Changes in Cognitive Functions of Pupils under Conditions of Iodine Deficiency

Clinical and physiological examination of 38 children which latent hypothyroidism (the main group) and 176 apparently healthy persons of intact region (the control group) at the age from 8 to 17 years living in endemic region was carried out. To determine the functional state of the thyroid gland in blood serum the content of total triiodothyronine (Т3), total and free thyroxin (Т4, fТ4), thyroid-stimulating hormone (TSH) of adenohypophysis were determined as well as urinary iodine level was examined. The cognitive functions were characterized by the indices of attention as the result of correction test and rate of sensomotor reactions which were evaluated using modified Schulte tables. It was detected that in all children with latent hypothyroidism regardless of age work accuracy rate decreased, attention span increased slowly, fatigue developed early and rate of information analysis significantly reduced already within the first 5 minutes in comparison with analogical data in healthy children. When being tested children of the control group made fewer mistakes, the tempo of doing tasks remained higher for 5 minutes. There was a correlation between the indices of correction test, sensomotor reactions and data of thyroid status of pupils

Formation of material prescribed phase composition from refractory filler silica powder modified with alkoxide and sol-gel composite

Creation of ceramics and refractories with improved physicomechanical properties is possible with use of nanomaterials in their technology. Introduction of SiC nanoparticles into a ceramic material charge by using modified filler powders is proposed. Fillers modified with tetraethoxysilane during grinding leads to powder crystal structure breakdown and SiC mechanochemical synthesis. The amount of -SiC synthesized in this way depends on the amount of modifying additive. Results are provided for modified filler phase composition before and after heat treatment at 1000°C, and mechanochemically synthesized SiC thermal stability is established. It is shown that sintering of modified electro-corundum worsens with an increase in amount of synthesized silicon carbide nanoparticles. The difference is demonstrated in phase composition formation with heat treatment of a mixture of modified and normal finely ground electrocorundum with a sol-gel binder and firing up to 1600°C. Silicon carbide nanoparticle synthesis does not exceed 3 – 7 % in both cases. Recommendations are given for use of corundum filler with a different amount of modifying additive

Synthesis of β-SiC in the intermediate layer of corundum coatings based on a sol-gel binder for protecting graphite objects from oxidation

A coating is developed for protecting graphite from oxidation at 2023 – 2223 K. The efficiency of the protective action of a corundum coating based on a sol-gel binder increases due to creating a dense intermediate layer between the graphite substrate and the coating as a result of its self-reinforcement with fibers of mullite crystals and -SiC nanoparticles. Components of a modifier and sol-gel binder, but not carbon of the graphite substrate, provide synthesis of β-SiC

Some Structural and Chemical Changes in Endocardial Endothelium of Rats in Emotional and Pain Stress Complicated by Hypercholesterolemia

The objective of the research was to study the content of some neutral lipids of endocardial endothelium in rats in relation to structural changes occurring in it, in the co-existence of emotional and pain stress, as well as alimentary hypercholesterolemia. Materials and methods. The electric-impulse model was used for stress modeling. Alimentary hypercholesterolemia was modeled feeding animals an atherogenic diet. The concentration of triacylglycerols, free and esterified cholesterol were examined using the method of thin-layer chromatography performed on silica gel. The concentration of free fatty acids was determined using the radiochemical method. The state of endocardial endothelium was studied with the help of light microscopy; the impression smears obtained from macro preparations of ventricle were analyzed.Results. In co-existence of stress and hypercholesterolemia, significant increase in free cholesterol as well as free fatty acid concentration was noticed. This essentially exceeded the analogical indices under the action of stress only. Structural changes in the endocardium followed by desquamation of separate endotheliocytes were the result of stress reaction. In the action of both pathogenic factors, this process was intensified; layer-by-layer exfoliation of endotheliocytes was observed. Conclusions. In acute emotional and pain stress, changes in lipid spectrum of membrane structures of endocardial endotheliocytes the main manifestation of which is the accumulation of free cholesterol in cells and increase in the levels of free fatty acids take place. The increase in the number of desquamated endothelial cells is the result of stress action as well. Alimentary hypercholesterolemia significantly increases such pathological changes. 

Problems and prospects of development of ecological tourism in Ireland

The paper presents the research on the development of ecological tourism in Ireland. The basic directions and problems of development of ecotourism. Income from ecotourism in the country was analyzed in the article, as well as the model for the attraction of tourists to Irelan

Features of high-strength composite material structure creation

The basis of technology proposed is use of a sol-gel method for preventing polycrystalline corundum fiber from crystallization during heating to high temperature and for low-temperature synthesis of prescribed phases in a corundum matrix with the aim of improving the operating properties of composite materials based on corundum. As a result of firing a charge based on corundum powder modified with tetraethoxysilane and polycrystalline corundum fiber modified with ethylsilicate-32 at 1360°C materials are created with very good strength properties. The materials exhibit electrical insulation properties and are stable in ionized gas streams at the level of known analogs as a result of creating self-reinforced mullite and β-SiC corundum matrix, reinforced with polycrystalline fiber and rapidly sintered due to presence of silicon oxynitride