bluuebunny/crossref_metadata_2025_split huggingface dataset:
The age of iron and iron source attribution in the ocean
Authors: Holzer Mark , Frants Marina , Pasquier Benoît 
Published: September 2016

AbstractWe use tracers to partition dissolved iron (dFe) into the contributions from each source within a numerical model of the iron cycle without perturbing the system. These contributions are further partitioned according to the time since injection into the ocean, which defines their iron‐age spectrum and mean iron age. The utility of these diagnostics is illustrated for a family of inverse model estimates of the iron cycle, constrained by a data‐assimilated circulation and available dFe measurements. The source contributions are compared with source anomalies defined as the differences between solutions with and without the source in question. We find that in the Southern Ocean euphotic zone, the hydrothermal and sediment contributions range from 15% to 30% of the total each, which the anomalies underestimate by a factor of ∼2 because of the nonlinearity of scavenging. The iron age is only reset by scavenging and attains a mean of several hundred years in the Southern Ocean euphotic zone, revealing that aeolian iron there is supplied primarily from depth as regenerated dFe. Tagging iron according to source region and pathways shows that 70–80% of the aeolian dFe in the euphotic zone near Antarctica is supplied from north of 46°S via paths that reach below 1 km depth. Hydrothermal iron has the oldest surface mean ages on the order of middepth ventilation times. A measure of uncertainty is provided by the systematic variations of our diagnostics across the family of iron cycle estimates, each member of which has a different aeolian source strength.
High atmospheric horizontal resolution eliminates the wind‐driven coastal warm bias in the southeastern tropical Atlantic
Authors: Milinski Sebastian , Bader Jürgen , Haak Helmuth , Siongco Angela Cheska , Jungclaus Johann H. 
Published: September 2016

AbstractWe investigate the strong warm bias in sea surface temperatures (SST) of the southeastern tropical Atlantic that occurs in most of the current global climate models. We analyze this bias in the Max Planck Institute Earth System Model at different horizontal resolutions ranging from 0.1° to 0.4° in the ocean and 0.5° to 1.8° in the atmosphere. High atmospheric horizontal resolution eliminates the SST bias close to the African coast, due to an improved representation of surface wind stress near the coast. This improvement affects coastal upwelling and horizontal ocean circulation, as confirmed with dedicated sensitivity experiments. The wind stress improvements are partly caused by the better represented orography at higher horizontal resolution in the spectral atmospheric model. The reductions of the coastal SST bias obtained through higher horizontal resolution do not, however, translate to a reduction of the large‐scale bias extending westward from the African coast into the southeastern tropical Atlantic.
Frictional evolution, acoustic emissions activity, and off‐fault damage in simulated faults sheared at seismic slip rates
Authors: Passelègue François. X. , Spagnuolo Elena , Violay Marie , Nielsen Stefan , Di Toro Giulio , Schubnel Alexandre 
Published: September 2016

AbstractWe present a series of high‐velocity friction tests conducted on Westerly granite, using the Slow to HIgh Velocity Apparatus (SHIVA) installed at Istituto Nazionale di Geofisica e Vulcanologia Roma with acoustic emissions (AEs) monitored at high frequency (4 MHz). Both atmospheric humidity and pore fluid (water) pressure conditions were tested, under effective normal stress
in the range 5–20 MPa and at target sliding velocities Vs in the range 0.003–3 m/s. Under atmospheric humidity two consecutive friction drops were observed. The first one is related to flash weakening, and the second one to the formation and growth of a continuous layer of melt in the slip zone. In the presence of fluid, a single drop in friction was observed. Average values of fracture energy are independent of effective normal stress and sliding velocity. However, measurements of elastic wave velocities on the sheared samples suggested that larger damage was induced for 0.1 < Vs<0.3 m/s. This observation is supported by AEs recorded during the test, most of which were detected after the initiation of the second friction drop, once the fault surface temperature was high. Some AEs were detected up to a few seconds after the end of the experiments, indicating thermal rather than mechanical cracking. In addition, the presence of pore water delayed the onset of AEs by cooling effects and by reducing of the heat produced, supporting the link between AEs and the production and diffusion of heat during sliding. Using a thermoelastic crack model developed by Fredrich and Wong (1986), we confirm that damage may be induced by heat diffusion. Indeed, our theoretical results predict accurately the amount of shortening and shortening rate, supporting the idea that gouge production and gouge comminution are in fact largely controlled by thermal cracking. Finally, we discuss the contribution of thermal cracking in the seismic energy balance. In fact, while a dichotomy exists in the literature regarding the partitioning between fracture and heat energy, the experimental evidence reported here suggests that both contribute to fault weakening and off‐fault damage.
3‐D multiobservable probabilistic inversion for the compositional and thermal structure of the lithosphere and upper mantle: III. Thermochemical tomography in the Western‐Central U.S.
Authors: Afonso Juan Carlos , Rawlinson Nicholas , Yang Yingjie , Schutt Derek L. , Jones Alan G. , Fullea Javier , Griffin William L. 
Published: September 2016

