bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systematic survey of high‐resolutionbvalue imaging along Californian faults: Inference on asperities
Authors: Tormann T. , Wiemer S. , Mignan A. 
Published: February 2014

AbstractUnderstanding and forecasting earthquake occurrences is presumably linked to understanding the stress distribution in the Earth's crust. This cannot be measured instrumentally with useful coverage. However, the size distribution of earthquakes, quantified by the Gutenberg‐Richterbvalue, is possibly a proxy to differential stress conditions and could therewith act as a crude stress‐meter wherever seismicity is observed. In this study, we improve the methodology ofbvalue imaging for application to a high‐resolution 3‐D analysis of a complex fault network. In particular, we develop a distance‐dependent sampling algorithm and introduce a linearity measure to restrict our output to those regions where the magnitude distribution strictly follows a power law. We assess the catalog completeness along the fault traces using the Bayesian Magnitude of Completeness method and systematically imagebvalues for 243 major fault segments in California. We identify and reportbvalue structures, revisiting previously published features, e.g., the Parkfield asperity, and documenting additional anomalies, e.g., along the San Andreas and Northridge faults. Combining localbvalues with local earthquake productivity rates, we derive probability maps for the annual potential of one or moreM6 events as indicated by the microseismicity of the last three decades. We present a physical concept of how different stressing conditions along a fault surface may lead tobvalue variation and explain nonlinear frequency‐magnitude distributions. Detailed spatialbvalue information and its physical interpretation can advance our understanding of earthquake occurrence and ideally lead to improved forecasting ability.
Optical Microscopy Studies of Liquid Crystals
Authors: Cowling Stephen J. 
Published: February 2014

AbstractLiquid crystals, just like ordered crystals, organize themselves in structures that are relatively well defined, but this organization is not perfect and, as a result, they include defects. These defects, when viewed using polarized light microscopy, give rise to optical textures that are characteristic for each of the different liquid‐crystalline mesophases and provide a valuable diagnostic tool for the identification of mesophase type. This chapter focuses on the types of defects that occur and looks at the optical textures arising from the formation of defects in liquid crystal mesophases.
Nematic Liquid Crystals for Display Applications
Authors: Klasen‐Memmer Melanie , Hirschmann Harald 
Published: February 2014

AbstractStarting with the introduction ofTNdisplays for wrist watches and calculators in the 1970s,LCDtechnology is now the dominating technology for any kind of display application. This review summarizes the individual material requirements for passive, matrix‐drivenTNandSTNtechnologies, forTFT‐TN,IPS,FFS,OCBand projection technologies, and forVAandPS‐VAtechnologies. KeyLCmaterials and their structure–property relations, as well asLCmixture properties, are highlighted.
Chemical Structures, Mesogenic Properties, and Synthesis of Liquid Crystals with Bent‐Core Structures
Authors: Gimeno Nélida , Blanca Ros María 
Published: February 2014

AbstractBent‐core liquid crystals are currently an interdisciplinary research field that is properly established. For this achievement, chemists have focused their efforts on the design and synthesis of a wide variety of bent‐shaped compounds with fairly different chemical structures, either of low molecular weight or of diverse macromolecules.All these investigations have provided significant information on the chemical structure‐mesomorphic properties for this type of compound, revealing that, through subtle intermolecular interactions, a large variety of fascinating nematic, lamellar, and columnar liquid‐crystalline organizations can be induced, and even combined, with classical mesophases. As it is stressed throughout this chapter, this capability can be modulated and controlled by the appropriate selection and connection of the three basic structural units in bent‐shaped mesogens: the central bent‐core and the rodlike peripheral moiety, both forming the bent‐shaped basic structure of these molecules, and the terminal substituents or chains. The great versatility of design that offers these somewhat nonconventional mesogens might be exploited not only to investigate the basic structure‐activity relationships but also to achieve precise functional properties in the route to smart and functional materials.
Laterally Alkyl‐ and Aryl‐Substituted, Swallow‐Tailed, and Polycatenar Mesogens: Structural Features and Functionalities
Authors: Weissflog Wolfgang 
Published: February 2014

