bluuebunny/crossref_metadata_2025 huggingface dataset:
Model of Fractal Organization of Chromatin in Two-Dimensional Space
Authors: Grigor'ev S. V , Shnyrkov O. D , Pshenichnyy K. A , Pustovoyt P. M , Yashina E. G
Published: April 2024

Chromatin, consisting of a meter-long DNA strand and associated proteins, is packed into the nucleus of a biological cell tightly but without entanglement. There is a hypothesis, confirmed by experiments involving the chromatin conformation capture technology [1], that curves densely filling the space (Peano or Hilbert curves) provide a good theoretical model to describe the chromatin packing into the nucleus. However, small-angle neutron scattering (SANS) experiments show a bifractal organization of chromatin in the interphase nucleus, thus demonstrating the presence of a logarithmic fractal on larger scales and a volume fractal on smaller scales [2]. In this paper, numerical Fourier analysis in the two-dimensional space is applied to simulate neutron scattering, and a model of a unified bifractal object is presented. It is shown that, in numerical radiation scattering experiments in the two-dimensional space, the mass and logarithmic fractals are significantly different from space-filling curves and from nonfractal objects. For instance, for a logarithmic fractal with a Hausdorff dimension of 2, scattering intensity decreases with increasing Fourier coordinate q by the power law q–2. For curves filling the two-dimensional space, the intensity decreases by the power law q–3, just as for nonfractal objects with sharp boundary in the plane. Thus, first, it is demonstrated that the model of space-filling curves is inadequate to describe the chromatin packing into the nucleus of a biological cell; second, a model of a unified bifractal object is proposed that combines logarithmic and mass fractals on different scales; and, third, a model of chromatin packing is proposed that can describe the data of both small-angle neutron scattering experiments and experiments involving chromatin conformation capture technology.
Current Spreading in Thin Foils or Flat Current Sheets
Authors: Garanin S. F , Kravets E. M
Published: April 2024

To consider the evolution of current distribution in inhomogeneous thin conductive layers or foils, we apply an integrodifferential equation, which reduces the three-dimensional problem for the magnetic field to a two-dimensional problem, and, for the current distribution across the width of inhomogeneous conductive sheets or foils, this equation reduces the two-dimensional problem for the magnetic field to a one-dimensional problem. For homogeneous conductive layers with constant conductivity, the spatial scale of current distribution, initially concentrated in a limited area, increases proportionally to time at a rate of u = c2/4πσΔ, where σ is the conductivity of the layer material and Δ is its thickness. As an application to the problems of current transfer through electroexplosive opening switches, a current distribution across the width of a foil is considered for a periodic serpentine-type system of flat foils. It is shown that initially a current distribution corresponding to the perfect conductivity of foils is established in this system. Then, in a time on the order of s/u (2s is the width of a foil), the current distribution in the foil relaxes to a uniform distribution. Estimates show that if the foils are used as opening switches, then currents through the foils during the current transfer to the load are expected to have time to get uniformly distributed across their width; therefore, corrections for the nonuniformity of the current distribution in the switches should be small.
Studying the Influence of T2O Substitution for H2O on the Dynamic Properties, Density Maximum, and Melting Point of Ice in Terms of the Lattice Dynamics Method
Authors: Belosludov V. R , Gets K. V , Zhdanov R. K , Bozhko Yu. Yu , Kavazoe E.
Published: April 2024

An isotopic effect arising from the substitution of superheavy water molecules for normal water molecules in ice (Ih) has been studied by the lattice dynamics method in a quasi-harmonic approximation using a rigid three-point potential modified to reproduce the superheavy water properties. It has been shown that the considerable variation of the vibrational state density upon substituting 12.5, 50, and 100% of water molecules takes place only in the range of libration. The temperature dependence of the superheavy ice density has been calculated, and the density maximum for this ice near 60 K has been predicted. A relationship between the melting point of (T2O + H2O)-ice Ih and the T2O molecule concentration in its structure has been constructed, and this relationship has been found to be linear.
Electric Polarization in the BiMn7O12 Quadruple Manganite: A 57Fe Probe Mössbauer Investigation
Authors: Nitsenko V. I , Sobolev A. V , Belik A. A , Glazkova Ya. S , Presnyakov I. A
Published: April 2024

The electrical hyperfine interactions of the probe 57Fe nuclides localized in the structure of the quadruple manganite BiMn7O12 are studied by Mössbauer spectroscopy. The measurements are carried out in the temperature range 101 K T 447 K, where this manganite has a nonzero spontaneous electric polarization (Ps); moreover, this range includes the temperature (T* ≈ 240 K) of the P1 ↔ Im structural phase transition. The parameters of the hyperfine interactions of the partial spectra of the 57Fe nuclei are comprehensively analyzed, and their crystal-chemical correspondence to certain positions of Jahn–Teller Mn3+ ions in the structure of manganite is performed. The “dynamic” Born charge model is used to develop an algo rithm to construct the temperature dependence of the polarization of the crystal Ps(T) using structural data of the compound and the experimental values of the quadrupole splittings Δ(T) of the Mössbauer spectra of the 57Fe probe atoms. The Ps(T) dependences obtained on both sides of point T* are analyzed in terms of the mean-field model.
Analysis of the Effect of the Incoming Flow Velocity on the Flow Induced by a Dielectric Barrier Discharge
Authors: Polivanov P. A , Vishnyakov O. I , Kislovskiy V. A , Sidorenko A. A
Published: April 2024

