194 research outputs found

    Elements of Study on Dynamic Materials

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    As a preliminary study to more complex situations of interest in small-scale technology, this paper envisages the elementary propagation properties of elastic waves in one-spatial dimension when some of the properties (mass density, elasticity) may vary suddenly in space or in time, the second case being of course more original. Combination of the two may be of even greater interest. Toward this goal, a critical examination of what happens to solutions at the crossing of pure space-like and time-like material discontinuities is given together with simple solutions for smooth transitions and numerical simulations in the discontinuous case. The effects on amplitude, speed of propagation, frequency changes and the appearance of a Doppler-like effect are demonstrated although the whole physical system remains linear

    Quality of life in patients with locked-in syndrome: Evolution over a 6-year period

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    International audienceBackground: Improved knowledge of the quality of life (QoL) of locked-in syndrome (LIS) patients have implications for managing their care, and assists clinicians in choosing the most appropriate interventions. We performed a survey of a population of LIS patients to describe the course of the QoL of LIS patients over a 6-year period and to determine the potential predictive factors of QoL changes over time. Method: This is a study performed over a 6-year period in patients with a LIS diagnosis. Questionnaires were sent in 2007 and 2013. The following data were recorded: i) sociodemographic data; ii) clinical data related to LIS, physical/handicap status, psychological status; iii) self-reported QoL: Anamnestic Comparative Self-Assessment (ACSA); iv) Integration in life: French Reintegration to Normal Living Index (RNLI). Results: Among the 67 patients included in 2007, 39 (58 %) patients returned their questionnaire in 2013. The LIS etiology was stroke in 51 individuals. The QoL of the patients was relatively satisfactory compared to populations in other severe conditions. Twenty-one (70 %) individuals reported a stable/improved QoL between 2007 and 2013. The physical/handicap statuses in 2007 and 2013 were not related to the QoL 6 years later, with the exception of one communication parameter: the individuals who used yes-no code reported significantly lower QoL levels than those who did not in 2013. Discussion: In opposition to a widespread opinion, LIS persons report a relatively satisfactory QoL level that stays stable over time, suggesting that life with LIS is worth living. Preservation of autonomy and communication may help them to live as normal life as possible

    Effects of alpha-linolenic acid vs. docosahexaenoic acid supply on the distribution of fatty acids among the rat cardiac subcellular membranes after a short- or long-term dietary exposure

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    Previous work showed that the functional cardiac effect of dietary alpha-linolenic acid (ALA) in rats requires a long feeding period (6 months), although a docosahexaenoic (DHA) acid-supply affects cardiac adrenergic response after 2 months. However, the total cardiac membrane n-3 polyunsaturated fatty acid (PUFA) composition remained unchanged after 2 months. This delay could be due to a specific reorganization of the different subcellular membrane PUFA profiles. This study was designed to investigate the evolution between 2 and 6 months of diet duration of the fatty acid profile in sarcolemmal (SL), mitochondrial (MI), nuclear (NU) and sarcoplasmic reticulum (SR) membrane fractions. Male Wistar rats were randomly assigned to 3 dietary groups (n = 10/diet/period), either n-3 PUFA-free diet (CTL), or ALA or DHA-rich diets. After 2 or 6 months, the subcellular cardiac membrane fractions were separated by differential centrifugations and sucrose gradients. Each membrane profile was analysed by gas chromatography (GC) after lipid extraction. As expected the n-3 PUFA-rich diets incorporated n-3 PUFA instead of n-6 PUFA in all the subcellular fractions, which also exhibited individual specificities. The diet duration increased SFA and decreased PUFA in SL, whereas NU remained constant. The SR and MI enriched in n-3 PUFA exhibited a decreased DHA level with ageing in the DHA and CTL groups. Conversely, the n-3 PUFA level remained unchanged in the ALA group, due to a significant increase in docosapentaenoic acid (DPA). N-3 PUFA rich diets lead to a better PUFA profile in all the fractions and significantly prevent the profile modifications induced by ageing. With the ALA diet the n-3 PUFA content, particularly in SR and SL kept increasing between 2 and 6 months, which may partly account for the delay to achieve the modification of adrenergic response

    TP53 transcription factor for the NEDD9/HEF1/Cas-L gene: potential targets in Non-Small Cell Lung Cancer treatment

