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On the example of the hot Jupiter HD 189733b, in whose magnetosphere the conditions for the ’operation’ of an electron–cyclotron maser are not fulfilled, an analysis of the plasma mechanism of radio emission generation is carried out. The purpose of the analysis is to highlight the range of parameters at which the realization of a plasma maser is possible, as well as to determine the frequency range of generated radio emission. The conditions under which the plasma maser is efficient enough to generate radiation with the intensity accessible for observation by the existing radio telescopes are also defined.

The importance of trace elements in the nutrition of young farm animals is extremely high, since they participate in the regulation of basic physiological processes, and also serve as activators of enzymes of structural elements. In order to achieve good growth and development indicators of young cattle, it is necessary to optimize their mineral nutrition. In this regard, it is necessary to study the effect of certain mineral substances (Co, Se, I, Mn, Zn) in early postnatal ontogenesis on the clinical and hematological parameters of the body of calves.The research was carried out in 2021 on black-and-white cattle on the basis of the Department of Veterinary Medicine of Astrakhan State University. Determination of the levels of trace elements in the ecosystem was carried out in the Astrakhan region. In addition, 6 heads of black-and-white cattle were selected. Samples for the study were taken from animals aged from 1 to 6 months. Determination of hematological parameters of animals was carried out on the IDEXX Laser Cyte analyzer (USA), biochemical parameters – on the IDEXX Catalist analyzer (USA).The conducted studies have shown a low level of some trace elements in the ecosystem of the Astrakhan region. The greatest amount in soil and plants contains manganese and zinc, the least – selenium. However, the lack of certain minerals in early postnatal ontogenesis does not affect the hematological parameters of the calves' body. All the studied parameters were within the limits of physiological norms, which may be associated with the long-term pathogenesis of microelementoses in animals.

The medical community, researchers and healthcare organizers are constantly challenged by comparing key indexes reflecting the effectiveness of cardiovascular care, primarily for the dynamic assessment and implementation of the world's best practices to reduce cardiovascular mortality. The analysis of health care for patients with cardiovascular diseases (CVD) is a complex, multicomponent process, the structure and key tools of which differ from country to country. Using different data sources, methodological and analytical approaches creates certain limitations and barriers to the assessment. In order to update the ideas about the modern coordinate system and tools for assessing cardiovascular care, the authors presented practices for analyzing major indexes in Russia, European countries, and the United States. The review presents sources of statistical data, principles for assessing risk factors, cardiovascular morbidity and mortality, and specific features of monitoring the availability and quality of cardiovascular care.

Objectives. The purpose of this analytical review is to evaluate the market for osteoplastic materials and surgical implants, as well as study the features of new-generation materials and the results of clinical applications.Methods. This review summarizes the volumes of research articles presented in the electronic database PubMed and eLIBRARY. A total of 129 scientific articles related to biological systems, calcium phosphate, polymer, and biocomposite matrices as carriers of pharmaceutical substances, primary recombinant protein osteoinductors, antibiotics, and biologically active chemical reagents were analyzed and summarized. The search depth was 10 years.Results. Demineralized bone matrix constitutes 26% of all types of osteoplastic matrices used globally in surgical osteology, which includes neurosurgery, traumatology and orthopedics, dentistry, and maxillofacial and pediatric surgery. Among the matrices, polymer and biocomposite matrices are outstanding. Special attention is paid to the possibility of immobilizing osteogenic factors and target pharmaceutical substances on the scaffold material to achieve controlled and prolonged release at the site of surgical implantation. Polymeric and biocomposite materials can retard the release of pharmaceutical substances at the implantation site, promoting a decrease in the toxicity and an improvement in the therapeutic effect. The use of composite scaffolds of different compositions in vivo results in high osteogenesis, promotes the initialization of biomineralization, and enables the tuning of the degradation rate of the material.Conclusions. Osteoplastic materials of various compositions in combination with drugs showed accelerated regeneration and mineralization of bone tissue in vivo, excluding systemic side reactions. Furthermore, although some materials have already been registered as commercial drugs, a plethora of unresolved problems remain. Due to the limited clinical studies of materials for use on humans, there is still an insufficient understanding of the toxicity of materials, time of their resorption, speed of drug delivery, and the possible long-term adverse effects of using implants of different compositions.

