bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Problems of Detecting Fast Radio Bursts with the LPA LPI
Authors: Brylyakova E. A. , Tyul’bashev S. A.
Published: April 2024

We present a verification of fast radio bursts (FRBs) previously published by V.A. Fedorova and A.E. Rodin. These FRBs were found in the monitoring data with the Large Phased Array (LPA) radio telescope using a search algorithm based on data convolution with a scattered pulse pattern. The same 6-channel data (channel width 415 kHz) were used for verification, in which FRBs were found with dispersion measures of 247, 570, and 1767 pc/cm3. An additional verification of the published FRBs was also carried out in 32‑channel data (channel width 78 kHz). We can not confirm any of the published FRBs on the signal-to-noise ratios claimed in the original paper. The main errors are caused by incorrect determination of the baseline and incorrect estimation of noise standard deviations.
Search for Pulsars in an Area with Coordinates 3h < α < 4h and +21° < δ < +42°
Authors: Tyul’bashev S. A. , Tyul’basheva G. E.
Published: April 2024

The search for pulsars outside the plane of the galaxy in an area of 300 sq. deg. was carried out with the LPA LPI antenna at 111 MHz, with a sensitivity 5 to 10 times better than that of previous surveys. The search was performed in the summed power spectra. With an accumulation time equivalent to 100 hours of continuous observations for each point of the area, 5 known pulsars were found with a signal-to-noise ratio (S/N) from 20 to 1300 in the first harmonic of the spectrum. Average profiles are obtained for the detected pulsars. Estimates are given for the peak and integrated flux densities of the found pulsars for individual sessions and for power spectra summed over 5.5 years, using the developed method based on measurements of harmonic heights in the power spectrum. No new pulsars were found in the area. Apparently, when searching for pulsars in the area, we approached the lower limit of the luminosity of second pulsars. The survey completeness is at the level of 0.5 mJy.
Large-Scale Convection during Gravitational Collapse with Neutrino Transport in 2D and 3D Models on Fine Grids
Authors: Aksenov A. G. , Chechetkin V. M.
Published: April 2024

The problem of the gravitational collapse of the core of a massive star is considered, taking into account the neutrino transport in the flux-limited diffusion approximation. To reduce the computational domain of a multidimensional problem on a fixed computational grid, the core of a star, which is already at the stage of collapse, is considered. Since the collapse stage is delayed in time compared to the gas-dynamic time scale for an emerging proto-neutron star, we consider the mathematical problem for the initial configuration in equilibrium and neglected the initial radial velocity. Pressure for a long time at the collapse stage is provided by relativistic degenerate electrons, so the relationship between pressure and density in the initial configuration is described by a polytropic equation with the polytropic index n=3. The purpose of this paper is to test the hypothesis that large-scale convection is independent of the 2D and 3D geometry of the mathematical problem and computational grid parameters, as well as the choice of the initial stage of gravitational collapse. The scale of convection is determined by the size of the region of decreasing entropy with neutrino losses, i.e., nonequilibrium neutronization, and the presence of a weak initial rotation.
The Structure of the Universe in the Quasar Absorption Spectra
Authors: Demiański M. , Doroshkevich A. , Larchenkova T.
Published: April 2024

An analysis of the absorption lines observed in the spectra of quasars makes it possible to study the evolution of the structure of the Universe up to redshifts z∼5. The observed clustering of C IV lines demonstrates the multiple birth of low-mass galaxies in separate structural elements—filaments and “pancakes.” This ensures their subsequent regular hierarchical merger in the central galaxy or group of galaxies. Remnants of the early “pancakes” are observed today as the Local Group, groups around the Andromeda and Centaurus galaxies, and other small groups of galaxies. In turn, the observed clustering of Lyman-alpha lines shows that starless dark matter (DM) halos are also formed in structural elements and their hierarchical clustering leads to the formation of massive starless dark matter halos of moderate density, which also appear in numerical models.
Method of Circular Gaussian Rings in Perturbation Theory
Authors: Kondratyev B. P. , Kornoukhov V. S.
Published: April 2024

An extended approach to the model of circular Gaussian rings is developed to study the secular evolution of the orbits of two planets under the influence of mutual gravitational perturbation. The orbits of the planets have a small mutual inclination angle and are represented by circular rings, on which the masses, semimajor axes and inclination angles of the orbits, as well as the orbital angular momenta of the planets are transferred. The role of the perturbation function in the problem is played by the mutual gravitational energy of the rings, which is obtained in integral form and as a series in powers of slope angles. The coefficients of the series are expressed in terms of elliptic integrals. The method for the first time considers the discrepancy between the nodes of the planets’ orbits and has been developed in two versions: (i) with a large and (ii) small angles between the nodes of the orbits. For each of these options, systems of 4 differential equations describing the secular evolution of orbits are compiled and solved in the final analytical form. It is proved that the angle of mutual inclination of the orbits remains constant in the process of evolution in both cases. Option (i) is tested on the example of the Sun–Jupiter–Saturn; option (ii) is tested on the evolution of orbits of exoplanets Kepler-10b and Kepler-10c. For both systems, the precession parameters were calculated and the diagrams were plotted.
INVESTIGATION OF OH 18 CM MASER EMISSION AND MAGNETIC FIELD IN THE S128 STAR FORMATION REGION
Authors: Ashimbaeva N. T. , Lekht E. E. , Krasnov V. V. , Tolmachev A. M.
Published: April 2024

