Thrombus formation on artificial surfaces: Correlative microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 840-841
Author(s):  
Quintin J. Lai ◽  
Stuart L. Cooper ◽  
Ralph M. Albrecht
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Polymer Surfaces ◽  
Flow Conditions ◽  
Transmission Electron ◽  
Adhesion Of Platelets ◽  
Microscopic Techniques

Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. Two major components of thrombi are blood platelets and the plasma protein, fibrinogen. Previous studies have examined interactions of platelets with polymer surfaces, fibrinogen with platelets, and platelets in suspension with spreading platelets attached to surfaces. Correlative microscopic techniques permit light microscopic observations of labeled living platelets, under static or flow conditions, followed by the observation of identical platelets by electron microscopy. Videoenhanced, differential interference contrast (DIC) light microscopy permits high-resolution, real-time imaging of live platelets and their interactions with surfaces. Interference reflection microscopy (IRM) provides information on the focal adhesion of platelets on surfaces. High voltage, transmission electron microscopy (HVEM) allows observation of platelet cytoskeletal structure of whole mount preparations. Low-voltage, high resolution, scanning electron microscopy allows observation of fine surface detail of platelets. Colloidal gold-labeled fibrinogen, used to identify the Gp Ilb/IIIa membrane receptor for fibrinogen, can be detected in all the above microscopies.

Current and future aberration correctors for the improvement of resolution in electron microscopy

2009 ◽  
Vol 367 (1903) ◽  
pp. 3665-3682 ◽  
Author(s):  
M. Haider ◽  
P. Hartel ◽  
H. Müller ◽  
S. Uhlemann ◽  
J. Zach
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Voltage Electron ◽  
System A ◽  
Transmission Electron ◽  
Correction System

The achievable resolution of a modern transmission electron microscope (TEM) is mainly limited by the inherent aberrations of the objective lens. Hence, one major goal over the past decade has been the development of aberration correctors to compensate the spherical aberration. Such a correction system is now available and it is possible to improve the resolution with this corrector. When high resolution in a TEM is required, one important parameter, the field of view, also has to be considered. In addition, especially for the large cameras now available, the compensation of off-axial aberrations is also an important task. A correction system to compensate the spherical aberration and the off-axial coma is under development. The next step to follow towards ultra-high resolution will be a correction system to compensate the chromatic aberration. With such a correction system, a new area will be opened for applications for which the chromatic aberration defines the achievable resolution, even if the spherical aberration is corrected. This is the case, for example, for low-voltage electron microscopy (EM) for the investigation of beam-sensitive materials, for dynamic EM or for in-situ EM.

Correlative atomic-force microscopy and high-resolution scanning electron microscopy of proteins attached to platelet surfaces

1993 ◽  
Vol 51 ◽  
pp. 230-231
Author(s):  
S.R. Simmons ◽  
S.J. Eppell ◽  
R.E. Marchant ◽  
R.M. Albrecht
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Atomic Scale ◽  
Biological Macromolecules ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Electron

The atomic force microscope (AFM) has provided images at submolecular or atomic scale resolution of biological macromolecules attached to surfaces such as mica, graphite, or synthetic phospholipid membranes. Because the AFM can be operated with the sample in air, vacuum, or immersed in a liquid such as a biological buffer, it has the potential for high resolution imaging of the structure and organization of macromolecules on surfaces of cells in the hydrated or even living state. Realization of this potential would allow observation of molecular processes at the cell surface without the necessity for preparation of the sample for electron microscopy. To date, however, the AFM has yielded images of cell surfaces only at relatively low magnifications, and has not provided the atomic resolution achieved on hard, crystalline surfaces.Previously we have utilized correlative video-enhanced light microscopy, high voltage transmission electron microscopy, and low voltage, high resolution scanning electron microscopy (HRSEM)

scholarly journals High Resolution 20kV Transmission Electron Microscopy of Nanosystems – First Results Towards Sub Ångstrøm Low Voltage EM (SALVE – Microscopy)

2010 ◽  
Vol 16 (S2) ◽  
pp. 1702-1703 ◽  
Author(s):  
U Kaiser ◽  
J Meyer ◽  
J Biskupek ◽  
J Leschner ◽  
AN Khlobystov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Transmission Electron ◽  
First Results

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Processing of human melanoma cells for correlative TEM, LVSEM, and LM

1991 ◽  
Vol 49 ◽  
pp. 106-107
Author(s):  
Marek Malecki ◽  
J. Victor Small ◽  
James Pawley
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Fluorescent Microscopy ◽  
Blood Stream ◽  
Surface Topology ◽  
Integrin Receptors ◽  
Transmission Electron ◽  
Develop Technology ◽  
Voltage Scanning ◽  
Mechanisms Of Adhesion

The relative roles of adhesion and locomotion in malignancy have yet to be clearly established. In a tumor, subpopulations of cells may be recognized according to their capacity to invade neighbouring tissue,or to enter the blood stream and metastasize. The mechanisms of adhesion and locomotion are themselves tightly linked to the cytoskeletal apparatus and cell surface topology, including expression of integrin receptors. In our studies on melanomas with Fluorescent Microscopy (FM) and Cell Sorter(FACS), we noticed that cells in cultures derived from metastases had more numerous actin bundles, then cells from primary foci. Following this track, we attempted to develop technology allowing to compare ultrastructure of these cells using correlative Transmission Electron Microscopy(TEM) and Low Voltage Scanning Electron Microscopy(LVSEM).

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

High Resolution Transmission Electron Microscopy of an automobile catalytic converter

1990 ◽  
Vol 48 (4) ◽  
pp. 242-243
Author(s):  
Jan-Olle Malm ◽  
Jan-Olov Bovin
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Catalytic Converter ◽  
Active Material ◽  
Image Intensifier ◽  
High Resolution Electron Microscopy ◽  
Detailed Knowledge ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Atomic Surface

Understanding of catalytic processes requires detailed knowledge of the catalyst. As heterogeneous catalysis is a surface phenomena the understanding of the atomic surface structure of both the active material and the support material is of utmost importance. This work is a high resolution electron microscopy (HREM) study of different phases found in a used automobile catalytic converter.The high resolution micrographs were obtained with a JEM-4000EX working with a structural resolution better than 0.17 nm and equipped with a Gatan 622 TV-camera with an image intensifier. Some work (e.g. EDS-analysis and diffraction) was done with a JEM-2000FX equipped with a Link AN10000 EDX spectrometer. The catalytic converter in this study has been used under normal driving conditions for several years and has also been poisoned by using leaded fuel. To prepare the sample, parts of the monolith were crushed, dispersed in methanol and a drop of the dispersion was placed on the holey carbon grid.

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