Background. Antiorthostatic hypokinesia (ANOH) reproduces some of the effects of weightlessness on the human body and is used to study adaptation to space flight conditions. It is known that ANOH affects nighttime sleep, but there is no information in the literature on the sequence of occurrence of sleep disorders in ANOH.The aim of the research was to study the dynamics of subjective changes in assessing sleep quality under conditions of antiorthostatic hypokinesia.Materials and methods. Six healthy male volunteers (age from 26 to 34 years) participated in the experiment with 21-day ANOH. They were on a medical bed with a body inclination angle relative to the horizon of –6° for 21 days. To assess sleep quality, a structured questionnaire was used that assessed sleep duration, rate of falling asleep, night awakenings, the presence of daytime sleepiness, and daytime falling asleep.Results. Based on the assessment of the dynamics of the sleep efficiency index (SEI), three stages of adaptation were identified. At the stage of acute adaptation (the first 3 days), there is a decrease in SEI from 96.4 to 91.3 (p < 0.01), a statistically significant prolongation of falling asleep from 17.6 to 33.6 minutes (p < 0.01), an increase duration of night awakenings up to 17.4 minutes, increase in daytime sleepiness by 11 %. In the next 3 days (the “recovery” stage), there is a statistically significant increase in SEI compared to the 1st stage to 94.7 (p < 0.01), but it remains statistically significantly lower than the background values (p < 0.004). The number of complaints about daytime sleepiness increases (up to 42 %), evening bedtime shifts later by 26 minutes. At the 3rd stage (the remaining nights) there is a relative stabilization of the sleep-wake cycle.Conclusion. Under conditions of 21-day ANOH, a gradual change in the pattern of sleep disturbances occurs. The most negative changes in terms of subjective assessment were noted in the first three days. Then there is an improvement in falling asleep, a decrease in night awakenings, combined with an increase in daytime sleepiness and the formation of a schedule with a later bedtime.

OBJECTIVE:To identify valid parameters of heart rate variability (HRV) and musculoskeletal movements based on ballistocardiography data, which allow predicting the sleep efficiency (SE) index in healthy individuals and patients with insomnia. MATERIAL AND METHODS:Ten healthy individuals and 14 patients with chronic insomnia were examined using polysomnography and ballistocardiography. A regression analysis of the data was carried out, as well as a reliability check of the resulting mathematical model. RESULTS:A mathematical model, universal for healthy individuals and patients with insomnia, has been obtained that allows predicting the SE. The greatest significance in the resulting model is the relative activity of the parasympathetic part of the regulation of the autonomic nervous system, determined by the power spectrum of the high-frequency HRV (%), and motor activity during the first and last hours of sleep. Regression reliability testing showed that the mean SE using polysomnography was 82.84, and the mean predicted SE was 83.85, with a correlation coefficient of 0.65. CONCLUSION:Parameters of motor activity and HRV in the first and last hours of sleep, recorded using a non-invasive, accessible ballistocardiography method, make it possible to predict the SE index in healthy individuals and patients with insomnia. The results will allow us to propose this method of analysis to increase the effectiveness of therapy for sleep disorders, as well as their rehabilitation.

One of the symptoms of asthenia in space flight is a decrement of cognitive efficiency, memory and concentration. A demand exists for simple noninvasive methods to forecast appearance of cognitive shifts. It is hypothesized that blood pressure (BP) and heart rate variability (HRV) measured in the morning can predict the psychomotor reactions as at the time of measurement, so in the course of the day (medium-term prediction). The investigation involved 6 volunteers (29-44 y.o.) for a 120-day isolation study. The protocol included 5-min ECG and BP measurement soon after awakening, and HRV evaluation. The classic simple ocular-motor reaction (SOMR) test was performed before and then after midday. Regression analysis of reaction duration and stability showed that SOMR time correlated with the homeostatic parameters (BP, HR); stability of SOCM duration correlated both BP and HR, and parameters reflecting HR regulation processes. Elevated diastolic BP correlated with an increase of reaction duration irrespective of whether the test was performed before or in midday. Elevation of diastolic BP and autonomic balance shift toward the sympathetic activity in the morning correlated with a loss in SOMR stability no matter when the test was performed.

