Palisade Bio (PALI) S-1 21 Jun 19 IPO registration Financial data

Document And Entity Information

Document And Entity Information	3 Months Ended
	Mar. 31, 2019
Document Information [Line Items]
Entity Registrant Name	Neuralstem, Inc.
Entity Central Index Key	0001357459
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Document Type	S-1
Document Period End Date	Mar. 31, 2019
Amendment Flag	false

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and cash equivalents	$ 4,005,089	$ 5,787,110	$ 9,724,248	$ 6,674,940	$ 15,194,949
Trade and other receivables	237,782	294,057		312,802
Current portion of related party receivable, net of discount		63,938		58,784
Prepaid expenses	295,406	363,288		402,273
Total current assets	4,538,277	6,508,393		12,448,799
Property and equipment, net	75,668	90,311		172,886
Patents, net	738,404	763,543		883,462
Related party receivable, net of discount and current portion		298,238		365,456
Other assets	53,354	23,965		13,853
Total assets	5,405,703	7,684,450		13,884,456
CURRENT LIABILITIES
Accounts payable and accrued expenses	1,083,143	832,564		875,065
Other current liabilities	126,930	218,602		220,879
Total current liabilities	1,210,073	1,051,166		1,514,569
Warrant liabilities, at fair value	923,849	583,734		3,852,882
Total liabilities	2,133,922	1,634,900		5,369,327
Commitments and contingencies (Note 5)
STOCKHOLDERS' EQUITY
Preferred stock, 7,000,000 shares authorized, $0.01 par value; 1,000,000 shares issued and outstanding at both March 31, 2019 and December 31, 2018	10,000	10,000		10,000
Common stock, $0.01 par value; 300,000,000 shares authorized, 18,205,060 shares issued and outstanding at both March 31, 2019 and December 31, 2018.	182,051	182,051		151,600
Additional paid-in capital	219,819,771	219,481,805		217,050,174
Accumulated other comprehensive income	(2,156)	(413)		2,631
Accumulated deficit	(216,737,885)	(213,623,893)		(208,699,276)
Total stockholders' equity	3,271,781	6,049,550	$ 6,607,111	8,515,129	$ 11,330,778
Total liabilities and stockholders' equity	$ 5,405,703	$ 7,684,450		$ 13,884,456

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	7,000,000	7,000,000	7,000,000
Preferred stock, shares issued (in shares)	1,000,000	1,000,000	1,000,000
Preferred stock, shares outstanding (in shares)	1,000,000	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000	300,000,000
Common stock, shares issued (in shares)	18,205,060	18,205,060	15,160,014
Common stock, shares outstanding (in shares)	18,205,060	18,205,060	15,160,014

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues	$ 2,500	$ 2,500
Operating expenses:
Research and development expenses	1,514,463	1,169,441
General and administrative expenses	944,602	1,182,054
Total operating expenses	2,459,065	2,351,495
Operating loss	(2,456,565)	(2,348,995)
Other income (expense):
Interest income	29,000	17,749
Interest expense	(2,017)	(1,920)
Change in fair value of derivative instruments	(340,115)	190,219
Other income (expense)	(344,295)	(4,021)
Total other income (expense)	(657,427)	202,027
Net loss	$ (3,113,992)	$ (2,146,968)
Net loss per share - basic and diluted (in dollars per share)	$ (0.17)	$ (0.14)
Weighted average common shares outstanding - basic (in shares)	18,216,421	15,116,937
Comprehensive loss:
Net loss	$ (3,113,992)	$ (2,146,968)
Foreign currency translation adjustment	(1,743)	115
Comprehensive loss	$ (3,115,735)	$ (2,146,853)

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Changes In Stockholders' Equity - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2016	1,000,000	11,032,858
Balance at Dec. 31, 2016	$ 10,000	$ 110,329	$ 204,239,837	$ 3,905	$ (193,033,293)	$ 11,330,778
Share based payments			1,769,964			1,769,964
Foreign currency translation adjustments				(1,274)		(1,274)
Net loss					(15,665,983)	(15,665,983)
Balance (in shares) at Dec. 31, 2017	1,000,000	15,160,014
Balance at Dec. 31, 2017	$ 10,000	$ 151,600	217,050,174	2,631	(208,699,276)	8,515,129
Share based payments			238,835			238,835
Foreign currency translation adjustments				115		115
Net loss					(2,146,968)	(2,146,968)
Balance (in shares) at Mar. 31, 2018	1,000,000	15,160,014
Balance at Mar. 31, 2018	$ 10,000	$ 151,600	217,289,009	2,746	(210,846,244)	6,607,111
Balance (in shares) at Dec. 31, 2017	1,000,000	15,160,014
Balance at Dec. 31, 2017	$ 10,000	$ 151,600	217,050,174	2,631	(208,699,276)	8,515,129
Share based payments			634,082			634,082
Foreign currency translation adjustments				(3,044)		(3,044)
Net loss					(4,924,617)	(4,924,617)
Balance (in shares) at Dec. 31, 2018	1,000,000	18,205,060
Balance at Dec. 31, 2018	$ 10,000	$ 182,051	219,481,805	(413)	(213,623,893)	6,049,550
Share based payments			337,966			337,966
Foreign currency translation adjustments				(1,743)		(1,743)
Net loss					(3,113,992)	(3,113,992)
Balance (in shares) at Mar. 31, 2019	1,000,000	18,205,060
Balance at Mar. 31, 2019	$ 10,000	$ 182,051	$ 219,819,771	$ (2,156)	$ (216,737,885)	$ 3,271,781

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (3,113,992)	$ (2,146,968)	$ (4,924,617)	$ (15,665,983)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	39,821	67,374	185,803	289,208
Share-based compensation expense	337,966	238,835	634,082	1,769,964
Change in fair value of liability classified warrants	340,115	(190,219)	(3,269,148)	1,470,174
Changes in operating assets and liabilities:
Trade and other receivables	56,275	175,430	18,745	(302,311)
Related party receivable	362,176	89,937	62,064	53,081
Prepaid expenses	75,938	56,241	32,303	297,298
Other assets	19,125	(4,000)	(3,991)	1,855
Accounts payable and accrued expenses	244,319	293,119	(36,991)	(1,522,917)
Accrued bonuses		(418,625)	(418,625)	(434,338)
Other current liabilities	(27,648)	(7,369)	11,490	(230,189)
Other long term liabilities		(704)	(1,876)	(16,333)
Net cash used in operating activities	(1,665,905)	(1,846,949)	(7,692,419)	(13,416,162)
Cash flows from investing activities:
Maturity of short-term investments		5,000,000	5,000,000	5,000,000
Net cash provided by investing activities		5,000,000	4,998,286	(94,046)
Cash flows from financing activities:
Payments of short-term notes payable	(117,019)	(104,244)	(363,345)	(326,533)
Net cash used in financing activities	(117,019)	(104,244)	1,814,233	4,990,778
Effects of exchange rates on cash	903	501	(7,930)	(579)
Net (decrease) increase in cash and cash equivalents	(1,782,021)	3,049,308	(887,830)	(8,520,009)
Cash and cash equivalents, beginning of period	5,787,110	6,674,940	6,674,940	15,194,949
Cash and cash equivalents, end of period	4,005,089	9,724,248	5,787,110	6,674,940
Supplemental disclosure of cash flows information:
Cash paid for interest	$ 2,017	$ 1,920	$ 7,698	$ 118,257

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 5,787,110	$ 6,674,940
Short-term investments		5,000,000
Trade and other receivables	294,057	312,802
Current portion of related party receivable, net of discount	63,938	58,784
Prepaid expenses	363,288	402,273
Total current assets	6,508,393	12,448,799
Property and equipment, net	90,311	172,886
Patents, net	763,543	883,462
Related party receivable, net of discount and current portion	298,238	365,456
Other assets	23,965	13,853
Total assets	7,684,450	13,884,456
CURRENT LIABILITIES
Accounts payable and accrued expenses	832,564	875,065
Accrued bonuses		418,625
Other current liabilities	218,602	220,879
Total current liabilities	1,051,166	1,514,569
Warrant liabilities, at fair value	583,734	3,852,882
Other long term liabilities		1,876
Total liabilities	1,634,900	5,369,327
Commitments and contingencies (Note 5)
STOCKHOLDERS' EQUITY
Preferred stock, 7,000,000 shares authorized, $0.01 par value; 1,000,000 shares issued and outstanding at both March 31, 2019 and December 31, 2018	10,000	10,000
Common stock, $0.01 par value; 300,000,000 shares authorized, 18,205,060 shares issued and outstanding at both March 31, 2019 and December 31, 2018.	182,051	151,600
Additional paid-in capital	219,481,805	217,050,174
Accumulated other comprehensive income	(413)	2,631
Accumulated deficit	(213,623,893)	(208,699,276)
Total stockholders' equity	6,049,550	8,515,129
Total liabilities and stockholders' equity	$ 7,684,450	$ 13,884,456

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	7,000,000	7,000,000	7,000,000
Preferred stock, shares issued (in shares)	1,000,000	1,000,000	1,000,000
Preferred stock, shares outstanding (in shares)	1,000,000	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000	300,000,000
Common stock, shares issued (in shares)	18,205,060	18,205,060	15,160,014
Common stock, shares outstanding (in shares)	18,205,060	18,205,060	15,160,014

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues	$ 260,000	$ 260,000
Operating expenses:
Research and development expenses	3,960,191	8,096,095
General and administrative expenses	4,559,265	5,471,010
Total operating expenses	8,519,456	13,567,105
Operating loss	(8,259,456)	(13,307,105)
Other income (expense):
Interest income	78,780	70,269
Interest expense	(7,698)	(159,066)
Gain (loss) from change in fair value of liability classified warrants	3,269,148	(1,470,174)
Fees related to issuance of liability classified warrants and other expenses	(5,391)	(799,907)
Total other income (expense)	3,334,839	(2,358,878)
Net loss	$ (4,924,617)	$ (15,665,983)
Net loss per share - basic and diluted (in dollars per share)	$ (0.32)	$ (1.20)
Weighted average common shares outstanding - basic (in shares)	15,156,925	13,064,422
Comprehensive loss:
Net loss	$ (4,924,617)	$ (15,665,983)
Foreign currency translation adjustment	(3,044)	(1,274)
Comprehensive loss	$ (4,927,661)	$ (15,667,257)

Consolidated Statements of Chan

Consolidated Statements of Changes In Stockholders' Equity - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2016	1,000,000	11,032,858
Balance at Dec. 31, 2016	$ 10,000	$ 110,329	$ 204,239,837	$ 3,905	$ (193,033,293)	$ 11,330,778
Share rounding adjustment relating to 1:13 reverse stock split (in shares)		6,537
Share rounding adjustment relating to 1:13 reverse stock split		$ 65	(65)
Share based payments			1,769,964			1,769,964
Issuance of common stock and inducement warrants for warrant exercises (in shares)		1,013,464
Issuance of common stock and inducement warrants for warrant exercises		$ 10,134	7,801,843			7,811,977
Issuance of common stock for RSU exercises (in shares)		4,939
Issuance of common stock for RSU exercises		$ 49	(49)
Issuance of common stock and warrants from capital raises, net (in shares)		3,022,387
Issuance of common stock and warrants from capital raises, net		$ 30,224	3,239,443			3,269,667
Issuance of restricted stock awards (in shares)		79,829
Issuance of restricted stock awards		$ 799	(799)
Foreign currency translation adjustments				(1,274)		(1,274)
Net loss					(15,665,983)	(15,665,983)
Balance (in shares) at Dec. 31, 2017	1,000,000	15,160,014
Balance at Dec. 31, 2017	$ 10,000	$ 151,600	217,050,174	2,631	(208,699,276)	8,515,129
Share based payments			238,835			238,835
Foreign currency translation adjustments				115		115
Net loss					(2,146,968)	(2,146,968)
Balance (in shares) at Mar. 31, 2018	1,000,000	15,160,014
Balance at Mar. 31, 2018	$ 10,000	$ 151,600	217,289,009	2,746	(210,846,244)	6,607,111
Balance (in shares) at Dec. 31, 2017	1,000,000	15,160,014
Balance at Dec. 31, 2017	$ 10,000	$ 151,600	217,050,174	2,631	(208,699,276)	8,515,129
Share based payments			634,082			634,082
Issuance of common stock and warrants from capital raises, net (in shares)		3,000,000
Issuance of common stock and warrants from capital raises, net		$ 30,000	1,798,000			1,828,000
Issuance of restricted stock awards (in shares)		45,046
Issuance of restricted stock awards		$ 451	(451)
Foreign currency translation adjustments				(3,044)		(3,044)
Net loss					(4,924,617)	(4,924,617)
Balance (in shares) at Dec. 31, 2018	1,000,000	18,205,060
Balance at Dec. 31, 2018	$ 10,000	$ 182,051	219,481,805	(413)	(213,623,893)	6,049,550
Share based payments			337,966			337,966
Foreign currency translation adjustments				(1,743)		(1,743)
Net loss					(3,113,992)	(3,113,992)
Balance (in shares) at Mar. 31, 2019	1,000,000	18,205,060
Balance at Mar. 31, 2019	$ 10,000	$ 182,051	$ 219,819,771	$ (2,156)	$ (216,737,885)	$ 3,271,781

