bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Access to Fluoromethylated Arenes by Nickel‐Catalyzed Cross‐Coupling between Arylboronic Acids and Fluoromethyl Bromide
Authors: An Lun , Xiao Yu‐Lan , Min Qiao‐Qiao , Zhang Xingang 
Published: June 2015

AbstractThe nickel‐catalyzed fluoromethylation of arylboronic acids was achieved with the industrial raw material fluoromethyl bromide (CH2FBr) as the coupling partner. The reaction proceeded under mild reaction conditions with high efficiency; it features the use of a low‐cost nickel catalyst, synthetic simplicity, and excellent functional‐group compatibility, and provides facile access to fluoromethylated biologically relevant molecules. Preliminary mechanistic studies showed that a single‐electron‐transfer (SET) pathway is involved in the catalytic cycle.
Metal‐Free Dehydrogenative Diels–Alder Reactions of 2‐Methyl‐3‐Alkylindoles with Dienophiles: Rapid Access to Tetrahydrocarbazoles, Carbazoles, and Heteroacenes
Authors: Zhou Liejin , Xu Bing , Zhang Junliang 
Published: June 2015

AbstractAn unprecedented strategy for in situ generation of indole‐based ortho‐quinodimethanes (oQDMs) from 2‐methyl‐3‐alkylmethylindoles by either a metal‐free DDQ‐ or BQ‐mediated dehydrogenative process was developed. These oQDMs were trapped by electron‐deficient dienophiles to provide a facile approach to synthetically valuable tetrahydrocarbazoles, carbazoles, and hetereoacenes. The salient features of this transformation include direct C(sp3)H bond functionalizations, readily available starting materials, metal‐free conditions, high efficiency, operational simplicity, and ease of scale‐up.
Precise Molecular Fission and Fusion: Quantitative Self‐Assembly and Chemistry of a Metallo‐Cuboctahedron
Authors: Xie Ting‐Zheng , Guo Kai , Guo Zaihong , Gao Wen‐Yang , Wojtas Lukasz , Ning Guo‐Hong , Huang Mingjun , Lu Xiaocun , Li Jing‐Yi , Liao Sheng‐Yun , Chen Yu‐Sheng , Moorefield Charles N. , Saunders Mary Jane , Cheng Stephen Z. D. , Wesdemiotis Chrys , Newkome George R. 
Published: June 2015

AbstractInspiration for molecular design and construction can be derived from mathematically based structures. In the quest for new materials, the adaptation of new building blocks can lead to unexpected results. Towards these ends, the quantitative single‐step self‐assembly of a shape‐persistent, Archimedean‐based building block, which generates the largest molecular sphere (a cuboctahedron) that has been unequivocally characterized by synchrotron X‐ray analysis, is described. The unique properties of this new construct give rise to a dilution‐based transformation into two identical spheres (octahedra) each possessing one half of the molecular weight of the parent structure; concentration of this octahedron reconstitutes the original cuboctahedron. These chemical phenomena are reminiscent of biological fission and fusion processes. The large 6 nm cage structure was further analyzed by 1D and 2D NMR spectroscopy, mass spectrometry, and collision cross‐section analysis. New routes to molecular encapsulation can be envisioned.
Rhodium‐Catalyzed ortho‐Selective CF Bond Borylation of Polyfluoroarenes with BpinBpin
Authors: Guo Wen‐Hao , Min Qiao‐Qiao , Gu Ji‐Wei , Zhang Xingang 
Published: June 2015

AbstractAn ortho‐selective CF bond borylation between N‐heterocycle‐substituted polyfluoroarenes and Bpin‐Bpin with simple and commercially available [Rh(cod)2]BF4 as a catalyst is now reported. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, even toward monofluoroarene, thus providing a facile access to a wide range of borylated fluoroarenes that are useful for photoelectronic materials. Preliminary mechanistic studies reveal that a RhIII/V catalytic cycle via a key intermediate rhodium(III) hydride complex [(H)RhIIILn(Bpin)] may be involved in the reaction.
Acetone‐Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling
Authors: Assem Naila , Ferreira David J. , Wolan Dennis W. , Dawson Philip E. 
Published: June 2015

AbstractMacrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone‐linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co‐crystallization of a constrained S‐peptide in complex with RNAse S. The scope of the acetone‐linked peptides was further explored through the generation of N‐terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags.
Structural Elucidation of the Bispecificity of A Domains as a Basis for Activating Non‐natural Amino Acids
Authors: Kaljunen Heidi , Schiefelbein Stephan H. H. , Stummer Daniela , Kozak Sandra , Meijers Rob , Christiansen Guntram , Rentmeister Andrea 
Published: June 2015

AbstractMany biologically active peptide secondary metabolites of bacteria are produced by modular enzyme complexes, the non‐ribosomal peptide synthetases. Substrate selection occurs through an adenylation (A) domain, which activates the cognate amino acid with high fidelity. The recently discovered A domain of an Anabaenopeptin synthetase from Planktothrix agardhii (ApnA A1) is capable of activating two chemically distinct amino acids (Arg and Tyr). Crystal structures of the A domain reveal how both substrates fit into to binding pocket of the enzyme. Analysis of the binding pocket led to the identification of three residues that are critical for substrate recognition. Systematic mutagenesis of these residues created A domains that were monospecific, or changed the substrate specificity to tryptophan. The non‐natural amino acid 4‐azidophenylalanine is also efficiently activated by a mutant A domain, thus enabling the production of diversified non‐ribosomal peptides for bioorthogonal labeling.
A novel hydrogen peroxide sensor based on Ag nanoparticles decorated polyaniline/graphene composites
Authors: Li Shan , Xiong Jianxin , Shen Jingsong , Qin Yong , Li Juan , Chu Fuqiang , Kong Yong , Deng Linhong 
Published: June 2015

ABSTRACTA novel electrochemical sensor based on Ag nanoparticles (AgNPs) decorated polyaniline/graphene composites (PANI/G) is developed, which can be used for sensitive determination of H2O2. For the construction of the H2O2 sensor, polyaniline (PANI) is first electrodeposited on the surface of graphene (G) to form PANI/G, and then horseradish peroxidase (HRP) loaded on AgNPs (HRP/AgNPs) is immobilized on to the PANI/G. H2O2 can be catalyzed by HRP to generate current response which can be significantly enhanced by AgNPs, and thus the PANI/G based sensor can be utilized for the detection of H2O2. Under the optimized conditions, the proposed H2O2 sensor exhibits wide linear response to H2O2 concentration ranging from 0.25 to 2.25 mM with a detection limit of 0.03 mM (signal‐to‐noise ratio of 3), and it also shows high selectivity and reproducibility. The method is simple and cost‐effective, and can be a promising candidate as the sensitive sensing platform for H2O2. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42409.
Antibacterial poly(lactic acid) (PLA) films grafted with electrospun PLA/allyl isothiocyanate fibers for food packaging
Authors: Kara Hasan H. , Xiao Fugang , Sarker Majher , Jin Tony Z. , Sousa Ana M. M. , Liu Cheng‐Kung , Tomasula Peggy M. , Liu LinShu 
Published: June 2015

ABSTRACTPoly(lactic acid) (PLA) fibers of submicron sizes encapsulating allyl isothiocyanate (AITC) (PfA) were made and electrospun onto the surfaces of PLA films. SEM examination confirmed the fusion of the two phases to form a bilayered fiber‐grafted film after the film underwent air blowing and water washing to remove the nongrafted fibers. The fiber‐grafted PLA films (PfA‐g‐film) retain the mechanical properties of PLA. The release of AITC from the fibers was temperature dependent. At temperatures lower than 4°C, the incorporated AITC remained within the fibers without losing activity; at room temperature, AITC released in a sustained manner over weeks. The release of AITC was also dependent on its initial concentration in the PLA electrospinning solution; samples with more AITC incorporated showed a higher release rate. PfA‐g‐films significantly inhibited the growth of Listeria innocua and Escherichia coli k12 when tested on package foods. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42475.
Solubility factors as screening tools of biodegradable toughening agents of polylactide
Authors: Ruellan Alexandre , Guinault Alain , Sollogoub Cyrille , Ducruet Violette , Domenek Sandra 
Published: June 2015

