A Prcliminary Pharmacological Study on Differently Processed Leech Effects of Ginkgo biloba extract on anticoagulation and blood drug level of warfarin in healthy wolunteers Ultrasonic-assisted Extraction of Total Flavonoids from Peony Tree Seed Coat and Its Anticoagulation Activity Research progress on chemical constituents in plants of Melilotus Linn. and their pharmacological activities Study of a glycoprotein from Gastrodia elata: its effects of anticoagulation and antithrombosis Anticoagulation and fibrinolysis activity of fucoidan