The gravitational wave spacecraft is a complex multi-input multi-output dynamic system.The gravitational wave detection mission requires the spacecraft to achieve single spacecraft with two laser links and high-precis...The gravitational wave spacecraft is a complex multi-input multi-output dynamic system.The gravitational wave detection mission requires the spacecraft to achieve single spacecraft with two laser links and high-precision control.Establishing one spacecraftwith two laser links,compared to one spacecraft with a single laser link,requires an upgraded decoupling algorithmfor the link establishment.The decoupling algorithmwe designed reassigns the degrees of freedomand forces in the control loop to ensure sufficient degrees of freedomfor optical axis control.In addressing the distinct dynamic characteristics of different degrees of freedom,a transfer function compensation method is used in the decoupling process to further minimize motion coupling.The open-loop frequency response of the systemis obtained through simulation.The upgraded decoupling algorithms effectively reduce the open-loop frequency response by 30 dB.The transfer function compensation method efficiently suppresses the coupling of low-frequency noise.展开更多
Advanced glycation end products(AGEs)are a complex and heterogencous group of compounds that have been implicated in diabetes related complfcations.Sk in autofluorescence was recently introduced as an altemative tool ...Advanced glycation end products(AGEs)are a complex and heterogencous group of compounds that have been implicated in diabetes related complfcations.Sk in autofluorescence was recently introduced as an altemative tool for skin AGEs accumulation assessment in diabetes.Sucossful optical diagnosis of diabetes requires a rapid and accurate classification algorithm.In order to improve the performance of noninvasive and optical diagnosis of type 2 diabetes,support vector machines(SVM)algorithm was implemented for the clasification of skin autofluorescence from diabetics and control subjects.Cross-validation and grid optimization methods were employed to calculate the optimal parameters that ma ximize classification accuracy.Classification model was set up according to the training set and then veri fied by the testing set.The results show that radical basis fiunction is the best choice in the four common kernels in SVM.Moreover,a diagnostic accuracy of 82.61%,a sensitivity of 69.57%,and a specificity of 95.65%for discriminating diabetics from control subjects were achieved using a mixed kemel function,which is based on liner kernel function and radical basis function.In comparison with fasting plasma glucose and HbAue test,the clasifcation method of skin autofuorescence spectrum based on SVM shows great potential in screening of diabetes.展开更多
Rare earth(RE)ions,with abundant 4f energy level and unique electronic arrangement,are considered as substitutes for Pb^(2+)in perovskite nanocrystals(PNCs),allowing for partial or complete replacement of lead and min...Rare earth(RE)ions,with abundant 4f energy level and unique electronic arrangement,are considered as substitutes for Pb^(2+)in perovskite nanocrystals(PNCs),allowing for partial or complete replacement of lead and minimizing environmental impact.This review provides a comprehensive overview of the characteristics of RE-doped PNCs,including up-conversion luminescence,down-conversion luminescence,and quantum confinement effects,etc.Additionally,RE doping has been found to effectively suppress defect formation,reduce nonradiative recombination,enhance photoluminescence quantum yield(PLQY),and even allow for controlling over the morphology of the nanocrystals.The review also highlights the recent advancements in lead-free RE-based perovskites,especially in the case of Eu-based perovskites(CsEuBr_(3) and CsEuCl_(3)).Furthermore,it briefly introduces the applications of PNCs in various fields,such as perovskite solar cells(PSCs),luminescent solar concentrators(LSCs),photodetectors(PDs),and light-emitting diodes(LEDs).A systematic discussion on the luminescence mechanisms of RE-doped PNCs and lead-free RE-based perovskites is provided,along with an outlook on future research directions.The ultimate goal of this review is to provide guidance for the development of RE-based perovskite optoelectronic devices.展开更多
