Online full-text content began in 1999, and expands with each month's new issues.

Each issue is placed online approximately on the date it is mailed to subscribers, so the online site may be days or even weeks ahead of your receipt of a paper copy.

In addition, future tables of contents are available online and you can request email notification with several options.

The web site also provides access to information about the journals (such as Instructions to Authors, the Editorial Boards, and subscription information and on-line subscription registration), as well as access to other services.

Access to full content is controlled by institutional site license, which comes with all institutional subscriptions.

We encourage you, on your first visit to the site, to sign the guestbook. This will take only a minute or two, and will give us helpful information about who the online readers are, and how they are connecting to us. In addition, we would appreciate comments, critiques, questions, or suggestions from you; these can be sent via the Feedback button found on all pages of the site. Feedback from readers will help us decide what new features would be most valuable for the site, and how well it is working for its readers.

The site is being produced in conjunction with Stanford University's HighWire Press, the world's premiere online biomedical resource. A list of online journals and URLs is available at:

http://highwire.stanford.edu