bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of the Content of Nutrients in Agrochernozem during the Cultivation of Ginger Seed
Authors: Kurachenko N. L. , Ulyanova O. A. , Vlasenko O. A. , Kazanov V. V. , Kazanova E. Yu.
Published: April 2024

In the field experiment, the food regime of agrochernozem was studied during the cultivation of the seed ginger (Camelina sativa (L.) Crantz) in the conditions of the Kansk forest-steppe of the Krasnoyarsk Territory. The predominant absorption and removal of nitrate nitrogen and exchangeable potassium by the culture determined the low availability of  0–40 cm of mineral nitrogen in the soil layer (5–6 mg/kg) while maintaining an average and very high availability of exchangeable potassium (87–158 mg/kg). It is shown that the largest share of the return to the soil after harvesting the ginger was accounted for by N and P (50–37%). With root and crop residues, nitrogen – 70, phosphorus – 19 and potassium – 51 kg/ha were returned to the soil. Agrochernozems of the Kansk forest-steppe, without additional fertilization, are able to provide a sufficient level of phosphorus and potassium nutrition in ginger crops.
Effect of Amorphous Silicon Dioxide on Productivity and Quality of Tomato
Authors: Bocharnikova Е. А. , Кasatskii А. А. , Мatichenkov В.В.
Published: April 2024

Tomatoes are one of the most popular vegetables, improving their taste and biochemical quality is possible as a result of reducing the content of nitrates and increasing the sugar content. The effect of amorphous fine silica on the productivity and quality of tomatoes was studied in vegetation experiments. Silica was introduced into a mixture of gray forest soil and washed sand in doses of 0.1, 0.2 and 0.3 g/vessel, which corresponded to 100, 200 and 300 kg/ha, against the background of complex mineral fertilizers. It was shown that the improvement of silicon nutrition of tomatoes significantly increased their yield by 52–70%. There was also an improvement in fruit quality as a result of a 20–40% reduction in nitrate content and an increase in sugar content by 12.9–50.9%. Statistical analysis of the obtained data revealed that the concentration of monosilicon acid in soils treated with silicon dioxide was closely positively correlated with the yield of tomatoes, as well as the sugar content in fruits and negatively correlated with the content of nitrates.
Influence of Silicon-Containing Agro-Ore (Diatomite) on the Yield of Agricultural Crops and the Quality of Crop Production
Authors: Kuzin E. N. , Arefyev A. N. , Kuzina E. E.
Published: April 2024

In the soil and climatic conditions of the forest-steppe of the Middle Volga region, the effect and aftereffect of various doses of silicon-containing agro-ore (diatomite) and its combinations with bird droppings on the productivity of agricultural crops has been scientifically substantiated and experimentally proven. The highest effect on the productivity of corn, spring wheat, annual grasses was provided by the complex action and aftereffect of silicon-containing agricultural ore together with bird droppings. The yield of corn grain in these variants varied from 5.48 to 5.92, spring wheat – from 3.12 to 3.33, hay of annual grasses – from 9.15 to 10.2 t/ha. The total productivity of crops of the grain-to-crop rotation link when using silicon-containing agricultural ore (diatomite) mixed with bird droppings varied in the range from 13.0 to 14.1 tons of grain/ha, exceeding the control by 3.36–4.44 tons of grain/ha, or by 34.8–45.9%.
Laboratory Simulation of Photosynthesis in a Wide Range of Electromagnetic and Radiation Environment Parameters
Authors: Grinberg M. A. , Vodeneev V. A. , Il’in N. V. , Mareev E. A.
Published: April 2024

The problem of studying the limits of stability and mechanisms of adaptation of living systems to environmental parameters that vary over a wide range is briefly analyzed. The main attention is focused on the analysis of the electromagnetic environment and background radiation. These factors vary relatively little on the modern Earth, which leads to their insufficient knowledge. At the same time, they present serious challenges for future space missions. One of the main methods for studying the influence of such factors on living organisms is laboratory simulation. Previous experiments have demonstrated the need to develop a new laboratory setup, the requirements for the parameters of which are presented in this paper. In general, the setup will have a high potential for solving the problems of modeling the effect of astro-geophysical factors on the physiological state of living organisms and, in particular, the activity of photosynthesis in higher plants. The implementation of the proposed program of laboratory simulation experiments will allow us to advance in understanding the problems of life evolution, the mechanisms of the possible influence of solar activity on the biosphere, and studies of the role of the biosphere in global climate changes of planets at various time horizons.
Numerical MHD Simulation of Laboratory Jets in a Toroidal Magnetic Field
Authors: Toropina O. D. , Bisnovatyi-Kogan G. S. , Moiseenko S. G.
Published: April 2024

The results of MHD modeling of the formation and collimation of laboratory jets with a toroidal magnetic field are presented. We showed that in the absence of a magnetic field, a significant expansion of the jet occurs in the computational region. In the presence of a strong toroidal magnetic field, the jet expands insignificantly, which confirms the possibility of a magnetic mechanism of collimation of astrophysical jets. The opening angle of the jet cone depends on the magnitude of the magnetic field induction. The larger Bϕ, the smaller the angle of deflection of the flow. For certain values of Bϕ on the detector, the occurrence of ring structures in the density distribution is possible, the characteristics of which depend on the magnitude of the field. The simulation results are compared with the laboratory jets generated in the experiment at the Neodim laser facility and with the previously obtained results of the MHD simulation of the formation of jets in a poloidal magnetic field.
On the Evolution of Angles between the Magnetic Moment and the Axis of Rotation in Radio Pulsars
Authors: Malov I. F. , Malov O. I.
Published: April 2024

