To find scientific articles in biomedical, pharmacological, and clinical topics, use the following databases. Start with PubMed! Most of the time, you'll find what you need there.
Sometimes you already know which article you want without a database. Or sometimes the database won't let you download full text of the article for some reason. In that case, you can use this video to help you find the article through the library's catalog. Note that the library website interface has changed since this video was made. To search for journals, click on the "journal" link under the search box.