Background: Hydrogen-rich saline(HRS) has antioxidative, anti-inflammatory and anti-apoptotic properties. We investigated the effects of hydrogen on hepatic ischemia-reperfusion(I/R) and laparoscopic hepatectomy in sw...Background: Hydrogen-rich saline(HRS) has antioxidative, anti-inflammatory and anti-apoptotic properties. We investigated the effects of hydrogen on hepatic ischemia-reperfusion(I/R) and laparoscopic hepatectomy in swine. Methods: Twenty-one healthy Bama miniature pigs were randomly divided into the sham group, ischemia-reperfusion injury(IRI) group, HRS-5(5 m L/kg) group, and HRS-10(10 m L/kg) group. HRS was injected through the portal vein 10 min before reperfusion and at postoperative day 1, 2 and 3. The roles of HRS on oxidative stress, inflammatory response and liver regeneration were studied. Results: Compared with the IRI group, HRS treatment attenuated oxidative stress by increasing catalase activity and reducing myeloperoxidase. White blood cells in the HRS-10 group were reduced compared with the IRI group( P < 0.01). In the HRS-10 group, interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha, C-reactive protein and cortisol were downregulated, whereas interleukin-10 was upregulated. In addition, HRS attenuated endothelial cell injury and promoted the secretion of angiogenic cytokines, including vascular endothelial growth factor, angiopoietin-1 and angiopoietin-2. HRS elevated the levels of hepatocyte growth factor, Cyclin D1, proliferating cell nuclear antigen, Ki-67 and reduced the secretion of transforming growth factor-beta. Conclusions: HRS treatment may exert a protective effect against I/R and hepatectomy-induced hepatic damage by reducing oxidative stress, suppressing the inflammatory response and promoting liver regeneration.展开更多
In order to research the effect of microalloying Nb,the microstructure and heat treatment distortion of case carburizing steels with and without Nb addition are compared.Results show that a uniform and fine prior aust...In order to research the effect of microalloying Nb,the microstructure and heat treatment distortion of case carburizing steels with and without Nb addition are compared.Results show that a uniform and fine prior austenite grain size was obtained for the steel with the addition of 0.03 wt.%Nb even after being carburized at 980℃for 37 h,resulting in a very deep hardened layer of about 4 mm.Nb is an effective microalloying element to hinder austenite grain growth of gears during high-temperature carburizing.Theoretical calculation and experimental observation of NbC precipitates indicate that fine NbC precipitates have not evidently dissolved at 980℃,and thus they can act as grain refiners due to pinning effect.Heat treatment distortion of Nb-added steel is much lower than that of the steel without Nb addition.It may be contributed to its fine and uniform grain size,which presumably influences stress during martensitic transformation.展开更多
基金supported by grants from the National Natural Science Foundation of China(31472245 and 31772807)
文摘Background: Hydrogen-rich saline(HRS) has antioxidative, anti-inflammatory and anti-apoptotic properties. We investigated the effects of hydrogen on hepatic ischemia-reperfusion(I/R) and laparoscopic hepatectomy in swine. Methods: Twenty-one healthy Bama miniature pigs were randomly divided into the sham group, ischemia-reperfusion injury(IRI) group, HRS-5(5 m L/kg) group, and HRS-10(10 m L/kg) group. HRS was injected through the portal vein 10 min before reperfusion and at postoperative day 1, 2 and 3. The roles of HRS on oxidative stress, inflammatory response and liver regeneration were studied. Results: Compared with the IRI group, HRS treatment attenuated oxidative stress by increasing catalase activity and reducing myeloperoxidase. White blood cells in the HRS-10 group were reduced compared with the IRI group( P < 0.01). In the HRS-10 group, interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha, C-reactive protein and cortisol were downregulated, whereas interleukin-10 was upregulated. In addition, HRS attenuated endothelial cell injury and promoted the secretion of angiogenic cytokines, including vascular endothelial growth factor, angiopoietin-1 and angiopoietin-2. HRS elevated the levels of hepatocyte growth factor, Cyclin D1, proliferating cell nuclear antigen, Ki-67 and reduced the secretion of transforming growth factor-beta. Conclusions: HRS treatment may exert a protective effect against I/R and hepatectomy-induced hepatic damage by reducing oxidative stress, suppressing the inflammatory response and promoting liver regeneration.
基金the Ministry of Science and Technology(MOST)of China under the contract of No.2016YFB0300102The financial support from CITIC Metals is also acknowledged.
文摘In order to research the effect of microalloying Nb,the microstructure and heat treatment distortion of case carburizing steels with and without Nb addition are compared.Results show that a uniform and fine prior austenite grain size was obtained for the steel with the addition of 0.03 wt.%Nb even after being carburized at 980℃for 37 h,resulting in a very deep hardened layer of about 4 mm.Nb is an effective microalloying element to hinder austenite grain growth of gears during high-temperature carburizing.Theoretical calculation and experimental observation of NbC precipitates indicate that fine NbC precipitates have not evidently dissolved at 980℃,and thus they can act as grain refiners due to pinning effect.Heat treatment distortion of Nb-added steel is much lower than that of the steel without Nb addition.It may be contributed to its fine and uniform grain size,which presumably influences stress during martensitic transformation.
