bluuebunny/crossref_metadata_2025 huggingface dataset:
Zum Trag‐ und Erwärmungsverhalten von Verbundstützen mit massivem Stahlkern im Brandfall
Authors: Schaumann Peter , Kleibömer Inka
Published: May 2015

Ausbetonierte Hohlprofilstützen mit massiven Einstellprofilen stellen eine attraktive Möglichkeit dar, schlanke Stützen auch bei hohen Lasten zu realisieren und gleichzeitig hohe Anforderungen an den Feuerwiderstand zu erfüllen. Das Tragverhalten im Brandfall unterscheidet sich dabei grundlegend von dem anderer ausbetonierter Hohlprofilstützen, die bei gleicher Querschnittsfläche deutlich geringere Lasten abtragen. Dieser Beitrag behandelt Ergebnisse eines Forschungsprojektes, in dem das Tragverhalten einer runden Verbundstütze mit massivem Stahlkern im Brandfall experimentell untersucht wurde. Nach Erreichen der Feuerwiderstandsklasse R 90 wurde die Stütze bis zum Erreichen der Traglast belastet. Im Zuge der Untersuchungen wurde die Entwicklung der Temperaturen im Querschnitt ermittelt und den Ergebnissen numerisch ermittelter Temperaturfeldberechnungen gegenübergestellt.

Thermal and structural response of concrete‐filled tubular columns with massive steel core in case of fire

Concrete‐filled tubular columns with embedded massive steel core represent an attractive constructional possibility to design slender columns that are both resisting high loads and fulfil requirements concerning the fire resistance. The structural behaviour in case of fire thereby differs from the typical behaviour of concrete‐filled tubular columns without steel core, which carry remarkably lower loads. In the following paper, the thermal and mechanical behaviour of a circular composite column with embedded massive steel core is investigated experimentally. After achieving the fire resistance class R 90, the column was loaded up to failure and thus the residual bearing capacity was ascertained. Furthermore, the measurement of temperatures within the individual parts of the cross‐section was another aspect of the experimental investigations. Those data are additionally compared to numerically calculated temperatures.
Interaktionen zwischen Abdichtungsbauwerk und Wirtsgestein im Steinsalz
Authors: Stahlmann Joachim , Missal Christian , Gährken Andreas
Published: May 2015

Bei der Planung von Tiefen‐ oder Endlagern für radioaktive Abfälle wird angestrebt, den Zutritt von Wässern oder Lösungen langfristig zu verhindern, um das Schutzziel über Tage zu erreichen. Da im Fall einer Worst‐case‐Betrachtung der Zutritt nicht vollständig ausgeschlossen werden kann, sind die Zugangsstrecken zu den Einlagerungsbereichen abzudichten. Die Funktion wird im Wesentlichen durch die Interaktion zwischen Wirtsgestein und Abdichtungsbauwerk bestimmt. Insbesondere sind die Auflockerungszone im konturnahen Bereich, die Kontaktzone, Spannungsumlagerungen im Gebirge sowie die Kriecheigenschaften des Gebirges abdichtungsrelevant. Zusätzlich sind die Baustoffeigenschaften des Dammes zu berücksichtigen: Die Abkühlphase nach dem Abbindeprozess und autogenes Schwinden führen zu einer Spaltbildung zwischen Abdichtungsbauwerk und Wirtsgestein. Dieser Spalt ist für die kurzfristige Funktionsfähigkeit zu verpressen, langfristig kann das aufkriechende Gebirge eine ausreichend geringe Permeabilität gewährleisten. Es zeigt sich jedoch, dass die Übertragbarkeit der Modellvorstellungen aus dem Erfahrungshorizont des Bergbaus und des Bauingenieurwesens, auch im Hinblick auf die möglichen Fluidwegigkeiten, noch zu hinterfragen ist.

Interaction between sealing structure and host rock in rock salt

During the development of radioactive waste disposal it is intended to prevent the inflow of water and solution over a long period of time to reach the safety objective at the surface. As the inflow cannot be completely excluded when considering a worst case scenario, the access drifts towards the emplacement chambers have to be sealed. This function is primarily influenced by the interaction between the host rock and the sealing structure. The excavation damaged zone close to the contour, contact zone, stress redistribution in the host rock and the creeping capacity of the host rock are particularly relevant for the sealing. In addition, the characteristics of the sealing structure's building materials have to be considered: the cooling phase after the setting process and autogenous shrinkage lead to the development of gaps between the sealing structure and the host rock. These gaps have to be injected in order to reach a short‐term operability, while the long‐term low permeability can be provided by the creeping host rock. It became clear that the portability of the model concepts based on the experiences in mining and civil engineering have to be questioned, especially with regards to possible fluid flow.
Thermische Einwirkungen natürlicher Brände auf Bauteile und Tragwerke
Authors: Riese Olaf , Zehfuß Jochen
Published: May 2015

Die außergewöhnliche Bemessungssituation Brand als Lasteinwirkung auf Bauteile und Tragwerke ist in DIN EN 1991‐1‐2:2010‐12, Eurocode 1: Einwirkungen auf Tragwerke – Teil 1‐2: Allgemeine Einwirkungen – Brandeinwirkungen auf Tragwerke geregelt. Im zugehörigen Nationalen Anhang DIN EN 1991‐1‐2/NA werden die national festzulegenden Parameter bzw. nationale Festlegungen sowie die Anwendung informativer Anhänge für Deutschland definiert. Neben der Einheits‐Temperaturzeitkurve (ETK) als standardisierte thermische Einwirkung werden in DIN EN 1991‐1‐2 und zugehörigem Nationalen Anhang auch Naturbrandmodelle geregelt, mit denen die thermischen Einwirkungen leistungsorientiert in Abhängigkeit der vorhandenen Brandlasten, Ventilationsverhältnisse, Brandraumgeometrie und thermischen Eigenschaften der Umfassungsbauteile berechnet werden können. In der Musterliste der Technischen Baubestimmungen von März 2014 werden Randbedingungen für die Anwendung der Naturbrandverfahren beschrieben. Im Rahmen dieses Aufsatzes werden die zur Ermittlung der thermischen Einwirkung mit Naturbrandmodellen zugrunde zu legenden Brandszenarien und Bemessungsbrände dargestellt und auf deren Eignung und sinnvollen Anwendungsbereich eingegangen.

