Storing a tomato with its stem end facing down can prolong shelf life. "To test this theory, we placed one batch of tomatoes stem-end up and another stem-end down and stored them at room temperature. A week later, nearly all the stem-down tomatoes remained in perfect condition, while the stem-up tomatoes had shriveled and started to mold."
"Placing a tomato stem-end down blocks air from entering and moisture from exiting the scar. To confirm this theory, we ran another test, this time comparing tomatoes stored stem-end down with another batch stored stem-end up, but with a piece of tape sealing off their scars." It worked.