Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltratio...Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltration,depleting their numbers,and reversing their phenotypes to suppress tumor progression,leading to the development of drugs in preclinical and clinical trials.However,the heterogeneous characteristics of TAMs,including their ontogenetic and functional heterogeneity,limit their targeting.Therefore,in-depth exploration of the heterogeneity of TAMs,combined with immune checkpoint therapy or other therapeutic modalities could improve the efficiency of tumor treatment.This review focuses on the heterogeneous ontogeny and function of TAMs,as well as the current development of tumor therapies targeting TAMs and combination strategies.展开更多
In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthet...In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthetic properties,and active compounds to understand the genetic characteristics of S.cathayensis and screen elite germplasms.The leaf shape of 18 offspring from three natural S.cathayensis populations was analyzed to investigate the level of diversity and variation patterns of leaf shape.Furthermore,photosynthetic pigment content,physiological parameters of photosynthesis,and the active compounds in leaves of different shapes were determined.Statistical analysis showed that the leaf shape variation in S.cathayensis indicated a high level of genetic diversity among and within the populations.Cluster analysis showed that the three natural populations formed two clusters,one whose offspring was dominated by entire leaves and another characterized by palmately trifoliate leaves.The differences in photosynthetic characteristics and active compounds of leaves of three different shapes were comprehensively evaluated using principal component analysis.Two principal components with a cumulative contribution rate of 92.768%were extracted,of which the highest comprehensive score was for asymmetrically lobed leaves.The leaf shape in different S.cathayensis germplasms exhibited distinct patterns,and there were some correlations between the photosynthetic properties and active compounds in leaves of different shapes.Thus,the leaf shape can be used to predict active compound content,and in turn,select varieties based on that purpose;it also provides a simple and effective method to classify S.cathayensis germplasms.展开更多
Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment,it is becoming an increasingly common part of microseismic monito...Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment,it is becoming an increasingly common part of microseismic monitoring.The ability to determine an accurate velocity model for the monitored area directly affects the accuracy of microseismic event locations.However,velocity model calibration for location with surface instruments is difficult for several reasons:well log measurements are often inaccurate or incomplete,yielding intractable models;origin times of perforation shots are not always accurate;and the non-uniqueness of velocity models obtained by inversion becomes especially problematic when only perforation shots are used.In this paper,we propose a new approach to overcome these limitations.We establish an initial velocity model from well logging data,and then use the root mean square(RMS) error of double-difference arrival times as a proxy measure for the misfit between the well log velocity model and the true velocity structure of the medium.Double-difference RMS errors are reduced by using a very fast simulated annealing for model perturbance,and a sample set of double-difference RMS errors is then selected to determine an empirical threshold.This threshold value is set near the minimum RMS of the selected samples,and an appropriate number of travel times within the threshold range are chosen.The corresponding velocity models are then used to relocate the perforation-shot.We use the velocity model with the smallest relative location errors as the basis for microseismic location.Numerical analysis with exact input velocity models shows that although large differences exist between the calculated and true velocity models,perforation shots can still be located to their actual positions with the proposed technique;the location inaccuracy of the perforation is <2 m.Further tests on field data demonstrate the validity of this technique.展开更多
Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)condi...Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)conditions were investigated.The results of mechanical properties show that with Yb addition,the microhardness and the ultimate tensile strength(UTS)of the tested alloys are significantly increased despite a slight decrease in tensile elongation in both T4 and T6 conditions.Especially,after the T6 treatment,the microhardness and the UTS of the samples were further improved,which was mainly attributed to the precipitation strengthening.The biocorrosion behaviors of the tested alloys were studied using electrochemical examinations and immersion tests.The results indicate that the biocorrosion resistance of the tested alloys is significantly improved by Yb addition in both T4 and T6 conditions.Although the corrosion resistance was slightly deteriorated after T6 treatment,the aged ZK60-2.0 Yb alloy still exhibited a favorable corrosion behavior,which was mainly ascribed to the corrosion barrier effect of a more compact and uniform protective film induced by the dispersed nano-scale precipitates.Electrochemical measurements also confirmed these observations.Given the favorable comprehensive performance in mechanical and biocorrosion behaviors,the T6 treated ZK60-2.0 Yb alloy may be considered as a promising candidate for biomedical applications.展开更多
