Disc mode allows you to discriminate a bit and look for specific metals. (geekwrapped.com)
Previously developed reporter genes for MRI have been much more limited in their capabilities, requiring the use of specific metals that are not always available in some tissues. (caltech.edu)
Similar non-homogeneously charged units appear either in biosystems, e.g. viral capsids and proteins, or in experimentally synthesized systems, e.g. virus - like nano - particles, spotted vesicles and nano - cubes covered with specific metals. (sciencedaily.com)