This is likely an OCR (Optical Character Recognition) error or a shorthand citation for a specific volume and page range of a medical journal from 1913.
The term ".7z" is a standard file extension for the 7-Zip compression format . MED.7z
In technical student papers or computer science research, 7z is often compared to other formats like RAR or ZIP for its superior compression ratios. This is likely an OCR (Optical Character Recognition)
A file named MED.7z could be a compressed archive containing research data, a manuscript draft, or supplementary materials for a medical ("MED") paper. a manuscript draft
It often appears in papers discussing leukemia treatments or folic acid antagonists , citing earlier work from the early 20th century. 2. Compressed Data File