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Optimization of the MRI chicken embryos measurements
Sedláčková, Gabriela ; Dražanová, Eva (referee) ; Krátká, Lucie (advisor)
This thesis deals with optimization of MRI measuring of phantoms containing the chicken embryo. The theoretical part of thesis is dedicated to the MRI fundamentals and description of pulse sequences. In the next part the options of keeping and monitoring the temperature are being discussed. The thesis also deals with design and realization of phantoms which are used for measuring. A browser of images captured by MRI was programmed in Matlab environment. The program allows users to look through the images with different settings of pulses sequences or kind of phantom. The final part of thesis describes the anatomical structures of chicken embryo and discussion of collected results.
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Preparation and characterization of chitosan-based materials
Puchírová, Simona ; Kalina, Michal (referee) ; Kovalčík, Adriána (advisor)
The presented diploma thesis focuses on the characterization of the rheological properties of hydrogels based on agarose, alginate, polyvinyl alcohol and the study of the antimicrobial effect of chitosan added to selected hydrogels. The theoretical part is focused on the creating a literature research dealing with the description of the basic characteristics of hydrogels in general, describes the nature, properties, structure and possibilities of its use. In the experimental part, hydrogels without added active substance and hydrogels modified with chitosan were prepared. Based on rheological measurements, suitable combinations of hydrogels with chitosan were selected. A part of the hydrogel was taken from the samples and monitored in a drying and re-swelling process in distilled water. The hydrogels were tested by Ftir analysis, which verified the presence of chitosan in the samples. Monitoring of the antimicrobial effect of chitosan was performed by the hole diffusion method. Efficacy was tested on bacterial strains of Escherichia coli, Candida glabrata, Micrococcus luteus, Serratia marcescens. Most excised hydrogel disks have formed zones of inhibition of various sizes. Inhibition zones were also formed around hydrogels without chitosan, where the sensitivity of individual microbial cultures to acetic acid is assumed. The antibacterial active of chitosan was verified by studying the separate sensitivity of chitosan solutions and acetic acid.
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Preparation of edible antimicrobial packaging
Kozubová, Petra ; Dzurická, Lucia (referee) ; Skoumalová, Petra (advisor)
This bachelor’s thesis is focused on preparation and characterization of eatable packaging. Eatable packaging consists of two components, antimicrobial component and base of packaging. The task of eatable packaging is to protect product against antimicrobial attack and to extend durability of the product. As antimicrobial components were used water and oil extracts of several herbs (mint, nettle, lavender, cinnamon, cloves, vanilla, ginger and rhinoceros). Oil extracts were also encapsulated into liposomes for better application. Firstly, concentrations of polyphenoles and antioxidants of extracts were determined. Oil extract of clove contained the highest concentration of both determined substances. Encapsulation efficiency, stability and size of liposomes were tested too. All prepared liposomes were stable and relatively of the same size. Also high encapsulation efficiency was observed. Next, antimicrobial activity of prepared extracts and liposome particles against yeast Candida glabrata and two bacteria strains Escherichia coli and Staphycococcus epidermidis was tested and the high antimicrobial activity reported mainly all tested liposomes. Then alginate, chitosan and carboxymethylcellulose and their combinations respectively were used as bases of packaging. Created film had to meet several parameters, especially suitable sensory properties such as pleasant taste and smell, as well as invisibility, gloss, affordability and suitable manipulability. Combination of 2% carboxymethylcellulose and 1% alginate in a ration of 2:1 with liposomes of mint as antimicrobial component achieved the best results.
