Biofeedback training and human functional state control

Biofeedback (BFB) training paradigm has outstanding place among various approaches to non-phrarmacological human functional state correction. Being an universal way for voluntary self-regulation of physiological functions, it is characterized by efficacy, accessibility and absence of side effects. However, the lack of fundamental knowledge about the BFB mechanisms leads to existence of numerous difficulties and problems that seriously limit the BFB possibilities. Most difficulties seem to concern the problem of adequate choice of BFB type or parameter being voluntary controlled via feedback signals. Some ways to solve this problem are drown on the base of general systems theory. It is shown that BFB procedures could be especially effective in conditions of close interaction between the BFB mechanisms and the central regulatory mechanisms. Such interaction could be reacheb by utilization of certain characteristics of brain electrical activity reflected in the electroencephalogram (EEG). The most perspective seems to be the utilization of discrete narrow band EEG spectral components, individual resonance EEG oscillators or some correlates of human EEG amplitude modulation processes.     

New photoreactive cleavable reagents with (trifluoromethyl)diazirine group

Photoreactive cross-linking reagents that simultaneously contain a trifluoromethyldiazirine and an o-nitrobenzyl groups were synthesized for the first time. Photochemical properties of the reagents were studied, and the possibility of separate activation of the diazirine group and o-nitrobenzyl linker was shown.     

Again about the Fine Structure of the α Rhythm of Human EEG: Two Spectral Components in the Resting State

In order to study the fine structure of the EEG frequency band in the resting state, two-minute segments of baseline EEG derived from symmetrical frontal, central, parietal, and occipital areas of 16 male subjects were analyzed by Fast Fourier Transform by successively increasing the analysis epoch from 2 to 20 s with 0.5-s steps. It was shown that the EEG band at rest is a heterogeneous complex of two independent components that differ in the frequency, on average, by 0.9 ± 0.2 Hz. These components can exist in the Fourier spectrum either simultaneously or independently of each other, which is determined by experimentally-induced and natural shifts in the functional state of the system. Doublets of these components can be located on the frequency axis in any part of the range. This finding does not allow the a prioridivision of the band into the classical ₁, ₂, etc. subbands.     

Evolution of spore release mechanisms in the saprolegniaceae (Oomycetes): evidence from a phylogenetic analysis of internal transcribed spacer sequences

Classical studies on spore release within the Saprolegniaceae (Oomycetes) led to the proposition that different mechanisms of sporangial emptying represent steps in an evolutionary transition series. We have reevaluated this idea in a phylogenetic framework using internal transcribed spacer sequences of four genera. These data were compared with the response to osmotic stress exhibited by each taxon. Saprolegnia emerges as the most basal genus, sister to Achlya, Thraustotheca, and Dictyuchus. Achlya and Thraustotheca are most closely related, while Dictyuchus appears to have evolved along a separate evolutionary lineage. The resulting phylogenetic framework is consistent with the idea that the mechanism of sporangial emptying exhibited by Saprolegnia represents the plesiomorphic condition from which the other mechanisms were derived independently. These alternative mechanisms of spore release may have resulted from a small number of mutations that inhibited axonemal development and altered the temporal and spatial expression of lytic enzymes that degrade the sporangial wall. Copyright 1998 Academic Press.     

Effects of chronic irradiation of Scots pine (Pinus sylvestris L.) in Chernobyl exclusion zone

The quantitative "dose rate-effect" dependences are presented for the cytogenetic damages in the seedlings and apical meristem of Scots pine growing in the Chernobyl zone. The specific patterns of dynamics of formation of the morphological effects in the studied species are considered for the conditions of the internal and external chronic irradiation. The correlation dependencies are established for the irradiation effects appearing at the morphological and cell level. The assumption concerning the mechanism of the morphological changes formation is done.     

Destruction of human blood cells upon interaction with detonation nanodiamonds in experiments in vitro

The influence of nanodiamonds synthesized by detonation on human red and white blood cells in vitro was studied. Nine nanodiamond samples produced by different manufacturers and two samples of modified nanodiamonds with high colloidal stability were used in the study. It was shown that nanoparticles cause the destruction of white cells and the hemolysis of erythrocytes. Possible mechanisms of the desctructive effect of detonation nanodiamonds on blood-forming elements are discussed.     

On the reactions of the human nervous system to complex-frequency optical stimulation

A computerized system for precise stimulation and analysis of electroencephalographic (EEG) reactions to two simultaneously presented frequencies of sine-wave light (one constant, 13 Hz, and the other varying from 1 to 6 Hz and vice versa) was used to study the mechanisms of human brain reactivity to complex rhythmical stimulation. The frequencies were generated by computer and presented to the subjects by three different ways: as a result of their simple summation (additively), as a product of their multiplication (multiplicatively, amplitude modulation of constant frequency by the varying frequency), or by separate presentation to different eyes. The dynamics of electroencephalograms for different types of stimulation were compared. Under all three experimental conditions, the dynamics of EEG spectra has demonstrated the same general pattern of resonance activation, which was similar to that observed for the presented signals in the case of their amplitude modulation. Significant positive shifts in the functional state of subjects were observed as a result of stimulation. The results obtained show the leading role of the processes of amplitude modulation in the interaction of integrative, adaptive, and trace mechanisms of the brain functioning during human perception of complex rhythmical stimuli.     

Utilization of feedback signals from patient's own endogenous rhythms for non-drug correction of human functional disturbances

The most advanced approach to non-drug correction of human functional disturbances via utilization of feedback signals from patient's own endogenous rhythms, i.e., EEG rhythms, respiratory and heart rate is presented and substantiated. The advantages of its application to biofeedback training procedures are reviewed. Alternative way to utilize the feedback signals through automatic modulation of stimulation parameters by patient's endogenous rhythms is analyzed. The author's own contributions to the field are presented and the most promising ways of further approach development are delineated.