Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease progression.The proteins,DNA,mRNA,and lipids carried by exosomes reflect...Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease progression.The proteins,DNA,mRNA,and lipids carried by exosomes reflect intracellular changes,and thus can serve as biomarkers for a variety of conditions.In this study,we investigated alterations in the protein content of plasma exosomes derived from patients with Parkinson’s disease and the potential therapeutic roles of these proteins in Parkinson’s disease.Using a tandem mass tag-based quantitative proteomics approach,we characterized the proteomes of plasma exosomes derived from individual patients,identified exosomal protein signatures specific to patients with Parkinson’s disease,and identified N-acetyl-alpha-glucosaminidase as a differentially expressed protein.N-acetyl-alpha-glucosaminidase expression levels in exosomes from the plasma of patients and healthy controls were validated by enzyme-linked immunosorbent assay and western blot.The results demonstrated that the exosomal N-acetyl-alpha-glucosaminidase concentration was not only lower in Parkinson’s disease,but also decreased with increasing Hoehn-Yahr stage,suggesting that N-acetyl-alpha-glucosaminidase could be used to rapidly evaluate Parkinson’s disease severity.Furthermore,western blot and immunohistochemistry analysis showed that N-acetyl-alpha-glucosaminidase levels were markedly reduced both in cells treated with 1-methyl-4-phenylpyridinium and cells overexpressingα-synuclein compared with control cells.Additionally,N-acetyl-alpha-glucosaminidase overexpression significantly increased cell viability and inhibitedα-synuclein expression in 1-methyl-4-phenylpyridinium-treated cells.Taken together,our findings demonstrate for the first time that exosomal N-acetyl-alpha-glucosaminidase may serve as a biomarker for Parkinson’s disease diagnosis,and that N-acetyl-alpha-glucosaminidase may reduceα-synuclein expression and 1-methyl-4-phenylpyridinium-induced neurotoxicity,thus providing a new therapeutic target for Parkinson’s disease.展开更多
The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution ki...The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution kinetics of primary carbides during either heating or soaking.Dissolution of carbides proceeded in three stages(fast→slow→faster)as either temperature or holding time was increased.During the heating process and during the first and third stages of the soaking process,the original size of the carbides determined the steepness of the slope,but during the middle(“slow”)stage of the soaking process,the slope remained zero.The initial size of the carbides varied greatly,but their final dissolution temperature fell within the narrow range of 1210-1235℃,and the holding time remained within 50 min.Fractal analysis was used to study the morphological characteristics of small and medium-sized carbides during the dissolution process.According to changes in the fractal dimension before and after soaking,the carbides tended to evolve towards a more regular morphology.展开更多
Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of ...Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of the 150 phosphate fertilizers stored at the Institute for Crop and Soil Science in Germany has been conducted,supplemented by previously published data.The elements Cd,Bi,U,Cr,Zn,Tl,As,B,Sb,Ni,and Se are found in higher concentrations in sedimentary derived phosphates compared to igneous derived phosphates.Mineral fertilizers contain more than ten times the amount of U,Cd,B,and As compared to farmyard manure.Principal component analyses(PCA)indicate that U,Cd,Be,and Cr are primarily present in sedimentary derived phosphates and their concentrations are 2 to 10 times higher than those in igneous derived phosphates.Regarding heavy metal contamination,over 1000 potential combinations were identified;36% of these were significant but weak(>0.1).It is estimated that approximately 707 t of uranium enter farmland annually through the application of mineral phosphate fertilizers in European countries.This contribution addresses environmental issues related to the utilization of rock phosphate as well as alternative production methods for cleaner and safer phosphate fertilizers while presenting a roadmap with measures for mitigation.展开更多
As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important facto...As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.展开更多
The placement optimization of piezoelectric actuators and active vibration control of a membrane structure are studied in this paper. The classical linear quadratic regulator con- trollers are designed to suppress the...The placement optimization of piezoelectric actuators and active vibration control of a membrane structure are studied in this paper. The classical linear quadratic regulator con- trollers are designed to suppress the unwanted vibration. Simulation results indicate that the optimal locations of piezoelectric actuators are affected deeply by the additional mass and stiff- ness of actuators, the computational efficiency of particle swarm optimizer is higher than that of genetic algorithm for this particular problem, and the control performance of optimally placed actuators is better than that of non-optimally placed actuators.展开更多