ABSTRACTChanges in the thermomechanical properties of polylactide (PLA) plasticized by two biodegradable and biobased molecules, Polysorb ID37 (PID37) and squalene, were compared to formulations with petroleum‐based plasticizers, namely, acetyl tributyl citrate, poly(ethylene glycol) 400, and dioctyl adipate (DOA). The solubility parameters of the additives were calculated and were related to the plasticization behaviors. PID37 proved to be miscible with PLA because of its polar functions and short alkyl groups. It decreased the PLA glass‐transition temperature (Tg) and increased in ductility when Tg approached room temperature. Squalene had a low miscibility because of the absence of polar groups. Tg was not depressed. Ductility improvements were nevertheless reached because the immiscible inclusions efficiently induced crazing by the distribution of stress concentration points all over the material; this delayed failure. The maximum elongations at break were 60% for squalene, 400% for DOA, and 500% for PID37. The solubility factors were, thus, an efficient prediction tool for the plasticizing behavior. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42476.
Production of bacterial nanobiocomposites of polyhydroxyalkanoates derived from waste and bacterial nanocellulose by the electrospinning enabling melt compounding method
Authors: Martínez‐Sanz Marta , Lopez‐Rubio Amparo , Villano Marianna , Oliveira Catarina S. S. , Majone Mauro , Reis Maria , Lagarón Jose M. 
Published: June 2015

ABSTRACTThis work reports on the characterization of nanocomposites fully synthesized by bacteria, consisting of polyhydroxybutyrate‐co‐hydroxyvalerate (PHBV) matrices reinforced with bacterial cellulose nanowhiskers (BCNW). Two PHBV grades, with 9% HV (PHBV9) and 16% HV (PHBV16), were synthesized using food industry waste feedstocks and compared with a 3% HV commercial grade (PHBV3). Whereas PHBV3 presented a high barrier performance but excessive brittleness, PHBV9 and PHBV16 showed a more ductile behavior and reduced barrier properties. Subsequently, BCNW were incorporated into the PHBVs by a high‐throughput electrospinning technique to produce master‐batch formulations with relatively high nanofiller concentrations. The hybrid ultrathin fibers showed homogeneous morphologies and greater thermal stability than the pure PHBV fibers. Nanocomposites were then produced by melt mixing PHBVs with the hybrid fibers. Despite the low compatibility between the extremely hydrophilic BCNW and the hydrophobic PHBVs, the nanofiller was highly dispersed and provided a reduction in oxygen permeability of the PHBV3 matrix without relevant modifications in mechanical performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42486.
Heritability of the Human Craniofacial Complex
Authors: Šešelj Maja , Duren Dana L. , Sherwood Richard J. 
Published: June 2015

ABSTRACTQuantifying normal variation and the genetic underpinnings of anatomical structures is one of the main goals of modern morphological studies. However, the extent of genetic contributions to normal variation in craniofacial morphology in humans is still unclear. The current study addresses this gap by investigating the genetic underpinnings of normal craniofacial morphology. The sample under investigation consists of 75 linear and angular measurements spanning the entire craniofacial complex, recorded from lateral cephalographs of 1,379 participants in the Fels Longitudinal Study. Heritabilities for each trait were estimated using SOLAR, a maximum‐likelihood variance components approach utilizing all pedigree information for parameter estimation. Trait means and mean effects of the covariates age, sex, age2, sex × age, and sex × age2 were simultaneously estimated in the analytic models. All traits of the craniofacial complex were significantly heritable. Heritability estimates ranged from 0.10 to 0.60, with the majority being moderate. It is important to note that we found similar ranges of heritability occurring across the different functional/developmental components of the craniofacial complex, the splanchnocranium, the basicranium, and the neurocranium. This suggests that traits from different regions of the craniofacial complex are of comparable utility for the purposes of population history and phylogeny reconstruction. At the same time, this genetic influence on craniofacial morphology signals a caution to researchers of nongenetic studies to consider the implications of this finding when selecting samples for study given their project design and goals. Anat Rec, 298:1535–1547, 2015. © 2015 Wiley Periodicals, Inc.
A Solution‐Processable Molecule using Thieno[3,2‐b]thiophene as Building Block for Efficient Organic Solar Cells
Authors: Wei Huan , Chen Weichao , Han Liangliang , Wang Ting , Bao Xichang , Li Xiaoyun , Liu Jie , Zhou Yuanhang , Yang Renqiang 
Published: June 2015

