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Note 8 - Share-based Compensation - Share-based Compensation Expense (Details) - USD ($) | 3 Months Ended
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Mar. 31, 2025 | Mar. 31, 2024
The 2017 Omnibus Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | $ 218,000 | $ 218,000
SEED 2022 Share Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | 26 | 33
Research and Development Expense [Member] | The 2017 Omnibus Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | 26,000 | 58,000
Research and Development Expense [Member] | SEED 2022 Share Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | 8 | 16
General and Administrative Expense [Member] | The 2017 Omnibus Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | 192,000 | 160,000
General and Administrative Expense [Member] | SEED 2022 Share Incentive Plan [Member] |  |
Allocated Share-based Compensation Expense | $ 18 | $ 17

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- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479983/718-10-S45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479830/718-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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