bluuebunny/crossref_metadata_2025 huggingface dataset:
Eine einzigartige Fassade aus Glasfaserbeton
Authors: Feirabend Steffen , Emami Amin , Riedel Erwin
Published: March 2014

Mit Glasfaserbeton lassen sich einzigartige Fassaden realisieren. Das Broad Museum im Herzen von Downtown Los Angeles ist hierfür ein Beispiel. Es wurde von den Architekten Diller Scofidio + Renfro entworfen. Das dreistöckige Kunstmuseum wird von einer Fassade aus mehr als 2 450 Glasfaserbetonelementen umhüllt. Die Elemente bestehen aus Glasfaserbetonschalen, die über einen Stahlrahmen mit dem Primärtragwerk verbunden sind. Mithilfe von 3D‐Software werden die organisch geformten Elemente konstruiert und bemessen. Für deren Herstellung im Spritzverfahren sind mehrere hundert individuell CNC‐gefräste Schalungen notwendig. Es existieren sowohl geschlossene als auch offene Glasfaserelemente. Hinter dieser Hülle aus Glasfaserbeton ist eine weitere Glasfassade mit bis zu 7,6 m hohen Glasscheiben. Durch die Öffnungen in den Glasfaserbetonelementen wird das indirekte Sonnenlicht in das Gebäude geleitet.

Die Bemessung und Detailausbildung der beiden sehr komplexen Gebäudehüllen berücksichtigt die hohen Anforderungen möglicher seismischer Belastungen in Los Angeles.

Das Gebäude befindet sich derzeit im Bau und wird mit seiner einzigartigen Architektur sicherlich ein neues Wahrzeichen der Stadt werden.

A unique building envelope with GFRC

GFRC allows to create unique building envelopes like for the Broad project. ‘The Broad’ is an art museum in the heart of downtown Los Angeles designed by the famous architects Diller Scofidio + Renfro. The three story high building is enclosed with a veil out of more than 2 450 GFRC (glass fiber reinforced concrete) elements. There are hundreds of individual types of GFRC elements designed and analyzed with the 3D‐software. Each type requires a separate formwork for its unique shaping and individual steel subframe for fixation to the primary structure.

The unique organic formed GFRC elements have funnel openings allowing the indirect sunlight to shine through so that the required artificial lightning could be reduced within the building. Behind the openings there is a second envelope of glass. This second envelope consists out of two side supported glass units with up to 7.6 m span. Due to the seismic requirements special precautions have been carried out in the design of this sophisticated GFRC and glass envelope. The unique building will be a new landmark in the City of Los Angeles when opened to the public.
Ductal‐Fassade Louis Vuitton in Aventura/Florida
Authors: Laufs Wilfried , Desarzens Patrick
Published: March 2014

Die Design‐Zielsetzung von besonderer, großflächiger Identität des Modehauses Louis Vuitton führte zu einer neuartigen Fassadenlösung, welche aus hochfestem Ductal‐LaFarge‐Beton (UHPC = ultra‐high performing concrete) offen vergossene Gussplattenlemente verwendet, die als rain‐screen over‐clad der bereits vorhandenen Gebäudehülle eine völlig neue Erscheinungsform geben. Mittels feinjustierbarer Unterkonstruktion für Hinterschnittanker und einer vorangegangenen Laser‐3D‐Vermessung und der Modellierung der einzelnen Fassadenschichten in Solidworks Software konnte eine praktisch fugenfreie flächige Oberfläche erzielt werden, die optisch auf den blumenartigen LV Mode‐Emblem‐Kreisen beruht und das Gebäude vollständig neu einhüllt. Der folgende Artikel beschreibt die Vorgehensweise zur Planung dieser zweiten Haut aus Sicht des Ingenieurs und Fassadenplaners, welche auch auf der Basis hoher Orkan‐Windlasten bemessen ist und das noch nicht genormte Ductal‐Material mittels Kleinteilversuchen und FEM‐Berechnungen rechnerisch nachweist.

Ductal Façade Louis Vuitton in Aventura/Florida – currently largest molded Ductal UHPC building envelope in the US

The design objective to create a unique, large surface identity for fashion company Louis Vuitton lead to an innovative façade solution which uses high‐strength Ductal LaFarge concrete (UHPC = ultra‐ high performing concrete) as open‐molded panel elements in a rain‐screen over‐clad application, which give the existing façade an entirely new appearance. Designing a finely adjustable sub‐structure for under‐cut anchors following 3D laser scans on site combined with Solidworks Software modeling of all envelope layers, a practically joint‐free façade surface was created, which is based on the flower‐like Louis Vuitton emblem circles wrapping the existing building in a completely new fashion. The following article describes the planning procedure for this second skin from a structural and façade engineering perspective, which is also designed based on high hurricane wind cladding loading and small‐scale 1:1 anchor testing data in combination with finite element modeling for the not‐yet fully standardized Ductal material.
Fassaden mit komplexer Geometrie – am Beispiel des Enzo Ferrari Museums in Modena
Authors: Blandini Lucio , Schmidt Timo , Winterstetter Thomas , Sobek Werner
Published: March 2014

Gebäude mit einer komplexen Fassadengeometrie bieten einen hohen Wiedererkennungswert und werden deshalb immer stärker nachgefragt. Unterstützt wird diese Entwicklung durch die raschen Fortschritte im Bereich der Planung und Fertigung von komplexen Geometrien. Am Beispiel des Enzo Ferrari Museums werden die Planungsprozesse und die technischen Lösungen erläutert, die die Realisierung einer solch komplexen Fassade auf höchstem gestalterischem und technischem Niveau ermöglicht haben. Die Fassade besteht zum einen aus einer geschwungenen transparenten Glaskonstruktion, die den Blick zum Geburtshaus von Enzo Ferrari lenkt; zum anderen besteht sie aus einem doppelt gekrümmten fugenlosen Aluminiumdach, das in Formensprache und Materialität an die Karosserie eines Sportwagens erinnert.

