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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.
71

Proteomická analýza vybraných onkohematologických onemocnění / Proteomic analysis of selected oncohematological diseases

Pimková, Kristýna January 2013 (has links)
Oxidative stress is an important factor in carcinogenesis of oncohematological diseases. However its role in the pathogenesis of myelodysplastic syndromes (MDS) remains unclear. In this study, we have determined the oxidative status and evaluated proteomic changes in plasma of MDS patients as a consequence of oxidative dysbalance (oxidative modifications, protein-protein interaction and complex forming). We measured the levels of total cysteine, homocysteine, cysteinyglycine, glutathione, nitrites and nitrates in the plasma from 61 MDS patients and 23 healthy donors using high performance liquid chromatography. Glutathione and nitrites levels reduced significantly while other aminothiols levels increased significantly in plasma of MDS patients. This association with oxidative stress did not correlate with iron overload. We also found enhanced levels of asymmetric dimethylarginine in serums of middle aged patients with MDS that correlate to posttranslational modifications of proteins arginyl residues. Furthermore, carbonylated proteins level was significantly elevated in MDS patients compared to healthy donors. Using mass spectrometry, 5 S-nitrosylated blood platelets proteins were identified in plasma and blood platelets of MDS patients and set of 16 plasma proteins with high probability of...
72

Transgenerační epigenetická dědičnost u savců / Transgenerational Epigenetic Inheritance in Mammals

Dostálová, Veronika January 2017 (has links)
Transgenerational epigenetic inheritance in mamals is a widely discussed topic in today's biology. Epigenetic modifications are molecules that play a crucial role in regulation of gene transcription. Epigenetic modifications regulate another epigenetic modification's establishment. The extrinsic and the intrinsic cellular or organismal environment is involved within the establishment of epigenetic state. The molecules involved in epigenetic processes are able to regulate gene transcription in reaction to the environment and therefore these molecules partly shape the phenotype. Most importantly, epigenetic processes are affected by cellular or organismal history. A question emerges: Are these molecules able to transfer information through germline to subsequent generations? Does transgenerational epigenetic inheritance in mammals exist? Experimental data show it is so. What consequences this can mean in our understanding of evolution? Powered by TCPDF (www.tcpdf.org)
73

Biotechnologie jako politický systém / Biotechnology as political problem

Sobotková, Lenka January 2008 (has links)
Thesis is concentrated on two biotechnologies: biofuels and genetically modified crops. Defines technical and economical characteristics, lists international agreements and czech and european legislation regarding both biotechnologies. Introduces opinions and analyses positions of selected political subjects as UNO, WTO, OECD, EU, catholic church and main czech political parties.
74

Biografické snímky jako konstrukce reality / Biographies as a construction of reality

Martinů, Jakub January 2021 (has links)
The diploma thesis is focused on the transmediality and adaptation phenomena and on the process of adaptation translation into the performative medium, a movie. The phenomena are grounded in the academical background, and their origin and historical development of their studies are contained in the theoretical part of the thesis. Furthermore, the different approaches to evaluation of the final product of the adaptation process are analyzed and it is explained that the evaluation of the adaptation is not bound by the fidelity criteria, but rather the overall transformation of the original message into the new media, in this case a movie. Due to these findings, the method of qualitative comparative analysis was used for the analytical part of the thesis. The qualitative research was focused mainly on the adaptation shifts as defined by Katerina Perdikaki, modulation, modification, mutation. Four biographical books of well- known personalities and their subsequent movie adaptations were analyzed. From these stories, four key moments were chosen to be used for the qualitative comparative analysis in order to research the adaptation shifts in the individual stories and their impact on the process of the creation of the adaptation and the final performative piece. The sample of the books was carefully...
75

Modifikace povrchu materiálu vytvořeného technikou SLM / The use of surface modification for enhancing mechanical properties of SLM bulk materials

Barinka, Michal January 2021 (has links)
This diploma thesis deals with the surface modification of 3D printed metallic materials. The research part presents the most used methods of additive manufacturing and their process parameters influencing the quality of printed components. Defects arising during these processes and the techniques used to eliminate them are also described. In the experimental part of the work, the optimization of electrochemical polishing parameters was performed. The aim was to modify the rough surface of the components and thus prevent the formation of defects on the surface. The mechanical properties were investigated by means of three-point bending under static and dynamic loading. Fractographic analysis was performed on the quarry surfaces.
76

Modifikace konstrukce samonakládacího transportéru / Modification of frame construction of the self-loading semitrailer

Dvořák, Lukáš January 2021 (has links)
This master’s thesis deals with research similar self-loading packege transporters. The stress analysis and modification of the selected transporter are followed. The master thesis contains stress analysis of the original version, design of a modified version and stress analysis of the modified version. Then the original and modified versions are compared.
77

Chemické modifikace polypropylénových povrchů / Chemical modifications of polypropylene surfaces

