The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to...The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).展开更多
Background:Immunosuppressive medication reduces the immunogenicity of the coronavirus disease 2019(COVID-19)vaccines in patients with rheumatic and musculoskeletal diseases(RMDs).However,the underlying mechanism remai...Background:Immunosuppressive medication reduces the immunogenicity of the coronavirus disease 2019(COVID-19)vaccines in patients with rheumatic and musculoskeletal diseases(RMDs).However,the underlying mechanism remains unclear.The primary aim of our study was to dissect the impact of immunosuppressive medication on cellular and humoral immune responses in RMD patients receiving the inactivated COVID-19 vaccine.Methods:A total of 28 RMD patients and five healthy controls(HCs)receiving two doses of the inactivated COVID-19 vaccine(Sinovac-CoronaVac)were prospectively enrolled.Blood samples were collected before the primary vaccination(Week 0)and one week after the second vaccination(Week 5).Neutralizing antibody(nAb)titers and autoantibody titers were measured by a pseudovirus-based neutralization assay and enzyme-linked immunosorbent assay,respectively.CD4^(+)T-cell and CD19^(+)B-cell subsets and serum cytokines were analyzed by flow cytometry.Results:The inactivated COVID-19 vaccine was immunogenic in RMD patients and HCs after the second vaccination,but the nAb titers were lower in RMD patients than those in HCs.Only patients with systemic lupus erythematosus(SLE)had notably increased nAb titers.Remarkably,IgG^(+)CD27^(+),IgG^(+)IgG1^(+),and IgG^(+)IgG1^(−)B cells were reduced,whereas IgG−IgG1^(+)B cells,and total IgA and IgG titers were markedly increased.However,Tfh cell and Tfr cell subsets and cytokines produced by Tfh cells were not increased.The flare rate was low in RMD patients with comparable autoantibody titers,unchanged CD4^(+)T cell subsets and serum proinflammatory cytokines(interleukin[IL]-6,IL-17,interferon-γ,and tumor necrosis factor-α)after the second vaccination.Conclusions:Immunosuppressive therapy decreased the immunogenicity of the vaccine and maintained a low flare rate by selectively modulating B cell but not CD4^(+)T cell responses in RMD patients receiving the inactivated COVID-19 vaccine.Optimization of the treatment regimen might ensure a durable and robust COVID-19 vaccination response.展开更多
The increasing emission of carbon dioxide （CO2） caused by the unrestrained consumption of fossil fuels in recent hundreds of years, has caused global environmental and social problems. Meanwhile, CO2 is a cheap, abu...The increasing emission of carbon dioxide （CO2） caused by the unrestrained consumption of fossil fuels in recent hundreds of years, has caused global environmental and social problems. Meanwhile, CO2 is a cheap, abundant and renewable Cl-feedstock, which can be converted into alco- hols, ethers, acids and other value-added chemicals. Compared with the thermal reactions, electrochemical reduction of CO2 is more attractive because of its advantages by using the seasonal, geographical and intermittent energy （tide, wind and solar） under mild conditions. In recent years, taking ionic liquids （ILs） as electrolytes in the CO2 electrochemical reduction reaction has been paid much more attention due to the advantages of lowering the overpotential of CO2 electroreduction and improving the Faradaic efficiency. In this paper, we summarized the recent progresses of electrochemical re- duction of CO2 in ILs electrolytes, and analyzed the reaction mechanism of CO2 reaction in the electrode-electrolyte interface region by experimental and simulation methods. Finally, the research which needs to be highlighted in this area was proposed.展开更多
Greenness identification from crop images captured outdoors is the important step for crop growth monitoring.The commonly used methods for greenness identification are based on visible spectral-index,such as the exces...Greenness identification from crop images captured outdoors is the important step for crop growth monitoring.The commonly used methods for greenness identification are based on visible spectral-index,such as the excess green index,the excess green minus excess red index,the vegetative index,the color index of vegetation extraction,the combined index.All these visible spectral-index based methods are working on the assumption that plants display a clear high degree of greenness,and soil is the only background element.In fact,the brightness and contrast of an image coming from outdoor environments are seriously affected by the weather conditions and the capture time.The