Multi-residues analysis of pre-emergence herbicides in fluvial sediments : application to the mid-Garonne River

Contamination of man and ecosystems by pesticides has become a major environmental concern. Whereas many studies exist on contamination from agriculture, the effects of urban sources are usually omitted. Fluvial sediment is a complex matrix of pollutants but little is known of its recent herbicide content. This study proposes a method for a fast and reliable analysis of herbicides by employing the accelerated solvent extractor (ASE). The aim of the study is to show the impact of a major town (Toulouse) on the herbicide content in the river. In this study, three herbicide families (i.e. s-triazine, substituted ureas and anilides) were analysed in fluvial sediment fractions at 11 sampling sites along the mid-Garonne River and its tributaries. River water contamination by herbicides is minor, except for at three sites located in urban areas. Among the herbicidal families studied, urban and suburban areas are distinguished from rural areas and were found to be the most contaminated sites during the study period, a winter low-water event. The herbicide content of the coarse sediment fractions is about one third of that found in the fine fractions and usually ignored. The distribution of pesticide concentrations across the whole range of particle sizes was investigated to clarify the role of plant remains on the significant accumulation in the coarse fractions

Effet de l'état métallurgique sur les propriétés mécaniques d'éprouvettes amincies

National audienceL'affinement des échelles de modélisation numérique s'accompagne du développement d'outils de caractérisation appropriés. La fabrication et la réponse mécanique d'éprouvettes de traction d'épaisseurs micrométriques constituées d'alliage 718 font l'objet de la présente étude. A partir d'une même coulée, différents états métallurgiques sont étudiés. L'alliage hypertrempé (solution solide), l'alliage vieilli (durcissement structural) avec ou sans phase delta aux joints de grains ainsi que l'effet de la taille de grain sont explorés. Les objectifs visés sont d'une part, la validation d'une méthode de prélèvement et de test d'éprouvettes minces permettant d'accéder à la description de gradients de propriétés dans des matériaux massifs et d'autre part, d'évaluer pour différents états métallurgiques de l'alliage 718, les épaisseurs seuils en dessous desquelles la limite d'élasticité dépend de l'épaisseur de l'éprouvette. Les essais qui ont été réalisés montrent que la préparation des éprouvettes ne semble pas altérer les mécanismes de déformation spécifiques des microstructures étudiées. Un effet d'épaisseur conduisant à la définition d'un seuil a été constaté aussi bien sur la limite d'élasticité que sur la contrainte à rupture pour les microstructures présentant un durcissement structural

Surveillance tensionnelle par automesure des patients cancéreux traités par anti-angiogénique (Comparaison de deux méthodes d'automesure et de leur impact sur la qualité de vie)

Les traitements anti-angiogéniques (AAGG) occupent une place importante dans la prise en charge thérapeutique de nombreux cancers. De par leur action systémique, ils sont souvent responsables d'hypertension artérielle (HTA), ce qui implique une surveillance tensionnelle régulière pour maintenir une balance bénéfice-risque favorable. A ce jour, l'apport de l'automesure tensionnelle et de la télésurveillance tensionnelle n'a pas été évalué dans cette indication. Huit patients recrutés au CHU d'Angers et à l'ICO Paul Papin et traités par un AAGG (Sunitinib - Sutent ou Bevacizumab - Avastin) ont bénéficié d'une surveillance tensionnelle selon 2 protocoles d'automesure différents, l'un suivant les recommandations de la HAS et l'autre celles du NCI-CTCAE, durant 2 cycles de traitement. Sept patients, recrutés dans les mêmes conditions mais ne bénéficiant pas d'un traitement AAGG ont été suivi selon le même protocole. L'impact psychologique du suivi par automesure couplée ou non à une télésurveillance a également été évaluée par une enquête. Les résultats montrent un impact significatif du protocole d'automesure pour la détection des épisodes d'HTA, malgré une contrainte plus importante liée à la répétition des mesures (protocole HAS). L'utilisation d'un système de télésurveillance de l'automesure s'accompagne d'une amélioration de la qualité du recueil des données, facilite la détection d'une HTA, permet une réduction des délais d'interventions et augmente le sentiment de sécurité du patient pour son suivi. Ces résultats préliminaires encouragent le recourt à des systèmes de télésurveillance pour la prise en charge des patients traités par AAGG.Anti-angiogenic treatments ( AAGG ) occupy an important place in management of many cancers. Arterial hypertension is a commonly reported side-effect. To date, the contribution of remote blood pressure monitoring was not evaluated. Eight patients recruited at the CHU of Angers and ICO Paul Papin and treated by AAGG ( Sunitinib - Sutent or Bevacizumab - Avastin ) benefited from monitoring blood pressure self-measurement (by HAS and NCI-CTCAE recommendations) during two cycles of treatment. Seven patients were recruited in the same conditions but does not benefit from AAGG treatment were followed too. The psychological impact of monitoring was evaluated by an inquiry .The results show a significant impact of self-measurement protocol for the detection of hypertension. A remote monitoring system is accompanied by an improvement quality of data, facilitates the detection of hypertension, reduces the intervention time and increases the sense of security. These preliminary results encourage the uses of remote monitoring systems for the management of patients treated with AAGG.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Barotrauma e medicina dentária

Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas MonizNo ambiente do mergulho ou da aviação, os profissionais ou praticantes recreativos estão sujeitos a variações bruscas de pressão (hidrostática/atmosférica). Estas variações de pressão são ainda mais importantes para mergulhadores, onde se encontra uma taxa mais elevada de casos de barodontalgia do que em aviões. Estes barotraumas podem comprometer a segurança de mergulhar e voar (1). A barodontalgia é um sintoma frequentemente experimentado durante o mergulho. É portanto essencial assegurar que as cáries dentárias, e as restaurações infiltradas ou fraturadas sejam tratadas de forma adequada para garantir o conforto e a segurança do mergulhador (2). Estas restrições barotraumáticas obrigam os médicos dentistas a ter uma abordagem diferente das técnicas convencionais. No domínio da endodontia, estudos demonstraram que o método de condensação vertical poderia ser a técnica profilática mais adequada em termos de estanquicidade os canais radiculares (3). No domínio da dentisteria, a escolha do material adesivo e restaurador é de primordial importância na prevenção das micro-infiltrações na interface dentina/resina composta (4) Nas últimas décadas, tem havido um aumento significativo do número de viajantes aéreos, implicando por esse facto que o risco de desenvolver dor dentária durante um voo é muito maior para o público desinformado. No entanto, o campo da barodontalgia aeronáutica é uma área recente da odontologia que tem dificuldade em ser integrada nos programas de medicina dentária actuais (5).In the diving or aviation environment, professionals or recreational practitioners are subjected to sudden pressure variations (hydrostatic/atmospheric). These pressure variations are even more important for divers, where a higher rate of barodontalgia cases is found than in aircraft. These barotraumas can compromise the safety of diving and flying (1). Barodontalgia is a symptom frequently experienced during diving. It is therefore essential to ensure that dental caries, and infiltrated or fractured restorations are treated appropriately to ensure diver comfort and safety (2). These barotraumatic restrictions force dental practitioners to take a different approach to conventional techniques. In the domain of endodontics, studies have shown that the vertical condensation method could be the most suitable prophylactic technique in terms of sealing the root canals (3). In the field of dentistry, the choice of adhesive and restorative material is of primary importance in preventing microleakage at the dentin/resin composite interface (4) In recent decades, there has been a significant increase in the number of air travellers, implying by this fact that the risk of developing dental pain during a flight is much higher for the uninformed public. However, the field of aeronautical barodontalgia is a recent area of dentistry that has difficulty being integrated into current dental programmes (5)

Ventilator-induced lung injury: historical perspectives and clinical implications

Mechanical ventilation can produce lung physiological and morphological alterations termed ventilator-induced lung injury (VILI). Early experimental studies demonstrated that the main determinant of VILI is lung end-inspiratory volume. The clinical relevance of these experimental findings received resounding confirmation with the results of the acute respiratory distress syndrome (ARDS) Network study, which showed a 22% reduction in mortality in patients with the acute respiratory distress syndrome through a simple reduction in tidal volume. In contrast, the clinical relevance of low lung volume injury remains debated and the application of high positive end-expiratory pressure levels can contribute to lung overdistension and thus be deleterious. The significance of inflammatory alterations observed during VILI is debated and has not translated into clinical application. This review examines seminal experimental studies that led to our current understanding of VILI and contributed to the current recommendations in the respiratory support of ARDS patients

