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The synthesis of poly(butadiene)diol-based polyurethanes with LC properties
Poláková, Lenka ; Sedláková, Zdeňka (advisor) ; Šňupárek, Jaromír (referee) ; Hamplová, Věra (referee)
8 Summary The PhD thesis is focused on the synthesis and characterization of low-molecular mesogenic thiols and poly(butadiene)diols and polyurethanes with LC side chains. Within the frame of this work, following tasks have been solved: Two groups of low-molecular compounds containing a biphenyl or an azobenzene as a rigid mesogenic part have been synthesized: N YNOSHXO SH Y = -H -OCH3 -O(CH2)3CH3 -O(CH2)7CH3 X = -H -CN Composition and structure of the prepared units were confirmed by elemental analysis and 1 H NMR spectroscopy. Thermal behavior, with the respect to the temperature-dependent mesophase formation, was studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray scattering techniques (SAXS, WAXS). It was found that the presence and the type of the substituent on the mesogenic core play a crucial role in the ordering of the thiol molecules into a LC phase. The thiols synthesized were grafted onto double bonds of the commercially available telechelic poly(butadiene)diol Krasol LBH 3 000 (declared Mn ~ 2 600 Da, Mw/Mn = 1.10). The addition reactions proceeded in the presence of radical initiator (AIBN). Molar ratio of thiol/double bonds varied within the range of 0.15 (resp. 0.2) to 1.0 for each type of the thiol. The structure of the resulted comb-like...
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Media representation of Jan Masaryk in Selected Newspapers in Autumn 1938 and Spring 1948
Poláková, Lenka ; Cebe, Jan (advisor) ; NÁHRADNÍ, OPONENT (referee)
Jan Masaryk, the son of Tomáš Garrigue Masaryk was the Czech ambassador in London since 1925 to 1938. He was the one of a few Czechoslovaks in autumn 1938 who was in touch with British prime ministr Neville Chamberlain, Foreign Secretary lord Halifax. He was able to see the situation of our small state was lost after the signing the Munich agrément which transfered the Sudetenland to Germany. So he decided to leave his ambassador office in London. I'm trying to subscribe the media representation of Jan Masaryk in my work in selected newspaper which were representing the different political tendencies. The second part of the work attends to the year 1948. Jan Masaryk had been at this time Czechoslovakian Foreign Secretary for free years. The events in Czechoslovakia of 1947 and 1949 gradually led to the Communist coup in February 1948. The prime minister Klement Gottwald had to form a new government because of resignations of the democratical ministers (Masaryk not encluded). I also made an analyse of the press at that time, when Masaryk decided to say yes to the communist totality.
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Preparation and characterization of 2-hydroxyethyl methacrylate hydrogels for testing of anticancer drugs carriers
Mudrová, Barbora ; Bosáková, Zuzana (advisor) ; Poláková, Lenka (referee)
In present bachelor thesis, hydrogels based on 2-hydroxyethyl methacrylate and methacrylic acid (pHEMA-MA) were prepared and characterized. Hydrogels could serve as a testing medium in the development of nanofiber polylactide (PLA) systems for local application of paclitaxel (PTX). This medium has been studied in an effort to create conditions that better correspond to the actual environment of a human body than commonly used liquid media. Local application of cytostatics in the treatment of solid tumors has a number of advantages. PTX represents a hydrophobic anticancer drug with serious side effects. Local distribution of presented drug using nanofiber carriers could greatly reduce the adverse side effects while increasing its concentration and duration of effect in target tumor tissues. The effect of the addition of polyethylene glycol (PEG) with a molecular weight of 20 kDa and β-cyclodextrin (CD) to the nanofiber structure was further investigated to optimize the release of the incorporated drug. The release kinetics of PTX from PLA nanofibers into pHEMA-MA hydrogels were studied using analytical method HPLC with UV detection. The experiment was also performed using an aqueous PBS solution as the release medium for comparison of the PTX release profiles. The sorption of PTX into pHEMA and...
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Inhibition study of human 17β-HSD3
Poláková, Lenka ; Štambergová, Hana (advisor) ; Zemanová, Lucie (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Lenka Poláková Supervisor: PharmDr. Hana Štambergová, Ph.D. Title of diploma thesis: Inhibition study of human 17β-HSD3 Enzyme 17β-hydroxysteroid dehydrogenase 3 belonging to the short-chain dehydrogenase/reductase superfamily is involved mainly in reduction of 4-androstane-3,17- dione to testosterone. Any changes in amount of testosterone can result in illness, such as the male pseudhermaphroditism or the prostate cancer. For this reason studies of inhibion effects of various substances have been doing as they could be used in the therapy such as illnesses. Identification of the pharmacologically interesting substances was performed in vitro through the model system. Cell line Sf9 was used to prepare a recombinant form of the target enzyme. Reduction activity of this enzyme was verified towards androstene-4,17-dione. Then screening of potential inhibitors, natural substances: flavonoids and alkaloids, was performed. IC50 value was defined at substances with 100% inhibition effect (2-hydroxyflavanone, biochanine A, fumariline).
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The synthesis of poly(butadiene)diol-based polyurethanes with LC properties
Poláková, Lenka ; Sedláková, Zdeňka (advisor) ; Šňupárek, Jaromír (referee) ; Hamplová, Věra (referee)
8 Summary The PhD thesis is focused on the synthesis and characterization of low-molecular mesogenic thiols and poly(butadiene)diols and polyurethanes with LC side chains. Within the frame of this work, following tasks have been solved: Two groups of low-molecular compounds containing a biphenyl or an azobenzene as a rigid mesogenic part have been synthesized: N YNOSHXO SH Y = -H -OCH3 -O(CH2)3CH3 -O(CH2)7CH3 X = -H -CN Composition and structure of the prepared units were confirmed by elemental analysis and 1 H NMR spectroscopy. Thermal behavior, with the respect to the temperature-dependent mesophase formation, was studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray scattering techniques (SAXS, WAXS). It was found that the presence and the type of the substituent on the mesogenic core play a crucial role in the ordering of the thiol molecules into a LC phase. The thiols synthesized were grafted onto double bonds of the commercially available telechelic poly(butadiene)diol Krasol LBH 3 000 (declared Mn ~ 2 600 Da, Mw/Mn = 1.10). The addition reactions proceeded in the presence of radical initiator (AIBN). Molar ratio of thiol/double bonds varied within the range of 0.15 (resp. 0.2) to 1.0 for each type of the thiol. The structure of the resulted comb-like...
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Vliv změny prostředí na dlouhověkost a produkci mléka krav českého strakatého skotu ve vybraném chovu
Poláková, Lenka
The aim of this thesis was to evaluate the effect of environmental changes on longevity and milk production of cows Czech Fleckvieh cattle in selected breeding. The work focused on the comparison parameters milk production, longevity reasons decommissioning cows and lactation on which the cows were excluded. Within one company were monitored two groups of cows. The first group of cows was monitored in the original stabling. The second group consisted of pregnant heifers whose milk production have been monitored in subsequent years. They were removed to new stabling among cows of Holstein cattle. Each of the groups had different environmental conditions, treatment and different feed ration. Milk production and longevity of cows were evaluated in six years. In the framework of the obtained results it can be concluded that the change in the environment, treatment and feed ration were the main reason leading to the increase in the milk production of cows in the new location. Cows in the new stabling were mostly eliminated because of the reproductive disorder, milk production and other reasons (mortality, high age, diarrhea, poorly developed teats, bad condition).
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