XML 28 R17.htm IDEA: XBRL DOCUMENT v3.8.0.1
Note 5 - Convertible Preferred Stock, Common Stock and Common Stock Warrants (Tables)
3 Months Ended
Mar. 31, 2018
Notes Tables  
Schedule of Warrants Outstanding to Acquire Shares of Common Stock [Table Text Block]
   
Outstanding
   
Range of
exercise price
per share
 
Expiration dates
Common stock warrants issued before 2016
   
430,721
   
$20.00
-
$49.00
 
2018 through 2019
Common stock warrants issued in Series A
   
13,555,887
   
 
$2.22
 
 
March 2022
Common stock warrants issued in 2018 related to the common stock offering
   
17,720,625
   
$0.80
-
$1.00
 
January 2023
     
31,707,233