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (4,924,617)	$ (15,665,983)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	185,803	289,208
Share-based compensation expense	634,082	1,769,964
Amortization of deferred financing fees and debt discount		59,781
Change in fair value of liability classified warrants	(3,269,148)	1,470,174
Warrant inducement expense		563,744
Expenses related to issuance of liability classified warrants		242,676
Loss on disposal of fixed assets and patent abandonment	18,342	8,128
Changes in operating assets and liabilities:
Trade and other receivables	18,745	(302,311)
Related party receivable	62,064	53,081
Prepaid expenses	32,303	297,298
Other assets	(3,991)	1,855
Accounts payable and accrued expenses	(36,991)	(1,522,917)
Accrued bonuses	(418,625)	(434,338)
Other current liabilities	11,490	(230,189)
Other long term liabilities	(1,876)	(16,333)
Net cash used in operating activities	(7,692,419)	(13,416,162)
Cash flows from investing activities:
Purchases of short-term investments		(5,000,000)
Maturity of short-term investments	5,000,000	5,000,000
Patent costs		(82,645)
Purchase of property and equipment	(1,714)	(11,401)
Net cash provided by (used in) investing activities	4,998,286	(94,046)
Cash flows from financing activities:
Proceeds from issuance of common stock from warrants exercised, net of issuance costs		3,225,176
Proceeds from sale of common stock, preferred stock and warrants, net of issuance costs	1,828,000	5,510,840
Payments of long-term debt		(3,765,568)
Proceeds from short term notes payable	349,578	346,863
Payments of short-term notes payable	(363,345)	(326,533)
Net cash provided by financing activities	1,814,233	4,990,778
Effects of exchange rates on cash	(7,930)	(579)
Net decrease in cash and cash equivalents	(887,830)	(8,520,009)
Cash and cash equivalents, beginning of period	6,674,940	15,194,949
Cash and cash equivalents, end of period	5,787,110	6,674,940
Supplemental disclosure of cash flows information:
Cash paid for interest	$ 7,698	$ 118,257

Note 1 - Organization, Business

Note 1 - Organization, Business and Financial Condition	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1. Organization, Business and Financial Condition Nature of business Neuralstem, Inc. and its subsidiary are referred to as “Neuralstem,” the “Company,” “us,” or “we” throughout this report. The operations of our wholly-owned and controlled subsidiary located in the People’s Republic of China are consolidated in our unaudited condensed consolidated financial statements and all intercompany activity has been eliminated. The Company operates in one Neuralstem is a clinical stage biopharmaceutical company that is utilizing its proprietary human neural stem cell technology to create a comprehensive platform of therapies for the treatment of central nervous system diseases. The Company has utilized this technology as a tool for small-molecule drug discovery and to create cell therapy biotherapeutics to treat central nervous system diseases. The Company was founded in 1997 Liquidity and Going Concern The Company has incurred losses since its inception and has not not no one not In making this assessment the Company performed a comprehensive analysis of its current circumstances including: its financial position at March 31, 2019, one We expect that our existing cash and cash equivalents will be sufficient to enable us to fund our anticipated level of operations based on our current operating plans into the third 2019. no not may third not We have spent and will continue to spend substantial funds in the research, development, pre-clinical and clinical testing of our small molecule and stem cell product candidates with the goal of ultimately obtaining approval from the United States Food and Drug Administration (the “FDA”) and its international equivalents regulatory agencies, to market and sell our products. We have also begun spending funds on the evaluation and new assets and technologies with the goal of acquisition and development. No	Note 1. Organization and Business and Financial Condition Nature of business Neuralstem, Inc. and its subsidiary are referred to as “Neuralstem,” the “Company,” “us,” or “we” throughout this report. The operations of our wholly-owned and controlled subsidiary located in the People’s Republic of China are consolidated in our condensed consolidated financial statements and all intercompany activity has been eliminated. The Company operates in one Neuralstem is a clinical stage biopharmaceutical company that is utilizing its proprietary human neural stem cell technology to create a comprehensive platform of therapies for the treatment of central nervous system diseases. The Company has utilized this technology as a tool for small-molecule drug discovery and to create cell therapy biotherapeutics to treat central nervous system diseases. The Company was founded in 1997 Liquidity and Going Concern The Company has incurred losses since its inception and has not not no one not In making this assessment the Company performed a comprehensive analysis of its current circumstances including: its financial position at December 31, 2018, one We expect that our existing cash and cash equivalents will be sufficient to enable us to fund our anticipated level of operations based on our current operating plans into the third 2019. no not may third not We have spent and will continue to spend substantial funds in the research, development, pre-clinical and clinical testing of our small molecule and stem cell product candidates with the goal of ultimately obtaining approval from the United States Food and Drug Administration (the “FDA”) and its international equivalents regulatory agencies, to market and sell our products. We have also begun spending funds on the evaluation and new assets and technologies with the goal of acquisition and development. No

Note 2 - Significant Accounting

Note 2 - Significant Accounting Policies and Basis of Presentation	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Basis of Presentation In management’s opinion, the accompanying interim unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments, which are necessary to present fairly our financial position, results of operations and cash flows. The unaudited condensed consolidated balance sheet at December 31, 2018, not may not 10 December 31, 2018, may Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The unaudited condensed consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates. Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3 Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss. Cash, Cash Equivalents and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents. Our investment policy, approved by our Board of Directors, limits the amount we may one not Revenue The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers; (ii) identification of distinct performance obligations in the contract; (iii) determination of contract transaction price; (iv) allocation of contract transaction price to the performance obligations; and (v) determination of revenue recognition based on timing of satisfaction of the performance obligation. The Company recognizes revenues upon the satisfaction of its performance obligation (upon transfer of control of promised goods or services to customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those goods or services. Deferred revenue results from cash receipts from or amounts billed to customers in advance of the transfer of control of the promised services to the customer and is recognized as performance obligations are satisfied. When sales commissions or other costs to obtain contracts with customers are considered incremental and recoverable, those costs are deferred and then amortized as selling and marketing expenses on a straight-line basis over an estimated period of benefit. Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the three March 31, 2019 2018, $95,000 $84,000, Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the three March 31, 2019 2018. 13.5 9.5 three March 31, 2019 2018, Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants is generally determined at the grant date using an option pricing model that uses Level 3 Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No three March 31, 2019 2018. Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not” Leases We determine if an arrangement is or contains a lease at its inception. We have made accounting policy elections whereby we (i) do not 12 not ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Rent expense is recognized on a straight-line basis over the lease term. We currently have one 12 August 2019 $49,600 March 31, 2019. $29,800 three March 31, 2019. not 12.75% March 31, 2019, $33,900 $48,100, We also have two not $47,300 $47,100 March 31, 2019 2018, 2019 $16,900 In addition, in April 2018, $62,200 $24,200 March 31, 2019. Significant New Accounting Pronouncements Recently Adopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 may January 1, 2019 not not $53,000 $75,700 In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. January 1, 2019. not Unadopted Guidance In June 2016, ASU No. 2016 13, December 15, 2019, not In August 2018, ASU 2018 13, 820 December 15, 2019 In August 2018, ASU 2018 15, December 15, 2019 We have reviewed other recent accounting pronouncements and concluded that they are either not no	Note 2. Basis of Presentation Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The financial statements include the accounts of the Company and our wholly owned subsidiary. All significant intercompany transactions and balances have been eliminated. Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates. Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3 Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss. Cash, Cash Equivalents, Short-Term Investments and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Short-term investments consist entirely of fixed income certificates of deposit (“CDs”) with original maturities of greater than 90 not one Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and short-term investments. Our investment policy, approved by our Board of Directors, limits the amount we may one not Revenue On January 1, 2018, 606, not January 1, 2018. Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the years ended December 31, 2018 2017, $538,000 $41,000, Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the years ended December 31, 2018 2017. 12.6 10.2 December 31, 2018 2017, Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants granted to employees and board members is generally determined at the grant date while awards granted to non-employee consultants are generally valued at the vesting date using an option pricing model that uses Level 3 Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No December 31, 2018 2017. Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not” Corporate tax rate changes resulting from the impacts of the Tax Cuts and Jobs Act of 2017 December 31, 2018 2017. Significant New Accounting Pronouncements Recently Adopted Guidance In May 2014, Accounting Standard Update (“ASU”), No. 2014 09, December 15, 2017. may January 1, 2018 not In May 2017, ASU No. 2017 09, December 15, 2017 January 1, 2018 not In July 2017, ASU No. 2017 11, no December 15, 2018 January 1, 2018, not Unadopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 not $50,000 $75,000 In June 2016, ASU No. 2016 13, December 15, 2019, December 15, 2018, not In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. not In August 2018, ASU 2018 13, 820 December 15, 2019. In August 2018, ASU 2018 15, December 15, 2019. We have reviewed other recent accounting pronouncements and concluded that they are either not no

Note 3 - Fair Value Measurement

Note 3 - Fair Value Measurements	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	Note 3. Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These levels are: · Level 1 · Level 2 not · Level 3 Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis We have segregated our financial assets and liabilities that are measured at fair value on a recurring into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date. At March 31, 2019 December 31, 2018, May 2016 August 2017 4 3 Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 Liability classified stock purchase warrants $ - $ - $ 923,849 $ 923,849 Balance at March 31, 2019 $ - $ - $ 923,849 $ 923,849 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 three March 31, 2019: Mark-to-market Balance at December 31, 2018 $ 583,734 Change in fair value - loss 340,115 Balance at March 31, 2019 $ 923,849 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 three March 31, 2018: Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (190,219 ) Balance at March 31, 2018 $ 3,662,663 The (gains) losses resulting from the changes in the fair value of the liability classified warrants are classified as other income or expense in the accompanying unaudited condensed consolidated statements of operations. The fair value of the common stock purchase warrants is determined based on the Black-Scholes option pricing model or other option pricing models as appropriate and includes the use of unobservable inputs such as the expected term, anticipated volatility and expected dividends. Changes in any of the assumptions related to the unobservable inputs identified above may	Note 3. Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These levels are: • Level 1 • Level 2 not • Level 3 Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis We have segregated our financial assets and liabilities that are measured at fair value on a recurring into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date. At December 31, 2018 December 31, 2017, May 2016 August 2017 4 3 Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 3,852,882 $ 3,852,882 Balance at December 31, 2017 $ - $ - $ 3,852,882 $ 3,852,882 Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 December 31, 2018: Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (3,269,148 ) Balance at December 31, 2018 $ 583,734 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 December 31, 2017: Mark-to-market Balance at December 31, 2016 $ 3,921,917 Issuance of warrants 2,483,848 Exercise of warrants (4,023,057 ) Change in fair value - loss 1,470,174 Balance at December 31, 2017 $ 3,852,882 The (gains) losses resulting from the changes in the fair value of the liability classified warrants are classified as other income or expense in the accompanying consolidated statements of operations. The fair value of the common stock purchase warrants is determined based on the Black-Scholes option pricing model or other option pricing models as appropriate and includes the use of unobservable inputs such as the expected term, anticipated volatility and expected dividends. Changes in any of the assumptions related to the unobservable inputs identified above may

