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Biomedical subjects

A N Kuznetsov

Publications and source records attributed to A N Kuznetsov.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Extremely high frequency dielectrometry of biological fluids under conditions of disturbed water balance].

The electrical properties of fractions of blood, B-bile, and aqueous ethanol solutions were studied by UHF dielectrometry. A relationship between the electric permittivity of these biological liquids at a frequency of 62 GHz and their functional value was established. The changes in the electrical characteristics of the solutions in some disturbed functional states were explained by the rebuilding of water quasicrystaalline structure.

Bile↗
PubMedDate not supplied

[Study of water exchange in skin tissues by microwave dielectrometry].

The complex dielectric permitivity of human skin was measured at a frequency of 42 GHz, and a method for calculating water content in skin tissues in vivo was proposed. The water content reaction of skin to standard physical exercises and nontoxic doses of nicotine was investigated. The functionally related changes in skin dielectric properties were interpreted as structural rearrangements of water contained in blood and tissues fluids.

Adult↗
PubMedDate not supplied

[UHF-dielectrometry in the assessment of the structural organization of salt solutions and interstitial fluids in normal and cicatricial tissues].

The complex dielectric permittivity of salt solutions with positive and negative salvation as well as healthy and cicatricially changed human skin in situ at the frequencies of 42 and 56.6 GHz was measured. The relation between the dielectric characteristics of water and diluted salt solutions and changes in their structural organization conditioned by different temperatures of samples and the type of salvation of electrolytes was studied. The differences in the dielectric characteristics of healthy and cicatricially changed skin are interpreted in terms of the dependence of the structural organization of interstitial fluids on the morphological and functional state of biological tissues.

Cicatrix↗
PubMedDate not supplied

[Need to measure the viscosity of solutions of globular proteins when studying their rotational mobility by the spin probe method].

It is shown that for correct determination of correlation time of protein rotation, at least for high concentration, it is necessary to measure the viscosities of investigated solvents, whereas for definition by method of extrapolation values Azz the viscosity of water solution of sucrose may be taken as the viscosity of investigated solutions.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

[Study of the conformational changes of serum albumin molecules within a pre-denaturation temperature range by a spin probe technique].

To study conformational changes of protein molecules in a pre-denaturation temperature range, nitroxyl radicals adsorbed by a protein are suggested to be used. A spin probe technique is specially developed to be implied for this aim by using a probe specifically bound to the bovine serum albumin molecule, it was possible to reveal a dependence of the rotation correlation time of the adsorbed radical and the environment polarity on the temperature. The data obtained testify in favour of a change occurring in the intramolecular structure of the protein under study due to a temperature change within the pre-denaturation temperature range.

Animals↗
PubMedDate not supplied

[A study of the Brownian movement of alpha-chymotrypsin molecules by the spin probe method].

The rotation of alpha-chymotripsin in water solution is studied by use of nitroxyl radical, which is adsorbed by the alpha-chymotrypsin. It has been shown that under the conditions used the probe is fixed on the rotating diffusive protein monomer. Theoretical calculations of possible rotation correlation times for alpha-chymotripsin molecule were performed taking into account hydration and non-spherical shape. Experimental data obtained are in good agreement with theoretical values.

Chemical Phenomena↗
PubMedDate not supplied

[Binding of spin-labeled palmitic acid by bovine serum albumin].

Investigation of the binding of spin-labeled palmitic acid and its esters with bovine serum albumin is presented. Both probes are shown to bind strictly to strongly and loosely binding centers of protein. The quantitative study allows to determine the binding constant and number of protein binding sites. It is found that the total binding constant for esterified derivative is several times as much as that of palmitic acid.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

[Rotatory mobility and intermolecular reactions of serum albumin studied using the spin-probe method].

Dependence of the rotational mobility of bovine serum albumin on the protein concentration in solution has been studied by means of nitroxyl radical tightly bound to the protein. The rotational correlation time of radical, bound with protein for weak solution has been compared with the theoretical values of correlation times for protein monomer, calculated in terms of its hydration and deviation from the spherical shape. A conclusion about radical orientation relatively to the protein molecule has been drawn from this comparison. The concentration dependence of ratational correlation time for radical, bound with protein, was explained by the protein dimerization in solution. A conclusion has been drawn about the stability of intramolecular structure of serum albumin during its dimerization on the basis of the stability of anisotropic hyperfine constants of adsorbed radical.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

[The quasi-resonance dependence of the arrhythmogenic action of a low-frequency magnetic field on myocardial contractile activity].

Non-monotonous quasi-resonance dependences of arising of arrhythmias on frequency and tension of magnetic field have been studied. Maximal effect was observed at 0.15 E and 40 Hz with 70% probability of the effect. The data obtained suggest that quasi-resonance effects of action of low-frequency magnetic fields are not limited to brain tissue and are mediated by the induced electric field.

Animals↗
PubMedDate not supplied

[The lack of the effect of a strong constant magnetic field on isolated membrane preparations of Na,K-dependent ATPase].

Effect of constant magnetic field (CMF) with induction 10 T on membrane preparations of Na,K-dependent ATPase of bovine brain (lipoproteid vesicules with 300-500 A diameter) were studied. No CMF effect on the activity of Na,K-dependent ATPase was observed under different experimental conditions (three temperature points 15, 20 and 37 degrees C and great variation of Na+,K+ concentrations ratio). CMF also produced no effect on the preparations of Na,K-dependent ATPase immobilized by adsorption on millipore filters.

Animals↗