Section Scanning Research Articles

Characterization of Banana Crowns: Microscopic Observations and Macroscopic Cutting Experiments

Banana crowns’ intricate vascular systems facilitate nutrient transport for fruit growth and provide mechanical support. Analyzing vascular bundle morphology facilitates understanding of its influence on the banana de-handing process. In this study, we employed X-ray Computed Tomography (CT) scanning and microscopic observation of paraffin sections to characterize the morphological traits of the banana crown’s vascular tissue system and reconstructed its 3D vascular tissue system throughout the banana bunch. Based on the internal tissue characteristics and external morphology, the banana crown is categorized into three regions: the central stalk–crown transition region (CSCTR), the crown expansion region (CER), and the crown–finger transition region (CFTR). Cutting experiments indicated that variations in the cutting strength and specific cutting energy across positions within the banana bunch were insignificant but significantly distinct among the three regions. Specifically, the CER showed a 19.7% reduction in cutting strength and a 15.5% decrease in energy consumption compared to the other regions. This was due to the unique cross-distribution of fibers within the CER, which were primarily parallel to the cutting blade, significantly reducing cutting forces and energy consumption, making the CER the optimal region for cutting. The orientation of vascular bundles relative to the blade is key to optimizing plant cutting mechanics.

Quantitative characterization of granite failure intensity under dynamic disturbance from energy standpoint

Abstract Quantitative evaluation of rock dynamic disaster intensity is a challenging and difficult task in the field of earth science. In this article, the dynamic compression tests of granite under different impact velocities are carried out, and the energy evolution characteristics of the dynamic failure process of granite are analyzed. The dynamic fracture characteristics of granite were studied by using computed tomography and section scanning equipment. The results show that the energy dissipation and energy accumulation mechanism of granite under dynamic loading are fundamentally changed with the increase of impact disturbance strength, which leads to the transformation of the failure mode from the tension-type sheet crack under low-speed impact to the complex network crack coupled by tension and shear under high-speed impact. At the same time, the greater the impact velocity, the larger the macroscopic crack density, the more uneven the particle distribution on the fracture section, the greater the roughness, and the higher the rock mass fracture degree. In accordance with the results, the energy distribution ratio is proposed to quantitatively characterize the coupling effect of energy dissipation and energy accumulation in the dynamic failure process of granite and to reflect its dynamic failure intensity. The higher the energy distribution ratio, the stronger the energy coupling effect and the more intense the dynamic failure of the rock mass.

PSLBII-11 Predicting carcass chemical composition of crossbred bulls using Dual Energy X-Ray Absorptiometry (DXA) scanning of different carcass sections

PSLBII-11 Predicting carcass chemical composition of crossbred bulls using Dual Energy X-Ray Absorptiometry (DXA) scanning of different carcass sections

Histopathology imaging and clinical data including remission status in pediatric inflammatory bowel disease

The incidence of inflammatory bowel disease (IBD) is increasing annually. Children with IBD often suffer significant morbidity due to physical and emotional effects of the disease and treatment. Corticosteroids, often a component of therapy, carry undesirable side effects with long term use. Steroid-free remission has become a standard for care-quality improvement. Anticipating therapeutic outcomes is difficult, with treatments often leveraged in a trial-and-error fashion. Artificial intelligence (AI) has demonstrated success in medical imaging classification tasks. Predicting patients who will attain remission will help inform treatment decisions. The provided dataset comprises 951 tissue section scans (167 whole-slides) obtained from 18 pediatric IBD patients. Patient level structured data include IBD diagnosis, 12- and 52-week steroid use and name, and remission status. Each slide is labelled with biopsy site and normal or abnormal classification per the surgical pathology report. Each tissue section scan from an abnormal slide is further classified by an experienced pathologist. Researchers utilizing this dataset may select from the provided outcomes or add labels and annotations from their own institutions.