Three methods were used to calculate the angles β between the magnetic moment and the axis of rotation of central neutron stars for 307 known radio pulsars. There is no explicit statistical dependence of the calculated angles β on the kinematic age of pulsars. It follows from this that either the indicated angle does not change noticeably with the age of the pulsar, or pulsars are born with an arbitrary inclination angle.
Observations of Hydroxyl in the Onsala 1 Source at 18 cm
Authors: Ashimbaeva N. T. , Lekht E. E. , Krasnov V. V. , Tolmachev A. M.
Published: April 2024

We present results of polarization observations of the ON 1 source in the 1665, 1667, and 1612 MHz hydroxyl lines at the Large Radio Telescope in Nançay (France). Spatial identification of the spectral features of OH in the 1665 and 1667 MHz lines with maser spots (condensations) on the VLBI map according to the data of Fish et al. (2005) was carried out. Emission from hitherto unknown spectral features in the 1665 MHz main line at radial velocities of –2.98, 9.35, and 11.8 km/s has been detected. Five Zeeman pairs were found: four in the 1665 MHz line and one in the 1667 MHz line. The vectors of the transverse magnetic field H⊥ are oriented mainly along the arc (in the upper and lower parts of the UC H II region), while the vectors of the longitudinal magnetic field H|| in the northern and central parts of the UC H II region are oriented away from the observer, while in the southern part toward the observer.
3D Numerical Model of the Envelope of a Hot Exoplanet Based on Spherical Coordinates
Authors: Zhilkin A. G.
Published: April 2024

A new 3D parallel numerical code in spherical coordinates has been developed to study the stellar wind flow around hot Jupiter. The peculiarity of the spherical coordinate system in the vicinity of the poles is overcome by using a ternary spherical grid, which is a composite grid consisting of three separate sectors. The numerical model of multicomponent magnetohydrodynamics, developed earlier for Cartesian coordinates, has been transferred to the new model. The results of a numerical calculation of the structure of an extended envelope of a quasi-open type for the case of a super-Alfvenian flow around a hot Jupiter are presented. We showed that the spatial resolution of the grid is sufficient for a self-consistent calculation of the structure of the atmosphere of a hot Jupiter. This allows further use of the new model for 3D aeronomic calculations.
Effect of Dust Evaporation and Thermal Instability on Temperature Distribution in a Protoplanetary Disk
Authors: Pavlyuchenkov Ya. N. , Akimkin V. V, , Topchieva A. P. , Vorobyov E. I.
Published: April 2024

The thermal instability of accretion disks is widely used to explain the activity of cataclysmic variables, but its manifestation in gas and dust disks in young stars has been studied in less detail. A semi-analytical stationary model is presented for calculating the equatorial temperature of a gas and dust disk around a young star. The model considers the opacity caused by dust and gas, as well as the evaporation of dust at temperatures above 1000 K. Using this model, the distributions of the equatorial temperature of the gas and dust disk are calculated under various assumptions on the source of opacity and the presence of dust. It is shown that when all the above processes are considered, the thermal balance equation in the region r1 AU has multiple temperature solutions. Thus, the conditions for thermal instability are satisfied in this region. As an illustration of the possible influence of instability on the nature of accretion in a protoplanetary disk, we consider a viscous disk model with α-parametrization of turbulent viscosity. It is shown that in such a model a non-stationary mode of disk evolution is realized with alternating phases of accumulation of matter in the inner disk and phases of its rapid accretion onto the star, which leads to a burst character of accretion. The results obtained indicate the need to take this instability into account when modeling the evolution of protoplanetary disks.
MILESTONES IN THE DEVELOPMENT OF CELESTIAL MECHANICS
Authors: Kondratyev B. P.
Published: April 2024

A brief outline of the development of ideas and a review of some achievements in modern celestial mechanics are given. The emphasis is on the fact that the classical definition of this science given by Laplace does not fully reflect the content of modern celestial mechanics, and the term dynamic astronomy is more capacious. Dynamic astronomy studies almost everything that moves and rotates in space: from dust particles to comets and asteroids, from satellites, planets and their satellites to stars and galaxies. This complex science includes not only the problems of classical, but also relativistic celestial mechanics, it includes the theory of equilibrium figures, various computational methods and computer simulation methods. Qualitative methods are of great importance, the culmination of which was the creation of the KAM theory. The development of celestial mechanics went through the practice of various applications, and the range of problems in it is exceptionally wide. A striking stimulus for the development of dynamical astronomy was the discovery of exoplanets around other stars. The article traces a chain of ideas from Keplerian orbits to osculating Lagrangian ellipses, from two-body problems to many-body problems, from Gaussian rings to models built on the basis of precessing analogues of these rings.
NEUTRON STARS IN A UNIFORM DENSITY APPROXIMATION
Authors: Bisnovatyi-Kogan G. S. , Patraman E. A.
Published: April 2024

Models of neutron stars are considered in the case of a uniform density distribution. A universal algebraic equation is obtained that is valid for any equation of state. This equation allows us to find the approximate mass of a star of a given density without resorting to the integration of differential equations. Solutions for various equations of state, including more realistic ones, are presented in the paper and differ from the exact solutions obtained by numerical integration of differential equations by no more than 20%.
MODIFIED SHAO SPECTROGRAPH FOR SPECTRA WITH LOW RESOLUTION
Authors: Ismailov N. Z. , Alyshov S. A. , Ismailova Sh. K. , Huseynova F. S.
Published: April 2024