AbstractLong‐chain groups additionally attached to calamitic mesogens change the shape of the molecules and, therefore, their attractive and repulsive interactions. While compounds bearing lateral alkyl groups mostly exhibit nematic phases, lateral substitution with aryl‐containing groups means a qualitative jump by special packing in layer structures. Polycatenar mesogens can be wedge or dumbbell shaped depending on the number and positions of hydrocarbon chains at one or both terminal positions. Phasmidic and double‐swallow‐tailed mesogens are not able to exhibit smectic A phases for steric reasons, which can be induced, however, in mixtures with small rodlike molecules. Lateral alkyl chains attached to bent‐core mesogens reduce the tendency to form polar switchable layer phases, whereas polycatenar bent molecules form columnar structures. Equipping the molecules under discussion with functional groups in any ω‐standing position allows the lateral or terminal connection of mesogens, for example, to dendrimers, polymers, or metallic surfaces such as gold. In general, increasing the number of aliphatic chains often decreases melting points, increases solubility, and, therefore, allows better processability of functional materials.
Design and Synthesis of Side‐Chain Liquid Crystal Polymers
Authors: Ujiie Seiji , Kato Takashi 
Published: February 2014

AbstractVarious types of side‐chain liquid crystal polymers with ferroelectric, photoactive, thermochromic, hydrogen‐bonded, and ionized properties have been synthesized by many research groups, and their physicochemical properties and orientational behavior have been studied. These studies have established the relationship between the structure and the physicochemical properties. This chapter describes the design and synthesis of a conventional side‐chain liquid crystal polymer in which mesogenic side groups are attached to the polymer chains.
Crystal Structures of the Carborane Dianions [1,4‐(PhCB10H10C)2C6H4]2− and [1,4‐(PhCB10H10C)2C6F4]2− and the Stabilizing Role of the para‐Phenylene Unit on 2 n+3 Skeletal Electron Clusters
Authors: Kahlert Jan , Stammler Hans‐Georg , Neumann Beate , Harder Rachel A. , Weber Lothar , Fox Mark A. 
Published: February 2014

AbstractWhile carboranes with 2 n+2 and 2 n+4 (n=number of skeletal atoms) skeletal electrons (SE) are widely known, little has been reported on carboranes with odd SE numbers. Electrochemical measurements on two‐cage assemblies, where two C‐phenyl‐ortho‐carboranyl groups are linked by a para‐phenylene or a para‐tetrafluorophenylene bridge, revealed two well separated and reversible two‐electron reduction waves indicating formation of stable dianions and tetraanions. The salts of the dianions were isolated by reduction with sodium metal and their unusual structures were determined by X‐ray crystallography. The diamagnetic dianions contain two 2 n+3 SE clusters where each cluster has a notably long carborane C–carborane C distance of ca 2.4 Å. The π conjugation within the phenylene bridge plays an important role in the stabilization of these carboranes with odd SE counts.
In Situ Total X‐Ray Scattering Study of WO3 Nanoparticle Formation under Hydrothermal Conditions
Authors: Saha Dipankar , Jensen Kirsten M. Ø. , Tyrsted Christoffer , Bøjesen Espen D. , Mamakhel Aref Hasen , Dippel Ann‐Christin , Christensen Mogens , Iversen Bo B. 
Published: February 2014

AbstractPair distribution function analysis of in situ total scattering data recorded during formation of WO3 nanocrystals under hydrothermal conditions reveal that a complex precursor structure exists in solution. The WO6 polyhedra of the precursor cluster undergo reorientation before forming the nanocrystal. This reorientation is the critical element in the formation of different hexagonal polymporphs of WO3.
Direct Synthetic Route to Functionalized 1,2‐Azaborinines
Authors: Braunschweig Holger , Geetharani K. , Jimenez‐Halla J. Oscar C. , Schäfer Marius 
Published: February 2014

