Inspired by the robust interfacial adhesion in nature,researchers have hoped to develop hydrogel glues or adhesives with application potentials in medicine and engineering.However,the diverse mechanical(soft,hard,and ...Inspired by the robust interfacial adhesion in nature,researchers have hoped to develop hydrogel glues or adhesives with application potentials in medicine and engineering.However,the diverse mechanical(soft,hard,and stretchable)and compositional properties(micro/macro-porous,or non-porous)of the general solids make it complicated for developing universal hydrogel glues,particularly concerning the issues in adhesion and interfacial compatibility.Here,we propose a hydrogel glue with a novel curing strategy of dual post-crosslinking for the double-network,which means both chemical and physical networks are formed after applying glue to target surfaces.The cured hydrogel exhibits excellent transparency(>94%)and stretchability(areal ratio>1000%).It demonstrates outstanding repair capabilities for both soft and hard substrates,bonding fractured pork bones with a maximum adhesive strength of~1 MPa.The hydrogel glue shows strong adhesion on both porous and non-porous substrates,with maximum adhesion energy exceeding 1800 J·m^(−2).As a multifunctional coating,hydrogel glue features excellent lubricity and stability,making it suitable for large-scale production.The glue provides excellent conformability when applied to elastic substrates,and the coating is ideal for mass production of protective and elastic coatings for medical devices and other targets in fields of engineering and medicine.展开更多
Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and ...Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and atmospheric composition. Vegetation dynamic models has been applied in global change studies, but the com- plex interactions among the carbon （C）, water, and nitrogen （N） cycles have not been adequately addressed in the current models. In this study, a process-based vegetation dynamic model was developed to study the responses of dryland ecosystems to environmental changes, emphasizing on the interactions among the C, water, and N proc- esses. To address the interactions between the C and water processes, it not only considers the effects of annual precipitation on vegetation distribution and soil moisture on organic matter （SOM） decomposition, but also explicitly models root competition for water and the water compensation processes. To address the interactions between C and N processes, it models the soil inorganic mater processes, such as N mineralization/immobilization, denitrifica- tion/nitrification, and N leaching, as well as the root competition for soil N. The model was parameterized for major plant functional types and evaluated against field observations.展开更多
Recent studies on alkaline soils of arid areas suggest a possible contribution of abiotic exchange to soil CO2 flux(Fc).However,both the overall contribution of abiotic CO2 exchange and its drivers remain unknown.He...Recent studies on alkaline soils of arid areas suggest a possible contribution of abiotic exchange to soil CO2 flux(Fc).However,both the overall contribution of abiotic CO2 exchange and its drivers remain unknown.Here we analyzed the environmental variables suggested as possible drivers by previous studies and constructed a function of these variables to model the contribution of abiotic exchange to Fc in alkaline soils of arid areas.An automated flux system was employed to measure Fc in the Manas River Basin of Xinjiang Uygur autonomous region,China.Soil pH,soil temperature at 0–5 cm(Ts),soil volumetric water content at 0–5 cm(θs)and air temperature at10 cm above the soil surface(Tas)were simultaneously analyzed.Results highlight reduced sensitivity of Fc to Ts and good prediction of Fc by the model Fc=R10Q10(Tas–10)/10+r7q7(pH–7)+λTas+μθs+e which represents Fc as a sum of biotic and abiotic components.This presents an approximate method to quantify the contribution of soil abiotic CO2 exchange to Fc in alkaline soils of arid areas.展开更多
The stability and uniformity of solid electrolyte interphase(SEI)are critical for clarifying the origin of capacity fade and safety issues for lithium metal anodes(LMA).However,understanding the interplay of SEI heter...The stability and uniformity of solid electrolyte interphase(SEI)are critical for clarifying the origin of capacity fade and safety issues for lithium metal anodes(LMA).However,understanding the interplay of SEI heterogeneity and Li electrodeposition is limited by the coupling of complex electrochemistry and mechanics processes.Herein,the correlation between the SEI failure behavior and Li deposition morphology is investigated through a quantitative electrochemical-mechanical model.The local deformation and stress of SEI during Li electrodeposition identify that the heterogeneous interface between different components first fails.Compared with the well-known mechanical strength,component uniformity plays the most important role in the initial SEI failure and uneven Li deposition,and a relative component uniformity(p>0.01)represents a proper balance to ensure the stability of the naturally heterogeneous SEI.Furthermore,the component regulation of SEI via the designed electrolyte experimentally demonstrates that improving component uniformity benefits SEI stability and the uniform Li electrodeposition for LMA,thereby increasing the capacity by~20%after 300 cycles.These fundamental understandings and proposed strategy can be not only used to guide the SEI optimization via the electrolyte regulation,but also extended to the rational designs of artificial SEI for high-performance LMA.展开更多
