92 research outputs found
Self-organization and competitiveness of University students in the aspect of student self-government
The article discusses the features of self-organization and competitiveness of students taking and not taking part in student self-governmentВ статье рассматриваются особенности самоорганизации и конкурентоспособности студентов, принимающих и не принимающих участие в студенческом самоуправлени
PERMITTIVITY DISPERSION FEATURES OF A NEMATIC LIQUID CRYSTAL WITH QUANTUM DOTS
Subject of Research. The paper deals with research of dielectric properties of suspensions for a nematic liquid crystal (LC) with positive dielectric anisotropy Δε = 10.5, doped with semiconductor quantum dots (QDs) CdSe / ZnS, and dependence on their concentration in the range of 0.05-0.3 wt. %. Methods. The studies were carried out by the method of dielectric spectroscopy. A special flat titanium cell with the distance between the electrodes equal to 250 μm was used for the measurement. The voltage was applied to the electrodes. The dispersion of parallel and normal parts of the real and imaginary components of the dielectric permittivity was measured in the range from 50 Hz to 6.5 MHz at the orienting magnetic field equal to 4 • 105 A / m applied to a cell. Main Results. Deviation of the permittivity spectra of suspensions with QDs concentration growth was observed from a spectrum of the pure LC. It was caused by losses of free ions on the conductivity at frequencies below 103 Hz. The shift of a peak in the suspension spectrum at frequencies above 106 Hz is associated with relaxation of the LC molecules orientation. It has been shown that lowering in the range of 103 -104 Hz with concentration increasing up to 0.3 wt. % did not exceed 4%. Practical Relevance Obtained results give the possibility to explain the change in macroscopic properties of the liquid crystal as a result of doping
Bis{4′-[(2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecin-15-yl)methoxy]-2,2′:6′,2′′-terpyridine}cadmium(II) bis(hexafluoridophosphate) trihydrate: a powder study
The asymmetric unit of the title compound, [Cd(C30H31N3O6)2](PF6)2·3H2O, contains one half-cation with the CdII center situated on a twofold rotational axis, one hexafluoridophosphate anion and two uncoordinated water molecules, one of which is also situated on a twofold rotational axis. The cations are associated into columns along the a axis through π–π interactions between the pyridine and benzene rings, with a centroid–centroid distance of 3.72 (5) Å. Intermolecular O—H⋯O, C—H⋯O and C—H⋯F hydrogen bonds consolidate the crystal packing
Liquid silyl derivative of beta-cyclodextrin
© ISUCT Publishing. Per-6-O-(tert-butyl)(diphenyl)silyl-β-cyclodextrin was found to form metastable liquid phase, which is unusual for cyclodextrin mono-derivatives under ambient conditions. Also, it can exist in a solid amorphous state as a stable molecular glass. Conditions and parameters of phase transitions between crystal, glassy and liquid forms were determined. The studied compound is soluble in various solvents. Crystallization from its solutions and overcooled melt results in formation of two different polymorphs. The liquid mono-derivative of beta-cyclodextrin is amphiphilic and preferable for application in solutions, in pure form or even as a solvent for substrates with various structures
Polarization Separation of Light Beams at the Interface of Two Mesophases
The features of reflection of the linearly polarized light beams at the interface between two regions
of a nematic liquid crystal (LC) with the orthogonal director orientation have been analyzed. The relationship
between light beam propagation in a LC material and polarization of laser radiation has been established.
