Scanning strategies

A notable improvement in the vector-scanning strategy that has been reported involves the imaging of two apertures simultaneously, which enables the size and shape of the beam to be varied, thereby minimizing the number of flashes of the electron beam required to expose the area to be patterned.  

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Hogenboom A.C., Niessen W.M.A., and Brinkman U.A., 1999a. Online solid-phase extraction-short-column liquid chromatography combined with various tandem mass spectrometric scanning strategies for the rapid study of transformation of pesticides in surface water. J Chromatogr A 841 33. 

The mRNA of eucaryotes does not possess specific initiation sequences. Rather, the AUG start codon is identified by scanning the eucaryotic mRNA the 408 subunit of the ribosome threads the 5 non-translated end of the mRNA and uses the first AUG codon encoimtered to initiate translation. Whether a AUG codon is used as an initiator depends, additionally, upon the sequence context. If the sequence environment is unfavorable for initiation, then the scanning is continued and initiation occurs at one of the next AUG. With the help of this leaky scanning" strategy it is possible to produce proteins with different N-termini from the same mRNA. 8ince there are often signal sequences foimd at the N-terminus, this mechanism may lead to alternative com-partmentalization of a protein. 

Pos ltlonal scan Strategy for identifying individual compounds of interest in a library. A collection of sublibrarics is prepared. 

With provision for projected high magnification, the beam-line area is relatively extensive and can accommodate a range of ancillary equipment. This attribute makes the laboratory microtomography facility a very versatile instrument. It can operate in a variety of modes and support scanning strategies that arc tailored to particular subject shapes, sizes, and material content. With large-area... 

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