The photovoltaic properties of double-cable conjugated polymers are significantly influenced by the length of the alkyl linkers that connect donor backbones and acceptor side units. In this study, a series of 2-(3-oxo...The photovoltaic properties of double-cable conjugated polymers are significantly influenced by the length of the alkyl linkers that connect donor backbones and acceptor side units. In this study, a series of 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC)-based double-cable polymers with alkyl linkers ranging from C_8H_(16)to C_(16)H_(32)(Px, x = 8, 10, 12, 14, 16) were synthesized for single-component organic solar cells(SCOSCs). Among these, the linker length x = 12(P12) is found to optimize the power conversion efficiencies(PCEs) in SCOSCs. Specifically, PCEs increase from P8 to P12 and then decline from P12to P16. Detailed investigations of optical absorption, charge transport, and morphology provide insights into the underlying factors contributing to these PCE variations. The findings indicate that the exceptional photovoltaic properties observed in P12 can be attributed to three key factors: A delicate balance between enhanced charge separation facilitated by the increased spacer length and reduced crystallinity resulting from longer spacers, higher charge mobilities, and well-balanced hole/electron transport characteristics. This study highlights the critical role of linker length in determining the photovoltaic properties of double-cable conjugated polymer-based SCOSCs and offers valuable guidance for the design of novel double-cable conjugated polymers.展开更多
Telluride tin(SnTe)is a promising conversion-alloying anode for potassium-ion batteries(PIBs)due to its high theoretical specific capacity induced by multi-electron transport reaction and low operating voltage,whereas...Telluride tin(SnTe)is a promising conversion-alloying anode for potassium-ion batteries(PIBs)due to its high theoretical specific capacity induced by multi-electron transport reaction and low operating voltage,whereas huge volume expansion and poor kinetics behavior become key scientific bottleneck limiting the battery performances.Herein,SnTe nanoparticles physicochemically wrapped by graphene and nitrogen-doped carbon(SnTe@rGO@NC)are proposed as anode materials for PIBs.The pre-electrostatic interaction urges the formation of Sn-C and Te-C chemical bonds between SnTe and double carbon to strengthen the interfacial stability and electron transfer,and the conductive architecture with hierarchical encapsulation effect is beneficial to maintaining the electrode integrity and electrochemical dynamics.It is demon-strated from first principles calculations and experimental results that SnTe@rGO@NC contributes fast electron transmission,strong K-ion adsorption,and superior K-ion diffusion capability.Ex-situ characteri-zations uncover that SnTe undergoes conversion-alloying dual-mechanism with the products of K_(2)Te and K_(4)Sn_(23)replied on Sn redox site(23SnTe+50K^(+)+50e^(-)↔K_(4)Sn_(23)+23K_(2)Te).Thus,the SnTe@rGO@NC electrode delivers a high initial charge specific capacity of 243.9 mAh g^(-1)at 50 mA g^(-1),superior rate performance(112.6 mAh g^(-1)at 1.0 A g^(-1)),and outstanding cyclic stability at various current densities.展开更多
转换-合金基材料被认为是低成本钠离子电池最有价值的负极之一,然而大的体积变化、差的电化学动力学行为成为了阻碍其应用的关键科学问题.在本文中,超薄纳米片自组装Bi_(2)Se_(3)纳米花通过强健的C-O-Bi化学键合作用被锚定在还原氧化石...转换-合金基材料被认为是低成本钠离子电池最有价值的负极之一,然而大的体积变化、差的电化学动力学行为成为了阻碍其应用的关键科学问题.在本文中,超薄纳米片自组装Bi_(2)Se_(3)纳米花通过强健的C-O-Bi化学键合作用被锚定在还原氧化石墨烯(rGO)上,并被氮掺杂碳纳米层(NC)紧密地包裹,构筑出的Bi_(2)Se_(3)@rGO@NC复合材料被用于钠离子电池负极.物理化学限域几何有助于通过容纳大的晶格应变而获得优异的电极完整性,同时通过消除带隙并降低钠离子扩散势垒促进良好的动力学过程.钠离子的插入/脱出是通过以铋离子为氧化还原位点的转换-合金双重反应机制进行的,其中每个分子式单元可实现12个电子的传输(Bi_(2)Se_(3)+12Na^(+)+12e^(−)↔2Na_(3)Bi+3Na_(2)Se).因此Bi_(2)Se_(3)@rGO@NC电极在50 mA g^(-1)电流密度下呈现出高达288.4 mA h g^(-1)的首次充电容量,同时具有超过1000次的超长循环寿命与优异的倍率性能(在5.0 A g^(-1)电流密度下容量为119.9 mA h g^(-1)).本工作为转换-合金负极的系统研究奠定了基础,为钠离子电池电化学反应机理的阐明提供了新的思路.展开更多
Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are...Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are required for protection against ferroptosis.The purpose of the present studywas to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis.Methods:Established human lung fibroblasts MRC-5,WI38,and human LUAD H1650,PC9,H1975,H358,A549,and H1299 cell lines,tumor and matched normal adjacent tissues of LUAD,and plasma from healthy individuals and LUAD patients were used in this study.Immunohistochemistry and immunoblotting were used to analyze protein expression,and quantitative reverse transcription-PCR was used to analyze mRNA expression.Cell viability,cell death,and the lipid reactive oxygen species generationwere measured to evaluate the responses to ferroptosis.Exosomes were observed using transmission electron microscope.The localization of arachidonic acid(AA)was detected using click chemistry labeling followed by confocal microscopy.Interactions between RNAs and proteins were detected using RNA pull-down,RNA immunoprecipitation and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation methods.Proteomic analysis was used to investigate RNA-regulated proteins,and metabolomic analysis was performed to analyze metabolites.Cellderived xenograft,patient-derived xenograft,cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism.Results:Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis.A potential explanation is that exosomal circRNA_101093(cir93)maintained an elevation in intracellular cir93 in LUAD to modulate AA,a poly-unsaturated fatty acid critical for ferroptosisassociated increased peroxidation in the plasma membrane.Mechanistically,cir93 interacted with and increased fatty acid-binding protein 3(FABP3),which transported AA and facilitated its reaction with taurine.Thus,global AA was reduced,whereas N-arachidonoyl taurine(NAT,the product of AA and taurine)was induced.Notably,the role of NAT in suppressing AA incorporation into the plasma membrane was also revealed.In pre-clinical in vivo models,reducing exosome improved ferroptosis-based treatment.Conclusion:Exosome and cir93 are essential for desensitizing LUAD cells to ferroptosis,and blocking exosome may be helpful for future LUAD treatment.展开更多
In this paper,the nonlinear dynamics of a curved pipe is investigated in the case of principal parametric resonance due to pulsating flow and impact with loose supports.The coupled in-plane and out-of-plane governing ...In this paper,the nonlinear dynamics of a curved pipe is investigated in the case of principal parametric resonance due to pulsating flow and impact with loose supports.The coupled in-plane and out-of-plane governing equations with the consideration of von Karman geometric nonUnearity are presented and discretized via the differential quadrature method(DQM).The nonlinear dynamic responses are calculated numerically to demonstrate the influence of pulsating frequency.Finally,the impact is taken into consideration.The influence of clearance on frettingwear damage,such as normal work rate,contact ratio and impact force level,is demonstrated.展开更多
A hertz-linewidth ultra-stable laser(USL), which will be used to detect the clock transition line, in a strontium optical clock will be launched into the China Space Station(CSS) in late 2022. As the core of the USL, ...A hertz-linewidth ultra-stable laser(USL), which will be used to detect the clock transition line, in a strontium optical clock will be launched into the China Space Station(CSS) in late 2022. As the core of the USL, an interference-filter-based externalcavity diode laser(IF-ECDL) was developed. The IF-ECDL has a compact, stable, and environmentally insensitive design.Performances of the IF-ECDL are presented. The developed IF-ECDL can pass the aerospace environmental tests, indicating that the IF-ECDL can be suitable for space missions in the CSS.展开更多