Note 4 - Stockholders' Equity

Note 4 - Stockholders' Equity	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	Note 4. We have granted share-based compensation awards to employees, board members and service providers. Awards may ten March 31, 2019, 10.9 We typically record share-based compensation expense on a straight-line basis over the requisite service period. Share-based compensation expenses included in the statements of operations are as follows: Three Months Ended March 31 2019 2018 Research and development expenses $ 200,337 $ 64,583 General and administrative expenses 137,629 174,252 Total $ 337,966 $ 238,835 Stock Options A summary of stock option activity and related information for the three March 31, 2019 Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,632,662 $ 10.78 5.1 $ - Granted 800,000 $ 0.43 Exercised - $ - $ - Forfeited - $ - Outstanding at March 31 2019 2,432,662 $ 7.37 6.4 $ 19,040 Exercisable at March 31, 2019 1,795,786 $ 9.78 5.3 $ 5,712 Range of Exercise Prices Number of Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value $0.40 - $0.50 800,000 $ 0.43 9.7 $ 19,040 $1.00 - $3.50 588,640 $ 1.15 7.1 - $3.51 - $13.00 532,236 $ 9.76 4.1 - $13.01 - $26.00 343,782 $ 14.79 2.8 - $26.01 - $39.00 65,504 $ 30.85 2.2 - $39.01 - $56.00 102,500 $ 45.03 4.3 - 2,432,662 $ 7.37 6.4 $ 19,040 The Company uses the Black-Scholes option pricing model for “plain vanilla” options and other pricing models as appropriate to calculate the fair value of options. The Company generally uses the “simplified method” to estimate expected life. Significant assumptions used in these models include: Three Months Ended March 31, 2019 Annual dividend - Expected life (in years) 5.4 - 5.5 Risk free interest rate 2.4% - 2.5% Expected volatility 97% Options granted in the three March 31, 2019, $0.34 no three March 31, 2018. Unrecognized compensation cost for unvested stock option awards outstanding at March 31, 2019 $250,000 0.8 In the three March 31, 2019, $102,000 three March 31, 2019. RSUs We have granted restricted stock units (RSUs) to certain employees and board members that entitle the holders to receive shares of our common stock upon vesting and subject to certain restrictions regarding the exercise of the RSUs. The grant date fair value of RSUs is based upon the market price of the underlying common stock on the date of grant. No three March 31, 2019 2018. No three March 31, 2019. At March 31, 2019, 33,758 $4.66 $15,200. No three March 31, 2019. March 31, 2019. Restricted Stock We have granted restricted stock to certain board members that vest quarterly over the grant year. The grant date fair value of the restricted stock is based upon the market price of the common stock on the date of grant. No three March 31, 2019 2018. Restricted stock vesting in the three March 31, 2019, $1.11 $5,100. At March 31, 2019, 11,262 $1.11. March 31, 2019 $12,500 0.25 Stock Purchase Warrants. We have issued warrants to purchase common stock to certain officers, directors, stockholders and service providers as well as in conjunction with debt and equity offerings and at various times replacement warrants were issued as an inducement for warrant exercises. In May 2016 August 2017, 1,746,173 2,250,000 contained in the warrants. At March 31, 2019, 2,982,709 3 In the three March 31, 2019, 500,000 third $0.30, January 2024 $0.19 25% 75% March 31, 2019. no 2.5 2.5% 110%. A summary of outstanding warrants at March 31, 2019 Range of Exercise Prices Number of Warrants Outstanding Range of Expiration Dates $0.30 - $0.875 6,662,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 44,233 December 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $52.31 11,539 July 2019 7,203,494 Preferred and Common Stock We have outstanding 1,000,000 4.5% December 2016. 4.5% 3,887,387 April 2019, 465,191 4.5% 1,808,377	Note 4. We have granted share-based compensation awards to employees, board members and service providers. In addition, we have issued warrants to purchase common stock in conjunction with debt and equity offerings. Awards may ten December 31, 2018, 10.8 We record share-based compensation expense on a straight-line basis over the requisite service period. Share-based compensation expense included in the statements of operations was as follows: Year Ended December 31, 2018 2017 Research and development costs $ 133,334 $ 1,091,036 General and administrative expenses 500,748 678,928 Total $ 634,082 $ 1,769,964 Stock Options A summary of stock option activity and related information for the year ended December 31, 2018 Number of Options Weighted- Weighted- Aggregate Outstanding at January 1, 2018 1,894,077 $ 19.76 4.7 $ 108,000 Granted 488,640 $ 1.13 $ - Exercised - - Forfeited/Expired (750,055 ) $ 27.19 Outstanding at December 31, 2018 1,632,662 $ 10.78 5.1 $ - Exercisable at December 31, 2018 1,166,127 $ 14.59 4.4 $ - Range of Exercise Prices Number of Options Weighted- Weighted- Aggregate $1.00 - $3.50 588,640 $ 1.15 7.3 $ - $3.51 - $13.00 532,236 $ 9.76 4.3 - $13.01 - $26.00 343,782 $ 14.79 3.1 - $26.01 - $39.00 65,504 $ 30.85 2.5 - $39.01 - $56.00 102,500 $ 45.03 4.6 - 1,632,662 $ 10.78 5.1 $ - The Company uses the Black-Scholes option pricing model for “plain vanilla” options and other pricing models as appropriate to calculate the fair value of options. Significant assumptions used in these models include: Year Ended December 31, 2018 2017 Annual dividend - - Expected life (in years) 2.5 - 5.3 0.3 - 6.5 Risk free interest rate 2.5% - 2.8% 0.80% - 2.22% Expected volatility 97% - 113% 62.2% - 98.0% Options granted in the years ended December 31, 2018 2017 $0.47 $1.34, December 31, 2018 2017 $205,000 $302,000, Unrecognized compensation cost for unvested stock option awards outstanding at December 31, 2018 $179,000 1.9 On December 12, 2018, 800,000 $0.425 ten 200,000 200,000 two 400,000 January 1, 2019 not RSUs We have granted restricted stock units (RSU’s) that entitle the holders to receive shares of our common stock upon vesting and subject to certain restrictions regarding the exercise of the RSU’s and the holders’ ability to transfer the shares received upon exercise. The fair value of RSU’s granted is based upon the market price of the underlying common stock as if they were vested and issued on the date of grant. A summary of our RSU activity for the year ended December 31, 2018 Number of Weighted- Outstanding at January 1, 2018 11,235 $ 11.77 Granted 45,046 $ 1.11 Exercised and converted to common shares - $ - Forfeited - $ - Outstanding at December 31, 2018 56,281 $ 3.24 Exercisable at December 31, 2018 33,759 $ 4.66 The total intrinsic value of the outstanding RSU’s at December 31, 2018 $17,000. December 31, 2018 2017, $50,000 $25,000, December 31, 2017 $23,000. No December 31, 2018. Unrecognized compensation cost for unvested RSU’s outstanding at December 31, 2018 $25,000 0.5 Restricted Stock We have granted restricted stock to certain board members. A summary of our restricted stock activity for the year ended December 31, 2018 Shares of Weighted- Outstanding at January 1, 2018 49,960 $ 3.00 Granted 45,046 $ 1.11 Vested (72,483 ) $ 2.41 Forfeited - $ - Outstanding at December 31, 2018 22,523 $ 1.11 The total intrinsic value of the outstanding restricted stock at December 31, 2018 $7,000. December 31, 2018 $84,000. Unrecognized compensation cost for unvested restricted stock outstanding at December 31, 2018 $25,000 0.5 Stock Purchase Warrants We have issued warrants to purchase common stock to certain officers, directors, stockholders and service providers as well as in conjunction with debt and equity offerings and at various times replacement warrants were issued as an inducement for warrant exercises. In May 2016 August 2017, 1,746,173 2,250,000 contained in the warrants. At December 31, 2018, 2,982,709 3 October 2018 2,982,709 $2.00 $0.57 In October 2018, 3,000,000 180,000 $0.75 $0.875, A summary of outstanding warrants at December 31, 2018 Range of Exercise Number of Range of Expiration Dates $0.57 - $0.875 6,162,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 153,755 March 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $47.30 - $52.20 275,897 January 2019 - July 2019 7,077,374 Preferred and Common Stock We have outstanding 1,000,000 4.5% December 2016. 4.5% 3,887,387 In October 2018, 3,000,000 3,000,000 $0.70 $2.1 $0.75 six five one June 23, 2017 ( No. 333 218608 180,000 $0.875 5

Note 5 - Commitments and Contin

Note 5 - Commitments and Contingencies	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 5. We currently operate one one 1,500 $5,700 December 31, 2018. In 2015, 3,100 $13,000 August 31, 2019. April 2018, $62,200 March 31, 2019. We also lease a research facility in People’s Republic of China. This lease expires on September 30, 2019 $3,800 From time to time, we are parties to legal proceedings that we believe to be ordinary, routine litigation incidental to the business. We are currently not	Note 8. We currently operate one one 1,500 $5,700 December 31, 2018. In 2015, 3,100 $12,000 August 31, 2019. May 2017, $92,000 April 2018, $50,000 $87,000 December 31, 2018. We also lease a research facility in People’s Republic of China. This lease expires on March 31, 2019 $3,800 Future minimum payments under all leases at December 31, 2018 Year Amount 2019 115,000 2020 - 2021 - 2022 - 2023 and thereafter - Total minimum payments $ 115,000 The Company recognized approximately $164,000 $161,000, December 31, 2018 2017, From time to time, we are parties to legal proceedings that we believe to be ordinary, routine litigation incidental to the business. We are currently not The Company is currently obligated under a written employment agreement with our Chief Scientific Officer (“CSO”). Pursuant to the terms of the agreement, our CSO receives annual salary of $500,000.

Note 6 - Related Party Receivab

Note 6 - Related Party Receivable	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	Note 6. On August 10, 2016, six $658,000 The $658,000 $199,000 In March 2019, 50% March 31, 2019, $229,000 July 2025. not	Note 9. On August 10, 2016, six $658,000 The $658,000 $199,000 $458,000 December 31, 2018 $100,000 July 2022. In March 2019,

Note 7 - Subsequent Events

Note 7 - Subsequent Events	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Subsequent Events [Text Block]	Note 7. None.	Note 10. None

Note 1 - Organization, Busine_2

Note 1 - Organization, Business and Financial Condition	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1. Organization, Business and Financial Condition Nature of business Neuralstem, Inc. and its subsidiary are referred to as “Neuralstem,” the “Company,” “us,” or “we” throughout this report. The operations of our wholly-owned and controlled subsidiary located in the People’s Republic of China are consolidated in our unaudited condensed consolidated financial statements and all intercompany activity has been eliminated. The Company operates in one Neuralstem is a clinical stage biopharmaceutical company that is utilizing its proprietary human neural stem cell technology to create a comprehensive platform of therapies for the treatment of central nervous system diseases. The Company has utilized this technology as a tool for small-molecule drug discovery and to create cell therapy biotherapeutics to treat central nervous system diseases. The Company was founded in 1997 Liquidity and Going Concern The Company has incurred losses since its inception and has not not no one not In making this assessment the Company performed a comprehensive analysis of its current circumstances including: its financial position at March 31, 2019, one We expect that our existing cash and cash equivalents will be sufficient to enable us to fund our anticipated level of operations based on our current operating plans into the third 2019. no not may third not We have spent and will continue to spend substantial funds in the research, development, pre-clinical and clinical testing of our small molecule and stem cell product candidates with the goal of ultimately obtaining approval from the United States Food and Drug Administration (the “FDA”) and its international equivalents regulatory agencies, to market and sell our products. We have also begun spending funds on the evaluation and new assets and technologies with the goal of acquisition and development. No	Note 1. Organization and Business and Financial Condition Nature of business Neuralstem, Inc. and its subsidiary are referred to as “Neuralstem,” the “Company,” “us,” or “we” throughout this report. The operations of our wholly-owned and controlled subsidiary located in the People’s Republic of China are consolidated in our condensed consolidated financial statements and all intercompany activity has been eliminated. The Company operates in one Neuralstem is a clinical stage biopharmaceutical company that is utilizing its proprietary human neural stem cell technology to create a comprehensive platform of therapies for the treatment of central nervous system diseases. The Company has utilized this technology as a tool for small-molecule drug discovery and to create cell therapy biotherapeutics to treat central nervous system diseases. The Company was founded in 1997 Liquidity and Going Concern The Company has incurred losses since its inception and has not not no one not In making this assessment the Company performed a comprehensive analysis of its current circumstances including: its financial position at December 31, 2018, one We expect that our existing cash and cash equivalents will be sufficient to enable us to fund our anticipated level of operations based on our current operating plans into the third 2019. no not may third not We have spent and will continue to spend substantial funds in the research, development, pre-clinical and clinical testing of our small molecule and stem cell product candidates with the goal of ultimately obtaining approval from the United States Food and Drug Administration (the “FDA”) and its international equivalents regulatory agencies, to market and sell our products. We have also begun spending funds on the evaluation and new assets and technologies with the goal of acquisition and development. No

Note 2 - Significant Accounti_2

Note 2 - Significant Accounting Policies and Basis of Presentation	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Basis of Presentation In management’s opinion, the accompanying interim unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments, which are necessary to present fairly our financial position, results of operations and cash flows. The unaudited condensed consolidated balance sheet at December 31, 2018, not may not 10 December 31, 2018, may Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The unaudited condensed consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates. Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3 Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss. Cash, Cash Equivalents and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents. Our investment policy, approved by our Board of Directors, limits the amount we may one not Revenue The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers; (ii) identification of distinct performance obligations in the contract; (iii) determination of contract transaction price; (iv) allocation of contract transaction price to the performance obligations; and (v) determination of revenue recognition based on timing of satisfaction of the performance obligation. The Company recognizes revenues upon the satisfaction of its performance obligation (upon transfer of control of promised goods or services to customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those goods or services. Deferred revenue results from cash receipts from or amounts billed to customers in advance of the transfer of control of the promised services to the customer and is recognized as performance obligations are satisfied. When sales commissions or other costs to obtain contracts with customers are considered incremental and recoverable, those costs are deferred and then amortized as selling and marketing expenses on a straight-line basis over an estimated period of benefit. Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the three March 31, 2019 2018, $95,000 $84,000, Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the three March 31, 2019 2018. 13.5 9.5 three March 31, 2019 2018, Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants is generally determined at the grant date using an option pricing model that uses Level 3 Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No three March 31, 2019 2018. Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not” Leases We determine if an arrangement is or contains a lease at its inception. We have made accounting policy elections whereby we (i) do not 12 not ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Rent expense is recognized on a straight-line basis over the lease term. We currently have one 12 August 2019 $49,600 March 31, 2019. $29,800 three March 31, 2019. not 12.75% March 31, 2019, $33,900 $48,100, We also have two not $47,300 $47,100 March 31, 2019 2018, 2019 $16,900 In addition, in April 2018, $62,200 $24,200 March 31, 2019. Significant New Accounting Pronouncements Recently Adopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 may January 1, 2019 not not $53,000 $75,700 In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. January 1, 2019. not Unadopted Guidance In June 2016, ASU No. 2016 13, December 15, 2019, not In August 2018, ASU 2018 13, 820 December 15, 2019 In August 2018, ASU 2018 15, December 15, 2019 We have reviewed other recent accounting pronouncements and concluded that they are either not no	Note 2. Basis of Presentation Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The financial statements include the accounts of the Company and our wholly owned subsidiary. All significant intercompany transactions and balances have been eliminated. Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates. Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3 Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss. Cash, Cash Equivalents, Short-Term Investments and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Short-term investments consist entirely of fixed income certificates of deposit (“CDs”) with original maturities of greater than 90 not one Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and short-term investments. Our investment policy, approved by our Board of Directors, limits the amount we may one not Revenue On January 1, 2018, 606, not January 1, 2018. Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the years ended December 31, 2018 2017, $538,000 $41,000, Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the years ended December 31, 2018 2017. 12.6 10.2 December 31, 2018 2017, Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants granted to employees and board members is generally determined at the grant date while awards granted to non-employee consultants are generally valued at the vesting date using an option pricing model that uses Level 3 Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No December 31, 2018 2017. Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not” Corporate tax rate changes resulting from the impacts of the Tax Cuts and Jobs Act of 2017 December 31, 2018 2017. Significant New Accounting Pronouncements Recently Adopted Guidance In May 2014, Accounting Standard Update (“ASU”), No. 2014 09, December 15, 2017. may January 1, 2018 not In May 2017, ASU No. 2017 09, December 15, 2017 January 1, 2018 not In July 2017, ASU No. 2017 11, no December 15, 2018 January 1, 2018, not Unadopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 not $50,000 $75,000 In June 2016, ASU No. 2016 13, December 15, 2019, December 15, 2018, not In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. not In August 2018, ASU 2018 13, 820 December 15, 2019. In August 2018, ASU 2018 15, December 15, 2019. We have reviewed other recent accounting pronouncements and concluded that they are either not no

