Phytomelatonin,an emerging plant hormone,plays vital roles in plant growth,development,and stress adaptation(Arnao et al.,2022;Ullah et al.,2024).It acts both as a direct antioxidant and a signaling molecule,engaging ...Phytomelatonin,an emerging plant hormone,plays vital roles in plant growth,development,and stress adaptation(Arnao et al.,2022;Ullah et al.,2024).It acts both as a direct antioxidant and a signaling molecule,engaging complex networks and interacting with other phytohormones(Liu et al.,2022;Khan et al.,2023).Although phytomelatonin receptors(PMTRs)have been identified in many plants(Wei et al.,2018;Wang et al.,2022;Liu et al.,2025),the downstream signaling mechanisms,particularly receptor-mediated protein modifications and transcriptional regulation,remain poorly characterized.展开更多
In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. U...In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.展开更多
In this study, we provide the first detailed analysis of variations in the spacecraft potential (Vs) of the three Swarm satellites, which are flying at about 400-500 km. Unlike previous studies that have investigated ...In this study, we provide the first detailed analysis of variations in the spacecraft potential (Vs) of the three Swarm satellites, which are flying at about 400-500 km. Unlike previous studies that have investigated extreme charging events, usually with spacecraft potentials as negative as −100 V, this study is focused on variations of Swarm Vs readings, which fall within a few negative volts. The Swarm observations show that spacecraft at low Earth orbital (LEO) altitudes are charged only slightly negatively, varying between −7 V and 0 V, with the majority of recorded potentials at these altitudes clustering close to −2 V. However, a second peak of Vs data is found at −5.5 V, though the event numbers for these more-negative observations are less, by an order of magnitude, than for incidents near the −2 V peak. These two distinct Vs peaks suggest two different causes. We have thus divided the Swarm spacecraft Vs data into two categories: less-negatively charged (−5 < Vs < 0 V) and more-negatively-charged (−6.5 < Vs < −5 V). These two Vs categories exhibit different spatial and temporal distributions. The Vs observations in the first category remain relatively closer to 0 V above the magnetic equator, but become much more negative at low and middle latitudes on the day side;at high latitudes, these first-category Vs readings are relatively more-negative during local summer. Second-category Vs events cluster into two bands at the middle latitudes (between ±20°-50° magnetic latitude), but with slightly more negative readings at the South Atlantic Anomaly (SAA) region;at high latitudes, these rarer but more-negative second-category Vs events exhibit relatively more-negative values during local winter, which is opposite to the seasonal pattern seen in the first category. By comparing Vs data to the distributions of background plasma density at Swarm altitudes, we find for the first category that more-negative Vs readings are recorded at regions with higher background plasma density, while for the second category the more-negative Vs data are observed at regions with lower background plasma density. This can be explained as follows: the electron and ion fluxes incident on Swarm surface, whose differences determine the potential of Swarm, are dominated by the background “cold” plasma (due to ionization) and “hot” plasma (due to precipitated particles from magnetosphere) for the two Vs categories, respectively.展开更多
The deliberate and precise fabrication of supported catalysts with well-defined structures has been a long-standing pursuit.Among the large number of supports for anchoring noble metal species,layered double hydroxide...The deliberate and precise fabrication of supported catalysts with well-defined structures has been a long-standing pursuit.Among the large number of supports for anchoring noble metal species,layered double hydroxides(LDHs)stand out as a class of ideal supports for dispersing noble metal species due to their uniform distribution of metal sites and charge centers.However,a prerequisite for the investigation of noble metals-loaded LDHs is the construction of well-defined active sites and precisely controlled sizes of noble metal species on LDH surfaces.Based on research advances made over the past decade,we provide a detailed discussion on the fine regulation of noble metal species,including single atoms,nanoclusters,nanoparticles,and multi-site catalysts on LDHs.Furthermore,we focus on uncovering three critical aspects of noble metal-loaded LDHs:the precise location,the atomic configurations,and the interaction with the LDHs.Building upon these well-defined structures,we further clarify the structure-activity relationships of the developed materials in reactions such as hydrazine decomposition,biomass conversion,C–H bond activation,and water splitting,etc.Finally,the challenges and future directions are outlined to offer valuable insights for advancing high-activity noble metal-loaded LDHs.展开更多
