Phytochemical study of the n-BuOH extract of Ilex asprella resulted in the discovery of ten new pentacyclic triterpenoid glycosides,comprising nine ursane-type glycosides(1-9)and one oleanane-type glycoside(10),along ...Phytochemical study of the n-BuOH extract of Ilex asprella resulted in the discovery of ten new pentacyclic triterpenoid glycosides,comprising nine ursane-type glycosides(1-9)and one oleanane-type glycoside(10),along with seven known compounds(11-17).Compound 1 is the first reported 19,22-epoxy ursane triterpenoid glycoside,whereas 4 and 5 are rare examples of ursane triterpenoid glycosides containing a 28,19-lactone group.The structural characterization of these compounds was achieved using spectroscopic and chemical techniques,as well as single-crystal X-ray analysis.Compounds 7,12,15,and 17 exhibited moderate cytotoxic activities against H1975 and HCC827 cancer cells.展开更多
As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine...As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.展开更多
Owing to glacial retreat and associated future runoff variations,major concerns have been raised over the sustainability of water resources in the Qilian Mountains.Based on the Python Glacier Evolution Model,we presen...Owing to glacial retreat and associated future runoff variations,major concerns have been raised over the sustainability of water resources in the Qilian Mountains.Based on the Python Glacier Evolution Model,we present projections of the Qiyi glacier for shared socioeconomic pathways(SSPs)calibrated with the glaciological mass balance.The results indicate the air temperature as the dominant factor in the continuous mass loss of the Qiyi Glacier in the future.Glacier area and volume are projected to decline to 0.16±0.11 km2(6.4%±4.4%,relative to 2015)and 0.0023±0.0006 km3(2.1%±1.5%,relative to 2015),respectively,by 2100,for SSP1-2.6.For SSP5-8.5,the glacier will disappear by 2088.The mass loss of the Qiyi Glacier will accelerate before 2050 for all SSPs but will decelerate after 2050 for SSP1-2.6 and SSP2-4.5.The peak water of glacier runoff will occur between2034 and 2045,with the duration of high water from 7 to 18 years.Thereafter,the runoff will rapidly decline till 2070–2080 and remain low afterward.Compared with the existing projections,the present projections indicate that the Qiyi Glacier will experience more drastic shrinkage and ice loss in the coming decades.Finally,the glacier runoff is expected to reach its peak water earlier with a shorter duration of high water.展开更多
In this study, bimetallic nanoscale zero-valent iron particles（nZVI）, including copper/nanoscale zero-valent iron particles（Cu/nZVI） and nickel/nanoscale zero-valent iron particles（Ni/nZVI）, were synthesized by ...In this study, bimetallic nanoscale zero-valent iron particles（nZVI）, including copper/nanoscale zero-valent iron particles（Cu/nZVI） and nickel/nanoscale zero-valent iron particles（Ni/nZVI）, were synthesized by one-step liquid-phase reduction and applied for oxytetracycline（OTC） removal. The effects of contact time and initial p H on the removal efficiency were studied. The as-prepared nanoscale particles were characterized by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）. Finally, the degradation mechanisms of OTC utilizing the as-prepared nanoparticles were investigated by using X-ray photoelectron spectroscopy（XPS） and mass spectrometry（MS）. Cu/n ZVI presented remarkable ability for OTC degradation and removed71.44% of OTC（100 mg/L） in 4 hr, while only 62.34% and 31.05% of OTC was degraded by Ni/nZVI and nZVI respectively. XPS and MS analysis suggested that OTC was broken down to form small molecules by ·OH radicals generated from the corrosion of Fe0. Cu/nZVI and Ni/n ZVI have been proved to have potential as materials for application in OTC removal because of their significant degradation ability toward OTC.展开更多
Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide b...Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers.Recently,black TiO_(2)appears as a strong candidate in the improvement of sunlight harvesting,because of its excellent absorption capacity and utilization of solar radiation.Despite extensive applications in both environmental and energy fields,the use of black TiO_(2)as a photocatalyst in pollutant removal is ambiguous.The primary objective of the review is to comprehensively evaluate the applications of black TiO_(2)in photocatalytic removal of contaminants,including conventional organic contaminants,emerging contaminants,microbes,and heavy metals.The basic properties,photocatalytic mechanism,and synthesis of black TiO_(2)have been summarized and analyzed.Moreover,the stability and recoverability of black TiO_(2)have also been discussed.Finally,the perspectives of the application of black TiO_(2)in pollutant removal have been further discussed.展开更多
Three binuclear rare earth based complexes combining RE ions with semirigid tricarboxylic ligand(H_(3)L).namely,[RE_(2)(L)_(2)(DMF)_(4)][RE=Gd,Tb,and Dy;H_(3)L=5-((4-Carboxybenzyl)oxy)isophthalic acid;DMF=N,N-dimethyl...Three binuclear rare earth based complexes combining RE ions with semirigid tricarboxylic ligand(H_(3)L).namely,[RE_(2)(L)_(2)(DMF)_(4)][RE=Gd,Tb,and Dy;H_(3)L=5-((4-Carboxybenzyl)oxy)isophthalic acid;DMF=N,N-dimethylformamide]complexes,were fabricated success fully.The RE_(2)(L)_(2)(DMF)_(4) co mplexe s consist of two central RE ions with the same coordination environment which were connected by two tridentate bridging carboxylic groups and two syn-syn bidentate bridging carboxylic groups originating from the L^(3-)ligands to form the{RE_(2)}dimeric unit,and thus provides the basis for further constructing a dense three-dimensional(3 D)network structure.Moreover,the present