Imaging-based detection of anterior chamber inflammation: a comparative diagnostic accuracy study

PurposeWe investigated the impact of operator parameters on the diagnostic performance of danterior segment optical coherence tomography (AS-OCT) in anterior uveitis. DesignProspective comparative diagnostic analysis. MethodsSetting: Single site.Study Population: Children aged under 18 years with anterior uveitis, recruited consecutively.Observation Procedures: Index testing: Optovue RTVue80 AS-OCT using ‘low-volume’ (LV, horizontal and vertical cross-sections) and ‘high-volume’ (HV, 68 horizontal cross-sections) protocols. Reference testing: slit lamp examination with anterior chamber inflammation graded using standardisation of uveitis nomenclature (SUN).Main Outcome Measure: Index test performance metrics (sensitivity, specificity, likelihood ratios), utility for ‘ruling-in’ and ‘ruling-out’ disease (positive / negative predictive values, PPV/NPV), receiver operating characteristic (ROC) curves to explore the impact of different imaging derived metrics, multivariable multilevel regression analyses to quantify correlation of index to reference testing, and repeatability indices across protocols. Results40 children (77 eyes: 51 eyes at SUN grade 0, 10 at SUN0.5+, 8 at SUN1+, 8 SUN≥2+ or higher) were included. There was high repeatability across protocols (0.98, p<0.001, 95% CI 0.75-1.0). OCT resulted in strong predictive values for ‘ruling-out’ (LV-scan NPV 82.9%, 95% CI 71.5 - 90.4%; HV-scan NPV 100%, 95% CI 3% to 100%), and but less predictive value for ‘ruling-in’ SUN≥0.5+ (LV-scan PPV 52.8% 95% CI 41.5 - 63.7%; HV-scan PPV 34.2%, 95% CI 33.3 to 35.1%). Detection of more than 1 cell within a cross sectional scan was strongly suggestive of clinical activity, with area under the curve of 0.76 (95% CI 0.62 - 0.89) for SUN≥0.5+, and 0.85 (95% CI 0.73- 0.98), for the detection of SUN≥1+. Cell count correlated with SUN grades at higher levels of inflammation (SUN≥2+ both protocols, SUN≥1+ HV-scans). There was an independent positive association between age and AS-OCT cell (adjusted correlation coefficient 0.2 cells for each additional year of age). ConclusionsOperator dependent factors impact the diagnostic and quantification performance of AS-OCT for anterior chamber inflammation. However, the strong, ‘dose-respondent’ correlation of low-volume protocols with SUN grading promises clinical utility without the storage and analysis burden of high-volume approaches. Further work will involve exploration of the need for age-specific image metric interpretation.

Multi-scale tissue fluorescence mapping with fiber optic ultraviolet excitation and generative modeling

Cellular imaging of thick samples requires physical sectioning or laser scanning microscopy, which can be restrictive, involved, and generally incompatible with high-throughput requirements. We developed fiber optic microscopy with ultraviolet (UV) surface excitation (FUSE), a portable and quantitative fluorescence imaging platform for thick tissue that enabled quick sub-cellular imaging without thin sections. We substantially advanced prior UV excitation approaches with illumination engineering and computational methods. Optical fibers delivered &lt;300nm light with directional control, enabling unprecedented 50× widefield imaging on thick tissue with sub-nuclear clarity, and 3D topography of surface microstructure. Probabilistic modeling of high-magnification images using our normalizing flow architecture FUSE-Flow (made freely available as open-source software) enhanced low-magnification imaging with measurable localized uncertainty via variational inference. Comprehensive validation comprised multi-scale fluorescence histology compared with standard H&amp;E histology, and quantitative analyses of senescence, antibiotic toxicity, and nuclear DNA content in tissue models via efficient sampling of thick slices from entire murine organs up to 0.4×8×12mm and 1.3 million cells per surface. This technology addresses long-standing laboratory gaps in high-throughput studies for rapid cellular insights.

Comparison between 2D and 3D microstructures and implications for metamorphic constraints using a chloritoid–garnet-bearing mica schist

Abstract. Despite the fact that rock textures depend on the 3D spatial distribution of minerals, our tectono-metamorphic reconstructions are mostly based on a 2D visualisation (i.e. thin sections). This work compares 2D and 3D investigations of petrography and microstructures, modal abundances, and local bulk rock composition and their implication for P–T estimates, showing the pros and cons and reliability of 2D analysis. For this purpose, a chloritoid–garnet-bearing mica schist from the Dora-Maira Massif in the Western Alps has been chosen. In particular, for 2D a thin section scan has been combined with chemical X-ray maps, whereas for 3D the X-ray computerised axial microtomography (µCT) has been applied. Two-dimensional investigations are readily accessible and straightforward but do not consider the entire rock volume features. Conversely, the rise of 3D techniques offers a more comprehensive and realistic representation of metamorphic features in the 3D space. However, they are computationally intensive, requiring specialised tools and expertise. The choice between these approaches should be based on the research aims, available resources, and the level of detail needed to address specific scientific questions. Nevertheless, despite differences in the modal distribution, the estimated bulk rock compositions and relative thermodynamic modelled phase fields show similarities when comparing the 2D and 3D results. Also, since different thin section cut orientations may influence the results and consequent interpretations, three different cuts from the 3D model have been extrapolated and discussed (i.e. XZ, YZ, and XY planes of the finite-strain ellipsoid). This study quantitatively corroborates the reliability of the thin section approach for tectono-metamorphic reconstructions, still emphasising that 3D visualisation can help understand rock textures.