The 120-day isolation experiment (SIRIUS-19 program) within the SIRIUS project ( http://sirius.imbp.ru/ ) involved six volunteers aged 28 to 44 years (three men and three women). Research methods included daily ECG recording to assess heart rate variability, blood pressure measurement, and self-assessment of sleep quality over the past night using a visual analog scale. The studies were carried out in the morning after waking up. Once a week in the evening (17:00–19:00), volunteers filled out a scale of clinical daytime sleepiness self-assessment, which allows the level of sleepiness during the day to be evaluated. During regression analysis, the possibility of predicting the appearance of daytime sleepiness in terms of cardiac activity parameters was assessed. It was found that an increase in heart rate, an increase in PNN50, and a decrease in the Robinson index in the morning predetermine the appearance of subjective daytime sleepiness. It may be suggested that the increased activity of the parasympathetic division of the autonomic nervous system in the morning characterizes both the previous lack of sleep and the risk of developing sleep inertia and daytime sleepiness in general.

Ultrathin ( 10 nm) functional layers of a high-k dielectric, Hf0.5Zr0.5O2 (HZO), precision-doped with lanthanum, were prepared by molecular layering (atomic layer deposition), and capacitor structures based on them were formed. Such doping suppresses the formation of the equilibrium monoclinic phase in HZO and leads to the formation of metastable tetragonal/orthorhombic phases. Electrophysical measurements demonstrate signs of the formation of a morphotropic boundary between these phases and abnormally high, for dielectrics based on HfO2/ZrO2, relative dielectric permittivity (k 58). This quantity consists of the structure post-treatment conditions, namely, on the rapid thermal anneal (RTA) temperature. The maximal dielectric permittivity is reached at the RTA temperature of 550°С, with low leakage currents, <10–7 A cm–2, being preserved. Owing to such combination of properties, the functional layers synthesized show promise as high-k dielectrics in logic device transistors and in random-access memory cells.

The study of proteins - potential markers, associated signal transduction pathways, and their targets - provides a new understanding of the fundamental mechanisms occurring at the level of regulatory processes in the cardiovascular system (CVS), especially in space flight, as well as in model experiments that reproduce its individual effects on the human body. The article presents the results of studies in an experiment with 120-day isolation within the framework of the SIRIUS project in which 6 volunteers aged 28 to 44 years (three men and three women) participated. SIRIUS (Scientific International Research in Unique Terrestrial Station) is the international research project, which studies the issues of biomedical and psychological support of long-term manned space flights. The possible involvement of collagen different types, an extracellular matrix protein, in the mechanisms of autonomic regulation of the CVS was studied. Using chromatic mass spectrometry in urine samples and analysis of heart rate variability, we have established that the extracellular matrix collagen, which is present, in particular, in the structure of the blood vessel wall, are markers associated with the modulating effect of the autonomic nervous system on the regulatory mechanisms of blood circulation. We hypothesized that these proteins may be a biomarker of the autonomic balance in the regulatory mechanisms of the circulatory system. In addition, these proteins can also be markers of the aging process, which increases the risks of developing autonomic dysfunction of the cardiovascular system (dominance of sympathicotonia) and changes in the quality of the tissue of the heart muscle and blood vessels, provoking the development of prenosological conditions and diseases of the cardiovascular system.

На примере стека pSi / H0.5Z0.5O2 (10 нм) / TiN (20 нм) показано, что заряженные дефекты и поверхностные состояния в слое сегнетоэлектрика могут оказывать влияние на результат считывания информации из ячейки памяти.

Urine chromatography–mass spectrometry and a heart rate variability (HRV) analysis were performed in 13 healthy males (age 28 ± 4 years, height 174 ± 1 cm, weight 67.9 ± 1.5 kg). Mathematical and bioinformatics analyses identified the proteins that are associated with the condition of the cardiovascular system and the autonomic regulation of the heart rate in the total protein aggregate. The set included serotransferrin, tyrosine-protein kinase receptor UFO, prostatic acid phosphatase, secreted and transmembrane protein 1, cell adhesion molecule 4, galectin-3-binding protein, immunoglobulin heavy constant alpha 1, matrix remodeling-associated protein 8, and biotinidase. Associations were for the first time studied for protein markers of the heart rate autonomic regulation. Proteomics data were used to describe the indicators of the heart rate physiological regulation in the urine proteome of healthy young males.