Note 3 - Fair Value Measureme_2

Note 3 - Fair Value Measurement	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	Note 3. Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These levels are: · Level 1 · Level 2 not · Level 3 Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis We have segregated our financial assets and liabilities that are measured at fair value on a recurring into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date. At March 31, 2019 December 31, 2018, May 2016 August 2017 4 3 Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 Liability classified stock purchase warrants $ - $ - $ 923,849 $ 923,849 Balance at March 31, 2019 $ - $ - $ 923,849 $ 923,849 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 three March 31, 2019: Mark-to-market Balance at December 31, 2018 $ 583,734 Change in fair value - loss 340,115 Balance at March 31, 2019 $ 923,849 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 three March 31, 2018: Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (190,219 ) Balance at March 31, 2018 $ 3,662,663 The (gains) losses resulting from the changes in the fair value of the liability classified warrants are classified as other income or expense in the accompanying unaudited condensed consolidated statements of operations. The fair value of the common stock purchase warrants is determined based on the Black-Scholes option pricing model or other option pricing models as appropriate and includes the use of unobservable inputs such as the expected term, anticipated volatility and expected dividends. Changes in any of the assumptions related to the unobservable inputs identified above may	Note 3. Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These levels are: • Level 1 • Level 2 not • Level 3 Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis We have segregated our financial assets and liabilities that are measured at fair value on a recurring into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date. At December 31, 2018 December 31, 2017, May 2016 August 2017 4 3 Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 3,852,882 $ 3,852,882 Balance at December 31, 2017 $ - $ - $ 3,852,882 $ 3,852,882 Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 December 31, 2018: Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (3,269,148 ) Balance at December 31, 2018 $ 583,734 The following table presents the activity for those items measured at fair value on a recurring basis using Level 3 December 31, 2017: Mark-to-market Balance at December 31, 2016 $ 3,921,917 Issuance of warrants 2,483,848 Exercise of warrants (4,023,057 ) Change in fair value - loss 1,470,174 Balance at December 31, 2017 $ 3,852,882 The (gains) losses resulting from the changes in the fair value of the liability classified warrants are classified as other income or expense in the accompanying consolidated statements of operations. The fair value of the common stock purchase warrants is determined based on the Black-Scholes option pricing model or other option pricing models as appropriate and includes the use of unobservable inputs such as the expected term, anticipated volatility and expected dividends. Changes in any of the assumptions related to the unobservable inputs identified above may

Note 4 - Stockholders' Equity 1

Note 4 - Stockholders' Equity 10K	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	Note 4. We have granted share-based compensation awards to employees, board members and service providers. Awards may ten March 31, 2019, 10.9 We typically record share-based compensation expense on a straight-line basis over the requisite service period. Share-based compensation expenses included in the statements of operations are as follows: Three Months Ended March 31 2019 2018 Research and development expenses $ 200,337 $ 64,583 General and administrative expenses 137,629 174,252 Total $ 337,966 $ 238,835 Stock Options A summary of stock option activity and related information for the three March 31, 2019 Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,632,662 $ 10.78 5.1 $ - Granted 800,000 $ 0.43 Exercised - $ - $ - Forfeited - $ - Outstanding at March 31 2019 2,432,662 $ 7.37 6.4 $ 19,040 Exercisable at March 31, 2019 1,795,786 $ 9.78 5.3 $ 5,712 Range of Exercise Prices Number of Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value $0.40 - $0.50 800,000 $ 0.43 9.7 $ 19,040 $1.00 - $3.50 588,640 $ 1.15 7.1 - $3.51 - $13.00 532,236 $ 9.76 4.1 - $13.01 - $26.00 343,782 $ 14.79 2.8 - $26.01 - $39.00 65,504 $ 30.85 2.2 - $39.01 - $56.00 102,500 $ 45.03 4.3 - 2,432,662 $ 7.37 6.4 $ 19,040 The Company uses the Black-Scholes option pricing model for “plain vanilla” options and other pricing models as appropriate to calculate the fair value of options. The Company generally uses the “simplified method” to estimate expected life. Significant assumptions used in these models include: Three Months Ended March 31, 2019 Annual dividend - Expected life (in years) 5.4 - 5.5 Risk free interest rate 2.4% - 2.5% Expected volatility 97% Options granted in the three March 31, 2019, $0.34 no three March 31, 2018. Unrecognized compensation cost for unvested stock option awards outstanding at March 31, 2019 $250,000 0.8 In the three March 31, 2019, $102,000 three March 31, 2019. RSUs We have granted restricted stock units (RSUs) to certain employees and board members that entitle the holders to receive shares of our common stock upon vesting and subject to certain restrictions regarding the exercise of the RSUs. The grant date fair value of RSUs is based upon the market price of the underlying common stock on the date of grant. No three March 31, 2019 2018. No three March 31, 2019. At March 31, 2019, 33,758 $4.66 $15,200. No three March 31, 2019. March 31, 2019. Restricted Stock We have granted restricted stock to certain board members that vest quarterly over the grant year. The grant date fair value of the restricted stock is based upon the market price of the common stock on the date of grant. No three March 31, 2019 2018. Restricted stock vesting in the three March 31, 2019, $1.11 $5,100. At March 31, 2019, 11,262 $1.11. March 31, 2019 $12,500 0.25 Stock Purchase Warrants. We have issued warrants to purchase common stock to certain officers, directors, stockholders and service providers as well as in conjunction with debt and equity offerings and at various times replacement warrants were issued as an inducement for warrant exercises. In May 2016 August 2017, 1,746,173 2,250,000 contained in the warrants. At March 31, 2019, 2,982,709 3 In the three March 31, 2019, 500,000 third $0.30, January 2024 $0.19 25% 75% March 31, 2019. no 2.5 2.5% 110%. A summary of outstanding warrants at March 31, 2019 Range of Exercise Prices Number of Warrants Outstanding Range of Expiration Dates $0.30 - $0.875 6,662,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 44,233 December 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $52.31 11,539 July 2019 7,203,494 Preferred and Common Stock We have outstanding 1,000,000 4.5% December 2016. 4.5% 3,887,387 April 2019, 465,191 4.5% 1,808,377	Note 4. We have granted share-based compensation awards to employees, board members and service providers. In addition, we have issued warrants to purchase common stock in conjunction with debt and equity offerings. Awards may ten December 31, 2018, 10.8 We record share-based compensation expense on a straight-line basis over the requisite service period. Share-based compensation expense included in the statements of operations was as follows: Year Ended December 31, 2018 2017 Research and development costs $ 133,334 $ 1,091,036 General and administrative expenses 500,748 678,928 Total $ 634,082 $ 1,769,964 Stock Options A summary of stock option activity and related information for the year ended December 31, 2018 Number of Options Weighted- Weighted- Aggregate Outstanding at January 1, 2018 1,894,077 $ 19.76 4.7 $ 108,000 Granted 488,640 $ 1.13 $ - Exercised - - Forfeited/Expired (750,055 ) $ 27.19 Outstanding at December 31, 2018 1,632,662 $ 10.78 5.1 $ - Exercisable at December 31, 2018 1,166,127 $ 14.59 4.4 $ - Range of Exercise Prices Number of Options Weighted- Weighted- Aggregate $1.00 - $3.50 588,640 $ 1.15 7.3 $ - $3.51 - $13.00 532,236 $ 9.76 4.3 - $13.01 - $26.00 343,782 $ 14.79 3.1 - $26.01 - $39.00 65,504 $ 30.85 2.5 - $39.01 - $56.00 102,500 $ 45.03 4.6 - 1,632,662 $ 10.78 5.1 $ - The Company uses the Black-Scholes option pricing model for “plain vanilla” options and other pricing models as appropriate to calculate the fair value of options. Significant assumptions used in these models include: Year Ended December 31, 2018 2017 Annual dividend - - Expected life (in years) 2.5 - 5.3 0.3 - 6.5 Risk free interest rate 2.5% - 2.8% 0.80% - 2.22% Expected volatility 97% - 113% 62.2% - 98.0% Options granted in the years ended December 31, 2018 2017 $0.47 $1.34, December 31, 2018 2017 $205,000 $302,000, Unrecognized compensation cost for unvested stock option awards outstanding at December 31, 2018 $179,000 1.9 On December 12, 2018, 800,000 $0.425 ten 200,000 200,000 two 400,000 January 1, 2019 not RSUs We have granted restricted stock units (RSU’s) that entitle the holders to receive shares of our common stock upon vesting and subject to certain restrictions regarding the exercise of the RSU’s and the holders’ ability to transfer the shares received upon exercise. The fair value of RSU’s granted is based upon the market price of the underlying common stock as if they were vested and issued on the date of grant. A summary of our RSU activity for the year ended December 31, 2018 Number of Weighted- Outstanding at January 1, 2018 11,235 $ 11.77 Granted 45,046 $ 1.11 Exercised and converted to common shares - $ - Forfeited - $ - Outstanding at December 31, 2018 56,281 $ 3.24 Exercisable at December 31, 2018 33,759 $ 4.66 The total intrinsic value of the outstanding RSU’s at December 31, 2018 $17,000. December 31, 2018 2017, $50,000 $25,000, December 31, 2017 $23,000. No December 31, 2018. Unrecognized compensation cost for unvested RSU’s outstanding at December 31, 2018 $25,000 0.5 Restricted Stock We have granted restricted stock to certain board members. A summary of our restricted stock activity for the year ended December 31, 2018 Shares of Weighted- Outstanding at January 1, 2018 49,960 $ 3.00 Granted 45,046 $ 1.11 Vested (72,483 ) $ 2.41 Forfeited - $ - Outstanding at December 31, 2018 22,523 $ 1.11 The total intrinsic value of the outstanding restricted stock at December 31, 2018 $7,000. December 31, 2018 $84,000. Unrecognized compensation cost for unvested restricted stock outstanding at December 31, 2018 $25,000 0.5 Stock Purchase Warrants We have issued warrants to purchase common stock to certain officers, directors, stockholders and service providers as well as in conjunction with debt and equity offerings and at various times replacement warrants were issued as an inducement for warrant exercises. In May 2016 August 2017, 1,746,173 2,250,000 contained in the warrants. At December 31, 2018, 2,982,709 3 October 2018 2,982,709 $2.00 $0.57 In October 2018, 3,000,000 180,000 $0.75 $0.875, A summary of outstanding warrants at December 31, 2018 Range of Exercise Number of Range of Expiration Dates $0.57 - $0.875 6,162,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 153,755 March 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $47.30 - $52.20 275,897 January 2019 - July 2019 7,077,374 Preferred and Common Stock We have outstanding 1,000,000 4.5% December 2016. 4.5% 3,887,387 In October 2018, 3,000,000 3,000,000 $0.70 $2.1 $0.75 six five one June 23, 2017 ( No. 333 218608 180,000 $0.875 5

Note 5 - Property and Equipment

Note 5 - Property and Equipment	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	Note 5. The major classes of property and equipment December 31: 2018 2017 Furniture and fixtures $ 35,407 $ 35,407 Computers and office equipment 138,897 138,897 Lab equipment 818,267 820,507 992,571 994,811 Less accumulated depreciation (902,260 ) (821,925 ) Property and equipment, net $ 90,311 $ 172,886 The above includes approximately $71,000 December 31, 2018 2017, $84,000 $100,000,

Note 6 - Patents

Note 6 - Patents	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Intangible Assets Disclosure [Text Block]	Note 6. The Company holds patents related to its stem cell and small molecule technologies. Patent costs are capitalized and are being amortized over the life of the patents. The weighted average remaining unamortized life of issued patents was approximately 9.3 December 31, 2018. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not December 31, 2018 2017, no December 31, 2018 2017: 2018 2017 Patent asset $ 2,006,443 $ 2,028,557 Accumulated amortization (1,242,900 ) (1,145,095 ) Net intangibles $ 763,543 $ 883,462 Amortization expense for the years ended December 31, 2018 2017 $102,000 $189,000, five $80,000

