Introduction. Currently, magnetic nanoparticles of iron oxides are widely used in many branches of human activity. Among the production technologies, the most dangerous are metallurgical production, electric arc and gas welding, metal smelting and cutting at steel mills, during which metal oxide nanoparticles are formed in significant quantities. Materials and methods. Male white rats were orally introduced for 10 days with an aqueous solution of Fe3O4AG (iron oxide nanoparticles stabilized with the polymer arabinogalactan) at doses of 500 µg/kg. After the end of the exposure, the animals were decapitated under light ether anesthesia. Blood, brain, liver, and kidneys were taken for biochemical, histological, and genotoxic analysis using the DNA comet method. Results. Studies have shown a decrease in the amount of hemoglobin per unit of blood, a decrease in the total number of neurons in brain tissue, an increase in the area of the renal glomeruli chamber and an increase in DNA damage in nucleated blood cells. Limitations. The experiment is limited to the study of biochemical parameters of peripheral blood, histological analysis of brain, liver and kidney tissue, as well as the study of the effect of iron oxide nanocomposite at doses of 500 µg/kg on male white rats the next day after a ten-day exposure. Conclusion. The biological effect of iron oxide nanocomposite is characterized by a decrease in the amount of hemoglobin, DNA fragmentation in nucleated blood cells, an expansion of the chamber area of the renal glomeruli of the renal cortex, and a decrease in the total number of neurons in the sensorimotor cortex.
The article is devoted to the analysis of a key rhetorical tool used in scientific communication for critical reflection and rejection of controversial or erroneous statements. The research focuses on the strategy of counterargument, considered as a systematic way of organizing scientific communication aimed at achieving a specific communicative goal — convincing refutation. The paper provides a detailed linguistic and rhetorical analysis of the structure of the counterargument, revealing its main components: the identification and precise formulation of the contested thesis, providing strong evidence of its inconsistency and putting forward an alternative position. Special attention is paid to the typology of counterarguments used in scientific texts, such as criticism of methodology, pointing out logical contradictions, appealing to contradictory data, or demonstrating the irrelevance of an opponent's arguments. The authors conclude that effective counterargument in the scientific community is not limited to simple denial, but is a constructive process aimed at strengthening scientific credibility and promoting knowledge. The study demonstrates how mastery of this strategy contributes not only to winning intellectual discussion, but also to maintaining ethical standards of scientific communication. The article will be useful to linguists, experts in argumentation theory, scientists, as well as all researchers seeking to improve the effectiveness of their communication in the academic environment.
AbstractReview: ethynylation and cyclization of aldehydes and ketones as well as C‐, N‐, and O‐vinylation with acetylene in superbasic media; 369 refs.
The main advances in the chemistry of acetylene in superbasic media achieved over the last five years are analyzed. Particular emphasis is placed on the ethynylation of aldehydes and ketones and C-, N- and O-vinylation. The cascade assembly of complex molecules in which ethynylation and vinylation are consecutive steps is considered. The bibliography includes 369 references.
AbstractThiaselenanes (II) are formed regioselectively as a result of anti‐Markovnikov addition of selenium dihalide at the allyl group.
