bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraplate rotational deformation induced by faults
Authors: Dembo Neta , Hamiel Yariv , Granot Roi 
Published: October 2015

AbstractVertical axis rotations provide important constraints on the tectonic history of plate boundaries. Geodetic measurements can be used to calculate interseismic rotations, whereas paleomagnetic remanence directions provide constraints on the long‐term rotations accumulated over geological timescales. Here we present a new mechanical modeling approach that links between intraplate deformational patterns of these timescales. We construct mechanical models of active faults at their locked state to simulate the presumed to be elastic interseismic deformation rate observed by GPS measurements. We then apply a slip to the faults above the locking depth to simulate the long‐term deformation of the crust from which we derive the accumulated rotations. We test this approach in northern Israel along the Dead Sea Fault and Carmel‐Gilboa fault system. We use 12 years of interseismic GPS measurements to constrain a slip model of the major faults found in this region. Next, we compare the modeled rotations against long‐term rotations determined based on new primary magnetic remanence directions from 29 sites with known age. The distributional pattern of site mean declinations is in general agreement with the vertical axis rotations predicted by the mechanical model, both showing anomalously high rotations near fault tips and bending points. Overall, the results from northern Israel validate the effectiveness of our approach and indicate that rotations induced by motion along faults may act in parallel (or alone) to rigid block rotations. Finally, the new suggested method unravels important insights on the evolution (timing, magnitude, and style) of deformation along major faults.
Tectonic expression of an active slab tear from high‐resolution seismic and bathymetric data offshore Sicily (Ionian Sea)
Authors: Gutscher Marc‐André , Dominguez Stephane , de Lepinay Bernard Mercier , Pinheiro Luis , Gallais Flora , Babonneau Nathalie , Cattaneo Antonio , Le Faou Yann , Barreca Giovanni , Micallef Aaron , Rovere Marzia 
Published: October 2015

AbstractSubduction of a narrow slab of oceanic lithosphere beneath a tightly curved orogenic arc requires the presence of at least one lithospheric scale tear fault. While the Calabrian subduction beneath southern Italy is considered to be the type example of this geodynamic setting, the geometry, kinematics and surface expression of the associated lateral, slab tear fault offshore eastern Sicily remain controversial. Results from a new marine geophysical survey conducted in the Ionian Sea, using high‐resolution bathymetry and seismic profiling reveal active faulting at the seafloor within a 140 km long, two‐branched fault system near Alfeo Seamount. The previously unidentified 60 km long NW trending North Alfeo Fault system shows primarily strike‐slip kinematics as indicated by the morphology and steep‐dipping transpressional and transtensional faults. Available earthquake focal mechanisms indicate dextral strike‐slip motion along this fault segment. The 80 km long SSE trending South Alfeo fault system is expressed by one or two steeply dipping normal faults, bounding the western side of a 500+ m thick, 5 km wide, elongate, syntectonic Plio‐Quaternary sedimentary basin. Both branches of the fault system are mechanically capable of generating magnitude 6–7 earthquakes like those that struck eastern Sicily in 1169, 1542, and 1693.
Versatile (Pentamethylcyclopentadienyl)rhodium‐2,2′‐Bipyridine (Cp*Rh‐bpy) Catalyst for Transfer Hydrogenation of N‐Heterocycles in Water
Authors: Zhang Lingjuan , Qiu Ruiying , Xue Xiao , Pan Yixiao , Xu Conghui , Li Huanrong , Xu Lijin 
Published: October 2015