Plasma actuators based on a dielectric barrier discharge (DBD) are considered as a promising method оf flow control. Their main advantage is the possibility of flow acceleration by the ion wind without using movable elements. The generation of the ion wind by DBD in a settling gas has been studied quite comprehensively. At the same time, almost all aerodynamic applications of this method of flow control presume the presence of an external flow. However, the emergence of a bulk force in DBD in such conditions has not been investigated in detail. This study is devoted to detailed analysis of this effect. We have investigated the influence of DBD on the velocity distribution near electrodes using the PIV method and have calculated the bulk force generated by the ion wind. The results of this study demonstrate a substantial effect of the incoming flow velocity on the ion wind generation.
Statistics of a Passive Scalar in a 2D Shear Flow with Fluctuations
Authors: Ivchenko N. A , Vergeles S. S
Published: April 2024

We study statistical properties of the passive scalar advection in a 2D flow that consist of a steady-state shear flow and a relatively weak smooth random component taking into account the effects of finite weak diffusion. The model is closely related to the dynamics of passive scalar transfer inside coherent vortices emerging as a result of an inverse cascade in 2D turbulence. We analyze both the decay of the passive scalar and the problem with continuous supply of the scalar to the system. In both cases, the passive scalar distribution exhibits strong intermittence, which can be indicated with single-point moments calculated in this study.
Compact Generator of an Optical Frequency Comb Based on Distributed-Feedback Laser Diode and High-Q Optical Microcavity
Authors: Ruzhitskaya D. D , Vorob'ev K. A , Bulygin F. V , Kuzin A. Yu , Min'kov K. N
Published: April 2024

Optical frequency combs are a unique tool for fundamental metrology and spectroscopy; they are also used in various applications. High-Q microcavities are promising for generating coherent frequency combs. An approach based on the pulling effect, which is well-known in radiophysics, is proposed. The use of this effect makes it possible to develop a compact, commercially available source of an optical comb and microwave radiation based on a compact distributed-feedback laser diode with a low output power of 6 mW and a microcavity based on magnesium fluoride with a Q factor of 109. Different generation modes of optical frequency combs, corresponding to different numbers of generated solitons at a pump power of 6 mW and a wavelength of 1550 nm, as well as spectrally pure microwave radiation at a frequency of 12.94 GHz, are demonstrated.
Chiral Symmetry Breaking and Inhomogeneous States in Deformed Ferromagnets
Authors: Fraerman A. A
Published: April 2024

The general form of chiral terms associated with deformation of a ferromagnet is determined. The possibility of a transition from the helical state to the vortex state is demonstrated for a ferromagnetic rod subjected to elastic torsional strain. In the case of a single screw dislocation, the formation of the skyrmion state due to elastic strains and the helical distribution of magnetization induced by strains in the dislocation core is indicated. The conditions in which a transition from one chiral magnetization distribution to another distribution in an ensemble of identical dislocations are determined.
Induced Charge Generated by Potential Well in Transition Metal Dichalcogenides
Authors: Terekhov I. S
Published: April 2024

We investigate the asymptotic behavior of the charge density ρind(r) induced by an azimuthally symmetric potential well of finite radius R. The analytic expression for ρind(r) at the distances r ≫≫ R is obtained. It is shown that, for a wide range of potential parameters, the induced charge density can be represented as ρind(r) = F(r)LV, where F(r) depends only on distance and LV depends on the parameters of the potential. We also investigate the behavior of the induced charge density when the potential well depth close to the critical value.
Influence of the Encapsulating Layer Thickness on the Quality of MoSe2-Based Heterostructures
Authors: Brichkin A. S , Golyshkov G. M , Chernenko A. V
Published: April 2024

The dependence of the width of exciton and trion photoluminescence lines in MoSe2 monolayers on the thickness of hexagonal boron nitride encapsulating layers has been investigated. The possibility of variation of the exciton photoluminescence linewidth due to the interaction of excitons with the modes of resonator cavities made up of a silicon substrate and a boron nitride top layer has been checked. This interaction may significantly change the photoluminescence linewidth owing to the Parcell effect. Measurements taken of samples with different thicknesses of the bottom and top boron nitride layers have not revealed any influence of the Parcell effect on the linewidth. It has turned out however that the linewidth narrows by several times with increasing boron nitride bottom layer thickness from 10 to 100 nm and reaches 2 meV at a thickness of 100 nm. Supposedly, such narrowing of the photoluminescence line is associated with a decrease in the density of submicron bubbles, which takes place at longitudinal stress relaxation in the thicker layer of boron nitride.
Dipole Plasmon Mode in Nanosize Semiconductor Core–Shell Quantum Dots with a Type II Heterojunction
Authors: Ipatov A. N
Published: April 2024

Excited states of nanosize two-component semiconductor core–shell crystals with a type II heterojunction are analyzed. It is demonstrated that the dipole plasmon resonance dominates in their photoabsorption spectra. It is found that the variation of the potential barrier height between the core and the shell in a comparatively narrow range leads to a fundamental change in the form of the collective mode from the surface plasmon resonance typical of the photoabsorption spectra of conducting nanosize particles to the rotational plasmon mode, for which only angular degrees of freedom are excited.
High Harmonic Generation with Many-Particle Coulomb Interaction in Graphene Quantum Dot
Authors: Sedrakyan Kh. V. , Kazaryan A. G. , Avchyan B. R. , Musaelyan G. A. , Markosyan T. M.
Published: April 2024

