Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yi...Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments.A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018–2020.Lodging-susceptible(LS)cultivars on average yielded more than lodging-resistant(LR)cultivars when lodging was not present.The yield components kernel number per ear(KN)and thousand-kernel weight(TKW)were both negatively correlated with lodging resistance traits(stalk bending strength,rind penetration strength,and dry matter weight per internode length).Before silking,the LR cultivar Lishou 1(LS1)transported more assimilates to the basal stem,resulting in a thicker basal stem,which reduced dry matter allocation to the ear and in turn KN.The lower KN of LS1 was also due partly to the lower plant height(PH),which increased lodging resistance but limited plant dry matter production.In contrast,the LS cultivars Xianyu 335(XY335)and Xundan 20(XD20)produced and allocated more photoassimilates to ears,but limited dry matter allocation to stems.After silking,LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear.The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height(EH).High-yielding and high-LR traits of Fumin(FM985)were related to optimized EH and stem anatomical structure,higher leaf productivity,low assimilate demand for kernel formation,and assimilate partitioning to ear.A high presilking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength.Post-silking temperature influences lodging resistance and yield more than other environmental factors.These results will be useful in understanding the tradeoffs between KN,KW,and LR in maize and environmental influences on these tradeoffs.展开更多
Objective This study investigated the epidemic characteristics and spatio-temporal dynamics of hemorrhagic fever with renal syndrome(HFRS)in Qingdao City,China.Methods Information was collected on HFRS cases in Qingda...Objective This study investigated the epidemic characteristics and spatio-temporal dynamics of hemorrhagic fever with renal syndrome(HFRS)in Qingdao City,China.Methods Information was collected on HFRS cases in Qingdao City from 2010 to 2022.Descriptive epidemiologic,seasonal decomposition,spatial autocorrelation,and spatio-temporal cluster analyses were performed.Results A total of 2,220 patients with HFRS were reported over the study period,with an average annual incidence of 1.89/100,000 and a case fatality rate of 2.52%.The male:female ratio was 2.8:1.75.3%of patients were aged between 16 and 60 years old,75.3%of patients were farmers,and 11.6%had both“three red”and“three pain”symptoms.The HFRS epidemic showed two-peak seasonality:the primary fall-winter peak and the minor spring peak.The HFRS epidemic presented highly spatially heterogeneous,street/township-level hot spots that were mostly distributed in Huangdao,Pingdu,and Jiaozhou.The spatio-temporal cluster analysis revealed three cluster areas in Qingdao City that were located in the south of Huangdao District during the fall-winter peak.Conclusion The distribution of HFRS in Qingdao exhibited periodic,seasonal,and regional characteristics,with high spatial clustering heterogeneity.The typical symptoms of“three red”and“three pain”in patients with HFRS were not obvious.展开更多
Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss pos...Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are available.The RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of precipitation.This dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the simulation.Inaccuracy in reproducing large-scale circulation and environmental conditions is another contributing factor.The too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great Plains.The simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as well.Therefore,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios.展开更多
Mitogen-activated protein kinase(MAPK/MPK)cascades play crucial parts in plant growth,development processes,immune ability,and stress responses;however,the regulatory mechanism by which MAPK affects fruit ripening rem...Mitogen-activated protein kinase(MAPK/MPK)cascades play crucial parts in plant growth,development processes,immune ability,and stress responses;however,the regulatory mechanism by which MAPK affects fruit ripening remains largely unexplored.Here,we reported that MaMPK14 cooperated with MaMYB4 to mediate postharvest banana fruit ripening.Transient overexpression of individual MaMPK14 and MaMYB4 in banana fruit delayed fruit ripening,confirming the negative roles in the ripening.The ripening negative regulator MaMYB4 could repress the transcription of genes associated with ethylene biosynthesis and fruit softening,such as MaACS1,MaXTH5,MaPG3,and MaEXPA15.Furthermore,MaMPK14 phosphorylated MaMYB4 at Ser160 via a direct interaction.Mutation at Ser160 of MaMYB4 reduced its interaction with MaMPK14 but did not affect its subcellular localization.Importantly,phosphorylation of MaMYB4 by MaMPK14 enhanced the MaMYB4-mediated transcriptional inhibition,binding strength,protein stability,and the repression of fruit ripening.Taken together,our results delineated the regulation pathway of MAPK module during banana fruit ripening,which involved the phosphorylation modification of MaMYB4 mediated by MaMPK14.展开更多
