bluuebunny/crossref_metadata_2025 huggingface dataset:
EVOLUTION OF METEOROID STREAMS ORIGINATING FROM NEA COLLISIONS
Authors: Zolotarev R. V. , Shustov B. M.
Published: April 2024

In this work we study formation and evolution of meteoroid streams originating from the collisions of near Earth asteroids (NEA) with objects of the Main Asteroid belt (MAB). Such a collision scenario is considered more probable compared to collisions between NEAs, since many NEAs, by virtue of their origin, cross the MAB region, where the number density of objects is significant compared to the inner regions of the Solar System. Meteoroid streams originating from collisions have a number of differences from the streams of cometary origin, both in terms of the formation and the evolution. In this paper, estimates are obtained for the meteoroid formation rate as a result of NEA collisions with MAB asteroids. On the basis of high-velocity collisions models and the DART experiment data, possible particle size and velocity distributions are obtained. We made numerical simulation taking into account gravitational perturbations and radiation forces and the influence of the initial velocity on the evolution was studied. An analysis was made of the rate of dust and meteoroids production, taking into account the distribution of the current population of the NEA, and it was concluded that the rates of influx of meteoroids of asteroid and cometary origin (in terms of mass) can be quite comparable.
ON THE POSSIBILITY OF ESTIMATION OF THE ORBIT ECCENTRICITY OF A BINARY SYSTEM WITH AN EXOPLANET USING A TRANSIT LIGHT CURVE
Authors: Bekesov E. V. , Abubekerov M. K. , Gostev N. Yu. , Cherepashchuk A. M.
Published: April 2024

Working with both simulated and observed transit light curves, we studied a possibility of determining an orbital eccentricity of a binary star system with an exoplanet. It is shown that determining an exact eccentricity value from transit light curves is possible if a longitude of a periastron is known. In the absence of information about the longitude of periastron, analysis of the transit light curve makes it possible to impose restrictions on orbital eccentricity values. The influence of uncertainty in the orbital eccentricity on the accuracy of determination of other parameters of the system (a radius of the star, a radius of the planet, orbit inclination, and limb darkening coefficient) has been studied.
INTERACTION OF THE EXOPLANET HAT–P–11b WITH THE STELLAR WIND
Authors: Belenkaya E. S.
Published: April 2024

This article discusses the possibility of the existence of a magnetodisk around the exoplanet HAT–P–11b. We used the available observational data to determine the properties of this exoplanet and the stellar wind passing by it, and obtained a rough estimate of the planetary magnetospheric scale. Our estimate was compared with the published results of calculations by the Particle-In-Cell method in a three-dimensional electromagnetic relativistic collisionless model of the magnetosphere. The resulting discrepancy between the magnetospheric scales obtained by these two methods is discussed, and its possible interpretation is proposed.
SCALE-INVARIANT MODE IN COLLISIONLESS SPHERICAL STELLAR SYSTEMS
Authors: Polyachenko E. V. , Shukhman I. G.
Published: April 2024

An analytical solution of the perturbed equations is obtained, which exists in all ergodic models of collisionless spherical stellar systems with a single length parameter. This solution corresponds to variations of this parameter, that is, the stretching/contraction of the sphere keeping the total mass constant. During the process, the system remains in an equilibrium state. The simplicity of the solution makes it possible to explicitly give expressions for the distribution function, potential, and density in all orders of perturbation theory. This, in turn, helps to clarify the concept of perturbation energy, which, being a second-order magnitude in amplitude, cannot be calculated in linear theory. The expression for the 2nd-order perturbation energy does not match the well-known quadratic form for perturbation energy derived from 1st-order perturbations in linear theory. However, both of these energies are integrals of motion and differ only by a constant. The obtained solution can be used to control the correctness of codes and the accuracy of calculations in the numerical study of collisionless stellar models.
NO BIOMARKER: TRANSMISSION AND EMISSION METHODS FOR ITS POTENTIAL DETECTION IN EXOPLANET ATMOSPHERES WITH SPEKTR-UF (WSO-UV)
Authors: Tsurikov G. N. , Bisikalo D. V.
Published: April 2024

Among all habitability factors for terrestrial exoplanets, one of the most important is the presence of a secondary N2–O2 dominant atmosphere in an exoplanet. This factor can potentially indicate the already existing geological and biological processes on the exoplanet. Meanwhile, direct characterization of the N2–O2 atmospheres of terrestrial exoplanets is a difficult observational task. There are only a few indicators (molecules) of such an atmosphere, among which one can single out a potential biomarker – a molecule of nitric oxide NO. The strongest spectral features of this molecule in the ultraviolet range are γ-bands (203–248 nm). An important role in the search for potential biomarkers on exoplanets, including the registration of NO γ‑bands, can be played by planned for the launch WSO-UV space observatory. In the paper estimates of the possibility of detecting the transmission of light in γ-bands in the atmospheres of exoplanets with this observatory are presented. The methods of emission and transmission spectroscopy are compared as applied to the detection of NO. Based on the results of this work, it is shown that there is a potential possibility of detecting a transmission signal in the NO γ-bands in the atmospheres of nearby exoplanets (10 pc) using the LSS spectrograph of the WSO-UV observatory. At the same time, the imposed restrictions for the registration of this signal on more distant exoplanets are presented.
THE FORMATION AND THE EVOLUTION OF LARGE-SCALE VORTEX STRUCTURES IN STELLAR ACCRETION DISKS
Authors: Livenets Z. D. , Lugovsky A. Yu.
Published: April 2024