We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was fi...We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was first detected with Wide-field X-ray Telescope(WXT)on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for 12 s.The flare reached a peak flux of 3:9×10^(−9) erg cm^(−2) s^(−1) in 0.5-4 keV,∼300 times brighter than the underlying X-ray emission detected throughout the observation.Rapid and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new transient.Its X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying within 1.8-2.5.The X-ray light curve shows a plateau lasting for∼4 d,followed by a steep decay till becoming undetectable∼10 d after the initial detection.Based on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term transients.No counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these bands.We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical transients.The nature of EP240408a thus remains an enigma.We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of∼10 d.The detection and follow-ups of more of such objects are essential for revealing their origin.展开更多
Tonotopy,the spatial organization of neurons based on their sound frequency responses,is a fundamental feature of the auditory pathway,extending from the cochlea to the auditory cortex.While excitatory neurons have be...Tonotopy,the spatial organization of neurons based on their sound frequency responses,is a fundamental feature of the auditory pathway,extending from the cochlea to the auditory cortex.While excitatory neurons have been considered necessary for tonotopy in the cortex,the role of inhibitory interneurons remains unclear.Using a novel two-channel widefield Ca~(2+)imaging system,the 2-Channel Alternating exposure wide-Field Explorer(2-CAFE),we simultaneously measured the sound responsiveness of distinct neuron types in awake mice.Combined with two-photon imaging,we observed that GABAergic interneurons followed a similar tonotopic organization to the conventional auditory maps at both mesoscale and single-cell resolutions.Among the major interneuron subtypes—parvalbumin(PV),somatostatin(SST),and vasoactive intestinal peptide(VIP)—PV interneurons demonstrated a critical role in maintaining tonotopy.Inactivation of PV neurons,but not VIP or SST neurons,significantly weakened the tonotopic strength in the auditory cortex.These findings establish PV interneurons as essential components of auditory cortical tonotopy.展开更多
Background Corneal stiffness abnormalities play an important role in the onset and progression of keratoconus.However,the limited availability of specialty devices for measuring corneal stiffness restricts their appli...Background Corneal stiffness abnormalities play an important role in the onset and progression of keratoconus.However,the limited availability of specialty devices for measuring corneal stiffness restricts their application in clinical practice.This study aimed to develop a machine learning(ML)model that can predict corneal stiffness based on ocular structures and investigate its efficacy in diagnosing keratoconus.Methods This retrospective study enrolled healthy individuals and keratoconus patients at the Zhongshan Ophthalmic Center from June 2018 to June 2021.Eleven features,including ocular structural parameters,intraocular pressure(IOP),and age were used to train ML regression models for predicting the stiffness parameter at first applanation(SP-A1)and the Corvis biomechanical index for Chinese populations(cCBI)measured by a Corvis ST device.Mean absolute errors(MAEs)and the area under the receiver operating characteristic curve(AUC)were used to evaluate the performance of the models.The diagnostic efficacy of the predicted SP-A1 and cCBI for keratoconus was evaluated by the AUC,net reclassification index(NRI),and integrated discrimination improvement(IDI).Results A total of 1,523 eyes were involved,of which 601 were diagnosed with keratoconus.The MAEs of the SP-A1 prediction were similar in cross-validation(8.95 mmHg/mm)and testing(10.65 mmHg/mm).The R2 value for the SP-A1 prediction exceeded 0.7,indicating that the performance was clinically acceptable.The AUC for the cCBI prediction was 0.935(95%CI 0.906-0.963).The top three predictors for SP-A1 and cCBI were IOP,keratometry,and central corneal thickness.The addition of the predicted SP-A1 and cCBI significantly improved model performance in diagnosing keratoconus,with NRI of 0.607(95%CI 0.367-0.812)and 0.188(95%CI−0.022-0.398),and IDI of 0.028(95%CI 0.006-0.048)and 0.045(95%CI 0.018-0.072),respectively.Conclusion Our models predicted SP-A1 and cCBI relatively accurately in keratoconus and normal corneas.Moreover,the predicted SP-A1 and cCBI values significantly contributed to the diagnosis of keratoconus.These models could provide a potential alternative for evaluating corneal stiffness and thus facilitate keratoconus screening.展开更多
