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This study was to explore the role of ELOVL6 in the development of head and neck squamous cell carcinoma (HNSCC). Considering its previously identified oncogenic role in hepatocellular carcinoma. ELOVL6 gene expression, clinicopathological analysis, enrichment analysis, and immune infiltration analysis were based on the data from Gene Expression Omnibus and The Cancer Genome Atlas, with additional bioinformatics analyses performed. Human HNSCC tissue microarray and cell lines were used. The expression of ELOVL6 in HNSCC was detected by quantitative polymerase chain reaction, immunohistochemistry assay, and western blot analysis. The proliferation ability of HNSCC cells, invasion, and apoptosis were evaluated using cell counting kit-8 method, Transwell assay, and flow cytometry, respectively. Based on the data derived from the cancer databases and our HNSCC cell and tissue studies, we found that ELOVL6 was overexpressed in HNSCC. Moreover, ELOVL6 expression level had a positive correlation with clinicopathology of HNSCC. Gene set enrichment analysis showed that ELOVL6 affected the occurrence of HNSCC through WNT signaling pathway. Functional experiments demonstrated that ELOVL6 knockdown inhibited the proliferation and invasion of HNSCC cells while promoting apoptosis. Additionally, compound 3f, an agonist of WNT/ß-catenin signaling pathway, enhances the effect of ELOVL6 on the progression of HNSCC cells. ELOVL6 is upregulated in HNSCC and promotes the development of HNSCC cells by inducing WNT/ß-catenin signaling pathway. ELOVL6 stands a potential target for the treatment of HNSCC and a prognosis indicator of human HNSCC.
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Elongases de Ácidos Graxos , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço , Carcinoma de Células Escamosas de Cabeça e Pescoço , Via de Sinalização Wnt , Feminino , Humanos , Masculino , Apoptose , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/metabolismo , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Via de Sinalização Wnt/genéticaRESUMO
The ongoing Russia-Ukraine conflict serves as a prime illustration of geopolitical risk, manifesting implications beyond global energy price surges and regional energy deficits; it also resonates within the carbon trading market. This study delves into the non-linear and asymmetric impacts of geopolitical risk on oil-carbon linkages spanning 2013 to 2022. Commencing with an exploration of dynamic correlations within the carbon and crude oil markets, our findings indicate that market movements in carbon or crude oil are subject not only to their respective historical volatility trends but also to reciprocal influences from the alternate market, highlighting the existence of asymmetric spillovers between the carbon and crude oil markets. Subsequently, a threshold vector error correction model (TVECM) sheds light on the long-term transmission dynamics of geopolitical risk to oil-carbon linkages. It is concluded that the oil-carbon linkages have a limited impact on geopolitical risk and are subject to shocks from geopolitical risk. Finally, the maximum overlap discrete wavelet transform (MODWT) method unveils heterogeneity across temporal scales: in the short term, geopolitical risk fluctuations are influenced by oil-carbon linkages, and in the middle and long run it becomes independent. Such insights furnish investors with an enriched comprehension of the interplay between crude oil and carbon markets amid geopolitical disturbances, while also offering policymakers a foundation upon which to sculpt informed responses to geopolitical risk.
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Air pollution is very harmful to the industrial production and public health. Therefore, it is necessary to predict the air pollution and release air quality levels to provide guidance for public production and life. In most previous studies, pollutant data were directly used for predictions, which are rarely based on the structural characteristics of the data itself. Therefore, a novel combined forecasting structure based on the L1 norm was designed, aiming at pollution contaminant monitoring and analysis. It comprises analysis, forecast, and evaluation. Firstly, the original data are decomposed into several components. Subsequently, each component is expanded into a matrix time series by phase space reconstruction. The forecast module is then used to carry out the weighted combination of the prediction results of the three models based on the L1 norm to determine the final prediction result and the process parameters are optimized using the multi-tracker optimization algorithm. Moreover, comprehensive fuzzy evaluation was applied to qualitatively analyze the air quality. The daily pollution sources in three cities in China are taken as examples to verify the effectiveness and efficiency of the established combined forecasting structure. The results show that the architecture has a great application potential in the field of air quality prediction.
