Abstract Double alkyl quaternary ammonium salts have been prep ared through bromoalkane, an intermediate material.
以溴代烷为原料制备了双烷基二甲基溴化铵系列产品。

According to their inf ection history and major complications，they were separated into groupes and comp ared with each other.
观察肝，胆，胰等回声改变及肝硬化组门静脉血流指标。