Moscow University Chemistry Bulletin最新文献

This article dealt with the saturated solubility values of deferiprone (which is an iron chelator agent) in aqueous mixtures of 1-propanol using experimental measurements as well as mathematical correlations. The solubility of deferiprone demonstrated a positive correlation with temperature and 1-propanol content. Four mathematical models were employed to correlate the solid-liquid equilibrium data, and the fitting results demonstrated that the computed solubility results from the employed computational cosolvency models were in good agreement with the experimental data. It was anticipated that these experimental solubilities, density values, and correlation results can be employed for pharmaceutical development such as purification, drug manufacturing, crystallization, and extraction on an industrial scale as well as in theoretical research.

The development of new heat-resistant cobalt alloys for the aerospace industry allows exceeding the temperature capabilities of nickel superalloys. Cobalt alloys, however, are less resistant to high-temperature oxidation, and alloying cobalt alloys with aluminum or chromium can lead to the formation of brittle topologically dense phases. As a solution to this problem, surface alloying with the chromium of cobalt alloys, carried out by the interaction of their preoxidized surface with chromium from the gas phase, is proposed.

This review focuses on the main methods for obtaining functionally substituted phthalocyanine complexes, as well as the precursor phthalonitriles containing various hydrophilic and hydrophobic groups. It presents a comparison of the optical and photochemical properties of phthalocyanines, including pathways for generating reactive oxygen species. The potential applications of phthalocyanines are outlined, including photocatalysis, fluorescent diagnostics, and photodynamic therapy for cancer and antibacterial treatments.

The use of drug delivery systems requires an understanding of the release kinetic patterns of an encapsulated drug or a model compound. In this work, the zero-order release of the pH-sensitive nitroxide radical 5,5-dimethyl-4-dimethylamino-2-ethyl-2-(4-pyridyl)-2,5-dihydroimidazole-1-oxyl (DPI) from poly-D,L-lactide (PDLLA) films into aqueous buffer solution was studied with continuous-wave electron paramagnetic resonance spectroscopy (EPR). The EPR method allowed for quantifying the DPI release kinetics from PDLLA films and analyzing rotational mobility and the concentration of the spin probe inside the films during their swelling and degradation. The EPR data were globally analyzed within the previously proposed phenomenological diffusion model based on the processes of pores formation and overgrowth in polyester films. The interaction between the doubly protonated DPI cation, formed in acid media inside the polymer pores, and the counterions of (oligo)lactic acid is proposed. Such interaction leads to the formation of bulk DPI-containing paramagnetic aggregates which make the release kinetics diffusion-controlled. This is in contrast to the pore-formation control observed for the standard spin probe 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxide (TEMPOL). Therefore, the release rate depends on the thickness of the film and the size and the charge of the dopant. Keywords: poly-D,L-lactide films; spin probes; electron paramagnetic resonance; mechanism of drug release; mathematical model of the release kinetics; zero-order release.

The development of efficient and environmentally friendly thermoelectric materials for mid-temperature applications, in the range of 200–500°С, follows the necessity to create devices for saving electricity, and in particular, for converting waste heat into electric power. This review surveys the evolution of thermoelectric materials from the initial approaches of Abram Ioffe to modern ideas using the examples of various substances including chalcogenides, pnictides, and intermetallic compounds. Special attention is paid to the implementation of new concepts for the development of thermoelectric materials from inexpensive and environmentally friendly substances for mid-temperature applications, primarily in the automotive industry.

In this short review, we attempt to analyze and summarize the existing trends related to the development of solid-state polymer-based electrolytes for lithium-ion batteries. Mechanisms of the ion conductivity and modern approaches to the optimization of solid polymer electrolytes and creation of composite polymer electrolytes are considered. The possible promising approaches to the development of efficient solid-state polymer electrolytes are assessed.

This review addresses the issue of efficient and selective extraction of uranium(VI) from various media using systems based on ionic liquids. It examines the current technological process for extracting uranium(VI) from spent nuclear fuel solutions and identifies its shortcomings. This review analyzes and systematizes information on the main types of ionic liquids being studied for uranium(VI) extraction, either as solvents, extractants, or in their pure form. Special attention is given to commercially available ammonium and phosphonium ionic liquids, which have demonstrated high efficiency in extracting uranium(VI) from hydrochloric and alkaline media, while in nitric acid media, the highest distribution coefficients are observed for tetravalent actinides [1].

Aromatic and, in peculiar, polyaromatic hydrocarbons are one of the common class of anthropogenic pollutants. Processes of their degradation are of great interest from an ecological point of view. This article describes the current situation in the use of ultrasound as an instrument, accelerating such degradation.

The reasons for discordance data on the contribution of a TUBB3 microtubule protein to resistance to antitumor drugs and the metastatic potential of tumors with an assessment of prognostic significance of TUBB3 expression in nonsmall cell lung cancer tissue are analyzed. The need to introduce quantitative analysis methods in molecular diagnostics of tumors (in particular, immunofluorescence assessment associated with flow cytometry) is substantiated.

The study of ytterbium halide crystals using the compound-tunable embedding potential (CTEP) method is carried out in the framework of the density functional theory. For subsequent calculations the optimization of atomic bases is carried out, and for this purpose stoichiometric molecular systems were studied, using the coupled-cluster methods. The chemical shift of the lines of the X-ray emission spectrum, K_α1 and K_α2, in YbHal₃ relative to YbHal₂ was chosen as a criterion for verifying the computational accuracy of the properties localized on the nucleus of a heavy atom, Yb, since this method is a unique tool for analyzing partial electron densities near a heavy nucleus specifically for compounds of d- and f-elements. In the study, five main versions for the halogen basis set sizes were considered. The stability of the results was obtained using the CCSD and CCSD(T) coupled cluster methods for molecular systems YbF₂, YbF₃, YbCl₂ and YbCl₃.