Catalytic oxidation of formaldehyde (HCHO) is the most efficient way to purify indoor air of HCHO pollutant. This work investigated rare earth La‐doped Pt/TiO2 for low concentration HCHO oxidation at room temperature...Catalytic oxidation of formaldehyde (HCHO) is the most efficient way to purify indoor air of HCHO pollutant. This work investigated rare earth La‐doped Pt/TiO2 for low concentration HCHO oxidation at room temperature. La‐doped Pt/TiO2 had a dramatically promoted catalytic performance for HCHO oxidation. The reasons for the La promotion effect were investigated by N2 adsorption, X‐raydiffraction, CO chemisorption, X‐ray photoelectron spectroscopy, transmission electron microscopy(TEM) and high‐angle annular dark field scanning TEM. The Pt nanoparticle size was reduced to 1.7nm from 2.2 nm after modification by La, which led to higher Pt dispersion, more exposed activesites and enhanced metal‐support interaction. Thus a superior activity for indoor low concentrationHCHO oxidation was obtained. Moreover, the La‐doped TiO2 can be wash‐coated on a cordieritemonolith so that very low amounts of Pt (0.01 wt%) can be used. The catalyst was evaluated in asimulated indoor HCHO elimination environment and displayed high purifying efficiency and stability.It can be potentially used as a commercial catalyst for indoor HCHO elimination.展开更多
Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two ...Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two major greenhouse gases into value-added syngas or hydrogen.The main problem retarding its industrialization is the seriously coking formation upon the nickel-based catalysts.Herein,a series of confined indium-nickel(In-Ni)intermetallic alloy nanocatalysts(In_(x)Ni@SiO_(2))have been prepared and displayed superior coking resistance for DRM reaction.The sample containing 0.5 wt.%of In loading(In_(0.5)Ni@SiO_(2))shows the best balance of carbon deposition resistance and DRM reactivity even after 430 h long term stability test.The boosted carbon resistance can be ascribed to the confinement of core–shell structure and to the transfer of electrons from Indium to Nickel in In-Ni intermetallic alloys due to the smaller electronegativity of In.Both the silica shell and the increase of electron cloud density on metallic Ni can weaken the ability of Ni to activate C–H bond and decrease the deep cracking process of methane.The reaction over the confined InNi intermetallic alloy nanocatalyst was conformed to the Langmuir-Hinshelwood(L-H)mechanism revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS).This work provides a guidance to design high performance coking resistance catalysts for methane dry reforming to efficiently utilize these two main greenhouse gases.展开更多
In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)cata...In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.展开更多
A series of Ni/La2Zr2O7 pyrochlore catalysts prepared by impregnation method and treated by dielectric barrier discharge（DBD） plasma in different atmospheres and varied sequences were prepared and applied for dry re...A series of Ni/La2Zr2O7 pyrochlore catalysts prepared by impregnation method and treated by dielectric barrier discharge（DBD） plasma in different atmospheres and varied sequences were prepared and applied for dry reforming of methane（DRM）. It is found that all of the plasma treated catalysts show evidently improved activity and coke resistance in comparison with the non-plasma treated one. The best performance is achieved on Ni/La2Zr2O7–H2P–C,a catalyst treated in H2 plasma before calcination. TGA-DSC and SEM demonstrate that carbon deposition is significantly suppressed on all of the plasma treated samples. Moreover,XRD and TEM results testify that both Ni O and Ni sizes on the calcined and reduced samples treated by plasma are also decreased,which results in higher Ni metal dispersion on the reduced and used catalysts and enhances the interactions between Ni sites and the support. It is believed that these are the inherent reasons accounting for the promotional effects of plasma treatment on the reaction performance of the Ni/La2Zr2O7 pyrochlore catalysts.展开更多
