Alzheimer’s disease is a common progressive neurodegenerative disorder, pathologically characterized by the presence of β-amyloid plaques and neurofibrillary tangles. Current treatment approaches using drugs only al...Alzheimer’s disease is a common progressive neurodegenerative disorder, pathologically characterized by the presence of β-amyloid plaques and neurofibrillary tangles. Current treatment approaches using drugs only alleviate the symptoms without curing the disease, which is a serious issue and influences the quality of life of the patients and their caregivers. In recent years, stem cell technology has provided new insights into the treatment of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Currently, the main sources of stem cells include neural stem cells, embryonic stem cells, mesenchymal stem cells, and induced pluripotent stem cells. In this review, we discuss the pathophysiology and general treatment of Alzheimer’s disease, and the current state of stem cell transplantation in the treatment of Alzheimer’s disease. We also assess future challenges in the clinical application and drug development of stem cell transplantation as a treatment for Alzheimer’s disease.展开更多
Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,r...Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.展开更多
Intermetallic Ti-45Al-8Nb-(W,B,Y)(at.%)and Ti-46Al-5Nb alloys are directionally solidified at a constant growth rate of 30μm·s-1 using a Bridgman type apparatus.The quenched microstructures and lengths of differ...Intermetallic Ti-45Al-8Nb-(W,B,Y)(at.%)and Ti-46Al-5Nb alloys are directionally solidified at a constant growth rate of 30μm·s-1 using a Bridgman type apparatus.The quenched microstructures and lengths of different phase regions were observed and measured after various growing times of 0-30 min.Results show that the phase transformations in different phase regions are mainly depending on the high temperature microstructure and the supercooling degree during quenching process.After isothermal holding,the primary phase grows into the liquid phase,the dendrites change from equiaxed to columnar grains,and the length of the L+βphase region,L+β+αphase region and mushy zone varies,indicating that the entire directional solidification process can be described by a static equilibrium-nonequilibrium-dynamic equilibrium evolution process.In addition,the gap between the original growth interface and front interface shows that the actual crystal growth rate is not equal to the drawing velocity during directional solidification.展开更多
As a model molecule of actinide chemistry,UO molecule plays an important role in understanding the electronic structure and chemical bonding of actinide-containing species.We report a study of the laser-induced fluore...As a model molecule of actinide chemistry,UO molecule plays an important role in understanding the electronic structure and chemical bonding of actinide-containing species.We report a study of the laser-induced fluorescence spectra of the U^(16)O and U^(18)O using two-dimensional spectroscopy.Several rotationally resolved excitation spectra were investigated.Accurate molecular rotational constants and equilibrium internuclear distances were reported.Low-lying electronic states information was extracted from high resolution dispersed fluorescence spectra and analyzed by the ligand field theory model.The configuration of the ground state was determined as U^(2+)(5 f^(3)7 s)O^(2-).The branching ratios,and the vibrational harmonic and anharmonic parameters were also obtained.Radiative lifetimes were determined by recording the timeresolved fluorescence spectroscopy.Transition dipole moments were calculated using the branching ratios and the radiative lifetimes.These findings were elucidated by using quantum-chemical calculations,and the chemical bonding was also analyzed.The findings presented in this work will enrich our understanding of actinide-containing molecules.展开更多
Metal halide perovskites based on MX6(M is metal and X is halogen)octahedra have developed into significant materials,extensively used in many fields,such as solid-state lighting,semiconductor,and nonlinear optics.How...Metal halide perovskites based on MX6(M is metal and X is halogen)octahedra have developed into significant materials,extensively used in many fields,such as solid-state lighting,semiconductor,and nonlinear optics.However,the MX_(5)square pyramid-based hybrid metal halides beyond zero-dimensional(0D)polyhedrons and clusters are rarely reported.Herein,we reported two new isostructural hybrid antimony halides,namely(2cepyH)SbCl4(1-Cl)and(2cepyH)SbBr4(2-Br)(2cepy=1-(2-chloroethyl)pyrrolidine),characterized by 1D polar polyanionic chains formed by corner-sharing SbX_(5)tetragonal pyramid units.Upon photoexcitation at 340 nm,1-Cl shows broad,yellow phosphorescence emissions stemming from triplet self-trapped excitons,as proved by its long lifetime(6.85μs)and the temperature dependences of broadband emission.To our knowledge,this should be the first observation on the broadband emissive properties in the 1D hybrid metal halide constructed by MX_(5)tetragonal pyramid units.Moreover,second harmonic generation measurements show that the nonlinear optical properties of 2-Br(∼3.2×KDP)are superior to that of 1-Cl(∼1.8×KDP).Experimental and calculated data indicate that the bandgap of 1-Cl is larger than that of 2-Br and that the polar inorganic moieties determine their band structures.Our work opens up a new way for constructing broadband emission materials with novel polar frameworks.展开更多
基金supported by the National Natural Science Foundation of China(No.21571119 and No.21603130)the Shanxi Province Science Foundation for Youths(No.201901D211395)+1 种基金the 1331 Engineering of Shanxi Provincethe Start-up fund from Shanxi Normal University。
基金supported by the National Natural Science Foundation of China,No.81701076(to LLZ)and No.31670795(to XQF)2017 Changbai Mountain Research Support Foundation,No.440050117010(to XQF)+1 种基金Opening Project of Zhejiang Provincial Top Key Discipline of Pharmaceutical Sciences,No.YKFJ2-007(to LLZ)grants from the Science and Technology Department of Jilin Province,China,No.20190701037GH(to FQZ),20180520138JH(to FQZ),20190701036GH(to LLZ)
文摘Alzheimer’s disease is a common progressive neurodegenerative disorder, pathologically characterized by the presence of β-amyloid plaques and neurofibrillary tangles. Current treatment approaches using drugs only alleviate the symptoms without curing the disease, which is a serious issue and influences the quality of life of the patients and their caregivers. In recent years, stem cell technology has provided new insights into the treatment of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Currently, the main sources of stem cells include neural stem cells, embryonic stem cells, mesenchymal stem cells, and induced pluripotent stem cells. In this review, we discuss the pathophysiology and general treatment of Alzheimer’s disease, and the current state of stem cell transplantation in the treatment of Alzheimer’s disease. We also assess future challenges in the clinical application and drug development of stem cell transplantation as a treatment for Alzheimer’s disease.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575138,11835006,11690040,and 11690043)
文摘Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.
