The analysis of biological diversity of coronaviruses contributes in the early awareness of their zoonotic spreading

The recent outbreak of COVID-19 rose a new wave of interest to coronaviruses though the first coronaviruses were discovered in the first half of the 20th century. That time coronaviruses were considered as a quite serious veterinary problem but they were not believed to become highly dangerous for humans. However, such ideas were revised in 2002 when SARS-CoV was transferred to human population in the Southeast Asia assumably from the bats, and later in 2012 when natural focus of the MERS-CoV was discovered in the Arabian countries. Using PubMed, EMBASE, Scopus, and Google scholar, the authors searched for various research and review articles using the combination of terms “coronavirus, Coronaviridae, SARS-CoV, MERS-CoV, SARS-CoV-2, COVID-19, taxonomy”. Due to the increased interest a large number of new Coronaviridae family members was revealed in the first decades of the XXI century. Since then taxonomic structures of coronaviruses underwent significant changes. This review is focused on the need for continued monitoring of the biological diversity of coronaviruses. The structural studies of coronaviruses regardless of the host species may allow us to identify early changes that can affect the evolutionary drift process of a particular HCoV species involved in viral transmission from bats or birds to humans. Taking into account the migratory abilities of bats and especially birds, it is necessary to not only to include coronaviruses in the ecological monitoring programs, but also to expand the scope and depth of environmental and virological monitoring

Energy Power Parameter Effect of Hot Rolling on the Formation of the Structure and Properties of Low-alloy Steels

The temperature and degree of hot deformation for steel 10HFTBch have been determined. This made it possible to ensure an increase in the mechanical properties of this steel, namely, the ultimate strength up to 540–560 MPa, as well as the relative elongation up to 25–29 %. As a result, it became possible to increase the service life of wheels with increased carrying capacity. This, in turn, will make it possible to increase the load of the transported cargo by motor vehicles several times. The mechanism of the influence of the energy-power parameters of rolling on the formation of the macro- and microstructure of a two-phase steel in the process of hot deformation is disclosed. The applied scheme provided an increase in the homogeneity of the structure of the developed steel, which saved the central part of the rolled section from overheating. It has been established that a decrease in the temperature of the end of deformation leads to a decrease in the size of the recrystallized austenite grain, and, consequently, to a refinement of the ferrite grain. Also an important factor in preventing the growth of ferrite grains in the upper part of the ferritic region is the abolition of cooling of the steel in coils. The recommended mode for multicomponent alloy steel 10HFTBch is as follows: the temperature of the end of rolling is 850 °C, the beginning of accelerated cooling is 750 °C, and the temperature of strip coiling into a coil is 600 °C. The basis for ensuring the increased strength of two-phase steels is the ratio and distribution of structural fractions – ferrite (initial and precipitated from austenite), as well as martensite. When hardened by such traditional "martensite formations" as manganese, the ability to control properties is limited. This is reflected in a narrow range of variation in the strength and ductility of the developed steel. The optimal combination of strength characteristics of plastic properties reduces the metal consumption of the product by 15–25 %