For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of ...For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of non-invasive methods, physicians are able to study and quantify the presence of carotid atherosclerosis in vivo These procedures have enabled the introduction of new concepts: (1) the degree of carotid stenosis is approxi- mate to the volume and extension of carotid plaque; and (2) a set of parameters, easily identifiable by com- puted tomography angiography, magnetic resonance angiogram and ultra-sound echo-color Doppler, are closely linked to the development of ischemic symptoms and can significantly increase the risk of stroke regard- less of the degree of stenosis. In light of these findings vulnerable plaques should be identified early, and the role of Digital Subtraction Angiography which is a purely technical luminal technique should be determined.展开更多
High-spin states in 157Yb have been populated in the 144Sm（160, 3n）157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framewo...High-spin states in 157Yb have been populated in the 144Sm（160, 3n）157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed vf7/2 band, and the previously known vi13/2 band in 157Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157Yb provide evidence for the shape coexistence of three distinct shapes： prolate, triaxial and oblate. At higher spins, both the vf7/2 band and the vi13/2 band in 157Yb undergo a shape evolution with sizable alignments occurring.展开更多
文摘For about 50 years, angiography represented the only imaging method for studying carotid arteries in order to detect the presence of pathological stenosis due to atherosclerotic plaque. Recently, thanks to the use of non-invasive methods, physicians are able to study and quantify the presence of carotid atherosclerosis in vivo These procedures have enabled the introduction of new concepts: (1) the degree of carotid stenosis is approxi- mate to the volume and extension of carotid plaque; and (2) a set of parameters, easily identifiable by com- puted tomography angiography, magnetic resonance angiogram and ultra-sound echo-color Doppler, are closely linked to the development of ischemic symptoms and can significantly increase the risk of stroke regard- less of the degree of stenosis. In light of these findings vulnerable plaques should be identified early, and the role of Digital Subtraction Angiography which is a purely technical luminal technique should be determined.
基金supported by Natural Science Foundation of China (Nos. 10775005, 10405001, 10875002, 10735010, 10975007, 10875157, J0730316)the Chinese Major State Basic Research Development Program (No. 2007CB815002)
文摘High-spin states in 157Yb have been populated in the 144Sm（160, 3n）157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed vf7/2 band, and the previously known vi13/2 band in 157Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157Yb provide evidence for the shape coexistence of three distinct shapes： prolate, triaxial and oblate. At higher spins, both the vf7/2 band and the vi13/2 band in 157Yb undergo a shape evolution with sizable alignments occurring.
