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Characterization of low-molecular-mass synthetic markers of isoelectric points by capillary zone electrophoresis and capillary isoelectric focusing
Brandejsová, Martina ; Kašička, Václav (advisor) ; Kubíčková, Anna (referee)
High-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), have been applied to physico-chemical characterization of new synthetic low-molecular mass markers of isoelectric points. Amphoteric compounds on the basis of aminomethylnitrophenols, their derivatives and other structurally related substances were analyzed by CZE in a series of background electrolytes in a wide pH range, 1.86 - 11.18. From the measured pH dependencies of effective electrophoretic mobilities of analytes (beforehand corrected to reference temperature of 25 řC), their isoelectric points (pI) were determined. In addition, using the non-linear regression analysis of the above dependencies, acid-base dissociation constants (pKa) of ionogenic groups of selected analytes were calculated. Subsequently, the analytes with sharply defined isoelectric points were analyzed by CIEF. CIEF confirmed applicability of these compounds as markers of isoelectric points for calibration of pH gradient in CIEF in the determination of pI of amphoteric compounds, especially peptides and proteins. The determined pKa values of ionogenic groups in particular compounds will be utilized in the development of new pI markers with desired pI values.
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The issue of child soldiers in international law with regard to the African regional regulation
Kubíčková, Anna ; Honusková, Věra (advisor) ; Bayerová, Monika (referee)
The main purpose of this thesis was to give a general overview of the problem of child soldiers and their protection among international law conventions and among regional law agreements with the focus on the African continent. The use of child soldiers in armed conflict is qualified as one of the worst forms of child labour.The majority of child soldiers are active in Africa and, to a lesser extent, in the Middle East and Asia. Besides introduction and conclusion, the study consists of five chapters. The first chapter describes the protection of child soldiers on the international level. Therefore it is focused on individual conventions, especially on Geneva Conventions, Additional Protocols to the Geneva Conventions, the Convention on the Rights of the Child, the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict, the Optional Protocol to the Convention on the Rights of the Child on a Communications Procedure, but as well on the International Labour Convention No. 182 or the Rome Statute. The soft law represents Paris principles. Discussed is particularly the question of the age limit for child participation in armed conflict. The second chapter is concerned with the international control mechanisms, resulting from the above-mentioned...
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Development of Electrochemical Thin-layer Degradation Cell for Oxidation Stress Testing of Active Pharmaceutical Ingredients
Šefčík, Martin ; Kubíčková, Anna (advisor) ; Coufal, Pavel (referee)
In this thesis, the oxidation conditions in a new electrochemical "thin-layer" flow-through cell for the study of the oxidative degradation of active pharmaceutical ingredients were optimized. In this field, it is an innovative approach to studying the oxidation properties of substances. The cell was manufactured using 3D printing technology. Oxidation was carried out in a two-electrode arrangement with a working boron-doped diamond electrode (BDDE) and an auxiliary stainless steel electrode. Optimization of conditions was performed using salicylic acid as a model active pharmaceutical ingredient. The electrochemical approach was used to degrade this active pharmaceutical ingredient by the required approximately 20% of the original amount in only 2.3 min. Thus, the degradation time was significantly reduced compared to the oxidative stability stress tests of active pharmaceutical ingredients commonly used today. Two major degradation products were observed, namely gentisic acid and 2,3-dihydroxybenzoic acid. The degradation products obtained by electrochemical oxidation and chemical oxidation using hydrogen peroxide are identical.
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Development of electrochemical flow-through detectors based on carbon nanotubes
Pavlíčková, Eva ; Dejmková, Hana (advisor) ; Kubíčková, Anna (referee)
This work deals with the development of a flow through detection cell using carbon nanotubes deposited on a membrane as the working electrode. 3D printing was used to obtain prototypes of the detection cells. Uric acid and dopamine were used as analytes to verify the functionality of the cells. Three prototype cells were prepared during the work, differing in the location of the reference electrode and in the method of inserting the working electrode. Four cells with different internal dimensions are compared in this work, the best cell is the one with a length of 3 mm and a diameter of 3 mm. This membrane has to be lined with a non-woven fabric and another membrane for lower deformation of the nanotube membrane. The optimum conditions for the determination of the dopamine-urea acid mixture are: mobile phase 90 % phosphate acetate buffer pH 6 and 10 % methanol, input potential 0,5 V and flow rate 0,5 ml/min. The concentration of the nanotubes on the membrane is 0,05 mg/ml, higher concentration does not improve the degree of conversion, which is 0,6. Different types of nanotubes are also compared in this work. The short and wide nanotubes appear to be the best ones, which have the best repeatability and are closest to the theoretical charge exchange value of the measured substances.
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Impacts of family background on education of students in primary schools
Melicharová, Klára ; Kubíčková, Anna (advisor) ; Němec, Zbyněk (referee)
The topic of this bachelor thesis is the impacts of family background on pupils' education in primary schools. The thesis aims to examine the direct effects of family background on the behavior and education of pupils in primary schools. The theoretical part explores the topic of family background, defines the consequences of negative experiences in close relationships, and then discusses the three levels of mental health support and well-being support for pupils. The research part of the thesis is conducted through ten online interviews with primary school teachers. The collected data are then analyzed and summarised into tables, which contain information about the pupil's family situation and the impact of family background on the pupil's behavior and education. The results based on the data are summarised using graphs. The research found that family background and negative childhood experience have had a negative impact on the pupil's behavior and education in eight cases and on the pupil's behavior or education in two cases. The degree of impact on a given pupil varies according to the severity of the family situation. The degree of impact on a given pupil varies due to the severity of the family situation. KEYWORDS family background, negative childhood experiences, Syndrome CAN, mental health...
