The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays a...The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays an important role in the central nervous system, where it is associated with glutamatergic signaling, and it is widely involved in inflammatory processes. Thus, diseases involving copper(Ⅱ) dyshomeostasis often have neurological symptoms, as exemplified by Alzheimer's and other diseases(such as Parkinson's and Wilson's diseases). Moreover, imbalanced copper ion concentrations have also been associated with diabetes and certain types of cancer, including glioma. In this paper, we propose a comprehensive overview of recent results that show the importance of these metal ions in several pathologies, mainly Alzheimer's disease, through the lens of the development and use of copper chelators as research compounds and potential therapeutics if included in multi-target hybrid drugs. Seeing how copper homeostasis is important for the well-being of animals as well as humans, we shortly describe the state of the art regarding the effects of copper and its chelators in agriculture, livestock rearing, and aquaculture, as ingredients for the formulation of feed supplements as well as to prevent the effects of pollution on animal productions.展开更多
The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The result...The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The results showed that,the copper grade of the concentrate obtained from seawater flotation decreased to 24.30%,compared to 24.60%in DI water.Concurrently,the recovery of chalcopyrite decreased from 51.39%to 38.67%,while the selectivity index(SI)also had a reduction from 2.006 to 1.798.The incorporation of ethylene diamine tetraacetic acid(EDTA),sodium silicate(SS),and sodium hexametaphosphate(SHMP)yielded an enhancement in the SI value,elevating it from 1.798 to 1.897,2.250 and 2.153,separately.It is particularly noteworthy that an excess of EDTA resulted in a SI value of merely 1.831.The mechanism of action was elucidated through analysis of surface charge measurements,X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR),extended Derjaguin-Landau Verwey-Overbeek(E-DLVO)theory,and density functional theory(DFT)calculations.展开更多
Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or C...Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.展开更多
During the crystallization of perovskite films,defects at Pb and I sites are generated,causing lattice mismatch and adversely affecting the performance of perovskite solar cells(PSCs).Herein,we introduced aπ-conjugat...During the crystallization of perovskite films,defects at Pb and I sites are generated,causing lattice mismatch and adversely affecting the performance of perovskite solar cells(PSCs).Herein,we introduced aπ-conjugated molecule with a dual-ring structure,namely CCA(3,4-ethylenedioxythiophene-2,5-dicarboxylic acid),as an additive to regulate the crystallization of perovskite films and passivate defects.As a bidentate Lewis base,CCA coordinates the bidentate carboxyl groups with free Pb^(2+)through the delocalized electrons of its conjugated ring.This coordination regulates lattice stress,repairs the 3D[PbI6]octahedra,stabilizes the perovskite framework,and guides the vertical orientation growth of grains.Simultaneously,the addition of CCA shifts the perovskite’s band structure towards p-type,achieving better energy-level alignment with the doped hole-transport layer(HTL)and suppressing non-radiative recombination.Consequently,the prepared CCA-doped single-junction devices exhibit an outstanding power conversion efficiency(PCE)of 24.90%,with a high open-circuit voltage(VOC)of 1.195,a high fill factor(FF)of 84.60%,and low FF loss.The optimized films and devices show enhanced long-term stability,retaining 80.1%of the initial efficiency after continuous illumination for 560 h.Additionally,a PCE of 21.6%was achieved in devices with a bandgap of 1.68 eV,which were further extended to perovskite/silicon tandem devices,achieving high-performance devices with PCEs of 30.96%(aperture area:1.05 cm^(2))and 25.96%(aperture area:20.06 cm^(2)).展开更多
The presence of alkaline earth metal ions in biodiesel can exacerbate engine wear,impair fuel oxidation stability,and substantially reduce combustion efficiency.Improving the quality of biodiesel is therefore crucial ...The presence of alkaline earth metal ions in biodiesel can exacerbate engine wear,impair fuel oxidation stability,and substantially reduce combustion efficiency.Improving the quality of biodiesel is therefore crucial for promoting its adoption as a viable alternative to conventional fossil fuels.This study investigates the removal of alkaline earth metal calcium(Ca^(2+))and magnesium(Mg^(2+))from Jatropha biodiesel using four amino polycarboxylate chelating agents:ethylenediaminetetraacetic acid(EDTA),diethylenetriaminepentaacetic acid(DTPA),1,2-cyclohexanediaminetetraacetic acid(CDTA),and N-(2-hydroxyethyl)-ethylenediaminetriacetic acid(HEDTA).The results showed that CDTA demonstrated the highest removal efficiency and selectivity for Ca^(2+)and Mg^(2+)among the four chelating agents,resulting in removal rates of 98.6%and 94.3%,respectively.Furthermore,the oxidative stability of biodiesel,measured as induction period,increased from 3.38 to 8.31 h after treatment with EDTA solution and reached a maximum of 8.68 h after treatment with CDTA.Density functional theory(DFT)calculations were performed to analyze Mulliken charges,electrostatic potential,frontier molecular orbitals,and interaction energies.The results indicate that the four chelating agents form cyclic structure complexes by simultaneously coordinating with a metal ion through multiple coordination atoms(N atom in amino group and O atom in carboxyl group).CDTA has the strongest interaction energies with Ca^(2+)and Mg^(2+),calculated at–826 and–915 kcal/mol,respectively,corroborating its superior chelation performance.展开更多
Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymati...Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymatic hydrolysis,determined peptide sequences with high activity,and analyzed their digestive characteristics and stability.The enzymatic hydrolysis process was optimized using response surface methodology to determine the optimal enzymatic hydrolysis conditions of temperature 55?C,p H 8.5,and the ratio of alkaline protease to flavor protease(proportion of enzymes)2.63:1 under a liquid-to-solid ratio of 20:1.The calcium chelation rate of gluten hydrolysate was up to 40.1%under the optimal conditions.Fractional purification was then carried out and results showed that peptides with a molecular weight below 500 Da exhibited the highest chelation rate(51.1%).LC-MS/MS analysis was applied to identify 1224 distinct peptide sequences,among which V.YIPPY?C(WCP1)exhibited a higher calcium chelation rate after screening and molecular docking studies.The synthesized WCP1 displayed a calcium chelation rate as high as 53.5%.Fourier Transform Infrared Spectroscopy(FTIR)confirmed that both carboxyl and phosphate groups play crucial roles in mediating interactions between calcium ions and wheat polypeptides.Circular Dichroism(CD)revealed that the structure of wheat peptide became more compact after chelation.Furthermore,stability experiments indicated that the calcium-chelating peptides displayed notable resistance to digestion as well as excellent p H stability and thermal stability.This study provides technical support for deep processing and functional product development of gluten flour.展开更多
In-situ growth of layered double hydroxide(LDH)has been considered a feasible method to further improve the corrosion protection of PEO coated Mg alloys,but the process is basically carried out in an autoclave.In this...In-situ growth of layered double hydroxide(LDH)has been considered a feasible method to further improve the corrosion protection of PEO coated Mg alloys,but the process is basically carried out in an autoclave.In this study,LDH was in-situ synthesized on PEO treated AM50 Mg by hydrothermal treatment at ambient pressure in the presence of chelating agents.Results indicated that the synergistic effect of sulfosalicylic acid(SSA)and ethylenediaminetetraacetic acid tetrasodium salt(EDTA)chelating agents is appropriate for Mg-Al LDH formation due to the sufficient quantity of highly stable Mg and Al complexes in the treatment bath.An appropriate hydrothermal treatment time was also revealed in this work,which can efficiently seal the pores and defects of PEO coating with a uniform LDH film.As a result,the corrosion protection of the coating was improved dramatically.The prolonged hydrothermal treatment is detrimental to the integrity of PEO layers.The influence of chelating agents on the LDH formation processes is supported by thermodynamic calculation of the equilibrium composition,and the formation mechanism of LDH film is discussed in depth.展开更多
Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation ...Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation caused by interactions with multivalent metal ions.Chelating agents were introduced into oilfields for various purposes due to their ability to sequester metal ions.In this work,we conducted a comprehensive investigation about chelating agent-surfactant(CS) flooding for carbonate reservoirs,as an alternative to the well-established alkaline surfactant(AS) flooding used in sandstone.The tested surfactants include sodium dodecyl sulfate(anionic)(SDS),dodecyltrimethylammonium bromide(cationic)(DTAB),Triton X100(nonionic),and a locally synthesized zwitterionic surfactant.The tested chelating agents include diethylenetriaminepentaacetic acid(DTPA),ethylenediaminetetraacetic acid,and glutamic acid N,N-diacetic acid.pH and temperature,as dominant factors in chelating agent solubility and brine stability,were modified to test chelating agent solutions of different concentrations and their mixtures with surfactants.Interfacial tension reduction by chelating agents alone,surfactants alone,and their mixtures were measured.Wettability alteration brought by chelating agents and surfactants on carbonate rock surfaces was evaluated using the static contact angle method.Based on the obtained results,chelating agents can be applied as low-cost additives for surfactant stabilization in high salinity conditions.The addition of chelating agents significantly improved the stability of SDS and DTAB in salt solutions and seawater.At a relatively low concentration(0.25 wt%),DTPA was able to stabilize DTAB of 1.00 wt% in seawater at high temperature(90℃).DTPA,among the tested three chelating agents,exhibited a stronger stabilization effect on surfactants of different ion types.When chelating agents are to be applied in brine,an optimal applicable pH range of 5-9 is recommended so not to induce solubility issue of chelating agents or stability issues of metal ions.In this range,IFT reduction is more significant at high pH,while wettability alteration is more significant at low pH.The combination of a cationic surfactant with a chelating agent forms a low adsorption wettability modifier which can change strongly oil-wet rock to water-wet conditions,thus significantly increasing the residual oil recovery from oil-wet carbonate formations.Zwitterionic and nonionic surfactants are also applicable to combine with a chelating agent for EOR purposes.Anionic surfactant SDS,however,showed a growing inhibition on the wettability alteration effect induced by EDTA as the concentration of SDS increased.展开更多
Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from ...Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from the cathodes of EoL lithium-titanate batteries using ethylenediaminetetraacetic acid disodium(EDTA-2Na).In this work,an orthogonal array was used to design experiments and sig-nal-to-noise calculations were used to define the optimal conditions,which were 0.50 mol/L EDTA-2Na,pH=6,75℃,180 min,2%pulp density,and 300 r/min,resulting in 97.96%,94.79%,96.45%,and 98.89%leaching efficiencies for Li,Ni,Co,and Mn,respectively.Stat-istically significant interactions between variables were then identified using Pearson’s correlation at the 95%confidence interval,and the pH and temperature were found to be significant.The extraction efficiency decreased as the pH increased,but increased as the temperat-ure increased.Machine learning fitting using linear regression for multi-output prediction was unsatisfactory,whereas random forest re-gression(RFR)produced satisfactory results.Permutation importance was computed on the fitted RFR to determine feature importance,and confirmed that the pH and temperature were influential variables;however,the time and pulp density were also noted.As the fitted RFR failed to satisfactorily predict leaching efficiencies in additional validation experiments,we recommend increasing the number of ex-periments and using additional fitting models.An additional analysis that included the initial oxidation-reduction potential(optimal 33.3 mV)revealed this to be the most important variable,the effect of which largely overshadows those of all the other variables.Finally,an environmental assessment highlighted the benefits of the chelating extraction;however,the economic assessment indicated room for improvement.展开更多
