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Julian Bejarano, Rainer Detsch, Aldo R Boccaccini, Humberto Palza
Novel multifunctional scaffolds for bone regeneration can be developed by incorporation of bioactive glasses doped with therapeutic and antibacterial metal ions, such as copper (Cu) and zinc (Zn), into a biodegradable polymer. In this context, porous composite materials of biodegradable poly(D, L-lactide) (PDLLA) mixed with sol-gel bioactive glasses (BG) of chemical composition 60SiO2 ; 25CaO; 11Na2 O; and 4P2 O5 (mol.%) doped with either 1 mol% of CuO or ZnO, and with both metals, were prepared. The cytocompatibility of the scaffolds on bone marrow stromal cells (ST-2) depended on both, the amount of glass filler and the concentration of metal ion, as evaluated by lactate dehydrogenase (LDH) activity, cell viability (water-soluble tetrazolium salt (WST-8)), and by cell morphology (scanning electron microscopy (SEM)) tests...
October 26, 2016: Journal of Biomedical Materials Research. Part A
Ethan P McMoran, Douglas R Powell, Felio Perez, Gerard T Rowe, Lei Yang
A series of copper complexes supported by a simple dipyridylamide ligand (H2pcp) were isolated and characterized. Treatment of H2pcp with NaH and copper(I) salts led to the formation of [Cu2(2pcp)2] (1a) and {Na[(Cu2(2pcp)2)2]PF6}n (1b). The X-ray crystal structures of both complexes feature Cu(I)Cu(I) cores with close Cu···Cu interactions. Electrochemical studies of 1a showed a reversible one-electron oxidation wave in CH2Cl2. On the basis of the work on 1a, we began studying the mixed-valence copper species supported by this ligand...
October 26, 2016: Inorganic Chemistry
Li Li, Zhiyuan Zhang
The emergence of bioorthogonal reactions has greatly broadened the scope of biomolecule labeling and detecting. Of all the bioorthogonal reactions that have been developed, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is the most widely applied one, mainly because of its relatively fast kinetics and high efficiency. However, the introduction of copper species to in vivo systems raises the issue of potential toxicity. In order to reduce the copper-induced toxicity and further improve the reaction kinetics and efficiency, different strategies have been adopted, including the development of diverse copper chelating ligands to assist the catalytic cycle and the development of chelating azides as reagents...
October 24, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Nimmy Kumar, Subhankar Biswas, Asha Elizabeth Mathew, Subin Varghese, Jessy Elizabeth Mathew, K Nandakumar, Jesil Mathew Aranjani, Richard Lobo
BACKGROUND: Hepatocellular carcinoma (HCC), the most common type of liver cancer accounts for more than one million deaths worldwide. Current treatment modality for HCC is marginally effective. Plants belonging to Mistletoe family (Loranthaceae) have been used in chemotherapy for many years. The present study was aimed at exploring the anti-proliferative, pro-oxidant and pro-apoptotic potential of stem of Elytranthe parasitica (L.) Danser (EP), a parasitic shrub belonging to Loranthaceae...
October 26, 2016: BMC Complementary and Alternative Medicine
Wonmo Kang, Iyoel Beniam, Siddiq M Qidwai
Electrically assisted deformation (EAD) is an emerging technique to enhance formability of metals by applying an electric current through them. Despite its increasing importance in manufacturing applications, there is still an unresolved debate on the nature of the fundamental deformation mechanisms underlying EAD, mainly between electroplasticity (non-thermal effects) and resistive heating (thermal effects). This status is due to two critical challenges: (1) a lack of experimental techniques to directly observe fundamental mechanisms of material deformation during EAD, and (2) intrinsic coupling between electric current and Joule heating giving rise to unwanted thermally activated mechanisms...
September 2016: Review of Scientific Instruments
C Zuber, S Bazzoli, P Brunel, J-P Fronty, D Gontier, C Goulmy, J Raimbourg, C Rubbelynck, C Trosseille
Streak cameras are widely used to record the spatio-temporal evolution of laser-induced plasma. A prototype of picosecond X-ray streak camera has been developed and tested by Commissariat à l'Énergie Atomique et aux Énergies Alternatives to answer the Laser MegaJoule specific needs. The dynamic range of this instrument is measured with picosecond X-ray pulses generated by the interaction of a laser beam and a copper target. The required value of 100 is reached only in the configurations combining the slowest sweeping speed and optimization of the streak tube electron throughput by an appropriate choice of high voltages applied to its electrodes...
