Mitochondrien sind essentielle Organellen eukaryotischer Zellen. Sie erfüllen eine Vielzahl wichtiger Funktionen in den Zellen: neben ihrer herausragenden Bedeutung für die Energieproduktion haben sie eine zentrale Rolle im Stoffwechsel, der Ionenhomöostase, sowie beim Zelltod. Weiterhin sind Mitochondrien hochdynamische Organellen. Die Erscheinung des mitochondrialen Netzwerks wird durch die Vorgänge der Fusion und Teilung kontinuierlich verändert. Eine morphologische oder funktionale Heterogenität dieser Organellen wurde bereits in verschiedenen Zelltypen und innerhalb einzelner Zellen beobachtet. Über die Bedeutung dieser Beobachtungen gibt es jedoch nur Vermutungen. Es wird angenommen, dass sie die Folgen eines mitochondrialen Anpassungsmechanismus an unterschiedliche metabolische Anforderungen darstellen. Bislang ist wenig darüber bekannt, ob mitochondriale Proteine auch eine heterogene intrazelluläre Verteilung aufweisen. Um Informationen über die Lokalisation mitochondrialer Proteine zu erhalten, wird unter anderem die Fluoreszenzmikroskopie eingesetzt. Im Rahmen dieser Arbeit wurden sowohl Konfokal- als auch beugungsunbegrenzte STED-Mikroskopie in Kombination mit mathematischen Auswertealgorithmen verwendet, um mitochondriale Proteinverteilungen quantitativ innerhalb einzelner Säugerzellen zu analysieren. In dieser Arbeit wurde gezeigt, dass eine Vielzahl mitochondrialer Proteine, welche in verschiedenen mitochondrialen Subkompartimenten lokalisieren und unterschiedliche Funktionen erfüllen, eine heterogene Dichteverteilung in Form eines Gradienten, mit einer höheren Proteindichte in Zellkernnähe, innerhalb einzelner Zellen aufweist. Diese Gradientenverteilung ist zudem bereits direkt nach der Zellteilung in beiden Tochterzellen zu beobachten. Des Weiteren wurde gezeigt, dass die Hyperelongation von Mitochondrien eine Verringerung des Ausmaßes der Gradientenverteilung von Tom20 bewirkt. Außerdem wurde im Rahmen dieser Arbeit gezeigt, dass in Zellen, in denen die Mikrotubuli depolymerisiert vorliegen, das Ausmaß der intrazellulären Tom20-Gradientenverteilung deutlich verringert ist. Diese Beobachtung legt die Vermutung nahe, dass der Vorgang des mitochondrialen Transports einen entscheidenden Einfluss auf die heterogene Verteilung mitochondrialer Proteine hat. Somit wurde durch diese Arbeit das Verständnis der intrazellulären Heterogenität mitochondrialer Proteinverteilungen entscheidend verbessert. Durch die erhaltenen Ergebnisse kann festgestellt werden, dass viele mitochondriale Proteine eine heterogene Verteilung in Form eines intrazellulären Dichtegradienten aufweisen, die durch Vorgänge der mitochondrialen Dynamik (Teilung, Bewegung) kontrolliert wird.

Zugl.: Stuttgart, Univ., Diss., 2007.

Zugl.: Magdeburg, Univ., Diss., 2010

Techn. University, Diss., 2004--Darmstadt.

Techn. Universiẗat, Diss., 2004--Berlin.