Geometrically complex façades – The Enzo Ferrari Museum in Modena as a case study

Geometrically complex buildings have a strong iconic character and are therefore highly demanded by clients all over the world. This trend is also supported by the constant progress in the design and production of such façades. The article highlights different approaches towards the materialization of complex architectural surfaces and looks in more detail at the Enzo Ferrari Museum as an excellent case study. This highly expressive façade is composed of a curved glass envelope facing Enzo Ferrari's birth house as well as of a free‐form yellow aluminum roof, thus recalling materials and formal elements that are typical of sports car design.
Modell zur rechnerischen Abschätzung des Korrosionswiderstands von Beton
Authors: Scheydt Jennifer C. , Müller Harald S.
Published: March 2014

Ausgehend von einem Forschungsprojekt zur Dauerhaftigkeit von ultrahochfestem Beton wurde ein deterministisches Modell zur Abschätzung des Korrosionswiderstands von Beton gegenüber chemischem Angriff hergeleitet. Der Korrosionswiderstand ist abhängig vom ebenfalls abgeleiteten Gefügewiderstand, der den Widerstand des nicht korrodierten, ungerissenen Betons gegenüber dem Eindringen flüssiger oder gasförmiger Medien beschreibt. Das Modell basiert auf physikalischen Zusammenhängen und zeichnet sich durch eine vergleichsweise einfache Handhabung und eine hohe Praxistauglichkeit aus. Es dient dazu, dem Anwender die Auswahl eines für den Einsatz in korrosiver Umgebung geeigneten Betons zu erleichtern. In erster Näherung ist die Modellprognose auch dann möglich, wenn nur wenige Angaben zum Beton vorliegen (Zusammensetzung und Druckfestigkeit des Betons, chemische Zusammensetzung des Bindemittels). Nachfolgend wird das Modell zur Prognose des Korrosionswiderstands vorgestellt und seine Handhabung erläutert.

Prediction of concrete resistance against corrosive attack

Within a research project on the durability of ultra high performance concrete, a model to predict the corrosion resistance of concrete against chemical attack was derived. The corrosion resistance depends on the structural resistance of the intact concrete against the ingress of liquid or gaseous media. The prediction model is based on physical properties and is characterised by an easy handling and a high suitability for the practical use. It is a helpful tool to find the concrete with the maximum resistance against an aggressive environment. Approximately, a prediction of the corrosion resistance is also possible if there is little information such as the composure or the compressive strength of the concrete and the chemical composure of the binder. In the following, the prediction model is introduced and its application is demonstrated.
Entwicklungsprinzipien und technische Grenzen der Herstellung zementarmer Betone
Authors: Haist Michael , Moffatt Jack S. , Breiner Raphael , Müller Harald S.
Published: March 2014

Der vorliegende Beitrag erläutert die Prinzipien der Mischungsentwicklung zementarmer, besonders nachhaltiger Betone. Hierbei wird gezielt der Frage nachgegangen, wie weit der Zementgehalt von Beton reduziert werden kann, ohne dabei zentrale betontechnologische Kenngrößen wie die Verarbeitbarkeit oder die Betondruckfestigkeit negativ zu beeinflussen. Das Kernelement des hier vorgestellten Mischungsentwurfsalgorithmus bilden Methoden der Packungsdichteoptimierung, durch die der Wasseranspruch der Korngemische bestehend aus Zement, Gesteinsmehlen und Gesteinskörnung minimiert werden kann. Im vorliegenden Beitrag wir dabei ein kombinierter Ansatz, bestehend aus dem Kornverteilungsmodell von Funk und Dinger sowie des CIPM‐Modells von Fennis, vorgeschlagen. Die durchgeführten experimentellen Untersuchungen belegen, dass es damit gelingt, die Bindemittelintensität (d.h. den Zementbedarf zur Sicherstellung von 1 MPa an Druckfestigkeit in 1 m3 Beton) um einen Faktor von ca. 3 gegenüber Normalbeton zu reduzieren. Die Untersuchungsergebnisse zeigen darüber hinaus, dass die Verarbeitbarkeit der Betone in guter Näherung als Funktion des Quotienten aus der tatsächlichen Packungsdichte und der maximal möglichen Packungsdichte des Korngemisches vorhergesagt werden kann.

Development principles and technical boundaries of concrete production with low cement content

This paper explains the principles of proportioning ecologically sustainable, cement reduced concrete mixtures. It attempts to provide an answer to the question of how the cement content in concrete can be reduced without adversely affecting key characteristics, such as consistency and compressive strength. The central element of the proposed algorithm for mixture development consists of particle packing models, with which the water demand of the granular mixture of cement, stone dust and aggregate can be minimized. In this report a combined approach, consisting of the particle size distribution model of Funk and Dinger and the CIPM model of Fennis, is proposed. The experimental investigations carried out suggest that it is possible to reduce the binder intensity (the demand for binding material to produce 1 MPa of compressive strength in 1 m3 of concrete) of the concrete by a factor of ca. 3 as compared to normal concrete when following this approach. The experimental investigations also suggest that the workability of the mixtures can be estimated well by the quotient function between the actual particle packing density and a theoretical maximum particle packing density of the granular mixture.
Hotel Nagold – ein komplexes Stahlbetontragwerk in innerstädtischem Umfeld
Authors: Hinz Holger , Münich Christian
Published: March 2014

Der siebenstöckige Neubau eines Hotels in Nagold scheint auf den ersten Blick – zumindest aus statischer Sicht – nur durchschnittlich komplex. Wie so oft liegt die Tücke aber im Detail. Bei diesem Projekt stellte die extrem hohe Anzahl an Abfang‐ und Lastumleitungsmaßnahmen besondere Anforderungen an die Tragwerksplanung. Zu erwähnen sind hierbei insbesondere die Abfangung von aussteifenden Wänden mittels Hochhängungen sowie die Anordnung von wandartigen (Krag‐)Trägern. Diese angesichts der relativ geringen Größe des Gebäudes überraschende Komplexität ist nicht zuletzt auf die sehr späte Einbindung des Tragwerksplaners in den Planungsablauf zurückzuführen. Die Einbindung erfolgte erst nach Abschluss des Architekturwettbewerbs, der eine Vielzahl von unterschiedlichen Nutzungen auf den einzelnen Ebenen vorsah. Aufgrund der zu berücksichtigenden Erdbebenzone und der extrem unregelmäßigen Tragwerksgeometrie wurden Nachweise nach dem Antwortspektrenverfahren erforderlich.

