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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Zinkem navozená aktivace prsních buněčných linií a zapojení Map kinázy / Zinc induced activation of breast cancer cell lines and the involvement of Map kinase

Králová, Jarmila January 2012 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Jarmila Králová Supervisor: Dr. Kathryn Taylor, Ph.D., PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Zinc induced activation of breast cancer cell lines and the involvement of MAP kinase The aim of this work was to investigate the effect of zinc on various signalling pathways in breast carcinoma cell lines MCF7 and TamR cells. The differences between signalling pathways in MCF7 cell line and TamR cells were evaluated with a special focus on a role of MAP kinase, which activation is believed to be linked with malignant diseases. An effect of zinc on various cellular kinases in 0, 2, 5, 10, 15 and 20 minute of zinc treatment was analyzed in MCF7 cells transfected by wild and mutant type of ZIP 7, TamR cells and TamR cells pre-treated with MAP kinase inhibitor (PD) using the methods of western blotting and fluorescent microscopy. We show here the dependence of activation of pMAP kinase and other important oncogenic kinases (such as Lyn, Src and STAT3) on zinc release into cytoplasm. According to our results, MAP kinase is activated very upstream and it can stimulate many important protein kinases as Src Y418 , STAT3 S727 and Lyn Y396 in tamoxifen-resistant breast cancer...
22

Vliv dlouhodobého hnojení travního porostu na obsah rizikových prvků v půdě / Effect of long-term fertilizer application on content of risk elements in grassland soil

Jungová, Michaela January 2017 (has links)
The long-term Steinach Grassland Experiment is probably one of the oldest still-running fertilised grass experiments in continental Europe. The experiment was established on an alluvial meadow Alopecurus pratensis in southeastern Germany in 1933. The meadow was divided into 75 plots and fertilised with both mineral and organic fertilisers of differing compositions and amounts. The aim of this study was to provide more detailed information about the effects of long-term fertilisation by natrium (N), phosphorus (P) and potassium (K) on the contents of risk elements in soil. The effects of long-term fertilisation were investigated in the extracts of a) plant-available elements (extraction of CaCl2), b) easily mobilised elements (extraction of EDTA), c) potentially mobilisable elements (extraction of HNO3), the total concentration of elements (extraction of Aqua regia). Concentrations of risk elements As, Cr, Cu, Fe, Mn, Ni and Zn in the soil profile has increased substantially due to the phosphorus fertilisation; however, the limits for total trace elements concentration as set by the Czech legislation have been exceeded only twice, namely in the case of As and Cd. The total concentration of As (AsT) has been exceeded only once, on the plot fertilised only by nitrogen. The assumption is that that the increased level of AsT fraction in soil was probably caused in the past by fertilising with Thomas slag which is known to contain elevated concentrations of As. However, fertilising with the phosphorus-containing fertilisers has had the opposite effect on concentrations of Mn, Ni and Zn that are easily available to plants; concentrations of these elements in the soil extraction were substantially higher. In spite of the overall concentrations of Cd being lower than the Czech legislative standards, the results on several plots fertilised by mineral and organic fertilisers containing N, P and K showed higher concentrations of Cd and in one case reached the limit value. Plots fertilised by mineral fertilisers N160P44K174 (NH4)2SO4 recorded higher Cr concentrations. In overview, it could be stated that under various types of fertilising no substantial effects of long-term fertiliser applications on a higher content of risk elements in soil has been detected. Only two plots have exceeded the limits set by Notice 13/1994 Sb., in one case it was a total concentration of As and in another one that of Cd.
23

Obsah zinku, mědi a jódu v mléce krav

JAKEŠOVÁ, Jitka January 2017 (has links)
Milk and dairy products are one of the most important sources of essential trace elements in human nutrition. My thesis provides informations about the content of zinc, copper and iodine in milk during the lactation and also includes the impact of other factors on the content of elements. The experiment includes dairy cattle breedings from Hořepník and Chyšná which are located in the region Vysočina. Another breeding is from Haklovy Dvory. It is located in southern Bohemia. Milk samples were taken in the relation to performance monitoring. During the period 25 to 132 days of lactation were taken 90 samples of milk from the Hořepník breeding. From breeding Chyšná were taken 78 samples of milk in the period of 11 - 89 days of lactation and from breeding Haklovy Dvory 81 samples of milk during the period 23 to 244 days of lactation. Copper and zinc content in milk was determined by atomic absorption spektrometry. The iodine content in the milk was set by spectrometry after incineration alkaline by Sandell-Kolthoff. The average zinc content in the milk was 3.59 ? 1.15 mg-l-1. The average copper content in milk was 0.14 ? 0.12 mg-l-1and the average content of iodine in the milk was 0.18 ? 0 06 mg-l-1. The greatest variability in milk was proved to copper (V = 82,65%), the lowest zinc (V = 32,05%). The greatest effect of the duration of lactation was observed in breeding Hořepník (Zn: rxy = -0,430, Cu: rxy = -0,425, I: rxy = 0,326). The influence of the duration of lactation was insignifant in the breeding Haklovy Dvory and Chyšná. Cow's milk, according to our results, supply the iodine accounts from 19,2% for men and 52,4% for women. The milk supply the zinc accounts from 5,2 % for men and 7,2 % for women, and copper from 2,5% for both sex.
24

