[Objectives]The paper was to evaluate the effectiveness of Xiulijing in the management of rust in Golden Delicious apple cultivation.[Methods]The Golden Delicious apple was utilized as the test material.During the you...[Objectives]The paper was to evaluate the effectiveness of Xiulijing in the management of rust in Golden Delicious apple cultivation.[Methods]The Golden Delicious apple was utilized as the test material.During the young fruit stage,various dilutions of Xiulijing were applied,specifically at concentrations of 200,400,600,800,1000,and 2000 times.Additionally,both the application of a 3000-fold dilution of GA 4+7 and the practice of fruit bagging were designated as the control treatments,while a water spray was utilized as the blank control.The fruit rust index and the incidence of rust-infected fruits were evaluated to assess the effectiveness of control measures for fruit rust in Golden Delicious apple cultivation.[Results]The application of Xiulijing,with dilutions ranging from 200 to 2000 times,exhibited a significant impact on reducing both the fruit rust index and the incidence of rust-infected fruits in Golden Delicious apples.The application of a 1000-fold dilution of Xiulijing resulted in a statistically significant reduction in both the fruit rust index and the incidence of rust-infected fruits,with reduction rates of 21.1%and 31.5%,respectively.Among the various strategies for the prevention and control of apple rust,fruit bagging emerged as the most effective method.The other two technical measures demonstrated significant control effects;however,no substantial differences were observed between them.[Conclusions]The biological control agent Xiulijing is more deserving of promotion and application in practical production due to its significantly superior economic benefits,safety,and stability.展开更多
Cigar line Beinhart 1000-1 has effective durable resistance to black shank(BS) and is considered one of the most resistant sources in tobacco(Nicotiana tabacum L.). To investigate the inheritance and identification of...Cigar line Beinhart 1000-1 has effective durable resistance to black shank(BS) and is considered one of the most resistant sources in tobacco(Nicotiana tabacum L.). To investigate the inheritance and identification of stable quantitative trait loci(QTL) for BS response, F2,BC1 F2 individuals and BC1 F2:3 lines were produced from a cross between Beinhart 1000-1 and Xiaohuangjin 1025. Two major quantitative trait loci(M-QTL) named qBS7 and qBS17 were repeatedly detected under different conditions. QTL qBS7 was mapped to the region between PT30174 and PT60621 and explained 17.40%–25.60% of the phenotypic variance under different conditions. The other QTL qBS17 in interval PT61564–PT61538 of linkage group 17 was detected in a BC1 F2 population in the field and in BC1 F2:3 in both the field and at the seedling stage, explaining 6.90% to 11.60% of the phenotypic variance. The results improve our understanding of the inheritance of resistance to BS and provide information that can be used in marker-assisted breeding.展开更多
In order to study the influence of three-grid assembly thermal deformation caused by heat accumulation on breakdown times and an ion extraction process,a hot gap test and a breakdown time test are carried out to obtai...In order to study the influence of three-grid assembly thermal deformation caused by heat accumulation on breakdown times and an ion extraction process,a hot gap test and a breakdown time test are carried out to obtain thermal deformation of the grids when the thruster is in 5 k W operation mode.Meanwhile,the fluid simulation method and particle-in-cell-Monte Carlo collision(PICMCC) method are adopted to simulate the ion extraction process according to the previous test results.The numerical calculation results are verified by the ion thruster performance test.The results show that after about 1.2 h operation,the hot gap between the screen grid and the accelerator grid reduce to 0.25–0.3 mm,while the hot gap between the accelerator grid and the decelerator grid increase from 1 mm to about 1.4 mm when the grids reach thermal equilibrium,and the hot gap is almost unchanged.In addition,the breakdown times experiment shows that 0.26 mm is the minimal safe hot gap for the grid assembly as the breakdown times improves significantly when the gap is smaller than this value.Fluid simulation results show that the plasma density of the screen grid is in the range 6?×10^(17)–6?×?10^(18) m^(13) and displays a parabolic characteristic,while the electron temperature gradually increases along the axial direction.The PIC-MCC results show that the current falling of an ion beam through a single aperture is significant.Meanwhile,the intercepted current of the accelerator grid and the decelerator grid both increase with the change in the hot gap.The ion beam current has optimal perveance status without thermal deformation,and the intercepted current of the accelerator grid and the decelerator grid are 3.65 m A and 6.26 m A,respectively.Furthermore,under the effect of thermal deformation,the ion beam current has over-perveance status,and the intercepted current of the accelerator grid and the decelerator grid are 10.46 m A and 18.24 m A,respectively.Performance test results indicate that the breakdown times increase obviously.The intercepted current of the accelerator grid and the decelerator grid increases to 13 m A and 16.5 m A,respectively,due to the change in the hot gap after 1.5 h operation.The numerical calculation results are well consistent with performance test results,and the error comes mainly from the test uncertainty of the hot gap.展开更多
