Polarizable Additive with Intermediate Chelation Strength for Stable Aqueous Zinc‑Ion Batteries

Aqueous zinc-ion batteries are promising due to inherent safety,low cost,low toxicity,and high volumetric capacity.However,issues of dendrites and side reactions between zinc metal anode and the electrolyte need to be solved for extended storage and cycle life.Here,we proposed that an electrolyte additive with an intermediate chelation strength of zinc ion—strong enough to exclude water molecules from the zinc metal-electrolyte interface and not too strong to cause a significant energy barrier for zinc ion dissociation—can benefit the electrochemical stability by suppressing hydrogen evolution reaction,overpotential growth,and den-drite formation.Penta-sodium diethylene-triaminepentaacetic acid salt was selected for such a purpose.It has a suitable chelating ability in aqueous solutions to adjust solvation sheath and can be readily polarized under electrical loading conditions to further improve the passivation.Zn||Zn symmetric cells can be stably operated over 3500 h at 1 mA cm^(-2).Zn||NH4V4O10 full cells with the additive show great cycling stability with 84.6%capacity retention after 500 cycles at 1 A g^(-1).Since the additive not only reduces H2 evolution and corrosion but also modifies Zn2+diffusion and deposition,highlyreversible Zn electrodes can be achieved as verified by the experimental results.Our work offers a practical approach to the logical design of reliable electrolytes for high-performance aqueous batteries.

New developments and controversies in iron metabolism and iron chelation therapy

Iron is essential for all organisms including microbial,cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic haemochromatosis, thalassaemia intermedia and ex-thalassaemia transplanted patients who are safely treated with venesection. Iron chelating drugs can override normal regulatory pathways, correct iron imbalance and minimise iron toxicity. The use of iron chelating drugs as main, alternative or adjuvant therapy is in progress in many conditions, especially those with non established or effective therapies.

Chelation of GRP78 with Lead and Its Localization Changes in the Astroglia of Rats Exposed to Lead

To observe the chelation of GRP78 with lead （Pb） and its localization changes, astroglial ceils from Wistar rat brain were primarily cultured in medium witb acetate Pb. The processes were terminated at different time points. The immunoprecipitation （IP） and Western blotting were used for GRP78 purification and expression and the Pb concentration was determined by employing atomic absorption spectrophotometry （AAS）. The localization change of GRP78 was observed with colloid gold immunoelectron microscopy. The results showed that the expression of GRP78 was increased significantly in the cells treated with 1.0 μmol/L acetate Pb for 24 h and peaked at 96-192 h （P〈0.01）, and at the 12th day, the expression of GRP78 began to decrease but was still higher than normal （P〈0.05）. Pb content started to increase when cells were treated by acetate Pb for 24 h, and the peak appeared at 8 day （P〈0.01）, and then Pb content decreased gradually, but was still higher than normal （P〈0.05）. GRP78 protein expression began to remarkably increase when it transferred from ER to the cytosol around the nuclei 24 h after treatment with Pb. It is concluded that GRP78 in astroglia could strongly chelate with Pb ions and it might be a target protein of Pb.

The Mechanism of Sol-Gel Synthesis of Normal Spinel LiMn_2O_4 with Chelation of Citric Acid

The sol-gel process of citric acid chelating with metal cations for the synthesis of normal spinel LiMn 2O 4 and the reaction mechanism were investigated by means of XRD,IR,TG-DTA, and SEM.The results show that at the beginning lithium citrate and chelate compound of citric acid with manganese ions formed,and then with heating the esterification and condensation reactions occured between them and glycol.The products obtained are polymers in which metal cations are distributed homogeneously on atomic scale that ensure high reactivity to cations of Li + and Mn 2+.Firing the gel prepared by this process,the lattice diffusions of solid reactant ions caused by non-homogeneity of reactants are eliminated and avoided.At 400℃ phase-pure LiMn 2O 4 with nanometer scale crystallization having precise stoichiometry and perfect crystallization can be obtained.The model of chelate coordinate of double-molecule between citric acid and Mn 2+ in the gel network is proposed.It is important for explaining the dispersion state of Mn 2+ and the formation process of gel by this model.

