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The study is devoted to the study of the emotional state of people in the conditions of self-isolation during the pandemic of a new coronavirus infection. The online study involved 380 «conditionally healthy» respondents aged 18 to 60 years. A special questionnaire was developed; to assess the emotional state of the subjects, the Hospital Anxiety and Depression Scale (HADS) and the Bass-Darkey aggressiveness level questionnaire were used. Only 45–54% of respondents tried to comply with the sanitary regime, men violated the established requirements more often than women. No clinical symptoms of anxiety or depression were found. The level of anxiety reached subclinical values in women. At the same time, there was an increased level of aggression (verbal and indirect) and irritation, an increase in the integral indicators of aggressiveness and hostility. These emotional manifestations characterize the well-known reactions of a person’s mental maladaptation in difficult life situations.

A conductometric method for quantitative determination of the volume fraction of added distilled water to mineral water is proposed based on the analysis of the dependence of the specific electrical conductivity of solutions prepared on the basis of Borjomi mineral water on the degree of its dilution with distilled water. The technique is fully consistent with the principles of “green” chemistry, since the “waste” is mineral water diluted with distilled water.

The effect of cholinolytics inhibiting the transmission of signals in the cholinergic system on the rate of feeding reaction of juvenile carp Cyprinus carpio L. has been studied. We have revealed differences in the rate and duration of the impacts of cholinolytics affecting M- and N-cholinergic receptors on one of the parameters of the feeding behavior of fish: the rate of feeding reaction. The administration of the highest rate (1.0 mg/kg of fish weight) of some substances results in the maximal increase in the latent feeding time (or a decrease in the rate of the feeding reaction) of fish: by 710 and 224% in 1.5 h upon the use of atropine and metacin, respectively, and 249% in 30 min after pentamine administration. The period of return to the norm is 9 h for atropine and metacin and 8 h for pentamine. A decrease in the dose of all studied cholinolytics causes a dose-dependent decrease in the period of their action and in the feeding latent time. Different rates of the decrease in the rate of feeding reaction at the administration of cholinolytics of predominantly central (atropine) and peripheral (metacin and pentamine) effect testify to the dependence of this parameter on their effect on M- or N-cholinergic receptors.

The results of studying the locomotor activity and swimming performance of juvenile roach Rutilus rutilus at temperatures (7, 16, 25, 28, and 31°C) covering most of the temperature tolerance range of this species are presented. The maximum values of the distance swam and the swimming speed of individuals in an “open field”, the critical water velocity and time to fatigue in a hydrodynamic installation were recorded at a temperature close to the optimum temperature (25°C) for juvenile roach. A greater temperature dependence of the purposeful locomotor activity of juvenile roach was revealed compared with a spontaneous one. High values of swimming performance of 0+ roach in a very wide temperature range reflect good adaptability to life in a temperature-inhomogeneous coast.

Temperature and available food are among the key factors affecting fish during their lifetime. The interaction between foraging and thermoregulatory behavioral responses was studied in experimental conditions using 1+ perch individuals. The behavior of fish was examined in a thermally heterogeneous environment with varying levels of food availability: “excessive” (food objects constituted 20% of the overall fish weight in each compartment of the experimental device), “limited” (3%), and “zero” (0%). The values of the final preferred temperatures revealed in these conditions differed significantly: 26, 24, and 22°С, respectively. In the conditions of excessive food, fish locomotor activity was minimal. The food of juvenile fish consumed over 15 minutes was independent of the number of food objects (20 and 3%) in the experimental device, constituting 14.2 and 15.2% of the fish body weight, respectively. However, fish growth was observed only in the first case, probably due to the higher locomotor activity needed to find and obtain food in the environments with fewer food objects. The data presented may be useful for estimating the dominant forms of behavior of juvenile fish both in experimental and field conditions.

The tolerance of juvenile Amur sleeper Perccottus glenii and perch Perca fluviatilis to the effect of piscivorous predator pike Esox lucius has been studied in experimental conditions. In the majority of trials, Amur sleepers were consumed by pike much more efficiently. This trend remained in the aquaria of various volumes, with and without covers. As opposed to perch, juvenile sleeper do not rely on the behavioral responses of group defense, and this leads to its higher vulnerability to predation in the experimental conditions. The data of the present study confirm the results of field research on the key effect of piscivorous predators on the possibility for colonization of Amur sleeper in certain waterbodies.

