bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting Impacts of the South Pacific Split Jet and the Southern Annular Mode Modulation on Southern Ocean Circulation and Biogeochemistry
Authors: Chiang John C. H. , Tokos K. S. , Lee S.‐Y. , Matsumoto K. 
Published: January 2018

AbstractA recent hypothesis postulated that paleoclimate changes to the Southern Hemisphere westerlies were characterized by the modulation of the wintertime South Pacific Split Jet. We explore this hypothesis further through simulating changes to the ocean circulation from Split Jet modulation, contrasting them against changes associated with the wintertime Southern Annular Mode (SAM). Three responses distinguish the Split Jet from the SAM impact on ocean circulation. (i) A weaker Split Jet strengthens the South Pacific subtropical gyre, leading to stronger western boundary currents and warming of the sea surface temperatures (SSTs) surrounding New Zealand. (ii) A positive SAM leads to an increase in the Antarctic Circumpolar Current and specifically Drake Passage throughflow. And (iii) a weaker Split Jet leads to increased formation of Subantartic Mode Water, whereas a positive SAM leads to increased Antarctic Intermediate Water. Both a weaker Split Jet and positive SAM lead to increased Southern Ocean meridional overturning circulation, though it is more pronounced for the latter. However, enhanced ventilation of deep water in both cases increases atmospheric pCO2 by only 1–3 ppm, because the associated cooling and efficient nutrient utilization in the model effectively negates the venting of deep ocean carbon. Both a weaker Split Jet and positive SAM enhance oxygenation of the deep ocean and intermediate waters but diminish oxygenation of the eastern equatorial Pacific. Our results provide guidance to distinguish SAM‐like changes from Split Jet‐like changes in paleoceanographic records, and we discuss the case of early deglacial transition to Heinrich 1.
No Change in Southern Ocean Circulation in the Indian Ocean From the Eocene Through Late Oligocene
Authors: Wright Nicky M. , Scher Howie D. , Seton Maria , Huck Claire E. , Duggan Brian D. 
Published: January 2018

AbstractDeciphering the evolution of Southern Ocean circulation during the Eocene and Oligocene has important implications for understanding the development of the Antarctic Circumpolar Current and transition to Earth's “icehouse” climate. To better understand ocean circulation patterns in the Indian Ocean sector of the Southern Ocean, we generated a new fossil fish tooth neodymium isotope record (εNd) from the upper Eocene to upper Oligocene sections (36–23 Ma) of Ocean Drilling Program Sites 744 and 748 (Kerguelen Plateau, Indian Ocean). Reconstructed seawater εNd values from fossil fish teeth are used to trace changes in water masses across ocean basins. The records from Site 748 and Site 744 reveal a gradual shift from εNd values around −6.5 to −7.5 in the late Eocene to εNd values between −7.5 and −8.3 by the late Oligocene, consistent with a Circumpolar Deep Water (CDW) influence at the Kerguelen Plateau throughout the Oligocene. We interpret the shift to less radiogenic values to reflect the increased export of Northern Component Water to the Southern Ocean, likely into the proto‐CDW. However, the records show no major change in water mass composition around the Kerguelen Plateau that would accompany an increase in Pacific throughflow related to the opening of Drake Passage and imply that Pacific throughflow via the Drake Passage occurred by the late Eocene. High‐frequency variability in ɛNd values at Site 744 is interpreted as an imprint of Oligocene glacial activity, with a particularly pronounced excursion at 32.6 Ma roughly coinciding with other glacial weathering indicators around Antarctica.
Measures of Model Performance Based On the Log Accuracy Ratio
Authors: Morley S. K. , Brito T. V. , Welling D. T. 
Published: January 2018

AbstractQuantitative assessment of modeling and forecasting of continuous quantities uses a variety of approaches. We review existing literature describing metrics for forecast accuracy and bias, concentrating on those based on relative errors and percentage errors. Of these accuracy metrics, the mean absolute percentage error (MAPE) is one of the most common across many fields and has been widely applied in recent space science literature and we highlight the benefits and drawbacks of MAPE and proposed alternatives. We then introduce the log accuracy ratio and derive from it two metrics: the median symmetric accuracy and the symmetric signed percentage bias. Robust methods for estimating the spread of a multiplicative linear model using the log accuracy ratio are also presented. The developed metrics are shown to be easy to interpret, robust, and to mitigate the key drawbacks of their more widely used counterparts based on relative errors and percentage errors. Their use is illustrated with radiation belt electron flux modeling examples.
Atomic Structure of Domain and Interphase Boundaries in Ferroelectric HfO2
Authors: Grimley Everett D. , Schenk Tony , Mikolajick Thomas , Schroeder Uwe , LeBeau James M. 
Published: January 2018

