bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Profiling Using Two‐Dimensional Difference Gel Electrophoresis (2‐D DIGE)
Authors: Feret Renata , Lilley Kathryn S.
Published: February 2014

2‐D DIGE relies on pre‐electrophoretic labeling of samples with one of three spectrally distinct fluorescent dyes, followed by electrophoresis of all samples in one 2‐D gel. The dye‐labeled samples are then viewed individually by scanning the gel at different wavelengths, which circumvents problems with gel‐to‐gel variation and spot matching between gels. Image analysis programs are used to generate volume ratios for each spot, which essentially describe the intensity of a particular spot in each test sample, and thus enable protein abundance level changes to be identified and quantified. This unit describes the 2‐D DIGE procedure including sample preparation from various cell types, labeling of proteins, and points to consider in the downstream processing of fluorescently labeled samples. Curr. Protoc. Protein Sci. 75:22.2.1‐22.2.17. © 2014 by John Wiley & Sons, Inc.
Global assessment of ocean carbon export by combining satellite observations and food‐web models
Authors: Siegel D. A. , Buesseler K. O. , Doney S. C. , Sailley S. F. , Behrenfeld M. J. , Boyd P. W.
Published: February 2014

The export of organic carbon from the surface ocean by sinking particles is an important, yet highly uncertain, component of the global carbon cycle. Here we introduce a mechanistic assessment of the global ocean carbon export using satellite observations, including determinations of net primary production and the slope of the particle size spectrum, to drive a food‐web model that estimates the production of sinking zooplankton feces and algal aggregates comprising the sinking particle flux at the base of the euphotic zone. The synthesis of observations and models reveals fundamentally different and ecologically consistent regional‐scale patterns in export and export efficiency not found in previous global carbon export assessments. The model reproduces regional‐scale particle export field observations and predicts a climatological mean global carbon export from the euphotic zone of ~6 Pg C yr−1. Global export estimates show small variation (typically < 10%) to factor of 2 changes in model parameter values. The model is also robust to the choices of the satellite data products used and enables interannual changes to be quantified. The present synthesis of observations and models provides a path for quantifying the ocean's biological pump.
Geophysical signatures of past and present hydration within a young oceanic core complex
Authors: Blackman Donna K. , Slagle Angela , Guerin Gilles , Harding Alistair
Published: February 2014

Borehole logging at the Atlantis Massif oceanic core complex provides new information on the relationship between the physical properties and the lithospheric hydration of a slow‐spread intrusive crustal section. Integrated Ocean Drilling Program Hole U1309D penetrates 1.4 km into the footwall to an exposed detachment fault on the 1.2 Ma flank of the mid‐Atlantic Ridge, 30°N. Downhole variations in seismic velocity and resistivity show a strong correspondence to the degree of alteration, a recorder of past seawater circulation. Average velocity and resistivity are lower, and alteration is more pervasive above a fault around 750 m. Deeper, these properties have higher values except in heavily altered ultramafic zones that are several tens of meters thick. Present circulation inferred from temperature mimics this pattern: advective cooling persists above 750 m, but below, conductive cooling dominates except for small excursions within the ultramafic zones. These alteration‐related physical property signatures are probably a characteristic of gabbroic cores at oceanic core complexes.
Studies of the Room‐Temperature Multiferroic Pb(Fe0.5Ta0.5)0.4(Zr0.53Ti0.47)0.6O3: Resonant Ultrasound Spectroscopy, Dielectric, and Magnetic Phenomena
Authors: Schiemer J. , Carpenter M. A. , Evans D. M. , Gregg J. M. , Schilling A. , Arredondo M. , Alexe M. , Sanchez D. , Ortega N. , Katiyar R. S. , Echizen M. , Colliver E. , Dutton S. , Scott J. F.
Published: February 2014

Recently, lead iron tantalate/lead zirconium titanate (PZTFT) was demonstrated to possess large, but unreliable, magnetoelectric coupling at room temperature. Such large coupling would be desirable for device applications but reproducibility would also be critical. To better understand the coupling, the properties of all 3 ferroic order parameters, elastic, electric, and magnetic, believed to be present in the material across a range of temperatures, are investigated. In high temperature elastic data, an anomaly is observed at the orthorhombic mm2 to tetragonal 4mm transition, Tot = 475 K, and a softening trend is observed as the temperature is increased toward 1300 K, where the material is known to become cubic. Thermal degradation makes it impossible to measure elastic behavior up to this temperature, however. In the low temperature region, there are elastic anomalies near ≈40 K and in the range 160–245 K. The former is interpreted as being due to a magnetic ordering transition and the latter is interpreted as a hysteretic regime of mixed rhombohedral and orthorhombic structures. Electrical and magnetic data collected below room temperature show anomalies at remarkably similar temperature ranges to the elastic data. These observations are used to suggest that the three order parameters in PZTFT are strongly coupled.
Amine‐Tunable Ruthenium Catalysts for Asymmetric Reduction of Ketones
Authors: Rodríguez Sonia , Qu Bo , Fandrick Keith R. , Buono Frederic , Haddad Nizar , Xu Yibo , Herbage Melissa A. , Zeng Xingzhong , Ma Shengli , Grinberg Nelu , Lee Heewon , Han Zhengxu S. , Yee Nathan K. , Senanayake Chris H.
Published: February 2014

A series of efficient ruthenium catalysts has been developed for the asymmetric hydrogenation and transfer hydrogenation of ketones with high reactivities and selectivities. The new chiral bisdihydrobenzooxaphosphole (BIBOP)/diamine‐ruthenium complexes catalyzed the enantioselective hydrogenation of substrates such as aryl and heteroaryl cyclic and alkyl ketones with substrate/catalyst (S/C) ratios of up to 100,000. The opposite sense of enantioselectivity can be obtained by proper selection of a diamine with a given chirality of the phosphine. The usefulness of the new system has been demonstrated in the asymmetric hydrogenation of a complex synthetic intermediate towards cholesteryl ester transfer protein (CETP) inhibitors at S/C 20,000 on large‐scale operation.

