bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition‐Metal‐Free Intramolecular Carbene Aromatic Substitution/Büchner Reaction: Synthesis of Fluorenes and [6,5,7]Benzo‐fused Rings
Authors: Liu Zhenxing , Tan Haocheng , Wang Long , Fu Tianren , Xia Ying , Zhang Yan , Wang Jianbo
Published: January 2015

Intramolecular aromatic substitution and Büchner reaction have been established as powerful methods for the construction of polycyclic compounds. These reactions are traditionally catalyzed by RhII catalysts with α‐diazocarbonyl compounds as the substrates. Herein a transition‐metal‐free intramolecular aromatic substitution/Büchner reaction is presented. These reactions use readily available N‐tosylhydrazones as the diazo compound precursors and show wide substrate scope.
Feineinstellung der nucleophilen Reaktivität von Bor‐at‐Komplexen aus Aryl‐ und Heteroarylboronsäureestern
Authors: Berionni Guillaume , Leonov Artem I. , Mayer Peter , Ofial Armin R. , Mayr Herbert
Published: January 2015

Aus Thienyl‐ bzw. Furylboronsäureestern und Aryllithium‐Verbindungen hergestellte Bor‐at‐Komplexe wurden isoliert und durch Röntgenstrukturanalyse charakterisiert. Die Produkte und Mechanismen ihrer Reaktionen mit Carbenium‐ und Iminium‐Ionen wurden analysiert. Durch UV/Vis‐spektroskopische Verfolgung der Kinetik dieser Reaktionen wurde der Einfluss der Aryl‐Substituenten, der Diol‐Liganden (Pinakol, Ethylenglykol, Neopentylglykol, Brenzkatechin) und der Gegenionen auf die nucleophile Reaktivität der Bor‐at‐Komplexe untersucht. Eine Hammett‐Korrelation bestätigte die polare Natur ihrer Reaktionen mit Benzhydrylium‐Ionen, und die Korrelation lg k(20 °C)=sN(E+N) wurde verwendet, um die Nucleophilie der Bor‐at‐Komplexe zu bestimmen und mit der anderer Borate und Boronate zu vergleichen. Die Neopentylglykol‐ und Ethylenglykol‐Derivate sind 104‐mal reaktiver als die Pinakol‐ und Brenzkatechin‐Derivate.
A Complex Perovskite‐Type Oxynitride: The First Photocatalyst for Water Splitting Operable at up to 600 nm
Authors: Pan Chengsi , Takata Tsuyoshi , Nakabayashi Mamiko , Matsumoto Takao , Shibata Naoya , Ikuhara Yuichi , Domen Kazunari
Published: January 2015

One of the simplest methods for splitting water into H2 and O2 with solar energy entails the use of a particulate‐type semiconductor photocatalyst. To harness solar energy efficiently, a new water‐splitting photocatalyst that is active over a wider range of the visible spectrum has been developed. In particular, a complex perovskite‐type oxynitride, LaMgxTa1−xO1+3xN2−3x (x≥1/3), can be employed for overall water splitting at wavelengths of up to 600 nm. Two effective strategies for overall water splitting were developed. The first entails the compositional fine‐tuning of a photocatalyst to adjust the bandgap energy and position by forming a series of LaMgxTa1−xO1+3xN2−3x solid solutions. The second method is based on the surface coating of the photocatalyst with a layer of amorphous oxyhydroxide to control the surface redox reactions. By combining these two strategies, the degradation of the photocatalyst and the reverse reaction could be prevented, resulting in successful overall water splitting.
Oxide‐Supported IrNiOx Core–Shell Particles as Efficient, Cost‐Effective, and Stable Catalysts for Electrochemical Water Splitting
Authors: Nong Hong Nhan , Oh Hyung‐Suk , Reier Tobias , Willinger Elena , Willinger Marc‐Georg , Petkov Valeri , Teschner Detre , Strasser Peter
Published: January 2015

Active and highly stable oxide‐supported IrNiOx core–shell catalysts for electrochemical water splitting are presented. IrNix@IrOx nanoparticles supported on high‐surface‐area mesoporous antimony‐doped tin oxide (IrNiOx /Meso‐ATO) were synthesized from bimetallic IrNix precursor alloys (PA‐IrNix /Meso‐ATO) using electrochemical Ni leaching and concomitant Ir oxidation. Special emphasis was placed on Ni/NiO surface segregation under thermal treatment of the PA‐IrNix /Meso‐ATO as well as on the surface chemical state of the particle/oxide support interface. Combining a wide array of characterization methods, we uncovered the detrimental effect of segregated NiO phases on the water splitting activity of core–shell particles. The core–shell IrNiOx /Meso‐ATO catalyst displayed high water‐splitting activity and unprecedented stability in acidic electrolyte providing substantial progress in the development of PEM electrolyzer anode catalysts with drastically reduced Ir loading and significantly enhanced durability.
Pickering Interfacial Catalysis for Biphasic Systems: From Emulsion Design to Green Reactions
Authors: Pera‐Titus Marc , Leclercq Loïc , Clacens Jean‐Marc , De Campo Floryan , Nardello‐Rataj Véronique
Published: January 2015

Pickering emulsions are surfactant‐free dispersions of two immiscible fluids that are kinetically stabilized by colloidal particles. For ecological reasons, these systems have undergone a resurgence of interest to mitigate the use of synthetic surfactants and solvents. Moreover, the use of colloidal particles as stabilizers provides emulsions with original properties compared to surfactant‐stabilized emulsions, microemulsions, and micellar systems. Despite these specific advantages, the application of Pickering emulsions to catalysis has been rarely explored. This Minireview describes very recent examples of hybrid and composite amphiphilic materials for the design of interfacial catalysts in Pickering emulsions with special emphasis on their assets and challenges for industrially relevant biphasic reactions in fine chemistry, biofuel upgrading, and depollution.
Synthesis of Polycyclic Tertiary Carbinamines by Samarium Diiodide Mediated Cyclizations of Indolyl Sulfinyl Imines
Authors: Rao Chintada Nageswara , Lentz Dieter , Reissig Hans‐Ulrich
Published: January 2015

