- Nicki Minaj Curious George 歌詞
- Nicki Minaj
- Yael:I just read about an exciting technique.Researchers found a way to convert types A and B blood into type O blood--the type that can be transfused into any patient.This advance could help avoid blood shortages in the future.
Don:Wow,that is exciting.But what makes type O blood so special?
Y:Blood types result from different carbohydrates,called antigens,on the surface of human blood cells.Your blood 'type'denotes the kinds of antigens you have on the surface of your cells.People with type A blood have A antigens;those with type B have B antigens.If you have both kinds of antigens,youre type AB;if you have neither one,youre type O.
Your immune system recognizes the antigens on your blood as 'self',but attack cells with 'foreign'antigens.So if you ever need a blood transfusion,its important that you only receive blood compatible with your own type.
D:I see.So if a type A person receives type B or AB blood,her immune system will see the B-antigens as foreign,and attack the donor blood cells?
Y:Exactly.But type O is called the 'universal donor'since it doesnt have any antigens that would set off the bodys defense system.
A team of Danish scientists has identified enzymes that remove the A and B antigens from blood cells.The enzymes,which were extracted from a bacteria and a fungus,essentiallychange any donated blood into type O.
Clinical trials are underway to test whether the treated blood is safe and effective.If so,the technology could help save lives,since type O blood is such a precious commodity
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