1,042 research outputs found
Gestational diabetes and endothelial function: impact of gestational insulin resistance on reactive hyperhemia index
Our aim was to characterize endothelial function in gestational diabetes by evaluating the reactive hyperemia index (RHI, LnRHI). A prospective, descriptive and comparative study was conducted on a population of pregnant women aged over 20 and under 36, located in the gestational age group 24-38th week of amenorrhea. They were divided into two groups. Group 1 (G1): group of pregnancies without diabetes, consists of pregnant women with no risk factor for gestational diabetes and with normal fasting blood glucose. Group 2 (G2): group of pregnancies with diabetes, includes pregnancies whose oral glucose tolerance tests (OGTT) came back positive. Anthropo-physiological parameters (age, weight, height, blood pressure (PA) and biochemical parameters (glycemia, insulinemia, HOMA-IR, cholesterol, triglycerides) were measured. RHI and LnRHI were determined at Endopat 2000. The two groups were matched for age, weight, heart rate (HR) and blood pressure (BP). Levels of glucose (G1:0.76±0.11; G2:1.11±0.11; p˂0.0001), insulin (G1:7.67±4.35; G2:22.9±3.75; p˂0.0001), HOMA-IR (G1:1.51±0.97; G2:6.29±1.23; p˂0.0001), total cholesterol (G1:1±0.81; G2:2.49±0.74; p=0.002), HDL cholesterol (G1:0.45±0.23; G2: 0.8±0.19; p=0.004, LDL cholesterol (G1:0.42±0.54; G2:1.39±0.6; p=0.004), triglycerides (G1:0.65±0.49; G2:1.48±0.27; p=0.0018), were significantly higher in the diabetic group. Both RHI and LnRHI were negatively correlated with HOMA-IR (respectively, r=-0.8931, p<0.0001; r=-0.8938; p<0.0001). HOMA-IR index was independently associated with levels of RHI and LnRHI (respectively r²=0.797; p<0.0001); (r²=0.804; p<0.0001)). Thus, gestational insulin resistance would be associated with a change in endothelial function such as a decrease in endothelium-dependent vasodilatation reflecting endothelial dysfunction, hence an increase in cardiovascular risk
Secure Communication in Vehicular Networks - PRESERVE Demo
Security and privacy are fundamental prerequisites for the deployment of vehicular communications. The near-deployment status of Safety Applications for Intelligent Transport Systems (ITS) calls for strong evidence on the applicability of proposed research solutions, notably close-to-reality situations and field-operational trials. The contribution of our work is in this direction: We present a demonstration of the integration and the interoperability among components and security mechanisms coming from different Research and Development projects, as per the PRESERVE project. In fact, we show that the components of the SeVeCom and EVITA projects with the PRESERVE architecture lead to strong and practical security and privacy solutions for Vehicular Ad-hoc Networks (VANETs)
Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications
[EN] Spray pyrolised SnS thin films doped with indium were studied using various optical and electrical techniques.Structural analysis shows that all films crystallise in an orthorhombic structurewith (111) as a preferential direction, without secondary phases. The doping of SnS layers with indium results in better morphology with increased grain size. Absorption measurements indicate a dominant direct transition with energy decreasing from around 1.7 eV to 1.5 eV with increased indium supply. Apart from the direct transition, an indirect one, of energy of around 1.05 eV, independent of indiumdoping, was identified. The photoluminescence study revealed two donors to acceptor transitions between two deep defect levels and one shallower one, with an energy of around 90 meV. The observed transitions did not depend significantly on In concentration. The conductivitymeasurements reveal thermal activation of conductivity with energy decreasing from around 165 meV to 145 meV with increased In content.This work was supported by the Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat Valenciana (Prometeus 2014/044).Urbaniak, A.; Pawlowski, M.; Marzantowicz, M.; Sall, T.; MarĂ, B. (2017). Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications. Thin Solid Films. 636:158-163. https://doi.org/10.1016/j.tsf.2017.06.001S15816363
Etude de la germination de cinq provenances de Tamarindusindica L. en conditions de stress hydrique au Sénégal
