bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precise relative earthquake depth determination using array processing techniques
Authors: Florez M. A. , Prieto G. A. 
Published: May 2017

AbstractPrecise determination of hypocentral depth remains one of the most relevant problems in earthquake seismology. It is well known that using depth phases allows for significant improvement in event depth determination; however, routinely and systematically picking such phases, for teleseismic or regional arrivals, is problematic due to poor signal‐to‐noise ratios around the pP and sP phases. To overcome this limitation, we have taken advantage of the additional information carried by seismic arrays. We use velocity spectral analysis to precisely measure pP‐P times. The individual estimates obtained at different subarrays, for all pairs of earthquakes, are combined using a double‐difference algorithm, in order to precisely map seismicity in regions where it is tightly clustered. We illustrate this method by relocating intermediate‐depth earthquakes in the Nazca subducting plate, beneath northern Chile, where we confirm the existence of a narrowly spaced double seismic zone, previously imaged using a local dedicated deployment. As a second example we relocate the aftershock sequence of the 2014 Mw 7.9 intermediate depth, Rat Islands earthquake, and provide evidence of a subvertical fault plane for the main shock. Finally, we show that the resulting relative depth errors are typically smaller than 2 km.
Deformation style and controlling geodynamic processes at the eastern Guadalquivir foreland basin (Southern Spain)
Authors: Marín‐Lechado C. , Pedrera A. , Peláez J. A. , Ruiz‐Constán A. , González‐Ramón A. , Henares J. 
Published: May 2017

AbstractThe tectonic structure of the Guadalquivir foreland basin becomes complex eastward evolving from a single depocenter to a compartmented basin. The deformation pattern within the eastern Guadalquivir foreland basin has been characterized by combining seismic reflection profiles, boreholes, and structural field data to output a 3‐D model. High‐dipping NNE‐SSW to NE‐SW trending normal and reverse fault arrays deform the Variscan basement of the basin. These faults generally affect Tortonian sediments, which show syntectonic features sealed by the latest Miocene units. Curved and S‐shaped fault traces are abundant and caused by the linkage of nearby fault segments during lateral fault propagation. Preexisting faults were reactivated either as normal or reverse faults depending on their position within the foreland. At Tortonian time, reverse faults deformed the basin forebulge, while normal faults predominated within the backbulge. Along‐strike variation of the Betic foreland basin geometry is supported by an increasing mechanical coupling of the two plates (Alborán Domain and Variscan basement) toward the eastern part of the cordillera. Thus, subduction would have progressed in the western Betics, while it would have failed in the eastern one. There, the initially subducted Iberian paleomargin (Nevado‐Filábride Complex) was incorporated into the upper plate promoting the transmission of collision‐related compressional stresses into the foreland since the middle Miocene. Nowadays, compression is still active and produces low‐magnitude earthquakes likely linked to NNE‐SSW to NE‐SW preexiting faults reactivated with reverse oblique‐slip kinematics. Seismicity is mostly concentrated around fault tips that are frequently curved in overstepping zones.
Kinetically Controlled Layer‐by‐Layer Stacking of Metal Oxide 2D Nanosheets
Authors: Lim Joohyun , Jin Xiaoyan , Jo Yun Kyung , Lee Seul , Hwang Seong‐Ju 
Published: May 2017

AbstractAn efficient chemical way to finely control the layer‐by‐layer stacking of inorganic nanosheets (NS) is developed by tuning the type and composition of intercalant ion, and the reaction temperature for restacking process. The finely controlled stacking of NS relies on a kinetic control of the self‐assembly of NS in the presence of coordinating organic cations. A critical role of organic cations in this assembly highlights the importance of the appropriate activation energy. Of prime importance is that a fine‐control of the interstratification of 2D NS is highly effective not only in tailoring its pore structure but also in enhancing its electrode activity. The present study clearly demonstrates that the kinetically controlled restacking of NS provides a facile and powerful method to tailor their stacking number and functionality.
Identifikation sekundärer Bindestellen auf DC‐SIGN mithilfe eines Fragment‐Screenings
Authors: Aretz Jonas , Baukmann Hannes , Shanina Elena , Hanske Jonas , Wawrzinek Robert , Zapol'skii Viktor A. , Seeberger Peter H. , Kaufmann Dieter E. , Rademacher Christoph 
Published: May 2017

