激光共聚焦显微成像技术在植物细胞微丝骨架三维动态观察中的应用

激光扫描共聚焦显微镜(laser scanning confocal microscope,LSCM)是目前生物学领域应用最广泛、分辨率高的仪器。可用于细胞内形态结构观察及三维重建、组分空间定位、实时动态变化监测等研究,图像分析软件还能提供荧光强度、空间距离定量测定的丰富信息。本文以携带GFP融合拟南芥丝束蛋白1(AtFIM1)的肌动蛋白结合结构域2(fABD2)基因的B Y-2转基因细胞系为材料,运用LSCM技术观察到间期细胞的网络状微丝结构并重构出胞内微丝的三维网络结构;实时动态监测细胞有丝分裂过程中微丝骨架的动态变化;通过细胞内荧光强度的分布直观地看出BY-2细胞胞质分裂过程中微丝骨架的动态变化。这些结果显示出LSCM在研究植物细胞微丝骨架的三维网络动态结构及图像荧光强度分析与统计方面的优越性。     

万能工具显微镜的三维改造

随着科技的创新与进步,传统二维测量技术已经满足不了现在高效率自动化检测的需求,急需新型的三维测量技术。万能工具显微镜作为传统用途广泛、准确度较高和故障率很低的精密测量仪器,目前国内现存量很大,急需对其进行三维自动化改造。该文在万能工具显微镜的基础上,增加3个光栅位移测量系统、自动控制系统以及数据采集分析系统,使其能够实现三维自动测量。     

激光扫描共聚焦显微镜技术的发展及应用

激光扫描共聚焦显微术是先进的分子和细胞生物学研究技术。它在荧光显微镜成像的基础上加装激光扫描装置,结合数据化图像处理技术,采集组织和细胞内荧光标记图像。在亚细胞水平观察钙等离子水平的变化,并结合电生理等技术观察细胞生理活动与细胞形态及运动变化的相互关系。由于它的应用范围较广泛,已成为形态学、分子细胞生物学、神经科学和药理学等研究领域中很重要的研究技术。     

基于多图像融合的MEMS显微三维形貌重构

针对微型机电系统(MEMS)的三维测量,显微镜或光学轮廓干涉仪等传统方法存在显微测量精度低、设备成本高等问题,且当结构含有较多断裂面时,解包裹算法效果欠佳。本文提出一种基于多图像融合的MEMS显微三维测量方法。不同于多角度显微三维测量方法,本研究首先利用单目显微镜,通过单一轴向移动获取一系列测量目标深度信息的单一角度图像,并利用去雾算法对图像进行预处理,实现了去噪和有效信息提取的目的;然后通过聚焦测度算法获取待测对象的深度信息;最后利用数据处理软件进行三维拟合。基于上述原理,本文以焦平面阵列(FPA)作为待测目标进行了测量实验。本文提出的三维测量方法和图像处理算法可获得更准确的FPA形貌,可清晰显示反射面与支腿部分及反射面上的释放孔,测得FPA的支腿长度为110.6μm,每个反射面的像元尺寸为120.8μm×70.8μm,与设计值基本吻合,解决了断裂面难以测量的问题,同时降低了微结构测量的难度和成本。单目显微镜单向移动的多图像融合测量技术对MEMS的三维形貌测量具有重要意义,去雾算法在图像融合与三维测量的图像处理也有很好的应用价值。     

聚焦离子束电子束系统及其在生物学和医学上的应用

聚焦离子束电子束系统在材料失效分析、纳米材料结构表征与性能分析以及纳米器件研制等方面发挥着重要作用。近年来该系统在生物学和医学领域的应用日益受到人们的重视。本文介绍聚焦离子束电子束系统的组成、性能、相关功能及其在生物学和医学上的若干应用,包括透射电镜生物样品制备、细胞和组织内部结构观察与三维重构等。     

