Interactions of the mitochondrial membrane rat liver D-3-hydroxybutyrate dehydrogenase with glass beads during adsorption chromatography. Relationships with the activation of the enzyme by phospholipids

D-3-Hydroxybutyrate dehydrogenase (BDH) is an NAD(+)-dependent dehydrogenase of the mitochondrial inner membrane involved in the energetic balance between the liver and peripheral organs in mammals. It allows the conversion of ketone bodies (acetoacetate and D-3-hydroxybutyrate) and it is one of the best documented lipid-requiring enzymes with a dependence on lecithins. After release of proteins from the membrane by phospholipase A2 treatment of salt-treated mitochondria, the rat liver enzyme is absorbed on controlled-pore glass beads. After batch washing, the enzyme, devoid of lipids (apoBDH), is specifically eluted at pH 8.05-8.15 with a 0.1 M Tris-1 M LiBr buffer under reducing conditions (5 mM dithiothreitol). It appears that during BDH absorption, the glass beads mimic the phospholipid surface of biomembranes.     

Photolysis of 2-dialkylamino-3-methyl-1,4-naphthoquinones

The photolysis of 2-dialkylamino-1,4-naphthoquinones is significantly more efficient when a methyl group is at C³. The quantum yields are 2–6 times greater than for 2-dialkylaminonaphthoquinones lacking a methyl group. 2-Monoalkyl-amino-1,4-naphthoquinones also undergo photochemical dealkylation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2387–2392, October, 1991.     

Quasiparticle and Cooper pair tenneling in small capacitance Josephson junctions

The tunneling of single electrons in small capacitance tunnel junctions is influenced by charging effects and by the fluctuations of the elecromagnetic environment. We study the effect of an external circuit with arbitrary impedance on the tunneling of quasiparticles and Cooper pairs in voltage driven Josephson junctions. We present results at finite temperatures and also consider an acdriven system.     

On the analytical solutions of unstable surface layer similarity equations

Summary An approximate relationship between the gradient, Ri, and the bulk Richardson number, Ri_b, for unstable atmospheric conditions, is suggested. The proposed relation shows much better agreement with the estimation provided by a numerical iterative method than the usual approximations suggested by Louis and Byun.     

Paramagnetic defects in BaTiO3 and their role in light-induced charge transport — Optical studies

On the basis of a previous identification of paramagnetic defects in nominally undoped as grown BaTiO₃ single crystals, we have investigated the changes of the concentrations of these centers and their optical absorptions under illumination with light of varying wavelengths. The most pronounced charge transfers occur by hole ionization of Fe⁴⁺ and — to a lesser extent — of Cr⁵⁺ and Cr⁴⁺. At low temperatures the created holes are trapped in the form of O^–-ions next to Al³⁺ or unknown acceptor defects. Corresponding Fe⁴⁺ and O^– absorptions have been identified.     

Elastoplastic state of axisymmetrically loaded laminated bodies of revolution made of isotropic and orthotropic materials

Institute of Mechanics, Ukrainian Academy of Sciences, Kiev. Translated from Prikladnaya Mekhanika, Vol. 28, No. 1, pp. 31–39, January, 1992.     

Complex formation of vinylidene chloride with hydrogen chloride in the solid phase at low temperatures

Moscow State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 2, pp. 170–174, March–April, 1992.     

Radiochemical solvent extraction method for the determination of Cd and Hg using thionalide as a single reagent

A radiochemical solvent extraction method has been developed for the simultaneous determination of submicrogram amounts of Cd and Hg using^115mCd and²⁰³Hg tracers respectively and thionalide as a single complexing reagent. Hg was determined by 0.05% thionalide in ethyl methyl ketone (EMK) at pH 8.5, masking Cd with 0.1M KCN. From the aqueous phase Cd was demasked using formal-dehyde-acetic acid, pH adjusted to 9.5 and extracted into 0.05% thionalide in chloroform. The method is simple, fast and yields accurate results.