Period 6 element living organism. Tungsten interferes with molybdenum and copper metabolism, and is somewhat toxic to animal life. Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an "estimated" average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. The free element has the third-highest melting point and highest boiling point of any element. Rhenium resembles manganese chemically and is obtained as a by-product of molybdenum and copper ore's extraction and refinement. Rhenium
Wolfram Saenger Wolfram Saenger Wolfram Saenger (born 1939) is a German biochemist and protein crystallographer. In his research career spanning over 30 years he has worked at the Max Planck Institute for Experimental Medicine, Harvard University (Harvard Medical School) and the Free University of Berlin, where he led the Institute for Crystallography research until his retirement in 2011. A recipient of the Gottfried Wilhelm Leibniz Prize (1987) of the Deutsche Forschungsgemeinschaft, which is the highest honor awarded for achievements in research in Germany, and the Humboldt Prize (1988), he is best known for his research on X-ray crystallography of membrane proteins and