Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a ca...Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a cancer-associated fibroblasts(CAFs)triggered structure-transformable nano-assembly(HSD-P@V),which can directionally deliver valsartan(Val,CAFs regulator)and doxorubicin(DOX,senescence inducer)to the specific targets.In detail,DOX is conjugated with hyaluronic acid(HA)via diselenide bonds(Se-Se)to form HSD micelles,while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer,which is coated on Val nanocrystals(VNs)surface for improving the stability and achieving responsive release.Once arriving at tumor microenvironment and touching CAFs,HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment.VNs can degrade the extracellularmatrix,leading to the enhanced penetration of HSD.HSD targets tumor cells,releases DOX to induce senescence,and recruits effector immune cells.Furthermore,senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy.In vitro and in vivo results show that the nanoassembly remarkably inhibits tumor growth as well as lungmetastasis,and extends tumorbearing mice survival.This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.展开更多
The introduction of alleles into commercial crop breeding pipelines is both time consuming and costly.Two technologies that are disrupting traditional breeding processes are doubled haploid(DH)breeding and genome edit...The introduction of alleles into commercial crop breeding pipelines is both time consuming and costly.Two technologies that are disrupting traditional breeding processes are doubled haploid(DH)breeding and genome editing(GE).Recently,these techniques were combined into a GE trait delivery system called HI-Edit(Haploid Inducer-Edit).In HI-Edit,the pollen of a haploid inducer line is reprogrammed to deliver GE traits to any variety,obviating recurrent selection.For HI-Edit to operate at scale,an efficient transformable HI line is needed,but most maize varieties are recalcitrant to transformation,and haploid inducers are especially difficult to transform given their aberrant reproductive behaviors.Leveraging marker assisted selection and a three-tiered testing scheme,we report the development of new Iodent and Stiff Stalk maize germplasm that are transformable,have high haploid induction rates,and exhibit a robust,genetically-dominant anthocyanin native trait that may be used for rapid haploid identification.We show that transformation of these elite‘‘HI-Edit”lines is enhanced using the BABYBOOM and WUSCHEL morphogenetic factors.Finally,we evaluate the HI-Edit performance of one of the lines against both Stiff Stalk and non-Stiff Stalk testers.The strategy and results of this study should facilitate the development of commercially scalable HI-Edit systems in diverse crops.展开更多
In recent years,various transformable nanoparticles（NPs）were successfully prepared and widely utilized for biomedical applications.The sizes,surface charges or morphologies of transformable NPs would affect their be...In recent years,various transformable nanoparticles（NPs）were successfully prepared and widely utilized for biomedical applications.The sizes,surface charges or morphologies of transformable NPs would affect their behavior in physiological/pathological conditions including circulation,penetration,accumulation and retention etc.The other way round,the NPs could be precisely modulated in the specific physiological/pathological condition for precision theranostics of diseases.Herein,we summarized recent advances of transformable NPs for disease diagnostics and therapy.In this review,the transformation of NPs was divided into three groups including changes in size,surface charge and morphology,which was induced by internal stimuli,such as p H,enzyme,receptor or external stimuli,such as light,temperature etc.Moreover,we focused on the characterization of structural transformation in vivo,as well as the transformation-induced biological effects for theranostics of disease.展开更多
