The features of the substance composition, physicochemical parameters and conditions of the formation of gold mineralization of deposits and ore occurrences with the silver-bismuth-tellurium mineralization in the Allakh-Yun metallogenic zone are reported. The ores were determined to contain 20 tellurium minerals: 10 tellurides, 6 sulfotellurides, and 4 tellurates, two of them are unidentified. Usually they form microand nanoinclusions 1–20 µm in size, except for the ores of the Oderzhimyi and Tenistyi deposits, in which the size of tellurobismuth and/or tetradimite reach 3 mm. Tellurium minerals of two systems dominate: Au–Bi–Te and Au–Ag–Te. Gold is present in association with tellurium telluride minerals: calaverite (AuTe₂), sylvanite (AuAg)₂Te₄ and petzite (Ag₃AuTe₂). Three types of gold and silver-bismuth-tellurium mineralization are revealed in the gold ore deposits of the Allakh-Yun metallogenic zone: Au–Ag–Te, Au–Bi–Te, and the mixed type, combining the mineralization of both system. A decrease in the fineness of gold corresponds to the sequence and temperatures of the formation of Te minerals and associating mineral parageneses from mesothermal Au–Bi–Te (830–999 ‰) to epithermal Au–Ag–Te (<600 ‰). The data on the characteristic of fluid inclusions allow us to relate Au–Ag–Te ores to low-temperature, Au–Bi–Te – to mesothermal; the highest temperature of ore formation is demonstrated by the mineralization of the Levodybinskiy ore cluster: 365–276 °C. Ynykchanskoye ore field, judging from formation temperature 200– 150 °C, possesses the features of epithermal mineralization. The mixed Au–Ag–Bi–Te (the Zaderzhninskoye deposit) mineral type is composed of heterogeneous solutions. The compositions of Pb isotopes in galena of the gold-polysulfide association of the Zaderzhninskoye in the diagrams composed in the coordinates ²⁰⁶Pb/²⁰⁴Pb–²⁰⁷Pb/204Pb and ²⁰⁶Pb/²⁰⁴Pb–²⁰⁸Pb/²⁰⁴Pb demonstrated the agreement with the corresponding data on the Nezhdaninskoye gold deposit, and the data on the gold–silver–tellurium association of the Ynykchanskoye ore field – with the silver-polymetallic objects of the Tyry-Dybinskiy cluster. Genetic and paragenetic association of Au–Bi–Te mineralization with granitoid magmatism is assumed, while Au–Ag–Te mineralization is assumed to be associated with alkaline magmatism. The formation of the gold-polysulfide mineral type of the Levodybinskiy cluster and the Zaderzhninskoye deposit proceeded synchronously with the intrusion of large granitoid plutons of the Southern Verkhoyan territory. The gold ore deposits and occurrences in the Allakh-Yun metallogenic zone have some similar features in their mineral composition with the Au–Ag objects of the Verkhoyan-Kolyma folded zone and the Okhotsk-Chukotka volcanic belt, Primorye, and are close to the Au–Ag–Bi–Te deposits of the Aldanian shield and Central Asia. The description of the Dzheruy, a compact highly productive Au–Ag–Bi–Te deposit which is at the start of its intense development in Kyrgyzstan, is presented as an example. The studies revealed that Au–Te mineralization is spread within the boundaries of the Allakh-Yun metallogenic zone. The Au–Ag–Bi tellurides are essential auxiliary minerals revealing the physicochemical conditions of ore formation in the deposits. Silver, tellurium and bismuth may also be extracted as accompanying components from several deposits.

The varieties of cleavage in the black-shale rocks of the northern part of the Ulakhan-Sis antiform (in the Tuoguchan and Tarbagannakh suites of the Upper Permian age) and some rocks stretching indicators in this part of the antiform are considered. In the reconstruction of the deformation processes, along with the ordinary geological methods, systematic microstructural observations of rocks in the thin sections under a microscope were used. The main sub-conformable cleavage S₁ and the role of pressure solution in its formation are characterized. The cleavage S₁ formation sometimes accompanied by the formation of a stretching lineation. In metasandstones the of quartz and plagioclase grains and sericitequartz «beards» adjacent to the ends of these grains are elongated along lineation. Based on the orientation of this lineation, the rocks during the formation of the cleavage S₁ were subjected to stretching in the northnorth-western direction. The carbonaceous shales of the Tuoguchan suite often contain the sedimentarydiagenetic carbon-quartz nodules and later pyrite crystals. Both are often surrounded by fibrous strain fringers (SF) composed of quartz and chlorite. The fibers in SF is rectilinear and parallel to S₁, which indicates the formation of SF during the coaxial deformation of rocks with stretching parallel to S₁. Based on the fiber directions in SF on pyrite crystals, the stretching during these SF formation was oriented mainly in the north-north-eastern direction, close to the axis of the Ulakhan-Sis antiform. The article also considers the crenulation cleavage S₂ (described in this area for the first time), locally superimposed on S₁. The S₂ cleavage zones correspond to the microfolds limbs into which the cleavage S₁ is bended. The cleavage S₂ has a north-eastern strike, close to the antiform axis, and a predominantly steep south-eastern fall. The cleavage S₁ formation may be associated with the first (thrust-fold) stage of the early collisional thrust phase of the Late Mesozoic deformations of the Verkhoyano-Kolyma orogenic region, and the crenulation cleavage S₂ – with the second (fold) stage of the same deformation phase.