We have developed a method for the preparation of macroporous carbonate hydroxyapatite-based matrices with the use of the technology of self-setting cements for surgical osteology. Macroporosity of osteoconductive calcium phosphate matrices was produced by adding paraffin granules to a dry cement mixture, followed by organic solvent extraction of the granules from matrices hydrated in an aqueous solution. In vivo tests of the resultant materials demonstrated high biocompatibility with pronounced angiogenesis, which was achieved via additional treatment with supercritical carbon dioxide.

A method for producing a new generation of high-purity xenogenic biomatrixes suitable for implantation in a living organism is proposed. Special biocompatibility can be achieved by additional treatment with supercritical carbon dioxide and the introduction of dosed amounts of polylactides with molecular weight of 20 and 40 kDa in the porous space of the matrix. In vivo testing of the obtained materials showed their high biocompatibility with varying degrees of integration with surrounding tissues.

Analysis of the phenomenon of the shrinkage of a coronal magnetic loop during the impulsive phase of a flare makes it possible to determine both the evolution of electric current in the loop and the loop resistance. We show that the flare process is accompanied by a substantial (two orders of magnitude) increase in the loop resistance along with a slight (~20%) decrease in the electric current. As a result, the rate of energy release grows sharply. The Rayleigh–Taylor instability in the chromosphere foot-points of the loop leads to a decrease in the cross section of the current channel and to a sharp increase in the loop resistance, simultaneously triggering a flare. The physics of loop shrinkage is illustrated by the examples of August 24, 2002 and January 20, 2005 flares.

Developing ideas of the paper Zaitsev and Stepanov (2018) with regards to activation of a current-carrying filament with an increase in electric current, in which the Ampere force is opposed by gravity and medium viscosity, we take into account the influence of an external magnetic field. It is shown that, depending on mutual directions of the external magnetic field and electric current in the flux rope, the additional Ampere force can lead to the deceleration or to additional eruption of the flux rope. A phase diagram describing the peculiarities of flux rope dynamics has been constructed. The maximum height and velocity of the flare loop are determined for the event on March 30, 2001.

The main properties of microwave radiation sources over the magnetic field neutral line, which follow from the assumption of a gyrosynchrotron mechanism of radio emission, have been considered. As an example, the strong event of September 3–5, 2017, which was followed by a number of powerful flares, has been analyzed. A possible reason for the continuous electron acceleration of the gyrosynchrotron mechanism is discussed, along with the conditions under which the gyrosynchrotron mechanism of microwave radiation plays no significant role in the origin of sources above the neutral line.

In the work physically reasonable algorithm of numerical modeling of nonlinear oscillatory and self-oscillatory systems are offered. The algorithm is based on discrete in time model of the linear oscillator. Nonlinearity is considered by the introduction to the oscillator of additional communications by the structural analysis of an initial system. For approximation of a temporary derivative in nonlinear communications it is offered to use the scheme of the prediction and correction. In spite of the fact that theoretically the algorithm has the second order of accuracy, within the numerical experiment with Van der Pol oscillator it shows better results, than a standard method of the second order the Heuns method.

A mechanism for acceleration of electrons driven by the oscillations of the electric current in solar magnetic loops is considered. The magnetic loop is presented as an equivalent RLC-circuit with the electric current generated by convective motions in the photosphere. Eigen oscillations of the current in a loop induce the electric field directed along to the loop axis. It is shown that pulsating type III bursts and the sudden reductions that occur in the course of type IV continuum in solar flares provide evidence for acceleration and storage of energetic electrons in the coronal magnetic loops. Energization rate of electrons accelerated by sub-Dreicer electric field are determined. The energy spectra of fast electrons under both intermediate and strong regimes of pitch-angle diffusion are discussed. Two examples of the electron acceleration in the pulsating type III solar bursts are considered. We also discuss the efficiency of suggested mechanism as compared with the electron acceleration during 5-min photospheric oscillations and with the acceleration driven by the magnetic Rayleigh-Taylor instability.

The possibility of the existence of undamped oscillations of the electric current in coronal magnetic loops and loop arcades due to the presence of a photospheric electromotive force arising in the base of the coronal magnetic loop as a result of the engagement of photospheric convection and the magnetic field of the loop is demonstrated. This photospheric EMF plays the part of negative resistance in the equation of the equivalent electric circuit and leads to a “soft” excitation of electric current self-oscillations. The frequency, amplitude, and phase of the oscillations have been found as functions of the electric current and supercriticality of the photospheric EMF. The possibility of the existence of self-oscillation regimes in arcades of coronal magnetic loops has been considered.

