A series of scaled-model shaking table tests and its simulation analyses using dynamic finite element method were performed to clarify the dynamic behaviors and the seismic stability of embedded corrugated steel culve...A series of scaled-model shaking table tests and its simulation analyses using dynamic finite element method were performed to clarify the dynamic behaviors and the seismic stability of embedded corrugated steel culverts due to strong earth-quakes like the 1995 Hyogoken-nanbu earthquake. The dynamic strains of the embedded culvert models and the seismic soil pressure acting on the models due to sinusoidal and random strong motions were investigated. This study verified that the cor-rugated culvert model was subjected to dynamic horizontal forces (lateral seismic soil pressure) from the surrounding ground, which caused the large bending strains on the structure; and that the structures do not exceed the allowable plastic deformation and do not collapse completely during strong earthquake like Hyogoken-nanbu earthquake. The results obtained are useful for design and construction of embedded long span corrugated steel culverts in seismic regions.展开更多
文摘目的探讨恶性周围神经鞘瘤(malignant peripheral nerve sheath tumor,MPNST)患者的临床特征、治疗方式及预后影响因素。方法回顾分析2015年1月1日—2021年12月31日收治的96例MPNST患者资料。男46例,女50例;年龄15~87岁,平均48.2岁。肿瘤位于躯干50例,四肢39例,头颈部7例。肿瘤最大径<5 cm 49例,≥5 cm 32例,缺失15例。肿瘤深度:深部77例,表浅19例。法国国家癌症中心联盟(FNCLCC)组织学分级:G19例,G212例,G334例,缺失41例。37例为复发型MPNST,32例合并Ⅰ型神经纤维瘤病(neurofibromatosis type 1,NF1),26例为Ⅳ期MPNST。25例接受术后辅助放疗,45例接受围术期化疗,30例接受安罗替尼靶向治疗,73例行R0切除。以是否合并NF1分组,比较两组患者上述基线资料。使用Kaplan-Meier法分别绘制每个因素(年龄、性别、是否合并NF1、是否复发型MPNST、是否Ⅳ期MPNST、FNCLCC分级、是否R0切除、肿瘤部位、肿瘤大小、肿瘤深度、是否围术期化疗、是否术后辅助放疗、是否安罗替尼靶向治疗)下各分组人群的1年无疾病生存期(disease-free survival,DFS)和3年总生存期(overall survival,OS)生存曲线,并用Log-Rank检验不同生存曲线间的差异是否有统计学意义。使用多因素COX比例风险模型探索MPNST的独立预后影响因素。结果合并NF1组较未合并NF1组患者肿瘤更多位于表浅、FNCLCC分级较低者更多,差异有统计学意义(P<0.05);其他指标两组间比较差异均无统计学意义(P<0.05)。Kaplan-Meier分析示,是否复发型MPNST、是否Ⅳ期MPNST、FNCLCC分级、是否R0切除、是否围术期化疗以及是否安罗替尼靶向治疗是1年DFS的影响因素(P<0.05),是否Ⅳ期MPNST、FNCLCC分级以及是否围术期化疗是3年OS的影响因素(P<0.05)。多因素COX比例风险模型分析示,对于1年DFS,复发型MPNST和高级别FNCLCC分级(G3)是独立预后影响因素(P<0.05);对于3年OS,Ⅳ期MPNST、肿瘤表浅、>60岁患者、接受术后辅助放疗和接受安罗替尼靶向治疗是独立预后影响因素(P<0.05)。结论合并NF1的MPNST患者肿瘤部位更表浅,FNCLCC分级更低;FNCLCC分级高低、是否R0切除以及是否放化疗与MPNST预后密切相关。建议临床治疗中应优先考虑手术完全切除肿瘤,并结合辅助治疗(如放疗和安罗替尼靶向治疗)以改善患者预后。
文摘A series of scaled-model shaking table tests and its simulation analyses using dynamic finite element method were performed to clarify the dynamic behaviors and the seismic stability of embedded corrugated steel culverts due to strong earth-quakes like the 1995 Hyogoken-nanbu earthquake. The dynamic strains of the embedded culvert models and the seismic soil pressure acting on the models due to sinusoidal and random strong motions were investigated. This study verified that the cor-rugated culvert model was subjected to dynamic horizontal forces (lateral seismic soil pressure) from the surrounding ground, which caused the large bending strains on the structure; and that the structures do not exceed the allowable plastic deformation and do not collapse completely during strong earthquake like Hyogoken-nanbu earthquake. The results obtained are useful for design and construction of embedded long span corrugated steel culverts in seismic regions.
