The catalytic performance of phosphate-stabilized WO-ZrO compositions in gas-phase glycerol dehydration has been investigated. Results show that varying WO concentrations direct the process towards either acrolein or allyl alcohol formation. Catalysts with low WO content exhibit strong Lewis acid sites (Zr and W), where these metal ions likely function as redox sites, facilitating glycerol hydrogenolysis to produce allyl alcohol.
View Article and Find Full Text PDFA series of silica-based aerogels comprising novel bifunctional chelating ligands was prepared. To produce target aerogels, two aminosilanes, namely (3-aminopropyl)trimethoxysilane (APTMS) and -(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS), were acylated by natural amino acids (()-(+)-2-phenylglycine or -phenylalanine), followed by gelation and supercritical drying (SCD). Lithium tetrachloropalladate was used as the metal ion source to prepare strong complexes of Pd with amino acids covalently bonded to a silica matrix.
View Article and Find Full Text PDFIntroduction: The design of studies aimed at finding the association between the genetic factor and the studied feature (disease) involves a comparison of the ratio of genotypes or allelic proportions in the study group with those in the control group. At the stage of determining the ratio of genotypes of the studied polymorphisms in the reference group, researchers meet a number of problems, which are the subject of the present work. Aim of the work is to provide scientific rationale for the feasibility of creating a national information system comprising genetic data of the relatively healthy population of Russia, incorporating its ethnic diversity.
View Article and Find Full Text PDFThe possibility of using TiO -based compositions: individual and sulfated titania, and their composites with carbon nanotubes as catalysts for glycerol oligomerization has been displayed. The effect of modification of TiO with sulfur and carbon nanotubes on acid-base and catalytic characteristics in the glycerol conversion was investigated. The activation of glycerol on the catalysts has been studied using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy.
View Article and Find Full Text PDFA new para-aramid aerogel based on a polymer made by the reaction of terephthaloyl dichloride with 2-(4-aminophenyl)-1H-benzimidazol-5-amine (PABI) is introduced. The aerogel readily bound Pd (+2) ions and was used as a hydrogenation catalyst in some industrially actual reactions. The new material, which did not contain p-phenylenediamine moieties, was prepared in two form factors: bulk samples and spherical pellets of 700-900 μm in diameter.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
June 2022
Fourteen new belousovite-related compounds, AZn(TO)X (A = K, Rb, Cs, Tl, NH; T = S, Se; X = Cl, Br, I) have been prepared via melt and evaporation techniques by reacting AX and ZnTO either at high temperatures or in hot aqueous solutions. They adopt the layered structure of the belousovite archetype, and constitute a morphotropic series. The apophyllite-type layers in these structures undergo different corrugations, most pronounced in the case of CsZn(SO)I.
View Article and Find Full Text PDFThe review presents information on the role of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) (HBV) X gene and the protein it encodes (X protein) in the pathogenesis of viral hepatitis B. The evolution of HBV from primordial to the modern version of hepadnaviruses (Hepadnaviridae), is outlined as a process that began about 407 million years ago and continues to the present. The results of scientific works of foreign researchers on the variety of the influence of X protein on the infectious process and its role in the mechanisms of carcinogenesis are summarized.
View Article and Find Full Text PDFIt has been shown that yttria-stabilized zirconia is an effective catalyst for ethanol to -butanol Guerbet coupling. The variation of the calcination temperature allows an improvement in the catalytic characteristics of this material via stabilization of the tetragonal phase of zirconia, having higher basicity than the monoclinic one. The treatment of yttria-stabilized zirconia at an optimal calcination temperature of 500 °C induces the increase in surface basicity required for the aldol condensation step, along with a decrease in surface acidity, which is responsible for the side reaction such as ethylene formation.
View Article and Find Full Text PDFThe nature of active acid sites of zeolite H-BEA with different Si/Al ratios (15-407) in liquid phase etherification of isobutylene with ethanol in a continuous flow reactor in the temperature range 80-180 °C has been explored. We describe and discuss data concerning the strength and concentration of acid sites of H-BEA obtained by techniques of stepwise (quasi-equilibrium) thermal desorption of ammonia, X-ray diffraction, low-temperature adsorption of nitrogen, FTIR spectroscopy of adsorbed pyridine and solid-state Al MAS NMR. The average values of the adsorption energy of NH on H-BEA were experimentally determined as 63.
