Single-molecule methods electron microscopy

J. W. Linnett. There were 11 papers with theoretical inputs but with more emphasis given to new developments in experimental methods including structural (LEED and electron microscopy) and surface spectroscopies. LEED provided crucial evidence for the role of surface steps at platinum single crystals in the dissociation of various diatomic molecules, while electron microscopy revealed the role of dislocations as sites of high reactivity of... 

Mesoporous structures are commonly characterized with diffraction, electron microscopy methods [14], and gas sorption techniques. The ensemble diffusion behavior of small molecules has been examined with pulsed-field gradient NMR spectroscopy [15] and neutron scattering [16]. Here, we are interested in techniques which give a more direct access to the real structure of the mesoporous host and to the dynamics on a single-molecule basis, and thus reveal structural and dynamic features which are not obscured by ensemble or statistical averaging as in conventional techniques. 

A FIGURE 18-12 Model of low-density lipoprotein (LDL). This class and the other classes of lipoproteins have the same general structure an amphipathic shell, composed of a phospholipid monolayer (not bilayer), cholesterol, and protein, and a hydrophobic core, composed mostly of cholesteryl esters or triglycerides or both but with minor amounts of other neutral lipids (e.g., some vitamins). This model of LDL is based on electron microscopy and other low-resolution biophysical methods. LDL is unique in that it contains only a single molecule of one type of apolipoprotein (apoB), which appears to wrap around the outside of the particle as a band of protein. The other lipoproteins contain multiple apolipoprotein molecules, often of different types. [Adapted from M. Krieger, 1995, in E. Haber, ed., Molecular Cardiovascular Medicine, Scientific American Medicine, pp. 31-47]... 

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