More than 500 U.S. federally funded scientists have been flagged over their financial ties with China and other foreign adversaries, the National Institutes of Health says. As of this month, the federal health agency has reached out to 90 institutions that receive government grants, regarding 200 researchers. It also has removed 100 from the “NIH ecosystem” through resignation, termination, premature retirements, or internal debarments, according to Michael Lauer, deputy director for extramural research at the NIH. The biggest challenge is simply “the workload of dealing with a very large number of cases,” he added. “Each of these requires a tremendous amount of work to figure out what exactly has been happening and to work carefully with the institution to figure out what’s been going on,” Lauer said at an April 22 Senate committee hearing that focused on foiling Chinese efforts to exploit U.S. biomedical research advances. One scenario that Lauer …