AbstractA new catalytic synthetic route to functionalized 1,2‐azaborinines has been developed by the [2+2]/[2+4] cycloaddition reactions of di‐tert‐butyliminoboranes and alkynes in presence of a rhodium catalyst. The first examples of ferrocene‐functionalized azaborinines have been synthesized using this strategy. Moreover, the regioselectivity of this reaction can be controlled by the formation of an intermediate rhodium 1,2‐azaborete complex, which results in the isolation of the first azaborinine boronic ester. The isolation of an NH‐containing BN isostere by elimination of isobutene from an N(tBu) group under thermolytic conditions has also been achieved. Theoretical studies give further insight into the formation of 1,2‐azaborinines and the elimination of isobutene from the N(tBu) group.
Luminescence properties of barium – gadolinium–titanate ceramics doped with rare‐earth ions (Eu3+ and Tb3+)
Authors: Hemasundara Raju S. , Muni Sudhakar B. , Sudhakar Reddy B. , Dhoble S. J. , Thyagarajan K. , Nageswara Raju C. 
Published: February 2014

ABSTRACTBarium‐gadolinium‐titanate (BaGd2Ti4O12) powder ceramics doped with rare‐earth ions (Eu3+ and Tb3+) were synthesized by a solid‐state reaction method. From the X‐ray diffraction spectrum, it was observed that Eu3+ and Tb3+:BaGd2Ti4O12 powder ceramics are crystallized in the form of an orthorhombic structure. Scanning electron microscopy image shows that the particles are agglomerated and the particle size is about 200 nm. Eu3+‐ and Tb3+‐doped BaGd2Ti4O12 powder ceramics were examined by energy dispersive X‐ray analysis, Fourier transform infrared spectroscopy, photoluminescence and thermoluminescence (TL) spectra. Emission spectra of Eu3+‐doped BaGd2Ti4O12 powder ceramics showed bright red emission at 613 nm (5D0 → 7F2) with an excitation wavelength λexci = 408 nm (7F0 → 5D3) and Tb3+:BaGd2Ti4O12 ceramic powder has shown green emission at 534 nm (5D4 → 7F5) with an excitation wavelength λexci = 331 nm ((7F6 → 5D1). TL spectra show that Eu3+ and Tb3+ ions affect TL sensitivity. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Stereochemistry of Avermectin‐Like 6,6‐Spiroketals on Biological Activities and Endogenous Biotransformations in Streptomyces avermectinius
Authors: Sun Peng , Zhao Qunfei , Zhang Hua , Wu Jiequn , Liu Wen 
Published: February 2014

AbstractNatural avermectins (AVEs) share a 6,6‐spiroketal moiety with an exclusive R configuration at the C21 spirocyclic junction. Herein, we report the characterization of nine AVE‐like spiroketals of two types (C21 S and R) in a mutant strain that lacks spirocyclase activity. Comparative analysis of their structures facilitated evaluation of the effect of stereochemistry on endogenous biotransformations and biological activities of the spiroketals.
Predictors for prolonged hospital stay after transcatheter mitral valve repair with the MitraClip®
Authors: Ledwoch Jakob , Bertog Stefan , Wunderlich Nina , Doss Mirko , Fichtlscherer Stephan , Teufel Tobias , Herholz Tina , Vaskelyte Laura , Hofmann Ilona , Sievert Horst 
Published: February 2014

