Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Cash flows from operating activities:
Net loss	$ (14,217)	$ (16,693)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation expenses	87	285
Share-based compensation	722	2,255
Non-cash operating lease expenses	747	702
Unrealized gain on short-term investments	0	(3)
Gain on sale of subsidiary interests	(6,986)	0
Changes in assets and liabilities:
Short-term investments	254	(64)
Advances to suppliers	(18)	(19)
Prepaid expenses and other current assets	64	10
Other noncurrent assets	(42)	(117)
Accounts payable	(76)	(607)
Accrued expenses	1,842	(387)
Operating lease liabilities	(709)	(631)
Other current liabilities	268	(163)
Deferred revenue	(2,001)	(1,001)
Other noncurrent liabilities	296	(10)
Net cash used in operating activities	(19,769)	(16,443)
Cash flows from investing activities:
Acquisitions of property and equipment	(50)	(224)
Purchase of short-term investments	(14,949)	(12,788)
Proceeds from maturity of short-term investments	18,432	1,000
Proceeds from sale of subsidiary interests	7,354	0
Net cash (used in) provided by investing activities	10,787	(12,012)
Cash flows from financing activities:
Proceeds from issuance of ordinary shares	2,000	3,000
Capital contribution from noncontrolling interests	2,720	20,000
Proceeds from loans	286	3,911
Net cash provided by financing activities	4,968	26,785
us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperationsAbstract
Effect of foreign exchange rate changes	105	(33)
Net decrease in cash and cash equivalents	(3,909)	(1,703)
Cash and cash equivalents from continuing operations at beginning of year	2,922	15,337
Cash and cash equivalents and from discontinued operations at beginning of year	13,125	2,413
Less: cash and cash equivalents from discontinued operations at end of year	4,352	13,125
Cash and cash equivalents from continuing operations at end of year	7,786	2,922
Supplemental disclosures of cash flow information
Interest paid	0	0
Interest received	311	148
Income taxes paid	2	7
Non-cash investing and financing activities:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	40	0
Issuance costs accrued in accrued expenses	8	0
Parent [Member]
Cash flows from operating activities:
Net loss	(1,006)	(11,123)
Cash flows from financing activities:
Payments of stock issuance costs	(12)	(30)
Noncontrolling Interest [Member]
Cash flows from operating activities:
Net loss	(13,211)	(5,570)
Cash flows from financing activities:
Payments of stock issuance costs	$ (26)	$ (96)