AbstractThough ferroelectric HfO2 thin films are now well characterized, little is currently known about their grain substructure. In particular, the formation of domain and phase boundaries requires investigation to better understand phase stabilization, switching, and phase interconversion. Here, scanning transmission electron microscopy is applied to investigate the atomic structure of boundaries in these materials. It is found that orthorhombic/orthorhombic domain walls and coherent orthorhombic/monoclinic interphase boundaries form throughout individual grains. The results inform how interphase boundaries can impose strain conditions that may be key to phase stabilization. Moreover, the atomic structure near interphase boundary walls suggests potential for their mobility under bias, which has been speculated to occur in perovskite morphotropic phase boundary systems by mechanisms similar to domain boundary motion.
Facile Synthesis of Nitrogen and Halogen Dual‐Doped Porous Graphene as an Advanced Performance Anode for Lithium‐Ion Batteries
Authors: Liu Huanlong , Tang Yufeng , Zhao Wei , Ding Wei , Xu Jijian , Liang Chenliang , Zhang Zhichao , Lin Tianquan , Huang Fuqiang 
Published: January 2018

AbstractNonmetal‐dual doped graphene has attracted considerable attention as high‐performance anode material for lithium‐ion batteries (LIBs) due to the synergistic effects of heteroatom dopants. Herein, nitrogen and halogen (including Cl, Br, and I) dual‐doped graphene is successfully synthesized by a general wet chemical method and lithium storage performance of N, Cl codoped graphene as anode material for LIBs is investigated in detail. The dual‐doped heteroatoms introduce abundant defects and expand the interlayer spacing of graphene to benefit lithium insertion and extraction. When used as a typical anode material, the N and Cl dual‐doped porous graphene reveals a high specific capacity of 1200 mA h g−1 at 0.1 A g−1 and 1010 mA h g−1 at 1.0 A g−1. The as‐prepared sample exhibits superior cycling performance, whose specific capacity remains 95% at 5.0 A g−1 after 1800 cycles. The excellent performance mainly stems from the synergistic effect of structure modification and heteroatom doping, and the capacitive effects are dictated by kinetical analysis. The synthesized nitrogen and halogen dual‐doped porous graphene is a promising anode material for LIBs.
Superlubricity of Graphite Induced by Multiple Transferred Graphene Nanoflakes
Authors: Li Jinjin , Gao Tianyang , Luo Jianbin 
Published: January 2018

Abstract2D or 3D layered materials, such as graphene, graphite, and molybdenum disulfide, usually exhibit superlubricity properties when sliding occurs between the incommensurate interface lattices. This study reports the superlubricity between graphite and silica under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes on the asperities of silica surfaces after the initial frictional sliding. The friction coefficient can be reduced to as low as 0.0003 with excellent robustness and is independent of the surface roughness, sliding velocities, and rotation angles. The superlubricity mechanism can be attributed to the extremely weak interaction and easy sliding between the transferred graphene nanoflakes and graphite in their incommensurate contact. This finding has important implications for developing approaches to achieve superlubricity of layered materials at the nanoscale by tribointeractions.
Ultraconformable Temporary Tattoo Electrodes for Electrophysiology
Authors: Ferrari Laura M. , Sudha Sudha , Tarantino Sergio , Esposti Roberto , Bolzoni Francesco , Cavallari Paolo , Cipriani Christian , Mattoli Virgilio , Greco Francesco 
Published: January 2018

AbstractElectrically interfacing the skin for monitoring personal health condition is the basis of skin‐contact electrophysiology. In the clinical practice the use of stiff and bulky pregelled or dry electrodes, in contrast to the soft body tissues, imposes severe restrictions to user comfort and mobility while limiting clinical applications. Here, in this work dry, unperceivable temporary tattoo electrodes are presented. Customized single or multielectrode arrays are readily fabricated by inkjet printing of conducting polymer onto commercial decal transfer paper, which allows for easy transfer on the user's skin. Conformal adhesion to the skin is provided thanks to their ultralow thickness (<1 µm). Tattoo electrode–skin contact impedance is characterized on short‐ (1 h) and long‐term (48 h) and compared with standard pregelled and dry electrodes. The viability in electrophysiology is validated by surface electromyography and electrocardiography recordings on various locations on limbs and face. A novel concept of tattoo as perforable skin‐contact electrode, through which hairs can grow, is demonstrated, thus permitting to envision very long‐term recordings on areas with high hair density. The proposed materials and patterning strategy make this technology amenable for large‐scale production of low‐cost sensing devices.
Mesoscopic 2D Charge Transport in Commonplace PEDOT:PSS Films
Authors: Honma Yuta , Itoh Keisuke , Masunaga Hiroyasu , Fujiwara Akihiko , Nishizaki Terukazu , Iguchi Satoshi , Sasaki Takahiko 
Published: January 2018

