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.
1 Any non-racemic chiral substance is called scalemic. 2  A chiral substance is enantiopure or homochiral when only one of two possible enantiomers is present. 3  A chiral substance is enantioenriched or heterochiral when an excess of one enantiomer is present but not to the exclusion of the other.