RE_(2)(L)_(2)(DMF)_(4) complexes can be described by a topology diagram with the topology point symbol of{4^(2)·6}_(2){4^(4)·6^(2)·8^(7)·10^(2)}.Weak antiferromagnetic(AFM)coupling between the adjacent RE ions for all the present complexes was found according to the magnetic calculations.The observed significant cryogenic magnetocaloric effect(MCE)with the maximum magnetic entropy change-ΔS_(M)^(max) to be 26.3 J/(kg·K)withΔH=7 T in Gd_(2)(L)_(2)(DMF)_(4) complex makes it competitive for the cryogenic magnetic refrigerant.Moreover,the slow magnetic relaxation behavior at 0.2 T dc field with an obvious large U_(eff)/k=45(4)K and τ_(0)=6.5(2)×10^(-10)s was confirmed in Dy_(2)(L)_(2)(DMF)_(4)complex.This work not only provides an effective strategy for obtaining molecular materials with high MCE,but also confirms that tricarboxylate ligands are the ideal choice for constructing stable high dimensional geometric structures.展开更多
Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates brow...Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue （WAT） and uncoupling protein I （UCP1） expression, leading to an increase in total body energy expenditure by augmented UCPl-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones, including growth plate, trabecular bone, cortical bone, articular cartilage, and bone-tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal （IP） administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-kB ligand （RANKL）- induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice.展开更多
The drug resistance of chemotherapy is a major challenge to overcome for antineoplastic agents and the reverse of drug resistant is essential for cancer therapy. Herein, we developed a drug delivery system which can s...The drug resistance of chemotherapy is a major challenge to overcome for antineoplastic agents and the reverse of drug resistant is essential for cancer therapy. Herein, we developed a drug delivery system which can simultaneously detect/reverse the drug resistance and perform synergetic treatment of cancer. In this work, we integrated cyanine5(Cy5) modified mi RNA(let-7 i)(Cy5-mi RNA) and platinum onto nano-graphene oxide(NGO)(30-50 nm) platform to achieve simultaneously detection/reversion of drug resistance and synergetic treatment of cisplatin resistant SKOV3 cells(SKOV3 DDP cells). The Cy5-mi RNA adsorbed on NGO could selectively bind the drug resistance related m RNA follow by suppress the expression of drug resistance m RNA, and the binding simultaneously induced the release of Cy5-mi RNA from the NGO, thus the fluorescence signal of Cy5 recovered and could be used for drug resistance monitoring.Moreover, the mi RNA suppressed the Cyclin D1 protein expressions thus reversed the drug resistance. The loaded platinum(Ⅳ)(Pt(Ⅳ)) was converted to the therapeutic platinum(Ⅱ)(Pt(Ⅱ)) in both tumor acidic and reductive environment responsive behavior. NGO furtherly performed photothermal therapy under near infrared(NIR) laser irradiation and enhanced the therapeutic effect. All in all, this nanoplatform realized detection/reversion of the drug resistance as well as synergetic chemical-photothermal treatment of ovarian cancer cells, which holds great promise in the treatment of drug resistant cancer cells.展开更多
Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,i...Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,including snow grain size,density,liquid water content,and snow depth was obtained.Black carbon and dust samples were collected from the snow surface.A simultaneous observation using ASD(Analytical Spectral Devices)spectral data was employed in the Qiyi glacier located on Qilian Mountain.The measurements were compared with results obtained from the Snow,Ice,and Aerosol Radiation(SNICAR)model.Additionally,a HYbrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)air mass backward trajectory model was used to track the source of black carbon.The simulation was found to correlate well with observed data.Liquid water content was the most influential factor of albedo among the several influencing fac tors,followed by black carbon content and snow grain size.Finally,snow density change had the least toward albedo.HYSPLIT atmospheric trajectories model can only approximately show the source of black carbon and not clearly indicate the source region of black carbon.展开更多
Damage caused by frost heave leads to costly maintenance in cold regions, like Hokkaido, Japan. Therefore, thestudy of the frost mechanism with experimental and numerical methods has been of great interest. Numerousmo...Damage caused by frost heave leads to costly maintenance in cold regions, like Hokkaido, Japan. Therefore, thestudy of the frost mechanism with experimental and numerical methods has been of great interest. Numerousmodels have been developed to describe the freezing process of saturated soil, which differs from the partiallysaturated conditions in the field. In fact, most subsurface soils are unsaturated. The freezing process of partiallysaturated soils is more complex than saturated soils, as the governing equations show strongly nonlinear characteristics. This study proposes a thermo-hydro-mechanical coupled model considering the heat transfer, waterinfiltration, and deformation of partially saturated soil to reproduce the freezing process of partially saturatedfrost susceptible soils distributed in Hokkaido. This model better considers the water-ice phase change and soilfreezing characteristic curve (SFCC) during freezing under field conditions. The results from the multiphysicssimulations agree well with the frost heave and water migration data from frost heave tests of Touryo soil andFujinomori soil. In addition, this study discussed the influence of the various factors on frost