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Interaction Between Hyaluronan and Amphiphilic Molecules
Venerová, Tereza ; Burget, Ladislav (referee) ; Čeppan, Michal (referee) ; Pekař, Miloslav (advisor)
This work is focused on interaction between hyaluronan (Hya) and amphiphilic molecules. Using fluorescent probes method were carried out screening of the interaction of various surfactants with Hya. For further examination was chosen cetyltrimethylammonium bromide (CTAB). Interactions in this system have also been studied using fluorescence correlation spectroscopy (FCS), and additionally were performed initial tests of the cytotoxicity of the system. As an alternative CTAB were also used hydrophobically modified amino acids. Results showed their self-aggregation, but their interactions with hylauronanem was not as strong as with CTAB. The interaction of gel systems Hya-CTAB have also been studied, and was found to contain a hydrophobic domain capable solubilize hydrophobic substance. Thermogravimetric have been established that are able to contain up to 98% wt. water and rheologically were characterized their mechanical properties. These are tunable due to molecular weight (MW) of the hyaluronate. With increasing value of MW increases mechanical strength of the gel and decreases its fluidity.
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Dialysis study of hyaluronan-surfactant interactions
Šejnohová, Michaela ; Venerová, Tereza (referee) ; Pekař, Miloslav (advisor)
This diploma thesis is concentrated on the interactions between polyelectrolyte (hyaluronan) and cationic surfactant (CTAB). The experiments were performed in an aqueous solution and in an environment of physiological ionic strength (0,15mmoldm-3 NaCl). The determination of the surfactant concentration in solutions was based on the formation of colored complexes of CTAB and picric acid in chloroform. The concentrations of surfactant were measured by UV-VIS spectroscopy. The stability of CTAB+HyA was examined by a dialysis method. The results showed that, regardless of the environment, the presence of HyA in solution reduces the number of free molecules of CTAB which can be determined in the sample. It has been proved that there is an interaction between HyA and surfactant and that CTAB has greater affinity for HyA then for the picric acid. The stability of CTAB+HyA was determined by dialysis of 120 hours. After that time, the concentrations of the retentate and permeate were settled. The results showed that in the membrane remains a certain amount of CTAB bounded to hyaluronan. The system can be suitable for the preparation of targeted carriers of biologically active substances.
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Modern conception of virtual class system
Outěřický, Pavel ; Průša, Zdeněk (referee) ; Pfeifer, Václav (advisor)
This thesis is focused on problems of an interactive distant education with usage of virtual classroom as a software communication tool. The short analysis of types of human communication and education is followed by a description of virtual classroom systems in a very basic point of view like what the virtual classroom is and what its usage is and what advantages these systems have. Furthermore, potentialities and supported tools and functions of today’s commercial and also non-commercial products are described including illustrative examples and focus to potential types of network communication implementation. Next section of the thesis presents possibilities of virtual classroom software development as completely web-based application or as desktop application where usage of different programming languages is considered. After that, videoconference as a often used tool in virtual classroom is described and its demands on the ways and types of realization and implementation are stated. The second part of this thesis creates about three quarters of whole document and is dedicated to description of my own realization of virtual classroom system as a built-in-java desktop application communicating across a built-in-java server desktop application. The first section of this part introduces a basic design and concept of the system including its implemented tools for the distant education. The following chapters describe in details each implemented tool and function from the potential user point of view and also developer point of view.
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Computational modelling of interaction between oscillating vocal folds and air flow
Pavlica, Ondřej ; Matug, Michal (referee) ; Švancara, Pavel (advisor)
Master thesis deals with creating numerical model of the human vocal folds. Calculation algorithm includes interaction between vocal chords and the air flow. Modal analysis of structural and acoustic environment, backround research of vocal folds function and summary of some published overviews of numerical models are parts of this work. Analysis of the results achieved by the numerical simulations and calculations are focused on the pressure and velocity conditions in the areas under vocal folds, between vocal folds and above vocal folds. Movement and stress analysis of individual layers of vocal folds has been made. Impact of tissue thickness on resulting behaviour has been assessed.
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Hyaluronan hydrogels for medical applications
Janča, David ; Krouská, Jitka (referee) ; Venerová, Tereza (advisor)
This work studies properties of hydrogels prepared by the interaction of polyelectrolyte hyaluronate with cationic surfactant cetyltrimethylammonium bromide (CTAB) in a model physiological solution of 0,15 M NaCl. Effects of different pH and final pH of different samples of hydrogels were studied. Furthermore, stability of hydrogels was observed by fluorescence spectroscopy, where pyrene was used as a fluorescence probe, and isothermal microcalorimetry. It was found that low temperature disrupts gel integrity and it is not recommended to expose hydrogels to other than a neutral pH.
