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Leonardo da Vinci (1452-1519), Italian Renaissance painter from Florence. Engraving by Cosomo Colombini (d. 1812) after a Leonardo self portrait. Ca. 1500.
10 Famous Artworks by Leonardo da Vinci
Andrew Jackson delivering a speech while on his way to Washington, D.C., for his inauguration in 1829. From Harper's Weekly, 1881.
5 Remarkably Close U.S. Presidential Elections
Vincent Van Gogh, Self Portrait. Oil on canvas, 1887.
Rediscovered Artists: 6 Big Names That Time Almost Forgot
David Cameron. President Barack Obama and Prime Minister David Cameron of the United Kingdom talk during the G8 Summit at the Lough Erne Resort in Enniskillen, Northern Ireland, June 17, 2013
What’s the Difference Between a President and a Prime Minister?
Close up of books. Stack of books, pile of books, literature, reading. Homepage 2010, arts and entertainment, history and society
12 Novels Considered the “Greatest Book Ever Written”
Statue of Nostradamus
Nostradamus and His Prophecies
Election - Button that says Vote. Badge pin stars and stripes politics campaign
Why Are U.S. Elections Held on Tuesdays?

Optisol

sunscreen

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nanoparticles

  • Image showing nanoparticles of an alloy of gold (yellow) and palladium (blue) on an acid-treated carbon support (gray). These particles were employed as catalysts for the formation of hydrogen peroxide from hydrogen (white) and oxygen (red).
    In nanoparticle: Nanoparticle applications in medicine

    …example, a sunscreen known as Optisol, invented at the University of Oxford in the 1990s, was designed with the objective of developing a safe sunscreen that was transparent in visible light but retained ultraviolet-blocking action on the skin. The ingredients traditionally used in sunscreens were based on large particles of…

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