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Copper T

Andrew W Schaefer, Matthew T Kieber-Emmons, Suzanne M Adam, Kenneth D Karlin, Edward I Solomon
This study evaluates the reaction of a biomimetic heme-peroxo-copper complex {[(DCHIm)(F8)FeIII]-(O22-)-[CuII(AN)]}+ (1) with a phenolic substrate, involving a net H-atom abstraction to cleave the bridging peroxo O-O bond that produces FeIV=O, CuII-OH and phenoxyl radical moieties, analogous to the chemistry carried out in heme-copper oxidases (HCOs). A 3D potential energy surface generated for this reaction reveals two possible reaction pathways: one involves nearly complete proton transfer from the phenol to the peroxo ligand before the barrier; the other involves O-O homolysis where the phenol remains H-bonding to the peroxo O(Cu) in the transition state, and transfers the proton after the barrier...
May 18, 2017: Journal of the American Chemical Society
Selim Doganay, Kazim Gumus, Gonca Koc, Ayse Kacar Bayram, Mehmet Sait Dogan, Duran Arslan, Hakan Gumus, Sureyya Burcu Gorkem, Saliha Ciraci, Halil Ibrahim Serin, Abdulhakim Coskun
OBJECTIVES: Wilson's disease (WD) is characterized with the accumulation of copper in the liver and brain. The objective of this study is to quantitatively measure the susceptibility changes of basal ganglia and brain stem of pediatric patients with neurological WD using quantitative susceptibility mapping (QSM) in comparison to healthy controls. METHODS: Eleven patients with neurological WD (mean age 15 ± 3.3 years, range 10-22 years) and 14 age-matched controls were prospectively recruited...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Camila Tureck, Gelvani Locateli, Vanesa Gesser Corrêa, Eloá Angélica Koehnlein
Introduction: The study of dietary antioxidants has gained prominence owing to the elucidation of the deleterious effects of oxidative stress to the human body. Objective: To evaluate the Brazilian population's intake of antioxidant nutrients and their association with the nutritional status. Methods: A cross-sectional study was carried out including secondary data on food consumption of 33,459 individuals from both sexes, aged 10 years or older, from all Brazilian regions based on microdata of the "2008-2009 Household Budget Survey, Brazilian Dairy Survey...
January 2017: Revista Brasileira de Epidemiologia, Brazilian Journal of Epidemiology
Mariana de Barros, Pedro Griffo Perciano, Marcelo Henrique Dos Santos, Leandro Licursi De Oliveira, Éderson D'Martin Costa, Maria Aparecida Scatamburlo Moreira
Mastitis is an inflammation of mammary gland parenchyma that adversely affects bovine health and dairy production worldwide despite significant efforts to eradicate it. The aim of this work was to characterize the antimicrobial activity of 7-epiclusianone (7-epi), a compound extracted from the Rheedia brasiliensis fruit, its complex with copper against Streptococcus spp. isolated from bovine mastitis, and to assess their cytotoxicity to bovine mammary alveolar cells (MAC-T). The complex 7-epiclusianone-Cu (7-epi-Cu) was an amorphous green solid with optical activity...
May 17, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Stig D Friis, Michael T Pirnot, Lauren N Dupuis, Stephen L Buchwald
We report an efficient means of sp(2) -sp(3) cross coupling for a variety of terminal monosubstituted olefins with aryl electrophiles using Pd and CuH catalysis. In addition to its applicability to a range of aryl bromide substrates, this process was also suitable for electron-deficient aryl chlorides, furnishing higher yields than the corresponding aryl bromides in these cases. The optimized protocol does not require the use of a glovebox and employs air-stable Cu and Pd complexes as precatalysts. A reaction on 10 mmol scale further highlighted the practical utility of this protocol...
