| RI | radiation intensity; radioactive isotope; radioimmunology; recession index; recombinant inbred [stra... |
|---|---|
| RR | radiation reaction; radiation response; rate ratio; rational recovery [group]; recovery room; relati... |
| RRR | regular rhythm and rate; renin release rate (or ratio) |
| SERT | sustained ethanol release tube |
| SIR | single isomorphous replacement; specific immune release; standardized incidence ratio; syndrome of i... |