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Synthesis of 4‐Aminoxanthones by an Uncatalyzed, Multicomponent Reaction
Authors: Bornadiego Ana , Díaz Jesús , Marcos Carlos F.
Published: February 2014

The synthesis of xanthones via a multicomponent reaction of isocyanides is described for the first time. In this one‐pot process, a tandem [4+1] plus [4+2] cycloaddition leads to polysubstituted 4‐aminoxanthones in excellent to quantitative yields at room temperature in a non‐catalyzed reaction.

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On the Involvement of a Spiroepoxide Intermediate in N‐Heterocyclic Carbene (NHC)‐Catalyzed Benzoin Condensations – An Approach by Oxygenation of Deoxy‐Breslow Intermediates
Authors: Berkessel Albrecht , Elfert Silvia
Published: February 2014

The involvement of a spiroepoxide, an isomer of the Breslow intermediate, in the catalytic cycle of the N‐heterocyclic carbene (NHC)‐catalyzed benzoin condensation was suggested by S. Gronert in 2007, based on calculations. To test this hypothesis, enediamines were generated in situ from (in part 13C‐labeled) N‐heterocyclic carbenes, benzyl bromide and base, and subsequently treated with various single‐oxygen atom oxidants. Clean oxidation occurred with a triazolylidene‐derived enediamine and an N‐sulfonyloxaziridine as oxidant, but NMR monitoring gave no hint to the accumulation of a spiroepoxide. Instead, oxidative cleavage of the enediamine to the free carbene and benzaldehyde was observed, with subsequent oxidation of the carbene to a urea. Presumably, electrophilic oxygenation of the enediamine occurs at the exocyclic methylene carbon atom and affords a zwitterion – identical to the primary carbene‐aldehyde adduct of the benzoin cycle – which undergoes retro‐cleavage to carbene and aldehyde. However, the occurrence of a spiroepoxide as transient intermediate of the oxidative CC bond cleavage cannot rigorously be excluded.

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Palladium‐Catalyzed [2+2+1] Oxidative Annulation of 4‐Hydroxycoumarins with Unactivated Internal Alkynes: Access to Spiro Cyclopentadiene‐Chroman‐2,4‐dione Complexes
Authors: Peng Shiyong , Gao Tao , Sun Shaofa , Peng Yanhong , Wu Minghu , Guo Haibing , Wang Jian
Published: February 2014

Herein, we report our new results regarding a palladium‐catalyzed [2+2+1] oxidative annulation of 4‐hydroxycoumarins with unactivated internal alkynes, which affords a new class of compounds: the spiro cyclopentadiene‐chroman‐2,4‐diones.

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Cobalt‐Catalyzed C‐4 Selective Alkylation of Quinolines
Authors: Yamamoto Shohei , Saga Yutaka , Andou Takashi , Matsunaga Shigeki , Kanai Motomu
Published: February 2014

The cobalt‐catalyzed direct C‐4 selective alkylation of quinolines is described. The reaction conditions used previously for pyridines were fully modified to achieve C‐4 selectivity in quinoline alkylation. Cobalt(II) acetate [Co(OAc)2] (2–4 mol%) in combination with butyllithium (BuLi) and pyridine was best, and C‐4 alkylation proceeded in 54–95% yield with C‐4/C‐2=>20:1–2.5:1 and branched/linear=>20:1 selectivity.

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Visible Light Photoredox Catalyzed Cascade Cyclizations of α‐Bromochalcones or α‐Bromocinnamates with Heteroarenes
Authors: Paria Suva , Reiser Oliver
Published: February 2014

Vinyl radicals were generated from α‐bromochalcones or α‐bromocinnamate ethyl ester under visible light photoredox catalyzed conditions via an oxidative quenching cycle of the iridium complex [Ir{dF(CF3)ppy}2(dtbbpy)]PF6 and subjected to cascade cyclizations with heteroarenes entailing two consecutive CC bond formations and three CH activations. The process is amenable to furans, benzofurans, pyrroles, and indoles, giving rise to a broad variety of novel polycyclic frameworks in high yields under mild and environmentally benign reaction conditions.

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Tungsten hexacarbonyl and hydrogen peroxide as precursors for the growth of tungsten oxide thin films on titania nanoparticles
Authors: Jackson David H. K. , Dunn Bryan A. , Guan Yingxin , Kuech Thomas F.
Published: February 2014

W(CO)6 and H2O2 were used in an atomic layer deposition (ALD)‐like process to grow thin WOx films onto TiO2 powders in a fluidized bed reactor. Carbonyl precursors are not widely used in this application, so that deviations from an ideal ALD process, previously not examined with W(CO)6, were identified. The resulting WOx films were a result of both ALD‐like and chemical vapor deposition‐based growth modes. A chemical reaction mechanism incorporating a combination of these two growth modes was inferred. As the move to expand the range of ALD precursors meets with the desire to scale up these processes, the simultaneous appearance of both these growth modes is likely to become more and more common, and so understanding the interaction of these two types of surface reactions is key to progress in the field. The films were observed to inhibit the anatase‐to‐rutile phase transformation in the TiO2 powders upon high temperature annealing, while crystallization of the amorphous WO3 was also not observed. Changes in the local bonding within the WO3 were observed and associated with changes in the structural nature of the film and its interface to the substrate. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1278–1286, 2014
Gold nanoparticle‐functionalized thread as a substrate for SERS study of analytes both bound and unbound to gold
Authors: Ballerini David R. , Ngo Ying H. , Garnier Gil , Ladewig Bradley P. , Shen Wei , Jarujamrus Purim
Published: February 2014

