The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous comp...The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous composite(Ru/HfO_(2)-NC)with Ru/HfO2nanoparticles nested in nitrogen-doped porous carbon via a zeolitic imidazole frameworks-assisted(ZIF)co-precipitation and calcination approach.In particular,ZIF guides an in-situ construction of nested configuration and confines the scattered nanoparticles.Strikingly,Ru/HfO_(2)-NC exhibits unusual ORR activity,superb durability,and methanol tolerance in0.1 M KOH solution with high half-wave potential(E1/2)of 0.83 V and follows a near-4e-reaction pathway.Additionally,the ZAB assembled with cathodic Ru/HfO_(2)-NC outputs a power density of 157.3 m W cm^(-2),a specific capacity of 775 mA h g-1Zn,and a prolonged lifespan of 258 h at 5 mA cm^(-2).Meanwhile,the catalyst has demonstrated potential applicability in flexible ZAB.As suggested by experimental results and density functional theory(DFT)analysis,the remarkable property possibly originated from the optimization of the adsorption and desorption of reactive intermediates caused by the reconfiguration of the electronic structure between Ru and HfO_(2).展开更多
Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognize...Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognized by lipase/co-lipase enzyme complex, result-ing in rapid release and precipitation of encapsulated drugs. The precipitates are then cap-tured and removed by intestinal mucus, reducing the delivery efficacy of SNEs. Herein, theamphiphilic polymer Pluronic? F127 was incorporated into long and short-chain triglyc-erides(LCT, SCT) based SNEs to diminish the recognition and therefore minimized theirdegradation by enzymes and clearance by mucus. The SNEs were characterized in termsof particle size, zeta potential and stability. Ex vivo multiple particles tracking studies wereperformed by adding particle solution into fresh rat mucus. Cellular uptake of SNEs wereconducted by using E12 cells, the absorption and distribution in small intestine were alsostudied after oral administration in male Sprague-Dawley(SD) rats. The in vitro digestionrate of SNEs were found to be in following order SCT-SNE > SCT-F127-SNE > LCT-SNE > LCT-F127-SNE. Moreover, the LCT-F127-SNE was found to be most effective in enhancing cellularuptake, resulting in 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE andSCT-F127-SNE, respectively. After incubating the SNE with E12 cells, the LCT-F127-SNE ex-hibited the highest amount regarding both mucus penetration and cellular uptake, with anuptake amount number(via bicinchoninic acid(BCA) analysis) of 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. The in vivo results revealed that orally administered LCT-F127-SNE could significantly increase the bioavailability of Cyclosporine A(CsA), which was approximately 2.43-fold, 1.33-fold and 1.80-fold higher than that of SCT-SNE, SCT-F127-SNE and LCT-SNE, respectively. We address in this work that F127-modified SNEs have potentials to improve oral drug absorption by significantly reducing gastrointestinal enzymatic degradation and simultaneously enhancing mucus penetration.展开更多
Water is the fundamental natural resource that supports life,ecosystems and human society.Thus studying the water cycle is important for sustainable development.In the context of global climate change,a better under-s...Water is the fundamental natural resource that supports life,ecosystems and human society.Thus studying the water cycle is important for sustainable development.In the context of global climate change,a better under-standing of the water cycle is needed.This study summarises current research and highlights future directions of water science from four perspectives:(i)the water cycle;(ii)hydrologic processes;(iii)coupled natural-social water systems;and(iv)integrated watershed management.Emphasis should be placed on understanding the joint impacts of climate change and human activities on hydrological processes and water resources across temporal and spatial scales.Understanding the interactions between land and atmosphere are keys to addressing this is-sue.Furthermore systematic approaches should be developed for large basin studies.Areas for focused research include:variations of cryosphere hydrological processes in upper alpine zones;and human activities on the wa-ter cycle and relevant biogeochemical processes in middle-lower reaches.Because the water cycle is naturally coupled with social characteristics across multiple scales,multi-process and multi-scale models are needed.Hy-drological studies should use this new paradigm as part of water-food-energy frontier research.This will help to promote interdisciplinary study across natural and social sciences in accordance with the United Nation’s sustainable development goals.展开更多
