Currently, nitric oxide (NO) is considered a signaling molecule that acts as a universal regulator of many physiological processes in the body. The purpose of this research was to study the effects of exogenous NO on microcirculatory vessels and their blood flow under experimental conditions for the pathogenetic justification of NO therapy and correction of microcirculatory disorders. Methods. Effects of exogenic NO on microvessels of cranial pia mater were studied in white Wistar rats. Another set of experiments was carried out in hamsters to correct microcirculatory disorders caused by inflammatory-destructive lesions of the oral mucosa of the cheek pouch with NO therapy. Results. The effectiveness of the complex treatment of inflammatory-destructive diseases of the oral mucosa has increased with the use of NO. Conclusion. It has been established that the key factor in the positive effect of exogenous NO in therapeutic doses on blood microcirculation is the activation of vasomotor activity of microvessels.

A histophysiological investigation of the experimental animals skin was performed on day 3 after exposure to holmium-doped fiber laser continuous-wave radiation at different power intensities. Using histologic and functional research methods, changes characteristic of the exudative stage of aseptic inflammation were revealed, the severity of which depended on the radiation dose.

The paper presents the results of a comprehensive assessment of central hemodynamic and microcirculation indices in the skin of upper and lower limbs in 6–7-year-old children. 14 girls and 7 boys were examined using laser Doppler flowmetry methods (the LASMA-PF device, allowing simultaneous recording by four sensors) and the analysis of heart rate variability ("Varicard"). The parameters characterizing microcirculation in the limbs were determined and the signs of the appearing functional asymmetry of the upper limbs, as well as the differences in the mechanisms of modulation of cutaneous blood flow in boys and girls were revealed. The estimation of heart rate variability reveals the signs of girls' inclination to sympathotony and boys' inclination to vagotony at the given age. It was marked that central regulation mechanisms have the greater contribution to cardiac rhythm formation in girls. The data obtained testify to the fact that age-related changes at different levels of the cardiovascular system and regulation mechanisms occur somewhat earlier in girls than in boys.

The aim of the study was to study of age-related changes in cytoarchitectonics in functionally different areas of the posterior associative cortex in the temporal and occipital lobes of the cerebral hemispheres in children during the first year of life. Material and methods. The study material included left hemispheres of male children (39 observations) aged from birth to 12 months who died in accidents without brain damage. Using computer morphometry, the thickness of the cortex, the thickness of the external pyramidal layer and the area of the profile field of pyramidal neurons were measured on Nissle stained frontal histological sections of the cortex taken in the temporo-parietaloccipital subfield (subfields 37a, 37a, 37d) and field 19 of the occipital region, which are jointly part of the posterior associative cortex. Quantitative data were analyzed at monthly intervals. Results. The thickness of the posterior associative cortex in infants on the lateral surface of the temporal and occipital lobes increased by 3, 6, and 9 months; on the inferior medial and medial surfaces of the temporal lobe, by 5 and 12 months. Significant increases in the cross section of layer III occurred simultaneously: in subfield 37as by 2 and 6 months, in subfield 37a by 3 and 8 months, in subfield 37d by 2 and 5 months, and in field 19 by 3 and 9 months. All of the studied neocortex zones were characterized by two-stage cortical growth in thickness, as well as a faster rate of increase in the thickness of layer III in relation to the total cortical cross section, relative stability in the size of pyramidal neurons in sublayer III3 from birth to 3 months and their intense increase from 3 to 8-9 months. Conclusion. Microstructural changes in different fields of the posterior associative cortex have significant differences, which are reflected in the age-related dynamics of the thickness of the cortex and associative layer III, as well as the size of the pyramidal neurons. The most significant structural and functional changes in these parameters are noted from 3 to 5 months and from 8 to 9 months, as well as by the end of the first year of life.

Introduction.The state of the blood flow within the capillaries and close blood vessels is highly important in practice for the revealing of pathogenetic mechanisms of both systemic and local circulatory disorders.Aimof the study was to define the parameters of microcirculation and the level of blood flow fluctuations (flux) in the distal segments of upper and lower limbs (in fingers of hands and toes of feet) in children of 6–7 years old; and to describe the possible differences in the mechanisms of blood flow modulation in boys and girls.Materials and methods.Skin microcirculation was assessed in middle fingers of hands and great toes of feet in children of 6-7 years old (14 girls and 7 boys in prone position) by means of laser doppler flowmetry.Results.The ranges for parameters of microcirculation (PM) for distal segments of upper and lower limbs in children of mentioned age group were defined, also it was shown that the PM are significantly lower in the lower limbs comparing to those of the upper limbs (both in groups of girls and boys). Asymmetry of PM in the feet was not found; the features of right hand-left hand asymmetry for PM in girls and boys are described. The analysis of modulation of blood flow fluctuations (fluxmotions) of different frequencies showed the profound role of vasomotor (myogenic) rhythm for regulation of microcirculation.Conclusion.Increased neurogenic influences on the modulation of fluxmotions in girls of 6-7 years old may be an evidence of the ongoing development of the mechanisms of blood flow regulation, particularly the association with the growth rate of girls is possible.

