The bed rest experiment involved 6 healthy men aged 24 to 41 years. The subjects were in the supine position for 21 days, the angle of inclination in the cranial direction was -6°. In citrated blood plasma on days 2, 5, 8 and 21 of exposure, as well as 7 days after its end, the following hemostasis parameters were determined: thrombin time, prothrombin time, activated partial thromboplastin time, fibrinogen and D-dimer concentrations, as well as activity of protein C. In comparison with background, there was slight elongation in prothrombin time on the 2nd and 5th days of the experiment, as well as on the 7th day of the recovery period, a slight shortening of the thrombin time on the 8th and 21st days of the experiment and on the 7th day of the recovery period, moderately elongated activated partial thromboplastine time on 5th and 21st day. The concentration of D-dimer was significantly reduced relative to the background in all periods of the survey, except for the 21st day, approaching the background values on the 7th day after the end of exposure. The activity of protein C did not change significantly during the entire experiment and was significantly lower than the background values only on the 7th day after the end of the experiment. The concentration of fibrinogen did not change significantly during all periods of the examination. The results of the study indicate minor changes in the parameters of the plasma component of the hemostatic system, indicating a decrease in procoagulant potential in the early stages of exposure and its increase in the later stages of hypokinesia and in the recovery period.

The structure of the relaxor ferroelectrics PbNi1/3Ta2/3O3 (PNT) was studied by powder X-ray diffraction. The measurements were performed at 313.5 ± 1 K using a powder, which was prepared by grinding PNT single crystals grown by the spontaneous crystallization. The structure refinement and the fitting of the simulated diffraction pattern to the experimental data were performed by the Rietveld method. It was demonstrated that the grown crystals of PNT have a perovskite structure (sp. gr. Pm3m (221), a = 4.02679(2) Å). Polarized Raman spectra of PNT were recorded at room temperature. The main modes of the light scattering spectra were assigned to the Е1 and А1 components of the transverse optical phonon (ТО1) and the А1 component of the longitudinal optical phonon (LO3). The temperature dependence of the dielectric susceptibility shows a broad frequency-dependent anomaly with a maximum at 89 К at a frequency of 1 kHz.

We studied the effects on the human system of plasma hemostasis of sequel rotations on a short-arm centrifuge with equal absolute g value and direction. Participants were 6 normal male volunteers at the age of 25 to 45 years. The volunteers were rotated 7 times in the head-to-pelvis direction (+Gz) at 2.1 g. The first rotation was performed prior to the series; the series of 5 rotations was performed with a 2-day interval between each; the final rotation was performed in 14 days after the series. Citrated plasma was used to investigate the procoagulent component of homeostasis, physiological anticoagulents, and intensity of fibrin formation and fibrinolysis. As compared to baseline data, fibrinogen concentration was increased significantly by 4 % on day 7 post rotations; thrombin time was found decreased by 5 % prior to the 6th rotation. Protein C activity was reduced significantly after rotations 3 and 5 by 8 % and 9 %, respectively. Antithrombin III was reduced by 4 % after rotation 5. Concentration of D-dimer was increased after rotations 5 and 6 by 87 % and 32 %, respectively. Rotations produced minor changes in the levels of pro- and anticoagulents, and also in the intensity of fibrin formation and fibrinolysis, that is these changes were within the physiological norm and reflected adaptive processes in organism.

The structure of the relaxor ferroelectrics PbNi 1/3 Ta 2/3 O 3 (PNT) was studied by powder X-ray diffraction. The measurements were performed at 313.5 ± 1 K using a powder, which was prepared by grinding PNT single crystals grown by the spontaneous crystallization. The structure refinement and the fitting of the simulated diffraction pattern to the experimental data were performed by the Rietveld method. It was demonstrated that the grown crystals of PNT have a perovskite structure (sp. gr. Pm 3̅ m (221), a = 4.02679(2) Å). Polarized Raman spectra of PNT were recorded at room temperature. The main modes of the light scattering spectra were assigned to the Е 1 and А 1 components of the transverse optical phonon (ТО1) and the А 1 component of the longitudinal optical phonon (LO3). The temperature dependence of the dielectric susceptibility shows a broad frequency-dependent anomaly with a maximum at 89 К at a frequency of 1 kHz.

