Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhi...Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.展开更多
In the heterogeneous reservoirs,CO_(2) flooding easily leads to CO_(2) gas channeling,which can seriously affect sweeping efficiency and reduce oil recovery.After thoroughly investigating the advantages and shortcomin...In the heterogeneous reservoirs,CO_(2) flooding easily leads to CO_(2) gas channeling,which can seriously affect sweeping efficiency and reduce oil recovery.After thoroughly investigating the advantages and shortcomings of various CO_(2) plugging technologies,this paper focuses on the feasibility of improving conventional water-alternating gas(WAG)through CO_(2)-responsive gel materials.Based on the different chemical reaction mechanisms between the unique chemical structure and CO_(2),changes in the material’s physical and chemical properties can respond to CO_(2).The feasibility of utilizing these property changes for CO_(2)-responsive plugging is explored.Various CO_(2)-responsive gels and gel nanoparticles have been extensively researched in different fields,such as energy,medicine,and biology.This paper surveys the molecular structures,chemical compositions,response mechanisms,and changes of these CO_(2)-responsive gels,aiming to draw insights into the carbon dioxide-enhanced oil recovery(CO_(2)-EOR)field.Finally,the key issues and future development direction of CO_(2)-responsive plugging gels were analyzed.展开更多
To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute a...To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.展开更多
The roles of intermediate conductance Ca2+-activated K+ channel (IKCal) in the pathogene- sis of hepatocellular carcinoma (HCC) were investigated. Immunohistochemistry and Western blotting were used to detect th...The roles of intermediate conductance Ca2+-activated K+ channel (IKCal) in the pathogene- sis of hepatocellular carcinoma (HCC) were investigated. Immunohistochemistry and Western blotting were used to detect the expression of IKCal protein in 50 HCC and 20 para-carcinoma tissue samples. Real-time PCR was used to detect the transcription level of IKCal mRNA in 13 HCC and 11 para-carcinoma tissue samples. The MTT assay was used to measure the function of IKCal in human HCC cell line HepG2 in vitro. TRAM-34, a specific blocker of IKCal, was used to intervene with the function of IKCal. As compared with para-carcinoma tissue, an over-expression of IKCal protein was detected in HCC tissue samples (P〈0.05). The mRNA expression level of IKCal in HCC tissues was 2.17 times higher than that in para-carcinoma tissues. The proliferation of HepG2 cells was suppressed by TRAM-34 (0.5, 1.0, 2.0 and 4.0 pxnol/L) in vitro (P〈0.05). Our results suggested that IKCal may play a role in the proliferation of human HCC, and IKCal blockers may represent a potential therapeutic strategy for HCC.展开更多
AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human...AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human liver cell line.METHODS:Net Ca 2+ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces,non-invasively.The expression levels of TRPC1 were increased by liposomal transfection,whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction. RESULTS:Ca 2+ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells.They were enhanced by addition of 20μmol/L noradrenalin and inhibited by 100μmol/L LaCl3(a non-selective Ca 2+ channel blocker);5μmol/L nifedipine did not induce any change.Overexpression of TRPC1 caused increased Ca 2+ influx.Five micromoles per liter nifedipine did not inhibit this elevation,whereas 100μmol/L LaCl3 did.CONCLUSION:In HL-7702 cells,there is a type of TRPC1-dependent Ca 2+ channel,which could be detected via NMT and inhibited by La3+.展开更多
Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were ...Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were incubated in ND96 (96 mmol/L NaCl, 2.0 mmol/L KCl, 1.8 mmol/L CaCl 2, 1.0 mmol/L MgCl 2, and 5.0 mmol/L HEPES, pH 7.4) at 4 ℃. Patch clamp recording (outside-out) were performed after 2-3 d. Isoflurane was administrated by the vaporizer driven by air, ethanol was applied by a closed, manual-controlled administration system. Different test potentials from 0 to 10 mV were given to observe changes of currents. Results: 0.7 mmol/L and 1.2 mmol/L of isoflurane could inhibit BK currents obviously at different command potentials, but 50 mmol/L, 100 mmol/L, or 200 mmol/L of ethanol had no any effect on BK currents. Conclusion: Clinical concentration of isoflurane can distinctly inhibit isolating BK currents.展开更多
The wound is induced by several mechanical and metabolic factors.In the etiology of the wound recovery,excessive oxidative stress,calcium ion(Ca^(2+))influx,and apoptosis have important roles.Ca^(2+)-permeable TRPM2 c...The wound is induced by several mechanical and metabolic factors.In the etiology of the wound recovery,excessive oxidative stress,calcium ion(Ca^(2+))influx,and apoptosis have important roles.Ca^(2+)-permeable TRPM2 channel is activated by oxidative stress.Protective roles of Hypericum perforatum extract(HP)on the mechanical nerve injury-induced apoptosis and oxidative toxicity through regulation of TRPM2 in the experimental animals were recently reported.The potential protective roles in HP treatment were evaluated on the TRPM2-mediated cellular oxidative toxicity in the renal epithelium(MPK)cells.The cells were divided into three groups as control,wound,and wound+HP treatment(75μM for 72 h).Wound diameters were more importantly decreased in the wound+HP group than in the wound group.In addition,the results of laser confocal microscopy analyses indicated protective roles of HP and TRPM2 antagonists(N-(p-Amylcinnamoyl)anthranilic acid and 2-aminoethyl diphenylborinate)against the wound-induced increase of Ca^(2+) influx and mitochondrial ROS production.The wound-induced increase of early(annexin V-FITC)apoptosis and late(propidium iodide)apoptosis were also decreased in the cells by the HP treatment.In conclusion,HP treatment acted protective effects against wound-mediated oxidative cell toxicity and apoptosis through TRPM2 inhibition.These effects may be attributed to their potent antioxidant effect.展开更多
基金the financial support from the National Key Research and Development Program of China(No.2018YFC1903403)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.