The results of a study of the variability of OH maser emission in the lines of 18 cm in the S128 star formation region from monitoring data in 2007–2022 at the Large Radio Telescope in Nançay (France) are presented. Maser emission was observed in the main line of 1665 MHz during the entire monitoring, and only short-term emission was observed in the satellite lines of 1612 and 1720 MHz. For the four strongest features in the 1665 MHz line, the variability of the positional angle of linearly polarized emission was found. The dependence of the angle on the radial velocity to some extent resembles a limited sinusoid, which may be due to the existence of an organized spatial structure of maser spots and the associated transverse magnetic field. For two Zeeman pairs in the 1612 MHz line having similar radial velocities (–75.344/–75.236 and –74.980/–74.903 km/s), the detected splits have opposite signs and, therefore, opposite directions of the longitudinal magnetic field. The directions of the transverse magnetic field vectors are also determined for these features. Apparently, the magnetic field is swirling and is associated with a swirling molecular outflows of matter.
SEASON VARIATIONS OF ASTROCLIMATE PARAMETERS FOR THE TERSKOL OBSERVATORY
Authors: Bolbasova L. A. , Kopylov E. A.
Published: April 2024

We present results of the study of seasonal variations of the astroclimate parameters for the Terskol Observatory: wind speed at the level of 200 mbar as a measure of the adaptive optics (AO) applicability, the wind speed altitude distribution, determining the requirements for the AO performance, moisture content to assess the possibility of AO operation in the IR range, the parameters of the mesospheric sodium layer, determining the brightness of the laser reference star for AO systems, in connection with the task of designing adaptive optics for the Zeiss-2000 telescope. Data on surface wind speed and total cloud cover are also analyzed to assess the available observation time. The data of atmospheric reanalysis were used, with the help of which the parameters under consideration have been studied in large astronomical observatories, as well as satellite data of measurements of mesospheric sodium and full-scale changes in surface wind velocity.
PROSPECTS FOR OBSERVING BINARY SUPERMASSIVE BLACK HOLES WITH THE SPACE RADIOINTERFEROMETER
Authors: Malinovsky A. M. , Mikheeva E. V.
Published: April 2024

A list of candidates for binary supermassive black holes, compiled from available data on optical band variability and emission spectrum shape, has been analysed. An artificial neural network has been constructed to estimate the radiation fluxes at the frequency 240 GHz. For those candidates of binary supermassive black holes for which the network building procedure proved possible, the criterion of possibility to observe the source at the Millimetron Space Observatory was tested. The result of this study is presented as a table of 17 candidates for binary supermassive black holes. Confirmation (or refutation) of the binarity of these objects by means of observational data commited on a space interferometer with parameters similar to those of the Millimetron Space Observatory will be an important milestone in the development of the theory of galaxy formation.
MODERN ESTIMATES OF THE MASS OF THE MILKY WAY
Authors: Bobylev V. V. , Baykova A. T.
Published: April 2024

An overview of various methods used to estimate the mass of the Galaxy is given. The results obtained on the basis of the analysis of the galactic rotation curve, on the kinematics of dwarf satellite galaxies of the Milky Way, on globular clusters, on the streams of dwarf galaxies, on distant halo stars, on escape velocities, on the dynamics of the Local group of galaxies, as well as results of N-body modeling are included. Estimates of the mass of the Galaxy \(M\) of the form (i) \(M( r)\), i.e. the mass enclosed inside a sphere with a radius of \(r\), (ii) \({{M}_{{200}}}\), where r 0 kpc, and (iii) virial estimates, \({{M}_{{{\text{vir}}}}}\). Such estimates were selected by us based on literary data,a significant part of which was obtained in the Gaia era. According to 20 individual estimates, the average value was found \({{\bar {M}}_{{200}}} = 0.88 \times {{10}^{{12}}} {{M}_{ \odot }}\) with a variance of \(0.24 \times {{10}^{{12}}} {{M}_{ \odot }}\) and a weighted average error of \(0.06 \times {{10}^{{12}}} {{M}_{ \odot }}\). According to 28 individual estimates we obtained \({{\bar {M}}_{{{\text{vir}}}}} = 1.05 \times {{10}^{{12}}} {{M}_{ \odot }}\) with variance \(0.44 \times {{10}^{{12}}} {{M}_{ \odot }}\) and a weighted average error of \(0.09 \times {{10}^{{12}}} {{M}_{ \odot }}\).
THIN AND THICK DISKS AROUND BLACK HOLES AND WORMHOLES
Authors: Chernov S. V.
Published: April 2024

The paper investigates the distribution of matter in thick disks around black holes and wormholes numerically and analytically. Metrics are considered Kerr and Lamy. Accurate analytical solutions are written out. The influence of a toroidal magnetic field on the structure of a thick disk is taken into account. Images of a thin disk are constructed depending on the values of the metric parameters.
DETERMINATION OF THE CLOSE BINARY SYSTEMS PARAMETERS BY SYNTHESIS METHODS: FROM WHITE DWARFS TO WOLF–RAYET STARS AND BLACK HOLES
Authors: Antokhina E. A. , Antokhin I. I.
Published: April 2024

