Anisotropy of the gap energy in high Tc Copper Oxides

Within the frame work of BCS phonon-mediated pairing with a logarithmic (2D) Van Hove Singularity in the density of states, we study the anisotropy of superconductors gap taking into account the anisotropy of attractive coupling and the coulomb repulsion .The results show that gap is more disperse and can explain some observed experimental data.Within the frame work of BCS phonon-mediated pairing with a logarithmic (2D) Van Hove Singularity in the density of states, we study the anisotropy of superconductors gap taking into account the anisotropy of attractive coupling and the coulomb repulsion .The results show that gap is more disperse and can explain some observed experimental data

Composition chimique et propriétés antimicrobiennes de l’huile essentielle extraite des feuilles de Tetraclinis articulata (Vahl) du Maroc

Chemical composition and antimicrobial properties of essential oil of theMorroccan Tetraclinis articulata leavesThe yield, chemical composition and antimicrobial properties of the essential oil extracted from Tetraclinis articulata (Vahl) leaves growing in Khemisset (Morocco) were studied. The essential oils yield average is 0,22 %. Thirty four components were identified by GC and GC/MS ; bornyl acetate (30,74 %), á-pinene (23,54 %), camphor (17,27 %) and limonene (23,31 %) are the principal components of this oil. A strong inhibited activity against six microorganisms is obtained

The effect of confined Longitudinal Optical Phonons on the Binding Energy of an impurity in CdSe Quantum Dot

Using a variational approach, the effect of the confined LO-phonon on the binding energy in CdSe Quantum Dot has been calculated. The charge-carrier-phonon coupling is treated within the adiabatic approximation. Our results show that the effect of the confined LO-phonon on the binding energy decreases with the dot size. However the correction of the confined LO-phonon to bound state energy increases with dot size.Using a variational approach, the effect of the confined LO-phonon on the binding energy in CdSe Quantum Dot has been calculated. The charge-carrier-phonon coupling is treated within the adiabatic approximation. Our results show that the effect of the confined LO-phonon on the binding energy decreases with the dot size. However the correction of the confined LO-phonon to bound state energy increases with dot size

Dégradation photochimique d'herbicides chlorophenoxyalcanoïques en milieux aqueux

La dégradation photochimique de cinq herbicides appartenant à la famille des chlorophénoxyalcanoïques a été étudiée en solution aqueuse par irradiation à 254 nm selon trois systèmes : UV seul, UV/H2O2 et UV/H2O2/ FeIII (photo-Fenton). Le procédé photochimique semble constituer une alternative prometteuse aux méthodes existantes de traitement chimique des eaux polluées; en effet il permet de détruire photochimiquement l'herbicide initial et d'obtenir, dans les conditions opératoires initiales, sa minéralisation complète en CO2 et H2O. Il s'agit d'un procédé d'oxydation avancé, utilisant comme agent oxydant, des radicaux OH. produits in situ photochimiquement. L'évolution de la composition chimique des solutions d'herbicides étudiés a été suivie par chromatographie liquide à haute performance (CLHP). La minéralisation a été évaluée par mesure de la demande chimique en oxygène (DCO) et par le dosage des ions chlorures libérés. La cinétique de photodégradation, la nature et l'évolution des produits formés ainsi que le rendement du procédé ont été déterminés.Contamination of surface and ground waters by persistent organic pollutants constitutes a serious environmental problem. A number of physical and biological methods have been proposed to remove these pollutants from industrial wastewater. However, many organic contaminants are not destroyed by these techniques. Various chemical treatment methods for polluted waters have been proposed. These methods are based on catalytic, electrochemical and photochemical reactions, known as advanced oxidation processes (AOPs). However, despite these treatments, there is presently no universal technique available. Because of their widespread agricultural use, chlorophenoxyacid herbicides contaminate waterways and ground waters in France and many other European countries.In the present study, we have investigated the photochemical degradation of several chlorophenoxyacids in aqueous solution at room temperature, by ultraviolet (UV) irradiation at 254 nm. We compared the efficiency of three different systems: UV alone; assisted photochemistry (UV/H2O2); and photo-Fenton reaction (UV/H2O2/FeIII). The latter photochemical system was found to represent a promising alternative approach, relative to existing methods of polluted water chemical treatment. The method photochemically destroyed the initial herbicides into CO2 and H2O. Also, it constitutes an AOP based on the in situ photochemical formation of OH· radicals. The evolution of the chemical composition of the herbicide samples studied was monitored by high performance liquid chromatography (HPLC). The mineralization of the initial herbicides was evaluated by the measurement of the chemical oxygen demand (COD) and the determination of chloride ions. The photodegradation kinetics, the nature and evolution of the photoproducts as well as the process yield were studied for the three photochemical systems for five different chlorophenoxyacid herbicides, including 2-(2-methyl-4-chlorophenoxy)propionic acid (MCPP), 4-chloro-2-methylphenoxyacetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), 2-(2,4-dichlorophenoxy)propionic acid (2,4-DP) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).Photodegradation by UV alone was relatively slow and partial, taking place in 1 h for MCPA, 1.5 h for MCPP and 3 h for 2,4-D. This process did not completely destroy the photoproducts. The mineralization yields for the organic matter were 64 %, for MCPA, 69 % for MCPP, 42 % for 2,4-DP and 35 % for 2,4-D, following an irradiation time of 2 h. The technique based on the photolysis of hydrogen peroxide (UV/H2O2) produced a more rapid photodecomposition, occurring within about 30 min for MCPA and MCPP and more than 60 min for 2,4-D and 2,4,5-T. The corresponding mineralization yields for the organic matter were 79 % for MCPP and 2,4-DP and 56 % for 2,4-D. The absolute rate constants for the reaction with hydroxyl radicals were found to be1.5×109, 1.6×109, 3.2×109 and 3.6×109 M-1 s-1 respectively for 2,4,5-T, 2,4-DP, MCPP and MCPA using this technique.The photo-Fenton system significantly improved the kinetic performance and mineralization yield. The photodegradation times were 7 min for MCPA, 10 min for MCPP, 40 min for 2,4-D and 60 min for 2,4,5-T, whereas the mineralization yields reach respective values of 96 % for MCPP, 95 % for MCPA, 80 % for 2,4-D, 94 % for 2,4-DP and 89 % for 2,4,5-T