The stability and dynamical behavior of flexible and articulated rigid pipes conveying fluid have attracted the attention of many researchers in the field of fluid-structure interactions.The system of an articulated p...The stability and dynamical behavior of flexible and articulated rigid pipes conveying fluid have attracted the attention of many researchers in the field of fluid-structure interactions.The system of an articulated pipe composed of a flexible pipe and a rigid pipe is a class of hybrid flexible-rigid dynamical problems involving flow-induced vibrations.This paper establishes the governing equations of motion of a hybrid flexible-rigid pipe system based on Hamilton's principle,with the rigid pipe being hinged to the lower end of a flexible cantilevered pipe via a rotational spring.The coupling equations of motion are discretized via a Galerkin's approach.The mathematical model is validated by comparing the eigenvalue branches of a degenerated system by choosing extreme values of the parameters of the hybrid pipe with previous results.In the theoretical analysis,the critical flow velocities are calculated as a function of the stiffness of the rotational spring,mass ratio and length ratio of the rigid and flexible pipes.The unstable modes are detected from the eigenvalue branches and compared with those of a flexible cantilevered pipe.Numerical results show that the critical flow velocity is greatly influenced by several structural parameters.It is found that a small stiffness of the rotational spring tends to predict higher-mode instability,whereas a large rotational spring stiffness would generate a second-mode instability in most cases.In several system parameter spaces,the hybrid pipe may experience a transference of unstable modes with the increase of flow velocity.It is also shown that the hybrid pipe system may lose stability first in the fourth mode in some cases.Some of the fresh results obtained for the hybrid pipe system are expected to be helpful in understanding and controlling the dynamical responses of hybrid flexible-rigid fluid-conveying pipes.展开更多
Currently,architecting a ratio nal and efficient nanoplatform combing with multi-therapeutic modalities is highly obligatory for advanced cancer treatment.In order to remedy the self-limiting hypoxic dilemma of photod...Currently,architecting a ratio nal and efficient nanoplatform combing with multi-therapeutic modalities is highly obligatory for advanced cancer treatment.In order to remedy the self-limiting hypoxic dilemma of photodynamic therapy(PDT),herein,a facile photosensitizer(i.e.,chlorin e6,Ce6) and bioreductive prodrug(i.e.,tirapazamine,TPZ)-coloaded hyaluronic acid(HA) nanomicelles(denoted as TPZ@HA-Ce6)was developed for the cascading mode of photo-bioreductive cancer therapy.Taking the typical advantage of Ce6 coupled HA conjugate,TPZ was easily and successfully accommodated into the hydrophobic core of HA-Ce6 nanomicelles,yielding TPZ@HA-Ce6.It showed good dispersibility and stability with the hydrodynamic size of ca.170 nm.It targeted the CD44 overexpressed cancer cells by receptor-mediated endocytosis way and killed them effectively with singlet oxygen and the subsequent TPZ radicals resulting from the oxygen depletion of PDT.The later was further verified by the hypoxia probe in vivo.Using murine mammary carcinoma 4 T1 model,TPZ@HA-Ce6 nanomicelles exhibited cascading and synergistic anticancer effect of PDT and TPZ bioreductive therapy compared with each monotherapy.This work suggests the promising prospect of the hybrid hyaluronic nanomicelles for highly efficient cancer combination treatment.展开更多
基金supported by the National Key Research and Development Program of China(2022YFC2203700).
文摘The gravitational wave spacecraft is a complex multi-input multi-output dynamic system.The gravitational wave detection mission requires the spacecraft to achieve single spacecraft with two laser links and high-precision control.Establishing one spacecraftwith two laser links,compared to one spacecraft with a single laser link,requires an upgraded decoupling algorithmfor the link establishment.The decoupling algorithmwe designed reassigns the degrees of freedomand forces in the control loop to ensure sufficient degrees of freedomfor optical axis control.In addressing the distinct dynamic characteristics of different degrees of freedom,a transfer function compensation method is used in the decoupling process to further minimize motion coupling.The open-loop frequency response of the systemis obtained through simulation.The upgraded decoupling algorithms effectively reduce the open-loop frequency response by 30 dB.The transfer function compensation method efficiently suppresses the coupling of low-frequency noise.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(083RC11124).
