Ductile and damage-tolerant fibers(DDTFs)are desired in aerospace engineering,mechanical engineering,and biomedical engineering because of their ability to prevent the catastrophic sudden structural/mechanical failure...Ductile and damage-tolerant fibers(DDTFs)are desired in aerospace engineering,mechanical engineering,and biomedical engineering because of their ability to prevent the catastrophic sudden structural/mechanical failure.However,in practice,design and fabrication of DDTFs remain a major challenge due to finite fiber size and limited processing techniques.In this regard,animal silks can provide inspirations.They are hierarchically structured protein fibers with an elegant trade-off of mechanical strength,extensibility and damage tolerance,making them one of the toughest materials known.In this article,we confirmed that nanofibril organization could improve the ductility and damage-tolerance of silk fibers through restricted fibril shearing,controlled slippage and cleavage.Inspired by these strategies,we further established a rational strategy to produce polyamide DDTFs by combining electrospinning and yarn-spinning techniques.The resultant polymeric DDTFs show a silk-like fracture resistance behavior,indicating potential applications in smart textile,biomedicine,and mechanical engineering.展开更多
Yarn-based strain sensors(YSSs)have shown great promising in the fabrication of wearable devices for their good comfortability and fexible designability.However,the false signals generated by the changes in the yarn s...Yarn-based strain sensors(YSSs)have shown great promising in the fabrication of wearable devices for their good comfortability and fexible designability.However,the false signals generated by the changes in the yarn structure of the YSSs are usually ignored.In this study,the generation,the characteristic,and the prediction of these signals were investigated.We recognized that these signals are composed of two negative pseudo peaks and a spurious resistance response plateau.These responses are found to have nothing in common with a true tensile strain,but be attributed to plastic deformation of the fbers.This is due to the fact that the deformation of YSSs exceeds the linear elastic range of the fbers.Although the use of pure elastic fbers can eliminate the spurious resistance response plateau,it will lead to an increase in the pseudo peak to the value compared with a true strain signal peak.Hence,a theoretical model was established to decouple the real signals from the false responses,ensuring the high sensing accuracy of YSSs for applications in wearable devices and artifcial intelligence interfaces.This work provides an in-depth understanding of the response of the YSSs,which might provide inspiration and guidance in the design of high-accuracy fber-based strain sensors.展开更多
The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus ha...The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.展开更多
基金We acknowledge National Natural Science Foundation(No.51973116,U1832109,21935002)Shanghai Pujiang Program(18PJ1408600),the National Natural Science Foundation of China(21808220)the starting grant of ShanghaiTech University and Shanghai Sailing Program(17YF1411500)for support of this work.
文摘Ductile and damage-tolerant fibers(DDTFs)are desired in aerospace engineering,mechanical engineering,and biomedical engineering because of their ability to prevent the catastrophic sudden structural/mechanical failure.However,in practice,design and fabrication of DDTFs remain a major challenge due to finite fiber size and limited processing techniques.In this regard,animal silks can provide inspirations.They are hierarchically structured protein fibers with an elegant trade-off of mechanical strength,extensibility and damage tolerance,making them one of the toughest materials known.In this article,we confirmed that nanofibril organization could improve the ductility and damage-tolerance of silk fibers through restricted fibril shearing,controlled slippage and cleavage.Inspired by these strategies,we further established a rational strategy to produce polyamide DDTFs by combining electrospinning and yarn-spinning techniques.The resultant polymeric DDTFs show a silk-like fracture resistance behavior,indicating potential applications in smart textile,biomedicine,and mechanical engineering.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51973116,U1832109,21935002,52003156)the Users with Excellence Program of Hefei Science Center CAS(2019HSC-UE003)+1 种基金China Postdoctoral Science Foundation(2020M681344)the starting grant of ShanghaiTech University,and State Key Laboratory for Modifcation of Chemical Fibers and Polymer Materials.
文摘Yarn-based strain sensors(YSSs)have shown great promising in the fabrication of wearable devices for their good comfortability and fexible designability.However,the false signals generated by the changes in the yarn structure of the YSSs are usually ignored.In this study,the generation,the characteristic,and the prediction of these signals were investigated.We recognized that these signals are composed of two negative pseudo peaks and a spurious resistance response plateau.These responses are found to have nothing in common with a true tensile strain,but be attributed to plastic deformation of the fbers.This is due to the fact that the deformation of YSSs exceeds the linear elastic range of the fbers.Although the use of pure elastic fbers can eliminate the spurious resistance response plateau,it will lead to an increase in the pseudo peak to the value compared with a true strain signal peak.Hence,a theoretical model was established to decouple the real signals from the false responses,ensuring the high sensing accuracy of YSSs for applications in wearable devices and artifcial intelligence interfaces.This work provides an in-depth understanding of the response of the YSSs,which might provide inspiration and guidance in the design of high-accuracy fber-based strain sensors.
基金This study was supported by grants from the National Natural Science Foundation of China(No.32273105)National Key R&D Program of China(2018YFD0901400),Key S&T Program of Fujian Province(No.2020NZ08003)+2 种基金Special Fund for Ocean and Fisheries of Xiamen(21CZY018HJ01)China Postdoctoral Science Foundation Grant[2019M650153,2021T140393]the Outstanding Postdoctoral Scholarship from the State Key Laboratory of Marine Environmental Science at Xiamen University.Thanks for the support from the Germplasm resources sharing platform of aquatic species in Fujian Province and XMU-MRB Abalone Research Center.
文摘The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.