The grid structure has significant effects on the discharge characteristics of an ion thruster.The discharge performances of a 30 cm diameter ion thruster with flat,convex and concave grids are studied.The analysis re...The grid structure has significant effects on the discharge characteristics of an ion thruster.The discharge performances of a 30 cm diameter ion thruster with flat,convex and concave grids are studied.The analysis results show that the discharge chamber with a convex grid has a larger’magnetic-field free area’than the others,and the parallelism of the magnetic-field isopotential lines and anode is generally the same in the three models.Plasma densities of the three structures at the grid outlet are in the range of 3.1×1016-6.9×1017m-3.Along the thruster axis direction,the electron temperature in the chamber with the convex and concave grids is in the range of 3.3-3.5 eV,while that with a flat grid is lower,in the range of 3.1-3.5 eV.In addition,the convex and the concave grids have better uniform distribution of electron temperature.Moreover,the collision frequency ratios show that the axial degree of ionization of the three models is the highest,and the flat grid has the highest discharge efficiency,followed by the convex grid and the concave grid is the least efficient.The test and simulation results of the 30 cm diameter ion thruster with the convex grid show that the measurement and calculation results are 3.67 A and 3.44 A,respectively,and the error above mainly comes from the ignorance of the doubly charged ions and parameter settings in the model.The comparison error between the simulation and measurement of beam current density is mainly caused by the actual thermal deformation of the grids during the discharge process,which leads to the change in electric potential distribution and variation of the focusing characteristics of the grids.Upon consideration of discharge performance and the thermal grid gap variation,it can be concluded that the flat and concave grids are more suitable for small-diameter ion thrusters,while the convex grid is a more reasonable choice for the higher-power and larger-diameter thrusters.展开更多
The accurate knowledge of the thrust vector eccentricity and beam divergence characteristics of Hall thrusters are of significant engineering value for the beneficial integration and successful application of Hall thr...The accurate knowledge of the thrust vector eccentricity and beam divergence characteristics of Hall thrusters are of significant engineering value for the beneficial integration and successful application of Hall thrusters on spacecraft.For the characteristics of the plume bipolar diffusion due to the annular discharge channel of the Hall thruster,a Gaussian-fitted method for thrust vector deviation angle and beam divergence of Hall thrusters based on dual Faraday probe array planes was proposed in respect of the Hall thruster beam characteristics.The results show that the ratios of the deviation between the maximum and minimum values of the beam divergence angle and the thrust vector eccentricity angle using a Gaussian fit to the optimized Faraday probe dual plane to the mean value are 1.4%and 11.5%,respectively.The optimized thrust vector eccentricity angle obtained has been substantially improved,by approximately 20%.The beam divergence angle calculated using a Gaussian fitting to the optimized Faraday probe dual plane is approximately identical to the non-optimized one.The beam divergence and thrust vector eccentricity angles for different anode mass flow rates were obtained by averaging the beam divergence and thrust vector eccentricity angles calculated by the dual-plane,Gaussian-fitted ion current density method for different cross-sections.The study not only allows for an immediate and effective tool for determining the design of thrust vector adjustment mechanisms of spacecraft with different power Hall thrusters but also for characterizing the 3D spatial distribution of the Hall thruster plume.展开更多
Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via r...Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.展开更多
In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to ana...In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to analyze the five failure factors that lead to the failure of the accelerator grid of a 30 cm diameter ion thruster under the working mode of 5 k W.Meanwhile,the acceleration stress levels corresponding to different failure factors are obtained.The results show that background pressure has the highest stress level on the grid's erosion.The accelerator grid aperture's mass sputtering rate under the rated vacuum degree(1×10^(-4)Pa)of 5 k W work mode is 8.78 times that of the baseline vacuum degree(1×10^(-6)Pa),and the mass sputtering rate under worse vacuum degree(5×10^(-3)Pa)is 5.08 times that of 1×10^(-4)Pa.Under the influence of the other four failure factors,namely,the voltage of the accelerator grid,upstream plasma density,the screen grid voltage and mass utilization efficiency,the mass sputtering rates of the accelerator grid hole are 2.32,2.67,1.98 and 2.51 times those of the accelerator grid hole under baseline condition,respectively.The ion sputtering results of two 30 cm diameter ion thrusters(both installed with new grids assembly)after working for 1000 h show that the mass sputtering rate of the accelerator grid hole under vacuum conditions of 5×10^(-3)Pa is 4.54 times that under the condition of 1×10^(-4)Pa,and the comparison error between simulation results and test results of acceleration stress is about 10%.In the subsequent ion thruster lifetime verification,the working vacuum degree can be adjusted according to the acceleration stress level of background pressure,so as to shorten the test time and reduce the test cost.展开更多
Soils are not exempt from anthropogenic pollution,which can eventually cause disturbance of the microbial communities and areas without any kind of productivity.Among soil microbiota,bacteria play an important role in...Soils are not exempt from anthropogenic pollution,which can eventually cause disturbance of the microbial communities and areas without any kind of productivity.Among soil microbiota,bacteria play an important role in pollutant degradation,enabling them to thrive in contaminated sites.Given this,several techniques have been used to increase the number of pollutantdegrading bacteria in situ or for subsequent addition.Additionally,bacteriophages exhibit a high tolerance to pollutants and enhance bacterial metabolic activity through phage-encoded auxiliary metabolic genes(AMGs),thereby augmenting their skills for nutrient assimilation,resistance to phage infection,antibiotic resistance,heavy metal resistance,and degradation of pesticides and xenobiotics,among others.Several phage-encoded AMGs have been described during the last few years,but their diversity,distribution,and function have not been extensively explored,warranting further studies.Here,we highlight soil microbiome interactions,especially bacterium and phage interactions to understand this unexplored world with a high potential for restoring polluted soils.展开更多
