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New Methods of Cross-linking of Humic Substances
Lepíková, Jana ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This bachelor thesis was focused on the study of crosslinking of humic substances. The main aim of this work was to find and optimize utilization of new crosslinking agents for humic acids. Commercial product – lignohumate – was also used in the work as comparative sample. Two groups of crosslinking agents were studied in this work – multivalent metals (CaCl2, MgCl2) and citric acid. In all cases the studied hydrogels were cross-linked by means of chemical valences. All prepared hydrogels were characterized using the determination of their inner pH, density and concent of dry matter. The process of aging of hydrogels – syneresis – was also studied. The main experimental method applied for hydrogels characterization was rheology. Prepared hydrogels represent interesting materials for following studies and also for possible future practical applications.
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Modification of polyvinylalcohol of lower saponification degree for preparation of MDF composites
Kotrla, Jan ; Švec, Jiří (referee) ; Šoukal, František (advisor)
The subject of the bachelor thesis is modification of polyvinylalcohol of lower saponification degree for preparation of MDF composites. MDF composites are characterized by their extreme mechanical properties. However, their low resistance to moisture is a significant disadvantage. Increased moisture resistance could be achieved by grafting suitable functional groups on the polymeric chain and the subsequent cross-linking. The study is focused on optimization of the number of functional groups and the cross-linking conditions. The number of grafted functional groups was determined by UV – VIS, XPS analysis and IR spectrophotometry. The solubility of the crosslinked samples was measured by rheological measurements.
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Technology of monofilamentous fibers based on oxidized hyaluronic acid
Běťák, Jiří ; Mráček, Aleš (referee) ; Burgert, Ladislav (referee) ; Klučáková, Martina (advisor)
Předkládaná dizertační práce se zabývá vývojem technologie výroby nového typu biodegradabilních vláken na bázi oxidované kyseliny hyaluronové. V rámci práce je postupně představován vývoj jednotlivých jednotkových operací výroby, jejichž správné porozumění a schopnost jejich řízení jsou klíčové pro žádaný chod celé vícestupňové technologie. V rámci práce je představen nezbytný vývoj technologického zařízení, průběžně konstruovaného pro účely laboratorního testování a následně až po samotnou linku pro finální výrobu vláken, která byla realizována v roce 2015. V rámci dizertační práce jsou dále navrhovány možnosti dodatečné chemické úpravy vláken s ohledem na zvyšování jejich stability ve vlhkém prostředí. S ohledem na cílené aplikace vláken pro vnitřní chirurgické implantace, jsou v práci vlákna též hodnocena z hlediska jejich materiálové biokomaptibility (toxicity).
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Reactions of HDPE in the melt initiated by peroxides
Hampapa, Břetislav ; Kučera, František (referee) ; Petrůj, Jaroslav (advisor)
The thesis deals with HDPE modification by crosslinking. In the theoretical part, data available in the literature were reviewed. Modifications of the selected HDPE copolymer grade were carried out in a kneading device Brabender using 25 ml chamber size. After having optimized process conditions, there were performed a series of experiments in dependence on concentration of the initiator. Reological properties of polymer samples were investigated by melt flow indexes measured under different conditions. Changes in crystallinity and melting temperatures were evaluated from DSC heat flow measurements. The samples meeting characteristics supposed were selected for measuring complex viscosity on the Rheometer AR-G2 TA and for testing some mechanical properties on the device Zwick.
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Novel hydrogels based on polysaccharides for soft tissue regeneration: preparation and characterization
Nedomová, Eva ; Abdellatif, Abdelmohsan (referee) ; Vojtová, Lucy (advisor)
Předložená diplomová práce se zabývá přípravou, síťováním a fyzikálně-chemickou charakterizací hydrogelů na bázi polysacharidů. Cílem práce bylo vyvinout elastické filmy, které by mohly být použity pro vlhké hojení ran. Teoretická část shrnuje současné způsoby regenerace měkkých tkání a jejích náhradách (ať už se jedná o přírodní nebo syntetické materiály). Zároveň jsou zdůrazněny základní informace o přírodních polysacharidech (chemická struktura, rozpustnost, tepelná a pH stabilita atd.), jejich modifikace a chemické síťování. Experimentální část je zaměřena na modifikaci přírodní gumy Karaya tak, aby transparentní hydrogely měly nastavitelnou hydrolytickou stabilitu. Vzorky byly analyzovány pomocí FTIR, TGA následované vyhodnocením bobtnání a hydrolytické degradace. Z výsledků vyplynulo, že chemická modifikace zvýšila stabilizaci elastického filmu z přírodního polysacharidu ve vodě až na 25 dní. Díky řízené degradaci a vysoké absorpci vody (85 - 96%) jsou tyto nové hydrogely využitelné především pro vlhké hojení ran (např. popálenin).
