There are multiple definitions:

1. poly-L-lysine(English)

   • a synthetic, positively charged amino acid chain that enhances cell adhesion by altering surface charges on the culture substrate
   • LB1, PDGF-AA, O-2A, AS, ECM, FCS, GFAP, K-AS
   • Culture medium
   • https://doi.org…1606(91)90474-h
   • https://innopro…/poly-l-lysine/

2. phase-locked loop(English)

3. passive leg lifting(English)

   • E/A, E/SV, HF, LV, PCWP, RHC, RV, SV, TRG
   • Cardiology, Hemodynamics, Pulmonology
   • https://doi.org…1111/echo.15756