Research articles usually contain:
Research articles are NOT good places to find:
Short articles (also called communications or letters) report research in progress and preliminary results likely to be of interest to the scientific community, and establish priority for the authors in advance of full publication. Some journals publish both short and full articles; others publish only short articles.
Audience: Articles in scientific journals are written by and for experts, not the general public. Since the authors assume you have a fairly solid expertise on the subject, this can make reading articles a bit of a challenge at first. But you'll soon learn how to intelligently scan an article and extract the information you need. Most scientists read the abstract and the conclusions first, then look at the main body of the paper for details of interest.
See also: A Guide to Reading Journal Articles - from the Royal Society of Chemistry