The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environ...The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environmental conditions and meet different functions. This can help in reducing environmental waste and pollution associated with many buildings and above all can save on cost and time. Natural systems have inspired human being, since they began to build and design. Architects and designers have utilized nature as one of the main resources of information for the creation of innovative architectural spaces. One of the unique features of natural structures is the way that their components open and close in order to respond to a particular requirement or the environmental changes. This aspect has inspired many designers for the development of transformable architectural structures that can change their shape and geometry to be able to adapt with specific conditions. To make a way toward the design of transformable structure for temporary applications, the authors have developed a new type of adaptable structures according to natural forms. The proposed design applies the transformation principles that exist in potato＇s flower and the movement mechanisms used in a spider＇s leg. The design is able to fit to different topographies and have a potential to be folded to a very compact state in a very short period of time. The detailed design and the different configurations of the system applications will be presented in this paper. The result of the study shows that using modular triangular plates can create a changeable module that is not only able to respond to different functions and environmental changes but it is also able to shape different configuration to be able to respond to different user＇s ambitions. The compactability of this structure into 1/3 of its base dimensions; makes its transportation fast and with minimum costs. These capabilities make this structure suitable for temporary buildings such as exhibitions, temporary settlements or hospital in damaged areas.展开更多
Transformable architecture is totally linked to the study and knowledge of geometry.There are some materials in nature,whose geometric invariants establish equivalent structural behavior regarding the scalar transform...Transformable architecture is totally linked to the study and knowledge of geometry.There are some materials in nature,whose geometric invariants establish equivalent structural behavior regarding the scalar transformations,developing different spatial typologies according to dimensional variation.Auxetic materials are characterized by their negative Poisson’s ratio.They can change their geometric configuration from a line to a surface,and from a surface to a volume or spatial framework.This paper is based on establishing and comparing those stellated reentrant auxetic geometries to be able to build new spaces defined by their capacity for architectural transformation,studying analytically geometric properties of stellated reentrant auxetic structures that,from the molecular to the macroscopic level,can be part of the architecture construction.In this investigation,a comparative study by means of CAD of stellated reentrant auxetic patterns has been realized.A Computer-Aided Design study of stellated reentrant auxetic structures will be realized to use them in architecture.The geometric behavior of the different stellated reentrant auxetic patterns is analyzed from the developed study to generate a systematic comparison,evaluating properties of these forms,such as their maximum achievable area reductions in relation to the total length of bars of the structure,in order to obtain a growth factor.展开更多
The structural change-mediated catalytic activity regulation plays a significant role in the biological functions of natural enzymes.However,there is virtually no artificial nanozyme reported that can achieve natural ...The structural change-mediated catalytic activity regulation plays a significant role in the biological functions of natural enzymes.However,there is virtually no artificial nanozyme reported that can achieve natural enzyme-like stringent spatiotemporal structure-based catalytic activity regulation.Here,we report a subnanostructural transformable gold@ceria(STGC-PEG)nanozyme that performs tunable catalytic activities via near-infrared(NIR)light-mediated sub-nanostructural transformation.The