Antibacterial piezoelectric materials have broad application prospects in the medical field because of their broadspectrum antibacterial properties and no bacterial drug resistance.At present,one of the main problems ...Antibacterial piezoelectric materials have broad application prospects in the medical field because of their broadspectrum antibacterial properties and no bacterial drug resistance.At present,one of the main problems in the application of piezoelectric materials is the low electrocatalytic efficiency,which limits its application in anti-bacterial field.In this study,a piezoelectric antibacterial(PLGA/Zn-KNN)scaffold was fabricated by incorpo-rating zinc oxide(ZnO)into potassium-sodium niobate(KNN)and composited with a poly(lactic-co-glycolic acid)(PLGA)to achieve multicombination antibacterial for bone infection.The physicochemical properties of piezoelectric antibacterial scaffolds were analyzed.Bacterial,cell,and animal experiments were performed to characterize the antibacterial and infection treatment capabilities of piezoelectric scaffolds.The piezoelectric properties of the PLGA/Zn-KNN scaffold were enhanced by embedding ZnO particles into the KNN solid solution matrix.Furthermore,the piezoelectric scaffold released zinc ions,and electrical stimulation driven by ultrasound resulted in significant antibacterial effects through direct and immunoregulatory antibacterial pathways.Mechanistic investigation suggested that extracellular matrix ligands and complement and coagulation cascades may have a moderate effect on macrophage phagocytosis.This work highlights potential application methods for fabricating novel antibacterial hybrid piezoelectric scaffolds and engineering macrophages with immunoregu-latory antibacterial activity.展开更多
Supercells are the most severe and long-lasting type of highly organized convective storms,with the greatest potential for producing extreme weather events and causing significant disasters.This article provides a com...Supercells are the most severe and long-lasting type of highly organized convective storms,with the greatest potential for producing extreme weather events and causing significant disasters.This article provides a comprehensive overview and recent highlights of supercell research,including the unique structure,environmental characteristics,and the formation and maintenance mechanisms of the mesocyclone.Buoyancy instability is a necessary ingredient in the supercell’s environment,whereas dynamic factors such as vertical wind shear and low-level storm relative helicity are more sensitive parameters for distinguishing supercells from non-supercells.The near-storm environmental parameters derived from multi-sensor observations are expected to enhance high-resolution nowcasting of supercell storms.Different types of supercells,including those producing distinct hazardous weather,exhibit unique reflectivity morphology and dynamical/microphysical structures,e.g.,tornadic supercells have a strong low-level mesocyclone while severe hail supercells feature a strong and deep mesocyclone.Mesocyclones associated with damaging winds are accompanied by significant mid-level radial convergence,while those responsible for heavy precipitation are typically located at low levels.The vertical vorticity of the mesocyclone is generated through the tilting of environmental horizontal vorticity by storm-related intense updrafts.The horizontal vorticity that tilts into the mid-level mesocyclone originates from the environmental vertical wind shear,which produces the horizontal vorticity along the inflow to the storms.In contrast,the horizontal vorticity contributing to the low-level mesocyclone derives from two distinct mechanisms,i.e.,environmental vertical shear in the boundary layer and gust front-induced baroclinicity.It remains unclear which mechanism is more dominant.Moreover,the maintenance and enhancement mechanisms of mesocyclones are complex and vary across different scenarios,particularly when embedded within heavy precipitation,during storm mergers,or in proximity to surface mesoscale boundaries(e.g.,fronts,drylines,gust fronts,and their associated convergence lines).In recent years,based on super high-resolution numerical experiment results,the physical conceptual models of the supercell tornadogenesis have been updated.The newly revealed microphysical and dynamic characteristics from polarimetric Doppler radar observations enable more accurate hail size detection.However,the refined physical conceptual model of severe hail growth still requires improvement,and our understanding of the formation mechanisms behind extreme wind gusts and flash floods associated with supercells remains limited.展开更多
T follicular helper(Tfh)cells specialize in facilitating germinal center B-cell activation and high-affinity antibody generation,which are crucial in humoral immune responses.However,aberrant control of Tfh cells also...T follicular helper(Tfh)cells specialize in facilitating germinal center B-cell activation and high-affinity antibody generation,which are crucial in humoral immune responses.However,aberrant control of Tfh cells also contributes to the generation of self-reactive autoantibodies and promotes autoimmune diseases such as systemic lupus erythematosus(SLE).The mechanisms that control proper Tfh expansion remain unclear.Here,we show that farnesoid X receptor(FXR)is relatively upregulated in Tfh cells.Genetic deletion of Fxr restrains Tfh expansion both at steady state and in pristane-induced lupus.As a consequence of these defects,mice lacking Fxr manifested GC dysfunction and decreased plasma cell and autoantibody production,which alleviated nephritis progression in pristane-induced lupus.Mechanistically,FXR intrinsically regulates cholesterol homeostasis in Tfh cells,which subsequently controls Tfh cell proliferation.Preclinical treatment of wild-type(WT)mice with the clinically approved drug ursodeoxycholic acid(UDCA)to reduce FXR signaling mitigated lupus disease progression by repressing Tfh expansion,the GC reaction and autoantibody production.These findings provide a rationale for exploring FXR as a potential therapeutic target for SLE.展开更多
