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The structure and phase composition of samples of a Ti – 6Al – 4V alloy obtained using an EOSINT 280M laser printer are studied using scanning and transmission electron microscopy after cyclic three-point bending tests at room temperature. The features of the deformation process during bending of the samples are considered. It is shown that, in contrast to the cast alloy that fractures by a brittle mechanism, the Ti – 6Al – 4V alloy produced by laser 3D printing undergoes brittle-ductile fracture under the conditions of cyclic bending deformation, which is associated with formation of new pores in the deformed alloy. [ABSTRACT FROM AUTHOR]

Ecosystems of the fjell fields in the Khibiny Mountains (Kola Peninsula) are investigated, including vegetation, soils, soil algae, and invertebrate fauna. We use EUNIS habitat typification (2013) to differentiate habitats. The most common habitat types include (1) crustose–lichen (Rhizocarpon geographicum) rock on eluvium of base-rich, alkaline, and siliceous rocks (U5111); (2) lichen-, sedge-, and dwarf- and shrub–dominated turfs and cushions on gravelly and rocky slopes (U5112); (3) sedge-, moss-, and lichen–dominated on rubble and stony mountain plateaus and peaks (U5113); (4) biological soil crust on fine-earth and gravelly polygon edges (U5114); and (5) late snow bed moss vegetation (U5115). Soils of the fjell fields are represented by Leptosols. The content of soil organic C is very high (26–32%), despite the thin soil profile, which has no illuvial–eluvial differentiation by the content of SiO2 and R2O3. The total flora includes 176 species of plants and lichens. Soil alga flora is composed of 43 species, where green algae of Chlorophyceae prevails. Soil microarthropods are dominated by Collembola, Oribatida, and Mesostigmata, which are also typical for mountain tundra. The soil microbial activity and the diversity and abundance of soil algae and invertebrates depends on the habitat type and soil moisture, as well as on soil organic matter content and increases on wet substrates or under more complex vegetation. [ABSTRACT FROM AUTHOR]

A comprehensive study of the influence of hot rolling on structural-phase transformations and physical and mechanical properties of a metastable (α + β) alloy with a shape memory effect Cu–41 wt % Zn is carried out. Structural-phase transformations are investigated using optical and electron microscopy, X-ray phase analysis, and differential scanning calorimetry (when heated). It is discovered that intermediate bainitic transformations occur in the alloy along with the formation of martensitic phases. The peculiarities of the mechanical behavior of the alloy are established when testing samples using the uniaxial tensile method after hot rolling and subsequent heat treatments. It is established that hot rolling with a total reduction of 90% and subsequent heat treatment lead to an increase in the ductility of the alloy up to 48%. [ABSTRACT FROM AUTHOR]

A comprehensive study of structural-phase transformations and physical and mechanical properties of metastable Cu–39.5 wt % Zn α + β alloy with the shape memory effect subjected to thermomechanical treatments including cold rolling and annealing has been carried out. The features of the fine structure formed at the intermediate and bainitic phase transformations have been studied using optical and electron microscopy as well as X-ray phase analysis. The temperature intervals of bainitic 3R/9R and other phase transformations were established by differential scanning calorimetry upon heating up to 500°C. In the case of the hardened alloy, the temperature of the bainitic transformation was close to 170°C. In mechanical tests conducted using uniaxial tension, it has been demonstrated that cold deformation and post-deformation heat treatment under different modes can be employed to obtain the alloy in high-strength or ductile states. These states are characterized by an ultimate strength (σu) greater than 700 MPa and a relative elongation (δ) greater than 40%, respectively. [ABSTRACT FROM AUTHOR]

The martensitic transformations in Cu–38Zn and Cu–39.5Zn (wt %) alloys with the shape memory effect have been studied using a combination of transmission and scanning electron microscopy, optical metallography, and X-ray diffraction analysis. When examining specimen upon cooling to low temperatures in the transmission electron microscope column, the features of martensite morphology and fine structure, as well as of electron microdiffraction in the alloys, have been ascetained. The structural types of martensite phases (3R) and (2H) have been identified in Cu–38Zn alloys, as well as (9R) and (2H), in Cu–39.5Zn alloys. The proposed crystallographic models of martensitic rearrangement in the alloys are based on an analysis of X-ray and electron diffraction, including diffuse electron scattering, as well as on the packing defects of the internal substructure of martensite. [ABSTRACT FROM AUTHOR]

An analysis of the ecological characteristics of cyanobacteria of the Svalbard Archipelago was carried out. Two groups of habitats (aquatic and terrestrial ones) were identified. The degree of water saturation was the main factor determining the development of cyanobacteria. The variability of habitats can be represented as a gradient of moisture from typically aquatic to subaerophytic and dry terrestrial habitats. Based on the number of finds and species richness, the most favorable habitats for cyanobacteria in Svalbard were as follows: (1) rocky communities under conditions of sufficient moisture, (2) exposed soil surfaces on which biological soil crusts were formed, (3) well-warmed slow streams, and (4) specific waterlogged habitats, such as seepages. Using the example of the analysis of the ecological characteristics of species growing on the archipelago, the concept of eurybiont properties of cyanobacteria was shown to be inconsistent. The greatest plasticity was exhibited by Nostoc commune Vauch. ex Born. et Flah., Microcoleus autumnalis (Trev. ex Gom.) Strunecky et al.,Calothrix parietina Thur. ex Born. et Flah., Oscillatoria tenuis C. Ag. ex Gom., and Pseudanabaena frigida (Fritsch) Anagn. All species, including those mentioned above, had obvious ecological preferences. An analysis of the substrate specificity of cyanprokaryotes indicated that the greatest number of their species was found in soil, rocky substrates, and moss-like environments. [ABSTRACT FROM AUTHOR]

