John Kelly and Dr. Marcia Angell were advocates on opposing sides of a Massachusetts measure to legalize physician-assisted suicide. Jesse Costa/Jesse Costa/WBUR hide caption

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Dr. Jame Abraham used positron emission tomography, or PET, scans to understand differences in brain metabolism before and after chemotherapy. Dr. Jame Abraham hide caption

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The number of new drug shortages each year in the U.S., from 2001 through Dec. 21, 2012. University of Utah hide caption

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Brain scans using Amyvid dye to highlight beta-amyloid plaques in the brain. Clockwise from top left: a cognitively normal subject; an amyloid-positive patient with Alzheimer's disease; a patient with mild cognitive impairment who progressed to dementia during a study; and a patient with mild cognitive impairment. Slide courtesy of the journal Neurology hide caption

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Doctors use tissue slides like this one of the ovary's outer cortex to confirm a woman's ovarian reserve. It's also the the ovary tissue that's removed in an ovarian transplant. Courtesy of the Infertility Center of St. Louis hide caption

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Kristen Miller, a colonoscopy patient, sits with Dr. Stephen Hanauer at the University of Chicago Medical Center in Chicago in 2010. They're looking at an interactive computer program describing benefits and risks of the procedure. Brian Kersey/AP hide caption

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Chimpanzees check out a termite mound at the Chimp Haven sanctuary in Louisiana. Chimp Haven hide caption

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The Ayurvedic remedies above were included in a 2004 study by researchers at Harvard Medical School that found dangerous levels of heavy metals in 14 out of 70 products. CHITOSE SUZUKI/ASSOCIATED PRESS hide caption

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For centuries, Russians believed putting a brown frog in their milk would keep it fresh. Now scientists are finding chemicals in the frog's slimy goo that inhibit the growth of bacteria and fungi. Stefan Arendt/Corbis hide caption

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Does a little sugar water before shots really help ease a babies' pain? If only they could tell us. Dmitry Naumov/iStockphoto.com hide caption

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