Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneousl...Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneously support the single-mode propagation of both a pump wave(1550 nm)and a second harmonic wave(775 nm).As a result of the strong confinement and intensive nonlinear effect in the PPLNOI rib waveguide,the calculated results indicate that a second-harmonic generation conversion efficiency of 400%W^(-1)·cm^(-2) can be achieved at a wavelength of 1550 nm,almost 2.6 times higher than the widely applied reverse proton-exchanged waveguide(150%W^(-1)·cm^(-2)).展开更多
Background Percutaneous coronary intervention （PCI） is a well-established method for managing coronary diseases. However, the increasing use of PCI has led to an increased incidence of acute cerebrovascular acciden...Background Percutaneous coronary intervention （PCI） is a well-established method for managing coronary diseases. However, the increasing use of PCI has led to an increased incidence of acute cerebrovascular accidents （CVA） related to PCI. In this study, we investigated the characteristics and risk factors of CVA after PCI in patients with known stroke history. Methods Between January 1, 2005 and March 1, 2009, 621 patients with a history of stroke underwent a total of 665 PCI procedures and were included in this retrospective study. Demographic and clinical characteristics, previous medications, procedures, neurologic deficits, location of lesion and in-hospital clinical outcomes of patients who developed a CVA after the cardiac catheterization laboratory visit and before discharge were reviewed. Results Acute CVA was diagnosed in 53 （8.5%） patients during the operation or the perioperative period. Seventeen patients suffered from transient ischemic attack, thirty-four patients suffered from cerebral infarction and two patients suffered from cerebral hemorrhage. The risk factors for CVA after PCI in stroke patients were： admission with an acute coronary syndrome, use of an intra-aortic balloon pump, urgent or emergency procedures, diabetes mellitus, and poor left ventricular systolic function, arterial fibrillation, previous myocardial infarction, dyslipidemia, tobacco use, and no/irregular use of anti-platelet medications. Conclusions The incidence of CVA during and after PCI in patients with history of stroke is much higher than that in patients without history of stroke. Patients with atrial fibrillation, previous myocardial infarction, diabetes mellitus, dyslipidemia, tobacco use, and no or irregular use of anti-platelet medications were at higher risk for recurrent stroke. This study showed a strong association between acute coronary svndromes and in-hospital stroke after PCI.展开更多
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2009AA03Z410。
文摘Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneously support the single-mode propagation of both a pump wave(1550 nm)and a second harmonic wave(775 nm).As a result of the strong confinement and intensive nonlinear effect in the PPLNOI rib waveguide,the calculated results indicate that a second-harmonic generation conversion efficiency of 400%W^(-1)·cm^(-2) can be achieved at a wavelength of 1550 nm,almost 2.6 times higher than the widely applied reverse proton-exchanged waveguide(150%W^(-1)·cm^(-2)).
文摘Background Percutaneous coronary intervention （PCI） is a well-established method for managing coronary diseases. However, the increasing use of PCI has led to an increased incidence of acute cerebrovascular accidents （CVA） related to PCI. In this study, we investigated the characteristics and risk factors of CVA after PCI in patients with known stroke history. Methods Between January 1, 2005 and March 1, 2009, 621 patients with a history of stroke underwent a total of 665 PCI procedures and were included in this retrospective study. Demographic and clinical characteristics, previous medications, procedures, neurologic deficits, location of lesion and in-hospital clinical outcomes of patients who developed a CVA after the cardiac catheterization laboratory visit and before discharge were reviewed. Results Acute CVA was diagnosed in 53 （8.5%） patients during the operation or the perioperative period. Seventeen patients suffered from transient ischemic attack, thirty-four patients suffered from cerebral infarction and two patients suffered from cerebral hemorrhage. The risk factors for CVA after PCI in stroke patients were： admission with an acute coronary syndrome, use of an intra-aortic balloon pump, urgent or emergency procedures, diabetes mellitus, and poor left ventricular systolic function, arterial fibrillation, previous myocardial infarction, dyslipidemia, tobacco use, and no/irregular use of anti-platelet medications. Conclusions The incidence of CVA during and after PCI in patients with history of stroke is much higher than that in patients without history of stroke. Patients with atrial fibrillation, previous myocardial infarction, diabetes mellitus, dyslipidemia, tobacco use, and no or irregular use of anti-platelet medications were at higher risk for recurrent stroke. This study showed a strong association between acute coronary svndromes and in-hospital stroke after PCI.
