Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis o...Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis of the difference remains unclear. These two genotypes had similar total water uptake rates under both WD and well-watered （WW） conditions, and their water uptake rates under WD were significantly decreased compared with those under WW. However, the water uptake rate via the cell-to-cell pathway was significantly increased in Zhenshan 97 but decreased in IRAT109 under WD, whereas the opposite trends were observed through the apoplastic pathway. These results indicated that the stress responses and relative contributions of these two water uptake pathways were associated with rice genotype under WD. The expression levels of OsPIP2;4 and OsPIP2;5 genes were significantly higher in roots of Zhenshan 97 than in IRAT109 under the two conditions. OsPIP2;4 expression in roots was significantly up-regulated under WD, while OsPIP2;5 expression showed no significant change. These results suggest that the expression levels of OsPIP2;4 and OsPIP2;5 in rice are dependent on genotype and water availability. Compared with Zhenshan 97, IRAT109 had a higher root dry weight, water uptake rate and xylem sap flow rate, and lower leaf water potential and root porosity under WD, which might be responsible for the drought resistance in IRAT109.展开更多
Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive r...Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion.展开更多
Iron-based catalysts have been widely used to treat refractory organic pollutants in wastewater.In this paper,magnetic Co-γ-Fe_(2)O_(3)was synthesized by a facile tartaric acid-assisted hydrothermal method,and Co-γ-...Iron-based catalysts have been widely used to treat refractory organic pollutants in wastewater.In this paper,magnetic Co-γ-Fe_(2)O_(3)was synthesized by a facile tartaric acid-assisted hydrothermal method,and Co-γ-Fe_(2)O_(3)/MoS_(2) nanocomposite catalyst was obtained via in situ growth of MoS_(2) nanosheets on Co-γ-Fe_(2)O_(3)nanoparticles.The nanocomposite catalysts were used to decompose bisphenol A(BPA)by activating peroxymonosulfate(PMS).It was shown that only 0.15 g/L catalyst and 0.5 mmol/L PMS degraded 10 mg/L of BPA(99.3%within 10 min)in the pH range of 3–9.PMS was activated due to redox cycling among the pairs Co(III)/Co(II),Fe(III)/Fe(II),and Mo(VI)/Mo(IV).Quenching experiments and electron paramagnetic resonance spectroscopy demonstrated that both radical and non-radical pathways were involved in BPA degradation,in which active radical sulfate radical and non-radical singlet oxygen were the main reactive oxygen species.Ten intermediates were identified by liquid chromatography-coupled mass spectrometry,and three possible BPA degradation pathways were proposed.The toxicity of several degradation intermediates was lower,and Co-γ-Fe_(2)O_(3)/MoS_(2) exhibited excellent reusability and could be magnetically recovered.展开更多
Lesion mmic mutants(LMMs)are plants that spontaneously form lesions without pathogeninfection or external stimulus and exhibit resistance to pathogens.Here,a rice LMM was created by ethylmethane sulfonate mutagenesis,...Lesion mmic mutants(LMMs)are plants that spontaneously form lesions without pathogeninfection or external stimulus and exhibit resistance to pathogens.Here,a rice LMM was created by ethylmethane sulfonate mutagenesis,named as hpil(hydrogen peroxide induced lesion).Diaminobenzidineand trypan blue staining showed that large amounts of H_(2)O_(2) were produced and cell death was occurredat and around the parts of lesion mimic in the rice leaves.The phenotype of hpil is controlled by a singlerecessive gene,localized at a 2 Mb interval on chromosome 2.The data suggested that hpil is a novelLMM with enhanced bacterial and fungal disease resistance,and multiple pathogenesis-related proteins(PRs)were up-regulated.The proteomes of leaves at three positions(different degrees of lesion mimicseverity)were characterized in hpil compared with its wild type plant.Differentially expressed proteinswere detected by two dimensional difference gel electrophoresis and 274 proteins were identified byMALDITOF/TOFTM.These proteins were related to metabolic process,cellular process and response tostimulus,with mostly down-regulated in hpil leaves.Many of these proteins were related to the Calvincycle,photosynthetic electron transport chain,glycolysis/gluconeogenesis and phosphonates pathways.Some resistance-related proteins including 14-3-3 proteins,OsPR10 and antioxidases such asperoxidase,superoxide dismutase and ascorbate peroxidase were up-regulated in leaves with lesionmimic.These results provide the foundation for cloning of the target gene and shed light on themechanism involved in autaimmunity of rice.展开更多
Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,...Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,and advanced oxidation processes.On the other hand,H_(2)O_(2)has also been explored as a liquid fuel alternative to H_(2)or fossil fuels in fuel cells due to its high energy density.However,the current industrial production of H_(2)O_(2)relies on the anthraquinone(AO)method that involves palladium-catalyzed hydrogenation-oxidation steps.展开更多
Fe-N-C materials have received increasing attention,due to its distinctive catalytic activity.However,the Fe-N coordination number dependence of catalytic ability and mechanism for H_(2)O_(2)activation remain elusive....Fe-N-C materials have received increasing attention,due to its distinctive catalytic activity.However,the Fe-N coordination number dependence of catalytic ability and mechanism for H_(2)O_(2)activation remain elusive.Herein,a series of Fe-N-C heterogeneous Fenton-like catalysts with different Fe-N coordination number were prepared for tetracycline degradation.The results demonstrated that samples with Fe-N4 structure exhibited high activity.The excellent performance was mainly ascribed to the high adsorption capacity and the formation of superoxide radicals(•O_(2)^(−))catalyzed by Fe linked to pyridinic nitrogen.The intermediates and degradation pathways of tetracycline degradation by Fe-N-C/H_(2)O_(2)system were analyzed by liquid chromatography coupled to tandem mass spectrometry(LC-MS/MS).Furthermore,we applied our Fe-N-C catalysts to treat simulated pharmaceutical wastewater with high tetracycline degradation capacity despite high concentrations of organic matter such as oxalic acid and various ionic interferences.Our work reveals the dependence of the activation H_(2)O_(2)on the Fe-N coordination environment and the degradation mechanism of these catalysts.It provides insights into the prospects for tuning the catalyst in practical applications.展开更多
Soil remediation containing numerous organic contaminants is of great significance to ecological environment.Herein,the synergetic effects of Ce-Mn/Al_(2)O_(3)with different active components on catalytic thermal deso...Soil remediation containing numerous organic contaminants is of great significance to ecological environment.Herein,the synergetic effects of Ce-Mn/Al_(2)O_(3)with different active components on catalytic thermal desorption of chlorobenzene in soil were investigated.The optimized Ce-Mn/Al_(2)O_(3)drastically enhance the desorption efficiency of chlorobenzene,and the corresponding conversion reaches 100%within 1 h at a low temperature of 120℃.The superior performance is ascribed to the formation of Ce-Mn solid solution during the calcination process,resulting in a certain lattice change to the generation of abundant oxygen vacancies and acidic sites.Combining with the analysis of in-situ diffuse reflectance infrared spectroscopy and gas chromatography-mass spectrometry,the final products of chlorobenzene are decomposed into CO_(2),H_(2)O,Cl_(2)and HCl.This work sheds light on the rational design of highly-active catalysts for practical applications of sustainable soil remediation.展开更多
A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-ch...A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.展开更多
The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive lipos...The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.展开更多
