BACKGROUND Unconjugated bilirubin(UCB) is generally considered toxic but has gained recent prominence for its anti-inflammatory properties. However, the effects of it on the interaction between intestinal flora and or...BACKGROUND Unconjugated bilirubin(UCB) is generally considered toxic but has gained recent prominence for its anti-inflammatory properties. However, the effects of it on the interaction between intestinal flora and organisms and how it influences immune responses remain unresolved.AIM To investigate the role of UCB in intestinal barrier function and immune inflammation in mice with dextran-sulfate-sodium-induced colitis.METHODS Acute colitis was induced by 3%(w/v) dextran sulfate sodium salt in drinking water for 6 d followed by untreated water for 2 d. Concurrently, mice with colitis were administered 0.2 mL UCB(400 μmol/L) by intra-gastric gavage for 7 d.Disease activity index(DAI) was monitored daily. Mice were sacrificed at the end of the experiment. The length of the colon and weight of the spleen were recorded. Serum level of D-lactate, intestinal digestive proteases activity, and changes to the gut flora were analyzed. In addition, colonic specimens were analyzed by histology and for expression of inflammatory markers and proteins.RESULTS Mice treated with UCB had significantly relieved severity of colitis, including lower DAI, longer colon length, and lower spleen weight(colon length: 4.92 ±0.09 cm vs 3.9 ± 0.15 cm; spleen weight: 0.33 ± 0.04 vs 0.74 ± 0.04, P < 0.001). UCB administration inactivated digestive proteases(chymotrypsin: 18.70 ± 0.69 U/g vs44.81 ± 8.60 U/g; trypsin: 1.52 ± 0.23 U/g vs 9.05 ± 1.77 U/g, P < 0.01), increased expression of tight junction(0.99 ± 0.05 vs 0.57 ± 0.03, P < 0.001), decreased serum level of D-lactate(31.76 ± 3.37 μmol/L vs 54.25 ± 1.45 μmol/L, P < 0.001), and lowered histopathological score(4 ± 0.57 vs 7 ± 0.57, P < 0.001) and activity of myeloperoxidase(46.79 ± 2.57 U/g vs 110.32 ± 19.19 U/g, P < 0.001). UCB also regulated the intestinal microbiota, inhibited expression of tumor necrosis factor(TNF) α and interleukin 1β(TNF-α: 52.61 ± 7.81 pg/mg vs 105.04 ± 11.92 pg/mg,interleukin 1β: 13.43 ± 1.68 vs 32.41 ± 4.62 pg/mg, P < 0.001), decreased展开更多
The pre-separation of silica and alumina in aluminosilicates is of great significance for efficiently treating alumina-/ silica-bearing minerals for alumina production. In this work, the reaction behavior of kaolinite...The pre-separation of silica and alumina in aluminosilicates is of great significance for efficiently treating alumina-/ silica-bearing minerals for alumina production. In this work, the reaction behavior of kaolinite with ferric oxide during reduction roasting was investigated. The results of thermodynamic analyses and reduction roasting experiments show that ferrous oxide obtained from ferric oxide reduction preferentially reacts with alumina in kaolinite to form hercynite, meanwhile the silica in kaolinite is transformed into quartz solid solution and/or cristobalite solid solution. With increasing roasting temperature, fayalite formed by reaction of surplus ferrous oxide with silica at low temperature is reduced to silica and metallic iron in the presence of sufficient carbon dosage. However, increasing roasting temperature and decreasing Fe2O3/Al2O3 molar ratio favor mullite formation. The complete conversion of kaolinte into free silica and hercynite can be obtained by roasting raw meal of kaolin, ferric oxide and coal powder with Fe2O3/Al2O3/C molar ratio of 1.2:2.0:1.2 at 1373 K for 60 min. This work may facilitate the development of a technique for comprehensively utilizing silica and alumina in aluminosilicates.展开更多
Alkali leaching was employed to investigate the separation of alumina and silica in roasted kaolin obtained by roasting kaolin alone in air at 1273 K for 60 min and in clinker prepared by roasting the mixed raw meal o...Alkali leaching was employed to investigate the separation of alumina and silica in roasted kaolin obtained by roasting kaolin alone in air at 1273 K for 60 min and in clinker prepared by roasting the mixed raw meal of kaolin,ferric oxide and coal powder with Fe2O3/Al2O3/C molar ratio of 1.2:2.0:1.2 in reducing atmosphere at 1373 K for 60 min.The thermodynamic analyses and alkali leaching results show that the composition of the Al-Si spinel in roasted kaolin is close to that of 3Al2O3·2SiO2 and the spinel is dissolved with increasing leaching time,resulting in difficulty in deeply separating alumina and silica in kaolin by the traditional roasting-leaching process.On the contrary,the efficient separation of alumina and silica in kaolin can be reached by fully converting kaolinite into insoluble hercynite and soluble free silica,namely quartz solid solution and cristobalite solid solution,during reduction roasting,followed by alkali leaching of the obtained clinker.Furthermore,experimental results from treating high-silica diasporic bauxite indicate that the reduction roasting-alkali leaching process is potential to separate silica and alumina in aluminosilicates.展开更多