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Poluentes Atmosféricos , Poluição do Ar , China , Cidades , Monitoramento Ambiental , PrevisõesRESUMO
A rapid, specific and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of isofraxidin, rosmarinic acid and kaempferol-3-O-glucuronide in rat plasma using warfarin as an internal standard (IS). Separation was conducted on a Thermo Hypersil GOLD C18 column with linear gradient elution using methanol and water. Mass spectrometric detection was conducted using selected reaction monitoring (SRM) via an electrospray ionization (ESI) source. All analytes exhibited good linearity within their concentration ranges (r > 0.9990). The lower limits of quantitations of isofraxidin, rosmarinic acid, and kaempferol-3-O-glucuronide were 1.31, 0.67 and 0.92 ng/mL, respectively. Intra- and inter-day precisions of these investigated components exhibited an RSD within 11.7%, and the accuracy ranged from -12.5 to 15.0% at all QC levels. The developed method was successfully applied to a pharmacokinetic study of isofraxidin, rosmarinic acid, and kaempferol-3-O-glucuronide in rats after oral administration of Herba Sarcandrae Extract.
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Cromatografia Líquida/métodos , Medicamentos de Ervas Chinesas/farmacocinética , Extratos Vegetais/farmacocinética , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Calibragem , Cinamatos/sangue , Cumarínicos/sangue , Depsídeos/sangue , Medicamentos de Ervas Chinesas/administração & dosagem , Glucuronídeos/sangue , Quempferóis/sangue , Limite de Detecção , Magnoliopsida/química , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/sangue , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray/métodos , Varfarina/sangue , Ácido RosmarínicoRESUMO
Integrating photocatalytic oxidation for pollutant removal with hydrogen production via photocatalysis presents a promising approach for sustainable water purification and renewable energy generation, circumventing the sluggish multi-electron transfer inherent in photocatalytic water oxidation. This study introduces novel zero-/one-dimensional (0D/1D) CuWO4/Mn0.3Cd0.7S step-scheme (S-scheme) heterojunctions that exhibit exceptional bifunctional capabilities in photocatalytic degradation and hydrogen production under full-spectrum illumination. The degradation efficiency for tetracycline (TC) using 5 %-CuWO4/Mn0.3Cd0.7S reaches 94.3 % and 94.5 % within 60 min and 6 h, respectively, under ultraviolet-visible (UV-Vis) and near-infrared (NIR) light. Notably, these 0D/1D CuWO4/Mn0.3Cd0.7S S-scheme heterojunctions demonstrate superior hydrogen production, achieving rates of 12442.03 µL g-1h-1 and 2418.54 µL g-1h-1 under UV-Vis light and NIR light irradiation, respectively-these rates are 2.3 times and 55.2 times higher than that of Mn0.3Cd0.7S alone. This performance enhancement is attributed to the intrinsic dimensional effects, transitions of transition metal d-d orbitals, and S-scheme hole/electron (h+/e-) separation characteristics. Additionally, experimental results and density functional theory (DFT) calculations have clarified the modulation of electronic configurations, band alignment, and interfacial interactions via 0D/1D S-scheme heterojunction engineering. This study sheds light on the electron transfer mechanism within S-scheme heterojunction and enhances the effectiveness, economy, and sustainability of recalcitrant pollutant removal and hydrogen production.
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Magnesium matrix composites are essential lightweight metal matrix composites, following aluminum matrix composites, with outstanding application prospects in automotive, aerospace lightweight and biomedical materials because of their high specific strength, low density and specific stiffness, good casting performance and rich resources. However, the inherent low plasticity and poor fatigue resistance of magnesium hamper its further application to a certain extent. Many researchers have tried many strengthening methods to improve the properties of magnesium alloys, while the relationship between wear resistance and plasticity still needs to be further improved. The nanoparticles added exhibit a good strengthening effect, especially the ceramic nanoparticles. Nanoparticle-reinforced magnesium matrix composites not only exhibit a high impact toughness, but also maintain the high strength and wear resistance of ceramic materials, effectively balancing the restriction between the strength and toughness. Therefore, this work aims to provide a review of the state of the art of research on the matrix, reinforcement, design, properties and potential applications of nano-reinforced phase-reinforced magnesium matrix composites (especially ceramic nanoparticle-reinforced ones). The conventional and potential matrices for the fabrication of magnesium matrix composites are introduced. The classification and influence of ceramic reinforcements are assessed, and the factors influencing interface bonding strength between reinforcements and matrix, regulation and design, performance and application are analyzed. Finally, the scope of future research in this field is discussed.