A sky model from CLEAN deconvolution is a particularly effective high dynamic range reconstruction in radio astronomy,which can effectively model the sky and remove the sidelobes of the point spread function(PSF)cause...A sky model from CLEAN deconvolution is a particularly effective high dynamic range reconstruction in radio astronomy,which can effectively model the sky and remove the sidelobes of the point spread function(PSF)caused by incomplete sampling in the spatial frequency domain.Compared to scale-free and multi-scale sky models,adaptive-scale sky modeling,which can model both compact and diffuse features,has been proven to have better sky modeling capabilities in narrowband simulated data,especially for large-scale features in high-sensitivity observations which are exactly one of the challenges of data processing for the Square Kilometre Array(SKA).However,adaptive scale CLEAN algorithms have not been verified by real observation data and allow negative components in the model.In this paper,we propose an adaptive scale model algorithm with non-negative constraint and wideband imaging capacities,and it is applied to simulated SKA data and real observation data from the Karl G.Jansky Very Large Array(JVLA),an SKA precursor.Experiments show that the new algorithm can reconstruct more physical models with rich details.This work is a step forward for future SKA image reconstruction and developing SKA imaging pipelines.展开更多
BACKGROUND Endoscopic full-thickness resection(EFTR)is increasingly used for treating gastrointestinal stromal tumors(GISTs)in the stomach.AIM To compare the efficacy,tolerability,and clinical outcomes of EFTR vs surg...BACKGROUND Endoscopic full-thickness resection(EFTR)is increasingly used for treating gastrointestinal stromal tumors(GISTs)in the stomach.AIM To compare the efficacy,tolerability,and clinical outcomes of EFTR vs surgical resection(SR)for gastric GISTs.METHODS We collected clinical data from patients diagnosed with GISTs who underwent either EFTR or SR at our hospital from October 2011 to July 2024.Patients were matched in a 1:1 ratio based on baseline characteristics and tumor clinical-pathological features using propensity score matching.We analyzed perioperative outcomes and follow-up data.The primary outcome measure was progressionfree survival(PFS).RESULTS Out of 912 patients,573 met the inclusion criteria.After matching,each group included 95 patients.The EFTR group demonstrated statistically significant advantages over the SR group in average operative time(P<0.001),length of hospital stay(P<0.001),time to resume liquid diet(P<0.001),incidence of adverse events(P=0.031),and hospitalization costs(P<0.001).The en bloc resection rate was significantly different,with SR group at 100%and EFTR group at 93.7%(P=0.038).The median follow-up was 2451.50 days.Recurrence occurred in 3 patients in the EFTR group and 4 patients in the SR group,with no statistically significant difference(P=1.000).Factors associated with PFS included age,tumor size,high-risk category in the modified National Institutes of Health(NIH)risk score,and resection status.Resection status was identified as an independent prognostic factor for PFS(P=0.0173,hazard ratios=0.0179,95%CI:0.000655-0.491).Notably,there was no statistically significant difference in PFS between the two groups.CONCLUSION This study is a non-inferiority design.The EFTR group significantly outperformed the SR group in terms of operative time,length of hospital stay,time to resume a liquid diet,incidence of adverse events,and hospitalization costs,demonstrating its higher economic efficiency and better tolerability.Additionally,although the en bloc resection rate was lower in the EFTR group compared to the SR group,there were no significant differences in tumor recurrence rates and progression-free survival between the two groups.This study found no statistical difference in the primary endpoint of postoperative recurrence rates between the two groups.However,due to sample size limitations,this result requires further validation in larger-scale studies.The current results should be viewed as exploratory evidence.展开更多
The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibi...The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibit limitations in addressing the distinct statistical characteristics of HSSB,particularly regarding strength design parameters.For instance,GB50010-2010 fails to specify design strength values for reinforcement exceeding 600 MPa,creating technical barriers for advancing HSSB implementation.This study systematically investigates the reliability of eccentric compression concrete columns reinforced with 600 MPa-grade HSSB through high-order moment method analysis.Material partial factors were calibrated against target reliability indices prescribed by GB50068-2018,incorporating critical variables including live-to-dead load ratios,design methodologies,and service conditions.The findings show that the value of k significantly affects the calibration of material partial factors,impacting the reliability of bearing capacity.Considering various k values and target reliability indices,it is recommended that the material partialfactorbe setat1.15,implyingthatthedesignstrengthfor600MPahigh-strengthsteelbars shouldbe considered as 522 MPa.For safety levels I and II,load adjustment factors of 1.1 and 0.9,respectively,may be applied.展开更多
