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Coronavirus disease 2019 is a serious disease that causes acute respiratory syndrome and negatively affects the central nervous system. SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) crosses the blood-brain barrier due to the S protein on the surface of the viral particles. Thus, it is important to develop compounds that not only have an inhibitory effect but are also capable of completely deactivating the S-protein function. This study describes the purposeful modification of porphyrins and proposes compounds, asymmetrically hetaryl-substituted porphyrins with benzothiazole, benzoxazole, and N-methylbenzimidazole residues, to deactivate the S-protein functions. Molecular docking of SARS-CoV-2 proteins with hetaryl-substituted porphyrins showed that the viral proteins S-, N-, and nsp13 exhibited the highest binding affinity. Hetaryl-substituted porphyrins form strong complexes (13–14 kcal/mol) with the receptor-binding domain of the S protein, while the distance from the porphyrins to the receptor-binding motif (RBM) does not exceed 20 Å; therefore, RBM can be oxidized by 1O2, which is generated by porphyrin. Hetaryl-substituted porphyrins interact with the nucleocapsid protein in the serine/arginine-rich region, and a number of vulnerable amino acid residues are located in the photooxidation zone. This damage complicates the packaging of viral RNA into new virions. High-energy binding of hetaryl-substituted porphyrins with the N- and C-terminal domains of nsp13 was observed. This binding blocks the action of nsp13 as an enzyme of exoribonuclease and methyltransferase, thereby preventing RNA replication and processing. A procedure for the synthesis of hetaryl-substituted porphyrins was developed, new compounds were obtained, their structures were identified, and their photocatalytic properties were studied., Graphical abstract Image 1

The chemical precipitation was used to obtain carbon fibers (CF) with surface modified by magnetite particles (Fe3O4). Processing was carried out by employing up to three subsequent coating stages ...

The effect of the content of silicon carbide whiskers and the sintering temperature on the physicomechanical and thermophysical properties of samples of a ceramic composite material (CCM) of the SiC–SiCw–B4C–AlN system with weight content of silicon carbide whiskers (SiCw) 10, 30, and 50%, obtained by spark plasma sintering. Introducing silicon carbide whiskers SiCw into CCM of the SiC–B4C–AlN system increased the bending strength and crack resistance, and at SiCw weight content 30 and 50% the strength and crack resistance of the CCM were at the same level.

Coatings based on the system Y2O3–Al2O3–SiO2 are promising for protecting silicon carbide based materials from the effects of an oxidizing atmosphere, water vapor, and salt vapors. The interaction of Y2O3–Al2O3–SiO2 coatings, obtained by the sol-gel method, with water vapor and Na2SO4 salt was investigated. Coatings based on the yttrium aluminosilicate system were found to have good oxidative and chemical resistance to water vapor and Na2SO4 salt at temperatures 1300 – 1450°C. The weight gain for the coated samples tested in Na2SO4 salt vapor did not exceed 1%. The initial SiC substrates are characterized by active oxidation processes with weight reduction from 8 to 11%.

Due to the fact that cardiovascular diseases (CVD) are the leading cause of death worldwide, reducing risk factors and maintaining a healthy lifestyle play an important role in primary and secondary prevention of CVD development and improving prognosis. The purpose of the study. To study the eff ectiveness of carbon dioxide baths and water training in the primary prevention program for people with CVD risk factors. Material and methods. 60 patients (43 women and 17 men) with CVD risk factors were examined before and after a course of carbon dioxide baths and aquatic therapy. The hardware and software complex «Physiocontrol-R» was used. It includes, in addition to psychological testing (Spielberger, SAN, Lüscher tests, сardiointervalography (CIG) for the study of the autonomic regulation of the cardiovascular system, the study of the state of central and peripheral hemodynamics, Bioelectrical impedance analysis (BIA) for the study of body composition. Results. In the group of patients who took a complex of carbon dioxide baths and water training, in contrast to the control group, there was an improvement in the clinical condition, hemodynamic parameters, normalization of sympathicovagal balance and body composition. Conclusion. The aquatic therapy program in the pool and the use of HCV led to an improvement in the patients ‘ psychoemotional state, improvement of central and peripheral hemodynamics, and sympathico-vagal balance, which is associated with a reduced risk of developing CVD.

Due to the emergence of a new coronavirus infection COVID-19, scientists around the world are actively working on a vaccine against the SARS-CoV-2 coronavirus. At the same time, it is possible that existing medications can help in the fight against this disease. The local antiseptic drug benzidamine hydrochloride in the early stages of illness can prevent the virus from entering the lower respiratory tract and potentially reduce the severe illness associated with pneumonia and, as a result, reduce COVID19-related hospitalizations, which can significantly reduce the burden on the health care system.The aim: to evaluate the antiviral activity of benzidamine hydrochloride against SARS-CoV-2 in vitro.Material and methods. Antiviral properties of benzidamine hydrochloride were studied in vitro in non-toxic concentrations on monolayer of Vero-E6 cells infected with pandemic strain of SARS-CoV-2 coronavirus in treatment and prophylactic scheme of the compound and virus administration.Results. Benzidamine hydrochloride has antiviral activity (15,0 mcg/ml), the efficiency of its antiviral action is directly proportional to the concentration of the substance.Conclusions. Taking into account very limited range of antiviral drugs with direct action on SARS-CoV-2 virus, the studied preparation can be used in complex therapy at early stages of the disease, which can prevent virus penetration into lower respiratory tract and potentially reduce the number of complications.

