bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Geophysical Perspective on the Bulk Composition of Mars
Authors: Khan A. , Liebske C. , Rozel A. , Rivoldini A. , Nimmo F. , Connolly J. A. D. , Plesa A.‐C. , Giardini D. 
Published: November 2017

AbstractWe invert the Martian tidal response and mean mass and moment of inertia for chemical composition, thermal state, and interior structure. The inversion combines phase equilibrium computations with a laboratory‐based viscoelastic dissipation model. The rheological model, which is based on measurements of anhydrous and melt‐free olivine, is both temperature and grain size sensitive and imposes strong constraints on interior structure. The bottom of the lithosphere, defined as the location where the conductive geotherm meets the mantle adiabat, occurs deep within the upper mantle (∼200–400 km depth) resulting in apparent upper mantle low‐velocity zones. Assuming an Fe‐FeS core, our results indicate (1) a mantle with a Mg# (molar Mg/Mg+Fe) of ∼0.75 in agreement with earlier geochemical estimates based on analysis of Martian meteorites; (2) absence of bridgmanite‐ and ferropericlase‐dominated basal layer; (3) core compositions (15–18.5 wt% S), core radii (1,730–1,840 km), and core‐mantle boundary temperatures (1620–1690°C) that, together with the eutectic‐like core compositions, suggest that the core is liquid; and (4) bulk Martian compositions with a Fe/Si (weight ratio) of 1.66–1.81. We show that the inversion results can be used in tandem with geodynamic simulations to identify plausible geodynamic scenarios and parameters. Specifically, we find that the inversion results are largely reproducible by stagnant lid convection models for a range of initial viscosities (∼1018–1020 Pa s) and radioactive element partitioning between crust and mantle around 0.01–0.1. The geodynamic models predict a mean surface heat flow between 15 and 25 mW/m2.
Probabilistic Tsunami Hazard Analysis: Multiple Sources and Global Applications
Authors: Grezio Anita , Babeyko Andrey , Baptista Maria Ana , Behrens Jörn , Costa Antonio , Davies Gareth , Geist Eric L. , Glimsdal Sylfest , González Frank I. , Griffin Jonathan , Harbitz Carl B. , LeVeque Randall J. , Lorito Stefano , Løvholt Finn , Omira Rachid , Mueller Christof , Paris Raphaël , Parsons Tom , Polet Jascha , Power William , Selva Jacopo , Sørensen Mathilde B. , Thio Hong Kie 
Published: November 2017

AbstractApplying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run‐up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework.
Electron Fluxes at Geostationary Orbit From GOES MAGED Data
Authors: Sillanpää Ilkka , Ganushkina N. Yu. , Dubyagin S. , Rodriguez J. V. 
Published: November 2017

AbstractElectron behavior in energies below 200 keV at geostationary orbit has significance for satellite operations due to charging effects on spacecraft. Five years of keV energy electron measurements by the geostationary GOES‐13 satellite's MAGnetospheric Electron Detector (MAGED) instrument has been analyzed. A method for determining flight direction integrated fluxes is presented. The electron fluxes at the geostationary orbit are shown to have significant dependence on solar wind speed and interplanetary magnetic field (IMF) BZ: increased solar wind speed correlates with higher electron fluxes with all magnetic local times while negative IMF BZ increases electron fluxes in the 0 to 12 magnetic local time sector. A predictive empirical model for electron fluxes in the geostationary orbit for energies 40, 75, and 150 keV was constructed and is presented here. The empirical model is dependent on three parameters: magnetic local time, solar wind speed, and IMF BZ.
Crustal Structure at a Young Continental Rift: A Receiver Function Study From the Tanganyika Rift
Authors: Hodgson Isabel , Illsley‐Kemp Finnigan , Gallacher Ryan J. , Keir Derek , Ebinger Cynthia J. , Mtelela Khalfan 
Published: November 2017

