Note 4 - Cash, Cash Equivalents and Marketable Securities (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2023

Dec. 31, 2022

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	March 31, 2023		December 31, 2022
Cash in banking institutions	$	631,002	$	1,586,920
Money market funds		14,014,584		8,526,786
Total	$	14,645,586	$	10,113,706

	December 31,
	2022		2021
Cash in banking institutions	$	1,586,920	$	30,308,075
Money market funds		8,526,786		7,005,483
Total	$	10,113,706	$	37,313,558

Debt Securities, Available-for-Sale [Table Text Block]

	Amortized cost		Unrealized gains		Unrealized losses			Fair Value
March 31, 2023
Commercial paper	$	1,995,318		210	$	(1,437	)	$	1,994,091
U.S. treasury bonds		999,575		—		(1,896	)		997,679
Total	$	2,994,893		210	$	(3,333	)	$	2,991,770
December 31, 2022
Commercial paper	$	9,445,220		263	$	(21,313	)	$	9,424,170
U.S. treasury bonds		2,999,095		—		(14,325	)		2,984,770
Total	$	12,444,315		263	$	(35,638	)	$	12,408,940

	Amortized cost		Unrealized gains		Unrealized losses			Fair Value
Commercial paper	$	9,445,220	$	263	$	(21,313	)	$	9,424,170
U.S. treasury bonds		2,999,095		—		(14,325	)		2,984,770
Total	$	12,444,315	$	263	$	(35,638	)	$	12,408,940