bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kovalente Proteinmarkierung durch enzymatische Phosphocholinierung
Authors: Heller Katharina , Ochtrop Philipp , Albers Michael F. , Zauner Florian B. , Itzen Aymelt , Hedberg Christian 
Published: July 2015

AbstractWir präsentieren eine neue Methode zur Proteinmarkierung, die auf der kovalenten enzymatischen Phosphocholinierung einer spezifischen Octapeptidsequenz intakter Proteine beruht. Das Enzym AnkX aus Legionellen wurde etabliert, um funktionalisierte Phosphocholingruppen aus synthetischen CDP‐Cholin‐Derivaten auf N‐ und C‐Termini, sowie interne Schleifenregionen zu übertragen. Zudem kann die kovalente Modifikation durch das Legionellen‐Enzym Lem3 hydrolytisch entfernt werden. Lediglich eine 8 Aminosäuren kurze Peptidsequenz und eine kleine Verbindungsgruppe (PEG‐Phosphocholin) sind für die effiziente Proteinmarkierung erforderlich.
1,4‐Diketones from Cross‐Conjugated Dienones: Potassium Permanganate‐Interrupted Nazarov Reaction
Authors: Kwon Yonghoon , Schatz Devon J. , West Frederick G. 
Published: July 2015

AbstractA domino potassium permanganate‐interrupted Nazarov reaction to yield syn‐2,3‐disubstituted 1,4‐diketones via a decarbonylative cleavage of the Nazarov oxyallyl intermediate, believed to be without precedent, is presented. This process allows syn substituents to be established stereospecifically on the 2‐carbon bridge connecting the ketone carbonyl carbons, and the formation of one carbon–carbon and two carbon–oxygen bonds. Two carbon–carbon bonds are cleaved in this process.
Plasticized poly(vinyl chloride) composites: Influence of different nanofillers as antimigration agents
Authors: Gholami Abed , Hajian Morteza , Rafiemanzelat Fatemeh , Zanjanijam Ali Reza 
Published: July 2015

ABSTRACTIn this study, plasticized poly(vinyl chloride) (PVC) composites with different nanofillers, including single‐walled carbon nanotubes (SWCNTs), organoclay, TiO2, and ZnO nanoparticles, were prepared, and their effects on plasticizer migration were investigated. Scanning electron micrographs revealed the dispersion quality of the nanofillers in the polymer matrix. It had a significant influence on the performance of the nanofillers in the process of plasticizer migration. Migration and exudation tests showed that the nanofillers could efficiently hinder plasticizer migration. On the basis of these results, we concluded that carbon nanotubes were the best antimigration agent in the plasticized system. This was ascribed to the high aspect ratio of the SWCNTs and the good interactions between them and the plasticizer. Also, TiO2 nanoparticles showed a better performance compared to the ZnO nanoparticles. This was due to the more homogeneous dispersion of the TiO2 in the polymer matrix and the higher surface area of the particles. The differential scanning calorimetry thermograms were in good agreement with the migration tests. The lowest change in the glass‐transition temperature was observed for the composite filled with SWCNTs. This indicated that a lower amount of the plasticizer migrated from PVC. The thermogravimetric analysis curves showed that the incorporation of the nanofillers improved the thermal stability of the PVC. The results could be useful for determining the efficiency of plasticized PVC in applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42559.
Production of sulfonated polyetheretherketone/polypropylene fibers for photoactive textiles
Authors: Mylläri Ville , Fatarella Enrico , Ruzzante Marco , Pogni Rebecca , Baratto Maria Camilla , Skrifvars Mikael , Syrjälä Seppo , Järvelä Pentti 
Published: July 2015

