A Harvard Medical School scientist, Kseniia Petrova, 30, has been detained by US immigration officers after returning from Paris with undeclared frog embryos for research, facing possible deportation to Russia. Petrova, who was working on a groundbreaking cancer detection microscope, had her J-1 visa canceled after authorities found vials and messages indicating she planned to smuggle materials into the country. Seeking asylum due to political activism against the war in Ukraine, her immigration court hearing is set for May 7.