Novel functional activities of anti-dna autoantibodies from sera of patients with lymphoproliferative and autoimmune diseases

DNA-hydrolyzing activity of IgG autoantibodies from sera of patients with various types of lymphoproliferative diseases was investigated. The association of DNA-hydrolyzing activity with the antibody (Ab) fraction has been proved by newly developed affinity-capture assay. Study of abzyme incidence in blood tumors and systemic lupus erythematosis (SLE) revealed linkage of anti-DNA Ab catalysts to mature B-cell tumors, and increased probability of DNA-abzymes formation on the background of autoimmune manifestations. These data suggest possible similarity between mechanisms of abzyme formation in SLE and B-cell lymphomas. A new mechanism of formation of DNA-specific catalytic Abs has been proposed based on the increased crossreactivity of polyclonal DNA-abzymes to DNA-depleted nuclear matrix proteins. The possibility of the abzyme production as Ab to the energetically destabilized ground state of the antigen has been discussed. Preliminary results were obtained that indicate the complement-independent cytotoxicity of anti-DNA autoantibodies isolated from blood of patients with SLE and chronic lymphocytic leukemia.     

Modulated Pseudo-Hermitian Dimer

Russian Physics Journal - A modulated pseudo-Hermitian optical dimer is investigated. The parameter ranges are determined where the eigenmodes of the dimer conserve their power. It is shown that...     

New diluted ferromagnets based on diamond-like semiconductors GaSb,InSb, InAs,Ge, and Si,supersaturated with manganese or iron impurities during laser epitaxy

The electric, magnetic, and magneto-optical properties of thin (50–100 nm) GaSb:Mn, InSb:Mn, InAs:Mn, Ge:Mn, Ge:Fe, Si:Mn, and Si:Fe layers with a Curie point up to 500 K, obtained by laser plasma deposition in vacuum in the case of strong supersaturation of a solid solution with a 3d impurity, have been experimentally investigated.     

Photochemical oxidation of 4h-seleno(thio)pyrans

Oxidation of solutions of 4H-thiopyrans and 4H-selenopyrans to the corresponding heteroaromatic cation bromide occurs on irradiation with ultraviolet light in the presence of CBr₄. Reaction takes place by a free radical chain mechanism. The presence of CHBr₃ and C₂Br₆ in the reaction mixture was detected chromatographically.N. G. Chennyshevskii Saratov State University, Saratov 410026, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 749–751, June, 1999.     

Gas-chromatographic determination of O-isobutyl-S-2-(N,N-diethylamino)ethyl methylphosphonothioate (VX-like compound) and O-isopropyl methylphosphonofluoridate (Sarin) traces in slag

Procedures for the determination of 04sobutyl- S-2-(N,N-diethylamino)ethyl methylphosphonothioate (VX-like compound) and sarin traces in slag at levels of 5 × 10^-5 and 1 × 10^-2 mg/kg, respectively, were developed. The procedures are based on the extraction of organophosphorus chemical warfare agents from slag, the preconcentration of the extract, and the conversion of the analytes into dialkyl methylphos-phonates with the use of optically active alcohols. In this case, a solution of AgNO₃ in 4-methyl-2-pentanol or a sodium alcoholate solution was used for the derivatization of VX or sarin, respectively. The resulting dias-tereomers were determined by gas chromatography with the use of a flame-photometric detector. The analysis time was no longer than 1.2 or 1 h for the VX-like compound or sarin, respectively.     

Intracavity laser spectroscopy

The main features of broadband intracavity laser spectroscopy (ILS), the most sensitive technique of absorption-spectrum measurements, is investigated. The factors that limit the sensitivity of the ILS method are studied, and the conditions for reaching its maximum sensitivity are formulated. The main practical applications of the ILS method are described, such as detection of weak absorption spectra and measurements of low gas concentrations, registration of amplification spectra and of the spectral distribution of external radiation, measurement of the cross sections for nonlinear processes, investigation of transient processes in an electric discharge, and investigation of the kinetics of multistage chemical reactions.Translated from Preprint No. 187 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1988.     

Isotopic Analysis of 28Si-Enriched Silicon Using Laser Mass Spectrometry

A procedure for the isotopic analysis of ²⁸Si-enriched silicon by laser mass spectrometry is described. The procedure is based on the analysis of a dry concentrate or a film obtained by the pneumatic nebulization of an analyte and an internal standard solution or by the laser sputtering of a solid phase onto a support of a high-purity substance. The range of determinable isotope concentrations is (100–n× 10^–6) at %; the total error in determining the major isotope is n× 10^–2at % at an enrichment factor higher than 99%. The procedure provides the simultaneous control of 70 impurity elements in the sample.     

Spatiotemporal characteristics of laser emission. I

The first chapter describes the general premises of the electrodynamic theory of the laser as a nonstationary nonlinear oscillatory system with spatially distributed parameters. Maxwell's equations are used to derive an equation for the complex amplitude of the electromagnetic field in a cavity filled with transversely inhomogeneous active medium. The self-conssitent analysis includes a simultaneous solution of the equations for the field and for the inverted population. In the second chapter, electrodynamic theory is applied to injection and electron-beampumped semiconductor lasers. The threshold characteristics, the field structure in the near and far zones, the lasing regimes of semiconductor lasers, and the influence of nonlinearity of the refractive index are considered.Division of Quantum Radiophysics, Lebedev Physics Institute. Translated from Preprint No. 33, Lebedev Physics Institute, Moscow, 1990.