Abstract: A shell-based material, also referred to as a shellular or a shell-based mechanical metamaterial, is comprised of a plurality of unit cells that are each made of a curved shell, and contain at least one perforation on their snapping motif. The shell-based material has a predetermined number of structural stable states based on the snapping motif and on the at least one perforation. The predetermined number of structural stable states including a first structural stable state, for example an unloaded initial state, and a second structural stable state being different from the first structural stable state.

Abstract: Copolymer-1 is a mixture of synthetic polypeptides composed of alanine, glutamic acid, lysine, and tyrosine. The invention relates to an improved process for the preparation of copolymer-1 characterized by the deblocking of the protected copolymer-1 that is carried out in one reaction. The process of the present invention has the advantage of high yield and ease of production. Copolymer-1 is a useful drug in treating multiple sclerosis.