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:

Time-of-flight magnetic flow cytometry in whole blood with integrated sample preparation. Rapid and specific rare cell detection for point-of-care testing requires an integration of the sample preparation for flow cytometry. To achieve such a challenging goal we have developed a magnetic flow cytometry technique which applies magnetophoresis to perform cell enrichment, focusing, and background elimination in a single step. Time-of-flight measurements are performed with integrated magnetic sensors to detect specifically cancer cells and cell diameters in whole blood.
{"Chemical": []}