Results of the experimental studies of the thermal regime in the upper horizons of the cryolithozone under natural conditions and during the development of the region are presented. The structure of radiation-thermal balance over the surface in different natural sub-zones is demonstrated. The effect of snow, vegetation and ground covers on the formation of thermal regime of the soils of annual heat turnover is evaluated quantitatively. The effect of technogenic impact on the thermal regime of soils is estimated on the basis of mathematical modeling. Results of the prediction of changes in the thermal state of soils caused by the development of the northern taiga, forest-tundra and southern tundra territories are described. The major tasks of geothermal monitoring related to the arrangement of observation stations and testing areas in the regions under development are proposed.

The content of organic and inorganic carbon was evaluated in the upper part of the active layer of the Holocene sediments, represented mainly by sandy loam formed at the Bestyakh and Tyungyulyun terraces in the Lena-Amga interfluve. A clear pattern of organic carbon decrease from south to north in relation to the structural features of terraced landscapes is observed. On average, this parameter is 7.70 % С_org at the southern margin of the Tyungyulyun pseudo-terrace, 1.64 % С_org in the central part of the Tyungyulyun surface (the Byokyo region) , while to the north, at the joint of the Tyungyulyun and Bestyuakh surfaces, the content of organic carbon decreases to the minimal value, which is 0.99 % С_org. Inorganic carbon exhibits a more complicated scattered distribution between the terraces. in the central part of the Tyungyulyun surface, its average content is 1.03 % С_inorg, with a sudden decrease at the Tyungyulyun pseudo-terrace to 0.19 % С_inorg and at the highland of the Ulu-Kyuel region to 0.03 % С_inorg. The effect of the post-pyrogene past at the Maya-2 and Bedzhelek sites is depicted in the depletion and loss of the noticeable content of organic carbon from the upper soil horizons in comparison with the Maya-1 region by 55 % and 80 %, respectively. At the same time, an increase in the content of carbon of plant origin up to the initial level is outlined during self-recovery for 19 years.

The data on the history of the morphological analysis of loose materials are presented. The existing procedures of sediment diagnostics are described, the major problems related to their application and correlation of the results are considered. The modern status of micromorphological analysis in the set of lithological-facial investigations is analyzed. The development of the method was promoted by the technological advancement in the 20th century. The application of electron microscopy has brought the method under consideration to a brand new level. The method was originally developed to recover the settings of transport and accumulation of Quaternary sediments outside the boundaries of the cryolithozone. However, since the 1970-s, investigation of grain surfaces started to be applied to study the features of cryogenesis manifestations in sedimentary deposits. At the modern stage, up-to-date methods to study particle surface with the help of computer tomography are under introduction. This broadens the area of the application of micromorphological analysis of loose sediments for various purposes. A set of diagnostic elements allocated as a result of the application of this method for the Kyzyl-Syr dune area in the basin of the Vilyuy river and for the section of the Abalakh surface in the middle reach of the Lena river is presented.

The storage conditions have a significant effect on the preservation of the properties and quality of mammoth tusk (MT) after extraction prior to artistic processing. One of the most significant factors in preserving the quality of the raw material is prevention of its biocontamination by environmental microorganisms. They use the organic components of the tusks as a source of nutrition and energy, leading to its early destruction. This paper describes the results of the primary screening of microorganisms-pathogens causing biocontamination of MT samples after long-term storage under various conditions. The sporeforming and mycelium-forming groups of microorganisms were identified. The connection of the detected microflora with the external environment (soil, atmospheric air, indoor air, refrigeration unit) was established. The results will serve as a basis for formulation development to prevent biological damage to mammoth tusk during long-term storage.