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Supporting the wellbeing of pupils with special educational needs at the upper primary school
Kutnarová, Františka ; Kubíčková, Anna (advisor) ; Felcmanová, Lenka (referee)
The bachelor's thesis entitled "Supporting the wellbeing of pupils with special educational needs at the lower secondary school" addresses the issue of wellbeing among students with special educational needs in the lower secondary stage of elementary schools, with a focus on social and emotional aspects. The theoretical part of the thesis defines the concept of wellbeing, its factors, and its impact on overall quality of life. It further examines the classroom climate as an environment that influences students' wellbeing. The role of the class teacher in supporting the wellbeing of students with special educational needs is also described, with emphasis on the specificities of working with these students and supporting their individual needs. The research results will provide a comprehensive understanding of the work of class teachers and their efforts to create a supportive environment for the wellbeing of students with special educational needs, as well as the entire class community. The findings can be used to formulate recommendations for class teachers, educational institutions, and other relevant stakeholders to better support the social and emotional aspects of wellbeing among students with special educational needs in the lower secondary stage of elementary schools. The outputs should be...
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Determination of inorganic corrosion inhibitors by ion chromatography
Kapiasová, Anna ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
Corrosion inhibitors are substances that prevent the internal surface of the cooling system from corrosion. Inorganic corrosion inhibitors contain inorganic anions that passivate the surface, thereby preventing the diffusion of oxygen into the system and protecting the surface from oxidation. This study is aimed at the development and validation of a method for the determination of inorganic corrosion inhibitors (specifically chlorides, nitrites, nitrates, hydrogen phosphates, sulfates and molybdates) by ion chromatography. The optimal separation of anions was achieved with a mobile phase consist of 3.3 mM sodium carbonate and 3.3 mM sodium bicarbonate (pH= 10.1) at 45 řC using the column Metrosep A Supp 7 (250 × 4.0 mm with particle size of 5 µm) (Metrohm, Switzerland). Under these conditions the analysis took 48 minutes. After validation, the method was used to determine corrosion inhibitors in real coolant samples. The peaks of the individual anions contained in the coolants were verified by spiking with standards of anions. The anion concentrations were determined from the areas of these peaks using the calibration curves. Key words ion chromatography, engine coolants, corrosion inhibitors, inorganic ions
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Determination of glutathion in plant samples using capillary electrophoresis
Skála, Michael ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This work is based on a previously published method for determination of both glutathione forms by capillary zone electrophoresis equipped with UV spectrometric detector. Theoretical part described biological and biochemical functions of glutathione as a molecule. It mentioned historically used methods for glutathione determination, their accuracy, precision and reliability and focused on electrophoretic methods, especially capillary zone electrophoresis. Basic principles of capillary zone electrophoresis were described, followed by an overview of approaches to treatment of different types of samples, with special focus on plant samples. At the end, method this work was based on was described. The experimental part describes the development and optimization of this method. Firstly, optimum chemical composition and ionic strength of background electrolyte were determined - two electrolytes were compared, with NaCl and without NaCl - no significant differences were observed, so NaCl was excluded from BGE. Next, optimum concentration of hexadimethrine bromide was determined. The effect of HDB concentration on electroosmotic flow was investigated. Calibration curve for different concentrations of analytes in water was constructed and repeatability, LOD and LOQ of the method were determined....
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Comparison of different tandem mass detection scans in the analysis of cannabidiol
Tichá, Tereza ; Kozlík, Petr (advisor) ; Kubíčková, Anna (referee)
The aim of this bachelor thesis was to compare different tandem mass spectrometer scans in order to develop an LC-MS/MS method suitable for the determination of cannabidiol in rat serum. In this bachelor thesis the mass spectrometer and high-performance liquid chromatography method were optimized. The optimum parameters were as follows: chromatographic column Acquity UPLC BEH C18 50 × 2,1 mm, 1,7 μm from Waters (Wexford, Ireland). The mobile phase consisted of methanol and water of LC-MS purity. The flow rate of the mobile phase was 0,4 ml/min, the column temperature 40 řC, the temperature in an autosampler 15 řC, the sample injection volume was 1 μl and the analysis time was 7 minutes under gradient elution conditions. The MRM transitions of highest intensity were monitored. For CBD, the MRM transition in positive mode was 315,2 → 193,1 (Q1 = -10 V, CE = -24 V, Q3 = -20 V), for isotopically labeled cannabidiol D3 was chosen 318,4 → 196,0 (Q1 = -10 V, CE = -23 V, Q3 = -20 V). The calibrations in solvent and rat serum were performed in MRM and SIM mode. No calibration was constructed for the SCAN mode due to its low selectivity, which made it able to detect cannabidiol only from concentration of 312,5 ng/ml. The highly selective MRM was able to operate over the entire observed concentration range of...
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