BACKGROUND Obesity in children and adolescents is a serious problem,and the efficacy of exercise therapy for these patients is controversial.AIM To assess the efficacy of exercise training on overweight and obese chil...BACKGROUND Obesity in children and adolescents is a serious problem,and the efficacy of exercise therapy for these patients is controversial.AIM To assess the efficacy of exercise training on overweight and obese children based on glucose metabolism indicators and inflammatory markers.METHODS The PubMed,Web of Science,and Embase databases were searched for randomized controlled trials related to exercise training and obese children until October 2023.The meta-analysis was conducted using RevMan 5.3 software to evaluate the efficacy of exercise therapy on glucose metabolism indicators and inflammatory markers in obese children.RESULTS In total,1010 patients from 28 studies were included.Exercise therapy reduced the levels of fasting blood glucose(FBG)[standardized mean difference(SMD):-0.78;95%confidence interval(CI):-1.24 to-0.32,P=0.0008],fasting insulin(FINS)(SMD:-1.55;95%CI:-2.12 to-0.98,P<0.00001),homeostatic model assessment for insulin resistance(HOMA-IR)(SMD:-1.58;95%CI:-2.20 to-0.97,P<0.00001),interleukin-6(IL-6)(SMD:-1.31;95%CI:-2.07 to-0.55,P=0.0007),C-reactive protein(CRP)(SMD:-0.64;95%CI:-1.21 to-0.08,P=0.03),and leptin(SMD:-3.43;95%CI:-5.82 to-1.05,P=0.005)in overweight and obese children.Exercise training increased adiponectin levels(SMD:1.24;95%CI:0.30 to 2.18,P=0.01)but did not improve tumor necrosis factor-alpha(TNF-α)levels(SMD:-0.80;95%CI:-1.77 to 0.18,P=0.11).CONCLUSION In summary,exercise therapy improves glucose metabolism by reducing levels of FBG,FINS,HOMA-IR,as well as improves inflammatory status by reducing levels of IL-6,CRP,leptin,and increasing levels of adiponectin in overweight and obese children.There was no statistically significant effect between exercise training and levels of TNF-α.Additional long-term trials should be conducted to explore this therapeutic perspective and confirm these results.展开更多
Intermetallic phases were found to influence the anodic oxidation and corrosion behavior of 5A06 aluminum alloy. Scattered in- termetallic particles were examined by scanning electron microscopy (SEM) and energy dis...Intermetallic phases were found to influence the anodic oxidation and corrosion behavior of 5A06 aluminum alloy. Scattered in- termetallic particles were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after pretreatment. The anodic film was investigated by transmission electron microscopy (TEM), and its corrosion resistance was analyzed by electrochemical impedance spectroscopy (EIS) and Tafel polarization in NaC1 solution. The results show that the size of A1-Fe-Mg-Mn particles gradually decreases with the iron content. During anodizing, these intermetallic particles are gradually dissolved, leading to the complex porosity in the anodic film beneath the particles. After anodizing, the residual particles are mainly silicon-containing phases, which are embedded in the an- odic film. Electrochemical measurements indicate that the porous anodic film layer is easily penetrated, and the barrier plays a dominant role in the overall protection. Meanwhile, self-healing behavior is observed during the long immersion time.展开更多
The effects of cupric ions on the corrosion behavior of aluminum alloy 5A02 in ethylene glycol–water solutions were studied by potentiodynamic polarization,electrochemical noise(EN),and complementary techniques inclu...The effects of cupric ions on the corrosion behavior of aluminum alloy 5A02 in ethylene glycol–water solutions were studied by potentiodynamic polarization,electrochemical noise(EN),and complementary techniques including scanning electron microscopy(SEM),atomic force microscopy(AFM),and X-ray photoelectron spectroscopy(XPS). A positive corrosion potential and increased corrosion current were observed due to the deposition of copper. The results demonstrate that the main corrosion type was pitting and the increasing cupric ion concentration augmented the pitting density. The pits became larger and deeper as a result of the embedment of copper into the surface of the alloy. Cupric ions were preferentially deposited at the defects around the secondary phase,leading to the formation of Al–Cu microgalvanic couples,which increased the corrosion rate. The corrosion rate gradually reached a stable value as the concentration of cupric ions was increased beyond 10 mmol/L.展开更多
