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Metal ions

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https://www.readbyqxmd.com/read/28431314/effect-of-metals-on-microcystin-abundance-and-environmental-fate
#1
Guofei Dai, Ningyan Peng, Jiayou Zhong, Ping Yang, Binchun Zou, Hui Chen, Qian Lou, Yuanyuan Fang, Wei Zhang
Metals can react with microcystin (MC), which is released from cyanobacterial blooms through various mechanisms; these reactions may mitigate the environmental and health risks of MCs but may also cause harm to aquatic ecosystems and humans. Several studies were conducted, including laboratory tests, ecological simulations, and a field investigation of Poyang Lake. The laboratory studies showed that Fe(3+), Cu(2+), and Pb(2+) stimulated MC photodegradation under high light intensity at the water-sediment interface, which reduced the MC accumulation in the sediment...
April 18, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28430407/three-dimensional-arylene-diimide-frameworks-for-highly-stable-lithium-ion-batteries
#2
Tyler B Schon, Andrew J Tilley, Emily L Kynaston, Dwight S Seferos
Lithium-ion batteries are the best commercial technology to satisfy the energy storage needs of current and emerging applications. However, the use of transition metal-based cathodes precludes them from being low cost, sustainable, and environmentally benign, even with recycling programs in place. In this study, we report a highly stable organic material that can be used in place of the transition metal cathodes. By creating a three-dimensional framework based on triptycene and perylene diimide (PDI), a cathode can be constructed that mitigates stability issues that organic electrodes typically suffer from...
April 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28430238/microsensors-based-on-a-whispering-gallery-mode-in-algan-microdisks-undercut-by-hydrogen-environment-thermal-etching
#3
Tetsuya Kouno, Masaru Sakai, Hoshi Takeshima, Sho Suzuki, Akihiko Kikuchi, Katsumi Kishino, Kazuhiko Hara
AlGaN microdisks were fabricated via a top-down process using electron-beam lithography, inductively coupled plasma reactive-ion etching, and hydrogen-environment thermal etching from commercial epitaxial wafers with a 100-300 nm thick AlGaN layer grown on a c-plane GaN layer by metal-organic chemical vapor deposition. The hydrogen-environment thermal etching performed well in undercutting the AlGaN microdisks owing to the selective etching for the GaN layer. The AlGaN microdisks acted as the whispering gallery mode (WGM) optical microresonators, exhibiting sharp resonant peaks in room temperature photoluminescence spectra...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430191/activating-lattice-oxygen-redox-reactions-in-metal-oxides-to-catalyse-oxygen-evolution
#4
Alexis Grimaud, Oscar Diaz-Morales, Binghong Han, Wesley T Hong, Yueh-Lin Lee, Livia Giordano, Kelsey A Stoerzinger, Marc T M Koper, Yang Shao-Horn
Understanding how materials that catalyse the oxygen evolution reaction (OER) function is essential for the development of efficient energy-storage technologies. The traditional understanding of the OER mechanism on metal oxides involves four concerted proton-electron transfer steps on metal-ion centres at their surface and product oxygen molecules derived from water. Here, using in situ (18)O isotope labelling mass spectrometry, we provide direct experimental evidence that the O2 generated during the OER on some highly active oxides can come from lattice oxygen...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28430017/two-nramp6-isoforms-function-as-iron-and-manganese-transporters-and-contribute-to-disease-resistance-in-rice
#5
Cristina Peris-Peris, Albert Serra-Cardona, Ferrán Sánchez-Sanuy, Sonia Campo, Joaquin Ariño, Blanca San Segundo
Metal ions are essential elements for all living organisms. However, metals can be toxic when present in excess. In plants, metal homeostasis is partly achieved through the function of metal transporters, including the diverse natural resistance-associated macrophage proteins (NRAMP). Among them, the OsNramp6 gene encodes a previously uncharacterized member of the rice NRAMP family that undergoes alternative splicing to produce different NRAMP6 proteins. In this work, we determined the metal transport activity and biological role of the full-length and the shortest NRAMP6 proteins (l-NRAMP6 and s-NRAMP6, respectively)...
