共查询到20条相似文献,搜索用时 31 毫秒
1.
The application of design-based stereological methods for estimating nuclear features quantitatively in invasive ductal breast cancer is described. Nuclear number, size and size variability are explored in relation to the tumour grade and patient prognosis. The study includes an examination of the efficiency in estimating different nuclear volumes, and two different estimators of the nuclear size variability are contrasted. Forty-two invasive ductal breast carcinomas diagnosed and graded by two pathologists were used. Both 5-μm and 25-μm-thick sections were obtained from paraffin blocks for stereological study. More undifferentiated tumours show significantly larger nuclei than low-grade tumours. The estimates based on the disector method demonstrate a decrease in the number of tumour cell nuclei per unit volume of tissue from grades 1 to 2 and especially from grades 2 to 3. The univariate survival analysis shows a high prognostic value of the nuclear volume estimates. The study shows that an efficient sampling procedure was performed, particularly when estimating volume-weighted mean nuclear volume using the point-sampled intercepts method. This method is more efficient than estimation of the number-weighted mean nuclear volume using the selector method; however, the latter provides paired estimates of volume- and number-weighted mean nuclear volume, as well as an estimate of the coefficient of variation of nuclear volume in the number distribution of the same cells. 相似文献
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In the present study, 53 cases of squamous cell carcinomas of the head and neck were characterized by a quantitative histological texture analysis based on principles of spatial statistics. A planar tessellation of the epithelial tumour component was generated by a skeletonization algorithm. The size distribution of the virtual cells of this planar tessellation, and the size distribution of the profiles of the tumour cell nuclei were estimated in terms of area and boundary length. The intensity, the reduced second moment function (K‐function) and the pair correlation function of the point process of the centroids of the profiles of the tumour cell nuclei were also estimated. For both purposes, it is necessary to correct for edge effects, which we consider in this paper in some detail. Specifically, the point patterns of the tumour cell nuclei were considered as realizations of a point process, where the points exist only in the epithelial tumour component (the permitted phase) and not in the stroma (the forbidden phase). The methods allow to characterize each individual tumour by a series of summary statistics. The total set of cases was then partitioned into two groups: 19 cases without lymph node metastases (pN0), and 34 nodal positive cases (pN1 or pN2). Statistical analysis showed no significant differences between the intensities, the mean K‐functions and the mean pair correlation functions of the tumour cell nucleus profiles of the two groups. However, there were some significant differences between the sizes of the virtual cells and of the nucleus profiles of the nodal negative cases as compared to the nodal positive cases. In a logistic regression analysis, one of the quantitative nuclear size variables (mean nuclear area) was found to be a significant predictor of lymph node metastasis, in addition to tumour stage. The study shows the potential of methods of spatial statistics for objective quantitative grading of squamous cell carcinomas of the head and neck, and provides an example for modelling histological point patterns as realizations of planar point processes occupying a reference phase which is only a partial component of the total tissue. 相似文献
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Murata S Mochizuki K Nakazawa T Kondo T Nakamura N Yamashita H Urata Y Ashihara T Katoh R 《Microscopy research and technique》2003,61(5):457-462
Various morphonuclear studies by digital image analysis have successfully been applied to quantify the nuclear morphology, including chromatin distribution pattern, in cytology of various organs; however, the majority of past reports have not shown correlation between the quantitative data by digital image analysis and cytological findings in practical diagnosis. In this report, we present the usefulness of morphological abstraction to combine the objective data and subjective observation in cytological diagnosis. Randomly selected, 100 cells in each Papanicolaou-stained ABC smear samples of 39 benign and malignant thyroid tumor cases were studied. Gray-level image data provided seven parameters for nuclear size, four