ASSESSMENT OF ANTITOXIC AND ANTI-INFECTIOUS ACTIONS OF THE EXPERIMENTAL PREPARATION

In the course of the research, the antitoxic and anti-infectious effects of the developed drug were determined on white mice and white rats. To assess the antitoxic effect in the experiment on white rats, cadmium damage was modeled, followed by taking into account the antidote activity. An increase in the survival rate of animals receiving the drug was found – 60 % versus 40 % in the control, higher hematological indicators: the content of hemoglobin, erythrocytes and leukocytes in the blood of experimental animals was higher than similar control values, respectively, by 3.8, 15.3 and 16,4 %. The anti-infectious effect of the feed additive was determined during the experiment on infecting white mice with the causative agent of Escherichiosis – E. coli (strain "KB-1"). It was found that the introduction of the study drug into the diet of infected animals smoothed the clinical picture of the infectious process, had a hemoprotective effect: the content of erythrocytes, leukocytes, neutrophils, lymphocytes, neutrophils in the blood of experimental animals exceeded the control values, respectively, by 2.5, 13.6, 16, 7, 14.3, 28.6 %. The results of the investigated subject showed that the investigational drug has a well-pronounced antitoxic and anti-infectious effect.

ASSESSMENT OF RADIO PROTECTIVE AND ADAPTGENIC ACTIONS OF THE EXPERIMENTAL PREPARATION

In the course of the research, the radioprotective and adaptogenic effects of the new feed additive were determined in experiments on white mice and white rats. It was found that the inclusion of the studied feed additive in the diet of mice after irradiation provided an increase in the survival rate of animals irradiated with a lethal dose by 50% compared to the control. Feeding the mice with the drug followed by irradiation with a lethal dose increased the survival rate by 42 %. In a similar experiment on white rats, the survival rate of the experimental animals was higher than the control values by 58 and 50 %, respectively. When assessing the adaptogenic effect of the drug, it was found that 12-hour immobilization of rats led to significant changes in the prooxidant-antioxidant defense system. Preliminary feeding of the studied feed additive had a protective effect, which was manifested in a lower content of malondialdehyde in the blood serum of experimental animals, compared with control animals, by 28.0 %, an increased content of catalase by 11.1 %, superoxide dismutase by 43.9 %, reduced glutathione - by 17.6 %. Thus, the investigated drug showed a well-pronounced radioprotective and adaptogenic effect.

Numerical Models of the Connection of Thin-Walled Z-Profile Roof Purlins

High thin-walled purlins of Z cross-section are important elements in steel wide-span structures. Their behaviour is influenced by many variables that need to be examined for every specific case. Their practical design thus requires extended knowledge of their behaviour for the possible configurations and dimensions. Numerical analysis verified by experimental investigation can thus enrich such knowledge. Numerical models have the advantage of repeatability and the ability to offer parametric changes. The parametric study presented shows a detailed description of a finite element model of thin-walled cross-sectional roof purlins connected to other roof elements. Models include various approaches to modelling bolt connection. Two schemes of purlins, with and without cleats, are presented. The results of different approaches in numerical modelling are compared with the results of a physical test on a real structure. The article shows a significant agreement in the case of specific approaches and points out the differences with others. The results can be helpful in terms of how to approach the modelling of thin-walled structures and the effective approach to experimental preparation.

Assessment of the Potential Ability to Penetrate into the Hard Tissues of the Root of an Experimental Preparation with the Characteristics of a Dental Infiltrate, Enriched with an Antimicrobial Component—Preliminary Study

Infiltration is a method of penetration with a low viscosity resin that penetrates deep into demineralised tooth tissue and fills the intergranular spaces, hence reducing porosity. Carious lesions initially located at the enamel–cement junction are usually found in elderly patients. Those spots are predisposed to bacterial adhesion originating both from biofilm and from gingival pocket bacteria. The aim of this study was to evaluate the penetration of an experimental preparation, which has the characteristics of a dental infiltrant, enriched with an antibacterial component, into the decalcified root cement tissues of extracted human teeth in elderly patients. An experimental preparation with the characteristics of a dental infiltrant was prepared, applied, and polymerised on the surface of extracted, previously decalcified human teeth. The control sample was Icon (DMG, Hamburg, Germany). The ability of the preparations to penetrate deep into the root cement was evaluated using scanning electron and light microscopy. The study showed that an experimental preparation could potentially be used for treatment of early carious lesions within the tooth root in elderly patients, among others, as it penetrates deep into demineralised tissues. More research is needed.