gold core in STGC-PEG can generate energetic hot electrons upon NIR irradiation,wherein an internal sub-nanostructural transformation is initiated by the conversion between CeO;and electron-rich state of CeO;-x,and active oxygen vacancies generation via the hot-electron injection.Interestingly,the sub-nanostructural transformation of STGC-PEG enhances peroxidase-like activity and unprecedentedly activates plasmon-promoted oxidase-like activity,allowing highly efficient low-power NIR light(50 m W cm;)-activated photocatalytic therapy of tumors.Our atomic-level design and fabrication provide a platform to precisely regulate the catalytic activities of nanozymes via a light-mediated sub-nanostructural transformation,approaching natural enzyme-like activity control in complex living systems.展开更多
Developing bulk metallic glass composites(BMGCs)with high toughness is vital for their practical application.However,the influence of different microstructures on the impact toughness of BMGCs is still unclear.The eff...Developing bulk metallic glass composites(BMGCs)with high toughness is vital for their practical application.However,the influence of different microstructures on the impact toughness of BMGCs is still unclear.The effects of Al addition and cryogenic cyclic treatment(CCT)on the Charpy impact toughness,a K,at 298 and 77 K of a series of phase-transformable BMGCs are investigated in this work.It is found that deformation-induced martensitic transformation(DIMT)of theβ-Ti dendrites is the dominant toughening mechanism in the phase-transformable BMGCs at 298 K,but at 77 K,the toughness of BMGCs is primarily determined by the intrinsic toughness of the glass matrix.The addition of Al can moderately tune theβ-Ti phase stability,which then affects the amount of DIMT and impact toughness of the BMGCs at 298 K.However,at 77 K,Al addition causes a monotonic decrease in the toughness of the BMGCs due to the embrittlement of the glass matrix.It is found that CCT can effectively rejuvenate the phase-transformable BMGCs,which results in an enhanced impact toughness at 298 K.However,the toughness at 77 K monotonously decreases with increasing the number of CCT cycles,suggesting that the rejuvenation of the glass matrix affects the toughness at both 298 and 77 K of BMGCs,but in dramatically different ways.These findings reveal the influence of microstructures and CCT on the impact toughness of BMGCs and provide insights that could be useful for designing tougher BMGs and BMGCs.展开更多
The solar sail is one of the most promising space exploration systems due to its theoretically infinite specific impulse achieved through solar radiation pressure(SRP).Recently,researchers have proposed“transformable...The solar sail is one of the most promising space exploration systems due to its theoretically infinite specific impulse achieved through solar radiation pressure(SRP).Recently,researchers have proposed“transformable spacecraft”capable of actively reconfiguring their body configurations using actuatable joints.Transformable spacecraft,if used similarly to solar sails,are expected to significantly enhance orbit and attitude control capabilities owing to their high redundancy in control degrees of freedom.However,controlling them becomes challenging due to their large number of inputs,leading previous researchers to impose strong constraints to limit their potential control capabilities.This study focuses on novel attitude control techniques for transformable spacecraft under SRP.We developed two methods,namely,joint angle optimization to obtain arbitrary SRP force and torque,and momentum damping control driven by joint angle actuation.Our proposed methods are formulated in a general manner and can be applied to any transformable spacecraft comprising front faces that can predominantly receive the SRP on each body.The validity of our proposed method is confirmed through numerical simulations.Our study contributes to making most of the high control redundancy of transformable spacecraft without the need for expendable propellants,thus significantly enhancing the orbit and attitude control capabilities.展开更多