The purpose of this study was reconstruction of dominant paleo-environments on northern and southern slopes of Alborz Mountain based on the modern and old environmental evidences preserved in the soils. Totally 691 soil profiles in 14 separate segments (9 segments in northern slope and 5 segments in southern slope) with an area of 783,850 ha (251 pedons in northern slope with about 123,600 ha; 440 pedons in southern slope with about 660,350 ha) in Alborz Mountains were studied. Morphological, physical, chemical, mineralogical, micromorphological, and geochemical analyses of the studied sites carried out using standard methods and demonstrated significant differences between the soils of northern and southern slopes. Micromorphological data showed that the calcite coatings in northern slope pedons have formed before the clay coatings however, while the opposite conditionings for calcite and clay coatings in southern slope were observed. The geochemical analyses results were in agreement with the results obtained from micromorphological analyses and further confirmed the addition of aeolian materials into the studied pedons in southern slope. Biological features and the organic and inorganic residues were extremely different in the northern and southern slopes. The maximum and minimum mean residence times (MRTs) in the subsurface layers were 4467 ± 50 years in deciduous forest and 4410 ± 48 years in coniferous forest in northern slope. However, the MRTs for burnt woods from the depths of 1.6 and 2.68 m of soil in southern slope were 3665 ± 61 and 6083 ± 84 years, respectively. Soils as archives of ecosystems contain very informative data for paleo-environmental and paleogeographic reconstructions. The results of this study demonstrated that the southern slope has been heavily influenced by glacial and aeolian deposits that in some cases have led to the top-down reverse distribution of the element oxides in the soil.

Novel porphyrin compounds containing benzothiazole, benzoxazole, and benzimidazole moieties have been prepared and their structures have been confirmed. Molecular docking of non-symmetric hetaryl-substituted porphyrins and chlorin e6 with SARS-CoV-2 helicase has been carried out. The affinity of hetaryl-substituted porphyrins to this protein has been found significantly higher than that of the drugs approved by the FDA and chlorin e6. The structure of the complexes of SARS-CoV-2 helicase with the considered macroheterocyclic compounds has been analyzed. Possible ways to inhibit and photoinactivate SARS-CoV helicase have been suggested basing on the localization of porphyrins and chlorin e6 in the helicase domains.

Abstract— The possible nitrogen sources for Osc. trichoides DG6, a typical strain of the Oscillochloridaceae family, are ammonium, N2, glutamate, asparagine, glycine, and glutamine. The assimilation of molecular nitrogen occurs with the participation of nitrogenase, the structural gene of which, nifH, is located in the gene cluster which also includes the genes of the nifD and nifK nitrogenase subunits and the auxiliary nifB gene. Considering that nifHBDK clusters have been also annotated in the genomes of other members of the Oscillochloridaceae family, including uncultured and candidate taxa, it can be assumed that the ability to fix nitrogen is a property immanent for this entire family. The pathways for assimilating ammonium in the cells grown using different nitrogen sources may differ. Osc. trichoides DG6 growing in a medium containing ammonium assimilated it with the participation of glutamate dehydrogenase, which is determined by a single gene. The expression product of this gene has dual functionality and can be used to implement the reaction with both NAD and NADP. With the growth of Osc. trichoides DG6 on a medium with glutamate as the only nitrogen source all the enzymes necessary for the implementation of the GS‑GOGAT pathway were found in the cells. However, for the glutamine synthetase reaction, ammonium, which was absent in the growth medium, was required. The source of ammonium may be glutamate metabolized through glutamate dehydrogenase.

We have studied structural and phase transformations of precursors to high-temperature coatings based on yttrium silicate and yttrium aluminosilicate systems and identified general trends in the influence of an oxidizing atmosphere on the heat resistance of coatings produced by slip casting/firing and atmospheric plasma spraying on silicon carbide composite materials at temperatures of up to 1500°C.

Composites of polycaprolactone with cellulose nanocrystals were produced, and their morphological, thermal, and strength characteristics were examined. It was found that nanocrystalline cellulose as a filler increased the porosity of the resultant composite materials. A conclusion was made that nanocrystalline cellulose can act as an initiator of polycaprolactone crystallization and affect the growth of the polymer crystallites. Incorporation of cellulose nanocrystals into the polycaprolactone matrix increased the hydrophilicity of the material and promoted an increase in water sorption while making the composite more brittle as indicated by decrease in the elongation at break and icreases in the tensile strength and Young’s modulus.

Acid–base membranes have been prepared by mixing a 1-vinyl-1,2,4-triazole polymer (PVT) with phenol-2,4-disulfonic acid (PDSA) in the presence of products of intermolecular crosslinking of polyvinyl alcohol and oxalic acid. The composition and structure of the membranes have been studied by elemental analysis and IR and NMR spectroscopy techniques. The membranes are thermally stable up to 245°C. Their electrical conductivity increases from 6.23 mS cm−1 (PVT–PDSA 80 : 20 wt % membrane) to 59.8 mS cm−1 (PVT–PDSA 10 : 90 wt %) with increasing temperature and phenol-2,4-disulfonic acid content at a temperature of 80°C and a humidity of 75%. The activation energy of the membranes ranges from 19.5 to 38.2 kJ/mol, respectively. The water uptake of membranes, which determines, among other things, the electrical conductivity, depends on the PVT content: the water uptake decreases from 200 to 50% with an increase in its amount in the membrane composition from 9.1 to 81.30 mol %, leading to a decrease in electrical conductivity along with a decrease in the proportion of PDSA.

Composite materials that contain tetracationic hydrotalcite-like layered double hydroxide and a cobalt-iron spinel phase were prepared by coprecipitation from a solution of a mixture of magnesium, aluminum, cobalt(II), and iron(III) salts followed by hydrothermal treatment. The iron and cobalt contents in the samples were varied within a broad range. The thermal transformations of the prepared composites were examined by high-temperature X-ray diffraction, and the layered hydroxide phase was found to remain when heated up to 300°C. The specific magnetization and magnetic susceptibility of the materials were determined using a vibrating sample magnetometer; a rise in the iron and cobalt contents was found to increase the magnetization up to a certain limit. The obtained samples can be used as magnetic sorbents. The sorption capacity of materials was estimated using Congo red anionic dye as an example.