The radiation patterns of broadband antennas have been measured in a laboratory using linear frequency modulation (LFM) of the signal. The investigations have been carried out on the basis of the Imitation−Full-scale Hydroacoustic Complex unique scientific installation (UNU "INGAK") of the Department of Electrohydroacoustic and Medical Equipment at the Institute of Nanotechnologies, Electronics, and Instrumentation of Southern Federal University. A special feature of the experiment is that the antenna pattern data are recorded at once in the entire operating frequency band and the frequencies of interest are extracted by digital processing of the measured data. [ABSTRACT FROM AUTHOR]

This work presents the analysis of the spatial distribution of number concentration, size distribution, and chemical composition of aerosol particles measured for the first time over the seas of the Russian Arctic. Various types of vertical distribution of the number concentration were recorded, characteristic of both coastal marine and continental areas. Most of them turned out to be of the continental type. Attention is also drawn to the almost complete absence of coarse particles above 2–3 km over all seas. The chemical composition of the Arctic aerosol at altitudes of both 200 m and 5000 m contains ions that can be referred to as both marine and continental. The identifiable carbon- and salt-free elemental part of the aerosol over the Arctic is 3–4 times larger than that of ions. Over all seas and at both altitudes, the Arctic aerosols mainly contain elements of terrigenous origin – Al, Cu, Fe, and Si. Over almost all seas, except the Barents Sea, Si is dominant in the elemental composition of the aerosol, its contribution over the Chukchi Sea reaching 85%. The analysis of backward trajectories showed that in all cases considered, whether the aerosol was formed over the continent or sea, air trajectories passed both over sea and over land. In this case, the formed particles could be enriched with additional ions and elements along their pathway. This work completes a cycle of the papers, devoted to studying air composition, which was carried out over the seas of the Russian Arctic in September 2020. Our results can be used to model the atmospheric processes occurring in the Arctic under the conditions of changing climate. [ABSTRACT FROM AUTHOR]

Background: Fibromyalgia (FM) is a chronic pain disorder of unknown aetiopathogenesis, in which the role of activity of the hypothalamic–pituitary–adrenal (HPA) axis is not clearly established. Methods: This study analysed the modulatory effects of disease chronicity and severity on cortisol levels. Hair cortisol concentrations (HCC) and clinical evaluation data (pain severity, impact of FM on daily activities, depression, anxiety, fatigue and insomnia) were collected from 47 female patients with FM and 36 healthy women (HW). Results: The results showed that disease chronicity, with a negative effect, and symptom severity, with a positive effect, were independent predictors of HCC. Patients with a shorter disease duration had higher HCC than patients with a longer disease duration and healthy participants. Furthermore, patients with greater symptom severity had higher HCC than those patients with lower clinical severity and healthy participants. While disease chronicity in FM was associated with a decrease in HCC, clinical severity increased HCC. Conclusions: These results support the existence of a dysfunction in the regulation of the HPA axis in FM and its possible contribution to chronic pain development. Significance: This is the first study to assess hair cortisol concentrations in a specific sample of patients with fibromyalgia (FM). This method is especially useful for the assessment of long‐term regular cortisol excretion. Results showed a two‐component model for explaining cortisol levels: disease chronicity, with a negative effect, and symptom severity, with a positive effect. This suggests that severe pain/stress evokes higher cortisol levels at earlier stages of FM, while in the longer term a decrease in cortisol levels was observed. [ABSTRACT FROM AUTHOR]

Small areas of steppe-like vegetation (steppoids) occur on southern slopes among open larch woodlands in the lower reaches of the Kolyma River, northeastern Siberia. Depending on the soil parent material, they are divided into petrophytic (on the bedrock colluvium) and thermophytic (on silty loam of the Yedoma (Ice Complex) formation) steppoids. Xeromorphic deeply thawing soils with diverse humus-accumulative horizons, high content of roots, fine subangular blocky structure, and an increased content of water-stable microaggregates are formed in steppoids. These soils from differ from the soils of surrounding taiga landscape by the decreased actual and potential acidity; higher contents of exchangeable bases, soluble salts, carbonates, and organic nitrogen; smaller ratio between concentrations of oxalate- and dithionite-extractable iron. The soils of steppoids, especially thermophytic steppoids, are zooturbated. Dark mull-like forms of humus on the surface of mineral grains are present among the microaccumulations of organic matter in these soils. The features of cryoxerozemic pedogenesis are better manifested in petrophytic steppoids. The soils of thermophytic steppoids have similar features with steppe cryoarid ones, but differ from the latter in the absence of carbonate-accumulative and cryohumus horizons and in a relatively high acidity. Among the soils of petrophytic steppoids, gray-humus lithozems and gray-humus or mucky–dark-humus soils with carbonate incrustation can be distinguished. The soils of thermophytic steppoids can be classified as gray-humus or mucky–dark-humus surface-turbated (zooturbated) soils. [ABSTRACT FROM AUTHOR]