Tumor microenvironment activatable therapeutic agents and their effective tumor accumula-tion are significant for selective tumor treatment.Herein,we provide an unadulterated nanomaterial combining the above advantage...Tumor microenvironment activatable therapeutic agents and their effective tumor accumula-tion are significant for selective tumor treatment.Herein,we provide an unadulterated nanomaterial combining the above advantages.We synthesize a perylene diimide(PDI)molecule substituted by glu-tamic acid(Glu),which can self-assemble into small spherical nanoparticles(PDI-SG)in aqueous solu-tion.PDI-SG can not only be transformed into nanofibers at low pH conditions but also be reduced to PDI radical anion(PDI^(·-)),which exhibits strong near-infrared absorption and excellent photothermal perfor-mance.More importantly,PDI-SG can also be reduced to PDI^(·-)in hypoxic tumors to ablate the tumors and minimize the damage to normal tissues.The morphological transformation from small nanoparticles to nanofibers makes for better tumor accumulation and retention.This work sheds light on the design of tumor microenvironment activatable therapeutics with precise structures for high-performance tumor therapy.展开更多
Developing an oral in situ-forming hydrogel that targets the inflamed intestine to suppress bleeding ulcers and alleviate intestinal inflammation is crucial for effectively treating ulcerative colitis(UC).Here,inspire...Developing an oral in situ-forming hydrogel that targets the inflamed intestine to suppress bleeding ulcers and alleviate intestinal inflammation is crucial for effectively treating ulcerative colitis(UC).Here,inspired by sandcastle worm adhesives,we proposed a water-immiscible coacervate(EMNs-gel)with a programmed coacervate-to-hydrogel transition at inflammatory sites composed of dopa-rich silk fibroin matrix containing embedded inflammation-responsive core-shell nanoparticles.Driven by intestinal peristalsis,the EMNs-gel can be actuated forward and immediately transform into a hydrogel once contacting with the inflamed intestine to yield strong tissue adhesion,resulting from matrix metalloproteinases(MMPs)-triggered release of Fe3+from embedded nanoparticles and rearrangement of polymer network of EMNs-gel on inflamed intestine surfaces.Extensive in vitro experiments and in vivo UC models confirmed the preferential hydrogelation behavior of EMNs-gel to inflamed intestine surfaces,achieving highly effective hemostasis,and displaying an extended residence time(48 h).This innovative EMNs-gel provides a non-invasive solution that accurately suppresses severe bleeding and improves intestinal homeostasis in UC,showcasing great potential for clinical applications.展开更多
为解决风电机组故障诊断中故障样本不足而导致模型准确率不高的问题,将当下备受关注的数据增强方法-去噪扩散概率模型(denoising diffusion probability model,DDPM)引入到故障诊断领域以生成大量高质量的故障样本数据集。因此,结合Tran...为解决风电机组故障诊断中故障样本不足而导致模型准确率不高的问题,将当下备受关注的数据增强方法-去噪扩散概率模型(denoising diffusion probability model,DDPM)引入到故障诊断领域以生成大量高质量的故障样本数据集。因此,结合Transformer网络,提出了一种DDPM-Transformer风电机组故障样本生成方法。首先,将用于计算机视觉图像生成领域的DDPM模型应用于风电机组故障诊断领域中,通过前向加噪过程将数据逐渐转化为噪声,再通过逆向去噪过程将噪声逐步恢复为原始数据,实现从噪声中生成故障数据,解决数据不平衡问题;其次,通过对原始DDPM中使用的U-net模块进行改进,使用Transformer模型替换U-net网络,利用扩散后的数据和添加的噪声训练Transformer模型,实现噪声预测,以提高故障数据的生成质量;最后,使用多种生成模型评价指标对生成的故障数据进行评价,在监督控制和数据采集系统(supervisory control and data acquisition,SCADA)故障数据生成中论证改进DDPM-Transformer模型的性能。通过试验证明,所提DDPM-Transformer模型与现有的生成模型相比,最大均值异(maximum mean discrepancy,MMD)最大提升0.13,峰值信噪比(peak signal to noise ratio,PSNR)最大提升7.8。所提模型可以有效地生成质量更高的风电机组故障样本,从而基于该样本集辅助训练基于深度学习的故障诊断模型,可以使诊断模型具有更高精度和良好的稳定性。展开更多
深度学习是人工智能领域的热门研究方向之一,它通过构建多层人工神经网络模仿人脑对数据的处理机制。大型语言模型(large language model,LLM)基于深度学习的架构,在无需编程指令的情况下,能通过分析大量数据以获得理解和生成人类语言...深度学习是人工智能领域的热门研究方向之一,它通过构建多层人工神经网络模仿人脑对数据的处理机制。大型语言模型(large language model,LLM)基于深度学习的架构,在无需编程指令的情况下,能通过分析大量数据以获得理解和生成人类语言的能力,被广泛应用于自然语言处理、计算机视觉、智慧医疗、智慧交通等诸多领域。文章总结了LLM在医疗领域的应用,涵盖了LLM针对医疗任务的基本训练流程、特殊策略以及在具体医疗场景中的应用。同时,进一步讨论了LLM在应用中面临的挑战,包括决策过程缺乏透明度、输出准确性以及隐私、伦理问题等,随后列举了相应的改进策略。最后,文章展望了LLM在医疗领域的未来发展趋势,及其对人类健康事业发展的潜在影响。展开更多
基金was supported by National Natural Science Foundation of China(81972893,82172719)Natural Science Foundation of Henan(212300410071)Training program for young key teachers in Henan Province(2020GGJS019).
