Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of whic...Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of which viscosity sharply increases when temperature is lowered than temperature of critical viscosity(TCV).The fluctuation in temperature near the TCVcan cause an accumulation of slag inside the gasifier.In order to prevent slag blockage,it is necessary to adjust the ash composition by additive to modify the flow property of coal rich in calcium and iron.Main components of coal gangue are Al_(2)O_(3) and SiO_(2),which is a potential additive to modify the ash flow properties of these coals.In this work,we investigated the ash flow properties of a typical coal rich in calcium and iron by adding coal gangue with different SiO_(2)/Al_(2)O_(3)ratio.The results showed that the ash fusion temperatures(AFTs)firstly decreased,and then increased with increasing amount of coal gangue addition.Chemical composition of coal ash rich in calcium and iron moved from gehlenite primary phase to anorthite,quartz and corundum primary phases.The slags with coal gangue addition behaved as a glassy slag,of which the viscosity gradually increased as temperature decreased.Besides,a high SiO_(2)/Al_(2)O_(3)ratio of coal gangue was beneficial to modify the slag viscosity behavior.Addition of coal gangue with a high SiO_(2)/Al_(2)O_(3)ratio impeded formation of crystalline phases during cooling.This work demonstrated that coal gangue addition was an effective way to improve the ash flow properties of the coal rich in calcium and iron for the entrained flow gasifier.展开更多
AIM: To determine the method of growing small intestinal epithelial cells in short-term primary culture and to investigate the effect of extracellular iron concentration ([Fe3+]) on calcium absorption and the relation...AIM: To determine the method of growing small intestinal epithelial cells in short-term primary culture and to investigate the effect of extracellular iron concentration ([Fe3+]) on calcium absorption and the relationship between the rising intracellular calcium concentration ([Ca2+]i) and cell apoptosis in human intestinal epithelial Caco-2 cells. METHODS: Primary culture was used for growing small intestinal epithelial cells. [Ca2+]i was detected by a confocal laser scanning microscope. The changes in [Ca2+]i were represented by fluorescence intensity (FI). The apoptosis was evaluated by flow cytometry. RESULTS: Isolation of epithelial cells and preservation of its three-dimensional integrity were achieved using the digestion technique of a mixture of collagenase Ⅺ and dispase Ⅰ. Purification of the epithelial cells was facilitated by using a simple differential sedimentation method. The results showed that proliferation of normal gut epithelium in vitro was initially dependent upon the maintenance of structural integrity of the tissue. If 0.25% trypsin was used for digestion, the cells were severely damaged and very difficult to stick to the Petri dish for growing. The Fe3+ chelating agent desferrioxamine (100, 200 and 300 μmol/L) increased the FI of Caco-2 cells from 27.50±13.18 (control, n = 150) to 35.71±13.99 (n = 150, P<0.01), 72.19±35.40 (n = 150, P<0.01) and 211.34±29.03 (n = 150,P<0.01) in a concentration-dependent manner. There was a significant decrease in the FI of Caco-2 cells treated by ferric ammonium citrate (FAC, a Fe3+ donor; 10, 50 and 100 μmol/L). The FI value of Caco-2 cells treated by FAC was 185.85±33.77 (n = 150, P<0.01), 122.73±58.47 (n = 150, P<0.01), and 53.29±19.82 (n= 150,P<0.01), respectively, suggesting that calcium absorption was influenced by [Fe3+]. Calcium ionophore A23187(0.1,1.0 and 10 μmol/L) increased the FI of Caco-2 cells from 40.45±13.95 (control, n = 150) to 45.19±21.95 (n = 150, P<0.01), 89.87±43.29 (n = 150, P<0.01) and 104.64±51.07 (n = 150,P<0.01) in a concentration-dependent manner. The positive apoptotic cell number of the Caco-2 cells after being treated with A23187 increased from 0.32% to 0.69%, 0.90% and 1.10%, indicating that the increase in the positive apoptotic cell number was positively correlated with [Ca2+]i. CONCLUSION: Ca2+ absorbability is increased with the decrease of extracellular iron concentration Fe3+ and hindered with the increase of Fe3+ consistence out of them. Furthermore, increase of [Ca2+]i can induce apoptosis in Caco-2 cells.展开更多
