An extract from raw, green coffee beans has been called a "miracle" weight-loss aid. But a study in mice casts doubt on the supplement's fat-burning effects — and even offers preliminary evidence that it could be harmful.

Since the 1970s, doctors around the world have reported cases in which young kids regrow fingertips if an accident leaves some of the fingernail. Now scientists have figured out how this lizard-like regeneration happens in mice and suspect the same mechanism works in young humans.

Gonorrhea cases resistant to one of the last effective drugs increased by nearly six times from 2004 to 2011 in Great Britain. Hard-to-treat gonorrhea is a growing trend worldwide, as the bacterium begins to thwart our last defenses.

A type of bird flu that appeared in China a few months ago has infected more than a hundred people. Some scientists are worried that this virus has the potential spread globally. But a look at the virus's genes suggests the pathogen doesn't have the typical features of pandemic.

Biologists said last week that they had overcome a major obstacle in stem-cell research by cloning human embryos. But several images in the published study were duplicated and labeled incorrectly, prompting questions about the authenticity of the results.

A handful of polio infections in Kenya and Somalia could set back efforts to wipe out the virus worldwide, health workers warned Wednesday. The last time there was polio in this region, the virus spread throughout the Horn of Africa into the Middle East and eventually into Indonesia.

Architects have come up with spectacular concepts for vertical farms that would grow crops in city skyscrapers. But many horticulturists think the future of vertical farming isn't in skyscrapers, but rather in large, indoor warehouses lit up magenta by superefficient LEDs.

Engineers have figured out a way to get crystals to form rose and tulip sculptures, each smaller than a strand of hair. The gardens sprout up on a penny dipped in a salt solution. The technique is similar to 3-D printing and could one day be used to make any complex shape.

The world's top health problems are more common in men than women. But recent global funding has been skewed toward women's issues. Some health economists say more effort should go toward stopping men's risky behaviors, like smoking and drinking.

Scientists used a Dutch woman's dirty stocking to learn that mosquitoes infected with malaria find humans hard to resist. Like a fungus that turns ants into zombies, the parasite seems to change the behavior of the mosquitoes for its own benefit.

After decades of trying, scientists say they've finally figured out how to make personalized embryonic stem cells. One day, these designer cells may help treat an array of diseases. A jolt of caffeine and and a little electric shock helped to do the trick.

The achievement is a long-sought step toward harnessing the potential power of such cells to treat diseases. But the discovery raises ethical concerns because it brings researchers closer to cloning humans.

Infecting mosquitoes with a specific type of bacteria makes the insects resistant to malaria. Now scientists have figured out how to get the mosquitoes to pass the infections on to their offspring. If it can done reliably, it might help interrupt transmission of malaria to humans.

The Microsoft founder and philanthropist is putting his money and time where his passion is: eradicating polio. Gates talks with NPR's Robert Siegel about why it makes sense to spend an estimated $5.5 billion to wipe out the disease once and for all.

With the new H7N9 virus spreading through China and H5N1 popping up every now and then in Southeast Asia, it's tough to keep track of all the flu viruses. Here's a quick guide to what those H's and N's mean, and why viruses with these letters cause the most concern.

A new virus that causes severe pneumonia and sometimes kidney failure has infected more people. Since the virus first appeared in March 2012, it has infected 24 people, including 17 deaths.

As urban chicken farms grow in popularity, many people are bringing the birds into their homes. They need the right equipment to keep them clean. So several businesses have popped up online, offering everything from custom-sized diapers and leash-ready saddles to chicken caviar.

Scientists have deployed hundreds of tiny, experimental robots to help with biopsies. They're as small as a speck of dust. They look like tiny ninja throwing stars. And researchers use magnets to retrieve them.

Dog owners have similar germs growing on their skin: a signature blend of bacteria from canines' tongues and paws. Scientists couldn't find an analogous signature for cat owners. Perhaps cats are just being selfish.

A new strain of bird flu has sickened 82 people and killed 18 in China. But many people who have caught the H7N9 flu say they hadn't been near poultry or other birds. So what's fueling the outbreak of the virus?