Samarium diiodide mediated cyclizations of N‐acylated indole derivatives bearing sulfinyl imine moieties afforded polycyclic tertiary carbinamines with moderate to excellent diastereoselectivities. Lithium bromide and water turned out to be the best additives to achieve these transformations in good yields. Using enantiopure sulfinyl imines the outcome strongly depends on the reactivity of the indole moiety. Whereas with unactivated indole derivatives desulfinylation and formation of racemic products was observed, indoles bearing electron‐withdrawing substituents at C‐3 afforded the polycyclic products with intact N‐sulfinyl groups and with excellent diastereoselectivity, finally allowing the preparation of enantiopure tertiary carbinamines. The mechanisms of these processes are discussed.
Heterogeneous Water Oxidation: Surface Activity versus Amorphization Activation in Cobalt Phosphate Catalysts
Authors: González‐Flores Diego , Sánchez Irene , Zaharieva Ivelina , Klingan Katharina , Heidkamp Jonathan , Chernev Petko , Menezes Prashanth W. , Driess Matthias , Dau Holger , Montero Mavis L.
Published: January 2015

Is water oxidation catalyzed at the surface or within the bulk volume of solid oxide materials? This question is addressed for cobalt phosphate catalysts deposited on inert electrodes, namely crystallites of pakhomovskyite (Co3(PO4)2⋅8 H2O, Pak) and phosphate‐containing Co oxide (CoCat). X‐ray spectroscopy reveals that oxidizing potentials transform the crystalline Pak slowly (5–8 h) but completely into the amorphous CoCat. Electrochemical analysis supports high‐TOF surface activity in Pak, whereas its amorphization results in dominating volume activity of the thereby formed CoCat material. In the directly electrodeposited CoCat, volume catalysis prevails, but not at very low levels of the amorphous material, implying high‐TOF catalysis at surface sites. A complete picture of heterogeneous water oxidation requires insight in catalysis at the electrolyte‐exposed “outer surface”, within a hydrated, amorphous volume phase, and modes and kinetics of restructuring upon operation.
Revealing the Preferred Interlayer Orientations and Stackings of Two‐Dimensional Bilayer Gallium Selenide Crystals
Authors: Li Xufan , Basile Leonardo , Yoon Mina , Ma Cheng , Puretzky Alexander A. , Lee Jaekwang , Idrobo Juan C. , Chi Miaofang , Rouleau Christopher M. , Geohegan David B. , Xiao Kai
Published: January 2015

Characterizing and controlling the interlayer orientations and stacking orders of two‐dimensional (2D) bilayer crystals and van der Waals (vdW) heterostructures is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) crystals that result from different layer stackings provide an ideal platform to study the stacking configurations in 2D bilayer crystals. Through a controllable vapor‐phase deposition method, bilayer GaSe crystals were selectively grown and their two preferred 0° or 60° interlayer rotations were investigated. The commensurate stacking configurations (AA′ and AB stacking) in as‐grown bilayer GaSe crystals are clearly observed at the atomic scale, and the Ga‐terminated edge structure was identified using scanning transmission electron microscopy. Theoretical analysis reveals that the energies of the interlayer coupling are responsible for the preferred orientations among the bilayer GaSe crystals.
Stable Heterocyclopentane‐1,3‐diyls
Authors: Hinz Alexander , Schulz Axel , Villinger Alexander
Published: January 2015

Diphosphadiazanediyl, [(μ‐NR)P]2 (R=Ter=2,6‐dimesitylphenyl), is known to readily activate small molecules with multiple bonds. CO is an especially intriguing species for activation, because either 1,1‐ or 1,2‐bridging mode would lead to a [1.1.1]bicycle or a carbene, respectively. The activation of CO with diphosphadiazanediyl already occurs at ambient temperatures (1 bar, 25 °C). However, CO is involved in an unprecedented ring expansion reaction under preservation of the biradical character, which leads to the formation of the first stable cyclopentane‐1,3‐diyl analogue displaying photochromic molecular switch characteristics.
Fine‐Tuning the Nucleophilic Reactivities of Boron Ate Complexes Derived from Aryl and Heteroaryl Boronic Esters
Authors: Berionni Guillaume , Leonov Artem I. , Mayer Peter , Ofial Armin R. , Mayr Herbert
Published: January 2015

Boron ate complexes derived from thienyl and furyl boronic esters and aryllithium compounds have been isolated and characterized by X‐ray crystallography. Products and mechanisms of their reactions with carbenium and iminium ions have been analyzed. Kinetics of these reactions were monitored by UV/Vis spectroscopy, and the influence of the aryl substituents, the diol ligands (pinacol, ethylene glycol, neopentyl glycol, catechol), and the counterions on the nucleophilic reactivity of the boron ate complexes were examined. A Hammett correlation confirmed the polar nature of their reactions with benzhydrylium ions, and the correlation lg k(20 °C)=sN(E+N) was employed to determine the nucleophilicities of the boron ate complexes and to compare them with those of other borates and boronates. The neopentyl and ethylene glycol derivatives were found to be 104 times more reactive than the pinacol and catechol derivatives.
Engineered L‐Serine Hydroxymethyltransferase from Streptococcus thermophilus for the Synthesis of α,α‐Dialkyl‐α‐Amino Acids
Authors: Hernandez Karel , Zelen Igor , Petrillo Giovanna , Usón Isabel , Wandtke Claudia M. , Bujons Jordi , Joglar Jesús , Parella Teodor , Clapés Pere
Published: January 2015

