bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Influence of Magnetic Turbulence on the Spectra of Gamma-Ray Burst Afterglows
Authors: Uvarov Yu. A. , Bykov A. M.
Published: April 2024

Gamma-ray bursts (GRBs) are the phenomena of rapid energy release of enormous power associated with the collapse ormerging of stars. As a result of internal processes, populations of nonthermal accelerated particles radiating in a wide energy range are formed in them. A number of observations have shown that photons with energies up to tens of TeV are detected from some GRBs. However, due to the great energy losses of radiating particles, the explanation of this high-energy radiation in terms of standard radiation mechanisms runs into great difficulties. In this paper, based on the model of adiabatic expansion for the GRB afterglow phase, we investigate the influence of magnetic inhomogeneities on the spectrawithin the electron and proton synchrotron radiation mechanism by taking into account the Compton scattering of synchrotron photons. We show that the magnetic inhomogeneity effect can increase themaximum energies of the synchrotron radiation from electrons and protons severalfold without affecting the maximum energies of the Compton photons being produced in the Klein–Nishina regime.
SRG/ART-XC Galactic Plane Survey near Galactic Longitude L 20◦ :
Catalog of Sources
Authors: Pavlinsky M. N. , Tkachenko A. Yu. , Shtykovsky A. E. , Karasev D. I. , Semena A. N. , Mereminskiy I. A. , Lutovinov A. А. , Burenin R. A. , Krivonos R. A. , Sazonov S. Yu. , Arefiev V. A. , Buntov M. V. , Lapshov I. Yu. , Левин V. V.
Published: April 2024

We present a catalog of sources detected by theMikhail Pavlinsky ART-XC telescope onboardthe SRG space observatory during the observations of the Galactic plane region near a longitude l 20◦(L20 field) in October 2019. The L20 field was observed four times in the scanning mode, which provideda uniform coverage of the sky region with a total area of 24 sq. deg with a median sensitivity of 8 ×10−13 erg s−1 cm−2 (at 50% detection completeness) in the 4–12 keV energy band. As a result, we havedetected 29 X-ray sources at a statistically significant level, 11 of which have not been detected previouslyby other X-ray observatories. Preliminary estimates show that four of themcan presumably be extragalacticin nature. We also show that the source SRGA J183220.1−103508 (CXOGSG J183220.8−103510) ismost likely a galaxy cluster containing a bright radio galaxy at redshift z 0.121.
Origin of the Near-Surface Rotational Shear Layer of the Sun
Authors: Kitchatinov L. L.
Published: April 2024

Helioseismology has revealed an increase in the rotation rate with depth in a thin (∼30 Mm)near-surface layer. The normalized rotational shear in this layer does not depend on latitude. This rotationalstate is shown to be a consequence of the short characteristic time of near-surface convection comparedto the rotation period and radial anisotropy of convective turbulence. Analytical calculations within meanfieldhydrodynamics reproduce the observed normalized rotational shear and are consistent with numericalexperiments on radiative hydrodynamics of solar convection. The near-surface shear layer is the source ofglobal meridional flow important for the solar dynamo.
Neutrino Emission of Neutron-Star Superbursts
Authors: Kaminker A. D. , Potekhin A. Yu. , Yakovlev D. G.
Published: April 2024

Superbursts of neutron stars are rare but powerful events explained by the explosive burningof carbon in the deep layers of the outer envelope of the star. In this paper we perform a simulation ofsuperbursts and propose a simple method for describing the neutrino stage of their cooling, as well as amethod for describing the evolution of the burst energy on a scale of several months. We note a universalrelation for the temperature distribution in the burnt layer at its neutrino cooling stage, as well as theunification of bolometric light curves and neutrino heat loss rates for deep and powerful bursts. We pointout the possibility of long-term retention of the burst energy in the star’s envelope. The results can be usefulfor interpretation of superburst observations.
Angles between the Magnetic Moment and the Rotation Axis
in Radio Pulsars with Hard Emission
Authors: Timirkeeva M. A. , Malov I. F.
Published: April 2024

We have performed a comparative analysis of the angles β between the rotation axis and themagnetic moment in three groups of radio pulsars: sources inwhich only radio emission is observed, pulsarswith detected X-ray emission, and radio-loud gamma-ray pulsars. For this purpose, we have calculated thevalues of the angle β separately for objects from each group by two differentmethods. It has turned out thatin pulsars with hard emission themean values of this angle (28.2◦ and 28.8◦) are greater than those for quietradio pulsars (12.9◦). However, using the Kolmogorov–Smirnov test, we have shown that the revealeddifference is insignificant with a high probability. Consequently, the structures of the magnetospheres in thethree groups of pulsars considered do not differ greatly, while their difference is attributable to the magneticfield strength on the light cylinder that switches on the hard nonthermal emission mechanism in pulsarswith detected X-ray and/or gamma-ray emission but is not enough for this in quiet radio pulsars in thehard ranges.
Nucleolus Organizer Region Functioning in Chicken Growing Oocytes: A Revision of the Existing Views
Authors: Davidian A. G. , Koshel E. I. , Galkina S. A. , Saifitdinova A. F. , Gaginskaya E. R.
Published: April 2024

