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Relevance. The ovary is strongly radiosensitive organ. Exposure to ionizing radiation can lead to decreased reproductive function, including infertility. One of the promising regenerative substrates is platelet-rich plasma, which contains a large number of biologically active substances. It is necessary to conduct research in this direction in order to determine the dose-dependent effects of electron irradiation on the cell cycle of oocytes and granulosa cells and to assess the risks of developing radiation-induced ovarian failure. It is important to develop methods for the prevention of acute post-radiation complications, which may include platelet-rich plasma injections. Aim: immunohistochemical analysis of ovarian structures’ cell cycle after administration of platelet-rich plasma in a model of radiation-induced ovarian failure. Materials and methods. We divided the animals (Wistar rats; n=40) into four groups: I — control (n=10); II (n=10) — electron irradiation; III (n=10) — administration of platelet-rich plasma before electron irradiation; IV (n=10) — administration of platelet-rich plasma. A morphological assessment and immunohistochemical (Ki-67, caspase 3) examination of the ovaries were performed. Results and Discussion. Number of Ki-67-positive granulosa cells were sharply decreased in group II, but in theca cells the level of expression of this marker exceeded control values. Besides, the number of caspase-3-stained cells increased sharply, mainly due to granulosa cells. The immunohistochemical patterns described were less pronounced in the pre-radiation platelet-rich plasma group. Conclusion. Components of platelet-rich plasma have radioprotective properties, maintaining the cell cycle of follicular cells and reducing the depth and range of radiation damage to the ovary after 20 Gy electron exposure, confirmed by the Ki‑67 and caspase 3 expression levels.

This study investigates the kinetic properties of both symmetrical and asymmetrical multilayer and nano-sized semiconductor structures. We develop a theoretical framework using various models and mathematical methods to solve the Schrödinger matrix equation for a system of electrons, taking into account the Bastard condition, which considers the difference in the effective masses of current carriers in adjacent layers. We analyze tunnel-coupled electronic states in quantum wells separated by a narrow tunnel-transparent potential barrier. Our findings provide insights into the electronic properties of semiconductor structures, which are crucial for applications in micro- or nanoelectronics and other areas of solid-state physics.

Purpose: The subject of research is the spatio-temporal charged particles in the Earth’s magnetosphere outside the South Atlantic magnetic Anomaly during the 11-year cycle of solar activity minimum. The work aims at searching for and clarifying the sustained and unstable new spatial zones of enhanced subrelativistic electron fluxes at the altitudes of the low Earth orbit satellites. Design/methodology/approach: Finding and ascertainment of new radiation belts of the Earth were made by using the data analysis from the D1e channel of recording the electrons of energies of ΔEe=180–510 keV and protons of energies of ΔEp=3.5–3.7 MeV of the satellite telescope of electrons and protons (STEP-F) aboard the “CORONAS-Photon” Earth low-orbit satellite. For the analysis, the data array with the 2 s time resolution normalized onto the active area of the position-sensitive silicon matrix detector and onto the solid angle of view of the detector head of the instrument was used. Findings: A sustained structure of three electron radiation belts in the Earth’s magnetosphere was found at the low solar and geomagnetic activity in May 2009. The two belts are known since the beginning of the space age as the Van Allen radiation belts, another additional permanent layer is formed around the drift shell with the McIlwaine parameter of L = 1.65±0.05. On some days in May 2009, the new two inner radiation belts were observed simultaneously, one of those latter being recorded between the investigated sustained belt at L≈1.65 and the Van Allen inner belt at L≈2.52. Increased particle fluxes in this unstable belt have been formed with the drift shell L≈2.06±0.14. Conclusions: The new found inner radiation belts are recorded in a wide range of geographic longitudes λ, both at the ascending and descending nodes of the satellite orbit, from λ1≈150° to λ2≈290°. Separately in the Northern or in the Southern hemispheres, outside the outer edge of the outer radiation belt, at L≥7–8, there are cases of enhanced particle fl ux density in wide range of L-shells. These shells correspond to the high-latitude region of quasi-trapped energetic charged particles. Increased particle fluxes have been recorded up to the bow shock wave border of the Earth’s magnetosphere (L≈10-12).

