Swedish doctors have for the first time successfully used artificial blood to treat patients with a method they hope will eventually help revolutionise health care. The artificial blood is made from real blood that has been donated but which normally only has a shelf life of 42 days. Now, instead of throwing that blood away after 42 days, doctors are able to use the red blood cells to produce a powder that can be stored for several years. The powder can then be mixed into liquid form when needed, for example at the scene of an accident, and used immediately...