Polycyclic aromatic hydrocarbons(PAHs)/heavy metals/fluorine(F) mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this s...Polycyclic aromatic hydrocarbons(PAHs)/heavy metals/fluorine(F) mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this study was initiated to investigate the feasibility of using carboxymethyl-β-cyclodextrin(CMCD) and carboxymethyl chitosan(CMC) solution to enhance ex situ soil washing for extracting mixed contaminants. Further,Tenax extraction method was combined with a first-three-compartment model to evaluate the environmental risk of residual PAHs in washed soil. In addition,the redistribution of heavy metals/F after decontamination was also estimated using a sequential extraction procedure. Three successive washing cycles using50 g/L CMCD and 5 g/L CMC solution were effective to remove 94.3% of total PAHs,93.2% of Pb,85.8% of Cd,93.4% of Cr,83.2% of Ni and 97.3% of F simultaneously. After the 3rd washing,the residual PAHs mainly existed as very slowly desorbing fractions,which were in the form of well-aged,well-sequestered compounds; while the remaining Pb,Cd,Cr,Ni and F mainly existed as Fe–Mn oxide and residual fractions,which were always present in stable mineral forms or bound to non-labile soil fractions. Therefore,this combined cleanup strategy proved to be effective and environmentally friendly.展开更多
Given the opposing effects of Akt and AMP-activated protein kinase(AMPK)on metabolic homeostasis,this study examined the effects of deletion of Akt2 and AMPKα2 on fat diet-induced hepatic steatosis.Akt2–Ampkα2 doub...Given the opposing effects of Akt and AMP-activated protein kinase(AMPK)on metabolic homeostasis,this study examined the effects of deletion of Akt2 and AMPKα2 on fat diet-induced hepatic steatosis.Akt2–Ampkα2 double knockout(DKO)mice were placed on high fat diet for 5 months.Glucose metabolism,energy homeostasis,cardiac function,lipid accumulation,and hepatic steatosis were examined.DKO mice were lean without anthropometric defects.High fat intake led to adiposity and decreased respiratory exchange ratio(RER)in wild-type(WT)mice,which were ablated in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.High fat intake increased blood and hepatic triglycerides and cholesterol,promoted hepatic steatosis and injury in WT mice.These effects were eliminated in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.Fat diet promoted fat accumulation,and enlarged adipocyte size,the effect was negated in DKO mice.Fat intake elevated fatty acid synthase(FAS),carbohydrate-responsive element-binding protein(CHREBP),sterol regulatory element-binding protein 1(SREBP1),peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC-1α),peroxisome proliferator-activated receptor-α(PPARα),PPARγ,stearoyl-CoA desaturase 1(SCD-1),phosphoenolpyruvate carboxykinase(PEPCK),glucose 6-phosphatase(G6Pase),and diglyceride O-acyltransferase 1(DGAT1),the effect was absent in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.Fat diet dampened mitophagy,promoted inflammation and phosphorylation of forkhead box protein O1(FoxO1)and AMPKα1(Ser^(485)),the effects were eradicated by DKO.Deletion of Parkin effectively nullified DKO-induced metabolic benefits against high fat intake.Liver samples from obese humans displayed lowered microtubule-associated proteins 1A/1B light chain 3B(LC3B),Pink1,Parkin,as well as enhanced phosphorylation of Akt,AMPK(Ser^(485)),and FoxO1,which were consolidated by RNA sequencing(RNAseq)and mass spectrometry analyses from rodent and human livers.These data suggest that concurrent deletion of Akt2 and AMPKα2 offers resilience to fat diet-induced obesity and hepatic steatosis,possibly through preservation of Parkin-mediated mitophagy and lipid metabolism.展开更多
Dissipation and plant uptake of polycyclic aromatic hydrocarbons (PAHs) in contaminated agricul- tural soil planted with perennial ryegrass were investigated in a field experiment. After two seasons of grass cultiva...Dissipation and plant uptake of polycyclic aromatic hydrocarbons (PAHs) in contaminated agricul- tural soil planted with perennial ryegrass were investigated in a field experiment. After two seasons of grass cultivation the mean concentration of 12 PAHs in soil decreased by 23.4% compared with the initial soil. The 3-, 4-, 5-, and 6- ring PAHs were dissipated by 30.9%, 25.5%, 21.2%, and 16.3% from the soil, respectively. Ryegrass shoots accumulated about 280 ug.kg1, shoot dry matter biomass reached 2.48 x 104kg-ha1, and plant uptake accounted for about 0.99% of the decrease in PAHs in the soil. Significantly higher soil enzyme activities and microbial community functional diversity were observed in planted soil than that in the unplanted control. The results suggest that planting ryegrass may promote the dissipation of PAHs in long-term contaminated agricultural soil, and plant-promoted microbial degradation may be a main mechanism of phytoremediation.展开更多
Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6...Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6)is highly expressed in lung cancer and is required for cell metabolism,tumorigenicity,and cisplatin response of lung cancer.PRMT6 regulated the oxidative pentose phosphate pathway(PPP)flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phosphogluconate dehydrogenase(6PGD)and a-enolase(ENO1).Furthermore,PRMT6 methylated R324 of 6PGD to enhancing its activity;while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate(2-PG)binding to ENO1,respectively.Lastly,targeting PRMT6 blocked the oxidative PPP flux,glycolysis pathway,and tumor growth,as well as enhanced the antitumor effects of cisplatin in lung cancer.Together,this study demonstrates that PRMT6 acts as a posttranslational modification(PTM)regulator of glucose metabolism,which leads to the pathogenesis of lung cancer.It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.展开更多
In this paper,through an emulsion-based bottom-up self-assembly method,monodisperse CdS_(x)Se_(1-x)(x=0-1)quantum dots(QDs)with tailoring compositions have been three-dimensionally assembled into spherical architectur...In this paper,through an emulsion-based bottom-up self-assembly method,monodisperse CdS_(x)Se_(1-x)(x=0-1)quantum dots(QDs)with tailoring compositions have been three-dimensionally assembled into spherical architectures in sub-micrometer sizes.UVeVis absorption measurements revealed the enhanced light harvesting abilities of the assembled CdS_(x)Se_(1-x) spheres relative to their constituting QDs.HRTEM characterizations over the CdS_(x)Se_(1-x) assemblies suggested the existence of localized oriented adjoining of the CdS_(x)Se_(1-x) QDs and the resulting nano-twin structures that are favorable for photogenerated electron-hole separation.The quenching of photoluminescence and the improvement in IPCE after the assembly of CdS_(x)Se_(1-x) QDs provided a clue to the likely suppressed electron-hole recombination brought about by the unique architectures and interfaces derived from self-assembly.The above findings were coincided with the remarkably improved H2 evolution activities observed for the wellassembled CdS_(x)Se_(1-x) nanospheres in photocatalytic water splitting,underpinning the importance of the alternative strategy to design advanced semiconductor photocatalysts based on architectural engineering.展开更多
