Recent studies have suggested that long-term application of anti-angiogenic drugs may impair oral mucosal wound healing.This study investigated the effect of sunitinib on oral mucosal healing impairment in mice and th...Recent studies have suggested that long-term application of anti-angiogenic drugs may impair oral mucosal wound healing.This study investigated the effect of sunitinib on oral mucosal healing impairment in mice and the therapeutic potential of Bifidobacterium breve(B.breve).A mouse hard palate mucosal defect model was used to investigate the influence of sunitinib and/or zoledronate on wound healing.The volume and density of the bone under the mucosal defect were assessed by micro-computed tomography(micro-CT).Inflammatory factors were detected by protein microarray analysis and enzyme-linked immunosorbent assay(ELISA).The senescence and biological functions were tested in oral mucosal stem cells(OMSCs)treated with sunitinib.Ligated loop experiments were used to investigate the effect of oral B.breve.Neutralizing antibody for interleukin-10(IL-10)was used to prove the critical role of IL-10 in the pro-healing process derived from B.breve.Results showed that sunitinib caused oral mucosal wound healing impairment in mice.In vitro,sunitinib induced cellular senescence in OMSCs and affected biological functions such as proliferation,migration,and differentiation.Oral administration of B.breve reduced oral mucosal inflammation and promoted wound healing via intestinal dendritic cells(DCs)-derived IL-10.IL-10 reversed cellular senescence caused by sunitinib in OMSCs,and IL-10 neutralizing antibody blocked the ameliorative effect of B.breve on oral mucosal wound healing under sunitinib treatment conditions.In conclusion,sunitinib induces cellular senescence in OMSCs and causes oral mucosal wound healing impairment and oral administration of B.breve could improve wound healing impairment via intestinal DCs-derived IL-10.展开更多
Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–gly...Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–glycerol system.Longer whiskers were obtained from crystal seeds prepared via hydration of DH for 30 s than via ball milling for 5 min followed by hydration for 20 s.The attachment of cetyltrimethyl ammonium bromide and glycerol additives to the whisker tops promoted whisker growth.The whisker sponges exhibited good thermal barrier properties and compression cycle stability.展开更多
In magnetic topological materials,the interplay between magnetism and nontrivial topology gives rise to exotic quantum transport phenomena,including the anomalous Hall effect and anomalous Nernst effect.Here,we report...In magnetic topological materials,the interplay between magnetism and nontrivial topology gives rise to exotic quantum transport phenomena,including the anomalous Hall effect and anomalous Nernst effect.Here,we report the observation of intrinsic topological Hall and topological Nernst effects below the Néel temperature(T_(N)=25 K)in the antiferromagnetic(AFM)topological insulator Mn Bi_(2)Te_(4).The maximum of topological Hall resistivity reaches approximately 9μΩ·cm at 2 K,while the topological Nernst signal attains a peak value of 0.1μV/K near 10 K.These anomalous transport behaviors originate from the net Berry curvature induced by the non-collinear spin structure in the canted AFM state.Our results suggest a close connection between the topological thermoelectric effect and non-collinear AFM order in AFM topological insulators.展开更多
The well-known Braess paradox in congestion games states that adding an additional road to a transportation network may increase the total travel time, and consequently decrease the overall efficiency. This paper pres...The well-known Braess paradox in congestion games states that adding an additional road to a transportation network may increase the total travel time, and consequently decrease the overall efficiency. This paper presents a paradox in a similar spirit and involves a distributed resource allocation game on networks, namely the power allocation game between countries developed in Li and Morse(2017). The paradox is that by having additional friends may actually decrease a country's total welfare in equilibrium. Conditions for this paradox to occur as well as the price of anarchy results are also derived.展开更多
Based on such severe situation, we need to work out a way that enables us to analyze the current and future ability of a region to provide clean water to meet the needs of its population, and to develop a reasonable s...Based on such severe situation, we need to work out a way that enables us to analyze the current and future ability of a region to provide clean water to meet the needs of its population, and to develop a reasonable strategy to optimize the utilization of water resources in this area. This paper has worked out a resolution model and input the data of China, the United States, Russia, Laos and Afghanistan to do national testing. Then, we use the policy from “diaper incident” to do policy testing. The calculation results of the model are in conformity with the reality. Therefore, the model is effective. At last this model is used to resolve Gansu’s water problem and provide effective advices for the local government.展开更多
Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on py...Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on pyroelectric tactile sensor on the basis of a ferroelectric Bi_(0.5)Na_(0.5)TiO_(3) material to identify different film materials.The fabricated device exhibits different heat absorption capacities while in contact with different materials,leading to a different temperature change in the ferroelectric material under the same illumination.As a result,the device can recognize different materials by comparing the pyroelectric charge via integrating the obtained current under the same irradiation of 365nmlight-emitting diode.The clamped-on pyroelectric tactile sensor can identify six individual materials with a high accuracy of 98.8%and a fast response of 40 ms.All of the above processes can be accomplished with an intelligent material identification system.The device provides a new solution for material identification and lays a foundation for smart factories and laboratories.展开更多