Explaining the causes of angular momentum transfer in accretion stellar disks is an important astrophysical problem, since it is the process that determines the rate of accretion of matter onto the central gravitating body. Previously, within the framework of a two-dimensional approach, it was shown that the introduction of small perturbations into the flow of disk matter leads to the appearance of shear instability. This process is accompanied by the development of large-scale vortex structures. Their movement and evolution lead to a redistribution of angular momentum in the accretion disk. The action of the described mechanism was previously studied numerically only within a two-dimensional approximation, so the goal of the current work is to carry out full-scale three-dimensional modeling. The processes under study are described within the framework of the system of equations of ideal gas dynamics. The article briefly describes the method for their numerical integration, which is based on a conservative finite-difference scheme and the solution of the Riemann problem. The initial data is a stationary toroidal gas state surrounded by a matter with low density and pressure. At the next step, small perturbations of one of the gas-dynamic variables are introduced. The modeling and analysis of the results of numerical calculations show the emergence of vortex structures in the shear flow of a three-dimensional accretion disk. Their movement is accompanied by a redistribution of matter and angular momentum in the volume of the disk, leading to accretion of matter onto the central body.
LUMINOSITY OUTBURSTS IN INTERACTING PROTOPLANETARY SYSTEMS
Authors: Skliarevskii A. M. , Vorobyov E. I.
Published: April 2024

FU Orionis type objects (fuors) are characterized by rapid (tens to hundreds years) episodic outbursts, during which the luminosity increases by orders of magnitude. One of the possible causes of such events is a close encounter between stars and protoplanetary disks. Numerical simulations show that the fuor-like outburst ignition requires a very close encounter ranging from a few to a few tens of au. In contrast, the observed stellar objects in fuor binaries are usually hundreds of au apart. Simple mathematical estimates show that if such a close approach took place, the binary stellar components would have an unrealistic relative velocity, at least an order of magnitude greater than the observed velocity dispersion in young stellar clusters. Thus, the bursts are either triggered with a certain delay after passage of the periastron or their ignition does not necessary require a close encounter and hence the outburst is not caused by the primordial gravitational perturbation of the protoplanetary disk. In this work, an encounter of a star surrounded by a protoplanetary disk with a diskless external stellar object was modeled using numerical hydrodynamics simulations. We showed that even fly-bys with a relatively large periastron (at least 500 au) can result in fuor-like outbursts. Moreover, the delay between the periastron passage and the burst ignition can reach several kyr. It was shown for the first time by means of numerical modeling that the perturbation of the disk caused by the external object can trigger a cascade process, which includes the development of the thermal instability in the innermost disk followed by the magneto-rotational instability ignition. Because of the sequential development of these instabilities, the rapid increase in the accretion rate occurs, resulting in the luminosity increase by more than two orders of ma-gnitude.
PECULIAR SPECTRUM OF THE WATER MASER IN THE DARK NEBULA MSXDCG24.33+011(G24.33+014)
Authors: Val’tts I. E.
Published: April 2024

Giant molecular clouds (GMC) in our and other galaxies and small dense molecular clouds inside the Galaxy (IRDC) form cores due to gravitational instability, in which massive stars and clusters of low-mass stars arise. The high background of infrared radiation inside the Galaxy creates advantages in favor of IRDCs in the study of star formation processes and accompanying phenomena such as accretion, the appearance of HII regions, bipolar outflows, and others that cause various responses in their molecular composition. As a part of studying the evolutionary state in the cloud IRDC MSXDCG24.33+011 (the alternative name is G24.33+014), observations of the water vapor maser were made. On November 28 (2022) during the observations using the RT-22 of the Pushchino Radio Astronomy Observatory, the H2O maser detail at the velocity of \({{V}_{{{\text{LSR}}}}} = 103.15\) km/s with the linewidth of 0.52 km/s was detected. Peak flux of 49.5(\( \pm 6\)) Jy was recorded. This detail was not detected on RT-22 in the PRAO on July 5 (2022) and has not been seen before by other researchers.
Conformational aspects in the formation of structures of the backbone of polypeptide chains in proteins. Relationship between conformational stability/lability and β-turns
Authors: Torshin Yu. Yu , Filatov I. V , Batyanovskii A. V , Smirnov K. V , Anashkina A. A , Esipova N. G , Tumanyan V. G
Published: April 2024

To assess the nature of the relationship between the integral conformational stability of tetrapeptides and the main types of β-turns (which are also tetrapeptides), calculations were performed using spectrum diagrams and asymmetry in the distribution of conformationally stable and unstable tetrapeptides. It was shown that type I', II, and II' β-turns are comprised of predominantly conformationally labile peptides, that is consistent with the predetermined nature of their structure as described earlier. As previously shown in our study, in this case the conformation is imposed by external conditions (namely the cycle closuring) and the prevalence of conformationally labile peptides facilitates the formation of the structure by virtue of external factors. Type I β-turn is an exception: peptides with different conformational lability are fairly evenly distributed. Most likely, this indicates that the formation of the type I β-turn is not predetermined.
Model of lipid diffusion in cytoplasmic membranes
Authors: Mokrushnikov P. V , Rudyak V. Ya
Published: April 2024

