Bio-accumulation des métaux lourds chez l'oursin Paracentrotus lividus (Lamarck) sur la côte Est de la Méditerranée marocaine

La composition minérale de l’oursin (Paracentrotus lividus), échinoderme benthique fréquent dans la côte Est de la Méditerranée marocaine, concorde avec celle de l’eau du site de prélèvement. En outre, la comparaison des valeurs obtenues sur des oursins récoltés en automne avec celles élevées qui sont obtenues sur des oursins récoltés au printemps suppose l’existence d’un cycle métabolique saisonnier. Les teneurs observées dans l’épithélium digestif et dans les gonades laissent présager les possibilités d’échanges métaboliques entre les systèmes digestif et reproducteur. Ce phénomène est non étudié jusqu’à présent chez les Échinides. Les lysosomes sont les organites cibles où la plupart des éléments, absorbés à l’état de traces sous forme soluble, se concentrent sous forme de précipités de phosphates insolubles

Étude expérimentale de la bio-accumulation des lanthanides chez la moule Mytilus galloprovincialis (Lamarck) du littoral méditerranéen marocain

La microscopie ionique et la microanalyse X ont été utilisées pour détecter in situ, sur coupes histologiques, les éléments bio-accumulés dans la moule Mytilus galloprovincialis, contaminée expérimentalement in vitro par le cérium, le thulium et le lanthane. Les éléments absorbés, sous forme soluble à l’état de traces dans les organites cibles (les lysosomes), sont concentrés sous forme de précipités de phosphate insolubles dans les cellules épithéliales des branchies, des glandes digestives et des palpes labiaux

Description of the characteristics influencing the therapeutic management of infertile couples in western Algeria

Objective: The aim of this work is to describe and identify the characteristics that can influence the care of these infertile couples.Material and method: This is a prospective, monocentric study, extending over a period of four years. It is descriptive of a sample of 760 infertile couples treated in the gynaecology and obstetrics department of the Oran hospital and university establishment of 1st November 1954.&nbsp;Results: The study revealed that primary infertility was 74%. The average duration of infertility was 4.8 ± 0.2 years (minimum 6 months, maximum 25 years); the average age of infertile couples was 33.2 ± 0.4 years (minimum 18 years, maximum 45 years) in women and 39.5 ± 0.5 years (minimum 23 years, maximum 71 years) in men. The male origin of infertility was 30.4%, mixed at 29.2%, female at 27% and unexplained at 13.4%. Oligo-astheno-severe teratospermia dominated male infertility at 30.4%. Tubal causes 23.4% and ovulatory causes 22.8% were mainly of female origin of infertility.&nbsp;Conclusion: The study of these characteristics showed a delay in the treatment of infertile couples. The primary type and long duration of infertility and the advanced age of both women and men make the chances of conception minimal. The male origin of infertility is more important than the female origin, suggesting a deterioration in sperm parameters. Tubal causes in the female origin of infertility are important because of the increasing prevalence of sexually transmitted infections.</p

Influence of Sisal fiber’s treatment on the kinetics of hydration, morphological and thermophysical properties of the composite cementitious mortar

Currently, cement-based bio-composite is a relevant concept for researchers in the building. However, these researches highlighted some handicaps. Plant fibers are acting as a retarder in the setting time of the cement. In this study, Sisal fiber (SF) (4% by mass of cement) was subjected to different treatments to improve bio-composites hydration kinetics (KH) “tested by isotherm calorimetry”. The treatment slowed down both alkaline hydrolysis and mineralization of fiber cell walls by promoting the hydration of cement. This result was coherent with morphological properties. In fact, the images obtained by scanning electron microscopy (SEM) showed a tinier calcium layer around the (SF) treated with NaOH and Paraffin oil on the adhesion surface. The Fourier transform infrared spectroscopy (FTIR) test revealed a disparity in the peaks of the absorption strips of CaCO3 and Ca(OH)2 and thus cement hydration. In addition, the tests results showed a decrease in thermal conductivity (λ) and volumetric heat capacity (ρ.CV) after treatment of (SF). Resistance (RTh) and thermal diffusivity (α) slightly increased with treated fiber. Considering that, the bio-mortar with treated Sisal fiber can be promising material from an insulation point of view