For Northwestern affiliates, to authenticate via Northwestern's databases to find the full text, you can go to Edit -> Preferences and click on Find Full Text. To sync with library databases, add one of the following settings (the second set works slightly better at finding full text, but the first one works too!):
Open URL Path: http://resolver.library.northwestern.edu/nwu
Authenticate URL: http://turing.library.northwestern.edu/
Authenticate URL: http://turing.library.northwestern.edu/login?url=
Note that Find Full Text works much better from on-campus. For off-campus users, connect to the virtual private network (VPN) to simulate being on campus.