The potential of thread for use as a substrate for inexpensive, disposable diagnostics for surface‐enhanced Raman scattering (SERS) spectroscopy has been showed in this study. Gold‐nanoparticle coated thread can be embedded into fabrics to detect chemical or biological analytes in military and medical applications through SERS. Using this inexpensive and widely available material enables reduction in the volumes of nanoparticle solution required compared to alternatives. By testing multiple analytes, it was observed that molecular structure played a significant role in SERS signal amplification, and hence, the technique is limited to the detection of a small number of analytes possessing highly polarizable structures. Although direct chemical bonding between analyte molecules and nanoparticles gives the strongest signal enhancement, it remains possible to easily discern signals generated by analytes not directly bound, provided they possess suitable structure. Amplification of SERS signal by controlling the aggregation state of the gold nanoparticles to increase the number of SERS hotspots was observed. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1598–1605, 2014
Thermodynamic approach to interfacial transport phenomena: Single‐component systems
Authors: Öttinger Hans Christian , Venerus David C.
Published: February 2014

Balancing extensive quantities at interfaces in terms of excess densities is a subtle problem because these densities change with the precise location of the dividing surface within the interfacial region. We propose to handle such ambiguities for moving interfaces by introducing a gauge degree of freedom associated with the location of the dividing surface and by studying all the normal velocities associated with different excess densities. Unambiguous interfacial balance equations can then be obtained directly from the differences between normal velocities. By assuming local equilibrium, considering the interfacial entropy balance, and identifying the entropy production rate at the interface, we are naturally led to thermodynamically consistent constitutive assumptions for the fluxes characterizing transport in the interface and for the boundary conditions characterizing transport across the interface. The usefulness and generality of the proposed approach is illustrated in the context of several examples. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1424–1433, 2014
Direct Synthesis of 1,4‐Diols from Alkenes by Iron‐Catalyzed Aerobic Hydration and CH Hydroxylation
Authors: Hashimoto Takuma , Hirose Daisuke , Taniguchi Tsuyoshi
Published: February 2014

Various 1,4‐diols are easily accessible from alkenes through iron‐catalyzed aerobic hydration. The reaction system consists of a user‐friendly iron phthalocyanine complex, sodium borohydride, and molecular oxygen. Furthermore, the effect of additional ligands on the iron complex was examined for a model reaction. The second hydroxy group is installed by direct C(sp3)H oxygenation, which is based on a [1,5] hydrogen shift process of a transient alkoxy radical that is formed by formal hydration of the olefin.
Preparation and properties of high performance phthalide‐containing bismaleimide reinforced polydicyclopentadiene
Authors: Hu Fangyuan , Du Jie , Ou Tao , Zheng Yubin
Published: February 2014

A series of phenolphthalein‐containing bismaleimide (PPBMI) reinforced polydicyclopentadiene blends (PPBMI/polyDCPD) were prepared via the ring‐opening metathesis polymerization of DCPD in the presence of PPBMI. The crosslinked networks between PPBMI and polyDCPD backbones resulted in the reinforced structures. The curing behavior, thermal, and mechanical properties were investigated. Differential scanning calorimetry investigations showed the samples exhibit similar singular exothermic peak, and the exothermic peak of the PPBMI/polyDCPD blends slightly shifted to a lower temperature direction compared with the unfilled polyDCPD, meanwhile, the exothermic peak of the PPBMI/polyDCPD blends slightly shifts back to a higher temperature direction with the PPBMI content increased. Both dynamic mechanical analysis and thermo gravimetric analysis measurements revealed the optimal thermal performance of PPBMI/polyDCPD was obtained with 20 wt % loading of PPBMI. In addition, while PPBMI content increased, the weight loss peak at 100–200°C disappeared and the temperature of maximum rate of decomposition (Td,max) increased. Moreover, bending tests showed the best mechanical performance was achieved at 5 wt % loading of PPBMI in blends. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40474.
A comparative study on effect of aromatic polyimide chain conformation on reinforcement of carbon nanotube/polyimide nanocomposites
Authors: Zhang Baode , Chakoli Ali Nabipour , Zang Wanchen , Tian Yanqing , Zhang Ke , Chen Chunhai , Li Yao
Published: February 2014

Two kinds of polyimides (PIs) were selected as matrices for multiwalled carbon nanotubes (CNTs)‐based nanocomposites. The two PIs were initially synthesized through reactions of a same benzoxazole‐containing diamine with two different dianhydrids. A linear PI was formed from the ether bond‐containing dianhydride, while a nonlinear PI was formed from the C(CF3)2− groups containing dianhydride. Optimized dispersion of nanotubes in both kinds of PIs was found to be at a concentration with 0.5 wt % COOH‐CNT, where great enhancement was achieved for both PIs. It was also found that introducing nanotubes into PI matrices aroused more significant increase of Young's modulus and break stress in linear PI than that in nonlinear PI. To determine the key parameters involved in design of PIs for maximum reinforcement efficiency using CNT as the nanofiller, the nanoscopic dispersion state of the nanotubes in diamine solution and their reaction were investigated via morphological and spectroscopic studies. The interfacial interactions between nanotubes and two PI chains were characterized by FT‐IR and Raman spectroscopy. The fracture surface characteristics of two series of CNT/PI nanocomposites were further investigated using SEM. Our findings show that the diamine plays a double role for the in‐situ polymerization, a dispersant to disentangle the CNT agglomerates and a monomer for PI synthesis with dianhydrides. It was also found that geometry and flexibility of PI chains are crucial to determine the interfacial interactions between nanotubes and PI chains. For elucidating the different interfacial characteristics of the two PIs on the surface of CNT, we proposed a model for preferred conformation adopted by a single PI chain on a single CNT. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40479.
Critical Evaluation of Adsorption–Desorption Hysteresis of Heavy Metal Ions from Carbon Nanotubes: Influence of Wall Number and Surface Functionalization
Authors: Li Jie , Chen Changlun , Zhang Shouwei , Ren Xuemei , Tan Xiaoli , Wang Xiangke
Published: February 2014