The processes of plasma waves excitation under conditions of a double plasma resonance in a non-equilibrium plasma produced by high-power microwave radiation and confined in an open magnetic trap are studied. Two different dynamic regimes of kinetic instability have been experimentally observed: besides the generation of quasiperiodic series of short (∼50 ns) radiation pulses, a new scenario of instability in the form of generation of a single pulse of large (∼25 μs) duration with a slowly varying frequency near the second harmonic of the electron gyrofrequency in the center of the trap has been discovered. It is shown that the dynamic regimes of plasma wave generation observed in the experiment can arise when the processes of wave excitation and induced scattering compete, and the transition from quasi-continuous generation to pulse-periodic generation is determined by the ratio of the energy of non-equilibrium particles and the temperature of the background plasma. Hereinafter, the studied mechanisms will be used to explain similar phenomena in space, for example, sequences of pulses of different duration in the spectra of solar type-IV radio bursts.

It is shown that a source generating a slowly varying or quiet component of radio emission from ultracool stars such as the brown dwarf TVLM 513-46546 can be the gyrosynchroton radiation from the magnetic loops system distributed quasi-uniformly over the star’s surface. Such a model explains the low modulation of the flux and makes it possible to understand the pumping mechanism of magnetic loops by high energy electrons. The main parameters of magnetic loops and which part of the star’s surface is the emission source are determined using the information on microwave radiation from the brown dwarf TVLM 513-46546.

The nonlinearity of self-oscillatory system limiting amplitude of the generated signal is a source of the higher harmonicas of the base frequency. Harmonicas distort a form of self-oscillations and lower stability of their frequency. In the work the mathematical model of generation of self-oscillations, free from the highest harmonicas strictly monochromatic self-oscillations is offered. The model is based on a method of equivalent (harmonious) linearization, popular in the applied theory of nonlinear oscillations. Numerical realization of the model in discrete time has allowed to formulate two algorithms of generation of monochromatic self-oscillations. One of them includes the procedure of numerical integration of a Cauchy problem for the system of ordinary differential equations. Another reproduces processes in the discrete dynamic system designed on analog model-prototype. The monochromaticity of discrete self-oscillations is confirmed within the numerical experiment.

The results of studies into microporous scaffolds based on polycaprolactone, in particular, involving nanoparticles and microparticles of modified (silicon-containing) hydroxyapatite (hybrid scaffolds) are presented. When hydroxyapatite particles are used during the electrospinning of polymer scaffolds, their porosity is found to increase substantially and a structure with nanofibers and microfibers can be created. X-ray phase analysis demonstrates that the characteristic lines of polycaprolactone and hydroxyapatite exist in the 3D hybrid scaffold structure. According to the data of infrared (IR) spectroscopy of the hydroxyapatitepowder precursor, (SiO4)4– ions are embedded in its lattice. The results of studies into the surface wettability indicate that the contact angles of wetting with water are smaller for hybrid scaffolds than for pure polycaprolactone scaffolds. Adhesive and proliferative activity tests of human mesenchymal stem cells (MSCs) performed upon hybrid-scaffold cultivation on the surface, as well as histologic investigations, indicate the high biocompatibility of the samples. On the basis of a polymerase chain reaction, it is revealed that the differentiation of MSCs occurs in the osteogenic direction. On account of a porous structure, hybrid scaffolds can be employed to recover bone-tissue defects.

The article describes the rare clinical case of transthyretine amyloidosis in young patient, manifested by heart rhythm disturbances and biventricular heart failure.

Ultracool stars usually have active regions, which is confirmed by their high-power radiofrequency emission modulated by the star axial rotation. The interpretation of this emission is commonly based on the electron cyclotron maser mechanism realized in the active regions. A plasma mechanism of radiofrequency emission is not considered, because ultracool star atmospheres are tightly “pressed” against the star surface, and the plasma frequency is much lower than the electron gyrofrequency (fL ≪ fB) at the coronal levels. This paper explores active regions of ultracool stars for the possible existence of a system of coronal magnetic loops carrying electric current generated by photospheric convection. It is shown that current dissipation induces a temperature increase inside the loops to about 107 K, which causes an increase in the scale of height of the inhomogeneous atmosphere and, at the coronal levels, effectuates condition fL ≫ fB, at which the plasma mechanism of radiofrequency emission prevails over the electron cyclotron maser mechanism. The magnetic loop parameters, intensity of electric currents generated by the photospheric convection, and efficiency of plasma heating inside the magnetic loops are evaluated on the example of the brown dwarf TVLM513-46546. The scale of the height of the modified atmosphere, which appears to be comparable to the star radius, is calculated; it is shown that the soft X-ray flow created by the hot modified atmosphere inside a coronal magnetic loop is about equal to that observed for brown dwarf TVLM513-46546.

