bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonatization of Serpentinites of the Mid-Atlantic Ridge: 1. Geochemical Trends and Mineral Assemblages
Authors: Silantyev S. A. , Krasnova E. A. , Badyukov D. D. , Zhilkina A. V. , Kuzmina T. G. , Gryaznova A. S. , Sherbakov V. D.
Published: April 2024

Abyssal peridotite outcrops compose vast areas of the ocean floor in the Abyssal peridotite outcrops compose vast areas of the ocean floor in the Atlantic, Indian, and Arctic Oceans, where they are an indispensable part of the structure of the oceanic crust section formed in low-velocity oceanic spreading centers. The final stage in the evolution of abyssal peridotites in the oceanic crust is their carbonatization, which they undergo on the surface of the ocean floor or near it. The main goal of this study was reconstruction of the geochemical trends accompanying the carbonatization of abyssal peridotites using the example of MAR ultramafic rocks and to identify the main factors that determine their geochemical and mineralogical differences. It is shown that variations in the composition of rock-forming minerals and their characteristic assemblages indicate that the initial stages of carbonatization of abyssal peridotites occur in intra-crustal conditions simultaneously with the serpentinization of these rocks. The final stage in the crustal evolution of abyssal peridotites is their exposure to the surface of the ocean floor, to which they are transported along the detachment faults. Here, abyssal peridotites in close association with gabbro form oceanic core complexes, and the degree of their carbonatization sharply increases with the duration of their exposure on the surface of the ocean floor. The presented data made it possible to qualitatively reconstruct the sequence of events that determined the mineralogical and geochemical features of carbonatized abyssal peridotites of the MAR.
High Fractionated Granites of the Raumid Massif (S. Pamir): O-Isotope and Geochemical Study
Authors: Dubinina E. O. , Avdeenko A. S. , Volkov V. N. , Kossova S. A. , Kovalchuck E. V.
Published: April 2024

The processes of crystallization differentiation, retrograde isotopic exchange, and autometamorphism are considered using the “natural laboratory” – Eocene granites of the Raumid massif, which has eight intrusion phases. The work is based on a comprehensive (oxygen isotope, petrographic, geochemical) study of representative samples of each of the intrusion phases of the massif. Isotopic and geochemical studies of rock-forming minerals (Qz, Pl, Kfs, Bt), as well as their altered varieties, have been carried out. The geochemical features of the Raumid’s granites are correspond to both A-type granites and highly fractionated I-type granites. We show that the rocks of the Raumid massif are not the geochemical analog of the Qiangtang Eocene granitoids of the Central Tibet and the Vanj complex, as previously assumed (Chapman et al., 2018). The differentiation conditions for acidic melts that formed the Raumid pluton (T = 750–800°C, P = 4.5–7.8 kbar with predominant Pl crystallization) were estimated. The intrusion of melts into the hypabyssal zone proceeded at least in two stages: early (γ1–γ3) and late (γ4–γ8), although it is possible that the rocks of the γ7 and γ8 phases belonged to a separate stage. The closing temperature of the oxygen isotopic system of quartz (Тq) varies from 420 to 610°C, which indicates a wide range of cooling rates for these rocks. The effect of the multiphase nature of melt intrusion on the Тq and apparent cooling rates is considered. The study of altered and unaltered minerals makes it possible to establish that autometamorphism partially overlapped with the retrograde oxygen isotope exchange in the cooling rock. The modelling of the δ18О values of feldspars during autometamorphism in a system closed with respect to fluid show that the Pl saussuritization and Kfs kaolinitization proceeded at a limited fluid/mineral ratio (W/M = 0.3–0.05), which could be provided by aqueous fluid separated during the Raumid pluton cooling.
Subduction and Oceanic Magmatism Records in Plutonic Rocks of the Kamchatsky Mys Ophiolite, Eastern Kamchatka
Authors: Bazylev B. A. , Portnyagin M. V. , Savelyev D. P. , Ledneva G. V. , Kononkova N. N.
Published: April 2024

The paper presents petrographic, mineralogical, and geochemical data on dunites, pyroxenites, peridotites, and gabbroids of the Kamchatsky Mys ophiolite. These data were acquired to distinguish cogenetic assemblages of igneous rocks, gain an insight into their geodynamic settings, and test various criteria of genetic links between the different magmatic rocks of ophiolites. The ultramafic and mafic rocks are shown to belong to two series, which differ in the compositions of the primary minerals, bulk rocks, and estimated trapped melts. The rocks of these series are found out to have been produced by geochemically different melts in different geodynamic settings, and during different episodes of mantle magmatism. The rocks of the high-Ti series (gabbro of the Olenegorsk massif, dunite and melanogabbro xenoliths in them, and vein gabbro in these xenoliths) crystallized from N-MORB melts in an oceanic spreading center. The rocks of the low-Ti series (dunite, pyroxenite, and gabbro veins in the residual spinel peridotites of the Mount Soldatskaya massif, as well as pyroxenite, peridotite, and gabbro alluvium and diluvium in the central and western parts of the peninsula) crystallized from water-rich boninite melts in relation to initial subduction magmatism. Taken into account the absence of boninite lavas from the Kamchatsky Mys ophiolite, the plutonic ultramafic rocks (including the rocks of the veins) might be the only evidence of subduction boninitic magmatism in the ophiolites. It was demonstrated that conclusions about the geodynamic settings of plutonic ultramafic and mafic rocks and recognition of cogenetic relations of these rocks with spatially associated basalts are more reliable when derived from the compositions of the trapped melts, which are estimated from their bulk geochemistry and primary mineral compositions, than when they are based on the mineral compositions only.
The origin of olivine basalts from Medvezhya Mount (Avachinsky group of volcanoes, Kamchatka): The evidence of assimilation of sulfide-bearing cumulates
Authors: Savelyev D. P. , Gorbach N. V. , Portnyagin M. V. , Shcherbakov V. D.
Published: April 2024