Single‐, double‐, and multi‐walled carbon nanotubes (SWCNTs, DWCNTs, and MWCNTs), and two oxidized MWCNTs with different oxygen contents (2.51 wt % and 3.5 wt %) were used to study the effect of the wall number and surface functionalization of CNTs on their adsorption capacity and adsorption–desorption hysteresis for heavy metal ions (NiII, CdII, and PbII). Metal ions adsorbed on CNTs could be desorbed by lowering the solution pH. Adsoprtion of heavy metal ions was not completely reversible when the supernatant was replaced with metal ion‐free electrolyte solution. With increasing wall number and amount of surface functional groups, CNTs had more surface defects and exhibited higher adsorption capacity and higher adsorption–desorption hysteresis index (HI) values. The coverage of heavy metal ions on the surface of CNTs, solution pH, and temperature affect the metal ion adsorption–desorption hysteresis. A possible shift in the adsorption mechanism from mainly irreversible to largely reversible processes may take place, as the amount of metal ions adsorbed on CNTs increases. Heavy metal ions may be irreversibly adsorbed on defect sites.
Enhancement of Host–Guest Interactions Using Rationally Designed Macrocyclic Boronic Esters with a Naphthalene Core
Authors: Kikuchi Yuji , Takahagi Hiroki , Ono Kosuke , Iwasawa Nobuharu
Published: February 2014

Efficient inclusion of electron‐deficient aromatic guest molecules in an organic solvent utilizing π‐stacking interactions was achieved by using two kinds of macrocyclic boronic esters, 1,4‐naph‐[2+2] and 1,5‐naph‐[2+2], which were easily prepared by self‐assembly of 1,4‐naphthalenediboronic acid (3) or 1,5‐naphthalenediboronic acid (4) and racemic tetrol 1 with an indacene framework in a protic solvent. The X‐ray crystallographic analyses revealed that the tilt angles of the two naphthalene rings are different: that of 1,4‐naph‐[2+2] is about 15° and that of 1,5‐naph‐[2+2] is about 0°. Owing to the parallel alignment of two aromatic rings, 1,5‐naph‐[2+2] has a much higher binding ability than 1,4‐naph‐[2+2]. This knowledge could be useful for the design of the new host molecules in organic solvents.
Switchable Dielectric Phase Transition Induced by a Twisting Transformation in Diglycine Methanesulfonate
Authors: Zhou Pan , Sun Zhihua , Zhang Shuquan , Chen Tianliang , Ji Chengmin , Zhao Sangen , Luo Junhua
Published: February 2014

A new glycine‐based reversible phase transition compound diglycine methanesulfonate (1) has been successfully synthesized. Differential scanning calorimetry (DSC) measurements of 1 showed a pair of broad peaks around 134 K (Tc=phase transition temperature) with a slight thermal hysteresis during the heating/cooling cycle, thereby indicating that this compound undergoes a reversible second‐order phase transition. Dielectric measurements further confirmed the phase transition and revealed a switchable response to the ambient temperature change for the dielectric constants of 1, namely, the dielectric constants have a distinctive step‐like anomaly switching between a high dielectric state in the room temperature phase (RTP) and a low state in the low temperature phase (LTP). Variable‐temperature single‐crystal X‐ray diffraction analyses show that 1 undergoes an atypical transition from the space group P21/m in the RTP to P21/c in the LTP. The origin of the switchable dielectric phase transition is ascribed to the movement of the moieties in 1 from the equilibrium position, and this stems from the twisting of the molecules in the compound. We believe that these findings will be useful in exploring switchable dielectric phase transition materials.
Vehicle trajectory reconstruction using automatic vehicle identification and traffic count data
Authors: Feng Yu , Sun Jian , Chen Peng
Published: February 2014

The origin–destination (OD) matrix and the vehicle trajectory data are critical to transportation planning, design, and operation management. On the basis of the deployment of automatic vehicle identification (AVI) technology in urban traffic networks in China, this study proposed a vehicle trajectory reconstruction method for a large‐scale network by using AVI and traditional detector data. Particle filter theory was employed as the framework for this method that combines five spatial‐temporal trajectory correction factors (i.e., the path consistency, the AVI measurability criterion, the travel time consistency, the gravity flow model, and the path‐link flow matching model) to estimate the trajectory of a vehicle. The probabilities of the most likely trajectories are updated by the Bayesian method to approximate the ‘true’ trajectory. The traffic network in the Beijing Olympic Park was selected as the test bed and was simulated by using VISSIM to create a complete set of vehicle trajectories. The accuracy of the resulting trajectory reconstruction exceeds 90% when the AVI coverage is only 50%, assuming an AVI detection error of 5% for a closed network and an open network. The average relative error of a static OD matrix is 11.05%. Although the accuracy of reconstruction exceeds 80% when the AVI coverage is between 50% and 40%, the accuracy of a defective product‐OD matrix decreases rapidly. The proposed method yields high estimation accuracy for the full trajectories of individual vehicles and the OD matrix, which demonstrates significant potential for traffic‐related applications. Copyright © 2014 John Wiley & Sons, Ltd.
Entwicklung verschleißarmer Fahrbahnübergangskonstruktionen
Authors: Zimmermann Thomas , Friedrich Henriette Pauline , Strauss Alfred , Lachinger Stefan , Binder Fritz , Gabl Thomas , Zlatarits Jakob , Schön Andreas , Hoffmann Simon
Published: February 2014

