Hunting world-class talent for a new multimillion-dollar medical research center, Johns Hopkins University officials thought last spring that they had found the ideal candidate in a Yale molecular biologist named Heng Zhu. A rising star in the new field of proteomics, Zhu was being courted by laboratories in Canada and Germany. So Hopkins wasted no time. They whisked the 35-year-old Chinese scientist to Baltimore to meet the faculty, enlisted a real estate agent to sell him on the city, then handed over an offer described as “very generous.” Zhu was impressed. But then the university ran into a problem nobody counted on: the great wall of the post-Sept. 11 U.S. bureaucracy. Full Story