The utilization of covalent organic frameworks(COFs)holds great potential for achieving tailorable tuning of catalytic performance through bottom-up modulation of the reticular structure.In this work,we show that a si...The utilization of covalent organic frameworks(COFs)holds great potential for achieving tailorable tuning of catalytic performance through bottom-up modulation of the reticular structure.In this work,we show that a single-point structural alteration in the linkage within a nickel phthalocyanine(NiPc)-based series effectively modulates the catalytic performance of the COFs in electrochemical CO_(2)reduction reaction(CO_(2)RR).A Ni Pc-based COF series with three members which possess the same Ni Pc unit but different linkages,including piperazine,dioxin,and dithiine,have been constructed by nucleophilic aromatic substitution reaction between octafluorophthalocyanine nickel and tetrasubstituted benzene linkers with different bridging groups.Among these COFs,the dioxin-linked COF showed the best activity of CO_(2)RR with a current density of CO(j_(CO))=-27.99 m A cm^(-2)at-1.0 V(versus reversible hydrogen electrode,RHE),while the COF with piperazine linkage demonstrated an excellent selectivity of Faradaic efficiency for CO(FECO)up to 90.7%at a pretty low overpotential of 0.39 V.In addition,both a high FECO value close to 100%and a reasonable jCO of-8.20 m A cm^(-2)at the potential of-0.8 V(versus RHE)were obtained by the piperazine-linked COF,making it one of the most competitive candidates among COF-based materials.Mechanistic studies exhibited that single-point structural alteration could tailor the electron density in Ni sites and alter the interaction between the active sites and the key intermediates adsorbed and desorbed,thereby tuning the electrochemical performance during CO_(2)RR process.展开更多
Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electric...Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electrical conductivity.However,the contribution of metal nodes to the overall electrical properties remains unclear.In this work,we systematically investigate the role of metal centers on a series of six highly crystalline hexahydroxytriphenylene(HHTP)based c-MOFs,M-HHTP,which incorporate alkaline earth including magnesium and calcium,as well as transition metals including cobalt,nickel,copper,and zinc.Comprehensive structural characterizations reveal that while all M-HHTP frameworks adopt a general honeycomb lattice,however,subtle variations in stacking patterns and coordination environments are induced by different metal ions.Electrical measurements show a pronounced dependence of conductivity on the nature of the metal nodes,in which the conductivity differs by four orders of magnitude due to the difference in metal centers.Furthermore,non-contact terahertz spectroscopy combined with theoretical calculations suggests that in alkaline earth metal-based MOFs,charge transport may proceed via a through-space hopping mechanism between organic ligands.This study elucidates the critical role of metal centers in governing charge transport in M-HHTP MOFs and offers valuable guidance for the rational design of high-performance 2D conductive frameworks.展开更多
Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale...Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale deployment of the technology.Coupling energy-efficient electrooxidation of biomassderived glycerol and cathodic hydrogen evolution reaction provides a promising strategy for improving the techno-economics of the water electrolysis technology.Herein,by dispersing transition metal elements with weak d-p coupling strength into the MnO_(2)lattice,the fine tuning of the bioctahedral d-p orbital in MnO_(2)is successfully realized,which greatly accelerates the hydrogen transfer in glycerol oxidation.In-situ Raman results confirmed that Ni–MnO_(2)could spontaneously activate glycerol molecules and drive hydrogen transfer to lattice oxygen sites,leading to the occurrence of successive phase transitions(α-MnO_(2)→Mn_(3)O_(4)→MnOOH).Density functional theory(DFT)calculations revealed that the incorporation of Ni broadened the d-orbital and regulated the distribution of p-orbitals near the oxygen Fermi level in the lattice,resulting in a relatively high empty orbital state to facilitate the hydrogen transfer process.The optimal Ni–MnO_(2)delivered a low potential of 1.16 V vs.RHE to reach 10 mA cm^(-2),a high FE of 99.7%for formate,and superior durability over 80 h.This work provides new insights into balancing the adsorption and activation of biomass molecules while casting a universal strategy for developing efficient biomass oxidation electrocatalysts.展开更多