Because of tempting magnetic-dielectric synergies and interfacial effects,designing a simple and low-cost route for producing multidimensional carbon-based magnetic nanocomposites is very important for the development...Because of tempting magnetic-dielectric synergies and interfacial effects,designing a simple and low-cost route for producing multidimensional carbon-based magnetic nanocomposites is very important for the development of microwave absorbers(MAs).In this paper,a facile and propagable Ni-nitrilotriacetic acid chelate(NAC)derived strategy was proposed to selectively fabricate zero-dimensional(0D)/one-dimensional(1D)porous Ni/C magnetic heterostructured nanorods(MHNRs)consisting of 1D carbon nanorod,lots of pores and 0D Ni nanoparticles via a combined hydrothermal and thermally treated methods.The porous Ni/C MHNRs displayed the progressively improved Ni and C crystallinity by controlling the temperature,which resulted in the tunable electromagnetic and microwave absorption properties(MAPs).Additionally,0D/1D porous CoNi/C and Co/C MHNRs could be selectively produced through this strategy by adopting CoNi-NAC and Co-NAC as precursors.Benefiting from desirable interface and magnetic/dielectric synergies,the acquired 0D/1D porous Ni/C,CoNi/C and Co/C MHNRs presented excellent MAPs and certain corrosion resistance properties.In especial,Co/C MHNRs displayed a strong absorption capacity(−47.89 dB),an ultrawide effective absorption bandwidth(8.40 GHz)and small matching thicknesses(∼2 mm),which were a desirable candidate for MAs.Consequently,a facile,low-cost and propagable metal-NAC derived strategy was proposed to synthesize 0D/1D porous carbon-based MHNRs,which presented an alternative technique to develop lightweight efficient MAs.展开更多
The Li3V2（PO4）3/C composite cathode material was synthesized via sol-gel method using three different chelating agents （citric acid, salicylic acid and polyacrylic acid） at pH value of 3 or 7. The crystal structur...The Li3V2（PO4）3/C composite cathode material was synthesized via sol-gel method using three different chelating agents （citric acid, salicylic acid and polyacrylic acid） at pH value of 3 or 7. The crystal structure, morphology, specific surface area and electrochemical performance of the prepared samples were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and galvanostatic charge/discharge test. The results show that the effects of pH value on the performance of the prepared materials are greatly related to the chelating agents. With salicylic acid or polyacrylic acid as the chelating reagent, the structure, morphology and electrochemical performance of the samples are greatly influenced by the pH values. However, the structure of the materials with citric acid as the chelating agent does not change as pH value changes, and the materials own uniform particle size distribution and good electrochemical performance. It delivers an initial discharge capacity of 113.58 mA·h/g at 10C, remaining as high as 108.48 mA·h/g after 900 cycles, with a capacity retention of 95.51%.展开更多
Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface...Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.展开更多
This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instan...This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.展开更多
[Objective] To explore a high efficient phytoremediation technology for soil pollution. [Method] Foliage application and root irrigation were carried out to study the influence on amaranth repair efficiency by using c...[Objective] To explore a high efficient phytoremediation technology for soil pollution. [Method] Foliage application and root irrigation were carried out to study the influence on amaranth repair efficiency by using combined treatments of phytohor- mones （IAA, GA3 SA） and chelating agents （EDTA）. [Result] The combined treatment increased the biomass of amaranth under 133Cs, 88Sr, Cr stress The 133Cs, 88Sr, Cr enrich- ment in amaranth by root irrigation were obviously higher than that by foliage appli- cation. The phytoextraction efficiency of phytohormones and chelating agents from best to poor was as following： 100 mg/L SA＋1.5 mg/kg EDTA, 500 mg/L GA3＋1.5 mg/kg EDTA, 100 mg/L IAA＋1.5 mg/kg EDTA. [Conclusion] The most appropriate treatment was the combined treatment of 100 mg/L SA＋l.5mg/kg EDTA by soil irri- gation, which could make the total absorption doses of 133Cs, 88Sr, Cr per plant achieve the maximum.展开更多
Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice....Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice.Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1|50 mg/(kg·day)| for 6 months.Blood levels of non-transferrin hound iron,labile plasma iron.ferritin(Ft) and malondialdehyde were determined.Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload.Interestingly,the mice showed a decrease in the non—transferrin bound iron,labile plasma iron and malondialdehyde levels,but not the Ft levels after continuous CM1 treatment.Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overload β—thalassemic mice.展开更多
Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work inves...Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work investigates on PFP for the degradation of CIP to understand the formation mechanism and stability of iron complexes under ultraviolet(UV)-light illumination.A comparison was made with the UV-photocatalysis(UV/TiO_2)process where CIP doesn't form a complex.In PFP,the optimal dose of Fe^(2+)and H_2O_2were found to be 1.25 and10 mmol/L with pH of 3.5.An optimal TiO_2dose of 1.25 g/L was determined in the UV/TiO_2process.Maximum CIP removal and mineralization efficiency of 93.1%and 47.3%were obtained in PFP against 69.7%and 27.6%in the UV/TiO_2process.The mass spectra could identify seventeen intermediate products including iron-CIP complexes in PFP,and only seven intermediate products were found in the UV/TiO_2process with a majority of common products in both the processes.The proposed mechanism supported by the mass spectra bridged the routes of CIP cleavage in the PFP and UV/TiO_2process,and the decomposition pathway of Fe^(3+)-CIP chelate complexes in PFP was also elucidated.Both in PFP and UV/TiO_2processes,the target site of HO~·radical attack was the secondary-N atom present in the piperazine ring of the CIP molecule.The death of Escherichia coli bacteria was 55.7%and 66.8%in comparison to the control media after 45 min of treatment in PFP and UV/TiO_2process,respectively.展开更多
