Abstract... Raman spectroscopy is currently part of the instrumentation suite of the ESA Exomars mission for the remote detection of life signatures in the Martian surface and subsurface.Terrestrial analogues of Martian sites have been identified and the biogeological modifications incurred as a result of extremophiliccyanobacteral activity have been studied. In simulation of the inclusion of organic biomolecules found in crystal matrices in, for example, impact craters we have studied the Raman spectra of several PAHs and usnic acid under calcite and gypsum crystal. Spectra were obtained from anthracene, phenanthrene, naphthalene, tetracene, chrysene, pyrene and triphenylene and usnic acid crystals through calcite and gypsum surfaces. Although the resulting spectra have peaks attributed to calcite and gypsum, the PAH compounds were identified by their characteristic bands. Anthracene, phenanthrene and naphthalene were mixed together; tetracene, chrysene, pyrene and triphenylene were mixed together, and Raman spectra were collected from these mixtures under similar conditions to determine the limits of detection in admixture. Spectra of several pure compounds and in admixture could be ready obtained non- invasively from calcite and gypsum within ten minutes with little or no sample preparation.Information from this study will be useful for targetingMartian sites using a miniaturized Raman instrument where the biosignatures of relict or extant life could remain in the geological record.
Abstract... Thin films of pure ZnO have been prepared on glass substrate using the Sol–Gel spin coating technique. Transmittance and absorbance spectra have been measured by using double beam UV-Visible 1800 spectrophotometer in the wavelength range (300-800)nm. It was found that the absorbance decreases with increasing the wavelength, while the transmittance increases with rising the wavelength. The transmittance exceeds 90% in the visible light region and in the near-infrared. The obtained results have shown that intrinsic ZnO is a semiconductor of wide optical energy band gap estimated to be 3.33eV. Furthermore, some optical properties and optical constants have been calculated from absorption and transmission measurements such as absorption coefficient, Urbach energy, extinction coefficient, refractive index and dielectric constant.
Abstract... Vitamin D is an important prohormone with several biological roles. The high prevalence of vitamin D deficiency around the world highlighted the need for studying vitamin D serum status in the community. This prospective study aimed to evaluate the serum vitamin D concentrations among adult population in Misurata and to explore how its concentration is affected by factors like gender, age and menopausal status. To achieve the aim of the study, a total of 125 adult samples were collected and divided based on gender and age into four groups (premenopausal women, postmenopausal women, men below and above 45 years). Samples were analyzed by ELISA.
According to the results, about 20% of the younger males had sufficient vitamin D levels, 45% with insufficient levels and deficiency was reported in about 35% of the cases. The results in the other three groups were similar and consistent with the hypothesis where no individual in the three groups found with sufficient vitamin D. As hypothesized, younger males had higher serum vitamin D concentrations in comparison to younger females which is probably due the limited exposure to sun light as a result of factors such as hijab, sun screen usage and reduced outdoor activities. Furthermore, age impact was critical in the male groups but not in the female groups where pre and postmenopausal women exhibited comparable results.
In few words, vitamin D deficiency is predominant among the population of Misurata which emphasizes the need for empirical treatment with vitamin D supplementation as an appropriate solution.
Abstract... In the present work an attempt has been made to investigate the characteristics of particles emitted in inelastic collisions of silicon nuclei with the nuclei of nuclear emulsion at the momentum of 4.5 A GeV/c. At the same time the study of Multiplicity correlations,
Through studying 〈n_b 〉⁄(〈n_g 〉 )versus n_s ,a new phase at high density, high temperature region around QGP is assumed to be formed.