Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as ...Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.展开更多
Understanding the drivers of variations in fine root lifespan is key to informing nutrient cycling and productivity in terrestrial ecosystems.However,the general patterns and determinants of forest fine root lifespan ...Understanding the drivers of variations in fine root lifespan is key to informing nutrient cycling and productivity in terrestrial ecosystems.However,the general patterns and determinants of forest fine root lifespan at the global scale are still limited.We compiled a dataset of 421 fine root lifespan observations from 76 tree species globally to assess phylogenetic signals among species,explored relationships between fine root lifespan and biotic and abiotic factors,and quantified the relative importance of phylogeny,root system structure and functions,climatic and edaphic factors in driving global fine root lifespan variations.Overall,fine root lifespan showed a clear phylogenetic signal,with gymnosperms having a longer fine root lifespan than angiosperms.Fine root lifespan was longer for evergreens than deciduous trees.Ectomycorrhizal(ECM)plants had an extended fine root lifespan than arbuscular mycorrhizal(AM)plants.Among different climatic zones,fine root lifespan was the longest in the boreal zone,while it did not vary between the temperate and tropical zone.Fine root lifespan increased with soil depth and root order.Furthermore,the analysis of relative importance indicated that phylogeny was the strongest driver influencing the variation in forest fine root lifespan,followed by soil clay content,root order,mean annual temperature,and soil depth,while other environmental factors and root traits exerted weaker effects.Our results suggest that the global pattern of fine root lifespan in forests is shaped by the interplay of phylogeny,root traits and environmental factors.These findings necessitate accurate representations of tree evolutionary history in earth system models to predict fine root longevity and its responses to global changes.展开更多
Alpha-lactalbumin(α-LA)is a major whey protein found in breast milk and plays a crucial role in the growth and development of infants.In this study,Bacillus subtilis RIK1285 harboring AprE signal peptide(SP)was selec...Alpha-lactalbumin(α-LA)is a major whey protein found in breast milk and plays a crucial role in the growth and development of infants.In this study,Bacillus subtilis RIK1285 harboring AprE signal peptide(SP)was selected as the original strain for the production ofα-LA.It was found thatα-LA was identified in the pellet after ultrasonic disruption and centrifugation instead of in the fermentation supernatant.The original strain most likely only producedα-LA intracellular,but not extracellular.To improve the expression and secretion ofα-LA in RIK1285,a library of 173 homologous SPs from the B.subtilis 168 genome was fused with target LALBA gene in the pBE-S vector and expressed extracellularly in RIK1285.SP YjcN was determined to be the best signal peptide.Bands in supernatant were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and purified by nickel column to calculate the highest yield signal peptide.In addition,different promoters(P_(aprE),P_(43),and P_(glv))were compared and applied.The results indicated that the strain RIK1285-pBE-P_(glv)-YjcN-LALBA had the highestα-LA yield,reaching 122.04μg/mL.This study demonstrates successful expression and secretion of humanα-LA in B.subtilis and establishes a foundation for simulating breast milk for infant formulas and developing bioengineered milk.展开更多
文章探讨了气相分子吸收光谱法测定土壤中亚硝酸盐氮时,硫化物、甲醛、VOCs、乙草胺、丙烯酰胺、尿素等土壤中存在的物质对分析可能产生的干扰及干扰去除方法。实验结果表明,硫化物、VOCs对亚硝酸盐氮的测定结果产生正干扰。土壤提取液...文章探讨了气相分子吸收光谱法测定土壤中亚硝酸盐氮时,硫化物、甲醛、VOCs、乙草胺、丙烯酰胺、尿素等土壤中存在的物质对分析可能产生的干扰及干扰去除方法。实验结果表明,硫化物、VOCs对亚硝酸盐氮的测定结果产生正干扰。土壤提取液中加入乙酸锌+乙酸钠混合溶液并将溶液调为弱碱性(p H 10~11),可消除硫化物干扰;土壤提取液加热煮沸3~5 min,可消除VOCs的干扰。甲醛、乙草胺、丙烯酰胺、尿素基本无干扰。展开更多
