Discovery and development of direct Xa inhibitors Xa was identified as a promising target for the development of new anticoagulants in the early 1980s. In 1987 the first factor Xa inhibitor, the naturally occurring compound antistasin, was isolated from the salivary glands of the Mexican leech "Haementeria officinalis". Antistasin is a polypeptide and a potent Xa inhibitor. In 1990 another naturally occurring Xa inhibitor was isolated, tick anticoagulant peptide (TAP) from extracts of the tick "Ornithodoros moubata". TAP and antistasin were used to estimate factor Xa as a drug target. Blood coagulation is a complex process by which the blood forms clots. It is an essential part
Creatures 2 near the oceans. Scattered throughout the world are various seed launchers, which can be used to replenish stocks if any life-forms become extinct. Albia also has four seasons: Spring, Summer, Winter and Autumn, and boasts its very own climate, with weather such as snow mainly occurring during the colder months, and rain mostly during the Spring. The game also has an on-screen thermometer, allowing the player to monitor Albia's temperature at all times. Creatures 2's release was widely anticipated. It is likely that around 450,000 copies of the original Creatures had been sold by the time the game was released,