This thesis deals with freezy sublimation in cryoattachement Gatan Alto 2500 connected to scanning electron microscope (SEM) JEOL JSM-7401F. The thesis is devided into the theoretical and practical parts. In the theoretical part I focus mainly on physical qualities of water and on problematics of freezy-drying. I also describe qualities of subsidiary substances which are being used when working with cryotechnology. I briefly describe technology used: cryoattachement Alto 2500 and SEM JSM-7401F. In the practical part I deal with the description of the method that I have developed in order to measure weight decrease of frozen specimen owning to its sublimation in vacuum. I provide measurement results of the sublimation of these substances: demineralized water, Dextran, glycerol and phosphate buffer saline.

Abstract Increased amounts of epicuticular waxes and UV-absorbing compounds, such as flavonoids, and smaller leaf/needle surface area are plant defence mechanisms against UV-B radiation. The response of the needle epicuticular waxes of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies Karst.) seedlings to increased UV-B were investigated in short-term and long-term greenhouse experiments. In a more realistic long-term field experiment with mature Scots pines, the methanol-extractable UV-absorbing compounds were also analysed. Some significant changes were observed in the wax tube distribution (WTD, %) and the amount of waxes in Norway spruce seedlings in the short-term Belgian greenhouse experiment (UV-BBE 0, 11.3 and 22.6 kJ m-2 d-1), but no changes were detected in Scots pine seedlings. No changes in waxes were observed in the long-term Finnish greenhouse experiment (UV-BBE 0, 2.2–6.6 and 5.6–16.8 kJ m-2 d-1), where both the Norway spruce and the Scots pine seedlings seemed to respond by having smaller needle surface areas. A field experiment (UV-BBE 0.5–2.4 kJ m-2 d-1 and 0.7–5.1 kJ m-2 d-1) with mature Scots pines revealed no significant changes in WTD during the three growing seasons or the amount of waxes during the third growing season. In the long-term field experiment the amount of UV-absorbing compounds varied significantly between seasons and/or needle age classes. Elevated amounts of these compounds were already observed in the three-day-old needles and also in the oldest (c + 2) needles when the waxes were still undeveloped or already somewhateroded. No significant differences in the amount of UV-absorbing compounds were observed between the treatments during the first and second growing seasons. During the third growing season, needles of all ages contained significantly or slightly less UV-absorbing compounds in supplemental UV-B than in the ambient treatment, possibly due to cumulative effects of UV-B in already inhibited pigment synthesis. This suggests that these defence mechanisms are not efficient enough to prevent the UV-B-induced damage in the long term.

The purpose of this diploma thesis is to research and compare available wireless communication technologies (frequency, modulation type, transmission speed and consumption). Describe transmission electron microscopes theory and deduce the most sensitive microscope parts to high frequency distortion. Investigate effect of wireless technology on CE standards and come up with, perform and evaluate the influence measurement of chosen technologies on base parameters of transmission electron microscope.

This master´s thesis deals with calibration and determination of uncertainties of measurement for focus variation microscope Alicona Infinite Focus G4. Together with calibration, a measurement of chosen parameters with calculation of measurement uncertainties of a component was realised. The thesis also describes the whole calibration process and terminology used in calibration, as well as the calibrated instrument, it´s parameters and usage in practice. The measurements were realized on premises of Intemac Solutions s.r.o. Obtained data were than processed using MS Excel, Gwyddion and TalyMap software. At the end of the thesis, practical recommendations are formulated.

This thesis is involved in image processing of medical data and its implementation using Java programming language. The main contribution of this thesis is creation of algorithms for feature extraction from 3D data and subsequent verification of the results for the issue of imagining 3D brain data, and creation of image filters and their implementation in the program RapidMiner. Consequently, the segmentation process is created at the 2D and 3D level, and output of 3D level segmentation are segmented brain structures. Furthermore, segmentation algorithms were compared on the basis of the final form of segmented structures and this approach was compared with other works.

