{"aspect_id":"AS135","aspect_name":"mass-ratio","aspect_reference":null,"aspect_symbol":null,"name":"mass-ratio microgram per kilogram","scale_id":"SC1742","scale_name":null,"scale_symbol":null,"scale_type":"ratio","symbol":"None \u00b5g.kg-1","unit_id":"UN1655","unit_name":"microgram per kilogram","unit_reference":null,"unit_symbol":"\u00b5g.kg-1"}