AbstractAn investigation employing the catalytic system consisting of (pentamethylcyclopentadienyl)rhodium dichloride dimer [Cp*RhCl2]2 and 2,2′‐bipyridine (bpy) for transfer hydrogenation of a variety of quinoxalines, quinoxalinones, quinolines and indoles under aqueous conditions with formate as the hydrogen source is reported. This approach provides various tetrahydroquinoxalines, dihydroquinoxalinones, tetrahydroquinolines and indolines in good to excellent yields. The activity of the catalyst towards quinoxalines and quinoxalinones is excellent, with a substrate to catalyst ratio (S/C) of 10000 being feasible. The choice of ligand is critical to the catalysis, and the aqueous phase reduction is shown to be highly pH‐dependent, with acidic pH values needed for optimal reduction. The catalyst is easy to access, and the reaction is operationally simple without requiring an inert atmosphere.magnified image
Dynamic Stereochemistry of Monobridged Tetraarylethene Naphthologues. Variations of Bistricyclic Aromatic Enes
Authors: Assadi Naela , Pogodin Sergey , Agranat Israel 
Published: October 2015

AbstractDynamic 1H NMR experiments on monobridged tetraarylethenes (bistricyclic aromatic enes devoid of one bridge, BAE‐1s) revealed the conformational processes in 13–15 (BAE‐1 s, X=S, Se, and Te) and in their respective thiiranes. The experimental energy barriers ΔG≠c were found to be 59.0, 72.2, and 67.9 kJ mol−1 for 13, 14, and 15, and 63.4, 64.4, and 61.3 kJ mol−1 for 26, 27, and 28, respectively. In contrast to the bis(α‐naphthyl) derivatives 13–15, no dynamic processes were detected for the bis(β‐naphthyl) derivatives 16–20. These results are in agreement with the mechanisms of enantiomerization of 13–15 derived from DFT calculations. The folded‐twisted global minima conformers of 13–15 undergo enantiomerization via inversion of the central ring, accompanied by rotation of the α‐naphthyl substituents. The B3LYP/SDD free energy barriers, ΔG298, for the enantiomerizations of BAE‐1s 13–15 are 57.4, 66.6, and 80.2 kJ mol−1, respectively. The minima and transition‐state conformations are chiral and the enantiomerization may proceed via chiral pathways.
Nichtkonjugierte Polymerpunkte ohne Fluorophoreinheiten mit gesteigerter Emission durch Vernetzung
Authors: Zhu Shoujun , Song Yubin , Shao Jieren , Zhao Xiaohuan , Yang Bai 
Published: October 2015

AbstractNichtkonjugierte Polymerpunkte (NCPDs) werden als neuartiges fluoreszierendes Material vorgestellt. Die NCPDs enthalten anstelle typischer konjugierter fluorophorer Gruppen nur Sub‐Fluorophore (das sind Gruppen wie CO, CN, NO), und daher sollten diese Materialien keine starke Photolumineszenz (PL) im herkömmlichen Sinne aufweisen. Allerdings kann die PL dieser Sub‐Fluorophore durch chemische Vernetzung oder physikalische Immobilisierung von Polymerketten verstärkt werden. Dieser Effekt wird als gesteigerte Emission durch Vernetzung (CEE) bezeichnet. Außerdem kann CEE über kovalente Bindungen, über Aggregation zu einer starren Struktur und über supramolekulare Wechselwirkungen bei NCPDs realisiert werden. Synthesestrategien, optische Eigenschaften und die Aussichten von NCPDs auf Gebieten wie biologische Bildgebung und Wirkstofftransport werden erörtert.
A Mini‐Twister Variant and Impact of Residues/Cations on the Phosphodiester Cleavage of this Ribozyme Class
Authors: Košutić Marija , Neuner Sandro , Ren Aiming , Flür Sara , Wunderlich Christoph , Mairhofer Elisabeth , Vušurović Nikola , Seikowski Jan , Breuker Kathrin , Höbartner Claudia , Patel Dinshaw J. , Kreutz Christoph , Micura Ronald 
Published: October 2015

