Text Analyzer from JSTOR Labs lets you upload a document and search for articles based on your text.
The tool analyzes the text within the uploaded document to find key topics and terms used, it prioritizes some terms, and then finds similar content in JSTOR. You can add, remove or adjust the importance of the prioritized terms. JSTOR will not store the document you upload.
This new feature is a beta version that is still being tested. The final version of this feature has not been released yet.