Word for not recent but not too old

I’m needing a descriptive word that describes both not recent” and “not old” - essentially the latter.

However, I am not wanting to describe a living thing such a person or animal, but rather, academician.

I understand the complexity of this ask, given if there was a word, a quick google search would show a list. However, I’m also optimistic that given the broadness of the English language, a word meaning such would have to exist.

I would be absolutely over the moon if there is a word, but doesn’t use the words I’ve mentioned above, so long as the point comes across.

The syntax I’m currently needing to word for is: “______[ Research highlights the important details of neurological disorders associated with transcriptional-translational feedback loops in RNA”.

Thank you all very much for your time in helping.

I suggest established about which Lexico says

established
ADJECTIVE

1 Having existed or done something for a long time and therefore recognized and generally accepted.

The idea of established implies something that it is not new, but still relevant, and widely accepted as valid.

Established research highlights the important details of neurological disorders associated with transcriptional-translational feedback loops in RNA.