Geological-hydrogeochemical characteristics of a "silver spring" water source (the Lozovy ridge)

Geological and hydrogeological characteristics of the Lozovy ridge (Southern Primorye) are studied, as far as karst phenomena are widely distributed within its boundaries. Water-bearing rocks of the karst water source "Silver Spring" ("Serebryany Klyuch"), which is located near the bottom of the "Bear's fang" ("Medvezhiy klyk") cave, are investigated. It is found that karst rocks are presented by calcite (CaCO[3]), and an accessory mineral is barite (BaSO[4]). It is determined that among the trace elements forming the composition of carbonate water-bearing rocks the maximum concentrations are typical for Sr, Ba, Fe, Al, Za, Mn, Cu, and Ni. Also, the chemical composition of the waters taken from the "Silver Spring" water source is studied. These waters are fresh, hydrocarbonate, calcium, and weakly alkaline. Among the elements of the spring, such elements as Sr, Ba, Fe, Al, Zn, Mn, Cu, and Ni have the maximum concentration. The other elements have concentrations less than 1 [mu]g/l

Accelerated synthesis of Sn-BEA in fluoride media:effect of H₂O content in the gel

Sn-BEA synthesis in concentrated gels results in 2.5–4 fold reduction of crystallization time and formation of smaller zeolite crystals.</p

CHEMICAL PROPERTIES AND APPLICATIONS OF NITROPYRIDINES

Background. Pyridines are one of the most common heterocycles, the derivatives of which are widely used in pharmaceuticals, agrochemistry, and also in the production of new materials. Therefore, a comprehensive study of the chemical behavior of various pyridine derivatives will continue to be an urgent task of organic chemistry. This literature review is devoted to the systematization and analysis of the chemical properties of pyridine nitro derivatives, starting from the first half of the 20th century and up to the present. The paper considers both reactions proceeding through the nitro group (reduction under the action of various chemical agents, substitution, condensation) and reactions through the pyridine cycle. The main areas of application of nitropyridines are also shown. Purpose. Generalize and systematize the main types of reactions characteristic of nitropyridines, show the features of their chemical properties associated with the transformation of the nitro group, its effect on the mobility of substituents in the pyridine ring, as well as on the activity of the heterocycle as a whole. Materials and methods. To achieve the goal of the study, a review of the scientific literature was made on the main types of chemical reactions characteristic of pyridine nitro derivatives and the most significant areas of their application. Results. This paper summarizes the results of experimental studies on the chemical properties and application of nitropyridines from the beginning of the last century to the present. Conclusion. Thus, as a result of the analysis of sources devoted to the chemical properties and application of nitropyridines, a brief literature review was compiled, including the main types of reactions characteristic of the compounds under study, and their main areas of application were identified

Structure and optical-mechanical properties of the Zr-Y-O coatings deposited by pulse magnetron sputtering on optical glass

The results of the research of the phase composition and the mechanical properties of the coatings on the basis of the Zr-Y-O system produced by pulsed magnetron sputtering on the K208 glass substrates are presented in this paper. By the X-ray diffraction method it has been discovered that there is the ZrO2 phase in two modifications in the coatings. The deposition of the Zr-Y-O coating system allows not only to increasing the microhardness of the surface layer of the K208 glass up to ~19 GPa, but also maintain a high level of the elastic properties (We> 0.70). The laboratory tests have been carried out on the impact of the high-speed flows of iron microparticles on the Zr-Y-O protective coating produced by pulsed magnetron sputtering. When a high-speed flow of iron microparticles impact the samples with the Zr-Y-O coatings the surface density of the craters decreases ~ 7 times compared with initial state

C\u3csub\u3e60\u3c/sub\u3e fullerenes selectively inhibit BK\u3csub\u3eCa\u3c/sub\u3e but not K\u3csub\u3ev\u3c/sub\u3e channels in pulmonary artery smooth muscle cells

© 2019 Elsevier Inc. Possessing unique physical and chemical properties, C60 fullerenes are arising as a potential nanotechnological tool that can strongly affect various biological processes. Recent molecular modeling studies have shown that C60 fullerenes can interact with ion channels, but there is lack of data about possible effects of C60 molecule on ion channels expressed in smooth muscle cells (SMC). Here we show both computationally and experimentally that water-soluble pristine C60 fullerene strongly inhibits the large conductance Ca2+-dependent K+ (BKCa), but not voltage-gated K+ (Kv) channels in pulmonary artery SMC. Both molecular docking simulations and analysis of single channel activity indicate that C60 fullerene blocks BKCa channel pore in its open state. In functional tests, C60 fullerene enhanced phenylephrine-induced contraction of pulmonary artery rings by about 25% and reduced endothelium-dependent acetylcholine-induced relaxation by up to 40%. These findings suggest a novel strategy for biomedical application of water-soluble pristine C60 fullerene in vascular dysfunction

Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate

We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Brønsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations

Yang-Mills instantons and dyons on homogeneous G_2-manifolds

We consider Lie G-valued Yang-Mills fields on the space R x G/H, where G/H is a compact nearly K"ahler six-dimensional homogeneous space, and the manifold R x G/H carries a G_2-structure. After imposing a general G-invariance condition, Yang-Mills theory with torsion on R x G/H is reduced to Newtonian mechanics of a particle moving in R^6, R^4 or R^2 under the influence of an inverted double-well-type potential for the cases G/H = SU(3)/U(1)xU(1), Sp(2)/Sp(1)xU(1) or G_2/SU(3), respectively. We analyze all critical points and present analytical and numerical kink- and bounce-type solutions, which yield G-invariant instanton configurations on those cosets. Periodic solutions on S^1 x G/H and dyons on iR x G/H are also given.Comment: 1+26 pages, 14 figures, 6 miniplot

Cytokine Level Changes in Schizophrenia Patients with and without Metabolic Syndrome Treated with Atypical Antipsychotics

The present study aims at comparing the change in cytokine levels in schizophrenia patients treated with atypical antipsychotics, with or without metabolic syndrome (MetS). The study included 101 patients with schizophrenia, 38 with and 63 without MetS, who received risperidone, quetiapine, olanzapine or aripiprazole for six weeks. We analyzed the concentration of 21 cytokines in the serum patients. The treatment with atypical antipsychotics changed some proinflammatory cytokine levels. It led to increased IFN-alpha 2 (p = 0.010), IL-1 alpha (p = 0.024) and IL-7 (p = 0.017) levels in patients with MetS, whereas the same treatment led to decreased levels of IFN-gamma (p = 0.011), IL-1 beta (p = 0.035), IL-12p40 (p = 0.011), IL-17A (p = 0.031), IL-6 (p = 0.043) and TNF-alpha (p = 0.012) in individuals without MetS. Our results demonstrated the effects of atypical antipsychotics on the immune-inflammatory parameters, depending on the metabolic disturbances in schizophrenia patients