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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.
31

Měření a toxicita nanočástic ze spalovacích procesů / Measurement and toxicity of combustion generated nanoparticles

Sikorová, Jitka January 2020 (has links)
This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...
32

Expozice toxickým koncentracím kyslíku u nemocných na KAR / Exposure to toxic concentrations of oxygen in ICU patients

Petránková, Eliška January 2020 (has links)
Oxygen supplementation has been an important part of respiratory failure treatment in all fields of clinical medicine, especially on intensive care units (hereinafter referred to as ICU). Oxygen therapy is a life-saving measure but indiscriminate administration of oxygen can cause lung and nerve damage and consequently increase morbidity and mortality (1). In clinical practice we often encounter mechanically ventilated patients with high partial pressures of oxygen in arterial blood (5) which should direct our attention to possible consequences and have reliable data how is oxygen treatment managed. This thesis focuses on the exposure to toxic concentrations of oxygen on the resuscitation ward. The aim of this thesis is to determine whether patients are exposed to high concentrations of oxygen. Two other aims of this study are to find out how long are patients in a state of hyperoxemia and whether medical staff reacts to measured partial pressures of oxygen (hereinafter referred to as paO2) values in these patients by reducing oxygen fraction (hereinafter referred to as FiO2) on the ventilator. The research part of this thesis is a quantitative observational retrospective research. The inclusion criteria were hospital admission from 1st July to 1st October 2019, at least two paO2 values greater...
33

Vliv huminové látky HS 1500 na toleranci jesetera malého vůči dusitanům / Influence of humic substance HS 1500 on tolerance of Sterlet to nitrite

BULÍČEK, Vojtěch January 2014 (has links)
The aim of the thesis was to assess the effect of humic substance HS 1500 on the tolerance of Sterlet (Acipenser ruthenus) to nitrite. Preparation Huminfeed was used as a source of substance HS 1500. Tolerance of Sterlet to nitrite was assessed on the basis of the results of acute toxicity tests and the results of haematological and biochemical blood examination of fish that were exposed to increased concentrations of nitrite in the presence and absence of preparation Huminfeed.
34

Zdroje rizika chladících zařízení s amoniakem a jejich případné havarijní dopady / Risk sources of ammonia refrigeration equipment and their possible impacts

MIRANDOVÁ, Růžena January 2010 (has links)
I have decided to deal with the issue of "Risk Sources of Ammonia Cooling Systems and Their Eventual Accidental Impacts" as the risk of leakage from the cooling systems using ammonia as a coolant still prevails these days. Eventual accidental leakage simulation models were applied to several winter stadiums using ammonia as a coolant. Based on these results, it has been assessed how dangerous these sources for the citizens living in their surroundings are and measures to increase safety were suggested, too.
35

Užití biodegradabilních polymerních konjugátů s vysokou molekulovou hmotností k účinnému/ doručení cytostatických léčiv do solidních nádorů. / Biodegradable high molecular weight polymeric conjugates for efficient delivery of cytostatic drugs into solid tumors.

Černý, Viktor January 2015 (has links)
Cancer remains one of the most pressing issues of contemporary science and medicine. Incidence of malignant diseases is rising worldwide and they represent a major problem for the society due to both economic and ethical issues they cause. Although the progress in cancer biology, therapy and immunology has led to the introduction of many novel therapeutic protocols, approaches and drugs with specificity defined on a molecular level into clinical practice, many malignancies retain their poor prognosis. Therefore, intense research into new ways to increase our therapeutic options is warranted. Unfortunately, bringing a completely novel drug into clinical use takes extremely high amounts of time and money and entails a high risk of failure. Therefore, a promising approach has been recently adopted which lies in repurposing compounds already used in human medicine for cancer treatment. This form of research can advance through clinical trials for a new indication much easier, faster and cheaper than researching completely new drugs. The aim of this study was to examine the anticancer potential of one such drug, mebendazole. An anthelminthic from the family of benzimidazoles, mebendazole has been in common clinical use from the 1970s and is marked by its low toxicity as well as its very low solubility....
36

Detekce luminiscenčních nanočástic v rostlinách laserovou spektoroskopií / Detection of luminescent nanoparticles in plants by laser spectroscopy

