图像分割评估方法在显微图像分析中的应用

图像分割是计算机视觉领域中的重要分支,旨在将图像分成若干个特定的、具有独特性质的区域。随着计算机硬件计算能力的提高和计算方法的进步,大量基于不同理论的图像分割算法获得了长足的发展。因而选择合适的评估方法对分割结果的准确性和适用性进行综合评估,从而选择最优分割算法,成为图像分割研究中的必要环节。在综述14种图像分割评估指标的基础上,将其分成基于像素的评估方法、基于类内重合度的评估方法、基于边界的评估方法、基于聚类的评估方法和基于实例的评估方法五大类。在材料显微图像分析的应用背景下,通过实验讨论了不同分割方法和不同典型噪声在不同评估方法中的表现。最终,讨论了各种评估方法的优势和适用性。      

Application of fuzzy logic in multicomponent analysis by optodes

Fuzzy logic can be a useful tool for the determination of substrate concentrations applying optode arrays in combination with flow injection analysis, UV-VIS spectroscopy and kinetics. The transient diffuse reflectance spectra in the visible wavelength region from four optodes were evaluated to carry out the simultaneous determination of artificial mixtures of ampicillin and penicillin. The discrimination of the samples was achieved by changing the composition of the receptor gel and working pH. Different algorithms of pre-processing were applied on the data to reduce the spectral information to a few analytic-specific variables. These variables were used to develop the fuzzy model. After calibration the model was validated by an independent test data set.     

Liquidus temperature determination in multicomponent alloys by thermal analysis

Thermal analysis is often used to determine equilibrium phase boundary temperatures such as the liquids. Accurate measurements require proper calibration procedures, which are standard for given instruments. In multicomponent alloys such as RENE N5 and PWA 1484 superalloys, a complex melting behavior associated with the solidification structure was exposed by examining the melting response at different heating rates. The observed variability in the melting signal is related to the sample processing history and is not addressed by the various standard calibration methods or supplemental procedures for different heating rates. The liquidus temperature can be determined under conditions approaching full compositional equilibrium by the application of an interrupted-heating thermal analysis protocol. The approach provides a new strategy for the reliable determination of phase boundary temperatures by thermal analysis.     

Quantitative analysis of a synthetic adjuvant by an immunoassay

The increasing use of molecular fingerprints in the epidemiology of bacterial nosocomial infections urgently demands a computerised analysis and storage of corresponding patterns, especially with regard to results obtained at different times and in different laboratories. This paper presents a database system in connection with cluster analysis of clonal relations by using genomic DNA fragment patterns of S. aureus (SmaI-digestion, pulsed-field gel electrophoresis) as an example: The database is operated under MS-Access, version 2.0. The cluster analysis is based on an optimising similarity algorithm.     

电子探针定量分析轴承钢中碳元素的标准样品研制

电子探针显微分析仪可通过校正曲线法准确地测定质量分数小于1%的钢中微区组织的碳含量。目前,建立校正曲线所使用的标准样品主要为Fe-C合金,鲜有轴承钢标准样品研制及其应用的报道。实验通过真空冶炼得到一组不同碳质量分数(0.180%～0.94%)的轴承钢研究材料,并按国家标准对其稳定性和均匀性进行定量判定,以得到一组适用于校正曲线法定量分析轴承钢中碳含量的标准样品。研究表明,轴承钢研究材料的稳定性和均匀性符合国家标准要求,依据其所建立的校正曲线的线性相关系数为0.979 17,与Fe-C标准样品的校正曲线相比略低。但由于其物理化学性质更接近于实际钢铁产品,其所测得的钢中碳含量更接近于真实值。轴承钢系列标准样品的研制为今后准确测定轴承钢显微组织中碳含量奠定了基础。     

Physiological investigations by image analysis

Cataract formation in diabetic lenses has been attributed to polyol-osmotic pressure-generated influx of water. The ensuing swelling in the form of pocket and lake accumulations cause light scattering. The authors tested whether clear lenses of diabetic patients show different hydration properties than age matched normal lenses. Normal and diabetic human lenses were investigated for their nonfreezable water content by differential scanning calorimetry. The total water content of the lens sections were studied by thermogravimetric analysis. Non-cataractous diabetic lenses in all three regions showed a higher total water content than normal lenses. The nonfreezable water content, seems to increase with age in diabetic lenses and decrease with age in normal human lenses. Thus, hydration changes in human diabetic lenses precede cataract formation. While syneresis, the release of bound water into the bulk, is part of the normal aging process, it appears to occur in the younger diabetics only. In older diabetics syneresis is halted or even reversed. This may be due to the glycation of lens proteins in diabetic patients which tends to immobilize water and therefore, reverse the syneresis due to aging.     

