Vol 64, No 6 (2019)

The results of long-term observations and monitoring of three reservoirs of Zvenigorod Biological Station of Moscow State University using modern chlorophyll fluorescence methods are presented. A sharp increase in chlorophyll content (up to 431 μg/L) and photosynthesis activity (F_V/F_M up to 0.7) associated with the growth of a monoculture, Chlorella vulgaris, was found in 2017 Pozharnyi Pond pond constructed near University dormitory facilities. The high activity of light reactions of this phytoplankton was evident as changes in the following parameters: the maximum quantum yield of primary photochemistry in photosystem II (F_V/F_M), the maximum relative electron transport rate (ETR_max), maximal light utilization coefficient (α), the efficiency of electron transport (φ_Eo) and the performance index of photosystem II (PI_ABS) increased. This was accompanied by a decrease in the density of Q_B-non-reducing centers (V_J) and dissipated energy flux per reaction center (DI₀/RC). The most sensitive parameters of fluorescence induction curve (PI_ABS and φ_Eo) and the coefficient of maximal light utilization coefficient (α) are proposed to monitor the state of phytoplankton in reservoirs.

In this paper, we present the most important principles of diode laser spectroscopy, which allow one to create fundamentally new measuring systems for diverse applications in biology and medicine. Using the diode laser spectroscopy method and its primary hardware implementation the emission of gas molecules from skin of the hand was registered and ammonia skin emission was found to be dominant. The properties of exhaled air from patients in different states were determined with another special measuring complex of diode laser spectroscopy. It was shown that when the functional state of the body changes, the gas composition of molecular substances that are present in the exhaled air is altered indirectly and their levels vary significantly depending on the health of the individual. Our findings suggest that it is possible to study the specific functional properties of the human body to facilitate assessment of the health of an individual to determine whether pathological processes occur in the body at various stages of their severity using diode laser spectroscopy. This paper presents clinical and experimental data on this issue.

This paper provides a brief overview of the modern and classical virus detection methods, including virus detection with bacteriophages as an example. Attention is given to the use of screening methods for virus detection in the analysis of large numbers of samples, which can help avoid serious costs in the detection of viruses. One of the fastest growing directions in microbiology is the development of biosensor methods for virus detection, including those based on electrophysical analysis methods. The interest in biosensor systems for virus detection in aqueous solutions is due to their simplicity, rapidity, cost-effectiveness, and relatively high sensitivity. The promise is shown of the use of electro-acoustic sensors in the development of biosensor methods for virus detection.

Ordered nanostructures of porin from the outer membrane of Yersinia pseudotuberculosis (YpOmpF) were formed in two ways: from proteoliposomes and by direct protein reconstitution in the pre-deposited phospholipid bilayer on mica surface. The morphological analysis of the structures was performed by atomic force microscopy. It was shown that the efficiency of formation, the degree of homogeneity, and the size of porin domains substantially depend on the experimental conditions and the presence of lipopolysaccharide in a porin sample or in the bilayer. It was found that using proteoliposomes resulted in formation of the aggregates of porin nanodomains on the mica surface, with uneven distribution in the bilayer and quite different size ranges (50–250 nm). In the case of direct reconstruction of porin, it was shown that a decrease in pH of the solubilizing buffer promotes the inclusion of a sufficiently large amount of protein as homogeneous domains with an average size of 35–40 nm but does not lead to the formation of extended nanostructured regions in the bilayer. The most efficient incorporation of porin into the lipid bilayer with the formation of clusters of tightly packed protein domains was achieved using a porin sample in combination with peptidoglycan and lipopolysaccharide, which this protein is tightly bound to in the native bacterial membrane.

