Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elemen...Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elements Ni,Co,and H increase SFE ofγ-Fe,whereas Mn and Cr decrease SFE.The influence of alloying elements on SFE exhibits short-range characteristics.The effect of synergistic interaction of alloying elements and H on SFE was further investigated.Results show that the co-alloying of Ni/Co with H exacerbates the effect of H on the increase in SFE.In contrast,the synergistic effect of Mn/Cr with H tends to inhibit H from the increasing SFE.Finally,the electronic structure analysis elucidated the microscopic mechanism of the change in SFE.Alloying elements modulate SFE by changing the interatomic charge density at the stacking fault plane and the density of states of the stacking fault structure at the Fermi level.The present results add to the knowledge of alloying related influence on the mechanical property and hydrogen embrittlement ofγ-Fe.展开更多
As the most abundant renewable aromatic biopolymer resource on the Earth,lignin has become a cutting-edge research hotspot in clean photocatalysis,thanks to the distinct highest occupied molecular-orbital and lowest u...As the most abundant renewable aromatic biopolymer resource on the Earth,lignin has become a cutting-edge research hotspot in clean photocatalysis,thanks to the distinct highest occupied molecular-orbital and lowest unoccupied molecular-orbital energy levels driven by the major β-O-4 linked bonds.However,the complex spatial architecture of functional groups,represented by benzene rings in the 3D intertwined macromolecular chains of lignin,and the challenge of enhancing carrier separation efficiency remain persistent obstacles hindering the development of lignin-based photocatalysts.Herein,a strategy of constructing lignin nanosphere-graphene oxide heterointerfaces(EL-GO)is proposed to comprehensively enhance the efficacy of functional groups and facilitate photoelectron migration modes.The recombination time of lightexcited photoelectrons is effectively prolonged by the π-π interactions between the“Donor site”and“Acceptor site”functional regions,along with the directional migration of photoelectrons between EL and GO.The photocatalytic efficiency of H_(2)O_(2) production using EL-GO is significantly enhanced under the protective mechanism of GO.To assess its potential,a prospect estimation of EL-GO in a lake containing various pollutants and metal ions was conducted,simulating real water conditions.This pioneering engineering effort aims to curb excessive consumption of fossil fuels and explore the green applications of lignin,thereby constructing a“carbon-neutral”feedstock system.展开更多
Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the cr...Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.展开更多
Selective laser melting(SLM)is an advanced additive manufacturing technique that enables the fabrication of complex metal components with high density,precision,and design flexibility.A novel Sc-free Al-4.58Mg-1.17Mn-...Selective laser melting(SLM)is an advanced additive manufacturing technique that enables the fabrication of complex metal components with high density,precision,and design flexibility.A novel Sc-free Al-4.58Mg-1.17Mn-1.59Zr-1.45Ti alloy was successfully fabricated via SLM,achieving a relative density of~99.89%.The microstructure of the as-fabricated alloy was characterized by scanning electron microscopy and transmission electron microscopy,which revealed refined equiaxed grains,a high density of low-angle grain boundaries and dislocation structures,as well as Mg segregation along grain boundaries.Additionally,a variety of dispersed precipitates were identified,including Mg-containing oxides,L1_(2)-Al_(3)(Ti_(x),Zr_(1−x)),and Al_(3)Zr particles.Room-temperature tensile tests showed that the alloy exhibits an excellent combination of strength and ductility,with a yield strength of 453.2±12 MPa,an ultimate tensile strength of 515.1±8 MPa,and an elongation of 22.5%±0.3%.The high strength was attributed to the combined effects of grain boundary strengthening,solid solution strengthening,precipitation strengthening,and dislocation strengthening.The developed Sc-free Al-Mg-Mn-Zr-Ti alloy demonstrates significant potential as an economical high-strength lightweight material for SLM-based manufacturing applications.展开更多
Direct brazing was employed to fabricate a“Cu circuit layer-Si_(3)N_(4) ceramic-Cu heat sink”structure for power electronic devices,enabling a shortened heat dissipation path and enhanced thermal management.Structur...Direct brazing was employed to fabricate a“Cu circuit layer-Si_(3)N_(4) ceramic-Cu heat sink”structure for power electronic devices,enabling a shortened heat dissipation path and enhanced thermal management.Structural components(60 mm×60 mm and 30 mm×30 mm)were brazed at 780°C for 20 min to simulate finless and finned heat sinks.The effects of composite brazing filler metal and copper underlayer stiffness on warpage and thermal resistance were systematically evaluated.The results show that composite fillers effectively suppressed warpage,reducing deformation in a 60×60 mm²-finned component from 0.95%to 0.73%,with a measured thermal resistance of 0.1936 K/W.After surface soldering of the insulated gate bipolar transistor(IGBT),the total thermal resistance from junction to ambient decreased by 10.2%compared with conventional structures.This study demonstrates a practical route to improve heat dissipation and optimize the thermal design of highpower modules,providing an industry-ready thermal management solution for high-power-density SiC/GaN devices.展开更多