Biomimetic neural substitutes,constructed through the bottom-up assembly of cell-matrix modulus via 3D bioprinting,hold great promise for neural regeneration.However,achieving precise control over the fate of neural s...Biomimetic neural substitutes,constructed through the bottom-up assembly of cell-matrix modulus via 3D bioprinting,hold great promise for neural regeneration.However,achieving precise control over the fate of neural stem cells(NSCs)to ensure biological functionality remains challenging.Cell behaviors are closely linked to cellular dynamics and cell-matrix mechanotransduction within a 3D microenvironment.To address this,a dynamic bioactive bioink is designed to provide adaptable biomechanics and instructive biochemical cues,specifically tailored for the fate commitment of NSCs,through incorporating reversible Schiff-base bonds and bioactive motifs,N-cadherin-mimicking and BDNF-mimicking peptides.We demonstrate that the dynamic properties of 3D bioprinted living fibers alleviate the mechanical confinement on NSCs and significantly enhance their mechanosensing,spreading,migration,and matrix remodeling within the 3D matrix.Additionally,the inclusion of N-cadherin-mimicking and BDNF-mimicking peptides further enhances cells’ability to sense and respond to mechanical and neurotrophic cues provided by the surrounding matrix,which accelerates the selforganization of a functional neural network within the 3D bioprinted construct,leading to significant motor and sensory function recovery in a rat complete spinal cord injury model.This work underscores the critical role of precisely designing cell-instructive bioinks for the advanced functionality of 3D bioprinted living constructs in neural regeneration.展开更多
Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equiva...Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equivalent circuit(PEEC)method proposed for lightning-induced electromagnetic pulse(LEMP)simulation is verified using the rocket-triggered experimental results under a more complex line configuration for the first time.This method can improve computational efficiency while ensuring calculation accuracy.The agreement between experimental and simulation results further validates the adaptability and accuracy of the proposed method,which is adopted to calculate the LEMP on the extended double-circuit parallel unequal length line.The effects of various factors,such as the strike-point location,the amplitude and waveform of the lightning current,the line shape and length on the amplitude of overvoltage and pole flashover along the line are discussed.For double-circuit distribution lines,when lightning strikes the ground in front of centre of circuit I,the three-phase voltage waveforms are similar,all of which are negative or bipolar oscillation waves.The closer the lightning strike point is to the line,the greater the amplitude of the lightning current,and the voltage waveform develops towards a bipolar waveform,but the main peak remains negative.As the amplitude of lightning current increases,the maximum lightning-induced voltage amplitude along the line increases.The LEMP caused by the subsequent return-stroke current is always greater than that caused by the first returnstroke current.When the grounding resistance increases,the maximum voltage peak amplitude along the line remains unchanged.展开更多
The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast...The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast sintering techniques offer a solution to inhibit grain coarsening by reducing the processing time.However,the ultrafast preparation of dense ZrB_(2)-based ceramics remains a challenge.In this work,we successfully fabricated dense ZrB_(2)-based ceramics in just a few minutes using heavy continuous direct current(DC)Joule heating and pressing.Notably,the densification rate peaked at 1218℃,and the densification process was nearly complete at a relatively low temperature of 1500℃.The application of heavy continuous direct current not only promotes the densification of the ceramics but also enhances the texturization of ZrB_(2).This results in optimally aligned ZrB_(2) grains that form a three-dimensional bonded skeletal network.These unique microstructures can effectively induce multi-stage fracture surfaces during failure,which helps synergistic strengthening and toughening of the ceramics.The ceramics exhibit remarkable comprehensive mechanical properties,with flexural strength and fracture toughness values reaching 773±114 MPa and 5.88±0.08 MPa·m^(1/2),respectively,surpassing those of conventional hot pressed samples.This technique is expected to be applied to other ultra-high temperature ceramics,providing a promising approach for the development of thermal protection materials.展开更多
