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为了实验分析单个人正常胃上皮细胞与癌变细胞显微后向散射光谱的区别,结合光纤共聚焦显微成像技术和细胞散射理论,建立了一套基于光纤共聚焦的细胞检测显微光谱分析装置。该装置能够同时获取细胞显微图像和显微光谱医学信息。利用该装置测量了贴壁正常胃上皮细胞GES-1和癌变胃上皮细胞NCI-N87,得到了这两种细胞株细胞水平的显微光谱特性,其光谱具有明显的区别,说明该装置能够在细胞水平上辨别正常和癌变细胞的显微光谱。所得到的正常和癌变胃上皮细胞的显微后向散射光谱曲线与现有单核细胞散射分析结果一致,为以后的细胞水平检测癌变研究提供了必要的基础。 相似文献
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显微光子计数成像系统及其应用 总被引:2,自引:0,他引:2
光子计数成像系统可以探测生物超微弱发光,但是只能探测生物的宏观图像,若要深入到细胞、分子水平,必须有显微光子计数成像系统。二者的区别类于显微光子计数成像系统是噪声受限系统。本文报道的显微光子计数成像系统,采用^14C同位素光源来监测系统的状态,保证实现极限探测。该系统可以用来研究痕量生物分子的分布和功能,显示钙离子在细胞内外的分布,活性氧、基因表达的监测等。由单光子到单分子、组织学图像到功能图像的 相似文献
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人体组织典型参数的获取对于各类疾病的诊断和治疗有着极其重要的作用。采用高性能显微图像测量系统实现人体组织典型参数在体测量, 对系统研制过程中所涉及的基本原理, 以及图像采集系统、成像系统与图像处理软件等关键性技术问题作了阐述。该显微图像测量系统能快速、有效地完成对人体组织典型图像指标的直接测取和定量分析, 基本实现了人体组织典型参数图像观测的数字化与检测的高智能化。实验结果表明, 采用该系统在体观测人体组织典型参数, 可以实时观测人体组织显微图像, 计算并保存毛细血管网络形态学参数和微血流动力学的各项参数, 同时具有快速简单、精确度高等特点, 可作为医学研究的重要手段之一。 相似文献
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《光子学报》2018,(12)
针对动态观察活体细胞形态的数字全息显微应用,提出了一种结合划线拟合和深度学习的自动相位像差补偿方法.首先在全息面提取中心十字线上的物光场相位值,通过二次多项式数值拟合构建相位掩模完成相位像差初步补偿.然后在成像面运用卷积神经网络生成二值化图像掩膜,提取物光场中无物体区域的相位值,再次通过高阶多项式进行数字拟合构建相位掩模完成相位像差精确补偿.最后得到无相位像差的再现相位像.该方法通过在全息面划线取值和数字拟合有效补偿物光中的主要相位像差,降低了成像面物光场的图像轮廓复杂性,利用有限的训练数据集获得能够准确建立图像分割的深度学习模型,从而实现了准确的无需人工干预的数字全息显微自动相位像差补偿.基于离轴数字全息显微成像系统对多种具有不同形态特征的活体细胞开展动态观察实验,并进一步应用该方法进行子宫内膜癌细胞抗药性筛选.结果表明该方法可以很好地用于动态显微观察,从而为生物学细胞动态研究提供实验依据. 相似文献
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因灵敏性高、无损伤和测量速度快等特性,基于3-cube的荧光能量共振转移(E-FRET)显微成像术是目前最流行的活细胞定量FRET成像技术。为了实现活细胞在线实时FRET定量成像,首先提出了一种细胞图像背景自动识别与图像阈值设定的方法:逐像素统计灰度值出现的次数,第1个峰值处的灰度值确定为背景值;将背景值的β(经验常数)倍设为阈值,将扣除背景的供体激发供体探测通道图像和受体激发受体探测通道图像再次扣除阈值,负值置零后进行逻辑与运算制作用于数据筛选的布尔逻辑模板,并将其用于FRET效率和供受体浓度比的数据筛选。利用所提出的方法对转染了不同FRET质粒的细胞进行活细胞在线动态定量E-FRET成像,得到了与期望值一致的测量结果。 相似文献
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低温等离子体技术与生物医学似乎是两种风马牛不相及的事物,可是两者的结合却可以对现代科技发展产生重要的影响.许多人都认为21世纪是生物技术的世纪,可见人们对生物技术发展抱着怎样的期待.低温等离子体技术正在成为生物材料和生物医学器件的生产和研究的广阔的平台.文章简要介绍了一些用于材料表面改性的技术以及低温等离子体技术在生物医学方面的应用,并进而讨论了将低温等离子体技术与生物技术相结合的途径以及还需要解决的问题.文章还详细讨论了一种用于表面功能化的脉冲等离子体技术方法作为二者最佳结合的一个典范.文章最后指出,生物医学与等离子体技术的完美结合可能对21世纪的科技发展产生革命性的影响;而为了实现这个目标。需要多学科专家的通力合作. 相似文献
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T. Neumann P. Wagner 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(2):255-264
A simple cellular automaton to model traffic flow is used to analyze the impact of traffic lights on travel times. The model
is investigated on a stretch of road with open boundaries, where the inflow is driven stochastically, but the outflow is controlled
by a traffic light with periodically changing outflow rates. Especially in the transition regime from free flow to oversaturated
flow, the detailed space-time structure can be used to derive analytical lower and upper boundaries for the travel time function.