α,α‐Disubstituted α‐amino acids are central to biotechnological and biomedical chemical processes for their own sake and as substructures of biologically active molecules for diverse biomedical applications. Structurally, these compounds contain a quaternary stereocenter, which is particularly challenging for stereoselective synthesis. The pyridoxal‐5′‐phosphate (PLP)‐dependent L‐serine hydroxymethyltransferase from Streptococcus thermophilus (SHMTSth; EC 2.1.2.1) was engineered to achieve the stereoselective synthesis of a broad structural variety of α,α‐dialkyl‐α‐amino acids. This was accomplished by the formation of quaternary stereocenters through aldol addition of the amino acids D‐Ala and D‐Ser to a wide acceptor scope catalyzed by the minimalist SHMTSth Y55T variant overcoming the limitation of the native enzyme for Gly. The SHMTSth Y55T variant tolerates aromatic and aliphatic aldehydes as well as hydroxy‐ and nitrogen‐containing aldehydes as acceptors.
Investigation on jet stability, fiber diameter, and tensile properties of electrospun polyacrylonitrile nanofibrous yarns
Authors: Barua Bipul , Saha Mrinal C.
Published: January 2015

Electrospinning is a flexible and efficient method for producing nanofibers by using relatively dilute polymer solution. However, there are many parameters related to material and processing that influence the morphology and property of the nanofibers. This study investigates the influence of electric field and flow rate on diameter and tensile properties of nanofibers produced using polyacrylonitrile (PAN)‐dimethylformamide (DMF) solution. Stability of the spinning jet is investigated via fiber current measurement and an image system at different electric fields and solution flow rates. It is observed that a set of electric field and flow rate conditions favor producing thinnest, strongest, and toughest nanofibers during electrospinning process. Other conditions may lead to instability of the Taylor cone, discontinuous jet, larger diameter fiber, and lower mechanical properties. Finally, a simple dynamic whipping model is adopted to correlate the nanofiber diameter with volumetric charge density and is found to be excellent validating our experimental results. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41918.
Unexpected Metal‐Free Transformation of gem‐Dibromomethylenes to Ketones under Acetylation Conditions
Authors: Kimura Rino , Sawayama Yusuke , Nakazaki Atsuo , Miyamoto Kazunori , Uchiyama Masanobu , Nishikawa Toshio
Published: January 2015

Novel conditions for the transformation of gem‐dibromomethylenes to ketones are described. gem‐Dibromo compounds were treated with acetic anhydride and triethylamine in dichloromethane/water at room temperature under an air atmosphere to give the corresponding ketones in moderate yields. A radical mechanism is proposed based on experimental results.
Direct Oxidative Arylation of Aryl CH Bonds with Aryl Boronic Acids via Pd Catalysis Directed by the N,N‐Dimethylaminomethyl Group
Authors: Zhang Ji‐Cheng , Shi Jiang‐Ling , Wang Bi‐Qin , Hu Ping , Zhao Ke‐Qing , Shi Zhang‐Jie
Published: January 2015

Biaryl skeletons were directly constructed via palladium‐catalyzed ortho‐arylation of N,N‐dimethyl benzylamine with aryl boronic acids with high efficiency and high regioselectivity under open‐flask conditions. The N,N‐dimethylaminomethyl group was first applied as a directing group in such an oxidative coupling. Various substrates proved to be efficient coupling partners, furnishing the corresponding ortho‐monoarylated or ‐diarylated arenes in moderate to good yields under mild conditions.
Modification of Bafilomycin Structure to Efficiently Synthesize Solid‐State NMR Probes that Selectively Bind to Vacuolar‐Type ATPase
Authors: Shibata Hajime , Tsuchikawa Hiroshi , Hayashi Tatsuru , Matsumori Nobuaki , Murata Michio , Usui Takeo
Published: January 2015

Bafilomycin (Baf) is one of the most potent inhibitors of vacuolar‐type ATPase, which is strongly implicated in age‐related diseases. However, the binding site of the antibiotic on the protein remains unclear because of the complexity of the structure of Baf bound to the target subunit in the transmembrane region. For conducting structural studies by applying solid‐state NMR, which is one of the most promising methodologies available for structural analysis in membrane system, preparing bioactive fluorinated Baf analogues is essential. In this study two Baf analogues were carefully designed and efficiently synthesized through the convergent coupling of three segments. Biological evaluation revealed that the activity of 24‐F‐Baf was comparable to that of Baf, indicating its utility as a potential probe for solid‐state NMR analysis. By contrast, desmethylated 24‐F‐Baf exhibited markedly diminished activity. The absence of two methyl groups caused a critical conformational change in the macrocyclic core structure necessary for binding to the target protein.
Feinbetonmatrix für Textilbeton
Authors: Lieboldt Matthias
Published: January 2015

Zur Herstellung von dünnen, leistungsfähigen Verstärkungsschichten mit feinmaschigen Bewehrungsstrukturen, wie beispielsweise Carbongelege, können nur spezielle Feinbetonmatrices verwendet werden, welche sich deutlich von konventionellen Betonen unterscheiden. Die granulometrische und mineralogische Zusammensetzung des Feinbetons muss sowohl auf die Eigenschaften der aus feinen Multifilamentgarnen bestehenden textilen Gelege als auch auf die Verarbeitungsprozesse abgestimmt sein. Im Rahmen der Grundlagenforschung wurden geeignete Rezepturen entwickelt und hinsichtlich des Verbundverhaltens mit der Bewehrung und der Dauerhaftigkeit eingehend untersucht. Jedoch sind diese Rezepturen wegen der zahlreichen trockenen und flüssigen Komponenten für eine baustellengerechte Anwendung ungeeignet. Es musste eine Trockenmischung entwickelt werden, die adäquate Eigenschaften aufweist. Im Folgenden werden die Anforderungen an den Feinbeton und die Umsetzung in einer praxistauglichen Werktrockenmischung erläutert. Im Besonderen wird auf die in der systemisch zugehörigen allgemeinen bauaufsichtlichen Zulassung geforderten Eigenschaften sowie die Qualitätssicherung und Verarbeitungsprozesse des Feinbetons eingegangen.

