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Voltammetric detection of 27-hydroxycholesterol on boron-doped diamond electrode
Michnová, Kristýna ; Schwarzová, Karolina (advisor) ; Nesměrák, Karel (referee)
The aim of this bachelor thesis was to study the voltammetric behavior of 27-hydroxycholesterol using boron-doped diamond electrode. The influence of several factors on the current response of 27-hydroxycholesterol was investigated: the effect of the supporting electrolyte, concentration of perchloric acid, polarization rate, water content, and pH effect. The study was conducted using cyclic voltammetry in a perchloric acid or sodium perchlorate in acetonitrile. 27-hydroxycholesterol provided a current response in the anodic region with a potential around +1450 mV vs. Ag/0.01 mol l-1 AgNO3 in 1 mol l-1 NaClO4 in acetonitrile in the presence of 0.1 mol l−1 perchloric acid in acetonitrile (water content 0.43 %) and 0.1 mol l−1 sodium perchlorate in acetonitrile. Furthermore, concentration dependence was measured using differential pulse voltammetry resulting in a limit of detection (LOD) of 2.71 μmol l−1 and a limit of quantitation (LOQ) of 9.04 μmol l−1 . It was demonstrated that the direct current voltammetry method does not achieve comparable limit values. Key words 27-hydroxycholesterol, boron-doped diamond electrode, oxidation, oxysterols, voltammetry
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Media influence on deciding of the possibilities of spending free time
Michnová, Kristýna ; Köppl, Daniel (advisor) ; Šťastná, Lucie (referee)
The aim of thesis "The media impact on the decision of the possibilities of spending freetime" is to determine through what channels, public gathers informations about leisure opportunities. It can help the centers of freetime to get media exposure as an opportunity for their development to help freetime centers to perceive media as an opportunity for their further development. Theoretical part introduces readers with the theme how media acts with society, especially with family, children and parents. It also deals with freetime time centers, the reader will be familiar with their characteristics for a good orientation in the following practical part. It also deals with various tool of so- called "communication mix", which is then applied in the practical part of the draft, as an "Communication strategy of DDM in Prague 9". The experimental part is based on a statistical methods of market research, particularly a questionnaire survey. This market research dealt with the effects of media on people's freetime in three locations - Prague, Zlín and Mikulov. Those three places were chosen as representatives of different sized cities; the assumption is, that freetime behavior of their inhabitants may vary. Practical part presents the results of market research, which can serve as a basis for planning of...
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