Projet de recherche sur les systèmes de production dans la zone de Goubellat, Tunisie : proposition pour une deuxième phase du projet, 1990-1995

Draf

Effect of Plasmonic Gold Nanoprisms on Biofilm Formation and Heat Shock Proteins Expression in Human Pathogenic Bacteria

Gold nanoparticles have gained interest in biomedical sciences in the areas of nano-diagnostics, bio-labeling, drug delivery, and bacterial infection. In this study, we examined, for the first time, the antibacterial and antibiofilm properties of plasmonic gold nanoprisms against human pathogenic bacteria using MIC and crystal violet. In addition, the expression level of GroEL/GroES heat shock proteins was also investigated by western blot. Gold nanoparticles were characterized by TEM and EDX, which showed equilateral triangular prisms with an average edge length of 150 nm. Antibacterial activity testing showed a great effect of AuNPs against pathogenic bacteria with MICs values ranging from 50 μg/mL to 100 μg/mL. Nanoparticles demonstrated strong biofilm inhibition action with a percentage of inhibition ranging from 40.44 to 82.43%. Western blot analysis revealed that GroEL was an AuNPs-inducible protein with an increase of up to 66.04%, but GroES was down-regulated with a reduction of up to 46.81%. Accordingly, plasmonic gold nanoprisms, could be a good candidate for antibiotics substitution in order to treat bacterial infections

In vitro antimicrobial activity of Pistacia lentiscus L. edible oil and phenolic extract.

International audiencePistacia lentiscus L. is known in some Tunisian forest area by its fixed oil used in traditional medicine as an antiseptic product. This investigation is the first to study the antimicrobial activity of P.lentiscus edible oil and its phenolic extract. Oil was extracted from fruits harvested from six provenances located in Tunisia. The antimicrobial activity was tested using disc diffusion assay and the broth dilution method. Kbouch and Sidi Zid oils were most efficient (p < 0.003) against, respectively, Staphylococcus aureus and Aspergillus niger with an inhibition zone of 9.33 mm. The phenolic extract had the largest spectrum of sensitive microorganisms. The minimum inhibitory concentration and minimum bactericidal concentration results showed that all strains were inhibited by both oil and extract

Effect of growing area on tocopherols, carotenoids and fatty acid composition of Pistacia lentiscus edible oil

International audienceIn this investigation, we aim to study, for the first time, the effect of the growing area on tocopherols, carotenoids and fatty acid content of Pistacia lentiscus fixed oil. Fruits were harvested from eight different sites located in the north and the centre of Tunisia. Tocopherols, carotenoids and fatty acid content of the fixed oils were determined. The highest carotenoid content was exhibited by Feija oil (10.57 mg/kg of oil). Oueslatia and Tabarka oils displayed the highest alpha-tocopherol content (96.79 and 92.79 mg/kg of oil, respectively). Three major fatty acids were determined: oleic, palmitic and linoleic acids. Oleic acid was the main fatty acid presenting more than 50% of the total fatty acid content. Kebouche oil presented the highest oleic acid content (55.66%). All these results highlight the richness of carotenoids, tocopherols and unsaturated fatty acids in P. lentiscus seed oil and underscore the nutritional value of this natural product

A unilocular thymic cyst associated with true thymic hyperplasia: a challenging diagnosis especially in a child

Mona Mlika,1,2 Walid Gattoufi,1,2 Hazem Zribi,2 Emna Braham,1,2 Adel Marghli,2 Faouzi El Mezni1,21Department of Pathology, Abderrahman Mami Hospital, Tunis, Tunisia; 2Research Unit UR12SP16, Universit&eacute; Tunis El Manar, Facult&eacute; de M&eacute;decine de Tunis, Tunis El Manar, TunisiaAbstract: We report a new case of a mediastinal mass in a 19-year-old patient corresponding microscopically to an association of unilocular thymic cyst and true thymic hyperplasia. Our aim is to highlight the absence of specificity of clinical and radiological findings and the necessity of a thorough sampling of the tumor in order to establish the diagnosis.Keywords: true thymic hyperplasia, thymic cyst, microscopy, surger

Analyse à l'échelle microstructurale de la fissuration dans une roche argileuse anisotrope par mesure de champs 2D et 3D

International audienceDans cette étude, la fissuration d'un échantillon millimétrique de roche argileuse soumis à un chargement mécanique de compression uni-axiale a été observée dans un premier temps par microscopie optique, donnant accès à une analyse fine de l'initiation et de la propagation. Dans un second temps, des essais similaires sont observés par tomographie RX synchrotron, avec une résolution proche de la microscopie optique, rendant compte ainsi de façon comparable du comportement en volume. L'influence de l'anisotropie du matériau est clairement mise en évidence avec les expériences 2D. L'analyse volumique montre l'évolution du champ de déformation dans l'éprouvette, avec des localisations très caractéristiques de ce type d'essai