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.

[The correlations of the basic indices of central and renal hemodynamics in patients with a single allograft kidney].

A simultaneous assessment of relationship of central and renal hemodynamic parameters has been performed in patients with a renal transplant of different functional performance. Radionuclide routine techniques of one-passage radiocardiography and indirect renal angiography in single bolus intravenous introduction of radiopharmaceutical were used. Three groups of patients were identified according to functional capacity of the renal transplant: 15 patients with satisfactory function of the transplant for 85 days on the average (group 1); 8 patients with unstable function of the transplant for 155 days (group 2); 7 patients with poor function of the transplant for 375 days on the average.

[The use of xidifon for the correction of phosphorus-calcium metabolism in patients in the terminal stage of chronic kidney failure who are on programmed hemodialysis].

Correction of impaired phosphoric-calcium metabolism was performed in 15 hemodialysis patients with terminal chronic renal failure (TCRF). For this purpose a synthetic analogue of pyrophosphoric acid xidiphone produced in Russia was used (2% aqueous solution 1 tablespoon 3 times a day 0.5 h before meal for 2-3 months).

[A new method of immobilizing proteolytic enzymes in polymeric hydrogels].

A novel one-step method for enzyme immobilization in composite gels based on the thermally reversible polymer poly (N-vinyl-caprolactam) was developed. Conditions for entrapment of trypsin and carboxypeptidase B in the gels were optimized. After immobilization, 80 and 90% of the original carboxypeptidase B and trypsin activities, respectively, were found to retain.

[A comparative evaluation of the central hemodynamic indices in patients with the terminal stage of kidney failure during dialysis therapy and allografting].

Changes of the functional indices of central and intracardiac hemodynamics during treatment with hemodialysis or peritoneal dialysis, as well as after cadaver kidney transplantation, were studied in 44 patients with the terminal stage of chronic renal failure by means of radiocardiography with 131I-albumin. The signs of cardiac insufficiency were evaluated according to the classes of the cardiologists' New York classification accepted in 1964. Four groups of patients were distinguished during the analysis: group 1-10 patients given intravenous detoxification therapy; group 2-19 patients treated by chronic programmed hemodialysis; group 3-4 patients kept on peritoneal dialysis; group 4-11 patients after allotransplantation of cadaver kidney.