bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatography/Tandem Mass Spectrometry Method To Determine Boldenone in Bovine Liver Tissues
Authors: Granja Rodrigo H M M , Salerno Alessandro G , de Lima Andreia C , Montalvo Cynthia , Reche Karine V G , Giannotti Fabio M , Wanschel Amarylis C B A 
Published: September 2014

Abstract
Boldenone, an androgenic steroid, is forbidden for use in meat production in most countries worldwide. Residues of this drug in food present a potential risk to consumers. A sensitive LC/MS/MS method for analysis of 17β-boldenone using boldenone-d3 as an internal standard was developed. An enzymatic hydrolysis and extraction using ethyl acetate, methanol, and hexane were performed in the sample preparation. Parameters such as decision limit (CCα), detection capability (CCβ), precision, recovery, and ruggedness were evaluated according to the Brazilian Regulation 24/2009 (equivalent to European Union Decision 2002/657/EC) and International Organization for Standardization/International Electrotechnical Commission 17025:2005. CCα and CCβ were determined to be 0.17 and 0.29 μg/kg, respectively. Average recoveries from bovine liver samples fortified with 1, 1.5, and 2 μg/kg were around 100%. A complete statistical analysis was performed on the results obtained, including an estimation of the method uncertainty. The method is considered robust after being subjected to day-to-day analytical variations and has been used as a standard method in Brazil to report boldenone levels in bovine liver.
Chemoselective Boronic Ester Synthesis by Controlled Speciation
Authors: Fyfe James W. B. , Seath Ciaran P. , Watson Allan J. B. 
Published: September 2014

AbstractControl of boronic acid solution speciation is presented as a new strategy for the chemoselective synthesis of boronic esters. Manipulation of the solution equilibria within a cross‐coupling milieu enables the formal homologation of aryl and alkenyl boronic acid pinacol esters. The generation of a new, reactive boronic ester in the presence of an active palladium catalyst also facilitates streamlined iterative catalytic CC bond formation and provides a method for the controlled oligomerization of sp2‐hybridized boronic esters.
Selective Carbon–Carbon Bond Cleavage for the Stereoselective Synthesis of Acyclic Systems
Authors: Marek Ilan , Masarwa Ahmad , Delaye Pierre‐Olivier , Leibeling Markus 
Published: September 2014

AbstractMost of the efforts of organic chemists have been directed to the development of creative strategies to build carbon–carbon and carbon–heteroatom bonds in a predictable and efficient manner. In this Review, we show an alternative approach where challenging molecular skeletons could be prepared through selective cleavage of carbon–carbon bonds. We demonstrate that it has the potential to be a general principle in organic synthesis for the regio‐, diastereo‐, and even enantioselective preparation of adducts despite the fact that CC single bonds are among the least reactive functional groups. The development of such strategies may have an impact on synthesis design and can ultimately lead to new selective and efficient processes for the utilization of simple hydrocarbons.
A Dual‐Color Far‐Red to Near‐Infrared Firefly Luciferin Analogue Designed for Multiparametric Bioluminescence Imaging
Authors: Jathoul Amit P. , Grounds Helen , Anderson James C. , Pule Martin A. 
Published: September 2014

AbstractRed‐shifted bioluminescent emitters allow improved in vivo tissue penetration and signal quantification, and have led to the development of beetle luciferin analogues that elicit red‐shifted bioluminescence with firefly luciferase (Fluc). However, unlike natural luciferin, none have been shown to emit different colors with different luciferases. We have synthesized and tested the first dual‐color, far‐red to near‐infrared (nIR) emitting analogue of beetle luciferin, which, akin to natural luciferin, exhibits pH dependent fluorescence spectra and emits bioluminescence of different colors with different engineered Fluc enzymes. Our analogue produces different far‐red to nIR emission maxima up to λmax=706 nm with different Fluc mutants. This emission is the most red‐shifted bioluminescence reported without using a resonance energy transfer acceptor. This improvement should allow tissues to be more effectively probed using multiparametric deep‐tissue bioluminescence imaging.
Effect of polymer structure on the morphologies and dielectric properties of nanoporous polyimide films
Authors: Lv Fengzhu , Liu Leipeng , Zhang Yihe , Li Penggang 
Published: September 2014

