Clinical and seroepidemiological study of Leishmaniasis in Northern Morocco

Une étude clinique, parasitologique et sérologique entreprise de 1993 à 1996 dans trois régions (17 localités) du nord du Maroc a révélé une fréquence élevée de la leishmaniose canine. 1362 chiens ont été examinés. Les sérums ont été collectés et testés selon la technique ELISA utilisant la souche locale Leishmania infantum comme antigène. Les résultats obtenus ont révélé une séroprévalence (quand elle n’est pas nulle) allant de 3,77% à 35,7%. Six isolats ont été caractérisés : 5L eishmania infantum ont été identifiés dans les provinces de Khémisset et Taza et une souche Leishmania tropica isolé d’un cas leishmanien dans la province de Taounate. La majorité des chiens cliniquement suspects ont montré des lésions ulcératives de la peau, amaigrissement, onychogriffose et lymphadenopathie. L’alopécie, la cécité et la diarrhée ont été observés uniquement dans la province de Khémisset

Investigating The Inhibition Of 5-LO Enzyme By Main Cannabinoids Contained In Cannabis Sativa And Seized Resin Cannabis By Using Molecular Modeling

Therapeutic cannabis is a subject which many researchers are very interested in all over the world. The effect of main compound of Cannabis is investigated to treat many diseases. Arachidonate 5-lypoxygenase (5-LO) is implicated in cancer progression, inflammation, tissue damage and other sickness. Commonly to inhibit 5-LO enzyme a famous drug Zileuton is used. In our work we compare inhibition of 5-LO by main compounds of cannabis using tools such as molecular mechanics, molecular dynamics and molecular docking by using MOE software (Molecular Operating Environment) [1]. Obtained results show that main cannabinoids inhibit 5- LO better than Zileuton

π-d Effect in complexation between copper(II) ions and L,L-dipeptides containing aromatic side-chains

The L,L-Phe-Leu-Cu(II), L,L-Leu-Phe-Cu(n) and Gly-L-Phe-Cu(II) systems were studied using potentiometric, calorimetric and spectroscopic measurements. The results obtained from potentiometric and calorimetric studies show a significant increase in stability of copper complexes, when an aromatic residue is located in C-terminal, compared to the L,L-dipeptides containg the same amino acid residues, but in which the phenyl group is N-terminal. This stability increase is suggested as the result of interaction between π-electrons of the aromatic ring and the d-orbitals of the metal ion. An IR spectroscopic study was also carried out for the L,L-Leu-Phe-Cu(II) and Gly-L-Phe-Cu(II) systems

Potentiometric and spectroscopic study of the complexation of copper(II) ions by tripeptides containing aromatic side-chains

The complexation of copper(II) ions with L,L-Gly-Phe-Phe, L,L-Phe-Gly-Phe and L,L-Phe-Phe-Gly was studied by potentiometric and spectroscopic measurements. Only four complexes have been found for each copper(II)-tripeptide system, and no species with two ligand molecules was observed. The results show influences of aromatic side-chains. These influences are dependent upon the location of two aromatic rings in studied tripeptides. The stabilization or destabilization of a given complex is probably the result of several different effects, including steric hindrance, hydrophobic effect, electrodonor effect and π-d interaction. The spectroscopic measurements, e.s.r and electronic absorption, are useful to determine the complex structures

Prediction of thermal conductivity of liquid and vapor refrigerants for pure and their binary, ternary mixtures using artificial neural network

International audienceThe determination of thermophysical properties of hydrofluorocarbons (HFCS) is very important, especially the thermal conductivity. The present work investigated the potential of an artificial neural network (ANN) model to correlate the thermal conductivity of (HFCS) at (169.87-533.02) K, (0.047-68.201) MPa, and (0.0089-0.1984) W/(m·K) temperature, pressure, and thermal conductivity ranges, respectively, of 11 systems from 3 different categories including five pure systems (R32, R125, R134a, R152a, R143a), four binary mixtures systems (R32 + R125, R32 + R134a, R125 + R134a, R125 + R143a), and two ternary mixtures systems (R32 + R125 + R134a, R125 + R134a + R143a). Each one received 1817, 794 and 616 data points, respectively. The application of this model for these 3227 data points of liquid and vapor at several temperatures and pressures allowed to train, validate and test the model. This study showed that ANN models represent a good alternative to estimate the thermal conductivity of different refrigerant systems with a good accuracy. The squared correlation coefficients of thermal conductivity predicted by ANN were R2 = 0.998 with an acceptable level of accuracy of RMSE = 0.0035 and AAD = 0.002 %. The results of applying the trained neural network model to the test data indicate that the method has a highly significant prediction capability

Potentiometric studies and modelization of ternary complexes of nickel(II) with a tetradentate Schiff-base and its reduced form as the primary ligand and methionine and cysteine as the secondary one.

International audienceThe stability constants of binary and ternary complexes of nickel(II) with two tetradentate ligands: bis(2-hydroxyacetophenone) ethylenediamine (H2BS) and N,N´-bis(2-hydroxyacetophenyl)-1,2-diaminoethane (H2BSR) as primary ligands and two amino acids: methionine (Met) and cysteine (Cys) as secondary ones, were determined by potentiometric measurements at constant temperature (25.0 ± 0.1ºC) and ionic strength (0.2 mol L-1, NaCl) in water-ethanol (90 : 10 w/w) medium. Two species are formed for which the molar ratio of metal to BS or BSR and Met or Cys are 1 : 1 : 1 and 1 : 1 : 2. The binary and ternary complexes of BSR are more stable than those of BS. The values of D log K constant show that ternary complexes have a higher stability than the corresponding binary ones in the case of methionine but not for cysteine. The geometry of all the species formed have been optimized by molecular mechanics using the EMO program. It was found that there is a direct correlation between the stability constants of the ternary complexes and their steric energy

Adsorptive removal of amoxicillin from wastewater using wheat grains: equilibrium, kinetic, thermodynamic studies and mass transfer

International audienceWheat grains are natural products which grow in the north of Algeria. In this study, they were used as adsorbent to remove amoxicillin antibiotic from wastewater. Adsorption isotherm of amoxicillin on both crude and modified wheat grains with 20% tartaric acid was investigated in batch tests. A model was developed regarding both the kinetic partitioning and the mechanism governing the forward transfer of amoxicillin. Results were interpreted in terms of a two-film theory for flat interface. The percentage of maximum adsorption capacity of amoxicillin was found to be 84% for the following optimal conditions: amoxicillin concentration of 4 mg/L, 5 min contact time, pH 7, temperature 25°C, and 0.24 g/L initial amoxicillin concentration and 150 μg particle size. The pseudo-first-order, pseudo-second-order kinetic models and the intraparticle diffusion model were used to describe the kinetic data, and the rate constants were evaluated. It was found that the pseudo-second-order model provides the most adequate correlation of experimental data. The rate parameters of the intraparticle diffusion model for adsorption were also evaluated and to identify the adsorption mechanisms. The adsorption constants were evaluated by using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) adsorption isotherm models. The results showed that Temkin isotherm agrees with experimental data better than other adsorption models for the adsorption of amoxicillin. The thermodynamic parameters (ΔG, ΔH, and ΔS) showed that the process was feasible, spontaneous, and exothermic. © 2016 Balaban Desalination Publications. All rights reserved