The techniques for oceanographic observation have made great progress in both space-time coverage and quality, which make the observation data present some characteristics of big data. We explore the essence of global...The techniques for oceanographic observation have made great progress in both space-time coverage and quality, which make the observation data present some characteristics of big data. We explore the essence of global ocean dynamic via constructing a complex network with regard to sea surface temperature. The global ocean is divided into discrete regions to represent the nodes of the network. To understand the ocean dynamic behavior, we introduce the Gaussian mixture models to describe the nodes as limit-cycle oscillators. The interacting dynamical oscillators form the complex network that simulates the ocean as a stochastic system. Gaussian probability matching is suggested to measure the behavior similarity of regions. Complex network statistical characteristics of the network are analyzed in terms of degree distribution, clustering coefficient and betweenness. Experimental results show a pronounced sensitivity of network characteristics to the climatic anomaly in the oceanic circulation. Particularly, the betweenness reveals the main pathways to transfer thermal energy of El Niño–Southern oscillation. Our works provide new insights into the physical processes of ocean dynamic, as well as climate changes and ocean anomalies.展开更多
Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolys...Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolysis approach to obtain highly dispersed Ru nanoparticles immobilized on the vacancy-rich Ni-NiO@C hollow microsphere(Ru/Ni-NiO@C).Fine annealing at 400°C introduces nickel and oxygen vacancies on Ru/Ni-NiO@C surface,resulting in an improved electrical conductivity and rapid mass-charge transfer efficiency.Ru/Ni-NiO@C with a hollow micro/nanostructure and interconnected meso-porosity favors the maximal exposure of abundant active sites and elevation of hydrogen oxidation reaction(HOR)activity.Experimental results and density functional theory(DFT)calculations reveal that an electronic effect between Ru and Ni-NiO@C,in conjunction with nickel/oxygen vacancies in the NiO species could synergistically optimize hydrogen binding energy(HBE)and hydroxide binding energy(OHBE).The HBE and OHBE optimizations thus created confer Ru/Ni-NiO@C with a mass activity over 7.75 times higher than commercial Pt/C.Our work may provide a constructive route to make a breakthrough in elevating the hydrogen electrocatalytic performance.展开更多
Graphene is the thinest nanomaterial known in the world,which has unique electronic mobility,super specific surface area,high mechanical strength,excellent corrosion resistance and surface chemical structure.Due to it...Graphene is the thinest nanomaterial known in the world,which has unique electronic mobility,super specific surface area,high mechanical strength,excellent corrosion resistance and surface chemical structure.Due to its special nanostructure and excellent physical and chemical properties,graphene has a broad application prospect in the fields of electronics,optics,magnetism,biomedicine,catalysis,energy storage and sensors.In order to better develop and utilize graphene data,this paper reviewed the structural characteristics of graphene,as well as its research progress in biosensors,bio-imaging,aerogel and other biomedical fields,hoping to provide scientific basis for better development of graphene and the development of graphene pharmaceutical products.展开更多
The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive an...The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive and continuous vegetation greening and no weakened land carbon sink in the maturation phase of the 2015/2016 El Niño event over the NH(mainly in the extra-tropics),based on multiple evidences from remote sensing observations,global ecosystem model simulations and atmospheric CO_(2)inversions.We discovered a significant compensation effect of the enhanced vegetation growth in spring on subsequent summer/autumn vegetation growth that sustained vegetation greening and led to a slight increase in the land carbon sink over the spring and summer of 2015(average increases of 23.34%and 0.63%in net ecosystem exchange from two independent datasets relative to a 5-years average before the El Niño event,respectively)and spring of 2016(6.82%),especially in the extra-tropics of the NH,where the water supply during the pre-growing-season(November of the previous year to March of the current year)had a positive anomaly.This seasonal compensation effect was much stronger than that in 1997 and 1998 and significantly alleviated the adverse impacts of the 2015/2016 El Niño event on vegetation growth during its maturation phase.The legacy effect of water supply during the pre-growing-season on subsequent vegetation growth lasted up to approximately six months.Our findings highlight the role of seasonal compensation effects on mediating the land carbon sink in response to episodic extreme El Niño events.展开更多
Application of transition metal boride(TMB) catalysts towards hydrolysis of NaBH_(4) holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework(MOF) a...Application of transition metal boride(TMB) catalysts towards hydrolysis of NaBH_(4) holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework(MOF) assisted strategy to prepare Co_(2)B-CoPO_x with massive boron vacancies by introducing phytic acid(PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous(P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H_(2)O molecules. The vacancy-rich Co_(2)B-CoPO_x catalyst exhibits scalable performance, characterized by a high hydrogen generation rate(HGR) of 7716.7 m L min^(-1)g^(-1) and a low activation energy(Ea) of 44.9 k J/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.展开更多