Note 7 - Income Taxes

Note 7 - Income Taxes	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	Note 7. Our provision for income taxes for the years ended December 31, 2018 2017 2018 2017 Current provision: Federal $ - $ - State - - Foreign - - Total current provision - - Deferred provision (benefit): Federal 7,726 17,837,120 State (2,749,386 ) 1,417,482 Foreign - - Total deferred provision (benefit) (2,741,660 ) 19,254,602 Valuation allowance 2,741,660 (19,254,602 ) Consolidated income tax provision $ - $ - We provide a full valuation allowance on our net deferred tax assets because management has determined that it is more likely than not not The difference between income taxes computed by applying the statutory federal income tax rate to consolidated losses before income taxes and the consolidated provision for income taxes is attributable to the following: 2018 2017 Federal statutory rate (21.0 %) (34.0 %) State income taxes, net of Federal benefits (5.0 %) (4.1 %) Rate changes (66.3 %) 155.0 % Change in fair value of liability classified warrants (17.3 %) (3.6 %) Other, including non-deductible expenses 53.9 % 9.6 % Valuation allowance 55.7 % (122.9 %) Total 0.0 % 0.0 % The tax effects of significant temporary differences representing deferred tax assets as of December 31, 2018 2017 2018 2017 Net operating loss carryforwards $ 42,580,533 $ 35,610,806 Stock based compensation expense 2,643,471 6,764,508 Tax credit carryforwards and other 1,005,255 1,112,286 Gross deferred tax assets 46,229,259 43,487,600 Valuation allowance (46,229,259 ) (43,487,600 ) Net deferred tax assets $ - $ - The Company had Federal net operating loss (“NOL”) carryforwards of approximately $156.0 $146.4 December 31, 2018 2017, 2018. 2036. may may not not 2015. Impact of the Tax Cuts and Jobs Act of 2017 On December 22, 2017, 2017 2018 • Reduction of the corporate tax rate from 35% 21% • Elimination of the alternative minimum tax • Changes in the deductibility of certain aspects of executive compensation • Changes in the deductibility of certain entertainment and recreation expenses • Changes in incentive tax breaks for U.S production activities. Because of the Company’s existing Federal net operating loss carryforwards and current expectations as to the recovery of its net deferred tax assets, the Company believes that the Tax Act will not

Note 8 - Commitments and Contin

Note 8 - Commitments and Contingencies	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 5. We currently operate one one 1,500 $5,700 December 31, 2018. In 2015, 3,100 $13,000 August 31, 2019. April 2018, $62,200 March 31, 2019. We also lease a research facility in People’s Republic of China. This lease expires on September 30, 2019 $3,800 From time to time, we are parties to legal proceedings that we believe to be ordinary, routine litigation incidental to the business. We are currently not	Note 8. We currently operate one one 1,500 $5,700 December 31, 2018. In 2015, 3,100 $12,000 August 31, 2019. May 2017, $92,000 April 2018, $50,000 $87,000 December 31, 2018. We also lease a research facility in People’s Republic of China. This lease expires on March 31, 2019 $3,800 Future minimum payments under all leases at December 31, 2018 Year Amount 2019 115,000 2020 - 2021 - 2022 - 2023 and thereafter - Total minimum payments $ 115,000 The Company recognized approximately $164,000 $161,000, December 31, 2018 2017, From time to time, we are parties to legal proceedings that we believe to be ordinary, routine litigation incidental to the business. We are currently not The Company is currently obligated under a written employment agreement with our Chief Scientific Officer (“CSO”). Pursuant to the terms of the agreement, our CSO receives annual salary of $500,000.

Note 9 - Related Party Receivab

Note 9 - Related Party Receivable	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	Note 6. On August 10, 2016, six $658,000 The $658,000 $199,000 In March 2019, 50% March 31, 2019, $229,000 July 2025. not	Note 9. On August 10, 2016, six $658,000 The $658,000 $199,000 $458,000 December 31, 2018 $100,000 July 2022. In March 2019,

Note 10 - Subsequent Events

Note 10 - Subsequent Events	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes to Financial Statements
Subsequent Events [Text Block]	Note 7. None.	Note 10. None

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation In management’s opinion, the accompanying interim unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring adjustments, which are necessary to present fairly our financial position, results of operations and cash flows. The unaudited condensed consolidated balance sheet at December 31, 2018, not may not 10 December 31, 2018, may	Basis of Presentation Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The financial statements include the accounts of the Company and our wholly owned subsidiary. All significant intercompany transactions and balances have been eliminated.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The unaudited condensed consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates.	Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The consolidated financial statements include significant estimates for the expected economic life and value of our licensed technology and related patents, our net operating loss and related valuation allowance for tax purposes, the fair value of our liability classified warrants and our share-based compensation related to employees and directors, consultants and advisors, among other things. Because of the use of estimates inherent in the financial reporting process, actual results could differ significantly from those estimates.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3	Fair Value Measurements The carrying amounts of our short-term financial instruments, which primarily include cash and cash equivalents, short-term investments, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of our long-term indebtedness was estimated based on the quoted prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities and approximates the carrying value. The fair values of our liability classified warrants were estimated using Level 3 3
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss.	Foreign Currency Translation The functional currency of our wholly owned foreign subsidiary is its local currency. Assets and liabilities of our foreign subsidiary are translated into United States dollars based on exchange rates at the end of the reporting period; income and expense items are translated at the weighted average exchange rates prevailing during the reporting period. Translation adjustments for subsidiary are accumulated in other comprehensive income or loss, a component of stockholders' equity. Transaction gains or losses are included in the determination of net loss.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash, Cash Equivalents and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents. Our investment policy, approved by our Board of Directors, limits the amount we may one not	Cash, Cash Equivalents, Short-Term Investments and Credit Risk Cash equivalents consist of investments in low risk, highly liquid money market accounts and certificates of deposit with original maturities of 90 may Short-term investments consist entirely of fixed income certificates of deposit (“CDs”) with original maturities of greater than 90 not one Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and short-term investments. Our investment policy, approved by our Board of Directors, limits the amount we may one not
Revenue from Contract with Customer [Policy Text Block]	Revenue The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers; (ii) identification of distinct performance obligations in the contract; (iii) determination of contract transaction price; (iv) allocation of contract transaction price to the performance obligations; and (v) determination of revenue recognition based on timing of satisfaction of the performance obligation. The Company recognizes revenues upon the satisfaction of its performance obligation (upon transfer of control of promised goods or services to customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those goods or services. Deferred revenue results from cash receipts from or amounts billed to customers in advance of the transfer of control of the promised services to the customer and is recognized as performance obligations are satisfied. When sales commissions or other costs to obtain contracts with customers are considered incremental and recoverable, those costs are deferred and then amortized as selling and marketing expenses on a straight-line basis over an estimated period of benefit.	Revenue On January 1, 2018, 606, not January 1, 2018.
Research and Development Expense, Policy [Policy Text Block]	Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the three March 31, 2019 2018, $95,000 $84,000,	Research and Development Research and development costs are expensed as they are incurred. Research and development expenses consist primarily of costs associated with the pre-clinical development and clinical trials of our product candidates. For the years ended December 31, 2018 2017, $538,000 $41,000,
Earnings Per Share, Policy [Policy Text Block]	Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the three March 31, 2019 2018. 13.5 9.5 three March 31, 2019 2018,	Income (Loss) per Common Share Basic income (loss) per common share is computed by dividing total net income (loss) available to common stockholders by the weighted average number of common shares outstanding during the period. For periods of net income when the effects are dilutive, diluted earnings per share is computed by dividing net income available to common stockholders by the weighted average number of shares outstanding and the dilutive impact of all dilutive potential common shares. Dilutive potential common shares consist primarily of convertible preferred stock, stock options, restricted stock units and common stock purchase warrants. The dilutive impact of potential common shares resulting from common stock equivalents is determined by applying the treasury stock method. Our unvested restricted shares contain non-forfeitable rights to dividends, and therefore are considered to be participating securities; the calculation of basic and diluted income per share excludes net income attributable to the unvested restricted shares from the numerator and excludes the impact of the shares from the denominator. For all periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all dilutive potential common shares is anti-dilutive due to the net losses; accordingly, diluted loss per share is the same as basic loss per share for the years ended December 31, 2018 2017. 12.6 10.2 December 31, 2018 2017,
Share-based Payment Arrangement [Policy Text Block]	Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants is generally determined at the grant date using an option pricing model that uses Level 3	Share-Based Compensation We account for share-based compensation at fair value. Share-based compensation cost for stock options and stock purchase warrants granted to employees and board members is generally determined at the grant date while awards granted to non-employee consultants are generally valued at the vesting date using an option pricing model that uses Level 3
Goodwill and Intangible Assets, Policy [Policy Text Block]	Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No three March 31, 2019 2018.	Intangible and Long-Lived Assets We assess impairment of our long-lived assets using a "primary asset" approach to determine the cash flow estimation period for a group of assets and liabilities that represents the unit of accounting for a long-lived asset to be held and used. Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not not No December 31, 2018 2017.
Income Tax, Policy [Policy Text Block]	Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not”	Income Taxes We account for income taxes using the asset and liability approach, which requires the recognition of future tax benefits or liabilities on the temporary differences between the financial reporting and tax bases of our assets and liabilities. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. We also recognize a tax benefit from uncertain tax positions only if it is “more likely than not” Corporate tax rate changes resulting from the impacts of the Tax Cuts and Jobs Act of 2017 December 31, 2018 2017.
Lessee, Leases [Policy Text Block]	Leases We determine if an arrangement is or contains a lease at its inception. We have made accounting policy elections whereby we (i) do not 12 not ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Rent expense is recognized on a straight-line basis over the lease term. We currently have one 12 August 2019 $49,600 March 31, 2019. $29,800 three March 31, 2019. not 12.75% March 31, 2019, $33,900 $48,100, We also have two not $47,300 $47,100 March 31, 2019 2018, 2019 $16,900 In addition, in April 2018, $62,200 $24,200 March 31, 2019.
New Accounting Pronouncements, Policy [Policy Text Block]	Significant New Accounting Pronouncements Recently Adopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 may January 1, 2019 not not $53,000 $75,700 In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. January 1, 2019. not Unadopted Guidance In June 2016, ASU No. 2016 13, December 15, 2019, not In August 2018, ASU 2018 13, 820 December 15, 2019 In August 2018, ASU 2018 15, December 15, 2019 We have reviewed other recent accounting pronouncements and concluded that they are either not no	Significant New Accounting Pronouncements Recently Adopted Guidance In May 2014, Accounting Standard Update (“ASU”), No. 2014 09, December 15, 2017. may January 1, 2018 not In May 2017, ASU No. 2017 09, December 15, 2017 January 1, 2018 not In July 2017, ASU No. 2017 11, no December 15, 2018 January 1, 2018, not Unadopted Guidance In February 2016, ASU, No. 2016 02, December 15, 2018 not $50,000 $75,000 In June 2016, ASU No. 2016 13, December 15, 2019, December 15, 2018, not In June 2018, ASU 2018 07, ASC 718, 1 2 3 December 15, 2018. not In August 2018, ASU 2018 13, 820 December 15, 2019. In August 2018, ASU 2018 15, December 15, 2019. We have reviewed other recent accounting pronouncements and concluded that they are either not no

Note 3 - Fair Value Measureme_3

Note 3 - Fair Value Measurements (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 Liability classified stock purchase warrants $ - $ - $ 923,849 $ 923,849 Balance at March 31, 2019 $ - $ - $ 923,849 $ 923,849	Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 3,852,882 $ 3,852,882 Balance at December 31, 2017 $ - $ - $ 3,852,882 $ 3,852,882 Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Mark-to-market Balance at December 31, 2018 $ 583,734 Change in fair value - loss 340,115 Balance at March 31, 2019 $ 923,849 Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (190,219 ) Balance at March 31, 2018 $ 3,662,663	Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (3,269,148 ) Balance at December 31, 2018 $ 583,734 Mark-to-market Balance at December 31, 2016 $ 3,921,917 Issuance of warrants 2,483,848 Exercise of warrants (4,023,057 ) Change in fair value - loss 1,470,174 Balance at December 31, 2017 $ 3,852,882