Evaluating the Quality of Serial EM Sections with Deep Learning.

Automated image acquisition can significantly improve the throughput of serial section scanning electron microscopy (ssSEM). However, image quality can vary from image to image depending on autofocusing and beam stigmation. Automatically evaluating the quality of images is, therefore, important for efficiently generating high-quality serial section scanning electron microscopy (ssSEM) datasets. We tested several convolutional neural networks for their ability to reproduce user-generated evaluations of ssSEM image quality. We found that a modification of ResNet-50 that we term quality evaluation Network (QEN) reliably predicts user-generated quality scores. Running QEN in parallel to ssSEM image acquisition therefore allows users to quickly identify imaging problems and flag images for retaking. We have publicly shared the Python code for evaluating images with QEN, the code for training QEN, and the training dataset.

Trajectory prediction of rigid projectile for oblique penetration into multi-layer aluminum targets

Multi-layer targets and nonideal initial conditions significantly increase the complexity of penetration trajectory prediction. To address this issue, a general multi-layer target trajectory model was developed based on expanding spherical cavity in layered finite targets, comprising the wake separation and finite free-surface effects. The trajectory prediction model adopted the developed geometric description of the ogive- and conical-nosed projectiles, combined with the proposed transfer functions and plane motion equation. Experiments of the two types projectiles penetration into layered 2A12 aluminum targets were conducted, and the actual projectile trajectories in targets were obtained through the section scan method. The predicted trajectories aligned well with the experimental data within the application range. The layering effect considerably influences the projectile trajectories impacting at higher velocities and oblique angles. More layers reduce the resistance of the targets, increasing the penetration but reducing the angle deflection of the trajectory performance. Compared with the ogive projectile, the conical projectile exhibited a deeper penetration and improved anti-deflection capabilities. This preliminary study on penetration trajectory characteristics of multi-layer targets provides experimental and theoretical support for correcting penetration trajectories.

Water shutoff treatment of low permeable reservoirs by in situ polymerization: laboratory scale development and verification through core flow experiments

Excessive water generation in oil reservoirs poses economic challenges, diminishing hydrocarbon yield and incurring additional costs for water management. This study focuses on enhancing reservoir conformance control, particularly in low-permeability zones with high water production, where traditional gel-based methods face limitations. The goal is improved penetration into narrow fractures and effective sealing of water-inflow zones through in situ polymerization and sequential cross-linking. The study systematically optimized key polymerization parameters, including initiator/monomer ratios, initiator types, and environmental conditions. Core flooding tests demonstrated a significant 17% increase in original oil recovery, alongside a substantial reduction in permeability. Analytical techniques such as CT scans, thin section scans, SEM, and EDS were employed to assess gel distribution within pores and penetration rates. This in situ polymerization and gelation approach show promise in addressing water production challenges, offering enhanced recovery, and adapting well to diverse reservoir conditions. The comprehensive optimization of polymerization parameters and the use of advanced analytical methods contribute to the study’s potential impact on mitigating economic and operational issues associated with excessive water production in oilfields.

Zygotic quiescence prolongs the reproductive cycle in Berchemia sinica (Rhamnaceae)

More than two-thirds of the species in Berchemia exhibit remarkable reproductive phenology, characterized by prolonged fruit ripening and the occurrence of overlapping fruit ripening and flowering. However, the underlying reasons for these phenomena remain unknown. Therefore, this study employed routine paraffin section technology, histochemical technique and scanning electron microscopy to investigate embryo sac development, differences between male and hermaphroditic flowers, as well as the overwintering strategy in Berchemia sinica. The findings of this study revealed a significant reduction in pollen viability and the number of pollen grains per flower in hermaphroditic compared to male flowers. Following fertilization, the ovary of hermaphroditic flowers does not undergo significant enlargement but gradually enters the state of zygotic quiescence. Zygotic quiescence prolongation is the main reason for the long reproductive cycle of B. sinica, and it takes approximately 14 months for the entire cycle from flower bud differentiation to fruit ripening to complete. Long reproductive cycle and complex overwintering mechanism exhibited by B. sinica resemble those seen in species belonging to Betulaceae, Fagaceae, Tapisciaceae, and Theaceae, suggesting convergent evolution during Earth's glacial period resulted in similar adaptive structures among these groups delayed fruit ripening leads to overlap between current year's flowers with previous year's fruits. The trade-off between flower and fruit for reproductive resources may have driven evolutionary transition from ancestral hermaphroditism towards androdioecy in Berchemia.