Střítežská, Sára January 2021 (has links)
This diploma thesis deals with evaluation of toxicity and bioaccumulation of photon-upconversion nanoparticles (UCNPs) in model plant maize (Zea mays). Lanthanide-doped UCNPs with different composition and size were tested in three different concentrations in this work. The exposure took place for 168 hours. Toxicity was assessed based on four macroscopic toxicological endpoints (mortality, the length of belowground part of the plants, the length of aboveground part of the plants and whole plants length). Spatial distribution of elements yttrium, ytterbium, erbium and gadolinium in model plants was determined using laser induced breakdown spectroscopy with spatial resolution of 100 m and 26 m. Distribution of UCNPs in plants was further studied with photon-upconversion microscanning with spatial resolution of 40 m. Stability of UCNPs during and after the plant exposure was also discussed in this thesis.
37

Kontaminace vybraných částí města Brna těžkými kovy / Heavy metals contamination of selected Brno city localities

Debnárová, Andrea January 2010 (has links)
This thesis is focused on the degree of soil contamination with heavy metals in urban area of Brno. Samples were collected in three periods from October 2009 to March 2010, to represent different seasons and their impact on the concentration of heavy metals in examined soil. Ten locations was chosen, each with different level of concentration, starting with busy traffic area where the concentration of means was high continuing to areas located around habitation or parks. As result four elements were determined in every sample: Cu, Cd, Hg and Pb. Presence of copper and lead were detected by flame atomic absortion spectroscopy (F-AAS) and, cadmium by the help of electrothermal atomic absortion spectroscopy (ET-AAS). For the determination of mercury was used advanced mercury analyzer (AMA).
38

Možnosti redukce šestimocného chromu při hydrataci portlandského cementu / Possibilities of hexavalent chromium reduction within portland cement hydration

Mončeková, Miroslava January 2012 (has links)
The issue of Hexavalent chromium toxicity to Portland cement hydration is a very actual these days. It takes much effort to obtain a cement containing Cr(VI) less than 2 ppm. The primary objective of this diploma theses is to find appropriate reducing substances and specify their efficiency, as well as to make an attempt to optimize their dosage. As reducing substances there were plumbed sulphites and tin(II) salts. The influence of reducing substances applied to the hydration and cement properties were validated by strenght tests, the calorimetric measurement and the volume-variation measurement. And also the changes in hydration products microstructure of Portland clinker after the gypsum replacement by sulphite ions were plumbed. The study of microstructure is based on SEM and XRD methods.
39

Studium vlivu požárů skládek komunálních a průmyslových odpadů na kontaminaci životního prostředí, produkty hoření pryže a halogenovaných polymerů / Study of the influence of fires of municipal and industrial waste landfills on the enviromental contamination, the combustion products of rubber and halogenated polymers

Sikora, Henryk January 2014 (has links)
This thesis deals with the issue of fires of municipal and industrial wastes, particularly of rubber and halogenated polymers. When these materials burn, significant amount of harmful substances liberate into environmental compartments. Analysis of samples subjected to thermal decomposition in laboratory conditions explored formation of characteristic compounds in dependence on conditions of combustion. Samples of air, water and soil taken from real fires that occurred between the years 2007 – 2011 in the region of Western Bohemia monitored spreading of these substances into the environment. Majority of these samples were analysed by the means of gas chromatography with mass spectrometric detection. Additionally the effect of extinguishing methods and use of fire extinguishers on formation and spreading of combustion products was studied, especially in soil and in water sources.
40

Značení T buněk bimodální kontrastní látkou pro studium mrtvice in vivo / T cells labelling by bimodal contrast agent for in vivo studies of stroke

Krijt, Matyáš January 2012 (has links)
Stroke is a serious brain injury, which causes sudden death or terminates in permanent neurological disability. Nowadays, tissue plasminogen activator (tPA) is used as the only effective treatment of stroke. One of the potential targets for novel therapy are T cells. Even though the explicit role of T cells in the pathogenesis of brain injury, amounts and timing of all T cell subtypes infiltrating into brain during the stroke still needs further investigation. The research in this field is complicated by the lack of efficient methods for in vivo cell tracking. Therefore the aim of this thesis was to develop a method of T cells labelling by MRI contrast agent in order to investigate T cells distribution in ischemic mice model using in vivo MR imaging. T cells were isolated from C57/BL6 mice in two step isolation protocol using gradient centrifugation and magnetic separation with the efficiency of 97 %. The isolated cells were labelled with 100 μg Fe/mL of Molday ION Rhodamine B contrast agent. The labelling efficiency after 17 hours of cells incubation was higher than 99 %. The labelled cells were cultured with CD3 and CD28 antibodies resulting into the 74 % viability of labelled T cells compared to 83 % viability of non labelled T cells. The labelled T cells were visualized by fluorescent...

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