AbstractDer Oberflächenrezeptor DC‐SIGN ermöglicht die Aufnahme von Krankheitserregern wie HIV, Ebolavirus oder Mycobacterium tuberculosis. Daher gab es zahlreiche Versuche, Inhibitoren gegen die Bindung dieses Rezeptors an Kohlenhydratstrukturen dieser Pathogene zu entwickeln. Wegen der hydrophilen und wenig markanten Glykan‐Bindestelle kennt man nur wenige Wirkstoff‐ähnliche Liganden für DC‐SIGN. Parallele Fragment‐Screenings mit SPR‐Spektroskopie und einem Reporter Displacement Assay ergänzen vorherige Screenings mit 19F‐NMR‐Spektroskopie und chemischen Mikroarrays. Die Validierung aktiver Substanzen mit SPR‐ und 1H‐15N‐HSQC‐NMR‐Spektroskopie zeigte, dass kein Fragment in die primäre Kohlenhydrattasche bindet, dafür jedoch fünf sekundäre Bindestellen vorhanden sind, die mit Wirkstoff‐ähnlichen Molekülen interagieren können. Mithilfe der Schlüsselinteraktionen der hier gezeigten Fragmente können diese Regionen gezielt erkundet und zukünftige Ansätze zur Entwicklung von DC‐SIGN‐Inhibitoren beschleunigt werden.
An Aggregating Amphiphilic Squaraine: A Light‐up Probe That Discriminates Parallel G‐Quadruplexes
Authors: Grande Vincenzo , Doria Filippo , Freccero Mauro , Würthner Frank 
Published: May 2017

AbstractG‐quadruplexes (G4s) are peculiar DNA or RNA tertiary structures that are involved in the regulation of many biological events within mammalian cells, bacteria, and viruses. Although their role as versatile therapeutic targets has been emphasized for 35 years, G4 selectivity over ubiquitous double‐stranded DNA/RNA, as well as G4 differentiation by small molecules, still remains challenging. Here, a new amphiphilic dicyanovinyl‐substituted squaraine, SQgl, is reported to act as an NIR fluorescent light‐up probe discriminating an extensive panel of parallel G4s while it is non‐fluorescent in the aggregated state. The squaraine can form an unconventional sandwich π‐complex binding two quadruplexes, which leads to a strongly fluorescent (ΦF=0.61) supramolecular architecture. SQgl is highly selective against non‐quadruplex and non‐parallel G4 sequences without altering their topology, as desired for applications in selective in vivo high‐resolution imaging and theranostics.
Aufklärung der Rolle von CeO2‐Nanopartikel‐Auflösung bei der Aufnahme in die Pflanze mithilfe intelligenter Radiomarkierung
Authors: Schymura Stefan , Fricke Thomas , Hildebrand Heike , Franke Karsten 
Published: May 2017

AbstractDie Identifizierung der Hauptaufnahmepfade von technischen Nanopartikeln in Pflanzen ist ein wichtiger Faktor bei der Einschätzung ihres Verbleibs in der Umwelt und der damit verbundenen Risiken. Durch den Einsatz unterschiedlicher Radiomarkierungsmethoden gelang es, eine hauptsächlich partikulär stattfindende Aufnahme von CeO2‐Nanopartikeln zu zeigen, im Unterschied zu einer Aufnahme in Form von ionischem Cer.
Enzymatic Engineering of Live Bacterial Cell Surfaces Using Butelase 1
Authors: Bi Xiaobao , Yin Juan , Nguyen Giang K. T. , Rao Chang , Halim Nurashikin Bte Abdul , Hemu Xinya , Tam James P. , Liu Chuan‐Fa 
Published: May 2017

