为比较磁控溅射制备的a-C:BCx和a-C:Cr这2种涂层的摩擦学性能,并研究2种涂层结构对摩擦学性能的影响,采用非平衡磁控溅射技术在38Cr Mo Al齿轮钢表面制备了a-C:BCx和a-C:Cr涂层,通过扫描电子显微镜与纳米压痕仪对2种涂层显微结构与力学...为比较磁控溅射制备的a-C:BCx和a-C:Cr这2种涂层的摩擦学性能,并研究2种涂层结构对摩擦学性能的影响,采用非平衡磁控溅射技术在38Cr Mo Al齿轮钢表面制备了a-C:BCx和a-C:Cr涂层,通过扫描电子显微镜与纳米压痕仪对2种涂层显微结构与力学性能进行了表征,并利用摩擦磨损试验机对涂层在干摩擦和油润滑(4109润滑油)条件下的摩擦学性能进行了评价。结果表明:a-C:BCx涂层的显微硬度和弹性模量均高于a-C:Cr涂层,a-C:BCx涂层在常温干摩擦、常温油润滑和高温油润滑下的摩擦学性能均优于a-C:Cr涂层,这主要归因于a-C:BCx涂层具有较高的显微硬度以及在对偶球上形成稳定的转移膜。展开更多
Background:β-cryptoxanthin(BCX),one of the major carotenoids detected in human circulation,can protect against the development of fatty liver disease.BCX can be metabolized throughβ-carotene-15,15'-oxygenase(BCO...Background:β-cryptoxanthin(BCX),one of the major carotenoids detected in human circulation,can protect against the development of fatty liver disease.BCX can be metabolized throughβ-carotene-15,15'-oxygenase(BCO1)andβ-carotene-9',10'-oxygenase(BCO2)cleavage pathways to produce both vitamin A and apo-carotenoids,respectively,which are considered important signaling molecules in a variety of biological processes.Recently,we have demonstrated that BCX treatment reduced hepatic steatosis severity and hepatic total cholesterol levels in both wide type and BCO1^(-/-)/BCO2^(-/-)double knock out(KO)mice.Whether the protective effect of BCX is seen in single BCO2^(-/-)KO mice is unclear.Methods:In the present study,male BCO2^(-/-)KO mice at 1 and 5 months of age were assigned to two groups by age and weight-matching as follows:(I)-BCX control diet alone(AIN-93 purified diets);(II)+BCX 10 mg(supplemented with 10 mg of BCX/kg of diet)for 3 months.At 4 and 8 months of age,hepatic steatosis and inflammatory foci were evaluated by histopathology.Retinoids and BCX concentrations in liver tissue were analyzed by high-performance liquid chromatography(HPLC).Hepatic protein expressions of SIRT1,acetylated and total FoxO1,PGC1α,and PPARαwere determined by the Western blot analysis.Real-time PCR for gene expressions(MCAD,SCD1,FAS,TNFα,and IL-1βgene expression relative toβ-actin)was conducted in the liver.Results:Steatosis was detected at 8 months but not at 4 months of age.Moreover,BCX supplementation significantly reduced the severity of steatosis in the livers of BCO2KO mice,which was associated with changes in hepatic SIRT1 acetylation of FOXO1,PGC1αprotein expression and PPARαprotein expression in BCO2^(-/-)KO mice.HPLC analysis showed that hepatic BCX was detected in BCX supplemented groups,but there were no differences in the hepatic levels of retinol and retinyl palmitate(RP)among all groups.Conclusions:The present study provided experimental evidence that BCX intervention can reduce liver steatosis independent of BCO2.展开更多
文摘为比较磁控溅射制备的a-C:BCx和a-C:Cr这2种涂层的摩擦学性能,并研究2种涂层结构对摩擦学性能的影响,采用非平衡磁控溅射技术在38Cr Mo Al齿轮钢表面制备了a-C:BCx和a-C:Cr涂层,通过扫描电子显微镜与纳米压痕仪对2种涂层显微结构与力学性能进行了表征,并利用摩擦磨损试验机对涂层在干摩擦和油润滑(4109润滑油)条件下的摩擦学性能进行了评价。结果表明:a-C:BCx涂层的显微硬度和弹性模量均高于a-C:Cr涂层,a-C:BCx涂层在常温干摩擦、常温油润滑和高温油润滑下的摩擦学性能均优于a-C:Cr涂层,这主要归因于a-C:BCx涂层具有较高的显微硬度以及在对偶球上形成稳定的转移膜。
基金supported by grants from NIFA/AFRI(2017-67017-26363)USDA/ARS(58-1950-0074S).
文摘Background:β-cryptoxanthin(BCX),one of the major carotenoids detected in human circulation,can protect against the development of fatty liver disease.BCX can be metabolized throughβ-carotene-15,15'-oxygenase(BCO1)andβ-carotene-9',10'-oxygenase(BCO2)cleavage pathways to produce both vitamin A and apo-carotenoids,respectively,which are considered important signaling molecules in a variety of biological processes.Recently,we have demonstrated that BCX treatment reduced hepatic steatosis severity and hepatic total cholesterol levels in both wide type and BCO1^(-/-)/BCO2^(-/-)double knock out(KO)mice.Whether the protective effect of BCX is seen in single BCO2^(-/-)KO mice is unclear.Methods:In the present study,male BCO2^(-/-)KO mice at 1 and 5 months of age were assigned to two groups by age and weight-matching as follows:(I)-BCX control diet alone(AIN-93 purified diets);(II)+BCX 10 mg(supplemented with 10 mg of BCX/kg of diet)for 3 months.At 4 and 8 months of age,hepatic steatosis and inflammatory foci were evaluated by histopathology.Retinoids and BCX concentrations in liver tissue were analyzed by high-performance liquid chromatography(HPLC).Hepatic protein expressions of SIRT1,acetylated and total FoxO1,PGC1α,and PPARαwere determined by the Western blot analysis.Real-time PCR for gene expressions(MCAD,SCD1,FAS,TNFα,and IL-1βgene expression relative toβ-actin)was conducted in the liver.Results:Steatosis was detected at 8 months but not at 4 months of age.Moreover,BCX supplementation significantly reduced the severity of steatosis in the livers of BCO2KO mice,which was associated with changes in hepatic SIRT1 acetylation of FOXO1,PGC1αprotein expression and PPARαprotein expression in BCO2^(-/-)KO mice.HPLC analysis showed that hepatic BCX was detected in BCX supplemented groups,but there were no differences in the hepatic levels of retinol and retinyl palmitate(RP)among all groups.Conclusions:The present study provided experimental evidence that BCX intervention can reduce liver steatosis independent of BCO2.
