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Study on the Mobility of Selected Representatives of Pharmaceuticals in Natural Systems
Bednárová, Paula ; Pořízka, Jaromír (referee) ; Kalina, Michal (advisor)
This diploma thesis focuses on interactions of chosen pharmaceuticals with soil and study their mobility. First part is devoted to the characteristics of the most common pharmaceuticals that appear in the environment, specifically antibacterial chemoterapeutics and analgetics. Subsequently, the occurrence of the pharmaceuticals in environment, their sources and effects are described. Further, the work focuses on soil components and soil organic matter. In conclusion of the theoretical part is the description of used analytical method for processing of the results and also the current state of the problematics. In the practical part of the thesis the experiments were made and analyzed and further served for better understanding of adsorption and interactions of chosen pharmaceuticals with soil and humin acids as the main reactive part of the soil.
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Study and characterization of organic substances in a biochar sample
Vojáčková, Beáta ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis characterizes biochar from a physico-chemical point of view. The theoretical part deals with biochar as a soil conditioner, its properties, use, production, and last but not least, effect of its sorroundings. For better characterization of organic and inorganic matter a phosphate buffer was used. This buffer ensures their specific extraction due to a neutral pH. The second path is to use rainwater, which simulates the condition of the soil environment. In the experimental part are discussed both; purified buffer-extracted samples and rainwater samples, which were studied by thermogravimetric analysis (TGA), elemental analysis (EA) and by infrared spectroscopy with Fouier transform (FTIR-ATR). Conductivity and pH were also measured. Moisture and ash content, which represent the inorganic non-combustible fraction, were determined using thermogravimetry. The extraction yields were converted to ashless wt. % based on these values. Results of EA provided us with information on the content of biogenic elements and basic physico-chemical characteristics of biochar. In contrast, the FTIR method defined the presence of individual functional groups and specific constitutive units, which are present in the extracts. This information allows us to better understand the environmental impact of biochar on the soil ecosystem.
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New amphiphilic ion pairs for the preparation of vesicular systems
Strnadová, Martina ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
The bachelor thesis is focused on the preparation of the new vesicular systems. The aim of this work is to create the most stable system and find out the most optimal working method for its production. The compared parameters were the energy used for dispersion, the molar percentage of cholesterol added, and the type of double-stranded positively charged surfactant. The whole system consisted of negatively charged surfactant sodium dodecyl sulfate and positively charged surfactant septonex. Each system was compared over time to determine stability based on the size of the particle, zeta potential, and turbidity of the solution. By the method of dynamic light scattering, particle size and polydispersity coefficient were measured. On the other hand, the zeta potential was determined by electrophoretic light scattering. The result of the thesis presents the most suitable parameters of ultrasonic dispersion, the molar proportion of cholesterol, and the use of cationic surfactant. Based on these parameters, it is possible to create a physically stable system for a long period of time, thanks to which such a system can be used in the future for other applications.
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Preparation and characterization of hybrid hydrogels matrix
Magera, Lukáš ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
Submitted bachelor’s thesis aims for preparation and subsequent optimisation of hybrid hydrogels, which represent material with high application potential because of their unique properties. Hybrid hydrogels have extraordinary mechanical resistance and other beneficial properties (e.g. transportation) due to their unique hybrid network structure, strong interpenetrating network entanglement and efficient energy dissipation system. This work engages in chemically-physically crosslinked hybrid gel, namely the combination of alginate-polyacrylamide. The hybrid hydrogel was formed and then underwent the tests of drying and swelling. The main purpose of the experimental part was to determine viscoelastic properties of hybrid hydrogels using standard oscillation tests. Swelling tests showed that the hybrid network containing limitedly swelling alginate gel reaches lower degree of swelling than the single unlimitedly swelling polyacrylamide gel. Viscoelastic tests unveiled an influence on the mechanical properties by value augmentation of the hybrid gel´s storage modulus in comparison with the reference alginate hydrogel. Hybrid hydrogel reported an increase in the linear viscoelastic area compared to the reference polyacrylamide gel, whose hybrid structure prevents from creating microcracks, that caused earlier rupture of the reference polyacrylamide gel.
