BACKGROUND:Stent migration in the hepatopancreatic duct might arise as one of the rare complications associated with biliary or pancreatic stenting.Although there are some procedures to retrieve the migrated stent,inc...BACKGROUND:Stent migration in the hepatopancreatic duct might arise as one of the rare complications associated with biliary or pancreatic stenting.Although there are some procedures to retrieve the migrated stent,including surgical,percutaneous,and endoscopic approaches,endoscopy should be attempted first because it is least invasive.This study set out to evaluate the usefulness of endoscopic retrieval of migrated biliary and pancreatic stents.METHODS:Plastic stents that migrated in the bile duct(35 patients)or pancreatic duct(2)were retrieved with endoscopic retrograde cholangiopancreatography.Devices used were snare forceps,a basket catheter,grasping forceps,biopsy forceps,a balloon catheter,and the Soehendra stent retriever.RESULTS:Endoscopic retrieval of migrated stents was performed successfully in 36(97.0%)of the 37 patients.The devices utilized for successful treatment were basket catheter(13 patients),grasping forceps(10),snare forceps(8),balloon catheter(3),biopsy forceps(1),and the Soehendra stent retriever(1).The unsuccessfully treated patient with chronic pancreatitis underwent surgery since the guide wire did not move forward due to bile duct stenosis,and there was also duodenal stenosis.One patient developed mild pancreatitis after withdrawal of the stent;the pancreatitis was relieved with conservative treatment.CONCLUSIONS:Endoscopic retrieval of migrated biliary and pancreatic stents appears to be useful because of its safety and low invasiveness.However,various forceps should be prepared for the retrieval of a migrated stent.展开更多
A new troubleshooting algorithm for solving assignment problem based on existing algorithms is proposed, and an analysis on the related theory is given. By applying the new troubleshooting algorithm to the Lagrange re...A new troubleshooting algorithm for solving assignment problem based on existing algorithms is proposed, and an analysis on the related theory is given. By applying the new troubleshooting algorithm to the Lagrange relaxation algorithm of the multi-dimensional assignment problem of data association for multi-passive-sensor multi-target location systems, and comparing the simulation results with that of the Hungarian algorithm which is the classical optimal solving algorithm, and the multi-layer ordersearching algorithm which is a sub-optimal solving algorithm, the performance and applying conditions of the new algorithm are summarized. Theory analysis and simulation results prove the effectiveness and superiority of the new algorithm.展开更多
A digitally controlled three-dimensional gamma-scanning apparatus was developed and used to troubleshoot distillation column in the present investigation. In a 140mm(ID) model colum, various malfunctional phenomena,bo...A digitally controlled three-dimensional gamma-scanning apparatus was developed and used to troubleshoot distillation column in the present investigation. In a 140mm(ID) model colum, various malfunctional phenomena,both rate and process related conditions and structural problems, which may be frequently encountered in the operation of tray and packing columns, were experimentally simulated and tested with the developed scanning system. The experimental results showed that the scanning spectra can fairly reflect the simulated phenomena. The salient feature of the scanning apparatus lies in that it integrates the so called grid scan and computer-assisted tomography scan in a single system. It was confirmed that the gamma-scanning technique can serve as an important on-line troubleshooting and maintenance tool.展开更多
文摘BACKGROUND:Stent migration in the hepatopancreatic duct might arise as one of the rare complications associated with biliary or pancreatic stenting.Although there are some procedures to retrieve the migrated stent,including surgical,percutaneous,and endoscopic approaches,endoscopy should be attempted first because it is least invasive.This study set out to evaluate the usefulness of endoscopic retrieval of migrated biliary and pancreatic stents.METHODS:Plastic stents that migrated in the bile duct(35 patients)or pancreatic duct(2)were retrieved with endoscopic retrograde cholangiopancreatography.Devices used were snare forceps,a basket catheter,grasping forceps,biopsy forceps,a balloon catheter,and the Soehendra stent retriever.RESULTS:Endoscopic retrieval of migrated stents was performed successfully in 36(97.0%)of the 37 patients.The devices utilized for successful treatment were basket catheter(13 patients),grasping forceps(10),snare forceps(8),balloon catheter(3),biopsy forceps(1),and the Soehendra stent retriever(1).The unsuccessfully treated patient with chronic pancreatitis underwent surgery since the guide wire did not move forward due to bile duct stenosis,and there was also duodenal stenosis.One patient developed mild pancreatitis after withdrawal of the stent;the pancreatitis was relieved with conservative treatment.CONCLUSIONS:Endoscopic retrieval of migrated biliary and pancreatic stents appears to be useful because of its safety and low invasiveness.However,various forceps should be prepared for the retrieval of a migrated stent.
基金supported by the National Natural Science Foundation of China(61170161)the Natural Science Foundation of S handong (ZR2009GM002)the Technology Projects of Shandong University (J09LG01)
文摘A new troubleshooting algorithm for solving assignment problem based on existing algorithms is proposed, and an analysis on the related theory is given. By applying the new troubleshooting algorithm to the Lagrange relaxation algorithm of the multi-dimensional assignment problem of data association for multi-passive-sensor multi-target location systems, and comparing the simulation results with that of the Hungarian algorithm which is the classical optimal solving algorithm, and the multi-layer ordersearching algorithm which is a sub-optimal solving algorithm, the performance and applying conditions of the new algorithm are summarized. Theory analysis and simulation results prove the effectiveness and superiority of the new algorithm.
基金the Department of Research and Development, SINOPEC.
文摘A digitally controlled three-dimensional gamma-scanning apparatus was developed and used to troubleshoot distillation column in the present investigation. In a 140mm(ID) model colum, various malfunctional phenomena,both rate and process related conditions and structural problems, which may be frequently encountered in the operation of tray and packing columns, were experimentally simulated and tested with the developed scanning system. The experimental results showed that the scanning spectra can fairly reflect the simulated phenomena. The salient feature of the scanning apparatus lies in that it integrates the so called grid scan and computer-assisted tomography scan in a single system. It was confirmed that the gamma-scanning technique can serve as an important on-line troubleshooting and maintenance tool.
