المؤلفون: Anita Razavi, Isabelle Henn, Almuth Sax, Peter Quirmbach

المصدر: International Journal of Ceramic Engineering & Science, Vol 6, Iss 3, Pp n/a-n/a (2024)

مصطلحات موضوعية: X‐ray computed tomography, refractories, microstructure, Clay industries. Ceramics. Glass, TP785-869

الوصف: Abstract X‐ray computed tomography (XRT) is a three‐dimensional (3D), non‐destructive, and reproducible investigation method capable of visualizing and examining internal and external structures of components independent of the material and geometry. In this work, XRT with its unique abilities complements conventionally utilized examination methods for the investigation of microstructure weakening induced by hydrogen corrosion and furthermore provides a new approach to corrosion research. The motivation for this is the current inevitable transformation to hydrogen‐based steel production. Refractories of the system Al2O3‐SiO2 are significant as lining materials. Two exemplary material types A and B, which differ mainly in their Al2O3:SiO2 ratio, are examined here using XRT. Identical samples of the two materials are measured, analyzed, and then compared before and after the hydrogen attack. In this context, hydrogen corrosion‐induced porosity and its spatial distribution and morphology are investigated. The results show that sample B has a higher resistance to hydrogen‐induced attack than sample A. Furthermore, the 3D representation revealed a differential porosity increase within the microstructure.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2578-3270Test

الوصول الحر: https://doaj.org/article/ac0739056c124592a53a8e68412a2e74Test

المؤلفون: Chun‐Long Fu, Ze‐Bin Yang, Ping Li, Kang‐Fei Shan, Mei‐Kang Wu, Jie‐Ping Xu, Chi‐Jun Ma, Fang‐Hong Luo, Long Zhou, Ji‐Hong Sun, Fen‐Hua Zhao

المصدر: Cancer Medicine, Vol 12, Iss 18, Pp 18460-18469 (2023)

مصطلحات موضوعية: adenocarcinoma, deep learning, lung, prognosis, X‐ray computed tomography, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

الوصف: Abstract Background The surgical approach and prognosis for invasive adenocarcinoma (IAC) and minimally invasive adenocarcinoma (MIA) of the lung differ. However, they both manifest as identical ground‐glass nodules (GGNs) in computed tomography images, and no effective method exists to discriminate them. Methods We developed and validated a three‐dimensional (3D) deep transfer learning model to discriminate IAC from MIA based on CT images of GGNs. This model uses a 3D medical image pre‐training model (MedicalNet) and a fusion model to build a classification network. Transfer learning was utilized for end‐to‐end predictive modeling of the cohort data of the first center, and the cohort data of the other two centers were used as independent external validation data. This study included 999 lung GGN images of 921 patients pathologically diagnosed with IAC or MIA at three cohort centers. Results The predictive performance of the model was assessed using the area under the receiver operating characteristic curve (AUC). The model had high diagnostic efficacy for the training and validation groups (accuracy: 89%, sensitivity: 95%, specificity: 84%, and AUC: 95% in the training group; accuracy: 88%, sensitivity: 84%, specificity: 93%, and AUC: 92% in the internal validation group; accuracy: 83%, sensitivity: 83%, specificity: 83%, and AUC: 89% in one external validation group; accuracy: 78%, sensitivity: 80%, specificity: 77%, and AUC: 82% in the other external validation group). Conclusions Our 3D deep transfer learning model provides a noninvasive, low‐cost, rapid, and reproducible method for preoperative prediction of IAC and MIA in lung cancer patients with GGNs. It can help clinicians to choose the optimal surgical strategy and improve the prognosis of patients.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-7634Test

الوصول الحر: https://doaj.org/article/3a2d139c597a40f2824da82f1ce9d91bTest

المؤلفون: Y. Akamatsu, I. Katayama, K. Okazaki, K. Michibayashi

المصدر: Geochemistry, Geophysics, Geosystems, Vol 24, Iss 6, Pp n/a-n/a (2023)

