bluuebunny/crossref_metadata_2025 huggingface dataset:
MICRO-ALLOYED MOLYBDENUM ALLOYS FOR THE CREATION OF SURFACE-IONIZATION EMITTERS
Authors: Dement'ev V. A , Lachenkov S. A , Kas'yanov V. S , Kirillova V. M , Sdobyrev V. V
Published: April 2024

Molybdenum-based alloys with different surface-ionization properties for thermal emitters have been developed. The morphology of the oxidized alloys surface is investigated, a qualitative analysis of the formed oxides is carried out. The possibility of using these alloys to create multisensory amine sensors is shown.
CALCULATED ESTIMATION OF NITROGEN SOLUBILITY AND PHASE COMPOSITION OF STEEL BASED ON Fe-13% Cr WITH ITS ADDITIONAL ALLOYING (Mn, Mo, V, Nb)
Authors: Kostina M. V , Rigina L. G , Kostina V. S , Kudryashov A. E , Fedortsov R. S
Published: April 2024

Estimates of the nitrogen solubility in model steels of various compositions based on Fe-13%Cr with additional alloying (a small amount from hundredths of a percent to 1.5%) with elements (Mn, Mo, V, Nb) that increase the solubility of nitrogen in iron-based solid solutions are calculated. 60 variants of compositions were studied. Based on previously obtained own experimental data for nitrogen-containing steels with a content of 16%Cr-5%Ni-Nb for martensitic steel, a preliminary assessment of the composition stability coefficient of nitrogen used in the calculations of its (nitrogen) solubility was carried out. The resulting value of the composition stability coefficient is lower than for austenitic steels. For steels of all composition variants with calculated nitrogen content and different content of additional alloying elements (Mn, Mo, V, Nb), the phase composition was estimated using a modified Scheffler—Delong diagram and a nonequilibrium Potak—Sagalevich diagram for steel, which processed on solid solution. It is shown, among other things, that all compositions of Fe-13%Cr-Mn, Mo, V, Nb with a low carbon content (0.03—0.05%) with the maximum calculated solubility of nitrogen in the metal are in the martensitic-ferritic region. By calculation, the temperature of the martensitic transformation beginning was obtained using the empirical Finkler—Schirra formula and a correlation was established between the temperature of the martensitic transformation beginning and the Niequivalent/Crequivalent ratio (chromium and nickel equivalents calculated using formulas for the modified Scheffler—Delong diagram).
THE EFFECT OF GRAVITY FORCE ON THE MOVEMENT OF TITANIUM POWDER PARTICLES IN THE PLASMA FLOW
Authors: Okulov R. A , Krashaninin V. A , Gel'chinskiy B. R , Rempel' A. A
Published: April 2024

An attempt is presented to determine the influence of the spray direction on the particles movement in a plasma flow in order to assess the influence of gravity. Three spray directions are selected: down, up and horizontal. Titanium powder PTM-1 TU 14-22-57-92 was considered. For each of the spraying directions under consideration, the movement of titanium powder particles of different dispersion in the plasma flow was calculated using the finite element method with using the SolidWorks software package. Particles with sizes of 1, 50 and 90 microns were selected as the sprayed powder material. The change in the temperature of powder particles when moving in a plasma flow depending on the direction of spraying has been studied. A comparative analysis was carried out for the spraying directions under consideration, based on the results of which the advantages and disadvantages were described and recommendations were given for conducting the processes of obtaining powder and applying coatings. The presented data can be useful when choosing the position of the substrate for applying functional coatings. The influence of gravity on the separation of the resulting powders and on the temperature distribution of the plasma flow in the studied area is demonstrated. To verify the calculation results, a full-scale experiment was carried out in a plasma installation assembled at the IMET Ural Branch of the Russian Academy of Sciences, which is used for producing powder and applying coatings, taking into account its design features. The results have practical benefits for developers and consumers of technological equipment.
TITANOMAGNETITE CONCENTRATE PROCESSING BY SORPTION CONVERSION
Authors: Lokshin E. P. , Tareeva O. A.
Published: April 2024

A hydrometallurgical technology for processing titanomagnetite concentrate has been proposed and justified. It includes the decomposition of the concentrate in low-concentration sulfur-acidic solution in the presence of sulfonic cation exchanger in H+ form with the transfer of the main part of the metals of the titanomagnetite concentrate into the sorbent and obtaining a residue enriched with ilmenite, desorption of metals from the saturated sulfonic cation exchanger with a 5 M sodium chloride solution, fractional hydrolytic precipitation and separation of titanium hydroxide, vanadium-enriched iron hydroxide, pure hydroxide iron and mixtures of iron and manganese hydroxides, regeneration of sulfonic cation exchange resin. The optimal parameters for carrying out individual processes have been determined. The technology practically does not consume sulfuric acid and does not generate liquid waste.
INVESTIGATION OF THE PHOSPHATE IONS ADSORPTION FROM ALUMINATE SOLUTIONS BY Fe-AС NANOCOMPOSITE
Authors: Geydarov A. A , Babaeva P. G , Gulieva A. A , Alyshanly G. I , Dzhabbarova Z. A
Published: April 2024

