5. Accrued Expenses and Other Current Liabilities - (Details - Schedule of Accrued Expenses) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities and Other Liabilities [Abstract]
Compensation and benefits	$ 618	$ 524
Professional fees	81	171
Research and development costs	549	242
Other	104	27
Total accrued expenses and other current liabilities	$ 1,352	$ 964