bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous Analysis of Oil-Soluble, Basic, and Acidic Illegal Dyes in Foods Using Liquid Chromatography–Diode-Array Detection
Authors: Uematsu Yoko , Mizumachi Toshiko , Monma Kimio 
Published: February 2017

Abstract
A method for simutaneously detecting 8 oil-soluble and 10 water-soluble (3 basic and 7 acidic) illegal dyes in foods was developed. The sample was mixed with water, followed by methanol and tetrahydrofuran. Transesterification with sodium methoxide was applied to the mixture, which allowed the triglycerides in the sample to be converted to fatty acid methyl esters. This treatment resulted in a biphasic mixture. Oil-soluble dyes and fatty acid methyl esters were deposited in the upper organic phase, which was cleaned using a silica-gel solid-phase extraction (SPE) column to remove the fatty acid methyl esters from the solution. The water-soluble dyes were deposited in the aqueous phase, and an Oasis hydrophilic–lipophilic-balanced SPE column was used to remove polar matrix components from the solution. The resulting dyes were subsequently analyzed via LC–diode-array detection using a single method. The practical LODs of the samples were defined as the lowest spiked dye concentrations at which the similarity coefficient for the spectra of the LC test solution and the corresponding reference standard solution were greater than 0.99, thus affording LODs of 0.5–1.0 µg/g. Recoveries of the dyes at a spiking level of 5.0 µg/g from soft drink, chili sauce, and mustard were generally greater than 70%. Recoveries from paprika powder were between 33 and 103%.
Factors controlling the evaporation of secondary organic aerosol from α‐pinene ozonolysis
Authors: Yli‐Juuti Taina , Pajunoja Aki , Tikkanen Olli‐Pekka , Buchholz Angela , Faiola Celia , Väisänen Olli , Hao Liqing , Kari Eetu , Peräkylä Otso , Garmash Olga , Shiraiwa Manabu , Ehn Mikael , Lehtinen Kari , Virtanen Annele 
Published: February 2017

AbstractSecondary organic aerosols (SOA) forms a major fraction of organic aerosols in the atmosphere. Knowledge of SOA properties that affect their dynamics in the atmosphere is needed for improving climate models. By combining experimental and modeling techniques, we investigated the factors controlling SOA evaporation under different humidity conditions. Our experiments support the conclusion of particle phase diffusivity limiting the evaporation under dry conditions. Viscosity of particles at dry conditions was estimated to increase several orders of magnitude during evaporation, up to 109 Pa s. However, at atmospherically relevant relative humidity and time scales, our results show that diffusion limitations may have a minor effect on evaporation of the studied α‐pinene SOA particles. Based on previous studies and our model simulations, we suggest that, in warm environments dominated by biogenic emissions, the major uncertainty in models describing the SOA particle evaporation is related to the volatility of SOA constituents.
Spatial variability of soil N2O and CO2 fluxes in different topographic positions in a tropical montane forest in Kenya
Authors: Arias‐Navarro C. , Díaz‐Pinés E. , Klatt S. , Brandt P. , Rufino M. C. , Butterbach‐Bahl K. , Verchot L. V. 
Published: February 2017

AbstractQuantifying and understanding the small‐scale variability of nitrous oxide (N2O) and carbon dioxide (CO2) emission are essential for reporting accurate ecosystem greenhouse gas budgets. The objective of this study was to evaluate the spatial pattern of soil CO2 and N2O emissions and their relation to topography in a tropical montane forest. We measured fluxes of N2O and CO2 from 810 sampling locations across valley bottom, midslope, and ridgetop positions under controlled laboratory conditions. We further calculated the minimum number of samples necessary to provide best estimates of soil N2O and CO2 fluxes at the plot level. Topography exhibited a major influence on N2O emissions, with soils at midslope position emitting significantly less than at ridgetops and valley bottoms, but no consistent effect of topography on soil CO2 emissions was found. The high spatial variation of N2O and CO2 fluxes was further increased by changes in vegetation and soil properties resulting from human disturbance associated with charcoal production. Soil N2O and CO2 fluxes showed no spatial pattern at the plot level, with “hot spots” strongly contributing to the total emissions (10% of the soil cores represented 73 and 50% of the total N2O and CO2 emissions, respectively). Thus, a large number of samples are needed to obtain robust estimates of N2O and CO2 fluxes. Our results highlight the complex biogeochemical cycling in tropical montane forests, and the need to carefully address it in research experiments to robustly estimate soil CO2 and N2O fluxes at the ecosystem scale.
Newly diagnosed immune thrombocytopenia adults: Clinical epidemiology, exposure to treatments, and evolution. Results of the CARMEN multicenter prospective cohort
Authors: Moulis Guillaume , Germain Johanne , Comont Thibault , Brun Natacha , Dingremont Claire , Castel Brice , Arista Sophie , Sailler Laurent , Lapeyre‐Mestre Maryse , Beyne‐Rauzy Odile , Godeau Bertrand , Adoue Daniel ,   The CARMEN Investigators Group
Published: February 2017