Hotel Nagold – a complex reinforced concrete structure in inner‐city environment

At first sight, the newly built seven‐storey hotel in Nagold, Germany, appears to be of only average complexity – that is at least from a structural point of view. However, as is often the case, the devil is in the detail. The extremely high number of support and load transfer measures required for this project place stringent demands on the structural design. The provision of supports for the bracing walls by means of elevation and the arrangement of the deep (cantilevered) beams are particularly worthy of mention. In view of the relatively small size of the building, the surprising level of complexity can be traced back to the fact that the structural design engineers were brought in at a very late stage of the planning process. The structural design engineers were not brought in until after the architectural competition, which envisaged a wide variety of different uses on the individual storeys, had been decided. The location in an earthquake zone and the extremely irregular geometry of the structure meant it was necessary to verify its structural safety utilizing the response spectrum method.
Ein Nachweiskonzept für die Querkrafttragfähigkeit verstärkter Stahlbetongurte von Verbundträgern im Bereich großer Stegöffnungen
Authors: Balzer Christian , Schnell Jürgen
Published: March 2014

Bei Stahlverbundträgern überträgt der Steg des Stahlträgers den größten Teil der Querkraft. Im Bereich von großen Stegöffnungen muss jedoch der Stahlbetongurt einen Großteil der Querkraftabtragung übernehmen. Die auf dem Stahlträgerflansch angeordneten Kopfbolzendübel dienen hier als Querkraftbewehrung. Durch den Einbau von zusätzlicher Querkraftbewehrung in Form von Dübelleisten im Betongurt seitlich neben dem Stahlträger kann die Traglast erheblich gesteigert werden.

Die Untersuchung des Querkrafttragverhaltens des Stahlbetongurts von Verbundträgern, die im Bereich von großen Stegöffnungen mit Dübelleisten verstärkt sind, sowie die Erstellung eines Nachweiskonzepts waren die Hauptthemen eines an der TU Kaiserslautern durchgeführten Forschungsprojekts. Im vorliegenden Beitrag wird dieses Nachweiskonzept vorgestellt, welches es ermöglicht, bei der Bemessung von Verbundträgern, die durch Stegöffnungen geschwächt sind, durch einen geringen Mehreinsatz von Bewehrung in Form von Dübelleisten eine deutliche Traglaststeigerung zu erreichen.

A design model to determine the shear load capacity of reinforced concrete chords of composite girders in the area of large web openings

The web of the steel girder carries the most of the shear force of composite beams. If the web is weakened by a large opening the concrete chord has to transfer the shear force nearly completely. The headed studs on top of the steel girder serve as shear reinforcement. In several experiments the shear load capacity can be improved significantly by the arrangement of shear rails as further reinforcement in the concrete chord alongside large web openings.

As part of a research project at the Kaiserslautern University of Technology, the influence of shear rails on the load bearing behavior of the concrete chord of composite beams with large web openings was investigated. In order to determine the shear load capacity of a concrete chord reinforced with shear rails, a design model was set up. This paper describes the design model that allows the structural design of composite girders in the area of web openings.
The effects of charge compensation on photoluminescence properties of a new green‐emitting ZnB2O4:Tb3+ phosphor
Authors: Liu Jie , Wu Zhan‐Chao , Wang Ping , Mei Yong‐Mei , Jiang Man , Kuang Shao‐Ping
Published: March 2014

Charge compensation is an effective way to eliminate charge defects and improve the luminescent intensity of phosphors. In this paper, a new green‐emitting phosphor ZnB2O4:Tb3+ was prepared by solid‐state reaction at 750°C. The effects of Tb3+ doping content and charge compensators (Li+, Na+ or K+) on photoluminescence properties of ZnB2O4:Tb3+ were investigated. X‐ray powder diffraction analysis confirms the sample has cubic structure of ZnB2O4. The excitation and emission spectra indicate that this phosphor can be excited by near ultraviolet light at 378 nm, and exhibits bright green emission with the highest peak at 544 nm corresponding to the 5D4→7F5 transition of Tb3+. The critical quenching concentration of Tb3+ in ZnB2O4 host is 8 mol%. The results of charge compensation show that the emission intensity can be improved by Na+ and K+. Specifically, K+ is the optimal one for ZnB2O4:Tb3+. Copyright © 2014 John Wiley & Sons, Ltd.
Changes in highly sensitive alpha‐fetoprotein for the prediction of the outcome in patients with hepatocellular carcinoma after hepatectomy
Authors: Toyoda Hidenori , Kumada Takashi , Tada Toshifumi , Ito Takanori , Maeda Atsuyuki , Kaneoka Yuji , Kagebayashi Chiaki , Satomura Shinji
Published: March 2014