AbstractNucleolytic ribozymes catalyze site‐specific cleavage of their phosphodiester backbones. A minimal version of the twister ribozyme is reported that lacks the phylogenetically conserved stem P1 while retaining wild‐type activity. Atomic mutagenesis revealed that nitrogen atoms N1 and N3 of the adenine‐6 at the cleavage site are indispensable for cleavage. By NMR spectroscopy, a pKa value of 5.1 was determined for a 13C2‐labeled adenine at this position in the twister ribozyme, which is significantly shifted compared to the pKa of the same adenine in the substrate alone. This finding pinpoints at a potential role for adenine‐6 in the catalytic mechanism besides the previously identified invariant guanine‐48 and a Mg2+ ion, both of which are directly coordinated to the non‐bridging oxygen atoms of the scissile phosphate; for the latter, additional evidence stems from the observation that Mn2+ or Cd2+ accelerated cleavage of phosphorothioate substrates. The relevance of this metal ion binding site is further emphasized by a new 2.6 Å X‐ray structure of a 2′‐OCH3‐U5 modified twister ribozyme.
Kristallstruktur einer pflanzlichen Tyrosinase aus Walnussblättern: die Bedeutung “substratlenkender Aminosäurereste” für die Enzymspezifität
Authors: Bijelic Aleksandar , Pretzler Matthias , Molitor Christian , Zekiri Florime , Rompel Annette 
Published: October 2015

AbstractTyrosinasen und Catecholoxidasen gehören zur Klasse der Typ‐III‐Kupferenzyme. Forscher arbeiten seit Jahrzehnten daran, die Monophenolase‐/Diphenolase‐Spezifität dieser Enzyme auf struktureller Ebene zu erklären und entwickelten dazu eine Hypothese (basierend auf der ersten Catechol‐ und Tyrosinasestruktur), der zufolge der Grund für das Fehlen von Monophenolase‐Aktivität in Catecholoxidasen das strukturell eingeschränkte aktive Zentrum sein könnte. Jüngste strukturelle und biochemische Studien an dieser Enzymklasse liefern jedoch Anlass zu Zweifeln an dieser Theorie. Hier wird die erste Kristallstruktur einer pflanzlichen Tyrosinase (Juglans regia) präsentiert, anhand derer gezeigt wird, dass die Unterscheidung zwischen Mono‐ und Diphenolase‐Aktivität auf struktureller Ebene nicht durch eine strukturelle Einschränkung des aktiven Zentrums bestimmt wird; vielmehr spielen Aminosäuren, die sich am Eingang zu und innerhalb der zweiten Schale um das aktive Zentrum befinden, eine viel wichtigere Rolle, als bisher angenommen.
Trapping N2 and CO2 on the Sub‐Nano Scale in the Confined Internal Spaces of Open‐Cage C60 Derivatives: Isolation and Structural Characterization of the Host–Guest Complexes
Authors: Futagoishi Tsukasa , Murata Michihisa , Wakamiya Atsushi , Murata Yasujiro 
Published: October 2015

AbstractAn open‐cage C60 tetraketone with a large opening was able to encapsulate N2 and CO2 molecules after its exposure to high pressures of N2 and CO2 gas. A subsequent selective reduction of one of the four carbonyl groups on the rim of the opening induced a contraction of the opening (→2) and trapped the guest molecules inside 2. The thus‐obtained host–guest complexes N2@2 and CO2@2 could be isolated by recycling HPLC, and were found to be stable at room temperature. The molecular structures of N2@2 and CO2@2 were determined by single‐crystal X‐ray diffraction analyses, and revealed a short NN triple bond for the encapsulated N2, as well as an unsymmetric molecular structure for the encapsulated molecule of CO2. The IR spectrum of CO2@2 suggested that the rotation of the encapsulated molecule of CO2 is partially restricted, which was supported by DFT calculations.
Detection of Circularly Polarized Luminescence of a Cs‐EuIII Complex in Raman Optical Activity Experiments
Authors: Wu Tao , Kapitán Josef , Mašek Vlastimil , Bouř Petr 
Published: October 2015

