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Machining of precise holes for bearings
Blecha, Jan ; Jaroš, Aleš (referee) ; Kalivoda, Milan (advisor)
This diploma thesis is about machining of exact hole specifications to fit the bearings from the the theoretical overviewof the fiiting. Another purpose is to describe; the overview of machines, the choices in bearings, and the types of gearboxes. Finally, it deals with the different methods of surface finishing, how to produce the holes for the bearings to fit in gearboxes.Finally, it deals with the different methods of surface finishing and how to produce the holes for the bearings to fit in the gearboxes
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Solution to the mechanism of a screw jack
Blecha, Jan ; Osička, Karel (referee) ; Kalivoda, Milan (advisor)
The presented bachelor thesis deals with the mechanism of the screw jack in terms of basic design calculations as well as in terms of production technology. The following part deals with basic division of the workshop lifting equipment, the design of the lifting device and, last but not least, the design of the production technology. Further attention is paid to the technical and economic view of the manufacturing process of the screw jack mechanism and the possibility of improving both the production process and the construction itself.
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The effect of endothelial cell proliferation on susceptibility to mitochondrially controlled apoptosis and oxidative stress.
Blecha, Jan ; Novák, Petr (advisor) ; Plecitá, Lydie (referee)
Mitochondria are multifunctional organelles playing a key role in energy metabolism and cell death induction. Mitochondria, and specifically their respiratory chain, are also the main producers of reactive oxygen species (ROS) in cells. Metabolism can be affected by the state of cellular proliferation and certain ROS-inducing agents have an antiangiogenic effect based on the preferential elimination of proliferating endothelial cells (EC). Therefore, in this work we investigated, whether mitochondria could be responsible for different sensitivity of proliferation and confluent EC to cell death. We mainly focused on systems that regulate ROS level and apoptosis: respiratory chain (ROS production), antioxidant defense (ROS detoxification) and Bcl-2 family of proteins (apoptosis regulation). First, we treated EC with functional and nonfunctional respiratory chain with various oxidative stress- and apoptosis-inducing agents and determined ROS production and susceptibility to apoptosis in proliferating and confluent cells. Our results show that functional respiratory chain greatly increases the susceptibility of proliferating cells to ROS induction and apoptosis, whereas in qiescent cells it protects against cell death. Given these findings, we assessed the activity of respiratory chain in proliferating...
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Sea buckthorn (Hippophae rhamnoides L.) as a source of biochemically active substances
Blecha, Jan ; Hudeček, Jiří (advisor) ; Hodek, Petr (referee)
Sea Buckthorn (Hippophae Rhamnoides L.) as a source of biochemically active substances ABSTRACT This work is primarily focused on summarizing of existing data in the literature about the chemical composition of sea buckthorn (Hippophae rhamnoides L.) fruits, in particular of its oil. It was found that the content of individual chemical components substantially varies in different cultivars and is also very dependent on the conditions in which the plant is grown. Various sea buckthorn products can be rich sources of antioxidants, such as the vitamin C (in amounts up to 2500 mg/100g of fresh fruit) and tocopherols (up to 481 mg/100g of fresh fruit), flavonoids (up to 1100 mg/100g of fresh fruit) and carotenoids (up to 2139 mg/100g of oil). The fatty acids of this plant are mostly unsaturated (up to 89% of all fatty acids), in dominant amounts linolenic and linoleic acid can be found in seed oil and palmitooleic and saturated palmitic acid in pulp oil. Content and effects of significant flavonoids in the plant are also summarized. Among the most important biological effects of sea buckthorn, its antioxidant activity can be included as well as effects on the function of cardiovascular system, hepatoprotective and anticancer effects proven for some of the substances. Thanks to that the sea buckthorn has a high...
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Molecular bases of sensitivity to electron transport chain inhibition-induced cell death
Blecha, Jan
1 Abstract in English Mitochondrial electron transport chain (ETC) targeting shows a great promise in cancer therapy. However, why modern ETC-targeted compounds are tolerated on the organismal level and what are the molecular reasons for this tolerance remains unclear. Most somatic cells are in a non-proliferative state, and features associated with the ETC in quiescence might therefore contribute to specificity. Thus, we investigated the ETC status and the role of two major consequences of ETC blockade, reactive oxygen species (ROS) generation and inhibition of ATP production, in cell death induction in breast cancer cells and in proliferating and quiescent non-transformed cells. First, we characterised the effect of a newly developed ETC inhibitor mitochondria- targeted tamoxifen (MitoTam) in in vitro and in vivo tumour models of breast cancer with varying status of the Her2 oncogene. We document that Her2high cells and tumours have increased assembly of respiratory supercomplexes (SCs) and increased complex I-driven respiration in vitro and in vivo. They are also highly sensitive to MitoTam. Unlike the parental compound tamoxifen, MitoTam efficiently suppressed experimental Her2high tumours without systemic toxicity. Mechanistically, MitoTam inhibits complex I- driven respiration and disrupts respiratory...