We investigated changes in highly sensitive lens culinaris agglutinin A‐reactive fraction of alpha‐fetoprotein (hsAFP‐L3) measured using a novel method and its predictive ability for prognosis in patients with hepatocellular carcinoma (HCC) who underwent curative hepatectomy, comparing to other HCC tumor markers, that is, AFP, des‐gamma‐carboxy prothrombin (DCP), and AFP‐L3 measured with conventional method (cAFP‐L3). AFP, DCP, and AFP‐L3 including both cAFP‐L3 and hsAFP‐L3 were measured before and after curative hepatectomy in 187 patients. The percentage of patients with elevated tumor marker levels pre‐ and postoperatively was compared, and recurrence‐free and overall survival rates were analyzed based on changes in tumor markers. The percentages of patients with elevated AFP, DCP, and cAFP‐L3 decreased postoperatively. In contrast, the percentage of patients with elevated hsAFP‐L3 did not decrease postoperatively. Both recurrence‐free and overall survival rates were significantly lower in patients whose tumor marker levels remained elevated postoperatively than patients without tumor marker elevation postoperatively. Recurrence‐free and overall survival rates of patients in whom hsAFP‐L3 became elevated postoperatively despite normal preoperative hsAFP‐L3 levels were significantly lower than those of patients with normal hsAFP‐L3 postoperatively, and were similar to those of patients with persistent elevation. Preoperative elevations of AFP, DCP, and cAFP normalized in many patients postoperatively, but not for hsAFP‐L3. The elevation of hsAFP‐L3 identifies patients with poor prognosis despite the normalization of AFP and DCP.
Evolution of Iron(II)‐Finger Peptides by Using a Bipyridyl Amino Acid
Authors: Kang Mingchao , Light Kenneth , Ai Hui‐wang , Shen Weijun , Kim Chan Hyuk , Chen Peng R. , Lee Hyun Soo , Solomon Edward I. , Schultz Peter G.
Published: March 2014

We report the engineering of zinc‐finger‐like motifs containing the unnatural amino acid (2,2′‐bipyridin‐5‐yl)alanine (Bpy‐Ala). A phage‐display library was constructed in which five residues in the N‐terminal finger of zif268 were randomized to include both canonical amino acids and Bpy‐Ala. Panning of this library against a nine‐base‐pair DNA binding site identified several Bpy‐Ala‐containing functional Zif268 mutants. These mutants bind the Zif268 recognition site with affinities comparable to that of the wild‐type protein. Further characterization indicated that the mutant fingers bind low‐spin FeII rather than ZnII. This work demonstrates that an expanded genetic code can lead to new metal ion binding motifs that can serve as structural, catalytic, or regulatory elements in proteins.
Traumatic dissection of the internal carotid artery: simultaneous infarct of optic nerve and brain
Authors: Correa Edgar , Martinez Braulio
Published: March 2014

Key Clinical Message

Traumatic intracranial internal carotid artery dissection is a rare but significant cause of stroke in patients in their forties, leading to high morbidity and mortality. Simultaneous ischemic stroke and optic nerve infarction can occur. Clinical suspicion of dissection is determining in the acute management.
Active Site Plasticity of a Computationally Designed Retro‐Aldolase Enzyme
Authors: Obexer Richard , Studer Sabine , Giger Lars , Pinkas Daniel M. , Grütter Markus G. , Baker David , Hilvert Donald
Published: March 2014

RA110 is a computationally designed retro‐aldolase enzyme that utilizes amine catalysis to convert 4‐hydroxy‐4‐(6‐methoxy‐2‐naphthyl)‐2‐butanone to 6‐methoxy‐2‐naphthaldehyde and acetone. The original design accelerated substrate cleavage by a factor of 12 000 over background, and its activity was subsequently increased more than a thousand‐fold by directed evolution. The X‐ray structure of the evolved catalyst covalently modified with a 1,3‐diketone inhibitor deviates substantially from the design model, however, with the ligand adopting a completely different orientation than predicted. Moreover, significant activity was maintained even after relocation of the reactive lysine within the apolar binding pocket. These results suggest that the success of the original design is not ascribable to atomically accurate molecular recognition, but rather to successful placement of a reactive lysine adjacent to an apolar binding pocket. Nevertheless, the stabilizing interactions observed at the active site of the evolved variant suggest that improvements in the precision of design calculations will afford enzymes with higher catalytic activities.
Nanoporous Polymers: Bridging the Gap between Molecular and Solid Catalysts?
Authors: Rose Marcus
Published: March 2014

The combination of the advantageous properties of molecular and solid catalysts is considered the “Holy Grail” in catalysis research. Great potential is provided by nanoporous polymers. Chemically well‐defined moieties in combination with a high stability render these materials suitable as catalyst supports for liquid‐phase and even aqueous‐phase catalytic processes, especially regarding the transition from fossil resources to renewable resources. In this Minireview, recent developments are summarized, covering the three main approaches: solid metal‐free organocatalysts, immobilized molecular catalyst species, and supported metal nanoparticles and clusters. Their potential is evaluated and the question as to whether nanoporous polymers can bridge the gap between homogeneous and heterogeneous catalysis is critically discussed.
Single‐Particle Spectroscopy of Alcohol‐to‐Olefins over SAPO‐34 at Different Reaction Stages: Crystal Accessibility and Hydrocarbons Reactivity
Authors: Qian Qingyun , Ruiz‐Martínez Javier , Mokhtar Mohamed , Asiri Abdullah M. , Al‐Thabaiti Shaeel A. , Basahel Suliman N. , Weckhuysen Bert M.
Published: March 2014

The front cover artwork for Issue 3/2014 is provided by the Inorganic Chemistry and Catalysis group of Utrecht University. The image shows the concept of synchrotron‐based IR and UV/Vis microspectroscopy monitoring a catalytic reaction on a single SAPO‐34 crystal and the obtained spatially resolved information on the retained hydrocarbon species and crystal accessibility. See the Full Paper itself on http://dx.doi.org/10.1002/cctc.201300962.
Synthesis and Spin‐Trapping Properties of a Trifluoromethyl Analogue of DMPO: 5‐Methyl‐5‐trifluoromethyl‐1‐pyrroline N‐Oxide (5‐TFDMPO)
Authors: Karoui Hakim , Nsanzumuhire Céline , Le Moigne François , Hardy Micael , Siri Didier , Derat Etienne , Rockenbauer Antal , Ouari Olivier , Tordo Paul
Published: March 2014