The intensity changes of tropical cyclones(TCs)are a key focus in TC research community and pose significant challenges for operational forecasting.Water vapor plays a crucial role in the variations of TC intensity.Th...The intensity changes of tropical cyclones(TCs)are a key focus in TC research community and pose significant challenges for operational forecasting.Water vapor plays a crucial role in the variations of TC intensity.This paper reviews and summarizes representative findings regarding the influence of water vapor on TC intensity.The discussion primarily covers the impact of water vapor sources,transport,distribution,budget,and phase changes on TC intensity.However,critical scientific challenges remain,including establishing quantitative thresholds for dry and cold air intrusion,understanding microphysical and dynamic interaction mechanisms in high-resolution models,and developing advanced moist thermodynamic approaches.Addressing these challenges is essential for advancing research and improving forecasts of the impact of water vapor on TC intensity.展开更多
基金supported by the grants from the Key Research and Development Program of Xinjiang Uygur autonomous region in China(Grant No.2023B02017)the National Key Research and Development Program of China(Grant No.2024YFD2300703)+1 种基金the financial support from the Beijing Rural Revitalization Agricultural Science and Technology Project(Grant No.NY2401080000),BAIC01-2025the 2115 Talent Development Program of China Agricultural University.
文摘Phytomelatonin,an emerging plant hormone,plays vital roles in plant growth,development,and stress adaptation(Arnao et al.,2022;Ullah et al.,2024).It acts both as a direct antioxidant and a signaling molecule,engaging complex networks and interacting with other phytohormones(Liu et al.,2022;Khan et al.,2023).Although phytomelatonin receptors(PMTRs)have been identified in many plants(Wei et al.,2018;Wang et al.,2022;Liu et al.,2025),the downstream signaling mechanisms,particularly receptor-mediated protein modifications and transcriptional regulation,remain poorly characterized.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503700)the special funds of Hubei Luojia Laboratory (220100011)+1 种基金Chao Xiong is supported by the ISSI-BJ project, “the electromagnetic data validation and scientific application research based on CSES satellite”ISSI/ISSI-BJ project “Multi-Scale Magnetosphere–Ionosphere–Thermosphere Interaction”。
文摘In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503700)the special found of Hubei Luojia Laboratory (220100011)supported by the Dragon 5 cooperation 2020-2024 (project no. 59236)
文摘In this study, we provide the first detailed analysis of variations in the spacecraft potential (Vs) of the three Swarm satellites, which are flying at about 400-500 km. Unlike previous studies that have investigated extreme charging events, usually with spacecraft potentials as negative as −100 V, this study is focused on variations of Swarm Vs readings, which fall within a few negative volts. The Swarm observations show that spacecraft at low Earth orbital (LEO) altitudes are charged only slightly negatively, varying between −7 V and 0 V, with the majority of recorded potentials at these altitudes clustering close to −2 V. However, a second peak of Vs data is found at −5.5 V, though the event numbers for these more-negative observations are less, by an order of magnitude, than for incidents near the −2 V peak. These two distinct Vs peaks suggest two different causes. We have thus divided the Swarm spacecraft Vs data into two categories: less-negatively charged (−5 < Vs < 0 V) and more-negatively-charged (−6.5 < Vs < −5 V). These two Vs categories exhibit different spatial and temporal distributions. The Vs observations in the first category remain relatively closer to 0 V above the magnetic equator, but become much more negative at low and middle latitudes on the day side;at high latitudes, these first-category Vs readings are relatively more-negative during local summer. Second-category Vs events cluster into two bands at the middle latitudes (between ±20°-50° magnetic latitude), but with slightly more negative readings at the South Atlantic Anomaly (SAA) region;at high latitudes, these rarer but more-negative second-category Vs events exhibit relatively more-negative values during local winter, which is opposite to the seasonal pattern seen in the first category. By comparing Vs data to the distributions of background plasma density at Swarm altitudes, we find for the first category that more-negative Vs readings are recorded at regions with higher background plasma density, while for the second category the more-negative Vs data are observed at regions with lower background plasma density. This can be explained as follows: the electron and ion fluxes incident on Swarm surface, whose differences determine the potential of Swarm, are dominated by the background “cold” plasma (due to ionization) and “hot” plasma (due to precipitated particles from magnetosphere) for the two Vs categories, respectively.
