Note 17 - Warrant Liabilities (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

Schedule of Warrant Liabilities [Table Text Block]

	As of		As of		As of		Change in Fair Value (gain)/loss
	June 30, 2019		March 31, 2019		December 31, 2018		Six Months Ended June 30, 2019			Three Months Ended June 30, 2019
Fair value of the Warrants:
Investor warrants		32		793		503		(471	)		(761	)
Placement agent warrants		103		163		103		-			(60	)
Warrant liabilities		135		956		606		(471	)		(821	)

	As of		As of		As of		Change in Fair Value (gain)/loss
	June 30, 2018		March 31, 2018		January 17, 2018		Six Months Ended June 30, 2018			Three Months Ended June 30, 2018
Fair value of the Warrants:
Investor warrants		1,103		664		1,890		(787	)		439
Placement agent warrants		224		137		385		(161	)		87
Warrant liabilities		1,327		801		2,275		(948	)		526

Schedule of Warrant Activity [Table Text Block]

	Warrant Outstanding						Warrant Exercisable
	Number of underlying shares		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number of underlying shares		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price
Balance, January 1, 2019		774,000		1.63	$	6.60		774,000		1.63	$	6.60
Granted/Vested		-						-
Forfeited		-						-
Exercised		-						-
Balance, June 30, 2019 (Unaudited)		774,000		1.13	$	6.60		774,000		1.13	$	6.60

Warrant [Member]

Notes Tables

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

	Investors warrants									Placement agent warrants
	December 31, 2018			March 31, 2019			June 30, 2019			December 31, 2018			March 31, 2019			June 30, 2019
Stock price	$	1.34		$	1.95		$	1.35		$	1.34		$	1.95		$	1.35
Years to maturity		1.55			1.30			1.10			2.05			1.80			1.55
Risk-free interest rate		2.50	%		2.27	%		1.73	%		2.50	%		2.27	%		1.73	%
Dividend yield		-			-			-			-			-			-
Expected volatility		199	%		216	%		90	%		176	%		187	%		202	%
Exercise Price	$	6.60		$	6.60		$	6.60		$	6.60		$	6.60		$	6.60
Fair value of the warrant	$	0.78		$	1.23		$	0.05		$	0.80		$	1.26		$	0.80

	Investors warrants									Placement agent warrants
	January 17, 2018			March 31, 2018			June 30, 2018			January 17, 2018			March 31, 2018			June 30, 2018
Stock price	$	3.98		$	1.67		$	2.52		$	3.98		$	1.67		$	2.52
Years to maturity		2.50			2.30			2.10			3.00			2.80			2.55
Risk-free interest rate		2.22	%		2.35	%		2.53	%		2.39	%		2.50	%		2.56	%
Dividend yield		-			-			-			-			-			-
Expected volatility		158	%		164	%		174	%		147	%		152	%		159	%
Exercise Price	$	6.60		$	6.60		$	6.60		$	6.60		$	6.60		$	6.60
Fair value of the warrant	$	2.93		$	1.03		$	1.71		$	2.99		$	1.06		$	1.74