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As an important part of die steels, hot-work die steels are mainly used to manufacture molds made of solid metal or high-temperature liquid metal from heating to recrystallization temperature. In view of the requirements for mechanical properties and service life for hot-work die steel, it is conducive to improve the thermal fatigue resistance, wear resistance, and oxidation resistance of hot work die steel. In this review, the main failure modes of hot-work die steel were analyzed. Four traditional methods of strengthening and toughening die steel were summarized, including optimizing alloying elements, electroslag remelting, increasing the forging ratio, and heat treatment process enhancement. A new nano-strengthening method was introduced that aimed to refine the microstructure of hot-work abrasive steel and improve its service performance by adding nanoparticles into molten steel to achieve uniform dispersion. This review provides an overview to improve the service performance and service life of hot work die steel.
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It is well known that the development of lightweight alloys with improved comprehensive performance and application value are the future development directions for the ultra-high-strength 7xxx series Al-Zn-Mg-Cu alloys used in the aircraft field. As the lightest metal element in nature, lithium (Li) has outstanding advantages in reducing the density and increasing the elastic modulus in aluminum alloys, so Al-Zn-Mg-Cu alloys containing Li have gained widespread attention. Furthermore, since the Al-Zn-Mg-Cu alloy is usually strengthened by aging treatment, it is crucial to understand how Li addition affects its aging precipitation process. As such, in this article, the effects and mechanism of Li on the aging precipitation behavior and the impact of Li content on the aging precipitation phase of Al-Zn-Mg-Cu alloys are briefly reviewed, and the influence of Li on the service properties, including mechanical properties, wear resistance, and fatigue resistance, of Al-Zn-Mg-Cu alloys are explained. In addition, the corresponding development prospects and challenges of the Al-Zn-Mg-Cu-Li alloy are also proposed. This review is helpful to further understand the role of Li in Al-Zn-Mg-Cu alloys and provides a reference for the development of high-strength aluminum alloys containing Li with good comprehensive properties.
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In the general environment of lightweight automobiles, the integrated die-casting technology proposed by Tesla has become the general mode to better achieve weight reduction in automobiles. The die-casting mold required by integrated die-casting technology has the characteristics of large scale and complexity. Hence, higher requirements are put forward for the comprehensive performance of the die steel. Despite the stagnation in the progress of conventional strengthening methods, enhancing the performance of die steel has become increasingly challenging. Indeed, it necessitates exploring novel die steel and optimizing heat treatment and reinforcement technologies. This article summarizes and analyzes the development status of die steel and corresponding heat treatment and microstructure manipulation as well as strengthening methods and elaborates on an excellent nano-strengthening technology. Furthermore, this review will aid researchers in establishing a comprehensive understanding of the development status of die steel and the processes utilized for its strengthening. It will also assist them in developing die steel with improved comprehensive performance to meet the high demand for mold steel in the integrated die-casting technology of the new era.
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In this work, a high strength-ductility Ti64 cast alloy, containing trace TiC-TiB2 nanoparticles, was fabricated by adding dual-phased nano-TiC-TiB2/Al master alloys to the molten Ti64 alloys. The trace addition of the TiC-TiB2 nanoparticles (0.1 wt%) simultaneously reduced the size of the ß grains, the α laths, and the α colony size of the lamellar structure during casting and suppressed the coarsening of the α laths during heat treatment. The yield strength and the uniform elongation of TiC-TiB2/Ti64 were increased by ~130 MPa and 2%, respectively. The simultaneously improved strength and ductility of the TiC-TiB2/Ti64 were attributed to the decrease in the α colony size of the lamellar structure, the significant refinement of the grains and α laths, and the pinning effect of nanoparticles.