The paper describes an improved spectrograph of the Cassegrain focus of the 2 m ShAO reflector using a CCD camera. The classic Universal Astro Grid Spectrograph (UAGS) was adapted to use the Andor CCD camera to obtain spectra of objects with low brightness in the range of 3600–8000 Å. A spectrograph with a diffraction grating of 651 line/mm makes it possible to obtain the spectra of stars on the 2 m ShAO telescope up to 18 mag with a resolution of 1200, with a signal-to-noise ratio of about 50 for half an hour of exposure. The maximum allowable resolution is R = 3400 with binning 1 × 1. The complex can be used for observations of various types of transient objects, variable stars, and extragalactic objects.
CALIBRATING GAIA DR3 UNCERTAINTIES BASED ON DATA FOR WIDE BINARY STARS OF THE FIELD OF GALAXY
Authors: Kovaleva D. A.
Published: April 2024

We use the catalog of wide binary stars [1], created on the basis of Gaia EDR3 and including more than a million pairs, to analyze Gaia DR3 data independently obtained for the components of the pairs. It is shown that the spatial heterogeneity of the catalog reflects the Gaia scanning law. The change in the spatial density of binary stars of the catalog with increasing distance from the Sun is investigated. By comparison with the model distribution, it is shown that the catalog contains approximately 2.5 times fewer binary stars than would be expected without spatial incompleteness. It is confirmed that the radius of spatial completeness of the catalog is on average close to 200 pc and depends on the absolute magnitude of the main component. The spatial density of binary stars in the catalog mildly depends on the difference in the stellar magnitudes of the components, and significantly depends on the physical distance between the components. The incompleteness of the catalog in relation to pairs with a distance between components less than 100 AU occurs already at a distance of 25 pc from the Sun. A comparison of the characteristics of components of the same pair independently determined within the Gaia DR3 catalog allows us to investigate how the probability of a non-random combination of components is related to the proximity of their characteristics. A high degree of correlation of the degree of agreement of the characteristics with the reliability of the pair is found for radial velocities. Qualitative agreement is observed for the metallicity estimates of [Fe/H] and, to a lesser extent, for the absorption estimates of \({{A}_{G}}\). No agreement was found for the ages of the stars, which indicates their significant uncertainty in the dataset consisting mainly of main sequence stars. At the same time, age estimates for pairs with evolved components show noticeably better agreement than for the dataset as a whole. Using the parameters of the components of pairs from Gaia DR3, an independent estimation of the uncertainties of the values of radial velocities and metallicities depending on the apparent magnitude G of the sources was performed. Estimates of probable median values of radial velocity errors and metallicity of Gaia DR3 sources are proposed. Depending on the apparent magnitude, they exceed the median values of errors given in the catalog: for radial velocities by 1.5–3 times, for metallicity [Fe/H] by 7–25 times. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.
DARK MATTER HALOS IN NUMERICAL MODELS AT REDSHIFTS 0 ≤ z ≤ 9
Authors: Demyanskii Marek , Doroshkevich Andrei , Larchenkova Tatiana , Pilipenko Sergey
Published: April 2024

For the numerical model in the range of redshifts \(0 \leqslant z \leqslant 9\), we examined the properties and evolution of dark matter haloes using a previously proposed method of compact analysis that allows separating the influence of random and regular factors on the main characteristics of the dark matter halo. In the investigated range of redshifts, a monotonic evolution of the average values of the basic parameters of small halo structures into a central massive object is observed through sequential hierarchical merging. These basic parameters include the circular velocity \( {{{v}}_{c}} \), the parameter \( {{w}_{c}} = {{{v}}_{c}}{\text{/}}r \), and the mass. In the range \(3 \leqslant z \leqslant 9\), the parameters evolve slowly, while in the range \(0 \leqslant z \leqslant 3\), they evolve rapidly. The evolution of the dark matter halos formed before reionization is characterized by a slow change in their average characteristics and the properties of the halo outskirts. The important role of early-formed massive structural elements is emphasized.
ACTIVITY CYCLES OF FK COM
Authors: Savanov I. S , Naroenkov S. A. , Nalivkin M. A. , Dmitrienko E. S.
Published: April 2024

New results of photometric observations of the chromospherically active star FK Com (a prototype of the group of the same name) performed during the past 5 years (2018–2023) at the INASAN observatories in Zvenigorod, Simeiz Observatory INASAN and Russian–Cuban Observatory in Havana, Republic of Cuba, are presented. In total during this observation interval we obtained 9060 estimates of the brightness of the star in V band. Our measurements as well as data from the literature and from the Kamogata Wide-field Survey (KWS) archive were combined into the array comprising 17 653 measurements in an interval of about 57 years. Based on the power spectrum constructed from these data, P values of the cycle activity have been established, which according to our estimate are equal to 2.4, 5.63, 8, 13.6, 30 and 49 years. The dominant is the P cycle lasting 5.63 years. It is shown that this dominant cycle with a period of about 5.63 years found by us according to more extensive data (5.4–5.8 years in other sources) can be traced in the results of the analysis of previous studies. The results on the activity cycles of FK Com are compared with data on the long-term variability of two more stars of the type under consideration – HD 199178 (V1794 Cyg) and ET Dra. Based on the data on the P cycle of other chromospherically active stars (according to literature sources and our measurements) a diagram \(\log (1{\text{/}}{{P}_{{{\text{rot}}}}}){\kern 1pt} - {\kern 1pt} \log ({{P}_{{{\text{cycl}}}}}{\text{/}}{{P}_{{{\text{rot}}}}})\) is analyzed. The conclusion about the comparability of the values of the activity cycles of the FK Com type stars with the data for stars of the RS CVn type is made.
Alteration of enzyme-substrate interactions by ultra-high dilutions of the substrate
Authors: Lomakina G. Yu , Ugarova N. N
Published: April 2024