color of the plant varies from dark green to bright green.The back ground elements may contain crop straw,straw ash besides soil.These environmental factors always make the visible spectral-index based methods unable to work correctly.In this paper,an HSV decision tree based method for greenness identification from maize seedling images captured outdoors is proposed.Firstly,the image was converted from RGB color space to HSV color space to avoid influence of illumination.Secondly,most of the background pixels were removed according to their hue values compared with the ones of green plants.Thirdly,the pixels of wheat straws whose hue values were intersected with tender green leaves were eliminated subject to their hues,saturations and values.At last,thresholding was employed to get the green plants.The results indicate that the proposed method can recognize greenness pixels correctly from the crop images captured outdoors.展开更多
Dear Editor,The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has rapidly replaced the Delta variant as a dominating SARS-CoV-2 variant because of natural selection,which favors the var...Dear Editor,The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has rapidly replaced the Delta variant as a dominating SARS-CoV-2 variant because of natural selection,which favors the variant with higher infectivity and stronger vaccine breakthrough ability.1 Among three lineages BA.1(B.1.1.529.1),BA.2(B.1.1.529.2),and BA.3(B.1.1.529.3)of Omicron,BA.2 is rising rapidly worldwide since January 2022 and become a new dominating“variant of concern”in China.2 With the current surge in Omicron in China,both the absolute number of children hospitalized with COVID-19 and the percentage of total COVID-19 hospitalizations have been boosting recently.Understanding the clinical characteristics of SARS-CoV-2 Omicron subvariant BA.2 in children and the protective effect of vaccines is of great help for epidemic prevention strategies.However,so far no sufficient experimental data have been reported about infectivity,disease severity,vaccine breakthrough capability,and antibody resistance from pediatric BA.2.展开更多
基金supported by the National Natural Science Foundation of China(22293015,22203099,and 22121002)Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA0390400)Photon Science Center for Carbon Neutrality。
文摘The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).
基金National Natural Science Foundation of China,Grant/Award Numbers:82271784,81974251,82071816National Key Research and Development Program of China,Grant/Award Number:2017YFC0909002。
文摘Background:Immunosuppressive medication reduces the immunogenicity of the coronavirus disease 2019(COVID-19)vaccines in patients with rheumatic and musculoskeletal diseases(RMDs).However,the underlying mechanism remains unclear.The primary aim of our study was to dissect the impact of immunosuppressive medication on cellular and humoral immune responses in RMD patients receiving the inactivated COVID-19 vaccine.Methods:A total of 28 RMD patients and five healthy controls(HCs)receiving two doses of the inactivated COVID-19 vaccine(Sinovac-CoronaVac)were prospectively enrolled.Blood samples were collected before the primary vaccination(Week 0)and one week after the second vaccination(Week 5).Neutralizing antibody(nAb)titers and autoantibody titers were measured by a pseudovirus-based neutralization assay and enzyme-linked immunosorbent assay,respectively.CD4^(+)T-cell and CD19^(+)B-cell subsets and serum cytokines were analyzed by flow cytometry.Results:The inactivated COVID-19 vaccine was immunogenic in RMD patients and HCs after the second vaccination,but the nAb titers were lower in RMD patients than those in HCs.Only patients with systemic lupus erythematosus(SLE)had notably increased nAb titers.Remarkably,IgG^(+)CD27^(+),IgG^(+)IgG1^(+),and IgG^(+)IgG1^(−)B cells were reduced,whereas IgG−IgG1^(+)B cells,and total IgA and IgG titers were markedly increased.However,Tfh cell and Tfr cell subsets and cytokines produced by Tfh cells were not increased.The flare rate was low in RMD patients with comparable autoantibody titers,unchanged CD4^(+)T cell subsets and serum proinflammatory cytokines(interleukin[IL]-6,IL-17,interferon-γ,and tumor necrosis factor-α)after the second vaccination.Conclusions:Immunosuppressive therapy decreased the immunogenicity of the vaccine and maintained a low flare rate by selectively modulating B cell but not CD4^(+)T cell responses in RMD patients receiving the inactivated COVID-19 vaccine.Optimization of the treatment regimen might ensure a durable and robust COVID-19 vaccination response.