It is an urgent task today to seek and implement nature-like technologies in broiler production and obtain biologically complete and safe poultry products, thus refusing from antibiotic use in feed. Feed additives based on natural components can be an effective tool for implementation of preventive and therapeutic veterinary measures. The paper presents research study results of application of betulin-based phytobiotics in broiler farming. The tests were carried out on Ross-308 cross-breed broiler chickens within the production cycle at one of the poultry farms of the Sverdlovsk Oblast. Birds of the experimental group received compound feed supplemented with dry betulin at 2.5 mg/kg of live weight from day 21 to day 35 of growing. The introduction of betulin-based feed additive into the diet contributed to increase in live weight gain and 7.6% pectoralis muscle output as compared with the control group. It was established that the phytobiotic consumption resulted in reduced deposition of subcutaneous and abdominal fat, higher biological value of meat by increasing the ash content, improved technological properties of meat due to increasing water-holding capacity of muscle fiber and intensity of formation and maturation of muscle fiber. Histological studies of pancreatic tissue samples from broiler chickens showed increase in the mass of islets of Langerhans and insulin-producing cell complexes. The pancreas was activated due to effects of the betulin-based feed additive. The results obtained indicate that the use of betulin in broiler production is a promising trend.

The rheological properties of dilute and moderately concentrated solutions of methyl cellulose–chitosan blends in aqueous solutions of acetic and succinic acids are studied. Using dynamic mechanical, thermogravimetric, and X-ray diffraction analyses, the structural organization of composite films is investigated, the temperatures of relaxation transitions are determined, and the composition regions in which the polymers are miscible and form mixed structures are estimated.

The cyclic voltammetry method was used for studying the electrochemical oxidation of benzene, diphenyl and p-terphenyl in ionic liquid N-butylpyridinium chloride–AlCl3 (1 : 1.5) at 30°C. Comparative analysis of peaks obtained for each initial monomer was performed. The assumptions on the differences in the mechanisms of electrochemical synthesis of polyphenylenes in the ionic liquid from benzene, diphenyl and p-terphenyl were made.

Bottlebrush macromolecules can be regarded as molecular tensile machines, where tension is self-generated along the backbone due to steric repulsion between densely grafted side chains. This intrinsic tension is amplified upon adsorption of bottlebrush molecules onto a substrate and increases with grafting density, side chain length, and strength of adhesion to the substrate. To investigate the effects of tension on the electronic structure of polythiophene (PT), bottlebrush macromolecules were prepared by grafting poly(n-butyl acrylate) (PBA) side chains from PT macroinitiators by atom transfer radical polymerization (ATRP). The fluorescence spectra of submonolayers of PT bottlebrushes were measured on a Langmuir–Blodgett (LB) trough with the backbone tension adjusted by controlling the side-chain length, surface pressure, and chemical composition of a substrate. The wavelength of maximum emission has initially red-shifted, followed by a blue-shift as the backbone tension increases from 0 to 2.5 nN, whic...

The interaction of meso-tetra-([Formula: see text]-methyl-3-pyridyl)bacteriochlorin tetra 4-methylbenzenesulfonate, meso-tetra-([Formula: see text]-methyl-4-pyridyl)porphine tetraiodide and meso-tetra-([Formula: see text]-methyl-3-pyridyl)porphine tetraiodide with protein was studied. The localization of macrocycles in the protein and their influence on the processes of protein aggregation were established. The aggregation process is initiated by the transition of alpha structures into beta folds, caused by the binding of porphyrins at the sites of protein IB and IIA. The complexes were irradiated with blue and green light. The data obtained showed that by varying the intensity of the light exposure, one can influence the shift of the aggregation equilibrium, obtaining predominantly monomeric or aggregated structures. Thus, photoexposure can be used as an alternative method of treating diseases caused by amyloidosis and for regulating the state of the protein in the pharmacological preparations.

In this study, the oxidative destruction of bromophenol blue dye with hydrogen peroxide was carried out at pH 4.0-4.1 in the presence of a commercial horseradish peroxidase, as well as peroxidase isolated directly from horseradish roots (Armoracia rusticana). To determine peroxidase activity, a model reaction of the oxidation of phenol to quinone was used. With a dye concentration of 32.7 μM, the optimal concentration of hydrogen peroxide was 0.04 mM at peroxidase concentration of 1.15 nM. The optimal temperature of the enzymatic reaction was determined: at 23 °С for 10 min 90% of the dye was exposed to destruction. When the temperature rises to 50 °С, the reaction rate decreases, and the degree of destruction is 56% for the same time interval. It was shown that the initial rate of peroxidase oxidation of bromophenol blue follows Michaelis-Menten equation. The kinetic parameters of the enzymatic reaction were determined by linearizing Michaelis-Menten equation in Lineweaver-Burk coordinates. It was found that for the peroxidase oxidation reaction of bromophenol blue Michaelis constant and maximum rate were 42.7 μM and 57.5 μM·min–1, respectively. In this work, а high percentage of dye degradation was also achieved when using peroxidase isolated from horseradish roots. The experiments were conducted at a temperature of 30оС and pH 4.1. With the increase in the volume of the extract from 0.1 to 0.2 ml, the percentage decolorization increases from 75% to 90%. The results demonstrate the high degradation efficiency of bromophenol blue with the participation of the commercial horseradish peroxidase and peroxidase isolated from horseradish roots. Enzymatic oxidative degradation can be considered as an alternative to biodegradation.

In water–DMF at DMF content less than 2.6 mol dm−3, deuteroporphyrin IX dimethyl ester forms both H- and J-aggregates. The J-aggregates are detected as a single type of associated species after binding of the porphyrin with BSA on the surface of the protein IB subdomain.

The possibility of obtaining graphite-like structures from chitosan by microwave processing was studied. A comparative analysis of the products of pyrolysis and microwave treatment of chitosan was carried out.

