A study was made to understand how an increase in lung volume depends on the level of high-intensity low-frequency sound at the resonant frequency of the respiratory system. Experiments were conducted in 16 rabbits. A modified two-microphone technique was used to measure the resonant frequency of the respiratory system in a frequency range from 5 to 100 Hz with a 3-Hz increment. With the resonant frequency known, a tone signal was delivered to the lungs at this frequency and the sound amplitude was varied from 120 to 138 dB. Measurements showed that the resonant frequencies of the respiratory system decreased by 13% on average, which corresponded to a 33% increase in lung volume due to the opening of the alveolar oxygen reserve. The observed phenomenon of an increase in lung volume upon stimulation with a high-intensity sound signal at the resonant frequency can be used to enhance the efficiency of bioacoustic stimulation of human lungs in order to increase the volume of the respiratory system.

Despite significant progress in the treatment of burn pathology, mortality in this pathology can exceed 50% when more than 30% of the body area is affected due to the development of multiple organ dysfunction syndrome. This review examines the most important molecular biological mechanisms of the development of multiple organ dysfunction syndrome via free radical destruction of plasma membranes, mitochondria, secondary production of free radicals by damaged mitochondria, modification of mitochondrial DNA and its use as a trigger of inflammatory processes in peripheral organs and systems. Secondary changes in the blood lipid transport system and their role in the generalization of multiple organ dysfunction and hormonal imbalance are considered. The use of antioxidants, in particular quinones, in combination with lipid metabolism modulators to reduce the activity of the inflammatory process and hormonal imbalance in the treatment of burn pathology is justified from the perspective of pathogenetic shifts in metabolism.

The survival rate of mice irradiated with accelerated carbon ions (450 MeV/nucleon) at the Bragg peak or X-ray radiation at a dose of 6.5 Gy was determined; the levels of DNA damage (%TDNA) in mouse blood leukocytes a day before and 1–23 days after carbon ion irradiation as well as 1–28 days after exposure to X-rays at the same dose were determined using the comet assay. A more pronounced damaging effect of carbon ions compared to X-rays was found according to the criteria of survival rate and %TDNA, as well as significant variations of %TDNA in individual animals, which, apparently, can cause individual differences in the development of genome instability in the long term. It was assumed that a higher %TDNA of leukocytes after carbon ion irradiation compared to X-ray radiation, its greater range and the lack of synchronicity of changes in individuals during the radiation period were associated with the occurrence of cluster damage in DNA and mitochondrial dysfunction, as well as due to genetic and epigenetic factors. These results indicate the need to assess by the comet assay the state of leukocytes in the blood of animals with a heterogeneous genetic background before irradiation to form a group with close values of %TDNA. The revealed differences in individual laboratory animals require further study to improve animal models in the perspective of the development of personalized biomedicine.

This paper presents a spatio-temporal model of greenling dynamics during prespawning and spawning mass migrations. The developed model is based on original verified long-term observations and data on industrial fishing in the Peter the Great Bay (the Sea of Japan); the equations describing the dynamics of the density of males/females and the mass daily movements of fish are written in terms of transfer equations. These equations are written in the form of modified Patlak–Keller–Segel equations, according to which the flow of objects/substances is directed along the gradients of the stimuli introduced. Presumably, in the prespawning season, the fish undergo adaptation to the subsequent rather long and energy-consuming spawning, both on the morphophysiological (including biochemical thermoregulation and a number of other endogenous processes) and behavioral levels, while the stimulus for mass migrations of the fish is optimal environmental conditions for spawning events. During the spawning period, the stimulus causes a search for convenient and well aerated ledges in the near-coastal area of the reservoir bed. Stimuli-related activity was modeled based on the information about the preferred water depths of the prespawning area and the relevant features related to selection of suitable spawning sites. It is assumed that the intensity of daily migrations is proportional to the linear size of the fish (the larger the fish becomes, the faster it moves). The equations for the spawning stage take into account the spatial competition of males, which is observed under natural conditions only in the vicinity of spawning areas. Away from these areas, males continue to search for new sites good for the spawn. For females, their movement is provoked by males that assembled in schools, the signal of which can be certain chemical elements released by males (for example, mucus secretion from males) or visual contact. Diffusion of the fish distribution and viscosity of the habitat (velocity diffusion) are taken into account. The initial distribution of fish is given according to the distribution of fish in July in the Peter the Great Bay averaged over a long-term observation period.

Meconic, comenic, chelidonic, and kojic acids are the main representatives of gamma-pyronic acids. It was found that comenic acid has a neuroprotective effect, and chelidonic acid has a pronounced anti-inflammatory effect. The neuroprotective effect of meconic acid has not been explored. The aim of this study was to investigate the neuroprotective potential of meconic acid on an in vitro ischemic stroke model, as well as on the basis of its physicochemical properties. A primary neuro-glial culture was obtained from the cerebellum of 7- to 8-day-old Wistar rats by mechanical dissociation. The protective effect of meconic acid on the culture of cerebellar neurons was studied using a model of glutamate toxicity and oxygen–glucose deprivation. The antioxidant activity of meconic acid was studied by quantum mechanical calculations and experimentally in the citrate-phosphate-luminol model system by chemiluminescence analysis. The chelating properties of meconic acid with respect to Fe3+ in solutions were studied by the Job’s method. Meconic acid has been found to have a protective effect on in vitro models of ischemia. It caused a decrease in the level of intracellular calcium and restoration of the membrane potential of mitochondria in the culture of cerebellar neurons under glutamate exposure and an increase in the percentage of living cells under oxygen–glucose deprivation. Meconic acid had a high calculated antioxidant potential, as was confirmed experimentally. With an increase in pH of the medium, a stepwise binding of meconic acid with Fe3+ occurred with the formation of complexes of different ligand/metal ratios. At physiological pH, the resulting complex had a composition with the ratio 1 : 3. The revealed antioxidant, chelating, and cytoprotective effects of meconic acid provide a basis for further study of the possible neuroprotective properties of this compound in experiments in vivo; the data on its physicochemical properties can be useful for the synthesis and study of new coordination compounds based on this acid.

