The present study observed the effects of MCI-186 on the intracellular calcium ion concentra-tion ([Ca2+]i) and membrane fluidity of hippocampal neurons in Alzheimer's disease (AD) model rats to validate the neuro...The present study observed the effects of MCI-186 on the intracellular calcium ion concentra-tion ([Ca2+]i) and membrane fluidity of hippocampal neurons in Alzheimer's disease (AD) model rats to validate the neuroprotective effects of MCI-186.Compared with normal and sham-operated rats,the escape latency was obviously prolonged,spanning platform times were obviously reduced,[Ca2+]i was increased,and microviscosity η value was increased in AD rats.MCI-186 at 0.5 mg/mL and 0.2 mg/mL obviously shortened escape latency,increased spanning platform times and decreased [Ca2+]i and microviscosity η values in AD rats at 7 and 17 days after induction of the model.The differences in the above-mentioned indices between normal and MCI-186-treated rats were statistically significant.MCI-186 at 0.2 mg/mL yielded better curative effects than 0.5 mg/mL MCI-186.These findings suggest that MCI-186 improves learning and memory abilities in AD rats by decreasing [Ca2+]i and increasing membrane fluidity of hippocampal neurons.展开更多
In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique ...In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique has been previously demonstrated to effectively improve the erosion resistance of slopes.Seawater contains magnesium ions(Mg2+)with a higher concentration than calcium ions(Ca2+);therefore,Mg2+and Ca2+were used together for bio-cementation in this study at various Mg2+/Ca2+ratios as the microbially induced magnesium and calcium precipitation(MIMCP)treatment.Slope angles,surface strengths,precipitation contents,major phases,and microscopic characteristics of precipitation were used to evaluate the treatment effects.Results showed that the MIMCP treatment markedly enhanced the erosion resistance of slopes.Decreased Mg2+/Ca2+ratios resulted in a smaller change in angles and fewer soil losses,especially the Mg2+concentration below 0.2 M.The decreased Mg2+/Ca2+ratio achieved increased precipitation contents,which contributed to better erosion resistance and higher surface strengths.Additionally,the production of aragonite would benefit from elevated Mg2+concentrations and a higher Ca2+concentration led to more nesquehonite in magnesium precipitation crystals.The slopes with an initial angle of 53°had worse erosion resistance than the slopes with an initial angle of 35°,but the Mg2+/Ca2+ratios of 0.2:0.8,0.1:0.9,and 0:1.0 were effective for both slope stabilization and erosion mitigation to a great extent.The results are of great significance for the application of MIMCP to improve erosion resistance of foreshore slopes and the MIMCP technique has promising application potential in marine engineering.展开更多
Hepatoblastoma is the most frequent liver malignancy in children.HepG2 has been discovered as a hepatoblastoma-derived cell line and tends to form clumps in culture.Intriguingly,we observed that the addition of calciu...Hepatoblastoma is the most frequent liver malignancy in children.HepG2 has been discovered as a hepatoblastoma-derived cell line and tends to form clumps in culture.Intriguingly,we observed that the addition of calcium ions reduced cell clumping and disassociated HepG2 cells.The calcium signal is in connection with a series of processes critical in the tumorigenesis.Here,we demonstrated that extracellular calcium ions induced morphological changes and enhanced the epithelial-mesenchymal transition in HepG2 cells.Mechanistically,calcium ions promoted HepG2 proliferation and migration by up-regulating the phosphorylation levels of focal adhesion kinase(FAK),protein kinase B,and p38 mitogen-activated protein kinase.The inhibitor of FAK or Ca2+/calmodulin-dependent kinaseⅡ(CaMKⅡ)reversed the Ca2+-induced effects on HepG2 cells,including cell proliferation and migration,epithelial-mesenchymal transition protein expression levels,and phosphorylation levels of FAK and protein kinase B.Moreover,calcium ions decreased HepG2 cells'sensitivity to cisplatin.Furthermore,we found that the expression levels of FAK and CaMKⅡwere increased in hepatoblastoma.The group with high expression levels of FAK and CaMKⅡexhibited significantly lower ImmunoScore as well as CD8+T and NK cells.The expression of CaMKⅡwas positively correlated with that of PDCD1 and LAG3.Correspondingly,the expression of FAK was negatively correlated with that of TNFSF9,TNFRSF4,and TNFRSF18.Collectively,extracellular calcium accelerates HepG2 cell proliferation and migration via FAK and CaMKⅡand enhances cisplatin resistance.FAK and CaMKⅡshape immune cell infiltration and responses in tumor microenvironments,thereby serving as potential targets for hepatoblastoma.展开更多
The precise mechanism underlying the effects of anti-CD4 antibody and calcium ions(Ca^(2+)) in peanut allergy remains unknown.C3 H/HeJ mice sensitized with peanut protein extract(PPE)were injected with anti-CD4 antibo...The precise mechanism underlying the effects of anti-CD4 antibody and calcium ions(Ca^(2+)) in peanut allergy remains unknown.C3 H/HeJ mice sensitized with peanut protein extract(PPE)were injected with anti-CD4 antibodies for 4 weeks.Stimulation with PPE increased the specific immunoglobulin E(IgE),cytokine,histamine,and mMcp-1 levels,upregulated decorin(Dcn)expression,induced Ca^(2+) inflow in the spleen,and augmented the expression of the transcription factors GATA-3 and Foxp3,which resulted in Th2 and Treg cell activation.Notably,the Ca^(2+) levels were positively correlated with the histamine,interleukin(IL)-4,IL-5,and IL-13 levels,and negatively correlated with IL-10 levels.However,administration of anti-CD4 antibodies markedly alleviated allergic symptoms,activated T cells,and reduced Ca^(2+) inflow,cytokine,histamine,mMcp-1,and the IgHG3,CXCLI2,MMP2 and FABP4 gene.Our results indicated that anti-CD4 antibodies can ameliorate PPE-induced allergy,which is probably related to the suppression of Ca^(2+) inflow,and inhibiting histamine,cytokine and IgHG3,CXCL12,MMP2,and FABP4,thus exerting a protective effect against PPEsensitized food allergy.展开更多
