NM exposure caused infiltration of inflammatory cells (PMNs) in the dermis of SKH-1 hairless and C57BL/6 mice following 12–120 h of its exposure.

+, Few (less than 100); ++, moderate (100–1000); +++, high (more than 1000) inflammatory cells per skin section (at 400×); VC, vehicle control.+：少量（每400倍放大视野下的皮肤切片中炎症细胞数少于100个）；++：中等量（100~1000个）；+++：大量（多于1000个）；VC：溶剂对照（vehicle control）