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Effect of freeze-drying conditions on the hydrophobic interaction between native hyaluronan and fluorescent probe
Říha, Karel ; Venerová, Tereza (referee) ; Enev, Vojtěch (advisor)
The biopolymer native hyaluronan possesses the amphiphilic character of its molecule. Which means that it contains both a hydrophilic and a hydrophobic part. This character of the molecule favors interactions between hydrophobic ligands and hydrophobic parts of the chain, making hyaluronan one of the compounds potentially suitable as drug carrier systems. The aim of this bachelor thesis was to prepare a carrier system based on hyaluronan and model hydrophobic compounds (fluorescent probes). The fluorescent probe we used was pyrene. Furthermore, the work was focused on the study of lyophilization conditions, which would lead to the actual influence of hydrophobic interactions between the substances we used. The main techniques that served us to verify the effectiveness of lyophilization (in the sense of supporting the creation of a hydrophobic effect between individual hyaluronan chains) were: thermogravimetric analysis, fluorescence spectrometry, and last but not least, infrared spectroscopy with Fourier transformation.
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Bronze swords in the Early Iron Age in Bohemia
Říha, Karel ; Frank Danielisová, Alžběta (advisor) ; Golec Mírová, Zuzana (referee)
The work aims to discuss the origin and significance of bronze swords from the Early Iron Age. In the Czech lands, these artifacts are associated exclusively with graves. Based on the study of foreign literature, a theoretical excursion is presented in terms of genesis, context and findings and concept of transition horizon Ha C1a. The following is a study based on the application of archaeometric methods on a borrowed file. Based on the results of radiographic, traceological, metallographic and isotope analysis, including chemical composition, it is possible to define practically their structural quality, potential use and origin of the material. The result is a pilot study of Ha C bronze swords, which - ideally - will be analytically extended to the context of Central Europe, not only in the West Hallstatt area, but also in the Lusatian urnfields. Keywords bronze swords - Hallstatt period - genesis - classification - radiography - use-wear analysis - metallography - chemical composition - isotopes
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Study of the DNA recombination mechanisms in plants
Kozák, Jaroslav ; Angelis, Karel (advisor) ; Široký, Jiří (referee) ; Říha, Karel (referee)
DNA double-strand break (DSB) is a dangerous type of DNA damage, but it also serves in controlled increase of genetic variability. The two major DSB repair pathways are homologous recombination (HR) using homologous sequences and non- homologous end joining (C-NHEJ). Two model plants Arabidopsis thaliana (Arabidopsis) and the moss Physcomitrella patens (Physcomitrella) differ in DSB repair strategies. Arabidopsis uses C-NHEJ, however Physcomitrella prefers HR. These plant models are compared on the basis of measurement of DSB and single strand breaks (SSB) repair by comet assay. The half-life of the first rapid phase of the DSB repair is about 5 minutes in both plant species. Although the C-NHEJ is considered as the main DSB repair pathway in Arabidopsis, rapid repair is independent of AtLIG4 and AtKu80, suggesting the existence of the effective backup non-homologous repair pathways (A-NHEJ). In Physcomitrella, the rapid DBS repair dominates in mitotically active cells and is also independent of PpLIG4. Conversely, PpLIG4 is surprisingly involved in the repair of the DNA alkylation damage. An essential DNA ligase of the rapid DSB repair pathway in Arabidopsis is the replication ligase AtLIG1, which is also responsible for the alkylation DNA damage repair, and thus represents a functional homolog of...
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Analysis of aplication potential of the Lean manufacturing principles in the selected industrial company
ŘÍHA, Karel
The basis of lean manufacturing is to minimize the inventories to reveal the disfunctions of the production system and to optimize process to avoid every kind of wastes. Lean systems are characteristic with smooth pull production system with one piece flow and just in time supplements of inventories. The layout of the line is transformed to the U work cell and the material is ordered by using kanban tickets. To receive the potential of implementation of the lean manufacturing principles we can use indicators IE - industrial efficiency and PLT - pruduction lead time.
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