Three aluminium alloys from AA3003 series modified by zirconium were pre- pared by twin-roll casting. The role of composition, heat treatment and deforma- tion by cold-rolling or equal channel angular pressing on evolution of microstruc- ture and mechanical properties were studied. High density of α-Al(Mn,Fe)Si pre- cipitates formed during annealing between 300 ◦ C and 500 ◦ C. Coherent Al3Zr particles precipitated during annealing at 450 ◦ C with slow heating rate. Recrys- tallization resistance of deformed alloys was enhanced by either Al3Zr precipitates formed before deformation or by α-Al(Mn,Fe)Si particles nucleating simultane- ously with recrystallization. 1

The aim of this thesis was to design new algorithms for processing image data from microscopes and demonstration of the possibilities of their use on standard samples (latex particles of different diameter). Results were used for the analysis of real objects inside the living mammalian cell. For the design of these algorithms was necessary to first understand how the image in the microscope is build, including a variety of lens aberrations. It was necessary to start with simulations of ideal case displaying one point (simulation PSF). Images of Airy discs in the plane of focus, or simulations using the ENZ theory. Available ENZ simulations provide only a few sections of different focal planes. It was necessary to adjust them to a usable form for generating a full 3D view. Using these algorithms, it was examined the behavior of the basic lens aberrations, and the behavior of two particles (objects) at different distances from each other. At the conclusion of these observations, it was necessary to redefine the terms Focus and resolution. Furthermore, the definitions have been introduced for discriminability and distinguishability of objects in an image. Thanks to the new definitions and new viewing (information entropy) to challenge the discriminability/distinguishability problem of objects in the image was possible to design and develop algorithms for image processing that enable to detect objects below the Abbe resolution condition using standard optical bright field microscopy. It has been found experimentally that the limiting factor for resolution using this method is the size and resolution of the camera chip. When using a chip with a higher density of points, we can achieve better results (detection of smaller objects) using the same algorithms.

The genome size of evolutionary polyploid, neopolyploid and hybrid sturgeons is well known for its high variability. Aim of this study was 1) to specify the genome size of polyploid and neopolyploid sturgeons using an analysis of 2-D and 3-D images of specifically stained cells nuclei, 2) to evaluate the samples of populations for cytogenetic analysis needs and thereafter, 3) to compare both methods and record the data either for next research or for negative selection from the broodstock. This test has been done at the laboratory of molecular, cellular and quantitative genetics, Faculty of Fisheries and Protection of Waters USB in Vodňany using all sturgeons spawners and using samples obtained from some foreign fish farms which cooperated with the faculty. The samples included A. ruthenus, A. baerii, A. stellatus, A. gueldenstaedtii and Huso huso, intentionally bred hybrids of A. gueldenstaedtii (8n) x A. baerii (12n), A. baerii (8n) x A. ruthenus (4n), A. gueldenstaedtii (8n) x A. baerii (10n) a A. gueldenstaedtii (8n) x A. ruthenus (4n). As methods have been chosen image cytometry and confocal microscopy which use image digitalization and subsequently its computer analysis. The genome size was measured from the size of specifically stained nuclei of erythrocytes in specimens sampled. Result of this study was measuring the genome size in sturgeons under study using different methods, recording the obtained data, description of spatial conformation changes of cell nucleus with increasing ploidy level and deduction of impact to their physiology and comparing the methods between each other. The conclusion is necessity of another sturgeons genome size determination , choice of the best methods for more effective search and research of non-standard individuals and subsequently an examination of their physiological differences.

The aim of this master thesis is to focus on a various methods of the conjugation of palladium nanoparticles of different shapes on the protein. The main point was to use both covalent and non-covalent conjugation of palladium nanoparticles on the protein and to use the functional conjugates to find out their stability in time.

The content of this study is focused on the influence of the structure of wood at microscopic and submicroscopic level on its mechanical properties. The wood cell wall consists of several layers, the dominant layer being layer S2, which occupies up to 80 % of the total thickness of the wood cell wall. Unique feature of this layer is that cellulose microfibrils placed in this layer are highly aligned and spirally wound around the cell axis. The inclination of these microfibrils is called microfibril angle (MFA) and is the key feature that affects mechanical properties of wood and its shrinkage. In theoretical part of this thesis methods for measuring microfibril angle are described. A method for measuring mechanical properties of the wood cell wall called nanoindentation is discussed in detail. In the practical part of this thesis, microfibril angle is measured by means of polarized light microscopy and mechanical properties of wood cell wall is determined by means of nanoindentation.