基金Supported by the Open Fund Project of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(YQZC202105)Yangtze University Student Innovation Program(Yz2022018).
文摘In the heterogeneous reservoirs,CO_(2) flooding easily leads to CO_(2) gas channeling,which can seriously affect sweeping efficiency and reduce oil recovery.After thoroughly investigating the advantages and shortcomings of various CO_(2) plugging technologies,this paper focuses on the feasibility of improving conventional water-alternating gas(WAG)through CO_(2)-responsive gel materials.Based on the different chemical reaction mechanisms between the unique chemical structure and CO_(2),changes in the material’s physical and chemical properties can respond to CO_(2).The feasibility of utilizing these property changes for CO_(2)-responsive plugging is explored.Various CO_(2)-responsive gels and gel nanoparticles have been extensively researched in different fields,such as energy,medicine,and biology.This paper surveys the molecular structures,chemical compositions,response mechanisms,and changes of these CO_(2)-responsive gels,aiming to draw insights into the carbon dioxide-enhanced oil recovery(CO_(2)-EOR)field.Finally,the key issues and future development direction of CO_(2)-responsive plugging gels were analyzed.
文摘To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.
基金supported by grants from the National Natural Science Foundation of China (No. 81072001)the Natural Science Foundation of Hubei Province, China (No.2011CDB556)
文摘The roles of intermediate conductance Ca2+-activated K+ channel (IKCal) in the pathogene- sis of hepatocellular carcinoma (HCC) were investigated. Immunohistochemistry and Western blotting were used to detect the expression of IKCal protein in 50 HCC and 20 para-carcinoma tissue samples. Real-time PCR was used to detect the transcription level of IKCal mRNA in 13 HCC and 11 para-carcinoma tissue samples. The MTT assay was used to measure the function of IKCal in human HCC cell line HepG2 in vitro. TRAM-34, a specific blocker of IKCal, was used to intervene with the function of IKCal. As compared with para-carcinoma tissue, an over-expression of IKCal protein was detected in HCC tissue samples (P〈0.05). The mRNA expression level of IKCal in HCC tissues was 2.17 times higher than that in para-carcinoma tissues. The proliferation of HepG2 cells was suppressed by TRAM-34 (0.5, 1.0, 2.0 and 4.0 pxnol/L) in vitro (P〈0.05). Our results suggested that IKCal may play a role in the proliferation of human HCC, and IKCal blockers may represent a potential therapeutic strategy for HCC.
基金Supported by The National Natural Science Foundation of China,No.30270532 and No.30670774Tsinghua-Yue-Yuen Medical Science Foundation,No.20240000531 and No.20240000547
文摘AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human liver cell line.METHODS:Net Ca 2+ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces,non-invasively.The expression levels of TRPC1 were increased by liposomal transfection,whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction. RESULTS:Ca 2+ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells.They were enhanced by addition of 20μmol/L noradrenalin and inhibited by 100μmol/L LaCl3(a non-selective Ca 2+ channel blocker);5μmol/L nifedipine did not induce any change.Overexpression of TRPC1 caused increased Ca 2+ influx.Five micromoles per liter nifedipine did not inhibit this elevation,whereas 100μmol/L LaCl3 did.CONCLUSION:In HL-7702 cells,there is a type of TRPC1-dependent Ca 2+ channel,which could be detected via NMT and inhibited by La3+.
文摘Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were incubated in ND96 (96 mmol/L NaCl, 2.0 mmol/L KCl, 1.8 mmol/L CaCl 2, 1.0 mmol/L MgCl 2, and 5.0 mmol/L HEPES, pH 7.4) at 4 ℃. Patch clamp recording (outside-out) were performed after 2-3 d. Isoflurane was administrated by the vaporizer driven by air, ethanol was applied by a closed, manual-controlled administration system. Different test potentials from 0 to 10 mV were given to observe changes of currents. Results: 0.7 mmol/L and 1.2 mmol/L of isoflurane could inhibit BK currents obviously at different command potentials, but 50 mmol/L, 100 mmol/L, or 200 mmol/L of ethanol had no any effect on BK currents. Conclusion: Clinical concentration of isoflurane can distinctly inhibit isolating BK currents.
文摘The wound is induced by several mechanical and metabolic factors.In the etiology of the wound recovery,excessive oxidative stress,calcium ion(Ca^(2+))influx,and apoptosis have important roles.Ca^(2+)-permeable TRPM2 channel is activated by oxidative stress.Protective roles of Hypericum perforatum extract(HP)on the mechanical nerve injury-induced apoptosis and oxidative toxicity through regulation of TRPM2 in the experimental animals were recently reported.The potential protective roles in HP treatment were evaluated on the TRPM2-mediated cellular oxidative toxicity in the renal epithelium(MPK)cells.The cells were divided into three groups as control,wound,and wound+HP treatment(75μM for 72 h).Wound diameters were more importantly decreased in the wound+HP group than in the wound group.In addition,the results of laser confocal microscopy analyses indicated protective roles of HP and TRPM2 antagonists(N-(p-Amylcinnamoyl)anthranilic acid and 2-aminoethyl diphenylborinate)against the wound-induced increase of Ca^(2+) influx and mitochondrial ROS production.The wound-induced increase of early(annexin V-FITC)apoptosis and late(propidium iodide)apoptosis were also decreased in the cells by the HP treatment.In conclusion,HP treatment acted protective effects against wound-mediated oxidative cell toxicity and apoptosis through TRPM2 inhibition.These effects may be attributed to their potent antioxidant effect.