This thesis focuses on the study of the life of a fluorescent dye. It also examines changes in its emission spectrum determined with the aid of development of fluorescence intensity over the long term sensing in several kinds if of cella. The general part of the thesis with the issues of confocal microscopy, fluorescent radiation and maks. Furthermorer, an analysis of methods for measuring fluorescence lifetime is done. In the thesis there is elaborated a description of the program, whitch was designed for the analysis of the collected output of the used confocal microscope. Sebsequently, the results are evaluated.

This diploma thesis deals with design, implementation and testing of fluorescence microscope intended for carbon nanotubes spectroscopy. Theory of fluorescence resulting from solid state physics and atomic structure of nanotubes is briefly discussed. The basic idea, optical scheme and optical elements used in the fluorescence microscope are described based on requirements resulting from the theory. The thesis mentions the sample preparation procedure and measurements of its optical activity as well. Realized microscope is usable for fluorescence measurements within the supposed range of wavelengths as was proved by testing.

L’avènement de la microscopie STED (Stimulated Emission Depletion) a bouleversé le domaine desneurosciences du au fait que beaucoup de structures neuronale, tels que les épines dendritiques, lesaxones ou les processus astrocytaires, ne peuvent pas être correctement résolu en microscopiephotonique classique. La microscopie 2-photon est une technique d’imagerie photonique très largement utilisée dans le domaine des neurosciences car elle permet d’imager les événements dynamique en profondeur dans le tissu cérébral, offrant un excellent sectionnement optique et une meilleure profondeur de pénétration. Cependant, la résolution spatiale de cette approche est limitée autour de 0.5 μm, la rendant inappropriée pour étudier les détails morphologiques des neurones et synapses. Le but de mon travail de thèse était à A) développer un microscope qui permet d'améliorer l'imagerie 2-photon en la combinant avec la microscopie STED et B) démontrer son potentiel pour l'imagerie à l'échelle nanométrique de processus neuronaux dynamiques dans des tranches de cerveau aigus et in vivo. Le nouveau microscope permet d'obtenir une résolution spatiale latérale de ~ 50 nm à des profondeurs d'imagerie de ~ 50 μm dans du tissu cérébral vivant. Il fonctionne avec des fluorophores verts, y compris les protéines fluorescentes communes telles que la GFP et YFP, offrant le contraste de deux couleurs basé sur la détection spectrale et linéaire ‘unmixing’. S’agissant d’un microscope droit, utilisant un objectif à immersion ayant une grande distance de travail, nous avons pu incorporer des techniques électrophysiologiques comme patch-clamp et ajouter une plateforme pour l'imagerie in vivo. J’ai utilise ce nouveau microscope pour imager des processus neuronaux fins et leur dynamique à l’échelle nanométrique dans différent types de préparations et des régions différentes du cerveau. J’ai pu révéler des nouvelles caractéristiques morphologique des dendrites et épines. En outre, j'ai exploré différentes stratégies de marquage pour pouvoir utiliser la microscopie STED pour imager le trafic des protéines et de leur dynamique à l'échelle nanométrique dans des tranches de cerveau. / The advent of STED microscopy has created a lot of excitement in the field of neuroscience becausemany important neuronal structures, such as dendritic spines, axonal shafts or astroglial processes,cannot be properly resolved by regular light microscopy techniques. Two-photon fluorescence microscopy is a widely used imaging technique in neuroscience because it permits imaging dynamic events deep inside light-scattering brain tissue, providing high optical sectioning and depth penetration. However, the spatial resolution of this approach is limited to around half a micron, and hence is inadequate for revealing many morphological details of neurons and synapses. The aim of my PhD work was to A) develop a microscope that improves on two-photon imaging by combining it with STED microscopy and to B) demonstrate its potential for nanoscale imaging of dynamic neural processes in acute brain slices and in vivo. The new microscope achieves a lateral spatial resolution of ~50 nm at imaging depths of ~50 μm in living brain slices. It works with green fluorophores, including common fluorescent proteins like GFP and YFP, offering two-color contrast based on spectral detection and linear unmixing. Because of its upright design using a long working distance water-immersion objective, it was possible to incorporate electrophysiological techniques like patch-clamping or to add a stage for in vivo imaging. I have used the new microscope to image fine neural processes and their nanoscale dynamics in different experimental preparations and brain regions, revealing new and interesting morphological features of dendrites and spines. In addition, I have explored different labeling strategies to be able to use STED microscopy for visualizing protein trafficking and dynamics at the nanoscale in brain slices.