AbstractCircularly polarized luminescence (CPL) spectra are extremely sensitive to molecular structure. However, conventional CPL measurements are difficult and require expensive instrumentation. As an alternative, we explore CPL using Raman scattering and Raman optical activity (ROA) spectroscopy. The cesium tetrakis(3‐heptafluoro‐butylryl‐(+)‐camphorato) europium(III) complex was chosen as a model as it is known to exhibit very large CPL dissymmetry ratio. The fluorescent bands could be discriminated from true Raman signals by comparison of spectra acquired with different laser excitation wavelengths. Furthermore, the ROA technique enables fluorescence identification by measuring the degree of circularity. The CPL dissymmetry ratio was measured as the ROA circular intensity difference of 0.71, the largest one ever reported. The alternative CPL measurement enhances applications of lanthanides in analytical chemistry and chemical imaging of biological objects.
Synthesis and Functional Reconstitution of Light‐Harvesting Complex II into Polymeric Membrane Architectures
Authors: Zapf Thomas , Tan Cherng‐Wen Darren , Reinelt Tobias , Huber Christoph , Shaohua Ding , Geifman‐Shochat Susana , Paulsen Harald , Sinner Eva‐Kathrin 
Published: October 2015

AbstractOne of most important processes in nature is the harvesting and dissipation of solar energy with the help of light‐harvesting complex II (LHCII). This protein, along with its associated pigments, is the main solar‐energy collector in higher plants. We aimed to generate stable, highly controllable, and sustainable polymer‐based membrane systems containing LHCII–pigment complexes ready for light harvesting. LHCII was produced by cell‐free protein synthesis based on wheat‐germ extract, and the successful integration of LHCII and its pigments into different membrane architectures was monitored. The unidirectionality of LHCII insertion was investigated by protease digestion assays. Fluorescence measurements indicated chlorophyll integration in the presence of LHCII in spherical as well as planar bilayer architectures. Surface plasmon enhanced fluorescence spectroscopy (SPFS) was used to reveal energy transfer from chlorophyll b to chlorophyll a, which indicates native folding of the LHCII proteins.
A Visible‐Light‐Mediated Radical Smiles Rearrangement and its Application to the Synthesis of a Difluoro‐Substituted Spirocyclic ORL‐1 Antagonist
Authors: Douglas James J. , Albright Haley , Sevrin Martin J. , Cole Kevin P. , Stephenson Corey R. J. 
Published: October 2015

AbstractA visible‐light‐mediated radical Smiles rearrangement has been developed to address the challenging synthesis of the gem‐difluoro group present in an opioid receptor‐like 1 (ORL‐1) antagonist that is currently in development for the treatment of depression and/or obesity. This method enables the direct and efficient introduction of the difluoroethanol motif into a range of aryl and heteroaryl systems, representing a new disconnection for the synthesis of this versatile moiety. When applied to the target compound, the photochemical step could be conducted on 15 g scale using industrially relevant [Ru(bpy)3Cl2] catalyst loadings of 0.01 mol %. This transformation is part of an overall five‐step route to the antagonist that compares favorably to the current synthetic sequence and demonstrates, in this specific case, a clear strategic benefit of photocatalysis.
Combining a Nitrogenase Scaffold and a Synthetic Compound into an Artificial Enzyme
Authors: Tanifuji Kazuki , Lee Chi Chung , Ohki Yasuhiro , Tatsumi Kazuyuki , Hu Yilin , Ribbe Markus W. 
Published: October 2015

AbstractNitrogenase catalyzes substrate reduction at its cofactor center ([(Cit)MoFe7S9C]n−; designated M‐cluster). Here, we report the formation of an artificial, nitrogenase‐mimicking enzyme upon insertion of a synthetic model complex ([Fe6S9(SEt)2]4−; designated Fe6RHH) into the catalytic component of nitrogenase (designated NifDKapo). Two Fe6RHH clusters were inserted into NifDKapo, rendering the conformation of the resultant protein (designated NifDKFe) similar to the one upon insertion of native M‐clusters. NifDKFe can work together with the reductase component of nitrogenase to reduce C2H2 in an ATP‐dependent reaction. It can also act as an enzyme on its own in the presence of EuIIDTPA, displaying a strong activity in C2H2 reduction while demonstrating an ability to reduce CN− to C1–C3 hydrocarbons in an ATP‐independent manner. The successful outcome of this work provides the proof of concept and underlying principles for continued search of novel enzymatic activities based on this approach.
Synthetic Origin of Tramadol in the Environment
Authors: Kusari Souvik , Tatsimo Simplice Joel N. , Zühlke Sebastian , Spiteller Michael 
Published: October 2015