Influence of Methionine Supplementation in Chelation of Lead in Rats1

The influence of methionine supplementation on the efficacy of common antidotes to lead poisoning, calcium disodium ethylenediaminetetraacetate (CaNa_2EDTA) and D-penicillamine (DPA), was investigated in rats. The animals were given lead acetate (0.1% in drinking water) for 12 weeks and thereafter treated with CaNa_2EDTA, DPA (0.3mmol/kg, intraperitoneally), DL-methionine (1.34 mmol/kg, intragastrically), or the combination of a chelating agent and methionine for 3 days. While chelating agents enhanced the urinary excretion of Pb, methionine increased the fecal excretion of Pb significantly. Treatment with the combination of a chelating agent and methionine did not potentiate the effect of each antidote. However, methionine supplementation increased the efficacy of both chelating agents in reducing the hepatic and renal Pb burden but not the blood Pb level. The Pb-induced inhibition of blood δ-aminolevulinic acid dehydratase activity and the increase in urinary excretion of δ-aminolevulinic acid were reversed to a certain extent by CaNa_2EDTA, DPA, and methionine but the combination did not improve their individual performances. The beneficial effects of methionine may be attributed to its ability to increase the bioavailability of glutathione (GSH), useful in chelating Pb and counteracting the toxic effects, as evidenced by restoration of the Pb-induced decrease in hepatic GSH level by treatment with methionine. Methionine may be useful as a supportive therapy in chelation of Pb. (c)1989 Academic Press. Inc.

Structure-Activity Relationships in the Chelation Activity by Derivatives of 1,2-Dithiole-3-Thiones

The structure and electronic properties of a series of biologically active dithiolethiones （1） have been calculated using semi-empirical. Multi-linear regression analysis suggests that there is a reasonable correlation between the experimental activity of the derivatives against chelation activity and calculated properties such as the HOMO energies, molar refractivity, dipole moments and experimental partition coefficient. From the derived QSAR equations the 3-Methylthio-4p-Tolyle-1,2-Dithiolylium accompanying ion （CH3SO4） and 4-para-tolyl-1,2-dithiole-3-thione （2b and 2） are predicted to show the highest activity against chelation activity, while 3-Methylthio-5p-methoxy phenyl-1,2-Dithiolylium accompanying ion （I-） （3a） is predicted to be the least active in line with the experimental results.

Chelation Assignments of Ga^Ⅲ,Ge^Ⅳand Si^ⅣMetal Ions WithPipemidic Acid Antibiotic Drug:Synthesis,Spectroscopic Characterizations and Biological Studies

Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity.

Chelation of lithium ion with crown ether for eliminating adverse effects caused by Li-TFSI/tBP doping system in Spiro-OMeTAD

Lithium bis(trifluoromethanesulfonyl)imide(Li-TFSI)/4-tert-butylpyridine(tBP)is a classic doping system for the hole transport material Spiro-OMeTAD in typical n-i-p structure perovskite solar cells(PSCs),but this system will cause many problems such as high hygroscopicity,Li+migration,pinholes and so on,which hinder PSC from maintaining high efficiency and stability for long-term.In this work,an effective strategy is demonstrated to improve the performance and stability of PSC by replacing t BP with 12-crown-4.The chelation of 12-crown-4 with Li+not only improves the doping effect of Li-TFSI,but also perfectly solves the problems caused by the Li-TFSI/tBP system.The PSC based on this strategy achieved a champion power conversion efficiency(PCE)over 21%,which is significantly better than the pristine device(19.37%).More importantly,the without encapsulated device based on Li-TFSI/12-crown-4 still maintains 87%of the initial PCE even after 60 days exposure in air,while the pristine device only maintains 22%of the initial PCE under the same aging conditions.This strategy paves a novel way for constructing efficient and stable PSCs.