Synthesis methods for light and radial velocity curves are currently one of the main tools for studying close binary systems (CBS). The paper gives a brief overview of the history and development of the methods and their implementations at the SAI MSU, where a set of computer programs has been created to analyze observations of various types of CBS. As a demonstration, we present the results of the analysis by our algorithms of three interesting CBSs at different evolutionary stages. An analysis of the unusual light curves of the recently discovered pre-cataclysmic binary GPX-TF16E-48 was performed using the Roche model with spots on the normal star. The X-ray light curves of the microquasar SS433 were analyzed in a model with a precessing accretion disk. Thanks to the photometric data obtained from space, the highly elliptical Wolf–Rayet binary WR22 was studied in the Roche model accounting for the absorption in the powerful wind of the Wolf–Rayet star. As a result of this detailed analysis of the light curves and involving spectroscopic information, the parameters of the CBSs and their components were found. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.
MASS RATIO AND ECCENTRICITY DISTRIBUTIONS OF YOUNG SPECTROSCOPIC BINARY STARS
Authors: Eretnova O. V.
Published: April 2024

We collected the information about 83 pre-main sequence double-lined spectroscopic binaries. Among them there are Ae/Be Herbig stars, T Tauri stars and red dwarfs. The eccentricity – period relation, the mass ratio and eccentricity distributions of young spectroscopic binaries are constructed and analyzed. The overwhelming majority of close binaries with \(P {{10}^{d}}\) have eccentricity near to zero, the stars less than 1 million years old are rare among them. The mass ratio distribution of systems with \(P {{10}^{d}}\) has a prominent maximum in a range of \(q = 0.9{\kern 1pt} - {\kern 1pt} 1.0\). The number of young spectroscopic binaries with \(P {{10}^{d}}\) does not decrease with decreasing mass ratio as sharply as in the case of close binary stars, about 12% of these stars have \(q 0.5\). The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.
PECULIARITIES OF LONG-TERM SPOT ACTIVITY OF SOME LATE SPECTRAL-TYPE STARS
Authors: Kozhevnikova A. V. , Alekseev I. Yu. , Kozhevnikov V. P.
Published: April 2024

We present an analysis of long-term photometric observations of several dozen chromospherically active stars with solar-type activity (both from our own observations and from data available in the literature). The distribution of cold photospheric spots has been modeled based on a zonal model – several hundred models have been obtained. It has been found that the majority of stars have spots located at middle and moderate latitudes, the maximum spot areas can occupy from 7 to 58% of the star’s surface. It is shown that for some stars we can suspect the drift of spots in latitude, both towards the equator and towards the pole. However, the speed of such a drift is several times lower than that of sunspots. The presence of stellar activity cycles in 15 stars was revealed: cycles last from 3 to 28 years and expressed in changes in the brightness of the system, as well as in changes in the total spottedness of the star. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.
WORKSHOP “NOVELTIES IN UNDERSTANDING THE EVOLUTION OF BINARY STARS”
Authors: Samus’ N. N.
Published: April 2024

In February 2023, the Ural Federal University (Ekaterinburg, Russia) hosted a seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of the founder of the Ural science school of researchers in close binary systems, Professor Marij Anatolyevich Svechnikov. 17 scientific talks were given at the workshop, united by their interest in the problems of stellar binarity.
THE ROLE OF BINARY STARS IN UNDERSTANDING THE PHYSICS AND EVOLUTION OF STARS
Authors: Tutukov A. V.
Published: April 2024

The diversity of close binary stars (CBS) and the rich manifestation of their activity as a result of the interaction of stellar components have turned their observed family into a very developed and effective tool for studying the evolution of stars. This review presents the main features of modern ideas about the evolution of CBS from their origin to the formation of finite compact remnants of components: degenerate dwarfs, neutron stars and stellar black holes. The main phenomena related to their interaction with each other and accompanying the process of fusion of compact components of the CBS are also listed, taking into account the effect of common envelopes, radiation of gravitational waves in cataclysmic and X-ray binaries, supernovae (SN Ia, SN Ib), gamma-bursters and other systems. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.
NEXT GENERATION GRAVITY MISSIONS: STUDYING THE POSSIBILITIES OF MULTIPLE CONSTELLATION
Authors: Filetkin A. I. , Zhamkov A. S. , Ayukov S. V. , Milyukov V. K.
Published: April 2024

We study potential possibilities of space constellation consisting of two pairs of spacecraft moving in different orbits, the so-called next generation gravity missions, aimed at increasing the spatial and temporal resolution of measurements and improving the accuracy of the recovery of the Earth’s gravity field. As a result of numerical simulation of the orbital motion of the multiple spacecraft constellation and solving the inverse problem of recovering the Earth’s gravitational field based on model measurements performed in this constellation, a multiple configuration with orbital parameters \(h = 370\) km, \(i = 90.5^\circ \) and \(h = 370\) km, \(i = 70.0^\circ \), was found. Such a multiple constellation makes possible to increase both the spatial and temporal resolution of the Earth’s gravity field models with a significant refinement of zonal, sectorial and tesseral harmonics compared to the one-pair near-polar configuration.
HIGH RESOLUTION OPTICAL SPECTRA OF THE DORMANT LBV STAR P Cyg
Authors: Klochkova V. G. , Panchuk V. E. , Tavolzhanskaya N. S.
Published: April 2024