A compositional and technological reassessment of the function of potters’ marks on Early Bronze Age sherds from Tell el-‘Abd, Syria

A highly distinctive feature of the Early Bronze Age ceramic assemblage of the site of Tell el-‘Abd in northern Syria is the presence of large numbers of pots that were incised with a diverse range of symbols prior to firing. Several hypotheses have been proposed to explain the function of such ceramic “potters’ marks”. One is that they functioned as a signature or trademark used by potters or workshops to identify their work. Another possibility is that they were used for quality control or accounting purposes during manufacture. Alternatively, they may have signified vessels intended for specific customers, or the size or contents of the vessels. In the case of the Tell el-‘Abd potters’ marks, distinguishing between these possibilities has proven difficult based upon their macroscopic examination and archaeological context alone. The present research, therefore, attempts to shed further light on the function of the potters’ marks by studying the clay paste recipes of 33 ceramic samples using scientific methods. Thin section petrography, instrumental geochemistry and scanning electron microscopy have been used to characterise and classify sherds according to their raw materials and manufacturing technology. This has been compared to the type of potters’ mark and other archaeological information in order to test the hypotheses that the distinctive ceramic markings signified ceramics made at different production centres or distinguished between different artisans operating at the same workshop.

Risk Assessment and Analysis of Rock Burst under High-Temperature Liquid Nitrogen Cooling

Rock burst, an important kind of geological disaster, often occurs in underground construction. Rock burst risk assessment, as an important part of engineering risk assessment, cannot be ignored. Liquid nitrogen fracturing is a new technology used in the geological, oil, and gas industries to enhance productivity. It involves injecting liquid nitrogen into reservoir rocks to induce fractures and increase permeability, effectively reducing rock burst occurrences and facilitating the flow of oil or gas toward the wellbore. The research on rock burst risk assessment technology is the basis of reducing rock burst geological disasters, which has important theoretical and practical significance. This article examines the temperature treatment of two types of rocks at 25 °C, 100 °C, 200 °C, 300 °C, and 400 °C, followed by immersion in a liquid nitrogen tank. The temperature difference between the liquid nitrogen and the rocks may trigger rock bursting. The research focused on analyzing various characteristics of rock samples when exposed to liquid nitrogen. This included studying the stress–strain curve, elastic modulus, strength, cross-section analysis, wave velocity, and other relevant aspects. Under the influence of high temperature and a liquid nitrogen jet, the wave velocity of rocks often changes. The structural characteristics and possible hidden dangers of rocks can be understood more comprehensively through section scanning analysis. The stress–strain curve describes the deformation and failure behavior of rocks under different stress levels, which can help to evaluate their stability and structural performance. The investigation specifically focused on the behavior of rocks subjected to high temperatures and liquid nitrogen. By analyzing the stress–strain curves, researchers were able to identify the precursors and deformation processes that occur before significant deformation or failure. These findings have implications for the mechanical properties and stability of the rocks.

Origin of the parasitic luminescence of 235 nm UVC LEDs grown on different AlN templates

AlN layers annealed at high temperatures offer low threading dislocation densities of mid 108 cm−2 and are therefore increasingly used as base layers in ultraviolet (UV) light emitting diode (LED) heterostructure growth. These LEDs, just like those grown on conventional metalorganic vapor phase epitaxy (MOVPE) AlN templates, often suffer from long-wavelength parasitic luminescence. In this work, luminescence properties of far-UVC LED heterostructures grown on MOVPE-AlN/sapphire templates and high-temperature annealed AlN/sapphire templates are compared. To investigate the origin of parasitic emission with high spatial resolution, cross section scanning transmission electron microscopy was combined with cathodoluminescence measurements. As a result, the main origin of the parasitic luminescence band centered at 3.5 eV (354 nm) for the heterostructure grown on annealed AlN is assigned to point defects related to oxygen in the AlN template layer. The defect band centered at 3.0 eV (413 nm) for the heterostructure grown on MOVPE-AlN was found to be related to self-compensating VAl-Si point defect complexes in the n-AlGaN layer and oxygen incorporation close to the AlN/sapphire interface. The results also suggest that the type of AlN template determines the kind of parasitic luminescence from the n-AlGaN layer.