Chelation in Metal Intoxication XLVI:Synthesis of Someα-Mercapto-β-Substituted Aryl Acrylic Acids and TheirIn vitro Cadmium Chelating Ability

Objective To synthesize some new a-mercapto-β-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability. Methods Six α-mercapto-β-substituted aryl acrylic acids were prepared by the alkaline hydrolysis of 5- (aryl methylene) rhodanines, obtained from the condensation of substituted aldehydes and rhodanine following the reported procedure. The new compounds were characterized by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The liver and kidney from cadmium chloride pre-administered rats were homogenized and their nuclear mitochondrial fraction (NMF) and supernatant cytosol fraction (SCF) were separated. A measured volume of each fraction was dialyzed separately using 'dialysis sack' against buffered-KCl medium containing a compound in the final concentration of 1×10-3 mol/L for 3 h at 37℃. The whole content of 'sack' was subjected to cadmium estimation following digestion with cone. Nitric acid was detected using flame atomic absorption spectrometer. Results The in vitro screening showed that α-mercapto-β-(p-methoxyphenyl) acrylic acid (compound 2) andα-mercapto-β-(m-methoxy, p-hydroxyphenyl) acrylic acid (compound 4) were more effective than α-mercapto-β-thienyl acrylic acid (compound 1) and a-mercapto-β-(p-dimethylaminophenyl) acrylic acid (compound 3) in mobilizing cadmium as their dialyzable chelates. The presence of a methoxy group on the phenyl moiety (compounds 2 and 4) increases the metal chelating ability of mercapto acrylic acids. Conclusions Compounds 2 and 4 seem to have accessibility to the cellular system and capability of chelating-out the intracellularly bound cadmium.

Chelation in Metal Intoxication XLIV: Efficacy of α-Mercapto β-(5-Substituted, 2-Furyl) Acrylic Acids in Mobilizing Intracellularly Bound Cadmium in Rat

The efficacy of α mercapto β (2_furyl) acrylic acid (MFA), α mercapto β (5_sodiumsulfonate, 2_furyl) acrylic acid (MSFA) and α mercapto β (5_acetoxymethyl, 2_furyl) acrylic acid (MAFA) to mobilize intracellularly bound cadmium in liver and kidney was investigated in rats pre_exposed to cadmium. MFA was effective in reducing cadmium levels of hepatic and renal supernatant cytosolic fraction (SCF) while MSFA and MAFA were effective in lowering cadmium levels of renal SCF and hepatic SCF respectively. All the chelating agents also enhanced the excretion of cadmium more in feces than in urine. However, substitution on the furan ring lowered cadmium mobilizing efficacy of the parent compound, MFA. The treatment with MFA did not affect the status of endogenous zinc and copper while the treatment with MSFA and MAFA enhanced their excretion. MSFA increased hepatic and renal zinc and renal copper while MAFA increased their copper levels.

The Effects of Magnesium-EDTA Chelation Therapy on Arterial Stiffness

Traditional risk factors for cardiovascular disease can only assess risks for groups of people. New parameters of arterial stiffness are more reliable for predicting cardiovascular outcomes for individuals with and without a cardiovascular history. The objective of this study was to assess the effects of Magnesium-EDTA chelation therapy using new methods and parameters such as pulse wave velocity (PWV), central blood pressure (SBPao) and endothelial function (Aix). We followed 43 patients with an abnormal PWV and SBPao, setting them up in two groups. The 21 patients in Group A had already been diagnosed with cardiovascular disease. The other 22 patients in Group B also showed abnormal PWV, SBPao and Aix, but showed no cardiovascular symptoms. Each patient in Groups A and B received one Mg-EDTA treatment per week. The total treatment plan consisted of 25 Mg-EDTA chelation treatments according to the standard protocol of IBCMT. After 25 Mg-EDTA chelation sessions, PWV and SBPao improved significantly in all patients of Groups A and B. In addition, Aix improved significantly in these patients, but remained abnormal. Group C included 18 asymptomatic patients with normal PWV or SBPao. Aix was abnormal in this group, but to a much lesser extent than Groups A and B. The 18 asymptomatic patients of Group C did not receive Mg-EDTA treatment. Observation showed no significant changes in all three parameters of arterial stiffness. The results of this study indicate that a course of treatment with Magnesium-EDTA chelation therapy significantly lowers cardiovascular risks. We conclude that Mg-EDTA chelation therapy improves PWV as an indicator of arterial stiffness, SBPao (central blood pressure) as an indicator of aortic elasticity and Aix (augmented aortic index) as an indicator of endothelial functioning. These improvements in PWV, SBPao and Aix demonstrate that atherosclerosis is a dynamic and (partially) reversible process.

Optimization of Chelation Process for Complex Microelement Iron Supplement Derived from Pig Blood by Response Surface Methodology

[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.

