Nonclassical Chiral Elasticity of the Gyroid Lattice.

The gyroid lattice is a metamaterial which allows chirality that is tunable by geometry. Gyroid lattices were made in chiral and nonchiral form by 3D printing. The chiral lattices exhibited nonclassical elastic effects including coupling between compressive stress and torsional deformation.

Presacral tumors: case report, review of the literature.

A case report involving a 42-year-old female is presented. The symptoms and objective physical findings manifest a diagnostic problem. The anatomical site of the tumor depends on the consideration of the numerous possible etiological factors, and one of which is the embryologic knowledge of the region involved.