183 research outputs found

    Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets

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    The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment

    Expermental research of the effects of benofilin on the functional renal function in the evalution of ethylene glycol toxic loss

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    Effect of benofilin – a new compound among a new derivative of theophylline and hofitol (70 mg/kg) on functional renal function was studied based on the rat experimental model of acute kidney damage by ethylene glycol. The toxic products of the metabolism of ethylene glycol cause renal tubular damage resulting in acute renal failure (ARF). As a result of the application of benofilin its ability is established to prevent the death of animals in the first day of the experiment. By the ability to prevent impaired kidney function in rats benofilin exceeds the effect of the hofitol

    Reactor with Swirled Fluidized Bed Electrode for in Situ H2O2 Production and Utilization for Oxidative Treatment of Organic Pollutants

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    Несмотря на значительный прогресс в разработке каталитических систем окисления органических соединений в мягких условиях, их практическое использование затрудняется отсутствием дешёвых источников восстановленных форм кислорода, таких как H2O2, NaOCl и т.д. Непосредственное получение таких соединений в химическом реакторе, например, электрохимическим путём, представляется многообещающим подходом к решению этой проблемы. В данной работе предложен новый реактор для проведения окислительной обработки водных растворов, основанный на использовании закрученного псевдоожиженного электрода для электрохимического восстановления кислорода воздуха и in situ получения разбавленных растворов пероксида водорода. Реактор позволяет одновременно получать активный окислитель и использовать его для проведения окислительных реакций сразу во всём доступном реакционном объёме, что выгодно отличает его от электрохимических реакторов с плоскими электродами. В реакторе данного типа возможно применение самых разнообразных гомогенных и гетерогенных каталитических систем, использующих пероксид водородаIn spite of remarkable progress in the development of catalytic systems for oxidation at mild conditions, their application and further development are limited by the absence of cheap sources of reduced oxygen forms (H2O2, NaOCl, etc). The in situ generation of hydrogen peroxide is very promising to resolving this problem. It is suggested an approach based on in situ production of diluted hydrogen peroxide solutions from air oxygen in a new type electrochemical reactor with a swirled fluidized bed electrode for carrying out oxidative reactions with organic compounds. The reactor allows to process simultaneously the oxidant production and the oxidative reactions and to utilize entire reaction volume in contrast to electrochemical reactors with flat electrodes geometry. Reactor permits to use a variety of homogeneous and heterogeneous catalytic systems which require hydrogen peroxid

    The Mechanical Activation of Crystal and Wooden Sawdust Cellulose in Various Fine-Grinding Mills

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    Для выбора наиболее эффективного способа механической активации биомассы проведено предварительное исследование процесса измельчения и механической активации образцов кристаллической целлюлозы и лигноцеллюлозной биомассы (высушенные березовые опилки) в мельницах различных конструкций (вальцовая, планетарная, роторная, вихревая газодинамическая и вихревая с механическим разгоном материала) с изучением физико- химических характеристик продуктов помола. Методом рентгенофазового анализа (РФА) проведена идентификация фаз, определены индекс кристалличности (ИК) и средний размер областей когерентного рассеяния, определяющих эффективность активации биомассы. Методом оптической микроскопии исследована морфология и средний размер частиц (l). В качестве наиболее перспективного для последующего более детального изучения выбран метод активации лигноцеллюлозной биомассы в ударной вихревой мельнице с механическим разгоном материала, как обеспечивающий минимальные затраты энергии и времени при удовлетворительной степени измельчения и активации, продемонстрированных для высушенных берёзовых опилок (l ~ 22 мкм и ИК = 56 % при l ~ 3700 мкм и ИК =74 % для исходного сырья)The study is aimed to determine the most perspective and effective fine-grinding mills for lignocellulosic biomass mechanical activation. Physicochemical characteristics were studied for milled crystalline cellulose and milled dry birch sawdust after their treatment in various devices – ball, planetary, ring, vortex gas driven and vortex mechanically driven mills. XRD analysis method was used for phases identification, crystallinity index (CI) and mean size of coherent-scattering region (CSR) measuring. These values are suggested to be used for an assessment of the efficiency of mechanical activation process. Mean particle size (l) of milled materials was measured with help of optic microscopy as well. As the most perspective device for future detailed investigation to be done the vortex mechanically driven mill is selected. This type of mill provides both the least electrical power consumption and activation time at adequate particles destruction level and marked mechanical activation demonstrated for dry birch saw dust (it was detected the reduction of l and CI from l ~ 3700 μm/CI =74 % to l ~ 22 μm/CI = 56 %

    Green synthesis of silver nanoparticles using aqueous extract of hot chili pepper fruits and its antimicrobial activity against Pseudomonas aeruginosa

