2. Summary of Significant Accounting Policies (Details - Property and Equipment) - USD ($) $ in Thousands	Jul. 31, 2019	Apr. 30, 2019
Property and equipment, gross	$ 41,748	$ 40,194
Less: Accumulated depreciation and amortization	(15,295)	(14,569)
Total property and equipment, net	26,453	25,625
Leasehold Improvements [Member]
Property and equipment, gross	20,574	20,574
Laboratory and manufacturing equipment [Member]
Property and equipment, gross	12,983	12,858
Computer Equipment and software [Member]
Property and equipment, gross	4,662	4,644
Furniture, fixtures and office equipment [Member]
Property and equipment, gross	528	528
Construction in Progress [Member]
Property and equipment, gross	$ 3,001	$ 1,590

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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