In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-...In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-TPR that plasma treatment can enhance the interaction between Ni O/Ni particles and the YZrOpyrochlore support. Therefore, catalysts with smaller Ni O and Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD, TEM and Hadsorption-desorption measurements. As a consequence, the plasma-treated catalysts show significantly improved activity, stability and coke resistance, as testified by the TEM and TGA-DSC results. Plasma treatment in H/Ar gas mixture is found to be the best condition to prepare Ni/YZrO, which can be used to obtain a catalyst with the highest activity, stability and most potent coke resistance. It is believed that the smaller Ni grain size and higher metallic Ni active surface area induced by plasma treatment are the inherent reasons accounting for the promoted reaction performance of the Ni/YZrOpyrochlore catalysts.展开更多
Integrated Project Delivery(IPD)is a new delivery system that fosters integration of combining design and construction in a collaborative team environment.Building Information Modeling(BIM)is a smart technological too...Integrated Project Delivery(IPD)is a new delivery system that fosters integration of combining design and construction in a collaborative team environment.Building Information Modeling(BIM)is a smart technological tool that make significant advancements in coordinating the planning and construction processes.IPD process with BIM technology allows all building data to maintain in a communicating platform that make all participants share data.In reality,some technical and process obstacles exist,that are hampering full implementation of IPD with BIM in the project.The paper introduced the application of IPD with BIM on the design in a project.The results showed the impact of BIM implementation on IPD mode which can result in improved productivity,better coordination,reduced energy consumption,clash and rework of construction.展开更多
The upper respiratory tract is the initial site of SARS-CoV-2 infection.Nasal spike-specific secretory immunoglobulin A(slgA)correlates with protection against Omicron breakthrough infection.We report that intranasal ...The upper respiratory tract is the initial site of SARS-CoV-2 infection.Nasal spike-specific secretory immunoglobulin A(slgA)correlates with protection against Omicron breakthrough infection.We report that intranasal vaccination using human adenovirus serotype 5(Ad5)vectored Omicron spike in people who previously vaccinated with ancestral vaccine could induce robust neutralizing slgA in the nasal passage.Nasal slgA was predominantly present in dimeric and multimeric forms and accounted for nearly 40%of total proteins in nasal mucosal lining fluids(NMLFs).A low-level IgG could also be detected in NMLFs but not IgM,IgD,and IgE.After a complete nasal wash,slgA in the nasal passage could be replenished rapidly within a few hours.A comparison of purified paired serum IgA,serum IgG,and nasal slgA from the same individuals showed that slgA was up to 3-logs more potent than serum antibodies in binding to spikes and in neutralizing Omicron subvariants.Serum IgG and IgA failed to neutralize XBB and BA.2.86,while nasal slgA retained potent neutralization against these newly emerged variants.Further analysis showed that slgA Was more effective than IgG or IgA in blocking spike-mediated cell-to-cell transmission and protecting hACE2 mice from XBB challenge.Using a slgA monoclonal antibody as a reference,we estimated that the total nasal slgA contains about 2.6-3.9%spikespecific slgA in NMLFs collected approximately one month after intranasal vaccination.Our study provided insights for developing intranasal vaccines that can induce slgA to build an effective and mutation-resistant first-line immune barrier against constantly emerging variants.展开更多
With the objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rare earth A sites have been pre...With the objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rare earth A sites have been prepared by a co-precipitation method. XRD and Raman have proved that pure Ln2Zr2O7 compounds have been successfully prepared for all the catalysts. By decreasing the rA/rB ratio, their crystalline structure transform from an ordered pyrochlore (La2Zr2O7) to a less ordered pyrochlore (Pr2Zr2O7 and Sm2Zr2O7) and eventually to a defective cubic fluorite phase (Y2Zr2O7). H2-TPR, O2-TPD and XPS have testified that the amount of surface active O2-species follows the order of La2Zr2O7>Pr2Zr2O7>Sm2Zr2O7 > Y2Zr2O7, which is well consistent with the reaction performance, indicating that the abundance of surface O2- sites is a critical factor influencing the reaction performance. CO2-TPD has demonstrated that a better catalyst generally possesses a larger amount of surface moderate alkaline sites, which is another factor to affect the reaction performance. It is concluded that the concerted interaction between the two types of surface active sites controls the reaction performance of the Ln2Zr2O7 catalysts. In comparison with the state-of-the art Mn/Na2WO4/SiO2, La2Zr2O7, the best catalyst, exhibits much improved reaction performance below 750 ℃.展开更多
