This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anat...This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element（FE） model and a multi-body system （MBS） model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.展开更多
目的建立并验证食管鳞状细胞癌患者根治术后生存预后预测模型与风险分级标准,为术后最优辅助治疗方案的确定提供真实世界证据。方法分别收集2011年5月31日至2018年7月31日在河南省安阳市肿瘤医院(安阳中心)和2009年8月1日至2018年12月3...目的建立并验证食管鳞状细胞癌患者根治术后生存预后预测模型与风险分级标准,为术后最优辅助治疗方案的确定提供真实世界证据。方法分别收集2011年5月31日至2018年7月31日在河南省安阳市肿瘤医院(安阳中心)和2009年8月1日至2018年12月31日在广东省汕头大学医学院附属肿瘤医院(汕头中心)连续就诊的食管鳞状细胞癌患者的临床数据和生存随访数据。以安阳中心数据集为建模集,采用基于多因素Cox比例风险回归逐步后退法和AIC准则(Akaike information criterion)的“两步法”构建总生存预测模型。通过Bootstrap重抽样1000次对模型进行内部统计验证,在汕头中心数据集进行外部验证。根据列线图得分构建预后风险分级标准。结果建模队列和验证队列分别纳入4171例和1895例食管鳞状细胞癌患者。模型由年龄、性别、肿瘤原发位置、T分期、N分期、淋巴结清扫数、肿瘤大小、辅助治疗方案和术前血红蛋白水平9个变量组成。其中,N分期与辅助治疗方案存在显著交互作用(P<0.001),即与单纯手术相比,N+期患者可能从辅助治疗中获益,但辅助治疗无法改善N0期患者的预后。建模队列的模型一致性指数(C-index)为0.728(95%CI:0.713~0.742),经Bootstrap内部验证后为0.722(95%CI:0.711~0.739),验证队列的模型C-index为0.679(95%CI:0.662~0.697)。校准图提示模型预测生存率与观测生存率一致性良好。在两个队列中模型准确性均显著高于第7版AJCC(American Joint Committee on Cancer)TNM分期系统(P<0.05)。此外,在各TNM分期内部,该模型仍可实现理想的预后风险分层效果。结论本研究为我国食管鳞状细胞癌患者根治术后总生存提供了个体化预测模型,并揭示N分期可能是制订食管鳞状细胞癌患者术后辅助治疗方案的重要决定因素。展开更多
基金National Natural Science Foundation of China(No. 10472031).
文摘This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element（FE） model and a multi-body system （MBS） model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.
文摘目的建立并验证食管鳞状细胞癌患者根治术后生存预后预测模型与风险分级标准,为术后最优辅助治疗方案的确定提供真实世界证据。方法分别收集2011年5月31日至2018年7月31日在河南省安阳市肿瘤医院(安阳中心)和2009年8月1日至2018年12月31日在广东省汕头大学医学院附属肿瘤医院(汕头中心)连续就诊的食管鳞状细胞癌患者的临床数据和生存随访数据。以安阳中心数据集为建模集,采用基于多因素Cox比例风险回归逐步后退法和AIC准则(Akaike information criterion)的“两步法”构建总生存预测模型。通过Bootstrap重抽样1000次对模型进行内部统计验证,在汕头中心数据集进行外部验证。根据列线图得分构建预后风险分级标准。结果建模队列和验证队列分别纳入4171例和1895例食管鳞状细胞癌患者。模型由年龄、性别、肿瘤原发位置、T分期、N分期、淋巴结清扫数、肿瘤大小、辅助治疗方案和术前血红蛋白水平9个变量组成。其中,N分期与辅助治疗方案存在显著交互作用(P<0.001),即与单纯手术相比,N+期患者可能从辅助治疗中获益,但辅助治疗无法改善N0期患者的预后。建模队列的模型一致性指数(C-index)为0.728(95%CI:0.713~0.742),经Bootstrap内部验证后为0.722(95%CI:0.711~0.739),验证队列的模型C-index为0.679(95%CI:0.662~0.697)。校准图提示模型预测生存率与观测生存率一致性良好。在两个队列中模型准确性均显著高于第7版AJCC(American Joint Committee on Cancer)TNM分期系统(P<0.05)。此外,在各TNM分期内部,该模型仍可实现理想的预后风险分层效果。结论本研究为我国食管鳞状细胞癌患者根治术后总生存提供了个体化预测模型,并揭示N分期可能是制订食管鳞状细胞癌患者术后辅助治疗方案的重要决定因素。