The role and conditions of liquid immiscibility and crystallization of sulfide phase during evolution of subduction related magmas remains to be a debated topic, which bears relevance to mechanisms of porphyry copper deposit formation and evolution of the continental crust. We studied rare volcanic rocks with inclusions of magmatic sulfides in olivine – the basalts of Medvezhya Mount in the Avachinsky group of volcanoes. The rocks belong to primitive (Mg# = 66 mol. %) middle-K island arc olivine basalts. Olivine with normal zoning predominate (~98%) among phenocrysts. The olivine compositions are typical for Kamchatka basalts, except for an unusual trend of increase of MnO content from 0.20 to 0.55 wt. % and decrease of Fe/Mn from 60 to 35 with change of olivine composition from Fo87.8 to Fo78.2. Olivines of this group contain numerous inclusions of minerals of the spinel group varying in composition from chromium spinel to magnesian magnetite. Olivine phenocrysts with sulfide inclusions are characterized by the absence or weak reverse zoning and reduced contents of Ca, Ni, Mn, Cr, and Al. The estimated crystallization temperatures for olivines of the prevailing type are 1036–1241°C, for sulfide-bearing olivines – 1010–1062°C. The data suggest that crystallization of the main olivine population occurred under relatively shallow conditions and was accompanied by strong oxidation of the magmas. On the contrary, the zoning and composition features of sulfide-bearing olivine suggest its xenogenic origin and probable crystallization at conditions of deep crust from low temperature water-rich and/or low-Ca magmas. The results obtained confirm the possibility of saturation of oxidized island-arc magmas with sulfide phase at lower crustal conditions, but show that this process is rare and not typical for low-pressure crystallization stage.
Thermodynamic Model of the Fluid System H2O–CO2–NaCl–CaCl2 at P-T Parameters of the Middle and Lower Crust
Authors: Ivanov M. V.
Published: April 2024

Based on the earlier obtained equations of state for the ternary systems H2O–CO2–CaCl2 and H2O–CO2–NaCl, an equation of state for the four-component fluid system H2O–CO2–NaCl–CaCl2 is derived in terms of the Gibbs excess free energy. A corresponding numerical thermodynamic model is build. The main part of the numerical parameters of the model coincides with the corresponding parameters of the ternary systems. The NaCl–CaCl2 interaction parameter was obtained from the experimental liquidus of the salt mixture. Similar to the thermodynamic models for H2O–CO2–CaCl2 and H2O–CO2–NaCl, the range of applicability of the model is pressure 1–20 kbar and temperature from 500°C to 1400°C. The model makes it possible to predict the physicochemical properties of the fluid involved in most processes of deep petrogenesis: the phase state of the system (homogeneous or multiphase fluid, presence or absence of solid salts), chemical activities of the components, densities of the fluid phases, and concentrations of the components in the coexisting phases. The model was used for a detailed study of the phase state and activity of water on the H2O–CO2–salt sections when changing the ratio \( {{{{x}_{{{\text{NaCl}}}}}} \mathord{\left/
{\vphantom {{{{x}_{{{\text{NaCl}}}}}} {\left( {{{x}_{{{\text{NaCl}}}}} + {{x}_{{{\text{CaC}}{{{\text{l}}}_{{\text{2}}}}}}}} \right)}}} \right.} {\left( {{{x}_{{{\text{NaCl}}}}} + {{x}_{{{\text{CaC}}{{{\text{l}}}_{{\text{2}}}}}}}} \right)}} \) from 1 to 0. Changes in the composition and density of coexisting fluid phases at a constant activity of water and changes in the total composition of the system are studied. A set of phase diagrams on sections H2O–NaCl–CaCl2 for different mole fractions of CO2 is obtained. Pressure dependencies of the maximal activity of water in the field of coexisting unmixable fluid phases are obtained for several salt compositions of the system. Due to removal of restrictions resulting from a smaller number of components in ternary systems, the thermodynamic behavior of systems with a mixed composition of the salt is significantly differ from the behavior of those with a single salt component.
Experimental Investigation of the Interaction of Amphibole with Highly Salted H2O-NaCl-KCl Fluid at 750°C, 700 MPa: Application to Alkaline Metasomatism of Amphibole Rocks
Authors: Khodorevskaya L. I. , Varlamov D. A. , Safonov O. G.
Published: April 2024