A study was conducted to evaluate the biochemical and cytogenetic parameters in peripheral blood lymphocytes in participants in the Chernobyl accident liquidation who were exposed to external and internal radiation in the dose range (0.1–70 cSv) and children living in territories with different levels of radionuclide contamination (1–20 Ci/km²) as a result of the Chernobyl accident. The effects of low-intensity radiation were studied in a comparative analysis of the relationship between the chromatid break index, the rate of mutagenesis in somatic cells (lymphocytes), and the level of reduced glutathione in blood plasma. The increased frequency of chromatid breaks in lymphocytes and an increased level of reduced glutathione in the blood plasma in children and liquidators exposed to low doses of radiation (0.1–20 cSv) were found to be statistically significant compared to the control. As the radiation dose increased (20–70 cSv), the increase in cytogenetic abnormalities in the peripheral blood lymphocytes of liquidators and children from Chechersk (Gomelsk oblast, Belarus) was accompanied by a decrease in the water-soluble antioxidant level in the plasma. The data on the relationship of the reduced glutathione level with the major indices of the cytogenetic status are important for identification of later pathological health-related conditions in people exposed to chronic ionizing radiation.

The cytotoxic effect of the antitumor drug aurumacryl (gold polyacrylate) against human tumor cells of various origins has been studied. It has been shown that aurumacryl exhibits significant cytotoxic activity against cells of lung carcinoma А549 (IC₅₀ = 60 μg/mL), melanoma Mel-mо (IC₅₀ = 80 μg/mL), and breast carcinoma MCF-7 (IC₅₀ = 90 μg/mL), while being substantially less efficient against colon carcinoma НСТ116 cells (IC₅₀ = 180 μg/mL).

A meta-analysis of the functional states of mitochondria was carried out using a mathematical model based on changes in the direction and speed of thermodynamic (TD) and electrochemical (EC) parameters (pressure, volume, temperature, entropy, Gibbs potential, exergy, etc.), which are interrelated. A mathematical model of the TC and EC cycle of mitochondria was constructed using the basic principle of supramolecular functional interactions. The model describes the TD and EC reactions that occur in the mitochondrial matrix–inner membrane–intermembrane space system and are accompanied by an accumulation of electrochemical potential and charge separation (ionization). Four functional states of mitochondria were studied in the situation where the speed and direction of electron movement along the respiratory chain changed in the thickness of the inner membrane in association with fluctuations in heat flow. The TD and EC cycle of mitochondria is a continuous succession of transitions between quasi-static states, in which quasi-equilibrium states change recurrently, displaying typical coherent stability of non-equilibrium processes according to I. Prigogine. The mathematical model of the TD behavior of mitochondria and the limitations imposed by laws of physical and chemical thermodynamics indicate that the highest degree of TD efficiency in the process of mitochondrial respiration corresponds to the state where Gibbs energy and exergy are at a minimum and entropy is at a maximum; the functional state was consequently identified as a basic one.

A conventional generator of periodic oscillations can be used as an amplifier of periodic noise. Sudden changes in generator frequency were observed during experiments and corresponded to so-called Arnold tongues. Arnold tongues are known to arise in a region where a periodic process is synchronized by a periodic external forcing. The experimental findings were assumed to demonstrate that the forcing actually exists; i.e., there was a periodic process that affected the generator frequency. This hidden periodic process belongs to the so-called universal period-tripling system (UPTS). The UPTS has repeatedly manifested itself on an indirect basis, by adjusting a variety of technical, astronomical, physical, geophysical, biological, etc., periodic events to forcing. The existence of the UPTS should be taken into account, in particular, when designing and debugging technical devices, including those for medical purposes.

Using noninvasive piezopulsometry, the dynamic structure of the arterial pressure waveform was studied upon exposure of the human cardiovascular system to short-term hypoxia. A strained breath-hold (SBH) after deep inspiration was used to induce short-term hypoxia. The pulse wave velocity (PWV) was reduced by 8% during a SBH. The arterial stiffness was observed to significantly decrease during a SBH.

Variations in the electrical conductivity of distilled water were studied experimentally at constant water temperatures. When the concentrations of major ions in water remained constant, proton mobility was found to display daily variations with a coefficient of variation reaching 15% of the initial value. The amplitude of the variation was observed to depend on the water temperature. Possible mechanisms of the observed effects are discussed.