Simulation haute-fidélité et optimisation des pratiques professionnelles. De l'échelon individuel à l'échelle du pôle hospitalier

International audienc

THE EUROPEAN MOZAIC PROGRAM: Measurements of Ozone and H2O aboard Airbus ins-service aircraft -1994-2003. Additional measurements of carbon monoxide and NOy since 2001

(septembre)

Carbon monoxide measurements aboaard commercial airbus aircraft : technical validation and first scientific results of the MOZAIC III programme.

(06-11 avril 2003)

Magic Number Pt₁₃ and Misshapen Pt₁₂ Clusters: Which One is the Better Catalyst?

A relationship between the size of metal particles and their catalytic activity has been established over a nanometer scale (2–10 nm). However, application on a subnanometer scale (0.5–2 nm) is difficult, a possible reason being that the activity no longer relies on the size but rather the geometric structure as a cluster (or superatomic) compound. We now report that the catalytic activity for the oxygen reduction reaction (ORR) significantly increased when only one atom was removed from a magic number cluster composed of 13-platinum atoms (Pt₁₃). The synthesis with an atomic-level precision was successfully achieved by using a dendrimer ligand as the macromolecular template strictly defining the number of metal atoms. It was quite surprising that the Pt₁₂ cluster exhibited more than 2-fold catalytic activity compared with that of the Pt₁₃ cluster. ESI-TOF-mass and EXAFS analyses provided information about the structures. These analyses suggested that the Pt₁₂ has a deformed coordination, while the Pt₁₃ has a well-known icosahedral atomic coordination as part of the stable cluster series. Theoretical analyses based on density functional theory (DFT) also supported this idea. The present results suggest potential activity of the metastable clusters although they have been “missing” species in conventional statistical synthesis

Impact de la mise en place d'un réseau de soins en traumatologie sur la mortalité des patients traumatisés graves du bassin [Impact of a trauma network on mortality in patients with severe pelvic trauma]

To evaluate the impact of a regional trauma network on intra-hospital mortality rates of patients admitted with severe pelvic trauma. Retrospective observational study. Sixty-five trauma patients with serious pelvic fracture (pelvic abbreviated injury scale [AIS] score of 3 or more). Demographic, physiologic and biological parameters were recorded. Observed mortality rates were compared to predicted mortality according to the Trauma Revised Injury Severity Score methodology adjusted by a case mix variation model. Twenty-nine patients were admitted in a level I trauma centre (reference centre) and 36 in level II trauma centres (centres with interventional radiology facility and/or neurosurgery). Patients from the level I trauma centre were more severely injured than those who were admitted at the level II trauma centres (Injury Severity Score [ISS]: 30 [13-75] vs 22 [9-59]; P<0.01). Time from trauma to hospital admission was also longer in level I trauma centre (115 [50-290] min vs 90 [28-240] min, P <0.01). Observed mortality rates (14%; 95% confidence interval, 95% CI, [1-26%]) were lower than the predicted mortality (29%; 95% CI [13-44%]) in the level I trauma centre. No difference in mortality rates was found in the level II trauma centres. The regional trauma network could screen the most severely injured patients with pelvic trauma to admit them at a level I trauma centre. The observed mortality of these patients was lower than the predicted mortality despite increased time from trauma to admission

Observations of ozone transport from the free troposphere to the Los Angeles basin

Analysis of in situ airborne measurements from the CalNex 2010 field experiment (Research at the Nexus of Air Quality and Climate Change) show that ozone in the boundary layer over Southern California was increased by downward mixing of air from the free troposphere (FT). The chemical composition, origin, and transport of air upwind and over Los Angeles, California, were studied using measurements of carbon monoxide (CO), ozone, reactive nitrogen species, and meteorological parameters from the National Oceanic and Atmospheric Administration WP-3D aircraft on 18 research flights in California in May and June 2010. On six flights, multiple vertical profiles from 0.2-3.5 km above ground level were conducted throughout the Los Angeles (LA) basin and over the Pacific Ocean. Gas phase compounds measured in 32 vertical profiles are used to characterize air masses in the FT over the LA basin, with the aim of determining the source of increased ozone observed above the planetary boundary layer (PBL). Four primary air mass influences were observed regularly in the FT between approximately 1 and 3.5 km altitude: upper tropospheric air, long-range transport of emissions, aged regional emissions, and marine air. The first three air mass types accounted for 89% of the FT observations. Ozone averaged 71 ppbv in air influenced by the upper troposphere, 69 ppbv in air containing emissions transported long distances, and 65 ppbv in air with aged regional emissions. Correlations between ozone and CO, and ozone and nitric acid, demonstrate entrainment of ozone from the FT into the LA PBL. Downward transport of ozone-rich air from the FT into the PBL contributes to the ozone burden at the surface in this region and makes compliance with air quality standards challenging

A relação entre o social e o natural nas abordagens de hazards e de desastres The relation between the social and the natural in the approach of hazards and disasters

O artigo aborda as teorias dos Hazards e dos Desastres. Nos últimos anos estas duas tradições teóricas têm recebido novos impulsos pela renovação de seus marcos de referência conceitual. Construídas em torno de uma longa tradição de pesquisa empírica, estas teorias explicam os impactos provocados por fenômenos como enchentes, terremotos, tornados e epidemias mediante a integração analítica das dimensões natural e social. Neste sentido, seu estudo pode fornecer subsídios para a interpretação destes problemas no Brasil.<br>The article deals with the theory of hazards and disasters. Over the past years, these two theoretical traditions have received new impulse through the renovation of their conceptual foundations. Constructed around a long tradition of empirical research, these theories explain the impacts brought by phenomena like floods, earthquakes, tornadoes and epidemics through the analytical integration of social and natural dimensions. In this regard, its study may provide grants in order to interpret these problems in Brazil