Note 5 - Share-based Compensation - Noncash Stock Option Compensation (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Stock-based compensation	$ 281,307	$ 499,919	$ 946,262	$ 1,408,210
Share-Based Payment Arrangement, Option [Member]
Stock-based compensation	224,749	499,919	779,663	1,408,210
Restricted Stock Units (RSUs) [Member]
Stock-based compensation	56,558	0	166,599	0
General and Administrative Expense [Member]
Stock-based compensation	270,672	441,279	913,804	1,219,827
Research and Development Expense [Member]
Stock-based compensation	$ 10,635	$ 58,640	$ 32,458	$ 188,383