Flat polygons

Remember In determining chirality in substituted cycloalkanes, always draw the rings as flat polygons. This is especially true for cyclohexane derivatives, where having two chair forms that interconvert can make analysis especially difficult. 

Dissociated brain cells from newborn rat cultured for 24 days on a plastic surface developed into a pure glial cell population (Fig. lA). In agreement with previous observations (43) the neuronal cells degenerated during the first 2 days and some oligodendrocytes survived for about a week. On the other hand, the flat polygonal shaped cells multiplied actively and formed a monolayer within 2 weeks. The cells contained in these astrocyte primary cultures were identified by their positive immunoreaction with anti-GFAP antiserum (38, 39). As shown in Fig. IB,... 

Capstan imagesetters, the third common technology, slowly advance the film or paper across a flat surface. A single laser beam is scaimed across the width of the medium by a rotating polygon or resonant mirror. 

In the polygonized nanotubes observed by Liu and Cowley]12,13], the edges of the polygon must have more sp character than the flat faees in between. These are defeet lines in the sp network. Nanotubes mechanically deformed appear to be rippled, indicat-... 

At the corneal surface, two to four layers of polygonal, extremely flat, and terminally differentiated superficial cells can be found. The cell diameters are 40-60 /xm with about 2-6 /xm thickness. The corneal surface is populated with microvilli and microplicae, resulting in surface area enlargement. These structures are associated with the tear film. Superficial corneal epithelial cells are... 

For rounded particles the operational sphericity, is well approximated (K2, P3) by ( 2 i) which is exact for ellipsoids. However, i/ p is not generally a good approximation to ij/. Aschenbrenner (A2) showed that a better approximation to ij/ is given by a working sphericity obtained from the flatness and elongation ratios by a result derived for a specific truncated polygonal form ... 

The polyhedron corresponding to the Neovius surface has the same arrangement of points as that for the infinite semi-regular polyhedral surface 6.43 discussed above, but the spaces between the points are differently filled with polygons so that each of the 48 points per cubic cell has the configuration of 8.4.8.6 and this leads to a surface of genus of 9. This surface has two kinds of flat points and is thus not regular (Mackay Terrones 1991). 12 tubes in the [110] directions connect cavities. 

Lichenoid eruptions are so called because of their resemblance to lichen planus, a papulosquamous disorder that characteristically presents as multiple, discrete, violaceous, flat-topped papules, often polygonal in shape and which are extremely pruritic. 

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