This work presents an analysis of the influence of stress anisotropy on cylindrical cavity expansions in an undrained elastic-perfectly plastic soil. This problem was formulated by assuming a large strain in both the ...This work presents an analysis of the influence of stress anisotropy on cylindrical cavity expansions in an undrained elastic-perfectly plastic soil. This problem was formulated by assuming a large strain in both the elastic and plastic zones around the cavity and a plain strain condition during the cavity expansion process. The solutions for the limit pressure, stress, and excess pore pressure were obtained by introducing the anisotropic initial stress coefficient K_0 into the conventional cylindrical cavity expansion method.The proposed solutions were then used to interpret the piezocone penetration test, and the suitability of the solutions was verified by comparing the prediction with the piezocone penetration test data. Subsequently, parametric studies were carried out to investigate the influence of stress anisotropy on the stress, excess pores pressure distributions around an expanding cylindrical cavity, and limit pressure. The results show that the proposed cylindrical cavity expansion method under stress anisotropy is suitable and can be used to investigate the piezocone cone test. The present work improves upon the conventional theoretical framework of cavity expansion and can be applied to the determination of the stresses around axially loaded piles and around in-situ testing devices such as penetrometers.展开更多
Vascular remodeling is a pathological condition with structural changes of blood vessels.Both inside-out and outside-in hypothesis have been put forward to describe mechanisms of vascular remodeling.An integrated mode...Vascular remodeling is a pathological condition with structural changes of blood vessels.Both inside-out and outside-in hypothesis have been put forward to describe mechanisms of vascular remodeling.An integrated model of these two hypotheses emphasizes the importance of immune cells such as monocytes/macrophages,T cells,and dendritic cells.These immune cells are at the center stage to orchestrate cellular proliferation,migration,and interactions of themselves and other vascular cells including endothelial cells(ECs),vascular smooth muscle cells(VSMCs),and fibroblasts.These changes on vascular wall lead to inflammation and oxidative stress that are largely responsible for vascular remodeling.Mineralocorticoid receptor(MR)is a classic nuclear receptor.MR agonist promotes inflammation and oxidative stress and therefore exacerbates vascular remodeling.Conversely,MR antagonists have the opposite effects.MR has direct roles on vascular cells through non-genomic or genomic actions to modulate inflammation and oxidative stress.Recent studies using genetic mouse models have revealed that MR in myeloid cells,VSMCs and ECs all contribute to vascular remodeling.In conclusion,data in the past years have demonstrated that MR is a critical control point in modulating vascular remodeling.Studies will continue to provide evidence with more detailed mechanisms to support this notion.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51420105013&51708063)the State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Grant No.SKLGDUEK1713)Chongqing Research Program of Basic Research and Frontier Technology(Grant No.cstc2017jcyjAX0261)
文摘This work presents an analysis of the influence of stress anisotropy on cylindrical cavity expansions in an undrained elastic-perfectly plastic soil. This problem was formulated by assuming a large strain in both the elastic and plastic zones around the cavity and a plain strain condition during the cavity expansion process. The solutions for the limit pressure, stress, and excess pore pressure were obtained by introducing the anisotropic initial stress coefficient K_0 into the conventional cylindrical cavity expansion method.The proposed solutions were then used to interpret the piezocone penetration test, and the suitability of the solutions was verified by comparing the prediction with the piezocone penetration test data. Subsequently, parametric studies were carried out to investigate the influence of stress anisotropy on the stress, excess pores pressure distributions around an expanding cylindrical cavity, and limit pressure. The results show that the proposed cylindrical cavity expansion method under stress anisotropy is suitable and can be used to investigate the piezocone cone test. The present work improves upon the conventional theoretical framework of cavity expansion and can be applied to the determination of the stresses around axially loaded piles and around in-situ testing devices such as penetrometers.
基金supported by grants from the One Hundred Talents Program of the Chinese Academy of Sciences(2012OHTP06)the National Basic Research Program of China(2012CB524900)the National Natural Science Foundation of China(91339110,31371153,31171133)
文摘Vascular remodeling is a pathological condition with structural changes of blood vessels.Both inside-out and outside-in hypothesis have been put forward to describe mechanisms of vascular remodeling.An integrated model of these two hypotheses emphasizes the importance of immune cells such as monocytes/macrophages,T cells,and dendritic cells.These immune cells are at the center stage to orchestrate cellular proliferation,migration,and interactions of themselves and other vascular cells including endothelial cells(ECs),vascular smooth muscle cells(VSMCs),and fibroblasts.These changes on vascular wall lead to inflammation and oxidative stress that are largely responsible for vascular remodeling.Mineralocorticoid receptor(MR)is a classic nuclear receptor.MR agonist promotes inflammation and oxidative stress and therefore exacerbates vascular remodeling.Conversely,MR antagonists have the opposite effects.MR has direct roles on vascular cells through non-genomic or genomic actions to modulate inflammation and oxidative stress.Recent studies using genetic mouse models have revealed that MR in myeloid cells,VSMCs and ECs all contribute to vascular remodeling.In conclusion,data in the past years have demonstrated that MR is a critical control point in modulating vascular remodeling.Studies will continue to provide evidence with more detailed mechanisms to support this notion.