Early detection of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection is an efficient way to prevent the spread of coronavirus disease 2019(COVID-19).Detecting SARS-CoV-2 antigen can be rapid and con...Early detection of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection is an efficient way to prevent the spread of coronavirus disease 2019(COVID-19).Detecting SARS-CoV-2 antigen can be rapid and convenient,but it is still challenging to develop highly sensitive methods for effective diagnosis.Herein,a lateral flow assay(LFA)based on fluorescent nanoparticles emitting in the second near-infrared(NIR-II)window is developed for sensitive detection of SARS-CoV-2 antigen.Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence,such NIR-II based LFA allows enhanced signal-to-background ratio,and the limit of detection is down to 0.01 ng·mL^(−1)of SARS-CoV-2 antigen.In the clinical swab sample tests,the NIR-II LFA outperforms the colloidal gold LFA with higher overall percent agreement with the polymerase chain reaction test.The clinical samples with low antigen concentrations(~0.015–~0.068 ng·mL^(−1))can be successfully detected by the NIR-II LFA,but fail for the colloidal gold LFA.The NIR-II LFA can provide a promising platform for highly sensitive,rapid,and cost-effective method for early diagnosis and mass screening of SARS-CoV-2 infection.展开更多
This study presents new numerical drag models with which to analyze the sensitivity of mesoscale structural parameters in bubbling,turbulent,and circulating fluidized beds.The drag models are derived using the method ...This study presents new numerical drag models with which to analyze the sensitivity of mesoscale structural parameters in bubbling,turbulent,and circulating fluidized beds.The drag models are derived using the method of transfer-coefficient-based structural parameters(TC-SP).Analyzing the sensitivity of the structural parameters reveals that the coefficients associated with drag are more sensitive to parameters in the dense phase than to those in the dilute phase,especially the superficial slip velocity.On the basis of these results,the TC-SP drag model is simplified further.Interestingly,despite having half the number of parameters of conventional structure-based drag models,the simplified TC-SP drag model achieves simulation results that are equally or more accurate.With simple calculations and improved accuracy using coarse grids,the model reported in this study is capable of predicting the hydrodynamics of the three types of fluidized beds.展开更多
Microfluidic devices, as a new miniaturized platform stemming from the field of micro-electromechanical sys-tems, have been used in many disciplines. In the field of chemical reactions, microfluidic device-based micro...Microfluidic devices, as a new miniaturized platform stemming from the field of micro-electromechanical sys-tems, have been used in many disciplines. In the field of chemical reactions, microfluidic device-based microreac-tors have shown great promise in building new chemical technologies and processes with increased speed and reli- ability and reduced sample consumption and cost. This technology has also become a new and effective tool for precise, high-throughput, and automatic analysis of chemical synthesis processes. Compared with conventional chemical laboratory batch methodologies, microfluidic reactors have a number of features, such as high mixing ef- ficiency, short reaction time, high heat-transfer coefficient, small reactant volume, controllable residence time, and high surface-to-volume ratio, among others. Combined with recent advances in microfluidic devices for chemical reactions, this review aims to give an overview of the features and applications of microfluidic devices in the field of chemical synthesis. It also aims to stimulate the development of microfluidic device applications in the field of chemical reactions.展开更多