September 2016: Review of Scientific Instruments
André Shamsabadi, Vijay Chudasama
Herein a review on the methods for the formation and reaction of acyl hydrazides will be given. There is particular focus on the synthesis of acyl hydrazides from aldehyde precursors with examination of the various approaches (e.g. metal-based (rhodium, copper) and non-metal-based (aerobically- and photoorganocatalytically-initiated)) that have been used to achieve this. Finally, strategies to utilise acyl hydrazides for the formation of an array of useful entities will be detailed.
October 26, 2016: Organic & Biomolecular Chemistry
Niklas O Thiel, Johannes F Teichert
An air-stable and preactivated copper(i) hydroxide/N-heteroyclic carbene (NHC) complex for alkyne semihydrogenations is reported. Next to an enhanced practicability of the process, the resulting alkenes are obtained with high Z-selectivities and no overreduction to the corresponding alkanes.
October 26, 2016: Organic & Biomolecular Chemistry
Maud Bollenbach, Patrick Wagner, Pedro G V Aquino, Jean-Jacques Bourguignon, Frédéric Bihel, Christophe Salomé, Martine Schmitt
A copper-catalyzed Ullmann-type amination with primary amines in water with a combination of copper(II) triflate [Cu(OTf)2 ], dipivaloylmethane, and d-glucose is reported. The mild conditions and the use of an inexpensive catalyst as well as a renewable feedstock (d-glucose and the surfactant TPGS-750-M, which is derived from vitamin E) make this protocol a safe and convenient strategy for efficient C-N bond formation. This easy-to-handle procedure is extremely competitive compared to palladium-based reactions and may be used to synthesize N-containing molecules, such as drugs or organic light-emitting diodes (OLEDs)...
October 26, 2016: ChemSusChem
Kiran Kumarvarma Chakrahari, Jian-Hong Liao, Samia Kahlal, Yu-Chiao Liu, Ming-Hsi Chiang, Jean-Yves Saillard, C W Liu
The first structurally characterized copper cluster with a Cu13 centered cuboctahedral arrangement, a model of the bulk copper fcc structure, was observed in [Cu13 (S2 CN(n) Bu2 )6 (C≡CR)4 ](PF6 ) (R=C(O)OMe, C6 H4 F) nanoclusters. Four of the eight triangular faces of the cuboctahedron are capped by acetylide groups in μ3  fashion, and each of the six square faces is bridged by a dithiolate ligand in μ2 ,μ2 fashion, which leads to a truncated tetrahedron of twelve sulfur atoms. DFT calculations are fully consistent with the description of these Cu13 clusters as two-electron superatoms, that is, a [Cu13 ](11+) core passivated by ten monoanionic ligands, with an a1 HOMO containing two 1S jellium electrons...
October 26, 2016: Angewandte Chemie
Chuan Li, Man Zhang, Qishan Chen, Yingying Li, Huiqi Gao, Wei Fu, Zhiming Zhou
A novel energetic heat-resistant explosive, 1-(3,5-dinitro-1H-pyrazol-4-yl)-3-nitro-1H-1,2,4-triazol-5-amine (HCPT), has been synthesized along with its salts. An intensive characterization of the compounds is given, including (1)H and (13)C NMR spectroscopy, IR spectroscopy, and elemental analysis. The crystal structures of neutral HCPT (3), its triaminoguanidinium salt (10), 3,4,5-triamino-1,2,4-triazolium salt (12), and copper(ii) complex (16) were determined by single-crystal X-ray diffraction. The physicochemical properties of the compounds, such as density, thermal stability, and sensitivity towards impact and friction were evaluated; all energetic compounds exhibited excellent thermal stabilities with decomposition temperatures ranging from 215 °C to 340 °C, and high positive heats of formation between 622...
October 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Farooq Khurum Shehzad, Ningning Qu, Yunshan Zhou, Lijuan Zhang, Huanyao Ji, Zonghai Shi, Jiaqi Li, Sadaf Ul Hassan
Composite films with the general formula (POM/CuTAPc)n derived from water-soluble Keggin-type polyoxometalates (POMs = H5PMo10V2O40, H4SiW12O40, H3PMo12O40 and H3PW12O40) and water-insoluble 4,9,16,23-copper tetraaminophthalocyanine (denoted CuTAPc) are successfully fabricated by a layer-by-layer self-assembly technique and systematically characterized. The structure of the polyoxometalate anions in the multilayers is kept intact; the deposition amounts of POM and CuTAPc remain constant in every adsorption cycle of the composite film assembly process...