AIM:To explore the dynamic changes of prion protein (PrPc) in the process of gastric cancer drug resistance and the role of PrPc expression in the prognosis of gastric cancer patients receiving chemotherapy.METHODS:A ...AIM:To explore the dynamic changes of prion protein (PrPc) in the process of gastric cancer drug resistance and the role of PrPc expression in the prognosis of gastric cancer patients receiving chemotherapy.METHODS:A series of gastric cancer cell lines resistant to different concentrations of adriamycin was established,and the expression of PrPc,Bcl-2 and Bax was detected in these cells.Apoptosis was determined using Annexin V staining.Western blotting and immunohisto-chemistry were performed to detect the expression of PrPc in patients receiving chemotherapy and to explore the role of PrPc expression in predicting the chemosensitivity and the outcome of gastric cancer patients receiving chemotherapy.Follow-up was performed for 2 years.RESULTS:PrPc expression was increased with the increase in drug resistance.Bcl-2,together with PrPc,increased the level of anti-apoptosis of cancer cells.Increased PrPc expression predicted the enhanced level of anti-apoptosis and resistance to anticancer drugs.PrPc expression could be used as a marker for predicting the efficacy of chemotherapy and the prognosis of gastric cancer.Increased PrPc expression predicted both poor chemosensitivity and a low 2-year survival rate.Contrarily,low PrPc expression predicted favorable chemosensitivity and a relatively high 2-year survival rate.CONCLUSION:PrPc expression is associated with histological types and differentiation of gastric cancer cells;The PrPc expression level might be a valuable marker in predicting the efficacy of chemotherapy and the prognosis of gastric cancer patients receiving chemotherapy.展开更多
BACKGROUND Higher intraocular pressure(IOP)is a major risk factor for developing glaucoma,and the leading cause of irreversible blindness worldwide.High altitude(HA)may be involved in IOP,but the reported results were...BACKGROUND Higher intraocular pressure(IOP)is a major risk factor for developing glaucoma,and the leading cause of irreversible blindness worldwide.High altitude(HA)may be involved in IOP,but the reported results were conflicting.Ascent to HA directly by plane from low altitude regions is an acute,effortless exposure.However,the effects of such exposure to different altitudes on IOP have rarely been reported.AIM To investigate changes in IOP after rapid effortless exposure to HA in stages and compare it with systemic parameters.METHODS Fifty-eight healthy subjects(116 eyes)were divided into three groups:17 lowaltitude(LA)residents[44 m above sea level(ASL)],22 HA residents(2261 m ASL)and 19 very HA(VHA)residents(3750 m ASL).The LA group flew to HA first.Three days later,they flew with the HA group to VHA where both groups stayed for 2 d.Then,the LA group flew back to HA and stayed for 1 d before flying back to 44 m.IOP,oxygen saturation(SpO2)and pulse rate were measured.The linear mixed model was used to compare repeated measurements.RESULTS IOP in the LA group significantly decreased from 18.41±2.40 mmHg at 44 m to 13.60±3.68 mmHg at 2261 m ASL(P<0.001),and then to 11.85±2.48 mmHg at 3750 m ASL(P=0.036 compared to IOP at 2261 m ASL)and partially recovered to 13.47±2.57 mmHg upon return to 44 m.IOP in the LA group at HA and VHA was comparable to that in the local residents(12.2±2.4 mmHg for HA,11.5±1.8 mmHg for VHA).IOP was positively associated with SpO2 while negatively associated with pulse rate.CONCLUSION IOP in the LA group gradually reduced as altitude elevated in stages and became comparable to IOP in local residents.Hypoxia may be associated with IOP,which deserves further study.展开更多
The natural hematite(α-Fe_(2)O_(3)) is stable and abundant on the earth,as well as with strange electronic band structure and good visible light absorption properties.However,the composition and catalytic performance...The natural hematite(α-Fe_(2)O_(3)) is stable and abundant on the earth,as well as with strange electronic band structure and good visible light absorption properties.However,the composition and catalytic performance of natural hematite should be explored.In this study,the photo-assisted hematite nanoparticles activated persulfate(H-NPs/PS/vis)system was constructed.As detected,H-NPs had an irregular agglomerate structure with abundant internal pore and were mainly composed of Fe_(2)O_(3),SiO_(2) and TiO_(2).The system was applied to removing various antibiotic(i.e.,lomefloxacin,ciprofloxacin and enrofloxacin with initial concentration of 10 mg/L),achieving high degradation performance of 82.0%,81.2%and 82.2%after120,330 and 240 min,respectively.Moreover,H-NPs had excellent reusability with low metal leaching(Ti leaching percentage lower than 0.01%,Fe dissolution percentage was 0.48%)and stable structure.At last,a possible reaction mechanism of H-NPs/PS/vis system was proposed that lomefloxacin(LOM)was efficiently removed via the synergistic process of components contained in H-NPs with PS and light,involving the generation of·O_(2)^(-),·OH and SO_(4)^(·-).Above all,this paper provided a novel application scheme of natural hematite through in-depth and comprehensive experimental exploration.展开更多
The stability and chaotic vibrations of a pipe conveying fluid with both ends fixed, excited by the harmonic motion of its supporting base in a direction normal to the pipe span, were investigated with the aid of mode...The stability and chaotic vibrations of a pipe conveying fluid with both ends fixed, excited by the harmonic motion of its supporting base in a direction normal to the pipe span, were investigated with the aid of modern numerical techniques,involving the phase portrait,Lyapunov exponent and Poincare map tc. The nonlinear differential equations of motion of the system were derived by considering the additional axial force due to the lateral motion of the pipe. Attention was concentrated on the effect of forcing frequency and flow velocity on the dynamics of the system. It is shown that chaotic motions can occur in this system in a certain region of parameter space,and it is also found that three types of routes to chaos exist in the system:(i)period doubling bifurcations;(ii)quasi periodic motions;and (iii)intermittent chaos.展开更多
