bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bonding properties and bulk modulus of M4AlC3 (M = V, Nb, and Ta) studied by first‐principles calculations
Authors: Du Y. L. , Sun Z. M. , Hashimoto H. , Tian W. B. 
Published: February 2009

AbstractWe have investigated the bonding properties and bulk modulus of M4AlC3 (M = V, Nb, and Ta) by first‐principles calculations. The calculated cohesive energy indicates the enhancement of bond strength of M4AlC3 as V is replaced by Nb and subsequently by Ta. This conclusion was further confirmed by the analysis of density of states of M4AlC3. The bulk modulus of M4AlC3 is found to be proportional to its corresponding binary compound MC. The hardness of M4AlC3 was discussed based on the relationship between the bulk modulus and hardness. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light‐emitting diode applications of colloidal CdSe/ZnS quantum dots embedded in TiO2–δ thin film
Authors: Kang Seung‐Hee , Huh Hoon‐Hoe , Son Kee‐Chul , Lee Chang‐Soo , Kim Kyung‐Hyun , Huh Chul , Kim Eui‐Tae 
Published: February 2009

AbstractWe report the light‐emitting diode (LED) characteristics of colloidal core‐shell CdSe/ZnS nanocrystal quantum dots (QDs) embedded in TiO2–δ thin films on Si substrate. High‐quality CdSe/ZnS QDs were synthesized via a pyrolysis in the range of 220–280 °C. The QDs were embedded in TiO2–δ thin film at 200 °C by plasma‐enhanced metallorganic chemical vapor deposition. The diode structure of n‐TiO2–δ /QDs/p‐Si showed electroluminescence characteristics, indicating the possibility of LED applications of colloidal CdSe/ZnS nanocrystal QDs embedded in oxide films on large‐area Si wafer. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto photoluminescence in droplet epitaxial GaAs quantum rings
Authors: Kuroda Takashi , Belhadj Thomas , Mano Takaaki , Urbaszek Bernhard , Amand Thierry , Marie Xavier , Sanguinetti Stefano , Sakoda Kazuaki , Koguchi Nobuyuki 
Published: February 2009

AbstractMaking use of a novel droplet epitaxy technique, we realize GaAs ring‐shaped quantum dots of high circular symmetry. Here, we report on photoluminescence (PL) study of single isolated quantum rings in magnetic field up to 10 T. Polarized PL signals show a significant reduction in their intensity at >6 T. Possible origins accounting for this observation are discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Point defect content and optical transitions in bulk aluminum nitride crystals
Authors: Bickermann Matthias , Epelbaum Boris M. , Filip Octavian , Heimann Paul , Nagata Shunro , Winnacker Albrecht 
Published: February 2009

AbstractDifferent zones of nominally undoped AlN bulk single crystals are investigated using optical absorption and cathodoluminescence. Incorporation of impurities and formation of intrinsic defects during growth strongly depend on the facet which forms the zone. Following first principles calculations and earlier observations on AlN epilayers, we assign the endpoints of the observed optical transitions to ionization levels of oxygen, VAl2–/3–, and (VAl–ON)–/2–. According to the strength of the respective optical transitions in different zones, we find that oxygen contamination increases in the order Al‐polar (0001), rhombohedral {10$ \bar 1 $2} and prismatic {10$ \bar 1 $0}, N‐polar (000$ \bar 1 $). We conclude that the low UV transmittance typically observed in bulk AlN is caused by the formation of VAl and (VAl–ON). These deep levels form in the presence of oxygen, which is the major contaminant in bulk AlN. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Depth profiling of optical and vibrational properties in GaN/AlN quantum dot superlattices
Authors: Cros A. , Fresneda J. , Budagosky J. A. , Amstatt B. , Daudin B. 
Published: February 2009

AbstractSpatially resolved confocal μ‐Raman and μ‐photoluminescence experiments were performed to analyze the vibrational and optical properties of GaN/AlN quantum dots as a function of depth. Two approaches have been followed. First, spectra were taken by defocusing the microscope objective at various depths on the sample surface. In a second set of experiments a bevel at an angle of 20° with respect to the surface normal was prepared by mechanical polishing of the surface, and spectra were taken across the bevel. The E2h vibrational modes ascribed to the GaN QDs and the AlN spacer redshift towards the surface, indicating the progressive relaxation of the QDs and a considerable increase of the tensile strain in the AlN spacer. The photoluminescence is found to blueshift and narrow towards the surface. This behaviour is ascribed to the decrease of the QD internal electric field as a consequence of the relaxation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic properties of microwires with amorphous structure after thermo mechanical treatment
Authors: Larin V. S. , Zhukov A. 
Published: February 2009

