An apparatus for planarizing a work piece includes an easily assembled work carrier. The display apparatus comprises an adjusting device, which acquires image brightness data, and adjusts the number of subfields Z on the basis of brightness data. The first surface is a three-dimensional patient-specific surface that closely matches and can mate to a substantially unaltered and unresected surface of a bone defect of the specific patient only in one position. The second band-pass filter has first to third parallel resonators. In a fifth step, a joint zone 20 is formed between the first and second breast milk absorbent pads 2, 3 and these two pads 2, 3 is cut apart along a cutting line 33. The invention further relates to a spirulin biomass rich in sulfolipids which has an inhibitory activity towards HIV-1 and HIV-2 reverse transcriptase, and to the use of said sulfolipids, or of an extract of spirulin biomass rich in sulfolipids, for the preparation of a drug for the prophylactic or curative treatment of AIDS.