The adsorption of phosphate ions from model solutions by a nanocomposite based on trivalent iron oxide-hydroxide and activated carbon (Fe-AС) was studied. Factors studied affecting the adsorption of phosphate ions: solution pH; adsorbent amount; initial concentration of phosphate ions in solution; contact duration. The efficiency of phosphate ion extraction increased with increasing adsorbent dosage (from 2.5 to 10 g/l) with an initial concentration of phosphate ions of 0.1 g/l. Adsorption is well described by the Langmuir and Frendlich isotherms. The results of the work showed that the Fe-AС nanocomposite has a good potential for adsorption of phosphate ions from aluminate solutions, which was confirmed by SEM/EDS analysis.
RESEARCH OF ROLLING REFRIGERATORS AT CONVECTIVE HEAT EXCHANGE
Authors: Brovman T. V
Published: April 2024

The process of metal cooling by heat emission and convection is considered. Refrigerators used in modern varietal mills are calculated by the amount of heat transfer. A formula is proposed for calculating the cooling duration of the metal from 850 to 50 ° C, which gives a result 1.78 times less than the formula that does not take into account the effect of convective heat transfer. For workpieces of large thicknesses, the surface temperature differs from the average, so averaging the temperature by volume leads to errors. Refinement of the calculation of radiation surfaces increases the accuracy of calculations of cooling process.
STRUCTURE AND MECHANICAL PROPERTIES OF DEFORMED Mg-Sm-Tb-Zr ALLOYS
Authors: Luk'yanova E. A , Rokhlin L. L , Dobatkina T. V , Tarytina I. E , Martynenko N. S , Rybal'chenko O. V , Temralieva D. R , Straumal P. B , Dobatkin S. V
Published: April 2024

The structure, aging kinetics and mechanical properties of alloys of the new Mg-Sm-Tb-Zr system with different content and ratio of rare-earth metals obtained by hot pressing have been studied. A different effect of samarium and terbium on the process of recrystallization during deformation and the nature of hardening of alloys during additional aging depending on its duration as a result of the decomposition of a supersaturated magnesium-based solution has been established. The mechanical properties of the alloys after hot pressing and aging, including heating in the temperature range up to 300 °C, have been determined.
EFFECT OF REE ON THE SOLIDIFICATION OF НYPEREUTECTIC SILUMIN
Authors: Petrov I. A , Berezhnoy D. V
Published: April 2024

The theories and mechanisms explaining the processes of primary silicon modification in hypereutectic silumins are considered. The processes of crystallization of hypereutectic silumin treated with rare-earth elements (REE): yttrium, ytterbium, samarium, erbium, lanthanum and neodymium have been studied. The temperatures of phase transformations and parameters taking into account the solid phase separation in the crystallization interval have been obtained. Differences in crystallization parameters and the nature of solid phase evolution in alloys modified with yttrium, ytterbium, samarium, erbium, cerium and neodymium are shown. It is concluded that further research is necessary to clarify the mechanism of modification of primary silicon in REE hypereutectic alloys.
INVESTIGATION OF THE SPECIFIC ELECTRICAL CONDUCTIVITY OF RHENIUM-CONTAINING SOLUTIONS OF AMMONIUM CARBONATE AND CALCULATION OF ITS ACTIVATION ENERGY
Authors: Kuznetsova O. G , Levin A. M , Bol'shikh A. O , Levchuk O. M , Kaplan M. A
Published: April 2024

The specific electrical conductivity dependence of aqueous solutions of ammonium carbonate and solutions of the ammonium carbonate—ammonium perrenate system on the reagents content in the range of their concentration of 0.1—1.8 mol/l for (NH4)2CO3, 0.01—0.1 mol/l for NH4ReO4 and solution temperatures in the range of 20-50 °C were investigated by the conductometric method. A linear increase in electrical conductivity with an increase in the temperature of electrolytes and a nonlinear increase with an increase in the concentration of reagents was revealed. The temperature coefficients values of electrical conductivity and the activation energy values of electrical conductivity in the studied range of concentrations and temperatures are calculated. A decrease in the activation energy of electrical conductivity with an increase in the temperature of the solution was noted. The calculated value of the activation energy of electrical conductivity indicates the diffusive nature of charge transfer.
Early Jurassic Flood Basalt Volcanism on the Franz Josef Land Archipelago: Geological and Palynostratigraphical Data
Authors: Karyakin Yu. V. , Aleksandrova G. N. , Никишин А.М.
Published: April 2024

Biostratigraphic evidence of the presence of Early Jurassic flood basalts on the Franz Josef Land archipelago is presented. The flood basalts form layered section with two units, which is not discovered for Early Cretaceous basalts. The lower unit is composed by large-columnar basalts (colonnade), and the upper unit by small-columnar (entablature) chaotic-fan basalts. On the Hooker Island, the basalt flow is exposed on the Sedov Plateau, on the Lunacharsky Rock Cape and, possibly, on Al’banov Cape. On the southern slope of the Sedov Plateau, the basalt flow overlaps sands and sandstones, which contain palynoassemblage of the lower Toarcian. In the Lunacharsky Rock Cape outcrop, the underlying basalt sands are of the Pliensbachian to Early Toarcian chronostratigraphic interval. Apart from the Hooker Island, we observed basalts with the “colonnade/entablature” on three other islands: Scott Keltie, May and Leigh-Smith. The most complete section was found in the western part of the Leigh-Smith Island, where basalts are underlain and overlapped by sand units. The underlying sands in contact with basalts have a quenching zone. There is no quenching zone at the contact with the overlapping sands. A palynocomplex from the lower sand unit is early Toarcian in age. The palynocomplex found in the upper sand unit indicates its accumulation in the interval from the lower part of the late Toarcian to the early Aalenian. A palynological study of the underlying and overlying deposits of the basalt flow has shown that the flow is underlain by continental and coastal-marine sediments of the Pliensbachian to the upper part of the early Toarcian age interval. Basalt flow is overlain by the earliest late Toarcian–early Aalenian marine sediments. According to the modern chronostratigraphic scale, the age of the basalt flow can be estimated as approximately 180 million years, which is quite consistent with the earlier obtained 40Ar/39Ar data of 189.1 ± 11.4 million years. These data indicate that the basalt flow was formed during a narrow stratigraphic interval of the uppermost lower–earliest upper Toarcian.
Taxonomy and Biostratigraphical Significance of the Toarcian Bivalves of the Genus Meleagrinella Whitfield, 1885
Authors: Lutikov O. A. , Arp G. , Захаров В.А.
Published: April 2024