AbstractA solution‐processed acceptor‐π‐donor‐π‐acceptor (A‐π‐D‐π‐A) type small molecule, namely DCATT, has been designed and synthesized for the application as donor material in organic solar cells. The fused aromatic unit thieno[3,2‐b]thiophene (TT) flanked with thiophene is applied as π bridge, while 4,8‐bisthienyl substituted benzodithiophene (BDT) and 2‐ethylhexyl cyanoacetate are chosen as the central building block and end group, respectively. Introduction of fused ring to the small molecule enhances the conjugation length of the main chain, and gives a strong tendency to form π–π stacking with a large overlapping area which favors to high charge carrier transport. Small‐molecule organic solar cells based on blends of DCATT and fullerene acceptor exhibit power conversion efficiencies as high as 5.20 % under the illumination of AM 1.5G, 100 mW cm−2.
Finely Resolved Threshold for the Sharp M12L24/M24L48 Structural Switch in Multi‐Component MnL2n Polyhedral Assemblies: X‐ray, MS, NMR, and Ultracentrifugation Analyses
Authors: Yokoyama Hiroyuki , Ueda Yoshihiro , Fujita Daishi , Sato Sota , Fujita Makoto 
Published: June 2015

AbstractIn the self‐assembly of MnL2n polyhedra, the bend angle (θ) of the divalent ligand components determines the final structure. The threshold for the sharp structural switch between M12L24 and M24L48 was finely resolved to within just 4° by demonstrating the exclusive formation of M12L24 cuboctahedra or M24L48 rhombicuboctahedra from two similar ligands with θ values of 130° and 134°. This sharp structural switch was fully confirmed by X‐ray crystallography, mass spectrometry, NMR spectroscopy, and ultracentrifugation analyses.
Nano PdAu Bimetallic Alloy as an Effective Catalyst for the Buchwald–Hartwig Reaction
Authors: Chen Zheng , Wang Shuo , Lian Chao , Liu Yuxi , Wang Dingsheng , Chen Chen , Peng Qing , Li Yadong 
Published: June 2015

AbstractIt is highly challenging but desirable to develop efficient heterogeneous catalysts for C−Cl bond activation in coupling reactions. Here, we succeeded in synthesizing bimetallic Pd‐Au nanoparticles through a convenient one‐pot wet chemical route. The composition and alloyed structure of the as‐prepared nanoparticles were fully characterized. We have evaluated the catalytic activity of these Pd‐Au alloy catalysts in Buchwald–Hartwig reactions of aryl chlorides. The excellent catalytic activity of the as‐obtained Pd‐Au nanoparticles indicates that exploiting the catalytic power of nano‐alloy catalysts could enable effective C−Cl bond activation suitable for cross‐coupling reactions.
Novel Highly Energetic Pyrazoles: N‐Trinitromethyl‐Substituted Nitropyrazoles
Authors: Dalinger Igor L. , Vatsadze Irina A. , Shkineva Tatyana K. , Kormanov Alexandr V. , Struchkova Marina I. , Suponitsky Kyrill Yu. , Bragin Anatoly A. , Monogarov Konstantin A. , Sinditskii Valery P. , Sheremetev Aleksei B. 
Published: June 2015

AbstractA new family of energetic compounds, nitropyrazoles bearing a trinitromethyl moiety at the nitrogen atom of the heterocycle, was designed. The desirable high‐energy dense oxidizers 3,4‐dinitro‐ and 3,5‐dinitro‐1‐(trinitromethyl)pyrazoles were synthesized in good yields by destructive nitration of the corresponding 1‐acetonylpyrazoles. All of the prepared compounds were fully characterized by multinuclear NMR and IR spectroscopy, as well as by elemental analysis. Single‐crystal X‐ray diffraction studies show remarkably high density. Impact sensitivity tests and thermal stability measurements were also performed. All of the pyrazoles possess positive calculated heats of formation and exhibit promising energetic performance that is the range of 1,3,5‐trinitroperhydro‐1,3,5‐triazine and pentaerythritol tetranitrate. The new pyrazoles exhibit positive oxygen balance and are promising candidates for new environmentally benign energetic materials.
Relationship between cold winters over Northern Asia and the subsequent hot summers over mid‐lower reaches of the Yangtze River valley under global warming
Authors: Qiao Shaobo , Gong Zhiqiang , Feng Guolin , Qian Zhonghua 
Published: June 2015