AbstractThe presence of tramadol in roots of Sarcocephalus latifolius trees in Northern Cameroon was recently attributed to point contamination with the synthetic compound. The synthetic origin of tramadol in the environment has now been unambiguously confirmed. Tramadol samples isolated from tramadol pills bought at a street market in downtown Maroua and highly contaminated soil at Houdouvou were analyzed by high‐precision 14C measurements by accelerator mass spectrometry (14C AMS): Tramadol from the pills did not contain any radiocarbon, thus indicating that it had been synthesized from 14C‐free petroleum‐derived precursors. Crucially, tramadol isolated from the soil was also radiocarbon‐free. As all biosynthetic plant compounds must contain radiocarbon levels close to that of the contemporary environment, these results thus confirm that tramadol isolated from the soil cannot be plant‐derived. Analyses of S. latifolius seeds, in vitro grown plants, plants from different origins, and stable‐isotope labeling experiments further confirmed that synthetic tramadol contaminates the environment.
Regulation of Transforming Growth Factor β–Activated Kinase Activation by Epigallocatechin‐3‐Gallate in Rheumatoid Arthritis Synovial Fibroblasts: Suppression of K63‐Linked Autoubiquitination of Tumor Necrosis Factor Receptor–Associated Factor 6
Authors: Singh Anil K. , Umar Sadiq , Riegsecker Sharayah , Chourasia Mukesh , Ahmed Salahuddin 
Published: October 2015

ObjectiveTransforming growth factor β–activated kinase 1 (TAK1) is a key MAPKKK family protein in interleukin‐1β (IL‐1β), tumor necrosis factor (TNF), and Toll‐like receptor signaling. This study was undertaken to examine the posttranslational modification of TAK1 and its therapeutic regulation in rheumatoid arthritis (RA).MethodsThe effect of TAK1, IL‐1 receptor–associated kinase 1 (IRAK‐1), and TNF receptor–associated factor 6 (TRAF6) inhibition was evaluated in IL‐1β–stimulated human RA synovial fibroblasts (RASFs). Western blotting, immunoprecipitation, and 20S proteasome assay were used to study the ubiquitination process in RASFs. The efficacy of epigallocatechin‐3‐gallate (EGCG), a potent antiinflammatory molecule, in regulating these processes in RASFs was evaluated. Molecular docking was performed to examine the interaction of EGCG with human TAK1, IRAK‐1, and TRAF6. These findings were confirmed using a rat model of adjuvant‐induced arthritis (AIA).ResultsInhibition of TAK1, but not IRAK‐1 or TRAF6, completely abrogated IL‐1β–induced IL‐6 and IL‐8 synthesis in RASFs. EGCG inhibited TAK1 phosphorylation at Thr184/187 and occupied the C174 position, an ATP‐binding site, to inhibit its kinase activity. EGCG pretreatment also inhibited K63‐linked autoubiquitination of TRAF6, a posttranslational modification essential for TAK1 autophosphorylation, by forming a stable H bond at the K124 position on TRAF6. Furthermore, EGCG enhanced proteasome‐associated deubiquitinase expression to rescue proteins from proteasomal degradation. Western blot analyses of joint homogenates from rats with AIA showed a significant increase in K48‐linked polyubiquitination, TAK1 phosphorylation, and TRAF6 expression when compared to naive rats. Administration of EGCG (50 mg/kg/day) for 10 days ameliorated AIA in rats by reducing TAK1 phosphorylation and K48‐linked polyubiquitination.ConclusionOur findings provide a rationale for targeting TAK1 for the treatment of RA with EGCG.
Dynamic Contrast‐Enhanced Magnetic Resonance Imaging Using Pharmacokinetic Modeling: Initial Experience in Patients With Early Arthritis
Authors: Maijer Karen I. , van der Leij Christiaan , de Hair Maria J. H. , Tas Sander W. , Maas Mario , Gerlag Daniëlle M. , Tak Paul P. , Lavini Cristina 
Published: October 2015