Background and objective The expression of various trace elements and markers in lung cancer is controversial.The aim of this study is to evaluate the presence of calcium(Ca),copper(Cu),iron(Fe) and carcinoembryonic a...Background and objective The expression of various trace elements and markers in lung cancer is controversial.The aim of this study is to evaluate the presence of calcium(Ca),copper(Cu),iron(Fe) and carcinoembryonic antigen(CEA) in cancerous untreated lung tissues and to determine a possible association between these markers and lung cancer.Methods Fourty-eight cancerous lung tissue blocks,from Sultan Qaboos University Hospital,Sultanate of Oman,were studied.Fe,Ca,Cu,and CEA were demonstrated in the tissue blocks using Perl's Prussian blue,Von Kossa's,modified rhodanine and immunohistochemical staining methods,respectively.Results Twenty-three of 48 specimens showed positive Fe staining,2 showed positive Ca staining and Cu was absent in all specimens.93.7% expressed CEA in varying degree of positivity.81.25% of these sections showed high expression of CEA.Conclusion Tissue concentrations of trace elements were not elevated in lung cancer and therefore cannot be considered as a potential marker.Despite the low sensitivity and specificity of CEA as previously reported,tissue CEA should be considered as a potential marker in the evaluation of lung cancer.展开更多
The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace by using vapor pressure method.A sealed Mo reaction chamber and a self-made CaO crucible were use...The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace by using vapor pressure method.A sealed Mo reaction chamber and a self-made CaO crucible were used in this experiment.The thermodynamic parameters obtained are as follows for reaction Ca(g) =[Ca]\nK = 4.27-15040/T△G^0 = 125000-35.5T J/mol The relation between dissolved amount of calcium in liquid iron(1873K) and calcium vapor pressure is expressed as[%Ca]= 0.028 pc.展开更多
Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overl...Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overload cardiomyopathy,a condition which provokes mortality due to heart failure in iron-overloaded patients.Currently,the mechanism of iron uptake into cardiomyocytes is still not clearly understood.Growing evidence suggests L-type Ca2+channels(LTCCs)as a possible pathway for ferrous iron(Fe2+)uptake into cardiomyocytes under iron overload conditions.Nevertheless,controversy still exists since some findings on pharmacological interventions and those using different cell types do not support LTCC’s role as a portal for iron uptake in cardiac cells.Recently,T-type Ca2+channels (TTCC)have been shown to play an important role in the diseased heart.Although TTCC and iron uptake in cardiomyocytes has not been investigated greatly,a recent finding indicated that TTCC could be an important portal in thalassemic hearts.In this review,comprehensive findings collected from previous studies as well as a discussion of the controversy regarding iron uptake mechanisms into cardiomyocytes via calcium channels are presented with the hope that understanding the cellular iron uptake mechanism in cardiomyocytes will lead to improved treatment and prevention strategies,particularly in iron-overloaded patients.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(2017CXNL04)。
文摘Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of which viscosity sharply increases when temperature is lowered than temperature of critical viscosity(TCV).The fluctuation in temperature near the TCVcan cause an accumulation of slag inside the gasifier.In order to prevent slag blockage,it is necessary to adjust the ash composition by additive to modify the flow property of coal rich in calcium and iron.Main components of coal gangue are Al_(2)O_(3) and SiO_(2),which is a potential additive to modify the ash flow properties of these coals.In this work,we investigated the ash flow properties of a typical coal rich in calcium and iron by adding coal gangue with different SiO_(2)/Al_(2)O_(3)ratio.The results showed that the ash fusion temperatures(AFTs)firstly decreased,and then increased with increasing amount of coal gangue addition.Chemical composition of coal ash rich in calcium and iron moved from gehlenite primary phase to anorthite,quartz and corundum primary phases.The slags with coal gangue addition behaved as a glassy slag,of which the viscosity gradually increased as temperature decreased.Besides,a high SiO_(2)/Al_(2)O_(3)ratio of coal gangue was beneficial to modify the slag viscosity behavior.Addition of coal gangue with a high SiO_(2)/Al_(2)O_(3)ratio impeded formation of crystalline phases during cooling.This work demonstrated that coal gangue addition was an effective way to improve the ash flow properties of the coal rich in calcium and iron for the entrained flow gasifier.
