含水生物样品的环境扫描电镜观察

目前，在常规的扫描电镜中观察含水的生物样品有两种方法：（１）用戊二醛和锇酸固定细胞的骨架，再用乙醇脱水，二氧化碳临界点干燥后喷金，然后放入扫描电镜观察。（２）样品深度冷冻后使用冷冻样品台放入扫描电镜观察。以上两种制备方法都会使样品失去原来的自然面貌。...     

生物样品的环境扫描电镜观察

用环境扫描电镜观察动物、植物、微生物等生物样品。通过对环境条件的比较 ,发现样品温度 4～ 6℃ ,样品室气压 6 93× 10 2 ～ 7 86× 10 2 Pa,相对湿度 85%是合适的环境条件 ,在这一条件下 ,多数生物样品既不发生表面凝聚水滴也不发生脱水 ,而且死后变化小 ,没有充放电现象 ,能获得满意的结果。本文还对不同生物样品的实验方法以及环境扫描电镜的应用前景进行了讨论     

避免扫描电镜生物样品污染方法

一个制备良好的扫描电镜生物样品应该是细胞保存良好 ,结构清晰 ,无污染 ,导电性能好 ,立体感强。样品制备方法很多 ,由于生物组织结构的不同 ,在制样中如何防止样品的污染 ,是确保电镜观察效果的一个重要问题。在实践中 ,我们认为样品制备过程中 ,如果能注意以下的问题 ,会取得更好的结果。正确取材取材是生物样品制备的第一步 ,也是很重要的一步。除了按常规的方法取材外 ,还应根据不同组织的特点 ,采取不同的处理方法 ,才能得到满意的观察效果。1 .一般的实质性组织可按常规取材要求 ,将样品切成长度和宽度 <7ｍｍ ,厚度 <4ｍｍ的长方体…     

液体样品的环境扫描电镜观察

环境扫描电镜的应用大大拓宽了常规扫描电镜的应用范围，对于绝缘样品不需要镀膜、含油含水的固体样品不需要干燥以及液体样品都可以直接放入样品室进行观察，因而能够反映样品原始形貌，不破坏样品原始结构。对于生物等样品的观察简便迅速，减少了样品制备之苦；对于液体...     

环境扫描电镜对亲水高分子材料的原位观察

20世纪80年代发展起来的环境扫描电镜（environmental seanning eleclron microseope,ESEM）,可直接观察各类非导电材料，而不必对样品表面进行喷镀导电膜，ESEM更为重要的特点是可实现对含水、含油、放气等类样品的原位和动态观察，获得样品自然状态下的真实微观特征，或反应过程中的变化。     

一种快速简便的扫描电镜样品制备法

一种快速简便的扫描电镜样品制备法李向党（西安第四军医大学电镜室，西安７１００３２）为了研究生物样品凹凸不平的立体结构，通常需要使用扫描电镜的样品制备技术，常规扫描电镜的样品制备技术所需时间长，操作复杂，仪器昂贵，基层单位无法承受。我们现采用六甲基二硅...     

微波辐射扫描电镜生物样品制备方法

近几年来,微波辐射(MW)被成功地引入光镜、电镜和免疫组织化学等生物样品制备和研究,受到国内外电镜工作者的关注。本文将MW引入扫描电镜生物样品制备的各个过程,进行了一系列对比实验,旨在获得MW扫描电镜生物样品制备的适宜条件和方法。实验材料为交链孢子(Alternaria Sp.)和小白鼠气管。使用广东蚬华产家用微波炉。工作频率2450MHz,最大输出功率700W,10档可调。在炉内中央放置一个直径10厘米玻璃培养器,内装200毫升水。将装有2毫升浸泡液和试样的青霉素小瓶放在培养器中,温度探测棒浸入水中监测水温。功率输出选第一档(370W),进行定     

扫描电镜生物样品表面不同镀膜方法的比较

扫描电镜生物样品表面不同镀膜方法的比较张雅坤边晓燕张莉＊王丽英（哈尔滨医科大学电镜室＊哈医大二院，哈尔滨１５００８６）扫描电镜生物样品制备技术中，样品表面的导电化处理是建立图像反差，获得良好的高倍率，高分辨电子图像的主要环节。目前，多数实验室采用单纯...     

几种扫描电子显微镜植物样品的制备技术

介绍几种生物样品的扫描电镜制样技术。这些技术操作简单，快速且实用。     

扫描电镜生物制样的改进

扫描电镜生物制样的改进李庚午，朱命炜，张根发（河南师范大学生物系，新乡４５３００２）利用ＳＥＭ观察生物材料，因生物材料不导电而必须在观察前进行一系列处理，在这些过程中以固定、脱水、干燥、喷镀几个环节尤为重要，加之生物材料种类繁杂，其制样方法各环节的种...     

