In 2001,Tang's team discovered a unique type of luminogens with substantial enhanced fluorescence upon aggregation and introduced the concept of"aggregation-induced emission(AlE)".Unlike conventional flu...In 2001,Tang's team discovered a unique type of luminogens with substantial enhanced fluorescence upon aggregation and introduced the concept of"aggregation-induced emission(AlE)".Unlike conventional fluorescent materials,AlE luminogens(AlEgens)emit weak or no fluorescence in solution but become highly fluorescent in aggregated or solid states,due to a mechanism known as restriction of intramolecular motions(RIM).Initially considered a purely inorganic chemical phenomenon,AIE was later applied in biomedicine to improve the sensitivity of immunoassays.Subsequently,AlE has been extensively explored in various biomedical applications,especially in cell imaging.Early studies achieved nonspecific cell imaging using nontargeted AlEgens,and later,specific cellular imaging was realized through the design of targeted AlEgens.These advancements have enabled the visualization of various biomacromolecules and intracellular organelles,providing valuable insights into cellular microenvironments and statuses.Neurological disorders affect over 3 billion people worldwide,highlighting the urgent need for advanced diagnostic and therapeutic tools.AlEgens offer promising opportunities for imaging the central nervous system(CNS),including nerve cells,neural tissues,and blood vessels.This review focuses on the application of AlEgens in CNS imaging,exploring their roles in the diagnosis of various neurological diseases.We will discuss the evolution and conclude with an outlook on the future challenges and opportunities for AlEgens in clinical diagnostics and therapeutics of CNS disorders.展开更多
The effect of initial fabric anisotropy produced by sample preparation on the shear behavior of granular soil is investigated by performing discrete element method （DEM） simulations of fourteen biaxial tests in drai...The effect of initial fabric anisotropy produced by sample preparation on the shear behavior of granular soil is investigated by performing discrete element method （DEM） simulations of fourteen biaxial tests in drained conditions. Numerical test specimens are prepared by three means： gravitational deposition, multi-layer compression, and isotropic compression, such that different initial inherent soil fabrics are created. The DEM simulation results show that initial fabric anisotropy exerts a considerable effect on the shear behavior of granular soil, and that the peak stress ratio and peak dilatancy increase with an increase in the fabric index an that is estimated from the contact orientations. The stress-dilatancy relationship is found to be independent of the initial fabric anisotropy. The anisotropy related to the contact orientation and contact normal force accounts for the main contribution to the mobilized friction angle. Also, the occurrence of contractive shear response in an initial shearing stage is accompanied by the most intense particle rearrangement and microstructural reorganization, regardless of the sample preparation method. Furthermore, the uniqueness of the critical state line in e-logp＇ and q-p＇ plots is observed, suggesting that the influence of initial fabric anisotropy is erased at large shear strains.展开更多
基金supported by the Natural Science Foundation of the Sichuan Provincial Department of Science and Technology(no.2025ZNSFSC0738)Department of Chengdu Science and Technology(no.2024-YF05-01250-SN)+2 种基金Popularized Application Project of Sichuan Provincial Health Commission(no.chuan-gan-yan2023-214)National Natural Science Foundation of China(no.81603018)Tianfu Jincheng Laboratory,City of Future Medicine(no.TFJC-2024-JB003).
文摘In 2001,Tang's team discovered a unique type of luminogens with substantial enhanced fluorescence upon aggregation and introduced the concept of"aggregation-induced emission(AlE)".Unlike conventional fluorescent materials,AlE luminogens(AlEgens)emit weak or no fluorescence in solution but become highly fluorescent in aggregated or solid states,due to a mechanism known as restriction of intramolecular motions(RIM).Initially considered a purely inorganic chemical phenomenon,AIE was later applied in biomedicine to improve the sensitivity of immunoassays.Subsequently,AlE has been extensively explored in various biomedical applications,especially in cell imaging.Early studies achieved nonspecific cell imaging using nontargeted AlEgens,and later,specific cellular imaging was realized through the design of targeted AlEgens.These advancements have enabled the visualization of various biomacromolecules and intracellular organelles,providing valuable insights into cellular microenvironments and statuses.Neurological disorders affect over 3 billion people worldwide,highlighting the urgent need for advanced diagnostic and therapeutic tools.AlEgens offer promising opportunities for imaging the central nervous system(CNS),including nerve cells,neural tissues,and blood vessels.This review focuses on the application of AlEgens in CNS imaging,exploring their roles in the diagnosis of various neurological diseases.We will discuss the evolution and conclude with an outlook on the future challenges and opportunities for AlEgens in clinical diagnostics and therapeutics of CNS disorders.
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China （Nos. 51209237, 51428901,41030747） and the Fundamental Research Funds for the Central Universities （No. 131gpy05）.
文摘The effect of initial fabric anisotropy produced by sample preparation on the shear behavior of granular soil is investigated by performing discrete element method （DEM） simulations of fourteen biaxial tests in drained conditions. Numerical test specimens are prepared by three means： gravitational deposition, multi-layer compression, and isotropic compression, such that different initial inherent soil fabrics are created. The DEM simulation results show that initial fabric anisotropy exerts a considerable effect on the shear behavior of granular soil, and that the peak stress ratio and peak dilatancy increase with an increase in the fabric index an that is estimated from the contact orientations. The stress-dilatancy relationship is found to be independent of the initial fabric anisotropy. The anisotropy related to the contact orientation and contact normal force accounts for the main contribution to the mobilized friction angle. Also, the occurrence of contractive shear response in an initial shearing stage is accompanied by the most intense particle rearrangement and microstructural reorganization, regardless of the sample preparation method. Furthermore, the uniqueness of the critical state line in e-logp＇ and q-p＇ plots is observed, suggesting that the influence of initial fabric anisotropy is erased at large shear strains.
