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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.
51

Biodegradabilní kostní implantáty na bázi železa / Biodegradable bones implants based on iron

Hrabovský, Jan January 2021 (has links)
This work deals with a current topic, which are biodegradable bone implants. These implants seem to be a suitable candidate for temporary fixations, with their gradual decomposition. An important parameter is not only the mechanical properties so that the material can withstand the load, but above all the corrosion properties and the degradation process. This work introduces the physiology of bone, trace elements and also describes current trends in the field of implants. The last part is a theoretical introduction to cross-stage processes. The practical part is focused on the preparation of iron-based samples with various dopants, subsequent annealing and analysis.
52

Zastoupení vybraných prvků v lidských vlasech / Representation of selected elements in human hair

Jochimová, Eva January 2010 (has links)
Hair is an excellent matrix for monitoring trace elements and minerals in the body. To long-term changes in concentration of elements in the body are reflected in their value in her hair, so the assessment of the organism from the mineral analysis of hair is a very suitable method. This method is widely used in toxicological testing and forensics. This work deals with the analysis of Mg, K, Fe, Zn, Mn, Se, As, Cd and Pb in 100 samples by ICP-MS. It is a male hair samples with the age range 19 – 74 years. Analysis of hair revealed that concentrations of individual elements are moving in a narrow range of values. Values of older age category are in some case significantly deflective.
53

Elektrody pro elektrolyzér / Electrodes for electrolyser

Kaňa, Ondřej January 2009 (has links)
In my diploma work i focus on the production hydrogen by electrolysis of water using by electrolyzer. Especially, i concentrate on preparation electrodes for laboratory electrolyzer. I work on principles of increasing electrodes area, increasing functional surface of electrodes, by Nickel – Zinc coatings. By electroplating or chemical plating we spread microlayer of Nickel-Zinc onto electrodes made of steel plate. Then, in alkali - hydrate oxide, we will corrode Zinc components off the alloy and this is how we create pore surface of electrode. From macroscopic view, electrode has same geometrics propositions, however from microscopics view, the electrode has bigger surface area. The hydrogen production increases with unchanget sizes of electrolyzer.
54

Role akumulace železa a dalších kovů v patofyziologii neurodegenerativních onemocnění / The role of accumulation of iron and other metals in the pathophysiology of neurodegenerative diseases

Mašková, Jana January 2020 (has links)
The role of metal accumulation in the pathophysiology of neurodegenerative diseases has been a hot topic in recent years due to the possibility of its treatment by chelating agents. Although the mechanisms of neurodegeneration are well known, the role of metal accumulation is still unclear. The main limitation are unsatisfactory methods for in vivo metal imaging; the most widely used technique is magnetic resonance imaging (MRI). Our aim was to assess the possibility of using transcranial sonography (TCS) in differential diagnosis of neurodegenerative diseases and to further explore the underlying factors of echogenicity. In the first study, using TCS fusion with MRI, we focused on location verification of the commonly assessed structures (substantia nigra and nucleus lentiformis) and exclusion of possible focal structural changes affecting the echogenicity in WD and PD patients. Moreover, obtained MRI were used for semi-quantitative comparison with TCS images. Although TCS has been confirmed to be highly beneficial in differential diagnosis of Wilson's disease and it should be recommended as a screening method for extrapyramidal patients with atypical course of the disease, the direct relationship between TCS and metal deposits could not be proven. The obtained results from the ultrasound fusion...
55

Zelené řasy dominující ve fytoplanktonu dvou kyselých jezer: taxonomické postavení, fylogenetické vztahy a odolnost vůči kovům / Taxonomic position, phylogenetic relationships and metal resistance of green algae dominating in phytoplankton of two acid lakes

Barcyte, Dovile January 2015 (has links)
The aim of this diploma thesis was to reveal the taxonomic position and phylogenetic relationships of the dominant planktonic algae in two acid metal-rich lakes (Hromnice Lake and Plešné Lake, Czech Republic) and to compare these isolates with other closely related strains with the focus on the tolerance to various toxic metals (Cr, Al, Cu, Mn, Zn, Hg). The phylogenetic analyses showed that both strains belong to species Coccomyxa simplex. It was the first evidence that specifically this species is capable to become the dominant phytoplankton alga in the extreme environment of acid lakes with increased supply of phosphorus. Based on 18S rDNA analysis, four independent phylogenetic lineages were revealed within the genus Coccomyxa with three of them containing isolates from acid freshwaters. Furthermore, new strains of the recently described species Coccomyxa polymorpha were found growing in various chemical solutions. The toxicity test revealed that Coccomyxa simplex strains isolated from Hromnice and Plešné lakes did not show any peculiar resistance to increased metal concentrations. A significantly strain-specific response was recorded in case of aluminum, however, it was not related to the concentration of this metal in the original habitat. The ability to thrive in extreme habitats is probably...
56