ObjectiveAnalysis of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) using pharmacokinetic modeling (PKM) provides quantitative measures that mirror microvessel integrity and can be used as an objective marker of the level of synovial inflammation. The aim of this study was to investigate the PKM parameters Ktrans, kep, and ve in a prospective cohort of disease‐modifying antirheumatic drug (DMARD)–naive patients with early arthritis, and to validate the results by assessing their correlation with the number of synovial endothelial cells (ECs).MethodsForty‐seven patients with early arthritis (arthritis duration <1 year, DMARD naive; comprising 14 patients with rheumatoid arthritis, 22 with unclassified arthritis, 6 with spondyloarthritis [SpA], and 5 with other arthritides) were included. At baseline, DCE‐MRI was performed on an inflamed knee joint of each patient. These images were used to calculate the Ktrans (volume transfer constant between the plasma and extracellular extravascular space [EES]), the kep (transfer constant between the EES and plasma), and the ve (fractional volume of the EES). Second, markers of disease activity were collected. Finally, vascularity was evaluated by immunohistochemical analysis of synovial tissue samples obtained from the inflamed knee joints, using antibodies to detect von Willebrand factor (vWF), a marker of ECs.ResultsThe 3 PKM parameters differed significantly between diagnostic groups at baseline, with the highest Ktrans value being observed in patients with SpA (median 0.050/minute, interquartile range [IQR] 0.041– 0.069). Furthermore, the Ktrans, kep, and ve values correlated significantly with markers of disease activity. Finally, the PKM parameters Ktrans and kep, but not ve, correlated significantly with synovial expression of vWF (r = 0.647, P = 0.004 for Ktrans; r = 0.614, P = 0.007 for kep; r = 0.398, P = 0.102 for ve).ConclusionThese results suggest that the Ktrans, kep, and ve can be used to detect synovial inflammation in patients with early arthritis, and these PKM parameters may be helpful in differential diagnosis. This approach may also be useful in translational research analyzing tissue microcirculation and angiogenesis.
The feasibility of short‐term production strategies for renewable jet fuels – a comprehensive techno‐economic comparison
Authors: de Jong Sierk , Hoefnagels Ric , Faaij André , Slade Raphael , Mawhood Rebecca , Junginger Martin 
Published: October 2015

AbstractThis study compares the short‐term economic feasibility of six conversion pathways for renewable jet fuel (RJF) production. The assessment combines (i) a harmonized techno‐economic analysis of conversion pathways expected to be certified for use in commercial aviation by 2020, (ii) a pioneer plant analysis taking into account technological immaturity, and (iii) a quantified assessment of the merits of co‐producing RJF alongside existing European supply chains in the pulp, wheat ethanol, and beet sugar industries. None of the pathways assessed are able to reach price parity with petroleum‐derived jet fuel in the short term. The pioneer plant analysis suggests that the hydroprocessed esters and fatty acids (HEFA) pathway is currently the best option; the technology achieves the lowest minimum fuel selling price (MFSP) of 29.3 € GJ−1 (1289 € t−1) and the technology is deployed on commercial scale already. In the short term, nth plant analysis shows hydrothermal liquefaction (HTL) and pyrolysis emerging as promising alternatives, yielding MFSPs of 21.4 € GJ−1 (939 € t−1) and 30.2 € GJ−1 (1326 € t−1), respectively. The pioneer plant analysis shows considerable MFSP increases for producing drop‐in fuels using HTL and pyrolysis as both technologies are relatively immature. Hence, further RD&D efforts into these pathways are recommended. Co‐production strategies decrease the MFSP by 4–8% compared to greenfield production. Integration of process units and material and energy flows is expected to lead to further cost reductions. As such, co‐production can be a particularly useful strategy to progress emerging technologies to commercial scale. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd