Pulse dynamics and stability in optical fibers in the presence of both self-steepening and quintic nonlinear effects are analyzed. Propagating profiles of the quintic derivative nonlinear Schr¨odinger model are i...Pulse dynamics and stability in optical fibers in the presence of both self-steepening and quintic nonlinear effects are analyzed. Propagating profiles of the quintic derivative nonlinear Schr¨odinger model are isolated via two invariants of motion. The resulting canonical equation admits exact periodic propagating patterns in terms of the Jacobi elliptic functions, and solitary pulses are recovered in the long wave limit, i.e. degenerate cases of periodic profiles where each pulse is widely separated from the adjacent ones. Two families of such exact wave profiles are identified. The first one has a precise constraint concerning the magnitude of self-steepening and quintic nonlinear effects, while the second one permits more freedom. The reduction to the well established temporal soliton in an optical fiber waveguide in the absence of self-steepening and quintic nonlinearity is demonstrated explicitly. Numerical simulations are performed to identify regimes of parameter values where robust propagation patterns exist.展开更多
Aims: Although embolic protection devices reduce complications during saphenous vein graft(SVG) stenting, adverse events still occur in ～10%of patients. IIb/IIIa antagonists have not been proven effective during SVG ...Aims: Although embolic protection devices reduce complications during saphenous vein graft(SVG) stenting, adverse events still occur in ～10%of patients. IIb/IIIa antagonists have not been proven effective during SVG intervention. We hypothesized that adjunctive use of these agents might enhance the efficacy of embolic protection devices. Methods and results: In the prospective, multicentre FilterWire EX Randomized Evaluation trial, 651 patients undergoing SVG stenting were randomized to either filter-based FilterWire EX or balloon occlusion/aspiration GuardWire embolic protection devices. IIb/IIIa inhibitor use was at the discretion of the investigator, with randomization stratified by intended use. Patients pre-selected for IIb/IIIa inhibitor use(n=345) had higher baseline risk, with increased 30-day major adverse cardiac events(MACE, 13.0 vs. 8.0%, P=0.03). GuardWire assigned patients treated with IIb/IIIa inhibitors had higher 30-day MACE compared with those not treated with IIb/IIIa inhibitors(16.0 vs. 6.3%, P=0.007). In contrast, MACE in high-risk FilterWire patients treated with IIb/IIIa inhibitors were similar to their lower risk, untreated counterparts(9.9 vs. 9.5%, P=0.89). Multivariable analysis detected a borderline significant(P=0.056) interaction for lower MACE between FilterWire and IIb/ IIIa inhibitor use. Adjustment by the propensity to use IIb/IIIa inhibitors resulted in a significant(P=0.023) interaction for lower MACE rates. IIb/IIIa inhibition in conjunction with FilterWire was associated with less abrupt closure, no reflow, or distal embolization. Conclusion: IIb/IIIa antagonists may improve procedural outcome during SVG stenting in high risk patients, utilizing filter-based embolic protection devices.展开更多
基金Support for this project has been provided by the Research Grants Council General Research Fund contract HKU 711713E
文摘Pulse dynamics and stability in optical fibers in the presence of both self-steepening and quintic nonlinear effects are analyzed. Propagating profiles of the quintic derivative nonlinear Schr¨odinger model are isolated via two invariants of motion. The resulting canonical equation admits exact periodic propagating patterns in terms of the Jacobi elliptic functions, and solitary pulses are recovered in the long wave limit, i.e. degenerate cases of periodic profiles where each pulse is widely separated from the adjacent ones. Two families of such exact wave profiles are identified. The first one has a precise constraint concerning the magnitude of self-steepening and quintic nonlinear effects, while the second one permits more freedom. The reduction to the well established temporal soliton in an optical fiber waveguide in the absence of self-steepening and quintic nonlinearity is demonstrated explicitly. Numerical simulations are performed to identify regimes of parameter values where robust propagation patterns exist.
文摘Aims: Although embolic protection devices reduce complications during saphenous vein graft(SVG) stenting, adverse events still occur in ～10%of patients. IIb/IIIa antagonists have not been proven effective during SVG intervention. We hypothesized that adjunctive use of these agents might enhance the efficacy of embolic protection devices. Methods and results: In the prospective, multicentre FilterWire EX Randomized Evaluation trial, 651 patients undergoing SVG stenting were randomized to either filter-based FilterWire EX or balloon occlusion/aspiration GuardWire embolic protection devices. IIb/IIIa inhibitor use was at the discretion of the investigator, with randomization stratified by intended use. Patients pre-selected for IIb/IIIa inhibitor use(n=345) had higher baseline risk, with increased 30-day major adverse cardiac events(MACE, 13.0 vs. 8.0%, P=0.03). GuardWire assigned patients treated with IIb/IIIa inhibitors had higher 30-day MACE compared with those not treated with IIb/IIIa inhibitors(16.0 vs. 6.3%, P=0.007). In contrast, MACE in high-risk FilterWire patients treated with IIb/IIIa inhibitors were similar to their lower risk, untreated counterparts(9.9 vs. 9.5%, P=0.89). Multivariable analysis detected a borderline significant(P=0.056) interaction for lower MACE between FilterWire and IIb/ IIIa inhibitor use. Adjustment by the propensity to use IIb/IIIa inhibitors resulted in a significant(P=0.023) interaction for lower MACE rates. IIb/IIIa inhibition in conjunction with FilterWire was associated with less abrupt closure, no reflow, or distal embolization. Conclusion: IIb/IIIa antagonists may improve procedural outcome during SVG stenting in high risk patients, utilizing filter-based embolic protection devices.