Thermal actions of components and structures exposed to natural fires

The exceptional case of fire load on construction parts and structures as action for building components is regulated by DIN EN 1991‐1‐2: 2010‐12, Eurocode 1: Actions on structures – Part 1‐2: General actions – fire actions on structures. In the National Annex DIN EN 1991‐1‐2/NA the national determined parameters and national requirements as well as the application of informative annex for Germany are defined. The DIN EN 1991‐1‐2 and the associated National Annex regulate the standard temperature‐time curve (ETK) as standardized thermal load and furthermore natural fire models which can be used for performance based fires safety design considering the actual fire loads, ventilation conditions, geometry of fire room and thermal properties of the structural components. In the Musterliste der Technischen Baubestimmungen of March 2014 boundary conditions are described for the application of natural fire method. This paper shows fire scenarios and design fires for determination of the thermal load with natural fire models and their suitability and practicable application.
Vorspannung bei Onshore‐Windenergieanlagen
Authors: Gläser Christian , Puttendörfer Niklas , Brockmann Sven , Hartwig Thomas
Published: May 2015

Mit steigender Bedeutung der Windkraft und Weiterentwicklung der Turbinen werden höhere Türme für Windenergieanlagen erforderlich. Verbunden damit ergeben sich Änderungen in der Bauweise der Türme. Abhängig vom verwendeten Turmtyp werden die Fundamente unterschiedlich ausgebildet. Bei Stahltürmen werden Stahlteile oder vorgespannte Ankerbolzen einbetoniert, während für den Beton‐Beton‐Anschluss bei Spannbeton‐ und Hybridtürmen andere vorgespannte Lösungen Anwendung finden. Bis vor wenigen Jahren kamen in Deutschland bei vorgespannten Türmen nur Spannglieder mit nachträglichem Verbund zum Einsatz. Weiterentwicklungen haben dazu geführt, dass jetzt auch weltweit Spannbeton‐ und Hybridtürme mit externen Spanngliedern vorgespannt werden. Auch wenn der grundsätzliche Aufbau der Spannglieder ähnlich wie im Brückenbau sein kann, muss die Anwendbarkeit für die abweichenden Randbedingungen im Turm einer Windenergieanlage nachgewiesen sein.

Bei der Vielzahl der weltweit ausgeführten Anlagen ist es nicht ausgeblieben, dass aufgrund von Ausführungsfehlern oder während der Bemessung nicht berücksichtigter Erkenntnisse die Verstärkung vorhandener Konstruktionen erforderlich werden kann. Im vorliegenden Artikel wird die Instandsetzung eines Fundaments beschrieben, bei dem infolge ursprünglich zu niedriger Betonfestigkeit durch die Umschnürung des Fundaments mittels Spanngliedern aktiv ein dreiaxialer Spannungszustand erzeugt wird, der die vertikale Druckfestigkeit des Fundaments erhöht.

Post‐Tensioning for Onshore‐Wind Energy Plants – From New Construction to retrofitting of existing structures

With increasing importance of wind power and development of stronger turbines higher towers for wind energy are required. Related to this, changes in the design of the towers are necessary. Depending on the used tower type foundations are designed differently. While in a steel tower steel parts or bolts are cast in the concrete, prestressed solutions can be used for the concrete‐concrete connection in post‐tensioned concrete and hybrid towers. While a few years ago in Germany only bonded tendons were used for post‐tensioned towers, further developments have globally led to stressing concepts using external tendons in post‐tensioned concrete and hybrid towers. Although the basic layout of the tendons may be similar to tendons used in bridge construction, the applicability of the different boundary conditions in the wind‐tower has to be verified.

With the multitude of running plants it cannot completely be prevented that failures during execution or factors not considered during design makes it necessary to strengthen existing towers. In this article, retrofitting of a foundation is described in which due to originally lower concrete strength by the confinement of the foundation an actively triaxial stress state is generated by tendons, which increases the vertical compressive strength of the foundation.
Stabilitätsverhalten von schlanken Wandscheiben aus Normal‐ und Ultrahochleistungsbeton
Authors: Lechner Thomas , Fischer Oliver
Published: May 2015

Die Entwicklung und Erforschung des Ultrahochleistungsbetons hat dazu geführt, dass es heute vorteilhaft ist, viele klassische Betonbauteile aus diesem innovativen Werkstoff herzustellen. Für Wandscheiben bedeutet dies, dass sich die Dicke aufgrund der hohen Druckfestigkeit reduzieren lässt, während sich die Dauerhaftigkeit infolge der geringen Porosität erhöht. Da Wandscheiben aus Ultrahochleistungsbeton im Vergleich zu Wänden aus Normalbeton bei gleicher Querschnittstragfähigkeit deutlich größere Schlankheiten aufweisen können, gewinnt das Stabilitätsverhalten entsprechend an Bedeutung. Der vorliegende Beitrag beschreibt Untersuchungen zum Stabilitätsverhalten von Wandscheiben, die am Lehrstuhl für Massivbau der Technischen Universität München (TUM) durchgeführt wurden. Der Forschungsschwerpunkt lag dabei auf zweiseitig gehaltenen Scheiben aus unbewehrtem Normalbeton sowie faserbewehrtem Ultrahochleistungsbeton. An diesen wurden experimentelle und numerische Untersuchungen zum Trag‐ und Verformungsverhalten durchgeführt. Nachfolgend werden die Ergebnisse dieser Untersuchungen sowie ein Ingenieurmodell zur Berechnung der maßgebenden Stabilitätslasten von schlanken, zweiseitig gehaltenen Scheiben vorgestellt.