AbstractWe apply a novel 3‐D multiobservable probabilistic tomography method that we have recently developed and benchmarked, to directly image the thermochemical structure of the Colorado Plateau and surrounding areas by jointly inverting P wave and S wave teleseismic arrival times, Rayleigh wave dispersion data, Bouguer anomalies, satellite‐derived gravity gradients, geoid height, absolute (local and dynamic) elevation, and surface heat flow data. The temperature and compositional structures recovered by our inversion reveal a high level of correlation between recent basaltic magmatism and zones of high temperature and low Mg# (i.e., refertilized mantle) in the lithosphere, consistent with independent geochemical data. However, the lithospheric mantle is overall characterized by a highly heterogeneous thermochemical structure, with only some features correlating well with either Proterozoic and/or Cenozoic crustal structures. This suggests that most of the present‐day deep lithospheric architecture reflects the superposition of numerous geodynamic events of different scale and nature to those that created major crustal structures. This is consistent with the complex lithosphere‐asthenosphere system that we image, which exhibits a variety of multiscale feedback mechanisms (e.g., small‐scale convection, magmatic intrusion, delamination, etc.) driving surface processes. Our results also suggest that most of the present‐day elevation in the Colorado Plateau and surrounding regions is the result of thermochemical buoyancy sources within the lithosphere, with dynamic effects (from sublithospheric mantle flow) contributing only locally up to ∼15–35%.
Wind relaxation and a coastal buoyant plume north of Pt. Conception, CA: Observations, simulations, and scalings
Authors: Suanda Sutara H. , Kumar Nirnimesh , Miller Arthur J. , Di Lorenzo Emanuele , Haas Kevin , Cai Donghua , Edwards Christopher A. , Washburn Libe , Fewings Melanie R. , Torres Rachel , Feddersen Falk 
Published: September 2016

AbstractIn upwelling regions, wind relaxations lead to poleward propagating warm water plumes that are important to coastal ecosystems. The coastal ocean response to wind relaxation around Pt. Conception, CA is simulated with a Regional Ocean Model (ROMS) forced by realistic surface and lateral boundary conditions including tidal processes. The model reproduces well the statistics of observed subtidal water column temperature and velocity at both outer and inner‐shelf mooring locations throughout the study. A poleward‐propagating plume of Southern California Bight water that increases shelf water temperatures by
5°C is also reproduced. Modeled plume propagation speed, spatial scales, and flow structure are consistent with a theoretical scaling for coastal buoyant plumes with both surface‐trapped and slope‐controlled dynamics. Plume momentum balances are distinct between the offshore (>30 m depth) region where the plume is surface‐trapped, and onshore of the 30 m isobath (within 5 km from shore) where the plume water mass extends to the bottom and is slope controlled. In the onshore region, bottom stress is important in the alongshore momentum equation and generates vertical vorticity that is an order of magnitude larger than the vorticity in the plume core. Numerical experiments without tidal forcing show that modeled surface temperatures are biased 0.5°C high, potentially affecting plume propagation distance and persistence.
Thermally Activated Delayed Fluorescence Material as Host with Novel Spiro‐Based Skeleton for High Power Efficiency and Low Roll‐Off Blue and White Phosphorescent Devices
Authors: Wang Ya‐Kun , Sun Qi , Wu Sheng‐Fan , Yuan Yi , Li Qian , Jiang Zuo‐Quan , Fung Man‐Keung , Liao Liang‐Sheng 
Published: September 2016