It is believed that the nucleolus organizer region (NOR) in the ovary of adult birds is inactivated at all stages of oocyte growth. However, in the ovary of juvenile chicken (Gallus g. domesticus) one or two nucleoli were observed in 50% of early diplotene oocytes. These nucleoli were functioning up to the lampbrush stage. It was assumed that diplotene oocytes with inactivated NOR are stored as a pool for development in the ovary of adult hens. Such a contradiction in the NOR functional activity in the oocytes of juvenile and adult hens required special studies. Here we represent new results of a comparative study of the nucleoli in oocytes of juvenile and adult hens. We show for the first time that in the oocytes of laying hens the nucleolus appears at the early diplotene stage and the pre-rRNA synthesis continues up to the lampbrush stage. At the lampbrush stage, the NOR is getting inactivated. The nucleolus disintegrates into large fragments containing both pre-rRNA and fibrillarin. Then these larger fragments break down into small granules that do not contain pre-rRNA but contain fibrillarin. The results resolve the above contradiction and demonstrate a similar pattern of NOR functioning in oocytes of adult and juvenile birds.
Creation of Induced Pluripotent Stem Cells ICGi044-B and ICGi044-C Using Reprogramming of Peripheral Blood Mononuclear Cells of a Patient with Parkinson’s Disease Associated with с.1492T>G Mutation in the GLUD2 Gene
Authors: Sorogina D. A. , Grigor’eva E. V. , Malakhova A. A. , Pavlova S. V. , Medvedev S. P. , Vyatkin Y. V. , Khabarova E. A. , Rzaev J. A. , Zakian S. M.
Published: April 2024

Parkinson’s disease is a multifactorial disease; both genetic predisposition (5% of all cases), environmental factors and age-related changes in the brain and other body systems contribute to its etiology. For the diagnosis and study of the pathology of the development of the disease, it is important to search for new polymorphisms associated with hereditary forms of the disease. We analyzed the clinical exome of a 55-year-old patient with Parkinson’s disease and identified a single nucleotide polymorphism in the GLUD2 gene (c.1492TG). This genetic variant is pathogenic according to the ClinVar database, but the mechanism of pathogenesis is still poorly understood. In addition, there are currently no relevant models based on human cells, which is of great interest. We generated induced pluripotent stem cells (iPSCs) from patient peripheral blood mononuclear cells using non-integrating episomal vectors expressing OCT4, KLF4, L‑MYC, SOX2, LIN28, and p53 shRNA. The obtained iPSC lines (ICGi044-B and ICGi044-C) demonstrate typical ESC-like morphology, normal karyotype (46,XY), express pluripotency markers (OCT4, SOX2, NANOG, SSEA4, TRA-1-60) and are able to give derivatives of three germ layers. The iPSC lines ICGi044-B and ICGi044-C, as well as their neural derivatives, represent an unique in vitro cell model for studying the pathogenetic mechanisms of the development of Parkinson’s disease associated with the c.1492TG mutation in the GLUD2 gene.
Analysis of the Ovarian Marker Genes Expression Revealed the Antagonistic Effects of Serotonin and Androstenedione on the Functional State of Mouse Granulosa Cells in Primary Culture
Authors: Alyoshina N. M. , Rousanova V. R. , Malchenko L. A. , Khramova Yu. V. , Nikishina Yu. O. , Konduktorova V. V. , Evstifeeva A. Y. , Nikishin D. A.
Published: April 2024

Primary culture of granulosa cells is a prerequisite for a complete study of the normal functioning of the ovary and its pathologies. In this work, we selected the optimal protocol for obtaining a primary culture of mouse granulosa cells in the most functionally active state and revealed the effects of androstenedione and serotonin on the expression of ovarian markers that reflect the functional status of granulosa cells. The morpho-functional analysis of the ovary after PMSG stimulation revealed that 48 hours after PMSG stimulation is the optimal time for obtaining granulosa cells in the most active functional state. Using the set of 14 ovarian functional state marker genes we reveal that androstenedione inhibits cumulus and immature granulosa markers but stimulates genes characteristic of the mature state of granulosa. At the same time, granulosa cells express serotonergic receptors and transporter SERT. The ovarian marker genes expression analysis revealed that serotonin affects the expression of genes characterizing the differentiation of granulosa cells towards cumulus cells. Summarizing, we can conclude that serotonin and androstenedione have an antagonistic effect on the functional state of mouse granulosa cells in primary culture in vitro.
Ectopic Expression of Human, Mouse, and Fruit Fly Aryl Hydrocarbon Receptor in Drosophila melanogaster Tissues
Authors: Baranova D. Yu. , Akishina A. A. , Cherezov R. O. , Kulikova D. A. , Mertsalov I. B. , Simonova O. B. , Vorontsova J. E.
Published: April 2024

The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor and its target genes play a fundamental role in detoxification, regulation of developmental processes, maintenance of homeostasis, as well as in the occurrence of oncological and autoimmune diseases and drug metabolism. The high conservatism of vertebrate AHR allowed us to study its functions in vivo using transformed Drosophila melanogaster fruit flies with human or mouse AHR gene and compare the ectopic effect of their expression with the expression of spineless gene, Drosophila AHR homologue. This work demonstrates for the first time that vertebrate AHR exhibits its functional activity in Drosophila embryogenesis, in leg imaginal discs and in somatic cells of female reproductive system in the absence of exogenous ligands.
Mechanisms of Growth Promotional and Protective Effects of Endophytic PGP-Bacteria in Wheat Plants Under the Impact of Drought (Review)
Authors: Lastochkina О. V. , Allagulova Ch. R.
Published: April 2024

