基于LabVIEW的荧光标记图像检测系统

用LabVIEW实现荧光标记图像的采集和定量分析,设计了一个基于虚拟仪器的视觉检测器。采用IMAQUSB代替了传统的图像采集卡,不仅降低了系统的开发成本,而且操作方法更加简单、高效。用数值和图像两种形式实现了对目标荧光图像的定量分析,并通过彩色图像的RGB值近似估计该荧光的波长,来实现定性分析。模拟实验的结果表明：该系统运行稳定,测试较为精准。     

Effects of Human and Porcine Adipose Extracellular Matrices Decellularized by Enzymatic or Chemical Methods on Macrophage Polarization and Immunocompetence

The decellularized extracellular matrix (ECM) obtained from human and porcine adipose tissue (AT) is currently used to prepare regenerative medicine bio-scaffolds. However, the influence of these natural biomaterials on host immune response is not yet deeply understood. Since macrophages play a key role in the inflammation/healing processes due to their high functional plasticity between M1 and M2 phenotypes, the evaluation of their response to decellularized ECM is mandatory. It is also necessary to analyze the immunocompetence of macrophages after contact with decellularized ECM materials to assess their functional role in a possible infection scenario. In this work, we studied the effect of four decellularized adipose matrices (DAMs) obtained from human and porcine AT by enzymatic or chemical methods on macrophage phenotypes and fungal phagocytosis. First, a thorough biochemical characterization of these biomaterials by quantification of remnant DNA, lipids, and proteins was performed, thus indicating the efficiency and reliability of both methods. The proteomic analysis evidenced that some proteins are differentially preserved depending on both the AT origin and the decellularization method employed. After exposure to the four DAMs, specific markers of M1 proinflammatory and M2 anti-inflammatory macrophages were analyzed. Porcine DAMs favor the M2 phenotype, independently of the decellularization method employed. Finally, a sensitive fungal phagocytosis assay allowed us to relate the macrophage phagocytosis capability with specific proteins differentially preserved in certain DAMs. The results obtained in this study highlight the close relationship between the ECM biochemical composition and the macrophage’s functional role.     

Impact of Porcine Pancreas Decellularization Conditions on the Quality of Obtained dECM

Due to the limited number of organ donors, 3D printing of organs is a promising technique. Tissue engineering is increasingly using xenogeneic material for this purpose. This study was aimed at assessing the safety of decellularized porcine pancreas, together with the analysis of the risk of an undesirable immune response. We tested eight variants of the decellularization process. We determined the following impacts: rinsing agents (PBS/NH₃·H₂O), temperature conditions (4 °C/24 °C), and the grinding method of native material (ground/cut). To assess the quality of the extracellular matrix after the completed decellularization process, analyses of the following were performed: DNA concentration, fat content, microscopic evaluation, proteolysis, material cytotoxicity, and most importantly, the Triton X-100 content. Our analyses showed that we obtained a product with an extremely low detergent content with negligible residual DNA content. The obtained results confirmed the performed histological and immuno-fluorescence staining. Moreover, the TEM microscopic analysis proved that the correct collagen structure was preserved after the decellularization process. Based on the obtained results, we chose the most favorable variant in terms of quality and biology. The method we chose is an effective and safe method that gives a chance for the development of transplant and regenerative medicine.     

Upscaled CTAB-Based DNA Extraction and Real-Time PCR Assays for Fusarium culmorum and F. graminearum DNA in Plant Material with Reduced Sampling Error

Fusarium graminearum Schwabe (Gibberella zeae Schwein. Petch.) and F. culmorum W.G. Smith are major mycotoxin producers in small-grain cereals afflicted with Fusarium head blight (FHB). Real-time PCR (qPCR) is the method of choice for species-specific, quantitative estimation of fungal biomass in plant tissue. We demonstrated that increasing the amount of plant material used for DNA extraction to 0.5–1.0 g considerably reduced sampling error and improved the reproducibility of DNA yield. The costs of DNA extraction at different scales and with different methods (commercial kits versus cetyltrimethylammonium bromide-based protocol) and qPCR systems (doubly labeled hybridization probes versus SYBR Green) were compared. A cost-effective protocol for the quantification of F. graminearum and F. culmorum DNA in wheat grain and maize stalk debris based on DNA extraction from 0.5–1.0 g material and real-time PCR with SYBR Green fluorescence detection was developed.     

