100 research outputs found
Ramadan fasting influences on food intake consumption, sleep schedule, body weight and some plasma parameters in healthy fasting volunteers
This study examines the changes in the lifestyle that accompanied Ramadan fasting. For this purpose, we followed the questionnaire programming meals, food consumption and sleep rhythm. We also followed changes in plasma biological parameters. The results show that daily energy consumption was not changed and neither was the body weight. Nevertheless, a decrease in fat mass was detected. Concerning plasma, we found a decrease in blood glucose from the 7th day of fasting. This effect was found also at the 21st day, accompanied by a reduction in insulin levels. Our results on plasma lipids showed a decrease in triglycerides with total cholesterol level unchanged. Furthermore, we noted an increased HDL-C against a decreased LDL-C fraction. Taken together, these results suggest that fasting may induce beneficial effects in blood lipid concentrations.Keywords: Ramadan fasting, food intake consumption, sleep schedule, body weight, plasma parameters, healthy fasting volunteersAfrican Journal of Biotechnology Vol. 12(21), pp. 3327-333
Structure de verres de silicophosphate dopés europium : analyse par spectroscopie optique et simulation de dynamique moléculaire
National audienc
Europium site symmetry in sol gel silicophosphate glass : FLN spectroscopy and Molecular Dynamics simulation
International audienc
Breast cancer image classification using pattern-based Hyper Conceptual Sampling method
The increase in biomedical data has given rise to the need for developing data sampling techniques. With the emergence of big data and the rise of popularity of data science, sampling or reduction techniques have been assistive to significantly hasten the data analytics process. Intuitively, without sampling techniques, it would be difficult to efficiently extract useful patterns from a large dataset. However, by using sampling techniques, data analysis can effectively be performed on huge datasets, to produce a relatively small portion of data, which extracts the most representative objects from the original dataset. However, to reach effective conclusions and predictions, the samples should preserve the data behavior. In this paper, we propose a unique data sampling technique which exploits the notion of formal concept analysis. Machine learning experiments are performed on the resulting sample to evaluate quality, and the performance of our method is compared with another sampling technique proposed in the literature. The results demonstrate the effectiveness and competitiveness of the proposed approach in terms of sample size and quality, as determined by accuracy and the F1-measure. 2018This contribution was made possible by NPRP-07-794-1-145 grant from the Qatar National Research Fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the authors.Scopu
Time resolved and temperature dependence of the radiative properties of thiol-capped CdS nanoparticles films
In this work, we present the temperature-dependence and time-resolved photoluminescence (PL) of CdS nanoparticles capped independently with three different ligands thiophenol, thioglycerol, and l-cysteine over a broad temperature range from 10 to 300 K. The respective nanoparticles sizes in the three systems studied in this work are 1.5, 4, and 2 nm as determined from X-ray diffraction (XRD). From the analysis of AFM images, it was found that the lateral particle sizes of capped CdS nanoparticles are greater than those deduced from XRD or optical absorption measurements. The aim of this study is the investigation of the impact of the organic ligands on the radiative recombination dynamics in organically capped CdS nanoparticles. From the PL study and based on the temperature-dependence and time-resolved emission spectroscopy, we conclude that the emission of CdS QDs film originates from recombination of the delocalized carriers in the internal core states with a small contribution of the localized carriers at the interface. The PL decay reveals a biexponential behavior for the entire three samples at all temperatures. One of the two exponential components decays rapidly with a time τ(1) in the range 0.5–0.8 ns, whereas the other decays much more slowly, with a time τ(2) in the range 1–3 ns. The weak activation energy (32–37 meV) deduced from the temperature dependence of the PL intensity suggests the involvement of shallow traps. The analysis of the experimental results reveals a relatively narrow size distribution, an efficient surface passivation, and a satisfactory thermal stability of CdS nanocrystals
Effect of CdS nanocrystals on the photoluminescence of Eu3+-doped silicophosphate sol gel glass
In this work, we investigate the effect of co-doping with CdS nanoparticles on the photoluminescence properties of Eu3+ doped silicophosphate glass prepared via the sol gel method. Infrared spectroscopy (FTIR) revealed the insertion of phosphorus within the silicate network. XRD and TEM analyses revealed the presence of CdS nanoparticles dispersed in the glass matrix. Based on the optical study and the effective mass theory for spherical quantum dots, it was found that CdS nanocrystals have a gap of nearly 3.53 eV and a size of 2.42 nm. The enhancement of Eu3+ emission induced by CdS nanocrystals and thermal annealing was assigned to either an energy transfer via defect states or structural alteration of the glass network around the rare earth ions
Investigation of the local environment of Eu3+ in a silicophosphate glass using site-selective spectroscopy and Molecular Dynamics simulations
Silicophosphate glasses (SiO2-P2O5) doped with Eu3+ ions were synthesized by the sol-gel process. Optical properties of these glasses were investigated by means of emission spectra and lifetime measurements. The Fluorescence Line Narrowing (FLN) technique was also used to explore the local structure around the Eu3+ ions in this host and to understand the role of phosphate as a codopant. As it is the case for aluminum, the ability of phosphate to avoid the rare earth clustering was investigated, and the role of this codopant in modifying the local order around the rare earth ion was evidenced. The analysis of the FLN spectra and lifetime measurements is consistent with this interpretation. Molecular Dynamics simulations were performed to evaluate and confirm these structural features. Two classes of europium sites were distinguished in agreement with the experimental characterization
Molybdenum (Mo) increases endogenous phenolics, proline and photosynthetic pigments and the phytoremediation potential of the industrially important plant Ricinus communis L. for removal of cadmium from contaminated soil.
Cadmium (Cd) in agricultural soil negatively affects crops yield and compromises food safety. Remediation of polluted soil is necessary for the re-establishment of sustainable agriculture and to prevent hazards to human health and environmental pollution. Phytoremediation is a promising technology for decontamination of polluted soil. The present study investigated the effect of molybdenum (Mo) (0.5, 1.0 and 2.0 ppm) on endogenous production of total phenolics and free proline, plant biomass and photosynthetic pigments in Ricinus communis plants grown in Cd (25, 50 and 100 ppm) contaminated soils and the potential for Cd phytoextraction. Mo was applied via seed soaking, soil addition and foliar spray. Foliar sprays significantly increased plant biomass, Cd accumulation and bioconcentration. Phenolic concentrations showed significantly positive correlations with Cd accumulation in roots (R 2 = 0.793, 0.807 and 0.739) and leaves (R 2 = 0.707, 721 and 0.866). Similarly, proline was significantly positively correlated with Cd accumulation in roots (R 2 = 0.668, 0.694 and 0.673) and leaves (R 2 = 0.831, 0.964 and 0.930). Foliar application was found to be the most effective way to deliver Mo in terms of increase in plant growth, Cd accumulation and production of phenolics and proline
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