The paper offers a phenomenological model of volume self-diffusion and interstitial diffusion at high (T > TD) and low (T TD experiment and show a dramatic increase in the activation energy at T

The authors propose a phenomenological description of volume diffusion in oxide ceramics. The paper considers vacancy and non-vacancy mechanisms of diffusion. In vacancy models, ion migration is described as a fluctuation with formation of a "liquid" corridor that facilitates diffusion transfer of ions through the melt or a fluctuation with formation of a "hollow" corridor where ion movement is activation less. Non-vacancy models concern a fluctuation with formation of a liquid spherical area of a size that corresponds to the first coordination sphere. It has been demonstrated that the vacancy models are fit for cubic metal oxides and the non-vacancy model works well to describe diffusions in non-cubic oxides. The developed modes have been rigorously compared against experimental data, which revealed that diffusion activation energies of metal ions and oxygen ions calculated using the proposed models are in good agreement with the published values for volume diffusion in stoichiometric oxide ceramics.

The mechanisms for the sintering of ultrafine-grained 95%W–3.5%Ni–1.5%Fe heavy tungsten alloy powders have been investigated. It has been established that a decrease in the activation energy of grain boundary diffusion and the formation of a nonequilibrium solid solution of nickel and iron in the surface layer of tungsten particles upon high-energy ball milling are responsible for the decrease in optimal sintering temperature.

The paper dwells on the research conducted into high-rate consolidation of pure tungsten carbide (WC) nanopowders using the Spark Plasma Sintering technology. Studies included the effect that the original size of WC nanoparticles and their preparation modes have on density, structure parameters, and mechanical properties of tungsten carbide. Samples of high-density nanostructured tungsten carbide characterized by high hardness (up to 31–34 GPa) and improved fracture toughness (4.3–5.2 MPa m 1/2 ) were obtained. It has been found that materials that show abnormal grain growth during sintering have lower values of sintering activation energy as compared to materials the structure of which is more stable during high-rate heating. A qualitative model is proposed that explains this effect through the dependence of the grain boundary diffusion coefficient on the grain boundary migration rate.

The influence of severe plastic deformation on the structural-phase state of grain boundaries in a Ti–4Al–2V (commercial PT3V grade) pseudo-alpha-titanium alloy has been studied. It is established that increase in the strength, plasticity, and corrosion resistance of this alloy is related to the formation of an ultrafine- grained structure. In particular, it is shown that an increase in the resistance to hot-salt intergranular corrosion is due to diffusion-controlled redistribution of aluminum and vanadium atoms at the grain boundaries of titanium formed during thermal severe plastic deformation.

The review deals with the problem of venous trophic ulcers. Current data on epidemiology and social significance of this condition are presented with special reference to pathogenetic aspects of its development, such as systemic immunity disorders associated with chronic venous insufficiency. The necessity and possibility of correction of some of them are discussed.

The influence of the structural-phase state of grain boundaries in a Ti4Al2V (commercial PT3V grade) pseudo-alpha-titanium alloy on its susceptibility to hot-salt intergranular corrosion (IGC) has been studied. It is established that IGC-tested alloy samples exhibit corrosion-induced defects of two types. More extended defects of the first type occur at the V-rich boundaries of coarse grains, while short defects of the second type reside at the grain boundaries with composition close to that of the grain body. The existence of the two types of IGC defects is explained by the classical theory of galvanic microcouples (microcells), according to which the IGC intensity is proportional to the difference of corrosion-active impurity concentrations between the grain boundary and body.