One of the possible sources of carbon dioxide emission into the atmosphere can be river ecosystems. The paper presents the results of measuring CO2 fluxes from the surface of several rivers and lakes in Tomsk Region. In the experimental period, average carbon dioxide fluxes were 143.7 ± 21.7 (August 13–14, 2023), 53.3 ± 21.2 (August 19), and 80.4 ± 59.9 mgC m−2 h−1 for the Ob River; 66.1 ± 17.3 mgC m−2 h−1 for the Ket River; 33.3 ± 17.3 mgC m−2 h−1 for the swamp Karasevoye Lake, 50.2 ± 23.0 mgC m−2 h−1 for the Suiga River, and 81.9 ± 11.5 mgC m−2 h−1 for the Iksa River. The flux magnitudes significantly depended not only on the object of the study, but also on hydrometeorological conditions. [ABSTRACT FROM AUTHOR]

New titanium(+4) and vanadium(+5) 8-oxyquinolinate complexes were synthesized. Their structures were determined by X-ray diffraction. The synthesized compounds catalyze the polymerization of ethylene in the presence of Al/Mg activators, {Et2AlCl/Bu2Mg} and {Et3Al2Cl3/Bu2Mg} (up to 3400 kg of PE (mol of [M] h atm)−1), to form ultrahigh-molecular-weight polyethylene with a molecular weight up to 5.3•106 Da. The synthesized compounds are shown to be efficient precatalysts for the synthesis of ethylene-octene copolymers. A high insertion of 1-octene into the copolymer composition, up to 9.5%, was observed for vanadium [bis(7-tert-butyl-2,5-dimethyl-8-oxyquinolinato)]dipropoxide. [ABSTRACT FROM AUTHOR]

The probability of martensitic transformation in stable 316L austenitic steel obtained using a 3D laser printer is investigated. Compressive deformation of the studied samples was carried out at room temperature at a high rate (2 × 10–2 sec–1). The features of the martensitic transition and the conditions for formation of an intermediate phase of epsilon-martensite are considered. [ABSTRACT FROM AUTHOR]

The phase formation and macro/microstructure of a porous skeleton based on Ti3SiC2 MAX phase prepared by self-propagating high-temperature synthesis of green mixtures consisting of Ti powders differing in particle size, different carbon powder forms, and Si powder in a sand backfill in air. Comparative data on porosity, compressive strength, and quantitative phase composition of synthesized samples were presented. It was established that the fractional composition (particle size) of Ti and C powders, as well as the form of C (graphite, carbon black) influence markedly the macrostructure of porous SHS skeletons. The porous skeleton obtained using coarse Ti and medium colloidal graphite powders was found to have high content of Ti3SiC2 MAX phase (66%) and to possess high density and compressive strength (2.41 g/cm3 and 104 MPa, respectively). [ABSTRACT FROM AUTHOR]

Based on the results of a comprehensive experiment conducted in September 2020, the spatial distribution of the following trace gases over the seas of the Russian Arctic are analyzed: carbon monoxide (CO), ozone (O3), nitrogen oxide and dioxide (NO and NO2), and sulfur dioxide (SO2). It is shown that the gas concentrations in the surface air layer over the seas (at an altitude of 200 m) vary in the range 18–36 ppb for O3, 60–130 ppb for CO, 0.005–0.12 ppb for NO, 0.10–1.00 ppb for NO2, and 0.06–0.80 ppb for SO2. The distribution of the gases over the water area is heterogeneous over most seas, which most likely reflects differences in their uptake by the ocean and peculiarities of transport from the continent. [ABSTRACT FROM AUTHOR]

A theoretical method is proposed for determining the duration of abrasive finishing of cylindrical external surfaces. The method takes account of the initial geometric deviation, the productivity, and the kinematic parameters. By this means, the machining time may be established, taking account of the operations involved, and the best finishing conditions for precision surfaces may be established, so as to ensure the required surface roughness (Ra no greater than 0.2 µm) and geometric precision (deviation from cylindrical form no more than 0.002 mm). [ABSTRACT FROM AUTHOR]

The current state of the global and Russian machine tool industry is described. The kinematic differences between Russian and imported machines for the polishing and finishing of high-precision surfaces are itemized. A prototype Russian polishing system is discussed, noting its technological features, ergonomic design, and operational safety. [ABSTRACT FROM AUTHOR]

The experiment on the placement of side acoustic steel screens at different heights from the radiating surface is described. The radiation patterns (RPs) have been recorded. The width of the main lobe of the RP in a vertical plane at a level of 0.707 is analyzed as a function of the heights at which the side acoustic shields are located. [ABSTRACT FROM AUTHOR]

