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Cable supported bridge
Kolář, David ; Koláček, Jan (referee) ; Nečas, Radim (advisor)
The topic of this bachelor thesis is design of a footbridge across a river. The final version, which has been chosen from three designs differentiating in their static behaviour of the structure, is a cable-stayed footbridge. The chosen option is designed as a parabolic monolithic prestressed deck suspended by cables anchored to two cone shaped pylons. The structure is situated perpendicularly to the riverbed and its total length is 57,465 m. Softwares, such as SCIA Egineer 20.0 and MS Excel, were used for the calculations of internal forces and modelling calculation models and its verification by hand. The design of the prestressing force, assessment of utility limit state and serviceability limit state were done by hand according to valid standards and regulations. Partially simplified bearing capacity assessment of the pylons was solved by IDEA StatiCa 9 software and some of the results were verified by hand as well. The thesis disregards stages of construction and prestress losses are estimated.
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Design of ATC System
Kolář, David ; Tůma, Jiří (referee) ; Blecha, Petr (advisor)
The first part of the thesis is focused on summarisation of commonly used conceptions of automatic tool change systems, especially focused on milling machines. Special attention is given to the issue of single tool change systems using storage tool magazines. Considering the following construction theme of the thesis, most commonly used spindle clamping units were described. With use of the gathered information was then created the construction draft of the ATC system suitable to be used with a numerically controled milling machine. Solution of the issue consists of the static structural analysis of the clamping unit using the finite element method and design of the belleville springs set. Final output of the draft comprises of drawing documentation of the main parts of the system.
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Design of the gantry CNC milling machine with sliding table
Kolář, David ; Holub, Michal (referee) ; Pavlík, Jan (advisor)
This master’s thesis is focused on design of gantry CNC milling machine with sliding table. Thesis includes the review of components of this machines and comparsion of their options. Servo motors , ball screws and linear guides parameters are calculated. Also the suitable software and hardware for the machine control is chosen. Main parts of the machine were analysed using finite elements method. 3D model, drawings and documentation of machine build are included.
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Effect of caloric restriction on neuroplasticity
Sonina, Alisa ; Málková, Petra (advisor) ; Kolář, David (referee)
Calorie restriction has been shown to have a wide range of beneficial effects on health and longevity, although its effects on brain function are not as well known. This paper reviews the current state of research on the effects of calorie restriction on neuroplasticity, including studies examining the molecular, structural, and behavioral effects of dietary restriction in animal and human models. Overall, the evidence suggests that caloric restriction promotes neuroplasticity. However, further research is needed to fully understand the mechanisms underlying these effects and to determine the optimal duration and intensity of caloric restriction. Key words: Caloric restriction, neuroplasticity, diet, cognition, neurogenesis, metabolism
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Disorders of brain energy metabolism in Alzheimer's and Parkinson's disease
Řezáčová, Adéla ; Telenský, Petr (advisor) ; Kolář, David (referee)
Alzheimer's and Parkinson's diseases belong to group of neurodegenerative diseases that affect not only the patients, but also their surroundings. Patients of those diseases gradually lose their neurons. Both disorders are typical for pathophysiological accumulation of proteins which affect the functioning of neurons and astrocytes. These disorders are also characterised by mitochondrial senescence and its damages which itself manifest by dysfunction of various complexes. Furthermore, in both diseases, there can be found insulin resistance, which leads to an insufficient insulin signalization. Both diseases are also accompanied by impaired metabolisms of amino acids. With Alzheimer's disease, there is significantly lowered metabolism of glucose, whereas with Parkinson's disease, there is not enough stimulation for action potential to proceed in dopaminergic neurons in substantia nigra. These impairments in Alzheimer's disease cause cognitive dysfunction, while with Parkinson's disease, these defects predominantly lead to complications with motor function. By studying energetic changes in presented diseases could bring more effective treatment.
