Silver(I) triflate-catalyzed protocol for the post-ugi synthesis of spiroindolines

A silver(I) triflate-catalyzed protocol for the post-Ugi synthesis of tetracyclic spiroindolines has been developed. The protocol worked best for indole-3-carbaldehyde-derived Ugi adducts obtained using anilines and 3-aryl propiolic acids. Thus, it is complementary to the previous cationic gold-catalyzed procedure that was developed for analogues Ugi substrates derived from aliphatic amines and 3-alkyl propiolic acids. Furthermore, we have demonstrated that under our new settings this domino Friedel-Crafts ipso cyclization / imine trapping process could be efficiently combined with the preceding four-component Ugi reaction into a two-step one-pot transformation

U(1)-Symmetry breaking and violation of axial symmetry in TlCuCl3 and other insulating spin systems

We describe the Bose-Einstein condensate of magnetic bosonic quasiparticles in insulating spin systems using a phenomenological standard functional method for T = 0. We show that results that are already known from advanced computational techniques immediately follow. The inclusion of a perturbative anisotropy term that violates the axial symmetry allows us to remarkably well explain a number of experimental features of the dimerized spin-1/2 system TlCuCl3. Based on an energetic argument we predict a general intrinsic instability of an axially symmetric magnetic condensate towards a violation of this symmetry, which leads to the spontaneous formation of an anisotropy gap in the energy spectrum above the critical field. We, therefore, expect that a true Goldstone mode in insulating spin systems, i.e., a strictly linear energy-dispersion relation down to arbitrarily small excitations energies, cannot be observed in any real material.Comment: 6 pages, 3 figure

Experimentally measuring rolling and sliding in three-dimensional dense granular packings

We experimentally measure a three-dimensional (3D) granular system's reversibility under cyclic compression. We image the grains using a refractive-index-matched fluid, then analyze the images using the artificial intelligence of variational autoencoders. These techniques allow us to track all the grains' translations and 3D rotations with accuracy sufficient to infer sliding and rolling displacements. Our observations reveal unique roles played by 3D rotational motions in granular flows. We find that rotations and contact-point motion dominate the dynamics in the bulk, far from the perturbation's source. Furthermore, we determine that 3D rotations are irreversible under cyclic compression. Consequently, contact-point sliding, which is dissipative, accumulates throughout the cycle. Using numerical simulations whose accuracy our experiment supports, we discover that much of the dissipation occurs in the bulk, where grains rotate more than they translate. Our observations suggest that the analysis of 3D rotations is needed for understanding granular materials' unique and powerful ability to absorb and dissipate energy

Housing Construction on Territory of Baikal-Amur Mainline Building-up in 1970s—1980s (Khabarovsk Region)

The history of the construction of BAM settlements on the territory of the Khabarovsk region in 1974—1984 is considered. The relevance of the study is due to the need to study the experience of housing construction of the Soviet era in areas of new development, the use of which is possible for the development of modern programs of the Far East. Using materials from the funds of the State Archives of the Khabarovsk region, the authors analyzed the volumes of construction of housing and social infrastructure facilities, identified the main shortcomings and difficulties associated with this process, such as lagging behind the construction of housing, adjusting master plans. An attempt has been made to classify the BAM settlements of the Khabarovsk region, to determine the set of social infrastructure facilities in them. The novelty of the research is determined by the poor study of the history of BAM construction settlements on the territory of the Khabarovsk region and the introduction of new sources into scientific circulation. The authors come to the conclusion that the lack of housing and the poor development of social infrastructure in the BAM villages of the Khabarovsk region became one of the reasons for the outflow of BAM builders, which negatively affected the implementation of the government’s plans to settle the Far East and ensure the effective use of the Baikal-Amur Mainline

NEW APPROACH TO THE TREATMENT OF VALVULAR INFECTIOUS ENDOCARDITIS

An. original method of intracardiac sanation of infection nidus with use of the preparation of bacterial proteinases immobilized on polymeric matrix was offered and proved on the resulta of surgical treatment of 226 patients with infectious endocarditis. The results of treatment were analysed and. the effectiveness of the method was proved