The review is devoted to the analysis and systematization of modern data on the participation of endophytic plant growth-promoting (PGP) bacteria in the regulation of growth, development, yield formation, and stress resistance of cultivated plants, mainly spring wheat as the main bread crop. Presently known data on the interaction of plants with PGP-bacteria under normal and drought conditions are described. Particular attention is paid to the molecular mechanisms of regulation of plant metabolism by PGP-bacteria, as well as their role in reducing the negative effects of drought, achieved by modulating various processes in plants, for example, improving the supply of moisture and mineral nutrients, and activating the antioxidant and osmoprotective plant systems. A key role in the adaptation and resistance/tolerance of plants caused by PGP-bacteria are played by their ability to produce various metabolites with the properties of biologically active substances, including substances with antimicrobial and hormonal activity, enzymes and other compounds. Information about the endophytic microbiome of wheat is given, the elucidation of the role and functions of which in plant stress response and adaptation is necessary for the development of effective, safe strategies for their practical application in order to maximize the adaptation and productive potential of wheat under changing environmental conditions.
Development of Fluorescence Polarization Immunoassay of Sulfathiazol and its Application for Honey Testing
Authors: Nesterenko I. S. , Hendrickson O. D. , Smirnova N. I. , Eremin S. A. , Sotnikov D. V.
Published: April 2024

A fluorescence polarization immunoassay has been developed for the detection of the antibacterial sulfathiazole. The latter belongs to the sulfonamide class of antibacterial, which is used in beekeeping for the prevention and treatment of infectious diseases of bees. The assay conditions, which ensure the achievement of high analytical characteristics, are determined. The duration of the analysis is 5 min; the limit of sulfathiazole detection is 3 ng/mL. A study of the assay selectivity concerning other sulfonamides demonstrated the high specificity only towards sulfathiazole. The optimal method of sample preparation before the control honey contamination was proposed. The effectiveness of the developed analysis for the detection of sulfathiazole in honey samples was confirmed. The developed fluorescent polarization immunoassay is a rapid and efficient analytical system for rapid and sensitive control of honey quality and safety.
Extracellular Vesicles of Bacteria Mediate Intercellular Communication: Practical Applications and Biosafety (Review)
Authors: Chernov V. M. , Mouzykantov A. A. , Baranova N. B. , Chernova O. A.
Published: April 2024

Extracellular vesicles, secreted by bacterial cells, are the focus of close attention of researchers. They are enriched with bioactive molecules, mediate the intercellular communication of micro- and macroorganisms, participate in the adaptation of bacteria to stressful conditions, reprogramming target cells, modulating immunoreactivity in higher organisms, changing the structure of microbial communities and ecosystems. The unique properties of bacterial extracellular vesicles (BEVs) open up broad prospects for their practical application – in clinical medicine, agriculture, biotechnology and ecology as diagnostic markers, vaccines, new biological products and means of their delivery. However, to implement the practical applications, a number of problems need to be solved. This review focuses on the ambiguous role of BEVs in the regulation of living systems, the problem of assessing the safety of BEVs and approaches to its solution related to innovative technologies.
Formation of Various Antimicrobial Peptide Emericellipsin Isoforms in Emericellopsis alkalina under Different Cultivation Conditions
Authors: Kuvarina A. E. , Sukonnikov M. A. , Rogozhin E. A. , Serebryakova M. V. , Timofeeva A. V. , Georgieva M. L. , Sadykova V. S.
Published: April 2024

A microbiological screening of the target component of emericellipsin A of the Emericellopsis alkalina E101 strain was carried out in various biotechnological systems at various pH. The content of emericellipsin A was quantified under these conditions.It has been established that the new approved membrane-liquid cultivation method at pH 10 contributes to an increase in the yield of the main component of emericellipsin A. It was shown that the new method of cultivating the strain E. alkalina E101 also promotes the synthesis of various isoforms of the main component of emericellipsin A. Some comparative analysis of them was carried out.
Protein Antioxidant Complex of Water Extract of Larvae of Black Beetles Ulomoides dermestoides
Authors: Ushakova N. A. , Tikhonova O. V. , Ambaryan A. V. , Bastrakov A. I. , Dontsov A. E.
Published: April 2024

An aqueous extract from the larvae of black beetles Ulomoides dermestoides grown under controlled conditions was obtained and its proteomic analysis based on one-dimensional electrophoretic separation of proteins, their trypsinolysis in a gel and subsequent chromatography-mass spectrometry was performed. Protein identification was performed using MaxQuant v.1.6.3.4 software. The Uniprot database was used to identify proteins by homology. Catalase activity was determined spectrophotometrically by hydrogen peroxide concentration decrease. Antioxidant activity was evaluated by luminol chemiluminescence quenching. The extract contained proteins that can determine the biological activity of the extract: universal regulators of cellular processes calmodulin (62%), cytochrome c-2 (13.5%), nucleoside diphosphate kinase (11.1%), the enzymatic antioxidants superoxide dismutase, catalase, glutathione S-transferase, peroxiredoxin, glutathione synthetase as well as thioredoxin, 70 and 60 kDa heat shock proteins, chitinase complex (13.4% in total). Catalase activity was 6.3 ± 1.1 µmol H2O2/min/mg protein; antioxidant activity of 1 mg protein per ml extract was equivalent to 1.36 ± 0.3 mM trolox. The prospects for practical use of the extract as a natural antioxidant complex were noted.
Production of Soluble Human Gamma Interferon in the Escherichia coli Expression System with a Decrease in Cultivation Temperature
Authors: Volosnikova E. A. , Esina T. I. , Shcherbakov D. N. , Volkova N. V. , Gogina Ya. S. , Tereshchenko T. A. , Danilenko E. D.
Published: April 2024