Počítačové modelování interakcí iont ů s proteiny: Allosterický efekt iont ů a fenolických ligand ů na strukturu insulinového hexameru / Computer modeling of ion protein interactions: Allo steric effects of phenolic ligands and ions on insulin hexamer struct ure

Palivec, Vladimír January 2016 (has links)
Title: Computer modeling of ion protein interactions: Allosteric effects of phenolic ligands and ions on insulin hexamer structure Author: Vladimír Palivec Department: Department of Physical and Macromolecular Chemistry Faculty of Science UK Advisor: prof. RNDr. Pavel Jungwirth, DSc., IOCB AS CR, v.v.i. Advisor's email address: pavel.jungwirth@uochb.cas.cz Abstract: Insulin hexamer is an allosteric protein capable of undergoing conformational changes between three states: T6, T3R3, and R6. Transitions between them, as well as the formation of insulin hexamers, are mediated through binding of phenolic ligands or ions. This thesis presents a molecular dynamics study of allosteric behavior of insulin using empirical force fields. Two effects are closely inspected - cation (Zn2+ , Ca2+ , K+ , and Na+ ) binding to the insulin hexamers and a possible binding of two neurotransmitters - dopamine and serotonin to the phenolic pocket. The results show that high charge density cations (Zn2+ and Ca2+ ) are mostly localized in the B13 glutamate cavity, slow- down diffusion, while preventing other cations from entering. In contrast, low charge density cations (Na+ and K+ ) do not have this effect. Concerning neurotransmitters, dopamine does not bind to the phenolic pocket whereas serotonin binds in a similar way like...
57

Výskyt těžkých kovů v okolí pozemní komunikace Rudná / Presence of heavy metals near the way Rudná

Chovanec, Petr January 2011 (has links)
These diploma thesis is focused on assessment of hazardous metals in soils near the road Rudná in Ostrava. Seventeen sampling sites have been chosen along this road, samples from this sites were collected in three series. The amounts of mercury, lead, copper, cadmium, zinc, vanadium and manganese were determined. There was also assessed contamination of selected sites using contamination factor and degree of contamination.
58

Stanovení rizikových prvků v půdách s různým antropogenním znečištěním pomocí sekvenční extrakční analýzy / Determination of hazardous elements in soils with different anthropogenic contamination using sequential extraction analysis

Židek, Michal January 2012 (has links)
This diploma thesis deals about determination of hazardous elements and their mobility in soils from Brno and Ostrava. For extraction of soil samples was used sequential extraction by Tessier and BCR sequential extraction. Extraction by nitric acid was also used. Mercury was determinated by the advanced mercury analyser AMA 254. Lead, copper and zinc were determinated by the flame atomic absorption spectrometry. Cadmium and vanadium were determinated by the electrotermic atomic absorption.
59

Sezónní dynamika vybraných krevních parametrů u vybraných masných plemen ovcí chovaných v podhorských podmínkách / Seasonal dynamics of selected blood parametres of selected flesh breeds of sheep bred in foothills conditions

ŽÁČKOVÁ, Klára January 2009 (has links)
Sheep breeding is nowadays a developing branch of agriculture again. There is a lot of different breed and they react distinctly on the same conditions of the enviroment. Sheep of breeds charollais, suffolk, šumavská ovce and valaška bred in similar conditions were observed in spring and autumn of years 2007 and 2008. In these seasons were taking blood samples (from {$\pm$}7{--}24) ewes and lambs and were analyzed in hematology laboratory. There were determined haemoglobin level, haematocrit indicator, erytrocytes and leucocytes levels, glucose, cholesterol, triglycerides levels, urea and plasmatic proteins, activity of ALP and GMT enzymes, phosphor, calcium, magnesium, zinc and copper levels. The main objective of this project was determine seasonal changes in observed parametres. Next objectives were determine different changes in blood parametres in different breeds and different aimes of breeds. There were recognized that all the observed breeds don`t react the same way on similar conditions. There were not provably determined seasonal changes in observed parametres, but average Hb level was higher in autumn than in spring. Urea level was conversely higher in spring season than in autumn. The demostrable fact is, that the similar conditions induce different answers not only in different breeds but also in different aimes of breeds.
60

Studium ovlivnění hydratace portlandského cementu působením zinku / The study of zinc influence on Portland cement hydration.

Ptáček, Martin January 2019 (has links)
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.

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