bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integriertes Entwerfen im digitalen Prozess
Authors: Knippers Jan 
Published: April 2014

AbstractComputerbasierte Planungs‐, Simulations‐ und Fertigungsverfahren sind seit Jahrzehnten unverzichtbare Hilfsmittel beim Planen und Bauen. Gegenwärtige Entwicklungen zielen auf die Verknüpfung von bisher isolierten Softwarekomponenten zum einen auf die horizontale Integration von verschiedenen Informationen der Planungsbeteiligten in Gebäudedatenmodellen (Building Information Modeling, kurz: BIM) und zum anderen vertikal entlang der gesamten Prozesskette vom frühen Entwurf bis zur Ausführung auf der Baustelle und der Bewirtschaftung der Gebäude. Ziel ist dabei die Steigerung der Effizienz und der Sicherheit von Planungs‐ und Bauabläufen. Darüber hinaus hat dies aber auch tief greifende Auswirkungen auf die Planungskultur: Es verändert sich nicht nur die interdisziplinäre Kommunikation zwischen den Beteiligten, sondern auch die Rolle und die Aufgaben von Architekten und Ingenieuren im Prozess des Planens und Bauens.Integrative design in the digital processComputational design, simulation and fabrication methods have been an indispensable means of design and construction for decades. Recent efforts are focused on linking previously isolated components: on the one hand, horizontally through the integration of different information of the various parties involved in consistent data models (Building Information Modeling, short: BIM), on the other hand, vertically along the entire process chain, from the early stages of design to the installation on site and management of the facilities. The aim is to strengthen the efficiency and reliability of design and construction processes. In addition this will lead to a profound change in the culture of design that will not only affect the interdisciplinary communication, but also the role of architects and engineers in the entire process of design and construction.
Ermüdungsversuche an Stahlbetonfertigteilen für Lärmschutzwände an Eisenbahn‐Hochgeschwindigkeitsstrecken
Authors: Keuser Manfred , Hiller Eugen , Lenner Roman 
Published: April 2014

AbstractAngesichts der dichten Besiedlung kommt dem Schallschutz an Verkehrswegen in Deutschland eine große Bedeutung zu. Insbesondere an Eisenbahnstrecken kommen Lärmschutzwände aus Stahlbetonfertigteilen zum Einsatz. Bei Hochgeschwindigkeitsverkehr führt die Belastung aus Zugvorbeifahrt zu Schwingungen der Wände, sodass die Ermüdungsfestigkeit nachgewiesen werden muss. Im Labor des Instituts für Konstruktiven Ingenieurbau der Universität der Bundeswehr wurden hierzu in den vergangenen Jahren zahlreiche Versuche mit zyklischer Belastung durchgeführt. Dabei wurde dem Auflagerbereich, angesichts der sehr kleinen Auflagerbreite, besondere Beachtung geschenkt.Reinforced Concrete Precast Panels as Noise Protection along High Speed Rail TracksThe noise protection along traffic routes has large importance in Germany due to the high density of population. Reinforced concrete panels as noise protection walls are often used especially along railroad tracks. The loading due to high‐speed trains induces oscillation of the walls and the fatigue, therefore, has to be investigated. During the last years, the Laboratory of the Institute of Structural Engineering at the University of the German Armed Forces in Munich performed a large number of tests involving cyclical loading. The particular area of interest was the relatively narrow support.
Die zerstörungsfreie Untersuchung von Durchstanzbewehrung in Flachdecken
Authors: Hugenschmidt Johannes , Fischer Andreas , Schiavi Lucio 
Published: April 2014