We consider the distribution of tropospheric ozone on the territory of Russia in 2022 using data from 33 stations located in different physical and geographical zones, as well as its vertical distribution from results of aircraft sensing. It was shown that measurements at all measurement sites exceeded the maximum permissible daily average concentrations, determined by the national hygienic standard. In some regions, the excess over the maximum permissible concentrations of the working zone and over the maximum one-time hourly average concentrations is recorded, so that the population should be broadly warned about the monitoring results and measures should be taken to reduce the level of ozone concentration in the surface air layer. [ABSTRACT FROM AUTHOR]

A series of novel complexes of titanium(IV) with OSSO-type ligands were synthesized. In the presence of Al/Mg activators such as {Et2AlCl+Bu2Mg} and {Et3Al2Cl3+Bu2Mg}, all the synthezed compounds catalyzed the polymerization of ethylene (with activity up to 2554 kgPE molM–1 h–1 atm–1). The otained ultrahigh-molecular-weight polyethylene (UHMWPE) samples had a molecular weight up to 7.6×106 Da and exhibited high melting points (up to 143°C) and high crystallinity (up to 84%). It was demonstrated that these polymers can be processed by a solvent-free method into high-strength/high-modulus oriented films (with breaking strength up to 2.2 hPa and elastic modulus up to 127.7 hPa). The synthesized compounds further manifested themselves as efficient pre-catalysts (as indicated by their catalytic activity up to 408 kgcopolymer molM–1 h–1 atm–1) for the preparation of ethylene–propylene copolymers with high propylene incorporation (up to 37%). [ABSTRACT FROM AUTHOR]

We analyze the spatial distribution of carbon dioxide over the seas of the Russian Arctic based on the results of the comprehensive experiment conducted in September 2020. It turned out that during the experiment, the concentration of CO2 increased from west to east. The minimum of 396 ppm was over the Barents Sea, and the maximum of 4106 ppm was over the Chukchi Sea. The difference between the concentrations at an altitude of 200 m and in the free troposphere attained 156 ppm over the Barents Sea and decreased to 56 ppm over the Laptev Sea. Over the eastern seas, the difference became generally positive, which was associated with the air transfer from Alaska. Above the waters of most seas, the distribution of carbon dioxide was horizontally heterogeneous, which showed the regional features of its assimilation by the ocean and transfer from the continent. [ABSTRACT FROM AUTHOR]

In the Arctic, global warming is 2–3 times faster than over other regions of the globe. As a result, noticeable changes are already being recorded in all areas of the environment. However, there is very little data on such changes in the Russian Arctic. Therefore, to fill the gap in the data on the vertical distribution of the gas and aerosol composition of air in this region, an experiment was carried out on the Tu-134 Optik flying laboratory in September 2020 to sound the atmosphere and water surface over the water areas of all seas in the Russian Arctic. This paper analyzes the spatial distribution of methane. It is shown that during the experiment its concentration was the highest over the Kara Sea (2090 ppb) and the lowest over the Chukchi Sea (2005 ppb). The East Siberian and Bering Seas were slightly different from the Chukchi Sea in terms of the methane concentration. Average values of CH4 are characteristic of the Barents (2030 ppb) and the Laptev Seas (2040 ppb). The difference between the concentrations at an altitude of 200 meters and in the free troposphere attained 150 ppb over the Kara Sea, decreased to 91 and 94 ppb over the Barents and Laptev Seas, and further decreased over the East Siberian, Chukchi, and Bering Seas to 66, 63, and 74 ppb, respectively. Horizontal heterogeneity in the distribution of methane over the Arctic seas is the greatest over the Laptev Sea, where it attained 73 ppb. It is two times higher than over the Barents and Kara Seas, and 5–7 times higher than over the East Siberian and Bering Seas. [ABSTRACT FROM AUTHOR]

A series of novel complexes of titanium(IV) with OSSO-type ligands were synthesized. In the presence of Al/Mg activators such as {Et2AlCl+Bu2Mg} and {Et3Al2Cl3+Bu2Mg}, all the synthezed compounds catalyzed the polymerization of ethylene (with activity up to 2554 kgPE molM–1 h–1 atm–1). The otained ultrahigh-molecular-weight polyethylene (UHMWPE) samples had a molecular weight up to 7.6×106 Da and exhibited high melting points (up to 143°C) and high crystallinity (up to 84%). It was demonstrated that these polymers can be processed by a solvent-free method into high-strength/high-modulus oriented films (with breaking strength up to 2.2 hPa and elastic modulus up to 127.7 hPa). The synthesized compounds further manifested themselves as efficient pre-catalysts (as indicated by their catalytic activity up to 408 kgcopolymer molM–1 h–1 atm–1) for the preparation of ethylene–propylene copolymers with high propylene incorporation (up to 37%). [ABSTRACT FROM AUTHOR]