The effects of Lactobacillus plantarum in microencapsulation(LPM)on intestinal development in layer chicks were investigated in this study,as well as the colonization of L.plantarum in the gut.A total of 480 healthy H...The effects of Lactobacillus plantarum in microencapsulation(LPM)on intestinal development in layer chicks were investigated in this study,as well as the colonization of L.plantarum in the gut.A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups(8 replicates each treatment),and the diets of these birds were supplemented with nothing(control),L.plantarum(0.02 g/kg feed;10^(9) CFU/kg feed),LPM(1.0 g/kg feed;109 CFU/kg feed)and wall material of LPM(WM;0.98 g/kg feed),respectively.Compared to control,LPM improved growth performance and intestinal development of layer chicks,evidenced by significantly increased body weight,average daily gain,average daily feed intake,villus height,villus height/crypt depth,as well as weight and length of the duodenum,jejunum and ileum(P<0.05).These results could be attributed to the increased colonization of L.plantarum in the gut,which was verified by significant increases in lactic acid content,viable counts in chyme and mucosa(P<0.05),as well as a visible rise in number of strains labeled with fluorescein isothiocyanate.Meanwhile,the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L.plantarum supplementation(P<0.05),accompanied by the significant up-regulation of colonization related genes(P<0.05),encoding solute carrier family,monocarboxylate transporter,activin A receptor,succinate receptor and secretogranin II.To sum up,microencapsulated L.plantarum supplementation promoted intestinal development,which could be attributed to the enhancement of L.plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.展开更多
Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and the...Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and their roles in influencing sugar accumulation in pitayas.HpDof1.7 and HpDof5.4 share a similar expression pattern with sugar metabolism-related genes HpSuSy1 and HpINV2,and sugar transporter genes HpTMT2 and HpSWEET14 during pitayas maturation,and their expression pattern was also consistent with the accumulation of glucose and fructose,which were the predominant sugars in pitayas.HpDof1.7 and HpDof5.4 were both typical nucleus-localized proteins with trans-activation ability.Gel mobility shift assay revealed that HpDof1.7 and HpDof5.4 were bound to promoters of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14.Finally,transient expression assays in tobacco leaves showed that HpDof1.7 and HpDof5.4 increased the activities of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14 promoters,thus facilitating sugar accumulation by transcriptionally enhancing sugar metabolic pathway genes.Our findings provide a new perspective on the regulatory mechanisms of Dof transcription factors in sugar accumulation and pitaya fruit quality formation.展开更多
Industrial parks(IPs)play a crucial role in facilitating economic efficiency and comprehensive energy utilization in the industrial age.At the same time,multi-energy coupling and management of various types of energy ...Industrial parks(IPs)play a crucial role in facilitating economic efficiency and comprehensive energy utilization in the industrial age.At the same time,multi-energy coupling and management of various types of energy in IP have become serious challenges.In this paper,combined heat and power unit(CHP)model considering operation mode switching characteristics is formulated by exploring its internal composition to improve output flexibility of the energy supply side.Then,heat and electricity integrated energy system(HE-IES)optimal dispatch and pricing model are established,taking electricity and heat demand response strategy and steam thermal inertia property into account.Based on the above models,a mixed-integer bilinear programming framework is designed to coordinate the day-ahead operation and pricing strategy of the HE-IES in the IP.The scenario study is carried out on a practical industrial park in Southern China.Numerical results indicate the proposed mechanism can effectively improve IP’s energy utilization and economic efficiency.展开更多
