Search

Quercetin is one of the most promising natural polyphenolic radioprotective compounds. This property is based on its radical-scavenging activity and high antioxidant capacity, in the manifestation of which the products of oxidative degradation of quercetin play a significant role. The formation of specific metabolites during the oxidation of quercetin can determine not only its radioprotective properties, but also toxic manifestations. The purpose of this article is to summarize previously obtained data regarding the reaction pathways of oxidative transformation of quercetin. Materials and methods. We used publicly available scientific publications dedicated to the study of quercetin transformation processes. The method of analysis is descriptive. The discussion of the results. A review of scientific works dedicated to oxygen oxidation, radical-initiated oxidation, electrochemical and enzymatic oxidation is presented, possible transformation products of quercetin and the mechanisms of their formation are given. The most characteristic oxidation pathways of quercetin are determined by the chemical structure of the rings, which exhibit specific reactivity. The influence of the solvent composition on the oxidation products during the autoxidation of quercetin was revealed, while the radical and electrochemical models of oxidation differ in the presence of polymer adducts. Once in a living organism, quercetin can bind free radicals, thereby preventing the harmful effects of radiation, that is, it has the properties of a radioprotector. Conclusions. Quercetin can be considered as a potential radioprotector due to its ability to bind free radicals formed in the biological fluids of living organisms exposed to radiation.

It is necessary to develop special assessment tools for international students, which will comply with the principles of evidence-based education. This is especially important in the context of Russian higher education export. Multiple choice questions (MCQs) are an essential part of the assessment and are suited for assessing the knowledge level of international students. The “Organic chemistry” is a basic course for pharmaceutical students, which is necessary for the understanding of principal subjects. The study objective was to develop a normative-oriented model of the “Organic chemistry” MCQs based examination for international students (the specialty 33.05.01 “Pharmacy”) in accordance with the recommendations of the Association for Medical Education in Europe (AMEE). The previously developed interactive “Organic Chemistry Test Simulator”, created at the Sechenov University, was used as the basis for the examination MSQs bank. It was analyzed by five independent experts, who work as teachers of organic chemistry. The average timing and the cut score were determined by the Angoff method, 90 sec and 64%, respectively. Among analyzed MCQs the 3% were found irrelevant, 22% were recommended for revision and modernization. Valid MSCs (600 items) served as the basis for the creation of extended examination MSQs bank. An algorithm for modeling the “Organic chemistry” MCQs based examination was proposed. The standardized examination test has 30 MSQs of different types. The standardized normative-oriented model of the “Organic chemistry” MCQs based examination for international students (the specialty 33.05.01 “Pharmacy”) was validated in terms of relevance and representativeness, optimized in time and cut score.

Crop productivity is significantly affected by the dose of optical radiation. In particular, southern crops do not have enough time to ripen in a temperate climate because of decreased daylight duration. In conditions of protected soil due to low irradiance and a short daylight duration in autumn­-winter months, the cultivation of fully developed plants is possible only with the use of artificial radiation sources. The use of LED phytoinstallations with the help of microprocessor­based automatic control systems allows obtaining the required dose of optical radiation. (Purpose of research) To substantiate, as exemplified by meristematic grape plants, the effectiveness of LED phytoinstallations and their impact on the increase in the leaf surface area; to develop multi­colored LED phytoinstallations; to offer new technical solutions to improve the efficiency of the microprocessor system of automatic control of LED phytoinstallations. (Materials and methods) the authors have carried out experiments with meristematic grape plants of RF­48 variety (in vitro) at the stages of their rooting and adaptation. The following equipment has been used: LED phytoirradiator with a changing spectrum using a microprocessor control system, “blinking” led phytoirradiator, multi­colored phytoiradiator with the addition of UV LEDs. The authors have developed on the basis of microcontroller Arduino uno a microprocessor dispensing system of the spectral components of the areas of the photosynthetically active radiation to automatically control the operation of LED­based phytoinstallations. (Results and discussion) it has been shown that a LED irradiator with a changing spectral composition, as compared to a luminescent irradiator, at the stage of rooting of grape microsprouts contributes to a significant increase in the leaf surface area of microplants at 100 percent rooting of sprouts. The blinking phytoirradiator and the UV­LED phytoirradiator, as compared to the fluorescent ones, contributed to an insignificant increase in leaf area of plants at the adaptation stage of grape microplants. (Conclusions) The authors have confirmed the need to further improve the efficiency of the microprocessor­based automatic control system of LED irradiation installations.