bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient Allylation of Nucleophiles Catalyzed by a Bifunctional Heterogeneous Palladium Complex‐Tertiary Amine System
Authors: Noda Hiroto , Motokura Ken , Miyaji Akimitsu , Baba Toshihide 
Published: March 2013

AbstractWe demonstrate the synergistic catalysis of a silica‐supported diaminopalladium complex and a tertiary amine (SiO2/diamine/Pd/NEt2) as well as synthetic scope of the Tsuji–Trost reaction of 1,3‐dicarbonyls, phenols, and carboxylic acids with allyl carbonate and acetates. The synergistic catalysis of SiO2/diamine/Pd/NEt2 exhibited wide applicability and high activity for the Tsuji–Trost reaction. For example, the reaction of ethyl 3‐oxobutanate with allyl methyl carbonate afforded the allylated product in >99% yield at 70 °C for 5 h. The yield of allylated products was 26% for SiO2/diamine/Pd, without immobilization of the tertiary amine group. In the reaction of 1.0 mmol of ethyl 3‐oxobutanate using 0.60 μmol of Pd in SiO2/diamine/Pd/NEt2, the turnover number (TON) of Pd reached up to 1070 within 24 h. Phenols with electron‐withdrawing groups, such as nitro and chloro groups, on the para position resulted in high product yields. The SiO2/diamine/Pd/NEt2 catalyst was reusable at least 4 times without appreciable loss of its activity and selectivity in the reaction of p‐chlorophenol.
Pd2dba3/Bippyphos: A Robust Catalyst System for the Hydroxylation of Aryl Halides with Broad Substrate Scope
Authors: Lavery Christopher B. , Rotta‐Loria Nicolas L. , McDonald Robert , Stradiotto Mark 
Published: March 2013

AbstractA mixture of tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3) and 5‐(di‐tert‐butylphosphino)‐1′,3′,5′‐triphenyl‐1′H‐[1,4′]bipyrazole (Bippyphos) is shown to be a robust and efficient catalyst system for the hydroxylation of structurally diverse (hetero)aryl halides under mild conditions and with broad substrate scope. Included in this reactivity survey is the successful synthesis of substituted benzofurans and related heteroatomic derivatives, which are formed via the hydroxylation of 2‐haloalkynylarenes. Notably, a significant number of the reactions reported herein proceed at room temperature, and we have demonstrated that it is possible to conduct reactions on the benchtop under air using unpurified solvents with negligible loss in reactivity versus related transformations conducted under inert atmosphere conditions. We also report herein the first crystallographically characterized (Bippyphos)Pd(II) complex, which confirms the ability of this synthetically useful ligand to adopt a bidentate binding motif in a manner similar to Buchwald’s biarylphosphine ligand class.
Observation of a Quadrupole Surface Plasmon Mode for Au Nanorods: Effects of Surface Roughness and Crystal Facets
Authors: Hong Soonchang , Shuford Kevin L. , Park Sungho 
Published: March 2013

AbstractThis paper describes how the surface roughness and synthetic methods of Au nanorods affect the optical properties that are often associated with localized surface plasmon resonances. We synthesized Au nanorods with different aspect ratios and surface roughness by using two different synthetic strategies to observe surface plasmon resonance bands. One set of nanorods was prepared in high yield by using a seed‐mediated dropwise‐addition method with a growth‐directing surfactant in aqueous solution (Au nanorods in aqueous phase, GNRA). The other set of Au nanorods were synthesized by the electrochemical deposition of Au onto an anodized aluminum oxide (AAO) template (Au nanorods by AAO template, GNRT). The length of the nanorods was controlled by changing the total charge that was passed through the cell and their diameter was monitored by changing the diameter of the template channel. The as‐prepared Au nanorods were optimized to observe a quadrupole mode, which is one of the higher‐order surface plasmon bands. Our results showed differences between the optical properties of GNRA and GNRT. The roughness and crystal structure of the Au nanorods affected their optical properties. Smooth and single‐crystal surface on GNRA had larger and sharper peaks than GNRT. The discrete dipole approximation (DDA) method was used to calculate the optical properties of the Au nanorods and these results were in good agreement with our experimental results.
Could Carbonaceous Impurities in Reduced Graphenes be Responsible for Some of Their Extraordinary Electrocatalytic Activities?
Authors: Wang Lu , Ambrosi Adriano , Pumera Martin 
Published: March 2013

