Implementation of problem-based learning while studying the discipline «technical mechanics»

The article discusses the possibility of implementing the technology of problem learning to form students ' professional and General competenciesВ статье рассматриваются возможности реализации технологии проблемного обучения для формирования у студентов профессиональных и общих компетенци

Plasmon Resonance in а-С : Н Films Modified with Platinum Nanoclusters

Optical density spectra of amorphous diamond-like films of hydrogenated carbon modified with plati-num impurity (a-C : H) have been investigated. a-C : H films were prepared by the method of ion plasma magnetron co-sputtering of graphite and platinum in argon-hydrogen atmosphere. Platinum con-tent in the films was varied from 0 to 9 at. %. In the optical spectra of a-C : H films with different Pt content the peaks of resonance absorption in the range from 496 to 501 nm were found, whilst in the spec-trum of a-C : H films the absorption peak is absent. The appearance of these absorption peaks in a-C : H films is explained by resonance plasmon vibrations of free electrons in platinum nanocl usters. The average diameter of the Pt nanoclusters was estimated using electromagnetic theory of Mie, and it is ~ 5 nm. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3638

Asymmetric Faraday Effect in a Magnetophotonic Crystal

It is widely known that the magneto-optical Faraday effect is linear in magnetization and therefore the Faraday angles for the states with opposite magnetizations are of opposite sign but equal in modulus. Here we experimentally study propagation of light through a one-dimensional all-garnet magnetophotonic crystal to demonstrate an asymmetric Faraday effect (AFE) for which Faraday angles for opposite magnetic states differ not only in sign but in the absolute value as well. AFE appears in the vicinity of the cavity resonance for an oblique incidence of light which plane of polarization is inclined to the incidence plane. Under proper incidence and polarization angles the magnitude of AFE could be very large reaching 30% of the absolute value of the Faraday effect. The effect originates from the difference in Q-factors for p- and s- polarized cavity modes that breaks the symmetry between the two opposite directions of polarization rotation. The discovered AFE is of prime importance for nanoscale magnonics and optomagnetism.Comment: Supplementary information provided after the main tex

Power spectrum features of the near-Earth atmospheric electric field in Kamchatka

Power spectrum of the diurnal variations of the quasi-electrostatic field Ez in the near-Earth atmosphere have been presented for the first time. The Ez power spectrum variations in the period of fine weather have been shown to exhibit two bands of the periods of natural atmospheric oscillations with T = 1-5 and 6-24 h. These oscillations are the modes of the internal gravity and tidal waves in the lower atmosphere. On the days under atmospheric precipitation, the spectral power of Ez increases by an order of magnitude. During the pre-earthquake period, when the diurnal Ez variation had an anomaly, the intensity of harmonics with T = 1.8, 2.2, and 3.8 h increased by an order of magnitude or more in comparison with the Ez spectra in fine weather. Two additional spectral bands with T = 0.6 and 1 h have appeared simultaneously

Comparative analysis of the ICT development level in the CIS and the european Union

В статье для стран Евросоюза и СНГ с помощью метода главных компонент факторного анализа построен интегральный показатель уровня развития информационно-коммуникационных технологий (ИКТ). Построен и проанализирован рейтинг стран, выявлены показатели, в наибольшей степени влияющие на интегральный показатель уровня развития ИКТ. Использовалась система из 11 показателей. In the article for the countries of the European Union and the CIS, using the method of the principal components of factor analysis, an integral indicator of the level of development of information and communication technologies (ICT) is constructed. The rating of countries is built and analyzed; indicators are identified that have the greatest impact on the integral indicator of the level of ICT development. A system of 11 indicators was used

Probiotic activity of <i>Bacillus subtilis</i> metabolites in experimentally induced dysbiosis in mice

Scientific relevance. A promising option for dysbiosis correction is the use of metabiotics, products based on metabolites of probiotic microorganisms. During fermentation, Bacillus subtilis bacteria (strains 3H and 1719) produce metabolites that exhibit probiotic properties in vitro. These observations in vitro motivate an in vivo investigation of B. subtilis metabolite effects on colonic mucosal microbiota in mice in experimentally induced dysbiosis and an assessment of the potential of B. subtilis metabolites as metabiotics.Aim. The authors aimed to compare the probiotic activity of B. subtilis 3H and B. subtilis 1719 metabolites and a commercial metabiotic in antibiotic-induced dysbiosis in mice.Materials and methods. The authors induced experimental dysbiosis in BALB/c mice weighing 18–20 g by intraperitoneal injection of gentamicin. For subsequent correction, the test groups received sorbent-bound B. subtilis metabolites, and the comparison group received a commercial metabiotic containing B. subtilis metabolites (VKPM B-2335(3)3) via intragastric injection for 21 days. The quantitative and qualitative analysis of colonic mucosal microbiota included microbial culturing and colony identification by MALDI-TOF mass spectrometry.Results. Antibiotic-induced colonic dysbiosis in mice manifested itself as a decrease in the dominant microbiota and an increase in opportunistic pathogens. After 7 days of metabolite administration, the Lactobacillus population returned to normal in all treatment groups. The mice that received B. subtilis 3H metabolites showed the best results: their Lactobacillus spp. composition corresponded to that of intact animals. The content of Lac+ Escherichia coli returned to 100% in all treatment groups. After 21 days of metabolite administration, the authors observed the elimination of bacteria (Rodentibacter spp., Aerococcus spp.) and fungi (Trichosporon spp., Kazachstania spp.) in the B. subtilis 3H group; Trichosporon spp. (no effect on Kazachstania spp.) in the B. subtilis 1719 group; and Enterococcus spp., Kazachstania spp., and Trichosporon spp. (no effect on Rodentibacter spp. and Aerococcus spp.) in the commercial metabiotic group.Conclusions. Metabolites of B. subtilis strains 3H and 1719 help to restore the diversity and abundance of colonic microbiota in antibiotic-induced dysbiosis. The differences observed in microbiota re-establishment in the treatment groups indicate that there is interstrain variability in the probiotic activity of B. subtilis metabolites

