<title>Three-dimensional image reconstructions from a partially confocal scanning microscope</title>

Three-dimensional image formation in an interference confocal scanning microscope under ultra-short pulsed beam illumination is investigated in this study. The novelty of this new image system is that it keeps advantages in femtosecond interferometry but also provides a femtosecond-resolved three-dimensional image without necessarily using an ultrafast detector. For a 5-fs pulsed beam illumination, spatial resolution in the axial and transverse directions in this system is improved by approximately 45% and 15%, respectively, compared with that in the case of continuous wave illumination. However, strong chromatic aberration caused by an ultrashort pulsed beam can result in a degradation of spatial and temporal resolution, whereas weak chromatic aberration may lead to an improvement in transverse resolution.

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Three-dimensional coherent transfer function in a reflection-mode confocal scanning microscope

Optics Communications ◽

10.1016/0030-4018(91)90616-l ◽

1991 ◽

Vol 81 (5) ◽

pp. 281-284 ◽

Cited By ~ 39

Author(s):

C.J.R. Sheppard ◽

Min Gu ◽

X.Q. Mao

Keyword(s):

Transfer Function ◽

Three Dimensional ◽

Scanning Microscope ◽

Reflection Mode ◽

Confocal Scanning

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Image Reconstructions of Microtubules Decorated with Monomeric and Dimeric Kinesins: Comparison with X-Ray Structure and Implications for Motility

The Journal of Cell Biology ◽

10.1083/jcb.141.2.419 ◽

1998 ◽

Vol 141 (2) ◽

pp. 419-430 ◽

Cited By ~ 74

Author(s):

A. Hoenger ◽

S. Sack ◽

M. Thormählen ◽

A. Marx ◽

J. Müller ◽

...

Keyword(s):

Crystal Structure ◽

Image Reconstruction ◽

Three Dimensional ◽

Coiled Coil ◽

Cryoelectron Microscopy ◽

Short Neck ◽

X Ray ◽

Dimensional Image ◽

Tubulin Subunit ◽

Image Reconstructions

We have decorated microtubules with monomeric and dimeric kinesin constructs, studied their structure by cryoelectron microscopy and three-dimensional image reconstruction, and compared the results with the x-ray crystal structure of monomeric and dimeric kinesin. A monomeric kinesin construct (rK354, containing only a short neck helix insufficient for coiled-coil formation) decorates microtubules with a stoichiometry of one kinesin head per tubulin subunit (α–β-heterodimer). The orientation of the kinesin head (an anterograde motor) on the microtubule surface is similar to that of ncd (a retrograde motor). A longer kinesin construct (rK379) forms a dimer because of the longer neck helix forming a coiled-coil. Unexpectedly, this construct also decorates the microtubule with a stoichiometry of one head per tubulin subunit, and the orientation is similar to that of the monomeric construct. This means that the interaction with microtubules causes the two heads of a kinesin dimer to separate sufficiently so that they can bind to two different tubulin subunits. This result is in contrast to recent models and can be explained by assuming that the tubulin–kinesin interaction is antagonistic to the coiled-coil interaction within a kinesin dimer.

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