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3138 Background: Actionable muts in EGFR and ALK define two molecular subtypes sensitive to EGFR-TKIs and ALK-TKIs, respectively. Although generally mutually exclusive, they did co-exist in some cases. However, when and how do they co-exist are not well understood. Methods: Pts with concurrent actionable muts in ALK and EGFR were selected from our database. Their mutation profiles and treatment histories were analyzed. PFS was estimated using Kaplan-Meier method. Results: Among 341 ALK-positive ( ALK-pos) and 3804 EGFR-positive ( EGFR-pos) pts, 9 (2.6% of ALK-pos, 0.2% of EGFR-pos) had concurrent EGFR and ALK actionable muts, including 3 EX19Indel + EML4-ALK, 2 EX19Indel + STRN-ALK, 2 L858R + L1152R, 1 L858R + EML4-ALK, and 1 G719C + S768I + STRN-ALK. All 9 pts had lung cancer. One pt with EX19Indel + EML4-ALK was treatment naïve. The other 8 pts have taken ≥ 1 EGFR-TKIs. The mPFS of these pts on first-generation EGFR-TKIs was 22 mo (95% CI: 11 - NR). Except for 1 pt who progressed on Gefitinib and subsequently on Osimertinib had a T790M+C797G, the other 7 EGFR-TKI resistance pts had no common known resistance muts. 3 pts ordered NGS tests before taking EGFR-TKIs. None of them had ALK muts at that time. Later, 1 pt (19Indel) gained an STRN-ALK after 15 mo on Osimertinib, 1 pt (L858R) gained an EML4-ALK after 5 mo on Gefitinib, and 1 pt (L858R) gained an L1152R after 10 mo on Afatinib. Therefore, ALK muts were likely developed as resistance mechanisms during EGFR-TKIs therapies in these 3 pts. Unfortunately, with no information on ALK status before EGFR-TKI therapies, we can not tell if the ALK muts were also developed during and conferred resistance to EGFR-TKI therapies in the other 5 pts. Both STRN-ALK and ALK L1152R were recorded 4 times in our database, and they concurred with EGFR actionable muts in 3 and 2 of the 4 records, respectively. Conclusions: ALK and EGFR actionable muts concurred at a relatively low frequency in our pts. In some cases, ALK muts were developed during EGFR-TKI therapies. Developed either together or sequentially, some combinations of EGFR and ALK muts, such as L858R with L1152R and EX19Indel with ALK fusion, may form more easily or may be preferable than other combinations for the development or evoluation of tumors.

Biaxial load was applied on the tube specimen by the inert gases medium, the inner pressure creep property of domestic Mo-3Nb alloy single crystal were studied. Up to now, the creep experiment has been done at 1600 °C for 3000 hours under three kinds of hoop stress. The three kinds of hoop strees is 5MPa,10 MPa and 15 MPa. Ultimately the creep curves under different conditions were obtained. The steady-state creep rate and the stress exponent in the Sherby-Dorn function have been deduced out. The stress exponent of Mo-3Nb is 5.4. Compare with the Russian single crystal, the creep property is close to Russian's.

A thermal stress aided electroless etching (TSEE) process of epitaxial GaN on sapphire has been demonstrated experimentally and theoretically. The sapphire has been successfully separated from the epitaxial GaN by electroless etching assisted by the thermal peeling stress at the GaN/sapphire interface. ANSYS simulation indicates a sharp increase in peeling stress at the edge of the chip. The mechanism of the TSEE process has been elucidated in macro- and micro-interpretation in this paper, which is based on a charge transfer reaction model with a thermodynamic cycle and an Arrhenius equation. The influences of etching temperature (ET) and etchant concentration (EC) on the TSEE process were quantitatively analyzed based on experimental results. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results show an improvement in the epitaxial GaN crystallinity with the TSEE process. Analysis of the mechanisms of the TSEE process will undoubtedly deepen our understanding of semiconductor etching and facilitate more potential applications.