High resolution optical spectra (R = 60 000) of the dormant LBV star P Cyg were obtained on the BTA telescope in the wavelength range \(\Delta \lambda G7 = 780\) nm. After performing a detailed identification of different types lines (photospheric absorptions, permitted and forbidden emissions, components of lines with profiles of type P Cyg), we studied the variability of their profiles and patterns of radial velocities. The average radial velocity from positions of forbidden emissions ([N II] 5754.64, [Fe II] 5261.62, [Fe II] 7155.14 and [Ni II] 7377.83 Å) is accepted as the system \({{V}_{{{\text{sys}}}}} = - 34 \pm 1.4\) km/s. About a dozen photospheric absorptions of CNO-triad ions and Si III are found, their stable position, \({{V}_{r}}({\text{abs}}) = - 73.8\) km/s, shifted relative to \({{V}_{{{\text{sys}}}}}\) at \( - 40\) km/s, indicates that these absorbtions are formed in the pseudophotosphere region. The high-excitation emissions ([O I] 5577, 6300, 6363 Å, [O III] 4959 and 5007 Å, as well as He II 4686 Å) are absent in the spectra. The radial velocity \({{V}_{r}}({\text{DIBs}}) = - 11.8\) km/s according to the position of numerous DIBs is consistent with the position of the interstellar components of the D-lines Na I and K I forming in the galactic Perseus arm. An excess of color \(E(B - V) = 0.34 \pm {{0.03}^{m}}\) and interstellar absorption \({{A}_{v}}{{ = 1.09}^{m}}\) were determined by measurements of equivalent widths of nine DIBs.
Induction of damage to the dna structure of tumor cells by aurum polyacrylate
Authors: Chigasova A. K , Ostrovskaya L. A , Korman D. B
Published: April 2024

The ability of aurum polyacrylate (aurumacryl) to cause changes in the DNA structure of tumor cells (culture of MCF-7 human breast cancer cells) was studied. It was established that the molecular mechanism under- lying the effects of aurumacryl on tumor cells is associated with the induction of single-strand breaks and cross-links in the DNA molecule. At the same time, it was shown that aurumacryl can reduce the number of spontaneous, or irradiated, DNA double-strand breaks in MCF-7 cells.
Meconic acid is a possible neuroprotector: justification on in vitro experiments and its physico-chemical properties
Authors: Kozin S. V , Ivashchenko L. I , Kravtsov A. A , Vasilyeva L. V , Vasiliev A. M , Bukov N. N , Dorohova A. A , Lyasota O. M , Bespalov A. V
Published: April 2024

Main representatives of gamma pyronic acid are meconic, comenic, chelidonic and kojic acid. It was found that comenic acid exerts a neuroprotective effect, and chelidonic acid has a pronounced anti-inflammatory effect. It was not studied whether meconic acid exhibits neuroprotective effects. The aim of this work was to assess the neuroprotective potential of meconic acid, taking into accout its physicochemical properties, using an in vitro model of ischemic stroke. Primary neuroglial culture was obtained from the cerebellum of 7-8-day-old Wistar rat pups by mechanical tissue dissociation. The protective effect of meconic acid on the culture of cerebellar neurons was studied using the model of glutamate toxicity and oxygen-glucose deprivation. Quantum mechanical calculations were used and experiments in the model system citrate-phosphate-luminol were conducted by the method of chemiluminescent analysis to investigate the antioxidant activity of meconic acid. The chelating properties of meconic acid with respect to Fe3+ in solutions were studied using Job's method. Meconic acid has been found to have a protective effect in in vitro models of ischemia. Its action leads to a decrease in the level of intracellular calcium and the restoration of the membrane potential of mitochondria in a culture of cerebellar neurons under glutamate exposure, resulting in an increase in the percentage of living cells under oxygen-glucose deprivation. Meconic acid has a high calculated antioxidant potential, confirmed experimentally. With an increase in the pH of the medium, stepwise binding of meconic acid with Fe3+ occurs with the formation of complexes with different ligand/metal ratios. At physiological pH, the composition of the resulting complex is 1:3. The obtained antioxidant, chelating, and cytoprotective action of meconic acid provides a basis for further study of the possible neuroprotective properties of this compound in in vivo experiments, and the data obtained in the work on its physicochemical properties can be useful for the synthesis and study of new coordination compounds based on meconic acid.
Study of heme and globin conformation in fractionated rat erythrocytes by means of raman spectroscopy
Authors: Yushkov B. G , Zuev M. G , Brilliant S. A , Vasin A. A
Published: April 2024

Conformational changes of heme and globin in fractionated rat erythrocytes have been investigated using Raman spectroscopy. The results obtained show that normal isoforms (common variants) of hemoglobin, which plays a key role in oxygen transport and a protective role against oxidative stress, are dominant (more than 80%) in rat blood. However, heavy chain (3%) and light chain isoforms (11%) formed as a result of protein polymerization or degradation perform important roles in the body because they also function in signal transmission and binding to exogenous ligands.
Comparative analysis of the nitrogen monoxide content and optical-morphometric characteristics of erythrocyte-containing blood components during storage
Authors: Akulich N. V , Zinchuk V. V
Published: April 2024