An analytical model of lateral lipid diffusion in heterogeneous native cytoplasmic membranes is presented. The Fourier transform method was used to solve the diffusion equation for the coordinate distribution function of lipids in a periodically inhomogeneous membrane, in which the diffusion coefficient is described by a harmonic function of the coordinates. It is shown that advection and diffusion are present in membrane. The model explains different types of lipid diffusion in membrane observed previously in experiments as a result of structural transitions of periodically located fixed protein-lipid domains associated with the spectrin-actin-ankyrin network. If these domains are the same, then super- and subdiffusion can be seen in experiments, when the mean square displacement of lipids depends non-linearly on time, and their average displacement is zero. Drift during advection was less than the chaotic Brownian displacement of lipids, advection was not observed in the experiment. When not all membrane proteins associated with the spectrin-actin-ankyrin network undergo conformational change in the same way upon ligand binding, two periodic sublattices of inhomogeneities arise in the membrane from fixed protein-lipid domains around membrane proteins associated with the cytoskeleton and nested in one another. In this case, hop diffusion can be found in experiments, when periods of nonlinear diffusion of molecules are replaced by periods of advection-diffusion, in which the average displacement of molecules is not zero. Advection is local in nature and occurs near individual protein-lipid domains. In the presented work, criteria are analytically obtained under which hop diffusion is experimentally observed in a periodically inhomogeneous membrane.
Local optical tomography of a nerve cell
Authors: Levin G. G , Samoilenko A. A , Kazakova T. A , Marakutsa T. A , Maksimov G. V
Published: April 2024

The presented modification of the method of local optical tomography makes it possible to study the dynamic processes of subcellular structures of native nerve cells. The advantage of this approach is that it is possible to analyze the dynamics of the distribution of neuron structures at a point or area of interest inside the cell without performing a complete reconstruction of the cell image. It has been proved that it becomes possible to determine the dimensions, the cell area of interest, and the coordinates of subcellular structures for further study of their dynamics. In this modification, the method of local tomography could be used to study both cells and cellular structures, because it is not necessary to probe a full field of view. Local probing of the region of interest during the functioning of the nerve cell will, firstly, reduce the time of data recording for obtaining local tomograms, and, secondly, provide the opportunity to explore the dynamics of several regions inside the cell at the same time.
Mechanisms involved in regulation of blood coagulation: history of research and perspectives
Authors: Nechipurenko D. Y , Panteleev M. A , Sinauridze E. I , Troyanova K. S , Megalinsky A. D , Podoplelova N. A , Shibeko A. M , Balandina A. N , Koltsova E. V
Published: April 2024

Blood clotting is the most important physiological response in the body to disruption to vascular structure or vessel wall abnormalities. This process is non-stationary, involving many not fully established mechanisms of spatial regulation, and an understanding of this process is essential for the prevention of a large number of life-threatening conditions. This review is focused on investigations into the research of blood clotting processes by a team of biophysicists, alumni and employees of the Biophysics Department of the Faculty of Physics, Lomonosov Moscow State University, who created one of the leading Russian scientific schools for experimental and theoretical approaches to the study of the hemostasis system. The review describes the main directions of research, which included many diverse aspects of the problem - from the development of theoretical models of blood coagulation to the development and clinical studies of new methods for assessing the state of the hemostasis system.
Paracrine effects of stem cell conditioned medium on production of oxygen reactive species in blood neutrophils in acetaminophen-induced liver failure
Authors: Temnov A. A , Sklifas A. N , Zhalimov V. K , Sharapov M. G , Fadeev R. S , Kobyakova M. I , Kukushkin N. I , Rogov K. A
Published: April 2024

The current study examined the effects of mesenchymal stem cells-derived conditioned medium on the severity of systemic inflammatory response induced by the administration of acetaminophen, as well as its long-term effects on hepatic tissues. A conditioned medium fraction ˂30 кDа showed maximum protective effect. Proteins of this fraction reduce the degree of systemic inflammatory response and liver tissue fibrosis long after the toxin administration. Liver tissues from experimental animals were examined, and a correlation between the reduction of granulocytic infiltration scoring and the degree hepatic parenchymal necrosis was demonstrated (confirmed by the cytolytic enzyme level). The ˂30 кDа fraction increased the spontaneous but decreased phobrol-12-myristate-13-acetate-induced intracellular production of reactive oxygen species. Results from this study show that the level of macrophage migration inhibitory factor and expression of thioredoxin significantly increase as compared to controls during increased spontaneous production of reactive oxygen species in neutrophils.
Epr study of the generation of short-lived reactive oxygen species in rat heart homogenate
Authors: Timoshin A. A , Lakomkin V. L , Abramov A. A , Ruuge E. K
Published: April 2024