BACKGROUND Glomerular endothelial cell(GENC)injury is a characteristic of early-stage diabetic nephropathy(DN),and the investigation of potential therapeutic targets for preventing GENC injury is of clinical importanc...BACKGROUND Glomerular endothelial cell(GENC)injury is a characteristic of early-stage diabetic nephropathy(DN),and the investigation of potential therapeutic targets for preventing GENC injury is of clinical importance.AIM To investigate the role ofβ-arrestin-2 in GENCs under DN conditions.METHODS Eight-week-old C57BL/6J mice were intraperitoneally injected with streptozotocin to induce DN.GENCs were transfected with plasmids containing siRNA-β-arrestin-2,shRNA-activating transcription factor 6(ATF6),pCDNA-β-arrestin-2,or pCDNA-ATF6.Additionally,adeno-associated virus(AAV)containing shRNA-β-arrestin-2 was administered via a tail vein injection in DN mice.RESULTS The upregulation ofβ-arrestin-2 was observed in patients with DN as well as in GENCs from DN mice.Knockdown ofβ-arrestin-2 reduced apoptosis in high glucose-treated GENCs,which was reversed by the overexpression of ATF6.Moreover,overexpression ofβ-arrestin-2 Led to the activation of endoplasmic reticulum(ER)stress and the apoptosis of GENCs which could be mitigated by silencing of ATF6.Furthermore,knockdown ofβ-arrestin-2 by the administration of AAV-shRNA-β-arrestin-2 alleviated renal injury in DN mice.CONCLUSION Knockdown ofβ-arrestin-2 prevents GENC apoptosis by inhibiting ATF6-mediated ER stress in vivo and in vitro.Consequently,β-arrestin-2 may represent a promising therapeutic target for the clinical management of patients with DN.展开更多
This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins（SCER）. The effects of the mass ratio of methanol to acidified ...This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins（SCER）. The effects of the mass ratio of methanol to acidified oil,reaction temperature,and catalyst loading were studied to optimize the conditions for maximum conversion of free fatty acids（FFAs）. The results showed that the optimal conversion rate of FFAs was 91.87% at the mass ratio of methanol to acidified oil of 2.5：1.0,reaction temperature of 65.0 °C,catalyst loading of 5.0 g and reaction time of 8.0 h. The external and internal mass transfer resistances were negligible based on the experimental results and a pseudo-homogeneous kinetic model was proposed for the esterification. The activation energy and thermodynamic parameters including G,S and H were determined. The conversion rates of FFAs obtained from the established model were in good agreement with the experimental data.展开更多
Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combin...Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combinations of loss models, varies significantly depending on the compressor's geometry and operational range. This variance necessitates substantial experimental or Computational Fluid Dynamics(CFD) data for coefficient calibration. To address this challenge, this study presents an axisymmetric characteristic model for compressor performance assessment. This model incorporates the factors of blade angle, meridional passage area, and the radial deflection angle of meridional streamlines of the compressor. These factors are derived from fundamental aerodynamic equations encompassing mass, momentum, and energy conservation of the compressor. In contrast to conventional one-dimensional approaches, the proposed method reduces the number of loss coefficients and more effectively accounts for the impact of geometric alterations on centrifugal compressor properties. Furthermore, the model reduces dependence on experimental and CFD data. Efficacy of the model is validated using experimental data from four distinct types of centrifugal compressors. Correlation analysis reveals that the model's coefficients can be expressed as functions of the ratio of the Reynolds number to the impeller tip speed. This ratio serves as a characteristic parameter for the design and optimization of centrifugal compressors. Consequently, the proposed method offers an efficient and accurate means for the quick computation of centrifugal compressor characteristics. This is of great significance for improving the efficiency of centrifugal compressors and reducing energy consumption.展开更多
1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength d...1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength due to the nanoprecipitates often corresponds to a decrease in ductility [4,5], and this conflicting relationship between strength and ductility has attracted the attention of researchers,who have sought to find a balance between strength and ductility [6–8].展开更多
Working memory（WM）allows humans to hold necessary information in temporary storage and manipulate such information online for higher-order cognitive functions,such as language understanding,decision making,and probl...Working memory（WM）allows humans to hold necessary information in temporary storage and manipulate such information online for higher-order cognitive functions,such as language understanding,decision making,and problem solving.Since its first appearance in the science of psychology in the 1960s,many theories have sought to elucidate the nature of WM.The most accepted model is展开更多
Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is k...Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is known about the long-term stability of these biomarker proteins in plasma samples stored at-80°C.We aimed to explore how storage time would affect the diagnostic accuracy of these biomarkers using a large cohort.Plasma samples from 229 cognitively unimpaired individuals,encompassing healthy controls and those experiencing subjective cognitive decline,as well as 99 patients with cognitive impairment,comprising those with mild cognitive impairment and dementia,were acquired from the Sino Longitudinal Study on Cognitive Decline project.These samples were stored at-80°C for up to 6 years before being used in this study.Our results showed that plasma levels of Aβ42,Aβ40,neurofilament light chain,and glial fibrillary acidic protein were not significantly correlated with sample storage time.However,the level of total tau showed a negative correlation with sample storage time.Notably,in individuals without cognitive impairment,plasma levels of total protein and tau phosphorylated protein threonine 181(p-tau181)also showed a negative correlation with sample storage time.This was not observed in individuals with cognitive impairment.Consequently,we speculate that the diagnostic accuracy of plasma p-tau181 and the p-tau181 to total tau ratio may be influenced by sample storage time.Therefore,caution is advised when using these plasma biomarkers for the identification of neurodegenerative diseases,such as Alzheimer's disease.Furthermore,in cohort studies,it is important to consider the impact of storage time on the overall results.展开更多