The effects of the osmoregulators D-sorbitol and D-mannitol in Asparkam-L solution for infusion on diuresis and urinary K+ and Mg2+ excretion were studied in white mongrel rats. Animals received single i.v. doses of samples of the formulation Asparkam-L: 1) with osmoregulator D-sorbitol; 2) with osmoregulator D-mannitol, 3) without osmoregulator, at the recommended one-time dose (1ROTD, calculated from the dose of 10 ml for a human with the average body weight of 70 kg) and at doses 2, 4, and 6 times greater than 1ROTD. Use of all study doses produced a background of minor oscillations in diuresis, with the smallest levels of urinary K+ and Mg2+ excretion with sample 1 and the largest with sample 2. Levels of K+ and Mg2+ excretion in rats given sample 2 were statistically significantly greater than those in control animals given 0.89% NaCl at a volume equivalent to that of 6 ROTD. Increased K+ and Mg2+ excretion after use of sample 2 probably indicated lower efficacy and the inadvisability of using mannitol as osmoregulator in the formulation intended to make up for deficit of these cations.

Background. Previously, we have shown that the polyhexamethylene guanidine hydrochloride hydrogel exhibits a pronounced wound healing. At the same time, no studies of the toxic effect of the hydrogel on animals have been conducted. Aim of the research. In the framework of this work, the acute toxicity of the hydrogel polyhexamethylene guanidine hydrochloride was studied in laboratory animals with intragastric administration. Materials and methods. The polyhexamethylene guanidine hydrochloride hydrogel was obtained by crosslinking the amino end groups with formaldehyde. An acute toxicity study was carried out (P 1.2.3156-13, GOST 32644-2014 and the Guidelines for conducting preclinical studies of drugs) in an experiment on outbred mice with a single addition of the test substance in different doses (1000, 3000, 5000, 8000 mg/kg) with fixing indicators (appearance, behavior, condition of the body hair coat, water and food consumption, excretion, body weight and its growth) during 14 days. After the animals were withdrawn from the experiment, autopsy, macroscopic evaluation and weighing of the internal organs were performed. The results showed that with the introduction of the test substance into the animal organism, death during the observation period (14 days) did not occur. It was not possible to determine the semi-lethal dose for the test compound. Conclusion. The conducted studies allow us to conclude that this substance is practically non-toxic and can be classified as hazard class V. Further research will be directed to the formation of hydrogel compositions with medicinal substances.

N-Nitrosodimethylamine (NDMA) is a highly hepatotoxic compound and classified as group 2A according to IARC, which is probably carcinogenic to humans. The habit of consumption of grilled meat-based foods may lead to a health risk, especially in children. In this study, a food consumption survey was conducted in 4 districts (2 in urban and 2 in suburban areas) in Hanoi, Vietnam. Food samples in the diet of children from 6 to 36 months was collected and tested for NDMA by GC-MS/MS method. Total exposure dose was calculated and compared to the proposed tolerable daily intake (TDI) to characterize the risk. Among the food tested, NDMA was detected in canned puree, grilled meat and sausage. The average contents of NDMA were 1.50 μg/kg, 1.18 μg/kg and 0.20 μg/kg in grilled meat, sausage and puree, respectively. The average total daily exposure dose of NDMA was 8.23 ng/kg bw/day in all studied group, which were within the upper recommended TDI (9.3 ng/kg bw/day). With a certain assumption, the cancer risk caused by exposure to NDMA were higher than the recommended value of WHO.

Introduction. salivary diagnostics is a promising area that requires further research. The aim of the study. The two-stage study is aimed at identifying reliable biochemical and immunological markers of the influence of atmospheric air pollution in saliva samples in preschool children. Material and methods. Mixed saliva samples were taken from 112 children aged 5-7 years in 6 kindergartens located at distances of 1.7-5.9 km from the complex of agricultural processing enterprises. At the screening stage, the intensity of luminol-dependent chemiluminescence (LC), levels of secretory IgA (sIgA), IL-8, uric acid, activities of α-amylase, and lysosomal enzyme N-acetyl-β-d-glucosaminidase (NAG) were determined in saliva samples; at the post-screening stage, IL-1b and IL-6 were added. Results. In children at the screening stage only those markers that can be considered as indirect signs of phagocyte activation were associated with exposure levels to industrial zone emissions by significant equations: CL (y=6.98-0.17 x; p=7.2*10 -9 ); IL-8 (y=776.2-83.2 x; p=3*10 -4 ); NAG (y=13.94-0.93 x; p=0.037). To check whether this coincidence is random, we selected two additional markers in the form of functional “fork”: IL-1β (leukocyte pyrogen) and IL-6 (cofactor of B-lymphocyte differentiation). Methods of regression, correlation, and cluster analysis confirmed all 4 “phagocytic” markers significantly to increase along the gradient of industrial emissions and form a single cluster, cross-linked with significant correlation coefficients. IL-6 saliva content was associated with exposure levels by a rise-fall relationship, and, contrary to conventional beliefs, had no connection with sIgA content. The last finding may be related to the lack of ability of IL-6 and defensins to induce sIgA in mice [Boyaka et al., 2001]. Conclusion. The survey results suppose that emission gradient from the industrial zone contains PM and does not contain haptens or immunotoxic compounds. Post-screening can be a useful technique when using saliva samples as insufficiently studied objects.