Genomic structural variations affected widely gene function and morphological traits in plants.Chromosomal inversions(INVs),as an important form of structural variation,can be large and extend to megabases in length[1...Genomic structural variations affected widely gene function and morphological traits in plants.Chromosomal inversions(INVs),as an important form of structural variation,can be large and extend to megabases in length[1],and form the genetic basis of local adaptation and ecotypic differentiation in sunflowers[2],Boechera stricta[3],monkeyflowers[4],mimetic butterflies[5]and ruffs[6],sex determination in nine-spined stickleback[7]and cancer and neurodevelopmental disease in human[8].At present,structural variants,and in particular,INVs,remain largely uncharacterized in plants despite their importance for local adaptation in a variety of species[1],with only a few studies exploring INVs polymorphisms at the population level.Hence,it remains unclear whether adaptive INVs can directly shape the genetic basis for diverse phenotypes in plants,especially in domesticated crops.展开更多
The past decade has witnessed a rapid evolution in identifying more versatile clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)nucleases and their functional variants,as ...The past decade has witnessed a rapid evolution in identifying more versatile clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)nucleases and their functional variants,as well as in developing precise CRISPR/Cas-derived genome editors.The programmable and robust features of the genome editors provide an effective RNAguided platform for fundamental life science research and subsequent applications in diverse scenarios,including biomedical innovation and targeted crop improvement.One of the most essential principles is to guide alterations in genomic sequences or genes in the intended manner without undesired off-target impacts,which strongly depends on the efficiency and specificity of single guide RNA(sgRNA)-directed recognition of targeted DNA sequences.Recent advances in empirical scoring algorithms and machine learning models have facilitated sgRNA design and off-target prediction.In this review,we first briefly introduce the different features of CRISPR/Cas tools that should be taken into consideration to achieve specific purposes.Secondly,we focus on the computer-assisted tools and resources that are widely used in designing sgRNAs and analyzing CRISPR/Cas-induced on-and off-target mutations.Thirdly,we provide insights into the limitations of available computational tools that would help researchers of this field for further optimization.Lastly,we suggest a simple but effective workflow for choosing and applying web-based resources and tools for CRISPR/Cas genome editing.展开更多
Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and ...Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.展开更多
Forest stand structure is not only a crucial factor for regulating forest functioning but also an important indicator for sustainable forest management and ecosystem services.Although there exists a few national/globa...Forest stand structure is not only a crucial factor for regulating forest functioning but also an important indicator for sustainable forest management and ecosystem services.Although there exists a few national/global structure databases for natural forests,a country-wide synthetic structure database for plantation forests over China,the world’s largest player in plantation forests,has not been achieved.In this study,we built a country-wide synthetic stand structure database by surveying more than 600 peer-reviewed literature.The database covers tree species,mean stand age,mean tree height,stand density,canopy coverage,diameter at breast height,as well as the associated ancillary in-situ topographical and soil properties.A total of 594 pub-lished studies concerning diverse forest stand structure parameters were compiled for 46 tree species.This first synthesis for stand structure of plantation forests over China supports studies on the evolution/health of plantation forests in response to rapid climate change and intensified disturbances,and benefits country-wide sustainable forest management,future afforestation or reforestation planning.Potential users include those studying forest community dynamics,regional tree growth,ecosystem stability,and health,as well as those working with conservation and sustainable management.This dataset is freely acces-sible at http://www.doi.org/10.11922/sciencedb.j00076.00091.展开更多