Machine learning techniques have become ubiquitous both in industry and academic applications.Increasing model sizes and training data volumes necessitate fast and efficient distributed training approaches.Collective ...Machine learning techniques have become ubiquitous both in industry and academic applications.Increasing model sizes and training data volumes necessitate fast and efficient distributed training approaches.Collective communications greatly simplify inter-and intra-node data transfer and are an essential part of the distributed training process as information such as gradients must be shared between processing nodes.In this paper,we survey the current state-of-the-art collective communication libraries(namely xCCL,including NCCL,oneCCL,RCCL,MSCCL,ACCL,and Gloo),with a focus on the industry-led ones for deep learning workloads.We investigate the design features of these xCCLs,discuss their use cases in the industry deep learning workloads,compare their performance with industry-made benchmarks(i.e.,NCCL Tests and PARAM),and discuss key take-aways and interesting observations.We believe our survey sheds light on potential research directions of future designs for xCCLs.展开更多
This paper describes the first case of a reductive coupling reaction with indene,a non-heteroatom olefin used as a reducing agent.The scope of the substrate is wide.The homo-coupling,cross-coupling,and synthesis of 12...This paper describes the first case of a reductive coupling reaction with indene,a non-heteroatom olefin used as a reducing agent.The scope of the substrate is wide.The homo-coupling,cross-coupling,and synthesis of 12 and 14-membered rings were realized.The control experiment,indene-product curve and density functional theory calculations showed that the η^(3)-palladium indene intermediate was formed by C-H activation in the presence of cesium carbonate.We speculate that the final product was obtained through a Pd(IV)intermediate or aryl ligand exchange.In addition,we excluded the formation of palladium anion(Pd(0)^(-))intermediates.展开更多
Topological magnetic Weyl semimetals have been proposed to host controllable chiral domain walls which bear a great prospect in device applications. To exploit them in applications, it is important to have a proper wa...Topological magnetic Weyl semimetals have been proposed to host controllable chiral domain walls which bear a great prospect in device applications. To exploit them in applications, it is important to have a proper way to tune and manipulate these domain walls. One possible means is through magnetoelastic coupling. The involvement of rare earth in the lately proposed RAl X(R =rare earth, X = Si and Ge) family magnetic Weyl semimetals may provide such a platform. Here we present the transport and thermodynamic properties of Ce Al Ge under hydrostatic pressure. We find that pressure enhances the antiferromagnetic exchange in Ce Al Ge but essentially retains its magnetic structure. A large topological Hall effect with a pronounced loop shape is observed within the magnetically ordered state, and it splits into two regions under pressure. Such an unusual electromagnetic response is inferred to be a consequence of chiral magnetic domain walls. The unprecedented concomitance of its evolution under pressure and the reentrance of antiferromagnetic order strongly suggest the capability of switching on/off this electromagnetic response in noncentrosymmetric magnetic Weyl semimetals via magnetoelastic coupling.展开更多
High-quality-factor(high-Q-factor)electromagnetic resonance plays an important role in sensor applications.Previously proposed gas refractive index sensors are often limited by the large cavity length or microscale fa...High-quality-factor(high-Q-factor)electromagnetic resonance plays an important role in sensor applications.Previously proposed gas refractive index sensors are often limited by the large cavity length or microscale fabrication process in practical applications.Recently,ultra-high Q factor resonance based on the bound state in the continuum(BIC)has provided a feasible approach to solve these problems.In this paper,we propose a metasurface structure consisting of a single size tetramer cylinder.It supports dual band toroidal dipole(TD)resonances driven by BIC.The physical mechanism of double TD resonances is clarified by the multipole decomposition of the metasurface band structure and far-field scattering power.The sensor structure based on this achieves a sensitivity of 518.3 MHz/RIU,and the maximum line width does not exceed 680kHz.The high-Q-factor electromagnetic resonance has the advantages of polarization independence and simplicity to manufacture.These findings will open up an avenue to develop the ultrasensitive sensor in the gigahertz regime.展开更多
Efficiently modifying glycals by directly introducing functional groups into their double bonds is a longstanding challenge.Here,the strategy of introducing two different functional groups into 1-iodoglycals to obtain...Efficiently modifying glycals by directly introducing functional groups into their double bonds is a longstanding challenge.Here,the strategy of introducing two different functional groups into 1-iodoglycals to obtain modified glycals in one step through palladium catalysis was reported for the first time,and the modified glycals contained stereodefined tetrasubstituted olefins.Using this method,various difunctionalized glycals that were difficult to form by other routes were synthesized in moderate to good yields.Control experiments and density functional theory calculations show that the palladium catalyst played dual roles in this transformation,namely,inducing nucleophilic substitution and catalyzing Suzuki coupling.The reaction intermediate was isolated and confirmed by X-ray crystallographic analysis.Furthermore,the gram-scale synthesis and facile deprotection of the target compound enhances the practicality of this strategy.展开更多