AbstractThe clinical epidemiology of immune thrombocytopenia (ITP) is not well known in adults. This study was aimed at assessing the clinical epidemiology of incident ITP adults, the factors associated with chronicity and exposure to treatments. This study was conducted in the CARMEN registry, a multicentric prospective cohort aimed at including all newly diagnosed ITP adults in the French Midi‐Pyrénées region, South of France (3 million inhabitants) from June 2013. Descriptive analyses and multivariate logistic regression models were conducted. Out of 121 newly diagnosed ITP until December 2014, 113 patients were followed in the region and gave informed consent. Median age was 65 years. Half of the patients were female, 20.3% had a secondary ITP, 50.4% had a Charlson's score ≥1, median platelet count was 17 × 109/L; 50.9% had bleeding symptoms, including 2 severe gastrointestinal tract and 1 intracranial bleedings; 21.4% had another autoimmune disease and 20.3% experienced an infection within the six weeks before ITP onset. Persistency and chronicity rates were 68.2% and 58.7%, respectively. Antinuclear antibodies were associated with chronicity (OR: 2.89, 95% CI: 1.08‐7.74). Sixty‐eight (60.2%) patients were treated during the week following the diagnosis. Factors associated with the use of intravenous corticosteroids were secondary ITP and high bleeding score. Those associated with the use of intravenous immunoglobulin (IVIg) were a high bleeding score and low platelet count. In conclusion, severe bleeding is rare at ITP onset. Associated autoimmune diseases and recent infections were frequent. Antinuclear antibodies seem predictors of chronicity. Intravenous corticosteroids and IVIg were frequently used.
Measuring material wealth in low‐income settings: A conceptual and how‐to guide
Authors: Kaiser Bonnie N. , Hruschka Daniel , Hadley Craig 
Published: February 2017

AbstractAlthough wealth is consistently found to be an important predictor of health and well‐being, there remains debate as to the best way to conceptualize and operationalize wealth. In this article, we focus on the measurement of economic resources, which is one among many forms of wealth. We provide an overview of the process of measuring material wealth, including theoretical and conceptual considerations, a how‐to guide based on the most common approach to measurement, and a review of important theoretical and empirical questions that remain to be resolved. Throughout, we emphasize considerations particular to the settings in which anthropologists work, and we include variations on common approaches to measuring material wealth that might be better suited to anthropologists' theoretical questions, methodological approaches, and fieldwork settings.
Pseudogap in the Eliashberg approach based on electron‐phonon and electron‐electron‐phonon interaction
Authors: Szczȩśniak R. , Durajski A. P. , Duda A. M. 
Published: February 2017

The properties of the superconducting and the anomalous normal state were described by using the Eliashberg method. The pairing mechanism was reproduced with the help of the Hamiltonian, which models the electron‐phonon and the electron‐electron‐phonon interaction (EEPh). The set of the Eliashberg equations, which determines the order parameter function (φ), the wave function renormalization factor (Z), and the energy shift function (χ), was derived. It was proven that for the sufficiently large values of the EEPh potential, the doping dependence of the order parameter () has the analogous course to that observed experimentally in cuprates. The energy gap in the electron density of states is induced by Z and χ ‐ the contribution from φ is negligible. The electron density of states possesses the characteristic asymmetric form and the pseudogap is observed above the critical temperature.
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Elastic wave transport in disordered, isotropic media: a supersymmetric sigma model
Authors: Photiadis Douglas M. 
Published: February 2017

Starting from a continuum description of a disordered elastic medium, we have derived a supersymmetric field theoretic model enabling the prediction of ensemble average correlation functions that fully takes polarization effects into account. The model enables both perturbative and non‐perturbative calculations in a similar fashion as corresponding models of disordered electronic systems. At intermediate distances, we show that a Hubbard‐Stratonovic transformation can be carried out and obtain a supermatrix field theory. At distances far greater than the mean free paths of the system, we show that the action reduces to a nonlinear supersymmetric sigma model formally identical to that for a scalar field. Our results yield a bare diffusion constant given by a density of states weighted average of the classical diffusion constants of the coherent potential approximation(CPA) medium.
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Catalytic Reaction Rates Controlled by Metal Oxidation State: C−H Bond Cleavage in Methane over Nickel‐Based Catalysts
Authors: Che Fanglin , Ha Su , McEwen Jean‐Sabin 
Published: February 2017