Background： The goal of this study was to compare the antagonism of elevated dietary Cu （250 mg/kg） from CuS04 on three different Zn sources （ZnS04. H20; [Zn bis（-2-hydroxy-4-（methylthio）butanoic acid）], Zn（H...Background： The goal of this study was to compare the antagonism of elevated dietary Cu （250 mg/kg） from CuS04 on three different Zn sources （ZnS04. H20; [Zn bis（-2-hydroxy-4-（methylthio）butanoic acid）], Zn（HMTBa）2 a chelated Zn methionine hydroxy analogue; and Zn-Methionine）, as measured using multiple indices of animal performance in ROSS 308 broilers. Methods： Three experiments were conducted in broiler chicks fed a semi-purified diet. All birds were fed a Zn-deficient diet （8.5 mg/kg diet） for 1 wk, and then provided with the experimental diets for 2 wks. Results： Experiment 1 was a 2 x 2 factorial design with two levels of Cu （8 vs. 250 mg/kg diet from CuSO4） and two Zn sources at 30 mg/kg [ZnSO4. H20 vs. Zn（HMTBa）2]. Elevated Cu impaired growth performance only in birds fed ZnSO4. Compared to ZnSO4. H20, Zn（HMTBa）2 improved feed intake （12 %; P 〈 0.001） and weight gain （12 %, P 〈 0.001） and the benefits were more pronounced in the presence of 250 mg/kg diet Cu. Experiment 2 was a dose titration of ZnSO4- H20 and Zn（HMTBa）2 at 30, 4,5, 60, and 75 mg/kg diet in the presence of 250 mg/kg CuSO4. Feed：gain was decreased and tibia Zn was increased with increasing Zn levels from 30 to 75 mg/kg. Birds fed Zn（HMTBa）2 consumed more food and gained more weight compared to birds fed ZnSO4, especially at lower supplementation levels （30 and 45 mg/kg; interaction P 〈 0,05）. Experiment 3 compared two organic Zn sources （Zn（HMTBa）2 vs. Zn-Methionine） at 30 mg/kg with or without 250 mg/kg CuSO4. No interactions were observed between Zn sources and Cu levels on performance or tissue mineral concentrations. High dietary Cu decreased weight gain （P 〈 0.01）. Tibia Cu and liver Cu were significantly increased with 250 mg/kg dietary Cu supplementation （P 〈 0.01）. No difference was observed between the two Zn sources. Conclusions： Dietary 250 mg/kg Cu significantly impaired feed intake and weight gain in birds fed ZnSO4. H20, but had less impact in birds fed Zn（HMTBa）2. No difference was observed between the two organic zinc sources These results are consistent with the hypothesis that chelated organic Zn is better utilized than inorganic zinc in the presence of elevated Cu.展开更多
Potassium butyl dithiophosphate （PBD） was developed and introduced as a new chelating agent for heavy metal removal. The synthesized PBD were characterized by IR and NMR. The effects of pH, chelating agent dosage, a...Potassium butyl dithiophosphate （PBD） was developed and introduced as a new chelating agent for heavy metal removal. The synthesized PBD were characterized by IR and NMR. The effects of pH, chelating agent dosage, and other heavy metal ions on the performance of PBD in Cd^2＋ removal from water are investigated. Experimental results showed that the chelating agent could be used to treat acidic heavy metal wastewater. The Cd^2＋ removal was not affected by solution pH value within the range of 2 to 6. The Cd^2＋ removal rate could reach over 99%. Therefore, the deficiency of the precipitation process using hydroxide under alkaline condition can be overcome. Without the need for pH adjustment, the method could save on costs. If Cd^2＋ co-exists with Pb^2＋ and Cu^2＋, the affinity of the chelating agent with these three heavy metal ions was in the order of： Cu^2＋ 〉 Pb^2＋ 〉 Cd^2＋. Through PBD chelating precipitation, all the contents of Pb^2＋, Cd^2＋, and Cu^2＋ in wastewater met the standard levels through a one-step treatment. The one-step treatment process was superior to the process （sectional treatment is required） of precipitation with hydroxide. When the pH was between 3 and 11, the amount of leached chelated Cd^2＋ was much lower than that obtained by precipitation with hydroxide. Therefore, the risk of environmental pollution could be further reduced.展开更多
The graft copolymerization of acrylic acid（AA） onto polyethylene glycol terephthalate（PET） fiber initiated by benzoy peroxide （BPO） was carried out in heterogeneous media.Moreover,modification of the grafted PET...The graft copolymerization of acrylic acid（AA） onto polyethylene glycol terephthalate（PET） fiber initiated by benzoy peroxide （BPO） was carried out in heterogeneous media.Moreover,modification of the grafted PET fiber（PET-AA） was done by changing the carboxyl group into acylamino and amino groups through the reaction with ethylenediamine.The new modified chelating fiber （NDWJN6） was characterized using elementary analysis,SEM and FT-IR spectroscopy.Adsorption kinetic curve indicated that NDWJN6 could fastly remove Pb^（2＋） from water,and adsorption isotherm also indicated that NDWJN6 had high equilibrium adsorption capacity for Pb^（2＋）.展开更多
A series of novel chelating fibers containing sulfur, nitrogen, oxygen heteroatoms were prepared via the functionalization of chloromethylated polyphenylene sulfide （CMPPS）. The structures, micromorpholo- gy and phy...A series of novel chelating fibers containing sulfur, nitrogen, oxygen heteroatoms were prepared via the functionalization of chloromethylated polyphenylene sulfide （CMPPS）. The structures, micromorpholo- gy and physicochemical properties of these fibrous adsorptive materials were characterized by FT-IR, elementary analysis, TG and SEM-EDS. The results show that chelating fibers had high functional group contents （3.94 mmol/g for thiourea, 3.85 mmol/g for mercapto, 5.00 mmol/g for methylamine and 6.07 mmol/g for ethylenediamine, respectively）. Owing to the unique matrix of polyphenylene sulfide fiber, these fibrous adsorbents possess excellent thermostability. This synthetic method proved a simple and efficient way for the preparation of chelating fibers.展开更多
文摘The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays an important role in the central nervous system, where it is associated with glutamatergic signaling, and it is widely involved in inflammatory processes. Thus, diseases involving copper(Ⅱ) dyshomeostasis often have neurological symptoms, as exemplified by Alzheimer's and other diseases(such as Parkinson's and Wilson's diseases). Moreover, imbalanced copper ion concentrations have also been associated with diabetes and certain types of cancer, including glioma. In this paper, we propose a comprehensive overview of recent results that show the importance of these metal ions in several pathologies, mainly Alzheimer's disease, through the lens of the development and use of copper chelators as research compounds and potential therapeutics if included in multi-target hybrid drugs. Seeing how copper homeostasis is important for the well-being of animals as well as humans, we shortly describe the state of the art regarding the effects of copper and its chelators in agriculture, livestock rearing, and aquaculture, as ingredients for the formulation of feed supplements as well as to prevent the effects of pollution on animal productions.
