Non-helical models of DNA structure the top of this article, or there could be an equal number of right-handed and left-handed twists, as in the Rodley structure below. The abbreviation "TN", to be used to refer to any DNA structure whose strands are topologically non-linked, has been proposed. The double-helix model of DNA structure was first published in the journal "Nature" by James D. Watson and Francis Crick in 1953 with further details in 1954.) Their work was based upon the crucial X-ray diffraction image of DNA - labeled as "Photo 51" - from Rosalind Franklin in 1952, followed by her more highly clarified DNA
Maurice Wilkins Raymond [Gosling] and I got a clear crystalline X-ray pattern I was very eager to continue that work ... Trying to understand 'what really happened' when a very admirable scientist [Randall] models himself on Napoleon is not easy ... [but the letter] was very damaging to her and to me". By November 1951, Wilkins had evidence that DNA in cells as well as purified DNA had a helical structure. Alex Stokes had solved the basic mathematics of helical diffraction theory and thought that Wilkins's X-ray diffraction data indicated a helical structure in DNA. Wilkins met with Watson and Crick and