On the explosion of linearly distributed charge with curvilinear shape on the ground surface

We use the momentum version proposed by M. A. Lavrent'yev [1, 2] to treat the two-dimensional problem of the explosion of a linearly distributed charge of curvilinear shape on the ground surface. The problem of the explosion of a straight charge was solved for the first time in [2] in this version. The ground is assumed to be an ideal incompressible liquid at velocities exceeding some critical velocity which remains constant along the crater; beyond this boundary, the medium is fixed. The potential of the velocity is assumed to be constant on the charge and vanishing on the ground surface.     

Properties of 8-hydroxyquinoline immobilized on a silica surface

The ionization constants of benzeneazo-8-hydroxyquinoline grafted to a silica surface were determined by potentiometric titration. The spectrophotometric measurements showed that with increase in pH, deprotonation of the grafted 8-hydroxyquinoline nitrogen takes place. The dynamic capacity of the sorbent obtained with respect to the Cu²⁺, Co²⁺, and Ni²⁺ ions at various pH was determined. The immobilized benzeneazo-8-hydroxyquinoline is suitable for removing trace amounts of metal ions from solutions and for their chromatographic separation. It was found that the metal complexes of Cu²⁺ and Co²⁺ with grafted benzeneazo-8-hydroxyquinoline exhibit catalytic activity in the oxidation of hydrazine by molecular oxygen in aqueous solutions.Translated from Teoreticheskaya i Ékperimental'naya Khimiya, Vol. 25, No. 1, pp. 108–112, January–February, 1989.     

Synthesis and structures of molecular complexes of the cis-anti-cis diastereomer of dicyclohexano-18-crown-6 with o-nitroanilines

In the reaction of the cis-syn-cis and cis-anti-cis diastereomers of dicyclohexano-18-crown-6 with 2-nitro and 2,4-dinitroaniline crystalline complexes with a 1:2 stoichiometric composition were obtained only when the cis-anti-cis diastereomer was used. The three-dimensional structure of the complex of the cis-anti-cis diastereomer of dicyclohexano-18-crown-6 with 2,4-dinitroaniline was determined by an x-ray diffraction study. The complexing of o-nitroanilines with the cis-anti-cis diastereomer is explained by the topological conformity of the interacting compounds. The isolation of the individual cis diastereomers from the mixture of them formed as a result of the catalytic hydrogenation of dibenzo-18-crown-6 was accomplished by means of the selective formation of the crystalline complex of the cis-anti-cis diastereomer with 2-nitroaniline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1190–1195, September, 1988.     

Redox photochemistry of thiouredopyrenetrisulfonate

1-Thiouredopyrene-3,6,8-trisulfonate (TUPS) has recently been used as a photoinduced covalent redox label capable of reducing various cofactors of proteins. A new reaction of this dye, whereby its excited triplet state oxidizes suitable electron donors, is now reported. The characteristic difference spectrum of the reduced radical of TUPS is determined. We also observe the self-exchange electron transfer between two TUPS molecules in their triplet excited states and determine the reaction scheme and the rate constants of the various pathways in the process of triplet depletion. The ability of photoexcited TUPS to withdraw an electron from reduced cytochrome-c is also observed. It is thus demonstrated that TUPS is an appropriate photoinduced covalent redox label for initiating both the oxidative and reductive phases of electron transfer processes in biological macromolecules.     

Acylation of aza crown ethers with N-substituted isophthalimides

Acylated aza crown ethers containing fragments of N-substituted phthalamic acids in the side chain were obtained by the reaction of monoaza-15-crown-5, monoaza-18-crown-6, and diaza-18-crown-6 with N-substituted isophthalimides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 536–539, April, 1987.     

High-speed analysis of multiplexed short tandem repeats with an electrophoretic microdevice

We report the development of a robust and effective method for multiplexed short tandem repeat (STR) analysis within a chip-based microdevice. The method uses a laser-induced fluorescence detection system and simultaneously detects three- and four-color multiplexed polymerase chain reaction (PCR) samples. Analyses of the eight combined DNA index system (CODIS) STR loci were performed in 20 min with single-base-pair resolution ranging from 0.75 to 1. A simultaneous analysis of fifteen loci-ladders and a gender marker Amelogenin based on the PowerPlexTM 16 System was achieved in less than 35 min. The system is capable of repetitive operation and may be extended to high-throughput multilane devices that could be readily interfaced to an automated sample loading system.     

Unexpected 3:2 stoichiometry and structure of 15-crown-5 complex with lithium chlorochromate

X-ray diffraction study of the lithium chlorochromate complex with 15-crown-5 (15C5) revealed the existence of an unexpected complex dication with [(15C5)₃Li₂(H₂O)₂]²⁺ composition, which is also stable in the gas phase according to the quantum-chemical calculations by B3LYP/6-311+G(d,p) method.