湿木材的环境扫描电镜观察

本文用环境扫描电镜(environmental scanning electron microscopy，ESEM)对饱水杉木切片进行了观察。结果表明：1)ESEM可用于观察未经任何处理的湿木材细胞；2)通过在不同条件下对样品的观察，得知样品温度5℃、样品室气压732Pa(样品周围的相对湿度85％)是比较合适的环境条件，拍摄得到的照片最清晰；3)环境方式下对样品的观察和对图像的记录等操作应尽快完成，以减少样品内水分的蒸发而使样品的变形降至最低。     

Target materials suitable for projection X-ray microscope observation of biological samples

Trials for improving the contrast of projection X-ray images by finding better target materials than Ti (lambda K alpha: 2.75 A), which has been found to be suitable for many kinds of specimens, were carried out, considering the factors of melting point, thermal conductivity, mechanical strength, chemical stability, absorption of the X-ray, etc. Au, Ta, and Ge were found to be suitable, giving 5-10 A X-rays when low electron beam energies around 10 kV were used. In order to take advantage of the long wavelength X-rays of these targets, we tried to minimize the attenuation of the imaging X-rays in the air or to use a vacuum camera. Even in non-stained biological samples such as HeLa cells and lingual muscle section, their microstructures were visible with sufficient contrast.     

Nanomanipulation of biological samples using a compact atomic force microscope under scanning electron microscope observation

We introduce a compact nanomanipulator that can be operated inside the sample chamber of a scanning electron microscope (SEM) for biological sample manipulation. The design of the nanomanipulator is based on that of an atomic force microscope (AFM). A self-sensitive cantilever is used to realize the compact body and thus it is possible to put a pair of the standalone AFM units on the sample stage in the SEM chamber. Using this system, we accomplished nanodissection of biological samples as well as AFM imaging under SEM observation. We then fabricated the surface of a rat renal glomerulus by scan-scratching and succeeded in making a small hole on the wall of a blood capillary. As a result, it was possible to observe the internal structure of the capillary, which had been hidden beneath the surface wall. Furthermore, using two AFM units on the sample stage of the SEM, we successfully dissected the lens fiber cells taken from a rat eye in a multi-probe operation using the two cantilevers. This system is expected to become a very useful tool for micro- and nanometer-scale anatomy and engineering applications.     

De-noising techniques for terahertz responses of biological samples

Signal processing techniques may be used to improve the speed, resolution and noise robustness of pulsed terahertz (T-ray) imaging systems. Such systems have a wide range of applications and much recent interest has focussed on several promising biomedical fields. There are a number of significant challenges to be overcome before a commercial biomedical terahertz system can be realised. Recent research is focussed on the implementation of a high speed, compact and portable T-ray imaging system. This system will draw heavily on MOEMS technology. One of the major stages in the development of such a system is the design of efficient software algorithms to perform signal recognition and imaging operations in real time.

This paper considers a number of signal processing techniques suitable for de-noising and extracting information from the data obtained in a terahertz pulse imaging system. Two main de-noising techniques are considered. Wavelet de-noising and Wiener deconvolution algorithms are applied to the terahertz responses of biological samples including Spanish Serrano ham and an oak leaf.     

Electromagnetic wave scattering from some vegetation samples

For an incident plane wave, the field inside a thin scatterer (disk and needle) is estimated by the generalized Rayleigh-Gans (GRG) approximation. This leads to a scattering amplitude tensor equal to that obtained via the Rayleigh approximation (dipole term) with a modifying function. For a finite-length cylinder the inner field is estimated by the corresponding field for the same cylinder of infinite length. The effects of different approaches in estimating the field inside the scatterer on the backscattering cross section are illustrated numerically for a circular disk, a needle and a finite-length cylinder as a function of the wave number and the incidence angle. Finally, the modeling predictions are compared with measurements     

ESEM的特点及其X射线分析

环境扫描电子显微镜（ＥＳＥＭ）保留了传统扫描电子显微镜的全部优点，但取消了样品环境必须是高真空的限制，在气体压力高达６６００Ｐａ，温高达１５００℃，具有任何气体种类的多气环境里，ＥＳＥＭ都可提供高分辨率的二次电子成像。本文介绍了ＥＳＥＭ的特点、应用领域及Ｘ射线分析的有关问题。     

Experimental observation of FIB induced lateral damage on silicon samples

Scanning spreading resistance microscopy (SSRM) and scanning capacitance microscopy (SCM) were used to analyze focused ion beam (FIB) induced lateral damage around milled structures on silicon. For this purpose, circular shaped structures were realized, and the influence of the implanted Ga dose (ranging from 10¹⁵ to 10¹⁷ cm^?2) and of the patterned area dimension (diameters ranging from 1 to 4 μm) on the damage were examined. It is shown that the extension of the lateral damage around FIB milled structures is much larger than the area of the purposely irradiated regions (up to a factor of 5) and increases with both, Ga dose and pattern diameter. Besides, the unique capability of SCM and SSRM techniques for the detection of FIB induced damage is demonstrated. In particular, it is shown that their high sensitivity to low densities of defects allows detecting larger damaged areas compared to Atomic Force Microscopy (AFM) topography maps.