文摘Advanced glycation end products(AGEs)are a complex and heterogencous group of compounds that have been implicated in diabetes related complfcations.Sk in autofluorescence was recently introduced as an altemative tool for skin AGEs accumulation assessment in diabetes.Sucossful optical diagnosis of diabetes requires a rapid and accurate classification algorithm.In order to improve the performance of noninvasive and optical diagnosis of type 2 diabetes,support vector machines(SVM)algorithm was implemented for the clasification of skin autofluorescence from diabetics and control subjects.Cross-validation and grid optimization methods were employed to calculate the optimal parameters that ma ximize classification accuracy.Classification model was set up according to the training set and then veri fied by the testing set.The results show that radical basis fiunction is the best choice in the four common kernels in SVM.Moreover,a diagnostic accuracy of 82.61%,a sensitivity of 69.57%,and a specificity of 95.65%for discriminating diabetics from control subjects were achieved using a mixed kemel function,which is based on liner kernel function and radical basis function.In comparison with fasting plasma glucose and HbAue test,the clasifcation method of skin autofuorescence spectrum based on SVM shows great potential in screening of diabetes.
基金supported by the Science and Technology Commission of Shanghai Municipality(21ZR1408800)the National Natural Science Foundation of China(11975081).
文摘Rare earth(RE)ions,with abundant 4f energy level and unique electronic arrangement,are considered as substitutes for Pb^(2+)in perovskite nanocrystals(PNCs),allowing for partial or complete replacement of lead and minimizing environmental impact.This review provides a comprehensive overview of the characteristics of RE-doped PNCs,including up-conversion luminescence,down-conversion luminescence,and quantum confinement effects,etc.Additionally,RE doping has been found to effectively suppress defect formation,reduce nonradiative recombination,enhance photoluminescence quantum yield(PLQY),and even allow for controlling over the morphology of the nanocrystals.The review also highlights the recent advancements in lead-free RE-based perovskites,especially in the case of Eu-based perovskites(CsEuBr_(3) and CsEuCl_(3)).Furthermore,it briefly introduces the applications of PNCs in various fields,such as perovskite solar cells(PSCs),luminescent solar concentrators(LSCs),photodetectors(PDs),and light-emitting diodes(LEDs).A systematic discussion on the luminescence mechanisms of RE-doped PNCs and lead-free RE-based perovskites is provided,along with an outlook on future research directions.The ultimate goal of this review is to provide guidance for the development of RE-based perovskite optoelectronic devices.
基金jointly supported by the Beijing Natural Science Foundation (Nos.2212045 and JQ21006)the National Natural Science Foundation of China (Nos.21905158, 52073016 and 92163128)+2 种基金further supported by the Fundamental Research Funds for the Central Universities (Nos.buctrc202111, buctrc201828, and XK1802-2)the Opening Foundation of State Key Laboratory of Organic-Inorganic Composites of Beijing University of Chemical Technology (No.oic-202201006)Jiangxi Provincial Department of Science and Technology (Nos.20202ACBL213004, 20212BCJ23035, jxsq2019102004)。
文摘The photovoltaic properties of double-cable conjugated polymers are significantly influenced by the length of the alkyl linkers that connect donor backbones and acceptor side units. In this study, a series of 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC)-based double-cable polymers with alkyl linkers ranging from C_8H_(16)to C_(16)H_(32)(Px, x = 8, 10, 12, 14, 16) were synthesized for single-component organic solar cells(SCOSCs). Among these, the linker length x = 12(P12) is found to optimize the power conversion efficiencies(PCEs) in SCOSCs. Specifically, PCEs increase from P8 to P12 and then decline from P12to P16. Detailed investigations of optical absorption, charge transport, and morphology provide insights into the underlying factors contributing to these PCE variations. The findings indicate that the exceptional photovoltaic properties observed in P12 can be attributed to three key factors: A delicate balance between enhanced charge separation facilitated by the increased spacer length and reduced crystallinity resulting from longer spacers, higher charge mobilities, and well-balanced hole/electron transport characteristics. This study highlights the critical role of linker length in determining the photovoltaic properties of double-cable conjugated polymer-based SCOSCs and offers valuable guidance for the design of novel double-cable conjugated polymers.