Diabetic peripheral neuropathy(DPN)is a common complication of diabetes and is characterized by sensory and motor impairments resulting from neural injury.Schwann cells(SCs),which are important for peripheral nerve fu...Diabetic peripheral neuropathy(DPN)is a common complication of diabetes and is characterized by sensory and motor impairments resulting from neural injury.Schwann cells(SCs),which are important for peripheral nerve function,are compromised under hyperglycemic conditions,leading to impaired axonal re-generation and demyelination.Autophagy,a cellular degradation process,is essential for SC function and significantly influences DPN progression.This article highlights the significance of autophagy in SCs and its potential as a pharmacotherapeutic target in DPN.We discuss the mechanisms of autophagy in SCs,including the mammalian target of rapamycin,adenosine monophosphate-activated protein kinase,and phosphatase and tensin homolog-induced putative kinase/parkin pathways,and their dysregulation in DPN.This article also exa-mines various natural products and chemical agents that modulate autophagy and enhance the efficacy of DPN treatment.These agents target key signaling pathways,such as adenosine monophosphate-activated protein kinase/mam-malian target of rapamycin and demonstrate potential in promoting nerve re-generation and restoring SC function.The roles of exosomes,long non-coding RNA,and proteins in the regulation of autophagy have also been explored.In conclusion,targeting autophagy in SCs is a promising strategy for DPN treatment and offers new insights into therapeutic interventions.Further research is war-ranted to fully exploit these targets for clinical applications.展开更多
The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective a...The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective activation of peroxomonosulfate(PMS),which possibly determines the degradation pathways of organic contaminants.In this study,by virtue of the precursor alternation,we constructed the state-switched dual metal species with the porous carbon fibers through the electrospinning strategy.Impressively,the optimal catalyst,featuring the electron-deficient cobalt surface oxidative state and most abundant oxygen vacancies(Ov)with MnO_(2)within porous carbon fibers,provides abundant mesoporosity,facilitating the diffusion and accommodation of big carbamazepine molecules during the reaction process.Benefiting from the tandem configuration of carbon fiber-encapsulated nanocrystalline species,a p-n heterojunction configuration evidenced by Mott-Schottky analysis induced local built-in electric field(BIEF)between electron-deficient cobalt and Ov-rich MnO_(2)within carbon matrix-mediated interfacial interactions,which optimizes the adsorption and activation of PMS and intermediates,increases the concentration of reactive radicals around the active site,and significantly enhances the degradation performance.As a result,the optimal catalyst could achieve 100%degradation of 20 ppm carbamazepine(CBZ)within only 4 min with a rate constant of 1.099 min^(-1),showcasing a low activation energy(50 kJ mol^(-1)),obviously outperforming the other counterparts.We further demonstrated the generation pathways of active species by activation of PMS mainly including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radicals(·O_(2)^(-)),and singlet oxygen(^(1)O_(2)),unveiling their contribution to CBZ degradation.The degradation route of CBZ and toxicity analysis of various intermediates were further evaluated.By anchoring the optimal catalyst onto polyester fiber sponge,the photothermal conversion synergistic monolith floatable catalyst and its easy recovery can be achieved,showing good reproducibility and generalizability in the practical application.展开更多
This study systematically investigated the catalytic gasification of two distinct petroleum coke(PC)using magnesium-based tailings(MT)as the catalyst.The research objectives focused on comparative analysis of gasifica...This study systematically investigated the catalytic gasification of two distinct petroleum coke(PC)using magnesium-based tailings(MT)as the catalyst.The research objectives focused on comparative analysis of gasification reactivities and elucidation of carbon microstructure evolution during PC gasification.Experimental results demonstrate that PC-B(derived from Liaohe Oilfields delayed coking)exhibited significantly higher gasification activity than PC-A(from Karamay Oilfields delayed coking),with aromatic C–H content and polycondensation index showing stronger correlations with reactivity than graphitization parameters.Notably,the MT catalyst exhibited material-dependent catalytic behaviors during gasification.MT catalyst enhanced structural ordering in PC-B by:(i)developing denser aromatic carbon layers,(ii)improving microcrystalline alignment,and(iii)elevating graphitization degree.These structural modifications contrasted sharply with PC-A’s response,where MT introduction generated active MgO species in the ash phase,boosting gasification reactivity.Conversely,in PC-B ash systems,MgO preferentially reacted with Al_(2)O_(3) to form inert MgAl_(2)O_(4) spinel,effectively deactivating the catalyst.Kinetic investigations validated the shrinking core model(SCM)as the dominant mechanism,with calculated activation energies of 172.12 kJ/mol(PC-A+5%MT)and 137.19 kJ/mol(PC-B+5%MT).展开更多