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    International audienceLung cancer is a serious public health problem. Although there has been significant progress in chemotherapy, non-small cell lung cancer is still resistant to current treatments, primarily because of the slow rate of cell development. It is thus important to find new molecules directed against targets other than proliferation agents. Considering the high proportion of mutant proteins in tumor cells, and the high rate of mutation of the TP53 gene in all cancers, and in NSCLC in particular, this gene is a perfect target. Certain new molecules have been shown to restore the activity of mutated p53 protein, for example PRIMA-1, which reactivates the His273 mutant p53. In a previous study, we presented triazine A190, a molecule with a cytostatic activity that blocks cells in the G1 phase and induces apoptosis. Here, we show that A190 not only restores mutant p53 activity, but also induces an overexpression of the NEDD9 gene, leading to apoptotic death. These findings might offer hope for the development of new targeted therapies, specific to tumor cells, which spare healthy cell

    Impact environnemental de la diffusion de produits phytosanitaires par ruissellement

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    L’agriculture moderne s’est appuyĂ©e sur l’utilisation croissante de produits phytosanitaires. Toutefois, la contamination des milieux comme les impacts sanitaires sont aujourd’hui avĂ©rĂ©s. Le transfert de ces produits vers les eaux de surface ou souterraines pourrait conduire Ă  l’exposition de la population gĂ©nĂ©rale rĂ©sidant Ă  proximitĂ© des zones agricoles. Notre objectif vise Ă  dĂ©finir une mĂ©thodologie pour caractĂ©riser l’alĂ©a de pollution rĂ©sultant tant de l’épandage direct de produits phytosanitaires que de leur transfert par ruissellement au sein d’un bassin versant. Cette mĂ©thodologie est testĂ©e sur deux zones oĂč les prĂ©cipitations intenses provoquent d’importants ruissellements, l’une en Languedoc-Roussillon et l’autre Ă  l’extrĂȘme Nord du Cameroun. La premiĂšre phase consiste Ă  quantifier la pression phytosanitaire au niveau des communes de la zone d’étude grĂące Ă  l’Indicateur de FrĂ©quence des Traitements (IFT). Ensuite, une analyse hydrologique, qui s’appuie sur l’adaptation de la mĂ©thode cartographique IRIP (Indicateur de l’alĂ©a inondation par Ruissellement Intense Pluvial), permet de caractĂ©riser les zones propices Ă  la production ou Ă  l’accumulation du ruissellement. Enfin, l’utilisation d’un SystĂšme d’Information GĂ©ographique (SIG) permet, en recoupant l’IFT et ces zones ruisselantes, de dĂ©finir diffĂ©rents niveaux d’alĂ©a de pollution au sein du bassin versant. Cette Ă©tude devrait permettre d’affiner la dĂ©finition de l’exposition humaine dans les analyses Ă©pidĂ©miologiques en population gĂ©nĂ©rale. Cependant, l’absence de prise en compte de la propagation aĂ©rienne et souterraine de ces produits constitue une de ses principales limites. Enfin, elle pourrait ĂȘtre complĂ©tĂ©e par la prise en compte des transferts d’eau souterrains pour mieux Ă©valuer la pollution au sein de l’hydrosystĂšme.Modern agriculture is based on the increasing use of pesticides. Environmental contamination by pesticides as well as the health impacts are now proven. The transfer of these products into surface waters or groundwater could lead to exposure of the general population living near agricultural areas. The study aims to provide a useful methodology to characterize the pollution risk resulting from the direct application of plant protection products and their transfer by runoff within a watershed. This methodology is tested on two areas where intense rainfall are causing major runoff, one in Languedoc-Roussillon (France) and the other in the extreme north of Cameroon. The first step is to quantify the pest pressure within the municipalities in the studied areas with the Treatment Frequency Index (IFT). Then in a second time a hydrological analysis, based on the adaptation of the cartographic method IRIP (Indicator of the flood hazard by Intense Pluvial runoff), allows a characterization of areas suitable for the production or accumulation of runoff. Finally, the use of a Geographic Information System (GIS) allows, by matching the IFT and the streaming areas to define different levels of pollution hazard within the watershed. This study should refine the definition of human exposure in epidemiological analyzes in the general population. However, the lack of consideration of the air and underground propagation of these products is one of its major limitations. Finally, it could be supplemented by the inclusion of underground water transfers to better assess the pollution in the river system

    Process Parameters Optimization, Characterization, and Application of KOH-Activated Norway Spruce Bark Graphitic Biochars for Efficient Azo Dye Adsorption