To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of t...To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of the generalized DSR is analyzed and flexibility models for various DSR are constructed.Second,owing to the characteristics of small capacity but large-scale,an outer approximation is proposed to describe the aggregate flexibility of DSR.Then,the optimal flexibility dispatch model of DSR based on the Stackelberg game is established and a decentralized solution algorithm is designed to obtain the Stackelberg equilibrium.Finally,the actual data are utilized for the case study and the results show that,compared to the traditional centralized optimization method,the proposed optimal flexibility dispatch method can not only reduce the net load variability of the DSR aggregator but is beneficial for all DSR owners,which is more suitable for practical applications.展开更多
Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition o...Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition on the microstructure and mechanical properties of pure Mg matrix remains uncertain to date.In this work,the effects of Yb concentration on the texture development and tensile properties of pure Mg matrix during hot extrusion and the subsequent annealing were systematically investigated.The results revealed that the constitutional supercooling induced by Yb addition refined the as-cast microstructure but exerted a negligible effect on the original columnar grain morphology.When extruded at 300°C,the dynamic recrystallization(DRX)process was considerably retarded.The in-grain misorientation axes(IGMA)analysis combined with TEM observation indicated that non-basal slips operated with increasing Yb concentration.Specifically,the prismaticslip should be robustly activated in Mg-1.0 Yb extrudate,promoting the formation of the texture with{10?10}plane normal to the extrusion direction(ED),while for the Mg?2.0 Yb counterpart,the increased activity of pyramidal<c+a>slip and the relaxation of basal/<c+a>dislocations generated an ED-tilted texture component.The preferential grain growth dominated the subsequent annealing texture development at 400°C when a comparable grain size was achieved.An obvious ED-tilted texture intensity with the peak around<12 13>was observed in Mg-2.0 Yb alloy,which was primarily caused by grains with the basal orientation vanished and with the non-basal orientations intensified due to a higher concentration of Yb solute.Favored by the grain refinement,the Mg-2.0 Yb extrudate exhibited a high tensile yield strength of 304±3.5 MPa,while the subsequently annealed counterpart presented a favorable elongation to failure of 14.8±1.2%,which mainly due to the homogeneous grain structure,weak ED-tilted texture,and dissolution of coarse phases after high-temperature annealing.展开更多
This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain ...This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.展开更多
In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutio...In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutions by L-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag(Ⅰ), and surfactants of nonionic(polyethylene glycol, PEG), anionic(sodium dodecyl sulfate, SDS), and cationic(cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(Ⅰ) to reinforce the reduction of Au(Ⅲ) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.展开更多
This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficient...This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficients of the parameter part of the Varying Index Coefficient Model (VICM), while the unknown function part uses the B-spline to expand. Moreover, we combine the above two estimation methods under the assumption of high-dimensional data. The results of data simulation and empirical analysis show that for the varying index coefficient model, the re-adjusted cross-validation method is better in terms of accuracy and stability than traditional methods based on ordinary least squares.展开更多
When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna....When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna. The thermal field of biological tissue produced by microwave radiative antenna is investigated in this paper. The distribution of thermal field and specific absorption rate (SAR) of invasive coaxial-slot antenna in the frequency of 2450 MHz are obtained by the technique of finite element analysis. According to the experiment of heating the ex vivo pork liver by this kind of antenna, the result concordant with the theory is obtained. Therefore, it is suggested that this research could be a reference for clinical therapy and operation scheme.展开更多
Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to si...Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to single metals and their metal alloys with random atomic arrangements.Herein,we report a simple solid-phase synthesis of novel mesoporous intermetallic noble metal-nonmetal(MI-PtX_(2))nanoparticles with hierarchical orderliness as highly efficient electrocatalysts for hydrogen evolution reaction(HER).The synthesis relies on a Pt-to-PtX_(2) evolution with mesoporous Pt confined in thermally stable KIT-6(Korea Advanced Institute of Science and Technology-6)as the concurrent template.Meanwhile,the method could be extended readily to control structures and compositions of mesoporous intermetallic nanoparticles such as hollow structures and ternary MI-PtMP_(2).Samples featured rhombic dodecahedral morphology,ordered gyroid mesostructure,and cubic/hexagonal intermetallic phase,producing abundant undercoordinated sites and optimized surface electronic structures.These features kinetically accelerate H_(2)O dissociation to remarkably enhance electrocatalytic HER performance.The optimum MI-PtP_(2) disclosed ultrahigh mass/specific activity(3.31 A mg_(pt)^(−1)/7.75 mA cm_(pt)^(−2))and superior stability(only 15.2%of mass activity loss after an accelerated durability test for 30,000 cycles),suppressing the reported electrocatalysts.Our work opens up new opportunities for designing and synthesizing novel hierarchically ordered mesoporous electrocatalysts with targeted functions for a variety of applications.展开更多
DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of di...DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of diseases caused by replication.Here,we design a computational approach named iORI-Epi to recognize ORis by incorporating epigenome-based features,sequencebased features,and 3D genome-based features.The iORI-Epi displays excellent robustness and generalization ability on both training datasets and independent datasets of K562 cell line.Further experiments confrm that iORI-Epi is highly scalable in other cell lines(MCF7 and HCT116).We also analyze and clarify the regulatory role of epigenomic marks,DNA motifs,and chromatin interaction in DNA replication initiation of eukaryotic genomes.Finally,we discuss gene enrichment pathways from the perspective of ORIs in different replication timing states and heuristically dissect the effect of promoters on replication initiation.Our computational methodology is worth extending to ORI identification in other eukaryotic species.展开更多
Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to...Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to reveal the extraction regularity, optimize production-process and guide the use of this new extraction system, the extraction of Nd(Ⅲ) in chloride medium with HEH/EHP saponified by magnesium bicarbonate solution was investigated with the self-designed constant interfacial area cell. Besides, the effects of stirring rate, temperature, specific interfacial area and concentration of Mg-HEH/EHP on the extraction rate of Nd(Ⅲ) were systematically investigated. Results show that, the rate of extraction is governed by both diffusion and chemical reaction, and the extraction reaction takes place at the interface. The apparent activation energy of the extraction reaction is 16.88 kJ/mol. The corresponding rate equation is deduced. The mechanisms and rate-determining step are speculated based on interfacial reaction models, which is consistent with the experimental results.展开更多
Porous features of mesoporous metal nanocrystals are critically important for their applications in catalysis,sorption,and biomedicine and bioimaging.However,precisely engineering porous architectures of mesoporous me...Porous features of mesoporous metal nanocrystals are critically important for their applications in catalysis,sorption,and biomedicine and bioimaging.However,precisely engineering porous architectures of mesoporous metals is still highly challenging.Herein,we report a facile soft-templating strategy to precisely engineer porous architectures of multicomponent PdCuBP mesoporous nanospheres(MSs)by using the surfactants with different amphiphilic features.Three kinds of MSs with distinct porous architectures,including three-dimensional(3D)opened/interconnected dendritic mesopores(dMSs),one-dimensional(1D)cylindered mesopores(cMSs),and zero-dimensional(0D)spherical mesopores(sMSs),are prepared.This surfactant-templating method is generally extended to regulate elemental compositions of multicomponent MSs.The resultant Pd-based MSs have been evaluated as the electrocatalysts for ethanol oxidation reaction(EOR).Our results show that quaternary PdCuBP dMSs display remarkably high catalytic activity and better stability for electrocatalytic EOR,compared to those of multicomponent MSs with other porous architectures and less elemental compositions.Mechanism studies reveal that PdCuBP dMSs combine multiple structural and compositional advantages,which kinetically accelerate the electron/mass transfers and also improve the tolerances to poisoning intermediates.We believe that the porous architecture engineering in mesoporous metal electrocatalysts will present a new way to design highly efficient electrocatalysts with desired porous systems and explore their relations towards(electro)catalysis.展开更多
Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were i...Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were investigated for pure copper and pure chromium cathodes.The discharging homogeneity was improved with the increase of chromium content in the cathodes,which was attributed to the formed chromic oxide layer.The CuCr50 cathodes exhibited the lowest ablation rate with a reduction of 27.0%compared to the copper cathodes.The chromic oxide formed in the pit protected the bottom matrix,leading to a homogeneous ablation process.The mechanism for the improved homogeneous ablation behaviors of the CuCr50 cathodes was proposed and featured by the suppression of deep pits and the dispersion of arc foot.Future attention will be focused on designing composite cathodes with an anti-ablation surface layer and a good conductive matrix.展开更多
报道了一种用于电化学乙醇氧化反应(EOR)的三元贵金属-类金属-非金属合金纳米线催化剂的合理设计和合成.两亲性F127组装的柱状胶束作为液相软模板,合成了三元钯-硼-磷纳米线(Pd BP NWs@N-G)合金催化剂.研究发现,B和P的合金化既可以调节P...报道了一种用于电化学乙醇氧化反应(EOR)的三元贵金属-类金属-非金属合金纳米线催化剂的合理设计和合成.两亲性F127组装的柱状胶束作为液相软模板,合成了三元钯-硼-磷纳米线(Pd BP NWs@N-G)合金催化剂.研究发现,B和P的合金化既可以调节Pd催化剂的电子态,又可以在催化剂中引入新的功能性;而氮掺杂石墨烯负载的超细纳米线暴露了更多的电催化活性中心,并加速了电子/物质传质.因此,PdBPNWs@N-G的组分和结构的协同作用促进了CO基中间体的移除,进而显著提高电催化EOR的性能.PdBPNWs@N-G的EOR质量活性达到4.15 A mgPd^-1,并表现出了良好的稳定性和催化性能再生的特性,远远优于已报道的单金属Pd基纳米催化剂.这种设计合成方法具有很好的普遍性,可以扩展到更复杂的多组分纳米线催化剂体系(例如四元PdCuBPNWs@N-G).展开更多
