Regular Substructures Research Articles

Regular grid-like substructures in the midgut epithelial basement membrane of some Coleoptera.

The midgut epithelial basement membranes in 13 species of Coleoptera belonging to 11 families have been examined ultrastructurally and are described in the present work. Regular grid-like substructures are present in 6 species. One of the basement membranes possessing a regular structure is roughly characterized histochemically on the light microscopic level; it contains tyrosine-rich protein and PAS-positive carbohydrate but apparently no acid mucosubstances.

Grain-Boundary Fine Structure in an Iron Alloy

Regular substructures were observed in grain boundaries of an annealed Fe-0.75% Mn alloy by transmission electron microscopy. A detailed analysis was made on one of the grain boundaries. The result indicates that the analyzed grain boundary may be considered as a coincidence site grain boundary.