[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by ga...[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.展开更多
Probiotics have a long history of use in human production and life.With the gradual deepening of the research on the functions of probiotics,their various nutritional and health benefits for the human body have also b...Probiotics have a long history of use in human production and life.With the gradual deepening of the research on the functions of probiotics,their various nutritional and health benefits for the human body have also become increasingly clear.Existing research shows that probiotics can regulate intestinal flora,and improve immunity and even the symptoms of some diseases.Therefore,in the food industry,the application of probiotics from traditional fermented foods to functional foods has become more and more extensive.In this paper,the research progress of nutritional function and application of probiotics in food at home and abroad was reviewed,in order to provide some reference for the safe application of probiotics in food.展开更多
Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymer...Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymerization through sequen-tial addition of vinyl monomers and ethylene oxide(EO).It still remains challenging to achieve altogether high block efficiency,high polymerization efficiency,and high molar mass for PEO.Here,we report a one-pot hybrid block copolymerization approach to polyisoprene/polystyrene(PI/PS)-b-PEO,in which PI/PS are formed by sBuLi-initiated anionic vinyl-addition polymerization,then in situ employed as macroinitiators for the anionic ring-opening polymerization(ROP)of EO aided by an organic Lewis pair.The cooperative(dual-ion-complexing)catalytic effect of organobase and triethylborane is proven,for thefirst time,effective for lithium alkoxide initiator system,allowing to achieve at room temperature high ROP activity(complete EO conversion and PEO of 3–64 kg/mol reached in 1–6 h),narrow molar mass distribution,controlled block lengths and composition.Density functional the-ory calculation shows that phosphazene bases are particularly effective,compared with N-heterocyclic bases,for complexing with Li+and enhancing the nucleophilicity of oxyanion.The rate of ROP is also affected by Li^(+)-induced aggregation of the chain-end ion pairs,which though can be offset by adequate catalyst loadings.The versatility of this approach is further demonstrated in the one-pot synthesis of tri-/tetrablock ter-/quaterpolymers constituted by PI,PS,PEO,and poly(propylene oxide).Of great interest,PS-b-PI-b-PEO triblock terpolymer with a specific com-position is found to form internally microphase-separated micellar aggregates when dispersed in water.展开更多
We propose an in-situ method to calibrate the coil constants of the optical atomic magnetomete. This method is based on measuring the Larmor precession of spin polarized alkali metal atoms and has been demonstrated on...We propose an in-situ method to calibrate the coil constants of the optical atomic magnetomete. This method is based on measuring the Larmor precession of spin polarized alkali metal atoms and has been demonstrated on a K-Rb hybrid atomic magnetomete. Oscillation fields of different frequencies are swept on the transverse coil. By extracting the resonance frequency through phase-frequency analysis of electron spin projection, the coil constants are calibrated to be 323.1±0.28 nT/mA, 108±0.04nT/Ma, and 185.8±1.03 nT/mA along the X,Y, and Z directions, respectively.展开更多
Phenols,in stead of con venti onal alcoholic compounds,are used to in itiate ring-openi ng polymerizati on(ROP)of ethyle neoxide and propyle ne oxide in bulk at room temperature in cooperati on with the recently preva...Phenols,in stead of con venti onal alcoholic compounds,are used to in itiate ring-openi ng polymerizati on(ROP)of ethyle neoxide and propyle ne oxide in bulk at room temperature in cooperati on with the recently prevaili ng bicompone nt metal-free catalyst comprising an organobase and triethylborane.Experimental and DFT calculation results both point out that due to the lower nucleophilicity of the initiating(phe no late)species than the propagating(alcoholate)species,chai n initiat ion is distinctly slower tha n propagation and the difference becomes eve n larger as the acidity of the phe nolic in itiator increases.Nevertheless,we 11-defi ned polyethers with expected molar mass,low dispersity,and high end-group fidelity are afforded substa ntiating that the ROP is living/c on trolled in spite of the slow initiation.Evolution of product composition indicates that the reaction on alcoholates(i.e.,propagation)is effectively inhib-ited by the unreacted phenols during the initiation step because of the adequately large acidity differenee,which is key to the success of the slow-initiation living/controlled polymerization.The acidity difference betwee n phe nol and alcohol also facilitates the fulfill-ment of highly selective phenolysis of epoxides,a"1+1"type addition reaction between phenol and epoxide(in excess)rather than the"1+n"type ROP reaction,by use of a milder organobase and decreased Lewis acid/base ratio.展开更多