The ERA 5 reanalysis data and the daily average surface ozone concentrations (O3) measured at the TOR station from 1993 to 2020 are used to study the circulation pattern favoring the formation of extremely high ozone concentrations (95th percentile, henceforth О395). All months are characterized by an identical circulation mode accompanied by an increase in the surface air temperature in the area encompassing the ozone concentration measuring station. In addition to the increase in the air temperature, О395 events are characterized by strengthening of the southwesterly component of the wind velocity field. It is also found that these circulation features are associated with the development of meridional properties, probably due to the propagation of waves in the upper troposphere in midlatitudes. The identified circulation mode simultaneously favors the transboundary transport of ozone and its precursors from the southern regions, the enhancement of photochemical O3 formation, and the occurrence of wildfires. [ABSTRACT FROM AUTHOR]

The article discusses heterogeneity of autism spectrum disorder (ASD) in terms of the severity of autistic manifestations, cognitive, and speech abilities in children with different levels of functioning. The results of a study of speech understanding at the level of phonology, vocabulary, morphosyntax, and discourse in primary schoolchildren with ASD are presented. The study has revealed correlations between the severity of autistic manifestations of a socio-communicative nature and nonverbal IQ with various aspects of speech understanding. Comparison of the correlations in the subgroups of children with different levels of functioning detected the differences between the subgroups, indicating different mechanisms of disorders. The differences of EEG spectral characteristics in children with ASD compared with the age norm and characteristics in the studied subgroups are shown. The differences in EEG spectral characteristics have been found between subgroups with ASD with different levels of functioning: the subgroup with less pronounced disorders is characterized by a higher index of β2-activity, while the subgroup with more pronounced disorders, by a higher index of slow-wave activity. [ABSTRACT FROM AUTHOR]

This research presents the application and comparison of the most popular machine learning algorithms (multilayer perceptron, ensemble of networks, convolutional neural network) to predict the shape of dynamic EPR signals of pH-sensitive nitroxide radicals (NR) with varying degrees of rotational correlation from EPR spectra obtained during the analysis of solid-phase systems. A training sample example consisting of theoretically modelled EPR spectra of pH-sensitive nitroxide radicals was prepared for the network learning. The result of applying and comparing machine learning algorithms with results obtained from simulations by the specialized software ODFR4 demonstrated that the multilayer perceptron and ensemble of networks have good accuracy in prediction signal shapes, however, within rather narrow scope of applicability. The convolutional neural network showed the worst results in predicting signal shapes. The results of this work can be useful for the development of software design to quickly estimate the parameters of analyzed systems by processing the EPR spectra of pH-sensitive nitroxide radicals. [ABSTRACT FROM AUTHOR]

The dynamics of greenhouse gas fluxes, measured from 2017 to 2021 at the Fonovaya Observatory of V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, is studied. It is shown that the annual average fluxes of CO2 at the Observatory varied from −283 (sink) to +31 mg m−2 h−1 (emission). A minimal emission of 1351 mg m−2 h−1 was recorded in 2019, and a maximum of 1789 mg m−2 h−1, in 2021. The lowest sink was observed in 2017 (2099 mg m−2 h−1); the largest, equal to 2304 mg m−2 h−1, was in 2018. The annual average methane fluxes ranged from −0.032 in 2018 to −0.047 mg m−2 h−1 in 2020. The daily maximal methane emission was recorded in 2018 and was equal to 0.915 mg m−2 h−1, and the daily minimal emission, in 2021 (0.095 mg m−2 h−1). The maximal sink varied from year to year in a narrower range from −0.241 to −0.361 mg m−2 h−1. The soil of the measurement area turned out to be a strong source of SO2 and CH4 and a weak source of N2O. The annual average fluxes of NO2 were in the 0.00–0.011 mg m−2 h−1 range. The interannual emission maxima weakly changed from 0.237 to 0.301 mg m−2 h−1, and sink maxima, from −0.206 to −0.245 mg m−2 h−1. [ABSTRACT FROM AUTHOR]

The processes of biodeterioration of the unique Tomskaya Pisanitsa monument of rock art in Western Siberia have been studied by a complex of biological and mineralogical methods. The species composition of the lithobiotic community (bacteria, fungi, and lichens) is identified using a complex of cultural, morphological, and molecular genetic methods. It is shown that the destruction of the monument is a result of interrelated physical, chemical, and biological processes, accompanied by a change in the properties of the rock and its biological colonization. The structure of microbial communities depends on the local environment and successional processes. The development of biofilms with the dominance of cyanobacteria is observed on the rock zones of increased moisture and the formation of carbonate crusts. The problems of adaptation of the lithobiotic microorganisms to existence at the Tomskaya Pisanitsa rock art monument, as well as their role in the processes of oxalate and carbonate biomineralization, are discussed. The results point to the danger of deterioration of Tomskaya Pisanitsa monument and indicate the need to find new effective ways to protect it, taking into account the accumulated scientific data. [ABSTRACT FROM AUTHOR]

Nonmetallic inclusions (oxides, silicates) in specimens of austenitic steel AISI 316L obtained with the help of a EOSINT M280 (EOS GmbH) laser 3D printer are investigated. The structural type, the chemical composition and the morphology of the inclusions are studied by scanning and transmission electron microscopy. The causes of the appearance of nonmetallic inclusions and their effect on the mechanical properties of the 3D articles are analyzed. [ABSTRACT FROM AUTHOR]

