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
Magnetic resonance imaging(MRI)is a non-invasive medical imaging technique that has been widely applied in the clinical diagnosis of diseases across various fields.Currently,there is a dearth of high-performance dual-...Magnetic resonance imaging(MRI)is a non-invasive medical imaging technique that has been widely applied in the clinical diagnosis of diseases across various fields.Currently,there is a dearth of high-performance dual-mode contrast agents that provide precise diagnostic information for complex diseases.In this study,iron oxide-gadolinium nanoparticles(IO-Gd NPs)bridged by hydrophilic ligand ethylenedi-amine tetramethylenephosphonic acid(EDTMP)are designed inspired by Solomon-Bloembergen-Morgan(SBM)theory,where T_(1)and T_(2)relaxivity increase with a reduction in Gd content.In particular,the NPs with minimum Gd content exhibit excellent dual-mode contrast performance(r_(1)=94.42 mM^(−1)s^(−1),r_(2)=343.62 mM^(−1)s^(−1)).The underlying mechanism is that the bridged EDTMP coordinate limits Gd tum-bling and forces Gd^(3+)to expose itself to the surface of the NPs.This provides more opportunities for water molecules to coordinate with Gd^(3+)and significantly enhances proton relaxivity.Moreover,the hy-drophilicity of the ligand enhances the water dispersion stability of the NPs and increases the exchange rate of water protons near the NPs,further enhancing the dual-mode contrast effect.Finally,the biocom-patibility and in vitro/vivo imaging performances of the IO@EDTMP-Gd NPs are systematically evaluated,and the results demonstrate their potential as dual-mode contrast agents.This study provides a new strategy for developing dual-mode MRI contrast agents that can further improve the accuracy of MRI in the diagnosis of complex diseases.展开更多
Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carb...Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carbon-carbon or carbon-heteroatom bonds.Chelating group directed metal-catalyzed remote functionalization of readily available alkenes has emerged as an appealing strategy for rapidly accessing various value-added aliphatic molecules.With the aid of directing groups,variousα-,β-andγ-functionalized alkanes could be synthesized smoothly with excellent regioselectivity.The preferred formation of a stable five-or six-membered metallacycle intermediate terminates the chain-walking at a specific methylene site,which serves as the driving force for excellent site-selective migratory functionalization.This review herein is aimed at summarizing the recent progress on the metal-catalyzed regiodivergent functionalization of unactivated alkenes by merging alkene isomerization and cross-coupling with the assistance of directing auxiliary.Last but not least,the current situations and future directions in this field are highlighted and discussed.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
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
[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
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
A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of...A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(Ⅱ) and Ni(Ⅱ) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(Ⅱ) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed thatthe Si-AMPY-1 resin can efficiently separate Cu(Ⅱ) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(Ⅱ) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(Ⅱ) from the nickel electrolyte.展开更多
A new chelating resin （CPS-DMA-SABA） was synthesized with the chloromethylated crossqinked polystyrene porous beads （CPS） as raw materials, which were bonded with salicylidene-o-aminobenzoic acid （SABA） on the s...A new chelating resin （CPS-DMA-SABA） was synthesized with the chloromethylated crossqinked polystyrene porous beads （CPS） as raw materials, which were bonded with salicylidene-o-aminobenzoic acid （SABA） on the surface via a quaternary ammonium unit as a linker. The results showed that CPS-DMA-SABA would easily change into a zwitterionic chelating resin （CPS-DMA-SABZ） when washed with distilled water. CPS-DMA-SABA was characterized by elemental analysis, infrared spectra and thermo-gravimetric analysis. The ion sorption capacities of CPS-DMA-SABA were found to be 1916 μg/g for Zn2＋ withpH at 4.5, 1620μg/g for Cu2＋ with pH at 6.2, 1291 μg/g for Ni2＋ withpH at 6.6 and 780 μg/g for Cr3＋ withpH at 5.5, respectively. The experiments showed CPS-DMA-SABA also changed its color when meeting with the metal ion in the aqueous solution. As a consequence, CPS-DMA-SABA can not only be used as a solid phase extractant but also an indicator for confirming the heavy metal ion in solutions.展开更多
In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence o...In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).展开更多
