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Least risk bomb location(LRBL) structure is a device for placing suspicious explosives on the aircraft.Exploring the influence of structure size and explosive location on its anti-explosion performance can provide a reference for improving the design. Based on the method of combining orthogonal experimental design with numerical simulation, the maximum strain and deformation of each dangerous part of LRBL structure are used as evaluation indicators. The range analysis method and variance analysis method are respectively used to carry out parameter sensitivity analysis on the five influencing factors of the tank wall thickness, bottom cover thickness, connection boss thickness, shear pin diameter and explosive position of LRBL structure. The results show that when the explosive equivalent is determined as 200 g, the significant degree of influence of each factor on the antiknock performance of the LRBL structure from large to small is as follows: explosive position, tank wall thickness, bottom cover thickness, boss thickness and shear pin diameter; Based on comprehensive analysis of evaluation indicators, the LRBL structural design scheme at the optimal level of each factor is obtained.

Background and purpose: For cutaneous and acral malignant melanoma, sentinel lymph node biopsy (SLNB) is an effective tool to evaluate the situation of regional lymph node metastasis and to determine the pathological stage. As an important part of the standard procedure for surgical diagnosis and treatment, SLNB has been recommended in major guidelines and already has a ten-year clinical application. Since the introduction of targeted therapy and immune therapy for malignant melanoma in 2017, the prognosis of patients has been significantly improved. This study aimed to collect the clinical data of Chinese malignant melanoma cases in recent five years so as to discover, in the era of new drug treatment, the significance of sentinel lymph node (SLN) status in clinical application and its influence on survival outcome. Methods: Data of 381 patients with histologically diagnosed malignant melanoma were retrospectively collected from 2017 to 2021 in Fudan University Shanghai Cancer Center. SLNB was performed with wide resection of the primary lesion for each case, and follow-ups of at least 6 months were taken afterwards. Lymphoscintigraphy or methylene blue dye was applied for identification of SLN. Results: A total of 381 patients were included. The mean Breslow thickness was 3.10 mm, among the 381 patients, 69.8% with acral lesion, 59.7% with ulceration, 34.6% with positive SLN, and the median relapse-free survival (RFS) was 17 months. Patient’s survival was significantly influenced by SLN status. Patients with more than 2 biopsied SLN had significantly better RFS in subgroups of N1a stage and T4 stage. There was no significant difference in RFS between patients who received complete lymph node dissection (CLND) and those who did no, and the latter even showed better RFS in subgroups of SLN biopsied number >2 and SLN micrometastasis diameter

Background and purpose: The prognosis of malignant melanoma (MM) in China and Asia is significantly worse than that of European and American populations, mainly because acral melanoma (AM) is inferior to cutaneous melanoma (CM) in terms of biological behavior, clinical features, prognosis, and efficacy of drugs (mainly immunotherapy). Certain changes have occurred in the last 5 years in the choice of surgical and drug-adjuvant treatment for MM. This study retrospectively analyzed the survival outcomes of Chinese CM and AM patients after surgical treatment in a single cancer center for the past five years. Methods:Data of melanoma patients undergoing surgical treatment were retrospectively collected from 2017 to 2021 in Fudan University Shanghai Cancer Center. The basic clinical characteristics, pathological features, lymph node tumor burden and survival information were carefully collected from medical document. Patients with mucosal subtype, unknown primary sites, or follow-up less than 6 months were excluded. Survival analysis and multivariable Cox regression analysis were performed to explore prognosis and associated risk factors. Results:Totally 585 patients were enrolled, including 397 AM and 188 CM patients. The median age was 59 (19-89) years, and 54% were female. AM and CM patients differed in gender, age, primary tumor location, gene mutation distribution and adjuvant therapy, but not in tumor burden associated factors including the Breslow thickness, ulceration and lymph node involvment. The median follow-up time was 24 months, and the median relapse-free survival (mRFS) was 36 months, with 1-year and 2-year RFS of 75.6% and 61.2%, respectively. However, there was no statistically significant difference in prognosis between the two subtypes. Primary ulceration (HR=2.265, 95% CI: 1.257-4.080), NRAS mutation (HR=1.816, 95% CI: 1.211-2.725) and advanced N stage (HR of N1, N2 and N3 versus N0 were 1.850, 4.085 and 4.191, respectively) were independent prognostic risk factors for RFS in AM; while the protective factors were female (HR=0.636, 95% CI: 0.433-0.933) and upper extremity primary lesions (HR=0.259, 95% CI: 0.105-0.639). Independent risk factors for RFS in CM included primary ulceration (HR=4.073, 95% CI: 1.718-9.654), and later N stage (HR=5.482, 95% CI: 2.385-12.601 for N3 stage). Conclusion: High tumor burden of primay lesion still deteriorates overall outcomes for both AM and CM, while harboring NRAS mutation might suggest even worse outcome for AM.