Ice-related phenomena made a significant contribution, more than 0.5 m, into the formation of the maximal water level on the Amga River in the cross section near Amga settlement during 41 high water episodes out of 76 (1938–2018). The average value of the ice jamming input into the maximal water level was 1.6 m, during the years with floods – 2.4 m, and the maximal value exceeded 5 m. With respect to the genesis, floods on the Amga River belong mainly to discharge-jamming type – fourteen cases, or to discharge type – five cases during the years 1938 to 2018. The scenarios of the development of discharge and ice-jamming floods differ from each other. Ice-jamming floods occur four days earlier on average and involve lower moisture content in the snow than that in the case of discharge floods. During the years with late expanded springs, floods occur very rarely. Synoptical parameters may be used to make assumptions concerning the type of forthcoming floods, but it is necessary to develop more accurate quantitative methods to predict the probability of the floods and their expected levels. These methods should take into account the non-stationary nature of the main synoptical factors leading to waterfloods. The rate of flood repetition during the time of observation remains unchanged, which points to inefficiency of the measures against jamming that were carried out in the river basin during the two recent decades.

The aim of the study is to conduct a research on reproductive development of Betula czerepanovii Orlova in the impact zone of the Severonikel plant (Murmansk region). The gross content of heavy metals (Ni, Cu, Pb, Cd) in the soil of test plots is determined by atomic absorption spectrophotometer. Inhibition of the birch trees reproduction is observed only on the technogenic wasteland (3 km from Severonikel) with very high concentrations of nickel (795 mg/kg) and copper (149 mg/kg) in the soil. Significant correlation coefficients between concentration of nickel in the soil and the number of male and female inflorescences of B. czerepanovii are obtained. The number of female catkins, formed under the conditions of chronic pollution by heavy metals, is larger than the number of male catkins. At all test sites, a transition of some birch trees (20–40 %) from monoeciousness to dioecia is demonstrated: a very large number of only male or female catkins is developing on them. Сenopopulations of B. czerepanovii are adapted to pollution in technogenic open woodland (8 km from Severonikel) and defoliating forest (20–30 km) with a decrease of Ni concentration in the soil to several MPC. It is shown that B. czerepanovii is a metal-resistant species. The hypothesis of the polyvariance of development of plants under the conditions of industrial pollution is formulated.

Results of the investigation into the effect of multiconversion biopreparation Embiota, obtained using five producing strains grown on the exhausted straw substrate of the oyster mushroom, on in vitro growth and development of micro-stalks of regenerant potato plants of «Rozara» are presented. The biopreparation was introduced in the concentrations of 2.5; 5; 10; 25; 50 and 100 mL/L into the growth medium containing the elements according to Murashige and Skoog formulation, with the full and half salt compositions. It is demonstrated that in the case of the availability of mineral nutrition, the biopreparation had no effect on the morphological parameters of vegetative organs within the whole range of studied concentrations. At the same time, in the version with 2.5 mL/L, an increase in the air-dry mass of above-ground organs by a factor of 1.3–1.4 was detected, while in the version with 100 mL/L this parameter exhibited a decrease by a factor of 1.2–1.3 in comparison with the reference. Under the conditions of insufficient nutrition, the growth-stimulating effect was registered in the versions with 5 and 10 mL/L. An increase in the parameters characterizing the number of shoots and leaves by a factor of 1.3–1.5 over the reference was detected. The concentration of 10 mL/L also has the best effect on the formation of the root system. Inhibiting action on the morphometric parameters of plants and their phytomass was detected after the introduction of the biopreparation in high concentrations 50 and/or 100 mL/L, which was especially clearly shown in the case when nutrition was insufficient. So, the results of the studies showed dose-dependent effect of «Embiota» biopreparation on the growth and development of plants. From the viewpoint of application for growth stimulation and for enhancement of productivity, the concentrations 2.5–10 mL/L may be used.