Flow cytometry was used to analyze the content of intracellular nitrogen monoxide in erythrocyte-containing blood components during blood storage with hemopreservative for 4 weeks. It was found that storing of blood is accompanied by increased levels of intracellular nitrogen monoxide in erythrocytes and thus by a change in optical and morphometric parameters of red blood cells. In the early stages of storage, erythrocytes were represented by discocytes, and during long storage erythrocytes became more spherical (spherocytes) as the percentage of microcytes that accumulated nitrogen monoxide increased and their intracellular hemoglobin levels were decreased.
Pathogenetic mechanisms of burn disease associated with oxidative membrane damage and ways of their correction
Authors: Vilyanen D. V , Pashkevich N. I , Borisova-mubarakshina M. M , Osochuk S. S
Published: April 2024

Despite significant progress in the treatment of burn disease, mortality in this pathology can exceed 50% owing to the development of multiple organ dysfunction syndrome when more than 30% of the body surface area is affected. The review describes the most important molecular and biological mechanisms that underlie the development of multiple organ dysfunction syndrome in which free-radicals cause damage to plasma membranes, mitochondria, damaged mitochondria generate other free radicals, mitochondrial DNA is modified and used as a trigger of inflammatory processes in peripheral organs and systems. Secondary changes in the system of lipid transport in the blood and their role in generalization of multiple organ failure and hormonal imbalance are considered. In view of pathogenic metabolic shifts, use of antioxidants (such as quinones) in combination with lipid metabolism modulators is a reasonable strategy to reduce the activity of the inflammatory process and hormonal imbalance in the treatment of burn disease.
Simulation modeling of glutamate cysteine ligase activity
Authors: Kopylova V. S , Boronovskiy S. E , Nartsissov Ya. R
Published: April 2024

L-Y-glutamyl-L-cysteinyl glycine, or glutathione, as one of the basic intracellular antioxidants, plays a vital role in cellular metabolism. In mammalian cells, glutathione is synthesized via two steps. The first step that is considered rate limiting is catalyzed by glutamate cysteine ligase. In this work, a stochastic algorithm based on continuous-time Markov chains was used to simulate the activity of glutamate-cysteine ligase. Several different mechanisms of enzymatic activity including reversible inhibition of glutathione, and an ATP binding motif have been considered. Based on physiological metabolite measurements made for human erythrocytes, the activity of glutamate cysteine ligase was determined. There are many possible ways for substrates to bind to an active site of the studied enzyme, but, only the mechanism by which primary binding to ATP can occur makes it possible to obtain the catalytic rate value similar to that of the experimentally measured glutamatecysteine ligase activity relative to physiological concentrations of substrates. In other cases, the values differ by more than one order of magnitude. The performed analysis allows the conclusion that when models for glutathione biosynthesis are constructed in vivo conditions, the ATP concentration and reversible inhibition of glutathione should be taken into account.
Study of the influence of pH on the conformation of a modified aptamer to nucleolin protein
Authors: Gabrusenok P. V , Ramasanoff R. R , Buchelnikov A. S , Sokolov P. A
Published: April 2024

The search for agents for targeted delivery of anticancer drugs remains a crucial challenge for medicine. For this reason, DNA aptamers targeting cancer cell-specific proteins have medical use. At the same time, the additional fine-tuning of aptamer properties to lower affinity of aptamers for target cells that are not surrounding cancerous tissues makes the aptamers promising tools in clinical applications due to reduced immunogenicity and fewer side effects. One of the approaches is to use acidity disruption in cancer cells and tissues. In this work, aptamer AS1411 was modified to increase affinity for nucleolin by attaching a nucleotide sequence to its binding site to create a pH-sensitive linker. UV melting and fluorescence methods were employed to demonstrate that the conformation of the new aptamer depends on pH of the medium.
Two subcompartments of the smooth endoplasmic reticulum in perisynaptic astrocytic processes: ultrastructure and distribution in hippocampal and neocortical synapses
Authors: Shishkova E. A , Rogachevsky V. V
Published: April 2024

Perisynaptic astrocytic processes involved in the tripartite synapse functioning respond to its activation by local depolarization with calcium release from the intracellular stores inside nodes of astrocytic processes and develop local and generalized calcium events. However, based on the first electron microscopy studies a point of view was formed that terminal astrocytic lamellae are devoid of any organelles, including the main astrocytic calcium store - the cisternae of the smooth endoplasmic reticulum. Indeed, analysis of smooth endoplasmic reticulum cisternae could be limited by their weak electron contrast, the studying of astrocytic processes on single sections, and insufficient optical resolution of the equipment used. Here, by using serial section transmission electron microscopy and 3D reconstructions, we analyzed astrocytic processes in murine hippocampal and cortical synapses. As a result of unit membranes contrast enhancement, it was shown for the first time that perisynaptic processes of astrocytes with a morphology of thin branchlets contain two types of smooth endoplasmic reticulum cisternae and microvesicles. Unlike branchlets, membrane organelles inside terminal lamellae were comprised by only short fragments of thin smooth endoplasmic reticulum cister-nae and microvesicles, whose groups tend to be located in close proximity to active zones of the most active synapses. We speculate both on reliability of the alternative methods in electron microscopy while studying astrocytic microenvironment of synapses and structure-function aspects of smooth endoplasmic reticulum cisternae compartmentalization inside the perisynaptic processes of astrocytes.
Theranostics for oncological therapy: results from worldwide research and the paths of development
Authors: Romodin L. A
Published: April 2024

