High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical respons...High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical responses,namely Cs_(3)C_(6)N_(9)•H_(2)O(I),from its analogue Na_(3)C_(6)N_(9)•3H_(2)O by a facile ion exchange method.In contrast to Na_(3)C_(6)N_(9)•3H_(2)O,I realizes an optimal arrangement of𝜋π-conjugated(C_(6)N_(9))3−anion groups in its crystal structure.As a result,the second-order nonlinear optical(NLO)response is greatly enhanced from nearly zero of Na_(3)C_(6)N_(9)•3H_(2)O to∼9.8×KH_(2)PO_(4)of I.Furthermore,I exhibits a giant linear optical anisotropic response(i.e.birefringence)of 0.52 at the wavelength of 550 nm.Both responses are almost the largest among the inorganic compounds ofπ-conjugated rings,which indicates that I has great potential as a bi-functional optical crystal.Structural and theoretical analyses reveal the microscopic origin of excellent optical properties.This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals.展开更多
Interlayer sliding modulation in van der Waals(vdW)layered materials opens opportunities to seek tunable applications for photonics and optoelectronics at the nanoscale.In this work,focusing on ternary chalcogenides,d...Interlayer sliding modulation in van der Waals(vdW)layered materials opens opportunities to seek tunable applications for photonics and optoelectronics at the nanoscale.In this work,focusing on ternary chalcogenides,dozens of typical vdW layered materials with the formula of A_(2)MZ_(4)(A,M=metal cation;Z=S/Se)were systematically classified and studied to illustrate the interlayer sliding modulation performance on nonlinear optical(NLO)effect and underlying mechanism.Based on first-principles analysis,the screened Cd_(2)GeSe_(4) exhibits large second harmonic generation(SHG)deviation(>36 times between high-and low-SHG states)under sliding among all studied materials.This phenomenon arises from the polarization modulation induced by the vdW interlayer charge redistribution of two tetrahedral primitives in the ternary edge-sharing tetrahedral structures.Our findings present a strategy to substantially modulate NLO properties by altering the interlayer charge coupling which is commonly thought to be very weak in vdW layered materials.展开更多
Despite the growing knowledge of T cell responses in COVID-19 patients,there is a lack of detailed characterizations for T cell-antigen interactions and T cell functions.Here,with a predicted peptide library from SARS...Despite the growing knowledge of T cell responses in COVID-19 patients,there is a lack of detailed characterizations for T cell-antigen interactions and T cell functions.Here,with a predicted peptide library from SARS-CoV-2 S and N proteins,we found that specific CD8+T cell responses were identified in over 75%of COVID-19 convalescent patients(15/20)and an epitope from the N protein,N361-369(KTFPPTEPK),was the most dominant epitope from our selected peptide library.Importantly,we discovered 2 N361-369-specific T cell receptors(TCRs)with high functional avidity that were independent of the CD8 co-receptor.These TCRs exhibited complementary cross-reactivity to several presently reported N361-369 mutant variants,as to the wild-type epitope.Further,the natural functions of these TCRs in the cytotoxic immunity against SARS-CoV-2 were determined with dendritic cells(DCs)and the lung organoid model.We found that the N361-369 epitope could be normally processed and endogenously presented by these different types of antigen presenting cells,to elicit successful activation and effective cytotoxicity of CD8+T cells ex vivo.Our study evidenced potential mechanisms of cellular immunity to SARS-CoV-2,and illuminated potential ways of viral clearance in COVID-19 patients.These results indicate that utilizing CD8-independent TCRs against SARS-CoV-2-associated antigens may provide functional superiority that is beneficial for the adoptive cell immunotherapies based on natural or genetically engineered T cells.Additionally,this information is highly relevant for the development of the next-generation vaccines with protections against continuously emerged SARS-CoV-2 mutant strains.展开更多
基金supported by grant from the scientif ic fund of the Ministry of Personnel for returned overseas expert (2006)Natural Science Foundation Project of CQ CSTC (to Mingjian GE)(CSTC, No.2008BB5210)
基金This work was financially supported by the National Natural Science Foundation of China(22122507,21833010,61975207,22193042,and 21921001)the Natural Science Foundation of Fujian Province(2022J02012)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y202069)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)as well as Fujian Institute of Innovation(FJCXY18010201)in the Chinese Academy of Sciences.