Biological control agents of the number of Halyomorpha halys Stål

Research aimed at studying the control of the number of pests of many agricultural crops – Halyomorpha halys Stål, was carried out during 2018-2020 on the territory of the Central zone of Krasnodar Krai. In the experiments, there were used individuals of a brown marmorated stink bug, caught by hand and using a pheromone trap at different stations (tree and shrub vegetation, soybean crops). In 2020, the dynamics of the abundance of the brown marmorated stink bug was monitored since the end of May (the time of the appearance of the first individuals of H. halys) to the third decade of October. Among the natural entomophages in Krasnodar Krai, two species of parasitic insects were found: Pediobius cassidae Erdos. (Hymenoptera: Eulophidae) and Anastatus bifasciatus Geoffroy (Hymenoptera: Eupelmidae), infecting about 5-10 % of H. halys eggs in the field, which did not significantly affect the abundance of the brown marmorated stink bug. In the laboratory, essential oils from several botanical families were tested: Umbelliferae, Compositae, Abies. Essential oils of wormwood, coriander and Siberian fir showed a toxic effect against the brown marmorated stink bug; the death of adults on the tenth day was 100, 95.0 and 93.7 %, respectively. Also, on the soybean crops of the Arleta variety, field tests were carried out to study the efficacy of bio-rational preparations Biostop, P and an experimental preparation developed at the Federal State Budgetary Scientific Institution "Federal Research Center of Biological Plant Protection" (FSBSI FRCBPP). The experimental preparation of FRCBPP caused the death of 64.2 % of individuals of H. halys, Biostop, P – 70.1 %.

From basic properties to the Mott design of correlated delafossites

The natural-heterostructure concept realized in delafossites highlights these layered oxides. While metallic, band- or Mott-insulating character may be associated with individual layers, inter-layer coupling still plays a decisive role. We review the correlated electronic structure of PdCoO2, PdCrO2, and AgCrO2, showing that layer-entangled electronic states can deviate from standard classifications of interacting systems. This finding opens up possibilities for materials design in a subtle Mott-critical regime. Manipulated Hidden-Mott physics, correlation-induced semimetallicity, or Dirac/flat-band dispersions in a Mott background are emerging features. Together with achievements in the experimental preparation, this inaugurates an exciting research field in the arena of correlated materials.

Study of Cytotoxic Properties of an Experimental Preparation with Features of a Dental Infiltrant

Microinvasive dentistry is based on the treatment of early carious lesions with the use of dental infiltrants. The commercially available Icon dental infiltrant does not contain any bacteriostatic component. An experimental preparation enriched with the missing component was synthesised. The aim of this study was to evaluate the cytotoxicity of the experimental preparation. Mouse fibroblasts of the L-929 lineage were used for the in vitro study. Cell morphology and viability were assessed. In the cytotoxicity analysis, it was shown that the experimental preparation (42.8 ± 10.3) after 24 h at two-fold dilution showed similar cytotoxicity to Icon (42.7 ± 8.8) (p > 0.05), while at four-fold dilution experimental preparation (46.7 ± 3.1), it was less toxic than Icon (34.2 ± 3.1) (p < 0.05). The experimental preparation has the potential to provide an alternative to the Icon commercial preparation. Further research is needed to evaluate the cytotoxicity of the experimental preparation over a longer period of time.

INVESTIGATION OF DIAZINON DEGRADATION IN MODEL SOLUTIONS USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Aim of our war was to investigate the degradation of diazinon in the model mixture in comparison with the experimental preparation. Methyl alcohol was used as a basis for the manufacture of diazinon drops and the model mixture. The concentration of diazinon was determined by reversed-phase high performance liquid chromatography on the third, fourteenth and twenty-first day after preparation of the model mixture and experimental preparation when stored at room temperature. Despite the large number of publications studying the degradation of diazinon under the influence of various factors, there is a need to study this process in mixtures of a specific composition, in particular in new veterinary drugs that have not yet been studied. This article presents the results of determining the content of diazinon in 10% of the drug and the model mixture based on methyl alcohol. The analyzes were performed on a Knauer liquid chromatograph with a spectrophotometric detector equipped with a Luna® Omega Polar C 18 150 × 4.6 mm column filled with a 5 μm particle sorbent from Phenomenex with a universal C 18 pre-column 4 × 3.0 mm ID. Mobile phase: degassed mixture of acetonitrile: water in the ratio 65:35, flow rate was 1.1 ml/min, temperature of the column was ambient. Diazinone was detected at 245 nm. Injection volume was 0.050 ml and the time of one separation – 20 minutes. The appearance of an unknown peak on the 3 min chromatogram of the solution of the production experimental preparation was revealed. On the twenty-first day of storage of the experimental drug, the content of diazinon decreased to 34 % of the stated amount. On the third and twenty-first day of storage of the model mixture, a decrease in the content of diazinon by 16 % and 79%, respectively, and the appearance of an additional peak were observed. The use of methyl alcohol with other components is likely to be a factor in the breakdown of diazinon in the drug. According to the recipe of the drug, methanol is about half the content of ingredients. This composition does not provide stability of the proposed dosage form of the drug. The next step will be to study the effect of other solvents on maintaining the stated concentration of diazinon.