Despite the fact that copper (Cu) is a vital micronutrient to maintain body function, high doses of Cu through environmental exposure damage various organs, especially the liver, which is the main ...metabolic organ. To investigate the influence of long-term Cu-induced toxicity on mitophagy and apoptosis in rat liver, 96 seven-month-old male Sprague-Dawley rats were fed TBCC for 24 weeks. The results revealed that exposure to high Cu concentrations could promote oxidative stress liver injury by increasing the hepatic function index (ALT, AST and ALP) and MDA content, while reducing the activity of antioxidant enzymes (T-SOD, GSH-Px and CAT) related to oxidative stress. Consistent with histopathological observations, proper dietary Cu (15–60 mg/kg) could improve antioxidant stress levels and induce a dose-dependent increase in the mRNA expression of mitophagy-related genes, whereas a high Cu concentration (120 mg/kg) could cause severe liver impairment and ultrastructural changes and a reduction in mitophagosomes, accompanied by downregulation of Atg5, Beclin1, Pink1, Parkin, NIX, P62 and LC3B. The expression of apoptosis-related genes (Bax, Bax/Bcl-2, Caspase3, Cytc and p53) and proteins (Caspase3 and p53) was upregulated with the addition of dietary Cu. The results demonstrated that an appropriate dose of TBCC could improve liver function by promoting mitophagy and Cu enzymes that play antioxidative roles, while the accumulation of excess Cu could induce liver lesions by enhancing apoptosis and inhibiting mitophagy pathways.
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•Long-term copper exposure induced oxidative damage and toxicity to rat liver by regulating mitophagy and apoptosis.•Copper exposure attenuated mitophagy through the p53-mediated apoptosis signaling pathway.•Mitophagy might be an adaptive stress response prior to apoptotic cell death.
Copper poses huge environmental and public health concerns due to its widespread and persistent use in the past several decades. Although it is well established that at higher levels copper causes ...nephrotoxicity, the exact mechanisms of its toxicity is not fully understood. Therefore, this experimental study for the first time investigates the potential molecular mechanisms including transcriptomics, metabolomics, serum biochemical, histopathological, cell apoptosis and autophagy in copper-induced renal toxicity in pigs. A total of 14 piglets were randomly assigned to two group (7 piglets per group) and treated with a standard diet (11 mg CuSO4 per kg of feed) and a high copper diet (250 mg CuSO4 per kg of feed). The results of serum biochemical tests and renal histopathology suggested that 250 mg/kg CuSO4 in the diet significantly increased serum creatinine (CREA) and induced renal tubular epithelial cell swelling. Results on transcriptomics and metabolomics showed alteration in 804 genes and 53 metabolites in kidneys of treated pigs, respectively. Combined analysis of transcriptomics and metabolomics indicated that different genes and metabolism pathways in kidneys of treated pigs were involved in glycerophospholipids metabolism and glycosphingolipid metabolism. Furthermore, copper induced mitochondrial apoptosis characterized by increased bax, bak, caspase 3, caspase 8 and caspase 9 expressions while decreased bcl-xl and bcl2/bax expression. Exposure to copper decreased the autophagic flux in terms of increased number of autophagosomes, beclin1 and LC3b/LC3a expression and p62 accumulation. These results indicated that the imbalance of glycosphingolipid metabolism, the impairment of autophagy and increase mitochondrial apoptosis play an important role in copper induced renal damage and are useful mechanisms to understand the mechanisms of copper nephrotoxicity.
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•Transcriptomics and metabolomics investigated nephrotoxicity induced by copper in pig.•Compound lipids metabolism was disrupted.•Copper induced mitochondrial apoptosis and decreased the autophagic flux.
The effects of high-energy electropulsing treatment (EPT) on the microhardness and corrosion behavior of the surface gradient oxide coating on the titanium alloy matrix were investigated using ...infrared thermoscope, micro-hardness, three-dimensional optical microscope, electrochemical work station, scanning electron microscope equipped with electron backscatter diffraction, X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Thermogravimetry analyzer. Results showed that the surface modification brings in surface strengthening effect and improved surface corrosion resistance performance (in the fluoridated acidified artificial saliva) of titanium alloy strips with outstanding bonding-strength oxide coating through EPT transition zone. Rapid recrystallization, grain growth and texture evolution of surface matrix alloy are present with increasing DAFA (distance from the anode) of EPT. In this process, microstructure/texture evolution influences the oxidation layer thickness and the oxidation rate with the relationship between these two parameters fitting the approximate positive linear equation and the turning trend located at 120mm DAFA. Compared with TG-traditional furnace heating process, the growth rate of oxidation under EPT is noticeably enhanced by two orders of magnitudes and surface oxide coating experiences a crystal transformation from anatase-TiO2 to rutile-TiO2. Ionization and acceleration of oxygen by EPT are put forward to discuss the accelerated growth and crystal transformation kinetics of the oxidation process. Therefore, improved surface wear resistance and anti-corrosion performance with a strong adherent gradient oxide coating on the titanium alloy strips surface can be achieved by highly-efficient EPT process which can be applied in biomedical applications.
Electroplastic rolling (ER) and conventional warm rolling (WR) were conducted on Mg–3Al–1Zn (AZ31) sheet to study, for the first time, the influence of pulsed electric current on the twinning ...behavior of magnesium alloy. The 101̅2 extension twins were found insensitive to the current. The primary 101̅1 contraction twins, in contrast, display higher number fraction of twinned grains and better Schmid behavior in ER than in WR. This difference indicates a special ‘athermal’ influence of the current, which probably originates from the improved strain accommodation due to enhanced prismatic activity. The distinctive twinning behavior is related to the improved rollability.