The multiphoton excitation and high harmonic generation (HHG) processes are considered using the microscopic quantum theory of nonlinear interaction of strong coherent electromagnetic (EM) radiation with rectangular graphene quantum dot (GQD) with zigzag edges and more than 80 atoms. The dynamic Hartree–Fock approximation has been used to consider the quantum dot-laser field nonlinear interaction at the nonadiabatic multiphoton excitation regime. The many-body Coulomb interaction is described in the extended Hubbard approximation. By numerical results, we show the significance of the rectangular GQD lateral size, shape, and EM wavefield orientation in rectangular GQD of the zigzag edge in the HHG process allowing for increasing the cutoff photon energy and the quantum yield of higher harmonics.
Analysis of the process e+e- → h0a0 in ihdm in the presence of a linearly polarized laser field
Authors: Ouhammou M. , Ouali M. , Taj S. , Benbrik R. , Manaut B.
Published: April 2024

We consider the process of neutral Higgs production from e+e- annihilation in Inert Higgs Doublet Model (IHDM) in the absence and presence of an external eld. The latter is assumed to be a plane and monochro-matic wave with linear polarization. In the theoretical framework, we present the analytic calculation of the lowest order di erential cross section by using the scattering matrix approach and Dirac-Volkov formalism for charged incident particles. The total cross section is computed by performing a numerical integration of the di erential cross section over the solid angle. The results obtained are analyzed and discussed for di erent centre of mass energies and laser parameters. We found that inserting a laser wave with linear polarization is a suitable mechanism to enhance the total cross-section of the process. Indeed, the probability of the process to occur increases with the presence of a linearly polarized laser eld, especially with low frequency and high strength.
Easy-Plane Antiferromagnet in Tilted Field: Gap in Magnon Spectrum and Susceptibility
Authors: Shcherbakov A. S. , Utesov O. I.
Published: April 2024

Motivated by recent experimental data on dichloro-tetrakis thiourea-nickel (DTN) [Soldatov etal., Phys. Rev. B101, 104410 (2020)], a model of antiferromagnet on a tetragonal lattice with single-ion easy-plane anisotropy in the tilted external magnetic field is considered. Using the smallness of the in-plane field component, we analytically address field dependence of the energy gap in “acoustic” magnon mode and transverse uniform magnetic susceptibility in the ordered phase. It is shown that the former is non-monotonic due to quantum fluctuations, which was indeed observed experimentally. The latter is essentially dependent on the “optical” magnon rate of decay on two magnons. At magnetic fields close to the one which corresponds to the center of the ordered phase, it leads to experimentally observed dynamical diamagnetism phenomenon.
Observation of Kapitza–Dirac Diffraction in Atomic Lithium Gas Using Bragg’s Scattering
Authors: Baturo V. V. , Vinogradov V. A. , Platonova M. V. , Yukhnovets I. V. , Turlapov A. V.
Published: April 2024

A short-lived density grating is produced in a gas of lithium atoms. The gas is preliminarily cooled in a magnetooptical trap. The grating is formed due to diffraction of atoms on a standing light wave. The grating is observed from Bragg’s scattering of light from it. This method of formation and observation over the grating can be used in a lithium-based atomic interferometer.
Laser Cooling of Lithium-6 Atoms in a Bichromatic Light Field
Authors: Il'enkov R. Ya. , Prudnikov O. N. , Kirpichnikova A. A. , Taychenachev A. V. , Yudin V. I.
Published: April 2024

The kinetics of6Li atoms in a bichromatic laser field exciting transitions on D2 and D1 lines is investigated. The model takes into account the complex real structure of energy levels of6Li (including the Zeeman degeneracy) as well as the nonuniform spatial polarization of the laser field. It is found that detuning and the polarization configuration of the light field component of the resonant D2 line of the6Li atom are of fundamental importance for laser cooling. The possibility of cooling of atoms below the Doppler limit is demonstrated.
Three-Photon Laser Excitation of Single Rydberg Rubidium Atoms in an Optical Dipole Trap
Authors: Beterov I. I. , Yakshina E. A. , Tret'yakov D. B. , Al'yanova N. V. , Skvortsova D. A. , Suliman G. , Zagirov T. R. , Entin V. M. , Ryabtsev I. I.
Published: April 2024

Three-photon laser excitation of single rubidium atoms in an optical dipole trap (ODT) into the37P Rydberg state by laser radiation with wavelengths of 780, 1367, and 743 nm has been experimentally demonstrated. The excitation to Rydberg states is detected by an optical method using the losses of atoms in the ODT. The laser excitation spectra of single Rydberg atoms in the ODT are recorded, and the dependence of the excitation probability on the laser pulse duration is measured. The measured spectrum width was 2MHz. Experiments on fluorescence quenching spectroscopy of a cloud of cold atoms in a magneto-optical trap during the three-photon laser excitation of atoms to Rydberg states are also carried out. The experimental results are compared with a numerical calculation. Methods for increasing the accuracy of the coherent three-photon laser excitation of Rydberg atoms in the ODT are considered.
Pinning of a Magnetic Flux in Polycrystalline YBa2Cu3O6.92 HTSC during Cooling in a Weak Magnetic Field
Authors: Trusevich N. G. , Gavrilkin S. Yu. , Trakhtenberg L. I.
Published: April 2024

