In situ azimuthal rotation device for linear dichroism measurements in scanning transmission x-ray microscopy.
Rev Sci Instrum
; 78(3): 033703, 2007 Mar.
Article
em En
| MEDLINE
| ID: mdl-17411187
ABSTRACT
A novel miniature rotation device used in conjunction with a scanning transmission x-ray microscope is described. It provides convenient in situ sample rotation to enable measurements of linear dichroism at high spatial resolution. The design, fabrication, and mechanical characterization are presented. This device has been used to generate quantitative maps of the spatial distribution of the orientation of proteins in several different spider and silkworm silks. Specifically, quantitative maps of the dichroic signal at the C 1s-->pi* (amide) transition in longitudinal sections of the silk fibers give information about the spatial orientation, degree of alignment, and spatial distribution of protein peptide bonds. A new approach for analyzing the dichroic signal to extract orientation distributions, in addition to magnitudes of aligned components, is presented and illustrated with results from Nephila clavipes dragline spider silk measured using the in situ rotation device.
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Base de dados:
MEDLINE
Assunto principal:
Microscopia Eletrônica de Transmissão e Varredura
Limite:
Animals
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article