A radionuclide scanner in which multiple detectors are equipped with collimators such that a circular rotation of the detector around a target provides the movement needed for collimator sampling. The invention further discloses a method in a PoC service of notifying of a message in a voice mailbox, and a PoC service server. The invention also includes a corresponding operating method. The anode and the high-resistance film, and the cathode and the high-resistance film each contain the same metal or semiconductor element and have different resistant values. A delay circuit is operable to insert a delay between the envelope signal and the data signal as a function of the resource block allocation within the channel, thereby intentionally causing unbalanced leakage about the resource block allocation. A light-emitting device according to a preferred embodiment of the disclosure comprises: a frame portion having a bottom and a sidewall; a light-emitting portion which is disposed on the frame portion and emits light; and a window portion disposed over the frame portion so as to cover the light-emitting portion.