基金Project(52174239)supported by the National Natural Science Foundation of ChinaProject(2021YFC2902400)supported by the National Key R&D Program of China。
文摘The chemical composition of seawater affects the desulfurization of chalcopyrite in flotation.In this study,desulfurization experiments of chalcopyrite were conducted in both deionized(DI)water and seawater.The results showed that,the copper grade of the concentrate obtained from seawater flotation decreased to 24.30%,compared to 24.60%in DI water.Concurrently,the recovery of chalcopyrite decreased from 51.39%to 38.67%,while the selectivity index(SI)also had a reduction from 2.006 to 1.798.The incorporation of ethylene diamine tetraacetic acid(EDTA),sodium silicate(SS),and sodium hexametaphosphate(SHMP)yielded an enhancement in the SI value,elevating it from 1.798 to 1.897,2.250 and 2.153,separately.It is particularly noteworthy that an excess of EDTA resulted in a SI value of merely 1.831.The mechanism of action was elucidated through analysis of surface charge measurements,X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR),extended Derjaguin-Landau Verwey-Overbeek(E-DLVO)theory,and density functional theory(DFT)calculations.
基金Supported by the Joint Funds of the National Natural Science Foundation of China(U2340219)。
文摘Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.
基金the generous financial support provided by Sichuan Science and Technology Program(2024ZDZX0030)Chengdu Science and Technology Program(2024-JB00-00010-GX)。
文摘During the crystallization of perovskite films,defects at Pb and I sites are generated,causing lattice mismatch and adversely affecting the performance of perovskite solar cells(PSCs).Herein,we introduced aπ-conjugated molecule with a dual-ring structure,namely CCA(3,4-ethylenedioxythiophene-2,5-dicarboxylic acid),as an additive to regulate the crystallization of perovskite films and passivate defects.As a bidentate Lewis base,CCA coordinates the bidentate carboxyl groups with free Pb^(2+)through the delocalized electrons of its conjugated ring.This coordination regulates lattice stress,repairs the 3D[PbI6]octahedra,stabilizes the perovskite framework,and guides the vertical orientation growth of grains.Simultaneously,the addition of CCA shifts the perovskite’s band structure towards p-type,achieving better energy-level alignment with the doped hole-transport layer(HTL)and suppressing non-radiative recombination.Consequently,the prepared CCA-doped single-junction devices exhibit an outstanding power conversion efficiency(PCE)of 24.90%,with a high open-circuit voltage(VOC)of 1.195,a high fill factor(FF)of 84.60%,and low FF loss.The optimized films and devices show enhanced long-term stability,retaining 80.1%of the initial efficiency after continuous illumination for 560 h.Additionally,a PCE of 21.6%was achieved in devices with a bandgap of 1.68 eV,which were further extended to perovskite/silicon tandem devices,achieving high-performance devices with PCEs of 30.96%(aperture area:1.05 cm^(2))and 25.96%(aperture area:20.06 cm^(2)).
基金supported by Yunnan Fundamental Research Projects,China(Grant No.202201AS070036)the National Natural Science Foundation of China(Grant No.52166013)+1 种基金Major Science and Technology Project of Yunnan Province,China(Grant Nos.202302AF080005,202302AG050011,202302AQ370003)Technology Talent and Platform Plan of Yunnan Province,China(Grant No.202305AS350016).
文摘The presence of alkaline earth metal ions in biodiesel can exacerbate engine wear,impair fuel oxidation stability,and substantially reduce combustion efficiency.Improving the quality of biodiesel is therefore crucial for promoting its adoption as a viable alternative to conventional fossil fuels.This study investigates the removal of alkaline earth metal calcium(Ca^(2+))and magnesium(Mg^(2+))from Jatropha biodiesel using four amino polycarboxylate chelating agents:ethylenediaminetetraacetic acid(EDTA),diethylenetriaminepentaacetic acid(DTPA),1,2-cyclohexanediaminetetraacetic acid(CDTA),and N-(2-hydroxyethyl)-ethylenediaminetriacetic acid(HEDTA).The results showed that CDTA demonstrated the highest removal efficiency and selectivity for Ca^(2+)and Mg^(2+)among the four chelating agents,resulting in removal rates of 98.6%and 94.3%,respectively.Furthermore,the oxidative stability of biodiesel,measured as induction period,increased from 3.38 to 8.31 h after treatment with EDTA solution and reached a maximum of 8.68 h after treatment with CDTA.Density functional theory(DFT)calculations were performed to analyze Mulliken charges,electrostatic potential,frontier molecular orbitals,and interaction energies.The results indicate that the four chelating agents form cyclic structure complexes by simultaneously coordinating with a metal ion through multiple coordination atoms(N atom in amino group and O atom in carboxyl group).CDTA has the strongest interaction energies with Ca^(2+)and Mg^(2+),calculated at–826 and–915 kcal/mol,respectively,corroborating its superior chelation performance.
基金Innovation Ability Improvement Project of Science and Technology Small and Medium-sized Enterprises in Shandong Province:2023TSGC0892,2022TSGC2520Project supported by Qingdao Natural Science Foundation:23-2-1-180-zyyd-jch+3 种基金Key R&D Program of Shandong Province,China:2023TZXD078Shandong Province Technology Innovation Guidance Plan:YDZX2023035Qingdao People’s Livelihood Science and Technology Plan Project:23-2-8-xdny-6-nsh,23-3-8-xdny-1-nshThe Two Hundred Talents Project of Yantai City in 2020。
文摘Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymatic hydrolysis,determined peptide sequences with high activity,and analyzed their digestive characteristics and stability.The enzymatic hydrolysis process was optimized using response surface methodology to determine the optimal enzymatic hydrolysis conditions of temperature 55?C,p H 8.5,and the ratio of alkaline protease to flavor protease(proportion of enzymes)2.63:1 under a liquid-to-solid ratio of 20:1.The calcium chelation rate of gluten hydrolysate was up to 40.1%under the optimal conditions.Fractional purification was then carried out and results showed that peptides with a molecular weight below 500 Da exhibited the highest chelation rate(51.1%).LC-MS/MS analysis was applied to identify 1224 distinct peptide sequences,among which V.YIPPY?C(WCP1)exhibited a higher calcium chelation rate after screening and molecular docking studies.The synthesized WCP1 displayed a calcium chelation rate as high as 53.5%.Fourier Transform Infrared Spectroscopy(FTIR)confirmed that both carboxyl and phosphate groups play crucial roles in mediating interactions between calcium ions and wheat polypeptides.Circular Dichroism(CD)revealed that the structure of wheat peptide became more compact after chelation.Furthermore,stability experiments indicated that the calcium-chelating peptides displayed notable resistance to digestion as well as excellent p H stability and thermal stability.This study provides technical support for deep processing and functional product development of gluten flour.
