In the thesis the author observes a progression of volume of hydroxycinnamic acids in grapes of a grapevine. Ten brands of grapevine originating from Mikulov vine subregion village Lednice were selected for the experiment that proceeded in September and October 2016. The development of hydroxycinnamic acids during a process of maturing was observed with four out of these brands as well as relation of their volume to basic analytic variables of a must. The remaining six vine brands were compared for volume of hydroxycinnamic acids as an attribute of a given brand in two takings. Literary part of the thesis approaches matters of fenolic substances with focus on hydroxycinnamic acids, their structure and forms. This part also contains a brief characteristics of the ten types of grapevine selected for the experiment.

The thesis deals with monitoring of ascorbic acid and other substances in selected fruit drinks. The theoretical part begins with a summary of knowledge about the occurrence and importance of ascorbic acid and their physiological effects. Furthermore, the content of vitamin C in individual fruits is compared. The following part deals with the division of soft drinks and raw materials, used for the production of soft fruit drinks. Part of the thesis is focused on the technology of fruit juice production obtained by direct pressing of fruit material and technology of fruit drinks production from fruit concentrates. The practical part is focused on determination of vitamin C concentration as well as vitamins of group B (B1, B2, B3, B5, B6) and organic acids (citramic acid, citric acid, malic acid, pyruvic acid and succinic acid) in samples of direct fruit juices and juice from concentrate. Mass spectrometer-coupled high-performance liquid chromatography (HPLC-MS) was used to detect vitamin C and other substances.

The thesis „Determination of Vitamin C in Food Supplements“ is concerned with the comparison of vitamin C concentration levels in effervescent tablets and bulk mixtures stored in tubes with different closures (molecular sieve, silica gel, and the solitary closure) after a certain storage time. Two batches of dietary supplements for adult and juvenile populations were analyzed (Revital vitamin C 500 mg and MaxiVita Kids Multivitamin containing 40 mg of vitamin C). Measurements were taken 6 months after production, then after 10 months and after 14 months of storage. The content of vitamin C was determined by the titration method and high performance liquid chromatography (HPLC). The types of closures, batches of products, individual measurements and methods of vitamin C determination were compared. Based on the measurements, it was found that after some time the concentration of vitamin C decreased significantly. Nevertheless, the type of closure did not significantly affect the vitamin C level in effervescent tablets and bulk mixtures.

Cancer is one of the most challenging problems the modern medicine is facing today. An increasing incidence and a great variability of tumor cells are the main reasons those drive the research to develop better diagnostics and therapeutic protocols. Histone deacetylase inhibitors, a group of epigenetic chemotherapeutics, are able to improve the performance of currently used anticancer agents. Vaplroic acid that is commonly used as antiepileptic drug exhibits a remarkable anticancer activity by itself as well as it is capable of therapy potentiation based on other therapeutic agents. Its effect to inhibit growth of tumor cells and induce apoptotic cell death seems to be even greater under hypoxic conditions (<1% O2). This study is focused on effect of valproic acid on neuroblastoma cell lines in vitro under normoxic and hypoxic conditions. We observed significantly greater efficacy of valproic acid in hypoxia compared to normoxia. The mechanism of induction of apoptotic cell death is based on disruption of the balance between pro- and antiapoptoic proteins. Intrinsic apoptotic pathway is probably initiated by the action of 19 kDa variant of proapoptotic protein Bax on mitochondrial membrane. Moreover, we examined the efficiency of a combined treatment of neuroblastoma cells with valproic acid and...

A new method for determining the viscoelastic properties of materials was introduced and investigated. Results of three groups of samples obtained using one particle microrheology method, DLS microrheology method and classical rheology method were compared to be sure of correctness of measurements. As a model system were chosen mixtures of glycerol of different viscosities. In case of samples containing glycerol, results were also compared with tabulated values. Hyaluronan of various molecular weights was used as a biopolymer and polystyrene particles were used for microrheology. It was confirmed, that viscosity values of biopolymer samples obtaining by each method are comparable.

