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A novel approach imaging engorged ticks: Micro-CT scanning of Ixodes ricinus fed on blood enriched with gold nanoparticles
ONDRUŠ, Jaroslav
Micro-computed tomography (micro-CT) is an exceptional non-destructive imaging modality, which can be used to visualize both external and internal morphology of arthropods like ticks. The major micro-CT drawback is the soft tissues visualization, which require pre-examination contrasting steps. The commonly employed tick contrasting methods are drying and immersion in a solution containing a high-atomic number element, which both cause major deformation and shrinkage of examined specimens. The aim of this study was to develop a new tick contrasting approach to bypass these limitations. We show that adult Ixodes ricinus females engorged in vitro on blood enriched with gold nanoparticles with polyethylene glycol coating can be scanned with excellent contrast. By utilizing this technique based on the hematophagous nature of the ticks, we were able to observe midgut lumen, midgut epithelium and rectal sac in their natural state. In addition, we were able to precisely calculate the midgut volume.
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Three-dimensional characterization of polymer foams using X-ray dark-field imaging
Senck, S. ; Plank, B. ; Gusenbauer, C. ; Salaberger, D. ; Vavřík, Daniel ; Santer, W. ; Kastner, J.
Due to the low cost, the ease of processing, and excellent material properties, polymer foams are used in various applications, e.g. packaging, building and construction, furnitures and bedding, and the automotive and aerospace sector. The mechanical response of polymer foams is primarily influenced by density and morphology. While foam density can be determined with high precision, cell morphology is more difficult to determine since the size distribution of foam cells differs in three dimensions. However, using conventional methods, e.g. optical light microscopy or scanning electron microscopy, it is very difficult to obtain three-dimensional information and to differentiate between the strut system and cell walls. An alternative for the three-dimensional characterization of foam morphology is micro-computed tomography (XCT). But even non-destructive techniques like XCT are not able to characterize anisotropic foams if the thickness of single struts and cell walls is below the physcial resolution of the respective XCT system. In this contribution we therefore investigate different polymeric foam samples using a Talbot-Lau grating interferometer XCT (TLGI-XCT) system. We show that the obtained darkfield contrast images show a high contrast and a strong signal at struts and cell walls, facilitating the segmentation of foam cells in various examples.
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