Bark (botany) rope, used for example in the rigging of Viking age longships. Among the commercial products made from bark are cork, cinnamon, quinine (from the bark of Cinchona) and aspirin (from the bark of willow trees). The bark of some trees notably oak ("Quercus robur") is a source of tannic acid, which is used in tanning. Bark chips generated as a by-product of lumber production are often used in bark mulch in western North America. Bark is important to the horticultural industry since in shredded form it is used for plants that do not thrive in ordinary soil, such as epiphytes.
Analgesic nephropathy of paracetamol into "N"-acetyl-"p"-benzoquinoneimine (NAPQI). NAPQI depletes glutathione via non-enzymatic conjugation with glutathione, a naturally occurring antioxidant. With depletion of glutathione, cells of the kidney become particularly sensitive to oxidative damage. Diagnosis is traditionally based on the clinical findings above in combination with excessive analgesic use. It is estimated that between 2 and 3 kg each of phenacetin or aspirin must be consumed before evidence of analgesic nephropathy becomes clinically apparent. Once suspected, analgesic nephropathy can be confirmed with relative accuracy using computed tomography (CT) imaging without contrast. One trial demonstrated that the appearance of papillary calcifications on CT imaging