CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (3,707,447)	$ (9,842,672)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	18,175	21,081
Unrealized currency gain on short-term investments	(31,004)	(54,551)
Gain on equipment disposal	(35,649)	(6,727)
Change in value of warrant liability	(962,818)	4,426,146
Changes in operating assets and liabilities:
Accounts receivable and other current assets	431,324	(144,443)
Other long-term assets	(164)	0
Accounts payable and accrued expenses	(325,832)	(1,010,293)
Net cash used in operating activities	(4,613,415)	(6,611,459)
Cash flows from investing activities:
Purchase of short-term investments	(7,737,132)	(8,631,685)
Sale of short-term investments	11,695,498	12,515,024
Proceeds from sale of equipment	36,145	8,956
Purchase of equipment	(27,877)	(4,404)
Net cash provided by investing activities	3,966,634	3,887,891
Cash flows from financing activities:
Exercise of warrants	55,215	0
Net cash provided by financing activities	55,215	0
Effect of exchange rate change on cash and equivalents	(21,748)	52,300
Decrease in cash and cash equivalents	(613,314)	(2,671,268)
Cash and cash equivalents at beginning of period	4,230,548	6,901,816
Cash and cash equivalents at end of period	3,617,234	4,230,548
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	0	0
Supplemental schedule of non-cash financing activities:
Cashless exercise of warrants	$ 0	$ 4,334,110