A kind of new operators, the generalized pseudo-spin operators are introduced and a universad intrinsic Hamiltonian of two-qubit interaction is studied in terms of the generalized pseudo-spin operators. A fundamental ...A kind of new operators, the generalized pseudo-spin operators are introduced and a universad intrinsic Hamiltonian of two-qubit interaction is studied in terms of the generalized pseudo-spin operators. A fundamental quantum gate U（θ） is constructed based on the universal Hamiltonian and shown that the roles of the new quantum gate U （θ） is equivalent, functionally, to the joint operation of Hadamard and C-Not gates.展开更多
Objectives Transcatheter valve-in-valve （VIV） implantation for failed bioprostheses has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness an...Objectives Transcatheter valve-in-valve （VIV） implantation for failed bioprostheses has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness and outcomes of this emerging procedure. Methods Fourty VIV procedures were performed in 38 consecutive patients （mean age 70 ± 14 years and mean Logistic EuroScore 23.6 ± 15.5%） with severe aortic （n = 19） or mitral （n = 21） bioprosthetic valve dysfunction between 2014 and 2017. Bioprosthetic failure was secondary to stenosis in 11 （27.5%）, regurgitation in 19 （47.5%）, and combined in 10 （25.0%） bioprostheses. Clinical, echocardiographic, and procedural profiles were characterized, and the short-term results of the study patients were reported. Results Successful transfemoral （n = 15）, trans-subclavian （n = 1）, or transapical （n = 3） aortic VIV using either balloon-expandable valves （Edwards Sapien XT, n = 7） or self-expandable valves （Medtronic CoreValve, n = 12）; and transapical （n = 21） mitral VIV using either Edwards Sapien XT （n = 15） or me-chanically expandable valves （Boston Scientific Lotus, n = 6） were accomplished in all 40 VIV procedures. Implantation was successful with immediate restoration of satisfactory valve function in all patients. Five patients （13.2%） died at a median follow up of 9.3 months. Most of the 33 patients alive were in good functional status with good prosthetic valve performance. Conclusions Transcatheter VIV implantation is a feasible and safe option for the management of bioprosthetic valve failure. It may offer a less invasive alternative for those high-risk patients needing repeat valve replacement.展开更多
We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ drive...We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ driven by a classical fieM. Our concrete calculation is made for the case of two atoms for the large-detuning interaction of the atoms with the cavity mode. The main advantage of our scheme is of eliminating the photon flutuation in the cavity mode during the gating. The corresponding analytical results will be helpful for experimental realization of speed geometric quantum logical gate in real cavities.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 60472017
文摘A kind of new operators, the generalized pseudo-spin operators are introduced and a universad intrinsic Hamiltonian of two-qubit interaction is studied in terms of the generalized pseudo-spin operators. A fundamental quantum gate U（θ） is constructed based on the universal Hamiltonian and shown that the roles of the new quantum gate U （θ） is equivalent, functionally, to the joint operation of Hadamard and C-Not gates.
文摘Objectives Transcatheter valve-in-valve （VIV） implantation for failed bioprostheses has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness and outcomes of this emerging procedure. Methods Fourty VIV procedures were performed in 38 consecutive patients （mean age 70 ± 14 years and mean Logistic EuroScore 23.6 ± 15.5%） with severe aortic （n = 19） or mitral （n = 21） bioprosthetic valve dysfunction between 2014 and 2017. Bioprosthetic failure was secondary to stenosis in 11 （27.5%）, regurgitation in 19 （47.5%）, and combined in 10 （25.0%） bioprostheses. Clinical, echocardiographic, and procedural profiles were characterized, and the short-term results of the study patients were reported. Results Successful transfemoral （n = 15）, trans-subclavian （n = 1）, or transapical （n = 3） aortic VIV using either balloon-expandable valves （Edwards Sapien XT, n = 7） or self-expandable valves （Medtronic CoreValve, n = 12）; and transapical （n = 21） mitral VIV using either Edwards Sapien XT （n = 15） or me-chanically expandable valves （Boston Scientific Lotus, n = 6） were accomplished in all 40 VIV procedures. Implantation was successful with immediate restoration of satisfactory valve function in all patients. Five patients （13.2%） died at a median follow up of 9.3 months. Most of the 33 patients alive were in good functional status with good prosthetic valve performance. Conclusions Transcatheter VIV implantation is a feasible and safe option for the management of bioprosthetic valve failure. It may offer a less invasive alternative for those high-risk patients needing repeat valve replacement.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10774042,10774163,and 11074070the Natural Science Foundation of Hunan Province under Grant No.09JJ3121the Key Project of Science and Technology of Hunan Province under Grant No.2010FJ2005
文摘We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ driven by a classical fieM. Our concrete calculation is made for the case of two atoms for the large-detuning interaction of the atoms with the cavity mode. The main advantage of our scheme is of eliminating the photon flutuation in the cavity mode during the gating. The corresponding analytical results will be helpful for experimental realization of speed geometric quantum logical gate in real cavities.