ABSTRACTLow dielectric constant polyimide (PI) films have potential applications in integrated circuit. In this study, poly(methyl methacrylate), poly(ethylene oxide), and polystyrene as thermally labile materials were used as templates to generate PI films with nanopores by first mixing the polymer templates with the precursor of PI, poly(amic acid), followed by imidization of poly(amic acid) together with degradation of the polymer templates. The sizes of the formed pores, the thermal and dielectric constant of the nanofoamed PI films were studied and compared in detail. It is concluded that the dielectric constant of PI films using poly(ethylene oxide) as pore template is more stable because of the formation of uniform pores which is from the great accordance of imidization temperature of poly(amic acid) with the degradation temperature of poly(ethylene oxide). But that using poly(methyl methacrylate) as pore template is frequency dependent as the influence of inhomogeneous pores and PMMA residue from incompletely degradation of poly(methyl methacrylate). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41480.
Effects of Nickel Oxide (NiO) nanoparticles on the performance characteristics of the jatropha oil based alkyd and epoxy blends
Authors: Gogoi Pronob , Saikia Bhaskar J. , Dolui Swapan K. 
Published: September 2014

ABSTRACTPlant oil based alkyd resin was prepared from jatropha oil and blended with epoxy resin. Subsequently, alkyd/epoxy/NiO nanocomposites with different wt % of NiO nanoparticles have been prepared by mechanical mixing of the designed components. The structure, morphology, and performance characteristics of the nanocomposites were studied by UV‐visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and universal testing machine (UTM). The alkyd/epoxy/NiO nanocomposites showed the gradual increase in thermal stability with increasing NiO content. With 3 wt % NiO content the tensile strength of the nanocomposite increased by 19 MPa (more than twofold) when compared with the pristine polymer. Limiting oxygen index (LOI) value of the nanocomposites indicate that the incorporation of NiO nanoparticles even in 1 wt % can greatly improves the flame retardant property of the nanocomposites. This study confirms the strong influence of NiO nanoparticles on the thermal, mechanical, and flame retardant properties of the alkyd/epoxy/NiO nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41490.
A Universal and Facile Way for the Development of Superior Bifunctional Electrocatalysts for Oxygen Reduction and Evolution Reactions Utilizing the Synergistic Effect
Authors: Zhu Yinlong , Su Chao , Xu Xiaomin , Zhou Wei , Ran Ran , Shao Zongping 
Published: September 2014

AbstractIncreasing energy demands have stimulated intense research activities on reversible electrochemical conversion and storage systems with high efficiency, low cost, and environmental benignity. It is highly challenging but desirable to develop efficient bifunctional catalysts for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A universal and facile method for the development of bifunctional electrocatalysts with outstanding electrocatalytic activity for both the ORR and OER in alkaline medium is reported. A mixture of Pt/C catalyst with superior ORR activity and a perovskite oxide based catalyst with outstanding OER activity was employed in appropriate ratios, and prepared by simple ultrasonic mixing. Nanosized platinum particles with a wide range of platinum to oxide mass ratios was realized easily in this way. The as‐formed Pt/C–oxide composites showed better ORR activity than a single Pt/C catalyst and better OER activity than a single oxide to bring about much improved bifunctionality (ΔE is only ≈0.8 V for Pt/C–BSCF; BSCF=Ba0.5Sr0.5Co0.8Fe0.2O3−δ), due to the synergistic effect. The electronic transfer mechanism and the rate‐determining step and spillover mechanism were two possible origins of such a synergistic effect. Additionally, the phenomenon was found to be universal, although the best performance could be reached at different platinum to oxide mass ratios for different oxide catalysts. This work thus provides an innovative strategy for the development of new bifunctional electrocatalysts with wide application potentials in high‐energy and efficient electrochemical energy storage and conversion.
Electrochemical Properties of Tin Oxide Flake/Reduced Graphene Oxide/Carbon Composite Powders as Anode Materials for Lithium‐Ion Batteries
Authors: Lee Su Min , Choi Seung Ho , Kang Yun Chan 
Published: September 2014