Demographics and outcomes of hepatitis B and D: A 10-year retrospective analysis in a Swiss tertiary referral center.

Hepatitis B virus (HBV) is a major global health challenge with approximately 250-350 million chronically infected individuals. An improved understanding of the demographic features and outcomes of chronic HBV infection and hepatitis D virus (HDV) infection in low-endemic areas may improve prevention, early identification and management both at individual and community levels. Here, we retrospectively analyzed the demographic and clinical characteristics, treatment rates and outcomes of adult patients with chronic HBV infection with or without HDV coinfection examined at Lausanne University Hospital, Switzerland over a 10-year period. We analyzed the medical records of all adult patients with chronic HBV and HDV infection examined in our center between 2007 and 2016. Liver-related outcome was defined as the occurrence of cirrhosis, hepatocellular carcinoma, liver transplantation or liver-related death. Analyses were performed using logistic regression and results were reported as odds ratio (OR) and 95% confidence interval (CI). Of 672 consecutive patients, 421 (62.6%) were male, median age was 36 years (interquartile range, 28-46 years), and 233 (34.7%) were of African origin. The prevalence of HDV coinfection was 7.1% and the proportion of anti-HDV-positive patients with detectable HDV RNA was 70.0%. In multivariate analysis, HDV coinfection was the strongest predictor for liver-related outcome (OR 6.06, 95% CI 2.93-12.54, p<0.001), followed by HBeAg positivity (OR 2.47, 95% CI 1.30-4.69, p = 0.006), age (OR per 10-year increase 2.03, 95% CI 1.63-2.52, p<0.001) and sex (OR for female 0.39, 95% CI 0.22-0.71, p = 0.002). The predictive accuracy of the multivariate model was high (receiver operator characteristic area under the curve 0.81). This retrospective study underscores the importance of migration in the epidemiology of chronic hepatitis B in low-endemic areas. HDV coinfection, HBeAg positivity and age predicted liver-related outcomes while female sex had a protective effect

Postendovascular thoracic aortic repair subclavian steal syndrome revealed by severe headache

AbstractSubclavian steal syndrome (SCSS) has been known since 1960 in the medical literature. Its principal cause is atherosclerosis responsible of occlusion of the subclavian artery (SCA). It is the pathological process in which blood flows in reverse direction from the vertebral artery (VA) to the SCA. Usually asymptomatic, but a variety of symptoms may develop involving the vertebro-basilar and/or the carotid territories and may be precipitated by exercise of the upper extremity. In some circumstances it can be iatrogenic complicating the course of a thoracic endovascular aortic repair (TEVAR) when the left SCA is covered by the endoprosthesis, which is a necessity many times giving the frequent proximity of the acute thoracic pathologies to the origin of this vessel.We present a case of severe headache occurring after a TEVAR with intentional coverage of the origin of the left SCA. This headache was the only symptom from which the patient complained, and which disappeared immediately after carotid-SCA bypass. Other devastating complications can happen, which gave as a concern about the management of SCA when decision to practice a TEVAR is taken