heave amount,including temperature gradients, overburden pressures, water supply conditions, cooling rates, and initial saturation. The simulation results indicate that the frost heave ratio is proportional to the initial degree of saturationand is inversely proportional to the cooling rate and overburden pressure.Moreover, simulation under the open system generates much more frost heave than under the closed system.Finally, the main features of the proposed model are revealed by simulating a closed-system frost heave test. Thesimulation results indicate that the proposed model adequately captures the coupling characteristics of water andice redistribution, temperature development, hydraulic conductivity, and suction in the freezing process. Togetherwith the decreased hydraulic conductivity, the increased suction controls the water flow in the freezing zone. Theinflow water driven by cryogenic suction gradient feeds the ice formation, leads to a rapid increase in total watercontent, expanding the voids that exceed the initial porosity and contributing to the frost heave.展开更多
Syzygium myrsinifolium(Hance)Merr.et Perry is a unique plant resource on Hainan Island,and there are few reports on its chemical constituents.In the present study,we identified the major chemical constituents in the l...Syzygium myrsinifolium(Hance)Merr.et Perry is a unique plant resource on Hainan Island,and there are few reports on its chemical constituents.In the present study,we identified the major chemical constituents in the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry using ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS/MS).The chemical constituents in Syzygium myrsinifolium(Hance)Merr.et Perry were identified rapidly based on the accurate relative molecular mass and combined with literature data and reference substances.A total of 20 compounds,including organic acids,phenolic acids,and flavonoids,were identified.Among these 20 compounds,four organic acids,eight phenolic acids,seven flavonoids,and one coumarin were reported from the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry for the first time.The established method was rapid and accurate,and some chemical constituents in the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry have been identified.This research provided an experimental reference for the study of the constituents and utilization of Syzygium myrsinifolium(Hance)Merr.et Perry.展开更多
Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obt...Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obtained. Black carbon samples were collected from the snow surface. A simultaneous observation using Analytical Spectral Devices was employed in the Qiyi Glacier located in the Qilian Mountain. Analytical Spectral Devices spectrum data were used to analyze spectral re- flectance of snow for different grain size and black carbon content. The measurements were compared with the results obtained from the Snow, Ice, and Aerosol Radiation model, and the simulation was found to correlate well with the ob- served data. However, the simulated albedo was near to 0.98 times of the measured albedo, so the other factors were as- sumed to be constant using the corrected Snow, Ice, and Aerosol Radiation model to estimate the influence of measured snow grain size and black carbon on albedo. Field measurements were controlled to fit the relationship between the snow grain size and black carbon in order to estimate the influence of these factors on the snow albedo.展开更多
In this paper, the significance and history of studying snow grain size is introduced. Based on the assumption that high reflectivity in the visible band and significant decreasing reflectivity of snow surface in the ...In this paper, the significance and history of studying snow grain size is introduced. Based on the assumption that high reflectivity in the visible band and significant decreasing reflectivity of snow surface in the infrared band, the grain size of snow, spherical and non-spherical, is sensitive to changes in remote sensing retrieval foundation. Also, models and algorithms applied in current studies are reviewed, together with their advantages and disadvantages. In addition, in order to obtain retrieval accuracy, some factors that may affect grain size are also discussed, such as temperature, wavelength, arid particle shape, as well as method authentication.展开更多
Purpose–This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of the maglev train at different ...Purpose–This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of the maglev train at different speed levels.Design/methodology/approach–Based on large eddy simulation(LES)method and Kirchhoff–Ffowcs Williams and Hawkings(K-FWH)equations,the characteristics of dipole and quadrupole sound sources of maglev trains at different speed levels were simulated and analyzed by constructing reasonable penetrable integral surface.Findings–The spatial disturbance resulting from the separation of the boundary layer in the streamlined area of the tail car is the source of aerodynamic sound of the maglev train.The dipole sources of the train are mainly distributed around the radio terminals of the head and tail cars of the maglev train,the bottom of the arms of the streamlined parts of the head and tail cars and the nose tip area of the streamlined part of the tail car,and the quadrupole sources are mainly distributed in the wake area.When the train runs at three speed levels of 400,500 and 600 km$h1,respectively,the radiated energy of quadrupole source is 62.4%,63.3%and 71.7%,respectively,which exceeds that of dipole sources.Originality/value–This study can help understand the aerodynamic noise characteristics generated by the high-speed maglev train and provide a reference for the optimization design of its aerodynamic shape.展开更多