Abstract The dopamine transporter （DAT） is involved in the regulation of extracellular dopamine levels. A 40-bp variable-number tandem repeat （VNTR） polymorphism in the 3-untranslated region （3UTR） of the DAT ha...Abstract The dopamine transporter （DAT） is involved in the regulation of extracellular dopamine levels. A 40-bp variable-number tandem repeat （VNTR） polymorphism in the 3-untranslated region （3UTR） of the DAT has been reported to be associated with various phenotypes that are involved in the aberrant regulation of dopaminergic neu- rotransmission. In the present study, we found that miR- 137 and miR-491 caused a marked reduction of DAT expression, thereby influencing neuronal dopamine trans- port. Moreover, the regulation of miR-137 and miR-491 on this transport disappeared after the DAT was silenced. The miR-491 seed region that is located on the VNTR sequence in the 3＇UTR of the DAT and the regulatory effect of miR- 491 on the DAT depended on the VNTR copy-number. These data indicate that miR-137 and miR-491 regulate DAT expression and dopamine transport at the post- transcriptional level, suggesting that microRNA may be targeted for the treatment of diseases associated with DAT dysfunction.展开更多
Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity ...Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity of pathology,potentially hindering clinical trials in the development of medical treatment.Brain-based subtyping studies utilize magnetic resonance imaging(MRI)and data-driven methods to discover the subtypes of diseases,providing a new perspective on disease heterogeneity.展开更多
Supramolecular luminescent materials(SLMs)exhibit exceptional luminescence properties and the ability to be intelligently regulated through diverse assembly approaches,making them highly attractive in the field of lum...Supramolecular luminescent materials(SLMs)exhibit exceptional luminescence properties and the ability to be intelligently regulated through diverse assembly approaches,making them highly attractive in the field of luminescent materials.In recent years,the novel macrocyclic arenes characterized by unique electron-rich structures,ease of derivatization,tunable conformations and even inherent luminescence properties afford much opportunities to create such dynamic smart luminescent materials.The incorporation of macrocyclic arenes into SLMs leads to simple preparation process,diverse photophysical phenomena and sophisticated regulatory mechanisms,which is also currently one of the most frontier and hot topics in macrocyclic and supramolecular chemistry and even luminescent materials.In this review,the research advances in construction and applications of SLMs based on macrocyclic arenes in the last several years will be presented from the different assembly strategies,including host-vip complexes,supramolecular polymers,nanoparticles,and other assemblies.Moreover,some insights into future directions for this research area will also be offered.展开更多
BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal ...BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal hypertension(PH).AIM To investigate the anatomical characteristics of balloon-occluded hepatic venous angiography in patients with PH and analyze the relationship between the WHVP and portal venous pressure(PVP).METHODS This retrospective study included 877 patients with PH who met the inclusion criteria from January 2020 to June 2024.Routine and innovative hepatic venous angiography was performed during transjugular intrahepatic portosystemic shunt procedures to measure hepatic venous and PVPs.All patients'angiographic images were collected for analysis.The associations between WHVP and PVP in each group were analyzed via linear regression analysis,and a predictive model was established.RESULTS The 877 patients had a mean age of 52.6±13.0 years,with 582 males and 295 females.Patients were categorized into four groups on the basis of their anatomical structure.All groups showed strong correlations between WHVP and PVP.The regression coefficient between the WHVP and PVP in the hepatic right vein-portal venous angiography group was 0.884(P<0.05);in the hepatic right vein-accessory hepatic venous angiography group,it was 0.721(P<0.05);in the hepatic right vein-middle hepatic venous angiography group,it was 0.344(P<0.05);and in the hepatic right vein-nonangiography group,it was 0.293(P<0.05).CONCLUSION The presence and anatomical classification of hepatic venous collaterals are key factors influencing the relationship between WHVP with and PVP.Based on the different anatomical classifications of hepatic veins,WHVP can be used to estimate PVP,improving the accuracy of PVP prediction.展开更多
基金supported by National Science and Technology Major Project(2025ZD0618901)National Natural Science Foundation of China(U2241245 and 52321001)+2 种基金Aeronautical Science Foundation of China(2022Z053092001)Natural Science Foundation of Shenyang(23-503-6-05)Science and Technology Major Project of Liaoning Province(2024JH1/11700028).
文摘Effects of alloying elements Ni,Co,Mn,Cr,and H on the stacking fault energy(SFE)ofγ-Fe and its microscopic mechanisms were systematically investigated.Generalized SFE calculations show that individual alloying elements Ni,Co,and H increase SFE ofγ-Fe,whereas Mn and Cr decrease SFE.The influence of alloying elements on SFE exhibits short-range characteristics.The effect of synergistic interaction of alloying elements and H on SFE was further investigated.Results show that the co-alloying of Ni/Co with H exacerbates the effect of H on the increase in SFE.In contrast,the synergistic effect of Mn/Cr with H tends to inhibit H from the increasing SFE.Finally,the electronic structure analysis elucidated the microscopic mechanism of the change in SFE.Alloying elements modulate SFE by changing the interatomic charge density at the stacking fault plane and the density of states of the stacking fault structure at the Fermi level.The present results add to the knowledge of alloying related influence on the mechanical property and hydrogen embrittlement ofγ-Fe.