The behavior of fine-grained YBa2Cu3O6.92HTSCs during cooling in a weak magnetic field is investigated. The magnetization of samples, the crystallite sizes is which are comparable with the magnetic field penetration depth, is comprehensively analyzed in the range below the superconducting transition temperature. When the crystallite size is smaller than 0.5 μm, vortices are shown not to be fixed to pinning centers, and the temperature dependence of magnetization is completely determined by the screening of crystallites and the temperature of appearance of intercrystallite superconducting currents.
Influence of Impurities on Adhesion at the TiAl/Al2O3 Interface
Authors: Bakulin A. V. , Kul'kov A. S. , Kul'kova S. E.
Published: April 2024

The influence of substitutional impurities on adhesion at the TiAl/Al2O3interface with an oxygen termination has been studied by the projector augmented-wave method within the density functional theory. It has been shown that transition metals and a number ofs,p-elements substituting for the interfacial titanium atom reduce adhesion, whereas Group VB and VIB elements enhance chemical bonding at the interface. The local densities of states, charge density distribution, overlap populations for interfacial atom bonding, and other electronic characteristics have been calculated that make it possible to reveal key factors influencing adhesion at the alloy–oxide interface. A correlation has been found between the influence of impurities on bonding energy at the inner and outer interfaces. A comparison of obtained data with those for the interface with Ti-enriched Ti3Al alloy shows that the interface loses strength with decreasing Ti content in the alloy.
Bragg Resonances in a Multiferroic Double-Nonlinearity Crystal
Authors: Morozova M. A , Matveev O. V , Romanenko D. V , Nikitov S. A
Published: April 2024

The influence of double (electrical and magnetic) nonlinearity on the Bragg resonances of the hybrid electromagnetic-spin waves in a multiferroic crystal has been theoretically and experimentally revealed. The multiferroic crystal consists of an yttrium iron garnet layer with a periodic system of grooves on the surface and a ferroelectric strontium–barium titanate layer. A dispersion relation for the hybrid waves is obtained, and the mechanism of formation of main and hybrid band gaps, namely, suppression bands, is revealed. It is shown that taking into account the magnetic nonlinearity leads to frequency rearrangement of both band gaps and taking into account the electrical nonlinearity leads to frequency rearrangement of only the hybrid band gap. In the general case, the effects of the electrical and magnetic nonlinearities on the hybrid band gap can be compensated.
Influence of the Effects of Competition of Various Types of Anisotropy on the Critical Behavior of Magnetic Multilayer Structures
Authors: Min'kova A. V. , Prudnikov V. V. , Prudnikov P. V.
Published: April 2024

The influence of the competition of single-ion anisotropy and easy-plane anisotropy on the magnetic properties of the multilayer structure Co/Cu/Co is investigated. The peculiarities of the influence of anisotropy effects are revealed both in the vicinity of critical temperature Tc and in the low-temperature range T Tc. The magnetic properties of the multilayer structure are numerically simulated using the anisotropic Heisenberg model. In the vicinity of Tc, easy-plane anisotropy is shown to exert a predominant influence on the magnetic properties of the structure as compared to the influence of single-ion anisotropy. In the low-temperature range, the switching of the magnetic state of the ferromagnetic film in an external field leads to the appearance of specific features in hysteresis effects due to the competition of two types of magnetic anisotropy. The magnetic structure exhibits a size-induced transition from the behavior caused by easy-plane anisotropy to the behavior caused by single-ion anisotropy. The revealed size-induced transition is accompanied by a spin-flop effect.
Effect of Noise on Resistive Switching of an Yttria Stabilized Zirconia Based Memristor
Authors: Gorshkov O. N. , Filatov D. O. , Koryazhkina M. N. , Lobanova V. A. , Ryabova M. A.
Published: April 2024

The effect of Gaussian noise on the switching of a ZrO2(Y) based memristor from the low resistance state (LRS) into the high resistance state (HRS) including transitions from the LRS into intermediate metastable states has been studied. The series of positive (with addition of the noise signal or without the one) and negative rectangular voltage pulses were used as the switching signals. The adding of noise to the switching signal initiated the switching of the memristor from the LRS into the HRS at smaller pulse magnitudes than in the case of switching by the rectangular pulses without adding the noise. A necessary (preset) HRS can be achieved passing the intermediate states by adding the noise with certain parameters to the rectangular switching pulses. The resistive switching is performed without application of adaptive switching protocols. The results of the present study can be applied in the development of innovative memristor switching protocols.
Hydraulic Jump for Planar and Axisymmetric Flow of a Fluid Layer
Authors: Sukhov A. D. , Petrov A. G.
Published: April 2024

We consider fluid flow with a free boundary, which is defined as a function of height from coordinate x with two asymptotes at positive and negative infinities (hydraulic jump). The Boussinesq approximation is used to describe the phenomenon, and an additional force is introduced. The force is chosen to depend only on the height of the surface. The problem is solved analytically without using numerical schemes. This technique is used to determine the jump surface and the acting force depending on the wave propagation coordinate.
Comment to the Article “On the Time Integral of Electromagnetic Field” by R.M. Feshchenko (J. Exp. Theor. Phys. 136, 406 (2023))
Authors: Arkhipov M. V. , Arkhipov R. M. , Rozanov N. N.
Published: April 2024

