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In 1844, Charles Goodyear obtained the first patent for a rubber condom.
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.