AbstractThermally and chemically reduced graphene materials contain significant amounts of carbonaceous impurities that are similar in structure to amorphous carbon. Herein, we show that the claimed electrocatalytic activities of these materials for the oxidation of NADH, acetaminophen, and hydroquinone are mainly due to the presence of carbonaceous impurities.
Assessing the effect of stricter sustainability criteria on EU biomass crop potential
Authors: Elbersen Berien , Fritsche Uwe , Petersen Jan‐Erik , Lesschen Jan Peter , Böttcher Hannes , Overmars Koen 
Published: March 2013

AbstractThis paper investigates how different sustainability criteria restrict the supply of cropped biomass sources within the EU. There are already mandatory sustainability criteria formulated in the Renewable Energy Directive (RED) at EU level for biomass feedstocks to be used for conversion into biofuels. For solid and gaseous biomass feedstock, however, there are only recommendations formulated by the European Commission (EC) to be adopted on a voluntary basis by the EU member states (MS). This paper specifically focuses on the potential supply of biomass from crops for all bioenergy sectors when applying stricter sustainability criteria. These criteria relate to greenhouse gas (GHG) mitigation targets, including indirect land‐use change (iLUC) related GHG emissions, and the introduction of no‐go areas, such as areas of high biodiversity value and high carbon stock. The results show that stricter criteria indeed reduce the cropping potential and change the crop mix significantly, as rotational arable crops for biofuels do no longer comply with the stricter mitigation criteria. This is because they usually compete with food and feed crops for higher quality land requiring a compensation for iLUC emissions. The stricter sustainability criteria can only be applied successfully if they are accompanied by a change in demand, in particular for lignocellulosic biomass for advanced biofuels and other bioenergy uses. Without stimulation of such pathways, it will be difficult to realize improved sustainability in the bio‐energy sector. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd
Single‐Molecule Detection Reveals Knot Sliding in TrmD Denaturation
Authors: Wang Peng , Yang Lijiang , Liu Pengcheng , Gao Yi Qin , Zhao Xin Sheng 
Published: March 2013

AbstractAn increasing number of proteins are found to contain a knot in their polypeptide chain. Although some studies have looked into the folding mechanism of knotted proteins, why and how these complex topologies form are still far from being fully answered. Moreover, no experimental information about how the knot moves during the protein‐folding process is available. Herein, by combining single‐molecule fluorescence resonance energy transfer (smFRET) experiments with molecular dynamics (MD) simulations, we performed a detailed study to characterize the knot in the denatured state of TrmD, a knotted tRNA (guanosine‐1) methyltransferase from Escherichia coli, as a model system. We found that the knot still existed in the unfolded state of TrmD, consistent with the results for two other knotted proteins, YibK and YbeA. More interestingly, both smFRET experiments and MD simulations revealed that the knot slid towards the C‐terminal during the unfolding process, which could be explained by the relatively strong interactions between the β‐sheet core at the N terminal of the native knot region. The size of the knot in the unfolded state is not larger than that in the native state. In addition, the knot slid in a “downhill” mode with simultaneous chain collapse in the denatured state.
Sequential chemoimmunotherapy of fludarabine, mitoxantrone, and cyclophosphamide induction followed by alemtuzumab consolidation is effective in T‐cell prolymphocytic leukemia
Authors: Hopfinger Georg , Busch Raymonde , Pflug Natali , Weit Nicole , Westermann Anne , Fink Anna‐Maria , Cramer Paula , Reinart Nina , Winkler Dirk , Fingerle‐Rowson Günter , Stilgenbauer Stephan , Döhner Hartmut , Kandler Gabriele , Eichhorst Barbara , Hallek Michael , Herling Marco 
Published: March 2013

