Impact d'Internet sur la relation médecin-patient en médecine générale du point de vue du patient (étude observationnelle descriptive et analytique auprès de 1521 patients)

Introduction : La relation médecin-malade s'est modifiée selon les sociétés. La vulgarisation médicale s est développée au fil du temps, couronnée à ce jour par l avènement d Internet. Méthode : Etude observationnelle descriptive et analytique par questionnaire auto-administré en ligne sur Internet, du 5 au 27 février 2013, s adressant à toute personne de plus de 18 ans n étant pas médecin. Le lien du questionnaire a été envoyé au contact mail d une boite de réception électronique. Résultats : Sur les 1521 questionnaires analysés, 1176 personnes utilisent Internet comme source d information santé. La recherche d information santé sur Internet à un impact neutre, voire positif sur la relation surtout pour les personnes s estimant en mauvaise santé. La relation est jugée plus constructive pour 15.6% des interrogés et augmente l observance aux traitements dans 22.1% des cas. Le médecin généraliste reste la première source d information santé, et la source la plus digne de confiance. Internet se place en 2ème position. La recherche sur Internet est principalement motivée par une curiosité sur la santé en général, et dans 80.7% n a pas de lien avec la consultation. L information est partagée avec le praticien dans 1/3 des cas. Les patients sont partagés sur l idée de pouvoir consulter le blog de leur médecin généraliste et 48.9% souhaitent pouvoir communiquer avec lui via Internet. Conclusion : L impact est neutre voire légèrement positif. Il est plus présent pour les personnes se considérant en mauvaise santé. Le médecin généraliste doit endosser une nouvelle fonction d éclaireur sur la toile, encore faudrait-il qu une formation adéquate et le temps le lui permette.GRENOBLE1-BU Médecine pharm. (385162101) / SudocSudocFranceF

Effect of the Ligand Binding Strength on the Morphology of Functionalized Gold Nanoparticles

International audienceFunctionalized gold nanoparticles are investigated by density functional theory calculations in the context of cancer radiotherapy. Several typical experimental shapes, including nanostars, nanospheres, and nanorods, are modeled by optimizing Au clusters covered by organic monolayers composed of hydrated short-chain polyethylene glycol (PEG) ligands. The PEGylation stabilizes significantly the stellation of decahedral Au54 by deforming significantly its geometry at the spikes. The higher stability of the PEG molecules adsorbed on this stellated nanocluster with respect to the more spherical icosahedral Au55 and Au79 leads to a larger energy cost to desorb them and thus a weaker propensity for the starred nanoparticle to exchange ligands with the cell membrane, in agreement with experiments. These results open interesting possibilities for advancing our understanding of the cellular uptake of gold nanoparticles

A Water Solvation Shell Can Transform Gold Metastable Nanoparticles in the Fluxional Regime

International audienceSolvated gold nanoparticles have been modeled in the fluxional regime by density functional theory including dispersion forces for an extensive set of conventional morphologies. The study of isolated adsorption of one water molecule shows that the most stable adsorption forms are similar (corners and edges) regardless of the nanoparticle shape and size, although the adsorption strength differs significantly (0.15 eV). When a complete and explicit water solvation shell interacts with gold nanoclusters, metastable in vacuum and presenting a predominance of (100) square facets (ino-decahedra Au55 and Au147), these nanoparticles are found unstable and transform into the closest morphologies exhibiting mainly (111) triangular facets and symmetries. The corresponding adsorption strength per water molecule becomes independent of shape and size and is enhanced by the formation of two hydrogen bonds on average. For applications in radiotherapy, this study suggests that the shapes of small gold nanoparticles should be homogenized by interacting with the biological environment

Monte Carlo simulation of free radical production under keV photon irradiation of gold nanoparticle aqueous solution. Part II: Local primary chemical boost

International audienceHighlights• We calculated radical production around gold/water nanoparticle (GNP/WNP) in water.• Calculations were performed for single keV photon absorption.• In the micrometer range, radicals are overproduced by GNP compared to WNP.• In the nanometer range, radicals are overproduced by small GNP compared to WNP due to Auger electrons.• In the nanometer range, radical production is comparable for large NP

Monte Carlo simulation of free radical production under keV photon irradiation of gold nanoparticle aqueous solution. Part I: Global primary chemical boost

International audienceThe use of gold nanoparticles to enhance radiation therapy efficiency has been thoroughly investigated over the past two decades. While theoretical studies have mostly focused on physical mechanisms and dose enhancement, studies of free radical production are scarce. In this work, we investigated the primary yield of free radicals ( and ) induced by 20–90 keV monoenergetic photons, for small GNPs concentrations. Our study is based on a Monte Carlo approach which enables electron transport down to low energy, both in water and in gold. We obtained, for a gold concentration of 1 , an average chemical enhancement varying from 6 to 14%, depending mostly on the photon energy and, to a lesser extent, on the chemical species and size of the GNP. This enhancement is strongly correlated to the dose deposition enhancement, although not strictly proportional. While supporting the hypothesis that therapeutic efficiency of GNPs may not simply be explained by an overproduction of free radicals in the early stage, our simulation provides inputs for further macroscopic simulations, including cumulative track effects and potentially GNP chemical reactivity

Low-energy electron transport in gold: mesoscopic potential calculation and its impact on electron emission yields

International audienceIn a previous work, we extended and benchmarked the MDM Monte Carlo code with available data for gold metallic media irradiated by electron beams. In this paper, we worked with the aim of improving the cross sections on which our Monte Carlo simulation is based, and which are essential for an accurate description of the transport of electrons in gold. The mesoscopic potential of solid gold has been predicted, and its sensitivity toward electron emission has been evaluated. This potential was derived from the calculation of the electrostatic and atomistic potential by density functional theory and used to calculate inelastic inverse mean free path for electron transport. After integrating these results into our Monte Carlo code, we evaluated the impact of these new cross sections on yields of electron emission from solid gold irradiated by monoenergetic electron beams. We obtained a mesoscopic potential value of − 12.77 eV for our model of bulk metal gold, 27% lower than the one commonly estimated from the Fermi energy. This result impacted on the inverse mean free path for plasmon excitations with a 10% decrease for electrons in the range of 6–30 eV. Regarding electron emission yields, there was no impact of the new mesoscopic potential on the primary electron yields, but for secondary electrons, the emission yields were increased by a factor of up to two depending on the primary beam energy and thickness of the gold foil

Identification of a transient state during the acquisition of temozolomide resistance in glioblastoma

International audienceDrug resistance limits the therapeutic efficacy in cancers and leads to tumor recurrence through ill-defined mechanisms. Glioblastoma (GBM) are the deadliest brain tumors in adults. GBM, at diagnosis or after treatment, are resistant to temozolomide (TMZ), the standard chemotherapy. To better understand the acquisition of this resistance, we performed a longitudinal study, using a combination of mathematical models, RNA sequencing, single cell analyses, functional and drug assays in a human glioma cell line (U251). After an initial response characterized by cell death induction, cells entered a transient state defined by slow growth, a distinct morphology and a shift of metabolism. Specific genes expression associated to this population revealed chromatin remodeling. Indeed, the histone deacetylase inhibitor trichostatin (TSA), specifically eliminated this population and thus prevented the appearance of fast growing TMZ-resistant cells. In conclusion, we have identified in glioblastoma a population with tolerant-like features, which could constitute a therapeutic target

Low versus standard calorie and protein feeding in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group trial (NUTRIREA-3)

International audienc