In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neur...In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neurofunctional recovery.Activin A is a critical growth factor necessary for the development of the embryonic nervous system and for maintaining neuronal function in the adult cerebral cortex.It can inhibit excessive autophagy in ischemic stroke to reduce neuronal damage.However,the specific mechanism through which Activin A functions in the spinal cord remains poorly understood.In this study,we administered different concentrations of Activin A to neural stem cells from the spinal cord and found that Activin A stimulated the proliferation and neuronal differentiation of neural stem cells.Then,we established an in vitro oxidative stress model by using hydrogen peroxide to stimulate the neural stem cells-induced neurons.We found that Activin A could reduce apoptosis caused by oxidative stress.Subsequently,we treated a mouse model of spinal cord contusion with intrathecal injection of Activin A.Behavioral and electrophysiological results showed that Activin A promoted recovery of motor function and reconstruction of neural circuits in the model mice.Finally,RNA sequencing indicated that Activin A inhibited autophagy by activating the PI3K/AKT/mTOR pathway and upregulating the expression of synaptogenesis-related factor Sema3A in the spinal cord.These results suggest that Activin A may mediate the excessive autophagic response after spinal cord injury,promote the reconstruction of damaged neural circuits,and restore neurological function in the injured spinal cord.展开更多
In this paper,we investigate analytical numerical iterative strategies for the pursuit-evasion game involving spacecraft with leader–follower information.In the proposed problem,the interplay between two spacecraft g...In this paper,we investigate analytical numerical iterative strategies for the pursuit-evasion game involving spacecraft with leader–follower information.In the proposed problem,the interplay between two spacecraft gives rise to a dynamic and real-time game,complicated further by the presence of perturbation.The primary challenge lies in crafting control strategies that are both efficient and applicable to real-time game problems within a nonlinear system.To overcome this challenge,we introduce the model prediction and iterative correction technique proposed in model predictive static programming,enabling the generation of strategies in analytical iterative form for nonlinear systems.Subsequently,we proceed by integrating this model predictive framework into a simplified Stackelberg equilibrium formulation,tailored to address the practical complexities of leader–follower pursuit-evasion scenarios.Simulation results validate the effectiveness and exceptional efficiency of the proposed solution within a receding horizon framework.展开更多
The high morbidity and mortality of colorectal cancer(CRC)is a major challenge in clinical practice.Although a series of alternative research models of CRC have been developed,appropriate orthotopic animal models that...The high morbidity and mortality of colorectal cancer(CRC)is a major challenge in clinical practice.Although a series of alternative research models of CRC have been developed,appropriate orthotopic animal models that reproduce the specific clinical response as well as pathophysiological immune features of CRC are still lacking.In the current study,we constructed a CRC orthotopic xenograft model by implanting the tumor tubes at the colorectum of mice and monitored the model development using bioluminescence imaging.This model successfully recapitulates the clinical chemo-therapy efficacy,including reduced total flux,tumor weight,and the expression of Ki67 after treatment of the first-line chemotherapy regime of CRC(FOLFOX:oxaliplatin and 5-fluorouracil/calcium folinate).The model also reproduced the immunosup-pressive effect of FOLFOX,indicated by decreased infiltration of macrophages and increased Treg cells in tumor.Additionally,the orthotopic xenograft approach may be applied in immunodeficient NCG/NSG mice for constructing patient-derived xeno-grafts,and being used in clinical precision medicine and drug evaluation.We believe the current model is a successful surgical orthotopic xenograft approach for cancer research and deserves to be popularized,which will provide a convenient and efficient platform for in-depth mechanism exploration of CRC and preclinical drug evaluation.展开更多
A cluster of serpentinite bodies has been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong'an,western Dabie orogen,central China.Two types of serpentinites are...A cluster of serpentinite bodies has been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong'an,western Dabie orogen,central China.Two types of serpentinites are identified on the basis of integrated petrographic,mineralogical and geochemical study.The first type,represented by Yinshanzhai serpentinite complex(Group 1)comprises heterogeneous lithology as a massive serpentinite matrix“intruded”by antigoriteenriched serpentinite lenses.They are both pseudomorphic textured with different mineral assemblages indicating an increasing temperature-pressure condition.Serpentinite matrix(Group 1a)is chemically characterized by high MgO/SiO_(2)and low Al_(2)O_(3)/SiO_(2),Ti and Ca contents,suggesting a depleted mantle wedge origin.The coexistence of compositionally-heterogeneous chromite with highCr^(#)(0.78-0.96)and intermediate-Cr^(#)(0.59-0.70)pristine cores indicates extensive mantle melting.Meanwhile,extremely high Fo olivine relicts(96-97)with considerably higher MnO and lower NiO contents than mantle olivine indicate that they are metamorphic products from serpentine decomposition.Accordingly,we propose that Yinshanzhai serpentinite complex experienced two distinct episodes of hydration.The serpentinite lenses(Group 1b)show higher SiO_(2)and lower MgO concentrations.Nevertheless,the trace elements of groups 1a and 1b are consistent:U-shaped REE patterns,positive Eu anomalies and enrichment of LILE(i.e.,Cs,U)are all identified as forearc properties.They are affected by reducing slab-derived fluids in forearc mantle,with f_(O2)of 1 to 2 logarithmic units below f_(O2)of fayalite-magnetite-quartz buffer(FMQ-2~FMQ-1).The second type