مصطلحات موضوعية: permeability, oceanic crust, hydrothermal circulation, X‐ray computed tomography, image processing, Oman Drilling Project, Geophysics. Cosmic physics, QC801-809, Geology, QE1-996.5

الوصف: Abstract To assess the paleo‐permeability structure of oceanic crust, we used 3‐D X‐ray Computed Tomography (XCT) images to quantify the distribution and geometry of mineral veins in core samples from Oman Drilling Project Holes GT1A, GT2A, and GT3A, which correspond to the upper to lower crustal sections of the Samail ophiolite. We developed a new method that automatically detects veins in the XCT core images based on iterative adaption of the two‐step Hough transform combined with multiscale Hessian filtering for identifying an elongate structure. Application of the developed method allowed us to identify the geometry and Computed Tomography number of more than 1500 veins with millimeter‐scale apertures in core sections with a total length of ∼1,200 m. High‐CT (HCT) veins in the drilled cores can be related to relatively high‐temperature fluid circulation near the mid‐ocean ridge, whereas Low‐CT (LCT) veins can be related to subsequent low‐temperature fluid circulation. Applying fracture fluid‐flow models to the geometric information for the detected veins, we found that the HCT and LCT vein systems both yielded bulk permeability of 10−13–10−9 m2 for each hole. This indicates that millimeter‐wide fractures can control crustal‐scale permeability, even in the lower oceanic crust. However, these vein systems show different depth dependencies and anisotropies of permeability, possibly reflecting the different spatial variations of high‐ and low‐temperature fluid circulation in oceanic crust.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1525-2027Test

الوصول الحر: https://doaj.org/article/46d2e18ca86f43afbf042623c3e56424Test

المؤلفون: Lucas, Maik, Santiago, J.P., Chen, J., Guber, A., Kravchenko, A.

المصدر: ISSN: 0028-646X.

مصطلحات موضوعية: carbon allocation, carbon sequestration, pore structure, root–soil contact, X-ray computed tomography

الوصف: Plant roots are the main supplier of carbon (C) to the soil, the largest terrestrial C reservoir. Soil pore structure drives root growth, yet how it affects belowground C inputs remains a critical knowledge gap.By combining X-ray computed tomography with 14C plant labelling, we identified root–soil contact as a previously unrecognised influence on belowground plant C allocations and on the fate of plant-derived C in the soil.Greater contact with the surrounding soil, when the growing root encounters a pore structure dominated by small (< 40 μm Ø) pores, results in strong rhizodeposition but in areas of high microbial activity. The root system of Rudbeckia hirta revealed high plasticity and thus maintained high root–soil contact. This led to greater C inputs across a wide range of soil pore structures. The root–soil contact Panicum virgatum, a promising bioenergy feedstock crop, was sensitive to the encountered structure. Pore structure built by a polyculture, for example, restored prairie, can be particularly effective in promoting lateral root growth and thus root–soil contact and associated C benefits.The findings suggest that the interaction of pore structure with roots is an important, previously unrecognised, stimulus of soil C gains.

وصف الملف: application/pdf

العلاقة: https://doi.org/10.48758/ufz.13657Test; https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=27513Test; https://dx.doi.org/10.1111/nph.19159Test

الإتاحة: https://doi.org/10.1111/nph.19159Test
https://doi.org/10.48758/ufz.13657Test
https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=27513Test

المؤلفون: Wei Li, Bobin Xing, Thomas R. Watkins, Yong Xia, Hsin Wang, Juner Zhu

المصدر: EcoMat, Vol 4, Iss 6, Pp n/a-n/a (2022)

مصطلحات موضوعية: finite element model, impedance behavior, internal short circuit, lithium‐ion battery, three‐point bending, X‐ray computed tomography, Renewable energy sources, TJ807-830, Environmental sciences, GE1-350