Myelin Quantification in White Matter Pathology of Progressive Multiple Sclerosis Post-Mortem Brain Samples: A New Approach for Quantifying Remyelination

Multiple sclerosis (MS) is a demyelinating and neurodegenerative disease of the central nervous system (CNS). Repair through remyelination can be extensive, but quantification of remyelination remains challenging. To date, no method for standardized digital quantification of remyelination of MS lesions exists. This methodological study aims to present and validate a novel standardized method for myelin quantification in progressive MS brains to study myelin content more precisely. Fifty-five MS lesions in 32 tissue blocks from 14 progressive MS cases and five tissue blocks from 5 non-neurological controls were sampled. MS lesions were selected by macroscopic investigation of WM by standard histopathological methods. Tissue sections were stained for myelin with luxol fast blue (LFB) and histological assessment of de- or remyelination was performed by light microscopy. The myelin quantity was estimated with a novel myelin quantification method (MQM) in ImageJ. Three independent raters applied the MQM and the inter-rater reliability was calculated. We extended the method to diffusely appearing white matter (DAWM) and encephalitis to test potential wider applicability of the method. Inter-rater agreement was excellent (ICC = 0.96) and there was a high reliability with a lower- and upper limit of agreement up to −5.93% to 18.43% variation in myelin quantity. This study builds on the established concepts of histopathological semi-quantitative assessment of myelin and adds a novel, reliable and accurate quantitative measurement tool for the assessment of myelination in human post-mortem samples.     

基于快速曲波变换的陶瓷显微图像处理

陶瓷内部结构信息对于陶瓷质量分析、生产工艺控制是非常重要的。由于陶瓷显微图像在采集和传输过程中不可避免地要受到光照分布不均匀、电子噪声等干扰因素的影响而使得图像的质量变差。需要首先对其进行去噪、增强处理,然后才能进行图像分析。曲波变换是在小波变换的基础上发展起来的一种新的多尺度分析方法,比小波更加适合分析二维图像中的曲线或直线状边缘特征,而且具有更高的逼近精度和更好的稀疏表达能力。快速曲波变换理论的提出也使得其理论更易理解和实现。因此,提出了一种基于快速曲渡变换的图像去噪、增强方法,并将其引入陶瓷显微图像的处理中,然后按照分水岭算法进行粒度分割,得到陶瓷粒度分布的统计结果。实验结果表明,该方法是可行的,并且效果良好。     

Comprehensive phase characterization of crystalline and amorphous phases of a Class F fly ash

A comprehensive approach to qualitative and quantitative characterization of crystalline and amorphous constituent phases of a largely heterogeneous Class F fly ash is presented. Traditionally, fly ash composition is expressed as bulk elemental oxide content, generally determined by X-ray fluorescence spectroscopy. However, such analysis does not discern between relatively inert crystalline phases and highly reactive amorphous phases of similar elemental composition. X-ray diffraction was used to identify the crystalline phases present in the fly ash, and the Rietveld quantitative phase analysis method was applied to determine the relative proportion of each of these phases. A synergistic method of X-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, and multispectral image analysis was developed to identify and quantify the amorphous phases present in the fly ash.     

A Decellularized Human Limbal Scaffold for Limbal Stem Cell Niche Reconstruction

The transplantation of ex vivo expanded limbal epithelial progenitor cells (LEPCs) on amniotic membrane or fibrin gel is an established therapeutic strategy to regenerate the damaged corneal surface in patients with limbal stem cell deficiency (LSCD), but the long-term success rate is restricted. A scaffold with niche-specific structure and extracellular matrix (ECM) composition might have the advantage to improve long-term clinical outcomes, in particular for patients with severe damage or complete loss of the limbal niche tissue structure. Therefore, we evaluated the decellularized human limbus (DHL) as a biomimetic scaffold for the transplantation of LEPCs. Corneoscleral tissue was decellularized by sodium deoxycholate and deoxyribonuclease I in the presence or absence of dextran. We evaluated the efficiency of decellularization and its effects on the ultrastructure and ECM composition of the human corneal limbus. The recellularization of these scaffolds was studied by plating cultured LEPCs and limbal melanocytes (LMs) or by allowing cells to migrate from the host tissue following a lamellar transplantation ex vivo. Our decellularization protocol rapidly and effectively removed cellular and nuclear material while preserving the native ECM composition. In vitro recellularization by LEPCs and LMs demonstrated the good biocompatibility of the DHL and intrastromal invasion of LEPCs. Ex vivo transplantation of DHL revealed complete epithelialization as well as melanocytic and stromal repopulation from the host tissue. Thus, the generated DHL scaffold could be a promising biological material as a carrier for the transplantation of LEPCs to treat LSCD.     