AbstractButelase‐mediated ligation (BML) can be used to modify live bacterial cell surfaces with diverse cargo molecules. Surface‐displayed butelase recognition motif NHV was first introduced at the C‐terminal end of the anchoring protein OmpA on E. coli cells. This then served as a handle of BML for the functionalization of E. coli cell surfaces with fluorescein and biotin tags, a tumor‐associated monoglycosylated peptide, and mCherry protein. The cell‐surface ligation reaction was achieved at low concentrations of butelase and the labeling substrates. Furthermore, the fluorescein‐labeled bacterial cells were used to show the interactions with cultured HeLa cells and with macrophages in live transgenic zebrafish, capturing the latter's powerful phagocytic effect in action. Together these results highlight the usefulness of butelase 1 in live bacterial cell surface engineering for novel applications.
The Interstitial Carbon of the Nitrogenase FeMo Cofactor is Far Better Stabilized than Previously Assumed
Authors: Grunenberg Jörg 
Published: May 2017

AbstractThe first quantum‐mechanical calculations of all relevant potential constants in both the iron‐molybdenum cofactor and the iron‐vanadium cofactor of nitrogenase suggest that the carbide is bound to the center of the enzyme much more strongly than hitherto assumed. Previous studies seemed to indicate a dummy function of the interstitial carbon, with a weak force constant (ca. 0.32 N cm−1). Our new investigations confirm a different picture: the central carbon atom binds the iron‐sulfur cluster through six covalent C−Fe bonds. With a potential constant of more than 1.3 N cm−1, the interstitial carbon also appears to be dynamically persistent. According to our investigations, the values for the elasticity within the iron‐sulfur cluster have to be corrected too. These new details on the mechano‐chemical properties of the FeMo cofactor will be important for elucidating the catalytic cycle of nitrogen fixation. By implementing our new algorithm in the freely available COMPLIANCE program, the dependence on the coordinates during the calculation of Hesse matrices is eliminated completely.
An Unsaturated Quinolone N‐Oxide of Pseudomonas aeruginosa Modulates Growth and Virulence of Staphylococcus aureus
Authors: Szamosvári Dávid , Böttcher Thomas 
Published: May 2017

AbstractThe pathogen Pseudomonas aeruginosa produces over 50 different quinolones, 16 of which belong to the class of 2‐alkyl‐4‐quinolone N‐oxides (AQNOs) with various chain lengths and degrees of saturation. We present the first synthesis of a previously proposed unsaturated compound that is confirmed to be present in culture extracts of P. aeruginosa, and its structure is shown to be trans‐Δ1‐2‐(non‐1‐enyl)‐4‐quinolone N‐oxide. This compound is the most active agent against S.  aureus, including MRSA strains, by more than one order of magnitude whereas its cis isomer is inactive. At lower concentrations, the compound induces small‐colony variants of S. aureus, reduces the virulence by inhibiting hemolysis, and inhibits nitrate reductase activity under anaerobic conditions. These studies suggest that this unsaturated AQNO is one of the major agents that are used by P. aeruginosa to modulate competing bacterial species.
Rheological study on the thermoinduced gelation behavior of poly(N‐isopropylacrylamide‐co‐acrylic acid) microgel suspensions
Authors: Wang Tao , Jin Liang , Song Yanan , Li Jiaxi , Gao Yu , Shi Shan 
Published: May 2017

