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.