Photocatalytic O_(2)activation to generate reactive oxygen species is crucially important for purifying organic pollutants,yet remains a challenge due to poor adsorption of O_(2)and low efficiency of electron transfer...Photocatalytic O_(2)activation to generate reactive oxygen species is crucially important for purifying organic pollutants,yet remains a challenge due to poor adsorption of O_(2)and low efficiency of electron transfer.Herein,we demonstrate that ultrafine MoO_(x)clusters anchored on graphitic carbon nitride(g-C_(3)N_(4))with dual nitrogen/oxygen defects promote the photocatalytic activation of O_(2)to generate·O_(2)−for the degradation of tetracycline hydrochloride(TCH).A range of characterization techniques and density functional theory(DFT)calculations reveal that the introduction of the nitrogen/oxygen dual defects and MoO_(x)clusters enhances the O_(2)adsorption energy from−2.77 to−2.94 eV.We find that MoO_(x)clusters with oxygen vacancies(Ov)and surface Ov-mediated Moδ+(3≥δ≥2)possess unpaired localized electrons,which act as electron capture centers to transfer electrons to the MoO_(x)clusters.These electrons can then transfer to the surface adsorbed O_(2),thus promoting the photocatalytic conversion of O_(2)to·O_(2)−and,simultaneously,realizing the efficient separation of photogenerated electron–hole pairs.Our fully-optimized MoO_(x)/g-C_(3)N_(4)catalyst with dual nitrogen/oxygen defects manifests outstanding photoactivities,achieving 79%degradation efficiency toward TCH within 120 min under visible light irradiation,representing nearly 7 times higher activity than pristine g-C_(3)N_(4).Finally,based on the results of liquid chromatograph mass spectrometry and DFT calculations,the possible photocatalytic degradation pathways of TCH were proposed.展开更多
Circulating tumor DNA(ctDNA)is a critical biomarker not only important for the early detection of tumors but also invaluable for personalized treatments.Currently ctDNA detection relies on sequencing.Here,a platform t...Circulating tumor DNA(ctDNA)is a critical biomarker not only important for the early detection of tumors but also invaluable for personalized treatments.Currently ctDNA detection relies on sequencing.Here,a platform termed three-dimensional-coded interlocked DNA rings(3D-coded ID rings)was created for multiplexed ctDNA identification.The ID rings provide a ctDNA recognition ring that is physically interlocked with a reporter ring.The specific binding of ctDNA to the recognition ring initiates target-responsive cutting via a restriction endonuclease;the cutting then triggers rolling circle amplification on the reporter ring.The signals are further integrated with internal 3D codes for multiplexed readouts.ctDNAs from non-invasive clinical specimens including plasma,feces,and urine were detected and validated at a sensitivity much higher than those obtained through sequencing.This 3D-coded ID ring platform can detect any multiple DNA fragments simultaneously without sequencing.We envision that our platform will facilitate the implementation of future personalized/precision medicine.展开更多
Empirical study using a time-varying parameter model indicates that since the reform and opening up of China,its industrial structure upgrade has had an increasingly significant stabilizing effect on the amplitude of ...Empirical study using a time-varying parameter model indicates that since the reform and opening up of China,its industrial structure upgrade has had an increasingly significant stabilizing effect on the amplitude of economic fluctuations.A further analysis using a TGARCH model reveals that the three major industrial sectors have asymmetrical effects on the size of macroeconomic fluctuation:the primary industry(extraction)has little effect;the secondary industry(manufacturing)has a leverage effect mainly caused by heavy industry;the tertiary industry(services)has a clear stabilizing effect,with the effect of transportation,logistics,the postal industry,housing-catering services,and other service industries being most significant,and the effect of wholesale,retail,the finance industry and real estate being less significant due to their own large fluctuations.The policy implications of the findings are that to maintain stable growth in the economy,China should optimize the relations of the three major industrial sectors,and further push for the upgrading of the industrial structure,especially the development of the tertiary industry.展开更多
基金supported by the National Natural Science Foundation of China(No.21972010)the National Key Research and Development Program of China(No.2022YFC2105900).
文摘Photocatalytic O_(2)activation to generate reactive oxygen species is crucially important for purifying organic pollutants,yet remains a challenge due to poor adsorption of O_(2)and low efficiency of electron transfer.Herein,we demonstrate that ultrafine MoO_(x)clusters anchored on graphitic carbon nitride(g-C_(3)N_(4))with dual nitrogen/oxygen defects promote the photocatalytic activation of O_(2)to generate·O_(2)−for the degradation of tetracycline hydrochloride(TCH).A range of characterization techniques and density functional theory(DFT)calculations reveal that the introduction of the nitrogen/oxygen dual defects and MoO_(x)clusters enhances the O_(2)adsorption energy from−2.77 to−2.94 eV.We find that MoO_(x)clusters with oxygen vacancies(Ov)and surface Ov-mediated Moδ+(3≥δ≥2)possess unpaired localized electrons,which act as electron capture centers to transfer electrons to the MoO_(x)clusters.These electrons can then transfer to the surface adsorbed O_(2),thus promoting the photocatalytic conversion of O_(2)to·O_(2)−and,simultaneously,realizing the efficient separation of photogenerated electron–hole pairs.Our fully-optimized MoO_(x)/g-C_(3)N_(4)catalyst with dual nitrogen/oxygen defects manifests outstanding photoactivities,achieving 79%degradation efficiency toward TCH within 120 min under visible light irradiation,representing nearly 7 times higher activity than pristine g-C_(3)N_(4).Finally,based on the results of liquid chromatograph mass spectrometry and DFT calculations,the possible photocatalytic degradation pathways of TCH were proposed.
基金supported by the National Natural Science Foundation of China(Grant No.81972027,82030066,82122042,81430053).
文摘Circulating tumor DNA(ctDNA)is a critical biomarker not only important for the early detection of tumors but also invaluable for personalized treatments.Currently ctDNA detection relies on sequencing.Here,a platform termed three-dimensional-coded interlocked DNA rings(3D-coded ID rings)was created for multiplexed ctDNA identification.The ID rings provide a ctDNA recognition ring that is physically interlocked with a reporter ring.The specific binding of ctDNA to the recognition ring initiates target-responsive cutting via a restriction endonuclease;the cutting then triggers rolling circle amplification on the reporter ring.The signals are further integrated with internal 3D codes for multiplexed readouts.ctDNAs from non-invasive clinical specimens including plasma,feces,and urine were detected and validated at a sensitivity much higher than those obtained through sequencing.This 3D-coded ID ring platform can detect any multiple DNA fragments simultaneously without sequencing.We envision that our platform will facilitate the implementation of future personalized/precision medicine.
基金supported by the National Social Science Foundation of China(Grant Nos.:11AZD037 and 12CJL016)
文摘Empirical study using a time-varying parameter model indicates that since the reform and opening up of China,its industrial structure upgrade has had an increasingly significant stabilizing effect on the amplitude of economic fluctuations.A further analysis using a TGARCH model reveals that the three major industrial sectors have asymmetrical effects on the size of macroeconomic fluctuation:the primary industry(extraction)has little effect;the secondary industry(manufacturing)has a leverage effect mainly caused by heavy industry;the tertiary industry(services)has a clear stabilizing effect,with the effect of transportation,logistics,the postal industry,housing-catering services,and other service industries being most significant,and the effect of wholesale,retail,the finance industry and real estate being less significant due to their own large fluctuations.The policy implications of the findings are that to maintain stable growth in the economy,China should optimize the relations of the three major industrial sectors,and further push for the upgrading of the industrial structure,especially the development of the tertiary industry.