Load bearing behavior and stability of slender wall panels made of normal strength and ultra‐high performance concrete.

Following more than one decade of theoretical and experimental research on ultra‐high performance concrete (UHPC) today there is a series of possible applications to efficiently utilize this new and innovative material in load‐bearing structures. One example are walls and wall panels respectively, the thickness of which may be decisively reduced thanks to the high compressive strength, leading to increasingly slender structures being more sensitive in terms of stability. The present paper describes theoretical and experimental investigations on the load‐bearing and buckling behavior of normal strength and UHPC wall panels being currently performed at the chair of concrete and masonry structures of TUM. In doing so, exemplary results of these investigations are presented and discussed and an engineering model determining critical loads of slender walls is derived.
Posterior predictive checking of multiple imputation models
Authors: Nguyen Cattram D. , Lee Katherine J. , Carlin John B.
Published: May 2015

Multiple imputation is gaining popularity as a strategy for handling missing data, but there is a scarcity of tools for checking imputation models, a critical step in model fitting. Posterior predictive checking (PPC) has been recommended as an imputation diagnostic. PPC involves simulating “replicated” data from the posterior predictive distribution of the model under scrutiny. Model fit is assessed by examining whether the analysis from the observed data appears typical of results obtained from the replicates produced by the model. A proposed diagnostic measure is the posterior predictive “p‐value”, an extreme value of which (i.e., a value close to 0 or 1) suggests a misfit between the model and the data.

The aim of this study was to evaluate the performance of the posterior predictive p‐value as an imputation diagnostic. Using simulation methods, we deliberately misspecified imputation models to determine whether posterior predictive p‐values were effective in identifying these problems. When estimating the regression parameter of interest, we found that more extreme p‐values were associated with poorer imputation model performance, although the results highlighted that traditional thresholds for classical p‐values do not apply in this context. A shortcoming of the PPC method was its reduced ability to detect misspecified models with increasing amounts of missing data. Despite the limitations of posterior predictive p‐values, they appear to have a valuable place in the imputer's toolkit. In addition to automated checking using p‐values, we recommend imputers perform graphical checks and examine other summaries of the test quantity distribution.
Site‐Specific Modification of the 6‐Amino Group of Adenosine in RNA by an Interstrand Functionality‐Transfer Reaction With an S‐Functionalized 4‐Thiothymidine
Authors: Oshiro Ikuya , Jitsuzaki Daichi , Onizuka Kazumitsu , Nishimoto Atsushi , Taniguchi Yosuke , Sasaki Shigeki
Published: May 2015

Non‐natural RNA modifications have been widely used to study the function and structure of RNA. Expanding the study of RNA further requires versatile and efficient tools for site‐specific RNA modification. We recently established a new strategy for the site‐specific modification of RNA based on a functionality‐transfer reaction between an oligodeoxynucleotide (ODN) probe and an RNA substrate. 2′‐Deoxy‐6‐thioguanosine was used to anchor the transfer group, and the 4‐amino group of cytosine or the 2‐amino group of guanine was specifically modified. In this study, 2′‐deoxy‐4‐thiothymidine was adopted as a new platform to target the 6‐amino group of adenosine. The (E)‐pyridinyl vinyl keto transfer group was attached to the 4‐thioT in the ODN probe, and it was efficiently and specifically transferred to the 6‐amino group of the opposing adenosine in RNA in the presence of CuCl2. This method expands the available RNA target sites for specific modification.
The impact of ruxolitinib treatment on inflammation‐mediated comorbidities in myelofibrosis and related neoplasms
Authors: Bjørn Mads Emil , Hasselbalch Hans Carl
Published: May 2015

Key clinical message

The inflammation‐mediated comorbidities in myelofibrosis (MF) and related neoplasms (MPNs) likely reflect the concurrent immune deregulation and systemic inflammatory nature of the MPNs, emphasizing the link between chronic systemic inflammation, immune deregulation, and the malignant clone. JAK1‐2 inhibitors in MF‐patients reduce constitutional symptoms and splenomegaly, but also taget autoimmune and inflammation‐mediated comorbidities.
Rhodium Nanoparticles as Precursors for the Preparation of an Efficient and Recyclable Hydroformylation Catalyst
Authors: Garcia Marco A. S. , Oliveira Kelley C. B. , Costa Jean C. S. , Corio Paola , Gusevskaya Elena V. , dos Santos Eduardo N. , Rossi Liane M.
Published: May 2015