Copyright of German International Journal of Modern Science / Deutsche Internationale Zeitschrift für Zeitgenössische Wissenschaft is the property of Artmedia24 and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pollen morphology of the species Iris reticulata M. Bieb. (Iris L., subgenus Hermodactyloides Spach) of the family Iridaceae of the flora of Armenia was studied using light (LM) and scanning electron (SEM) microscopes. [ABSTRACT FROM AUTHOR]

The phenomenon of electron-stimulated adsorption occurs in almost all devices where electron emission is used. Electron-stimulated adsorption can have a significant effect on the state of the adsorbed layer. This review presents typical results obtained in the study of electronically stimulated processes of the oxygen adsorption from a gas phase and the main patterns of changes in the surface structure caused by electron-stimulated adsorption.

The article presents the results of experimental studies of a glow discharge with a hollow cathode in helium and argon gases using an auxiliary discharge as an electron emitter. The authors proposed to make the electrode common for both discharges in the form of a cylindrical metal mesh. The advantage of this design is explained as follows. The connection between the discharges is carried out through holes in the grid with a geometric transparency of 0.2, which makes it possible not only to smoothly control the glow discharge current, but also to enhance the discharge current. Plasma is known to be one of the most efficient electron emitters; however, its use as a cathode in devices with a glow discharge at low gas pressures is complicated by the fact that a grid with small holes is required to separate the electron flow from the plasma, and it is impractical to use such a system in view of low mechanical strength of the grid Since the hollow cathode works effectively at low gas pressures, the release of an electron flux from the plasma of some auxiliary discharge is possible with much larger holes in the grid separating the plasma and the hollow cathode cavity. In this case, the grid can be made such that it can withstand sufficiently high thermal loads and can operate in typical discharge modes with a hollow cathode. The injection of electrons into the cathode cavity of the glow discharge changes the radial distribution of the glow intensity, the width of the cathode dark space, and other parameters of the plasma in the cathode cavity. The influence of electrons penetrating from the auxiliary discharge into the cathode cavity of the main discharge becomes significant when the current of these electrons is comparable to or exceeds the current of electrons leaving the grid cathode surface as a result of γ-processes. In parallel with the measurement of the optical and electrical characteristics of the hollow cathode glow discharge plasma, measurements of the electron concentration were carried out by the microwave sounding method. The entire current of the auxiliary discharge penetrates into the cavity of the main discharge; however, after acceleration in the cathode dark space, the electrons penetrating from the auxiliary discharge ionize gas atoms and noticeably increase the current of the main discharge. Additional ions formed due to the ionization of the gas by the injected electrons knock out new electrons from the cathode surface, which makes it possible to increase the discharge current.

The features of the current-voltage characteristics of LEDs obtained on the basis of GaP-GaAsP solid solutions are considered. The results of studies of the effect of electron irradiation (E = 2 MeV, F = 3 · 1014 ÷ 2.6 · 1016 cm-2 ) on the main electrophysical parameters of GaAs1-xPx diodes (x = 0.85 – yellow, x = 0.45 – orange) are given. The increase of differential resistance, the series resistance of the base, and barrier potential are revealed. The processes of recovery of the investigated quantities during isochronous annealing are analyzed, the mechanisms of degradation-recovery phenomena are discussed. [ABSTRACT FROM AUTHOR]

An approximate method for calculating the proβaβility of single-photon annihilation of a positron with an atomic electron at the β+-decay averaged over all electrons of the daughter atom is proposed. The electrons are descriβed in the framework of the Thomas -Fermi statistical model. This approximation makes it easy the calculation of the average proβaβilities of various processes involving all the electrons of the atom. The total proβaβility of single-photon annihilation is calculated using an approximate analytical expression for the atomic electrons’ density. A good agreement βetween the proβaβilities calculated in the proposed approach and the estimates oβtained in the framework of quantum mechanics was oβtained. [ABSTRACT FROM AUTHOR]

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite the potential of [1,2,4]triazino[4,3-c]quinazoline derivatives as promising bioactive compounds, their electronic spectra has not been studied. Present manuscript is aimed to the estimation of relationships of molecules structure with the nature of their UV-spectra and identifying spectral patterns of pharmacophore that determines the pharmacological activity of the substance. Mentioned information undoubtedly contributes to the development of the theory of the purposeful synthesis of organic compounds. Methods and results. UV-spectra of sodium (3-oxo-3,4-dihydro-2H-[1,2,4]triazino[4,3-c]quinazolin-4-yl)acetate in different polarity solvents have been studied. It allowed to identify types of electron transitions, which were responsible of emergence of the observed absorption bands. Conclusions. It was found that the UV-spectra of the studied compounds in solvents with different polarity were characterized by three absorption bands in the range 190–227 nm, 260–284 nm and 328–348 nm. According to Braude classification the first absorption band should be classified as 1La, the second – as 1Lb, and the third band is due to p-π- conjugation in the molecule of the whole molecule structure.