AbstractMittels Radaruntersuchungen werden Betondeckenbereiche einer Fläche von 2 × 0,9 m2 in Stützennähe in ausgewählten Einstellhallen zerstörungsfrei mit dem Ziel untersucht, typische Bewehrungselemente zur Erhöhung des Durchstanzwiderstands zu erkennen. Im Untersuchungsergebnis zeigte sich, dass diese Elemente, wie z.B. Bewehrungsstäbe, Stahlpilze oder Dübelleisten, mit hoher Wahrscheinlichkeit identifiziert werden können. Die Messdaten liefern für die meisten untersuchten Elementtypen spezifische, reproduzierbare Datenmuster. Mithilfe von Radaruntersuchungen ist es deshalb möglich, auf nicht dokumentierte Bewehrungselemente im Bauwerk zu schließen. Die Bauingenieure können so den Durchstanzwiderstand von Flachdecken im Bereich ihrer Stützen besser beurteilen. Das eröffnet Prüfmöglichkeiten zur Durchstanzproblematik in Bezug auf die Einhaltung technisch verbindlicher Normen sowie zur Untersuchung von Bauschäden oder deren Prophylaxe.Non‐destructive inspection of punching shear reinforcement in concrete flat slabsIn selected car parks, ground penetrating radar (GPR) surveys were carried out on ceiling areas in the vicinity of piles. The areas inspected were 0.9 m × 2.0 m each. The aim of the surveys was the detection Punching shear reinforcement (PSR). It was shown that several types of PSR can be detected reliably. The acquired GPR data show distinctive reflection patterns for most types of PSR. It is therefore possible to detect punching shear reinforcement in cases where appropriate documentation of the construction details is missing. Thus, GPR surveys can provide information relevant for the engineer for assessing the safety of buildings. This facilitates testing options related to the punching problem. Objects can be tested for compliance with existing standards, for the evaluation of structural damage or for prevention.
Schrägseilbedämpfung mit echtzeitgeregelten MR‐Dämpfern
Authors: Weber Felix , Distl Hans 
Published: April 2014

AbstractSchrägseile neigen wegen ihrer kleinen Dämpfung von 0,1%–0,15% zu windinduzierten Schwingungen. Da sich Windbedingungen ändern, sind sowohl Schwingamplitude als auch Schwingfrequenz unbekannt. Daher muss ein Seildämpfungssystem die Seile unabhängig von deren Amplitude und Frequenz gleich effizient bedämpfen. Dieser Aufsatz zeigt, wie diese Anforderung mittels echtzeitgeregelter magnetorheologischer Dämpfer erfüllt werden kann. Die Effizienz des adaptiven Seildämpfungssystems ist experimentell validiert und dessen Umsetzung auf den weltgrößten Schrägseilbrücken, der Sutong‐Brücke in China und der Russky‐Brücke in Russland, beschrieben.Stay Cable Damping by Real‐Time Controlled MR DampersStay cables are prone to wind‐induced vibrations due to their low inherent damping of 0,1%–0,15%. Since wind conditions vary over time, vibration amplitudes and frequencies are unknown. Consequently, cable damping systems must generate amplitude and frequency independent cable damping. It is described how this requirement can be fulfilled by real‐time controlled magnetorheological dampers. The efficiency of the adaptive cable damping system is experimentally validated and its implementation on the world largest stay cable bridges, the Sutong Bridge in China and the Russky Bridge in Russia, is described.
Research experiences and mentoring practices in selected east asian graduate programs: Predictors of research productivity among doctoral students in molecular biology
Authors: Ynalvez Ruby , Garza‐Gongora Claudia , Ynalvez Marcus Antonius , Hara Noriko 
Published: April 2014

AbstractAlthough doctoral mentors recognize the benefits of providing quality advisement and close guidance, those of sharing project management responsibilities with mentees are still not well recognized. We observed that mentees, who have the opportunity to co‐manage projects, generate more written output. Here we examine the link between research productivity, doctoral mentoring practices (DMP), and doctoral research experiences (DRE) of mentees in programs in the non‐West. Inspired by previous findings that early career productivity is a strong predictor of later productivity, we examine the research productivity of 210 molecular biology doctoral students in selected programs in Japan, Singapore, and Taiwan. Using principal component (PC) analysis, we derive two sets of PCs: one set from 15 DMP and another set from 16 DRE items. We model research productivity using Poisson and negative‐binomial regression models with these sets as predictors. Our findings suggest a need to re‐think extant practices and to allocate resources toward professional career development in training future scientists. We contend that doctoral science training must not only be an occasion for future scientists to learn scientific and technical skills, but it must also be the opportunity to experience, to acquire, and to hone research management skills. © 2014 by The International Union of Biochemistry and Molecular Biology, 42(4):305–322, 2014.
Enhancing the Efficiency and Regioselectivity of P450 Oxidation Catalysts by Unnatural Amino Acid Mutagenesis
Authors: Kolev Joshua N. , Zaengle Jacqueline M. , Ravikumar Rajesh , Fasan Rudi 
Published: April 2014