Theranostics is a field of medicine with the aim to establish tools for a specific targeted therapy based on early diagnosis of diseases. This effect is primarily due to targeted delivery of the therapeutic agent to the target cells. The development of a clinically effective theranostic drug will be the greatest medical breakthrough. This paper presents an analytical mini-review of some modern approaches to find a solution to the core of the problems of theranostics for oncological therapy and discusses recent studies on the use of radiopharmaceuticals, that can be diagnostic and therapeutic, and systems for visualization of radiopharmaceuticals by means of magnetic resonance imaging for therapy of cancerous tumors. Information is given on application of various systems using fluorescent agents such as anti-Stokes fluorophores, the signal from which is well observed, compared to other fluorescent substances, on a background of the reflected irradiance from tissues surrounding cancer cells. This paper also presents details on the comparative use of classical chemotherapeutic agents and promising drugs developed on the basis of natural substances, for example, sulforaphane and cytochrome c, that have lower toxicity.
Effects of DNA-binding ligands from dimeric bisbenzimidazoles series DBA(n) and DBPA( n) in combination with γ-radiation on epithelial-mesenchymal transition and pool size of MCF-7 breast cancer stem cells
Authors: Churiukina K. A , Matchuk O. N , Kaprin A. D , Ivanov S. A , Koval V. S , Arutyunyan A. F , Zhuze A. L , Zamulaeva I. A
Published: April 2024

Radiation therapy is one of the main treatments for malignant neoplasms, including breast cancer. However, it is known, that radiation therapy can lead to an increase in the number of cancer stem cells, which are resistant to traditional antitumor effects, and are believed to be responsible for the development of recurrences and metastases. Therefore, the development of cancer stem cells elimination means is of considerable interest, especially in combination with ionizing radiation. The effects of single and combined exposure to new series of minor-groove DNA ligands - dimeric bisbenzimidazoles - DBA(n) and DBPA(n) (where n is the number of methylene groups between two bisbenzimidazole blocks) and Y-radiation on human Breast cancer cells were studied in our work for MCF-7 line in vitro. Compounds with maximum cytotoxic effect and cell binding were selected, and then the effects of the latter on the CD44+CD24-/low cancer stem cells population and radiation-induced epithelial-mesenchymal transition were studied by the criterion of vimentin expression. An increase in the expression level of this protein and simultaneously in the relative number of cancer stem cells after a single exposure of Y-radiation at a dose of 4 Gy were shown. DBPA(1,4) in combination with irradiation blocked the radiation-induced vimentin expression and decreased the relative number of cancer stem cells by 1.7 and 4.1 times compared with irradiation (p = 0.041 and p = 0.005), respectively. At the same time, the absolute number of cancer stem cells decreased by 2.8 and 12.0 times compared to irradiation (p = 0.029 and p = 0.004), respectively. In contrast, DBA(5,7) by itself or in combination with Y-irradiation increased the level of vimentin expression and the same compounds when combined with irradiation increased the relative number of cancer stem cells by 3.1 and 3.6 times (p = 0.006 and p = 0.005), respectively, compared with irradiation. The absolute number of cancer stem cells increased by 2.2 and 1.5 times (p = 0.017 and p = 0.032), respectively. The data obtained show a close relationship between epithelial-mesenchymal transition and formation of the cancer stem cells pool after radiation exposure, and also indicate the prospects for further study of DBPA(1,4) as a means of cancer stem cells elimination under in vivo conditions.
Effects of ionizing radiation on radio sensitivity of cell nuclei of wheat seedlings
Authors: Minasbekyan L. A , Avagyan I. A
Published: April 2024

Effects of the 50 Gy and 100 Gy doses of Y-irradiation on radiosensitivity of cell nuclei of soft dwarf wheat seedlings were studied. Changes in the biochemical composition of the nuclear fractions of seedlings of wheat seeds exposed to gamma-irradiation were determined. After exposure to ionizing radiation, total protein and nucleic acids levels appeared to be greater in the soluble nuclear fraction and the nuclear membrane-associated DNA content and proteins increased. It was also found that the value of the dzeta-potential of isolated nuclei of seedlings of irradiated seeds decreased in a static electric field. Changes in the surface charge of the nucleus lead to a violation of its functional activity, since the surface charge of the nuclei is necessary for the normal functioning and regulation of the nuclear-cytoplasmic transport of macromolecules. Exposure to radiation causes destruction of ionogenic groups of molecules of the nuclear membrane, leading to a decrease in the electronegativity of the nuclei, which, in turn, entails a change in the functional activity of the nucleus. The results obtained show that changes in electronegativity and in the content of nuclear fractions are directly dependent on the dose of ionizing radiation. It can be concluded that Y-irradiation in a range from 50 to 100 Gy had beneficial effects on metabolic and proliferative activities of soft wheat cells.
Influence of the microenvironment dynamics of tryptophan on its fluorescence parameters at different temperatures
Authors: Gorokhov V. V , Knox P. P , Korvatovsky B. N , Goryachev S. N , Paschenko V. Z , Rubin A. B
Published: April 2024