基金National Natural Science Foundation of China,Grant/Award Numbers:22178037,22278046,U22A20424Liaoning Education Department Project,Grant/Award Number:JYTMS20230396。
文摘As the most abundant renewable aromatic biopolymer resource on the Earth,lignin has become a cutting-edge research hotspot in clean photocatalysis,thanks to the distinct highest occupied molecular-orbital and lowest unoccupied molecular-orbital energy levels driven by the major β-O-4 linked bonds.However,the complex spatial architecture of functional groups,represented by benzene rings in the 3D intertwined macromolecular chains of lignin,and the challenge of enhancing carrier separation efficiency remain persistent obstacles hindering the development of lignin-based photocatalysts.Herein,a strategy of constructing lignin nanosphere-graphene oxide heterointerfaces(EL-GO)is proposed to comprehensively enhance the efficacy of functional groups and facilitate photoelectron migration modes.The recombination time of lightexcited photoelectrons is effectively prolonged by the π-π interactions between the“Donor site”and“Acceptor site”functional regions,along with the directional migration of photoelectrons between EL and GO.The photocatalytic efficiency of H_(2)O_(2) production using EL-GO is significantly enhanced under the protective mechanism of GO.To assess its potential,a prospect estimation of EL-GO in a lake containing various pollutants and metal ions was conducted,simulating real water conditions.This pioneering engineering effort aims to curb excessive consumption of fossil fuels and explore the green applications of lignin,thereby constructing a“carbon-neutral”feedstock system.
基金supported by the Jilin Scientific and Technological Development Program(No.YDZJ202201ZYTS669)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043 and 51604034).
文摘Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.
基金supported by the Jilin Scientific and Technological Development Program(No.20240302108GX)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043,and 51604034).
文摘Selective laser melting(SLM)is an advanced additive manufacturing technique that enables the fabrication of complex metal components with high density,precision,and design flexibility.A novel Sc-free Al-4.58Mg-1.17Mn-1.59Zr-1.45Ti alloy was successfully fabricated via SLM,achieving a relative density of~99.89%.The microstructure of the as-fabricated alloy was characterized by scanning electron microscopy and transmission electron microscopy,which revealed refined equiaxed grains,a high density of low-angle grain boundaries and dislocation structures,as well as Mg segregation along grain boundaries.Additionally,a variety of dispersed precipitates were identified,including Mg-containing oxides,L1_(2)-Al_(3)(Ti_(x),Zr_(1−x)),and Al_(3)Zr particles.Room-temperature tensile tests showed that the alloy exhibits an excellent combination of strength and ductility,with a yield strength of 453.2±12 MPa,an ultimate tensile strength of 515.1±8 MPa,and an elongation of 22.5%±0.3%.The high strength was attributed to the combined effects of grain boundary strengthening,solid solution strengthening,precipitation strengthening,and dislocation strengthening.The developed Sc-free Al-Mg-Mn-Zr-Ti alloy demonstrates significant potential as an economical high-strength lightweight material for SLM-based manufacturing applications.
基金supported by National Science and Technology Major Project of China(Grant numbers 2024ZD06049××)State Key Laboratory of Precious Metal Functional Materials(Grant No.YPML-20240502045).
文摘Direct brazing was employed to fabricate a“Cu circuit layer-Si_(3)N_(4) ceramic-Cu heat sink”structure for power electronic devices,enabling a shortened heat dissipation path and enhanced thermal management.Structural components(60 mm×60 mm and 30 mm×30 mm)were brazed at 780°C for 20 min to simulate finless and finned heat sinks.The effects of composite brazing filler metal and copper underlayer stiffness on warpage and thermal resistance were systematically evaluated.The results show that composite fillers effectively suppressed warpage,reducing deformation in a 60×60 mm²-finned component from 0.95%to 0.73%,with a measured thermal resistance of 0.1936 K/W.After surface soldering of the insulated gate bipolar transistor(IGBT),the total thermal resistance from junction to ambient decreased by 10.2%compared with conventional structures.This study demonstrates a practical route to improve heat dissipation and optimize the thermal design of highpower modules,providing an industry-ready thermal management solution for high-power-density SiC/GaN devices.
基金Supported by National Natural Science Foundation of China, No. 30672063China Postdoctoral Science Foundation Funded Project,No. 20080431404China Postdoctoral Special Fund,No. 200801038
文摘AIM:To explore the dynamic changes of prion protein (PrPc) in the process of gastric cancer drug resistance and the role of PrPc expression in the prognosis of gastric cancer patients receiving chemotherapy.METHODS:A series of gastric cancer cell lines resistant to different concentrations of adriamycin was established,and the expression of PrPc,Bcl-2 and Bax was detected in these cells.Apoptosis was determined using Annexin V staining.Western blotting and immunohisto-chemistry were performed to detect the expression of PrPc in patients receiving chemotherapy and to explore the role of PrPc expression in predicting the chemosensitivity and the outcome of gastric cancer patients receiving chemotherapy.Follow-up was performed for 2 years.RESULTS:PrPc expression was increased with the increase in drug resistance.Bcl-2,together with PrPc,increased the level of anti-apoptosis of cancer cells.Increased PrPc expression predicted the enhanced level of anti-apoptosis and resistance to anticancer drugs.PrPc expression could be used as a marker for predicting the efficacy of chemotherapy and the prognosis of gastric cancer.Increased PrPc expression predicted both poor chemosensitivity and a low 2-year survival rate.Contrarily,low PrPc expression predicted favorable chemosensitivity and a relatively high 2-year survival rate.CONCLUSION:PrPc expression is associated with histological types and differentiation of gastric cancer cells;The PrPc expression level might be a valuable marker in predicting the efficacy of chemotherapy and the prognosis of gastric cancer patients receiving chemotherapy.
