Crystal structure and electronic spectrum of InGaSe<Subscript>2</Subscript>

We report the synthesis and crystal growth of InGaSe₂. The crystals have been characterized by X-ray diffraction and InGaSe₂ has been shown to crystallize in tetragonal symmetry. Using first-principles density functional theory (DFT) calculations, we have found optimized lattice parameters and equilibrium atomic position coordinates of the compound semiconductor InGaSe₂. Based on the optimization results, we have calculated the band structure and the total and projected densities of states in InGaSe₂, found out the origin of its conduction and valence bands, and determined its band gap. Using the partial densities of states of its constituent atoms, we have evaluated the nature of the chemical bonding in InGaSe₂.     

Apoptosis-related protein expression in the hippocampus in Alzheimer''s disease

In HIV infected patients, the increase of the concentration of free radicals is related to: a depletion of protective system (glutathione peroxidase, superoxide dismutase, vitamin E, selenium ...), and an increased production of free radicals (superoxide anion, hydrogen peroxide, hydroxil radical) consecutive to the activation of lymphocytes and phagocyting cells, the chronic inflammation, the increased polyinsatured fatty acids concentration and lipoperoxidation, and direct or indirect effect of several pathologic agents including Mycoplasma sp. This free radical excess could impair cell membranes and generate apoptosis, the main cause of lymphocytes CD4+ depletion. After a brief review of the free radicals synthesis pathway, their potential deleterious effects and the protective systems, the role of free radicals in the pathogenesis of HIV infection are discussed in regard to data reported in the literature.     

Use of elimination of plasma phospholipid membranes for detection of "lupus anticoagulant" effects

The coagulation activity of plasma phospholipid membranes (PM) was measured in plasma depleted for platelets (PDP) in 50 normal subjects and 33 patients with the antiphospholipid syndrome (APS) and the "lupus anticoagulant" in the plasma. The normal value for phospholipid activation of clotting was 99.8 +/- 3.5% (from 75 to 125%), whereas in patients with APS and lupus anticoagulant it was 42.1 +/- 8.2% (p < 0.001). Addition of PM from patients' PDP to normal plasma free from PM did not normalize clotting. Addition of PM from normal plasma to patients' PDP normalized the clotting time. Therapy with discrete plasmapheresis increased the phospholipid activation value in the patients from 42.1 to 73.3% (p < 0.01), which was due to removal of the PM-antiphospholipid antibody complex from PDP. The proposed microfiltration method can be used in the complex of tests for detecting the lupus anticoagulant in patient's plasma.     

Paramagnetism and Electrical Conductivity Centre Relation in Semiconductor Oligoresorcinol

The electrical properties of oligoresorcinols with various concentrations of paramagnetic centres (N_s) in constant and variable electric fields have been investigated. It has been established that the electrical conductivity and the tangent of the dielectric loss angle are increased with the growth of N_s in the composition of the oligoresorcinol. With increase of frequency the electrical conductivity of oligoresorcinol increases according to the usual law. It has been shown that the electrical conductivity and concentration of paramagnetic centres of oligoresorcinol are interrelated and charge transfer in a variable field predominates at the expense of jumps of charge bearers between localized states with energy near the Fermi level. The densities of the states near the Fermi level for resorcinol examples have been calculated. The results show that, in this case, paramagnetic centres of the aroxyl type determine the density of the localized states near the Fermi level. © 1997 SCI.     

Antimicrobial properties of propylene oligomers modified with acylonitrile

The process of grafting of acrylonitrile to propylene oligomers was investigated. The modified samples of the oligomer were tested as biocidal additives for M-10 lube oil. It was shown that the nitrile modification products have fungicidal properties.