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Resistance of Trichomonas vaginalis and other anaerobic pathogens to metronidazole
Havelka, Michal ; Tachezy, Jan (advisor) ; Rada, Petr (referee)
The aim of this bachelor thesis is to desbribe mechanisms of resistance to metronidazole in three anaerobic eukaryotic pathogens (T. vaginalis, G. intestinalis, E. histolytica). Diseases caused by these pathogens belong to the list of important but currently neglected diseases. Metronidazole acts only on microbes with an anaerobic metabolism. The drug enters the cell by passive diffusion and needs to be activated by reduction of the nitro group. Mechanisms of activation are different for every pathogen. Enzymes bound with energetic metabolism in hydrogenosomes, cytosolic thioredoxin reductase and nitroreductases play a major role in the activation. The drug damages cells in three ways - DNA damage, formation of covalent bonds with proteins, and covalent bonds with thiols. Pathogens have specific mechanisms to defend themselves against the drug. They can either down-regulate enzymes that activate metronidazole, reduce it to non-reactive aminoimidazole or they can increase the intracellular concentration of oxygen which leads to deactivation of the drug by futile cycling. These mechanisms are bound with physiological changes and subsequently with lowered viability of these pathogens. Furazolidone and benzimidazole derivatives are the best candidates to become an alternative to metronidazole for the...
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Roll assembly system for automatic strapping
Havelka, Michal ; Marek, Tomáš (referee) ; Knoflíček, Radek (advisor)
This bachelor’s thesis is dealing with the design of system for rolls of technical textiles, which assembles them into horizontal layer. Possible structural drafts are mentioned here and one selected draft is solved. For the first I am dealing with major dimensions, the choice of rollers, calculation of the required engine power and the calculation of the chain drive. Finally I calculated pneumatic cylinders and checked the deflection of used rollers.
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Determination of Low Concentrations of Cationactive Tenzides in Water Samples using Flow Injection Analysis Technique with Spectrofluorimetric Detection
Havelka, Michal ; Rychlovský, Petr (advisor) ; Červený, Václav (referee)
This thesis was focused on a development of sensitive determination of cationactive tenzides by using the flow injection analyses with spectrofluorimetric detection. The determination was based on an interaction of cationactive tenzides with sodium salt of 4,5,6,7-tetrachloro-2',4',5',7'- tetraiodofluorescein dye (Bengal red) that generates a soluble associate in water environs. The sodium salt of 4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein is a fluorescence-active compound. A decrease of fluorescence intensity is detected as a result of the formation of fluorescence-inactive associate. A development of the determination proceeded in two steps. At first a static method of the determination was developed. Cetyltrimethylammonium bromide (CTAB) and N-(α-karbethoxypentadecyl)trimethyl ammonium bromide (Septonex) were used as a standard for cationactive tenzides. An optimal theoretical concentration of Bengal red dye (5.10-5 mol/l) was found, an optimum rate of pH for the fluorescence of Bengal red dye (pH = 9) was found, and a suitable kind of buffer for the environs of the interactions (25 mM phosphate buffer) was found. A linear dynamic range for the determination (Septonex) was in the interval: the limit of quantification - 7.10-5 mol/l. The limit of quantification was 3,72.10-6 mol/l. Next...
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Uneployment Solution in Selected District
Ondříšek, Roman ; Havelka, Michal (referee) ; Sojka, Zdeněk (advisor)
The main aim of this bachelor work is focusing on unemployment between 2009 and 2013 concentrated on territory of Kyjov and its neighbourhood. Furthermore, it analyzes the level of unemployment referring to the European union, the Czech republic and another territory chose by me, where is again analyzed the rate of unemployment according to various categories. Finally, solutions for reducing unemployment and improving the labour market situation are suggested.
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Network mobility in Mobile IP
Havelka, Michal ; Novotný, Vít (referee) ; Skořepa, Michal (advisor)
his semestral thesis is focused on issue network mobility (NEMO) beeing extension of protocols Mobile IPv4 and Mobile IPv6. It describes basic principle function of protocols Mobile IP, defines differences between mobility of nodes and mobility of network and suggest various situations, which may occur in combination these two protocols. Further, it describes differences between basic protocol network mobility (RFC 3936) for IPv6 and it’s extension (RFC 5177) for IPv4. Practical part of work consist in simulation network mobility in application OPNET Modeler and discussion of results, which has been discovered on the base of this simulation.
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Patch antenna with switchable polarization
Havelka, Michal ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
The bachelor’s thesis deals with the analysis of basic planar antennas, the design methods, optimization and simulation in ANSOFT Designer. Attention is turned to the design of aperture coupled microstrip antennas. First, the antenna with a simple slot is designed. Second, the design of the ring slot coupled microstrip antenna is described. Both the antennas are designed for the operation frequency 2,45 GHz. The second part is devoted to the antenna with switchable polarization. Using three PIN diodes powered by lithium battery of 3-V, the linear polarization (both the horizontal one and the vertical one) and the circular polarization (both the right-hand one and the left-hand one) can be switched. The results were verified by experimental verification.
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Administration of digital library
Havelka, Michal ; Balej, Jiří (referee) ; Číka, Petr (advisor)
The diploma thesis is focused on problematic of management of digital libraries, more precisely it’s focused on standard MPEG-7 ISO/IEC 15938. The thesis defines description of multimedia content, its basic rules and more deeply it describes work with static visual data. The practical part of the thesis is focused on creating standalone application in programming language Java. Its purpose is using XML files to manage, save, search and for general work with visual data and its parameters. An application is focused on Scalable Color and Dominant Color descriptors and propose alternative calculation procedure by variable parameters.
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Planar antenna array for receiving the digital tv signal
Havelka, Michal ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The master’s thesis deals in first part with the design of a single antenna element of an antenna array for receiving the digital TV. The resonant frequency of the antenna is 4.7 GHz, the antenna operates in the frequency band 4.4 to 5.0 GHz. Properties of the antenna are verified in programs CST Microwave Studio and Ansoft Designer. The final antenna element is experimentally produced. The second part is devoted to microstrip divider, 2x2 elements antenna array and 4x4 elements antenna array. The antenna array 4x4 elements was produced and its properties were measured.
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The efficiency of the anionactive surfactants degradation in a constructed wetland vegetation bed.
HAVELKA, Michal
This bachelor thesis is focused on the validation of the anionactive surfactants spectrophotometric determination method. Data from the seasonal monitoring of the anionactive surfactants in a constructed wetland for wastewater treatment with a horizontal subsurface flow were used for the anionactive surfactants degradation efficiency determination and for the determination of the relationship of the wastewater inflow, the constructed wetland´s water temperature, and the constructed wetland´s water redox potential to the degradation efficiency. The spectrophotometric method of the anionactive surfactants determination with methylene blue was used during the study.
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