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Influence of molecular weight of polymers on phase-separated hydrogels
Kolomá, Nikola ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on study of individual systems of hyaluronan mixtures. All mixtures of hyaluronans they were ready at molecular weights of 15-30 kDa, 80-150 kDa, or 1500-1750 kDa. These individual molecular weights were combined in different ratios most often in ratios of 70:30, 50:50 and 30:70. Septonex surfactant was used for all mixed samples and CTAB was used for last experiment too. At first the gel samples were prepared by a dry route of individual powders with accurately calculated batches. All solutions were prepared wet route with stock of exactly calculated concentration. Physical gels were prepared by combinations of Septonex and hyaluronan with the different molecular weights. In solution formed irregular shapes which we could describe as "marbles" or "beads". After the sample was to stand, the individual „marbles“ of the gel were formed whole mass. Was done too many experiments with physical gels, which has been carried out behavior of mixtures hyaluronans with different molecular weights. All physical and chemical properties were observed by the eye, described and in the and were photographed. Was used hydrophil dye in experiments and served for better visualize comparison samples between themselves. The last experiment was rheological measurement with which is possible characterize viscosity od individual samples.
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Study on interactions of protonated aminoacids with low-molecular weight hyaluronan
Chlumská, Jana ; Kalina, Michal (referee) ; Chytil, Martin (advisor)
This bachelor thesis deals with interactions between hyaluronic acid (HA) of low molecular weight (110-130 kDa) and protonated aminoacids lysine and 6-aminocaproic acid. For investigation of these interactions, methods such as pH-metry, conductance measurement, viscometry and dynamic light scattering were used. The electrostacic interactions between carboxylic group of HA and the aminogroup of the aminoacids are presumed. Proving these interactions would allow us to physically modify HA and further more, using such a system as a carrier of pharmaceuticals. The interactions of protonated lysine with HA were studied in pure water or in the solution of NaCl (c = 15 mmol•dm-3). Interactions of 6-aminocaproic acid were studied only in pure water. Both aminoacids were in the concentration range 0.9-20 mmol•dm-3. The decrease in the viscosity of the solutions indicates the interactions for lysine; for 6-aminocaproic acid the interactions also occured, but not as signifciantly as for the system containing lysine.
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Study on interaction of humic substances with surface active agents
Bělušová, Anna ; Krouská, Jitka (referee) ; Smilek, Jiří (advisor)
This bachelor thesis deals with the study of interactions between humic acids (HK), as the main component of soil organic matter, and model pollutants in the form of surfactants through unconventional and original combination of dialysis and diffusion techniques. Since dialysis techniques are rarely used for the interaction of humic substances with surfactants study, it was necessary to optimize methods for determining of ionic surfactants (cationic Septonex and anionic sodium dodecylsulfate were selected as representatives) prior to begining of own experiments, using a method based on the color ion pair creation between a surfactant and a counter-charged dye, followed by this pair extraction into an organic solvent. Diffusion cell dialysis experiments were performed with cationic surfactant Septonex, which was expected to interact positively with humic acids relative to its charge. As humic acids representatives, the standards of these substances provided by the International Society for Humic Substances (IHSS) were selected, namely humic acids (IHSS HK) isolated from Leonardite (1S104H). One of this bachelor thesis aims was to verify the effect of carboxylic functional acids on reactivity and barrier abilities of humic acids. For this reason, these standards have been modified by the selective methylation of carboxyl groups which no longer participate in the interaction with surfactants. Already from the first experiments there was a noticeable decrease in the concentration of Septonex over time – it means its transition through the dialysis membrane to humic acids, which indicates a positive affinity of humic acids to Septonex. The extent of these interactions was assessed through the apparent interactions parameter app through which the assumption that IHSS HK reacted with Septonex more than their methylated form of MIHSS HK was verified.
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Sound installation
Vacek, Lukáš ; Frank, Jakub (referee) ; Ambrůz, Jan (advisor)
In my bachelor thesis, I tried to evaluate my experience with working with sound, vibrations and the way they spread through different types of material. Examine the characteristics of the material and its properties through a minimalist form and through a targeted reduction of the vibrations themselves, while observing how they affect human perception. The fundamental concept of the installation is derived from this relationship. I am fascinated by how vibration and sound in space can create a situation that engulfs the viewer. The significance and the symbolism of this correlation, i.e. the ability of sound to create, distort and transform space and the way humans perceive this action is the main concept of my bachelor thesis. The vibrations represent the constant movement, change and uncertainty that are key aspects of this installation, but also of human existence and its perception. The scenographic nature of the artwork illustrates and alters the space around it with its audiovisual features, giving the impression of its own imaginary architecture. This creates a dynamic dialogue between the objects, which mutually vibrate and resonate through connections between the space and the audience.
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Interaction design with regards to the end user
Macura, David ; Walek, Agata (referee) ; Sedláček, Pavel (advisor)
Tato práce je zaměřena na uživatelská rozhraní, postupy spojené s jejich návrhem a vývojem a interakci mezi počítači a uživateli. Jejím cílem je kodifikovat a prozkoumat nejvýznamnější z těchto postupů a jejich vliv na výsledné produkty, dále popsat teoretickou stránku procesu návrhu a přístup designerů a uživatelů k designu a interakci. V části zaměřené na uživatelská rozhraní má práce za cíl prozkoumat a porovnat vybrané přístupy k tvorbě rozhraní a zmínit nejdůležitější vlivy na požadavky týkající se vývoje rozhraní pro aplikace.
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