[{"from": "human", "value": "What can you tell me about this molecule? [C][C][O][C][=Branch1][C][=O][C@H1][Branch1][Ring1][C][S][N][C][C][N][C@@H1][Branch1][Ring1][C][S][C][=Branch1][C][=O][O][C][C]"}, {"from": "gpt", "value": "The molecule is a N,N'-1,2-ethylene-di-yl-bis-L-cysteinate diethyl ester. It is used in conjunction with technetium Tc99m as a tracer to measure cerebral blood flow with single-photon emission computed tomography (SPECT). The complex of bicisate and technetium Tc99m as a kit was developed by Lantheus Medcl and FDA-approved on November 23, 1994."}]