Diminuer l'anxiété préopératoire des enfants de deux à douze ans et de leurs parents lors d'une chirurgie ambulatoire: revue de littérature des moyens non médicamenteux

La période préopératoire, en pédiatrie, est une source d’anxiété pour plus de la moitié des enfants ainsi que pour leurs parents. De plus, l’anxiété préopératoire peut entraîner des conséquences néfastes chez l’enfant. Identifier les moyens non médicamenteux permettant aux soignants de diminuer l’anxiété préopératoire des enfants de deux à douze ans et de leurs parents lors d’une chirurgie ambulatoire

Electronic structure and stability of materials for organic photovoltaic applications

This word was devoted to the stability in various conditions of materials used in the active layer of organic solar cells. The main goals of this work were first to provide deeper understanding about complex mechanisms occurring in the active layer and second to investigate interfacial degradation pathways involving the active layer. A first part was dedicated to the photo and thermal stability of the polymer blend materials which constitute the active layer of the solar cells. A second section focused on the role of the third component of the active layer which can be undesired residual additives coming from the processing or the desired insertion of a stabilizer additive. A third part concerned the delamination issue which takes place at the active layer / hole transporting layer interface. Finally, a last section was devoted to the energy level alignment between the C60 molecules and various electron transporting substrates. The photo and thermal stability of the active layer / electron transporting layer interface was also studied in this section

Decolonization of asymptomatic carriage of multi-drug resistant bacteria by bacteriophages?

Antimicrobial resistance is a major threat to human and animal health and accounted for up to 4.5 million deaths worldwide in 2019. Asymptomatic colonization of the digestive tract by multidrug resistant (multi-resistant) bacteria such as extended-spectrum beta-lactamase-, or carbapenemase- producing Enterobacterales is (i) a risk factor for infection by these multi-resistant bacteria, (ii) a risk factor of dissemination of these multi-resistant bacteria among patients and in the community, and (iii) allows the exchange of resistance genes between bacteria. Hence, decolonization or reduction of the gastrointestinal tract colonization of these multi-resistant bacteria needs to be urgently explored. Developing new non-antibiotic strategies to limit or eradicate multi-resistant bacteria carriage without globally disrupting the microbiota is considered a priority to fight against antibiotic resistance. Probiotics or Fecal Microbiota Transplantation are alternative strategies to antibiotics that have been considered to decolonize intestinal tract from MDR bacteria but there is currently no evidence demonstrating their efficacy. Lytic bacteriophages are viruses that kill bacteria and therefore could be considered as a promising strategy to combat antibiotic resistance. Successful decolonization by bacteriophages has already been observed clinically. Here, we discuss the current alternative strategies considered to decolonize the digestive tract of multidrug resistant bacteria, briefly describing probiotics and fecal microbiota transplantation approaches, and then detail the in vivo and in vitro studies using bacteriophages, while discussing their limits regarding the animal models used, the characteristics of phages used and their activity in regards of the gut anatomy

Spindle Assembly in Xenopus Egg Extracts: Respective Roles of Centrosomes and Microtubule Self-Organization

In Xenopus egg extracts, spindles assembled around sperm nuclei contain a centrosome at each pole, while those assembled around chromatin beads do not. Poles can also form in the absence of chromatin, after addition of a microtubule stabilizing agent to extracts. Using this system, we have asked (a) how are spindle poles formed, and (b) how does the nucleation and organization of microtubules by centrosomes influence spindle assembly? We have found that poles are morphologically similar regardless of their origin. In all cases, microtubule organization into poles requires minus end–directed translocation of microtubules by cytoplasmic dynein, which tethers centrosomes to spindle poles. However, in the absence of pole formation, microtubules are still sorted into an antiparallel array around mitotic chromatin. Therefore, other activities in addition to dynein must contribute to the polarized orientation of microtubules in spindles. When centrosomes are present, they provide dominant sites for pole formation. Thus, in Xenopus egg extracts, centrosomes are not necessarily required for spindle assembly but can regulate the organization of microtubules into a bipolar array

Designing intrinsically photostable low band gap polymers:a smart tool combining EPR spectroscopy and DFT calculations