The article presents experimental data on the interaction of amphibole with NaCl-H2O and (K, Na)Cl-H2O solutions at varying salt content. When interacting with the H2O-NaCl fluid, amphibole remains the predominant mineral in all experiments. In addition to it, Na-phlogopite, plagioclase, and nepheline/sodalite are formed. At \({{a}_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}}\) 0.6, amphibole melts. When amphibole interacts with the H2O-NaCl-KCl fluid at \({{X}_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}}\) 0.40 and ХKCl/(ХKCl + ХNaCl) in the fluid, defined as ХNaCl = 0.506 – 0.84ХKCl, the amphibole is replaced by an association of nepheline with acid plagioclase, sodalite, and biotite. At ХKCl/(ХKCl + ХNaCl) 0.3, nepheline, sodalite, and plagioclase become unstable, K-feldspar appears, and biotite, clinopyroxene, and amphibole remain. At ХKCl/(ХKCl + ХNaCl) 0.5, the association Cpx + Bt + Kfs + Grt (grossular–andradite) is stable. Thus, the grossular–andradite garnet is an indicator of high potassium activity in fluids, while nepheline is an indicator of high sodium activity. Na → K isomorphism is observed in amphibole and biotite, and Ca → Na isomorphism in clinopyroxene, but in general these minerals (unlike nepheline and garnet) remain stable in the range of wide K/Na variations in the fluid. Clinopyroxene in experiments corresponds to Ca-Fe-Mg compositions with varying, sometimes high aluminium content, amphiboles belong to the pargasite-hastingsite composition. With an increase in \({{a}_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}}\) (\({{X}_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}}\) 0.57), i.e. a decrease in the gross salinity of the fluid, melts appear, the composition of which varies from trachyte to phonolitic. As ХKCl/(ХKCl + ХNaCl) increases in fluids, the alumina content of melts decreases. An increase in the total salinity of the fluid leads to an increase in the content of potassium in the melt and a decrease in the content of chlorine in it. Experiments have shown that the interaction of amphibole with fluids containing high concentrations of NaCl and KCl leads to the formation of mineral associations typical of alkaline metasomatism of amphibole rocks and concomitant HCl enrichment of the fluid phase. The replacement of fluids with a high saline component by highly acid ones leads to the leaching of Ca, Mg, Fe from metamorphic rocks, their transport and redeposition. Thus, in some cases, a significant removal of FeO, MgO, CaO is a consequence of the interaction of host rocks with water-salt solutions.
Metasomatic Transformation of Amphibolites into Corundum-Bearing Plagioclasites: Zoning, Numerical Model of the Process (on the Example of the Unique Khitostrov Mineral Deposit, Fennoscandian Shield)
Authors: Bushmin S. A. , Kol’tsov A. B. , Lebedeva Yu. M. , Savva E. V.
Published: April 2024

The paper presents the results of a study of desilicated rocks of the middle crust at the level of amphibolite facies using the example of corundum-bearing plagioclasites developing over the metabasites at the unique Khitostrov mineral deposit in the Belomorian-Lapland orogen of the Fennoscandian Shield. The main attention is paid to new geological data, documentation and analysis of metasomatic zoning, determination of the P-T conditions of its formation, and a model of the metasomatic process.
Clarification of the Regional Methodology for Calculating Potential Soil Flushing from Meltwater for the Northern Forest-Steppe of Central Siberia
Authors: Golubev I. A.
Published: April 2024

Abstract—The need to verify, modernize and refine existing models for calculating potential soil flushing from the effects of meltwater is due to the small number of studies of this type of erosion in the forest-steppe zone of Central Siberia and, as a consequence, the inability to reliably determine how accurate the calculation methods are in their current form under these conditions. For the agricultural zone of the Krasnoyarsk Territory, a regional model has been developed for calculating potential soil flushing based on a Universal equation and the Instructions’ formula. This paper presents the results of its verification, performed using the results of the author’s field measurements of soil flushing from meltwater by measuring removal cones on agricultural lands of the northern forest-steppe of Central Siberia (Krasnoyarsk forest-steppe). A refined version of the Regional Methodology is proposed, adapted to local hydrometeorological conditions and representing the formula of this model with an added correction factor \(K,\) taking into account the influence of the previous autumn moistening of soils and the intensity of water flow to the soil surface during snowmelt. Refinement and adaptation of the methodology allowed to increase the accuracy of the results of its application by an average of three times compared to the original type of the model, the average error decreased from 0.3 to 0.11. The refined version of the Regional methodology was tested in the course of the author’s research of snow-fall soil erosion in the Krasnoyarsk forest-steppe.
Thorium Concentrations in Terrestrial and Freshwater Organisms: A Review of the World Data
Authors: Fesenko S. V. , Emlyutina E. S.
Published: April 2024

An overview of data on thorium concentrations in terrestrial animals, as well as freshwater organisms is presented. Concentrations of 232Th in both animals and fish vary widely, reflecting environmental thorium concentrations. Thorium concentrations in the regions with a normal thorium background in animal tissues were in a range from 0.9 × 10–4 to 2.1 × 10–2 Bq/kg, and from 3.1 × 10–2 to 1.4 × 10–1 Bq/ kg in the areas with high thorium concentrations in the soil. Significantly higher values were observed in wild animals’ tissues. The highest 232Th concentrations were found to be in the skeleton, followed by lungs, kidneys, liver and finally muscles. It has been shown that thorium accumulation is higher in species occupying a higher position in the trophic chains. In areas with normal thorium background, the concentration of 232Th in fish can reach 1.0 × 10–1 Bq/kg (fresh mass), and in areas of high thorium background this value can be up to 100 times higher. The obtained results show the importance of study on the thorium transfer along the food chains and the need to consider observed regularities when assessing the consequences of radioactive contamination of the environment.
Dynamics of 137Cs Transfer Factors to Agricultural Products after the Chernobyl Accident: Grain, Potatoes, and Vegetables
Authors: Fesenko S. V. , Prudnikov P. V. , Emlyutina E. S. , Epifanova I. E. , Titov I. E. , Shubina O. A.
Published: April 2024

