The objective of this study was to determine how clinicians make use of the modern multiplex PCR assays (MPAs) to manage patients hospitalized for community-acquired pneumonia (CAP). We studied the use of MPAs in 1648 patients hospitalized for CAP over a 3-year period at the moment of the setup of the new PCR assay. We observed that the use of MPAs for the identification of multiple respiratory pathogens marks a radical change in the investigation of CAP etiology. Surprisingly, the contribution of MPAs to the medical decision-making process varies drastically according to the units of care.

In the framework of the study of long-term storage of the spent nuclear fuel, polycrystalline UO2 samples have been implanted with He ions. The thin implanted layer, close to the free surface is subjected to elastic stresses which are studied by x-ray diffraction (micro Laue diffraction) and a mechanical modeling. A simple expression of the displacement gradient tensor has been evidenced; it concerns only three terms (ε3, ε4 and ε5) which strongly evolve with considered grain orientations. Finally, we show that results obtained with micro diffraction are in very good agreement with conventional x-ray diffraction measurements done in laboratory at macro scale.

Care-related infections are a major public health concern. Their transmission can be associated with environmental factors. This study looks at air contamination around 45 patients colonized with multidrug-resistant organisms (MDROs). We found that 30 hospital rooms (67%) were contaminated with MDRO species and 10 rooms (22%) were contaminated with at least 1 MDRO.

An epidemiological study and the simultaneous evaluation of anti-Hav antibody using radio immunoassay (RIA) and immunoadherence hemagglutination assay (IAHA) was performed during three hepatitis A epidemics in the Tours area (France). Fifty-seven sera from 35 subjects with viral hepatitis type A and 16 sera from nine children who did not develop any clinical signs of hepatitis were studied. The more explosive epidemic occurred in an institution for mentally retarded children (attack rate 68%). The two major outbreaks observed were due to the introduction in the institutions of individuals infected with hepatitis A virus. Two out of three of the index cases had a seafood dinner three to four weeks before onset of jaundice. Sera taken one week after jaundice were always found to be anti-HAV positive by both RIA and IAHA, and sera taken more than three days before the appearance of jaundice were negative by both methods. Sera taken at the peak of the transaminase elevation were anti-HAV positive by RIA but only one out of two were positive by Iaha. The anti-HAV titre by RIA increased from the time of the appearance of jaundice and the highest titres, over 1/20000 were seen only after several months. Observations of subjects in close contact with patients who seroconverted without any manifestation of hepatitis, confirmed the existence of clinically mute infections.

Residual stresses in sputtered ZnO films on Si are investigated and discussed. By means of X-ray diffraction, we show that as-deposited ZnO films encapsulated or not by Si3N4 protective coatings are highly compressively stressed. Moreover, a transition of stress is observed as a function of the post-deposition annealing temperature. After a heat treatment at 800°C, ZnO films are tensily stressed while ZnO films encapsulated by Si3N4 are stress-free. With the aid of in-situ X-ray diffraction, we argue that this thermally-activated stress relaxation can be attributed to a variation of the chemical composition of the ZnO films.

We have developed on the DIFFABS-SOLEIL beamline a biaxial tensile machine with synchrotron standard for in-situ diffraction characterization of thin polycrystalline metallic film mechanical response. The machine has been designed to test cruciform substrates coated by the studied film under controlled applied strain field. Technological challenges comprise the fixation of the substrate, the generation of a uniform strain field in the studied (central) volume, the operations from the beamline pilot. Tests on W and W/Cu multilayers films deposited on polyimide substrates are presented.

The mechanical behavior of nanostructured stratified W/Cu composites prepared by ion beam sputtering has been investigated using a method combining X-ray diffraction and tensile testing. Tests were performed on a synchrotron light source to analyze the elastic response of the tungsten phase. Three different microstructures have been analyzed: the specimen composed of the thinner tungsten layers reveals an elastic behavior different from the one expected assuming bulk elastic constants. However, Transmission Electron Microscopy (TEM) and Grazing-Incidence Small-Angle X-ray Scattering (GISAXS) measurements reveal discontinuities in the copper layers. As the strain in the related copper clusters as well grains boundary contributions are not experimentally accessible, atomistic calculation are of utmost importance. Polycrystalline materials have already been constructed through the Voronoï method and thanks to TEM observations. Atomistic simulation and calculation are underway to validation.

Understanding the mechanical behaviour of nano-structured thin films in relation to their structure, in particular to the grain size, is of high importance for the development of technological applications. Model nanometric multilayer W/Au systems exhibiting different structures are elaborated. These films are supported by a (thin) polyimide substrate. Films mechanical response is characterized experimentally by tensile tests carried out in-situ in a X-ray diffractometer installed on a synchrotron source. X-ray diffraction in transmission geometry has been used to study the deformations of both phases as a function of applied load. This geometry has been developed in the aim of optimizing the experiment time.