Despite all the advances in the application of nanoparticle (NP) catalysts, they have received little attention in relation to the hydroformylation reaction. Herein, we present the preparation of a hydroformylation catalyst through the immobilization of air‐stable rhodium NPs onto a magnetic support functionalized with chelating phosphine ligands, which serves as an alternative to air‐sensitive precursors. The catalyst was active in hydroformylation and could be used in successive reactions with negligible metal leaching. The interaction between the rhodium NPs and the diphenylphosphine ligand was evidenced by an enhancement in the Raman spectrum of the ligand. Changes occurred in the Raman spectrum of the catalyst recovered after the reaction, which suggests that the rhodium NPs are precursors of active molecular species that are formed in situ. The supported catalyst was active for successive reactions even after it was exposed to air during the recycling runs and was easily recovered through magnetic separation.
Intramolecular Cooperative CC Bond Cleavage Reaction of 1,3‐Dicarbonyl Compounds with 2‐Iodoanilines to Give o‐(N‐Acylamino)aryl Ketones and Multisubstituted Indoles
Authors: Xing Qi , Lv Hui , Xia Chungu , Li Fuwei
Published: May 2015

A copper‐catalyzed CC bond cleavage reaction of 1,3‐dicarbonyl compounds with 2‐iodoanilines was developed. In this process, the ortho effect played an important role in the reactivity and a new reaction pathway that involved a (2‐aminophenyl)‐bis‐(1,3‐dicarbonyl) copper species was clearly observed by a time‐course HRMS analysis of the reaction mixture. Unlike the previous reports, both the nucleophilic and electrophilic parts of the 1,3‐dicarbonyl compound were coupled with 2‐iodoaniline by CC bond cleavage to form o‐(N‐acylamino)aryl ketones, which could be efficiently converted into multisubstituted indoles.
Tautomerization‐Mediated Molecular Switching Between Six‐ and Seven‐Membered Rings Stabilized by Hydrogen Bonding
Authors: Storch Golo , Spallek Markus J. , Rominger Frank , Trapp Oliver
Published: May 2015

1,3,4,6‐Tetraketones typically undergo keto–enol tautomerism forming bis‐enols stabilized by intramolecular hydrogen bonding in two six‐membered rings. However, 1,3,4,6‐tetraketones derived from the terpene ketone camphor and norcamphor exist as isomers with two distinguishable modes of intramolecular hydrogen bonding, namely, the formation of six‐ or seven‐membered rings. The structural requirements for this so far unknown behavior were investigated in detail by synthesis and comparison of structural analogues. Both isomers of such 1,3,4,6‐tetraketones were fully characterized in solution and in the solid state. Intriguingly, they slowly interconvert in solution by means of tautomerism–rotation cascades, as was corroborated by DFT calculations. The influence of temperature and complexation with the transition metals Pd, Rh, and Ir on the interconversion process was investigated.
The Guanidinium Unit in the Catalysis of Phosphoryl Transfer Reactions: From Molecular Spacers to Nanostructured Supports
Authors: Salvio Riccardo
Published: May 2015

Examples of guanidinium‐based artificial phosphodiesterases are illustrated in this review article. A wide set of collected catalytic systems are presented, from the early examples to the most recent developments of the use of this unit in the design of supramolecular catalysts. Special attention is dedicated to illustrate the operating catalytic mechanism and the role of guanidine/ium units in the catalysis. One or more of these units can act by themselves or in conjunction with other active units. The analogy with the mechanism of enzymatic systems is presented and discussed. In the last part of this overview, recent examples of guanidinophosphodiesterases based on nanostructured supports are reported, namely gold‐monolayer‐protected clusters and polymer brushes grafted to silica nanoparticles. The issue of the dependence of the catalytic performance on the preorganization of the spacer is tackled and discussed in terms of effective molarity, a parameter that can be taken as a quantitative measurement of this preorganization for both conventional molecular linker and nanosized supports.
Absolute Asymmetric Synthesis of a Tetrahedral Silver Complex
Authors: Björemark Per Martin , Olsson Susanne , Kokoli Theonitsa , Håkansson Mikael
Published: May 2015

Even though the isolation of tetrahedral stereoisomers usually presents a synthetic challenge, a highly enantioenriched tetrahedral silver complex could be easily accessed by either crystallization or Viedma ripening. The overall preparation may be regarded as an example of absolute asymmetric synthesis. Experimental results indicate that both crystallization and Viedma ripening follow a similar cluster‐controlled mechanism.
Hierarchical Interpolative Factorization for Elliptic Operators: Integral Equations
Authors: L. Ho Kenneth , Ying Lexing
Published: May 2015

This paper introduces the hierarchical interpolative factorization for integral equations (HIF‐IE) associated with elliptic problems in two and three dimensions. This factorization takes the form of an approximate generalized LU decomposition that permits the efficient application of the discretized operator and its inverse. HIF‐IE is based on the recursive skeletonization algorithm but incorporates a novel combination of two key features: (1) a matrix factorization framework for sparsifying structured dense matrices and (2) a recursive dimensional reduction strategy to decrease the cost. Thus, higher‐dimensional problems are effectively mapped to one dimension, and we conjecture that constructing, applying, and inverting the factorization all have linear or quasilinear complexity. Numerical experiments support this claim and further demonstrate the performance of our algorithm as a generalized fast multipole method, direct solver, and preconditioner. HIF‐IE is compatible with geometric adaptivity and can handle both boundary and volume problems.© 2016 Wiley Periodicals, Inc.
Unique morphologies of zinc oxide synthesized by thermal decomposition and co‐precipitation routes: Ultraviolet absorption and luminescence characteristics
Authors: Waqas Hassan , Salman Muhammad Saad , Riaz Asim , Riaz Naeem , Shabbir Saima
Published: May 2015

Two facile and efficient methods, to synthesize zinc oxide (ZnO) particles with different morphologies, have been reported here. Thermal decomposition route yielded micron sized irregular shaped ZnO particles. While co‐precipitation method rendered transparent flakes which then transformed to hexagonal discs with relatively more uniform size and shape. These hexagonal discs were further converted to the cone type morphology when hexamethylenetetramine was added in the precursor solution. However, spherical type ZnO nanoparticles were obtained by incorporating polyvinyl alcohol during co‐precipitation strategy. XRD confirmed the formation of wurtzite structure in all the samples. FTIR spectroscopy revealed the presence of ZnO characteristic peaks. Moreover, 3‐D directional growths and the presence of UV‐Vis broadband multi‐absorption peaks, and green to orange photoluminescence emissions confirmed the potential application of the synthesized ZnO particles in various piezoelectric and luminescence applications.

