Thermal effects on liquid-crystalline order in polymers with mesogenic side groups

X-ray studies on polymers with phenyl benzoate side groups separated from the main chain by spacer groups of various lengths have been performed. It was found that the dimensions of liquid-crystalline regions are 15–20 nm, and they contain four to six close-packed layers. Thermal changes in x-ray scattering are associated with the variation of sizes and concentration of liquid-crystalline regions determined by the mobility of the main chain.     

Thermal Oxidation and Photochromic Properties of Molybdenum-containing Porous Glasses Obtained by Molecular Layering

Molybdenum oxide groups were synthesized on a porous glass surface by the molecular layering technique. Kinetic features of Mo(V) Mo(VI) transitions in thermal oxidation and photoreduction were studied for a set of samples containing 0.02-0.12 mmol g^{- 1} of molybdenum.     

Internal parameters of GaAs incoherent light sources

A method is used for separately measuring the radiative and radiationless lifetimes of nonequilibrium charge carriers in injection sources of incoherent light. The lifetimes, internal quantum efficiency, and the optical loss coefficient in the radiative recombination region are found for two types of homogeneous junction gallium arsenide laser diodes operating in the incoherent regime. It is shown that diffusively grown samples, having a greater internal quantum efficiency than epitaxial samples, also have higher losses due to absorption.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 32–36, January, 1976.     

Synthesis and structure of 4,6-di(tert-butyl)-2-(4-chloro-7,8-dimethylquinolin-2-yl)-7-(piperidin-1-ylmethyl)-1,3-tropolone

Russian Chemical Bulletin - The reaction of 4-chloro-2,7,8-trimethylquinoline with 4,6-di(tert-butyl)-3-(piperidin- 1-ylmethyl)-1,2-benzoquinone, which was prepared by the in situ oxidation of...     

Effect of natural polysaccharides and oligosaccharides on the permeability of cell membranes

Glycyrrhizic acid, arabinogalactan, and β-cyclodextrin are capable of forming complexes with various drug compounds significantly enhancing their solubility and bioavailability. To elucidate the mechanism of action of oligo- and polysaccharides, the exchange time of transporting formate ions through the membrane of myeloblastic leukemia cells (K562) was measured by NMR spectroscopy with the addition of paramagnetic ions. It was found that glycyrrhizic acid and arabinogalactan substantially increased the membrane permeability.