Gout causes a painful, swollen joint that's so severe that the weight of bed sheets can cause distress. There may also be more than one joint affected with gout. With gout, uric acid -- a normal chemical in the body -- forms crystals that deposit in the joints, causing inflammation and pain.
China has been the source of many innovations, scientific discoveries and inventions. This includes the Four Great Inventions: papermaking, the compass, gunpowder, and printing (both woodblock and movable type). The list below contains these and other inventions in China attested by archaeology or history.
The Song dynasty (Chinese: å®æ; 960â1279 CE) provided some of the most significant technological advances in Chinese history, many of which came from talented statesmen drafted by the government through imperial examinations. The ingenuity of advanced mechanical engineering had a long tradition in China. The Song engineer Su Song admitted that he and his contemporaries were building upon the achievements of the ancients such as Zhang Heng (78â139), an astronomer, inventor, and early master of mechanical gears.