bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brückenertüchtigung – eine notwendige Voraussetzung für ein zuverlässiges Fernstraßennetz
Authors: Colditz Brit 
Published: March 2013

AbstractDas prognostizierte Verkehrsaufkommen geht von einer starken Zunahme des Güterverkehrs auf den Straßen aus. Dies wird zukünftig zu einer noch stärkeren Auslastung und damit zu einer noch größeren Beanspruchung der Brücken führen. Viele ältere Brücken können den stetig wachsenden Anforderungen nicht mehr uneingeschränkt standhalten. Bei diesen Bauwerken, darunter auch zahlreiche große Tal‐ und Strombrücken, treten zunehmend Abnutzungserscheinungen und Schäden auf. Sie befinden sich fast ausschließlich in den alten Bundesländern. Es stellt sich die Frage, wie diese Brücken weiter genutzt oder auch ertüchtigt werden können. Mit der vom Bundesministerium für Verkehr, Bau und Stadtentwicklung entwickelten Strategie zur Nachrechnung und Ertüchtigung des Brückenbestandes wurde gemeinsam mit der Bundesanstalt für Straßenwesen und den Straßenbauverwaltungen der Länder ein bundeseinheitliches Vorgehen erarbeitet. Dieses Konzept sieht vor, bei jeder einzelnen der betroffenen Brücken zu prüfen, ob sie den Anforderungen des heutigen und zukünftigen Schwerverkehrs noch genügt. Die eigens dafür erarbeitete so genannte Nachrechnungsrichtlinie bildet das Kernstück dieser Aufgabe. Es gilt, sowohl den Bauwerkszustand der Straßenbrücken zu verbessern als auch Defizite bei der Tragfähigkeit zu beseitigen. Ziel aller Anstrengungen muss es sein, umfangreiche Verkehrseinschränkungen bis hin zur Sperrung einer Brücke zu verhindern.Bridge strengthening – a necessary prerequisite for a reliable highway networkThe traffic forecast assumes a sharp increase in goods transport by road. In the future, this will result in an even higher traffic load and thus to an even higher degree of wear of the bridges. Many older bridges can no longer fully meet the continually increasing requirements. These structures, including many large valley and river bridges, are affected more and more by wear and tear and damages. They are located almost exclusively in the old federal states. The question arises as to how these bridges can be used or even strengthened in the future. With the strategy for post‐test calculations and strengthening of the bridge stock developed by the Federal Ministry of Transport, Building and Urban Development a nationally uniform approach was elaborated together with the Federal Highway Institute and the road construction administration of the federal states. This concept aims at examining for everyone of the individual bridges concerned whether it still meets the requirements of heavy‐goods transport today and in the future. The so‐called post‐test calculation guideline specially developed for this purpose forms the core of this task. What needs to be done is to improve the structural condition of the road bridges as well as to eliminate deficits of the load‐bearing capacity. The objective of all efforts has to be the prevention of extensive traffic restrictions up to the closure of a bridge.
Überwerfungsbauwerke VleuGel, Utrecht
Authors: Breuer Klaus 
Published: March 2013