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Animals adjust their lipid metabolism states in response to pathogens infection. However, the underlying molecular mechanisms for how lipid metabolism responds to infection remain to be elusive. In ...this study, we assessed the temporal changes of lipid metabolism profiles during infection by an integrated transcriptomics and lipidomics analysis. Ergosterol is identified to be required for proper host defense to pathogens. Notably, ergosterol level is increased in the hemolymph upon bacterial infection. We show that the increase of ergosterol level by food supplement or genetic depletion of Acsl, a long-chain fatty acid-CoA synthetase, promotes host survival against bacterial challenges. Together, our results suggest a critical role of lipid metabolism adaption in the process of host defense against invading pathogens.
Microcapsules with thermal energy storage and UV-shielding functions were successfully prepared by the method of suspension-like polymerization in order to reduce the damage of ultraviolet light. The ...bifunctional microcapsules (MPCMs/TiO2) consist of n-octadecane as core material and poly (methyl-methacrylate) (PMMA) doped with titanium dioxide nanoparticles as shell material. The scanning electronic microscope (SEM) micrographs and particle size distributions showed that the as-prepared microcapsules are spherical and about 10–20µm in average diameter. It was confirmed by Fourier transformation infrared spectroscope (FTIR) and energy dispersive spectrometer (EDS) spectra that modified TiO2 nanoparticles had been well fixed in the cross-linked network structure of PMMA shell. In addition, the results of differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and ultraviolet visible spectrophotometer (UV–vis) measurements demonstrated that the microcapsules exhibited high thermal storage capability, good thermal reliability and stability, and good UV-shielding property. The resultant samples of MPCMs/TiO2 may become the potential materials in the advanced applications of intelligent textile.
•Microencapsulated PCMs were prepared by suspension-like polymerization.•Modified TiO2 nanoparticles as inorganic UV absorber were doped into PMMA shell.•The microcapsules had two functions of thermal energy storage and UV-shielding.•The microcapsules performed well in thermal storage, stability and UV-shielding.
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•A new type of microPCMs with an additional function of thermochromic performance was synthesized.•Provide a feasible approach for endowing microPCMs an additional function.•The ...microcapsules present dual functions of thermochromic and latent-heat storage feature.•The microcapsules achieved a good thermal stability and high thermal storage capability.
In this study, a new type of microencapsulated phase change materials (microPCMs) with an additional function of thermochromic performance was designed and synthesized successfully. Thermochromatic pigments were firstly assembled on the interface of n-octadecane droplets in oil/water emulsion. And then a thermochromic pigment/PMMA shell was fabricated through suspension-like polymerization. The microstructures and chemical compositions of the resultant microcapsules were investigated by scanning electronic microscope (SEM) and Fourier transformation infrared spectroscope (FT-IR). SEM images display that these microcapsules presented a spherical shape and well-defined core-shell structure. According to DSC and TGA examinations, these dual functionalized microPCMs exhibited excellent thermal energy storage-release performance, high thermal storage capability (higher than 97%), and good thermal stability. In addition, these microPCMs successfully achieved thermochromic function as their temperature exceeded the target temperature. The dual functionalized microcapsules developed in this work showed great potential in applications for solar energy storage, thermo-sensors, food and medicine package and intelligent textiles or fabrics, etc.
•A new high thermal conductivity phase change materials.•Experimental study of strengthening thermal conductivity of phase change materials.•Theoretical analyses of thermal conductivity and ...crystallization.•Increased latent heat of phase change materials.
In this study, nano-Si3N4 was employed to enhance thermal performance of phase change materials (PCMs), and a new formula was proposed to explain the relationship between the thermal conductivity and the latent heat. Ultrasonically stirred, the composite PCMs were prepared at 80°C with different additional rate (1, 2, 3, 4, 5, 10wt%). The experimental results showed that the thermal conductivity of composite PCMs increased with the increasing Si3N4 loading contents, and the thermal conductivity increased by 35% while the thermal diffusivity increased by 47% at 10wt% Si3N4 additional fraction. Additionally, there was an interesting phenomenon. The latent heat of the composite PCMs at 1wt% addition rate was 3.4% higher than that of paraffin, that has been rarely reported in articles. An explanation was provided from crystallography and thermodynamic. A calculation method was also performed with relative errors in the range of 5.68%.
Thermal behavior is one of the most important properties for phase change microcapsules in solar energy storage. Here, a new type of phase change microcapsules was synthesized based on n-octadecane ...core and polymethylmethacrylate shell supplemented with modified silicon nitride powders, aiming to achieve improvement of thermal property in the phase change materials. SEM micrographs showed that the as-prepared microcapsules have a regular spherical shape with a well-defined core-shell structure. FTIR curves and EDS spectrogram demonstrated that silicon nitride can be well cross-linked with microcapsules after surface modification. In addition, TGA, forward looking infra-red system and DSC (before and after 500 heating and cooling cycles) analyses were performed to investigate the thermal property of the as-prepared microcapsules. The results indicated that the microcapsules have high thermal storage capability, enhanced thermal reliability and stability, and increased thermal conductivity. Especially, the thermal conductivity of microcapsules is enhanced by 56.8% compared with that of the microcapsules without the addition of silicon nitride.
•A new high thermal conductivity microcapsules were synthesized.•Thermal behavior was detected by Forward Looking Infra-red System.•Thermal conductivity is enhanced by 58%.•Silicon nitride is more economically preferred in promoting the thermal conductivity of phase change materials.
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