Analysis of cobalt deposition in periprosthetic bone specimens by high-resolution synchroton XRF in undecalcified histological thin sections

Materialia ◽  
2019 ◽  
Vol 6 ◽  
pp. 100290 ◽  
Author(s):  
Michael Hahn ◽  
Günter Buzanich ◽  
Katharina Jähn ◽  
Uwe Reinholz ◽  
Martin Radtke
Author(s):  
Glen B. Haydon

High resolution electron microscopic study of negatively stained macromolecules and thin sections of tissue embedded in a variety of media are difficult to interpret because of the superimposed phase image granularity. Although all of the information concerning the biological structure of interest may be present in a defocused electron micrograph, the high contrast of large phase image granules produced by the substrate makes it impossible to distinguish the phase ‘points’ from discrete structures of the same dimensions. Theory predicts the findings; however, it does not allow an appreciation of the actual appearance of the image under various conditions. Therefore, though perhaps trivial, training of the cheapest computer produced by mass labor has been undertaken in order to learn to appreciate the factors which affect the appearance of the background in high resolution electron micrographs.


Author(s):  
M. H. Chen ◽  
C. Hiruki

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.


2018 ◽  
Vol 34 (1) ◽  
pp. 100-114 ◽  
Author(s):  
Magnus M. Haaland ◽  
Matthias Czechowski ◽  
Frank Carpentier ◽  
Mathieu Lejay ◽  
Bruno Vandermeulen

2021 ◽  
Author(s):  
Richard Wessels ◽  
Thijmen Kok ◽  
Hans van Melick ◽  
Martyn Drury

<p>Publishing research data in a Findable, Accessible, Interoperable, and Reusable (FAIR) manner is increasingly valued and nowadays often required by publishers and funders. Because experimental research data provide the backbone for scientific publications, it is important to publish this data as FAIRly as possible to enable reuse and citation of the data, thereby increasing the impact of research.</p><p>The structural geology group at Utrecht University is collaborating with the EarthCube-funded StraboSpot initiative to develop (meta)data schemas, templates and workflows, to support researchers in collecting and publishing petrological and microstructural data. This data will be made available in a FAIR manner through the EPOS (European Plate Observing System) data publication chain <span xml:lang="EN-GB"><span>(https://epos-msl.uu.nl/</span></span><span xml:lang="EN-GB"><span>)</span></span><span xml:lang="EN-GB"><span>.</span></span></p><p>The data workflow under development currently includes: a) collecting structural field (meta)data compliant with the StraboSpot protocols, b) creating thin sections oriented in three dimensions by applying a notch system (Tikoff et al., 2019), c) scanning and digitizing thin sections using a high-resolution scanner, d) automated mineralogy through EDS on a SEM, and e) high-resolution geochemistry using a microprobe. The purpose of this workflow is to be able to track geochemical and structural measurements and observations throughout the analytical process.</p><p>This workflow is applied to samples from the Cap de Creus region in northeast Spain. Located in the axial zone of the Pyrenees, the pre-Cambrian metasediments underwent HT-LP greenschist- to amphibolite-facies metamorphism, are intruded by pegmatitic bodies, and transected by greenschist-facies shear zones. Cap de Creus is a natural laboratory for studying the deformation history of the Pyrenees, and samples from the region are ideal to test and refine the data workflow. In particular, the geochemical data collected under this workflow is used as input for modelling the bulk rock composition using Perple_X.    </p><p>In the near future the workflow will be complimented by adding unique identifiers to the collected samples using IGSN (International Geo Sample Number), and by incorporating a StraboSpot-developed application for microscopy-based image correlation. This workflow will be refined and included in the broader correlative microscopy workflow that will be applied in the upcoming EXCITE project, an H2020-funded European collaboration of electron and x-ray microscopy facilities and researchers aimed at structural and chemical imaging of earth materials. </p>


1996 ◽  
Vol 183 (1) ◽  
pp. 295-298 ◽  
Author(s):  
Jun-Mo Yang ◽  
Daisuke Shindo ◽  
Grace E. Dirige ◽  
Atsushi Muramatsu ◽  
Tadao Sugimoto

2020 ◽  
pp. jgs2020-104
Author(s):  
Liene Spruženiece ◽  
Michael Späth ◽  
Janos L. Urai ◽  
Estibalitz Ukar ◽  
Michael Selzer ◽  
...  

Liassic limestones on the coast of Somerset in the UK contain dense arrays of calcite microveins with a common, but poorly understood microstructure, characterized by laterally wide crystals that form bridges across the vein. We investigated the mechanisms of formation and evolution of these ‘wide-blocky’ vein microstructures using a combination of high-resolution analytical methods, including virtual petrography, optical cathodoluminescence and scanning electron microscopy techniques (e.g. energy-dispersive X-ray spectrometry, back-scattered electron imaging, cathodoluminescence and electron back-scattered diffraction), laboratory experiments and multiphase field modelling. Our results indicate that the studied veins formed in open, fluid-filled fractures, each in a single opening and sealing episode. As shown by the optical and electron back-scattered diffraction images, the vein crystals grew epitaxially on grains of the wall rock and we hypothesize that their growth rates differed depending on whether the crystals were on a wall rock grain substrate that fractured intergranularly (slow growth rates) or transgranularly (rapid growth rates). Our multiphase field models support this hypothesis, showing that wide, blocky crystals only form where there are significant differences in the growth rate and are dependent on the type of seed grain. These results provide strong evidence for extreme growth competition, a process that we propose controls vein-filling in many micritic carbonate reservoirs, as well as demonstrate that the characteristics of the fracture wall can affect the filling processes in syntaxial veins.Supplementary material: The description and images of the studied thin sections are available at https://doi.org/10.6084/m9.figshare.c.5172371. High-resolution optical microscopy mosaics (under plane-polarized- and crossed polarized light) of the thin section collection in PetroScan file format are available on request from the authors.