BACKGROUNDScarce systematic trial data have prevented uniform therapeutic guidelines for T‐cell prolymphocytic leukemia (T‐PLL). A central need in this historically refractory tumor is the controlled evaluation of multiagent chemotherapy and its combination with the currently most active single agent, alemtuzumab.METHODSThis prospective multicenter phase 2 trial assessed response, survival, and toxicity of a novel regimen in previously treated (n = 9) and treatment‐naive (n = 16) patients with T‐PLL. Induction by fludarabine, mitoxantrone, and cyclophosphamide (FMC), for up to 4 cycles, was followed by alemtuzumab (A) consolidation, up to 12 weeks.RESULTSOf the 25 patients treated with FMC, 21 subsequently received alemtuzumab. Overall response rate to FMC was 68%, comprising 6 complete remissions (all bone‐marrow confirmed) and 11 partial remissions. Alemtuzumab consolidation increased the intent‐to‐treat overall response rate to 92% (12 complete remissions; 11 partial remissions). Median overall survival after FMC‐A was 17.1 months and median progression‐free survival was 11.9 months. Progression‐free survival tended to be shorter for patients with high‐level T‐cell leukemia 1 oncoprotein expression. Hematologic toxicities were the most frequent grade 3/4 side effects under FMC‐A. Exclusively in the 21 alemtuzumab‐consolidated patients, 13 cytomegalovirus reactivations were observed; 9 of these 13 represented a clinically relevant infection.CONCLUSIONSFMC‐A is a safe and efficient protocol in T‐PLL, which compares favorably to published data. Cancer 2013;119:2258–2267. © 2013 American Cancer Society.
An Interplay of Cooperativity between Cation⋅⋅⋅π, Anion⋅⋅⋅π and CH⋅⋅⋅Anion Interactions
Authors: Mandal Tarun K. , Samanta Siddhartha , Chakraborty Sourav , Datta Ayan 
Published: March 2013

AbstractMixed cation (Li+, Na+and K+) and anion (F−, Cl−, Br−) complexes of the aromatic π‐surfaces (top and bottom) are studied by using dispersion‐corrected density functional theory. The selectivity of the aromatic surface to interact with a cation or an anion can be tuned and even reversed by the electron‐donating/electron‐accepting nature of the side groups. The presence of a methyl group in the OCH3, SCH3, OC2H5in the side groups of the aromatic ring leads to further cooperative stabilization of the otherwise unstable/weakly stable anion⋅⋅⋅π complexes by bending of the side groups towards the anion to facilitate CH⋅⋅⋅anion interactions. The cooperativity among the interactions is found to be as large as 100 kcal mol−1quantified by dissection of the three individual forces from the total interaction energy. The crystal structures of the fluoride binding tripodal and hexapodal ligands provide experimental evidence for such cooperative interactions.
Controllable Assembly and Dehydrogenation Catalysis Activity of Urchinlike FeNi–Ru(tips) Amorphous Alloy Hierarchical Nanostructures
Authors: Sun Yuzhen , Wen Ming , Wu Qingsheng , Wu Qingnan 
Published: March 2013

AbstractNovel, urchinlike FeNi–Ru(tips) hierarchical‐structured nanospheres (≈9.17 µm) were constructed through a controllable assembly process. Offering large surface areas and macropores as well as more active sites, this special structured catalyst can greatly facilitate reactant diffusion and transport to promote reactivity. By combining the advantages of Ru and FeNi nanomaterials, the resultant urchinlike FeNi–Ru(tips) nanospheres exhibit excellent catalytic activity with the dehydrogenation rate of 2245.87 mL min−1 g−1 toward the hydrolytic dehydrogenation of aqueous NaBH4 under ambient atmosphere at room temperature, in which Fe19Ni76–Ru5 shows the best dehydrogenation reactivity with low activation energy (41.57 kJ mol−1). Additionally, these new structured nanoalloys present controllable ferromagnetic behavior by means of adjusting the molar content of Fe, Ni, and Ru.
Network mobility protocol for vehicular ad hoc networks
Authors: Chen Yuh‐Shyan , Hsu Chih‐Shun , Cheng Ching‐Hsueh 
Published: March 2013

SUMMARYThe goal of the network mobility management is to effectively reduce the complexity of handoff procedure and keep mobile devices connecting to the Internet. When users are going to leave an old subnet and enter a new subnet, the handoff procedure is executed on the mobile device, and it may break off the real‐time service, such as VoIP or mobile TV, because of the mobility of mobile devices. Because a vehicle is moving so fast, it may cause the handoff and packet loss problems. Both of the problems will lower down the throughput of the network. To overcome these problems, we propose a novel network mobility protocol for vehicular ad hoc networks. In a highway, because every car is moving in a fixed direction at a high speed, a car adopting our protocol can acquire an IP address from the vehicular ad hoc network through the vehicle‐to‐vehicle communications. The vehicle can rely on the assistance of a front vehicle to execute the prehandoff procedure, or it may acquire a new IP address through multihop relays from the car on the lanes of the same or opposite direction and thus may reduce the handoff delay and maintain the connectivity to the Internet. Simulation results have shown that the proposed scheme is able to reduce both the handoff delay and packet loss rate. Copyright © 2013 John Wiley & Sons, Ltd.
Environmental associations with gene transcription inBabineLake rainbow trout: evidence for local adaptation
Authors: Wellband Kyle W. , Heath Daniel D. 
Published: March 2013

