We employed BeautifulSoup to convert the markup language into plain text, CDE to segment sentences in a paragraph into individual units, and re and regex to write regular expressions (regexes) to identify the section headings. We applied these expressions to the section titles identified by BeautifulSoup through the tag <ce:section-title>. We notice here that we did not use regexes for abstracts. This section has a specific tag in XML files, either <ce:abstract> or <abstract>, depending on the publisher. We assigned a label "abstract", "introduction", "materials-methods", "discussion", or "conclusion" to every sentence according to the section from which it was extracted. Those to which the section headings were not identified were labeled as "None" and overlooked in our analyses. This process yielded a dataset comprising over 1,4 million sentences, distributed over the five categories aforementioned.