Fahrbahnübergangskonstruktionen an Brücken sind aufgrund ihrer Position hochdynamisch belastete Strukturelemente. Fahrbahnübergänge zählen nach Eurocode 0 zu den erneuerbaren strukturellen Komponenten und sollten somit für eine Lebensdauer von zehn bis 25 Jahren und mehr ausgelegt werden. Unabhängig von der Entwurfslebensdauer besteht ein Bedarf, den Erhaltungsaufwand von Fahrbahnübergängen zu minimieren. Das Forschungsprojekt “Entwicklung verschleißarmer Fahrbahnübergangskonstruktionen” (EVAF) hat daher die Zielsetzung, auf Basis umfangreicher Schadenserhebungen, Literaturstudien und numerischer Beanspruchungsanalysen die Ursachen für frühzeitige Schäden zu ermitteln und in Folge für einzelne Typen von Fahrbahnübergangskonstruktionen innovative Lösungen zur Verringerung des Erhaltungsaufwandes und zur Schadensvermeidung zu entwickeln. Es sollen robuste, wartungsarme und mit geringem Aufwand instand zu setzende Fahrbahnübergangskonstruktionen (FÜK) entwickelt werden. Dieser Beitrag zeigt die Erkenntnisse, welche in den beiden ersten Arbeitspaketen (AP1 und AP2) aus den Erhebungen und numerischen Analysen, welche durch das intensive Zusammenwirken der Auftraggeber BMViT, ASFINAG, ÖBB, dem industriellen Partner Mageba und den Forschungspartnern AIT (Austrian Institute of Technology) und der Universität für Bodenkultur im Zuge der Forschungsinitiative vif2012 gewonnen werden konnten.

Development of low‐wear road expansion joints – Research project EVAF

Roadway expansion joints for bridges are highly dynamically loaded structural elements due to their position. Expansion joints are renewable structural components according to Eurocode 0 and should therefore be designed for a service life of ten to 25 and more years. Regardless of the design life there is a need to minimize effort of conservation of such expansion joints. The research project “Development of wear‐resistant expansion joints for bridges” (EVAF) therefore has the objective on the basis of a comprehensive damage surveys, literature studies and numerical stress analysis to determine the causes of early damage patterns and to develop innovative solutions to reduce the maintenance effort and further to avoid the damage with respect to the individual types of expansion joints for bridges. Thereby robust, low‐maintenance, with low cost serviced expansion joints for bridges should be developed. This paper shows the outcomes of the first two work packages from the surveys and numerical analyzes which have been carried out due to the intense interaction between the customer bmvit, ASFINAG and ÖBB as well as the industrial partner Mageba and the research partners AIT (Austrian Institute of Technology) and University of Natural Resources and Life Sciences Vienna within the research initiative vif2012.
Der König ist tot. Lang lebe der König.
Authors: Bluhm Ján
Published: February 2014

Im Zuge des Ersatzneubaus der Sinntalbrücke auf der Bundesautobahn A7 bei Bad Brückenau wurde am 22. Juni 2013 die alte Sinntalbrücke mit einer Länge von 770 m durch Sprengen abgerissen. Aufgrund der fehlenden Erfahrungen in Deutschland mit dem Sprengabbruch von Brückenbauwerken dieser Größenordnung wurde dem Auftraggeber ein entsprechendes Abbruchkonzept inklusive statischer Berechnungen vorgelegt, welches auch die Wirkung von Erschütterungen auf benachbarte bauliche Anlagen beurteilte. Da beide Brückenbauwerke nur wenige Meter voneinander entfernt standen, waren eine fachliche Überprüfung dieser Planungsunterlagen, eine umfassende Beweissicherung ausgewählter baulicher und technischer Anlagen sowie vergleichende Erschütterungsprognosen und ‐messungen nach DIN 4150 notwendig. Diese Aufgabe übernahm die Bluhm Partner AG im März 2013. Der vorliegende Beitrag gibt einen Überblick zum Abbruchkonzept, zur Beweissicherung sowie zu den Erschütterungsprognosen und ‐messungen.

The king is dead. Long live the king. The demolition of the old Sinntal Bridge near Bad Brückenau (Germany)

As part of the new construction replacement of the Sinntal bridge on the A7 motorway at Bad Brückenau on 22 June 2013 the old Sinntal bridge with a length of 770 m was demolished by blasting. Due to the lack of experience in Germany with the blasting demolition of bridges of this size an appropriate demolition concept including static calculations was presented to the client, which also evaluated the effect of vibrations on adjacent buildings and structures. Since both bridges were only a few meters apart, a technical review of the planning documents, a comprehensive preservation of evidence of selected structural and technical facilities as well as comparative vibration predictions and measurements according to DIN 4150 were necessary. This task was given to the Bluhm Partner AG in March 2013. This article gives an overview of the demolition concept, the preservation of evidence and the vibration predictions and measurements.
Zuverlässigkeitsanalyse von Massivbrücken für außergewöhnliche Bedrohungsszenarien
Authors: Boros Vazul , Novák Balthasar
Published: February 2014

