Background and Study Aims: The development of anastomotic strictures is one of the most common complications of orthotopic liver transplantation (OLT) with choledochocholedochostomy anastomosis. Endoscopic therapy wit...Background and Study Aims: The development of anastomotic strictures is one of the most common complications of orthotopic liver transplantation (OLT) with choledochocholedochostomy anastomosis. Endoscopic therapy with balloon dilation and/or stent placement is an effective therapy. The aim of this study was to assess the recurrence rate of anastomotic strictures and the features that predict recurrence after previously successful endoscopic therapy. Patients and Methods: We searched the endoscopic retrograde cholangiopancreatography (ERCP) database for all patients who had had an OLT who were undergoing ERCP. The study cohort consisted of post-OLT patients who had a recurrence of anastomotic stricture after initial resolution following a course of endoscopic therapy. Results: A total of 916 OLT operations were performed during the study period from June 1994 to November 2004. Out of this group, 143 patients (15.6%) were diagnosed with anastomotic stricture and underwent a total of 423 ERCPs for endoscopic treatment. Twelve patients who are still undergoing endoscopic therapy were excluded from the analysis. The technical success rate was 96.6%, and the endoscopic therapy was successful in 82%of patients; 18%had a recurrence of cholestasis and ERCP revealed a recurrence of the anastomotic stricture that required intervention. Themean time of follow-up after stent removal was 28 months (range 1-114 months). The study did not reveal any clinical or endoscopic parameters that could predict recurrence, though the presence of a biliary leak at initial ERCP and a longer time to initial presentation were factors that showed a trend toward an increased likelihood of recurrence. Conclusions: Biliary strictures remain a common complication after OLT, and in nearly one in five patients these strictures recur after initially successful endoscopic therapy. There were no clinical or endoscopic parameters identified in this study that predicted recurrence. Further study is needed to determine what type of endoscopic therapy would minimize the risk of stricture recurrence.展开更多
Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W s...Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W states as quantum channels,while the second replaces the symmetric W state by an asymmetric one.Both schemes are treated and compared from the aspects of quantum resource consumption,operation complexity,classical resource consumption,success probability and efficiency.It is found that the latter scheme is better than the former one.Particularly,the sharing can be achieved only probabilistically with the first scheme deterministically with the second one.展开更多
Small reactors have become a new hotspot of international nuclear energy research.The nuclear heating reactor(NHR)technology developed by Tsinghua University is an important multipurpose small reactor solution with fe...Small reactors have become a new hotspot of international nuclear energy research.The nuclear heating reactor(NHR)technology developed by Tsinghua University is an important multipurpose small reactor solution with features such as high integration,modular design and full power natural circulation.A new small reactor based on the existing NHR-200 reactor was developed by the Institute of Nuclear and New Energy Technology of Tsinghua University.A full-scale natural circulation test loop with the same operating parameters as the actual reactor was built in order to experimentally validate the natural circulation ability of the reactor primary loop and heat-transfer ability of fuel assemblies and heat exchangers.Corresponding results are given in detail,including parameter validation of the reactor primary loop,flow rules of the natural circulation and heat-transfer coefficients of heaters and heat exchangers,which can be directly used in the actual reactor as a reference for optimization design.Finally,a characteristic parameter k is proposed to represent the natural circulation ability of a system.By using the new data arrangement method in the form of parameter k,comprehensive experimental results of the natural circulation can be represented by a simple integrated expression.The work in this paper is of importance in broadening application fields and pushing forward commercialization of the NHR type reactors.展开更多
文摘Background and Study Aims: The development of anastomotic strictures is one of the most common complications of orthotopic liver transplantation (OLT) with choledochocholedochostomy anastomosis. Endoscopic therapy with balloon dilation and/or stent placement is an effective therapy. The aim of this study was to assess the recurrence rate of anastomotic strictures and the features that predict recurrence after previously successful endoscopic therapy. Patients and Methods: We searched the endoscopic retrograde cholangiopancreatography (ERCP) database for all patients who had had an OLT who were undergoing ERCP. The study cohort consisted of post-OLT patients who had a recurrence of anastomotic stricture after initial resolution following a course of endoscopic therapy. Results: A total of 916 OLT operations were performed during the study period from June 1994 to November 2004. Out of this group, 143 patients (15.6%) were diagnosed with anastomotic stricture and underwent a total of 423 ERCPs for endoscopic treatment. Twelve patients who are still undergoing endoscopic therapy were excluded from the analysis. The technical success rate was 96.6%, and the endoscopic therapy was successful in 82%of patients; 18%had a recurrence of cholestasis and ERCP revealed a recurrence of the anastomotic stricture that required intervention. Themean time of follow-up after stent removal was 28 months (range 1-114 months). The study did not reveal any clinical or endoscopic parameters that could predict recurrence, though the presence of a biliary leak at initial ERCP and a longer time to initial presentation were factors that showed a trend toward an increased likelihood of recurrence. Conclusions: Biliary strictures remain a common complication after OLT, and in nearly one in five patients these strictures recur after initially successful endoscopic therapy. There were no clinical or endoscopic parameters identified in this study that predicted recurrence. Further study is needed to determine what type of endoscopic therapy would minimize the risk of stricture recurrence.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20103401110007National Natural Science Foundation of China under Grant Nos.10874122,10975001,51072002,and 51272003+1 种基金the Program for Excellent Talents at the University of Guangdong Province(Guangdong Teacher Letter[1010]No.79)the 211 Project of Anhui University
文摘Two tripartite schemes are put forward with shared entanglements and Local Operation and Classical Communication (LOCC) for sharing an operation on a remote target sate.The first scheme uses a Bell and a symmetric W states as quantum channels,while the second replaces the symmetric W state by an asymmetric one.Both schemes are treated and compared from the aspects of quantum resource consumption,operation complexity,classical resource consumption,success probability and efficiency.It is found that the latter scheme is better than the former one.Particularly,the sharing can be achieved only probabilistically with the first scheme deterministically with the second one.
基金supported by the National S&T Major Project(Grant No.ZX06901)the National Natural Science Foundation of China(Grant No.11072131)
文摘Small reactors have become a new hotspot of international nuclear energy research.The nuclear heating reactor(NHR)technology developed by Tsinghua University is an important multipurpose small reactor solution with features such as high integration,modular design and full power natural circulation.A new small reactor based on the existing NHR-200 reactor was developed by the Institute of Nuclear and New Energy Technology of Tsinghua University.A full-scale natural circulation test loop with the same operating parameters as the actual reactor was built in order to experimentally validate the natural circulation ability of the reactor primary loop and heat-transfer ability of fuel assemblies and heat exchangers.Corresponding results are given in detail,including parameter validation of the reactor primary loop,flow rules of the natural circulation and heat-transfer coefficients of heaters and heat exchangers,which can be directly used in the actual reactor as a reference for optimization design.Finally,a characteristic parameter k is proposed to represent the natural circulation ability of a system.By using the new data arrangement method in the form of parameter k,comprehensive experimental results of the natural circulation can be represented by a simple integrated expression.The work in this paper is of importance in broadening application fields and pushing forward commercialization of the NHR type reactors.