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EXPO software for solving crystal structures by powder diffraction data: methods and application
Authors: Altomare Angela , Corriero Nicola , Cuocci Corrado , Falcicchio Aurelia , Moliterni Anna , Rizzi Rosanna
Published: May 2015

Innovative methodologies, introduced in the software EXPO and working both in the reciprocal and in the direct space, can be successfully adopted for solving crystal structure by X‐ray powder diffraction data. The principles underlying these methodologies are summarized. Three representative examples of crystal structure solution of the peptides Z‐(Aib)2‐OH, Z‐(Aib)3‐O‐t‐Bu and Z‐(Aib)4‐OH are discussed in relation to their different degree of structure complexity.

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Highly efficient photocatalytic degradation of methyl orange and Rhodamine B by hierarchical BiOBr microspheres
Authors: Wang X. J. , Xu X. N. , Han Y. J. , Chen X. N.
Published: May 2015

Hierarchical BiOBr microspheres were successfully synthesized via a solvothermal method by using the diethylene glycol(DEG) as the solvent and soft‐template. The as‐obtained products were characterized by X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), N2 adsorption–desorption and UV–Vis diffuse reflectance spectroscopy(DRS) techniques. The formation mechanism for the growth of hierarchical BiOBr microspheres has been studied. The possible mechanism of photocatalysis has been discussed. Remarkably, the as‐prepared BiOBr microspheres has a large specific surface area, which can reach a maximum surface area of 55.9307 m2/g. In addition, the superior enhanced photocatalytic activities of BiOBr microspheres were evaluated by the photodegradation of methyl orange (MO) and Rhodamine B (RhB) under visible‐light illumination, which presented the efficiency up to 98.10% just within 50 min and 98.64% within 30 min, respectively. BiOBr microspheres can be a promising candidate as highly efficient photocatalyst for decompositing of organic contaminants for environmental remediation.
On the Origin of the Improvement of Electrodeposited MnOx Films in Water Oxidation Catalysis Induced by Heat Treatment
Authors: Khan Munirah , Xiao Jie , Zhou Fengling , Yablonskikh Mikhail , MacFarlane Douglas R. , Spiccia Leone , Aziz Emad F.
Published: May 2015

Manganese oxides (MnOx) are considered to be promising catalysts for water oxidation. Building on our previous studies showing that the catalytic activity of MnOx films electrodeposited from aqueous electrolytes is improved by a simple heat treatment, we have explored the origin of the catalytic enhancement at an electronic level by X‐ray absorption spectroscopy (XAS). The Mn L‐edge XA spectra measured at various heating stages were fitted by linear combinations of the spectra of the well‐defined manganese oxides—MnO, Mn3O4, Mn2O3, MnO2 and birnessite. This analysis identified two major manganese oxides, Mn3O4 and birnessite, that constitute 97 % of the MnOx films. Moreover, the catalytic improvement on heat treatment at 90 °C is related to the conversion of a small amount of birnessite to the Mn3O4 phase, accompanied by an irreversible dehydration process. Further dehydration at higher temperature (120 °C), however, leads to a poorer catalytic performance.
Magnesium Oxide Thin Films with Tunable Crystallographic Preferred Orientation via Aerosol‐Assisted CVD
Authors: Ponja Sapna D. , Parkin Ivan P. , Carmalt Claire J.
Published: May 2015

Magnesium oxide films are deposited on glass via aerosol‐assisted (AA)CVD. Depositions using magnesium acetate tetrahydrate in ethanol or methanol are carried out at 400, 500, and 600 °C. Films are analyzed by various methods. Growth rate, film thickness, and crystallite size increase with temperature, regardless of solvent. The films are crystalline and the crystallographic preferred orientation varies with solvent and temperature, allowing fine‐tuning for industrial applications. Solvent and temperature influence the surface morphology; films deposited using ethanol consist of small surface structures compared to the featureless morphology of methanol‐derived films. The refractive index of the films is 1.72 for methanol and 1.70 for ethanol systems.
Mediastinal granulomatous lymphadenitis in a population at risk for HIV and tuberculosis
Authors: De Wet Daniel R. , Wright Colleen A. , Schubert Pawel T. , Koegelenberg Coenraad F. N. , Louw Mercia , Diacon Andreas H.
Published: May 2015

Background

Granulomatous inflammation on transbronchial needle aspirates from mediastinal lymph nodes is an infrequent yet important finding. We determined associations between cytomorphological features and underlying aetiology in an area of high prevalence of HIV‐infection and tuberculosis.

Methods

We identified cases with granulomatous inflammation on mediastinal aspirates from January 2003 to July 2010. Cytomorphological features were evaluated and graded according to a simple and reproducible system including the presence, quality (discrete or vague), and number (≤5 or more) of granulomas as well as the presence of necrosis, lymphocytes, multinucleated giant cells, and neutrophils.