The results of the analysis of the 137Cs aggregated transfer factors (Tag) to crops (cereals, potatoes, and vegetables) produced in the districts of the Bryansk region affected after the Chernobyl accident are presented. The aggregated transfer factors in the year of the deposition as well as the dynamics of Tag in the subsequent years depended considerably on the fertility of soils subjected to contamination. The transfer factors of 137Cs to crops in the areas with higher fertility were 3–8 times lower (depending on the plant species) than in the areas with low fertility, and the most significant differences were observed for cereals. Decrease in Tag values was of irregular nature. The half-lives of 137Cs aggregated transfer factors for the period from 1986 to 2021 were calculated. It is shown that the first half-life values calculated for the period of intensive application of countermeasures (1987–1991) were from 0.7 to 1.4 years. The second half-lives varied from 7.3 to 17.3 years. In some areas, after a strong reduction in 137Cs concentrations in crops after 1994, there was a slow increase in 137Cs aggregated transfer factors, which can be explained by insufficient compensation for this decrease of geochemical binding of 137Cs in the soil. Later the dynamics of crop contamination was determined by multidirectional processes: i.e., increase in 137Cs transfer to plants and natural decrease of radionuclides bioavai-lability in soils under the influence of geochemical processes. In areas with intensive application of countermeasures, the reduction of Tag to crops was determined to a greater extent by the influence of agrochemical countermeasures. In the areas with limited application of countermeasures, the natural biogeochemical processes determining radionuclide binding by the soil-absorbing complex made the predominant contribution to the Tag reduction. Limitations of the approach based on the estimation of half-lives and the necessity of using the history of countermeasures implemented, as well as the soil fertility for prediction of the 137Cs intake by plants is noted.
Dosimetric Indicators of Damage to the Digestive Tract of Monogastric Animals by Incorporated Radioactive Particles
Authors: Shapovalov S. G. , Kozmin G. V.
Published: April 2024

The analysis of dosimetric parameters of internal irradiation and biological effects in monogastric animals (rats, guinea pigs, pigs) caused by orally received “hot” radioactive particles causing ulcerative necrotic lesions of the gastrointestinal tract is presented. Mathematical models of particle transport and formation of absorbed doses in the digestive tract have been developed. The features of the deep distribution of absorbed doses in the mucous membrane depending on the spectral characteristics of β-radiation of radionuclides that are part of silicate particles are given. It is shown that the main factors in the formation of ulcerative lesions of the digestive tract were the uneven distribution of particles in the contents and the concentration of particles in certain areas of the mucous membrane, followed by the formation of high local dose loads. A dosi-metric scale of extremely severe, severe, medium and mild acute radiation ulcerative gastroenterocolitis is proposed, which allows extrapolating the results of model experiments on scenarios of radioactive contamination of the environment by particles of various genesis. The results obtained can be taken into account in the tasks of radiation safety.
Dependence of the Translocation Frequency in Blood Lymphocytes on the Dose and Age at the Onset of Exposure in Residents of the Techa Riverside Settlements
Authors: Tolstykh E. I. , Vozilova A. V. , Degteva M. O. , Akleev A. V.
Published: April 2024

Evaluation of age effect on the frequency of radiation-induced translocations, registered using FISH in circulating T-lymphocytes in the long-term period after exposure, is both of theoretical and practical interest for the purposes of biodosimetry. The objective of our study was to analyze the dose dependence of the translocation frequency in the peripheral blood T-lymphocytes in donors of different age who were exposed in the Techa Riverside settlements (n = 197). In cytogenetic studies, whole chromosome painting probes were used to stain three pairs of chromosomes. A total of 104,721 genome equivalents (GE) were calculated and 2,540 translocations were found. For each donor, the individual absorbed doses in organs and tissues at the time of blood sampling were calculated using the Techa River Dosimetry System. In addition, doses to T-lymphocytes and their progenitors were calculated using the innovative modelling approach with due account of age related-dynamics of T-lymphocytes. The age dependence of the translocation frequency was associated particularly with these doses. The main sources of donor exposure were 89,90Sr, accumulating in bones and irradiating the bone marrow almost locally. To assess the parameters of the dose-effect relationship, linear regression model was used. After taking into account background values, the lowest frequency of translocations per 1000 GE per Gy was found in donors aged 0–5 years at the time of exposure (9.3 ± 1.3), which is statistically significantly lower than in children aged 6–18 years (15.3 ± 1.5), but not in adults (11.9 ± 2.9). The value for adults (18 years) was characterized by the maximum scatter, but was close to the values obtained in an international study of nuclear enterprise personnel after external exposure (11.6 ± 1.6). The values of the background translocation frequencies registered in various age groups correspond to the published data obtained in a joint international study on unexposed donors. We have also confirmed the absence of sex-effect on the frequency of translocations.
Monitoring of 137Cs, 90Sr and 40K in Gray Forest Soils and Plants of Reference Sites of the Vladimir Region
Authors: Utkin A. A.
Published: April 2024