Wanquan River is a small river located in Hainan, a tropical island in China. As the third largest river in Hainan, the river plume plays an important role in the regional terrigenous mass transport, coastal circulati...Wanquan River is a small river located in Hainan, a tropical island in China. As the third largest river in Hainan, the river plume plays an important role in the regional terrigenous mass transport, coastal circulation, and the coral reef＇s ecosystem. Studies have shown that wind forcings significantly influence river plume dynamics. In this study, wind effects on the dispersal of the river plume and freshwater transport were examined numerically using a calibrated, unstructured, finite volume numerical model （FVCOM）. Both wind direction and magnitude were determined to influence plume dispersal. Northeasterly （downwelling-favorable） winds drove fresh- water down-shelf while southeasterly （onshore） winds drove water up-shelf （in the sense of Kelvin wave propagation） , and were confined near the coast. Southwesterly （upwelling-favorable） and northwesterly （off： shore） winds transport more freshwater offshore. The transport flux is decomposed into an advection, a vertical shear, and an oscillatory component. The advection flux dominates the freshwater transport in the coastal area and the vertical shear flux is dominant in the offshore area. For the upwelling-favorable wind, the freshwater transport becomes more controlled by the advection transport with an increase in wind stress, due to enhanced vertical mixing. The relative importance of wind forcing and buoyancy force was investigated. It was found that, when the Wedderburn number is larger than one, the plume was dominated by wind forcing, although the importance of wind varies in different parts of the plume. The water column stratification decreased as a whole under the prevailing southwesterly wind, with the exception of the up-shelf and offshore areas.展开更多
Estuaries usually feature complex bathymetries,where shoals and channels are co-existent.Due to the differences in water depth,current,density gradient and therefore stratification,sediment dynamics on the shoal and i...Estuaries usually feature complex bathymetries,where shoals and channels are co-existent.Due to the differences in water depth,current,density gradient and therefore stratification,sediment dynamics on the shoal and in the channel demonstrate significant variations.In this study,field measurements were carried out during spring and neap tides in both wet and dry seasons in the Huangmaohai Estuary,a microtidal estuary located in the southwest of the Pearl River Delta.Harmonic analysis was conducted for the timeseries data of current and suspended sediment concentra-tion(SSC)for each deployment.Sediment transport flux was decomposed into an advective component,and tidal pumping fluxes by different tidal constituents.During the neap tides,sediment transport is primarily controlled by the advective flux,whereas during the spring tides,tidal pumping fluxes become comparable to,sometimes even exceeding,the advective one.For a 25-hr period,the M1 component of SSC usually denotes the maximum SSC associated with the highest bottom stress,while the M2 component signifies the two highs of the SSC.The M4 com-ponent is generally insignificant.The M1 and M2 components can be induced by both the advection and bottom resuspension.For the resuspension part,the M1 component is mostly induced by tidal velocity asymmetry,while the M2 component is generated by tidal straining effect.Sediment transport at the shoal is mostly controlled by the advective flux and the tidal pumping due to tidal velocity asymmetry,while that in the channel is dictated by advec-tive transport and the tidal pumping due to tidal mixing asymmetry.展开更多
Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory fact...Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory factor receptors implicated in SLE.Our study revealed heightened CD132 expression in SLE patients’lymphocytes,contributing to the production of pro-inflammatory cytokines and immunoglobulins.We developed a novel humanized anti-CD132 monoclonal antibody,named as 2D4.2D4 efficiently blocked IL-21 and IL-15,with limited effectiveness against IL-2,thereby suppressing T and B cells without disrupting immune tolerance.In the mouse immunization model,2D4 virtually inhibited T cell-dependent,antigen-specific B-cell response.In lupus murine models,2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers,also diminishing proteinuria and glomerulonephritis.Compared to Belimumab,2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function.Moreover,2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE,highlighting its therapeutic potential for SLE individuals.Potent,2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders.展开更多
基金Supported by The Fourth Batch of High-end Talent Project in Hebei Province.
文摘[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.
基金Supported by The Fourth Batch of High-end Talent Project in Hebei Province.
文摘Probiotics have a long history of use in human production and life.With the gradual deepening of the research on the functions of probiotics,their various nutritional and health benefits for the human body have also become increasingly clear.Existing research shows that probiotics can regulate intestinal flora,and improve immunity and even the symptoms of some diseases.Therefore,in the food industry,the application of probiotics from traditional fermented foods to functional foods has become more and more extensive.In this paper,the research progress of nutritional function and application of probiotics in food at home and abroad was reviewed,in order to provide some reference for the safe application of probiotics in food.
