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Speciation analysis of selenium compounds
Kramulová, Barbora ; Rychlovský, Petr (advisor) ; Šíma, Jan (referee)
Previously, selenium was known as an element with negative properties. However, in the last century, the significant positive effects on human health were detected. Currently, the function, behavior and toxicity of selenium are still not well known. The key to understand it is to do speciation analysis. The aim of this diploma thesis is to develop method for determination inorganic (sodium selenite and selenate) and organic (selenourea, selenocystine, selenomethionine) selenium compounds. Parameters of apparatus for electrochemical hydride generation with atomic absorption spectrometry detector were optimized, final conditions were set and optimal conditions for separation process using HPLC were investigated. Calibration dependences for selenium compounds were measured and analytical figures of merit were investigated. In conclusion, a coupled method HPLC- EcHG- QFAAS for determination of individual selenium compounds was proposed, and it was tested on urea samples. Calibrations for these measurements were investigated and analytic characteristics were calculated. Based on these comparisons it can be said that proposed method allows the determination of selected selenium compounds in both aqueous and urea matrices. Subject words: Spectroscopy, analytical chemistry Key words: Atomic absorption...
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Dissecting the role of GPR55 agonist lysophosphatidylinositol in mechanically evoked pain
Škoricová, Dagmar ; Pávek, Petr (advisor) ; Mladěnka, Přemysl (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Dagmar Škoricová Supervisors: Prof. Dr. Rohini Kuner Doc. PharmDr. Petr Pávek, Ph.D. Title of diploma thesis: Dissecting the role of GPR55 agonist lysophosphatidylinositol in mechanically evoked pain Recent studies have suggested that the orphan receptor GPR55 (G-protein coupled receptor 55) is possibly a novel cannabinoid receptor activated by multiple different cannabinoid ligands and also by the lysophospholipid L-α-lysophosphatidylinositol (LPI). GPR55 is reported to be expressed on sensory neurons and mice lacking GPR55 were shown to have reduced mechanical hypersensitivity in inflammatory and neuropathic pain models, suggesting a pronociceptive role of GPR55. LPI was found to be secreted in large quantities from varieties of cancer tissue. These facts led us to speculate that LPI released from cancer cells could sensitize nociceptors and thereby lead to cancer-induced pain. The aim of the study was to investigate the role of LPI in cancer induced, mechanically evoked pain and its possible underlying mechanism. We found that the dorsal root ganglion neurons are directly activated by LPI in vitro. We also found that LPI injected in the periphery leads to a mechanical...
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The atorvastatin effect on endoglin expression in atherosclerotic plaques.
Neumanová, Zuzana ; Nachtigal, Petr (advisor) ; Štaud, František (referee)
Zuzana Neumanová The atorvastatin effect on endoglin expression in the atherosclerotic plaques. Diploma thesis Charles University in Prague, Faculty of Pharmacy in Hradec Králové Pharmacy Background: We observed the expression of endoglin in atherosclerotic plaques in Apo E/LDL receptor deficient mice with regard to the atorvastatin treatment. Methods: We used C57BL/6J mice with double deficiency of apolipoprotein E and LDL receptor. Animals were divided into two groups and both groups were fed with special diet containing either 1 % of cholesterol or cholesterol with atorvastatin at a dose of 50 mg/kg/day. Biochemical analysis of blood samples was performed. Histological staining with oil was performed for the determination of lipids in atherosclerotic lesions. The immunohistochemical analysis of aortic sinus was also performed. Expression of the endoglin was detected using the Avidin-Biotin method (ABC). Results: Atorvastatin treatment resulted in a significant decrease of total, VLDL and LDL cholesterol in comparison with the control group. Histological staining with oil red demonstrated the presence of the atherosclerotic lesions in both groups of animals. Atorvastatin treatment reduced the lesion size area staining when compared to control group. Immunohistochemical analysis showed stronger...
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Determination of electrophoretic mobility of alkaline cations in micellar systems
Müllerová, Ludmila ; Gaš, Bohuslav (advisor) ; Kašička, Václav (referee)
Micellar electrokinetic chromatography is a widely used analytical separation technique. To achieve separation, it uses interaction of analytes with charged micelles present in the background electrolyte (BGE). Not only the mobilities of analytes but also mobilities of small inorganic ions, usually contained in the BGE, are influenced by the presence of micelles. Description of interactions between inorganic ions and micelles is needed for better understanding electrophoretic separations in BGEs containing micelles. Determination of physico-chemical constants (interaction constants, mobilities of complexes) by capillary electrophoresis is based on accurate determination of effective mobilities. For this reason, accurate determination of mobility of electroosmotic flow (EOF) is also necessary but complicated in BGEs containing charged micelles, because the neutral EOF marker can be mobilized by interaction with the micelles. In this work a new two-detector method for determination of effective mobility in interacting BGEs was proposed. In this method the analyte is placed in the BGE containing charged micelles, while the marker zone is in the BGE without micelles and so the possible interaction is avoided. Using this method, dependence of sodium cation mobility on concentration of lithium...
