96 research outputs found

    Changes in the agrochemical parameters of sod-podzolic soils under the influence of chromium pollution and recultivation measures

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    In the conditions of the Udmurt Republic, field experiments (2017-2021) were carried out on the remediation of  agro-podzolic loamy soil (albeluvisoils) with a high level of chromium contamination (application of 500 mg a.i./kg of soil). Both chemical and physicochemical mechanisms have been used to reduce the degree of mobility of this heavy metal in soil. Ameliorants and fertilizers (limestone and phosphate rock, superphosphate, potassium humate, peat, zeolite) in various doses were studied as ameliorative additives. Various doses of ameliorants and fertilizers were studied as ameliorative additives: limestone and phospharite meal, superphosphate, potassium humate, peat and zeolite. As a result of the research, it was found that all ameliorative additives not only caused a sharp decrease in the mobility of chromium by 40-65 %, but also had a positive effect on the agrochemical parameters of the contaminated soil. The nature and parameters of this influence were determined by their chemical composition, the rate of application, and the period that passed after the application. Limestone flour statistically significantly reduced soil acidity in contaminated soil (by 1.21-3.03 pHKCl units) and increased the total of absorbed bases by 1.7-6.5 times. Phospharite meal (by 2.1-9.1 times) and superphosphate (by 13-43 %) increased the mobile phosphorus content in the soil; peat increased the organic matter content (by 0.28-1.47 abs.%); zeolite increased the total exchangeable bases by 1.4-9.8 mmol/100g or by 12-239 %. The positive effect of these ameliorative additives, especially their increased doses, was traced during all five years of observation, what allows them to be recommended as promising ameliorants for restoring the fertility of soddy-podzolic soils contaminated with chromium

    Experimental comparison of induction and synchronous reluctance electric drive performance

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    Работа имеет целью экспериментальное сравнение конструктивных и энергетических характеристик современных асинхронных двигателей (АД) отечественного и зарубежного производства (ABB) и разработанного авторами синхронного реактивного двигателя (СРД) в составе частотно-регулируемого электропривода. Рассматриваемый в работе опытный образец двигателя спроектирован на основе статора АД. Результаты работы показывают, что применение СРД позволяет значительно повысить КПД частотно-регулируемого привода. При этом СРД может соответствовать самому высокому классу энергоэффективности IE4. В то же время конструкция двигателя остается простой и дешевой.The work is aimed at experimental comparison of constructive and energy characteristics of modern asynchronous electric motors of Russian and European manufacturers (ABB Ltd.) and the synchronous reluctance motor developed by the authors as a part of variable frequency drive. The prototype motor was designed based on the stator of an induction motor. The issues show that it is possible to significantly improve the efficiency of the variable frequency drive by use of a synchronous reluctance motor. The motor can correspond to the highest energy efficiency class IE4. At the same time the motor design is simple and cheap

    Mechanisms of interacting <i>Helicobacter pylori</i> with gastric mucosal epithelium. II. A reaction of gastric epithelium on <i>Helicobacter pylori</i> colonization and persistence

