Tungstate Based Ceramics Obtained By Spark Plasma Sintering Method – Possible Material for Consolidation of Radioactive Wastes’ Components

The Spark Plasma Sintering method was used to produce high-density ceramics from tungstates SrWO4 and NaNd(WO4)2 with scheelite structure. These compounds are proposed as possible matrices for the consolidation of radwaste components. Powder samples were obtained by coprecipitation method and studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). After sintering, the samples retained their phase identity (scheelite structure). The total duration of sintering was ∼ 13-15 min, the relative density was reached ∼ 92, 99%. Keywords: Tungstates, RW, Spark Plasma Sintering, high density, microstructur

Investigation of the microstructure of the fine-grained YPO4_4:Gd ceramics with xenotime structure after Xe irradiation

The paper reports on the preparation of xenotime-structured ceramics by the Spark Plasma Sintering (SPS) method. Phosphates Y$_{0.95}$Gd$_{0.05}$PO$_4$ (YPO$_4$:Gd) were obtained by the sol-gel method. The synthesized nanopowders are collected in large agglomerates 10-50 mkm in size. Ceramics has a fine-grained microstructure and a high relative density (98.67%). The total time of the SPS process was approximately 18 min. High-density sintered ceramics YPO$_4$:Gd with a xenotime structure were irradiated with Xe$^{+26}$ ions (E = 167 MeV) to fluences of $1\times10^{12}$-$3\times 10^{13}$ cm$^{-2}$. Complete amorphization at maximum fluence was not achieved. As the fluence increases, an insignificant increase in the depth of the amorphous layer is observed. According to the results of grazing incidence XRD (GIXRD), with an increase in fluence from $1\times10^{12}$-$3\times 10^{13}$ cm$^{-2}$, an increase in the volume fraction of the amorphous structure from 20 to 70% is observed. The intensity of XRD peak 200 YPO$_4$:Gd after recovery annealing (700$^\circ$C, 18 h) reached a value of ~80% of the initial intensity I0.Comment: 16 pages, 10 figure

CHARACTERISTICS OF SUPERCAPACITORS ELECTRODES BASED ON TITANIA AND CARBON NANOTUBES

TiO2-NT and CNT based electrodes have been fabricated by anodizing and pyrolysis and characterized by scanning electron microscope. Electrochemical performances such as spe-cific capacitance, energy and power have been calculated in frame of the galvanostatic charge-discharge curves analysis.Исследование выполнено в рамках инициативного научного проекта FEUZ-2020-0059 Минобрнауки РФ

Development of the composition and technology of a granular dosage form based on a thick milk thistle extract and ademetionine

Introduction. The creation of rational combined medicines with hepatoprotective activity is an urgent task of medicinal science. Ademetionin shows pharmacological ef-fectiveness in cytolysis, cholestasis, synthetic insufficiency. Silybin, in turn, is effective in cytolysis, synthetic insufficiency, mesenchymal inflammation, fibrosis and pathological regeneration. Thus, the combination of these substances covers almost the entire set of clinical and morphological syndromes of liver damage and has a wide range of effects in various liver pathologies. Aim. The purpose of this study was to develop a combined granular dosage form containing a thick extract of milk thistle, ademetionin and analytical support for this process. Materials and methods. To obtain a thick extract from the fruits of Silybum marianum L. a traditional percolation method was used in a battery of 3 diffusers. Extractant removal was performed using a rotary evaporator IR-1M3 under vacuum. For the analysis of silybin in the obtained thick extract from the fruit of S. marianum L. the method of HPLC was used. Validation evaluation of the method was performed according to generally accepted parameters. Results and discussion. A modular combined dosage form based on a thick extract of S. marianum L. and ademethionine was developed. Lactose was introduced as an auxiliary agent. The quality of pellets was evaluated according to generally accepted criteria. The validation parameters of the manufactured dosage form were determined using the HPLC method. Accuracy and precision were determined by the method of additives in a series of 9 experimental samples of granules. The results of determining the linearity, precision and correctness of the method for determining silybin and ademetionin in a combined model drug form showed correct results. Conclusion.Thus, a combined granular dosage form containing a thick extract of milk thistle, ademetionin, has been developed. Analytical support of this process using the HPLC method was performed. Validation studies of the developed methodology were carried out. The field of application of the obtained results is practical pharmacy. Further research should concern the conduct of a set of pharmacological tests. © Pisarev D. I., Novikov О. О., Zhilyakova Е. Т., Boyko N. N., Abramovich R. А., Potanina О. G., Lazar S., Ahmad A. S., Nasser R., 2020

