A million Americans who have had heart attacks or strokes caused by blood clots now take anti-clotting drugs regularly to cut down the danger of recurrences. But their blood takes so much longer to ...

Megakaryocytes, which are derived from hematopoietic stem cell precursors in bone marrow, form and release platelets; these circulate in the blood for 8 to 10 days before they are removed by hepatic ...