|
|
Experimental study and modelling of the transdermal penetration of active species from gels
Palanová, Veronika ; Opatřilová, Radka (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with design and experimental study of transdermal transport of pharmaceutically active agents from gel matrices, which contain humic substance in its structure. A model absorption membrane was represented by the skin of pig´s earlobes. The study of the release of active substances and Lignohumte was performed due to the vertical diffusion cells. The amount of released humic substance was characterized by UV-VIS method and the amount of released active agent from gel matrix was determined by HPLC-DAD. The most interesting finding of this diploma thesis was that Lignohumate enhances transdermal transport of active agents and supports their release from gel samples to the particular environment.
|
|
|
Synthesis of SiO2/Au core/shell nanoparticles for enhancement of OCT signal
Kantorová, Martina ; Kolář, Radim (referee) ; Drbohlavová, Jana (advisor)
The aim of this master thesis is synthesis of SiO2/Au core/shell nanoparticles. These nanoparticles should improve the signal of optical coherence tomography (OCT). The procedure of nanoparticle synthesis is described in the work. Synthetized nanoparticles were analyzed by scanning electron microscopy (SEM), Ultraviolet-Visible spectroscopy (UV-Vis), Near-infrared spectroscopy (NIRS), Fourier transform-infrared spectroscopy (FT-IR) and Dynamic light scattering (DLS). Then, the synthetized nanoparticles were tested for enhancement of OCT signal. For this testing were also used commercial nanoparticles with the same structure and similar size.
|
|
|
Possibilities of hexavalent chromium reduction within portland cement hydration
Mončeková, Miroslava ; Koplík, Jan (referee) ; Šoukal, František (advisor)
The issue of Hexavalent chromium toxicity to Portland cement hydration is a very actual these days. It takes much effort to obtain a cement containing Cr(VI) less than 2 ppm. The primary objective of this diploma theses is to find appropriate reducing substances and specify their efficiency, as well as to make an attempt to optimize their dosage. As reducing substances there were plumbed sulphites and tin(II) salts. The influence of reducing substances applied to the hydration and cement properties were validated by strenght tests, the calorimetric measurement and the volume-variation measurement. And also the changes in hydration products microstructure of Portland clinker after the gypsum replacement by sulphite ions were plumbed. The study of microstructure is based on SEM and XRD methods.
|
|
|
Influence of soil management on properties of humic substances
Rubínková, Eva ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The aim of the Diploma thesis is to consider an influence of soil management (rotation of crops on arable land and grassland) to quantity and quality of humic substances. These properties are depended not only upon way of soil management, but also upon climatic effects, such are rainfall, temperature, elevation above sea-level, level of underground water and content of clay. Significantly influenced factors are content and form of organic carbon which is very tightly bonded to humic substances. In this work the humic acids content and properties progression was studied in given time period. Also the effect of crop rotations to changes of physical and chemical properties of humic acids in soil environment was observed. Diploma thesis was realized in co-operation with Mendel University in Brno, which supplied elaborating samples. Studied soil samples were taken from humus horizon Cambisol modal Vatín during years 1999–2006, always in autumn. Individual samples were characterized by available analytical methods, which are generally used in humic substances research area. They are especially fluorescence spectrometry, UV-VIS and infrared spectrometry and acid-base and conductometric titrations.
|
|
|
Study of system based on phospholipids for sonographical application.
Überall, Martin ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
The aim of this thesis was to determine solubilizing capacity of surfactants and phospholipids using the UV-VIS spectrophotometry. The concentrations of solubilized substances within these systems was further determined. From the surfactant group, three representatives were selected, cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzenesulfonate (SDBS) and Triton X-100. From the phospholipid group, lecithin and commercially available SonoVue® were chosen. The solubilizing capacity was determined using hydrophobic solutes Sudan Red G (SRG), Oil Red O (ORO) and 1-naphtol in order to obtain a model system of solubilized drugs or vitamins which are also hydrophobic. The behavior of solutes in surfactants was determined in a moderate polar medium of physiological saline (0.15 M NaCl), the behavior of solutes in lecithin was conversely determined in Mili-Q water medium. The determined concentration of solubilized hydrophobic solutes inside the micelles of surfactants is within the range of tens to hundreds of micromoles per liter. With increasing concentration of surfactant increases the concentration of solubilized solutes. The results obtained in this work can be used for further experiments and research focused on solubilization of drugs in contrast agents used in ultrasonography.
