Note 11 - Stockholders' Equity, Stock Options and Warrants (Tables)

9 Months Ended

Sep. 30, 2024

Notes Tables

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Nine Months Ended September 30,
	2024		2023
	Stock Options
Expected dividend yield		-		0.0%
Expected stock price volatility		-		90.8% – 91.6%
Risk-free interest rate		-		3.38% – 3.72%
Expected life		-		10 years
	Warrants
Expected dividend yield		0.0%		-
Expected stock price volatility		97.3%		-
Risk-free interest rate		4.06% – 4.58%		-
Expected life		1.5 – 5 years		-

Share-Based Payment Arrangement, Activity [Table Text Block]

	Stock Options					Warrants
	Number of Shares			Average Exercise Price		Number of Shares			Average Exercise Price
Outstanding as of December 31, 2023		47,664		$	82.23		1,806,589		$	21.52
Issued		-			-		1,983,302			1.09
Forfeited		(309	)		5.04		-			-
Expired		(2,164	)		3.03		(81,346	)		37.90
Exercised		-			-		(958,117	)		1.32
Outstanding as of September 30, 2024		45,191		$	86.55		2,750,428		$	8.92