parameters for nuclear shape, and 16 parameters showing the nuclear chromatin patterns from high-dimensional texture analysis of using co-occurrence and run-length matrices. To statistically abstract nuclear morphology, factor analysis was used. Factor analysis classified morphological nuclear characters as abstraction parameter into five abstract parameters composed of nuclear size, shape, heterogeneity, and contrast and homogeneity of chromatin pattern. The nuclei of papillary carcinoma showed larger size, more irregular shape, and higher contrast of chromatin pattern than those of the benign group. The follicular carcinomas have larger nucleus in each cell and more monotonous chromatin pattern among cells in each case than those of the benign group. Morphological abstraction by morphometry with factor analysis may provide a practical approach to the detection of the underlying characteristics of nuclear morphology in aspiration biopsy cytology. 相似文献
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Confocal scanning laser microscopy provides the opportunity to obtain three-dimensional (3-D) images by piling up consecutive confocal planes. This technique was applied to capture 3-D images from 100-μm-thick tissue blocks from prostate lesions (hyperplasia, dysplasia, adenocarcinomas). Automated methods were implemented to perform a nuclear grading of 3-D cell nuclei from these specimens. Special attention was focused on the development of a new approach to 3-D chromatin texture analysis. This method uses mathematical morphology operations to tessellate the chromatin into homogeneous domains. The nuclear features (volume, shape, texture) were subjected to a discriminant analysis. Using a set of five features, the classification of cell nuclei yielded an accuracy of 963%. The results indicate the potential of 3-D imaging and analysis techniques for an automated nuclear grading of prostate lesions. 相似文献
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Z. Wang S. Tse Y. Goa X. Xia 《The International Journal of Advanced Manufacturing Technology》2003,21(2):119-125
In many cases we may have several approaches to realise a precision measurement. It is very important to decide on an optimal
measurement approach or plan in order to obtain effectively high-fidelity results. A measurement process may involve many
kinds of error factors which vary in different measurement plans. This would make the selection of the most appropriate approach
difficult. Currently, prior knowledge of the relationship between measured variables and error factors, and statistical methods
are typically used for such selection. In many cases, however, the relationship may not be clear, due to non-quantitative
factors being involved. To solve the problem, a new method that is based on fuzzy set theory is proposed. In this method,
membership grades are established and grades to the quasi-perfect plan are maximised. Mathematical models are established
and the concept of a quasi-perfect measurement plan is proposed. Experimental testing is presented in order to demonstrate
the effectiveness of the proposed method. 相似文献
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《Measurement》2014
Wheat product quality is closely related to wheat seed purity. Purity is an important factor that has a considerable impact on wheat product prices in grain storage silos. The aim of this paper was to introduce a machine vision based approach as a primarily step for fabricating an automatic wheat purity determination and grading device. Experimental data consists of 52 color, morphology, and texture characteristic parameters, extracted from images of samples, including four local wheat grades and eight common weed seeds growing in wheat fields of Iran, were used to build the classification models. A new algorithm that combines Imperialist Competitive Algorithm (ICA) and Artificial Neural Networks (ANNs) has been used for two purposes: to find the best characteristic parameters set and to create robust classification models. Based upon the results obtained from this study, the total classification rate of ICA–ANN approach for wheat grains vs. non-wheat seeds, wheat grain classes, and non-wheat seed classes was 96.25%, 87.50%, and 77.22%, respectively. 相似文献
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针对目前脐橙品质分级自动化程度较低,难以满足现代化生产运营需求的问题,设计了一种基于树莓派平台的脐橙品质分级方法。在S和V颜色分量图像上完成背景分割,并对脐橙表面的反光区域进行亮度矫正;提取脐橙的大小和着色度特征,并提出基于积分图的局部阈值分割算法,完成果面缺陷的检测;利用决策树算法实现脐橙品质的分级。试验结果表明:此方法对特级果、一等果、二等果、等外果的识别准确率分别达到96%、94%、94%、96%,单列输送线的分级速率达3个/s,准确性和实时性较高,能够满足实时环境下脐橙分级检测的要求。 相似文献
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Irving Dardick Alexander M. Dardick M. T. Diane Jeans Peter Rippstein Douglas R. Caldwell 《Microscopy research and technique》1985,2(6):597-609