A recombinant strain producing human gamma interferon (IFN-γ) E. coli BL 21/pET-IFN-γ was constructed, providing a high level of its expression. A method has been developed for obtaining a soluble form of recombinant IFN-γ, consisting of the processes of producing a biomass of a producer strain containing a target protein in an amount of 32–37% of the total content of cellular proteins, protein isolation and purification. The purification process included the stages of disintegration, clarification of the cell lysate, chromatographic purification and dialysis. The developed method makes it possible to obtain from 1 g of wet biomass up to 5 mg of the drug with a purity of at least 95% and high specific (antiviral) activity.
Naringenin Modulates Adenylate Cyclase Activity in Planktonic Culture and Biofilm Rhizobium leguminоsarum bv. viciae
Authors: Goncharova A. M. , Lomovatskaya L. A. , Romanenko A. S.
Published: April 2024

The effect of naringenin on the growth of plankton culture, biofilm density, and activity of the transmembrane form of adenylate cyclase in the cells of Rhizobium leguminosarum bv. viciae has been studied. The studies performed showed that naringenin had practically no effect on the growth of the planktonic culture of these bacteria, while the density of biofilms decreased as the concentration of naringenin increased. It was shown that naringenin activated the transmembrane form of adenylate cyclase in planktonic culture cells and biofilms. Moreover, in the planktonic culture, this effect was more significanted. It is assumed that the activation of rhizobial transmembrane adenylate cyclase by naringenin is carried out using a receptor mechanism.
Comparison of HydSl Hydrogenase of Thiocapsa bogorovii and its Modification with Truncated C-terminus of HydS
Authors: Starodubov A. S. , Khasimov M. K. , Khusnutdinova A. N. , Zorin N. A. , Tsygankov A. A.
Published: April 2024

Native HydSL hydrogenase of Thiocapsa bogorovii and its modification with truncated C-terminus of HydS (delta54HydS) were shown to be similar in specific activity, thermostability and temperature dependence of activity. It supports the suggestion that C-terminus of HydS does not participate in stabilization of the enzyme structure. Ag+ ions irreversibly inactivated both hydrogenases but delta54HydS was more sensitive to this inhibitor. In the presence of Ag+ the absorption peak at 410 nm was bleached indicating the destruction of FeS clusters. Protein globule was also destructed by Ag+. Prolonged incubation of hydrogenase with Ag+ ions led to disappearance of CO and CN peaks in IR spectra indicating NiFe center impairment. Data suggest that the first target of Ag+ ions is distal FeS cluster, and C-terminus of HydS interacts with Ag+ decreasing local ion concentration near the distal FeS cluster.
Properties of Extracellular Proteinase – Activator of Blood Plasma Prekallikrein Produced by Micromycetes Aspergillus terreus 2
Authors: Zvonareva E. S. , Osmolovskiy A. A. , Baranova N. A. , Kotova I. B. , Kreyer V. G.
Published: April 2024

The extracellular proteinase – activator of human plasma prekallikrein was isolated from the culture fluid of the micromycete A. terreus 2, and their physicochemical, kinetic and biochemical properties were studied. It has been established that A. terreus 2 extracellular proteinase is a glycosylated serine proteinase with an isoelectric point of 4.6, molecular weight about 37 kDa and the optimum activity at pH 10.0 and a temperature of 37°C. In a number of properties, this proteinase is similar to proteinase – activator of protein C, which is produced by the micromycete A. ochraceus L-1.
Effect of Peroxynitrite and tert-Butyl Hydroperoxide on Thiol Ligands of Dinitrosyl Iron Complexes
Authors: Pugachenko I. S. , Nasybullina E. I. , Kosmachevskaya O. V. , Shumaev K. B. , Topunov A. F.
Published: April 2024

Low molecular weight dinitrosyl iron complexes (DNICs) with thiol-containing ligands are a physiological form for deposit and transport of nitric oxide (NO) in the organism, herewith DNICs can exhibit antioxidant and antiradical properties. It was that DNICs containing cysteine, glutathione and lipoic acid as ligands, decreased the rate of dihydrodamine oxidation by peroxynitrite formed during 3-morpholinononymine decomposition. Thiol (sulfhydryl) ligands are present in DNICs in the form of thiolate anions (R-S−), which protects these groups from oxidation by peroxynitrite. When tert-butyl peroxide was used as an oxidizer at low concentration, the protective effect of DNICs on their SH-groups was observed for complexes with lipoic acid (LA-DNIC) and with glutathione (GS-DNIC). LA-DNIC was more resistant to oxidizing agents and more effective peroxynitrite trap than other DNICs. DNICs associated with bovine serum albumin had a negligible protective effect on cysteine residue during oxidation by peroxynitrite and tert-butyl hydroperoxide. The obtained results allow us to consider low molecular weight DNICs with thiol ligands as peroxynitrite traps and thiol residues protectors in proteins.
Effect of Nε-acetylation on the Enzymatic Activity of Escherichia coli Glyceraldehyde-3-phosphate Dehydrogenase
Authors: Plekhanova N. S. , Altman I. B. , Yurkova M. S. , Fedorov A. N.
Published: April 2024