The mechanical behavior of W/Cu multilayers with a period of 24 nm and a 1/3 W/Cu thickness ratio prepared by magnetron sputtering was analyzed using a method combining X-ray diffraction and tensile testing. Tests were performed both with a conventional and a synchrotron light source to analyze the elastic response of the system. Comparison between the strain-load curves obtained in both experimental conditions and estimated curves clearly shows that high quality synchrotron measurements are a preliminary condition for size-effect studies. Moreover, cyclic tests were used to determine the elastic domain of each material and compare their mechanical responses. Plastic strain was observed in copper while tungsten layers were still elastically strained until cracks appeared.

Fe $_{1-x}$ Crx thin films on Si and fused-SiO2 substrates were prepared using ion-beam sputtering deposition. Films with x = 0.69 and x = 0.49 were characterised by X-ray diffraction and conversion electron Mössbauer spectroscopy experiments, and concurrently the elastic and plastic behaviours were investigated through indentation tests. For x = 0.69, the paramagnetic bcc structure is observed, while the indentation modulus and hardness values are found to be 160 and 8.7 GPa, respectively. For x = 0.49, a strongly $\langle 200\rangle$ -textured paramagnetic phase is evidenced, having the A15 structure. Mössbauer measurements also allowed the site occupancy to be determined. The structural change from bcc to A15 phase yields a 50% increase in hardness, while the indentation modulus remains unchanged. This particular behaviour is discussed in terms of distances between near neighbours and Burgers vector length in both bcc and A15 structures. The results obtained here provide motivation to pursue the present study through wear experiments.

A computer control deformation set-up has been specifically developed for measuring the elastic and plastic properties of thin films. It combines a piezo-actuated microtensile-testing device, based on an original tripod design, with an optical image acquiring and analysis system for measuring specimen strains. The paper will be partly devoted to describe the experimental deformation set up and its performance through mechanical tests of polyimide and aluminum samples. The Young's moduli, which are deduced from the stress-strain curves, are in good agreement with reported bulk average values. The results confirmed the ability of the equipment for the measurements of very small load and displacement levels, which are a prerequisite for such type of investigations.

Stress/Strain fields associated with thin film buckling induced by compressive stresses or blistering due to the presence of gas bubbles underneath single crystal surfaces are difficult to measure owing to the microscale dimensions of these structures. In this work, we show that micro Scanning X-ray diffraction is a well suited technique for mapping the strain/stress tensor of these damaged structures.

The mechanixcal behavior of W/Cu multilayers with periods ranging from 24 down to 3 nm prepared by ion beam sputtering was analyzed using a method combining X-ray diffraction and tensile testing, and instrumented indentation. Cracks perpendicular to the tensile axis observed by optical microscopy were generated in the films under the largest applied tensile stresses. These cracks may appear in the multilayer while W layers are still in a compressive stress state. Elastic modulus and hardness values were extracted from nano-indentation data. Crack initiation and elastic constants were observed to depend on the period of these multilayers.

The elastic behavior of gold thin films deposited onto Kapton substrate has been studied using in-situ tensile tester in a four-circle goniometer at a synchrotron beam line (LURE facility, France). Knowing the stress tensor in the film, the strong {111} fibre texture was taken into account using the Crystallite Group Method (CGM). CGM strain analysis allows predicting a non linear relationship between strain and sin2 Ψ obtained for the thin films due to the strong anisotropy of gold. In contrast, the average of strains in longitudinal and transversal directions varies linearly with sin2 Ψ. The evolution of the slope of these curves as a function of the applied stresses in the film allowed determining the single-crystal elastic constant s44 of thin gold films.

We have developed an original method allowing to determine the elasticity constants of thin crystalline films deposited on substrates, which combines X-ray diffraction and in situ tensile testing. This technique has been successfully applied to measure the Poisson's ratio in tungsten thin films (150 nm) and molybdenum sublayers (8 nm) of a Mo/Ni multilayer. This paper gives the principles and experimental requirements for the Young's modulus determination.

The determination of residual stresses and the analysis of phases in zirconia layers obtained after oxidation of Zy-4 and Zr-1%Nb-O sheets have been performed using X-ray diffraction with synchrotron radiation at 20 and 400°C. These experimental analyses have been compared with calculations using a micromechanical approach (thermoelastic behaviour) and also with a macroscopic approximation of the thermal stress due to cooling. The main result is the small influence of cooling on the residual stresses developing in the zirconia layer, especially for Zr-1%Nb-O.

A few years ago, some authors have observed by X-ray diffraction analysis in metallic multilayers with small period an in plane expansion combined with a large perpendicular expansion. These trends differ from prediction based on simple continuum elasticity theory. This unexpected result has been the starting point of an experimental development in our laboratory for determining the Poisson's ratio in such systems. Applying the $\sin^{2}\psi$ method on film-substrate set which is elastically deformed in an X-ray diffractometer, it is possible to extract the Poisson's ratio of the film. In this paper, we first detail the theoretical principles of the method and, we show its application on 150 nm thick tungsten films elaborated by ion beam assisted deposition on duralumin substrates. The obtained results demonstrate the feasibility of the method and its good precision.