Results

In 81 patients (36 male, 9 HIV‐positive) the final diagnosis was tuberculosis in 37 (46%), sarcoidosis in 40 (49%), fibrosing mediastinitis in 1 (1%), and unknown in 3 (4%). The presence of necrosis (P < 0.001) and neutrophils (P = 0.05) was associated with tuberculosis and numerous discrete granulomas were associated with sarcoidosis (P = 0.03). All HIV‐positive patients were diagnosed with tuberculosis.

Conclusion

Granulomatous disease identified on TBNA from mediastinal lymph nodes is mostly associated with sarcoidosis and tuberculosis. Ancillary investigations for sarcoidosis are appropriate if numerous discrete granulomas are found. Tuberculosis must be excluded if necrosis and neutrophils are present and in HIV‐positive individuals, particularly in high‐burden areas of tuberculosis. Diagn. Cytopathol. 2015;43:696–700. © 2015 Wiley Periodicals, Inc.
Pleural‐based neuroblastoma‐like schwannoma: A case report with cytologic findings and review of literature
Authors: Adams Kristen , Liu Xuehui Susan , Akhtar Israh , Flowers Rhyne , Baliga Mithra
Published: May 2015

We report a rare case of a 45‐year‐old African American woman with Neuroblastoma‐like Schwannoma (Neurilemmoma) occurring in the posterior mediastinum as a pleural‐based mass noted on computed tomography (CT) scan.

A CT‐guided core biopsy of the mass was performed and core biopsy imprints were prepared during the procedure. A Diff‐Quik stain was performed for on‐site evaluation of specimen adequacy. The hematoxylin and eosin (H&E) staining was evaluated subsequently. Immunohistochemistry panels were applied to the same specimen.

The cytologic findings of the core biopsy imprints showed hypercellular smears with a predominance of small cells with atypical features including hyperchromatic, round nuclei and occasional nucleoli. Neurocytic rosettes were particularly appreciated on H&E stain. The immunohistochemical results exhibited strong and diffuse immunoreactivity for S‐100 and vimentin.

This case enriches the cytopathology literature by providing awareness of this tumor presenting as a posterior mediastinal mass. Diagn. Cytopathol. 2015;43:650–653. © 2015 Wiley Periodicals, Inc.
Transformation of graphene oxide by ferrous iron: Environmental implications
Authors: Wang Fanfan , Wang Fang , Gao Guandao , Chen Wei
Published: May 2015

Abiotic transformation of graphene oxide (GO) in aquatic environments can markedly affect the fate, transport, and effects of GO. The authors observed that ferrous iron (Fe[II])—an environmentally abundant, mild reductant—can significantly affect the physicochemical properties of GO (examined by treating aqueous GO suspensions with Fe2+ at room temperature, with doses of 0.032 mM Fe2+ per mg/L, 0.08 mM Fe2+ per mg/L, and 0.32 mM Fe2+ per mg/L GO). Microscopy data showed stacking of GO nanosheets on Fe2+ treatment. Spectroscopy evidence (X-ray diffraction, Fourier transform infrared transmission, Raman and X-ray photoelectron spectroscopy) showed significant changes in GO surface O-functionalities, in terms of loss of epoxy and carbonyl groups but increase of carboxyl group. The reduction mechanisms were verified by treating model organic molecules (styrene oxide, p-benzoquinone, and benzoic acid) resembling O-containing fragments of GO macromolecules with Fe2+. With sedimentation and adsorption experiments (using bisphenol A as a model contaminant), the authors demonstrated that Fe2+ reduced GOs still maintained relatively high colloidal stability, whereas their adsorption affinities were significantly enhanced. Thus, reduction of GO by mild reductants might be of greater environmental concerns than by stronger reducing agents (e.g., N2H4 and S2–), because the latter can result in too significant losses of surface O-functionalities and colloidal stability of GO. This interesting aspect should be given consideration in the risk assessment of GO. Environ Toxicol Chem 2015;34:1975–1982. © 2015 SETAC
The Pseudomonas Quinolone Signal (PQS)
Authors: Sams Thomas , Baker Ysobel , Hodgkinson James , Gross Jeremy , Spring David , Welch Martin
Published: May 2015

Pseudomonas aeruginosa is an opportunistic human pathogen that routinely appears near the top of public health threat lists worldwide. P. aeruginosa causes infections by secreting a wealth of exceptionally active exoproducts, leading to tissue damage. The synthesis of many of these virulence factors is now known to be under the control of the quorum sensing (QS) system. Over the last 15 years, the Pseudomonas quinolone signal (PQS) has been found to play a crucial role in QS by linking the two segments (las and rhl) of the P. aeruginosa N‐acylhomoserine lactone‐dependent QS signaling pathways. Herein, we present the discovery and elucidation of PQS signaling from a historical perspective, and also outline some of the outstanding research questions that still need to be addressed. Finally, we show how a better understanding of the biochemistry underpinning this pathway is leading to the development of new antimicrobial interventions with clear therapeutic potential.
Rainfall–Runoff Research on Upland Fields and A Comparison Of Kinematic Wave and Improved Tank Models
Authors: Chen Rong‐Song , Yang Kuo‐Hsien , Chang Shun‐Chun
Published: May 2015

Taiwan is a small, populous island. Because little flat land remains available for building, a trend in hillside development has recently been observed. During the storm season, especially during typhoons, heavy rainfall is common; however, the volume of rainfall is difficult to predict. Heavy precipitation causes flash floods as surface and groundwater levels overwhelm drainage systems. Thus people living on, or close to, hills are at risk of experiencing flooding with little warning.

