The effects of applied tensile strain on the coherent α_2→O-phase transformation in Ti-Al-Nb alloys are explored bycomputer simulation using a phase-field method. The focus is on the influence of the applied strain ...The effects of applied tensile strain on the coherent α_2→O-phase transformation in Ti-Al-Nb alloys are explored bycomputer simulation using a phase-field method. The focus is on the influence of the applied strain direction onthe microstructure and volume fraction of the O-phase precipitates. It is found that altering applied strain directioncan modify microstructure of Ti-25Al-10～12Nb (at. pct) alloy during α_2→O-phase transformation effectively andfull laminate microstructure in the Ti-25Al-10Nb (at. pct) alloy can be realized by an applied strain only along thedirection 30°away from the α_2 phase <1010> in magnitude equivalent to the stress-free transformation strain. Thesimulation also shows that not only the magnitude of applied strain but also the applied strain direction influencesthe O-phase volume fraction and the effect of strain direction on the volume fraction is up to 25%.展开更多
Segregation of solutes/impurities in the interfaces plays a decisive role in material performances.However,the segregation of solutes/impurities remains elusive due to the diversity of interfacial structures.Here,in a...Segregation of solutes/impurities in the interfaces plays a decisive role in material performances.However,the segregation of solutes/impurities remains elusive due to the diversity of interfacial structures.Here,in a Mg-Nd-Mn ternary model system,two ordered novel two-dimensional(2D)interfacial superstructures formed by periodic segregation of solute atoms in special symmetric and asymmetric tilt grain boundaries(GBs)have been systematically investigated.Z-Contrast high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)observations provided the atomic-level details on how solute atoms were arranged on these special partially coherent tilt GBs.The strained conditions of each atomic site at the tilt GBs were accurately reproduced by molecular dynamics(MD)simulations plus Voronoi analysis,and the rationality of solute segregation in each atomic-site was evaluated carefully based on the first-principles calculations.These findings expand our knowledge of solute/impurity segregation behaviors in the interfaces,especially the co-segregation behaviors in multi-component materials.展开更多
The microenvironment of distant organs affects the colonization and growth of disseminated tumor cells.It remains unclear how tumor-associated neutrophils are influenced by the microenvironment of distant organs.Here,...The microenvironment of distant organs affects the colonization and growth of disseminated tumor cells.It remains unclear how tumor-associated neutrophils are influenced by the microenvironment of distant organs.Here,we demonstrate that mature low-density neutrophils in colorectal cancer patients abnormally accumulate neutral lipids and induce the reactivation of dormant tumor cells,a process regulated by hepatic stellate cells.Mechanistically,activated hepatic stellate cells increased DGAT1/2-dependent lipid droplet synthesis in low-density neutrophils through the secretion of IL33,thereby maintaining the survival and immunosuppressive function of these neutrophils.The uptake of lipids from lipid-laden low-density neutrophils drives dormant tumor cell reactivation through the potentiation ofβ-oxidation and the stimulation of protumorigenic eicosanoid synthesis.In mouse models,targeting IL33 blocked neutrophil lipid synthesis,decreased the colonization of colorectal cancer cells in the liver,and enhanced the efficacy of immunotherapy.Overall,our study revealed that lipid accumulation in mature low-density neutrophils regulates the growth of dormant tumor cells and antitumor immunity to facilitate colorectal cancer liver metastasis.Targeting IL33 could be a promising therapeutic approach for colorectal cancer liver metastases.展开更多
文摘The effects of applied tensile strain on the coherent α_2→O-phase transformation in Ti-Al-Nb alloys are explored bycomputer simulation using a phase-field method. The focus is on the influence of the applied strain direction onthe microstructure and volume fraction of the O-phase precipitates. It is found that altering applied strain directioncan modify microstructure of Ti-25Al-10～12Nb (at. pct) alloy during α_2→O-phase transformation effectively andfull laminate microstructure in the Ti-25Al-10Nb (at. pct) alloy can be realized by an applied strain only along thedirection 30°away from the α_2 phase <1010> in magnitude equivalent to the stress-free transformation strain. Thesimulation also shows that not only the magnitude of applied strain but also the applied strain direction influencesthe O-phase volume fraction and the effect of strain direction on the volume fraction is up to 25%.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3701002)the National Natural Science Foundation of China(No.52101129)the Fundamental Research Funds for the Central Universities(Nos.N2202013 and N2007011).
文摘Segregation of solutes/impurities in the interfaces plays a decisive role in material performances.However,the segregation of solutes/impurities remains elusive due to the diversity of interfacial structures.Here,in a Mg-Nd-Mn ternary model system,two ordered novel two-dimensional(2D)interfacial superstructures formed by periodic segregation of solute atoms in special symmetric and asymmetric tilt grain boundaries(GBs)have been systematically investigated.Z-Contrast high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)observations provided the atomic-level details on how solute atoms were arranged on these special partially coherent tilt GBs.The strained conditions of each atomic site at the tilt GBs were accurately reproduced by molecular dynamics(MD)simulations plus Voronoi analysis,and the rationality of solute segregation in each atomic-site was evaluated carefully based on the first-principles calculations.These findings expand our knowledge of solute/impurity segregation behaviors in the interfaces,especially the co-segregation behaviors in multi-component materials.
基金supported by the National Natural Science Foundation of China,grants 81802326,82473026 and 81871933。
文摘The microenvironment of distant organs affects the colonization and growth of disseminated tumor cells.It remains unclear how tumor-associated neutrophils are influenced by the microenvironment of distant organs.Here,we demonstrate that mature low-density neutrophils in colorectal cancer patients abnormally accumulate neutral lipids and induce the reactivation of dormant tumor cells,a process regulated by hepatic stellate cells.Mechanistically,activated hepatic stellate cells increased DGAT1/2-dependent lipid droplet synthesis in low-density neutrophils through the secretion of IL33,thereby maintaining the survival and immunosuppressive function of these neutrophils.The uptake of lipids from lipid-laden low-density neutrophils drives dormant tumor cell reactivation through the potentiation ofβ-oxidation and the stimulation of protumorigenic eicosanoid synthesis.In mouse models,targeting IL33 blocked neutrophil lipid synthesis,decreased the colonization of colorectal cancer cells in the liver,and enhanced the efficacy of immunotherapy.Overall,our study revealed that lipid accumulation in mature low-density neutrophils regulates the growth of dormant tumor cells and antitumor immunity to facilitate colorectal cancer liver metastasis.Targeting IL33 could be a promising therapeutic approach for colorectal cancer liver metastases.