文摘Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy,but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration.Herein,we designed a cancer-associated fibroblasts(CAFs)triggered structure-transformable nano-assembly(HSD-P@V),which can directionally deliver valsartan(Val,CAFs regulator)and doxorubicin(DOX,senescence inducer)to the specific targets.In detail,DOX is conjugated with hyaluronic acid(HA)via diselenide bonds(Se-Se)to form HSD micelles,while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer,which is coated on Val nanocrystals(VNs)surface for improving the stability and achieving responsive release.Once arriving at tumor microenvironment and touching CAFs,HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment.VNs can degrade the extracellularmatrix,leading to the enhanced penetration of HSD.HSD targets tumor cells,releases DOX to induce senescence,and recruits effector immune cells.Furthermore,senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy.In vitro and in vivo results show that the nanoassembly remarkably inhibits tumor growth as well as lungmetastasis,and extends tumorbearing mice survival.This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.
文摘The introduction of alleles into commercial crop breeding pipelines is both time consuming and costly.Two technologies that are disrupting traditional breeding processes are doubled haploid(DH)breeding and genome editing(GE).Recently,these techniques were combined into a GE trait delivery system called HI-Edit(Haploid Inducer-Edit).In HI-Edit,the pollen of a haploid inducer line is reprogrammed to deliver GE traits to any variety,obviating recurrent selection.For HI-Edit to operate at scale,an efficient transformable HI line is needed,but most maize varieties are recalcitrant to transformation,and haploid inducers are especially difficult to transform given their aberrant reproductive behaviors.Leveraging marker assisted selection and a three-tiered testing scheme,we report the development of new Iodent and Stiff Stalk maize germplasm that are transformable,have high haploid induction rates,and exhibit a robust,genetically-dominant anthocyanin native trait that may be used for rapid haploid identification.We show that transformation of these elite‘‘HI-Edit”lines is enhanced using the BABYBOOM and WUSCHEL morphogenetic factors.Finally,we evaluate the HI-Edit performance of one of the lines against both Stiff Stalk and non-Stiff Stalk testers.The strategy and results of this study should facilitate the development of commercially scalable HI-Edit systems in diverse crops.
基金supported by the National Natural Science Foundation of China(Nos.51573031,21373726,21303723,21603028 and 21573036)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.11621505)+1 种基金CAS Key Research Program for Frontier Sciences(No.QYZDJ-SSW-SLH022)Key Project of Chinese Academy of Sciences in Cooperation with Foreign Enterprises(No.GJHZ1541)
文摘In recent years,various transformable nanoparticles（NPs）were successfully prepared and widely utilized for biomedical applications.The sizes,surface charges or morphologies of transformable NPs would affect their behavior in physiological/pathological conditions including circulation,penetration,accumulation and retention etc.The other way round,the NPs could be precisely modulated in the specific physiological/pathological condition for precision theranostics of diseases.Herein,we summarized recent advances of transformable NPs for disease diagnostics and therapy.In this review,the transformation of NPs was divided into three groups including changes in size,surface charge and morphology,which was induced by internal stimuli,such as p H,enzyme,receptor or external stimuli,such as light,temperature etc.Moreover,we focused on the characterization of structural transformation in vivo,as well as the transformation-induced biological effects for theranostics of disease.
文摘The contemplation of contemporary architectural designs shows an increasing demand for the development of more adaptable, flexible and transformable structures. This type of structures can adapt with different environmental conditions and meet different functions. This can help in reducing environmental waste and pollution associated with many buildings and above all can save on cost and time. Natural systems have inspired human being, since they began to build and design. Architects and designers have utilized nature as one of the main resources of information for the creation of innovative architectural spaces. One of the unique features of natural structures is the way that their components open and close in order to respond to a particular requirement or the environmental changes. This aspect has inspired many designers for the development of transformable architectural structures that can change their shape and geometry to be able to adapt with specific conditions. To make a way toward the design of transformable structure for temporary applications, the authors have developed a new type of adaptable structures according to natural forms. The proposed design applies the transformation principles that exist in potato＇s flower and the movement mechanisms used in a spider＇s leg. The design is able to fit to different topographies and have a potential to be folded to a very compact state in a very short period of time. The detailed design and the different configurations of the system applications will be presented in this paper. The result of the study shows that using modular triangular plates can create a changeable module that is not only able to respond to different functions and environmental changes but it is also able to shape different configuration to be able to respond to different user＇s ambitions. The compactability of this structure into 1/3 of its base dimensions; makes its transportation fast and with minimum costs. These capabilities make this structure suitable for temporary buildings such as exhibitions, temporary settlements or hospital in damaged areas.
