v3.23.1
Note 8 - Warrants (Tables)
3 Months Ended
Mar. 31, 2023
Notes Tables  
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]
  

Common
Stock from

Warrants

  Weighted-
average
Exercise
Price
(per share)
 

Outstanding at December 31, 2022

  7,824,933  $1.72 

Pre-funded warrants exercised

  2,632,898  $0.0001 

Outstanding at March 31, 2023

  5,192,035  $2.59 

Exercisable at March 31, 2023

  964,983  $4.89