In-site regenerated titanium dioxide-activated carbon fibers (TiO2-ACFs) photocatalyst was prepared by the sol-gel method. De-tailed surface and structural characterization of the TiO2-ACFs photocatalyst was carried...In-site regenerated titanium dioxide-activated carbon fibers (TiO2-ACFs) photocatalyst was prepared by the sol-gel method. De-tailed surface and structural characterization of the TiO2-ACFs photocatalyst was carried out. The photoactivity of TiO2-ACFs under ultra-violet irradiation was compared with original ACFs and pure TiO2 by the degradation of methylene blue aqueous solution. The degradation efficiency by the TiO2 (5wt%)-ACFs sample is much higher than that by TiO2 and ACFs. The results show that the photocatalysis by TiO2-ACFs is a six-step process. The adsorption-transfer-photocatalysis rate of TiO2-ACFs is higher than the adsorption-photocatalysis rate of TiO2, so the photocatalysis rate of the TiO2-ACFs system is higher than that of TiO2 photocatalyst.展开更多
Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sintering(SPS). The structure and mechanical properties of the composites were investigated. Testi...Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sintering(SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide(Al_4C_3) is not formed during SPS processing. Further addition of graphene(above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.展开更多
The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The ano...The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.展开更多
Bio-mineralization has been explored to synthesize nanomaterials with exquisite structures and amazing properties.Amino-acids-functionalized filamentous M13 virus was applied as a scaffold for the synthesis of silver ...Bio-mineralization has been explored to synthesize nanomaterials with exquisite structures and amazing properties.Amino-acids-functionalized filamentous M13 virus was applied as a scaffold for the synthesis of silver and silver sulfide nanoparticles.It is interesting to find that the binding affinity between filamentous M13virus and silver ions can be effectively improved after a friendly modification by amino acids.At the same time,amino-acids-modified filamentous M13 virus also serves as a dispersant to decrease the size and increase the stability of silver nanoparticles.Both silver and silver sulfide nanoparticles with monodispersed size and uniform morphology can be fabricated by the direction of amino-acidmodified filamentous M13 virus.The successful synthesis of silver sulfide nanoparticles on amino-acids-modified filamentous M13 virus suggests that this approach is highly efficient to fabricate not only metal nanoparticles,but also binary or multinary compounds.展开更多
The influence of rust layers on the corrosion behavior of ultra-high strength steel 300M subjected to a simulated coastal atmosphere was investigated by corrosion weight loss, surface analysis techniques, and electroc...The influence of rust layers on the corrosion behavior of ultra-high strength steel 300M subjected to a simulated coastal atmosphere was investigated by corrosion weight loss, surface analysis techniques, and electrochemical methods. The results exhibit the presence of a large proportion of γ-FeOOH and α-FeOOH and a small amount of Fe3O4 in the outer rust layer. During the wet-dry cyclic process, the bonding performance and the density of outer rust layer deteriorate with the thickness of outer rust. The inner rust layer plays a main role on protectiveness, which can be attributed to the formation of an ultra-dense and adherent rust film with major constituent of α-FeOOH and α-Fe2O3 on the steel.展开更多
The electronic speckle pattern interferometer was used to in situ monitor the pitting corrosion of 304 stainless steel at anodic polarization. The pitting current and pitting current density of a single pit were obtai...The electronic speckle pattern interferometer was used to in situ monitor the pitting corrosion of 304 stainless steel at anodic polarization. The pitting current and pitting current density of a single pit were obtained. The pit growth was controlled by the corrosion products diffusion. The pit morphology was observed by a scanning electron microscope. The results showed that the pit was dish shaped, and the geometric parameters and pit growth time conformed to the function of Y = A + B1t + B2t2 + B3t3.展开更多
