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Al Marsá, Tunisia

Bouyer F.,French Institute of Health and Medical Research | Moretto J.,French Institute of Health and Medical Research | Pertuit D.,Unite de Molecules dInteret Biologique | Szollosi A.,Unite de Molecules dInteret Biologique | And 4 more authors.
Journal of Inorganic Biochemistry | Year: 2012

In order to improve the pharmacological profile of the anticancer drug cisplatin, several new acridine-based tethered (ethane-1,2-diamine)platinum(II) complexes connected by a polymethylene chain were synthetized. Activity-structure relationship between amide or ester functionalities was explored by changing acridine-9-carboxamide into acridine-9-carboxylate chromophore. The in vitro cytotoxicity of these new complexes was assessed in human colic HCT 116, SW480 and HT-29 cancer cell lines. Series of complexes bearing the acridine-9-carboxylate chromophore displayed higher cytotoxic effect than acridine-9-carboxamide complexes, with gradual effect according to the size of the polymethylene linker. © 2012 Elsevier Inc. All rights reserved.

Laiarinandrasana L.,MINES ParisTech Center of materials | Devilliers C.,MINES ParisTech Center of materials | Devilliers C.,Veolia | Oberti S.,Veolia | And 3 more authors.
International Journal of Pressure Vessels and Piping | Year: 2011

In order to characterize the mechanical behavior of HDPE pipes, the ASTM D 2290-04 standard recommends carrying out tensile tests on notched rings, cut out from the pipe. This very simple test is also utilized to investigate the aging effect of the pipe by determining the strain at failure. Comparison between full ring and notched ring mechanical responses are discussed. Constitutive modeling including strain rate effects was performed by finite element analysis. This allowed a better understanding of the stress state in the cross section perpendicular to the loading direction. Additionally, the influence of a thin layer of oxidized HDPE in the inner wall of the ring was studied in the light of the finite element results. © 2010 Elsevier Ltd.

Saghrouni H.,University of Sousse | Hannachi R.,University of Sousse | Jomni S.,Laboratoire Materiaux | Beji L.,University of Sousse
Physica B: Condensed Matter | Year: 2013

The electrical properties of Au/n+-GaAs and Au/n-porous GaAs metal-semiconductor structures were investigated using room temperature current-voltage I(V) and capacitance-voltage C(V) measurements. The electrical parameters of these structures such as ideality factor, barrier height potential, series resistance have been calculated. The obtained parameters of Au/n-porous GaAs structure were discussed and compared to those of Au/n +-GaAs structure. The series resistances and ideality factors of the two structures were seen to have approximately the same values. Furthermore, the shunt resistance and the barrier height potential values for the Au/n-porous GaAs structure were found to be different than the ones of Au/n+-GaAs structure. Furthermore the two structures showed a non-ideal I(V) behavior with an ideality factor greater than unity. Such non ideal behavior was suggested to be due to the existence of high density of trap and the forward I(V) characteristics which were governed by space charge limited conductivity, characterized by single and exponential trapping levels in both structures (SCLC). A model based upon TFE tunneling of carriers at reverse current was used to explain the non-saturation of reverse current of the structures. The high frequency C(V) characteristics of the structure reveal the presence of an anomalous behavior at the forward bias. Though the capacitance reaches a peak, it remarkably decreases with an increasing bias voltage suggested by the presence of interface states. Furthermore, the energy distribution of interface density in the structures was determined by the forward bias C(V) measurement as well as using ideality factor and barrier height potential values obtained from forward bias I(V) and reverse bias C-2(V) characteristics, respectively. An estimated energy band diagram for the Au/n+-GaAs and Au/n-porous GaAs structures are presented. © 2013 Elsevier B.V.

Omri N.,Laboratoire Materiaux | Yahyaoui M.,Laboratoire Materiaux | Banani R.,Laboratoire Materiaux | Messaoudi S.,Laboratoire Materiaux | And 2 more authors.
Journal of Theoretical and Computational Chemistry | Year: 2016

Tryptophan methyl ester (Trp-ME) degrades with singlet oxygen and produce compounds which are photosensitizers and may react to form other derivatives such as N'-Formylkynurénine (NFK) and kynurenine, which are the final products of this oxidation. In order to study and optimize the molecular structure of NFK and determine its different thermodynamic properties, we performed a conformational analysis by DFT/B3LYP method with 3-21G basis set. Six most stable conformations were observed through the analysis of the potential energy surfaces, obtained by a relaxed scan of the dihedral angles. The most stable form of NFK has been registered for D1=-148.96°, D2=-116.89°, D3=-39.99°, D4=-65.50°, D5=163.75°, and D6=30.22°. The study was conducted by HF and DFT/B3LYP with 6-31G(d,p), 6-31+G(d,p) and 6-311+G(d,p) basis sets, on the optimized geometry of the most stable conformation and its thermodynamic and orbital properties. Two absorption bands were recorded at λ=250nm and at λ=340nm and were also determined by TD-DFT method. They showed good agreement with the UV experimental spectrum which confirms that it is a powerful tool to determine the dynamic and static properties of molecules. The surface of the electrostatic potential (ESP) of the NFK was also analyzed. © 2016 World Scientific Publishing Company.

Abourriche A.K.,Laboratoire Materiaux | Oumam M.,Equipe des Materiaux Thermostructuraux | Hannache H.,Equipe des Materiaux Thermostructuraux | Birot M.,CNRS Institute of Molecular Sciences | And 6 more authors.
Journal of Supercritical Fluids | Year: 2013

In the present work, the effect of solvent on the sub and supercritical extraction of the organic matter from Tarfaya's oil shales was studied. The experimental results revealed that the extraction yield obtained by the phenol is very high compared to that obtained by the toluene or without solvent. In addition, the solvent had a significant effect on the yield and the composition of the obtained oil. The analyses carried out on the recovered oils allowed us to establish that the phenol is a very efficient solvent for oil shale extraction, giving a better quality of the oils extracted containing a large proportion of maltenes and aromatics compounds and fewer amounts of sulphur and paraffin compounds. © 2013 Elsevier B.V. All rights reserved.

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