President-elect Donald Trump's pick of Robert F. Kennedy Jr. to lead the Department of Health and Human Services has brought back a debate about fluoride in drinking water that many thought was settled decades ago. Meg Oliver takes a look at how a lack of fluoride can affect dental health.
Engineers from Northwestern University revealed what they called “the world’s smallest pacemaker” on April 2, with the tiny device measuring smaller than a grain of rice.The university said the pacema...