Bims is entirely dependent on PubMed. Thomas Krichel built a bespoke indexer for PubMed, called pumex. Every Sunday morning, we use that system to calculate all the new additions to PubMed during the week.

“New” means that

1. the PubMed identifier has not been seen before and;
2. the document that the PubMed record describes appears to be less than two years old … well, as far as the software can figure it out.

We exclude

• papers without an <ArticleTitle> element
• papers with an empty <ArticleTitle> element

There are about 20000 to 25000 additions every week.