This article considers the antifibrotic properties of pyrimidine derivatives of the drug Xymedon (compound (I)) and its conjugate with L-ascorbic acid (compound (II)) in an experimental rat model of fibrosis with a preventive administration scheme.

Experimental fibrosis was induced in Wistar rats given carbon tetrachloride (5% oil solution, 0.2 mL/kg orally twice a week) in combination with ethanol (5% solution in drinking water, free access) against compounds (I) and (II), both administered preventively. Fibrotic changes in the liver were detected by Van Gieson’s staining. The effects of the studied compounds on the liver and clinical condition of rats were evaluated through serum biochemical parameters.

The treatment of rats with compounds (I) and (II) reduced the number of fibrotic areas threefold, ameliorated hepatic steatosis and necrosis as compared to the control group, and improved blood biochemical parameters (ALT, AST, and LDH). Interestingly, compound (II) had a more pronounced effect.

Therefore, pyrimidine derivatives of Xymedon and its conjugate with L-ascorbic acid showed an antifibrotic effect in our experimental rat model of fibrosis.

The effects of acrolein and crotonaldehyde on the health of Russian smokers upon switching to heated tobacco product use were analyzed in a five-day randomized clinical trial. The findings suggest that heated tobacco products significantly reduce exposure to these toxicants, with the adverse effects becoming less pronounced in just one day and comparable to complete cessation of smoking. The dynamics of nicotine intake and metabolism in the smokers who switched to heated tobacco products remained stable throughout the study and was similar to that in the group of regular cigarette smokers.

Therefore, our study, which has been performed for the first time among the Russian population, shows that smokers switching to heated tobacco products are less exposed to harmful chemicals like acrolein and crotonaldehyde and thus may be protected against some of the negative health effects often associated with regular cigarettes.

Neuroglobin (Ngb) is a member of the globin family. Like other globin proteins, it is involved in the maintenance of oxygen homeostasis. Ngb distribution in the normal brain is well known, but its response to pathological injury, such as cerebral ischemia, has not yet been adequately elucidated. One primary reason for this is that ischemic lesions in cerebral tissues have mostly been studied in transgenic organisms. In addition, the available data on Ngb content are limited to a small number of brain structures. This article examines the patterns of changes in Ngb immunoreactivity in neurons from different parts of the rat brain after subtotal cerebral ischemia of varying duration. An immunohistochemical study of Ngb content in 25 brain structures of white male Wistar rats exposed to 30-min and 3-h subtotal cerebral ischemia was performed. A decrease in Ngb content in all structures (especially 3 h after the ischemia onset and in the phylogenetically older parts), temporal mediation, and dependence on the phylogenetic age were revealed. The obtained results further decipher the correlation between the changes in Ngb content and the degree of cerebral ischemic damage, which is necessary to clarify the functions of the studied protein.

Mesenchymal stromal cells (MSCs), a population of progenitor cells in adult tissues, are involved in the processes of physiological tissue renewal and damage-induced regeneration. MSCs have been widely studied as regenerative medicine agents. In this regard, the tissue-specific features of MSC subpopulations should be taken into account. MSCs have many potentially beneficial properties that can alter significantly with age. The ability of a cell to respond to external signals and regulate its functional state is commonly attributed to the repertoire of receptors on the cell membrane. This article considers the surface marker expression of senescent adipose-derived MSCs (AD-MSCs). Replicative senescence was caused by long-term cultivation. An increase in the expression of CD29, CD44, CD54, CD73, CD90, and HLA-ABC on the AD-MSCs was shown. The expression of CD105 and CD51/61 did not change reliably under the experimental conditions. The revealed effects are related not only to the larger cell size or higher autofluorescence, but also to the increased number of markers per unit area of the cell surface. The detected changes may underlie a number of modifications in the properties of senescent MSCs, including migration, adhesion, and immunomodulatory and angiogenic activities.

Microorganisms play an important role in the growth and development of a plant throughout its entire life cycle. Recent advances in the methods of molecular biological analysis have expanded our understanding of the composition and functions of plant microbiota (epiphytic, rhizosphere, and endosphere) and the molecular mechanisms associated with specific processes that govern plant-microorganism interactions. This article reviews the types of plant microbial communities, their sources of origin, and species composition, as well as the critical role they play in modulating the plant immune response against phytopathogens, improving the elemental nutrition of plants, scaring away herbivorous animals, producing phytohormones, and enabling plants to thrive under extreme environmental conditions.

