From a Europe PMC Blog Post:
Scite, an award-winning citation analysis platform, and Europe PMC, an open science discovery tool that provides access to a worldwide collection of life science publications, have partnered to display what scite calls smart citations on the Europe PMC platform.
Smart citations advance regular citations by providing more contextual information beyond the information that one study references another. Specifically, smart citations provide the excerpt of text surrounding the citation, the section of the article in which the reference is mentioned, and indicate whether the citing study provides supporting or contradicting evidence. As a result, one can evaluate a study of interest much faster.
Scite has been collecting the information required for smart citations from open access sources as well as through partnerships with such publishers as Wiley, the BMJ, and Future Science group and others yet to be announced. Currently, the scite database has 450M citation statements extracted from 14M publications that cite 31M articles
See Also: Direct to Scite Web Site