Phenomenological description of bulk diffusion in oxide ceramics has been proposed. Variants of vacancy and vacancy-free diffusion models have been considered. In the vacancy models, ion migration is described as a fluctuation with the formation of a “liquid corridor,” along which the diffusion ion transport in a “melt” is performed, or, as a fluctuation with the formation of an “empty corridor,” in which the ion motion proceeds without activation. The vacancy-free model considers a fluctuation with the formation of a spherical liquid region whose sizes correspond to the first coordination sphere. It has been shown that both the vacancy models work in cubic metal oxides and the vacancy-free model is effective for describing diffusion in oxides having a noncubic structure. Detailed comparison of the models developed has been performed. It has been shown that the values of the activation energies for diffusion of metal and oxygen ions agree with the published data on bulk diffusion in stoichiometric oxide ceramics.

The paper describes the results of experimental studies of the effect of small chromium additives on the temperature of recrystallization (TR) of ultrafine-grained (UFG) copper obtained by equal channel angular pressing. Our investigation shows that the process of recrystallization in UFG CuCr copper alloys has a three-stage character - anomalous grain growth at annealing temperatures not exceeding the temperature of chromium particles(Tann1), “fixation” of grain boundaries by the released particles (T1⩽Tann2), and regular grain growth at higher temperatures (Tann⩾T2), when grain boundaries “detach” from particles of the second stage. It also shows that an increase in the chromium concentration in UFG copper by 0.3-0.5wt.% leads to a decrease in the temperature of the onset of the migration of grain boundaries T1 in the UFG copper by 40-60°C and an increase in temperature T2 to ∼ 400°C. We discovered that low-temperature pre-recrystallization annealing contributes to an increase in the thermal stability of the mechanical properties of CuCr alloys.

High-density samples of ultrafine-grained tungsten carbide with high hardness (up to 31–34 GPa) and increased fracture toughness (up to 5.2–6.4 MPa m1/2) are obtained using the technology of electropulse plasma sintering. The influence of the initial size of nanoparticles of α-WC prepared by plasmachemical synthesis on the density, structural parameters, and mechanical properties of tungsten carbide is investigated.

Spark Plasma Sintering studies of the high-speed consolidation of pure tungsten carbide WC nanopowders have been carried out. The influence of the initial size of the WC nanoparticles and modes of their receiption the density, structural parameters, and mechanical properties of tungsten carbide are studied. Samples of high-density nanostructured tungsten carbide with high hardness (up to 31–34 GPa) and an increased crack resistance (4.3–5.2 MPa m1/2) are obtained. It is found that the effect of accelerating tungsten carbide nanopowder sintering under conditions of high-speed heating is associated with the acceleration of diffusion along grain boundaries in the sintered material. It is shown that the nonmonotonic dependence of the optimal sintering temperature on the initial grain size is caused by a change in grain-boundary diffusion coefficient in conditions of abnormal grain growth. It is found that the size of abnormally large grains in spark plasma sintering depends on the volume fraction of particles of the nonstoichiometric phase.

Ultrafine-grained (UFG) tungsten carbide (WC) samples with high hardness (up to 34 GPa) and increased cracking resistance have been obtained by the method of spark plasma sintering (SPS). Initial powders have been prepared by two-stage plasmachemical synthesis. The influence of the initial size of WC nanoparticles on the density, structural parameters, and mechanical properties of UFG tungsten carbide obtained by SPS has been studied. It is established that the phenomenon of accelerated sintering of WC powder is related to enhanced grain-boundary diffusion.

The effect of the decomposition of the solid solution in Al-X wt % Mg-0.22 wt % Sc-0.15 wt % Zr (X = 0, 1.5, 4.5 wt %) alloys on their mechanical properties in the as-cast and microcrystalline (MC) states is studied. The contribution of the particles that precipitate during the decomposition to the mechanical properties of the as-cast and MC alloys is determined. For this purpose, the dependences of the volume fraction and the size of the particles precipitating during the decomposition on the annealing time and temperature and the magnesium content in the as-cast and MC alloys are calculated. An additional contribution to the hardening of the MC alloys is shown to be related to the internal stress fields created by the defects that accumulate at the disperse particles distributed in grain boundaries during grain-boundary migration. The calculated macroelasticity limits in the as-cast and MC alloys are compared with the experimental data.