The paper describes the main stages of the protocol and results of a unique 21-day experiment undertaken at the Russian Federation State Research Center Institute of Biomedical Problems of the Russian Academy of Sciences (RAS) (IBMP) under the conditions of Dry Immersion. A cohort of participants consisted of 10 healthy male volunteers (the mean age 29.3 ± 3.56 years). The experiment has demonstrated the feasibility and safety of conducting long-duration immersion exposures, confirming the results obtained during previous shorter exposures, as well as allowed us to describe the dynamics of events during extended chronic stays in the conditions of simulated hypogravity. The accumulated experiences are useful for further research into the efficiency of applying the conditions of simulated microgravity and other prophylactic means as countermeasures against negative effects occurring to human body during extended support and weight unloading.

This paper presents results of a study of temperature dependences of dielectric response and DC and AC - conductivity in single crystals of the relaxor ferroelectric PbNi1/3Nb2/3O3 (PNN) in a wide range of frequencies (10 Hz - 100 kHz) and temperatures (80 - 750 K). Anomalies in the dielectric response in the form of broad frequency-dependent maxima in the vicinity of 153 and 730 K are observed. The thermal activation character of DC conductivity has been obtained, and activation energies determined as Ea = 770 meV (T > 310 K) and Ea = 23 meV (T <310 K). The analysis of conductivity gives reason to assume the existence of local conductivity in the low-temperature region. It is shown that the conductivity character changes above 350 K from the local to the bulk one. Measurement by thermally stimulated depolarization has shown the presence of a residual polarization below 130 K.

In the dynamics of the international experiment with 120-day isolation in the hermetic volume SIRIUS 19, a crew of six people of both sexes aged from 27 to 46 years was examined. The subjects were divided into two groups of three people based on gender. In addition to the impact of the pressurized volume factors, the participants were exposed to a complex of stress factors, particularly, constant intense physical exertion and exercise tests, intense operator performance in the time shortage, 24-h sleep deprivation, and imitation of extravehicular and on-planetary activities. In the blood of the volunteers, the values of 42 biochemical parameters were determined, reflecting the state of the main metabolic components, as well as internal organs and tissues. It was found that metabolic reactions of the participants in the experiment with 120-day isolation in a pressurized volume, in contrast to the previous similar experiments, were determined by the constant stress-generating effect of high-intensity preventive physical exertion and were characterized by an increase in the activity of muscle enzymes, activation of lipolysis, decrease in the level of serum iron, and deceleration of the glomerular filtration rate in kidneys due to an increase in the blood concentration of cystatin C. The gender differences between groups consisted in a greater manifestation of the detected changes in men compared with women. The detected shifts can be interpreted as adaptive.

This paper presents the results of studies of a low-frequency vibration spectrum of PbCo1/3Nb2/3O3(PCN) relaxor ferroelectric crystal using the Brillouin and Raman light scattering in the temperature range from 80 to 750 K. The analysis of the temperature behaviour of the longitudinal acoustic phonon in Brillouin scattering spectra showed no anomalies in the vicinity of 'diffuse phase transition' (T-m= 250 K) in PCN. Polarized Raman light scattering spectra were obtained in PCN over the entire temperature range studied. Analysis of low-frequency optical mode behaviour in PCN during temperature change also revealed no correlations with dielectric permeability anomaly in the vicinity ofT(m): softening of optical phonon at 43 cm(-1)frequency in VV polarization is observed at 170 K. In the same temperature range, there are anomalies (a 'narrow' and weak component) in quasi-elastic light scattering (QELS) obtained in temperature behaviour with VH polarization in Raman spectra in PCN. A 'wide' and intense QELS component, obtained in Raman spectra with VV polarization, shows anomalies in the vicinity ofT(m). We associate the anomalies of optical phonons and QELS with structure distortions in the formation of phase stratification and the dynamics of polar nano-regions.