The aim of the present study was to investigate the protective effects of a mitochondrial-targeted antioxidant such as plastomitin through ROS hypergeneration in animals. The average rate of the generation of highly reactive oxygen radicals during oxidative stress, induced by doxorubicin injection in rats and a protective impact of plastomitin use were investigated. The experiments were carried out with rat heart tissue homogenates using EPR spectroscopy. It was found that in case of doxorubicin injection in rats, there is a significant 26% increase in the rate of short-lived reactive oxygen species generation in the homogenate but when doxorubicin and plastomitin were used in combination, this effect was greatly suppressed.
Comparison of the dynamics of DNA damage in blood leukocytes and survival of mice after total body irradiation with Bragg peak carbon ions or x-rays
Authors: Kuznetsova E. A , Rozanova O. M , Smirnova E. N , Glukhov S. I , Sirota T. V , Belyakova T. A , Sirota N. P
Published: April 2024

This study has determined a survival rate of mice irradiated with accelerated carbon ions (450 MeV/nucleon) in the Bragg peak or X-ray at a dose of 6.5 Gy, using the comet assay. Levels of DNA damage (%TDNA) in blood leukocytes from mice were measured 1 day before, 1-23 days after exposure to carbon ions and 1-28 days after exposure to X-ray radiation at the same dose. According to survival and % TDNA parameters, it was found that a damaging effect of carbon ions is greater than that of X-rays and substantial variations in % TDNA, which occur in individual animals, could appear to cause individual differences in the development of genome instability in the long term. It is assumed that a higher % TDNA in leukocytes after carbon ion exposure compared to that of X-rays, a wide range of variations and asynchronous changes in individuals in the post-irradiation period are associated with the induction of clustered DNA damages and mitochondrial dysfunction, and are also due to genetic and epigenetic factors. The results obtained point to the need to assess the state of blood leukocytes in animals with a heterogeneous genetic background using the comet assay before irradiation in order to form a group with similar %TDNA values. The revealed differences in individual laboratory animals require further study in order to improve animal models in the light of the development of personalized biomedicine.
Dynamics of temperature and body weight in irradiated mice: the dose-effect and time-effect relationships
Authors: Zrilova Yu. A , Nikitenko O. V , Bychkova T. M , Parfenova I. M , Karaulova T. A , Ivanov A. A
Published: April 2024

In an experiment on outbred male ICR CD-1 mice irradiated at a wide range of doses of gamma irradiation 60Co from 7.4 to 9.4 Gy with a 30-day survival rate from 100 to 5%, the dose-effect and time-effect relationships in relation to animals’ temperature and body mass index during acute radiation sickness were studied. The latent phase of acute radiation sickness is already related to a decrease in body temperature, which is determined using a remote infrared thermometer, in presence of body weight loss. A maximum dose-dependent fall in body temperature was observed in the critical phase of acute radiation sickness, when animals die in large numbers. In the recovery phase, body temperature returned to normal with subsequent body weight gain. Body temperature of irradiated mice is considered as an important criterion for their asthenia and can be used both in theoretical and applied studies.
Investigation of changes in lung volume caused by high-intensity acoustic oscillations at the resonant frequency of the respiratory system
Authors: Dragan S. P , Kezik V. I , Bogomolov A. V , Drozdov S. V
Published: April 2024

This paper presents an experimentally determined dependency of an increase in the volume of the lungs of laboratory animals on the level of high-intensity low-frequency sound at the resonant frequency of their respiratory system. Experiments were conducted on 16 rabbits. A modified two-microphone technique was used for the measurement of the resonant frequency of the respiratory system in the frequency range from 5 Hz to 100 Hz for a step in frequency of 3 Hz. Having determined the resonant frequency, a tone signal was delivered to the lungs at this frequency with an adjustable sound amplitude from 120 to 138 dB. The measurement results indicate that the resonant frequencies of the respiratory system in rabbits decreased by an average of 13%, that corresponds to an increase in lung volume by 33% due to the opening of the alveolar oxygen reserve. The observed phenomenon relating to lung volume increase under the influence of a stimulating high-intensity sound signal at a resonant frequency can be used to enhance the effectiveness of bioacoustic stimulation of human lungs in order to increase the volume of the respiratory system.
Therapeutic effects of high-dose inhaled nitric oxide gas against post-covid syndrome, diabetes or AIDS
Authors: Vanin A. F , Pekshev A. V , Pechyonkin E. V , Vagapov A. B , Sharapov N. A
Published: April 2024

A therapeutic effect of high-dose nitric oxide gas inhalation (more than 1000 ppm) on patients with post-COVID syndrome, diabetes or AIDS is shown. It has been proposed that nitrosonium cations (NO+), derivatives of nitric oxide gas, the emergence of which in the blood or organ tissues of patients is related to disproportion reaction of NO molecules, forming a co-ordinate bond with the Fe2+ion, carried by transferrin or entered into the labile (free) iron pool may act as a therapeutic agent. It is quite probable that treatment of HIV infection (as well as the earlier revealed effect of NO gas on the patients with COVID-19) could be provided by the effects of S-nitrosylation of NO+ cations on thiol groups of viral proteases and host proteins. A beneficial effect of NO+ cations which emerged in the reaction of NO gas molecules in patients with post-COVID syndrome or diabetes can be also associated with an inhibitory effect of these cations on the thiol-containig proteins that are involved in apoptosis.
On the possibility of non-invasive study of the peripheral mechanisms of autonomous regulation of the human cardiovascular system
Authors: Nesterov V. P , Burdygin A. I , Ivanov K. B , Korotkov S. M , Sobol K. V , Soroko S. I , Shemarova I. V
Published: April 2024

