Localization of potential Ca2+ binding sites in lily pollen tubes and maize calyptra cells: Transmission electron microscopy, proton microprobe analysis and electron spectroscopic imaging

With imaging energy filters becoming commercially available in transmission electron microscopy many of the limitations of conventional TEM instruments can be overcome. Energy filtered images of diffraction patterns can now be recorded without scanning using efficient parallel (2-dimensional detection. We have evaluated a prototype of the Zeiss EM 912 Omega, the first commercially available electron microscope with integrated imaging Omega energy filter. Combining the capabilities of the imaging spectrometer with the principal operation modes of a TEM gives access to many new qualitative and quantitative techniques in electron microscopy. The basis for all of them is that the filter selecte electrons within a certain energy loss range ΔE1 <ΔE < ΔE2 and images their contribution to an image (electron spectroscopic imaging, ESI) or a diffraction pattern (electron spectroscopic diffraction, ESD) In many applications the filter is only used to remove the inelastically scattered electrons (elastic or zero loss filtering). Furthermore, the electron energy loss spectrum can be magnified and recorded with serial or parallel detection.

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Transmission electron microscopy of pyrometamorphic breakdown of phengite and chlorite

Mineralogical Magazine ◽

10.1180/minmag.1987.051.359.10 ◽

1987 ◽

Vol 51 (359) ◽

pp. 107-121 ◽

Cited By ~ 17

Author(s):

R. H. Worden ◽

P. E. Champness ◽

G. T. R. Droop

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Microprobe Analysis ◽

Chemical Interaction ◽

Reaction Products ◽

Orientation Relationships ◽

Fine Grained ◽

Transmission Electron ◽

Significant Chemical ◽

Diagram Analysis

AbstractPhengite and chlorite have undergone decomposition during pyrometamorphism caused by the intrusion of a dolerite feeder pipe into Dalradian greenschists in Argyllshire, Scotland. All reaction products are extremely fine grained. Transmission electron microscopy has revealed that phengite pseudomorphs consist of biotite, spinel, mullite, sanidine and phengite, and that chlorite pseudomorphs consist of combinations of chlorite, spinel, orthopyroxene, magnetite, cordierite and biotite. Although the reactions were short-lived and did not go to completion, microprobe analysis and phase diagram analysis have revealed that there has been significant chemical interaction between the phyllosilicates and the surrounding rock. Numerous orientation relationships exist between the original minerals and their reaction products; the close-packed planes in the precursor phyllosilicates were inherited by their reaction products.

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Suppression of myoblast fusion by concanavalin A: possible involvement of membrane fluidity

Journal of Cell Science ◽

10.1242/jcs.28.1.251 ◽

1977 ◽

Vol 28 (1) ◽

pp. 251-272

Author(s):

A. Sandra ◽

M.A. Leon ◽

R.J. Przybylski

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Membrane Fluidity ◽

Binding Sites ◽

Subsequent Treatment ◽

Myoblast Fusion ◽

Cross Linking ◽

Con A ◽

Fusion Inhibition ◽

Transmission Electron

Experimental evidence is presented which is consistent with the involvement of membrane fluidity during myoblast fusion. Treatment of pretrypsinized myoblasts with tetrameric Con A, but not with the dimeric succinyl derivate, inhibits fusion. Inhibition is reversed by treatment with alpha-methyl-D-mannoside or subsequent trypsinization. No inhibition is observed when the lectin is incubated with cells at 4 degrees C unless the incubation is followed by treatment with glycogen, a multivalent Con A cross-linking agent. This effect of glycogen is reversed by subsequent treatment with alpha-amylase. Direct observation of Con A-binding site topography by transmission electron microscopy of membrane replicas of cells labelled with Con A and haemocyanin reveals that inhibition of fusion correlates with a clustered distribution of Con A-binding sites, whereas normal fusion correlates with a dispersed distribution.

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A study of iron-bearing rutiles in the paragenesis TiO2-Al2O3-P2O5-SiO2

Mineralogical Magazine ◽

10.1180/minmag.1978.042.322.14 ◽

1978 ◽

Vol 42 (322) ◽

pp. 255-263 ◽

Cited By ~ 8

Author(s):

A. Putnis ◽

M. M. Wilson

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Microprobe Analysis ◽

Electron Microprobe Analysis ◽

Stable Equilibrium ◽

Transmission Electron ◽

Different Temperatures ◽

Temperature Transformation ◽

Kinetics Of ◽

Iron Bearing

SummaryHydrothermal ruffles from a suite of rocks at Mount Perry, Queensland, have been studied in thin section, by electron microprobe analysis, and by transmission electron microscopy. The iron-bearing rutiles, while originally singte-phase, are found to exsolve a sequence of iron-rich precipitates on experimental annealing, with hematite being formed as the stable equilibrium precipitate. Experiments at different temperatures and annealing times enable a time-temperature-transformation plot to be drawn for the exsolution process. The kinetics of this process are used to conclude that the rutiles formed below about 450 °C.

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