|
|
|
In vitro study of antioxidant activity of food supplements
Vopelková, Dominika ; Pořízka, Jaromír (referee) ; Omelka, Ladislav (advisor)
Bachelor thesis deals with the determination of antioxidant activity of food supplements in vitro. The theoretical part focuses on legislative requirements of food supplements, their characteristic and classification. Further, the attention is also devoted to antioxidants, their properties, effects, importance and utilization. Separate chapter describes herbs, which are an essential component of researched supplements, their effects and properties. For experimental part several food supplements in various forms (capsule, tea, juice, dried fruits) were chosen and total content of polyphenols was determined using the UV-VIS spectroscopy. Further, the total antioxidant activity is characterized by electron paramagnetic resonance involving DPPH method.
|
|
|
Model delivery systems for poorly soluble drugs
Sapárová, Alica ; Holínková, Petra (referee) ; Pilgrová, Tereza (advisor)
The solubilizing capacity of micelle–hyaluronan system was studied using the UV-VIS spectrophotometry method. Septonex was chosen as a surfactant and four molecular weights of hyaluronan were used. Solubilization experiments with a hydrophobic dye Sudan Red G and Sudan III were performed in order to obtain a model system of solubilized drugs, which are also hydrophobic. The system was prepared in the environment of mili-Q water. The influence of the molecular weight of hyaluronan on the solubilizing ability has been studied. It was found that concentration of solubilized dyes increases by increasing concentration of micelles in the system and the molecular weight of hyaluronan affects the solubility of the dyes.
|
|
|
Stability of cross-linked collagen
Součková, Gabriela ; Vojtová, Lucy (referee) ; Jančář, Josef (advisor)
Teoretická část této bakalářské práce pojednává o obecných vlastnostech kolagenu, který je nejčastěji rozšířeným vláknitým proteinem v těle, o síťování kolagenu, které vede ke zlepšení mechanických i chemických vlastností, a o široce využívaných síťovacích činidlech, především 1-ethyl-3-(3-dimethylaminopropyl) karbodiimidu (EDC). Dále se zabývá několika metodami stanovení EDC ve vodném roztoku. Experimentální část je zaměřena na praktické stanovení množství EDC, které zůstalo ve vodě použité k promývání vzorků po síťování. Cílem bylo zjistit, jestli současně používaná metoda promývání je dostatečná pro jisté aplikace nebo je potřeba ji upravit. I přesto, že sloučenina EDC je prakticky netoxická, může způsobovat zbarvení kolagenních materiálů po sterilizaci ozařováním. Vzhledem k tomu, že nebylo zjištěno jaké množství EDC může ve vzorku zůstat nebo jestli je nezbytné vymýt veškeré EDC, je obtížné rozhodnout jestli je promývací metoda dostatečná nebo není. Navíc je potřeba brát do úvahy i ostatní vedlejší produkty síťování kolagenu. Nicméně cílem této práce bylo pouze zhodnotit účinnost vymývání EDC z kolagenních vzorků. Pro síťování byly použity tři různé koncentrace EDC a následně byly vzorky vymývány po různě dlouhou dobu. Takto bylo získáno 48 vodných vzorků, které byly následně třikrát spektrofotometricky stanoveny. Výsledně bylo zjištěno, že pro běžně používanou koncentraci síťovacího činidla (50 mmol.l 1 EDC) postačuje promývat vzorky po dobu 30 minut v roztoku hydrogenfosforečnanu sodného (Na2HPO3) a následně promývat ve vodě čtyřikrát po dobu 15 minut s výměnou vody při každém kroku. Po těchto krocích klesla koncentrace EDC v promývací vodě pod 1 mol . l-1, pro nižší koncentrace síťovacího roztoku byla dostatečná i kratší doba promývání. Výsledky této bakalářské práce jsou pouze předběžné, a proto by mělo následovat další zkoumání této problematiky.
|
|
| |
|
| |
guest ::