Fine‐grained concrete matrix for TRC – requirements, adaption to construction site operation, properties

For the preparation of thin, capable reinforcement layers with finely woven reinforcement structures, such as carbon fabrics, only special matrices of fine concrete can be used, which significantly differ from conventional concretes mixtures. The granulometric and mineralogical composition of the fine concrete shall be adjusted to both, the properties of the textile fabrics consisting of fine multifilament yarn, as well as to the processing processes. In the context of fundamental research suitable formulations have been developed and investigated concerning the bond behavior of the reinforcement and the durability. However, these formulations are inappropriate regarding the numerous dry and liquid components of a construction site application. A dry mixture had to be developed which has adequate properties. Hereinafter the requirements of the fine concrete and the implementation of a practical factory dry mixture are explained. Specifically, the characteristics that are required by the general technical approval, just as the quality management and processing processes of the fine concrete will be explained.
Nutzung der abZ “Verfahren zur Verstärkung von Stahlbeton mit TUDALIT® (Textilbewehrter Beton)”
Authors: Assmann Ulrich , Offermann Peter
Published: January 2015

Mit der Marke TUDALIT® sind höchste Ansprüche an die Leis‐tungsfähigkeit der Materialien und an die Qualität der Ausführung verbunden. Auf diese hohen Qualitätsstandards hat sich der Verband TUDALIT e.V., dem Forscher, Hersteller, Planer und Anwender angehören, verständigt. Die TUDAG ist Inhaber der allgemeinen bauaufsichtlichen Zulassung und eröffnet allen interessierten Bauschaffenden die Lizenznahme unter der Voraussetzung, dass die hohen Standards der Marke TUDALIT® zwingend eingehalten werden.

Use of the general technical approval “method of strengthening of steel reinforced concrete with TUDALIT® (textile reinforced concrete)”.

With the brand TUDALIT®, high demands on the performance of the materials and the quality of construction work are connected. The members of the Association TUDALIT e. V. – these are researchers, manufacturers, designers and users – have made an agreement about these high quality standards. The TUDAG is the owner of general technical approval and opens up license acquisition to all interested builders on condition that the high standards of the brand TUDALIT® are complied.
Textilbeton – Eigenschaften des Verbundwerkstoffs
Authors: Lorenz Enrico , Schütze Elisabeth , Weiland Silvio
Published: January 2015

Werden textile Bewehrungsgelege in Feinbeton eingebettet, entsteht der Verbundwerkstoff textilbewehrter Beton oder kurz Textilbeton. Wie bei jedem Verbundwerkstoff ist es in der Regel nicht möglich, aus den Eigenschaften der Ausgangsstoffe direkt auf das Verbundtragverhalten zu schließen. Dafür sind Kenntnisse über die Verbundeigenschaften zwischen Filamenten, Garn bzw. Textil und Matrix entscheidend. Neben der Charakterisierung und Identifikation der einzelnen Systemkomponenten sind zur allgemeinen Beschreibung des Tragverhaltens auch experimentelle Untersuchungen am Verbundwerkstoff erforderlich, die als Basis für Materialoptimierung, Identifikation von Tragmechanismen sowie Anwendung von Berechnungsmodellen dienen. Im Beitrag werden die grundlegenden Zulassungsversuche zur Ermittlung und Überprüfung der Material‐ und Bemessungskennwerte von Textilbeton zur Bauwerksverstärkung vorgestellt.

Textile Reinforced Concrete – properties of the composite material

By embedding a textile reinforcement into a fine‐grained concrete the composite material textile reinforced concrete is created. As with any composite material, it is not generally possible to deduce the structural behavior of the composite from the properties of the raw materials. This is why a profound knowledge of the bond behavior between filaments, rovings or textile and the concrete matrix is essential. In addition to the characterization and identification of the individual system components, experimental investigations on the composite material are necessary to describe the material behavior. These form the basis for material optimization, the identification of bearing mechanisms and the application of analytical models. This publication presents the fundamental approval tests that were conducted to determine and verify the material and characteristic values of textile reinforced concrete for the strengthening of bending‐stressed steel reinforced concrete members.
Bemessung texilbetonverstärkter Stahlbetonbauteile unter Biegebeanspruchung
Authors: Frenzel Michael
Published: January 2015

In diesem Beitrag werden auf der herkömmlichen Stahlbetonbemessung basierende Berechnungs‐ und Bemessungsmodelle zur Bestimmung der Tragfähigkeit biegebeanspruchter, textilbetonverstärkter Stahlbetonbauteile vorgestellt. Mit dem aufgeführten Berechnungsansatz können sowohl die verschiedenen Versagensarten Textilzug‐, Stahlzug‐ und Betondruckversagen als auch eingebrachte Spannungszustände vor der Verstärkungsmaßnahme berücksichtigt werden. Neben einem iterativen Berechnungsablauf werden zwei vereinfachte Formelapparate zur überschläglichen Dimensionierung der für die Verstärkung erforderlichen Textilbetonschicht vorgestellt. Der Artikel stellt des Weiteren Tabellen und Diagramme für eine einfache und praxisgerechte Bemessung bereit. Die Anwendung der Berechnungs‐ und Bemessungsverfahren wird abschließend anhand von Beispielrechnungen demonstriert.

