1 5 . Segments We report information about our operating segments using the management approach in accordance with current accounting standards. This information is based on the way management organizes and reports the segments within the enterprise for making operating decisions and assessing performance. Our reportable segments are identified based on differences in products, services and markets served. There were no inter-segment sales. We manage our business based on two primary types of drug products: (i) diagnostic substances, including Tc 99m tilmanocept and other diagnostic applications of our Manocept platform, and NAV4694 (sublicensed in April 2018), and (ii) therapeutic development programs, including therapeutic applications of our Manocept platform. The information in the following tables is derived directly from each reportable segments financial reporting. Three Months Ended June 30, 2019 Diagnostics Therapeutics Corporate Total Royalty revenue $ 5,940 $  $  $ 5,940 License revenue 9,953   9,953 Grant and other revenue 196,630 47,569  244,199 Total revenue 212,523 47,569  260,092 Cost of revenue 238   238 Research and development expenses 775,462 295,180  1,070,642 Selling, general and administrative expenses, excluding depreciation and amortization (1)  3,062 1,821,812 1,824,874 Depreciation and amortization (2)   36,726 36,726 Loss from operations (3) (563,177 ) (250,673 ) (1,858,538 ) (2,672,388 ) Other expense (4)   (1,590 ) (1,590 ) Income tax benefit 35 16 117 168 Net loss from continuing operations (563,142 ) (250,657 ) (1,860,011 ) (2,673,810 ) Income from discontinued operations, net of tax 632   632 Net loss (562,510 ) (250,657 ) (1,860,011 ) (2,673,178 ) Total assets, net of depreciation and amortization: United States $ 220,334 $ 11,235 $ 7,892,312 $ 8,123,881 International 6,514   6,514 Capital expenditures     Three Months Ended June 30, 201 8 Diagnostics Therapeutics Corporate Total Royalty revenue $ 6,665 $  $  $ 6,665 License revenue 257,709   257,709 Grant and other revenue 156,889 120,864  277,753 Total revenue 421,263 120,864  542,127 Cost of revenue 35,392   35,392 Research and development expenses 913,158 229,560  1,142,718 Selling, general and administrative expenses, excluding depreciation and amortization (1)  16,630 1,735,258 1,751,888 Depreciation and amortization (2)   37,511 37,511 Loss from operations (3) (527,287 ) (125,326 ) (1,772,769 ) (2,425,382 ) Other expense (4)   (20,719 ) (20,719 ) Income tax benefit 2,356 560 8,013 10,929 Net loss from continuing operations (524,931 ) (124,766 ) (1,785,475 ) (2,435,172 ) Loss from discontinued operations, net of tax (1,938 )   (1,938 ) Gain on sale of discontinued operations, net of tax 43,053   43,053 Net loss (483,816 ) (124,766 ) (1,785,475 ) (2,394,057 ) Total assets, net of depreciation and amortization: United States $ 409,769 $ 87,751 $ 8,139,434 $ 8,636,954 International 22,147  1,391 23,538 Capital expenditures   3,165 3,165 Six Months Ended June 30, 2019 Diagnostics Therapeutics Corporate Total Royalty revenue $ 9,090 $  $  $ 9,090 License revenue 9,953   9,953 Grant and other revenue 232,621 50,052  282,673 Total revenue 251,664 50,052  301,716 Cost of revenue 6,364   6,364 Research and development expenses 1,516,045 295,180  1,811,225 Selling, general and administrative expenses, excluding depreciation and amortization (1)  14,776 3,501,835 3,516,611 Depreciation and amortization (2)   73,505 73,505 Loss from operations (3) (1,270,745 ) (259,904 ) (3,575,340 ) (5,105,989 ) Other income (4)   7,122 7,122 Provision for income tax (177 ) (36 ) (495 ) (708 ) Net loss from continuing operations (1,270,922 ) (259,940 ) (3,568,713 ) (5,099,575 ) Loss from discontinued operations, net of tax (2,665 )   (2,665 ) Net loss (1,273,587 ) (259,940 ) (3,568,713 ) (5,102,240 ) Total assets, net of depreciation and amortization: United States $ 220,334 $ 11,235 $ 7,892,312 $ 8,123,881 International 6,514   6,514 Capital expenditures     Six Months Ended June 30, 201 8 Diagnostics Therapeutics Corporate Total Royalty revenue $ 7,460 $  $  $ 7,460 License revenue 257,709   257,709 Grant and other revenue 389,325 164,078  553,403 Total revenue 654,494 164,078  818,572 Cost of revenue 35,710   35,710 Research and development expenses 1,698,169 443,505  2,141,674 Selling, general and administrative expenses, excluding depreciation and amortization (1)  25,237 3,465,036 3,490,273 Depreciation and amortization (2)   75,498 75,498 Loss from operations (3) (1,079,385 ) (304,664 ) (3,540,534 ) (4,924,583 ) Other expense (4)   (4,259,480 ) (4,259,480 ) Income tax benefit 1,284 363 9,282 10,929 Net loss from continuing operations (1,078,101 ) (304,301 ) (7,790,732 ) (9,173,134 ) Loss from discontinued operations, net of tax (1,938 )   (1,938 ) Gain on sale of discontinued operations, net of tax 43,053   43,053 Net loss (1,036,986 ) (304,301 ) (7,790,732 ) (9,132,019 ) Total assets, net of depreciation and amortization: United States $ 409,769 $ 87,751 $ 8,139,434 $ 8,636,954 International 22,147  1,391 23,538 Capital expenditures   3,165 3,165 ( 1 ) General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not currently allocated to our individual reportable segments, other than those expenses directly incurred by MT. ( 2 ) Depreciation and amortization is reflected in selling, general and administrative expenses ( $36,726 and $37,511 for the three -month periods ended June 30, 2019 and 2018, and $73,505 and $75,498 for the six -month periods ended June 30, 2019 and 2018, respectively). ( 3 ) Loss from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by MT. ( 4 ) Amounts consist primarily of losses on debt extinguishment, interest income and interest expense, which are not currently allocated to our individual reportable segments.