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Metal ions

Ali Serol Ertürk, Mustafa Ulvi Gürbüz, Metin Tülü, Abdürrezzak Emin Bozdoğan
Different generations (G3-G4) of amine-terminated Jeffamine® T-403 core poly(amidoamine) PAMAM dendrimers (JCPDs) were used as new macromolecular heavy metal chelating agent templates in polymer assisted ultrafiltration (PAUF) for the investigation of their removal ability for some of the divalent metal ions: Cu, Co, Ni, Cd, and Zn from aqueous solutions under competitive conditions. The effects of pH and generation size of JCPDs were also investigated. Extent of binding (EOB) data can be appropriately expressed by a tetradentate coordination for JCPDs at pH 9 where the maximum removal of metal ions was observed...
March 2018: Acta Chimica Slovenica
Agnieszka Drozd, Dominika Wojewska, Manuel David Peris-Díaz, Piotr Jakimowicz, Artur Krężel
Metallothioneins (MTs), small cysteine-rich proteins, present in four major isoforms, are key proteins involved in zinc and copper homeostasis in mammals. To date, only one X-ray crystal structure of a MT has been solved. It demonstrates seven bivalent metal ions bound in two structurally independent domains with M4S11 (α) and M3S9 (β) clusters. Recent discoveries indicate that Zn(ii) ions are bound with MT2 with the range from nano- to picomolar affinity, which determines its cellular zinc buffering properties that are demonstrated by the presence of partially Zn(ii)-depleted MT2 species...
March 21, 2018: Metallomics: Integrated Biometal Science
Martha M Gross, Arumugam Manthiram
Large scale energy storage for the electric grid will require low cost and high energy density solutions. We demonstrate in this letter a rechargeable zinc-aqueous polysulfide battery in which a metallic zinc anode is separated from a liquid aqueous polysulfide catholyte by an alkali-metal-ion solid-state electrolyte, wherein the alkali metal ion is Na+ or Li+. The solid-state electrolyte effectively separates the anode from the reactive polysulfide catholyte, preventing the crossover of the polysulfide species and maintaining good electrochemical performance with a reversible discharge capacity of 822 mA h g-1 with nearly 100% Coulombic efficiency...
March 21, 2018: ACS Applied Materials & Interfaces
Marija Nišavić, Goran V Janjić, Amela Hozić, Marijana Petković, Miloš K Milčić, Zoran Vujčić, Mario Cindrić
Binding of three ruthenium(ii) compounds of general formula mer-[Ru(L3)(N-N)X][Y] (where L3 = 4'-chloro-2,2':6',2''-terpyridine (Cl-tpy); N-N = 1,2-diaminoethane (en), 1,2-diaminocyclohexane (dach) or 2,2'-bipyridine (bipy); X = Cl; Y = Cl) to human serum albumin (HSA) has been investigated by nano-LC/nano-ESI MS and docking studies. A bottom-up proteomics approach has been applied for the structural characterization of metallated proteins and the data were analyzed in both the positive and negative ion mode...
March 21, 2018: Metallomics: Integrated Biometal Science
Ming Zheng, Fang-Yuan Chen, Jia-Nan Tian, Qing-Jiang Pan
To provide deep insight into cation-cation interactions (CCIs) involving hexavalent actinyl species that are major components in spent nuclear fuel and pose important implications for the effective removal of radiotoxic pollutants in the environment, a series of homo- and heterobimetallic actinide complexes supported by cyclopentadienyl (Cp) and polypyrrolic macrocycle (H4 L) ligands were systematically investigated using relativistic density functional theory. The metal sort in both parts of (THF)(H2 L)(OAnVI O) and (An')III Cp3 from U to Np to Pu, as well as the substituent bonding to Cp from electron-donating Me to H to electron-withdrawing Cl, SiH3 , and SiMe3 , was changed...
March 21, 2018: Inorganic Chemistry
Chunyang Wang, Qingyan Cheng, Yanji Wang
Several alkylammonium salts were used in the study of α-titanium phosphate (α-TiP) intercalation chemistry. The characterization results demonstrated that the expected intercalation by direct ion exchange could be successfully achieved without any addition of an extra amine substance. Our findings are different from the current opinion that by the ion-exchange method, without the assistance of bases, large cations are difficult to exchange into the narrow interlayer space of α-tetravalent metal phosphate directly because of the small interlayer distance...
March 21, 2018: Inorganic Chemistry
Zhiqiang Cheng, Shengzhe Zhao, Lihao Han
A novel method for synthesizing ZnO/γ-Al2O3 nanofibers by electrospinning and subsequent calcination is reported. The prepared nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The ZnO/γ-Al2O3 nanofibers exhibited excellent capacity for adsorbing organics with a negative zeta potential such as methyl orange (95.8%) and heavy metal ions such as Cr(vi) in aqueous solution...
