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Using diffusion techniques in the study of hydrogels
Holubová, Anna ; Žitňan, Michal (referee) ; Mravec, Filip (advisor)
Properties of colloidal systems, especially hydrogels, were studied using the method of fluorescence correlation spectroscopy (FCS). Hydrogels were prepared based on hyaluronan and cationic surfactant CTAB interactions. The proposed hydrophilic fluorescent probe, suitable for the study of phase-separated hydrogels in polymer-surfactant systems, was chosen ATTO 488 due to the suppression of triplet state. As a hydrophobic probe was chosen Nile Red. Individually were examined micellar systems of 10 mM CTAB and 0,5% sodium hyaluronate in water and 0,15 M NaCl in different concentrations of selected fluorescent probes. Subsequently the hydrogel systems were studied. The results showed that the measurement of hydrogels by this method is realizable. Short lifetimes were created by a complex probe and CTAB causing quenching and low levels of diffusion coefficients characterize the viscous environment of study system.
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Time-resolved fluorescence study of liquid and condensed systems based on biopolymer-surfactant interactions.
Černá, Ladislava ; Žitňan, Michal (referee) ; Mravec, Filip (advisor)
This thesis studies properties of hydrogel, which arises on the basis of electrostatic and hydrophobic interactions between hyaluronan chain and micelles of cationic surfactant. A native sodium hyaluronan at molecular weight 750–1 000 kDa and a cationic surfactant CTAB (cetyltrimethylammonium bromide) were used. This hydrogel was assessed as a material for drug delivery systems. The hydrogels were made by mixing 200mM CTAB with 0.5% hyaluronan, both dissolved in 0.15M aqueous solution of NaCl simulating physiological solution. Methods used in this study were steady-state and time-resolved fluorescence spectroscopy, more accurately time-resolved emission spectra (TRES) and deconvolution of steady-state emission spectra of a whole sample by means of parameters gained from fluorescence intensity decays at a set of wavelenghts. Selected systems were investigated by three fluorescent probes, prodan, laurdan and rhodamine 6G. The first two mentioned probes were in hydrogel localized only within micelles in three different microenvironments. Rhodamine 6G pointed out that in hydrogel the aqueous environment is significantly restricted in comparison to purely micellar solution. In addition, rhodamine informed about less available micelle surfaces, caused by hyaluronan chains occupation. There were no interactions between the probes and hyaluronan chains. Freshly made hydrogels showed almost the same results as after a week of maturation under its supernatant.
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Autonomous vehicles driving simulation environments research
Žitňan, Michal ; Krejsa, Jiří (referee) ; Věchet, Stanislav (advisor)
This bachelor thesis focuses on an extensive search of simulation environments for autonomous vehicles. In the introductory section, the definition of AVs as well as the distribution of levels of autonomous driving is presented. This is followed by a description of the issues involved in simulating and testing AVs in the real world, with a focus on the use of simulators in this process. This is followed by the definition of criteria for comparing the 20 simulation environments investigated in this thesis, in terms of general information, environment, sensors and data labeling tools. The next chapters deals with a brief description of each simulation environment and other platforms involved in the AV development field, followed by a summary of the investigated information through tables. In the last section, two simulators are selected to describe the tasks required to implement an autonomous driving project in a simulator.
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Time-resolved fluorescence study of liquid and condensed systems based on biopolymer-surfactant interactions.
Černá, Ladislava ; Žitňan, Michal (referee) ; Mravec, Filip (advisor)
This thesis studies properties of hydrogel, which arises on the basis of electrostatic and hydrophobic interactions between hyaluronan chain and micelles of cationic surfactant. A native sodium hyaluronan at molecular weight 750–1 000 kDa and a cationic surfactant CTAB (cetyltrimethylammonium bromide) were used. This hydrogel was assessed as a material for drug delivery systems. The hydrogels were made by mixing 200mM CTAB with 0.5% hyaluronan, both dissolved in 0.15M aqueous solution of NaCl simulating physiological solution. Methods used in this study were steady-state and time-resolved fluorescence spectroscopy, more accurately time-resolved emission spectra (TRES) and deconvolution of steady-state emission spectra of a whole sample by means of parameters gained from fluorescence intensity decays at a set of wavelenghts. Selected systems were investigated by three fluorescent probes, prodan, laurdan and rhodamine 6G. The first two mentioned probes were in hydrogel localized only within micelles in three different microenvironments. Rhodamine 6G pointed out that in hydrogel the aqueous environment is significantly restricted in comparison to purely micellar solution. In addition, rhodamine informed about less available micelle surfaces, caused by hyaluronan chains occupation. There were no interactions between the probes and hyaluronan chains. Freshly made hydrogels showed almost the same results as after a week of maturation under its supernatant.
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Using diffusion techniques in the study of hydrogels
Holubová, Anna ; Žitňan, Michal (referee) ; Mravec, Filip (advisor)
Properties of colloidal systems, especially hydrogels, were studied using the method of fluorescence correlation spectroscopy (FCS). Hydrogels were prepared based on hyaluronan and cationic surfactant CTAB interactions. The proposed hydrophilic fluorescent probe, suitable for the study of phase-separated hydrogels in polymer-surfactant systems, was chosen ATTO 488 due to the suppression of triplet state. As a hydrophobic probe was chosen Nile Red. Individually were examined micellar systems of 10 mM CTAB and 0,5% sodium hyaluronate in water and 0,15 M NaCl in different concentrations of selected fluorescent probes. Subsequently the hydrogel systems were studied. The results showed that the measurement of hydrogels by this method is realizable. Short lifetimes were created by a complex probe and CTAB causing quenching and low levels of diffusion coefficients characterize the viscous environment of study system.
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