2016 ◽  
Author(s):  
Steven Henkel ◽  
Dieter Pudlo ◽  
Frieder Enzmann ◽  
Viktor Reitenbach ◽  
Daniel Albrecht ◽  
...  

Abstract. An essential part of the collaborative research project H2STORE ("hydrogen to store"), which is founded by the German government, was a comparison of various analytical methods to characterize reservoir sandstones from different stratigraphic units. In this context Permian, Triassic and Tertiary reservoir sandstones were analysed. Rock core materials, provided by RWE Gasspeicher GmbH (Dortmund), GFD Suez E&P Deutschland GmbH (Lingen), E.ON Gas Storage GmbH (Essen) and RAG Rohöl-Aufsuchungs Aktiengesellschaft (Wien), was processed by different laboratory techniques; thin sections were prepared, rock fragments were crushed, cubes of 1 cm edge length and plugs of 5 cm in length were sawn from macroscopic homogenous cores. With this prepared sample material, polarized light microscopy and scanning electron microscopy – coupled with image analyses, specific surface area measurements (BET), He-porosity and N2-permeability measurements and high resolution micro-computer-tomography (µ-CT), which were used for numerical simulations were conducted. All these methods were applied to most of the same sample material, before and after static CO2 experiments under reservoir conditions. A major concern in comparing the results of these methods is an appraisal of the reliability of the given porosity, permeability and mineral specific reactive (inner) surface areas data. The CO2 experiments are modifying the petrophysical as well the mineralogical/geochemical rock properties. These changes are detectable by all applied analytical methods. Nevertheless, a major outcome of the high resolution µ-CT analyses and proceeded numerical data simulations results in quite similar data sets and data interpretations maintained by the different standard methods; even regarding only CT-single scan of the rock samples. Moreover, this technique is not only time saving, but also none destructive. This is an important point, if only minor sample material is available and a detailed comparison before and after the experimental tests on micro meter, pore scale of specific rock features is envisaged.


2020 ◽  
Author(s):  
Xueru Zhao ◽  
Sabine Wulf ◽  
Markus J. Schwab ◽  
Rik Tjallingii ◽  
Achim Brauer

<p>The high-resolution Monticchio (MON) sediment record has been demonstrated to be a key archive for reconstructing climate and environmental changes in the central Mediterranean for the last glacial-interglacial cycle. New sediment cores have been retrieved in April 2016 to investigate particularly the transition from the Last Glacial Maximum into the Holocene with a new high-resolution methodological approach. A floating varve chronology spanning ca. 8,000 years has been established by varve counting on thin sections using a petrographic microscope and layer thickness based sedimentation rate estimates for non- or poorly varved intervals. Varve counting is based on detailed seasonal deposition models of five different varve types. The resulting floating chronology consist of 66.6% individually counted varves and 33.4% interpolated years. The uncertainty estimate of the floating chronology has been determined by double counting and amounts to ±5.8%.</p><p>The floating chronology is anchored to an absolute chronology using the Agnano Pomici Principali tephra, dated at 11,999±52 cal yrs BP from paleosols overlying proximal tephra (Bronk Ramsey et al. 2015), is a suitable anchoring point to cross correlation. The resulting varve-based chronology has been compared with several other marker tephras dated elsewhere including the Soccavo 4 tephra (11,700±150 cal yrs BP), the Neapolitan Yellow Tuff (NYT; 14,194±172 cal yrs BP) and the Greenish tephra (19226±104 cal yrs BP). Further comparison with published (Hajdas et al. 1997) and new radiocarbon dates from different terrestrial macro remains are discussed in this paper. This study presents an independent chronology for the last glacial/interglacial transition for a comparison of MON data with high-resolution lake records western and central Europe.</p><p>References</p><p>Bronk Ramsey, C., P. G. Albert, S. P. E. Blockley, M. Hardiman, R. A. Housley, C. S. Lane, S. Lee, I. P. Matthews, V. C. Smith & J. J. Lowe (2015) Improved age estimates for key Late Quaternary European tephra horizons in the RESET lattice. Quaternary Science Reviews, 118<strong>,</strong> 18-32.</p><p>Hajdas, I., G. Bonani, B. Zolitschka, A. Brauer & J. Negendank (1997) 14C Ages of Terrestrial Macrofossils from Lago Grande Di Monticchio (Italy). Radiocarbon, 40<strong>,</strong> 803-807.</p>


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