ABSTRACTNew photocatalytic fibers made of sulfonated polyetheretherketone (SPEEK)/polypropylene (PP) are melt compounded and melt spun, first on laboratory scale and then on a semi‐industrial scale. Fiber spinnability is optimized and the fibers are characterized using mechanical testing, electron paramagnetic resonance (EPR) spectroscopy, and scanning electron microscopy (SEM). According to the results, the fiber spinnability remains at a good level up to 10 wt % SPEEK concentration. Optimal processing temperature is 200°C due to the thermal degradation at higher temperatures. EPR measurements show good and long‐lasting photoactivity after the initial irradiation but also decay in the radical intensity during several irradiation cycles. Mechanical tenacity of the SPEEK/PP 5:95 fiber is approximately 20% lower than for otherwise similar PP fiber. The fiber is a potential alternative to compete against TiO2‐based products but more research needs to be done to verify the real‐life performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42595.
A high temperature polymer of phthalonitrile‐substituted phosphazene with low melting point and good thermal stability
Authors: Zhao Fenghua , Liu Ruojin , Yu Xiaoyan , Naito Kimiyoshi , Qu Xiongwei , Zhang Qingxin 
Published: July 2015

ABSTRACTA phthalonitrile‐substituted phosphonitrilic monomer has been synthesized from phosphonitrilic chloride trimer and then polymerized with addition of 4‐(hydroxylphenoxy)phthalonitrile (HPPN). The chemical structures of the phosphonitrilic monomer and polymer were characterized by Fourier Transform Infrared spectroscopy (FT‐IR) and proton Nuclear Magnetic Resonance spectroscopy (1H NMR). Curing behaviors and thermal stabilities of the polymer were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Analysis showed that the monomer has large processing temperature window and good thermal stability. Apparent activation energy, initial curing temperature (Ti), curing temperature (Tp), and termination curing temperature (Tf) of the phosphonitrilic polymer were explored. Dynamic mechanical analysis (DMA), glass transition temperature (Tg) were studied, and limiting oxygen index (LOI) were estimated from the van Krevelen equation, which indicates the polymer process high modulus and good flame retardance. Micro‐scale combustion calorimetry (MCC) was also used for evaluating the flammability of the polymers. Postcuring effects were explored, showing excellent thermal and mechanical properties with postcuring. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42606.
Investigation on morphology and properties of melt compounded polyoxymethylene/carbon nanotube composites
Authors: Lin Leyu , Schlarb Alois K. 
Published: July 2015

ABSTRACTPolyoxymethylene nanocomposites containing different contents of carbon nanotubes were produced by a two‐step melt compounding process using a twin‐screw extruder. The dispersion quality, thermal and mechanical properties, and the creep as well as the tribological behaviors of the nanocomposites were investigated. Morphological investigations show that the masterbatch dilution process significantly improves the dispersion quality of carbon nanotubes within polyoxymethylene matrix, and as a consequence, enhanced mechanical properties and creep resistance are gained. Furthermore, to predict the long‐term property based on the short‐term experimental data, the time–temperature superposition principle and Findley model were used. Master curves with extended time scale are constructed using time–temperature superposition principle to horizontally shift the short‐term experimental data. The simulated results confirm the reinforced creep resistance by incorporation of the carbon nanotubes into the polymer matrix even at extended long time scale. By contrast, the tribological performance of polyoxymethylene was remarkably impaired after adding carbon nanotubes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42639.
Untersuchungsstrategie zur Bewertung der Langzeitstabilität von Dehnungsmessstreifen
Authors: Herrmann Ralf , Stockmann Martin , Marx Steffen 
Published: July 2015