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    Green synthesis of different nanoparticles using the plants aqueous extracts has several advantages over other methods due to the environmentally favorable nature of plants. Moreover, such approach is also cost effective. This work describes the biosynthesis of silver nanoparticles (Ag-NPs) with the use of the aqueous extract of dry pericarps of hot chili peppers (Capsicum sp. cv. Teja (S-17) and cv. Carolina Reaper) with different levels of pungency and their antibacterial effect on the antibiotic resistant Pseudomonas aeruginosa. Phytochemical screening of pericarp tissues showed great distinction in contents of phenolic compounds and capsaicinoids as potential reducing agents wich correlated with total antiradical activity as analyzed by reduction of DPPH radicals. The biosynthesized Ag-NPs were characterized by UV-vis spectrophotometry and scanning electron microscopy (SEM). The average size of the nanoparticles in both samples was less than 25 nm. Іnitial concentration of both samples of Ag-NPs inhibited P. aeruginosa growth with equal efficiency

    Characteristics of the state of bone tissue in genetically modified mice with impaired enzymatic regulation of steroid hormone metabolism

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    The aim was to evaluate the structural and functional changes of bone tissue in mice with null expression of 11β-HSD2 or both 11β-HSD2 and Apolipoprotein

    Collection of microorganisms of ICG SB RAS as a genetic resource for biotechnology

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    Genetic knowledge of microorganisms plays a critical role in the creation of new biotechnologies, since the effectiveness of any biotechnology is determined by the particular qualities of the structurally functional organization of molecular-genetic systems and their components used for the production of targeted products. Collections of microbial cultures play a decisive role in mobilizing biological resources and make it possible to form a solid base for genetic, molecular biological and biotechnological research. The aim of this work was to assess the key molecular-genetic and phenotypic characteristics of strains of the collection of microorganisms created in the “FRC Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences” as a genetic resource for biotechnology. Thirty strains of microorganisms of the collection were isolated by employees of the FRC ICG SB RAS from extreme natural ecosystems, the key molecular-genetic and phenotypic characteristics were described using modern methods of molecular biology and mass-spectrometry. DNA isolation and the sequencing of 16S rRNA gene sequences were performed. The strains of the collection were characterized by morphological, physiological, moleculargenetic and mass-spectrometric characteristics. The particular qualities of growing of strains on different substrates have been established, the study of cell morphology has been carried out. The physiological characteristics of the strains of the collection have been established: the attitude to oxygen, the type of nutrition, the range of temperature and pH, the attitude to NaCl and others. Different resistance of strains to antibiotics has been established. The creation of personal mass spectra of protein profiles of the studied strains of the collection was carried out. The resulting DNA sequences of the strains are deposited in the GenBank. The chemotaxonomic characteristics of strains have been determined. The biotechnological properties of the strains were assessed, the amount of metabolites (ethanol, lactic and acetic acids) in the culture liquid was determined. The value of the collection of microorganisms of the FRC ICG SB RAS as a genetic resource for biotechnology and bioengineering is determined not only by the species diversity of its strains, but also by a wide range of their area isolation and by the depth of their characterization using the widest arsenal of both classical and modern methods (including methods of genomics, proteomics, transcriptomics and bioinformatics)

    Relevant Issues of Epidemiological Safety Provision as Regards Natural-Focal Infections during the XXII Olympic and XI Paralympic Winter Games in Sochi

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    The paper contains the data on the morbidity rates as regards natural-focal infectious diseases and results of epizootiological monitoring in the locality of the XXII Olympic and XI Paralympic Winter Games-2014 in Sochi. It is demonstrated that the significant ones in the infectious disease incidence chart are hemorrhagic fever with renal syndrome, Ixodidae tick-borne borrelioses, pseudotuberculosis, intestinal yersiniosis, leptospiroses, rabies, rickettsiosis, and tularemia. Represented are the data on the peculiarities of a number of regional pathogenic strains. Noted is fact that complex activities, which were carried out by the agencies and institutions of the Rospotrebnadzor, Krasnodar Territory and Sochi resort-town Administration, allowed for the stabilization of the situation on natural-focal infections

    Utilization of mechanical power and associations with clinical outcomes in brain injured patients. a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

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    BackgroundThere is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes.MethodsIn this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale <= 12 before intubation) who required mechanical ventilation (MV) >= 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS).ResultsWe included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22).ConclusionsExposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation

    Evolution in the Genus Rhinella: A Total Evidence Phylogenetic Analysis of Neotropical True Toads (Anura: Bufonidae)

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    True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridiza-tion and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R . horribilis (“ghost introgression”) and of R . dorbignyi into R . bernardoi; therefore, the mitochondrial and nuclear data-sets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmono-phyletic due to the position of R . ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R . ceratophrys is excluded, the genus Rhinellais monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R . spinulosa Group (including R . gallardoi); the mono-phyletic R . granulosa, R . crucifer, and R . marina Groups; and a clade composed of the mitochondrial sequences of R . horribilis. The other major clade is strongly supported and composed of all the spe-cies from the non-monophyletic R . veraguensis and R . margaritifera Groups, the former R . acrolophaGroup, and R . sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morpho-logical character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and “ghost introgression”; the incomplete phenotypic evidence (including putative character systems that could be used for future phy-logenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses.Peer reviewe
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