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Effect of morphine on the resistance of the heart to ischemia
Mošovská, Linda ; Neckář, Jan (advisor) ; Žurmanová, Jitka (referee)
2. Abstract Opioids are considered as dangerous and addictive substances, mainly due to synthetic opioids such as heroin. It was discovered, that these substances can play an important role in myocardial ischemia because they can limit the damage of the heart tissue that occurs during a heart attack. Since that heart attack is the most common cardiovascular disease, the protective effect is significant. Cardioprotective effect is mainly mediated through δ opioid receptors, but the few studies have shown cardioprotective effect mediated through κ opioid receptors. The protective effect occurs by activation of opioid receptors by their agonists (eg. morphine or TAN-67), either before ischemia (opioid preconditioning) or before reperfusion (opioid postconditioning). The signaling pathway of cardioprotection include mitochondrial KATP channel, Gi/o proteins, protein kinase C, tyrosine kinases and reactive oxygen species.
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The role of mitochondria in cardioprotective effect induced by hypoxia in rat
Lomnický, Matouš ; Žurmanová, Jitka (advisor) ; Hlaváčková, Markéta (referee)
Aerobic organisms need sufficient oxygen supply to maintain homeostasis. These organisms are frequently exposed in hypoxic environments naturally, and also occur in hypoxic states in various pathological conditions. Cardioprotective effect of hypoxia had been recognised more than 30 years ago; and later on, cardioprotective effects of ischemic preconditioning were discovered. Long term exposure to hypobaric hypoxia activates cardioprotective mechanisms, which lower the aftermathes of short term ischemia of myocardia and the effects of further health complications. The core of protective mechanisms has not yet been fully clarified. This work deals with the significance of mitochondria on cardioprotection during hypobaric hypoxia adaptation. This work describes physiological adaptive processes on selected animals on natural hypoxic conditions and also molecular mechanisms, examined on experimental models. Molecular mechanisms of the origins of cardioprotective effects discovered so far, mainly indicate PKC signal pathways through thyrosine kinase and mitogenes of activated kinase and also indicate an activation of sarcKATP-channels and mitoKATP-channels. Opening of these channels can protect mitochondria against a Ca2+ overload, or can lead to an increase in mitochondrial capacity which is possibly connected...
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Algebraic Error in Matrix Computations in the Context of Numerical Solution of Partial Differential Equations
Papež, Jan ; Strakoš, Zdeněk (advisor) ; Ramage, Alison (referee) ; Vejchodský, Tomáš (referee)
Title: Algebraic Error in Matrix Computations in the Context of Numerical Solution of Partial Differential Equations Author: Jan Papež Department: Department of Numerical Mathematics Supervisor: prof. Ing. Zdeněk Strakoš, DrSc., Department of Numerical Mathe- matics Abstract: Solution of algebraic problems is an inseparable and usually the most time-consuming part of numerical solution of PDEs. Algebraic computations are, in general, not exact, and in many cases it is even principally desirable not to perform them to a high accuracy. This has consequences that have to be taken into account in numerical analysis. This thesis investigates in this line some closely related issues. It focuses, in particular, on spatial distribution of the errors of different origin across the solution domain, backward error interpretation of the algebraic error in the context of function approximations, incorporation of algebraic errors to a posteriori error analysis, influence of algebraic errors to adaptivity, and construction of stopping criteria for (preconditioned) iterative algebraic solvers. Progress in these issues requires, in our opinion, understanding the interconnections between the phases of the overall solution process, such as discretization and algebraic computations. Keywords: Numerical solution of partial...
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Selected Extensions of the Albegraic System Octave
Salač, Radek ; Smrčka, Aleš (referee) ; Vojnar, Tomáš (advisor)
This work deals with issues linked to solving system of linear equations in the environment of numerical computer. It describes the fundamental algorithms emphasizing their positive as well as negative sides. The work is devoted to general issues such as time complexity and memory demandingness of given algorithms. In the last part, the process of implementation of selected procedures into the algebraic system Octave is described.
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Evaluation of effectiveness of destress coal blasting fro stress release
Koníček, Petr ; Przeczek, A.
Destress blasting in the coal seam are important active rockbursts measures in conditions of Czech part of the Upper Silesian Coal Basin. Destress coal blasting involves regularly setting off carefully tailored blasts in the fractured coal immediately ahead of a mining face, so as to encourage slip on pre-existing fractures, in order not to allow the accumulation of high strain energy density in the rock mass. In some cases high stress in coal seams (or surrounded rocks) can be reduced. In cases that we demands high stress release we evaluates effect of stress release. Evaluation of stress release is carried out the same procedure without difference between destress blasting in rock and in the coal seam. Paper describes the first analysis of destress blasting in coal seams realised in period 2008 – 2010 (source of seismological databases, about 1200 data). The result of analysis shows of necessity of separate system of stress release evaluation by destress blasting in coal seams and rocks.
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Metoda sdružených gradientů
Segeth, Karel
The endeavour to solve systems of linear algebraic systems is already two thousand years old. In the paper we consider the conjugate gradient method that is (theoretically) finite but, in practice, it can be treated as an iterative method. We survey a known modification of the method, the preconditioned conjugate gradient method, that may converge faster than the original one.
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