Molecular dynamic simulation methods for anisotropic liquids

Methods of molecular dynamics simulations for anisotropic molecules are presented. The new methods, with an anisotropic factor in the cell dynamics, dramatically reduce the artifacts related to cell shapes and overcome the difficulties of simulating anisotropic molecules under constant hydrostatic pressure or constant volume. The methods are especially effective for anisotropic liquids, such as smectic liquid crystals and membranes, of which the stacks of layers are compressible (elastic in direction perpendicular to the layers) while the layer itself is liquid and only elastic under uniform compressive force. The methods can also be used for crystals and isotropic liquids as well.     

Low p T phenomena in A+A and p+A collisions at mid-rapidity

CERN experiment NA44 measures pion and kaon distributions at p _T = 0–320 MeV/c at midrapidity in p+A and A+A collisions at 450 and 200A GeV/c, respectively. Pion production from p+Pb and A+A is slightly enhanced at low p _T relative to p+Be, but less than observed at target rapidity. The low p _T behavior can be understood in the context of the RQMD model as arising from baryonic resonance decays.     

Reduction of carbonyl groups to the corresponding methylenes with Ni-Al alloy in water

The reduction of carbonyl compounds 1a-h using Ni-Al alloy in water under reflux proceeded to give the corresponding methylene compounds 2a-h within 2 h in 89.0-99.8% relative yields.     

Polarographic reduction of 1-substituted 1,2,4-triazoles

The polarographic reduction of 1-substituted 1,2,4-triazoles in dimethylformamide (DMF) and acetonitrile was studied. 1-Methyl-, 1-ethyl-, and 1,2,4-triazoles are not reduced on a mercury electrode over the range of potentials accessible for polarography. 1-Phenyl-1,2,4-triazole and 1-vinyl-1,2,4-triazole are reduced in acetonitrile via a one-electron mechanism at high negative potentials. The reduction of 1-vinyl-1,2,4-triazole is accompanied by polymerization of the electrolysis products. A possible mechanism for the electrochemical reduction is discussed. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 408–410, March, 1980.     

Viscometric assay for determining lysozyme activity

A method was developed for determining the activity of lysozyme using two pipettes as a viscometer. The proposed viscometric assay uses carboxymethylchitin as a substrate and measures the enzyme activity at 22°C. The method requires only simple manipulations with the use of readily available laboratory equipment and the determination of enzyme activity is rapid.     

Use of 1,3-dioxin-4-ones and their related compounds in synthesis. Part 28 . Asymmetric de mayo reactions using chiral spirocyclic dioxinones

The use of rigid spirocyclic dioxinones having 1-menthone as the chiral auxiliary as the enones in the photo[2 + 2]cycloaddition reactions opened novel methods for obtaining enantiomerically pure compounds, such as iridoids. Convex side preference of the sofa-conformation of these dioxinones in the photoaddition to cyclopentene increases up to 100% by introducing either a bulky substituent or 5-hexenyl group at the 3-position to these dioxinones and, hence, highly asymmetric inter- and intramolecular de Mayo reactions have been disclosed.     

LowpT phenomena in A+A and p+A collisions at mid-rapidity

CERN experiment NA44 measures pion and kaon distributions atpT=0–320 MeV/c at midrapidity in p+A and A+A collisions at 450 and 200A GeV/c, respectively. Pion production from p+Pb and A+A is slightly enhanced at lowpT relative to p+Be, but less than observed at target rapidity. The lowpT behavior can be understood in the context of the RQMD model as arising from baryonic resonance decays.     

Reaction of α-ethoxyacrolein with alcohols: A new method of synthesis of acetals of methylglyoxal

Conclusions The reaction of-ethoxyacrolein with alcohols produces the acetals of methylglyoxal in 55–65% yields.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1878–1879, August, 1984.