Brücken spielen eine zentrale Rolle im Straßenverkehrsnetz, sind jedoch zugleich zahlreichen Gefahren ausgesetzt. Um den erforderlich Schutz für diese wichtigen Infrastrukturbauwerke gewährleisten zu können, müssen potenzielle Bedrohungen identifiziert, die Kritikalität von Brücken beurteilt und die Wirksamkeit von Schutzmaßnahmen bewertet werden. Es wird eine Methodik aufgezeigt, mit der eine quantitative Beurteilung der Tragwerkszuverlässigkeit für verschiedene Bauwerke und Szenarien erfolgen kann, damit solche Analysen vorgenommen werden können. An Beispielszenarien werden zudem die Ergebnisse einer Risikoanalyse vorgestellt und bewertet. Schließlich wird ein neuer Indikator für die Zuverlässigkeit von Massivbrücken eingeführt, der eine vereinfachte Abschätzung der Tragwerkssicherheit ermöglicht.

Reliability analysis of concrete bridges for hazard scenarios

Bridges play a vital role in the highway network, yet are also subject to numerous hazards. In order to protect these important elements of the infrastructure, potential hazards have to be identified, the criticality of bridges needs to be assessed and the efficiency of protection measures has to be evaluated. To achieve this, a methodology is shown, how for different structures and scenarios the reliability can be quantified. Furthermore on sample scenarios the results of a risk analysis are displayed and evaluated. Finally a new indicator of reliability for reinforced concrete bridges is introduced, enabling a simplified estimation of structural safety.
Planung und Bau einer semiintegralen Eisenbahnüberführung in Walzträger‐in‐Beton (WiB)‐Bauweise
Authors: Brunner Andreas , Frühauf Wolfgang , Kotz Peter , Schantz Torsten , Windisch Daniel
Published: February 2014

Die aus dem Jahr 1898/99 stammende Eisenbahnüberführung Großenhainer Straße in Dresden entspricht nicht mehr den gestellten Anforderungen. Sie wird als moderne semiintegrale Dreifeldbrücke in Walzträger‐in‐Beton (WiB)‐Bauweise mit zwei zweigleisigen Überbauten unter laufendem Eisenbahnverkehr und unter innerstädtischem Fahrzeug‐ und Straßenbahnverkehr erneuert. Unter den vorgegebenen schwierigen Randbedingungen stellt sie eine innovative und äußerst anspruchsvolle Ingenieuraufgabe dar. Dem sensiblen innerstädtischen Raum geschuldet waren besondere gestalterische Vorgaben zu erfüllen. Mit der neuen Eisenbahnüberführung Großenhainer Straße wird ein gestalterisch, konstruktiv und funktional hervorragendes Bauwerk geschaffen.

Design and construction of a semi‐integral railway overpass using the “rolled steel girders in concrete” (WiB) construction method

The existing railway overpass “Großenhainer Straße” in Dresden, built in 1898/99, does not comply to the latest requirements. The structure will be replaced by a modern three‐span‐bridge in “rolled steel girders in concrete” (WiB) construction method with two superstructures with double track lines. During construction the rail traffic, motor vehicles and tramway will be continuously in service. With respect to the present boundary conditions, the structure represents an innovative and extremely ambitious engineering task. Due to the sensitive urban environment, ambitious visual design requirements have to be fulfilled. The new railway bridge “Großenhainer Straße” is an outstanding structure in respect of architectural and technical design as well as functionality.
In vitro response to functionalized self‐assembled peptide scaffolds for three‐dimensional cell culture
Authors: Modepalli Vengama N. , Rodriguez Alexandra L. , Li Rui , Pavuluri Sivapriya , Nicholas Kevin R. , Barrow Colin J. , Nisbet David R. , Williams Richard J.
Published: February 2014

Nanomaterials are rich in potential, particularly for the formation of scaffolds that mimic the landscape of the host environment of the cell. This niche arises from the spatial organization of a series of biochemical and biomechanical signals. Self‐assembling peptides have emerged as an important tool in the development of functional (bio‐)nanomaterials; these simple, easily synthesized subunits form structures which present the properties of these larger, more complex systems. Scaffolds based upon these nanofibrous matrices are promising materials for regenerative medicine as part of a new methodology in scaffold design where a “bottom‐up” approach is used in order to simulate the native cellular milieu. Importantly, SAPs hold the potential to be bioactive through the presentation of biochemical and biomechanical signals in a context similar to the natural extracellular matrix, making them ideal targets for providing structural and chemical support in a cellular context. Here, we discuss a new methodology for the presentation of biologically relevant epitopes through their effective presentation on the surface of the nanofibers. Here, we demonstrate that these signals have a direct effect on the viability of cells within a three‐dimensional matrix as compared with an unfunctionalized, yet mechanically and morphologically similar system. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 197–205, 2014.
Improved chemical synthesis of hydrophobic Aβ peptides using addition of C‐terminal lysines later removed by carboxypeptidase B
Authors: Chemuru Saketh , Kodali Ravindra , Wetzel Ronald
Published: February 2014