An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural ev...An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural evolution of the bonding interface was investigated by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),and transmission electron microscopy(TEM).The results verify that the pinning effect of nano-oxides particles(NPs)in 9Cr ODS alloy significantly enhances its dynamic recrystallization(DRX)temperature and deformation resistance.Continuous DRX(CDRX)first occurred on the 9Cr RAFM alloy side,and the areas near the bonding interface were composed of recrystallized grains.With increasing strain,CDRX also showed up on the 9Cr ODS alloy side.Inevitable slight oxidation occurred at the bonding interface during the hot compression bonding(HCB)process,and the interfacial oxides transformed from initial coarse CrO to TiO and finally to Y-Ti-O nanoparticles with sizes comparable to pre-existing NPs dispersed in the 9Cr ODS alloy matrix.It is believed that interfacial oxide transformation and grain structure consistency contributed to the excellent interface healing of the two dissimilar alloy pieces.The effectiveness of the bonding was tested by tensile tests and fractography analysis,revealing that ideal metallurgical bonding could be achieved under a controlled strain level of 10%at 800℃ followed by soaking at 1000℃ for 4 h.展开更多
The exploration of the molecular characteristics and transformation processes of soil dissolved organic nitrogen(DON)compounds is paramount,as they affect the leaching of DON components into groundwater.Nevertheless,t...The exploration of the molecular characteristics and transformation processes of soil dissolved organic nitrogen(DON)compounds is paramount,as they affect the leaching of DON components into groundwater.Nevertheless,the molecular transformation pathways remain largely uncharted territories.Hence,a comprehensive study of microbial-medicated DON transformation pathways across various land use soilswas conducted.The determination of DON components and microbial communities was accomplished utilizing advanced techniques,namely fourier transform ion cyclotron resonance mass spectrometry and 16S rRNA sequencing.Thesemethodologies were synergistically integrated with the FAPROTAX database and network analysis.The results showed that DON emerged as the predominant nitrogen fraction,displaying significant variations in composition across these soils.The dominant constitutes comprised lignin-like and condensed aromatic compounds,varying in their aromaticity and condensation degrees.Key microbial genera,including Solirubrobacter,67–14,and Bacillus,were identified as crucial for DON decomposition and mineralization.Functional annotation revealed abundant bacteria associated with the breakdown of aromatic compounds,the degradation of aliphatic non-methane hydrocarbons,and the hydrolysis of cellulose.Network analysis emphasized the interconnected and cooperative aspects of DON transformation processes,with notable relationships between N respiration and various degradation activities.Correlation analysis between microbial functions and DON components emphasized distinctmechanisms involved in the transformation of DON components.The orchestrated process of converting high-molecular-weight DON into lowmolecular-weight counterparts facilitates potential leaching into groundwater,emphasizing the need for understanding and managing microbial-mediated DON transformation pathways to mitigate groundwater contamination risk.展开更多
Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rap...Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.展开更多
Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
基金supported by the Science and Technology(S&T)Program of Hebei Province,No.22377798D(to YZ).
文摘Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease progression.The proteins,DNA,mRNA,and lipids carried by exosomes reflect intracellular changes,and thus can serve as biomarkers for a variety of conditions.In this study,we investigated alterations in the protein content of plasma exosomes derived from patients with Parkinson’s disease and the potential therapeutic roles of these proteins in Parkinson’s disease.Using a tandem mass tag-based quantitative proteomics approach,we characterized the proteomes of plasma exosomes derived from individual patients,identified exosomal protein signatures specific to patients with Parkinson’s disease,and identified N-acetyl-alpha-glucosaminidase as a differentially expressed protein.N-acetyl-alpha-glucosaminidase expression levels in exosomes from the plasma of patients and healthy controls were validated by enzyme-linked immunosorbent assay and western blot.The results demonstrated that the exosomal N-acetyl-alpha-glucosaminidase concentration was not only lower in Parkinson’s disease,but also decreased with increasing Hoehn-Yahr stage,suggesting that N-acetyl-alpha-glucosaminidase could be used to rapidly evaluate Parkinson’s disease severity.Furthermore,western blot and immunohistochemistry analysis showed that N-acetyl-alpha-glucosaminidase levels were markedly reduced both in cells treated with 1-methyl-4-phenylpyridinium and cells overexpressingα-synuclein compared with control cells.Additionally,N-acetyl-alpha-glucosaminidase overexpression significantly increased cell viability and inhibitedα-synuclein expression in 1-methyl-4-phenylpyridinium-treated cells.Taken together,our findings demonstrate for the first time that exosomal N-acetyl-alpha-glucosaminidase may serve as a biomarker for Parkinson’s disease diagnosis,and that N-acetyl-alpha-glucosaminidase may reduceα-synuclein expression and 1-methyl-4-phenylpyridinium-induced neurotoxicity,thus providing a new therapeutic target for Parkinson’s disease.