基金the financial support from National Natural Science Foundation of China(No.52071067)Mobility Programme of the Sino-German Center(M-0056)+3 种基金Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(RC231178)Natural Science Foundation Project of Liaoning Province(2022-YGJC-16)the Fundamental Research Funds for the Central Universities(N2302019)Qianqian Chen would like to acknowledge China Scholarship Council for the award of fellowship(NO.202206080011).
文摘In-situ growth of layered double hydroxide(LDH)has been considered a feasible method to further improve the corrosion protection of PEO coated Mg alloys,but the process is basically carried out in an autoclave.In this study,LDH was in-situ synthesized on PEO treated AM50 Mg by hydrothermal treatment at ambient pressure in the presence of chelating agents.Results indicated that the synergistic effect of sulfosalicylic acid(SSA)and ethylenediaminetetraacetic acid tetrasodium salt(EDTA)chelating agents is appropriate for Mg-Al LDH formation due to the sufficient quantity of highly stable Mg and Al complexes in the treatment bath.An appropriate hydrothermal treatment time was also revealed in this work,which can efficiently seal the pores and defects of PEO coating with a uniform LDH film.As a result,the corrosion protection of the coating was improved dramatically.The prolonged hydrothermal treatment is detrimental to the integrity of PEO layers.The influence of chelating agents on the LDH formation processes is supported by thermodynamic calculation of the equilibrium composition,and the formation mechanism of LDH film is discussed in depth.
基金supported by the College of Petroleum Engineering&Geoscience (CPG) at King Fahd University of Petroleum and Minerals (KFUPM)。
文摘Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation caused by interactions with multivalent metal ions.Chelating agents were introduced into oilfields for various purposes due to their ability to sequester metal ions.In this work,we conducted a comprehensive investigation about chelating agent-surfactant(CS) flooding for carbonate reservoirs,as an alternative to the well-established alkaline surfactant(AS) flooding used in sandstone.The tested surfactants include sodium dodecyl sulfate(anionic)(SDS),dodecyltrimethylammonium bromide(cationic)(DTAB),Triton X100(nonionic),and a locally synthesized zwitterionic surfactant.The tested chelating agents include diethylenetriaminepentaacetic acid(DTPA),ethylenediaminetetraacetic acid,and glutamic acid N,N-diacetic acid.pH and temperature,as dominant factors in chelating agent solubility and brine stability,were modified to test chelating agent solutions of different concentrations and their mixtures with surfactants.Interfacial tension reduction by chelating agents alone,surfactants alone,and their mixtures were measured.Wettability alteration brought by chelating agents and surfactants on carbonate rock surfaces was evaluated using the static contact angle method.Based on the obtained results,chelating agents can be applied as low-cost additives for surfactant stabilization in high salinity conditions.The addition of chelating agents significantly improved the stability of SDS and DTAB in salt solutions and seawater.At a relatively low concentration(0.25 wt%),DTPA was able to stabilize DTAB of 1.00 wt% in seawater at high temperature(90℃).DTPA,among the tested three chelating agents,exhibited a stronger stabilization effect on surfactants of different ion types.When chelating agents are to be applied in brine,an optimal applicable pH range of 5-9 is recommended so not to induce solubility issue of chelating agents or stability issues of metal ions.In this range,IFT reduction is more significant at high pH,while wettability alteration is more significant at low pH.The combination of a cationic surfactant with a chelating agent forms a low adsorption wettability modifier which can change strongly oil-wet rock to water-wet conditions,thus significantly increasing the residual oil recovery from oil-wet carbonate formations.Zwitterionic and nonionic surfactants are also applicable to combine with a chelating agent for EOR purposes.Anionic surfactant SDS,however,showed a growing inhibition on the wettability alteration effect induced by EDTA as the concentration of SDS increased.
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(Nos.RS-2024-00406500 and RS-2024-00458682).
文摘Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from the cathodes of EoL lithium-titanate batteries using ethylenediaminetetraacetic acid disodium(EDTA-2Na).In this work,an orthogonal array was used to design experiments and sig-nal-to-noise calculations were used to define the optimal conditions,which were 0.50 mol/L EDTA-2Na,pH=6,75℃,180 min,2%pulp density,and 300 r/min,resulting in 97.96%,94.79%,96.45%,and 98.89%leaching efficiencies for Li,Ni,Co,and Mn,respectively.Stat-istically significant interactions between variables were then identified using Pearson’s correlation at the 95%confidence interval,and the pH and temperature were found to be significant.The extraction efficiency decreased as the pH increased,but increased as the temperat-ure increased.Machine learning fitting using linear regression for multi-output prediction was unsatisfactory,whereas random forest re-gression(RFR)produced satisfactory results.Permutation importance was computed on the fitted RFR to determine feature importance,and confirmed that the pH and temperature were influential variables;however,the time and pulp density were also noted.As the fitted RFR failed to satisfactorily predict leaching efficiencies in additional validation experiments,we recommend increasing the number of ex-periments and using additional fitting models.An additional analysis that included the initial oxidation-reduction potential(optimal 33.3 mV)revealed this to be the most important variable,the effect of which largely overshadows those of all the other variables.Finally,an environmental assessment highlighted the benefits of the chelating extraction;however,the economic assessment indicated room for improvement.