AbstractDie Eisenbahnstrecken in den Niederlanden gehören zu den am stärksten belasteten Strecken der Welt. Mit dem Projekt “VleuGel” bei Utrecht wird durch die Gleiserweiterung deutlich mehr Streckenkapazität geschaffen. Technisch anspruchsvoll sind insbesondere drei Bauwerke: “Diveunders”, “Viadukt A27” und “Unterführung Fortweg”. Für die “Diveunders” benötigt man 31650 m2 dauerhafte Schlitzwände für ein neues Überwerfungsbauwerk. Die Herstellung erfolgte bei laufendem Gleisbetrieb zwischen den Bahngleisen und der angrenzenden Bebauung. An die sichtbaren Schlitzwände wurden hohe Anforderungen hinsichtlich Betonqualität, Wasserdichtigkeit und Maßgenauigkeit gestellt. Heijmans Civiel (Rosmalen, NL) erhielt den Auftrag von ProRail für die komplette Baumaßnahme und beauftragte die Franki Grundbau mit der Ausführung der Schlitzwandarbeiten.Crossing construction, VleuGel, UtrechtThe railway lines in the Netherlands are among the busiest in the world. The “VleuGel” project near Utrecht will create significantly more rail capacity by providing more track. Three structures are particularly technically demanding: “Dive unders”, “Viaduct A27” and “Fortweg Underpass”. For the “Dive unders” 31650 m2 of permanent diaphragm wall were needed for the construction of the crossing. The construction was carried out between the rail tracks and the adjoining developments under continuing rail traffic. High demands were made on the visible diaphragm walls in regard to quality of the concrete, watertightness and dimensional accuracy. ProRail awarded the contract for the complete building construction to Heijmans Civiel (Rosmalen, NL), who contracted Franki Grundbau with the construction of the diaphragm walls.
Zur Planung und Ausführung von Ziegeldecken nach neuer DIN 1045‐100 mit Eurocode 2
Authors: Fingerloos Frank , Jedamzik Heinz‐Werner , Kranzler Thomas 
Published: March 2013

AbstractZiegeldecken (früher auch als “Stahlsteindecken” bezeichnet) bestehen aus Deckenziegeln, Betonrippen und Betonstahl, deren Zusammenwirken im Verbund zur Aufnahme der Schnittgrößen erforderlich ist. Ziegeldecken weisen gegenüber vergleichbaren Vollplatten aus Ortbeton geringere Eigenlasten und teilweise günstigere bauphysikalische Eigenschaften auf. Sie sind relativ einfach auf der Baustelle zu verlegen, zu bewehren und auszubetonieren. Sie eignen sich daher auch besonders gut beim Bauen im Bestand. In der Regel werden Ziegeldecken heutzutage jedoch als vorgefertigte Deckenelemente im Neubau verlegt. Ende 2011 wurde eine überarbeitete Ausgabe DIN 1045‐100: “Bemessung und Konstruktion von Stahlbeton‐ und Spannbetontragwerken – Teil 100: Ziegeldecken” herausgegeben. Diese wurde zusammen mit dem Eurocode 2 im Juli 2012 bauaufsichtlich in Deutschland eingeführt. Im folgenden Beitrag wird auf die Überarbeitung der normativen Regeln für Ziegeldecken und auf ihre Bemessung und Ausführung eingegangen.Design and construction of clay block floor plates in accordance with new DIN 1045‐100 and Eurocode 2Floor plates made with clay blocks (formerly also referred to as “reinforced block slabs”) consist of special clay blocks for floors, concrete ribs and reinforcing steel. These three components form a bond that is necessary to take up the internal forces. Compared to solid cast‐in‐place slabs, clay block floor plates have a lower self weight and, to a certain extent, more favorable thermal characteristics. It is relatively easy to lay the clay blocks on a formwork, to reinforce and to concrete the ribs. They are thus particularly suitable for modernizing and upgrading existing buildings. Nowadays in general brick clay block floor plates are installed as precast floor elements in new construction projects.At the end of 2011 a revised standard DIN 1045‐100: Design and construction of reinforced concrete and prestressed concrete structures – Part 100: Brick floors has been published in order to be introduced in Germany together with Eurocode 2 in July 2012. The following paper gives an overview about the overwork of the standard rules for clay block floor plates and about their design and construction.
Plattenbalken mit Querkraftverstärkung aus Textilbeton unter nicht vorwiegend ruhender Belastung
Authors: Brückner Anett , Wellner Sabine , Ortlepp Regine , Scheerer Silke , Curbach Manfred 
Published: March 2013

