Validation du GAP Index, un outil prédictif de mortalité dans la fibrose pulmonaire idiopathique

Fibrose pulmonaire idiopathique La fibrose pulmonaire idiopathique (FPI, Idiopathic Pulmonary Fibrosis) est une maladie diffuse du parenchyme pulmonaire de cause inconnue caractérisée par une aggravation de la dyspnée, une réduction du volume pulmonaire et une altération des échanges gazeux. Elle est la plus fréquente de pneumopathies interstitielles idiopathiques (IIPs, Idiopathic Interstitial Pneumonias), avec une incidence annuelle estimée entre 4,6 et 16,3 pour 100'000 personnes et une prévalence de 13 à 20 cas pour 100 000 personnes. Son évolution est progressive, irréversible et de mauvais pronostic avec une survie médiane de 2 à 3.5 ans et une survie à 5 ans de moins de 20%

Heterogeneous catalyzed macromolecular hydrogenations in oscillating systems

An examination of novel oscillatory (alternating gas and liquid phase) reactors and heterogeneous catalysts for multi-phase macromolecular reactions was carried out. A monolith-containing square die with Pd/Al2O3 catalysts was used to successfully hydrogenate poly(styrene) (PS). The inherent pulse behavior of the extruder was found to be sufficient to approach intrinsic kinetics at low polymer concentrations. At higher (10 wt% PS) concentrations, forced pulsing was shown to have a greater impact on observed reaction rates. Selectivity with this extruder-fed reactor was better than with a stirred tank in all cases, due to a more plug-flow-like residence time distribution. While accurate control over the exit distribution of forced pulses was difficult due to gas back mixing, an optimal frequency of forced pulsation was observed for the 10 wt% PS system. Mesoporous catalysts for macromolecular hydrogenations were synthesized and tested for PS hydrogenation. They were shown to be more active than microporous catalysts. The type of support was shown not to have a large influence on activity, but high dispersion of the active metal was critical. The addition of a second inactive metal did improve hydrogenation selectivity, but it was observed that having a chloride-free support is even more important in achieving high activity. For the hydrogenation of a low molecular weight species (α-methylstyrene) (AMS) in a piston oscillating monolith reactor (POMR), oscillations gave improvements in reaction rate of up to 84%. With no oscillations, the activity was still higher than in a stirred tank operated at an equivalent power per unit volume. Selectivity in the POMR was as good as or better than in a stirred tank. It was also found that the Pd crystallite size had a large influence on activity. For the hydrogenation of soybean oil, the POMR gave a higher activity than a stirred tank at identical conditions. The hydrogenation rate increased by as much as 112% with oscillations. It was shown that this improvement was unrelated to external mass transfer; rather it arised from improved intraparticle mass transfer limitations or surface wetting. Sereo-selectivity was largely unaffected by the reactor system but was instead dependent on intraparticle diffusion lengths

How Can Outreach Foster Further Interest in Stem and Eventually Lead to Careers in STEM?

Numerous universities, colleges, and STEM-focused organizations co-create outreach activities with secondary education institutions by connecting the work-context with school-science, with the aim to inspire students and motivate them to consider a career in STEM. Although many such activities are being offered, little is known about their actual influence and outcomes. In this article, I approach the experts from STEM outreach field, with backgrounds ranging from not-for-profit science centers, through industry, research institutes, and universities, will address their approach to measuring what impact their STEM outreach programs had on program participants. At the same time, they will address what role equity, diversity and inclusion plays in their programs, how they achieve diversity of participants and in what ways it influences quality of experience for the program participants. Through this article I am bringing together the thoughts of scientists, industry experts, and programs leaders on how outreach can motivate students to pursue careers in science

X-ray and gamma-ray line production by nonthermal ions

X-ray production was calculated at approximately 6.8 keV by the 2p to 1s transition in fast hydrogen- and helium-like iron ions, following both electron capture to excited levels and collisional excitation. A refinement of the OBK approximation was used to obtain an improved charge exchange cross section. This, and the corresponding ionization cross section were used to determine equilibrium charge fractions for iron ions as functions of their energy. The effective X-ray line production cross section was found to be sharply peaked in energy at about 8 to 12 MeV/amu. Because fast ions of similar energies can also excite nuclear levels, the ratio of selected strong gamma ray line emissivities to the X-ray line emissivity was also calculated. Limits set by this method on the intensity of gamma ray line emission from the galactic center and the radio galaxy Centaurus A are generally lower than those reported in the literature

Evaluation of vascular changes in cattle relative to time-off endophyte-infected tall fescue

Twenty-four steers were grazed on endophyte (Neotyphodium coenophialum)-infected [[Lolium arundinaceum (Schreb.) Darbysh]; E+] tall fescue (TF) and exposed to ergot alkaloids for an 106-d grazing period. Cattle were removed from pasture, placed in dry lots, and fed a non-toxic diet to evaluate changes in vascular contraction relative to time-off E+ TF pasture. Lateral saphenous veins (SV) were biopsied from steers at 0-, 21-, 42-, and 63-d off TF pasture and from 6 control steers at 0- and 63-d off bermudagrass (BG) pasture. To evaluate contractile response, biopsied SV were exposed to increasing concentrations of ergotamine in a multimyograph. Cross-sectional scans of the caudal artery were taken using color Doppler ultrasonography on 0-, 8-, 15-, 21-, 29-, 36-, 42-, and 45-d to determine artery luminal area. Contractility of SV was less for TF than BG steers on d 0, but was similar between the two treatments by d 63. Luminal areas of the caudal arteries in E+ TF steers relaxed over time and were similar to BG steers by 36 d off pastures. Results indicated that alkaloid-induced vasoconstriction in cattle grazed on E+ TF can be relaxed in 5 to 6 weeks after they are placed on non-toxic diets

Synchrotron cooling and annihilation of an E(+)-E(-) plasma: The radiation mechanism for the March 5, 1979 transient

Positron-electron pair radiation is examined as a mechanism that could be responsible for the impulsive phase emission of the March 5, 1979 transient. Synchrotron cooling and subsequent annihilation of the pairs can account for the energy spectrum, the very high brightness, and the approximately 0.4 MeV feature observed from this transient, whose source is likely to be a neutron star in the supernova remnant N49 in the Large Magellanic Cloud. In this model, the observed radiation is produced in the skin layer of a hot, radiation dominated pair atmosphere, probably confined to the vicinity of the neutron star by a strong magnetic field. The width of this layer is only about 0.1 mm. In this layer, approximately 10 to the 12th power generations of pairs are formed (by photon-photon collisions), cooled and annihilated during the approximately 0.15 sec duration of the impulsive phase. The very large burst energy implied by the distance of the Large Magellanic Cloud, and its very rapid release, are unsolved problems. Nonetheless, the possibility of neutron star vibrations, which could transport the energy coherently to the surface, heat the atmosphere mechanically to a hot, pair-producing temperature, and have a characteristic damping time roughly equal to the duration of the impulsive phase are addressed

Implications of cyclotron features in the X-ray spectrum of Her X-1

The X-ray spectra from binary pulsars is investigated through the modification of physical processes due to an intense magnetic field. An effective scattering cross section for line photons and the Coulomb cross section for electron-ion collisions, treating the electrons relativistically, are calculated. The quantization of electron orbits in strong fields are discussed. The absorption cross sections and emission rates for cyclotron photons are calculated. An application of the results to the data from Hercules X-1 is examined