National Repository of Grey Literature 57 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
The usage of the "Ethanol as internal standard" method for the SPME-GC/FID analysis of volatile compounds in alcoholic products
Zavoralová, Lucie ; Korban, Anton (advisor) ; Sobotníková, Jana (referee)
This bachelor thesis dealt with the optimization of a method for the determination of 10 volatile compounds occurring as minor components in alcoholic products. The quantification was performed by the internal standard method, comparing the results using 1-pentanol and ethanol as classical and proposed internal standards, respectively. In the case of ethanol usage, better repeatability and accuracy of the results were expected as this method does not require any sample pre-treatment. The optimized measurement method was monitored for both internal standards, while following these parameters - repeatability, recovery, linearity and limits of detection and quantification. It was found out that, as expected, the method of the proposed ethanol internal standard gives more accurate results for the analysis of real alcoholic beverage samples. However, it did not outperform the classical internal standard method in all parameters. That one gave better results for repeatability and linearity for the set of calibration solutions measured, despite the fact that each sample had to be pre-treated. It was also found that samples with a high ethanol or other volatile content were not suitable for SPME analysis, because the fibre then loses its ability to sorb these substances in the same proportions and...
The influence of tanning chemical agens on DNA degradation
Hebenstreitová, Kristýna ; Vaněk, Daniel (advisor) ; Novák, Jindřich (referee)
The illegal wildlife trade is currently on the rise, and it is becoming the fourth most lucrative sector of crime. The traded commodities of this sector are, for example, various animal artefacts from skins, teeth, scales, tusks, claws to whole animal bodies, as well as eggs of endangered birds (parrots and birds of prey) or amphibians and snakes. The rarer the species is, the higher the demand for it grows. Wildlife trade is regulated (among other things) under the international CITES convention (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Proving that this convention has been violated, is complex process and can be very difficult to achieve. In many cases a DNA analysis of the artefact, is the only way to prove, that it originates from a protected animal species and not from a species with which it is legal to trade. This thesis deals with a specific type of animal artefact - tanned skins. With this type of biological material, it is often problematic to obtain amplifiable DNA (deoxyribonucleic acid). This thesis is investigating the influence of the chemicals used in the tanning process on the DNA degradation. Furthermore, it analyses, the influence of these substances on the inhibition of the polymerase chain reaction. The quantity of DNA is determined...
Comparison of molecular diagnostic approaches for the detection and differentiation of the intestinal protist Blastocystis sp. in humans
ŠLOUFOVÁ, Martina
Blastocystis is the most commonly found intestinal protist in the world. Accurate detection and differentiation of Blastocystis including its subtypes (arguably species) is essential for understanding its epidemiology and role in human health. We compared the sensitivity of conventional PCR (cPCR) and qPCR in a set of 288 DNA samples obtained from stool samples of gut-healthy individuals and subtype diversity as detected by next-generation sequencing (NGS) versus Sanger sequencing.
Quantification of main solution components by using fragments containing heavy nuclides of common elements
Horká, Blanka ; Čabala, Radomír (advisor) ; Bajer, Tomáš (referee)
Quantification of major components by gas chromatography with flame-ionization detector (GC-FID) is established in routine laboratory practice. The FID detector is considered as universal detector for gas chromatography (GC), but it does not provide a response for a wide range of compounds and GC-FID analysis provides only quantitative data. The coupling of gas chromatography with mass spectrometry is a powerful analytical tool that provides not only quantitative data but also qualitative data on the structure of substances. When quantified by GC-MS, the detector oversaturation is a problem as it is a highly sensitive detector (at ppb level). One way to avoid oversaturation of the detector is to significantly dilute the solutions, which causes a decrease in the sensitivity of the method. Another approach to bypass detector saturation is to interrupt detection during solvent elution. For quantification of the major components of solutions, only the first method of bypassing detector saturation can be applied, but it is a labor-intensive process that increases the measurement uncertainty. The interruption of detection during solvent elution is not applicable for the purpose of quantifying major components, so a new approach of quantifying major components of solutions using M+1 ions was proposed and...
Quantification of skin ceramides in patients after oncological treatment
Voláková, Eliška ; Opálka, Lukáš (advisor) ; Roh, Jaroslav (referee)
Charles University, Faculty of pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Candidate: Eliška Voláková Supervisor: PharmDr. Lukáš Opálka, Ph.D. Title of diploma thesis: Quantification of skin ceramides in patients after oncological treatment Ceramides are one of the three basic lipid components present in the stratum corneum of human skin. Alterations in the ratio of individual ceramides are associated with disruption of skin barrier function. Such changes have been observed not only in skin diseases of the non-cancerous type, but also as a consequence of cancer. The main aim of the present study was to investigate the difference in the representation of skin ceramides in the stratum corneum of healthy patients and patients after cancer. Samples were collected from five groups of patients, four of which represented cancer patients with different types of treatment: tumor resection, chemotherapy, radiation or a combination of chemotherapy and radiation. The remaining fifth group consisted of control samples from volunteers without a diagnosis of cancer. Samples were obtained by tape-stripping from an identical site on patient forearm, followed by protein determination. Cancer patient samples were compared with control samples in terms of different water loss through the...