Planning the low-carbon transition pathway of the power sector to meet the carbon neutrality goal poses a significant challenge due to the complex interplay of temporal,spatial,and cross-domain factors.A novel framewo...Planning the low-carbon transition pathway of the power sector to meet the carbon neutrality goal poses a significant challenge due to the complex interplay of temporal,spatial,and cross-domain factors.A novel framework is proposed,grounded in the cyber-physical-social system in energy(CPSSE)and whole-reductionism thinking(WRT),incorporating a tailored mathematical model and optimization method to formalize the co-optimization of carbon reduction and carbon sequestration in the power sector.Using the carbon peaking and carbon neutrality transition of China as a case study,clustering method is employed to construct a diverse set of strategically distinct carbon trajectories.For each trajectory,the evolution of the generation mix and the deployment pathways of carbon capture and storage(CCS)technologies are analyzed,identifying the optimal transition pathway based on the criterion of minimizing cumulative economic costs.Further,by comparing non-fossil energy substitution and CCS retrofitting in thermal power,the analysis highlights the potential for co-optimization of carbon reduction and carbon sequestration.The results demonstrate that leveraging the spatiotemporal complementarities between the two can substantially lower the economic cost of achieving carbon neutrality,providing insights for integrated decarbonization strategies in power system planning.展开更多
Correction:aBIOTECH https://doi.org/10.1007/s42994-025-00214-7 The original article contained several errors caused in the production process of the article:In this article the affiliation‘State Key Laboratory of See...Correction:aBIOTECH https://doi.org/10.1007/s42994-025-00214-7 The original article contained several errors caused in the production process of the article:In this article the affiliation‘State Key Laboratory of Seed Innovation,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing,100101,China’for Author Jia Yuan was missing.Greek letters and other symbols were missing in Figs.1 and 4 have now been included.展开更多
Plant specialized metabolites are commonly stored in glycosylated forms within plant cells,with their homeostasis regulated by glycosyltransferases andβ-glucosidases(BGLUs,also known asβ-glucoside hydrolases(E.C.3.2...Plant specialized metabolites are commonly stored in glycosylated forms within plant cells,with their homeostasis regulated by glycosyltransferases andβ-glucosidases(BGLUs,also known asβ-glucoside hydrolases(E.C.3.2.1.21)).Soyasaponins,the predominant triterpenoid compounds(C30)in soybean seeds,contain two sugar moieties attached at the C3 and C22 positions.While glycosyltransferases involved in soyasaponin biosynthesis have been well characterized,the role of BGLUs in soyasaponin homeostasis remains unclear.In this study,we identified GmSSBG1(Soyasaponinβ-glucosidase1;Glyma.07G258700)as a candidate gene potentially involved in soyasaponin homeostasis through gene to gene co-expression analysis.Biochemical assays demonstrated that GmSSBG1 specifically hydrolyzes arabinose residues at the C22 position of A0-and B0-series soyasaponins.Loss-of-function mutations in GmSSBG1 led to a significant accumulation of A0-and B0-series soyasaponins in mutant seeds,which correlated with a pronounced decrease in resistance to the soybean pod borer(Leguminivora glycinivorella).Our findings provide critical insights into the regulatory mechanisms underlying soyasaponin homeostasis and lay a theoretical foundation for molecular breeding strategies aimed at developing soybean lines with enhanced resistance to soybean pod borer,even to other insect pests.展开更多
As generative AI is increasingly integrated into emotionally intimate contexts,concerns about its reproduction of gender bias are growing.While existing scholarship has extensively explored static biases in dataset an...As generative AI is increasingly integrated into emotionally intimate contexts,concerns about its reproduction of gender bias are growing.While existing scholarship has extensively explored static biases in dataset and model design,few studies have explored how gender stereotypes evolve and are reinforced through dynamic human-computer interactions.This study examines how emotionally sustained conversations with an AI agent(e.g.,ChatGPT)gradually stabilize and amplify symbolic gender roles through ritualized discourse patterns.Drawing on the Computers as Social Actors(CASA)paradigm and Interactive Ritual Chaining(IRC)theory,this study explores how users co-construct relational expectations with AI systems over time.Using a two-stage corpus design containing eight participants,we compared lexical frames and emotional tones in the preand post-phases of intimate interaction.Results suggest that the AI’s responses increasingly conformed to normative gender roles:women were positioned as emotional receivers,while men were shaped as resilience providers-even when expressing similar emotional needs.These findings highlight that dynamic biases are not only deeply ingrained,but also reinforced by the way they are interacted with,creating new ethical challenges for relational fairness in AI communication.By shifting the focus from static design issues to ongoing dialogic reproduction of gender meaning,this study contributes to a deeper understanding of algorithmic bias in virtual companionship.展开更多