The temperature dependences of the fast and slow fluorescence decay components of aqueous solution of tryptophan molecules after freezing to -170°C - 20°C under actinic light and in the dark were investigated. A model of the direct and reverse electronic transitions from an excited state to the ground state and to the state with charge transfer for a tryptophan molecule was used to perform quantitative analysis. Three main spectral regions of tryptophan fluorescence are shown, they differ in the behavior of the temperature dependences depicted for the rates of transition from the excited state of tryptophan to the state with charge transfer. It has been shown that the dynamics of the hydrogen bonded system plays a key role in this transition. The system of hydrogen bonding determines the nonlinear nature in tryptophan fluorescence in the selected spectral regions. The non-linear behavior of the fluorescence lifetime and fluorescence spectra with temperature change is determined by the type of the interaction of tryptophan with water and ice. It has been found that temperature rearrangements play a critical role in hydrogen bonding structure of H2O 2 that surrounds a tryptophan molecule in the excited state.
The effect of the antioxidant system resveratrol - iron sulfonitrosyl complex sodium-μ2-dithiosulphate-tetrarntrosyl diferrate tetrahydrate on the mitochondria of pea germ epicotyls in vitro
Authors: Gerasimov N. Yu , Nevrova O. V , Zhigacheva I. V , Generozova I. P , Goloshchapov A. N
Published: April 2024

The interaction of antioxidants - plant polyphenol resveratrol and nitric oxide donor, iron-sulfo-nitrosyl complex with thiosulfate Na2[Fe2(S2O3)2(N0)4]24H2O (TNIC-thio), and their combined action on mitochondria of pea germ epicotyls was studied in vitro. The antioxidant activity of resveratrol (10-6 M), partially compensated the toxic effect of TNIC-thio at high concentration, that is most likely associated with the exhibition of the prooxidant properties of high concentrations of the nitric oxide donor. The effect of resveratrol at concentrations 10-6 M and 10-8 M on the membranes of mitochondria isolated from the pea germ epicotyls treated with 10-8 M TNIC-thio led to coordinations failure in the system of regulation of lipid peroxidation of membranes, that caused antioxidant stress. The action of resveratrol at the dose of 240-5 M had a dual character and practically did not effect on the structural state of mitochondrial membranes.
Spectrophotometric determination of sodium-copper chlorophyllin level in lymphocytes
Authors: Romodin L. A
Published: April 2024

This study raises the question of whether it is possible to determine the appearance of sodium-copper chlorophyllin in lymphocytes. To answer this question, the content of chlorophyllin was determined in lymphocyte lysate previously incubated in a medium containing 300 uM of copper chlorophyllin. Significant amounts of chlorophyllin were observed in the lysate, thus, suggesting that chlorophyllin is able to enter cells. However, the question remains as to whether chlorophyllin can pass through the nuclear membrane. Based on our own data and information obtained from the scientific literature, it can be concluded that the passage of chlorophyllin through the nuclear membrane happens at a much slower rate than through the plasmalemma.
Differences in responses of premotor interneurons to serotonin and 5-hydroxytryptophan, a precursor for serotonin synthesis, in naive and trained snails
Authors: Bogodvid T. K , Andrianov V. V , Muranova L. N , Gainutdinov Kh. L
Published: April 2024

This study investigated the responses of premotor interneurons LPa3 and RPa3 of the snails to applications of serotonin and 5-hydroxytryptophan (5-HTP), a precursor for serotonin synthesis, as ingredients of the broth that bathes the central nervous system of naive snails and snails after the formation of long-term sensitization. Measurements of the electrical characteristics have shown that a membrane potential of interneurons LPa3 and RPa3 in naive snails was significantly depolarized (3.7 mV) in the presence of serotonin, while the threshold potential was increased (unsupported hypothesis). The similar pattern was observed in the presence of 5-hydroxytryptophan: true depolarization to 3.1 mV occurred in interneurons until reaching the unreliable rise in the threshold potential inducing an action potential. It was found that application of serotonin causes a significant decrease in the membrane potential of interneurons LPa3 and RPa3 of trained snails (depolarization to 4.6 mV) and the unreliable increase in the threshold potential of premotor interneurons (0.9 mV). In contrast, application of 5-hydroxytryptophan causes an unreliable increase (2.5 mV) of the membrane potential and also an unreliable increase (0.8 mV) in the threshold potential.
The XXI century: consciousness and the brain
Authors: Ivanitskii G. R
Published: April 2024