Benefitting from the tunable heterogeneous interface and electronic interaction, metal-polymer-based hybrid composites have attracted wide attention. It is highly desired to develop advanced synthesis methodology and ...Benefitting from the tunable heterogeneous interface and electronic interaction, metal-polymer-based hybrid composites have attracted wide attention. It is highly desired to develop advanced synthesis methodology and understand the structure-performance relationship. Herein, with the aniline oligomer as the key enabler, we resolve the inferior dynamics issue in the Ag+-aniline reaction system, and successfully fabricate a sub-micron anisotropic eccentric Ag@polyaniline(PANI) particle(an average size up to 340 nm) at room temperature. We demonstrate the synergy mechanism of polyvinyl pyrrolidone and insitu generated PANI for modifying the dynamic reaction interface. We further clarify the H+concentration and the surfactant types serve as main descriptors to tune the reaction dynamics. Besides, by applying other aniline oligomers, a series of similar eccentric structures can also be obtained, indicative of the good applicability of our strategy. Such a sub-micron eccentric structure furnishes the Ag@PANI composites with sound performance for microwave absorption, as demonstrated by a minimum reflection loss(RL) value of-35 d B with an effective absorption bandwidth of 3.7 GHz. This study provides an inspiring scope/concept of eccentric microstructure engineering for better meeting the demands in the high-tech military, energy, environment fields, and beyond.展开更多
The authors of the above-mentioned paper noticed an error in Fig.5a as reported.H&E staining was shown in wrong color during figure processing and DKO-LF group was accidently copied and pasted twice.Original H&...The authors of the above-mentioned paper noticed an error in Fig.5a as reported.H&E staining was shown in wrong color during figure processing and DKO-LF group was accidently copied and pasted twice.Original H&E images have been replaced with the correct color with the accurate grouping information.No text content in figure legend or conclusion is affected by this error.The authors sincerely apologize for any inconvenience caused to the journal and readers.展开更多
Background Monoclonal antibodies such as rituximab(RTX),eculizumab,inebilizumab,satralizumab,and tocilizumab have been found to be effective therapies for neuromyelitis optica spectrum disease(NMOSD)in several clinica...Background Monoclonal antibodies such as rituximab(RTX),eculizumab,inebilizumab,satralizumab,and tocilizumab have been found to be effective therapies for neuromyelitis optica spectrum disease(NMOSD)in several clinical randomized controlled trials.Objective The purpose of this meta-analysis of randomized controlled trials was to assess the efficacy and safety of monoclonal antibodies in the treatment of NMOSD.Methods We searched the following databases for relevant English language literature from the establishment of the database to June 2021:PubMed,Embase,Cohorane Library,the Central Register of Controlled Trials(CENTRAL),and Web of Science.Randomized controlled trials of monoclonal antibodies were the targets of the review.Results We included seven trials containing 775 patients(485 in the monoclonal antibody group and 290 in the control group).Patients in the monoclonal group(HR 0.24,95%CI:0.14 to 0.40,P<0.00001),as well as patients with seropositive AQP4-IgG(HR 0.18,95%CI:0.11 to 0.29,P<0.00001),both had a higher free recurrence rate than that in the control group.In the first year(HR 0.25,95%CI:0.09 to 0.71,P=0.009)and the second year(HR 0.32,95%CI:0.13 to 0.81,P=0.02),no relapses were documented.The average changes of the expanded disability status scale(EDSS)score decreased by 0.29(95%CI:−0.09 to 0.51,P=0.005).Upper respiratory tract infection(OR 1.52,95%CI:0.76 to 3.04,P=0.24),urinary tract infection(OR 0.79,95%CI:0.51 to 1.21,P=0.27),and headache(OR 1.30,95%CI:0.78 to 2.17,P=0.31)were three most frequent adverse reactions.Conclusions Monoclonal antibodies are particularly effective treatments in avoiding recurrence for NMOSD patients,according to this meta-analysis.The associated adverse responses are not significantly different from those seen with traditional immunosuppressants.展开更多
文摘[Objectives]The paper was to evaluate the effectiveness of Xiulijing in the management of rust in Golden Delicious apple cultivation.[Methods]The Golden Delicious apple was utilized as the test material.During the young fruit stage,various dilutions of Xiulijing were applied,specifically at concentrations of 200,400,600,800,1000,and 2000 times.Additionally,both the application of a 3000-fold dilution of GA 4+7 and the practice of fruit bagging were designated as the control treatments,while a water spray was utilized as the blank control.The fruit rust index and the incidence of rust-infected fruits were evaluated to assess the effectiveness of control measures for fruit rust in Golden Delicious apple cultivation.[Results]The application of Xiulijing,with dilutions ranging from 200 to 2000 times,exhibited a significant impact on reducing both the fruit rust index and the incidence of rust-infected fruits in Golden Delicious apples.The application of a 1000-fold dilution of Xiulijing resulted in a statistically significant reduction in both the fruit rust index and the incidence of rust-infected fruits,with reduction rates of 21.1%and 31.5%,respectively.Among the various strategies for the prevention and control of apple rust,fruit bagging emerged as the most effective method.The other two technical measures demonstrated significant control effects;however,no substantial differences were observed between them.[Conclusions]The biological control agent Xiulijing is more deserving of promotion and application in practical production due to its significantly superior economic benefits,safety,and stability.