Note 4 - Stockholders' Equity (

Note 4 - Stockholders' Equity (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes Tables
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31 2019 2018 Research and development expenses $ 200,337 $ 64,583 General and administrative expenses 137,629 174,252 Total $ 337,966 $ 238,835	Year Ended December 31, 2018 2017 Research and development costs $ 133,334 $ 1,091,036 General and administrative expenses 500,748 678,928 Total $ 634,082 $ 1,769,964
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,632,662 $ 10.78 5.1 $ - Granted 800,000 $ 0.43 Exercised - $ - $ - Forfeited - $ - Outstanding at March 31 2019 2,432,662 $ 7.37 6.4 $ 19,040 Exercisable at March 31, 2019 1,795,786 $ 9.78 5.3 $ 5,712	Number of Options Weighted- Weighted- Aggregate Outstanding at January 1, 2018 1,894,077 $ 19.76 4.7 $ 108,000 Granted 488,640 $ 1.13 $ - Exercised - - Forfeited/Expired (750,055 ) $ 27.19 Outstanding at December 31, 2018 1,632,662 $ 10.78 5.1 $ - Exercisable at December 31, 2018 1,166,127 $ 14.59 4.4 $ -
Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]	Range of Exercise Prices Number of Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value $0.40 - $0.50 800,000 $ 0.43 9.7 $ 19,040 $1.00 - $3.50 588,640 $ 1.15 7.1 - $3.51 - $13.00 532,236 $ 9.76 4.1 - $13.01 - $26.00 343,782 $ 14.79 2.8 - $26.01 - $39.00 65,504 $ 30.85 2.2 - $39.01 - $56.00 102,500 $ 45.03 4.3 - 2,432,662 $ 7.37 6.4 $ 19,040	Range of Exercise Prices Number of Options Weighted- Weighted- Aggregate $1.00 - $3.50 588,640 $ 1.15 7.3 $ - $3.51 - $13.00 532,236 $ 9.76 4.3 - $13.01 - $26.00 343,782 $ 14.79 3.1 - $26.01 - $39.00 65,504 $ 30.85 2.5 - $39.01 - $56.00 102,500 $ 45.03 4.6 - 1,632,662 $ 10.78 5.1 $ -
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended March 31, 2019 Annual dividend - Expected life (in years) 5.4 - 5.5 Risk free interest rate 2.4% - 2.5% Expected volatility 97%	Year Ended December 31, 2018 2017 Annual dividend - - Expected life (in years) 2.5 - 5.3 0.3 - 6.5 Risk free interest rate 2.5% - 2.8% 0.80% - 2.22% Expected volatility 97% - 113% 62.2% - 98.0%
Schedule of Share-based Compensation, Warrant Activity [Table Text Block]	Range of Exercise Prices Number of Warrants Outstanding Range of Expiration Dates $0.30 - $0.875 6,662,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 44,233 December 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $52.31 11,539 July 2019 7,203,494	Range of Exercise Number of Range of Expiration Dates $0.57 - $0.875 6,162,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 153,755 March 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $47.30 - $52.20 275,897 January 2019 - July 2019 7,077,374

Note 3 - Fair Value Measureme_4

Note 3 - Fair Value Measurement (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734 Liability classified stock purchase warrants $ - $ - $ 923,849 $ 923,849 Balance at March 31, 2019 $ - $ - $ 923,849 $ 923,849	Level 1 Level 2 Level 3 Total Liabilities Liability classified stock purchase warrants $ - $ - $ 3,852,882 $ 3,852,882 Balance at December 31, 2017 $ - $ - $ 3,852,882 $ 3,852,882 Liability classified stock purchase warrants $ - $ - $ 583,734 $ 583,734 Balance at December 31, 2018 $ - $ - $ 583,734 $ 583,734
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Mark-to-market Balance at December 31, 2018 $ 583,734 Change in fair value - loss 340,115 Balance at March 31, 2019 $ 923,849 Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (190,219 ) Balance at March 31, 2018 $ 3,662,663	Mark-to-market Balance at December 31, 2017 $ 3,852,882 Change in fair value - gain (3,269,148 ) Balance at December 31, 2018 $ 583,734 Mark-to-market Balance at December 31, 2016 $ 3,921,917 Issuance of warrants 2,483,848 Exercise of warrants (4,023,057 ) Change in fair value - loss 1,470,174 Balance at December 31, 2017 $ 3,852,882

Note 4 - Stockholders' Equity_2

Note 4 - Stockholders' Equity 10K (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Notes Tables
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31 2019 2018 Research and development expenses $ 200,337 $ 64,583 General and administrative expenses 137,629 174,252 Total $ 337,966 $ 238,835	Year Ended December 31, 2018 2017 Research and development costs $ 133,334 $ 1,091,036 General and administrative expenses 500,748 678,928 Total $ 634,082 $ 1,769,964
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,632,662 $ 10.78 5.1 $ - Granted 800,000 $ 0.43 Exercised - $ - $ - Forfeited - $ - Outstanding at March 31 2019 2,432,662 $ 7.37 6.4 $ 19,040 Exercisable at March 31, 2019 1,795,786 $ 9.78 5.3 $ 5,712	Number of Options Weighted- Weighted- Aggregate Outstanding at January 1, 2018 1,894,077 $ 19.76 4.7 $ 108,000 Granted 488,640 $ 1.13 $ - Exercised - - Forfeited/Expired (750,055 ) $ 27.19 Outstanding at December 31, 2018 1,632,662 $ 10.78 5.1 $ - Exercisable at December 31, 2018 1,166,127 $ 14.59 4.4 $ -
Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]	Range of Exercise Prices Number of Options Outstanding Weighted-Average Exercise Price Weighted-Average Remaining Contractual Life (in years) Aggregate Intrinsic Value $0.40 - $0.50 800,000 $ 0.43 9.7 $ 19,040 $1.00 - $3.50 588,640 $ 1.15 7.1 - $3.51 - $13.00 532,236 $ 9.76 4.1 - $13.01 - $26.00 343,782 $ 14.79 2.8 - $26.01 - $39.00 65,504 $ 30.85 2.2 - $39.01 - $56.00 102,500 $ 45.03 4.3 - 2,432,662 $ 7.37 6.4 $ 19,040	Range of Exercise Prices Number of Options Weighted- Weighted- Aggregate $1.00 - $3.50 588,640 $ 1.15 7.3 $ - $3.51 - $13.00 532,236 $ 9.76 4.3 - $13.01 - $26.00 343,782 $ 14.79 3.1 - $26.01 - $39.00 65,504 $ 30.85 2.5 - $39.01 - $56.00 102,500 $ 45.03 4.6 - 1,632,662 $ 10.78 5.1 $ -
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended March 31, 2019 Annual dividend - Expected life (in years) 5.4 - 5.5 Risk free interest rate 2.4% - 2.5% Expected volatility 97%	Year Ended December 31, 2018 2017 Annual dividend - - Expected life (in years) 2.5 - 5.3 0.3 - 6.5 Risk free interest rate 2.5% - 2.8% 0.80% - 2.22% Expected volatility 97% - 113% 62.2% - 98.0%
Schedule of Share-based Compensation, Warrant Activity [Table Text Block]	Range of Exercise Prices Number of Warrants Outstanding Range of Expiration Dates $0.30 - $0.875 6,662,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 44,233 December 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $52.31 11,539 July 2019 7,203,494	Range of Exercise Number of Range of Expiration Dates $0.57 - $0.875 6,162,709 May 2021 - August 2024 $1.11 - $5.79 34,617 May 2021 - May 2023 $12.80 - $12.90 39,296 January 2022 $16.20 - $16.30 174,544 March 2020 $22.10 - $27.90 153,755 March 2019 - January 2021 $34.50 - $39.20 236,556 October 2019 - October 2021 $47.30 - $52.20 275,897 January 2019 - July 2019 7,077,374
Restricted Stock [Member]
Notes Tables
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]		Shares of Weighted- Outstanding at January 1, 2018 49,960 $ 3.00 Granted 45,046 $ 1.11 Vested (72,483 ) $ 2.41 Forfeited - $ - Outstanding at December 31, 2018 22,523 $ 1.11
Restricted Stock Units (RSUs) [Member]
Notes Tables
Share-based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]		Number of Weighted- Outstanding at January 1, 2018 11,235 $ 11.77 Granted 45,046 $ 1.11 Exercised and converted to common shares - $ - Forfeited - $ - Outstanding at December 31, 2018 56,281 $ 3.24 Exercisable at December 31, 2018 33,759 $ 4.66

Note 5 - Property and Equipme_2

Note 5 - Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Property, Plant and Equipment [Table Text Block]	2018 2017 Furniture and fixtures $ 35,407 $ 35,407 Computers and office equipment 138,897 138,897 Lab equipment 818,267 820,507 992,571 994,811 Less accumulated depreciation (902,260 ) (821,925 ) Property and equipment, net $ 90,311 $ 172,886

Note 6 - Patents (Tables)

Note 6 - Patents (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Finite-Lived Intangible Assets [Table Text Block]	2018 2017 Patent asset $ 2,006,443 $ 2,028,557 Accumulated amortization (1,242,900 ) (1,145,095 ) Net intangibles $ 763,543 $ 883,462

Note 7 - Income Taxes (Tables)

Note 7 - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	2018 2017 Current provision: Federal $ - $ - State - - Foreign - - Total current provision - - Deferred provision (benefit): Federal 7,726 17,837,120 State (2,749,386 ) 1,417,482 Foreign - - Total deferred provision (benefit) (2,741,660 ) 19,254,602 Valuation allowance 2,741,660 (19,254,602 ) Consolidated income tax provision $ - $ -
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	2018 2017 Federal statutory rate (21.0 %) (34.0 %) State income taxes, net of Federal benefits (5.0 %) (4.1 %) Rate changes (66.3 %) 155.0 % Change in fair value of liability classified warrants (17.3 %) (3.6 %) Other, including non-deductible expenses 53.9 % 9.6 % Valuation allowance 55.7 % (122.9 %) Total 0.0 % 0.0 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	2018 2017 Net operating loss carryforwards $ 42,580,533 $ 35,610,806 Stock based compensation expense 2,643,471 6,764,508 Tax credit carryforwards and other 1,005,255 1,112,286 Gross deferred tax assets 46,229,259 43,487,600 Valuation allowance (46,229,259 ) (43,487,600 ) Net deferred tax assets $ - $ -

Note 8 - Commitments and Cont_2

Note 8 - Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Year Amount 2019 115,000 2020 - 2021 - 2022 - 2023 and thereafter - Total minimum payments $ 115,000

Note 1 - Organization, Busine_3

Note 1 - Organization, Business and Financial Condition (Details Textual)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Number of Operating Segments	1	1

Note 2 - Significant Accounti_3

Note 2 - Significant Accounting Policies and Basis of Presentation (Details Textual) - USD ($) shares in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Cost Reimbursements from SBIR Grant as Offset to Research and Development Expenses	$ 95,000	$ 84,000	$ 538,000	$ 41,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	13.5	9.5	12.6	10.2
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 49,600
Operating Lease, Payments	$ 29,800
Lessee, Operating Lease, Discount Rate	12.75%
Operating Leases, Rent Expense, Net, Total	$ 47,300	$ 47,100
Operating Leases, Rent Expense, Sublease Rentals	62,200
Sublease Income	24,200
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset					$ 53,000
Operating Lease, Liability, Total					$ 75,700
Short-term Leases [Member]
Operating Leases, Rent Expense, Net, Total	16,900
Other Noncurrent Assets [Member]
Operating Lease, Right-of-Use Asset	33,900
Other Current Liabilities [Member]
Operating Lease, Liability, Total	$ 48,100
Minimum [Member]
Lessee, Operating Lease, Term of Contract	1 year

Note 3 - Fair Value Measureme_5

Note 3 - Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair value of liabilities	$ 923,849	$ 583,734	$ 3,852,882
Stock Purchase Warrants [Member]
Liability classified stock purchase warrants	923,849	583,734	3,852,882
Fair Value, Inputs, Level 1 [Member]
Fair value of liabilities
Fair Value, Inputs, Level 1 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants
Fair Value, Inputs, Level 2 [Member]
Fair value of liabilities
Fair Value, Inputs, Level 2 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants
Fair Value, Inputs, Level 3 [Member]
Fair value of liabilities	923,849	583,734	3,852,882
Fair Value, Inputs, Level 3 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants	$ 923,849	$ 583,734	$ 3,852,882

Note 3 - Fair Value Measureme_6

Note 3 - Fair Value Measurements - Activity for Items Measured at Fair Value on a Recurring Basis (Details) - Stock Purchase Warrants [Member] - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 583,734	$ 3,852,882	$ 3,852,882	$ 3,921,917
Change in fair value - loss	340,115	(190,219)	(3,269,148)	1,470,174
Balance	$ 923,849	$ 3,662,663	$ 583,734	$ 3,852,882

Note 4 - Stockholders' Equity_3

Note 4 - Stockholders' Equity (Details Textual) - USD ($)	1 Months Ended					3 Months Ended			12 Months Ended
	Apr. 30, 2019	Oct. 31, 2018	Aug. 31, 2017	Dec. 31, 2016	May 31, 2016	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period						10 years			10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant						10,900,000			10,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value							$ 0.34		$ 0.47	$ 1.34
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross						800,000		0	488,640
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount						$ 250,000			$ 179,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition						292 days			1 year 328 days
Additional Research and Development Expense Due to Modifications						$ 102,000
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance									7,077,374
Private Placement [Member]
Class of Warrant or Right, Issued During Period		3,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.75
Warrants and Rights Outstanding, Term		5 years 182 days
Stock Issued During Period, Shares, New Issues		3,000,000
Series A 4.5% Convertible Preferred Stock [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Converted	465,191
Stock Issued During Period, Shares, Conversion of Convertible Securities	1,808,377
Series A 4.5% Convertible Preferred Stock [Member] | Private Placement [Member]
Stock Issued During Period, Shares, New Issues				1,000,000
Preferred Stock, Dividend Rate, Percentage				4.50%
Convertible Preferred Stock, Issuable Upon Conversion of All Shares				3,887,387
Stock Purchase Warrants [Member]
Class of Warrant or Right, Issued During Period			2,250,000		1,746,173	500,000
Class of Warrant or Right, Outstanding						2,982,709			2,982,709
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.57				$ 0.30	$ 2
Class of Warrant or Right, Granted During Period, Weighted Average Grant Date Fair Value						$ 0.19
Class of Warrant or Right, Vesting Percentage on Grant						25.00%
Class of Warrant or Right, Vesting Percentage on Completion of Initial Services						75.00%
Warrants and Rights Outstanding, Term						2 years 182 days
Stock Purchase Warrants [Member] | Measurement Input, Expected Dividend Rate [Member]
Warrants and Rights Outstanding, Measurement Input						0
Stock Purchase Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input						0.025
Stock Purchase Warrants [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input						1.1
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition									182 days
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted						0		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period						0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance						33,758
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Weighted Average Grant Date Fair Value						$ 4.66
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding						$ 15,200			$ 17,000
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised						0			0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested										$ 23,000
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount									$ 25,000
Restricted Stock [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition						91 days			182 days
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted						0		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period									72,483
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding									$ 7,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value						$ 1.11			$ 2.41
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested						$ 5,100			$ 84,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance						11,262
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Ending Balance						$ 1.11
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount						$ 12,500			$ 25,000

