|
|
Fractional composition of metal ions in humic gels
Potočková, Jana ; Gregorová, Eva (referee) ; Klučáková, Martina (advisor)
This thesis deals with bond strength of metal ions in humic gels. Several samples of humic acids were studied to consider influence of samples isolation process and their consequent characteristics on bond strength of metal ions in their complexes. Some functional groups was blocked by methylation at some samples. Amount of active functional groups in individual samples was determined by standard titration methods. Metal ions bound in humic complexes were divided into several fractions by extraction with different reagents (distilled water, 1M MgCl2, 1M HCl and 0,025M NH4EDTA). Two extraction methods were used: sequential and fractional. During the fractional extraction leaching of metal ions always proceeds in single agents from original komplex, whereas during the sequential extraction leaching proceeds gradually in all extraction agents in order according to rising afinity of agents, i.e. bond strength of metal ions in samples. Amount of metal ions in leaches after extractions was analysed by UV-VIS spektrometry.
|
|
|
The influence of humic acids methylation on the interaction of surface active agents
Bělušová, Anna ; Weidlich, Tomáš (referee) ; Smilek, Jiří (advisor)
The presented diploma thesis deals with the study of interactions between humic acids as the main component of soil organic matter with a model organic pollutant presented by cationic surfactant Septonex (which was expected to interact positively with humic acids due to its charge) through unconventional combination of dialysis and diffusion techniques realized in diffusion cells together with isothermal titration calorimetry capable of elucidating the nature of ongoing reactions from a thermodynamic point of view. The experiments were performed with a humic acid isolated by standard isolation procedure from Leonardite (1S104H) purchased from the International Society for Humic Substances, with humic acids isolated from lignite as well as modal chernozem. The aim of the submited diploma thesis is to assess the influence of carboxyl functional groups in the structure of humic acids to interactions with Septonex. For this reason, said samples of humic acids have been modified by selective methylation of their carboxyl functional groups, which can no longer participate in interactions with ionic substances. Results from diffusion cells and isothermal titration calorimetry confirmed the assumption that Septonex interacted with all types of unmodified humic acids more than with their methylated derivatives. Despite the available literature, it was surprising that the differences in the interaction of humic acids with Septonex were not diametrically different when comparing unmodified humic acids with their methylated derivatives. The extent of these interactions was assessed through the apparent equilibrium constant Kapp determined in the diffusion (dialysis) experiments and from the course of enthalpy curves from isothermal titration calorimetry. After the experiments and their evaluation, it can be concluded that humic acids and Septonex in their interactions, due to their structures, probably apply not only electrostatic interactions, especially through available carboxyl functional groups of humic acids and positively charged hydrophilic parts of Septonex molecules, but also a significant role have a hydrophobic effect, hydrogen bonds and Van der Waals forces.
|
|
|
Localization of Methylation Sites in Transposons
Kmeť, Miroslav ; Martínek, Tomáš (referee) ; Vogel, Ivan (advisor)
This master's thesis deals with the creation of a tool for the extraction of methylation level from transposon sequences. Transposons are DNA elements with ability to move or copy themselves and their activity is regulated by DNA methylation. Sequence methylation information is stored in the bisulfite data and their processing is done with parts of two existing tools in a combination with implemented modules. Created tool takes into consideration unique challenges brought in the methylation calling process by transposable elements and it's functionality is presented on a set of experiments with simulated and real data.
|
|
|
Preparation and characterization of hydrogels based on cationic biopolymer
Tesařová, Barbora ; Mravec, Filip (referee) ; Smilek, Jiří (advisor)
Presented thesis deals with the preparation and characterization of hydrogels based on positively-charged biopolymer and negatively-charged tenside. As an appropriate representative of positively-charged polymer was chosen chitosan, because of his biocompatibility and biodegrability, and N,N,N-trimethylchitosan, which was synthetised from chitosan in this diploma thesis. The final product of synthesis was characterised by SEC-MALS, elemental analysis, infrared spectroscopy and nuclear magnetic rezonation. Interactions between these polymers and representatives of negatively-charged tensides, which are sodium dodecylsuphate and sodium tetradecylsulphate, were investigated. The main method used in this thesis was rheology, through it were investigated prepared hydrogels based on chitosan and tensides and also prepared microgels based on N,N,N-trimethylchitosan and tensides. The interactions between polymers and tensides have been proved.
|
|
|
Characterization of methylated humic acids
Solná, Irena ; Kislinger, Jiří (referee) ; Klučáková, Martina (advisor)
The main concern of this bachelor thesis was a characterization of the properties of methylated humic acids. Retrieval on modifications of acidic functional groups of humic substances was done. In addition appropriate experimental methods for assessing the impact of methylation of carboxylic groups of humic acids were selected. Methylation of formentioned carboxylic groups is used to improve stability of humic acids while working with them. The sample of methylated humic acids, produced by the University of Poitiers in France, was investigated by the following methods: UV-Vis spectroscopy, FT-IR spectroscopy, fluorescence spectroscopy and thermal analysis - TGA, DSC. The degree of methylation of carboxylic functional groups of methylated humic acids was considered using an indirect titration. Results were trade-off with the sample without methylation. The impact of gelation on properties of methylated and non-methylated humic acids was also studied.