Optical spectroscopy and microscopy techniques are widely used for basic studies of living systems. However, their application in clinical practice has two fundamental limitations. First, the depth of probing biological tissues with light is small and varies from tenths to several of millimeters. Secondly, it is difficult to use exogenous labels, which increase the sensitivity and specificity of pathological tissue detection, in vivo measurements on patients. This raises the question of the place of biomedical photonics among other physical diagnostic methods used in clinical practice. This article presents an review of optical methods and relatively new certified commercially available medical devices that use photonics to solve intraoperative diagnostic problems, i.e., the discrimination between pathological and healthy tissue sites in vivo and ex vivo by an endogenous optical response. This work discusses a wide range of medical fields in which researchers and engineers have been able to achieve high rates of sensitivity and specificity in solving the problem of classifying such tissues. The advantages and disadvantages of optical imaging and diagnostic methods, which determine their place in clinical practice, are discussed by the example of intraoperative diagnostics. [ABSTRACT FROM AUTHOR]

Ozone is one of the most toxic admixtures in the troposphere. Therefore, it is among the main pollutants and its concentration is monitored. This work represents an overview of continuous measurements of the ozone content in the troposphere on the territory of Russia throughout 2021 carried out on an initiative of scientific and educational institutions at 17 stations in different Russian regions. The monitoring results showed that the daily average ozone concentration exceeded the MPCd.a level during a major part of the year at all observation sites, and by a factor of two or even three at a number of stations. At six stations, concentrations in excess of the maximum permissible one-time concentration MPCm.o were recorded. This requires a more comprehensive analysis of the composition and concentration of ozone precurcors and the development of measures to reduce their emission into the atmosphere. [ABSTRACT FROM AUTHOR]

The study of microbial complexes in organo-accumulative horizons of Antarctic soils (Cryosols, Leptosols) at the Larsemann Hills and Schirmacher oases and on King George Island has been carried out by the fouling glass method. This method allows one to study the taxonomic composition of microorganisms, features of their morphology, inter-organism interactions, and spatial organization of the complex of microorganisms, as well as to simulate the processes of colonization of mineral surfaces. The investigated microbial complexes can be subdivided into four groups with respect to dominant microorganisms: (1) diverse microbial complexes of King George Island with a considerable portion of diatoms among algae and with a predominance of mycelium in the fungal biomass; (2) complexes of lichen–moss, moss, and algal–moss associations in lake basins with a greater proportion of eukaryotic and coccoid cyanobacteria and with mycelium and sporous forms of micromycetes; (3) complexes of moss and algal–moss associations in the bottoms of wet valleys with a higher proportion of filamentous cyanobacteria and with the absence of fungi, or their presence in the form of short chains of chlamydospores; and (4) hypolithic microbial complexes of rock baths in dry rocky habitats, where the fouling of glasses did not take place. The microbial complexes in different glass samples taken in February–March in different years proved to be at different stages of development. Microscopic mycelium of fungi was not abundant in all algae and moss associations; in some, it was practically absent. Among algae, not cyanobacteria, but eukaryotic algae dominated in a number of habitats: diatoms, green algae, and streptophytes. The totality of the complex features indicated the extremity of the habitat: one morphotype of melanized fungal mycelium dominated in a particular sample; there was no diversity of spore forms, which indirectly indicates a low taxonomic diversity of fungi; multiple chlamydospore formation and microcycles of development were common. Among cyanobacteria, brown and reddish coloration was often found, and the formation of biofilms on glasses was limited to microcolonies, while algal biofilms abundantly covered the soil of the studied horizons. Apparently, extended biofilms were formed over time exceeding the exposure time of the glasses. Hypolithic communities did not colonize new habitats (glasses) for several years of exposure, unlike the bottoms of hydromorphic valleys and lake basins in oases (glasses overgrown in a year) and King George Island (glasses overgrown in 10 days). [ABSTRACT FROM AUTHOR]

The magnetic properties and the structure of 316L steel samples manufactured by the additive technology with employment the method of laser melting (laser synthesis (LS)) from a metallic powder have been studied. The change in the magnetic properties of LS-samples after high-speed deformation has been found. Lamellas of α' martensite were found in deformed samples. The dependence of the magnetic properties of the 316L steel samples manufactured by 3D printing on the strain rate is discussed. [ABSTRACT FROM AUTHOR]

The work is devoted to experimental investigation of the laser shock peening (LSP) effect on fatigue crack propagation and heat dissipation at the crack tip in specimens made of titanium alloy Grade 2 with a stress concentrator. It is shown that the LSP can lead both to positive and negative effect on fatigue lifetime. The effective processing scheme, which includes stress concentrator zone, was proposed. This type of treatment forms an optimal residual stress field, which slows down the crack initiation and propagation processes. The effective LSP processing scheme reduces the value of effective stress intensity factor and, as a consequence, effects on intensity of plastic deformation at the crack tip. This effect can be visualized by measurement of heat flux from the crack tip area. Both heat flux from the crack tip and duration of crack initiation are less in the LSP processed specimens. Microstructural investigations of LSP treated material near fatigue crack path have shown that structural defects (twins) that appear on the surface of the material as a result of LSP do not have a significant effect on the fatigue crack propagation, and the configuration of the residual stresses field created by LSP plays a decisive role. [ABSTRACT FROM AUTHOR]