The disturbance of the human microbiota influences the occurrence and progression of many diseases.Live therapeutic bacteria,with their genetic manipulability,anaerobic tendencies,and immunomodulatory properties,are e...The disturbance of the human microbiota influences the occurrence and progression of many diseases.Live therapeutic bacteria,with their genetic manipulability,anaerobic tendencies,and immunomodulatory properties,are emerging as promising therapeutic agents.However,their clinical applications face challenges in maintaining activity and achieving precise spatiotemporal release,particularly in the harsh gastrointestinal environment.This review highlights the innovative bacterial functionalized encapsulation strategies developed through advances in physicochemical and biological techniques.We comprehensively review how bacterial encapsulation strategies can be used to provide physical barriers and enhanced adhesion properties to live microorganisms,while introducing superior material properties to live bacteria.In addition,this review outlines how bacterial surface coating can facilitate targeted delivery and precise spatiotemporal release of live bacteria.Furthermore,it elucidates their potential applications for treating different diseases,along with critical perspectives on challenges in clinical translation.This review comprehensively analyzes the connection between functionalized bacterial encapsulation and innovative biomedical applications,providing a theoretical reference for the development of next-generation bacterial therapies.展开更多
Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)...Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.展开更多
Surface wind fields in glacial environments are critical components of local circulation systems and are essential for glacier boundary layer research.Investigating the spatiotemporal characteristics of glacial surfac...Surface wind fields in glacial environments are critical components of local circulation systems and are essential for glacier boundary layer research.Investigating the spatiotemporal characteristics of glacial surface winds and their impacts on local meteorological processes is essential for identifying the mechanisms and spatial heterogeneity of mass balance variations in Tibetan Plateau mountain glaciers under climate change conditions.This study analyzed Qiyi Glacier in the Qilian Mountains,utilizing multiyear meteorological data from automatic weather stations(AWS)and precipitation gauges at various elevations.The key findings revealed that daytime convergence between upper-mid glacier katabatic winds and valley anabatic winds enhanced orographic uplift,increasing precipitation in these zones.Nocturnal wind reversals induce divergent subsidence over upper-mid glacial areas,promoting cloud-free conditions that enhance longwave radiative cooling and glacial cold storage and suppressing ablation.We proposed a conceptual model of glacier wind-precipitation feedback that demonstrates how local circulations(e.g.,katabatic winds)modulate the formation of precipitation maxima in glacial settings.Furthermore,warm-year observations have documented intensified glacier winds.These results suggest that glacial systems may develop self-sustaining protective feedback through local circulation adjustments under climate change.展开更多
Cytokines exert powerful immunomodulatory effects that are critical to physiology and pathology in humans.The application of natural cytokines in clinical studies has not been clearly established,and there are often p...Cytokines exert powerful immunomodulatory effects that are critical to physiology and pathology in humans.The application of natural cytokines in clinical studies has not been clearly established,and there are often problems associated with toxicity or lack of efficacy.The key reasons can be attributed to the pleiotropy of cytokine receptors and undesired activation of off-target cells.With a deeper understanding of the structural principles and functional signals of cytokine-receptor interactions,artificial modification of cytokine signaling through protein engineering and synthetic immunology has become an increasingly feasible and powerful approach.Engineered cytokines are designed to selectively target cells.Herein,the theoretical and experimental evidence of cytokine engineering is reviewed,and the“supercytokines”resulting from structural enhancement and the“immunocytokines”generated by antibody fusion are described.Finally,the“engager cytokines”formed by the crosslinking of cytokines and bispecific immune engagers and other synthetic cytokines formed by nonnatural analogs are also discussed.展开更多
基金supported by the Qi-Huang Chief Scientist Project of the National Administration of Traditional Chinese Medicine(2020).
文摘Phytochemical study of the n-BuOH extract of Ilex asprella resulted in the discovery of ten new pentacyclic triterpenoid glycosides,comprising nine ursane-type glycosides(1-9)and one oleanane-type glycoside(10),along with seven known compounds(11-17).Compound 1 is the first reported 19,22-epoxy ursane triterpenoid glycoside,whereas 4 and 5 are rare examples of ursane triterpenoid glycosides containing a 28,19-lactone group.The structural characterization of these compounds was achieved using spectroscopic and chemical techniques,as well as single-crystal X-ray analysis.Compounds 7,12,15,and 17 exhibited moderate cytotoxic activities against H1975 and HCC827 cancer cells.
基金financial support from the National Natural Science Foundation of China(Grant No.U1637101)The Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(1005-ZAG23011).
文摘As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.
