Anticoagulants/pharmacology; Antidotes/pharmacology; Aptamers, Nucleotide/pharmacology; Blood Coagulation/drug effects; Prothrombin/metabolism; Thrombin/metabolism; Animals; Anticoagulants/chemistry; Anticoagulants/metabolism; Antidotes/chemistry; Antidotes/metabolism; Aptamers, Nucleotide/chemistry; Aptamers, Nucleotide/metabolism; Base Sequence; Binding, Competitive; Catalytic Domain; Cattle; Dogs; Drug Stability; Enzyme Activation; Factor Va/metabolism; Half-Life; Humans; Mice; Molecular Sequence Data; Nucleic Acid Conformation; Partial Thromboplastin Time; Platelet Activation/drug effects; Protein Binding; Prothrombin Time; Rabbits; Rats; Ribonucleases/metabolism; SELEX Aptamer Technique; Sheep; Species Specificity; Structure-Activity Relationship; Swine; Thrombin Time