You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Alexander böhm (1971-2012). On November 28, 2012 Alexander (Alex) Böhm, a bacterial geneticist, died at age 41, only a few months after taking up a position as an assistant professor at the LOEWE Center for Synthetic Microbiology in Marburg, Germany. Earlier in 2012 Alex had been diagnosed with an aggressive form of thyroid cancer that left him little time to live his scientific and personal dreams.
{"Chemical": []}