基金Supported by grants from the National Natural Foundation of China,No.81703232
文摘BACKGROUND Unconjugated bilirubin(UCB) is generally considered toxic but has gained recent prominence for its anti-inflammatory properties. However, the effects of it on the interaction between intestinal flora and organisms and how it influences immune responses remain unresolved.AIM To investigate the role of UCB in intestinal barrier function and immune inflammation in mice with dextran-sulfate-sodium-induced colitis.METHODS Acute colitis was induced by 3%(w/v) dextran sulfate sodium salt in drinking water for 6 d followed by untreated water for 2 d. Concurrently, mice with colitis were administered 0.2 mL UCB(400 μmol/L) by intra-gastric gavage for 7 d.Disease activity index(DAI) was monitored daily. Mice were sacrificed at the end of the experiment. The length of the colon and weight of the spleen were recorded. Serum level of D-lactate, intestinal digestive proteases activity, and changes to the gut flora were analyzed. In addition, colonic specimens were analyzed by histology and for expression of inflammatory markers and proteins.RESULTS Mice treated with UCB had significantly relieved severity of colitis, including lower DAI, longer colon length, and lower spleen weight(colon length: 4.92 ±0.09 cm vs 3.9 ± 0.15 cm; spleen weight: 0.33 ± 0.04 vs 0.74 ± 0.04, P < 0.001). UCB administration inactivated digestive proteases(chymotrypsin: 18.70 ± 0.69 U/g vs44.81 ± 8.60 U/g; trypsin: 1.52 ± 0.23 U/g vs 9.05 ± 1.77 U/g, P < 0.01), increased expression of tight junction(0.99 ± 0.05 vs 0.57 ± 0.03, P < 0.001), decreased serum level of D-lactate(31.76 ± 3.37 μmol/L vs 54.25 ± 1.45 μmol/L, P < 0.001), and lowered histopathological score(4 ± 0.57 vs 7 ± 0.57, P < 0.001) and activity of myeloperoxidase(46.79 ± 2.57 U/g vs 110.32 ± 19.19 U/g, P < 0.001). UCB also regulated the intestinal microbiota, inhibited expression of tumor necrosis factor(TNF) α and interleukin 1β(TNF-α: 52.61 ± 7.81 pg/mg vs 105.04 ± 11.92 pg/mg,interleukin 1β: 13.43 ± 1.68 vs 32.41 ± 4.62 pg/mg, P < 0.001), decreased
基金Project(51604309)supported by the National Natural Science Foundation of China
文摘The pre-separation of silica and alumina in aluminosilicates is of great significance for efficiently treating alumina-/ silica-bearing minerals for alumina production. In this work, the reaction behavior of kaolinite with ferric oxide during reduction roasting was investigated. The results of thermodynamic analyses and reduction roasting experiments show that ferrous oxide obtained from ferric oxide reduction preferentially reacts with alumina in kaolinite to form hercynite, meanwhile the silica in kaolinite is transformed into quartz solid solution and/or cristobalite solid solution. With increasing roasting temperature, fayalite formed by reaction of surplus ferrous oxide with silica at low temperature is reduced to silica and metallic iron in the presence of sufficient carbon dosage. However, increasing roasting temperature and decreasing Fe2O3/Al2O3 molar ratio favor mullite formation. The complete conversion of kaolinte into free silica and hercynite can be obtained by roasting raw meal of kaolin, ferric oxide and coal powder with Fe2O3/Al2O3/C molar ratio of 1.2:2.0:1.2 at 1373 K for 60 min. This work may facilitate the development of a technique for comprehensively utilizing silica and alumina in aluminosilicates.
基金Project(51604309) supported by the National Natural Science Foundation of China
文摘Alkali leaching was employed to investigate the separation of alumina and silica in roasted kaolin obtained by roasting kaolin alone in air at 1273 K for 60 min and in clinker prepared by roasting the mixed raw meal of kaolin,ferric oxide and coal powder with Fe2O3/Al2O3/C molar ratio of 1.2:2.0:1.2 in reducing atmosphere at 1373 K for 60 min.The thermodynamic analyses and alkali leaching results show that the composition of the Al-Si spinel in roasted kaolin is close to that of 3Al2O3·2SiO2 and the spinel is dissolved with increasing leaching time,resulting in difficulty in deeply separating alumina and silica in kaolin by the traditional roasting-leaching process.On the contrary,the efficient separation of alumina and silica in kaolin can be reached by fully converting kaolinite into insoluble hercynite and soluble free silica,namely quartz solid solution and cristobalite solid solution,during reduction roasting,followed by alkali leaching of the obtained clinker.Furthermore,experimental results from treating high-silica diasporic bauxite indicate that the reduction roasting-alkali leaching process is potential to separate silica and alumina in aluminosilicates.
