This is a mash-up of Google Charts and the NCBI API (plus a little math) to show relative proportions of Medical Subject Heading Subheadings for a given PubMed results set.
See it in action at: http://esperr.github.io/mesh-subhead-graph/
For more PubMed visualization fun, be sure to check out https://github.com/esperr/mesh-cat-graph and https://github.com/esperr/pubvenn