The 5‐diethoxyphosphonyl‐5‐methyl‐1‐pyrroline N‐oxide superoxide spin adduct (DEPMPOOOH) is much more persistent (about 15 times) than the 5,5‐dimethyl‐1‐pyrroline N‐oxide superoxide spin adduct (DMPOOOH). The diethoxyphosphonyl group is bulkier than the methyl group and its electron‐withdrawing effect is much stronger. These two factors could play a role in explaining the different half‐lifetimes of DMPOOOH and DEPMPOOOH. The trifluoromethyl and the diethoxyphosphonyl groups show similar electron‐withdrawing effects but have different sizes. We have thus synthesized and studied 5‐methyl‐5‐trifluoromethyl‐1‐pyrroline N‐oxide (5‐TFDMPO), a new trifluoromethyl analogue of DMPO, to compare its spin‐trapping performance with those of DMPO and DEPMPO. 5‐TFDMPO was prepared in a five‐step sequence by means of the Zn/AcOH reductive cyclization of 5,5,5‐trifluoro‐4‐methyl‐4‐nitropentanal, and the geometry of the molecule was estimated by using DFT calculations. The spin‐trapping properties were investigated both in toluene and in aqueous buffer solutions for oxygen‐, sulfur‐, and carbon‐centered radicals. All the spin adducts exhibit slightly different fluorine hyperfine coupling constants, thereby suggesting a hindered rotation of the trifluoromethyl group, which was confirmed by variable‐temperature EPR studies and DFT calculations. In phosphate buffer at pH 7.4, the half‐life of 5‐TFDMPOOOH is about three times shorter than for DEPMPOOOH and five times longer than for DMPOOOH. Our results suggest that the stabilization of the superoxide adducts comes from a delicate balance between steric, electronic, and hydrogen‐bonding effects that involve the β group, the hydroperoxyl moiety, and the nitroxide.
Ytterbium(III) Porpholactones: β‐Lactonization of Porphyrin Ligands Enhances Sensitization Efficiency of Lanthanide Near‐Infrared Luminescence
Authors: Ke Xian‐Sheng , Yang Bo‐Yan , Cheng Xin , Chan Sharon Lai‐Fung , Zhang Jun‐Long
Published: March 2014

The near‐infrared (NIR) luminescence efficiency of lanthanide complexes is largely dependent on the electronic and photophysical properties of antenna ligands. Although porphyrin ligands are efficient sensitizers of lanthanide NIR luminescence, non‐pyrrolic porphyrin analogues, which have unusual symmetry and electronic states, have been much less studied. In this work, we used porpholactones, a class of β‐pyrrolic‐modified porphyrins, as ligands and investigated the photophysical properties of lanthanide porpholactones Yb‐1 a–5 a. Compared with Yb porphyrin complexes, the porpholactone complexes displayed remarkable enhancement of NIR emission (50–120 %). Estimating the triplet‐state levels of porphyrin and porpholactone in Gd complexes revealed that β‐lactonization of porphyrinic ligands lowers the ligand T1 state and results in a narrow energy gap between this state and the lowest excited state of Yb3+. Transient absorption spectra showed that YbIII porpholactone has a longer transient decay lifetime at the Soret band than the porphyrin analogue (30.8 versus 17.0 μs). Thus, the narrower energy gap and longer lifetime arising from β‐lactonization are assumed to enhance NIR emission of Yb porpholactones. To demonstrate the potential applications of Yb porpholactone, a water‐soluble Yb bioprobe was constructed by conjugating glucose to Yb‐1 a. Interestingly, the NIR emission of this Yb porpholactone could be specifically switched on in the presence of glucose oxidase and then switched off by addition of glucose. This is the first demonstration that non‐pyrrolic porphyrin ligands enhance the sensitization efficiency of lanthanide luminescence and also display switchable NIR emission in the region of biological analytes (800–1400 nm).
SnIV Porphyrin Scaffolds for Axially Bonded Multiporphyrin Arrays: Synthesis and Structure Elucidation by NMR Studies
Authors: Dvivedi Avanish , Pareek Yogita , Ravikanth Mangalampalli
Published: March 2014

A simple, one‐step, supramolecular strategy was adopted to synthesize SnIV‐porphyrin‐based axially bonded triads and higher oligomers by using meso‐pyridyl SnIV porphyrin, meso‐hydroxyphenyl‐21,23‐dithiaporphyrin, and RuII porphyrin as building blocks and employing complementary and non‐interfering SnIVO and RuII⋅⋅⋅N interactions. The multiporphyrin arrays are stable and robust and were purified by column chromatography. 1H, 1H–1H COSY and NOESY NMR spectroscopic studies were used to unequivocally deduce the molecular structures of SnIV‐porphyrin‐based triads and higher oligomers. Absorption and electrochemical studies indicated weak interaction among the different porphyrin units in triads and higher oligomers, in support of the supramolecular nature of the arrays. Steady‐state fluorescence studies on triads indicated the possibility of energy transfer in the singlet state from the basal SnIV porphyrin to the axial 21,23‐dithiaporphyrin. However, the higher oligomers were weakly fluorescent due to the presence of heavy RuII porphyrin unit(s), which quench the fluorescence of the SnIV porphyrin and 21,23‐dithiaporphyrin units.
Iron Dicarbonyl Complexes Featuring Bipyridine‐Based PNN Pincer Ligands with Short Interpyridine CC Bond Lengths: Innocent or Non‐Innocent Ligand?
Authors: Zell Thomas , Milko Petr , Fillman Kathlyn L. , Diskin‐Posner Yael , Bendikov Tatyana , Iron Mark A. , Leitus Gregory , Ben‐David Yehoshoa , Neidig Michael L. , Milstein David
Published: March 2014

