bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐compartment structure of subsurface‐intensified mesoscale eddies in the ocean
Authors: Zhang Zhengguang , Zhang Yu , Wang Wei 
Published: January 2017

AbstractMesoscale eddies are energetically dominant and pervasive over most of the world's oceans. Among them, many are subsurface intensified with strongest signals in the ocean interior such as mode‐water eddies, which trap water masses with distinctive properties and carry them over long distances. With both Argo profiling floats and atmospheric reanalysis data we showed that the structure of these eddies obeys a universal rule. Hence their three‐dimensional hydrographic fields can be readily reconstructed from very limited information. More interestingly, the volume of water trapped and moved by a mode‐water eddy is much greater than previously thought; it has a three‐compartment structure in the vertical with the mode water being sandwiched between two layers of notably different properties and accounting for only a portion of the total trapped volume.
On the predictive potential of Pc5 ULF waves to forecast relativistic electrons based on their relationships over two solar cycles
Authors: Lam Hing‐Lan 
Published: January 2017

AbstractA statistical study of relativistic electron (>2 MeV) fluence derived from geosynchronous satellites and Pc5 ultralow frequency (ULF) wave power computed from a ground magnetic observatory data located in Canada's auroral zone has been carried out. The ground observations were made near the foot points of field lines passing through the GOESs from 1987 to 2009 (cycles 22 and 23). We determine statistical relationships between the two quantities for different phases of a solar cycle and validate these relationships in two different cycles. There is a positive linear relationship between log fluence and log Pc5 power for all solar phases; however, the power law indices vary for different phases of the cycle. High index values existed during the descending phase. The Pearson's cross correlation between electron fluence and Pc5 power indicates fluence enhancement 2–3 days after strong Pc5 wave activity for all solar phases. The lag between the two quantities is shorter for extremely high fluence (due to high Pc5 power), which tends to occur during the declining phases of both cycles. Most occurrences of extremely low fluence were observed during the extended solar minimum of cycle 23. The precursory attribute of Pc5 power with respect to fluence and the enhancement of fluence due to rising Pc5 power both support the notion of an electron acceleration mechanism by Pc5 ULF waves. This precursor behavior establishes the potential of using Pc5 power to predict relativistic electron fluence.
Comparative Study of Various Pyrazole‐based Anions: A Promising Family of Ionic Derivatives as Insensitive Energetic Materials
Authors: Yin Ping , Mitchell Lauren A. , Parrish Damon A. , Shreeve Jean'ne M. 
Published: January 2017

AbstractIn the design of advanced energetic materials, high‐density explosophores play a pivotal role because of their remarkable enhancement of both density and molecular stability. Using diversified functionalization strategies, a comparative study involving various nitropyrazole anions shows that these are crucially important in determining performance and stability. A promising family of pyrazole‐based energetic ionic derivatives were synthesized and characterized by NMR and IR spectroscopies, and elemental analysis. Among them, 7, 8, 11–13 exhibit favorable overall performance as energetic materials.
Belastungsversuche an einer historischen Eisenbahn‐Gewölbebrücke
Authors: Schacht Gregor , Piehler Jens , Marx Steffen , Müller Jens Z.A. 
Published: January 2017

AbstractDie Eisenbahn‐Gewölbebrücke über die Aller in Verden wurde im Oktober 2015 nach über 150 Jahren außer Betrieb genommen und im Sommer 2016 endgültig abgebrochen. Durch das entstandene Zeitfenster zwischen Außerbetriebnahme und Abbruch ergab sich bei diesem Bauwerk die außergewöhnliche Chance, das Tragverhalten der Gewölbereihe experimentell mithilfe einer Probebelastung zu untersuchen. Ein Projektteam unter Führung des Instituts für Massivbau der Leibniz Universität Hannover führte im März und im Juni 2016 zwei Belastungsversuche durch und konnte das Tragverhalten des Gewölbes weit oberhalb des Gebrauchslastniveaus unter einer0 maximalen Belastung von ca. 570 t () untersuchen. In den zwei Versuchen konnten unter anderem die Einflüsse der Stirnwand und der Abdichtungsschicht auf das Verformungsverhalten erfasst und durch eine Vielzahl lokaler und globaler Verformungsmessungen quantifiziert werden. Aus den Ergebnissen der Untersuchungen sollen Rechenmethoden und ‐annahmen verbessert werden, damit die Tragsicherheit bestehender Gewölbebrücken zukünftig zuverlässiger und realitätsnäher bewertet werden kann.
Disrupted neural activity patterns to novelty and effort in young adult APOE‐e4 carriers performing a subsequent memory task
Authors: Evans Simon , Dowell Nicholas G. , Tabet Naji , King Sarah L. , Hutton Samuel B. , Rusted Jennifer M. 
Published: January 2017