Design of RC members strengthened with textile reinforced concrete under flexural bending

This paper presents analysis methods and design models based on the conventional reinforced concrete design procedure, that are used to determine the nominal capacity of flexural bending of steel reinforced concrete members strengthened with textile reinforcement. The shown computational algorithm allows considering different failure modes such as textile and steel tensile failure, concrete compressive collapse and introduced stress states, which act before the strengthening measure. In addition to an iterative calculation process, two simplified formulas are given to easily calculate the necessary area of reinforcement of strengthened elements under bending. Furthermore, the article provides tables and charts for a simple and practical design calculation. The application of analysis and design methods is demonstrated conclusively on the basis of example calculations.
Anwendungsbeispiele für Textilbetonverstärkung
Authors: Erhard Erich , Weiland Silvio , Lorenz Enrico , Schladitz Frank , Beckmann Birgit , Curbach Manfred
Published: January 2015

In diesem Beitrag werden am Beispiel bereits durchgeführter Verstärkungsbaumaßnahmen praktische Anwendungen für Textilbetonverstärkungen vorgestellt. Textilbetonverstärkungen zeichnen sich durch eine hohe Tragfähigkeit bei geringen Verstärkungsschichtdicken und geringem zusätzlichen Eigengewicht aus. Außerdem ermöglichen sie die Herstellung hochwertiger Betonoberflächen. Aus diesen Gründen ist Textilbeton für verschiedene Sanierungsmaßnahmen geeignet. Neben der Steigerung der Tragfähigkeit bestehender Bausubstanz kann Textilbeton beim Erhalt und der Ertüchtigung historisch wertvoller Bauwerke oder auch bei Bauwerken mit besonderen Anforderungen an die Oberflächenbeschaffenheit eingesetzt werden.

Applications of textile reinforced concrete strengthening – restoration and strengthening of built constructions with textile reinforced strengthening

Example applications and realised building projects with textile reinforced concrete (TRC) strengthening are presented in this work. TRC strengthening stands out due to high load carrying capacity including minor thickness of the strengthening layer and minor additional dead load. Furthermore, TRC enables the manufacturing of surfaces of high quality. For this reasons, TRC is feasible for different restoration and renovation applications. Beside the increase of the load carrying capacity of existing buildings, TRC can be used for the preservation and rehabilitation of historically precious buildings or for buildings with special requirements with regard to the concrete surface quality.
Focus on cultivating relationships leads to campus safety improvements
Authors: Gomez Cynthia
Published: January 2015

After serving as an officer in the Columbus Police Department for 29 years, Craig A. Stone was ready for something different. Having worked with The Ohio State University's campus safety team during football games, he was drawn to campus law enforcement.
Be ready to deal with disruptions that impact your career
Authors: Hope Joan
Published: January 2015

When you're an administrator, unexpected transitions could derail your agenda or disrupt your career. For instance, your department could face reorganization, an expected promotion may be given to someone else, or a new leader may have a different vision for your unit or your position than you do.
Essential Roles of Proton Transfer in Photocatalytic Redox Reactions
Authors: Chen Chuncheng , Shi Tao , Chang Wei , Zhao Jincai
Published: January 2015

Nowadays, semiconductor‐based heterogeneous photocatalysis is receiving much more attention than ever before owing to the increasing challenge of environmental pollution and worldwide demand for clean energy. The stoichiometry of the photocatalytic reactions usually includes the simultaneous gain or loss of electrons and protons. However, not enough emphasis has been placed on the effect of proton transfer on the photocatalytic reactions, particularly on the kinetics of interfacial redox steps. In this article, we highlight the effects of proton on the interfacial electron transfer during the photocatalytic redox reactions. We try to emphasize that the proton transfer can largely determine the energetic profile and reaction pathway by participating in the interfacial redox reactions. Better understanding on the roles and the detailed mechanisms of proton transfer in the photocatalytic surface reactions is required for the further improvement of photocatalytic efficiency.
Reactivation and Reuse of Platinum‐Based Spent Catalysts for Combustion of Exhaust Organic Gases
Authors: Rui Zebao , Wu Shangren , Ji Hongbing , Liu Zili
Published: January 2015

The optimum pretreatment method for a Pt‐based spent catalyst for the removal of exhaust organic gases was examined. Two different pretreatment procedures with gas and aqueous solution were evaluated. Results obtained from the catalytic combustion of trace CH4 demonstrate that air pretreatment has a slightly positive effect. NaBH4 solution treatment leads to the highest initial activity. No pulverization of the granule size and sintering of the Pt nanoparticles happen after NaBH4 treatment. Results from the catalytic combustion of toluene indicate that the performance of the NaBH4‐treated catalyst can be further improved by combination with air pretreatment.
Cell Penetrating Synthetic Antimicrobial Peptides (SAMPs) Exhibiting Potent and Selective Killing of Mycobacterium by Targeting Its DNA
Authors: Sharma Aashish , Pohane Amol Arunrao , Bansal Sandhya , Bajaj Avinash , Jain Vikas , Srivastava Aasheesh
Published: January 2015

