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Stock-Based Compensation and Warrants - Stock incentive plan and other information (Details) - USD ($) |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
Sep. 05, 2019 | Nov. 02, 2010 | Dec. 31, 2022 | Dec. 31, 2021 | Sep. 17, 2020 | Mar. 20, 2007
Stock-Based Compensation and Warrants |  |  |  |  |  |
Unrecognized stock-based compensation expense |  |  | $ 997,000 |  |  |
Proceeds from Stock Options Exercised |  |  | 0 | $ 0 |  |
General and Administrative Expenses and Research and Development Expense | Employees |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Allocated share-based compensation expense |  |  | $ 260,000 | $ 204,000 |  |
Employees And Directors |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, grants in period, gross |  |  | 1,728,000 | 2,260,000 |  |
Consultant | General and Administrative Expenses and Research and Development Expense |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Allocated share-based compensation expense |  |  | $ 215,000 | $ 212,000 |  |
Employees | General and Administrative Expenses and Research and Development Expense |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Allocated share-based compensation expense |  |  | $ 700,000 | $ 500,000 |  |
2007 Stock Plan |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, outstanding, number |  |  | 515 |  |  | 7,143
2010 Stock Plan |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, outstanding, number |  | 8,572 |  |  |  |
Share-based compensation arrangement by share-based payment award, number of shares authorized | 400,000 |  |  |  |  |
Share-based compensation arrangement by share-based payment award, shares issued |  |  | 0 |  |  |
2010 Stock Plan | Board of Directors |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, outstanding, number |  |  | 202,381 |  |  |
2010 Stock Plan | Minimum |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, grants, expired period |  | 5 years |  |  |  |
2010 Stock Plan | Maximum |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, grants, expired period |  | 10 years |  |  |  |
2020 Stock Plan |  |  |  |  |  |
Stock-Based Compensation and Warrants |  |  |  |  |  |
Share-based payment award, options, outstanding, number |  |  | 2,093,002 |  | 400,000 |
Share-based compensation arrangement by share-based payment award, number of shares authorized |  |  | 7,000,000 |  |  |

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