Microstructures of creep-aged 2524 （A1-4.3Cu-1.5Mg） aged at 170 ℃ with various stresses （0, 173 and 250 MPa） were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the cor...Microstructures of creep-aged 2524 （A1-4.3Cu-1.5Mg） aged at 170 ℃ with various stresses （0, 173 and 250 MPa） were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy （TEM）. The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S（Al2CuMg） phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.展开更多
Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial...Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial stiffness in human subjects, while the relationship between homocysteine and arterial stiffness in the elderly is still indefinite. The current study examined the association of homocysteine with arterial stiffness in Chinese community-based elderly persons. Methods We related serum levels of homocysteine to two measures of arte- rial stiffness （carotid-femoral pulse wave velocity （PWV） and carotid-radial PWV） in 780 participants （46.3% men, mean age 71.9 years （ranging 65-96 years old）） from two communities of Beijing, China. Arterial stiffness were measured within two days of the time of bio- marker measurement. Results In multiple-adjusted models, homocysteine levels was strongly associated with the carotid-femoral PWV （standardized 13 = 0.13, P 〈 0.001）, even after adjustment for classical risk factors of cardiovascular disease. The association is also stronger when the carotid-femoral PWV is elevated above normal, whereas no significant association with homocysteine was observed for ca-rotid-radial PWV. Conclusions In Chinese elderly persons, serum homocysteine levels are associated with alterations of aortic stiffness.展开更多
基金Project (2009BAG12A07-B02) supported by the National Science & Technology Pillar Program during the 11th Five-Year Plan Period,ChinaProject supported by Innovative Research Team in University of Liaoning Province,ChinaProject (51001022) supported by the National Natural Science Foundation of China
文摘Microstructures of creep-aged 2524 （A1-4.3Cu-1.5Mg） aged at 170 ℃ with various stresses （0, 173 and 250 MPa） were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy （TEM）. The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S（Al2CuMg） phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.
基金grants from the Key National Basic Research Program of China，Nature Science Foundation of China (81270941) to Ye P,and the Nature Science Foundation of China，the Beijing Nova Program (Z121107002513124) to Bai Y
文摘Background Arterial stiffness and homocysteine are both powerful predictors of cardiovascular disease, especially in older popula tions. Previous studies have investigated the association of homocysteine with arterial stiffness in human subjects, while the relationship between homocysteine and arterial stiffness in the elderly is still indefinite. The current study examined the association of homocysteine with arterial stiffness in Chinese community-based elderly persons. Methods We related serum levels of homocysteine to two measures of arte- rial stiffness （carotid-femoral pulse wave velocity （PWV） and carotid-radial PWV） in 780 participants （46.3% men, mean age 71.9 years （ranging 65-96 years old）） from two communities of Beijing, China. Arterial stiffness were measured within two days of the time of bio- marker measurement. Results In multiple-adjusted models, homocysteine levels was strongly associated with the carotid-femoral PWV （standardized 13 = 0.13, P 〈 0.001）, even after adjustment for classical risk factors of cardiovascular disease. The association is also stronger when the carotid-femoral PWV is elevated above normal, whereas no significant association with homocysteine was observed for ca-rotid-radial PWV. Conclusions In Chinese elderly persons, serum homocysteine levels are associated with alterations of aortic stiffness.