Four self-assembled monolayer surfaces terminated with–COOH,–OH,–NH_(2)and–CH_(3)functional groups are used to direct the biomineralization processes of calcium carbonate(CaCO_(3))in low Ca^(2+)concentration,and t...Four self-assembled monolayer surfaces terminated with–COOH,–OH,–NH_(2)and–CH_(3)functional groups are used to direct the biomineralization processes of calcium carbonate(CaCO_(3))in low Ca^(2+)concentration,and the mechanism of nucleation and initial crystallization within 12 h was further explored.On-COOH surface,nucleation occurs mainly via ion aggregation mechanism while prenucleation ions clusters may be also involved.On-OH and-NH_(2)surfaces,however,nucleation forms via calcium carbonate clusters,which aggregate in solution and then are adsorbed onto surfaces following with nucleation of amorphous calcium carbonate(ACC).Furthermore,strongly negative-charged-COOH surface facilitates the direct formation of calcites,and the-OH and-NH_(2)surfaces determine the formation of vaterites with preferred crystalline orientations.Neither ACC nor crystalline CaCO_(3)is observed on-CH_(3)surface.Our findings present a valuable model to understand the CaCO_(3)biomineralization pathway in natural system where functional groups composition plays a determining role during calcium carbonate crystallization.展开更多
Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. Intracellula...Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. Intracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripterigium Wilfordii Glycosides (TMG) significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of intracellular calcium concentrations wasn’t the only way for proliferation.展开更多
Background: Dialysis centres around the world use different concentrations of calcium in dialysate solution,ranging from 1. 25 to 1. 75 mmol / L. However,a dialysate concentration of 1. 25 mmol / L is recommended. [1]...Background: Dialysis centres around the world use different concentrations of calcium in dialysate solution,ranging from 1. 25 to 1. 75 mmol / L. However,a dialysate concentration of 1. 25 mmol / L is recommended. [1] Higher or lower dialysate calcium concentrations are indicated in patients,depending on their co-morbid factors. We explored the effects of using a calcium dialysate solution of 1. 50 mmol / L compared to a 1. 75 mmol / L calcium dialysate solution on the Blood Pressure (BP) ,serum concentrations of Calcium,Parathyroid Hormone (PTH) and Aldosterone in chronic hemodialysis (HD) patients. Method: 42 patients were enrolled in the study. First a 1. 50 mmol / L low calcium dialysate solution (LCDS) was used for 4 hour dialysis,and for the next session of HD,a 1. 75 mmol / L (NCDS) normal calcium dialysate solution was used. Blood pressure was measured at 5 intervals of time: pre HD,at 60,120,180 and 240 minutes into the HD session. Pre and post HD blood samples were taken for serum calcium,PTH and Aldosterone levels. Results: All 42 patients completed the study. With LCDS,the post HD serum calcium levels were (2. 51 ± 0. 14) mmol / L,compared to (2. 85 ± 0. 17) mmol / L for NCDS (P < 0. 01) . A post HD serum PTH level of (80. 6 ± 144. 93) pg / ml was observed when using LCDS,whereas a (52. 25 ± 115. 89) pg / ml serum PTH level was noted with NCDS (P < 0. 01) . As for aldosterone,a post HD value of (161. 77 ± 80. 42) ng / L was obtained with LCDS and (165. 50 ± 78. 84) ng / L with NCDS (P < 0. 01) . The mean post HD systolic blood pressure was (129. 17 ± 25. 42) mmHg with LCDS dialysis compared to (132. 50 ± 20. 32) mmHg for NCDS dialysis (P < 0. 01) and the diastolic BP values observed were (75. 10 ±10. 34) mmHg and (78. 26 ±11. 63) mm Hg(P <0. 01) ,respectively. Conclusion: LCDS can more effectively improve hypercalcemic status in dialysis patients than NCDS. Using LCDS stimulates the secretion of PTH more than when using NCDS. LCDS decreases aldosterone levels more than NCDS. Patients undergoing dialysis with LCDS have a lower post dialysis BP compared to those using NCDS. LCDS has a greater effect in decreasing both the post systolic and diastolic blood pressure than NCDS. Serum calcium,PTH and aldosterone levels have a greater decreasing effect on BP in LCDS than NCDS. Dialysate calcium profiling might be used as a means of therapy to control hypercalcemia, especially in patients who are hemodynamically stable.展开更多
Objective:To explore the effects of Iptakalim on intracellular free calcium concentration and on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1(ET-1) in vitro.Metho...Objective:To explore the effects of Iptakalim on intracellular free calcium concentration and on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1(ET-1) in vitro.Methods:A cell culture model,[~3H]-thymidine([3~H]-TdR) incorporation test and confocal microscope were used to observe proliferation and intracellular free calcium concentration([Ca^(2+)]_i) of rabbit PASMC induced by ET-1 in vitro.Results:The value of [3~H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group.Iptakalim at the concentration of 10^(-7)mol/L,10^(-6) mol/L,10^(-5) mol/L lowered [~3H]-TdR incorporation by (19.8±4.6)%,(41.2±9.5)%,(54.7±10.1)%,respectively,compared with the value of the cells treated with ET-1(P<0.01); The intracellular fluorescence intensity of PASMC in ET-1 group was increased from 73.70±10.12 to 143.84±28.23,significantly higher than that in control group(P<0.01);whereas with Iptakalim,the fluorescence intensity(FI) was only increased from 74.30±10.20 to 86.03±9.82,significantly lower than that in ET-1 group(P<0.01).Conclusion:Iptakalim inhibited proliferation of PASMC and decreased intracellular free calcium concentration of cultured rabbit PASMC induced by ET-1.展开更多
