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Abstract: The possibilities of creating special-purpose ceramics by the spark plasma sintering (SPS) according to the principle of the low-voltage electro-pulse consolidation of powders under the conditions of an external mechanical load is investigated. Ceramics applicable in the nuclear, medical, and electrotechnical industries are fabricated. A methodological description and special features of the presented technique are provided for the first time in terms of fabricating nuclear ceramics in the form of a pellet product of UO2; composite bioceramics with a theoretical density exceeding 97.6% (based on ZrO2 doped by hydroxyapatite) characterized with controlled (meso-, macro-) porosity and a high compression strength of ~400 MPa; and magnetic ceramics resistant to reverse magnetization based on nanostructured iron oxides (Fe3O4/α-Fe2O3) with a saturation magnetization of 50 emu/g. [ABSTRACT FROM AUTHOR]

Studies the synthesis and crystal structure of the first uranyl selenite(IV)—selenate(VI) [C5H14N][(UO2)(SeO4)(SeO2OH)]. Coordinates and displacement parameters of atoms in the compound; Determination of unit cell parameters; Bond valences.

The effectiveness of photodynamic therapy (PDT) is based on the triad effects of photosensitizer (PS), molecular oxygen and visible light on malignant tumors. Such complex induces a multifactorial manner including reactive-oxygen-species-mediated damage and the killing of cells, vasculature damage of the tumor, and activation of the organism immunity. The effectiveness of PDT depends on the properties of photosensitizing drugs, their selectivity, enhanced photoproduction of reactive particles, absorption in the near infrared spectrum, and drug delivery strategies. Photosensitizers of the tetrapyrrole structure (porphyrins) are widely used in PDT because of their unique diagnostic and therapeutic functions. Nevertheless, the clinical use of the first-generation PS (sodium porfimer and hematoporphyrins) revealed difficulties, such as long-term skin photosensitivity, insufficient penetration into deep-seated tumors and incorrect localization to it. The second generation is based on different approaches of the synthesis and conjugation of porphyrin PS with biomolecules, which made it possible to approach the targeted PDT of tumors. Despite the fact that the development of the second-generation PS started about 30 years ago, these technologies are still in demand and are in intensive development, especially in the direction of improving the process of optimization split linkers responsive to input. Bioconjugation and encapsulation by targeting molecules are among the main strategies for developing of the PS synthesis. A targeted drug delivery system with the effect of increased permeability and retention by tumor cells is one of the ultimate goals of the synthesis of second-generation PS. This review presents porphyrin PS of various generations, discusses factors affecting cellular biodistribution and uptake, and indicates their role as diagnostic and therapeutic (theranostic) agents. New complexes based on porphyrin PS for photoimmunotherapy are presented, where specific antibodies are used that are chemically bound to PS, absorbing light from the near infrared part of the spectrum. Additionally, a two-photon photodynamic approach using third-generation photosensitizers for the treatment of tumors is discussed, which indicates the prospects for the further development of a promising method antitumor PDT.

An Se-derivative of amidoxime was synthesized for the first time as a result of the reaction of oxidative polycondensation of N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide with SeO 2 : its elementary units are linked to each other due to the formation of strong diselenide bridges. The element composition of the material was established, and the structure of the elementary unit was suggested. The sorption-selective properties were evaluated, and it was found that the adsorbent can be used for the selective recovery of U (VI) from liquid media with a pH of 6-9. The effect of some anions and cations on the efficiency of recovery of U (VI) was estimated. Composite materials were fabricated, in which silica gel with a content of 35, 50, and 65 wt.% was used as a matrix to be applied in sorption columns. The maximum values of adsorption of U (VI) calculated using the Langmuir equation were 620-760 mg g -1 and 370 mg g -1 for the composite and non-composite adsorbents, respectively. The increase in the kinetic parameters of adsorption in comparison with those of the non-porous material was revealed, along with the increase in the specific surface area of the composite adsorbents. In particular, the maximum sorption capacity and the rate of absorption of uranium from the solution increased two-fold.