Human adenoviruses type 26(HAdV26)and type 35(HAdV35)have increasingly become the choice of adenovirus vectors for vaccine application.However,the population pre-existing immunity to these two adenoviruses in China,wh...Human adenoviruses type 26(HAdV26)and type 35(HAdV35)have increasingly become the choice of adenovirus vectors for vaccine application.However,the population pre-existing immunity to these two adenoviruses in China,which may reduce vaccine efficacy,remains largely unknown.Here,we established micro-neutralizing(MN)assays to investigate the seroprevalence of neutralizing antibodies(nAbs)against HAdV26 and HAdV35 in the general population of Guangdong and Shandong provinces,China.A total of 1184 serum samples were collected,47.0%and 15.8%of which showed HAdV26 and HAdV35 nAb activity,respectively.HAdV26-seropositive individuals tended to have more moderate nAbs titers(201-1000),while HAdV35-seropositive individuals appeared to have more low nAbs titers(72-200).The seropositive rates of HAdV26 and HAdV35 in individuals younger than 20 years old were very low.The seropositive rates of HAdV26 increased with age before 70 years old and decreased thereafter,while HAdV35 seropositive rates did not show similar characteristics.Notably,the seropositive rates and nAb levels of both HAdV26 and HAdV35 were higher in Guangdong Province than in Shandong Province,but did not exert significant differences between males and females.The seroprevalence between HAdV26 and HAdV35 showed little correlation,and no significant cross-neutralizing activity was detected.These results clarified the characteristics of the herd immunity against HAdV26 and HAdV35,and provided information for the rational development and application of HAdV26 and HAdV35 as vaccine vectors in China.展开更多
基金supported by the National Key Research and Development Program (2016YFC0205900)the National Natural Science Foundation of China (21503106, 21567016)+1 种基金the Education Department of Jiangxi Province (KJLD14005)the Natural Science Foundation of Jiangxi Province (20142BAB213013 and 20151BBE50006)~~
文摘Catalytic oxidation of formaldehyde (HCHO) is the most efficient way to purify indoor air of HCHO pollutant. This work investigated rare earth La‐doped Pt/TiO2 for low concentration HCHO oxidation at room temperature. La‐doped Pt/TiO2 had a dramatically promoted catalytic performance for HCHO oxidation. The reasons for the La promotion effect were investigated by N2 adsorption, X‐raydiffraction, CO chemisorption, X‐ray photoelectron spectroscopy, transmission electron microscopy(TEM) and high‐angle annular dark field scanning TEM. The Pt nanoparticle size was reduced to 1.7nm from 2.2 nm after modification by La, which led to higher Pt dispersion, more exposed activesites and enhanced metal‐support interaction. Thus a superior activity for indoor low concentrationHCHO oxidation was obtained. Moreover, the La‐doped TiO2 can be wash‐coated on a cordieritemonolith so that very low amounts of Pt (0.01 wt%) can be used. The catalyst was evaluated in asimulated indoor HCHO elimination environment and displayed high purifying efficiency and stability.It can be potentially used as a commercial catalyst for indoor HCHO elimination.
基金supported by the National Natural Science Foundation of China(21976078 and 21773106)the National Key R&D Program of China(2016YFC0205900)+1 种基金the Natural Science Foundation of Jiangxi Province(20202ACB213001)National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2019A12)。
文摘Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two major greenhouse gases into value-added syngas or hydrogen.The main problem retarding its industrialization is the seriously coking formation upon the nickel-based catalysts.Herein,a series of confined indium-nickel(In-Ni)intermetallic alloy nanocatalysts(In_(x)Ni@SiO_(2))have been prepared and displayed superior coking resistance for DRM reaction.The sample containing 0.5 wt.%of In loading(In_(0.5)Ni@SiO_(2))shows the best balance of carbon deposition resistance and DRM reactivity even after 430 h long term stability test.The boosted carbon resistance can be ascribed to the confinement of core–shell structure and to the transfer of electrons from Indium to Nickel in In-Ni intermetallic alloys due to the smaller electronegativity of In.Both the silica shell and the increase of electron cloud density on metallic Ni can weaken the ability of Ni to activate C–H bond and decrease the deep cracking process of methane.The reaction over the confined InNi intermetallic alloy nanocatalyst was conformed to the Langmuir-Hinshelwood(L-H)mechanism revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS).This work provides a guidance to design high performance coking resistance catalysts for methane dry reforming to efficiently utilize these two main greenhouse gases.
文摘In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.
