Effect of an annular pupil filter on differential confocal microscopy

Combining differential confocal microscopy and an annular pupil filter, we obtained the normalized axial intensity distribution curve of an optical system. We used the sharp slopes of the axial response curve of the optical system to measure the surface profile of a reflection grating. Experimental results prove that this method can extend the axial dynamic range and improve the transverse resolution of three-dimensional profilometry by sacrificing axial resolution. (C) 2000 Optical Society of America.

The intensity distributions of collected signals in coherent anti-Stokes Raman scattering microscopy

Coherent anti-Stokes Raman scattering (CARS) microscopy with the combining of confocal and CARS techniques is a remarkable alternative for imaging chemical or biological specimens that neither fluoresce nor tolerate labeling. The CARS is a nonlinear optical process, the imaging properties of CARS microscopy will be very different from the conventional confocal microscopy. In this paper, we calculated the propagation of CARS signals by using the wave equation in medium and the slowly varying envelope approximation (SVEA), and find that the intensity angular distributions vary considerably with the different experimental configurations and the different specimen shapes. So the conventional description of microscopy (e.g.. the point spread function) will fail to descript the imaging properties of CARS microscopy. (c) 2004 Elsevier B.V. All rights reserved.

激光扫描共聚焦显微镜在蛋白质晶体生长研究中的应用

激光扫描共聚焦显微镜与普通光学显微镜相比，其分辨率高，同时具有可对样品进行非侵入性无损伤断层扫描，以及对样品形貌进行三维成建等特点，因此，可作为研究晶体生长强有利的工具。本文介绍了其在定量测量晶体的个数，重组三维图像以获得晶体生长的过程信息及测定晶体生长台阶动态变化等方面的应用。还对激光扫描共聚焦显微镜在晶体生长研究的其它方面应用前景作了展望。

Direct observation of adsorption sites of protein impurities and their effects on step advancement of protein crystals

We measured noninvasively step velocities of elementary two-dimensional (2D) islands on {110} faces of tetragonal lysozyme crystals, under various supersaturations, by laser confocal microscopy combined with differential interference contrast microscopy. We studied the correlation between the effects of protein impurities on the growth of elementary steps and their adsorption sites on a crystal surface, using three kinds of proteins: fluorescent-labeled lysozyme (F-lysozyme), covalently bonded dimers of lysozyme (dimer), and a 18 kDa polypeptide (18 kDa). These three protein impurities suppressed the advancement of the steps. However, they exhibited different supersaturation dependencies of the suppression of the step velocities. To clarify the cause of this difference, we observed in situ the adsorption sites of individual molecules of F-lysozyme and fluorescent-labeled dimer (F-dimer) on the crystal surface by single-molecule visualization. We found that F-lysozyme adsorbed preferentially on steps (i.e., kinks), whereas F-dimer adsorbed randomly on terraces. Taking into account the different adsorption sites of F-lysozyme and F-dimer, we could successfully explain the different effects of the impurities on the step velocities. These observations strongly suggest that 18 kDa also adsorbs randomly on terraces. Seikagaku lysozyme exhibited a complex effect that could not alone be explained by the two major impurities (dimer and 18 kDa) present in Seikagaku lysozyme, indicating that trace amounts of other impurities significantly affect the step advancement.

Noninterferometric measurement of lead zirconate titanate inverse piezoelectric extension

A noncontacting and noninterferometric depth discrimination technique, which is based on differential confocal microscopy, was used to measure the inverse piezoelectric extension of a piezoelectric ceramic lead zirconate titanate actuator. The response characteristics of the actuator with respect to the applied voltage, including displacement, linearity, and hysteresis, were obtained with nanometer measurement accuracy. Errors of the measurement have been analyzed. (C) 2001 Society of Photo-Optical Instrumentation Engineers.

Designing superresolution optical pupil filter with constrained global optimization algorithm

In this paper, a new method for designing three-zone optical pupil filter is presented. The phase-only optical pupil filter and the amplitude-only optical pupil filters were designed. The first kind of pupil for optical data storage can increase the transverse resolution. The second kind of pupil filter can increase the axial and transverse resolution at the same time, which is applicable in three-dimension imaging in confocal microscopy. (C) 2007 Elsevier GmbH. All rights reserved.

R6G单分子表面增强共振拉曼散射光谱探测研究

以共焦显微系统为平台，研究了不同浓度的R6G银溶胶的表面增强共振拉曼散射（SERRS）光谱，结果表明不同浓度溶液中的R6G分子表现出了不同的光谱特性。在浓度为10^-13mol·L^-1的R6G银溶胶中得到了R6G单分子的表面增强共振拉曼散射光谱，观察到了一些光谱非均匀变化现象，如谱色散、谱线的强度起伏、拉曼谱的偏振化以及分子的闪烁等，并对这些现象进行了分析，证明得到的是R6G单分子的SERRS光谱。文章还对单分子检测中的一些关键问题进行了分析与讨论，确定了单分子SERRS光谱检测的适当条件。