基金supported by Independent Research Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS-2023-Z13)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200)+1 种基金A portion of the work was performed at US National High Magnetic Field Laboratory,which is supported by the National Science Foundation(Cooperative Agreement No.DMR-1157490 and DMR-1644779)the State of Florida.Thanks also to Mary Tyler for editing.
文摘The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution kinetics of primary carbides during either heating or soaking.Dissolution of carbides proceeded in three stages(fast→slow→faster)as either temperature or holding time was increased.During the heating process and during the first and third stages of the soaking process,the original size of the carbides determined the steepness of the slope,but during the middle(“slow”)stage of the soaking process,the slope remained zero.The initial size of the carbides varied greatly,but their final dissolution temperature fell within the narrow range of 1210-1235℃,and the holding time remained within 50 min.Fractal analysis was used to study the morphological characteristics of small and medium-sized carbides during the dissolution process.According to changes in the fractal dimension before and after soaking,the carbides tended to evolve towards a more regular morphology.
基金funded by the Project of Yunnan Province’s Xingdian Talents Support Program(yfgrc202437)the Project of the International Cooperation Science Program of National Natural Science Foundation of China(42361144885).
文摘Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of the 150 phosphate fertilizers stored at the Institute for Crop and Soil Science in Germany has been conducted,supplemented by previously published data.The elements Cd,Bi,U,Cr,Zn,Tl,As,B,Sb,Ni,and Se are found in higher concentrations in sedimentary derived phosphates compared to igneous derived phosphates.Mineral fertilizers contain more than ten times the amount of U,Cd,B,and As compared to farmyard manure.Principal component analyses(PCA)indicate that U,Cd,Be,and Cr are primarily present in sedimentary derived phosphates and their concentrations are 2 to 10 times higher than those in igneous derived phosphates.Regarding heavy metal contamination,over 1000 potential combinations were identified;36% of these were significant but weak(>0.1).It is estimated that approximately 707 t of uranium enter farmland annually through the application of mineral phosphate fertilizers in European countries.This contribution addresses environmental issues related to the utilization of rock phosphate as well as alternative production methods for cleaner and safer phosphate fertilizers while presenting a roadmap with measures for mitigation.
基金supported by the National Natural Science Foundation of China(No.42107052)Beijing Natural Science Foundation(No.JQ21031).
文摘As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.
基金supported by the Natural Science Foundation of China(Grant No.11772187)the Natural Science Foundation of Shanghai(Grant No.16ZR1436200)
文摘The placement optimization of piezoelectric actuators and active vibration control of a membrane structure are studied in this paper. The classical linear quadratic regulator con- trollers are designed to suppress the unwanted vibration. Simulation results indicate that the optimal locations of piezoelectric actuators are affected deeply by the additional mass and stiff- ness of actuators, the computational efficiency of particle swarm optimizer is higher than that of genetic algorithm for this particular problem, and the control performance of optimally placed actuators is better than that of non-optimally placed actuators.