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Circadian clock and detoxication processes in the liver
Ludvíková, Tereza ; Pačesová, Dominika (advisor) ; Kolář, David (referee)
The circadian system influences almost all physiological processes in the mammalian body. Among other things, detoxication processes in the liver are under circadian control. Both central and peripheral clock in the liver regulate the expression of genes involved in the detoxication of xenobiotic substances and drugs. The first part of this thesis summarizes the main characteristics of the central and peripheral circadian clocks, including their molecular basis. The second part focuses on the main functions of liver tissue with a focus on detoxification processes. The emphasis of the third section is on circadian rhythms in the expression and activity of enzymes called cytochromes P450, which are the most important system catalyzing phase I detoxication, and also briefly discusses the influence of the circadian system on the expression of nuclear receptors and PAR bZIP transcription factors involved in the regulation of cytochrome P450 transcription. The last section describes the influence of the circadian system on the efficacy and toxicity of selected drugs, on paracetamol metabolism with the main purpose of describing how paracetamol-induced hepatotoxicity is affected by time of administration. Key words: circadian system, liver, detoxication, cytochrome, paracetamol
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Footbridge across the river Opava
Kolář, David ; Romportl, Tomáš (referee) ; Nečas, Radim (advisor)
The master´s thesis topic is design of a footbridge across Opava river. Out of two different designs, a self – anchored suspension footbridge was chosen and necessary documentations wer produced. The primary focus of the thesis is on static design solution with an output of several drawings. The model created in ANSYS includes different load cases together with construction stages. To support the results, checks and hand calculations via MS Excel were completed, as well as static analysis of transverse behaviour of the deck using SCIA Engineer software. Analysis and calculations are compliant to up-to-date coades and respect the funfamentals of analysis due to limit states.
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Effect of morphine preconditioning and mKATP channel activity on survival of differentiated SH-SY5Y cell line after oxidative stress
Paluba, Michal ; Hejnová, Lucie (advisor) ; Kolář, David (referee)
Morphine as one of the most effective analgesics has been used in medicine for more than a century. However, morphine is also known for its neuroprotective and cardioprotective effect in ischemic disorders, where it induces increased cellular resistance to oxidative stress. One of the aims of our study was to analyze the effect of chronic morphine treatment on the viability of differentiated cells of the neuroblastoma cell line SH-SY5Y after induction of oxidative stress by tert butyl hydroperoxide (tBHP). However, the detailed mechanism of the protective effect of morphine is still unknown. Current research on this topic, and in particular on morphine-induced preconditioning, has focused much attention on mitochondrial ATP- sensitive potassium channels (mKATPs). There is evidence that morphine, through activation of opioid receptors, mimics the protective effect of ischemic preconditioning precisely through activation of mKATP channels. Modulation of mKATP channel activity is thought to be responsible for the functional state of the mitochondria by altering mitochondrial membrane potential and regulating reactive oxygen species (ROS) production. Thus, the next aim of our work was to reveal the role of mKATP channels in morphine preconditioning and the effect of their activity on cell survival. The...
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Energetic metabolism of heart during acut and chronic hypoxia
Kolář, David ; Žurmanová, Jitka (advisor) ; Sotáková, Dita (referee)
The heart is a highly oxidative tissue, which far exceeds the oxygen consumption of neurons. The centre of ATP production is therefore in oxidative phosphorylation, which is contributed to by different substrates (glucose, fatty acids and lactate) depending on metabolic conditions. A high proportion of mitochondria in heart tissue carries an increased risk of reactive oxygen species development in the possible disruption of mitochondrial metabolism. Oxygen radicals are generated primarily at complex I and III of the respiratory chain of mitochondria. They may perform a signalling role allowing the heart adaptation to hypoxia, but the high concentration leads to irreversible damage /of cellular structures. This thesis considers the energy metabolism of the heart under normoxic, hypoxic and ischemic conditions, with emphasis on the glucose and fatty acids uptake, and the control of oxidative phosphorylation.
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Brain energy metabolism and its pathologies
Nová, Jana ; Telenský, Petr (advisor) ; Kolář, David (referee)
The brain belongs amongst metabolically most active organs and disturbances of brain energy metabolism are commonly cited as a critical factor predisposing to neurodegeneration. Brain metabolic substrates must be strictly regulated both spatially and temporarily to ensure the energy homeostasis of the brain. Research on energy metabolism of the brain identified several models revealing the interdependence of metabolic processes in the CNS. Powered by TCPDF (www.tcpdf.org)
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