The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new ser...The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new series of positively charged hollow microspheres carrying porphyrin moieties.Such hollow spheres are formed through crosslinking of well-ordered porous thin laminates,initiated by co-assembly of regular monomers and those decorated with porphyrin moieties.On the surface of an individual sphere,densely distributed positive sites attract anionic reactants.The superficial porphyrin decomposes the accumulated reactants under 1 Sun.After degradation and release of products,the photoactive sites are thereby renewed.We demonstrate that polymer network(1:10)exhibited superior sustainable photocatalytic performance with complete degradation of methyl orange(MO)in 40 min with no observable performance deterioration after six cycles.The established close loop of adsorption-reaction-release cycle makes possible many efficient and continuous photo-catalytic processes.展开更多
基金support from the National Natural Science Foundation of China(Nos.22172045,U23A20122,22402049,and 22472047)Key Science Foundation Project of Henan Province(No.232300421146)Natural Science Foundation of Henan Province(No.242300421606).
文摘Inspired by the robust interfacial adhesion in nature,researchers have hoped to develop hydrogel glues or adhesives with application potentials in medicine and engineering.However,the diverse mechanical(soft,hard,and stretchable)and compositional properties(micro/macro-porous,or non-porous)of the general solids make it complicated for developing universal hydrogel glues,particularly concerning the issues in adhesion and interfacial compatibility.Here,we propose a hydrogel glue with a novel curing strategy of dual post-crosslinking for the double-network,which means both chemical and physical networks are formed after applying glue to target surfaces.The cured hydrogel exhibits excellent transparency(>94%)and stretchability(areal ratio>1000%).It demonstrates outstanding repair capabilities for both soft and hard substrates,bonding fractured pork bones with a maximum adhesive strength of~1 MPa.The hydrogel glue shows strong adhesion on both porous and non-porous substrates,with maximum adhesion energy exceeding 1800 J·m^(−2).As a multifunctional coating,hydrogel glue features excellent lubricity and stability,making it suitable for large-scale production.The glue provides excellent conformability when applied to elastic substrates,and the coating is ideal for mass production of protective and elastic coatings for medical devices and other targets in fields of engineering and medicine.
基金supported by the International Science & Technology Cooperation Program of China (2010DFA92720-10)the "Hundred Talents Program" of the Chinese Academy of Sciences (Y174131001)supported by the National Basic Research Program of China (2009CB825105)
文摘Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and atmospheric composition. Vegetation dynamic models has been applied in global change studies, but the com- plex interactions among the carbon （C）, water, and nitrogen （N） cycles have not been adequately addressed in the current models. In this study, a process-based vegetation dynamic model was developed to study the responses of dryland ecosystems to environmental changes, emphasizing on the interactions among the C, water, and N proc- esses. To address the interactions between the C and water processes, it not only considers the effects of annual precipitation on vegetation distribution and soil moisture on organic matter （SOM） decomposition, but also explicitly models root competition for water and the water compensation processes. To address the interactions between C and N processes, it models the soil inorganic mater processes, such as N mineralization/immobilization, denitrifica- tion/nitrification, and N leaching, as well as the root competition for soil N. The model was parameterized for major plant functional types and evaluated against field observations.
基金supported by the National Basic Research Program of China(2009CB825105)
文摘Recent studies on alkaline soils of arid areas suggest a possible contribution of abiotic exchange to soil CO2 flux(Fc).However,both the overall contribution of abiotic CO2 exchange and its drivers remain unknown.Here we analyzed the environmental variables suggested as possible drivers by previous studies and constructed a function of these variables to model the contribution of abiotic exchange to Fc in alkaline soils of arid areas.An automated flux system was employed to measure Fc in the Manas River Basin of Xinjiang Uygur autonomous region,China.Soil pH,soil temperature at 0–5 cm(Ts),soil volumetric water content at 0–5 cm(θs)and air temperature at10 cm above the soil surface(Tas)were simultaneously analyzed.Results highlight reduced sensitivity of Fc to Ts and good prediction of Fc by the model Fc=R10Q10(Tas–10)/10+r7q7(pH–7)+λTas+μθs+e which represents Fc as a sum of biotic and abiotic components.This presents an approximate method to quantify the contribution of soil abiotic CO2 exchange to Fc in alkaline soils of arid areas.