Tail artifacts are a significant issue in optical coherence tomography angiography[OCTA],as they cast shadows over underlying signals and interfere with the reconstruction of 3D vessel images.While many methods have b...Tail artifacts are a significant issue in optical coherence tomography angiography[OCTA],as they cast shadows over underlying signals and interfere with the reconstruction of 3D vessel images.While many methods have been developed to reduce these artifacts,most only shorten the tails and fail to clearly distinguish between vessels and artifacts.In this Letter,we present an image processing technique designed to reduce artifacts.By combining structural images with OCTA images,we can more effectively distinguish between vessels and artifacts,leading to shorter and less pronounced tail artifacts.This method is integrated with other tail artifact removal techniques to further enhance image quality.The vessels of the palm are used as samples to experimentally demonstrate the effectiveness of our technique.展开更多
Postoperative venous thromboembolism(VTE)in colorectal cancer(CRC)patients undergoing surgery results in poor prognosis.However,there are no effective tools for early screening and predicting VTE.In this study,we deve...Postoperative venous thromboembolism(VTE)in colorectal cancer(CRC)patients undergoing surgery results in poor prognosis.However,there are no effective tools for early screening and predicting VTE.In this study,we developed a machine learning(ML)-based model for predicting the risk of VTE following CRC surgery and tested its performance using an external dataset.A total of 3227 CRC surgery patients were enrolled from the Affiliated Hospital of Qingdao University and Yantai Yuhuangding Hospital(from January 2016 to December 2023).Subsequently,1596 patients from the Affiliated Hospital of Qingdao University were assigned to the training set,and 716 patients from Yantai Yuhuangding Hospital were assigned to the external validation set.A model was developed and trained using six ML algorithms using the stacking ensemble technique.Moreover,all models were developed using the tenfold cross-validation on the training set,and their performance was tested using an independent external validation set.In the training set,173(10.8%)patients developed VTE,163(10.2%)patients experienced deep venous thrombosis,and 29(1.82%)cases had pulmonary embolism(PE).In the external validation set,85(11.9%)cases of VTE,83(11.6%)cases of deep vein thrombosis,and 14(1.96%)cases of PE were recorded.The analysis revealed that the stacking model outperformed all other models in the external validation set,achieving significantly better performance in all metrics:the area under the receiver operating characteristic curve=0.840(0.790–0.887),accuracy=0.810(0.783–0.836),specificity=0.819(0.790–0.848),sensitivity=0.741(0.652–0.825),and recall=0.959(0.942–0.975).The stacking model for surgical CRC patients shows promise in enabling timely clinical detection of high-risk cases.This method facilitates the prioritized implementation of prophylactic anticoagulation in confirmed high-risk individuals,thereby mitigating unnecessary pharmacological intervention in low-risk populations.展开更多
This paper carries out a game-theoretic analysis of a single-server queueing system with setup times under N-policy by considering both the partially observable and the partially unobservable information scenarios. Th...This paper carries out a game-theoretic analysis of a single-server queueing system with setup times under N-policy by considering both the partially observable and the partially unobservable information scenarios. The server switches off whenever the system becomes empty, and is resumed when the number of customers reaches a certain threshold value. Customers decide whether to join or to balk the system upon arrival based on their available information. The equilibrium joining strategy of customers as well as the systemzs performance measures are derived under different information levels. We find that both Follow-the-Crowd (FTC) and Avoid-the-Crowd (ATC) behaviors exist in our system. Numerical results show that the social welfare is unimodal in the threshold, and is decreasing in the waiting cost.展开更多
Multi-agent reinforcement learning is difficult to apply in practice,partially because of the gap between simulated and real-world scenarios.One reason for the gap is that simulated systems always assume that agents c...Multi-agent reinforcement learning is difficult to apply in practice,partially because of the gap between simulated and real-world scenarios.One reason for the gap is that simulated systems always assume that agents can work normally all the time,while in practice,one or more agents may unexpectedly“crash”during the coordination process due to inevitable hardware or software failures.Such crashes destroy the cooperation among agents and lead to performance degradation.In this work,we present a formal conceptualization of a cooperative multi-agent reinforcement learning system with unexpected crashes.To enhance the robustness of the system to crashes,we propose a coach-assisted multi-agent reinforcement learning framework that introduces a virtual coach agent to adjust the crash rate during training.We have designed three coaching strategies(fixed crash rate,curriculum learning,and adaptive crash rate)and a re-sampling strategy for our coach agent.To our knowledge,this work is the first to study unexpected crashes in a multi-agent system.Extensive experiments on grid-world and StarCraft II micromanagement tasks demonstrate the efficacy of the adaptive strategy compared with the fixed crash rate strategy and curriculum learning strategy.The ablation study further illustrates the effectiveness of our re-sampling strategy.