AbstractIm Bauwerksmonitoring werden neben Temperaturen und Verschiebungen meist Dehnungen gemessen. Dies dient u. a. dazu, den Ausnutzungsgrad und die Betriebsfestigkeit zu beurteilen. Ein sehr gebräuchliches Verfahren zur Bestimmung von Dehnungen an und in Bauteilen ist die Messung mit Dehnungsmessstreifen (DMS). Für die Beurteilung der Langzeitstabilität von Dehnungsmessstreifen wird im Folgenden eine Klimaprüfung vorgestellt, die eine beschleunigte Beanspruchungseinwirkung durch Temperatur‐ und Feuchteschwankungen simuliert. Dieser sich wiederholende Zyklus besteht aus vier Phasen, die insgesamt 240 h umfassen und dabei unterschiedliche Kombinationen von Temperatur und Luftfeuchtigkeit bis hin zu Frost‐Tau‐Wechseln beinhalten. Anhand von Ergebnissen aus durchgeführten Langzeituntersuchungen über einen Zeitraum von 85 d werden Kenngrößen zur Charakterisierung der Langzeitstabilität von Dehnungsmessstreifen abgeleitet. Die Messergebnisse zeigen Unterschiede in der Nullpunktdrift zwischen den einzelnen Typen von Dehnungsmessstreifen und welche Bedeutung der Auswahl und dem Schutz von Dehnungsmessstreifen beigemessen werden muss.Test strategy for evaluation of strain gauge long term stabilityIn the field of structural health monitoring the measuring of strain is prevalent beside temperature and displacement. The strain is used to determine the utilization rate and to estimate the fatigue strength of a structure. A very common measurement method for strains at and in components is the usage of strain gauges. Further, a climate cycle for analysis of long term stability of strain gauges is introduced, that simulates an accelerated temperature and humidity stress. This cycle consists of four phases, which lasts 240 h and covers different combinations of temperature and humidity conditions up to freezing and thawing. The results of a 85 d lasting long term test are presented and used to describe characteristic values for long term stability of strain gauges. The measurement results show significant differences for the strain gauge types in the zero point drift and underline the role of correct choice and protection to achieve reliable strain measurements.
Die Autobahn‐Talbrücke bei Rüdersdorf
Authors: Braun Michael 
Published: July 2015

AbstractIm Sommer 1937 ist am Berliner Autobahn‐Ring die sogenannte Osttangente in den Betrieb gegangen. Damit wurde auch eine der später bekanntesten Brücken im gesamten deutschen Autobahnnetz erstmals befahren. Verstörend muss noch heute wirken, dass diese Brücke bis zu ihrer nahezu kompletten Erneuerung im kollektiven Gedächtnis leider sehr viel weniger wegen ihrer ausgezeichneten ästhetischen Wirkung, denn wegen der einstmals an ihr aufgetretenen Schäden hinterlegt ist. Konsequenterweise sind neben einem enormen Konvolut zu den Schäden kaum neutrale Veröffentlichungen zu der Brücke zu finden [1, 2].The highway bridge near RüdersdorfIn the summer of 1937 the eastern part of the Berlin highway circle was opened to traffic. Thus one of the later on best known bridges was put into use. It seems to be a little bit confusing, that a majority won't remember the bridge because of its size, but rather of its disruption. Consequentially you can find very few neutral papers about this structure.
Verlängerung und Grundinstandsetzung der Nordkammer Schleuse Kersdorf
Authors: Thumernicht Sven , Lindlar Hans‐Gerd , Jacob Karsten 
Published: July 2015

