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Preparation and testing of silver immobilized nanoparticles for SERS spectroscopy of biomolecules
Molnár, Peter ; Procházka, Marek (advisor) ; Šmejkal, Petr (referee)
Main goal of this work was to develop methodology of immobilization of silver nanoparticles to silanized glass plates and employment of these substrates in biomolecular study using surface-enhanced Raman scattering (SERS). The suitable substrates for SERS spectroscopy, borohydride-reduced colloidal nanoparticles immobilized by mercapto- or aminosilane, have been found. Good SERS spectra of positively charged TMPyP porphyrin as well as of water insoluble TPP porphyrin (without interference of the solvent) have been obtained. Our results clearly show, that our substrates provide unique possibility how to measure SERS spectra of the porphyrins in his native free-base form (what is impossible directly from the colloid). Further experiments confirm that the porphyrins are protected against metalation due to the presence of the silane employed for the silver particles immobilization.
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Physiotherapy for gastroesophageal reflux
ŠIRMAROVÁ, Jitka
This thesis deals with the issue of etiology and gastroesophageal reflux disease (GERD). It has been proved that the locomotor system affects occurrence of this disease in many aspects therefore, apart from the primary care of gastroenterologists and general practitioners, treatment using physiotherapeutic techniques becomes significant. Sphincter mechanism at the lower end of the oesophagus being the most important anti-reflux barrier in terms of function is described in the theoretical part in detail. Possible ways and factors involved in occurrence of gastroesophageal reflux and then current treatment of gastroesophageal reflux disease are mentioned. The other part of the theoretical part is aimed at: relations between the internal organs and locomotor system, the diaphragm function and its relation to occurrence of GERD, and possibilities of rehabilitation treatment of patients with this disease. The goal of the theoretical part was to provide a research on the current situation. The practical part was prepared by means of a qualitative research. The tested set consisted of three patients diagnosed with GERD being treated at the Gastroenterological Ward in České Budějovice Hospital. Patients? anamneses were taken and kinesiological testing was done. Similarly, all three patients were identified with a disorder of trunk stabilization. Upon this, individual therapies were proposed and carried out, which was the goal of the practical part, too. Physiotherapy was aimed at: affecting the position of the rib cage and improving its dynamics while breathing, training of breathing stereotype, activation of the abdominal wall, affecting the stabilizing function of legs, exercises in developmental series and modified positions, Jacobson's progressive muscle relaxation, and affecting reflexive changes using soft techniques. The research issue was whether the symptoms of GERD could be affected by treatment of functional disorders of the locomotor system in a positive way. There were certain changes in the kinesiological testing (e.g. change in the activity of lower and upper fixators of scapulae with relaxation of the trapezius, releasing the rigidity of the chest, affecting the dynamic stability of the body) during a three-month therapy. However, functional disorders were not affected that much so any described symptoms of GERD could be changed. The results of the therapy were limited by motivation, attitude and patients? metal state. Not only the internal organ but also the locomotor system probably plays a role in occurrence of the reflux; but also psyche, and all these parts of a human being affect each other. Therefore the treatment of a multifactorial disease such as GERD should be comprehensive. Apart from physiotherapy, metal area, too, and all factors should be treated at the same time, which requires interdisciplinary cooperation unfortunately lagging behind.
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Immobilization of heavy metals in the cement matrix with the admixture of natural zeolite
Semerádová, Nikol ; Bayer, Patrik (referee) ; Vyšvařil, Martin (advisor)
Heavy metals released to the natural ecosystem constitute significant risks not only for organisms, but also for water supplies in the nature. There are a number of analytical methods for the determination of heavy metals. Each of them is suitable for different element and its character. Since the results of the analysis are applied during the solidification and stabilization, it is necessary to ensure the highest correlation between hazardous waste and solidification medium for maximum inhibition of toxic ions. This work investigates the stabilization of heavy metals binders based on cement base with admixture of the natural zeolite and its possible use for the solidification of heavy metals in soluble form.
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THE INVESTIGATION OF AN Al7075 ALLOY PREPARED BY SPARK PLASMA SINTERING OF MILLED POWDERS
Molnárová, O. ; Málek, P. ; Nemeth, G. ; Kozlík, J. ; Lukáč, František ; Chráska, Tomáš ; Cinert, Jakub
Atomized powder of an Al7075 alloy was high energy ball milled at room and cryogenic temperatures and compacted by spark plasma sintering (SPS) method. The influence of processing parameters on phase composition and microstructure was studied by X-ray diffraction, light and scanning electron microscopy. The mechanical properties were characterized by microhardness measurements. The atomized powder contained a large volume fraction of intermetallic phases located predominantly in continuous layers separating cells or dendrites in the interior of individual powder particles. Consolidation by SPS destroyed partially this morphology and replaced it by individual particles located at boundaries of original powder particles, at cell boundaries or arranged in chains in previous dendritic regions. High energy milling destroyed most intermetallic particles and enriched the matrix by solute atoms. The high deformation energy introduced into the powder during milling enhanced microhardness up to 220 HV. Consolidation of milled powders by SPS led to the formation of very fine-grained structure with the grain size even below 1 μm and with the fraction of high-angle boundaries about 0.9. Two main types of heterogeneously distributed precipitates were found. The irregularly shaped precipitates with a size about 1 μm seemed to encompass areas with rod like nano-precipitates in most samples. A drop in microhardness to 118HV was observed after SPS, predominantly due to a release of introduced deformation energy.
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Plasma preparation of metal and oxide layers on ceramic and plastic substrates.