文摘Transformable architecture is totally linked to the study and knowledge of geometry.There are some materials in nature,whose geometric invariants establish equivalent structural behavior regarding the scalar transformations,developing different spatial typologies according to dimensional variation.Auxetic materials are characterized by their negative Poisson’s ratio.They can change their geometric configuration from a line to a surface,and from a surface to a volume or spatial framework.This paper is based on establishing and comparing those stellated reentrant auxetic geometries to be able to build new spaces defined by their capacity for architectural transformation,studying analytically geometric properties of stellated reentrant auxetic structures that,from the molecular to the macroscopic level,can be part of the architecture construction.In this investigation,a comparative study by means of CAD of stellated reentrant auxetic patterns has been realized.A Computer-Aided Design study of stellated reentrant auxetic structures will be realized to use them in architecture.The geometric behavior of the different stellated reentrant auxetic patterns is analyzed from the developed study to generate a systematic comparison,evaluating properties of these forms,such as their maximum achievable area reductions in relation to the total length of bars of the structure,in order to obtain a growth factor.
基金We acknowledge financial support by the National Natural Science Foundation of China(32071374,32000985,81761148029,81620108028)Program of Shanghai Academic Research Leader under the Science and Technology Innovation Action Plan(21XD1422100)+3 种基金Leading Talent of“Ten Thousand Plan”-National High-Level Talents Special Support Plan,One Belt and One Road International Cooperation Project from Key Research and Development Program of Zhejiang Province(2019C04024)the Zhejiang Provincial Natural Science Foundation of China(LR22C100001,LGF19C100002,LQ21H300003)Zhejiang Province Medical and Health Science Research Project(2021KY666),and Zhejiang Pharmaceutical Association(2019ZYY12)Open access funding provided by Shanghai Jiao Tong University
文摘The structural change-mediated catalytic activity regulation plays a significant role in the biological functions of natural enzymes.However,there is virtually no artificial nanozyme reported that can achieve natural enzyme-like stringent spatiotemporal structure-based catalytic activity regulation.Here,we report a subnanostructural transformable gold@ceria(STGC-PEG)nanozyme that performs tunable catalytic activities via near-infrared(NIR)light-mediated sub-nanostructural transformation.The gold core in STGC-PEG can generate energetic hot electrons upon NIR irradiation,wherein an internal sub-nanostructural transformation is initiated by the conversion between CeO;and electron-rich state of CeO;-x,and active oxygen vacancies generation via the hot-electron injection.Interestingly,the sub-nanostructural transformation of STGC-PEG enhances peroxidase-like activity and unprecedentedly activates plasmon-promoted oxidase-like activity,allowing highly efficient low-power NIR light(50 m W cm;)-activated photocatalytic therapy of tumors.Our atomic-level design and fabrication provide a platform to precisely regulate the catalytic activities of nanozymes via a light-mediated sub-nanostructural transformation,approaching natural enzyme-like activity control in complex living systems.