Development of a displacement immunoassay by exploiting cross-reactivity of a monoclonal antibody

An enzyme-linked immunosorbent assay-based displacement assay was developed for the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Advantage was taken of the cross-reactivity of a monoclonal anti-2,4-D antibody toward 2-methyl-4-chlorophenoxyacetic acid (MCPA). MCPA was conjugated with bovine serum albumin (BSA), immobilized on the surface of a microtiter plate, and saturated with the anti-2,4-D antibody. Due to the low affinity of the antibody toward MCPA (cross-reactivity of approximately 30%), the addition of 2,4-D resulted in a displacement of the antibody. Remaining antibodies were subsequently detected using a peroxidase-labeled goat anti-mouse antibody. The detection limit was as low as 0.1 microgram/liter for 2,4-D, which complies with the European Union Drinking Water Directives. When 2,4-D-BSA was used instead of MCPA-BSA conjugates, no significant displacement of bound antibody was observed.     

Quantitative analysis of gel electrophoretograms by image analysis and least squares modeling

A computer-aided quantitative method for a complex analysis of gel electrophoretograms is presented. The analysis consists of several steps: (i) determination of the background image by methods of mathematical morphology and its subtraction from the gel image, (ii) selection of an appropriate part of the gel lane including curved lanes and lanes with a nonuniform width, (iii) computation of the lane densitogram by averaging several lane-parallel scans, (iv) decomposition of the lane densitogram into component bands using a data selecting algorithm and Marquardt's minimizer. Several different functions for component bands are utilized. It is shown that the densitogram can be decomposed into component bands with reasonable accuracy only if an appropriate model function is chosen. The algorithms are tested on several different gel electrophoretograms which show typical features as a nonuniform background, curved lanes, an asymmetrical band shape and a superposition of small bands on the shoulders of big ones. It is shown that overlapped bands are best approximated by an asymmetrical Gausian curve and an asymmetrical Gauss-Cauchy function. Linear response to the serial dilution of the protein sample is tested.     

Shyness and sociability reexamined: A multicomponent analysis.

This research tested questions related to J. M. Cheek and A. H. Buss's (see record 1982-07755-001) prediction that sociability moderates the relation between shyness and dysfunction interaction. In Study 1, a confirmatory factor analysis of Shyness and Sociability scales revealed that these factors are more inversely related than previously recognized. In Study 2, the relations of shyness, sociability, and gender and their interactions with dysfunctional behavior were tested during a conversation with an opposite-sex partner. Using analyses that tested the unique influence of each variable, the results failed to confirm that shy-sociable Ss evidenced more dysfunctional behavior than shy low-sociable Ss. Instead, shyness was the most consistent predictor of behavioral, physiological, and cognitive indexes of anxiety, and shy men were more dysfunctional on some criteria. In particular, shyness differences in perceived visibility of one's nervous behaviors are discussed relative to the role of cognition in shyness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

DNA analysis in hepatoblastoma by flow and image cytometry

BACKGROUND: In several types of tumors, including hepatocellular carcinoma, prognosis could be correlated with DNA ploidy. Few studies have been performed on hepatoblastoma with contradictory results. METHODS: Twenty-nine cases of nonpretreated hepatoblastoma were studied with flow cytometry and image cytometry for DNA index and proliferation index using paraffin-embedded tissue. RESULTS: Twenty-three (79.9%) tumors were diploid, and 6 (20.7%) were aneuploid (hyperdiploid). Patients with diploid tumors were younger than those with aneuploid tumors. With regard to stage, diploid tumors were almost equally distributed among stages (tumor, lymph node metastases, distant metastases), whereas aneuploid tumors tended to occur in higher stages (tumor, lymph node metastases, distant metastases). Diploid tumors had clearly a better prognosis than aneuploid tumors, although the difference was not statistically significant (flow cytometry, P = 0.06; image cytometry, P = 0.16). A more favorable prognosis was also noted for hepatoblastomas with low-proliferation index (< or = 7%), but the difference from tumors with high-proliferation index (> 7%) again was not statistically significant (P = 0.16). CONCLUSIONS: Although no statistically significant differences in prognosis between hepatoblastomas with diploid and aneuploid DNA content, respectively, were found, there is a clear tendency that diploid hepatoblastomas behave more favorably. The same is true for hepatoblastomas with low-proliferation index.     

