Note 14 - Stock Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

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

	Three Months Ended June 30,			Six Months Ended June 30,
	2022			2022
Risk-free interest rate	2.87%	-	3.02%	1.86%	-	3.02%
Expected term (in years)	5.19	-	6.11	5.19	-	6.11
Dividend yield		-			-
Expected volatility	114%	-	126%	114%	-	128%

	Three Months Ended June 30,			Six Months Ended June 30,
	2021			2021
Risk-free interest rate	0.89%	-	1.08%	0.89%	-	1.08%
Expected term (in years)	5.31	-	6.17	5.31	-	6.17
Dividend yield		-			-
Expected volatility	122%	-	130%	122%	-	130%

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

	Number of Underlying Shares		Weighted- Average Exercise Price Per Share		Weighted- Average Contractual Life Remaining in Years		Aggregate Intrinsic Value
Outstanding as of January 1, 2022		10,027	$	2.82		-
Granted		3,849		1.16		-		50,738
Exercised		-		-		-
Forfeited		-		-		-
Expired		-		-		-		-
Outstanding as of June 30, 2022		13,876		2.35		8.31	$	183
Exercisable as of June 30, 2022		8,418		2.72		7.60
Vested and expected to vest		13,876	$	2.35		8.31	$	183

Share-Based Payment Arrangement, Option [Member]

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
General and administrative	$	1,140	$	853	$	2,323	$	1,303
Research and development		631		361		1,254		551
Total stock compensation expense	$	1,771	$	1,214	$	3,577	$	1,854