AbstractEfficiency roll‐off in blue organic light‐emitting diodes especially at high brightness still remains a vital issue for which the excitons density‐dependent mechanism of host materials takes most responsibility. Additionally, the efficiency roll‐off leads to high power consumption and reduces the operating lifetime because higher driving voltage and current are required. Here, by subtly modifying the triphenylamine to oxygen‐bridged quasi‐planar structure, a novel thermally activated delayed fluorescence type blue host Tri‐o‐2PO is successfully developed. Efficiency roll‐off based on Tri‐o‐2PO is ultralow with external quantum efficiency (EQE) just dropping by around 2% in the high luminance range from 1000 cd m−2 to 10 000 cd m−2. As expected, low turn‐on voltage (≈2.9 V) of device is also achieved, which is close to the theory limit value (≈2.62 V). Super‐high power efficiency (≈60 lm W−1) and EQE (>22%) are also achieved when utilizing Tri‐o‐2PO as host. Furthermore, two‐color warm‐white light with CIE of (0.45, 0.43) and correlated color temperature of 2921 K is also fabricated and a champion EQE of 21% is delivered. These excellent performances prove the strategy of bridging the triphenylamine to reduce ΔEst is validated and suggest the great potential of this novel skeleton.
Synthesis of Chiral Dihydrobenzofurans and Phthalides by Asymmetric Transfer Hydrogenation via Dynamic Kinetic Resolution: A Strategy for Total Synthesis of Daldinins A, B, and C and Concentricolide
Authors: Fang Lizhen , Lyu Qinghua , Lu Chenjuan , Li Huanhuan , Liu Saisai , Han Lili 
Published: September 2016

AbstractA versatile and efficient strategy for the total synthesis of the anti‐HIV‐1 agent concentricolide and its analogues daldinins A, B, and C has been established. This strategy offers a mild and facile access to these benzo annulated compounds, bearing multiple stereocenters in good yield with 99% enantiomeric excess (ee) and 93% diastereomeric excess (de) values. Construction of the corresponding syn dihydrobenzofuran and phthalide groups can be achieved in one step by Noyori's asymmetric transfer hydrogenation, via dynamic kinetic resolution.magnified image
Influence of Date Syrup as a Carbon Source on Bacterial Cellulose Production by Acetobacter xylinum 0416
Authors: Lotfiman Samaneh , Awang Biak Dayang Radiah , Ti Tey Beng , Kamarudin Suryani , Nikbin Saeid 
Published: September 2016

AbstractTo improve bacterial cellulose (BC) applications, researchers have expanded their efforts with BC productivity and its properties. The objectives of this study are to evaluate the possibility and efficacy of using extracted date syrup as a carbon source for Acetobacter xylinum 0416 in BC production in a static culture. The sugar content of extracted date syrup was identified by HPLC. Different concentrations of dates and different culturing times were tested. The produced BCs were characterized and their respective properties were compared with a BC produced from Hestrin and Schramm (HS) medium. The most effective BC amount was attained with 3% (w/v) date in the medium on day 8. The modified HS medium (DHS) increased production by 68% (P < 0.05). Morphological analysis by scanning electron microscopy revealed more disorganized arrangements in BC fiber obtained from DHS medium (BC‐DHS) than that from HS medium (BC‐HS). Thermogravimetric analysis revealed no significant changes in BC‐DHS thermostability compared to BC‐HS. However, the crystallinity of BC‐DHS improved (P < 0.05). The results of Fourier transform infrared spectroscopy demonstrated that the carbonyl group in BC‐DHS is more active than that of BC‐HS. Furthermore, the properties of BC‐DHS showed excellent potential for use in many applications.
A Quantitative Fluorescence‐Based Assay for Assessing LIM Domain–Peptide Interactions
Authors: Robertson Neil O. , Shah Manan , Matthews Jacqueline M. 
Published: September 2016