共焦扫描系统扫描深度与厚度失真分析

采用几何光学方法对共焦系统扫描时产生的扫描深度与厚度失真进行了理论分析，对名义扫描深度与实际扫描深度之间的关系进行了研究．以若丹明6G薄膜与玻片组成的多层样品为模型，对其进行了模拟计算，得到了扫描深度与厚度失真与系统数值孔径、折射率和样品厚度之间的关系．在实验上分别采用单光子荧光和双光子荧光作为检测信号，在反射式共焦扫描系统上进行了纵向扫描实验，并与模拟计算的结果进行了比较和分析．

Relationship between trichosanthin cytotoxicity and its intracellular concentration

Trichosanthin (TCS) is a type I ribosome-inactivating protein with board spectrum of biological activity. Toxicity of this compound differs in different cell lines and this study examined the cause of such difference. It is generally believed that TCS toxicity is mediated through intracellular ribosome inactivation. Therefore, TCS toxicity should be determined by the amount inside cells rather than outside. Three different cell types IC21, JAR and Vero cell lines were chosen with high, medium and low sensitivity to TCS. Intracellular concentrations of fluorescein isothiocyanate labeled TCS were determined by laser scanning confocal microscopy. A good relationship was demonstrated between intracellular TCS concentration and toxicity. Highest intracellular concentration was found in IC21, followed by JAR, and lowest in Vero cells. When the intracellular TCS concentrations in these cells were reduced by using a competitive inhibitor to block cell entry, cytotoxicity was not observed. In conclusion, there is strong evidence to indicate that cytotoxicity of TCS is dependent on its intracellular concentration. Variation of cytotoxicity in different cells may be related to the mechanisms affecting its internalization. (C) 2002 Published by Elsevier Science Ireland Ltd.

口腔移植材料与成骨细胞相容性的激光共聚焦显微镜观察

下载PDF阅读器目的:观察不同处理的钛金属表面与成骨细胞的生物相容性.方法:利用共聚焦显微镜荧光信号通过物镜返回光电倍增管成像的原理,获取不透光的钛金属表面图像,对钛金属表面(打磨、喷砂、喷砂酸蚀表面)接种的成骨细胞骨架进行荧光标记,并用共聚焦显微镜获取荧光图像,观察细胞和钛金属表面的生物相容性,并且通过逐渐深入的多层扫描,探索细胞和移植材料结合的进一步信息.结果:喷砂表面适合成骨细胞的贴附和生长.结论: 钛金属与成骨细胞的结合情况主要与金属表面的物理形态有关.

Characterization of the Rana grylio virus 3 beta-hydroxysteroid dehydrogenase and its novel role in suppressing virus-induced cytopathic effect

The 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) isoenzymes play a key role in cellular steroid hormone synthesis. Here, a 3 beta-HSD gene homolog,was cloned from Rana grylio virus (RGV), a member of family Iridoviridae. RGV 3 beta-HSD gene has 1068 bp, encoding a 355 aa predicted protein. Transcription analyses showed that RGV 3 beta-HSD gene was transcribed immediate-early during infection from an initiation site 19 nucleotides upstream of the translation start site. Confocal microscopy revealed that the 3 beta-HSD-EGFP fusion protein was exclusively colocalized with the mitochondria marker (pDsRed2-Mito) in EPC cells. Upon morphological observation and MTT assay, it was revealed that overexpression of RGV 3 beta-HSD in EPC cells could apparently suppress RGV-induced cytopathic effect (CPE). The present studies indicate that the RGV immediate-early 3 beta-HSD gene encodes a mitochondria-localized protein, which has a novel role in suppressing virus-induced CPE. All these suggest that RGV 3 beta-HSD might be a protein involved in host-virus interaction. @ 2006 Elsevier Inc. All rights reserved.

A new potential radiosensitizer- multi-walled carbon nanotubes modified by ammonium persulfate

Here we prepare carbon nanotubes modified with ammonium persulfate, very short carbon nanotubes with 50-100 nanometer length was obtained, and the higher P potential of 52 mV was detected, these supporting the successful modification. HeLa cells were irradiated with P rays via adding or absent above functionalized carbon nanotubes (f- WCNTs) into cell culture medium with different concentration and radiation dosage. Confocal microscopy images and fluorescence-labeled DNA detection verified the successfully pure multi-walled carbon nanotubes (p-WCNTs) and f-WCNTs penetrated into cells. Compared with pure radiation, by MTT test, f-WCNTs induced cell death markedly with about 8.7 times higher than former one under little dose of radiation; meanwhile, no obvious toxicity was observed both in p-WCNTs and f-WCNTs without of radiation exposure. We hypothesized that large amount of hydroxyl and carbonyl organs on the surface of very short f-WCNTs changed into free radicals result from radiations led cell damage. These implied that f-WCNTs could be regarded as a new radiosensitizer.

Characterization of structure and diffusion behaviour of Ca-alginate beads prepared with external or internal calcium sources

Ca-alginate beads were prepared with either external or internal calcium sources. The structures of both beads were investigated with the aid of scanning electron microscopy (SEM) and confocal microscopy. It was shown that the beads with internal calcium source had a looser structure and bigger pore size than those with external calcium source. The attempts to interpret the difference were carried out by determining the Ca content within the beads at various times, which indicated that it was the different gelation mechanisms that caused the difference of structures of both beads. Furthermore, it was also found that the diffusion rate of haemoglobin (Hb) within the beads with an internal calcium source was faster than that of the beads with an external one, which was consistent with the observation of their structures.