A kind of leaching residue generated during high pressure acid leaching of laterite nickel ore is creatively prepared as blast furnace charge for ironmaking.Results show that the briquettes with uniform shape,compress...A kind of leaching residue generated during high pressure acid leaching of laterite nickel ore is creatively prepared as blast furnace charge for ironmaking.Results show that the briquettes with uniform shape,compressive strength higher than 72.3 N/pellet,and cracking temperature over 400℃can be obtained by the non-binder briquetting with water content of 12.2 wt.%and pressure of 30 MPa.After preheating at 975℃for 12 min and roasting at 1225℃for 15 min,the strength of the roasted briquettes can reach 2815 N/pellet,and the iron grade is 59.27 wt.%.And the sulfur content can be simultaneously reduced to 0.067 wt.%.The obtained briquettes achieve adequate reducibility index,reduction degradation index,reduction swelling index,softening and melting temperatures,which are suitable for blast furnace ironmaking.The results show that this method cannot only effectively treat the leaching residue to reduce the risk of environmental pollution,but also realize the utilization of leaching residue.展开更多
Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)catalysis.Despites numerous achievements in ...Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)catalysis.Despites numerous achievements in past two decades,noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable drawbacks.Here,we report a general strategy for fast,scalable,and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm,ranging from bimetallic PdM(PdFe,PdCo,PdNi,PdCu,PdZn,PdRu,PdRh,PdAg,PdCd,PdIr,PdPt,PdAu)and binary PdS/PdP NWs,to trimetallic PdM1M2 NWs(PdAuCu,PdCoNi,PdCuZn,PdCuNi,PdAgCu,PdAuCu,PdRuAg,PdAuRu,and PdPtAu),and to tetrametallic PdM1M2M3 NWs(PdAuAgCu,PdCoCuNi,PdAuCuNi,PdPtAuCu,and PdIrPtAu).The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium chloride.As-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies,which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction(EOR).Among them,tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mg-1 Pd and a low activation energy of 13.1 kJ mol^-1,both of which are much better than its counterpart catalysts alloyed with less elements.This work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.展开更多
Mesoporous single crystals have unique potential in catalysis,but remain unexplored owing to the enormous synthetic challenge that they pose.Herein,we report a facile soft-template method to prepare palladium(Pd)and P...Mesoporous single crystals have unique potential in catalysis,but remain unexplored owing to the enormous synthetic challenge that they pose.Herein,we report a facile soft-template method to prepare palladium(Pd)and Pd alloy nanocubes with single-crystallinity and abundant mesoporosity.The successful formation of these exotic nanostructures essentially relies on the cointroduction of cetyltrimethylammonium chloride as the surfactant template and extra Cl^(−) ions as the facet-selective capping agent under well controlled experimental conditions.Thanks to their large surface areas and penetrating mesoporous channels,our products exhibit a great performance for electrochemical CO_(2) reduction.The best sample from alloying palladium with copper enables the efficient formate production with high selectivity(90∼100%)over a broad potential range,and great stability even under the working potential as cathodic as −0.5 V versus a reversible hydrogen electrode.These performance metrics are far superior to previous Pd-based materials,and underscore the structural advantages of our products.展开更多
基金This work was supported by the National Natural Science Foundation of China(82003018).
文摘Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltration,depleting their numbers,and reversing their phenotypes to suppress tumor progression,leading to the development of drugs in preclinical and clinical trials.However,the heterogeneous characteristics of TAMs,including their ontogenetic and functional heterogeneity,limit their targeting.Therefore,in-depth exploration of the heterogeneity of TAMs,combined with immune checkpoint therapy or other therapeutic modalities could improve the efficiency of tumor treatment.This review focuses on the heterogeneous ontogeny and function of TAMs,as well as the current development of tumor therapies targeting TAMs and combination strategies.
基金funded by Changsha Natural Science Foundation(Grant No.kq2202356)Hunan Forestry Science and Technology Innovation Plan Project(Grant No.XLK202106-2).
文摘In the present study,the variation patterns of leaf shape in different populations of individual Semiliquidambar cathayensis plants were analyzed to investigate the relationship among leaf shape variation,photosynthetic properties,and active compounds to understand the genetic characteristics of S.cathayensis and screen elite germplasms.The leaf shape of 18 offspring from three natural S.cathayensis populations was analyzed to investigate the level of diversity and variation patterns of leaf shape.Furthermore,photosynthetic pigment content,physiological parameters of photosynthesis,and the active compounds in leaves of different shapes were determined.Statistical analysis showed that the leaf shape variation in S.cathayensis indicated a high level of genetic diversity among and within the populations.Cluster analysis showed that the three natural populations formed two clusters,one whose offspring was dominated by entire leaves and another characterized by palmately trifoliate leaves.The differences in photosynthetic characteristics and active compounds of leaves of three different shapes were comprehensively evaluated using principal component analysis.Two principal components with a cumulative contribution rate of 92.768%were extracted,of which the highest comprehensive score was for asymmetrically lobed leaves.The leaf shape in different S.cathayensis germplasms exhibited distinct patterns,and there were some correlations between the photosynthetic properties and active compounds in leaves of different shapes.Thus,the leaf shape can be used to predict active compound content,and in turn,select varieties based on that purpose;it also provides a simple and effective method to classify S.cathayensis germplasms.