AbstractIntroductionThe APOE e4 allele has been linked to poorer cognitive aging and enhanced dementia risk. Previous imaging studies have used subsequent memory paradigms to probe hippocampal function in e4 carriers across the age range, and evidence suggests a pattern of hippocampal overactivation in young adult e4 carriers.MethodsIn this study, we employed a word‐based subsequent memory task under fMRI; pupillometry data were also acquired as an index of cognitive effort. Participants (26 non‐e4 carriers and 28 e4 carriers) performed an incidental encoding task (presented as word categorization), followed by a surprise old/new recognition task after a 40 minute delay.ResultsIn e4 carriers only, subsequently remembered words were linked to increased hippocampal activity. Across all participants, increased pupil diameter differentiated subsequently remembered from forgotten words, and neural activity covaried with pupil diameter in cuneus and precuneus. These effects were weaker in e4 carriers, and e4 carriers did not show greater pupil diameter to remembered words. In the recognition phase, genotype status also modulated hippocampal activity: here, however, e4 carriers failed to show the conventional pattern of greater hippocampal activity to novel words.ConclusionsOverall, neural activity changes were unstable in e4 carriers, failed to respond to novelty, and did not link strongly to cognitive effort, as indexed by pupil diameter. This provides further evidence of abnormal hippocampal recruitment in young adult e4 carriers, manifesting as both up and downregulation of neural activity, in the absence of behavioral performance differences.
Discovery of a Potent BTK Inhibitor with a Novel Binding Mode by Using Parallel Selections with a DNA‐Encoded Chemical Library
Authors: Cuozzo John W. , Centrella Paolo A. , Gikunju Diana , Habeshian Sevan , Hupp Christopher D. , Keefe Anthony D. , Sigel Eric A. , Soutter Holly H. , Thomson Heather A. , Zhang Ying , Clark Matthew A. 
Published: January 2017

AbstractWe have identified and characterized novel potent inhibitors of Bruton's tyrosine kinase (BTK) from a single DNA‐encoded library of over 110 million compounds by using multiple parallel selection conditions, including variation in target concentration and addition of known binders to provide competition information. Distinct binding profiles were observed by comparing enrichments of library building block combinations under these conditions; one enriched only at high concentrations of BTK and was competitive with ATP, and another enriched at both high and low concentrations of BTK and was not competitive with ATP. A compound representing the latter profile showed low nanomolar potency in biochemical and cellular BTK assays. Results from kinetic mechanism of action studies were consistent with the selection profiles. Analysis of the co‐crystal structure of the most potent compound demonstrated a novel binding mode that revealed a new pocket in BTK. Our results demonstrate that profile‐based selection strategies using DNA‐encoded libraries form the basis of a new methodology to rapidly identify small molecule inhibitors with novel binding modes to clinically relevant targets.
Tailoring Asymmetric Discharge‐Charge Rates and Capacity Limits to Extend Li‐O2 Battery Cycle Life
Authors: Geaney Hugh , O'Dwyer Colm 
Published: January 2017

