From the Elsevier factsheet [pdf]:

Elsevier and ScienceDirect have partnered with NextBio to provide
researchers with text-mining tools and research data from high-
quality publicly available sources of information.

This enhancement on ScienceDirect provides researchers with
intelligent connections extracted from ScienceDirect content
(published from 1995) as well as ScienceDirect peer-reviewed
literature together with publicly available research data as compiled
by NextBio. These research data sources include PubMed, clinical
trials, experimental data correlations and news articles.

Further info, including a tutorial, is available.