Pulmonary embolism is the sudden blockage of a major blood vessel (artery) in the lung, usually by a blood clot . In most cases, the clots are small and are not deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly.
The term chiaroscuro (from the Italian words chiaro, meaning light, and scuro, meaning dark) refers to the use of light and shade in a work of art to define three-dimensional objects. Masters of this technique were the Italians Leonardo da Vinci and Caravaggio and the Dutch painter Rembrandt.
Chiaroscuro in the manner of Jan van Eyck is a prominent feature of the Annunciation that was originally the central panel of a triptych. Although the two wings of the altarpiece are not by the painter of the central panel, they try to achieve the atmospheric effects of light and shade seen in van Eyck's paintings.