It is proposed to consider the transition to postcapitalism not as the struggle of the oppressed for a more just and equal society without class antagonisms but as a process of gradual displacement of consumer individualism by expressive individualism. Within the framework of this perspective, postcapitalism is not a fundamentally new socioeconomic system built on the ruins of capitalism but a set of social relations developing with the gradual deactualization of materialistic values for a significant part of the population (material wealth, money, etc.) and the growing importance of postmaterialistic values (self-realization, the search for the true self, etc.). In this sense, many phenomena associated with modern identity politics can be attributed to postcapitalism. Nevertheless, this article criticizes the perception of identity politics as a set of strategies and ways of fighting for equality and justice, presented as an approximation to the ideals of socialism or communism (the so-called overcoming of "systemic oppression"). Today, the struggle for diverse identities testifies to the triumph of individualism, as well as a new round of the "war of all against all" and the destruction of the common lifeworld. [ABSTRACT FROM AUTHOR]

This paper describes properties of soils and litter formed in pine forests of Moscow oblast in areas used by gray herons as nesting grounds. It is established that the total trophicity of ecosystems sharply increases in areas with a high density of heron nesting sites compared to control sites, which is manifested in the widespread occurrence of species with strict requirements as regards the soil nutritive regime. The elevated content of water-soluble phosphorus forms, nitrates, sulfates, potassium, magnesium, and calcium in soils of heronries confirms this. By contrast, the concentrations of main components in control soils are typical for the zone of coniferous–deciduous forests. Taking the low mobility of phosphorus and its probable fixation in the composition of immobile complexes, it has been suggested that elevated concentrations of this element in areas where sod–podzolic soils are widespread and the role of anthropogenesis is excluded, which may indicate past effects of ornithogenic ecosystems. [ABSTRACT FROM AUTHOR]

The article presents the results of studying the spores and pollen preservation in soils of the permafrost zone in Yakutia (Kolyma Lowland, Bykovsky Peninsula, Yakutsk and its neighborhood). Data on the qualitative and quantitative composition of palynomorphs and on the patterns of their damage are discussed, and the mechanism of their cryogenic destruction is analyzed. Palynological residues with destruction of the chemical-biotic type (thinning of the walls, the formation of cavities as a result of the chemical action of microbes on them) are present singly or absent, which is probably due to the specificity of permafrost with a predominance of low temperatures throughout the year and a generally suppressed microbiological activity. Palynomorph damages of the physical type (ruptures and cracks) usually predominate. In samples from mineral horizons of loamy soils, the content of damaged palynological remains is 5–10%; in mineral horizons of sandy soil, it reaches 20%. In sandy soil, the content of unfrozen water films performing a cryoprotective role is low, and the palynomorphs are more susceptible to destruction by growing ice crystals during freezing. The large-size Gymnospermae pollen of Pinus and Larix is most susceptible to destruction. Damages are usually present on the dominant pollen of Poaceae and Betula sect. Nanae, as well as of Cyperaceae and Ericaceae. Few damage cases are characteristic of pollen grains of minor taxa: Salix, Duschekia, Asteraceae, Onagraceae, Ranunculaceae, Caryophyllaceae and of spores of Sphagnum and Bryales. There are no damages on pollen of herbs Valeriana, Polemonium, Artemisia, Chenopodiaceae, and Polygonaceae and on spores of Lycopodium, Diphasiastrum, Selaginella, and Polypodiaceae. The results can be used in the reconstruction of paleogeographic conditions for buried soils, as well as in the study of cryopreservation of biological objects in permafrost areas. [ABSTRACT FROM AUTHOR]

Abstract—The effect of the initial structures of titanium alloys containing 10 wt % aluminum and additionally alloyed with molybdenum, niobium, zirconium, and/or tin, which are formed by quenching from various phase regions, on the structure formation in the course of prolonged isothermal annealing at 650°С is studied. It is shown that, in alloys quenched from temperatures corresponding to the β region to form the α' martensite, the decomposition of the martensite and formation of the α-, α2-, and β-phases mixture within initial martensite plates occur. In this case, the formation of the α2 phase is realized via the nucleation and growth mechanism. In the alloys quenched from temperatures corresponding to the two-phase region, the spinodal decomposition occurs within the primary α-phase crystallites, and the α + α2 structure characterized by a great amount of antiphase boundaries forms. [ABSTRACT FROM AUTHOR]

The correlation between the radon influx into the atmosphere and the formation of ions has been studied from the data of observations at the Fonovaya Observatory of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences. This correlation is shown to be stable in the period from October to January. In the other months, the correlation is disturbed. However, if the events of nucleation and lightning discharges are removed from the data set, then the correlation is kept throughout the year. [ABSTRACT FROM AUTHOR]