基金National Natural Science Foundation of China,Grant/Award Number:52022031Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates,Grant/Award Number:2023B1212060003Hunan Provincial Natural Science Foundation of China,Grant/Award Number:2023JJ40620。
文摘Polyolefin-b-poly(ethylene oxide)(PEO)represents the most widely investigated amphiphilic block copolymers.So far,one-pot continuous synthesis of such hybrid block copolymers has only been fulfilled by anionic polymerization through sequen-tial addition of vinyl monomers and ethylene oxide(EO).It still remains challenging to achieve altogether high block efficiency,high polymerization efficiency,and high molar mass for PEO.Here,we report a one-pot hybrid block copolymerization approach to polyisoprene/polystyrene(PI/PS)-b-PEO,in which PI/PS are formed by sBuLi-initiated anionic vinyl-addition polymerization,then in situ employed as macroinitiators for the anionic ring-opening polymerization(ROP)of EO aided by an organic Lewis pair.The cooperative(dual-ion-complexing)catalytic effect of organobase and triethylborane is proven,for thefirst time,effective for lithium alkoxide initiator system,allowing to achieve at room temperature high ROP activity(complete EO conversion and PEO of 3–64 kg/mol reached in 1–6 h),narrow molar mass distribution,controlled block lengths and composition.Density functional the-ory calculation shows that phosphazene bases are particularly effective,compared with N-heterocyclic bases,for complexing with Li+and enhancing the nucleophilicity of oxyanion.The rate of ROP is also affected by Li^(+)-induced aggregation of the chain-end ion pairs,which though can be offset by adequate catalyst loadings.The versatility of this approach is further demonstrated in the one-pot synthesis of tri-/tetrablock ter-/quaterpolymers constituted by PI,PS,PEO,and poly(propylene oxide).Of great interest,PS-b-PI-b-PEO triblock terpolymer with a specific com-position is found to form internally microphase-separated micellar aggregates when dispersed in water.
基金support of the National Key R&D Program of China (Grant No. 2017YFB0503100)the National Natural Science Foundation of China (NSFC)(Grant No. 61227902).
文摘We propose an in-situ method to calibrate the coil constants of the optical atomic magnetomete. This method is based on measuring the Larmor precession of spin polarized alkali metal atoms and has been demonstrated on a K-Rb hybrid atomic magnetomete. Oscillation fields of different frequencies are swept on the transverse coil. By extracting the resonance frequency through phase-frequency analysis of electron spin projection, the coil constants are calibrated to be 323.1±0.28 nT/mA, 108±0.04nT/Ma, and 185.8±1.03 nT/mA along the X,Y, and Z directions, respectively.
基金support of the National Natural Science Founda-tion of China(Nos.52022031,21734004,21971075)the Fund of Guangdong Provincial Key Laboratory of Luminescenee from Molecular Aggregates(No.2019B030301003)is acknowledged.
文摘Phenols,in stead of con venti onal alcoholic compounds,are used to in itiate ring-openi ng polymerizati on(ROP)of ethyle neoxide and propyle ne oxide in bulk at room temperature in cooperati on with the recently prevaili ng bicompone nt metal-free catalyst comprising an organobase and triethylborane.Experimental and DFT calculation results both point out that due to the lower nucleophilicity of the initiating(phe no late)species than the propagating(alcoholate)species,chai n initiat ion is distinctly slower tha n propagation and the difference becomes eve n larger as the acidity of the phe nolic in itiator increases.Nevertheless,we 11-defi ned polyethers with expected molar mass,low dispersity,and high end-group fidelity are afforded substa ntiating that the ROP is living/c on trolled in spite of the slow initiation.Evolution of product composition indicates that the reaction on alcoholates(i.e.,propagation)is effectively inhib-ited by the unreacted phenols during the initiation step because of the adequately large acidity differenee,which is key to the success of the slow-initiation living/controlled polymerization.The acidity difference betwee n phe nol and alcohol also facilitates the fulfill-ment of highly selective phenolysis of epoxides,a"1+1"type addition reaction between phenol and epoxide(in excess)rather than the"1+n"type ROP reaction,by use of a milder organobase and decreased Lewis acid/base ratio.