基金supported by the National Natural Science Foun-dation of China(No.52207248)China Postdoctoral Science Foun-dation(Nos.2022M722606,2021TQ0266)+2 种基金Natural Science Basic Research Program of Shaanxi(No.2022JQ-113)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110164 and 2022A1515010208)the Fundamental Research Funds for the Central Universities(No.G2020KY0534)。
文摘Telluride tin(SnTe)is a promising conversion-alloying anode for potassium-ion batteries(PIBs)due to its high theoretical specific capacity induced by multi-electron transport reaction and low operating voltage,whereas huge volume expansion and poor kinetics behavior become key scientific bottleneck limiting the battery performances.Herein,SnTe nanoparticles physicochemically wrapped by graphene and nitrogen-doped carbon(SnTe@rGO@NC)are proposed as anode materials for PIBs.The pre-electrostatic interaction urges the formation of Sn-C and Te-C chemical bonds between SnTe and double carbon to strengthen the interfacial stability and electron transfer,and the conductive architecture with hierarchical encapsulation effect is beneficial to maintaining the electrode integrity and electrochemical dynamics.It is demon-strated from first principles calculations and experimental results that SnTe@rGO@NC contributes fast electron transmission,strong K-ion adsorption,and superior K-ion diffusion capability.Ex-situ characteri-zations uncover that SnTe undergoes conversion-alloying dual-mechanism with the products of K_(2)Te and K_(4)Sn_(23)replied on Sn redox site(23SnTe+50K^(+)+50e^(-)↔K_(4)Sn_(23)+23K_(2)Te).Thus,the SnTe@rGO@NC electrode delivers a high initial charge specific capacity of 243.9 mAh g^(-1)at 50 mA g^(-1),superior rate performance(112.6 mAh g^(-1)at 1.0 A g^(-1)),and outstanding cyclic stability at various current densities.
基金supported by the Natural Science Basic Research Program of Shaanxi(2022JQ-113)Guangdong Basic and Applied Basic Research Foundation(2021A1515110164 and 2022A1515010208)+1 种基金China Postdoctoral Science Foundation(2021TQ0266 and 2022M722606)the Fundamental Research Funds for the Central Universities(G2020KY0534)。
文摘转换-合金基材料被认为是低成本钠离子电池最有价值的负极之一,然而大的体积变化、差的电化学动力学行为成为了阻碍其应用的关键科学问题.在本文中,超薄纳米片自组装Bi_(2)Se_(3)纳米花通过强健的C-O-Bi化学键合作用被锚定在还原氧化石墨烯(rGO)上,并被氮掺杂碳纳米层(NC)紧密地包裹,构筑出的Bi_(2)Se_(3)@rGO@NC复合材料被用于钠离子电池负极.物理化学限域几何有助于通过容纳大的晶格应变而获得优异的电极完整性,同时通过消除带隙并降低钠离子扩散势垒促进良好的动力学过程.钠离子的插入/脱出是通过以铋离子为氧化还原位点的转换-合金双重反应机制进行的,其中每个分子式单元可实现12个电子的传输(Bi_(2)Se_(3)+12Na^(+)+12e^(−)↔2Na_(3)Bi+3Na_(2)Se).因此Bi_(2)Se_(3)@rGO@NC电极在50 mA g^(-1)电流密度下呈现出高达288.4 mA h g^(-1)的首次充电容量,同时具有超过1000次的超长循环寿命与优异的倍率性能(在5.0 A g^(-1)电流密度下容量为119.9 mA h g^(-1)).本工作为转换-合金负极的系统研究奠定了基础,为钠离子电池电化学反应机理的阐明提供了新的思路.
