Note 10 - Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

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

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Numerator
Net loss attributable to common shareholders	$	(7,039,248	)	$	(3,906,142	)	$	(10,577,317	)	$	(6,853,562	)
Denominator
Weighted average common shares outstanding used to compute net loss per share, basic and diluted		121,572,091			9,187,588			107,159,698			9,159,286
Net loss per share of common stock, basic and diluted:	$	(0.06	)	$	(0.43	)	$	(0.10	)	$	(0.75	)

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Options to purchase common stock		8,905,274		5,993,823		7,991,432		5,151,103
Series B convertible preferred stock		175,335		182,520		176,348		186,568
Warrants to purchase common stock		26,918,409		1,070,028		26,002,649		1,070,028
		35,999,018		7,246,371		34,170,429		6,407,699