Chemical element named mendelevium in honor of D.I. Mendeleev, the first to arrange the elements in a periodic manner. Most recently, the synthesis of element 118 (since named oganesson) was reported in October 2006, and the synthesis of element 117 (tennessine) was reported in April 2010. Ten materials familiar to various prehistoric cultures are now known to be chemical elements: Carbon, copper, gold, iron, lead, mercury, silver, sulfur, tin, and zinc. Three additional materials now accepted as elements, arsenic, antimony, and bismuth, were recognized as distinct substances prior to 1500 AD. Phosphorus, cobalt, and platinum were isolated before 1750. Most of the
SB-269970 SB-269970 SB-269970 is a drug and research chemical developed by GlaxoSmithKline used in scientific studies. It is believed to act as a selective 5-HT receptor antagonist (EC = 1.25 nM) (or possibly inverse agonist). A subsequent study in guinea pig at 10 uM showed that it also blocks the α-adrenergic receptor activity. The significant difference in test concentrations, however, confirms the selectivity of SB-269970 for the 5-HT receptor. SB-269970 is used to study the 5-HT receptors which are thought to be involved in the function of several areas of the brain such as the hippocampus and thalamus, and regulation of