展开更多
The article“Equilibrium Joining Strategies in the M/M/1 Queues with Setup Times under N-Policy”unfortunately contained a mistake about the first author’s affiliation.In the original publication of the paper,this af...The article“Equilibrium Joining Strategies in the M/M/1 Queues with Setup Times under N-Policy”unfortunately contained a mistake about the first author’s affiliation.In the original publication of the paper,this affiliation was“Department of Mathematics,Beijing Jiaotong University,Beijing 100044,China”.It should be“School of Economics and Management,University of Chinese Academy of Sciences,Beijing,100190,China”.展开更多
Photocrosslinkable polymers have been exploited to attain impressive advantages in printing freestanding,micrometer-scale,mechanically compliant features.However,a more integrated understanding of both the polymer pho...Photocrosslinkable polymers have been exploited to attain impressive advantages in printing freestanding,micrometer-scale,mechanically compliant features.However,a more integrated understanding of both the polymer photochemistry and the microfabrication processes could enable new strategic design avenues,unlocking far-reaching applications of the light-based modality of additive manufacturing.One promising approach for achieving high-aspect-ratio structures is to leverage the phenomenon of light self-trapping during the photopolymerization process.In this review,we discuss the design of materials that facilitate this optical behavior,the computational modeling and practical processing considerations to achieve high aspect-ratio structures,and the range of applications that can benefit from architectures fabricated using light self-trapping-especially those demanding free-standing structures and materials of stiffnesses relevant in biological applications.Coupled interactions exist among material attributes,including polymer composition,and processing parameters such as light intensity.We identify strong opportunities for predictive design of both the material and the process.Overall,this perspective describes the wide range of existing polymers and additive manufacturing approaches,and highlights various future directions to enable constructs with new complexities and functionalities through the development of next-generation photocrosslinkable materials and micromanufacturing methods.展开更多
基金supported by the National Natural Science Foundation of China(22305238)the Anhui Provincial Natural Science Foundation(2308085MB35)。
文摘The utilization of covalent organic frameworks(COFs)holds great potential for achieving tailorable tuning of catalytic performance through bottom-up modulation of the reticular structure.In this work,we show that a single-point structural alteration in the linkage within a nickel phthalocyanine(NiPc)-based series effectively modulates the catalytic performance of the COFs in electrochemical CO_(2)reduction reaction(CO_(2)RR).A Ni Pc-based COF series with three members which possess the same Ni Pc unit but different linkages,including piperazine,dioxin,and dithiine,have been constructed by nucleophilic aromatic substitution reaction between octafluorophthalocyanine nickel and tetrasubstituted benzene linkers with different bridging groups.Among these COFs,the dioxin-linked COF showed the best activity of CO_(2)RR with a current density of CO(j_(CO))=-27.99 m A cm^(-2)at-1.0 V(versus reversible hydrogen electrode,RHE),while the COF with piperazine linkage demonstrated an excellent selectivity of Faradaic efficiency for CO(FECO)up to 90.7%at a pretty low overpotential of 0.39 V.In addition,both a high FECO value close to 100%and a reasonable jCO of-8.20 m A cm^(-2)at the potential of-0.8 V(versus RHE)were obtained by the piperazine-linked COF,making it one of the most competitive candidates among COF-based materials.Mechanistic studies exhibited that single-point structural alteration could tailor the electron density in Ni sites and alter the interaction between the active sites and the key intermediates adsorbed and desorbed,thereby tuning the electrochemical performance during CO_(2)RR process.
基金supported by the National Natural Science Foundation of China(22305238,22475203)Anhui Provincial Natural Science Foundation(2308085MB35)the Innovation Program for Quantum Science and Technology(2021zD0303303).