基金supported by the National Natural Science Foundation of China(52175317,U22B2069)the Fundamental Research Funds for the Central Universities(YCJJ202202004)+3 种基金the National Natural Science Foundation of China(52105325)the NSFC Projects of International Cooperation and Exchanges(52020105012)the Guangzhou Science and Technology Program(202201010405)the Key-Area Research and Development Program of Huizhou City(2022BQ010001)。
文摘The stability and uniformity of solid electrolyte interphase(SEI)are critical for clarifying the origin of capacity fade and safety issues for lithium metal anodes(LMA).However,understanding the interplay of SEI heterogeneity and Li electrodeposition is limited by the coupling of complex electrochemistry and mechanics processes.Herein,the correlation between the SEI failure behavior and Li deposition morphology is investigated through a quantitative electrochemical-mechanical model.The local deformation and stress of SEI during Li electrodeposition identify that the heterogeneous interface between different components first fails.Compared with the well-known mechanical strength,component uniformity plays the most important role in the initial SEI failure and uneven Li deposition,and a relative component uniformity(p>0.01)represents a proper balance to ensure the stability of the naturally heterogeneous SEI.Furthermore,the component regulation of SEI via the designed electrolyte experimentally demonstrates that improving component uniformity benefits SEI stability and the uniform Li electrodeposition for LMA,thereby increasing the capacity by~20%after 300 cycles.These fundamental understandings and proposed strategy can be not only used to guide the SEI optimization via the electrolyte regulation,but also extended to the rational designs of artificial SEI for high-performance LMA.
基金based on data obtained with Einstein Probe,a space mission supported by Strategic Priority Program on Space Science of Chinese Academy of Sciences,in collaboration with ESA,MPE and CNES(Grant No.XDA15310000)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0550200)+5 种基金the National Key R&D Program of China(Grant No.2022YFF0711500)the support by the National Natural Science Foundation of China(Grant Nos.12333004,12321003,12103065,12373040,12021003,12025303,12393814,and 12203071)the China Manned Space Project(Grant Nos.CMS-CSST-2021-A13,and CMS-CSST-2021-B11)the Youth Innovation Promotion Association of the Chinese Academy of Sciencessupported by a Ramón y Cajal fellowship(Grant No.RYC2021-030888-I)financial support from AGAUR,CSIC,MCIN and AEI 10.13039/501100011033(Grant Nos.PID2023-151307NB-I00,PIE 20215AT016,CEX2020-001058-M,and 2021-SGR-01270)。
文摘We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was first detected with Wide-field X-ray Telescope(WXT)on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for 12 s.The flare reached a peak flux of 3:9×10^(−9) erg cm^(−2) s^(−1) in 0.5-4 keV,∼300 times brighter than the underlying X-ray emission detected throughout the observation.Rapid and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new transient.Its X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying within 1.8-2.5.The X-ray light curve shows a plateau lasting for∼4 d,followed by a steep decay till becoming undetectable∼10 d after the initial detection.Based on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term transients.No counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these bands.We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical transients.The nature of EP240408a thus remains an enigma.We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of∼10 d.The detection and follow-ups of more of such objects are essential for revealing their origin.
