Abstract: Provided herein are compounds of the Formula I: and stereoisomers and pharmaceutically acceptable salts or solvates thereof, in which A, B, X1, X2, X3, X4, Ring D, and E have the meanings given in the specification, which are inhibitors of RET kinase and are useful in the treatment and prevention of diseases which can be treated with a RET kinase inhibitor, including RET-associated diseases and disorders.

Abstract: A fluid drive conversion system having a plurality of flat foils rotatably connected to a vertical shaft such that the foils are generally vertical in position, pivot about a vertical axis, are a predefined distance, at least about one quarter of the width of a foil, from the vertical shaft thereby creating a central space. In operation, fluid flows through the central space and simultaneously pushes the back side of at least one foil while pushing the front side of one or more remaining foils, resulting in all of the foils rotating about the vertical shaft and contributing to the generation of usable energy. A wing is pivotally connected to the distal end of each radial arm and a bottom radial arm wherein each wing is in a general vertical orientation. The fluid drive conversion system employs either a conventional gear system, a conventional pulley system, or an electrical generation assembly using magnets, coils, and a means for harnessing an electrical current.