基金This work was supported by Fundamental Research and the National Key Projects for Development of China （2018YFB0605802）, the National Natural Science Foundation of China （21425625 ＆ 21506219）, Beijing Natural Science Founda- tion （2182072）, the Research Council of Norway {267615）, and Beijing Hundreds of Leading Talents Training Project of Science and Technology （Z171100001117154）.
文摘The increasing emission of carbon dioxide （CO2） caused by the unrestrained consumption of fossil fuels in recent hundreds of years, has caused global environmental and social problems. Meanwhile, CO2 is a cheap, abundant and renewable Cl-feedstock, which can be converted into alco- hols, ethers, acids and other value-added chemicals. Compared with the thermal reactions, electrochemical reduction of CO2 is more attractive because of its advantages by using the seasonal, geographical and intermittent energy （tide, wind and solar） under mild conditions. In recent years, taking ionic liquids （ILs） as electrolytes in the CO2 electrochemical reduction reaction has been paid much more attention due to the advantages of lowering the overpotential of CO2 electroreduction and improving the Faradaic efficiency. In this paper, we summarized the recent progresses of electrochemical re- duction of CO2 in ILs electrolytes, and analyzed the reaction mechanism of CO2 reaction in the electrode-electrolyte interface region by experimental and simulation methods. Finally, the research which needs to be highlighted in this area was proposed.
基金The authors thank The Ministry of Science and Technology of the People’s Republic of China(2013DFA11320)Hebei Natural Science Foundation(F2015201033),for financial support.
文摘Greenness identification from crop images captured outdoors is the important step for crop growth monitoring.The commonly used methods for greenness identification are based on visible spectral-index,such as the excess green index,the excess green minus excess red index,the vegetative index,the color index of vegetation extraction,the combined index.All these visible spectral-index based methods are working on the assumption that plants display a clear high degree of greenness,and soil is the only background element.In fact,the brightness and contrast of an image coming from outdoor environments are seriously affected by the weather conditions and the capture time.The color of the plant varies from dark green to bright green.The back ground elements may contain crop straw,straw ash besides soil.These environmental factors always make the visible spectral-index based methods unable to work correctly.In this paper,an HSV decision tree based method for greenness identification from maize seedling images captured outdoors is proposed.Firstly,the image was converted from RGB color space to HSV color space to avoid influence of illumination.Secondly,most of the background pixels were removed according to their hue values compared with the ones of green plants.Thirdly,the pixels of wheat straws whose hue values were intersected with tender green leaves were eliminated subject to their hues,saturations and values.At last,thresholding was employed to get the green plants.The results indicate that the proposed method can recognize greenness pixels correctly from the crop images captured outdoors.
基金supported by Shenzhen Science and Technology Research and Development Project(JSGG20200207161928126)Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties(SZGSP011)+2 种基金Guangdong Natural Science Foundation Joint Fund(2019A1515111038)Shenzhen Key Laboratory of Smart Healthcare Engineering(ZDSYS20200811144003009)Shenzhen Longgang District Science and Technology Development Fund Project(LGKCXGZX2020002).
文摘Dear Editor,The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has rapidly replaced the Delta variant as a dominating SARS-CoV-2 variant because of natural selection,which favors the variant with higher infectivity and stronger vaccine breakthrough ability.1 Among three lineages BA.1(B.1.1.529.1),BA.2(B.1.1.529.2),and BA.3(B.1.1.529.3)of Omicron,BA.2 is rising rapidly worldwide since January 2022 and become a new dominating“variant of concern”in China.2 With the current surge in Omicron in China,both the absolute number of children hospitalized with COVID-19 and the percentage of total COVID-19 hospitalizations have been boosting recently.Understanding the clinical characteristics of SARS-CoV-2 Omicron subvariant BA.2 in children and the protective effect of vaccines is of great help for epidemic prevention strategies.However,so far no sufficient experimental data have been reported about infectivity,disease severity,vaccine breakthrough capability,and antibody resistance from pediatric BA.2.