基金supported by the National Natural Science Foundation of China(32430044,32127801,and 32300833)the National Key R&D Program of China(2021YFA0805000)the Fund by China Postdoctoral Science Foundation(2022M720571)。
文摘Tonotopy,the spatial organization of neurons based on their sound frequency responses,is a fundamental feature of the auditory pathway,extending from the cochlea to the auditory cortex.While excitatory neurons have been considered necessary for tonotopy in the cortex,the role of inhibitory interneurons remains unclear.Using a novel two-channel widefield Ca~(2+)imaging system,the 2-Channel Alternating exposure wide-Field Explorer(2-CAFE),we simultaneously measured the sound responsiveness of distinct neuron types in awake mice.Combined with two-photon imaging,we observed that GABAergic interneurons followed a similar tonotopic organization to the conventional auditory maps at both mesoscale and single-cell resolutions.Among the major interneuron subtypes—parvalbumin(PV),somatostatin(SST),and vasoactive intestinal peptide(VIP)—PV interneurons demonstrated a critical role in maintaining tonotopy.Inactivation of PV neurons,but not VIP or SST neurons,significantly weakened the tonotopic strength in the auditory cortex.These findings establish PV interneurons as essential components of auditory cortical tonotopy.
基金supported by the Science and Technology Planning Projects of Guangdong Province(Grant No.2018B010109008)the Guangzhou Key Laboratory Project(Grant No.202002010006)the Key-Area Research and Development of Guangdong Province(Grant No.2020B1111190001).
文摘Background Corneal stiffness abnormalities play an important role in the onset and progression of keratoconus.However,the limited availability of specialty devices for measuring corneal stiffness restricts their application in clinical practice.This study aimed to develop a machine learning(ML)model that can predict corneal stiffness based on ocular structures and investigate its efficacy in diagnosing keratoconus.Methods This retrospective study enrolled healthy individuals and keratoconus patients at the Zhongshan Ophthalmic Center from June 2018 to June 2021.Eleven features,including ocular structural parameters,intraocular pressure(IOP),and age were used to train ML regression models for predicting the stiffness parameter at first applanation(SP-A1)and the Corvis biomechanical index for Chinese populations(cCBI)measured by a Corvis ST device.Mean absolute errors(MAEs)and the area under the receiver operating characteristic curve(AUC)were used to evaluate the performance of the models.The diagnostic efficacy of the predicted SP-A1 and cCBI for keratoconus was evaluated by the AUC,net reclassification index(NRI),and integrated discrimination improvement(IDI).Results A total of 1,523 eyes were involved,of which 601 were diagnosed with keratoconus.The MAEs of the SP-A1 prediction were similar in cross-validation(8.95 mmHg/mm)and testing(10.65 mmHg/mm).The R2 value for the SP-A1 prediction exceeded 0.7,indicating that the performance was clinically acceptable.The AUC for the cCBI prediction was 0.935(95%CI 0.906-0.963).The top three predictors for SP-A1 and cCBI were IOP,keratometry,and central corneal thickness.The addition of the predicted SP-A1 and cCBI significantly improved model performance in diagnosing keratoconus,with NRI of 0.607(95%CI 0.367-0.812)and 0.188(95%CI−0.022-0.398),and IDI of 0.028(95%CI 0.006-0.048)and 0.045(95%CI 0.018-0.072),respectively.Conclusion Our models predicted SP-A1 and cCBI relatively accurately in keratoconus and normal corneas.Moreover,the predicted SP-A1 and cCBI values significantly contributed to the diagnosis of keratoconus.These models could provide a potential alternative for evaluating corneal stiffness and thus facilitate keratoconus screening.
基金supported by the National Natural Science Foundation of China(Nos.22172045,U23A20122,21905076,21905077)the Key Science Foundation Project of Henan Province(No.232300421146)the Key Scientific Research Project of Colleges and Universities in Henan Province(No.22B150001).
文摘The continuous and sustainable photo-activity on micro-or nano-carriers has always been a key stepping stone in the industrialization of photo-catalysis,photo-synthesis,and photo-degradation.Herein,we report a new series of positively charged hollow microspheres carrying porphyrin moieties.Such hollow spheres are formed through crosslinking of well-ordered porous thin laminates,initiated by co-assembly of regular monomers and those decorated with porphyrin moieties.On the surface of an individual sphere,densely distributed positive sites attract anionic reactants.The superficial porphyrin decomposes the accumulated reactants under 1 Sun.After degradation and release of products,the photoactive sites are thereby renewed.We demonstrate that polymer network(1:10)exhibited superior sustainable photocatalytic performance with complete degradation of methyl orange(MO)in 40 min with no observable performance deterioration after six cycles.The established close loop of adsorption-reaction-release cycle makes possible many efficient and continuous photo-catalytic processes.