基金partially supported by the National Key R&D Program of China(2018YFA0404602 and 2018YFA0404603)the National SKA Program of China(2020SKA0110300)+3 种基金the National Natural Science Foundation of China(NSFC,11963003,11763002,61572461,11790305,U1831204,U1931141,11961141001 and 11903009)the Guizhou Science&Technology Plan Project(Platform Talent No.[2017]5788,[2017]5781)the Youth Science&Technology Talents Development Project of Guizhou Education Department(No.KY[2018]119 and[2018]433)the Guizhou University Talent Research Fund(No.(2018)60)。
文摘A sky model from CLEAN deconvolution is a particularly effective high dynamic range reconstruction in radio astronomy,which can effectively model the sky and remove the sidelobes of the point spread function(PSF)caused by incomplete sampling in the spatial frequency domain.Compared to scale-free and multi-scale sky models,adaptive-scale sky modeling,which can model both compact and diffuse features,has been proven to have better sky modeling capabilities in narrowband simulated data,especially for large-scale features in high-sensitivity observations which are exactly one of the challenges of data processing for the Square Kilometre Array(SKA).However,adaptive scale CLEAN algorithms have not been verified by real observation data and allow negative components in the model.In this paper,we propose an adaptive scale model algorithm with non-negative constraint and wideband imaging capacities,and it is applied to simulated SKA data and real observation data from the Karl G.Jansky Very Large Array(JVLA),an SKA precursor.Experiments show that the new algorithm can reconstruct more physical models with rich details.This work is a step forward for future SKA image reconstruction and developing SKA imaging pipelines.
文摘BACKGROUND Endoscopic full-thickness resection(EFTR)is increasingly used for treating gastrointestinal stromal tumors(GISTs)in the stomach.AIM To compare the efficacy,tolerability,and clinical outcomes of EFTR vs surgical resection(SR)for gastric GISTs.METHODS We collected clinical data from patients diagnosed with GISTs who underwent either EFTR or SR at our hospital from October 2011 to July 2024.Patients were matched in a 1:1 ratio based on baseline characteristics and tumor clinical-pathological features using propensity score matching.We analyzed perioperative outcomes and follow-up data.The primary outcome measure was progressionfree survival(PFS).RESULTS Out of 912 patients,573 met the inclusion criteria.After matching,each group included 95 patients.The EFTR group demonstrated statistically significant advantages over the SR group in average operative time(P<0.001),length of hospital stay(P<0.001),time to resume liquid diet(P<0.001),incidence of adverse events(P=0.031),and hospitalization costs(P<0.001).The en bloc resection rate was significantly different,with SR group at 100%and EFTR group at 93.7%(P=0.038).The median follow-up was 2451.50 days.Recurrence occurred in 3 patients in the EFTR group and 4 patients in the SR group,with no statistically significant difference(P=1.000).Factors associated with PFS included age,tumor size,high-risk category in the modified National Institutes of Health(NIH)risk score,and resection status.Resection status was identified as an independent prognostic factor for PFS(P=0.0173,hazard ratios=0.0179,95%CI:0.000655-0.491).Notably,there was no statistically significant difference in PFS between the two groups.CONCLUSION This study is a non-inferiority design.The EFTR group significantly outperformed the SR group in terms of operative time,length of hospital stay,time to resume a liquid diet,incidence of adverse events,and hospitalization costs,demonstrating its higher economic efficiency and better tolerability.Additionally,although the en bloc resection rate was lower in the EFTR group compared to the SR group,there were no significant differences in tumor recurrence rates and progression-free survival between the two groups.This study found no statistical difference in the primary endpoint of postoperative recurrence rates between the two groups.However,due to sample size limitations,this result requires further validation in larger-scale studies.The current results should be viewed as exploratory evidence.
基金supported by grants from the Natural Science Foundation of Fujian Province(Grant No.2022J05184).
文摘The utilization of high-strength steel bars(HSSB)within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement.Nevertheless,existing design codes exhibit limitations in addressing the distinct statistical characteristics of HSSB,particularly regarding strength design parameters.For instance,GB50010-2010 fails to specify design strength values for reinforcement exceeding 600 MPa,creating technical barriers for advancing HSSB implementation.This study systematically investigates the reliability of eccentric compression concrete columns reinforced with 600 MPa-grade HSSB through high-order moment method analysis.Material partial factors were calibrated against target reliability indices prescribed by GB50068-2018,incorporating critical variables including live-to-dead load ratios,design methodologies,and service conditions.The findings show that the value of k significantly affects the calibration of material partial factors,impacting the reliability of bearing capacity.Considering various k values and target reliability indices,it is recommended that the material partialfactorbe setat1.15,implyingthatthedesignstrengthfor600MPahigh-strengthsteelbars shouldbe considered as 522 MPa.For safety levels I and II,load adjustment factors of 1.1 and 0.9,respectively,may be applied.
基金Supported by Natural Science Foundation of Hunan Province,No.2023JJ60497Chinese Medicine Research Program of Hunan Province,No.2021169Xiangtan Medical Research Project Plan,No.2022-xtyx-34 and No.2022-xtyx-36.
