaptive simulation of the combustor, performed using the spray setup determined in the sensitivity analysis, demonstrates the necessity of including in the simulation time-resolved velocity fluctuations to improve the prediction of the dispersion of droplets and therefore give a reliable prediction of fuel location and mixing.
In order to meet the increasingly stringent regulations in terms of pollutant emissions adopted by ICAO-CAEP in last years, a redesign of aero-engine combustors has been required and, today, lean ...combustion technology can be considered as the most effective solution. In this context, common design tools and standard RANS predictive techniques are often not capable of properly characterizing combustors performances. Thus, computational techniques have been rapidly evolving towards an extensive use of Large-Eddy Simulation (LES) or hybrid RANS methods. This paper presents the numerical analysis of an experimental partially premixed flame fed by a dilute spray of acetone1, exploiting a two-phase Eulerian-Lagrangian approach combined with the Flamelet Generated Manifold (FGM) combustion model in the context of LES techniques. All simulations have been performed with thecode Ansys Fluent 15.0.
A comparison both in non-reactive and reactive conditions of the obtained results with experimental data and conventional RANS solution has been realized in order to highlight the LES capabilities to give a new insight into the physics of reactive two-phase flows, particularly on the unsteady evolution of turbulent spray flames involving particles dispersion, evaporation and combustion.
Severe factor V (FV) deficiency (parahaemophilia) is a rare congenital hemorrhagic disorder characterized by very low or undetectable plasma FV levels and bleeding phenotype ranging from mild to ...severe. We evaluated whole blood (WB) rotation thromboelastometry (ROTEM) in parahaemophilia patients and the contribution of intraplatelets FV, if any, to clot formation. Standard ROTEM® assays were performed in WB from nine parahaemophilia patients and 50 healthy controls. In addition, platelets poor plasma from one parahaemophilia patient (PPP‐Pt) or normal subjects (PPP‐N) was reconstituted with washed platelets obtained either from one patient with parahaemophilia (Plts‐Pt) or normal subjects (Plts‐N) and ROTEM assays were performed in platelets rich plasma (PRP) samples. There was a prolongation of the WB clotting time (CT) in all assays in patients as compared with controls. However, maximum clot firmness (MCF) was similar in patients and controls. ROTEM in PPP‐Pt showed both a prolongation of CT and a reduction of MCF as compared with PPP‐N. The addition of either Plts‐Pt or Plts‐N to PPP‐Pt resulted in similar increase in MCF and a decrease of CT which was more evident for PPP‐Pt + Plts‐N than PPP‐Pt + Plts‐Pt. In contrast, the addition of Plts‐Pt or Plts‐N to PPP‐N had superimposable effects on both CT and MCF. In parahaemophilia patients, WB ROTEM® presents mainly with prolongation of CT and no relevant effect on MCF. Residual intraplatelets FV in parahaemophilia contributes significantly to thrombin generation as shown in artificially reconstituted PRP models.
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