Landslides cause huge human and economic losses globally.Detecting landslide precursors is crucial for disaster prevention.The small baseline subset interferometric synthetic-aperture radar(SBAS-InSAR)has been a popul...Landslides cause huge human and economic losses globally.Detecting landslide precursors is crucial for disaster prevention.The small baseline subset interferometric synthetic-aperture radar(SBAS-InSAR)has been a popular method for detecting landslide precursors.However,non-monotonic displacements in SBAS-InSAR results are pervasive,making it challenging to single out true landslide signals.By exploiting time series displacements derived by SBAS-InSAR,we proposed a method to identify moving landslides.The method calculates two indices(global/local change index)to rank monotonicity of the time series from the derived displacements.Using two thresholds of the proposed indices,more than 96%of background noises in displacement results can be removed.We also found that landslides on the east and west slopes are easier to detect than other slope aspects for the Sentinel-1 images.By repressing background noises,this method can serve as a convenient tool to detect landslide precursors in mountainous areas.展开更多
Many works on topological insulators have focused on periodic lattice systems,where short-and long-range order is considered.Here we construct a two-dimensional amorphous photonic crystal with short-range order and a ...Many works on topological insulators have focused on periodic lattice systems,where short-and long-range order is considered.Here we construct a two-dimensional amorphous photonic crystal with short-range order and a controllable level of long-range order and experimentally investigate the transport of topological edge states in this amorphous system.We demonstrate that topology properties remain constant with unidirectional edge state propagation,immune to specific disorder strength.The partition phenomena of edge states are also observed at the intersection of four topological channels in microwave experiments.This proposed amorphous configuration provides new opportunities to explore the relationship between short-range order and topology and may alleviate the fabrication difficulties of topological optical devices for practical applications.展开更多
Topological edge states have an important role in optical modulation with potential applications in wavelength division multiplexers(WDMs).In this paper,2D photonic crystals(PCs)with different rotation angles are comb...Topological edge states have an important role in optical modulation with potential applications in wavelength division multiplexers(WDMs).In this paper,2D photonic crystals(PCs)with different rotation angles are combined to generate topological edge states.We reveal the relationship between the edge states and the rotation parameters of PCs,and further propose a WDM to realize the application of adjustable beams.Our findings successfully reveal the channel selectivity for optical transmission and provide a flexible way to promote the development of topological photonic devices.展开更多
Background:Migraine and epilepsy are both episodic disorders,with some overlapping symptoms,mechanisms and therapies.Clinically,there is a comorbid relationship between them.Some migraine patients may exhibit epilepti...Background:Migraine and epilepsy are both episodic disorders,with some overlapping symptoms,mechanisms and therapies.Clinically,there is a comorbid relationship between them.Some migraine patients may exhibit epileptic discharges by electroencephalogram(EEG)recording.Therefore,the two conditions are easily misdiagnosed.Case presentation:We reported a 16-year-old female patient who was admitted to our hospital due to repeated headaches with disturbance of consciousness.Epileptic discharge was recorded by long-term EEG.The patient had been misdiagnosed as epilepsy,and had no response to anti-seizure medicines(ASMs).We revised her diagnosis and prescribed ibuprofen in her acute episode and prophylactic medicine,including funarizine and amitriptyline in her interictal period.One week later,her headache disappeared.Conclusions:This patient manifested with altered levels of consciousness during headache episodes,and the abnormal EEG results lead to the misdiagnosis as epilepsy.Clinicians should be cautious to the distinction between migraine and epilepsy.展开更多
基金supported by the National Natural Science Foundation of China(21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001)+1 种基金the Project of HighLevel Talents of Guangxi(F-KA18015)Guangxi Technology Base and Talent Subject(GUIKE AD18126001,GUIKE AD20297039)。
文摘The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous composite(Ru/HfO_(2)-NC)with Ru/HfO2nanoparticles nested in nitrogen-doped porous carbon via a zeolitic imidazole frameworks-assisted(ZIF)co-precipitation and calcination approach.In particular,ZIF guides an in-situ construction of nested configuration and confines the scattered nanoparticles.Strikingly,Ru/HfO_(2)-NC exhibits unusual ORR activity,superb durability,and methanol tolerance in0.1 M KOH solution with high half-wave potential(E1/2)of 0.83 V and follows a near-4e-reaction pathway.Additionally,the ZAB assembled with cathodic Ru/HfO_(2)-NC outputs a power density of 157.3 m W cm^(-2),a specific capacity of 775 mA h g-1Zn,and a prolonged lifespan of 258 h at 5 mA cm^(-2).Meanwhile,the catalyst has demonstrated potential applicability in flexible ZAB.As suggested by experimental results and density functional theory(DFT)analysis,the remarkable property possibly originated from the optimization of the adsorption and desorption of reactive intermediates caused by the reconfiguration of the electronic structure between Ru and HfO_(2).