The microflotation of three single minerals,mixed coal–kaolinite and mixed coal–montmorillonite were examined to study the effects of clay and calcium ions on coal flotation.The results show that the ash content of ...The microflotation of three single minerals,mixed coal–kaolinite and mixed coal–montmorillonite were examined to study the effects of clay and calcium ions on coal flotation.The results show that the ash content of flotation concentrate increases by 3%in the presence of clay minerals,and the ash content would further increase by 3%in co-presence of clay minerals and high concentration of Ca2+.Scanning electron microscope(SEM)images and elemental spectrum analysis indicate that fne clay particles that coat on the coal surface,which is called slime coating,can affect the coal flotation.The slime coating would be induced much more easily in the presence of Ca2+.展开更多
The mathematical models of the kinetics of the layer growth at different ion nitriding condi-tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based onthese models the expression of nitrogen...The mathematical models of the kinetics of the layer growth at different ion nitriding condi-tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based onthese models the expression of nitrogen concentration profile of ion nitrided layers have beendeduced with profile simulating method.They areC<sub>=</sub>C<sub>min</sub><sup>+</sup>（P<sub>4</sub>）/（ξ<sub>1</sub>-x）+（P<sub>5</sub>）/(ξ<sub>10</sub><sup>2</sup>)（ξ<sub>1</sub>-x）<sup>2</sup>C<sub>γ′</sub>=C<sub>min</sub><sup>γ′</sup>+（P<sub>1</sub>）/(ξ<sub>21</sub>)（ξ<sub>2</sub>-x）+（P<sub>2</sub>）/(ξ<sub>21</sub><sup>2</sup>)（ξ<sub>2</sub>-x）<sup>2</sup>C<sub>α</sub>=C<sub>min</sub><sup>α</sup>+(C<sub>33</sub>)/(C<sub>33</sub>)/(ξ<sub>32</sub>)（ξ<sub>3</sub>-x）<sup>3</sup>Using these models,the kinetics of layer growth and the nitrogen concentration profile of ionnitrided layers were sinulated on Apple-Ⅱ computer.Results show that the simulated curvescoincide quite well with the experimental data.展开更多
Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reducti...Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.展开更多
Negative air ions(NAIs)benefit the mental and physical health of humans,but rapid urbanization can decrease the abundance of NAIs.Quantifying the spatial and seasonal distribution of NAIs and determining the factors t...Negative air ions(NAIs)benefit the mental and physical health of humans,but rapid urbanization can decrease the abundance of NAIs.Quantifying the spatial and seasonal distribution of NAIs and determining the factors that infl uence the concentration during urbanization is thus essential.In the present study of a typical developing urban district in southern China,negative air ion concentrations(NAICs)in 60 forests sites and 30 urban green spaces were quantifi ed on seven consecutive days in each of the four seasons.Large seasonal variations in NAIC were revealed in forests and urban green spaces with trough values in summer.NAIC progressively decreased from forests to urban green spaces and was infl uenced by local land morphology,vegetation characteristics,and climatic factors.The vast,heavily vegetated northeastern region was the richest area for NAIs,whereas the narrow central region(urbanized area)was the poorest,implying dramatic impacts of urbanization on the spatial distribution of NAIs.The relationship between air temperature and NAIC was better fi tted with a quadratic equation than a linear equation.Moreover,the NAIC was more sensitive to local morphology in urban green spaces than in urban forests,indicating the vulnerability of NAIs in urbanized areas.Therefore,the appropriate design of local urban morphology is critical.展开更多
The formation of calcium titanate in the carbothermic reduction of vanadium titanomagnetite concentrate(VTC)by adding CaCO3 was investigated.Thermodynamic analysis was employed to show the feasibility of calcium titan...The formation of calcium titanate in the carbothermic reduction of vanadium titanomagnetite concentrate(VTC)by adding CaCO3 was investigated.Thermodynamic analysis was employed to show the feasibility of calcium titanate formation by the reaction of ilmenite and Ca CO3 in a reductive atmosphere,where ilmenite is more easily reduced by CO or carbon in the presence of CaCO3.The effects of CaCO3 dosage and reduction temperature on the phase transformation and metallization degree were also investigated in an actual roasting test.Appropriate increase of CaCO3 dosages and reduction temperatures were found to be conducive to the formation of calcium titanate,and the optimum conditions were a CaCO3 dosage of 18 wt%and a reduction temperature of 1400°C.Additionally,scanning electron microscopy–energy dispersive spectrometry(SEM–EDS)analysis shows that calcium titanate produced via the carbothermic reduction of VTC by CaCO3 addition was of higher purity with particle size approximately 50μm.Hence,the separation of calcium titanate and metallic iron will be the focus in the future study.展开更多
Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigate...Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigated using immersion corrosion test in NaCl solutions of different chloride ion concentrations viz.,0.01 M,0.2 M,0.6 M and 1 M.The corroded surface was characterized by an optical microscope and X-ray diffraction.The results showed that the corrosion deterioration of uncoated and coated samples were significantly influenced by chloride ion concentration.The uncoated magnesium and alumina coatings were found to offer a superior corrosion resistance in lower chloride ion concentration NaCl solutions(0.01 M and 0.2 M NaCl).On the other hand the coatings and Mg alloy substrate were found to be highly susceptible to localized damage,and could not provide an effective corrosion protection in solutions containing higher chloride concentrations(0.6 M and 1 M).It was found that the corrosion resistance of the ceramic coatings and base metal gets deteriorated with the increase in the chloride concentrations.展开更多