Cardiovascular calcification (CVC) makes a significant contribution to the manifestation of cardiovascular complications in patients with chronic kidney disease. Early CVC markers are currently being actively studied to optimize cardio-renoprotective strategies. We performed a prospective comparative analysis of the following factors: FGF-23, a-Klotho, sclecrostin, phosphate, parathyroid hormone, the estimated glomerular filtration rate (eGFR), central systolic pressure as an independent determinant of CVC.The study included 131 patients with chronic kidney disease 25D st. Serum levels of FGF-23, Klotho, and sclerostin were evaluated using the ELISA method. Vascular augmentation (stiffness) indices, central arterial pressure (using the SphygmoCor device), calcification of heart valves and the degree of aortic calcification (aortic radiography) were also investigated. The observation period was 2 years.According to the Spearman correlation analysis, the percent of calcification increase and the change in Klotho level are most related. According to ROC analysis, a decrease in serum levels of Klotho by 50 units or more is a significant predictor of an increase in aortic calcification of 50% or more with a sensitivity of 86% and a specificity of 77%. Using logistic regression analysis, it was found that a serum Klotho level 632 pg/L predicts an eGFR below a median level of 48 ml/min/1.73 m2 with a sensitivity of 85.5% and a specificity of 78.5%. Wherein OR 17.477 (CI 95% 8.04637.962; p0.001).The factor most associated with CVC is Klotho. Decreased serum level of Klotho is a predictor of aortic calcification. In addition, the initial serum level of Klotho is a predictor of eGFR after 2 years.Кардиоваскулярная кальцификация (КВК) вносит существенный вклад в проявление сердечно-сосудистых осложнений у больных хронической болезнью почек (ХБП). Цель. Изучить ранние маркеры КВК с целью оптимизации кардиоренопротективной стратегии. Проведен проспективный сравнительный анализ следующих факторов: фактора роста фибробластов 23, a-Klotho, склеростина, фосфата, паратиреоидного гормона, расчетной скорости клубочковой фильтрации (рСКФ), центрального систолического давления как независимых детерминант КВК. Материалы и методы. В исследование включен 131 пациент с ХБП 25D стадий. Сывороточные уровни FGF-23, Klotho и склеростина оценивались с помощью ELISA-метода. Исследованы также индексы аугментации (жесткости) сосудов, центральное артериальное давление (с помощью прибора SphygmoCor), кальцификация клапанов сердца и степень кальциноза аорты (рентгенография аорты). Период наблюдения составил 2 года. Результаты. Согласно корреляционному анализу Спирмена в наибольшей степени связаны процент повышения кальцификации и изменение уровня Klotho. Согласно ROC-анализу снижение сывороточного уровня Klotho на 50 ЕД и более является существенным предиктором увеличения кальцификации аорты на 50% и более с чувствительностью 86% и специфичностью 77%. С помощью логистического регрессионного анализа выявлено, что сывороточный уровень Klotho ниже 632 пг/л предсказывает рСКФ ниже медианного уровня 48 мл/мин/1,73 м2 с чувствительностью 85,5% и специфичностью 78,5%. При этом OШ 17,477 (ДИ 95% 8,04637,962; p0,001). Заключение. Фактором, наиболее ассоциированным с КВК, является Klotho. Снижение сывороточного уровня Klotho предиктор аортальной кальцификации. Кроме того, исходный сывороточный уровень Klotho является предиктором рСКФ через 2 года.

A number of tetrametallic layered double hydroxides containing magnesium and cobalt on the site of doubly charged cations in the structure of brucite-like layers and aluminum and iron on the site of triply charged cations have been synthesized using three distinct methods: coprecipitation, microwave synthesis, and hydrothermal crystallization. A sodium hydroxide solution was used as a precipitant. The results demonstrate that all three methods yield a well-crystallized hydrotalcite-like layered hydroxide and an impurity phase. We believe that it is the impurity phase which is responsible for the magnetism of the materials. Most likely, this phase is spinel CoFe2O4.

New hybrid proton conducting membranes based on sulfonated copolymers of styrene and allyl glycidyl ether using tetraethyl orthosilicate were syntheses. The composition and structure of the copolymers and membranes has been proven by elemental analysis, IR and NMR spectroscopy. Based on quantum chemical calculations a sulfonation mechanism of copolymers was proposed. The characteristics of membranes were evaluated by thermal analysis, dynamic mechanical analysis, electrochemical impedance spectroscopy, water uptake, swelling and ion exchange capacity tests. The hybrid membranes are characterized by high proton conductivity of 4.21 10−2 S cm−1 (70 °C, 75% RH), activation energy of proton transport (24.5 kJ mol−1), ion-exchange capacity (2.1 mmol g−1), and thermal stability up to 260°С. The hybrid membranes showed water uptake of 6 and 51% at 30 °C and 100 °C, respectively. The suitability of the hybrid membranes toward fuel cell applications was tested through a single cell analysis.

We have demonstrated that SiC mesastructures with gently sloping sidewalls form with the help of selective reactive ion etching (RIE) of silicon carbide through a photoresist mask (slanted walls are formed during simultaneous etching of SiC and the resistive mask with the edge in the shape of a sharp wedge). A simple geometrical model of etching predicts that the resultant slope of the mesastructure wall must be specified by two parameters, i.e., initial angle of the resistive wedge and the selectivity of SiC etching relative to the photoresist (ratio of etching rates of SiC and photoresist). For experiments, we used polished 4H–SiC wafers with the (0001) orientation. Photoresist regions with an edge angle of 22° were deposited using photolithography onto the Si side of the wafers. Then etching of mesastructures was performed in nitrogen trifluoride in a setup with an inductively coupled plasma. We selected RIE parameters ensuring SiC and photoresist etching with rates of 55 and 160 nm/min, respectively (etching selectivity was 1 : 3). The SiC mesastructures formed by etching have a height of 3.2 μm and gently sloping sidewalls with a slope of about 8°. This technology can be used for preparing high-voltage SiC devices with a straight bevel.

The process of thermocatalytic conversion of polypropylene into liquid hydrocarbons using amorphous aluminum silicates with aluminum content of 1.6-12.9 wt.% as catalysts was studied. The aluminum silicates were synthesized by sol-gel method using hydrolysis of tetraethoxysilane in a presence of aluminum salt at pH=9. All samples possessed acidic sites with pKa value of 3.46-5.00 and had a developed surface. Textural properties of the aluminum silicates were determined. Thermocatalytic conversion of polypropylene was carried out in a flow fixed-bed reactor with a fixed layer of the mixture of the catalyst and the reagent at a mass ratio of polymer : catalyst of 3 : 1 in argon atmosphere with a gradual rise of temperature in the range of 300 – 450 ºС. The sample of silica, which did not contain aluminum, was demonstrated to be inactive in polypropylene degradation, while other catalysts provided conversion of polypropylene into liquid products. The highest yield of liquid products was 80% for a catalyst with an aluminum content of 8.1 wt.%. According to the results of GLC saturated hydrocarbons were identified among the products for all samples. The effect of the concentration of acidic centers on the chemical and fractional composition of the target products was shown. For the studied aluminum silicates with the same pKa values, an increase in the aluminum content favored the formation of a lighter hydrocarbon fraction. For the catalyst with the highest aluminum content the n-alkanes of С5-С10 composition were identified. These products were closest to gasoline oil fraction. This provides a possibility to consider secondary polyolefins as an alternative source of motor fuels. An influence of catalyst composition on maximal temperature of polyethylene degradation was determined by differential thermal analysis.

