Benefiting from its favorable effects in promoting intestinal peristalsis,increasing satiety and reducing postprandial blood sugar,wheat bran insoluble dietary fiber(IDF)could be added to noodles to improve the nutrit...Benefiting from its favorable effects in promoting intestinal peristalsis,increasing satiety and reducing postprandial blood sugar,wheat bran insoluble dietary fiber(IDF)could be added to noodles to improve the nutrition value of noodle products.However,the addition of IDF usually results in an adverse effect on the quality characteristics of fiber fortified products,leading to unfavorable texture and consumption drop.It was found that IDF could weaken dough characteristics,thereby causing the quality deterioration of noodles,but the mechanism is unclear as yet.This study aimed to investigate the effects of different amounts of IDF on the texture quality and cooking quality of noodles.The water distribution,rheological properties,pasting properties and cooking properties of the noodles were determined by low-field nuclear magnetic resonance(LF-NMR),dynamic rheometer,and rapid visco-analyzer.The results of the LF-NMR showed that the increased IDF in the noodles resulted in a contraction of relaxation time and an increase in the proportion of loosely bound water.At a high amount of IDF,the water absorption and tensile distance of the noodles significantly decreased and the cooking loss rate increased,with a downward trend in peak viscosity,final viscosity and setback values.Moreover,IDF could improve the storage modulus and loss modulus of sheeted dough and enhance the texture of noodles.Furthermore,the correlations between IDF addition amounts and rheological properties as well as cooking properties were analyzed,and the results confirmed that noodles with the IDF amount of 2%–4%had higher nutrition and quality.This study provides the basis for future development and improvement of IDF-enriched health foods.展开更多
Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved i...Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved in electrocatalytic systems. This electrodepreparation consists of a two-step procedure: first electropolymerization of aniline onto carbonfiber and then electrodeposition of platinum. The catalytic activity of theplatinum-polyanihne-modified carbon fiber electrode (Pt/PAni/C) was compared with that of a barecarbon fiber electrode (Pt/C) by the oxidation of methanol. The maximum oxidation current ofmethanol on Pt/PAni/C is 50.7 mA centre dot cm^(-2), which is 6.7 times higher than 7.6 mA centredot cm^(-2) on the Pt/C. Scanning electron microscopy was used to investigate the dispersion of theplatinum particles of about 0.4 um.展开更多
Genomic variants libraries are conducive to obtain dominant strains with desirable phenotypic traits.The non-homologous end joining(NHEJ),which enables foreign DNA fragments to be randomly integrated into different ch...Genomic variants libraries are conducive to obtain dominant strains with desirable phenotypic traits.The non-homologous end joining(NHEJ),which enables foreign DNA fragments to be randomly integrated into different chromosomal sites,shows prominent capability in genomic libraries construction.In this study,we established an efficient NHEJ-mediated genomic library technology in Yarrowia lipolytica through regulation of NHEJ repair process,employment of defective Ura marker and optimization of iterative transformations,which enhanced genes integration efficiency by 4.67,22.74 and 1.87 times,respectively.We further applied this technology to create high lycopene producing strains by multi-integration of heterologous genes of CrtE,CrtB and CrtI,with 23.8 times higher production than rDNA integration through homologous recombination(HR).The NHEJ-mediated genomic library technology also achieved random and scattered integration of loxP and vox sites,with the copy number up to 65 and 53,respectively,creating potential for further application of recombinase mediated genome rearrangement in Y.lipolytica.This work provides a high-efficient NHEJ-mediated genomic library technology,which enables random and scattered genomic integration of multiple heterologous fragments and rapid generation of diverse strains with superior phenotypes within 96 h.This novel technology also lays an excellent foundation for the development of other genetic technologies in Y.lipolytica.展开更多
The estimation of above-ground biomass(AGB) and carbon storage is very important for arid and semi-arid ecosystems.HJ-1A/B satellite data combined with field measurement data was used for the estimation of shrub AGB a...The estimation of above-ground biomass(AGB) and carbon storage is very important for arid and semi-arid ecosystems.HJ-1A/B satellite data combined with field measurement data was used for the estimation of shrub AGB and carbon storage in the Mu Us desert,China.The correlations of shrub AGB and spectral reflectance of four bands as well as their combined vegetation indexes were respectively analyzed and stepwise regression analysis was employed to establish AGB prediction equation.The prediction equation based on ratio vegetation index(RVI)was proved to be more suitable for shrub AGB estimation in the Mu Us desert than others.Shrub AGB and carbon storage were mapped using the RVI based prediction model in final.The statistics showed the western Mu Us desert has relatively high AGB and carbon storage,and that the gross shrub carton storage in Mu Us desert reaches 16 799 200 t,which has greatly contributed to the carbon fixation in northern China.展开更多
Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant growth.Here,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forest...Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant growth.Here,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forests,to simulate carbon limitation through artificial 25%,50%,and 75%defoliation treatments and explore the effects on root,stem,and leaf morphology,biomass accumulation,and carbon allocation strategies.At the 60th d after treat-ment,under 25%defoliation treatment,the plant height,specific leaf weight,root surface area and volume,and concentrations of non-structural carbohydrates in stem and root were significantly increased by 9.13%,20.00%,16.60%,31.95%,5.12%,and 9.34%,respectively,relative to the control.There was no significant change in the growth indicators under 50%defoliation treatment,but the concentrations of non-structural carbohydrates in the leaf and stem significantly decreased,showing mostly a negative correlation between them.The opposite was observed in the root.Under 75%defoliation treatment,the plant height,ground diameter,leaf number,single leaf area,root,stem,and total biomass were significantly reduced by 14.15%,10.24%,14.86%,11.31%,11.56%,21.87%,and 16.82%,respectively,relative to the control.The concentrations of non-structural carbohydrates in various organs were significantly reduced,particularly in the consumption of the starch concentrations in the stem and root.These results indicated that carbon allocation strategies can be adjusted to increase the con-centration of non-structural carbohydrates in root and meet plant growth needs under 25%and 50%defoliation.However,75%defoliation significantly limited the distribution of non-structural carbohydrates to roots and stems,reduced carbon storage,and thus inhibited plant growth.Defoliation-induced carbon limitation altered the carbon allocation pattern of P.talassica×P.euphratica,and the relationship between carbon reserves in roots and tree growth recovery after defoliation was greater.This study provides a theoretical bas展开更多
Exploring plant behavior at the cellular scale in a minimally invasive manner is critical to understanding plant adaptation to the environment.Phytohormones play vital regulatory roles in multiple aspects of plant gro...Exploring plant behavior at the cellular scale in a minimally invasive manner is critical to understanding plant adaptation to the environment.Phytohormones play vital regulatory roles in multiple aspects of plant growth and development and acclimation to environmental changes.Since the biosynthesis,modification,transportation,and degradation of plant hormones in plants change with time and space,their content level and distribution are highly dynamic.To monitor the production,transport,perception,and distribution of phytohormones within undamaged tissues,we require qualitative and quantitative tools endowed with remarkably high temporal and spatial resolution.Fluorescent probes are regarded as excellent tools for widespread plant imaging because of their high sensitivity and selectivity,reproducibility,real-time in situ detection,and uncomplicated mechanism elucidation.In this review,we provide a systematical overview of the progress in the sensing and imaging of phytohormone fluorescent probes and fluorescently labeled phytohormones to their receptors in plants.Moreover,forthcoming viewpoints and possible applications of these fluorescent probes within the realm of plants are also presented.We hold the conviction that the new perspective brought by this paper can promote the development of fluorescent probes,enabling them to have better detection performance in plant hormone imaging.展开更多
Dear Editor,Since the outbreak of COVID-19 at the end of 2019,its causative agent SARS-Co V-2 has been spreading around the world for one and half a year.During the long global circulation of SARS-Co V-2,mutations in ...Dear Editor,Since the outbreak of COVID-19 at the end of 2019,its causative agent SARS-Co V-2 has been spreading around the world for one and half a year.During the long global circulation of SARS-Co V-2,mutations in the viral genome gradually emerged and accumulated。展开更多
