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
AIM: To explore the possibility of using the Noninvasive 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 no...AIM: To explore the possibility of using the Noninvasive 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 TRPCl 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 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 (a non-selective Ca^2+ channel blocker); 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2+ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION: In HL-7702 cells, there is a type of TRPCl-dependent Ca^2+ channel, which could be detected v/a NMT and inhibited by La^3+.展开更多
BACKGROUND: Previous studies of curcumin have focused mainly on its cytotoxic properties for antitumor therapy. There are few studies addressing the application of curcumin in the prevention and treatment of nervous ...BACKGROUND: Previous studies of curcumin have focused mainly on its cytotoxic properties for antitumor therapy. There are few studies addressing the application of curcumin in the prevention and treatment of nervous system diseases. OBJECTIVE: To observe the protective effect of curcumin against tumor necrosis factor-alpha (TNF-α)-induced neuronal damage in the rat hippocampus and to explore the intervention effect of curcumin on Ca^2+ influx following neuronal damage. DESIGN, TIME AND SETTING: A cell morphological and physiological study was performed at the Institute of Brain Research, Medical College of Jinan University, China, from December 2006 to June 2007. MATERIALS: Curcumin (Sigma, USA) and TNF-α (Sigma, USA) were used in this study. METHODS: Hippocampal neurons were isolated from one-day neonatal rats and primarily cultured for 5 days. Following this they received 1 pmol/L curcumin and 100 ng/mL TNF-a pre-treatment. Dynamic morphological changes were observed for 1 hour by inverted microscopy. At 48 hours post-treatment, static morphological characteristics of the neurons were observed using inverted microscopy. Subsequently, hippocampal neurons were primarily cultured for 7 days, after receiving 1 pmol/L curcumJn and 4.5 ng/mL TNF-a pre-treatment. Intracellular free Ca^2+ was measured using Fluo 3/acetoxymethyl ester. MAIN OUTCOME MEASURES: Effects of curcumin on TNF-a-induced neuronal damage and Ca^2+ influx in the rat hippocampus were measured. RESULTS: Following curcumin treatment, TNF-a-induced neurons grew as normal. TNF-a induced a rapid Ca^2+ influx into the neuronal cytoplasm; however, Ca2+ fluorescence intensity only slightly increased when neurons were co-perfused with curcumin and TNF-α. CONCLUSION: Curcumin has a protective effect on rat hippocampal neurons possibly by reducing the TNF-α-induced rapid Ca^2+ influx into neuronal cytoplasm and by maintaining the Ca^2+ homeostasis.展开更多
Objective:To study the effect of crude methanol and n-hexane extracts of Hypericum connatum(H.connatum) and Hypericum caprifoliatum on trophoblast-like cells.Methods:BeWo and JEG-3 trophoblast-like cells were submitte...Objective:To study the effect of crude methanol and n-hexane extracts of Hypericum connatum(H.connatum) and Hypericum caprifoliatum on trophoblast-like cells.Methods:BeWo and JEG-3 trophoblast-like cells were submitted to different extract concentrations(1.5,10 and 15 μg/mL) and evaluated in relation to cell viability and in titro trophoblast differentiation and function.Cell viability was evaluated using WST-1 reagent.Differentiation was measured by luciferase production,hCG production/release,and mitogenactivated protein kinase signaling pathway activation.The function of the trophoblast-like cells was measured by^(25)Ca^(2*) influx evaluation.Results:The results showed a decrease in cell viability/proliferation.Both plants and different extracts induced a significant decrease in hCG production/release and luciferase production.H.connatum did not cause mitogen-activated protein kinase signaling pathway disturbance;however,Hypericum caprifoliatum n-hexane extract at 15 μg/mL inhibited extracellular signalregulated kinase 1/2 activation.The significant increase in Ca^(2+) influx by JEG-3 cells was seen after short and long incubation times with H.connatum methanolie extract at 15 μg/mL.Conclusions:The results indicated that these two Hypericum species extracts can interfere on trophoblast differentiation and Ca^(2+)influx,according to their molecular diversity.Although in vivo experiments are necessary to establish their action on placental formation and function,this study suggests that attention must be paid to the potential toxic effect of these plants.展开更多
Jujube contains abundant cyclic adenosine monophosphate(cAMP)and the ultrasonic-assisted pectinase extraction(UAPE)conditions for obtaining the maximum cAMP yield from jujube were optimized.Orthogonal array design was...Jujube contains abundant cyclic adenosine monophosphate(cAMP)and the ultrasonic-assisted pectinase extraction(UAPE)conditions for obtaining the maximum cAMP yield from jujube were optimized.Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield.The results showed that the optimal cAMP yield(783.0μg/g)was derived at ratio of liquid to solid 5 mL/g,ratio of pectinase to raw material 1.5%,time 60 min and temperature 40℃.Moreover,the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E(IgE)and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia(RBL-2 H3)cells using dinitrophenylated(DNP)-bovine serum albumin(BSA)-IgE.The results showed that cAMP interfered with sensitized cells,effectively inhibited the occurrence of basophil degranulation in dose dependence,and significantly reduced the activity ofβ-hexosamindase(β-hex),at the optimal concentration of 50μg/mL.The level of anti-inflammatory factor interleukin-10(IL-10)was promoted and the content of pro-inflammatory factor tumor necrosis factor-α(TNF-α)was suppressed by cAMP.In addition,influx of intracellular Ca^(2+) was repressed effectively.Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca^(2+),with the prevention of allergy symptoms.展开更多
The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that t...The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P<O. 01) by verapamil (1 μmol/L) after infection of heart cells for 48h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (Iμmol/L and 10 nmo/L) at the same time for 48h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P<O. 05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e. g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn’t a sensible choice for therapy in early stage of virus infection with cardiac symptoms.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 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 Noninvasive 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 TRPCl 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 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 (a non-selective Ca^2+ channel blocker); 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2+ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION: In HL-7702 cells, there is a type of TRPCl-dependent Ca^2+ channel, which could be detected v/a NMT and inhibited by La^3+.