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It is widely known that the special performances and extensive applications of the nanoscale materials are determined by their as-synthesized structures, especially their growth sizes and morphologies. Hereinto, titanium carbides, which show brilliant comprehensive properties, have attracted considerable attention from researchers. How to give full play to their potentials in the light-weight manufacture, microwave absorption, electromagnetic protection, energy conversion and catalyst areas has been widely studied. In this summarized article, the synthesis methods and mechanisms, corresponding growth morphologies of titanium carbides and their further applications were briefly reviewed and analyzed according to their different morphological dimensions, including one-dimensional nanostructures, two-dimensional nanosheets and three-dimensional nanoparticles. It is believed that through the investigation of the crystal structures, synthesis methods, growth mechanisms, and morphology characterizations of those titanium carbides, new lights could be shed on the regulation and control of the ceramic phase specific morphologies to meet with their excellent properties and applications. In addition, the corresponding development prospects and challenges of titanium carbides with various growth morphologies were also summarized.
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The aim of the present study was to observe the effects of cytokine signaling suppressor 1 (SOCS1)-silenced dendritic cells (DCs) pulsed with epidermal growth factor receptor (EGFR) fusion protein on the activation of T lymphocyte and cytotoxic T-lymphocyte (CTL) activity against Hep-2 cells. DCs were derived from the medullary cells of mice and authenticated by flow cytometry (FCM). Recombinant glutathione-S-transferase (GST)-EGFR fusion protein was produced and purified. After being pulsed with it, DCs were modified by recombinant SOCS1-siRNA adenoviral to silence SOCS1 gene expression. The maturation of DCs was evaluated by FCM. The effects of modified DCs on T-cell proliferation were assessed by MTT assay. The killing effects against Hep-2 cells of CTL were assessed by lactate dehydrogenase (LDH) release assay. High-purity DCs from the medullary cells of mice were obtained. Compared with the control, EGFR-pulsed DCs displayed higher expression of cell surface molecules, including CD83, CD860 and HLA-DR. The MTT assay revealed that all of the EGFR-pulsed, SOCS1silenced and EGFR-pulsed plus SOCS1-silenced DCs had an enhanced capacity to stimulate T-lymphocyte proliferation. As expected, EGFR-pulsed plus SOCS1-silenced DCs had the strongest effects on T-cell proliferation. The splenic T cells isolated from both EGFR-pulsed DC-immunized mice and EGFR-pulsed plus SOCS1-silenced DC-immunized mice enhanced the cytotoxicity against Hep-2 cells, while T cells from EGFRpulsed plus SOCS1-silenced DC-immunized mice exhibited significantly higher cytotoxicity than those from EGFR-DC-immunized mice. The EGFR-pulsed SOCS1siRNA-silenced DCs had the strongest effects on activation of T-cell proliferation and the CTL activity against Hep-2 cells.
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Citotoxicidade Imunológica/imunologia , Células Dendríticas/imunologia , Receptores ErbB/metabolismo , Neoplasias Laríngeas/patologia , Proteínas Recombinantes de Fusão/metabolismo , Proteína 1 Supressora da Sinalização de Citocina/antagonistas & inibidores , Linfócitos T Citotóxicos/imunologia , Adenoviridae , Animais , Apoptose , Proliferação de Células , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Receptores ErbB/genética , Humanos , Técnicas In Vitro , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/imunologia , Masculino , Camundongos , Camundongos SCID , RNA Interferente Pequeno/genética , Proteínas Recombinantes de Fusão/genética , Proteína 1 Supressora da Sinalização de Citocina/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: To investigate the effects of Deoxygedunin on Aß deposition, learning memory, and oxidative stress induced by D-galactose combined with AlCl3 in model rats with Alzheimer's disease and its possible mechanism. METHODS: Male SD rats were randomly divided into three groups (n=12):control group, model group (AD) and intervention group (AD+Deo). Morris water maze test was used to detect learning/memory and cognitive function in rats.Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and malondialdehyde (MDA) contents in homogenate of hippocampus were detected by enzyme-linked immunosorbent assay (ELISA).Tau protein expression in rat cerebral cortex was detected by immunohistochemistry.Western blot was used to detect the expressions of extracellular signal regulated kinase 1(ERK1), protein kinase B (PKB) and tropomyosin-related kinase B (TrkB) on TrkB signaling pathway. RESULTS: The results of water maze test showed that D-galactose combined with AlCl3 induced a significant increase in the escape latency compared with the control group (P<0.05).Deoxygedunin could reverse the increase of the escape latency of the model group (P<0.05).On the 7th day after removal of the platform, the model group showed an increase in escape latency compared with the control group and the intervention group (P<0.01), and the number of crossing platforms was declined (P<0.05); The results of immunohistochemistry and ELISA showed that the expressions of Aß and tau protein in the model group were increased significantly compared with those of the control group (P<0.01).The activities of SOD and GSH-Px were decreased significantly and the content of MDA was increased significantly.Compared with the model group, Deoxygedunin could reverse the increase of the expressions of Aß and tau protein (P<0.01), the decrease of SOD and GSH-Px activities (P<0.05) and the increase of the MDA content (P<0.05).Western blot results showed that Deoxygedunin treatment reversed the decreased phosphorylation levels of TrkB, AKT and ERK1 in hippocampus of the model group. CONCLUSIONS: Supplement of Deoxygedunin can significantly reverse Aß deposition, oxidative stress and cognitive deficits by activating the TrkB signal transduction pathway, which suggest that Deoxygedunin may serve as a promising therapeutic candidate for attenuating AD-like pathological dysfunction induced by D-galactose combined with AlCl3.