AbstractWidespread issues with the fundamental operation and stability of Li‐O2 cells impact cycle life and efficiency. While the community continues to research ways of mitigating side reactions and improving stability to realize Li‐O2 battery prospects, we show that limiting the depth‐of‐discharge while unbalancing discharge/charge rate symmetry can extend Li‐O2 battery cycle life by ensuring efficient reversible Li2O2 formation, markedly improving cell efficiency. Systematic variation of the discharge/charge currents shows that clogging from discharging the Li‐O2 cell at high current (250 μA) can be somewhat negated by recharging with a lower applied current (50 μA), with a marked improvement in cycle life achievable. Our measurements determined that specific reduction of the depth of discharge in decrements from equivalent capacities of 1000 mAhg−1 to 50 mAhg−1 under symmetric discharge/charge currents of 50 μA strongly affect the cumulative discharge capacity of each cell. A maximum cumulative discharge capacity occurs at ∼10 % depth of discharge (500 mAhg−1) and the cumulative discharge capacity of 39,500 mAhg−1 is significantly greater than that of cells operated at higher and lower depths of discharge. The results emphasize the importance of appropriate discharge/charge rate and depth of discharge selection for other cathode/electrolyte combinations for directly improving the cycle life performance of Li‐O2 batteries.
Systematic Study of Open‐Shell Trigonal Pyramidal Transition‐Metal Complexes with a Rigid‐Ligand Scaffold
Authors: Pinkowicz Dawid , Birk Francisco J. , Magott Michał , Schulte Kelsey , Dunbar Kim R. 
Published: January 2017

AbstractA family of distorted trigonal pyramidal transition‐metal complexes [MII(N3N)Li(THF)] (M=Mn, Fe, Co, Ni) have been studied as candidates for mononuclear single‐molecule magnets. Magnetic anisotropy of the family depends on the electronic configuration of the central ion, with the Co analogue exhibiting pronounced SMM behavior.
Water‐Soluble Spiropyrans with Inverse Photochromism and Their Photoresponsive Electrostatic Self‐Assembly
Authors: Moldenhauer Daniel , Gröhn Franziska 
Published: January 2017

AbstractA new type of light responsive nanoscale assemblies based on water‐soluble spiropyrans is presented. We have synthesized four anionic spiropyrans bearing multiple sulfonate groups and investigated their photochromic behavior in aqueous solution. Depending on the pH, either inverse photochromism (acidic conditions) or normal photochromism (alkaline conditions) is found. Kinetic data for the interconversion of the spiropyran and merocyanine isomers including the subsequent slow hydrolysis have been obtained by UV/Vis spectroscopy. The results show that the spiropyrans undergo hydrolysis in both alkaline and acidic solution, while in the latter the rate is far slower than in the former. This prolonged hydrolytic stability together with the inverse photochromism under acidic conditions makes the sulfonated spiropyrans suitable to build photoresponsive nanostructures with cationic polyelectrolytes. We show how the self‐assembly process is driven by electrostatic interactions and how the spiropyrans’ photochromic property allows the size control of the supramolecular objects by visible light. The assembly size is characterized by dynamic light scattering and TEM. In addition, UV/Vis and fluorescence spectroscopy and ζ‐potential measurements help to explain the size change upon visible light irradiation.
Conformational Changes and Competitive Adsorption between Serum Albumin and Hemoglobin on Bioceramic Substrates
Authors: Gruian Cristina Mihaela , Rickert Christian , Nicklisch Sascha C. T. , Vanea Emilia , Steinhoff Heinz‐Jürgen , Simon Simion 
Published: January 2017

AbstractTraditional methods to analyze interactions and conformational changes of proteins adsorbed onto biomaterials are limited by the protein's associations with the substrate material and the complexity of the surrounding media. We have used EPR spectroscopy in combination with site‐directed spin labeling (SDSL) to investigate single protein and competitive adsorption kinetics of horse hemoglobin (Hgb) and bovine serum albumin (BSA) on a silica–calcium–phosphate bioceramic substrate. Combined continuous wave and pulsed (DEER) EPR techniques were employed to monitor local mobility/flexibility changes within the proteins and tertiary structure dynamics upon adsorption. An alternate labeling technique was introduced to allow for specific quantification of each protein adsorbed to the bioceramic surface. We show that at buffer pH 7.4 and 4.7 the amount of adsorbed hemoglobin was increased by a factor of 4–5 compared with BSA. The tertiary structure of hemoglobin was strongly affected upon adsorption, leading to a dissociation of the tetrameric molecule into monomers or αβ dimers. When the bioceramic substrate was previously functionalized with a layer of BSA, dissociation was reduced by 71 % compared with the untreated surface, indicating a “primer” effect of BSA for better adhesion of the globular hemoglobin.
DNA with Different Local Torsional States Affects RecA‐Mediated Recombination Progression
Authors: Lu Chih‐Hao , Li Hung‐Wen 
Published: January 2017