|
|
|
Electrochemical biosensor for the study of DNA methylation
Petrula, Jakub ; Hrdý, Radim (referee) ; Hynek, David (advisor)
This bachelor’s thesis deals with design and optimalisation of custom biosensor for detection of methylated DNA. Teoretical part explains the mechanism and importance of DNA methylation. Next section describes analytical methods used in connection with DNA methylation and some basic direct and indirect methods of detection. Final part is dedicated to experiment itself, which is divided into several sections. Section one deals witch modification of working electrode and optimalisation of detection method. Second section introduces two different ways of DNA methylation detection. First is based on direct detection and second one on detection through the biosensor. Final part shows determination of methylcytosine from sample based on analysing characteristic attributes of signal and numeric algorithm based on curve fitting.
|
|
|
Utilization of Diffusive Techniques in Study on Reactivity of Biocolloids
Kalina, Michal ; Maršálek, Roman (referee) ; Mráček, Aleš (referee) ; Klučáková, Martina (advisor)
The main aim of this thesis is the utilization of simple diffusion techniques for the study on transport properties of copper ions in the systems containing humic acids with respect to the other parameters, which can affect the process (the structure of diffusion environment, the interactions between transported specie and diffusion matrices, selective blocking of binding sites of humic acids). The first part of experimental works was focused on characterization of studied materials (humic acids, humic sol and humic hydrogel). The main part of the thesis was dealing with the optimization of simple diffusion techniques, which were suitable for the study on transport of copper ions in matrices containing humic acids, taking into account the mutual interactions between studied components in the system. The obtained diffusion characteristics were compared to the data determined using sorption experiments. Consequently, the minor goal of the experimental works of this thesis was also the assessment of the influence of basic physico-chemical parameters of studied materials on transport phenomenon.
|
|
|
Influence of reactivity on transport of metal ions in humic gels
Smitalová, Michaela ; Pabst, Willi (referee) ; Klučáková, Martina (advisor)
This diploma thesis deals with copper(II) ions diffusion in the humic hydrogels. The hydrogels were prepared from several samples of humic acids using different method and their isolation conditions from the original matrix. A selective blocking of functional groups (COOH, OH) was performed in the selected samples of humic acids. These reactive groups were selectively blocked using methylation agent trimethylsilyl-diazomethane. The success of performed methylation and functional groups blocking was verified using a FT-IR spectroscopy. There was carried out the set of diffusion experiments. The experimental arrangement was selected to enable an instantaneous planar source met-hod for data processing. The basis of this method was to determine the copper(II) ions con-centration distribution in the hydrogels. The method consists of slicing of the hydrogels after the diffusion experiments, extraction of the copper ions in the solution and determina-tion of concentration in the extracts from individual slices using UV-VIS spectroscopy. Based on the experimental data the effective diffusion coefficients were determined. The resulting values include both the effect of hydrogels structure and the effect of the reaction between Cu(II) ions and humic acids. There were prepared gels with defined portion of blocked functional groups for selected samples, which allowed to investigate the effect of reactivity on the copper ions diffusion without the significant changes in the gel structure (porosity). The blocking of functional groups reflected in a lower values of diffusion coefficients in comparison to the gels prepared from unmodified humic acids as follows. There was also confirmed the effect of humic acids isolation procedure and their properties on the diffusivity.
|
|
|
Typing of bacterial populations based on methylation site detection
Hlavatá, Kristína ; Sedlář, Karel (referee) ; Škutková, Helena (advisor)
Táto bakalárska práca sa zameriava na detekciu metylácií DNA a vývoj metodiky typizácie bakteriálnych kmeňov. DNA metylácie hrajú kľúčovú úlohu ako regulačný mechanizmus v genóme, ktorý ovplyvňuje konečné vlastnosti organizmov. Použili sme DeepSignal2 na detekciu metylačných vzorov v 10 kmeňoch Klebsielly pneumoniae. Okrem toho sme navrhli metódu typizácie na základe identifikovaných metylácií pre kategorizáciu bakteriálnych kmeňov. Táto práca prispieva k zlepšeniu našeho chápania regulačných mechanizmov v bakteriálnych genómoch a predstavuje nový prístup k typizácii kmeňov pomocou vzorov metylácie DNA. Poskytuje cenné poznatky o charakterizácii a klasifikácii bakteriálnych kmeňov na základe ich metylómov.
|
|
|
Typing of bacterial populations based on methylation site detection
Hlavatá, Kristína ; Sedlář, Karel (referee) ; Škutková, Helena (advisor)
Táto bakalárska práca sa zameriava na detekciu metylácií DNA a vývoj metodiky typizácie bakteriálnych kmeňov. DNA metylácie hrajú kľúčovú úlohu ako regulačný mechanizmus v genóme, ktorý ovplyvňuje konečné vlastnosti organizmov. Použili sme DeepSignal2 na detekciu metylačných vzorov v 10 kmeňoch Klebsielly pneumoniae. Okrem toho sme navrhli metódu typizácie na základe identifikovaných metylácií pre kategorizáciu bakteriálnych kmeňov. Táto práca prispieva k zlepšeniu našeho chápania regulačných mechanizmov v bakteriálnych genómoch a predstavuje nový prístup k typizácii kmeňov pomocou vzorov metylácie DNA. Poskytuje cenné poznatky o charakterizácii a klasifikácii bakteriálnych kmeňov na základe ich metylómov.
|
guest ::