The effects of different ultra-high dilutions of luciferin ranged from 1010 to 10102 on luciferin-luciferase reaction of fireflies were investigated. Luciferin substrate concentration varied from 0.0025 nM to 2.5 nM and ATP concentration remained unchanged. This study evaluated the bioluminescence intensity after addition of ultra-high dilutions of luciferin or ultra-high dilutions of water to the bioluminescent system and some multidirectional and significant differences were found. The number of ultra-high dilutions from studied starting materials, for which significant differences were found, increased sharply with decreasing substrate concentration to 0.0025 nM. No differences were found when the effects of ultra-high dilutions of a non-specific control imidazole and ultra-high dilutions of water on the signal intensity were compared. Our results suggest that ultra-high dilutions of luciferin can specifically inhibit the luciferin-luciferase reaction.
On the use of Kolmogorov equations for determining ion channels characteristics
Authors: Kruchinina A. P , Kulikovskaya N. V
Published: April 2024

The paper proposes a method for determination of the dynamic properties of conduction within voltage-gated ion channels with several sequentially located energy barriers named gate particles using a theory of Markov random processes in continuous time and with a discrete state space. The number of states was taken equal to the number of energy barriers in the channel plus one. If the hypothesis that random flows switching gate particles between an open and a closed are Poisson process, is true, then mathematical description of the system’s state of similar channels can be a system of Kolmogorov linear differential equations for state probabilities. Using this model and based on Volt-Clamp test results, published in open access journals, it is possible to find out how fixed values of membrane potential depend on the intensities of Poisson process for different types of potassium channels. Function parameters, that describe the intensity of ion transition across the channel, in the Kolmogorov equation can be restored using the generalized least squares method. This paper contains the examples of determining the intensities of transitions for two types of voltage-dependent potassium channels known as «delayed rectifiier potassium channels» (IKdr, two identical activation gate particles) and channels with fast activation and inactivation processes (IKa, three identical activation and one inactivation gate particles). It is shown that channel activation and deactivation is described by solving the general Kolmogorov equation.
Agar freezing solution for long-term cryopreservation of brain slices from non-hibernating animals
Authors: Mokrushin A. A
Published: April 2024

Our previous studies have shown that function of ionotropic glutamate receptors such as AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid) and NMDA (N-methyl-D-aspartate) was impaired after long-term cryopreservation of brain slices at -10°C within 30-50 days. To elucidate the reasons for cryodamage to AMPA- and NMDA-dependent mechanisms, artificial cerebrospinal fluid (aCSF) solutions that contain agar at different concentrations (33, 44, and 50%) were used for cryopreservation of the rat olfactory cortex slices. After cryopreservation, the slices were warmed to 37°C and the amplitudes changes of AMPA and NMDA potentials, which reflected the activities of the AMPA and NMDA mechanisms, were evaluated; the results were compared with those obtained before cryopreservation. It was found that AMPA and NMDA potentials changed differently depending on the concentration of agar in artificial cerebrospinal fluid. In solutions with 33% agar, the amplitude of AMPA potentials increased by 60%, whereas, in contrast, the amplitude of NMDA potentials was equal to the values before cryopreservation. At agar concentration of 44% in the solution, the AMPA and NMDA amplitudes were increased by 70% and 80%, respectively. A complete recovery of the activities of AMPA and NMDA mechanisms was obtained after cryopreservation in a freezing solution with an agar concentration of 50%. Under these conditions, the amplitudes of the AMPA and NMDA potentials corresponded to those seen before cryopreservation. Thus, the results obtained indicate that agar added to the artificial cerebrospinal fluid solution is a cryoprotectant that protects AMPA- and NMDA-dependent mechanisms from cryoinjury. The freezing solution (artificial cerebrospinal fluid and agar) developed by us for cryopreservation of brain explants of non-hibernating animals will be used to create a cryobank of nervous tissue.
Single SARS virus mutation as a possible cause of the prevalence of asymptomatic COVID-19 infection forms
Authors: Kolesin I. D , Zhitkova E. M
Published: April 2024

To explain the prevalence of asymptomatic SARS-CoV-2 infection forms, a hypothesis on a single virus mutation that causes changes in two important factors such as virus infectiousness and pathogenicity is proposed. According to this hypothesis, susceptible and asymptomatic forms affect the rate of change in infectiousness and pathogenicity, thereby influencing the rate of infectivity and the onset of a disease and as a result, altering the ratio of asymptomatic forms to symptomatic cases. With a mathematical model, constructed based on this hypothesis and identified using data from the first wave of COVID-19 in Saint-Petersburg, a correlation between changes in microbiological parameters of the model and changes in a ratio of asymptomatic forms to symptomatic cases is verified. It is concluded that single virus mutation may affect the ratio.
Kinetics and mechanism of inhibition of horseradish peroxidase activity by N-phosphonomethyl-glycine
Authors: Avdeeva L. V , Vakhterova Ya. V , Saratovskikh E. A
Published: April 2024