ObjectiveThe aim is to find predictors for a prolonged LOHS after MitraClip® implantation.BackgroundDue to its less invasive nature, average length of hospital stay (LOHS) after the MitraClip® procedure is shorter compared to mitral valve surgery. However, some patients have a prolonged LOHS.MethodsRecords of consecutive patients who underwent MitraClip® procedure were reviewed. A total of 41 consecutive patients with MitraClip® implantation (76 ± 9 years, 59% men) were included. Median hospital stay was 7 days. Hospitalization lasting longer than 7 days was considered prolonged.ResultsProcedural success was achieved in 88% of the cases. In‐hospital death occurred in 4 of 41 patients (10%). Patients with a prolonged hospital stay (46%) had a higher EuroSCORE I (22.7% [IQR 10.3–28.3] vs. 6.7% [IQR 3.5–18.3], P = 0.017), a higher STS mortality score (6.1%[(IQR 3.7–7.5] vs. 2.6% [IQR 1.4–4.8]; P = 0.043) and a higher STS long‐length‐of‐stay score (18.9% [IQR 11.3–22.5] vs. 9.6% [IQR 6.2–16.1]; P = 0.039) as well as a lower estimated glomerular filtration rate (eGFR) (41 ml/min/1.73 m2 [IQR 19–52] vs. 56 ml/min/1.73 m2 [IQR 49–62]; P = 0.008) than those whose did not. In the multivariate model, lower eGFR was identified as predictor for a prolonged hospitalization.ConclusionLower pre‐procedure eGFR is independently associated with a longer hospitalization. © 2014 Wiley Periodicals, Inc.
Synthesis of Doubly Ethyl‐Bridged Bis(p‐sulfonatocalix[4]arene) and Its Supramolecular Polymerization with Viologen Dimer
Authors: Wang Kun‐Peng , Guo Dong‐Sheng , Zhao Hong‐Xia , Liu Yu 
Published: February 2014

AbstractA water‐soluble supramolecular polymer with a high degree of polymerization and viscosity has been constructed based on the strong host–guest interaction between p‐sulfonatocalix[4]arenes (SC4As) and viologen. A homoditopic doubly ethyl‐bridged bis(p‐sulfonatocalix[4]arene) (d‐SC4A) was prepared and its binding behavior towards methyl viologen compared with the singly ethyl‐bridged bis(p‐sulfonatocalix[4]arene) (s‐SC4A) by NMR spectroscopy and isothermal titration calorimetry. By employing a viologen dimer (bisMV4+) as the homoditopic guest, two linear AA/BB‐type supramolecular polymers, d‐SC4A⊃bisMV4+ and s‐SC4A⊃bisMV4+, were successfully constructed. Compared with s‐SC4A⊃bisMV4+, d‐SC4A⊃bisMV4+ shows much higher solubility and viscosity, and has also been characterized by viscosity, diffusion‐ordered NMR spectroscopy, dynamic light scattering, and atomic force microscopy measurements. Furthermore, the polymer is responsive to electrostimulus as viologen is electroactive, which was studied by cyclic voltammetry. This study represents a proof‐of‐principle as the polymer can potentially be applied as a self‐healing and degradable polymeric material.
A Membraneless Glucose/O2 Biofuel Cell Based on Pd Aerogels
Authors: Wen Dan , Liu Wei , Herrmann Anne‐Kristin , Eychmüller Alexander 
Published: February 2014

AbstractIn this study, we introduce the first membraneless glucose/O2 biofuel cell using Pd‐based aerogels as electrode materials. The bioanode was fabricated with a coimmobilized mediator and glucose oxidase for the oxidation of glucose, in which ferrocenecarboxylic acid was integrated into a three‐dimensional porous beta‐cyclodextrin‐modified Pd aerogel to mediate the bioelectrocatalytic reaction. Bilirubin oxidase and Pd–Pt alloy aerogel were confined to an electrode surface, which realized the direct bioelectrocatalytic function for the reduction of O2 to H2O with a synergetic effect at the biocathode. By employing these two bioelectrodes, the assembled glucose/O2 biofuel cell showed a maximum power output of 20 μW cm−2 at 0.25 V.
ortho‐Benzoxylation of N‐Alkyl Benzamides with Aromatic Acids Catalyzed by Ruthenium(II) Complex
Authors: Padala Kishor , Jeganmohan Masilamani 
Published: February 2014