May 16, 2017: Angewandte Chemie
A Pechová, T Husáková, L Pavlata, M Holasová, K Hauptmanová
This study was performed with the aim of investigating the concentration of zinc and copper in the blood of healthy alpacas (Vicugna pacos) kept in central Europe and to compare the concentration of Zn and Cu in plasma and in whole blood. A further objective was to evaluate blood Zn and Cu in relation to different micromineral supplementation, age and sex groups of alpacas. A total of 299 alpacas (224 adults and 75 crias) from 18 farms were included in this study. The concentrations of copper and zinc in plasma/whole blood were measured by flame atomic absorption spectrometry...
May 15, 2017: Biological Trace Element Research
Kanako Nakamae, Miho Tanaka, Bunsho Kure, Takayuki Nakajima, Yasuyuki Ura, Tomoaki Tanase
A copper hydride cluster [Cu8(μ-H)6(μ-dppm)5](PF6)2 (dppm = bis(diphenylphosphino)methane) was prepared from reaction of [CuH(PPh3)]6 with dppm in the presence of [Cu(CH3CN)4]PF6 and exhibited fluxional behaviors in solution where the hydrides and the phosphines are scrambling around the trans-bicapped octahedral Cu8 framework. The Cu8H6 complex showed facile reactivity with CO2 (1 atm, r.t.) to afford a tricopper complex, [Cu3(μ-H)(μ-O2CH)(μ-dppm)3]PF6, which could be developed to unprecedented hydrosilylation of CO2 catalyzed by multinuclear CuH species under mild conditions...
May 10, 2017: Chemistry: a European Journal
Sarah Frisco, Danny Liu, Arjun Kumar, Jay F Whitacre, Corey T Love, Karen Swider-Lyons, Shawn Litster
While some commercially available primary batteries have lithium metal anodes, there has yet to be a commercially viable secondary battery with this type of electrode. Research prototypes of these cells typically exhibit a limited cycle life before dendrites form and cause internal cell shorting, an occurrence that is more pronounced during high rate cycling. To better understand the effects of high rate cycling that can lead to cell failure, we use ex-situ nano-scale resolution X-ray computed tomography (nano-CT) with the aid of Zernike phase contrast to image the internal morphologies of lithium metal electrodes on copper wire current collectors that have been cycled at low and high current densities...
May 9, 2017: ACS Applied Materials & Interfaces
Oded Godsi, Gefen Corem, Yosef Alkoby, Joshua T Cantin, Roman V Krems, Mark F Somers, Jörg Meyer, Geert-Jan Kroes, Tsofar Maniv, Gil Alexandrowicz
The outcome of molecule-surface collisions can be modified by pre-aligning the molecule; however, experiments accomplishing this are rare because of the difficulty of preparing molecules in aligned quantum states. Here we present a general solution to this problem based on magnetic manipulation of the rotational magnetic moment of the incident molecule. We apply the technique to the scattering of H2 from flat and stepped copper surfaces. We demonstrate control of the molecule's initial quantum state, allowing a direct comparison of differences in the stereodynamic scattering from the two surfaces...
May 8, 2017: Nature Communications
T Jency Mohan, D Bahulayan
A highly efficient "Click with MCR" strategy for the three-step synthesis of two types of blue emitting chromene peptidomimetics is described. The peptidomimetics were synthesized via a copper-catalyzed [3[Formula: see text]2] azide-alkyne cycloaddition between chromene alkynes obtained from a three-component reaction and the peptide azides obtained from Ugi or Mannich type multicomponent reactions. The photophysical properties of the peptidomimetics are comparable with commercial fluorophores. Computational studies using drug property descriptors support the possibility of using these molecules for modulating difficult target classes having large, flat, and groove-shaped binding sites...
