Period 4 element be dangerous in large enough quantities due to its radioactivity. Nickel (Ni) is an element in period 4, between cobalt and copper. Nickel is rare in the Earth's crust, mainly due to the fact that it reacts with oxygen in the air, with most of the nickel on Earth coming from nickel iron meteorites. However, nickel is incredibly common in the Earth's core; along with iron it is one of the two main components. Nickel is an important component of stainless steel, and in many superalloys. Copper (Cu) is an element in period 4, between nickel and zinc. Copper is
CU-2010 and CU-2020 CU-2010 and CU-2020 CU-2010 and CU-2020 are synthetic compounds that act as serine protease inhibitors. These were developed in 2010 to replace the use of aprotinin during and after cardiac surgery, including surgeries with cardiopulmonary bypass which cause blood loss and hemorrhagic complications. CU-2010 and CU-2020 were developed to avoid many issues associated with the use of aprotinin, including the risk of an allergic reaction and infection. Since the isolation of aprotinin is expensive, a drug with a simpler synthesis was desired. CU-2010 has a molecular weight of 700 Da and binds to the active site of serine proteases, like