A polymer light emitting element having a large light releasing surface, a high light emitting efficiency and a long life, a polymer light emitting display device and planar light source, as well as a method for manufacturing the polymer light emitting element are provided. Thereby, the rotation of the input shaft drives the inner threaded gear to rotatably slide about the spiral outer periphery to force the gears of the speed changing shaft to rotate and in turn to drive the gears of the output shaft to rotate in concert with the input shaft. Assay plates, caps, kits, and other devices and methods relating to high throughput magnetic sensing are also disclosed. Numerous methods are also provided by the system that receive, store and retrieve reviews.