The morphology of the ligament block and outer parts of the shells of Toarcian bivalves of the genus Meleagrinella (family Oxytomidae Ichikawa, 1958) were studied. The phylogeny of Meleagrinella and Arctotis in the Toarcian was reconstructed on the basis of the conclusions on the evolution of the ontogeny of the ligament pit, made as a result of studying extensive material from Eastern Siberia and Germany, and taking into account the data on the microsculpture of the ostracum. A revision of the species “Monotis” substriata (Münster, 1831), which is widespread in the Toarcian deposits of Europe, Asia, and North America, was carried out. By comparing specimens from different stratigraphic levels of the Lower Toarcian of Eastern Siberia, North-East Russia, and Germany, three species were substantiated: Meleagrinella (Praemeleagrinella?) golberti sp. nov., M. (Clathrolima) substriata (Münster) and M. (Meleagrinella) prima sp. nov. Figures of the ammonite Tiltoniceras sp. ind., Upper Plinsbachian-Toarcian bivalves of the genus Meleagrinella and Upper Toarcian bivalves of the genus Arctotis are given. For the first time, a microsculpture of an ostracum of the Toarcian representatives of the genera Arctotis and Meleagrinella is depicted. In the Upper Pliensbachian–Lower Toarcian, a sequence of oxytomid taxa was established and, based on the Boreal ammonite scale, an assessment of their biostratigraphic significance was given. The sequence is represented by four species: (1) Meleagrinella (Praemeleagrinella) deleta (Upper Pliensbachian), (2) M. (Praemeleagrinella ?) golberti (Tiltoniceras antiquum, Harpoceras falcifer zones), (3) M. (Clathrolima) substriata (Dactylioceras commune Zone), (4) M. (Meleagrinella) prima (Zugodactylites braunianus, Pseudolioceras compactile zones).
Sources of the Paleoproterozoic Terrigenous Rocks of the Nizhnekhani Graben-Sincline, Western Part of the Aldan Shield on the U–Th–Pb (LA-ICP-MS) Geochronological and Nd Isotopic Studies: To the Question of Correlation of the Udokan Complex Deposits
Authors: Kovach V. P. , Adamskaya E. V. , Kotov A. B. , Berezkin B. I. , Timofeev V. F. , Popov N. V. , Plotkina Yu. V. , Skovitina T. M. , Fedoseenko A. M. , Zagornaya N. Yu. , Gorokhovsky B. M. , Кузнецов А.Б.
Published: April 2024

Paper discusses the results of U–Th–Pb (LA-ICP-MS) geochronological studies of detrital zircon and Sm–Nd isotopic studies of metaterrigenous rocks of the Udokan complex of the Nizhnekhani graben-syncline in the western part of the Aldan Shield. Based on the data obtained, it was found that the accumulation of terrigenous deposits of the Nizhnekhani graben-syncline occurred after 2.65 and up to 1.9 Ga, probably at the Paleoproterozoic stage of the development of the region. The igneous and metamorphic rocks formed at ca. 2.65, 2.71, 2.82–2.86, 2.99, 3.10–3.21, and probably 3.26–3.42 Ga ago within the Chara-Olekma geoblock, the zone of its junction with the West Aldan megablock and the Kurulta block of the Stanovoi suture zone, were the sources of detrital material. Metaterrigenous rocks of the Nizhnekhani graben-syncline were formed from sources with the Paleo- and Mesoarchean Nd model ages, while a significant contribution of the Paleoproterozoic juvenile material was established for the metasedimentary rocks of the Kodar-Udokan trough. Significant differences in the age and Nd isotopic characteristics of terrigenous deposit sources of the Nizhnekhani graben-syncline and the Kodar-Udokan trough suggest that they accumulated in isolated basins.
Composition and Age of Sources of the Lower–Middle Cambrian (?) Terrigenous Rocks from The Ernichny Formation in the Argun Massif, Eastern Part of the Central Asian Fold Belt
Authors: Smirnova Yu. N. , Kurilenko A. V. , Khubanov V. B. , Дриль С.И.
Published: April 2024

The paper presents the results of the mineralogical and geochemical studies of sandstones and siltstones of the Ernichny formation of the Argun series in the Argun continental massif, and the results of U–Pb (LA‑ICP-MS) dating for the detrital zircons from these rocks. It is established that the youngest detrital zircons from sandstone of the Ernichny Formation have age of 549–570 Ma. A maximum on the relative probability curve of zircon age corresponds to 566 Ma. These data determine the lower age limit of their accumulation on the border of the Ediacaran and Paleozoic age. According to the results of U–Pb dating of detrital zircon, the majority of detrital zircons from sandstones of Ernichny Formation are characterized by Neo- and Paleoproterozoic ages. The sources of zircons were Neo- and Paleoproterozoic igneous and metamorphic rocks that were widely developed within the Argun continental massif. In turn, the geochemical features of the terrigenous rocks of the Ernichny Formation, together with the presence of the poorly sorted and rounded clastic material in the studied samples, as well as the presence of interlayers of gravelstones, enabled us to establish that they were formed in a subduction-related setting.
Late Pliocene Gilbert Type Delta and Early Pleistocene Drainage System Changes in the Erzurum Basin, NE Turkey
Authors: Çelik H. , Trifonov V. G. , Tesakov A. S. , Sokolov S. A. , Frolov P. D. , Simakova A. N. , Shalaeva E. A. , Belyaeva E. V. , Yakimova A. A. , Zelenin E. A. , Latyshev A. V. , Bachmanov D. M. , Алчичек Дж.
Published: April 2024

