Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topologica...Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topological states within one type of materials is,however,seldom reported.Based on first-principles calculations and tightbinding models,we investigate topological electronic states in a novel family of 2D halogenated tetragonal stanene(T-SnX,X=F,Cl,Br,I).All the four monolayers are found to be unusual topological nodal-line semimetals(NLSs),protected by a glide mirror symmetry.When spin-orbit coupling(SOC)is turned on,T-SnF and TSnCl are still ascertained as topological NLSs due to the remaining band inversion,primarily composed of Sn pxy orbitals,while T-Sn Br and T-SnI become quantum spin Hall insulators.The phase transition is ascribed to moving up in energy of Sn s orbitals and increasing of SOC strengths.The topology origin in the materials is uniformly rationalized through elementary band representations.The robust and diverse topological states found in the 2D T-SnX monolayers position them as an excellent material platform for development of innovative topological electronics.展开更多
This paper proposes a three-dimensional(3 D) controlled quantum teleportation scheme for an unknown single-qutrit state. The scheme is first introduced in an ideal environment, and its detailed implementation is descr...This paper proposes a three-dimensional(3 D) controlled quantum teleportation scheme for an unknown single-qutrit state. The scheme is first introduced in an ideal environment, and its detailed implementation is described via the transformation of the quantum system. Four types of 3 D-Pauli-like noise corresponding to Weyl operators are created by Kraus operators: trit-flip, t-phase-flip, trit-phase-flip, and t-depolarizing. Then, this scheme is analyzed in terms of four types of noisy channel with memory. For each type of noise, the average fidelity is calculated as a function of memory and noise parameters, which is afterwards compared with classical fidelity. The results demonstrate that for trit-flip and t-depolarizing noises, memory will increase the average fidelity regardless of the noise parameter. However, for t-phase-flip and trit-phaseflip noises, memory may become ineffective in increasing the average fidelity above a certain noise threshold.展开更多
Cytotoxic T cells （CTLs） play a key role in the control of Hepatitis B virus （HBV） infection and viral clearance. However, most of identified CTL epitopes are derived from HBV of genotypes A and D, and few have be...Cytotoxic T cells （CTLs） play a key role in the control of Hepatitis B virus （HBV） infection and viral clearance. However, most of identified CTL epitopes are derived from HBV of genotypes A and D, and few have been defined in virus of genotypes B and C which are more prevalent in Asia. As HBV core protein （HBc） is the most conservative and immunogenic component, in this study we used an overlapping 9-mer peptide pool cov- ering HBc to screen and identify specific CTL epitopes. An unconventional HLA-A2-restricted epitope HBc141- 149 was discovered and structurally characterized by crystallization analysis. The immunogenicity and anti- HBV activity were further determined in HBV and HLA- A2 transgenic mice. Finally, we show that mutations in HBc141-149 epitope are associated with viral parame- ters and disease progression in HBV infected patients. Our data therefore provide insights into the structure characteristics of this unconventional epitope binding to MHC-I molecules, as well as epitope specific CTL activity that orchestrate T cell response and immune evasion in HBV infected patients.展开更多
The demonstration that for infectious diseases vaccine-induced immunity is in principle only effective before rather than after infection occurs,provides valuable insights in understanding the nature of immune system ...The demonstration that for infectious diseases vaccine-induced immunity is in principle only effective before rather than after infection occurs,provides valuable insights in understanding the nature of immune system and the challenges in cancer treatment.Besides the already known underlying counter-back mechanisms,the astronomical numbers of tumor cells in established tumors could overwhelm the limited amount of specific T cells induced by vaccination,which may account for the modest efficiency of immunotherapy against cancer.We speculate that the long window period for cancer development will allow immune-intervening strategies(e.g.,the proper prophylactic vaccination)to promote adaptive mechanisms toward an enhanced immunosurveillance,which could effectively eradicate or at least control the few precancerous cells undergoing neoplastic transformation during early premalignant stages in cancer development,and protect the host from lethal tumor formation.It should be emphasized that the pre-cancer-associated antigens but not the tumorassociated antigens seem to be the suitable antigens for designing prophylactic cancer vaccines.In addition,an ideal prophylactic cancer vaccine may contain multiple pre-cancer-associated antigens,which will provide broad and effective immune protection in a heterogeneous human population.Finally,we demonstrated that placenta-derived gp96,which can be readily obtained in high amount for vaccination,has the ability to initiate antitumor T-cell immunity via association with multiple embryo-cancer antigens.Further understanding placental gp96 associated with carcinoembryonic antigen repertoires that orchestrate immune defense networks against cancer formation will allow to provide an effective prophylactic approach in cancer prevention.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12174059,11874117,11904101,and 11604134)the Natural Science Foundation of Shanghai(Grant No.21ZR140820)。
文摘Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topological states within one type of materials is,however,seldom reported.Based on first-principles calculations and tightbinding models,we investigate topological electronic states in a novel family of 2D halogenated tetragonal stanene(T-SnX,X=F,Cl,Br,I).All the four monolayers are found to be unusual topological nodal-line semimetals(NLSs),protected by a glide mirror symmetry.When spin-orbit coupling(SOC)is turned on,T-SnF and TSnCl are still ascertained as topological NLSs due to the remaining band inversion,primarily composed of Sn pxy orbitals,while T-Sn Br and T-SnI become quantum spin Hall insulators.The phase transition is ascribed to moving up in energy of Sn s orbitals and increasing of SOC strengths.The topology origin in the materials is uniformly rationalized through elementary band representations.The robust and diverse topological states found in the 2D T-SnX monolayers position them as an excellent material platform for development of innovative topological electronics.
