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Chemical composition and antimicrobial activity of Satureja, Thymus, and Thymbra species grown in Lebanon
No full textInternational audienceThe essential oils were extracted by hydrodistillation from Satureja cuneifolia, Satureja thymbra, Coridothymus capitatus, Thymus syriacus, and Thymbra spicata growing wild in Lebanon. Their phytochemical analysis performed by GC/MS showed that the aforementioned species are characterized either by carvacrol (60.9%) or thymol (54.3%) or by a more or less equal amounts of these two phenols. Assessment of their in vitro antimicrobial activity against Candida albicans and six pathogenic bacteria using the broth dilution method revealed that the tested oils have a broad activity spectrum with minimum inhibitory concentration ranging from 0.1 to 0.8 mg/ml. Among the tested species, S. thymbra EO showed the highest antimicrobial potential whereas T. syriacus showed the lowest inhibitory activity. These results give scientific evidence for the use of those species in the Lebanese folk medicine and lend support to implement them as natural alternatives for synthetic antimicrobials
Analysis of the impact of fining agents types, oenological tannins and mannoproteins and their concentrations on the phenolic composition of red wine
No full textInternational audienceThis paper aimed to evaluate and analyze the effect of five fining agents, commercial tannins and mannoproteins on the pigment, color and tannins composition of a Cabernet Sauvignon red wine. The wines were analyzed 2 d after treatment and immediately after separation of sedimentation. Color was evaluated by spectrophotometry and polyphenols were analyzed by spectrophotometry and HPLC-DAD. The results showed that all treatments affected the phenolic contents of the wine. The most remarkable effects on phenolic composition were produced by bentonite and Polyvinylpolypyrrolidone (PvPP) + potassium caseinate which significantly decreased anthocyanins and tannins concentrations, respectively. The use of vegetable protein and gelatin has a less impact on the color and phenolic contents of red wines. The antioxidant activity was little affected by treatments except the addition of tannins that increased it. Principal components analysis demonstrates the importance of a low concentration of agents for high total polyphenol levels
Etude de l’effet du sur-éclairement non uniforme sur les performances d’une installation photovoltaïque équipée de réflecteurs plans
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De l’emprise de l’inconscient dans les organisations : Voyage en complexité interpersonnelle
No full textInternational audienceÀ travers cet article, les auteurs se proposent de mobiliser une grille de lecture originale pour aborder la complexité dans les organisations : l’approche psychanalytique. Ce choix n’est pas neutre. En effet, alors qu’habituellement, les grilles de lecture mobilisées s’inscrivent dans une logique paradigmatique fondée sur la conscience, il s’agit ici de mettre en avant une grille de lecture permettant de prendre en considération l’inconscient. L’objectif n’est pas de se positionner de façon dichotomique, conscient vs inconscient, mais bien de montrer la possible saisie simultanée et dialogique de ces deux aspects, laquelle permet d’aborder la complexité humaine
The nitridoborate nitrides Mg3[BN2]N and Ca3[BN2]N – electronic structure and chemical bonding
No full textInternational audienceThe nitridoborates Mg3[BN2]N (P63/mmc) and Ca3[BN2]N (P4/mmm) are electron-precise compounds with discrete linear [BN2]3− and isolated N3− anions. Electronic structure calculations reveal pronounced B–N bonding within the [BN2]3− units with more covalent Mg–N vs. Ca–N bonding. Total energy calculation for hexagonal normal-pressure Mg3[BN2]N, orthorhombic high-pressure Mg3[BN2]N and a hypothetical Ca3[BN2]N-type tetragonal Mg3[BN2]N modification revealed that the hexagonal modification is the ground state structure. The band structure for orthorhombic high-pressure Mg3[BN2]N indicates a substantial metallization (delocalization in the high-pressure regime). This peculiar result calls for a reinvestigation of high-pressure Mg3[BN2]N under different high-pressure high-temperature conditions along with physical property studies
An Unusual Presentation of a Primaryeosinophilic Gastrointestinal Disorder (Case Report)
No full textInternational audiencePrimary Eosinophilic gastroenteritis is an uncommon inflammatory gastrointestinal disease affecting children first described in 1937.Its incidence is 1/100000. The eosinophilic infiltration can occur in one or more segments of the gastrointestinal tract especially stomach and duodenum in the absence of known etiology. One or more layers are infiltrated by eosinophils. The clinical manifestations are heterogeneous. Its pathogenesis is not fully understood but food hypersensitivity is considered a major factor. Treatments are mostly unsatisfactory, and prognosis is uncertain. No guidelines up to this date have been published regarding the management of these patients.We report the case of a premature twin boy who was admitted to the –Neonatal Intensive Care Unit-NICU for suspected sepsis.Our purpose is to highlight the importance of multidisciplinary team approach for management of unusual neonatal cases where sub-specialized workup and skills are a must for early diagnosis and clinical success. Our case is peculiar because of the young age of presentation and the scarce gastrointestinal symptoms at presentation that swayed us towards a hematologic or infectious disorder which are the likely diagnoses at this age
Utiliser des systèmes de transport intelligents pour améliorer la sécurité des piétons au carrefour signalisé de Beyrouth
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Waterfilling-based Proportional Fairness Scheduler for Downlink Non-Orthogonal Multiple Access
No full textInternational audienceIn this letter, a low-complexity waterfilling-based Power Allocation (PA) technique, incorporated within the Proportional Fairness (PF) scheduler, is proposed and applied to a Non-Orthogonal Multiple Access (NOMA) scheme in a cellular down-link system. The aim of the proposed joint PA and scheduling scheme is to maximize the achieved average throughput through a quasi-optimal repartition of the transmit power among subbands, while guaranteeing a high level of fairness in resource allocation. Extensive simulation results show that the proposed technique enhances both system capacity and user fairness, when compared to either orthogonal signaling (OS) or NOMA with static PA
DFT study of isomers of the ruthenium dihydride complex RuH2(CO)2(AsMe2Ph)2
No full textInternational audienceA density functional theory (DFT) study of cct-As, ccc, and cct-CO isomers of the ruthenium dihydride complex RuH2(CO)(2)(AsMe2Ph)(2) is reported (see Scheme for the labeling isomer 34 structures of RuH2(CO)(2)(AsMe2Ph)(2)). Complex geometries and relative energies of different isomers have been calculated with both B3LYP and M06-2X functionals. The results show that the B3LYP calculated Boltzmann populations of cct-As, ccc, and cct-CO isomers are 65.5, 34.2, and 0.3%, respectively. These are in better agreement with the experimental data than those calculated at the M06-2X level. However, the calculations of H-1 NMR chemical shifts were found to be better described with M06-2X than with B3LYP or with HF level of theories. In addition, a transition state between the two most stable isomers was determined through DFT/(B3LYP or M06-2X) calculations