AbstractAufbauend auf den Ergebnissen des SFB 528 “Textile Bewehrungen zur bautechnischen Verstärkung und Instandsetzung” wurde in einem DAfStb‐Forschungsvorhaben die Querkrafttragfähigkeit von textilbetonverstärkten Plattenbalken unter nicht vorwiegend ruhender Beanspruchung untersucht. Im Sinne einer Machbarkeitsstudie wurden insgesamt drei Plattenbalken statisch belastet und sieben einer Schwellbelastung mit zwei Millionen Lastwechseln mit einem Dauerlastanteil von 80 % und einer Schwingbreite von 30 % – beides bezogen auf die Gebrauchslast – unterzogen. Es wurden unverstärkte Referenzbalken und mit Textilbeton verstärkte Probekörper getestet. Um ein Querkraftversagen der verstärkten sowie der nicht verstärkten Plattenbalken zu erreichen, wurde die Stahlbügelbewehrung auf die Mindestbewehrung reduziert. Als Verstärkungstextil wurde ein Multiaxialgelege aus Carbonfasern verwendet. Die umfangreiche Bestückung mit Messmitteln und die Kombination verschiedener Messmethoden ermöglichte sowohl die Beobachtung des globalen Strukturverhaltens als auch lokaler Effekte. Im vorliegenden Aufsatz werden die Versuche beschrieben und die wichtigsten Ergebnisse vorgestellt.T‐beams strengthened with TRC under non predominantly static loadingBased on the results of the DFG Collaborative Research Center 528 “Textile Reinforcements for Structural Strengthening and Repair”, the shear resistance of T‐beams strengthened with textile reinforced concrete (TRC) was investigated under non predominantly static loading in a research project funded by the DAfStb. For the purpose of a feasibility study T‐beams were performed in 3‐point bending tests. Three beams were loaded statically and seven beams cyclically. During two million cycles, the continuous part of the load mounted to 80 % of the service load; the stress range made up ± 15 % of this value. We tested unreinforced reference beams and with TRC reinforced specimens. To achieve a shear failure, the steel stirrups were reduced to the minimum reinforcement. A multiaxial fabric made of carbon fibres was used as strengthening reinforcement. The extensive use of measuring instruments and the combination of different measurement methods allowed the observation of both the global structural behaviour as well as local effects. In this paper, the experiments and main results are described.
From deep sequencing to viral tagging: Recent advances in viral metagenomics
Authors: Willner Dana , Hugenholtz Philip 
Published: March 2013

AbstractCulture‐independent high‐throughput sequencing has provided unprecedented insights into microbial ecology, particularly for Earth's most ubiquitous and diverse inhabitants – the viruses. A plethora of methods now exist for amplifying the vanishingly small amounts of nucleic acids in natural viral communities in order to sequence them, and sequencing depth is now so great that viral genomes can be detected and assembled even amid large concentrations of non‐viral DNA. Complementing these advances in amplification and sequencing is the ability to physically link fluorescently labeled viruses to their host cells via high‐throughput flow sorting. Sequencing of such isolated virus–host pairs facilitates cultivation‐independent exploration of the natural host range of viruses. Within the next decade, as these technologies become widespread, we can expect to see a systematic expansion of our knowledge of viruses and their hosts.
Rhythm of carbon and nitrogen fixation in unicellular cyanobacteria under turbulent and highly aerobic conditions
Authors: Krishnakumar S. , Gaudana Sandeep B. , Viswanathan Ganesh A. , Pakrasi Himadri B. , Wangikar Pramod P. 
Published: March 2013

