Collagen is a biodegradable polymer with many beneficial properties, such as high biocompatibility with skin, excellent film-forming ability, antimicrobial and antioxidant actions, etc. It has received increasing attention in various research and practical fields for its potential applications. However, the use of collagen can be problematic due to its high molecular weight, which can be resolved by hydrolysis into smaller polypeptides. Efforts have also been made to find alternative sources of collagen and its hydrolysates. One such promising source is poultry by-products rich in type I collagen, the most important collagen for practical use. This article analyzes the physico-chemical properties of collagen hydrolysates isolated from the superficial soft tissues of chicken paws. The results obtained show that the use of Neutrase yields a hydrolysate that exhibits greater surface activity at the liquid-gas interface, enhanced wetting ability, and better adhesion to hydrophobic surfaces. Therefore, it can be recommended as a multifunctional ingredient for skin care cosmetics. A cream formula with collagen hydrolysate was developed. Cream is characterized as a multiple emulsion with a moisturizing effect.

This article reports the results of our study aimed at synthesizing and describing the structure and properties of new transition metal complexes with potential anti-tuberculosis and other related activities. For the first time, five bis-complexes of the ligand N’-(1-(6-methylpyridine-2-yl)ethylidene)isonicotinohydrazide (LH) with ions of five 3d metals (Cu(II), Mn(II), Co(II), Ni(II), and Zn(II)) were synthesized. The structures of all synthesized complexes in crystalline form were identified by X-ray diffraction (XRD) analysis. The resulting compounds were characterized by NMR, mass spectrometry, and electron spectroscopy. DFT/PCM calculations were performed on the structures of the five ML(OH) hydroxocomplexes formed during the hydrolysis of ML₂ complexes in an aqueous medium within the physiological pH range. The binding energies of the ML(OH) complexes with the biotarget, the InhA protein of the Mycobacterium tuberculosis strain, were determined by molecular docking. The data obtained suggest that the studied complexes have high biological activity and warrant further biomedical research.

Simple and rapid determination of Sudan I, a synthetic azo dye banned in the food industry over health concerns, is needed to ensure foodstuff safety and quality. In this study, a voltammetric approach based on Sudan I oxidation at the glassy carbon electrode (GCE) modified with manganese dioxide nanorods (MnO₂ NRs) dispersed in hexadecyl pyridinium bromide was developed. The effectiveness of MnO₂ NRs as a modifier was confirmed by a 7.9- and 9.2-fold increase in the electroactive surface area and the electron transfer rate, respectively, as compared to GCE. The irreversible electrooxidation of Sudan I was found to be accompanied by proton transfer and controlled by both diffusion and surface processes. Differential pulse voltammetry in phosphate buffer pH 6.5 was used for analytical purposes. The linear response of the electrode to Sudan I was shown in the ranges of 0.050–2.5 and 2.5–25 μM, with a detection limit of 13.5 nM. The developed approach was tested on dried and smoked paprika and Atlantic salmon. The obtained recovery values of 99–101% suggest that there is no matrix effect and that the method can be applied in practice.

Regulatory T (Treg) lymphocytes are a T helper population that controls the intensity of the immune response and maintains immune tolerance by selectively suppressing the activity of effector T lymphocytes. Treg cells are unstable and show high plasticity towards effector T helper populations, and the most common variant is Treg redifferentiation into T helpers producing interleukin-17 (IL-17 (Th17)). Although their formation has been confirmed by many studies in vivo and in vitro, Treg cells remain poorly understood in terms of their functional activity. The latter is yet fundamentally important for two major reasons. Firstly, an increase in the population of IL-17-producing Tregs has been identified for a number of diseases, raising the question of how these cells are involved in the development of pathologies. Secondly, understanding and predicting the behavior of Tregs in a pro-inflammatory environment promotes their therapeutic use. This review article analyzes the functional consequences of the redifferentiation of Treg cells into Th17.

This article reports the results of a study of Cr(VI) ions mutagenicity in the erythrocytes of Bufo viridis tadpoles under the influence of a low-frequency pulsed magnetic field (LF PMF). The tadpoles were randomly divided into 14 groups (n = 7). One group of intact tadpoles served as control. Other groups were experimental. The first six groups were placed for 24 h in water containing Cr(VI) at different concentrations (0.025, 0.05, 0.125, 0.25, 0.375, and 0.50 mg/L). The eighth group was subjected to an 8-h exposure to LF PMF (41 mT, 16 Hz). The remaining six groups of tadpoles were kept for 24 h in water with Cr(VI) ions at the specified concentrations and were also irradiated with LF PMF (41 mT, 16 Hz) during the first 8 h of this period. A day after the exposure, blood smears were taken, and the frequencies of micronuclei and nuclear anomalies in erythrocytes were analyzed. The results reveal that low concentrations of Cr(VI) (0.025 and 0.05 mg/L), unlike the higher ones (0.125 mg/L and above), did not significantly affect the frequencies of the analyzed anomalies. The combined action of Cr(VI) and LF PMF significantly increased the frequencies of the recorded anomalies in all the six variants of the experiment. The synergistic effect of Cr(VI) and LF PTF was shown.