基金supported by grants from the Agricultural Science and Technology Innovation Program (ASTIP-TRIC01)National Natural Science Foundation of China (31571738)
文摘Cigar line Beinhart 1000-1 has effective durable resistance to black shank(BS) and is considered one of the most resistant sources in tobacco(Nicotiana tabacum L.). To investigate the inheritance and identification of stable quantitative trait loci(QTL) for BS response, F2,BC1 F2 individuals and BC1 F2:3 lines were produced from a cross between Beinhart 1000-1 and Xiaohuangjin 1025. Two major quantitative trait loci(M-QTL) named qBS7 and qBS17 were repeatedly detected under different conditions. QTL qBS7 was mapped to the region between PT30174 and PT60621 and explained 17.40%–25.60% of the phenotypic variance under different conditions. The other QTL qBS17 in interval PT61564–PT61538 of linkage group 17 was detected in a BC1 F2 population in the field and in BC1 F2:3 in both the field and at the seedling stage, explaining 6.90% to 11.60% of the phenotypic variance. The results improve our understanding of the inheritance of resistance to BS and provide information that can be used in marker-assisted breeding.
基金supported by the National Key Laboratory Fund of Science and Technology on Vacuum Technology & Physics (Grant No.6142207030103)National Natural Science Foundation of China (Grant No.11702123)
文摘In order to study the influence of three-grid assembly thermal deformation caused by heat accumulation on breakdown times and an ion extraction process,a hot gap test and a breakdown time test are carried out to obtain thermal deformation of the grids when the thruster is in 5 k W operation mode.Meanwhile,the fluid simulation method and particle-in-cell-Monte Carlo collision(PICMCC) method are adopted to simulate the ion extraction process according to the previous test results.The numerical calculation results are verified by the ion thruster performance test.The results show that after about 1.2 h operation,the hot gap between the screen grid and the accelerator grid reduce to 0.25–0.3 mm,while the hot gap between the accelerator grid and the decelerator grid increase from 1 mm to about 1.4 mm when the grids reach thermal equilibrium,and the hot gap is almost unchanged.In addition,the breakdown times experiment shows that 0.26 mm is the minimal safe hot gap for the grid assembly as the breakdown times improves significantly when the gap is smaller than this value.Fluid simulation results show that the plasma density of the screen grid is in the range 6?×10^(17)–6?×?10^(18) m^(13) and displays a parabolic characteristic,while the electron temperature gradually increases along the axial direction.The PIC-MCC results show that the current falling of an ion beam through a single aperture is significant.Meanwhile,the intercepted current of the accelerator grid and the decelerator grid both increase with the change in the hot gap.The ion beam current has optimal perveance status without thermal deformation,and the intercepted current of the accelerator grid and the decelerator grid are 3.65 m A and 6.26 m A,respectively.Furthermore,under the effect of thermal deformation,the ion beam current has over-perveance status,and the intercepted current of the accelerator grid and the decelerator grid are 10.46 m A and 18.24 m A,respectively.Performance test results indicate that the breakdown times increase obviously.The intercepted current of the accelerator grid and the decelerator grid increases to 13 m A and 16.5 m A,respectively,due to the change in the hot gap after 1.5 h operation.The numerical calculation results are well consistent with performance test results,and the error comes mainly from the test uncertainty of the hot gap.
基金National Natural Science Foundation of China(No.61901202)Key Laboratory Funds for the Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics(No.HTKJ2019KL510003)。
文摘The grid structure has significant effects on the discharge characteristics of an ion thruster.The discharge performances of a 30 cm diameter ion thruster with flat,convex and concave grids are studied.The analysis results show that the discharge chamber with a convex grid has a larger’magnetic-field free area’than the others,and the parallelism of the magnetic-field isopotential lines and anode is generally the same in the three models.Plasma densities of the three structures at the grid outlet are in the range of 3.1×1016-6.9×1017m-3.Along the thruster axis direction,the electron temperature in the chamber with the convex and concave grids is in the range of 3.3-3.5 eV,while that with a flat grid is lower,in the range of 3.1-3.5 eV.In addition,the convex and the concave grids have better uniform distribution of electron temperature.Moreover,the collision frequency ratios show that the axial degree of ionization of the three models is the highest,and the flat grid has the highest discharge efficiency,followed by the convex grid and the concave grid is the least efficient.The test and simulation results of the 30 cm diameter ion thruster with the convex grid show that the measurement and calculation results are 3.67 A and 3.44 A,respectively,and the error above mainly comes from the ignorance of the doubly charged ions and parameter settings in the model.The comparison error between the simulation and measurement of beam current density is mainly caused by the actual thermal deformation of the grids during the discharge process,which leads to the change in electric potential distribution and variation of the focusing characteristics of the grids.Upon consideration of discharge performance and the thermal grid gap variation,it can be concluded that the flat and concave grids are more suitable for small-diameter ion thrusters,while the convex grid is a more reasonable choice for the higher-power and larger-diameter thrusters.
