Ammonia production via electrochemical nitrate reduction is essential for environmental protection and the emerging hydrogen economy. Complex nitrate wastewater with a wide pH range calls for flexible catalysts with h...Ammonia production via electrochemical nitrate reduction is essential for environmental protection and the emerging hydrogen economy. Complex nitrate wastewater with a wide pH range calls for flexible catalysts with high selectivity. A high Faradaic efficiency(FE) of NH3 cannot be obtained under strong acid or alkaline conditions due to the uncontrollable adsorption energy and coverage of hydrogen species(H*) on active sites. This article describes the design and fabrication of a copper-palladium(Cu-Pd) alloy nanocrystal catalyst that inhibits H2 and nitrite generation in electrolytes with different nitrate concentrations and varied pH. The interfacial sites of Cu-Pd alloys could enhance the adsorption energy and coverage of H* while increasing the reaction rate constant of NO_(2)*-to-NO*, which achieves a rapid conversion of NO_(2)* along with a decreased FE of NO_(2)-. Under ambient conditions, optimal FE(NH3) is close to 100% at a wide pH range, with the solar-to-chemical conversion efficiency approaching 4.29%. The combination of thermodynamics and kinetics investigations would offer new insights into the reduction mechanism of NO_(2)* for further development of nitrate reduction.展开更多
Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a ...Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i–t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0–122μmol/L, with a linear correlation coefficient (R^2) of 0.9983 and limit of detection (LOD) of 0.28μmol/L. Sensitivity of this sensor was evaluated as 2550μA L mmol^-1 cm^-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.展开更多
Epstein-Barr virus （EBV） is prevalent throughout the world and is associated with several malignant diseases in humans. Latent membrane protein 2 （LMP2） of EBV plays a crucial role in the pathogenesis of EBV-assoc...Epstein-Barr virus （EBV） is prevalent throughout the world and is associated with several malignant diseases in humans. Latent membrane protein 2 （LMP2） of EBV plays a crucial role in the pathogenesis of EBV-associated tumors; therefore, LMP2 has been considered to be a potential immunodiagnostic and immunotherapeutic target. A multi-epitope-based antigen is a promising option for therapeutic vaccines and diagnoses of such malignancies. In this study, we systematically screened cytotoxic T lymphocyte （CTL）, helper T cell （Th） and B-cell epitopes within EBV-LMP2 using bioinformatics. Based on the screen, two peptides rich in overlapping epitopes of both T cells and B cells were selected to construct a plasmid containing the sequence for a chimeric multi-epitope protein referred to as EBV-LMP2m, which is composed of LMP2aa195-232 and LMP2aa419-436. The EBV-LMP2m protein was expressed in E. coil BL21 （DE3） after prokaryotic codon optimization. Inoculation of the purified chimeric antigen in BALB/c mice induced not only high levels of specific IgG in the serum and secretory IgA in the vaginal mucus but also a specific CTL response. By using purified EBV-LMP2m as an antigen, the presence of specific IgG in the serum specimens of 202 nasopharyngeal carcinoma （NPC） patients was effectively detected with 52.84% sensitivity and 95.40% specificity, which represents an improvement over the traditional detection method based on VCA-IgA （60.53% sensitivity and 76.86% specificity）. The above results indicate that EBV-LMP2m may be used not only as a potential target antigen for EBV-associated tumors but also a diagnostic agent for NPC patients.展开更多
基金supported by the National Key R&D Program of China(2021YFA1500804)the National Natural Science Foundation of China(22121004,51861125104)+1 种基金the Natural Science Foundation of Tianjin City(18JCJQJC47500)Haihe Laboratory of Sustainable Chemical Transformations,the Program of Introducing Talents of Discipline to Universities(BP0618007)and the Xplorer Prize.
文摘Ammonia production via electrochemical nitrate reduction is essential for environmental protection and the emerging hydrogen economy. Complex nitrate wastewater with a wide pH range calls for flexible catalysts with high selectivity. A high Faradaic efficiency(FE) of NH3 cannot be obtained under strong acid or alkaline conditions due to the uncontrollable adsorption energy and coverage of hydrogen species(H*) on active sites. This article describes the design and fabrication of a copper-palladium(Cu-Pd) alloy nanocrystal catalyst that inhibits H2 and nitrite generation in electrolytes with different nitrate concentrations and varied pH. The interfacial sites of Cu-Pd alloys could enhance the adsorption energy and coverage of H* while increasing the reaction rate constant of NO_(2)*-to-NO*, which achieves a rapid conversion of NO_(2)* along with a decreased FE of NO_(2)-. Under ambient conditions, optimal FE(NH3) is close to 100% at a wide pH range, with the solar-to-chemical conversion efficiency approaching 4.29%. The combination of thermodynamics and kinetics investigations would offer new insights into the reduction mechanism of NO_(2)* for further development of nitrate reduction.
基金the financial support of this study by the National Natural Science Foundation of China(NSFC, No. 31860468)
文摘Nanocomposite of Co3O4 and multiwalled carbon nanotube (MCNT) was synthesised using one step solvothermal method, and an electrochemical non-enzymatic glucose sensor (Co3O4-MCNT/GCE) was successfully constructed by a dropping method. The obtained Co3O4 and Co3O4- MCNT were characterized and investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Quantitative analysis of glucose was performed using the amperometric (i–t) method, and plot of current difference versus concentration of glucose was linear in the range of 1.0–122μmol/L, with a linear correlation coefficient (R^2) of 0.9983 and limit of detection (LOD) of 0.28μmol/L. Sensitivity of this sensor was evaluated as 2550μA L mmol^-1 cm^-2. This new sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.
基金This work was supported by a grant from the National Natural Science Foundation of China （No： 81372447）.
文摘Epstein-Barr virus （EBV） is prevalent throughout the world and is associated with several malignant diseases in humans. Latent membrane protein 2 （LMP2） of EBV plays a crucial role in the pathogenesis of EBV-associated tumors; therefore, LMP2 has been considered to be a potential immunodiagnostic and immunotherapeutic target. A multi-epitope-based antigen is a promising option for therapeutic vaccines and diagnoses of such malignancies. In this study, we systematically screened cytotoxic T lymphocyte （CTL）, helper T cell （Th） and B-cell epitopes within EBV-LMP2 using bioinformatics. Based on the screen, two peptides rich in overlapping epitopes of both T cells and B cells were selected to construct a plasmid containing the sequence for a chimeric multi-epitope protein referred to as EBV-LMP2m, which is composed of LMP2aa195-232 and LMP2aa419-436. The EBV-LMP2m protein was expressed in E. coil BL21 （DE3） after prokaryotic codon optimization. Inoculation of the purified chimeric antigen in BALB/c mice induced not only high levels of specific IgG in the serum and secretory IgA in the vaginal mucus but also a specific CTL response. By using purified EBV-LMP2m as an antigen, the presence of specific IgG in the serum specimens of 202 nasopharyngeal carcinoma （NPC） patients was effectively detected with 52.84% sensitivity and 95.40% specificity, which represents an improvement over the traditional detection method based on VCA-IgA （60.53% sensitivity and 76.86% specificity）. The above results indicate that EBV-LMP2m may be used not only as a potential target antigen for EBV-associated tumors but also a diagnostic agent for NPC patients.
基金supported by the National Natural Science Foundation of China (21525626 and 21761132023)the Program of Introducing Talents of Discipline to Universities (BP0618007)。
