Contents

17 July 1992
Vol 257, Issue 5068

About The Cover

Color-enhanced image of a familiar formula written with an atomic force microscope. The lines of the letters are about 10 nanometers wide and 5 nanometers deep. The patterns are machined into a soft molybdenum oxide layer that was grown on a molybdenum sulfide substrate. See page 375. New techniques and instruments, especially in biomedical research, are the focus of the Science Innovations '92 meeting (21 to 25 July in San Francisco) sponsored by AAAS and Science; see related news stories on page 344. [Photo: Charles M. Lieber]