Note 2 - Summary of Significant Accounting Policies (Details Textual)		1 Months Ended	12 Months Ended
	Apr. 03, 2018 $ / shares shares	Dec. 31, 2013 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Mar. 31, 2018 $ / shares shares
Stockholders' Equity Note, Stock Split, Conversion Ratio	6.6841954
Capital Stock, Shares Authorized | shares							210,000,000
Common Stock, Shares Authorized | shares	200,000,000		200,000,000	200,000,000			200,000,000
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.001		$ 0.001	$ 0.001			$ 0.001
Preferred Stock, Shares Authorized | shares	10,000,000						10,000,000
Preferred Stock, Par or Stated Value Per Share | $ / shares			$ 0.001				$ 0.001
Cash Equivalents, at Carrying Value, Total			$ 0
Cash, Uninsured Amount			1,761,278	$ 8,465,768
Research and Development Assets, Current			801,780	0
State of Texas Emerging Technology Fund Award Amount						$ 4,500,000
Proceeds from State of Texas Emerging Technology Fund Award					$ 2,250,000	2,250,000
Revenues, Total
Fair Value Adjustment of Warrants		$ 2,500,000	0
Impairment of Long-Lived Assets Held-for-use			$ 0	$ 0
Grant [Member] | U.S. Treasury Department [Member]
Revenues, Total						$ 244,500
Minimum [Member]
Property, Plant and Equipment, Useful Life			3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life			5 years