The aim of this study was to evaluate the possibility of using the developed method of arterial piezopulsometry for non-invasive study of peculiarities of the functioning of peripheral mechanisms of autonomic regulation of the cardiovascular system in patients of different age and health state. Study emphasizes the importance of determining the variability of the parameters of blood pressure pulse waves as a measure of assessing the participation and role of the components of the neuroendocrine (sympatho-adrenal) efferent link in the formation of a fast and well-regulated response of systemic hemodynamics, using myocytes of the left ventricle of the heart as effectors. This paper discusses the possibility and expediency of personalized use of the arterial piezopulsometry method for pulsometric diagnostics of the functional state and nature of autonomic regulation of the functions of cardiovascular system in patients in order to be able to detect earlier pathological conditions and disorders of peripheral mechanisms that ensure adequate blood supply in humans.
Alanine: from the usual to the unexpected
Authors: Tumanyan V. G , Anashkina A. A , Filatov I. V , Smirnov K. V , Torshin I. Yu , Esipova N. G
Published: April 2024

Data from the experiments provides a possibility to talk about anomalously large contribution of alanine to the stability of an alpha-helix and other protein conformations. Independent data (and also experimental ones) suggest that alanine plays an especially big role in stabilization of the alpha-helix. This can be seen through the positive contribution of alanine both to the entropy of the system and to the enthalpy. The high contribution of alanine to the enthalpy of formation of the alpha helix contradicts the generally accepted view that the entropy should decrease during the formation of regular structures in proteins. Among three types of helices in proteins, alanine stabilizes two secondary structures: the alpha helix and the left helix of polyproline II, and in the case of fibrillar proteins, alanine also stabilizes the beta sheet. The stabilizing effect of alanine on the alpha helix structure extends to both natively unfolded proteins and alpha helix-support conjugates. Thus, it is no exaggeration to say that formation of secondary structure relies on alanine. The revealed contradictions are of paradoxical nature and yet there is no interpretation of the above-mentioned findings (first of all, substantiation of the contribution of alanine to the enthalpy of fusion in terms of fundamental physics) so far to resolve them. Meanwhile, the data and comments presented in this work hold out the promise of progress in resolving the revealed contradictions.
Genome-wide association study of copy number variation in flax through the lens of genome integrity
Authors: Duk M. A , Kanapin A. A , Rozhmina T. A , Samsonova A. A
Published: April 2024

Classical methods for identification of genetic variants associated with certain macroscopic phenotypic traits are, as a rule, limited to analyses of single nucleotide polymorphisms. Copy number variations, and more broadly structural variants may provide a plethora of useful information due to the magnitude of the changes they induce. However, their use in genome-wide association studies is seriously limited mostly due to the uncertainties in their discovery (i.e., failure to resolve an event with nucleotide resolution) by computational algorithms from genomic data. Nevertheless, in certain cases, such analyses are possible and may still yield valuable results. Our recent work has revealed genetic variants (single nucleotide polymorphisms) possibly related to phenotypic traits determining fibre quality. Here, we decided to extend the analyses to structural variants, namely copy number variations. Importantly, we use a novel high-coverage dataset allowing for accurate prediction of copy number variations. Overall, we compiled a list of 41 candidate genes associated with five quantitative phenotypic traits. Furthermore, the genome stability metric developed earlier facilitated stratification of copy number variant loci with regard to their stability. On the whole, our analyses suggest that the genomic regions less resilient to external and internal stresses are more susceptible to changes associated with the studied phenotypic traits.
Possibilities of Studying Biological Objects on a Pulsed Reactor
Authors: Vlasov A. V , Ryzhykau Yu. L , Manukhov I. V , Bazhenov S. V , Kurakin S. A , Murugova T. N , Ivankov A. I , Skoy V. V , Rogachev A. V , Verteletskiy D. P , Islamov A. Kh , Kucherka N. , Gordeliy V. I , Kuklin A. I
Published: April 2024

Small-angle scattering makes it possible to solve structural biology problems without specific sample preparation, which is typical for methods such as X-ray diffraction of protein crystals or cryo-electron microscopy of proteins. In our review, it is shown how to use small-angle scattering to address biological problems. The use of small-angle scattering is suggested for applications as a tool to control the quality of the assembly of proteins and protein complexes and to test the identity of the structural organization of biological objects in the native state and in prepared samples before measurements by X-ray diffraction or cryo-electron microscopy. This work demonstrates the possibilities of the small-angle neutron scattering spectrometer YuMO based on the IBR-2 pulsed reactor (Laboratory of neutron physics, Joint Institute for Nuclear Research, Dubna, Russia) to solve a whole array of problems, with an eye toward applying these in biophysics, structural biology, and biotechnology. This review presents and discusses the main findings of the studies of various biological systems obtained by using the setup small-angle scattering of neutrons YuMO. The possibilities of development of structural biology methods with the help of small-angle scattering, including protein crystallization, are shown.
The marvelous dna macromolecule: computer modeling of dna 3d structure and diversity of watson-crick duplex conformations
Authors: Poltev V. , Dominguez V. , Ruiz A. , Deriabina A. , Gonzalez E.
Published: April 2024

