The effects of aggressive environments on the mechanical properties of basalt plastics.

A review and analysis of changes in mechanical properties of basalt fibers (BF) and basalt composite materials under effects of aggressive environments in reference to foreign and Russian scientific literature has been carried out. The changes in the physical and mechanical properties of the fiberglass (FG) and basalt plastic (BP) have been compared. The analysis shows that BF is a good alternative to fiberglass for elaboration of composite materials for various purposes. In the most aggressive alkaline environments, BP resistance is higher as compared with that of FG. If required, BF resistance to chemically active media could be increased by midifying its composition and applying protective layers and heat treatment of fibers. For extended use of BP as an effective structural material under various climatic conditions, including in the Arctic, long-term tests of 10 or more years are advisable and relevant, with control of changes in their mechanical parameters and an analysis of processes of climatic aging developing in BP.

Influence of moderately warm and extremely cold climate on properties of basalt plastic armature.

Rods of basalt plastic armature (BPA) of a periodic profile with diameters of 6, 8, 10, 16 and 20 mm on the basis of an epoxy matrix were exposed for 30 months on open stands in a moderately warm marine climate of Gelendzhik and 28 months on similar stands in an extremely cold climate of Yakutsk. For initial and exposed BPA samples, changes of mechanical parameters were determined. After the exposure in Yakutsk, an increase of ultimate compression strength by 4-12% is found, depending on the diameter of rods. After the exposure in Gelendzhik, this indicator decreases by 10-17%. Using methods of thermomechanical analysis and dynamic mechanical analysis, linear thermal expansion coefficient and glass transition temperature of epoxy matrix were measured. In an initial state, a transition from a glassy state to a highly elastic one is discovered: an α 1 -transition at 118 °C and an α 2 -transition at 149 °C. After climatic action, there were detected a shift of α 1 -transition to low temperatures and a shift of α 2 -transition to higher temperatures. Reasons for the change of temperatures of transitions are weakening of a molecular layer and post-curing of the epoxy matrix in a surface layer. These effects are accompanied by an increase of the linear thermal expansion coefficient, moisture diffusion coefficient and maximum moisture saturation after the climatic action on BPA. Fractographic studies discovered presence of pores in a structure of BPA with sizes up to 10-20 µm, a quantity and size of which increase by 20-40% after the climatic action. In general, the studied BPA has high climatic stability and can be used for a long time under the extreme climatic conditions.

[Detection of herpesvirus markers in patients with precancerous lesions of the lungs and stomach]. / Rezul'taty vyiavleniia markerov gerpesvirusov u patsientov s predrakovymi zabolevaniiami lëgkikh i zheludka.

Blood-serum concentrations of antibodies to such viruses as herpes simplex virus, cytomegalovirus and Epstein--Barr virus have been assayed versus frequency of viral DNA detection in blood and saliva suspensions from patients with lung and stomach pre-cancers. Condition of local immunity of oral mucosa was assessed on the basis of saliva levels of secretory IgA and lysozyme. It was found that as local immunity of oral mucosa deteriorated, irrespective of pre-cancer localization, high titers of antiviral antibodies (class G) were established. The frequency of herpes DNA was much higher in lymphocytes and cellular sediment from saliva of patients with gastric pre-cancers. The role of herpes viruses in the pathogenesis of precancerous diseases and malignances is discussed.

[Cellular content of mixed saliva sediment in patients with chronic mucosal inflammation]. / Kletochnyi sostav osadka smeshannoi sliuny u patsientov s khronicheskimi vospalitel'nymi protsessami na slizistykh obolochkakh.

A comparative analysis was made of the saliva sediment cell composition in healthy patients and patients with chronic mucosal inflammation. Migration of leucocytes to the oral cavity was registered in patients with chronic inflammatory processes. A reliable increase in the number of epithelial cells with high degree of destruction was determined in saliva in addition to the appearance of cubic epithelial cells. These results indicate certain violation of epithelial reparation. It is proposed to use a quantitative analysis of saliva sediment for estimating functional conditions of mucosa.

[Autoimmune reactions in patients with various tumor localizations]. / Autoimmunye reaktsii u patsientov so zlokachestvennymi novoobrazovaniiami razlichnykh lokalizatsii.

Autoantibody levels in patients with malignancies of the oral cavity and lung and autoimmune disorders have been assayed. It was found that tumors initiated polymorphous autoimmune reactions to various tissue antigens. Autoantibody production rates in tumor patients were comparable with those in autoimmune disorders. The role of autoimmune reactions in cancer pathogenesis is discussed.

[Intensity of the humoral immune response to herpesviruses as an indicator the body immune deficiency]. / Intensivnost' gumoral'nogo immunnogo otveta k gerpes-virusam kak indikator immunologicheskoi nedostatochnosti organizma.

The state of the local immunity system of the oral cavity was studied by the level of saliva immunoglobulins in patients with different processes on their mucous membranes: herpetic infection, respiratory allergosis and malignant tumors of the mouth cavity and the laryngopharynx. The suppression of the production of sIgA, was accompanied by the enhanced production of antibodies to the most widespread herpesviruses (herpes simplex virus, cytomegalovirus and Epstein-Barr virus). The maximum levels of serum IgG to herpesviruses were determined in patients with malignant tumors. The role of herpesviruses in the pathogenesis of immunodeficient states is discussed.