Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous...Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous carcinoma,in which at least 50%of the tumor is composed of large pools of extracellular mucin and columns of malignant cells,is associated with a worse prognosis.Signet ring cell carcinoma is characterized by large intracytoplasmic mucin vacuoles that expand in the malignant cells with the nucleus displaced to the periphery.Its prognosis is also generally poor.In contrast,intraductal papillary mucinous neoplasm of the bile duct and pancreas,which is characterized by proliferation of ductal epithelium and variable mucin production,has a better prognosis than other malignancies in the pancreaticobiliary tree.Imaging modalities play a critical role in differentiating mucinous from non-mucinous neoplasms.Due to high water content,mucin has a similar appearance to water on ultrasound(US) ,computed tomography(CT) ,and magnetic resonance imaging,except when thick and proteinaceous,and then it tends to be hypoechoic with fine internal echoes or have complex echogenicity on US,hyperdense on CT,and hyperintense on T1and hypointense on T2-weighted images,compared to water.Therefore,knowledge of characteristic mucin imaging features is helpful to diagnose various mucinproducing neoplastic conditions and to facilitate appropriate treatment.展开更多
Segmentation of the thrust fault zone is a basic problem for earthquake hazard evaluation. The Yingjing-Mabian-Yanjin thrust fault zone is an important seismic belt NW-trending in the southeast margin of the Qinghal-X...Segmentation of the thrust fault zone is a basic problem for earthquake hazard evaluation. The Yingjing-Mabian-Yanjin thrust fault zone is an important seismic belt NW-trending in the southeast margin of the Qinghal-Xizang （Tibet） plateau. The longitudinal faults in the thrust zone are mainly of the thrust slipping type. The late Quaternary motion modes and displacement rates are quite different from north to south. Investigation on valleys across the fault shows that the transverse faults are mainly of dextral strike-slipping type with a bit dip displacement. Based on their connections with the longitudinal faults, three types of transverse faults are generalized, namely： the separate fault, the transform fault and the tear fault, and their functions in the segmentation of the thrust fault zone are compared. As the result, the Yingjing-Mabian-Yanjin thrust fault zone is divided into three segments, and earthquakes occurring in these three segments are compared. The tri-section of the Yingjing-Mabian-Yanjin thrust fault zone identified by transverse fault types reflects, on the one hand, the differences in slip rate, earthquake magnitude and pace from each segment, and the coherence of earthquake rupturing pace on the other hand. It demonstrates that the transverse faults control the segmentation to a certain degree, and each type of the transverse faults plays a different role.展开更多
基金Supported by A grant from the Korea Healthcare Technology R and D Project,Ministry for Health,Welfare,and Family Affairs,South Korea,A091047
文摘Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous carcinoma,in which at least 50%of the tumor is composed of large pools of extracellular mucin and columns of malignant cells,is associated with a worse prognosis.Signet ring cell carcinoma is characterized by large intracytoplasmic mucin vacuoles that expand in the malignant cells with the nucleus displaced to the periphery.Its prognosis is also generally poor.In contrast,intraductal papillary mucinous neoplasm of the bile duct and pancreas,which is characterized by proliferation of ductal epithelium and variable mucin production,has a better prognosis than other malignancies in the pancreaticobiliary tree.Imaging modalities play a critical role in differentiating mucinous from non-mucinous neoplasms.Due to high water content,mucin has a similar appearance to water on ultrasound(US) ,computed tomography(CT) ,and magnetic resonance imaging,except when thick and proteinaceous,and then it tends to be hypoechoic with fine internal echoes or have complex echogenicity on US,hyperdense on CT,and hyperintense on T1and hypointense on T2-weighted images,compared to water.Therefore,knowledge of characteristic mucin imaging features is helpful to diagnose various mucinproducing neoplastic conditions and to facilitate appropriate treatment.
基金The research was sponsored bythe keyresearch project entitled"Seismic Safety Evaluation and Structural Earthquake Resistance"under the 10th Five-Year Program of the ChinaEarthquake Administration the Joint Earthquake Science Foundation of China (0101302) Contribution number :2005A001 ,the Institute of Crustal Dynamics ,CEA.
文摘Segmentation of the thrust fault zone is a basic problem for earthquake hazard evaluation. The Yingjing-Mabian-Yanjin thrust fault zone is an important seismic belt NW-trending in the southeast margin of the Qinghal-Xizang （Tibet） plateau. The longitudinal faults in the thrust zone are mainly of the thrust slipping type. The late Quaternary motion modes and displacement rates are quite different from north to south. Investigation on valleys across the fault shows that the transverse faults are mainly of dextral strike-slipping type with a bit dip displacement. Based on their connections with the longitudinal faults, three types of transverse faults are generalized, namely： the separate fault, the transform fault and the tear fault, and their functions in the segmentation of the thrust fault zone are compared. As the result, the Yingjing-Mabian-Yanjin thrust fault zone is divided into three segments, and earthquakes occurring in these three segments are compared. The tri-section of the Yingjing-Mabian-Yanjin thrust fault zone identified by transverse fault types reflects, on the one hand, the differences in slip rate, earthquake magnitude and pace from each segment, and the coherence of earthquake rupturing pace on the other hand. It demonstrates that the transverse faults control the segmentation to a certain degree, and each type of the transverse faults plays a different role.