基金financial support received from the National Natural Science Foundation of China(81373356,81573378 and 81703436)the Science and Technology Innovation Action Plan for Basic Research of Shanghai 2014 (14JC1493200)CASIMM0120153020,Shanghai Sailing Program 2017(17YF1423500)
文摘Self-nanoemulsifying systems(SNEs) have excellent ability to improve the solubility ofpoorly water-soluble drugs(PWSD). However, SNEs are likely to be degraded in gastroin-testinal(GIT) when their surface is recognized by lipase/co-lipase enzyme complex, result-ing in rapid release and precipitation of encapsulated drugs. The precipitates are then cap-tured and removed by intestinal mucus, reducing the delivery efficacy of SNEs. Herein, theamphiphilic polymer Pluronic? F127 was incorporated into long and short-chain triglyc-erides(LCT, SCT) based SNEs to diminish the recognition and therefore minimized theirdegradation by enzymes and clearance by mucus. The SNEs were characterized in termsof particle size, zeta potential and stability. Ex vivo multiple particles tracking studies wereperformed by adding particle solution into fresh rat mucus. Cellular uptake of SNEs wereconducted by using E12 cells, the absorption and distribution in small intestine were alsostudied after oral administration in male Sprague-Dawley(SD) rats. The in vitro digestionrate of SNEs were found to be in following order SCT-SNE > SCT-F127-SNE > LCT-SNE > LCT-F127-SNE. Moreover, the LCT-F127-SNE was found to be most effective in enhancing cellularuptake, resulting in 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE andSCT-F127-SNE, respectively. After incubating the SNE with E12 cells, the LCT-F127-SNE ex-hibited the highest amount regarding both mucus penetration and cellular uptake, with anuptake amount number(via bicinchoninic acid(BCA) analysis) of 3.5-fold, 2.1-fold and 1.7-fold higher than that of SCT-SNE, LCT-SNE and SCT-F127-SNE, respectively. The in vivo results revealed that orally administered LCT-F127-SNE could significantly increase the bioavailability of Cyclosporine A(CsA), which was approximately 2.43-fold, 1.33-fold and 1.80-fold higher than that of SCT-SNE, SCT-F127-SNE and LCT-SNE, respectively. We address in this work that F127-modified SNEs have potentials to improve oral drug absorption by significantly reducing gastrointestinal enzymatic degradation and simultaneously enhancing mucus penetration.
基金This work was supported by the National Natural Science Founda-tion of China(Grant No.L1924041)the Research Project on the Discipline Development Strategy of Academic Divisions of the Chinese Academy of Sciences(Grant No.XK2019DXC006).
文摘Water is the fundamental natural resource that supports life,ecosystems and human society.Thus studying the water cycle is important for sustainable development.In the context of global climate change,a better under-standing of the water cycle is needed.This study summarises current research and highlights future directions of water science from four perspectives:(i)the water cycle;(ii)hydrologic processes;(iii)coupled natural-social water systems;and(iv)integrated watershed management.Emphasis should be placed on understanding the joint impacts of climate change and human activities on hydrological processes and water resources across temporal and spatial scales.Understanding the interactions between land and atmosphere are keys to addressing this is-sue.Furthermore systematic approaches should be developed for large basin studies.Areas for focused research include:variations of cryosphere hydrological processes in upper alpine zones;and human activities on the wa-ter cycle and relevant biogeochemical processes in middle-lower reaches.Because the water cycle is naturally coupled with social characteristics across multiple scales,multi-process and multi-scale models are needed.Hy-drological studies should use this new paradigm as part of water-food-energy frontier research.This will help to promote interdisciplinary study across natural and social sciences in accordance with the United Nation’s sustainable development goals.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1706218,61971388,and L1824025).
文摘The techniques for oceanographic observation have made great progress in both space-time coverage and quality, which make the observation data present some characteristics of big data. We explore the essence of global ocean dynamic via constructing a complex network with regard to sea surface temperature. The global ocean is divided into discrete regions to represent the nodes of the network. To understand the ocean dynamic behavior, we introduce the Gaussian mixture models to describe the nodes as limit-cycle oscillators. The interacting dynamical oscillators form the complex network that simulates the ocean as a stochastic system. Gaussian probability matching is suggested to measure the behavior similarity of regions. Complex network statistical characteristics of the network are analyzed in terms of degree distribution, clustering coefficient and betweenness. Experimental results show a pronounced sensitivity of network characteristics to the climatic anomaly in the oceanic circulation. Particularly, the betweenness reveals the main pathways to transfer thermal energy of El Niño–Southern oscillation. Our works provide new insights into the physical processes of ocean dynamic, as well as climate changes and ocean anomalies.