The article by R. M. Feshchenko (J. Exp. Theor. Phys. 136, 406 (2023)) is devoted to an important issue concerning general properties of electromagnetic field pulses and contains, in particular, critical remarks on our publications (R. M. Arkhipov et al. Quant. Electronics 50, 801 (2020); R. Arkhipov et al., Laser Field Lett. 19, 043001 (2022), and M. V. Arkhipov et al., JETP Lett. 115, 1 (2022)). We reply to these critical remarks and indicate a number of inaccuracies in the aforementioned article.
Interatomic Interaction at the Al–TiC Interface
Authors: Reshetnyak V. V. , Aborkin A. V. , Filippov A. V.
Published: April 2024

The interaction of a titanium carbide nanoparticle with aluminum (100), (110), and (111) substrates is investigated within the density functional theory. The nanoparticle–substrate interaction energies are determined; the electron density distribution and the electron localization function between aluminum, titanium, and carbon atoms are analyzed. It has been established that the atoms in the upper layers of the aluminum (100) and (110) substrates are significantly displaced relative to their initial positions as a result of the interaction with the nanoparticle, whereas a minor displacement of atoms is typical for the (111) substrate. The interaction between aluminum and carbon atoms at the Al–TiC interface is due to the formation of covalent Al–C chemical bonds. The aluminum atoms forming carbide bonds do not form chemical bonds with titanium atoms. The aluminum atoms that are adjacent to the titanium atoms and are not involved in the formation of carbide bonds form metallic Al–Ti bonds.
On the Heat Capacity of Quantum Hard Sphere Fluid
Authors: Stishov S. M.
Published: April 2024

The thermodynamic properties of the Boltzmann hard sphere system is discussed. It was found that zero point energy decreases with temperature so slowly that it turned out to be an almost a constant addition to the classical value. In result the heat capacity of the system differs little from the classical value of 3/2 k everywhere except for the narrow region of low temperatures, where heat capacity drops to zero. The predicted linear temperature contribution to the heat capacity like in ideal Fermi gas was clearly detected in the quantum hard sphere system at the lowest temperatures.
Dynamics, Symmetry, and Shock-Induced Dusting at Quasi-Isentropic and Isentropic Acceleration of Cylindrical Liners
Authors: Erunov S. V. , Ogorodnikov V. A. , Blikov A. O. , Knyazev V. N. , Kulakov E. V. , Georgievskaya A. B. , Davydov N. B. , Sokolova A. S. , Chudakov E. A.
Published: April 2024

Two devices intended for copper cylindrical liner gasdynamic acceleration to velocities of 5–7 km/s using the chemicals explosion energy have been investigated. It has been demonstrated that the acceleration of quasi-isentropically and isentropically loaded liners under the conditions of high-level dynamics, symmetry of deposition, and suppression of shock-induced dusting is feasible.
HIPPOCAMPAL VOLUME AND THE SPECTRUM OF METABOLITES IN ADULT GRAY RATS (RATTUS NORVEGICUS) SELECTED FOR DIFFERENT ATTITUDES TO HUMANS AND EXPOSED TO SOCIAL DISTURBANCE IN EARLY LIFE
Authors: Shikhevich S. G. , Akulov A. E. , Kozhemyakina R. V. , Moshkin M. P. , Herbeck Y. E. , Gulevich R. G.
Published: April 2024

Previous magnetic resonance studies of the dorsal hippocampus of male rats selected for aggressive attitude to humans revealed lower contents of γ-aminobutyric acid (GABA), N-acetylaspartate, and creatine+phosphocreatine and an elevated content of phosphorylethanolamine as compared to males selected for tame behavior. We investigated the influence of early social instability environment on the hippocampal volumes and spectrum neurometabolites in the dorsal hippocampi of adult tame, aggressive, and unselected rats. The experimental social instability included early weaning, subsequent housing in twos till the age of 3 months, a daily replacement of cagemates from days 19 to 25. Animals of the control groups were weaned at the age of 30 days and kept in fours or fives until the age of 3 months. Control aggressive males were inferior to tame in hippocampal volumes, absolute and normalized to individual brain volumes. The early social instability showed no effect on these indices. In the experimental groups, lower content of phosphorylethanolamine and higher content of alanine in the dorsal hippocampus as compared to control animals were recorded only in aggressive rats. This fact may be related to the formerly observed lower level of stress response in these animals. It follows from the results that aggressive rats are more sensitive to social instability conditions. Also, the early instability conditions and selection for aggressive behavior oppositely affect phosphorylethanolamine metabolism and the integral parameters of the metabolic profile in the dorsal hippocampus.
MORPHOLOGICAL ASYMMETRY OF ANTENNAE AND BEHAVIORAL ASYMMETRIES DURING GROOMING IN THE COCKROACH PERIPLANETA AMERICANA L.
Authors: Zhukovskaya M. I. , Novikova E. S.
Published: April 2024

Animal behaviors are often characterized by behavioral asymmetry, or lateralization, which is caused in part by the morphological asymmetry of the body and/or brain. To test the hypothesis that functional asymmetry of grooming is connected with morphological asymmetry of the antennae in American cockroach Periplaneta americana, we measured the length of the antennae, scapus diameter, pedicel diameter and length, and segment’s diameter and length. The data obtained indicate statistically significant differences: segment length is greater on the left antennae, and segment width is greater on the right antennae, except for a short region near the base. Correlation analysis revealed the following relationships: longer right antenna corresponds to more time spent cleaning it; scapus diameter larger on the right antenna correlates with antenna cleaning frequency; asymmetry of flagellum segments has no effect on cleaning asymmetry. Presenting sex pheromone at a suprathreshold dose increased asymmetry of antennal grooming, while asymmetry for leg grooming was generally unchanged. Thus, the asymmetry of antennal grooming, resulting at least in part from morphological asymmetry, significantly changes in the presence of a biologically important olfactory stimulus, the sex pheromone.
EFFECTS OF NEONATAL HYPOXIA AND ANTIDEPRESSANT FLUOXETINE ON COGNITIVE AND STRESS-HORMONAL FUNCTIONS IN ADULT RATS
Authors: Mikhailenko V. A. , Butkevich I. P. , Vershinina E. A.
Published: April 2024