October 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
F Farinella, L Maini, P P Mazzeo, V Fattori, F Monti, D Braga
Three copper(i) complexes have been obtained by the reaction of CuI with 3-picolylamine in acetonitrile solution and characterized by X-ray powder diffraction, both from synchrotron and laboratory radiation. Photophysical investigations in the solid state revealed highly efficient thermally-activated delayed fluorescence (TADF) with photoluminescence quantum yields (PLQYs) up to 18%. Notably, the complex [Cu2I2(3pica)]∞ displays a strong luminescence thermochromism due to the presence of both (1,3)(X + M)LCT excited states and a lower-lying cluster-centered ((3)CC) one, leading to multiple emission at room temperature; as a result, a white luminescence is achieved with a PLQY of 4...
October 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Peter Werner Roesky, Claude Kiefer, Sebastian Bestgen, Michael T Gamer, Michael Kühn, Sergei Lebedkin, Florian Weigend, Manfred M Kappes
Bis-phenylpropynyl-functionalized imidazolium salts and their corresponding gold and copper NHC complexes were prepared in order to investigate their potential application for the synthesis of heterometallic coinage metal compounds. By transmetallation reactions with different precious metal sources including copper and silver phenylacetylides [MCCPh]x (M = Cu, Ag), polynuclear molecules were obtained, which were further investigated for their photoluminescence properties. Additionally, one gold NHC complex was post-functionalized by autocatalytic hydration of the alkynyl side chains...
October 25, 2016: Chemistry: a European Journal
Martin Poryo, Sascha Meyer, Regina Eymann, Umut Yilmaz, Sogand Nemat, Tilman Rohrer
No abstract text is available yet for this article.
October 25, 2016: Neuropediatrics
Tetsuro Kikuchi, Manabu Fujii, Koumei Terao, Ran Jiwei, Ying Ping Lee, Chihiro Yoshimura
Chemical speciation, reactivity, and bioavailability of trace metals in aqueous systems arestrongly influenced by dissolved organic matter (DOM). DOM is a mixture of diverse components, so a range of organic molecules potentially participates in the occurrence of dissolved trace metals. In this study, we investigated water quality variables that influence dissolved trace metal concentrations in natural and effluent water systems with a particular attention given to the relationship between DOM optical properties and dissolved copper and iron concentrations...
October 22, 2016: Science of the Total Environment
Chayanon Ngambenjawong, Julio Marco B Pineda, Suzie H Pun
Peptide cyclization is a strategy used to improve stability and/or activity of peptides. The most commonly used cyclization method is disulfide bridge formation of cysteine-containing peptides as typically found in nature. Over the years, an increasing number of alternative chemistries for peptide cyclization with improved efficiency, kinetics, orthogonality, and stability have been reported. However, there has been less appreciation for the opportunity to fine-tune peptide activity via the diverse chemical entities introduced at the site of linkage by different cyclization strategies...
October 25, 2016: Bioconjugate Chemistry
J D Thiessen, E Shams, G Stortz, G Schellenberg, D Bishop, M S Khan, P Kozlowski, F Retière, V Sossi, C J Thompson, A L Goertzen
A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding...
November 21, 2016: Physics in Medicine and Biology
Alexander M Polgar, Chhatra B Khadka, Mahmood Azizpoor Fard, Brian Nikkel, Terrence O'Donnell, Tobias Neumann, Kiana Lahring, Kyle Thompson, Carolyn Cadogan, Florian Weigend, John F Corrigan
The first examples of gold(I) trimethylsilylchalcogenolate complexes were synthesized and their reactivity showcased in the preparation of a novel gold-copper-sulfur cluster [Au4Cu4S4(dppm)2] (dppm = bis(diphenylphosphino)methane). The unprecedented structural chemistry of this compound gives rise to interesting optoelectronic properties, including long-lived luminescence in the solid state. Through time-dependent density functional theory calculations, the emission is shown to originate from a charge transfer process facilitated by Au∙∙∙Cu metallophilic bonding...
October 24, 2016: Chemistry: a European Journal
Suchismita Das, Sunayana Goswami
The present study investigated the effect of copper on photosynthesis, antioxidant potential, and anatomical response of aquatic fern, Salvinia cucullata, with a view to ascertain its phytoremediation potential. Plants were exposed in hydroponics for 21 days to different Cu concentrations (10, 15, 20, and 30 mg/L). Significant declines in chlorophyll, carotenoids, and soluble proteins, as a function of Cu proportion were observed. Lipid peroxidation was also evident, which implied reactive oxygen species (ROS) generation...
October 24, 2016: Environmental Science and Pollution Research International
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