基金the Key Laboratory Funds for Science and Technology on Vacuum Technology and Physics Laboratory(No.HTKJ2022KL510002)the Military Test Instruments Program(No.2006ZCTF0054)。
文摘The accurate knowledge of the thrust vector eccentricity and beam divergence characteristics of Hall thrusters are of significant engineering value for the beneficial integration and successful application of Hall thrusters on spacecraft.For the characteristics of the plume bipolar diffusion due to the annular discharge channel of the Hall thruster,a Gaussian-fitted method for thrust vector deviation angle and beam divergence of Hall thrusters based on dual Faraday probe array planes was proposed in respect of the Hall thruster beam characteristics.The results show that the ratios of the deviation between the maximum and minimum values of the beam divergence angle and the thrust vector eccentricity angle using a Gaussian fit to the optimized Faraday probe dual plane to the mean value are 1.4%and 11.5%,respectively.The optimized thrust vector eccentricity angle obtained has been substantially improved,by approximately 20%.The beam divergence angle calculated using a Gaussian fitting to the optimized Faraday probe dual plane is approximately identical to the non-optimized one.The beam divergence and thrust vector eccentricity angles for different anode mass flow rates were obtained by averaging the beam divergence and thrust vector eccentricity angles calculated by the dual-plane,Gaussian-fitted ion current density method for different cross-sections.The study not only allows for an immediate and effective tool for determining the design of thrust vector adjustment mechanisms of spacecraft with different power Hall thrusters but also for characterizing the 3D spatial distribution of the Hall thruster plume.
基金supported by Chinese Academy of Sciences,China(Grant No.QYZDY-SSW-SLH013-2)Henan Normal University,China。
文摘Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.
基金supported by Key Laboratory Funds for the Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics(Nos.HTKJ2022KL510003 and 6142207210303)Independent project of Hangzhou Institute for Advanced Study(No.2022ZZ01009)Science and Technology Project Affiliated to the Education Department of Chongqing Municipality(No.KJZD-K202101506)。
文摘In view of the high cost caused by the 1:1 lifetime verification test of ion thrusters,the lifetime acceleration test should be considered.This work uses the PIC-MCC(Particle-in-Cell MonteCarlo Collision)method to analyze the five failure factors that lead to the failure of the accelerator grid of a 30 cm diameter ion thruster under the working mode of 5 k W.Meanwhile,the acceleration stress levels corresponding to different failure factors are obtained.The results show that background pressure has the highest stress level on the grid's erosion.The accelerator grid aperture's mass sputtering rate under the rated vacuum degree(1×10^(-4)Pa)of 5 k W work mode is 8.78 times that of the baseline vacuum degree(1×10^(-6)Pa),and the mass sputtering rate under worse vacuum degree(5×10^(-3)Pa)is 5.08 times that of 1×10^(-4)Pa.Under the influence of the other four failure factors,namely,the voltage of the accelerator grid,upstream plasma density,the screen grid voltage and mass utilization efficiency,the mass sputtering rates of the accelerator grid hole are 2.32,2.67,1.98 and 2.51 times those of the accelerator grid hole under baseline condition,respectively.The ion sputtering results of two 30 cm diameter ion thrusters(both installed with new grids assembly)after working for 1000 h show that the mass sputtering rate of the accelerator grid hole under vacuum conditions of 5×10^(-3)Pa is 4.54 times that under the condition of 1×10^(-4)Pa,and the comparison error between simulation results and test results of acceleration stress is about 10%.In the subsequent ion thruster lifetime verification,the working vacuum degree can be adjusted according to the acceleration stress level of background pressure,so as to shorten the test time and reduce the test cost.
基金the European Union’s Horizon Europe 2020 Research and Innovation Program under the Marie Skłodowska-Curie(No.101106707)Generalitat de Catalunya through Consolidated Research Group 2021 SGR 01282 and from the CERCA program.
文摘Soils are not exempt from anthropogenic pollution,which can eventually cause disturbance of the microbial communities and areas without any kind of productivity.Among soil microbiota,bacteria play an important role in pollutant degradation,enabling them to thrive in contaminated sites.Given this,several techniques have been used to increase the number of pollutantdegrading bacteria in situ or for subsequent addition.Additionally,bacteriophages exhibit a high tolerance to pollutants and enhance bacterial metabolic activity through phage-encoded auxiliary metabolic genes(AMGs),thereby augmenting their skills for nutrient assimilation,resistance to phage infection,antibiotic resistance,heavy metal resistance,and degradation of pesticides and xenobiotics,among others.Several phage-encoded AMGs have been described during the last few years,but their diversity,distribution,and function have not been extensively explored,warranting further studies.Here,we highlight soil microbiome interactions,especially bacterium and phage interactions to understand this unexplored world with a high potential for restoring polluted soils.