April 21, 2017: Molecular Plant-microbe Interactions: MPMI
https://www.readbyqxmd.com/read/28429586/bubble-mediated-ultrasensitive-multiplex-detection-of-metal-ions-in-three-dimensional-dna-nanostructure-encoded-microchannels
#6
Xiangmeng Qu, Fan Yang, Hong Chen, Jiang Li, Hongbo Zhang, Guo-Jun Zhang, Li Li, Lihua Wang, Shiping Song, Yang Tian, Hao Pei
The development of rapid and sensitive point-of-test devices for the on-site monitoring of heavy-metal contamination has great scientific and technological importance. However, developing fast, inexpensive, and sensitive microarray sensors to achieve such goal remains challenging. In this work, we present a DNA nanostructured microarray (DNM) with tubular three-dimensional (3D) sensing surface and ordered nanotopography. This microarray enables enhanced molecular interaction toward the rapid and sensitive multiplex detection of heavy-metal ions...
April 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28429580/metal-ion-coupled-consecutive-photoinduced-electron-transfer-generates-strong-reduction-potentials-from-visible-light
#7
Andreas Meyer, Tomas Slanina, Alexander Heckel, Burkhard König
Metal ions can have beneficial effects on photoinduced electron transfer. Merging such metal-ion coupled electron transfer (MCET) with consecutive photoinduced electron transfer (conPET) enables the one-electron reduction of chlorobenzene with blue light in the presence of diisopropylethylamine as electron donor. The presence of the metal ions extends the substrate scope of the photoredox catalysis to extreme reduction potentials (beyond -3 V vs SCE).
April 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28429174/a-unique-sensitive-and-highly-selective-fluorescent-naphthodiaza-crown-macrocyclic-ligand-chemosensor-for-hg-2-in-water
#8
Bahram Ghanbari, Morteza Zarepour-Jevinani
The noticeable enhancement in fluorescence emission of O2N2-donor naphthodiaza-crown macrocyclic ligand (L) in the presence of Hg(2+) was observed in which the fluorescence quantum yield of free ligand L as well as L/Hg(2+) complex were found to be as 0.29 and 0.49, respectively. The observed ultra-low limit of detection (LOD) for Hg(2+) by L was determined as low as 1.0 × 10(-11) M in water. A 1:1 stoichiometry was also established for L/Hg(2+) together with a binding constant K BH = 66,543 by employing fluorescence spectrophotometry...
April 20, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28429014/formation-of-mono-and-binuclear-neodymium-iii-gluconate-complexes-in-aqueous-solutions-in-the-ph-range-of-2-8
#9
Bence Kutus, Norbert Varga, Gábor Peintler, Alexandru Lupan, Amr A A Attia, István Pálinkó, Pál Sipos
The complex formation between Nd(iii) and d-gluconate (Gluc(-)) is of relevance in modelling the chemical equilibria of radioactive waste repositories. In the present work, the formation of NdpGlucqH-r complexes at 25 °C and pH = 2-8 was studied via spectrophotometry, potentiometry, freezing point depression, conductometry and NMR spectroscopy. In addition to the four mononuclear complexes (pq-r = 110, 120, 130 and 11-2), the formation of two binuclear, so far unknown complexes (pq-r = 23-2 and 24-2) was revealed...
April 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28428986/ruthenium-cobalt-dinuclear-complexes-as-photocatalysts-for-co2-reduction
#10
X Wang, V Goudy, G Genesio, J Maynadié, D Meyer, M Fontecave
A series of Ru-Co dinuclear complexes have been synthesized and assayed as photocatalysts for the reduction of CO2 to CO in organic solvents. The Ru-Co complexes, with tris-diimine coordination at the Co ion, are the best supramolecular photocatalysts for CO2 reduction with a non-noble metal catalytic center reported so far.
