Yin and yang represents cosmic duality in Chinese philosophy. Universe consists of opposing and complementary forces. Yin is feminine, dark, still, negative energy. Yang is masculine, hot, bright, positive energy
Colorless, viscous liquid with faint sweet taste. Miscible with water, acetone, and chloroform. Produced from propylene oxide at 200-220°C or 150-180°C. Annual production reaches 2.16 M tonnes
Saline is a mixture of sodium chloride and water. Normal saline contains 9g NaCl per liter (0.9%). Saline has a pH of 5.5 due to dissolved carbon dioxide
Gua sha is a TCM practice using tools to scrape skin for petechiae. Originated in China, spread to Vietnam as "cạo gió". Term comes from Shang Han Lun medical text from 220 CE
PVP is a water-soluble polymer made from N-vinylpyrrolidone monomer. First synthesized by BASF chemist Walter Reppe in 1939. Soluble in water and other polar solvents. Absorbs up to 40% of its weight in atmospheric water
Blood plasma is a light amber-colored liquid containing proteins and other blood constituents. Makes up about 55% of total blood volume and is 95% water. Contains proteins, glucose, clotting factors, electrolytes, hormones, and oxygen. Has a density of approximately 1,025 kg/m³