Methods and apparatus for treating fractures of the distal femur are disclosed. The AC and DC responses are measured; a corrected DC response is determined using the AC response; and a concentration of the analyte is determined based upon the corrected DC response. The test image includes an image of one or more patterned features formed on the specimen proximate to a defect detected on the specimen. The layer of the first conductivity type is electrically connected through the cutout by means of a first electrical connection layer which covers the rear side of the semiconductor layer sequence at least in places. Then, thinning the film includes thinning the film to a third thickness equal to the first thickness minus the depth. Such manufactured item may have the shape of small bricks, bricks, blocks, small blocks, kerbs, interlocking paving blocks, panels, tiles, prefabricated slabs, beams, elements for walls, modular building elements, indoor and outdoor cladding elements, blocks, rocks, supports.