Studying and modeling of the extraction properties of the natural deep eutectic solvent and sorbitol-based solvents in regard to biologically active substances from glycyrrhizae roots

The purpose of this work was the studying and modeling of the extraction properties of the sorbitol-based natural deep eutectic solvent (NADES) and sorbitol-based solvents in regard to biologically-active substances (BASs) from Glycyrrhizae roots using theoretical fundamentals based on the laws of statistical physics, thermodynamics, and physical chemistry previously developed by us. In our studies, we used Glycyrrhizae roots, simple maceration, plant raw material:solvent ratio 1:10 w/v, temperature 25 ◦C, extraction time 24 h; standards of licuroside and glycyram; RP HPLC, differential scanning calorimetry, integral dielectric, impedance and conductivity spectroscopy method of analysis; the following solvents: sorbitol-based NADES sorbitol:malic acid:water (1:1:3 in molar ratio), a modified solvent based on NADES sorbitol:malic acid:water:glycerin (1:1:1:1 in molar ratio) and sorbitol-based solvents sorbitol:ethanol:water at different ratios. It has been found that regression equations for sorbitol-based solvents in coordinates predicted by the theory have a high value of determination coefficient that equals to R2 e = 0.993 for glycyram and R2 e = 0.976 for licuroside. It has been found that the extraction properties of sorbitol-based NADES with a dielectric constant (ε) equal to 33 ± 2 units are equivalent to those of the sorbitol:ethanol:water solvent with ε = 34 units, and the extraction properties of modified solvent based on NADES with ε = 41 ± 2 units are inferior to those of the sorbitol-ethanol-water solvents with maximum value of BASs yield with the dielectric constant range 40 ÷ 50 units. The theoretical fundamentals suggested provide a possibility for an explanation of the mechanism, quantitative description of the extraction properties of the solvent, and target search of the optimal solvent by its dielectric constant. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

A Technology for Isolation and Analysis of Lipophilic and Hydrophilic Biologically Active Components from <i>N. sativa</i> L. Seeds.

Introduction. Seeds of Nigella sativa L. are widely known as a source of fatty oil with a very rare component-thymoquinone. The therapeutic potential of biologically active compounds of plant seeds covers a positive effect on the gastrointestinal tract, cardiovascular and immune systems. In addition, hypoglycemic, antioxidant, antitumor, oncoprotective, immunomodulating effects were found in thymoquinone. In addition to fatty oil and thymoquinone, a number of other significant compounds are present in the seeds, which also make up their own pharmacological asset. Aim. Study was to develop a processing flow chart and analyze the lipophilic and hydrophilic components of the seeds of N. sativa L.Materials and methods. The following methods were used as analytical methods: gas-liquid chromatography with a flame ionization detector - for the analysis of sterols and triterpenes; chromatography-mass spectrometry (gas-liquid chromatography with mass spectrometric detection) - for the study of essential oil; chromatography-mass spectrometry (high performance liquid chromatography with mass spectrometric detection) - to study flavonoids. To obtain individual fractions of biologically active compounds of seeds of N. sativa L., fractional extraction was used.Results and discussion. The principle of this approach in this case is to extract the entire lipid complex of seeds with n-hexane, followed by removal of the extractant. The thickened hexane extract is treated with ethyl alcohol, which extracts unsaponifiable compounds - terpenes, quinones, sterols and does not dissolve triacylglycerides. The seed meal remaining after hexane extraction is treated with ethyl alcohol 70 %, into which hydrophilic molecules, in particular flavonoids, pass.Conclusion. After transesterification, 5 compounds were identified in the lipophilic fraction of saponifiable lipids, the linoleic and oleic acids being dominant. A characteristic feature of this fraction is the presence of cis-11,14-eicosadiene acid, which can act as a marker element of the fatty oil of the seeds of N. sativa L. Sterols and triterpenes were found in the unsaponifiable fraction. The major component of this fraction is β-sitosterol. In addition to the indicated sterol, campesterol and stigmasteri are present. Triterpenes are represented by cycloartenol and its derivatives. Simple phenols, quinones and monoterpenes were found in the essential oil complex, p-cymol, thymoquinone and α-thuyen predominate. The hydrophilic fraction of the seeds of N. sativa L. includes flavonoids of the methoxylated series of flavones and kempferol glycosides