基金supported by the National Natural Science Foundation of China(21965005)the Natural Science Foundation of Guangxi Province(2018GXNSFAA294077,2021GXNSFAA076001)+1 种基金the Project of High-Level Talents of Guangxi(F-KA18015)the Guangxi Technology Base and Talent Subject(GUIKEAD18126001,GUIKE AD20297039)。
文摘Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolysis approach to obtain highly dispersed Ru nanoparticles immobilized on the vacancy-rich Ni-NiO@C hollow microsphere(Ru/Ni-NiO@C).Fine annealing at 400°C introduces nickel and oxygen vacancies on Ru/Ni-NiO@C surface,resulting in an improved electrical conductivity and rapid mass-charge transfer efficiency.Ru/Ni-NiO@C with a hollow micro/nanostructure and interconnected meso-porosity favors the maximal exposure of abundant active sites and elevation of hydrogen oxidation reaction(HOR)activity.Experimental results and density functional theory(DFT)calculations reveal that an electronic effect between Ru and Ni-NiO@C,in conjunction with nickel/oxygen vacancies in the NiO species could synergistically optimize hydrogen binding energy(HBE)and hydroxide binding energy(OHBE).The HBE and OHBE optimizations thus created confer Ru/Ni-NiO@C with a mass activity over 7.75 times higher than commercial Pt/C.Our work may provide a constructive route to make a breakthrough in elevating the hydrogen electrocatalytic performance.
基金Supported by Qihuang Engineering High-Level Talent Team Cultivation Project of Guangxi University of Chinese Medicine(2018002)Guangxi Science and Technology Major Project(GK AA17292008)。
文摘Graphene is the thinest nanomaterial known in the world,which has unique electronic mobility,super specific surface area,high mechanical strength,excellent corrosion resistance and surface chemical structure.Due to its special nanostructure and excellent physical and chemical properties,graphene has a broad application prospect in the fields of electronics,optics,magnetism,biomedicine,catalysis,energy storage and sensors.In order to better develop and utilize graphene data,this paper reviewed the structural characteristics of graphene,as well as its research progress in biosensors,bio-imaging,aerogel and other biomedical fields,hoping to provide scientific basis for better development of graphene and the development of graphene pharmaceutical products.
基金This study was financially supported by the National Key Research and Development Program of China(Grant No.2022YFF0801802)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0306)+2 种基金the National Natural Science Foundation of China(Grant No.42171050)the China Postdoctoral Science Foundation(Grant No.2023M730281)the State Key Laboratory of Earth Surface Processes and Resource Ecology of Beijing Normal University(Grant No.2023-KF-07).
文摘The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive and continuous vegetation greening and no weakened land carbon sink in the maturation phase of the 2015/2016 El Niño event over the NH(mainly in the extra-tropics),based on multiple evidences from remote sensing observations,global ecosystem model simulations and atmospheric CO_(2)inversions.We discovered a significant compensation effect of the enhanced vegetation growth in spring on subsequent summer/autumn vegetation growth that sustained vegetation greening and led to a slight increase in the land carbon sink over the spring and summer of 2015(average increases of 23.34%and 0.63%in net ecosystem exchange from two independent datasets relative to a 5-years average before the El Niño event,respectively)and spring of 2016(6.82%),especially in the extra-tropics of the NH,where the water supply during the pre-growing-season(November of the previous year to March of the current year)had a positive anomaly.This seasonal compensation effect was much stronger than that in 1997 and 1998 and significantly alleviated the adverse impacts of the 2015/2016 El Niño event on vegetation growth during its maturation phase.The legacy effect of water supply during the pre-growing-season on subsequent vegetation growth lasted up to approximately six months.Our findings highlight the role of seasonal compensation effects on mediating the land carbon sink in response to episodic extreme El Niño events.
基金supported by the National Natural Science Foundation of China (No.21965005)Natural Science Foundation of Guangxi Province (No.2021GXNSFAA076001)+1 种基金Guangxi Technology Base and Talent Subject (Nos.GUIKE AD18126001, GUIKE AD20297039)Innovation Project of Guangxi Graduate Education (Nos.YCSW2023140, YCBZ2023062)。
文摘Application of transition metal boride(TMB) catalysts towards hydrolysis of NaBH_(4) holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework(MOF) assisted strategy to prepare Co_(2)B-CoPO_x with massive boron vacancies by introducing phytic acid(PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous(P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H_(2)O molecules. The vacancy-rich Co_(2)B-CoPO_x catalyst exhibits scalable performance, characterized by a high hydrogen generation rate(HGR) of 7716.7 m L min^(-1)g^(-1) and a low activation energy(Ea) of 44.9 k J/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.
基金supported by the National Natural Science Foundation of China(32188102 and 32372148)the National Key R&D Program of China(2022YFE0139400)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2023B1515020053)the Youth Innovation of Chinese Academy of Agricultural Sciences(Y20230C36).
