The present invention relates to compounds of formula Ia or Ib below and their tautomers andor pharmaceutically acceptable salts and compositions and methods of uses thereof. A light reflecting plate having a curved surface is disposed in the vicinity of the CCT. The invention also concerns a device for producing a surface structured pipe conduit element using a guidance having embossing elements and which can be rotated about the periphery of the jacket of a pipe conduit element continuously supplied to the device.