Hair Today, Gone Tomorrow? Teasing out details of hair growth

摘要

From the strength-giving locks of the biblical Samson to the elaborate updo of a geisha and the neon, spiked styles of punk rockers, hair remains an important part of a person's self-image and one of the most obvious forms of self-expression. People may cut their hair, dye it, perm it, and style it. But unless they resort to wigs and hair transplants, they are stuck with the quantity of hair that nature gives them—and takes away. That fact of life becomes especially vexing when people lose their hair to chemotherapy, diseases that attack hair follicles, or simply aging. And there are few options for hirsute women, who have an overabundance of hair and may even grow beards.