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    In this work, Norway spruce bark was used as a precursor to prepare activated biochars (BCs) via chemical activation with potassium hydroxide (KOH) as a chemical activator. A Box–Behnken design (BBD) was conducted to evaluate and identify the optimal conditions to reach high specific surface area and high mass yield of BC samples. The studied BC preparation parameters and their levels were as follows: pyrolysis temperature (700, 800, and 900 °C), holding time (1, 2, and 3 h), and ratio of the biomass: chemical activator of 1: 1, 1.5, and 2. The planned BBD yielded BC with extremely high SSA values, up to 2209 m2·g−1. In addition, the BCs were physiochemically characterized, and the results indicated that the BCs exhibited disordered carbon structures and presented a high quantity of O-bearing functional groups on their surfaces, which might improve their adsorption performance towards organic pollutant removal. The BC with the highest SSA value was then employed as an adsorbent to remove Evans blue dye (EB) and colorful effluents. The kinetic study followed a general-order (GO) model, as the most suitable model to describe the experimental data, while the Redlich–Peterson model fitted the equilibrium data better. The EB adsorption capacity was 396.1 mg·g−1. The employment of the BC in the treatment of synthetic effluents, with several dyes and other organic and inorganic compounds, returned a high percentage of removal degree up to 87.7%. Desorption and cyclability tests showed that the biochar can be efficiently regenerated, maintaining an adsorption capacity of 75% after 4 adsorption–desorption cycles. The results of this work pointed out that Norway spruce bark indeed is a promising precursor for producing biochars with very promising properties

    Assessing seasonal and interannual changes in carbonate chemistry across two time-series sites in the North Western Mediterranean Sea

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    Sustained time-series measurements are crucial to understand changes in oceanic carbonate chemistry. In the North Western Mediterranean Sea, the temporal evolution of the carbonate system is here investigated based on two 10-year time-series (between January 2010 and December 2019) of monthly carbonate parameters measurements at two sampling sites in the Ligurian Sea (ANTARES and DYFAMED). At seasonal timescale, the seawater partial pressure of CO2 (pCO2) within the mixed layer is mostly driven by temperature at both sites, and biological processes as stated by the observed relationships between total inorganic carbon (CT), nitrate and temperature. This study suggests also that mixing and water masses advection could play a role in modulating the CT content. At decadal timescale, significant changes in ocean chemistry are observed with increasing trends in CT (+3.2 ± 0.9 ”mol.kg−1.a−1 – ANTARES; +1.6 ± 0.8 ”mol.kg−1.a−1 – DYFAMED), associated with increasing pCO2 trends and decreasing trends in pH. The magnitude of the increasing trend in CT at DYFAMED is consistent with the increase in atmospheric pCO2 and the anthropogenic carbon transport of water originating from the Atlantic Ocean, while the higher trends observed at the ANTARES site could be related to the hydrological variability induced by the variability of the Northern Current

    Report on demo mission and dissemination pathways of obtained data based on different observational platforms

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    This document describes the deployment of instrumentation in the Eastern tropical Atlantic area and shows the preliminary data acquired

    The Journey of SCAPs (Stem Cells from Apical Papilla), from Their Native Tissue to Grafting: Impact of Oxygen Concentration

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    Tissue engineering strategies aim at characterizing and at optimizing the cellular component that is combined with biomaterials, for improved tissue regeneration. Here, we present the immunoMap of apical papilla, the native tissue from which SCAPs are derived. We characterized stem cell niches that correspond to a minority population of cells expressing Mesenchymal stromal/Stem Cell (CD90, CD105, CD146) and stemness (SSEA4 and CD49f) markers as well as endothelial cell markers (VWF, CD31). Based on the colocalization of TKS5 and cortactin markers, we detected migration-associated organelles, podosomes-like structures, in specific regions and, for the first time, in association with stem cell niches in normal tissue. From six healthy teenager volunteers, each with two teeth, we derived twelve cell banks, isolated and amplified under 21 or 3% O2. We confirmed a proliferative advantage of all banks when cultured under 3% versus 21% O2. Interestingly, telomerase activity was similar to that of the highly proliferative hiPSC cell line, but unrelated to O2 concentration. Finally, SCAPs embedded in a thixotropic hydrogel and implanted subcutaneously in immunodeficient mice were protected from cell death with a slightly greater advantage for cells preconditioned at 3% O2
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