Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic representation of the formation of filaments. (A) The first nucleus of an anisotropic phase and the thin sheets growing outwardly. (B) The narrow sheets (ribbons) writhing into helices. (C) Subsequent, tighter twisting of the ribbons into filaments, which coil eventually into tubules; wider sheets rolling up into filaments. (D) The final filaments.