The effects of the tie-stall and free-stall housing systems on homeostasis and blood rheological properties in the Black-and-White cows in the first half of lactation have been evaluated. One hundred and ninety five healthy third- and fourth-calved cows were analyzed. The erythrocyte parameters of hemostasis, blood viscosity, aggregation, and deformability were assessed. The free-stall housing system for cows has resulted in a significant decrease in the platelet aggregation (by 10.4 and 9.9% for spontaneous and induced platelet aggregation, respectively) along with weakening of the plasma cell adhesion in hemostasis (INR and APTT increased by 6.9 and 23.9%, respectively). A reduction in the blood viscosity value and the erythrocyteaggregation index by 4.9% with a 2.7% increase in their deformability index was revealed. The tie-stall housing system for cows has contributed to the extent of the platelet aggregation (by 15.5 and 34.2% for spontaneous and induced platelet aggregation, respectively) and the activation of hemocoagulation (decreases in INR and APTT by 4.6 and 16.3%, respectively). The obtained results have proven the negative effects of the tie-stall housing system on the recorded rheological properties of blood.

Observations of quasi-periodic intense radio emission at 2–8 GHz from the brown dwarfs with a brightness temperature of up to Tb ∼ 1013 K and with a fairly narrow radiation pattern initiated a series of studies in which the radiation was interpreted in terms of the electron cyclotron maser emission generated by energetic electrons with the “loss cone.” The plasma mechanism of the radio emission was excluded from consideration because it requires that the electron plasma frequency should exceed the electron gyrofrequency in the source of the radio emission, i. e., νp > νc. In this paper, we propose a coherent plasma radiation mechanism for intense radio emission from the brown dwarfs. The possibility of the formation of hot extended coronae in the magnetic loops that occur in the atmospheres of the brown dwarfs as a result of the photospheric convection is shown. The electric currents generated in the magnetic loops by photospheric convection lead to the plasma heating and elevation of the “squeezed” atmosphere. This ensures that the condition νp > νce required for the plasma mechanism of radio emission is fulfilled at the coronal levels. In addition, the pumping mechanism supplying energetic particles into the coronae of the brown dwarfs, which maintain the long-term generation of intense radio emission from these stars, is studied. The parameters of the Langmuir turbulence explaining the observed properties of the radio emission from the brown stars are determined.

Objective To evaluate prospects for clinical use of circulating biomarkers for characterizing fibrotic changes in the myocardium of patients with hypertrophic cardiomyopathy (HCMP) with left ventricular (LV) outflow tract obstruction.Materials and Methods This was a prospective study with a 12-month follow-up period. The study included 47 patients (29 females and 18 males) with obstructive HCMP who were selected for septal reduction. Echocardiography (EchoCG), cardiac magnetic resonance imaging (MRI) and measurements of serum C-reactive protein, N-terminal pro-brain natriuretic peptide, and relevant circulating markers of fibrosis (TGF-β1, MMP-2,-9, TIMP-1, galectin-3, sST2, CITP, PICP, and PIIINP) were performed for all patients. All patients were evaluated at baseline and at 7 days, 6 and 12 months following surgical treatment. Morphometrical analysis of intraoperative biopsy samples was performed for evaluation of the degree of fibrotic changes. Patients received beta-blockers (95.7%), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (34%), loop diuretics (68.1%), aldosterone antagonists (34%), and statins (66%).Results Women with HCMP were older and more frequently had additional risk factors (arterial hypertension). Men had a higher risk of sudden cardiac death. Histological study of intraoperative myocardial biopsy samples showed that the area of fibrotic changes was 13.9±6.9%. According to cardiac MRI mean area of delayed contrast enhancement was 8.7±3.3% of LV myocardial mass. No association was established between traditional cardiovascular risk factors and severity of myocardial fibrotic changes or levels of circulating fibrosis markers. Perhaps that was due to the modifying effect of the drug therapy received by HCMP patients. According to EchoCG maximum pressure gradient in the LV outflow tract before the surgical treatment was 88 (55; 192) mm Hg, and interventricular septal thickness was 22 (16; 32) mm. A considerable decrease (p=0.0002) in the LV outflow tract gradient was observed after myectomy in all patients. At the same time, the left ventricular dimension, which tended to decrease in the early postoperative period, returned to baseline values by the 6th month of follow-up.Conclusion The study confirmed the increase in relevant circulating markers of fibrosis in patients with obstructive HCMP. At the same time, no correlation was observed between levels of circulating biomarkers and severity of fibrosis according to data of histology and cardiac MRI, which was probably due to the modifying effect of drug therapy and limited sampling.