文摘Two-dimensional conductive metal-organic frameworks(2D c-MOFs),constructed by coordination between metal ions andπ-conjugated ligands,represent a unique class of materials that combine intrinsic porosity and electrical conductivity.However,the contribution of metal nodes to the overall electrical properties remains unclear.In this work,we systematically investigate the role of metal centers on a series of six highly crystalline hexahydroxytriphenylene(HHTP)based c-MOFs,M-HHTP,which incorporate alkaline earth including magnesium and calcium,as well as transition metals including cobalt,nickel,copper,and zinc.Comprehensive structural characterizations reveal that while all M-HHTP frameworks adopt a general honeycomb lattice,however,subtle variations in stacking patterns and coordination environments are induced by different metal ions.Electrical measurements show a pronounced dependence of conductivity on the nature of the metal nodes,in which the conductivity differs by four orders of magnitude due to the difference in metal centers.Furthermore,non-contact terahertz spectroscopy combined with theoretical calculations suggests that in alkaline earth metal-based MOFs,charge transport may proceed via a through-space hopping mechanism between organic ligands.This study elucidates the critical role of metal centers in governing charge transport in M-HHTP MOFs and offers valuable guidance for the rational design of high-performance 2D conductive frameworks.
基金supported by the National Natural Science Foundation of China(12025503,U23B2072,12305329)the China Postdoctoral Science Foundation(2024T170683)the Hubei Provincial Natural Science Foundation(2023AFB236)。
文摘Electrochemical water splitting is considered to be the most promising hydrogen production technology,but the sluggish kinetics and high energy consumption in the anodic oxygen evolution reaction limit the large-scale deployment of the technology.Coupling energy-efficient electrooxidation of biomassderived glycerol and cathodic hydrogen evolution reaction provides a promising strategy for improving the techno-economics of the water electrolysis technology.Herein,by dispersing transition metal elements with weak d-p coupling strength into the MnO_(2)lattice,the fine tuning of the bioctahedral d-p orbital in MnO_(2)is successfully realized,which greatly accelerates the hydrogen transfer in glycerol oxidation.In-situ Raman results confirmed that Ni–MnO_(2)could spontaneously activate glycerol molecules and drive hydrogen transfer to lattice oxygen sites,leading to the occurrence of successive phase transitions(α-MnO_(2)→Mn_(3)O_(4)→MnOOH).Density functional theory(DFT)calculations revealed that the incorporation of Ni broadened the d-orbital and regulated the distribution of p-orbitals near the oxygen Fermi level in the lattice,resulting in a relatively high empty orbital state to facilitate the hydrogen transfer process.The optimal Ni–MnO_(2)delivered a low potential of 1.16 V vs.RHE to reach 10 mA cm^(-2),a high FE of 99.7%for formate,and superior durability over 80 h.This work provides new insights into balancing the adsorption and activation of biomass molecules while casting a universal strategy for developing efficient biomass oxidation electrocatalysts.
基金supported in part by the State Grid Corporation of China(SGCC)“Research on the Sand-table Deduction and Risk Decision-making Technology of the Power System Actively Supporting the Energy Transition and Dual-carbon Revolution”(No.524608220268)。
文摘Planning the low-carbon transition pathway of the power sector to meet the carbon neutrality goal poses a significant challenge due to the complex interplay of temporal,spatial,and cross-domain factors.A novel framework is proposed,grounded in the cyber-physical-social system in energy(CPSSE)and whole-reductionism thinking(WRT),incorporating a tailored mathematical model and optimization method to formalize the co-optimization of carbon reduction and carbon sequestration in the power sector.Using the carbon peaking and carbon neutrality transition of China as a case study,clustering method is employed to construct a diverse set of strategically distinct carbon trajectories.For each trajectory,the evolution of the generation mix and the deployment pathways of carbon capture and storage(CCS)technologies are analyzed,identifying the optimal transition pathway based on the criterion of minimizing cumulative economic costs.Further,by comparing non-fossil energy substitution and CCS retrofitting in thermal power,the analysis highlights the potential for co-optimization of carbon reduction and carbon sequestration.The results demonstrate that leveraging the spatiotemporal complementarities between the two can substantially lower the economic cost of achieving carbon neutrality,providing insights for integrated decarbonization strategies in power system planning.
文摘Correction:aBIOTECH https://doi.org/10.1007/s42994-025-00214-7 The original article contained several errors caused in the production process of the article:In this article the affiliation‘State Key Laboratory of Seed Innovation,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing,100101,China’for Author Jia Yuan was missing.Greek letters and other symbols were missing in Figs.1 and 4 have now been included.
基金supported by National Natural Science Foundation of China(32470265)to GDW.