April 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28428797/silicon-regulates-antioxidant-activities-of-crop-plants-under-abiotic-induced-oxidative-stress-a-review
#11
REVIEW
Yoon-Ha Kim, Abdul L Khan, Muhammad Waqas, In-Jung Lee
Silicon (Si) is the second most abundant element in soil, where its availability to plants can exhilarate to 10% of total dry weight of the plant. Si accumulation/transport occurs in the upward direction, and has been identified in several crop plants. Si application has been known to ameliorate plant growth and development during normal and stressful conditions over past two-decades. During abiotic (salinity, drought, thermal, and heavy metal etc) stress, one of the immediate responses by plant is the generation of reactive oxygen species (ROS), such as singlet oxygen ((1)O2), superoxide ([Formula: see text]), hydrogen peroxide (H2O2), and hydroxyl radicals (OH), which cause severe damage to the cell structure, organelles, and functions...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28428536/real-time-observation-of-interfacial-ions-during-electrocrystallization
#12
Masashi Nakamura, Takahiro Banzai, Yuto Maehata, Osamu Endo, Hiroo Tajiri, Osami Sakata, Nagahiro Hoshi
Understanding the electrocrystallization mechanisms of metal cations is of importance for many industrial and scientific fields. We have determined the transitional structures during underpotential deposition (upd) of various metal cations on Au(111) electrode using time-resolved surface X-ray diffraction and step-scan IR spectroscopy. At the initial stage of upd, a characteristic intensity transient appears in the time-resolved crystal truncation rod depending on metal cations. Metal cations with relatively high coordination energies of hydration water are deposited in two steps: first, the hydrated metal cations approached the surface and are metastably located at the outer Helmholtz plane, then they are deposited via the destruction of the hydration shell...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28428129/three-phase-partitioning-a-scalable-method-for-the-purification-and-recovery-of-cucumisin-a-milk-clotting-enzyme-from-the-juice-of-cucumis-melo-var-reticulatus
#13
Mohammed Gagaoua, Ferhat Ziane, Sabrina Nait Rabah, Nawel Boucherba, Amel Ait Kaki El-Hadef El-Okki, Amel Bouanane-Darenfed, Kahina Hafid
Cucumisin [EC 3.4.21.25] was first purified from Cucumis melo var. reticulatus juice by three-phase partitioning (TPP). Optimum purification parameters of the TPP system were determined as 60% ammonium sulfate saturation with 1.0:1.25 ratio of crude extract: t-butanol at pH and temperature of 8.0 and 20°C, respectively. Cucumisin was purified with 4.61 purification fold and 156% activity recovery. The molecular weight of the recovered cucumisin was determined as 68.4kDa and its isoelectric point is 8.7. Optimum pH and temperature of cucumisin were pH 9...
April 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28428127/potassium-and-sodium-ions-enhance-the-activity-and-thermostability-of-1-4-%C3%AE-glucan-branching-enzyme-from-geobacillus-thermoglucosidasius-in-the-presence-of-glycerol
#14
Xiaofeng Ban, Abhishek S Dhoble, Caiming Li, Yuzhu Zhang, Zhengbiao Gu, Li Cheng, Yan Hong, Zhaofeng Li
Metal ions are essential for the performance of metal-dependent proteins and are known to be important for thermophilic proteins containing a large number of charged residues. The performance of thermophilic proteins may be influenced by metal ions through electrostatic interactions between the metal ions and charged residues. In this study, we investigated the effects of metal ions and glycerol on the activity and stability of the thermophilic 1,4-α-glucan branching enzyme (abbreviated GBE; EC 2.4.1.18) from G...
April 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28428126/interactions-of-tetracyclines-with-ovalbumin-the-main-allergen-protein-from-egg-white-spectroscopic-and-electrophoretic-studies
#15
Maria Dayanne de A Dantas, Humberto de Araújo Tenório, Thiago Inácio B Lopes, Hugo Juarez V Pereira, Anita J Marsaioli, Isis M Figueiredo, Josué Carinhanha Caldas Santos
The interactions of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) with ovalbumin (OVA), the main allergen protein of egg white, were investigated by molecular spectroscopy and electrophoresis at three pH conditions (1.5, 4.6 and 7.4). Molecular and synchronous fluorescence, UV-vis spectroscopy, electrophoresis and (1)H NMR were used to study the interaction process. Tetracyclines interact with ovalbumin fluorescence by a static quenching mechanism with non-fluorescent complex formation changing the native protein structure...