基金supported by the National Natural Science Foundation of China(Nos.42130516,42171139,41871053)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK020102)+1 种基金Natural Science Basic Research Program of Shaanxi Province(No.2023–JC–QN–0300)the Science and Technology Program of Gansu Province(24JRRG012)。
文摘Owing to glacial retreat and associated future runoff variations,major concerns have been raised over the sustainability of water resources in the Qilian Mountains.Based on the Python Glacier Evolution Model,we present projections of the Qiyi glacier for shared socioeconomic pathways(SSPs)calibrated with the glaciological mass balance.The results indicate the air temperature as the dominant factor in the continuous mass loss of the Qiyi Glacier in the future.Glacier area and volume are projected to decline to 0.16±0.11 km2(6.4%±4.4%,relative to 2015)and 0.0023±0.0006 km3(2.1%±1.5%,relative to 2015),respectively,by 2100,for SSP1-2.6.For SSP5-8.5,the glacier will disappear by 2088.The mass loss of the Qiyi Glacier will accelerate before 2050 for all SSPs but will decelerate after 2050 for SSP1-2.6 and SSP2-4.5.The peak water of glacier runoff will occur between2034 and 2045,with the duration of high water from 7 to 18 years.Thereafter,the runoff will rapidly decline till 2070–2080 and remain low afterward.Compared with the existing projections,the present projections indicate that the Qiyi Glacier will experience more drastic shrinkage and ice loss in the coming decades.Finally,the glacier runoff is expected to reach its peak water earlier with a shorter duration of high water.
基金supported by grants from Tai Shan Scholar Foundation(No.ts 201511003)
文摘In this study, bimetallic nanoscale zero-valent iron particles（nZVI）, including copper/nanoscale zero-valent iron particles（Cu/nZVI） and nickel/nanoscale zero-valent iron particles（Ni/nZVI）, were synthesized by one-step liquid-phase reduction and applied for oxytetracycline（OTC） removal. The effects of contact time and initial p H on the removal efficiency were studied. The as-prepared nanoscale particles were characterized by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）. Finally, the degradation mechanisms of OTC utilizing the as-prepared nanoparticles were investigated by using X-ray photoelectron spectroscopy（XPS） and mass spectrometry（MS）. Cu/n ZVI presented remarkable ability for OTC degradation and removed71.44% of OTC（100 mg/L） in 4 hr, while only 62.34% and 31.05% of OTC was degraded by Ni/nZVI and nZVI respectively. XPS and MS analysis suggested that OTC was broken down to form small molecules by ·OH radicals generated from the corrosion of Fe0. Cu/nZVI and Ni/n ZVI have been proved to have potential as materials for application in OTC removal because of their significant degradation ability toward OTC.
基金supported by the National Key Research and Development Plan(Nos.2016YFC0502800)Natural Science Foundation(No.U2040212,51779008)+1 种基金MWR/CAS Institute of Hydroecology(No.1440020035)the Natural Science and Engineering Research Council of Canada。
文摘Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers.Recently,black TiO_(2)appears as a strong candidate in the improvement of sunlight harvesting,because of its excellent absorption capacity and utilization of solar radiation.Despite extensive applications in both environmental and energy fields,the use of black TiO_(2)as a photocatalyst in pollutant removal is ambiguous.The primary objective of the review is to comprehensively evaluate the applications of black TiO_(2)in photocatalytic removal of contaminants,including conventional organic contaminants,emerging contaminants,microbes,and heavy metals.The basic properties,photocatalytic mechanism,and synthesis of black TiO_(2)have been summarized and analyzed.Moreover,the stability and recoverability of black TiO_(2)have also been discussed.Finally,the perspectives of the application of black TiO_(2)in pollutant removal have been further discussed.
基金Project supported by the National Natural Science Foundation of China(91963123)the State Key Laboratory of Solidification Processing in NWPU(SKLSP202020)+1 种基金the Ten Thousand Talents Plan of Zhejiang Province of China(2018R52003)the Fundamental Research Funds for the Provincial University of Zhejiang(GK199900299012-022)。
文摘Three binuclear rare earth based complexes combining RE ions with semirigid tricarboxylic ligand(H_(3)L).namely,[RE_(2)(L)_(2)(DMF)_(4)][RE=Gd,Tb,and Dy;H_(3)L=5-((4-Carboxybenzyl)oxy)isophthalic acid;DMF=N,N-dimethylformamide]complexes,were fabricated success fully.The RE_(2)(L)_(2)(DMF)_(4) co mplexe s consist of two central RE ions with the same coordination environment which were connected by two tridentate bridging carboxylic groups and two syn-syn bidentate bridging carboxylic groups originating from the L^(3-)ligands to form the{RE_(2)}dimeric unit,and thus provides the basis for further constructing a dense three-dimensional(3 D)network structure.Moreover,the present RE_(2)(L)_(2)(DMF)_(4) complexes can be described by a topology diagram with the topology point symbol of{4^(2)·6}_(2){4^(4)·6^(2)·8^(7)·10^(2)}.Weak antiferromagnetic(AFM)coupling between the adjacent RE ions for all the present complexes was found according to the magnetic calculations.The observed significant cryogenic magnetocaloric effect(MCE)with the maximum magnetic entropy change-ΔS_(M)^(max) to be 26.3 J/(kg·K)withΔH=7 T in Gd_(2)(L)_(2)(DMF)_(4) complex makes it competitive for the cryogenic magnetic refrigerant.Moreover,the slow magnetic relaxation behavior at 0.2 T dc field with an obvious large U_(eff)/k=45(4)K and τ_(0)=6.5(2)×10^(-10)s was confirmed in Dy_(2)(L)_(2)(DMF)_(4)complex.This work not only provides an effective strategy for obtaining molecular materials with high MCE,but also confirms that tricarboxylate ligands are the ideal choice for constructing stable high dimensional geometric structures.