By using calcium ion selective elatrode (Ca ISE) as indicating electrode, saturated calomel electrode (SCE) as reference electrode and EGTA as titrant, calcium in seawater was determined by potentiometric titration in...By using calcium ion selective elatrode (Ca ISE) as indicating electrode, saturated calomel electrode (SCE) as reference electrode and EGTA as titrant, calcium in seawater was determined by potentiometric titration in borate buffer solution. This method can reduce observation errors in the determination of the endpoint, and thus provide better analytical precision(<0.08%) than present complexometric titration.展开更多
The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II),such as ZnSO4g7H2O,ZnO,Zn(NO3)2·6H2O and ZnCl2,was analyzed.Changes in consistency,setting time,hydration heat flow,hydratio...The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II),such as ZnSO4g7H2O,ZnO,Zn(NO3)2·6H2O and ZnCl2,was analyzed.Changes in consistency,setting time,hydration heat flow,hydration heat amount,ion concentration in solution,and hydration products were found upon the addition of different Zn^2+.The water consumption of standard consistency of CAC is decreased with different Zn^2+.Zn^2+ can delay the initial hydration of CAC.The induction period of cement with Zn^2+ is longer than that of CAC,especially the reaction time of the acceleration period is extended.Zn^2+ can promote hydration hydrate of CAC at 24 h.The characteristic diffraction peaks of CA and CA2 in CAC with different Zn^2+ are significantly reduced.It can inhibit the formation of CAH10 and promote the formation C3AH6 and AH3 in hydration products at 24 h.展开更多
Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no descr...Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no description of an ideal operation approach to endocochlear potential and potassium ion concentration measurements.In this article,we describe a pre-auricular surgical approach to access the middle and inner ear for endocochlear potential and potassium ion concentration measures in mini pig models.Ten one-week old normal mini pigs were used in the study.The bulla of the temporal bone was accessed via a pre-auricular approach for endocochlear potential and potassium ion concentration measurements.The condition of the animals during the first post—experiment 24 h was observed.One animal died during surgery.The preauricular approach improved protection and preservation of relevant nervous and vascular elements including the facial nerve and carotid artery.So,the pre-auricular approach can be used for endocochlear potential and potassium ion concentration measurements with improved nerve and artery preservation mini pigs.展开更多
Vanadium-based cathodes have attracted great interest in aqueous zinc ion batteries(AZIBs)due to their large capacities,good rate performance and facile synthesis in large scale.However,their practical application is ...Vanadium-based cathodes have attracted great interest in aqueous zinc ion batteries(AZIBs)due to their large capacities,good rate performance and facile synthesis in large scale.However,their practical application is greatly hampered by vanadium dissolution issue in conventional dilute electrolytes.Herein,taking a new potassium vanadate K0.486V2O5(KVO)cathode with large interlayer spacing(~0.95 nm)and high capacity as an example,we propose that the cycle life of vanadates can be greatly upgraded in AZIBs by regulating the concentration of ZnCl2 electrolyte,but with no need to approach“water-in-salt”threshold.With the optimized moderate concentration of 15 m ZnCl2 electrolyte,the KVO exhibits the best cycling stability with ~95.02% capacity retention after 1400 cycles.We further design a novel sodium carboxymethyl cellulose(CMC)-moderate concentration ZnCl2 gel electrolyte with high ionic conductivity of 10.08 mS cm^-1 for the first time and assemble a quasi-solid-state AZIB.This device is bendable with remarkable energy density(268.2 Wh kg^−1),excellent stability(97.35% after 2800 cycles),low self-discharge rate,and good environmental(temperature,pressure)suitability,and is capable of powering small electronics.The device also exhibits good electrochemical performance with high KVO mass loading(5 and 10 mg cm^-2).Our work sheds light on the feasibility of using moderately concentrated electrolyte to address the stability issue of aqueous soluble electrode materials.展开更多
基金the Natural Science Foundation of Heilongjiang Province,No.D200807Projects of Clinical Medicine in Science and Technology Development of Jiangsu University,No.JLY20080013
文摘The present study observed the effects of MCI-186 on the intracellular calcium ion concentra-tion ([Ca2+]i) and membrane fluidity of hippocampal neurons in Alzheimer's disease (AD) model rats to validate the neuroprotective effects of MCI-186.Compared with normal and sham-operated rats,the escape latency was obviously prolonged,spanning platform times were obviously reduced,[Ca2+]i was increased,and microviscosity η value was increased in AD rats.MCI-186 at 0.5 mg/mL and 0.2 mg/mL obviously shortened escape latency,increased spanning platform times and decreased [Ca2+]i and microviscosity η values in AD rats at 7 and 17 days after induction of the model.The differences in the above-mentioned indices between normal and MCI-186-treated rats were statistically significant.MCI-186 at 0.2 mg/mL yielded better curative effects than 0.5 mg/mL MCI-186.These findings suggest that MCI-186 improves learning and memory abilities in AD rats by decreasing [Ca2+]i and increasing membrane fluidity of hippocampal neurons.