基金supported by the National Natural Science Foundation of China(No.41074074)
文摘Because surface-based monitoring of hydraulic fracturing is not restricted by borehole geometry or the difficulties in maintaining subsurface equipment,it is becoming an increasingly common part of microseismic monitoring.The ability to determine an accurate velocity model for the monitored area directly affects the accuracy of microseismic event locations.However,velocity model calibration for location with surface instruments is difficult for several reasons:well log measurements are often inaccurate or incomplete,yielding intractable models;origin times of perforation shots are not always accurate;and the non-uniqueness of velocity models obtained by inversion becomes especially problematic when only perforation shots are used.In this paper,we propose a new approach to overcome these limitations.We establish an initial velocity model from well logging data,and then use the root mean square(RMS) error of double-difference arrival times as a proxy measure for the misfit between the well log velocity model and the true velocity structure of the medium.Double-difference RMS errors are reduced by using a very fast simulated annealing for model perturbance,and a sample set of double-difference RMS errors is then selected to determine an empirical threshold.This threshold value is set near the minimum RMS of the selected samples,and an appropriate number of travel times within the threshold range are chosen.The corresponding velocity models are then used to relocate the perforation-shot.We use the velocity model with the smallest relative location errors as the basis for microseismic location.Numerical analysis with exact input velocity models shows that although large differences exist between the calculated and true velocity models,perforation shots can still be located to their actual positions with the proposed technique;the location inaccuracy of the perforation is <2 m.Further tests on field data demonstrate the validity of this technique.
基金This work was supported by the National Natural Science Foundation of China(grant number 51975484 and 51605392)Fundamental Research Funds for the Central Universities(grant number XDJK2020B001).
文摘Mechanical properties and biocorrosion behaviors in simulated body fluid(SBF)of newly developed Mg-5.8 Zn-0.5 Zr-x Yb(ZK60-X Yb,x=0,1.0,2.0wt%)magnesium alloys in the solution-treated(T4)and artificially-aged(T6)conditions were investigated.The results of mechanical properties show that with Yb addition,the microhardness and the ultimate tensile strength(UTS)of the tested alloys are significantly increased despite a slight decrease in tensile elongation in both T4 and T6 conditions.Especially,after the T6 treatment,the microhardness and the UTS of the samples were further improved,which was mainly attributed to the precipitation strengthening.The biocorrosion behaviors of the tested alloys were studied using electrochemical examinations and immersion tests.The results indicate that the biocorrosion resistance of the tested alloys is significantly improved by Yb addition in both T4 and T6 conditions.Although the corrosion resistance was slightly deteriorated after T6 treatment,the aged ZK60-2.0 Yb alloy still exhibited a favorable corrosion behavior,which was mainly ascribed to the corrosion barrier effect of a more compact and uniform protective film induced by the dispersed nano-scale precipitates.Electrochemical measurements also confirmed these observations.Given the favorable comprehensive performance in mechanical and biocorrosion behaviors,the T6 treated ZK60-2.0 Yb alloy may be considered as a promising candidate for biomedical applications.
基金supported by Science and Technology Project of State Grid Hebei Electric Power Company(SGHE0000DKJS2000228)
文摘To promote the utilization of renewable energy,such as photovoltaics,this paper proposes an optimal flexibility dispatch method for demand-side resources(DSR)based on the Stackelberg game theory.First,the concept of the generalized DSR is analyzed and flexibility models for various DSR are constructed.Second,owing to the characteristics of small capacity but large-scale,an outer approximation is proposed to describe the aggregate flexibility of DSR.Then,the optimal flexibility dispatch model of DSR based on the Stackelberg game is established and a decentralized solution algorithm is designed to obtain the Stackelberg equilibrium.Finally,the actual data are utilized for the case study and the results show that,compared to the traditional centralized optimization method,the proposed optimal flexibility dispatch method can not only reduce the net load variability of the DSR aggregator but is beneficial for all DSR owners,which is more suitable for practical applications.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51975484 and 51605392)the Natural Science Foundation Project of CQ CSTC(Grant No.cstc2020jcyj-msxm X0170)the Fundamental Research Funds for the Central Universities(Grant No.XDJK2020B001)。
文摘Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition on the microstructure and mechanical properties of pure Mg matrix remains uncertain to date.In this work,the effects of Yb concentration on the texture development and tensile properties of pure Mg matrix during hot extrusion and the subsequent annealing were systematically investigated.The results revealed that the constitutional supercooling induced by Yb addition refined the as-cast microstructure but exerted a negligible effect on the original columnar grain morphology.When extruded at 300°C,the dynamic recrystallization(DRX)process was considerably retarded.The in-grain misorientation axes(IGMA)analysis combined with TEM observation indicated that non-basal slips operated with increasing Yb concentration.Specifically,the prismaticslip should be robustly activated in Mg-1.0 Yb extrudate,promoting the formation of the texture with{10?10}plane normal to the extrusion direction(ED),while for the Mg?2.0 Yb counterpart,the increased activity of pyramidal<c+a>slip and the relaxation of basal/<c+a>dislocations generated an ED-tilted texture component.The preferential grain growth dominated the subsequent annealing texture development at 400°C when a comparable grain size was achieved.An obvious ED-tilted texture intensity with the peak around<12 13>was observed in Mg-2.0 Yb alloy,which was primarily caused by grains with the basal orientation vanished and with the non-basal orientations intensified due to a higher concentration of Yb solute.Favored by the grain refinement,the Mg-2.0 Yb extrudate exhibited a high tensile yield strength of 304±3.5 MPa,while the subsequently annealed counterpart presented a favorable elongation to failure of 14.8±1.2%,which mainly due to the homogeneous grain structure,weak ED-tilted texture,and dissolution of coarse phases after high-temperature annealing.
