Note 16 - Supplemental Disclosure for Statements of Cash Flows

6 Months Ended

Jun. 30, 2018

16.	Supplemental Disclosure for Statements of Cash Flows

During the

six

-month periods ended

June 30, 2018

and

2017,

we paid interest aggregating

$4,000

and

$7.4

million, respectively. During the

six

-month periods ended

June 30, 2018

and

2017,

we issued

94,684

and

105,308

shares of our common stock as matching contributions to our

401

(k) Plan which were valued at

$36,000

and

54,000,

respectively. During the

six

-month period ended

June 30, 2017,

we issued

1.0

million Series NN warrants to UCSD with an estimated fair value of

$334,000.