In this paper, the results of a study of the temperature dependences of dielectric response and conductivity at direct and alternating current in single crystals of PbNi1/3Nb2/3O3 (PNN) relaxor ferroelectric in a wide frequency range (from 10 Hz to 100 kHz) and temperature range (80–750 K) are presented. Dielectric response anomalies in the form of broad frequency-dependent maxima are observed near 153 and 730 K. The ther-moactive type of conductivity is found under the direct current and activation energies Ea = 770 meV for T > 310 K and Ea = 23 meV for T < 310 K are determined. The results of the conductivity analysis give grounds to assume the existence of local conductivity in the low temperature range. It is shown that the conductivity behavior changes from local to bulk conductivity with the increase in temperature starting from 350 K. The temperature range of existence of residual polarization (observed at T < 130 K) is determined by measuring the thermostimulated depolarization current.

The permittivity, conductivity, electric polarization, and features of high-resolution X-ray diffraction scattering of a relaxor ferroelectric PbCo1/3Nb2/3O3 have been investigated in the temperature range 5–350 K. Continuous correlated temperature changes in dielectric properties and electric polarization have been revealed, which were not typical of relaxor ferroelectrics. These changes can be attributed to local polar domains, which were induced in the original crystal matrix. In such domains, the charges (valences) of Co and Nb ions were continuously changed.

The program of the Moon-2015 eight-day experiment simulating a lunar flyby to study the mechanisms controlling the female body adaptation to the conditions of isolation in a hermetically sealed environment (IHE) during interplanetary voyages included the measurement of 42 biochemical indices characterizing the state of organs and tissues, as well as the main metabolic pathways, in six female volunteers aged from 25 to 34 years. Venous blood samples were collected 25 days before the IHE start, 1 h after centrifugation (+Gz, 2 g , 21 min) on a short-radius centrifuge (SRC) before the IHE start, on day 5 of the IHE, immediately after the IHE completion and one hour after centrifugation (+Cz, 2 g , 30 min) upon the IHE completion. The following signs of expressed stress responses were observed after the first centrifugation: the concentrations of glucose, β-hydroxybutyrate (β-HB), and bicarbonate (BC) significantly increased, and the creatine phosphokinase (CPK) activity also increased, which was accounted for by muscle isozymes. Mild symptoms of hypodynamia were observed on day 5 of IHE: the concentrations of glucose, albumin, calcium, and chlorides, as well as the activities of cholinesterase (CHE) and lactate dehydrogenase (LDH), moderately decreased; in contrast, the lipase activity and the magnesium and phosphorus concentrations increased. No significant differences were recorded between the values shown in the majority of indicators after the IHE and the baseline values. The changes due to centrifugation resembled the previous pattern of exposure to hypergravitation (HG), but they were less intense and did not involve all indices, e.g., the values of CPK activity and its muscle isozyme, as well as the β-HB concentrations, did not differ from the baseline values, whereas the BC level decreased, which could be associated with both the hypodynamic effect and a progress in HG training. Thus, HG training on a CFG led to the development of a stress response marked for elevated blood glucose and cholesterol and elevated CPK activity. The living under the IHE conditions even for a limited period of time led to the appearance of metabolic signs of hypodynamia, which were quickly compensated upon the completion of the IHE.

The results of studies of dielectric response and birefringence in the PbNi1/3Nb2/3O3 (PNN) single crystal are presented. An anomaly in the temperature dependence of the complex dielectric permittivity in the vicinity 153 K has been observed. It is shown that the anomaly is attributed to the transition relaxor ferroelectric state. The presence of slightly noticeable anomaly in permittivity in the temperature range of 200-210 K has been confirmed by means of optical birefringence microscopy.

Raman light scattering studies of lattice dynamics of single crystals of relaxor ferroelectric PbNi1/3Nb2/3O3 (PNN) in the temperature range 586-96 K are presented. The measurements revealed the evolution of polarized spectra from the well-known spectra typical of cubic relaxor ferroelectrics in paraphase to more complex ones at low temperatures. During the temperature evolution new lines appeared in the Raman scattering spectra. As shown by the group-theory analysis of the experimental spectra, a cubic phase with the space group (Fm3) can exist at room temperature. The PNN Raman spectra in the low- temperature phase are described within the framework of the space group (P31m), which agrees with the results of X-ray diffraction analysis [K. Kusumoto, T. Sekiya Ferroelectrics, 240, 327 (2000)].