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Molecular bases of sensitivity to electron transport chain inhibition-induced cell death
Blecha, Jan
1 Abstract in English Mitochondrial electron transport chain (ETC) targeting shows a great promise in cancer therapy. However, why modern ETC-targeted compounds are tolerated on the organismal level and what are the molecular reasons for this tolerance remains unclear. Most somatic cells are in a non-proliferative state, and features associated with the ETC in quiescence might therefore contribute to specificity. Thus, we investigated the ETC status and the role of two major consequences of ETC blockade, reactive oxygen species (ROS) generation and inhibition of ATP production, in cell death induction in breast cancer cells and in proliferating and quiescent non-transformed cells. First, we characterised the effect of a newly developed ETC inhibitor mitochondria- targeted tamoxifen (MitoTam) in in vitro and in vivo tumour models of breast cancer with varying status of the Her2 oncogene. We document that Her2high cells and tumours have increased assembly of respiratory supercomplexes (SCs) and increased complex I-driven respiration in vitro and in vivo. They are also highly sensitive to MitoTam. Unlike the parental compound tamoxifen, MitoTam efficiently suppressed experimental Her2high tumours without systemic toxicity. Mechanistically, MitoTam inhibits complex I- driven respiration and disrupts respiratory...
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Machining of precise holes for bearings
Blecha, Jan ; Jaroš, Aleš (referee) ; Kalivoda, Milan (advisor)
This diploma thesis is about machining of exact hole specifications to fit the bearings from the the theoretical overviewof the fiiting. Another purpose is to describe; the overview of machines, the choices in bearings, and the types of gearboxes. Finally, it deals with the different methods of surface finishing, how to produce the holes for the bearings to fit in gearboxes.Finally, it deals with the different methods of surface finishing and how to produce the holes for the bearings to fit in the gearboxes
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Molecular bases of sensitivity to electron transport chain inhibition-induced cell death
Blecha, Jan ; Rohlena, Jakub (advisor) ; Brábek, Jan (referee) ; Pecinová, Alena (referee)
1 Abstract in English Mitochondrial electron transport chain (ETC) targeting shows a great promise in cancer therapy. However, why modern ETC-targeted compounds are tolerated on the organismal level and what are the molecular reasons for this tolerance remains unclear. Most somatic cells are in a non-proliferative state, and features associated with the ETC in quiescence might therefore contribute to specificity. Thus, we investigated the ETC status and the role of two major consequences of ETC blockade, reactive oxygen species (ROS) generation and inhibition of ATP production, in cell death induction in breast cancer cells and in proliferating and quiescent non-transformed cells. First, we characterised the effect of a newly developed ETC inhibitor mitochondria- targeted tamoxifen (MitoTam) in in vitro and in vivo tumour models of breast cancer with varying status of the Her2 oncogene. We document that Her2high cells and tumours have increased assembly of respiratory supercomplexes (SCs) and increased complex I-driven respiration in vitro and in vivo. They are also highly sensitive to MitoTam. Unlike the parental compound tamoxifen, MitoTam efficiently suppressed experimental Her2high tumours without systemic toxicity. Mechanistically, MitoTam inhibits complex I- driven respiration and disrupts respiratory...
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The effect of endothelial cell proliferation on susceptibility to mitochondrially controlled apoptosis and oxidative stress.
Blecha, Jan ; Novák, Petr (advisor) ; Plecitá, Lydie (referee)
Mitochondria are multifunctional organelles playing a key role in energy metabolism and cell death induction. Mitochondria, and specifically their respiratory chain, are also the main producers of reactive oxygen species (ROS) in cells. Metabolism can be affected by the state of cellular proliferation and certain ROS-inducing agents have an antiangiogenic effect based on the preferential elimination of proliferating endothelial cells (EC). Therefore, in this work we investigated, whether mitochondria could be responsible for different sensitivity of proliferation and confluent EC to cell death. We mainly focused on systems that regulate ROS level and apoptosis: respiratory chain (ROS production), antioxidant defense (ROS detoxification) and Bcl-2 family of proteins (apoptosis regulation). First, we treated EC with functional and nonfunctional respiratory chain with various oxidative stress- and apoptosis-inducing agents and determined ROS production and susceptibility to apoptosis in proliferating and confluent cells. Our results show that functional respiratory chain greatly increases the susceptibility of proliferating cells to ROS induction and apoptosis, whereas in qiescent cells it protects against cell death. Given these findings, we assessed the activity of respiratory chain in proliferating...
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Solution to the mechanism of a screw jack
Blecha, Jan ; Osička, Karel (referee) ; Kalivoda, Milan (advisor)
The presented bachelor thesis deals with the mechanism of the screw jack in terms of basic design calculations as well as in terms of production technology. The following part deals with basic division of the workshop lifting equipment, the design of the lifting device and, last but not least, the design of the production technology. Further attention is paid to the technical and economic view of the manufacturing process of the screw jack mechanism and the possibility of improving both the production process and the construction itself.
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