The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson’s disease during the long-term chelating therapy using magnetic resonance imaging and a possible signiifcance of the time ...The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson’s disease during the long-term chelating therapy using magnetic resonance imaging and a possible signiifcance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson’s disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into： group A, where chelating therapy was initiated 〈 24 months from the ifrst symp-toms and group B, where the therapy started≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a signiifcant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions （P= 0.005 andP=0.024, respectively）. If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be ex-pected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.展开更多
A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective...A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and triphenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy （IR） and X-ray photoelectron spectroscopy （XPS） of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorption of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb （ Ⅱ ） of cerussite to form chelate.展开更多
This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height ...This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height (7.0–14.0 cm),feed flow rate (4.5–9.0 mL/min),initial copper (Ⅱ) concentration of the feed (250–1000 mg/L),feed temperature (25–40 ℃) and the value of pH (2.0–4.0) on the adsorption process of the PS-AMP resin were investigated.The experimental data showed that the PS-AMP resin can deeply eliminate copper (Ⅱ) from the simulated cobalt electrolyte.The bed height,feed flow rate,initial copper (Ⅱ) concentration of the feed,feed temperature and feed pH value which corresponded to the highest removal of copper (Ⅱ) were 7.0 cm with 35 mm of the column diameter,4.5 mL/min,40℃,1000 mg/L and 4.0,respectively.The breakthrough capacity,the saturated capacity of the column and the mass ratio of Cu/Co (g/g) in the saturated resin were correspondingly 16.51 mg/g dry resin,61.72 mg/g dry resin and 37.67 under the optimal experimental conditions.The copper (Ⅱ) breakthrough curves were fitted by the empirical models of Thomas,Yoon-Nelson and Adam-Bohart,respectively.The Thomas model was found to be the most suitable one for predicting how the concentration of copper (Ⅱ) in the effluent changes with the adsorption time.展开更多
AIM To investigate the copper-chelating therapeutic effect in Wilson disease (WD) with different clinical phenotypes and polymorphisms of ATP7B gene.METHODS One hundred and twenty-two WD patients with different clinic...AIM To investigate the copper-chelating therapeutic effect in Wilson disease (WD) with different clinical phenotypes and polymorphisms of ATP7B gene.METHODS One hundred and twenty-two WD patients with different clinical phenotypes were given DMPS intravenously and Gandou copper-chelating tablet orally for one month. The therapeutic effect was judged by modified Goldstein mothod. Exon 18 of ATP7B gene extracted from the DNA of patients and 20 healthy volunteers was amplified with PCR mutation and polymorphism were screened with SSCP technique.RESULTS Four kinds of abnormal migration bands in PCR-SSCP were observed in 37 WD patients, mutation frequencies of three different disease phenotypes, and curative effect between mutation group and non-mutation group showed no statistically significant difference (P＞0.05), but the total effectiveness rates in patients with Wilson type or pseudosclerosis type were significantly higher than those of patients with hepatic type (X2=6.17, P＜0.05).CONCLUSION Most WD patients are compound heterozygotes, the patients with different clinical phenotypes have different response to copper-chelating therapy. Specific mutation, at least in part, plays a role in influencing the disease phenotypes and therapeutic effect.展开更多
In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric aci...In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric acid, oxalic acid and ethylenediamine tetraaceatate(EDTA) to maintain available Fe2+. The results indicate that the concentration of chelating agent and ferrous ion didn't follow a linear relationship with the degradation rate of aniline. A 1/1 ratio of chelating agent/Fe2+ results in a higher degradation rate compared to the results by other ratios. The oxidation enhancement factor using oxalic acid was found to be relatively low. In contrast, citric acid is more suitable chelating agent in the ferrous iron activated persulfate system and aniline exhibits a highest degradation with a persulfate/Fe2+/citric acid/aniline molar ratio of 50/25/25/1 compared to other molar ratios.展开更多
Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidizati...Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidization reaction of maleic anhydride by hydrogen peroxide, with phenol-formaldehyde resin containing polyamine (FQ resins series). The effects of such factors as reaction time, reaction temperature and pH value on the loading capacity of TTA in resins were investigated. The results showed that the optimum reaction conditions are as follows: time 9-12 h; temperature 90-105'C; pH value 6-10. The loading capacities of TTA can reach 0.15, 0.14, and 0.11 mmol/g-1 when the functional group of FQ resin was - OCH2CH2NHC2H4NH2, - O(CH2CH2NH)2C2H4NH2 and - O(CH2CH2NH)3C2H4NH2), respectively. The structures of resins were characterized by FTIR spectra. The primary study on the adsorption properties of the resins for metal ions showed that there are two kinds of adsorption mechanisms i.e. ion exchange and chelate in the adsorption process. TTA-FQ resins have much higher adsorption selectivity for Pb2+and Zn2+ than for Cu2+ and Ni2+. These resins can probably be used for separating Pb2+ or Zn2+ in the mixture of metal ions or for treating wastewater containing heavy metal ions.展开更多