Color gamut mapping based on a perceptual image difference measure

Gamut mapping is a color transformation technique to solve a problem caused by mismatch of gamuts among imaging devices. One plausible goal of gamut mapping is to find a reproduction that is perceptually closest to the corresponding original image when an exact color matching is not possible. Several measures to quantify the perceptual difference between images have been proposed and applied to the gamut mapping problem. However most of the measures, such as average color difference, are applied on a pixel‐wise basis and show poor correlation with human visual perception. This article describes a model of the perceptual image difference for a given pair of images, which takes the human's contrast sensitivity into account and applies the model to a gamut mapping for generating a reproduction with minimum perceptual image difference. The model has a multispatial‐frequency channel structure with tunable peak gains for each channel, which are determined by psychophysical experiments, so that the model output fits the observer's sensitivity to the image difference. A gamut‐mapped image with minimum perceptual image difference is obtained by an iterative minimization process. To evaluate the proposed method, subjective evaluation experiments are performed to construct ratio scales that measure perceptual image difference of gamut‐mapped reproductions generated by the proposed and pixel‐wise methods. Results show that the reproductions by the proposed method are perceived as perceptually closest to the original, and the model's estimate of perceptual difference correlates better with the experimentally measured perceived image difference than other pixel‐wise measures. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 280–291, 1999     

Quantitative high-resolution sensing of DNA hybridization using magnetic tweezers with evanescent illumination

We applied the combined approach of evanescent nanometry and force spectroscopy using magnetic tweezers to quantify the degree of hybridization of a single synthetic single-stranded DNA oligomer to a resolution approaching a single-base. In this setup, the 200 nucleotide long DNA was covalently attached to the surface of an optically transparent solid support at one end and to the surface of a superparamagnetic fluorescent microsphere (force probe) at the other end. The force was applied to the probes using an electromagnet. The end-to-end molecular distance (i.e. out-of-image-plane position of the force probe) was determined from the intensity of the probe fluorescence image observed with total-internal reflectance microscopy. An equation of state for single stranded DNA molecules under tension (extensible freely jointed chain) was used to derive the penetration depth of the evanescent field and to calibrate the magnetic properties of the force probes. The parameters of the magnetic response of the force probes obtained from the equation of state remained constant when changing the penetration depth, indicating a robust calibration procedure. The results of such a calibration were also confirmed using independently measured probe-surface distances for probes mounted onto cantilevers of an atomic force microscope. Upon hybridization of the complementary 50 nucleotide-long oligomer to the surface-bound 200-mer, the changes in the force-distance curves were consistent with the quantitative conversion of 25% of the original single-stranded DNA to its double-stranded form, which was modeled as an elastic rod. The method presented here for quantifying the hybridization state of the single DNA molecules has potential for determining the degree of hybridization of individual molecules in a single molecule array with high accuracy.     

A Review of Ex Vivo X-ray Microfocus Computed Tomography-Based Characterization of the Cardiovascular System

Cardiovascular malformations and diseases are common but complex and often not yet fully understood. To better understand the effects of structural and microstructural changes of the heart and the vasculature on their proper functioning, a detailed characterization of the microstructure is crucial. In vivo imaging approaches are noninvasive and allow visualizing the heart and the vasculature in 3D. However, their spatial image resolution is often too limited for microstructural analyses, and hence, ex vivo imaging is preferred for this purpose. Ex vivo X-ray microfocus computed tomography (microCT) is a rapidly emerging high-resolution 3D structural imaging technique often used for the assessment of calcified tissues. Contrast-enhanced microCT (CE-CT) or phase-contrast microCT (PC-CT) improve this technique by additionally allowing the distinction of different low X-ray-absorbing soft tissues. In this review, we present the strengths of ex vivo microCT, CE-CT and PC-CT for quantitative 3D imaging of the structure and/or microstructure of the heart, the vasculature and their substructures in healthy and diseased state. We also discuss their current limitations, mainly with regard to the contrasting methods and the tissue preparation.     