Vlastnosti a in vitro degradace kovových biodegradabilních materiálů / Properties and in vitro Degradation of Metalic Biodegradable Materials

Ročňáková, Ivana January 2017 (has links)
Biodegradable metallic materials for medical applications have received considerable attention in recent years. The main reason is that they provide high potential for fabrication of temporal orthopedic implants such as bone fixation devices. Magnesium is an excellent candidate for fabrication of biodegradable implants due to its biocompatibility, mechanical properties similar to human bone and relevance for biological body functions. The fast degradation rate of magnesium and its biodegradable alloys in physiological environment limits its clinical application. Another attractive material in the field of biodegradable materials is zinc, which is among the essential elements in human body. Zinc exhibits an excellent corrosion resistance, and inferior biocompatibility compared to with magnesium. Hence, surface modification to form a hard, dense/porous, biocompatible and corrosion resistant modified layer has become an interesting topic in magnesium base biomaterials. Since hydroxyapatite is well tolerated by living organisms and in addition, improves the bone growth, it appears to be excellent candidate for such coatings on surface of biodegradable materials (e.g. Mg, Zn). This thesis is focused on comparison of corrosion behavior of pure non ferrous metals (Mg, Zn) and metals coated with hydroxyapatite, in simulated body fluids. The present approach is the use of modified atmospheric plasma spray technology to produce the hydroxyapatite coatings – suspension spraying. Composition and structure of the coatings and corrosion products were studied by light microscopy, scanning electron microscopy equipped with energy dispersive microanalyzer and X-ray diffraction. Corrosion of Mg and Zn samples was monitored by weight loss and determined by X ray and micro-tomography. The application of the HA coating resulted in decrease of corrosion rate of pure Mg. The corrosion rate of coated Mg samples was lower by 27,3 % in comparison with the corrosion rate of pure non coated Mg. Corrosion degradation of uncoated and coated Zn samples was minimal. The aplication of HA on the non ferrous surface appears to be a very promising method to improve corrosion and biological properties of these biodegradable materials.
25

Příprava ternárních ZnxTiyOz nanostruktur metodou sol-gel a jejich aplikace v techologii solárních článků a ve fotonice / Sol-gel synthesis of ternary ZnxTiyOz nanostructures for applications in solar cell technologies and photonics

Mrázek, Jan January 2011 (has links)
The presented study deals with the sol-gel synthesis of nanocrystalline ternary phases of the general formula ZnxTiyOz, their characterization and potential application in photonics. Achieved results brings new fundamental knowledge about the processes leading to the formation of ZnxTiyOz nanocrystals from amorphous xerogels and gives novel information about structural and opto-electrical properties of prepared materials. Based on the presented results, most of all up-to-date reported ZnxTiyOz compounds with tailored nanocrystalline size and structure can be prepared as powders or thin films. Two sol-gel approaches based on the cluster process and direct heteronucleation were employed to prepare initial sol. Sols were optionally doped by Eu3+ ions to evaluate the effects of rare earth element to crystallization properties of formed compounds. In the first part of our study crystallization properties and structural evolution of thermally treated xerogels were analyzed. As a result a versatile method allowing the preparation of inverse spinel Zn2TiO4, cubic defect spinel ZnTiO3 and rhombohedral ZnTiO3 with tailored nanocrystal sizes was established. Initial composition and thermal annealing allow us to prepare selected ternary phase with tailored nanocrystal size ranging from tens of nanometers up to...
26

Screening nových chelátorů mikrobiogenních kovů / Screening of novel chelators of microbiogenic metals

Catapano, Maria Carmen January 2020 (has links)
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...
27

