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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...

The diploma thesis deals with lignitic humic acids. Bibliographic search can be divided into three parts. The aim of the first part is characterization of humic substances, presence, composition, structure and exploitation especially of humic acids. The second part describes a division of heterogeneous mixture of humic acids into closed fractions with more specific properties. The final part is a study of solubility of humic acids. The experimental part of the diploma thesis is structured similarly. In this work, a gradual fractionation with pH is used. Obtained fractions were characterized by UV/VIS and FT-IR spectroscopy. We assessed the portion of ash and carboxyl groups have been identified. Subsequently, all fractions extracted by gradual fractionation as well as some soluble fractions obtained by direct fractionation have been analyzed in view of solubility and their behaviour in water environment. Both used methods were compared.

This thesis deals with the development of high performance liquid chromatography method (HPLC) for the determination of propionic acid in bakery products. This work is resulting from the requirements and conditions of Czech Agriculture and Food Inspection Authority (CAFIA) laboratory in Brno. The theoretical part of the thesis describes properties, production, metabolism, toxicity and preservative effect of propionic acid. Furthermore it is treating about HPLC, validation of some analytical method and methods of propionic acid determination. Experimental part is focused on the propionic acid determination in the major part of available products with this preservative on the Czech market. Propionic acid was extracted from the sample with water, filtered and the filtrate was analyzed directly by HPLC. Separation was performed on a XBridge C18 column (3 x 150 mm, 3,5 µm) with a mobile phase of phosphate buffer (pH adjusted to 2,8) and UV detection at 210 nm. Used method of propionic acid isolation was compared with repeated extraction method, extraction in the mobile phase solution and steam destilation both in commercial samples and in laboratory baked breads with known addition of propionic acid. HPLC with water extraction technique was evaluated as a suitable method for propionic acid determination in bakery products.

This work deals with the optimization of the method for determination of conjugated linoleic acid (CLA) using gas chromatography. The summary about formation and occurrence of CLA in animal materials, its biological effects in human organism and methods suitable for its determination is introduced in the theoretical part of this study. The experimental part verify, if the gas chromatography is applicable method for assesment of CLA in selected biological matrices. The chosen method was introduced and verified at FCH of Brno university of technology. At the end the applicability of this method to CLA determination is discussed here.

This diploma thesis was focused on basic physicochemical properties of caffeine and investigation of the interaction between the polysaccharide sodium hyaluronan (HA), pectin (PEC) or lignohumate (HUM) and the alkaloid caffeine (CAF). The reason why this thesis was focused on study of aqueous solutions of hyaluronan or pectin with caffeine is that the presence of polysaccharide- caffeine complex could be beneficial for slowing the absorption of caffeine. In the theoretical part of the diploma thesis there is described a group of alkaloids, which caffeine belongs to and also polysaccharides hyaluronic acid and pectin. The most attention has been paid to caffeine, its properties and effects on the human organism. This diploma thesis also deals with non-alcoholic beverages with caffeine, 4-methylimidazole, and phosphoric acid. The last chapter of the theoretical part is dedicated to fluorescence spectroscopy. In the experimental part of this work I deal with the basic properties of caffeine and interaction between the caffeine and selected polysaccharides or lignohumate. At first, the chemical and physical properties of caffeine were determined. Based on these results the interaction of caffeine and hyaluronan or pectin was studied by using the fluorescence and absorbance. The HA of molecular weight of 1,7 MDa and pectin from citrus fruits were chosen for the study of the interaction with the caffeine. These two substances were mixed with the caffeine of concentration contained in Coca-Cola. The results of interaction that would lead to the influence of the emission or absorption properties of caffeine, were not proved. As a part of the work there was determined how pectin behaves in strongly acidic solution and then there was monitored the pH, conductivity and solubility of caffeine in water by using thermogravimetry and visual experiments. The obtained results of the interaction of hyaluronan-caffeine, pectin caffeine or caffeine-lignohumate can be used for description of the behavior of caffeine in the presence of selected polysaccharides and natural organic substance.