Erzurum intermontane basin in north-eastern Turkey experienced terrigenous and carbonate sedimentation in Mio-Pleistocene. A Gilbert-type delta is described in the west of the basin. The delta deposits are dated to Late Pliocene based on bio- and magnetostratigraphy. The eroded surface of the delta is overlain by pebbles dated to Early Pleistocene by archaeological finds. The Erzurum Basin is the westernmost member in a row of intermontane basins that continues to the east with the Pasinler, Horasan, and Ararat basins that are drained by the Araxes River and its tributaries. It is likely that the paleo-Araxes River spread to the west in Late Pliocene and the studied delta was formed by its upper reaches that flowed into the water body of the Erzurum Basin. The delta deposits were covered by coarse alluvium in Early Pleistocene when the Erzurum Basin was tectonically isolated from the Araxes drainage system. In the latest Early Pleistocene or early Middle Pleistocene, the paleo-Araxes upper reaches were captured by the Euphrates River upper reaches that drain the Erzurum Basin now.
The Age and the Accumulation Conditions of the Upper Paleogene–Lower Neogene Kurshskaya Formation Stratotype (Kaliningrad Oblast) by Palynological Data
Authors: Kuzmina O. B. , Iakovleva A. I. , Mychko E. V. , Былинская М.Е.
Published: April 2024

The results of the palinologycal study of the Kurshskaya Formation stratotype (Primorsky quarry, Kaliningrad Oblast) are presented. In the lower part of the Kurshskaya Formation (Member of “chocolate” clays), a complex of dinoflagellate cysts with Areosphaeridium diktyoplokum, Glaphyrocysta semitecta, and Cordosphaeridium funiculatum of latest Eocene age was found. The formation is characterized by four spore-pollen assemblages: (1) Pinuspollenites–Inaperturopollenites–Sciadopityspollenites assemblage of latest Eocene age in the “chocolate” clays and in the lower part of brown sands; (2) Sequoiapollenites–Betulaepollenites betuloides assemblage of early Oligocene age in the lower part of the brown sands member; (3) Boehlensipollis hohli–Carpinipites carpinoides assemblage of early Oligocene age in the middle part of brown sands member; (4) Alnipollenites–Corylopollis assemblage of late Oligocene–early Miocene age in the upper part of the brown sands of the Kurshskaya Formation. The general age of the Kurshskaya Formation is terminal Eocene–early Miocene. In the lower parts of the Zamland Formation, which overlies the Kurshskaya Formation, the Pinuspollenites–Tricolporopollenites pseudocingulum–T. euphorii assemblage presumably of middle Miocene age was found. Based on the obtained palynological data, the conditions of sedimentation at the end of the Eocene–Oligocene–early Miocene in the South Baltic region are reconstructed. The regression of the sea basin began as early as the end of the Priabonian, the climate was still quite warm and humid, close to subtropical. Mesophytic mixed coniferous-broad-leaved forests grew along the shores of the strait, low-lying areas of land were occupied by marsh vegetation. Cooling at the Eocene/Oligocene boundary resulted in the appearance of hemlock in plant communities and an increase in the proportion of catkins (alder, birch, hornbeam). Presumably, in the late Oligocene–early Miocene, the proportion of small-leaved trees, especially alder and hazel, sharply increased in mesophytic forests, while the number of pine trees decreased. Wetter and warmer climatic conditions are assumed for the early Miocene: this time is characterized by an increase in the number of walnut, cypress, and Cyrillaceae. In the middle Miocene, the climate was still quite warm, but drier, and such moisture-loving species as podocarpus, spruce, glyptostrobus, and swamp cypress disappeared from plant communities.
THE POMMEL BASE OF A SWORD FROM SUZDAL OPOLYE: DECOR RECONSTRUCTION
Authors: Makarov Nikolay A. , Tereschenko Elena Yu. , Fedorina Anastasiya N. , Zaytseva Irina E. , Guryeva Polina V. , Kondratev Oleg A. , Kainov Sergey Yu. , Podurets Konstantin M. , Murashev Mikhail M. , Kovalenko Ekaterina S. , Yatsishina Ekaterina B.
Published: April 2024

The article presents the results of synchrotron and neutron visualization of a unique find – the iron pommel base sword unearthed during the works of the Suzdal archaeological expedition of the Institute of Archaeology RAS at the settlement of Krapivye 10 in Suzdal vicinity. The studies were conducted at National Research Centre “Kurchatov Institute”, their task being to restore the pattern of a partially preserved decor on a heavily corroded object with non-destructive methods. The research revealed an inlaid decor made of silver and copper-alloy wires, which made it possible to identify the type of pommel (type V, according to J. Petersen’s typology) and date it from the middle – second half of the 10th century. The find is among the earliest ones in Krapivye 10, a small settlement that emerged in the depths of ravine systems in the middle – second half of the 11th century.
HOARD OF JEWELLERY AND HORSE GEAR OF THE 5th–4th CENTURIES BC FROM BRYANSK REGION
Authors: Stolyarov Evgeny V. , Radiush Oleg A.
Published: April 2024