Within the framework of the prospective investigation, we studied and substantiated the application of the natural biological product Betukladin as additional preparation in the complex therapy for treatment of the following diseases: chronic viral hepatitis B with delta agent (CVH B+D), destructive pulmonary tuberculosis with extensive and multidrug resistance (XMDR-TB), and moreover, for prevention and rehabilitation of patients after severe COVID-19. Experimental group included 14, 23, 165 and 196 people, respectively; control group included 217 people. Betukladin is encapsulated ultrafine powder containing a complex of lichen β-oligosaccharides with pharmacons, obtained through mechanical and chemical activation of the Cladonia blastemas and butulin from birch bark. The product demonstrates antiviral, immunomodulating, anticoagulant, antibacterial hepatoprotective, antihypoxant, hypolipidemic, detoxicative activity. The complex of lichen bioactive substances and butulin have previously passed toxicological, preclinical and clinical trials (for a number of pathologies) in the form of nutraceutical products Yagel Detox and Betulin. The use of the biological product has enhanced the efficiency of the complex treatment of patients with CVH B+D. It demonstrated significant increase in the total protein level and albumin, a decrease in the cytolysis of hepatocytes, normalization of the levels of leucocytes, thrombocytes and hemoglobin, improvement of the general condition, quality of sleep and work capacity. The clinical trial of Betukladin in phthisiology revealed its high efficiency in treating XMDR-TB: intoxication symptoms were detected to decrease in 100 % of the patients; abacillation, cavity closure, clinical cure of tuberculosis were revealed in 87–78 % of the patients (control: 60 and 40 %, respectively). The liver values improved by 12–32 % (in control, these values worsened by 10-30%). COVID-19 prevention resulted in the disease rate of 3.0 among the people taking Betukladin, while the disease rate in the control group was 13.1 %. Patients taking the biological product at the stage of rehabilitation after COVID-19 with severe pneumonia showed rapid regression of residual effects of the disease (rapid fatigability, depression, and recovery of work capacity), while in the control group, recuperation lasted for one to three months and had severe forms.

Dwarf pine (Pinus pumila (Pall.) Rgl) is a coniferous evergreen representative of the Pinus genus, Pinaceae family. In the Republic of Sakha (Yakutia), Pinus pumila occupies substantial areas and is well known for its forage characteristics. In the traditional medicine of north-eastern Asia, a number of curative properties are assigned to this species, which allows us to relate P. pumila to the list of promising medicinal plants. Previous studies were focused on the content of terpenes, so that phenolic compounds in the needles of P. pumila were left without attention in spite of their high antioxidant activity. In the present paper, the results of qualitative and quantitative analysis for the concentrations of phenolic compounds in the needles of Pinus pumila growing in Yakutia are reported. The samples of plant material were collected in the Oymyakonsky district in 2018. For analysis, the raw material was extracted with 70 % ethanol with subsequent filtration of the extract. The quantitative content of flavonoids and phenolic compounds was determined using an SF-2000 spectrophotometer. The concentration of flavonoids, recalculated for the standard rutin sample, was 0.376±0.065 %. The total content of phenolic compounds determined using the Folin-Ciocalteu reagent was 32.01 % in the 70 % ethanol extract of the needles of P. pumila and 7.48 % in its aqueous extract.

The study focuses on the moss flora in one of the largest nature reserves in the Far East of Russia. The moss component of the hard-to-reach Seymchan cluster of the Magadansky State Nature Reserve is examined for the first time. Bryofloristic aspect of the territory has not been widely studied, which makes taxonomic revision of the moss flora of Russia complicated. The present studies were carried out during two field seasons (2019 and 2020) on the right bank of the Kolyma river (Reserve territory) and on the left bank of the river. During the studies moss species that are novel for the Magadan Region were detected. The sites with rare species were specified, and the state of their populations was identified. The general list includes 148 species, while 102 of them have been detected in the territory of the cluster. Thirty new species are reported in the territory of the reserve. The annotated list with the data on the habitat and occurrence rates of the species was compiled. The materials have been analyzed at the Laboratory of Botany, Institute of Biological Problems of the North FEB RAS. The species that were hardto-locate in taxonomy have been tested at the Botanical Institute RAS. The collected samples are stored in MAG, and doublets at LE. This article provides a discussion on the features of revealed flora: a detailed analysis of bryoflora is presented; the moss cover is characterized in the major types of vegetation, practical recommendations are given.

Results of the investigation on the effect of thermooxidative aging conditions on the destruction of polymer composite material (PCM) based on recordable parameters of acoustic emission (AE) are reported. The objects of investigation were the samples cut out of a fiberglass plate. The plate was made by vacuum infusion using the Derakane 411-350 binder and 9 layers of St-62004 glass fabric. Samples were aged by exposing in the muffle furnace for 96 hours at a temperature of 60, 100, 120 and 200 °C. Mechanical tests were carried out by three-point static bending. AE was recorded with the hardware and software complex deleloped at the Komsomolsk-na-Amure State University. Two-stage clusterization of the frequency components of the signal spectra of the detected AE was carried out using the Kohonen self-organizing map according to the procedure developed previously and tested by the authors. The types of damage of PCM structure are characterized over the centroids of the resulting clusters. The kinetics of destruction process is described on the basis of cluster accumulation during mechanical tests, depending on the conditions of thermooxidative aging. The negative effect of increased temperature on the degradation of the polymer matrix was determined, leading to a decrease in the ability of efficient distribution of internal strain in the matrix over the PCM volume due to distortion of the adhesion with reinforcing material.