Plant diseases cause dramatic economic loss,posing a major challenge to modern agriculture.Plant pathogenic organisms secret effectors that utilize fascinating and intricate stratagems to facilitate infection.The cons...Plant diseases cause dramatic economic loss,posing a major challenge to modern agriculture.Plant pathogenic organisms secret effectors that utilize fascinating and intricate stratagems to facilitate infection.The consequences of plant-pathogen interactions are largely determined by effectors.The effector research has made great strides since its inception in the 1990s and the importance of effectors is increasingly noticed.Molecular investigation of effectors has provided critical insights into how plant pathogens manipulate their hosts to cause diseases.Thus far,numerous excellent reviews concerning effectors have focused on their targeting host pathways,recognition by host receptors,and evasion mechanisms,but few have ever summarized all known effector action modes.Here,we distinguish ten different stratagems of effector function from all types of pathogens,including damage,inhibition,hijacking,promotion,subversion,mimicry,reprogramming,evasion,decoying,and adaption.Furthermore,we discuss examples of these ten stratagems,refine the effector definition,and propose future directions of phytopathogenic effector research.展开更多
Electron correlation often gives birth to various orders in quantum materials.Recently,a strongly correlated kagome antiferromagnet Fe Ge is discovered to undergo a charge density wave transition inside the A-type ant...Electron correlation often gives birth to various orders in quantum materials.Recently,a strongly correlated kagome antiferromagnet Fe Ge is discovered to undergo a charge density wave transition inside the A-type antiferromagnetic state,providing an opportunity to explore the interplay between charge order and magnetism.Here,we reported the observation of anisotropic resistivity and Hall effect,along with a topological Hall effect,in the annealed Fe Ge crystals.As the current flows along the abplane,the temperature dependence ofρ_(ab)exhibits a distinct resistivity loop related to a first-order transition at T_(cdw).The applied magnetic fields do not alter T_(cdw)but can induce a spin-flop transition at H_(sf).Consequently,a field-induced large topological Hall effect is observed in the canting antiferromagnetic(CAFM)state below T_(cant),which is possibly attributed to the non-trivial spin texture during the spin-flop process.Whereas,as current is parallel to c-axis,both the field-induced transitions inρ_(c)andχ_(c)disappear.Instead,the Hall resistivity in the annealed Fe Ge significantly exhibits a deviation from the linear field-dependent.These findings provide valuable insight into revealing the interplay among magnetism,charge order and topology in the kagome magnets.展开更多
RNAs are involved in the crucial processes of disease progression and have emerged as powerful therapeutic targets and diagnostic biomarkers.However,efficient delivery of therapeutic RNA to the targeted location and p...RNAs are involved in the crucial processes of disease progression and have emerged as powerful therapeutic targets and diagnostic biomarkers.However,efficient delivery of therapeutic RNA to the targeted location and precise detection of RNA markers remains challenging.Recently,more and more attention has been paid to applying nucleic acid nanoassemblies in diagnosing and treating.Due to the flexibility and deformability of nucleic acids,the nanoassemblies could be fabricated with different shapes and structures.With hybridization,nucleic acid nanoassemblies,including DNA and RNA nanostructures,can be applied to enhance RNA therapeutics and diagnosis.This review briefly introduces the construction and properties of different nucleic acid nanoassemblies and their applications for RNA therapy and diagnosis and makes further prospects for their development.展开更多
Based on a combination of X-ray diffraction, electrical transports, magnetic susceptibility, specific heat, and pressure-effect measurements, we report the results of experiments on a series of BiS_2-based Sr_(1-x)Pr_...Based on a combination of X-ray diffraction, electrical transports, magnetic susceptibility, specific heat, and pressure-effect measurements, we report the results of experiments on a series of BiS_2-based Sr_(1-x)Pr_xFBiS_2 superconductors with the maximum Tcof 2.7 K for x=0.5 and at ambient pressure. Superconductivity appears only for 0.4≤x≤0.7 whereas the normal-state resistivity shows the semiconducting-like behaviors. The magnetic susceptibility χ(T) displays the low superconducting shielding volume fractions and C(T) shows no distinguishable anomaly near Tc, which suggests a filamentary superconductivity in the Pr-doped polycrystalline samples. By varying doping concentrations, an electronic phase diagram is established. Upon applying pressure on the optimally doped Sr_(0.5)Pr_(0.5)FBiS_2 system, Tcis abruptly enhanced, reaches 8.5 K at the critical pressure of P_c=1.5 GPa, and increases slightly to 9.7 K at 2.5 GPa. Accompanied by the enhancement of superconductivity from the low-to the high-Tc phases, the normal state undergoes a semiconductor-to-metal transition when under pressure. This scenario may be linked to enhanced overlap of the Bi-6 p and S-p orbitals, which contributes to the enhanced superconductivity above Pc. The pressuretemperature phase diagram for Sr_(0.5)Pr_(0.5)FBiS_2 is also presented.展开更多