The paper discusses a hoard of the Early Iron Age from the territory of Bryansk Region. The hoard includes iron cheek-pieces, a brow band, bronze bridle plaques, as well as bracelets – smooth cast and hollow cast ones made using the technique of lost wax investment casting. Objects were placed in a crude handmade pot. The unique complex dating back to the 5th–4th centuries BC was found in the area of the Yukhnovo archaeological culture. The completeness of the analyzed hoard and the circumstances of its finding have direct analogies among the hoards originating from the southern coast of the Baltic Sea. It is possible that the hollow bracelets from the hoard are an imitation of samples found on the territory of Polish Pomerania and adjacent regions.
A WOODEN MODEL OF THE CHURCH OF THE HOLY SEPULCHER IN RUSSIA AND CONRAD SCHICK
Authors: Vakh Kirill A.
Published: April 2024

This article discusses the fate of a scale model of the Resurrection (Holy Sepulcher) Church and parts of the old city of Jerusalem made in 1863 by Conrad Schick specifically for Russia, as well as another Schick’s visual aid of the early 1860s associated with the model.
ARCHAEOLOGICAL EVIDENCE OF IRON SMELTING IN BYZANTINE AND EARLY ISLAMIC JERICHO
Authors: Voroshilov Alexey N. , Voroshilova Olga M.
Published: April 2024

Excavations in Jericho made it possible to reveal a notable complex of ferrous metallurgy. Archaeological evidence of iron smelting is represented by numerous slags, dozens of iron blooms, and three bloomery furnaces. They are localized mainly in the cultural layer surrounding the pottery kilns. The statistics of the finds indicate a fairly active production of iron in the Jericho workshop, where 59 small iron blooms and their fragments were found. The shape of whole blooms corresponds to a bowl-shaped depression in the lower part of small bloomery furnaces. The foundations of three similar structures were found, each of them located in the immediate vicinity of a pottery kiln. The chronology of iron production in Jericho corresponds to the time of functioning of the pottery workshop at the monastic-pilgrimage complex of the second half of the 6th – the first half of the 8th century. The archaeological context proves that ferrous metallurgy was an integral part of the production processes in the workshop throughout the entire period of its functioning. In addition, the multifunctionality of the production complex in Jericho is confirmed, which most likely provided for the vital needs of the inhabitants of a fairly large household in various types of ceramic vessels and bloomery iron throughout the late Byzantine and Umayyad periods of Palestine history.
GAME BIRDS IN THE ECONOMY OF THE POPULATION OF BEREZOV (BASED ON THE RESULTS OF ARCHAEOZOOLOGICAL ANALYSIS)
Authors: Lobanova Tatiana V. , Bachura Olga P. , Martynovich Nikolay V. , Vizgalov Georgy P. , Slesarenko Inna V.
Published: April 2024

Based on the evidence from osteological collection of birds (over 7,000 specimens), the hunting of game by the population of the town of Berezov in Modern period was reconstructed. The study identified species composition of game birds and conducted an analysis of the ratio of skeletal elements, fragmentation of bones, and external influences. The main purpose of bird hunting was to obtain an additional source of meat for the population of the town. Over time, the relative significance of poultry in the diet of the urban population decreased, but the intensity of game hunting remained constantly high. The game was hunted all year round. Spring-summer hunting for waterfowl was a dominant type. In winter, they hunted mainly for wood grouse and ptarmigan. Based on the average weight of each species, the authors calculated the potential amount of meat that can be obtained from the hunting for the three main groups of birds. It is shown that in the cold season, the supply of additional meat products from bird hunting decreased almost threefold compared with the spring-summer time.
Alzheimer’s Disease: A Search for the Best Experimental Models for the Decoding of the Cellular and Molecular Mechanisms of the Development of the Diease
Authors: Gorina Y. V. , Vlasova O. L. , Bolshakova A. V. , Salmina A. B.
Published: April 2024

Alzheimer’s disease is the most common type of dementia associated with cognitive decline, such as memory and visuospatial skills. Insufficiently effective treatments have prompted the creation of experimental animal models capable of reproducing the pathology of Alzheimer’s disease, especially at the presymptomatic stage, in order to develop and study preventive and therapeutic strategies. To date, none of the developed animal models fully reflects the entire spectrum of neuropathological and cognitive impairments observed in the development of Alzheimer’s disease in humans. However, each model created allows, to one degree or another, to study various aspects of the pathogenesis of the disease, providing an important understanding of the key pathological changes that may occur during its development. In this review, we present a summary of the neuropathological features of Alzheimer’s disease and their relationship to cognitive impairment in the animal models currently in use. We also present in a comparative aspect the features of the development of Alzheimer’s type neurodegeneration using the example of 2 models – genetic and injection, which will make it possible to determine optimal approach when choosing a model for implementing research tasks.
Interhemispheric Symmetry and Asymmetry of Absence Type Spike-Wave Discharges Caused by Systemic Administration of Pentylenetetrazole
Authors: Ershova A. S. , Suleymanova E. M. , Grishchenko A. A. , Vinogradova L. V. , Sysoev I. V.
Published: April 2024