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Doença de Alzheimer , Limoninas , Doença de Alzheimer/induzido quimicamente , Animais , Modelos Animais de Doenças , Galactose , Hipocampo , Masculino , Aprendizagem em Labirinto , Ratos , Ratos Sprague-DawleyRESUMO
ZnS nanoparticles are in situ grown on reduced graphene oxides (rGO) via a simplified one-step hydrothermal method. Sodium carboxymethyl cellulose (CMC) is firstly applied as the binder for ZnS based anodes and shows a more advantageous binding effect than PVDF. To simplify the synthesis procedure, l-cysteine is added as the sulfur source for ZnS and simultaneously as the reducing agent for rGO. The average diameter of ZnS nanoparticles is measured to be 13.4 nm, and they uniformly disperse on the rGO sheets without any obvious aggregation. As anode materials, the CMC bound ZnS-rGO nanocomposites can maintain a high discharge capacity of 705 mA h g-1 at a current density of 500 mA g-1 for 150 cycles. The significantly improved electrochemical performance mainly derives from the combined effects of the small and uniformly dispersed ZnS nanoparticles, the high conductivity and structural flexibility of rGO and the strong binding ability of CMC.
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A high extrusion ratio of 166:1 was applied to commercial AZ61 alloy in one step with an extrusion speed of 2.1 m·min-1. The effects of DA (direct aging) treatment on the microstructure and tensile properties of extruded alloy were investigated. The extruded alloy exhibits fine DRXed grains and the average grain size is ~11 µm. After DA treatment at 170 °C, the tensile strength and 0.2% offset yield strength is enhanced from 314 to 336 MPa and from 169 to 191 MPa respectively, sacrificing elongation from 26.5% to 23.3%. The grain size and texture distribution of extruded AZ61 scarcely evolve during the post aging treatment. However, the enhanced strength in peak-aged alloy is mainly caused by the high-density elliptical Mg17Al12 precipitates distributing uniformly along the grain boundaries or within the grains, by precipitation and dispersion hardening. Furthermore, the nano-sized precipitates effectively inhibit grains from coarsening by triggering pinning effects along the grain boundaries at elevated temperature. As a result, the peak-aged alloy exhibits a better superplasticity of 306.5% compared with that of 231.8% of extruded sample. This work provides a practical one-step method for mass-producing Mg alloy sheets with excellent tensile strength and ductility compared with those fabricated by conventional extrusion methods.
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The in situ TiC/Al-Cu nanocomposites were fabricated in the Al-Ti-C reaction systems with various carbon sources by the combined method of combustion synthesis, hot pressing, and hot extrusion. The carbon sources used in this paper were the pure C black, hybrid carbon source (50 wt.% C black + 50 wt.% CNTs) and pure CNTs. The average sizes of nano-TiC particles range from 67 nm to 239 nm. The TiC/Al-Cu nanocomposites fabricated by the hybrid carbon source showed more homogenously distributed nano-TiC particles, higher tensile strength and hardness, and better abrasive wear resistance than those of the nanocomposites fabricated by pure C black and pure CNTs. As the nano-TiC particles content increased, the tensile strength, hardness, and the abrasive wear resistance of the nanocomposites increased. The 30 vol.% TiC/Al-Cu nanocomposite fabricated by the hybrid carbon source showed the highest yield strength (531 MPa), tensile strength (656 MPa), hardness (331.2 HV), and the best abrasive wear resistance.