is antigorite-serpentinites(Group2)represented by Ximaoshan and Wangchunwan blocks.They are non-pseudomorphic,with no primary framework silicate surviving.Fertile compositions(i.e.,higher Al_(2)O_(3)and Al_(2)O_(3)/SiO_(2),nearly flat REE patterns)and conjoint enrichment of LILE with HFSE suggest melt/rock interaction.Negative Ce,Eu anomalies,and enriched U relative to alkaline elements demonstrate interactions with more oxidized seawater or seafloor fluids(FMQ~FMQ-1).Remarkable Sr negative anomalies may be attributed to Sr release during lizardite/antigorite transition in subduction zone,indicating interaction with low-Sr slab fluids.We propose that Group 2 serpentinites originate either from mantle wedge or abyssal peridotites,refertilized by mantle melts,then hydrated in seafloor or shallow forearc and entrapped into subduction channel.Combined with geochronology and tectonic constraints of associated eclogites in Hong'an terrane,the two types of serpentinites may correlate with subduction of different oceanic basins during the late Paleozoic and/or Proterozoic eras.It raises possibility of defining an ophiolitic setting in Hong'an Orogen for which further evidence is required.展开更多
The plant cell wall serves as a barrier in defense against pathogen invasion.However,the specific contribution of cell walls in vascular tissues to plant immunity remains largely unexplored.In this study,we demonstrat...The plant cell wall serves as a barrier in defense against pathogen invasion.However,the specific contribution of cell walls in vascular tissues to plant immunity remains largely unexplored.In this study,we demonstrate that OsCSLC3,a member of the rice cellulose synthase-like(CSL)gene family,is predominantly expressed in vascular tissues and that its overexpression promotes hemicellulose biosynthesis.This enhancement of hemicellulose accumulation is associated with improved disease resistance.Targeted editing of conserved cis-regulatory elements in the OsCSLC35′untranslated region(UTR)showed that deletion of the specific fragment(−575 to−824 bp)elevated OsCSLC3 transcript levels,promoted hemicellulose accumulation,enhanced disease resistance,and improved agronomic traits.Our findings highlight a previously underappreciated role for hemicellulose in plant immunity and demonstrate that precise 5′UTR editing is a promising strategy for improving disease resistance and agronomic traits.展开更多
Metal dopant,such as aluminum,has a significant influence on the performance of amorphous Si_(2)BC_(3)N ceramics and is of particular interest.In this work,the structural responses of amorphous Si_(2)BC_(3)N to incorp...Metal dopant,such as aluminum,has a significant influence on the performance of amorphous Si_(2)BC_(3)N ceramics and is of particular interest.In this work,the structural responses of amorphous Si_(2)BC_(3)N to incorporating aluminum and related mechanical property modification are investigated employing ab initio molecular dynamics calculations.Considering different Al sources of Al and AlN,two models,i.e.Si_(2)BC_(3)NAl_(0.6)and Si_(2)BC_(3)N_(1.6)Al_(0.6)are constructed,respectively.It is found that the integration of Al engenders the Al-Si,Al-C,and Al-N chemical bonds within the amorphous framework,while the proportions of C-C and Si-Si bonds decrease,indicating that Al promotes a transition from nested polyhedra to independent polyhedral structures.The incorporation of Al induces an increase in tetrahedral arrangements and a decrease in sp^(2)-like trigonal configurations compared to amorphous Si_(2)BC_(3)N.This structural transformation contributes to the enhancement of mechanical characteristics of Si_(2)BC_(3)NAl_(0.6)ceramics.Conversely,Si_(2)BC_(3)N_(1.6)Al_(0.6)shows a marginal increase in tetrahedral configurations,resulting in similar mechanical performance to Si_(2)BC_(3)N.This work elucidates a novel mechanism of local structure transformation in amorphous SiBCN ceramics with incorporated metal elements.展开更多
Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, larg...Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, large thermal expansion coefficient, excellent damage tolerance and moderate mechanical properties are the main requirements of promising TBC materials. In order to improve the efficiency of jet and/or gas turbine engines, which is the key of improved thrust-to-weight ratios and the energysaving, significant efforts have been made on searching for enhanced TBC materials. Theoretically, density functional theory has been successfully used in scanning the structure and properties of materials, and at the same time predicting the mechanical and thermal properties of promising TBC materials for high and ultrahigh temperature applications, which are validated by subsequent experiments. Experimentally,doping and/or alloying are also widely applied to further decrease their thermal conductivities. Now, the strategy through combining theoretical calculations and experiments on searching for next generation thermal insulator materials is widely adopted. In this review, the common used techniques and the recent advantages on searching for promising TBC materials in both theory and experiments are summarized.展开更多
Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE)...Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE) can present a methodology to deal with this difficulty, although DOE is not commonly spread in corrosion field. Thus, modeling corrosion of Ni-Cr-Mo-V steel in deep sea environment was performed in order to provide example demonstrating the advantage of DOE. In addition, an artificial neural network mapping using back-propagation method was developed for Ni-Cr-Mo-V steel such that the ANN model can be used to predict polarization curves under different complex sea environments without experimentation. Furthermore, roles of environment factors on corrosion of Ni-Cr-Mo-V steel in deep sea environment were discussed.展开更多