الوصف: Abstract The mechanically induced internal short circuit (ISC) is one of the major safety concerns of lithium‐ion batteries. Mechanical abuse tests are often performed to evaluate the integrity and safety of lithium‐ion batteries under mechanical loadings. Except for the widely explored compression‐dominated indentation tests, bending is another typical real‐world loading condition that is tension‐dominated. To investigate the mechanical damage and ISC behavior of batteries under bending, we carried out controlled three‐point bending tests in four progressive steps on prismatic battery cells with maximum deflections ranging from 38% to 76% of the cell thickness. None of the tested cells experienced an ISC. We then conducted 3D X‐ray computed tomography (CT) scanning on the bent cells after unloading. X‐ray CT images showed three out of the four tested cells have extensive cracking in the electrode layers at the bottom side (opposite to the loading head). This indicates that cracking does not necessarily lead to an ISC under bending. Electrochemical impedance spectroscopy was also measured on the bent cells and substantial changes were observed. Both the bulk resistance and charge‐transfer resistance increased significantly after bending, which could influence the battery performance and lifespan. We then developed a detailed finite (FE) element model to further investigate the mechanical deformation and failure mechanisms. The FE model successfully predicts the load–displacement response and reproduces the deformation patterns. The findings and the FE model developed in the present study provide useful insights and tools for the battery structure and crash safety design.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2567-3173Test

الوصول الحر: https://doaj.org/article/c06f2c77772e402d8da19bf5dad8872bTest

المؤلفون: Emily Brown, Kylie Dundas, Yolanda Surjan, Daniela Miller, Karen Lim, Miriam Boxer, Verity Ahern, George Papadatos, Vikneswary Batumalai, Jennifer Harvey, Debra Lee, Geoff P. Delaney, Lois Holloway

المصدر: Journal of Medical Radiation Sciences, Vol 68, Iss 2, Pp 157-166 (2021)

مصطلحات موضوعية: Magnetic resonance imaging, organs at risk, partial breast irradiation, patient positioning, X‐ray computed tomography, Medical physics. Medical radiology. Nuclear medicine, R895-920

الوصف: Abstract Introduction Conventionally computed tomography (CT) has been used to delineate target volumes in radiotherapy; however, magnetic resonance imaging (MRI) is being continually integrated into clinical practice; therefore, the investigation into targets derived from MRI is warranted. The purpose of this study was to evaluate the impact of imaging modality (MRI vs. CT) and patient positioning (supine vs. prone) on planning target volumes (PTVs) and organs at risk (OARs) for partial breast irradiation (PBI). Methods A retrospective data set, of 35 patients, was accessed where each patient had undergone MRI and CT imaging for tangential whole breast radiotherapy in both the supine and prone position. PTVs were defined from seroma cavity (SC) volumes delineated on each respective image, resulting in 4 PTVs per patient. PBI plans were generated with 6MV external beam radiotherapy (EBRT) using the TROG 06.02 protocol guidelines. A prescription of 38.5Gy in 10 fractions was used for all cases. The impact analysis of imaging modality and patient positioning included dose to PTVs, and OARs based on agreed criteria. Statistical analysis was conducted though Mann–Whitey U, Fisher’s exact and chi‐squared testing (P

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2051-3895Test; https://doaj.org/toc/2051-3909Test

الوصول الحر: https://doaj.org/article/3a59135dd3764e29a6ca2619091ce3aeTest

المؤلفون: Brok, Jesper Sune, Shelmerdine, Susan, Damsgaard, Frederikke, Smets, Anne, Irtan, Sabine, Swinson, Sophie, Hedayati, Venus, Jacob, Joseph, Nair, Arjun, Oostveen, Minou, Pritchard-Jones, Kathy, Olsen, Øystein

المصدر: Pediatric Blood & Cancer , Article e29759. (2022) (In press).