AbstractThe role of low concentrations of carbon complexes in hydrocarbon decomposition over transition metal surfaces has been a topic of much debate over the past decades. It is also a mystery as to whether or not electric fields can enhance hydrocarbon conversion in an electrochemical device at lower than normal reforming temperatures. To provide a “bottom‐up” fundamental insight, C−H bond cleavage in methane over Ni‐based catalysts was investigated. Our theoretical results show that the presence of carbon or carbide‐like species at the interface between the Ni cluster and its metal‐oxide support, as well as the application of an external positive electric field, can significantly increase the Ni oxidation state. Furthermore, the first C−H bond cleavage in methane is favored as the local oxidation state of Ni increases. Thus, the presence of a low concentration of carbon species, or the addition of a positive electric field will improve the hydrocarbon activation process.
Catalytic Enantioselective γ‐Selective Additions of 2‐Allylazaarenes to Activated Ketones
Authors: Bai Xiangbin , Zeng Guangkuo , Shao Tianju , Jiang Zhiyong 
Published: February 2017

AbstractReported herein is the first example of 2‐allylazaarenes in asymmetric catalysis. Highly γ‐selective allylation was demonstrated for activated ketones, including isatins and trifluoromethyl ketones. In the presence of either an amino‐acid‐based tertiary amine or quaternary ammonium salt catalyst, two series of tertiary hydroxy‐containing moieties were installed at the remote δ‐position of azaarenes in good chemical yields, excellent enantioselectivities, and E/Z ratios. The success of current γ‐selective reactions should provide inspiration for expansion to other allylazaarene derivatives and would open up new paradigms for the synthesis of chiral γ‐ and/or δ‐functionalized azaarenes.
Enantioselective Reactions of 2‐Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho‐Quinone Methide Intermediates
Authors: Chen Ping , Wang Kai , Guo Wengang , Liu Xianghui , Liu Yan , Li Can 
Published: February 2017

AbstractWe report herein a dynamic kinetic resolution (DKR) involving ortho‐quinone methide (o‐QM) intermediates. In the presence of Et3N and the cinchonine‐derived nucleophilic catalyst D, the DKR of 2‐sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57–79 % yield with good to excellent enantioselectivity (85–95 % ee). Furthermore, with 2‐(tosylmethyl)sesamols or 2‐(tosylmethyl)naphthols, from which stable o‐QM substrates can be generated, a formal [4+2] cycloaddition delivered 4‐aryl‐ or alkyl‐substituted chromans with excellent enantioselectivity (88–97 % ee).
An Intramolecular Silylene Borane Capable of Facile Activation of Small Molecules, Including Metal‐Free Dehydrogenation of Water
Authors: Mo Zhenbo , Szilvási Tibor , Zhou Yu‐Peng , Yao Shenglai , Driess Matthias 
Published: February 2017

AbstractThe first single‐component N‐heterocyclic silylene borane 1 (LSi‐R‐BMes2; L=PhC(NtBu)2; R=1,12‐xanthendiyl spacer; Mes=2,4,6‐Me3C6H2), acting as a frustrated Lewis pair (FLP) in small‐molecule activation, can be synthesized in 65 % yields. Its HOMO is largely localized at the silicon(II) atom and the LUMO has mainly boron 2p character. In small‐molecule activation 1 allows access to the intramolecular silanone–borane 3 featuring a Si=O→B interaction through reaction with O2, N2O, or CO2, and formation of silanethione borane 4 from reaction with S8. The SiII center in 1 undergoes immediate hydrogenation if exposed to H2 at 1 atm pressure in benzene, affording the silane borane 5‐H2, L(H2)Si‐R‐BMes2. Remarkably, no H2 activation occurs if the single silylene LSiPh and Mes3B intermolecularly separated are exposed to dihydrogen. Unexpectedly, the pre‐organized Si–B separation in 1 enables a metal‐free dehydrogenation of H2O to give the silanone–borane 3 as reactive intermediate.
Formation of Gas‐Phase Formate in Thermal Reactions of Carbon Dioxide with Diatomic Iron Hydride Anions
Authors: Jiang Li‐Xue , Zhao Chongyang , Li Xiao‐Na , Chen Hui , He Sheng‐Gui 
Published: February 2017

