Interlocked segments

The remaining three antiparallel /3 structures form a miscellaneous category (see Fig. 84). Lactate dehydrogenase d2 and gene 5 protein each has several two-stranded antiparallel j8 ribbons, but they do not coalesce into any readily described overall pattern. The N-terminal domain of tomato bushy stunt virus protein has a unique /3 structure in which equivalent pieces of chain from three different subunits wrap around a 3-fold axis to form what has been called a /3 annulus (Harrison et ah, 1978). Each of the three chains contributes a short strand segment to each of three three-stranded, interlocking /3 sheets. This domain provides one of the subunit contacts that hold the virus... 

The appearance in the spectrum of the membrane of peaks assigned to amino acids of the protein, only after the membrane has been placed in urea or trifluoroacetic acid, shows that the segmental motion of these amino acid groups is inhibited by high local viscosity when the membrane is present in normal D20. The spectroscopic evidence suggests that the polymethylene chains of the lipid and some of the amino acids of the protein may be mutually interlocked. However, both lipid-lipid and amino acid-amino acid interactions could also be occurring. 

Many modifications of the three types of contactors just discussed have been developed in an effort to reduce costs, reduce pressure drop, equalize vapor flow through each contactor, increase plate efficiencies, or, in general, improve the operating performance of the tower. An example of this for modification of bubble-cap towers is the old Uniflux tray originally developed by Socony-Vacuum, which consisted of a series of interlocking S-shaped sections which were assembled in the form of tunnel caps with slot outlets on one side only. Segmental downcomers, similar to the downcomers in conventional bubble-cap columns, were provided. The vapors issued from the Uniflux caps in... 

Gibson et al. reported that the copolymerization of poly(THF) and a diol-pseudorotaxane consisting of 4,4/-bipyridinium salt and bis-p-phenylene crown ether with diisocyanate afforded the corresponding polyurethane with the interlocked structure [48] (Scheme 6). Although this polyurethane has a pseudopolyrotaxane structure, the interlocked structure is stable because the interaction between 4,4/-bipyridinium salt and bis-p-phenylene crown ether is strong enough to keep the inclusion complex. In this elastic polyurethane, the rotaxane unit acted as a hard segment. 

All of the gels so far described have involved the interlocking of chain segments in microcrystallites or similar aggregates. Such junction zones account admirably for the typical properties of gels (see Section IV,1 p. 303), but the likelihood of other possibilities will next receive attention. 

Each uranium rod 140 comprises a plurality of rod segments 140a as best shown in Figs. 10 and 18 interlocked together to form in effect the continuous rod 140. On each end of each segment 140a is threaded as at... 

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