Active set method and gradient projection method are curre nt ly the main approaches for linearly constrained convex programming. Interior-po int method is one of the most effective choices for linear programming. In ...Active set method and gradient projection method are curre nt ly the main approaches for linearly constrained convex programming. Interior-po int method is one of the most effective choices for linear programming. In the p aper a predictor-corrector interior-point algorithm for linearly constrained c onvex programming under the predictor-corrector motivation was proposed. In eac h iteration, the algorithm first performs a predictor-step to reduce the dualit y gap and then a corrector-step to keep the points close to the central traject ory. Computations in the algorithm only require that the initial iterate be nonn egative while feasibility or strict feasibility is not required. It is proved th at the algorithm is equivalent to a level-1 perturbed composite Newton method. Numerical experiments on twenty-six standard test problems are made. The result s show that the proposed algorithm is stable and robust.展开更多
Catheter ablation has been recommended as a treatment option for paroxysmal atrial fibrillation（PAF） patients complicated with type 2 diabetes mellitus（T2DM）. PAF patients with T2 DM have a higher recurrence rate ...Catheter ablation has been recommended as a treatment option for paroxysmal atrial fibrillation（PAF） patients complicated with type 2 diabetes mellitus（T2DM）. PAF patients with T2 DM have a higher recurrence rate after catheter ablation. Prolongation of corrected QT（QTc） interval has been linked to poor outcomes in T2 DM patients. Whether the abnormal QTc interval is associated with the ablation outcome in the PAF patients with T2 DM remains unknown. In this study, 134 PAF patients with T2 DM undergoing primary catheter ablation were retrospectively enrolled. Pre-procedural QTc interval was corrected by using the Bazett＇s formula. Cox proportional hazards models were constructed to assess the relationship between QTc interval and the recurrence of AF. After a 29.1-month follow-up period, 61 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had a longer QTc interval than non-recurrent patients（425.2±21.5 ms vs. 414.1±13.4 ms, P=0.002）. Multivariate Cox regression analysis revealed that QTc interval [hazard ratio（HR）=1.026, 95% confidence interval（CI） 1.012–1.040, P=0.005] and left atrial diameter（LAD）（HR=1.125, 95% CI 1.062–1.192, P=0.003） were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that the cut-off value of QTc（418 ms） predicted arrhythmia recurrence with a sensitivity of 55.7% and a specificity of 69.9%. A combination of LAD and QTc was more effective than LAD alone（P〈0.001） in predicting arrhythmia recurrence after the procedure. QTc interval could be used as an independent predictor of arrhythmia recurrence in T2 DM patients undergoing AF ablation, thus providing a simple method to identify those patients who likely have a better outcome following the procedure.展开更多
文摘Active set method and gradient projection method are curre nt ly the main approaches for linearly constrained convex programming. Interior-po int method is one of the most effective choices for linear programming. In the p aper a predictor-corrector interior-point algorithm for linearly constrained c onvex programming under the predictor-corrector motivation was proposed. In eac h iteration, the algorithm first performs a predictor-step to reduce the dualit y gap and then a corrector-step to keep the points close to the central traject ory. Computations in the algorithm only require that the initial iterate be nonn egative while feasibility or strict feasibility is not required. It is proved th at the algorithm is equivalent to a level-1 perturbed composite Newton method. Numerical experiments on twenty-six standard test problems are made. The result s show that the proposed algorithm is stable and robust.
基金supported by grants from the Ministry of Science and Technology of the People’s Republic of China(No.2013BAI09B02 and No.2013DFB30310)Beijing Municipal Commission of Science and Technology(No.D131100002-313001)the National Science Foundation Council of China(Nos.81170168,81370290,81370292 and 81470465)
文摘Catheter ablation has been recommended as a treatment option for paroxysmal atrial fibrillation（PAF） patients complicated with type 2 diabetes mellitus（T2DM）. PAF patients with T2 DM have a higher recurrence rate after catheter ablation. Prolongation of corrected QT（QTc） interval has been linked to poor outcomes in T2 DM patients. Whether the abnormal QTc interval is associated with the ablation outcome in the PAF patients with T2 DM remains unknown. In this study, 134 PAF patients with T2 DM undergoing primary catheter ablation were retrospectively enrolled. Pre-procedural QTc interval was corrected by using the Bazett＇s formula. Cox proportional hazards models were constructed to assess the relationship between QTc interval and the recurrence of AF. After a 29.1-month follow-up period, 61 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had a longer QTc interval than non-recurrent patients（425.2±21.5 ms vs. 414.1±13.4 ms, P=0.002）. Multivariate Cox regression analysis revealed that QTc interval [hazard ratio（HR）=1.026, 95% confidence interval（CI） 1.012–1.040, P=0.005] and left atrial diameter（LAD）（HR=1.125, 95% CI 1.062–1.192, P=0.003） were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that the cut-off value of QTc（418 ms） predicted arrhythmia recurrence with a sensitivity of 55.7% and a specificity of 69.9%. A combination of LAD and QTc was more effective than LAD alone（P〈0.001） in predicting arrhythmia recurrence after the procedure. QTc interval could be used as an independent predictor of arrhythmia recurrence in T2 DM patients undergoing AF ablation, thus providing a simple method to identify those patients who likely have a better outcome following the procedure.