Vliv skladování na obsah vybraných nutrientů v křepelčích vejcích

Piskořová, Daniela January 2018 (has links)
The aim of this master’s thesis was to determine the total contents of selected nutrients (magnesium, copper, calcium, zinc and iron) in quail eggs during the time of their storage. The contents of elements were measured in fresh eggs and then after first, second, third, eighth, fifteenth, twenty – ninth, forty – third and fifty – seventh day of storage. Theoretical part is focused on the production and importance of eggs, their creation and chemical composition. Additionally, this part deals with the more detailed characteristics of aforementioned elements and with their relationship to human nutrition. The practical part includes the results of measured contents of elements in whole egg, yolk and egg white. The analysis was carried out using atomic absorption spectrometry. The results show that the time of storing has no effect on the contents of selected elements in quail eggs.
28

Vliv skladování na obsah vybraných nutrientů v slepičích vejcích

Slováček, Robin January 2018 (has links)
The aim of this master´s thesis was to determinate selected nutrients in hen eggs depending on the time of their storage. The content of nutrients in hen albumen, hen yolk and hen melange was measured in fresh eggs ang in storaged eggs after one, two, eight, fiveteen, twenty nine, forty three and fifty seven days. Teoretical part of thesis is focused on chemical composition of hen egg, breeding, history, storage and consumption. Another part of thesis deals with selected nutrients, specifically by magnesium, copper, calcium, zinc and iron. In practical part the results are presented. The content of these elements was determined with using atomic absorption spectometry. The results show that the storage time did not have an effect on the contents of the selected elements in the eggs. Formula clause:hen egg, magnesium, copper, calcium, iron, zinc, atomic absorption spectrometry
29

Interakce mezi minerálnimi prvky v dietě brojlerů a jeji vliv na vlastnosti svaloviny

Prokop, Jakub January 2017 (has links)
Diploma thesis deals with influence of mineral elements level in the diet of broiler chickens. Primary observe their importance in meat production with high nutritional and sensory quality. In experiment we tried to modulate the performance of chickens by changing the level of zinc (24 g, 204 g), calcium (2 g, 15 g) and magnesium (1,5 g, 4,5 g) and test the influence on sensory attributes of breast and tight meat. After slaughter in the age of 36 days the meat was processed and frozen stored. In sensory analysis (after heat processing) color, texture, odour, presence of strange odour, tenderness, juiciness, taste and presence of strange taste was judge. We discovered that different level of zinc has negative influence on the odour of tight meat (85,50+-2,108; 77,03+-3,333). Higher level of calcium and magnesium for the breast meat had positive influence on the color (83,53+-2,663; 88,50+-1,731) and negative influence on odour (86,10+-2,428; 76,66+-3,341), chewiness (77,73+-4,157; 63,33+-4,607) and taste (71,83+-4,325; 57,75+-4,532). In the end we can conclude that addition of different levels on mineral elements can influence organoleptic properties of meat and its acceptance for the consumer. It is necessary to do more experiments in this subject in the future.
30

Vliv selenu, zinku, vitamínu C a E na potlačení tepelného stresu u kanců

Půlpánová, Barbora January 2017 (has links)
The aim of the study was influence of the complex of two elements (zinc, selenium) and two vitamins (vit C, vit E) on the organism of pigs under heat stress. Twenty boars of the Duroc breed were included in the experiment. The boars were approximately the same age and weight, housed individually. They were divided into 2 groups. The control group (n = 6) was fed only to a basic feed mixture containing 0.02 mg Se; 21.5 mg Zn; 9.9 mg of vitamin E and 16.0 mg of vitamin C. In addition, 0.5 mg of selenomethionine, 70 mg of alpha-tocopherol, 70 mg of zinc oxide and 350 mg of ascorbic acid were added to the diet (n = 6). The experiment took place from June to September at the insemination station in Velké Meziříčí. The control group showed a slight increase in ejaculate volume (by 19 %), which is common in the summer months. At the same time, the sperm concentration was unstable, it increased by 15 % in August, but fell below the baseline by 3.5 % in September. Motility was around 69 % during the experiment. Statistically significant was an increase (by 15 %) of morphologically abnormal sperm in the ejaculate (P < 0.05). The experimental group had higher ejaculate from the beginning. However, the volume curve was almost identical to the experimental group. The sperm concentration increased by 23 % in the trial group after adding antioxidants. During the experiment the concentration only slightly decreased. Motility in the experimental group averaged 70 % and did not change significantly during the experiment. Even in the control group there was a statistically significant increase in morphologically abnormal sperm (by 12.3 %), (P <0.05). From the results it can be concluded that the increased amount of selected antioxidants did not have a demonstrable effect on the improvement of the ejaculate quality, but it can be assumed that this quantity has ensured the stability of the seed parameters.

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