AbstractThe correlation between the transport properties and structural degrees of freedom of conducting polymers is a central concern in both practical applications and scientific research. In this study, the existence of mesoscopic 2D coherent charge transport in poly(3,4‐ethylenedioxythiophene):poly‐(styrenesulfonate) (PEDOT:PSS) film is demonstrated by performing structural investigations and high‐field magnetoconductance (MC) measurements in magnetic fields of up to 15 T. The researchers have succeeded in observing marked positive MCs reflecting 2D electronic states in a conventional drop‐cast film. This low‐dimensional feature is surprising, since PEDOT:PSS—a mixture of two different polymers—seems to be significantly different from crystalline 2D materials from the viewpoint of structural inhomogeneity, especially in popular drop‐cast thick films. The results of the structural experiments suggest that such 2D transport originates from the nanometer‐scale self‐assembled laminated structure, which is composed of PEDOT nanocrystals wrapped by insulating sheets consisting of amorphous PSSs. These results indicate that charge transport in the PEDOT:PSS film can be divided into two regimes: mesoscopic 2D coherent tunneling and macroscopic 3D hopping among 2D states. These findings elucidate the hieratical nature of charge transport in the PEDOT:PSS film, which can provide new insight into a recent engineering concern, i.e., the anisotropic conductance.
Der Bindungsmodus eines Tau‐Peptids mit Tubulin
Authors: Kadavath Harindranath , Cabrales Fontela Yunior , Jaremko Mariusz , Jaremko Łukasz , Overkamp Kerstin , Biernat Jacek , Mandelkow Eckhard , Zweckstetter Markus 
Published: January 2018

AbstractDas Mikrotubuli‐assoziierte Protein Tau fördert die Polymerisation von Tubulin und beeinflusst die Mikrotubuli‐Funktion. Aufgrund einer inhärenten Flexibilität in der Tau‐Tubulin‐Wechselwirkung sind die strukturellen Grundlagen dieser Interaktion weitestgehend unbekannt. Mithilfe von Liganden‐Rezeptor‐spezifischen NMR‐Methoden und positionsspezifischer Mutagenese wird nachgewiesen, dass die Region N‐terminal zu den vier Mikrotubuli‐bindenden Wiederholungssequenzen an die Oberfläche von α‐Tubulin bindet. Der Bindungsprozess ist komplex, umfasst eine partielle Kupplung verschiedener Tau‐Aminosäuren und wird durch Tau‐Phosphorylierung an Y394 und S396 beeinflusst. Die Untersuchungen stärken die Hypothese einer engen Verbindung zwischen Tau‐Phosphorylierung und ‐Bindung an Tubulin. Ferner unterstreichen die Ergebnisse die Stärke der INPHARMA‐NMR‐Methode für die Analyse von Wechselwirkungen zwischen intrinsisch ungeordneten Peptiden/Proteinen und ihren molekularen Partnern.
Palladium‐Catalyzed Enantioselective Desymmetrizing Aza‐Wacker Reaction: Development and Application to the Total Synthesis of (−)‐Mesembrane and (+)‐Crinane
Authors: Bao Xu , Wang Qian , Zhu Jieping 
Published: January 2018

