The sudden shutdown of millions of dollars in federal funding to Columbia University this month is already disrupting medical and scientific research at the school as it confronts a Friday deadline to bow to government demands for sweeping changes in how it deals with dissent on campus.

Dozens of medical and scientific studies are ending or at risk of ending, leaving researchers scrambling to find alternative funding.

The US government has begun slashing US$400 million in research grants at Columbia University over pro-Palestinian campus protests.