This week, Kat Arney has been through the archives and picked out her personal Naked highlights, including making experimental jelly, sneezing at computer screens, stabbing potatoes and Ben dancing (badly) in the studio. She looks back on advances in cancer therapy, developments in making people bionic and how new diseases emerge, as well as reliving the chance to meet Alan Titchmarsh, for a chat about the importance of ponds. Plus, we have a brand new bit of the Naked Scientists, where we're looking at Chemistry in its element.