Background Rhizosphere fungi play an important role in plant community dynamics and biogeochemical cycling.While the drivers of fungal community assembly have been studied in varied ecosystems,it is still unclear how ...Background Rhizosphere fungi play an important role in plant community dynamics and biogeochemical cycling.While the drivers of fungal community assembly have been studied in varied ecosystems,it is still unclear how these processes function for rhizosphere soil fungi in temperate forests.Furthermore,it is unknown whether the relative contributions of important determinants remain consistent or vary across fungal ecological guilds.This study used high-throughput next-generation sequencing to characterize the fungal communities of 247 rhizosphere soil samples from 19 tree species in a temperate forest within Northeast China.We aimed to investigate how three important determinants in temperate forests(host tree species,neighbouring plant communities,and edaphic properties)influence the community assembly of fungal functional guilds in the rhizosphere soil of trees.Results We found that host tree species contributed more to plant pathogens’community composition than ectomycorrhizal fungi,and plant pathogens consistently showed higher host specialization than ectomycorrhizal fungi.Saprotrophs also showed high host specialization,which was mediated by the tree species’effect on rhizosphere soil pH.Although neighboring plant communities contributed remarkably to richness of all fungal guilds,this effect on fungal composition varied across functional guilds,with stronger effect for biotrophic guilds(plant pathogens and ectomycorrhizal fungi)than for non-biotrophic guild(saprotrophs).Neighboring plant communities shaped the ectomycorrhizal community composition strongly in all samples regardless of host trees’mycorrhizal type,whereas edaphic properties were the most important drivers for this guild in samples from only ectomycorrhizal-associated trees.Edaphic properties played an important role in shaping ectomycorrhizal and saprotrophic fungal compositions,indicating the importance of edaphic properties on the fungal functional guilds associated with the absorption and decomposition of nutrients.Conclusions These 展开更多
In order to overcome the shortcomings of the traditional sling suspension method,such as complex structure of suspension truss,large running resistance,and low precision of position servo system,a gravity compensation...In order to overcome the shortcomings of the traditional sling suspension method,such as complex structure of suspension truss,large running resistance,and low precision of position servo system,a gravity compensation method of lunar rover based on the combination of active suspension and active position following of magnetic levitation is proposed,and the overall design is carried out.The dynamic model of the suspension module of microgravity compensation system was established,and the decoupling control between the constant force component and the position servo component was analyzed and verified.The constant tension control was achieved by using hybrid force/position control.The position following control was realized by using fuzzy adaptive PID(proportional⁃integral⁃differential)control.The stable suspension control was realized based on the principle of force balance.The simulation results show that the compensation accuracy of constant tension could reach more than 95%,the position deviation was less than 5 mm,the position deviation angle was less than 0.025°,and the air gap recovered stability within 0.1 s.The gravity compensation system has excellent dynamic performance and can meet the requirements of microgravity simulation experiment of lunar rover.展开更多
Purpose In order to increase CSNS beam power from 100 to 500 kW,the linac injection energy needs to be increased from 80 to 300 MeV.The combined layout of superconducting spoke cavities and lliptical cavities will be ...Purpose In order to increase CSNS beam power from 100 to 500 kW,the linac injection energy needs to be increased from 80 to 300 MeV.The combined layout of superconducting spoke cavities and lliptical cavities will be adopted to accelerate H-beam to 300 MeV.In this paper,a compact single spoke cavity withφ50-mm beam aperture was proposed,with the RF performance of the spoke cavity optimized to E_(p)/E_(acc).<5,E_(p)/E_(acc)<9,as well as the good multipacting behavior.Methods CST Microwave Studio was used to optimize the RF performance(E_(peak)/E_(acc),B_(peak)/E_(acc) R/Q)with cavity geometry parameters.After electromagnetic design was finished,multipacting behavior was studied with CST Particle Studio module,and cavity shape modification was made to get a reasonable<SEY>value.Results The simulation got optimum results of E_(peak)/E_(acc)=4.97 and B_(peak)/E_((acc)=8.42 mT/(MV/m),and the<SEY>max is 1.52at E_(acc)=7.74 MV/m.Conclusion A 648 MHzβ=0.4 single spoke cavity with beam apertureФ50 mm was proposed in the paper.This compact cavity may be a very promising option for CSNS linac upgrading.In addition to the optimization of the RF parameters,the multipacting behavior of the cavity is also studied,and cavity shape is optimized to reduce<SEY>value.展开更多