The authors present a review of publications in the scientific and medical literature on modern concepts of mechanisms of low-level laser biostimulating effects at the human body, at microvasculature chains and lymphoid organs. The main aspect of microcirculation photoactivation is the process of microcirculation reconstruction which leads to prolonged improvement in tissue trophism. There are three processes in the basement of biostimulating effect of low-level laser light in the red and near infrared spectral regions at microcirculation: hemomicrocirculation enhancement, activation of capillary neovascularization, lymphocorrection effects at the structure and functional activity of lymphoid organs.

The authors present a review of publications in the scientific and medical literature on modern concepts of mechanisms of low-level laser biostimulating effects at the human body, at microvasculature chains and lymphoid organs. The main aspect of microcirculation photoactivation is the process of microcirculation reconstruction which leads to prolonged improvement in tissue trophism. There are three processes in the basement of biostimulating effect of low-level laser light in the red and near infrared spectral regions at microcirculation: hemomicrocirculation enhancement, activation of capillary neovascularization, lymphocorrection effects at the structure and functional activity of lymphoid organs.

AIM:the aim of our study was to identify of structural transformations in the thymus and lymph nodes at the early stages of the development of an experimental prostate cancer.MATERIALS AND METHODS:Experiments were performed on 60 adult male CBA mice weighing 28-30 g. An experimental model of a prostate cancer was created by inoculating a diluted cell strain of Ehrlich Ascites Carcinoma cells into the prostatic parenchyma through midline laparotomy under ether anesthesia. The animals were divided into three groups of 20 each: 1) control (intact animals) 2) animals on the 5th day of experimental prostate tumor growth and 3) animals on the 18th day of experimental prostate tumor growth. The pathological examination of the prostate, thymus, and pelvic lymph nodes was performed. The selection of structural components and cellular elements in the thymus and lymph nodes was carried out according to the International histological nomenclature.RESULTS:According to the results, there was an increase in the percentage of connective tissue elements and glandular tissue increased in the thymus and the number of immunoblasts increased on the 5th day of the experiment. However, disorganization of the thymus structure was detected on the 18th day as well as an increase in the cortical substance, the number of epithelial reticular cells and decrease in the number of immunoblasts. On the 5th day, paracortical hyperplasia, sinus histiocytosis and activation of the blast transformation were detected in lymphatic nodes. On the 18th day, metastases, follicular reaction and activation of the transport function were determined.CONCLUSION:Our data suggest that the accidental thymus involution and impairment of transport and immune functions of pelvic lymph nodes in experimental prostate cancer. The severity of disturbances depends on the stage of prostate carcinogenesis.

Two-dimensional (2D) electron systems with a combined Rashba and Dresselhaus spin-orbit interaction (SOI) having a complicated energy spectrum with a conical point and four critical points are promising candidates to observe electron topological transitions. In the present paper we have investigated the evolution of the electron spectrum and isoenergetic contours under the influence of a parallel magnetic field. General formulas for the energies of critical points for arbitrary values of SOI constants and magnetic field are found. The existence of critical magnetic fields at which a number of critical points is changed has been predicted. The magnetic field driving topological Lifshitz transitions in the geometry of isoenergetic contours has been studied. Van Hove's singularities in the electron density of states are calculated. The obtained results can be used for theoretical investigations of the different electron characteristics of such 2D systems.

Spin orbit interaction (SOI) having a complicated energy spectrum with a conical point and four critical points are promising candidates to observe electron topological transitions. In the present paper we have investigated the evolution of the electron spectrum and isoenergetic contours under the influence of parallel magnetic field. General formulas for energies of critical points for arbitrary values of SOI constants and magnetic field are found. The existence of critical magnetic fields at which a number of critical points is changed has been predicted. The magnetic field driving topological Lifshitz transitions in the geometry of isoenergetic contours have been studied. Van Hove's singularities in the electron density of states are calculated. The obtained results can be used for theoretical investigations of different electron characteristics of such 2D systems.

New exact and asymptotical results for the one particle Green's function of 2D electrons with combined Rashba-Dresselhaus spin-orbit interaction in the presence of in-plane uniform magnetic field are presented. A special case that allows an exact analytical solution is also highlighted. To demonstrate the advantages of our approach we apply the obtained Green's function to calculation of electron density and magnetization. (C) 2018 Elsevier B.V. All rights reserved.

Effects associated with the interference of electron waves around a magnetic point defect in two-dimensional electron gas with combined Rashba-Dresselhaus spin-orbit interaction in the presence of a parallel magnetic field are theoretically investigated. The effect of a magnetic field on the anisotropic spatial distribution of the local density of states and the local density of magnetization is analyzed. The existence of oscillations of the density of magnetization with scattering by a non-magnetic defect and the contribution of magnetic scattering (accompanied by spin-flip) in the local density of electron states are predicted.