View Article and Find Full Text PDFAllabogdanite, (Fe,Ni)P, is the only known natural high-pressure phase reported in the Fe-Ni-P system. The mineral, which was previously described from a single meteorite, the Onello iron, is now discovered in the Santa Catharina and Barbianello nickel-rich ataxites. The occurrence of allabogdanite in Santa Catharina, one of the largest and well-studied meteorites, suggests that this mineral is more common than was believed.
View Article and Find Full Text PDFThe structural-phase transformations induced by air annealing of SiO x and SiO x < Er,F > films were studied by the combined use of infrared spectroscopy and ellipsometry. The films were prepared using vacuum evaporation of SiO powder and co-evaporation of SiO and ErF3 powders. The annealing took place at moderate temperatures (750 and 1000 °C).
View Article and Find Full Text PDFThis article describes the assessment of psychological status and quality of life in 41 patients with temporomandibular joint (TMJ) dysfunction as well as the importance of the disease for patients. The study revealed a number of personal characteristics and emotional problems in TMJ dysfunction patients, such as increased anxiety and low level of psychological stability.
View Article and Find Full Text PDFMaresins are produced by macrophages from docosahexaenoic acid (DHA) and exert potent proresolving and tissue homeostatic actions. Maresin 1 (MaR1; 7R,14S-dihydroxy-docosa-4Z,8E,10E,12Z,16Z,19Z-hexaenoic acid) is the first identified maresin. Here, we investigate formation, stereochemistry, and precursor role of 13,14-epoxy-docosahexaenoic acid, an intermediate in MaR1 biosynthesis.
View Article and Find Full Text PDFZh Nevrol Psikhiatr Im S S Korsakova
April 2006
The efficacy of a 7-day switch therapy with parenteral cefuroxime in a dose of 750 mg for 3-5 days followed by the use of oral cefuroxime axetil in a dose of 500 mg every 12 hours was compared with that of a 7-day therapy with parenteral cefuroxime in a dose of 750 mg every 8 hours in hospitalized patients with community-acquired pneumonia. The clinical and bacteriological efficacies and pharmacokinetic properties of both the dosage forms were estimated. It was shown that the clinical and bacteriological effects did not significantly differ in the patients under the parenteral regimen with cefuroxime and under the parenteral-to-oral regimen with cefuroxime and cefuroxime axetil: the cure in 75 and 83 per cent of the patients and the bacteriological response in 100 and 86 per cent of the cases respectively.
View Article and Find Full Text PDFFifteen patients with severe hospital infections such as postoperative pneumonia or intraabdominal sepsis were treated with ofloxacin in a dose of 400 mg once a day for 7 to 14 days (11 days at the average). The drug was administered intravenously for the first 3-5 days and then orally till the end of the treatment course. The clinical effect was observed in 14 patients (93 per cent) and the positive bacteriological effect was stated in 11 out of 13 patients (85 per cent).
View Article and Find Full Text PDFExperiments used 409 male CBA mice to study the effect of ascorbic acid on carcinogenesis induced by treatment with such precursors of nitroso compounds as sodium nitrite and morpholine. The former was given with feed in a total dose of 573-891 mg/animal and the latter--with drinking water in a total dose of 138-183 mg/animal. As a result, the total number of tumor-bearers grew from 63.
View Article and Find Full Text PDFA study involving the use of acidity test of gastric secretion in healthy population living in the four areas of the Kalmyk ASSR characterized by different natural conditions and different rates of stomach cancer incidence established a correlation between a higher frequency of this disease, on the one hand, and enhanced rates of anacidity as well as higher salinity of soil and water, on the other.
View Article and Find Full Text PDFVolatile nitrogen bases in soil have been analysed by gas chromatography. Two samples of soils taken from different regions have been investigated. The first sample was loam.
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