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Biomedical subjects

R Uyeda

Publications and source records attributed to R Uyeda.

4 recordsLinked to original sources
PubMed1977

The bright and shadow images of an atom in the transmission electron microscope.

Scherzer discussed in his paper of 1949 the phase contrast of an atom image which was given in the form i(psi-psi). The second order term psi psi, which gave the bright image of the atom, was neglected. Under the first Born approximation as adopted by him, the phase contrast disappears at the exact focus of the ideal electron microscope. Under the second Born approximation, the phase contrast does appear under the same condition. It can be interpreted as the shadow image because it compensates the bright image.

Microscopy, Electron↗
PubMed1975

Electron microscope images of mercury atoms bound to DNA filament.

Ultra-fine grids with holes of a few hundred angstroms in diameter were made from tropomyosin for specimen supporting media. DNA was mounted on the grid. Microscope images were obtained demonstrating one double-stranded DNA filament bridging a hole. Using mercurated DNA a few filamentous images were observed in a bridge, and series of faint fine sports were recognized along an edge of a hole. These spots were interpreted as the images of single mercury atoms bound to the filament. The control experiment was made on unstained DNA, some images of which showed only uniform intensity over the bridge, whereas others were disturbed to some extent by noise presumably due to extraneous molecules coating the filament.

Coliphages↗