DNA content and chromatin texture of benzo[a]pyrene-transformed human breast epithelial cells as assessed by image analysis

OBJECTIVE: To determine the relationship between the presence of Ureaplasma urealyticum in the amniotic cavity and adverse maternal and perinatal outcome in women with preterm labor. METHODS: Amniocentesis was performed in 181 patients with preterm labor and intact membranes. Amniotic fluid (AF) was cultured for aerobic and anaerobic bacteria and mycoplasmas. Patients were divided into three groups according to the results of AF culture: those with negative AF cultures (n=160), those with positive AF cultures and in whom the only microbial isolate was U urealyticum (n=11), and those with positive cultures for non-ureaplasmas or mixed microorganisms (n=10). Survival techniques were used for analysis. RESULTS: The prevalence of positive AF cultures in which the only microbial isolate was Uurealyticum was 6.1% (11 of 181), and of positive cultures with non-ureaplasmas or mixed microorganisms was 5.5% (10 of 181). The amniocentesis-to-delivery interval was significantly shorter in patients with positive cultures limited to U urealyticum than in those with negative cultures (median 7 [range 0.1-149] hours versus median 264 [0.1-2659] hours, P < .001). Preterm delivery within 48 hours, 72 hours, and 7 days was more frequent in patients with U urealyticum in the AF than in those with sterile AF (48 hour: 91% versus 33%; 72 hour: 91% versus 36%; 7 days: 100% versus 45%, P < .001 for each). Patients with positive AF cultures limited to U urealyticum had a significantly higher rate of adverse perinatal outcome than those with negative culture. Adverse outcomes included low gestational age at birth, low birth weight, histologic chorioamnionitis, significant neonatal morbidity, and perinatal death. CONCLUSION: Microbial invasion of the amniotic cavity with U urealyticum is a risk factor for impending preterm delivery and adverse perinatal outcome.     

共沉淀法合成三硅酸镁及其微观分析

由Na₂O·nSiO₂和Mg(NO₃)₂经沉淀法合成了三硅酸镁,用450℃煅烧或酸化方法对合成的样品进行改性.采用XRD、IR、TG/DTA和BET等表征手段,考察了原料加入顺序、酸化和煅烧过程对样品的结晶度和表面织构的影响规律,并对其影响机理进行了探讨.结果表明,不同滴定顺序和不同活化方法制得的样品均为非晶态物质.TG/DTA分析显示不同滴定顺序样品的组成相同.pH对样品的表面织构有明显的影响.BET分析表明,Mg(NO₃)₂滴加入泡花碱溶液合成的样品为微孔材料,以1~3nm和0.7~0.9nm的微孔为主,比表面积达568.93m²·g^-1,水合硅酸镁含量较高.泡花碱滴加入Mg(NO₃)₂合成的样品为大孔材料,比表面积为179.40m²·g^-1,水合硅酸镁含量降低.煅烧和酸处理增加样品的结晶度,减少样品比表面积,并改变样品的孔径分布.煅烧使中孔含量增加,形成中孔材料.酸处理使Mg²⁺被H⁺取代,表面形成硅羟基基团,材料以中孔为主.     

Development of cerebellar hypoplasia in jaundiced Gunn rats: a quantitative light microscopic analysis

The homozygous (ii) Gunn rat provides a model for hyperbilirubinemia which includes prominent cerebellar hypoplasia. Development of the Gunn rat cerebellum was examined with and without the additional effects of elevating brain bilirubin concentration to still higher levels via sulfadimethoxine (sulfa) administration. Homozygous (jj) Gunn rats and heterozygous (Nj) littermate controls (n = 32 each) were given 100 mg/kg sulfa or saline at postnatal days 3, 7, 17, and 30, and most were sacrificed 24 h later (n = 4 for each genotype at each age). Cerebellar volume, total volume and cell number for each deep cerebellar nucleus, densities for Purkinje and granule cells in the cerebellar cortex of lobules II, VI and IX, and the density of vacuolated Purkinje cells were all measured quantitatively. Cytoplasmic vacuolation provided an indication of bilirubin toxicity and was never observed in the Nj control rats. Vacuolated Purkinje cells were first observed in jj-saline rats at 18 days and were found only in the more anterior lobules of the cerebellum (II and VI). By contrast, vacuolated Purkinje cells were observed in jj-sulfa rats at both 4 and 8 days, but only in the most posterior cerebellar lobule (IX). In all older jj rats, the decline in vacuolation was accompanied by significant necrosis and resorption of the Purkinje cells in the anterior lobules. Since the Purkinje cells in the posterior lobules are the first to differentiate in the cerebellum and are resistant to bilirubin toxicity in jj-saline rats, the results support the presence of a critical period when elevated brain bilirubin may be most toxic to neuronal development. The findings suggest that neurons undergoing differentiation at the time of bilirubin exposure are most susceptible to cell death, while cells that are slightly more or slightly less mature may show only transient changes.     