The inhibition of horseradish peroxidase activity by N-phosphonomethyl-glycine, an active ingredient in the most extensively used glyphosate-based herbicide (Roundup) in agricultural applications worldwide, was investigated. It has been shown that N-phosphonomethyl-glycine inhibits the activity of peroxidase from horseradish roots. This inhibition is of a competitive nature, the value of Ki = 0.1004 mM. The Michaelis constant (Km = 0.1776 mM) and herbicide concentration (I50 of Roundup = 0.302 mM) were determined. The results demonstrate that N-phosphonomethyl-glycine can suppress the activity of the antioxidant system, and in warm-blooded organisms it may cause the accumulation of free radicals, thereby contributing to expanding knowledge of biological targets Roundup is applied to.
Peculiarities of oligomerization of smooth muscle titin and skeletal myosin-binding protein C
Authors: Bobyleva L. G , Timchenko M. A , Yakupova E. I , Vikhlyantsev I. M , Bobylev A. G
Published: April 2024

Protein oligomers are important intermediates in the formation of amyloid fibrils. In amyloidoses, for instance, in Alzheimer's disease, oligomers are able to exert toxic effects on cells. This paper describes the distinctive features of oligomerization of multidomain muscle proteins such as smooth muscle titin and myosin-binding protein C (MyBP-C) of skeletal muscles, which consist of FnIII-like and IgC2-like domains and form amorphous amyloid aggregates in vitro. MyBP-C at low ionic strength (below physiological values) formed stable oligomers that did not participate in further aggregation. In high ionic strength conditions (µ ~ 0.6), smooth muscle titin formed oligomers, which were precursors of amyloid amorphous aggregates of this protein. The results obtained help expand existing knowledge about the process of protein aggregation.
On the interaction of resveratrol with nucleosomes
Authors: Maluchenko N. V , Andreeva T. V , Geraskina O. V , Gerasimova N. S , Lubitelev A. V , Feofanov A. V , Studitsky V. M
Published: April 2024

The natural polyphenol resveratrol has anti-inflammatory, antioxidant, antitumor and geroprotective properties. The wide range of resveratrol activities is determined by its ability to modulate a variety of signaling pathways in the cell and interact with various target molecules. It is known that resveratrol interacts with DNA, but the effect of this interaction on the structure of chromatin has not been studied. In this work, we studied the effect of resveratrol on the structure of the nucleosome, the functional and structural unit of chromatin. Fluorescent microscopy of single nucleosomes based on Forster resonance energy transfer and analysis of changes in the electrophoretic mobility of nucleosomes in polyacrylamide gel showed that, at a concentration of ~100 μM, resveratrol affects the conformation of DNA linker regions, limits the conformational dynamics of DNA near the nucleosome boundary, but does not cause significant changes in the folding of nucleosomal DNA on the histone octamer. A small effect of resveratrol on the structure of the nucleosome compared to quercetin is presumably determined by the binding mode of resveratrol in a minor groove of DNA.
Ektacytometry: characterization of the erythrocytes of rats subjected to hypothermia and receiving natural zeolites
Authors: Vokhmintsev A. P
Published: April 2024

The article presents data as to the effect of a diet containing natural zeolite, taken from the Mysovsky mine (Khanty-Mansi Autonomous Okrug - Ugra), and applied in powdered form on the ability of erythrocytes of white outbred rats to change their shape in shear flow under normal and hypothermic conditions. To assess the deformability of erythrocytes, a laser diffraction technique combined with a redesigned version of the ektacytomer has been used in this work. For comparison, zeolite from the Kholinsky mine (Zabaykalsky Krai), which is well-studied and widely used for medicines and nutraceuticals has been provided. It has been shown that hypothermia causes a significant increase in the parameter such as erythrocyte deformability in rats in a cold group and is associated with enhanced lipid peroxidation when compared to animals in a control group. These alterations were a result of macrocytosis, revealed by flow cytometry analysis. Natural zeolite powder used in animal feeds had antioxidant and membrane-protective effects on animals in both groups. These included a significant increase in the parameter such as erythrocyte deformability with a decrease in lipid peroxidation processes and expansion of the Price-Jones curve to the left, unlike those observed in animals subjected to hypothermia but not receiving zeolites. The results obtained demonstrated that the biological effects of natural zeolite-containing preparation which contains a clinoptilolite component are similar and that zeolites from the Mysovsky mine can be used as a potent raw material for drugs.
The effect of acute phase proteins on the activity of peripheral blood neutrophils
Authors: Fedorova N. D , Sumbatian D. A , Sokolov A. V , Filatov M. V , Trashkov A. P , Varfolomeeva E. Yu
Published: April 2024