AbstractHierarchically structured tin oxide/reduced graphene oxide (RGO)/carbon composite powders are prepared through a one‐pot spray pyrolysis process. SnO nanoflakes of several hundred nanometers in diameter and a few nanometers in thickness are uniformly distributed over the micrometer‐sized spherical powder particles. The initial discharge and charge capacities of the tin oxide/RGO/carbon composite powders at a current density of 1000 mA g−1 are 1543 and 1060 mA h g−1, respectively. The discharge capacity of the tin oxide/RGO/carbon composite powders after 175 cycles is 844 mA h g−1, and the capacity retention measured from the second cycle is 80 %. The transformation during cycling of SnO nanoflakes, uniformly dispersed in the tin oxide/RGO/carbon composite powder, into ultrafine nanocrystals results in hollow nanovoids that act as buffers for the large volume changes that occur during cycling, thereby improving the cycling and rate performances of the tin oxide/RGO/carbon composite powders.
Intramolecular CH/OH Bond Cleavage with Water and Alcohol Using a Phosphine‐Free Ruthenium Carbene NCN Pincer Complex
Authors: Prokopchuk Demyan E. , Tsui Brian T. H. , Lough Alan J. , Morris Robert H. 
Published: September 2014

AbstractTransition metal complexes that exhibit metal–ligand cooperative reactivity could be suitable candidates for applications in water splitting. Ideally, the ligands around the metal should not contain oxidizable donor atoms, such as phosphines. With this goal in mind, we report new phosphine‐free ruthenium NCN pincer complexes with a central N‐heterocyclic carbene donor and methylpyridyl N‐donors. Reaction with base generates a neutral, dearomatized alkoxo–amido complex, which has been structurally and spectroscopically characterized. The tert‐butoxide ligand facilitates regioselective, intramolecular proton transfer through a CH/OH bond cleavage process occurring at room temperature. Kinetic and thermodynamic data have been obtained by VT NMR experiments; DFT calculations support the observed behavior. Isolation and structural characterization of a doubly dearomatized phosphine complex also strongly supports our mechanistic proposal. The alkoxo–amido complex reacts with water to form a dearomatized ruthenium hydroxide complex, a first step towards phosphine‐free metal–ligand cooperative water splitting.
CFD simulation of complete drawdown of floating solids in a stirred tank
Authors: Qiao Shengchao , Wang Rijie , Yang Xiaoxia , Yan Yuefei 
Published: September 2014

AbstractComputational fluid dynamics (CFD) simulations were carried out to find a CFD methodology to predict the critical impeller speed (NCS) for the complete drawdown of floating solids in a stirred tank with an up‐ and down‐pumping pitched blade turbine (PBTU and PBTD). CFD models along with six mixing parameters predicted that NCS was 7.5 rps and 5.8 rps, respectively, for PBTU and PBTD, when impeller submergence (S) was equal to half of the liquid height (H/2). Reasonable agreement was observed between CFD simulations and published empirical correlation. NCS was smaller for PBTD relative to PBTU at S = H/2, which agreed with results in the literature. The drawdown mechanisms based on the mean drag, turbulent fluctuations or large scale eddies failed to explain the difference in NCS between PBTU and PBTD. The flow patterns based on a simulated velocity field were further investigated and successfully accounted for this difference.
Spectrum‐efficiency enhancement in small cell networks with biasing cell association and eICIC: An analytical framework
Authors: Wang Yongbin , Ji Hong , Zhang Heli 
Published: September 2014

SUMMARYLoad balancing and interference management play crucial roles in small cell network (SCN) capacity and spectrum efficiency (SE) enhancement. By performing load balancing between macrocell and small cells, biasing cell association has attracted great attentions since it is proposed. Additionally, enhanced intercell interference coordination (eICIC) technology is also developed as an efficient interference mitigation method for the biasing cell association‐based SCNs. In this paper, we develop an SE enhancement framework with joint consideration of the eICIC factor and biasing factor. Using the stochastic geometry theory, the network is modeled by spatial Poisson point process. We firstly derive the downlink average rate, which is performed at a typical user. Secondly, the eICIC factor‐related network SE is analyzed by proving the existence of optimal eICIC factor, which maximizes the network SE. For the intractability of the closed‐form expression of optimal eICIC factor, a bisection search‐based algorithm is developed then. At last, numerical results confirm our analysis and show the proposed algorithm performance. Copyright © 2014 John Wiley & Sons, Ltd.
A Values‐Based Approach to Vulnerability and Adaptation to Climate Change. Applying Q methodology in the Ebro Delta, Spain
Authors: Albizua Amaia , Zografos Christos 
Published: September 2014