April 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28427888/dopamine-elevates-intracellular-zinc-concentration-in-cultured-rat-embryonic-cortical-neurons-through-the-camp-nitric-oxide-signaling-cascade
#16
Hui-Hsing Hung, Lung-Sen Kao, Pei-Shan Liu, Chien-Chang Huang, De-Ming Yang, Chien-Yuan Pan
Zinc ion (Zn(2+)), the second most abundant transition metal after iron in the body, is essential for neuronal activity and also induces toxicity if the concentration is abnormally high. Our previous results show that exposure of cultured cortical neurons to dopamine elevates intracellular Zn(2+) concentrations ([Zn(2+)]i) and induces autophagosome formation but the mechanism is not clear. In this study, we characterized the signaling pathway responsible for the dopamine-induced elevation of [Zn(2+)]i and the effect of [Zn(2+)]i in modulating the autophagy in cultured rat embryonic cortical neurons...
April 17, 2017: Molecular and Cellular Neurosciences
https://www.readbyqxmd.com/read/28427679/sonochemical-synthesis-and-characterization-of-microrod-to-nanoparticle-of-new-mixed-ligand-zinc-ii-fumarate-metal-organic-polymer
#17
Payam Abdolalian, Ali Morsali, Giuseppe Bruno
Micro and nano-structures of a new mixed-ligand Zn(II) fumarate metal-organic polymer, {[Zn(tptz)(fum)].DMF}n (1), (tptz=2,4,6-tris(2-pyridyl)-s-triazine, fum=fumarate, DMF=N,N-dimethylforamide), were synthesized by sonochemical method. These new micro and nano-structures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), IR spectroscopy and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction and consists of the primary unit of [Zn(tptz)(fum)]...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427653/thermolysis-synthesis-of-pure-phase-nio-from-novel-sonochemical-synthesized-ni-ii-nano-metal-organic-supramolecular-architecture
#18
Younes Hanifehpour, Ali Morsali, Babak Mirtamizdoust, Sang Woo Joo, Behzad Soltani
Nano-structures of a new supramolecular coordination compound of divalent nickel with the pyrazol (pzH) containing the terminal azide anions, [Ni(pzH)2(N3)2] (1), with discrete molecular architecture (DMA) in solid state was synthesized via sonochemical method. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, IR, and elemental analysis. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal X-ray data shows that the coordination number of Ni (II) ions is six, (NiN6), with four N-donor atoms from neutral "pzH" ligands and two N-donors from two terminal azide anions...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427628/ultrasonic-energy-enhanced-the-efficiency-of-advance-extraction-methodology-for-enrichment-of-trace-level-of-copper-in-serum-samples-of-patients-having-neurological-disorders
#19
Mariam S Arain, Tasneem G Kazi, Hassan I Afridi, Jamshed Ali, Asma Akhtar
An innovative dual dispersive ionic liquid based on ultrasound assisted microextraction (UDIL-μE), for the enrichment of trace levels of copper ion (Cu(2+)), in serum (blood) of patients suffering from different neurological disorders. The enriched metal ions were subjected to flame atomic absorption spectrometry (FAAS). In the UDIL-μE method, the extraction solvent, ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was dispersed into the aqueous samples using an ultrasonic bath...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427261/hot-hole-photoelectrochemistry-on-au-sio2-au-nanoparticles
#20
Andrea E Schlather, Alejandro Manjavacas, Adam Lauchner, Valeria Spolon Marangoni, Christopher J DeSantis, Peter Nordlander, Naomi J Halas
There is currently a worldwide need to develop efficient photocatalytic materials that can reduce the high energy cost of common industrial chemical processes. One possible solution focuses on metallic nanoparticles (NPs) that can act as efficient absorbers of light due to their surface plasmon resonance. Recent work indicates that small NPs, when photoexcited, may allow for efficient electron or hole transfer necessary for photocatalysis. Here we investigate the mechanisms behind hot hole carrier dynamics by studying the photo-driven oxidation of citrate ions on Au@SiO2@Au core-shell nanoparticles...
April 20, 2017: Journal of Physical Chemistry Letters
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