Background A lowβsuperconducting elliptical cavity was designed for the China Spallation Neutron Source phase II project(CSNS-II).Methods The method to improve the mechanical stability of the lowβsuperconducting ell...Background A lowβsuperconducting elliptical cavity was designed for the China Spallation Neutron Source phase II project(CSNS-II).Methods The method to improve the mechanical stability of the lowβsuperconducting elliptical cavity was introduced,and the corresponding mechanical design was given.The software COMSOL Multiphysics and ANSYS APDL were used to calculate the static Lorentz force detuning factor k_(L)(LFD)and the helium pressure sensitivity factor k_(p)(DFDP)of the bare cavity,which were−4.71 Hz(MV/m)^(−2) and−21.1 Hz/mbar,respectively.The double-ring stiffeners reinforcement scheme was adopted.Results The radii of the double-ring stiffeners were 70 and 135 mm,respectively.The structure design of the helium vessel of the cavity was given.The following is the mechanical parameters of the reinforced cavity,the tuning sensitivity is 199.8 kHz/mm,longitudinal stiffness is 4.76kN/mm,k_(L) and k_(p) were−1.39 Hz(MV/m)^(−2) and 4.67 Hz/mbar,respectively,which met the operating requirements.The tuning sensitivity and stiffness of the reinforced cavity with different wall thicknesses were optimized,and the final wall thickness was selected as 4 mm.Conclusion The mechanical design of CSNS-II 648 MHz five-cell lowβsuperconducting elliptical cavity was introduced systematically in the paper.The LFD,DFDP,and the maximum surface stress of the cavity were reduced by optimizing the cavity wall thickness and the position of the double-ring stiffeners.The reinforced cavity met operational requirements.展开更多
Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a...Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a good pre-research cavity for CSNS to learn SRF technology.In this paper,the sequential approach of analysis and optimization performed for the structural design of 648 MHz SSR prototype are presented.Methods The COMSOL Multiphysics is used to perform the multiphysics analysis of jacketed cavity.Firstly,the mechanical performance of bare cavity is estimated,and then,several stiffeners are added to strengthen the cavity.After that,the Lorentz coefficient and helium fluctuation df/dp of jacketed cavity are optimized.At last,the tuning sensitivity and mechanical performance of maximum allowable working pressure are calculated.Results The final results of Lorentz coefficient and df/dp are-5.06 Hz/(MV/m)^(2)and 0.3 Hz/mbar,respectively,and the tuning range of jacketed cavity is larger than±1000 kHz at 2 K.Conclusion The structural design of a 648 MHz SSR prototype is performed in this paper.The Lorentz coefficient and df/dp are carefully optimized.The simulation result shows all mechanical performance satisfies the design goals very well.展开更多
Lactoferrin is a member of the transferrin family of multifunctional iron binding glycoproteins.While numerous physiological functions have been described for lactoferrin,the mechanisms underlying these functions are ...Lactoferrin is a member of the transferrin family of multifunctional iron binding glycoproteins.While numerous physiological functions have been described for lactoferrin,the mechanisms underlying these functions are not clear.To further study the functions and mechanisms of lactoferrin,we modified the lactoferrin promoter of mice using the CRISPR/Cas9 system to reduce or eliminate lactoferrin expression.Seven mice with lactoferrin promoter mutations were obtained with an efficiency of 24%(7/29)by injecting the plasmid pX330,expressing a small guide RNA and human codonoptimized SpCas9,into fertilized eggs of mice.Plasmid integration and off-targeting of pX330 were not detected.These results confirmed that pronuclear injection of a circular plasmid is a feasible and efficient method for targeted mutagenesis in mice.展开更多
The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kern...The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kernel or generator, which describes eflhcts of the bath degrees of freedom. Since the exact TCL generators are usually hard to calculate analytically, most applications of the TCL generalized master equation have relied on approximate generators using second and fourth order perturbative expansions. By using the hierarchical equation of motion （HEOM） and extended HEOM methods, we present a new approach to calculating the exact TCL generator and its high order perturbative expansions. The new approach is applied to the spin-boson model with diflhrent sets of parameters, to investigate the convergence of the high order expansiolls of the TCL generator. We also discuss circumstances where the exact TCL generator becomes singular for the spin-boson model, and a model of excitation energy transfer in the Fenna-Matthews-Olson complex.展开更多
基金supported by Zhongyuan Scholars in Henan Province(No.192101510004)the Natural Science Foundation of China(No.31671810)+2 种基金Project of Green Manufacturing 2025.China(Ministry of industry and information Technology.2018-272)Strategic Consulting Research Project of Henan Institute of Chinese Engineering Development Strategies(No.2020HENZT13)the Key scientific and technological project of Henan Province(No.202102110143).