基金National Natural Science Foundation of China,Grant/Award Numbers:81871907,81822029,81872288,82173015,81902315,81902869,81774291ShanghaiMunicipal Education Commission-Gaofeng Clinical Medicine,Grant/Award Number:20191834+5 种基金Project of Clinical Research Supporting SystemClinical Medicine First-class DisciplineShanghai Municipal Education Commission and Shanghai Education Development Foundation,Grant/Award Number:18CG16Shanghai Sailing Program,Grant/Award Number:19YF1444800Science and technology commission of Shanghai municipality project,Grant/Award Numbers:19140902600,21140902800Shanghai ChestHospital,Grant/Award Numbers:2018YNJCM01,2019YNJCM06,2021YNZYJ01,2021YNZYY01,2021YNZYY02。
文摘Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are required for protection against ferroptosis.The purpose of the present studywas to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis.Methods:Established human lung fibroblasts MRC-5,WI38,and human LUAD H1650,PC9,H1975,H358,A549,and H1299 cell lines,tumor and matched normal adjacent tissues of LUAD,and plasma from healthy individuals and LUAD patients were used in this study.Immunohistochemistry and immunoblotting were used to analyze protein expression,and quantitative reverse transcription-PCR was used to analyze mRNA expression.Cell viability,cell death,and the lipid reactive oxygen species generationwere measured to evaluate the responses to ferroptosis.Exosomes were observed using transmission electron microscope.The localization of arachidonic acid(AA)was detected using click chemistry labeling followed by confocal microscopy.Interactions between RNAs and proteins were detected using RNA pull-down,RNA immunoprecipitation and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation methods.Proteomic analysis was used to investigate RNA-regulated proteins,and metabolomic analysis was performed to analyze metabolites.Cellderived xenograft,patient-derived xenograft,cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism.Results:Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis.A potential explanation is that exosomal circRNA_101093(cir93)maintained an elevation in intracellular cir93 in LUAD to modulate AA,a poly-unsaturated fatty acid critical for ferroptosisassociated increased peroxidation in the plasma membrane.Mechanistically,cir93 interacted with and increased fatty acid-binding protein 3(FABP3),which transported AA and facilitated its reaction with taurine.Thus,global AA was reduced,whereas N-arachidonoyl taurine(NAT,the product of AA and taurine)was induced.Notably,the role of NAT in suppressing AA incorporation into the plasma membrane was also revealed.In pre-clinical in vivo models,reducing exosome improved ferroptosis-based treatment.Conclusion:Exosome and cir93 are essential for desensitizing LUAD cells to ferroptosis,and blocking exosome may be helpful for future LUAD treatment.
文摘In this paper,the nonlinear dynamics of a curved pipe is investigated in the case of principal parametric resonance due to pulsating flow and impact with loose supports.The coupled in-plane and out-of-plane governing equations with the consideration of von Karman geometric nonUnearity are presented and discretized via the differential quadrature method(DQM).The nonlinear dynamic responses are calculated numerically to demonstrate the influence of pulsating frequency.Finally,the impact is taken into consideration.The influence of clearance on frettingwear damage,such as normal work rate,contact ratio and impact force level,is demonstrated.
基金This work was supported by the National Key R&D Program of China(No.2020YFC2201300)the National Natural Science Foundation of China(No.11903041)。
文摘A hertz-linewidth ultra-stable laser(USL), which will be used to detect the clock transition line, in a strontium optical clock will be launched into the China Space Station(CSS) in late 2022. As the core of the USL, an interference-filter-based externalcavity diode laser(IF-ECDL) was developed. The IF-ECDL has a compact, stable, and environmentally insensitive design.Performances of the IF-ECDL are presented. The developed IF-ECDL can pass the aerospace environmental tests, indicating that the IF-ECDL can be suitable for space missions in the CSS.
