The RNA helicase ​Aquarius exhibits structural adaptations mediating its recruitment to spliceosomes.

Aquarius is a multifunctional putative RNA helicase that binds precursor-mRNA introns at a defined position. Here we report the crystal structure of human Aquarius, revealing a central RNA helicase core and several unique accessory domains, including an ARM-repeat domain. We show that Aquarius is integrated into spliceosomes as part of a pentameric intron-binding complex (IBC) that, together with the ARM domain, cross-links to U2 snRNP proteins within activated spliceosomes; this suggests that the latter aid in positioning Aquarius on the intron. Aquarius's ARM domain is essential for IBC formation, thus indicating that it has a key protein-protein-scaffolding role. Finally, we provide evidence that Aquarius is required for efficient precursor-mRNA splicing in vitro. Our findings highlight the remarkable structural adaptations of a helicase to achieve position-specific recruitment to a ribonucleoprotein complex and reveal a new building block of the human spliceosome

Performance evaluation of foamed materials based on cold-cured liquid glass

ABSTRACT: Introduction. The current trend of transition to non-combustible and environmentally friendly thermal insulation and sound-absorbing materials involves development of research to obtain foamed silicate compositions, particularly those based on cold-cured liquid glass. The primary advantage of this material is its eco-friendliness throughout both its operational and production stages, facilitated by the employment of energy-efficient manufacturing technology. Materials and methods. Cold-cured liquid sodium glass and cullet-based foam glass were used as main raw materials. To determine optimal curing additive of liquid glass, Portland cement, slaked lime and sodium ethylsilicate were selected. The thermal conductivity of materials was evaluated with by means of appropriate coefficient, value of which depended on volume content of pores in material, nature of porosity and distribution of pores by size. The decrease in water absorption capacity was estimated by value of wetting edge angle. Sorption humidity was determined in accordance with GOST 24816-2014, and sound absorption coefficient was determined according to GOST 16297-80. Results and discussion. The prime objective of this study was to examine trends and provide explanations for the formation of specified performance indicators of thermal insulation and sound-absorbing materials, particularly those based on cold-cured foamed liquid glass. The issue of increasing water resistance of material by selecting effective additive-hardener was also investigated. Conclusion. The developed thermal insulation material based on cold-cured liquid glass is eco-friendly, with presence of large number of small and mainly open pores, giving it good sound-absorbing properties. The problem of high-water absorption of material was solved by introducing Portland cement as a curing additiv

Сорбенты для экстракорпорального удаления токсических веществ и молекул с нежелательной биологической активностью (обзор)

The review devoted to sorbents and sorbentbased medical devices used in clinical practice for extracorporeal detoxification using a hemoperfusion technique. Clinical data have confirmed the effectiveness of this approach for removal of bacterial endotoxins, lowdensity lipoproteins, and bilirubin. Other studies demonstrated successful application of sorbents to treat autoimmune diseases. Special attention is paid to hemoperfusion in as a possible treatment for severe sepsis and septic shock. The review justifies importance of development and application of novel multimodal sorbents, which combine both properties of selective and nonselective sorbents. The review discusses clinical efficacy of hemoperfusion and key molecular interactions between the sorbent and circulating molecules pathogenetically relevant to developing critical illness and severe diseases. The reference list: 137.В обзоре рассмотрены сорбенты и медицинские изделия на их основе, применяемые в клинической практике для экстракорпоральной детоксикации с помощью процедуры гемосорбции. Представлены данные исследователей, свидетельствующие об эффективности такого подхода с целью удаления бактериальных эндотоксинов, липопротеинов низкой плотности, билирубина, а также при лечении аутоиммунных заболеваний. Основное внимание уделено применению гемосорбции при лечении тяжелого сепсиса и септического шока. Обосновывается необходимость разработки и применения новых «мультимодальных» сорбентов, сочетающих свойства как «селективных», так и «неселективных» сорбентов. В обзоре приведены сведения о клинической эффективности гемосорбции и молекулярном взаимодействии сорбента с циркулирующими молекулами, патогенетически значимыми для развития критических состояний и тяжелых заболеваний. Библиография — 137 ссылок

Investigation on the co-precipitation of transuranium elements from alkaline solutions by the method of appearing reagents

Highly alkaline radioactive waste solutions originating from production of plutonium for military purposes are stored in underground tanks at the U.S. Department of Energy Hanford Site. The purification of alkaline solutions from neptunium and plutonium is important in the treatment and disposal of these wastes. This report describes scoping tests with sodium hydroxide solutions, where precipitation techniques were investigated to perform the separation. Hydroxides of iron (III), manganese (II), cobalt (II, III), and chromium (III); manganese (IV) oxide, and sodium uranate were investigated as carriers. The report describes the optimum conditions that were identified to precipitate these carriers homogeneously throughout the solution by reductive, hydrolytic, or catalytic decomposition of alkali-soluble precursor compounds by a technique called the Method of Appearing Reagents. The coprecipitation of pentavalent and hexavalent neptunium and plutonium was investigated for the candidate agents under optimum conditions and is described in this report along with the following results. Plutonium coprecipitated well with all tested materials except manganese (IV) oxide. Neptunium only coprecipitated well with uranate. The report presents a hypothesis to explain these behaviors. Further tests with more complex solution matrices must be performed

A Model of the Electronic Structure of a FeRh Alloy Undergoing an Antferromagnetic–Ferromagnetic Phase Transition

Abstract: A new approach to describing the magnetic properties of FeRh alloys is proposed. It is based on two assumptions about the properties of 3d and 4d electrons in these alloys. The first is the assumption that the 4d band is submerged under the Fermi level to a depth that ensures its complete filling at a temperature T = 0 K. The second is the assumption that there are two different spatial distributions of 3d and 4d electrons that are compatible with one atomic structure. The first assumption makes it possible to explain the absence of uncompensated spins of 4d electrons in the low-temperature antiferromagnetic (AFM) phase of FeRh. The second assumption is proposed to explain the strong changes in the spin structure of the FeRh alloy upon the AFM–FM transition, while its atomic structure is almost unchanged. Attempts have been made to predict the new properties of the FeRh alloy that follow from these assumptions. Our second assumption proved to be successful and enabled us to predict the existence of local magnetic moments of 3d electrons in the AFM phase, which are larger than the magnetic moments of Fe ions. Measurements of the magnetic susceptibility of the FeRh alloy in the AFM phase confirmed this prediction. © 2022, The Author(s).Ministry of Education and Science of the Russian Federation, Minobrnauka, (AAAA-A18-118020190095-4)This work was carried out within a state task of the Ministry of Education and Science of the Russian Federation (subject “Quantum”, state registration no. AAAA-A18-118020190095-4)