AbstractMit dem Ziel, die wichtigen Industrie‐ und Gewerbestandorte entlang der Spree‐Oder‐Wasserstraße (SOW) weiter nachhaltig an das transeuropäische Binnenwasserstraßennetz anzubinden, führt der Bund seit dem Jahr 2005 Grundinstandsetzungen für die Schleusen am Oder‐Spree‐Kanal aus. Diese beinhalten unter anderem eine Erhöhung der nutzbaren Kammerlänge jeweils von 57 m auf 115 m. Die über 100 Jahre alte Nordkammer der Schleuse Kersdorf wurde grundhaft instand gesetzt und in Spundwandbauweise verlängert. Die vorhandene Kammerbreite von 9,80 m ist im verlängerten Kammerteil beibehalten worden. Mit dem vorliegenden Bericht soll ein Einblick in die Planung, Prüfung und Realisierung des Vorhabens gegeben werden. In diesem Zusammenhang wird auf Besonderheiten eingegangen, die einerseits hohe Anforderungen an Bauherr und Ausführende stellen, andererseits aber typisch für Maßnahmen zur Erhaltung der Infrastruktur im Bestand sind. Im Auftrag des Wasserstraßen‐Neubauamtes Berlin wurde das Bauvorhaben 2013 fertiggestellt und erforderte Investitionskosten von ca. 14 Mio. €.Elongation and restoration of the Nordkammer Schleuse KersdorfSince 2005 the federal government is realising reinstatement work on the locks of the Oder‐Spree‐Channel to provide a sustainable connection for the most important industrial and commercial locations along the Spree‐Oder‐Waterway (SOW) to the trans‐european inland waterway. Part of this project is an increase of the usable chamber length each from 57 m up to 115 m. The more than 100 years old “Nordkammer Schleuse Kersdorf” (northern part of the lock in Kersdorf) has been reconstructed and elongated with a sheet piling construction. In this process the goal to keep the existing width of the chamber at 9.8 m throughout the new length of the construction was achieved. The given report should provide insights of the planning, testing and realisation of the construction project. Hence, special features will be outlined which challenge the building‐owner as well as the contractor, by being typical for actions in the preservation of infrastructure in existing constructions. This project was completed in 2013 and required overall costs in the amount of approximately 14 million euros. Principal was the Wasserstraßen‐Neubauamt Berlin.
Brücken aus der Sicht des Wasserbauers
Authors: Pohl Reinhard 
Published: July 2015

AbstractBei Hochwasserereignissen konnte verschiedentlich festgestellt werden, dass Brücken über Wasserläufen den Abfluss behindern und Überschwemmungen angrenzender Gebiete fördern oder verursachen. Im vorliegenden Beitrag werden wichtige Grundsätze der konstruktiven Ausbildung von Brücken aus wasserbaulicher Sicht dargestellt, die notwendig sind, um gebrauchstaugliche und dauerhafte Bauwerke zu errichten.Bridges from the viewpoint of a hydraulic engineerDuring river floods it has often been observed that bridges could obstruct the flow of the water and enhance or cause inundations of the adjacent areas. In this paper some significant principles of the constructional design of bridges are discussed from a hydraulic engineer's viewpoint to ensure the erection of useable and durable structures.
Erweitertes Modell zur Berechnung der Rissbreite
Authors: Empelmann Martin , Krakowski Waldemar 
Published: July 2015

AbstractDie Beschränkung der auftretenden Rissbreiten ist bei Stahlbetonbauteilen eine maßgebliche Bemessungsaufgabe zur Sicherstellung der Gebrauchstauglichkeit und Dauerhaftigkeit. Im vorliegenden Beitrag wird ein neues, praxisgerechtes Modell zur Berechnung der charakteristischen Rissbreite vorgestellt, welches auf allgemeingültigen mechanischen Ableitungen aufbaut und den charakteristischen Rissabstand sowie die zugehörigen charakteristischen Dehnungen über eine konsistente, verbundorientierte Methodik bestimmt. Die Bestimmungsgleichungen wurden in einer umfangreichen Parameterstudie ermittelt, sodass das neue Berechnungsmodell den Ansatz des EC2/NA [2] bzw. der DIN 1045‐1 [10] im Hinblick auf verbundspezifische und rissmechanische Zusammenhänge verbessert und den Anwendungsbereich in der praktischen Anwendung erweitert.Extended model to calculate the crack widthThe calculation of the crack widths is a main task within the design of reinforced concrete structures in order to secure the serviceability and the durability. In the following a new, practical model for the calculation of the characteristic crack width is presented, which is based on general mechanical relationships and determines the characteristic crack spacing and the associated characteristic strains with a consistent, bond‐oriented methodology. The calculation formulas were determined in an extensive parameter study so that the new calculation model improves the approach of the EC2/NA [2] or DIN 1045‐1 [10] in terms of bond specifics and crack mechanics and extends the application range in the practical use.
Schubversuche an Stahlbetonbalken unterschiedlicher M/V‐Kombinationen
Authors: Tue Nguyen Viet , Ehmann Rainer , Tung Nguyen Duc 
Published: July 2015

