National Repository of Grey Literature 1,269 records found  previous11 - 20nextend  jump to record: Search took 0.07 seconds. 

Solar cell non-destructive analysis
Černý, Michal ; Škarvada, Pavel (referee) ; Macků, Robert (advisor)
This thesis briefly analyse contemporary situation of photovoltaic systems and their actual developemenet. It shows a typical properties of most produced up-to-date types. Decision point of this thesis consist in nondestructive analyse of monocristalic unijunction solar cells. It describes two main diagnostic aproaches. First – through the use of measuring of VA characteristics, second – through the use of measuring noise characteristics. With selected samples are performed experimental measurements and estabilished basic parameters. In case of drone analysis considerably attention is devoted to experimental equipment for automatized measuring of spectral power density. This experimental equipment is consequently used for measuring some samples where we can observe microplazmatic noise.

Optical Measurement of Electromechanical Characteristics of Heart Cells
Čmiel, Vratislav ; Križanová,, Olga (referee) ; Babula, Petr (referee) ; Provazník, Ivo (advisor)
Dissertation is focused on the application of optical measurement methods using techniques of optical microscopy and fluorescence microscopy in measurements of electromechanical characteristics of isolated cardiac cells and clusters of differentiated cardiomyocytes. The first proposed method uses a practical combination of fluorescence microscopy equipped with fluorescent fast and high-resolution camera and atomic force microscopy for simultaneous measurement of calcium transients and contraction of cardiomyocyte clusters. The signals obtained undergoes filtration, processing and analysis. Result function parameters obtained by analyzing signals after application of caffeine are evaluated by comparison with functional parameters obtained during the control measurement. The second proposed method is applied to the cardiomyocyte clusters for the purpose of cardiomyocyte contraction signals measurement. The signals obtained by optical methods are analyzed and compared with the reference signal obtained using atomic force microscopy. Optical measurement method of cell contractins based on detection of cell ends using adjusting of microscopy images by re-sharpening and fluorescence method for cardiomyocyte contractions measurements were designed to increase realiability in simultaneous measurement of cell contractions simultaneously with calcium transients in isolated cardiomyocytes experiments.

Neurogenetický potenciál kmenových buněk u myší
Slabá, Barbora ; Červený, Lukáš (referee) ; Štaud, František (advisor)
Neural stem cells (NSCs) are present in the mammalian adult nervous system and are found in two specific regions: the subventricular zone of the forebrain and the subgranular zone in the dentate gyrus of the hippocampus. NSCs undergo fate specification, maturation and functional integration before they can take part in neuronal circuits. Less is known about the mechanisms controlling these processes or the function of the newly born neurons in the adult brain. A large number of molecular and environmental factors can regulate various aspects of proliferation, maturation and differentiation of adult stem cells in adult nervous system. NSCs can give rise to three main types of neural cells: neurons, astrocytes and oligodendrocytes. It is suggested that astrocytes may play critical role in regulating neurogenesis in both the intact adult brain and after injury. Therefore, determining how astrocytes regulate adult neurogenesis at the molecular level is an essential step toward understanding the regulation of adult neurogenesis. To find out how genetic alteration of astrocytic intermediate filament will affect neural stem cells of postnatal mice, the neurosphere assay was performed in order to compare the proliferative and differentiation characteristics of neural stem/progenitor cells in GFAP-/- Vim-/-...


Single cell expression analysis of genes with potential mrna gradient in mouse oocytes
Dorosh, Andriy ; Margaryan, Hasmik ; Vodička, Martin ; Ergang, Peter ; Šídová, Monika ; Dvořáková-Hortová, Kateřina
In frogs, there are clearly visible differently pigmented animal and vegetal poles of the egg determined before fertilization and leading to asymmetrical divisions. Mammalian egg does not show any comparable differentiation and it has been generally accepted that even the individual blastomeres in 2-cell and 4-cell embryos are homogenous. However, recent findings suggest that those blastomeres display different gene expression patterns and might already possess some inclinations to specific cell lineages. We therefore raised a question, whether there could be any mRNA or protein gradients in pre-fertilization oocytes similar to a previously described amphibian egg one. In mammalian eggs, there is a membrane region that is poor in microvilli, cortical granules are absent beneath plasma membrane and sperm cells generally do not bind to this location. This microvilli free region also covers the egg nucleus, and cytoskeleton localization differs markedly to the rest of the cortical space, forming actin –myosin II cortical cap/ring and is considered as animal pole. The purpose of this study was to determine gene products that can be detected at single cell level using qPCR and display gradient like distribution in mature oocytes. We checked expression of 12 selected genes in a pool of 10 oocytes and single mature oocytes. Then, we analysed gene expression in fixed intact oocytes and those undergoing laser capture microdissection procedure (LCMD). Eventually, we have determined six candidate genes for the study of intracellular spatial gene expression in mature mammalian oocytes by subcellular qPCR and in situ hybridization.