AbstractDNA topology is thought to affect DNA enzyme activity. The helical structure of duplex DNA dictates the change of topological states during strand separation when DNA is constrained. During the repair of DNA double‐stranded breaks, the RecA nucleoprotein filament invades DNA and carries out consecutive strand exchange reactions coupled with duplex DNA strand separation. It has been suggested that torsional strain could be generated and its accumulation could inhibit strand exchange. We used hairpin and nicked DNA substrates to test how torsional strain alters the RecA‐mediated strand exchange efficiency. Single‐molecule tethered particle motion (TPM) experiments showed that torsionally constrained hairpin DNA substrates returned nearly no successful strand exchange events catalyzed by RecA. Surprisingly, the strand exchange efficiencies increase in the presence of DNA nicks or loop disruption. The dwell time of transient RecA events in hairpin is shorter compared to those found in nicked or fork DNA substrates, which suggests a limited strand exchange progression in hairpin substrates. Our observation shows that RecA generates local torsional strain during strand exchange, and the inability to dissipate this torsional strain inhibits homologous recombination progression. DNA topological states are thus important regulation measures of DNA recombination.
Investigating Solvent Effects of an Ionic Liquid on Pericyclic Reactions through Kinetic Analyses of Simple Rearrangements
Authors: Keaveney Sinead T. , Haines Ronald S. , Harper Jason B. 
Published: January 2017

AbstractSimple Cope and Claisen rearrangements were investigated in an ionic liquid and a range of molecular solvents through a series of kinetic studies. Analysis of the solvent effects on the Cope rearrangement of 3‐phenyl‐1,5‐hexadiene indicated that a solvophobic effect was responsible for the observed rate enhancement in the ionic liquid, and that this was due to preferential solvation of the transition state. A similar solvophobic effect contributes to the ionic liquid solvent effect on the Claisen rearrangement of allyl vinyl ether, although the ability of the ionic liquid to stabilise the incipient charges in the transition state also likely contributes to the rate increase observed in the ionic liquid solvent. The activation parameter data suggest that in this case the ionic liquid was interacting with species along the reaction coordinate through general coulombic interactions (more acetonitrile‐like) rather than through hydrogen‐bonding interactions (less ethanol‐like).
Strong Asymmetry in the Perepoxide Bifurcation Mechanism: The Large‐Group Effect in the Singlet Oxygen Ene Reaction with Allylic Alcohols
Authors: Griesbeck Axel G. , Goldfuss Bernd , Jäger Christina , Brüllingen Eric , Lippold Tim , Kleczka Margarethe 
Published: January 2017

AbstractThe singlet oxygen reactions of sterically crowded allylic alcohols result in the preferential formation of γ‐hydroperoxy alcohols with regioselectivities up to 98:2. The kinetic cis effect still prevails in the first, rate‐determining step of this two‐step non‐intermediate ene mechanism (kE‐5/kZ‐5=1.9). The primary allylic alcohol 3 showed no regioselectivity at all, increasing the steric demands at the α carbon and directing the singlet oxygen addition towards the γ carbon up to 98:2 regioselectivity. DFT calculations rationalized these results and show the decisive role of the symmetry‐breaking bifurcation following the early transition states. The use of the products as substrates for the synthesis of five‐ and seven‐membered ring peroxides, namely 4‐methylene‐1,2‐dioxolanes and 6‐methylene‐1,2,4‐trioxepanes, by rare earth metal complexes as Lewis acids is also demonstrated.
A Novel Nebulizer‐Based Continuous Flow Reactor: Introducing the Use of Pneumatically Generated Aerosols for Highly Productive Photooxidations
Authors: Ioannou Georgios I. , Montagnon Tamsyn , Kalaitzakis Dimitris , Pergantis Spiros A. , Vassilikogiannakis Georgios 
Published: January 2017

