The present invention features a human neurogenin3 polypeptide and nucleotide sequences encoding Ngn3 polypeptides. The nanorod array may be fabricated on top of a conducting layer that serves as a bottom contact to the nanorods. A void is formed in the tube at or near the proximal end of the tube. Projecting portions are formed at portions of the circumferential edge portion which are brought into abutment with one surface of each of the locking pieces. The invention furthermore relates to processes for preparing the compounds of the formula I, to their use and to pharmaceutical preparations which comprise compounds of the formula I.