To understand the effect of the doping amount of Cu2+ on the structure and reactivity of SnO2 in NOx-SCR with NH3, a series of Sn-Cu-O binary oxide catalysts with different Sn/Cu ratios have been prepared and thoroughly characterized. Using the XRD extrapolation method, the SnO2 lattice capacity for Cu2+ cations is determined at 0.10 g CuO per g of SnO2, equaling a Sn/Cu molar ratio of 84/16. Therefore, in a tetragonal rutile SnO2 lattice, only a maximum of 16% of the Sn4+ cations can be replaced by Cu2+ to form a stable solid solution structure. If the Cu content is higher, CuO will form on the catalyst surface, which has a negative effect on the reaction performance. For samples in a pure solid solution phase, the number of surface defects increase with increasing Cu content until it reaches the lattice capacity, as confirmed by Raman spectroscopy. As a result, the amounts of both active oxygen species and acidic sites on the surface, which critically determine the reaction performance, also increase and reach the maximum level for the catalyst with a Cu content close to the lattice capacity. A distinct lattice capacity threshold effect on the structure and reactivity of Sn-Cu binary oxide catalysts has been observed. A Sn-Cu catalyst with the best reaction performance can be obtained by doping the SnO2 matrix with the lattice capacity amount of Cu2+.

The use of mechanochemical activation of the powder at the stage of mixing the components and consolidation by spark plasma sintering made it possible to synthesize material based on silicon carbide, which has a weight loss of less than 0.04% when tested for heat resistance at 1500°C for 100 h. A ceramic material was produced at a consolidation temperature of 1800°C, its hardness was 32 GPa and a critical stress intensity factor was 6 MPa m1/2.

The aim of this study was to obtain new water-soluble polyguanidines, assess their antimicrobial properties with respect to the test objects of Escherichia coli and Bacillus cereus and establish the hazard class regulated in the territory of the Russian Federation. Polymers obtained in high yields by the method of polycondensation in the melt of the corresponding monomers and characterized by the methods of IR spectroscopy and elemental analysis. Serial dilution–agar plate procedure was performed in order to estimate antibacterial effects. The biocidal properties of the samples were estimated by the percentage reduction of microorganisms (% reduction). To determine the acute toxicity, a toxicometric assessment and symptoms of intoxication upon oral administration of a single dose were carried out in laboratory animals. New water-soluble guanidine-containing polymers with a number average molecular weight of 660–1040 Da were obtained. Copolymers with a low degree of substitution (10–20%) exhibit high antimicrobial activity among N-phenyl-substituted samples. As a result of the substituent increase in the polymer chain, their activity in relation to the studied bacteria is linearly decreased to a level comparable to the test sample. In contrast to the N-octyl-substituted copolymers, gram-positive bacterium B. cereus is more susceptible to N-phenyl-substituted samples. Substances after intragastric injection belong to the fourth class of toxicity (LD50 > 300 ≤ 2000 mg/kg) according to the requirements of tabulation of toxicity classes regulated in the territory of the Russian Federation. The combination of low toxicity with a high level of antibacterial activity of new guanidine-containing polymers suggests the possibility of obtaining new effective disinfectants.

To provide new insights into the origin of garnet megacrysts and evolution of kimberlite melts, we studied in detail the polymineralic and monomineralic inclusions and their host garnets from the Grib kimberlite (Arkhangelsk diamond province, Russia). Low-Cr and high-Cr garnet megacrysts and eclogitic garnets contain abundant polymineralic and rare monomineralic inclusions. Monomineralic inclusions presented by clinopyroxene, ilmenite, olivine replaced by serpentine, were found exclusively within the low-Cr megacrysts. The composition of clinopyroxene exhibits geochemical equilibrium with the host garnet, indicating its primary origin during the formation of the megacryst assemblage. The low-Cr garnet–clinopyroxene mineral assemblage formed as a result of high-temperature, melt-associated mantle metasomatism by failed kimberlite within the lithospheric mantle (T = 1150 °C and P = 5.5 GPa). Polymineralic inclusions are characterised by a silicate or silicate-sulphate matrix. The central part of the silicate inclusions is filled by serpentine and contains ilmenite, spinel, perovskite, calcite and apatite. At the contact with host garnets, phlogopite, spinel and amphibole occur as reaction minerals. Composition of spinel and other minerals within inclusions with silicate matrix suggests that kimberlite melt was trapped at mantle pressures. Inclusions with silicate matrix were found in all garnets. The matrix of silicate-sulphate inclusions consists of silicate cryptocrystalline phases and sulphate minerals (celestine–barite) and contains calcite grains. The inclusions are distributed in some low-Cr garnet megacrysts and eclogitic garnet. The silicate-sulphate inclusions were crystallised from the late-stage kimberlite melt. Diverse reaction textures are evidences of disequilibrium between the host crystals and polymineralic inclusions and indicate that garnet and the hosted inclusions reacted with the ascending kimberlite melt. The silicate-sulphate inclusions with a thin rim of epidote within eclogitic garnets indicate that a kimberlite melt invaded the garnet and induced partial melting. The studied inclusions allow us to propose three stages of the Grib kimberlite evolution: 1) generation of garnet megacrysts and primary inclusions due to melt metasomatism, 2) reaction of the high-Ti kimberlite melt with garnet megacrysts (including their dissolution) and 3) alteration of the inclusions in garnet after kimberlite ascent.