ABSTRACTOutcome and context‐focused approaches to climate change adaptation dominate the relevant literature. Taking into account values and perceptions of affected actors and decision‐makers is a fundamental and necessary prerequisite for a more effective, legitimate and fair climate policy and has not been given the necessary consideration. This paper uses Q methodology to explore such values in the context of climate change in the Ebro Delta, in Catalonia. The delta is an area highly vulnerable to climate change, mainly because of its topography, but also as a result of human intervention. The study identifies five discourses on vulnerability and adaptation held by delta inhabitants and decision‐makers. Social justice and security comprise shared values behind arguments; however, discourses differ in their approaches concerning the proper scale for applying these values with adaptation policy. Our results serve to improve policy dialogue and suggest that the adaptation policy agenda should focus on pursuing consensus over the crucial issue of scale. Our use of Q methodology to advance the incipient literature on value‐based climate change vulnerability and adaptation is innovative and suggests that the approach has a capacity to contribute to advancing deliberative environmental decision‐making on adaptation. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment
Investigations on cell disruption of oleaginous microorganisms: Hydrochloric acid digestion is an effective method for lipid extraction
Authors: Yu Xiaochen , Dong Tao , Zheng Yubin , Miao Chao , Chen Shulin 
Published: September 2014

Cell disruption is an important step used to substantially increase lipid recovery prior to extraction. This is the first study exploring the effects of cell disruption methods on lipid recovery from different oleaginous microorganisms. Specifically, we examined the effects of cell disruption methods, including autoclaving, bead‐beating, microwaving, sonication, acid digestion, and Soxhlet extraction on the yeast Cryptococcus curvatus, the fungus Mortierella isabellina and the microalga Chlorella sorokiniana. Although lipid recovery by cell disruption methods varied with microbial species, autoclaving and microwaving resulted in the lowest lipid contents for all tested strains. The Soxhlet method achieved the highest lipid content of 63.4% for M. isabellina and 12.8% for C. sorokiniana, followed by acid digestion. The highest lipid content of C. curvatus was achieved at 47.3% through acid digestion, compared to sonication, bead‐beating and Soxhlet methods. This study suggests that acid digestion may be the most simple and effective method for lipid recovery from the tested species in terms of time and reaction temperature. Moreover, fatty acid profile analysis revealed that lipids extracted by acid digestion were similar to those from untreated microbial cells, indicating a favorable feedstock for use in biodiesel production.Practical applications: An effective cell disruption method is critical for not only enhancing the lipid recovery in a large scale but also reporting the accurate values of lipid contents of microorganisms in a lab scale. Different cell disruption methods have different effects on lipid extraction from different microorganisms. In this work, for the first time, we performed comparative investigations among yeast, fungus, and microalga to reveal the lipid recovery yields by cell disruption methods for microbial lipid extraction from different oleaginous microorganisms and identified their most effective methods for analytical lipid determination.An effective cell disruption method is critical for enhancing lipid recovery and reporting the accurate lipid contents of microorganisms. In this study, the authors performed comparative investigations among yeast, fungus, and microalga to determine the lipid recovery yields from these oleaginous micro organisms using various cell disruption methods. They identified the most effective cell disruption methods for analytical lipid determination in each microorganism.
Total Synthesis of Micromide: a Marine Natural Product
Authors: Han Jianrong , Lian Jingtang , Tian Xia , Zhou Shengwei , Zhen Xiaoli , Liu Shouxin 
Published: September 2014