The work reviews the development of ideas about the 3D structure of DNA and the mechanisms of its formation, from the discovery of the Double Helix to the present day. It tracks the methods of modeling the 3D structure at different stages of the study of the main molecule of life. The discussion underscores a marvelous expedient in DNA molecular structure and its adaptability to important biological functions based on the results of calculations of the intra- and intermolecular interactions of macromolecule subunits. The work presents new data about substantial contribution of chemically monotonous and conformationally flexible sugarphosphate backbone to the formation of sequence-dependent 3D structure of DNA. The diversity of the conformational possibilities of DNA is visible both in the formation of duplexes (as well as triplexes and quadruplexes) with different geometric parameters for base pairs and in the formation of duplexes with Watson-Crick nucleoside pairs containing local conformations corresponding to different regions of the torsion angles of the sugar-phosphate backbone (different conformational classes). Based on our calculations, these classes can be divided into two groups. The first group includes local conformations in which the torsion angles are close to one of energy minima of its isolated elemental repeating fragment, and the second group consists of conformations with one or more of these angles deviating from that of the nearest energy minimum by more than 30°. The regularities of the formation of the local 3D structure of these two groups differ significantly.
Influence of neurotrophic factors on protein composition during somatic nerve injury and regeneration
Authors: Kuzmenko T. P , Parchaikina M. V , Revina E. S , Gladysheva M. Yu , Revin V. V
Published: April 2024

The quantity of neurotrophic factors and the protein composition of somatic nerve membranes in rats during injury and survival of nerves under the action of clobetasol have been explored. It has been shown that the drug administered intramuscularly produces more pronounced effect on the increase in the level of neurotrophic growth factors and structural proteins responsible for recovery processes than the drug released from hydrogel derived from microbial polysaccharides as well as stabilizes the content of the total protein fraction of damaged somatic nerves. Proteins of the injured neural conductor are less degraded during intramuscular injection of clobetasol probably because of better availability of the drug administered by injection than availability of the drug administered (slow drug release) from hydrogel composite. In addition, an increase in the amount of DNA and some protein fractions indicates that clobetasol is able to participate in an activation of genes associated with remyelination. We suppose that clobetasol can stimulate synthesis of neurotrophic growth factors, thereby triggering phosphatidylinositol-3-kinase and mitogen-activated protein kinase signaling pathways that regulate the processes of cytoskeletal reorganization and axonal growth, as well as enhance the rate of synthesis of structural and axonal proteins necessary to restore the functional activity of injured nerve conductors.
A shift of the prooxidant-antioxidant balance in the bodies of laboratory animals at five-fold increased deuterium content in drinking diet
Authors: Kozin S. V , Lyasota O. M , Kravtsov A. A , Chikhirzhina E. V , Ivlev V. A , Popov K. A , Dorohova A. A , Malyshko V. V , Moiseev A. V
Published: April 2024

This paper presents the results of the study of the effect of water with deuterium content of 750 ppm, used for simulation of the isotopic composition of water in ice caps at the poles of Mars, on oxidative processes in the liver tissue and blood of laboratory animals. It was found that prolonged consumption of deuterium-enriched water contributed to an increase in the deuterium content in blood plasma up to 487 ppm. As a result, increased antioxidant activity in the liver tissues and blood plasma was observed. In addition, the effect of a medium that contains 487 ppm of deuterium on the secondary structure of bovine serum albumin was also investigated in a model experiment. A decrease in intensity of circular dichroism and intrinsic tryptophan fluorescence spectra was found. This indicates that there are conformational changes in the structure of this protein at a time when the content of deuterium increases in the incubation medium. The results of our research point to the need to explore further the effect of drinking diet with the increased deuterium to (from 700 to 1000 ppm) on living systems, to explain the possibility for life on Mars.
Application of optical analysis methods for non-invasive monitoring of blood oxygen saturation level
Authors: Guzenko M. M , Mazing M. S , Zaitseva A. Yu
Published: April 2024

An intelligent optical system for medical express diagnostics has been developed and tested. A method for visualizing the oxygen status of biological tissues in the form of "digital images" describing the general functional state of the human body is demonstrated. It has been shown that the method of principal components and hierarchical clustering can be used in combination with optical methods for detecting hemoglobin forms in biological tissues to perform non-invasive monitoring and express diagnostics of the oxygen status of the human body. The results obtained show that it is possible to stratify the subjects into risk groups based on optical sensor readings. In comparison with pulse oximetry, the use of which is common for determining the oxygen saturation level of blood, the described method can be employed to estimate peripheral oxygen saturation, and thus thrombosis and ischemia of the extremities can be detected in time.
Prediction of metabolic activity of rowing athletes based on serum biochemical analysis
Authors: Pustovoyt V. I , Astrelina T. A , Balakin E. I , Kobzeva I. V , Suchkova Y. B , Khan A. V , Murtazin A. A , Maksjutov N. F , Brumberg V. A
Published: April 2024