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    Gastric and duodenal recurrent inflammatory diseases have a high prevalence, but the role played by microbes in its development remained unclear. However, the data published in 1983 by Marshall and Warren about isolating Helicobacter pylori from the stomach mucosa of the patient with gastritis and proposing relevant cultivation methods was the turning point in investigating etiology of the upper digestive tract inflammatory disorders. Moreover, it was shown that the majority of H. pylori spp. are found within the gastric lumen upon colonization, whereas around 20% of them are attached to the epithelial cells in the stomach. In addition, effects of interacting H. pylori with gastric epithelium and activation of some defense mechanisms due to bacterial colonization and spreading were analyzed. It was found that along with triggering pro-inflammatory response induced by proteins VacA as well as phosphorylated/unphosphorylated CagA, wherein the latter is able to induce a set of protective reactions H. pylori disrupts intercellular contacts, affects epithelial cell polarity and proliferation, and activates SHP-2 phosphatase resulting in emerging diverse types of cellular responses. The activation mechanisms for the mitogen-activated protein kinase (MAPK) pathway were discussed. The ability of H. pylori to regulate apoptosis, particularly via its suppression, by expressing ERK kinase and protein MCL1 facilitating bacterial survival in the gastric mucosa as well as beneficial effects related to bacterial circulation on gastric epithelial cell survival elicited by anti-apoptotic factors were also examined. Of note, persistence of H. pylori are mainly determined by activating transcriptional factors including NF-κB, NFAT, SRF, T-cell lymphoid enhancing factor (TCF/LEF), regulating activity of MCL1 protein, in turn, being one of the main anti-apoptotic factors, as well as induced production of the migration inhibitory factor (MIF). The role of VacA cytotoxin in triggering epithelial cell apoptosis via caspase-mediated pathways was also considered. Infection with H. pylori is accompanied by release of proinflammatory cytokine cocktail detected both in vitro and in vivo. In particular, bacterial urease activating transcriptional factor NF-κB was shown to play a crucial role in inducing cytokine production. Moreover, such signaling pathways may be activated after H. pylori is attached to the cognate receptor in the gastric epithelial surface by interacting with CD74 and MHC class II molecules. Finally, a role for various CD4+ T cell subsets, particularly type 17 T helper cells (Th17) in inducing immune response against H. pylori antigens in gastric mucosa was revealed were also discussed

    Synthesis and biological evaluation of novel carboxylate phosphabetaines derivatives with long alkyl chains

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    © 2016 Taylor & Francis Group, LLC.The purpose of the present study was to investigate the antibacterial activity of novel alkyl esters of carboxylate phosphabetaine: β-(carboxyalkyl)ethyltributylphosphonium bromides 4–8. The in vitro microbiological activity of the synthesized phosphonium bromides against gram-positive, gram-negative bacteria and the yeast Candida albicans was determined in comparison to standard agents. Microbiological results indicate the synthesized phosphonium salts possess a broad spectrum of activity against the testedmicroorganisms. Every newly synthesized compound was characterized by elemental analyses, IR, 1H NMR, 31P NMR spectral studies

    Synthesis and structure of novel phosphorylated azomethines

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    © 2016 Taylor & Francis Group, LLC.The condensation of do-, hexa-, octadecan-1-amines with bromo- and nitrobenzaldehydes yielded a series of Schiff bases in good yields. Subsequent reaction of these compounds with dioctylphosphine oxide yielded phosphorylated azomethines and some were characterized using X-ray crystallography. The structure of the isolated compounds was determined by IR and NMR spectroscopy, elemental analysis, and their thermal stability was studied by simultaneous thermogravimetry and differential scanning calorimetry. All of the synthesized compounds were tested for their antibacterial and anti-Candida activity. A number of the compounds exhibited antimicrobial activity comparable to that of the commercially available drugs, ciprofloxacin and clotrimazole

    Tumor Necrosis Factor-mediated survival of CD169<sup>+</sup> cells promotes immune activation during vesicular stomatitis virus infection

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    Innate immune activation is essential to mount an effective antiviral response and to prime adaptive immunity. Although a crucial role of CD169+ cells during vesicular stomatitis virus (VSV) infections is increasingly recognized, factors regulating CD169+ cells during viral infections remain unclear. Here, we show that tumor necrosis factor is produced by CD11b+ Ly6C+ Ly6G+ cells following infection with VSV. The absence of TNF or TNF receptor 1 (TNFR1) resulted in reduced numbers of CD169+ cells and in reduced type I interferon (IFN-I) production during VSV infection, with a severe disease outcome. Specifically, TNF triggered RelA translocation into the nuclei of CD169+ cells; this translocation was inhibited when the paracaspase MALT-1 was absent. Consequently, MALT1 deficiency resulted in reduced VSV replication, defective innate immune activation, and development of severe disease. These findings indicate that TNF mediates the maintenance of CD169+ cells and innate and adaptive immune activation during VSV infection
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