Many amyloidogenic peptides are highly hydrophobic, introducing significant challenges to obtaining high quality peptides by chemical synthesis. For example, while good yield and purity can be obtained in the solid‐phase synthesis of the Alzheimer's plaque peptide Aβ40, addition of a C‐terminal Ile‐Ala sequence to generate the more toxic Aβ42 molecule creates a much more difficult synthesis resulting in low yields and purities. We describe here a new method that significantly improves the Fmoc solid‐phase synthesis of Aβ peptides. In our method, Lys residues are linked to the desired peptide's C‐terminus through standard peptide bonds during the synthesis. These Lys residues are then removed post‐purification using immobilized carboxypeptidase B (CPB). With this method we obtained both Aβ42 and Aβ46 of superior quality that, for Aβ42, rivals that obtained by recombinant expression. Intriguingly, the method appears to provide independent beneficial effects on both the total synthetic yield and on purification yield and final purity. Reversible Lys addition with CPB removal should be a generally useful method for making hydrophobic peptides that is applicable to any sequence not ending in Arg or Lys. As expected from the additional hydrophobicity of Aβ46, which is extended from the sequence Aβ42 by a C‐terminal Thr‐Val‐Ile‐Val sequence, this peptide makes typical amyloid at rates significantly faster than for Aβ42 or Aβ40. The enhanced amyloidogenicity of Aβ46 suggests that, even though it is present in relatively low amounts in the human brain, it could play a significant role in helping to initiate Aβ amyloid formation. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 206–221, 2014.
The anatomy of nuchal translucency at 10–14 weeks gestation in fetuses with Trisomy 21: An incredible medical mystery
Authors: Nafziger Elizabeth , Vilensky Joel A.
Published: February 2014

Nuchal translucency (NT) is a hypo‐echoic region of subcutaneous fluid accumulation in the posterior neck at the level of the cervical spine between the skin and soft tissues found at 10–14 weeks gestation. This ultrasound finding is important because increased NT measurements place the fetus at increased risk for chromosomal and structural abnormalities. It is a fascinating phenomenon that displays the intersection of anatomy, development, and imaging. In addition, with the ever increasing use of ultrasound in anatomy, NT is a readily demonstrable example of how important ultrasound has become to the practice of medicine. Articles on NT were obtained from OVID database and reviewed for their contribution to an understanding of the anatomical basis of NT. Whereas it is well established that the ultrasound finding of increased NT is a sensitive marker for Trisomy 21 at 10–14 weeks gestation, why this phenomena occurs has yet to be explained. The basis of nuchal edema is most likely multifactorial, a combination of delayed or disturbed lymphangiogenesis, cardiac and vascular abnormalities, and abnormal extracellular matrix components. Further research on the development of the fetal head and neck related to lymphatic development and fluid regulation during 8–14 weeks gestation will enable a greater understanding of how and why increased NT occurs compared to what is currently known. This could lead to early intervention to manage some of the repercussions of Trisomy 21 and other abnormalities related to NT. Clin. Anat. 27:353–359, 2014. © 2014 Wiley Periodicals, Inc.
Asymmetric Total Synthesis of Onoseriolide, Bolivianine, and Isobolivianine
Authors: Du Biao , Yuan Changchun , Yu Tianzi , Yang Li , Yang Yang , Liu Bo , Qin Song
Published: February 2014

In this article, we describe our efforts on the total synthesis of bolivianine (1) and isobolivianine (2), involving the synthesis of onoseriolide (3). The first generation synthesis of bolivianine was completed in 21 steps by following a chiral resolution strategy. Based on the potential biogenetic relationship between bolivianine (1), onoseriolide (3), and β‐(E)‐ocimene (8), the second generation synthesis of bolivianine was biomimetically achieved from commercially available (+)‐verbenone in 14 steps. The improved total synthesis features an unprecedented palladium‐catalyzed intramolecular cyclopropanation through an allylic metal carbene, for the construction of the ABC tricyclic system, and a Diels–Alder/intramolecular hetero‐Diels–Alder (DA/IMHDA) cascade for installation of the EFG tricyclic skeleton with the correct stereochemistry. Transformation from bolivianine to isobolivianine was facilitated in the presence of acid. The biosynthetic mechanism and the excellent regio‐ and endo selectivities in the cascade are well supported by theoretical chemistry based on the DFT calculations.
Cleavage of the CN Bond in Carbodiimides via Release of High Ring Strain: A New Strategy for the Selective Synthesis of 2‐Aminoaryl Alkynyl Imines
Authors: Zhou Yi , Chi Yue , Zhao Fei , Zhang Wen‐Xiong , Xi Zhenfeng
Published: February 2014

A novel pattern of the cleavage and reorganization of CN bond in the multicomponent reaction (MCR) of terminal alkynes or haloalkynes, carbodiimides, and benzynes is achieved for the first time to construct efficiently 2‐aminoaryl alkynyl imines. The selective formation and ring‐opening of the azetine intermediate with the high ring strain is essential for this reaction. Further transformation of 2‐aminoaryl alkynyl imines via the Cu‐catalyzed cycloisomerization is explored to provide steroselectively the bi‐, tri‐, and tetracyclic fused pyrrolines.
Palladium‐Catalyzed Direct Thiolation of Aryl CH Bonds with Disulfides
Authors: Iwasaki Masayuki , Iyanaga Miki , Tsuchiya Yuta , Nishimura Yugo , Li Wenjuan , Li Zhiping , Nishihara Yasushi
Published: February 2014

A catalytic variant of the direct thiolation of arenes, bearing directing groups, with disulfides or thiols has been developed under palladium and copper co‐catalysis. Both sulfenyl moieties of the disulfide could be incorporated into the thiolated products, therefore, the reactions reached completion with only half an equivalent of disulfide, with respect to the starting arene. Experimental evidence suggested that the reaction proceeds through a PdII/PdIV mechanism.
Electrocatalytically Switchable CO2 Capture: First Principle Computational Exploration of Carbon Nanotubes with Pyridinic Nitrogen
Authors: Jiao Yan , Zheng Yao , Smith Sean C. , Du Aijun , Zhu Zhonghua
Published: February 2014