Determination of the metabolic state is an important topic in sports medicine. Biochemical and hematological blood parameters reflect the predominance of anabolic or catabolic processes in metabolism, these parameters depend on intensity and duration of workouts. The aim of the present study was to determine whether metabolic processes are dominant. 21 male rowing athletes (age: 22.55 ± 3.68 years, height: 189.62 ± 6.34 cm, weight: 88.65 ± 8.55 kg) participated in the experiment. Monitoring of blood concentrations in samples collected from participating athletes and measuring workout intensity led to the use of a linear-discriminant function. With this technique, the eight main blood count parameters: creatinine (p < 0.001), uric acid (p < 0.001), urea (p < 0.001), testosterone (p < 0.001), ALP (p < 0.001), albumin (p < 0.05), total calcium (p < 0.05), and total protein (p < 0.05) for the prediction of the metabolic state have been determined. The reliability of test results using a linear-discriminant function for the prediction of the metabolic state in athletes was supported by a strong positive correlation (r = 0.88, p < 0.001) with the results of the neuroendocrine system activity assessments. The accuracy of the metabolic state prediction was 91.8%.
Glow discharge treatment of nitrocellulose membranes increases the immunoassay sensitivity
Authors: Petrova P. A , Zamalutdinova S. V , Vnukova A. A , Alekseeva D. A , Bagrov D. V
Published: April 2024

Plasma treatment can make the surfaces of the materials more hydrophilic and improve the surface and adsorption properties. Our research shows that the glow discharge treatment of nitrocellulose membranes improves the adsorption capacity for antibodies by a factor of 15-17 and increases the sensitivity of immunoassay (dot-blotting) performed on the membranes approximatively by an order of magnitude. This feature has been demonstrated for the interleukin-1 beta immunoassay with chemiluminescent detection. Upon glow discharge treatment, the nitrocellulose membranes did not change their structure or chemical composition as can be seen using scanning electron microscopy and IR spectroscopy, respectively. The obtained results can be used to optimize the existing laboratory procedures, especially dot-blotting.
Changes in the activity of micromycete endocellular oxidoreductases under the influence of low-frequency pulsed magnetic field and low-intensity laser radiation
Authors: Makarov I. O , Klyuev D. A , Smirnov V. F , Smirnova O. N , Anikina N. A , Dikareva N. V , Shishkin A. Yu
Published: April 2024

This study aims to investigate the effects of low-frequency pulsed magnetic field (1.5 Hz) and low-intensity laser radiation (0.3 and 0.7 W) on the activity of micromycete endocellular oxidoreductases that catalyze biodegradation of industrial materials such as Penicillium cyclopium, Aspergillus niger, and Alternaria alternata. The investigated physical factors had dose-dependent effects on the activity of fungal endocellular oxidoreductases (catalase and peroxidase): increases and decreases in the activities of enzymes have been observed. An increase in the activity of enzymes can contribute to the manifestation of the adaptive properties of fungi against the action of such physical factors as low-intensity laser radiation and magnetic field. A decrease in the activity of endocatalase and endoperoxidase under the influence of these factors may suppress the vital activity of microorganisms.
Mechanism of action of the low-frequency electromagnetic field on aqueous solutions of biopolymers
Authors: Tekutskaya E. E , Ilchenko G. P , Baryshev M. G
Published: April 2024

This paper presents the mechanism of signal transformation by which a signal from the magnetic component of the low-frequency electromagnetic field with extremely low energy is changed into chemical and biochemical signals which elicit a biological response in aqueous solutions of biopolymers based on nucleic acids and proteins. A theoretical model developed shows that the basis of oxidative DNA damage and conformational transitions of proteins is a universal mechanism associated with a change in the amount of the most long-lived form - hydrogen peroxide in a chemical oscillator of mutual transformations of reactive oxygen species under the influence of low-intensity electromagnetic field exposure. It has been experimentally established that the quantitative content of hydrogen peroxide in solutions of biopolymers resonantly depends on the frequency of applied field. Conformational changes in proteins are accompanied by an increase in the availability and activity of the nucleophilic centers that are potential targets for reactive oxygen species. Complete unfolding and denaturation of the amino acid chain of the protein under the influence of low-frequency electromagnetic field exposure do not occur. It has been shown that enhanced hydrogen peroxide formation at 3 Hz and 50 Hz leads to oxidative modification of nitrogenous bases in DNA.
Genetic determinants of flax genome integrity
Authors: Kanapin A. A , Samsonova A. A
Published: April 2024