AbstractThe development of effective strategies for modulating the reactivity and selectivity of cytochrome P450 enzymes represents a key step toward expediting the use of these biocatalysts for synthetic applications. We have investigated the potential of unnatural amino acid mutagenesis to aid efforts in this direction. Four unnatural amino acids with diverse aromatic side chains were incorporated at 11 active‐site positions of a substrate‐promiscuous CYP102A1 variant. The resulting “uP450s” were then tested for their catalytic activity and regioselectivity in the oxidation of two representative substrates: a small‐molecule drug and a natural product. Large shifts in regioselectivity resulted from these single mutations, and in particular, for para‐acetyl‐Phe substitutions at positions close to the heme cofactor. Screening this mini library of uP450s enabled us to identify P450 catalysts for the selective hydroxylation of four aliphatic positions in the target substrates, including a C(sp3)H site not oxidized by the parent enzyme. Furthermore, we discovered a general activity‐enhancing effect of active‐site substitutions involving the unnatural amino acid para‐amino‐Phe, which resulted in P450 catalysts capable of supporting the highest total turnover number reported to date on a complex molecule (34 650). The functional changes induced by the unnatural amino acids could not be reproduced by any of the 20 natural amino acids. This study thus demonstrates that unnatural amino acid mutagenesis constitutes a promising new strategy for improving the catalytic activity and regioselectivity of P450 oxidation catalysts.
Converting Aspartase into a β‐Amino Acid Lyase by Cluster Screening
Authors: Vogel Andreas , Schmiedel Ramona , Hofmann Ute , Gruber Karl , Zangger Klaus 
Published: April 2014

AbstractAspartase, despite being one of the most specific enzymes known, shows potential for application in β‐amino acid synthesis. The substrate binding pocket of AspB from Bacillus sp. YM55‐1 was reshaped by enzyme engineering to accommodate crotonic acid. The mutant enzyme BSASP‐C6 yielded enantiopure (R)‐3‐aminobutyrate from crotonic acid and ammonia. To obtain this mutant, a high‐throughput screening in combination with a focused permutational library was decisive for the success in this project. We achieved this by simultaneous randomisation of four residues within the substrate binding pocket and cluster screening in mixed population. Screening of 300 000 clones was necessary to find the BSASP‐C6 mutant which has β‐amino acid lyase activity. This exemplifies the need for efficient search and screening strategies in creating novel enzyme activities. The BSAPS‐C6 enzyme developed here surpasses the natural substrate functionality of aspartase and thus represents the proof‐of‐concept of application of this novel synthetic route to a broader set of β‐amino acids.
Dynamic Molecular Graphs: “Hopping” Structures
Authors: Cortés‐Guzmán Fernando , Rocha‐Rinza Tomas , Guevara‐Vela José Manuel , Cuevas Gabriel , Gómez Rosa María 
Published: April 2014

AbstractThis work aims to contribute to the discussion about the suitability of bond paths and bond‐critical points as indicators of chemical bonding defined within the theoretical framework of the quantum theory of atoms in molecules. For this purpose, we consider the temporal evolution of the molecular structure of [Fe{C(CH2)3}(CO)3] throughout Born–Oppenheimer molecular dynamics (BOMD), which illustrates the changing behaviour of the molecular graph (MG) of an electronic system. Several MGs with significant lifespans are observed across the BOMD simulations. The bond paths between the trimethylenemethane and the metallic core are uninterruptedly formed and broken. This situation is reminiscent of a “hopping” ligand over the iron atom. The molecular graph wherein the bonding between trimethylenemethane and the iron atom takes place only by means of the tertiary carbon atom has the longest lifespan of all the considered structures, which is consistent with the MG found by X‐ray diffraction experiments and quantum chemical calculations. In contrast, the η4complex predicted by molecular‐orbital theory has an extremely brief lifetime. The lifespan of different molecular structures is related to bond descriptors on the basis of the topology of the electron density such as the ellipticities at the FeCH2bond‐critical points and electron delocalisation indices. This work also proposes the concept of a dynamic molecular graph composed of the different structures found throughout the BOMD trajectories in analogy to a resonance hybrid of Lewis structures. It is our hope that the notion of dynamic molecular graphs will prove useful in the discussion of electronic systems, in particular for those in which analysis on the basis of static structures leads to controversial conclusions.
Photo‐ and Electrocatalytic H2 Production by New First‐Row Transition‐Metal Complexes Based on an Aminopyridine Pentadentate Ligand
Authors: Call Arnau , Codolà Zoel , Acuña‐Parés Ferran , Lloret‐Fillol Julio 
Published: April 2014