Absence epilepsy is a specific generalized non-convulsive form occurring almost exclusively in children and adolescents. It is traditionally thought that the resulting seizure is completely generalized in the cortex of both hemispheres, as seen in humans on surface electroencephalograms and magnetoencephalograms. However, most studies were performed on animals, mainly rats – genetic (WAG/Rij and GAERS lines) and pharmacological models, since signals not only from the cortex, but also from subcortical structures such as the thalamus must be measured, what cannot be done on humans, who have no medical indications for intracranial surgery. In animals, measurements of local field potentials were almost always made from one hemisphere in order to cover the maximum number of brain structures involved. At the same time, the degree of synchrony of seizure onsets and terminations in different hemispheres in animals was practically not studied, and the markup itself in the vast majority of cases was done on the basis of one channel from motor or somato-sensory cortex. This work aims to reveal differences and similarities in the course of spike-wave discharges (the main encephalographic marker of absence seizures) in the cortex of the two hemispheres in a known pharmacological model of rats exposed to pentylentetrazole. For discharge detection, a method of automatic discharge marking is proposed and its sensitivity and specificity are evaluated using records of nine animals. We used it to mark seizures in symmetrical cortical sites from both hemispheres separately. According to the results of the analysis of seizure duration it turned out that for five out of nine animals the distribution of discharges significantly differed between the hemispheres, and for the other four was equal. Consequently, in the rat model, spike-wave activity may be generalized both symmetrically and asymmetrically, which may be due to individual peculiarities or different discharge triggering scenarios.
Use of Colour Coding to Assess the Effects of Haloperidol on Animal Behaviour in the Open Field Test
Authors: Makarov M. S. , Sysoev Yu. I. , Guzenko M. K. , Prikhodko V. A. , Korkotian E. , Okovityi S. V.
Published: April 2024

Development of novel approaches to behavioural test data analysis is of considerable importance to fundamental research as well as experimental neuropharmacology. Antipsychotic agents used to treat positive and negative symptoms in schizophrenia are of particular interest to current research. Despite that antipsychotics exert potent effects on animal behaviour in simple behavioural tests, they can be difficult to distinguish from other central nervous system-depressing agents, such as sedatives. In this paper, we propose colour coding of video sequence as a method for the analysis of behavioural pattern structure in rats, using the effects of haloperidol, a typical antipsychotic, in the Open field test, as an example. The study was carried out in outbred albino male rats weighing 250–300 g. 3 min long video sequences of rat behaviour in the Open field were processed using Python and the OpenCV library in the Google Colab 3 environment. Colour coding allowed for the marking up and overlaying in a single frame the present (t = 0), nearest-future (t = 0.33 s), and the less-near-future (t = 1.66 s) location of an animal in the arena. Using the proposed method, we were able to detect specific effects of haloperidol on animal behavioural patterns which are undetectable using conventional behavioural data analysis techniques for this test. The three-timepoint colour coding method we propose proved effective for data analysis and processing, and the results were in accordance with other author’s data, obtained using computerized as well as conventional visualization techniques.
Obesity and Aging. General Aspects
Authors: Dyleva Yu. A. , Belik E. V. , Gruzdeva O. V.
Published: April 2024

Obesity is associated with an increased risk of acute and chronic diseases, including hypertension, stroke, myocardial infarction, cardiovascular disease, diabetes, cancer, and reduces life expectancy by up to 20 years, increasing the risk of premature death. It has been shown that the metabolic changes associated with obesity are similar to those observed with aging. Thus, obesity and aging have a similar range of phenotypes, such as impaired genome integrity, mitochondrial function, accumulation of intracellular macromolecules, weakened immunity, and systemic inflammation. The commonality of mechanisms may underlie the acceleration of aging processes, both at the molecular and systemic levels. Thus, understanding the mechanisms of adipose tissue dysfunction in obesity can provide insight into the processes that contribute to the metabolic dysfunction associated with the aging process. The current review will examine the molecular and cellular mechanisms that underlie obesity and aging, and how obesity can activate the aging process, initiating the early onset of aging-associated chronic diseases.
GABAergic Mechanisms of the Brain Tolerance to Hypoxia in Lower Vertebrates
Authors: Kolesnikova E. E.
Published: April 2024

Hypoxic/ischemic brain injuries a major medical challenge. One of the approaches to the development of therapeutic interventions is to establish the pathways of survival for neurons in tolerant to O2 deficiency vertebrates, which could suggest the ways to mitigate hypoxic catastrophe for separate cells under oxygen starvation. Metabolic depression is considered to be a universal strategy for the survival of hypoxia tolerant animals; however, the details of the mechanism of brain metabolism limitation with a decrease in PO2 have not hitherto been established. Under oxygen starvation, an increase in the extracellular concentration of inhibitory neurotransmitters can be one of the significant links in the apparatus for suppression of electrical activity, which makes it possible to reduce energy demand. GABA (γ-aminobutyric acid) serves as a universal inhibitory neurotransmitter in the CNS of higher and lower vertebrates, the functioning of which is associated with the metabolism suppression and leveling the consequences of an energy failure. GABA is found in various taxonomic groups of vertebrates. This review considers strategies for GABA involvement in the mechanisms of ensuring a brain tolerance to oxygen starvation in representatives of various taxonomic groups of lower vertebrates (cyclostomes, cartilaginous and bony fish, amphibians, reptiles), which are distinguished by a most pronounced ability to survive under acute and chronic hypoxia/anoxia.
The Effect of Prolonged Emotional and Painful Stress on the Expression of Proinflammatory Cytokine Genes in Rats with High and Low Excitability of the Nervous System
Authors: Shalaginova I. G. , Tuchina O. P. , Turkin A. V. , Vylegzhanina A. E. , Nagumanova A. N. , Zachepilo T. G. , Pavlova M. B. , Dyuzhikova N. A.
Published: April 2024