Note 4 - Stockholders' Equity -

Note 4 - Stockholders' Equity - Share-based Compensation Expense (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based compensation expense	$ 337,966	$ 238,835	$ 634,082	$ 1,769,964
Research and Development Expense [Member]
Share-based compensation expense	200,337	64,583	133,334	1,091,036
General and Administrative Expense [Member]
Share-based compensation expense	$ 137,629	$ 174,252	$ 500,748	$ 678,928

Note 4 - Stockholders' Equity_4

Note 4 - Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Options Outstanding (in shares)	1,632,662	1,894,077	1,894,077
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 10.78	$ 19.76	$ 19.76
Weighted- average remaining contractual life (Year)	6 years 146 days		5 years 36 days	4 years 255 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	800,000	0	488,640
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0.43		$ 1.13
Options Outstanding (in shares)	2,432,662		1,632,662	1,894,077
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.37		$ 10.78	$ 19.76
Aggregate intrinsic value	$ 19,040			$ 108,000
Options Exercisable (in shares)	1,795,786		1,166,127
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 9.78		$ 14.59
Options Exercisable, Weighted Average Remaining Contractual Life (Year)	5 years 109 days		4 years 146 days
Options Exercisable, Aggregate Intrinsic Value	$ 5,712

Note 4 - Stockholders' Equity_5

Note 4 - Stockholders' Equity - Stock Options by Exercise Price Range (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of options outstanding (in shares)	2,432,662	1,632,662
Weighted- average exercise price (in dollars per share)	$ 7.37	$ 10.78
Weighted- average remaining contractual life (Year)	6 years 146 days	5 years 36 days	4 years 255 days
Aggregate intrinsic value	$ 19,040		$ 108,000
Range One [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 0.40	$ 1
Range of exercise prices, upper limit (in dollars per share)	$ 0.50	$ 3.50
Number of options outstanding (in shares)	800,000	588,640
Weighted- average exercise price (in dollars per share)	$ 0.43	$ 1.15
Weighted- average remaining contractual life (Year)	9 years 255 days	7 years 109 days
Aggregate intrinsic value	$ 19,040
Range Two [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 1	$ 3.51
Range of exercise prices, upper limit (in dollars per share)	$ 3.50	$ 13
Number of options outstanding (in shares)	588,640	532,236
Weighted- average exercise price (in dollars per share)	$ 1.15	$ 9.76
Weighted- average remaining contractual life (Year)	7 years 36 days	4 years 109 days
Aggregate intrinsic value
Range Three [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 3.51	$ 13.01
Range of exercise prices, upper limit (in dollars per share)	$ 13	$ 26
Number of options outstanding (in shares)	532,236	343,782
Weighted- average exercise price (in dollars per share)	$ 9.76	$ 14.79
Weighted- average remaining contractual life (Year)	4 years 36 days	3 years 36 days
Aggregate intrinsic value
Range Four [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 13.01	$ 26.01
Range of exercise prices, upper limit (in dollars per share)	$ 26	$ 39
Number of options outstanding (in shares)	343,782	65,504
Weighted- average exercise price (in dollars per share)	$ 14.79	$ 30.85
Weighted- average remaining contractual life (Year)	2 years 292 days	2 years 182 days
Aggregate intrinsic value
Range Five [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 26.01	$ 39.01
Range of exercise prices, upper limit (in dollars per share)	$ 39	$ 56
Number of options outstanding (in shares)	65,504	102,500
Weighted- average exercise price (in dollars per share)	$ 30.85	$ 45.03
Weighted- average remaining contractual life (Year)	2 years 73 days	4 years 219 days
Aggregate intrinsic value
Range Six [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 39.01
Range of exercise prices, upper limit (in dollars per share)	$ 56
Number of options outstanding (in shares)	102,500
Weighted- average exercise price (in dollars per share)	$ 45.03
Weighted- average remaining contractual life (Year)	4 years 109 days
Aggregate intrinsic value

Note 4 - Stockholders' Equity_6

Note 4 - Stockholders' Equity - Fair Value Assumptions for Stock Options (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Annual dividend
Expected volatility	97.00%
Minimum [Member]
Expected life (Year)	5 years 146 days	2 years 182 days	109 days
Risk free interest rate	2.40%	2.50%	0.80%
Expected volatility		97.00%	62.20%
Maximum [Member]
Expected life (Year)	5 years 182 days	5 years 109 days	6 years 182 days
Risk free interest rate	2.50%	2.80%	2.22%
Expected volatility		113.00%	98.00%

Note 4 - Stockholders' Equity_7

Note 4 - Stockholders' Equity - Summary of Warrant Activity (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance		7,077,374
Stock Purchase Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	7,203,494
Range One [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 0.875	$ 0.875
Lower exercise price range (in dollars per share)	$ 0.30	$ 0.57
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	6,662,709	6,162,709
Range One [Member] | Stock Purchase Warrants [Member] | Minimum [Member]
Expiration dates	Aug. 31, 2024
Range One [Member] | Stock Purchase Warrants [Member] | Maximum [Member]
Expiration dates	May 31, 2021
Range Two [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)		$ 5.79
Lower exercise price range (in dollars per share)	$ 1.11	$ 1.11
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	34,617	34,617
Range Two [Member] | Stock Purchase Warrants [Member] | Minimum [Member]
Upper range of exercise prices (in dollars per share)	$ 5.79
Expiration dates	May 31, 2023
Range Two [Member] | Stock Purchase Warrants [Member] | Maximum [Member]
Expiration dates	May 31, 2021
Range Three [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 12.90	$ 12.90
Lower exercise price range (in dollars per share)	$ 12.80	$ 12.80
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	39,296	39,296
Expiration dates	Jan. 31, 2022
Range Four [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 16.30	$ 16.30
Lower exercise price range (in dollars per share)	$ 16.20	$ 16.20
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	174,544	174,544
Expiration dates	Mar. 31, 2020
Range Five [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 27.90
Lower exercise price range (in dollars per share)	$ 22.10
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	44,233
Range Five [Member] | Stock Purchase Warrants [Member] | Minimum [Member]
Expiration dates	Jan. 31, 2021
Range Five [Member] | Stock Purchase Warrants [Member] | Maximum [Member]
Expiration dates	Dec. 31, 2019
Range Six [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 39.20	$ 27.90
Lower exercise price range (in dollars per share)	$ 34.50	$ 22.10
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	236,556	153,755
Range Six [Member] | Stock Purchase Warrants [Member] | Minimum [Member]
Expiration dates	Oct. 31, 2021
Range Six [Member] | Stock Purchase Warrants [Member] | Maximum [Member]
Expiration dates	Oct. 31, 2019
Range Seven [Member] | Stock Purchase Warrants [Member]
Upper range of exercise prices (in dollars per share)	$ 52.31	$ 39.20
Lower exercise price range (in dollars per share)	$ 52.31	$ 34.50
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance	11,539	236,556
Expiration dates	Jul. 31, 2019

Note 5 - Commitments and Cont_2

Note 5 - Commitments and Contingencies (Details Textual)	3 Months Ended	12 Months Ended
	Mar. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)ft²	Dec. 31, 2015ft²
UNITED STATES
Number of Facilities	1	1
CHINA
Number of Facilities	1	1
Lease Monthly Payment	$ 3,800	$ 3,800
Germantown, MD [Member]
Area of Real Estate Property | ft²	1,500	1,500
Lease Monthly Payment	$ 5,700	$ 5,700
San Diego, CA [Member]
Area of Real Estate Property | ft²			3,100
Lease Monthly Payment	13,000	12,000
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals	$ 62,200	$ 87,000

Note 6 - Related Party Receiv_2

Note 6 - Related Party Receivable (Details Textual) - Chief Scientific Officer [Member] - Repayment Agreement of Improperly Expense Reimbursement [Member] - USD ($)	Aug. 10, 2016	Mar. 31, 2019	Dec. 31, 2018
Due from Related Parties, Term	6 years
Due from Related Parties, Total	$ 658,000	$ 229,000	$ 458,000
Due from Related Party, Discount	$ 199,000

Note 1 - Organization, Busine_4

Note 1 - Organization, Business and Financial Condition (Details Textual)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Number of Operating Segments	1	1

Note 2 - Significant Accounti_4

Note 2 - Significant Accounting Policies and Basis of Presentation (Details Textual) - USD ($) shares in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Cost Reimbursements from SBIR Grant as Offset to Research and Development Expenses	$ 95,000	$ 84,000	$ 538,000	$ 41,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	13.5	9.5	12.6	10.2
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset					$ 53,000
Operating Lease, Liability, Total					75,700
Accounting Standards Update 2016-02 [Member] | Subsequent Event [Member]
Operating Lease, Right-of-Use Asset					50,000
Operating Lease, Liability, Total					$ 75,000

Note 3 - Fair Value Measureme_7

Note 3 - Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value for a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair value of liabilities	$ 923,849	$ 583,734	$ 3,852,882
Stock Purchase Warrants [Member]
Liability classified stock purchase warrants	923,849	583,734	3,852,882
Fair Value, Inputs, Level 1 [Member]
Fair value of liabilities
Fair Value, Inputs, Level 1 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants
Fair Value, Inputs, Level 2 [Member]
Fair value of liabilities
Fair Value, Inputs, Level 2 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants
Fair Value, Inputs, Level 3 [Member]
Fair value of liabilities	923,849	583,734	3,852,882
Fair Value, Inputs, Level 3 [Member] | Stock Purchase Warrants [Member]
Liability classified stock purchase warrants	$ 923,849	$ 583,734	$ 3,852,882

Note 3 - Fair Value Measureme_8

Note 3 - Fair Value Measurements - Activity for Items Measured at Fair Value for a Recurring Basis (Details) - Stock Purchase Warrants [Member] - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 583,734	$ 3,852,882	$ 3,852,882	$ 3,921,917
Change in fair value - loss	340,115	(190,219)	(3,269,148)	1,470,174
Issuance of warrants				2,483,848
Exercise of warrants				(4,023,057)
Balance	$ 923,849	$ 3,662,663	$ 583,734	$ 3,852,882

Note 4 - Stockholders' Equity_8

Note 4 - Stockholders' Equity 10K (Details Textual) - USD ($)	Dec. 12, 2018	Oct. 31, 2018	Aug. 31, 2017	Dec. 31, 2016	May 31, 2016	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period						10 years				10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant						10,900,000	10,800,000			10,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value								$ 0.34		$ 0.47	$ 1.34
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value										$ 205,000	$ 302,000
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount						$ 250,000	$ 179,000			$ 179,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition						292 days				1 year 328 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross						800,000			0	488,640
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price						$ 0.43				$ 1.13
Private Placement [Member]
Class of Warrant or Right, Issued During Period		3,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.75
Stock Issued During Period, Shares, New Issues		3,000,000
Shares Issued, Price Per Share		$ 0.70
Proceeds from Issuance of Private Placement		$ 2,100,000
Warrants and Rights Outstanding, Term		5 years 182 days
Private Placement [Member] | Series A 4.5% Convertible Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues				1,000,000
Preferred Stock, Dividend Rate, Percentage				4.50%
Convertible Preferred Stock, Issuable Upon Conversion of All Shares				3,887,387
Stock Purchase Warrants [Member]
Class of Warrant or Right, Issued During Period			2,250,000		1,746,173	500,000
Class of Warrant or Right, Outstanding						2,982,709	2,982,709			2,982,709
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.57				$ 0.30		$ 2
Warrants and Rights Outstanding, Term						2 years 182 days
Stock Purchase Warrants Issued to Placement Agent [Member]
Class of Warrant or Right, Issued During Period		180,000					180,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.875					$ 0.875			$ 0.875
Warrants and Rights Outstanding, Term							5 years			5 years
Stock Purchase Warrants Issued to Investor [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.75
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition										182 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding						$ 15,200	$ 17,000			$ 17,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value										$ 50,000	25,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested											$ 23,000
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised						0				0
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount							25,000			$ 25,000
Restricted Stock [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition						91 days				182 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding							7,000			$ 7,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested						$ 5,100				84,000
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount						$ 12,500	$ 25,000			$ 25,000
Inducement Award Stock Option Plan [Member] | Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	800,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0.425
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	200,000
Inducement Award Stock Option Plan [Member] | Chief Executive Officer [Member] | Vest Over Two Year Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	200,000
Inducement Award Stock Option Plan [Member] | Chief Executive Officer [Member] | Vest Based on Achiement of Certain Milestones [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	400,000
Inducement Award Stock Option Plan [Member] | Chief Executive Officer [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years