AbstractWe have developed Förster resonance energy transfer (FRET)‐based experiments for measuring the binding affinity, off‐rates, and inferred on‐rates for interactions between a family of transcriptional regulators and their intrinsically disordered binding partners. It was difficult to evaluate these interactions previously, as the transcriptional regulators are obligate binding proteins that aggregate in the absence of a binding partner. The assays rely on fusion constructs where binding domains are linked by a flexible tether containing a specific protease site, with fluorescent proteins at either end that display FRET when the complex is formed. Loss of FRET is monitored after cutting the tether followed by dilution or competition with a non‐fluorescent peptide. These methods allowed a wide range of binding affinities (10−9–10−5 m) to be determined. Our data indicate that interactions of closely related proteins can have surprisingly different binding properties.
Polarity‐Reversed Allylations of Aldehydes, Ketones, and Imines Enabled by Hantzsch Ester in Photoredox Catalysis
Authors: Qi Li , Chen Yiyun 
Published: September 2016

AbstractThe polarity reversal (umpolung) reaction is an invaluable tool for reversing the chemical reactivity of carbonyl and iminyl groups, which subsequent cross‐coupling reactions to form C−C bonds offers a unique perspective in synthetic planning and implementation. Reported herein is the first visible‐light‐induced polarity‐reversed allylation and intermolecular Michael addition reaction of aldehydes, ketones, and imines. This chemoselective reaction has broad substrate scope and the engagement of alkyl imines is reported for the first time. The mechanistic investigations indicate the formation of ketyl (or α‐aminoalkyl) radicals from single‐electron reduction, where the Hantzsch ester is crucial as the electron/proton donor and the activator.
Gene expression of glycyrrhizin acid and accumulation of endogenous signaling molecule in Glycyrrhiza uralensis Fisch adventitious roots after Saccharomyces cerevisiae and Meyerozyma guilliermondii applications
Authors: Li Jianli , Liu Shujie , Wang Juan , Li Jing , Li Jinxin , Gao Wenyuan 
Published: September 2016

AbstractThis study reports the best culture conditions for roots growth and accumulation of active components by optimizing the parameters. Glycyrrhiza uralensis adventitious roots metabolites were significantly increased after adding Saccharomyces cerevisiae and Meyerozyma guilliermondii. The highest contents of polysaccharide, glycyrrhizic acid, glycyrrhetinic acid, and total flavonoids were obtained in M. guilliermondii group; the content of glycyrrhizic acid was 5.3‐fold higher than the control. In control and treatment groups, 12 compounds were identified by high‐performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC–ESI–MS/MS), among which some new compounds have been detected in elicitor groups including 5,7‐dihydroxyflavanone, glycyrrhisoflavanone, licorice saponin J2, uralsaponin B, (3R)‐vestitol, and uralenol. Meyerozyma guilliermondii significantly upregulated the expression of the genes such as 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase, farnesyl diphosphate synthase, geranyl diphosphate synthase, squalene synthase, squalene epoxidase, β‐amyrin synthase, and CYP88D6 and CYP72A154. Meanwhile, it increased the biosynthesis of signaling molecules (nitric oxide, salicylic acid, and jasmonic acid) in defense mechanism.
Stimuli‐responsive delivery of therapeutics for diabetes treatment
Authors: Yu Jicheng , Zhang Yuqi , Bomba Hunter , Gu Zhen 
Published: September 2016

AbstractDiabetic therapeutics, including insulin and glucagon‐like peptide 1 (GLP‐1), are essential for diabetic patients to regulate blood glucose levels. However, conventional treatments that are based on subcutaneous injections are often associated with poor glucose control and a lack of patient compliance. In this review, we focus on the different stimuli‐responsive systems to deliver therapeutics for diabetes treatment to improve patient comfort and prevent complications. Specifically, the pH‐responsive systems for oral drug delivery are introduced first. Then, the closed‐loop glucose‐responsive systems are summarized based on different glucose‐responsive moieties, including glucose oxidase, glucose binding protein, and phenylboronic acid. Finally, the on‐demand delivery systems activated by external remote triggers are also discussed. We conclude by discussing advantages and limitations of current strategies, as well as future opportunities and challenges in this area.
Light‐Activated Triazabutadienes for the Modification of a Viral Surface
Authors: Jensen Stephanie M. , Kimani Flora W. , Jewett John C. 
Published: September 2016

