National Repository of Grey Literature 43 records found  beginprevious21 - 30nextend  jump to record: Search took 0.02 seconds. 
Selected ion flow tube mass spectrometry, SIFT-MS
Sovová, Kristýna
4 Abstract This thesis describes research that has been carried out during the years 2009-2013 as a part of my PhD project related to the method of selected ion flow tube mass spectrometry (SIFT- MS) and its application in interdisciplinary areas of research. SIFT-MS is a method that allows accurate quantification of trace gases and vapours presented in humid air with the focus on human breath; without any sample preparation and in real time. The thesis is divided into several parts. The first part reviews the history of mass spectrometry as a background for the quantitative analytical methods as PTR-MS and SIFT-MS. The second part discusses the detailed history of development of SIFT-MS, starting from principles of selected ion flow tube (SIFT) technique that has been used for study of ion- molecule reactions in the gas phase and forms the basis of SIFT-MS. The next part discusses volatile organic compounds of different biological origin: bacterial, plant and human breath metabolites that can be analyzed in real time using SIFT-MS. The main part "Results and Discussion" is divided into several subsections that serve as commentaries to the enclosed research papers published in peer reviewed journals. The first is a detailed step by step overview of the kinetics of ion molecule reactions which is the basis...
Selected ion flow tube mass spectrometry, SIFT-MS
Sovová, Kristýna ; Španěl, Patrik (advisor) ; Glosík, Juraj (referee) ; Matejčík, Štefan (referee)
This thesis describes research that has been carried out during the years 2009-2013 as a part of my PhD project related to the method of selected ion flow tube mass spectrometry (SIFT-MS) and its application in interdisciplinary areas of research. SIFT-MS is a method that allows accurate quantification of trace gases and vapours presented in humid air with the focus on human breath; without any sample preparation and in real time. The thesis is divided into several parts. The first part reviews the history of mass spectrometry as a background for the quantitative analytical methods as PTR-MS and SIFT-MS. The second part discusses the detailed history of development of SIFT-MS, starting from principles of selected ion flow tube (SIFT) technique that has been used for study of ion-molecule reactions in the gas phase and forms the basis of SIFT-MS. The next part discusses volatile organic compounds of different biological origin: bacterial, plant and human breath metabolites that can be analyzed in real time using SIFT-MS. The main part "Results and Discussion" is divided into several subsections that serve as commentaries to the enclosed research papers published in peer reviewed journals. The first is a detailed step by step overview of the kinetics of ion molecule reactions which is the basis of...
Modulation of HIV-1 Protease Activity
Pokorná, Jana ; Konvalinka, Jan (advisor) ; Šedo, Aleksi (referee) ; Ruml, Tomáš (referee)
HIV-1 protease plays a crucial role in the late state of the life cycle of HIV virus when it cleaves the viral polyprotein precursors into the structural and functional proteins. If it is effectively inhibited, HIV particles remain immature and noninfectious. The application of highly active antiretroviral therapy (HAART) including protease inhibitors can reduce plasma HIV-1 levels below the detection limit in adherent patients and thus dramatically change their life expectancy. The clinical utility of the first inhibitors was limited by severe side effects, low bioavailability, high pill burdens, and rapid development of viral resistance under the selection pressure of HIV antiretrovirals. To overcome these difficulties, second-generation inhibitors were developed. Despite an indisputable improvement they brought to antiretroviral therapy, the development of new highly active HIV-1 protease inhibitors with optimal pharmacokinetic properties, higher metabolic stability, little off-target activity, and particularly, more favorable resistance profiles is still of high importance. This thesis provides an overview of anti-HIV- drugs including development of substituted metallacarboranes, a new class of potent, unusual, nonpeptidic HIV protease inhibitors with therapeutic potential. Next, the impact of...
Study of the cleavage kinetics of Gag polyprotein from HIV-1 virus by the viral proteinase
Krištofičová, Ivica ; Ingr, Marek (advisor) ; Martínek, Václav (referee)
Gag polyprotein is the precursor of HIV-1 structural proteins, required for correct assembly, budding and maturation of viral particle within HIV-1 life cycle. The process of maturation into an infectious virion is dependent on Gag and GagPol cleavage at nine predefined sites by HIV-1 proteinase. Its disruption is one of the main targets of HIV treatment. HIV-1, however, develops resistance to the proteinase inhibitors by creating mutations in both the proteinase and the substrate. The Gag processing by HIV-1 proteinase is a highly sequential process, that happens in specific order and rate. Previous biochemical studies determined the kinetic data of these processes using oligopeptides representing naturally occuring cleavage sites. This thesis describes the cleavage of the Gag polyprotein itself, which is the natural substrate of HIV-1 proteinase. For this purpose, the full-length Gag polyprotein was recombinantly prepared in bacterial expression system. The cleavage was carried out and its products were analyzed via SDS-PAGE and Western blotting. The substrate specificity of the wild-type and mutant HIV-1 proteinase with respect to the full-length wild-type Gag polyprotein was compared. Substantial differences were observed between the rates of individual steps of cleavage by the wild-type and mutant...