The spatio-temporal variability of fresh groundwater composition was analyzed in four regions with different natural and technogenic conditions. The results obtained show no significant changes in the groundwater composition of the agricultural areas over the last 60 years. As for the industrial oil refinery zone, intense groundwater pollution was observed only in the nearby areas of sludge reservoirs and waste landfills. However, it did not extend further than 1.0–1.5 km in the direction of the filtration flows. This is partly due to the high buffer capacity of the geological environment. In the areas with intensive oil production, the composition of fresh groundwater changed most negatively over long distances. Depending on the temporal concentration gradients, the following four degrees of change in the groundwater composition were distinguished: extremely weak, weak, medium, and high. The latter two were typical of the central parts of the oil-bearing areas, with the groundwater mineralization in the upper part of the section reaching 10 g/L and the hardness of 70 mmol/L.

This article considers exchangeable potassium levels in the floodplain soils of the Amur River. The accumulation of exchangeable potassium in these soils was found to be largely determined by their age and weathering extent. In the young and highly weathered soils, the content of exchangeable potassium was lower than in the middle-aged soils. In the humus-accumulating horizon, it was 100–400 mg/kg and 200 mg/kg in the Upper and Middle Amur River, respectively. As for the mineral horizons, it ranged from 20 mg/kg in the young alluvial soils to 150 mg/kg in the residual-floodplain rusty soils. Interestingly, a significant increase in exchangeable potassium was observed for the coniferous-birch forests of the Upper Amur River (reaching an average of 400 mg/kg), but not for the oak forests in the Middle Amur River. Due to the asymmetry of the rate and ratio of zonal processes in the floodplain soils of the Upper and Middle Amur River, the residual-alluvial soils turned out to be sharply differentiated by the exchangeable potassium profiles. On average, the brown soils (Fluvic Cambisols) of the Upper Amur River contained up to 350 mg/kg of exchangeable potassium. The Fluvic Cambisols of the Middle Amur River had the lowest content of exchangeable potassium as compared to other studied soils.

The western coast of the Kaliningrad region (Russia) is known for its amber quarries. While one quarry is active, others, the Yantarny Pond and a chain of beach coastal quarries, have been flooded by the waters of subsurface horizons. This article explores objective factors behind seawater intrusion and infiltration into the flooded quarries through aquifers, which connect them to the coastal parts of the sea. Changes in the geomorphology and morphometry of the catchment surface due to quarrying were traced by analyzing the cartographic data and satellite images. The obtained results show a reduction in the size of the catchment area, shifts in the hydrological network, and the emergence of new water bodies. Three aquifers provide subsurface feed to the water bodies and discharge into the sea. They are also connected with the existing quarry and the water supply system of the Yantarny municipality. Hydrological field data reveal higher mineralization of the Yantarny Pond waters compared to other freshwater bodies in the study area, as well as a local near-bottom anomaly of highly mineralized waters. The water level of the flooded beach quarries is currently above sea level, but they have different salinities, indicating their transitional state from fresh- to seawater bodies.

The satellite imagery of the eastern part of the Stavropol region (Russia) was processed and analyzed for the spatial and temporal spread of fires, both landscape and field ones, and open sand massifs. Moisture distribution, anthropogenic transformation of the territory, climatic trends, and livestock dynamics were assessed. The agricultural and climatic zones were considered to reconstruct the fire dynamics. No direct relationship was revealed between landscape fire progression and desertification site development. While the advance of open sands naturally prevents the spread of fires, it also contributes to a decrease in the population of large and small livestock. This, in turn, leads to an accumulation of the mortmass and results in a higher fire risk. Our findings show that the areas of open sands increased more than 20-fold from 2013 to 2022, while landscape and field fires tended to become less extensive.

This article describes the status of the Caucasian rapid racerunner (Eremias velox caucasica Lantz, 1928) population on the Sarykum sand massif. Data collected on its sex-age structure in the first decade of May 2022 were analyzed. Morphometric diagrams based on body length measurements (mm) were built. The results obtained show that the population consists of immature specimens and mature males and females. Adult animals can be divided into two age groups, namely, lizards aged two years and three years or more. The core of the population is made up of immature and two-year-old males and females. Sexual dimorphism related to body length was reliably determined by the nonparametric Mann–Whitney test: males turned out to be larger than females. Although the population is generally stable, it is still negatively affected by the recreational load on the Sarykum territory and the sand overgrowth. These two factors lead to changes in the biotope inhabited by E. v. caucasica. Therefore, it is important to carefully monitor the population of E. v. caucasica on the Sarykum sand massif as this species is listed in the Red Book of the Republic of Dagestan and other southern regions of Russia.