The method of deposition from the gas phase is applied to the synthesis of thin films of molybdenum disulfide. It was established that varying the rate of temperature rise in the course of the synthesis affects the character of growth and the structure of the layers formed. With a decrease in the rate of temperature rise, a transition from standard two-dimensional to screw growth of MoS2 films is observed. MoS2 films produced as a result of screw growth have a high density of edge states, which makes them promising for use in catalysis.

The feasibility of growing atomically thin MoS2 films (down to two monolayers) on several tens of cm(2) area was demonstrated by first depositing the MoO3 thin film by using an atomic layer deposition and subsequent sulfurization at temperatures ranging from 500 to 1000 degrees C. The effect of sulfurization temperature on properties of thin MoS2 films was investigated in details. It was found that the annealing of the MoO3 film under the elemental sulfur vapor condition allows effective sulfurization from 500 degrees C, at which the converted MoS2 film contained a rather high concentration of elemental sulfur which might reside at the boundaries between the relatively low-crystallized edge-on MoS2 grains. The increase in sulfurization temperature from 500 to 1000 degrees C results in a significant grain size growth from similar to 10 up to >similar to 100 nm, with the change of the edge-on grains to the flat grains with their (0001) planes being parallel to the sapphire substrate. Raman spectroscopy investigations also indicated that the defect concentration decreased with the increasing sulfurization temperature. The films obtained by the sulfurization at lower temperatures (500-700 degrees C) may have high catalytic activity, whereas the highly (0001) aligned films obtained at higher temperatures (900-1000 degrees C) could be useful for high functionality electronic applications, which was successfully demonstrated by their combination with thin ferroelectric HfO2-based film. Thus, the noticeable remnant polarization value and a good switching endurance were obtained directly in contact with MoS2 film, allowing to conclude the possibility of the memory MoS2-based FeFET concept realization.

The purpose of this work was to reveal the intra- and inter-individual variability of the urine proteomic composition and of biochemical blood parameters in cosmonauts with different preflight autonomic status when they are back to Earth (on the 1st and 7th day after space flight). The objects of the study were 5-min samples of electrocardiogram (ECG) at rest and urine and venous blood samples, obtained in the same timeline from twelve male cosmonauts (age 46.5 +/- 3.4 years), who performed space flights (SF) with duration 169-199 days on-board the Russian segment of the International Space Station (ISS). Two groups with different sympathetic-parasympathetic balance were identified (each consists of 6 cosmonauts) by the results of preflight heart rate variability (HRV) analysis. We have revealed in groups of cosmonauts with preflight predominance of sympathetic or parasympathetic tone the significant differences in the directionality of changes on days 1 and 7 after the SF as compared to the preflight values in three proteins (from total amount around 200): alpha-1 subunit of collagen type VI, Mucin 1, Cadherin-13. A set of biochemical parameters, unidirectionally changing with these proteins, was different in classified groups. Direct bilirubin, potassium and total calcium move unidirectionally with collagen, direct bilirubin, potassium with mucin, and uric acid, ferrum, alpha-1, KFK, potassium - with cadherin in group with a sympathetic tone. Potassium, ferrum, alpha-1 move unidirectionally with collagen, amylase, KFK, AST, urea, inorganic phosphate, glucose, alkaline phosphatase, ionized calcium - with mucin, and total ferrum biding capacity, transferrin, glucose gamma globulin transferase - with cadherin in group with parasympathetic predominance. Probably, differences between groups in the concentration of these proteins and their different relationship with some biochemical parameters reflect different ways to achieve the same goal adaptation to a complex of SF factors and re-adaptation after returning to Earth.

