Abstract: Autofluorescence is the inherent emission of light from cells or tissues that occurs when biological samples are exposed to different wavelengths of excitation light. Tissue autofluorescence is usually ascribed to biological components such as flavins, porphyrins, chlorophyll (in plants), collagen, elastin, red blood cells (RBCs), and lipofuscin. Tissue autofluorescence often presents a significant problem in microscopy, pathology, and surgical applications. Autofluorescence interferes and complicates signal detection in a variety of fluorescence microscopy methods. Tissue autofluorescence reduces the signal detection sensitivity, and in some cases may cause failure in the detection of fluorescent dye signals. Accordingly, there is a need for further improved methods to decrease the autofluorescence intensity from microscopy samples both in research and clinical venues.

Abstract: An excavator includes a mobile chassis with a first bucket drum and a second bucket drum coupled thereto. The first bucket drum and second bucket drum are coupled to the chassis for positioning thereof on the surface at opposing ends of the chassis. Each first scoop on the first bucket drum is a mirror image of one second scoop on the second bucket drum when (i) the first bucket drum and second bucket drum are on the surface adjacent opposing ends of the chassis, and (ii) the first bucket drum is rotated in one direction and the second bucket drum is simultaneously rotated in an opposing direction.