基金the grant from Medical Science Foundation of Guangdong Province,No.A2006334the Natural Science Foundation of Guangdong Province,No.06105246,No.9151040701000008the Science and Technology Project of Guangzhou City,No.2007J1-C0041
文摘BACKGROUND: Previous studies of curcumin have focused mainly on its cytotoxic properties for antitumor therapy. There are few studies addressing the application of curcumin in the prevention and treatment of nervous system diseases. OBJECTIVE: To observe the protective effect of curcumin against tumor necrosis factor-alpha (TNF-α)-induced neuronal damage in the rat hippocampus and to explore the intervention effect of curcumin on Ca^2+ influx following neuronal damage. DESIGN, TIME AND SETTING: A cell morphological and physiological study was performed at the Institute of Brain Research, Medical College of Jinan University, China, from December 2006 to June 2007. MATERIALS: Curcumin (Sigma, USA) and TNF-α (Sigma, USA) were used in this study. METHODS: Hippocampal neurons were isolated from one-day neonatal rats and primarily cultured for 5 days. Following this they received 1 pmol/L curcumin and 100 ng/mL TNF-a pre-treatment. Dynamic morphological changes were observed for 1 hour by inverted microscopy. At 48 hours post-treatment, static morphological characteristics of the neurons were observed using inverted microscopy. Subsequently, hippocampal neurons were primarily cultured for 7 days, after receiving 1 pmol/L curcumJn and 4.5 ng/mL TNF-a pre-treatment. Intracellular free Ca^2+ was measured using Fluo 3/acetoxymethyl ester. MAIN OUTCOME MEASURES: Effects of curcumin on TNF-a-induced neuronal damage and Ca^2+ influx in the rat hippocampus were measured. RESULTS: Following curcumin treatment, TNF-a-induced neurons grew as normal. TNF-a induced a rapid Ca^2+ influx into the neuronal cytoplasm; however, Ca2+ fluorescence intensity only slightly increased when neurons were co-perfused with curcumin and TNF-α. CONCLUSION: Curcumin has a protective effect on rat hippocampal neurons possibly by reducing the TNF-α-induced rapid Ca^2+ influx into neuronal cytoplasm and by maintaining the Ca^2+ homeostasis.
基金Supported by Canadian Institutes of Health Research(CIHRNET 54002)
文摘Objective:To study the effect of crude methanol and n-hexane extracts of Hypericum connatum(H.connatum) and Hypericum caprifoliatum on trophoblast-like cells.Methods:BeWo and JEG-3 trophoblast-like cells were submitted to different extract concentrations(1.5,10 and 15 μg/mL) and evaluated in relation to cell viability and in titro trophoblast differentiation and function.Cell viability was evaluated using WST-1 reagent.Differentiation was measured by luciferase production,hCG production/release,and mitogenactivated protein kinase signaling pathway activation.The function of the trophoblast-like cells was measured by^(25)Ca^(2*) influx evaluation.Results:The results showed a decrease in cell viability/proliferation.Both plants and different extracts induced a significant decrease in hCG production/release and luciferase production.H.connatum did not cause mitogen-activated protein kinase signaling pathway disturbance;however,Hypericum caprifoliatum n-hexane extract at 15 μg/mL inhibited extracellular signalregulated kinase 1/2 activation.The significant increase in Ca^(2+) influx by JEG-3 cells was seen after short and long incubation times with H.connatum methanolie extract at 15 μg/mL.Conclusions:The results indicated that these two Hypericum species extracts can interfere on trophoblast differentiation and Ca^(2+)influx,according to their molecular diversity.Although in vivo experiments are necessary to establish their action on placental formation and function,this study suggests that attention must be paid to the potential toxic effect of these plants.
基金supported by grant from the National Key Research and Development Program of China(2018YFC1602201)the Open Research Fund Program of Beijing Key Lab of Plant Resource Research and Development,Beijing Technology and Business University(PRRD-2021-YB8)+1 种基金the National Natural Science Fund(31601395)the Key Program for Shaanxi Science and Technology(2020NY-146)。
文摘Jujube contains abundant cyclic adenosine monophosphate(cAMP)and the ultrasonic-assisted pectinase extraction(UAPE)conditions for obtaining the maximum cAMP yield from jujube were optimized.Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield.The results showed that the optimal cAMP yield(783.0μg/g)was derived at ratio of liquid to solid 5 mL/g,ratio of pectinase to raw material 1.5%,time 60 min and temperature 40℃.Moreover,the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E(IgE)and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia(RBL-2 H3)cells using dinitrophenylated(DNP)-bovine serum albumin(BSA)-IgE.The results showed that cAMP interfered with sensitized cells,effectively inhibited the occurrence of basophil degranulation in dose dependence,and significantly reduced the activity ofβ-hexosamindase(β-hex),at the optimal concentration of 50μg/mL.The level of anti-inflammatory factor interleukin-10(IL-10)was promoted and the content of pro-inflammatory factor tumor necrosis factor-α(TNF-α)was suppressed by cAMP.In addition,influx of intracellular Ca^(2+) was repressed effectively.Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca^(2+),with the prevention of allergy symptoms.
文摘The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P<O. 01) by verapamil (1 μmol/L) after infection of heart cells for 48h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (Iμmol/L and 10 nmo/L) at the same time for 48h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P<O. 05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e. g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn’t a sensible choice for therapy in early stage of virus infection with cardiac symptoms.