>Magister Scientiae - MSc / Pletmos Basin is a Mesozoic half graben located in the southern part of South Africa and has undergone numerous tectonic changes which involve alteration of structure and reworking of sediments. Clay diagenesis has become a more prominent factor affecting the quality of the tight shaly sandstone reservoirs in the southern Pletmos Basin. The present study focused on Block 11a as a primary area of interest .The tight sandstone reservoirs encountered in the four wells, viz. Ga-Q1, Ga- Q2, Ga-Z1 and Ga- E2 were studied using four different methods to incorporate and infer the overall diagenetic effect on the reservoirs, caused by materials of argillaceous origin. The methods adopted in the present research are formation evaluation using wireline logs and calibration of core data using Interactive Petrophysics software, thin section petrography, X-Ray Diffraction (XRD) and, Scanning Electron Microscope (SEM) along with Energy Dispersive X-Ray Spectroscopy (EDS). The availability of core samples were limited to wells Ga- Q1 and well Ga- Z1. Four reservoirs within the Cretaceous age were identified in each well and the best reservoirs were associated with facies B and D. / 2022-04-30

Objective: This study was conducted to compare the shear bond strengths, patterns of bond failure and enamel surfaces after debonding two ceramic brackets (ClearVu and Radiance Plus) and one standard metal bracket (Mini Uni-Twin). Background: Ceramic brackets are an esthetic alternative to metal brackets. The mean shear bond strength of ceramic brackets is significantly greater than for metal brackets. Excessive bond strength can result in pain upon debonding, damage to the bracket or permanent damage to the enamel including flaking, cracks or tooth fracture. Numerous studies have evaluated techniques to reduce the risk of enamel damage when debonding ceramic brackets, including the use of debonding pliers. Debonding pliers produce a concentrated stress within the adhesive, resulting in cohesive failures within the resin or adhesive failures outside the resin. Methods: A total of 75 caries-free extracted human premolar teeth were randomly divided into 3 groups: ClearVu ceramic bracket (TP Orthodontics, LaPorte, IN), Radiance Plus ceramic bracket (American Orthodontics, Sheboygan, WI) and Mini Uni-Twin metal bracket (3M Unitek, Monrovia, CA). The Instron Universal Testing Machine Model 8841 with a customized jig with a bracket removing plier was used to debond the brackets. The teeth were microscopically evaluated to determine the location of bond failure. Selected teeth were evaluated with the scanning electron microscope to evaluate for enamel cracks and tear-outs. Results: A one-way ANOVA was created and no significant differences in shear bond strength were discovered between the three groups. Using a chi-square test of independence it was determined that the brackets all possessed a different ARI score. After examining the standardized residuals, we found that Radiance Plus Ceramic bracket and ClearVu Ceramic bracket were both likely to have favorable bond failure patterns, compared to the Mini Uni-Twin Metal bracket. Radiance Plus was most likely to debond at the bracket-adhesive surface, with a majority or all of the adhesive on the tooth after debond. Teeth with unfavorable bond failure patterns (ARI score of 0 or 1) were evaluated with the scanning electron microscope. 11% of the total teeth in the study had enamel damage, including cracks and tear-outs. 62.5% of these teeth were from the ClearVu ceramic bracket group. Conclusions: Our results show that both Radiance Plus ceramic bracket and ClearVu ceramic brackets are comparable to the gold standard metal bracket used in this study, the Mini Uni-Twin, in terms of shear bond strength. Radiance Plus ceramic bracket had the most favorable bond failure pattern, but shattered more during debonding. ClearVu ceramic bracket had the most enamel damage when evaluated with the scanning electron microscope. American Orthodontics’ Radiance Plus Ceramic bracket is the recommended bracket of those studied.