| NMF | N-methylformamide; National Medical Fellowship; National Migraine Foundation; nonmigrating fraction |
|---|---|
| NRF | Neurosciences Research Foundation; normal renal function |
| NSF | National Science Foundation; nodular subepidermal fibrosis |
| OIF | observed intrinsic frequency; oil immersion field; Osteogenesis Imperfecta Foundation |
| OREF | Orthopedic Research and Education Foundation |