Naturally occurring antimicrobial peptides (AMPs) are powerful defence tools to tackle pathogenic microbes. However, limited natural production and high synthetic costs in addition to poor selectivity limit large‐scale use of AMPs in clinical settings. Here, we present a series of synthetic AMPs (SAMPs) that exhibit highly selective and potent killing of Mycobacterium (minimum inhibitory concentration <20 μg mL−1) over E. coli or mammalian cells. These SAMPs are active against rapidly multiplying as well as growth saturated Mycobacterium cultures. These SAMPs are not membrane‐lytic in nature, and are readily internalized by Mycobacterium and mammalian cells; whereas in E. coli, the lipopolysaccharide layer inhibits their cellular uptake, and hence, their antibacterial action. Upon internalization, these SAMPs interact with the unprotected genomic DNA of mycobacteria, and impede DNA‐dependent processes, leading to bacterial cell death.
N‐Annulated Perylene‐Substituted and Fused Porphyrin Dimers with Intense Near‐Infrared One‐Photon and Two‐Photon Absorption
Authors: Luo Jie , Lee Sangsu , Son Minjung , Zheng Bin , Huang Kuo‐Wei , Qi Qingbiao , Zeng Wangdong , Li Gongqiang , Kim Dongho , Wu Jishan
Published: January 2015

Fusion of two N‐annulated perylene (NP) units with a fused porphyrin dimer along the S0–S1 electronic transition moment axis has resulted in new near‐infrared (NIR) dyes 1 a/1 b with very intense absorption (ε>1.3×105 M−1 cm−1) beyond 1250 nm. Both compounds displayed moderate NIR fluorescence with fluorescence quantum yields of 4.4×10−6 and 6.0×10−6 for 1 a and 1 b, respectively. The NP‐substituted porphyrin dimers 2 a/2 b have also been obtained by controlled oxidative coupling and cyclodehydrogenation, and they showed superimposed absorptions of the fused porphyrin dimer and the NP chromophore. The excited‐state dynamics of all of these compounds have been studied by femtosecond transient absorption measurements, which revealed porphyrin dimer‐like behaviour. These new chromophores also exhibited good nonlinear optical susceptibility with large two‐photon absorption cross‐sections in the NIR region due to extended π‐conjugation. Time‐dependent density functional theory calculations have been performed to aid our understanding of their electronic structures and absorption spectra.
Twisted Baskets
Authors: Hermann Keith , Pratumyot Yaowalak , Polen Shane , Hardin Alex M. , Dalkilic Erdin , Dastan Arif , Badjić Jovica D.
Published: January 2015

A preparative procedure for obtaining a pair of twisted molecular baskets, each comprising a chiral framework with either right ((P)‐1syn) or left ((M)‐1syn) sense of twist and six ester groups at the rim has been developed and optimized. The racemic (P/M)‐1syn can be obtained in three synthetic steps from accessible starting materials. The resolution of (P/M)‐1syn is accomplished by its transesterification with (1R,2S,5R)‐(−)‐menthol in the presence of a TiIV catalyst to give diastereomeric 8P and 8M. It was found that dendritic‐like cavitands 8P and 8M, in CD2Cl2, undergo self‐inclusion (1H NMR spectroscopy) with a menthol moiety occupying the cavity of each host. Importantly, the degree of inclusion of the menthol group was (1H NMR spectroscopy) found to be greater in the case of 8P than 8M. Accordingly, it is suggested that different folding characteristic of 8P and 8M ought to affect the physicochemical characteristics of the hosts to permit their effective separation by column chromatography. The absolute configuration of 8P/8M, encompassing right‐ and left‐handed “cups”, was determined with the exciton chirality method and also verified in silico (DFT: B3LYP/TZVP). Finally, the twisted baskets are strongly fluorescent due to three naphthalene chromophores, having a high fluorescence quantum yield within the rigid framework of 8P/8M.
A Hetero‐Bifunctional Spacer for the Smart Engineering of Carbon‐Based Nanostructures
Authors: Tuci Giulia , Luconi Lapo , Rossin Andrea , Baldini Francesco , Cicchi Stefano , Tombelli Sara , Trono Cosimo , Giannetti Ambra , Manet Ilse , Fedeli Stefano , Brandi Alberto , Giambastiani Giuliano
Published: January 2015

Efforts have been made in recent years to develop novel functionalisation protocols aimed at imparting multimodality and improved properties to complex carbon‐based nanostructures. The incorporation of cleavable bonds to the nanomaterial surface for the controlled release (or exchange) of specific molecules under appropriate chemical and biological settings is relatively unexplored. The design and synthesis of a hetero‐bifunctional linker joining a “cleavable” disulfide moiety for the covalent anchoring of a wide range of thiol end‐capped (bio)molecules and a “clickable” terminal acetylene group is described. The strategy is based on the well‐established copper‐mediated acetylene–azide coupling reaction between the acetylene linker and single‐walled carbon nanotubes decorated with phenylazido pendant arms. As a result, easily “post‐derivatisable” and traceable nanostructured platforms containing a linking group potentially available for a wide range of biological probes are prepared and completely characterised.
Cytopathology: Why did it take so long to thrive?
Authors: Wright James R.
Published: January 2015

Lionel S. Beale of London made some of the earliest contributions to Cytopathology in the 1850–1860s. Cytopathology then experienced a 60+ year hiatus during which few advances were made. In 1927, Londoner Leonard S. Dudgeon published his wet film method for rapid intraoperative diagnosis and in 1928 Greek‐American George Papanicolaou and Romanian Aurel A. Babeş independently discovered that cervical cancer can be diagnosed using vaginal smears; these were huge advancements. Yet, there was another hiatus where little progress was made which lasted until the publications of Papanicolaou and Trout in the early 1940s. After that, the field of exfoliative Cytopathology immediately flourished. None of the standard histories of Cytopathology explain these two gaps. Primary and secondary historical sources were examined to explain this pattern. The author concludes that the first hiatus is explained by the 19th Century pathology establishment's strong opposition to the doctrine of the uniqueness of cancer cells that was being pushed by only a few maverick pathologists; in fact, for many mainstream pathologists, cancer was rigidly defined by cell behavior (metastases and invasion) and not cell morphology well into the 20th Century. Biopsy‐based diagnosis faced similar opposition but advanced more rapidly as it was possible to examine increased numbers of cells in a pattern that partially maintained their normal adjacencies and architecture. The second hiatus is explained by economic pressures supporting intraoperative frozen section diagnoses and, in the instance of vaginal smears, the embryonic state of the public campaign supporting the importance of early cancer diagnosis. Diagn. Cytopathol. 2015;43:257–263. © 2015 Wiley Periodicals, Inc.
Adolescents’ internalizing and externalizing problems predict their affect‐specific HPA and HPG axes reactivity
Authors: Han Georges , Miller Jonas G. , Cole Pamela M. , Zahn‐Waxler Carolyn , Hastings Paul D.
Published: January 2015