Neutrophils are the leading cells of the innate immune system and the main population of leukocytes responsible for the primary reaction of the organism to various infectious agents. The latter are destroyed by neutrophils during the processes of phagocytosis and a cascade of reactions, including the respiratory burst. As a result of the respiratory burst, neutrophils produce reactive oxygen and halogen species, which are powerful cytotoxic agents which destroy foreign particles in the phagolysosome. All of these processes require strict regulation, since excessive activation of neutrophils may lead to higher production of reactive oxygen species thereby causing tissue damage in the focus of inflammation. Acute phase proteins may play a role as regulators of inflammatory processes. Our previous works have shown that ceruloplasmin is involved in the inhibition of the respiratory burst of neutrophils in whole blood samples. Fibrinogen, on the contrary, increased the intensity of respiratory burst. A detailed characterization of the effects acute phase proteins exert on peripheral blood neutrophils’ functions has been studied not for all acute phase proteins and especially their combinations. In this paper, for the first time, the flow cytometer and registration of reactive oxygen species production in peripheral blood cells have been used to study the effects of several acute phase reactants (C-reactive protein, serum amyloid A, alpha-1-acid glycoprotein and fibrinogen) on the ability of peripheral blood neutrophils to activate respiratory burst. The results showed that significant changes in the capacity of reactive oxygen species production by neutrophils were seen for a set of combinations of the studied acute phase proteins. The study of the interaction of ceruloplasmin and fibrinogen with peripheral blood neutrophils revealed that they were localized to the membrane. It seems promising to identify receptors for acute phase proteins at the neutrophil membrane.
A pathogenetic role of posttranslational isoforms of uromodulin
Authors: Iakovleva A. V , Vertov N. A , Zaleskiy M. G , Landa S. B , Shapovalov V. V , Emanuel V. L
Published: April 2024

Different biophysical techniques were used to study uromodulin isoforms using experimental models of urine formation (ionic composition, osmolality, pH) in the presence of intact uromodulin and its isoforms isolated from patients with urolithiasis. A model of a medical screening device for persons with preclinical urolithiasis was tested. The concept of targeted therapy of urolithiasis based on the modulation of the properties of uromodulin was put forth.
Kinetics and mechanisms of oxidative hemolysis of erythrocytes in the presence of azoand peroxide initiator
Authors: Sokolova E. M , Dubenskaia N. A , Psikha B. L , Neshev N. I
Published: April 2024

The kinetics of oxidative hemolysis of a 0.2% suspension of mouse erythrocytes in the presence of radicalforming initiators, 2,2'-azobis(2-amidinopropane) dihydrochloride and tert-butyl hydroperoxide, was studied over a wide range of concentrations. Hemolysis of erythrocytes proceeded with the activation of lipid peroxidation in erythrocyte membranes. In the case of tert-butyl hydroperoxide, oxidative processes also developed in the soluble part of the cell, leading to the formation of insoluble hemoglobin aggregates. An induction period of hemolysis (the time period required to reach 10% hemolysis) in the presence of 2,2'-azobis(2-amid-inopropane) dihydrochloride decreases inversely proportional to the square root of the initiator concentration, that is in accord with the classical theory of radical chain oxidation of hydrocarbons. In the case of tertbutyl hydroperoxide, this association was not found. The use of 2,2'-azobis(2-amidinopropane) dihydrochloride as a lipid peroxidation initiator is preferred in the erythrocyte model for testing natural and synthetic compounds for antioxidant activity.
Quantitative determination of natural rubber content of Taraxacum kok-saghyz E. Rodin plants using spin probe method of electron paramagnetic resonance spectroscopy
Authors: Martirosyan L. Yu , Goldberg V. M , Barashkova I. I , Kasparov V. V , Martirosyan Yu. Ts , Motyakin M. V , Gaydamaka S. N , Varfolomeev S. D
Published: April 2024

The paper presents a method to carry out a quantitative analysis of the content of natural rubber of Taraxacum kok-saghyz E. Rodin by measuring adsorption of the nitroxide radical TEMPO in root preparations of the said plant. The method is based on a comparison between the integrated intensity of an EPR signal of interest and a standard. The developed method of analysis makes it possible to quickly and with good accuracy determine the content of rubber of plant tissues without its extraction from rubber-containing biomass.
In silico study of solvation effects in solutions of biomolecules: possibilities of an approach based on the 3d-distribution of solvent atomic density
Authors: Kruchinin S. E , Fedotova M. V , Kislinskaya E. E , Chuev G. N
Published: April 2024

Biomolecular solvation plays one of the key roles in nature. The biological activity of molecules and the performance of their target functions depend on the features of this process. However, the study of the biomolecule hydration is a non-trivial task for both experimental methods and computer simulations. The paper demonstrates the possibilities of the non-empirical 3D-SDFT/3D-RISM approach based on the 3D-distribution of the solvent atomic density to study the features of biomolecule hydration using the example of a number of amino acids such as Gly-ZW, L-Ala-ZW, L-Val-ZW, L -Pro-ZW, two model proteins such as BP-TI (bovine pancreatic trypsin inhibitor) and PTP1B (protein tyrosine phosphatase 1B), as well as complexes of the PTP1B protein with inhibitors. The presented results show that the approach allows one to describe in detail and at the same time a holistic description of the hydration shell structure of biomolecules.
The effect of molixan, a disulfide-containing immunomodulator, on Na+ transport across frog skin epithelium
Authors: Melnitskaya A. V , Krutetskaya Z. I , Antonov V. G , Krutetskaya N. I
Published: April 2024

The effect of molixan, a disulfide-containing immunomodulator which is an analogue of oxidized glutathione, on Na+ transport across frog skin epithelium has been studied. Using the voltage-clamp technique, the capacity of molixan to modulate Na+ transport across frog skin epithelium has been revealed for the first time. It was also found that when molixan is applied to the apical surface of frog skin, it suppresses Na+ transport, while molixan added on the basolateral surface may mimic the effect of insulin and stimulate Na+ transport. The results obtained indicate that oxidized glutathione and its analogs molixan and glutoxim unidirectionally modulate Na+ transport across frog skin.
The inversion of the inotropic effect of isoproterenol in the rat myocardium during deep hypothermia
Authors: Samodurova C. V , Turin F. V , Averin A. S
Published: April 2024

