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:

Therapeutic potential of neuregulin-1 in cardiovascular disease. Neuregulin-1 (NRG-1)/ErbB signaling has an indispensable role in cardiac development and in the maintenance of the structural and functional integrity of the human adult heart in health and disease. Several animal studies have now demonstrated the therapeutic effects of NRG-1 during acute cardiac injury and during chronic heart failure, with improvements in cardiac performance and animal survival. Phase I and II clinical trials for chronic heart failure in humans are now in progress.
{"Chemical": []}