文摘Benefiting from its favorable effects in promoting intestinal peristalsis,increasing satiety and reducing postprandial blood sugar,wheat bran insoluble dietary fiber(IDF)could be added to noodles to improve the nutrition value of noodle products.However,the addition of IDF usually results in an adverse effect on the quality characteristics of fiber fortified products,leading to unfavorable texture and consumption drop.It was found that IDF could weaken dough characteristics,thereby causing the quality deterioration of noodles,but the mechanism is unclear as yet.This study aimed to investigate the effects of different amounts of IDF on the texture quality and cooking quality of noodles.The water distribution,rheological properties,pasting properties and cooking properties of the noodles were determined by low-field nuclear magnetic resonance(LF-NMR),dynamic rheometer,and rapid visco-analyzer.The results of the LF-NMR showed that the increased IDF in the noodles resulted in a contraction of relaxation time and an increase in the proportion of loosely bound water.At a high amount of IDF,the water absorption and tensile distance of the noodles significantly decreased and the cooking loss rate increased,with a downward trend in peak viscosity,final viscosity and setback values.Moreover,IDF could improve the storage modulus and loss modulus of sheeted dough and enhance the texture of noodles.Furthermore,the correlations between IDF addition amounts and rheological properties as well as cooking properties were analyzed,and the results confirmed that noodles with the IDF amount of 2%–4%had higher nutrition and quality.This study provides the basis for future development and improvement of IDF-enriched health foods.
文摘Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved in electrocatalytic systems. This electrodepreparation consists of a two-step procedure: first electropolymerization of aniline onto carbonfiber and then electrodeposition of platinum. The catalytic activity of theplatinum-polyanihne-modified carbon fiber electrode (Pt/PAni/C) was compared with that of a barecarbon fiber electrode (Pt/C) by the oxidation of methanol. The maximum oxidation current ofmethanol on Pt/PAni/C is 50.7 mA centre dot cm^(-2), which is 6.7 times higher than 7.6 mA centredot cm^(-2) on the Pt/C. Scanning electron microscopy was used to investigate the dispersion of theplatinum particles of about 0.4 um.
基金supported by Major Program of the National Natural Science Foundation of China(21621004)the Natural Science Foundation of Tianjin City(19JCQNJC09200)the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2018-16).
文摘Genomic variants libraries are conducive to obtain dominant strains with desirable phenotypic traits.The non-homologous end joining(NHEJ),which enables foreign DNA fragments to be randomly integrated into different chromosomal sites,shows prominent capability in genomic libraries construction.In this study,we established an efficient NHEJ-mediated genomic library technology in Yarrowia lipolytica through regulation of NHEJ repair process,employment of defective Ura marker and optimization of iterative transformations,which enhanced genes integration efficiency by 4.67,22.74 and 1.87 times,respectively.We further applied this technology to create high lycopene producing strains by multi-integration of heterologous genes of CrtE,CrtB and CrtI,with 23.8 times higher production than rDNA integration through homologous recombination(HR).The NHEJ-mediated genomic library technology also achieved random and scattered integration of loxP and vox sites,with the copy number up to 65 and 53,respectively,creating potential for further application of recombinase mediated genome rearrangement in Y.lipolytica.This work provides a high-efficient NHEJ-mediated genomic library technology,which enables random and scattered genomic integration of multiple heterologous fragments and rapid generation of diverse strains with superior phenotypes within 96 h.This novel technology also lays an excellent foundation for the development of other genetic technologies in Y.lipolytica.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2007CB714404)the National Natural Science Foundation of China(Grant No.40871173)the Special Grantfor Prevention and Treatment of Infectious Diseases(2008ZX10004-012)
文摘The estimation of above-ground biomass(AGB) and carbon storage is very important for arid and semi-arid ecosystems.HJ-1A/B satellite data combined with field measurement data was used for the estimation of shrub AGB and carbon storage in the Mu Us desert,China.The correlations of shrub AGB and spectral reflectance of four bands as well as their combined vegetation indexes were respectively analyzed and stepwise regression analysis was employed to establish AGB prediction equation.The prediction equation based on ratio vegetation index(RVI)was proved to be more suitable for shrub AGB estimation in the Mu Us desert than others.Shrub AGB and carbon storage were mapped using the RVI based prediction model in final.The statistics showed the western Mu Us desert has relatively high AGB and carbon storage,and that the gross shrub carton storage in Mu Us desert reaches 16 799 200 t,which has greatly contributed to the carbon fixation in northern China.