文摘Genomic structural variations affected widely gene function and morphological traits in plants.Chromosomal inversions(INVs),as an important form of structural variation,can be large and extend to megabases in length[1],and form the genetic basis of local adaptation and ecotypic differentiation in sunflowers[2],Boechera stricta[3],monkeyflowers[4],mimetic butterflies[5]and ruffs[6],sex determination in nine-spined stickleback[7]and cancer and neurodevelopmental disease in human[8].At present,structural variants,and in particular,INVs,remain largely uncharacterized in plants despite their importance for local adaptation in a variety of species[1],with only a few studies exploring INVs polymorphisms at the population level.Hence,it remains unclear whether adaptive INVs can directly shape the genetic basis for diverse phenotypes in plants,especially in domesticated crops.
基金the National Natural Science Foundation of China(42041004 and 52209027)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100103)+3 种基金the support from the China Postdoctoral Science Foundation(2022M711857)the Postdoctoral Innovation Talents Support Program of China(BX2021166)the Shuimu Tsinghua Scholar Programthe financial support from the National Natural Science Foundation of China(42071029)。
基金We greatly appreciate Dr.Jeffrey McKinnon for his thoughtful proofreading and wonderful suggestion on this manuscript.We also greatly appreciate the scientific community for making huge progress in this field.We have tried to cite as many references as possible.However,due to the page limitation,there may be some important works not cited herewe apologize for this.The work in Dr.Baohong Zhang’s Laboratory is supported in part by Cotton Incorporated and the National Science Foundation,the United States(Grant No.1658709)+2 种基金This work was also supported by the National Natural Science Foundation of China(Grant No.31700316)the Fundamental Research Funds for the Central Nonprofit Scientific Institution(Grant No.1610172018009)the Natural Science Foundation of Hubei Province,China(Grant No.2018CFB543).
文摘The past decade has witnessed a rapid evolution in identifying more versatile clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)nucleases and their functional variants,as well as in developing precise CRISPR/Cas-derived genome editors.The programmable and robust features of the genome editors provide an effective RNAguided platform for fundamental life science research and subsequent applications in diverse scenarios,including biomedical innovation and targeted crop improvement.One of the most essential principles is to guide alterations in genomic sequences or genes in the intended manner without undesired off-target impacts,which strongly depends on the efficiency and specificity of single guide RNA(sgRNA)-directed recognition of targeted DNA sequences.Recent advances in empirical scoring algorithms and machine learning models have facilitated sgRNA design and off-target prediction.In this review,we first briefly introduce the different features of CRISPR/Cas tools that should be taken into consideration to achieve specific purposes.Secondly,we focus on the computer-assisted tools and resources that are widely used in designing sgRNAs and analyzing CRISPR/Cas-induced on-and off-target mutations.Thirdly,we provide insights into the limitations of available computational tools that would help researchers of this field for further optimization.Lastly,we suggest a simple but effective workflow for choosing and applying web-based resources and tools for CRISPR/Cas genome editing.
基金the financial support by the Fundamental Research Funds for the Central Universities(No.2412019FZ008)the National Natural Science Foundation of China(Nos.22131004 and U21A20330)the"111 Project(No.B18012)。
文摘Benzimidazoles are very important chemical materials in the pharmaceutical industry,and the most common synthetic route is cyclization of o-phenylenediamine with carbon sources,in which utilization of inexpensive and abundant CO_(2)as C1 source is very impressive.Porous aromatic frameworks(PAFs)with highly desired skeletons have attracted great attentions in gas capture and catalysis.Herein,B-based PAF-165 and PAF-166 are designed and synthesized via Friedel-Crafts alkylation reaction,which present high surface areas as well as high stability.Benefiting from the abundant electron-deficient B centers,both PAFs exhibit excellent selective CO_(2)adsorption abilities.The presence of sterically hindered B units in PAFs can act as Lewis acid active sites for the frustrated Lewis pairs(FLPs)in situ formation with ophenylenediamine,thus promoting the synthesis of benzimidazole.The optimal reaction conditions for o-phenylenediamine cyclization with PAF catalysts are explored,and the reaction mechanism is also proposed.This work provides feasible ideas for incorporating FLPs within porous materials as reusable heterogeneous catalysts for CO_(2)capture and conversion.
基金This project was financially supported by the National Natural Science Foundation of China[No.41922001,41530747]the National Key Research and Development Program of China[No.2016YFD060020603]the Swedish Formas.