The effects of additional alloying of titanium alloys containing 10 wt % aluminum with molybdenum, niobium, zirconium, and tin on the structure formation of upon quenching from the temperatures corresponding to the single-phase (β) and two-phase (α + β) regions, and on the crystal lattice parameters of the phases that are present in the quenched state are studied. It is shown that α'-martensite with a packet morphology is formed after quenching from the β-region. Alloying with zirconium increases the dispersity of the structure. In alloys quenched from the two-phase region, an α + α'-structure with a small amount of the α2‑phase is formed. The effect of alloying on the lattice parameters of the α- and α'-phases is analyzed. [ABSTRACT FROM AUTHOR]

A combined experiment aimed at the study of the air composition over all the seas in the Russian Arctic was carried out in September 2020 with the Optik Tu-134 flying laboratory. The experiment included sampling the of atmospheric aerosol in the air layer from 200 to 9000 m above sea level and determining the concentration of saturated hydrocarbons (n-alkanes) in aerosol particles. Saturated hydrocarbon compounds in the range С9Н20–С27Н56 were found in the air of this sector of the Arctic. The main mass of this class of organic compounds is concentrated in the narrower range С10Н22–С20Н42. The concentration of n-alkanes in aerosol over all the seas was low (ranging within 9.3–12.6 ng/m3). The only exception was the Chukchi Sea, over which the concentration attained 37.7 ng/m3. [ABSTRACT FROM AUTHOR]

Airborne sensing data are used to study the change in the air composition upon the transition from the troposphere to the stratosphere. The distribution of seven gases and the size spectrum and chemical composition of aerosol particles are analyzed. It is shown that when crossing the tropopause, the concentrations of H2О, CO, and CH4 sharply decrease, while the concentrations of О3 and NO2 and the aerosol particle number density, to the contrary, increase. Above the tropopause, Si predominates in the elemental composition and prevails in the ionic composition. In the troposphere, terrigenous elements Al, Cu, and Fe predominate, while in the ionic composition the prevailing set of several ions varies from one region to another. Noticeable differences in the size spectrum of particles are revealed as well. [ABSTRACT FROM AUTHOR]

Research on additives is important for many oil companies today. The rapidly growing market for lubricants has led to efforts to improve such materials through the development of new compositions. In the past decade, a strategic goal of the Russian oil refining industry has been to develop domestically-produced additives, compositions, and additive packages. In this article, trends are discussed on the development of promising products derived from a compound used in the synthesis of multifunctional additives. [ABSTRACT FROM AUTHOR]

2-Azidobenzoic acid has undergone rearrangement into 2-[(2-carboxyphenyl)amino]-6-formylnicotinic acid under irradiation in aqueous-organic media in the presence of acetates of alkali or alkaline earth metals. The structure of the resulting compound has been elucidated by methods of mass and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Arctic ecosystems contain a variety of habitats that are colonized by cyanobacteria. They are of fundamental ecological importance; they contribute to both carbon and nitrogen fixation as well as frequently acting as ecosystem engineers. The exploration of cyanobacteria in the Svalbard Archipelago began in the nineteenth century. A previously published list of cyanobacteria from the Svalbard Archipelago (Skulberg in: Elvebakk and Prestrud (eds) Terrestrial and limnic algae and cyanobacteria, Norsk Polarinstitutt, Skrifer, Oslo 1996) included 89 cyanobacterial species. Since then, several articles have been written and knowledge about the diversity of cyanobacteria has increased. This study summarizes the results of the inventory of Cyanobacterial species in the Svalbard Archipelago. The cyanobacterial flora of Svalbard was analyzed based on our data and literature records. Cyanobacterial samples were studied under a light microscope. Species were identified based on morphological characteristics only. As a result of this analysis, we compiled an annotated list of the cyanobacteria of Svalbard. A total of 292 species of cyanobacteria were recorded in the archipelago. 84 of these species are reported here for the first time. This makes Svalbard's flora the richest in cyanobacteria of any area in the Eurasian Arctic. Information on the distribution, description of habitats, and substrate preferences of the cyanobacteria was included for all taxa. The composition of the Cyanobacterial flora of Svalbard was compared with the flora of other Arctic and sub-Arctic regions, revealing that the flora of Svalbard exhibited typical Arctic features. For instance, the proportions of the main Cyanobacterial orders and families are the same in Svalbard and the rest of the Eurasian Arctic. The Cyanobacterial composition in the Arctic and sub-Arctic areas conforms to the general pattern of declining species diversity with increasing latitude. [ABSTRACT FROM AUTHOR]

The anomalous vertical distribution of organic aerosol recorded on September 14, 2018, is analyzed on the basis of aircraft sounding data. It is anomalous in that, in contrast to the long-term average profile, the maximal concentration in the boundary layer during this flight was more than an order of magnitude higher than the previously measured concentrations. The contribution of aerosols of different origins to the total concentration in different tropospheric layers is estimated. The analysis of possible sources of aerosol precursors revealed quite a wide sector, on the territory of which there are boreal forests, which are sources of biogenic compounds, and objects of industrial infrastructure, which are sources of anthropogenic emissions. [ABSTRACT FROM AUTHOR]