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Ecotoxicological Evaluation of Polymers and Biologically Active Substances in Aquatic Environments
Kašpar, Otakar ; Beklová, Miroslava (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Vávrová, Milada (advisor)
To determine the ecotoxicity of analgetics, first the individual ecotoxicity values of individual analgetics are determined and then a mixture of two analgetics is tested. To determine the toxicity, both standard and alternative toxicity tests are used (daphnia magna, sinapsis alba, scenedesmus subspicatum, vibrio fischeri, thamnotoxkit FTM a daphnotoxkit FTM magna). The analgetics being whish tested are the commonly used medicines ibuprofen, ASA, diclofenac and paracetamol, which are the most frequently used medicines in the Czech Republic and whole Europe. To determine the ecotoxicity of the polymers, I‘m using an indirect method of examination, in which I determine the antagonistic or synergistic effects of the mixture of monomers from which the polymer is prepared and into which it slowly decomposes in nature. For the determination both standard and alternative toxicity tests are used. The polymers the toxicity of which is being determined are the habitually used polymer PET and the formaldehyde resine known as bakelite in Eastern Europe.
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Use and limitations of laser ablation ICP-MS in geoscience applications
Míková, Jitka ; Košler, Jan (advisor) ; Kanický, Viktor (referee) ; Anczkiewicz, Robert (referee)
This dissertation contributes to applications of laser ablation plasma source mass spectrometry (LA ICP-MS) in Earth sciences. The primary goal of the thesis is to address some of the fundamental processes related to laser ablation of solid samples that result in decoupling of elements during laser ablation ICP-MS analysis. Better understanding of mechanisms that cause the elemental fractionation and matrix effects is necessary before the accuracy and precision of laser ablation ICP-MS analyses can be improved. The chemical and phase compositions of particles produced by laser ablation (266 nm Nd:YAG) of silicate NIST glasses and zircon were studied by SIMS and HR-TEM techniques with a particular focus on Pb/U fractionation. This is of great importance in geology as the Pb/U elemental fractionation hampered the precision and accuracy of the measured accessory mineral ages. The data suggest that chemical composition and mineralogy of particles produced at the ablation site during laser ablation differs from the original sample and varies with their size. This can result in elemental fractionation (non-stochiometric sampling) in material delivered to the ICP-MS for quantitative analysis. Evidence of the element fractionation is preserved in chemically zoned ejecta deposited around the ablation pit....
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Preparation and properties of α,ω-bis(terpyridyl)oligothiophenes and related supramolecular polymers
Štenclová, Pavla ; Svoboda, Jan (advisor) ; Pfleger, Jiří (referee)
Presented diploma thesis describes synthesis of novel α,ω-bis(terpyridyl)bithiophenes and α,ω-bis(terpyridyl)terthiophenes with alkyl substituents on thiophene rings. The α,ω- -bis(terpyridyl)oligothiophenes were prepared using Suzuki-Miyaura coupling of 4'-(5- -bromo-3-alkylthien-2-yl)terpyridine with 2,5-thiophenediboronic acid and 2,2'-bi(1,3,2- -dioxaborolane), respectively. The succesfull transformation of 4'-(5-bromo-3-alkylthien-2- -yl)terpyridine to corresponding bis(terpyridyl)oligothiophenes was confirmed by NMR and HR-MS analyses and IR spectroscopy. UV-vis spectroscopy, excitation and emission photoluminescence (suplemented with determination of photoluminescence quantum yields) and cyclic voltammetry were used to study spectroscopic and redox properties of novel α,ω-bis(terpyridyl)oligothiophenes and previously prepared unsubstitued α,ω-bis(terpyridyl)bithiophene and α,ω-bis(terpyridyl)- terthiophene. Interaction of zinc ions with ligands soluble in tetrahydrofurane was studied using UV-vis spectroscopy and emission photoluminescence spectroscopy. Main-chain supramolecular polymers were sucessfully prepared from four soluble ligands and zinc ions. Properties of prepared polymers were studied using UV-vis spectroscopy, excitation and emission photoluminescence spectroscopy and IR...
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Terpyridine derivatives: preparation and complexation properties
Vitvarová, Tereza ; Svoboda, Jan (advisor) ; Sedláček, Jan (referee)
In this thesis we report synthesis of chosen terpyridine derivatives and their availability to make a complex with Zinc (II) ions and Iron (II) ions. These complexes were characterised and we studied their suitability to build supramolecular materials. Iron (II) complexes are more stable, but the Zinc (II) complexes are more suitable due to their good stability combined with great photophysical properties. We also report the polymerization of 4'-ethynyl-2, 2': 6', 2''-terpyridine as substance, which combines in the structure the possibility to make common covalent and non-covalent polymers. Last part of this thesis considers the synthesis of phosphole-based substances, which make as well as the terpyridine derivatives full conjugated system. Keywords: terpyridine, complexation, stability constant
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Potential contrast agents for MRI based on manganese(II) complexes
Drahoš, Bohuslav ; Lukeš, Ivan (advisor) ; Geraldes, Carlos F. G. C. (referee) ; Toth, Imre (referee)
The thesis is focused on the synthesis and characterization of novel Mn2+ complexes as alternative to Gd3+ chelates which are wide-spread contrast agents in Magnetic Resonance Imaging (MRI). In the perspective to find suitable chelators of Mn2+ , three groups of pentadentate ligands with different size of macrocylic cavity, different donor atoms and number of pendant arms containing various functional groups have been investigated. Coordination numbers of 6 or 7 were found in the crystal structure of the Mn2+ complexes enabling binding of one or two water molecules in the first coordination sphere. The direct water coordination causes a decrease in the complex stability and thus, the thermodynamic stability of investigated chelates is lower than that of polyaminocarboxylate complexes and their dissociation is very fast in comparison to [Mn(nota)] and [Mn(dota)]2- . The studied Mn2+ complexes do not undergo oxidation in air except for complexes with 12-membered ligands which are oxidized to Mn3+ species. The proton relaxivities of the bishydrated complexes are two times higher than those for monohydrated complexes and are comparable to those of commercial contrast agents based on Gd3+ complexes. Variable-temperature 17 O NMR data revealed that the water exchange varies from slow to intermediate or...