基金supported by the Independent Innovation Foundation of Tianjin University (No.2016XZC-0028)
文摘This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.
基金supported by the Independent Innovation Foundation of Tianjin University (No. 2016XZC-0028)
文摘In this paper, we describe a simple and efficient synthesis of gold nanoparticles(GNPs) of various shapes(spherical, rod-like, hexagonal, truncated triangular, and triangular) using Au(Ⅲ) reduction in aqueous solutions by L-tryptophan. We evaluated the influences of reaction temperature, foreign metal ions Ag(Ⅰ), and surfactants of nonionic(polyethylene glycol, PEG), anionic(sodium dodecyl sulfate, SDS), and cationic(cetyltrimethyl ammonium bromide, CTAB) on GNPs synthesis. We characterized the resultant GNPs using UV–visible adsorption spectroscopy, transmission electron microscopy/high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, selected-area electron diffraction, and Fourier-transform infrared spectroscopy. We fabricated the variously sized GNPs by controlling the rate of the reduction of gold ions in aqueous solution by varying the reaction temperature: the higher the temperature, the smaller the gold nanospheres. We found the existence of Ag(Ⅰ) to reinforce the reduction of Au(Ⅲ) and to correspond with the appearance of some amorphous bimetallic Au/Ag nanoparticles. Additionally, we found the presence of surfactants to greatly influence the shape of the formed GNPs, especially the presence of CTAB, which results in the anisotropic growth of gold nanocrystals into hexagonal, truncated triangular, and triangular nanoplates. In addition, with the increase in CTAB concentration, we found the amount of gold nanoplates to first increase and then decrease. Finally, we performed preliminary explorations of the reduction process and morphological evolution to propose possible corresponding reduction and morphological evolution pathways.
文摘This paper studies the re-adjusted cross-validation method and a semiparametric regression model called the varying index coefficient model. We use the profile spline modal estimator method to estimate the coefficients of the parameter part of the Varying Index Coefficient Model (VICM), while the unknown function part uses the B-spline to expand. Moreover, we combine the above two estimation methods under the assumption of high-dimensional data. The results of data simulation and empirical analysis show that for the varying index coefficient model, the re-adjusted cross-validation method is better in terms of accuracy and stability than traditional methods based on ordinary least squares.
文摘When the technique of invasive microwave hyperthermia is applied to cancer treating, the distribution of microwave thermal field and the effect of the therapy are determined by the type of microwave radiative antenna. The thermal field of biological tissue produced by microwave radiative antenna is investigated in this paper. The distribution of thermal field and specific absorption rate (SAR) of invasive coaxial-slot antenna in the frequency of 2450 MHz are obtained by the technique of finite element analysis. According to the experiment of heating the ex vivo pork liver by this kind of antenna, the result concordant with the theory is obtained. Therefore, it is suggested that this research could be a reference for clinical therapy and operation scheme.
文摘Ordered mesoporous noble metals(NMs)have displayed unique catalytic and electrocatalytic performance distinctive from traditional nanoparticles.Despite great efforts,the range of mesoporous NMs is mainly limited to single metals and their metal alloys with random atomic arrangements.Herein,we report a simple solid-phase synthesis of novel mesoporous intermetallic noble metal-nonmetal(MI-PtX_(2))nanoparticles with hierarchical orderliness as highly efficient electrocatalysts for hydrogen evolution reaction(HER).The synthesis relies on a Pt-to-PtX_(2) evolution with mesoporous Pt confined in thermally stable KIT-6(Korea Advanced Institute of Science and Technology-6)as the concurrent template.Meanwhile,the method could be extended readily to control structures and compositions of mesoporous intermetallic nanoparticles such as hollow structures and ternary MI-PtMP_(2).Samples featured rhombic dodecahedral morphology,ordered gyroid mesostructure,and cubic/hexagonal intermetallic phase,producing abundant undercoordinated sites and optimized surface electronic structures.These features kinetically accelerate H_(2)O dissociation to remarkably enhance electrocatalytic HER performance.The optimum MI-PtP_(2) disclosed ultrahigh mass/specific activity(3.31 A mg_(pt)^(−1)/7.75 mA cm_(pt)^(−2))and superior stability(only 15.2%of mass activity loss after an accelerated durability test for 30,000 cycles),suppressing the reported electrocatalysts.Our work opens up new opportunities for designing and synthesizing novel hierarchically ordered mesoporous electrocatalysts with targeted functions for a variety of applications.