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Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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Preparation and characterization of chitosan-based materials
Puchírová, Simona ; Kalina, Michal (referee) ; Kovalčík, Adriána (advisor)
The presented diploma thesis focuses on the characterization of the rheological properties of hydrogels based on agarose, alginate, polyvinyl alcohol and the study of the antimicrobial effect of chitosan added to selected hydrogels. The theoretical part is focused on the creating a literature research dealing with the description of the basic characteristics of hydrogels in general, describes the nature, properties, structure and possibilities of its use. In the experimental part, hydrogels without added active substance and hydrogels modified with chitosan were prepared. Based on rheological measurements, suitable combinations of hydrogels with chitosan were selected. A part of the hydrogel was taken from the samples and monitored in a drying and re-swelling process in distilled water. The hydrogels were tested by Ftir analysis, which verified the presence of chitosan in the samples. Monitoring of the antimicrobial effect of chitosan was performed by the hole diffusion method. Efficacy was tested on bacterial strains of Escherichia coli, Candida glabrata, Micrococcus luteus, Serratia marcescens. Most excised hydrogel disks have formed zones of inhibition of various sizes. Inhibition zones were also formed around hydrogels without chitosan, where the sensitivity of individual microbial cultures to acetic acid is assumed. The antibacterial active of chitosan was verified by studying the separate sensitivity of chitosan solutions and acetic acid.
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Preparation of edible antimicrobial packaging
Kozubová, Petra ; Dzurická, Lucia (referee) ; Skoumalová, Petra (advisor)
This bachelor’s thesis is focused on preparation and characterization of eatable packaging. Eatable packaging consists of two components, antimicrobial component and base of packaging. The task of eatable packaging is to protect product against antimicrobial attack and to extend durability of the product. As antimicrobial components were used water and oil extracts of several herbs (mint, nettle, lavender, cinnamon, cloves, vanilla, ginger and rhinoceros). Oil extracts were also encapsulated into liposomes for better application. Firstly, concentrations of polyphenoles and antioxidants of extracts were determined. Oil extract of clove contained the highest concentration of both determined substances. Encapsulation efficiency, stability and size of liposomes were tested too. All prepared liposomes were stable and relatively of the same size. Also high encapsulation efficiency was observed. Next, antimicrobial activity of prepared extracts and liposome particles against yeast Candida glabrata and two bacteria strains Escherichia coli and Staphycococcus epidermidis was tested and the high antimicrobial activity reported mainly all tested liposomes. Then alginate, chitosan and carboxymethylcellulose and their combinations respectively were used as bases of packaging. Created film had to meet several parameters, especially suitable sensory properties such as pleasant taste and smell, as well as invisibility, gloss, affordability and suitable manipulability. Combination of 2% carboxymethylcellulose and 1% alginate in a ration of 2:1 with liposomes of mint as antimicrobial component achieved the best results.
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Adhesive properties of matrix tablets
Kišková, Martina ; Šnejdrová, Eva (advisor) ; Mužíková, Jitka (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of Pharmaceutical Technology Name: Martina Kišková Title of diploma thesis: Adhesive properties of matrix tablets Supervisor: PharmDr. Eva Šnejdrová, Ph.D. The diploma thesis deals with the evaluation of rheological and adhesive properties of the mucin, aqueous dispersions of polymeric carriers and matrix tablets based on chitosan and sodium alginate or iota-carrageenan loaded with the salicylic acid using absolute rotational rheometer. The theoretical part deals with the characterization and classification of matrix tablets, polymeric carriers (sodium alginate, chitosan and carrageenan) and with the principles of evaluation of rotational, adhesive and oscillational tests performed in the experimental part. The mucin from porcine gastric used as a model substrate for adhesion tests behaves as a viscoelastic solid and its adhesive strength decreases with increasing hydration. Significantly higher adhesive strength was found for chitosan at pH 1.2 and sodium alginate at pH 6.8 compared to the adhesive strength of iota-carrageenan. In terms of viscoelastic properties, chitosan and sodium alginate are viscoelastic fluids, but iota-carrageenan is a viscoelastic solid. Iota-carrageenan forms the stiffest gel after hydration at pH 6.8...
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Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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Optimization of the MRI chicken embryos measurements
Sedláčková, Gabriela ; Dražanová, Eva (referee) ; Krátká, Lucie (advisor)
This thesis deals with optimization of MRI measuring of phantoms containing the chicken embryo. The theoretical part of thesis is dedicated to the MRI fundamentals and description of pulse sequences. In the next part the options of keeping and monitoring the temperature are being discussed. The thesis also deals with design and realization of phantoms which are used for measuring. A browser of images captured by MRI was programmed in Matlab environment. The program allows users to look through the images with different settings of pulses sequences or kind of phantom. The final part of thesis describes the anatomical structures of chicken embryo and discussion of collected results.
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