The ability to spatial learning and the functionality of the spatial memory, and also the stressful reactivity of the hypothalamus-pituitary-adrenocortical axis (the HPA axis) were investigated in adult male and female rats, subjected to moderate acute hypoxia on the 2nd day of life, and then to chronic administration of the serotonin reuptake inhibitor fluoxetine. When testing the ability to spatial training in adult rats subjected to neonatal hypoxia, an increase in the latent period of reaching the platform in the Morris water maze in the first try in the first of five days of training was found. The results of memory analysis in the novel object recognition test and in the Morris water maze testify that hypoxia did not cause memory deficiency in adult animals. Moreover, hypoxia improved the memory indices on the first day in males and on the fourth day in females after removing the platform from the pool compared to the corresponding control values. The content of corticosterone in blood plasma of males in response to memory testing did not differ between control and experimental groups and was characterized by higher rates than in females of corresponding groups. Hypoxia increased the HPA axis reactivity in females, which was combined with a longer memory storage. Fluoxetine normalized the indicator of spatial learning, did not cause changes in control animals and did not change the identified improvement of memory in hypoxic rats without administration of this drug. The new data obtained expand the idea of the long-term effect of neonatal normobaric moderate hypoxia on the spatial memory and the HPA axis reactivity depending on sex and emphasize the absence of the harmful effect of fluoxetine on spatial memory in both control rats and in rats with the effects of hypoxia.
INFLUENCE OF ATRIAL ELECTRICAL STIMULATION ON THE TRANSMURAL SEQUENCE OF DEPOLARIZATION OF VENTRICULAR WALLS IN RAT HEART UNDER ZOLETHYL-XYLAZINE ANESTHESIA
Authors: Nuzhny V. P. , Kibler N. A. , Tsvetkova A. S. , Kharin S. N. , Barkhaev A. B. , Shmakov D. N.
Published: April 2024

The transmural sequence of depolarization of the free walls of the ventricles of the heart of Wistar rats was studied with an increase in the heart rate under zoletyl- xylazine anesthesia. The increase in heart rate was caused by atrial electrical stimulation. Zoletyl-xylazine anesthesia with intramuscular injection at a dose of 0.15 mg/kg of zoletil and 3 mg/kg of xylazine caused a significant negative chronotropic effect with pronounced bradycardia, characterized by a decrease in heart rate from the initial two times. With a reduced sinoatrial rhythm with a frequency of 237 ± 34 beats/min, the subendocardial layers were initially depolarized, then the intramural and further subepicardial layers of the left and right free walls of the ventricles of the heart. The areas of the bases of the free walls of the ventricles depolarized later than the apical areas by approximately 2–4 ms, also by the movement of the activation wave from the endocardium to the epicardium. With an increase in heart rate, the sequence and transmural depolarization gradient did not change. At the same time, an increase in the stimulation frequency from 300 to 500 beats/min led to a decrease in the time of arrival of the depolarization wave to the subendocardial, intramural, and subepicardial layers of the walls of the left and right ventricles. Despite the depressive effect of zoletyl-xylazine anesthesia on the heart and its chronotropic function, at a high frequency of atrial electrical stimulation, the depolarization gradient from the endocardium to the epicardium and from the apex to the base of the ventricles was preserved, there were only minor changes in the duration of the process of transmural depolarization of the walls of the ventricles of the heart. This indicates the resistance of activation of the ventricles of the heart of Wistar rats to the toxic effect of zoletyl-xylazine anesthesia.
EFFECTS OF COLD SHOCK ON THE SIZE AND ACTIVITY OF SCORPAENA PORCUS (LINNAEUS, 1758) NUCLEAR ERYTHROCYTES (IN VITRO EXPERIMENTS)
Authors: Shalagina N. E. , Soldatov A. A. , Bogdanovich Yu. V.
Published: April 2024

The in vitro effect of cold shock on erythrocytes of the benthic scorpionfish Scorpaena porcus L. was studied. The blood samples were exposed to 22°С (control group) and 4°С (experimental group) for 3 hours. Cold shock had no significant impact on erythrocyte scorpionfish vital function. The cells maintained the integrity of cytoplasmic membranes, mitochondrial potential and the level of oxidative processes, that the constant values of Propidium Iodide (PI), Rhodamine 123 (R123) and 2',7'-Dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence levels demonstrated. Main changes referred to erythrocyte shape and nucleus functional activity. Cells gained more roundish shape, nucleus size increased with the growth of the nuclear-cytoplasmic ratio (NCR) and the decrease of fluorescence intensity of the cells labeled with SYBR Green I. It appears to be related to the activation of transcriptomic processes.
ADAPTIVE MODIFICATION OF AMINO ACID POOLS IN THE MYOCARDIUM OF THE LONG-TAILED GROUND SQUIRREL UROCITELLUS UNDULATUS AT DIFFERENT STAGES OF HIBERNATION
Authors: Karanova M. V. , Zakharova N. M.
Published: April 2024