We investigated two models to discuss their differences and impact of rainfall in upland locations. The tank model describes and simulates the hydrology of an area, and the kinematic wave model simulates rainfall at upland locations. We used two natural rainfall events that occurred in the Tai‐Chung basin as case studies for both models. We applied five statistical indexes, namely root mean squared error (RMSE), coefficient of efficiency (CE), percentage error of peak discharge (EQp), error in time to peak (ETp), and percentage error of total volume (EV) to evaluate and interpret hydraulic data and our simulation results. We determined both models to be applicable; the results showed the relative error in peak flow simulation for the upland tank model to be less than 10%. The total runoff forecasts for large‐scale typhoon rainfall exhibited large errors in both models. Less severe rainfall events produced lower percentage errors in both models.

The simulated hydrograph was compared with the measured hydrograph, and little difference was observed in the performance of the models. However, the simulation results of the kinematic wave model were slightly more favourable, possibly because the more complex wave model included more parameters representing physiographic factors, such as the river flow parameters P and K, equivalent roughness values of N, the average slope values, and the infiltration values, thus increasing the accuracy of the simulation. The upland tank model did not require complex physiographic factor parameters; instead, the Multistar‐Powell method was used to model the upland tank model parameters to produce a simulated hydrograph, yielding results no less favourable than those produced using the kinematic wave model. In the absence of comprehensive measured data and physiographic factors, the upland tank model has practical uses. Copyright © 2015 John Wiley & Sons, Ltd.
NHLBI state of the science symposium in therapeutic apheresis: Knowledge gaps and research opportunities in the area of hematology‐oncology
Authors: Karafin Matthew S. , Sachais Bruce S. , Connelly‐Smith Laura , Field Joshua J. , Linenberger Michael L. , Padmanabhan Anand
Published: May 2015

The National Heart Lung and Blood Institute (NHLBI) hosted a two‐day state of the science symposium on therapeutic apheresis in Bethesda, MD on November 28th‐29th, 2012. The purpose of the symposium was multifaceted, and included the following aims: (a) To discuss this state of research and key scientific questions in apheresis medicine; (b) To identify gaps in knowledge for relevant cardiovascular diseases, hematological and oncological diseases, infectious diseases and sepsis, renal diseases, and neurological diseases where there may be strong therapeutic rationale for the application of apheresis treatments; (c) To explore ways of coordinating therapeutic apheresis with other medical disciplines and treatment modalities; (d) To identify and prioritize the most important research questions to be answered in apheresis medicine; and (e) To offer NHLBI suggestions on how a structured research approach can be applied to the therapeutic apheresis research agenda in future years. The following document summarizes three such key proposals presented at the meeting for evaluating apheresis therapy for the treatment of pain in sickle cell disease, heparin induced thrombocytopenia, and leukostasis from acute myeloid leukemia. The challenges and limitations regarding apheresis therapy for each disease are discussed, and avenues for future investigation for each disease are outlined. J. Clin. Apheresis 31:38–47, 2016. © 2015 Wiley Periodicals, Inc.
Adverse local tissue reaction (ALTR) associated with corrosion products in metal‐on‐metal and dual modular neck total hip replacements is associated with upregulation of interferon gamma‐mediated chemokine signaling
Authors: Kolatat Kritti , Perino Giorgio , Wilner Gabrielle , Kaplowitz Elianna , Ricciardi Benjamin F. , Boettner Friedrich , Westrich Geoffrey H. , Jerabek Seth A. , Goldring Steven R. , Purdue P. Edward
Published: May 2015

Adverse local tissue reactions (ALTR) associated with tribocorrosion following total hip arthroplasty (THA) have become a significant clinical concern in recent years. In particular, implants featuring metal‐on‐metal bearing surfaces and modular femoral stems have been reported to result in elevated rates of ALTR. These tribocorrosion‐related tissue reactions are characterized by marked necrosis and lymphocytic infiltration, which contrasts sharply with the macrophagic and foreign body giant cell inflammation associated with polyethylene wear particle induced peri‐implant osteolysis. In this study, we characterize tribocorrosion‐associated ALTR at a molecular level. Gene expression profiling of peri‐implant tissue around failing implants identifies upregulation of numerous inflammatory mediators in ALTR, including several interferon gamma inducible factors, most notably the chemokines MIG/CXCL9 and IP‐10/CXCL10. This expression profile is distinct from that associated with polyethylene wear induced osteolysis, which is characterized by induction of markers of alternative macrophage activation, such as chitotriosidase (CHIT‐1). Importantly, MIG/CXCL9 and IP‐10/CXCL10 are also elevated at the protein level in the synovial fluid and, albeit more moderately, the serum, of ALTR patients, raising the possibility that these factors may serve as circulating biomarkers for the early detection of ALTR in at‐risk patients. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1487–1497, 2015.
Passive cigarette smoking changes the circadian rhythm of clock genes in rat intervertebral discs
Authors: Numaguchi Shumpei , Esumi Mariko , Sakamoto Mika , Endo Michiko , Ebihara Takayuki , Soma Hirotoki , Yoshida Akio , Tokuhashi Yasuaki
Published: May 2015