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case management in municipalities
HORNÁTOVÁ, Zuzana
The bachelor thesis deals with case management, which is a process of coordinated cooperation between the client and the case manager. The aim of the thesis is to find out whether the municipalities with extended competence in South Bohemia have information about the benefits of case management in municipalities. The theoretical part is based on the study of literature related to the topic and is focused on the definition of terms such as case management, case management models, case manager, social work in municipalities. Furthermore, topics such as networking, case conferencing, confidentiality, community planning and health and social care are explained. The practical part of the bachelor thesis is devoted to the evaluation of the research questions through a qualitative research strategy. The necessary data was collected through interviews with social workers from different municipalities in South Bohemia based on the recommendations of the previous communication partner. I categorised and subsequently analysed the collected material using the open coding method. On the basis of these steps it was possible to evaluate the aim of the bachelor thesis and to draw a conclusion. From the result of the research, it can be concluded that workers in municipalities in South Bohemia have only theoretical information about case management, but are aware of the importance of coordinated cooperation, which they do to a limited extent. With one exception, where the municipality uses case management in social work after prior training and increasing the number of staff. The results obtained could be used in practice by social workers in municipalities that are considering introducing case management into their social strategies.
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Development of material for agar-based ultrasound brain phantom
Řehořková, Petra ; Smékalová, Monika (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Mentor: Mgr. Monika Smékalová, Ph.D. Consultant: MUDr. Michael Bartoš Student: Petra Řehořková Title of Thesis: Development of material for agar-based ultrasound brain phantom This thesis is concerned with the development of a material for an agar-based ultrasound phantom that would provide skill acquisition and experience in a manner approximating real surgery. The aim is to formulate and optimize the agar hydrogel preparation procedure, evaluate its acoustic properties and water loss during storage. A dependence was found between the amount of water evaporated during storage (4 weeks at 37 řC) and the glycerol content, which slows down the water loss from the samples in direct proportion. Based on the results, an agar gel (AG) formulation with 1% agar and 60% glycerol was selected for the acoustic properties measurements. During this experiment the microbial stability of AG was confirmed. The results of acoustic parameters measurements were evaluated, namely, speed of the ultrasound, attenuation coefficient and echogenicity of the samples as a function of content of scattering particles Al2O3 and SiC. It was shown that each type of particles affects grayscale value and attenuation coefficient in a...
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Development of material for agar-based ultrasound brain phantom
Řehořková, Petra ; Smékalová, Monika (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Mentor: Mgr. Monika Smékalová, Ph.D. Consultant: MUDr. Michael Bartoš Student: Petra Řehořková Title of Thesis: Development of material for agar-based ultrasound brain phantom This thesis is concerned with the development of a material for an agar-based ultrasound phantom that would provide skill acquisition and experience in a manner approximating real surgery. The aim is to formulate and optimize the agar hydrogel preparation procedure, evaluate its acoustic properties and water loss during storage. A dependence was found between the amount of water evaporated during storage (4 weeks at 37 řC) and the glycerol content, which slows down the water loss from the samples in direct proportion. Based on the results, an agar gel (AG) formulation with 1% agar and 60% glycerol was selected for the acoustic properties measurements. During this experiment the microbial stability of AG was confirmed. The results of acoustic parameters measurements were evaluated, namely, speed of the ultrasound, attenuation coefficient and echogenicity of the samples as a function of content of scattering particles Al2O3 and SiC. It was shown that each type of particles affects grayscale value and attenuation coefficient in a...
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Development of material for gelatin-based ultrasound brain phantom
Vaclaviková, Andrea ; Smékalová, Monika (advisor) ; Šklubalová, Zdeňka (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: Mgr. Monika Smékalová, Ph.D. Consultant: MUDr. Michael Bartoš Student: Andrea Vaclaviková Title od thesis: Development of material for gelatin-based ultrasound brain phantom There are more aspects that have an important role in selection of material for production of single-use ultrasound brain phantom: kind of material, acoustic property, price of materials and their accessibility, simplicity in preparation and its storage requirements, time stability and further. Gelatine as a hydrogel is a proper material for imitation of biological tissues since human body is mostly formed by water what is a prerequisite for acoustic and mechanical quality. Besides that, this natural biopolymer can be available for low costs. The goal was to find suitable combinations in proportion to gelatine, crosslinker, plasticiser, and preservatives in order to create material for ultrasound brain phantom with optimal time of solidification and similar acoustic property of brain in terminal stage. The emphasis was also put on temperature and microbiological stability requirements. For this purpose, there were arranged set of samples of 5%, 7,5% and 10% of gelatine with different proportion of...
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Studying protein interactions with expanded genetic code
Tekel, Andrej ; Obšil, Tomáš (advisor) ; Fuertes Vives, Gustavo (referee)
Nature, using proteins composed of approximately 20 amino acids repertoire, is able to perform a large number of admirable things, many of which we are still not quite able to mimic. However, it has to be said, that the set of chemical scaffolds available to the nature is somewhat limited. Therefore, it seems plausible to assume, that we could make things better simply by introducing novel scaffolds and exploring chemical space so far unavailable. It is exactly this idea upon which expanded genetic code is based on. To set ourselves free from limitations imposed by standard genetic code. This thesis will aim to provide an overview of various attempts to this problem and will try to do so in a distinct context of studying protein interactions. I will thus try to highlight methods by which we are currently able to expand genetic code, specific chemistries and physical properties of non-canonical amino acids and biophysical methods which can profit from genetic code expansion. Keywords: expanded genetic code, non-canonical amino acid, amber codon, fluores- cence, magnetic resonance, crosslinking, click chemistry
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