Results of reverse electrophysical characteristics study of red and green LEDs, initial and irradiated with 2 MeV electrons were given. It was found that reverse current was predominantly caused by carriers tunneling at Urev ≤ 9 V, and by the avalanche multiplication at Urev ≥ 13 V, in the range U = 9 ÷ 13 V both mechanisms are available. Current increase at high voltage areas (Urev > 19 V) is limited by the base resistance of diode. In the case of significant reverse currents (I > 1 mA) irradiation of diodes leads to the shift of reverse current-voltage characteristics into the high voltages direction.

In this paper, using Auger electron spectroscopy and electron energy-loss spectroscopy the kinetics of oxygen adsorption on thallium was studied in two cases: under continuous electron irradiation (100-1000 eV) and without depending on the exposure time in oxygen at a partial pressure oxygen 10^-6 Torr at room temperature.

Nonradiochemical method of measurement of 90Sr and137Cs activity in environmental samples is proposed. This method is based on spectrometrical investigation of electrons accompanied the decay of the 90Sr and137Cs. Accounting for the contribution to the total activity of the samples from the zones with the density of the contamination 1 - 5 Кu/km2 the 40K electrons allowed to improve the accuracy of the measurements for the samples of small rodents up to 15 - 20 % (the ratio of A (137Cs)/A (90Sr) was from 2 to 100), for samples of soil up to 10 - 15 % (the change of activity in these samples was ten thousand times). The results of the spectrometric measurements were confirmed by the traditional radiochemical research.

Model of modification of basic levels of the known radiation defects in silicon and a germanium is offered. Energy of Hubbard is independent of number of electrons on radiation defect, and its size depends on base-line admixtures near-by vacancy defect. If near-by vacancy defect of the interstitial atom of oxygen is located, then energy of the negatively-charged acceptor defect is reducing on 0.06 eV, and energy of donor rises on the same size. The interstitial atom of silicon and of germanium changes the levels of defect on 0.03 eV. The atom of carbon in the interstitial site changes energy of vacancy defect on 0.035 eV, but in opposite direction. Modification of vacancy defects does not change energy of neutral defect level in the band gap in silicon and germanium. [ABSTRACT FROM AUTHOR]

Introduction: Convalescent COVID-19 patients have various signs of central nervous system damage, including those directly associated with SARS-CoV-2. Hence, studies of SARS-COV-2 related morphological changes in neocortex are particularly relevant for understanding the mechanisms of their formation and development of approaches to preclinical evaluation of the effectiveness of antiviral drugs. The purpose of the research is a longitudinal study of the ultrastructural alterations in Syrian hamsters neocortex after experimental SARS-CoV-2 infection., Materials and Methods: Male Syrian hamsters weighing 80100 g, aged 4 to 6 weeks, were infected with 26 l SARS-CoV-2 intranasally with 4104 TCD50/ml of viral particles. The animals were euthanized on days 3, 7 or 28 post-infection, the brain was extracted with the cortex excision. The material analysis was performed using transmission electron microscopy., Results and Discussion: On day 3 post-infection, the number of moderately hyperchromic neurons in neocortex increased, while by the day 7 the number of apoptotic cells significantly increased. Simultaneously, an increased signs of neuronophagy and representation of atypical glia were observed. Increased number of altered oligodendrocytes was observed on day 28 post-infection. Viral invasion was accompanied by changes in neocortical cells since day 3 post-infection, such as transformation of their nucleus, the rough endoplasmic reticulum and the Golgi vesicles as well as microvascular spasm with perivascular edema., Conclusion: As a result of electron microscopic study, the ultrastructural alterations in neocortex were described in an experimental model of SARS-CoV-2 infection. The findings can be used to identify the mechanisms of infection pathogenesis and to search for the new directions in development of medicines.