基金supported by the Chinese Natural Science Foundation (21263015 and 21203088)the Education Department of Jiangxi Province (KJLD14005 and GJJ14205)the Natural Science Foundation of Jiangxi Province (20142BAB213013)
文摘A series of Ni/La2Zr2O7 pyrochlore catalysts prepared by impregnation method and treated by dielectric barrier discharge（DBD） plasma in different atmospheres and varied sequences were prepared and applied for dry reforming of methane（DRM）. It is found that all of the plasma treated catalysts show evidently improved activity and coke resistance in comparison with the non-plasma treated one. The best performance is achieved on Ni/La2Zr2O7–H2P–C,a catalyst treated in H2 plasma before calcination. TGA-DSC and SEM demonstrate that carbon deposition is significantly suppressed on all of the plasma treated samples. Moreover,XRD and TEM results testify that both Ni O and Ni sizes on the calcined and reduced samples treated by plasma are also decreased,which results in higher Ni metal dispersion on the reduced and used catalysts and enhances the interactions between Ni sites and the support. It is believed that these are the inherent reasons accounting for the promotional effects of plasma treatment on the reaction performance of the Ni/La2Zr2O7 pyrochlore catalysts.
基金supported by the National Natural Science Foundation of China (21567016, 21566022, 21263015)the Natural Science Foundation of Jiangxi Province (20151BBE50006, 20151BAB203024)the Education Department of Jiangxi Province (KJLD14005, GJJ150016)
文摘In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-TPR that plasma treatment can enhance the interaction between Ni O/Ni particles and the YZrOpyrochlore support. Therefore, catalysts with smaller Ni O and Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD, TEM and Hadsorption-desorption measurements. As a consequence, the plasma-treated catalysts show significantly improved activity, stability and coke resistance, as testified by the TEM and TGA-DSC results. Plasma treatment in H/Ar gas mixture is found to be the best condition to prepare Ni/YZrO, which can be used to obtain a catalyst with the highest activity, stability and most potent coke resistance. It is believed that the smaller Ni grain size and higher metallic Ni active surface area induced by plasma treatment are the inherent reasons accounting for the promoted reaction performance of the Ni/YZrOpyrochlore catalysts.
基金the support by the Housing and Urban-Rural Development Department of Shandong Province“specific topic”(No.2020-K1-7).
文摘Integrated Project Delivery(IPD)is a new delivery system that fosters integration of combining design and construction in a collaborative team environment.Building Information Modeling(BIM)is a smart technological tool that make significant advancements in coordinating the planning and construction processes.IPD process with BIM technology allows all building data to maintain in a communicating platform that make all participants share data.In reality,some technical and process obstacles exist,that are hampering full implementation of IPD with BIM in the project.The paper introduced the application of IPD with BIM on the design in a project.The results showed the impact of BIM implementation on IPD mode which can result in improved productivity,better coordination,reduced energy consumption,clash and rework of construction.
基金The study was supported by the National Natural Science Foundation(92269201)Youth Innovation Promotion Association of CAS(2022361)+2 种基金Grants from Guangzhou National Laboratory(GZNL2024A01012,GZNL2023A01009)State Key Laboratory of Respiratory Disease(SKLRD-Z-202106,SKLRD-Z-202328)Science and Technology Projects in Guangzhou(SL2022A04J00604).
文摘The upper respiratory tract is the initial site of SARS-CoV-2 infection.Nasal spike-specific secretory immunoglobulin A(slgA)correlates with protection against Omicron breakthrough infection.We report that intranasal vaccination using human adenovirus serotype 5(Ad5)vectored Omicron spike in people who previously vaccinated with ancestral vaccine could induce robust neutralizing slgA in the nasal passage.Nasal slgA was predominantly present in dimeric and multimeric forms and accounted for nearly 40%of total proteins in nasal mucosal lining fluids(NMLFs).A low-level IgG could also be detected in NMLFs but not IgM,IgD,and IgE.After a complete nasal wash,slgA in the nasal passage could be replenished rapidly within a few hours.A comparison of purified paired serum IgA,serum IgG,and nasal slgA from the same individuals showed that slgA was up to 3-logs more potent than serum antibodies in binding to spikes and in neutralizing Omicron subvariants.Serum IgG and IgA failed to neutralize XBB and BA.2.86,while nasal slgA retained potent neutralization against these newly emerged variants.Further analysis showed that slgA Was more effective than IgG or IgA in blocking spike-mediated cell-to-cell transmission and protecting hACE2 mice from XBB challenge.Using a slgA monoclonal antibody as a reference,we estimated that the total nasal slgA contains about 2.6-3.9%spikespecific slgA in NMLFs collected approximately one month after intranasal vaccination.Our study provided insights for developing intranasal vaccines that can induce slgA to build an effective and mutation-resistant first-line immune barrier against constantly emerging variants.
