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The impact of the absence of physical education lessons on results of motor tests in elementary school children
Vosáhlová, Jana ; Pavlů, Dagmar (advisor) ; Opatrná Novotná, Irena (referee)
Author: Bc. Jana Vosáhlová Title: The impact of the absence of physical education lessons on results of motor tests in elementary school children Goals: The aim of this work is to determine the effect of the absence of physical edu- cation classes on the results of motor tests, specifically on the results of the UNIFIT- TEST test battery (6-60) and on leisure time physical activity of primary school children aged 9-14 and to compare the results obtained with the results of a previously performed study which was carried out in the period during which physical education was taught in the usual way. Methods: A total of 87 children aged 9 to 14 (47 girls and 40 boys) from Husova 170 Elementary School in Jičín participated in the study. Pupils were tested using the UNIFITTEST test battery (6-60) from motor tests (standing long jump, repea- ted sit-ups, endurance shuttle running, shuttle running) and somatic measurements. However, due to the closure of schools as a result of the serious epidemiological situation, it was not possible to complete the entire motor test battery. Another part of the study was a questionnaire survey focused on the child's leisure activity during the coronavirus and summer holidays. Results: The negative effect of the absence of physical education was manifested only in the...
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Study of redox reactions and adsorption of 4-nitrophenyl triazole labeled nucleosides and cresols on boron doped diamond electrodes for development of electroanalytical methods
Vosáhlová, Jana ; Schwarzová, Karolina (advisor) ; Havran, Luděk (referee) ; Navrátil, Tomáš (referee)
In this work, the application of boron-doped diamond electrodes with various surface pre- treatment were tested on selected oxidizable and reducible model compounds, specifically para and ortho cresols and 2'-deoxycytidine and 7-deazaadenosine labeled by 4-nitrophenyl triazole. The aim of the study was the investigation of electrochemical and adsorptive processes with respect to the development of electroanalytical methods of detection of the selected compounds, or utilization of boron-doped diamond electrodes as detectors in liquid-flow systems. Cresols were used as the model oxidizable compound. On O-terminated and polished boron- doped diamond electrodes, cresols provide oxidation signal owing to their oxidation to methylphenoxy radical at comparable potentials as on other carbon-based electrodes used as a reference in this work, i.e., glassy carbon electrode, pyrolytic graphite electrode, and carbon paste electrode. These carbon electrode materials show relatively high propensity to adsorption of reaction products, while such adsorption is minimal on boron-doped diamond. In situ anodic activation allows for a rapid regeneration of boron-doped diamond surface prior to each scan. A differential pulse voltammetric method that was developed with a detection limit of 0.61 mol∙l-1 to 2.97 mol∙l-1...
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Boron-doped diamond electrodes: Utilization for determination of reducible organic compounds
Vosáhlová, Jana ; Schwarzová, Karolina (advisor) ; Dejmková, Hana (referee)
In this study the possibilities of utilization of boron-doped diamond (BDD) electrodes for electrochemical reduction of organic compounds and their determination in aqueous media were investigated. For this purpose BDD electrodes have several advantages (relative wide potential window in cathodic region, low sensitivity towards oxygen evolution) but are not frequently used. For the study were selected biologically active organic compounds with typical reducible groups. Vanillin (natural essential oil, synthetic aroma; reducible aromatic aldehyde) is not reducible at BDD electrode. Azidothymidine (antiviral drug; reducible azido group) shows voltammetric signal in Britton -Robinson buffer at pH 6.0 - 8.0, but its analytical utilization is difficult due to the close positioning to the decomposition of the supporting electrolyte. The height and potential of the reduction signal of 5-nitroquinoline (environmental pollutant; reducible nitro group on the aromatic nucleus and at higher potentials reducible heterocycle) is significantly influenced by the boron concentration in BDD film. Reduction of quinoline skeleton is visible in the range of pH6.0 - 11.0 in BR buffer. For differential pulse and DC voltammetry (reduction of nitro group) in BR buffer pH 5.0 limits of detection 0.2 µmol.l-1 and 2.7...
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The influence of boron concentration on electroanalytical performance of boron-doped diamond electrodes
Vosáhlová, Jana ; Schwarzová, Karolina (advisor) ; Navrátil, Tomáš (referee)
This work aims at the investigation of the influence of boron concentration in boron doped diamond (BDD) thin films on their electrochemical performance in electroanalysis. BDD thin films used in this work were prepared in Department of Functional Materials, Institute of Physics AS CR. BDD films were prepared by microwave plasma-assisted chemical vapor deposition. Films were deposited on silicon wafers and the concentration of boron was introduced by variable B/C ratio in the gas phase in the range from 500 ppm to 8000 ppm. Redox systems [Fe(CN)6]4-/3- and [Ru(NH3)6]3+/4+ were used for characterization of the BDD films by cyclic voltammetry. It has been proven that the anodic oxidation of BDD thin films at the potential of + 2,4 V in acidic solution stabilizes the quasireverzible response of these redox systems. Further, the potential window at the cathodic side is shorter with increasing boron concentration for selected supporting electrolytes; on the anodic side this effect is also present, but not that specific. The performance of BDD thin films on electroanalysis was tested with 2-aminobiphenyl as model compound. Using differential pulse voltammetry for its determination. Peak height and sensitivity increases with increasing concentration of boron in BDD thin film. 5
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