Iridium-Catalyzed Silylation of Five-Membered Heteroarenes: High Sterically Derived Selectivity from a Pyridyl-Imidazoline Ligand.

The steric effects of substituents on five-membered rings are less pronounced than those on six-membered rings because of the difference in bond angles. Thus, the regioselectivities of reactions of five-membered heteroarenes that occur with selectivities dictated by steric effects, such as the borylation of C-H bonds, have been poor in many cases. We report that the silylation of five-membered-ring heteroarenes occurs with high sterically derived regioselectivity when catalyzed by the combination of [Ir(cod)(OMe)]2 (cod=1,5-cyclooctadiene) and a phenanthroline ligand or a new pyridyl-imidazoline ligand that further increases the regioselectivity. The silylation reactions with these catalysts produce high yields of heteroarylsilanes from functionalization at the most sterically accessible C-H bonds of these rings under conditions that the borylation of C-H bonds with previously reported catalysts formed mixtures of products or products that are unstable. The heteroarylsilane products undergo cross-coupling reactions and substitution reactions with ipso selectivity to generate heteroarenes that bear halogen, aryl, and perfluoroalkyl substituents

Hydrazides in the Processes of Extraction of Non-ferrous Metals from Ammonia Solutions

The extraction of copper and other non-ferrous metals from ammonia solutions with hydrazides оf Versatic acids (C15–C19 fraction) is discussed in this article. Hydrazide group has been known to be a selective extractant for non-ferrous metals. Introducing the alkyl radical of -branched tert-carboxylic acids into the reagent structure may lead to new properties important for an extractant, such as chemical stability and good compatibility with solvents properties. The optimal extraction conditions, the effect of ammonium salts and the regularities of re-extraction are assessed. Keywords: extraction, hydrazides,  -branched tert-carboxylic acids, non-ferrous metal

Biosynthesis of secreted ribonucleases of Bacillus intermedius and Bacillus circulans under nitrogen starvation

The level of biosynthesis of secreted guanyl-specific ribonucleases (RNases) of Bacillus intermedius (binases) and Bacillus circulans (RNases Bci) by recombinant B. subtilis strains increases under nitrogen starvation. The promoter of the binase gene carries the sequences homologous to the recognition sites of the regulatory protein TnrA, which regulates gene expression under growth limitation by nitrogen. Using the B. subtilis strain defective in protein TnrA, it has been shown that the regulatory protein TnrA is involved in the regulation of expression of the binase gene and the gene of RNase Bci. The TnrA regulation of expression of the RNase Bci gene is indirect, probably by means of the regulatory protein PucR. Thus, it has been established that at least two regulatory mechanisms activate the expression of the genes encoding the secreted RNases of spore-forming bacteria: a system of proteins homologous to the B. subtilis PhoP-PhoR, and regulation by a protein similar to the B. subtilis TnrA regulatory protein. © 2009 Pleiades Publishing, Ltd

A flaring X-ray pulsar in Dorado

A study of unusual gamma-ray bursts detected on March 5 and March 6, 1979 in the KONUS experiment on the Venera 11 and Venera 12 spacecraft shows their source to be flaring X-ray pulsar in Dorado

Preliminary results of a gamma-ray burst study in the Konus experiment on the Venera-11 and Venera-12 space probes

Twenty-one gamma-ray bursts and 68 solar flares in the hard X-ray range were detected on Venera-11 and Venera-12 space probes during the initial 50-day observation period. Major characteristics of the equipment used and preliminary data on the temporal structure and energy spectra of the gamma-ray bursts are considered. The pattern of gamma-ray burst frequency distribution vs. intensity, N(S), is established

Dynamics of Media Preferences of Children's Audience at the Present Stage

В статье рассматривается динамика изменений в информационном поведении детской аудитории на современном этапе. Выявляются особенности и тенденции медиапредпочтений детей цифрового поколения. Автор анализирует влияние цифровизации белорусской медиасферы на медиаповедение детской аудитории. Определены особенности распространения цифровых медиа для подрастающего поколения. Делается прогноз развития отечественной детской медиасферы и формирования нового поколения медиапотребителя.The author identifies the dynamics of changes in the information behavior of children’s audience at the present stage. He identifies the characteristics and tendencies of media preferences of children of the digital generation. The author analyzes the influence of the Belarusian media sphere digitalization on the media behavior of children’s audience. The peculiarities of digital media distribution for the younger generation are determined. The forecast of development of domestic children’s media sphere and formation of a new generation of media consumer is made

Dynamics of changes in B1 and B2 lymphocyte populations in articular form of seronegative rheumatoid arthritis

Immunopathogenesis of rheumatoid arthritis (RA) is characterized by polyclonal activation of B lymphocytes, changes in their subpopulation composition, impaired peripheral tolerance, increased activation and differentiation of B cells, as well as deficient negative selection. Peripheral blood phenotypes of B1 and B2 lymphocytes, their correlation and response patterns in seronegative variant of articular RA type A decrease in B1 lymphocytes along with increased degree of clinical activity and duration of RA has been revealed. B2 lymphocytes remained the predominant subpopulation in peripheral blood. The studied parameters of B2 lymphocytes in the patients with disease duration of up to 5 years and more were higher than the data obtained in a control group. However, no significant changes in their dynamics were revealed upon comparative analysis. With increasing degree of clinical activity, the decreased activation potential of B2 lymphocytes was revealed, along with reduction of costimulatory signal transmission via the CD40/CD40L complex. Hence, detection of B1 and B2 lymphocytes in various types of RA may be used as diagnostic and prognostic markers

Verbal Markers of Regional Identity in Ergonimicon of Ekaterinburg

В работе анализируется специфическая группа эргонимов Екатеринбурга, содержащих региональный компонент. Выявляются ключевые образы, заложенные в основу номинаций городских предприятий.The report analyzes a specific group of Ekaterinburg ergonyms, which contain a regional component in their semantics. There are identified key images that urban enterprises’ nominations are based upon

Idiomatic equivalents in terms of metaphoric transfer

The article presents a hermeneutic approach to idiomatic equivalents in terms of metaphoric transfer. Metaphor is viewed by the authors in its broad sense that can be applied to any use of words in an indirect meaning. Hence, an idiom is understood as a verbalized metaphor that reflects both the universal and specific features of a given language. Idiomatic equivalence that traditionally refers to the linguistic properties of the idiom is presented in the article as hermeneutic equivalence based on the thinking activity approach. Within the framework of such approach the idiomatic equivalence highlights the transfer from one culture to another way of thinking and thinking activity organization