para-aminobenzoic acid对氨苯甲酸 polyclonal antibody多克隆抗体 pulsed adsorption bed脉冲吸附床 purple agar base紫琼脂(培养基) blood agar base血琼脂基质 premature atrial beat(s)房性过早搏动,房性期前收缩 para-amino benzyl对氨基苄基