Addendum to “Three-dimensional mass density mapping of cellular ultrastructure by ptychographic X-ray nanotomography” [J. Struct. Biol. 192 (2015) 461–469]

Addendum to “Three-dimensional mass density mapping of cellular ultrastructure by ptychographic X-ray nanotomography” [J. Struct. Biol. 192 (2015) 461–469]