基金supported by the National Natural Science Foundation of China (Nos.41030531,41001335G,21377138 and 41271464b)
文摘Polycyclic aromatic hydrocarbons(PAHs)/heavy metals/fluorine(F) mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this study was initiated to investigate the feasibility of using carboxymethyl-β-cyclodextrin(CMCD) and carboxymethyl chitosan(CMC) solution to enhance ex situ soil washing for extracting mixed contaminants. Further,Tenax extraction method was combined with a first-three-compartment model to evaluate the environmental risk of residual PAHs in washed soil. In addition,the redistribution of heavy metals/F after decontamination was also estimated using a sequential extraction procedure. Three successive washing cycles using50 g/L CMCD and 5 g/L CMC solution were effective to remove 94.3% of total PAHs,93.2% of Pb,85.8% of Cd,93.4% of Cr,83.2% of Ni and 97.3% of F simultaneously. After the 3rd washing,the residual PAHs mainly existed as very slowly desorbing fractions,which were in the form of well-aged,well-sequestered compounds; while the remaining Pb,Cd,Cr,Ni and F mainly existed as Fe–Mn oxide and residual fractions,which were always present in stable mineral forms or bound to non-labile soil fractions. Therefore,this combined cleanup strategy proved to be effective and environmentally friendly.
基金supported in part by the National Key R&D Program of China(2017YFA0506000)National Natural Science Foundation of China(82000351)。
文摘Given the opposing effects of Akt and AMP-activated protein kinase(AMPK)on metabolic homeostasis,this study examined the effects of deletion of Akt2 and AMPKα2 on fat diet-induced hepatic steatosis.Akt2–Ampkα2 double knockout(DKO)mice were placed on high fat diet for 5 months.Glucose metabolism,energy homeostasis,cardiac function,lipid accumulation,and hepatic steatosis were examined.DKO mice were lean without anthropometric defects.High fat intake led to adiposity and decreased respiratory exchange ratio(RER)in wild-type(WT)mice,which were ablated in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.High fat intake increased blood and hepatic triglycerides and cholesterol,promoted hepatic steatosis and injury in WT mice.These effects were eliminated in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.Fat diet promoted fat accumulation,and enlarged adipocyte size,the effect was negated in DKO mice.Fat intake elevated fatty acid synthase(FAS),carbohydrate-responsive element-binding protein(CHREBP),sterol regulatory element-binding protein 1(SREBP1),peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC-1α),peroxisome proliferator-activated receptor-α(PPARα),PPARγ,stearoyl-CoA desaturase 1(SCD-1),phosphoenolpyruvate carboxykinase(PEPCK),glucose 6-phosphatase(G6Pase),and diglyceride O-acyltransferase 1(DGAT1),the effect was absent in DKO but not Akt2^(-/-) and Ampkα2^(-/-) mice.Fat diet dampened mitophagy,promoted inflammation and phosphorylation of forkhead box protein O1(FoxO1)and AMPKα1(Ser^(485)),the effects were eradicated by DKO.Deletion of Parkin effectively nullified DKO-induced metabolic benefits against high fat intake.Liver samples from obese humans displayed lowered microtubule-associated proteins 1A/1B light chain 3B(LC3B),Pink1,Parkin,as well as enhanced phosphorylation of Akt,AMPK(Ser^(485)),and FoxO1,which were consolidated by RNA sequencing(RNAseq)and mass spectrometry analyses from rodent and human livers.These data suggest that concurrent deletion of Akt2 and AMPKα2 offers resilience to fat diet-induced obesity and hepatic steatosis,possibly through preservation of Parkin-mediated mitophagy and lipid metabolism.
基金Acknowledgements This work was supported by grants from the National High Technology Research and Development Program of China (863 Program) (No. 2007AA061110), the Knowledge Innovation of the Chinese Academy of Sciences (Project KSCX2-YW-G-071) and the Natural Science Foundation of Jiangsu Province (Project BK2009016).
文摘Dissipation and plant uptake of polycyclic aromatic hydrocarbons (PAHs) in contaminated agricul- tural soil planted with perennial ryegrass were investigated in a field experiment. After two seasons of grass cultivation the mean concentration of 12 PAHs in soil decreased by 23.4% compared with the initial soil. The 3-, 4-, 5-, and 6- ring PAHs were dissipated by 30.9%, 25.5%, 21.2%, and 16.3% from the soil, respectively. Ryegrass shoots accumulated about 280 ug.kg1, shoot dry matter biomass reached 2.48 x 104kg-ha1, and plant uptake accounted for about 0.99% of the decrease in PAHs in the soil. Significantly higher soil enzyme activities and microbial community functional diversity were observed in planted soil than that in the unplanted control. The results suggest that planting ryegrass may promote the dissipation of PAHs in long-term contaminated agricultural soil, and plant-promoted microbial degradation may be a main mechanism of phytoremediation.
基金supported by grants from the Natural Science Foundation of Tianjin(21JCZDJC00060,China)the National Nature Science Foundation of China(81973356,91957120,81902826,and 81672781)+4 种基金the Fundamental Research Funds for the Central Universities of Nankai University(3206054,91923101,63213082 and 92122017,China)the State Key Laboratory of Drug Research(SIMM2105KF-08,China)the National Key R&D Program of China(No.2018YFC2002000)the Innovative S&T Projects for Young Researchers of Tianjin Academy of Agricultural Science(grant No.201918,China)the Natural Science Foundation of Tianjin(19JCYBJC29600 and 21JCYBJC00180,China)。
文摘Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6)is highly expressed in lung cancer and is required for cell metabolism,tumorigenicity,and cisplatin response of lung cancer.PRMT6 regulated the oxidative pentose phosphate pathway(PPP)flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phosphogluconate dehydrogenase(6PGD)and a-enolase(ENO1).Furthermore,PRMT6 methylated R324 of 6PGD to enhancing its activity;while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate(2-PG)binding to ENO1,respectively.Lastly,targeting PRMT6 blocked the oxidative PPP flux,glycolysis pathway,and tumor growth,as well as enhanced the antitumor effects of cisplatin in lung cancer.Together,this study demonstrates that PRMT6 acts as a posttranslational modification(PTM)regulator of glucose metabolism,which leads to the pathogenesis of lung cancer.It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.