基金Supported by the National Natural Science Foundation of China,No.81730027Beijing Natural Science Foundation,No.7162037The Capital Health Research and Development of Special Foundation,No.ZYLX201501
文摘BACKGROUND Higher intraocular pressure(IOP)is a major risk factor for developing glaucoma,and the leading cause of irreversible blindness worldwide.High altitude(HA)may be involved in IOP,but the reported results were conflicting.Ascent to HA directly by plane from low altitude regions is an acute,effortless exposure.However,the effects of such exposure to different altitudes on IOP have rarely been reported.AIM To investigate changes in IOP after rapid effortless exposure to HA in stages and compare it with systemic parameters.METHODS Fifty-eight healthy subjects(116 eyes)were divided into three groups:17 lowaltitude(LA)residents[44 m above sea level(ASL)],22 HA residents(2261 m ASL)and 19 very HA(VHA)residents(3750 m ASL).The LA group flew to HA first.Three days later,they flew with the HA group to VHA where both groups stayed for 2 d.Then,the LA group flew back to HA and stayed for 1 d before flying back to 44 m.IOP,oxygen saturation(SpO2)and pulse rate were measured.The linear mixed model was used to compare repeated measurements.RESULTS IOP in the LA group significantly decreased from 18.41±2.40 mmHg at 44 m to 13.60±3.68 mmHg at 2261 m ASL(P<0.001),and then to 11.85±2.48 mmHg at 3750 m ASL(P=0.036 compared to IOP at 2261 m ASL)and partially recovered to 13.47±2.57 mmHg upon return to 44 m.IOP in the LA group at HA and VHA was comparable to that in the local residents(12.2±2.4 mmHg for HA,11.5±1.8 mmHg for VHA).IOP was positively associated with SpO2 while negatively associated with pulse rate.CONCLUSION IOP in the LA group gradually reduced as altitude elevated in stages and became comparable to IOP in local residents.Hypoxia may be associated with IOP,which deserves further study.
基金kindly funded by National Natural Science Foundation of China(No.51978319)Outstanding Youth Foundation of Gansu Province(No.20JR10RA651)Natural Science Foundation of Gansu Province(No.20JR10RA635)。
文摘The natural hematite(α-Fe_(2)O_(3)) is stable and abundant on the earth,as well as with strange electronic band structure and good visible light absorption properties.However,the composition and catalytic performance of natural hematite should be explored.In this study,the photo-assisted hematite nanoparticles activated persulfate(H-NPs/PS/vis)system was constructed.As detected,H-NPs had an irregular agglomerate structure with abundant internal pore and were mainly composed of Fe_(2)O_(3),SiO_(2) and TiO_(2).The system was applied to removing various antibiotic(i.e.,lomefloxacin,ciprofloxacin and enrofloxacin with initial concentration of 10 mg/L),achieving high degradation performance of 82.0%,81.2%and 82.2%after120,330 and 240 min,respectively.Moreover,H-NPs had excellent reusability with low metal leaching(Ti leaching percentage lower than 0.01%,Fe dissolution percentage was 0.48%)and stable structure.At last,a possible reaction mechanism of H-NPs/PS/vis system was proposed that lomefloxacin(LOM)was efficiently removed via the synergistic process of components contained in H-NPs with PS and light,involving the generation of·O_(2)^(-),·OH and SO_(4)^(·-).Above all,this paper provided a novel application scheme of natural hematite through in-depth and comprehensive experimental exploration.
基金Supported by the Science Foundation of Liaoning Province Government!( 96 2 1 2 9)
文摘The stability and chaotic vibrations of a pipe conveying fluid with both ends fixed, excited by the harmonic motion of its supporting base in a direction normal to the pipe span, were investigated with the aid of modern numerical techniques,involving the phase portrait,Lyapunov exponent and Poincare map tc. The nonlinear differential equations of motion of the system were derived by considering the additional axial force due to the lateral motion of the pipe. Attention was concentrated on the effect of forcing frequency and flow velocity on the dynamics of the system. It is shown that chaotic motions can occur in this system in a certain region of parameter space,and it is also found that three types of routes to chaos exist in the system:(i)period doubling bifurcations;(ii)quasi periodic motions;and (iii)intermittent chaos.
基金Supported by Key Research and Development Program of Shandong Province,No.2021CXGC011101Special Fund for Taishan Scholars Project,No.tsqn202211324+2 种基金National Natural Science Foundation of China,No.81900669Natural Science Foundation of Shandong Province,China,No.ZR2018PH007the Multidisciplinary Innovation Center for Nephrology of the Second Hospital of Shandong University.
文摘BACKGROUND Glomerular endothelial cell(GENC)injury is a characteristic of early-stage diabetic nephropathy(DN),and the investigation of potential therapeutic targets for preventing GENC injury is of clinical importance.AIM To investigate the role ofβ-arrestin-2 in GENCs under DN conditions.METHODS Eight-week-old C57BL/6J mice were intraperitoneally injected with streptozotocin to induce DN.GENCs were transfected with plasmids containing siRNA-β-arrestin-2,shRNA-activating transcription factor 6(ATF6),pCDNA-β-arrestin-2,or pCDNA-ATF6.Additionally,adeno-associated virus(AAV)containing shRNA-β-arrestin-2 was administered via a tail vein injection in DN mice.RESULTS The upregulation ofβ-arrestin-2 was observed in patients with DN as well as in GENCs from DN mice.Knockdown ofβ-arrestin-2 reduced apoptosis in high glucose-treated GENCs,which was reversed by the overexpression of ATF6.Moreover,overexpression ofβ-arrestin-2 Led to the activation of endoplasmic reticulum(ER)stress and the apoptosis of GENCs which could be mitigated by silencing of ATF6.Furthermore,knockdown ofβ-arrestin-2 by the administration of AAV-shRNA-β-arrestin-2 alleviated renal injury in DN mice.CONCLUSION Knockdown ofβ-arrestin-2 prevents GENC apoptosis by inhibiting ATF6-mediated ER stress in vivo and in vitro.Consequently,β-arrestin-2 may represent a promising therapeutic target for the clinical management of patients with DN.