Recent technical progress in the industry has led to an urgent requirement on new materials with enhanced multi-properties.To meet this multi-property requirement,the materials consisting of three and more elements ha...Recent technical progress in the industry has led to an urgent requirement on new materials with enhanced multi-properties.To meet this multi-property requirement,the materials consisting of three and more elements have attracted increasing attention.However,facing to the nearly unknown huge multi-component materials system,the traditional trial and error method cannot provide sufficient data efficiently.Therefore,an efficient material innovation strategy is significant.The first-principles calculation based on the density functional theory is a powerful tool for both the accurate prediction of material properties and the identification of its underlying thermodynamics and dynamics.At the same time,the advances of computational methods and computer calculation abilities that are orders of magnitude faster than before make the high throughput first-principles calculations popular.At present,the simulation-assisted material design has become a main branch in the material research field and a great many successes have been made.In this article,the advances of the high throughput first-principles calculations are reviewed to show the achievements of the first-principles calculations and guide the future directions of its applications in ceramics.展开更多
The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,rob...The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.展开更多
This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used t...This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used to simulate plasma and guide the diamond-film deposition experiments.Finite-element software COMSOL Multiphysics was used to construct a multiphysics(electromagnetic,plasma,and fluid heat transfer fields)coupling model based on electron collision reaction.Raman spectroscopy and scanning electron microscopy were performed to characterize the experimental growth and validate the model.The simulation results reflected the experimental trends observed.Plasma discharge at the edge of the substrate accelerated due to the increase in△h(△h=0-3 mm),and the values of electron density(n_(c)),molar concentration of H(C_(H)),and molar concentration of CH_(3)(C_(CH_(3)))doubled at the edge(for the special concave sample with△h=−1 mm,the active chemical groups exhibited a decreased molar concentration at the edge of the substrate).At=0-3 mm,a high diamond growth rate and a large diamond grain size were observed at the edge of the substrate,and their values increased with.The uniformity of film thickness decreased with.The Raman spectra of all samples revealed the first-order characteristic peak of dia-mond near 1332 cm^(−1).When△h=−1 mm,tensile stress occurred in all regions of the film.When△h=1-3 mm,all areas in the film ex-hibited compressive stress.展开更多
Various excellent properties of rare earth zirconate and stannate pyrochlores are close related with their native point defects.First-principles calculations are performed to systematically investigate the point defec...Various excellent properties of rare earth zirconate and stannate pyrochlores are close related with their native point defects.First-principles calculations are performed to systematically investigate the point defect mechanism and the oxygen diffusion behavior of A_(2)B_(2)O_(7)(A=La,Ce,Pr,Nd,Pm,Sm,Eu,Gd;B=Zr,Sn).The possible defect complexes and their associated reactions under stoichiometric and nonstoichiometric conditions are explored.The O Frenkel pairs are the most stable defect structure in stoichiometric zirconates,whereas the cation antisite defects are the predominant one in stoichiometric stannates.In the case of BO_(2) excess zirconates and stannates,the BA cation antisite defect with the A vacancy and/or the oxygen interstitial is energetically favorable,whereas the ABantisite defect together with the oxygen vacancy and/or the A interstitial is preferable under the A_(2)O_(3) excess condition.Meanwhile,the maximum point defect concentrations of zirconates are much higher than those of stannates.Furthermore,the oxygen migration barriers are similar in these compounds,ranging in 0.68 eV–0.80 eV.The predicted point defects and oxygen diffusion mechanisms play the critical role in their engineering applications and are expected to guide the future property improvement of pyrochlores through the control of point defects and/or composition.展开更多
Vanadium flow battery （VFB） is a fast going and promising system for large-scale stationary energy stor- age. However, drawbacks such as low power density and narrow temperature window caused by poor catalytic activ...Vanadium flow battery （VFB） is a fast going and promising system for large-scale stationary energy stor- age. However, drawbacks such as low power density and narrow temperature window caused by poor catalytic activity of graphite felt （GF） electrodes limit its worldwide application. In this paper, bismuth, as a low-cost, no-toxic and high-activity electrocatalyst, is used to modify the thermal activated GF （TGF） via a facile hydrothermal method. Bismuth can effectively inhibit the side reaction of hydrogen evolution in wide temperature range, while promoting the V2＋/V3＋ redox reaction. As a result, the VFB assembled with Bi/TGF as negative electrode demonstrates outstanding rate performance under the current density up to 400 mAcm-2, as well as a long-term stability over 600 charging/discharging cycles at a high cur- rent density of 150mA cm-2. Moreover, it also shows excellent temperature adaptability from -10 ℃ to 50 ℃ and high durability for life test at the temperature of 50 ℃.展开更多
