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

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

Thermodynamic Properties of N-Methyl-Substituted Ethane-1,2-diamines: Experimental and Computational Study

© 2016 American Chemical Society.Vapor pressures for four N-methyl-substituted ethane-1,2-diamines were measured using the transpiration method. Enthalpies of vaporization were derived from the temperature dependence of the vapor pressures. Consistency of the experimental data was assessed and confirmed with group-additivity (GA) and quantum-chemical (QC) methods. Further confirmation of the results is provided through combined assessment with properties reported in the literature for the parent compound ethane-1,2-diamine and a group of alkyl-substituted alkane-1,2-diamines. The effective application of modern QC methods in critical evaluation of enthalpies of vaporization and enthalpies of formation is demonstrated

Balancing sales and safety: A methodological approach to economic security analysis of enterprises

© Medwell Journals, 2017. Economic security analysis requires an evaluation of potential threats to the economic activity of an enterprise. These threats may be both internal and external. They are determined by various developmental factors such as notably, political conditions, changes in product supply and demand, the state of the capital market and the labor market as well as many others. Under the influence of these factors, the activity of any enterprise undergoes fluctuations, forming a trajectory of development. Such a trajectory provides a highly useful tool for analyzing an enterprise's activity from the perspective of its economic security. The study aims to introduce a methodological approach to economic security analysis of enterprises. The need for such methodological tools has only recently become the subject of academic discussion. The approach proposed in the study is twofold. First, it involves measuring the amplitude of the trajectory of the enterprise's development with respect to a safety corridor determined by acceptable rates of sales growth. Second, it requires analyzing indicators that characterize the environment and the enterprise's activity in order to determine those that go beyond the safety corridor. The study describes two different analytic methods to address the difference in stages of growth and decline in an enterprise's business activity. This dual approach results in data that identifies upper and lower limits of the safety corridor. This information will allow the company's management to focus its attention on eliminating factors that cause indicators to go beyond the limits of the safety corridor, an approach that will result in safer and more stable development

Experimental comparison of induction and synchronous reluctance electric drive performance

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

Synthesis and antimicrobial activity of carboxylate phosphabetaines derivatives with alkyl chains of various lengths

The purpose of the present study was to investigate the antibacterial activity of fifteen novel nanosized alkyl esters of carboxylate phosphabetaine: β-(carboxyalkyl)ethyltriphenylphosphonium bromides 4-8, β-(carboxyalkyl)-β-methylethyltriphenylphosphonium bromides 9-13, and β-(carboxyalkyl)-α-methylethyltriphenylphosphonium bromides 14-18. The in vitro microbiological activity of the synthesized phosphonium bromides against gram-positive and gram-negative bacteria and the yeast Candida albicans was determined in comparison to standard agents. Microbiological results indicate that the synthesized phosphonium salts 4-18 possess a broad spectrum of activity against the tested microorganisms. Every newly synthesized compound was characterized by elemental analyses, IR, 1H NMR, and 31P NMR spectral studies. © 2013 Irina V. Galkina et al

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

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 antimicrobial activity of bis-4,6-sulfonamidated 5,7-dinitrobenzofuroxans

A new series of bis-4,6-sulfonamidated 5,7-dinitrbenzofuroxans 7-11 had been synthesized and tested for antimicrobial activity. The structures of new sulfanilamide derivatives were characterized by elemental analysis, IR spectroscopy, and mass spectrometry (MALDITOF). The synthesized compounds were tested for their in vitro antimicrobial activity using the disk diffusion method against Gram-positive bacteria Staphylococcus aureus; the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis; the fungal strain Aspergillus niger; and the yeast-like pathogenic fungus Candida albicans. Our results indicate that the compounds 7-11 exhibit potent antimicrobial activity. The stability of the compounds was evaluated by TG and DSC methods. © 2014 Irina V. Galkina et al

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

© 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