scholarly journals Applying micro-computed tomography (micro-CT) and Raman spectroscopy for non-invasive characterization of coating and coating pigments on ancient Chinese papers

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Tao Li ◽  
Chuang Liu ◽  
Dongmei Wang
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C. Tourolle né Betts ◽  
Gisela A. Kuhn ◽  
Erica Floreani ◽  
Malavika H. Nambiar ◽  
...  

AbstractThorough preclinical evaluation of functionalized biomaterials for treatment of large bone defects is essential prior to clinical application. Using in vivo micro-computed tomography (micro-CT) and mouse femoral defect models with different defect sizes, we were able to detect spatio-temporal healing patterns indicative of physiological and impaired healing in three defect sub-volumes and the adjacent cortex. The time-lapsed in vivo micro-CT-based approach was then applied to evaluate the bone regeneration potential of functionalized biomaterials using collagen and bone morphogenetic protein (BMP-2). Both collagen and BMP-2 treatment led to distinct changes in bone turnover in the different healing phases. Despite increased periosteal bone formation, 87.5% of the defects treated with collagen scaffolds resulted in non-unions. Additional BMP-2 application significantly accelerated the healing process and increased the union rate to 100%. This study further shows potential of time-lapsed in vivo micro-CT for capturing spatio-temporal deviations preceding non-union formation and how this can be prevented by application of functionalized biomaterials. This study therefore supports the application of longitudinal in vivo micro-CT for discrimination of normal and disturbed healing patterns and for the spatio-temporal characterization of the bone regeneration capacity of functionalized biomaterials.


2020 ◽  
Author(s):  
Jonathan Sittner ◽  
Jose R. A. Godinho ◽  
Axel D. Renno ◽  
Veerle Cnudde ◽  
Marijn Boone ◽  
...  

<p>Image based analytical tools in geoscience are indispensable for the characterization of minerals but most of them are 2D techniques, limited to the surface of a polished plane in a sample. X-ray micro computed tomography (micro-CT) is becoming a common analysis technique in geoscience and provides direct 3D information of the internal structure of a sample. A major drawback of micro-CT in the characterization of minerals, however, is the lack of chemical information. There have been different approaches to obtain chemical data using micro-CT but most of them are time consuming and difficult to adapt to regular use.</p><p>Therefore we introduce a potential new analytical tool: Laboratory-based Spectral X-ray Micro Computed Tomography (Sp-CT). Results from a spectral imaging detector prototype, installed inside a TESCAN CoreTOM micro-CT scanner, will be shown. This new analytical technique enables to obtain both high resolution structural and chemical information in 3D. With this information, the mineral distribution inside unbroken rocks and particles can be identified and quantified.</p><p>Based on the transmitted energy spectrum of a sample, main elements can be distinguished and minerals classified. It is also possible to quantify heavy elements within particles of complex composition and the measured sample volume is significantly larger compared to conventional analytical 2D techniques. Furthermore, Sp-CT is non-destructive and does not require sample preparation.</p><p>Sp-CT will open exciting new possibilities for mineral analysis. With this new technique, the 3D properties of the particles can now be measured and used for example in process mineralogy simulations. This is a major improvement to current simulations that predominantly use less representative 2D or bulk particle properties. Moreover, the Sp-CT could potentially be used as an alternative technique for regular characterization of ore deposits and processed ores since more representative volumes can be analyzed in a fast manner relative to existing techniques.</p><p>This research is part of the upscaling project “Resource Characterization: from 2D to 3D microscopy” and has received funding from European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation.</p>


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 178
Author(s):  
René Heyn ◽  
Abraham Rozendaal ◽  
Anton Du Plessis ◽  
Carene Mouton

The monetary value of gemstones is based on five variables: rarity, cut, weight, color and clarity. The latter refers to internal impurities and defects. Fashion may also dictate demand and price. To enhance some of these features and value, gemstones are treated. Disclosure or nondisclosure thereof has been controversial and affected consumer confidence. Most of these treatments are difficult to detect with the naked eye and accurately quantify with traditional optical and analytical methods. X-ray micro computed tomography (micro-CT or μCT) is proposed as a relatively low cost, physically non-destructive and complementary method to detect and quantify clarity enhancement and also to provide a unique 3D fingerprint of each gemstone. A collection of 14 cut colored gemstones was selected. Micro-CT scans allowed fracture detection, their distribution and calculation of filler volume as well as 3D mapping of inclusions, surface and internal imperfections and artificially induced modifications. As a result the method allows the construction of a digital twin. X-ray exposure could however induce unwanted color changes. This effect was minimized or eliminated by optimizing dosage and exposure time.


2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Alba-Tercedor ◽  
Wayne B. Hunter ◽  
Ignacio Alba-Alejandre

AbstractThe Asian citrus psyllid (ACP), Diaphorina citri, is a harmful pest of citrus trees that transmits Candidatus Liberibacter spp. which causes Huanglongbing (HLB) (citrus greening disease); this is considered to be the most serious bacterial disease of citrus plants. Here we detail an anatomical study of the external and internal anatomy (excluding the reproductive system) using micro-computed tomography (micro-CT). This is the first complete 3D micro-CT reconstruction of the anatomy of a psylloid insect and includes a 3D reconstruction of an adult feeding on a citrus leaf that can be used on mobile devices. Detailed rendered images and videos support first descriptions of coxal and scapus antennal glands and sexual differences in the internal anatomy (hindgut rectum, mesothoracic ganglion and brain). This represents a significant advance in our knowledge of ACP anatomy, and of psyllids in general. Together the images, videos and 3D model constitute a unique anatomical atlas and are useful tools for future research and as teaching aids.


2021 ◽  
Author(s):  
Eva Chatzinikolaou ◽  
Kleoniki Keklikoglou

Micro-computed tomography (micro-CT) is a high-resolution 3D-imaging technique which is now increasingly applied in biological studies focusing on taxonomy and functional morphology. The creation of virtual representations of specimens can increase availability of otherwise underexploited and inaccessible samples. This protocol aims to standardise micro-CT scanning procedures for embryos and juveniles of the marine gastropod species Hexaplex trunculus.


Polymer ◽  
2020 ◽  
Vol 202 ◽  
pp. 122628
Author(s):  
Cristofaro Timpano ◽  
Hossein Abdoli ◽  
Siu Ning Leung ◽  
Garrett W. Melenka

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