基金This study is funded by the National Natural Science Foundation of China （Grant No. 40976052）. This research is supported in part by Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund （the second phase）. The authors would like to acknowledge Mr. Mac Sisson of Virginia Institute of Marine Science for his help in editing the manuscript. We are also grateful for the three anonymous reviewers for helpful comments on the manuscript.
文摘Wanquan River is a small river located in Hainan, a tropical island in China. As the third largest river in Hainan, the river plume plays an important role in the regional terrigenous mass transport, coastal circulation, and the coral reef＇s ecosystem. Studies have shown that wind forcings significantly influence river plume dynamics. In this study, wind effects on the dispersal of the river plume and freshwater transport were examined numerically using a calibrated, unstructured, finite volume numerical model （FVCOM）. Both wind direction and magnitude were determined to influence plume dispersal. Northeasterly （downwelling-favorable） winds drove fresh- water down-shelf while southeasterly （onshore） winds drove water up-shelf （in the sense of Kelvin wave propagation） , and were confined near the coast. Southwesterly （upwelling-favorable） and northwesterly （off： shore） winds transport more freshwater offshore. The transport flux is decomposed into an advection, a vertical shear, and an oscillatory component. The advection flux dominates the freshwater transport in the coastal area and the vertical shear flux is dominant in the offshore area. For the upwelling-favorable wind, the freshwater transport becomes more controlled by the advection transport with an increase in wind stress, due to enhanced vertical mixing. The relative importance of wind forcing and buoyancy force was investigated. It was found that, when the Wedderburn number is larger than one, the plume was dominated by wind forcing, although the importance of wind varies in different parts of the plume. The water column stratification decreased as a whole under the prevailing southwesterly wind, with the exception of the up-shelf and offshore areas.
基金funded by the National Natural Science Foundation of China(Grant Nos.51761135021,41576089).
文摘Estuaries usually feature complex bathymetries,where shoals and channels are co-existent.Due to the differences in water depth,current,density gradient and therefore stratification,sediment dynamics on the shoal and in the channel demonstrate significant variations.In this study,field measurements were carried out during spring and neap tides in both wet and dry seasons in the Huangmaohai Estuary,a microtidal estuary located in the southwest of the Pearl River Delta.Harmonic analysis was conducted for the timeseries data of current and suspended sediment concentra-tion(SSC)for each deployment.Sediment transport flux was decomposed into an advective component,and tidal pumping fluxes by different tidal constituents.During the neap tides,sediment transport is primarily controlled by the advective flux,whereas during the spring tides,tidal pumping fluxes become comparable to,sometimes even exceeding,the advective one.For a 25-hr period,the M1 component of SSC usually denotes the maximum SSC associated with the highest bottom stress,while the M2 component signifies the two highs of the SSC.The M4 com-ponent is generally insignificant.The M1 and M2 components can be induced by both the advection and bottom resuspension.For the resuspension part,the M1 component is mostly induced by tidal velocity asymmetry,while the M2 component is generated by tidal straining effect.Sediment transport at the shoal is mostly controlled by the advective flux and the tidal pumping due to tidal velocity asymmetry,while that in the channel is dictated by advec-tive transport and the tidal pumping due to tidal mixing asymmetry.
基金supported by following fundings:the National Key R&D Program of China(No.2022YFC3601800)the CAMS Innovation Fund for Medical Sciences(No.2021-I2M-1-059)+4 种基金non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.2021-RC320-001,No.2020-RC320-003)the Special Program of National Natural Science Foundation of China(NO.32141004)the Special Research Fund for Central Universities,Peking Union Medical College(No.3332023075)Natural Science Foundation of Jiangsu Province(No.BK20230130)National Natural Science Foundation of China(No.82302982).
文摘Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness.To address this limitation,our focus was on CD132,a subunit common to six inflammatory factor receptors implicated in SLE.Our study revealed heightened CD132 expression in SLE patients’lymphocytes,contributing to the production of pro-inflammatory cytokines and immunoglobulins.We developed a novel humanized anti-CD132 monoclonal antibody,named as 2D4.2D4 efficiently blocked IL-21 and IL-15,with limited effectiveness against IL-2,thereby suppressing T and B cells without disrupting immune tolerance.In the mouse immunization model,2D4 virtually inhibited T cell-dependent,antigen-specific B-cell response.In lupus murine models,2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers,also diminishing proteinuria and glomerulonephritis.Compared to Belimumab,2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function.Moreover,2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE,highlighting its therapeutic potential for SLE individuals.Potent,2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders.