Herbicide accumulation and evolution in reservoir sediments

The aim of the present study was to understand the effect of reservoir configurations on sediment pesticide fate. Two dams were selected on the River Garonne, in southwest France: Carbonne and Golfech, both with reservoirs subject to accumulation of herbicide-contaminated sediment. They are situated upstream and downstream respectively of an agricultural and urban area: the Mid-Garonne. The results presented include pesticide concentrations and C/N ratios in the smaller sediment particles (b2 mm) and values of oxygenation and herbicide concentrations in the water. The dynamic behaviour of sediment in the reservoirs is discussed. The present study shows that the theoretical lifespan (weak remanence in vitro) and the results actually observed in the sediment are conflicting. Pesticide contamination in Carbonne indicates conservation, even accumulation, of herbicide molecules while in Golfech transformation processes clearly dominate. The hydromorphological position of Golfech reservoir, i.e. located at the junction of two rivers with contrasting hydrological regimes and very different oxygenation conditions, leads to accelerated pesticide desorption or degradation. Unfortunately, this configuration is rare

Urban Impact on Selected Pre-Emergence Herbicides in Sediment cores

In order to determine if pre-emergence herbicide pollutant source, mixing with many others from residential and industrial activities, has an effect on pollutant degradation, three sediment cores were sampled in appropriate sites of the Garonne river near the city of Toulouse: two in rural surroundings, one upstream and one downstream from the urban area away from its influence, and one downtown close to Toulouse. Atrazine and DEA were analysed and, using DAR pesticide/metabolite ratio, an inferior metabolisation ratio was highlighted in the urban sediment compared to the rural ones, regardless of sedimentation rate, organic carbon content, topography or differences in the intensity of surrounding activities between rural cores

Nouvelles recherches sur l'ensemble paléochrétien et médiéval d'Ereruyk en Arménie

Premiers résultats des campagnes d'investigations menées en 2009-2011 sur le site paléochrétien et médiéval d'Ereruyk, dans le nord-ouest de la république d'Arménie, par une équipe du LA3M (UMR 7298, Aix-Marseille Université / CNRS)

Biotribology of the ageing skin—why we should care

Ageing of populations has emerged as one of the most pressing societal, economic and healthcare challenges currently facing most nations across the globe. The ageing process itself results in degradation of physiological functions and biophysical properties of organs and tissues, and more particularly those of the skin. Moreover, in both developed and emerging economies, population ageing parallels concerning increases in lifestyle-associated conditions such as Type 2 diabetes, obesity and skin cancers. When considered together, these demographic trends call for even greater urgency to find clinical and engineering solutions for the numerous age-related deficits in skin function. From a tribological perspective, detrimental alterations of skin biophysical properties with age have fundamental consequences on how one interacts with the body's inner and outer environments. This stems from the fact that, besides being the largest organ of the human body, and also nearly covering its entirety, the skin is a multifunctional interface which mediates these interactions. The aim of this paper is to present a focused review to discuss some of the consequences of skin ageing from the viewpoint of biotribology, and their implications on health, well-being and human activities. Current and future research questions/challenges associated with biotribology of the ageing skin are outlined. They provide the background and motivation for identifying future lines of research that could be taken up by the biotribology and biophysics communities

Physics of the frequency response of rectifying organic Schottky diodes

International audienceThe frequency response of unipolar organic Schottky diodes used in a rectifying circuit, such as an RFID tag, has been investigated in detail. The time dependent response of rectifying circuits has been simulated solving both the Drift Diffusion and Poisson equations to model the hole transport within the diode, coupled with time dependent circuit equations. Several approximations have also been discussed. It turns out that the cut off frequency of the rectifying circuit is indeed limited by the carrier time-of-flight and not by the diode equivalent capacitance. Simulations have also been confirmed by comparison with experiments, involving diodes with different mobilities and thicknesses. This work confirms that the 13.56MHz frequency can be reached using polymer semiconductors, as already experimentally demonstrated in the literature, by an adequate control of the active layer thicknes