基金the Natural Science Foundation of China (Nos. 21567016, 21566022, 21666020)the Natural Science Foundation of Jiangxi Province (Nos. 20181ACB20005, 20171BAB213013 and 20181BAB203017)+4 种基金the Key Laboratory Foundation of Jiangxi Province for Environment and Energy Catalysis(No. 20181BCD40004) the Education Department of Jiangxi Province (Nos. GJJ150016, GJJ150085 and KJLD14005)the China Postdoctoral Science Foundation(No. 2018M631294)Innovation Fund Designated for Undergraduate Students of Nanchang University of China (No. 201802369)the Graduate Student Creativity Funding of Nanchang University(No. 201802062)
文摘With the objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rare earth A sites have been prepared by a co-precipitation method. XRD and Raman have proved that pure Ln2Zr2O7 compounds have been successfully prepared for all the catalysts. By decreasing the rA/rB ratio, their crystalline structure transform from an ordered pyrochlore (La2Zr2O7) to a less ordered pyrochlore (Pr2Zr2O7 and Sm2Zr2O7) and eventually to a defective cubic fluorite phase (Y2Zr2O7). H2-TPR, O2-TPD and XPS have testified that the amount of surface active O2-species follows the order of La2Zr2O7>Pr2Zr2O7>Sm2Zr2O7 > Y2Zr2O7, which is well consistent with the reaction performance, indicating that the abundance of surface O2- sites is a critical factor influencing the reaction performance. CO2-TPD has demonstrated that a better catalyst generally possesses a larger amount of surface moderate alkaline sites, which is another factor to affect the reaction performance. It is concluded that the concerted interaction between the two types of surface active sites controls the reaction performance of the Ln2Zr2O7 catalysts. In comparison with the state-of-the art Mn/Na2WO4/SiO2, La2Zr2O7, the best catalyst, exhibits much improved reaction performance below 750 ℃.
基金Guangdong Provincial Department of Science and Technology-key research and development project(No.2020B1111160003)Shenzhen Science and Technology Innovation Commission technology breakthrough project(No.JSGG20191231141403880)+1 种基金Shenzhen San-Ming Project(No.SZSM201809085)Shenzhen Science and Technology Innovation Commission general project(No.JCYJ20180504165657443)。
文摘Early detection of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection is an efficient way to prevent the spread of coronavirus disease 2019(COVID-19).Detecting SARS-CoV-2 antigen can be rapid and convenient,but it is still challenging to develop highly sensitive methods for effective diagnosis.Herein,a lateral flow assay(LFA)based on fluorescent nanoparticles emitting in the second near-infrared(NIR-II)window is developed for sensitive detection of SARS-CoV-2 antigen.Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence,such NIR-II based LFA allows enhanced signal-to-background ratio,and the limit of detection is down to 0.01 ng·mL^(−1)of SARS-CoV-2 antigen.In the clinical swab sample tests,the NIR-II LFA outperforms the colloidal gold LFA with higher overall percent agreement with the polymerase chain reaction test.The clinical samples with low antigen concentrations(~0.015–~0.068 ng·mL^(−1))can be successfully detected by the NIR-II LFA,but fail for the colloidal gold LFA.The NIR-II LFA can provide a promising platform for highly sensitive,rapid,and cost-effective method for early diagnosis and mass screening of SARS-CoV-2 infection.