基金supported by the National Natural Science Foundation of China(Nos.52171164 and 51790484)National Key Laboratory of Science and Technology on Materials under Shock and Impact(WDZC2022-13)+4 种基金the National Key Research and Development Program of China(No.2021YFA0716303)Start-up research grant(No.SRG/2020/000095)of Science and Engineering Research Board,DST,GoI.A∗STAR,Singapore via the Structural Metals and Alloys Program(No.A18B1b0061)the Natural Science Foundation of Liaoning Province(No.2021-MS-009)the China Manned Space Engineering,the Chinese Academy of Sciences(ZDBS-LY-JSC023)the Youth Innovation Promotion Association CAS(No.2021188).
文摘Developing bulk metallic glass composites(BMGCs)with high toughness is vital for their practical application.However,the influence of different microstructures on the impact toughness of BMGCs is still unclear.The effects of Al addition and cryogenic cyclic treatment(CCT)on the Charpy impact toughness,a K,at 298 and 77 K of a series of phase-transformable BMGCs are investigated in this work.It is found that deformation-induced martensitic transformation(DIMT)of theβ-Ti dendrites is the dominant toughening mechanism in the phase-transformable BMGCs at 298 K,but at 77 K,the toughness of BMGCs is primarily determined by the intrinsic toughness of the glass matrix.The addition of Al can moderately tune theβ-Ti phase stability,which then affects the amount of DIMT and impact toughness of the BMGCs at 298 K.However,at 77 K,Al addition causes a monotonic decrease in the toughness of the BMGCs due to the embrittlement of the glass matrix.It is found that CCT can effectively rejuvenate the phase-transformable BMGCs,which results in an enhanced impact toughness at 298 K.However,the toughness at 77 K monotonously decreases with increasing the number of CCT cycles,suggesting that the rejuvenation of the glass matrix affects the toughness at both 298 and 77 K of BMGCs,but in dramatically different ways.These findings reveal the influence of microstructures and CCT on the impact toughness of BMGCs and provide insights that could be useful for designing tougher BMGs and BMGCs.
文摘The solar sail is one of the most promising space exploration systems due to its theoretically infinite specific impulse achieved through solar radiation pressure(SRP).Recently,researchers have proposed“transformable spacecraft”capable of actively reconfiguring their body configurations using actuatable joints.Transformable spacecraft,if used similarly to solar sails,are expected to significantly enhance orbit and attitude control capabilities owing to their high redundancy in control degrees of freedom.However,controlling them becomes challenging due to their large number of inputs,leading previous researchers to impose strong constraints to limit their potential control capabilities.This study focuses on novel attitude control techniques for transformable spacecraft under SRP.We developed two methods,namely,joint angle optimization to obtain arbitrary SRP force and torque,and momentum damping control driven by joint angle actuation.Our proposed methods are formulated in a general manner and can be applied to any transformable spacecraft comprising front faces that can predominantly receive the SRP on each body.The validity of our proposed method is confirmed through numerical simulations.Our study contributes to making most of the high control redundancy of transformable spacecraft without the need for expendable propellants,thus significantly enhancing the orbit and attitude control capabilities.
基金supported by the National Natural Science Foundation of China(52003267 and 51973214)the Natural Science Foundation of Jilin Province(YDZJ202101ZYTS027,China).
文摘Tumor microenvironment activatable therapeutic agents and their effective tumor accumula-tion are significant for selective tumor treatment.Herein,we provide an unadulterated nanomaterial combining the above advantages.We synthesize a perylene diimide(PDI)molecule substituted by glu-tamic acid(Glu),which can self-assemble into small spherical nanoparticles(PDI-SG)in aqueous solu-tion.PDI-SG can not only be transformed into nanofibers at low pH conditions but also be reduced to PDI radical anion(PDI^(·-)),which exhibits strong near-infrared absorption and excellent photothermal perfor-mance.More importantly,PDI-SG can also be reduced to PDI^(·-)in hypoxic tumors to ablate the tumors and minimize the damage to normal tissues.The morphological transformation from small nanoparticles to nanofibers makes for better tumor accumulation and retention.This work sheds light on the design of tumor microenvironment activatable therapeutics with precise structures for high-performance tumor therapy.
