| SFIS | structural family interaction scale |
|---|---|
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| N(H) | proton density |
| PIXE | particle-induced x-ray emission; proton-induced x-ray emission |
| PMF | platelet membrane fluidity; progressive massive fibrosis; proton motive force; pterygomaxillary foss... |
| proton donor | <chemistry> An acid, a susbstance that donates protons in an acid-base reduction reaction. (10 Jan 1998) |
|---|---|
| proton-motive force | Energy that is generated by the transfer of protons or electrons across an energy-transducing membrane and that can be used for chemical, osmotic, or mechanical work. Proton-motive force can be generated by a variety of phenomena including the operation of an electron transport chain, illumination of a purple membrane, and the hydrolysis of ATP by a proton atpase. (12 Dec 1998) |
| proton pump | Integral membrane proteins that transport protons across a membrane against a concentration gradient. This transport is driven by hydrolysis of ATP by hydrogen-transporting ATP synthase. (12 Dec 1998) |
| proton pump inhibitor | <pharmacology> A group of anti-ulcer medications which work by binding to H+/K+ ATPase, an enzyme which is found on the secretory surface of parietal cells. It thereby inhibits the final transport of hydrogen ions (via exchange with potasium) into the gastric lumen. Examples of proton pump inhibitors include omeprazole and lansoprazole. (27 Sep 1997) |