2568636 DBBC deproteinized bovine bone with collagen 2 2568635 DBBC dibutyl 1-butylamino-1-cyclohexanephosphonate 1 2568634 DBBC direct brain-to-brain communication 1 2568632 DBBC Dongxiang Black-Feathered Blue-Shelled Egg Chickens 1 2568633 DBBC dual-band bias circuit 1