Abstract: The invention relates to an adapter (10?) for connecting at least two plastic bottles (A, B), preferably PET bottles, the screw connections (2) of which are screwable into corresponding threaded receptacles (11, 12) of the adapter (10?). In order to produce a compact water purifying or water treatment system, a first flow path (D) is formed in the adapter (10?), which flow path establishes a flow connection for water vapour from a first threaded receptacle (11) to a second threaded receptacle (12), wherein a plastic bottle (A) filled at least partly with waste water is insertable into the first threaded receptacle (11) and an empty plastic bottle (B) is insertable into the second threaded receptacle (12), wherein a second flow path (K) for collecting and discharging condensed water out of the empty plastic bottle (B) is formed in the adapter (10?).

Abstract: The invention relates to a device for the transcutaneous, in vivo measurement of the concentration of at least one analyte in a living organism, comprising a carrier which can be introduced into the organism, and a luminescence indicator which is immobilized on the carrier and which reacts to a change in the concentration of the analyte to be measured with a change in at least one optical property, wherein the luminescence indicator is transcutaneously connected to a source for providing the excitation radiation and a detector for detecting the measuring radiation. According to the invention, the luminescence indicator is immobilized on the outer circumference of a catheter, which is used to dispense a fluid medium, for example a medicament, into the organism or to suck up a body fluid.