18 citations,
January 1994 in “Skin pharmacology and physiology” Sunlight damages hair, causing cuticle loss, protein changes, and discoloration.
45 citations,
December 2006 in “Biopolymers” Permanent waving weakens hair by altering its protein structure.
12 citations,
January 2014 in “Cell structure and function” Different combinations of human hair keratins affect how hair fibers form.
4 citations,
July 2010 in “International Journal of Cosmetic Science” Curved human hair has different structures on its convex and concave sides.
January 2009 in “Nihon Keshouhin Gijutsushakaishi/Journal of S C C./Nihon Keshouhin Gijutsushakai kaishi” Curved human hair has different structures on each side, which might cause its shape and is similar to wool.