AbstractA highly regioselective ortho‐benzoxylation of N‐alkyl benzamides with aromatic acids in the presence of [{RuCl2(p‐cymene)}2], AgSbF6, and (NH4)2S2O8 in 1,2‐dichloroethane at 100 °C for 24 h affording ortho‐benzoxylated N‐alkyl benzamides by CH bond activation is described. Further, Ru‐catalyzed alkenylation is done at the ortho CH bond of benzoxylated N‐alkyl benzamides with alkenes in water solvent. Subsequently, the benzoxyl moiety of N‐alkyl benzamides was converted into a hydroxyl group in the presence of base or acid. A possible reaction mechanism was proposed to account for the present coupling reaction.
Melt Phase Polymerization of Racemic Lactide to High‐Performance Poly(Lactic Acid)
Authors: Paetz Caspar , Hagen Rainer 
Published: February 2014

AbstractA process for the production of poly(lactic acid) with a melting point of > 150 °C from racemic lactide was developed. Only process steps that are usable in an industrial process were included to ensure an easy transfer to a commercial scale. A stereoselective catalyst system for lactide melt phase polymerization comprising of an Al‐salen initiator, a hydroxyl cocatalyst and an acidic quenching additive was developed. Monomer recovery aspects, temperature variation and different catalyst concentrations were evaluated to allow for a high yield process which can be transferred to a technical scale.
Production of Synthesis Gas from Biogas – Reactor Design and Integration into a Solid Oxide Fuel Cell System
Authors: Jahn Matthias , Reichelt Erik , Heddrich Marc , Weder Aniko 
Published: February 2014

AbstractEine Reformer‐Nachbrenner‐Einheit für den Einsatz in einem Festoxidbrennstoffzellensystem wird vorgestellt. Mittels des Verfahrens der oxidativen trockenen Reformierung kann aus Biogas ein Synthesegas mit einer hohen Energiedichte erzeugt werden. Der für den Reformierungsprozess benötigte Wärmestrom kann durch eine systeminterne Wärmenutzung bereitgestellt werden. Anschließend an einen Komponententest erfolgt die Integration in ein Festoxidbrennstoffzellensystem. Der im Rahmen einer thermodynamischen Analyse ermittelte, im Systembetrieb mögliche, elektrische Wirkungsgrad wird experimentell validiert.
Economic Assessment of the Hydrogenation of CO2 to Liquid Fuels and Petrochemical Feedstock
Authors: Smejkal Quido , Rodemerck Uwe , Wagner Edmund , Baerns Manfred 
Published: February 2014

AbstractTo remove high concentrations of CO2 from the off‐gas of coal‐driven power plants, a new process was proposed. The catalytic hydrogenation of the CO2 leads to the production of C2 – C4 (petrochemical feedstock) and liquid C5+ hydrocarbons (fuel). Thus, environmentally harmful CO2 may be converted sustainably to useful products. On the basis of a process flow sheet, the costs for processing the CO2 are estimated for different plant sizes. The price of hydrogen contributes significantly to the overall production costs. Further price reductions may be achieved by final engineering optimization of the process as a whole and specific unit operations.
Anti‐Dengue‐Virus Activity and Structure–Activity Relationship Studies of Lycorine Derivatives
Authors: Wang Peng , Li Lin‐Feng , Wang Qing‐Yin , Shang Lu‐Qing , Shi Pei‐Yong , Yin Zheng 
Published: February 2014