Recent advances in high-throughput sequencing methods have enabled development of an innovative approach to evaluation of genome stability and integrity. The depth of the coverage signal at a particular location of the genome may indicate the loss of DNA integrity in the region. In this work, the previously developed metric of local genome integrity that estimates the uniformity of coverage signal is considered a quantitative trait and a search for genetic variants associated with the uniformity of coverage signal in flax genome is performed. In particular, quantitative trait locus (xQTL) analyses (i.e., x Quantitiave Trait Loci, where x is the designation of an arbitrary quantitative characteristic associated with a particular genome region; for example, the level of gene expression, the degree of ribosome coverage, etc.) have been applied to identify genomic regions that most likely contribute to loss of genome integrity and are, probably, involved in the maintenance of genome stability. The analysis carried out using information on whole-genome sequence assembly of 100 flax samples enabled identification of genes potentially implicated in genome integrity maintenance in flax and, possibly, in plants in general and also revealed novel processes associated with the maintenance of genome integrity.
Oxidative homeostasis in germinating pea seeds (isum sativum) depending on ultrasonic exposure duration
Authors: Tarasov S. S , Krutova E. K
Published: April 2024

The effects of ultrasonic exposure durations (5, 10 and 20 min) with intensity of 25 kW/m2 and the frequency of 26.1 kHz on the extent of lipid peroxidation, oxidative modification of proteins, the activity of cysteine proteinases, and gene expression in germinating pea seeds were studied. It has been shown that the intensity in the area that had seeds planted (just over the central ultrasound generator) was rather uniformly distributed, but at the same time gave rise to diffuse reflection. A range of tendencies in changes of the indicators under study were seen after ultrasound exposure. The level of malonic dialdehyde increased with increasing duration of ultrasound exposure. This study revealed the increased amount of oxidized proteins in germinating pea seeds after a 10 min-exposure to ultrasound, and a decrease in the level of oxidative modification of proteins present in seeds subjected to ultrasound for a period of 20 min. The activity of cysteine proteinases was higher in pea seeds after a 5-min exposure to ultrasound, but the amount of mRNA transcripts increased in all experimental samples.
Nanotechnologies for drug therapy of malignant tumors
Authors: Korman D. B , Ostrovskaya L. A , Bluhterova N. V , Rikova V. A , Fomina M. M
Published: April 2024

The review brings together experimental data from studies aimed to uncover the opportunities for application of nanotechnology in drug therapy of malignant tumors.
Structure of an ice-binding protein from myoxocephalus octodecemspinosus determined by molecular dynamics and based on circular dichroism spectra
Authors: Oleinik G. A , Zhdanova P. , Koval V. V , Chernonosov A. A , Baranova S. V
Published: April 2024

One of the survival strategies evolved by the organisms living in cold ecosystems is production of ice-binding proteins. An important feature of these proteins is to bind to the surface of ice, keep the ice from growing and prevent cells from damage and death. To understand the mechanism underlying interaction between icebinding proteins and ice, it is necessary to know the structure of these extraordinary proteins. This study contributes towards information on the structural and dynamic mechanisms of ice-binding proteins that ensure the adaptation of organisms to extreme conditions. Research on the mechanisms by which ice-binding proteins develop adaptation to cold opens up great opportunities in solving a wide range of interesting problems in medicine, such as the development of effective cryoprotectants for cells and organs, as well as in the food industry, such as long-term food storage without losing nutritional quality at the consumer level.
Free radicals and signal transduction in cells
Authors: Martinovich G. G , Martinovich I. V , Voinarouski V. V , Grigorieva D. V , Gorudko I. V , Panasenko O. M
Published: April 2024

This review provides an overview of molecular mechanisms of intracellular signal transduction involving free radicals. The structure and functions of enzymes that can form superoxide anion-radical and hydrogen peroxide are considered in detail. The mechanisms of regulation of cell properties with the participation of specialized redox chains formed by a group of proteins interacting through electron transport processes are discussed. Genetically mediated mechanisms of regulation of redox cell homeostasis are analyzed. Particular attention is paid to the issue concerning quantitative characterization of the network of interactions of oxidizing and reducing agents, which determines the species and individual characteristics of redox homeostasis and the stress response of cells.
Haloperidol, a sigma-1 receptor antagonist, inhibits Ca2+ responses in rat peritoneal macrophages
Authors: Milenina L. S , Krutetskaya Z. I , Antonov V. G , Krutetskaya N. I
Published: April 2024

Sigma-1 receptors are ubiquitous multifunctional ligand-operated molecular chaperones in the endoplasmic reticulum membrane and have a unique history, structure, and pharmacological profile. Sigma-1 receptors modulate a wide range of cellular processes in health and disease and Ca2+ signaling processes. Using the Ca2+ sensitive fluorescent ratiometric dye Fura-2AM, it has been shown that neuroleptic (haloperidol, an antagonist of sigma-1 receptors) significantly suppresses Ca2+ mobilization from intracellular Ca2+ stores and subsequent store-dependent Ca2+ entry, induced by thapsigargin and cyclopiazonic acid, as inhibitors of endoplasmic reticulum Ca2+-ATPases, and also by glutoxim and molixan, disulfide-containing immunomodulatory drugs, in rat peritoneal macrophages. Findings of the study revealed that sigma-1 receptors are involved in the complex signaling cascade triggered by glutoxim or molixan that leads to the increase in the intracellular Ca2+ concentration in macrophages and participate in regulation of store-dependent Ca2+ entry in macrophages.