基金Supported by the Natural Science Foundation of Hebei Province,No. 303158 Education Department Foundation of Hebei Province,No. 2002136
文摘AIM: To determine the method of growing small intestinal epithelial cells in short-term primary culture and to investigate the effect of extracellular iron concentration ([Fe3+]) on calcium absorption and the relationship between the rising intracellular calcium concentration ([Ca2+]i) and cell apoptosis in human intestinal epithelial Caco-2 cells. METHODS: Primary culture was used for growing small intestinal epithelial cells. [Ca2+]i was detected by a confocal laser scanning microscope. The changes in [Ca2+]i were represented by fluorescence intensity (FI). The apoptosis was evaluated by flow cytometry. RESULTS: Isolation of epithelial cells and preservation of its three-dimensional integrity were achieved using the digestion technique of a mixture of collagenase Ⅺ and dispase Ⅰ. Purification of the epithelial cells was facilitated by using a simple differential sedimentation method. The results showed that proliferation of normal gut epithelium in vitro was initially dependent upon the maintenance of structural integrity of the tissue. If 0.25% trypsin was used for digestion, the cells were severely damaged and very difficult to stick to the Petri dish for growing. The Fe3+ chelating agent desferrioxamine (100, 200 and 300 μmol/L) increased the FI of Caco-2 cells from 27.50±13.18 (control, n = 150) to 35.71±13.99 (n = 150, P<0.01), 72.19±35.40 (n = 150, P<0.01) and 211.34±29.03 (n = 150,P<0.01) in a concentration-dependent manner. There was a significant decrease in the FI of Caco-2 cells treated by ferric ammonium citrate (FAC, a Fe3+ donor; 10, 50 and 100 μmol/L). The FI value of Caco-2 cells treated by FAC was 185.85±33.77 (n = 150, P<0.01), 122.73±58.47 (n = 150, P<0.01), and 53.29±19.82 (n= 150,P<0.01), respectively, suggesting that calcium absorption was influenced by [Fe3+]. Calcium ionophore A23187(0.1,1.0 and 10 μmol/L) increased the FI of Caco-2 cells from 40.45±13.95 (control, n = 150) to 45.19±21.95 (n = 150, P<0.01), 89.87±43.29 (n = 150, P<0.01) and 104.64±51.07 (n = 150,P<0.01) in a concentration-dependent manner. The positive apoptotic cell number of the Caco-2 cells after being treated with A23187 increased from 0.32% to 0.69%, 0.90% and 1.10%, indicating that the increase in the positive apoptotic cell number was positively correlated with [Ca2+]i. CONCLUSION: Ca2+ absorbability is increased with the decrease of extracellular iron concentration Fe3+ and hindered with the increase of Fe3+ consistence out of them. Furthermore, increase of [Ca2+]i can induce apoptosis in Caco-2 cells.
文摘Background and objective The expression of various trace elements and markers in lung cancer is controversial.The aim of this study is to evaluate the presence of calcium(Ca),copper(Cu),iron(Fe) and carcinoembryonic antigen(CEA) in cancerous untreated lung tissues and to determine a possible association between these markers and lung cancer.Methods Fourty-eight cancerous lung tissue blocks,from Sultan Qaboos University Hospital,Sultanate of Oman,were studied.Fe,Ca,Cu,and CEA were demonstrated in the tissue blocks using Perl's Prussian blue,Von Kossa's,modified rhodanine and immunohistochemical staining methods,respectively.Results Twenty-three of 48 specimens showed positive Fe staining,2 showed positive Ca staining and Cu was absent in all specimens.93.7% expressed CEA in varying degree of positivity.81.25% of these sections showed high expression of CEA.Conclusion Tissue concentrations of trace elements were not elevated in lung cancer and therefore cannot be considered as a potential marker.Despite the low sensitivity and specificity of CEA as previously reported,tissue CEA should be considered as a potential marker in the evaluation of lung cancer.
文摘The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace by using vapor pressure method.A sealed Mo reaction chamber and a self-made CaO crucible were used in this experiment.The thermodynamic parameters obtained are as follows for reaction Ca(g) =[Ca]\nK = 4.27-15040/T△G^0 = 125000-35.5T J/mol The relation between dissolved amount of calcium in liquid iron(1873K) and calcium vapor pressure is expressed as[%Ca]= 0.028 pc.
基金Supported by Thailand Research Fund grants RTA5280006 (Chattipakorn N)BRG5480003(Chattipakorn S)+1 种基金the National Research Council of Thailand(Chattipakorn N)the Thai-land Research Fund Royal Golden Jubilee project(Kumfu S and Chattipakorn N)
文摘Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overload cardiomyopathy,a condition which provokes mortality due to heart failure in iron-overloaded patients.Currently,the mechanism of iron uptake into cardiomyocytes is still not clearly understood.Growing evidence suggests L-type Ca2+channels(LTCCs)as a possible pathway for ferrous iron(Fe2+)uptake into cardiomyocytes under iron overload conditions.Nevertheless,controversy still exists since some findings on pharmacological interventions and those using different cell types do not support LTCC’s role as a portal for iron uptake in cardiac cells.Recently,T-type Ca2+channels (TTCC)have been shown to play an important role in the diseased heart.Although TTCC and iron uptake in cardiomyocytes has not been investigated greatly,a recent finding indicated that TTCC could be an important portal in thalassemic hearts.In this review,comprehensive findings collected from previous studies as well as a discussion of the controversy regarding iron uptake mechanisms into cardiomyocytes via calcium channels are presented with the hope that understanding the cellular iron uptake mechanism in cardiomyocytes will lead to improved treatment and prevention strategies,particularly in iron-overloaded patients.