Rotation of the polarization plane of a light beam has been found for the radiation introduced through the
free surface “LC—air” deformed due to the capillarity effect. The total internal reflection effect has been
demonstrated experimentally together with the possibility for special separation of the orthogonally polarized
light beams at the interface of two mesophases.This work was supported by the Belarusian Foundation for Fundamental Research, Project F10MC-02
The Problem of Helping Behavior in the Context of Professional Training of College Students
На современном этапе развития нашего общества все актуальнее становится помогающая деятельность, которая является основной и важной частью социального развития в таких сферах, как здравоохранение, охрана окружающей среды, общественная безопасность и многое другое. В статье рассматриваются психологические особенности студентов медицинского колледжа, занимающихся и не занимающихся волонтерской деятельностью.At the present stage of development of our society, helping behavior becomes relevant. This is especially true in such areas as healthcare, environmental protection, and public safety. The article discusses the psychological characteristics of medical college students engaged and not engaged in volunteer activities
Clinical diagnostic criteria of the syndrome of vegetative dysfunction in children and adolescents
The article deals with the clinic and diagnosis of autonomic dysfunction syndrome in children and adolescents. Data on sexual and age structure, leading clinical symptoms and methods of diagnosis of autonomic dysfunction syndrome were obtained. The absence of dependence of symptoms from the cardiovascular system on the burdened family history on diseases of the cardiovascular system was revealedВ статье рассмотрены вопросы клиники и диагностики синдрома вегетативной дисфункции у детей и подростков. Получены данные о половой и возрастной структуре, ведущих клинических симптомах и методов диагностики синдрома вегетативной дисфункции. Выявлено отсутствие зависимости симптомов со стороны сердечно-сосудистой системы от отягощенного семейного анамнеза по заболеваниям сердечно-сосудистой системы
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Gender differences in the pharmacological actions of pegylated glucagon-Like peptide-1 on endothelial progenitor cells and angiogenic precursor cells in a combination of metabolic disorders and lung emphysema
In clinical practice, the metabolic syndrome (MetS) is often associated with chronic obstructive pulmonary disease (COPD). Although gender differences in MetS are well documented, little is known about sex-specific differences in the pathogenesis of COPD, especially when combined with MetS. Consequently, it is not clear whether the same treatment regime has comparable efficacy in men and women diagnosed with MetS and COPD. In the present study, using sodium glutamate, lipopolysaccharide, and cigarette smoke extract, we simulated lipid metabolism disorders, obesity, hyperglycemia, and pulmonary emphysema (comorbidity) in male and female C57BL/6 mice. We assessed the gender-specific impact of lipid metabolism disorders and pulmonary emphysema on angiogenic precursor cells (endothelial progenitor cells (EPC), pericytes, vascular smooth muscle cells, cells of the lumen of the nascent vessel), as well as the biological effects of pegylated glucagon-like peptide 1 (pegGLP-1) in this experimental paradigm. Simulation of MetS/COPD comorbidity caused an accumulation of EPC (CD45−CD31+CD34+), pericytes, and vascular smooth muscle cells in the lungs of female mice. In contrast, the number of cells involved in the angiogenesis decreased in the lungs of male animals. PegGLP-1 had a positive effect on lipids and area under the curve (AUC), obesity, and prevented the development of pulmonary emphysema. The severity of these effects was stronger in males than in females. Furthermore, PegGLP-1 stimulated regeneration of pulmonary endothelium. At the same time, PegGLP-1 administration caused a mobilization of EPC (CD45−CD31+CD34+) into the bloodstream in females and migration of precursors of angiogenesis and vascular smooth muscle cells to the lungs in male animals. Gender differences in stimulatory action of pegGLP-1 on CD31+ endothelial lung cells in vitro were not observed. Based on these findings, we postulated that the cellular mechanism of in vivo regeneration of lung epithelium was at least partly gender-specific. Thus, we concluded that a pegGLP-1-based treatment regime for metabolic disorder and COPD should be further developed primarily for male patients