The yields near-zero energy electrons(e0-electrons) and fast electrons (erelectrons) in the bombardment of targets of aluminum and titanium by α-particles of 238Pu in die low-energy α-particles region (range 0.9 - 5.5 MeV) were measured. An increase in output e0- and ey-electrons is observed when the energy of α-particles is reduced. Outputs e0-electrons for α-particles of different energies Eα in this area is well described by the dependence (Eα) ∼ Eα-1/2 ∼ v-1 as previously has been observed in our studies of the decay of 226Ra (range 4.7 - 7.6 MeV) and the bombardment of the target by α-particles at cyclotron U-120 (range 9.7 - 24 3 MeV). [ABSTRACT FROM AUTHOR]

Calculation technique of the equilibrium distance between two interacting atoms, which is one of three parameters of the Morse potential, is proposed in the work. Dependence of the lattice energy (energy of one atom in it) on the parameter value is obtained, and the function extreme is determined. Energy of an atom is calculated as a sum of potential energies of atom interaction with its neighbors (more than 15 coordination spheres are taken into account, the energy calculation error is less than 0,01%). Calculation is carried out for 12 chemical elements. [ABSTRACT FROM AUTHOR]

Nonradiochemical method of measurement of 90Sr and137Cs activity in environmental samples is proposed. This method is based on spectrometrical investigation of electrons accompanied the decay of the 90Sr and 137Cs. Accounting for the contribution to the total activity of the samples from the zones with the density of the contamination 1 - 5 Ku/km2 the 40K electrons allowed to improve the accuracy of the measurements for the samples of small rodents up to 15 - 20 % (the ratio of A (137Cs)/A (90Sr) was from 2 to 100), for samples of soil up to 10 - 15 % (the change of activity in these samples was ten thousand times). The results of the spectrometric measurements were confirmed by the traditional radiochemical research [ABSTRACT FROM AUTHOR]

Using the effective mass and rectangular potentials approximations the theory of dynamic conductivity of electrons is developed for the plane multi-layer resonance tunnel structure within the model of the open nanosystem. The oscillator forces of quantum transitions are studied within the model of the closed nanosystem. For the experimentally produced quantum cascade detector it is proved that just the theory of dynamic conductivity in the model of open cascade most adequately describes the process of absorption of a high-frequency electromagnetic field while the electrons are being transported through the resonance tunnel structure [ABSTRACT FROM AUTHOR]

The results of studying a dissociative ionization of the methane molecule by the electron impact are presented. The experiment was performed using the monopole mass spectrometer-based apparatus. The most likely pathways of the methane molecule fragmentation under a slow electron impact were analyzed. The effciencies of creation of the molecular and ion fragments of the methane molecule were measured within the electron energy range of 6-90 eV. The appearance energies for relevant ions were determined from the experimental energy dependencies of ionization cross-sections using the least-squares approximation by means of the Levenberg-Marquardt algorithm [ABSTRACT FROM AUTHOR]

One-electron states of the quantum dot modelled by a spherically symmetric oscillator-Coulomb potential are studied. The proposed model generalizes the known parabolic model of the quantum dot. The transcendental equation for the electron spectrum and expressions for the wave functions are obtained. The dependence of the oneelectron spectrum on the quantum dot effective size and other parameters of the model potential are found. These parameters can serve as control parameters to optimize the energy structure of a spherical quantum dot in order to obtain real structures with predetermined physical and chemical properties. The conditions of applicability of the model to describe electronic properties of metallic and semiconducting quantum dots are studied. The obtained results are compared with other models of the quantum dot - spherical, rectangular and parabolic. [ABSTRACT FROM AUTHOR]

In fluorite crystals doped with alkali metals a new electronic FD-center colouring has been discovered. This center is an F-center located in the vicinity of the impurity vacancy dipole. The FD-center occurs in the repeated exposure of optically discoloured crystals in M+A -lines of absorption and is formed due to the localization of zone electrons in the band of two vacancy complexes: e- + V⋅a Me'V⋅a → V0a Me'V⋅a where e- is a band electron; V⋅a is an anion vacancy; Me' is an alkali metal ion; V0a is an F-center; V0a Me'V⋅a is an FD-center. FD-center are thermally stable at the temperatures of T < Tr (Tr is the temperature rotation IVD). At T > Tr FD-centers are transformed into M+A-centers: … [ABSTRACT FROM AUTHOR]

The study of autoionization of atomic shell at β-decay 152Eu was performed. Relation of energy of autoionization electrons and their correlation on outgoing direction with a β-particle from boundary energy of β-particle was investigated. Measurements are executed on the installation of coincidences of γ-quanta and β-particle with law energy electrons at registration of autionization electrons created by eo-electrons of the secondary electron emission (γβeo-coincidences). Due to obtained data the expansion of a energy spectrum of autoionization electrons is proportional to boundary energy of β-spectrum. Correlation direction of emitting of autoionization electron on outgoing directions of β-particle does not depend on energy β-particle. [ABSTRACT FROM AUTHOR]