美国LECO碳硫分析仪故障分析及检修

介绍美国LECO碳硫分析仪CS600气路分析系统的分析原理和几个故障检修实例。可通过观察碳硫元素释放的峰形图初步判断仪器产生故障的原因。但由于不同原因会产生同一故障现象,因此在检修时需要判断是由仪器传感器故障引起,或是由气路灰尘阻塞引起,还是由气路封闭不严引起的。给出当遇到试样在高频燃烧炉内燃烧熔化不均匀而导致检测元素不能充分释放现象时的处理方法。说明通过故障处理并及时总结经验可以将部分检修工作常规化。     

General method of phase analysis for individual multicomponent alloys

Construction of a complete phase diagram for a 5- (or higher-) component system is so timeconsuming as to be impractical at present. The usual type of information about the phases present, their compositions, and their amounts can be obtained for a particularC-component alloy by the present method:C is the number of components and may be as large as desired. The alloy is brought to an essentially equilibrium condition at the temperature of interest, and the compositions of the phases are determined by a suitable technique; for example, by electronbeam-microprobe analyses of the quenched specimen. The generalized lever law, in determinant form, is used to determine the amounts of the phases. Repetition of this analysis at a second temperature in the same phase region permits identification of the type of variant reaction (pseudoeutectic, and so forth) that is oçcurring. For invariant reactions, a technique such as quantitative metallography is employed to determine the amounts of the phases at an early and a late stage in the reaction. The type of reaction (eutectic, quasiperitectic, and so forth) can then be determined. From experimental data on alloy E an estimate can be made of two aspects of the behavior of a neighboring composition, alloy N; 1) liquidus temperature, and 2) invariant reaction. Thermodynamic procedures should permit useful extensions of the present method.     

In vivo characterization of cytotoxic intracellular edema by multicomponent analysis of transverse magnetization decay curves

The precise measurement of low numbers of leukocyte below 0.1 WBC/microliter in filtered red cell or platelet suspensions meet both aims: to check the compliance with previously determined requirements and to evaluate the performances of novel filtering material (5 log depletion or more), justified by more and more important clinical use. The reliability of results, obtained with the chosen method, is ensured by applying of validation protocol, including training of technologist, assessment of the analytical range and the detection limit, assessment of precision and accuracy. The flow cytometry (FC) and Nageotte Chamber (NC) method are the both techniques which are currently used in routine Quality Control (QC) and validated by multicenter studies. Recent developments are made for increasing the sensibility of these counting methods, thanks to higher concentration or volume of the sample to be analysed. Among the experimental techniques, requiring more advances before implementing in QC program, quantitative PCR must become essential as reference method for evaluating the efficiency of filtration, in the future.     

Development and characterisation of direct laser sintering multicomponent Cu based metal powder

Abstract

Recent advances in direct metal laser sintering (DMLS) have improved this technique considerably; however, it still remains limited in terms of material versatility and controllability of laser processing. In the present work, a multicomponent Cu based metal powder, which consisted of a mixture of Cu, Cu–10Sn and Cu–8·4P powder, was developed for DMLS. Sound sintering activities and high densification response were obtained by optimising the powder characteristics and manipulating the processing conditions. Investigations on the microstructural evolution in the laser sintered powder show that liquid phase sintering with partial or complete melting of the binder (Cu–10Sn), but non-melting of the cores of structural metal (Cu) acts as the feasible mechanism of particle bonding. The additive phosphorus acts as a fluxing agent to protect the Cu particles from oxidation and shows a concentration along grain boundaries owing to the low solubility of P in Cu and the short thermal cycle of laser sintering. A directionally solidified microstructure consisting of significantly refined grains is formed, which may be ascribed to laser induced non-equilibrium effects such as high temperature gradient and rapid solidification.