Topography of signaling molecules on the plasma membrane in the course of mast cell activation
Lebduška, Pavel ; Dráber, Petr (advisor) ; Šebo, Peter (referee) ; Benada, Oldřich (referee) ; Tučková, Ludmila (referee)
presented technique of plasma membrane sheet preparation from nonadherent cells may facilitate research in this field. It must be, however, mentioned that a plastic view ofsignal transduction across the plasma membrane can be achieved only by combination of various mutually complementary approaches. Conclusions Three techniques of lsoladon of plasmr m€mbrane sh$ts from nonadherent BMMC mast cells have bmn developed. one of them, based on edsorption ofl€ukocýes to glass suďace, turned out to be very promlsing md provided many scientifrc datr(article E). Actlvation of RBL m9st c€l|s by FGRI raeptor dimerintion led to increme of Grb2 adaptor content in the Plasma membrane. Ilowever' by contřast to the case of receptor mu|t|merintion, this Grb2 did not sign|ficantly colocallz€ w|th FERI' and' by |mmuno|rbeling of membrane she€ts, distribution of FC5RI wrs not d|stinguishabl€ from the disfibution on nonact|vrted ce|ls (article A). BMMC, In contrast to RBL cells, after multimerization of FaRI did not form larger aggregat€s ofthis r€c€ptor thrn nonact|vat€d cells did. FGRI muldmer|ation led to lts int€rna|iation of comparable intensity rnd overa|l dynemics ln BMMC end RBL cel|s' but loce| redistribut|on of FaRI fundamentďly differed betwcn these two c€|| wes (article E). Established mode| oflrrg€ (8pproxim8t€|y...

Regulation of the expression of MHC class I molecules and other immunoactive molecules on tumor cells
Moravcová, Simona ; Vopálenský, Václav (referee) ; Reiniš, Milan (advisor)
4 Abstract Regulation of the expression of MHC class I molecules and other immunoactive molecules on tumor cells The aim of this master thesis project was to characterize the effects of IFNγ, TNFα and of the epigenetic agents 5-azacytidine (5AC) and 5-aza-2'-deoxycytidine (5AZAD) on the expression of molecules important for antigen presentation and modulation of the immune responses against tumors (MHC class I molecules and other immunoactive molecules CD54, CD80, B7-H1, B7-H2 and CD1d) on tumor cells. The experimental model used for this purpose were the HPV16-associated murine tumor cell lines, either MHC class I positive or negative. The goal was to determine the changes in surface expression of these molecules after treatment by FACS studies and also the expression at the mRNA level using qPCR. Expression of these proteins was also compared in the experiments in vitro on tumor cell lines and ex vivo on tumor cells explanted from animals. The most interesting result is the observation that 5AZAD increases the expression of B7-H1 which inhibits T cell mediated immune response and that 5AZAD and IFNγ act synergistically in the induction of the expression of MHC class I, CD54 and B7-H1 molecules. Klíčová slova: imunoeditace, protinádorová imunita, HVP16, MHC glykoproteiny I. třídy, B7-H1, IFNγ, TNFα,...

Cell culture-based model for the evaluation of adhesive properties of probiotic bacteria
Theodorou, Vasiliki ; Havlík, Jaroslav (advisor) ; Tauchen, Jan (referee)
Probiotic microorganisms, defined as living microorganisms which when administered in adequate amounts confer a health benefit to the host, and their adhesion and colonization of intestinal epithelium, are critical factors in maintaining probiotic efficacy. Polyphenols are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. In the last decade, there has been much interest in the health benefits of dietary plant polyphenols that arise from their potential ability to promote adhesion of probiotic bacteria to the human intestinal epithelium. The purpose of this study was to investigate the effect of four polyphenols: isoquercetrin, phloretin, procyanidin B2 and rutin on the adhesion ability of two potentially probiotic strains (Lactobacillus casei, Lactobacillus gasseri) to in vitro human intestinal epithelial model consisting of Caco-2 and mucus-secreting HT29-MTX co-culture. The adhesion of Lactobacillus casei after treating the co-culture cell lines with isoquercetrin, phloretin, and rutin was increased by 49.76, 72.97, 63.66 % respectively, whereas procyanidin B2 inhibited the adhesion 20.25% compared with the control sample. The adhesion of Lactobacillus gasseri after treatment of the co-culture with isoquercetrin, phloretin, procyanidin B2 and rutin was increased by 35.45, 31.28, 45.69, 25.01 % respectively compared with the control sample.

Mathematical modelling of cardiac cell contraction
Šlichta, J. ; Pásek, Michal
This paper contains a proposal of model of cardiac cell contraction, which describes the processes leading to interaction of contractile proteins actin and myosin. Based on model published by D. A. Smith [4] a J. Neumann [1] a five-state model was created that is described by means of nine nonlinear differential equations