AbstractThe southern Tanganyika Rift, within the Western rift, Africa, has earthquakes to depths of 37 km, yet few constraints exist on crustal thickness, or of early stage rifting processes in apparently amagmatic rift sectors. The aim of the TANGA14 experiment was to constrain bulk crustal properties to test whether magmatic processes modify the lithosphere in areas of deep seismicity, and the degree of lithospheric thinning. We use 11 broadband seismometers to implement receiver function analysis using H‐κ stacking, a method sensitive to crustal thickness and VP/VS ratio, to determine bulk crustal properties. Analyses include extensive error analysis through bootstrap, variance, and phase‐weighted stacking. Results show the Archean Tanzanian Craton and Bangweulu Block are characterized by VP/VS ratios of 1.75–1.77, implying a felsic bulk composition. Crust beneath the fault‐bounded basins has high VP/VS (>1.9). Anorthosite bodies and surface sediments within the region may contribute to localized high VP/VS. However, elevated VP/VS values within fault‐bounded extensional basins where elevated heat flow, hydrothermal vent sites, and deep earthquakes are observed suggest that magma may be intruding the lower crust beneath the southern Tanganyika Rift. Crustal thicknesses on/near the relatively unextended Tanzanian craton and Bangweulu Block are 41.6–42.0 km. This contrasts with the Tanganyika Rift where crustal thicknesses are 31.6 km to 39 km from north to south. Our results provide evidence for ~20% crustal thinning localized to fault‐bounded basins. Taken together, they suggest a previously unrecognized role of magma intrusion in early stage continental rifting in the Western rift, Africa.
Synthesis and Properties of a Photopatternable Lithium‐Ion Conducting Solid Electrolyte
Authors: Choi Christopher S. , Lau Jonathan , Hur Janet , Smith Leland , Wang Chunlei , Dunn Bruce 
Published: November 2017

AbstractOne of the important considerations for the development of on‐chip batteries is the need to photopattern the solid electrolyte directly on electrodes. Herein, the photopatterning of a lithium‐ion conducting solid electrolyte is demonstrated by modifying a well‐known negative photoresist, SU‐8, with LiClO4. The resulting material exhibits a room temperature ionic conductivity of 52 µS cm−1 with a wide electrochemical window (>5 V). Half‐cell galvanostatic testing of 3 µm thin films spin‐coated on amorphous silicon validates its use for on‐chip energy‐storage applications. The modified SU‐8 possesses excellent mechanical integrity, is thermally stable up to 250 °C, and can be photopatterned with micrometer‐scale resolution. These results present a promising direction for the integration of electrochemical energy storage in microelectronics.
Monogamy of Einstein‐Podolsky‐Rosen Steering in the Background of an Asymptotically Flat Black Hole
Authors: Wang Jieci , Jing Jiliang , Fan Heng 
Published: November 2017

AbstractWe study the behavior of monogamy deficit and monogamy asymmetry for Einstein‐Podolsky‐Rosen steering of Gaussian states under the influence of the Hawking effect. We demonstrate that the monogamy of quantum steering shows an extreme scenario in the curved spacetime: the first part of a tripartite system cannot individually steer two other parties, but it can steer the collectivity of the remaining two parties. We also find that the monogamy deficit of Gaussian steering, a quantifier of genuine tripartite steering, are generated due to the influence of the Hawking thermal bath. Our results elucidate the structure of quantum steering in tripartite quantum systems in curved spacetime.
Fraction‐Dimensional Accessible Solitons in a Parity‐Time Symmetric Potential
Authors: Zhong Wei‐Ping , Belić Milivoj R. , Zhang Yiqi 
Published: November 2017

AbstractBy using the modified Snyder‐Mitchell (MSM) model, which can describe the propagation of a paraxial beam in fractional dimensions (FDs), we find the exact "accessible soliton” solutions in the strongly nonlocal nonlinear media with a self‐consistent parity‐time (PT) symmetric complex potential. The exact solutions are constructed with the help of two special functions: the complex Gegenbauer and the generalized Laguerre polynomials in polar coordinates, parametrized by two nonnegative integer indices ‐ the radial and azimuthal mode numbers (n,m), and the beam modulation depth. By the choice of different soliton parameters, the intensity and angular profiles display symmetric and asymmetric structures. We believe that it is important to explore the MSM model in FDs and PT‐symmetric potentials, for a better understanding of nonlinear FD physical phenomena. Different physical systems in which the model might be of relevance are briefly discussed.
Übergangsmetall‐π‐Komplexierung eines Tetrahalogendiborans
Authors: Braunschweig Holger , Dewhurst Rian D. , Jiménez‐Halla J. Oscar C. , Matito Eduard , Muessig Jonas H. 
Published: November 2017