Comparison of phenotypic properties of innate lymphoid cells at various stages of rheumatoid arthritis
Autoimmune diseases currently take a leading place in terms of frequency of occurrence in the population, among which 1 percent is occupied by rheumatoid arthritis (RA). Remission in this type of disease is extremely rare and requires constant use of pharmacotherapy. Studying the pathogenesis of RA is necessary to study to search for new drug targets. It is known that T helpers 1 (Th) and Th17 are involved in the development of RA. However, some researchers suggest that ILCs play a role in the development of RA. ILCs are “innate analogues” of Th, due to the fact that this subpopulation synthesizes the same cytokines. ILC1 is innate analogs of Th1, ILC2-Th2, ILC3-Th17. ILCs are tissue-resident innate lymphoid cells that have functional diversity and regulate the direction of the immune response through the production of cytokines.We used peripheral blood mononuclear cells (PBMCs) from patients (n = 19) and conditionally healthy donors (n = 10) as material. The group of patients was divided biologic disease-modifying anti-rheumatic drugs (bDMARDs) and Metotrexate (MTX) and of stage of RA (early and very early arthritis, advanced and late). PBMCs were stained with monoclonal antibodies. ILCs were identified as Lin-CD127+, CD294+ILCs (ILC2) were measured in the general population, CD117-CD294-ILCs were identified as ILC1, and CD117+CD294-ILCs were identified as ILC3.We obtained the following results: ILC1 was significantly reduced in patients treated with MTX comparison with patients on bDMARDs and healthy donors. However, patients on MTX with advanced RA had low levels of ILC2 and ILC3 compared to patients on bDMARDs. ILC2 significantly increased in patients with early stages of RA comparison with patients with advanced RA. However, ILC1 was significantly reduced in patients treated with MTX, and ILC3 increased significantly in patients treated with MTX comparison with bDMARDs. Expression of PD1 on ILC1 was increased compared to patients treated with bDMARDs. However, ILC3 patients with advanced stages on MTX had increased expression of PD1 comparison with patients taking bDMARDs. The ILC3 of donors was significantly increased comparison with patients on bDMARDs
EFFECT OF DEXAMETHASONE ON INTERFERON-α-INDUCED DIFFERENTIATION OF MONOCYTES TO DENDRITIC CELLS
Type I Interferons are potent inducers of monocyte’s differentiation into dendritic cells (DCs). However, sensitivity of these DCs to tolerogenic effect of glucocorticoids has not been previously investigated. The aim of this study was to investigate the effect of dexamethasone upon maturation and functions of interferonalpha-induced DCs (IFN-DC) derived from healthy donors. DCs were generated from blood monocytes cultured for 5 days with GM-CSF and IFNα, in absence or with addition of dexamethasone (10-6 M), applied on the 3rd day. Addition of dexamethasone inhibited IFN-DC maturation, which manifested with increasing numbers of CD14+ cells and decreased percentage of CD83+ DCs. Dexamethasone did not significantly influence HLA-DR, CD86 and B7H1 expression. However, it caused a 2-fold increase of tolerogenic TLR-2 molecule expression. Along with suppression of IFN-DC maturation, dexamethasone inhibited production of proinflammatory/Th1 cytokines (TNFα, IL-1, IL-2, IFNγ, IL-12), and some chemokines (MIP-1α, RANTES). Dexamethasone-treated IFN-DCs exhibited a 2-fold lower allostimulatory activity in mixed lymphocyte culture (MLC). Worth of note, the capacity of IFN-DCs to stimulate T cell proliferative response in allo-MLC showed direct correlation with CD83 expression on DCs, and an inverse correlation with CD14 and TLR-2. Evaluation of Th1/Th2-polarizing activity of IFN-DCs showed that dexamethasone exerted a pronounced inhibitory effect upon ability of DCs to stimulate T cells for IFNγ production, along with lowgrade suppressive effect upon ability of DCs to induce IL-6 production, thus being indicative for a dominance of Th2-polarizing activity of IFN-DCs under the influence of dexamethasone. In general, the data obtained show that IFN-DCs are sensitive to tolerogenic action of dexamethasone, and, hence, the IFN-DCs may mediate the immunomodulatory effect of glucocorticosteroids and represent novel candidate cells for the development of therapeutic tolerogenic DC-based vaccines applicable for management of autoimmune disorders
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