| PSU | photosynthetic unit; primary sampling unit |
|---|---|
| PU | palindromic unit; passed urine; pepsin unit; peptic ulcer; pregnancy urine; 6-propyluracil; prostati... |
| RTU | real-time ultrasonography; relative time unit; renal transplantation unit |
| SCU | self-care unit; special care unit |
| SDU | standard deviation unit; step-down unit |