AbstractNitrogen fixing cyanobacteria are being increasingly explored for nitrogenase‐dependent hydrogen production. Commercial success however will depend on the ability to grow these cultures at high cell densities. Photo‐limitation at high cell densities leads to hindered photoautotrophic growth while turbulent conditions, which simulate flashing light effect, can lead to oxygen toxicity to the nitrogenase enzyme. Cyanothece sp. strain ATCC 51142, a known hydrogen producer, is reported to grow and fix nitrogen under moderately oxic conditions in shake flasks. In this study, we explore the growth and nitrogen fixing potential of this organism under turbulent conditions with volumetric oxygen mass transfer coefficient (KLa) values that are up to 20‐times greater than in shake flasks. In a stirred vessel, the organism grows well in turbulent regime possibly due to a simulated flashing light effect with optimal growth at Reynolds number of approximately 35,000. A respiratory burst lasting for about 4 h creates anoxic conditions intracellularly with near saturating levels of dissolved oxygen in the extracellular medium. This is concomitant with complete exhaustion of intracellular glycogen storage and upregulation of nifH and nifX, the genes encoding proteins of the nitrogenase complex. Further, the rhythmic oscillations in exhaust gas CO2 and O2 profiles synchronize faithfully with those in biochemical parameters and gene expression thereby serving as an effective online monitoring tool. These results will have important implications in potential commercial success of nitrogenase‐dependent hydrogen production by cyanobacteria. Biotechnol. Bioeng. 2013; 110:2371–2379. © 2013 Wiley Periodicals, Inc.
Laser exposure of gold nanorods can increase neuronal cell outgrowth
Authors: Paviolo Chiara , Haycock John W. , Yong Jiawey , Yu Aimin , Stoddart Paul R. , McArthur Sally L. 
Published: March 2013

AbstractThe usage of gold nanoparticles (Au NPs) in biological applications has risen significantly over the last 10 years. With the wide variety of chemical and biological functionalization available and their distinctive optical properties, Au NPs are currently used in a range of biological applications including sensing, labeling, drug delivery, and imaging applications. Among the available particles, gold nanorods (Au NRs) are particularly useful because their optical absorption can be tuned across the visible to near infrared region. Here, we present a novel application of Au NRs associated with low power laser exposure of NG108‐15 neuronal cells. When cells were irradiated with a 780 nm laser, the average number of neurons with neurites increased. A similar stimulatory effect was observed for cells that were cultured with poly‐(4‐styrenesulfonic acid)‐coated and silica‐coated Au NRs. Furthermore, when the NG108‐15 cells were cultured with both bare and coated Au NRs and then irradiated with 1.2–7.5 W/cm2 at 780 nm, they showed a neurite length increase of up to 25 µm versus control. To the best of our knowledge, this effect has never been reported before. While the pathways of the stimulation is not yet clear, the data presented here demonstrates that it is linked to the absorption of light by the Au NRs. These initial results open up new opportunities for peripheral nerve regeneration treatments and for novel approaches to addressing central nervous system axons following spinal cord injury. Biotechnol. Bioeng. 2013; 110: 2277–2291. © 2013 Wiley Periodicals, Inc.
Radioactive seed localization for non-palpable breast cancer
Authors: Barentsz M W , van den Bosch M A A J , Veldhuis W B , van Diest P J , Pijnappel R M , Witkamp A J , Verkooijen H M 
Published: March 2013

Abstract

Background
Radioactive seed localization (RSL) is an alternative to wire localization for guiding surgical excision of non-palpable breast cancer. This review provides an overview of the available evidence on the accuracy of RSL in patients undergoing breast-conserving surgery.

Methods
PubMed, Embase and the Cochrane Library were searched systematically in January 2012 for studies that addressed localization of non-palpable breast cancer using an iodine-125-labelled seed. Studies were deemed eligible if they reported on the proportion of patients with tumour-positive margins after RSL, the proportion of patients needing re-excision after RSL, and procedural complications.

Results
Six studies reported data on RSL in 1611 patients with non-palpable breast lesions. Overall complete resection rates ranged from 73 to 96·7 per cent. Three studies included over 300 patients, and complete resection rates in these studies varied between 89·5 and 96·7 per cent. The risk of seed migration and failure of seed placement ranged from 0 to 0·6 per cent and 0 to 7·2 per cent respectively.

