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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Studium molekulární organizace systému cytochromu P450 pomocí fotoaktivovatelných proteinů / Study of molecular organization of cytochrome P450 system using photoactivatable proteins

Dědič, Jan January 2015 (has links)
The cytochrome P450 system plays an important role in metabolism of endogenous compounds and xenobiotics. This system consists of cytochrome P450, NADPH:cytochrome P450 oxidoreductase (CPR), cytochrome b5 and NADH:cytochrome b5 reductase (CYB5R3). Explanation of protein-protein interactions among these reaction partners is essential for understanding the function of the entire system. Covalent cross-linking is a favorable method for studying these interactions. In this work a photo-activatable analogue of amino acid L-methionine (L-photo-methionine) was used as a cross-linking agent. This work is focused on the organic synthesis of L-photo-methionine, expression and isolation of CPR and CYB5R3 as photoactivable proteins containing incorporated L-photo-methionine. Auxotrophic strain of E.coli B834 (DE3) and minimal media were used for the expression. CYB5R3 with incorporated L-photo-methionine was successfully expressed and isolated. The extent of L-photo-methionine incorporation was verified by mass spectrometry. Furthermore, the photo-initiated cross-linking of CYB5R3 with cytochrome b5 was tested. Key words: photolabile amino acid, protein expression, synthesis
42

Komplexy aminoalkylfosfinoxidů / Complexes of aminoalkylphosphineoxides

Mészáros, Bence January 2017 (has links)
Title: Comlpexes of aminoalkylphosphineoxides Author: Bence Mészáros Department: Department of Inorganic Chemistry, Faculty of Science UK Supervisor: doc. RNDr. Vojt ch Kubí ek, Ph.D. Supervisor's e-mail address: kubicek@natur.cuni.cz Three selected aminoalkylphosphine oxides were synthesized: Aminomethyl(diphenyl)phosphine oxide, N-piperidylmethyl(diphenyl)phosphine oxide, N,N-diethylaminomethylbis(hydroxomethyl)phosphine oxide. All prepared substances were characterized by NMR spectroscopy and mass spectrometry. The aminomethyl(diphenyl)phosphine oxide and N-piperidylmethyl(diphenyl)phosphine oxide were obtained in the solid state as single crystals and their structure was determined by X-ray analysis. Acid-base and complexing properties of the studied compounds were studied by potentiometric titration and NMR titration. Protonation constants of all three compounds were obtained, stability constants were not determined because of the low solubility of the complexes in water or low stability of the complexes. The structure of the aminomethyl(diphenyl)phosphine oxide complex with Cu2+ was determined by X-ray analysis. Keywords: complexes, organophosphorus synthesis, phosphine oxides, acid-base and complexation properties
43

Reaktivita a vlastnosti analog trifosfátu / Reactivity and properties of triphosphate analogues

Šrein, Jakub January 2017 (has links)
Reactions leading to cyclization on methylene bridges in PCPCP structure motif were investigated. It was found, that these reactions result in number of various isomers. Some of these isomers were characterized by NMR and MS spectroscopy, but none was isolated. Further, acid-base properties of bis(methylenephosphonato)phosphineic acid were investigated. Formation of complexes was studied with lithium(I), calcium(II), copper(II) and zinc(II) cations. Furthermore, interaction between bis(methylenephosphonato)phosphinic acid and ethylenediamine was investigated by NMR and potentiometric titration. The results show formation of H-bond-based adducts.
44

Stereoselektivní adiční reakce na ketiminy / Stereoslective addition reaction to ketimines

Franc, Michael January 2017 (has links)
This diploma thesis deals with the stereoselective addition reaction of benzothiophenone derivatives to ketimines derived from isatin using bifunctional organocatalysis. The stereoselective addition reaction was optimized to provide the appropriate reaction conditions which were subsequently used to study the scope of the reaction. Keywords Organocatalysis, stereoselective synthesis, bifunctional organocatalysts, ketimines, sulphur heterocykles.
45

Analýza počítačové simulace zvuku a jejích limitů / Analysis of computer simulation of sound and its limits

Hlavsa, Ondřej January 2009 (has links)
This thesis is focused on the question whether it is possible to fully simulate the sound of real musical instruments on the personal computer. The opening chapters deal with basic characteristics of sound information, its perceiving and also its digital form. Futher there is an elaborate analysis of computer simulation in comparison with legitimate records. The output of this part are worded assumptions. The next parts offer a detailed look at programming approaches and methods of computer sound creation. The research leads to a hearing test in which author tries to confirm the hypotheses as well as to answer the primary question.
46

Opatření pro zvýšení efektivity výzkumu v oboru chemické syntézy (Measures towards increasing the effectiveness of research in the field of chemical synthesis) / Measures towards Increasing the Effectiveness of Research in the Field of Chemical Synthesis

Václavík, Jiří January 2015 (has links)
Research in the field of chemical synthesis is a very diverse and complex activity. Individual workplaces differ in many aspects and this essentially impacts the productivity. The aim of this Master's Thesis is to identify, name and analyse those aspects, and to suggest measures to be taken in order to help increase the performance, all that within defined assumptions. The first half of the Theoretical Part is devoted to academic studies on this topic, which are mainly focused on the HR part. Selected methods of lean manufacturing commonly used in industry are also described. The Experimental Part comprises an analysis of research facilities in which the author worked as a chemist, and a set of proposed measures that lead to an increased productivity. The Thesis is concluded by a demarcation of a series of factors that influence the performance of R&D workers, groups and institutions, and a vision of an ideal laboratory is presented.
47