Collective biography of Czechoslovak historiography of year 1934
Sixta, Václav ; Štaif, Jiří (advisor) ; Lomíček, Jan (referee)
This thesis deals with an analysis of symbolic representation of Czechoslovak historiography to year 1934. Its source is primary the Culture Directory from the year 1934, respectively the kvantification of its informations. This informations or profiles are analyzed through categories of position in hieararchy in historography, nationality, lokalization and specialization. According this categories we can see many different ways of creating symbolic representation in our set of historians. The phenomene of change in time and trends we can see by using category of generation, defined objectively every ten years according the date of birth. Thanks variability of categories we can see the plurality of ways of creating symbolic representation. For exact analysis of symbolic representation we use a concept of "field of representations" where the representations make a really exactly defined units. Their complicated struktures create a symbolic representation of whole czechoslovac historiography. By using a kvantification we can see the facts, which are by other method unachievable.
Numerical model for the origin of magmatic textures and its application to the Fichtelgebirge/Smrčiny granite batholith
Špillar, Václav ; Dolejš, David (advisor) ; Ježek, Josef (referee) ; Žák, Jiří (referee)
Magmatic processes are major agents responsible for the formation and differentiation of the Earth's crust. In contrast to extensive efforts to improve understanding and utility of igneous geochemistry, physical processes of magma differentiation and solidification remain largely unclear. Large variability of igneous textures provides record of these processes and intensive parameters governing the crystallization. In this thesis, we develop quantitative methods, which allow us to better interpret igneous textures in the framework of physics of solidification. We have developed a new three-dimensional model of crystallization from one- component melt driven by homogeneous and heterogeneous nucleation and crystal growth. The predicted textures are quantitatively characterized by crystal size distributions, spatial distribution functions and parameters representing grain contact relationships. The model employs high resolution in a large volume simulation domain in order to produce statistically stable results. Our simulations, performed for various functional forms of nucleation and growth rates with respect to time, imply that (i) crystals are ordered (anti-clustered) on short length scales. This reflects that other crystals already have a finite size at the time of nucleation of younger crystal,...
Polyethylene wear particles around joint replacements - their properties, distribution and possible mechanism of their adverse biological effects
Zolotarevová, Eva ; Gallo, Jiří (advisor) ; Rauch, Pavel (referee) ; Horák, Zdeněk (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE DEPARTMENT OF BIOCHEMISTRY PRAGUE 2010 Supervisor: Doc. MUDr. Jiří Gallo, PhD. Supervisor-consultant: Prof. RNDr. Gustav Entlicher, CSc. Eva Zolotarevová Summary of PhD Thesis POLYETHYLENE WEAR PARTICLES AROUND TOTAL JOINT REPLACEMENTS - THEIR PROPERTIES, DISTRIBUTION AND POSSIBLE MECHANISM OF THEIR ADVERSE BIOLOGICAL EFFECTS PRAGUE 2010 The research project was supported by the Grant project of National research program II. (no. 2B06096) of the Czech Ministry of Education, Youth and Sports named "Observation and minimization of UHMWPE wear in joint replacements". Front-page picture: Polyethylene wear particle isolated from granuloma tissue surrounding total hip replacement; Electron microscope microphotograph; particle size app. 90 x 80 µm; retouched Eva Zolotarevová Introduction Introduction For many people all over the world a replacement with an implant of irreversibly damaged joint is often the only way how to come back to normal life without pain and mobility limitation. Nowadays, greater and greater requirements are asked of quality of all replacement components, especially in terms of quality of used materials. Biomechanical properties of hip and knee replacements have been already solved. The most often used materials for manufacturing joint...
Quantification of procalcitonin in human serum by affinity surfaces and mass spectrometry
Dvořák, Josef ; Pompach, Petr (advisor) ; Kozlík, Petr (referee)
Sepsis is a worldwide health condition. It is caused by disproportionatly large immunity system response for patogene presence. Fast and accurate diagnosis of sepsis can make difference between life and death. For clinical diagnosis of sepsis is used serum protein procalcitonin (PCT) as biomarker. Procalcitonin concentration level in patient bloodstream increases up to thousand times in short time period. Severity of sepsis can be determined by correlation with its concentration in bloodstream. To determine PCT level in patient bloodstream a broad variety of specialized instrument is used. All methods have same principle of measurement - PCT-antibody interaction. Procalcitonin level is then quantified by calibration curve method. During these measurements non-specific protein-antibody interactions can occur and distort the quantification of PCT level. Mass spectrometry due to its properties comes into consideration as an alternative method, that can be used for PCT determination. Aim of this diploma thesis was in situ enrichment of PCT on surface modified affinity carriers with immobilized antibody against PCT. These carriers are compatible with matrix assisted laser desorption/ionization time of flight mass spectrometry. Mass spectrometry provides mass spectrum, where PCT and other signals...

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