AbstractThis paper describes an efficient procedure for the synthesis of micromide, a natural product that shows anti‐solid‐tumor activity. Our strategy involved the synthesis of N‐nosyl‐protected amino acids and their N‐methylation with iodomethane. The hindered oligopeptides containing N‐methyl amino acids were synthesized in excellent yields and high purities.
Poly‐(Alizarin Red S)‐Modified Glassy Carbon Electrode for Simultaneous Electrochemical Determination of Levodopa, Homovanillic Acid and Ascorbic Acid
Authors: Hatefi‐Mehrjardi Abdolhamid , Ghaemi Nasrin , Karimi Mohammad Ali , Ghasemi Masoumeh , Islami‐Ramchahi Somaieh 
Published: September 2014

AbstractA polymeric film of Alizarin Red S was formed on a glassy carbon electrode and used for electrochemical detection of Levodopa (L‐DOPA) and homovanillic acid (HVA) in the presence of ascorbic acid (AA). The sensor represented excellent electrocatalytic activity for their oxidations. The resultant differential pulse voltammograms show well defined and fully resolved anodic oxidation peaks for determination of the analytes. Anodic oxidation currents of L‐DOPA, HVA, and AA showed linearity with good correlation coefficient (>0.996), high sensitivity, and low detection limits (6, 17, and 30 nM respectively). The sensor was used for recovery of analytes in human plasma samples.
Mental Health Service User Experience of Positive Psychotherapy
Authors: Brownell Tamsin , Schrank Beate , Jakaite Zivile , Larkin Charley , Slade Mike 
Published: September 2014

ObjectiveService user satisfaction with therapy is a key part of the therapeutic process. The aim of this study was to investigate service user experiences of an 11‐week group positive psychology intervention for psychosis (WELLFOCUS PPT) in the context of a randomized controlled trial (ISRCTN04199273).MethodParticipants were 37 individuals (51% male; mean age 45.6 years) receiving the intervention as part of the trial. Semistructured interviews and focus groups were conducted to investigate participants’ views of WELLFOCUS PPT. Transcripts were analyzed both deductively and inductively to identify common themes.ResultsFeedback about the group experience was positive throughout. Components found helpful included learning to savor experiences, identifying and developing strengths, forgiveness, gratitude, and therapist self‐disclosure.ConclusionFindings emphasize the importance of considering service users’ perceptions of therapy and can be used to guide clinicians in deciding whether to include one or more of the components of WELLFOCUS PPT in therapy.
Preference pulses induced by reinforcement
Authors: Hachiga Yosuke , Sakagami Takayuki , Silberberg Alan 
Published: September 2014

AbstractEight rats responded on concurrent Variable‐Ratio 20 Extinction schedules for food reinforcement. The assignment of variable‐ratio reinforcement to a left or right lever varied randomly following each reinforcer, and was cued by illumination of a stimulus light above that lever. Postreinforcement preference levels decreased substantially and reliably over time when the lever that just delivered reinforcement was now in extinction; however, if that lever was once again associated with variable ratio, this decrease in same‐lever preference tended to be small, and for some subjects, not in evidence. The changes in preference level to the extinction lever were well described by a modified version of Killeen, Hanson, and Osborne's (1978) induction model. Consistent with this model's attribution of preference change to induction, we attribute preference change in this report to a brief period of reinforcer‐induced arousal that energizes responding to the lever that delivered the last reinforcer. After a few seconds, this induced responding diminishes, and the operant responding that remains comes under the control of the stimulus light cuing the lever providing variable‐ratio reinforcement.
Fiber optical parametric amplifiers in optical communication systems
Authors: Marhic (†) Michel E. , Andrekson Peter A. , Petropoulos Periklis , Radic Stojan , Peucheret Christophe , Jazayerifar Mahmoud 
Published: September 2014

AbstractThe prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase‐insensitive amplifiers (PIAs) and phase‐sensitive amplifiers (PSAs) are considered. Low‐penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength‐ and time‐division multiplexed formats. High‐quality mid‐span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All‐optical amplitude regeneration of amplitude‐modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase‐modulated signals. A PSA with 1.1‐dB noise figure has been demonstrated, and preliminary wavelength‐division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength‐division multiplexed long‐haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long‐haul communication networks are discussed.
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