AbstractDie Reaktion von Tetraioddiboran (B2I4) mit trans‐[Pt(BI2)I(PCy3)2] führte zur Isolierung des Diplatin(II)‐Komplexes [{(Cy3P)(I2B)Pt}2(μ2:η3:η3‐B2I4)], der durch den verbrückenden dianionischen Diboranyl‐Liganden [B2I4]2−stabilisiert wird. Der Komplex ist der erste Übergangsmetallkomplex mit einem dianionischen Diboranyl‐Liganden und ist ebenso das erste Beispiel einer intakten Koordination einer B2X4‐Einheit (X=Halogen) an ein Metallzentrum.
Katalyse durch N‐heterocyclische Carbene über Azoliumdienolate: eine effiziente Strategie für enantioselektive Funktionalisierungen an entfernten Positionen
Authors: Chen Xiang‐Yu , Liu Qiang , Chauhan Pankaj , Enders Dieter 
Published: November 2017

AbstractDie Katalyse durch N‐heterocyclische Carbene (NHCs) ist zu einer effizienten Strategie in der organischen Synthese geworden. In den letzten Jahren wurden etliche Übersichtsartikel veröffentlicht, die NHC‐katalysierte Umwandlungen unter Beteiligung von Breslow‐Intermediaten, Acylazolium‐ und α,β‐ungesättigten Acylazolium‐Intermediaten, Homoenolatäquivalenten sowie Azoliumenolaten behandelten. Doch erst in letzter Zeit wurden durch NHCs erzeugte Azoliumdienolat‐Intermediate in der asymmetrischen Synthese, insbesondere in Cycloadditionen, zur Funktionalisierung entfernter Positionen genutzt. Dieser Kurzaufsatz beleuchtet alle Entwicklungen und neuere Fortschritte für NHC‐katalysierte asymmetrische Cycloadditionen, in denen Azoliumdienolat‐Intermediate auftreten.
Transition‐Metal π‐Ligation of a Tetrahalodiborane
Authors: Braunschweig Holger , Dewhurst Rian D. , Jiménez‐Halla J. Oscar C. , Matito Eduard , Muessig Jonas H. 
Published: November 2017

AbstractThe reaction of tetraiododiborane (B2I4) withtrans‐[Pt(BI2)I(PCy3)2] gives rise to the diplatinum(II) complex [{(Cy3P)(I2B)Pt}2(μ2:η3:η3‐B2I4)], which is supported by a bridging diboranyl dianion ligand [B2I4]2−. This complex is the first transition‐metal complex of a diboranyl dianion, as well as the first example of intact coordination of a B2X4(X=halide) unit of any type to a metal center.
N‐Heterocyclic Carbene Catalysis via Azolium Dienolates: An Efficient Strategy for Remote Enantioselective Functionalizations
Authors: Chen Xiang‐Yu , Liu Qiang , Chauhan Pankaj , Enders Dieter 
Published: November 2017

AbstractN‐heterocyclic carbene (NHC) catalysis has emerged as a powerful strategy in organic synthesis. In recent years a number of reviews have been published on NHC‐catalyzed transformations involving Breslow intermediates, acyl azoliums, α,β‐unsaturated acyl azoliums, homoenolate equivalents, and azolium enolates. However, the azolium dienolate intermediates generated by NHCs have been employed in asymmetric synthesis only very recently, especially in cycloadditions dealing with remote functionalization. This Minireview highlights all the developments and the new advances in NHC‐catalyzed asymmetric cycloaddition reactions involving azolium dienolate intermediates.
Assessment of multiple cytochrome P450 activities in metabolically inactivated human liver microsomes and roles of P450 2C isoforms in reaction phenotyping studies
Authors: Murayama Norie , Yajima Kanako , Hikawa Mikiko , Shimura Kanami , Ishii Yu , Takada Masaki , Uno Yasuhiro , Utoh Masahiro , Iwasaki Kazuhide , Yamazaki Hiroshi 
Published: November 2017

