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:

Drug metabolizing enzymes in the perinatal and neonatal period: differences in the expression and activity. Physiological changes occurring perinatally and in the first month of life can affect the answer to a pharmacological treatment and the individual response to a drug in terms of efficacy and toxicity is highly variable in the neonatal population. Among potential causes for such variability, differences in drug metabolism may have a great impact. This article aims to review qualitative and quantitative differences in drug metabolizing enzymes in neonates, since both phase I and phase II metabolic pathways are immature at birth and subject to maturational changes in the first period of extrauterine life. Moreover, clinical implications will be discussed.
{"Chemical": []}