AbstractDengue is a systemic viral infection that is transmitted to humans by Aedes mosquitoes. No vaccines or specific therapeutics are currently available for dengue. Lycorine, which is a natural plant alkaloid, has been shown to possess antiviral activities against flaviviruses. In this study, a series of novel lycorine derivatives were synthesized and assayed for their inhibition of dengue virus (DENV) in cell cultures. Among the lycorine analogues, 1‐acetyllycorine exhibited the most potent anti‐DENV activity (EC50=0.4 μM) with a reduced cytotoxicity (CC50>300 μM), which resulted in a selectivity index (CC50/EC50) of more than 750. The ketones 1‐acetyl‐2‐oxolycorine (EC50=1.8 μM) and 2‐oxolycorine (EC50=0.5 μM) also exhibited excellent antiviral activities with low cytotoxicity. Structure–activity relationships for the lycorine derivatives against DENV are discussed. A three‐dimensional quantitative structure–activity relationship model was established by using a comparative molecular‐field analysis protocol in order to rationalize the experimental results. Further modifications of the hydroxy group at the C1 position with retention of a ketone at the C2 position could potentially lead to inhibitors with improved overall properties.
Developing an Irreversible Inhibitor of Human DDAH‐1, an Enzyme Upregulated in Melanoma
Authors: Wang Yun , Hu Shougang , Gabisi Abdul M. , Er Joyce A. V. , Pope Arthur , Burstein Gayle , Schardon Christopher L. , Cardounel Arturo J. , Ekmekcioglu Suhendan , Fast Walter 
Published: February 2014

AbstractInhibitors of the human enzyme dimethylarginine dimethylaminohydrolase‐1 (DDAH‐1) can raise endogenous levels of asymmetric dimethylarginine (ADMA) and lead to a subsequent inhibition of nitric oxide synthesis. In this study, N5‐(1‐imino‐2‐chloroethyl)‐L‐ornithine (Cl‐NIO) is shown to be a potent time‐ and concentration‐dependent inhibitor of purified human DDAH‐1 (KI=1.3±0.6 μM; kinact=0.34±0.07 min−1), with >500‐fold selectivity against two arginine‐handling enzymes in the same pathway. An activity probe is used to measure the “in cell” IC50 value (6.6±0.2 μM) for Cl‐NIO inhibition of DDAH‐1 artificially expressed within cultured HEK293T cells. A screen of diverse melanoma cell lines reveals that a striking 50/64 (78 %) of melanoma lines tested showed increased levels of DDAH‐1 relative to normal melanocyte control lines. Treatment of the melanoma A375 cell line with Cl‐NIO shows a subsequent decrease in cellular nitric oxide production. Cl‐NIO is a promising tool for the study of methylarginine‐mediated nitric oxide control and a potential therapeutic lead compound for other indications with elevated nitric oxide production, such as septic shock and idiopathic pulmonary fibrosis.
Proton Conductivity in Doped Aluminum Phosphonate Sponges
Authors: Wegener Jennifer , Kaltbeitzel Anke , Graf Robert , Klapper Markus , Müllen Klaus 
Published: February 2014

AbstractProton‐conducting networks (NETs) were prepared successfully by the insertion of phosphonated nanochannels into organic–inorganic hybrid materials that contain Al3+ as the connector and hexakis(p‐phosphonatophenyl)benzene (HPB) as the linker. Noncomplexed phosphonic acid groups remain in the framework, which depends on the ratio of both compounds, to yield a proton conductivity in the region of 10−3 S cm−1. This conductivity can be further improved and values as high as Nafion, a benchmark proton‐exchange membrane for fuel cell applications, can be obtained by filling the network pores with intrinsic proton conductors. As a result of their sponge‐like morphology, aluminum phosphonates adsorb conductive small molecules such as phosphonic acids, which results in a very high proton conductivity of approximately 5×10−2 S cm−1 at 120 °C and 50 % relative humidity (RH). Contrary to Nafion, the doped networks show a remarkably low temperature dependence of proton conductivity from external humidification. This effect indicates a transport mechanism that is different to the water vehicle mechanism. Furthermore, the materials exhibit an activation energy of 40 kJ mol−1 at 15 % RH that starts to diminish to 10 kJ mol−1 at 80 % RH, which is even smaller than the corresponding values obtained for Nafion 117.