AbstractReported is an unprecedented catalytic enantioselective desymmetrizing aza‐Wacker reaction. In the presence of a catalytic amount of a newly developed Pd(CPA)2(MeCN)2 catalyst (CPA=chiral phosphoric acid), a pyrox ligand, and molecular oxygen, cyclization of properly functionalized prochiral 3,3‐disubstituted cyclohexa‐1,4‐dienes afforded enantioenriched cis‐3a‐substituted tetrahydroindoles in good yields with excellent enantioselectivities. A cooperative effect between the phosphoric acid and the pyrox ligand ensured efficient transformation. This reaction was tailor‐made for Amaryllidaceae and Sceletium alkaloids as illustrated by its application in the development of the concise and divergent total synthesis of (−)‐mesembrane and (+)‐crinane.
Multiple Binding Sites Contribute to the Mechanism of Mixed Agonistic and Positive Allosteric Modulators of the Cannabinoid CB1 Receptor
Authors: Saleh Noureldin , Hucke Oliver , Kramer Gert , Schmidt Esther , Montel Florian , Lipinski Radoslaw , Ferger Boris , Clark Timothy , Hildebrand Peter W. , Tautermann Christofer S. 
Published: January 2018

AbstractThe cannabinoid CB1 receptor (CB1R) is an abundant metabotropic G‐protein‐coupled receptor that has been difficult to address therapeutically because of CNS side effects exerted by orthosteric drug candidates. Recent efforts have focused on developing allosteric modulators that target CB1R. Compounds from the recently discovered class of mixed agonistic and positive allosteric modulators (Ago‐PAMs) based on 2‐phenylindoles have shown promising functional and binding properties as CB1R ligands. Here, we identify binding modes of both the CP 55,940 agonist and GAT228, a 2‐phenylindole allosteric modulator, by using our metadynamics simulation protocol, and quantify their affinity and cooperativity by atomistic simulations. We demonstrate the involvement of multiple adjunct binding sites in the Ago‐PAM characteristics of the 2‐phenylindole modulators and explain their ability to compete with orthosteric agonists at higher concentrations. We validate these results experimentally by showing the contribution of multiple sites on the allosteric binding of ZCZ011, another homologous member of the class, together with the orthosteric agonist.
RuBisCO‐Inspired CO2 Activation and Transformation by an Iridium(I) Complex
Authors: Langer Jens , Hamza Andrea , Pápai Imre 
Published: January 2018

AbstractThe synthesis of a new iridium(I) complex containing an enamido phosphine anion (dbuP−) and its unique reactivity with CO2 is reported. The complex binds two equivalents of CO2 and initiates a highly selective reaction cascade. The reaction leads to the reversible cleavage of CO2 and the enamido ligand as well. Computational analysis points to the existence of a relatively stable Ir‐CO2 complex as a reaction intermediate prior to CO2 cleavage, which was confirmed experimentally. The observed transformation resembles several aspects of enzymatic CO2 fixation by RuBisCO.
Sustainability assessment of combined steam and dry reforming versus tri‐reforming of methane for syngas production
Authors: Chen Liwen , Gangadharan Preeti , Lou Helen H. 
Published: January 2018

AbstractSynthesis gas (syngas) is a versatile intermediate in the production of valuable chemicals and fuel, such as methanol, dimethyl ether, ethylene, propylene, and the Fischer–Tropsch fuel. Combining steam reforming and dry reforming (SR + DR) routes can produce syngas with a suitable H2:CO molar ratio (around 2:1) for Fischer–Tropsch synthesis. The newly proposed tri‐reforming (TR) route at experimental scale was a capable alternative to produce syngas in a single reformer with potential benefits such as energy savings and waste flue gas utilization. In this paper, sustainability assessment of SR + DR and TR routes adopting quantifiable indices in economic, environmental, and safety dimensions at industrial scale is performed based on process simulation models. Results show that TR route outperforms SR + DR route in all 3 dimensions. Sensitivity analysis of natural gas price fluctuation does not alter the conclusion. A sustainable root cause analysis is also applied on the SR + DR which identifies root causes affecting its sustainability with the aid of visualization tools such as Pareto chart and fish bone diagram.
Preparation and electrochemical properties of polyaniline/reduced graphene oxide composites
Authors: Li Yunlong , Zheng Yuying 
Published: January 2018

ABSTRACTPolyaniline (PANI)/reduced graphene oxide (rGO) composites were synthesized by in situ oxidative polymerization of aniline on reduced graphene sheets. Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, transmission electron microscopy, and scanning electron microscopy were used to characterize the composites. The results indicated PANI/rGO composites were produced and contained covalent bonds between the functional groups of PANI and rGO. A uniform coating of PANI on the rGO sheets had a synergistic effect on the properties of the composites. The electrochemical properties of the PANI/rGO composites produced using different feed ratios of aniline to rGO were studied. The results showed that the composites exhibited a maximum specific capacitance of 797.5 F/g at 0.5 A/g and minimum charge transfer resistance of 0.98 Ω when the feed ratio of aniline to rGO was 2:1. These values were superior to those of pure PANI and rGO. The composites also displayed excellent cycling stability, with specific capacitance retention of 92.43% after 1000 cycles. These stable structural composites show promise for the development of new supercapacitor applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46103.
Effect of polyurethane sizing on carbon fibers surface and interfacial adhesion of fiber/polyamide 6 composites
Authors: Zhang Tao , Zhao Yueqing , Li Hongfu , Zhang Boming 
Published: January 2018