基金financially supported by the National Natural Science Foundation of China(No.62105076)the Innovation Group of Guizhou University(No.[2024]08)+2 种基金the Platform of Science and Technology and Talent Team Plan of Guizhou Province(No.GCC[2023]007)the Guizhou Provincial Basic Research Program(No.ZK[2021]327)the Fok Ying Tung Education Foundation(No.171095)。
文摘Because of tempting magnetic-dielectric synergies and interfacial effects,designing a simple and low-cost route for producing multidimensional carbon-based magnetic nanocomposites is very important for the development of microwave absorbers(MAs).In this paper,a facile and propagable Ni-nitrilotriacetic acid chelate(NAC)derived strategy was proposed to selectively fabricate zero-dimensional(0D)/one-dimensional(1D)porous Ni/C magnetic heterostructured nanorods(MHNRs)consisting of 1D carbon nanorod,lots of pores and 0D Ni nanoparticles via a combined hydrothermal and thermally treated methods.The porous Ni/C MHNRs displayed the progressively improved Ni and C crystallinity by controlling the temperature,which resulted in the tunable electromagnetic and microwave absorption properties(MAPs).Additionally,0D/1D porous CoNi/C and Co/C MHNRs could be selectively produced through this strategy by adopting CoNi-NAC and Co-NAC as precursors.Benefiting from desirable interface and magnetic/dielectric synergies,the acquired 0D/1D porous Ni/C,CoNi/C and Co/C MHNRs presented excellent MAPs and certain corrosion resistance properties.In especial,Co/C MHNRs displayed a strong absorption capacity(−47.89 dB),an ultrawide effective absorption bandwidth(8.40 GHz)and small matching thicknesses(∼2 mm),which were a desirable candidate for MAs.Consequently,a facile,low-cost and propagable metal-NAC derived strategy was proposed to synthesize 0D/1D porous carbon-based MHNRs,which presented an alternative technique to develop lightweight efficient MAs.
基金Project(2007BAQ01055)supported by the National Key Technology R&D Program of ChinaProject(2011SCU11081)supported by the Sichuan University Funds for Young Scientists,ChinaProject(20120181120103)supported by Ph.D.Programs Foundation of the Ministry of Education of China
文摘The Li3V2（PO4）3/C composite cathode material was synthesized via sol-gel method using three different chelating agents （citric acid, salicylic acid and polyacrylic acid） at pH value of 3 or 7. The crystal structure, morphology, specific surface area and electrochemical performance of the prepared samples were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and galvanostatic charge/discharge test. The results show that the effects of pH value on the performance of the prepared materials are greatly related to the chelating agents. With salicylic acid or polyacrylic acid as the chelating reagent, the structure, morphology and electrochemical performance of the samples are greatly influenced by the pH values. However, the structure of the materials with citric acid as the chelating agent does not change as pH value changes, and the materials own uniform particle size distribution and good electrochemical performance. It delivers an initial discharge capacity of 113.58 mA·h/g at 10C, remaining as high as 108.48 mA·h/g after 900 cycles, with a capacity retention of 95.51%.
文摘Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.
基金granted by the National Key R&D Program of China (2021YFD21001005)National Natural Science Foundation of China (31972102,32101980)+1 种基金Special key project of Chongqing technology innovation and application development (cstc2021jscx-cylhX0014)Chongqing Technology Innovation and Application Development Special Project (cstc2021jscx-tpyzxX0014)。
文摘This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.
基金Supported by the Plan for the National Defense Basic Scientific Research of the State Administration of ScienceTechnology and Industry for National Defense of China(b312011)~~
文摘[Objective] To explore a high efficient phytoremediation technology for soil pollution. [Method] Foliage application and root irrigation were carried out to study the influence on amaranth repair efficiency by using combined treatments of phytohor- mones （IAA, GA3 SA） and chelating agents （EDTA）. [Result] The combined treatment increased the biomass of amaranth under 133Cs, 88Sr, Cr stress The 133Cs, 88Sr, Cr enrich- ment in amaranth by root irrigation were obviously higher than that by foliage appli- cation. The phytoextraction efficiency of phytohormones and chelating agents from best to poor was as following： 100 mg/L SA＋1.5 mg/kg EDTA, 500 mg/L GA3＋1.5 mg/kg EDTA, 100 mg/L IAA＋1.5 mg/kg EDTA. [Conclusion] The most appropriate treatment was the combined treatment of 100 mg/L SA＋l.5mg/kg EDTA by soil irri- gation, which could make the total absorption doses of 133Cs, 88Sr, Cr per plant achieve the maximum.
基金Supported by the Royal Golden Jubilee PhD Program.Thailand Research Fund(Grant No.PHD/0333/2551)
文摘Objective:To evaluate the iron—chelating properties and free—radical scavenging activities of1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methyIpyridin—4-one(CM1) treatment in chronic iron-loaded β-thalassemic(BKO) mice.Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1|50 mg/(kg·day)| for 6 months.Blood levels of non-transferrin hound iron,labile plasma iron.ferritin(Ft) and malondialdehyde were determined.Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload.Interestingly,the mice showed a decrease in the non—transferrin bound iron,labile plasma iron and malondialdehyde levels,but not the Ft levels after continuous CM1 treatment.Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overload β—thalassemic mice.
基金supported by the Indian Institute of Guwahati (India), for providing the research fellowship to Mr. Ardhendu Sekhar Giri
文摘Ciprofloxacin(CIP)is a broad spectrum synthetic antibiotic drug of fluoroquinolones class.CIP can act as a bidentate ligand forming iron complexes during its degradation in the photoFenton process(PFP).This work investigates on PFP for the degradation of CIP to understand the formation mechanism and stability of iron complexes under ultraviolet(UV)-light illumination.A comparison was made with the UV-photocatalysis(UV/TiO_2)process where CIP doesn't form a complex.In PFP,the optimal dose of Fe^(2+)and H_2O_2were found to be 1.25 and10 mmol/L with pH of 3.5.An optimal TiO_2dose of 1.25 g/L was determined in the UV/TiO_2process.Maximum CIP removal and mineralization efficiency of 93.1%and 47.3%were obtained in PFP against 69.7%and 27.6%in the UV/TiO_2process.The mass spectra could identify seventeen intermediate products including iron-CIP complexes in PFP,and only seven intermediate products were found in the UV/TiO_2process with a majority of common products in both the processes.The proposed mechanism supported by the mass spectra bridged the routes of CIP cleavage in the PFP and UV/TiO_2process,and the decomposition pathway of Fe^(3+)-CIP chelate complexes in PFP was also elucidated.Both in PFP and UV/TiO_2processes,the target site of HO~·radical attack was the secondary-N atom present in the piperazine ring of the CIP molecule.The death of Escherichia coli bacteria was 55.7%and 66.8%in comparison to the control media after 45 min of treatment in PFP and UV/TiO_2process,respectively.