AbstractDer vorliegende Aufsatz berichtet über experimentelle Untersuchungen zum Einfluss des statischen Systems und der Belastungsart auf das Querkraftverhalten von Biegebauteilen ohne Querkraftbewehrung. Zehn rechteckige Stahlbetonbalken mit drei statischen Systemen und zwei Belastungsarten wurden hierbei getestet, wodurch nahezu alle in der Praxis möglichen M/V‐Kombinationen erfasst werden konnten. Die Ergebnisse zeigen erhebliche Unterschiede in der Querkrafttragfähigkeit von Schubfeldern unterschiedlicher M/V‐Kombinationen. Die Querkrafttragfähigkeit von Einfeldbalken unter Gleichlast ist höher als jene von vergleichbaren Balken unter Einzellast. Ferner ist die Querkrafttragfähigkeit von Krag‐ und Mittelstützen von Durchlaufbalken unter Gleichlast deutlich höher als die Querkrafttragfähigkeit von Einfeldbalken. Im Allgemeinen kann mit den Versuchsergebnissen festgestellt werden, dass die zugehörige Biegebeanspruchung die Querkrafttragfähigkeit eines Bauteils positiv beeinflusst. Weiterhin spielt das Rissbild infolge Biegung eine entscheidende Rolle für die Querkrafttragfähigkeit bei schubschlanken Stahlbetonbauteilen.Shear tests on reinforced concrete beams with different M/V‐combinationsThis paper presents an experimental investigation on the effect of structural system and load configuration on the shear behavior of flexural reinforced concrete (RC) members without shear reinforcement. A total of ten rectangular beams with three structural systems and two load configurations were tested. With the chosen test set‐up, almost all M/V‐combinations commonly encountered in practice can be investigated. The test results indicate significant differences of the shear capacity of members with different M/V‐combinations. The shear capacity of the simply supported beam under a uniform load is higher than that of similar beams under a concentrated load. Moreover, the shear capacity of the cantilever and continuous beams under uniform load is significantly higher than that of simply supported beams. Generally, it can be concluded that the co‐existing flexural action has a positive influence on the shear resistance of a RC member without shear reinforcement. Furthermore, the flexural crack pattern plays an important role in the shear resistance of slender RC members.
qPCR for second year undergraduates: A short, structured inquiry to illustrate differential gene expression
Authors: McCauslin Christine Seitz , Gunn Kathryn Elaine , Pirone Dana , Staiger Jennifer 
Published: July 2015

AbstractWe describe a structured inquiry laboratory exercise that examines transcriptional regulation of the NOS2 gene under conditions that simulate the inflammatory response in macrophages. Using quantitative PCR and the comparative CT method, students are able determine whether transcriptional activation of NOS2 occurs and to what degree. The exercise is aimed at second year undergraduates who possess basic knowledge of gene expression events. It requires only 4–5 hr of dedicated laboratory time and focuses on use of the primary literature, data analysis, and interpretation. Importantly, this exercise provides a mechanism to introduce the concept of differential gene expression and provides a starting point for development of more complex guided or open inquiry projects for students moving into upper level molecular biology, immunology, and biochemistry course work. © 2015 by the International Union of Biochemistry and Molecular Biology, 43(4):273–282, 2015.
Microautophagy involves programmed cell semi‐death of sieve elements in developing caryopsis of Triticum aestivum L.
Authors: Yang Wenli , Cai Jingtong , Zhou Zhuqing , Zhou Guangsheng , Mei Fangzhu , Wang Likai 
Published: July 2015