We present a theoretical study of the spatial distribution of the local density of states (LDOS) and the local magnetization density (LMD) in the vicinity of a magnetic point-defect in a degenerate two-dimensional electron gas with a mixed Rashba-Dresselhaus spin-orbit coupling interaction (SOI). The dependence of the Friedel oscillations, which arise under these conditions, on the ratio of the SOI constants is investigated. We obtain asymptotic expressions for the oscillatory parts of the LDOS and the LMD, that are accurate for large distances from the defect. It is shown, that the Friedel oscillations are significantly anisotropic and contain several harmonics for certain ratios of the SOI constants. Period of the oscillations for directions along the symmetry axes of the Fermi contours are determined. Finally, we introduce a method for determining the values of the two SOI constants by measuring the period of the Friedel oscillations of the LDOS and the LMD for different harmonics.

The active methods of damping vibrations of thin-walled elements are used widely in technics. Efficiency of the damping depend on working of active elements - piezoelectric sensors and actuators. On the efficiency of sensors and actuators the geometric parameters and material anisotropy influence. To investigate this influence the refine models have to be used. In this paper the influence of shear strain on efficience of piezoelectric sensors and actuators under active damping of resonance vibrations of transversally-isotropic cylindrical panel and rectangular hinged plate is investigated. To sumilate the vibrations of thinwalled elements with the sensors and actuators refined Timoshenko' theories are used. By Furrie method the analutical solution of the problems about resonant vibrations of thous elements are obtained. The formulas are given for the potential difference, wich suppled to actuators to balanced mechanical loads. Analogical formulas are given for sensor' indications. The formular for damping coefficient under the using of sensors and actuators for active damping of resonant vibrations of the plate and panel are given. These simple formulas allow to evaluate the influence of shear strains on efficiency of piezoelectric sensors and actuators and efficiency of active damping of resonance vibrations of the elements.

С помощью лазерной допплеровской флоуметрии (ЛДФ) изучали параметры микроциркуляции крови в коже различных топографо-анатомических областей тела у здоровых лиц в возрасте 18-24 лет. Особенности строения кожи и ее микроциркуляторного русла в этих участках тела исследованы гистологическими методами и с помощью капилляроскопии. Определены нормативные показатели состояния микроциркуляции крови в коже головы, туловища и основных сегментов верхней и нижней конечностей. Величина параметров ЛДФ в коже разных областей тела зависит от плотности функционирующих капилляров, толщины эпидермиса и глубины залегания микрососудов.

The conductivity tensor of a layered conductor with the Dirac-type energy spectrum of charge carriers placed in a quantizing magnetic field under the condition of normal skin-effect is investigated using the method of quantum kinetic equation. It is shown that under the cyclotron resonance conditions there appear high-temperature quantum oscillations of conductivity, which are weakly sensitive to thermal broadening of the Fermi level. We present the expressions for the classical and high-temperature contributions to the conductivity tensor which determine the conductivity in the range of not too low temperatures where the Shubnikov–de Haas oscillations are vanishing.

Using laser doppler flowmetry (LDF) the parameters of skin microcirculation of different topographo-anatomic regions of the body at healthy persons age of 18—24 years were studied. Features of the skin structure and microvessels in these areas of the body are investigated by histological methods and capillaroscopy. Normative parameters of microcirculation in the skin of head, body and main segments of hand and leg are determined.

В стратотипических разрезах рифея Башкирского мегантиклинория (Южный Урал) машакская свита является базальной для среднерифейской эратемы. На всей площади распространения она представлена чередованием вулканогенных, вулканогенно-осадочных и осадочных пород. Свита расчленена на нижнюю, среднюю и верхнюю подсвиты. Вулканиты, из которых выделен циркон (4 пробы, риодациты и риолиты с хр. Машак, р. Березяк и хр. Большой Шатак), приурочены к нижней подсвите. Использована методология SHRIMP-II, особое внимание уделялось минералогическим особенностям кристаллов циркона, их облику, степени сохранности, включениям. По минералого-геохимическим параметрам цирконы всех проб сопоставимы, что уже предполагает геохимическую общность вулканитов. Тем не менее у кристаллов проявляются и индивидуальные особенности, отражающие некоторые параметры и самих вулканитов, связанные с различными условиями их образования. Интегральный U-Pb возраст цирконов (SHRIMP-II, ВСЕГЕИ, Санкт-Петербург) всех четырех проб составляет 1383 ± 3 млн. лет. С учетом возраста магматитов Бердяушского массива (до 1410 млн. лет) он позволяет оценить возрастной рубеж нижнего–среднего рифея в 1400 млн. лет, что совпадает с границей экстазия и калиммия в Международной стратиграфической шкале.