基金funded by the Talents ans its Youth Project of Xinjiang Production and Construction Corps(38000020924,380000358).
文摘Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant growth.Here,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forests,to simulate carbon limitation through artificial 25%,50%,and 75%defoliation treatments and explore the effects on root,stem,and leaf morphology,biomass accumulation,and carbon allocation strategies.At the 60th d after treat-ment,under 25%defoliation treatment,the plant height,specific leaf weight,root surface area and volume,and concentrations of non-structural carbohydrates in stem and root were significantly increased by 9.13%,20.00%,16.60%,31.95%,5.12%,and 9.34%,respectively,relative to the control.There was no significant change in the growth indicators under 50%defoliation treatment,but the concentrations of non-structural carbohydrates in the leaf and stem significantly decreased,showing mostly a negative correlation between them.The opposite was observed in the root.Under 75%defoliation treatment,the plant height,ground diameter,leaf number,single leaf area,root,stem,and total biomass were significantly reduced by 14.15%,10.24%,14.86%,11.31%,11.56%,21.87%,and 16.82%,respectively,relative to the control.The concentrations of non-structural carbohydrates in various organs were significantly reduced,particularly in the consumption of the starch concentrations in the stem and root.These results indicated that carbon allocation strategies can be adjusted to increase the con-centration of non-structural carbohydrates in root and meet plant growth needs under 25%and 50%defoliation.However,75%defoliation significantly limited the distribution of non-structural carbohydrates to roots and stems,reduced carbon storage,and thus inhibited plant growth.Defoliation-induced carbon limitation altered the carbon allocation pattern of P.talassica×P.euphratica,and the relationship between carbon reserves in roots and tree growth recovery after defoliation was greater.This study provides a theoretical bas
基金supported by the National Key Research and Development Program of China(2022YFD1700300,2022YFE0199800)the National Natural Science Foundation of China(32072443,82104065,32061143045)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20201323)the Distinguished Young Research Project of Anhui Higher Education Institution(2022AH020035).
文摘Exploring plant behavior at the cellular scale in a minimally invasive manner is critical to understanding plant adaptation to the environment.Phytohormones play vital regulatory roles in multiple aspects of plant growth and development and acclimation to environmental changes.Since the biosynthesis,modification,transportation,and degradation of plant hormones in plants change with time and space,their content level and distribution are highly dynamic.To monitor the production,transport,perception,and distribution of phytohormones within undamaged tissues,we require qualitative and quantitative tools endowed with remarkably high temporal and spatial resolution.Fluorescent probes are regarded as excellent tools for widespread plant imaging because of their high sensitivity and selectivity,reproducibility,real-time in situ detection,and uncomplicated mechanism elucidation.In this review,we provide a systematical overview of the progress in the sensing and imaging of phytohormone fluorescent probes and fluorescently labeled phytohormones to their receptors in plants.Moreover,forthcoming viewpoints and possible applications of these fluorescent probes within the realm of plants are also presented.We hold the conviction that the new perspective brought by this paper can promote the development of fluorescent probes,enabling them to have better detection performance in plant hormone imaging.
基金supported by the National Key Research and Development Project of China(2020YFC0842200,2020YFA0707801,and 2021YFC0863300)the National Natural Science Foundation of China(No.82041044)+2 种基金supported by the National Science Fund for Distinguished Young Scholars(81925025)the Innovative Research Group(81621005)from the NSFCthe Innovation Fund for Medical Sciences(2019-I2M-5-049)from the Chinese Academy of Medical Sciences。
文摘Dear Editor,Since the outbreak of COVID-19 at the end of 2019,its causative agent SARS-Co V-2 has been spreading around the world for one and half a year.During the long global circulation of SARS-Co V-2,mutations in the viral genome gradually emerged and accumulated。
基金supported by the National Key Research and Development Program of China(2022YFF1300501)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant XDB31030000)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant ZDBS-LY-DQC019).