The regulation of cellular metabolism is a topic of interest for both fundamental and applied science, as the findings can be used in various biotechnological industries. One of the universal regulatory mechanisms that affects most cellular processes is the acetylation of lysine residues in central metabolic enzymes, such as glyceraldehyde-3-phosphate dehydrogenase. In this work, we investigated the effect of acetylation and deacetylation on the activity of both wild type and mutant E. coli glyceraldehyde-3-phosphate dehydrogenase. We found that in vitro acetylation of wild-type GAPDH by PatZ acetyltransferase increased its enzymatic activity by twofold, while subsequent deacetylation restored the activity to initial level. For mutant forms of glyceraldehyde-3-phosphate dehydrogenase, we demonstrated that the introduction of additional acetylation sites due to mutations altered the impact of acetylation/deacetylation processes on glyceraldehyde-3-phosphate dehydrogenase activity. Our data suggest a re-evaluation of the role of acetylation in regulating glyceraldehyde-3-phosphate dehydrogenase activity and its involvement in E. coli metabolism.
Invariant measures for contact processes with state-dependent birth and death rates
Authors: Zhizhina E. A , Pirogov S. A
Published: April 2024

We consider contact processes on locally compact separable metric spaces with birth and death rates that are heterogeneous in space. We formulate conditions on the rates that ensure the existence of invariant measures of contact processes. One of the crucial conditions is the so-called critical regime condition. To prove the existence of invariant measures, we use the approach proposed in our preceding paper. We discuss in detail the multi-species contact model with a compact space of marks (species) in which both birth and death rates depend on the marks.
The Monticellite-Bearing Rocks of the Krestovskaya Intrusion: the Genesis According to Melt Inclusion Study
Authors: Panina L. I. , Isakova A. T. , Rokosova E. Yu.
Published: April 2024

The investigation of monticellitolites and olivine-monticellite rocks from the Krestovskaya Intrusion shows that the principal minerals (olivine and monticellite) contain higher amount of MgO than same minerals in olivinites and kugdites of the Intrusion. In the studied rocks olivine contains 90–93 mol. % Fo and monticellite has 41.6–42.3 mol. % Fo whereas in olivinites and kugdites olivine and monticellite contains 86–87 mol. % Fo, and 37.2–41.2 mol. % Fo, respectively. Melt inclusion study in minerals of monticellite rocks evidenced that the monticellite rocks of the Krestovskaya Intrusion were formed due to mixing melts different in composition and volatiles: K-rich high-iron low-alumina kamafugitic melt and Na-rich high-magnesia high-alumina picritic one. Minerals crystallized at high temperatures in the following sequence: perovskite I (1250–1230°C) → perovskite II (≥1200°C) ↔ olivine (1200°C) → monticellite (1150°C). Perovskite I in monticellite rocks, as well as olivine in olivinites, crystallized from K-rich high-iron (Mg # = MgO/(MgO + FeO) – 0.37), low-alumina kamafugitic melt. During crystallization of late perovskite II in monticellite rocks, the melt became more magnesian (Mg# = 0.41) and richer in Na2O and Al2O3, which is intermediate in composition between kamafugite and alkali picritoid. Olivine in monticellite rocks crystallized from melts similar in composition to melilitite, having a K-rich composition with Mg # = 0.39, whereas monticellite formed from a heterogeneous high-magnesian Si-undersaturated melt, which is highly enriched with volatile components (including H2O) and salts. The crystallization of minerals was accompanied by accumulation of volatile components in the mixing melts and as a result by the further processes of silicate-carbonate liquid immiscibility under 1250–1190°C and by multiphase carbonate-salt immiscibility under below 1190°C. In the latter event, the separated carbonate melt began to decompose into simpler immiscible fractions: alkali-sulfate-carbonate, alkali-phosphate-carbonate and calcio-carbonate.
Compositions of Kimberlite Melts: A Review of Melt Inclusions in Kimberlite Minerals
Authors: Golovin A. V. , Kamenetsky V. S.
Published: April 2024

This work is a comprehensive review of existing data on melt inclusions entrapped in minerals of kimberlite rocks emplaced in different cratonic settings at different times. The crystallized melt inclusions represent snapshots of kimberlite melts at different stages of their evolution. All inclusions are composed of daughter minerals and shrinkage bubbles, but no aqueous fluids and quenched silicate glasses have been so far found. More than 60 mineral species were identified among the daughter phases in the inclusions, however, such diverse phase assemblages are typical of all kimberlites studied to date. Daughter minerals are represented by various Na-K-Ca-, Na-Ca-, Na-Mg-, K-Ca-, Ca-Mg-, Ca-, Mg-, Na-carbonates, Na-Mg- and Na-carbonates with additional anions Сl–, \({\text{SO}}_{4}^{{2 - }},\) \({\text{PO}}_{4}^{{3 - }},\) alkali- sulfates, chlorides, phosphates, sulfides, oxides and silicates. Alkali carbonates, sulfates, and chlorides are usually absent among groundmass minerals the majority of kimberlites in the world, except the Udachnaya-East kimberlite in Siberia. On the other hand, this paragenesis in association with traditional kimberlite minerals, such as olivine, micas, monticellite, spinel group minerals, perovskite, rutile, ilmenite, calcite, and dolomite, is common in the crystallized melt inclusions in all studied kimberlites. Carbonates (~30 to 85 vol. %) always dominate over silicates (only up to 18 vol. %) within inclusions. All inclusions also contain variable (2 to 55 vol. %.) amounts of chlorides (halite and sylvite). When relatively low abundances of carbonate minerals (30–50 vol. %) are observed in the inclusions, chlorides (18–55 vol. %) appear to take over other minerals, including silicates that are traditionally considered as main components of “ultramafic” kimberlite parental melts. The published results on melt inclusions in the kimberlite minerals strongly imply that parental kimberlite melts were generated and further evolved within the Na2O-K2O-CaO-MgO-CO2-Cl system, that is, they were alkali-rich carbonatite/carbonatite-chloride liquids. According to various estimates, the SiO2 content in kimberlite melts at different stages of their evolution could have varied from the first to 19 wt. %. Obviously, during and after of а kimberlite bodies formation, interaction with external waters leads to serpentinization of kimberlite olivine and dissolution of a significant part of kimberlite igneous minerals, such as alkaline carbonates, sulfates, and chlorides. In the traditional approach to studying kimberlites, the role of components such as Na2O, CO2, Cl, and to a lesser extent K2O and S, F in the petrogenesis of kimberlite magmas and rocks have been largely underestimated, while olivine- and serpentine-forming components, such as of SiO2, MgO and H2O are still overestimated in contemporaneous literature.
Sulfide Mineralization in Pyrometamorphosed Upper Crustal Xenoliths, Bezymianny Volcano, Kamchatka
Authors: Davydova V. O. , Shcherbakov V. D. , Nekrylov N. A. , Plechov P. Yu. , Yapaskurt V. O.
Published: April 2024