AbstractThe molecular genetic mechanisms facilitating local adaptation in salmonids continue to be poorly characterized. Gene transcription is a highly regulated step in the expression of a phenotype and it has been shown to respond to selection and thus may be one mechanism that facilitates the development of local adaptation. Advances in molecular genetic tools and an increased understanding of the functional roles of specific genes allow us to test hypotheses concerning the role of variable environments in shaping transcription at known‐function candidate loci. To address these hypotheses, wild rainbow trout were collected in their first summer and subjected to metabolic and immune challenges. We assayed gene transcription at candidate loci that play a role in the molecular genetic response to these stresses, and correlated transcription with temperature data from the streams and the abundance and diversity of bacteria as characterized by massively parallel pyrosequencing. Patterns of transcriptional regulation from resting to induced levels varied among populations for both treatments. Co‐inertia analysis demonstrated significant associations between resting levels of metabolic gene transcription and thermal regime (R2 = 0.19,P = 0.013) as well as in response to challenge (R2 = 0.39,P = 0.001) and resting state and challenged levels of cytokine gene transcription with relative abundances of bacteria (resting:R2 = 0.25,P = 0.009, challenged:R2 = 0.65,P = 0.001). These results show that variable environments, even within a small geographic range (<250 km), can drive divergent selection among populations for transcription of genes related to surviving stress.
Nickel Nanoparticles as Racemization Catalysts for Primary Amines
Authors: Geukens Inge , Plessers Eva , Seo Jin Won , De Vos Dirk E. 
Published: March 2013

AbstractBy combining bases that are known to racemize benzylic amines with a nickel(II) salt, active nickel nanoparticles were obtained that can be used as catalysts in the racemization of both aliphatic and benzylic primary amines. The nanoparticles are stable in the ionic liquid tetrabutylammonium bromide and can complete most racemizations within a few hours with excellent selectivity. The problem of the incompatibility of the strongly reducing racemization catalyst and the enzymatic amine resolution catalyst was overcome by using a two‐pot system with a biphasic racemization step. Consecutive contact of a nonane layer that contained the amine with the acylating enzyme and with the racemizing Ni nanoparticles in the ionic liquid allowed the 50 % amide yield limit of a kinetic resolution to be successfully surpassed.
Aromatic Claisen Rearrangements of O‐Prenylated Tyrosine and Model Prenyl Aryl Ethers: Computational Study of the Role of Water on Acceleration of Claisen Rearrangements
Authors: Osuna Sílvia , Kim Seonah , Bollot Guillaume , Houk Kendall N. 
Published: March 2013

AbstractLynF, an enzyme from the TruF family, O‐prenylates tyrosines in proteins; subsequent Claisen rearrangements give C‐prenylated tyrosine products. These reactions in tyrosines and model phenolic systems have been explored with DFT and SCS‐MP2 calculations. Various ab initio benchmarks have been used (CBS‐QB3, MP2, SCS‐MP2) to examine the accuracy of commonly used density functionals, such as B3LYP and M06‐2X. Solvent effects from water were considered by using implicit and explicit models. Studies of the ortho‐C‐prenylation and Claisen rearrangement of tyrosine, and the Claisen rearrangement of α,α‐dimethylallyl (prenyl) coumaryl ether establish the energetics of these reactions both in the gas phase and in aqueous solution.
Detection of the antibacterial effect of essential oils on outer membrane proteins of Pseudomonas aeruginosa by lab‐on‐a‐chip and MALDI‐TOF/MS
Authors: Felső Péter , Horváth Györgyi , Bencsik Tímea , Godányi Roland , Lemberkovics Éva , Böszörményi Andrea , Böddi Katalin , Takátsy Anikó , Molnár Péter , Kocsis Béla 
Published: March 2013