Carbon nanotubes with specific nitrogen doping are proposed for controllable, highly selective, and reversible CO2 capture. Using density functional theory incorporating long‐range dispersion corrections, we investigated the adsorption behavior of CO2 on (7,7) single‐walled carbon nanotubes (CNTs) with several nitrogen doping configurations and varying charge states. Pyridinic‐nitrogen incorporation in CNTs is found to induce an increasing CO2 adsorption strength with electron injecting, leading to a highly selective CO2 adsorption in comparison with N2. This functionality could induce intrinsically reversible CO2 adsorption as capture/release can be controlled by switching the charge carrying state of the system on/off. This phenomenon is verified for a number of different models and theoretical methods, with clear ramifications for the possibility of implementation with a broader class of graphene‐based materials. A scheme for the implementation of this remarkable reversible electrocatalytic CO2‐capture phenomenon is considered.
Water Electrolysis with a Conducting Carbon Cloth: Subthreshold Hydrogen Generation and Superthreshold Carbon Quantum Dot Formation
Authors: Biswal Mandakini , Deshpande Aparna , Kelkar Sarika , Ogale Satishchandra
Published: February 2014

A conducting carbon cloth, which has an interesting turbostratic microstructure and functional groups that are distinctly different from other ordered forms of carbon, such as graphite, graphene, and carbon nanotubes, was synthesized by a simple one‐step pyrolysis of cellulose fabric. This turbostratic disorder and surface chemical functionalities had interesting consequences for water splitting and hydrogen generation when such a cloth was used as an electrode in the alkaline electrolysis process. Importantly, this work also gives a new twist to carbon‐assisted electrolysis. During electrolysis, the active sites in the carbon cloth allow slow oxidation of its surface to transform the surface groups from COH to COOH and so forth at a voltage as low as 0.2 V in a two‐electrode system, along with platinum as the cathode, instead of 1.23 V (plus overpotential), which is required for platinum, steel, or even graphite anodes. The quantity of subthreshold hydrogen evolved was 24 mL cm−2 h−1 at 1 V. Interestingly, at a superthreshold potential (>1.23 V+overpotential), another remarkable phenomenon was found. At such voltages, along with the high rate and quantity of hydrogen evolution, rapid exfoliation of the tiny nanoscale (5–7 nm) units of carbon quantum dots (CQDs) are found in copious amounts due to an enhanced oxidation rate. These CQDs show bright‐blue fluorescence under UV light.
Low‐Temperature Activation of Hematite Nanowires for Photoelectrochemical Water Oxidation
Authors: Ling Yichuan , Wang Gongming , Wang Hanyu , Yang Yi , Li Yat
Published: February 2014

Hematite (α‐Fe2O3) nanostructures have been extensively studied as photoanode materials for photoelectrochemical (PEC) water oxidation. However, the photoactivity of pristine hematite nanostructures is fairly low and typically requires thermal activation at temperature of 650 °C or above. Here, we report a new method for enhancing the photocurrent of hematite nanowires at a substantially lower temperature of 350 °C by means of a two‐step annealing process (activation process). Hydrothermally grown β‐FeOOH nanowires were first annealed in a pure N2 environment at 350 °C to form magnetite, followed by partial oxidation in air to convert magnetite to hematite. During this process, Fe2+ sites (oxygen vacancies) were intentionally created to increase the donor density and therefore the electrical conductivity of hematite. The oxygen‐deficient hematite nanowire photoanode created at low temperature (350 °C) show considerably enhanced photoactivity compared to pristine hematite sample that prepared by thermal annealing of β‐FeOOH nanowires at 550 °C in air. Moreover, this low‐temperature annealing method can be coupled with an element doping method to further increase the photoactivity of hematite nanowire. Sn‐doped hematite nanowires prepared by the same low‐temperature annealing method show at least three fold enhanced photocurrent compared to the undoped sample. Significantly, the highest temperature in the entire annealing process was 350 °C, which is the lowest activation temperature ever reported for hematite nanowire photoanodes.
Electrocatalytically Switchable CO2 Capture: First Principle Computational Exploration of Carbon Nanotubes with Pyridinic Nitrogen
Authors: Jiao Yan , Zheng Yao , Smith Sean C. , Du Aijun , Zhu Zhonghua
Published: February 2014

The front cover artwork for issue 12/2013 is provided by the group of Prof. Zhonghua Zhu, in collaboration with Prof. Sean C. Smith of Oak Ridge National Laboratory, and Prof. Aijun Du from Queensland University of Technology. The image shows how carbon nanotubes and/or graphene with doped pyridinic nitrogen could be applied for controllable, highly selective, and reversible CO2 capture. The Full Paper itself is available at 10.1002/cssc.201300624
Ion Charge Separation in a Multi‐Species Plasma Flowing through a Magnetic Transport System
Authors: Paperny V. L. , Korobkin Yu. V. , Krasov V. I. , Lebedev N. V.
Published: February 2014

Energy spectra of ions of various charged states at different cross‐section of a titanium plasma flow produced with a dc vacuum arc were studied. It was established that ions with different charges states were spatially separated during their travel through a plasma transport system based on a curved magnetic field. Ions with greater charge states were concentrated in the inner part of the curved plasma flow, i.e. closer to the centre of curvature of the field lines, so that the average charge state of ions in this area was higher than that at the outer part of the flow. A computer simulation of guiding a multi‐species plasma flow by a curved magnetic field qualitatively agreed with the experimental data. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Throwing Light on Water Oxidation
Authors: Hindson Karen J.
Published: February 2014

EurJIC brings you a fine collection of studies into the dynamic, stimulating and highly topical field of Water Oxidation. Guest Editors Dennis Hetterscheid and Licheng Sun enthusiastically provided their broad expertise on this topic to compile an issue containing many different points of view on this very important subject.