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In order to study the fatigue crack propagation of the fuselage skin under uniform pressurized cyclic load, experiments were carried out with the self-made aircraft fuselage skin uniform pressurized fatigue device. Firstly, the stress intensity factor was calculated by the extended finite element method. Then, the deflection angle of the crack was calculated based on the maximum circumferential stress criterion and the strain energy density factor criterion, and the fatigue crack propagation path of the fuselage skin was predicted. Finally, the fatigue fracture was analyzed under scanning electron microscope. The results show that the crack propagation paths predicted by the two criteria are basically consistent with the crack propagation path obtained by experiment.The surface cracks of the fuselage skin are mixed mode cracks. With the increase of the crack length, KⅠ first increases and then decreases, KⅡ first decreases rapidly to around 0, then oscillates around 0, and finally increases rapidly when the lower hole is about to penetrate. Observing the fatigue fracture shows that the fatigue cracks are initiated by multiple fatigue sources. The crack propagation zone has typical quasi-cleavage fracture characteristics, and the fatigue crack growth rate first increases and then decreases with the increase of crack length. The instantaneous fracture zone is a typical dimple feature with different sizes.

Background: NOTCH mutations (NOTCHmut) are recognized as major oncogenic drivers associated with controversial clinical impact on T‐cell acute lymphoblastic leukemia (T‐ALL), whereas their clinical value on acute myeloid leukemia (AML) is poorly defined. Methods: A study involving 878 consecutive newly diagnosed patients with AML was undertaken in an institution with available clinical data to unravel the impact of NOTCHmut on prognosis. Results: In the study, NOTCHmut were discovered in 3.6% (32/878) of included patients with AML and composed substitution‐missense, frameshift mutation, substitution‐nonsense, and insertion‐in frame. These mutations were more commonly associated with low platelet (29 vs 42 × 109/L, p =.024) count and coexisted with BCOR/BCORL1 (15.6% vs 3.2%, p =.001), DNMT3A (28.1% vs 12.5%, p =.021), and MPL (9.4% vs 0.8%, p =.004) mutations compared with NOTCH wild‐type (NOTCHwt). No significant difference was observed in treatment responses between NOTCHmut and NOTCHwt. The presence of NOTCHmut was associated with worse overall survival ([OS], 1 year‐OS: 68.0% vs 84.2%; 3 year‐OS: 48.3% vs 59.6%; p =.059) and relapse‐free survival ([RFS], 1 year‐RFS: 78.3% vs 85.4%; 3 year‐RFS: 54.5% vs 76.9%; p =.018), especially within the European Leukemia Net 2017 intermediate‐risk group. Furthermore, allogeneic hematopoietic stem cell transplantation might abrogate the dismal impact of NOTCHmut on RFS. In multivariate analysis, NOTCHmut were found to be an independent factor negatively influencing RFS (hazard ratio, 2.153; 95% CI, 1.166‐3.975; p =.014). Conclusion: This study suggests that NOTCHmut may serve as an indicator for poor prognosis of AML. Plain language summary: Although NOTCH mutations (NOTCHmut) are well studied in T‐cell acute lymphoblastic leukemia (T‐ALL), less is known about their incidence and prognostic implications in acute myeloid leukemia (AML).A total of 878 newly diagnosed patients with AML was retrospectively analyzed; it was found that the frequency of NOTCHmut was relatively low but was associated with an adverse prognosis. A retrospective study in a large cohort of 878 patients with acute myeloid leukemia (AML) was performed, and the study suggested that NOTCH mutations may serve as indicators for poor prognosis of AML. [ABSTRACT FROM AUTHOR]