Studying the mechanisms of age-related changes in vascular reactions and applying the acquired knowledge in the clinic can help reduce complications and mortality from diseases of the cardiovascular system, the frequency of which increases with age. This study is important because with aging, endothelial dysfunction increases and cerebral circulation disorders caused by the occurrence of ischemic foci are observed. One of the main elements in the regulation of vascular tone, along with many important mechanisms, are potassium ion channels. In this work, we studied age-related changes in the role of calcium-activated potassium channels (BKCa) in acetylcholine-mediated dilatation of cerebral arteries in Wistar rats, since their contribution to vasodilation in aging is poorly understood. Using intravital microphotography (×470), we compared the responses of pial arteries to acetylcholine chloride (ACh, 10-7 M, 5 min) in the absence and against the background of BKCa blockade with tetraethylammonium chloride (TEA, 2 mM, 5 min) in aged Wistar rats 4, 6, 9, 18 and 24 months. Changes in the contribution of BKCa to vascular dilatation were assessed by changes in the number of dilatations of the pial arteries on the exposure to ACh after BKCa blockade, measuring the width of vessels in 3 separate groups of arteries: small (with a diameter of less than 20 μm), medium (20–40 μm) and large (more than 40 μm). It has been shown that ACh-induced dilatation depends on the initial diameter of the arteries. Inhibition of BKCa activity in 4-month-old rats reduces the number of ACh-induced dilatations in all groups of arteries studied. Compared to 4-month-old rats, in 6- and 18-month-old rats the contribution of BKCa channels to the dilatation of small arteries is reduced, in 9- and 24-month-old rats the contribution of BKCa channels to the dilatation of medium arteries is increased; the contribution of BKCa to the dilatation of large arteries decreases starting from 6 months of age. Dilatation of the pial arteries of Wistar rats at the age of 4–24 months depends on the initial diameter of the vessel. BKCa play a significant role in ACh-mediated dilatation of these vessels. Age-related impairments in the contribution of these channels to ACh-mediated dilatation of pial arteries develop gradually, have a wave-like course and depend on the diameter of the arteries. The identified disturbances in the functional activity of the BKCa can serve as therapeutic targets for the creation of new technologies for the treatment of age-related lesions of cerebral vessels.

Increasing volumes of produced antiseptics and disinfectants, which are widely used in medicine, veterinary medicine, the food industry and everyday life, can create a serious environmental problem after use. Previously, under the influence of micromolar concentrations of a number of antiseptics, we identified disturbances in the functioning of photosynthetic membranes and phototransforming pigment-protein complexes isolated from them in various representatives of photosynthetic organisms. In this work, to determine the sensitivity of photosynthetic membranes to the action of the cationic antiseptic octenidine, we used chromatophores of the purple nonsulfur bacteria Rhodobacter sphaeroides, labeled with the fluorescent dye 10-N-nonylacridine orange (NAO). It was shown that the binding of NAO to chromatophores is accompanied by a shift in the dye emission maximum from 525 to 640 nm. The “red” fluorescence of NAO associated with chromatophores turned out to be sensitive to the effect of increasing concentrations of octenidine on photosynthetic membranes. We have found antiseptic concentrations which led to the degradation of chromatophore structures and change in the NAO aggregative state. It can be detected by an increase of “green” fluorescence in the emission spectra of the dye. The properties of NAO as a fluorescent indicator of the functional state of photosynthetic membranes and possible changes that can occur in such systems under the influence of a cationic antiseptic are discussed.

The analysis of plant functional traits and strategies is the main direction to study the formation mechanisms of the composition and structure of plant communities. Comparison of the mean species trait values with a random sample of a local flora allows us to determine the importance of the trait for the plant community formation. Comparison of mean and weighted mean shows the role of the trait in dominance. The aim of this work was to study the role of leaf functional traits and the contribution of Grime’s CSR strategies in the formation of Calamagrostis subalpine meadows, which are the most widespread in the north-western Caucasus. The aboveground biomass in these communities is 384 ± 21 g/m2 (mean and standard error of the mean), the mass of litter of previous years is 393 ± 40 g/m2. The share of grasses in the community is 57,1 ± 2,9%, forbs – 32,9 ± 2,6%, legumes – 8,9 ± 1,4%, sedges and rushes – 1 ± 0,3%. The three species can be considered as dominants: Calamagrostis arundinacea (26,5% of the total phytomass), Festuca varia (23,3%), Hedysarum caucasicum (8%). The dominants of community have a high leaf dry mass, a lower leaf water content, a smaller specific leaf area. The community components are characterized by a lower mass of the water-saturated leaf and dry matter content, and a higher specific leaf area. Dominants and components in the community are characterized by a greater contribution of the stress-tolerant strategy.