DFT Investigation of Chelation of Divalent Cations by Some 4-Benzylidenamino-4,5-Dihydro-lH-1,2,4- Triazol-5-One Derivatives

The complexation of BDHTD （4-benzylidenamino-4,5-dihydro-lH-l,2,4-triazol-5-one derivatives） by divalent doubly charged metal ions M2＋ （M = Mg, Ca, Fe and Cu） has been investigated using the density functional method B3LYP. Two distinct coordination modes （k2-O,O and k2-O,N） have been taken into account. Geometry optimizations have been performed in gas-phase and solution-phase： acetonitrile and DMF （N,N-dimethylformamide） with the basis set 6-31G（d,p）. The B3LYP method was also used to calculate the stability and free energies of the 24 complexes of BDHTD with metal ions M2＋ （M = Mg, Ca, Fe and Cu） respectively in gas-phase and solution-phase： acetonitrile and DMF. Results indicate that k2-O,N structures are most stable in gas-phase. The influence of substitution on the stability is sensitive in solution-phase. The interaction energies of complexation process in various media have been calculated at B3LYP/6-31G（d,p） and CCSD（T） level. The MIA （metal ion affinity） of BDHTD with M2＋ （M = Mg, Ca, Fe and Cu） in various media has been explored. The results show that the M1A highly varies with the coordination mode and substitution effect. From the calculated Gibb energies of complexation in various media, it is revealed that the complexation is possible in gas in acetonitrile. The ligand＇s affinity toward individual cation M2＋ （M = Mg, Ca, Fe and Cu） has been analysed. A significant reduce of BDEs observed confirms the decrease of the antioxidant activity by the metal chelation. The charge transfer induced by metal chelation is examined using the NBO analysis.

Ethylenediaminetetraacetic Acid Chelation for Band Keratopathy before Ab Interno Glaucoma Surgery

An 87-year-old woman with primary open-angle glaucoma presented to our hospital. Although the combined cataract and minimally invasive glaucoma surgeries (MIGS) were an appropriate surgical option, the presence of band keratopathy made it difficult to perform ab interno glaucoma surgery in her right eye (OD);therefore, the corneal opacity was removed using ethylenediaminetetraacetic acid (EDTA) chelation procedure. One month after chelation, microhook ab interno trabeculotomy and cataract surgery were performed successfully. Clear intraoperative visualization of the angle structures is critical for the success of these MIGS procedures. In glaucomatous eyes that require MIGS, EDTA chelation is a good neoadjuvant therapy for coexisting band keratopathy.

The Effect of EDTA Chelation Therapy in Symptomatic Coronary Heart Disease: An Observational Study

Ethylene Diamine Tetra Acetic Acid (EDTA) chelation therapy has been considered a definitive alternative therapy for by-pass surgery in atherosclerotic cardiovascular disease for more than four decades. It is a relatively inexpensive method believed to restore blood flow in atherosclerotic vessels. However, the benefits of chelation therapy yet remain controversial in the treatment of ischemic heart disease. We observed the effect of EDTA chelation therapy on exercise tolerance in 13 volunteering patients receiving conventional treatment for established symptomatic coronary heart disease. Each patient received 30 weekly infusions of EDTA followed by monthly 12 boosters according to the ACAM protocol (American College for Advancement in Medicine). This was in addition to the conventional therapies they received from their respective physician in hospital. Stress ECG, echocardiography and coronary angiogram findings were obtained at the beginning of treatment. The distance that a patient could walk on level ground at moderate speed and the number of steps he/she can climb up on a staircase until he/she begins to feel either chest pain or breathlessness were the two clinical parameters of exercise tolerance recorded to grade angina. Liver and renal functions were tested at 1st, 5th, 10th, 15th and 30th infusions. Of the 13 patients, 11 showed improvement in angina grading whilst 2 experienced no effect. One patient improved from angina grade IV to I, 6 from grade III to I, 1 from grade III to II and 3 from grade II to I. A statistically significant reduction in the mean score (p = 0.002) was noticed at 6th month of treatment when compared to that of the first month. A significant 1.7 fold increase (p = 0.009) in the mean SGPT level was observed at the 30th infusion when compared to the pre-treatment values. The SGOT level showed no significant change (p = 0.664). None of the patients showed clinical features of hepato-cellular damage. The mean serum creatinine level showed a trend for reduction (p = 0.083) with treatment. The recognized side effects of intravenous EDTA chelation therapy such as liver damage, renal damage, hypersensitivity, symptomatic hypocalcaemia, and thrombophlebitis were not encountered. Thus, EDTA chelation therapy as prescribed by the ACAM protocol seems safe and effective in improving exercise tolerance in ischemic heart disease when administered concurrently with conventional therapy.