In recent years a considerable decrease in the abundance of predatory fishes has been observed in spawning tributaries of the Rybinsk Reservoir caused by their intensive catching. The lack of encounters with predators before the downstream migration of young fish hampers the development of necessary skills of defensive behavior in the absence of predation experience. As a result, after downstream migration, the juveniles are incapable of adapting to the predation pressure in the reservoir and are subjected to intensive elimination. The adaptive potential of the roach Rutilus rutilus L. was experimentally studied in siblings raised from the larvae to the late fry stage both in the presence and absence of a predator. It has been found that the fry that was raised under different conditions differed in their adaptive potential in new environment conditions.

The results of experimental studies of the decomposition of the solid solution in cast and microcrystalline (MC) Al-X wt % Mg-0.22 wt % Sc-0.15 wt % Zr (X = 0, 1.5, 4.5) aluminum alloys that were described in part I of this work are analyzed. The data on the electrical resistivity of the alloys are used to determine the volume fraction of Al3Sc(Zr) particles precipitating in the temperature range 240–400°C. The model developed in part II of this work is used to reveal the mechanism of particle precipitation in the cast and MC alloys. It is shown that the particles in the cast and MC alloys precipitate mainly on dislocations. The differences in the decomposition kinetics of the solid solution in the cast and MC alloys are explained by different mechanisms of dislocation structure recovery mechanisms occurring in them.

A model is proposed to calculate the kinetic parameters of the precipitation of coherent second-phase particles from a supersaturated solid solution. This model is based on the assumption of barrier-free nucleation of coherent particles. In this case, the decomposition rate of a solid solution and the particle precipitation kinetic parameters are mainly determined by the characteristics of nucleus diffusion growth. The decomposition kinetics of a solid solution during the precipitation of coherent particles is described by the Johnson-Mehl-Avrami-Kolmogorov equation W = 1 − exp[-(t/τ)n], where W is the degree of decomposition and τ = τ0exp(Q/kBT) is the decomposition time. The values of parameters n and Q characterizing the decomposition kinetics are determined. Expressions are derived to describe the dependences of the volume fraction and size of precipitating coherent particles on the supersaturation of a solid solution, the annealing temperature and time, and the thermodynamic and diffusion parameters of a material.

The structure and the electrical and mechanical properties of Al-Mg-0.22 wt % Sc-0.15 wt % Zr alloys with various magnesium contents (0, 1.5, 4.5 wt %) are experimentally studied during the decomposition of the solid solution of scandium and zirconium in the states after solidification from a melt (cast ingots) and after subsequent multicycle equal-channel angular pressing (microcrystalline structure). The dependences of electrical resistivity ρ, microhardness HV, macroelasticity limit σ0, and yield strength σy on the annealing temperature and time are analyzed.

The effect of thyroid hormones (THs) on the formation of behavioral responses in juvenile roach was studied. Eggs taken from one pair of spawners were split into three groups and kept in different environments: a clean water control, with the addition of a hormone, and with the addition of a substance blocking thyroid-gland synthetic activity. It was revealed that control fish and those with an enhanced hormonal status manifest more mature behavior than the fish with a lowered hormonal status.

A phenomenological model has been proposed for bulk self-diffusion and diffusion of interstitial atoms in the ranges of high (T > T D) and low (T < T D) temperatures (where T D is Debye temperature). It has been shown that the mechanisms of diffusion at high and low temperatures differ significantly. In the high-temperature range, the diffusion is provided by fluctuations, which can be described in terms of local melting, i.e., the formation of a “liquid diffusion channel.” In the low-temperature range, when melting for some reasons is hindered, the diffusion is due to the fluctuation formation of a “hollow diffusion channel.” The calculation of the activation energies of these processes in the case of self-diffusion agrees well with the experiment in the temperature range T > T D and has demonstrated that the activation energy increases significantly at T < T D. The calculation of the activation energy for diffusion of interstitial atoms in bcc metals agrees well with the experiment in the entire temperature range and provides an explanation of the decrease in the activation energy of diffusion at low temperatures.

The behavior of juvenile 4.5-month-old roach Rutilus rutilus (L.) raised (starting on the 12th day after hatching) at different levels of habitat informational diversity (feeding with live and immobilized zooplankton and benthos, the presence of a predator, and a constant water flow in the nursery aquarium) was studied. The fish’s exploratory behavior and locomotor activity were tested in a circular chamber; swimming activity was tested in a hydrodynamic conduit. It was experimentally shown that juvenile roach raised in the presence of a predator differed significantly (p < 0.05) in regards to behavioral characteristics from the fries raised in a water current and in conditions of a high level of environmental deprivation.