基金funded by the National Natural Science Foundation of China(Grant No.51578147)Fundamental Research Funds for the Central Universities(Grant No.2242020R20025)Ningxia Science and Technology Department(Grant No.2020BFG02014).
文摘In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique has been previously demonstrated to effectively improve the erosion resistance of slopes.Seawater contains magnesium ions(Mg2+)with a higher concentration than calcium ions(Ca2+);therefore,Mg2+and Ca2+were used together for bio-cementation in this study at various Mg2+/Ca2+ratios as the microbially induced magnesium and calcium precipitation(MIMCP)treatment.Slope angles,surface strengths,precipitation contents,major phases,and microscopic characteristics of precipitation were used to evaluate the treatment effects.Results showed that the MIMCP treatment markedly enhanced the erosion resistance of slopes.Decreased Mg2+/Ca2+ratios resulted in a smaller change in angles and fewer soil losses,especially the Mg2+concentration below 0.2 M.The decreased Mg2+/Ca2+ratio achieved increased precipitation contents,which contributed to better erosion resistance and higher surface strengths.Additionally,the production of aragonite would benefit from elevated Mg2+concentrations and a higher Ca2+concentration led to more nesquehonite in magnesium precipitation crystals.The slopes with an initial angle of 53°had worse erosion resistance than the slopes with an initial angle of 35°,but the Mg2+/Ca2+ratios of 0.2:0.8,0.1:0.9,and 0:1.0 were effective for both slope stabilization and erosion mitigation to a great extent.The results are of great significance for the application of MIMCP to improve erosion resistance of foreshore slopes and the MIMCP technique has promising application potential in marine engineering.
基金funded by the Jiangsu Medical Scientific Research Project of Jiangsu Health Commission(to Q.Y.)the 789 Outstanding Talent Program of SAHNMU(Grant No.789ZYRC 202070102 to Q.Y.)+1 种基金the Guangzhou Key Medical Discipline Construction Project(to Q.Y.)the National Natural Science Foundation of China(Grant Nos.81870409 and 81671543 to Q.Y.).
文摘Hepatoblastoma is the most frequent liver malignancy in children.HepG2 has been discovered as a hepatoblastoma-derived cell line and tends to form clumps in culture.Intriguingly,we observed that the addition of calcium ions reduced cell clumping and disassociated HepG2 cells.The calcium signal is in connection with a series of processes critical in the tumorigenesis.Here,we demonstrated that extracellular calcium ions induced morphological changes and enhanced the epithelial-mesenchymal transition in HepG2 cells.Mechanistically,calcium ions promoted HepG2 proliferation and migration by up-regulating the phosphorylation levels of focal adhesion kinase(FAK),protein kinase B,and p38 mitogen-activated protein kinase.The inhibitor of FAK or Ca2+/calmodulin-dependent kinaseⅡ(CaMKⅡ)reversed the Ca2+-induced effects on HepG2 cells,including cell proliferation and migration,epithelial-mesenchymal transition protein expression levels,and phosphorylation levels of FAK and protein kinase B.Moreover,calcium ions decreased HepG2 cells'sensitivity to cisplatin.Furthermore,we found that the expression levels of FAK and CaMKⅡwere increased in hepatoblastoma.The group with high expression levels of FAK and CaMKⅡexhibited significantly lower ImmunoScore as well as CD8+T and NK cells.The expression of CaMKⅡwas positively correlated with that of PDCD1 and LAG3.Correspondingly,the expression of FAK was negatively correlated with that of TNFSF9,TNFRSF4,and TNFRSF18.Collectively,extracellular calcium accelerates HepG2 cell proliferation and migration via FAK and CaMKⅡand enhances cisplatin resistance.FAK and CaMKⅡshape immune cell infiltration and responses in tumor microenvironments,thereby serving as potential targets for hepatoblastoma.
