National Repository of Grey Literature 150 records found  beginprevious86 - 95nextend  jump to record: Search took 0.02 seconds. 
Determination of selected elements in potato tubers by atomic absorption spectrometry
Fořtová, Lucie ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The main aim of this bachelor thesis was a determination of the elements K, Mg, Ca, Na, Zn and Fe in the potato tubers and in their boiled solution using the method of flame atomic absorption spectrometry. The chosen samples were late consumer potato tubers of Granada cultivar (boiling type B). It was necessary to optimize working conditions before the sample analysis. The optimal flow rate of acetylene ranged from 2.0 to 2.5 l/min using the flame acetylene-air. The flame acetylene-nitrous oxide was used only for calcium with flow rate 6.0 l/min. The optimal height of a beam above the burner edge was measured in interval 5 to 7 pieces of defined scale mentioned in a manual for spectrometer GBC 933 AA. Using the optimal conditions, the basic characteristics for individual methods of determination were characterized (LOD, LOQ, LDR, sensitivity, repeatability). Limits of quantification were following: 78, 31, 7.0, 8.0, 190 and 71 μg/l for K, Na, Mg, Ca, Fe and Zn, respectively. The optimal conditions were used for the determination of the selected elements in samples. The solutions were prepared from diversely processed potato tubers (whole, whole without skin, chopped without skin, skin) by boiling into deionized water. After the samples had cooled down, the concentrated nitric acid was added...
Biodegradable bones implants based on Fe
Tkáčová, Tereza ; Míka, Martin (referee) ; Sedlaříková, Marie (advisor)
This thesis writes about biodegradable bone implants based on iron. The currently used metal-based implants have disadvantage in an often need of secondary surgery intervention to remove the implant. Therefore, there is a big research of biodegradable bone implants nowadays. In this work, iron-based materials with the addition of zinc and magnesium are being investigated. The produced samples have been immersed in a solution of NaCl and simulated body fluid, SBL. Subsequently there were regularly analysed changes of corrosion potential, pH, conductivity and also weight loss was watched.
Interactions of reduced and oxidized glutathione with copper, iron and zinc
Salanciová, Ingrid ; Karlíčková, Jana (advisor) ; Jenčo, Jaroslav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Ingrid Salanciová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Interactions of reduced and oxidized glutathione with copper, iron and zinc Copper (Cu), iron (Fe) and zinc (Zn) are important trace elements that are necessary for proper function of the body. Excess but also the lack of these metals may lead to pathological conditions. Glutathione is the main antioxidant in the human body so it is expected to protect the organism against concequences of metal excess. Glutathione occurs in the reduced (GSH) and oxidized state as glutathione disulfide (GSSG) in the organism, both states forming an important redox system. On the other hand, glutathione can reduce these metals so that could participate in the formation of free radicals (metal based Fenton reaction). In this diploma thesis, was tested the ability of reduced and oxidized glutathione to interact with Fe, Cu and Zn in various (patho) physiological pH conditions was tested by using in vitro spectrophotometric competitive methods. Interactions include not only the chelation of Cu, Fe and Zn ions, but also their reductive activity toward Cu2+ and Fe3+ cations. Hematoxylin, bathocuproinedisulfonic acid disodium salt, ferrozine...
Screening of novel chelators of microbiogenic metals
Catapano, Maria Carmen ; Mladěnka, Přemysl (advisor) ; Hrdina, Radomír (referee) ; Musiol, Robert (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Maria Carmen Catapano, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Co-supervisor: Assoc. Prof. Laura Mercolini, Ph.D. Title of Doctoral Thesis: Screening of novel chelators of microbiogenic metals Iron, copper and zinc are microbiogenic elements which play crucial roles in a series of physiological processes in human organism. Homeostasis of these transition metals is strictly regulated since, among others: a) free or loosely bound iron or copper can catalyse the production of hydroxyl radical; b) lack of zinc but also of the previously mentioned metals is associated with significant impairments. Hereditary hemochromatosis, transfusion-induced secondary iron overload and Wilson's disease are known as pathological conditions associated with metal overload in the organism. Chelator agents have vital relevance for the treatment of these impairments. There are also numerous diseases with homeostatic imbalances in iron, copper and or zinc: neurodegenerative diseases, cardiovascular diseases, cancer and diabetes mellitus. Different chelating compounds have been examined for the treatment of these impairments. The aim of this doctoral thesis was to perform a screening of metal...
Zinc in food suplements
Sauchanka, Katsiaryna ; Suková, Petra (referee) ; Řezáčová, Veronika (advisor)
The aim of this bachelor thesis was to determine zinc in the dietary supplements by the voltammetric method. The general properties of zinc, its occurrence, toxicity and influence on human health are described in the first part. Next the methods, including a detailed description of the voltammetric analysis, are summarized. The experimental part is focused on the process of optimization of the conditions for zinc voltammetric analysis and the application of the optimised method on real samples.
The study of zinc influence on Portland cement hydration.
Ptáček, Martin ; Janča, Martin (referee) ; Šiler, Pavel (advisor)
The topic of this work is the monitoring of the effect of zinc on the hydration process in Portland mixed cement (specifically with the addition of finely ground granulated blast-furnace slag, high temperature fly ash and fluidized bed combustion filter ash). How much zinc and at what time it remains in the pore solution during hydration. Activation energy of a mixture of cement with zinc in the form of soluble salts (Zn(NO3)2.6H2O and ZnCl2) and insoluble oxide (ZnO) by isothermal calorimetry was also investigated. The XRF method has shown composition during hydration. The zinc retardation effect was investigated by isothermal calorimetry and activation energy was calculated using this method. The XRF and ICP-OES methods were used to measure the zinc content of the pore solution. And the amount of portlandite was monitored by the DTA and XRF method.
Powder metalurgically prepared materials based on Zn and Ca
Morcinek, Tomáš ; Hasoňová, Michaela (referee) ; Doležal, Pavel (advisor)
The topic of this bachelor thesis is a process of preparation and characterization of bulk material from zinc and calcium powder mixture by hot pressing. Materials thus prepared were evaluated in terms of their microstructure and physical-mechanical properties. The influence of calcium content in the material on physical-mechanical properties of the resulting structure was observed. The solution is focused on exploration of the influence of material composition in the process of preparation of bulk material, and description of these processes from the physical-chemical point of view on the structure formation and the resulting properties of the material.
Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
Determination of the potential of process waters for metals recycling
Struňáková, Katarína ; Krystyník, Pavel (advisor) ; Jadrný, Josef (referee)
Incineration of municipal waste in incineration plants leads towards formation of many by- products, such as slug or fly ash. These by-products may contain specific amount of heavy metals. Acidic leaching enables to transfer of some of those metals into liquid phase from which they can be obtained by various methods, i.e. by electrodeposition.. This bachelor thesis is focused on the description of waste incineration process and treatment of solid residual which can potentially be used as a secondary raw material. Incineration plant with a capacity of 96 000 t/year simultaneously treats 27 t of Zinc annually. The economic value of this treated Zinc is about 1 700 000 CZK. In case of 80 % acidic extraction efficiency the price of treated Zinc is still more than 1 400 000 CZK. Thus there is a possibility of Zinc utilization as a secondary raw material.

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