ABSTRACTSubmicron‐sized thermoresponsive poly(N‐isopropylacrylamide‐co‐acrylic acid) microgels were synthesized by soap‐free emulsion polymerization. The physical state of the microgel suspensions, in a wide range of polymer concentrations (1.1–7.1 wt %), transformed from fluid to gel when the temperature was elevated across their volume phase transition temperature at pH = 3.0. Such thermoinduced gelation behavior was studied in detail by small‐deformation oscillatory rheological measurements within the linear viscoelastic region. It was found that the gelation temperature was strongly affected by the polymer concentration, decreasing as the polymer concentration increased. The gelation kinetics showed that the suspension gelled more quickly at either larger polymer concentration or higher isothermal heating temperature. In an isothermal frequency sweep for the as‐formed gels, both storage and loss moduli,G′andG″, exhibited a power‐law behavior, that is,G′(ω) ∼ ω0.2–0.4andG″(ω) ∼ ω0.46−0.50within the frequency range whereG′dominatesG″. In addition, the elasticity of the gels, which results from the attractive particle bonds, increased markedly with increasing polymer concentration. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 45259.
Projection in snowfall characteristics over the European Alps and its sensitivity to the SST changes: results from a 50 km resolution AGCM
Authors: Freychet N. , Hsu H.‐H. , Duchez A. , Tu C.‐Y. 
Published: May 2017

AbstractThe end‐of‐century projection of the snowfall characteristics over the Alps region is studied using the 50‐km resolution atmospheric global climate model, HiRAM (high‐resolution atmospheric model). The model is forced by three different patterns of projections in the sea surface temperature (SST) in order to assess the sensitivity of snowfall characteristics to theses patterns. It is found that the mean snowfall intensity and frequency is poorly affected by the differences in SST forcing. However, the projections of heavy snowfall events strongly depend on the SST scenario. The changes in temperature and frequency of precipitation and freezing days over the Alps were investigated. We found that these variables did not exhibit a clear dependence to the SST scenario and could not explain the differences observed in snowfall projections. Changes in the moisture transport from the Atlantic Ocean to Europe were found significantly different between each scenario and are assumed to be the main factor affecting the projections of snowfalls, by providing more or less moisture supply.
Anomalous variation in summer tropical cyclone activity by preceding winter Aleutian low oscillation
Authors: Choi Jae‐Won , Cha Yumi 
Published: May 2017

AbstractThis research found a high‐positive correlation between Aleutian low oscillation during the winter (November–March) and tropical cyclone (TC) genesis frequency during the following summer (July–September) over a 26‐year period (1982–2007). In the years with high Aleutian low oscillation, a number of characteristics were analyzed. In the preceding winter, anomalous pressure patterns, such as south‐low and north‐high at the low level, formed as the center for the regions near 20°N in the western North Pacific. Sea ice concentration was less than the average around the Sea of Okhotsk and the Bering Sea, which weakened the Aleutian Low in this area. This anomalous pressure pattern continued until the following summer, and it reinforced the anomalous easterlies at the mid‐latitudes (20°–40°N) in East Asia and contributed to the high TC passage frequency in the East Asian continent.
Inhibitory Activity of Halogenated 3‐Benzylidenechroman‐4‐ones Against Lipopolysaccharide‐stimulated Reactive Oxygen Species Production in RAW 264.7 Macrophages
Authors: Thapa Magar Til Bahadur , Kadayat Tara Man , Oh Hye Jin , Park Pil‐Hoon , Lee Eung‐Seok 
Published: May 2017

Chromanone‐containing compounds have been reported to possess several important biological activities. As a part of our continuing effort for discovering potent anti‐inflammatory agents, a series of halogen‐containing 3‐benzylidenechroman‐4‐ones (1–15) were synthesized, and evaluated for their inhibitory effect on lipopolysaccharide (LPS)‐stimulated reactive oxygen species (ROS) production in RAW 264.7 macrophages. Compounds 4 and 10 exhibited significant inhibitory activity (IC50
= 5.09 ± 1.27 and 5.11 ± 0.51 μM, respectively) against LPS‐stimulated ROS production in RAW 264.7 macrophages.
Fabrication of g‐C3N4/Au/C‐TiO2 Hollow Structures as Visible‐Light‐Driven Z‐Scheme Photocatalysts with Enhanced Photocatalytic H2 Evolution
Authors: Zou Yajun , Shi Jian‐Wen , Ma Dandan , Fan Zhaoyang , Niu Chunming , Wang Lianzhou 
Published: May 2017