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Bimodal hybrid in-situ nano-/micro-size TiC/Al composites were prepared with combustion synthesis of Al-Ti-C system and hot press consolidation. Attempt was made to obtain in-situ bimodal-size TiC particle reinforced dense Al matrix composites by using different carbon sources in the reaction process of hot pressing forming. Microstructure showed that the obtained composites exhibited reasonable bimodal-sized TiC distribution in the matrix and low porosity. With the increasing of the carbon nano tube (CNT) content from 0 to 100 wt. %, the average size of the TiC particles decreases and the compressive strength of the composite increase; while the fracture strain increases first and then decreases. The compressive properties of the bimodal-sized TiC/Al composites, especially the bimodal-sized composite synthesized by Al-Ti-C with 50 wt. % CNTs as carbon source, were improved compared with the composites reinforced with single sized TiC. The strengthening mechanism of the in-situ bimodal-sized particle reinforced aluminum matrix composites was revealed.
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With the Paris Agreement coming into effect, China, as the largest CO2 emitter in the world, will be facing greater pressure to reduce its carbon emissions. This paper discusses how to solve this issue from the perspective of financial development in China. Although many studies have analyzed its impact on carbon emissions, the conclusions are contradictory. A major criticism of the existing studies is the reasonability of the selection of appropriate indicators and panel estimation techniques. Almost all studies use only one or limited indicators to represent the financial development and ignore the cross-sectional dependence. To fulfil the gaps mentioned above, a financial development index system is built, and with the framework of the STIRPAT (Stochastic impacts by regression on population, affluence, and technology) model, this paper applies an ARDL approach to investigating the long-run relationship between financial development and carbon emissions and a dynamic panel error-corrected model to capture the short-run impact. The empirical results show that financial development can improve carbon emissions, and such impact not only shows a regional difference but also reflects the features of stage differences. Additionally, based on the discussion on seven specific aspects of financial development, our findings can be helpful for policy makers to enact corresponding policies to realize the goal of reducing carbon emissions in China.
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Desenvolvimento Econômico/estatística & dados numéricos , Modelos Estatísticos , Emissões de Veículos/prevenção & controle , China , Estudos TransversaisRESUMO
The tensile creep behavior of Al-Cu-Mg alloy and its composite containing in situ nano-sized TiCx were explored at temperatures of 493 K, 533 K and 573 K with the applied stresses in the range of 40 to 100 MPa. The composite reinforced by nano-sized TiCx particles exhibited excellent creep resistance ability, which was about 4-15 times higher than those of the unreinforced matrix alloy. The stress exponent of 5 was noticed for both Al-Cu-Mg alloy and its composite, which suggested that their creep behavior was related to dislocation climb mechanism. During deformation at elevated temperatures, the enhanced creep resistance of the composite was mainly attributed to two aspects: (a) Orowan strengthening and grain boundary (GB) strengthening induced by nano-sized TiCx particles, (b) θ' and S' precipitates strengthening.
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Nano-sized ceramic particle reinforced aluminum composites exhibit excellent room-temperature mechanical properties. However, there is limited research on the dry sliding wear behavior of those composites at elevated temperatures, which should be one of the major concerns on elevated temperature applications. Here the Al-Cu composites reinforced with nano-sized TiCp were fabricated. The dry sliding wear behaviors of the nano-sized TiCp/Al-Cu composites at various temperatures (140-220 °C) and loads (10-40 N) with different TiCp contents were studied, and the results showed that the nanocomposites exhibited superior wear resistance. For instance, the relative wear resistance of the 0.5 wt.% nano-sized TiCp/Al-Cu composite was 83.5% higher than that of the Al-Cu matrix alloy at 180 °C under 20 N, and was also 16.5% higher than that of the 5 wt.% micro-sized TiCp/Al-Cu composite, attributed to the pronounced Orowan strengthening effect of nanoparticles. The wear rates of the nanocomposites were always lower than those of the Al-Cu matrix alloy under the same test condition, which increased with the increase in temperature and load and with the decrease in TiCp content.