AbstractThe synthesis and characterisation of the pentadentate ligand 1,4‐di(picolyl)‐7‐(p‐toluenesulfonyl)‐1,4,7‐triazacyclononane (Py2Tstacn) and their metal complexes of general formula [M(CF3SO3)(Py2Tstacn)][CF3SO3], (M=Fe (1Fe), Co (1Co) and Ni (1Ni)) are reported. Complex 1Co presents excellent H2 photoproduction catalytic activity when using [Ir(ppy)2(bpy)]PF6 (PSIr) as photosensitiser (PS) and Et3N as electron donor, but 1Ni and 1Fe result in a low activity and a complete lack of it, respectively. On the other hand, all three complexes have excellent electrocatalytic proton reduction activity in acetonitrile, when using trifluoroacetic acid (TFA) as a proton source with moderate overpotentials for 1Co (0.59 V vs. SCE) and 1Ni (0.56 V vs. SCE) and higher for 1Fe (0.87 V vs. SCE). Under conditions of CH3CN/H2O/Et3N (3:7:0.2), 1Co (5 μM), with PSIr (100 μM) and irradiating at 447 nm gives a turnover number (TON) of 690 (n/n) and initial turnover frequency (TOF) (TON×t−1) of 703 h−1 for H2 production. It should be noted that 1Co retains 25 % of the catalytic activity for photoproduction of H2 in the presence of O2. The inexistence of a lag time for H2 evolution and the absence of nanoparticles during the first 30 min of the reaction suggest that the main catalytic activity observed is derived from a molecular system. Kinetic studies show that the reaction is −0.7 order in catalyst, and time‐dependent diffraction light scattering (DLS) experiments indicate formation of metal aggregates and then nanoparticles, leading to catalyst deactivation. By a combination of experimental and computational studies we found that the lack of activity in photochemical water reduction by 1Fe can be attributed to the 1FeII/I redox couple, which is significantly lower than the PSIrIII/II, while for 1Ni the pKa value (−0.4) is too small in comparison with the pH (11.9) imposed by the use of Et3N as electron donor.
Sensing of Phosphates by Using Luminescent EuIII and TbIII Complexes: Application to the Microalgal Cell Chlorella vulgaris
Authors: Nadella Sandeep , Sahoo Jashobanta , Subramanian Palani S. , Sahu Abhishek , Mishra Sandhya , Albrecht Markus 
Published: April 2014

AbstractPhenanthroline‐based chiral ligands L1 and L2 as well as the corresponding EuIII and TbIII complexes were synthesized and characterized. The coordination compounds show red and green emission, which was explored for the sensing of a series of anions such as F−, Cl−, Br−, I−, NO3−, NO2−, HPO42−, HSO4−, CH3COO−, and HCO3−. Among the anions, HPO42− exhibited a strong response in the emission property of both europium(III) and terbium(III) complexes. The complexes showed interactions with the nucleoside phosphates adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP). Owing to this recognition, these complexes have been applied as staining agents in the microalgal cell Chlorella vulgaris. The stained microalgal cells were monitored through fluorescence microscopy and scanning electron microscopy. Initially, the complexes bind to the outer cell wall and then enter the cell wall through holes in which they probably bind to phospholipids. This leads to a quenching of the luminescence properties.
Nucleic Acid Based Logical Systems
Authors: Han Da , Kang Huaizhi , Zhang Tao , Wu Cuichen , Zhou Cuisong , You Mingxu , Chen Zhuo , Zhang Xiaobing , Tan Weihong 
Published: April 2014

AbstractResearchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well‐regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA‐based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.
Simultaneous Carbon Coating and Lithiation of Oxides by Contact Reaction
Authors: Wächter Florian , Krumeich Frank , Nesper Reinhard 
Published: April 2014

AbstractChemical lithiation and carbon coating of cathode materials can lead to strongly improved electrochemical properties, especially if the active materials have low electronic conductivity. This behavior is quite often the case for new high‐capacity materials. A novel synthesis method is presented in which the two processes are performed simultaneously by employing Li2C2 as both the carbon and the lithium source. In this contact reaction, the acetylide anion C22− is oxidized to carbon and deposited directly on the surface of the active material, while lithium is reductively inserted into the oxidant. Two different synthesis routes are demonstrated: a tribochemical approach at room temperature and heat treatments between 150 and 600 °C. The applicability of these new carbon‐coating methods are demonstrated on various crystalline and amorphous LixV2O5 phases. The composites obtained were characterized by powder X‐ray diffraction, transmission electron microscopy, and Raman spectroscopy. In addition, electrochemical data confirm the chemical lithiation and show that lithiated LixV2O5 with specific phases can be prepared selectively.
Mechanopolymerchemie
Authors: Schulz‐Senft Mathias , Lipfert Matthias , Staubitz Anne 
Published: April 2014

