scholarly journals Quantitative X-ray tomographic analysis reveals calcium precipitation in cataractogenesis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuxing Li ◽  
Dilworth Y. Parkinson ◽  
Jun Feng ◽  
Chun-hong Xia ◽  
Xiaohua Gong
Keyword(s):  
Light Scattering ◽  
Dense Matter ◽  
Nuclear Cataract ◽  
Micro Computed Tomography ◽  
Alizarin Red ◽  
Tomographic Images ◽  
X Ray ◽  
Age Related ◽  
Tomographic Analysis ◽  
Calcium Precipitation

AbstractCataracts, named for pathological light scattering in the lens, are known to be associated with increased large protein aggregates, disrupted protein phase separation, and/or osmotic imbalances in lens cells. We have applied synchrotron phase contrast X-ray micro-computed tomography to directly examine an age-related nuclear cataract model in Cx46 knockout (Cx46KO) mice. High-resolution 3D X-ray tomographic images reveal amorphous spots and strip-like dense matter precipitates in lens cores of all examined Cx46KO mice at different ages. The precipitates are predominantly accumulated in the anterior suture regions of lens cores, and they become longer and dense as mice age. Alizarin red staining data confirms the presence of calcium precipitates in lens cores of all Cx46KO mice. This study indicates that the spatial and temporal calcium precipitation is an age-related event associated with age-related nuclear cataract formation in Cx46KO mice, and further suggests that the loss of Cx46 promotes calcium precipitates in the lens core, which is a new mechanism that likely contributes to the pathological light scattering in this age-related cataract model.

Non-Destructive Assaying Gold Jewellery Using Dual-Energy Micro-Computed Tomography

2015 ◽  
Vol 73 (3) ◽  
Author(s):  
Jaafar Abdullah ◽  
Abibullah Samsudin ◽  
Nor Laili Omar ◽  
Hafizza Abdul Manan
Keyword(s):  
Computed Tomography ◽  
Matrix Effects ◽  
Visual Observation ◽  
Dual Energy ◽  
Micro Computed Tomography ◽  
Tomographic Images ◽  
X Ray ◽  
Challenging Tasks ◽  
Tomography Method ◽  
Non Destructive

Determining the fineness of gold jewelleries remains one of the most challenging tasks in gold trading. The existing technology of gold testing is inadequate, allowing gold counterfeiting worldwide. The most popular non-destructive method for analysis of gold jewelleries is X-ray fluorescence technique. However, the technique is limited to surface only and it is also greatly influenced by matrix effects. In this paper, dual-energy X-ray micro-computed tomography method was proposed to assay gold jewelleries. Experimental results demonstrated that grey values of reconstructed tomographic images in combination with advanced image analysis procedures could be used to detect fake jewelleries. Due to the uniqueness of X-ray absorption, the technique was also capable of identifying different materials in gold jewelleries. Further analysis on sectioned-earrings samples using X-ray diffraction techniques and visual observation confirmed all tomographic findings.  

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

Pathogenesis of Age-related Cataract: a systematic review of proteomic studies

2020 ◽  
Vol 17 ◽  
Author(s):  
Christina Karakosta ◽  
Argyrios Tzamalis ◽  
Michalis Aivaliotis ◽  
Ioannis Tsinopoulos
Keyword(s):  
Systematic Review ◽  
Oxidant Stress ◽  
Critical Role ◽  
Human Lens ◽  
Nuclear Cataract ◽  
Cataract Formation ◽  
Post Translational Modification ◽  
Ability To Act ◽  
Age Related

Background/Objective:: The aim of this systematic review is to identify all the available data on human lens proteomics with a critical role to age-related cataract formation in order to elucidate the physiopathology of the aging lens. Materials and Methods:: We searched on Medline and Cochrane databases. The search generated 328 manuscripts. We included nine original proteomic studies that investigated human cataractous lenses. Results:: Deamidation was the major age-related post-translational modification. There was a significant increase in the amount of αA-crystallin D-isoAsp58 present at all ages, while an increase in the extent of Trp oxidation was apparent in cataract lenses when compared to aged normal lenses. During aging, enzymes with oxidized cysteine at critical sites included GAPDH, glutathione synthase, aldehyde dehydrogenase, sorbitol dehydrogenase, and PARK7. Conclusion:: D-isoAsp in αA crystallin could be associated with the development of age-related cataract in human, by contributing to the denaturation of a crystallin, and decreasing its ability to act as a chaperone. Oxidation of Trp may be associated with nuclear cataract formation in human, while the role of oxidant stress in age-related cataract formation is dominant.

INVESTIGATION OF AUBRITES THROUGH INTEGRATION OF 3D MODAL MINERALOGY WITH X-RAY MICRO-COMPUTED TOMOGRAPHY AND GEOCHEMISTRY

2018 ◽  
Author(s):  
Zoë E. Wilbur ◽  
◽  
Arya Udry ◽  
Arya Udry ◽  
Daniel M. Coleff ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray

Investigation of material flow on inscribing a polymer surface grating probing X-ray and VIS light scattering

2002 ◽  
Vol 198-200 ◽  
pp. 107-111 ◽  
Author(s):  
O Henneberg ◽  
Th Geue ◽  
M Saphiannikova ◽  
U Pietsch ◽  
A Natansohn ◽  
...  
Keyword(s):  
Light Scattering ◽  
Material Flow ◽  
Polymer Surface ◽  
X Ray ◽  
Surface Grating

scholarly journals Reversible magnetism switching of iron oxide nanoparticle dispersions by controlled agglomeration

2021 ◽  
Author(s):  
Stephan Müssig ◽  
Björn Kuttich ◽  
Florian Fidler ◽  
Daniel Haddad ◽  
Susanne Wintzheimer ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Light Scattering ◽  
Superparamagnetic Iron Oxide ◽  
Iron Oxide Nanoparticle ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
X Ray Scattering ◽  
Nanoparticle Dispersions ◽  
Oxide Nanoparticle

The controlled agglomeration of superparamagnetic iron oxide nanoparticles (SPIONs) was used to rapidly switch their magnetic properties. Small-angle X-ray scattering (SAXS) and dynamic light scattering showed that tailored iron oxide...

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