There are multiple definitions:

1. particle residence time(English)

   • CFD, MRI

2. pathogen reduction technology(English)

   • Pathology

3. phenol red thread [tear test](English)

   • CTT, SIT, STT
   • Ophthalmology
   • https://doi.org…24.2007.00521.x

4. pineal region tumor(English)

   • tumor arising from the pineal gland and the paraspinal structures
   • CNS, GCT, NET, PGC, PPT
   • Brain (dys)function, Oncology
   • https://doi.org…381-023-06081-1

5. positive reinforcement training(English)

   • a form of conditioning in which the subjects are given positive reinforcement (e.g., food treat or social interaction) following their performance of a desired behavior. It relies on the voluntary cooperation of animals, rather than on compelling them to comply through manual restraint or chemical restraint
   • Experimental animal, Behavior(al science)
   • http://pubmed.n…h.gov/29787205/