Bezymianny volcano supply on the surface numerous xenoliths, revealing the composition of the crust containing the magmatic system and the processes occurring within it. In this study, we present data on the xenoliths from the upper crust that were partially melted and recrystallized (pyrometamorphosed) in the shallow chamber of Bezymianny volcano. Some xenoliths contain relics of primary igneous associations, and some contain relics of prepyrometamorphic hydrothermally alteration. Thus, protoliths of pyrometamorphosed rocks could be reconstructed, and hydrothermal processes could be determined for rocks previously altered with fluids. The most common xenoliths are moderate-K andesites, basaltic andesites, and basalts from Kamen and Bezymianny volcanoes. During pyrometamorphism, a new microgranoblastic paragenesis forms, consisting of homogenous pyroxenes, plagioclase, and Fe-Ti oxides, sometimes surrounded by glass. Xenoliths of plateau basalts from the Klyuchevskaya group of volcanoes (high-K trachyandesitic basalts) are less common. Some of plateau basalt xenoliths contain trace of quartz-carbonate-sulfide mineralization, which was formed before the capture of xenoliths and their pyrometamorphism. A hydrothermally altered rock was melted and recrystallized after xenoliths were captured by magma, resulting in a Fe-wollastonite-hedenbergite association (sometimes with garnet), which is not typical for Bezymianny. The copper content of these xenoliths is anomalously high (up to 1500 ppm).
Microprobe Analysis of Titanium in Zircon: an Estimation of Secondary Fluorescence
Authors: Borisov A. A. , Borisovskiy S. E. , Koshlyakova A. N.
Published: April 2024

Microprobe study of the effects of secondary fluorescence from high-titania glass (TiO2 ≈ 16 wt %) on apparent titanium content in Ti-free zircon was conducted. It was demonstrated that small crystals (10 µm) are not suitable for analysis. In boundary parts of large zircon crystals (20–30 µm) the error in Ti estimation may reach 10–23%. However, in central parts of large crystals ( 30 µm) the microprobe analysis gives practically undistorted titanium contents.
Variations in the Composition of MORB Chilled Glasses from the Mid-Atlantic Ridge, 12°–31° N: Reflection of Composition Evolution of Parent Melts and the Influence of the Hydrothermal Component
Authors: Silantyev S. A. , Buikin A. I. , Zhovrebova A. R. , Shabykova V. V. , Bel’tenev V. E.
Published: April 2024

The geochemical peculiarities of sample collection of MORB chilled glasses obtained in six areas of the axial zone of the Mid-Atlantic Ridge (MAR), 12°–31° N have been studied. The results of this study provided information on the composition of the parent melts for these glasses and made it possible to assess probable geochemical effects reflecting the interaction of magmatic melts with hydrothermal systems of the MAR axial zone or with altered oceanic crust (AOC). It is shown that basalts of the E-MORB family which includes most of samples are localized mainly in the “cold” segments of the MAR in the crustal section of which serpentinites predominate. On the other hand, samples with depleted signature (N-MORB) belong to segments of the MAR in which serpentinite outcrops are either absent or play a subordinate role. The E-MORB chilled glasses from “cold” segments of the MAR show signs of contamination of basaltic melts with components borrowed either from the host serpentinites or from aqueous-saline fluids circulating in hydrothermal systems located in serpentinites (“serpentinite hosted”). Judging by the data obtained on the nature of variations in the content of Cl, U, and Sr in the studied chilled glasses belonging to the N-MORB family, there are no signs of intracrustal contamination. It is assumed that relics of the ancient continental lithosphere preserved under axial zone of the MAR and involved in the process of partial melting of the shallow mantle took part in the formation of E-MORB parental melts in some segments of the MAR.
Radiation Biology of Structurally Different Drosophila melanogaster Genes. Message 9. General Regularities and Locus-Specific Features of Radiomutability of Sex-Linked and Autosomal Genes
Authors: Alexandrov I. D. , Alexandrova M. V. , Afanasyeva K. P. , Rusakovich A. N. , Harchenko N. E.
Published: April 2024