2024 aluminum alloys were consolidated by using spark plasma sintering(SPS) method,and then heat treated by solid solution treatment(SST) and aging treatment(AT) procedures.The average grain size of bulk samples sinte...2024 aluminum alloys were consolidated by using spark plasma sintering(SPS) method,and then heat treated by solid solution treatment(SST) and aging treatment(AT) procedures.The average grain size of bulk samples sintered with 5,20 and 50 μm powders was 3.72,4.73 and 8.11 μm,respectively.The difference between the average grain size and original powder size was attributed to the recrystallization during short sintering process.The number of the inclusion phases in these samples decreased after SST and increased after subsequent AT.Besides,it was observed that intergranular corrosion(IGC) cracks initiated from stable pits due to the electrochemical inhomogeneity between the intermetallic particles(IMPs) and the aluminum matrix(176.02,110.83 and 164.80 mV for as-SPS,as-SST and as-AT samples,respectively).Besides,the cracks would propagate along the grain boundaries(GBs) and bypass the IMPs at GBs during propagation.It was revealed that the sample after SST presented the best IGC resistance,and this was ascribed to the reduce of IMPs,both in size and number.展开更多
文摘BACKGROUND Obesity in children and adolescents is a serious problem,and the efficacy of exercise therapy for these patients is controversial.AIM To assess the efficacy of exercise training on overweight and obese children based on glucose metabolism indicators and inflammatory markers.METHODS The PubMed,Web of Science,and Embase databases were searched for randomized controlled trials related to exercise training and obese children until October 2023.The meta-analysis was conducted using RevMan 5.3 software to evaluate the efficacy of exercise therapy on glucose metabolism indicators and inflammatory markers in obese children.RESULTS In total,1010 patients from 28 studies were included.Exercise therapy reduced the levels of fasting blood glucose(FBG)[standardized mean difference(SMD):-0.78;95%confidence interval(CI):-1.24 to-0.32,P=0.0008],fasting insulin(FINS)(SMD:-1.55;95%CI:-2.12 to-0.98,P<0.00001),homeostatic model assessment for insulin resistance(HOMA-IR)(SMD:-1.58;95%CI:-2.20 to-0.97,P<0.00001),interleukin-6(IL-6)(SMD:-1.31;95%CI:-2.07 to-0.55,P=0.0007),C-reactive protein(CRP)(SMD:-0.64;95%CI:-1.21 to-0.08,P=0.03),and leptin(SMD:-3.43;95%CI:-5.82 to-1.05,P=0.005)in overweight and obese children.Exercise training increased adiponectin levels(SMD:1.24;95%CI:0.30 to 2.18,P=0.01)but did not improve tumor necrosis factor-alpha(TNF-α)levels(SMD:-0.80;95%CI:-1.77 to 0.18,P=0.11).CONCLUSION In summary,exercise therapy improves glucose metabolism by reducing levels of FBG,FINS,HOMA-IR,as well as improves inflammatory status by reducing levels of IL-6,CRP,leptin,and increasing levels of adiponectin in overweight and obese children.There was no statistically significant effect between exercise training and levels of TNF-α.Additional long-term trials should be conducted to explore this therapeutic perspective and confirm these results.
基金financially supported by the National Natural Science Foundation of China(No.51271012)
文摘Intermetallic phases were found to influence the anodic oxidation and corrosion behavior of 5A06 aluminum alloy. Scattered in- termetallic particles were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after pretreatment. The anodic film was investigated by transmission electron microscopy (TEM), and its corrosion resistance was analyzed by electrochemical impedance spectroscopy (EIS) and Tafel polarization in NaC1 solution. The results show that the size of A1-Fe-Mg-Mn particles gradually decreases with the iron content. During anodizing, these intermetallic particles are gradually dissolved, leading to the complex porosity in the anodic film beneath the particles. After anodizing, the residual particles are mainly silicon-containing phases, which are embedded in the an- odic film. Electrochemical measurements indicate that the porous anodic film layer is easily penetrated, and the barrier plays a dominant role in the overall protection. Meanwhile, self-healing behavior is observed during the long immersion time.
文摘The effects of cupric ions on the corrosion behavior of aluminum alloy 5A02 in ethylene glycol–water solutions were studied by potentiodynamic polarization,electrochemical noise(EN),and complementary techniques including scanning electron microscopy(SEM),atomic force microscopy(AFM),and X-ray photoelectron spectroscopy(XPS). A positive corrosion potential and increased corrosion current were observed due to the deposition of copper. The results demonstrate that the main corrosion type was pitting and the increasing cupric ion concentration augmented the pitting density. The pits became larger and deeper as a result of the embedment of copper into the surface of the alloy. Cupric ions were preferentially deposited at the defects around the secondary phase,leading to the formation of Al–Cu microgalvanic couples,which increased the corrosion rate. The corrosion rate gradually reached a stable value as the concentration of cupric ions was increased beyond 10 mmol/L.