文摘Diabetic peripheral neuropathy(DPN)is a common complication of diabetes and is characterized by sensory and motor impairments resulting from neural injury.Schwann cells(SCs),which are important for peripheral nerve function,are compromised under hyperglycemic conditions,leading to impaired axonal re-generation and demyelination.Autophagy,a cellular degradation process,is essential for SC function and significantly influences DPN progression.This article highlights the significance of autophagy in SCs and its potential as a pharmacotherapeutic target in DPN.We discuss the mechanisms of autophagy in SCs,including the mammalian target of rapamycin,adenosine monophosphate-activated protein kinase,and phosphatase and tensin homolog-induced putative kinase/parkin pathways,and their dysregulation in DPN.This article also exa-mines various natural products and chemical agents that modulate autophagy and enhance the efficacy of DPN treatment.These agents target key signaling pathways,such as adenosine monophosphate-activated protein kinase/mam-malian target of rapamycin and demonstrate potential in promoting nerve re-generation and restoring SC function.The roles of exosomes,long non-coding RNA,and proteins in the regulation of autophagy have also been explored.In conclusion,targeting autophagy in SCs is a promising strategy for DPN treatment and offers new insights into therapeutic interventions.Further research is war-ranted to fully exploit these targets for clinical applications.
基金financially supported by the National Natural Science Foundation of China(No.21908085)the Natural Science Foundation of Jiangsu province(No.BK20241950)+3 种基金China Postdoctoral Science Foundation(No.2023M731422)the Open Project of State Key Laboratory of Materials Chemical Engineering(No.SKL-MCE-23B)Hubei Key Laboratory of Processing and Application of Catalytic materials(No.202441204)the Science and Technology Plan School-Enterprise Cooperation Industry-University-Research Forward-looking Project of Zhangjiagang(No.ZKYY2341)
文摘The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective activation of peroxomonosulfate(PMS),which possibly determines the degradation pathways of organic contaminants.In this study,by virtue of the precursor alternation,we constructed the state-switched dual metal species with the porous carbon fibers through the electrospinning strategy.Impressively,the optimal catalyst,featuring the electron-deficient cobalt surface oxidative state and most abundant oxygen vacancies(Ov)with MnO_(2)within porous carbon fibers,provides abundant mesoporosity,facilitating the diffusion and accommodation of big carbamazepine molecules during the reaction process.Benefiting from the tandem configuration of carbon fiber-encapsulated nanocrystalline species,a p-n heterojunction configuration evidenced by Mott-Schottky analysis induced local built-in electric field(BIEF)between electron-deficient cobalt and Ov-rich MnO_(2)within carbon matrix-mediated interfacial interactions,which optimizes the adsorption and activation of PMS and intermediates,increases the concentration of reactive radicals around the active site,and significantly enhances the degradation performance.As a result,the optimal catalyst could achieve 100%degradation of 20 ppm carbamazepine(CBZ)within only 4 min with a rate constant of 1.099 min^(-1),showcasing a low activation energy(50 kJ mol^(-1)),obviously outperforming the other counterparts.We further demonstrated the generation pathways of active species by activation of PMS mainly including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radicals(·O_(2)^(-)),and singlet oxygen(^(1)O_(2)),unveiling their contribution to CBZ degradation.The degradation route of CBZ and toxicity analysis of various intermediates were further evaluated.By anchoring the optimal catalyst onto polyester fiber sponge,the photothermal conversion synergistic monolith floatable catalyst and its easy recovery can be achieved,showing good reproducibility and generalizability in the practical application.
基金supported by Natural Science Foundation of Henan Province(Nos.242300421531)Doctor Program of Nanyang Normal University(No.2022ZX006)+1 种基金National Natural Science Cultivation Fund of Nanyang Normal University(No.2023PY013)Fundamental Research Program of Shanxi Province(No.202303021222038).