AbstractChemical crosslinking is a versatile tool for the examination of biochemical interactions, in particular host–pathogen interactions. We report the critical first step toward the goal of probing these interactions by the synthesis and use of a new heterobifunctional crosslinker containing a triazabutadiene scaffold. The triazabutadiene is stable to protein conjugation and liberates a reactive aryl diazonium species upon irradiation with 350 nm light. We highlight the use of this technology by modifying the surface of several proteins, including the dengue virus envelope protein.
Catalytic Aerial Oxidation of Biomass‐Derived Furans to Furan Carboxylic Acids in Water over Bimetallic Nickel–Palladium Alloy Nanoparticles
Authors: Gupta Kavita , Rai Rohit K. , Dwivedi Ambikesh D. , Singh Sanjay K. 
Published: September 2016

AbstractBimetallic Ni1−xPdx (0.10≤x≤0.75) alloy nanoparticle catalysts were synthesised and successfully employed for the catalytic aerial oxidation of biomass‐derived furans, such as 2‐furfuraldehyde (furfural), 2‐furfuryl alcohol (furfuryl alcohol), 5‐hydroxymethyl‐2‐furfural (5‐HMF), 5‐methyl‐2‐furfural (MF) and 5‐methyl‐2‐furfuryl alcohol (MFA), to selectively afford the corresponding furan carboxylic acids (2‐furoic acid, furan‐2,5‐dicarboxylic acid (FDCA) and 5‐methyl‐2‐furoic acid (MFCA)) in water at 80 °C. Among the studied Ni1−xPdx nanoparticle catalysts, Ni0.90Pd0.10 nanoparticle catalyst outperformed the others, achieving high yields of the corresponding furan carboxylic acid products. The presence of Ni in the Ni1−xPdx nanoparticle catalysts was advantageous, because it not only enhanced the catalytic activity for the facile oxidation of biomass‐derived furans using aerial oxygen to achieve high catalytic turnover, but also provided excellent stability to the Ni0.90Pd0.10 nanoparticle catalyst towards air and water and thus significantly enhanced its recyclability (up to 10 catalytic runs). The experiments revealed that the catalytic oxidation of 5‐HMF proceeded by the initial oxidation of the formyl group to carboxylic acid, and, subsequently, the conversion of alcohol to carboxylic acid via the formyl group to form FDCA. Moreover, the one‐pot direct transformation of fructose to furan carboxylic acid products (such as FDCA) was also achieved by using the Ni0.90Pd0.10 nanoparticle catalyst.
Coupling the Charging Current and the Electron‐Transfer Process: The Effect on Impedance Spectra
Authors: Du Guoqing , Mantia Fabio La 
Published: September 2016

AbstractBy using a 1D simulation of the charge‐transfer process, taking into account the nature of the electron‐tunnelling and the effect of the electric field in the double layer, we analysed the coupling between double layer charging and faradaic reaction and assessed how this influences the shape of impedance spectra simulated under equilibrium conditions for a redox couple. We carried out the simulations with different concentrations of redox couple and supporting electrolyte at different equilibrium potential. We observed that, independent of the conditions of the simulation, all the data sets could be fitted by a simple Randles circuit. Our results show that the coupling process of faradaic and charging currents is manifested as a deviation of the behaviour of the charge transfer and interface differential capacitance from the expected values; in particular, we show that the electric field affects very strongly the charge transfer resistance, and also that the charge accumulated on the double layer is affected by the electron‐transfer.
Calorimetric Studies and Structural Aspects of Ionic Liquids in Designing Sorption Materials for Thermal Energy Storage
Authors: Brünig Thorge , Krekić Kristijan , Bruhn Clemens , Pietschnig Rudolf 
Published: September 2016

AbstractThe thermal properties of a series of twenty‐four ionic liquids (ILs) have been determined by isothermal titration calorimetry (ITC) with the aim of simulating processes involving water sorption. For eleven water‐free ILs, the molecular structures have been determined by X‐ray crystallography in the solid state, which have been used to derive the molecular volumes of the ionic components of the ILs. Moreover, the structures reveal a high prevalence of hydrogen bonding in these compounds. A relationship between the molecular volumes and the experimentally determined energies of dilution could be established. The highest energies of dilution observed in this series were obtained for the acetate‐based ILs, which underlines their potential as working fluids in sorption‐based thermal energy storage systems.