To make the dressing,the researchers grind crab shells to a fine powder and mix it with chemicals to convert the base material,chitin,into chitosan.

• 为制做敷药绷带的基层，专家们把蟹壳研磨成粉末状，又加人一些化学制剂，将基层的聚乙酸氨基葡糖转换成聚氨基葡糖。