AbstractFe74B13Si11C2 microwires with positive magnetostriction constant obtained by the Taylor–Ulitovski method have been subjected to a thermal treatment under stress. Drastic changes of the initially rectangular hysteresis loop into an inclined loop with large anisotropy field in stress annealed samples have been observed and analyzed. Under application of tensile stress the opposite effect has been observed on inclined loop converted into a rectangular loop in several stages. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interacting antiferromagnetic and ferroelectric domain structures of multiferroics
Authors: Gareeva Z. V. , Zvezdin A. K. 
Published: February 2009

AbstractThe correlation between antiferromagnetic and ferroelectric domain structures in multiferroics has been studied. The role of magnetoelectric interactions in the formation of antiferromagnetic domain structure has been analysed. It has been shown that the major physical mechanism binding antiferromagnetic domains to ferroelectric ones is the inhomogeneous flexomagnetoelectric interaction of the Pz [(l ∇)lz – lz(∇l)] type. The dependences illustrating the rearrangement of antiferromagnetic domain patterns together with changes of the ferroelectric domain thickness have been analyzed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Toxicological assessment of beta‐lapachone on organs from pregnant and non‐pregnant rats
Authors: de Almeida Edvaldo Rodrigues , Lucena Flávia Raquel Santos , Silva Camilla Vila Nova Soares , da Silva Costa‐Junior Wilson , Cavalcanti Jouse Bezerra , Couto Gerald Bosco Lindoso , da Silva Luiz Lúcio Soares , da Mota Diógenes Luís , da Silveira Alex Benício , de Sousa Filho Samuel Daniel , da Silva Aldo Cezar Passilongo 
Published: February 2009

AbstractNaphthoquinones have been studied extensively due to their activity as topoisomerase inhibitors. These enzymes are critical to DNA replication in cells. β‐Lapachone (beta‐lap) is an o‐naphthoquinone chemically obtained from lapachol. This work results in a toxicological evaluation of beta‐lap in Wistar rats observing the following parameters: teratology, histology, hematology and serum biochemistry. The data demonstrate teratogenic action at the doses used, as well as hematological alterations in the total leukocytes, monocytes and segmented. The biochemical data demonstrated an increase in gamma glutamyl transferase, alkaline phosphatase and glutamate pyruvate transaminase levels. Histological study showed significant alterations in the spleen, however, the liver and kidney did not present significant alterations. Copyright © 2009 John Wiley & Sons, Ltd.
REAL—Ensemble radar precipitation estimation for hydrology in a mountainous region
Authors: Germann Urs , Berenguer Marc , Sempere‐Torres Daniel , Zappa Massimiliano 
Published: February 2009

AbstractAn elegant solution to characterise the residual errors in radar precipitation estimates is to generate anensembleof precipitation fields. The paper proposes a radar ensemble generator designed for usage in the Alps using LU decomposition (REAL), and presents first results from a real‐time implementation coupling the radar ensemble with a semi‐distributed rainfall–runoff model for flash flood modelling in a steep Alpine catchment. Each member of the radar ensemble is a possible realisation of the unknown true precipitation field given the observed radar field and knowledge of the space–time error structure of radar precipitation estimates. Feeding the alternative realisations into a hydrological model yields a distribution of response values, the spread of which represents the sensitivity of runoff to uncertainties in the input radar precipitation field.The presented ensemble generator is based on singular value decomposition of the error covariance matrix, stochastic simulation using the LU decomposition algorithm, and autoregressive filtering. It allows full representation of spatial dependence of the mean and covariances of radar errors. This is of particular importance in a mountainous region with large uncertainty in radar precipitation estimates and strong dependence of error structure on location. The real‐time implementation of the radar ensemble generator coupled with a semi‐distributed hydrological model in the framework of the forecast demonstration project MAP D‐PHASE is one of the first experiments of this type worldwide, and is a fully novel contribution to this evolving area of applied research. Copyright © 2009 Royal Meteorological Society
Testing for sphericity in phase I control chart applications
Authors: Windfeldt Gitte B. , Bisgaard Søren 
Published: February 2009

AbstractWhen using x̄–R charts it is a crucial assumption that the observations within samples are independent and have common variance. However, this assumption is almost never checked. We propose to use the samples gathered during the phase I study and the test for distributional sphericity, to check this assumption. We supply a graph of the exact percentage points for the distribution of the test statistics. The test statistics can be computed with standard statistical software. Together with the graph of the exact percentage points, the test can easily be performed during a phase I study. We illustrate the method with examples. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of etchant on the nanostructure of dentin: an atomic force microscope study
Authors: Ma Shuyuan , Cai Jiye , Zhan Xinwen , Wu Yangzhe 
Published: February 2009