The present study examined the effects of the в-adrenergic receptor agonist, isoproterenol, on contractile activity of right ventricle papillary muscles in the rat heart at near-physiological temperature (30°C) and under conditions of deep hypothermia (10°C). Isoproterenol exerts a pronounced positive inotropic effect at 30°C. After agonist addition, the force of contraction increases from 1.2 ± 0.1 mN in control to 2.4 ± 0.4 mN that leads to a reliable acceleration of time parameters of contraction. So, time-to-maximum contraction decreased from 101 ± 6 ms to 85 ± 4 ms; time-to-50% relaxation declined from 55 ± 3 ms to 36 ± 1 ms. Under hypothermic conditions, isoproterenol produced a powerful negative inotropic effect, reducing the force of contraction from 2.2 ± 0.4 mN to 1.2 ± 0.4 mN. Similarly as at 30°C, there was a tendency for increase in contraction speed, so time-to-maximum contraction decreased from 717 ± 52 ms to 624 ± 50 ms, and time-to-50% relaxation was shortened from 667 ± 86 ms to 450 ± 40 ms. Thus, under conditions of deep hypothermia at 10°C, the isoproterenol-induced inotropy changes from positive to negative, while negative lusitropic effect remains clear.
On methodological errors in estimating the initial velocities of enzyme-catalyzed reactions and on approaches to their correction(a case study with lactate dehydrogenase)
Authors: Lianguzov A. Yu , Malygina N. M , Petrova T. A
Published: April 2024

A universal algorithm is proposed to compute the initial velocities of enzyme-catalyzed reactions at “zero time” from the kinetic curve for substrate consumption or product accumulation determined by direct measurements of changes in enzyme activities. The research is illustrated with a commercial lactate dehydrogenase sample and a standard biochemical test kit. The proposed approach makes it possible to virtually eliminate systematic errors in measurements, determine the initial velocity with the same accuracy regardless of the levels of enzyme activities, reduce time spent on analysis to one minute, and expand the scope of application of standard test kits for studying enzymes isolated from different sources when solving a wide range of problems. The algorithm cannot be applied to analyses of coupled enzyme reactions because there is a long initial lag phase in respective kinetic curves.
Background formation of lower levels of reactive oxygen species by neutrophils after hypomagnetic field exposure is not accompanied by the impairment of chemiluminescence response of neutrophils to respiratory-burst stimuli
Authors: Novikov V. V , Yablokova E. V , Shaev I. A , Novikova N. I , Fesenko E. E
Published: April 2024

This study shows that the background formation of lower levels of reactive oxygen species in mouse peritoneal neutrophils after short-term (40 minutes) exposure to hypomagnetic fields with ~10 nT residual field at physiological temperatures, which has been detected by use of lucigenin-dependent chemiluminescence, is not accompanied by the impairment of chemiluminescence response of neutrophils to respiratory-burst stimuli: the formylated tripeptide N-formyl-Met-Leu-Phe (fMLF) and phorbol ester phorbol-12-myristate-13-ace-tate (PMA). These results were obtained with lucigenin or luminol-enhanced activated chemiluminescence and various combinations of reactive oxygen species production stimuli (phorbol-12-myristate-13-acetate and/or N-formyl-Met-Leu-Phe). Based on the results of the present work as well as on those of previous studies, this study reveal that the systems that control the respiratory burst in neutrophils can be excluded from a list of main targets and acceptors that respond to short-term deprivation of the magnetic field.
NEW DATA ON VEGETATION AND SOILS OF URUP (KURIL ISLANDS)
Authors: Liksakova N. S. , Glazkova E. A. , Kuzmina E. Yu. , Khokhlov S. F.
Published: April 2024

The article presents new data on the vegetation of the island of Urup (Kuril Islands) obtained during the research of the authors in 2019 and 2021. The characteristics of the main forest communities (Erman’s birch forests, willow forests and Pinus pumila thickets), as well as rock and mire vegetation and vegetation of disturbed habitats, are given. The ecological-phytocenotic classification of the studied communities has been refined or carried out for the first time, the tables of geobotanical descriptions for a number of associations are given. Patterns of vegetation distribution in river valleys are considered. It is shown that in the northern part of the island, in the vegetation cover of the Pacific side, the role of mires and shrub communities increases in comparison with the Okhotsk Sea side. The description of soils is given in connection with the plant communities formed on them. The reasons of the revealed regularities are discussed, in particular, the influence of the relief, cold oceanic winds and fogs on the vegetation cover of the island.
ТИПОВЫЕ И АВТЕНТИЧНЫЕ ОБРАЗЦЫ В ГЕРБАРИИ ВОДОРОСЛЕЙ БИН РАН (LE). III
Authors: Mikhaylova T. A.
Published: April 2024