文摘This study systematically investigated the catalytic gasification of two distinct petroleum coke(PC)using magnesium-based tailings(MT)as the catalyst.The research objectives focused on comparative analysis of gasification reactivities and elucidation of carbon microstructure evolution during PC gasification.Experimental results demonstrate that PC-B(derived from Liaohe Oilfields delayed coking)exhibited significantly higher gasification activity than PC-A(from Karamay Oilfields delayed coking),with aromatic C–H content and polycondensation index showing stronger correlations with reactivity than graphitization parameters.Notably,the MT catalyst exhibited material-dependent catalytic behaviors during gasification.MT catalyst enhanced structural ordering in PC-B by:(i)developing denser aromatic carbon layers,(ii)improving microcrystalline alignment,and(iii)elevating graphitization degree.These structural modifications contrasted sharply with PC-A’s response,where MT introduction generated active MgO species in the ash phase,boosting gasification reactivity.Conversely,in PC-B ash systems,MgO preferentially reacted with Al_(2)O_(3) to form inert MgAl_(2)O_(4) spinel,effectively deactivating the catalyst.Kinetic investigations validated the shrinking core model(SCM)as the dominant mechanism,with calculated activation energies of 172.12 kJ/mol(PC-A+5%MT)and 137.19 kJ/mol(PC-B+5%MT).
基金supported by the National Natural Science Foundation of China(Grant Nos.52233017,51774265,52301032,and 52173305)the National Key Research and Development Program(Grant No.2018YFA0702900)+2 种基金the National Science and Technology Major Project of China(Grant No.2019ZX06004010)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDC04000000)the LingChuang Research Project of China National Nuclear Corporation,CNNC Science Fund for Talented Young Scholars,the Program of CAS Interdisciplinary Innovation Team,and the Youth Innovation Promotion Association,CAS.
文摘An innovative method of hot compression bonding is proposed in this work for the joining of 9Cr oxide dispersion strengthened(ODS)alloy and 9Cr reduced-activation ferritic/martensitic(RAFM)alloy.The microstructural evolution of the bonding interface was investigated by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),and transmission electron microscopy(TEM).The results verify that the pinning effect of nano-oxides particles(NPs)in 9Cr ODS alloy significantly enhances its dynamic recrystallization(DRX)temperature and deformation resistance.Continuous DRX(CDRX)first occurred on the 9Cr RAFM alloy side,and the areas near the bonding interface were composed of recrystallized grains.With increasing strain,CDRX also showed up on the 9Cr ODS alloy side.Inevitable slight oxidation occurred at the bonding interface during the hot compression bonding(HCB)process,and the interfacial oxides transformed from initial coarse CrO to TiO and finally to Y-Ti-O nanoparticles with sizes comparable to pre-existing NPs dispersed in the 9Cr ODS alloy matrix.It is believed that interfacial oxide transformation and grain structure consistency contributed to the excellent interface healing of the two dissimilar alloy pieces.The effectiveness of the bonding was tested by tensile tests and fractography analysis,revealing that ideal metallurgical bonding could be achieved under a controlled strain level of 10%at 800℃ followed by soaking at 1000℃ for 4 h.
基金supported by Beijing Natural Science Foundation(No.JQ21031)the National Natural Science Foundation of China(No.42107052).
文摘The exploration of the molecular characteristics and transformation processes of soil dissolved organic nitrogen(DON)compounds is paramount,as they affect the leaching of DON components into groundwater.Nevertheless,the molecular transformation pathways remain largely uncharted territories.Hence,a comprehensive study of microbial-medicated DON transformation pathways across various land use soilswas conducted.The determination of DON components and microbial communities was accomplished utilizing advanced techniques,namely fourier transform ion cyclotron resonance mass spectrometry and 16S rRNA sequencing.Thesemethodologies were synergistically integrated with the FAPROTAX database and network analysis.The results showed that DON emerged as the predominant nitrogen fraction,displaying significant variations in composition across these soils.The dominant constitutes comprised lignin-like and condensed aromatic compounds,varying in their aromaticity and condensation degrees.Key microbial genera,including Solirubrobacter,67–14,and Bacillus,were identified as crucial for DON decomposition and mineralization.Functional annotation revealed abundant bacteria associated with the breakdown of aromatic compounds,the degradation of aliphatic non-methane hydrocarbons,and the hydrolysis of cellulose.Network analysis emphasized the interconnected and cooperative aspects of DON transformation processes,with notable relationships between N respiration and various degradation activities.Correlation analysis between microbial functions and DON components emphasized distinctmechanisms involved in the transformation of DON components.The orchestrated process of converting high-molecular-weight DON into lowmolecular-weight counterparts facilitates potential leaching into groundwater,emphasizing the need for understanding and managing microbial-mediated DON transformation pathways to mitigate groundwater contamination risk.
基金supported by the Key Research and Development Projects of Anhui Province(No.202304a05020031).
文摘Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