基金supported by a grant from the National Natural Science Foundation of China(62172078)the Science Fund for Distinguished Young Scholars of Sichuan Province(20JCQN0262)+1 种基金supported by an Singapore Ministry of Education Tier I(grant R86/21)awarded to Melissa J.Fullwoodsupported by the China Scholarship Council to visit Nanyang Technological University.
文摘DNA replication initiation is a complex process involving various genetic and epigenomic signatures.The correct identification of replication origins(ORIs)could provide important clues for the study of a variety of diseases caused by replication.Here,we design a computational approach named iORI-Epi to recognize ORis by incorporating epigenome-based features,sequencebased features,and 3D genome-based features.The iORI-Epi displays excellent robustness and generalization ability on both training datasets and independent datasets of K562 cell line.Further experiments confrm that iORI-Epi is highly scalable in other cell lines(MCF7 and HCT116).We also analyze and clarify the regulatory role of epigenomic marks,DNA motifs,and chromatin interaction in DNA replication initiation of eukaryotic genomes.Finally,we discuss gene enrichment pathways from the perspective of ORIs in different replication timing states and heuristically dissect the effect of promoters on replication initiation.Our computational methodology is worth extending to ORI identification in other eukaryotic species.
基金Project supported by National Science and Technology Support Program of China(2015BAB16B03,2015BAB16B02)National Natural Science Foundation of China(51674037,51504034)
文摘Magnesium bicarbonate solution is considered as an environmentally friendly extractant saponification agent for the solvent extraction of rare earth elements due to its advantage of minimum water pollution.In order to reveal the extraction regularity, optimize production-process and guide the use of this new extraction system, the extraction of Nd(Ⅲ) in chloride medium with HEH/EHP saponified by magnesium bicarbonate solution was investigated with the self-designed constant interfacial area cell. Besides, the effects of stirring rate, temperature, specific interfacial area and concentration of Mg-HEH/EHP on the extraction rate of Nd(Ⅲ) were systematically investigated. Results show that, the rate of extraction is governed by both diffusion and chemical reaction, and the extraction reaction takes place at the interface. The apparent activation energy of the extraction reaction is 16.88 kJ/mol. The corresponding rate equation is deduced. The mechanisms and rate-determining step are speculated based on interfacial reaction models, which is consistent with the experimental results.
基金supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20191366 and BK20180723),Priority Academic Program Development of Jiangsu Higher Education Institutions,National and Local Joint Engineering Research Center of Biomedical Functional Materials.
文摘Porous features of mesoporous metal nanocrystals are critically important for their applications in catalysis,sorption,and biomedicine and bioimaging.However,precisely engineering porous architectures of mesoporous metals is still highly challenging.Herein,we report a facile soft-templating strategy to precisely engineer porous architectures of multicomponent PdCuBP mesoporous nanospheres(MSs)by using the surfactants with different amphiphilic features.Three kinds of MSs with distinct porous architectures,including three-dimensional(3D)opened/interconnected dendritic mesopores(dMSs),one-dimensional(1D)cylindered mesopores(cMSs),and zero-dimensional(0D)spherical mesopores(sMSs),are prepared.This surfactant-templating method is generally extended to regulate elemental compositions of multicomponent MSs.The resultant Pd-based MSs have been evaluated as the electrocatalysts for ethanol oxidation reaction(EOR).Our results show that quaternary PdCuBP dMSs display remarkably high catalytic activity and better stability for electrocatalytic EOR,compared to those of multicomponent MSs with other porous architectures and less elemental compositions.Mechanism studies reveal that PdCuBP dMSs combine multiple structural and compositional advantages,which kinetically accelerate the electron/mass transfers and also improve the tolerances to poisoning intermediates.We believe that the porous architecture engineering in mesoporous metal electrocatalysts will present a new way to design highly efficient electrocatalysts with desired porous systems and explore their relations towards(electro)catalysis.
基金This work is financially supported by the National Key R&D Program of China(No.2017YFB1200800)the National Natural Science Foundation of China(Nos.11725210,11572281)the Fundamental Research Funds for the Central Universities(No.2018XZZX001-05)。
文摘Cathode ablation is one of the dominant limitations for extending the maximum operating time of arc heaters.In this work,the arc ablation behaviors and mechanisms of commercial CuCr10,CuCr25,and CuCr50 cathodes were investigated for pure copper and pure chromium cathodes.The discharging homogeneity was improved with the increase of chromium content in the cathodes,which was attributed to the formed chromic oxide layer.The CuCr50 cathodes exhibited the lowest ablation rate with a reduction of 27.0%compared to the copper cathodes.The chromic oxide formed in the pit protected the bottom matrix,leading to a homogeneous ablation process.The mechanism for the improved homogeneous ablation behaviors of the CuCr50 cathodes was proposed and featured by the suppression of deep pits and the dispersion of arc foot.Future attention will be focused on designing composite cathodes with an anti-ablation surface layer and a good conductive matrix.
