The invention is based on the discovery that angiogenic vessels have heterogeneous surface charge and that cationic liposomes actually target human tumor blood vessels only in irregularly shaped patches. In this case, reference instants at which a voltage present across the switch corresponds to a first reference voltage value or at which a voltage present across the primary coil corresponds to a second reference voltage value are detected and counted, the switch being closed again only after the number of detected reference instants has reached a comparison numerical value. A spacer is formed around the temporary gate structure. The output and the dynamic node may both be at a logic one when the output is a logic one from the previous evaluation cycle and the dynamic node is precharged.