By engineering strain gradients in dielectrics,the flexoelectric effect can be created,which yields interesting physical properties via electromechanical coupling.Here,we report flexoelectric-induced photovoltaic effe...By engineering strain gradients in dielectrics,the flexoelectric effect can be created,which yields interesting physical properties via electromechanical coupling.Here,we report flexoelectric-induced photovoltaic effects in centrosymmetric LaFeO_(3) thin-film heterostructures grown on flexible mica sub-strates,in which partial relaxation of lattice-mismatch strain against LaAlO_(3) stretching layers results in giant strain gradients and pronounced electrical polarizations.The flexoelectric polarization modulates band alignment and leads to significant photovoltaic effects with a short-circuit current density of~0.4 mA/cm^(2) and an open circuit voltage of~-0.45 V in Pt/LaFeO_(3)/LaNiO_(3) devices.In addition,by con-cavely/convexly bending the mica substrate,mechanical strain gradients give rise to bi-directionally tunable photocurrents,in which continuously change of short-circuit current density with a magni-tude of~100% and good reproducibility in repetitive bending operations are observed in the Pt/LaFeO_(3)/LaNiO_(3) devices.The present work demonstrates an approach to design self-powered photoelectric de-vices with an electromechanical degree of freedom based on the flexoelectric effect in flexible thin-film heterostructures.展开更多
Anomalous Nernst effect, as a thermal partner of anomalous Hall effect, is particularly sensitive to the Berry curvature anomaly near the Fermi level, and has been used to probe the topological nature of quantum mater...Anomalous Nernst effect, as a thermal partner of anomalous Hall effect, is particularly sensitive to the Berry curvature anomaly near the Fermi level, and has been used to probe the topological nature of quantum materials. In this work, we report the observation of both effects in the ferromagnetic Weyl-semimetal Fe_(3-δ)GeTe_(2) with tunable Fe vacancies. With decreasing Fe vacancies,the anomalous Hall conductivity evolves as a function of the longitudinal conductivity from the hopping region to the region where the intrinsic Berry curvature contribution dominates. Concomitant evolutions in the anomalous Nernst signal and the anomalous off-diagonal thermoelectric coefficient are observed below the Curie temperature, displaying a unique sign change caused by the Fe vacancies. Combining these results with first-principles calculations, we argue that the Fe-vacancy concentration plays a unique role in simultaneously tuning the chemical potential and ferromagnetism, which in turn controls the Berry curvature contribution in this family of ferromagnetic topological semimetals.展开更多
Semantic segmentation is an important sub-task for many applications.However,pixel-level ground-truth labeling is costly,and there is a tendency to overfit to training data,thereby limiting the generalization ability....Semantic segmentation is an important sub-task for many applications.However,pixel-level ground-truth labeling is costly,and there is a tendency to overfit to training data,thereby limiting the generalization ability.Unsupervised domain adaptation can potentially address these problems by allowing systems trained on labelled datasets from the source domain(including less expensive synthetic domain)to be adapted to a novel target domain.The conventional approach involves automatic extraction and alignment of the representations of source and target domains globally.One limitation of this approach is that it tends to neglect the differences between classes:representations of certain classes can be more easily extracted and aligned between the source and target domains than others,limiting the adaptation over all classes.Here,we address:this problem by introducing a Class-Conditional Domain Adaptation(CCDA)method.This incorporates a class-conditional multi-scale discriminator and class-conditional losses for both segmentation and adaptation.Together,they measure the segmentation,shift the domain in a classconditional manner,and equalize the loss over classes.Experimental results demonstrate that the performance of our CCDA method matches,and in some cases,surpasses that of state-of-the-art methods.展开更多
基金supported by the Clinical Medicine Plus X-Young Scholars Project of Peking University of the Fundamental Research Funds for the Central Universities (PKU2023LCXQ035)the Chinese Academy of Medical Sciences Central Public-Interest Scientific Institution Basal Research Fund (2022-JKCS-27)+3 种基金the National clinical key discipline construction project (PKUSSNKP-202114)China Postdoctoral Science Foundation (2022M720289)Chinese Stomatological Association Clinical Research Fund (CSA-SIS2022-01)National Natural Science Foundation of China (82301024)
文摘Recent studies have suggested that long-term application of anti-angiogenic drugs may impair oral mucosal wound healing.This study investigated the effect of sunitinib on oral mucosal healing impairment in mice and the therapeutic potential of Bifidobacterium breve(B.breve).A mouse hard palate mucosal defect model was used to investigate the influence of sunitinib and/or zoledronate on wound healing.The volume and density of the bone under the mucosal defect were assessed by micro-computed tomography(micro-CT).Inflammatory factors were detected by protein microarray analysis and enzyme-linked immunosorbent assay(ELISA).The senescence and biological functions were tested in oral mucosal stem cells(OMSCs)treated with sunitinib.Ligated loop experiments were used to investigate the effect of oral B.breve.Neutralizing antibody for interleukin-10(IL-10)was used to prove the critical role of IL-10 in the pro-healing process derived from B.breve.Results showed that sunitinib caused oral mucosal wound healing impairment in mice.In vitro,sunitinib induced cellular senescence in OMSCs and affected biological functions such as proliferation,migration,and differentiation.Oral administration of B.breve reduced oral mucosal inflammation and promoted wound healing via intestinal dendritic cells(DCs)-derived IL-10.IL-10 reversed cellular senescence caused by sunitinib in OMSCs,and IL-10 neutralizing antibody blocked the ameliorative effect of B.breve on oral mucosal wound healing under sunitinib treatment conditions.In conclusion,sunitinib induces cellular senescence in OMSCs and causes oral mucosal wound healing impairment and oral administration of B.breve could improve wound healing impairment via intestinal DCs-derived IL-10.
