Note 11 - Segments - Segments (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Revenue	$ 490,110		$ 371,591		$ 730,005	$ 686,159
Net loss	(3,923,368)	$ (3,421,802)	(10,391,324)	$ (3,370,715)	(7,345,170)	(13,762,039)
Assets	20,967,006				20,967,006		$ 25,734,644
Operating Segments [Member] | Pittsburgh [Member]
Revenue	13,844		72,025		24,471	94,005
Net loss	(1,594,587)		(8,500,745)		(2,753,692)	(9,815,259)
Assets	3,585,939				3,585,939		1,055,228
Operating Segments [Member] | Eagan [Member]
Revenue	391,386		276,854		607,005	556,124
Net loss	(281,687)		(101,434)		(567,084)	(150,035)
Assets	1,171,354				1,171,354		946,394
Operating Segments [Member] | Birmingham [Member]
Revenue	84,880		22,225		98,529	35,141
Net loss	(585,443)		(396,100)		(1,068,139)	(798,928)
Assets	1,201,404				1,201,404		1,353,434
Corporate, Non-Segment [Member]
Revenue	0		487		0	889
Net loss	(1,461,651)		$ (1,393,045)		(2,956,255)	$ (2,997,817)
Assets	$ 15,008,309				$ 15,008,309		$ 22,379,588