The feeding and defensive behavior of juvenile roach Rutilus rutilus (offspring of one pair of spawners) that were held at early stages of ontogenesis under conditions of differently enriched environments was studied. After the beginning of active swimming (the 12th day upon hatching), roach were reared for 95 days under different environmental conditions (feeding on active or immobilized organisms, the presence or absence of constant water flow, and the presence or absence of a predator), after which comparison of the efficiency of feeding behavior in the presence of a predator in juveniles of different groups was performed. It was established that the degree of environmental richness at early stages of ontogenesis exerts a determining effect on the formation of habits of defensive and feeding behavior. The most efficient behavior was observed in individuals that were held together with the predator during rearing.

The effect of small chromium additions on the temperature of the onset of recrystallization in microcrystalline copper produced by equal-channel angular pressing was studied. The introduction of 0.3–0.5 wt % chromium is shown to decrease this temperature by 40–60°C. The effect of chromium on the diffusion properties of grain boundaries and the temperature of the onset of recrystallization in microcrystalline copper is calculated in terms of the theory of nonequilibrium grain boundaries. The calculation results are compared with experimental data.

The paper dwells on the research conducted into high-rate consolidation of pure tungsten carbide nanopowders using the Spark Plasma Sintering. Studies included the effect that the original size of WC nanoparticles and their preparation modes have on density, structure parameters, and mechanical properties of tungsten carbide. It has been found that materials that show abnormal grain growth during sintering have lower values of sintering activation energy as compared to materials the structure of which is more stable during high-rate heating. A qualitative model is proposed that explains this effect through the dependence of the grain boundary diffusion coefficient on the grain boundary migration rate.

The study was aimed at comparatively assessing the efficacy of treatment for venous trophic ulcers at stages II-III of the wound process using special compression knee-length socks of the ULCER X kit (Sigvaris AG, St. Gallen, Switzerland) and long-stretch bandages Lauma. Compression therapy was included into the programme of outpatient treatment of forty 31-to-74-year-old patients presenting with trophic ulcers (stage II-III of the wound process) with an average area of 5,36±1,1 cm2. The Study Group consisting of 20 patients used compression knitted fabrics in the form of knee-length socks ULCER X and the comparison group (n=20) used long-stretch bandages Lauma.The obtained findings (6 months) demonstrated that using compression therapy exerted a positive effect on the process of healing of venous trophic ulcers, also proving advantages of compression therapy with the knee-length socks ULCER X that create an adequate level of pressure on the crus and maintain it in long-term daily use, reliably accelerating the healing of venous trophic ulcers as compared with elastic long-stretch bandages. The use of long-stretch elastic bandages in treatment of venous trophic ulcers turned out to be not only ineffective but fraught with a possibility of the development of various complications. During 6 months of follow up the patients using the special knee-length socks ULCER X were found to have 80 % of ulcers healed (16 patients), mainly within the first 2 months, whereas using elastic bandages resulted in only 30 % of healing (6 patients) by the end of the study. Along with it, we documented a considerable decrease in the malleolar circumference in the study group patients (from 30,05±0,78 to 28,35±0,86 cm) and in the control group from 31,2±30,35 to 30,25±0,75 cm), accompanied and followed by more than a two-fold increase in quality of life of the patients along all the parameters in the study group and a 1.4-fold increase in the control group patients.

A heart of gold: The first hexanuclear gold cluster formed exclusively by gold(I) centers (see picture; Au?yellow, C?black, P?purple) has been shown to be catalytically active for the activation of alkynes under homogeneous conditions.

We present a case of cardiac angiosarcoma in a pregnant women. Clinical manifestations of angiosarcoma were unspecific and progressed rapidly as hemopericardium, cardiac tamponade, heart failure, fever, chest pain. Pregnancy was interrupted at 22-nd week. The patient died in 6 months after appearance of first symptoms.