The high terrain of the Tibetan Plateau(TP)has a very important impact on the weather and climate of China,East Asia,South Asia,and even the Northern Hemisphere.However,in recent years,the reasons for the decrease in ...The high terrain of the Tibetan Plateau(TP)has a very important impact on the weather and climate of China,East Asia,South Asia,and even the Northern Hemisphere.However,in recent years,the reasons for the decrease in precipitation in the southeastern edge of the plateau have resulted in cutting-edge research regarding the impact of the TP and its surrounding areas on downstream weather and climate.In this study,the spatial and temporal distribution of surface heat flux and precipitation were analyzed from 1998 to 2022,and the possible mechanism of the decrease of precipitation in the eastern edge of the plateau is explored.The main conclusions are as follows:The annual average sensible heat flux in the TP and its east side is positive,with an average of 33.73 W/m^(2).The annual average latent heat flux is positive,with an average of 42.71 W/m^(2).Precipitation has a similar annual average and seasonal distribution,with modest amounts in the northwest and substantial amounts in the southeast.The average annual accumulated precipitation is 670.69 mm.The first mode of the Empirical Orthogonal Function(EOF)shows that sensible heat flux decreases first,then increases,and then finally decreases during 1998–2022.The modes show the opposite trend in middle part of the plateau.The latent heat flux initially decreases,then increases,and finally decreases in the western plateau and near Sichuan Basin.The mode,however,displays the opposite tendency throughout the rest of the region.The precipitation in the north and south sides of the plateau has decreased since 2013,which is consistent with the changing trend of sensible heat flux.In the rest of the region,the change trend is not obvious.The sensible heat of the main body of the plateau and its east side and Sichuan Basin is negatively correlated with precipitation,that is,when sensible heat flux of the main body of the plateau and its east side and Sichuan Basin is more(less),local precipitation is less(more).The latent heat of the main body of the plateau and its east side,Sichuan Basin is positively correlated with precipitation,indicating that when latent heat flux of the main body of the plateau and its east side,Sichuan Basin is more(less),local precipitation is more(less).展开更多
Synergy effect of high stiffness and good damage tolerance is always the focus of the development of novel structural materials.Herein,a new strategy on the future damage tolerant material design is proposed to merge ...Synergy effect of high stiffness and good damage tolerance is always the focus of the development of novel structural materials.Herein,a new strategy on the future damage tolerant material design is proposed to merge the strong covalent bonds into the easy shear deformed A3B metallic box.This goal is realized by studying 126 A3BX phases and establishing a database on their mechanical properties through highthroughput first principles calculations.The combination strategies of A3B metallic box and XA3 octahedra show intensive influences on the expected mechanical properties.The family includes 49 quasi-ductile compounds.Among them,four compounds(Ti3AlN,Mn3CuN,Ti3TlN and Ni3SnN)exhibit excellent damage tolerance and the other six compounds(Mn3NiN,Mn3GaC,Mn3GaN,Mn3SnC,Cr3SnN,Co3AlC)show both damage tolerance and high stiffness.Their competitive high temperature properties are demonstrated through the detailed investigation on the typical cases of Co3Al C and Ti3 Tl N.This study leads a novel direction for the design of the future quasi-ductile and high stiffness ceramics.展开更多
高表达免疫检查点分子程序性死亡受体-配体1(programmed death ligand-1,PD-L1)是肿瘤细胞逃避机体免疫监视的重要途径。PD-L1的表达受到转录水平、翻译水平和翻译后修饰水平等的调控。近年来,PD-L1翻译后修饰逐渐成为PD-L1研究领域的...高表达免疫检查点分子程序性死亡受体-配体1(programmed death ligand-1,PD-L1)是肿瘤细胞逃避机体免疫监视的重要途径。PD-L1的表达受到转录水平、翻译水平和翻译后修饰水平等的调控。近年来,PD-L1翻译后修饰逐渐成为PD-L1研究领域的热点。PD-L1的翻译后修饰包括糖基化、泛素化、磷酸化、棕榈酰化和乙酰化等,可影响PD-L1的稳定性及生物学功能。本文将对该领域的研究进展进行综述,以期为肿瘤免疫治疗研究提供新思路。展开更多
The atomic structural features and the mechanical properties of the Si_(2)BC_(3)N are investigated employ-ing ab-initio calculations.The chemical bonding types and their proportion are clarified.The tetrahedral and tr...The atomic structural features and the mechanical properties of the Si_(2)BC_(3)N are investigated employ-ing ab-initio calculations.The chemical bonding types and their proportion are clarified.The tetrahedral and trigonal configurations,together with their nesting,are identified,which contribute to the flexibil-ity of structural characteristics.The Si-related coordination aggravates the inhomogeneous distribution of chemical bonding and weakens the tetrahedral units.The accompanying polyhedral distortion is quanti-tatively reflected by the bond length and its deviation of polyhedron units.The elastic moduli and the ideal strengths of Si_(2)BC_(3)N are found to be lower than SiC and Si_(3)N_(4),as a result of the weakening effect of coordination Si on tetrahedral units and the existence of easily distorted trigona.The balance between tetrahedral and trigonal features through composition tailor is believed an effective way for the design of Si-B-C-N ceramics for structural applications.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82271419,81901902(to YZ),82202702(to ZW),82202351(to XH),82301550(to LYang),82271418(to XX)the Shanghai Rising-Star Program,No.22QA1408200(to YZ)the Fundamental Research Fundsfor the Central Universities,No.22120220555(to YZ).
文摘In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neurofunctional recovery.Activin A is a critical growth factor necessary for the development of the embryonic nervous system and for maintaining neuronal function in the adult cerebral cortex.It can inhibit excessive autophagy in ischemic stroke to reduce neuronal damage.However,the specific mechanism through which Activin A functions in the spinal cord remains poorly understood.In this study,we administered different concentrations of Activin A to neural stem cells from the spinal cord and found that Activin A stimulated the proliferation and neuronal differentiation of neural stem cells.Then,we established an in vitro oxidative stress model by using hydrogen peroxide to stimulate the neural stem cells-induced neurons.We found that Activin A could reduce apoptosis caused by oxidative stress.Subsequently,we treated a mouse model of spinal cord contusion with intrathecal injection of Activin A.Behavioral and electrophysiological results showed that Activin A promoted recovery of motor function and reconstruction of neural circuits in the model mice.Finally,RNA sequencing indicated that Activin A inhibited autophagy by activating the PI3K/AKT/mTOR pathway and upregulating the expression of synaptogenesis-related factor Sema3A in the spinal cord.These results suggest that Activin A may mediate the excessive autophagic response after spinal cord injury,promote the reconstruction of damaged neural circuits,and restore neurological function in the injured spinal cord.