We examined psychopathology‐neuroendocrine associations in relation to the transition into adolescence within a developmental framework that acknowledged the interdependence of the HPA and HPG hormone systems in the regulation of responses to everyday affective contexts. Saliva samples were collected during anxiety and anger inductions from 51 young adolescents (M 13.47, SD = .60 years) to evaluate cortisol, DHEA, and testosterone responses. Internalizing and externalizing problems were assessed at pre‐adolescence (M = 9.27, SD = .58 years) while youths were in elementary school and concurrently with hormones in early adolescence. Externalizing problems from elementary school predicted adolescents’ reduced DHEA reactivity during anxiety induction. Follow up analyses simultaneously examining the contributions of elementary school and adolescent problems showed a trend suggesting that youths with higher levels of internalizing problems during elementary school eventuated in a profile of heightened DHEA reactivity as adolescents undergoing anxiety induction. For both the anxiety and the anger inductions, it was normative for DHEA and testosterone to be positively coupled. Adolescents with high externalizing problems but low internalizing problems marshaled dual axes co‐activation during anger induction in the form of positive cortisol‐testosterone coupling. This is some of the first evidence suggesting affective context determines whether dual axes coupling is reflective of normative or problematic functioning in adolescence. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 769–785, 2015.
Postweaning isolation affects responses to incentive contrast in adulthood
Authors: Cuenya Lucas , Mustaca Alba , Kamenetzky Giselle
Published: January 2015

Adolescence is a time involving a series of changes in the use of appetitive reinforcers like food, as well as neuroendocrine changes like those taking place in the mesolimbic dopamine function. Social isolation from postnatal day 21 to 36 in rats leads to behavioral and neurophysiological alterations such as increased consumption of appetitive reinforcers. The work is focused on studying how exposure to chronic stress induced by social isolation during adolescence can have a long‐lasting effect on responses to reinforcement shifts in adulthood. Two experiments were performed in rats in order to analyze the effect of adolescent isolation on the responses to unanticipated shifts in reinforcement during adulthood, in reinforcement devaluation (32–4% of sucrose solution), increase (4–32% of sucrose solution), and extinction (32–0% of sucrose solution) procedures. Adolescent isolation intensified the intake response resulting from a reinforcement increase (i.e., greater positive contrast), but had no effect on the response to reinforcement devaluation and omission. The implications of this procedure are discussed, along with the underlying behavioral and neurochemical mechanisms. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 177–188, 2015.
Development of high‐performance shake tables using the hierarchical control strategy and nonlinear control techniques
Authors: Yang T. Y. , Li Kang , Lin Jian Yuan , Li Yuanjie , Tung D. P.
Published: January 2015

Conventional shake tables employ linear controllers such as proportional‐integral‐derivative or loop shaping to regulate the movement. However, it is difficult to tune a linear controller to achieve accurate and robust tracking of different reference signals under payloads. The challenges are mainly due to the nonlinearity in hydraulic actuator dynamics and specimen behavior. Moreover, tracking a high‐frequency reference signal using a linear controller tends to cause actuator saturation and instability. In this paper, a hierarchical control strategy is proposed to develop a high‐performance shake table. A unidirectional shake table is constructed at the University of British Columbia to implement and evaluate the proposed control framework, which consists of a high‐level controller and one or multiple low‐level controller(s). The high‐level controller utilizes the sliding mode control (SMC) technique to provide robustness to compensate for model nonlinearity and uncertainties experienced in experimental tests. The performance of the proposed controller is compared with a state‐of‐the‐art loop‐shaping displacement‐based controller. The experimental results show that the proposed hierarchical shake table control system with SMC can provide superior displacement, velocity and acceleration tracking performance and improved robustness against modeling uncertainty and nonlinearities. Copyright © 2015 John Wiley & Sons, Ltd.
Carbon flux and landscape evolution in epigenic karst aquifers modeled from geochemical mass balance
Authors: Florea Lee J.
Published: January 2015

This paper considers the contributions of epigenic karst processes as a major element of the carbon cycle and a significant agent of landscape evolution. Geochemical models developed from monitoring data and water samples are used to estimate the variation and magnitude of dissolved inorganic carbon (DIC) flux in karst landscapes at several scales, from local to global. At the local scale, the Cumberland River watershed of southeast Kentucky, these geochemical models are also used to evaluate the potential role of sulfur in the production of DIC and to compute an estimated rate of landscape erosion.

Geochemical modeling using ionic species and modeled discharge reveal a variable rate of DIC flux driven by large fluctuations in calcite saturation and discharge. Ratios of reaction products and principal component analyses (PCA) suggest that some bedrock dissolution may be driven by the oxidation of reduced sulfur derived from brines entrained into the karst aquifers. Over the 3730 km2 of carbonate exposure in the Cumberland River, 25.8–62.4 Gg/yr of carbon dioxide (CO2) is conveyed from the atmosphere through the dissolution of carbonate. At the global scale, this translates to 123–296 Tg/yr of CO2 delivered by karst processes into the aqueous system.