The solar-blind ultraviolet(UV)wavelength is particularly interesting within the range of 200 nm–300 nm.Here,we propose a focusing metalens,focusing vortex beam(VB)metalens and metalens array that specifically work i...The solar-blind ultraviolet(UV)wavelength is particularly interesting within the range of 200 nm–300 nm.Here,we propose a focusing metalens,focusing vortex beam(VB)metalens and metalens array that specifically work in the UV band to focus a beam or VB.Firstly,a high numerical aperture(NA)focusing metalens working at a wavelength of 214.2 nm was designed,and the NA reached 0.83.The corresponding conversion efficiency of the unit structure reached as high as 94%,and the full width at half maximum was only 117.2 nm.Metalenses with large NA can act as optical tweezers and can be applied to trap ultracold atoms and molecules.Secondly,a focused VB metalens in the wavelength range of200 nm–300 nm was also designed,which can convert polarized light into a VB and focus the VB simultaneously.Finally,a metalens array was developed to focus VBs with different topological charges on the same focal plane.This series of UV metalenses could be widely used in UV microscopy,photolithography,photonics communication,etc.展开更多
How to cultivate and improve graduate students’innovation and practical abilities in software engineering through the curriculum and teaching mode reform is an important issue.In this paper,a research literacy-driven...How to cultivate and improve graduate students’innovation and practical abilities in software engineering through the curriculum and teaching mode reform is an important issue.In this paper,a research literacy-driven teaching mode is proposed.It assists in the reform of the curriculum system.Then,a curriculum system construction framework is proposed,which involves the integration of research literacy into classroom teaching content.It assists in the cultivation of research abilities of graduate students in software engineering.The effectiveness of the curriculum reform is demonstrated through questionnaire surveys and research outcomes of the project team.The results show that the methods explored in this paper can serve as valuable references for future course design and teaching practice in computer-related courses for graduates.展开更多
基金supported by the National Natural Science Foundation of China(52325001,52170009,and 52091542)the National Key Research and Development Program of China(2021YFC3200700)+3 种基金the Program of Shanghai Academic Research Leader,China(21XD1424000)the International Cooperation Project of Shanghai Science and Technology Commission(20230714100)the Key-Area Research and Development Program of Guangdong Province(2020B1111350001)Tongji University Youth 100 Program.
文摘Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.
基金provided by the National Key R&D Program of China(2023YFD2200904)the Scientific Research Project of Anhui Province(2022AH050873)+1 种基金the State Key Laboratory of Subtropical Silviculture(SKLSS-KF2023-08)the Anhui Provincial Science and Technology Special Project(202204c06020014)。
文摘Understanding the drivers of variations in fine root lifespan is key to informing nutrient cycling and productivity in terrestrial ecosystems.However,the general patterns and determinants of forest fine root lifespan at the global scale are still limited.We compiled a dataset of 421 fine root lifespan observations from 76 tree species globally to assess phylogenetic signals among species,explored relationships between fine root lifespan and biotic and abiotic factors,and quantified the relative importance of phylogeny,root system structure and functions,climatic and edaphic factors in driving global fine root lifespan variations.Overall,fine root lifespan showed a clear phylogenetic signal,with gymnosperms having a longer fine root lifespan than angiosperms.Fine root lifespan was longer for evergreens than deciduous trees.Ectomycorrhizal(ECM)plants had an extended fine root lifespan than arbuscular mycorrhizal(AM)plants.Among different climatic zones,fine root lifespan was the longest in the boreal zone,while it did not vary between the temperate and tropical zone.Fine root lifespan increased with soil depth and root order.Furthermore,the analysis of relative importance indicated that phylogeny was the strongest driver influencing the variation in forest fine root lifespan,followed by soil clay content,root order,mean annual temperature,and soil depth,while other environmental factors and root traits exerted weaker effects.Our results suggest that the global pattern of fine root lifespan in forests is shaped by the interplay of phylogeny,root traits and environmental factors.These findings necessitate accurate representations of tree evolutionary history in earth system models to predict fine root longevity and its responses to global changes.
基金This work was funded by National Natural Science Foundation of China(32272279)the Key R&D project of Qingdao Science and Technology Plan(22-3-3-hygg-29-hy).