基金supported by a R01DE21464 through the National Institutes of Healthan Innovation in Oral Care Award through International Association for Dental Research and Glaxo Smith Kline Consumer Healthcare+2 种基金an Award through International Team of Implantology to JCby GZUCM Science Fund for Creative Research Groups(2016KYTD10)GZUCM Torch Program(A1-AFD015142Z08)to JZ
文摘Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue （WAT） and uncoupling protein I （UCP1） expression, leading to an increase in total body energy expenditure by augmented UCPl-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones, including growth plate, trabecular bone, cortical bone, articular cartilage, and bone-tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal （IP） administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-kB ligand （RANKL）- induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice.
基金supported by the Huxiang Young Talent Program of Hunan Province (No.2018RS3005)the InnovationDriven Project of Central South University (No.2020CX048)+6 种基金the Changsha Science and Technology Plan Project (Nos.kq2005001,kq2004086)the National Natural Science Foundation of China (No.81301258)the Natural Science Foundation of Hunan Province (Nos.2019JJ60071,2020JJ4680)the Shenghua Yuying Project of Central South University,the Hunan Provincial Graduate Research and Innovation Project (No.CX20190242)National College Students’ Innovation and Entrepreneurship Training Program (Nos.S2020105330414,S202010533015X,8304180412)the Postgraduate Innovation Project of Central South University (Nos.2020zzts819,2020zzts408,2020zzts409,2021zzts0977,2021zzts0979)the Open-End Fund for the Valuable and Precision Instruments of Central South University。
文摘The drug resistance of chemotherapy is a major challenge to overcome for antineoplastic agents and the reverse of drug resistant is essential for cancer therapy. Herein, we developed a drug delivery system which can simultaneously detect/reverse the drug resistance and perform synergetic treatment of cancer. In this work, we integrated cyanine5(Cy5) modified mi RNA(let-7 i)(Cy5-mi RNA) and platinum onto nano-graphene oxide(NGO)(30-50 nm) platform to achieve simultaneously detection/reversion of drug resistance and synergetic treatment of cisplatin resistant SKOV3 cells(SKOV3 DDP cells). The Cy5-mi RNA adsorbed on NGO could selectively bind the drug resistance related m RNA follow by suppress the expression of drug resistance m RNA, and the binding simultaneously induced the release of Cy5-mi RNA from the NGO, thus the fluorescence signal of Cy5 recovered and could be used for drug resistance monitoring.Moreover, the mi RNA suppressed the Cyclin D1 protein expressions thus reversed the drug resistance. The loaded platinum(Ⅳ)(Pt(Ⅳ)) was converted to the therapeutic platinum(Ⅱ)(Pt(Ⅱ)) in both tumor acidic and reductive environment responsive behavior. NGO furtherly performed photothermal therapy under near infrared(NIR) laser irradiation and enhanced the therapeutic effect. All in all, this nanoplatform realized detection/reversion of the drug resistance as well as synergetic chemical-photothermal treatment of ovarian cancer cells, which holds great promise in the treatment of drug resistant cancer cells.
基金provided by the National Natural Science Foundation of China(Grant Nos.41501069,41571415)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA20060201,XDA19070302)Science&Technology Basic Resource Investigation Program of China(Grant No.2017YFC0404302).
文摘Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,including snow grain size,density,liquid water content,and snow depth was obtained.Black carbon and dust samples were collected from the snow surface.A simultaneous observation using ASD(Analytical Spectral Devices)spectral data was employed in the Qiyi glacier located on Qilian Mountain.The measurements were compared with results obtained from the Snow,Ice,and Aerosol Radiation(SNICAR)model.Additionally,a HYbrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)air mass backward trajectory model was used to track the source of black carbon.The simulation was found to correlate well with observed data.Liquid water content was the most influential factor of albedo among the several influencing fac tors,followed by black carbon content and snow grain size.Finally,snow density change had the least toward albedo.HYSPLIT atmospheric trajectories model can only approximately show the source of black carbon and not clearly indicate the source region of black carbon.
基金This research was supported in part by Grant-in-Aids for Scientific Research(A,16H02360)and(B,17H03307)from the Japan Society for the Promotion of Science(JSPS)KAKENHI.