Conclusion
Available scientific evidence suggests that RSL is a safe and accurate technique for localization of non-palpable breast lesions.
Artificial Copper Enzymes for Asymmetric Diels–Alder Reactions
Authors: Deuss Peter J. , Popa Gina , Slawin Alexandra M. Z. , Laan Wouter , Kamer Paul C. J. 
Published: March 2013

AbstractThe development of artificial copper enzymes from sterol carrier protein type 2 like domain (SCP‐2L) for the use in asymmetric catalysis was explored. For this purpose, proteins were modified with various nitrogen donor ligands. Maleimide‐containing ligands were found most suitable for selective cysteine bio‐conjugation. Fluorescence spectroscopy was used to confirm copper binding to an introduced phenanthroline ligand, which was introduced in two unique cysteine containing SCP‐2L mutants. Copper adducts of several modified SCP‐2L templates were applied in asymmetric Diels–Alder reactions. A clear influence of both the protein environment and the introduced ligand was found in the asymmetric Diels–Alder reaction between azachalcone and cyclopentadiene. A promising enantioselectivity of 25 % ee was obtained by using SCP‐2L V83C modified with phenanthroline–maleimide ligand. Good endo selectivity was observed for SCP‐2L modified with the dipicolylamine‐based nitrogen donor ligand. These artificial metalloenzymes provide a suitable starting point for the implementation of various available techniques to optimise the performance of this system.
Efficient Total Synthesis of (S)‐Dihydroresorcylide, a Bioactive Twelve‐Membered Macrolide
Authors: Zhang Li , Ma Wenquan , Xu Lili , Deng Fei , Guo Yuewei 
Published: March 2013

AbstractThe efficient synthesis of (S)‐dihydroresorcylide (1a) along with trans‐resorcylide dimethyl ether (2b), was achieved in linear 9 steps from commercially available orcinol monohydrate (6) with esterification, carbonylation, and ring‐closing metathesis (RCM) as the key steps in the synthetic sequence.
Physicochemical Characterization of Acidiphilium sp. Biofilms
Authors: Malki Moustafa , Casado Santiago , López María Francisca , Caillard Renaud , Palomares F. Javier , Gago José A. Martín , Vaz‐Domínguez Cristina , Cuesta Angel , Amils Ricardo , Fernández Víctor M. , Velez Marisela , De Lacey Antonio L. , Olea David 
Published: March 2013

AbstractThe biofilm formation of a strain of the extremophile bacterium Acidiphilium sp., capable of donating electrons directly to electrodes, was studied by different surface characterization techniques. We develop a method that allows the simultaneous study of bacterial biofilms by means of fluorescence microscopy and atomic force microscopy (AFM), in which transparent graphitic flakes deposited on a glass substrate are used as a support for the biofilm. The majority of the cells present on the surface were viable, and the growth of the biofilms over time showed a critical increase of the extracellular polymeric substances (EPS) as well as the formation of nanosized particles inside the biofilm. Also, the presence of Fe in Acidiphilium biofilms was determined by X‐ray photoelectron spectroscopy (XPS), whereas surface‐enhanced infrared absorption spectroscopy indicated the presence of redox‐active proteins.
The Gelling Ability of Some Diimidazolium Salts: Effect of Isomeric Substitution of the Cation and Anion
Authors: D'Anna Francesca , Vitale Paola , Ferrante Francesco , Marullo Salvatore , Noto Renato 
Published: March 2013