The bedrock portion of DIC equates to a flux of 32.6 ± 2.6 m3 – 35.2 ± 2.8 m3 of bedrock during the period of study of which 29% was dolomite. This translates to a landscape erosion rate of 13.1–17.9 mm/ka in the 3.45–4.32 km2 of carbonate exposure in the studied watershed. Based upon 16+ km of cave survey data spanning a vertical range of 72 to 75 m above base level, this suggests that cave development in the watershed spans the Plio‐Pleistocene. Using the modeled erosion rates, the ages of cave levels, 4.03–5.71, 3.08–4.56, 1.57–2.43, 1.01–1.67, 0.45–0.91, and < 0.45 Ma, are in good agreement with regional studies of Plio‐Pleistocene landscape evolution in the Appalachian Lowland Plateaus. Copyright © 2015 John Wiley & Sons, Ltd.
The use of nutrient‐optimizing/cost‐minimizing software to develop ready‐to‐use therapeutic foods for malnourished pregnant women in Mali
Authors: Bechman Allison , Phillips Robert D. , Chen Jinru
Published: January 2015

Malnutrition affects people of all ages in many countries in the developing world. One treatment for malnutrition is the intervention involving ready‐to‐use therapeutic foods (RUTFs). This study developed RUTFs for pregnant women in Mali using formulation computer software and largely local, plant‐based ingredients. Mali has the world's second highest birth rate and infant mortality rate. Nutrient profiles of possible ingredients and their prices from 2004 to 2009 were entered into the software. Computer‐selected ingredients included peanuts, cowpeas, and millet as well as rice or barley koji (sources of α‐amylase and ingredients). Components of the six selected formulations were milled, hydrolyzed with koji α‐amylase, and heated at 121°C for 15 min. The contents of protein, fat, ash, fiber, carbohydrates, amino acid, and energy of dehydrated products were determined and compared with software‐predicted values. Actual and predicted values were comparable: the protein content was 1.45–2.04% higher, and ash content was 0.60–0.89% higher than the predicted values, while the fat content was 0.18–0.88% lower, the lysine content was 0.17–0.25% lower, and fiber content was 0.16% lower to 2.06% higher than the predicted values. The difference in actual and predicted energy levels were 14.8–22.2%. The amount of RUTF needed to meet the requirement of most limiting nutrients, lysine and energy, ranged from 2620 to 3002 g. The costs for producing the RUTFs were substantially lower than importing commercial RUTFs even with increased ingredient prices in Mali from 2004 to 2009.
Influence of extraction techniques on antioxidant properties and bioactive compounds of loquat fruit (Eriobotrya japonica Lindl.) skin and pulp extracts
Authors: Delfanian Mojtaba , Esmaeilzadeh Kenari Reza , Sahari Mohammad Ali
Published: January 2015

In this study, the bioactive compounds of loquat fruit (Eriobotrya japonica Lindl.) skin and pulp extracted by two extraction methods (solvent and ultrasound‐assisted) with three solvents (ethanol, water and ethanol–water) were compared to supercritical fluid extraction. The antioxidant activities of skin and pulp extracts were evaluated and compared to tertiary butylhydroquinone (TBHQ) using 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH˙) radical scavenging, β‐carotene bleaching, and the Rancimat assays. In DPPH assay solvent extracts of skin by ethanol (SSE) and ethanol–water (SSEW) showed strong inhibitory activity. The SSEW also showed the highest inhibition percentage of 85.58% by the β‐carotene bleaching assay and longest induction time of 4.78 h by the Rancimat method. The large amount of tocopherols and phenolics contained in the skin extract may cause its strong antioxidant ability. The results indicated that the solvent extraction with ethanol–water produced the maximum extraction yield of phenolic and tocopherol compounds from loquat fruit skin and pulp. Furthermore, solvent extraction was the most effective in antioxidant activity of the extracts compared to other extraction techniques.
Inhibition of IL‐6 signaling significantly reduces primary tumor growth and recurrencies in orthotopic xenograft models of pancreatic cancer
Authors: Goumas Freya A. , Holmer Reinhild , Egberts Jan‐Hendrik , Gontarewicz Artur , Heneweer Carola , Geisen Ulf , Hauser Charlotte , Mende Maria‐Margarete , Legler Karen , Röcken Christoph , Becker Thomas , Waetzig Georg H. , Rose‐John Stefan , Kalthoff Holger
Published: January 2015

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human tumors, with radical surgical resection as the only curative treatment option. However, resection is only possible in a small fraction of patients, and about 80% of the patients develop recurrencies. PDAC development is facilitated by the cytokine interleukin‐6 (IL‐6), which acts via classic and trans‐signaling. Both pathways are inhibited by the anti‐IL‐6‐receptor antibody tocilizumab, whereas the fusion protein sgp130Fc specifically blocks trans‐signaling. Here, we show that conservative or adjuvant therapy with both inhibitors reduces tumor growth in an orthotopic model of human Colo357 cells in SCID/bg mice. In the conservative setting, median primary tumor weight was reduced 2.4‐fold for tocilizumab and 4.4‐fold for sgp130Fc. sgp130Fc additionally led to a decrease in microvessel density, which was not observed with tocilizumab. In the adjuvant therapeutic setting after surgical resection of the primary tumor, treatment with tocilizumab or sgp130Fc decreased the local recurrence rate from 87.5% in the control group to 62.5 or 50%, respectively. Furthermore, the median weight of the local recurrent tumors was clearly diminished, and both inhibitors reduced the number of distant metastases. A significant reduction of tumor weight and metastases—comparable to gemcitabine treatment—was also observed with both inhibitors in another model using the poorly differentiated PancTuI cells. Our findings demonstrate the inhibition of IL‐6 as a new treatment option in PDAC.