The analytical results have been verified by a simulation study. The function displays a strong non-trivial dependency on
the length of the system, which is at odds with a well-known formula derived almost 50 years ago by Webster. Such a model
is interesting both from a theoretical point of view and for applications. 相似文献
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The influence of immersion and contact ultrasound treatment on selected properties of the apple tissue 总被引:1,自引:0,他引:1
Artur Wiktor Magdalena SledzMalgorzata Nowacka Katarzyna RybakDorota Witrowa-Rajchert 《Applied Acoustics》2016
Ultrasound (US) treatment is considered to be one of the most promising non-thermal technology used in the food processing. The food-related applications of this technique are linked to the analytical and technological purposes. The ultrasound waves in the food can cause the formation of micro-channels due to the systematic and alternating compression and decompression of the material (so called “sponge effect”). Additionally, in liquids the ultrasound application can cause the cavitation which can modify the food properties as well. Hence, due to its mechanism, the ultrasound treatment can also improve the extraction of pigments, aromas or antioxidants from the food matrices. 相似文献
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Weak avalanche multiplication in SiGe heterojunction bipolar transistors on thin film silicon-on-insulator 下载免费PDF全文
In this paper, we propose an analytical avalanche multiplication model for the next generation of SiGe silicon-on-insulator (SOI) heterojunction bipolar transistors (HBTs) and consider their vertical and lateral impact ionizations for the first time. Supported by experimental data, the analytical model predicts that the avalanche multiplication governed by impact ionization shows kinks and the impact ionization effect is small compared with that of the bulk HBT, resulting in a larger base-collector breakdown voltage. The model presented in the paper is significant and has useful applications in the design and simulation of the next generation of SiGe SOI BiCMOS technology. 相似文献
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Topology optimization is a computational tool that can be used for the systematic design of photonic crystals, waveguides, resonators, filters and plasmonics. The method was originally developed for mechanical design problems but has within the last six years been applied to a range of photonics applications. Topology optimization may be based on finite element and finite difference type modeling methods in both frequency and time domain. The basic idea is that the material density of each element or grid point is a design variable, hence the geometry is parameterized in a pixel‐like fashion. The optimization problem is efficiently solved using mathematical programming‐based optimization methods and analytical gradient calculations. The paper reviews the basic procedures behind topology optimization, a large number of applications ranging from photonic crystal design to surface plasmonic devices, and lists some of the future challenges in non‐linear applications. 相似文献
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Applications of near-infrared spectroscopy to process analysis using fourier transform spectrometer 总被引:1,自引:0,他引:1
Masahiro Watari 《Optical Review》2010,17(3):317-322
The applications of near-IR spectroscopy to process analysis using a Fourier transform spectrometer are described. In recent
years, process analysis based on near-IR spectroscopy has received keen interest from a growing number of industries. Some
configurations of Fourier transform near infrared (FT-NIR) interferometers used for process analysis are introduced as special
optical systems for the realization of stable and reproducible performance. Moreover, the applications of NIR spectroscopy
to process analysis using FT-NIR spectrometers are overviewed and two examples of applications are described in more detail.
Furthermore, process analytical technology (PAT) for the pharmaceutical industry is introduced as a future trend of the application
of FT-NIR spectroscopy, and a dual-wavelength system that can combine NIR and IR spectra is discussed as a newly proposed
PAT tool for understanding processes. 相似文献
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In this paper, we address the issue of cellular OFDMA network dimensioning. Network design consists of evaluating cell coverage and capacity and may involve many parameters related to environment, system configuration, and quality of service (QoS) requirements. In order to quickly study the impact of each of these parameters, analytical formulas are needed. The key function for network dimensioning is the Signal to Interference Ratio (SIR) distribution. We thus analyze in an original way the traditional issue of deriving outage probabilities in OFDMA cellular networks. Our study takes into account the joint effect of path-loss, shadowing, and fast fading effects. Starting from the Mean Instantaneous Capacity (MIC), we derive the effective SIR distribution as a function of the number of sub-carriers per sub-channel. Our formula, based on a fluid model approach, is easily computable and can be obtained for a mobile station (MS) located at any distance from its serving base station (BS). We validate our approach by comparing all results to Monte Carlo simulations performed in a hexagonal network, and we show how our analytical study can be used to analyze outage capacity, coverage holes, and network densification. The proposed framework is a powerful tool to study performances of cellular OFDMA networks (e.g. WiMAX, LTE). 相似文献
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X射线光谱现场分析技术是在现场工作条件下对待测目标体中元素进行快速定性和定量分析的仪器分析技术,被广泛应用于一些大型分析仪器和化学分析方法所不能直接应用的领域。该文回顾了近二十年来我国X射线光谱现场分析技术的研究进展。从现场原位分析和现场取样分析两个角度,评述了现场X射线光谱仪的研究进展和主要技术特征;探讨了X射线光谱现场分析数据处理的关键技术问题,概括了X射线仪器谱解析方法的创新性和演变规律;介绍了我国现场X射线光谱分析在地质普查、环境污染调查、文物现场鉴定、合金分析中的重要应用;评价了国际上X射线光谱现场分析仪的研究现状和进展。提出了X射线光谱现场分析技术的研究方向,以期在更多的应用领域得到长足发展。 相似文献