Antibacterial properties of TiO2–Cu composite thin films grown by a one step DLICVD process

The correlations between microstructural features, chemical compositions and antibacterial properties of coatings containing metallic Cu particles embedded in a titanium dioxide matrix have been determined. A Direct Liquid Injection Chemical Vapor Deposition (DLICVD) processwas used for the one step growth of TiO2–Cu composite coatings on various substrates. Titanium tetra-iso-propoxide (TTIP) and copper bis(2,2,6,6-tetramethyl-3,5-heptationate) (Cu(tmhd)2) were used as titanium and copper molecular sources, respectively. This growth process allows a good control of the quantity of metalorganic precursors injected into the CVD reactor and thus of the coating composition. The deposition occurs at 683 K under low pressure (800 Pa). The influence of the main features of the coatings on their antibacterial properties was investigated in order to produce bactericidal surfaces that are durable, non-toxic and containing aminimumamount of active agent. The antibacterial activity on Staphylococcus aureus without any photon activation was measured according to the JIS Z 2801:2000 standard method. An antibacterial activity was detected for a low metal content of ca. 1 at.% Cu, and was found to increasewith the Cu content. It wasmaximal for 3.5 at.% Cu, i.e. TiO2–Cu composite coatings exhibit bactericidal behavior against S. aureus for this optimal composition (relative activity = 100%). In order to better characterize the microbiological behavior of the coatings more discriminating methods derived from the literature were tested to assess the performances of these CVD coatings in terms of efficiency, release of antibacterial agent and accelerated aging

The second ACTRIS inter-comparison (2016) for Aerosol Chemical Speciation Monitors (ACSM) : Calibration protocols and instrument performance evaluations

AbstractThis work describes results obtained from the 2016 Aerosol Chemical Speciation Monitor (ACSM) intercomparison exercise performed at the Aerosol Chemical Monitor Calibration Center (ACMCC, France). Fifteen quadrupole ACSMs (Q_ACSM) from the European Research Infrastructure for the observation of Aerosols, Clouds and Trace gases (ACTRIS) network were calibrated using a new procedure that acquires calibration data under the same operating conditions as those used during sampling and hence gets information representative of instrument performance. The new calibration procedure notably resulted in a decrease in the spread of the measured sulfate mass concentrations, improving the reproducibility of inorganic species measurements between ACSMs as well as the consistency with co-located independent instruments. Tested calibration procedures also allowed for the investigation of artifacts in individual instruments, such as the overestimation of m/z 44 from organic aerosol. This effect was quantified by the m/z (mass-to-charge) 44 to nitrate ratio measured during ammonium nitrate calibrations, with values ranging from 0.03 to 0.26, showing that it can be significant for some instruments. The fragmentation table correction previously proposed to account for this artifact was applied to the measurements acquired during this study. For some instruments (those with high artifacts), this fragmentation table adjustment led to an ?overcorrection? of the f44 (m/z 44/Org) signal. This correction based on measurements made with pure NH4NO3, assumes that the magnitude of the artifact is independent of chemical composition. Using data acquired at different NH4NO3 mixing ratios (from solutions of NH4NO3 and (NH4)2SO4) we observe that the magnitude of the artifact varies as a function of composition. Here we applied an updated correction, dependent on the ambient NO3 mass fraction, which resulted in an improved agreement in organic signal among instruments. This work illustrates the benefits of integrating new calibration procedures and artifact corrections, but also highlights the benefits of these intercomparison exercises to continue to improve our knowledge of how these instruments operate, and assist us in interpreting atmospheric chemistry.Peer reviewe

European aerosol phenomenology - 8 : Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013-2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30-240 min) and long-term data coverage (9-36 months), providing essential information to improve/validate air quality, health impact, and climate models.Peer reviewe

Evolution de la prise en charge de l'hépatite C au cours des dix dernières années

LYON1-BU Santé (693882101) / SudocSudocFranceF

Les pharmaciens français dans le traitement des infections (une histoire ancienne)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Escherichia coli entérohémorragique (EHEC) (de la "maladie du hamburger" au fenugrec)

Au printemps 2011, la plus importante épidémie de gastro-entérite et de syndrome hémolytique et urémique (SHU) liée à Escherichia coli entérohémorragique (EHEC) est apparue en Europe. L'Allemagne a été le pays le plus touché présentant un bilan extrêmement grave: 855 cas de SHU et près de 3 000 cas de gastro-entérites. En France, 9 cas de SHU et 17 cas de gastroentérites ont été recensés. La souche responsable de l'épidémie était Escherichia coli 0104:H4. Ce sérotype, extrêmement rare, n'avait été impliqué que dans quelques cas sporadiques auparavant et n'avait jamais provoqué d'épidémie. Contrairement aux épidémies précédentes liées à EHEC et souvent liées au sérotype 0157:H7, l'épidémie européenne de 2011 à E. coli 0104:H4 a présenté d'importantes différences. Tout d'abord, les SHU représentaient plus de 20 % des cas constatés, ce qui constituait une proportion importante par rapport aux autres épidémies. De plus, la majorité des cas de SHU s'est produite chez des adultes (88 %) plutôt que chez des enfants. Ces différences étaient liées au caractère génétique tout à fait particulier de la souche épidémique E. coli 01 04:H4. En outre, contrairement aux autres souches EHEC, les données actuelles suggèrent que l'homme soit le réservoir de la souche épidémique E. coli 0104:H4. Afin de prévenir le risque d'épidémie lié à E. coli, il paraît indispensable d'améliorer les techniques d'identification des bactéries pathogènes dans le circuit alimentaire et d'élargir les champs de recherche à d'autres sérotypes que E. coli 0157:H7LYON1-BU Santé (693882101) / SudocSudocFranceF

Les anatoxines (état des lieux, préparation, contrôles et perspectives)

L'anatoxine est une substance provenant d'une bactérie qui après le traitement physique, chimique ou biologique perd son pouvoir toxique. Cependant, elle conserve la capacité d'induire une réponse immunitaire protectrice dans l'organisme hôte. C'est cette propriété qui a permis à Gaston Ramon en 1923 de mettre au point les premiers vaccins de type anatoxine. Presque un siècle plus tard, ce groupe de vaccins bien qu'il se soit élargi reste restreint. On y retrouve les vaccins contre la diphtérie, le tétanos, la coqueluche et le botulisme. Les méthodes de détoxification n'ont pas subi de modifications majeures, même si le développement de la biologie moléculaire a permis de préparer les vaccins par génie génétique. Il n'y a toujours pas d'alternatives aujourd'hui à l'utilisation des animaux pour le contrôle de la qualité. C'est dans ce contexte que ce travail a permis de faire un état des lieux des données actuelles. A travers cette analyse, il propose des perspectives d'avenir sur les anatoxines bactériennesLYON1-BU Santé (693882101) / SudocSudocFranceF

Mise au point et validation d'un nouveau milieu de culture sélectif des légionnelles

LYON1-BU Santé (693882101) / SudocSudocFranceF

Histoire des maladies infectieuses au travers les restes anciens (squelettes et momies)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Etude concernant la prescription d'antibiotiques de première intention dans les services de gériatrie de l'Hôpital Lyon-Sud

LYON1-BU Santé (693882101) / SudocSudocFranceF