基金supported by the National Natural Science Foundation of China(31972185)。
文摘The precise mechanism underlying the effects of anti-CD4 antibody and calcium ions(Ca^(2+)) in peanut allergy remains unknown.C3 H/HeJ mice sensitized with peanut protein extract(PPE)were injected with anti-CD4 antibodies for 4 weeks.Stimulation with PPE increased the specific immunoglobulin E(IgE),cytokine,histamine,and mMcp-1 levels,upregulated decorin(Dcn)expression,induced Ca^(2+) inflow in the spleen,and augmented the expression of the transcription factors GATA-3 and Foxp3,which resulted in Th2 and Treg cell activation.Notably,the Ca^(2+) levels were positively correlated with the histamine,interleukin(IL)-4,IL-5,and IL-13 levels,and negatively correlated with IL-10 levels.However,administration of anti-CD4 antibodies markedly alleviated allergic symptoms,activated T cells,and reduced Ca^(2+) inflow,cytokine,histamine,mMcp-1,and the IgHG3,CXCLI2,MMP2 and FABP4 gene.Our results indicated that anti-CD4 antibodies can ameliorate PPE-induced allergy,which is probably related to the suppression of Ca^(2+) inflow,and inhibiting histamine,cytokine and IgHG3,CXCL12,MMP2,and FABP4,thus exerting a protective effect against PPEsensitized food allergy.
基金This study is partly supported by Natural Science Foundation of China(No.21371106,21161003)the‘Twelfth Five-Year’National Technology Support Program(No.2012BAI17B02)+1 种基金Guangxi Natural Science Foundation of China(No.2012GXNSFDA053007,2011GXNSFA018044)the New Century National Hundred,Thousand and Ten Thousand Talent Project of Guangxi,and State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources(No.CMEMR2012-A12).
文摘Four self-assembled monolayer surfaces terminated with–COOH,–OH,–NH_(2)and–CH_(3)functional groups are used to direct the biomineralization processes of calcium carbonate(CaCO_(3))in low Ca^(2+)concentration,and the mechanism of nucleation and initial crystallization within 12 h was further explored.On-COOH surface,nucleation occurs mainly via ion aggregation mechanism while prenucleation ions clusters may be also involved.On-OH and-NH_(2)surfaces,however,nucleation forms via calcium carbonate clusters,which aggregate in solution and then are adsorbed onto surfaces following with nucleation of amorphous calcium carbonate(ACC).Furthermore,strongly negative-charged-COOH surface facilitates the direct formation of calcites,and the-OH and-NH_(2)surfaces determine the formation of vaterites with preferred crystalline orientations.Neither ACC nor crystalline CaCO_(3)is observed on-CH_(3)surface.Our findings present a valuable model to understand the CaCO_(3)biomineralization pathway in natural system where functional groups composition plays a determining role during calcium carbonate crystallization.
文摘Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured. Intracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripterigium Wilfordii Glycosides (TMG) significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of intracellular calcium concentrations wasn’t the only way for proliferation.
文摘Background: Dialysis centres around the world use different concentrations of calcium in dialysate solution,ranging from 1. 25 to 1. 75 mmol / L. However,a dialysate concentration of 1. 25 mmol / L is recommended. [1] Higher or lower dialysate calcium concentrations are indicated in patients,depending on their co-morbid factors. We explored the effects of using a calcium dialysate solution of 1. 50 mmol / L compared to a 1. 75 mmol / L calcium dialysate solution on the Blood Pressure (BP) ,serum concentrations of Calcium,Parathyroid Hormone (PTH) and Aldosterone in chronic hemodialysis (HD) patients. Method: 42 patients were enrolled in the study. First a 1. 50 mmol / L low calcium dialysate solution (LCDS) was used for 4 hour dialysis,and for the next session of HD,a 1. 75 mmol / L (NCDS) normal calcium dialysate solution was used. Blood pressure was measured at 5 intervals of time: pre HD,at 60,120,180 and 240 minutes into the HD session. Pre and post HD blood samples were taken for serum calcium,PTH and Aldosterone levels. Results: All 42 patients completed the study. With LCDS,the post HD serum calcium levels were (2. 51 ± 0. 14) mmol / L,compared to (2. 85 ± 0. 17) mmol / L for NCDS (P < 0. 01) . A post HD serum PTH level of (80. 6 ± 144. 93) pg / ml was observed when using LCDS,whereas a (52. 25 ± 115. 89) pg / ml serum PTH level was noted with NCDS (P < 0. 01) . As for aldosterone,a post HD value of (161. 77 ± 80. 42) ng / L was obtained with LCDS and (165. 50 ± 78. 84) ng / L with NCDS (P < 0. 01) . The mean post HD systolic blood pressure was (129. 17 ± 25. 42) mmHg with LCDS dialysis compared to (132. 50 ± 20. 32) mmHg for NCDS dialysis (P < 0. 01) and the diastolic BP values observed were (75. 10 ±10. 34) mmHg and (78. 26 ±11. 63) mm Hg(P <0. 01) ,respectively. Conclusion: LCDS can more effectively improve hypercalcemic status in dialysis patients than NCDS. Using LCDS stimulates the secretion of PTH more than when using NCDS. LCDS decreases aldosterone levels more than NCDS. Patients undergoing dialysis with LCDS have a lower post dialysis BP compared to those using NCDS. LCDS has a greater effect in decreasing both the post systolic and diastolic blood pressure than NCDS. Serum calcium,PTH and aldosterone levels have a greater decreasing effect on BP in LCDS than NCDS. Dialysate calcium profiling might be used as a means of therapy to control hypercalcemia, especially in patients who are hemodynamically stable.