Étude phytochimique et évaluation de l’activité anti-oxydante de Thymus CIliatus ssp. Coloratus

Thymus ciliatus ssp. Coloratus, plante aromatique, spontanée et répandue en régions méditerranéennes et dans le nord de l’Algérie est très utilisée par les populations locales pour ses vertus médicinales. Les tests phytochimiques appliqués au Thymus ciliatus ssp coloratus ont montré la présence de quelques familles de composés chimiques et notamment les flavonoïdes. L'activité antioxydante in vitro de l’extrait de flavonoïdes a été évaluée par la technique de réduction du fer « FRAP » (ferric reducing antioxydant power) et par le test de DPPH. La première méthode a montré que la fraction acétate d’éthyle de la partie aérienne a une capacité à réduire le fer plus marquée que celles de l’acide ascorbique et le BHA et que celle des racines, est nettement inférieure. Quant aux fractions butanoliques des flavonoïdes de la partie aérienne et des racines, elles ont une capacité à réduire le fer largement inférieure à celles de l’acide ascorbique et le BHA. L’activité antioxydante, obtenue par la second procédé et relative à la fraction acétate d’éthyle des flavonoïdes de la partie aérienne de la plante est plus importante (I.C₅₀=0,85 mg/mL) que celles obtenues à partir d’antioxydants utilisés dans les industries alimentaire et pharmaceutique en l’occurrence l’acide ascorbique (I.C₅₀ = 1,12 mg/mL) et le BHA (I.C₅₀=1,61 mg/mL).Mots-clés : Thymus coloratus, activité antioxydant, flavonoïde, FRAP, DPPH.Phytochemical study and evaluation of the antioxidant activity of thymus ciliatus ssp. Coloratus Thymus ciliatus ssp. coloratus, aromatic plant, spontaneous and widespread in the Mediterranean and in northern Algeria is widely used by local people for its medicinal properties. Phytochemical tests applied for Thymus sciliatus ssp coloratus showed the presence of several families of chemical compounds including flavonoïds. The in vitro antioxidant activity of flavonoïds extract was evaluated by the iron reduction technique "FRAP" (ferric reducing antioxidant power) and DPPH test. The first method showed that the ethyl acetate fraction of the aerial part has an ability to reduce the iron greater than ascorbic acid and BHA and the roots, is significantly lower. As for butanol fractions of flavonoïds from the aerial part and roots, they have an ability to reduce iron significantly lower than those of ascorbic acid and BHA. The antioxidant activity obtained by the second method and on the ethyl acetate fraction of flavonoïds from the aerial part of the plant is more important (I.C₅₀ = 0.85 mg / mL) than those obtained from 'antioxidants used in food and pharmaceutical industries namely ascorbic acid (I.C₅₀ = 1.12 mg / mL) and BHA (I.C₅₀ = 1.61 mg / mL).Keywords : Thymus coloratus, antioxidant activity, flavonoïd, FRAP, DPPH

Perioperative Course and Socioeconomic Status Predict Long-Term Neurodevelopment Better Than Perioperative Conventional Neuroimaging in Children with Congenital Heart Disease.

The objective of the study was to compare the use of neonatal conventional brain magnetic resonance imaging (MRI) with that of clinical factors and socioeconomic status (SES) to predict long-term neurodevelopment in children with severe congenital heart disease (CHD). In this prospective cohort study, perioperative MRIs were acquired in 57 term-born infants with CHD undergoing cardiopulmonary bypass surgery during their first year of life. Total brain volume (TBV) was measured using an automated method. Brain injury severity (BIS) was assessed by an established scoring system. The neurodevelopmental outcome was assessed at 6 years using standardized test batteries. A multiple linear regression model was used for cognitive and motor outcomes with postoperative TBV, perioperative BIS, CHD complexity, length of hospital stay, and SES as covariates. CHD diagnoses included univentricular heart defect (n = 15), transposition of the great arteries (n = 33), and acyanotic CHD (n = 9). Perioperative moderate-to-severe brain injury was detected in 15 (26%) patients. The total IQ was similar to test norms (P = .11), whereas the total motor score (P < .001) was lower. Neither postoperative TBV nor perioperative BIS predicted the total IQ, but SES (P < .001) and longer hospital stay (P = .004) did. No factor predicted the motor outcome. Although the predictive value of neonatal conventional MRIs for long-term neurodevelopment is low, duration of hospital stay and SES better predict the outcome in this CHD sample. These findings should be considered in initiating early therapeutic support