基金supported by the Degradable Plastics Engineering Research Center of Yunnan Provincial Education Department(KKPU202205001).
文摘Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–glycerol system.Longer whiskers were obtained from crystal seeds prepared via hydration of DH for 30 s than via ball milling for 5 min followed by hydration for 20 s.The attachment of cetyltrimethyl ammonium bromide and glycerol additives to the whisker tops promoted whisker growth.The whisker sponges exhibited good thermal barrier properties and compression cycle stability.
基金supported in part by the Natural Science Foundation of China(Grant No.U1932155)the Hangzhou Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LHZSZ24A040001)+4 种基金the National Key R&D Program of China(Grant No.2022YFA1602602)the National Key R&D Program of China(Grant Nos.2022YFA1403800 and 20-23YFA1406500)the China Postdoctoral Science Foundation(Grant No.2023-M730011)the National Natural Science Foundation of China(Grant No.12274459)supported by the HZNU Scientific Research and Innovation Team Project(No.TD2025013)。
文摘In magnetic topological materials,the interplay between magnetism and nontrivial topology gives rise to exotic quantum transport phenomena,including the anomalous Hall effect and anomalous Nernst effect.Here,we report the observation of intrinsic topological Hall and topological Nernst effects below the Néel temperature(T_(N)=25 K)in the antiferromagnetic(AFM)topological insulator Mn Bi_(2)Te_(4).The maximum of topological Hall resistivity reaches approximately 9μΩ·cm at 2 K,while the topological Nernst signal attains a peak value of 0.1μV/K near 10 K.These anomalous transport behaviors originate from the net Berry curvature induced by the non-collinear spin structure in the canted AFM state.Our results suggest a close connection between the topological thermoelectric effect and non-collinear AFM order in AFM topological insulators.
基金supported by the National Science Foundation(1607101.00)USAir Force(FA9550-16-1-0290)
文摘The well-known Braess paradox in congestion games states that adding an additional road to a transportation network may increase the total travel time, and consequently decrease the overall efficiency. This paper presents a paradox in a similar spirit and involves a distributed resource allocation game on networks, namely the power allocation game between countries developed in Li and Morse(2017). The paradox is that by having additional friends may actually decrease a country's total welfare in equilibrium. Conditions for this paradox to occur as well as the price of anarchy results are also derived.
文摘Based on such severe situation, we need to work out a way that enables us to analyze the current and future ability of a region to provide clean water to meet the needs of its population, and to develop a reasonable strategy to optimize the utilization of water resources in this area. This paper has worked out a resolution model and input the data of China, the United States, Russia, Laos and Afghanistan to do national testing. Then, we use the policy from “diaper incident” to do policy testing. The calculation results of the model are in conformity with the reality. Therefore, the model is effective. At last this model is used to resolve Gansu’s water problem and provide effective advices for the local government.
基金supported by the National Natural Science Foundation of China(Grant 52072041)the Beijing Natural Science Foundation(Grant JQ21007)the University of Chinese Academy of Sciences(Grant Y8540XX2D2).
文摘Tactile sensors are a potential solution for material identification.However,current potential tactile sensors for material identification are pressed,expensive,and applications-confined.Here we report a clamped-on pyroelectric tactile sensor on the basis of a ferroelectric Bi_(0.5)Na_(0.5)TiO_(3) material to identify different film materials.The fabricated device exhibits different heat absorption capacities while in contact with different materials,leading to a different temperature change in the ferroelectric material under the same illumination.As a result,the device can recognize different materials by comparing the pyroelectric charge via integrating the obtained current under the same irradiation of 365nmlight-emitting diode.The clamped-on pyroelectric tactile sensor can identify six individual materials with a high accuracy of 98.8%and a fast response of 40 ms.All of the above processes can be accomplished with an intelligent material identification system.The device provides a new solution for material identification and lays a foundation for smart factories and laboratories.
基金supported in part by the U.S.National Science Foundation under Grant No.CCF-2132049,a Google Research Award,and a Meta Faculty Research Awardthe Expanse cluster at SDSC(San Diego Supercomputer Center)through allocation CIS210053 from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)program,which is supported by the U.S.National Science Foundation under Grant Nos.2138259,2138286,2138307,2137603,and 2138296.