基金the National Natural Science Foundation of China(22122507,21833010,61975207 and 21921001)the Youth Innovation Promotion of Chinese Academy of Sciences(Y202069)+1 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)Fujian Institute of Innovation(FJCXY18010201)in Chinese Academy of Sciences。
文摘High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical responses,namely Cs_(3)C_(6)N_(9)•H_(2)O(I),from its analogue Na_(3)C_(6)N_(9)•3H_(2)O by a facile ion exchange method.In contrast to Na_(3)C_(6)N_(9)•3H_(2)O,I realizes an optimal arrangement of𝜋π-conjugated(C_(6)N_(9))3−anion groups in its crystal structure.As a result,the second-order nonlinear optical(NLO)response is greatly enhanced from nearly zero of Na_(3)C_(6)N_(9)•3H_(2)O to∼9.8×KH_(2)PO_(4)of I.Furthermore,I exhibits a giant linear optical anisotropic response(i.e.birefringence)of 0.52 at the wavelength of 550 nm.Both responses are almost the largest among the inorganic compounds ofπ-conjugated rings,which indicates that I has great potential as a bi-functional optical crystal.Structural and theoretical analyses reveal the microscopic origin of excellent optical properties.This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals.
基金This work is supported by the National Natural Science Foundation of China(Grant No.12174404 and 22133004)the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics.The authors thank Dr.Bonan Zhu and Xuanlin Pan for helpful discussion.
文摘Interlayer sliding modulation in van der Waals(vdW)layered materials opens opportunities to seek tunable applications for photonics and optoelectronics at the nanoscale.In this work,focusing on ternary chalcogenides,dozens of typical vdW layered materials with the formula of A_(2)MZ_(4)(A,M=metal cation;Z=S/Se)were systematically classified and studied to illustrate the interlayer sliding modulation performance on nonlinear optical(NLO)effect and underlying mechanism.Based on first-principles analysis,the screened Cd_(2)GeSe_(4) exhibits large second harmonic generation(SHG)deviation(>36 times between high-and low-SHG states)under sliding among all studied materials.This phenomenon arises from the polarization modulation induced by the vdW interlayer charge redistribution of two tetrahedral primitives in the ternary edge-sharing tetrahedral structures.Our findings present a strategy to substantially modulate NLO properties by altering the interlayer charge coupling which is commonly thought to be very weak in vdW layered materials.
基金This study was supported by the Emergency Project from Chongqing Medical University and Chongqing Medical University fund,China(No.X4457)with the donation from Mr Yuling Feng.
文摘Despite the growing knowledge of T cell responses in COVID-19 patients,there is a lack of detailed characterizations for T cell-antigen interactions and T cell functions.Here,with a predicted peptide library from SARS-CoV-2 S and N proteins,we found that specific CD8+T cell responses were identified in over 75%of COVID-19 convalescent patients(15/20)and an epitope from the N protein,N361-369(KTFPPTEPK),was the most dominant epitope from our selected peptide library.Importantly,we discovered 2 N361-369-specific T cell receptors(TCRs)with high functional avidity that were independent of the CD8 co-receptor.These TCRs exhibited complementary cross-reactivity to several presently reported N361-369 mutant variants,as to the wild-type epitope.Further,the natural functions of these TCRs in the cytotoxic immunity against SARS-CoV-2 were determined with dendritic cells(DCs)and the lung organoid model.We found that the N361-369 epitope could be normally processed and endogenously presented by these different types of antigen presenting cells,to elicit successful activation and effective cytotoxicity of CD8+T cells ex vivo.Our study evidenced potential mechanisms of cellular immunity to SARS-CoV-2,and illuminated potential ways of viral clearance in COVID-19 patients.These results indicate that utilizing CD8-independent TCRs against SARS-CoV-2-associated antigens may provide functional superiority that is beneficial for the adoptive cell immunotherapies based on natural or genetically engineered T cells.Additionally,this information is highly relevant for the development of the next-generation vaccines with protections against continuously emerged SARS-CoV-2 mutant strains.