A series of iron dicarbonyl complexes with bipyridine‐based PNN pincer ligands were synthesized and characterized by multinuclear NMR spectroscopy (1H, 13C, 15N, 31P), IR spectroscopy, cyclic voltammetry, 57Fe Mössbauer spectroscopy, XPS spectroscopy, and single‐crystal X‐ray diffraction. The complexes with the general formula [(R‐PNN)Fe(CO)2] (5: R‐PNN=tBu‐PNN=6‐[(di‐tert‐butylphosphino)methyl]‐2,2′‐bipyridine, 6: R‐PNN=iPr‐PNN=6‐[(diisopropylphosphino)methyl]‐2,2′‐bipyridine, and 7: R‐PNN=Ph‐PNN=6‐[(diphenylphosphino)methyl]‐2,2′‐bipyridine) feature differently P‐substituted PNN pincer ligands. Complexes 5 and 6 were obtained by reduction of the corresponding dihalide complexes [(R‐PNN)Fe(X)2] (1: R=tBu, X=Cl; 2: R=tBu, X=Br; 3: R=iPr, X=Cl; 4: R=iPr, X=Br) in the presence of CO. The analogous Ph‐substituted complex 7 was synthesized by a reaction of the free ligand with iron pentacarbonyl. The low‐spin complexes 5–7 (S=0) are diamagnetic and have distorted trigonal bipyramidal structures in solution, whereas in the solid state the geometries around the iron are best described as distorted square pyramidal. Compared to other structurally characterized complexes with these PNN ligands, shortened interpyridine CC bonds of about 1.43 Å were measured. A comparison with known examples, theoretically described as metal complexes bearing bipyridine π‐radical anions (bpy.−), suggests that the complexes can be described as FeI complexes with one electron antiferromagnetically coupled to the ligand‐based radical anions. However, computational studies, at the NEVPT2/CASSCF level of theory, reveal that the shortening of the CC bond is a result of extensive π‐backbonding of the iron center into the antibonding orbital of the bpy unit. Hence, the description of the complexes as Fe0 complexes with neutral bipyridine units is the favorable one.
Vortex‐Pattern Self‐Assembly in Mn‐Doped ZnSe Nanorods
Authors: Acharya Shinjita , Sarkar Suresh , Chakraborty Supriya , Pradhan Narayan
Published: March 2014

Spontaneous patterning of anisotropic nanostructures into ordered assemblies remains a challenging quest, which requires controlled innovative approaches. One way to achieve such ordering of 1D nanorods is by manipulating the varieties of interactions (attractive and repulsive forces) present in colloidal solutions of anisotropic nanocrystals. The other ingenuous pathway is solvent‐evaporation‐mediated self‐organization of the 1D nanorods. By following the second protocol, we have achieved exclusive pillar self‐assembled patterns of visible‐light‐emitting Mn‐doped ZnSe nanorods. The nanorods also exhibit intriguing vortex patterning observed by directional solvent evaporation from the nanorod solution. The effect of solvent evaporation to generate such unique morphologies on the TEM grid is discussed and the reported procedure to obtain the assembled patterns of visible‐light‐emitting, doped nanorods might be useful for future technological applications.
Silica Nanowire Arrays for Diffraction‐Based Bioaffinity Sensing
Authors: Loget Gabriel , Corn Robert M.
Published: March 2014

Arrays of electrodeposited silica nanowires (SiO2 NWs) have been fabricated over large areas (cm2) on fluoropolymer thin films attached to glass substrates by a combination of photolithography and electrochemically triggered sol–gel nanoscale deposition. Optical and scanning electron microscopy (SEM) measurements revealed that the SiO2 NW arrays had an average spacing of ten micrometers and an average width of 700 nm with a significant grain structure that was a result of the sol–gel deposition process. The optical diffraction properties at 633 nm of the SiO2 NW arrays were characterized when placed in contact with solutions by using a prism‐coupled total internal reflection geometry; quantification of changes in these diffraction properties was applied in various sensing applications. Bulk refractive index sensing by using the SiO2 NW grating was demonstrated with a sensitivity of 1.30×10−5 RIU. Toposelectively chemically modified SiO2 NW arrays were used for diffraction biosensing measurements of surface binding events, such as the electrostatic adsorption of gold nanoparticles and the bioaffinity adsorption of streptavidin onto a biotin monolayer. Finally, the application of the SiO2 NW arrays for practical medical‐diagnostic applications was demonstrated by monitoring the diffraction of SiO2 NW arrays functionalized with a single‐stranded (ss)DNA aptamer to detect human α‐thrombin from solutions at sub‐pathologic nanomolar concentrations.
Highly Diastereoselective and Regioselective Copper‐Catalyzed Nitrosoformate Dearomatization Reaction under Aerobic‐Oxidation Conditions
Authors: Yang Weibo , Huang Long , Yu Yang , Pflästerer Daniel , Rominger Frank , Hashmi A. Stephen K.
Published: March 2014

An unprecedented copper‐catalyzed acylnitroso dearomatization reaction, which expands the traditional acylnitroso ene reaction and acylnitroso Diels–Alder reaction to a new type of transformation, has been developed under aerobic oxidation. Intermolecular and intra‐/intermolecular reaction modes demonstrate an entirely different N‐ or O‐acylnitroso selectivity. Hence, we can utilize this reaction as a highly diastereoselective access to a series of new pyrroloindoline derivatives, which are important structural motifs for natural‐product synthesis.
Merging Gold and Organocatalysis: A Facile Asymmetric Synthesis of Annulated Pyrroles
Authors: Hack Daniel , Loh Charles C. J. , Hartmann Jan M. , Raabe Gerhard , Enders Dieter
Published: March 2014