A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating r...A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating resin for Pb2+ were studied by batch adsorption, and the adsorption process was analyzed from thermodynamics and kinetics aspects. The adsorption mechanism of Pb2+ on the modified D401 chelating resin was discussed by FT-IR spectrometry. Experimental results show that in the Pb2+ concentration range of 200-400 mg/L, the adsorption capacities of the modified D401 chelating resin for Pb2+ increase by 77%-129%, and Langmuir isothermal adsorption model is more suitable for the equilibrium adsorption data. Adsorption is an endothermic process that runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best pH value under adsorption condition is 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the adsorption capacity remains stable after five consecutive adsorption-desorption cycles. The maximal static saturated adsorption capacity of the resin is 206 mg/g at 333 K in the Pb2+ concentration range of 200-400 mg/L. The modified D401 chelating resin is an efficient adsorbent for the removal of Pb2+ from its single-metal ion solution.展开更多
A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of poly...A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol containing sulfur. These chelating resins were found to show high adsorption capacities for Ag^＋, Hg^2＋, Au^3＋ and Pd^2＋, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.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supported by the National Key R&D Program of China(Nos.2020YFA0710800,2022YFE0124500)the National Natural Science Foundation of China(Nos.32271467,32071364)+1 种基金the Outstanding Postdoctoral Program of Jiangsu Province(No.2022ZB367)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Magnetic resonance imaging(MRI)is a non-invasive medical imaging technique that has been widely applied in the clinical diagnosis of diseases across various fields.Currently,there is a dearth of high-performance dual-mode contrast agents that provide precise diagnostic information for complex diseases.In this study,iron oxide-gadolinium nanoparticles(IO-Gd NPs)bridged by hydrophilic ligand ethylenedi-amine tetramethylenephosphonic acid(EDTMP)are designed inspired by Solomon-Bloembergen-Morgan(SBM)theory,where T_(1)and T_(2)relaxivity increase with a reduction in Gd content.In particular,the NPs with minimum Gd content exhibit excellent dual-mode contrast performance(r_(1)=94.42 mM^(−1)s^(−1),r_(2)=343.62 mM^(−1)s^(−1)).The underlying mechanism is that the bridged EDTMP coordinate limits Gd tum-bling and forces Gd^(3+)to expose itself to the surface of the NPs.This provides more opportunities for water molecules to coordinate with Gd^(3+)and significantly enhances proton relaxivity.Moreover,the hy-drophilicity of the ligand enhances the water dispersion stability of the NPs and increases the exchange rate of water protons near the NPs,further enhancing the dual-mode contrast effect.Finally,the biocom-patibility and in vitro/vivo imaging performances of the IO@EDTMP-Gd NPs are systematically evaluated,and the results demonstrate their potential as dual-mode contrast agents.This study provides a new strategy for developing dual-mode MRI contrast agents that can further improve the accuracy of MRI in the diagnosis of complex diseases.
基金the National Natural Science Foundation of China(No.22001116)the Basic and Applied Basic Research Foundation of Guangdong Province(No.2020A1515110816)funds provided by Changzhou University(No.ZMF23020217)。
文摘Aliphatic C(sp^(3))-H moieties are ubiquitous in numerous organic compounds.Direct functionalization of inert C(sp^(3))-H bonds is a powerful and straightforward approach for the efficient construction of diverse carbon-carbon or carbon-heteroatom bonds.Chelating group directed metal-catalyzed remote functionalization of readily available alkenes has emerged as an appealing strategy for rapidly accessing various value-added aliphatic molecules.With the aid of directing groups,variousα-,β-andγ-functionalized alkanes could be synthesized smoothly with excellent regioselectivity.The preferred formation of a stable five-or six-membered metallacycle intermediate terminates the chain-walking at a specific methylene site,which serves as the driving force for excellent site-selective migratory functionalization.This review herein is aimed at summarizing the recent progress on the metal-catalyzed regiodivergent functionalization of unactivated alkenes by merging alkene isomerization and cross-coupling with the assistance of directing auxiliary.Last but not least,the current situations and future directions in this field are highlighted and discussed.
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.