AbstractDifferentiation of sieve elements (SEs) involves programmed cell semi‐death, in which a small amount of organelles is retained. However, the mechanisms by which a large amount of SE cytoplasm is degraded and the specific proteases involved are not clear. In this study, we confirmed that the degradation of cytoplasm outside of the vacuole was mediated by microautophagy of the vacuole, and that the tonoplast selectively fused with the plasma membrane after most of the cytoplasm in the vacuoles was degraded. The integration of space enclosed a small amount of cytoplasm. Therefore, that fraction of the cytoplasm was preserved. At the same time, the cytosol was weakly acidic during membrane fusion because part of the tonoplast was ruptured. We also demonstrated that wheat aspartic protease (WAP1) and proteases including cathepsin B activity (PICA) were involved in programmed cell semi‐death of SEs. PICA showed strongest activity before mass of the cytoplasm was degraded, which might contribute toward SE stability. We found that WAP1 mainly degraded the cytoplasm. Therefore, programmed cell semi‐death of SEs might result from the joint action of vacuoles and multiple proteases.
Computational Investigation on the Mechanism of Amide Bond Formation by using Phosphine‐Based Redox Catalysis
Authors: Di Santo Emanuela , Alberto Marta E. , Russo Nino , Toscano Marirosa 
Published: July 2015

AbstractA density functional theory investigation of the PPh3‐catalyzed formation of amides from benzoic acid was explored. The results confirm the involvement of a phosphonium intermediate that is crucial to activate the carboxylate for nucleophilic acyl substitution.
Influence of Tortuous Geometry on the Hydrodynamic Characteristics of Laminar Flow in Microchannels
Authors: Dai Zhenhui , Fletcher David F. , Haynes Brian S. 
Published: July 2015

AbstractFlow visualizations are performed to study the hydrodynamic characteristics of laminar flow in tortuous microchannels for a wide range of Reynolds numbers. The detailed flow patterns in wavy channels are identified and found to be greatly affected by geometrical parameters. In wavy channels, steady flow exists at low Reynolds numbers, but above a critical number unsteady flow develops. The critical Reynolds number is found to depend on the characteristics of the channel path. Recirculation zones form immediately after the inner corners of the sharp bends, with their size and magnitude of the recirculation velocity increasing with higher Reynolds numbers. Large fluctuations in recirculation zone locations highlight the importance of these flow features in the development of transient flow. The flow behaviors play very important roles in determining the pressure drop in wavy channels relative to straight channels.
Measuring Cumulative Exposure to Oxygen with a Diphenylphosphine–Alkyl Naphthaleneimide Luminescence Turn‐On Dyad
Authors: Shritz Rozalia , Shapira Reut , Borzin Elena , Tumanskii Boris , Reichstein Werner , Meichner Christoph , Schwaiger Florian , Reichstein Paul M. , Kreyenschmidt Judith , Haarer Dietrich , Kador Lothar , Eichen Yoav 
Published: July 2015

Abstract2‐(2‐Diphenylphosphanylethyl)benzo[de]isoquinoline‐1,3‐dione is a poorly luminescent, photoinduced‐electron‐transfer (PET) dyad, NI‐(Ph)2P:, in which the luminescence of its naphthaleneimide (NI) part is quenched by the lone‐pair electrons of the phosphorus atom of the (Ph)2P: group. Photoinduced oxidation of (Ph)2P: to (Ph)2PO by molecular oxygen regenerates the luminescence of the NI group, because the oxidized form (Ph)2PO does not serve as a quencher to the NI system. The oxidation of (Ph)2P: is thermally inaccessible. The NI‐(Ph)2P: system was applied to monitoring the cumulative exposure of oxidation‐sensitive goods to molecular oxygen. The major advantage of this new PET system is that it reacts with oxygen only via the photoinduced channel, which offers the flexibility of monitoring the cumulative exposure to oxygen in different time periods, simply by varying the sampling frequency. Electronic‐energy calculations and optical spectroscopic data revealed that the luminescence turn‐on upon reaction with molecular oxygen relies on a PET mechanism.