基金supported,in part,by the National Natural Science Foundation of China(Nos.12372050 and 62088101)the Zhejiang Provincial Natural Science Foundation of China(No.LR20F030003).
文摘In this paper,we investigate analytical numerical iterative strategies for the pursuit-evasion game involving spacecraft with leader–follower information.In the proposed problem,the interplay between two spacecraft gives rise to a dynamic and real-time game,complicated further by the presence of perturbation.The primary challenge lies in crafting control strategies that are both efficient and applicable to real-time game problems within a nonlinear system.To overcome this challenge,we introduce the model prediction and iterative correction technique proposed in model predictive static programming,enabling the generation of strategies in analytical iterative form for nonlinear systems.Subsequently,we proceed by integrating this model predictive framework into a simplified Stackelberg equilibrium formulation,tailored to address the practical complexities of leader–follower pursuit-evasion scenarios.Simulation results validate the effectiveness and exceptional efficiency of the proposed solution within a receding horizon framework.
基金Research Fund of Jianghan University,Grant/Award Number:2021jczx-002Natural Science Foundation of Hubei Province,Grant/Award Number:2024AFB941 and 2024AFD241+1 种基金Wuhan Science and Technology Project,Grant/Award Number:2023010201020448National Natural Science Foundation of China,Grant/Award Number:82204416。
文摘The high morbidity and mortality of colorectal cancer(CRC)is a major challenge in clinical practice.Although a series of alternative research models of CRC have been developed,appropriate orthotopic animal models that reproduce the specific clinical response as well as pathophysiological immune features of CRC are still lacking.In the current study,we constructed a CRC orthotopic xenograft model by implanting the tumor tubes at the colorectum of mice and monitored the model development using bioluminescence imaging.This model successfully recapitulates the clinical chemo-therapy efficacy,including reduced total flux,tumor weight,and the expression of Ki67 after treatment of the first-line chemotherapy regime of CRC(FOLFOX:oxaliplatin and 5-fluorouracil/calcium folinate).The model also reproduced the immunosup-pressive effect of FOLFOX,indicated by decreased infiltration of macrophages and increased Treg cells in tumor.Additionally,the orthotopic xenograft approach may be applied in immunodeficient NCG/NSG mice for constructing patient-derived xeno-grafts,and being used in clinical precision medicine and drug evaluation.We believe the current model is a successful surgical orthotopic xenograft approach for cancer research and deserves to be popularized,which will provide a convenient and efficient platform for in-depth mechanism exploration of CRC and preclinical drug evaluation.
基金funded by the National Natural Science Foundation of China(No.42130309)China Geological Survey(Nos.DD20160030,DD20190050)。
文摘A cluster of serpentinite bodies has been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong'an,western Dabie orogen,central China.Two types of serpentinites are identified on the basis of integrated petrographic,mineralogical and geochemical study.The first type,represented by Yinshanzhai serpentinite complex(Group 1)comprises heterogeneous lithology as a massive serpentinite matrix“intruded”by antigoriteenriched serpentinite lenses.They are both pseudomorphic textured with different mineral assemblages indicating an increasing temperature-pressure condition.Serpentinite matrix(Group 1a)is chemically characterized by high MgO/SiO_(2)and low Al_(2)O_(3)/SiO_(2),Ti and Ca contents,suggesting a depleted mantle wedge origin.The coexistence of compositionally-heterogeneous chromite with highCr^(#)(0.78-0.96)and intermediate-Cr^(#)(0.59-0.70)pristine cores indicates extensive mantle melting.Meanwhile,extremely high Fo olivine relicts(96-97)with considerably higher MnO and lower NiO contents than mantle olivine indicate that they are metamorphic products from serpentine decomposition.Accordingly,we propose that Yinshanzhai serpentinite complex experienced two distinct episodes of hydration.The serpentinite lenses(Group 1b)show higher SiO_(2)and lower MgO concentrations.Nevertheless,the trace elements of groups 1a and 1b are consistent:U-shaped REE patterns,positive Eu anomalies and enrichment of LILE(i.e.,Cs,U)are all identified as forearc properties.They are affected by reducing slab-derived fluids in forearc mantle,with f_(O2)of 1 to 2 logarithmic units below f_(O2)of fayalite-magnetite-quartz buffer(FMQ-2~FMQ-1).The second type is antigorite-serpentinites(Group2)represented by Ximaoshan and Wangchunwan blocks.They are non-pseudomorphic,with no primary framework silicate surviving.Fertile compositions(i.e.,higher Al_(2)O_(3)and Al_(2)O_(3)/SiO_(2),nearly flat REE patterns)and conjoint enrichment of LILE with HFSE suggest melt/rock interaction.Negative Ce,Eu anomalies,and enriched U relative to alkaline elements demonstrate interactions with more oxidized seawater or seafloor fluids(FMQ~FMQ-1).Remarkable Sr negative anomalies may be attributed to Sr release during lizardite/antigorite transition in subduction zone,indicating interaction with low-Sr slab fluids.We propose that Group 2 serpentinites originate either from mantle wedge or abyssal peridotites,refertilized by mantle melts,then hydrated in seafloor or shallow forearc and entrapped into subduction channel.Combined with geochronology and tectonic constraints of associated eclogites in Hong'an terrane,the two types of serpentinites may correlate with subduction of different oceanic basins during the late Paleozoic and/or Proterozoic eras.It raises possibility of defining an ophiolitic setting in Hong'an Orogen for which further evidence is required.