In August 2023, a comprehensive expedition “Crillon 2023” was performed, covering both terrestrial and marine biotopes in the southeastern part of the Crillon Peninsula (Sakhalin Island, Russia). A group of specialists carried out field work in ichthyology, invertebrate zoology, entomology, botany, lichenology, bryology, mycology, parasitology, microbiology and marine biology. In the scarcely studied territory of the southeastern part of the peninsula, a notable amount of data on species diversity was collected, including more than 200 species of plants, 101 species of lichens, 74 species of mosses, 117 species of basidial macromycetes were recorded. Marine coastal communities of the littoral and sublittoral zones were studied, and diving methods were exploited. As many as 119 species of invertebrates and 20 species of seaweed have been recorded. Information was collected on 20 species of fish, including data on helminth infestation. Parasitological studies included the search for microsporidia in all available animal hosts, as well as the search for root crayfish – parasites of arthropods. Among the animals and plants found, there are rare and endangered species included in the regional and federal Red Books, as well as those previously not recorded for Sakhalin. The preliminary results obtained indicate great potential for further study of the eastern part of the peninsula from the standpoint of biological sciences, as well as the prospects for establishment a biological station in this area for long-term research and development

Carotenoids are one of the largest classes among biological pigments. They are found both in free form (dissolved in hydrophobic environments), and bound in stoichiometric complexes with protein (carotenoproteins). The interaction between the carotenoid and the protein environment is determined by the molecular conformation and dynamic behavior of the cofactor. In this work, using molecular modeling methods, we analyzed the entire set of alternative conformational states of cyclic carotenoids. The result of the theoretical study is an energysorted catalog of alternative conformational states for biogenic cyclic carotenoids and their optical isomers. The conformational states characterized in this study can be used to correctly select initial conditions when solving problems of molecular modeling of carotenoproteins

Species distribution modeling (SDM) allows to define the potential range and identify key factors that determine the habitat suitable areas. In this study, we made forecasts for the distribution of the European clausilid Cochlodina laminata (Montagu, 1803) in the eastern part of the range using SDM methods. Various algorithms are used to create models, including machine learning algorithms. We selected climatic factors and Earth remote sensing (ERS) data as predictors (extended vegetation index and land use). An ensemble forecast based on all models showed that the range of C. laminata is a wedge-shaped and largely coincides with the scheme proposed earlier by I.M. Likharev. However, in the eastern and southeastern parts the potential range turned out to be wider. The boundaries of the C. laminata potential distribution have been established in the forest-steppe and steppe zones, as well as in the Black Sea region and the Caucasus. The use of remote sensing data made it possible to identify suitable territories in more detail, which is especially important in the peripheral zones of the range. It is shown that the most significant factors in the distribution of the species in the studied area are the average annual temperature, temperature seasonality and precipitation of the warmest quarter

Neutrophil extracellular traps (NETs) are decondensed nuclear chromatin, decorated with bactericidal proteins of various cell organelles and performing an effector function aimed to combat pathogens at the site of inflammation. At the same time, NETs play an important role in the pathogenesis of many autoimmune and inflammatory diseases as well as malignancies. Rabbits are one of the most commonly used species of laboratory animals in medical and biological research. A large number of models of various diseases of the cardiovascular, immune and other human systems have been developed in rabbits. However, there is no information in the scientific literature about the ability of rabbit neutrophils to undergo NETosis in response to well-known pharmacological stimuli. The purpose of the present work was to study in in vitro system the ability of neutrophils of Soviet chinchilla rabbit to form NETs in response to mimetic of diacylglycerol phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. To isolate rabbit neutrophils, the one-step density gradient centrifugation on Ficoll-Hypaque method with modifications was used. Oxidative burst was assessed with luminol-amplified chemiluminescence method, and NET formation was assessed with immunofluorescence analysis. The work shows for the first time that neutrophils of Soviet chinchilla rabbit do not form NETs in response to PMA, but form traps in response to A23187, as well as have a low level of oxidative burst in response to PMA, A23187 and chemoattractant N-formyl-methionylleucyl- phenylalanine.

We studied the vitamins A (retinol) and E (α-tocopherol) content in the tissues of the bank vole (Myodes (Clethrionomys) glareolus) and common shrew (Sorex araneus) inhabiting the northern periphery of its range. The distribution of vitamin A in the common shrew and bank vole tissues was similar, the highest content was found in the liver, and the lowest level was in the heart. Agerelated differences in retinol content were detected in the kidneys of two species, as well as in the skeletal muscle of the shrew. Significantly lower vitamin E content was found in all organs of young shrews before wintering, compared to adult wintered animals, while in the bank vole no such age-related differences were found. Interspecies differences in the levels of vitamins A and E in the liver of overwintered animals were revealed. The results obtained show that vitamins A and E content in the tissues of the bank vole and the common shrew is determined by the metabolic processes and the ecological characteristics of the species. The vitamins level in the common shrew depends largely on age.