In this study, variations in the levels of oil hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants generated by human activities, were assessed in the bottom sediments of the Caspian Sea (Russia) sampled from 2012 to 2021. The samples were analyzed for their chemical composition. The concentrations of the identified compounds responsible for hydrocarbon pollution were established. The quantitative results of the industrial environmental monitoring in the Russian sector of the Caspian Sea for subsoil use were also reviewed and processed by standard statistical methods. It was revealed that ΣPAH concentrations in the Northern and Middle Caspian Sea regions vary from analytical zero to 186.7 µg/kg and from zero to 467.8 µg/kg, respectively. The scale of oil pollution in these two regions was found to be determined by the following PAHs: phenanthrene, acenaphthene, and naphthalene. The origin of the listed PAHs provides vital information on the main sources of pollution of the Caspian Sea bottom sediments with hazardous organic substances. Based on the obtained data, the areas with background PAH pollution of the bottom sediments and those with the characteristic PAH of mainly natural and pyrogenic origin were located. 

Dynamic chaos systems are commonly described by the nonlinear cyclic Verhulst relation. In this study, its use was extended to track the degradation of ecological systems at different stages of their development. A new concept was introduced: the geochemical entropy of abiotic ecological systems, which varies in the interval [0, 4] and determines the level of their stability in the interval [0, 1]. The model was verified by assessing soil pollution in Lipetsk (Russia). Despite the high level of soil pollution in certain areas of the city, the overall ecological situation turned out to be “normal” with a high level of stability (0.98). Forecasts were made of how the ecological situation in Lipetsk might develop with a change in the anthropogenic load. If it remains unchanged, the sustainability of the ecological system will be virtually the same. With heavier soil pollution, the stability may be lost at different rates, depending on the entropy of the system. The proposed model is helpful for assessing the current geo-ecological state of large territories with high anthropogenic load and pollution levels varying considerably between different areas of these territories, as well as for predicting the level of living comfort in urban agglomerations and managing ecological systems.

Quartz grains were separated by standard sieving of the Paleogene sands from the Sosnovka Formation of the Ulyanovsk-Syzran Volga region, which are a scarce and valuable raw material for glass making and construction. In order to establish the origin of the sands and restore the facies conditions of their formation, the surface microtextures of the separated quartz grains were examined by optical and electron microscopy. It was shown that the clastic grains of the Sosnovka sands bear the signs of a multi-stage formation process under the conditions of subaquatic (beach zone), eolian, mixed subaquatic-eolian (coastal dunes), injective, and continental pedological settings. For the first time, a complex of microtextures characteristic of the extrusion of grains from deep horizons under pressure and inherent in the injection   mechanism of sand formation was described. The diagnostic complex of injectites includes rotational   microtextures, notched microtroughs, and deformed fluid inclusions. The rather fresh appearance of the listed microtextures suggests that they were superimposed on the coastal-marine and eolian stages of the evolution with the subsequent formation of sand intrusions. At the final stage of the geological history of the Sosnovka sands, the grains were shaped by the continental pedological conditions, when secondary silica in the form of globules and their clusters cemented the quartz grains, the surface of which concatenated the features of the previous stages. Based on the results of the study, an interpretation scheme summarizing various microtextural features of the reconstructed paleoenvironments and the stages of formation the Sosnovka sands was developed. The finding that the Sosnovka sands are sand intrusions is of great practical importance, as it necessitates new approaches to the discovery and prediction of glass and quartz sand deposits confined to the Paleogene Sosnovka Formation of the Ulyanovsk-Syzran Volga region.

An extensive collection of fossil brachiopods, all assigned to the Wuchiapingian Stage, was recovered from the lower part of the Imtachan Formation along the Ustupnyi Creek (right tributary of the Setorym River) in the Southern Verkhoyanie. It comprises strophalosiids (Strophalosia? aff. vollossovitschi (Fredericks), Strophalosia? sp., Subtaeniothaerus lungersgauzeni Solomina, Marginalosia? magna Abramov et Grigorjeva), spiriferids (Crassispirifer monumentalis Abramov et Grigorjeva, Crassispirifer cf. monumentalis Abramov et Grigorjeva, Crassispirifer sp.), athyridids (Cleiothyridina nikolaevi Grunt, Cleiothyridina sp. 1, Bajtugania sp.), and terebratulids (Marinurnula? aff. mantuanensis (Campbell), Marinurnula? sp.). The identified assemblage is associated with brachiopods from the lower part of the Khalpirki Formation of the Western Verkhoyanie, the appearance of which marks the boundary between the Dulgalakhian and Khalpirkian Regional Stages and also substantiates the lower boundary of the Crassispirifer monumentalis Zone. Single finds of Crassispirifer cf. monumentalis in the lower part of the Middle Imtachan Subformation indicate that the entire lower subformation and the lower part of the middle subformation belong to the C. monumentalis Zone. There are no reliable finds of brachiopods at higher levels of the Imtachan Formation.