AbstractThe Z‐scheme photocatalytic system for water splitting based on semiconductors has exhibited great potential for H2 fuel production from renewable resources. In this work, we constructed g‐C3N4/Au/C‐TiO2 hollow spheres as an all‐solid‐state Z‐scheme photocatalytic system with Au nanoparticles as the electron mediator. The as‐synthesized g‐C3N4/Au/C‐TiO2 photocatalyst showed a remarkably enhanced photocatalytic H2 evolution rate under visible‐light irradiation (λ>420 nm), which was 86 and 42 times higher than those of pure C‐TiO2 and g‐C3N4, respectively. The enhancement of photocatalytic performance can be mainly attributed to the intentionally designed Z‐scheme system, which not only promoted the efficient transfer and separation of photogenerated electron–hole pairs, but also retained the strong redox ability of the charge carriers. In addition, the Z‐scheme system also achieved high visible‐light absorption and utilization owing to the surface plasmon resonance (SPR) effect of Au nanoparticles and hollow structures of C‐TiO2. All the factors synergistically promote the photocatalytic activity of the g‐C3N4/Au/C‐TiO2 hollow nanospheres, providing a promising method for the rational design of highly efficient visible‐light‐driven photocatalysts.
Theoretical Investigation into Suitable Pore Sizes of Membranes for Vanadium Redox Flow Batteries
Authors: Liu Zaichun , Li Ruilian , Chen Jizhong , Wu Xiongwei , Zhang Kai , Mo Jun , Yuan Xinhai , Jiang Hongmei , Holze Rudolf , Wu Yuping 
Published: May 2017

AbstractFor the first time, a three‐dimensional (3D) volume calculation model based on total electrostatic potential analysis and density functional calculations is applied to study the volume differences between hydrated multivalent vanadium ions (V2+, V3+, VO2+, and
) and charge‐balancing ions (H3O+,
and
) encountered in the electrolyte solutions of vanadium redox flow batteries (VRBs). The calculated results indicate that radii of all charge‐balancing ions are less than 3.01 Å and of all hydrated multivalent vanadium ions are greater than 3.78 Å. The results of our calculations also suggest that cation‐exchange membranes with pore sizes ranging from 3.98 to 7.56 Å and anion‐exchange membranes with pore sizes ranging from 6.02 to 7.56 Å are suitable for the VRB application. These computational results agree very well with reported experimental results and provide valuable guidance for the selection and design of membranes on the molecular level for VRB applications.
Fundamental Characteristics of a Glucose Transistor with a Chemically Functional Interface
Authors: Uematsu Yuta , Kajisa Taira , Sakata Toshiya 
Published: May 2017

AbstractSemiconductor‐based biosensors are suitable for the detection of small molecules such as glucose as long as they have molecular charges. However, biological samples include various ionic molecules such as proteins; thus, their nonspecific adsorption should be prevented to reduce background noise. In this study, we optimized a field‐effect transistor (FET)‐based glucose sensor, that is, a glucose transistor, for more precise and highly sensitive glucose sensing. Using the glucose transistor modified with 4‐mercaptophenylboronic acid (PBA) on a gold gate electrode, we found that the detection sensitivity to glucose was increased to approximately 60 mV/decade from about 40 μM. This means that the PBA on the gate induced a diol‐binding site with glucose through an equilibrium reaction, resulting in an increase in the density of negative charges in the PBA‐glucose conjugate. Moreover, an oligoethyleneglycol (OEG) monolayer was coated on the gate as a molecular sieve interface so that the PBA molecules were embowered in the OEG membrane, but low‐molecular‐weight glucose could pass between the OEG molecules and reach the PBA molecules at the gate. The detection sensitivity of the biosensor with the optimized glucose transistor to glucose remained, to some extent, even in a solution including albumin. Thus, a platform based on the optimized glucose transistor is available for the practical use of a novel sensor that can detect glucose even at the low concentrations included in biological fluids.
Feasibility of N2 Binding and Reduction to Ammonia on Fe‐Deposited MoS2 2D Sheets: A DFT Study
Authors: Azofra Luis Miguel , Sun Chenghua , Cavallo Luigi , MacFarlane Douglas R. 
Published: May 2017

