For a deeper understanding of the deformation failure behavior of jointed rock, numerical compression simulations are carried out on a rock specimen containing non-persistent joints under confining pressure with the b...For a deeper understanding of the deformation failure behavior of jointed rock, numerical compression simulations are carried out on a rock specimen containing non-persistent joints under confining pressure with the bondedparticle model. The microscopic parameters which can reflect the macroscopic mechanical properties and failure behavior of artificial jointed specimens are firstly calibrated. Then, the influence of joint inclination and confining pressure on stress-strain curves, crack patterns, and contact force distributions of jointed rock are investigated. The simulation results show that both the compressive strength and elastic modulus of the specimens increase with increasing confining pressure, and these two mechanical parameters decrease first and then increase with the increase of joints inclination. The sensitivity of strength and elastic modulus to confining pressure is not the same in different joints inclinations, which has the least impact on specimens with α=90°. Under low confining pressure, the failure modes are controlled by the joint inclination. As the confining pressure increased, the initiation and propagation of tensile crack are gradually inhibited, and the failure mode is transferred from tensile failure to shear-compression failure. Finally, the reinforcement effect of prestressed bolt support on engineering fractured rock mass is discussed.展开更多
目的:分析BRAF^(V600E)和RAS基因突变在甲状腺乳头状癌(PTC)中的发生情况,研究BRAF^(V600E)和RAS基因突变与PTC各临床病理特征及预后的相关性。方法:通过cBioPortal网站下载整理癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中PT...目的:分析BRAF^(V600E)和RAS基因突变在甲状腺乳头状癌(PTC)中的发生情况,研究BRAF^(V600E)和RAS基因突变与PTC各临床病理特征及预后的相关性。方法:通过cBioPortal网站下载整理癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中PTC的相关信息,选取资料完善的402例PTC样本的基因突变和临床信息进行分析。先单因素分析BRAF^(V600E)和RAS基因突变与临床病理参数的相关性,再对其进行多因素Logistic回归分析。结果:在402例PTC中,BRAF^(V600E)的突变率为48.5%(195/402),RAS基因突变率为10.2%(41/402)。单因素分析显示BRAF^(V600E)突变与患者的年龄、性别无关(P>0.05),与有无淋巴结转移、有无腺外侵犯、分期、复发进展和病理亚型有关(P<0.05);RAS基因突变与患者年龄、性别、分期、复发进展无关(P>0.05),与有无淋巴结转移、有无腺外侵犯和病理亚型有关(P <0.05)。Logistics回归分析显示BRAF^(V600E)基因突变与有无腺外侵犯和PTC的病理亚型有关(P<0.05),RAS基因突变与有无淋巴结转移、有无腺外侵犯和PTC病理亚型有关(P<0.05)。结论:在PTC中,BRAF^(V600E)基因突变率显著高于RAS基因突变率;BRAF^(V600E)和RAS基因突变可作为PTC患者预后的预测因素。展开更多
基金Projects(52004145,51904164)supported by the National Natural Science Foundation of ChinaProject(ZR2020QE119)supported by the Natural Science Foundation of Shandong Province,ChinaProject(SICGM202107)supported by the Open Fund of the Key Laboratory of Mining Disaster Prevention and Control,China。
文摘For a deeper understanding of the deformation failure behavior of jointed rock, numerical compression simulations are carried out on a rock specimen containing non-persistent joints under confining pressure with the bondedparticle model. The microscopic parameters which can reflect the macroscopic mechanical properties and failure behavior of artificial jointed specimens are firstly calibrated. Then, the influence of joint inclination and confining pressure on stress-strain curves, crack patterns, and contact force distributions of jointed rock are investigated. The simulation results show that both the compressive strength and elastic modulus of the specimens increase with increasing confining pressure, and these two mechanical parameters decrease first and then increase with the increase of joints inclination. The sensitivity of strength and elastic modulus to confining pressure is not the same in different joints inclinations, which has the least impact on specimens with α=90°. Under low confining pressure, the failure modes are controlled by the joint inclination. As the confining pressure increased, the initiation and propagation of tensile crack are gradually inhibited, and the failure mode is transferred from tensile failure to shear-compression failure. Finally, the reinforcement effect of prestressed bolt support on engineering fractured rock mass is discussed.
文摘目的:分析BRAF^(V600E)和RAS基因突变在甲状腺乳头状癌(PTC)中的发生情况,研究BRAF^(V600E)和RAS基因突变与PTC各临床病理特征及预后的相关性。方法:通过cBioPortal网站下载整理癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中PTC的相关信息,选取资料完善的402例PTC样本的基因突变和临床信息进行分析。先单因素分析BRAF^(V600E)和RAS基因突变与临床病理参数的相关性,再对其进行多因素Logistic回归分析。结果:在402例PTC中,BRAF^(V600E)的突变率为48.5%(195/402),RAS基因突变率为10.2%(41/402)。单因素分析显示BRAF^(V600E)突变与患者的年龄、性别无关(P>0.05),与有无淋巴结转移、有无腺外侵犯、分期、复发进展和病理亚型有关(P<0.05);RAS基因突变与患者年龄、性别、分期、复发进展无关(P>0.05),与有无淋巴结转移、有无腺外侵犯和病理亚型有关(P <0.05)。Logistics回归分析显示BRAF^(V600E)基因突变与有无腺外侵犯和PTC的病理亚型有关(P<0.05),RAS基因突变与有无淋巴结转移、有无腺外侵犯和PTC病理亚型有关(P<0.05)。结论:在PTC中,BRAF^(V600E)基因突变率显著高于RAS基因突变率;BRAF^(V600E)和RAS基因突变可作为PTC患者预后的预测因素。