Influences of different alkaline and acidic diagenetic environments on diagenetic evolution and reservoir quality of alkaline lake shales

Thin section and argon-ion polishing scanning electron microscope observations were used to analyze the sedimentary and diagenetic environments and main diagenesis of the Permian Fengcheng Formation shales in different depositional zones of Mahu Sag in the Junggar Basin, and to reconstruct their differential diagenetic evolutional processes. The diagenetic environment of shales in the lake-central zone kept alkaline, which mainly underwent the early stage (Ro<0.5%) dominated by the authigenesis of Na-carbonates and K-feldspar and the late stage (Ro0.5%) dominated by the replacement of Na-carbonates by reedmergnerite. The shales from the marginal zone underwent a transition from weak alkaline to acidic diagenetic environments, with the early stage dominated by the authigenesis of Mg-bearing clay and silica and the late stage dominated by the dissolution of feldspar and carbonate minerals. The shales from the transitional zone also underwent a transition from an early alkaline diagenetic environment, evidenced by the formation of dolomite and zeolite, to a late acidic diagenetic environment, represented by the reedmergnerite replacement and silicification of feldspar and carbonate minerals. The differences in formation of authigenic minerals during early diagenetic stage determine the fracability of shales. The differences in dissolution of minerals during late diagenetic stage control the content of free shale oil. Dolomitic shale in the transitional zone and siltstone in the marginal zone have relatively high content of free shale oil and strong fracability, and are favorable “sweet spots” for shale oil exploitation and development.

Fluorescence and magnetic resonance imaging of ONL-93 cells in a rat model of ischemic

ObjectivesThe current methods for detecting myelin changes in ischemic stroke are indirect and cannot accurately reflect their status. This study aimed to develop a novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin. MethodsCompounds 7a and 7b were synthesized by linking the MeDAS group and Gadolinium (III) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate. Compound 7a was selected for characterization and further study. Cell uptake, cytotoxicity, and magnetic resonance imaging scans were performed on cells. In vitro experiments on frozen brain sections from 7-day-old, 8-week-old, and ischemic stroke rats were compared with commercially available Luxol Fast Blue staining. After HPLC and MR scanning, brain tissue was soaked in 7a and scanned using T1WI and T1maps sequences. ResultsSpectrophotometer results showed that compounds 7a and 7b had fluorescent properties. MR scans indicated that the compounds had contrast agent properties. Cells could uptake 7a and exhibited high signals in imaging scans. Compound 7a brain tissue staining showed more fluorescence in myelin-rich regions and identified injury sites in ischemic stroke rats. MR scanning of brain sections provided clear myelin contrast. ConclusionA novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin was successfully developed and tested in rats with ischemic stroke. These findings provide new insights for the clinical diagnosis of demyelinating diseases.

Sol-gel Spin Coated Hydrophilic Composite Titania-Silica Coatings on the Glass Substrates for Automotive Applications

The pollutants from the environment can also degrade the surface of the glass, which result in loss of transmittance of the glass surface. This necessitates the formation of a dedicated crew for the correct maintenance of glass furniture, notably in the Middle East. In this paper, we describe sol-gel spin coating of titania thin films on glass substrates, which may function as a hydrophilic coating by spreading water molecules across the substrate and removing pollutants and other dust particles, hence eliminating the need for maintenance and wipers. The fabricated coating was tested with X-ray diffractogram (XRD) and evidenced anatase nature of titania and amorphous nature of silica at Bragg angle 25° in the coating. Fourier transform infrared spectroscopy (FTIR) investigations endorsed Ti-O-Ti and Si-O-Si functional linkages at wavenumbers 551, and 957 cm-1 demonstrating the presence of titania and silica in the as-developed coating. Cross sectional field emission scanning electron microscopy (FESEM) investigation evidenced the formation of composite titania-silica film on the glass substrate with a thickness about 36 nm. The coating transmittance was studied by ultraviolet-visible and near-infrared (UV-Vis-NIR) spectroscopy and found 95% transmittance in the visible region. Moreover, wetting study utilizing the sessile drop technique yielded a 74° contact angle when the water droplets were interacted.