The combination of cinchona‐alkaloid‐derived primary amine and AuI–phosphine catalysts allowed the selective CH functionalization of two adjacent carbon atoms of pyrroles under mild reaction conditions. This sequential dual activation provides seven‐membered‐ring‐annulated pyrrole derivatives in excellent yields and enantioselectivities.
Mitigation of Iron Toxicity and Iron, Zinc, and Manganese Nutrition of Wetland Rice Cultivars (Oryza sativa L.) Grown in Iron‐Toxic Soil
Authors: Shahid Mohammad , Nayak Amaresh Kumar , Shukla Arvind Kumar , Tripathi Rahul , Kumar Anjani , Raja Rajagounder , Panda Bipin Bihari , Meher Jitendriya , Bhattacharyya Pratap , Dash Debiprasad
Published: March 2014

Wetland rice in many humid tropical regions of Asia, Africa, and South America are affected by iron toxicity, which mainly occur due to increase in Fe(II) concentration in soil solution resulting from drop of redox potential arising from anaerobic situations in submerged rice fields. The high quantity of ferrous ions in the soil solution upsets the mineral element balance in rice plants and affects its growth. A field experiment was carried out in acidic laterite soil (pH 5.1) having 400 mg kg−1 diethylene triamine pentaacetic acid extractable Fe for developing strategies to combat Fe toxicity and to study Fe, Zn, and Mn nutrition in rice. The treatments included four cultivars and six soil management options. Soil pH increased upon submergence and stabilized at 6.2 in compost treated plots and 6.8 in lime treated plots after eight weeks of flooding. Application of lime resulted significantly higher yields in all the four cultivars over control. Among the cultivars lowest Fe concentration both in grain and straw was recorded in tolerant as compared to susceptible cultivars. The ratio of Fe/Mn in rice plants was highest under control and reduced with Fe toxicity management treatments. It was further observed that Fe/Mn ratio of tolerant cultivars was lower as compared to susceptible cultivars irrespective of amendments. Similar relations were also recorded for Fe/Zn ratio under different Fe toxicity management interventions. Thus, the application of lime and limiting plant nutrients, such as K, Mn, and Zn along with tolerant cultivars could be important components of Fe toxicity management in Fe toxic acid lateritic soils.
Clinical outcomes of carbon ion radiotherapy for locally advanced adenocarcinoma of the uterine cervix in phase 1/2 clinical trial (protocol 9704)
Authors: Wakatsuki Masaru , Kato Shingo , Ohno Tatsuya , Karasawa Kumiko , Kiyohara Hiroki , Tamaki Tomoaki , Ando Ken , Tsujii Hirohiko , Nakano Takashi , Kamada Tadashi , Shozu Makio ,   The Working Group of the Gynecological Tumor
Published: March 2014

BACKGROUND

This study sought to evaluate the toxicity and efficacy of carbon ion radiotherapy (C‐ion RT) for locally advanced adenocarcinoma of the uterine cervix in a phase 1/2 clinical trial.

METHODS

The treatment consisted of whole‐pelvic irradiation of 36.0 gray equivalents (GyE) in 12 fractions and local boost with dose escalation from 26.4 to 38.4 GyE in 8 fractions. The dose escalation was performed with careful observation of acute normal tissue responses. Total dose to the cervical tumor was 62.4 to 74.4 GyE in 20 fractions.

RESULTS

Between April 1998 and February 2010, 58 patients were treated with C‐ion RT in this clinical trial. The number of patients with stage IIB, IIIB, and IVA disease were 20, 35, and 3, respectively. Median tumor size was 5.5 cm (range, 3.0‐11.8 cm). Twenty‐seven patients had pelvic lymph node metastases. The median follow‐up period was 38 months. All patients completed the treatment schedule. Grade 2 or higher late toxicity was found in 8 patients: 5 with bladder and 2 with small intestine grade 2 toxicities, and 1 patient had grade 4 rectal complication, which was surgically salvaged. The 5‐year local control rate, local control rate including salvage surgery, and overall survival rate in all cases were 54.5%, 68.2%, and 38.1%, respectively.

CONCLUSIONS

Dose escalation of C‐ion RT for adenocarcinoma of the uterine cervix was accomplished without severe toxicities except in 1 case. Although the number of patients in this study was small, the results support continued investigation and analysis to confirm therapeutic efficacy. Cancer 2014;120:1663–1669. © 2014 American Cancer Society.
Functional Corannulene: Diverse Structures, Enhanced Charge Transport, and Tunable Optoelectronic Properties
Authors: Sanyal Somananda , Manna Arun K. , Pati Swapan K.
Published: March 2014

Chemical functionalization of various hydrocarbons, such as coronene, corannulene, and so forth, shows good promise in electronics applications because of their tunable optoelectronic properties. By using quantum chemical calculations, we have investigated the changes in the corannulene buckybowl structure, which greatly affect its electronic and optical properties when functionalized with different electron‐withdrawing imide groups. We find that the chemical nature and position of functional groups strongly regulate the stacking geometry, π‐stacking interactions, and electronic structure. Herein, a range of optoelectronic properties and structure–property relationships of various imide‐functionalized corannulenes are explored and rationalized in detail. In terms of carrier mobility, we find that the functionalization strongly affects the reorganization energy of corannulene, while the enhanced stacking improves hopping integrals, favoring the carrier mobility of crystals of pentafluorophenylcorannulene‐5‐monoimide. The study shows a host of emerging optoelectronic properties and enhancements in the charge‐transport characteristics of functionalized corannulene, which may find possible semiconductor and electronics applications.
Robust Nonsticky Superhydrophobicity by the Tapering of Aligned ZnO Nanorods
Authors: Tian Jian , Zhang Yaping , Zhu Jie , Yang Zhongzhen , Gao Xuefeng
Published: March 2014