AbstractThe fraction of substrate metabolized (fm) can be used to estimate drug interactions and can be determined by comparison of the intrinsic clearances (CLint) of victim drugs obtained from inhibited and uninhibited hepatic enzymes. Commercially available human liver microsomes were recently developed in which one cytochrome P450 (P450) isoform is selectively inactivated. These inactivated liver microsomes were used to evaluate the roles of P450 2C isoforms in the depletion and oxidation of probe substrates. Determination of CLint with sets of control and P450 2C9‐inactivated liver microsomes yielded fm,P450 2C9 values of 0.69–1.0 for celecoxib, diclofenac and warfarin. Apparent minor contributions of P450 1A2/2C8/3A4 were seen in depletion assays, yielding ~1 for the sum of the fm values. Selectively inactivated liver microsomes were thereby shown to be potentially useful for determining the in vitro fm values for major P450 2C9 contributions to substrate oxidations. Metabolite formations from diclofenac and warfarin were suppressed by 62–84% by the replacement of control liver microsomes with P450 2C9‐inactivated liver microsomes. R‐, S‐ and racemic omeprazole and troglitazone oxidation activities by liver microsomes at multiple substrate concentrations were suppressed by 26–36% and 22–50%, respectively, when P450 2C19‐ and 2C8‐inactivated liver microsomes were used in place of control liver microsomes. This study provides important information to help elucidate the different roles of P450 isoforms in metabolite formation at different substrate concentrations. The data obtained allow the fractions metabolized to be calculated for victim drugs.
Improving the Thermostability and Catalytic Efficiency of the Subunit‐Fused Nitrile Hydratase by Semi‐Rational Engineering
Authors: Xia Yuanyuan , Cui Wenjing , Cheng Zhongyi , Peplowski Lukasz , Liu Zhongmei , Kobayashi Michihiko , Zhou Zhemin 
Published: November 2017

AbstractNitrile hydratase (NHase, EC 4.2.1.84) is a key enzyme in the hydration of nitriles to their corresponding amides and is widely used in the industrial production of highly purified acrylamide and nicotinamide. However, the poor thermostability of NHase is the major factor preventing its extensive industrial application. Here, a semi‐rational design approach based on the pmut scan application of Rosetta 3.4 and molecular dynamics (MD) simulations was used to improve the thermostability of a subunit‐fused nitrile hydratase from Pseudomonas putida NRRL‐18668 (Fus‐NHase). A small mutant library was constructed, and three mutants, B‐M150C, B‐T173Y, and B‐S189E, with half‐life increases at 50 °C of 32 %, 7 %, and 107 %, respectively, were obtained. Additionally, the kcat/Km values of B‐M150C, B‐T173Y, and B‐S189E were 1.1‐, 1.5‐, and 2.2‐fold higher, respectively, than that of Fus‐NHase. This study provides an effective strategy for improving protein thermostability and catalytic efficiency.
Proton Transfer Reaction Dynamics of Pyranine in DMSO/Water Mixtures
Authors: Awasthi Ankur A. , Singh Prabhat K. 
Published: November 2017

AbstractPhotoinduced intermolecular excited‐state proton transfer (ESPT) reactions are ubiquitous in chemistry and biology. ESPT reactions are extremely sensitive to the nature of water molecules in its microenvironment and thus serve as a sensitive reporter for the water structure and dynamics in a system. Herein, the photoinduced intermolecular ESPT reaction of 8‐hydroxypyrene‐1,3,5‐trisulfonic acid (HPTS, also known as pyranine) has been investigated in various DMSO/water mixtures by using steady‐state and time‐resolved emission spectroscopy. The DMSO/water binary mixture yields an interesting and anomalous behavior for the proton transfer reaction dynamics of HPTS at a mole fraction of DMSO (XDMSO) of 0.41–0.51, which has also been previously investigated and projected as an anomalous region by molecular dynamics simulation and other experimental techniques. The extreme slowdown of the proton transfer reaction observed at XDMSO=0.41–0.51 has been attributed to the slow solvation dynamics, as well as the non‐availability of free water molecules at this composition, which are required to solvate the newly generated proton. These observations have been also corroborated by time‐resolved area‐normalized emission spectra. The dimensionality of the proton diffusion process has been investigated by analyzing the geminate recombination process, and is found to be significantly different in DMSO/water mixtures (XDMSO=0.41–0.51) compared with three‐dimensional proton diffusion in neat water.
Production of Jet Fuel‐Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts
Authors: Wang Hongliang , Wang Huamin , Kuhn Eric , Tucker Melvin P. , Yang Bin 
Published: November 2017