基金Chongqing Postdoctoral International Exchange Training Program(7820100997)Fundamental Research Funds for Central Universities(Nos.SWU-XDPY22010)+2 种基金National College Students Innovation and Entrepreneurship Training Program(202310635114)National Natural Science Foundation of China(No.81703424)Chongqing Graduate Student Research Innovation Project(CYB21121).
文摘Developing an oral in situ-forming hydrogel that targets the inflamed intestine to suppress bleeding ulcers and alleviate intestinal inflammation is crucial for effectively treating ulcerative colitis(UC).Here,inspired by sandcastle worm adhesives,we proposed a water-immiscible coacervate(EMNs-gel)with a programmed coacervate-to-hydrogel transition at inflammatory sites composed of dopa-rich silk fibroin matrix containing embedded inflammation-responsive core-shell nanoparticles.Driven by intestinal peristalsis,the EMNs-gel can be actuated forward and immediately transform into a hydrogel once contacting with the inflamed intestine to yield strong tissue adhesion,resulting from matrix metalloproteinases(MMPs)-triggered release of Fe3+from embedded nanoparticles and rearrangement of polymer network of EMNs-gel on inflamed intestine surfaces.Extensive in vitro experiments and in vivo UC models confirmed the preferential hydrogelation behavior of EMNs-gel to inflamed intestine surfaces,achieving highly effective hemostasis,and displaying an extended residence time(48 h).This innovative EMNs-gel provides a non-invasive solution that accurately suppresses severe bleeding and improves intestinal homeostasis in UC,showcasing great potential for clinical applications.
文摘为解决风电机组故障诊断中故障样本不足而导致模型准确率不高的问题,将当下备受关注的数据增强方法-去噪扩散概率模型(denoising diffusion probability model,DDPM)引入到故障诊断领域以生成大量高质量的故障样本数据集。因此,结合Transformer网络,提出了一种DDPM-Transformer风电机组故障样本生成方法。首先,将用于计算机视觉图像生成领域的DDPM模型应用于风电机组故障诊断领域中,通过前向加噪过程将数据逐渐转化为噪声,再通过逆向去噪过程将噪声逐步恢复为原始数据,实现从噪声中生成故障数据,解决数据不平衡问题;其次,通过对原始DDPM中使用的U-net模块进行改进,使用Transformer模型替换U-net网络,利用扩散后的数据和添加的噪声训练Transformer模型,实现噪声预测,以提高故障数据的生成质量;最后,使用多种生成模型评价指标对生成的故障数据进行评价,在监督控制和数据采集系统(supervisory control and data acquisition,SCADA)故障数据生成中论证改进DDPM-Transformer模型的性能。通过试验证明,所提DDPM-Transformer模型与现有的生成模型相比,最大均值异(maximum mean discrepancy,MMD)最大提升0.13,峰值信噪比(peak signal to noise ratio,PSNR)最大提升7.8。所提模型可以有效地生成质量更高的风电机组故障样本,从而基于该样本集辅助训练基于深度学习的故障诊断模型,可以使诊断模型具有更高精度和良好的稳定性。
文摘深度学习是人工智能领域的热门研究方向之一,它通过构建多层人工神经网络模仿人脑对数据的处理机制。大型语言模型(large language model,LLM)基于深度学习的架构,在无需编程指令的情况下,能通过分析大量数据以获得理解和生成人类语言的能力,被广泛应用于自然语言处理、计算机视觉、智慧医疗、智慧交通等诸多领域。文章总结了LLM在医疗领域的应用,涵盖了LLM针对医疗任务的基本训练流程、特殊策略以及在具体医疗场景中的应用。同时,进一步讨论了LLM在应用中面临的挑战,包括决策过程缺乏透明度、输出准确性以及隐私、伦理问题等,随后列举了相应的改进策略。最后,文章展望了LLM在医疗领域的未来发展趋势,及其对人类健康事业发展的潜在影响。
