Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (28,962,000)	$ (19,445,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	39,000	38,000
Redeemable warrants valuation adjustment		(35,000)
Gain on sale of fixed assets	(18,000)
Abandonment and expiration of patents and trademark rights	14,000
Amortization of patent and trademark rights	199,000	218,000
Non-cash lease expense	287,000	(680,000)
Loss from sale of income tax operating losses		197,000
Equity-based compensation	243,000	954,000
Loss (gain) on sale of marketable investments	(200,000)	1,679,000
Change in assets and liabilities:
Funds receivable from New Jersey operating loss sales	492,000	(35,000)
Prepaid expenses and other current assets	153,000	(151,000)
Lease liability	(274,000)	688,000
Other assets	(486,000)	(83,000)
Accounts payable	6,066,000	179,000
Accrued expenses	1,180,000	368,000
Net cash used in operating activities	(21,267,000)	(16,108,000)
Cash flows from investing activities:
Proceeds from sale of marketable investments	1,299,000	10,083,000
Purchase of marketable investments	(1,593,000)	(2,724,000)
Purchase of property and equipment		(86,000)
Proceeds from sale of property and equipment	47,000	3,900,000
Purchase of patent and trademark rights	(585,000)	(185,000)
Net cash (used in) provided by investing activities	(832,000)	10,988,000
Cash flows from financing activities:
Proceeds from sale of stock, net of issuance costs	485,000	80,000
Net cash provided by financing activities	485,000	80,000
Net decrease in cash and cash equivalents	(21,614,000)	(5,040,000)
Cash and cash equivalents at beginning of year	27,053,000	32,093,000
Cash and cash equivalents at end of year	5,439,000	27,053,000
Supplemental disclosures of non-cash investing and financing cash flow information:
Unrealized gain (loss) on marketable investments	376,000	(928,000)
Conversion of Series B preferred	7,000	19,000
Operating lease liability arising from obtaining right of use asset	$ 73,000	$ 736,000