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Utilization of flow-coulometry in study of transport metal ions in humic gels
Kalina, Michal ; Pabst, Willi (referee) ; Klučáková, Martina (advisor)
This diploma thesis deals with the study of non-stationary diffusion of cupric ions in humic gels. The main objective of the work was the optimalization of conditions for using the electrochemical analyzer EcaFlow 150 GLP for the study of diffusion experiments. Next part was focused on reaching of constant concentration profiles of cupric ions in humic gel. Last aim of the study was the bond strength between cupric ions and humic acids. Diffusion was characterized by the values of the diffusion flux and cupric ions concentration profiles in humic gel. The data necessary for calculation were obtained by the electrochemical analyses of the extracts of each slice after diffusion on the EcaFlow 150 GLP. It has been proved that after application of several adjustment is this method suitable for the study of diffusion experiments. By using of different extraction agents was obtained the fractionalization of cupric ions according to the bond strength to humic acids.
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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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Barrier properties of hydrogels
Královič, Michal ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
The main objective of this thesis is to judge the barrier properties of hydrogels. It was examined in total six kinds of agarose hydrogels, of which five kinds of gels was enriched with humic acids isolated from various sources. Humic acids were selected from IHSS standards, specifically Leonardite, Elliott Soil, Suwannee River, Pahokee Peat and Nordic Lake. Using UV-VIS spectrometry, copper ion concentrations were used to serve as a diffusion solution. Results of diffusion coefficients were evaluated by several diffusion methods. The method of diffusion in the plane of the board and three possible diffusion solutions of the constant source were used.
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Utilization of Light Scattering for the Study on the Structural and Conformation Changes during the Interaction of Biopolymers
Dobiášová, Andrea ; Hurčíková, Andrea (referee) ; Kalina, Michal (advisor)
The aim of this bachelor thesis was to study structural and conformation changes during the interaction of biopolymers by ligth scattering methods. This study was focused on hyaluronic acid with two molecular weights 250 – 450 kDa and 1500 – 1750 kDa, on sodium alginate and dextran hydrochloride (DEAE). NaCl, CaCl2 and BSA were used as interacting agents. Simple physical-chemical methods, like UV-VIS spectrometry, dynamic and electrophoretic light scattering, were used in experimental part. The main used method for these purposes was size exclusion chromatography coupled with light scattering and viscosimetry detectors. The studied characteristics of experiment were molecular weight, gyration and hydrodynamic radius, zeta potential and coefficients of conformation and Mark-Howinks diagrams. Interactions have been proved between negatively charged polyelectrolytes and additives. NaCl practically did not interact with any polysaccharide, only increasing ionic strength. Positively charged dextran interacted only with the BSA, despite having the same charge.
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Study of barrier and transport properties of polyelectrolytes using diffusion techniques in hydrogels
Valentová, Kristýna ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This diploma thesis was focused on study of barrier and transport properties of selected polyelectrolytes in hydrogel matrices by using diffusion techniques. The study of these properties was performed in horizontal diffusion cells where is observed the change in diffusion probe concentration over time. Diffusion experiments were performed on an agarose hydrogel with the addition of alginate, hyaluronic acid, polystyrene sulfonate, humic acids and as a model probe rhodamine 6G was used. Important parts of this thesis are also the methods which characterize the substances and hydrogel matrices such as rheology and potentiometric titration. The main aim of this diploma thesis was to investigate the effect of interactions between passing model dye (rhodamine 6G) and the appropriate gel (agarose + polyelectrolyte) on the fundamental diffusion parameters (effective diffusion coefficient, lag time, etc.).
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Optimization of the Methodology for Assessment of Biochar Effect on the Growth of Model Plants
Štorková, Natálie ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
This bachelor thesis is studying the effect of biochar on the growth of model plant and deals with the optimalization of the methods for assessing its impact. Theoretical part describes the properties and utilization of soil conditioners, special attention is focused on biochar. According to the literature research, maize (Zea mays) was chosen as a model plant for cultivation experiment and subsequently the application doses of biochar were also defined. The cultivation experiment took place in growing box under controlled illumination and irrigation. Plant dry weight weighing after cultivation, continuous measurement of plant height during the cultivation and also image analysis of the root system were used for evaluating the influence of biochar on quantitative and qualitative properties of model plants. From obtained data it can be summarized that the growth differences were influenced by the application dose, the type of biochar and also by type of soil, which was used for the cultivation experiment.
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