基金Project (2014CB643401) supported by the National Basic Research Program of ChinaProjects (51134007,51474256) supported by the National Natural Science Foundation of ChinaProject (2016TP1007) supported by the Hunan Provincial Science and Technology Plan Project in China
文摘A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(Ⅱ) and Ni(Ⅱ) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(Ⅱ) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed thatthe Si-AMPY-1 resin can efficiently separate Cu(Ⅱ) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(Ⅱ) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(Ⅱ) from the nickel electrolyte.
基金supported by the National Natural Science Foundation of China(No.50873042)the Natural Science Foundation for Colleges and Universities of Jiangsu Province(No.11KJA430008)
文摘A new chelating resin （CPS-DMA-SABA） was synthesized with the chloromethylated crossqinked polystyrene porous beads （CPS） as raw materials, which were bonded with salicylidene-o-aminobenzoic acid （SABA） on the surface via a quaternary ammonium unit as a linker. The results showed that CPS-DMA-SABA would easily change into a zwitterionic chelating resin （CPS-DMA-SABZ） when washed with distilled water. CPS-DMA-SABA was characterized by elemental analysis, infrared spectra and thermo-gravimetric analysis. The ion sorption capacities of CPS-DMA-SABA were found to be 1916 μg/g for Zn2＋ withpH at 4.5, 1620μg/g for Cu2＋ with pH at 6.2, 1291 μg/g for Ni2＋ withpH at 6.6 and 780 μg/g for Cr3＋ withpH at 5.5, respectively. The experiments showed CPS-DMA-SABA also changed its color when meeting with the metal ion in the aqueous solution. As a consequence, CPS-DMA-SABA can not only be used as a solid phase extractant but also an indicator for confirming the heavy metal ion in solutions.
基金financially supported by the National Natural Science Foundation of China(No.21878330,21676298)the National Key R&D Program of China(2019YFC1907602)the CNPC Key Research Project(2016E-0707)。
文摘In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).
基金supported by a grant from the Ministry of Science and Technological Development of Serbia,Scientific Project Number 175090
文摘The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson’s disease during the long-term chelating therapy using magnetic resonance imaging and a possible signiifcance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson’s disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into： group A, where chelating therapy was initiated 〈 24 months from the ifrst symp-toms and group B, where the therapy started≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a signiifcant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions （P= 0.005 andP=0.024, respectively）. If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be ex-pected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.
文摘A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and triphenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy （IR） and X-ray photoelectron spectroscopy （XPS） of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorption of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb （ Ⅱ ） of cerussite to form chelate.
基金Project(2014CB643401)supported by the National Basic Research Program of ChinaProjects(51134007,51474256)supported by the National Natural Science Foundation of ChinaProject(2017TP1001)supported by the Hunan Provincial Science and Technology Plan Project,China
文摘This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height (7.0–14.0 cm),feed flow rate (4.5–9.0 mL/min),initial copper (Ⅱ) concentration of the feed (250–1000 mg/L),feed temperature (25–40 ℃) and the value of pH (2.0–4.0) on the adsorption process of the PS-AMP resin were investigated.The experimental data showed that the PS-AMP resin can deeply eliminate copper (Ⅱ) from the simulated cobalt electrolyte.The bed height,feed flow rate,initial copper (Ⅱ) concentration of the feed,feed temperature and feed pH value which corresponded to the highest removal of copper (Ⅱ) were 7.0 cm with 35 mm of the column diameter,4.5 mL/min,40℃,1000 mg/L and 4.0,respectively.The breakthrough capacity,the saturated capacity of the column and the mass ratio of Cu/Co (g/g) in the saturated resin were correspondingly 16.51 mg/g dry resin,61.72 mg/g dry resin and 37.67 under the optimal experimental conditions.The copper (Ⅱ) breakthrough curves were fitted by the empirical models of Thomas,Yoon-Nelson and Adam-Bohart,respectively.The Thomas model was found to be the most suitable one for predicting how the concentration of copper (Ⅱ) in the effluent changes with the adsorption time.
文摘AIM To investigate the copper-chelating therapeutic effect in Wilson disease (WD) with different clinical phenotypes and polymorphisms of ATP7B gene.METHODS One hundred and twenty-two WD patients with different clinical phenotypes were given DMPS intravenously and Gandou copper-chelating tablet orally for one month. The therapeutic effect was judged by modified Goldstein mothod. Exon 18 of ATP7B gene extracted from the DNA of patients and 20 healthy volunteers was amplified with PCR mutation and polymorphism were screened with SSCP technique.RESULTS Four kinds of abnormal migration bands in PCR-SSCP were observed in 37 WD patients, mutation frequencies of three different disease phenotypes, and curative effect between mutation group and non-mutation group showed no statistically significant difference (P＞0.05), but the total effectiveness rates in patients with Wilson type or pseudosclerosis type were significantly higher than those of patients with hepatic type (X2=6.17, P＜0.05).CONCLUSION Most WD patients are compound heterozygotes, the patients with different clinical phenotypes have different response to copper-chelating therapy. Specific mutation, at least in part, plays a role in influencing the disease phenotypes and therapeutic effect.
