| XD | x-ray diffraction |
|---|---|
| XRD | x-ray diffraction |
| 'Greek letter alpha' | angular acceleration; first [carbon atom next to the carbon atom bearing the active group in organic... |
| AO | abdominal aorta; achievement orientation; acid output; acridine orange; ankle orthosis; anodal openi... |
| DOA | date of admission; dead on arrival; Department of Agriculture; depth of anesthesia; differential opt... |