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The familiar sounds of your heart are made by the heart's valves as they open and close.
Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.
A headache when you wake up in the morning is indicative of sinusitis. Other symptoms of sinusitis can include fever, weakness, tiredness, a cough that may be more severe at night, and a runny nose or nasal congestion.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.
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