AbstractBased on the structure of the nitrogenase FeMo cofactor (FeMoco), it is reported that Fe deposited on MoS2 2D sheets exhibits high selectivity towards the spontaneous fixation of N2 against chemisorption of CO2 and H2O. DFT predictions also indicate the ability of this material to convert N2 into NH3 with a maximum energy input of 1.02 eV as an activation barrier for the first proton–electron pair transfer.
Metal Confinement through N‐(9‐Alkyl)fluorenyl‐Substituted N‐Heterocyclic Carbenes and Its Consequences in Gold‐Catalysed Reactions Involving Enynes
Authors: Teci Matthieu , Hueber Damien , Pale Patrick , Toupet Loïc , Blanc Aurélien , Brenner Eric , Matt Dominique 
Published: May 2017

AbstractA series of gold(I) and gold(III) complexes containing bulky bis‐N,N′‐(9‐alkylfluorenyl) heterocyclic carbene (RF‐NHC) ligands have been prepared in high yields from appropriate imidazolinium, imidazolium and benzimidazolium salts. In all complexes, the carbene ligand provides high steric protection of the Au−X bond trans to the carbenic C atom. Irrespective of the metal oxidation state, the complexes showed high efficiency in a tandem 3,3‐rearrangement/Nazarov reaction of an enynyl acetate. One of the AuIII complexes, [AuCl3(RF‐NHC)], was further found to be suitable for the efficient cyclisation of a propargylcarboxamide. Furthermore, unlike related NHC–gold(I) complexes based on conventional bulky N‐heterocyclic carbenes (notably, 1,3‐bis‐(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr), 1,3‐bis‐(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene (IMes) and 1,3‐(bis‐tert‐butyl)imidazol‐2‐ylidene (ItBu)), the studied [AuICl(RF‐NHC)] complexes catalysed the conversion of a 1,6‐enyne in the presence of indole into a single product; this arises from the embracing character of the ligand, which prevents indole addition on one of the catalytic intermediates. A structure/selectivity relationship was established for all carbenes tested that took into account percent buried volumes and topographic steric maps. The results illustrate the high potential of confining NHCs in organic synthesis.
Synthesis and Antineoplastic Evaluation of Mitochondrial Complex II (Succinate Dehydrogenase) Inhibitors Derived from Atpenin A5
Authors: Wang Hezhen , Huwaimel Bader , Verma Kshitij , Miller James , Germain Todd M. , Kinarivala Nihar , Pappas Dimitri , Brookes Paul S. , Trippier Paul C. 
Published: May 2017

AbstractMitochondrial complex II (CII) is an emerging target for numerous human diseases. Sixteen analogues of the CII inhibitor natural product atpenin A5 were prepared to evaluate the structure–activity relationship of the C5 pyridine side chain. The side chain ketone moiety was determined to be pharmacophoric, engendering a bioactive conformation. One analogue, 1‐(2,4‐dihydroxy‐5,6‐dimethoxypyridin‐3‐yl)hexan‐1‐one (16 c), was found to have a CII IC50 value of 64 nm, to retain selectivity for CII over mitochondrial complex I (>156‐fold), and to possess a ligand‐lipophilicity efficiency (LLE) of 5.62, desirable metrics for a lead compound. This derivative and other highly potent CII inhibitors show potent and selective anti‐proliferative activity in multiple human prostate cancer cell lines under both normoxia and hypoxia, acting to inhibit mitochondrial electron transport.