Stress plays an important role in the pathogenesis of anxiety and depressive disorders. Neuroinflammation is considered as one of the mechanisms by which stress alters the molecular and cellular plasticity in the nervous tissue, which leads to a violation of the functions of the central nervous system. The contribution of genetically determined features of the nervous system to the development of post-stress neuroinflammation has not been sufficiently studied. In this study, the dynamics of poststress changes in the mRNA levels of the il1ß and tnf genes of proinflammatory cytokines interleukin-1-beta (IL-1ß) and tumor necrosis factor (TNF) in the blood and in the brain in two rat strains with high and low excitability thresholds of the nervous system (HT and LT) was evaluated. Changes in IL-1ß and TNF mRNA levels were assessed by real-time PCR 24 h, 7, 24 and 60 days after prolonged emotional and painful stress in the blood and three brain structures involved in the development of post-stress pathology (prefrontal cortex, hippocampus, amygdala). In highly excitable rats of the LT strain, the level of IL-1ß mRNA in the hippocampus and amygdala increased compared to the control 24 days after the end of stress, in low-excitable animals of the HT strain, an increase in the level of IL-1ß mRNA was detected only in the hippocampus at the same time. The TNF mRNA level did not change in any of the strains at any of the time points after stress. Genetically determined excitability of the nervous system is a promising marker of individual vulnerability to stress, manifested in post-stress disorders associated with the characteristics of the formation and dynamics of neuroinflammation.
The Maintenance of AMPK Activity Eliminates Abnormally Accelerated Differentiation of Primary Myoblasts Isolated from Atrophied Rat Soleus Muscle
Authors: Vilchinskaya N. A. , Mirzoev T. M. , Shenkman B. S.
Published: April 2024

Mechanical unloading of skeletal muscles leads to the development of atrophic processes and a decrease in the total number of satellite cells (SCs) that are involved in muscle regeneration. In vitro studies revealed an increased differentiation of myoblasts derived from rat soleus muscle after an unloading-induced decrease in AMP-activated protein kinase (AMPK). AMPK is necessary for the activation of SCs and also participates in the regulation of myoblast proliferation and differentiation. It can be assumed that a decrease in the activity of AMPK after mechanical unloading can contribute to the acceleration of myoblast differentiation. The main purpose of this study was to elucidate a possible role of AMPK in the regulation of differentiation of myoblasts isolated from rat soleus muscle after mechanical unloading. To test this hypothesis, a specific AMPK activator, AICAR, was used to prevent a decrease in AMPK activity during differentiation of myoblasts isolated from rat soleus muscle after 7-day unloading. Immunocytochemistry, PCR-RT and Western blotting were used to assess changes during myoblast differentiation. In differentiating myoblasts derived from the unloaded soleus muscle there was a significant decrease in AMPK (Thr172) and ACC (Ser 79) phosphorylation levels, an increase in myotube differentiation index, myoblast fusion factors and the expression of myogenic regulatory factors (MRF). Furthermore, there was a decrease in the expression of slow myosin heavy chains (MyHC) and an increase in the expression of fast MyHC isoforms. AICAR treatment of differentiating myoblasts obtained from the unloaded soleus muscle prevented a decrease in AMPK and ACC phosphorylation, returned the expression levels of MRF and fast isoforms of MyHC to the control levels as well as maintained the expression of slow MyHC. Thus, abnormally accelerated differentiation of myoblasts isolated from atrophied rat soleus muscle can be compensated by maintaining the control levels of AMPK activity using AICAR.
The Changes of the Infra-Slow EEG Fluctuations of the Brain Potentials under Influence of Infra-Low Frequency Neurofeedback
Authors: Grin-Yatsenko V. А. , Ponomarev V. А. , Kropotov J. D.
Published: April 2024

This study presents a comparison of the effect on EEG electrical activity in the range of infraslow frequencies of two methods: infra-low frequency EEG biofeedback and heart rate variability training. The study involved 17 healthy subjects aged 21 to 50 years with minor symptoms of a physiological or psychological nature, who did not have a history of neurological or psychiatric diseases. To evaluate the results of the training, we analyzed the spectral power of slow EEG oscillations during the performance of the attention test (Visual Go/NoGo), recorded before and after twenty sessions of biofeedback. Both the subjective assessment of the physiological and psychological state and the results of the visual test showed more pronounced positive changes under the influence of EEG biofeedback compared to the cases of heart rate variability training. A significant increase in the amplitudes of oscillations in the infraslow EEG range was observed only after EEG biofeedback.
Vascular Effects of Perinatal Hypoxia in the Early Postnatal Period in Rats
Authors: Shvetsova A. A. , Khukhareva D. D. , Simonenko S. D. , Khlystova M. A. , Borzykh A. A. , Gaynullina D. K.
Published: April 2024