基金supported by the Major Projects in Agricultural Biological Breeding(2022ZD04002)to Xuewei ChenNational Natural Science Foundation of China(32121003 and 32425005)to Xuewei Chen+3 种基金(32172419 and 32372555)to Weitao LiCornerstone Science Foundation through the XPLORER PRIZE and New Cornerstone Investigator Program to Xuewei ChenSichuan Science and Technology Program(2023NSFSC0005)to Xuewei Chen,(2023NSFSC1996)to Weitao Li,(2023NSFSC0155)to Qingqing Hou(2024YFNH0014)to Junjie Yin.
文摘The plant cell wall serves as a barrier in defense against pathogen invasion.However,the specific contribution of cell walls in vascular tissues to plant immunity remains largely unexplored.In this study,we demonstrate that OsCSLC3,a member of the rice cellulose synthase-like(CSL)gene family,is predominantly expressed in vascular tissues and that its overexpression promotes hemicellulose biosynthesis.This enhancement of hemicellulose accumulation is associated with improved disease resistance.Targeted editing of conserved cis-regulatory elements in the OsCSLC35′untranslated region(UTR)showed that deletion of the specific fragment(−575 to−824 bp)elevated OsCSLC3 transcript levels,promoted hemicellulose accumulation,enhanced disease resistance,and improved agronomic traits.Our findings highlight a previously underappreciated role for hemicellulose in plant immunity and demonstrate that precise 5′UTR editing is a promising strategy for improving disease resistance and agronomic traits.
基金supported by the National Natural Science Foundation of China(Nos.52172068,52232004,and 52372059)the Heilongjiang Touyan Team Program and Advanced Talents Scientific Research Foundation of Shenzhen:Yu Zhou,and the Huiyan Action(No.1A423653)the Fundamental Research Funds for the Central Universities.
文摘Metal dopant,such as aluminum,has a significant influence on the performance of amorphous Si_(2)BC_(3)N ceramics and is of particular interest.In this work,the structural responses of amorphous Si_(2)BC_(3)N to incorporating aluminum and related mechanical property modification are investigated employing ab initio molecular dynamics calculations.Considering different Al sources of Al and AlN,two models,i.e.Si_(2)BC_(3)NAl_(0.6)and Si_(2)BC_(3)N_(1.6)Al_(0.6)are constructed,respectively.It is found that the integration of Al engenders the Al-Si,Al-C,and Al-N chemical bonds within the amorphous framework,while the proportions of C-C and Si-Si bonds decrease,indicating that Al promotes a transition from nested polyhedra to independent polyhedral structures.The incorporation of Al induces an increase in tetrahedral arrangements and a decrease in sp^(2)-like trigonal configurations compared to amorphous Si_(2)BC_(3)N.This structural transformation contributes to the enhancement of mechanical characteristics of Si_(2)BC_(3)NAl_(0.6)ceramics.Conversely,Si_(2)BC_(3)N_(1.6)Al_(0.6)shows a marginal increase in tetrahedral configurations,resulting in similar mechanical performance to Si_(2)BC_(3)N.This work elucidates a novel mechanism of local structure transformation in amorphous SiBCN ceramics with incorporated metal elements.
基金supported by the National Natural Science Foundation of China (No. 51602188)the Program for Professor of Special Appointment (Eastern Scholar)by Shanghai Municipal Education Commission (No. TP2015040)
文摘Thermal barrier coating(TBC) materials play important roles in gas turbine engines to protect the Nibased super-alloys from the high temperature airflow damage. High melting point, ultra-low thermal conductivity, large thermal expansion coefficient, excellent damage tolerance and moderate mechanical properties are the main requirements of promising TBC materials. In order to improve the efficiency of jet and/or gas turbine engines, which is the key of improved thrust-to-weight ratios and the energysaving, significant efforts have been made on searching for enhanced TBC materials. Theoretically, density functional theory has been successfully used in scanning the structure and properties of materials, and at the same time predicting the mechanical and thermal properties of promising TBC materials for high and ultrahigh temperature applications, which are validated by subsequent experiments. Experimentally,doping and/or alloying are also widely applied to further decrease their thermal conductivities. Now, the strategy through combining theoretical calculations and experiments on searching for next generation thermal insulator materials is widely adopted. In this review, the common used techniques and the recent advantages on searching for promising TBC materials in both theory and experiments are summarized.
基金the financial support of the National Natural Science Foundation of China(No.51371182)the National Program for the Young Top-notch Professionals and the Fundamental Research Funds for the Central Universities(N170205002)
文摘Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE) can present a methodology to deal with this difficulty, although DOE is not commonly spread in corrosion field. Thus, modeling corrosion of Ni-Cr-Mo-V steel in deep sea environment was performed in order to provide example demonstrating the advantage of DOE. In addition, an artificial neural network mapping using back-propagation method was developed for Ni-Cr-Mo-V steel such that the ANN model can be used to predict polarization curves under different complex sea environments without experimentation. Furthermore, roles of environment factors on corrosion of Ni-Cr-Mo-V steel in deep sea environment were discussed.