The paper presents the results of radiation monitoring of gray forest soils of reference agricultural plots of the Vladimir region, conducted in 2011 and 2016. The study established background values of specific activities of the studied radionuclides in the soils of reference sites. According to the density of contamination of the arable horizon of soils 137Cs and 90Sr, the level of the ecological situation was determined, which made it possible to attribute the soils of all reference areas of the region to uncontaminated territories suitable without restrictions for agricultural use. The power of the exposure dose of gamma radiation of soils and the contribution of 40K and 137Cs to the formation of the gamma background of soils are established. Correlation ana-lysis determined the influence of individual physical and chemical properties of soils on the behavior and distribution of radionuclides in the soil and the relationship between the radionuclides themselves. Based on the values of the specific activity of 137Cs and 90Sr in plant products grown on the soils of reference sites in 2011 and 2016, rows of cultivated plants were constructed, with a decreasing ability to accumulate these radionuclides from the soil. All grown plant products for all types of crops fully met the sanitary and hygienic standards required to limit the content of 137Cs and 90Sr in plant feeds (green mass, straw and grain) and food products (apples). According to the transition coefficients, it was found that the process of transition of 90Sr from soil to plants of all kinds proceeded more intensively than the transition of 137Cs. The calculated coefficients of linear correlation between the values of the specific activity of 137Cs and 90Sr in soils and plants revealed the strength and nature of their dependencies.
Metabolic Correction of Cerebral Radiation Syndrome in Small and Large Animals
Authors: Vasin M. V. , Ilyin L. A. , Chernov Yu. N. , Ushakov I. B.
Published: April 2024

In experiments on mice, rats, guinea pigs and dogs, the effectiveness of metabolic correction of cerebral radiation syndrome with nicotinic and succinic acids and Esseentiale was evaluated. The animals were totally exposed to 5–8 and 16–20 MeV pulsed electron flux at doses of 85–110 or 500–570 Gy or to gamma irradiation at a dose of 100 Gy. The frequency and time of ataxia and convulsions, as well as the dynamics of animal death after radiation were recorded. Nicotinic and succinic acids (500 mg/kg each) and Esseenciale (20 mg/kg by nicotinamide) reduced the frequency and delayed the onset of ataxia and seizures equally in both small laboratory animals and dogs. In experiments on rats after exposure at a dose of 100 Gy under the influence of radiation and Essentiale, there was no significant change in animal cognitive function according to the decision-making test at the first presentation of a new deposit.
Three-Color FISH Method: A Comparison of Retrospective Cytogenetic Dose Estimations in Different Patients Undergoing Acute Emergency Irradiation
Authors: Lomonosova E. E. , Nugis V. Yu. , Kozlova M. G. , Nikitina V. A. , Galstyan I. A. , Snigiryova G. P.
Published: April 2024

This work presents the results of the use of three-color FISH-staining of chromosomes (DNA probes to 1, 4 and 12 pairs of chromosomes) for the cytogenetic study of peripheral blood lymphocyte cultures of four patients at different times after irradiation in various emergency situations. All victims had initial dose estimations: one by EPR signal in the tooth enamel (1.12 Gy) and three by the dicentric frequencies (1.9; 3.2 and 4.3 Gy). There was a strong significant linear correlation between the observed translocation frequencies and the initial dose estimations. Retrospective indication of the dose by translocation frequencies was carried out with the help of own dose-effect curve, the obtained on the basis of experiments with the irradiation of blood of healthy donors in vitro. At the same time, dose estimates in the long terms after irradiation in three of these patients with the greatest lesion were significantly lower than they were established earlier (1.26; 2.06 and 2.47 Gy). The coincidence of the initial and repeated results was observed only in one remaining patient.
Phenibut, Semax and GIZh-290 Modulate Cortical mGluII Receptors in an Attention Deficit Model in Mice
Authors: Sukhorukova N. A. , Vasileva E. V. , Kovalev G. I.
Published: April 2024

In our previous experiments, it was found that the nootropic drugs piracetam (200 mg/kg/day, intraperitoneally), pantogam (100), pantogam active (200), phenibut (70), semax (0.6), as well as a new derivative of racetam GIZh-290 (3) and the comparison drug atomoxetine (3.0) as a result of subchronic administration, attention stability to new objects is restored in the “closed enriched cross maze” test, showing selectivity of the effect in relation to a subpopulation of CD-1 mice with an initially low attention index (ED-Low). In this study, the effect of nootropics on metabotropic glutamate receptors (mGluRII) in the prefrontal cortex of these mice was studied using the receptor binding of a specific radioligand [G-3H]LY354740. It was found that the density (Bmax) of mGluII receptors in the brains of subpopulation with the ED-Low phenotype was 11–25% lower than in subpopulation with the ED-High phenotype. None of the drugs had an effect on these receptors in the subpopulation with the ED-High phenotype, whereas phenibut, semax and GIZh-290 showed efficacy with respect to the ED-Low phenotype, increasing Bmax values by 60, 19 and 22%, respectively. Thus, it was shown for the first time that mGluRII are involved in the pathogenesis of attention impairment, and the ability of phenibut, semax and GIZh-290 (2,6-dimethylanilide (2-oxo-4-phenylpyrrolidine-1-yl) acetate to selectively normalize the reduced density of these receptors indicates the prospects of their use in as a drugs for the treatment of attention deficit disorder.
Common and Specific Effects of Selank, Noopept, and Semax to Glycine Site of the NMDA Receptor in BALB/c and C57Bl/6 Mice Brain
Authors: Kovalev G. I. , Vasileva E. V. , Abdullina A. A.
Published: April 2024

