There are multiple definitions:

1. least square fitting(English)

   • OLSF
   • Statistics

2. long segment fixation(English)

   • refers to osteoporotic thoracolumbar compressive fractures
   • LSF-VP, VA, VP
   • Spine (or spinal cord), Surgery
   • http://pubmed.n…h.gov/24501892/

3. laser-stimulated fluorescence(English)

   • a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV
   • UV
   • Laser technique, Fluorescence
   • https://doi.org…al.pone.0125923