مصطلحات موضوعية: Wilms tumour, X-ray computed tomography, child, observer variation, secondary lung neoplasms

الوصف: OBJECTIVES: To investigate the extent to which observer variability of computed tomography (CT) lung nodule assessment may affect clinical treatment stratification in Wilms tumour (WT) patients, according to the recent Société Internationale d'Oncologie Pédiatrique Renal Tumour Study Group (SIOP-RTSG) UMBRELLA protocol. METHODS: I: CT thoraces of children with WT submitted for central review were used to estimate size distribution of lung metastases. II: Scans were selected for blinded review by five radiologists to determine intra- and inter-observer variability. They assessed identical scans on two occasions 6 months apart. III: Monte Carlo simulation (MCMC) was used to predict the clinical impact of observer variation when applying the UMBRELLA protocol size criteria. RESULTS: Lung nodules were found in 84 out of 360 (23%) children with WT. For 21 identified lung nodules, inter-observer limits of agreement (LOA) for the five readers were ±2.4 and ±1.4 mm (AP diameter), ±1.9 and ±1.8 mm (TS diameter) and ±2.0 and ±2.4 mm (LS diameter) at assessments 1 and 2. Intra-observer LOA across the three dimensions were ±1.5, ±2.2, ±3.5, ±3.1 and ±2.6 mm (readers 1-5). MCMC demonstrated that 17% of the patients with a 'true' nodule size of ≥3 mm will be scored as <3 mm, and 21% of the patients with a 'true' nodule size of <3 mm will be scored as being ≥3 mm. CONCLUSION: A significant intra-inter observer variation was found when measuring lung nodules on CT for patients with WT. This may have significant implications on treatment stratification, and thereby outcome, when applying a threshold of ≥3 mm for a lung nodule to dictate metastatic status.

وصف الملف: text

العلاقة: https://discovery.ucl.ac.uk/id/eprint/10149853/1/Pritchard-Jones_The%20clinical%20impact%20of%20observer%20variability%20in%20lung%20nodule%20classification%20in.pdfTest; https://discovery.ucl.ac.uk/id/eprint/10149853Test/

الإتاحة: https://discovery.ucl.ac.uk/id/eprint/10149853/1/Pritchard-Jones_The%20clinical%20impact%20of%20observer%20variability%20in%20lung%20nodule%20classification%20in.pdfTest
https://discovery.ucl.ac.uk/id/eprint/10149853Test/

المؤلفون: Carluccio, Anna Vittoria, David, Laure C., Claußen, Joelle, Sulley, Marco, Adeoti, Seun Raheemat, Abdulsalam, Toyin, Gerth, Stefan, Zeeman, Samuel C., Gisel, Andreas, Stavolone, Livia

المصدر: Plant, Cell & Environment, 45 (6)

مصطلحات موضوعية: Manioca, Rhizogenesis, Root bulking, Root development, X-ray computed tomography, Cassava, Storage roots

الوصف: Despite the importance of storage root (SR) organs for cassava and the other root crops yield, their developmental origin is poorly understood. Here we use multiple approaches to shed light on the initial stages of root development demonstrating that SR and fibrous roots (FR) follow different rhizogenic processes. Transcriptome analysis carried out on roots collected before, during, and after root bulking, highlighted early and specific activation of a number of functions essential for root swelling and identified root-specific genes able to effectively discriminate emerging FR and SR. Starch and sugars start to accumulate at higher rate in SR before they swell but only after parenchyma tissue has been produced. Finally, using non-destructive computed tomography measurements, we show that SR (but not FR) contain, since their emergence from the stem, an inner channel structure in continuity with the stem secondary xylem, indicating that SR derive from a distinct rhizogenic process compared with FR. ; ISSN:0140-7791 ; ISSN:1365-3040

وصف الملف: application/application/pdf

العلاقة: info:eu-repo/semantics/altIdentifier/wos/000775770100001; http://hdl.handle.net/20.500.11850/539354Test

