In HIT, the immune system forms antibodies against heparin when it is bound to a protein called platelet factor 4 (PF4). These antibodies are usually of the IgG class and their development usually takes about five days.
The first elevator shaft preceded the first elevator by four years. Construction for Peter Cooper's Cooper Union Foundation building in New York began in 1853. An elevator shaft was included in the design, because Cooper was confident that a safe passenger elevator would soon be invented.
The main service elevator, positioned in the central core of Burj Khalifa, has the worldâs highest elevator rise at 504 metres â more than the height of Taipei 101 in Taiwan (448 metres). It travels at nine metres per second and also has the worldâs longest travelling distance for an elevator.