May 6, 2017: Molecular Diversity
V M Manikandamathavan, M Thangaraj, T Weyhermuller, R P Parameswari, V Punitha, N Narasimha Murthy, Balachandran Unni Nair
Two mononuclear copper (II) terpyridine complexes namely, [Cu(Btptpy) (ClO4)](ClO4) 1, and [Cu(Bttpy) (ClO4)](ClO4) 2, (Btptpy (L1) = 4'-(Benzothiophene)-2,2':6',2″-terpyridine, Bttpy (L2) = 4'-(Benzylthiazolyl)-2,2':6',2″-terpyridine) have been synthesized and characterized. Single crystal X-ray diffraction shows that, both ligands belong to monoclinic crystal system with space group P21/c (L1) and P21/n (L2). Absorption spectral titration, DNA melting study, circular dichroism and viscosity measurement reveal that, complex 1 and 2 bind with DNA through intercalation...
April 15, 2017: European Journal of Medicinal Chemistry
Paul T Bremer, Sabine Pellett, James P Carolan, William H Tepp, Lisa M Eubanks, Karen N Allen, Eric A Johnson, Kim D Janda
Botulinum neurotoxin serotype A (BoNT/A) causes a debilitating and potentially fatal illness known as botulism. The toxin is also a bioterrorism threat, yet no pharmacological antagonist to counteract its effects has reached clinical approval. Existing strategies to negate BoNT/A intoxication have looked to antibodies, peptides, or organic small molecules as potential therapeutics. In this work, a departure from the traditional drug discovery mindset was pursued, in which the enzyme's susceptibility to metal ions was exploited...
May 19, 2017: Journal of the American Chemical Society
Yuichi Ota, Kozo Okazaki, Haruyoshi Q Yamamoto, Takashi Yamamoto, Shuntaro Watanabe, Chuangtian Chen, Masanori Nagao, Satoshi Watauchi, Isao Tanaka, Yoshihiko Takano, Shik Shin
We investigate the superconducting-gap anisotropy in one of the recently discovered BiS_{2}-based superconductors, NdO_{0.71}F_{0.29}BiS_{2} (T_{c}∼5  K), using laser-based angle-resolved photoemission spectroscopy. Whereas the previously discovered high-T_{c} superconductors such as copper oxides and iron-based superconductors, which are believed to have unconventional superconducting mechanisms, have 3d electrons in their conduction bands, the conduction band of BiS_{2}-based superconductors mainly consists of Bi 6p electrons, and, hence, the conventional superconducting mechanism might be expected...
April 21, 2017: Physical Review Letters
R Lavanya, T Gomathi, K Vijayalakshmi, M Saranya, P N Sudha, Sukumaran Anil
In the present work, the maleic anhydride and methacrylic acid monomers were grafted one after another onto chitosan by using ceric ammonium nitrate as the initiator. The optimum conditions for grafting were studied by varying the initiator concentration, monomer concentration and reaction temperature. The synthesized grafted samples were subjected to various analytical techniques such as FTIR, XRD, TGA and DSC methods The proof of formation of graft copolymer was ascertained from the results of FTIR analysis and XRD studies...
May 1, 2017: International Journal of Biological Macromolecules
K M Polyakov, S Gavryushov, S Ivanova, T V Fedorova, O A Glazunova, A N Popov, O V Koroleva
The laccase from Steccherinum murashkinskyi is a member of the large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates, accompanied by the reduction of dioxygen to water. The reducing properties of X-ray radiation and the high quality of the laccase crystals allow the study of the catalytic reduction of dioxygen to water directly in a crystal. A series of diffraction data sets with increasing absorbed radiation dose were collected from a single crystal of Steccherinum murashkinskyi laccase at 1...
May 1, 2017: Acta Crystallographica. Section D, Structural Biology
Abolghasem Gus Bakhoda, Quan Jiang, Jeffery A Bertke, Thomas R Cundari, Timothy H Warren
We report herein three new modes of reactivity between arylazides N3 Ar with a bulky copper(I) β-diketiminate. Addition of N3 Ar(X3) (Ar(X3) =2,4,6-X3 C6 H2 ; X=Cl or Me) to [(i) Pr2 NN]Cu(NCMe) results in triazenido complexes from azide attack on the β-diketiminato backbone. Reaction of [(i) Pr2 NN]Cu(NCMe) with bulkier azides N3 Ar leads to terminal nitrenes [(i) Pr2 NN]Cu]=NAr that dimerize via formation of a C-C bond at the arylnitrene p-position to give the dicopper(II) diketimide 4 (Ar=2,6-(i) Pr2 C6 H3 ) or undergo nitrile insertion to give diazametallocyclobutene 8 (Ar=4-Ph-2,6-iPr2 C6 H2 )...
