1,036 research outputs found

    Технологическое и аппаратурное оформление ферментационного узла процесса получения биопротеина из природного газа

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    Objectives. To conduct a comparative analysis of the features of a fermentation unit design for obtaining bioprotein from natural gas and determine the main technical and structural solutions used in the development of fermentation apparatus, which vary according to the method of organizing hydraulic and mass transfer processes.Results. An analysis of publications devoted to the problem of developing technological equipment for conducting the process of obtaining a bioprotein from natural gas is presented. Using the comparative analysis, the key features of bioreactors and their internal elements are indicated according to the method of organizing the hydrodynamic regime. The main approaches to the technological development of fermentation units for obtaining bioprotein from natural gas are described and technical solutions used in the implementation of these structures are identified.Conclusions. Fermenter designs for the cultivation of methane-oxidizing microorganisms vary according to the main approaches for implementing the hydraulic regime inside the apparatus. While one class of fermentation systems is based on the principle of volumetric mixing in the working space of the apparatus, with the possibility of including external circulation circuits, additional tanks, and auxiliary bioreactors in the system, the other main class relies on the principle of flow (displacement) in the tube space with subsequent release of the gas phase from the circulating culture liquid.Цели. Провести сравнительный анализ особенностей аппаратурного оформления ферментационного узла процесса получения биопротеина из природного газа. Определить основные технические и конструкционные решения, применяемые при разработке ферментационных аппаратов, различающиеся по способу организации гидравлических и массообменных процессов.Результаты. Проведен анализ литературы, посвященной проблеме разработки технологической аппаратуры для получения биопротеина из природного газа. С использованием метода сравнительного анализа были выявлены ключевые особенности конструкций биореакторов и их внутренних элементов, отличающихся способом организации гидродинамического режима в аппаратах. Описаны различные подходы к разработке оборудования для ферментационного узла процесса получения биопротеина, а также определены основные технические решения, используемые при создании данных конструкций.Выводы. Установлено, что большинство конструкций ферментационных аппаратов, предназначенных для культивирования метанокисляющих микроорганизмов, базируется на реализации гидравлического режима внутри аппарата. Часть ферментационных систем построена на принципе объемного перемешивания в рабочем пространстве аппарата с возможным включением в систему внешних циркуляционных контуров, дополнительных емкостей и вспомогательных биореакторов, другая часть использует принцип движения потока (вытеснения) в трубном пространстве, с последующим выделением газовой фазы из рециркулирующей культуральной жидкости

    Statistical model and method for analyzing AI conference rankings: China vs USA

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    Artificial Intelligence (AI) is a rapidly developing field of research that attracts significant funding from both the state and industry players. Such interest is driven by a wide range of AI technology applications in many fields. Since many AI research topics relate to computer science, where a significant share of research results are published in conference proceedings, the same applies to AI. The world leaders in artificial intelligence research are China and the United States. The authors conducted a comparative analysis of the bibliometric indicators of AI conference papers from these two countries based on Scopus data. The analysis aimed to identify conferences that receive above-average citation rates and suggest publication strategies for authors from these countries to participate in conferences that are likely to provide better dissemination of their research results. The results showed that, although Chinese researchers publish more AI papers than those from the United States, US conference papers are cited more frequently. The authors also conducted a correlation analysis of the MNCS index, which revealed no high correlation between MNCS USA vs. MNCS China, MNCS China/MNCS USA vs. MSAR, and MNCS China/MNCS USA vs. CORE ranking indicators.Merit, Expertise and Measuremen

    Evaluation of the antiprotozoan properties of 5'-norcarbocyclic pyrimidine nucleosides

