77 research outputs found

    About the Applicability of Bone and Cartilage Acid-free Staining for Anura

    Get PDF
    The article describes the first use of acid-free alcian-alizarin staining for tailless amphibians in comparison with the standard method of acid staining on the example of the moor frog. The acid-free protocol is applicable for Anura and it has a number of advantages, such as the absence of decalcification, safety for the researcher andothers. However, this method also has limitations, such as the binding of alcian blue with soft tissues

    Synthesis of pure hydroxyapatite by ion exchange reaction

    Get PDF
    An ion-exchange reaction for the synthesis of hydroxyapatite (HAP) in a constant alkaline medium using preliminary dry homogenization is proposed in this work. Sodium hydrogen phosphate Na2HPO4, calcium chloride CaCl2 and calcium hydroxide Ca(OH)2 were chosen as precursors. Studies carried out by methods of X-ray phase analysis, scanning electron and transmission microscopy showed that the material obtained is a singlephase hydroxyapatite powder with a Ca/P ratio close to 1.67. It was found that the particles of HAP powder obtained as a result of synthesis with subsequent washing have the shape of needles with a thickness of 10 to 40 nm and a length of 30 to 200 nm. Annealing of the powder at a temperature of 700 °C leads to agglomeration of particles, as well as to rounding of their shap

    Influence of the Mo₁₀Ni₃C₃B phase on the hardness and fracture toughness of Mo-Ni-C-B cermet: experimental and theoretical study

    Get PDF
    We obtained the decreasing of hardness and comparable values of the fracture toughness of Mo₂NiB₂‑Ni cermets due to the formation of Mo₁₀Ni₃C3B phase. To understand the effect of the Mo₁₀Ni₃C₃B phase on the mechanical properties of the cermet, first-principles calculations were applied to investigate the elastic, electronic, and thermodynamic properties of this phas

    Efficiency of Magnetostatic Protection Using Nanostructured Permalloy Shielding Coatings Depending on Their Microstructure

    Get PDF
    The effect of microstructure on the efficiency of shielding or shunting of the magnetic fluxby permalloy shields was investigated in the present work. For this purpose, the FeNi shieldingcoatings with different grain structures were obtained using stationary and pulsed electrodeposition.The coatings’ composition, crystal structure, surface microstructure, magnetic domain structure, andshielding efficiency were studied. It has been shown that coatings with 0.2–0.6μm grains have adisordered domain structure. Consequently, a higher value of the shielding efficiency was achieved,but the working range was too limited. The reason for this is probably the hindered movement of thedomain boundaries. Samples with nanosized grains have an ordered two-domain magnetic structurewith a permissible partial transition to a superparamagnetic state in regions with a grain size of lessthan 100 nm. The ordered magnetic structure, the small size of the domain, and the coexistenceof ferromagnetic and superparamagnetic regions, although they reduce the maximum value ofthe shielding efficiency, significantly expand the working range in the nanostructured permalloyshielding coatings. As a result, a dependence between the grain and domain structure and theefficiency of magnetostatic shielding was found

    Gastrointestinal Bleeding in Antithrombotic Therapy in Patients with Coronary Heart Disease: Risk Factors, Pathogenesis and Treatment

    Get PDF
    Aim. Description of risk factors, pathogenesis and treatment strategies of gastrointestinal bleeding (GIB) in the course of antithrombotic therapy in patients with coronary heart disease (CHD).Key points. Risk factors of GIB during antithrombotic therapy in CHD patients include: GIB, gastric and/or duodenal ulcer in the history, reflux esophagitis, presence of H. pylori, inflammatory bowel disease, diverticula, haemorrhoids, angiodysplasia, gastrointestinal neoplasia, age above 65 years, concomitant treatment with non-steroidal anti-inflammatory drugs (NSAIDs), glomerular filtration rate <50 mL/min, high doses of direct oral anticoagulants (DOACs) ≥3 in HAS-BLED score. Pathogenesis of GIB in the course of antithrombotic therapy is associated with systemic hypocoagulation and local damaging effects of these drugs. Strategies of GIB treatment during DOAC therapy in patients with CHD are determined by severity of bleeding and threat to life. Aside to standard conservative measures, endoscopic or surgical haemostasis requires usage of antidotes to suppress effects of DOACs and other specific drugs in severe cases.Conclusion. GIB associated with antithrombotic therapy in CHD patients poses a serious medical problem of growing importance with wider application of anticoagulant drugs. Antithrombotic therapy requires accurate decision making, risk assessment, careful monitoring of the patient’s condition and timely diagnosis of gastrointestinal disorders following good rationale in GIB prevention

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

    Get PDF
    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

    CLINICAL EFFICACY OF ALBUMIN DIALYSIS THERAPY FOR PATIENTS WITH HEPATORENAL SYNDROME

    Get PDF
    34 patients (23 male, 11 female) in the age of 41–77 years (mean age 59,7 ± 4,2 years) with 2 type hepatorenal syndrome were included in the study. All patients were divided in 3 groups. The 1st group (n = 15) was treated by medical treatment, the 2nd group (n = 12) was treated by medical treatment and hemodiafiltration and the 3rd group (n = 7) – combined treatment with MARS therapy. Outcomes showed that combined therapy with addition of MARS provides positive results in treatment of the patients with 2 type hepatorenal syndrome

    Isostatic Hot Pressed W–Cu Composites with Nanosized Grain Boundaries: Microstructure, Structure and Radiation Shielding Efficiency against Gamma Rays

    Full text link
    Abstract: The W–Cu composites with nanosized grain boundaries and high effective density were fabricated using a new fast isostatic hot pressing method. A significantly faster method was proposed for the formation of W–Cu composites in comparison to the traditional ones. The influence of both the high temperature and pressure conditions on the microstructure, structure, chemical composition, and density values were observed. It has been shown that W–Cu samples have a polycrystalline well-packed microstructure. The copper performs the function of a matrix that surrounds the tungsten grains. The W–Cu composites have mixed bcc-W (sp. gr. Im 3 m) and fcc-Cu (sp. gr. Fm 3 m) phases. The W crystallite sizes vary from 107 to 175 nm depending on the sintering conditions. The optimal sintering regimes of the W–Cu composites with the highest density value of 16.37 g/cm3 were determined. Tungsten–copper composites with thicknesses of 0.06–0.27 cm have been fabricated for the radiation protection efficiency investigation against gamma rays. It has been shown that W–Cu samples have a high shielding efficiency from gamma radiation in the 0.276–1.25 MeV range of energies, which makes them excellent candidates as materials for radiation protection. © 2022 by the authorsLicensee MDPI, Basel, Switzerland.Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2020-926Funding: M.V.S. acknowledges financial support from the Ministry of Science and Higher Education of the Russian Federation within the framework of state support for the creation and development of World-Class Research Centers “Digital Biodesign and Personalized Healthcare” No. 075-15-2020-926

    RESULTS AND PERSPECTIVES OF STUDYING THE OCCUPATIONAL DISEASES IN WORKERS OF AIRCRAFT INDUSTRY IN EAST SIBERIA

    Get PDF
    The materials of the long-studies among the employees working in the aircraft industry, of both the patients with occupational diseases and the practically healthy persons are discussed in the paper. Using the method of the biological feedback for the vibration-induced disease prevention has been grounded. The preliminary results of the experimental studies using the animals are presented in this paper
    corecore