AbstractThe gelling ability of some geminal imidazolium salts was investigated both in organic solvents and in water solution. Organic salts differing either in the cation or anion structure were taken into account. In particular, the effects on the gel‐phase formation of isomeric substitution on the cation or anion as well as of the use of mono‐ or dianions were evaluated. As far as the cation structure is concerned, isomeric cations, such as 3,3′‐di‐n‐octyl‐1,1′‐(1,4‐phenylenedimethylene)diimidazolium and 3,3′‐di‐n‐octyl‐1,1′‐(1,3‐phenylenedimethylene)diimidazolium, were used. On the other hand, in addition to the bromide anion, isomeric dianions, such as the 1,5‐ and 2,6‐naphthalenedisulfonate anions, were also examined. After preliminary gelation tests, different factors affecting the obtained gel phases, such as the nature of the solvent, organogelator concentrations, and action of external stimuli, were analyzed. The gel‐phase formation was also studied as a function of time, by using resonance light scattering measurements. Gel morphologies were analyzed by scanning electron microscopy. To further support the understanding of the different behavior shown by the isomeric cations, some representative ion pairs were analyzed by DFT‐based investigations. The collected data underline the significant role played by isomeric substitution of both cation and anion structures in determining the gelling capability of the investigated salts, as well as the properties of the gel phases. Finally, DFT investigations were helpful in the identification of the structural features affecting the self‐assembly.
Electricity Storage in Biofuels: Selective Electrocatalytic Reduction of Levulinic Acid to Valeric Acid or γ‐Valerolactone
Authors: Xin Le , Zhang Zhiyong , Qi Ji , Chadderdon David J. , Qiu Yang , Warsko Kayla M. , Li Wenzhen 
Published: March 2013

AbstractHerein, we report an effective approach to electricity storage in biofuels by selective electrocatalytic reduction of levulinic acid (LA) to high‐energy‐density valeric acid (VA) or γ‐valerolactone (gVL) on a non‐precious Pb electrode in a single‐polymer electrolyte membrane electrocatalytic (flow) cell reactor with a very high yield of VA (>90 %), a high Faradaic efficiency (>86 %), promising electricity storage efficiency (70.8 %), and a low electricity consumption (1.5 kWh LVA−1). The applied potential and electrolyte pH can be used to accurately control the reduction products: lower overpotentials favor the production of gVL, whereas higher overpotentials facilitate the formation of VA. A selectivity of 95 % to VA in acidic electrolyte (pH 0) and 100 % selectivity to gVL in neutral electrolyte (pH 7.5) are obtained. The effect of the molecular structure on the electrocatalytic reduction of ketone and aldehyde groups of biomass compounds was investigated. Whereas LA can be fully electroreduced to VA though a four‐electron transfer, the CO groups are only electroreduced to OH by a two‐electron‐transfer process when glyoxylic acid and pyruvic acid serve as feedstocks.
Lipase‐Catalyzed (Trans)esterification of 5‐Hydroxy‐ methylfurfural and Separation from HMF Esters using Deep‐Eutectic Solvents
Authors: Krystof Monika , Pérez‐Sánchez María , Domínguez de María Pablo 
Published: March 2013

Abstract5‐Hydroxymethylfurfural (HMF) is a valuable biomass‐derived building block. Among possible HMF valorization products, a broad range of HMF esters can be synthesized. These HMF esters have found some promising applications, such as monomers, fuels, additives, surfactants, and fungicides, and thus several catalytic approaches for HMF (trans)esterifications have been reported. The intrinsic reactivity of HMF is challenging, forcing the use of mild reaction conditions to avoid by‐product formation. This paper explores the lipase‐catalyzed (trans)esterification of HMF with different acyl donors (carboxylic acids and methyl‐ and ethyl esters) mostly in solvent‐free conditions. The results demonstrate that lipases may be promising alternatives for the synthesis of HMF esters—with high productivities and reactions at high substrate loadings—provided that robust systems for lipase immobilization are applied to assure an adequate reusability of the enzymes. Once (trans)esterifications have been conducted, the separation of unreacted HMF and HMF esters is performed by using deep‐eutectic solvents (DES) as separation agents. DES are able to dissolve hydrogen‐bond donors (e.g., HMF), whereas non‐hydrogen‐bond donors (in this case HMF esters) form a second phase. By using this approach, high ester purities (>99 %) and efficiencies (up to >90 % HMF ester recovery) in separations were obtained by using choline chloride‐based DES.