Electrical conductivity and thermoelectric power of liquid selenium doped with thallium and indium

The temperature dependence of the electrical conductivity and thermoelectric power of liquid selenium with thallium and indium additives have been studied. Large variations appear in the electrical conductivity and thermoelectric power, where Tl and In additives favourp-type conduction.     

Géométries Lorentziennes de dimension 3 : classification et complétude

We classify three-dimensional Lorentz homogeneous spaces G/I having a compact manifold locally modeled on them. We prove a completeness result: any compact locally homogeneous Lorentz threefold M is isometric to a quotient of a Lorentz homogeneous space G/I by a discrete subgroup Γ of G acting properly and freely on G/I. Moreover, if I is noncompact, G/I is isometric to a Lie group L endowed with a left invariant Lorentz metric, where L is isomorphic to one of the following Lie groups:

Extrapolation spaces and controllability of impulsive semilinear functional differential inclusions with infinite delay in Fréchet spaces

In this article, we investigate some classes of semilinear impulsive functional differential inclusions with infinite delay. It is assumed that the linear part is possibly neither densely defined nor it satisfies the Hille–Yosida condition on a Banach space, namely the extrapolated space. Our approach is based on the theory of extrapolation spaces combined with a recent Frigon nonlinear alternative for multivalued admissible contractions in Fréchet spaces.     

On First Order Impulsive Dynamic Equations on Time Scales

In this paper, the nonlinear alternative of Leray-Schauder type is used to investigate the existence of solutions for first order impulsive dynamic equations on time scales.     

LC–DAD/ESI–MS/MS characterization of phenolic constituents in Rosa canina L. and its protective effect in cells

In an aim to prove the efficiency of polyphenols of Rosa canina fruits in promoting human health. A methanolic extract of R. canina fruits was prepared by successive maceration with solvents of increasing polarity. The polyphenol composition was analyzed by HPLC–DAD–ESI–MS. The biological activity of this extract on SH-SY5Y cells and HepG2 cells was then studied. The antioxidant activity was tested by various in vitro tests such as DPPH-radical-scavenging activity, FRAP assay, hydroxyl radical scavenging assay and total antioxidant capacity. The subacute toxicity of R. canina was tested on female rats by repeated intraperitoneal administration of various doses. The phenolic profiles showed 25 antioxidants distributed into three classes of phenolic compounds: glycosylated and agglomerated flavonoids/isoflavonoids, tannins and phenanthrenes. Qualitative phytochemical analyses showed that this extract lacks alkaloids. The methanolic extract of R. canina fruits has a total antioxidant capacity of 82.69 ± 1.18 μg EAA/mg of methanol extract and the IC₅₀ of the methods used is in the following increasing order: FRAP assay (61.88 μg/ml), then hydroxyl radical scavenging assay (67.45 μg/ml) and then DPPH radical-scavenging activity (129.81 μg/ml). The extract of R. canina did not cause any phenotypic signs of toxicity or mortality during and after treatment. The LD₅₀ was >5,000 mg/kg, hence, R. canina was considered nontoxic. An in vivo study proved the protective effect of R. canina against cardiac and hepato-renal toxicities. These results drew the importance of a healthy diet, where diets rich in R. canina fruits can be used as a rich natural source of antioxidants and anticarcinogenic phenolic compounds.     

Novel hybrid materials based on poly (4,4′-Diaminodiphenyl sulfone) and TiO2 nanoparticles: synthesis,characterization, physical and electrochemical properties

Research on Chemical Intermediates - Innovative hybrid composites based on poly (4,4'-Diaminodiphenyl sulfone) (PDDS) and TiO2 nanoparticles have been synthesized. The samples have been...