基金This research was supported by the Innovation Fund of Nanjing Medical University(CX2003002)Natural Science Foundation of Jiangsu Province(BK2006246)+1 种基金Science Development Project of Jiangsu Science and Technology Department(BJ200051)and College Science Research Project of Jiangsu Education Department(OOKJBS20009).
文摘Objective:To explore the effects of Iptakalim on intracellular free calcium concentration and on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1(ET-1) in vitro.Methods:A cell culture model,[~3H]-thymidine([3~H]-TdR) incorporation test and confocal microscope were used to observe proliferation and intracellular free calcium concentration([Ca^(2+)]_i) of rabbit PASMC induced by ET-1 in vitro.Results:The value of [3~H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group.Iptakalim at the concentration of 10^(-7)mol/L,10^(-6) mol/L,10^(-5) mol/L lowered [~3H]-TdR incorporation by (19.8±4.6)%,(41.2±9.5)%,(54.7±10.1)%,respectively,compared with the value of the cells treated with ET-1(P<0.01); The intracellular fluorescence intensity of PASMC in ET-1 group was increased from 73.70±10.12 to 143.84±28.23,significantly higher than that in control group(P<0.01);whereas with Iptakalim,the fluorescence intensity(FI) was only increased from 74.30±10.20 to 86.03±9.82,significantly lower than that in ET-1 group(P<0.01).Conclusion:Iptakalim inhibited proliferation of PASMC and decreased intracellular free calcium concentration of cultured rabbit PASMC induced by ET-1.
基金The financial support from the National Basic Research Program of China(No.2012CB214902)the Fundamental Research Funds for the Central Universities of China(No.2013QH01)
文摘The microflotation of three single minerals,mixed coal–kaolinite and mixed coal–montmorillonite were examined to study the effects of clay and calcium ions on coal flotation.The results show that the ash content of flotation concentrate increases by 3%in the presence of clay minerals,and the ash content would further increase by 3%in co-presence of clay minerals and high concentration of Ca2+.Scanning electron microscope(SEM)images and elemental spectrum analysis indicate that fne clay particles that coat on the coal surface,which is called slime coating,can affect the coal flotation.The slime coating would be induced much more easily in the presence of Ca2+.
文摘The mathematical models of the kinetics of the layer growth at different ion nitriding condi-tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based onthese models the expression of nitrogen concentration profile of ion nitrided layers have beendeduced with profile simulating method.They areC<sub>=</sub>C<sub>min</sub><sup>+</sup>（P<sub>4</sub>）/（ξ<sub>1</sub>-x）+（P<sub>5</sub>）/(ξ<sub>10</sub><sup>2</sup>)（ξ<sub>1</sub>-x）<sup>2</sup>C<sub>γ′</sub>=C<sub>min</sub><sup>γ′</sup>+（P<sub>1</sub>）/(ξ<sub>21</sub>)（ξ<sub>2</sub>-x）+（P<sub>2</sub>）/(ξ<sub>21</sub><sup>2</sup>)（ξ<sub>2</sub>-x）<sup>2</sup>C<sub>α</sub>=C<sub>min</sub><sup>α</sup>+(C<sub>33</sub>)/(C<sub>33</sub>)/(ξ<sub>32</sub>)（ξ<sub>3</sub>-x）<sup>3</sup>Using these models,the kinetics of layer growth and the nitrogen concentration profile of ionnitrided layers were sinulated on Apple-Ⅱ computer.Results show that the simulated curvescoincide quite well with the experimental data.
基金financially supported by the National Natural Science Foundation of China(No.51674018)
文摘Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.
基金The authors acknowledge the volunteers who helped with the fi eld investigations.
文摘Negative air ions(NAIs)benefit the mental and physical health of humans,but rapid urbanization can decrease the abundance of NAIs.Quantifying the spatial and seasonal distribution of NAIs and determining the factors that infl uence the concentration during urbanization is thus essential.In the present study of a typical developing urban district in southern China,negative air ion concentrations(NAICs)in 60 forests sites and 30 urban green spaces were quantifi ed on seven consecutive days in each of the four seasons.Large seasonal variations in NAIC were revealed in forests and urban green spaces with trough values in summer.NAIC progressively decreased from forests to urban green spaces and was infl uenced by local land morphology,vegetation characteristics,and climatic factors.The vast,heavily vegetated northeastern region was the richest area for NAIs,whereas the narrow central region(urbanized area)was the poorest,implying dramatic impacts of urbanization on the spatial distribution of NAIs.The relationship between air temperature and NAIC was better fi tted with a quadratic equation than a linear equation.Moreover,the NAIC was more sensitive to local morphology in urban green spaces than in urban forests,indicating the vulnerability of NAIs in urbanized areas.Therefore,the appropriate design of local urban morphology is critical.