Currently, quantitative studies of malignant lymphoma are being performed in an attempt to improve the classification of non-Hodgkin's lymphoma (NHL) for diagnostic, prognostic, and therapeutic purposes. Morphometric image analysis is one method that can be employed in cases of NHL to obtain objective data of nuclear parameters; condensed chromatin being a compartment of the nucleus best measured at the ultrastructural level. This report assesses similarities or differences in the amount, distribution, and arrangement of condensed chromatin in nuclear profiles of normal and neoplastic lymphocytes in human surgical biopsy specimens. Morphometric data derived from electron micrographs of lymphocytes in germinal centers of lymph nodes with reactive hyperplasia (three cases) and small cell types of NHL two examples of malignant lymphoma, well differentiated lymphocytic type (ML, WDL) and three cases of malignant lymphoma, poorly differentiated lymphocytic type (ML, PDL) are compared. Results indicate that the distribution of condensed chromatin, i.e., the size of aggregates, and their spatial placement within the nucleus varies more than the amount (both mean area per profile or mean volume) of this nuclear parameter, and that this applies to normal as well as neoplastic lymphocytes. When a series of condensed chromatin parameters were statistically compared, no major differences could be detected between lymphocytes in normal tissues and those in ML, WDL and ML, PDL, but considerable differences were found in each of the nuclear morphotypes in the individual cases within the groups. This degree of variation in nuclear characteristics within normal tissues and the two lymphoma categories has not been previously recognized. Clearly, the technique of morphometric analysis, as applied to electron micrographs, can provide new and useful data that must be appreciated if classification schemes currently used in NHL are to improve and reflect biologic considerations. 相似文献
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The basement membrane of human corneal epithelial cells (HCECs) has a three-dimensional nanoscale architecture, which includes pores, bumps and fibers that may influence cell-substrate adhesion and spreading in the overlying cells. We previously demonstrated that nano- and microscale groove and ridge patterns influence the morphological response and the adhesive response of HCECs to a nominal wall shear stress. Cell-substrate adhesion is mediated by adhesion receptors that bind to extracellular matrix components and anchor the cytoskeleton (CSK) of cells to extracellular elements. Here we investigate the CSK organization in SV40-transformed HCECs grown on nano- and microscale groove and ridge patterns. X-ray lithography was used to fabricate uniform groove and ridge patterns with features ranging in size from 200 nm to 2 microm grooves. Scanning electron microscopy and transmission electron microscopy were used to investigate CSK structure and the distribution of -beta1 integrin adhesion receptors. CSK elements aligned with the patterns; however, the spatial organization of these elements was influenced by feature size. Larger CSK bundles lay on top of the ridges and ran parallel to the patterns, whereas smaller CSK bundles, whose width was proportional to the groove size, spanned the grooves. -Beta1 integrins co-localized with the CSK and had a higher density at the poles of aligned spindle-shaped cells. Differences in organization seen on the different topographical feature sizes may be indicative of differences in extracellular matrix organization. This may explain, in part, previous observations regarding the dependence of cell adhesive responses on the size of topographic features in the substrate. 相似文献
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R. T. Lee W. S. Cheng 《The International Journal of Advanced Manufacturing Technology》2002,19(5):313-317
When working with a computer-aided design system (CAD), it is often necessary to rescale a geometrical model. CurrentCAD software
packages can provide only one scale factor for all three axes or one scale factor for each of the three axes. Therefore, difficulties
arise when more than one scale factor is required in any of the three axis directions.
In the shoe industry, a sample shoe sole is first designed for each shoe style. This sample sole is used as a standard for
grading (scaling) for every size of shoe soles. This grading process must scale the sample sole by different factors in different
zones. Thus current CAD systems cannot be applied.
