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Matamorphosis of theoretical writing on African art in the 20th century
Bidlasová, Petra ; Winter, Tomáš (referee) ; Konečný, Lubomír (advisor)
According to Polish journalist Riszard Kapuscinski Africa is "a veritable ocean, a separate planet, a varied, immensely rich cosmos". The mere size and complexity of the African continent, consisting of many hundreds of tribes and dozens of states, mirrors in its culture and art and it renders impossible to reduce the modern history of African art to fit into one thesis. This fact made me concentrate on changes which occurred during the 20th century within the field of theoretical writing on African art [see Introduction]. Europeans have shown their interest in Africa for thousands years since the antiquities, starting as early as the 5th century B.C. with Herodotus, followed by Arabic merchants, who crossed Sahara and described with astonishment growing medieval empires of Central Africa: Ghana, Mali and Songhai. First period of greater interest is connected with 15th century European sailors, who were sent by their respective emperors to find gold, slaves and sale opportunities. This still leaves Europeans mainly on the African coast entering into the heart of Africa only after the colonial incursion in the late 19th century. An enormous amount of artworks was brought to Europe from Africa during the years and decades to come after the Berlin conference 1884-85, which almost deprived some tribes from...
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Characterization of separation systems for determination of enantiomers
Geryk, Radim
(EN) The dissertation thesis is focused on the research and characterization of retention and enantiorecognition mechanisms of chiral stationary phases based on derivatized polysaccharides. The separation systems with a variety of modern stationary phases (both achiral and chiral) were characterized in detail to provide a comprehensive view of the interactions participating in the separation process. The study of the retention/separation behavior significantly facilitates the development and the optimization of new enantioselective methods for a wide variety of compounds. The work deals with the comparison of enantioselective performance of polysaccharide-based chiral stationary phases. The objectives are to show the differences of separation behavior among these chiral stationary phases, as they differ by the nature of the polysaccharide backbone (amylose versus cellulose), by binding of chiral polymer to silica support (coated versus immobilized stationary phase) and by the phenyl moiety in the reversed and normal phase HPLC. In both separation modes amylose-based chiral stationary phases exhibited higher enantioselectivity, especially for acidic and bifunctional analytes. Chiral stationary phases based on derivatized cellulose showed higher enantiodiscrimination potential for basic analytes....
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Analytical evaluation of novel drug candidates from the group of iron chelators using HPLC I.
Schöngut, Michal ; Kovaříková, Petra (advisor) ; Kučera, Radim (referee)
Nowadays, high performance liquid chromatography (HPLC) belongs among the most modern and most frequently used analytical separation techniques. Biocompatible iron chelators are mainly used for the treatment of iron overload. Nevertheless, in the light of new information about physiological and patophysiological role of iron in organism, their potential use was widened into other diseases. Iron chelators were proved to have antioxidative, cardioprotective and cytostatic effects. Salicylaldehyde isonicotinoyl hydrazone is a biocompatible iron chelator, which also shows these activities. However, its short half life in plasma makes its use difficult. Nowadays, novel derivates of SIH were prepared to improve its stability in plasma. 2'-hydroxypropiophenone isonicotinoyl hydrazone (HPP-INH) is one of newly prepared SIH derivates. The aim of this study was to develop optimal chromatographic conditions for HPLC analysis of HPP-INH and to develop sample pretreatment method using precipitation for its analysis in plasma. The analysis was carried out on a Merck 250x4 mm column I.D. LiChrospher® 100, RP-18e (5 μm) protected with Purospher® 100, RP-18e (5 μm) guard column. The following mobile phase gradient condition was developed for HPP-INH purity evaluation: phosphate buffer (0,01 mol/l NaH2PO4 · 2 H20 water...
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Analysis of selected natural compounds by modern separation methods
Citová, Ivana ; Solich, Petr (advisor) ; Ševčík, Juraj (referee) ; Karlíček, Rolf (referee)
7 Summary The presented dissertation thesis deals with an extensive topic of natural compounds analysis by the means of modern separation techniques described from different points of view. Firstly, theoretical information about studied natural compounds (mainly antioxidants) has been summarized including characterization of the mechanism of free radicals formation and development of oxidative stress in human organism. Furthermore, the function of antioxidants and key roles of antioxidant therapy have also been discussed. Within the analyzed antioxidants, biological and physicochemical properties of phenolic acids, vitamins A and E and polyunsaturated fatty acids are described. Concurrently, known and published analytical procedures applied on each group of compounds are summarized. Besides antioxidants, content substances of yellow gentian (dried roots of Gentiana lutea) have been analyzed. Information about gentian pharmacological action, its practical utilization in therapy and ways of analytical determination represents the last chapter of theoretical part dealing with the studied compounds. The second point of view comprises characterization of individual separation techniques used in the thesis. Basic principles of gas chromatography (GC), solid phase microextraction connected to GC (SPME-GC), Ultra...
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Passive and mediopassive in contemporary Spanish
Prantnerová, Lenka ; Čermák, Petr (referee) ; Zavadil, Bohumil (advisor)
The present study deals with passive and mediopassive constructions in the modern Spanish language. The subjective perspective of Spanish is compared with other languages and the evolution of passive construction is explained. In the theoretical part there are two types of the passive defined and compared from the syntactical and functional points of view. The form and meaning of medium and mediopassive construction are also delimitated. Theoretical consclusions are verified in a special corpus of almost 2000 sentences taken from modern Spanish language. The analysis is dedicated to three main issues. The first part is dedicated to the frequency of appearance of passive constructions, the second part deals with morfological and syntactical analyses of the main parts of sentence and the third part studies the function of this type of constructions. There is also a separate analysis of the frequency of appearance of medium and mediopassive constructions and also of the principal features of their main parts of sentence.