The most remarkable result of human creativity in the XXI century is the development of creative android robots equipped with artificial intelligence. The rate of progress made in developing these robots is so fast that it will soon be impossible to distinguish robots from human beings in appearance features. Searching for the difference between humans and robots (tests by A. Turing, J. Searle, etc.) gives rise to a host of difficult questions concerning the common understanding of the definition of the term “consciousness”. However, the similarities between humans and robots can lead to a logical error, i.e., to substitution of actual reality for virtual reality.
Cellular response to exposure to ionizing radiation and light in the presence of a photosensitizer
Authors: Akulinichev S. V , Glukhov S. I , Efremenko A. V , Kokontsev D. A , Kuznetsova E. A , Martynova V. V , Feofanov A. V , Yakovlev I. A
Published: April 2024

This study has been conducted to investigate the effects of X-ray irradiation in combination with photodynamic therapy on human lung adenocarcinoma cell line A549 used as a lung cancer model. It has been established that the concomitant use of these two types of radiation leads to much lower survival rate of tumor cells than that observed after the sequential use of these types of radiation or exposure to each type of radiation measured separately. For different combinations of the two mentioned types of radiation, the mRNA expression levels of some genes involved in cell cycle regulation (p21, DINOL), apoptosis (BAX, PUMA), and DNA repair (PARP1, OGG1, Rad51, Lig4) were determined in cells. The highest level of expression after exposure to different combinations of radiation was observed for the lncRNA DINOL gene. The increased expression of the BAX and PUMA genes indicates the development of apoptosis. The results obtained confirm that there is synergism in X-ray radiation and photodynamic therapy due to the concomitant use of these types of radiation.
Cell cycle parameters and ornithine decarboxylase activity in the red bone marrow of hibernating ground squirrels Urocitellus undulatus
Authors: Aksyonova G. E , Logvinovich O. S , Afanasyev V. N , Lizorkina K. I
Published: April 2024

During the hibernation season, the values for the parameters of the cell cycle of red bone marrow cells in the hibernating ground squirrels Urocitellus undulatus, when they return to an active-like state between periods of torpor and interbout arousal, do not differ from those observed in summer-active animals. In animals that enter a state of torpor, the cumulative percentage of cells in the resting phase (G0 phase) and pre-synthesis phase (G1 phase) increased from 71.8 to 76.0%, the percentage of cells in the synthesis phase (S phase) decreased from 19.3 to 15.3% compared to those animals that return to an active-like state between periods of torpor and interbout arousal. The cumulative percentage of cells in the post DNA synthesis phase (G2 phase) and mitosis (M) does not change, but (G2 + M)/S ratio increases. When animals enter a state of torpor, changes in parameter values are observed when the animal’s body temperature drops below 25°C, this effect refers to a system whose thermal relaxation time is a nonmonotonic function of the initial temperature. The activity of the key enzyme of polyamine synthesis ornithine decarboxylase, a marker of cell activation and proliferation during interbout arousal does not significantly differ from that observed in summer-active animals; the enzymatic activity decreases sharply, when animals decrease their body temperature below 25°C and enter a state of torpor, and this activity remains at a low level during hibernation and arousal until body temperature reaches 30°C. The role of changes in the parameter values associated with proliferative activity in adaptation of hematopoietic tissue during hibernation of the Yakutian ground squirrel is discussed.
Structural and functional assessment of the condition of wound bed using microwave dielectrometry and laser doppler flowmetry
Authors: Martusevich A. K , Surovegina A. V , Nazarov V. V , Fedotova A. S
Published: April 2024

The aim of the work was to develop and test a combined method for assessing the structural and functional features of the burn wound and periwound area with the use of microwave dielectrometry and Dopplerometry. The study was performed on twenty Wistar rats, thermal injuries from contact were created on each rat, and ten healthy animals. The assessment of the wound condition was performed 24 and 72 hours after burn injury. The study of the dielectric properties of tissues was carried out using a hardware and software complex for near-field resonant microwave sensing. From the results of our studies, it can be concluded that in the early post-injury period (within the first days), a sharp coordinated decrease in the intensity of microcirculation and dielectric permittivity is observed in the wound tissues, gradually and partially restored by the end of the third day after burning. The increased microcirculatory blood flow to the periwound area, leading to an increase in the degree of tissue hydration was observed, and as a consequence, the values of these two indices became higher. In addition, it has been shown that during thermal trauma, a regulatory imbalance of factors providing capillary blood flow around a burn wound area and surrounding tissues is formed, which is compensatory in nature and, in the absence of adequate correction, contributes to the inhibition of regeneration processes. Thus, the combination of the methods used in this study may potentially provide more specific information for a description of the structural and functional features of the analyzed tissue and their dynamics. This is clearly shown by the example of an experimental burn wound.
A thermodynamic model for the formation of protein aggregates on a matrix
Authors: Vasilenko E. O , Kozin S. A , Mitkevich V. A , Buchelnikov A. S , Nechipurenko Yu. D
Published: April 2024

The development of many neurodegenerative diseases is associated with the formation of pathological protein aggregates. In some cases, these aggregates can be formed by multilayer adsorption of ligands on a matrix, for example, the set of membrane protein receptors. The paper proposes a thermodynamic model describing the formation of linear aggregates in which ligands can be stacked. The cases when these stacks consist of complexes of one or two different types are considered. The developed model can be applied to the study of pathological aggregation of proteins of different nature, primarily beta-amyloid and its isoforms. The mean, variance and entropy of the theoretical distributions of aggregate sizes are calculated. A comparison with other theoretical models of the formation of amyloid aggregates is made.