A visible light-mediated approach for the preparation of α-bromo-α,β-unsaturated ketones and aldehydes was developed. In comparison to traditional methods that generally take two steps to afford the above compounds...A visible light-mediated approach for the preparation of α-bromo-α,β-unsaturated ketones and aldehydes was developed. In comparison to traditional methods that generally take two steps to afford the above compounds, this protocol was highlighted by its operational simplicity, avoiding using hazardous bromine and mild reaction conditions.展开更多
To the Editor:Fibrous mediastinitis(FM)is a rare group of diseases characterized by excessive proliferation of fibrous tissue in the mediastinum,which can cause bronchial stenosis,superior vena cava(SVC)obstruction,an...To the Editor:Fibrous mediastinitis(FM)is a rare group of diseases characterized by excessive proliferation of fibrous tissue in the mediastinum,which can cause bronchial stenosis,superior vena cava(SVC)obstruction,and pulmonary artery(PA)and vein(PV)stenosis.Moreover,long-term obstruction of PAs and PVs may lead to pulmonary hypertension(PH),right heart failure(RHF),and death.[1]Although it is generally held that FM is an aberrant immunoproliferative response of the mediastinum to a triggering factor,such as infection of Mycobacterium tuberculosis and Histoplasma capsulatum,the exact etiology and pathogenesis of FM remain unclear;in particular,the genetic susceptibility of this fatal disease is unknown.展开更多
基金supported by the project of National Key Research and Development Program of China(2016YFD0300301 and 2017YFD0300603)The 2115 Talent Development Program of China Agricultural University。
文摘Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments.A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018–2020.Lodging-susceptible(LS)cultivars on average yielded more than lodging-resistant(LR)cultivars when lodging was not present.The yield components kernel number per ear(KN)and thousand-kernel weight(TKW)were both negatively correlated with lodging resistance traits(stalk bending strength,rind penetration strength,and dry matter weight per internode length).Before silking,the LR cultivar Lishou 1(LS1)transported more assimilates to the basal stem,resulting in a thicker basal stem,which reduced dry matter allocation to the ear and in turn KN.The lower KN of LS1 was also due partly to the lower plant height(PH),which increased lodging resistance but limited plant dry matter production.In contrast,the LS cultivars Xianyu 335(XY335)and Xundan 20(XD20)produced and allocated more photoassimilates to ears,but limited dry matter allocation to stems.After silking,LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear.The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height(EH).High-yielding and high-LR traits of Fumin(FM985)were related to optimized EH and stem anatomical structure,higher leaf productivity,low assimilate demand for kernel formation,and assimilate partitioning to ear.A high presilking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength.Post-silking temperature influences lodging resistance and yield more than other environmental factors.These results will be useful in understanding the tradeoffs between KN,KW,and LR in maize and environmental influences on these tradeoffs.
基金supported by the Chinese Field Epidemiology Training Program,the Research and Development of Standards and Standardization of Nomenclature in the Field of Public Health-Research Project on the Development of the Disciplines of Public Health and Preventive Medicine[242402]the Shandong Medical and Health Science and Technology Development Plan[202112050731].
文摘Objective This study investigated the epidemic characteristics and spatio-temporal dynamics of hemorrhagic fever with renal syndrome(HFRS)in Qingdao City,China.Methods Information was collected on HFRS cases in Qingdao City from 2010 to 2022.Descriptive epidemiologic,seasonal decomposition,spatial autocorrelation,and spatio-temporal cluster analyses were performed.Results A total of 2,220 patients with HFRS were reported over the study period,with an average annual incidence of 1.89/100,000 and a case fatality rate of 2.52%.The male:female ratio was 2.8:1.75.3%of patients were aged between 16 and 60 years old,75.3%of patients were farmers,and 11.6%had both“three red”and“three pain”symptoms.The HFRS epidemic showed two-peak seasonality:the primary fall-winter peak and the minor spring peak.The HFRS epidemic presented highly spatially heterogeneous,street/township-level hot spots that were mostly distributed in Huangdao,Pingdu,and Jiaozhou.The spatio-temporal cluster analysis revealed three cluster areas in Qingdao City that were located in the south of Huangdao District during the fall-winter peak.Conclusion The distribution of HFRS in Qingdao exhibited periodic,seasonal,and regional characteristics,with high spatial clustering heterogeneity.The typical symptoms of“three red”and“three pain”in patients with HFRS were not obvious.
