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1,2,4-Triazolo[3,2-b]-1,3-thiazines were obtained by the reaction of 1,2,4,-triazole-3-thiones with an equimolar amount of 1-phenyl-2-cyanoacetylene in the presence of triethylamine or potassium hydroxide. It is shown that triazolethiones form N,S diadducts upon reaction with a twofold excess of cyanoacetylene. The nature of the heteroatom in the exo position of the heteroring affects the direction of addition to phenylcyanoacetylene. 2,4-Bis(1-phenyl-2-cyanovinylene)-1,2,4-triazol-3-one was synthesized.

4-Hydroxy-4-methyl-2-pentynonitrile is transformed by the action of LiOH in water to 2,2,4,4-tetramethyl-5-cyanomethylene-1,3-dioxolane and 5-amino-2,2-dimethyl-2,3-dihydro-3-furanone.

Furan and tetrahydrofuran amines with the amino group at position 4 or 5 in the side chain are intramolecularly dehydrated to the corresponding 1-azabicyclo compounds when passed over Al2O3-ZrO2 catalyst at 325–330°.

The composition of mixtures of epimeric 3-methylpyrrolizidines obtained by four methods was determined by gas-liquid chromatography (GLC). The data presented make it possible to select a method for the preparation of a mixture of isomers of 3-methylpyrrolizidine with predominance of trans- or cis-3,8-H-3-methylpyrrolizidine.

A general theory has been developed for conformational intramolecular transitions in a single macromolecule with a high degree of polymerization (an infinite length model) capable of forming two types of ordered structures: the α-helix and the folded β-structure, as well as acquiring the random coil conformation. The phase diagram analysis of this system has shown that the regular β-structure state is separated from all other states of the chain by the phase boundary line. Any intersection of the phase boundary is a phase transition which can be either of the first order or second order, depending on values of the energy parameters of the system. Mechanisms of intramolecular rearrangements: β-structure–random coil and α-helix–β-structure have been discussed. It has been shown that there exist two different mechanisms for each of these rearrangements, and the regions of parameter variation corresponding to each mechanism have been specified.

The paper provides a description of an equipment system comprising a pair of 25 MeV high-current betatrons and an X-ray drum-type cinecamera for high-speed radio-graphy and X-ray cinematography for use when studying dynamics of objects moving at a rate of 0.5-3.0 km/s as well as in X-ray cinematography of processes at a rate of up to 1 m/s.© (1979) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The connection between geometrical characteristics of the proteoglycan (its thickness Hp and the mean stretch of Rp) and the parameters of the initial chemical structure of proteoglycan molecule constituents are established. The calculations are carried out by a mean field method.

An analytical theory of helix-coil transitions for polypeptides in a solution near a flat and homogeneous interface is given. The following cases were considered: a) only the helical parts are absorbtively active; b) only the coiled sections of the chain are active in adsorption. It has been shown that the binding of the polymer chain to the surface is a result of a phase transition of a second order, moreover in case a) the presence of a secondary structure abruptly increases the ability of the macromolecules to bind to the interface. This largely increases the stability of the helical structure of the chain and leads to a practically complete spiralization of the macromolecule. The profile of the conformational transitions was strictly asymmetrical which is typical for the phase transitions. In case b) the process of binding resembles the adsorbtion of the Gaussian coils. In this case the rate of spiralization of the chain decreases in the course of binding and the degradation of the secondary structure is significant even if the helical state in volume is stable. The profile of the transition remains qualitatively similar to the helix-coil transition in volume but is displaced to the region of larger equilibrium constants.

Lipopolysaccharides were isolated from the phenol layer on aqueous phenol extraction of cells of Pseudomonas aeruginosa O11 (Lányi classification), strains 170021 and 170040. On mild acid degradation of the lipopolysaccharides, with the subsequent gel-filtration on Sephadex G-50, neutral O-specific polysaccharides made up of 6-deoxysugars alone were obtained. Two 2-acetamido-2,6-dideoxy-L-galactose (LFucNAc), 2-acetamido-2,6-dideoxy-D-glucose (DQuiNAc) and L-rhamnose (LRha) residues were found to be the components of the strain 170021 polysaccharide repeating units; those of strain 170040 contained the same monosaccharides, but, instead of 2-acetamido-2,6-dideoxy-D-glucose residue, that of 2-acetamido-2,6-dideoxy-D-galactose (DFucNAc) was present. On the basis of the 13C nuclear magnetic resonance data, methylation analysis and three successive Smith degradations the following structures were determined for the polysaccharide repeating units: strain 170021----2) LRha(alpha 1----3)LFucNAc(alpha 1----3)LFucNAc(alpha 1----3)DQuiNAc(beta 1----; strain 170040,----2)LRha(alpha 1----3)LFucNAc-(alpha 1----3)LFucNAc(alpha 1----3)DFucNAc(beta 1----; differing from one another by configuration of C-4 of 2-acetamido-2,6-dideoxy-D-hexopyranose only.

A method of an integral evaluation of the performance of man-operator based on a unified system of specific and integral criteria of the quality and strain of the work is presented. Experimental results of an application of this method for studying the effect of velocity indicators on the human performance during manual control are given.

The addition of HBr to tertiary cyanoacetylenic alcohols is accompanied by intramolecular cyclization, which leads to the hydrobromides of bromiminodihydrofurans.

The results of a dynamical Monte-Carlo study on the coil-globule and globule-coil transitions are presented. Self-avoiding chains of lengths N = 32 and 64 are investigated. The kinetic model included two- and three-bonds flips. The relaxation of the chain was induced by the abrupt change of the interaction between the monomers. The time evolution of the radius of gyration and the number of intramolecular contacts was obtained. It is established that the transition to the compact state occurs due to the contacts between the monomers close to each other along the chain. The results obtained are compared with the predictions of analytical theories.

Aus 2-Methyl-1-hydroxy-3-butanon-oxim (I) erhalt man bei der Umsetzung mit Acetylen (II) in Dimethylsulfoxid bei 100°C unter einem Druck von 14 at nicht das zu erwartende Pyrrol (III), sondern unter Abspaltung von Formaldehyd das 1-Vinyl-2,3-dimethyl-pyrrol (IV).

The possibility of using protective silicon dioxide masks for the localization of growth in the epitaxial deposition of semiconductor materials was established at the beginning of the 60’s [1, 2], Many publications have been devoted since then to the study and development of planar selective epitaxy, a process in which the holes etched through windows in the protective mask are filled in a controlled manner by the epitaxially deposited material. Practical cases of great interest are planar local epitaxial structures in which the surface of the grown layer coincides (is coplanar) with the surface of the original substrate. It has been shown [3–7] that considerable difficulties have to be overcome to achieve coplanarity in the desired structures. The holes may be filled both by upward growth from the bottom (normal growth) and via growth starting from the side walls of the holes (tangential growth); consequently, a specific ratio of the normal and tangential growth rates must be maintained to achieve coplanarity.