Ce présent travail se propose d’évaluer le comportement germinatif de cinq provenances de tamarinier (Tamarindus indica L.) dans des conditions de stress hydrique. Six concentrations croissantes 0 ; - 1,4 ; - 2,8 ; - 4,2 ; - 5,6 ; -7 bar de polyéthylène glycol (PEG 6000) ont été testées. Les résultats ont montré une variabilité de la germination de l’espèce en fonction de l’intensité du stress et de la provenance. Le seuil critique de germination des provenances du tamarinier est de -7 bar. La provenance Sakkal de la zone sahélienne s’est montrée plus tolérante au stress hydrique avec un taux de germination de 2% en conditions de stress sévère. Toutefois, ces faibles résultats sont imputables aux conditions de conservation des graines. Ces informations sur l'écologie et la physiologie de la germination du tamarinier sont vitales, non seulement pour comprendre les variations génétiques des différentes populations de tamarinier au Sénégal, mais aussi pour développer des stratégies pour la conservation de la biodiversité et la restauration des forêts tropicales.Mots clés : Germination, provenances, Tamarindus indica L., stress hydrique, Sénégal
Water-condition effects on rhizobia competition for cowpea nodule occupancy
Two indigenous bradyrhizobia strains displaying different natural behaviours towards water regime (strain ORS 3257, nodulating more frequently in favourable-water conditions and strain ORS 3260, in limited-water conditions) were studied for their competitivity for nodulation of cowpea (Mouridecultivar) under favourable and limited water conditions in non-sterile soil. The nodule occupancy was studied by PCR-RFLP analysis. Both strains showed good competition with other indigenous rhizobia populations under favourable- and limited-water conditions. Competition between the inoculatedstrains in the mixture varied between water regimes. In non-limited-water conditions, strain ORS 3257 was the best competitor, whereas in limited-water conditions, strain ORS 3260 was the best competitor. Results indicated that screening of strains according to their environmental origin could ensuresuccessful rhizobia inoculatio
Genetic Analysis of Viruses Associated with Emergence of Rift Valley Fever in Saudi Arabia and Yemen, 2000-01
The first confirmed Rift Valley fever outbreak outside Africa was reported in September 2000, in the Arabian Peninsula. As of February 2001, a total of 884 hospitalized patients were identified in Saudi Arabia, with 124 deaths. In Yemen, 1,087 cases occurred, with 121 deaths. Laboratory diagnosis of Rift Valley fever virus (RVFV) infections included virus genetic detection and characterization of clinical specimens by reverse transcription-polymerase chain reaction, in addition to serologic tests and virus isolation. Genetic analysis of selected regions of virus S, M, and L RNA genome segments indicated little genetic variation among the viruses associated with disease. The Saudi Arabia and Yemen viruses were almost identical to those associated with earlier RVF epidemics in East Africa. Analysis of S, M, and L RNA genome segment sequence differences showed similar phylogenetic relationships among these viruses, indicating that genetic reassortment did not play an important role in the emergence of this virus in the Arabian Peninsula. These results are consistent with the recent introduction of RVFV into the Arabian Peninsula from East Africa
Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications
[EN] Wide band gap methylammonium lead halide perovskites (CH3NH3PbX3, X=halogen; CH3NH3: MA) are interesting materials for photovoltaic applications. They have recently gained substantial attention because of their high efficiency, low cost, superior optical properties. The most attractive and representative perovskites are methylammonium lead halides (CH3NH3PbX3,) denoted as MAPbX3, X = Br, Cl, I. usually the optical and structural properties of CH3NH3PbBr3 can be adjusted by introducing other extrinsic ions such as chloride and bromide. In this work, instead of replacing the halogens I or Cl with bromine (Br) as usual, we preferred to act on the post-transition metal (Pb). To this end, we replaced lead with chromium (Cr) which is a transition metal and may have the same oxidation state (+2) as lead. MAPb0.93Cr0.07Br3 thin films were deposited on ITO substrate by the spin coating process.
