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Thermal barrier coatings (TBCs) and air film-cooling technology have been extensively utilized in nickel-based, single-crystal turbine blades to enhance their heat resistance. However, structural complexity and material property mismatches between layers can affect residual stresses and potentially lead to coating failure. In this study, a three-dimensional finite element model with atmospheric plasma-spraying thermal barrier coatings (APS-TBCs) deposited on air-cooled, nickel-based, single-crystal blades was established to investigate residual stress character under centrifugal load, considering the effect of temperature, crystal orientation deviation angle, oxide layer thickness, and the number of cycles. The results show that when the centrifugal load is increased from 300 MPa to 700 MPa, the absolute value of the residual stress at the crest of the interface between Top Coat (TC) and Thermally Grown Oxide (TGO) increases by only 8.5%, whereas in the region of compressive to tensile stress conversion, residual stress decreases by 100.9%. As the crystal orientation deviation angle increases, the absolute value of the residual compressive stress increases and the absolute value of the residual tensile stress decreases, but the performance is more special in the valley region, where the absolute value of the residual stress increases with the increase in the deviation angle. Special attention is required, as the increase in temperature leads to a rise in the absolute value of residual stress. For example, at the trough of the TC–TGO interface, when the temperature increases from 910 °C to 1100 °C, the residual stress increases by 9.8%. The effect of the number of cycles on residual stress is relatively weak. For instance, at the wave crest of the TC–TGO interface, the residual stress differs by only 0.6 MPa between one cycle and three cycles. The effect of oxide layer thickness on residual stress in the TBCs after a single cycle is nonlinear. When the oxide layer thickness is 0, 4, and 7 μm, the residual stress undergoes a transition between tensile and compressive directions at different locations. The exploration of these results has yielded some valuable laws that can provide a reference for the study of the damage mechanism of TBCs, as well as a guide for the optimization of nickel-based turbine blades in the manufacturing and use processes. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the effects of gestational diabetes mellitus (GDM) on the risk of pregnancy complications in twin pregnancies and to investigate the relationship between glycemic levels and the risk of preeclampsia (PE) and abnormal fetal growth., Patients and Methods: A retrospective cohort study of 736 twin pregnancies was conducted at a tertiary hospital. Propensity score matching and multivariable logistic models were utilized to compare maternal and neonatal outcomes between twin pregnancies with GDM and those without GDM. Multivariable logistic regressions were performed to address the intertwin correlation between glycemic levels and the primary outcomes., Results: There was no significant difference in the risk of PE between non-GDM and GDM pregnancies (OR, 0.70; 95% CI: 0.38-1.27; P = 0.238). No statistically significant differences were observed in the prevalence of small for gestational age and large for gestational age between the study groups. A comparative analysis of twin pregnancies affected by PE and GDM versus those without GDM revealed that the former group exhibited similar maternal and neonatal outcome risks. Women with fasting blood glucose levels from 5.1 mmol/L (92mg/dL) to less than 5.3 mmol/L (95.6mg/dL) had a significantly higher risk of PE compared with women without GDM (OR, 2.90; 95% CI: 1.12-7.51; P = 0.028). In subgroups of glycosylated hemoglobin (HbA1c), HbA1c ≥ 5.5% had the highest risk of PE in the second and third trimesters compared with women without GDM (OR, 4.90; 95% CI: 1.00-24.12; P = 0.05)., Conclusion: The risk of PE was not increased in twin pregnancies complicated with GDM, but significantly increased in women with an HbA1c ≥5.5%. No significant associations were observed between the co-occurrence of GDM and PE and the incidence of pregnancy complications in twin pregnancies. Strict glycemic control may decrease the risk of PE in twin pregnancies with GDM., Competing Interests: The authors report no conflicts of interest in this work., (© 2025 Wu et al.)