文摘Machine learning techniques have become ubiquitous both in industry and academic applications.Increasing model sizes and training data volumes necessitate fast and efficient distributed training approaches.Collective communications greatly simplify inter-and intra-node data transfer and are an essential part of the distributed training process as information such as gradients must be shared between processing nodes.In this paper,we survey the current state-of-the-art collective communication libraries(namely xCCL,including NCCL,oneCCL,RCCL,MSCCL,ACCL,and Gloo),with a focus on the industry-led ones for deep learning workloads.We investigate the design features of these xCCLs,discuss their use cases in the industry deep learning workloads,compare their performance with industry-made benchmarks(i.e.,NCCL Tests and PARAM),and discuss key take-aways and interesting observations.We believe our survey sheds light on potential research directions of future designs for xCCLs.
基金the National Natural Science Foundation of China(Nos.NSF22061038,NSF22067018)the Long Yuan Youth Innovative Project of Gansu Province(No.2019-39)+1 种基金the Northwest Normal University Young Scholars Research Capacity Improvement Program(No.NWNU-LKQN-2020-04)Computations reported in this paper were performed on the computer clusters at the Centre for Scientific Modeling and Computation,CUHK.
文摘This paper describes the first case of a reductive coupling reaction with indene,a non-heteroatom olefin used as a reducing agent.The scope of the substrate is wide.The homo-coupling,cross-coupling,and synthesis of 12 and 14-membered rings were realized.The control experiment,indene-product curve and density functional theory calculations showed that the η^(3)-palladium indene intermediate was formed by C-H activation in the presence of cesium carbonate.We speculate that the final product was obtained through a Pd(IV)intermediate or aryl ligand exchange.In addition,we excluded the formation of palladium anion(Pd(0)^(-))intermediates.
基金supported by the Open Research Fund of Songshan Lake Materials Laboratory(Grant No.2022SLABFN27)National Natural Science Foundation of China(Grant Nos.12274364,and U1932155)+3 种基金Fundamental Research Funds for the Central Universities of China(Grant No.2019kfy XMBZ071)National Key R&D Program of China(Grant No.2022YFA1602602)Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515120020)Pioneer and Leading Goose R&D Program of Zhejiang(Grant No.2022SDXHDX0005)。
文摘Topological magnetic Weyl semimetals have been proposed to host controllable chiral domain walls which bear a great prospect in device applications. To exploit them in applications, it is important to have a proper way to tune and manipulate these domain walls. One possible means is through magnetoelastic coupling. The involvement of rare earth in the lately proposed RAl X(R =rare earth, X = Si and Ge) family magnetic Weyl semimetals may provide such a platform. Here we present the transport and thermodynamic properties of Ce Al Ge under hydrostatic pressure. We find that pressure enhances the antiferromagnetic exchange in Ce Al Ge but essentially retains its magnetic structure. A large topological Hall effect with a pronounced loop shape is observed within the magnetically ordered state, and it splits into two regions under pressure. Such an unusual electromagnetic response is inferred to be a consequence of chiral magnetic domain walls. The unprecedented concomitance of its evolution under pressure and the reentrance of antiferromagnetic order strongly suggest the capability of switching on/off this electromagnetic response in noncentrosymmetric magnetic Weyl semimetals via magnetoelastic coupling.
基金supported in part by the National Natural Science Foundation of China(Grant No.11811530052)Intergovernmental Scienceand Technology Regular Meeting Exchange Project of Ministry of Science and Technology of China(Grant No.CB02-20)+1 种基金Open Fund of State Key Laboratory of Applied Optics(Grant No.SKLA02020001A04)Undergraduate Research and Innovation Projects of China(Grant No.2021102Z).
文摘High-quality-factor(high-Q-factor)electromagnetic resonance plays an important role in sensor applications.Previously proposed gas refractive index sensors are often limited by the large cavity length or microscale fabrication process in practical applications.Recently,ultra-high Q factor resonance based on the bound state in the continuum(BIC)has provided a feasible approach to solve these problems.In this paper,we propose a metasurface structure consisting of a single size tetramer cylinder.It supports dual band toroidal dipole(TD)resonances driven by BIC.The physical mechanism of double TD resonances is clarified by the multipole decomposition of the metasurface band structure and far-field scattering power.The sensor structure based on this achieves a sensitivity of 518.3 MHz/RIU,and the maximum line width does not exceed 680kHz.The high-Q-factor electromagnetic resonance has the advantages of polarization independence and simplicity to manufacture.These findings will open up an avenue to develop the ultrasensitive sensor in the gigahertz regime.
基金We thank the National Natural Science Foundation of China(NSF 22171114 and 21772075)for its financial support.
文摘Efficiently modifying glycals by directly introducing functional groups into their double bonds is a longstanding challenge.Here,the strategy of introducing two different functional groups into 1-iodoglycals to obtain modified glycals in one step through palladium catalysis was reported for the first time,and the modified glycals contained stereodefined tetrasubstituted olefins.Using this method,various difunctionalized glycals that were difficult to form by other routes were synthesized in moderate to good yields.Control experiments and density functional theory calculations show that the palladium catalyst played dual roles in this transformation,namely,inducing nucleophilic substitution and catalyzing Suzuki coupling.The reaction intermediate was isolated and confirmed by X-ray crystallographic analysis.Furthermore,the gram-scale synthesis and facile deprotection of the target compound enhances the practicality of this strategy.
