Note 10 - Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended March 31,
	2021			2020
Numerator
Net loss attributable to common shareholders	$	(3,538,069	)	$	(2,947,420	)
Denominator
Weighted average common shares outstanding used to compute net loss per share, basic and diluted		92,587,168			9,130,984
Net loss per share of common stock, basic and diluted:	$	(0.04	)	$	(0.32	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Three Months Ended March 31,
	2021		2020
Options to purchase common stock		7,067,436		4,308,383
Series B convertible preferred stock		177,373		190,617
Warrants to purchase common stock		25,076,714		1,070,028
		32,321,523		5,569,028