A file is a "Roshal Archive," a proprietary compressed file format used to bundle one or more files into a single, smaller container.

a review of off-label applications for inflammatory skin diseases

Based on common naming conventions in digital archives, this file might be related to:

: Every RAR file begins with a "magic number" hex signature: 52 61 72 21 1A 07 00 (for versions 1.5 to 4.0) or 52 61 72 21 1A 07 01 00 (for RAR 5.0+).