基金support from the Natural Science Foundation of Shandong Province (Grant no.ZR2013BL010)the Research Excellence Award of Shandong University of Technology and the Zibo Technology Research and Development Program of China (Grant no.2013GG04110)
文摘This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins（SCER）. The effects of the mass ratio of methanol to acidified oil,reaction temperature,and catalyst loading were studied to optimize the conditions for maximum conversion of free fatty acids（FFAs）. The results showed that the optimal conversion rate of FFAs was 91.87% at the mass ratio of methanol to acidified oil of 2.5：1.0,reaction temperature of 65.0 °C,catalyst loading of 5.0 g and reaction time of 8.0 h. The external and internal mass transfer resistances were negligible based on the experimental results and a pseudo-homogeneous kinetic model was proposed for the esterification. The activation energy and thermodynamic parameters including G,S and H were determined. The conversion rates of FFAs obtained from the established model were in good agreement with the experimental data.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,China(No. 2022A1515110007)the Natural Science Foundation of Guangdong Province, China (No. 2023A1515012869)the GDAS’ Project of Science and Technology Development, China (No. 2021GDASYL-20210103090)。
文摘Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combinations of loss models, varies significantly depending on the compressor's geometry and operational range. This variance necessitates substantial experimental or Computational Fluid Dynamics(CFD) data for coefficient calibration. To address this challenge, this study presents an axisymmetric characteristic model for compressor performance assessment. This model incorporates the factors of blade angle, meridional passage area, and the radial deflection angle of meridional streamlines of the compressor. These factors are derived from fundamental aerodynamic equations encompassing mass, momentum, and energy conservation of the compressor. In contrast to conventional one-dimensional approaches, the proposed method reduces the number of loss coefficients and more effectively accounts for the impact of geometric alterations on centrifugal compressor properties. Furthermore, the model reduces dependence on experimental and CFD data. Efficacy of the model is validated using experimental data from four distinct types of centrifugal compressors. Correlation analysis reveals that the model's coefficients can be expressed as functions of the ratio of the Reynolds number to the impeller tip speed. This ratio serves as a characteristic parameter for the design and optimization of centrifugal compressors. Consequently, the proposed method offers an efficient and accurate means for the quick computation of centrifugal compressor characteristics. This is of great significance for improving the efficiency of centrifugal compressors and reducing energy consumption.
基金the National Natural Science Foundation of China(Nos.51974032,52174355,51701c021,and 51604034)the Science and Technology Development Program of Jilin Province(No.20190302003GX)。
文摘1. Introduction Nanoprecipitation strengthening has always been a concern in steel materials, and this approach is one of the most proven and effective strengthening methods [1–3]. However, the increase in strength due to the nanoprecipitates often corresponds to a decrease in ductility [4,5], and this conflicting relationship between strength and ductility has attracted the attention of researchers,who have sought to find a balance between strength and ductility [6–8].
文摘Working memory（WM）allows humans to hold necessary information in temporary storage and manipulate such information online for higher-order cognitive functions,such as language understanding,decision making,and problem solving.Since its first appearance in the science of psychology in the 1960s,many theories have sought to elucidate the nature of WM.The most accepted model is
基金supported by the National Key Research&Development Program of China,Nos.2021YFC2501205(to YC),2022YFC24069004(to JL)the STI2030-Major Project,Nos.2021ZD0201101(to YC),2022ZD0211800(to YH)+2 种基金the National Natural Science Foundation of China(Major International Joint Research Project),No.82020108013(to YH)the Sino-German Center for Research Promotion,No.M-0759(to YH)a grant from Beijing Municipal Science&Technology Commission(Beijing Brain Initiative),No.Z201100005520018(to JL)。
文摘Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is known about the long-term stability of these biomarker proteins in plasma samples stored at-80°C.We aimed to explore how storage time would affect the diagnostic accuracy of these biomarkers using a large cohort.Plasma samples from 229 cognitively unimpaired individuals,encompassing healthy controls and those experiencing subjective cognitive decline,as well as 99 patients with cognitive impairment,comprising those with mild cognitive impairment and dementia,were acquired from the Sino Longitudinal Study on Cognitive Decline project.These samples were stored at-80°C for up to 6 years before being used in this study.Our results showed that plasma levels of Aβ42,Aβ40,neurofilament light chain,and glial fibrillary acidic protein were not significantly correlated with sample storage time.However,the level of total tau showed a negative correlation with sample storage time.Notably,in individuals without cognitive impairment,plasma levels of total protein and tau phosphorylated protein threonine 181(p-tau181)also showed a negative correlation with sample storage time.This was not observed in individuals with cognitive impairment.Consequently,we speculate that the diagnostic accuracy of plasma p-tau181 and the p-tau181 to total tau ratio may be influenced by sample storage time.Therefore,caution is advised when using these plasma biomarkers for the identification of neurodegenerative diseases,such as Alzheimer's disease.Furthermore,in cohort studies,it is important to consider the impact of storage time on the overall results.