不同清洗剂对三维打印性能的影响分析

应用粘结剂喷射三维打印技术制备316L不锈钢试块,通过金相组织观察、显微维氏硬度和布氏硬度测试、室温拉伸试验、抗压试验、致密度测试等,对比两种不同清洗剂对三维打印性能的影响。通过优化清洗剂配比,得到适用于316L不锈钢三维打印的清洗剂最佳配比,改善三维打印表面质量,将丢帧数控制在合理范围内。     

一种新颖的微机电系统微结构显微图像三维自动拼接方法

提出一种基于白光垂直扫描显微镜(White-light vertical scanning interference microscopy,WVSIM)的微机电系统(Micro electro mechanical systems,MEMS)微结构三维自动拼接方法,来获得包含完整MEMS信息的大视场、高分辨率的MEMS微结构显微图像,以满足MEMS微结构功能特征分析、评定的需要。通过分析白光垂直扫描显微成像原理,将MEMS微结构显微图像的三维拼接分解为x-y向拼接与z向高度校正。将二维图像配准的尺度不变特征变换特征匹配算法应用到MEMS微结构显微图像的三维拼接中,实现MEMS微结构显微图像的智能、鲁棒三维自动拼接。试验表明,该方法不需要超高精度的硬件,解决了任意形状MEMS微结构显微图像的高精度三维自动拼接问题。横向拼接精度可达0.8μm,纵向拼接精度小于1 nm。     

混合显微镜可从三维测量生物分子

<正>据每日科学不久前报道,最近,美国爱荷华大学与国家能源部艾米实验室科学家合作,将光学显微与原子力显微技术结合起来,开发出一种能对单个生物分子进行三维测量的方法,准确性和精确性都达到纳米级别。最近出版的《纳米快报》上详细介绍了该技术。     

计算机微视觉的三维显微测试及构形系统的研究

微结构三维显微测量是研究微加工工艺和微尺度结构特性的主要测试手段.一种基于计算机微视觉的方法被提出用来对三维微结构进行显微测量.对微结构测试及构形系统的基本原理进行了研究,构建了微结构测试及构形系统的硬件和软件平台.从而实现了在光学显微镜下对微结构的三维观测[0].通过运用微结构测试及构形系统的硬件平台实现了对微结构高分辨率的观察测量、三维精确运动控制以及水平与竖直方向的精确制动.通过软件平台完成了对微结构的三维重构.课题利用微结构测试及构形系统对微结构进行了测试及重构.通过实验,证明了理论研究和系统的可行性,该研究在微结构的测试方面具有较大的理论意义和实用价值.     

一种新型便携定量相位显微镜的研发

为了解决现有显微镜存在的问题,研发了一种新型可便携定量相位显微镜.首先简述了定量相位显微成像系统的设计思路和工作原理;然后利用UG NX 10.0软件对定量相位显微镜进行三维设计;再基于三维打印的方式对其进行加工制造;最后对其进行组装.结果表明,该可便携定量相位显微镜能够成功拍摄出干涉图像,达到相应的预期设计目标.     

显微高光谱成像系统的设计

设计出一种基于棱镜 光栅 棱镜组合分光方式的显微高光谱成像实验系统.系统根据推帚式成像光谱仪的原理进行设计,采用棱镜 光栅 棱镜组合元件在后光学系统进行光谱分光,利用高精度载物台自动装置驱动样品进行推扫成像,选用PCI总线作为数据采集的微机接口.整个系统由显微镜、分光计、面阵CCD相机、载物台自动装置以及数据采集与控制模块等几部分组成.系统的光谱范围从400nm到800nm,120个波段,光谱分辨率优于5nm,空间分辨率大约1μm.该系统具有直视性、光谱分辨率高、结构紧凑、成本低等优点;不仅能够提供微小物体在可见光范围的单波段显微图像,而且能够获得图像中任一像素的光谱曲线,实现了光谱技术和显微成像技术的结合,成功的将成像光谱技术应用到显微领域,可广泛应用于临床医学、生物学、材料学、微电子学等学科领域.     

