Note 9 - Stockholders' Equity and Common Stock Warrants - Warrants Outstanding to Acquire Shares of Its Common Stock (Details)	Mar. 31, 2024 $ / shares shares
Warrants outstanding (in shares) | shares	102,462
Historical Diffusion Common Stock Warrants [Member]
Warrants outstanding (in shares) | shares	58,844
Historical Diffusion Common Stock Warrants [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 26.27
Historical Diffusion Common Stock Warrants [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 459.06
Historical EIP Common Stock Warrants [Member]
Warrants outstanding (in shares) | shares	43,618
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 19.81