The effects of the nootropic peptides selank (300 mg/kg), noopept (1 mg/kg), and semax (0.6 mg/kg) after subchronic intraperitoneal (i.p.) and intranasal (i.n.) administration on the binding of [3H]-MDL105,51 to NMDA glycine site in BALB/c and C57Bl/6 mice brain were examined. It was found that in C57Bl/6 mice in comparison with BALB/c the number of glycine binding sites (Bmax) at baseline was 15% higher in the cortex and 47% lower in the hippocampus. In the cortex i.n. administration of selank, noopept, and semax resulted in 18, 19, and 66% decrease in the number of glycine binding sites in BALB/c mice, and in 53, 49, and 66% in C57Bl/6 mice, respectively. In the hippocampus i.n. administration of selank, noopept, and semax resulted in 15, 63, and 95% increase in the number of glycine binding sites in BALB/c mice, respectively, while in C57Bl/6 mice all three peptides were not effective. In the cortex i.p. administration of selank and semax decreased glycine binding sites by 24 and 40% in the cortex and by 11 and 19% in the hippocampus in BALB/c mice, while in C57Bl/6 mice the reduction was 15% and 47% in the cortex and 45 and 24% in the hippocampus, respectively. Noopept did not affect the binding. These patterns observed in the cortex after i.n. and i.p. administration appear to be common to the both mice strains suggesting an engagement of the cortical NMDA glycine site in action(s) that underlie some common pharmacological effects of the selected peptides. Whereas the specific effect of selank, noopept, and semax after i.n. administration in the BALB/c hippocampi may be associated with the mechanisms of nootropic and anxiolytic activities of these peptides manifested in that mice strain.
Differences in Changes in the Glutamate/GABA System Activity in the Rat Retina during Aging and the Development of Retinopathy at Nighttime and Daytime
Authors: Telegina D. V. , Antonenko A. K. , Kolosova N. G.
Published: April 2024

Age is a leading risk factor for the development of age-related macular degeneration (AMD), which is the cause of vision loss in elderly. There are no effective methods of therapy for this complex neurodegenerative disease due to the incomplete knowledge of its etiology and pathogenesis. It is assumed that development of aging imbalance of neurotransmitter systems (glutamate, GABA) in the retina, their desynchronosis, may be a precondition for the development progression of AMD. Information about their state in the retina during aging, and especially development of AMD, is extremely limited. We previously assessed age-related changes in the daytime glutamate/GABA system in the retinas of Wistar and senescence-accelerated OXYS rats that develop AMD-like pathology. Here, we evaluated aging changes in the synthesis and degradation enzymes, receptor subunits, and transporters of these neurotransmitters at nighttime and compared them with detected earlier in the daytime. Differences in age-related changes in the expression of the components of the glutamate and GABAergic systems at night and daytime were revealed during “healthy” aging in Wistar rats and during premature aging in OXYS rats. This may be due to disruption of the circadian rhythm. It is established that the progression of AMD-like retinopathy in OXYS rats occurs against the background of changes in the glutamatergic system at the nighttime (increased of glutamine synthetase, NMDARr1 level and decreased GLAST level), which facilitate the retinal neurodegenerative changes. Pronounced changes in the GABAergic system, which could make a significant contribution to the development of the pathological process were not identified.
Induction of Cholinergic Phenotype in Mouse Neuroblastoma Cells Using Nerve Growth Factor
Authors: Koryagina A. A. , Nedogreeva O. A. , Buyanova A. A. , Spivak Yu. S. , Bolshakov A. P. , Gulyaeva N. V. , Stepanichev M. Yu.
Published: April 2024

Nerve growth factor (NGF) is a key factor of neuronal differentiation. NGF plays an important role in growth and differentiation of sensory and sympathetic neurons in the peripheral nervous system. In the mature brain, NGF is important for the maintenance of a cholinergic neuronal phenotype. Here, we studied whether NGF is sufficient to induce cholinergic phenotype in murine neuroblastoma cells, which are often used to model various physiological and pathological conditions. We detected expression of both TrkA and p75NGFR of NGF receptors in NB41A3 and Neuro2a neuroblastoma cells, two the most popular cell lines widely used to study the properties of cholinergic neurons in vitro. Treatment of both types of cell cultures with NGF did not induce in contrast to 8-Br-cAMP, which induced differentiation of Neuro2a cells with formation neuron-like morphology. Furthermore, we did not reveal the markers of cholinergic phenotype, such as ChAT or VAChT mRNA or protein in these cells, after NGF treatment. Thus, NB41A3 and Neuro2a cells cannot be used as an in vitro model of cholinergic cells because they do not differentiate and/or exhibit cholinergic phenotype in response to NGF stimulation.
Molecular Dynamic Simulation of Silicon Irradiation with 2–8 keV Buckminsterfullerene C60 Ions
Authors: Karasev K. P. , Strizhkin D. A. , Titov A. I. , Karaseov P. A.
Published: April 2024

The processes taking place on the (100)Si surface irradiated by 2–8 keV buckminsterfullerene C60 ions at temperatures ranging from 0 to 700 K are examined using molecular dynamics computer simulations. Tersoff-ZBL and Airebo potentials are used to describe pairwise interactions, inelastic energy loss is taken into account for fast atoms. The results show that crystal temperature has no influence on the collision cascade development, but affect its thermalisation and crater formation on the surface. With the C60 ion energy increase, carbon atoms penetrate deeper into the target, both crater volume and size of the rim around it enlarges. Temperature increase to 700 K leads to more effective crater and rim formation comparing to 0 and 300 K cases. We propose possible explanation of the revealed phenomenon.
Investigation of the Possibilities of Analysis of the Vesicular Structure of PTNS-Based Nanodrugs Using the Small-Angle Neutron Scattering Data
Authors: Kiselev M. A. , Zemlyanaya E. V. , Zhabitskaya E. I. , Bashashin M.V. , Ivankov O. I.
Published: April 2024