Všeobecne, cieľom tejto diplomovej práce bola príprava a charakterizácia sieťovaných hyaluronových mikrovláken, ktoré by boli stabilné vo vodnom prostredí s vhodnými mechanickými vlastnosťami. Vlákna pripravené technikou zvlákňovania z roztoku boli sieťované pomocou roztoku so sieťovacím činidlom 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimidom alebo roztoku s dvoma sieťovacími činidlami 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimidom a N-hydroxysuccinimidom, vedúcim k amidácii a tvorbe esterových väzieb. Charakterizácia pripravených vzoriek je hlavným cieľom experimentálnej časti práce. Charakteristiky botnání boli vykonané na určenie stability vláken v troch rôznych roztokoch (s pH 7.4, 3 a 11). Na určenie termickej stability bola využitá termogravimetrická analýza a na stanovenie esterifikácie a amidácie bola použitá infračervená spektroskopia s Fourierovou transformáciou. Mechanické vlastnosti vláken boli študované pomocou testovania závislosti stress-strain. Ďalej boli testované reologické vlastnosti ako aj mikroštruktúra a povrch vláken pomocou skenovacieho elektrónového mikroskopu. Vlákna pred chemickým sieťovaním vykazovali nižšiu stabilitu vo všetkých troch roztokoch, termálna stabilita bola taktiež nižšia ako stabilita zosieťovaných vláken. Pre vlákna chemicky nemodifikované so sieťujúcim činidlom, sa objavil iba jeden typ píku pre esterifikáciu. Infračervené spektrum chemicky zosieťovaných vláken ukázalo prítomnosť dvoch píkov pre esterifikáciu, čo je prejavom efektivity sieťovacieho činidla. Amidácia bola tiež výraznejšia pri zosieťovaných vláknach, špeciálne pre vlákna sieťované dlhú dobu a v roztoku s vyššou koncentráciou sieťujúceho činidla. Kvôli nerovnomerným vláknam, mechanické vlastnosti nevykazovali žiadnu závislosť na sieťovaní. Štúdium reológie ukázalo, že viskozita vlákna rozpusteného vo vode je menej závislá na šmykovej rýchlosti ako prášok hyaluronanu sodného rozpusteného vo vode. Napriek mnohým rôznym metódam charakterizácie vláken, ktoré boli použité v tejto práci, je stále veľa možností pre lepšiu charakterizáciu a bližšie pochopenie tohto biopolymérneho materiálu.

Works created within the engineering studies in collaboration with IDEAL-Trade service discusses the influence of pickling acids on steel material and on the same material with powder coated . Based on the literature study and consultations with employees of the company were designed each experiment, investigators removal and acid corrosion attack , another verify adhesiveness powder coatings for various periods of exposure pickled material. Experiments and tests were carried out in companies ECOS , ITS and faculty FSI.

This master thesis focuses on the effect of cultivation parameters on hyaluronic acid synthesis during its biotechnological production. The cultivation parameters were temperature of the cultivation, aeration, agitation, carbon source and addition of phosphatidylcholine. Changes in molecular weight and yield of hyaluronic acid, growth of biomass and medium viscosity were observed. From the obtained data we learned, that the specific growth rate greatly impacts final characteristics of hyaluronic acid. Under suboptimal temperatures a high molecular weight polymer was synthesised along with comparable yields from the control cultivation. High temperatures (40 °C) caused a dip in molecular weight. The next cultivation parameters were aeration and agitation. The highest molecular weights were obtained in cultivations with high agitation rates and intensive aeration, specifically 1 vvm/800 rpm and 2 vvm/800 rpm. Agitation had a bigger influence on molecular weight than aeration. When the carbon source was changed from sucrose to glucose, the lowest molecular weight and yield were obtained. Addition of phosphatidylcholine with concentration 160 mg/l had a positive effect on the cultivation, where the molecular weight grew and biomass growth was higher.