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AIM: To work out the technique of saturation of the preserved amniotic membrane (AM) with platelet rich plasma (PRP) lysate and to evaluate the growth-stimulating effect of a combination of AM and PRP lysate in vitro. MATERIALS AND METHODS: In the experiment, AM samples preserved in 3 ways were used: silicate drying, lyophilization, cryopreservation. PRP lysate was prepared on the basis of volunteers blood. During the exposure of AM with PRP lysate, the optimal saturation time of canned AM with lysate was determined, the volume of lysate that 1 cm2 of AM could adsorb was estimated. The growth-stimulating effect of AM transplants was evaluated in the culture of human buccal epithelium. The dynamics of cell growth was evaluated after 1, 2 and 3 days from the moment of sowing. RESULTS: In the presence of PRP lysate, the mass of silicatedried AM increased 4.2 times, lyophilized AM 4.8 times, cryopreserved AM 1.8 times. AM samples obtained by lyophilization adsorbed PRP lysate most effectively. Five minutes of exposure with PRP lysate are enough to fully saturate the AM. AM without PRP lysate did not give a growth-stimulating effect. CONCLUSIONS: When comparing experiments with PRP lysate without AM and AM with PRP lysate, it was found that the greatest stimulation of cell growth occurred when using lyophilized AM and PRP lysate. Saturation of cryopreserved AM with PRP lysate was ineffective, and when using silicate-dried AM impregnated with PRP lysate, the greatest growth-stimulating effect was observed on the 1st day.

Experiments at the multimirror open trap as plasma emitter of THz radiation (GOL-PET) facility have shown that the injection of a relativistic electron beam (REB) with a kiloampere current into a magnetized plasma column is accompanied by the generation of a THz radiation flux. Our experiments have revealed three-generation mechanisms. The first mechanism is the scattering of upper hybrid waves on plasma density gradients, the second is the direct pumping of electromagnetic waves by an electron beam, and the last one is the merging of two upper hybrid waves into an electromagnetic one. Both theoretical and experimental studies have shown the possibility to achieve a megawatt power of the flux at the upper hybrid frequency in the presence of significant plasma density gradients. Resent experiments have shown that a strong density decrease at the end of the plasma column is necessary for high-efficiency emission of the generated flux along its axis. This THz radiation flux is emitted from the column into a vacuum chamber and then through an output window to the atmosphere. The measurement results of the spatial and angular properties of such a megawatt flux are described in our article.

We studied morphofunctional properties of human platelets, treated with low doses of hydrogen peroxide (H2O2). It was shown that platelet incubation with 20 - 75 μM H2O2 during 24 hours at 20°C - 22°C did not cause visible structural deficiencies in cells. Platelets maintained their adhesion activity and velocity of degranulation at 20 μM H2O2. 30 - 60 μM H2O2 dose-dependently reduced lamella’s growth and allowed retaining granule bulk inside cytoplasm of spreading platelets. After 1 - 2 hours, the most effect of platelet granules’ stabilization was registered at samples, previously incubated with 60 μM H2O2. Adrenalin activation led to rapid degranulation of stabilized platelets, whereas lamella’s growth in activated platelets was low or medium.

Submillimeter wave generation due to the intense interaction of a relativistic electron beam (REB) with magnetized plasma is studied at GOL-PET facility. In a plasma column with density ~ 1015 cm-3 the e-beam (0.5 MeV/15kA/6μs) generates a well-directed 1 mm wavelength flux of ~ 10 MW power. Paper presents measurement results of the radiation spectral composition in 0.1 – 0.6 THz band and the energy distribution function of the beam electrons at various plasma density distributions. The obtained results are discussed in the consideration of theoretical models.

Experiments at the GOL-PET facility have shown that injection of a relativistic electron beam at kiloampere current into a magnetized plasma column with strong radial density gradients is accompanied by generation of THz radiation flux which power estimated at the level of several megawatts. Extraction of this flux along the axis of the beam-plasma system is essentially increased in case when the end of the plasma column is separated by a vacuum gap from the wall of a plasma chamber. Results of measuring the spatial and angular properties of such megawatt flux of THz radiation going out from the plasma to an air of the experimental hall are described in our paper.

A series of experimental studies on the four-point bending of sandwich specimens with facing layers made of a unidirectional fiber-reinforced composite with specified geometric and physico-mechanical characteristics with varying geometric and physico-mechanical characteristics of the core was carried out. It is shown that when using a honeycomb core made of polymer paper, the implementation of the shear buckling mode in the facing layers is impossible, and the failure of the sample occurs due to the failure of the core. Specimens with stiffer cores are fail due to the failure of compressed facing layers in the vicinity of the loading roller at stresses comparable to the critical stresses of their buckling mode in a purely transverse-shear form. It was established that during the loading of the specimen, a significant increase in the mulitmodularity of the material is observed, apparently, mainly due to the implementation and continuous change of the internal micro- and mesoscale buckling modes of fibers and fiber bundles in areas with weakened physical and mechanical characteristics of the binder composite in compressed facing layer.

Project of powerful submillimeter wave generator based on intense interaction of a relativistic electron beam with a magnetized plasma is developed at BINP RAS in collaboration with NSU. In presented experiments, the beam with parameters 0.8 MeV/15 kA/6 μs is injected into a plasma column with the density ∼ 1015 cm-3. Spectral composition of the emission from the plasma column is studied in the frequency band 0.1 – 1 THz. In the analysis of the results of our studies we focus on the role of strong plasma density gradients in generation of sub-mm waves.

Results of studies of films and nonwoven membranes made of a copolymer of 3-hydroxybutiric and 4-hydroxybutyric acid (P(3HB/4HB)) as a models for wound dressings are presented. Structure and properties of P(3HB/4HB) product surface and mechanical properties depending on production method and ultrafine fibers orientation of nonwoven membranes obtained by electrospinning are studied. It is shown in cultures of mouse fibroblasts NIH 3T3 and diploid cells of human embryonic lines M-22 all the investigated P(3HB/4HB) samples are biocompatible, not cytotoxic in direct contact with cells and provide high adhesion and cell proliferation, as well as maintaining a high physiological activity up to 7 days. The P(3HB/4HB) film samples and the nonwoven membrane are suitable as biotransplantats and wound coverings.