文摘Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are available.The RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of precipitation.This dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the simulation.Inaccuracy in reproducing large-scale circulation and environmental conditions is another contributing factor.The too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great Plains.The simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as well.Therefore,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios.
基金This work was funded by the National Natural Science Foundation of China(Grant No.31830071)China Agriculture Research System of Ministry of Finance(MOF)and Ministry of Agriculture and Rural affairs(MARA)(Grant No.CARS-31).
文摘Mitogen-activated protein kinase(MAPK/MPK)cascades play crucial parts in plant growth,development processes,immune ability,and stress responses;however,the regulatory mechanism by which MAPK affects fruit ripening remains largely unexplored.Here,we reported that MaMPK14 cooperated with MaMYB4 to mediate postharvest banana fruit ripening.Transient overexpression of individual MaMPK14 and MaMYB4 in banana fruit delayed fruit ripening,confirming the negative roles in the ripening.The ripening negative regulator MaMYB4 could repress the transcription of genes associated with ethylene biosynthesis and fruit softening,such as MaACS1,MaXTH5,MaPG3,and MaEXPA15.Furthermore,MaMPK14 phosphorylated MaMYB4 at Ser160 via a direct interaction.Mutation at Ser160 of MaMYB4 reduced its interaction with MaMPK14 but did not affect its subcellular localization.Importantly,phosphorylation of MaMYB4 by MaMPK14 enhanced the MaMYB4-mediated transcriptional inhibition,binding strength,protein stability,and the repression of fruit ripening.Taken together,our results delineated the regulation pathway of MAPK module during banana fruit ripening,which involved the phosphorylation modification of MaMYB4 mediated by MaMPK14.
基金support from the National Natural Science Foundation of China(Grant No.32271414 and 82301560)support from State Key Laboratory of New Ceramic Materials Tsinghua University(No.KF202409).
文摘Biomimetic neural substitutes,constructed through the bottom-up assembly of cell-matrix modulus via 3D bioprinting,hold great promise for neural regeneration.However,achieving precise control over the fate of neural stem cells(NSCs)to ensure biological functionality remains challenging.Cell behaviors are closely linked to cellular dynamics and cell-matrix mechanotransduction within a 3D microenvironment.To address this,a dynamic bioactive bioink is designed to provide adaptable biomechanics and instructive biochemical cues,specifically tailored for the fate commitment of NSCs,through incorporating reversible Schiff-base bonds and bioactive motifs,N-cadherin-mimicking and BDNF-mimicking peptides.We demonstrate that the dynamic properties of 3D bioprinted living fibers alleviate the mechanical confinement on NSCs and significantly enhance their mechanosensing,spreading,migration,and matrix remodeling within the 3D matrix.Additionally,the inclusion of N-cadherin-mimicking and BDNF-mimicking peptides further enhances cells’ability to sense and respond to mechanical and neurotrophic cues provided by the surrounding matrix,which accelerates the selforganization of a functional neural network within the 3D bioprinted construct,leading to significant motor and sensory function recovery in a rat complete spinal cord injury model.This work underscores the critical role of precisely designing cell-instructive bioinks for the advanced functionality of 3D bioprinted living constructs in neural regeneration.
基金supported by National Natural Science Foundation of China(No.52507193).
