Adipose-derived stromal cells （ASCs） have gained great attention in regenerative medicine. Progress in our understanding of adult neovascularization further suggests the potential of ASCs in promoting vascular regen...Adipose-derived stromal cells （ASCs） have gained great attention in regenerative medicine. Progress in our understanding of adult neovascularization further suggests the potential of ASCs in promoting vascular regeneration, although the specific cues that stimulate their angiogenic behavior remain controversial In this study, we established a three-dimensional （3D） angiogenesis model by co-culturing ASCs and endothelial cells （ECs） in collagen gel and found that ASC-EC-instructed angiogenesis was regulated by the canonical Wnt pathway. Furthermore, the angiogenesis that occurred in implants collected after injections of our collagen gel- based 3D angiogenesis model into nude mice was confirmed to be functional and also regulated by the canonical Wnt pathway. Wnt regulation of angiogenesis involving changes in vessel length, vessel density, vessel sprout, and connection numbers occurred in our system. Wnt signaling was then shown to regulate ASC- mediated paracrine signaling during angiogenesis through the nuclear translocation of β-catenin after its cytoplasmic accumulation in both ASCs and ECs. This translocation enhanced the expression of nuclear cofactor Lef-1 and cyclin D1 and activated the angiogenic transcription of vascular endothelial growth factor A （VEGFA）, basic fibroblast growth factor （bFGF）, and insulin-like growth factor 1 （IGF-1）. The angiogenesis process in the 3D collagen model appeared to follow canonical Wnt signaling, and this model can help us understand the importance of the canonical Wnt pathway in the use of ASCs in vascular regeneration.展开更多
When a ship sails at high speed,breaking bow waves are formed at the bow,resulting in the component of ship resistance associated with wave-breaking-induced energy dissipation and air entrainment.In this paper,we prop...When a ship sails at high speed,breaking bow waves are formed at the bow,resulting in the component of ship resistance associated with wave-breaking-induced energy dissipation and air entrainment.In this paper,we propose a multi-resolution multi-graphics processing unit two-phase smoothed particle hydrodynamics(SPH)method to simulate the breaking bow waves of a KRISO Container Ship(KCS)model at different Froude numbers.Simulations of five different Froude numbers(Fr=0.377,0.400,0.424,0.450,0.470)are carried out.The total number of particles reaches 1.1×10^(8).The computed wave elevations are compared with the experimental results,which were obtained with the KCS model in a circulating water channel using a binocular stereo reconstruction method.A good agreement is found.The mean wave elevation and its standard deviation,the velocity field,and the vortex structures are analyzed.The results show that increasing the Froude number can lead to more intense fluctuations in wave elevation.The breaking bow waves at the first two Froude numbers are classified as spilling breakers,while those at the last three Froude numbers are plunging breakers.The area of the cavity formed at the impact cross-section increases with the increase of the Froude number.Three main vortex structures are identified for plunging breakers.Vorticity is distributed at the wave crest for spilling breakers,while for plunging breakers,a significant amount of vorticity is found around the cavity.展开更多
基金funded by the National Natural Science Foundation of China(81771125,81471803,81671031)the Sichuan Province Youth Science and Technology Innovation Team(2014TD0001)
文摘Adipose-derived stromal cells （ASCs） have gained great attention in regenerative medicine. Progress in our understanding of adult neovascularization further suggests the potential of ASCs in promoting vascular regeneration, although the specific cues that stimulate their angiogenic behavior remain controversial In this study, we established a three-dimensional （3D） angiogenesis model by co-culturing ASCs and endothelial cells （ECs） in collagen gel and found that ASC-EC-instructed angiogenesis was regulated by the canonical Wnt pathway. Furthermore, the angiogenesis that occurred in implants collected after injections of our collagen gel- based 3D angiogenesis model into nude mice was confirmed to be functional and also regulated by the canonical Wnt pathway. Wnt regulation of angiogenesis involving changes in vessel length, vessel density, vessel sprout, and connection numbers occurred in our system. Wnt signaling was then shown to regulate ASC- mediated paracrine signaling during angiogenesis through the nuclear translocation of β-catenin after its cytoplasmic accumulation in both ASCs and ECs. This translocation enhanced the expression of nuclear cofactor Lef-1 and cyclin D1 and activated the angiogenic transcription of vascular endothelial growth factor A （VEGFA）, basic fibroblast growth factor （bFGF）, and insulin-like growth factor 1 （IGF-1）. The angiogenesis process in the 3D collagen model appeared to follow canonical Wnt signaling, and this model can help us understand the importance of the canonical Wnt pathway in the use of ASCs in vascular regeneration.
基金Project supported by the National Natural Science Foundation of China(Grant No.U22B6010).
文摘When a ship sails at high speed,breaking bow waves are formed at the bow,resulting in the component of ship resistance associated with wave-breaking-induced energy dissipation and air entrainment.In this paper,we propose a multi-resolution multi-graphics processing unit two-phase smoothed particle hydrodynamics(SPH)method to simulate the breaking bow waves of a KRISO Container Ship(KCS)model at different Froude numbers.Simulations of five different Froude numbers(Fr=0.377,0.400,0.424,0.450,0.470)are carried out.The total number of particles reaches 1.1×10^(8).The computed wave elevations are compared with the experimental results,which were obtained with the KCS model in a circulating water channel using a binocular stereo reconstruction method.A good agreement is found.The mean wave elevation and its standard deviation,the velocity field,and the vortex structures are analyzed.The results show that increasing the Froude number can lead to more intense fluctuations in wave elevation.The breaking bow waves at the first two Froude numbers are classified as spilling breakers,while those at the last three Froude numbers are plunging breakers.The area of the cavity formed at the impact cross-section increases with the increase of the Froude number.Three main vortex structures are identified for plunging breakers.Vorticity is distributed at the wave crest for spilling breakers,while for plunging breakers,a significant amount of vorticity is found around the cavity.