The presented modification of the method of local optical tomography makes it possible to study the dynamic processes of subcellular structures of native nerve cells. The advantage of this approach is that it is possible to analyze the dynamics of the distribution of neuron structures at a point or area of interest inside the cell without performing a complete reconstruction of the cell image. It has been proved that it becomes possible to determine the dimensions, the cell area of interest, and the coordinates of subcellular structures for further study of their dynamics. In this modification, the method of local tomography could be used to study both cells and cellular structures, because it is not necessary to probe a full field of view. Local probing of the region of interest during the functioning of the nerve cell will, first, reduce the time of data recording for obtaining local tomograms and second, provide the opportunity to explore the dynamics of several regions inside the cell at the same time.

The main function of the PsbO protein in photosystem II is to stabilize the water-splitting Mn4CaO5 cluster. The present study shows for the first time that short-term exposure of both isolated and membrane-bound PsbO to UV light led to protein dimerization. A non-covalent dimer of the PsbO protein was detected by gel filtration. Separation of proteins of UV-irradiated PSII membrane fragments by polyacrylamide gel electrophoresis was indicative of the formation of covalent PsbO dimers, as with the isolated PsbO protein. The formation of covalent PsbO dimers following exposure to UV light supports the hypothesis that non-covalent PsbO dimers exist in vivo and may play a regulatory role in PSII.

The electrokinetic potential of isolated cell nuclei obtained from wheat seedlings irradiated with nonionizing electromagnetic radiation of extremely high frequencies has been studied. Electrokinetic potential is an important factor in many biological processes and, perhaps, plays an important role in the formation of the response of biological organisms to electromagnetic waves. An increase in the absolute values of the electrokinetic potential of isolated cell nuclei of wheat seedlings from –7.7 to –131.6 mV in the electric field gradient under the influence of electromagnetic radiation of extremely high frequencies, in the frequency range of 46.0–50.3 GHz, was shown. Unidirectional changes in the electrokinetic potential under the influence of such radiation have been revealed; it was explained by an increase in the potential difference between the nuclear membrane and the nuclear matrix. It was also shown that there were sharp differences between the electrokinetic potential of isolated cell nuclei treated with electromagnetic radiation of extremely high frequencies under in vivo and in vitro conditions. It was found that the magnitude of changes in the electrokinetic potential of nuclei induced by exposure to electromagnetic radiation of extremely high frequencies under in vivo conditions far exceeded the magnitude of the electrokinetic potential of isolated nuclei treated with electromagnetic radiation of the same frequency under in vitro conditions; this confirmed the prolonged effect of electromagnetic radiation of extremely high frequencies. The authors discuss the modulation of the electrokinetic potential depending on the change in the difference between the content of anionic phospholipids in the nuclear membrane and the soluble nuclear fraction arising under the effect of electromagnetic radiation of extremely high frequencies, which leads to a change in the surface charge of the nuclear membrane, the electrokinetic potential of the nuclei, and the formation of a more compact double electric layer.

The three-dimensional (3D) architecture of the genome determines cell function. The study of DNA condensation in the cell is important for understanding the mechanisms of bacterial survival and for medicine, since ordered DNA condensation provides antibiotic resistance to pathogenic bacteria . In a dilute solution, the length of DNA is several centimeters. The length of an Escherichia coli bacterium is approximately 2.0 μm. Such a dramatic decrease in the volume occupied by DNA is a consequence of its condensation. It was found that DNA is hierarchically organized in the nucleoid with three levels of DNA compaction: the lowest level (small scale ≥1 kb bp) is provided by histone-like NAP proteins. Unlike actively growing bacteria, bacteria under starvation stress use an energy-independent mechanism to maintain the order and protect vital structures (DNA), as in inanimate nature. The study of the DNA structure in the nucleoid of E. coli bacterium was carried out using synchrotron X-ray diffraction and transmission electron microscopy. The experimental results allowed visualization of the structures of the lowest hierarchical level of DNA compaction in the nucleoid of dormant cells. The series of diffraction experiments performed for the first time indicates the presence of a periodic ordered organization of DNA in all studied bacteria. The transmission electron microscopy provided more subtle visual information about the type of DNA condensation in the nucleoid of E. coli bacterium. Intracellular nanocrystalline, liquid-crystalline, and folded nucleosome-like structures of DNA were found. A folded nucleosome-like structure was observed for the first time, it is a result of multiple folding of long DNA molecules around Dps protein and its associates.