Lung disease caused by Pseudomonas aeruginosa is the leading reason for death in cystic fibrosis patients. Therapeutic efficacy of the pharmacological pairs, the naked/encapsulated mutant form of C...

Binary copolymers possessing thermal stability up to 290°C and suitable for the formation of ion-exchange membranes have been obtained by free radical copolymerization of sodium p-styrene sulfonate and 1-vinylimidazole with subsequent conversion to the H-form. The composition and structure of the copolymers are confirmed by elemental analysis and IR and NMR spectroscopy. Multicomponent membranes based on the copolymers of sodium p-styrene sulfonate and 1-vinylimidazole have been obtained using poly(vinyl alcohol) crosslinked by oxalic acid as a film-forming agent. It is shown by scanning electron microscopy that the surface and cut of the membranes have a uniform structure. The specific electric conductivity of the membranes with different concentrations of styrene sulfonic acid (20 to 80 mol % in the copolymer) increases with an increase in the fraction of styrene sulfonic acid and is 29.5 to 52.0 mS cm−1 at 80°C. The activation energy of proton transport of the membranes is 12.5 to 15.5 kJ mol−1. The water uptake of the membranes decreases with the increase in the concentration of the basic (imidazole) component in them, which may be associated with the increase in the density of ionic crosslinking due to the acid–base interaction of the sulfo groups and pyridine nitrogen atoms of the imidazole cycle. The formation of acid–base pairs results in the formation of continuous proton transport channels in addition to the sulfonic acid channels, which is confirmed by the high values of specific electric conductivity even in the case of a decrease in the concentration of sulfostyrene in the composition of the membrane. Increasing the concentration of 1‑vinylimidazole in the composition of the copolymer from 20 to 80 mol % leads to an increase in the relative elongation at break from 3 to 6%, an increase in the tensile strength at break from 4 to 7 MPa, a decrease in the Young modulus of the membranes from 127 to 102 MPa, and a decrease in the water uptake from 45 to 15.

Introduction . At present, despite scientific and technical progress and the introduction of modern safe technologies in production related to dust formation and dust emission, an increased risk of developing dust pathology of the lungs is noted in the machine-building and mining industries. Chronic lung diseases, including occupational diseases, are one of the most urgent problems of modern respiratory medicine and cause a decrease in the quality of life, working capacity and increased mortality of the working population. The features of the course of dusty lung diseases at the early stages of the pathological process are insufficiently studied, and functional and biological markers — criteria for individual prognosis of the patient’s condition-have not been identified. The aim of the study is to assess the immunological profile, growth factors, early diagnosis and prognosis of current forms of occupational lung diseases. Materials and methods . To assess the cytokine profile of dust lung diseases (varying degrees of severity of chronic dust bronchitis, silicosis and pneumoconiosis from exposure to welding aerosols), 161 people were examined in the main groups: 1 group–35 people who had long-term industrial contact with industrial fibrogenic aerosols, who did not show clinical and radiological signs of lung damage (contact); 2 group–39 people with chronic dust bronchitis; Group 3–56 patients with silicosis (mainly interstitial form, x-ray characteristics of the process corresponded to categories from s1 to u2); group 4–31 patients with pneumoconiosis from exposure to highly dispersed welding aerosols (mainly nodular form, x-ray characteristics of the process corresponded to categories P1, P2, q1, q2). The 5 (control) group included 60 people-donors of the Samara Regional Clinical Blood Transfusion Station, as well as employees of industrial enterprises and institutions who did not have contact with industrial fibrogenic aerosols (healthy). Serum levels of immunoglobulins A, M, and G were determined by radial Manchini immunodiffusion. Evaluation of total immunoglobulin e (IgE), immunoglobulins A, M, G (Ig A, M, G), cytokines: interleukins 1α, 1β, 4, 8 (IL–1α, IL–1β, IL–4, IL–8), interferon γ (ifny), tumor necrosis factor α (TNFa), fibroblast growth factor (FGF2), vascular endothelial growth factor (VEGF) in blood serum it was carried out by the method of solid-phase Enzyme immunoassay. in the machine-building and mining industries. Chronic lung diseases, including occupational diseases, are one of the most urgent problems of modern respiratory medicine and cause a decrease in the quality of life, working capacity and increased mortality of the working population. The features of the course of dusty lung diseases at the early stages of the pathological process are insufficiently studied, and functional and biological markers — criteria for individual prognosis of the patient’s condition-have not been identified. The aim of the study is to assess the immunological profile, growth factors, early diagnosis and prognosis of current forms of occupational lung diseases. Materials and methods. To assess the cytokine profile of dust lung diseases (varying degrees of severity of chronic dust bronchitis, silicosis and pneumoconiosis from exposure to welding aerosols), 161 people were examined in the main groups: 1 group–35 people who had long-term industrial contact with industrial fibrogenic aerosols, who did not show clinical and radiological signs of lung damage (contact); 2 group–39 people with chronic dust bronchitis; Group 3–56 patients with silicosis (mainly interstitial form, x-ray characteristics of the process corresponded to categories from s1 to u2); group 4–31 patients with pneumoconiosis from exposure to highly dispersed welding aerosols (mainly nodular form, x-ray characteristics of the process corresponded to categories P1, P2, q1, q2). The 5 (control) group included 60 people-donors of the Samara Regional Clinical Blood Transfusion Station, as well as employees of industrial enterprises and institutions who did not have contact with industrial fibrogenic aerosols (healthy). Serum levels of immunoglobulins A, M, and G were determined by radial Manchini immunodiffusion. Evaluation of total immunoglobulin e (IgE), immunoglobulins A, M, G (Ig A, M, G), cytokines: interleukins 1α, 1β, 4, 8 (IL–1α, IL–1β, IL–4, IL–8), interferon γ (ifny), tumor necrosis factor α (TNFa), fibroblast growth factor (FGF2), vascular endothelial growth factor (VEGF) in blood serum it was carried out by the method of solid-phase Enzyme immunoassay. Results . The features of the flow of dust lung diseases: the peculiarities of the immunological profile, increasing the level of factors allows to characterize the occurrence, course and progression of dust diseases of the lungs. Conclusions . Determining the immunological profile allows not only to improve the quality of early diagnosis, but also to optimize strategies for primary and secondary prevention in this pathology, to predict the course of the disease, and to reduce the number of disabling forms.