基金supported by the National Natural Science Foundation of China(Grant Nos.11902112,11972167,and 12072119)Hubei Superior and Distinctive Discipline Group of"Mechatronics and Automobiles"(Grant No.XKQ2021042).
文摘The stability and dynamical behavior of flexible and articulated rigid pipes conveying fluid have attracted the attention of many researchers in the field of fluid-structure interactions.The system of an articulated pipe composed of a flexible pipe and a rigid pipe is a class of hybrid flexible-rigid dynamical problems involving flow-induced vibrations.This paper establishes the governing equations of motion of a hybrid flexible-rigid pipe system based on Hamilton's principle,with the rigid pipe being hinged to the lower end of a flexible cantilevered pipe via a rotational spring.The coupling equations of motion are discretized via a Galerkin's approach.The mathematical model is validated by comparing the eigenvalue branches of a degenerated system by choosing extreme values of the parameters of the hybrid pipe with previous results.In the theoretical analysis,the critical flow velocities are calculated as a function of the stiffness of the rotational spring,mass ratio and length ratio of the rigid and flexible pipes.The unstable modes are detected from the eigenvalue branches and compared with those of a flexible cantilevered pipe.Numerical results show that the critical flow velocity is greatly influenced by several structural parameters.It is found that a small stiffness of the rotational spring tends to predict higher-mode instability,whereas a large rotational spring stiffness would generate a second-mode instability in most cases.In several system parameter spaces,the hybrid pipe may experience a transference of unstable modes with the increase of flow velocity.It is also shown that the hybrid pipe system may lose stability first in the fourth mode in some cases.Some of the fresh results obtained for the hybrid pipe system are expected to be helpful in understanding and controlling the dynamical responses of hybrid flexible-rigid fluid-conveying pipes.
基金supported,in part or in whole,by the National Natural Science Foundation of China (Nos.81471785,81671821,11772088,11802056,31800780,11972111,31900940,U19A2006,32071304)the Basic Research Program of Sichuan Science and Technology (Nos.2021YJ0130,2019YJ0183,2019YJ0184)+1 种基金China Postdoctoral Science Foundation (Nos.2018M640904,2019T120831)the Fundamental Research Funds for the Central Universities (No.ZYGX2019J117)。
文摘Currently,architecting a ratio nal and efficient nanoplatform combing with multi-therapeutic modalities is highly obligatory for advanced cancer treatment.In order to remedy the self-limiting hypoxic dilemma of photodynamic therapy(PDT),herein,a facile photosensitizer(i.e.,chlorin e6,Ce6) and bioreductive prodrug(i.e.,tirapazamine,TPZ)-coloaded hyaluronic acid(HA) nanomicelles(denoted as TPZ@HA-Ce6)was developed for the cascading mode of photo-bioreductive cancer therapy.Taking the typical advantage of Ce6 coupled HA conjugate,TPZ was easily and successfully accommodated into the hydrophobic core of HA-Ce6 nanomicelles,yielding TPZ@HA-Ce6.It showed good dispersibility and stability with the hydrodynamic size of ca.170 nm.It targeted the CD44 overexpressed cancer cells by receptor-mediated endocytosis way and killed them effectively with singlet oxygen and the subsequent TPZ radicals resulting from the oxygen depletion of PDT.The later was further verified by the hypoxia probe in vivo.Using murine mammary carcinoma 4 T1 model,TPZ@HA-Ce6 nanomicelles exhibited cascading and synergistic anticancer effect of PDT and TPZ bioreductive therapy compared with each monotherapy.This work suggests the promising prospect of the hybrid hyaluronic nanomicelles for highly efficient cancer combination treatment.