基金the National Natural Science Foundation of China(No.51674018)。
文摘The formation of calcium titanate in the carbothermic reduction of vanadium titanomagnetite concentrate(VTC)by adding CaCO3 was investigated.Thermodynamic analysis was employed to show the feasibility of calcium titanate formation by the reaction of ilmenite and Ca CO3 in a reductive atmosphere,where ilmenite is more easily reduced by CO or carbon in the presence of CaCO3.The effects of CaCO3 dosage and reduction temperature on the phase transformation and metallization degree were also investigated in an actual roasting test.Appropriate increase of CaCO3 dosages and reduction temperatures were found to be conducive to the formation of calcium titanate,and the optimum conditions were a CaCO3 dosage of 18 wt%and a reduction temperature of 1400°C.Additionally,scanning electron microscopy–energy dispersive spectrometry(SEM–EDS)analysis shows that calcium titanate produced via the carbothermic reduction of VTC by CaCO3 addition was of higher purity with particle size approximately 50μm.Hence,the separation of calcium titanate and metallic iron will be the focus in the future study.
文摘Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide.The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina(APS)coatings on AZ31B magnesium alloy was investigated using immersion corrosion test in NaCl solutions of different chloride ion concentrations viz.,0.01 M,0.2 M,0.6 M and 1 M.The corroded surface was characterized by an optical microscope and X-ray diffraction.The results showed that the corrosion deterioration of uncoated and coated samples were significantly influenced by chloride ion concentration.The uncoated magnesium and alumina coatings were found to offer a superior corrosion resistance in lower chloride ion concentration NaCl solutions(0.01 M and 0.2 M NaCl).On the other hand the coatings and Mg alloy substrate were found to be highly susceptible to localized damage,and could not provide an effective corrosion protection in solutions containing higher chloride concentrations(0.6 M and 1 M).It was found that the corrosion resistance of the ceramic coatings and base metal gets deteriorated with the increase in the chloride concentrations.
文摘By using calcium ion selective elatrode (Ca ISE) as indicating electrode, saturated calomel electrode (SCE) as reference electrode and EGTA as titrant, calcium in seawater was determined by potentiometric titration in borate buffer solution. This method can reduce observation errors in the determination of the endpoint, and thus provide better analytical precision(<0.08%) than present complexometric titration.
基金Funded by National Natural Science Foundation of China(No.51802235)State Key Laboratory of Silicate Materials for ArchitecturesWuhan University of Technology(No.SYSJJ2015-07)。
文摘The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II),such as ZnSO4g7H2O,ZnO,Zn(NO3)2·6H2O and ZnCl2,was analyzed.Changes in consistency,setting time,hydration heat flow,hydration heat amount,ion concentration in solution,and hydration products were found upon the addition of different Zn^2+.The water consumption of standard consistency of CAC is decreased with different Zn^2+.Zn^2+ can delay the initial hydration of CAC.The induction period of cement with Zn^2+ is longer than that of CAC,especially the reaction time of the acceleration period is extended.Zn^2+ can promote hydration hydrate of CAC at 24 h.The characteristic diffraction peaks of CA and CA2 in CAC with different Zn^2+ are significantly reduced.It can inhibit the formation of CAH10 and promote the formation C3AH6 and AH3 in hydration products at 24 h.
基金supported by grants from the National Basic Research Program of China(973 Program)(2012CB967900. 2012CB967901)the National Nature Science Foundation of China(NSFC81400472)
文摘Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no description of an ideal operation approach to endocochlear potential and potassium ion concentration measurements.In this article,we describe a pre-auricular surgical approach to access the middle and inner ear for endocochlear potential and potassium ion concentration measures in mini pig models.Ten one-week old normal mini pigs were used in the study.The bulla of the temporal bone was accessed via a pre-auricular approach for endocochlear potential and potassium ion concentration measurements.The condition of the animals during the first post—experiment 24 h was observed.One animal died during surgery.The preauricular approach improved protection and preservation of relevant nervous and vascular elements including the facial nerve and carotid artery.So,the pre-auricular approach can be used for endocochlear potential and potassium ion concentration measurements with improved nerve and artery preservation mini pigs.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.51872104,51972257 and 51672205)the National Key R&D Program of China(Grant No.2016YFA0202602)the Natural Science Foundation of Hubei Province(2018CFB581).
文摘Vanadium-based cathodes have attracted great interest in aqueous zinc ion batteries(AZIBs)due to their large capacities,good rate performance and facile synthesis in large scale.However,their practical application is greatly hampered by vanadium dissolution issue in conventional dilute electrolytes.Herein,taking a new potassium vanadate K0.486V2O5(KVO)cathode with large interlayer spacing(~0.95 nm)and high capacity as an example,we propose that the cycle life of vanadates can be greatly upgraded in AZIBs by regulating the concentration of ZnCl2 electrolyte,but with no need to approach“water-in-salt”threshold.With the optimized moderate concentration of 15 m ZnCl2 electrolyte,the KVO exhibits the best cycling stability with ~95.02% capacity retention after 1400 cycles.We further design a novel sodium carboxymethyl cellulose(CMC)-moderate concentration ZnCl2 gel electrolyte with high ionic conductivity of 10.08 mS cm^-1 for the first time and assemble a quasi-solid-state AZIB.This device is bendable with remarkable energy density(268.2 Wh kg^−1),excellent stability(97.35% after 2800 cycles),low self-discharge rate,and good environmental(temperature,pressure)suitability,and is capable of powering small electronics.The device also exhibits good electrochemical performance with high KVO mass loading(5 and 10 mg cm^-2).Our work sheds light on the feasibility of using moderately concentrated electrolyte to address the stability issue of aqueous soluble electrode materials.
