Detection Transformer with Multi-Scale Fusion Attention Mechanism for Aero-Engine Turbine Blade Cast Defect Detection Considering Comprehensive Features.

Casting defects in turbine blades can significantly reduce an aero-engine's service life and cause secondary damage to the blades when exposed to harsh environments. Therefore, casting defect detection plays a crucial role in enhancing aircraft performance. Existing defect detection methods face challenges in effectively detecting multi-scale defects and handling imbalanced datasets, leading to unsatisfactory defect detection results. In this work, a novel blade defect detection method is proposed. This method is based on a detection transformer with a multi-scale fusion attention mechanism, considering comprehensive features. Firstly, a novel joint data augmentation (JDA) method is constructed to alleviate the imbalanced dataset issue by effectively increasing the number of sample data. Then, an attention-based channel-adaptive weighting (ACAW) feature enhancement module is established to fully apply complementary information among different feature channels, and further refine feature representations. Consequently, a multi-scale feature fusion (MFF) module is proposed to integrate high-dimensional semantic information and low-level representation features, enhancing multi-scale defect detection precision. Moreover, R-Focal loss is developed in an MFF attention-based DEtection TRansformer (DETR) to further solve the issue of imbalanced datasets and accelerate model convergence using the random hyper-parameters search strategy. An aero-engine turbine blade defect X-ray (ATBDX) image dataset is applied to validate the proposed method. The comparative results demonstrate that this proposed method can effectively integrate multi-scale image features and enhance multi-scale defect detection precision.

[Protective effect and regulating effect on FXR/SHP gene of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To explore the protective mechanism of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats. METHODS: A total of 88 SPF-grade Wistar male rats were randomized into a normal group, a sham-operation group, a model group and an electroacupuncture (EA) group, 22 rats in each one. The rats in the normal group received normal diet and no intervention was given for 7 d. The rats in the sham-operation and the model group were bound for 20 min, once a day for 7 d. In the EA group, EA, continuous wave, 2 Hz and 1 mA, was applied at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) for 20 min, once a day for 7 d. In the 8th day, the blood was collected by abdominal aortic method 60 min after intraperitoneal injection of 10% urethane anesthesia by 10 mL/kg in the normal group, and then the tissue of heart was collected. In the model group and the EA group, ligating the left anterior descending coronary artery (LAD) was adopted for 20 min and reperfusion was applied for 40 min, then the samples were collected. The rats in the sham-operation group recevied open-chest operation and no other intervention, the samples were collected in 60 min. Nitro Blue Tetrazolium Chloride monohydrate (NBT) stain was used to detected myocardial infarct size and weight, ELISA was used to measured myocardial injury markers and inflammatory factors (LDH、CK、cTnI), and the fluorescent quantitative PCR method was used to determine the expressions of FXR and SHP gene. RESULTS: ①There was no significant difference between the normal group and the sham-operation group in myocardial infarct size and weight (P>0.05) .Compared with the normal group, myocardial infarct size and weight were higher in the model group (P<0.01). Compared with the model group, myocardial infarct size and weight were lower in the EA group (P<0.01). ②There was no significant difference between the normal group and the sham-operation group in serum contents of LDH、CK、cTnI (P>0.05). Compared with the normal group, the serum contents of LDH、CK、cTnI were higher in the model group (P<0.05). Compared with the model group, the serum contents of LDH、CK、cTnI were lower in the EA group (P<0.05). ③The expressions of FXR and SHP gene in the model group were higher than those in the normal group (P<0.05). The expressions of FXR and SHP gene in the EA group were lower than those in the model group (P<0.05). CONCLUSION: Electroacupuncture preconditioning could significantly improve cardiac function of rats with myocardial ischemia-reperfusion, reduce infarct size and inflammatory factors, and down-regulate the expressions of FXR and SHP gene. The protective effect may generate based on regulation of FXR/SHP apoptosis signal pathway.

[Electroacupuncture Relieves Obesity by Up-regulating PGC-1 α/UCP-1 Signaling in White Adipose Tissue in Diet-induced Obesity Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the activities of peroxisome proliferator-activated receptor gamma coactivator-1 alpha/uncoupling protein-1 (PGC-1 α/UCP-1) signaling pathway in white adipose tissue(WAT)of diet-induced obesity (DIO) rats, so as to reveal its underlying mechanism in body weight loss. METHODS: Thirty-four male Wistar rats were randomly divided into normal diet (control, n＝10), high fat diet (model), sham EA-acupoint and EA groups (n＝8 in each of the latter 3 groups). The obesity model was established by feeding the rats with high fat diet containing lard oil, sugar, albumen powder, cholesterol, salt and sodium cholate for 12 weeks. EA (2 Hz/15 Hz, 1 mA) was applied to bilateral "Zusanli" (ST 36) and "Tianshu" (ST 25) or sham acupoints (about 5 mm beside ST 36 and ST 25) for 30 min, once daily, 5 times per week for a total of 8 weeks. During the treatment, all rats were fed with normal diet, and their body weight and length were measured once a week for calculating the Lee's index. The contents of serum total cholesterol (TC) and triglyceride (TG) were measured by using biochemical methods. The immunoactivity of PGC-1 α and UCP-1 in the abdominal WAT was detected by immunohistochemistry. RESULTS: After modeling, the Lee's index, serum TC and TG contents were significantly increased, and the levels of serum HDL-C, and PGC-1 α and UCP-1 immunoactivity in WAT considerably decreased in the model group relevant to the control group (P<0.05). Following the treatment, the Lee's index, TC and TG contents were significantly down-regulated while HDL-C and PGC-1 α and UCP-1 immunoactivity were obviously up-regulated in the EA-acupoint group relevant to the model group (P<0.05). CONCLUSION: EA can effectively reduce the body weight and adipose content in obesity rats, which may be closely related to its effect in up-regulating PGC-1 α/UCP-1 signaling in WAT, suggesting an efficacy of EA in promoting the browning of WAT.