文摘In-site regenerated titanium dioxide-activated carbon fibers (TiO2-ACFs) photocatalyst was prepared by the sol-gel method. De-tailed surface and structural characterization of the TiO2-ACFs photocatalyst was carried out. The photoactivity of TiO2-ACFs under ultra-violet irradiation was compared with original ACFs and pure TiO2 by the degradation of methylene blue aqueous solution. The degradation efficiency by the TiO2 (5wt%)-ACFs sample is much higher than that by TiO2 and ACFs. The results show that the photocatalysis by TiO2-ACFs is a six-step process. The adsorption-transfer-photocatalysis rate of TiO2-ACFs is higher than the adsorption-photocatalysis rate of TiO2, so the photocatalysis rate of the TiO2-ACFs system is higher than that of TiO2 photocatalyst.
基金financially supported by the National Natural Science Foundation of China (No. 51271012)
文摘Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sintering(SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide(Al_4C_3) is not formed during SPS processing. Further addition of graphene(above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.
基金financially supported by the National Nature Science Foundation of China (No. 21371019)the Aero Science Foundation of China (No. 2011ZE51057)
文摘The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in- vestigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25℃ and a con- stant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the ap- proximate ranges of 10~20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.
基金financially supported by the National Natural Science Foundation of China (Grant No. 51271012)。
文摘Bio-mineralization has been explored to synthesize nanomaterials with exquisite structures and amazing properties.Amino-acids-functionalized filamentous M13 virus was applied as a scaffold for the synthesis of silver and silver sulfide nanoparticles.It is interesting to find that the binding affinity between filamentous M13virus and silver ions can be effectively improved after a friendly modification by amino acids.At the same time,amino-acids-modified filamentous M13 virus also serves as a dispersant to decrease the size and increase the stability of silver nanoparticles.Both silver and silver sulfide nanoparticles with monodispersed size and uniform morphology can be fabricated by the direction of amino-acidmodified filamentous M13 virus.The successful synthesis of silver sulfide nanoparticles on amino-acids-modified filamentous M13 virus suggests that this approach is highly efficient to fabricate not only metal nanoparticles,but also binary or multinary compounds.
基金financially supported by the National Natural Science Foundation of China (No. 51171011)
文摘The influence of rust layers on the corrosion behavior of ultra-high strength steel 300M subjected to a simulated coastal atmosphere was investigated by corrosion weight loss, surface analysis techniques, and electrochemical methods. The results exhibit the presence of a large proportion of γ-FeOOH and α-FeOOH and a small amount of Fe3O4 in the outer rust layer. During the wet-dry cyclic process, the bonding performance and the density of outer rust layer deteriorate with the thickness of outer rust. The inner rust layer plays a main role on protectiveness, which can be attributed to the formation of an ultra-dense and adherent rust film with major constituent of α-FeOOH and α-Fe2O3 on the steel.
基金financially supported by the National Nature Science Foundation of China (No.51071083)
文摘The electronic speckle pattern interferometer was used to in situ monitor the pitting corrosion of 304 stainless steel at anodic polarization. The pitting current and pitting current density of a single pit were obtained. The pit growth was controlled by the corrosion products diffusion. The pit morphology was observed by a scanning electron microscope. The results showed that the pit was dish shaped, and the geometric parameters and pit growth time conformed to the function of Y = A + B1t + B2t2 + B3t3.
基金financially supported by the National Nature Science Foundations of China (Nos.51271012 and 51671013)。
文摘2024 aluminum alloys were consolidated by using spark plasma sintering(SPS) method,and then heat treated by solid solution treatment(SST) and aging treatment(AT) procedures.The average grain size of bulk samples sintered with 5,20 and 50 μm powders was 3.72,4.73 and 8.11 μm,respectively.The difference between the average grain size and original powder size was attributed to the recrystallization during short sintering process.The number of the inclusion phases in these samples decreased after SST and increased after subsequent AT.Besides,it was observed that intergranular corrosion(IGC) cracks initiated from stable pits due to the electrochemical inhomogeneity between the intermetallic particles(IMPs) and the aluminum matrix(176.02,110.83 and 164.80 mV for as-SPS,as-SST and as-AT samples,respectively).Besides,the cracks would propagate along the grain boundaries(GBs) and bypass the IMPs at GBs during propagation.It was revealed that the sample after SST presented the best IGC resistance,and this was ascribed to the reduce of IMPs,both in size and number.