This work demonstrates by in vacuo X-ray photoelectron spectroscopy and grazing-incidence X-ray diffraction that Ru(EtCp)2 and O* radical-enhanced atomic layer deposition, where EtCp means the ethylcyclopentadienyl group, provides the growth of either RuO2 or Ru thin films depending on the deposition temperature (Tdep), while different mechanisms are responsible for the growth of RuO2 and Ru. The thin films deposited at temperatures ranging from 200 to 260 °C consisted of polycrystalline rutile RuO2 phase revealing, according to atomic force microscopy and the four-point probe method, a low roughness (∼1.7 nm at 15 nm film thickness) and a resistivity of ≈83 µΩ cm. This low-temperature RuO2 growth was based on Ru(EtCp)2 adsorption, subsequent ligand removal, and Ru oxidation by active oxygen. The clear saturative behavior with regard to the precursor and reactant doses and each purge time, as well as the good step coverage of the film growth onto 3D structures, inherent to genuine surface-controlled atomic layer deposition, were confirmed for the lowest Tdep of 200 °C. However, at Tdep = 260 °C, a competition between film growth and etching was found, resulted in not-saturative growth. At higher deposition temperatures (300-340 °C), the growth of metallic Ru thin films with a resistivity down to ≈12 µΩ cm was demonstrated, where the film growth was proved to follow a combustion mechanism known for molecular oxygen-based Ru growth processes. However, this process lacked the truly saturative growth with regard to the precursor and reactant doses due to the etching predominance.

The microstructures of amorphous and polycrystalline ferroelectric Hf 0.5 Zr 0.5 O 2 films are studied by X-ray spectroscopy and ellipsometry. EXAFS spectra demonstrate that the amorphous film consists of an “incompletely mixed” solid solution of metallic oxides HfO 2 and ZrO 2 . After rapid thermal annealing, the mixed Hf 0.5 Zr 0.5 O 2 oxide films have a more ordered polycrystalline structure, and individual Hf and Zr monoxide islands are formed in the films. These islands are several nanometers in size and have a structure that is similar to the monoclinic structure of HfO 2 and ZrO 2 . The presence of the HfO 2 and ZrO 2 phases in the Hf 0.5 Zr 0.5 O 2 films is also detected by ellipsometry.

We study the charge transport mechanism in ferroelectric Hf0.5Zr0.5O2 thin films. Transport properties of the leakage currents in Hf0.5Zr0.5O2 are described by phonon-assisted tunneling between traps. Comparison with transport properties of amorphous Hf0.5Zr0.5O2 demonstrates that the transport mechanism does not depend on the crystal structure. The thermal trap energy of 1.25 eV and optical trap energy of 2.5 eV in Hf0.5Zr0.5O2 were determined based on comparison of experimentally measured data on transport with simulations within phonon-assisted tunneling between traps in dielectric films. We found that the trap density in ferroelectric Hf0.5Zr0.5O2 is slightly less that one in amorphous Hf0.5Zr0.5O2. A hypothesis that oxygen vacancies are responsible for the charge transport in Hf0.5Zr0.5O2 is confirmed by electronic structure ab initio simulation.

In this work chemical and electrical properties of TiN films, grown by low temperature plasma-enhanced atomic layer deposition (PE-ALD) process from TiCl4 and NH3, were investigated. Electrical resistivity as low as 250Ohmxcm, as well as the lowest Cl impurity content, was achieved at 320 degrees C. Full-ALD Hf0.5Zr0.5O2-based metal-ferroelectric-metal capacitor with TiN electrodes was fabricated and its electrical properties were investigated. It was also shown that the proposed PE-ALD process provides an early film continuity, which was confirmed by ultrathin fully continuous film growth. Such ultrathin (3nm) and fully continuous TiN film was also successfully implemented as the top electrode to Hf0.5Zr0.5O2-based ferroelectric capacitor. Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) was used for its thickness determination and a visible wake-up effect in underlying Hf0.5Zr0.5O2 layer was clearly observed.

The structural and ferroelectric properties of lightly La-doped (1 mol. %) HfO2 thin films grown by plasma-assisted atomic layer deposition were examined. An annealing temperature as low as 400 °C crystallized the film into the desired orthorhombic phase, which resulted in it displaying promising ferroelectric performance. The remanent polarization (Pr) increased with annealing temperature, but the performance enhancement seemed to saturate at 500 °C. A slight decrease in the dielectric constant, which was associated with the preferential formation of a polar orthorhombic phase at higher temperatures, was also observed. The long-term wake-up effect, i.e., a marked rise in the 2Pr value during field cycling, was demonstrated for films processed at all annealing temperatures. The presence of domain groups with opposite internal electric biases was found in the pristine state, while the internal bias distribution became more uniform during wake-up. The endurance of up to 4 × 108 switching cycles without marked fatigue using bipolar pulses with a duration of 600 ns, and an amplitude of ±3 MV/cm was demonstrated.