目的:探讨超声引导下细针穿刺活检(ultrasound guided fine needle aspiration biopsy,US-FNAB)对甲状腺结节的诊断价值。方法:回顾性分析天津医科大学总医院2016年1月至2017年4月行US-FNAB检查的甲状腺结节患者的临床特点及细胞病理诊...目的:探讨超声引导下细针穿刺活检(ultrasound guided fine needle aspiration biopsy,US-FNAB)对甲状腺结节的诊断价值。方法:回顾性分析天津医科大学总医院2016年1月至2017年4月行US-FNAB检查的甲状腺结节患者的临床特点及细胞病理诊断结果,对细胞诊断结果和手术病理结果进行对照分析。结果:在1 241例病例中,甲状腺结节男女比1:3.83(257/984),甲状腺结节的发病率从20岁开始逐年增加,60岁以后发病率开始下降。肿瘤最大径≤1.0 cm的结节640例(51.57%),TI-RADS 4级的结节1 072例(86.38%)。细胞学诊断结果中无法诊断的病例273例(22.00%),良性121例(9.75%),意义不明确的细胞非典型病变380例(30.62%),可疑恶性399例(32.15%),恶性68例(5.48%)。其中在天津医科大学总医院行手术的302例患者中,US-FNAB细胞病理有明确诊断203例,无法诊断21例,意义不明确的细胞非典型病变78例。203例明确诊断的病例中,US-FNAB诊断的灵敏度为100.00%(201/201),特异度为50.00%(1/2),阳性预测值99.50%(201/202),阴性预测值100.00%(1/1),诊断的准确率99.51%(202/203),误诊率0.49%(1/203)。在细胞学诊断为意义不明确的细胞非典型病变的78例中,恶性率70.51%。意义不明确细胞非典型病变是否为恶性与患者的年龄、性别、肿瘤大小和部位均无关(均P>0.05),与甲状腺超声影像报告和数据系统(thyroid imaging reporting and data system,TI-RADS)分级有关(P<0.05)。结论:US-FNAB对甲状腺结节有较高的诊断价值,值得推广应用,可以考虑部分代替术中冰冻,减少术中等候时间和患者的经济负担。展开更多
Rock bolt anchorage performance is crucial for tunnel support safety.We investigate the mechanical behaviour of reinforced rock and the bolts that reinforce it from the micro-scale to the macro-scale.Bolt pull-out tes...Rock bolt anchorage performance is crucial for tunnel support safety.We investigate the mechanical behaviour of reinforced rock and the bolts that reinforce it from the micro-scale to the macro-scale.Bolt pull-out tests were performed on soft rock using the distinct element method,in which a new contact model that considers bond size,is employed to constrain the main rock mechanical behaviour.The minimum sample width and height values for which the boundary effect can be neglected are first proposed through numerous tests on the influence of sample size on peak load and bond breakage.The influence of sample width is substantially greater than that of sample height.We then select an appropriate sample size to study the influence of bolt embedment length and confining pressure on the mechanical behaviours of the rock and bolt.The results show that increased rock bolt embedment length and confining pressure can increase the peak load;however,the bolt length effect is limited when exceeding the critical anchorage length.In cases without confining pressure,bond breakage occurs in the rock around the grout-rock interface and the breakage zone is rectangular,whereas in cases under confining pressure,the breakage zone presents an inverted cone shape.We use our results to discuss the influence of bond strength at the bolt-grout interface on the peak load and failure mode.The failure mode changes gradually from complex failure to single failure along the bolt-grout interface with decreasing interfacial bond strength.展开更多
文摘目的:探讨超声引导下细针穿刺活检(ultrasound guided fine needle aspiration biopsy,US-FNAB)对甲状腺结节的诊断价值。方法:回顾性分析天津医科大学总医院2016年1月至2017年4月行US-FNAB检查的甲状腺结节患者的临床特点及细胞病理诊断结果,对细胞诊断结果和手术病理结果进行对照分析。结果:在1 241例病例中,甲状腺结节男女比1:3.83(257/984),甲状腺结节的发病率从20岁开始逐年增加,60岁以后发病率开始下降。肿瘤最大径≤1.0 cm的结节640例(51.57%),TI-RADS 4级的结节1 072例(86.38%)。细胞学诊断结果中无法诊断的病例273例(22.00%),良性121例(9.75%),意义不明确的细胞非典型病变380例(30.62%),可疑恶性399例(32.15%),恶性68例(5.48%)。其中在天津医科大学总医院行手术的302例患者中,US-FNAB细胞病理有明确诊断203例,无法诊断21例,意义不明确的细胞非典型病变78例。203例明确诊断的病例中,US-FNAB诊断的灵敏度为100.00%(201/201),特异度为50.00%(1/2),阳性预测值99.50%(201/202),阴性预测值100.00%(1/1),诊断的准确率99.51%(202/203),误诊率0.49%(1/203)。在细胞学诊断为意义不明确的细胞非典型病变的78例中,恶性率70.51%。意义不明确细胞非典型病变是否为恶性与患者的年龄、性别、肿瘤大小和部位均无关(均P>0.05),与甲状腺超声影像报告和数据系统(thyroid imaging reporting and data system,TI-RADS)分级有关(P<0.05)。结论:US-FNAB对甲状腺结节有较高的诊断价值,值得推广应用,可以考虑部分代替术中冰冻,减少术中等候时间和患者的经济负担。
基金support for this study from the National Natural Science Foundation of China(Grant Nos.11872281,11572228)the State Key Laboratory of Disaster Reduction in Civil Engineering(SLDRCE19-A-06).
文摘Rock bolt anchorage performance is crucial for tunnel support safety.We investigate the mechanical behaviour of reinforced rock and the bolts that reinforce it from the micro-scale to the macro-scale.Bolt pull-out tests were performed on soft rock using the distinct element method,in which a new contact model that considers bond size,is employed to constrain the main rock mechanical behaviour.The minimum sample width and height values for which the boundary effect can be neglected are first proposed through numerous tests on the influence of sample size on peak load and bond breakage.The influence of sample width is substantially greater than that of sample height.We then select an appropriate sample size to study the influence of bolt embedment length and confining pressure on the mechanical behaviours of the rock and bolt.The results show that increased rock bolt embedment length and confining pressure can increase the peak load;however,the bolt length effect is limited when exceeding the critical anchorage length.In cases without confining pressure,bond breakage occurs in the rock around the grout-rock interface and the breakage zone is rectangular,whereas in cases under confining pressure,the breakage zone presents an inverted cone shape.We use our results to discuss the influence of bond strength at the bolt-grout interface on the peak load and failure mode.The failure mode changes gradually from complex failure to single failure along the bolt-grout interface with decreasing interfacial bond strength.