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Exctretion of urinary N7 guanine and N3 adenine DNA adducts in mice after inhalation of styrene
Mikeš, Petr ; Mráz, Jaroslav (referee)
Adenine adducts of styrene : 3-(2-hydroxy-1-phenylethyl)adenine (N3αA) and 3-(2-hydroxy-2- phenylethyl) adenine (N3βA), were found in the urine of mice exposed to styrene vapor. Vast majority of styrene is metabolized to styrene -7,8-oxide. This reactive molecule is futher bio transferred either to mandelic and phenylglyoxalic acid or bounds to nucleophilic sites in biomolecules. Adducts of styrene oxide with amino acids contained in proteins and with purine and pyrimidine bases of nucleic acid were observed during in vitro tests. These styrene-7,8-oxide derived adenine adducts, as well as previously identified guanine adducts, 7-(2-hydroxy- 1- phenylethyl)guanine (N7αG) and 7-(2-hydroxy-2-phenylethyl)guanine (N7βG) were quantified by HPLC-ESI-MS2 and the excretion profile during and after repeated exposure to 600 mg.m-3 or 1200 mg m-3 of styrene for 10 consecutive days (6 h/day) was determined. The excretion was dose dependent. Total excreted amount of N3 adenine adducts (N3αA+N3βA) represents 0.8 ×10−5 % of the absorbed dose, while overall sum of N7 guanine adducts (N7αG+N7βG) yields about 1.4 ×10−5 % of the dose. No accumulation of the adducts was observed. Due to rapid depurination of the DNA, the excretion of both N3 adenine and N7 guanine adducts ceased shortly after finishing the exposure. Both N3...
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The Speciation Analysis of the Toxicological Important Forms of the Arsenic in Urban Particulate Matter Samples with the Detection QF-AAS
Jelínek, Petr ; Rychlovský, Petr (advisor) ; Červený, Václav (referee)
The topic of this diploma thesis was the speciation analysis of the toxicological important forms of the arsenic in urban particulate matter samples. The detection technique used in this work was atomic absorption spectrometry with quartz atomizer. Acetic acid, ammonium acetate, hydroxylamine, potassium hydroxide and sodium carbonate are recommended leaching agents for extraction of metals from urban particulate matter samples. Results of the presenting work are following: Acidic extraction reagents can be not recommended for the speciation analysis of the arsenic, because these reagents lower sensitivity of the determination of As3+ and As5+ too and destroy the quartz atomizer. Alkaline extraction reagents don't lower sensitivity of the determination of As3+ and these reagents don't destroy the atomizer, but lower sensitivity of the determination of As5+ was obtained. Recommended reagents aren't useful for extraction of the metals from urban particulate matter samples for the speciation analysis.
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Porphyrazine film for use in electrochemical sensor
Merhoutová, Jana ; Nesměrák, Karel (advisor) ; Ludvík, Jiří (referee)
Porphyrazine film for use in electrochemical sensor Abstract: A water soluble N,N',N'',N'''-tetramethyltetra-3,4-pyridinoporphyrazine complex containing cobalt cation (II) as a central atom was used like a mediator for preparation of electrochemical sensor. Such effects on a sensor function like an electrode carrier material, the manner of porphyrazine deposition, pH and thickness of the layer, were studied by cyclic voltammetry method. The sensor was tested for hydrogen detection in water buffer solution consequently.
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Measurement of spray characteristics using optical measurement methods
Ďurdina, Lukáš ; Otáhal, Jan (referee) ; Jedelský, Jan (advisor)
Diplomová práce se zabývá měřením charakteristik sprejů dvou tlakových vířivých trysek pro spalovací komoru malého turbínového motoru na zkušebním stavu za studena pomocí metod Particle Image Velocimetry (PIV) a fázové Dopplerovské anemometrie (PDA). Cílem měření bylo stanovit a porovnat charakteristiky sprejů obou trysek. Výsledky měření mají objasnit rozdílnost chování trysek za provozu a možný dopad na proces spalování. Úvodní teoretická část pojednává o základních fyzikálních principech atomizace kapalin, konstrukci a oblasti uplatnění tlakových vířivých trysek a o principech laserových diagnostických metod použitých při experimentálním měření. Nasledující část popisuje návrh a montáž zkušební trati a dalších zařízení navržených pro experimentální měření v této práci. Experimentální část se zabývá nastavením parametrů měřícího systému a zpracováním dat. Výsledky měření zahrnují vektorová rychlostní pole, axiální rychlostní profily a distribuce velikosti kapek pro různé provozní podmínky obou trysek.
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Determination of kadmium content in plant tissue of Norway Spruce and European Beech after application of cadmium oxide nanoparticles
Svozilová, Eva ; Mikuška,, Pavel (referee) ; Večeřa, Zbyněk (advisor)
The aim of this thesis is to monitor cadmium content in needles of Norway spruce and European beech leaves after controlled exposure to cadmium oxide nanoparticles and evaluate the potential risks of such nanoparticles to plants. Needles and leaves were harvested after a one-week and two-week exposure and prior to analysis of cadmium content, they were modified using relevant procedures. Samples were mineralized in nitric acid using pressurized microwave mineralizer and subsequently analyzed by atomic absorption spectrometry (AAS) with electrothermal atomization of cadmium content. Based on the results AAS analysis the transport of nanoparticles into the plant tissue of studied species was evaluated, comparing the content of cadmium in one week and two weeks experiment in the washed and unwashed samples of needles and leaves.
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