March 21, 2018: Nanoscale
Shadpour Mallakpour, Elham Khadem
Chitosan nanocomposites containing 2, 5, 8 wt% of calcium carbonate-γ-aminopropyl triethoxy silane (CS/CC-ATS NCs) were prepared by ultrasonic irradiation. After characterizing of physicochemical properties of the obtained CS/CC-ATS NCs, their performance was evaluated for both the bone-like apatite mineralization and the removal of Cu(II). The field emission-scanning electron microscopy images from the in vitro bioactivity of the CS and the CS/CC-ATS NC 5 wt% displayed that the hydroxyapatite was produced on the samples surface...
March 17, 2018: International Journal of Biological Macromolecules
Priscila Aparecida Milani, João Luiz Consonni, Geórgia Labuto, Elma Neide Vasconcelos Martins Carrilho
Sugarcane bagasse and hydroponic lettuce roots were used as biosorbents for the removal of Cu(II), Fe(II), Mn(II), and Zn(II) from multielemental solutions and lake water, in batch processes. These biomasses were studied in natura (lettuce roots, NLR, and sugarcane bagasse, NSB) and chemically modified with HNO3 (lettuce roots, MLR, and sugarcane bagasse, MSB). The results showed higher adsorption efficiency for MSB and either NLR or MLR. The maximum adsorption capacities (qmax ) in multielemental solution for Cu(II), Fe(II), Mn(II), and Zn(II) were 35...
March 20, 2018: Environmental Science and Pollution Research International
Peitao Xiao, Fanxing Bu, Ranran Zhao, Mohamed F Aly Aboud, Imran Shakir, Yuxi Xu
Synthesis of ultrasmall metal-organic frameworks (MOFs) nanoparticles has been widely recognized as a promising route to greatly enhance their properties but remains a considerable challenge. Herein, we report one facile and effective spatial-confined thermal pulverization strategy to successfully transform bulk Co-MOFs particles into sub-5 nm nanocrystals encapsulated within N-doped carbon/graphene (NC/G) by using conducting polymer coated Co-MOFs/graphene oxide as precursors. This strategy involves a feasible mechanism: calcination of Co-MOFs at proper temperature in air induces the partial thermal collapse/distortion of the framework, while the uniform coating of conducting polymer can significantly improve the decomposition temperature and maintain the component stability of Co-MOFs, thus leading to the pulverization of bulk Co-MOFs particles into ultrasmall nanocrystals without oxidation...
March 20, 2018: ACS Nano
Vincent A Spata, Emily A Carter
Nanoparticles synthesized from plasmonic metals can absorb low-energy light, producing an oscillation/excitation of their valence electron density that can be utilized in chemical conversions. For example, heterogeneous photocatalysis can be achieved within heterometallic antenna-reactor complexes (HMARCs), by coupling a reactive center at which a chemical reaction occurs to a plasmonic nanoparticle that acts as a light-absorbing antenna. For example, HMARCs composed of aluminum antennae and palladium (Pd) reactive centers have been demonstrated recently to catalyze selective hydrogenation of acetylene to ethylene...
March 20, 2018: ACS Nano
Jacqueline M Zaengle-Barone, Abigail C Jackson, David M Besse, Bradford Becken, Mehreen Arshad, Patrick C Seed, Katherine J Franz
The unabated rise in bacterial resistance to conventional antibiotics, coupled with collateral damage to normal flora incurred by overuse of broad-spectrum antibiotics, necessitates the development of new antimicrobials targeted against pathogenic organisms. Here, we explore the antibacterial outcomes and mode of action of a prochelator that exploits the production of β-lactamase enzymes by drug-resistant bacteria to convert a non-toxic compound into a metal-binding antimicrobial agent directly within the microenvironment of pathogenic organisms...
March 20, 2018: ACS Infectious Diseases
Shan-Shan Li, Wen-Yi Zhou, Min Jiang, Zheng Guo, Jinhuai Liu, Lizhi Zhang, Xing-Jiu Huang
Developing a new ultra-sensitive interface to detect As(III) is highly desirable because of its seriously toxic and low concentration in drinking water. Recently, Fe3O4 nanoparticles of high adsorption toward As(III) become very promising to be such an interface, which is still limited by the poor understanding of their surface physicochemical properties. Herein, we report that dumbbell-like Au/Fe3O4 nanoparticles, when being modified the screen-printed carbon electrode, can serve as an efficient sensing interface for As(III) detection with an excellent sensitivity of 9...