Effect of additions of zinc stearate on the properties of sintered Nd-Fe-B magnets

Zinc stearate additions have been used to increase the remanence of sintered Nd-Fe-B magnets produced by the powder metallurgy without powder pressing. Zinc stearate acts as an internal lubricant, i.e., it decreases the friction forces between the particles and favors an increase in the degree of texture of the powders, which is induced by the magnetic field. It is shown that the density and the magnetic hysteresis characteristics of sintered magnets produced using additions of 0.15 wt % zinc stearate exceeds the corresponding values obtained for magnets produced without this addition at a filling density of powders in containers of more than 2.9 and 3.0 g/cm3 in dry and wet states, respectively. Using additions of zinc stearate in the amount of 0.15% with respect to the weight of the powder, magnets with a density of 7.55 g/cm3, B r = 14.02 kG, H c = 7.91 kOe, and (BH)max = 46.1 MG Oe have been produced. © 2013 Pleiades Publishing, Ltd

DIFFERENTIATION OF NK CELLS. A LOOK THROUGH THE PRISM OF TRANSCRIPTION FACTORS AND INTRACELLULAR MESSENGERS

All lymphoid cells are referred to as an innate or adaptive immunity unit in terms of the mechanisms of performing immune reactions. The functional activity of natural killer (NK) cells is not associated with pre-activation processes resulting from contact with antigen, rearrangement of antigen-recognition receptor genes, and clonal proliferation. In this regard, NK cells are traditionally referred to as cells of innate immunity. Previously, it was believed that NK cells represent the only population of innate immunity lymphoid cells, but, more recently, there has been increasing evidence in the literature concerning existence of different populations of these cells, thus serving a basis for isolating a common cluster called Innate Lymphoid Cells (ILC). According to the ILC classification, NK cells are classified as the first group of innate lymphoid cells according to their overall functional characteristics, as well as contribution of the T-bet transcription factor to their differentiation. Complexity, multistage and partially nonlinear character of NK cell differentiation are associated with influence of the cellular microenvironment, consistent expression of transcription factors and activation of various intracellular signaling pathways in NK cells. The review considers positioning of NK cells in the ILC classification, the main transcription factors involved in NK cell differentiation. The authors are seeking for generalization of the major routes of intracellular signal transmission in NK cells depending on their activation by cytokines located in the cellular microenvironment and affecting NK cells. The decidual NK cells during pregnancy represent a special object of NK cell differentiation. Stromal cells, trophoblast cells and macrophages are present in the decidua, in addition to NK cells. The review concerns a special case of microenvironmental effects upon expression of transcription factors and activation of NK intracellular messengers, while considering trophoblast cells an example of such influences. The recently discovered variety of NK cells, induced by the microenvironment in the course of their differentiation, requires further study

Decidual natural killer cells and trophoblast cells: cellular, humoral and molecular mechanisms of interaction

Natural killer cells (NK cells) represent a group of lymphocytes of innate immunity. In addition to NK cells of peripheral blood, tissue-resident populations are described. NK cells of the decidual envelope (decidual NK cells) represent one of the local NK cell populations. Decidual NK cells differ in phenotype and function from peripheral blood NK cells. These cells have, mainly, regulatory functions. At the same time they retain the ability to perform cytotoxic effects. In the uterus, NK cells are located closely to the cells of fetal origin, i.e., trophoblast cells, which differentiate from the outer layer of the invading blastocyst. The purpose of the review article was to analyze the literature data on the studies of the molecular interactions between NK cells and trophoblast cells, as well as potential means of regulating these interactions. The review presents currently available data on receptor-mediated effects (due to adhesion molecules and cytotoxic receptors) and distant interactions (involving cytokines, chemokines and growth factors secreted by the both cell types) between NK population and trophoblast cells. The receptors regulating contacts of NK cells and trophoblast cells with extracellular matrix are also considered. The review provides information on activation of signaling pathways in NK cells and trophoblast cells resulting from their interaction with each other and components of the extracellular matrix. Currently, the molecular mechanisms regulating the NK cell functions and their interaction with trophoblast cells have not been studied sufficiently. The authors attempted to consider molecular regulation of the functional activity of NK cells mediated by the molecular complex of RNA polymerase II. We also describe participation of cyclin-dependent CDK8/19 kinases which comprise a part of the mediator complex which provides functioning of immune cells. The data on the participation of CDK8/19 in regulation of intracellular signaling pathways, as well as influence of CDK8/19 on the NK cell functions, are considered. Summarizing the data presented in the literature, one may emphasize that there is an extensive mutual influence of NK cells and trophoblast cells in decidual lining of uterus during pregnancy, thus leading to a changes in phenotype and functions of these cells. Experimental studies are required on the contribution of molecular mechanisms involved in transcription and translation processes to the biology of NK cells, and their role in maintaining interactions between NK cells and trophoblast cells, including the pathways involving CDK8/19

SPECT/CT WITH 99MTC-MIBL IN MONITORING OF ESTHESIONEUROBLASTOMA

This article describes a new approach to the diagnosis of esthesioneuroblastoma. The classical algorithm examination included the whole body 99mTc-MIBI scans and SPECT/CT of the head. There is no data on this method of diagnosis of esthesioneuroblastoma in the scientific literature. A qualitative visualization of the primary tumor and its recurrence after multimodality treatment was reached. SPECT/CT with 99mTc-MIBI is a promising method for detecting esthesioneuroblastoma, however further studies are required