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Relevance. The search for a useful application of carbonaceous residues of rice husks thermal processing. These residues due to high silicon content in the inorganic part can potentially be used to produce silicon carbide – an important functional material for various fields of science and technology. Useful utilization of this waste will allow not only solving the environmental problem associated with their inefficient application and formal disposal, but also obtaining value-added products in the form of SiC-based ceramics. Aim. To obtain SiC-based bulk products from carbonaceous residues of rice husk thermal processing by spark plasma sintering with a minimum number of additional stages of feedstock processing. Objects. SiC-based bulk products obtained using carbonaceous residues of rice husk thermal processing. The samples were obtained by spark plasma sintering at 1800 °C, pressure of 60 MPa and holding time of 10 minutes. Methods. Spark plasma sintering; X-ray diffractometry (X-ray phase analysis); scanning electron microscopy; vacuumless arc discharge synthesis method. Results. The authors have carried out the experimental studies to assess the possibility of applying carbonaceous residue of rice husk thermal processing as a precursor for the synthesis of silicon carbide in bulk (ceramics) and dispersed (powder) forms. A series of experiments on spark plasma sintering of carbonaceous residue from rice husk thermal processing in the initial and milled form, with SiO2 silica sand additives, as well as with the use of silicon carbide powders synthesized from carbonaceous residue by vacuumless arc discharge method were implemented. The latter is performed within a one-stage fast-flowing process in an air environment and does not require the use of a vacuum system. Preliminary results demonstrated the possibility of obtaining bulk products and dispersed powders based on silicon carbide with a content of at least 50 and 60 wt %, respectively, and indicate the prospects of further increasing phase purity by optimizing spark plasma sintering and vacuumless arc discharge synthesis.

Abstract Proteorhodopsins (PRs), bacterial light-driven outward proton pumps comprise the first discovered and largest family of rhodopsins, they play a significant role in life on the Earth. A big remaining mystery was that up-to-date there was no described bacterial rhodopsins pumping protons at acidic pH despite the fact that bacteria live in different pH environment. Here we describe conceptually new bacterial rhodopsins which are operating as outward proton pumps at acidic pH. A comprehensive function-structure study of a representative of a new clade of proton pumping rhodopsins which we name “mirror proteorhodopsins”, from Sphingomonas paucimobilis (SpaR) shows cavity/gate architecture of the proton translocation pathway rather resembling channelrhodopsins than the known rhodopsin proton pumps. Another unique property of mirror proteorhodopsins is that proton pumping is inhibited by a millimolar concentration of zinc. We also show that mirror proteorhodopsins are extensively represented in opportunistic multidrug resistant human pathogens, plant growth-promoting and zinc solubilizing bacteria. They may be of optogenetic interest.

Abstract Despite remarkable progress, mainly due to the development of LCP and ‘bicelle’ crystallization, lack of structural information remains a bottleneck in membrane protein (MP) research. A major reason is the absence of complete understanding of the mechanism of crystallization. Here we present small-angle scattering studies of the evolution of the “bicelle” crystallization matrix in the course of MP crystal growth. Initially, the matrix corresponds to liquid-like bicelle state. However, after adding the precipitant, the crystallization matrix transforms to jelly-like state. The data suggest that this final phase is composed of interconnected ribbon-like bilayers, where crystals grow. A small amount of multilamellar phase appears, and its volume increases concomitantly with the volume of growing crystals. We suggest that the lamellar phase surrounds the crystals and is critical for crystal growth, which is also common for LCP crystallization. The study discloses mechanisms of “bicelle” MP crystallization and will support rational design of crystallization.

Abstract Two-component systems (TCS) are widespread signaling systems present in all domains of life. TCS typically consist of a signal receptor/transducer and a response regulator. The receptors (histidine kinases, chemoreceptors and photoreceptors) are often embedded in the membrane and have a similar modular structure. Chemoreceptors were shown to function in highly ordered arrays, with trimers of dimers being the smallest functional unit. However, much less is known about photoreceptors. Here, we use small-angle scattering (SAS) to show that detergent-solubilized sensory rhodopsin II in complex with its cognate transducer forms dimers at low salt concentration, which associate into trimers of dimers at higher buffer molarities. We then fit an atomistic model of the whole complex into the SAS data. The obtained results suggest that the trimer of dimers is "tripod"-shaped and that the contacts between the dimers occur only through their cytoplasmic regions, whereas the transmembrane regions remain unconnected.

Abstract: Management of projects in Russia in recent years is widely used in various fields and industries. Projects in various fields, various specialists have significant differences among themselves. Therefore, to select the optimal approach to the management of the specific project you first need to identify the distinctive features of this type and type of project. The use of the classification of projects as the basis of the structural vision allows optimizing methods and tools for the management of specific projects and increase the effectiveness of their implementation. In the article the analysis of the classification of projects in project management.Identified the main classification criteria and types of projects that are widely used in the scientific literature and practice. In the course of the analysis, identified new approaches to the classification of the various projects of Russian and foreign authors, the author gives his own evaluation of such approaches, and reveals the positive aspects and shortcomings of such approaches. During the conducted research it is established that the presented approaches to the classification of project management did not sufficiently take into account the area of the economy in which they are implemented. So, the projects implemented in various areas of the economy, as a rule, have different objectives. Consequently, the classification of projects in project management for individual sectors may be applied only for that sector of the economy the shape and type of the project and have their classification criteria. As a separate sector of the economy considered the oil and gas industry, which forms the basis of the state budget of many States, including the Russian Federation. The article describes the most well-known oil and gas projects implemented in recent years. Analysis we analyzed projects have shown that they have several features that differ from other projects. Therefore, for a detailed classification of oil and gas projects us presents the author's classification criteria for projects that have a significant impact on the financial costs and timing of oil and gas project.

This is a review of relevant Raman spectroscopy (RS) techniques and their use in structural biology, biophysics, cells, and tissues imaging towards development of various medical diagnostic tools, drug design, and other medical applications. Classical and contemporary structural studies of different water-soluble and membrane proteins, DNA, RNA, and their interactions and behavior in different systems were analyzed in terms of applicability of RS techniques and their complementarity to other corresponding methods. We show that RS is a powerful method that links the fundamental structural biology and its medical applications in cancer, cardiovascular, neurodegenerative, atherosclerotic, and other diseases. In particular, the key roles of RS in modern technologies of structure-based drug design are the detection and imaging of membrane protein microcrystals with the help of coherent anti-Stokes Raman scattering (CARS), which would help to further the development of protein structural crystallography and would result in a number of novel high-resolution structures of membrane proteins—drug targets; and, structural studies of photoactive membrane proteins (rhodopsins, photoreceptors, etc.) for the development of new optogenetic tools. Physical background and biomedical applications of spontaneous, stimulated, resonant, and surface- and tip-enhanced RS are also discussed. All of these techniques have been extensively developed during recent several decades. A number of interesting applications of CARS, resonant, and surface-enhanced Raman spectroscopy methods are also discussed.