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The thermal conductivity of natural monoliths of calcite, dolomite marble, and limestone from various deposits was measured using the absolute stationary method of longitudinal heat flow in the temperature range of 50–300 K and the dynamic method in the range of 323–573 K. A majority of calcite marbles were inferior in thermal conductivity to dolomite marbles. At room temperature, the thermal conductivity coefficients of all studied samples were lower k = 5 W/(m K). The obtained data were compared with the literature data. The diversity of experimental data from different authors on the thermal conductivity of carbonates is associated with qualitative differences in the samples studied

Photonic crystal opal matrices are bulk spatial periodic structures based on amorphous spherical silica particles whose size is compatible with the wavelengths of the visible light spectrum. These structures are very promising and can be used as matrices for new functional materials. The article studies the formation of a regular opal structure on dielectric substrates by means of the evaporation of droplets and layers of colloidal solutions based on water and ethanol with various oncentrations of spherical SiO2 particles with a diameter of about 250 nm synthesised using the Stöber method.

Various gelatin-containing gel materials are used as scaffolds for animal and human cell culturing within the fields of cell technologies and tissue engineering. Cryostructuring is a promising technique for the preparation of efficient macroporous scaffolds in biomedical applications. In the current study, two new gelatin-based cryostructurates were synthesized, their physicochemical properties and microstructure were evaluated, and their ability to serve as biocompatible scaffolds for mammalian cells culturing was tested. The preparation procedure included the dissolution of Type A gelatin in water, the addition of urea to inhibit self-gelation, the freezing of such a solution, ice sublimation in vacuo, and urea extraction with ethanol from the freeze-dried matter followed by its cross-linking in an ethanol medium with either carbodiimide or glyoxal. It was shown that in the former case, a denser cross-linked polymer phase was formed, while in the latter case, the macropores in the resultant biopolymer material were wider. The subsequent biotesting of these scaffolds demonstrated their biocompatibility for human mesenchymal stromal cells and HepG2 cells during subcutaneous implantation in rats. Albumin secretion and urea synthesis by HepG2 cells confirmed the possibility of using gelatin cryostructurates for liver tissue engineering.

Object. The article describes a new geological and geochemical data for Permian host rocks and copper sandstones (CS) in Orenburg’s Pre-Urals. Methods . X-ray fluorescence, atomic absorption for Au and Ag, and ICP-MS analysis were used during investigations. Results. The cupriferous sandstones are enriched in a quite broad range of microelements: Cu, Ag, Au, Cd, Сr, Ni, Mn, Co, V, U, Sc, and Pb, compared to the average values of the upper crust. The Co/Ni ratio in the CS is very low, which is typical of low-thermal fluids of meteoric origin. The CS are characterized by a REE spectrum without Eu-minima and maxima, which is close to the chondrite spectrum. Like in the host rocks, the “cerium” group of REE dominates in the CS over the “yttrium” and “scandium” groups. The spectra of REE of the CS and the host rocks have definitely similar morphology. The δCe and δEu combination indicates that CS was formed under oxidizing conditions. On geological and genetic characteristics and geochemical indicators installed the similarity of the CS in the southern Pre-Urals deposits and the Manto-type Cu-Ag deposits of Chile and Iran, and also with the CS of Iran and Cu-shales of Kupferschiefer. Conclusion. Proposed geological-genetic model of CS, points to possible high rise development of the Cu-Ag mineralization at depth as in the fields of the Manto-type copper deposits in Chile and Iran. Geochemical data show that accommodating the Permian strata could serve as a source of REE and other trace elements for ore-forming fluids. Perm CS of Pre Urals can be considered as a very promising new (“old”) source of raw materials for the development of the copper industry of the region. The obtained results can be used to predict new ore fields in the Eastern Russia region.

One of the leading trends in the modern tissue engineering is the development of new effective methods of decellularization aimed at the removal of cellular components from a donor tissue, reducing its immunogenicity and the risk of rejection. Supercritical CO2 (scCO2)-assisted processing has been proposed to improve the outcome of decellularization, reduce contamination and time costs. The resulting products can serve as personalized tools for tissue-engineering therapy of various somatic pathologies. However, the decellularization of heterogeneous 3D structures, such as the aortic root, requires optimization of the parameters, including preconditioning medium composition, the type of co-solvent, values of pressure and temperature inside the scCO2 reactor, etc. In our work, using an ovine aortic root model, we performed a comparative analysis of the effectiveness of decellularization approaches based on various combinations of these parameters. The protocols were based on the combinations of treatments in alkaline, ethanol or detergent solutions with scCO2-assisted processing at different modes. Histological analysis demonstrated favorable effects of the preconditioning in a detergent solution. Following processing in scCO2 medium provided a high decellularization degree, reduced cytotoxicity, and increased ultimate tensile strength and Young’s modulus of the aortic valve leaflets, while the integrity of the extracellular matrix was preserved.

The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail Helix lucorum exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight. Absence of light during the mission also affected statocyst physiology, as revealed by comparison to dark-conditioned control groups. Readaptation to normal tilt responses occurred at ~20 h following return to Earth. Despite the permanence of gravity, the snail responded in a compensatory manner to its loss and readapted once gravity was restored.

Abstract We propose a machine-learning interatomic potential for multi-component magnetic materials. In this potential we consider magnetic moments as degrees of freedom (features) along with atomic positions, atomic types, and lattice vectors. We create a training set with constrained DFT (cDFT) that allows us to calculate energies of configurations with non-equilibrium (excited) magnetic moments and, thus, it is possible to construct the training set in a wide configuration space with great variety of non-equilibrium atomic positions, magnetic moments, and lattice vectors. Such a training set makes possible to fit reliable potentials that will allow us to predict properties of configurations in the excited states (including the ones with non-equilibrium magnetic moments). We verify the trained potentials on the system of bcc Fe–Al with different concentrations of Al and Fe and different ways Al and Fe atoms occupy the supercell sites. Here, we show that the formation energies, the equilibrium lattice parameters, and the total magnetic moments of the unit cell for different Fe–Al structures calculated with machine-learning potentials are in good correspondence with the ones obtained with DFT. We also demonstrate that the theoretical calculations conducted in this study qualitatively reproduce the experimentally-observed anomalous volume-composition dependence in the Fe–Al system.