The results of large-scale radiation, genetic, cytogenetic and molecular genetic studies on the nature and frequency of heritable mutations of two sex-linked and three autosomal genes of Drosophila melanogaster after exposure to 60Co γ-rays and 0.85 MeV neutrons are presented. Regularities were established for studied genes and radiations in the induction of five different types of recessively inherited mutations, which can be combined into two main classes - the class of chromosomal mutations in one way or another affecting the gene under study (changes leading to sterility of F1 mutants, multilocus deletions, inversion or translocation breakpoint chromosome in the region of gene localization) and a class of “point” gene mutations with a complex spectrum of DNA changes detected by PCR and sequencing. In this report, the results of classical genetic and cytogenetic analysis of these classes of mutations are considered in detail and the frequency of their induction by γ-rays or neutrons is estimated per locus per dose unit (1 Gy). An important and unexpected result of the assessment was the fact that the frequency of “point” mutations turned out to be invariant (on average 1.15 E-06/locus/Gy) for the studied genes and radiations, in contrast to chromosomal mutations, where a pronounced locus-specificity is observed for individual types of mutations. At the same time, neutrons are two or more times more effective than γ-rays in inducing this class of mutations. It is significant that the ave-rage frequency of “point” mutations induction correlates with the average cDNA length of these genes (1.62 kb), but not with their average size (6.07 kb), indicating that the target for " point mutations is, obviously, not the entire DNA of the gene, but only the informational part of its exons. The dependence of the frequency of chromosomal mutations of one type or another on the position of the gene on the chromosome and in the three-dimensional space of the genome is discussed.
Foreshadowing the Future of Genetic Engineering and Radiobiology: 100 Years From the Beginning of N.V. Timofeeff-Ressovsky’s Scientific Work
Authors: Klabukov I. D. , Yakimova A. O. , Baranovskii D. S. , Yatsenko E. M. , Petrov V. A. , Zhavoronkov L. P. , Ivanov S. A. , Shegai P. V. , Kaprin A. D.
Published: April 2024

The year 2021 was marked with a significant date – 100 years ago, brilliant radiobiologist and geneticist N.V. Timofeeff-Ressovsky started his scientific work. Among the new directions developed by him from 1921 to 1981 were physical biology, basic principles of genetic engineering, amplifier principle, and population radiobiology. It is noteworthy that many of his ideas were developed in the former Department of Radiation Genetics and General Radiobiology of the Institute of Medical Radiology in Obninsk, which is now called the Experimental Sector of the A. Tsyb Medical Radiological Research Centrе. Our work reveals the interconnections of Timofeeff-Ressovsky’s works with the activities of his contemporaries and productive ideas of today.
Cataractogenic Effects оf Low-Dose Radiation with Low LET: More not Than There. Report 1. Statement оf тhe Problem аnd Experiments оn Animals
Authors: Koterov A. N. , Ushenkova L. N.
Published: April 2024

Radiation disturbances in the lens are considered as the third most important effects of radiation, after mortality from cancer and diseases of the circulatory system (ICRP-118). In terms of the problem of the effects of low doses radiation with low LET (up to 100 mGy), interest in the dose relationship for the induction of disturbances in the lens after irradiation increases in a linear progression, as evidenced, among other things, by the chrono-dynamics of the increase in the number of relevant reviews by years shown here (since 2007; r = 0.650; p = 0.006). However, there is still no clarification of the question of the evidence of the effect of low doses on the lens. This study, consisting of two reports, attempts to fill this gap. Since epidemiological associations to confirm causality should, if possible, meet the criterion of “Biological plausibility”, this Report 1 reviewed the work considered in thematic publications on the cataractogenic effects of the lowest doses of radiation with low LET in experiments in vitro and in animals. The extreme radiosensitivity of the lens cells, exceeding even the parameters of lymphocytes in terms of induction of DNA double-strand breaks, is confirmed in a number of works (an increase in the level of breaks is shown even for a dose of 20 mGy). However, when the dose regularities are transferred to the irradiation of mice and rats in vivo, the conclusions about the effects of low doses are not confirmed. A sample of works over more than 70 years did not reveal such effects. The three exceptions (not included in PubMed paper cited in a single source, a workshop presentation, and an arbitrary textbook mention without citation) do not serve as valid scientific sources. The singularity of these data does not fall under the criterion “Consistency of association”. The smallest threshold doses of radiation for the induction of cataractogenic effects in mice are, according to studies as early as the 1950s, ~114 mGy and ~140 mGy for X-rays. The value of 150 mGy is also called (Shafirkin A.V., Grigoriev Yu.G., 2009). However, one should adhere to the results of more recent studies, according to which, when exposed to radiation in mice, a tendency to opacity in the lens can be observed for a dose of 0.2 Gy, with a statistically significant fixation of the effect for a dose of only 0.4 Gy. Most sources in experiments on rodents report threshold doses in units of gray, with a minimum of 0.5 Gy. Thus, the effects of low doses on the lens opacity were not found in the experiment.
The Comet Assay Did Not Reveal a Decrease in DNA Damage to Lymphocytes when Exposed to X-Ray Radiation under the Action of Na-Cu-chlorophyllin
Authors: Romodin L. A. , Ignatov M. A.
Published: April 2024

