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Assessment of impact of arrangement of collagen fibres in arterial wall on its response in tension tests
Kratochvíl, Filip ; Chamrad, Jakub (referee) ; Burša, Jiří (advisor)
This thesis deals with organisation of collagen fibres in human blood vessel walls and with simulation models, which are used to calculate vessel behaviour. Firstly, the thesis focuses on the anatomy of human blood vessel system, mainly on the vessel structure and properties of some vessel components. Next, two models are presented, which can be used for the vessel wall in calculations, specifically models with straight and wavy collagen fibres. Moreover, some methods are described, which can be used to gain information about a vessel. Subsequently, relationships are derived needed for simulation of tension tests of these models, mainly to express the length of collagen fibres. In the practical part simulations of vessel behaviour during uniaxial tension test are carried out and histograms of local direction angles of collagen fibres in the unloaded state are created. In the end, results gained by simulations are compared with real available data.
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The biological significance of changes in the vascular wall and atherosclerotic plaque for the development of atherosclerotic disease of the coronary arteries
Horváth, Martin ; Hájek, Petr (advisor) ; Poledne, Rudolf (referee) ; Kovárník, Tomáš (referee)
Acute complications of atherosclerosis are typically caused by arterial occlusion due to acute thrombosis forming over a ruptured vulnerable atherosclerotic plaque (VP). Early identification of such VP prior to their rupture could help prevent these events. At the same time, methods for assessing cardiovascular risk are focused on measures at the population level and are not sensitive and specific enough to assess the risk of individual patients. We therefore focused on the possibilities of in vivo detection of VP using biomarkers and invasive imaging methods. First, we focused on the detection of microRNAs (miRs), which have been investigated in recent years as promising biomarkers for a number of diseases, including atherosclerosis. We determined miR levels using quantitative polymerase chain reaction in peripheral venous blood samples from patients in very early phase of ST-elevation myocardial infarction (STEMI), which served as the closest clinical model of acute VP rupture. The results led to the identification of two miRs (miR-331 and miR-151-3p) that were deregulated in STEMI and could be biomarkers of VP. In the next part of the research, we dealt with the possibilities of invasive imaging of VP using intravascular ultrasound and near- infrared spectroscopy (IVUS and NIRS). We confirmed...
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Assessment of impact of arrangement of collagen fibres in arterial wall on its response in tension tests
Kratochvíl, Filip ; Chamrad, Jakub (referee) ; Burša, Jiří (advisor)
This thesis deals with organisation of collagen fibres in human blood vessel walls and with simulation models, which are used to calculate vessel behaviour. Firstly, the thesis focuses on the anatomy of human blood vessel system, mainly on the vessel structure and properties of some vessel components. Next, two models are presented, which can be used for the vessel wall in calculations, specifically models with straight and wavy collagen fibres. Moreover, some methods are described, which can be used to gain information about a vessel. Subsequently, relationships are derived needed for simulation of tension tests of these models, mainly to express the length of collagen fibres. In the practical part simulations of vessel behaviour during uniaxial tension test are carried out and histograms of local direction angles of collagen fibres in the unloaded state are created. In the end, results gained by simulations are compared with real available data.
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