3-D imaging of molecules has always required multiple viewpoint to determine the proper 3-D structure, says the Physics arXiv blog's KFC. In 2009, however, Jianwei Miao and his colleagues at the University of California, Los Angeles, developed a technique called ankylography that could produce a 3-D structure from a single image. "Their thinking was that it ought to be possible to capture the complete 3-D structure from the diffraction pattern incident on a sphere. Instead of taking many images, an iterative algorithm could then distil the 3-D structure," KFC says. The work was criticized by other researchers who said the technique couldn't be scaled to larger objects, and that it only worked for things that were so thin they were essentially 2-D anyway. Miao and his colleagues were silent for a while, bbut now, KFC says, they've finally responded. They contend that their critics have made some unrealistic assumptions, and that while ankylography needs some modification it could eventually be used on a wider basis. "The advantage of being able to image 3-D objects with a single shot is obviously huge," KFC says. "It ought to allow, for example, 3-D movies of molecules as they move or change shape. That's tricky with other techniques when several shots are required to determine the structure at any instant."
From 2-D to 3-D
Dec 24, 2011