基金supported by the National Natural Science Foundation of China(22178019,22208013,22288102)the Fundamental Research Funds for the Central Universities(XK1802-6,XK1803-05,XK1902)。
文摘The deliberate and precise fabrication of supported catalysts with well-defined structures has been a long-standing pursuit.Among the large number of supports for anchoring noble metal species,layered double hydroxides(LDHs)stand out as a class of ideal supports for dispersing noble metal species due to their uniform distribution of metal sites and charge centers.However,a prerequisite for the investigation of noble metals-loaded LDHs is the construction of well-defined active sites and precisely controlled sizes of noble metal species on LDH surfaces.Based on research advances made over the past decade,we provide a detailed discussion on the fine regulation of noble metal species,including single atoms,nanoclusters,nanoparticles,and multi-site catalysts on LDHs.Furthermore,we focus on uncovering three critical aspects of noble metal-loaded LDHs:the precise location,the atomic configurations,and the interaction with the LDHs.Building upon these well-defined structures,we further clarify the structure-activity relationships of the developed materials in reactions such as hydrazine decomposition,biomass conversion,C–H bond activation,and water splitting,etc.Finally,the challenges and future directions are outlined to offer valuable insights for advancing high-activity noble metal-loaded LDHs.
基金supported by grants from the Key R&D Projects of the Science and Technology Development Plan of Jilin Province,China(20220204126YY)the Medical and Health Talent Special Project of Jilin Province,China(JLSWSRCZX2023-32)the Natural Science Foundation Discipline Layout Project of Jilin Province,China(20200201478JC).
文摘Antibacterial piezoelectric materials have broad application prospects in the medical field because of their broadspectrum antibacterial properties and no bacterial drug resistance.At present,one of the main problems in the application of piezoelectric materials is the low electrocatalytic efficiency,which limits its application in anti-bacterial field.In this study,a piezoelectric antibacterial(PLGA/Zn-KNN)scaffold was fabricated by incorpo-rating zinc oxide(ZnO)into potassium-sodium niobate(KNN)and composited with a poly(lactic-co-glycolic acid)(PLGA)to achieve multicombination antibacterial for bone infection.The physicochemical properties of piezoelectric antibacterial scaffolds were analyzed.Bacterial,cell,and animal experiments were performed to characterize the antibacterial and infection treatment capabilities of piezoelectric scaffolds.The piezoelectric properties of the PLGA/Zn-KNN scaffold were enhanced by embedding ZnO particles into the KNN solid solution matrix.Furthermore,the piezoelectric scaffold released zinc ions,and electrical stimulation driven by ultrasound resulted in significant antibacterial effects through direct and immunoregulatory antibacterial pathways.Mechanistic investigation suggested that extracellular matrix ligands and complement and coagulation cascades may have a moderate effect on macrophage phagocytosis.This work highlights potential application methods for fabricating novel antibacterial hybrid piezoelectric scaffolds and engineering macrophages with immunoregu-latory antibacterial activity.