We aimed to elucidate the molecular changes in intervertebral discs (IVDs) caused by passive smoking. Rats were subjected to 8 weeks of passive smoking; thereafter, their lumbar vertebrae were harvested. The annulus fibrosus and cartilage endplate (AF/CEP) were harvested together, and the nucleus pulposus (NP) was isolated separately. The expression of 27,342 rat genes was analyzed. In 3 “nonsmoking” rats, 96 of 112 genes whose expression varied ≥10‐fold between the AF/CEP and NP were more highly expressed in the AF/CEP. With these differentially expressed genes, we uncovered novel AF/CEP and NP marker genes and indicated their possible novel functions. Although passive smoking induced less marked alteration in the gene expression profiles of both the AF/CEP and NP, multiple clock‐related genes showed altered expression. These genes were expressed with a circadian rhythm in IVD cells, and most genes showed a phase shift of −6 to −9 h induced by passive smoking. Some clock‐related genes showed abolished oscillation in the NP. Passive smoking also changed the expression levels of proteases and protease inhibitors and reduced the expression of NP marker genes. Thus, passive smoking induces changes in the circadian rhythm of a peripheral clock (IVD clock) that might be involved in molecular events related to IVD degeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:39–47, 2016.
Controlled release in hard to access places by poly(methyl methacrylate) microcapsules triggered by gamma irradiation
Authors: Kostrzewska Malgorzata , Ma Baoguang , Javakhishvili Irakli , Hansen Jens H. , Hvilsted Søren , Skov Anne L.
Published: May 2015

Gamma irradiation was investigated as a triggering stimulus for the activation of poly(methyl methacrylate) (PMMA) microcapsules. PMMA was exposed to varying doses of irradiation and analyzed by differential scanning calorimetry, size‐exclusion chromatography, and nuclear magnetic resonance. It was found that the glass transition temperature (Tg) of the polymer decreases at low irradiation doses. Additionally, Tg can be physically adjusted by adding a plasticizer, and both kinds of microcapsules were successfully prepared with non‐plasticized and plasticized PMMA shell. Finally, impermeable microcapsules were shown to become permeable after irradiation and release an encapsulated cross‐linker, which enables the remotely controlled formation of polydimethylsiloxanes in traditionally unavailable places. Therefore, the activation method has significant implications for industrial application. Copyright © 2015 John Wiley & Sons, Ltd.
Polymer matrix influence on stability of wood polymer composites
Authors: Porebska Renata , Rybak Andrzej , Kozub Barbara , Sekula Robert
Published: May 2015

The aim of the presented work is to show the influence of the various polymer matrices and the different amounts of the cellulose filler on the composites properties. Samples based on polypropylene, polystyrene, polyoxymethylene, acrylonitrile butadiene styrene, polyester resin, and polylactic acid with different contents of cellulose fibers were prepared by injection molding process. The mechanical and dielectric properties of these composites were studied in order to check whether investigated wood polymer composites fulfill requirements for their application in electrical devices. For all tested composites, a linear increase of modulus with cellulose content was observed. Addition of cellulose to the tested polymers significantly reduces strain at break. In the case of polypropylene and polyoxymethylene composites, the tensile strength increases with the content of the filler. For other materials, there is an inverse relationship, namely the addition of cellulose decreases the tensile strength. The electrical strength decrease was observed with increased cellulose content for the majority of the investigated composites. Polar groups incorporated by cellulose fibers have led to dielectric constant increase. Furthermore, aging of composites in mineral oil and evaluation of water uptake for wood–plastic samples were performed. Wood polymer composites have changed significantly after aging. The water diffusion coefficients were determined, and the significant influence of the amount of cellulose on the water absorption was shown. Copyright © 2015 John Wiley & Sons, Ltd.
A Descriptive and Historical Review of Bibliometrics with Applications to Medical Sciences
Authors: Thompson Dennis F. , Walker Cheri K.
Published: May 2015

The discipline of bibliometrics involves the application of mathematical and statistical methods to scholarly publications. The first attempts at systematic data collection were provided by Alfred Lotka and Samuel Bradford, who subsequently established the foundational laws of bibliometrics. Eugene Garfield ushered in the modern era of bibliometrics with the routine use of citation analysis and systematized processing. Key elements of bibliometric analysis include database coverage, consistency and accuracy of the data, data fields, search options, and analysis and use of metrics. A number of bibliometric applications are currently being used in medical science and health care. Bibliometric parameters and indexes may be increasingly used by grant funding sources as measures of research success. Universities may build benchmarking standards from bibliometric data to determine academic achievement through promotion and tenure guidelines in the future. This article reviews the history, definition, laws, and elements of bibliometric principles and provides examples of bibliometric applications to the broader health care community. To accomplish this, the Medline (1966–2014) and Web of Science (1945–2014) databases were searched to identify relevant articles; select articles were also cross‐referenced. Articles selected were those that provided background, history, descriptive analysis, and application of bibliometric principles and metrics to medical science and health care. No attempt was made to cover all areas exhaustively; rather, key articles were chosen that illustrate bibliometric concepts and enhance the reader's knowledge. It is important that faculty and researchers understand the limitations and appropriate uses of bibliometric data. Bibliometrics has considerable potential as a research area for health care scientists and practitioners that can be used to discover new information about academic trends, pharmacotherapy, disease, and broader health sciences trends.
H‐Rotoren: Vertikale Windräder
Authors: Brewer William D. , Zastrow Friedrich
Published: May 2015

Die etablierten konventionellen Windturbinen rotieren um eine horizontale Drehachse. Deshalb benötigen sie eine aufwendige Nachführung in die Windrichtung und meist ein Getriebe zwischen Rotor und Generator. Windenergieanlagen mit vertikaler Achse, sogenannte H‐Rotoren, sind dagegen deutlich einfacher aufgebaut. Sie sind robust, wartungsarm und laufen fast geräuschlos. Daher eignen sie sich für den Betrieb an entlegenen Orten in sogenannten Insellösungen, in lokalen Netzen, aber auch in Städten. Ihr Wirkungsgrad ist nicht prinzipiell geringer als bei herkömmlichen Anlagen. Fortschritte in Konstruktion und Steuerung lassen auf einen baldigen kommerziellen Durchbruch im Bereich der kleinen und mittleren Anlagen hoffen.