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    Carbocyclic nucleoside analogues have a distinguished history as anti-infectious agents, including key antiviral agents. Toxicity was initially a concern but this was reduced by the introduction of 5'-nor variants. Here, we report the result of our preliminary screening of a series of 5'-norcarbocyclic uridine analogues against protozoan parasites, specifically the major pathogens Leishmania mexicana and Trypanosoma brucei. The series displayed antiparasite activity in the low to mid-micromolar range and establishes a preliminary structure-activity relationship, with the 4',N(3)-di-(3,5-dimethylbenzoyl)-substituted analogues showing the most prominent activity. Utilizing an array of specially adapted cell lines, it was established that this series of analogues likely act through a common target. Moreover, the strong correlation between the trypanocidal and anti-leishmanial activities indicates that this mechanism is likely shared between the two species. EC50 values were unaffected by the disabling of pyrimidine biosynthesis in T. brucei, showing that these uridine analogues do not act directly on the enzymes of pyrimidine nucleotide metabolism. The lack of cross-resistance with 5-fluorouracil, also establishes that the carbocyclic analogues are not imported through the known uracil transporters, thus offering forth new insights for this class of nucleosides. The lack of cross-resistance with current trypanocides makes this compound class interesting for further exploration

    Biotransformation of fenbendazole in sheep after administration of fenbendazole solid dispersion prepared by mechanochemical technique with arabinogalactane

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    The purpose of the research is to study the biotransformation of fenbendazole in the body of sheep after administration of fenbendazole solid dispersion (FSD) prepared by mechanochemical technique with arabinogalactan. Materials and methods. The FSD at a dose of 2.0 mg/kg for the active substance was administered orally to sheep. Animal blood serum samples were studied by high performance liquid chromatography / tandem mass spectrometry (HPLC-TMS) to determine the concentration of fenbendazole (FBZ) and its sulfoxide and sulfone metabolites at 0, 1, 2, 4, 6, 8, 12, 24, 33, 48 and 72 hours after administered FSD and initial FBZ (substance). FBZ and its metabolite residual quantity in the organs and tissues of the sheep was determined at 1, 3, 6, 11, and 21 days after the drug administration. The prepared sample and validated method were described. Results and discussion. A significant difference was found in the metabolism, pharmacokinetics, and timing of the FBZ and its metabolite elimination after the base drug (FBZ substance) and FSD were administered to sheep in an equal dose of 2.0 mg/kg for the active substance. FBZ and its metabolites began to be detected in blood serum 2 hours after the FSD and 4 hours after the base FBZ. Pharmacokinetic parameters of FBZ and its metabolites characterize a higher drug concentration in the blood and a longer retention time in the circulation after the FSD as compared with the base drug parameters. The FBZ and its metabolite maximum concentration was found in the organs and tissues of the sheep that received the FSD on day 3 in the liver amount of 4862.3±296.2 ng/g of FBZ; 18243.5±486.1 ng/g of sulfoxide; and 2482.3±132.4 ng/g of sulfone; and tens of times lower concentration after the base FBZ on day 6. FBZ and its metabolites were not detected in the organs and tissues of the sheep on day 16 after the base FBZ, and on day 21 after the FSD

    Oxidative Stress during HIV Infection : Mechanisms and Consequences

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    Publisher Copyright: © 2016 Alexander V. Ivanov et al.It is generally acknowledged that reactive oxygen species (ROS) play crucial roles in a variety of natural processes in cells. If increased to levels which cannot be neutralized by the defense mechanisms, they damage biological molecules, alter their functions, and also act as signaling molecules thus generating a spectrum of pathologies. In this review, we summarize current data on oxidative stress markers associated with human immunodeficiency virus type-1 (HIV-1) infection, analyze mechanisms by which this virus triggers massive ROS production, and describe the status of various defense mechanisms of the infected host cell. In addition, we have scrutinized scarce data on the effect of ROS on HIV-1 replication. Finally, we present current state of knowledge on the redox alterations as crucial factors of HIV-1 pathogenicity, such as neurotoxicity and dementia, exhaustion of CD4+/CD8+ T-cells, predisposition to lung infections, and certain side effects of the antiretroviral therapy, and compare them to the pathologies associated with the nitrosative stress.publishersversionPeer reviewe
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