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Three-dimensional Resolution (three-dimensional + resolution)
Selected AbstractsElectron Tomography in Plant Cell BiologyJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2007Thomas J. Haas Abstract This review focuses on the contribution of electron tomography-based techniques to our understanding of cellular processes in plant cells. Electron microscopy techniques have evolved to provide better three-dimensional resolution and improved preservation of the subcellular components. In particular, the combination of cryofixation/freeze substitution and electron tomography have allowed plant cell biologists to image organelles and macromolecular complexes in their native cellular context with unprecedented three-dimensional resolution (4,7 nm). Until now, electron tomography has been applied in plant cell biology for the study of cytokinesis, Golgi structure and trafficking, formation of plant endosome/prevacuolar compartments, and organization of photosynthetic membranes. We discuss in this review the new insights that these tomographic studies have brought to the plant biology field. [source] CARS microscopy of lipid stores in yeast: the impact of nutritional state and genetic backgroundJOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2009Christian Brackmann Abstract We have developed a protocol for sub-micrometer resolved and chemically specific imaging of lipid storage in vivo employing coherent anti-Stokes Raman scattering (CARS) microscopy of one of the most important model organisms Saccharomyces cerevisiae,the yeast cell. By probing the carbon,hydrogen vibration using the nonlinear process of CARS, lipid droplets in the yeast cells clearly appear, as confirmed by comparative studies on relevant labeled organelles using two-photon fluorescence microscopy. From the images, unique quantitative data can be deduced with high three-dimensional resolution, such as the volume, shape, number, and intracellular location of the neutral lipid stores. We exemplify the strength and usability of the method for two cases: the impact on lipid storage of the nutritional condition (starvation and type of carbon source available) as well as of genetic modification of two fundamental metabolic regulation pathways involving carbohydrate and lipid storage (BCY1 and DGA1, LRO1, ARE1/2 deletions), respectively. While the impact of carbon source on the total cellular lipid volume was minimal, long-term starvation induces a significant accumulation of lipid droplets. We also confirm that the lipid-storage-deficient mutant is indeed unable to synthesize lipid droplets, and that the inability of the bcy1 -mutant to store carbohydrates is compensated by a two-fold increase in stored neutral lipids. We note that there is a significant cell-to-cell variability in neutral lipid storage in general, i.e. that there is a correspondence to the noise found for gene expression also in lipidomics. Copyright © 2009 John Wiley & Sons, Ltd. [source] Evaluation of the improved three-dimensional resolution of a synchrotron radiation computed tomograph using a micro-fabricated test patternJOURNAL OF SYNCHROTRON RADIATION, Issue 6 2008Ryuta Mizutani A micro test pattern prepared by focused ion beam milling was used to evaluate the three-dimensional resolution of a microtomograph at the BL20B2 beamline of SPring-8. The resolutions along the direction within the tomographic slice plane and perpendicular to it were determined from the modulation transfer functions. The through-plane resolution perpendicular to the tomographic slice was evaluated to be 8,µm, which corresponds to the spatial resolution of two-dimensional radiographs. In contrast, the in-plane resolution within the slice was evaluated to be 12,µm. Real-space interpolation was performed prior to the tomographic reconstruction, giving an improved in-plane resolution of 8.5,µm. However, the 8,µm pitch pattern was resolved in the interpolated slice image. To reflect this result, another resolution measure from the peak-to-valley difference plot was introduced. This resolution measure gave resolution limits of 7.4,µm for the in-plane direction and 6.1,µm for the through-plane direction. The three-dimensional test pattern along with the interpolated reconstruction enables the quantitative evaluation of the spatial resolution of microtomographs. [source] | ||||||||||