"Filtration" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings). Descriptors are arranged in a hierarchical structure, which enables searching at various levels of specificity.
MeSH information
A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

This graph shows the total number of publications written about "Filtration" by people in this website by year, and whether "Filtration" was a major or minor topic of these publications.
Bar chart showing 1212 publications over 30 distinct years, with a maximum of 76 publications in 2015
To see the data from this visualization as text, click here.