Beliefs of Jordanian Children with Thalassemia toward Using Iron Chelation Therapy

Adherence to thalassemia treatment including chelation drugs is influenced by numerous factors. This study aims to explore beliefs about iron chelation therapy and adherence to this medication in Jordanian children with thalassemia major. In this descriptive cross-sectional study, seventy three patients were selected conveniently to complete the study instruments. Participants reported high adherence to their chelation therapy (88.1%). The majority (87.6%) expressed necessity for chelation therapy. However, 42.18% of the participants expressed their concerns about the therapy in which 57.9% of them showed concerns about dependency on medicine and 46.4% of them revealed concerns about the long-term effect of medicine. Overall, about 12.9% of the participants recorded correct and complete answers about thalassemia and its treatment. Knowledge about thalassemia and concerns about chelation were not significantly associated with adherence to the chelation therapy (r = 0.32, p = 0.19;r = 0.29, p = 0.25, respectively). However, there was a significant positive relationship between beliefs about the necessity of the therapy and adherence to it (r = 0.38, p = 0.03). In conclusion, Jordanian children showed proper adherence to their chelation therapy. Health care professionals should discuss patients’ concerns about chelation therapy which might increase patients’ adherence to their therapy.

Enhanced selectivity of hydrolytic precipitation of Zn from Zn-Ni sulfate solution via chelation of Ni

The selective precipitation of zinc from zinc-nickel sulfate solution with the Zn/Ni molar ratio of20:1was studied.Dropwise addition of0.5mol/L NaOH solution into the zinc-nickel sulfate solution containing0,0.01,0.02,0.03and0.04mol/L ethylene diamine tetraacetate(EDTA)as a chelating agent was done.The equilibrium analysis of precipitation pathway was performed using Visual MINTEQ program.The equilibrium analysis showed that the presence of small amounts of EDTA can prevent nickel precipitation in alkaline conditions without any negative effect on zinc precipitation.On this basis,more than90%of zinc could be precipitated as a product with about50%Zn and only0.11%Ni at pH=9.0merely as a result of the presence of0.03mol/L EDTA in the solution.The stirring time of120min after precipitation was found to be essential for more complete separation.The X-ray diffraction studies on the precipitate revealed that the precipitated phase was Zn4(OH)6SO4.4H2O.

Ciprofloxacin degradation in photo-Fenton and photo-catalytic processes: Degradation mechanisms and iron chelation

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.

Chelation of heavy metals by potassium butyl dithiophosphate

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.

2D-ultrathin MXene/DOXjade platform for iron chelation chemo-photothermal therapy

An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfortunately,current iron-based therapeutic strategies often lack effectiveness and can elicit off-target toxicities.We report here a dual-therapeutic prodrug,DOXjade,that allows for iron chelation chemo-photothermal cancer therapy.This prodrug takes advantage of the clinically approved iron chelator deferasirox(ExJade®)and the topoisomerase 2 inhibitor,doxorubicin(DOX).Loading DOXjade onto ultrathin 2D Ti_(3)C_(2) MXene nanosheets produces a construct,Ti_(3)C_(2)-PVP@DOXjade,that allows the iron chelation and chemotherapeutic functions of DOXjade to be photo-activated at the tumor sites,while potentiating a robust photothermal effect with photothermal conversion efficiencies of up to 40%.Antitumor mechanistic investigations reveal that upon activation,Ti_(3)C_(2)-PVP@DOXjade serves to promote apoptotic cell death and downregulate the iron depletion-induced iron transferrin receptor(TfR).A tumor pH-responsive iron chelation/photothermal/chemotherapy antitumor effect was achieved both in vitro and in vivo.The results of this study highlight what may constitute a promising iron chelation-based phototherapeutic approach to cancer therapy.