文摘Background Rhizosphere fungi play an important role in plant community dynamics and biogeochemical cycling.While the drivers of fungal community assembly have been studied in varied ecosystems,it is still unclear how these processes function for rhizosphere soil fungi in temperate forests.Furthermore,it is unknown whether the relative contributions of important determinants remain consistent or vary across fungal ecological guilds.This study used high-throughput next-generation sequencing to characterize the fungal communities of 247 rhizosphere soil samples from 19 tree species in a temperate forest within Northeast China.We aimed to investigate how three important determinants in temperate forests(host tree species,neighbouring plant communities,and edaphic properties)influence the community assembly of fungal functional guilds in the rhizosphere soil of trees.Results We found that host tree species contributed more to plant pathogens’community composition than ectomycorrhizal fungi,and plant pathogens consistently showed higher host specialization than ectomycorrhizal fungi.Saprotrophs also showed high host specialization,which was mediated by the tree species’effect on rhizosphere soil pH.Although neighboring plant communities contributed remarkably to richness of all fungal guilds,this effect on fungal composition varied across functional guilds,with stronger effect for biotrophic guilds(plant pathogens and ectomycorrhizal fungi)than for non-biotrophic guild(saprotrophs).Neighboring plant communities shaped the ectomycorrhizal community composition strongly in all samples regardless of host trees’mycorrhizal type,whereas edaphic properties were the most important drivers for this guild in samples from only ectomycorrhizal-associated trees.Edaphic properties played an important role in shaping ectomycorrhizal and saprotrophic fungal compositions,indicating the importance of edaphic properties on the fungal functional guilds associated with the absorption and decomposition of nutrients.Conclusions These
基金the National Natural Science Foundation of China(Grant Nos.51305384 and 52075466)。
文摘In order to overcome the shortcomings of the traditional sling suspension method,such as complex structure of suspension truss,large running resistance,and low precision of position servo system,a gravity compensation method of lunar rover based on the combination of active suspension and active position following of magnetic levitation is proposed,and the overall design is carried out.The dynamic model of the suspension module of microgravity compensation system was established,and the decoupling control between the constant force component and the position servo component was analyzed and verified.The constant tension control was achieved by using hybrid force/position control.The position following control was realized by using fuzzy adaptive PID(proportional⁃integral⁃differential)control.The stable suspension control was realized based on the principle of force balance.The simulation results show that the compensation accuracy of constant tension could reach more than 95%,the position deviation was less than 5 mm,the position deviation angle was less than 0.025°,and the air gap recovered stability within 0.1 s.The gravity compensation system has excellent dynamic performance and can meet the requirements of microgravity simulation experiment of lunar rover.
文摘Purpose In order to increase CSNS beam power from 100 to 500 kW,the linac injection energy needs to be increased from 80 to 300 MeV.The combined layout of superconducting spoke cavities and lliptical cavities will be adopted to accelerate H-beam to 300 MeV.In this paper,a compact single spoke cavity withφ50-mm beam aperture was proposed,with the RF performance of the spoke cavity optimized to E_(p)/E_(acc).<5,E_(p)/E_(acc)<9,as well as the good multipacting behavior.Methods CST Microwave Studio was used to optimize the RF performance(E_(peak)/E_(acc),B_(peak)/E_(acc) R/Q)with cavity geometry parameters.After electromagnetic design was finished,multipacting behavior was studied with CST Particle Studio module,and cavity shape modification was made to get a reasonable<SEY>value.Results The simulation got optimum results of E_(peak)/E_(acc)=4.97 and B_(peak)/E_((acc)=8.42 mT/(MV/m),and the<SEY>max is 1.52at E_(acc)=7.74 MV/m.Conclusion A 648 MHzβ=0.4 single spoke cavity with beam apertureФ50 mm was proposed in the paper.This compact cavity may be a very promising option for CSNS linac upgrading.In addition to the optimization of the RF parameters,the multipacting behavior of the cavity is also studied,and cavity shape is optimized to reduce<SEY>value.
基金Work supported by Project of Basic and Applied Basic Research Fund of Guangdong Province:Yue Guan joint fund(2019B1515120012).