The state of hibernation is characterized by increased resistance to the effects of prolonged deep hypothermia, hypoxia, lack of food and water. At the same time, the restructuring of the adaptive mechanisms of animals at low temperatures, even for a short time, causes significant changes in metabolism, reflected in the pattern of amino acids. The change in the metabolism of free myocardial amino acids during hibernation has not yet been studied by anyone, but the idea of it is necessary to understand the mechanisms of the hibernation state, which is relevant for clinical medicine. In this regard, the task of this work was to study the changes in the composition of free amino acids of the myocardium of the ground squirrel U. undulatus at different stages of hibernation. A negative interdependence of glutamic acid and alanine pools at different stages of torpor was revealed. The decrease in the level of glutamic acid compared to the summer control (5.08 ± 0.44 μmolе/g wet weight) began in the first, December bout, continued with prolonged torpor (up to 1.57 ± 0.14 μmolе/g) and was accompanied by a corresponding increase in the alanine pool. During the winter awakening, the glutamic acid pool rose above the summer level; The pool of alanine fell below the summer level, but their total level did not change. The pools of aspartic acid and glycine decreased in parallel with the decrease in pools of glutamate and aspartate, but during the winter awakening, glycine was not even detected. Taking into account the participation of glutamic acid and aspartate in the anaplerotic reactions of the Krebs cycle and the reciprocal relationship of glutamic acid and alanine, it is concluded that the change in the content of these metabolites at different stages of bouts is associated with a gradual transition of aerobic glycolysis (Krebs cycle and oxidative phosphorylation) to anaerobic, and during euthermia, on the contrary, with a return to aerobic.
UNCOUPLING PROTEIN UCP1 EXPRESSION DYNAMICS IN ADIPOSE TISSUES OF THE OUTBRED ICR MICE IN POSTNATAL ONTOGENESIS
Authors: Yakunenkov A. V. , Elsukova E. I. , Natochy I. O.
Published: April 2024

Uncoupling protein (UCP1) uncouples mitochondrial respiration from ATP synthesis, resulting in heat production in brown and beige adipocytes. The presence of adipocytes with UCP1 expression in fat depots has been shown to promote metabolic health and provide protection against metabolic disorders. It stimulates interest in studying the age dynamics of UCP1 expression. There are few data available, mainly obtained on the C57Bl/6J mouse line predisposed to obesity and cover either early or late ontogenesis. In our study, for the first time, the expression of the UCP1 protein in the adipose tissues of male ICR mice was studied from the weaning to old age. Interscapular brown adipose tissue (BAT), inguinal and perigonadal white adipose tissue (IWAT and GWAT) of 20-day, 1.5, 6, 18 months mice were collected. UCP1 levels were detected by western-blotting. IWAT UCP1 expression decreased by 2 times between 20 days and 1.5 months. No UCP1 bands on blots from mice older than 1.5 months were observed. In gonadal depot UCP1 was detected only in 30% of the samples from 1.5- and 6‑months old mice, and UCP1 expression level was ten times lower in compare to inguinal depot. No statistically significant changes in UCP1 protein expression were detected in brown adipose tissue. The physiological role of UCP1-expressing cells in GWAT is discussed, as well as a possible relationship between the timing and rate of UCP1 expression decrease during the growth and maturation of reproductive function with the activation of lipogenesis in inguinal adipose tissue.
STRUCTURE AND PROPERTIES OF THE GLOMERULAR FILTRATION BARRIER OF VERTEBRATES: ROLE OF CHARGE FOR FILTERING PROTEINS
Authors: Balbotkina E. V. , Kutina A. V.
Published: April 2024

The renal glomerulus is a unique structure that distinguishes the nephrons of vertebrates from the nephridia of invertebrate animals, providing a direct connection between the circulatory and excretory systems and the most effective control of the composition of the internal environment due to the significant intensification of filtration. The modern ideas about the structure of the glomerular filtration barrier in representatives of all major groups of vertebrates (cyclostomes, fishes, amphibians, reptiles and birds, mammals) were reviewed. Emphasis is placed on the role of the charge of the glomerular barrier structures for its selective properties; approaches to studying the contribution of the anionic components of the renal filter to preventing the loss of plasma proteins are described. The main models of the glomerular filter functioning presented in the literature are considered. Negative charge has been demonstrated to be a distinctive feature of the glomerular filter in all vertebrates. It was shown that a multiple increase of the glomerular filtration rate (from lower vertebrates to birds and mammals) was accompanied by a number of structural changes that ensured the passage of a significant volume of water and dissolved low-molecular substances through the glomerular filter: an increase in the number and ordering of fenestrae in the endothelium of glomerular capillaries, thinning of the glomerular basement membrane and complete exclusion of cellular elements from it. It has been shown that comparative physiological data on the glomerular filter in different groups of vertebrates most strongly confirm the electrokinetic model of the glomerular filtration, since it explains the importance of the evolutionarily conservative structure of podocytes and the role of a set of fixed anionic charges in the filter wall to prevent the loss of macromolecules (primarily proteins) from blood at different intensities of the ultrafiltration.
SOME COMPONENTS OF THE SEROTONERGIC SYSTEM IN THE EYES OF TWO SPECIES OF FRESHWATER MOLLUSCS
Authors: Dominova I. N. , Husenova A. A. , Kotova V. V. , Sidorova M. V. , Zhukov V. V.
Published: April 2024