Статья продолжает серию публикаций о хранящихся в коллекции Ботанического института им. В.Л. Комарова РАН (LE) типовых и автентичных образцах названий водорослей. Собраны сведения об образцах, на которых основаны названия, обнародованные во второй половине XX века советскими и российскими альгологами Кирой Леонидовной Виноградовой, Юрием Евгеньевичем Петровым с соавторами, Александрой Архиповной Калугиной, Валентиной Федоровной Макиенко, Екатериной Ивановной Блиновой и Анной Дмитриевной Зиновой. Хранящиеся в типовой коллекции образцы собраны в российских континентальных, арктических и дальневосточных морях, а также в Тихом и Южном океанах: в Черном (8), Баренцевом (3), Белом (6), Чукотском (1), Беринговом (5), Охотском (5), Японском (12), Филиппинском (2) морях, из районов Курильских (5) и Южно-Шетландских (5) островов. В типовом гербарии хранится 53 образца, относящихся к 32 таксонам, действительно обнародованным вышеперечисленными авторами, в том числе 29 голотипов, 22 изотипа и 1 паратип. Оригинальный материал для трех таксонов (Hammatoidea murmanica Yu.E. Petrov, Rosenvingiella simplex K.L. Vinogr., Undariella kurilensis Yu.E.Petrov et Kussakin) не обнаружен. Также приведены сведения о 2 образцах двух недействительно обнародованных таксонов и 3 образцах двух неопубликованных таксонов. Кроме того, процитированы номера штрих-кодов 190 паратипов, трех оригинальных и одного автентичного образца из основной коллекции.
The “Plant Phylogeny Posters” (PPP) – Useful Tools for Scientific Research and Education
Authors: Godin V. N. , Cole Т. C. H.
Published: April 2024

Wall charts and posters depicting plant structure and evolutionary relationships as phylogenetic trees have been important teaching tools for many decades. With the development of digital technologies, new approaches to the traditional concept have become possible. The article briefly discusses the history, development and significance of the “Plant Phylogeny Posters” project. This project is a joint work of a growing team of more than 200 specialists from more than 50 nations from all around the world. The portfolio currently consists of nearly 600 posters in 54 poster titles and in 45 languages (as of early 2023). All posters are freely available on the Internet and are regularly updated.
New Species of Alien Plants in the Flora of Sakhalin Island
Authors: Lozhnikova O. O. , Sabirova N. D. , Sabirov R. N.
Published: April 2024

Information is provided on 12 newly recorded alien species of vascular plants in the flora of Sakhalin Island: Ajuga reptans L., Brunnera sibirica Steven, Centaurea jacea L., Erodium cicutarium (L.) L’Her., Juncus tenuis Willd., Leonurus quinquelobatus Gilib., Melandrium dioicum (L.) Coss. et Germ., Mentha longifolia (L.) Huds., Myosotis arvensis (L.) Hill, Phacelia tanacetifolia Benth., Veronica filiformis Sm., Vinca minor L. Their localities and habitats are cited, and some features of their distribution on the territory of the island are reported.
Viola Reischenbachiana (Violaceae) – a New Species to the Flora of Central Russia
Authors: Reshetnikova N. M.
Published: April 2024

The discovery of Viola reischenbachiana Jord. ex Boreau in the Kaluga Region is reported. The species is for the first time reliably indicated for the Central Russia. Its morphological differences are discussed. The occurrence in isolation from the main area is apparently due to the drift during the deployment of German troops on the territory of the Kaluga Region.
Structure of Needle Mesophyll in the Genus Larix Species (Pinaceae)
Authors: Zvereva G. K.
Published: April 2024

The structure of needle mesophyll and the forms of assimilative cells in the genus Larix species are discussed on the example of L. gmelini var. gmelini, L. decidua, L. kaempferi and L. sibirica. Needle samples were fixed in the Gammalund’s mixture. The study of the mesophyll was carried out on transverse, paradermal and radial sections of the middle part of the needles using a light microscope. To clarify the shape of chlorenchyma cells, macerated preparations were used. It is shown that the needle mesophyll in Larix species mainly consists of large cells of complex shape, which touch their convex parts or ends to form a well-developed system of intercellular spaces, which may comtribute to intense gas exchange. Different variants of flat folded, flat cellular and more complicated folded-cellular assimilative cells are described. The flat folded cells are characterized by a variety of lobed configurations on transverse sections and elongated oval projections on radial sections. The flat cellular cells are found on needle longitudinal sections of and consist of cellular links facing both perpendicular (cellular cells of the first group) and parallel (cellular cells of the second group) to the leaf surface. The folded-cellular cells combine transverse folded contours and longitudinal cellular outlines. In the needle mesophyll of the studied Larix species, weak differentiation into palisade and spongy parenchyma is observed; the cells of the middle part (median cells) are additionally distinguished between them. The palisade tissue is formed mainly by cellular cells of the first group, the spongy tissue by cellular cells of the second group. The median cells are located on both sides of the vascular bundle along a large needle radius; they can be either flat and slightly folded, or folded-cellular. The studied Larix species are similar in th esize of assimilative cells and the structure of the needle mesophyll; the main differences between them are related to the features of cell dissection both in transverse and longitudinal directions.
MORPHOLOGY AND TAXONOMY OF AULACOSEIRA ALPIGENA (BACILLARIOPHYTA) AND ITS DISTRIBUTION IN RUSSIA
Authors: Genkal S. I.
Published: April 2024

The study of materials from Western and Eastern Siberia and the Far East has revealed a significant variability of an important diagnostic feature (the shape of spines) in Aulacoseira alpigena and a wider range of the species. This study and published data make it possible to emend the diagnosis of A. alpigena and reduce it to the synonyms of a morphologically similar species A. helvetica.