Comprehensive observations of the nocturnal atmospheric oxidation of NO_(3)and N_(2)O_(5)were conducted at a suburban site in Changzhou in the YRD using cavity ring-down spectroscopy(CRDS)from 27 May to 24 June,2019.H...Comprehensive observations of the nocturnal atmospheric oxidation of NO_(3)and N_(2)O_(5)were conducted at a suburban site in Changzhou in the YRD using cavity ring-down spectroscopy(CRDS)from 27 May to 24 June,2019.High concentrations of NO_(3)precursors were observed,and the nocturnal production rate of NO_(3)was determined to be 1.7±1.2 ppbv/hr.However,the nighttime NO_(3)and N_(2)O_(5)concentrations were relatively low,with maximum values of 17.7 and 304.7 pptv,respectively,illustrating the rapid loss ofNO_(3)andN_(2)O_(5).Itwas found that NO_(3)dominated the nighttime atmospheric oxidation,accounting for 50.7%,whileO3 andOH only contributed 34.1%and 15.2%,respectively.For the reactions of NO_(3)with volatile organic compounds(VOCs),styrenewas found to account for 60.3%,highlighting its dominant role in the NO_(3)reactivity.In general,the contributions of the reactions between NO_(3)and VOCs and the N_(2)O_(5)uptake to NO_(3)losswere found to be about 39.5%and 60.5%,respectively,indicating that N_(2)O_(5)uptake also played an important role in the loss of NO_(3)and N_(2)O_(5),especially under the high humidity conditions in China.The formation of nitrate at night mainly originated from N_(2)O_(5)uptake,and the maximum production rate of NO_(3)^(-)reached 6.5 ppbv/hr.The average NOx consumption rate via NO_(3)and N_(2)O_(5)chemistry was found to be 0.4 ppbv/h,accounting for 47.9%of the total NO_(x)removal.The predominant roles of NO_(3)and N_(2)O_(5)in nitrate formation and NO_(x)removal in the YRD region was highlighted in this study.展开更多
基金jointly supported by the National Science&Technology Pillar Program(Grant No.2013BAD07B10)Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110146110021)
文摘Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis of the difference remains unclear. These two genotypes had similar total water uptake rates under both WD and well-watered （WW） conditions, and their water uptake rates under WD were significantly decreased compared with those under WW. However, the water uptake rate via the cell-to-cell pathway was significantly increased in Zhenshan 97 but decreased in IRAT109 under WD, whereas the opposite trends were observed through the apoplastic pathway. These results indicated that the stress responses and relative contributions of these two water uptake pathways were associated with rice genotype under WD. The expression levels of OsPIP2;4 and OsPIP2;5 genes were significantly higher in roots of Zhenshan 97 than in IRAT109 under the two conditions. OsPIP2;4 expression in roots was significantly up-regulated under WD, while OsPIP2;5 expression showed no significant change. These results suggest that the expression levels of OsPIP2;4 and OsPIP2;5 in rice are dependent on genotype and water availability. Compared with Zhenshan 97, IRAT109 had a higher root dry weight, water uptake rate and xylem sap flow rate, and lower leaf water potential and root porosity under WD, which might be responsible for the drought resistance in IRAT109.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government,Ministry of Science and ICT(MSIT)(NRF-2020M3D1A2102837)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(20214000000500,training program of CCUS for the green growth)。
文摘Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion.
基金supported by Natural Science Foundation of Fujian Province(China)(No.2022J0113)Fuzhou University Testing Fund of Precious Apparatus(China)(No.2022T025)。
文摘Iron-based catalysts have been widely used to treat refractory organic pollutants in wastewater.In this paper,magnetic Co-γ-Fe_(2)O_(3)was synthesized by a facile tartaric acid-assisted hydrothermal method,and Co-γ-Fe_(2)O_(3)/MoS_(2) nanocomposite catalyst was obtained via in situ growth of MoS_(2) nanosheets on Co-γ-Fe_(2)O_(3)nanoparticles.The nanocomposite catalysts were used to decompose bisphenol A(BPA)by activating peroxymonosulfate(PMS).It was shown that only 0.15 g/L catalyst and 0.5 mmol/L PMS degraded 10 mg/L of BPA(99.3%within 10 min)in the pH range of 3–9.PMS was activated due to redox cycling among the pairs Co(III)/Co(II),Fe(III)/Fe(II),and Mo(VI)/Mo(IV).Quenching experiments and electron paramagnetic resonance spectroscopy demonstrated that both radical and non-radical pathways were involved in BPA degradation,in which active radical sulfate radical and non-radical singlet oxygen were the main reactive oxygen species.Ten intermediates were identified by liquid chromatography-coupled mass spectrometry,and three possible BPA degradation pathways were proposed.The toxicity of several degradation intermediates was lower,and Co-γ-Fe_(2)O_(3)/MoS_(2) exhibited excellent reusability and could be magnetically recovered.
基金supported by the Zhejiang Provincial Key Research and Development Plan(Grant No.2019C02006)the National Key Research and Development Program of China(Grant Nos.2016YFD0200804 and 2016YFD0100601-15)+2 种基金the Key Program of Zhejiang Provincial Foundation for Natural Science(Grant No.LZ16C130002)the Zhejiang Fundamental Public Welfare Research Program(Grant No.LGN19C140008)the State Key Laboratory for Managing Biotic and Chemical Threats to Quality and Safety of Agro-products(Grant No.2010DS700124-ZZ1907).
文摘Lesion mmic mutants(LMMs)are plants that spontaneously form lesions without pathogeninfection or external stimulus and exhibit resistance to pathogens.Here,a rice LMM was created by ethylmethane sulfonate mutagenesis,named as hpil(hydrogen peroxide induced lesion).Diaminobenzidineand trypan blue staining showed that large amounts of H_(2)O_(2) were produced and cell death was occurredat and around the parts of lesion mimic in the rice leaves.The phenotype of hpil is controlled by a singlerecessive gene,localized at a 2 Mb interval on chromosome 2.The data suggested that hpil is a novelLMM with enhanced bacterial and fungal disease resistance,and multiple pathogenesis-related proteins(PRs)were up-regulated.The proteomes of leaves at three positions(different degrees of lesion mimicseverity)were characterized in hpil compared with its wild type plant.Differentially expressed proteinswere detected by two dimensional difference gel electrophoresis and 274 proteins were identified byMALDITOF/TOFTM.These proteins were related to metabolic process,cellular process and response tostimulus,with mostly down-regulated in hpil leaves.Many of these proteins were related to the Calvincycle,photosynthetic electron transport chain,glycolysis/gluconeogenesis and phosphonates pathways.Some resistance-related proteins including 14-3-3 proteins,OsPR10 and antioxidases such asperoxidase,superoxide dismutase and ascorbate peroxidase were up-regulated in leaves with lesionmimic.These results provide the foundation for cloning of the target gene and shed light on themechanism involved in autaimmunity of rice.
文摘Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,and advanced oxidation processes.On the other hand,H_(2)O_(2)has also been explored as a liquid fuel alternative to H_(2)or fossil fuels in fuel cells due to its high energy density.However,the current industrial production of H_(2)O_(2)relies on the anthraquinone(AO)method that involves palladium-catalyzed hydrogenation-oxidation steps.
基金supported by the National Key Research and Development Program of China(No.2019YFC1906401-03)the Harbin Institute of Technology National Engineering Research Center of Urban Water Resources Co.,Ltd.(No.GJS-YFLX202207280002)。
文摘Fe-N-C materials have received increasing attention,due to its distinctive catalytic activity.However,the Fe-N coordination number dependence of catalytic ability and mechanism for H_(2)O_(2)activation remain elusive.Herein,a series of Fe-N-C heterogeneous Fenton-like catalysts with different Fe-N coordination number were prepared for tetracycline degradation.The results demonstrated that samples with Fe-N4 structure exhibited high activity.The excellent performance was mainly ascribed to the high adsorption capacity and the formation of superoxide radicals(•O_(2)^(−))catalyzed by Fe linked to pyridinic nitrogen.The intermediates and degradation pathways of tetracycline degradation by Fe-N-C/H_(2)O_(2)system were analyzed by liquid chromatography coupled to tandem mass spectrometry(LC-MS/MS).Furthermore,we applied our Fe-N-C catalysts to treat simulated pharmaceutical wastewater with high tetracycline degradation capacity despite high concentrations of organic matter such as oxalic acid and various ionic interferences.Our work reveals the dependence of the activation H_(2)O_(2)on the Fe-N coordination environment and the degradation mechanism of these catalysts.It provides insights into the prospects for tuning the catalyst in practical applications.
