When did Pascal Cotte restore the Mona Lisa?

Pascal Cotte did not restore The Mona Lisa; rather, he is known for his detailed scientific analysis of the painting. In 2004, he developed a high-resolution imaging technique called "Layer Amplification Method," which allowed him to examine the artwork's layers and uncover details about its creation. His work revealed new insights into Leonardo da vinci's techniques and the painting's condition, but it did not involve physical restoration of the artwork itself.