The robust nonsticky superhydrophobicity of aligned nanoneedle films is reported. A facile, efficient, cheap, and available method based on the diffusion‐limited crystal growth principle is proposed for controlling the tapering of ZnO nanorods, the profiles of which can be tuned effectively by synergetic control over reaction time and temperature in an extremely strong alkaline reaction system. The synthesized nanoneedle, nanopencil, and nanorod arrays are chosen for studying the effects of nanoscale topography on anti‐droplet‐sticking ability. After silanization, all of them show excellent quasi‐static anti‐droplet‐stickiness, and water adhesion along the normal and lateral directions can be greatly reduced by the tapering of nanorods and eliminated by sharp nanoneedles. However, their antisticking stability is distinct under the droplet impact: the nanoneedle sample is still nonsticky but the nanorod sample loses its antisticking ability. Only ensuring the liquid/air interface is in the suspended nonwetting state is insufficient to obtain robust nonsticky surfaces, which also require extremely low solid–liquid van der Waals attraction.
History Effects in Lithium–Oxygen Batteries: How Initial Seeding Influences the Discharge Capacity
Authors: Rinaldi Ali , Wijaya Olivia , Hoster Harry E. , Yu Denis Y. W.
Published: March 2014

In laboratory experiments, Li–O2 systems show “sudden death” at capacities far below the theoretical value. Identifying how discharge products limit the total capacity is crucial in Li–O2 system. We investigated the effect of Li2O2 seed layer deposited on carbon cathode under potentiostatic conditions at increasing overpotentials to the subsequent slow discharge at galvanostatic condition. The discharge capacity attainable in the second step is found to vary by more than a factor of 3 depending on the history, i.e., the seed layer. These results provide evidence that the battery history is decisive for the total discharge capacities.
Small Molecular Donors for Organic Solar Cells Obtained by Simple and Clean Synthesis
Authors: Demeter Dora , Mohamed Salma , Diac Andreea , Grosu Ion , Roncali Jean
Published: March 2014

A small donor–acceptor molecule is synthesized in a two‐step procedure involving reaction of N,N‐diphenylhydrazine on 2,5‐diformylthiophene and Knoevenagel condensation. Results of UV/Vis absorption spectroscopy and cyclic voltammetry show that replacement of the phenyl ring bridge of a reference compound 2 by an azo group produces a slight red‐shift of λmax, an enhancement of the molecular absorption coefficient, and a decrease of the energy level of the frontier orbitals. A preliminary evaluation of the potentialities of compound 1 as donor material in a basic bilayer planar heterojunction cell of 28 mm2 active area using C60 as acceptor gave a short‐circuit current density of 6.32 mA cm−2 and a power conversion efficiency of 2.07 %.
Capacitance of p‐ and n‐Doped Graphenes is Dominated by Structural Defects Regardless of the Dopant Type
Authors: Ambrosi Adriano , Poh Hwee Ling , Wang Lu , Sofer Zdenek , Pumera Martin
Published: March 2014

Graphene materials possess attractive properties that can be used for the fabrication of supercapacitors with enhanced energy‐storage performance. It has been shown that both boron and nitrogen doping of graphene can improve the intrinsic capacitance of the material relative to the undoped precursor. We address the question of whether p‐doping (using boron as dopant) or n‐doping (using nitrogen as dopant) leads to increased capacitance relative to undoped graphene materials. Using thermal exfoliation we synthesized both boron‐ and nitrogen‐doped graphene materials and measured capacitance relative to the undoped material. After a full characterization by SEM analysis, X‐ray photoelectron spectroscopy, Raman spectroscopy, gamma‐ray activation analysis, Brunauer–Emmett–Teller analysis, and electrochemical techniques we demonstrate that the doping process does not lead to enhancement of capacitive behavior and that the main characteristic influencing capacitance is the presence of structural defects within the graphitic structure, independent of doping level.
Towards a Sustainable Manufacture of Hierarchical Zeolites
Authors: Verboekend Danny , Pérez‐Ramírez Javier
Published: March 2014

The front cover artwork is provided by Dr. Danny Verboekend and Prof. Javier Pérez‐Ramírez of ETH Zurich. The image metaphorically expresses how sustainability plays a key role in reducing the synthetic footprint of hierarchical zeolites (HZ). The Full Paper itself is available at 10.1002/cssc.201301313
Pbx1 activates Fgf10 in the mesenchyme of developing lungs
Authors: Li Wei , Lin Chieh‐Yu , Shang Ching , Han Pei , Xiong Yiqin , Lin Chien‐Jung , Yang Jing , Selleri Licia , Chang Ching‐Pin
Published: March 2014

Insufficiency of surfactants is a core factor in respiratory distress syndrome, which causes apnea and neonatal death, particularly in preterm infants. Surfactant proteins are secreted by alveolar type II cells in the lung epithelium, the differentiation of which is regulated by Fgf10 elaborated by the adjacent mesenchyme. However, the molecular regulation of mesenchymal Fgf10 during lung development has not been fully understood. Here, we show that Pbx1, a homeodomain transcription factor, is required in the lung mesenchyme for the expression of Fgf10. Mouse embryos lacking Pbx1 in the lung mesenchyme show compact terminal saccules and perinatal lethality with failure of postnatal alveolar expansion. Mutant embryos had severely reduced expression of Fgf10 and surfactant genes (Spa, Spb, Spc, and Spd) that are essential for alveolar expansion for gas exchange at birth. Molecularly, Pbx1 directly binds to the Fgf10 promoter and cooperates with Meis and Hox proteins to transcriptionally activate Fgf10. Our results thus show how Pbx1 controls Fgf10 in the developing lung. genesis 52:399–407, 2014. © 2014 Wiley Periodicals, Inc.