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The Christian motif with abstraction tendency in sacral area after 1945
Bobůrková, Laura ; Hlaváčková, Jana Hana (referee) ; Lahoda, Vojtěch (advisor)
The thesis called "Christian motif with abstraction tendency in sacral area after 1945" deals with paintings related to this topic on the background of artistic profiles of the following artist: Mikuláš Medek, Ludvík Kolek, Jaroslav Šerých, Milivoj Husák and Petr Veselý. The sacral work is being put into context with Christian art which can be found in sacral environment. The introduction titled "Art and theology" is about the relationship between the modern Christian painting and theology. The artistictheological discussion cannot be separated from historical outlook or problems, which are closely connected with a question: Under what conditions and by the use of which artistic technique should we depict the likeness of God?
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Sample Preparation for Determination of Alpha-tocopherol in Erytrocyte Membrane by High Performance Liquid Chromatography
Denková, Barbora ; Šatínský, Dalibor (referee) ; Solich, Petr (advisor)
In this thesis, a new method for isolation of α-tocopherol from human erythrocyte membranes, using ultracentrifugation and solid phase extraction (SPE), for next HPLC analysis, was developed. Rightly SPE is nowadays one of the most effective and reliable modern methods permitting appropriate preparation of biological material sample before HPLC analysis. The developed SPE procedure is the following: 1) Washing of taken erythrocytes: 2,5 ml of blood is centrifugated 10 min at 1300×g, 4žC and the upper layer of plasma is separated. 0.01% saline BHT solution is added to the erythrocytes to a final volume of 2.5 ml and the centrifugation is repeated. The supernatant is removed and the whole operation is repeated three times. Washed erythrocytes are stored at a temperature of -86žC. 2) Proper α-tocopherol extraction from washed erythrocytes: 500 μl of 50 mmol/l D-mannitol solution and 500 μl of 5 mmol/l HEPES are introduced in the ultracentrifuge cuvette. Next, 100 μl of defrost washed erythrocytes are taken using a piston pipette. The pipette is carefully cleaned using cellulose and erythrocytes are introduced into the cuvette. 11 μl of 1 mol/l CaCl2 solution are then added and the sample is centrifugated for 3 min, at 90 000 rpm (288 000×g, rAV = 31,8 mm), at 4žC. Afterwards, 500 μl of supernatant is...
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Identification of Terpenoid Resins in Artworks by Gas Chromatography
Jelínek, Jan ; Beneš, Pavel (referee) ; Hrdličková Kučková, Štěpánka (advisor)
Terpenoic varnishes are used in artworks since 11th century. Their task is to protect the artworks against the adverse effects of the environment and frequently they complete the artistic page. Although synthetic varnishes are currently widely used, especially in the case of modern art, the use of natural materials is still widespread and not only in the restoration of historical paintings and polychromy. In order to prepare terpenoic varnishes, rich supply of natural resins is used (damare, mastic, copals, colophony etc.). These resins differ in their composition and therefore they have various physical properties such as fragility, solubility, and not least the various darkening of varnish. For these reasons, it is necessary to know their composition, in order to be safely removed during restoration and subsequently replaced by a varnish of the same material composition. Gas chromatography is the most widely used analytical method for determination of natural resins, using a number of derivatizing reagents. The task of this thesis was to find the best separation conditions for the identification of resins by gas chromatography combined with flame ionization detector (GC-FID).
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MoO3 supported on mesoporous molecular sieves - new catalysts for alkene metathesis and alkyne polymerization
Topka, Pavel ; Čejka, Jiří (advisor) ; Červený, Libor (referee) ; Hlubucek, Vratislav (referee)
Comprehensive Summary of PhD Thesis MoO3 supported on mesoporous molecular sieves - new catalysts for alkene metathesis and alkyne polymerization MoO3 nanesený na mesoporesních molekulových sítech - nové katalyzátory pro metathesi alkenů a polymerizaci alkinů (souhrn disertační práce) Ing. Pavel Topka J. Heyrovský Institute of Physical Chemistry of the ASCR, v. v. i. Department of Physical and Macromolecular Chemistry Faculty of Science, Charles University in Prague Prague, 2008 2 Introduction Modern homogeneous catalysts for metathesis reactions are based on stable carbene complexes especially of Ru, Mo, and W [1]. For large-scale industrial applications, heterogeneous catalysts remain the preferable choice because of low cost, high stability, easy catalyst regeneration and the possibility of easier separation of the catalyst from the reaction mixture. Typical examples are MoO3/SiO2, WO3/SiO2 and Re2O7/Al2O3, without or with cocatalyst (usually tetraalkyltin). Tungsten and molybdenum oxide catalysts require higher reaction temperatures, where side reactions decreasing metathesis selectivity can occur. Only rhenium oxide catalysts exhibit a high activity and selectivity at reaction temperatures below 100 řC. Supported molybdenum oxide catalysts have received much attention because they are widely used in...
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