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They say what doesn’t kill you makes you stronger. But sometimes what makes you stronger can kill you, at least when it comes to blood clotting. Because the stickiness that allow platelets to heal your wounds also raises your risk of heart attack.
传言杀而不死，则至更强。但有时候，至少血栓，是杀得死你的哦。因为血小板的粘性虽然可以治愈你的伤口，但同时也增加了心脏病的发病几率。
All mammals use platelets to help prevent blood loss after traumatic injury. But birds don’t have ‘em, nor do reptiles or fish. Instead, these critters have blood cells called thrombocytes, which are about twice the size of platelets. But is bigger necessarily better when it comes to clotting? Scientists took thrombocytes from parakeets and put them to the test. The work appears in the journal Blood. [Alec A. Schmaier et al., "Occlusive thrombi arise in mammals but not birds in response to arterial injury: evolutionary insight into human cardiovascular disease"]
所有哺乳动物在受到外伤时都靠血小板止血。但是鸟类没有血小板，爬行动物和鱼类也没有。然而，这些生物有一种叫做thrombocytes的血细胞,是血小板的2倍大。但是对于凝血来说，越大效果就一定更好吗？对此，科学家从长尾鹦鹉体内提取thrombocytes进行测试。此项研究发表于《血液》杂志。
They focused their attention on birds because our feathered friends have a cardiovascular system much like our own, in that blood exerts pressure on walls of blood vessels.
科学家以鸟类作为研究对象的原因是，我们的长羽毛的朋友与我们的血管系统有相似之处：血液对血管内壁的施压方式相同。
The results: parakeet thrombocytes don’t stick together like platelets do. They also don’t block blood flow in the birds’ arteries the same way that platelets do when they form clots in mice.
研究结果：长尾鹦鹉的thrombocytes不会像血小板那样粘在一起，它们也不会像老鼠体内的血小板那样在凝结时阻塞动脉内的血液流动。
Which means that mice may be more likely to survive a bloodletting-pecking. But birds are far less likely to suffer from the clot formation called economy class syndrome—despite being frequent fliers.
结论是，老鼠不惧放血，而鸟亦无视经济舱综合征——尽管它们总是飞来飞去。
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