基金The authors are grateful to the financial support from National Natural Science Foundation of Chinaunder GrantNo.21325628 and from the State Key Development Program for Basic Researchof China(973 Program)under Grant 2015CB251402.
文摘This study presents new numerical drag models with which to analyze the sensitivity of mesoscale structural parameters in bubbling,turbulent,and circulating fluidized beds.The drag models are derived using the method of transfer-coefficient-based structural parameters(TC-SP).Analyzing the sensitivity of the structural parameters reveals that the coefficients associated with drag are more sensitive to parameters in the dense phase than to those in the dilute phase,especially the superficial slip velocity.On the basis of these results,the TC-SP drag model is simplified further.Interestingly,despite having half the number of parameters of conventional structure-based drag models,the simplified TC-SP drag model achieves simulation results that are equally or more accurate.With simple calculations and improved accuracy using coarse grids,the model reported in this study is capable of predicting the hydrodynamics of the three types of fluidized beds.
基金The present work was supported by the National Natural Science Foundation of China （Nos. 21175107, 20975082 and 31100726）, the Ministry of Education of the People＇s Republic of China （No. NCET-08-0464）, the State Forestry Administration of the People＇s Re-public of China （No. 200904004）, the Scientific Re-search Foundation for the Returned Overseas Chinese Scholars of the State Education Ministry, and Northwest A＆F University.
文摘Microfluidic devices, as a new miniaturized platform stemming from the field of micro-electromechanical sys-tems, have been used in many disciplines. In the field of chemical reactions, microfluidic device-based microreac-tors have shown great promise in building new chemical technologies and processes with increased speed and reli- ability and reduced sample consumption and cost. This technology has also become a new and effective tool for precise, high-throughput, and automatic analysis of chemical synthesis processes. Compared with conventional chemical laboratory batch methodologies, microfluidic reactors have a number of features, such as high mixing ef- ficiency, short reaction time, high heat-transfer coefficient, small reactant volume, controllable residence time, and high surface-to-volume ratio, among others. Combined with recent advances in microfluidic devices for chemical reactions, this review aims to give an overview of the features and applications of microfluidic devices in the field of chemical synthesis. It also aims to stimulate the development of microfluidic device applications in the field of chemical reactions.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB29050701)the Emergency Key Program of Guangzhou (EKPG21-20)+2 种基金the China Evergrande Group funding for SARS-Co V-2 (2020GIRHHMS22)the Zhongnanshan Medical Foundation of Guangdong Province (ZNSA-2022009)the China Postdoctoral Science Foundation (2020M682942)
文摘Human adenoviruses type 26(HAdV26)and type 35(HAdV35)have increasingly become the choice of adenovirus vectors for vaccine application.However,the population pre-existing immunity to these two adenoviruses in China,which may reduce vaccine efficacy,remains largely unknown.Here,we established micro-neutralizing(MN)assays to investigate the seroprevalence of neutralizing antibodies(nAbs)against HAdV26 and HAdV35 in the general population of Guangdong and Shandong provinces,China.A total of 1184 serum samples were collected,47.0%and 15.8%of which showed HAdV26 and HAdV35 nAb activity,respectively.HAdV26-seropositive individuals tended to have more moderate nAbs titers(201-1000),while HAdV35-seropositive individuals appeared to have more low nAbs titers(72-200).The seropositive rates of HAdV26 and HAdV35 in individuals younger than 20 years old were very low.The seropositive rates of HAdV26 increased with age before 70 years old and decreased thereafter,while HAdV35 seropositive rates did not show similar characteristics.Notably,the seropositive rates and nAb levels of both HAdV26 and HAdV35 were higher in Guangdong Province than in Shandong Province,but did not exert significant differences between males and females.The seroprevalence between HAdV26 and HAdV35 showed little correlation,and no significant cross-neutralizing activity was detected.These results clarified the characteristics of the herd immunity against HAdV26 and HAdV35,and provided information for the rational development and application of HAdV26 and HAdV35 as vaccine vectors in China.