ABSTRACTCommercial epoxy sized carbon fibers (CFs) or unsized CFs have poor interfacial adhesion with polyamide 6 (PA6). Here, CFs are coated with polyurethane (PU) and their surface properties in terms of surface chemistry, contact angle, roughness, and morphology, are investigated. The results of Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy demonstrate PU sizing evidently increases the quantity of polar functional groups on the CFs surface. The surface energy of the PU sized fiber is calculated according to the Owens–Wendt method. Compared with unsized fibers, the contact angle of PU sized fibers is decreased while their total surface energy is increased, indicating superior wettability. Moreover, transverse fiber bundle tests are performed to determine the interfacial adhesion between the CFs and PA6 matrix. The transverse fiber bundle strength of unsized CF is measured to be 12.57 MPa. For PU sized CFs processed with sizing concentration of 1.2%, this value is increased to 24.35 MPa, showing an increase of more than 90%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46111.
Preparation of a novel styrene copolymer: Simultaneously improving the thermal stability and toughness
Authors: Cui Jianguang , Zhu Changjiang , He Mingshan , Ke Zhenkun , Liu Yu , Tai Qilong , Xiao Xifu , Hu Yuan 
Published: January 2018

ABSTRACTIn order to improve the flame retardancy of polystyrene, a phosphorus‐ and nitrogen‐containing monomer, N,N‐tetramethyl‐bis(phospohonate)‐2‐hydroxyethyl bis(methylene) amine acrylate (BC2NP2), was synthesized and characterized, and then incorporated into various amounts of polystyrene via radical emulsion copolymerization. The copolymers prepared were characterized by Fourier transform infrared, nuclear magnetic resonance spectra, transmission electron microscopy, differential scanning calorimetry, thermalgravimetric analysis, microscale combustion calorimeter, dynamic mechanical analysis, and impact tests. The results showed that all the copolymers had well spherical core–shell structure. Notably, despite a few amounts of the BC2NP2 units in copolymers, all the copolymers exhibited significantly enhanced thermal stability, decreased glass transition temperature, and reduced flammability. Furthermore, from dynamic mechanical analysis and impact tests, it was observed the storage modulus was decreased and the impact strength had a certain degree of improvement with the incorporation of commoner. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46120.
Effects of Streptomycin Administration on Increases in Skeletal Muscle Fiber Permeability and Size Following Eccentric Muscle Contractions
Authors: Hayao Keishi , Tamaki Hiroyuki , Nakagawa Kouki , Tamakoshi Keigo , Takahashi Hideaki , Yotani Kengo , Ogita Futoshi , Yamamoto Noriaki , Onishi Hideaki 
Published: January 2018

ABSTRACTThe purpose of this study was to investigate the preventive effect of streptomycin (Str) administration on changes in membrane permeability and the histomorphological characteristics of damaged muscle fibers following eccentric contraction (ECC ). Eighteen 7‐week‐old male Fischer 344 rats were randomly assigned to three groups: control (Cont), ECC, and ECC with Str (ECC + Str). The tibialis anterior (TA) muscles in both ECC groups were stimulated electrically and exhibited ECC. Evans blue dye (EBD), a marker of muscle fiber damage associated with increased membrane permeability, was injected 24 hr before TA muscle sampling. The number of EBD‐positive fibers, muscle fiber cross‐sectional area (CSA), and roundness were determined via histomorphological analysis. The ECC intervention resulted in an increased fraction of EBD‐positive fibers, a larger CSA, and decreased roundness. The fraction of EBD‐positive fibers was 79% lower in the ECC + Str group than in the ECC group. However, there was no difference in the CSA and roundness of the EBD‐positive fibers between the two ECC groups. These results suggest that Str administration can reduce the number of myofibers that increase membrane permeability following ECC, but does not ameliorate the extent of fiber swelling in extant EBD‐positive fibers. Anat Rec, 301:1096–1102, 2018. © 2018 Wiley Periodicals, Inc.