111 research outputs found

    Investigation of Ion Concentration Polarization in original Micro-Nanofluidic devices

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    AbstractIon perm-selectivity is one of the major proprieties of nanofluidic devices. Within the influence of an electric field through an ion-selective nanochannel, a phenomenon called ICP “Ion Concentration Polarization” appears and creates near the micro-nanojunction an ion depletion/concentration zone at the anodic/cathodic side, respectively. Recent works have shown that the anodic depletion can be used as a powerfull preconcentration tool for detection of molecules (DNA, proteins…). Here, we present an original micro-nanofluidic device realized by standard silicon technology which exhibits circular micro-nanojuction. The ICP phenomenon was demonstrated on fluorescent molecules (fluorescein). The radial configuration of the nanochannels may bring different advantages compared to the classical “Bypass” device mostly reported in literature

    Ecological association between a deprivation index and mortality in France over the period 1997 – 2001: variations with spatial scale, degree of urbanicity, age, gender and cause of death

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    <p>Abstract</p> <p>Background</p> <p>Spatial health inequalities have often been analysed in terms of deprivation. The aim of this study was to create an ecological deprivation index and evaluate its association with mortality over the entire mainland France territory. More specifically, the variations with the degree of urbanicity, spatial scale, age, gender and cause of death, which influence the association between mortality and deprivation, have been described.</p> <p>Methods</p> <p>The deprivation index, 'FDep99', was developed at the '<it>commune</it>'(smallest administrative unit in France) level as the first component of a principal component analysis of four socioeconomic variables.</p> <p>Proxies of the Carstairs and Townsend indices were calculated for comparison.</p> <p>The spatial association between FDep99 and mortality was studied using five different spatial scales, and by degree of urbanicity (five urban unit categories), age, gender and cause of death, over the period 1997–2001.</p> <p>'Avoidable' causes of death were also considered for subjects aged less than 65 years. They were defined as causes related to risk behaviour and primary prevention (alcohol, smoking, accidents).</p> <p>Results</p> <p>The association between the FDep99 index and mortality was positive and quasi-log-linear, for all geographic scales. The standardized mortality ratio (SMR) was 24% higher for the <it>communes </it>of the most deprived quintile than for those of the least deprived quintile. The between-urban unit category and between-<it>région </it>heterogeneities of the log-linear associations were not statistically significant. The association was positive for all the categories studied and was significantly greater for subjects aged less than 65 years, for men, and for 'avoidable' mortality.</p> <p>The amplitude and regularity of the associations between mortality and the Townsend and Carstairs indices were lower.</p> <p>Conclusion</p> <p>The deprivation index proposed reflects a major part of spatial socioeconomic heterogeneity, in a homogeneous manner over the whole country. The index may be routinely used by healthcare authorities to observe, analyse, and manage spatial health inequalities.</p

    Wettability Switching Techniques on Superhydrophobic Surfaces

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    The wetting properties of superhydrophobic surfaces have generated worldwide research interest. A water drop on these surfaces forms a nearly perfect spherical pearl. Superhydrophobic materials hold considerable promise for potential applications ranging from self cleaning surfaces, completely water impermeable textiles to low cost energy displacement of liquids in lab-on-chip devices. However, the dynamic modification of the liquid droplets behavior and in particular of their wetting properties on these surfaces is still a challenging issue. In this review, after a brief overview on superhydrophobic states definition, the techniques leading to the modification of wettability behavior on superhydrophobic surfaces under specific conditions: optical, magnetic, mechanical, chemical, thermal are discussed. Finally, a focus on electrowetting is made from historical phenomenon pointed out some decades ago on classical planar hydrophobic surfaces to recent breakthrough obtained on superhydrophobic surfaces

    An overview of geospatial methods used in unintentional injury epidemiology

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    BACKGROUND: Injuries are a leading cause of death and disability around the world. Injury incidence is often associated with socio-economic and physical environmental factors. The application of geospatial methods has been recognised as important to gain greater understanding of the complex nature of injury and the associated diverse range of geographically-diverse risk factors. Therefore, the aim of this paper is to provide an overview of geospatial methods applied in unintentional injury epidemiological studies. METHODS: Nine electronic databases were searched for papers published in 2000-2015, inclusive. Included were papers reporting unintentional injuries using geospatial methods for one or more categories of spatial epidemiological methods (mapping; clustering/cluster detection; and ecological analysis). Results describe the included injury cause categories, types of data and details relating to the applied geospatial methods. RESULTS: From over 6,000 articles, 67 studies met all inclusion criteria. The major categories of injury data reported with geospatial methods were road traffic (n = 36), falls (n = 11), burns (n = 9), drowning (n = 4), and others (n = 7). Grouped by categories, mapping was the most frequently used method, with 62 (93%) studies applying this approach independently or in conjunction with other geospatial methods. Clustering/cluster detection methods were less common, applied in 27 (40%) studies. Three studies (4%) applied spatial regression methods (one study using a conditional autoregressive model and two studies using geographically weighted regression) to examine the relationship between injury incidence (drowning, road deaths) with aggregated data in relation to explanatory factors (socio-economic and environmental). CONCLUSION: The number of studies using geospatial methods to investigate unintentional injuries has increased over recent years. While the majority of studies have focused on road traffic injuries, other injury cause categories, particularly falls and burns, have also demonstrated the application of these methods. Geospatial investigations of injury have largely been limited to mapping of data to visualise spatial structures. Use of more sophisticated approaches will help to understand a broader range of spatial risk factors, which remain under-explored when using traditional epidemiological approaches

    Effect of the scab inoculum and the susceptible parent on resistance to apple scab (Venturia inaequalis) in the progenies of crosses to the scab resistant cv 'Florina'

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    Eight apple progenies all including the scab resistant cv 'Florina' as male parent were inoculated in the glasshouse with scab inocula originating from Angers and Wädenswil, respectively. The seedlings were inoculated twice and classified according to the reaction type. The reactions of the seedlings to the 2 inoculum sources tested were significantly different. Moreover, a clear effect of the susceptible parent on the resistance of the progeny was observed.Effet de l'inoculum et du parent sensible sur la résistance à la tavelure due à Venturia inaequalis dans des descendances de croisements avec un parent résistant, le cultivar «Florina». La création de variétés de pommes résistantes à la tavelure est très importante en vue de diminuer les interventions phytosanitaires dans les vergers. Pour que la résistance soit durable, il est indispensable de tester différents inoculums et de définir les meilleures stratégies d'amélioration génétique. Nous avons inoculé en serre, avec une suspension de conidies de tavelure, 8 descendances issues de croisements avec «Florina», porteur de la résistance «Vf», comme parent mâle. Les inoculums utilisés provenaient d'Angers et de Wädenswil. Les jeunes plantes, inoculées 2 fois et classées selon les types de symptômes, ont réagi d'une manière différente vis-à-vis des 2 sources d'inoculum. Un effet net des parents sensibles à la tavelure sur le niveau de résistance dans la descendance a été observé. Les parents les plus sensibles ont conduit à un pourcentage de plantes sensibles plus élevé dans la descendance que les parents peu sensibles. Dans les programmes d'amélioration, il est donc préférable d'associer au parent résistant des parents peu sensibles
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