Purpose Triacetone triperoxide (TATP) is a volatile but powerful explosive that appeals to terrorists due to its ease of synthesis from household items. For this reason, bomb squad, canine (K9) units, and scientists must work with this material to mitigate this threat. However, no information on the metabolism of TATP is available. Methods In vitro experiments using human liver microsomes and recombinant enzymes were performed on TATP and TATP-OH for metabolite identification and enzyme phenotyping. Enzyme kinetics for TATP hydroxylation were also investigated. Urine from laboratory personnel collected before and after working with TATP was analyzed for TATP and its metabolites. Results While experiments with flavin monooxygenases were inconclusive, those with recombinant cytochrome P450s (CYPs) strongly suggested that CYP2B6 was the principle enzyme responsible for TATP hydroxylation. TATP-O-glucuronide was also identified and incubations with recombinant uridine diphosphoglucuronosyltransferases (UGTs) indicated that UGT2B7 catalyzes this reaction. Michaelis-Menten kinetics were determined for TATP hydroxylation, with K m = 1.4 µM and V max = 8.7 nmol/min/nmol CYP2B6. TATP-O-glucuronide was present in the urine of all three volunteers after being exposed to TATP vapors showing good in vivo correlation to in vitro data. TATP and TATP-OH were not observed. Conclusions Since scientists working to characterize and detect TATP to prevent terrorist attacks are constantly exposed to this volatile compound, attention should be paid to its metabolism. This paper is the first to elucidate some exposure, metabolism and excretion of TATP in humans and to identify a marker of TATP exposure, TATP-O-glucuronide in urine.
One of the major issues during the regression test of the new version of Real Time Operating System (RTOS) is the time involved in test case execution. The main reason being a single embedded system device under test (DUT) is used to execute the test list containing several test cases. This traditional method of regression test also leads to wasted productivity of the other devices at hand that could be otherwise used during this regression test. Hence, in this paper, we propose a technique that aims at reducing the overall regression test cycle time of a newer version of a Real Time Operating System (RTOS) by employing a method known as “test-list sharding” in a distributed test environment. In the proposed work, multiple DUTs are connected to the test server via a communication network. The test server executes the test list containing several test cases and performs the test-list sharding, that is, distributing test cases to different DUTs and executing them in parallel. After the test is executed on the DUT, the test results are sent back to the test server which will summarize all the results. In the proposed work, the sharding is done by distributing the test cases without overloading or under loading any of the DUTs. Test list is sharded in such a way that the same tests are not sent to multiple DUTs. The main advantage of the proposed method is that the test sharding can be easily scalable to accommodate any number of devices that can be connected to the test server. Also, the test list sharding is done in a dynamic way so that the tests are distributed to an idle DUT that has completed a test execution and ready for another test to execute. The comparison study of executing a sample test list sequentially on a single DUT and distributed test system with multiple DUTs is performed. Results obtained showed the performance gain in terms of test cycle time reduction, scalability, equal load distribution and effective resource utilization.
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