AIM To evaluate the changes in the 8^(th) edition American Joint Committee on Cancer(AJCC) for defining stage?ⅠB and?ⅡA pancreatic cancer and identify their prognostic factors.METHODS Pancreatic cancer patients were...AIM To evaluate the changes in the 8^(th) edition American Joint Committee on Cancer(AJCC) for defining stage?ⅠB and?ⅡA pancreatic cancer and identify their prognostic factors.METHODS Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database(1973-2013). The enrolled patients were divided into?ⅠB and?ⅡA groups based on tumor size according to the 8^(th) edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the?ⅠB and?ⅡA stages of pancreatic cancer under new criteria.RESULTS A total of 1349 pancreatic cancer patients were included. More patients had stage?ⅠB rather than stage?ⅡA. Stage?ⅠB tumors(54.85%) were mainly located in the head of the pancreas, while stage?ⅡA tumors were more often located in the tail and head of the pancreas(35.21% and 31.75%, respectively). The survival time of stage?ⅠB and?ⅡA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage?ⅠB and?ⅡA patients were different. for stage?ⅠB patients, age and primary site were the independent prognostic factors; for stage?ⅡA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.CONCLUSION The prognostic factors for stage?ⅠB and?ⅡA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage?ⅠB and?ⅡA patients has no significant difference.展开更多
Ultrasonic impact treatment(UIT) is a postweld technique for improving the fatigue strength of welded joints. This technique makes use of ultrasonic vibration to impact and plastically deform a weld toe and can achiev...Ultrasonic impact treatment(UIT) is a postweld technique for improving the fatigue strength of welded joints. This technique makes use of ultrasonic vibration to impact and plastically deform a weld toe and can achieve surface grain refinement of the weld toe,which is considered as the main reason for the improvement of fatigue strength. In this paper,the microstructure of the surface of a treated weld toe was observed by metallographic microscopy and transmission electron microscopy(TEM). The results show that UIT could produce severe plastic deformation on the surface layer of the weld toe and the maximum depth of plastic deformation extended to approximately 260 μm beneath the treated surface. Repeated processing could exacerbate the plastic deformation on the surface layer,resulting in finer grains. We can conclude that the surface grain refinement mechanism of SMA490 BW welded joints is related to the high density of dislocation tangles and dislocation walls.展开更多
文摘AIM To evaluate the changes in the 8^(th) edition American Joint Committee on Cancer(AJCC) for defining stage?ⅠB and?ⅡA pancreatic cancer and identify their prognostic factors.METHODS Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database(1973-2013). The enrolled patients were divided into?ⅠB and?ⅡA groups based on tumor size according to the 8^(th) edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the?ⅠB and?ⅡA stages of pancreatic cancer under new criteria.RESULTS A total of 1349 pancreatic cancer patients were included. More patients had stage?ⅠB rather than stage?ⅡA. Stage?ⅠB tumors(54.85%) were mainly located in the head of the pancreas, while stage?ⅡA tumors were more often located in the tail and head of the pancreas(35.21% and 31.75%, respectively). The survival time of stage?ⅠB and?ⅡA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage?ⅠB and?ⅡA patients were different. for stage?ⅠB patients, age and primary site were the independent prognostic factors; for stage?ⅡA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.CONCLUSION The prognostic factors for stage?ⅠB and?ⅡA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage?ⅠB and?ⅡA patients has no significant difference.
基金the National Natural Science Foundation of China(Nos.51675414,51805416)the Joint Fund for Aerospace Advanced Manufacturing Technology Research Key Program,China(No.U1937203).
基金financially supported by the National Natural Science Foundation of China(No.51365014)the Industrial Support Key Project of Jiangxi Province,China(No.20161BBE50072)
文摘Ultrasonic impact treatment(UIT) is a postweld technique for improving the fatigue strength of welded joints. This technique makes use of ultrasonic vibration to impact and plastically deform a weld toe and can achieve surface grain refinement of the weld toe,which is considered as the main reason for the improvement of fatigue strength. In this paper,the microstructure of the surface of a treated weld toe was observed by metallographic microscopy and transmission electron microscopy(TEM). The results show that UIT could produce severe plastic deformation on the surface layer of the weld toe and the maximum depth of plastic deformation extended to approximately 260 μm beneath the treated surface. Repeated processing could exacerbate the plastic deformation on the surface layer,resulting in finer grains. We can conclude that the surface grain refinement mechanism of SMA490 BW welded joints is related to the high density of dislocation tangles and dislocation walls.