指纹图像处理中方向滤波器的研究与实现

首先在对现有指纹图像预处理算法进行分析比较的基础上,系统介绍了方向滤波法对图像的处理过程,同时给出了指纹的数学模型.在此基础上,详细分析了方向滤波器的组成、模板的选取及其参数计算.最后利用计算机实现了方向滤波器对指纹图像的处理,取得了较好的效果.     

Quantification of the Immune Content in Neuroblastoma: Deep Learning and Topological Data Analysis in Digital Pathology

We introduce here a novel machine learning (ML) framework to address the issue of the quantitative assessment of the immune content in neuroblastoma (NB) specimens. First, the EUNet, a U-Net with an EfficientNet encoder, is trained to detect lymphocytes on tissue digital slides stained with the CD3 T-cell marker. The training set consists of 3782 images extracted from an original collection of 54 whole slide images (WSIs), manually annotated for a total of 73,751 lymphocytes. Resampling strategies, data augmentation, and transfer learning approaches are adopted to warrant reproducibility and to reduce the risk of overfitting and selection bias. Topological data analysis (TDA) is then used to define activation maps from different layers of the neural network at different stages of the training process, described by persistence diagrams (PD) and Betti curves. TDA is further integrated with the uniform manifold approximation and projection (UMAP) dimensionality reduction and the hierarchical density-based spatial clustering of applications with noise (HDBSCAN) algorithm for clustering, by the deep features, the relevant subgroups and structures, across different levels of the neural network. Finally, the recent TwoNN approach is leveraged to study the variation of the intrinsic dimensionality of the U-Net model. As the main task, the proposed pipeline is employed to evaluate the density of lymphocytes over the whole tissue area of the WSIs. The model achieves good results with mean absolute error 3.1 on test set, showing significant agreement between densities estimated by our EUNet model and by trained pathologists, thus indicating the potentialities of a promising new strategy in the quantification of the immune content in NB specimens. Moreover, the UMAP algorithm unveiled interesting patterns compatible with pathological characteristics, also highlighting novel insights into the dynamics of the intrinsic dataset dimensionality at different stages of the training process. All the experiments were run on the Microsoft Azure cloud platform.     

基于角点检测的裂纹瓷图像拼接及裂纹重建

对裂纹瓷表面的纹饰进行图像拼接,可更好地应用于纹理等外部特征的分析与瓷器鉴别.图像处理技术可实现快速、无损的陶瓷器检测与分析,弥补了传统检测方法的不足.本文以具有裂纹釉的龙泉青瓷茶杯为研究对象,提取瓷器的多个侧面图像,采用Harris角点检测方法提取图像中的角点,然后进行图像配准和拼接,将多侧面图像拼接为完整图像;通过...     

An aesthetic measurement method for matching colours in product design

Since it is important to know how to evaluate human emotions reflected in the image of a product during the process of product design precisely, a means of evaluating the aesthetic measurement of the image of a product with colour matching is proposed in this article. This method entails a solid visual angle of the subject, the distribution of colour‐area ratios, and colour images as experimental samples for colour matching. The evaluation was conducted based on a formula of the aesthetic measurement of the coloured area. To ensure that the entire practical colour co‐ordinate system was covered, 111 coloured chips were distributed throughout the implementation procedure. The aesthetic measure of colour harmony in this study was calculated based on aesthetic measure theory; moreover, each of the three given images received three symbolic colour combinations before using the fuzzy theory to determine the relationship between the image and the colour combinations of the products. Observers' evaluations of the fuzzy theory and the aesthetic measurement model were then compared, and the results showed that the proposed method succeeded in obtaining a high degree of satisfaction for the top 2 ranked samples in the aesthetic measurement model evaluation and human evaluation. Although only 2 product designs were used as examples for performing the evaluation procedure, the procedure can also be applied to other products.     