The objective of the present work is the study of the electrochemical behaviour of two diagnostic tumor markers of great importance, vanillylmandelic acid (VMA) and homovanillic acid (HVA), on carbon-based electrodes by using cyclic and differential pulse voltammetry. A comparison was made among non-modified glassy carbon electrode (GCE) and GCE modified by multi-walled carbon nanotubes, Nafion (Nafion/GCE) and poly(neutral red) (PNR/GCE), and further boron doped diamond (BDD) electrode which was activated by anodic polarization (Eakt = +2,4 V, t = 30 s) or by polishing on alumina slurry. Significant differences in the voltammetric responses of VMA and HVA were found, not only among utilized electrode materials which also influenced the way of controlling the oxidation process, but also they depend on the pH value of aqueous media in which these acids occurred. An acidic environment is the most suitable for their determination. Calibration dependences were measured in 0.1 mol∙l−1 phosphate buffer pH 3.0 which was chosen as an optimal supporting electrolyte for differential pulse voltammetric determination. Achieved detection limits were 0.6, 0.9, 0.8 and 1.2 μmol∙l−1 for HVA and 0.4, 1.5, 2.4 and 1.1 μmol∙l−1 for VMA at BDD electrode, non-modified GCE, Nafion/GCE and PNR/GCE, respectively. Limits...

In this master s thesis, electrochemical determination of homovanillic acid (HVA) andˈ vanillylmandelic acid (VMA) was performed on carbon paste electrode. The purpose of this thesis was finding out optimal conditions for determination of these analytes by ndifferential pulse voltammetry (DPV) and high pressure liquid chromatography with a carbon paste electrode as an electrochemical detector (HPLC-ED). The electrochemical behavior of the compounds depends mainly on pH of the solution; the best results are obtained in acidic medium. The limits of detection for DPV method were for HVA 0,38 μmol·dm-3 and for VMA 0,25 μmol·dm-3 . The limits of detection for HPLC-ED were for HVA 0,7 μmol·dm-3 and for VMA 0,2 μmol·dm-3 . Developed method was successfully used for the determination of homovanillic and vanillylmandelic acid in urine samples. With HPLC - ED the limits of detection 0,8 μmol·dm-3 (HVA) and 0,5 μmol·dm-3 (VMA) were achieved. Key words: Homovanillic acid, vanillylmandelic acid, carbon paste electrode, DPV, HPLC

The aim of this work was to synthesise water-soluble QDs using different precursors and stabilizers and to determine the toxicity of the synthesized QDs by in vivo imaging. Experiments were performed on water-soluble QDs (MPA-CdTe, MPA-CdTe/ZnS, MSA-CdTe, MSA-CdTe/ZnS, GSH-CdTe, GSH-CdTe/ZnS, TGA-CdTe, TGA-CdTe/ZnS, GSH-ZnSe and GSH-ZnSe/ZnS ) and toxicity was measured. Synthesized QDs were characterized by high intensity (fluorescence spectroscopy), FWHM and zeta potential (ZS Zetasizer) were selected due to their suitability for this task. The toxicity of QDs was determined by the MTT assay on the cell line HEK 293. The experiments show that a core/shell structure is less toxic than a core structure. The results indicate that the toxicity of our synthesized QDs is the lowest for MPA-CdTe (core structure) and MPA-CdTe/ZnS (core/shell structure).

The aim of this work was to synthesise water-soluble QDs using different precursors and stabilizers and to determine the toxicity of the synthesized QDs by in vivo imaging. Experiments were performed on water-soluble QDs (MPA-CdTe, MPA-CdTe/ZnS, MSA-CdTe, MSA-CdTe/ZnS, GSH-CdTe, GSH-CdTe/ZnS, TGA-CdTe, TGA-CdTe/ZnS, GSH-ZnSe and GSH-ZnSe/ZnS ) and toxicity was measured. Synthesized QDs were characterized by high intensity (fluorescence spectroscopy), FWHM and zeta potential (ZS Zetasizer) were selected due to their suitability for this task. The toxicity of QDs was determined by the MTT assay on the cell line HEK 293. The experiments show that a core/shell structure is less toxic than a core structure. The results indicate that the toxicity of our synthesized QDs is the lowest for MPA-CdTe (core structure) and MPA-CdTe/ZnS (core/shell structure).

The thesis deals with beneficial omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and their beneficial effects on health. Characteristics, properties and appearance of omega-3 fatty acids may explain some of the mechanisms of their effects on human health manifested not only in the treatment and mitigation of some non-infectious diseases of mass occurrence, but especially in the area of preventive action. Theoretic information used in the first part of this work was obtained from scientific and professional publications and periodicals searched in domestic and international databases of scientific and specialist literature. The part of data collection and analysis compares the intake of omega-3 acids in the form of fish dishes prepared for children in the first half of elementary school, aged 7 to 10 years, in randomly selected school canteens or contracted catering in the European Union with the recommendations of Decree 107/2005 Sb. Ministry of Education.