AbstractSuper Lewis acids containing the triflate anion [e.g., Hf(OTf)4, Ln(OTf)3, In(OTf)3, Al(OTf)3] and noble metal catalysts (e.g., Ru/C, Ru/Al2O3) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium‐based catalysts. When a technical lignin derived from a pilot‐scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote deoxygenation reactions catalyzed by super Lewis acids.
A novel analog switch for high‐precision switched‐capacitor applications
Authors: Naghavi Saeed , Sharifi Niloofar , Abrishamifar Adib 
Published: November 2017

SummaryThe performance of a switched‐capacitor circuit strongly depends on its analog switches. This paper introduces a new technique to design a high‐precision analog metal‐oxide‐semiconductor switch for switched‐capacitor applications. The accuracy of analog switches is a critical parameter to determine overall performance of the discrete‐time analog systems. To satisfy the accuracy requirements of the switch, a novel technique to minimize the charge injection and clock feedthrough errors by using a very simple structure is proposed. Moreover, an innovative approach to increase the OFF resistance of the switch and consequently minimizing its leakage current is presented. To evaluate the performance of the proposed switch, simulations are done in TSMC 0.18μm standard complementary metal‐oxide‐semiconductor technology with BSIM3V3 device models. The ON and OFF resistances of the switch are one of the most important factors that should be considered while investigating analog switches. The ON resistance of the proposed switch is less than 560Ω over entire input signal range which completely satisfies the tracking bandwidth requirements. In addition, since the proposed switch provides an ultrahigh OFF resistance in the range of several GΩs, the leakage current of the proposed switch is negligible. Simulation results also show that switch‐induced errors are significantly eliminated by using the proposed cancellation technique. The output error charge due to charge injection and clock feedthrough over a wide range of input signal variation is very low (less than 1.6 fC). Moreover, simulation results show that the proposed switch achieves signal to noise plus distortion ratio of 80.55 dB, effective number of bits of 13.08, total harmonic distortion of −81.41 dB, and spurious‐free dynamic range of 87.7 dB for a 2.5‐MHz sinusoidal input of 800‐mV peak‐to‐peak amplitude at 200‐MHz sampling rate with a 1.8‐V supply voltage. Consequently, the simulation results verify that the proposed switch can significantly improve the dynamic and static performances of a switched‐capacitor circuit.
The axonal endoplasmic reticulum: One organelle—many functions in development, maintenance, and plasticity
Authors: Luarte Alejandro , Cornejo Víctor Hugo , Bertin Francisca , Gallardo Javiera , Couve Andrés 
Published: November 2017

ABSTRACTThe endoplasmic reticulum (ER) is highly conserved in eukaryotes and neurons. Indeed, the localization of the organelle in axons has been known for nearly half a century. However, the relevance of the axonal ER is only beginning to emerge. In this review, we discuss the structure of the ER in axons, examining the role of ER‐shaping proteins and highlighting reticulons. We analyze the multiple functions of the ER and their potential contribution to axonal physiology. First, we examine the emerging roles of the axonal ER in lipid synthesis, protein translation, processing, quality control, and secretory trafficking of transmembrane proteins. We also review the impact of the ER on calcium dynamics, focusing on intracellular mechanisms and functions. We describe the interactions between the ER and endosomes, mitochondria, and synaptic vesicles. Finally, we analyze available proteomic data of axonal preparations to reveal the dynamic functionality of the ER in axons during development. We suggest that the dynamic proteome and a validated axonal interactome, together with state‐of‐the‐art methodologies, may provide interesting research avenues in axon physiology that may extend to pathology and regeneration. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 181–208, 2018