AbstractChemischen Reaktionen kann auf verschiedenen Wegen Energie zugeführt werden, doch mechanische Energie blieb bisher ein Randphänomen. Ein selektiver Bindungsbruch in kleinen Molekülen benötigt große mechanische Kräfte, die sich nicht einfach auf einzelne Bindungen übertragen lassen. Da mechanische Arbeit das Produkt aus Kraft und Weg ist, ergeben sich für kurze Wege (im Bereich von Bindungslängen) große Kräfte für eine Bindungsspaltung. Makromoleküle sind jedoch länger und durch den größeren Weg sind die benötigten Kräfte für eine Bindungsspaltung geringer. Es wurden Bindungsspaltungen, Cycloreversionen und Isomerisierungen unter Einfluss mechanischer Energie beobachtet. Weiterhin kann mechanische Energie auch andere Reaktionsmechanismen hervorrufen als thermische oder Photoenergie. Praktische Anwendungen in diesem jungen Forschungsfeld entstehen noch und reichen derzeit von besserem Verständnis der Polymerzersetzung durch mechanische Kräfte zur Entwicklung von Dehnungssensoren mit mechanochromen Polymeren.
Cardiac Transplantation in African Americans: A Single‐Center Experience
Authors: Suryanarayana Prakash Goutham , Copeland Hannah , Friedman Mark , Copeland Jack G. 
Published: April 2014

AbstractBackgroundIn view of limited data on the subject of graft and patient survival differences between African American (AA) and non‐AA heart transplant recipients, we reviewed our experience.HypothesisThere is a higher mortality among AA recipients compared with non‐AA recipients after cardiac transplantation.MethodsThe study included all AA patients who have received a heart transplant in our center since 1983. Stepwise Cox regression was used for covariates affecting the survival. The χ2 test was employed to identify the effects of a mechanical assist device and pretransplant creatinine (Cr) on the outcomes in AA and non‐AA patients. Kaplan‐Meier curves were used to examine survival.ResultsThe average survival among AA recipients was 5.4 years, compared with 12 years for the non‐AA recipients, with 1‐, 5‐, and 10‐year survival rates of 80%, 55%, and 25%, respectively. This was found to be statistically inferior to the survival probabilities of 92%, 78%, and 58% for the non‐AA group (P < 0.005). Based on stepwise Cox regression, the variables such as ethnicity (P < 0.05), pretransplant Cr (P < 0.05), presence of a mechanical assist device (P < 0.005), and United Network for Organ Sharing (UNOS) status at transplant (P < 0.05) independently predicted the outcomes. Kaplan‐Meier analysis of pretransplant Cr level and survival showed that the AA group did significantly worse for all Cr classes.ConclusionsThere is a statistically significant difference in outcomes between AA and non‐AA patients after cardiac transplantation. African American patients have decreased survival over a period of time. Pretransplant Cr, ethnicity, presence of a mechanical assist device, and UNOS status at transplantation are independent predictors of outcomes.
Discovery, Synthesis and Characterization of a Highly Muscarinic Acetylcholine Receptor (mAChR)‐Selective M5‐Orthosteric Antagonist, VU0488130 (ML381): A Novel Molecular Probe
Authors: Gentry Patrick R. , Kokubo Masaya , Bridges Thomas M. , Cho Hyekyung P. , Smith Emery , Chase Peter , Hodder Peter S. , Utley Thomas J. , Rajapakse Anuruddha , Byers Frank , Niswender Colleen M. , Morrison Ryan D. , Daniels J. Scott , Wood Michael R. , Conn P. Jeffrey , Lindsley Craig W. 
Published: April 2014

AbstractOf the five G‐protein‐coupled muscarinic acetylcholine receptors (mAChRs; M1–M5), M5 is the least explored and understood due to a lack of mAChR subtype‐selective ligands. We recently performed a high‐throughput functional screen and identified a number of weak antagonist hits that are selective for the M5 receptor. Here, we report an iterative parallel synthesis and detailed molecular pharmacologic profiling effort that led to the discovery of the first highly selective, central nervous system (CNS)‐penetrant M5‐orthosteric antagonist, with sub‐micromolar potency (hM5 IC50=450 nM, hM5 Ki=340 nM, M1–M4 IC50 >30 μM), enantiospecific inhibition, and an acceptable drug metabolism and pharmacokinetics (DMPK) profile for in vitro and electrophysiology studies. This compound will be a powerful tool and molecular probe for the further investigation into the role of M5 in addiction and other diseases.