The small-angle neutron scattering spectra of polydispersed populations of unilamellar vesicles were analyzed depending on the concentration of maltose in a heavy water solution. The spectra were measured on a YuMO small-angle spectrometer at the Dzhelepov Laboratory of Neutron Physics of the Joint Institute for Nuclear Research (Dubna). Two types of nanosystems developed at the Orekhovich Institute of Biomedical Chemistry. This is a phospholipid transport nanosystem, as well as the Indolip nanodrug based on a phospholipid transport nanosystem. The possibilities of obtaining information on the vesicular structure of nanodrugs based on a phospholipid transport nanosystem using the small-angle neutron scattering data are discussed. Computer analysis of small-angle scattering spectra is based on the application of the separated form factors method. The values of the basic structural parameters of these vesicular systems (the average radius of vesicles in the population, the thickness of the bilayer across the membrane, the polydispersity coefficient, etc.) obtained on this basis are generally consistent with the corresponding results of similar processing of small-angle X-ray scattering data. However, compared with small-angle X-ray scattering, the method of small-angle neutron scattering turns out to be less sensitive to the detailed consideration of structural features of the vesicle shell bilayer.
Features of the Electronic and Local Atomic Structures of Erbium Complexes of Tetraphenylporfyrin: Analysis of the Data Photoelectron Spectroscopy and X-Ray Absorption Spectroscopy
Authors: Mozhchil R. N. , Ionov A. M. , Bozhko S. I. , Rumyantseva V. D. , Menushenkov A. P. , Trigub A. L.
Published: April 2024

The features of the electronic and local atomic structure of erbium metalloporphyrins Er(acac)TPPBr8, Er(acac)TPP and precursor tetraphenylporphyrins (TPP and TPPBr8) have been studied by X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. Using photoelectron spectroscopy, the structure parameters of the Er4d, N1s, C1s, O1s, Br3d core levels and the valence band have been determined. The nature of the change in the electronic structure of tetraphenylporphyrins upon the introduction of the central erbium atom has been established – a uniform redistribution of the electron density between the nitrogen atoms of the pyrrole and aza groups. From the analysis of the X-ray absorption spectra, the effect of bromine addition in the meso-position of the macrocycle on the parameters of the local atomic structure of the erbium porphyrin complex has been established, and the integer trivalent state of the metal (Er3+) in rare-earth metalloporphyrins has been confirmed.
Sliding Interaction of Accelerated Proton Beams with Curved Dielectric Surface
Authors: Zhilyakov L. A. , Kulikauskas V. S.
Published: April 2024

The work is aimed at continuing the study of the “guiding” effect in various aspects. Due to this effect, it is possible to organize contactless transmission of beams of accelerated charged particles along a dielectric surface. In particular, when interacting with a dielectric plate, the guiding effect ensures the transmission of proton beams without ionization energy losses. An experiment was carried out on the sliding interaction of accelerated proton beams with a curved dielectric wall, in which proton beams were pressed against the wall surface by an external electric field. For beams that experienced such an interaction, the energy spectrum was measured. Comparison of the energy spectra of the initial beam and the beam that passed in a sliding mode along a curved dielectric wall showed that in this interaction, as well as when sliding along a flat dielectric wall, proton beams do not experience ionization energy losses.
The Use of Crystals with an Asymmetric Reflection Geometry to Measure the Parameters of Electron Beams
Authors: Berdnichenko A. V. , Vnukov I. E. , Goponov Y. A. , Takabayashi Y.
Published: April 2024

The prospects of using crystals with asymmetric reflection geometry to determine the transverse size of relativistic electron beams based on the results of measurements of angular distributions of their radiation in a thin crystal for two distances between it and a coordinate detector are discussed. An experimental test of this technique was carried out using an imaging plate as a two-dimensional position-sensitive detector. Measurements were made for the electron energy of 255 MeV and reflection (220) in a silicon crystal with a thickness of 20 microns and a pixel size of 35 × 35 µm2. The distances between the crystal and the detector were 0.5 and 1 m. The obtained values of the horizontal and vertical beam sizes \({{\sigma }_{x}} = 0.32 \pm 0.02\,\,~{\text{mm}}\) and \({{\sigma }_{y}} = 1.35 \pm 0.02~\,\,{\text{mm}}\) are in satisfactory agreement with the measurement results for optical transition radiation. The possibility of characterizing X-ray plates by comparing the measured and calculated PXR angular distributions for several reflecting planes of crystals with an asymmetric reflection geometry and an asymmetry parameter ε less than unity is discussed.
Modeling of the Potential Energy of Interaction of Two Atoms by Solving a System of Nonlinear Equations
Authors: Koshcheev V. P. , Shtanov Yu. N.
Published: April 2024

In the first order of perturbation theory, it is shown that the potential energy of interaction between two atoms can be calculated by solving a system of nonlinear equations. The system of equations has been constructed both with and without regard to the Pauli principle, and the atomic form factor has been calculated using wave functions that approximate the solution of the Hartree–Fock equation for isolated nitrogen atoms. The graph of the potential energy of the interaction of two nitrogen atoms satisfactorily agrees with the known results when the Pauli principle is taken into account. It is shown that without taking into account the Pauli principle and collective oscillations of the electrons of atoms, it is not possible to obtain agreement with experiment. It is shown that the total energy of a diatomic molecule is a functional that depends on the electron density of isolated atoms.
Investigation of the Dependence of the Yield of Neutrons and Protons of the DD Reaction from Ti and CVD Diamond on the Target Rotation Angle
Authors: Negodaev M. A. , Rusetskii A. S. , Shpakov K. V. , Popovich A. F. , Tsekhosh V. I. , Amosov V. N. , Rodionov N. B. , Artemev K. K. , Meshaninov S. A. , Skopintsev D. A.
Published: April 2024

