[en] Cadmium, a heavy metal environment contaminant, induces fetal death and placental necrosis in the Wistar rat. This study investigated fetal, maternal, and placental responses to cadmium intoxication. Subcutaneous injection of CdCl₂ to dams on day 18 of pregnancy produced a high incidence of fetal death (75%) and placental necrosis. Death in the fetus was produced despite limited fetal accumulations of cadmium. Distribution studies using ¹⁰⁹Cd-labeled CdCl₂ demonstrated that less than 0.1% of the injected dose was associated with the fetus. To determine if fetuses were sensitive to these low levels of cadmium, direct injections of CdCl₂ into fetuses were performed in utero. Direct injections produced fetal accumulations 8-fold greater than those following maternal injections. The 8-fold greater fetal accumulations following direct injection were associated with only a 12% fetal mortality compared to the 75% mortality following maternal injections. The data indicated that the fetal toxicity of cadmium following maternal injections was not the result of direct effects of cadmium on the fetus. In conclusion, cadmium-induced fetal death was not the result of direct effects of cadmium on the fetus but may have been induced by placental cellular injury resulting from high accumulations of cadmium in the placenta. A vascular response to placental injury, leading to decreased utero-placental bood flow and cadmium-induced alterations in trophoblastic function, resulted in fetal death

[en] The Green's-function (GF) method has been applied to the investigation of the electronic structure of defects in A/sup N/B/sup 8-N/ semiconductors. Localized states in the forbidden gap and resonance states in the allowed bands induced by group V and group VI impurities, mono- and multivacancies, and complexes of point defects have been considered. It has been shown that the semiempirical variant of the GF method in a basis of localized orbitals makes it possible to describe the behavior of defect levels in the framework of a single approximation for an extensive list of objects on a qualitative or semiquantitative level. Several procedures for the application of the extended defect molecule method, which makes it possible to combine the advantages of the GF and molecular cluster methods, have been discussed

[en] Short note

No abstract available

[en] The question of the structure of complexes of the type trans-Cu/sup II/ (NH₃)₂Hal₄ has been studied from the point of view of the theory of the Jahn-Teller effect. It has been shown that the existence of two isomers with D/sub 4h/ and D/sub 2h/ symmetry in such complexes can be explained when the linear and quadratic terms in the vibronic coupling operator and the differences between the ligands in the first coordination sphere of the metal are taken into account without relying on any intermolecular interactions. An explanation for the experimentally observed interatomic distances in the chainlike compounds with Hal = Br and Cl requires consideration of the interaction of the Jahn-Teller e/sub g/* orbitals with the higher lying α/sub 1g/* state

[en] The electronic structure and ionization potentials (IPs) of dimers of metals from the first and second transition periods have been calculated by the discrete-variation-X-/sub α/ (DV-X/sub α/) method. It has been shown that in all cases, with the exception of Fe₂, the first IP corresponds to ionization form an MO of the sσ/sub g/ type. The values of the IPs obtained are in good agreement with the available experimental data

[en] On the basis of the theory of electron-vibrational interactions heteroligand molecules and MLsub(n-k)Xsub(k) complexes are considered. The trans-effect in (Te, Pt, Pd) transition meetal complexes, in nontransition elements compounds with low and higher oxidation degrees (IOF₅) is discussed. The multiple bond systems and ligand mutual effect in actinide complexes (VOCl₅^-) are considered. Stereochemistry of these systems, relative geometric isomer stability and some problems connected with isomerization reactions are discussed

[en] The most important element of nuclear power plant safety is control of critical component life parameter evolution. The use of expert systems provides a qualitative estimate on the influence of the factors disregarded in mathematical models and a feedback with the technological systems component. The feedback results in more accurate and complete information concerning the knowledge of the object and damage material

[en] Short note

No abstract available