基金financially supported by the Natural Science Foundation of Shanghai(No.20ZR1419200)the National Natural Science Foundation of China(No.51972089)the Program for Professor of Special Appointment(Eastern Scholar)by Shanghai Municipal Education Commission(No.TP2015040)。
文摘Recent technical progress in the industry has led to an urgent requirement on new materials with enhanced multi-properties.To meet this multi-property requirement,the materials consisting of three and more elements have attracted increasing attention.However,facing to the nearly unknown huge multi-component materials system,the traditional trial and error method cannot provide sufficient data efficiently.Therefore,an efficient material innovation strategy is significant.The first-principles calculation based on the density functional theory is a powerful tool for both the accurate prediction of material properties and the identification of its underlying thermodynamics and dynamics.At the same time,the advances of computational methods and computer calculation abilities that are orders of magnitude faster than before make the high throughput first-principles calculations popular.At present,the simulation-assisted material design has become a main branch in the material research field and a great many successes have been made.In this article,the advances of the high throughput first-principles calculations are reviewed to show the achievements of the first-principles calculations and guide the future directions of its applications in ceramics.
基金supported by the National Natural Science Foundation of China[grant number 81970987].
文摘The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.
基金supported by the National Key Research and Development Program(No.2019YFE03100200)the State Key Lab for Advanced Metals and Materials,the Fund of National Key Laboratory of Solid-State Microwave Devices and Circuits,the National Natural Science Foundation of China(No.52102034)the Or-ganized Research Fund of North China University of Tech-nology(No.2023YZZKY12).The authors are very grateful for the financial support of these institutions.
文摘This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used to simulate plasma and guide the diamond-film deposition experiments.Finite-element software COMSOL Multiphysics was used to construct a multiphysics(electromagnetic,plasma,and fluid heat transfer fields)coupling model based on electron collision reaction.Raman spectroscopy and scanning electron microscopy were performed to characterize the experimental growth and validate the model.The simulation results reflected the experimental trends observed.Plasma discharge at the edge of the substrate accelerated due to the increase in△h(△h=0-3 mm),and the values of electron density(n_(c)),molar concentration of H(C_(H)),and molar concentration of CH_(3)(C_(CH_(3)))doubled at the edge(for the special concave sample with△h=−1 mm,the active chemical groups exhibited a decreased molar concentration at the edge of the substrate).At=0-3 mm,a high diamond growth rate and a large diamond grain size were observed at the edge of the substrate,and their values increased with.The uniformity of film thickness decreased with.The Raman spectra of all samples revealed the first-order characteristic peak of dia-mond near 1332 cm^(−1).When△h=−1 mm,tensile stress occurred in all regions of the film.When△h=1-3 mm,all areas in the film ex-hibited compressive stress.
基金supported by the National Natural Science Foundation of China(No.51602188)the Program for Professor of Special Appointment(Eastern Scholar)by Shanghai Municipal Education Commission(No.TP2015040)。
文摘Various excellent properties of rare earth zirconate and stannate pyrochlores are close related with their native point defects.First-principles calculations are performed to systematically investigate the point defect mechanism and the oxygen diffusion behavior of A_(2)B_(2)O_(7)(A=La,Ce,Pr,Nd,Pm,Sm,Eu,Gd;B=Zr,Sn).The possible defect complexes and their associated reactions under stoichiometric and nonstoichiometric conditions are explored.The O Frenkel pairs are the most stable defect structure in stoichiometric zirconates,whereas the cation antisite defects are the predominant one in stoichiometric stannates.In the case of BO_(2) excess zirconates and stannates,the BA cation antisite defect with the A vacancy and/or the oxygen interstitial is energetically favorable,whereas the ABantisite defect together with the oxygen vacancy and/or the A interstitial is preferable under the A_(2)O_(3) excess condition.Meanwhile,the maximum point defect concentrations of zirconates are much higher than those of stannates.Furthermore,the oxygen migration barriers are similar in these compounds,ranging in 0.68 eV–0.80 eV.The predicted point defects and oxygen diffusion mechanisms play the critical role in their engineering applications and are expected to guide the future property improvement of pyrochlores through the control of point defects and/or composition.
基金financial support from the National Natural Science Foundation of China (No. 21576154)the Open Fund of The State Key Laboratory of Refractories and Metallurgy (No. G201809)the Shenzhen Basic Research Project (Nos. JCYJ20170412170756603 and JCYJ20170307152754218)
文摘Vanadium flow battery （VFB） is a fast going and promising system for large-scale stationary energy stor- age. However, drawbacks such as low power density and narrow temperature window caused by poor catalytic activity of graphite felt （GF） electrodes limit its worldwide application. In this paper, bismuth, as a low-cost, no-toxic and high-activity electrocatalyst, is used to modify the thermal activated GF （TGF） via a facile hydrothermal method. Bismuth can effectively inhibit the side reaction of hydrogen evolution in wide temperature range, while promoting the V2＋/V3＋ redox reaction. As a result, the VFB assembled with Bi/TGF as negative electrode demonstrates outstanding rate performance under the current density up to 400 mAcm-2, as well as a long-term stability over 600 charging/discharging cycles at a high cur- rent density of 150mA cm-2. Moreover, it also shows excellent temperature adaptability from -10 ℃ to 50 ℃ and high durability for life test at the temperature of 50 ℃.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0103)the National Natural Science Foundation of China(Grant No.42230610)+2 种基金the Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC0217)National key research and development program of China(2017YFC1505702)Scientific Research Project of Chengdu University of Information Technology(KYTZ201721).