基金supported by grants from the National Postdoctoral Science Foundation,China(2014M552219)the Natural Science Foundation of Guangdong Province,China(2015 A030313889,2015A030401013,2014A030313709,and 2014A030 313710)+1 种基金the Science and Technology Planning Project of Shenzhen Municipality,China(ZDSYS201504301045406,JCYJ20150403110 829621,JCYJ20150403091443301,JCYJ20140415162542975,JCYJ 20140415162338855,JCYJ20140828163634004,and JCYJ201206 16144352139)the Health and Family Planning Commission Project of Shenzhen Municipality,China(201401026)
文摘Abstract The dopamine transporter （DAT） is involved in the regulation of extracellular dopamine levels. A 40-bp variable-number tandem repeat （VNTR） polymorphism in the 3-untranslated region （3UTR） of the DAT has been reported to be associated with various phenotypes that are involved in the aberrant regulation of dopaminergic neu- rotransmission. In the present study, we found that miR- 137 and miR-491 caused a marked reduction of DAT expression, thereby influencing neuronal dopamine trans- port. Moreover, the regulation of miR-137 and miR-491 on this transport disappeared after the DAT was silenced. The miR-491 seed region that is located on the VNTR sequence in the 3＇UTR of the DAT and the regulatory effect of miR- 491 on the DAT depended on the VNTR copy-number. These data indicate that miR-137 and miR-491 regulate DAT expression and dopamine transport at the post- transcriptional level, suggesting that microRNA may be targeted for the treatment of diseases associated with DAT dysfunction.
基金supported by the National Natural Science Foundation of China(82102018,62333002,T2425027,and 82327809)Data collection and sharing for this project were supported by the National Natural Science Foundation of China(61633018,81571062,81471120,and 81901101)+30 种基金Data collection and sharing for this project were funded by the ADNI(National Institutes of Health Grant U01 AG024904)the Department of Defense ADNI(award number W81XWH-12-2-0012).The ADNI is funded by the National Institute on Aging,the National Institute of Biomedical Imaging and Bioengineering,and through generous contributions from the following:AbbVie,Alzheimer’s AssociationAlzheimer’s Drug Discovery FoundationAraclon BiotechBioClinica,Inc.BiogenBristol-Myers Squibb Co.CereSpir,Inc.CogstateEisai Inc.Elan Pharmaceuticals,Inc.Eli Lilly and Co.EuroImmunF.Hoffmann-La Roche Ltd and its affiliated company Genentech,Inc.FujirebioG.E.HealthcareIXICO Ltd.Janssen Alzheimer Immunotherapy Research&Development,LLC.Johnson&Johnson Pharmaceutical Research&Development LLC.LumosityLundbeckMerck&Co.,Inc.Meso Scale Diagnostics,LLC.NeuroRx ResearchNeurotrack TechnologiesNovartis Pharmaceuticals Corp.Pfizer Inc.Piramal ImagingServierTakeda Pharmaceutical Co.and Transition Therapeutics.The Canadian Institutes of Health Research provides funds to support ADNI clinical sites in Canada.Private sector contributions are facilitated by the Foundation for the National Institutes of Health(www.fnih.org).The grantee organization was the Northern California Institute for Research and Education,and the study was coordinated by the Alzheimer’s Therapeutic Research Institute at the University of Southern California.ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of Southern California.
文摘Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity of pathology,potentially hindering clinical trials in the development of medical treatment.Brain-based subtyping studies utilize magnetic resonance imaging(MRI)and data-driven methods to discover the subtypes of diseases,providing a new perspective on disease heterogeneity.
基金the National Natural Science Foundation of China(Nos.22171272,22031010)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0520302)the Youth Innovation Promotion Association CAS(No.2021035)for financial support。
文摘Supramolecular luminescent materials(SLMs)exhibit exceptional luminescence properties and the ability to be intelligently regulated through diverse assembly approaches,making them highly attractive in the field of luminescent materials.In recent years,the novel macrocyclic arenes characterized by unique electron-rich structures,ease of derivatization,tunable conformations and even inherent luminescence properties afford much opportunities to create such dynamic smart luminescent materials.The incorporation of macrocyclic arenes into SLMs leads to simple preparation process,diverse photophysical phenomena and sophisticated regulatory mechanisms,which is also currently one of the most frontier and hot topics in macrocyclic and supramolecular chemistry and even luminescent materials.In this review,the research advances in construction and applications of SLMs based on macrocyclic arenes in the last several years will be presented from the different assembly strategies,including host-vip complexes,supramolecular polymers,nanoparticles,and other assemblies.Moreover,some insights into future directions for this research area will also be offered.
基金Supported by Capital Medical University Affiliated Beijing Shijitan Hospital Talent Development Program during the 14th Five-Year Plan,No.2023 LJRCLFQ.
文摘BACKGROUND Wedged hepatic venous pressure(WHVP)is a crucial variable for accurately assessing the hepatic venous pressure gradient(HVPG)and is vital for the diagnosis and prognostic evaluation of patients with portal hypertension(PH).AIM To investigate the anatomical characteristics of balloon-occluded hepatic venous angiography in patients with PH and analyze the relationship between the WHVP and portal venous pressure(PVP).METHODS This retrospective study included 877 patients with PH who met the inclusion criteria from January 2020 to June 2024.Routine and innovative hepatic venous angiography was performed during transjugular intrahepatic portosystemic shunt procedures to measure hepatic venous and PVPs.All patients'angiographic images were collected for analysis.The associations between WHVP and PVP in each group were analyzed via linear regression analysis,and a predictive model was established.RESULTS The 877 patients had a mean age of 52.6±13.0 years,with 582 males and 295 females.Patients were categorized into four groups on the basis of their anatomical structure.All groups showed strong correlations between WHVP and PVP.The regression coefficient between the WHVP and PVP in the hepatic right vein-portal venous angiography group was 0.884(P<0.05);in the hepatic right vein-accessory hepatic venous angiography group,it was 0.721(P<0.05);in the hepatic right vein-middle hepatic venous angiography group,it was 0.344(P<0.05);and in the hepatic right vein-nonangiography group,it was 0.293(P<0.05).CONCLUSION The presence and anatomical classification of hepatic venous collaterals are key factors influencing the relationship between WHVP with and PVP.Based on the different anatomical classifications of hepatic veins,WHVP can be used to estimate PVP,improving the accuracy of PVP prediction.