X-ray diffraction analyses indicated the formation of a cubic perovskite with space group Pm3 m. The structural analysis reveals films with (110) and (220) as main peaks. Deposited films showed a strong absorbance in the UVÂżvis range. The band gap values were estimated from absorbance measurements. It was found between 1.60 and 1.80 eV. SEM analysis shows a morphology with good coverage and no apparent crystal orientation.Soro, D.; SidibĂ©, M.; Fassinou, W.; MarĂ, B.; Sall, T.; Fofana, B.; Boko, A.... (2017). Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications. International Journal of Innovative Research in Science, Engineering and Technology. IJIRSET (Online). 6(6):10170-10176. doi:10.15680/IJIRSET.2017.0606007S10170101766
Etude de l’activité antifalcémiante d’extraits de racines de Leptadenia hastata Decne. (Asclepiadacae)
L’objectif de cette étude est d’évaluer l’activité antifalcémiante d’extraits de racines de Leptadenia hastata sur des hémoglobines falciformes et d’identifier les principes actifs à l’origine de cette activité. La méthode employée étudie la réversibilité des drépanocytes, en fonction du temps d’incubation des extraits par rapport aux témoins (eau physiologique, phénylalanine et arginine) sur des échantillons de sang de patients drépanocytaires homozygotes. Des concentrations de 0,05; 0,5; 5 et 10 mg/ml de quatre extraits (méthanol, hexane, acétate d’éthyle et méthanol résiduel) ont été mises en contact avec des drépanocytes de type SS après avoir provoqué leur falciformation avec une solution à 2% de métabisulfite de sodium. L’évaluation a été effectuée toutes les 30 minutes pendant 120 minutes. Les différents extraits ont montré une activité dosedépendante sur la réversibilité de la falciformation des globules rouges avec plus de 80% d’inversion en 120 minutes pour l’extrait méthanolique, le plus actif. Un screening phytochimique a permis de faire une corrélation entre les flavonoïdes et l’activité antifalcémiante des extraits de Leptadenia hastata.Mots clés : Drépanocytose, hémoglobine, activité antifalcémiante, Leptadenia hastata, flavonoïdes
Rift Valley fever outbreak, Mauritania, 1998: seroepidemiologic, virologic, entomologic, and zoologic investigations.
A Rift Valley fever outbreak occurred in Mauritania in 1998. Seroepidemiologic and virologic investigation showed active circulation of the Rift Valley fever virus, with 13 strains isolated, and 16% (range 1.5%-38%) immunoglobulin (Ig) M-positivity in sera from 90 humans and 343 animals (sheep, goats, camels, cattle, and donkeys). One human case was fatal
A molecular method to discriminate between mass-reared sterile and wild tsetse flies during eradication programmes that have a sterile insect technique component
Background The Government of Senegal has embarked several years ago on a project that aims to eradicate Glossina palpalis gambiensis from the Niayes area. The removal of the animal try-panosomosis would allow the development more efficient livestock production systems. The project was implemented using an area-wide integrated pest management strategy including a sterile insect technique (SIT) component. The released sterile male flies originated from a colony from Burkina Faso. Methodology/Principal Findings Monitoring the efficacy of the sterile male releases requires the discrimination between wild and sterile male G.p. gambiensis that are sampled in monitoring traps. Before being released, sterile male flies were marked with a fluorescent dye powder. The marking was however not infallible with some sterile flies only slightly marked or some wild flies contaminated with a few dye particles in the monitoring traps. Trapped flies can also be damaged due to predation by ants, making it difficult to discriminate between wild and sterile males using a fluorescence camera and / or a fluorescence microscope. We developed a molecular technique based on the determination of cytochrome oxidase haplotypes of G. p. gambiensis to discriminate between wild and sterile males. DNA was isolated from the head of flies and a portion of the 5' end of the mitochondrial gene cytochrome oxidase I was amplified to be finally sequenced. Our results indicated that all the sterile males from the Burkina Faso colony displayed the same haplotype and systematically differed from wild male flies trapped in Senegal and Burkina Faso. This allowed 100% discrimination between sterile and wild male G. p. gambiensis. Conclusions/Significance This tool might be useful for other tsetse control campaigns with a SIT component in the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) and, more generally, for other vector or insect pest control programs
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