局部晚期宫颈癌(ⅠB2及ⅡA2期)不同治疗模式的对比研究

目的探讨局部晚期宫颈癌(ⅠB2及ⅡA2期)不同治疗模式的毒性反应及预后。方法2014年1月至2017年12月汕头大学医学院附属肿瘤医院收治的169例ⅠB2及ⅡA2期宫颈癌患者入组,其中同期放化疗组(A组)49例,根治性手术组(B组)58例,新辅助化疗+根治性手术组(C组)62例,分析其临床资料、毒副反应及近期疗效。结果A组、B组、C组胃肠道反应发生率(95.9%vs 75.9%vs 98.4%,P<0.001)、骨髓抑制发生率(71.4%vs 56.9%vs 77.4%,P=0.011)差异均有统计学意义;肝功能损害发生率(8.2%vs 8.6%vs 14.5%,P=0.462)、肾功能损害发生率(4.1%vs 0.0%vs 1.6%,P=0.279)差异均无统计学意义。3~4度胃肠道反应发生率(8.2%vs 6.9%vs 8.1%,P=0.961)、3-4度骨髓抑制发生率(32.7%vs 19.0%vs 14.5%,P=0.059)、3~4度肝功能损害发生率(2.0%vs 0%vs 3.2%,P=0.403)差异均无统计学意义;三组均未出现3~4度肾功能损害。A组、B组、C组2年无复发生存率分别为77.3%、87.0%、87.2%,差异均无统计学意义(P=0.343)。结论局部晚期宫颈癌三种治疗模式严重的毒副反应发生率及近期疗效无明显差异,应根据患者的年龄、体质、对阴道功能及卵巢功能保留的意愿等情况综合考虑,选择合适的治疗模式。

In-situ investigation on the fatigue crack propagation behavior in ferrite-pearlite and dual-phase ferrite-bainite low carbon steels

The purpose of this study was to describe the roles of microstructure types and grain boundary characteristics in fatigue crack propagation behavior in ferrite-pearlite steel and ferrite-bainite steel.The ferrite-bainite dual-phase steel was obtained by intermediate heat treatment conducted on ferrite-pearlite low carbon steel.This paper presents the results from investigation using constant stress-controlled fatigue tests with in-situ scanning electron microscopy(SEM),electron backscattering diffraction(EBSD) and fatigue fractography analysis.Microscopic images arrested by in-situ SEM showed that the second hard bainite phase distributed in the soft ferrite matrix had a significant effect on preventing the cracks opening compared with pearlite,and that the cracks in ferrite-bainite steel were "locked" in the second hard bainite phase while the crack propagation path in ferrite-pearlite steel was more tortuous.Moreover,the fatigue fracture surface analysis and the coincidence site lattice(CSL) obtained by EBSD indicated that low-CSL grain boundaries in ferrite-bainite steel distributed more uniformly,which has a more significant effect on the resistance of crack propagation.It was revealed that ferrite-bainite dual-phase microstructures could inhibit the fatigue crack propagation more effectively than ferrite-pearlite microstructures.

快捷货运列车制动盘与闸片的摩擦磨损特性研究

列车制动系统是涉及列车安全的关键系统之一,基础制动装置摩擦副的摩擦、磨损导致表面温度、应力增加等造成制动失效,仍是制约制动系统寿命的主要原因之一。本文针对160 km/h快捷货运列车基础制动装置在重载荷工况条件下失效原理与故障预测问题,调研分析了货运列车制动盘与闸片的实际工况条件,材料选型与匹配情况;介绍了摩擦磨损试验机的应用情况、工作条件等特点,分析了在摩擦磨损试验机上开展制动盘与闸片微观摩擦材料加速失效测试的可行性,并提出通过等比例试样验证微观摩擦磨损试验结果。该研究有助于解决重载列车制动系统摩擦副材料匹配、失效原因、故障预测等关键技术问题,并且大大降低了实验成本,同时也能够为制动盘与闸片材料磨损寿命预测提供了技术参考和理论依据。