Restoration of confocal images for quantitative image analysis

Quantitative studies of three-dimensional (3-D) structure of microscopic objects have been made possible through the introduction of microscopic volume imaging techniques, most notably the confocal fluorescence microscope (CFM). Although the CFM is a true volume imager, its specific imaging properties give rise to distortions in the images and hamper subsequent quantitative analysis. Therefore, it is a prerequisite that confocal images are restored prior to analysis. The distortions can be divided into several categories: attenuation of areas in the image due to self-absorption, bleaching effects, geometrical effects and distortions due to diffraction effects. Of these, absorption and diffraction effects are the most important. This paper describes a method aimed at the correction of diffraction-induced distortions. All the steps necessary in restoring confocal images are discussed, including a novel method to measure instrumental properties on a routine basis. To test the restoration procedure an image of a fluorescent planar object was restored. The results show a considerable improvement in the z-resolution and no ringing artefacts. The relevance of the method for image analysis is demonstrated by a comparison of results of applying 3-D texture analysis to restored and unrestored images of a synthetic object. Furthermore, the method can be successfully applied to noisy fluorescence images of biological objects, such as interphase cell nucei.     

Microscopic and spectroscopic characterization of rice and corn starch

Starch granules from rice and corn were isolated, and their molecular mechanism on interaction with α‐amylase was characterized through biochemical test, microscopic imaging, and spectroscopic measurements. The micro‐scale structure of starch granules were observed under an optical microscope and their average size was in the range 1–100 μm. The surface topological structures of starch with micro‐holes due to the effect of α‐ amylase were also visualized under scanning electron microscope. The crystallinity was confirmed by X‐ray diffraction patterns as well as second‐harmonic generation microscopy. The change in chemical bonds before and after hydrolysis of the starch granules by α‐ amylase was determined by Fourier transform infrared spectroscopy. Combination of microscopy and spectroscopy techniques relates structural and chemical features that explain starch enzymatic hydrolysis which will provide a valid basis for future studies in food science and insights into the energy transformation dynamics.     

运用碳纳米管原子力显微镜针尖减小长程力作用的研究

减小探针和样品表面之间的长程宏观力是原子力显微镜获得高分辨率成像的关键。首先通过理论分析得出影响长程力的主要因素是探针的几何形状和尺寸。然后分别运用几何形状和尺寸不同的原子力显微镜的传统Si针尖和碳纳米管针尖对样品进行扫描试验研究,结果显示碳纳米管针尖较传统针尖获得了高分辨率的图像。这一结果表明,碳纳米管针尖减小了成像中宏观长程作用力的影响,是理想的原子力显微镜针尖。     

Contour extraction of a laser stripe located on a microscope image from a stereo light microscope

A stereo light microscope has a special optical structure that consists of two optical paths. With two cameras fitted on its imaging planes, a microscopic binocular vision system can be constructed, and this system can be applied in three‐dimensional (3D) shape measurements of a microscopic object. A novel‐shape reconstruction system is developed in this article composed of laser fringe scanning and a stereo light microscope. A laser projector emits a thin light sheet and projects it onto the microscopic object's surface. The microscopic object is placed on a micro‐displacement mechanism and moved in a given direction. The entire surface of the object is scanned by the light sheet. This system captures a series of microscopic images of the laser stripe, which are used to restore the 3D shape of the object. In this article, we mainly focus on the study of the laser stripe detection method, which is derived based on the Canny rule. First, the Canny rule outputs pixels at the left and right edges of the laser stripe. Then, a subpixel edge extraction method is proposed based on polynomial fitting that outputs the center curve of the laser stripe. Finally, an edge filter is used to smooth the edge burrs, and the Hermite interpolation method is used to link the broken edges and construct continuous, smoothing edge contours. The results show that this method can effectively find the subpixel position of the laser stripe and output high‐quality edge contours. The method is suitable for extracting the contours of a laser stripe located in a microscope image.     

