Researchers at the University of California, San Francisco, have been at the forefront of an emerging medical field that seeks to identify and help treat problems caused by stress. Now, these scientists hope to market their findings to physicians in the form of a test that can act as a personal report card on patients' health. "The science is there, and the time is right to bring it to the public," said Elizabeth Blackburn, one of the UCSF researchers who co-founded the business, Telome Health Inc. "We see a big market opportunity for this." Telome Health, which has 10 employees, is launching its website today to mark a more public phase of its business, following a flurry of studies in recent years that piggybacked on research by Blackburn and two of her colleagues, Jue Lin and Elissa Epel. Still, it might not be easy to persuade doctors and the public that they should pay about $200 to have their DNA examined as part of a regular check-up.