Antimycobacterial, antioxidant and cytotoxic activities of essential oil of gall of Pistacia atlantica Desf. From Algeria

Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria.Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium fortuitum. Antioxidant activity was determined using free-radical scavenging assays. The safety of essential oil was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on C3A and Vero monkey kidney cells.Results: The minimal inhibitory concentration (MIC) values ranged from 0.16 to 2.5 mg/mL with minimal bactericidal concentration (MBC) values ranged from 0.62 to >2.5 mg/mL. The antioxidant activity showed IC50 values ranged between 417.61 - >2000μg/mL and 495.6 - >2000μg/mL for DPPH and ABTS assay respectively. The cytotoxicity assay showed LC50 ranged between 26.47 to 93.64 μg/mL against Vero cells and 74.29 to 225.40 μg/mL against C3A. The results of this study show that the essential oils from the gall of P. atlantica have low toxicity and moderate activity against fast growing M. smegmatis and M. aurum.Conclusion: These results substantiate their potential as used in the treatment of non-tuberculous mycobacterial infections. This finding is predictive of their activity against M. tuberculosis, therefore, further study might be considered to investigate the activity against pathogenic Mycobacterium strains.Key words: Pistacia atlantica, Essential oil, Antimycobacterial, Antioxidant, Cytotoxicity

OLAP Textual Aggregation Approach using the Google Similarity Distance

International audienceData warehousing and On-Line Analytical Processing (OLAP) are essential elements to decision support. In the case of textual data, decision support requires new tools, mainly textual aggregation functions, for better and faster high level analysis and decision making. Such tools will provide textual measures to users who wish to analyse documents online. In this paper, we propose a new aggregation function for textual data in an OLAP context based on the K-means method. This approach will highlight aggregates semantically richer than those provided by classical OLAP operators. The distance used in K-means is replaced by the Google similarity distance which takes into account the semantic similarity of keywords for their aggregation. The performance of our approach is analyzed and compared to other methods such as Topkeywords, TOPIC, TuBE and BienCube. The experimental study shows that our approach achieves better performances in terms of recall, precision,F-measure complexity and runtime

Molecular Dynamics Simulation Study of Organic Solvents Confined in PIM-1 and P84 Polyimide Membranes

International audienceOrganic solvent nanofiltration (OSN) has recently proved to be a promising separation process thanks to the development of membrane materials with suitable resistance toward organic solvents. Among those materials, P84 polyimide membranes are currently the most used in OSN while PIM-1 membranes have recently attracted attention due to their high permeance in apolar solvents and alcohols. Both P84 and PIM-1 membranes have nanosized free volumes, and their separation performance is finely connected to polymer/solvent interactions. Consequently, modeling OSN membranes at the molecular scale is highly desirable in order to rationalize experimental observations and gain a deeper insight into the molecular mechanisms ruling solvent and solute permeation. A prerequisite for understanding solvent transport through OSN membranes is therefore to characterize the membrane/solvent interactions at the molecular level. For that purpose, we carried out molecular simulations of three different solvents, acetone, methanol, and toluene in contact with P84 and PIM-1 membranes. The solvent uptake by both membranes was found to be correlated to the degree of confinement of the solvent, the polymer swelling ability and polymer/solvent interactions. The translational dynamics of the solvent molecules in the PIM-1 membrane was found to be correlated with the solvent viscosity due to the relatively large pores of this membrane. That was not the case with the P84 membrane, which has a much denser structure than the PIM-1 membrane and for which it was observed that the translational dynamics of the confined solvent molecules was directly correlated to the affinity between the P84 polymer and the solvent

Interactions between methanol/toluene binary mixtures and an organic solvent nanofiltration PIM-1 membrane

International audienceIn this work, a molecular scale study of the interactions between a polymer with intrinsic microporosity (PIM-1) membrane and toluene, methanol and their mixtures was performed by means of molecular dynamics simulations. From the radial distribution functions we highlight specific interactions between the hydroxyl group of methanol and the aromatic ring of toluene as well as with the PIM-1 membrane. Moreover, the presence of nitrogen atoms on the PIM-1 backbone makes it possible the formation of hydrogen bonds like interaction (close contact of 2.5 Å) between the methanol molecules and the PIM-1 membrane, thus leading to interfacial anchoring of methanol at the polymer surface and moving toluene molecules away from the surface. However some toluene molecules are located around 3.5 Å due to π-stacking interaction between the aromatic rings of the PIM-1 membrane and those of the confined TOL molecules. At short range, the confined methanol molecules interact with each other like their bulk-phase counterparts whereas long range correlations highlight a existence of confined methanol aggregates. The specific interactions between toluene, methanol and the PIM-1 membrane result in a linear increase of the membrane swelling with the mole fraction of toluene in the binary mixtures. © 2022 Elsevier B.V

Le Bayoud du palmier dattier : une maladie qui menace la phoeniciculture

La phoeniciculture est largement développée en Afrique du Nord et au Moyen Orient où le palmier dattier est l'élément structurant des oasis dans les régions désertiques. Plusieurs millions d'arbres ont été détruits dans les palmeraies marocaines et algériennes par une fusariose vasculaire, le Bayoud. Ce sont des mesures phytosanitaires strictes qui ont, jusqu'à ce jour, permis d'éviter l'extension de la maladie aux autres pays phoenicicoles. Les recherches, engagées depuis plus de 20 ans pour la sélection de variétés résistantes productrices de dattes de bonne qualité, sont en voie d'aboutir. La caractérisation moléculaire de #Fusarium oxysporum f. sp. #albedinis, responsable du Bayoud, a montré que les populations du champignon, en Algérie et au Maroc, sont peu diversifiées et semblent avoir une même origine clonale. Dans un proche avenir, les méthodes moléculaires pourront sans doute permettre d'identifier rapidement le parasite dans le sol et dans le matériel végétal. (Résumé d'auteur

Le Bayoud du palmier dattier : une maladie qui menace la phoeniciculture

La phoeniciculture est largement développée en Afrique du Nord et au Moyen Orient où le palmier dattier est l'élément structurant des oasis dans les régions désertiques. Plusieurs millions d'arbres ont été détruits dans les palmeraies marocaines et algériennes par une fusariose vasculaire, le Bayoud. Ce sont des mesures phytosanitaires strictes qui ont, jusqu'à ce jour, permis d'éviter l'extension de la maladie aux autres pays phoenicicoles. Les recherches, engagées depuis plus de 20 ans pour la sélection de variétés résistantes productrices de dattes de bonne qualité, sont en voie d'aboutir. La caractérisation moléculaire de #Fusarium oxysporum f. sp. #albedinis, responsable du Bayoud, a montré que les populations du champignon, en Algérie et au Maroc, sont peu diversifiées et semblent avoir une même origine clonale. Dans un proche avenir, les méthodes moléculaires pourront sans doute permettre d'identifier rapidement le parasite dans le sol et dans le matériel végétal. (Résumé d'auteur