文摘Damage caused by frost heave leads to costly maintenance in cold regions, like Hokkaido, Japan. Therefore, thestudy of the frost mechanism with experimental and numerical methods has been of great interest. Numerousmodels have been developed to describe the freezing process of saturated soil, which differs from the partiallysaturated conditions in the field. In fact, most subsurface soils are unsaturated. The freezing process of partiallysaturated soils is more complex than saturated soils, as the governing equations show strongly nonlinear characteristics. This study proposes a thermo-hydro-mechanical coupled model considering the heat transfer, waterinfiltration, and deformation of partially saturated soil to reproduce the freezing process of partially saturatedfrost susceptible soils distributed in Hokkaido. This model better considers the water-ice phase change and soilfreezing characteristic curve (SFCC) during freezing under field conditions. The results from the multiphysicssimulations agree well with the frost heave and water migration data from frost heave tests of Touryo soil andFujinomori soil. In addition, this study discussed the influence of the various factors on frost heave amount,including temperature gradients, overburden pressures, water supply conditions, cooling rates, and initial saturation. The simulation results indicate that the frost heave ratio is proportional to the initial degree of saturationand is inversely proportional to the cooling rate and overburden pressure.Moreover, simulation under the open system generates much more frost heave than under the closed system.Finally, the main features of the proposed model are revealed by simulating a closed-system frost heave test. Thesimulation results indicate that the proposed model adequately captures the coupling characteristics of water andice redistribution, temperature development, hydraulic conductivity, and suction in the freezing process. Togetherwith the decreased hydraulic conductivity, the increased suction controls the water flow in the freezing zone. Theinflow water driven by cryogenic suction gradient feeds the ice formation, leads to a rapid increase in total watercontent, expanding the voids that exceed the initial porosity and contributing to the frost heave.
基金Natural Science Foundation of Hainan Province(Grant No.320QN302)the Central Public-interest Scientific Institution Basal Research Fund for the Chinese Academy of Tropical Agricultural Sciences(Grant No.1251632022005)+1 种基金the Key Laboratory of Tropical Fruits and Vegetables Quality and Safety for State Market Regulation(Grant No.ZX-2022002)Open Fund of Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables(Grant No.KFKT2021002)。
文摘Syzygium myrsinifolium(Hance)Merr.et Perry is a unique plant resource on Hainan Island,and there are few reports on its chemical constituents.In the present study,we identified the major chemical constituents in the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry using ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS/MS).The chemical constituents in Syzygium myrsinifolium(Hance)Merr.et Perry were identified rapidly based on the accurate relative molecular mass and combined with literature data and reference substances.A total of 20 compounds,including organic acids,phenolic acids,and flavonoids,were identified.Among these 20 compounds,four organic acids,eight phenolic acids,seven flavonoids,and one coumarin were reported from the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry for the first time.The established method was rapid and accurate,and some chemical constituents in the leaves of Syzygium myrsinifolium(Hance)Merr.et Perry have been identified.This research provided an experimental reference for the study of the constituents and utilization of Syzygium myrsinifolium(Hance)Merr.et Perry.
基金supported by "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant No. XDB03030204)SKLCS (No. SKLCS-OP-2014-03)Major Research of National Natural Science Foundation of China (Grant No. 41190084)
文摘Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obtained. Black carbon samples were collected from the snow surface. A simultaneous observation using Analytical Spectral Devices was employed in the Qiyi Glacier located in the Qilian Mountain. Analytical Spectral Devices spectrum data were used to analyze spectral re- flectance of snow for different grain size and black carbon content. The measurements were compared with the results obtained from the Snow, Ice, and Aerosol Radiation model, and the simulation was found to correlate well with the ob- served data. However, the simulated albedo was near to 0.98 times of the measured albedo, so the other factors were as- sumed to be constant using the corrected Snow, Ice, and Aerosol Radiation model to estimate the influence of measured snow grain size and black carbon on albedo. Field measurements were controlled to fit the relationship between the snow grain size and black carbon in order to estimate the influence of these factors on the snow albedo.
基金provided by National Science Fundamental Key Project(40930526,40901041)Science Research Program of Global Change Research of China(Grant No.2010CB951404)
文摘In this paper, the significance and history of studying snow grain size is introduced. Based on the assumption that high reflectivity in the visible band and significant decreasing reflectivity of snow surface in the infrared band, the grain size of snow, spherical and non-spherical, is sensitive to changes in remote sensing retrieval foundation. Also, models and algorithms applied in current studies are reviewed, together with their advantages and disadvantages. In addition, in order to obtain retrieval accuracy, some factors that may affect grain size are also discussed, such as temperature, wavelength, arid particle shape, as well as method authentication.
基金The research was supported by the National Key Research and Development Program(Grant No.2020YFA0710903)the Financial Funding Project for Central Colleges and Universities(Grant No.202045014)the Science and Technology Research and Development Program of China State Railway Group Co.,Ltd.(Grant No.P2019J008).