الإتاحة: https://doi.org/20.500.11850/539354Test
https://doi.org/10.3929/ethz-b-000539354Test
https://doi.org/10.1111/pce.14300Test
https://hdl.handle.net/20.500.11850/539354Test

المؤلفون: Matthew J. Wilson, Marc Fradera‐Soler, Richard Summers, Craig J. Sturrock, Andrew J. Fleming

المصدر: Plant Direct, Vol 5, Iss 4, Pp n/a-n/a (2021)

مصطلحات موضوعية: cell geometry, mesophyll, ploidy, water‐use efficiency, wheat (Triticum aestivum), X‐ray Computed Tomography, Botany, QK1-989

الوصف: Abstract Leaf function is influenced by leaf structure, which is itself related not only to the spatial arrangement of constituent mesophyll cells, but also their size and shape. In this study, we used confocal microscopy to image leaves of Triticum genotypes varying in ploidy level to extract 3D information on individual mesophyll cell size and geometry. Combined with X‐ray Computed Tomography and gas exchange analysis, the effect of changes in wheat mesophyll cell geometry upon leaf structure and function were investigated. Mesophyll cell size and shape were found to have changed during the course of wheat evolution. An unexpected linear relationship between mesophyll cell surface area and volume was discovered, suggesting anisotropic scaling of mesophyll cell geometry with increasing ploidy. Altered mesophyll cell size and shape were demonstrated to be associated with changes in mesophyll tissue architecture. Under experimental growth conditions, CO2 assimilation did not vary with ploidy, but stomatal conductance was lower in hexaploid plants, conferring a greater instantaneous water‐use efficiency. We propose that as wheat mesophyll cells have become larger with increased ploidy, this has been accompanied by changes in cell geometry and packing which limit water loss while maintaining carbon assimilation.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2475-4455Test

الوصول الحر: https://doaj.org/article/ade861c0fdb542968fb9ed34f2b8cab3Test

المؤلفون: Jihang Sun, Chenghao Chen, Yun Peng, Yue Zhang, Hongwei Tian, Jie Yu, Jun Cao, Qi Zeng

المصدر: Pediatric Investigation, Vol 3, Iss 2, Pp 102-109 (2019)

مصطلحات موضوعية: Lung volume measurements, Magnetic resonance imaging, Thoracic wall, X‐ray computed tomography, Pediatrics, RJ1-570

الوصف: Abstract Importance Pectus excavatum (PE) is the most common thoracic wall deformity in children, we need a method which could be used to evaluate pulmonary functions and effects on development. Objective To evaluate the use of 3D T1‐weighted (3DT1) and mDIXON magnetic resonance imaging (MRI) sequences for measuring the thoracic parameters and morphology of children with PE, comparing the measurements with those made on computed tomography (CT). Methods This is a retrospective study of children with thoracic deformities who were hospitalized at the Department of Thoracic Surgery of the Heart Center, Beijing Children's Hospital, between June 2014 and June 2015. Chest CT was performed first, with the MRI scanning then being performed 0–3 days later. The mDIXON sequences were obtained in inspiratory and expiratory phases and the 3DT1 sequences were obtained during free breathing. Thoracic volume was measured using the acquired images. Results The lung volumes measured on mDIXON MRI and CT were highly correlated, with the Haller index not being significantly different between the two methods. Bland‐Altman analyses showed that lung, cardiac, and retrosternal parameters were similar between the two methods. Pulmonary parameters were higher with the end‐inspiratory phase mDIXON images than with the end‐expiratory phase images, as expected, while cardiac parameters were unaffected by the respiratory phase. Interpretation Thoracic volumes measured on mDIXON MRI in combination with held respiration could reflect lung volume functions and help in observing the movement functions of the lungs and heart. The method could be used instead of CT, avoiding subjecting the patient to potentially harmful radiation.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2574-2272Test

الوصول الحر: https://doaj.org/article/6c7ad69bc7044ae4ae191865acc8f62cTest