Polyaniline/carbon (Pani/C) composites were synthesized by oxidative polymerization of aniline in the presence of carbon material at different pH values. Composites obtained possess identical composition (56 wt% of polymer as determined by CHNS elemental analysis) but differ in morphology and porous structure. Biomass-derived activated carbon having specific surface area of 1740 m2 g−1 was used as carbon component. Porous structure was characterized by low-temperature nitrogen adsorption at 77 K. The electrochemical behavior of the samples was investigated by cyclic voltammetry in a three-electrode cell in different electrolytes: aqueous 1 M H2SO4 and 1 M solution of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) in acetonitrile (ILE). Based on cyclic voltammetry data mechanism of polyaniline transformations in ILE involving BMIM+ as a proton source was proposed. Symmetric supercapacitors (SC) were assembled with Pani/C electrodes and ILE. Study of SC by the set of electrochemical techniques and investigation of the electrode structure prior and after stability tests performed by Fourier transform infrared spectroscopy allowed to reveal the main regularities of SC performance and evolution of material properties.

The prospects for the protection of high-voltage 4H-SiC-devices from edge breakdown via the formation of mesa structures with inclined walls (negative beveling) are considered. Numerical simulation of the spatial electric-field distribution in high-voltage (~1500V) reverse-biased mesa-epitaxial p+–p–n0–n+ 4H-SiC diodes is performed. It is shown that negative beveling with small angles of less than 10° from the plane of the p–n0 junction makes it possible to reduce severalfold the surface edge electric field as compared to that in the bulk. A combined protection method is suggested as the edge-termination technique for 4H-SiC diodes with a p+–n0–n+ structure, Schottky diodes with an n0 blocking base, and bipolar n+–p–n0 transistors via the implantation of boron along with negative beveling. The possibility of fabricating mesa structures with inclined walls via the photolithography and dry etching of silicon carbide is briefly discussed.

The polycondensation of the mixture of diamines 5,5-methylene bis(2-aminophenol) and 4,4-(hexafluoroisopropylidene)dianiline (molar ratio 0.8:0.2) with isophthaloyl dichloride was used to synthesize poly(amido-o-hydroxy amide) (POA-F) - new heat resistant binder of the composites for microelectronics. The copolymer was fractionated, its hydrodynamic, optical, and conformational properties were researched, and molecular masses (ММ) of the fractions were defined. The polydispersity index was estimated. Based on experimental data, calculation of the size of a segment of Kuhn characterizing degree of an intramolecular orientation order and value of coefficients of the equation of Mark-Kuhn-Hauvink for viscometric and diffusion data were performed. It was demonstrated that introducing 20 mol % of the monomer with -CF3-groups does not lead to any changes in conformational properties of the macromolecules and does not change the degree of intramolecular orientational order (the Kuhn segment length). Optical characteristics of POA-F solutions are virtually similar to the corresponding values for POA prepared with the use of single amine-containing component-5,5-methylene bis(2-aminophenol). The received MM distribution for POA-F (prepolymer) provided the solubility of its films in alkaline solutions. The heat resistance (τ5 and τ10-temperatures corresponding to 5% and of 10% PBO-F mass loss of a polymer) of the powders and the films of PBO, PBO-F were determined. The electrophysical parameters-dielectric permittivity (e) and dielectric loss tangent (tan δ) of the PBO-F films decreased down to 3.30 and 0.017, in comparison 3.40 and 0.025 for PBO respectively.

Structurally related poly(amido-o-hydroxy amides) derived from 5,5-methylenebis(2-aminophenol) with tetramethylsiloxane and heteroaromatic (benzoxazole and benzotriazole) fragments incorporated in the second amine component or formed by polyheterocyclization of the corresponding prepolymers were prepared. The effect of modifying fragments introduced into the base poly(o-hydroxy amide) on the heat resistance of powders and films and of films of photosensitive compounds based on the synthesized polymers with the naphthoquinone diazide component was analyzed. The electrophysical parameters of the polymer films and film composites with a nanodispersed ferroelectric filler, (PZT: ceramic powder with the composition Pb0.81Sr0.04Na0.075Bi0.075(Zr0.58 Ti0.42)O3, Russian brand PZT-1), prepared on the basis of modified polymer binders, were determined. Introduction of 20 mol % sulfur-containing fragments into the polymer binder ensures a 50–65˚C increase in the heat resistance for all types of films without increasing the level of the dielectric loss for the composite coatings.

The results of a study of chitosan membranes exhibiting enhanced antimicrobial properties are described in this work. It has been shown that a promising approach to imparting antibacterial and antifungal properties to filtration membranes containing chitosan in a water-insoluble base chemical form is their modification with nanocluster silver. Various nanocluster silver preparations have been compared to identify the sample exhibiting the highest antimicrobial activity. Water-resistant chitosan membranes with the addition of various amounts of nanocluster silver from the Argovit preparation have been synthesized and tested for antimicrobial activity against aerobic and anaerobic bacteria and mold and yeast-like fungi. It has been found that the membranes modified with nanocluster silver exhibit high antimicrobial activity and can be used to purify biological products synthesized by membrane methods from pathogenic bacteria and fungi.

The influence of structure of styrene-butadiene-styrene rubber on the quality characteristics of polymer-modified bitumen – produced on its basis – was identified. A program for a compromise assessment of the preference of such polymers using fuzzy sets was developed. A mathematical model was obtained that is recommended for use to optimize production and reduce costs in the industrial production of polymer-modified bitumen.