AbstractA very effective and highly innovative continuous flow reactor (CFR) for undertaking important large‐scale photooxidations is presented. Until now, two major issues have obstructed the widespread use of photooxidation CFRs: 1) the detrimental effect of poor oxygen solubility on the rate of biphasic gas–liquid reactions and 2) the rapid attenuation of light by solutions which severely limits dimension‐enlarging opportunities. Both problems are nullified by this novel and yet extremely simple reactor design. The reactor operates by nebulizing a photooxidation solution inside a cylindrical chamber surrounded by a low‐energy LED strip. Thus, the interfacial area between the two phases is maximized, leading to greatly improved reaction rates and excellent light penetration. This pneumatic nebulizer‐based photooxygenation system (NebPhotOX) can use air (as the oxygen source) and very concentrated photooxidation solutions. NebPhotOX has very high productivity and could potentially be scaled up easily to work in an industrial setting.
Efficient Cleavage of Lignin–Carbohydrate Complexes and Ultrafast Extraction of Lignin Oligomers from Wood Biomass by Microwave‐Assisted Treatment with Deep Eutectic Solvent
Authors: Liu Yongzhuang , Chen Wenshuai , Xia Qinqin , Guo Bingtuo , Wang Qingwen , Liu Shouxin , Liu Yixing , Li Jian , Yu Haipeng 
Published: January 2017

AbstractLignocellulosic biomass is an abundant and renewable resource for the production of biobased value‐added fuels, chemicals, and materials, but its effective exploitation by an energy‐efficient and environmentally friendly strategy remains a challenge. Herein, a facile approach for efficiently cleaving lignin–carbohydrate complexes and ultrafast fractionation of components from wood by microwave‐assisted treatment with deep eutectic solvent is reported. The solvent was composed of sustainable choline chloride and oxalic acid dihydrate, and showed a hydrogen‐bond acidity of 1.31. Efficient fractionation of lignocellulose with the solvent was realized by heating at 80 °C under 800 W microwave irradiation for 3 min. The extracted lignin showed a low molecular weight of 913, a low polydispersity of 1.25, and consisted of lignin oligomers with high purity (ca. 96 %), and thus shows potential in downstream production of aromatic chemicals. The other dissolved matter mainly comprised glucose, xylose, and hydroxymethylfurfural. The undissolved material was cellulose with crystal I structure and a crystallinity of approximately 75 %, which can be used for fabricating nanocellulose. Therefore, this work promotes an ultrafast lignin‐first biorefinery approach while simultaneously keeping the undissolved cellulose available for further utilization. This work is expected to contribute to improving the economics of overall biorefining of lignocellulosic biomass.
Doping control analysis of lithium in horse urine and plasma by inductively coupled plasma mass spectrometry
Authors: Choi Timmy L. S. , Wong Jenny K. Y. , Ho Emmie N. M. , Kwok Wai Him , Leung Gary N. W. , Curl Peter , Wan Terence S. M. 
Published: January 2017

Lithium salts are commonly prescribed to treat bipolar disorder in humans. They are effective for the treatment of acute mania and the prophylaxis of manic relapses through long‐term use. Although there is no reported legitimate therapeutic use of lithium in horses, its potential mood‐stabilizing effect, low cost, and ready availability make lithium salt a potential agent of abuse in equine sports, especially for equestrian competition horses. Lithium can be found in soil, plants, and water, as such it is naturally present in the equine body, thus a threshold is necessary to control its misuse in horses. This paper describes the validation of quantification methods for lithium in equine urine and plasma using inductively coupled plasma mass spectrometry (ICP‐MS). Based on a population study of lithium in horse urine and an administration study using a single oral dose of lithium chloride (100 mg) to mimic the daily lithium intake from a diet rich in lithium, a urinary threshold of 5 μg/mL was proposed. Applying this urinary threshold to two other administration studies (a single oral dose of 65 g of lithium chloride, and a single intravenous dose of 2.54 g of lithium chloride), excessive lithium in urine could be detected for 8 days and 2.5 days respectively. The concentrations of lithium in plasma following these three lithium chloride administration trials were also studied. Copyright © 2017 John Wiley & Sons, Ltd.