ABSTRACTIn bacteria, structural changes of outer membrane protein (OMP) composition may have an effect on the adhesive ability and pathogenic properties of the organisms. Pseudomonas aeruginosa can develop an intrinsic resistance to a wide range of biocides, which is associated with the nature of its outer membrane. The aim of our study was to examine how the essential oils of cinnamon bark and clove modify the OMP composition of the human pathogen P. aeruginosa strains and to identify the structure of proteins that are considerably changed after incubation with essential oils. Chemical composition of the oils was analysed by using gas chromatography and gas chromatography–mass spectrometry. Eugenol (83.7%) was the main component of the clove oil, while trans‐cinnamic aldehyde (73.2%) was the main constituent in cinnamon bark oil. Values for the minimum inhibitory concentration (MIC) of the oils were determined by a modified tube dilution method. The oils were administered to the culture at concentrations of 0.5 × MIC and 2 × MIC and incubated for 60 min. After OMP preparation, the structure of proteins was analysed by MALDI‐TOF/MS. Cinnamon and clove oil could influence the OMP composition of Pseudomonas strains. Proteins with molecular weights of 42.7 kDa and 79.4 kDa disappeared after treatment with cinnamon and clove oil, respectively. Quantitative changes in the protein profile may contribute to the explanation of the antibacterial effect of cinnamon bark and clove essential oils on pathogenic Pseudomonas strains. Copyright © 2013 John Wiley & Sons, Ltd.
Comparison of non‐reflective boundary conditions for a free‐rising turbulent axisymmetric plume
Authors: Hattori T. , Norris S.E. , Kirkpatrick M.P. , Armfield S.W. 
Published: March 2013

SUMMARYThe stability and accuracy of radiation type non‐reflective outflow boundary conditions, as well as the standard Neumann boundary condition with zero normal derivative, have been compared for the numerical simulation of a turbulent axisymmetric plume with Reynolds number of 7700 and Prandtl number of 0.71. Comparison of the performance of the boundary conditions with respect to each other, and to the results obtained for an extended domain, shows that a one‐dimensional scheme in which advection and diffusion terms are included in the radiation equation is the optimum approach for the plume simulation. Copyright © 2013 John Wiley & Sons, Ltd.
Exercise to Lose Money? Irrational Exercise Behavior from the Chinese Warrants Market
Authors: Liao Li , Li Zhisheng , Zhang Weiqiang , Zhu Ning 
Published: March 2013

AbstractUsing a market‐level exercise data set and an individual‐level trading data set between August 2006 and June 2009, this study examines the incidence of two types of irrational exercise behavior in the Chinese warrants market. We find that 121.64 million shares of warrants (0.64% of all warrants) were either exercised with an immediate loss or failed to be exercised, resulting in foregone risk‐free profits. These irrational exercises caused warrant holders to lose over 717.79 million Yuan. Some of the irrational behavior can be attributed to “entertainment seeking” and the “T + 1” rule practiced in the Chinese security market, but the majority is attributed to warrant holders' ignorance and/or negligence of warrant mechanics. Our findings provide additional field evidence of clearly irrational exercise behavior in a derivatives market. We also find that investor education, information and guidance provision can mitigate the incidence of irrational exercise behavior significantly. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 34:399–419, 2014
Legislation—Dodd‐Frank: You Might Be a Swap Dealer if…
Authors: Prokop Michael 
Published: March 2013

AbstractWhile the title of this article may sound a bit like the beginning of a Jeff Foxworthy comedy routine, it is very much the way many firms that are trading in the energy markets feel today. Continued regulatory uncertainty, delays in regulatory rule implementations, and the changing face of the market have most market participants cautiously moving forward with the daily trading requirements as they exist now.
Heteroatom Effects on Electronic Excited State Hydrogen Bonding of Fluorenone‐Based Molecular Materials
Authors: Cheng Yufei , Zhang Xiaoyu , Zhang Weiping 
Published: March 2013

ABSTRACTIn this work, the geometry optimizations in the ground state and electronic excitation energies and corresponding oscillation strengths of the low‐lying electronically excited states for the isolated fluorenone (FN) and FN‐based molecular monomers, the relatively hydrogen‐bonded dimers, and doubly hydrogen‐bonded trimers, are calculated by the density functional theory and time‐dependent density functional theory methods, respectively. We find the intermolecular hydrogen bond CO···HO is strengthened in some of the electronically excited states of the hydrogen‐bonded dimers and doubly hydrogen‐bonded trimers, because the excitation energy in a related excited state decrease and electronic spectral redshift are induced. Similarly, the hydrogen bond CO···HO is weakened in other excited states. On this basis, owing to the important difference of electronegativity, heteroatoms S, Se, and Te that substitute for the O atom in the carbonyl group of the FN molecule have a significant effect on the strength of the hydrogen bond and the spectral shift. It is observed that the hydrogen bond CTe···HO is too weak to be formed. When the CS and CSe substitute for CO, the strength of the hydrogen bonds and electronic spectra frequency shift are significantly changed in the electronic excited state due to the electron transition type transformation from the ππ* feature to σπ* feature. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:153–162, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21075