文摘Alpha-lactalbumin(α-LA)is a major whey protein found in breast milk and plays a crucial role in the growth and development of infants.In this study,Bacillus subtilis RIK1285 harboring AprE signal peptide(SP)was selected as the original strain for the production ofα-LA.It was found thatα-LA was identified in the pellet after ultrasonic disruption and centrifugation instead of in the fermentation supernatant.The original strain most likely only producedα-LA intracellular,but not extracellular.To improve the expression and secretion ofα-LA in RIK1285,a library of 173 homologous SPs from the B.subtilis 168 genome was fused with target LALBA gene in the pBE-S vector and expressed extracellularly in RIK1285.SP YjcN was determined to be the best signal peptide.Bands in supernatant were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and purified by nickel column to calculate the highest yield signal peptide.In addition,different promoters(P_(aprE),P_(43),and P_(glv))were compared and applied.The results indicated that the strain RIK1285-pBE-P_(glv)-YjcN-LALBA had the highestα-LA yield,reaching 122.04μg/mL.This study demonstrates successful expression and secretion of humanα-LA in B.subtilis and establishes a foundation for simulating breast milk for infant formulas and developing bioengineered milk.
文摘文章探讨了气相分子吸收光谱法测定土壤中亚硝酸盐氮时,硫化物、甲醛、VOCs、乙草胺、丙烯酰胺、尿素等土壤中存在的物质对分析可能产生的干扰及干扰去除方法。实验结果表明,硫化物、VOCs对亚硝酸盐氮的测定结果产生正干扰。土壤提取液中加入乙酸锌+乙酸钠混合溶液并将溶液调为弱碱性(p H 10~11),可消除硫化物干扰;土壤提取液加热煮沸3~5 min,可消除VOCs的干扰。甲醛、乙草胺、丙烯酰胺、尿素基本无干扰。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60907003,61805278,61875168,and 22134005)Chongqing Science Funds for Distinguished Young Scientists(Grant No.cstc2021jcyj-jqX0027)+6 种基金Innovation Research 2035 Pilot Plan of Southwest University(Grant No.SWU-XDPY22012)China Postdoctoral Science Foundation(Grant No.2018M633704)Innovation Support Program for Overseas Students in Chongqing(Grant No.cx2021008)Foundation of NUDT(Grant Nos.JC13-02-13 and ZK17-0301)Hunan Provincial Natural Science Foundation of China(Grant No.13JJ3001)Program for New Century Excellent Talents in University(Grant No.NCET-12-0142)Chongqing Talents Program for Outstanding Scientists(Grant No.cstc2021ycjh-bgzxm0178)。
文摘The solar-blind ultraviolet(UV)wavelength is particularly interesting within the range of 200 nm–300 nm.Here,we propose a focusing metalens,focusing vortex beam(VB)metalens and metalens array that specifically work in the UV band to focus a beam or VB.Firstly,a high numerical aperture(NA)focusing metalens working at a wavelength of 214.2 nm was designed,and the NA reached 0.83.The corresponding conversion efficiency of the unit structure reached as high as 94%,and the full width at half maximum was only 117.2 nm.Metalenses with large NA can act as optical tweezers and can be applied to trap ultracold atoms and molecules.Secondly,a focused VB metalens in the wavelength range of200 nm–300 nm was also designed,which can convert polarized light into a VB and focus the VB simultaneously.Finally,a metalens array was developed to focus VBs with different topological charges on the same focal plane.This series of UV metalenses could be widely used in UV microscopy,photolithography,photonics communication,etc.
基金supported by the National Natural Science Foundation of China(62102291)the Ministry ofEducation’s Industry School Cooperation Collaborative Education Project(220606008213849)the Opening Foundation of Engineering Research Center of Hubei Province for Clothing Information(N2022HBCI02)。
文摘How to cultivate and improve graduate students’innovation and practical abilities in software engineering through the curriculum and teaching mode reform is an important issue.In this paper,a research literacy-driven teaching mode is proposed.It assists in the reform of the curriculum system.Then,a curriculum system construction framework is proposed,which involves the integration of research literacy into classroom teaching content.It assists in the cultivation of research abilities of graduate students in software engineering.The effectiveness of the curriculum reform is demonstrated through questionnaire surveys and research outcomes of the project team.The results show that the methods explored in this paper can serve as valuable references for future course design and teaching practice in computer-related courses for graduates.