March 20, 2018: Analytical Chemistry
Jeroen Sniekers, Pieter Geysens, Tom Vander Hoogerstraete, Luc Van Meervelt, Jan Fransaer, Koen Binnemans
Cobalt(ii)-containing ionic liquids were synthesized using N,N-dimethylformamide, N-methylpyrrolidone (NMP), dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMAc), pyridine-N-oxide (py-O), 1,10-phenanthroline (phen), ethylenediamine (en) and dimethylimidazolidinone (DMI) as ligands. The weakly coordinating bis(trifluoromethylsulfonyl)imide (Tf2N-) was used as a counter anion. Several compounds had a melting temperature below 100 °C, and the compound [Co(DMAc)6][Tf2N]2 was liquid at room temperature, with a viscosity of only 18 mPa s at 80 °C...
March 20, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Myeongsang Lee, Jae In Kim, Sungsoo Na, Kilho Eom
Amyloid β (Aβ) aggregates, which are a hallmark for neurodegenerative disease, are formed through a self-assembly process such as aggregation of Aβ peptide chains. This aggregation process depends on the solvent conditions under which the proteins are aggregated. Nevertheless, the underlying mechanism of the ionic effect on the formation and stability of amyloid aggregates has not been fully understood. Here, we report how metal ions play a role in the formation and stability of Aβ aggregates at different length scales, i...
March 20, 2018: Physical Chemistry Chemical Physics: PCCP
Jin Zheng, Xiao-Qian Gu, Tai-Jie Zhang, Hui-Hui Liu, Qiao-Jing Ou, Chang-Lian Peng
Seagrasses play an important role in coastal marine ecosystems, but they have been increasingly threatened by human activities. In recent years, seagrass communities have rapidly degenerated in the coastal marine ecosystems of China. To identify the reasons for the decline in seagrasses, the phytotoxic effects of trace metals (Cu, Cd and Zn) on the seagrass Thalassia hemprichii were investigated, and the environmental contents of the metals were analyzed where the seagrass grows. The results showed that leaf necrosis in T...
March 19, 2018: Ecotoxicology
Md Saddam Hossain, Takahiro Tanaka, Kazuyoshi Takagi, Junji Hayashi, Mamoru Wakayama
In the present study, we purified α-amino acid ester hydrolase (AEH) from cell-free extracts of the Stenotrophomonas maltophilia strain HS1. The approximately 70-kDa AEH from S. maltophilia HS1 (SmAEH) was homogeneous in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analyses, and was present as a tetramer in gel-filtration experiments. The activity of the SmAEH enzyme was then determined by monitoring the synthesis of the antihypertensive agent dipeptide isoleucyl-tryptophan (Ile-Trp) from isoleucyl methyl ester (Ile-OMe) and tryptophan (Trp)...
March 2018: 3 Biotech
Weixiang Liu, Yukun Qin, Song Liu, Ronge Xing, Huahua Yu, Xiaolin Chen, Kecheng Li, Pengcheng Li
Based on a condensation reaction, a chitosan-derivative-bearing amino pyridine group was prepared and subsequently followed by coordination with cupric ions, zinc ions and nickel ions to synthesize chitosan metal complexes. The calculations using the density functional theory (DFT) show that the copper ions and nickel ions underwent dsp2 hybridization, the zinc ions underwent sp3 hybridization, and they all formed a coordination bond with the carbon atom in the p-π conjugate group. The antifungal properties of O-CSPX-M against Phytophthora capsici (P...
March 19, 2018: Scientific Reports
Gee Yeong Kim, Alessandro Senocrate, Tae-Youl Yang, Giuliano Gregori, Michael Grätzel, Joachim Maier
In the same way as electron transport is crucial for information technology, ion transport is a key phenomenon in the context of energy research. To be able to tune ion conduction by light would open up opportunities for a wide realm of new applications, but it has been challenging to provide clear evidence for such an effect. Here we show through various techniques, such as transference-number measurements, permeation studies, stoichiometric variations, Hall effect experiments and the use of blocking electrodes, that light excitation enhances by several orders of magnitude the ionic conductivity of methylammonium lead iodide, the archetypal metal halide photovoltaic material...
March 19, 2018: Nature Materials
Zengyin Zhu, Mancheng Zhang, Wei Wang, Qing Zhou, Fuqiang Liu
A series of magnetic multi-amine resins (MMARs, named E1D9-E9D1) was proposed for the removal of tetracycline (TC) and Cu(II) in sole and binary solutions. Results showed that the N content of the resins increased sharply from 1.7% to 15.49%, and the BET surface areas decreased from 1433.4 m2 /g to 8.9 m2 /g with methyl acrylate ratio increasing from E1D9 to E9D1. Their adsorption capacities for TC and Cu(II) could reach 0.243 and 0.453 mmol/g, respectively. The adsorption isotherms of TC onto MMARs transformed from heterogeneous adsorption to monolayer-type adsorption with DVB monomer ratio in resin matrix decrease, suggesting the dominant physical adsorption between TC and benzene rings...
March 19, 2018: Scientific Reports
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