Synthesis and physico-chemical properties of poly(-vinyl pyrrolidone)-based hydrogels with titania nanoparticles.

Poly(-vinyl pyrrolidone) (PVP)-based hydrogels with titania nanoparticles (TN) were synthesized by the sol-gel method for the first time and were characterized in different states (native, freeze-dried, air-dried to constant weight and ground to powder, or swollen to constant weight in HO or DO) by various methods such as wide-angle and small-angle X-ray and neutron scattering, neutron spin-echo (NSE) spectroscopy, and scanning electron microscopy. The static (static polymer-polymer correlation length (mesh size), associates of cross-links and PVP microchains) and dynamic (polymer chain relaxation rate, hydrodynamic polymer-polymer correlation length) structural elements were determined. The incorporation of titania nanoparticles into PVP hydrogel slightly increases the size of structural inhomogeneities (an increase in the static and dynamic polymer-polymer correlation length, the formation of associates of cross-links and PVP chains).

Structure and dynamics of titania - poly(N-vinyl caprolactam) composite hydrogels.

The morphologies and dynamics of poly(N-vinyl caprolactam) (PVCL) based hydrogels with titania nanoparticles in different states (native, air-dried to a constant weight and swollen in HO or DO) are studied by a combination of complementary techniques: wide angle X-ray scattering, small angle neutron scattering, neutron spin echo spectroscopy, differential scanning calorimetry. The results suggest the presence of different structural types of water leading to different properties of the hydrogels. We propose a hierarchical structure of hydrogels spanning from the molecular to the microscopic scale consistent with both the static structure (polymer mesh size, association of the nodes of crosslinks and microchains of PVCL) and the dynamics (rate of relaxation of polymer chains, hydrodynamic polymer-polymer correlation length).

[Dynamics of morphometric parameters of peripheral blood platelets as a criterion in assessing thrombogenicity of dialysis membranes].

The study enrolled 45 patients with terminal chronic renal failure (CRF) aged 24-57 years on hemodialysis (a study group) and 30 healthy subjects of matched age (a control group). Morphofunctional condition of circulating platelets in situ was assessed by vital computer morphometry using computer phase-interference microscope, the analysis was made of opticogeometric parameters and morphological features of live platelets reflecting the degree of their activation. CRF patients' proportion of different platelet types in circulating population was 56.

[Usage of polyvinylpyrrolidonic films for nasal cavity tamponade].

The experience in otorhinolaryngological application of hydrogel films for nasal tamponade in nasal hemorrhage after surgical interventions on the intranasal structures and in nasal hemorrhage in leukemia patients was analysed.