High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19

Background. This study’s primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods. This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray’s method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results. Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8–11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7–21.0) and 9.3 (95% CI, 7.9–11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018–3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions. In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections

Neutron transport in anisotropic random media

TRIPOLI-4® is a registered trademark of CEA.International audienceAssessing the impact of random media for eigenvalue problems plays a centralrole in nuclear reactor physics and criticality safety. In a recent work (Larmieret al., 2018a), we have applied a probabilistic model based on stochastic tessellationsin order to describe fuel degradation following severe accidents withpartial melting and re-arrangement of the resulting debris. The distribution ofthe multiplication factor and of the kinetics parameters as a function of the mixingstatistics model and of the typical correlation length of the tessellation wereexamined in detail for a benchmark configuration consisting in a fuel assemblywith UOX or MOX fuel pins. In this paper, we extend our previous findingsby including in the stochastic tessellation model the effects of anisotropy thatmight result from gravity and material stratification for this purpose, we adoptthe broad class of anisotropic Poisson geometries. We examine the evolution ofthe statistical properties of the tessellations, including the volume, surface andchord length of the cells for various anisotropy laws, and compare them to thecase of isotropic Poisson geometries. Then, we discuss the behaviour of the keyobservables of interest for eigenvalue problems in anisotropic tessellations byrevisiting the fuel assembly benchmark calculations proposed in (Larmier et al.,2018a). The effects of anisotropic random media on the multiplication factor andon the kinetics parameters will be carefully examined

Optimisation of an hvac system for energy saving and thermal comfort in a university classroom

In university classrooms with air conditioning systems, as well as in conference rooms, thermo-hygrometric and air quality requests must deal with high energy consumption of the plant system. The whole plant management is sometimes critical due to the particular conditions of use of the rooms where the ventilation rate demand and thermal loads may change consistently during daily occupation. In this work an existing HVAC system unit is analyzed, serving two classrooms with a single zone distribution. The HVAC system is set to work with an external air supply at a constant rate, and includes air treatment sections with heating, cooling and vapour humidification. Experimental measurements of both thermal comfort parameters and real operating conditions of the HVAC unit gave information about critical aspects of the whole building-plant system design and management. In this work an energy dynamic simulation of the building-plant system using Energy-Plus software has been realized. After a proper calibration of the model based on experimental measurements, a dynamic simulation is used to carry out plant management strategies (e.g. free cooling, variable set points for intermediate occupational condition, mixing of the external air with recycled air, etc.) that combine energy savings with better indoor comfort. Several design alternatives are modelled through Energy-Plus to predict energy performance improvements associated with a different set of HVAC system configuration. Simulation results indicate up to 60% energy savings

Chord length distribution in dd-dimensional anisotropic Markov media

International audienceMarkov media are often used as a prototype model in the analysis of linear particle transport in disordered materials. For this class of stochastic geometries, it is assumed that the chord lengths must follow an exponential distribution, with a direction-dependent average if anisotropy effects are to be taken into account. The practical realizability of Markov media in arbitrary dimension has been a long-standing open question. In this work we show that Poisson hyperplane tessellations provide an explicit construction for random media satisfying the Markov property and easily including anisotropy. The average chord length can be computed explicitly and is be shown to be intimately related to the statistical properties of the tessellation cells and in particular to their surface-to-volume ratio. A computer code that is able to generate anisotropic Poisson tessellations in arbitrary dimension restricted to a given finite domain is developed, and the convergence to exact asymptotic formulas for the chord length distribution and the polyhedral features of the tessellation cells is established by extensive Monte Carlo simulations in the limit of domains having an infinite size

Indagini sulle condizioni di comfort all'interno di aule scolastiche climatizzate: presentazione di un caso studio

L\u2019articolo presenta alcuni risultati di una serie di indagini sperimentali sulle condi-zioni termo-igrometriche e di qualit\ue0 dell\u2019aria eseguite all\u2019interno di due aule universita-rie adiacenti, servite da un\u2019unica unit\ue0 di trattamento aria (con regolazione del tipo mo-nozona) alla quale compete sia la gestione dei ricambi d\u2019aria che la climatizzazione in-vernale ed estiva. Le prove sperimentali sono state affiancate da questionari compilati dagli studenti volti a fornire un giudizio soggettivo che \ue8 stato confrontato con gli indici di comfort utilizzati dalle norme nazionali e dedotti dalla teoria di Fanger. Le diverse ti-pologie di analisi hanno consentito di individuare le criticit\ue0 legate alla tipologia di im-pianto ed alla sua gestione che, oltre ad aspetti legati al comfort, hanno anche forti im-plicazione sui consumi energetici. Ulteriori considerazioni sulla \u201cadattabilit\ue0\u201d degli stu-denti a valori di set-point diversi da quelli di progetto, consentono di ipotizzare soluzioni diversificate di gestione degli impianti

La distribuzione territoriale del consumo di suolo

Analisi della distribuzione territoriale del consumo di suol