Better late (Roman) than never! A possible amphora fragment from 6th century Balatonlelle, Western Hungary

This study reports on a unique finding connected to the re-examination of the ceramic assemblage recovered from the Langobard age (6th century AD) settlement of Balatonlelle, situated in the territory of the former Roman province of Pannonia (now in western Hungary). An undecorated body sherd, not picked up by either the initial typological evaluation of the ceramics or by the preliminary petrographic analysis, was now reassessed by thin section ceramic petrography and scanning electron microscopy. The new analyses revealed that this sherd contains rock and mineral inclusions originated from ophiolites, including slightly serpentinised peridotite fragments. Such rocks do not occur on the surface in Hungary, whereas they are commonly found in the Eastern Mediterranean. The presence of ophiolites in the potsherd indicates that this vessel was produced in a distant territory. The macroscopic characteristics of the sherd combined with its petrographic fingerprint suggest that this pot might have been a transport amphora produced in the Eastern Mediterranean. Although rarely found in Pannonia in the Migration Period, several amphora types, including the most frequently found LRA 1 type, were produced in numerous production centres in the Eastern Mediterranean, in territories geologically congruous with the aplastic inclusions found in the fabric of the Balatonlelle sherd. The significance of this finding is that from Langobard age Pannonia, amphorae occur only sporadically, connected mainly to former Roman settlements. While any conclusions drawn from a single sherd must necessarily remain tentative, this sherd nonetheless provides some material evidence for the existence of some sort of contact between Balatonlelle and the Eastern Mediterranean during the 6th century, be it economic, political or cultural. This study also aims to celebrate the career of György Szakmány, who was one of the key figures to establish ceramic petrographic research and education in Hungary, and trained many generations of petrographers – including the present authors. As such, it also serves as an example how ceramic petrography can bring a new dimension of information to archaeological research.

Visual transformer and deep CNN prediction of high-risk COVID-19 infected patients using fusion of CT images and clinical data

BackgroundDespite the globally reducing hospitalization rates and the much lower risks of Covid-19 mortality, accurate diagnosis of the infection stage and prediction of outcomes are clinically of interest. Advanced current technology can facilitate automating the process and help identifying those who are at higher risks of developing severe illness. This work explores and represents deep-learning-based schemes for predicting clinical outcomes in Covid-19 infected patients, using Visual Transformer and Convolutional Neural Networks (CNNs), fed with 3D data fusion of CT scan images and patients’ clinical data.MethodsWe report on the efficiency of Video Swin Transformers and several CNN models fed with fusion datasets and CT scans only vs. a set of conventional classifiers fed with patients’ clinical data only. A relatively large clinical dataset from 380 Covid-19 diagnosed patients was used to train/test the models.ResultsResults show that the 3D Video Swin Transformers fed with the fusion datasets of 64 sectional CT scans + 67 clinical labels outperformed all other approaches for predicting outcomes in Covid-19-infected patients amongst all techniques (i.e., TPR = 0.95, FPR = 0.40, F0.5 score = 0.82, AUC = 0.77, Kappa = 0.6).ConclusionsWe demonstrate how the utility of our proposed novel 3D data fusion approach through concatenating CT scan images with patients’ clinical data can remarkably improve the performance of the models in predicting Covid-19 infection outcomes.SignificanceFindings indicate possibilities of predicting the severity of outcome using patients’ CT images and clinical data collected at the time of admission to hospital.

A Stable, Efficient, and High-Precision Non-Coplanar Calibration Method: Applied for Multi-Camera-Based Stereo Vision Measurements.

Traditional non-coplanar calibration methods, represented by Tsai's method, are difficult to apply in multi-camera-based stereo vision measurements because of insufficient calibration accuracy, inconvenient operation, etc. Based on projective theory and matrix transformation theory, a novel mathematical model is established to characterize the transformation from targets' 3D affine coordinates to cameras' image coordinates. Then, novel non-coplanar calibration methods for both monocular and binocular camera systems are proposed in this paper. To further improve the stability and accuracy of calibration methods, a novel circular feature points extraction method based on region Otsu algorithm and radial section scanning method is proposed to precisely extract the circular feature points. Experiments verify that our novel calibration methods are easy to operate, and have better accuracy than several classical methods, including Tsai's and Zhang's methods. Intrinsic and extrinsic parameters of multi-camera-systems can be calibrated simultaneously by our methods. Our novel circular feature points extraction algorithm is stable, and with high precision can effectively improve calibration accuracy for coplanar and non-coplanar methods. Real stereo measurement experiments demonstrate that the proposed calibration method and feature extraction method have high accuracy and stability, and can further serve for complicated shape and deformation measurements, for instance, stereo-DIC measurements, etc.