基金Project(2010B050200007)supported by the Foundation of Science and Technology Planning Project of Guangdong Province,ChinaProject(2011ZM0054)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(2011K0013)supported by the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,ChinaProject(2012)supported by the Research Funds of Guangdong Provincial Key Laboratory of Atmospheric environment and Pollution Control,China
文摘In the interest of accelerating aniline degradation, Fe2+ and chelated Fe2+ activated persulfate oxidations were investigated in neutral pH condition. Three kinds of chelating agents were selected including citric acid, oxalic acid and ethylenediamine tetraaceatate(EDTA) to maintain available Fe2+. The results indicate that the concentration of chelating agent and ferrous ion didn't follow a linear relationship with the degradation rate of aniline. A 1/1 ratio of chelating agent/Fe2+ results in a higher degradation rate compared to the results by other ratios. The oxidation enhancement factor using oxalic acid was found to be relatively low. In contrast, citric acid is more suitable chelating agent in the ferrous iron activated persulfate system and aniline exhibits a highest degradation with a persulfate/Fe2+/citric acid/aniline molar ratio of 50/25/25/1 compared to other molar ratios.
基金This work was supported by the Postdoctoral Science Foundation of China (No. 2003034330), the Science Foundation forElite of Middle Age and Youth of Shandong Province, the Natural Science Foundation of Shandong Province (No. Q99B15)and the National Natural Science Foundation of China (No. 29906008).
文摘Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidization reaction of maleic anhydride by hydrogen peroxide, with phenol-formaldehyde resin containing polyamine (FQ resins series). The effects of such factors as reaction time, reaction temperature and pH value on the loading capacity of TTA in resins were investigated. The results showed that the optimum reaction conditions are as follows: time 9-12 h; temperature 90-105'C; pH value 6-10. The loading capacities of TTA can reach 0.15, 0.14, and 0.11 mmol/g-1 when the functional group of FQ resin was - OCH2CH2NHC2H4NH2, - O(CH2CH2NH)2C2H4NH2 and - O(CH2CH2NH)3C2H4NH2), respectively. The structures of resins were characterized by FTIR spectra. The primary study on the adsorption properties of the resins for metal ions showed that there are two kinds of adsorption mechanisms i.e. ion exchange and chelate in the adsorption process. TTA-FQ resins have much higher adsorption selectivity for Pb2+and Zn2+ than for Cu2+ and Ni2+. These resins can probably be used for separating Pb2+ or Zn2+ in the mixture of metal ions or for treating wastewater containing heavy metal ions.
基金Project(708049) supported by the Important Item Cultivation Foundation of Scientific Innovation Project of Colleges and Universities of China
文摘A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating resin for Pb2+ were studied by batch adsorption, and the adsorption process was analyzed from thermodynamics and kinetics aspects. The adsorption mechanism of Pb2+ on the modified D401 chelating resin was discussed by FT-IR spectrometry. Experimental results show that in the Pb2+ concentration range of 200-400 mg/L, the adsorption capacities of the modified D401 chelating resin for Pb2+ increase by 77%-129%, and Langmuir isothermal adsorption model is more suitable for the equilibrium adsorption data. Adsorption is an endothermic process that runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best pH value under adsorption condition is 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the adsorption capacity remains stable after five consecutive adsorption-desorption cycles. The maximal static saturated adsorption capacity of the resin is 206 mg/g at 333 K in the Pb2+ concentration range of 200-400 mg/L. The modified D401 chelating resin is an efficient adsorbent for the removal of Pb2+ from its single-metal ion solution.
基金The authors are grateful to the financial support by the Postdoctoral Science Foundation of China(No.2003034330)the Science Foundation for mid-youth elite of Shangdong Province+1 种基金the Natural Science Foundation of Shangdong Province(No.Q99B15)the National Natural Science Foundation of China(No.2906008)
文摘A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol containing sulfur. These chelating resins were found to show high adsorption capacities for Ag^＋, Hg^2＋, Au^3＋ and Pd^2＋, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.