基金supported by Natural Science Foundation of Jiangsu Province(BK20180723,BK20191366)Jiangsu Specially Appointed Professor Plan+2 种基金the Program of Jiangsu Province Innovation TeamPriority Academic Program Development of Jiangsu Higher Education InstitutionsNational and Local Joint Engineering Research Center of Biomedical Functional Materials。
文摘报道了一种用于电化学乙醇氧化反应(EOR)的三元贵金属-类金属-非金属合金纳米线催化剂的合理设计和合成.两亲性F127组装的柱状胶束作为液相软模板,合成了三元钯-硼-磷纳米线(Pd BP NWs@N-G)合金催化剂.研究发现,B和P的合金化既可以调节Pd催化剂的电子态,又可以在催化剂中引入新的功能性;而氮掺杂石墨烯负载的超细纳米线暴露了更多的电催化活性中心,并加速了电子/物质传质.因此,PdBPNWs@N-G的组分和结构的协同作用促进了CO基中间体的移除,进而显著提高电催化EOR的性能.PdBPNWs@N-G的EOR质量活性达到4.15 A mgPd^-1,并表现出了良好的稳定性和催化性能再生的特性,远远优于已报道的单金属Pd基纳米催化剂.这种设计合成方法具有很好的普遍性,可以扩展到更复杂的多组分纳米线催化剂体系(例如四元PdCuBPNWs@N-G).
基金supported by the National Natural Science Foundation of China(51974371)the National Key R&D Program(No.2018YFC1900605)the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University(CSUZC202031).
文摘A kind of leaching residue generated during high pressure acid leaching of laterite nickel ore is creatively prepared as blast furnace charge for ironmaking.Results show that the briquettes with uniform shape,compressive strength higher than 72.3 N/pellet,and cracking temperature over 400℃can be obtained by the non-binder briquetting with water content of 12.2 wt.%and pressure of 30 MPa.After preheating at 975℃for 12 min and roasting at 1225℃for 15 min,the strength of the roasted briquettes can reach 2815 N/pellet,and the iron grade is 59.27 wt.%.And the sulfur content can be simultaneously reduced to 0.067 wt.%.The obtained briquettes achieve adequate reducibility index,reduction degradation index,reduction swelling index,softening and melting temperatures,which are suitable for blast furnace ironmaking.The results show that this method cannot only effectively treat the leaching residue to reduce the risk of environmental pollution,but also realize the utilization of leaching residue.
基金the Natural Science Foundation of Jiangsu Province(BK20150969,BK20191366)Jiangsu Specially Appointed Professor Plan+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National and Local Joint Engineering Research Center of Biomedical Functional Materials。
文摘Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)catalysis.Despites numerous achievements in past two decades,noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable drawbacks.Here,we report a general strategy for fast,scalable,and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm,ranging from bimetallic PdM(PdFe,PdCo,PdNi,PdCu,PdZn,PdRu,PdRh,PdAg,PdCd,PdIr,PdPt,PdAu)and binary PdS/PdP NWs,to trimetallic PdM1M2 NWs(PdAuCu,PdCoNi,PdCuZn,PdCuNi,PdAgCu,PdAuCu,PdRuAg,PdAuRu,and PdPtAu),and to tetrametallic PdM1M2M3 NWs(PdAuAgCu,PdCoCuNi,PdAuCuNi,PdPtAuCu,and PdIrPtAu).The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium chloride.As-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies,which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction(EOR).Among them,tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mg-1 Pd and a low activation energy of 13.1 kJ mol^-1,both of which are much better than its counterpart catalysts alloyed with less elements.This work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.
基金the Natural Science Foundation of Jiangsu Province(no.BK20180723)the Open Project of State Key Laboratory of Supramolecular Structure and Materials(no.sklssm2021011)+3 种基金the program of Jiangsu Province Innovation Team for financial supportthe Collaborative Innovation Center of Suzhou Nano Science and Technology for their supportthe Natural Science Foundation of Jiangsu Province(no.BK20191366)for its supportthe National Natural Science Foundation of China(no.21902114)for its support.
文摘Mesoporous single crystals have unique potential in catalysis,but remain unexplored owing to the enormous synthetic challenge that they pose.Herein,we report a facile soft-template method to prepare palladium(Pd)and Pd alloy nanocubes with single-crystallinity and abundant mesoporosity.The successful formation of these exotic nanostructures essentially relies on the cointroduction of cetyltrimethylammonium chloride as the surfactant template and extra Cl^(−) ions as the facet-selective capping agent under well controlled experimental conditions.Thanks to their large surface areas and penetrating mesoporous channels,our products exhibit a great performance for electrochemical CO_(2) reduction.The best sample from alloying palladium with copper enables the efficient formate production with high selectivity(90∼100%)over a broad potential range,and great stability even under the working potential as cathodic as −0.5 V versus a reversible hydrogen electrode.These performance metrics are far superior to previous Pd-based materials,and underscore the structural advantages of our products.