AbstractUnder global warming, cold winters over Northern Asia are highly correlated with the subsequent hot summers over middle and lower reaches of the Yangtze River valley (MLYRV). This high correlation may result from an oceanic bridge's effect in the Western Pacific. The mechanism may be described as follows: the atmospheric circulation anomalies of cold winters corresponds with a simultaneous warmer Western Pacific warm pool (WPWP) by decreasing surface latent heat fluxes. The warmer sea surface temperature (SST) can persist and move eastward gradually to the subsequent summer through the oceanic processes, and thus in turn affect the hot days (HDs) over MLYRV.
Optimization of coordinated signal settings for hook‐turn intersections
Authors: Bie Yiming , Liu Zhiyuan , Lu Linjun 
Published: June 2015

SummaryHook turn (HT) is a unique traffic regulation rule for right‐turning vehicles at intersections (in the system where driving is on the left), which was proposed in Melbourne to improve the safety level and operational efficiency of intersections. However, existing coordination plans for HT intersections are fixed and determined empirically, which restricts the further improvements of the efficiency. In this paper, mathematical models are developed for the calculation of the average vehicle delay, with consideration of the spillback phenomenon of HT vehicles in waiting areas. The platoon dispersion model is used to describe the traffic movements between coordinated intersections. With the aim of minimizing average delay of all vehicles, a mixed nonlinear integer model is developed for the optimal coordination plan, which is solved by a genetic algorithm due to the complexity of the model. Finally, a numerical example is built based on three HT intersections in downtown Melbourne, to verify the proposed methodology. Based on a comparison with the current signal plan, the optimal signal plan can significantly reduce the average delay as well as the number of spillbacks, in both the peak hour and off‐peak hour cases. Copyright © 2015 John Wiley & Sons, Ltd.
Decision Pattern Analysis as a General Framework for Studying Individual Differences in Decision Making
Authors: Jackson Simon A. , Kleitman Sabina , Stankov Lazar , Howie Pauline 
Published: June 2015

ABSTRACTThis paper investigated decision pattern analysis (DPA) as a general and standard framework for studying individuals' consistent decision making behavior within and between contexts. DPA classifies decisions on the basis of judgement accuracy and the goal orientation of the decided‐upon action. Over repeated decisions, patterns of individuals' decision behavior are described by five variables: competence, optimality, recklessness, hesitancy and decisiveness. A fictitious medical decision making test and three standard cognitive ability tests (extended with confidence ratings and a ‘submit answer for marking’ decision) were used to investigate the psychometric properties of these DPA variables. Internal consistency of the decision patterns ranged from good to excellent. Convergent validity was assessed via cognitive abilities, metacognitive confidence and a control criterion imposed on confidence that determines the decision to be made: the point of sufficient certainty. Personality variables were included to assess discriminant validity. As hypothesised, cognitive abilities showed positive correlations with competence and optimality. High confidence, low points of sufficient certainty and a greater discrepancy between them were associated with higher decisiveness and recklessness, and lower hesitancy. Personality measures showed mixed and generally weak correlations with the DPA variables. These convergent and discriminant results also held after controlling for all variables in regression. The results provide preliminary psychometric support for DPA as a general framework of behavioral decision making. DPA has the potential to be exploited in many contexts for uses that, to date, have been unachievable in a psychometrically valid manner. Copyright © 2015 John Wiley & Sons, Ltd.
Fermentation broth components influence droplet coalescence and hinder advanced biofuel recovery during fermentation
Authors: Heeres Arjan S. , Schroën Karin , Heijnen Joseph J. , van der Wielen Luuk A. M. , Cuellar Maria C. 
Published: June 2015

AbstractDevelopments in synthetic biology enabled the microbial production of long chain hydrocarbons, which can be used as advanced biofuels in aviation or transportation. Currently, these fuels are not economically competitive due to their production costs. The current process offers room for improvement: by utilizing lignocellulosic feedstock, increasing microbial yields, and using cheaper process technology. Gravity separation is an example of the latter, for which droplet growth by coalescence is crucial. The aim of this study was to study the effect of fermentation broth components on droplet coalescence. Droplet coalescence was measured using two setups: a microfluidic chip and regular laboratory scale stirred vessel (2 L). Some fermentation broth components had a large impact on droplet coalescence. Especially components present in hydrolysed cellulosic biomass and mannoproteins from the yeast cell wall retard coalescence. To achieve a technically feasible gravity separation that can be integrated with the fermentation, the negative effects of these components on coalescence should be minimized. This could be achieved by redesign of the fermentation medium or adjusting the fermentation conditions, aiming to minimize the release of surface active components by the microorganisms. This way, another step can be made towards economically feasible advanced biofuel production.