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10. Stock-Based Compensation (Details 2) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Dividend-yield	0.00%	0.00%
Risk-free interest rate	0.84%	2.13%
Expected volatility	108.80%	103.00%
Expected life (years)	2 years	2 years
Market value per share on grant date	$ 0.81	$ 0.73
Equity Option
Dividend-yield	0.00%	0.00%
Risk-free interest rate	0.94%	2.38%
Expected volatility	87.37%	88.54%
Expected life (years)	6 years 6 months 18 days	6 years 6 months 18 days
Market value per share on grant date	$ 0.69	$ 0.78
Weighted average fair value per share of common stock	$ 0.51	$ 0.59

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