There are multiple definitions:

1. acute pulmonary embolism(English)

   • Pulmonology

2. apurinic–apyrimidinic endonuclease(English)

   • plays a central role in repair of DNA damage due to reactive oxygen species because its DNA 3′-phosphoesterase activity removes 3′ blocking groups in DNA that are generated by DNA glycosylase/AP-lyases during removal of oxidized bases and by direct ROS reaction with DNA
   • DNA, ROS, UV, APE-1
   • Genetics
   • https://doi.org…/pnas.95.9.5061

3. atom percent excess(English)

   • COSIAM, ESI, FSR, HCA, LH, MPB, OVX, PCOS
   • Menstruation, Exercise & Training, Myocyte / muscle, Metabolism, Hormone
   • https://doi.org/10.1113/JP287342