AbstractThe hydrogenation of carbon dioxide involves the activation of the thermodynamically very stable molecule CO2 and formation of a C−H bond. Herein, we report that HCO2− and CO can be formed in the thermal reaction of CO2 with a diatomic metal hydride species, FeH−. The FeH− anions were produced by laser ablation, and the reaction with CO2 was analyzed by mass spectrometry and quantum‐chemical calculations. Gas‐phase HCO2− was observed directly as a product, and its formation was predicted to proceed by facile hydride transfer. The mechanism of CO2 hydrogenation in this gas‐phase study parallels similar behavior of a condensed‐phase iron catalyst.
Photofunctionality in Porphyrin‐Hybridized Bis(dipyrrinato)zinc(II) Complex Micro‐ and Nanosheets
Authors: Sakamoto Ryota , Yagi Toshiki , Hoshiko Ken , Kusaka Shinpei , Matsuoka Ryota , Maeda Hiroaki , Liu Zheng , Liu Qian , Wong Wai‐Yeung , Nishihara Hiroshi 
Published: February 2017

AbstractNew bis(dipyrrinato)zinc(II) complex micro‐ and nanosheets containing zinc(II) porphyrin (N2) are synthesized. A liquid/liquid interface method between dipyrrin porphyrin ligand L2 and zinc acetate produces N2 with a large domain size. N2 can be layered quantitatively onto a flat substrate by a modified Langmuir–Schäfer method. N2 deposited on a SnO2 electrode functions as a photoanode for a photoelectric conversion system. The photoresponse of N2 covers the whole visible wavelength range (400–650 nm), with a maximum quantum efficiency of more than twice that of a bis(dipyrrinato)zinc(II) complex nanosheet without porphyrin.
Parametric investigation of polymethacrylate monolith synthesis and stability via thermogravimetric characterisation
Authors: Acquah Caleb , Danquah Michael K. , Moy Charles K. S. , Anwar Mahmood , Ongkudon Clarence M. 
Published: February 2017

AbstractPolymethacrylate monoliths are synthetic adsorbents with macroporous and mesoporous interconnected channels that can be engineered to target the hydrodynamic features of a wide range of molecular species. However, rigorous study into the effect of synthesis conditions on their thermal stability is limited. This work attempts to characterise the influence of key synthesis process variables on the stability of polymethacrylate monoliths using thermogravimetric analysis at a heating rate of 10 °C/min. Experimental results showed that the thermal stability of polymethacrylate monoliths increased with decreasing polymerisation temperature from 85 to 65 °C. Increasing the total porogen (P) to monomer (M) ratio increased the thermal stability of the monolith by >62% and >50% for P40/M60–P60/M40 and P60/M40–P80/M20, respectively. The impact of the initiator concentration, monomer variation, biporogen ratio, washing and activation of the monoliths was investigated. Nuclear magnetic resonance analyses conducted confirmed the hydrolysis of epoxy moieties on the monolith. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of vasomodulators and tumor transplantation on the disposition of 5‐fluorouracil after application to the liver surface in rats
Authors: Kodama Yukinobu , Horishita Miyuki , Tokunaga Ayako , Miyamoto Hirotaka , Fumoto Shintaro , Sasaki Hitoshi , Nakamura Junzo , Nishida Koyo 
Published: February 2017

AbstractThis study investigated the effect of epinephrine (a vasoconstrictor) and hydralazine (a vasodilator) on the hepatic disposition of 5‐fluorouracil (5‐FU) after application to the surface of the liver in rats. Normal livers were compared with a Walker 256 carcinoma cell tumor model. A cylindrical diffusion cell was attached to the liver surface. 5‐Fluorouracil was added into the diffusion cell in combination with vasomodulators or after pretreatment with epinephrine. After selected treatment times, the 5‐FU concentrations were assayed at three sites in the excised livers. The 5‐FU concentration in the region under the cell attachment site (site 1) was significantly higher after concomitant application of 5‐FU and epinephrine, compared with 5‐FU alone, and increased in an epinephrine dose‐dependent manner. On the other hand, preferential distribution of 5‐FU at site 1 was not seen when applied in combination with hydralazine. After 10 min of epinephrine pretreatment, the concentration of 5‐FU at site 1 was approximately two times higher than that for the control. Furthermore, the 5‐FU concentration at site 1 of the tumor model was greatly increased compared with the normal liver. These results suggest that application of epinephrine to the liver surface might enhance the accumulation of 5‐FU at the desired target site.
Anchored Fe3O4 Nanoparticles on rGO Nanosheets as High‐Power Negative Electrodes for Aqueous Batteries
Authors: Sanchez Jaime S. , Pendashteh Afshin , Palma Jesus , Anderson Marc , Marcilla Rebeca 
Published: February 2017