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Functional and structural study of thermally activated TRP ion channels: The role evolutionarily conserved motifs in the TRPA1 modulation
Kádková, Anna
Ankyrin receptor TRPA1 is an ion channel widely expressed on primary afferent sensory neurons, where it acts as a polymodal sensor of nociceptive stimuli. Apart from pungent chemicals (e. g. isothiocyanates, cinnamaldehyde and its derivatives, acrolein, menthol), it could be activated by cold temperatures, depolarizing voltages or intracellular calcium ions. TRPA1 channel is a homotetramer in which each subunit consists of cytoplasmic N and C termini and a transmembrane region. The transmembrane part is organized into six alpha- helices connected by intra- and extracellular loops. The N terminus comprises a tandem set of 16 to 17 ankyrin repeats (AR), while the C terminus has a substantially shorter, dominantly helical structure. In 2015, a partial cryo-EM structure of TRPA1 was resolved; however, the functional roles of the individual regions of the receptor have not yet been fully understood. This doctoral thesis is concerned to elucidate the role of highly conserved sequence and structural motifs within the cytoplasmic termini and the S4-S5 region of TRPA1 in voltage- and chemical sensitivity of the receptor. The probable binding site for calcium ions that are the most important physiological modulators of TRPA1 was described by using homology modeling, molecular-dynamics simulations,...
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Selection and development of educational materials for high school support webpage www.studiumchemie.cz
Zaspalová, Jana ; Šmejkal, Petr (advisor) ; Petrželová, Simona (referee)
This diploma thesis deals with selection, design and creation of new education materials for high school teacher supporting webpage www.studiumchemie.cz. The selection of the proper theme was done on the basis of research and evaluation of recent materials on the mentioned webpage and materials created at the Department of chemical education of Faculty of Science of Charles University in Prague. Preliminarily, the themes of synthetic macromolecular materials and new materials were selected. The convenience of the selected themes was confirmed by research and evaluation concerned to the preliminarily selected theme of recent high school textbooks and webpages. Consequently, educational materials in the form of PowerPoint presentations, websites, worksheets, tests, games and experiments focused on the themes of synthetic macromolecular substances and new materials were created. Materials were processed in accordance with the Framework Education Programme for Secondary General Education (Grammar Schools) as well as in accordance with the requirements of the Catalogue of graduation exam requirements from chemistry. The PowerPoint presentation and the webpage on synthetic macromolecular materials were roughly evaluated by group of teachers and the results of the evaluation are also part of the thesis....
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synthesis of conjugated polyacetylene based polymers
Duchoslavová, Zuzana ; Zedník, Jiří (advisor) ; Doubský, Jan (referee)
Mostly new acetylene based monomers were prepared. All monomers were prepared by the means of standard spectroscopic methods. All monomers were successfully polymerized using standard metathesis TaCl5 based catalyst. Prepared polymers were characterized by the means of GPC/GPC-MALLS chromatography and standard spectral methods. Fluorescence properties of all prepared compounds were also studied: quantum fluorescence yields were determined and excitation and emission fluorescence spectra were recorded. Polymerization on modern metathesis Grubbs-Hoveyda catalytic systems of all prepared monomers was also tested. These reactions were only partially successful and only low molecular weight oligomers in mediocre yields were obtained.
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Photopolymerization
Kučera, Vladimír ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The bachelor thesis deals with the photochemistry of macromolecular substances, especially with photopolymerization and photocrosslinking reactions. In the theoretical section there is at first a summary of the current knowledge from the area of the general photochemistry and principles of photochemical reactions which are also applied in photopolymerization. There are also both types of photopolymerization analysed – cationic and free-radical, photocrosslinking reactions and photopolymerization applications. In the experimental part, the testing of two fotopolymerization systems was performed. In both of them, styrene was used as a monomer. In one case benzoin was used as a photoinitiator, in the second one there was benzoin ethyl ether used. Furthermore, the photoinitiation ability of these two photoinitiators was compared at the base of conversion and molecular weight of products that were synthetized at different concentrations of photoinitiators and different time periods of irradiation of the mercury lamp.
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