文摘Purpose–This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of the maglev train at different speed levels.Design/methodology/approach–Based on large eddy simulation(LES)method and Kirchhoff–Ffowcs Williams and Hawkings(K-FWH)equations,the characteristics of dipole and quadrupole sound sources of maglev trains at different speed levels were simulated and analyzed by constructing reasonable penetrable integral surface.Findings–The spatial disturbance resulting from the separation of the boundary layer in the streamlined area of the tail car is the source of aerodynamic sound of the maglev train.The dipole sources of the train are mainly distributed around the radio terminals of the head and tail cars of the maglev train,the bottom of the arms of the streamlined parts of the head and tail cars and the nose tip area of the streamlined part of the tail car,and the quadrupole sources are mainly distributed in the wake area.When the train runs at three speed levels of 400,500 and 600 km$h1,respectively,the radiated energy of quadrupole source is 62.4%,63.3%and 71.7%,respectively,which exceeds that of dipole sources.Originality/value–This study can help understand the aerodynamic noise characteristics generated by the high-speed maglev train and provide a reference for the optimization design of its aerodynamic shape.
基金supports of the National Key Research and Development Program of China(2022YFD2100703)the Guangdong Province Key Areas Research and Development Programs(2022B1111070006,China)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2025A1515012225,China)the project of Guangdong Provincial Academy of Sciences(2022GDASZH-2022010101,China)for the financial support.
文摘The disturbance of the human microbiota influences the occurrence and progression of many diseases.Live therapeutic bacteria,with their genetic manipulability,anaerobic tendencies,and immunomodulatory properties,are emerging as promising therapeutic agents.However,their clinical applications face challenges in maintaining activity and achieving precise spatiotemporal release,particularly in the harsh gastrointestinal environment.This review highlights the innovative bacterial functionalized encapsulation strategies developed through advances in physicochemical and biological techniques.We comprehensively review how bacterial encapsulation strategies can be used to provide physical barriers and enhanced adhesion properties to live microorganisms,while introducing superior material properties to live bacteria.In addition,this review outlines how bacterial surface coating can facilitate targeted delivery and precise spatiotemporal release of live bacteria.Furthermore,it elucidates their potential applications for treating different diseases,along with critical perspectives on challenges in clinical translation.This review comprehensively analyzes the connection between functionalized bacterial encapsulation and innovative biomedical applications,providing a theoretical reference for the development of next-generation bacterial therapies.
基金supported by the National Key Research and Development Program of China(No.2018YFE0122200)the National Natural Science Foundation of China(No.52077078)the Fundamental Research Funds for the Central Universities(No.2020MS090).
文摘Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.
基金supported by the National Natural Science Foundation of China(Grant Nos.42130516,41871053,42171139,41371095)。
文摘Surface wind fields in glacial environments are critical components of local circulation systems and are essential for glacier boundary layer research.Investigating the spatiotemporal characteristics of glacial surface winds and their impacts on local meteorological processes is essential for identifying the mechanisms and spatial heterogeneity of mass balance variations in Tibetan Plateau mountain glaciers under climate change conditions.This study analyzed Qiyi Glacier in the Qilian Mountains,utilizing multiyear meteorological data from automatic weather stations(AWS)and precipitation gauges at various elevations.The key findings revealed that daytime convergence between upper-mid glacier katabatic winds and valley anabatic winds enhanced orographic uplift,increasing precipitation in these zones.Nocturnal wind reversals induce divergent subsidence over upper-mid glacial areas,promoting cloud-free conditions that enhance longwave radiative cooling and glacial cold storage and suppressing ablation.We proposed a conceptual model of glacier wind-precipitation feedback that demonstrates how local circulations(e.g.,katabatic winds)modulate the formation of precipitation maxima in glacial settings.Furthermore,warm-year observations have documented intensified glacier winds.These results suggest that glacial systems may develop self-sustaining protective feedback through local circulation adjustments under climate change.
基金supported by the Shenzhen Institute of Synthetic Biology Scientific Research Program(ZTXM20214003)Natural Science Foundation of China(82122055,81872318)Natural Science Foundation of Anhui Province(2108085J13).
文摘Cytokines exert powerful immunomodulatory effects that are critical to physiology and pathology in humans.The application of natural cytokines in clinical studies has not been clearly established,and there are often problems associated with toxicity or lack of efficacy.The key reasons can be attributed to the pleiotropy of cytokine receptors and undesired activation of off-target cells.With a deeper understanding of the structural principles and functional signals of cytokine-receptor interactions,artificial modification of cytokine signaling through protein engineering and synthetic immunology has become an increasingly feasible and powerful approach.Engineered cytokines are designed to selectively target cells.Herein,the theoretical and experimental evidence of cytokine engineering is reviewed,and the“supercytokines”resulting from structural enhancement and the“immunocytokines”generated by antibody fusion are described.Finally,the“engager cytokines”formed by the crosslinking of cytokines and bispecific immune engagers and other synthetic cytokines formed by nonnatural analogs are also discussed.