基金supported by the Natural Science Research Project of Colleges and Universities in Anhui Province,China (Grant No. KJ2020A0301)the Science and Technology Project of Wuhu City in 2020 (Grant No. 2020yf48)。
文摘This paper proposes a three-dimensional(3 D) controlled quantum teleportation scheme for an unknown single-qutrit state. The scheme is first introduced in an ideal environment, and its detailed implementation is described via the transformation of the quantum system. Four types of 3 D-Pauli-like noise corresponding to Weyl operators are created by Kraus operators: trit-flip, t-phase-flip, trit-phase-flip, and t-depolarizing. Then, this scheme is analyzed in terms of four types of noisy channel with memory. For each type of noise, the average fidelity is calculated as a function of memory and noise parameters, which is afterwards compared with classical fidelity. The results demonstrate that for trit-flip and t-depolarizing noises, memory will increase the average fidelity regardless of the noise parameter. However, for t-phase-flip and trit-phaseflip noises, memory may become ineffective in increasing the average fidelity above a certain noise threshold.
文摘Cytotoxic T cells （CTLs） play a key role in the control of Hepatitis B virus （HBV） infection and viral clearance. However, most of identified CTL epitopes are derived from HBV of genotypes A and D, and few have been defined in virus of genotypes B and C which are more prevalent in Asia. As HBV core protein （HBc） is the most conservative and immunogenic component, in this study we used an overlapping 9-mer peptide pool cov- ering HBc to screen and identify specific CTL epitopes. An unconventional HLA-A2-restricted epitope HBc141- 149 was discovered and structurally characterized by crystallization analysis. The immunogenicity and anti- HBV activity were further determined in HBV and HLA- A2 transgenic mice. Finally, we show that mutations in HBc141-149 epitope are associated with viral parame- ters and disease progression in HBV infected patients. Our data therefore provide insights into the structure characteristics of this unconventional epitope binding to MHC-I molecules, as well as epitope specific CTL activity that orchestrate T cell response and immune evasion in HBV infected patients.
基金supported by the National Natural Science Foundation of China(31230026,91029724,81021003 and 81102018)Beijing Natural Science Foundation(5112021)
文摘The demonstration that for infectious diseases vaccine-induced immunity is in principle only effective before rather than after infection occurs,provides valuable insights in understanding the nature of immune system and the challenges in cancer treatment.Besides the already known underlying counter-back mechanisms,the astronomical numbers of tumor cells in established tumors could overwhelm the limited amount of specific T cells induced by vaccination,which may account for the modest efficiency of immunotherapy against cancer.We speculate that the long window period for cancer development will allow immune-intervening strategies(e.g.,the proper prophylactic vaccination)to promote adaptive mechanisms toward an enhanced immunosurveillance,which could effectively eradicate or at least control the few precancerous cells undergoing neoplastic transformation during early premalignant stages in cancer development,and protect the host from lethal tumor formation.It should be emphasized that the pre-cancer-associated antigens but not the tumorassociated antigens seem to be the suitable antigens for designing prophylactic cancer vaccines.In addition,an ideal prophylactic cancer vaccine may contain multiple pre-cancer-associated antigens,which will provide broad and effective immune protection in a heterogeneous human population.Finally,we demonstrated that placenta-derived gp96,which can be readily obtained in high amount for vaccination,has the ability to initiate antitumor T-cell immunity via association with multiple embryo-cancer antigens.Further understanding placental gp96 associated with carcinoembryonic antigen repertoires that orchestrate immune defense networks against cancer formation will allow to provide an effective prophylactic approach in cancer prevention.