基金supported by the National Natural Science Foundation of China(32202251,32230089 and 32070139)China Agriculture Research System(CARS-21).
文摘Plant diseases cause dramatic economic loss,posing a major challenge to modern agriculture.Plant pathogenic organisms secret effectors that utilize fascinating and intricate stratagems to facilitate infection.The consequences of plant-pathogen interactions are largely determined by effectors.The effector research has made great strides since its inception in the 1990s and the importance of effectors is increasingly noticed.Molecular investigation of effectors has provided critical insights into how plant pathogens manipulate their hosts to cause diseases.Thus far,numerous excellent reviews concerning effectors have focused on their targeting host pathways,recognition by host receptors,and evasion mechanisms,but few have ever summarized all known effector action modes.Here,we distinguish ten different stratagems of effector function from all types of pathogens,including damage,inhibition,hijacking,promotion,subversion,mimicry,reprogramming,evasion,decoying,and adaption.Furthermore,we discuss examples of these ten stratagems,refine the effector definition,and propose future directions of phytopathogenic effector research.
基金supported by the National Natural Science foundation of China(Grant Nos.U1932155,12374116,12204298 and 12274109)the Hangzhou Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LHZSZ24A040001)funded by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515120020)。
文摘Electron correlation often gives birth to various orders in quantum materials.Recently,a strongly correlated kagome antiferromagnet Fe Ge is discovered to undergo a charge density wave transition inside the A-type antiferromagnetic state,providing an opportunity to explore the interplay between charge order and magnetism.Here,we reported the observation of anisotropic resistivity and Hall effect,along with a topological Hall effect,in the annealed Fe Ge crystals.As the current flows along the abplane,the temperature dependence ofρ_(ab)exhibits a distinct resistivity loop related to a first-order transition at T_(cdw).The applied magnetic fields do not alter T_(cdw)but can induce a spin-flop transition at H_(sf).Consequently,a field-induced large topological Hall effect is observed in the canting antiferromagnetic(CAFM)state below T_(cant),which is possibly attributed to the non-trivial spin texture during the spin-flop process.Whereas,as current is parallel to c-axis,both the field-induced transitions inρ_(c)andχ_(c)disappear.Instead,the Hall resistivity in the annealed Fe Ge significantly exhibits a deviation from the linear field-dependent.These findings provide valuable insight into revealing the interplay among magnetism,charge order and topology in the kagome magnets.
基金supported by the National Science Foundation of China(No.82003689,to Mengnan Zhao,China)the Outstanding Young Scientific Talent Foundation of Sichuan Province(No.2022JDJQ0052,to Sanjun Shi,China)+3 种基金the China Postdoctoral Science Foundation(No.2021M690489,to Mengnan Zhao,China)the Project of High-Level Talents in Sichuan Province(No.003113014003,to Sanjun Shi,China)the International Postdoctoral Exchange Fellowship Program(No.YJ20200040,to Mengnan Zhao,China)the Xinglin Scholar Research Promotion Project of Chengdu University of Traditional Chinese Medicine(No.BSH2020006,to Mengnan Zhao,China).
文摘RNAs are involved in the crucial processes of disease progression and have emerged as powerful therapeutic targets and diagnostic biomarkers.However,efficient delivery of therapeutic RNA to the targeted location and precise detection of RNA markers remains challenging.Recently,more and more attention has been paid to applying nucleic acid nanoassemblies in diagnosing and treating.Due to the flexibility and deformability of nucleic acids,the nanoassemblies could be fabricated with different shapes and structures.With hybridization,nucleic acid nanoassemblies,including DNA and RNA nanostructures,can be applied to enhance RNA therapeutics and diagnosis.This review briefly introduces the construction and properties of different nucleic acid nanoassemblies and their applications for RNA therapy and diagnosis and makes further prospects for their development.