At the HELIS ion accelerator, the dependence of the yield of nuclear DD reaction products (neutrons and protons) on the angle of rotation of a Ti and CVD diamond target relative to the axis of the D+ ion beam at energies E ≤ 35 keV was studied. Neutron detection was carried out by two independent methods: proportional counters filled with 3He and a scintillation detector with a stilbene crystal. Protons were detected using a diamond detector. The detectors were located on the side and behind the target. The CVD diamond target had a polycrystalline structure and texture with (100) grain orientation. The crystal structure of the titanium target was homogeneous and isotropic. The measurements showed the dependence of the neutron flux recorded by the detectors located on the side and behind the target on the orientation of the target made of textured CVD diamond in the deuterium ion beam at energies of 25 and 30 keV. The proton yield from the CVD diamond target showed a dependence on the target rotation angle at an energy of 25 keV. For the Ti target, no such effects were observed. The orientational dependence in the yield of neutrons and protons from textured diamond is explained by the effect of channeling deuterium ions in its structure.
Structural and Phase Changes in Concentrated Solid Solutions of the V–Nb–Ta–Ti System Irradiated with Helium Ions
Authors: Uglov V. V. , Zlotski S. V. , Belov M. M. , Ryskulov A. E. , Ke Jin , Ivanov I. A. , Kurakhmedov A. E. , Mustafin D. A. , Sapar A. D. , Bikhert Y. V.
Published: April 2024

The aim of this work is to study the effect of irradiation with low-energy helium ions with a fluence 2 × 1017 cm–2 and an energy of 40 keV on the structural-phase state of multicomponent solid solutions based on V–Nb–Ta–Ti. These studies are aimed at obtaining new data on the radiation resistance of multicomponent solid solutions, which have great potential for use as structural materials for new generation reactors. As a result of the work carried out by scanning electron microscopy and X-ray diffraction analysis, it was found that all alloys of the system belong to equiatomic single-phase solid solutions and in the initial state, have a homogeneous distribution of elements on the surface and have compressive micro- and macro-stresses. The conducted studies have shown that irradiation with helium ions of alloys of the V–Nb–Ta–Ti system does not lead to the decay of the solid solution and disturbance of the equiatomicity and uniformity of the distribution of elements on the surface. Irradiation with helium ions does not lead to a significant change in the level of micro- and macro-stresses for VNb and VNbTa systems, while for VNbTaTi alloy there is an increase in compressive stresses, which may be due to the segregation of elements and the accumulation of helium-vacancy clusters.
Integrated Study of Solid Uranium-Containing Materials for the Purposes of Nuclear Forensics
Authors: Zhukov A. V. , Kuchkin A. V. , Zhizhin K. D. , Babenko A. S. , Komarov Y. A. , Stebelkov V. A.
Published: April 2024

An optimal algorithm is presented for studying unknown samples of solid uranium-containing materials and obtaining the maximum possible information about their similarities and differences, about their production technology and a possible source of origin for the purposes of nuclear forensics. The results of the study of physical characteristics, isotopic, elemental and phase composition, morphology and other parameters of material samples obtained by the Laboratory in the course of participation in the international experiment CMX5 (Collaborative Materials Exercise 5), organized by the Nuclear Forensics International Technical Working Group, are analyzed.
Study of Surface Morphology of Microfluidic Chip Channels via X-Ray Tomography and Scanning Electron Microscopy
Authors: Chapek S. V. , Pankin I. A. , Khodakova D. V. , Guda A. A. , Goncharova A. S. , Soldatov A. V.
Published: April 2024

The visualization of microfluidic chips was considered to study morphology of microfluidic channel surface and estimate the quality of 3D printing technology based on digital light processing. The visualization was performed by X-ray microtomography using different iodine-based contrast agents and by scanning electron microscopy. It was shown that X-ray microtomography visualization made it possible to control the quality of device printing relative to geometrical parameters of the models specified at the prototyping stage, as well as to visualize a 3D model of microfluidic channels and surface morphology. The spatial resolution of scanning electron microscopy exceeds the print pixel size and makes it possible to clarify the presence of local defects caused by uneven solidification of the resin during sample washing.
Features of the Effect of a High-Power Ion Beam of Nanosecond Duration on Polyethylene Terephthalate
Authors: Kovivchak V. S.
Published: April 2024

The features of formation of surface morphology of polyethylene terephthalate under the influence of high-power ion beam of nanosecond duration have been investigated. It has been established that at a single exposure of such a beam to polyethylene terephthalate, as well as for the majority of other polymers, pores are formed in a near-surface layer, however their quantity is much less. Significant differences begin to appear when the polymer is repeatedly irradiated with a high-power ion beam. For most polymers this leads to an increase in surface porosity and partial local destruction of the near-surface layer. Under such irradiation conditions, various spatial structures are formed on the polyethylene terephthalate surface, the type and sizes of which depend on the number of irradiation pulses. X-ray microanalysis of the near-surface layer showed a significant (1.4 times) decrease of oxygen content after ion irradiation. Irradiation of polyethylene terephthalate by high-power ion beam does not result in the formation of a thin carbon layer on its surface. The possible reasons of formation of such surface morphology under the action of high-power ion beam on polyethylene terephthalate have been considered.