May 4, 2017: Angewandte Chemie
L F Prados, D F T Sathler, B C Silva, D Zanetti, S C Valadares Filho, H M Alhadas, E Detmann, S A Santos, L D S Mariz, M L Chizzotti
Weaned Nellore bulls ( = 36; 274 ± 34 kg) were used in a randomized block design with a 2 × 2 factorial arrangement of treatments to evaluate intake, fecal excretion, and performance with different concentrations of minerals. Experimental diets were formulated with 2 concentrations of Ca and P (macromineral factor; diet supplying 100% of Ca and P according to BR-CORTE () [CaP+] or diet without limestone and dicalcium phosphate [CaP-]) and 2 concentrations of microminerals (micromineral factor; diet with supplementation of microminerals [Zn, Mn, and Cu; CuMnZn+] or diet without supplementation of microminerals [Zn, Mn, and Cu; CuMnZn-])...
April 2017: Journal of Animal Science
D F T Sathler, L F Prados, D Zanetti, B C Silva, S C Valadares Filho, M V C Pacheco, P M Amaral, L N Rennó, M F Paulino
This study evaluated intake, microbial efficiency, and ruminal, small and large intestinal, and total digestibility of DM, OM, CP, and NDF, as well as availability of Ca, P, Mg, Na, K, Cu, Mn, and Zn in Zebu cattle fed with or without supplemental sources of Ca and P or a micromineral premix. Five rumen- and ileum-cannulated Nellore bulls (BW = 200 ± 10.5 kg; 9 mo) were used in the experiment, distributed in a 5 × 5 Latin square design. The experiment was developed in a 2 × 2 + 1 factorial design to measure the effects of mineral supplementation on intake, digestibility, and site of nutrient absorption...
April 2017: Journal of Animal Science
M Mustafa Cetin, Roman T Hodson, C Robin Hart, David B Cordes, Michael Findlater, Dominick J Casadonte, Anthony F Cozzolino, Michael F Mayer
The synthesis, characterization, photophysical properties, theoretical calculations, and catalytic applications of 2,9-di(aryl)-1,10-phenanthroline copper(i) complexes are described. Specifically, this study made use of di(aryl)-1,10-phenanthroline ligands including 2,9-di(4-methoxyphenyl)-1,10-phenanthroline (1), 2,9-di(4-hydroxyphenyl)-1,10-phenanthroline (2), 2,9-di(4-methoxy-3-methylphenyl)-1,10-phenanthroline (3), and 2,9-di(4-hydroxy-3-methylphenyl)-1,10-phenanthroline (4). The 2 : 1 ligand-to-metal complexes, as PF6(-) salts, i...
May 2, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Serena C Tarantino, Mattia Giannini, Michael A Carpenter, Michele Zema
Temperature and composition dependences of the I41/amd → [Formula: see text] phase transition in the Mg x Cu1 - x Cr2O4 spinel solid solution, due to the melting of the cooperative Jahn-Teller distortion, have been studied by means of single-crystal X-ray diffraction. Crystals with x = 0, 0.10, 0.18, 0.43, 0.46, 0.53, 1 were grown by flux decomposition methods. All crystals have been refined in the tetragonal I41/amd space group except for the Mg end-member, which has cubic symmetry. In Mg x Cu1 - x Cr2O4 the progressive substitution of the Jahn-Teller, d(9) Cu(2+) cation with spherical and closed-shell Mg(2+) has a substantial effect on the crystal structure, such that there is a gradual reduction of the splitting of a and c unit-cell parameters and flattening of the tetrahedra...
September 1, 2016: IUCrJ
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