Physics Simulation on GPU
Janošík, Ondřej ; Zemčík, Pavel (referee) ; Polok, Lukáš (advisor)
This thesis addresses the issue of rigid body simulation and possibilities of paralellization using GPU. It describes the basics necessary for implementation of basic physics engine for blocks and technologies which can be used for acceleration. In my thesis, I describe approach which allowed me to gradually accellerate physics simulation using OpenCL. Each significant change is described in its own section and includes measurement results with short summary.
Photochemical degradation of dissolved organic matter - the kinetics of insoluble particles
ŠAVRDOVÁ, Tereza
This bachelor thesis deals with the kinetics of the formation of insoluble substances. In the theoretical part we will deal with photochemistry, kinetics and organic substances. What forms of aluminum and iron can be found in aquatic environments with different pH values. In the experimental part we will examine the kinetics of the formation of insoluble particles in water after photochemical irradiation. We will find out how it changes the concentration of aluminum, iron and carbon according to the length of irradiation and how pH can affect the final result.
Humic substances as transport medium for plant nutrition
Vlková, Markéta ; Solná, Irena (referee) ; Klučáková, Martina (advisor)
This bachelor thesis treats about humic matters and their application in agriculture by means of hydrogels transport medium. It studies progressive releasing of substances, which could be used as more common nutrition for plants, prepared from superabsorbent polymers. Research was implemented in collaboration with industrial partners. The substances are synthetically made of sodium Lignohumate and mixture of industrial fertilizer called NPK. Released substances were characterized by using some methods. First, there were measured qualities, which didn’t specify released compounds, like swelling, conductivity, pH and absorption of hydrogels with different wavelengths. More details came with methods ICP-OES and ion chromatography. Hydrogels which contained both mixtures of matters written up, were studied in water solution for 5 weeks and every week all characterization were measured. From the results we can see that both of the mixtures decrease ability of hydrogel’s swelling, mainly NPK. Measuring of absorption showed that the most of the substances released from sodium Lignohumate were from hydrogels without NPK. By other measuring, we noticed realizing of potassium and phosphorus elements. The most of them were from hydrogels containing NPK. By measuring ion chromatography, we found chloride, phosphoric, sulfuric and nitric ions in solution.
Printed light dosimeter for galleries
Škarvadová, Adéla ; Klusoň, Petr (referee) ; Veselý, Michal (advisor)
This bachelor thesis deals with the lighting of the gallery space and the measurement of light intensity inside. The subject of the experimental study are photosensitive composition for the production of disposable printed and thin-film dosimeters for galleries and museums. Kinetic color change of the two systems using two dyes and calibration components was examined. The composition for printing was optimized and dosimeters were prepared with a wide range of light exposure causing a significant color change of the dosimeter, and that from 1,7 klx•h to 200 klx•h.
Catalytic oxidation of VOC on commercially available catalysts
Osička, Tomáš ; Jecha, David (referee) ; Brummer, Vladimír (advisor)
The main topic of this thesis is a catalytic oxidation which belongs to a group of modern technologies for removing emission of CO and VOC from waste air. In the introduction of this thesis, the basic concepts are defined. Further the legislative requirements associated with VOC emissions, emission limits and conditions are summarized. Described destructive and non-destructive methods for removing VOCs from waste gases are also briefly described. Increased attention is paid to the catalytic oxidation as the main theme of the thesis. It was searched for industrial applications where the catalytic oxidation is used. Another chapter is devoted to the theoretical analysis of kinetics of catalytic oxidation reactions. Firstly, the basic types of reactors are described and also material balance and reaction rate for the isothermal and adiabatic reactor. In the experimental part results of performed kinetic measurements on a pilot unit for catalytic commonly used organic solvents (VOCs) using commercially available catalysts were summarized. Pre-exponential factors and activation energies for sprinkling catalysts EnviCat VOC-5565 and EnviCat 55068 for substances ethanol, toluene and acetone were determined. "Light-off" curves for these substances and methane were measured and on sprinkled catalyst EnviCat 55068 and on monolithic catalyst Purelyst PH-304.

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