文摘Plant specialized metabolites are commonly stored in glycosylated forms within plant cells,with their homeostasis regulated by glycosyltransferases andβ-glucosidases(BGLUs,also known asβ-glucoside hydrolases(E.C.3.2.1.21)).Soyasaponins,the predominant triterpenoid compounds(C30)in soybean seeds,contain two sugar moieties attached at the C3 and C22 positions.While glycosyltransferases involved in soyasaponin biosynthesis have been well characterized,the role of BGLUs in soyasaponin homeostasis remains unclear.In this study,we identified GmSSBG1(Soyasaponinβ-glucosidase1;Glyma.07G258700)as a candidate gene potentially involved in soyasaponin homeostasis through gene to gene co-expression analysis.Biochemical assays demonstrated that GmSSBG1 specifically hydrolyzes arabinose residues at the C22 position of A0-and B0-series soyasaponins.Loss-of-function mutations in GmSSBG1 led to a significant accumulation of A0-and B0-series soyasaponins in mutant seeds,which correlated with a pronounced decrease in resistance to the soybean pod borer(Leguminivora glycinivorella).Our findings provide critical insights into the regulatory mechanisms underlying soyasaponin homeostasis and lay a theoretical foundation for molecular breeding strategies aimed at developing soybean lines with enhanced resistance to soybean pod borer,even to other insect pests.
文摘As generative AI is increasingly integrated into emotionally intimate contexts,concerns about its reproduction of gender bias are growing.While existing scholarship has extensively explored static biases in dataset and model design,few studies have explored how gender stereotypes evolve and are reinforced through dynamic human-computer interactions.This study examines how emotionally sustained conversations with an AI agent(e.g.,ChatGPT)gradually stabilize and amplify symbolic gender roles through ritualized discourse patterns.Drawing on the Computers as Social Actors(CASA)paradigm and Interactive Ritual Chaining(IRC)theory,this study explores how users co-construct relational expectations with AI systems over time.Using a two-stage corpus design containing eight participants,we compared lexical frames and emotional tones in the preand post-phases of intimate interaction.Results suggest that the AI’s responses increasingly conformed to normative gender roles:women were positioned as emotional receivers,while men were shaped as resilience providers-even when expressing similar emotional needs.These findings highlight that dynamic biases are not only deeply ingrained,but also reinforced by the way they are interacted with,creating new ethical challenges for relational fairness in AI communication.By shifting the focus from static design issues to ongoing dialogic reproduction of gender meaning,this study contributes to a deeper understanding of algorithmic bias in virtual companionship.
基金supported by the National Natural Science Foundation of China(No.62205156)。
文摘Tail artifacts are a significant issue in optical coherence tomography angiography[OCTA],as they cast shadows over underlying signals and interfere with the reconstruction of 3D vessel images.While many methods have been developed to reduce these artifacts,most only shorten the tails and fail to clearly distinguish between vessels and artifacts.In this Letter,we present an image processing technique designed to reduce artifacts.By combining structural images with OCTA images,we can more effectively distinguish between vessels and artifacts,leading to shorter and less pronounced tail artifacts.This method is integrated with other tail artifact removal techniques to further enhance image quality.The vessels of the palm are used as samples to experimentally demonstrate the effectiveness of our technique.
文摘Postoperative venous thromboembolism(VTE)in colorectal cancer(CRC)patients undergoing surgery results in poor prognosis.However,there are no effective tools for early screening and predicting VTE.In this study,we developed a machine learning(ML)-based model for predicting the risk of VTE following CRC surgery and tested its performance using an external dataset.A total of 3227 CRC surgery patients were enrolled from the Affiliated Hospital of Qingdao University and Yantai Yuhuangding Hospital(from January 2016 to December 2023).Subsequently,1596 patients from the Affiliated Hospital of Qingdao University were assigned to the training set,and 716 patients from Yantai Yuhuangding Hospital were assigned to the external validation set.A model was developed and trained using six ML algorithms using the stacking ensemble technique.Moreover,all models were developed using the tenfold cross-validation on the training set,and their performance was tested using an independent external validation set.In the training set,173(10.8%)patients developed VTE,163(10.2%)patients experienced deep venous thrombosis,and 29(1.82%)cases had pulmonary embolism(PE).In the external validation set,85(11.9%)cases of VTE,83(11.6%)cases of deep vein thrombosis,and 14(1.96%)cases of PE were recorded.The analysis revealed that the stacking model outperformed all other models in the external validation set,achieving significantly better performance in all metrics:the area under the receiver operating characteristic curve=0.840(0.790–0.887),accuracy=0.810(0.783–0.836),specificity=0.819(0.790–0.848),sensitivity=0.741(0.652–0.825),and recall=0.959(0.942–0.975).The stacking model for surgical CRC patients shows promise in enabling timely clinical detection of high-risk cases.This method facilitates the prioritized implementation of prophylactic anticoagulation in confirmed high-risk individuals,thereby mitigating unnecessary pharmacological intervention in low-risk populations.