A rapid and efficient method to identify the weak points of the complex chemical structure of low band gap (LBG) polymers, designed for efficient solar cells, when submitted to light exposure is reported. This tool combines Electron Paramagnetic Resonance (EPR) using the 'spin trapping method' coupled with density functional theory modelling (DFT). First, the nature of the short life-time radicals formed during the early-stages of photo-degradation processes are determined by a spin-trapping technique. Two kinds of short life-time radical (R and R′O) are formed after 'short-duration' illumination in an inert atmosphere and in ambient air, respectively. Second, simulation allows the identification of the chemical structures of these radicals revealing the most probable photochemical process, namely homolytical scission between the Si atom of the conjugated skeleton and its pendent side-chains. Finally, DFT calculations confirm the homolytical cleavage observed by EPR, as well as the presence of a group that is highly susceptible to photooxidative attack. Therefore, the synergetic coupling of a spin trapping method with DFT calculations is shown to be a rapid and efficient method for providing unprecedented information on photochemical mechanisms. This approach will allow the design of LBG polymers without the need to trial the material within actual solar cell devices, an often long and costly screening procedure

Pesticide contamination interception strategy and removal efficiency in forest buffer and artificial wetland in a tile-drained agricultural watershed

Yves couqet : present adress : UMR7327 on sept. 2012International audiencePesticide pollution is a major threat to aquatic ecosystems that can be mitigated through complementary actions including buffer zones (BZs). This paper discusses the results of 3 yr of field-scale monitoring of the concentration and load transfer of 16 pesticides out of a tile-drained catchment (Bray, France) and their reduction through two BZ: an artificial wetland (AW) and a forest buffer (FB). Typically, the highest concentrations were measured in the first flows following pesticide applications or resuming after periods of low or no flow. An open/close water management strategy was implemented to operate the parallel BZ based on pesticide applications by the farmer. The strategy was efficient in intercepting molecules whose highest concentrations occurred during the first flows following application. Inlet vs. outlet pesticide load reductions ranged from 45% to 96% (AW) and from −32% to 100% (FB) depending on the pesticide molecule and the hydrological year. Partly reversible adsorption was a dominant process explaining pesticide removal; whereas, degradation occurred for sufficiently long water retention time. Apart from the least sorbing molecules (e.g., isoproturon), BZ can partially remove pesticide pollution

Modelling of a constructed wetland for pesticide mitigation

10 p.International audienceThe Water Framework Directive and the Ecophyto 2018 plan provides for measures against water chemical pollution. In the agricultural context, pesticide are a real stress for surrounding environment. Measures have been taken to reduce this stress, namely the reduction of chemical application, and the implantation of buffer zones like artificial wetland at the outlet of the agricultural watershed. A PhD thesis has begun in November 2012 on the modelling of the wetland functioning for pesticide mitigation. This work takes place in the team TAPAHS in the unit Hydrosystem and Bioprocesses of the Institute Irstea. The motivation of this work takes birth in the preceding studies of the team on the removal efficiency of a wetland regarding several pesticides. Several tools are yet available to reach our objectives. An experimental site has been instrumented in the city of Rampillon (France) and a state of art is under construction. The bibliography's study focus on two subjects: the tracer experiments and the constructed wetlands models which have been developed. These tools lead to a methodology which we propose to follow for the next steps of the PhD thesis

The Galactic Isotropic γ\gamma-ray Background and Implications for Dark Matter

We present an analysis of the radial angular profile of the galacto-isotropic (GI) $\gamma$-ray flux--the statistically uniform flux in circular annuli about the Galactic center. Two different approaches are used to measure the GI flux profile in 85 months of Fermi-LAT data: the BDS statistic method which identifies spatial correlations, and a new Poisson ordered-pixel method which identifies non-Poisson contributions. Both methods produce similar GI flux profiles. The GI flux profile is well-described by an existing model of bremsstrahlung, $\pi^0$ production, inverse Compton scattering, and the isotropic background. Discrepancies with data in our full-sky model are not present in the GI component, and are therefore due to mis-modeling of the non-GI emission. Dark matter annihilation constraints based solely on the observed GI profile are close to the thermal WIMP cross section below 100 GeV, for fixed models of the dark matter density profile and astrophysical $\gamma$-ray foregrounds. Refined measurements of the GI profile are expected to improve these constraints by a factor of a few.Comment: 20 pages, 15 figures, references adde