基金the National Natural Science Foundation of China(Nos.:51671026,51831001,and 51921001)the Fundamental Research Funds for the Central Universities(No.FRF-GF-19-024B)。
文摘Intermetallic Ti-45Al-8Nb-(W,B,Y)(at.%)and Ti-46Al-5Nb alloys are directionally solidified at a constant growth rate of 30μm·s-1 using a Bridgman type apparatus.The quenched microstructures and lengths of different phase regions were observed and measured after various growing times of 0-30 min.Results show that the phase transformations in different phase regions are mainly depending on the high temperature microstructure and the supercooling degree during quenching process.After isothermal holding,the primary phase grows into the liquid phase,the dendrites change from equiaxed to columnar grains,and the length of the L+βphase region,L+β+αphase region and mushy zone varies,indicating that the entire directional solidification process can be described by a static equilibrium-nonequilibrium-dynamic equilibrium evolution process.In addition,the gap between the original growth interface and front interface shows that the actual crystal growth rate is not equal to the drawing velocity during directional solidification.
基金Project supported by the National Natural Science Foundation of China(Grant No.21903050)。
文摘As a model molecule of actinide chemistry,UO molecule plays an important role in understanding the electronic structure and chemical bonding of actinide-containing species.We report a study of the laser-induced fluorescence spectra of the U^(16)O and U^(18)O using two-dimensional spectroscopy.Several rotationally resolved excitation spectra were investigated.Accurate molecular rotational constants and equilibrium internuclear distances were reported.Low-lying electronic states information was extracted from high resolution dispersed fluorescence spectra and analyzed by the ligand field theory model.The configuration of the ground state was determined as U^(2+)(5 f^(3)7 s)O^(2-).The branching ratios,and the vibrational harmonic and anharmonic parameters were also obtained.Radiative lifetimes were determined by recording the timeresolved fluorescence spectroscopy.Transition dipole moments were calculated using the branching ratios and the radiative lifetimes.These findings were elucidated by using quantum-chemical calculations,and the chemical bonding was also analyzed.The findings presented in this work will enrich our understanding of actinide-containing molecules.
基金supported by the Natural Science Foundation of China(21871167,22075168)the 1331 Project of Shanxi Province+1 种基金the Science and Technology Innovation Project in Colleges and Universities of Shanxi Province(2019L0451)the Shanxi Normal University Startup。
文摘Metal halide perovskites based on MX6(M is metal and X is halogen)octahedra have developed into significant materials,extensively used in many fields,such as solid-state lighting,semiconductor,and nonlinear optics.However,the MX_(5)square pyramid-based hybrid metal halides beyond zero-dimensional(0D)polyhedrons and clusters are rarely reported.Herein,we reported two new isostructural hybrid antimony halides,namely(2cepyH)SbCl4(1-Cl)and(2cepyH)SbBr4(2-Br)(2cepy=1-(2-chloroethyl)pyrrolidine),characterized by 1D polar polyanionic chains formed by corner-sharing SbX_(5)tetragonal pyramid units.Upon photoexcitation at 340 nm,1-Cl shows broad,yellow phosphorescence emissions stemming from triplet self-trapped excitons,as proved by its long lifetime(6.85μs)and the temperature dependences of broadband emission.To our knowledge,this should be the first observation on the broadband emissive properties in the 1D hybrid metal halide constructed by MX_(5)tetragonal pyramid units.Moreover,second harmonic generation measurements show that the nonlinear optical properties of 2-Br(∼3.2×KDP)are superior to that of 1-Cl(∼1.8×KDP).Experimental and calculated data indicate that the bandgap of 1-Cl is larger than that of 2-Br and that the polar inorganic moieties determine their band structures.Our work opens up a new way for constructing broadband emission materials with novel polar frameworks.