文摘Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equivalent circuit(PEEC)method proposed for lightning-induced electromagnetic pulse(LEMP)simulation is verified using the rocket-triggered experimental results under a more complex line configuration for the first time.This method can improve computational efficiency while ensuring calculation accuracy.The agreement between experimental and simulation results further validates the adaptability and accuracy of the proposed method,which is adopted to calculate the LEMP on the extended double-circuit parallel unequal length line.The effects of various factors,such as the strike-point location,the amplitude and waveform of the lightning current,the line shape and length on the amplitude of overvoltage and pole flashover along the line are discussed.For double-circuit distribution lines,when lightning strikes the ground in front of centre of circuit I,the three-phase voltage waveforms are similar,all of which are negative or bipolar oscillation waves.The closer the lightning strike point is to the line,the greater the amplitude of the lightning current,and the voltage waveform develops towards a bipolar waveform,but the main peak remains negative.As the amplitude of lightning current increases,the maximum lightning-induced voltage amplitude along the line increases.The LEMP caused by the subsequent return-stroke current is always greater than that caused by the first returnstroke current.When the grounding resistance increases,the maximum voltage peak amplitude along the line remains unchanged.
基金supported by the Natural Science Basic Research Program of Shaanxi(Nos.2024JC-YBQN-0580 and 2020JM-599)Shaanxi Province’s Key Research and Development Project(No.2023-YBGY-172)+1 种基金the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.24JK0360)the Graduate Scientific Research Foundation of Shaanxi Univerisity of Technology(No.SLGYCX2401).
文摘The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast sintering techniques offer a solution to inhibit grain coarsening by reducing the processing time.However,the ultrafast preparation of dense ZrB_(2)-based ceramics remains a challenge.In this work,we successfully fabricated dense ZrB_(2)-based ceramics in just a few minutes using heavy continuous direct current(DC)Joule heating and pressing.Notably,the densification rate peaked at 1218℃,and the densification process was nearly complete at a relatively low temperature of 1500℃.The application of heavy continuous direct current not only promotes the densification of the ceramics but also enhances the texturization of ZrB_(2).This results in optimally aligned ZrB_(2) grains that form a three-dimensional bonded skeletal network.These unique microstructures can effectively induce multi-stage fracture surfaces during failure,which helps synergistic strengthening and toughening of the ceramics.The ceramics exhibit remarkable comprehensive mechanical properties,with flexural strength and fracture toughness values reaching 773±114 MPa and 5.88±0.08 MPa·m^(1/2),respectively,surpassing those of conventional hot pressed samples.This technique is expected to be applied to other ultra-high temperature ceramics,providing a promising approach for the development of thermal protection materials.
基金financed by the National Key Research and Development Program of China (2021YFD1300300)the National Natural Science Foundation of China (32202697)+1 种基金Key Technology Research and Development Program of Henan Province (232102111041)the Innovation Fund of Henan University of Technology (2022ZKCJ17).
文摘The effects of Lactobacillus plantarum in microencapsulation(LPM)on intestinal development in layer chicks were investigated in this study,as well as the colonization of L.plantarum in the gut.A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups(8 replicates each treatment),and the diets of these birds were supplemented with nothing(control),L.plantarum(0.02 g/kg feed;10^(9) CFU/kg feed),LPM(1.0 g/kg feed;109 CFU/kg feed)and wall material of LPM(WM;0.98 g/kg feed),respectively.Compared to control,LPM improved growth performance and intestinal development of layer chicks,evidenced by significantly increased body weight,average daily gain,average daily feed intake,villus height,villus height/crypt depth,as well as weight and length of the duodenum,jejunum and ileum(P<0.05).These results could be attributed to the increased colonization of L.plantarum in the gut,which was verified by significant increases in lactic acid content,viable counts in chyme and mucosa(P<0.05),as well as a visible rise in number of strains labeled with fluorescein isothiocyanate.Meanwhile,the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L.plantarum supplementation(P<0.05),accompanied by the significant up-regulation of colonization related genes(P<0.05),encoding solute carrier family,monocarboxylate transporter,activin A receptor,succinate receptor and secretogranin II.To sum up,microencapsulated L.plantarum supplementation promoted intestinal development,which could be attributed to the enhancement of L.plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.