基金Project supported by the National Key Research and Development Program of China(2021YFB3500600,2021YFB3500605,2022YFB3504100)Key R&D Program of Jiangsu Province(BE2022142)+2 种基金Natural Science Foundation of Jiangsu Province(BK20220365)Jiangsu International Cooperation Project(BZ2021018)Chunhui Project Foundation of the Education Department of China(202200554)。
文摘Soil remediation containing numerous organic contaminants is of great significance to ecological environment.Herein,the synergetic effects of Ce-Mn/Al_(2)O_(3)with different active components on catalytic thermal desorption of chlorobenzene in soil were investigated.The optimized Ce-Mn/Al_(2)O_(3)drastically enhance the desorption efficiency of chlorobenzene,and the corresponding conversion reaches 100%within 1 h at a low temperature of 120℃.The superior performance is ascribed to the formation of Ce-Mn solid solution during the calcination process,resulting in a certain lattice change to the generation of abundant oxygen vacancies and acidic sites.Combining with the analysis of in-situ diffuse reflectance infrared spectroscopy and gas chromatography-mass spectrometry,the final products of chlorobenzene are decomposed into CO_(2),H_(2)O,Cl_(2)and HCl.This work sheds light on the rational design of highly-active catalysts for practical applications of sustainable soil remediation.
基金This work was supported by the National Natural Science Foundation of China(51972030,52102207)Beijing Natural Science Foundation(Z220021)+2 种基金the National Key R&D Program of China(2021YFB3800300)the Joint Funds of the National Natural Science Foundation of China(U2130204)Beijing Outstanding Young Sci-entists Program(BJJWZYJH01201910007023).
文摘A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.
基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120001110012)the National Basic Research Program of China(973 Program,Grant No.2013CB932501)National Natural Science Foundation of China(Grant No.81172992)
文摘The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.
基金supported by the National Natural Science Foundation of China(Nos.42030609,91644107,61905003,and U19A2044)the Natural Science Foundation of Anhui Province(No.2008085J20)+1 种基金the National Key Research and Development Program of China(No.2017YFC0209403)the Cultivating Project of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDPB1901)
文摘Comprehensive observations of the nocturnal atmospheric oxidation of NO_(3)and N_(2)O_(5)were conducted at a suburban site in Changzhou in the YRD using cavity ring-down spectroscopy(CRDS)from 27 May to 24 June,2019.High concentrations of NO_(3)precursors were observed,and the nocturnal production rate of NO_(3)was determined to be 1.7±1.2 ppbv/hr.However,the nighttime NO_(3)and N_(2)O_(5)concentrations were relatively low,with maximum values of 17.7 and 304.7 pptv,respectively,illustrating the rapid loss ofNO_(3)andN_(2)O_(5).Itwas found that NO_(3)dominated the nighttime atmospheric oxidation,accounting for 50.7%,whileO3 andOH only contributed 34.1%and 15.2%,respectively.For the reactions of NO_(3)with volatile organic compounds(VOCs),styrenewas found to account for 60.3%,highlighting its dominant role in the NO_(3)reactivity.In general,the contributions of the reactions between NO_(3)and VOCs and the N_(2)O_(5)uptake to NO_(3)losswere found to be about 39.5%and 60.5%,respectively,indicating that N_(2)O_(5)uptake also played an important role in the loss of NO_(3)and N_(2)O_(5),especially under the high humidity conditions in China.The formation of nitrate at night mainly originated from N_(2)O_(5)uptake,and the maximum production rate of NO_(3)^(-)reached 6.5 ppbv/hr.The average NOx consumption rate via NO_(3)and N_(2)O_(5)chemistry was found to be 0.4 ppbv/h,accounting for 47.9%of the total NO_(x)removal.The predominant roles of NO_(3)and N_(2)O_(5)in nitrate formation and NO_(x)removal in the YRD region was highlighted in this study.