基金This work was supported by the National Natural Science Foundation of China(Grant No.21322105,51501010,91323301,51372025).
文摘In this paper,through an emulsion-based bottom-up self-assembly method,monodisperse CdS_(x)Se_(1-x)(x=0-1)quantum dots(QDs)with tailoring compositions have been three-dimensionally assembled into spherical architectures in sub-micrometer sizes.UVeVis absorption measurements revealed the enhanced light harvesting abilities of the assembled CdS_(x)Se_(1-x) spheres relative to their constituting QDs.HRTEM characterizations over the CdS_(x)Se_(1-x) assemblies suggested the existence of localized oriented adjoining of the CdS_(x)Se_(1-x) QDs and the resulting nano-twin structures that are favorable for photogenerated electron-hole separation.The quenching of photoluminescence and the improvement in IPCE after the assembly of CdS_(x)Se_(1-x) QDs provided a clue to the likely suppressed electron-hole recombination brought about by the unique architectures and interfaces derived from self-assembly.The above findings were coincided with the remarkably improved H2 evolution activities observed for the wellassembled CdS_(x)Se_(1-x) nanospheres in photocatalytic water splitting,underpinning the importance of the alternative strategy to design advanced semiconductor photocatalysts based on architectural engineering.
基金the support and funding from the National Natural Science Foundation of China(Nos.51673156,52202301)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2022JQ-143)+1 种基金China Postdoctoral Science Foundation(No.2022TQ0256)the Fundamental Research Funds for the Central Universities(No.D5000210607)。
文摘Benefitting from the tunable heterogeneous interface and electronic interaction, metal-polymer-based hybrid composites have attracted wide attention. It is highly desired to develop advanced synthesis methodology and understand the structure-performance relationship. Herein, with the aniline oligomer as the key enabler, we resolve the inferior dynamics issue in the Ag+-aniline reaction system, and successfully fabricate a sub-micron anisotropic eccentric Ag@polyaniline(PANI) particle(an average size up to 340 nm) at room temperature. We demonstrate the synergy mechanism of polyvinyl pyrrolidone and insitu generated PANI for modifying the dynamic reaction interface. We further clarify the H+concentration and the surfactant types serve as main descriptors to tune the reaction dynamics. Besides, by applying other aniline oligomers, a series of similar eccentric structures can also be obtained, indicative of the good applicability of our strategy. Such a sub-micron eccentric structure furnishes the Ag@PANI composites with sound performance for microwave absorption, as demonstrated by a minimum reflection loss(RL) value of-35 d B with an effective absorption bandwidth of 3.7 GHz. This study provides an inspiring scope/concept of eccentric microstructure engineering for better meeting the demands in the high-tech military, energy, environment fields, and beyond.
文摘The authors of the above-mentioned paper noticed an error in Fig.5a as reported.H&E staining was shown in wrong color during figure processing and DKO-LF group was accidently copied and pasted twice.Original H&E images have been replaced with the correct color with the accurate grouping information.No text content in figure legend or conclusion is affected by this error.The authors sincerely apologize for any inconvenience caused to the journal and readers.
基金supported by the Ministry of Science and Technology of the People's Republic of China Core Project(2018YFE0113900).
文摘Background Monoclonal antibodies such as rituximab(RTX),eculizumab,inebilizumab,satralizumab,and tocilizumab have been found to be effective therapies for neuromyelitis optica spectrum disease(NMOSD)in several clinical randomized controlled trials.Objective The purpose of this meta-analysis of randomized controlled trials was to assess the efficacy and safety of monoclonal antibodies in the treatment of NMOSD.Methods We searched the following databases for relevant English language literature from the establishment of the database to June 2021:PubMed,Embase,Cohorane Library,the Central Register of Controlled Trials(CENTRAL),and Web of Science.Randomized controlled trials of monoclonal antibodies were the targets of the review.Results We included seven trials containing 775 patients(485 in the monoclonal antibody group and 290 in the control group).Patients in the monoclonal group(HR 0.24,95%CI:0.14 to 0.40,P<0.00001),as well as patients with seropositive AQP4-IgG(HR 0.18,95%CI:0.11 to 0.29,P<0.00001),both had a higher free recurrence rate than that in the control group.In the first year(HR 0.25,95%CI:0.09 to 0.71,P=0.009)and the second year(HR 0.32,95%CI:0.13 to 0.81,P=0.02),no relapses were documented.The average changes of the expanded disability status scale(EDSS)score decreased by 0.29(95%CI:−0.09 to 0.51,P=0.005).Upper respiratory tract infection(OR 1.52,95%CI:0.76 to 3.04,P=0.24),urinary tract infection(OR 0.79,95%CI:0.51 to 1.21,P=0.27),and headache(OR 1.30,95%CI:0.78 to 2.17,P=0.31)were three most frequent adverse reactions.Conclusions Monoclonal antibodies are particularly effective treatments in avoiding recurrence for NMOSD patients,according to this meta-analysis.The associated adverse responses are not significantly different from those seen with traditional immunosuppressants.