Simulated Dark-Field Electron Micrographs of Point Defects and Organometallics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114621 ◽

1975 ◽

Vol 33 ◽

pp. 200-201

Author(s):

William Krakow

Keyword(s):

Electron Micrographs ◽

Point Defects ◽

Structure Determination ◽

Atomic Structure ◽

Image Interpretation ◽

Dark Field ◽

Field Electron ◽

Dark Field Microscopy ◽

Dark Field Electron

Tilted beam dark-field microscopy has been applied to atomic structure determination in perfect crystals, several synthesized molecules with heavy atcm markers and in the study of displaced atoms in crystals. Interpretation of this information in terms of atom positions and atom correlations is not straightforward. Therefore, calculated dark-field images can be an invaluable aid in image interpretation.

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Utilizing Dark Field Electron Microscopy to Produce Lantern Slides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050597 ◽

1974 ◽

Vol 32 ◽

pp. 116-117

Author(s):

J. N. Meador ◽

C. N. Sun ◽

H. J. White

Keyword(s):

Electron Microscope ◽

Electron Micrographs ◽

Dark Field ◽

Limiting Factor ◽

Clinical Laboratories ◽

Field Electron ◽

Time Element ◽

Field Electron Microscopy ◽

Dark Field Electron ◽

Dark Field Micrographs

The electron microscope is being utilized more and more in clinical laboratories for pathologic diagnosis. One of the major problems in the utilization of the electron microscope for diagnostic purposes is the time element involved. Recent experimentation with rapid embedding has shown that this long phase of the process can be greatly shortened. In rush cases the making of projection slides can be eliminated by taking dark field electron micrographs which show up as a positive ready for use. The major limiting factor for use of dark field micrographs is resolution. However, for conference purposes electron micrographs are usually taken at 2.500X to 8.000X. At these low magnifications the resolution obtained is quite acceptable.

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Image processing of dark-field electron micrographs

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/9/2/007 ◽

1976 ◽

Vol 9 (2) ◽

pp. 175-181 ◽

Cited By ~ 5

Author(s):

W Krakow ◽

K B Welles ◽

B M Siegel

Keyword(s):

Image Processing ◽

Electron Micrographs ◽

Dark Field ◽

Field Electron ◽

Dark Field Electron

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Radial distributions of density within macromolecular complexes determined from dark-field electron micrographs.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.81.20.6363 ◽

1984 ◽

Vol 81 (20) ◽

pp. 6363-6367 ◽

Cited By ~ 39

Author(s):

A. C. Steven ◽

J. F. Hainfeld ◽

B. L. Trus ◽

P. M. Steinert ◽

J. S. Wall

Keyword(s):

Electron Micrographs ◽

Dark Field ◽

Macromolecular Complexes ◽

Field Electron ◽

Dark Field Electron

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Signal to noise enhancement in dark field electron micrographs of vasopressin: filtering of arrays of images in reciprocal space

Journal of Microscopy ◽

10.1111/j.1365-2818.1977.tb01139.x ◽

1977 ◽

Vol 109 (3) ◽

pp. 259-268 ◽

Cited By ~ 50

Author(s):

F. P. Ottensmeyer ◽

J. W. Andrew ◽

D. P. Bazett-Jones ◽

A. S. K. Chan ◽

J. Hewitt

Keyword(s):

Electron Micrographs ◽

Dark Field ◽

Reciprocal Space ◽

Signal To Noise ◽

Field Electron ◽

Dark Field Electron

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Three-dimensional reconstruction from dark-field electron micrographs of macromolecules at random unknown angles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100129929 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1058-1059 ◽

Cited By ~ 1

Author(s):

F.P. Ottensmeyer ◽

N.A. Farrow

Keyword(s):

Electron Microscopy ◽

Electron Micrographs ◽

3D Structure ◽

Dark Field ◽

Geometric Constraints ◽

Klenow Fragment ◽

Alignment Procedure ◽

Small Proteins ◽

Field Electron ◽

Dark Field Electron

Electron microscopy produces 2D images of 3D objects with resolutions generally from about 2-5 nm for stained or shadowed specimens, to as good as 0.3-0.5 nm for unstained specimens using bright field or dark field techniques. Many groups have worked on methods that attempt to recover the 3D information that is lost in the 2D representation. We have built on and extended previous techniques, and report here the development and application of a robust, unbiased quaternion-based alignment procedure to facilitate 3D reconstruction of molecules imaged at random unknown orientations. The approach is demonstrated using dark field electron micrographs of the Klenow fragment of DNA polymerase.Many procedures for 3D structure determination using electron microscopy have been reported. For fairly simple, small proteins it has been possible to derive a correct high resolution 3D structure by folding the known amino acid chain using dark field electron micrographs as geometric constraintse.g.. However, in general the reconstruction of a 3D density distribution requires knowledge of the relative orientation of different projection images of the object. To determine such orientations a variety of techniques have been employed, frequently adapted to the specimen of interest.

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