Note 9 - Stockholders' Equity and Common Stock Warrants - Warrants Outstanding to Acquire Shares of Its Common Stock (Details)	Jun. 30, 2025 $ / shares shares
Warrants outstanding (in shares) \| shares	2,601,671
Historical Diffusion Common Stock Warrants [Member]
Warrants outstanding (in shares) \| shares	25,768
Historical Diffusion Common Stock Warrants [Member] \| Minimum [Member]
Warrants, exercise price (in dollars per share) \| $ / shares	$ 44.55
Warrants, maturity date	May 01, 2025
Historical Diffusion Common Stock Warrants [Member] \| Maximum [Member]
Warrants, exercise price (in dollars per share) \| $ / shares	$ 96.12
Warrants, maturity date	Feb. 28, 2026
Historical EIP Common Stock Warrants [Member]
Warrants outstanding (in shares) \| shares	43,618
Warrants, exercise price (in dollars per share) \| $ / shares	$ 19.81
Warrants, maturity date	Apr. 30, 2028
Series A Common Stock Warrants [Member]
Warrants outstanding (in shares) \| shares	2,532,285
Warrants, exercise price (in dollars per share) \| $ / shares	$ 39.24
Warrants, maturity date	Apr. 30, 2027