Wave processes at the cellular level

This paper is a review of studies of wave phenomena in biological tissues at the cellular level. Autowave processes of mechanicochemical deformation of cells are examined, related to activation of calcium ion sources in muscle and other cells. The collective effects arising during cell fusion are described. Possible self-organization methods and dissipative restructuring of cell shapes and microvessels are discussed.     

Spatial Structure of the Decapeptide Val-Ile-Lys-Lys-Ser-Thr-Ala-Leu-Leu-Gly in Water and in a Complex with Sodium Dodecyl Sulfate Micelles

We have studied the spatial structure of the decapeptide Val-Ile-Lys-Lys-Ser-Thr-Ala-Leu-Leu-Gly in aqueous solution and in a complex with sodium dodecyl sulfate (SDS) micelles by ¹H nuclear magnetic resonance (NMR) spectroscopy and two-dimensional (2-D) NMR spectroscopy (total correlation spectroscopy and nuclear Overhauser effect spectroscopy (NOESY)). The approach used to determine the decapeptide spatial structure was based on analysis of the ¹H?C¹³C residual dipolar couplings in the molecules partially aligned in lyotropic liquid crystalline media. Analysis of the interproton distances obtained from the 2-D NOESY NMR spectrum was used to reveal the spatial structure of the decapeptide in a complex with SDS micelles. Complex formation was confirmed by analysis of ¹H chemical shifts in the NMR spectrum of the decapeptide and analysis of the signs and values of NOEs in a solution with SDS micelles.     

Geometric Structure of 2-Phenyl-1,3-dithia-5,6-benzocycloheptene 1-Oxide

Two-dimensional nuclear Overhauser effect spectroscopy (2D NOESY) was used to determine proton-proton distances for the chair conformer of 2-phenyl-1,3-dithia-5,6-benzocycloheptene 1-oxide in CD₂Cl₂ in the system CS₂-CDCl₃. Changing the solvent by a more polar changes the molecular conformation. As a result, the dipole moment may also be affected, and this should be taken into account in analysis of solvent effects on thermodynamic parameters of the conformational equilibrium.     

Synthesis of a new quaternary phosphonium salt: NMR study of the conformational structure and dynamics

A novel phosphonium salt based on pyridoxine was synthesized. Conformational analysis of the compound in solution was performed using dynamic NMR experiments and calculations. The obtained results revealed some differences in the conformational transitions and the energy parameters of the conformational exchange of the studied compound in comparison to previously reported data for other phosphorus‐containing pyridoxine derivatives. It was shown that increasing the substituent at the C‐11 carbon leads to greater differences in the populations of stable states and the corresponding equilibrium energies. Copyright © 2015 John Wiley & Sons, Ltd.     

Vibroacoustic processes and structural variations in muscular tissue

This paper reviews the problems and results obtained in the course of experimental and theoretical investigations of the vibroacoustic activity of contracting muscles. Two types of such processes are examined: (1) acoustic vibrations due to the macromolecular recombinations of muscle proteins, which are responsible for the muscle contraction, and (2) acoustic vibrations associated with the finite accuracy and speed of the receptor-effector system that controls the muscle contraction. By investigating the acoustic vibrations, we examine structural recombinations (conformation variations) in macromolecules during mechanochemical reactions. Since chemical reactions of macromolecules are always accompanied by conformational recombinations, the generation mechanism, which is responsible for the contraction processes in a muscular tissue, can also be extended to other macromolecular media. Investigation of infrasound vibrations makes it possible to explore the quality and error of control for the processes in the muscle under different types of loading. Since a living body is controlled via perceptions, the latter can be quantitatively estimated by the parametess of infrasound vibrations.Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, Nos. 3–4, pp. 357–367, March–April, 1995.     

The role of the entropy factor in the stabilization of the Z-enol form in methyl 2-dimethoxy-phosphoryl-3-oxobutyrate

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, p. 1194, May, 1990.     

Annealing of PrF3 nanoparticles by microwave irradiation

The influence of microwave irradiation on the recovery of nanocrystalline PrF₃ powders has been experimentally analyzed by nuclear magnetic resonance (NMR) at T = 1.5 K. It is established that the relaxation times of ¹⁴¹Pr and ¹⁹F nuclei rise significantly with an increase in the hydrothermal-treatment time, whereas the ¹⁴¹Pr NMR spectra narrow, which indicates a decrease in the number of defects in the lattices of nanosamples.