The normal functioning of the vascular system in early ontogenesis can be altered by adverse effects affecting the organism of the fetus / newborn during pregnancy, during or after childbirth. However, at the moment there is not enough data on the “acute” (immediately after exposure) and “delayed” (after several days) effects of short-term (within several hours) perinatal normobaric hypoxia on the functioning of the peripheral vascular system of the systemic circulation in early ontogenesis in mammals. The aim of this work was to study the “acute” and “delayed” effects of a single normobaric hypoxia on the functioning of the arteries of the systemic circulation in early postnatal ontogenesis. The contractile responses of the saphenous artery of rats aged 10–14 days were studied in isometric myograph. Acute normobaric hypoxia (8% O2) was simulated for 2 hours in 10-day-old rat pups. The selected hypoxia regimen did not lead to changes in arterial contractile responses to the α1-adrenergic agonist methoxamine either immediately after exposure or several days later. Endothelium-dependent relaxation of arteries to acetylcholine also did not differ between groups. Hypoxia did not change the contribution of anticontractile pathways associated with nitric oxide and Kv7 channels, as well as the pro contractile role of Rho-kinase. Thus, according to the presented results, short-term normobaric hypoxia on the 10th day of life in rat pups does not lead to either “acute” or “delayed” changes in the regulation of the tone of the peripheral arteries of the systemic circulation in the early postnatal period.
Mechanisms of Physiological Angiogenesis
Authors: Ivanov A. N. , Chabbarov Yu. R.
Published: April 2024

Angiogenesis is the formation of blood vessels from existing vasculature to provide n-ormal tissue perfusion. Angiogenesis is also necessary for the processes of growth and regeneration. Angiogenesis attracts the attention of researchers from the position of its therapeutic regulation: enhancement can contribute to significant progress in the treatment of ischemic diseases, and inhibition is actively studied for the treatment of neoplastic diseases. Regulation of angiogenesis is impossible without accurate knowledge of its mechanism. There are two fundamental pathways for angiogenesis: sprouting angiogenesis, which is mediated by an existing vessel’s endothelial cells migration into the extracellular matrix to form a vessel in the direction of angiogenic stimuli, and intussusceptive angiogenesis, which is mediated by dividing the formed vessel into two new ones as a re-sult of the formation of a partition inside it that separates two independent lumens. This review examines the main stages of each type of physiological angiogenesis, their mechanisms and regulation.
Resistance of Embryonic Chick Atria to Inhibition of HCN-Channels and Components of the “Ca2+-Clock”
Authors: Lebedeva E. A. , Gonotkov M. A.
Published: April 2024

Despite its medical importance, the cellular mechanisms activity and the contribution of various ion channels of embryonic heart automatism are not yet fully understood. In this study we investigated the effects of specific ion-channel inhibitors on the generation of action potentials in pacemaker cells of the right atrium in chicken embryos (HH36). We used microelectrode technique and evaluated the sensitivity of pacemaker cells to ivabradine (inhibitor of HCN-channels, through which the hyperpolarization-activated current, If), ryanodine (agonist of ryanodine receptors) and SN6 (inhibitor of Na+/Ca2+-exchange). It was found that the right atrium cells have a phase of slow diastolic depolarization. However, these cells were not sensitive to ivabradine (3 μM). We did not register significant changes in the electrophysiological parameters of action potentials.When ryanodine (1 μM) and SN6 (10 μM) were added to the perfusion solution, we observed similar effects: spontaneous rate the generation of action potential increased by 15%. Disturbance of rhythmic activity or disruption of the generation of electrical impulses were not observed in right atrial samples of chicken embryos. The obtained results allow us to conclude that, at this of embryonic development stage, HCN4-channels, ryanodine receptors, and the Na+/Ca2+-exchange are not decisive for maintaining the automatism of the right atrial cells in the chick embryo. We assume that the ion currents flowing through these channels are important in electrophysiology in adult animals, but they have a modulating function in the embryonic myocardium.
Markers of Neuroontogenesis in the Stress-Hyporesponsive Period: Comparison of Laboratory Rodents and Humans
Authors: Manolova A. O. , Gulyaeva N. V.
Published: April 2024

Nowadays there is a number of neuropsychiatric diseases that are considered to be associated with early life stress. Various models are used on laboratory rodents to elucidate the mechanisms of the pathogenesis of psychopathologies that cannot be studied in humans. For successful translation of data, it is necessary to compare the processes of neuroontogenesis at the moment of exposure and subsequent periods. There are many comparative studies concerning the development of neurons and neuronal networks, as well as changes in the hypothalamic-pituitary-adrenal axis. In recent years, it has been reliably shown that glial cells are an important participant in both brain development and its response to stress. The opinion that it is microglia and astrocytes that represent the most promising targets for therapeutic intervention in stress-related diseases is supported. However, there are still no comparative analytical studies covering both stress-realizing systems and neuronal and glial markers of development. This review fills this gap. Here we provide a new perspective for considering the problems of modeling childhood stress and translating the data obtained. The presented analysis, on the one hand, supplements the existing understanding of the correspondence between the stages of brain development in laboratory rodents and humans, and, on the other hand, marks points of growth and raises new questions for researchers of stress in early ontogenesis.
Words Listening Related Electroencephalography Reactivity in Children of Preschool and Primary School Age
Authors: Nacharova M. A. , Nacharov D. V. , Pavlenko V. B.
Published: April 2024

An analysis was made of event-related changes in the electroencephalogram (EEG) spectrum during the auditory perception of nouns in 83 typically developing children aged 4 to 10 years, including 50 children of preschool age and 33 children of primary school age. Following intergroup differences were revealed: in preschool children, neuronal systems are more involved in word processing, the activity of which is reflected in extensive desynchronization of alpha and synchronization of theta activity in the frontal zones of the left hemisphere. The EEG reactivity of primary school children is characterized by bilateral and more pronounced theta synchronization, which indicates an increased intensity of lexico-semantic operations, as well as a decrease in the background and an increase in the evoked theta activity. In children of this group, EEG synchronization in the beta range was also observed, represented by separate flashes and most pronounced in the frontal leads, which is typical for more mature speech processing mechanisms. The study results are important for clarifying the mechanisms of speech understanding in typically developing preschool and primary school age children.