Objective：Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer.The purpose of this study was to identify the common and characteristic...Objective：Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer.The purpose of this study was to identify the common and characteristic preoperative ultrasonography features that are associated with the pathologic extranodal extension of metastatic papillary thyroid carcinoma.Methods：We retrospectively assessed and compared clinicopathologic and ultrasound features between 60 papillary thyroid cancer patients with extranodal extension and 120 control patients with papillary thyroid cancer without extranodal extension.Results：With respect to the pathological N stage and clinicopathologic features,N1b stage papillary thyroid carcinomas were more frequently found in patients who were extranodal extension-positive,in comparison with those who were extranodal extension-negative（78.3%vs.63.3%,P=0.043）.Extranodal extension was detected most frequently in level VI cervical lymph nodes（48.7%）.In our univariate analysis of patients with papillary thyroid carcinoma,cervical lymph nodes with extranodal extension showed higher incidences of node matting,microcalcification,cystic area,aspect ratio＆lt;2,and larger diameter than those without extranodal extension（all P〈0.05）.Our multivariate analysis demonstrated that node matting and cystic area were independent risk factors for the presence of extranodal extension[odds ratio（OR）：4.751,95%confidence interval（CI）：1.212~18.626,P=0.025;OR：2.707,95%CI：1.127~6.502,P=0.026].Conclusions：Common ultrasound features may indicate the presence of extranodal extension in patients with metastatic cervical lymph nodes of papillary thyroid carcinoma.展开更多
The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding r...The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding rock was excavated. Our simula-tion results show that there are two kinds of dominating factors affecting roadway stability at points of intersection, one is the angle between horizontal stress and axial direction of the roadway and the other are the angles at the points of intersection. These results are based on a study we carried out as follows: first, we analyzed the failure mechanism of a large span intersection and then we built a mechanical model of a rock pillar at one of the points of intersection. At the end of this analysis, we obtained the failure characteristics of the critical parts on the large span intersection. Given these failure characteristics, we proposed a new supporting method, i.e., a Double-Bolt Control Technology (DBCT). By way of numerical simulation, DBCT can effectively control the deformation of the surrounding rock at the points of intersection in roadways.展开更多
Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,...Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,seriously affecting the in-tegrity and stability of roofs,leading to incidents of roof fall.Control of water-enriched rocks surrounding coal drifts is quite diffi-cult in China.Based on the practical situation of a water-enriched roof of a coal drift in working face 112201 of the Meihuajing coal mine,we studied the deformation features of surrounding rocks and the development of fractured areas and analyzed the major reasons for the decrease in load-carrying capacity,indicating that the key to maintain roof stability of this kind of coal drift is water retention.In addition,we proposed a staged control technology consisting of:1) surface grouting;2) cable anchor strengthening and 3) roof grouting,which has proven to be successful in this practical application.Our study indicates that,after the problem of water loss from the water-enriched roof had been effectively solved,a combined support system with high performance bolts can maintain the stability of the bearing structure,resulting in the control of roof stability in this kind of coal drift.展开更多
文摘Objective：Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer.The purpose of this study was to identify the common and characteristic preoperative ultrasonography features that are associated with the pathologic extranodal extension of metastatic papillary thyroid carcinoma.Methods：We retrospectively assessed and compared clinicopathologic and ultrasound features between 60 papillary thyroid cancer patients with extranodal extension and 120 control patients with papillary thyroid cancer without extranodal extension.Results：With respect to the pathological N stage and clinicopathologic features,N1b stage papillary thyroid carcinomas were more frequently found in patients who were extranodal extension-positive,in comparison with those who were extranodal extension-negative（78.3%vs.63.3%,P=0.043）.Extranodal extension was detected most frequently in level VI cervical lymph nodes（48.7%）.In our univariate analysis of patients with papillary thyroid carcinoma,cervical lymph nodes with extranodal extension showed higher incidences of node matting,microcalcification,cystic area,aspect ratio＆lt;2,and larger diameter than those without extranodal extension（all P〈0.05）.Our multivariate analysis demonstrated that node matting and cystic area were independent risk factors for the presence of extranodal extension[odds ratio（OR）：4.751,95%confidence interval（CI）：1.212~18.626,P=0.025;OR：2.707,95%CI：1.127~6.502,P=0.026].Conclusions：Common ultrasound features may indicate the presence of extranodal extension in patients with metastatic cervical lymph nodes of papillary thyroid carcinoma.
基金Financial supports for this work, provided by the Major Program of the National Natural Science Foundation of China (No.50490270)the National Basic Research Program of China (973) (No. 2006CB202200) the Innovation Term Project of Ministry of Education of China (No.IRT0656), are gratefully acknowledged
文摘The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding rock was excavated. Our simula-tion results show that there are two kinds of dominating factors affecting roadway stability at points of intersection, one is the angle between horizontal stress and axial direction of the roadway and the other are the angles at the points of intersection. These results are based on a study we carried out as follows: first, we analyzed the failure mechanism of a large span intersection and then we built a mechanical model of a rock pillar at one of the points of intersection. At the end of this analysis, we obtained the failure characteristics of the critical parts on the large span intersection. Given these failure characteristics, we proposed a new supporting method, i.e., a Double-Bolt Control Technology (DBCT). By way of numerical simulation, DBCT can effectively control the deformation of the surrounding rock at the points of intersection in roadways.
基金Projects 50674085 supported by the Qing Lan Project of Jiangsu Provicne50774077 by the National Natural Science Foundation of China
文摘Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,seriously affecting the in-tegrity and stability of roofs,leading to incidents of roof fall.Control of water-enriched rocks surrounding coal drifts is quite diffi-cult in China.Based on the practical situation of a water-enriched roof of a coal drift in working face 112201 of the Meihuajing coal mine,we studied the deformation features of surrounding rocks and the development of fractured areas and analyzed the major reasons for the decrease in load-carrying capacity,indicating that the key to maintain roof stability of this kind of coal drift is water retention.In addition,we proposed a staged control technology consisting of:1) surface grouting;2) cable anchor strengthening and 3) roof grouting,which has proven to be successful in this practical application.Our study indicates that,after the problem of water loss from the water-enriched roof had been effectively solved,a combined support system with high performance bolts can maintain the stability of the bearing structure,resulting in the control of roof stability in this kind of coal drift.
