[{"from": "human", "value": "Provide a brief overview of this molecule. [N+1][=Branch1][C][=O][Branch1][C][O][O-1].[N+1][=Branch1][C][=O][Branch1][C][O][O-1].[O][=U][=O]"}, {"from": "gpt", "value": "The molecule is a chemical compound of uranium. It is used as a negative stain in electron microscopy and in nuclear reprocessing. Uranium is a chemical element that has the symbol U and atomic number 92. It is a normal part of rocks, soil, air, and water, and occurs in nature in the form of minerals. Nitrite is a toxic compound known to cause methemoglobinemia. (L1137,  L248, L249, L257)"}]