A comprehensive analysis of the composition of the alluvium of the river with active gas–hydrothermal occurrences has been carried out for the first time. Common features in the lower and middle ...reaches of the Geysernaya River include poor roundness of boulders and pebbles (grades 1–2), poor grading of alluvium fine-clastic components, abundant rock fragments, and mineral intergrowths even in the fine-sand fraction. All this information is indicative of weak sediment disintegration and a high proportion of slope material in sediments, including that redeposited by mudflows. High contents of smectite–zeolite and other newly formed (secondary) mineral aggregates (up to 70% of the light fraction of 0.1–0.25 mm in size) and altered rock fragments (up to 70–80% in the pebble fraction of alluvium) make it possible to suggest a great effect of gas–hydrothermal activity on the processing of river-eroded rocks, as well as the secondary weathering of the alluvium within the thermal fields. The riverbed deposition is fragmentary and predominant in the areas of (1) the active slope material inflow (temporary dams), (2) flattening of the longitudinal profile in dammed reservoirs, and (3) mudflow material removal. Two dammed reservoirs formed over the past 15 years, as well as fine-sand layers in the low-terrace sediments are indicative of the fact that the Geysernaya River valley is characterized by the periodic formation of such short-lived basins. The deposition conditions of the fine-sand alluvium are different in sections of a single-branch channel and within dammed reservoirs and affect the ratio of the principal minerals of the heavy fraction. Abundant well-rounded gravel and coarse sand and their weathered appearance make it possible to assume that, along with the processing of large volumes of incoming slope and mudflow material, the Geysernaya River continues to cut in and to erode ancient fluvial sediments probably of the pre-caldera stage.
An analysis is made of the karst geomorphosystems of the Yucatán Peninsula. It is found that the main factors influencing its formation were climate and ocean level oscillations, tectonic movements, ...and impact effects. It is established that as a result of an active influence of the Maya civilization on the karst landscape of the peninsula, the geomorphosystems was transformed to the karst-anthropogenic system. The karstic landforms, and also the underground caverns experienced the anthropogenic impact, and the subsurface waters were particularly heavily influenced, which, on the one hand, determined the places of concentration of settlements and were actively consumed by the population, and, on the other, their reserves were replenished at regular intervals as a result of the creation of artificial subsurface water storages. In a further transformation of the karst-anthropogenic system, two stages were additionally identified: dominated by natural karstic processes (after the decline of the Maya civilization), and with a renewed intensification of anthropogenic pressure (1980s–current period). The last transformation stage is distinguished by an extension of the impact to the surface karst as well as to the underground caverns: they are subjected to mechanical destruction with an enhancement in the chemical impact as a result of inputs of polluted runoffs to encompass ever deeper horizons of subsurface waters. It is established that the rates of transformation processes of anthropogenic objects created of limestone are, in general, comparable with the mean rates of natural karstic processes on the neighboring territories: the formation of karrens on Maya steles is generally proceeding at the rate of 0.04 mm/year, while the growth rates of flowstones within urban structures of limestone vary from 0.03 to 0.6 mm/year.
The ubiquitin-proteasome system (UPS) controls the activity, subcellular localization, and stability of many cellular proteins that affect cellular homeostasis by regulating multiple signaling ...cascades. The activity of this system is associated with the emergence and progression of oral squamous cell carcinoma, since specific proteolysis of most intracellular proteins involved in the pathogenesis of cancer is implemented by this system.The review article presents data on the characteristics of proteasomes and the process of substrate protein ubiquitination. The role of the ubiquitin-proteasome system in the pathogenesis of oral squamous cell carcinoma is shown, and the prospects of its use in precancerous diseases are described. The literature search was carried out in the search engines Medline, eLIBRARY, Scopus, The Cochrane Library, and RSCI.
Background. Antigen-presenting cells (APCs), especially macrophages, play an important role in the body defense against various pathogens. Their dysfunction and polarization are associated with most ...inflammatory and autoimmune diseases. The inflammatory process is regulated by activation and / or inhibition of genes differentially expressed by macrophages. Successful correction of inflammation leads firstly to elimination of inflammatory stimuli and then to remodeling and restoration of tissues and organs. It was experimentally confirmed that silvercontaining bionanocomposites based on natural humic substances (HS) obtained from coal of different origin, as well as initial matrices of these HS, are capable of activating pro- and anti-inflammatory properties of macrophages.Aim. To study cytotoxic, pyrogenic, and immunomodulatory properties (arginine balance) of initial HS samples and samples of silver nanoparticles ultradispersed in these HS matrices (HS-AgNPs) in the cell culture of peritoneal macrophages, as well as their effect on pro- and anti-inflammatory properties of APCs.Materials and methods. Cultural and biochemical methods were used in the study.Results. The study showed that the samples CHE-K, CHE-AgNPs, CHS-K, and CHP-K increased M1 macrophage polarization due to stimulation of the NO-synthase activity and inhibition of arginase. The samples CHI-K, CHIAgNPs, CHP-AgNPs, and CHS-AgNPs modulated an alternative M2 or M2-like state of macrophage activation. At the same time, HS are not cytotoxic at effective concentrations, and three out of four studied samples did not contain pyrogenic impurities.Conclusion. The use of HS and their silver-containing bionanocomposites, which have the ability to greatly affect the polarization of antigen-presenting cells, is a promising research area in correction of the inflammatory response for solving an important social and medical problem of treating chronic wounds.
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