文摘Background A lowβsuperconducting elliptical cavity was designed for the China Spallation Neutron Source phase II project(CSNS-II).Methods The method to improve the mechanical stability of the lowβsuperconducting elliptical cavity was introduced,and the corresponding mechanical design was given.The software COMSOL Multiphysics and ANSYS APDL were used to calculate the static Lorentz force detuning factor k_(L)(LFD)and the helium pressure sensitivity factor k_(p)(DFDP)of the bare cavity,which were−4.71 Hz(MV/m)^(−2) and−21.1 Hz/mbar,respectively.The double-ring stiffeners reinforcement scheme was adopted.Results The radii of the double-ring stiffeners were 70 and 135 mm,respectively.The structure design of the helium vessel of the cavity was given.The following is the mechanical parameters of the reinforced cavity,the tuning sensitivity is 199.8 kHz/mm,longitudinal stiffness is 4.76kN/mm,k_(L) and k_(p) were−1.39 Hz(MV/m)^(−2) and 4.67 Hz/mbar,respectively,which met the operating requirements.The tuning sensitivity and stiffness of the reinforced cavity with different wall thicknesses were optimized,and the final wall thickness was selected as 4 mm.Conclusion The mechanical design of CSNS-II 648 MHz five-cell lowβsuperconducting elliptical cavity was introduced systematically in the paper.The LFD,DFDP,and the maximum surface stress of the cavity were reduced by optimizing the cavity wall thickness and the position of the double-ring stiffeners.The reinforced cavity met operational requirements.
文摘Purpose Superconducting radio frequency(SRF)cavities are adopted to upgrade the CSNS Linac energy from 80 to 300 MeV in phaseⅡ.A 648 MHz single spoke resonator(SSR)prototype has a compact size and low cost,which is a good pre-research cavity for CSNS to learn SRF technology.In this paper,the sequential approach of analysis and optimization performed for the structural design of 648 MHz SSR prototype are presented.Methods The COMSOL Multiphysics is used to perform the multiphysics analysis of jacketed cavity.Firstly,the mechanical performance of bare cavity is estimated,and then,several stiffeners are added to strengthen the cavity.After that,the Lorentz coefficient and helium fluctuation df/dp of jacketed cavity are optimized.At last,the tuning sensitivity and mechanical performance of maximum allowable working pressure are calculated.Results The final results of Lorentz coefficient and df/dp are-5.06 Hz/(MV/m)^(2)and 0.3 Hz/mbar,respectively,and the tuning range of jacketed cavity is larger than±1000 kHz at 2 K.Conclusion The structural design of a 648 MHz SSR prototype is performed in this paper.The Lorentz coefficient and df/dp are carefully optimized.The simulation result shows all mechanical performance satisfies the design goals very well.
基金the Modern Agroindustry Technology Research Systems of China(CARAS-37)the Domain Specific Projects for Transgenic Breeding(2014ZX08010004-008)。
文摘Lactoferrin is a member of the transferrin family of multifunctional iron binding glycoproteins.While numerous physiological functions have been described for lactoferrin,the mechanisms underlying these functions are not clear.To further study the functions and mechanisms of lactoferrin,we modified the lactoferrin promoter of mice using the CRISPR/Cas9 system to reduce or eliminate lactoferrin expression.Seven mice with lactoferrin promoter mutations were obtained with an efficiency of 24%(7/29)by injecting the plasmid pX330,expressing a small guide RNA and human codonoptimized SpCas9,into fertilized eggs of mice.Plasmid integration and off-targeting of pX330 were not detected.These results confirmed that pronuclear injection of a circular plasmid is a feasible and efficient method for targeted mutagenesis in mice.
基金supported by the National Natural Science Foundation of China(No.21673246)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB12020300)
文摘The time-convolutionless （TCL） quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kernel or generator, which describes eflhcts of the bath degrees of freedom. Since the exact TCL generators are usually hard to calculate analytically, most applications of the TCL generalized master equation have relied on approximate generators using second and fourth order perturbative expansions. By using the hierarchical equation of motion （HEOM） and extended HEOM methods, we present a new approach to calculating the exact TCL generator and its high order perturbative expansions. The new approach is applied to the spin-boson model with diflhrent sets of parameters, to investigate the convergence of the high order expansiolls of the TCL generator. We also discuss circumstances where the exact TCL generator becomes singular for the spin-boson model, and a model of excitation energy transfer in the Fenna-Matthews-Olson complex.