Note 4 - Stockholders' Equity_9

Note 4 - Stockholders' Equity - Share based Compensation Expense (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Share-based compensation expense	$ 337,966	$ 238,835	$ 634,082	$ 1,769,964
Research and Development Expense [Member]
Share-based compensation expense	200,337	64,583	133,334	1,091,036
General and Administrative Expense [Member]
Share-based compensation expense	$ 137,629	$ 174,252	$ 500,748	$ 678,928

Note 4 - Stockholders' Equit_10

Note 4 - Stockholders' Equity - Summary for Stock Option Activity (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Options Outstanding (in shares)	1,632,662	1,894,077	1,894,077
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 10.78	$ 19.76	$ 19.76
Weighted- average remaining contractual life (Year)	6 years 146 days		5 years 36 days	4 years 255 days
Aggregate intrinsic value	$ 19,040			$ 108,000
Options Granted (in shares)	800,000	0	488,640
Options Granted, Weighted Average Exercise Price (in dollars per share)	$ 0.43		$ 1.13
Options Exercised (in shares)
Options Forfeited/Expired (in shares)			(750,055)
Options Forfeited/Expired, Weighted Average Exercise Price (in dollars per share)			$ 27.19
Options Outstanding (in shares)	2,432,662		1,632,662	1,894,077
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.37		$ 10.78	$ 19.76
Options Exercisable (in shares)	1,795,786		1,166,127
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 9.78		$ 14.59
Options Exercisable, Weighted Average Remaining Contractual Life (Year)	5 years 109 days		4 years 146 days

Note 4 - Stockholders' Equit_11

Note 4 - Stockholders' Equity - Stock Options Exercise Price Range (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of options outstanding (in shares)	2,432,662	1,632,662
Weighted- average exercise price (in dollars per share)	$ 7.37	$ 10.78
Weighted- average remaining contractual life (Year)	6 years 146 days	5 years 36 days	4 years 255 days
Aggregate intrinsic value	$ 19,040		$ 108,000
Range One [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 0.40	$ 1
Range of exercise prices, upper limit (in dollars per share)	$ 0.50	$ 3.50
Number of options outstanding (in shares)	800,000	588,640
Weighted- average exercise price (in dollars per share)	$ 0.43	$ 1.15
Weighted- average remaining contractual life (Year)	9 years 255 days	7 years 109 days
Aggregate intrinsic value	$ 19,040
Range Two [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 1	$ 3.51
Range of exercise prices, upper limit (in dollars per share)	$ 3.50	$ 13
Number of options outstanding (in shares)	588,640	532,236
Weighted- average exercise price (in dollars per share)	$ 1.15	$ 9.76
Weighted- average remaining contractual life (Year)	7 years 36 days	4 years 109 days
Aggregate intrinsic value
Range Three [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 3.51	$ 13.01
Range of exercise prices, upper limit (in dollars per share)	$ 13	$ 26
Number of options outstanding (in shares)	532,236	343,782
Weighted- average exercise price (in dollars per share)	$ 9.76	$ 14.79
Weighted- average remaining contractual life (Year)	4 years 36 days	3 years 36 days
Aggregate intrinsic value
Range Four [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 13.01	$ 26.01
Range of exercise prices, upper limit (in dollars per share)	$ 26	$ 39
Number of options outstanding (in shares)	343,782	65,504
Weighted- average exercise price (in dollars per share)	$ 14.79	$ 30.85
Weighted- average remaining contractual life (Year)	2 years 292 days	2 years 182 days
Aggregate intrinsic value
Range Five [Member]
Range of exercise prices, lower limit (in dollars per share)	$ 26.01	$ 39.01
Range of exercise prices, upper limit (in dollars per share)	$ 39	$ 56
Number of options outstanding (in shares)	65,504	102,500
Weighted- average exercise price (in dollars per share)	$ 30.85	$ 45.03
Weighted- average remaining contractual life (Year)	2 years 73 days	4 years 219 days
Aggregate intrinsic value

Note 4 - Stockholders' Equit_12

Note 4 - Stockholders' Equity - Fair Value Assumptions of Stock Options (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Annual dividend
Expected volatility	97.00%
Minimum [Member]
Expected life (Year)	5 years 146 days	2 years 182 days	109 days
Risk free interest rate	2.40%	2.50%	0.80%
Expected volatility		97.00%	62.20%
Maximum [Member]
Expected life (Year)	5 years 182 days	5 years 109 days	6 years 182 days
Risk free interest rate	2.50%	2.80%	2.22%
Expected volatility		113.00%	98.00%

Note 4 - Stockholders' Equit_13

Note 4 - Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Outstanding (in shares)	56,281	11,235
Outstanding, Weighted Average Grant Date Fair Value (in dollars per share)	$ 3.24	$ 11.77
Granted (in shares)		45,046
Granted, Weighted Average Grant Date Fair Value (in dollars per share)		$ 1.11
Exercised and converted to common shares (in shares)	0	0
Exercised and converted to common shares, Weighted Average Grant Date Fair Value (in dollars per share)
Forfeited (in shares)
Forfeited, Weighted Average Grant Date Fair Value (in dollars per share)
Outstanding (in shares)		56,281
Outstanding, Weighted Average Grant Date Fair Value (in dollars per share)		$ 3.24
Exercisable (in shares)		33,759
Exercisable, Weighted Average Grant Date Fair Value (in dollars per share)		$ 4.66

Note 4 - Stockholders' Equit_14

Note 4 - Stockholders' Equity - Summary of Restricted Stock Activity (Details) - Restricted Stock [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Outstanding (in shares)	22,523	49,960
Outstanding, Weighted Average Grant Date Fair Value (in dollars per share)	$ 1.11	$ 3
Granted (in shares)		45,046
Granted, Weighted Average Grant Date Fair Value (in dollars per share)		$ 1.11
Vested (in shares)		(72,483)
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	$ 1.11	$ 2.41
Outstanding (in shares)		22,523
Outstanding, Weighted Average Grant Date Fair Value (in dollars per share)		$ 1.11

Note 4 - Stockholders' Equit_15

Note 4 - Stockholders' Equity - Summary for Warrant Activity (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Number of warrants outstanding (in shares)		7,077,374
Stock Purchase Warrants [Member]
Number of warrants outstanding (in shares)	7,203,494
Stock Purchase Warrants [Member] | Range One [Member]
Lower exercise price range (in dollars per share)	$ 0.30	$ 0.57
Upper range of exercise prices (in dollars per share)	$ 0.875	$ 0.875
Number of warrants outstanding (in shares)	6,662,709	6,162,709
Stock Purchase Warrants [Member] | Range Two [Member]
Lower exercise price range (in dollars per share)	$ 1.11	$ 1.11
Upper range of exercise prices (in dollars per share)		$ 5.79
Number of warrants outstanding (in shares)	34,617	34,617
Stock Purchase Warrants [Member] | Range Three [Member]
Lower exercise price range (in dollars per share)	$ 12.80	$ 12.80
Upper range of exercise prices (in dollars per share)	$ 12.90	$ 12.90
Number of warrants outstanding (in shares)	39,296	39,296
Stock Purchase Warrants [Member] | Range Four [Member]
Lower exercise price range (in dollars per share)	$ 16.20	$ 16.20
Upper range of exercise prices (in dollars per share)	$ 16.30	$ 16.30
Number of warrants outstanding (in shares)	174,544	174,544
Stock Purchase Warrants [Member] | Range Six [Member]
Lower exercise price range (in dollars per share)	$ 34.50	$ 22.10
Upper range of exercise prices (in dollars per share)	$ 39.20	$ 27.90
Number of warrants outstanding (in shares)	236,556	153,755
Stock Purchase Warrants [Member] | Range Seven [Member]
Lower exercise price range (in dollars per share)	$ 52.31	$ 34.50
Upper range of exercise prices (in dollars per share)	$ 52.31	$ 39.20
Number of warrants outstanding (in shares)	11,539	236,556
Stock Purchase Warrants [Member] | Range Nine [Member]
Lower exercise price range (in dollars per share)		$ 47.30
Upper range of exercise prices (in dollars per share)		$ 52.20
Number of warrants outstanding (in shares)		275,897

Note 5 - Property and Equipme_3

Note 5 - Property and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Gross, Ending Balance	$ 992,571	$ 994,811
Depreciation, Total	84,000	$ 100,000
CHINA
Property, Plant and Equipment, Gross, Ending Balance	$ 71,000

Note 5 - Property and Equipme_4

Note 5 - Property and Equipment - Major Classes of Property and Equipment (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and equipment, gross		$ 992,571	$ 994,811
Less accumulated depreciation		(902,260)	(821,925)
Property and equipment, net	$ 75,668	90,311	172,886
Furniture and Fixtures [Member]
Property and equipment, gross		35,407	35,407
Office Equipment [Member]
Property and equipment, gross		138,897	138,897
Equipment [Member]
Property and equipment, gross		$ 818,267	$ 820,507

Note 6 - Patents (Details Textu

Note 6 - Patents (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years 109 days
Asset Impairment Charges, Total	$ 0	$ 0
Amortization of Intangible Assets, Total	102,000	$ 189,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	80,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	80,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	80,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	80,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 80,000

Note 6 - Patents - Intangible A

Note 6 - Patents - Intangible Assets and Accumulated Amortization (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Patent asset	$ 2,006,443	$ 2,028,557
Accumulated amortization	(1,242,900)	(1,145,095)
Net intangibles	$ 763,543	$ 883,462

Note 7 - Income Taxes (Details

Note 7 - Income Taxes (Details Textual) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards, Total	$ 156	$ 146.4

Note 7 - Income Taxes - Provisi

Note 7 - Income Taxes - Provision for Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Federal
State
Foreign
Total current provision
Federal	7,726	17,837,120
State	(2,749,386)	1,417,482
Foreign		0
Total deferred provision (benefit)	(2,741,660)	19,254,602
Valuation allowance	2,741,660	(19,254,602)
Consolidated income tax provision

Note 7 - Income Taxes - Effecti

Note 7 - Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Federal statutory rate	(21.00%)	(34.00%)
State income taxes, net of Federal benefits	(5.00%)	(4.10%)
Rate changes	(66.30%)	155.00%
Change in fair value of liability classified warrants	(17.30%)	(3.60%)
Other, including non-deductible expenses	53.90%	9.60%
Valuation allowance	55.70%	(122.90%)
Total	0.00%	0.00%

Note 7 - Income Taxes - Tax Eff

Note 7 - Income Taxes - Tax Effects of Significant Temporary Differences Representing Deferred Tax Assets (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Net operating loss carryforwards	$ 42,580,533	$ 35,610,806
Stock based compensation expense	2,643,471	6,764,508
Tax credit carryforwards and other	1,005,255	1,112,286
Gross deferred tax assets	46,229,259	43,487,600
Valuation allowance	(46,229,259)	(43,487,600)
Net deferred tax assets

Note 8 - Commitments and Cont_3

Note 8 - Commitments and Contingencies (Details Textual)	1 Months Ended	3 Months Ended	4 Months Ended	12 Months Ended
	May 31, 2017USD ($)	Mar. 31, 2019USD ($)ft²	Apr. 30, 2018USD ($)	Dec. 31, 2018USD ($)ft²	Dec. 31, 2017USD ($)	Dec. 31, 2015ft²
Operating Leases, Rent Expense, Total				$ 164,000	$ 161,000
Chief Scientific Officer [Member]
Officers' Yearly Compensation				$ 500,000
UNITED STATES
Number of Facilities		1		1
CHINA
Number of Facilities		1		1
Lease Monthly Payment		$ 3,800		$ 3,800
Germantown, MD [Member]
Area of Real Estate Property | ft²		1,500		1,500
Lease Monthly Payment		$ 5,700		$ 5,700
San Diego, CA [Member]
Area of Real Estate Property | ft²						3,100
Lease Monthly Payment		13,000		12,000
Gain (Loss) on Termination of Lease	$ (92,000)		$ (50,000)
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals		$ 62,200		$ 87,000

Note 8 - Commitments and Cont_4

Note 8 - Commitments and Contingencies - Future Minimum Payments Under All Leases (Details)	Dec. 31, 2018USD ($)
2019	$ 115,000
2020
2021
2022
2023 and thereafter
Total minimum payments	$ 115,000

Note 9 - Related Party Receiv_2

Note 9 - Related Party Receivable (Details Textual) - Chief Scientific Officer [Member] - Repayment Agreement of Improperly Expense Reimbursement [Member] - USD ($)	Aug. 10, 2016	Dec. 31, 2018	Mar. 31, 2019
Due from Related Parties, Term	6 years
Due from Related Parties, Total	$ 658,000	$ 458,000	$ 229,000
Due from Related Party, Discount	$ 199,000
Due from Related Party, Annual Installments		$ 100,000