Sulfur as a heteroadditive has been incorporated into oxygen-deficient YBa₂Cu₃0_7-x and PrBaCuFeO_5+x perovskites (ODP) using sulfur-ion-conducting solid electrolytes (CaPr₂S₄ and BaSm₂S₄). Composition of ODPs doped by sulfur was monitored by measuring electrical conductivity in combination with EMF method. The mechanism of sulfur incorporation into crystal lattice of nonstoichiometric layered YBa₂Cu₃0_7-x and PrBaCuFeO_5+x ODP has been proposed. Partial molar dissolution values of sulfur trace amounts in PrBaCuFeO_5+x have been calculated.

Sr_1-xLn_xFe_12-xM_x0₁₉ (Ln³⁺ - Sm³⁺, Gd³⁺; M²⁺ - Co²⁺, Zn²⁺) and (Ba_0,5Sr_0,5)_1-xSm_xFe_12-xCo_x0₁₉ (x = 0; 0,1; 0,2; 0,3) ferrites have been prepared by solid-state method in air at 1473 K. It has been shown that isotropic permanent magnets based on Sr_0,9Sm_0,1Fe_11,9Co_0,1О₁₉, (Ba_0,5Sr_0,5)_0,9Sm_0,1Fe_11,9Co_0,1О₁₉ ferrites show higher values of magnetic induction (B_r), coercive force (_BH_c) and maximum energy product (BH)_max than ones based on SrFe_l20₁₉ ferrite. It has been found that using SrFe_9,5Al_2,50₁₉ as an additive increases the coercive force (_BH_c) and maximum energy product (BH)_max for isotropic permanent magnets from the solid solutions of Sr_0,9Sm_0,1Fe_11,9 Co_0,1О₁₉, (Ba_0,5Sr_0,5)_0,9Sm_0,1Fe_11,9Co_0,1О₁₉ ferrites.

For the first time, a method has been developed and calculations have been performed for the mesopore surface of solids containing various volumes of micropores, along with mesopores. It has been shown that the method proposed for determination of mesopores' surface is reliable enough. It has been established that formal application of BET method for specific surface determination of this type of adsorbents is not possible. For surface determination of homogeneous mesoporous adsorbents, a simple and practical method has been proposed excluding several procedures connected with the number of molecules adsorbed and the volume of their adsorption site.

A comparative analysis of n-octane - water functional group increments (I_ƒ) of organic non-electrolytes (hydrocarbons, nitrogen-, oxygen-, halogen- and sulphor-containing compounds containing n-alkyl, allyl, benzyl, vinyl, phenyl, 1-naphthyl, 2-naphthyl and 9-anthryl groups) has been performed. It has been determined that increasing the hydrocarbon chain electronegativity increases I_ƒ by up to 3,7 units. For all monosubstituted groups except fluoride, replacing the alkyl group by the aryl one increases I_ƒ by 0,6-1,2 units. It has been found that the most important factors determining the increase in I_ƒ are the nature and number of hydrocarbon chains, bond polarity in the functional group and its possession of mobile electron pairs.

Distribution of thiencarbazone-methyl and cyprosulfamide between chloroform and aqueous buffer solutions at pH = 3-10 has been studied at 20 ± 1 °С. Based on the experimental data obtained, the extraction sample preparation method has been developed for the determination of thiencarbazone-methyl and cyprosulfamide in corn grain and corn green mass by high performance liquid chromatography. The sample preparation method provides chromatograms where no peak interferes with the peaks of substances being determined. The recoveries of thiencarbazone-methyl and cyprosulfamide from plant matrices are in the range of 72-88%. The method allows determination of thiencarbazone-methyl and cyprosulfamide at concentrations of the maximum residue limit for corn in Republic of Belarus or below.

Photoelectrochemical behavior of semiconductor bismuth oxoiodide BiOI in solutions containing [Fe(CN)₆]^3-/[Fe(CN)₆]^4-or I₃^-/I^- redox system has been studied. The effect of photocurrent sign inversion with the electrode potential change has been observed. It has been shown that this effect is governed by both thermodynamic conditions (shifting of the conduction band position and equilibrium potential E_Ox/Red) and by kinetic factor (the capture rate of photogenerated charged particles by oxidizing or reducing agents). Photoelectrochemical reactions are diffusion-controlled, and photocurrent is a function of the surface concentrations of oxidized and reduced forms of the redox system. Specific structure of BiOI coating consisting of thin plate-like crystallites (40-60 nm thick) provides good contact of its surface with the reaction medium and high efficiency of photoinduced processes.

α-Pinene catalytic isomerization over natural aluminosilicate (Al-Si RB) modified by hydrochloric and phosphoric acid solutions has been studied. The effect of Al-Si RB acid treatment on its composition, structure and catalytic activity has been investigated. The highest α-pinene conversion and yield of target products (camphene, dipentene) has been observed in presence of aluminosilicate treated by 50 ml/g of 10% HCl. Operation time of the catalyst has been determined. Possibility of waste acid solution recycling has been shown.