文摘The high terrain of the Tibetan Plateau(TP)has a very important impact on the weather and climate of China,East Asia,South Asia,and even the Northern Hemisphere.However,in recent years,the reasons for the decrease in precipitation in the southeastern edge of the plateau have resulted in cutting-edge research regarding the impact of the TP and its surrounding areas on downstream weather and climate.In this study,the spatial and temporal distribution of surface heat flux and precipitation were analyzed from 1998 to 2022,and the possible mechanism of the decrease of precipitation in the eastern edge of the plateau is explored.The main conclusions are as follows:The annual average sensible heat flux in the TP and its east side is positive,with an average of 33.73 W/m^(2).The annual average latent heat flux is positive,with an average of 42.71 W/m^(2).Precipitation has a similar annual average and seasonal distribution,with modest amounts in the northwest and substantial amounts in the southeast.The average annual accumulated precipitation is 670.69 mm.The first mode of the Empirical Orthogonal Function(EOF)shows that sensible heat flux decreases first,then increases,and then finally decreases during 1998–2022.The modes show the opposite trend in middle part of the plateau.The latent heat flux initially decreases,then increases,and finally decreases in the western plateau and near Sichuan Basin.The mode,however,displays the opposite tendency throughout the rest of the region.The precipitation in the north and south sides of the plateau has decreased since 2013,which is consistent with the changing trend of sensible heat flux.In the rest of the region,the change trend is not obvious.The sensible heat of the main body of the plateau and its east side and Sichuan Basin is negatively correlated with precipitation,that is,when sensible heat flux of the main body of the plateau and its east side and Sichuan Basin is more(less),local precipitation is less(more).The latent heat of the main body of the plateau and its east side,Sichuan Basin is positively correlated with precipitation,indicating that when latent heat flux of the main body of the plateau and its east side,Sichuan Basin is more(less),local precipitation is more(less).
基金supported financially by the National Natural Science Foundation of China(No.51602188)the Program for Professor of Special Appointment(Eastern Scholar)by Shanghai Municipal Education Commission(No.TP2015040).
文摘Synergy effect of high stiffness and good damage tolerance is always the focus of the development of novel structural materials.Herein,a new strategy on the future damage tolerant material design is proposed to merge the strong covalent bonds into the easy shear deformed A3B metallic box.This goal is realized by studying 126 A3BX phases and establishing a database on their mechanical properties through highthroughput first principles calculations.The combination strategies of A3B metallic box and XA3 octahedra show intensive influences on the expected mechanical properties.The family includes 49 quasi-ductile compounds.Among them,four compounds(Ti3AlN,Mn3CuN,Ti3TlN and Ni3SnN)exhibit excellent damage tolerance and the other six compounds(Mn3NiN,Mn3GaC,Mn3GaN,Mn3SnC,Cr3SnN,Co3AlC)show both damage tolerance and high stiffness.Their competitive high temperature properties are demonstrated through the detailed investigation on the typical cases of Co3Al C and Ti3 Tl N.This study leads a novel direction for the design of the future quasi-ductile and high stiffness ceramics.
文摘高表达免疫检查点分子程序性死亡受体-配体1(programmed death ligand-1,PD-L1)是肿瘤细胞逃避机体免疫监视的重要途径。PD-L1的表达受到转录水平、翻译水平和翻译后修饰水平等的调控。近年来,PD-L1翻译后修饰逐渐成为PD-L1研究领域的热点。PD-L1的翻译后修饰包括糖基化、泛素化、磷酸化、棕榈酰化和乙酰化等,可影响PD-L1的稳定性及生物学功能。本文将对该领域的研究进展进行综述,以期为肿瘤免疫治疗研究提供新思路。
基金This work was financially supported by the National Natu-ral Science Foundation of China(Nos.52002092,51832002,and 52172071)the Program for Professor of Special Appointment(East-ern Scholar)at Shanghai Institutions of Higher Learning(No.GZ2020012)+1 种基金Key Research Project of Zhejiang Laboratory(No.2021PE0AC02)Heilong Jiang Natural Science Fund for Young Scholars(No.YQ2021E017)。
文摘The atomic structural features and the mechanical properties of the Si_(2)BC_(3)N are investigated employ-ing ab-initio calculations.The chemical bonding types and their proportion are clarified.The tetrahedral and trigonal configurations,together with their nesting,are identified,which contribute to the flexibil-ity of structural characteristics.The Si-related coordination aggravates the inhomogeneous distribution of chemical bonding and weakens the tetrahedral units.The accompanying polyhedral distortion is quanti-tatively reflected by the bond length and its deviation of polyhedron units.The elastic moduli and the ideal strengths of Si_(2)BC_(3)N are found to be lower than SiC and Si_(3)N_(4),as a result of the weakening effect of coordination Si on tetrahedral units and the existence of easily distorted trigona.The balance between tetrahedral and trigonal features through composition tailor is believed an effective way for the design of Si-B-C-N ceramics for structural applications.