Solid Phase Enhanced Direct Spectrofluorometric Determination of Polychlorinated Biphenyls (PCBs) in Natural Waters

A method of detection of PCBs in water, based on extraction/concentration with chips cut from an SPE disk-shaped C18 inverse phase coupled with a fluorescence detection and quantification directly on the phase has been evaluated. Experiments were performed with PCBs congeners IUPAC N° 3, 35, 67 and 169. Within the experimental conditions used : Hitachi F-4500 fluorometer, band-paths: 2.5 nm and extraction time: 60 min. the limits of detection were estimated to be respectively : 0.07, 0.4, 0.3 and 0.2 ppb. These values are within the range of PCB concentrations found in highly polluted waters and thus confer some interest to the method. However its sensitivity is not sufficient for application to moderately polluted natural water and the method needs some further improvements. Moreover, fluorescence quenching by humic substances was shown to substantially affect PCB's fluorescence intensity and must be taken into consideration for quantitative analysis.     

基于分形理论的岩相图像识别与分析

基于分形理论 ,应用计算机数字图像处理技术 ,提出了一种岩相图像识别与分析的新方法。在对典型岩相图像进行图像处理的基础上 ,介绍了岩相轮廓的顺序跟踪识别方法 ,给出了岩相轮廓分形维数的具体计算公式和方法 ,最终得到不同岩相轮廓的分形维数。通过比较不同岩相的分形维数可知 ,同一种岩相轮廓具有比较接近的分形维数 ,而不同岩相分形维数相差较大 ,这说明分形理论可用于岩相图像识别与分析。     

背散射电子图像分析在水泥基材料微观结构研究中的应用

自上世纪80年代,国外研究者成功将背散射电子图像分析（backscanered electron imaging and image analysis,BSE．IA）技术应用于水泥基材料微观结构的研究中,在微观定性研究及物相定量分析方面,都获得不同于其他研究方法的研究结果。介绍了BSE-IA技术在水泥基材料研究中的应用...     

Calculating porosity and permeability from synthetic micro-CT scan images based on a hybrid artificial intelligence

Nowadays, lattice Boltzmann is one of the standard and exact methods of simulation in micro-CT images of rock. However, it has a high weakness in run time. Therefore, the effort in this article is to reach a comprehensive substitute method for permeability calculation with less run time than the lattice Boltzmann method. The other purposes are the automation of processing operations, preparation of images, and in the end, the calculation of porosity. The best way to achieve these outcomes is to use hybrid artificial intelligence. In this research work, comprehensive model architecture has been used to design a hybrid artificial intelligence to be able to calculate permeability and porosity in complex images. A thousand images were randomly generated with high complexity, which makes the model comprehensive and extensible, and image processing was applied. After that, the lattice Boltzmann method as the direct simulation was selected. Finally, the convolutional neural network and multilayer perceptron based on a new and comprehensive model were evaluated for the first time; the mean squared error resulting from the evaluation of training data is 0.01, and the test data is 0.03. Expert systems have been used as a subset of artificial intelligence for automated image processing and porosity calculation. In this way, problems related to the direct implementation of classical algorithms for image processing, models, and patterns related to machine learning and needing an expert were solved to an acceptable extent, and an error of less than 5% was achieved.     

Influence of decellularized pericardium matrix on the behavior of cardiac progenitors

Following myocardial infarction, heart muscle has a limited capacity of self‐healing. Biological platforms providing the natural biochemical and biophysical cues of the native myocardium might be crucial to address current therapeutic shortcomings. The aim of this study was to assess the effect of decellularized human pericardium (DPc), as a bioactive platform, on viability, attachment, proliferation and differentiation of human cardiac progenitors (CPs), and evaluate the possibility of using DPc as a substitute of tissue culture polystyrene (TCPS) substrate for culturing CPs in vitro. The decellularization process removed more than 99% of the cellular components from Pc, yet well preserved its macro‐/micro‐structure and extracellular collagen and glycosaminoglycan content. DPc supported the viability, attachment, metabolism and proliferation of CPs, and enhanced their differentiation into mature cardiomyocytes compared to TCPS. Decellularized pericardium appeared thus to have a high potential for cardiac cell culture and could be applied as a superior alternative to common TCPS. DPc could be then utilized for further tissue engineering applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43255.