AbstractFe3O4 nanoparticles were anchored on GO nanosheets and evaluated as negative electrode materials for high‐performance aqueous batteries. The prepared samples were characterized by using XRD, Raman spectroscopy, TGA, and TEM. The energy‐storage behavior of the samples was investigated by testing high‐mass‐loaded (ca. 8.5 mg ⋅ cm−2) Fe3O4−rGO electrodes with different electrochemical techniques, including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The nanocomposites showed better electrochemical storage properties than pure Fe3O4 nanoparticles and rGO nanosheets, suggesting superior performance through synergistic effects. Accordingly, the Fe3O4−rGO nanocomposite with an optimized composition of [60 : 40] showed a maximum capacity of 402 C ⋅ g−1 (111.6 mA ⋅ h ⋅ g−1) and superior rate capability (ca. 40 % capacity retention with a 20‐fold increase in scan rate) compared to the pure oxide. To further evaluate the applicability of the Fe3O4−rGO nanocomposite, aqueous batteries based on the Fe3O4−rGO [60 : 40] nanocomposite as negative electrodes and NiCoMnO4 as positive electrodes were assembled and examined by using various electrochemical techniques. Fe3O4−rGO//NiCoMnO4 cells demonstrated a maximum specific energy of 26 Wh ⋅ kg−1 and a maximum specific power of 6.8 kW ⋅ kg−1, with a desirable rate capability. All of the obtained results suggest the Fe3O4−rGO nanocomposite as a promising negative electrode material for high‐power aqueous batteries.
On the Way to a Trisanionic {Cu3O2} Core for Oxidase Catalysis: Evidence of an Asymmetric Trinuclear Precursor Stabilized by Perfluoropinacolate Ligands
Authors: Hannigan Steven F. , Arnoff Amanda I. , Neville Sarah E. , Lum June S. , Golen James A. , Rheingold Arnold L. , Orth Nicole , Ivanović‐Burmazović Ivana , Liebhäuser Patricia , Rösener Thomas , Stanek Julia , Hoffmann Alexander , Herres‐Pawlis Sonja , Doerrer Linda H. 
Published: February 2017

AbstractCuI complexes of the form K[(R3P)Cu(pinF)], in which (pinF)2− is the bidentate, oxygen‐donating ligand perfluoropinacolate, were synthesized and characterized. Low‐temperature oxygenation of the K[(R3P)Cu(pinF)(PR3)] species resulted in a trisanionic bis(μ3‐oxo) trinuclear copper(II,II,III) core characterized by UV/Vis spectroscopy (λmax [nm] = 330, 535, 630), cryospray‐ionization mass spectrometry, and X‐band electron paramagnetic resonance spectroscopy (derivative resonance at 3300 G, Δms=2 at 1500 G). The kinetic behavior of the trimeric {Cu3O2} species was quantified by stopped‐flow spectroscopy and the associated electronic structures were investigated by DFT calculations. An asymmetric {Cu3O2} species, AsTpinF, which bears a structure similar to multicopper oxidases, forms prior to full formation of the symmetric trinuclear core, SyTpinF. The trimer catalytically oxidizes para‐hydroquinone to benzoquinone (a form of oxidase chemistry).
Visible and Near‐IR Emissions from k2N‐ and k3N‐Terpyridine Rhenium(I) Assemblies Obtained by an [n×1] Head‐to‐Tail Bonding Strategy
Authors: Laramée‐Milette Baptiste , Zaccheroni Nelsi , Palomba Francesco , Hanan Garry S. 
Published: February 2017

AbstractAn [n×1] head‐to‐tail bonding strategy has been used for the synthesis of ReI metallacycles. From a k3N‐dicarbonyl precursor, a single discrete [4×1] square assembly was isolated and characterized, whereas a k2N‐tricarbonyl precursor led to two major species, a square and a [3×1] triangular assembly. Solid‐state X‐ray diffraction study has confirmed the high angular distortion (71° to 96°) of the k2N precursors. The electrochemical reversibility of the triangular (5) and square (6, 7) assemblies is increased with respect to that of their precursors. Photophysical investigation has confirmed pronounced red‐shifts in the emissions of the k3N‐dicarbonyl species 4 (935 nm) and 7 (980 nm), as confirmed by density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations.