Disclosed are systems, methods and computer program products for reducing security risk in a computer network. In this method, a figure pattern consisting of plural concentric circles is formed on a reference sample \u201cWP\u201d and an image is formed based on an electron signal obtained by scanning the electron beam onto the reference sample \u201cWP\u201d. The lead is further designed to include an internal lumen for use with a guidewire in an over-the-wire lead placement. The anode material for a secondary battery of the present invention may be produced by coating a high-crystallinity core carbonaceous material with a coating carbonaceous material and undergoing a predetermined calcination process, and the anode material can have an increased volume ratio of the micropores. The signal generating circuit may include a plurality of delay circuits coupled to provide a plurality of control signals, a weighted-sum circuit to receive the plurality of control signals and to provide an output analog signal, and a comparator circuit to compare the output analog signal with a voltage and to provide a pulse width modulated signal based on the comparison. The RNA virus comprises, in part, an ion channel protein comprising a peptide tag.