A multizone scaling method is presented to satisfy this need. Engineers create a set of 3D B-spline curves for the sample
shoe sole using a CAD system. This method then divides the CAD geometrical model into several zones in each of the X-, Y-,
Z-axes and each zone is given a scaling dimension (value) to generate a new CAD geometrical model. A CAD geometrical model
for every size of shoe soles can be produced by this multizone scaling method. 相似文献
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Richard H. Caro 《ISA transactions》1989,28(4):23-28
The “fifth generation” architecture for process control systems will be based on the use of a “field bus” as being defined by the ISA SP50 standards committee. While a name has not yet been given to this architecture, this paper will call it “Network Control” to distinguish it from the fourth generation “Distributed Control”. While all previous generations worked to increase the operator's span of control, this new architecture will achieve most of its benefits through increased functionality and performance and decreased installed cost. One major driving force for this architecture should be the rapid segmentation of the process control market where parts of a total system would be supplied by the vendors most able to meet the user's needs at the lowest price. The effect of this will be a restructuring of the process control market, to the benefit of those users who can take advantage of the changed product offerings. While it is expected that all of the traditional process control system vendors will participate with their total product lines, they will no longer be able to control the market. The new functionality may also be the final blow to second generation pneumatic and electronic analog control systems. 相似文献
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研究了基于计算机视觉的干枣在线分级,通过计算机视觉技术获取干枣的图像,对该图像进行阈值分割等处理,确定干枣的检测方向,进一步对干枣的尺寸、颜色、缺陷等进行快速精确的分类。试验表明,该方法检测速度快,正确率高,适用范围宽,能够满足农产品加工过程中计算机视觉水果分级技术的要求。 相似文献
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Coherent diffraction imaging of single biomolecules is expected to open unique opportunities for studies of non-crystalline samples. There are, however, still many technical and physical issues that need to be resolved in a more quantitative manner, especially if one aims for structural information at high resolution. Signal recorded from an object after a single shot is low. As primarily proposed in Spence and Doak (2004) and Huldt et al. (2003) [1] and [2], averaging over the diffraction patterns from many different shots is necessary, in order to achieve a signal-to-noise ratio sufficient for image reconstruction. The images of the randomly oriented molecules have to be sorted out in order to identify those corresponding to the similar spatial orientations of the objects. This procedure is called the classification of diffraction images. Here we approach the classification in the framework of pattern-to-pattern correlations, and analyse theoretically the correlations between diffraction images of differently oriented objects. 相似文献
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Nauman Munir Hak-Joon Kim Sung-Jin Song Sung-Sik Kang 《Journal of Mechanical Science and Technology》2018,32(7):3073-3080
Ultrasonic signal classification of defects in weldment, in automatic fashion, is an active area of research and many pattern recognition approaches have been developed to classify ultrasonic signals correctly. However, most of the developed algorithms depend on some statistical or signal processing techniques to extract the suitable features for them. In this work, data driven approaches are used to train the neural network for defect classification without extracting any feature from ultrasonic signals. Firstly, the performance of single hidden layer neural network was evaluated as almost all the prior works have applied it for classification then its performance was compared with deep neural network with drop out regularization. The results demonstrate that given deep neural network architecture is more robust and the network can classify defects with high accuracy without extracting any feature from ultrasonic signals. 相似文献
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Ductal carcinoma in situ (DCIS) of the breast is a premalignant condition which accounts for approximately 20% of all new breast cancers and up to 40% of neoplastic lesions detected by mammographic screening. Since recurrence is common after DCIS treated with breast conservation surgery, there is a need to determine molecular factors that predict recurrence. In parallel with this and with the finding that oestrogen receptor (ER) positive breast cancer can be prevented with anti-oestrogens, there have been recent advances in the understanding of the molecular biology of DCIS. Receptor coexpression in DCIS has been determined largely by immunohistochemistry. Animal models have provided evidence for the signalling pathways involved in the regulation and dysregulation of proliferation and apoptosis in both normal breast and in situ cancer. ER-negative DCIS has been shown to be hormone-independent. Blockade of the pathways involved in cell proliferation in ER-negative DCIS is possible and will be necessary to prevent ER-negative breast cancers if the goal of breast cancer chemoprevention is to be realistically achieved. 相似文献