44 research outputs found

    Activated sintering of ceramics on the basis of Al[2]O[3]

    Get PDF
    Ceramic sintering on the basis of Al2O3 activated by nanopowder additives Al[2]O[3] and Al has been studied. The given paper shows that adding nanopowder Al[2]O[3] in the amount of up to 20 wt. % into the coarse powder [alpha]-Al[2]O[3] activates the sintering process and, as a result, leads to the increase in density and microhardness of sintered alumina ceramics. The study has revealed a significant effect of alumina ceramic density growth which is due to introducing the submicron powder TiO[2] to the initial blends composition

    Serotonin and Dopamine Protect from Hypothermia/Rewarming Damage through the CBS/ H2S Pathway

    Get PDF
    Biogenic amines have been demonstrated to protect cells from apoptotic cell death. Herein we show for the first time that serotonin and dopamine increase H2S production by the endogenous enzyme cystathionine-β-synthase (CBS) and protect cells against hypothermia/rewarming induced reactive oxygen species (ROS) formation and apoptosis. Treatment with both compounds doubled CBS expression through mammalian target of rapamycin (mTOR) and increased H2S production in cultured rat smooth muscle cells. In addition, serotonin and dopamine treatment significantly reduced ROS formation. The beneficial effect of both compounds was minimized by inhibition of their re-uptake and by pharmacological inhibition of CBS or its down-regulation by siRNA. Exogenous administration of H2S and activation of CBS by Prydoxal 5′-phosphate also protected cells from hypothermic damage. Finally, serotonin and dopamine pretreatment of rat lung, kidney, liver and heart prior to 24 h of hypothermia at 3°C followed by 30 min of rewarming at 37°C upregulated the expression of CBS, strongly reduced caspase activity and maintained the physiological pH compared to untreated tissues. Thus, dopamine and serotonin protect cells against hypothermia/rewarming induced damage by increasing H2S production mediated through CBS. Our data identify a novel molecular link between biogenic amines and the H2S pathway, which may profoundly affect our understanding of the biological effects of monoamine neurotransmitters

    Primjena i kompozicija individualiziranih zaštitnih elemenata linijske grafike u projektiranju novčanica

    Get PDF
    Proces stvaranja novčanica je dugotrajan i složen, što rezultira kompleksnim rješenjima koja predstavljaju pravo remek djelo grafike. Novčanice su prožete brojnim detaljima i prenose različite informacije koje se analiziraju u teorijskom dijelu rada. Prvotno se postavljaju kriteriji po kojima se izrađuje detaljna analiza velikog broja zaštitnih i konceptualnih elemenata na primjerima novčanica. Time je prikazan okvirni povijesni pregled razvoja novčanica i utjecaji kojima je bio izložen. Analizira se međuovisnost dizajna o sigurnosnim značajkama, te se ispituje razina informiranosti javnosti o zaštitama na novčanicama. Zaključuje se koje metode zaštite su najučinkovitije, te kako šira javnost najčešće provjerava autentičnost novčanica. U eksperimentalnom dijelu rada se na temelju donesenih zaključaka iz teorijskog dijela izrađuje prototip novčanice koja je u najvećoj mjeri prožeta individualiziranim PostScript programskim rješenjima elemenata linijske grafike (rozete, mikrotekst, zaštitne linije, brojevi apoena), a od ostalih zaštita modeliran je individualizirani raster transformacijom matematičkog izraza u PostScript programski kod. Sve ostale zaštite tipične za novčanice simulirane su alatima za rastersku i vektorsku grafiku. U radu se ispituje utjecaj kompozicije zaštitnih elemenata na prepoznavanje autentičnosti novčanica, te efikasnost samih individualiziranih programskih rješenja

    Gamma rays and neutrons from239Pu fluorides

    No full text

    Interconnection at the level of uric acid and apolipoprotein e in the blood of persons with normal and hyper lipidemia

    No full text
    To investigate the levels of uric acid and apoE in patients with normo- and hyperlipidemia. The serum lipids, apolipoproteins and uric acid levels were measured with Chronolab (Switzerland) kits in 78 patients: 53 patients with normolipidemia and 25 patients with hyperlipidemia of type IIa and IIb. Significantly higher levels of apo-E were registered in patients with hyperlipidemia than in patients with normolipidemia, but there were no differences in content of uric acid. A comparative correlation analysis detected a significant correlation between uric acid and apoE levels in both groups but in normolipidemic patients the correlation was positive while in hyperlipidemic patients it was negative. Hyperlipidemia provokes inversion of correlation between the levels of uric acid, apoE and apoC3. A rise of apoC3 may serve an adaptive mechanism of inhibition of apo-E induced hyperlipidemia

    Development of Thermal Installation on the Basis of the Cascade Heat Pump for Ensuring All Thermal and Refrigerating Needs of the Consumer

    Full text link
    This article describes the developed and manufactured multifunctional heat point, which allows to supply heat and refrigeration energy to consumers. For effective operation, the heat point contains an automated control system that allows to direct heat flows in an optimal way. Development of this thermal point began because in Russia there are no complex researches on creation of systems of power supply on the basis of heat pumps now. There are some works which actually copy the western technologies. At the same time, features of climatic zones are not considered that is extremely important for the development of similar power stations. That is, earlier nobody created a product which equally well works in the conditions of the Southern regions and Far North. Thermal and hydraulic calculations of thermal point were executed. Coefficients of performance and resistance of the contours of the heat pumping plant were the results of these calculations. These calculations showed that the transformation coefficient on all contours is in the range from3.352 to 4.884. Now starting tests of the thermal point which showed a regularity of the chosen design decisions and operability of the installation are carried out.The received results will be useful at projection of similar systems as the main characteristics of cascade heatpumping plants are received by a calculated path.The concrete received results of a research are as follows:– the multipurpose thermal point allowing to carry out heating – 25 kW, hot water supply – 5 kW, conditioning – 16 kW, ventilation of 25 kW is developed;– key indicators of thermal effectiveness of the power station, such as transformation coefficient, thermal rating etc are defined;– capacity of compact accumulators of warmth is determined. Heating with the temperature of 35 оС, within 12 hours of night-time requires the boiler tank of 2500 l whereas the accumulator on change phase of 300–500 l;– on the basis of the analysis of available renewable and secondary energy sources the structure of heat fluxes of the standard consumer with sources of excess warmth and points of its consumption is develope
    corecore