基金supported by the National Natural Science Foundation of China(Grant Nos.11474082,61401136,and 61376094)the Natural Science Foundation of Zhejiang Province(Grant No.LY18F010019)+3 种基金the QianJiang Talents Program of Zhejiang Provincesupported by an open program from Wuhan National High Magnetic Field Center(Grant No.2016KF03)supported by the General Program of Natural Science Foundation of Jiangsu Province of China(Grant No.BK20171440)the support from the 1000Youth Talents Plan of China
文摘Based on a combination of X-ray diffraction, electrical transports, magnetic susceptibility, specific heat, and pressure-effect measurements, we report the results of experiments on a series of BiS_2-based Sr_(1-x)Pr_xFBiS_2 superconductors with the maximum Tcof 2.7 K for x=0.5 and at ambient pressure. Superconductivity appears only for 0.4≤x≤0.7 whereas the normal-state resistivity shows the semiconducting-like behaviors. The magnetic susceptibility χ(T) displays the low superconducting shielding volume fractions and C(T) shows no distinguishable anomaly near Tc, which suggests a filamentary superconductivity in the Pr-doped polycrystalline samples. By varying doping concentrations, an electronic phase diagram is established. Upon applying pressure on the optimally doped Sr_(0.5)Pr_(0.5)FBiS_2 system, Tcis abruptly enhanced, reaches 8.5 K at the critical pressure of P_c=1.5 GPa, and increases slightly to 9.7 K at 2.5 GPa. Accompanied by the enhancement of superconductivity from the low-to the high-Tc phases, the normal state undergoes a semiconductor-to-metal transition when under pressure. This scenario may be linked to enhanced overlap of the Bi-6 p and S-p orbitals, which contributes to the enhanced superconductivity above Pc. The pressuretemperature phase diagram for Sr_(0.5)Pr_(0.5)FBiS_2 is also presented.
基金This work was jointly sponsored by Natural Science Foundation of China(51872148)Natural Science Foundation of Shandong Province(ZR2020JQ03)+2 种基金D.W.acknowledges financial support from Natural Science Foundation of China(51725203 and U1932115)Z.W.acknowledges financial support from the Taishan Scholar Program of Shandong Province(tsqn201812045)the Youth Innovation Team Project of Shandong Provincial Education Department(2019KJJ012).
文摘By engineering strain gradients in dielectrics,the flexoelectric effect can be created,which yields interesting physical properties via electromechanical coupling.Here,we report flexoelectric-induced photovoltaic effects in centrosymmetric LaFeO_(3) thin-film heterostructures grown on flexible mica sub-strates,in which partial relaxation of lattice-mismatch strain against LaAlO_(3) stretching layers results in giant strain gradients and pronounced electrical polarizations.The flexoelectric polarization modulates band alignment and leads to significant photovoltaic effects with a short-circuit current density of~0.4 mA/cm^(2) and an open circuit voltage of~-0.45 V in Pt/LaFeO_(3)/LaNiO_(3) devices.In addition,by con-cavely/convexly bending the mica substrate,mechanical strain gradients give rise to bi-directionally tunable photocurrents,in which continuously change of short-circuit current density with a magni-tude of~100% and good reproducibility in repetitive bending operations are observed in the Pt/LaFeO_(3)/LaNiO_(3) devices.The present work demonstrates an approach to design self-powered photoelectric de-vices with an electromechanical degree of freedom based on the flexoelectric effect in flexible thin-film heterostructures.
基金supported by the National Natural Science Foundation of China (Grant Nos. U1932155, 11874136, 11874137, and U19A2093)the National Key Projects for Research and Development of China (Grant No. 2019YFA0308602)+1 种基金the Key R&D Program of Zhejiang Province China (Grant No. 2021C01002)supported by an open program from Wuhan National High Magnetic Field Center (Grant No. 2016KF03)。
文摘Anomalous Nernst effect, as a thermal partner of anomalous Hall effect, is particularly sensitive to the Berry curvature anomaly near the Fermi level, and has been used to probe the topological nature of quantum materials. In this work, we report the observation of both effects in the ferromagnetic Weyl-semimetal Fe_(3-δ)GeTe_(2) with tunable Fe vacancies. With decreasing Fe vacancies,the anomalous Hall conductivity evolves as a function of the longitudinal conductivity from the hopping region to the region where the intrinsic Berry curvature contribution dominates. Concomitant evolutions in the anomalous Nernst signal and the anomalous off-diagonal thermoelectric coefficient are observed below the Curie temperature, displaying a unique sign change caused by the Fe vacancies. Combining these results with first-principles calculations, we argue that the Fe-vacancy concentration plays a unique role in simultaneously tuning the chemical potential and ferromagnetism, which in turn controls the Berry curvature contribution in this family of ferromagnetic topological semimetals.
基金funded by the Ontario Research Fund-Research Excellence program for their supports.
文摘Semantic segmentation is an important sub-task for many applications.However,pixel-level ground-truth labeling is costly,and there is a tendency to overfit to training data,thereby limiting the generalization ability.Unsupervised domain adaptation can potentially address these problems by allowing systems trained on labelled datasets from the source domain(including less expensive synthetic domain)to be adapted to a novel target domain.The conventional approach involves automatic extraction and alignment of the representations of source and target domains globally.One limitation of this approach is that it tends to neglect the differences between classes:representations of certain classes can be more easily extracted and aligned between the source and target domains than others,limiting the adaptation over all classes.Here,we address:this problem by introducing a Class-Conditional Domain Adaptation(CCDA)method.This incorporates a class-conditional multi-scale discriminator and class-conditional losses for both segmentation and adaptation.Together,they measure the segmentation,shift the domain in a classconditional manner,and equalize the loss over classes.Experimental results demonstrate that the performance of our CCDA method matches,and in some cases,surpasses that of state-of-the-art methods.