基金Supported by the National Natural Science Foundation of China(42375018 and U2142203)Key Innovation Team of China Meteorological Administration(CMA2022ZD07)Youth Research Project of China Meteorological Administration Training Centre(2023CMATCQN03)。
文摘Supercells are the most severe and long-lasting type of highly organized convective storms,with the greatest potential for producing extreme weather events and causing significant disasters.This article provides a comprehensive overview and recent highlights of supercell research,including the unique structure,environmental characteristics,and the formation and maintenance mechanisms of the mesocyclone.Buoyancy instability is a necessary ingredient in the supercell’s environment,whereas dynamic factors such as vertical wind shear and low-level storm relative helicity are more sensitive parameters for distinguishing supercells from non-supercells.The near-storm environmental parameters derived from multi-sensor observations are expected to enhance high-resolution nowcasting of supercell storms.Different types of supercells,including those producing distinct hazardous weather,exhibit unique reflectivity morphology and dynamical/microphysical structures,e.g.,tornadic supercells have a strong low-level mesocyclone while severe hail supercells feature a strong and deep mesocyclone.Mesocyclones associated with damaging winds are accompanied by significant mid-level radial convergence,while those responsible for heavy precipitation are typically located at low levels.The vertical vorticity of the mesocyclone is generated through the tilting of environmental horizontal vorticity by storm-related intense updrafts.The horizontal vorticity that tilts into the mid-level mesocyclone originates from the environmental vertical wind shear,which produces the horizontal vorticity along the inflow to the storms.In contrast,the horizontal vorticity contributing to the low-level mesocyclone derives from two distinct mechanisms,i.e.,environmental vertical shear in the boundary layer and gust front-induced baroclinicity.It remains unclear which mechanism is more dominant.Moreover,the maintenance and enhancement mechanisms of mesocyclones are complex and vary across different scenarios,particularly when embedded within heavy precipitation,during storm mergers,or in proximity to surface mesoscale boundaries(e.g.,fronts,drylines,gust fronts,and their associated convergence lines).In recent years,based on super high-resolution numerical experiment results,the physical conceptual models of the supercell tornadogenesis have been updated.The newly revealed microphysical and dynamic characteristics from polarimetric Doppler radar observations enable more accurate hail size detection.However,the refined physical conceptual model of severe hail growth still requires improvement,and our understanding of the formation mechanisms behind extreme wind gusts and flash floods associated with supercells remains limited.
基金supported by the National Natural Science Foundation of China(82271866,82471853 and 82402127)the Guangzhou Key Research and Development Program(02A004999000186)the Guangdong Basic and Applied Basic Research Foundation(2024B1515020039,2021A1515011451,2017B030314120 and 202201011028).
文摘T follicular helper(Tfh)cells specialize in facilitating germinal center B-cell activation and high-affinity antibody generation,which are crucial in humoral immune responses.However,aberrant control of Tfh cells also contributes to the generation of self-reactive autoantibodies and promotes autoimmune diseases such as systemic lupus erythematosus(SLE).The mechanisms that control proper Tfh expansion remain unclear.Here,we show that farnesoid X receptor(FXR)is relatively upregulated in Tfh cells.Genetic deletion of Fxr restrains Tfh expansion both at steady state and in pristane-induced lupus.As a consequence of these defects,mice lacking Fxr manifested GC dysfunction and decreased plasma cell and autoantibody production,which alleviated nephritis progression in pristane-induced lupus.Mechanistically,FXR intrinsically regulates cholesterol homeostasis in Tfh cells,which subsequently controls Tfh cell proliferation.Preclinical treatment of wild-type(WT)mice with the clinically approved drug ursodeoxycholic acid(UDCA)to reduce FXR signaling mitigated lupus disease progression by repressing Tfh expansion,the GC reaction and autoantibody production.These findings provide a rationale for exploring FXR as a potential therapeutic target for SLE.
基金supported by the National Natural Science Foundation of China(42375014,42175008)Basic Research Fund of CAMS(2023Z020)and Open Grants of the State Key Laboratory of Severe Weather(2024LASW-A03).
文摘The intensity changes of tropical cyclones(TCs)are a key focus in TC research community and pose significant challenges for operational forecasting.Water vapor plays a crucial role in the variations of TC intensity.This paper reviews and summarizes representative findings regarding the influence of water vapor on TC intensity.The discussion primarily covers the impact of water vapor sources,transport,distribution,budget,and phase changes on TC intensity.However,critical scientific challenges remain,including establishing quantitative thresholds for dry and cold air intrusion,understanding microphysical and dynamic interaction mechanisms in high-resolution models,and developing advanced moist thermodynamic approaches.Addressing these challenges is essential for advancing research and improving forecasts of the impact of water vapor on TC intensity.
