Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Components of Deferred Tax Assets and Liabilities

The primary components of the deferred tax assets and liabilities at December 31, 2017 and 2016 were as follows (in thousands):

	2017			2016
Deferred liabilities:
Available-for-sale securities	$	-		$	(761	)
Total deferred tax liabilities		-			(761	)

Deferred tax assets:
Net operating loss carryforwards		11,414			11,730
Research and development credit carryforwards		2,141			1,765
Patents and fixed assets		268			179
Stock-based compensation and accrued payroll		1,260			1,041
Valuation Allowance		(15,083	)		(13,954	)
Total deferred tax assets		-			761
Net deferred tax asset (liability)	$	-		$	-

Income Tax Reconciliation

Income taxes differed from the amounts computed by applying the U.S. federal income tax of 34% to pretax losses from operations as a result of the following:

	Year Ended December 31,
	2017			2016			2015
Computed tax benefit at federal statutory rate		34	%		34	%		34	%
Re-rate of federal net deferred tax assets		(35)	%		0	%		0	%
Permanent differences		(8)	%		(1)	%		(9)	%
State tax benefit		3	%		2	%		15	%
Research and development credits		1	%		2	%		2	%
Other		0	%		7	%		3	%
Adjusted basis for available-for-sale-securities		11	%		0	%		0	%
Change in valuation allowance		(6)	%		(44)	%		(45)	%
		-	%		-	%		-	%