文摘Background： The goal of this study was to compare the antagonism of elevated dietary Cu （250 mg/kg） from CuS04 on three different Zn sources （ZnS04. H20; [Zn bis（-2-hydroxy-4-（methylthio）butanoic acid）], Zn（HMTBa）2 a chelated Zn methionine hydroxy analogue; and Zn-Methionine）, as measured using multiple indices of animal performance in ROSS 308 broilers. Methods： Three experiments were conducted in broiler chicks fed a semi-purified diet. All birds were fed a Zn-deficient diet （8.5 mg/kg diet） for 1 wk, and then provided with the experimental diets for 2 wks. Results： Experiment 1 was a 2 x 2 factorial design with two levels of Cu （8 vs. 250 mg/kg diet from CuSO4） and two Zn sources at 30 mg/kg [ZnSO4. H20 vs. Zn（HMTBa）2]. Elevated Cu impaired growth performance only in birds fed ZnSO4. Compared to ZnSO4. H20, Zn（HMTBa）2 improved feed intake （12 %; P 〈 0.001） and weight gain （12 %, P 〈 0.001） and the benefits were more pronounced in the presence of 250 mg/kg diet Cu. Experiment 2 was a dose titration of ZnSO4- H20 and Zn（HMTBa）2 at 30, 4,5, 60, and 75 mg/kg diet in the presence of 250 mg/kg CuSO4. Feed：gain was decreased and tibia Zn was increased with increasing Zn levels from 30 to 75 mg/kg. Birds fed Zn（HMTBa）2 consumed more food and gained more weight compared to birds fed ZnSO4, especially at lower supplementation levels （30 and 45 mg/kg; interaction P 〈 0,05）. Experiment 3 compared two organic Zn sources （Zn（HMTBa）2 vs. Zn-Methionine） at 30 mg/kg with or without 250 mg/kg CuSO4. No interactions were observed between Zn sources and Cu levels on performance or tissue mineral concentrations. High dietary Cu decreased weight gain （P 〈 0.01）. Tibia Cu and liver Cu were significantly increased with 250 mg/kg dietary Cu supplementation （P 〈 0.01）. No difference was observed between the two Zn sources. Conclusions： Dietary 250 mg/kg Cu significantly impaired feed intake and weight gain in birds fed ZnSO4. H20, but had less impact in birds fed Zn（HMTBa）2. No difference was observed between the two organic zinc sources These results are consistent with the hypothesis that chelated organic Zn is better utilized than inorganic zinc in the presence of elevated Cu.
文摘Potassium butyl dithiophosphate （PBD） was developed and introduced as a new chelating agent for heavy metal removal. The synthesized PBD were characterized by IR and NMR. The effects of pH, chelating agent dosage, and other heavy metal ions on the performance of PBD in Cd^2＋ removal from water are investigated. Experimental results showed that the chelating agent could be used to treat acidic heavy metal wastewater. The Cd^2＋ removal was not affected by solution pH value within the range of 2 to 6. The Cd^2＋ removal rate could reach over 99%. Therefore, the deficiency of the precipitation process using hydroxide under alkaline condition can be overcome. Without the need for pH adjustment, the method could save on costs. If Cd^2＋ co-exists with Pb^2＋ and Cu^2＋, the affinity of the chelating agent with these three heavy metal ions was in the order of： Cu^2＋ 〉 Pb^2＋ 〉 Cd^2＋. Through PBD chelating precipitation, all the contents of Pb^2＋, Cd^2＋, and Cu^2＋ in wastewater met the standard levels through a one-step treatment. The one-step treatment process was superior to the process （sectional treatment is required） of precipitation with hydroxide. When the pH was between 3 and 11, the amount of leached chelated Cd^2＋ was much lower than that obtained by precipitation with hydroxide. Therefore, the risk of environmental pollution could be further reduced.
基金support provided by the National Science Funds for Young Scientists(No. 51008152)the Nature Science Fund of Jiangsu Province(No.BK2010381)the Fundamental Research Funds for the Central Universities
文摘The graft copolymerization of acrylic acid（AA） onto polyethylene glycol terephthalate（PET） fiber initiated by benzoy peroxide （BPO） was carried out in heterogeneous media.Moreover,modification of the grafted PET fiber（PET-AA） was done by changing the carboxyl group into acylamino and amino groups through the reaction with ethylenediamine.The new modified chelating fiber （NDWJN6） was characterized using elementary analysis,SEM and FT-IR spectroscopy.Adsorption kinetic curve indicated that NDWJN6 could fastly remove Pb^（2＋） from water,and adsorption isotherm also indicated that NDWJN6 had high equilibrium adsorption capacity for Pb^（2＋）.
基金support by the National Natural Science Foundation of China(No.20574063)Doctoral Foundation of Ministry of Education of China(No. 20104101110005)
文摘A series of novel chelating fibers containing sulfur, nitrogen, oxygen heteroatoms were prepared via the functionalization of chloromethylated polyphenylene sulfide （CMPPS）. The structures, micromorpholo- gy and physicochemical properties of these fibrous adsorptive materials were characterized by FT-IR, elementary analysis, TG and SEM-EDS. The results show that chelating fibers had high functional group contents （3.94 mmol/g for thiourea, 3.85 mmol/g for mercapto, 5.00 mmol/g for methylamine and 6.07 mmol/g for ethylenediamine, respectively）. Owing to the unique matrix of polyphenylene sulfide fiber, these fibrous adsorbents possess excellent thermostability. This synthetic method proved a simple and efficient way for the preparation of chelating fibers.