基金unded by the Key Science and Technology Planning Project of Guangzhou(No.201904020015)the Science and Technology Program of Guangzhou(No.202002020060)the Science and Technology Program of Zhanjiang(No.2019A01003),China.
文摘Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and their roles in influencing sugar accumulation in pitayas.HpDof1.7 and HpDof5.4 share a similar expression pattern with sugar metabolism-related genes HpSuSy1 and HpINV2,and sugar transporter genes HpTMT2 and HpSWEET14 during pitayas maturation,and their expression pattern was also consistent with the accumulation of glucose and fructose,which were the predominant sugars in pitayas.HpDof1.7 and HpDof5.4 were both typical nucleus-localized proteins with trans-activation ability.Gel mobility shift assay revealed that HpDof1.7 and HpDof5.4 were bound to promoters of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14.Finally,transient expression assays in tobacco leaves showed that HpDof1.7 and HpDof5.4 increased the activities of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14 promoters,thus facilitating sugar accumulation by transcriptionally enhancing sugar metabolic pathway genes.Our findings provide a new perspective on the regulatory mechanisms of Dof transcription factors in sugar accumulation and pitaya fruit quality formation.
基金supported by the National Natural Science Foundation of China(No.52177077)by the Science and Technology Project of State Grid Jiangsu Electric Power Co.,Ltd.,Grant J20210148.
文摘Industrial parks(IPs)play a crucial role in facilitating economic efficiency and comprehensive energy utilization in the industrial age.At the same time,multi-energy coupling and management of various types of energy in IP have become serious challenges.In this paper,combined heat and power unit(CHP)model considering operation mode switching characteristics is formulated by exploring its internal composition to improve output flexibility of the energy supply side.Then,heat and electricity integrated energy system(HE-IES)optimal dispatch and pricing model are established,taking electricity and heat demand response strategy and steam thermal inertia property into account.Based on the above models,a mixed-integer bilinear programming framework is designed to coordinate the day-ahead operation and pricing strategy of the HE-IES in the IP.The scenario study is carried out on a practical industrial park in Southern China.Numerical results indicate the proposed mechanism can effectively improve IP’s energy utilization and economic efficiency.
基金supported by the National Natural Science Foundation of China(2100201821072038+3 种基金2147203021302029)the State Key Laboratory of Urban Water Resource and Environment(2015DX01)the Fundamental Research Funds for the Central Universities(HIT.BRETIV.201310)
文摘A visible light-mediated approach for the preparation of α-bromo-α,β-unsaturated ketones and aldehydes was developed. In comparison to traditional methods that generally take two steps to afford the above compounds, this protocol was highlighted by its operational simplicity, avoiding using hazardous bromine and mild reaction conditions.
基金supported by grants from the National Natural Science Foundation of China(Nos.82070052 and U25A2001)the Tianjin high-level talent selection and training project in the health industry(No.TJSJMYXYC-D2-042)+1 种基金the Natural Science Foundation of Gansu Province of China(No.24JRRA1049)the Lanzhou Science and Technology Program of Gansu Province of China(No.LX-62000001-2022-090).
文摘To the Editor:Fibrous mediastinitis(FM)is a rare group of diseases characterized by excessive proliferation of fibrous tissue in the mediastinum,which can cause bronchial stenosis,superior vena cava(SVC)obstruction,and pulmonary artery(PA)and vein(PV)stenosis.Moreover,long-term obstruction of PAs and PVs may lead to pulmonary hypertension(PH),right heart failure(RHF),and death.[1]Although it is generally held that FM is an aberrant immunoproliferative response of the mediastinum to a triggering factor,such as infection of Mycobacterium tuberculosis and Histoplasma capsulatum,the exact etiology and pathogenesis of FM remain unclear;in particular,the genetic susceptibility of this fatal disease is unknown.
