In January, the PDB contained more than 170,000 structures; ~ 150,000 had corresponding "primary citations" describing these entries in a peer-reviewed journal.

The National Library of Medicine assigns MeSH (Medical Subject Headings) from a controlled vocabulary to index articles for PubMed. MeSH terms usually appear in a hierarchical tree structure that begins with 16 main branches.

PDB Citation MeSH Network Explorer flattens these trees into co-occurrence networks of MeSH terms associated with PDB entries. Each node in the chart is a post, and the nodes are linked when they share MeSH terms.

Posts that share similar MeSH terms are grouped into Groups; the largest groups are color-coded. Depending on the size of the network, the groups contain at least one, two, or three common MeSH terms. Clicking on a node reveals information about the publication, the clustered group, and related PDB structures. Nodes that have several terms in common are located close to each other; nodes that have less in common are further apart.

This new way of viewing MeSH terms can provide insight into the relationships between PDB primary citations.

This MeSH Explorer has been developed for RCSB PDB by Digital Science and is powered by Dimensions, the world's largest linked research information dataset.