基金the National Natural Science Foundation of China under Grant Nos.71871008 and 71571014.
文摘This paper carries out a game-theoretic analysis of a single-server queueing system with setup times under N-policy by considering both the partially observable and the partially unobservable information scenarios. The server switches off whenever the system becomes empty, and is resumed when the number of customers reaches a certain threshold value. Customers decide whether to join or to balk the system upon arrival based on their available information. The equilibrium joining strategy of customers as well as the systemzs performance measures are derived under different information levels. We find that both Follow-the-Crowd (FTC) and Avoid-the-Crowd (ATC) behaviors exist in our system. Numerical results show that the social welfare is unimodal in the threshold, and is decreasing in the waiting cost.
基金Project supported by the National Natural Science Foundation of China(No.61836011)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2018497)the GPU cluster built by the MCC Lab of Information Science and Technology Institution,USTC,China。
文摘Multi-agent reinforcement learning is difficult to apply in practice,partially because of the gap between simulated and real-world scenarios.One reason for the gap is that simulated systems always assume that agents can work normally all the time,while in practice,one or more agents may unexpectedly“crash”during the coordination process due to inevitable hardware or software failures.Such crashes destroy the cooperation among agents and lead to performance degradation.In this work,we present a formal conceptualization of a cooperative multi-agent reinforcement learning system with unexpected crashes.To enhance the robustness of the system to crashes,we propose a coach-assisted multi-agent reinforcement learning framework that introduces a virtual coach agent to adjust the crash rate during training.We have designed three coaching strategies(fixed crash rate,curriculum learning,and adaptive crash rate)and a re-sampling strategy for our coach agent.To our knowledge,this work is the first to study unexpected crashes in a multi-agent system.Extensive experiments on grid-world and StarCraft II micromanagement tasks demonstrate the efficacy of the adaptive strategy compared with the fixed crash rate strategy and curriculum learning strategy.The ablation study further illustrates the effectiveness of our re-sampling strategy.
文摘The article“Equilibrium Joining Strategies in the M/M/1 Queues with Setup Times under N-Policy”unfortunately contained a mistake about the first author’s affiliation.In the original publication of the paper,this affiliation was“Department of Mathematics,Beijing Jiaotong University,Beijing 100044,China”.It should be“School of Economics and Management,University of Chinese Academy of Sciences,Beijing,100190,China”.
基金M.Y.acknowledges the Angela Leong Fellowship Fund 2021-2022 from the Massachusetts Institute of Technology.K.K.acknowledges the financial support of the Natural Sciences and Engineering Research Council of Canada(award no.PDF-529703-2019)S.K.acknowledges the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2019R1A5A8083201 and 2022R1C1C1003966)。
文摘Photocrosslinkable polymers have been exploited to attain impressive advantages in printing freestanding,micrometer-scale,mechanically compliant features.However,a more integrated understanding of both the polymer photochemistry and the microfabrication processes could enable new strategic design avenues,unlocking far-reaching applications of the light-based modality of additive manufacturing.One promising approach for achieving high-aspect-ratio structures is to leverage the phenomenon of light self-trapping during the photopolymerization process.In this review,we discuss the design of materials that facilitate this optical behavior,the computational modeling and practical processing considerations to achieve high aspect-ratio structures,and the range of applications that can benefit from architectures fabricated using light self-trapping-especially those demanding free-standing structures and materials of stiffnesses relevant in biological applications.Coupled interactions exist among material attributes,including polymer composition,and processing parameters such as light intensity.We identify strong opportunities for predictive design of both the material and the process.Overall,this perspective describes the wide range of existing polymers and additive manufacturing approaches,and highlights various future directions to enable constructs with new complexities and functionalities through the development of next-generation photocrosslinkable materials and micromanufacturing methods.