The challenges of ‘standard’ model of solar flares motivated by new observations with the spacecrafts and ground-based telescopes are presented. The most important problems are in situ heating of photospheric and chromospheric loop footpoints up to the coronal temperatures without precipitating particle beams accelerated in the corona, and the sunquakes which are unlikely to be explained by the impact of highenergy particles producing hard X-ray emission. There is also the long-standing ‘number problem’ in the physics of solar flares. It is shown that modern observations favored an important role of the electric currents in the energy release processes in the low solar atmosphere. Particle acceleration mechanism in the electric fields driven by the magnetic Rayleigh-Taylor instability in the chromosphere is proposed. The electric current value I ≥ 1010 A, needed for the excitation of super-Dreicer electric fields in the chromosphere is determined. It is shown that both Joule dissipation of the electric currents and the particles accelerated in the chromosphere can be responsible for in situ heating of the low solar atmosphere. Alternative model of the solar flare based on the analogy between the flaring loop and an equivalent electric circuit which is good tool for the electric current diagnostics is presented. Interaction of a current-carrying loop with the partially-ionized plasma of prominence in the context of particle acceleration is considered. The role of plasma radiation mechanism in the sub-THz emission from the chromosphere is discussed.

We study the possible origin of long-lasting soft X-ray flares on the AD Leo star, which were observed onboard the Extreme Ultraviolet Explorer (EUVE) spacecraft for the period of 1993-2000 [1]. These flares have relatively long rise and decay times of the radiation intensity (τ R ≈ 104 s and τ d ≈ 5 · 103, respectively), as well as a relatively large emission measure EM ≈ 1051cm−3, which exceeds by 1–3 orders of magnitude the emission measure of soft X-ray flares on the Sun. Assuming that the radiation appears in magnetic loops and basing on the observed values of the emission measure and radiation decay time, the authors of [1] determined the typical length $$ \overline{l}\approx 1.5\cdot {10}^{10} cm $$ , electron number density $$ \overline{n}\approx 3\cdot {10}^{11}c{m}^{-3} $$ , and plasma temperature $$ \overline{T}\approx 2.5\cdot 107 $$ K of the loops. This paper considers plasma heating due to dissipation of the electric currents in the coronal magnetic loops of the star induced by the photospheric convection. The large inductance of the loop as an equivalent electric circuit determines the long time of the current rise in the source and explains the observed time of plasma heating and the rise time of the X-ray radiation intensity. It is shown that the parameters of the X-ray sources in the AD Leo atmosphere agree with the parameters calculated under the assumption of simultaneous emission of a great number of loops (about 50) with electric currents greater than 1013 A, which exceeds the electric currents in the solar coronal magnetic loops by 1–3 orders of magnitude. Such an exceeding can be related to the higher photospheric convection velocities on the late-type stars compared with the Sun.

In the all rural tacsons of Dnepro ­ petrovsk region a common tendency – high salt composition of potable water from centralized water sources is observed: general rigidity, dry residue, chlorides, sulfates, calcium, magnesium, iron. The highest content of general rigidity was shown in the water of 1 st tacson: from 143 to 21.2 of MAC for 2008 – 2014 years’ period (p

Reaction of 2,5-substituted 4-hydroxy-6Н-1,3-oxazin-6-ones with 2-hydrazinyl-1,3-benzothiazole in anhydrous polar solvent (methanol) without heating led to the formation of new derivatives of 1,2,4-thiazoles. Screening of biologic activity was performed.