Note 6 - Equity - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Outstanding, number of shares (in shares)	151,690
Outstanding, weighted average grant date fair value (in dollars per share)	$ 66.6
Outstanding, weighted average exercise price (in dollars per share)	$ 87.45
Outstanding, weighted average remaining contractual term (Year)	7 years 10 months 24 days	7 years 9 months 18 days
Outstanding, aggregate intrinsic value	$ 378,606	$ 0
Granted, number of shares (in shares)	101,400
Granted, weighted average grant date fair value (in dollars per share)	$ 7.35
Granted, weighted average exercise price (in dollars per share)	$ 9
Forfeited, number of shares (in shares)	(3,610)
Forfeited, weighted average grant date fair value (in dollars per share)	$ 9.15
Forfeited, weighted average exercise price (in dollars per share)	$ 11.1
Expired, number of shares (in shares)	(56)
Expired, weighted average grant date fair value (in dollars per share)	$ 157.5
Expired, weighted average exercise price (in dollars per share)	$ 224.1
Outstanding, number of shares (in shares)	249,424	151,690
Outstanding, weighted average grant date fair value (in dollars per share)	$ 43.35	$ 66.6
Outstanding, weighted average exercise price (in dollars per share)	$ 56.7	$ 87.45
Exercisable, number of shares (in shares)	93,337
Exercisable, weighted average grant date fair value (in dollars per share)	$ 88.65
Exercisable, weighted average exercise price (in dollars per share)	$ 119.4
Exercisable, weighted average remaining contractual term (Year)	6 years 1 month 6 days
Exercisable, aggregate intrinsic value	$ 0