The search for effective but non-toxic radioprotective agents remains the main task of radiobiology. Accor-ding to a number of reports, these may include preparations based on chlorophyll, in particular, chlorophyllin – a water-soluble product of its saponification. Since many researchers assign DNA damage a key role in the development of negative consequences of ionizing radiation, we conducted an experiment on X-ray irradiation of a suspension of lymphocytes in solutions of sodium-copper chlorophyllin in the concentration range of 5–100 micromoles. During it, using an alkaline modification of the gel electrophoresis method of individual cells, we found no significant differences in the DNA content in the tail and the tail moment of the DNA comets of irradiated lymphocytes incubated in chlorophyllin, compared with only irradiated cells. We explain this result by the fact that, most likely, chlorophyllin does not pass into the cell nuclei. And therefore it cannot show its antioxidant role in them.
Interleukin-6 Role in Schizophrenia Pathological Mechanisms
Authors: Rukavishnikov G. V. , Zhilyaeva T. V. , Dubinina E. E. , Mazo G. E.
Published: April 2024

It is assumed that schizophrenia may consist of extremely heterogeneous group of phenotypes with different biological and neurochemical pathological mechanisms. At the same time, much attention is paid to the potential role of the immune system in the development of schizophrenia and, in particular, the participation of various cytokines in these processes. Interleukin-6 (IL-6) is one of the key regulators of inflammatory processes. A number of studies have previously reported changes in its levels in patients with schizophrenia. However, data on the specificity of these changes in the literature are much less well-documented and sometimes even contradictory. The dichotomous functioning of IL-6 may play a key role in the regulation of both pro- and anti-inflammatory processes. In this regard, the role of this cytokine in the etiopathogenesis of schizophrenia may depend on the phase of the disease and the context of the inflammatory process. The aim of this review was to analyze in detail the role of IL-6 in the mechanisms of schizophrenia and its potential impact on the course, diagnosis and therapy of this disease.
Creation and Study of the Mechanism of Action of Compounds of a New Class of Positive Modulators of AMPA Receptors – Derivatives of 3,7-Diazabicyclo[3.3.1]nonanes
Authors: Grigoriev V. V. , Lavrov M. I. , Palyulin V. A. , Garibova T. L. , Anokhin K. V. , Bachurin S. O.
Published: April 2024

The review presents the results of consistent scientific studies of a new class of positive allosteric modulators of AMPA receptors from the class of 3,7-diazabicyclo[3.3.1]nonane derivatives, starting from the theoretical prediction of the structures of compounds, their synthesis, and studying their effect on the currents of AMPA receptors as evidence of assignment them to the PAM class, studying their activity and effectiveness in behavioral experiments simulating both various acute impairments of memory and cognitive functions, and in chronic experiments simulating the pathology of Alzheimer’s disease, studying their molecular mechanism of interaction with the AMPA receptor using 3D computer modeling, radioligand studies of labeled compound 5 with fractions of synaptic membranes of the brain hippocampus in order to determine the “seats” of this PAM in the brain of rats. All of the above characterizes new compounds of this class as the most active among known PAMs in the world, having a pronounced cognitive-stimulating effect both in normal animals and in various models of pathological memory disorder, which indicates their great therapeutic potential.
Investigation of the Crystal Structure of Nd5Mo3O16 + δ in the Pressure Range 0–5.9 GPа
Authors: Chebyshev K. А. , Turchenko V. А. , Kichanov S. Е.
Published: April 2024

Neodymium molybdate with a cubic fluorite-like structure was obtained by solid state reactions from metal oxides. The formation of the final product occurs through the formation of a monoclinic structure of Ln2MoO6 type (space group C2/c) at 700°C, which probably contains vacancies in neodymium and oxygen lattices. Neodymium molybdate obtained at 900°C crystallizes in the space group Pn\(\bar {3}\)n with the cell parameter a ≈ 11.039 Å. The crystal structure of neodymium molybdate obtained at 700 and 900°C was studied by neutron diffraction and atomistic modeling using the GULP program in the pressure range 0–5.9 GPa, which demonstrated the stability of the cubic structure at elevated pressure.
Field Frequency Variation during Plasma-Chemical Deposition of Silicon-Carbon Films as a Method for Their Structural Modification
Authors: Popov A. I. , Barinov A. D. , Yemets V. M. , Presnyakov M. Yu. , Chukanova T. S.
Published: April 2024

The influence of the electric field frequency in the range from 0.1 to 2.0 MHz during plasma-chemical deposition of diamond-like silicon-carbon films on their chemical composition, structure, and electrical properties has been studied. It is shown that the films obtained in the entire studied frequency range have an amorphous structure with a constant, within the measurement precision, chemical composition. At the same time, the morphology of the surface of the films and their electrophysical properties significantly depend on the frequency of the electric field during plasma-chemical deposition. This makes it possible to use the change in the field frequency in the preparation of films as a method of controlling their properties. The frequency range providing the most effective modification of electrophysical properties is determined.
The SKIF X-Techno Beamline Project
Authors: Nazmov V. P. , Goldenberg B. G.
Published: April 2024

Beamlines nowadays installed at synchrotron radiation centers typically pose different and sometimes even incompatible requirements to X-ray beams being utilized. Some techniques require minimum attainable beam cross-sections in order to enable microbeam techniques with the sample mapping. To the contrary, relatively broad X-ray beams with the uniform intensity distribution are needed to address problems related to X-ray irradiation-based processing of materials or fabrication of components and devices with X-ray lithography approaches. The present paper describes the concept of a novel beamline named X-Techno proposed for the synchrotron radiation facility SKIF. It would use synchrotron beams as wide as 100 mm in the horizontal plane in different spectral ranges with either out of three experimental chambers to study materials and manufacture micro and nanostructures. The beamline will be specifically suitable for studies of physicochemical properties of materials under intense X-ray irradiation within the spectral range from 2 to 70 keV.