Using polyvinylpyrrolidone (PVP) as a polymer matrix for potassium 4,4-bis[1-(4-hydroxybutyl-3-carboxylate)phenylazo] biphenyl (ABA-2422) promotes trans-cis-isomerization and orientation of dye molecules on irradiation by linearly polarized light. Composite films based on ABA-2422 dispersed in PVP are optically anisotropic, have high dichroic ratio and low roughness.

New 1,2-diacyl-1-alkylhydrazines containing fragments of halogenated benzoic acids and 3,5-dimethylbenzoic acid have been synthesized. These compounds are close structural analogues of known ecdysteroid agonists, methoxyfenozide and halofenozide, used in agriculture as hormonal biorational insecticides. Primary screening of new organic compounds for insecticidal activity has been performed. It has been discovered that two of the synthesized compounds are more toxic for Colorado potato beetle than methoxyfenozide.

Synthesis of (£)-azomethines, derivatives of 4-aminobenzenesulfonamide (Streptocidum), by condensation of substituted vanillin-like benzaldehydes with streptocidum in methanol, has been described.

A series of fluorinated benzaldehyde oxime esters and pyrazinecarboxylic acid esters has been synthesized. Target compounds have been prepared by esterification of oximes with pyrazinecarboxylic acid in the presence of N, N'-dicyclohexylcarbodiimide and N, N-dimethylaminopyridine. Antimycobacterial properties of the synthesized compounds have been studied.

Human cytochrome CYP21 (steroid 21-hydroxylase) has been expressed in Escherichia coli DH5α and the expression level was 150 nmol from 1 liter of bacterial culture. Utilizing two steps of column chromatography has allowed to obtain highly purified protein. Steroids have been screened as potential substrates for the enzyme. CYP21 showed typical spectral change (type I of spectral responce) when binding with progesterone, 17α-hydroxyprogesterone and 11-hydroxyprogesterone. In addition, it has been shown that cytochrome b₅ does not affect hydroxylase activity of CYP21 toward progesterone, 17a-hydroxyprogesterone and 11-hydroxyprogesterone.

Accurate and reproducible techniques for determining key polymorphism of drug metabolizing CYP450 and MDR1 genes have been designed. Based on those techniques, pharmacogenetic test as well as genetic data interpretation algorithm has been developed, which allows to personalize and improve the effectiveness of psychopharmacotherapy.

The effect of N(phosphonomethyl)-glycine (glyphosate), the active ingredient of the «Squall» herbicide in a wide range of concentrations (1-1000 |ig/ml) on phospholipolysis catalyzed by pancreatic phospholipase A₂ (PLA₂, 3.1.1.4), under the conditions similar to digestion in the duodenum (pH 8.0, temperature S, micellar form PC), has been studied. It has been shown that a rapid method based on the use of in vitro phospholipolytic reaction as a simple model of the process of destruction of food and phospholipids of cell membranes, is promising for preliminary evaluation of the pesticide safety to humans and animals.

Studies on the development of efficient collectors for clay-carbonate impurities during the flotation enrichment of potassium ores have been conducted. It has been shown that using slime collectors in the form of emulsions based on carboxylic acids ensures their high stability in saturated salt solutions and intensifies flotation of slimes and subsequent flotation of potassium chloride.

To produce the paper of high printing qua1ity, paper pu1p fi11ers are common1y used. A carbonate fi11er derived from marb1e (marb1e ca1cite), has 1ow content of impurities (1°%) and high whiteness (up to 97%), making it a promising one for specia1 types of printing paper. To achieve a high degree of fi11er retention in the composition and ensure its most uniform and high content in the top and bottom (grid) paper 1ayers, the fi11er has been modified by cationic starch. Modification of marb1e ca1cite with cationic starch provided directed concentration of the fi11er in both surface 1ayers of paper. It has been proved that by increasing the proportion of cotton ce11u1ose in the paper, the distribution pattern of the modified fi11er changes, increasing its concentration in the surface 1ayers, making it possib1e to obtain high quality printing on the paper with improved durabi1ity.

The results for synthesis of light-diffusing gkasses based on phosphate suppressor in the ZnO-P₂O₅-SiO₂ system doped by CaO, Na₂O, K₂O и B₂O₃ (25% w/w total). Light-diffusing glasses with high transparency. The main light-diffusing phase are liquate drops 0,15-0,2 μm in diameter, enriched with K₂O, ZnO and P₂O₅, producing KZnP₂O₅ crystals.

The geochemical condition of soils in Pripyat' Polesye, Brest region, has been studied. The main sources of soil pollution by chemicals have been determined and maps for their distribution have been drawn. Areas of soils polluted by nitrates, sulphates, chlorides and heavy metals have been calculated.