High-precision measurements of the energies of reference γ-transitions from the decay of 175Hf have been performed with the γ-spectrometer. Using this data, the energies of levels and corresponding deexciting γ-rays in 175Lu were determined with the precision up to a few electron-volts. To a great extent they are in a good agreement with other experimental data but is more precise. [ABSTRACT FROM AUTHOR]

An analytical study of the asymptotic properties of the quasimolecular system (ApB)(Za+Zb-1)+ consisting of the polar molecule (Ap)(Za-1)+ and the highly charged atomic ion BZb+ was carried out. The influence of point dipole of the polar molecule core on the asymptotic of the one-electron wave functions of the (ApB)(Za+Zb-1)+ system for large distances between interacting particles was taken into account. The new analytical expression for the leading term of the asymptotic of one-electron exchange interaction in the quasimolecule (ApB)(Za+Zb-1)+ was obtained in the framework of the semiclassical approach. [ABSTRACT FROM AUTHOR]

The theory for the mechanical moment transfer to the asymmetrical nanoparticle from the ultrashort laser pulse is developed. It is established that the optical conductivity becomes a tensor for the particle sizes less than the electron free pass in it. The diagonal elements of this conductivity define the half-widths of the plasmon resonances. The expressions for the components of the polarization tensor of a spheroidal metallic nanoparticle is obtained. [ABSTRACT FROM AUTHOR]

The problem of the interaction of two quasimolecular electrons located at an arbitrary distance from each other near different atoms (nuclei) is solved. The effects of the third order in the quantum electrodynamics which include the exchange of the virtual photon between the electrons and radiation (absorption) of the real photon are considered. The general expression for the matrix elements of the operator of the effective interaction energy of two quasimolecular electrons with the external radiation field is obtained. It allows to calculate the probabilities of inelastic processes with the rearrangement in slow collisions of multicharged ions with relativistic atoms. The successive implementation of the procedure of symmetrization of the retardation factor with respect to both electrons is shown to lead to a rise of the additional terms in the relativistic operator of the interaction of two quasimolecular electrons compared with both the standard Breit operator and the generalized Breit operator from papers [O. N. Gadomsky, V. R. Nagibarov, N. R. Solovarov, Zh. Eksp. Teor. Fiz. 63 813 (1972); 70 435 (1976); O. N. Gadomsky, K. K. Altunin, Zh. Eksp. Teor. Fiz. 144 1555 (1998); O. N. Gadomsky, Usp. Fiz. Nauk 170, 1554 (2000)]. [ABSTRACT FROM AUTHOR]

The aluminium laser plasma was investigated by the method of emission spectroscopy. The temperature of electrons is changed within the limits of 24360-5800 K, and concentration of electrons of 3.4×1017-4.7×1015 cm-3, to 160 ns time in the distance of 1 mm from the target. [ABSTRACT FROM AUTHOR]

Objectives: the study of the nature and severity of the reorganization of the structural elements of the bladder wall on experimental models of IC / BPS at the optical and ultrastructural levels., Materials and Methods: The experimental model of IC / SBMP was created on 22 white New Zealand female rabbits weighing 1500-2000 g. The animals were divided into 2 groups: group 1 - 15 rabbits, which were introduced into the bladder wall urine taken from the animals bladder; Group 2 (control) - 7 animals that were injected into the bladder wall with a 0.9% NaCl solution. The biomaterial was examined by electron microscopy. The structural elements of the lamina propria of the bladder mucosa were evaluated., Results: In the bladder mucosa of the experimental model, perivascular infiltration by inflammatory cells, pronounced edema of the lamina propria of the bladder mucosa, and the presence of numerous plasma cells having close contacts with macrophages, fibroblasts, and lymphocytes were revealed. In the nucleus of lymphocytes of a peripherally located supercondensed heterochromatin showed their apoptotic state. Edematous fluid was determined, penetrating mainly through the fenestra, located in the peripheral parts of the endothelial cells of capillaries and postcapillary venules., Conclusion: The study of the structural elements of the lamina propria of the bladder mucosa in the experiment by the method of electron microscopy made it possible to identify changes caused by the inflammatory process, both of an acute and productive nature. The results obtained showed that toxic damage to the lamina propria of the bladder mucosa causes apoptosis of fibroblasts of the lamina propria, leads to loosening of collagen fibers and, ultimately, to a decrease in the protective factors of the mucous membrane.