Labeling of 5-HT-immunoreactive structures was performed on eye slices of freshwater molluscs Lymnaea stagnalis and Pomacea canaliculata. In the periocular region of both species an increased density of 5-HTergic fibers forming structurally distinct plexuses and partially penetrating into the retina was detected. Transcription of serotonin receptor genes was detected in eye tissues: two types in L. stagnalis and three in P. canaliculata. Its relative level is significantly upregulated compared with central ganglia of the nervous system and tentacles. Additionally transcription of the 5HT transporter gene was recorded in P. canaliculata tissues.The obtained results are discussed in terms of a possible serotonergic mechanism of modulation of processes in the retina of gastropods.
Physical and Chemical Properties of Water in the Cytoplasma of Plant Cells
Authors: Gall’ L. N. , Kuleshova T. E. , Gall’ N. R. , Berdnikov A. S. , Gall’ I. R.
Published: April 2024

A study is performed of the physicochemical properties of the aqueous component of the cytoplasm of a living cell and the intercellular fluid associated with their structural organization. As a single coherent system, the structure of the water component of a plant plays a crucial role in its water regime, and therefore determines the development and adaptability of the plant to environmental conditions. Low-frequency L-dielcometry is used for the first time in experimental studies of the water regime of plants. The change in the peak intensities in the spectrum of the dependence of the dielectric loss tangent on the EMF frequency under conditions of artificial drought for different phytotest objects is used to show there are two types of water in living plants: free and self-organized bound. Free water is responsible for the mode of evaporation, while bound water participates in the organization of a complex network of intercellular communications, including the transmission of different signals through putative synapse-like contacts. Results correlate fully with others from plant phytomonitoring with pulsed NMR at the Kazan Scientific School of Phytophysiologist. The conclusion that there are two types of water in a living plant simultaneously is substantiated theoretically on the basis of generalized crystallography using Bulienkov’s modular computer design. It is the most important component of the concept of quantum bioenergetics.
N. A. Bulienkov’s Simplicial-Modular Design As a Basis for Modeling Metal Clusters
Authors: Tytik D. L.
Published: April 2024

The author considers the main principles of Bulienkov’s simplicial-modular design of metal clusters (face-centered cubic (FCC), body-centered cubic (BCC), hexagonal close-packed (HCP) metals). Models of clusters are presented along with algorithms for their construction based on operations of twinning (1¯1¯, 2, m) to simplices and modules of the corresponding metals.
Formation of Formic Acid and Its Esters in Oxidation of Fatty Acid Methyl Esters
Authors: Savel'ev E. A. , Cherepanova A. D. , Sapunov V. N.
Published: April 2024

Pathways of formation of low-boiling products in the course of oxidation of fatty acid methyl esters with atmospheric oxygen in a bubbling column were studied. These products are continuously removed from the reactor under the action of high temperature at continuous air supply. Two kinds of feedstock with different content of esters of mono- and diunsaturated fatty acids (methyl esters of fatty acids of olive and sunflower oils) were used in the study. Along with acids and aldehydes forming the major fraction of low-boiling products, compounds containing ester groups were detected. The 1Н and 13С NMR analysis revealed the presence of formic acid esters in the samples. The formate formation mechanism involving the Baeyer–Villiger reaction of aldehydes with hydroperoxides in the reaction volume was suggested.
Esters of Inulin and Tall Oil Fatty Acids
Authors: Kurzin A. V. , Evdokimov A. N. , Il'ina N. S.
Published: April 2024

The possibility of obtaining polysaccharide esters based on large-scale products of plant origin: inulin and tall oil fatty acids, was studied. Carbohydrate esters of the biopolymer inulin and higher unsaturated acids were synthesized by acylation with acid chlorides under various conditions: in a water–chloroform mixture in the presence of sodium hydroxide and sodium salts of tall oil fatty acids, as well as in a pyridine–1,4-dioxane mixture. The yield of polysaccharide esters was 67–82%, the maximum yield was detected during the acylation of inulin in the pyridine–1,4-dioxane system
Treatment of Phosphorus-Containing Raw Materials with Alkaline Solutions
Authors: Skachkov V. M. , Pasechnik L. A. , Medyankina I. S.
Published: April 2024

The work describes a method for recovery of phosphorus compounds from phosphorus-containing raw materials. The possibility of autoclave leaching of phosphorus from phosphorite in the form of a solution of sodium phosphates with an alkaline solution was experimentally tested. The optimal process parameters were determined (temperature 250–300°C, leaching time 3 h, NaOH concentration 150–300 kg m–3), under which calcium silicate with a unique nano-sized needle-shaped structure, widely used in many industries, is formed in the solid residue. The research results make it possible to involve raw materials with low phosphorus content in waste-free processing.
Neodecanoic Acid Diamides as Inhibitors of Acid Corrosion of Low-Carbon Steel
Authors: Bondareva S. O. , Abdullin M. F. , Nugumanov T. R.
Published: April 2024

Neodecanoic acid diamides were prepared by a simple one-step procedure involving condensation of neodecanoic acid with diethylenetriamine, triethylenetetramine, and pentaethylenehexamine. The inhibiting effect of these diamides on the corrosion of St3 low-carbon steel in 2 М H2SO4 and in 1 and 5 М HCl was studied gravimetrically. All the compounds synthesized efficiently inhibit the steel corrosion with the degree of protection at room temperature of 94–95% in 2 М H2SO4 and 96–97% in 1 М HCl.