upright|thumb|150px|Schematic of size-based membrane exclusion
upright|thumb|150px|Schematic of size-based membrane exclusion
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Biological membranes include cell membranes (outer coverings of cells or organelles that allow passage of certain constituents); nuclear membranes, which cover a cell nucleus; and tissue membranes, such as mucosae and serosae. Synthetic membranes are made by humans for use in laboratories and industry (such as chemical plants).
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).