A stent is a small mesh tube that's used to treat narrowed or weakened arteries in the body. Arteries are blood vessels that carry blood away from your heart to other parts of your body.

You may have a stent placed in an artery as part of a procedure called angioplasty. Angioplasty restores blood flow through narrowed or blocked arteries. Stents help prevent the arteries from becoming narrowed or blocked again in the months or years after angioplasty.

Mercury's surface looks similar to our Moon's. Each is heavily cratered and made of rock. Mercury's diameter is about 4800 km, while the Moon's is slightly less at about 3500 km (compared with about 12,700 km for the Earth). But Mercury is unique in many ways. Mercury is the closest planet to the Sun, orbiting at about 1/3 the radius of the Earth's orbit. As Mercury slowly rotates, its surface temperature varies from an unbearably cold -180 degrees Celsius to an unbearably hot 400 degrees Celsius. The place nearest the Sun in Mercury's orbit changes slightly each orbit - a fact used by Albert Einstein to help verify the correctness of his then newly discovered theory of gravity: General Relativity. The above picture was taken by the only sp ...

Patients with urinary tract infections can drink cranberry juice to make their urine more acidic.

Bacteria that cause a urinary tract infection multiply rapidly in alkaline urine, but not in acidic urine. Some types of kidney stones form in alkaline urine, but not in acidic urine.  

Sloths have a commensal relationship with several insects. Their thick fur readily traps bacteria and algae, which makes a good home for many beetles. The beetles are able to lay their eggs in a place that is rich in nutrients upon hatching, and the sloths don’t care either way. One sloth was reported to have over 900 beetles living in its fur!

Take a good look at that tiny piece of art. It is the smallest bone in the body is called the stirrup (or stapes) bone. It is one of the three bones that make up the middle ear; measuring about 2-3 millimetres. It has a U-shape and is the inmost bone that collects sound vibrations and then passes them along to the cochlea for interpretation by the brain. ...

This is Washoe, the first non-human to use sign language. When her caretaker Kat suffered a miscarriage, and Washoe was told that her baby had died, she signed "CRY", drawing a path down her cheek with her finger to mimic a tear. Chimpanzees don't shed tears, and Kat said this one sign told her more about Washoe's mental capabilities than all of her longer, grammatically perfect sentences.

A new vaccine has successfully killed the simian immunodeficiency virus (SIV) that causes AIDS in monkeys. It's hoped that with further research, an HIV-form of the vaccine can soon be tested in humans.