Olejníček, Jiří
Contract research was focused on preparation and optimization of the plasma deposition process of selected thin metal and semiconducting oxide layers with required optical properties. The goal was to prepare transparent color electrochromic films on thermally sensitive substrates, the layers with high refractive index on the surface of pressed plastic structures and shiny metallic films on the porous ceramic masks.\n
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Properties and in vitro Degradation of Metalic Biodegradable Materials
Ročňáková, Ivana ; Trojanová, Zuzanka (referee) ; Vojtěch,, Dalibor (referee) ; Podrábský, Tomáš (advisor)
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.
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Gas Microsensors Based on Self-Organized 3D Metal-Oxide Nanofilms
Pytlíček, Zdeněk ; Husák, Miroslav (referee) ; Kolařík, Vladimír (referee) ; Prášek, Jan (advisor)
This dissertation concerns the development, fabrication and integration in a gas sensing microdevice of a novel 3-dimensional (3D) nanostructured metal-oxide semiconducting film that effectively merges the benefits of inorganic nanomaterials with the simplicity offered by non-lithographic electrochemistry-based preparation techniques. The film is synthesized via the porous-anodic-alumina-assisted anodizing of an Al/Nb metal bilayer sputter-deposited on a SiO2/Si substrate and is basically composed of a 200 nm thick NbO2 layer holding an array of upright-standing spatially separated Nb2O5 nanocolumns, being 50 nm wide, up to 900 nm long and of 8109 cm2 population density. The nanocolumns work as semiconducting nano-channels, whose resistivity is greatly impacted by the surface and interface reactions. Either Pt or Au patterned electrodes are prepared on the top of the nanocolumn array using an innovative sensor design realized by means of microfabrication technology or via a direct original point electrodeposition technique, followed by selective dissolution of the alumina overlayer. For gas-sensing tests the film is mounted on a standard TO-8 package using the wire-bonding technique. Electrical characterization of the 3D niobium-oxide nanofilm reveals asymmetric electron transport properties due to a Schottky barrier that forms at the Au/Nb2O5 or Pt/Nb2O5 interface. Effects of the active film morphology, structure and composition on the electrical and gas-sensing performance focusing on sensitivity, selectivity, detection limits and response/recovery rates are explored in experimental detection of hydrogen gas and ammonia. The fast and intensive response to H2 confirms the potential of the 3D niobium-oxide nanofilm as highly appropriate active layer for sensing application. A computer-aided microfluidics simulation of gas diffusion in the 3D nanofilm predicts a possibility to substantially improve the gas-sensing performance through the formation of a perforated top electrode, optimizing the film morphology, altering the crystal structure and by introducing certain innovations in the electrode design. Preliminary experiments show that a 3D nanofilm synthesized from an alternative Al/W metal bilayer is another promising candidate for advanced sensor applications. The techniques and materials employed in this work are advantageous for developing technically simple, cost-effective and environmentally friendly solutions for practical micro- and nanodevices, where the well-defined nano-channels for charge carriers and surface reactions may bring unprecedented benefits.
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Preparation of Magnesium Silicide from Recycled Materials for Energy Storage.
Bumba, Jakub ; Dytrych, Pavel ; Šolcová, Olga ; Koštejn, Martin ; Fajgar, Radek ; Maléterová, Ywetta ; Kaštánek, František
Recycling technologies help to save energy, materials and environment. This is the main reason of their popularity. The recovery of semiconductors and metals depends on recycling treatment. A new multi-step technology, which enables to obtain pure silicon and hydrogen from waste materials,is reported in this study. The only by-product is magnesium phosphate, which is a desired fertilizer. Magnesium silicide was successfully prepared from milled silicon photovoltaic (PV) panels and milled Mg obtained from the scrap. The formed magnesium silicide was then hydrolysed by phosphoric acid to form a mixture of silanes. Gaseous products (silanes) were separated by cooling below their boiling temperature by liquid nitrogen and then thermally decomposed by a hot wire, e.g. Pt.This treatment leads to pure silicon and hydrogen release. In this study a deep-in characterization by various methods spectroscopy, Scanning Electron Microscopy (SEM) with Energy Dispersive X- Ray spectroscopy (EDX), etc.) of prepared samples was also done to explain the individual influences, e.g. reaction temperature and atmosphere.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22016111814301 - PDF
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Ecology of Calamagrostis epigejos (L.) Roth
Vachová, Pavla ; Hejcman, Michal (advisor)
Ecology of expansion species is still a hot topic. The antropogenic landscape gradually occurred since the Neolithic . The result has been a change in the structure of plant communities and the successful expansion of species such as Calamagrostis epigejos.
C. epigejos is expansive, perennial, long-stemmed, rhizomatous grass. Its important characteristic are very large ecological amplitude, high biomass production and a ability adjust habitat conditions.
Experiments and studies that are included in dissertation, have the following basic objectives: (1) Investigate the expansion of C. epigejos in plant community. (2) Investigate the theoretical degree of stability of this phytocenosis. (3) Determine the response of C. epigejos to nutrients availability. (4) Test of possibility eliminating of C. epigejos. (5) Suggest a practical use of C. epigeos.
Primarily, we monitored the reaction of interest species to management (aplication of N, P, K nutrients, mowing in various combinations). We were interested in its behavior in the plant community. It founded field and pot experiment. Results of field experiment were also used to calculate the theoretical measure of the stability of individual variants. Further research has been directed at eliminating C. epigejos using wireworms (Elateridae larvae species). The study which uses C epigejos for monitoring of deposition of heavy metals, has shown that aspects of the global expansion of the grass are not always negative.
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