Pospíšek, Marek January 2014 (has links)
Diploma thesis is focused on modification and characterization of polypropylene (PP) products surfaces by the chemical way. In theoretical part of thesis are summarized the current knowledge of this topic including characterization methods. Polypropylene surfaces were modified by acrylic monomers (acrylic acid, acrylic acid with 20 mol% content of sodium acrylate and acryl amide). Modified surfaces were characterized by infrared spectroscopy with ATR technique. The comparative parameter was carbonyl index determined from absorption peaks of functional methyl groups (2950 cm-1 ) and functional carbonyl groups (1700-1750 cm-1) of FTIR-ATR spectra. Determination of effect of initiator concentration on the modification process was done for acetophenone and benzophenone. There were determined the time dependence of carbonyl index for time from 0 to 600 s of mentioned monomers. In the same condition were modified test specimens designed for preparation of adhesive joints. Joints were bonded by cyanoacrylate adhesive that provide reaction with surface of polyacrylic acid. There were founded conditions of modification that provided strength of adhesive joints higher than strength of original PP. There were identified changes of surface roughness by using of confocal microscopy.
78

Chemické modifikace hydrogelů z přírodního polysacharidu / Chemical modifications of hydrogels from natural polysaccharide

Poštulková, Hana January 2014 (has links)
V teoretické části práce by shrnuty chemické a fyzikální vlastnosti, chemická struktura a využití přírodního polysacharidu gum karaya. Hlavním cíle diplomové práce byla alkalická modifikace původní nerozpustné gum karayi na rozpustný produkt, který může být v budoucnu využit pro další aplikace například v medicíně. Nerozpustnost gum karayi je způsobena přítomností acetylových skupin a vícemocných iontů ve struktuře polysacharidu. Byly zkoumány optimální podmínky pro modifikační proces. Pro modifikaci byl použit hydroxid sodný, draselný nebo amonný a čas modifikace od 1 minuty po 24 hodin pro roztok originální gum karayi s koncentrací od 0,1 do 3 %. Pro určení chemického složení originálního a modifikovaných vzorků byla využita FTIR. Bylo prokázáno, že vzorky A2, B1 - 7, C1 - 8 a E1 - 2 byly zcela deacetylovány, protože pás pro acetylovou skupinu nebyl v FTIR spektrech pozorován. Odstranění acetylových skupin alkalickou modifikací bylo taktéž potvrzeno 13C CP MAS NMR. Pomocí XRD byl prokázán amorfní charakter originálního vzorku. Množství vlhkosti a teplotní stabilita vzorků byly zkoumána pomocí TGA. Bylo zjištěno, že termální stability originální gum karayi je vyšší než u modifikovaných vzorků. Termální stabilita modifikovaných vzorků byla ovlivněna reakčními parametry. Entalpické změny vzorků byly studovány pomocí DSC, nicméně nebyly pozorovány žádné významné rozdíly mezi modifikovanými vzorky a originální gum karayou. Prvkové složení bylo určeno pomocí ICP-OES a byla potvrzena přítomnost vápníku, draslíku a hořčíku ve struktuře polysacharidu. Molekulová hmotnost modifikovaných vzorků byla měřena pomocí GPC a byla stanovena na 8 milionů g·mol-1. Reologické měření roztoků gum karayi bylo provedeno pro určení lineární viskoelastické oblasti. Dále byl sledován efekt NaCl na viskozitu originálního vzorku. Viskozita klesala s vyšším množstvím NaCl. Pokles viskozity originálního vzorku je způsoben výměnou vápenatých iontů za sodné, což vede k uvolnění fyzikálně vázané struktury a tím k vyšší rozpustnosti vzorku ve vodě.
79

Nové elektrodové struktury pro alkalické akumulátory / New electrode structures for alkaline accumulators

Fusek, Petr January 2011 (has links)
Master´s thesis is focused on development of electrodes used in alcaline accumulators, by using new kinds of materials and compounds. Basic possitive eletrode was made of nickel, on this electrode were applied new layers of Ni(OH)2 by using the method called electrodeposition. For electrodeposition was used solution with Ni(NO3)2 in diverse concentrations. Later on, this material was enriched with aluminium admixtures to increase stability of alfa modification in Ni(OH)2. These concentrations were measured and analysed in diagrams. For measurement was used device Biologic. The diagrams were commented with recommendations for production use in accumulators.
80

Vliv cílené modifikace topografie na únavové poškozování třecích povrchů / Effect of surface texturing on rolling contact fatigue of rubbing surfaces

Popelka, Jakub January 2008 (has links)
Diploma thesis describes influence of directed modificated topography of frictional surfaces on fatigue wear non-conformal incurvate solids. It was created 3D parametric model of experimental test rig in modelling environment Autodesk Inventor. With the help of model was designed and carried reconstruction of experimental test rig so to possible obtain repeatable results under the sliding conditions of frictional surfaces. It enabled show influence of surface iregularities (dents) frictional surfaces on contact fatigue service life in conditions mixed lubrication regime and different values of slide to roll ratio.

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