Redukce elektronově deficitních dendralenů hydridovými činidly / Reduction of electron-deficient dendralenes by hydride reagents

Kratochvíl, Ondřej January 2021 (has links)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Candidate: Ondřej Kratochvíl Supervisor: prof. RNDr. Milan Pour, Ph.D. Supervisor - specialist: Mgr. Rastislav Antal Title of Thesis: Reduction of electron-deficient dendralenes by hydride reagents This diploma thesis is focused on the preparation of electron-deficient [3]dendralenes containing electron withdrawing groups such as carbonyl and ester functionalities. The synthesis is based on a palladium-catalyzed Migita-Stille coupling between stannylated diene and iodinated alkene (cycloalkene). Subsequent reaction of these substituted [3]dendralenes with hydride anion leads to a 1,2- or 1,4-addition to the α, β-unsaturated carbonyl group, resulting in the formation of an enolate or alcoholate, which are further transformed to various products depending on the type of the [3]dendralene.
48

Vysoce porézní keramické oxidové materiály pro environmentální katalýzu / Highly porous ceramic oxide materials for environmental catalysis

Husťák, Miroslav January 2021 (has links)
As far as the replacement of fossil fuels with more environmentally friendly options is concerned, hydrogen is considered as the most promising source of energy. Currently, hydrogen is mainly produced through the method of methane reforming. This method requires the utilisation of catalysts made of precious metals. This master's degree thesis therefore investigates perovskite materials SmCoO3, Sm0,8Ca0,2CoO2,9, SmCo0,8Al0,2O3 and Sm0,8Ca0,2Co0,8Al0,2O2,9, which could be utilised as catalysts in the production of hydrogen by methane reforming. Methane reformation occurs on the surface of a catalyst. Therefore, it is desirable to ensure that the specific surface area of a catalyst material is as large as possible. For that reason, the aforementioned perovskite materials were prepared by two sol-gel methods, which are expected to create perovskites with large specific surface areas. It was investigated in the course of the work how the method of synthesis affects the structure and catalytic properties of individual materials. The SmCo0,8Al0,2O3 material prepared by a sol-gel synthesis with propylene oxide as a gelation agent demonstrated the best results - the measurement of catalytic activity showed that the methane conversion had achieved the value of 99%.
49

Syntéza derivátů haemanthaminu a jejich biologická aktivita / Synthesis of haemanthaminy derivatives and their biological activity

Bodoríková, Viera January 2019 (has links)
4 ABSTRACT Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Viera Bodoríková Supervisor: doc. Ing. Lucie Cahlíková, Ph.D. Title of Diploma thesis: Synthesis of haemanthamine derivatives and their biological activity Haemanthamine, an isoquinoline Amarillidaceae alkaloid, exhibits a wide and important range of biological activities, including antitumor, antiviral, antioxidant, antimalarial and anticonvulsant. Biological activity of haemanthamine relatives closely with its structure. By modifying the different parts of the molecule, we can identify some structure-activity relationships. With this aim, the thirteen semisynthetic analogues of alkaloid haemathamine were prepared and purified using analytic and preparative TLC methods. The obtained substances were then subjected to structural analysis, specifically, there were used MS, HRMS, 1D and 2D NMR spectroscopic techniques. Prepared compounds were tested on its possibility to inhibit human erythrocytic acetylcholinesterase (HuAChE) and human serum butyrylcholinesterase (HuBuChE). The most promising biological activities have been shown by aromatic esters labelled as LC- 70 (IC50 HuAChE = 0,12 ± 0,01 µM) and LC-73 (IC50 HuAChE =0,17 ± 0,01 µM). The cytotoxic activity of prepared compounds has been...
50

Syntéza a slinování keramiky na bázi ZrO2 pro biomedicínské aplikace / Synthesis and sintering of zirconia based ceramics for biomedical applications

Jahodová, Daniela January 2017 (has links)
The present thesis focuses on the preparation of tetragonal zirconia doped with yttria oxide, ceric dioxide, and magnesium oxide. In its theoretical part the thesis covers the characteristics of doped ceramics, the possible methods of powders preparation and of their further processing. The experimental part describes the precipitation synthesis of zirconia in base environment and further processing for ceramics. Also studied were the influences of dopant and of the processing technique used on the phase composition and microstructure of the resulting ceramics. To describe the powder structure, the thermal, dilatometric, surface area, and x-ray analyses were performed; as well as both the scanning and transmission electron microscopy employed. Dry processed ceramics showed the average grain size of 87–94 nm and the relative density in the range of 84,0–99,3 %. In comparison, the ceramics produced of hydrothermally synthesised powders proved the average grain size of 75–85 nm and the relative density between 92,7-99,9 %. As the next step, samples were subjected to low-temperature degradation for the time of 5 and 15 hours. Samples consisting of pure tetragonal ZrO2 were resistant to 5 and 15 hours of low-temperature degradation at 180 °C.

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