In a method of testing an electrode structure in which a plurality of electrodes are arranged in a matrix, a test unit is positioned at a position of a target one of the plurality of electrodes apart from the target electrode by a preset distance. Using the system, a same-day on-demand delivery order may be placed by phone or through a web site. Radiation or X-ray source assembly methods andor apparatus embodiments can provide mobile radiography carts a capability to direct x-ray radiation towards a subject from one or a plurality of different source positions, where the X-ray source assembly includes a first x-ray power source and a second plurality of distributed x-ray sources disposed in a prescribed spatial relationship. The inactive portions are provided on both sides of the active portion. The optical system, can be designed to have a wavelength-dependent focus that matches the position of each of the light modulating layers. In addition, the present invention relates to a dermatologic composition for external use, which comprises an elastase inhibitor or neutral endopeptidase inhibitor, and the above-described component andor at least one proteolytic enzyme selected from the group consisting of papain, trypsin, chymotrypsin, pepsin, bromelain, ficin and pancreatin.