文摘Forest stand structure is not only a crucial factor for regulating forest functioning but also an important indicator for sustainable forest management and ecosystem services.Although there exists a few national/global structure databases for natural forests,a country-wide synthetic structure database for plantation forests over China,the world’s largest player in plantation forests,has not been achieved.In this study,we built a country-wide synthetic stand structure database by surveying more than 600 peer-reviewed literature.The database covers tree species,mean stand age,mean tree height,stand density,canopy coverage,diameter at breast height,as well as the associated ancillary in-situ topographical and soil properties.A total of 594 pub-lished studies concerning diverse forest stand structure parameters were compiled for 46 tree species.This first synthesis for stand structure of plantation forests over China supports studies on the evolution/health of plantation forests in response to rapid climate change and intensified disturbances,and benefits country-wide sustainable forest management,future afforestation or reforestation planning.Potential users include those studying forest community dynamics,regional tree growth,ecosystem stability,and health,as well as those working with conservation and sustainable management.This dataset is freely acces-sible at http://www.doi.org/10.11922/sciencedb.j00076.00091.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0906)。
文摘Landslides cause huge human and economic losses globally.Detecting landslide precursors is crucial for disaster prevention.The small baseline subset interferometric synthetic-aperture radar(SBAS-InSAR)has been a popular method for detecting landslide precursors.However,non-monotonic displacements in SBAS-InSAR results are pervasive,making it challenging to single out true landslide signals.By exploiting time series displacements derived by SBAS-InSAR,we proposed a method to identify moving landslides.The method calculates two indices(global/local change index)to rank monotonicity of the time series from the derived displacements.Using two thresholds of the proposed indices,more than 96%of background noises in displacement results can be removed.We also found that landslides on the east and west slopes are easier to detect than other slope aspects for the Sentinel-1 images.By repressing background noises,this method can serve as a convenient tool to detect landslide precursors in mountainous areas.
基金supported by the Key Academic Discipline Project of China University of Mining and Technology(Grant No.2022WLXK06)the National Natural Science Foundation of China(Grant Nos.11874274,12004425,and 12274315)+3 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20200630)the Qing Lan Projecta Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Basic Research Program of Xuzhou(Grant No.KC22016)。
文摘Many works on topological insulators have focused on periodic lattice systems,where short-and long-range order is considered.Here we construct a two-dimensional amorphous photonic crystal with short-range order and a controllable level of long-range order and experimentally investigate the transport of topological edge states in this amorphous system.We demonstrate that topology properties remain constant with unidirectional edge state propagation,immune to specific disorder strength.The partition phenomena of edge states are also observed at the intersection of four topological channels in microwave experiments.This proposed amorphous configuration provides new opportunities to explore the relationship between short-range order and topology and may alleviate the fabrication difficulties of topological optical devices for practical applications.
基金National Key Research and Development Program of China(2022YFE0122300)National Natural Science Foundation of China(11811530052,12004425,1211101294,62105126)+2 种基金State Key Laboratory of Millimeter Waves(K202105,K202238)Intergovernmental Science and Technology Regular Meeting Exchange Project of Ministry of Science and Technology of China(CB02-20)Natural Science Foundation of Jiangsu Province(BK20200630)。
文摘Topological edge states have an important role in optical modulation with potential applications in wavelength division multiplexers(WDMs).In this paper,2D photonic crystals(PCs)with different rotation angles are combined to generate topological edge states.We reveal the relationship between the edge states and the rotation parameters of PCs,and further propose a WDM to realize the application of adjustable beams.Our findings successfully reveal the channel selectivity for optical transmission and provide a flexible way to promote the development of topological photonic devices.
基金This report was approved by the Ethics Committee of the Second Afliated Hospital of Chongqing Medical University[2022(698)]and consent was obtained from the patient’s parents.
文摘Background:Migraine and epilepsy are both episodic disorders,with some overlapping symptoms,mechanisms and therapies.Clinically,there is a comorbid relationship between them.Some migraine patients may exhibit epileptic discharges by electroencephalogram(EEG)recording.Therefore,the two conditions are easily misdiagnosed.Case presentation:We reported a 16-year-old female patient who was admitted to our hospital due to repeated headaches with disturbance of consciousness.Epileptic discharge was recorded by long-term EEG.The patient had been misdiagnosed as epilepsy,and had no response to anti-seizure medicines(ASMs).We revised her diagnosis and prescribed ibuprofen in her acute episode and prophylactic medicine,including funarizine and amitriptyline in her interictal period.One week later,her headache disappeared.Conclusions:This patient manifested with altered levels of consciousness during headache episodes,and the abnormal EEG results lead to the misdiagnosis as epilepsy.Clinicians should be cautious to the distinction between migraine and epilepsy.
