Life Sciences Commons^™

Detectors For Quantitative Electron Beam Voltage Measurements, A. R. Dinnis

Scanning Microscopy

Qualitative voltage contrast is produced without difficulty in any SEM. Complete separation of the voltage contrast from other sources of contrast is not a straightforward matter because of the nonlinear relations between the phenomena causing contrast and the video signal.

Quantitative measurements depend on the availability of electron energy analysers which can detect accurately the shift in secondary electron energies due to potentials appearing on integrated circuit tracks, without being affected by transverse fields due to potentials on other conductors or insulators. The principles underlying existing detectors are explained, their effectiveness assessed, and a new form of electron detector is …

The Influence Of Analyser Geometry Effects In Scanning Electron Microscope Voltage Contrast Measurements, Daniel S.H. Chan, Teck Seng Low, Wai Kin Chim, Jacob C. H. Phang

Scanning Microscopy

A computer simulation model used to study specimen dependent and analyser geometry dependent effects is described in this paper. With this model, the influence of the specimen dependent effect on quantitative voltage contrast measurements can be isolated from the analyser geometry dependent effect. Linearization error voltages in quantitative voltage contrast measurements arising from the individual influences of the specimen dependent and analyser geometry dependent effects are presented. The results show that the error component due to very narrow analysers dominate the total linearization error. The same situation arises when the voltage measurement point on the specimen is very near to …

Bovine Aorta Endothelial Cell Incubation With Interleukin 2: Morphological Changes Correlate With Enhanced Vascular Permeability, Corazon D. Bucana, Joann Trial, Audrey C. Papp, Kenneth K. Wu

Scanning Microscopy

Interleukin 2 induced alterations in the morphology of bovine aortic endothelial cells in vitro. The changes observed in confluent cultures of bovine aortic endothelial cells included retraction and elongation of eel ls leading to enlarged gaps between cells quantified by image analysis. Purified IL-2 (1 U/ml medium) increased the gaps between endothelial cells 3-4-fold compared with control cultures. The effect was transient, since the cells reverted to their original morphology 6-12 hours after the removal of lL-2. Correlative scanning electron microscopy (SEM) studies using fresh bovine aorta showed a dose-dependent alteration of the endothelial surface by IL-2 characterized by rounding …

Changes In The Ultrastructure Of Emulsions As A Result Of Electron Microscopy Preparation Procedures, M. Liboff, H. D. Goff, Z. Haque, W. K. Jordan, J. E. Kinsella

Food Structure

Various methods of preparing emulsions for electron microscopy were examined with peanut oil/protein and ice cream mix emulsions. For transmission electron microscopy {TEM) , fresh peanut oil/bovine serum albumin emulsions were mixed with 2% agar , fixed in phosphate-buffered (pH 7 . 0) 4% glutaraldehyde solution and postfixed in phosphate-buffered (pH ? . 0) 1% osmium tetroxide alternatively , the glutaraldehyde- fixed samples were briefly rinsed in acetone prior to postfixation . Both preparations yielded satisfactory fat globule preservation. Similar emulsions were prepared on loops and suspended over vapors of 25% gJ nt.RrBl r'lehyr'le Rnc'l 1% oRmi urn tetroxide . …