Image formation in scanned heterodyne microscope systems

Several new scanning microscopic techniques have recently been developed which rely on modulation of the optical beam to enhance the imaging performance. These systems have the common feature that the image is formed by detection or demodulation of an a.c. signal. Techniques have been developed which are sensitive to both intensity and phase information in the sample. We refer to such microscopes as heterodyne imaging systems (and by analogy single-frequency microscopes, operating at d.c. only, are referred to as homodyne) although as we will point out this term is only strictly applicable to the interferometric-based methods. Although the theory for the conventional homodyne scanning optical microscope is well developed there has been no systematic study of heterodyne microscopic techniques, which is the purpose of this paper. Several techniques are discussed and compared and the different ways of extracting amplitude and phase information are considered in detail with reference to experimental systems which have been demonstrated to have good imaging performance.     

计算机化医学影像仪器的发展

医学影像学的发展非常迅速,本文总结医学影像仪器的发展,X线成像仪器,CT成像技术设备的基本结构,MR I的基本设备结构,CR的结构及PACS系统结构。这些仪器设备都与计算机联用,实现计算机化。     

三维显微图像带约束的迭代解卷积复原算法

阐述显微镜透明厚样本成像原理和三维显微图像带约束的迭代解卷积复原算法。根据显微镜透明厚样本成像原理,对已知三维清晰图像进行退化处理,并且使用带约束的迭代解卷积算法去除退化图像中的散焦信息。试验结果表明,图像散焦信息的干扰得到有效的去除,清晰度和信噪比得到明显的改善,并且该算法可以恢复成像过程中丢失的部分频率成分,实现超分辨率复原。当迭代次数较大时,复原效果优于邻域法和线性方法。     

面向细胞显微成像的虚拟染色技术的研究

细胞显微成像是生物学研究中进行细胞表型检测、获取细胞特征信息的重要手段。传统荧光成像技术是目前主要的细胞成像手段，但是荧光成像系统结构复杂、成本较高，而且特异性染色会对细胞造成损伤。针对此问题，研究了一种虚拟染色技术，使用多模态配准算法执行严格配准明场和荧光图像数据集，改进网络架构、损失函数、后处理、硬件适应性用于训练优化，并且通过虚拟染色评价标准对染色转换偏差进行验证。该方法可以降低荧光成像对荧光成像设备的依赖，无需各种复杂的染色操作，将会减轻生物研究、病理分析、疾病诊断流程的负担。     

Real imaging and size values of Saccharomyces cerevisiae cells with comparable contrast tuning to two environmental scanning electron microscopy modes

The combined application of electron microscopy (EM) is frequently used for the microstructural investigation of biological specimens and plays two important roles in the quantification and in gaining an improved understanding of biological phenomena by making use of the highest resolution capability provided by EM. The possibility of imaging wet specimens in their "native" states in the environmental scanning electron microscope (ESEM) at high resolution and large depth of focus in real time is discussed in this paper. It is demonstrated here that new features can be discovered by the elimination of even the least hazardous approaches in some preparation techniques, that destroy the samples. Since the analysis conditions may influence the morphology and the extreme surface sensitivity of living biological systems, the results obtained from the same cultured cell with two different ESEM modes (Lvac mode and wet mode) were compared. This offers new opportunities compared with ESEM-wet/Lvac-mode imaging, since wet-mode imaging involves a real contrast and gives an indication of the changes in cell morphology and structure required for cell viability. In this study, wet-mode imaging was optimized using the unique ability of cell quantities for microcharacterization in situ giving very fine features of topological effects. Accordingly, the progress is reported by comparing the results of these two modes, which demonstrate interesting application details. In general, the functional comparisons have revealed that the fresh unprocessed Saccharomyces cerevisiae cells (ESEM-wet mode) were essentially unaltered with improved and minimal specimen preparation timescales, and the optimal cell viability degree was visualized and also measured quantitatively while the cell size remained unchanged with continuous images.