AbstractThe objective of this study is to investigate effects of etchant on dentin surface as a function of etching time by atomic force microscopy (AFM). Twenty intact, freshly extracted noncarious human teeth were used to make 40 dentin discs and the discs were randomly divided into 4 groups. A commercial etchant was applied on these dentin discs. The main component of the etchant is 32% phosphoric acid and the etching time for the four dentin disc groups was 0, 20, 40, and 60 s. The AFM results show progressive changes of the surface morphology as the etching time increases. Significant difference of average roughness (Ra) exists in the dentin surface among all four groups (p<0.05). The statistic difference of diameters of dentinal tubule orifice (Dt) exists between the control group and all other groups (p<0.05), whereas the Dts for the 40‐s group and 60‐s group are not statistically different (p>0.05). Our results showed that acid treatment has a significant influence on dentin demineralization and the effective etching time of the dentin surface appears to be 60 s. We provide a new nanoscale insight into the dentin surface treatment and this can help us to select the optimal etching time in clinic. SCANNING 31: 28–34, 2009. © 2009 Wiley Periodicals, Inc.
Surface characterization of a cross‐linked cytochrome c film on cysteamine‐modified gold electrodes
Authors: De Wael Karolien , Van Vlierberghe Sandra , Buschop Hans , Dubruel Peter , Vekemans Bart , Schacht Etienne , Vincze Laszlo , Adriaens Annemie 
Published: February 2009

AbstractThe aim of the present paper is to characterize a cross‐linked horse heart cytochrome c (HHC) film on cysteamine‐modified gold electrodes. The HHC film was deposited using 1‐ethyl‐3‐(3‐dimethylaminopropyl)‐carbodiimide (EDC) as a coupling agent. Attenuated total reflection infrared (ATR‐IR) spectroscopic analyses were performed to characterize the newly formed surface on a qualitative and conformational level. The film thickness was measured using a noncontact optical surface profiler, while quantitative data and information on the heterogeneity of the film were obtained by means of synchrotron radiation X‐ray micro fluorescence (SR micro‐XRF). Results indicate that, in addition to electrochemical studies, spectroscopic analysis methods are essential to gain insight in the effect of immobilization strategies on protein conformations. The latter is of relevance in the development and optimization of biosensors. Copyright © 2009 John Wiley & Sons, Ltd.
Adverse Effects of Titanium Dioxide Nanoparticles on Human Dermal Fibroblasts and How to Protect Cells
Authors: Pan Zhi , Lee Wilson , Slutsky Lenny , Clark Richard A. F. , Pernodet Nadine , Rafailovich Miriam H. 
Published: February 2009

AbstractThe effects of exposure of human dermal fibroblasts to rutile and anatase TiO2 nanoparticles are reported. These particles can impair cell function, with the latter being more potent at producing damage. The exposure to nanoparticles decreases cell area, cell proliferation, mobility, and ability to contract collagen. Individual particles are shown to penetrate easily through the cell membrane in the absence of endocytosis, while some endocytosis is observed for larger particle clusters. Once inside, the particles are sequestered in vesicles, which continue to fill up with increasing incubation time till they rupture. Particles coated with a dense grafted polymer brush are also tested, and, using flow cytometry, are shown to prevent adherence to the cell membrane and hence penetration of the cell, which effectively decreases reactive oxygen species (ROS) formation and protects cells, even in the absence of light exposure. Considering the broad applications of these nanoparticles in personal health care products, the functionalized polymer coating can potentially play an important role in protecting cells and tissue from damage.
Carbon‐Nanotube–Polymer Nanocomposites for Field‐Emission Cathodes
Authors: Connolly Thomas , Smith Richard C. , Hernandez Yenny , Gun'ko Yurii , Coleman Jonathan N. , Carey J. David 
Published: February 2009

AbstractThe electron field‐emission (FE) characteristics of functionalized single‐walled carbon‐nanotube (CNT)–polymer composites produced by solution processing are reported. It is shown that excellent electron emission can be obtained by using as little as 0.7% volume fraction of nanotubes in the composite. Furthermore by tailoring the nanotube concentration and type of polymer, improvements in the charge transfer through the composite can be obtained. The synthesis of well‐dispersed randomly oriented nanotube–polymer composites by solution processing allows the development of CNT‐based large area cathodes produced using a scalable technology. The relative insensitivity of the cathode's FE characteristics to the electrical conductivity of the composite is also discussed.
Inkjet‐Printed Multicolor Arrays of Highly Luminescent Nanocrystal‐Based Nanocomposites
Authors: Kim Joo Yeon , Ingrosso Chiara , Fakhfouri Vahid , Striccoli Marinella , Agostiano Angela , Curri M. Lucia , Brugger Jurgen 
Published: February 2009

AbstractInkjet technology is a compelling method for the flexible and cost‐effective printing of functional inks. We show that nanocomposite solutions based on polystyrene and differently sized core/shell‐type nanocrystals (NCs) formed by a CdSe core coated with a shell of ZnS (CdSe@ZnS) in a single solvent, chloroform, can be reliably dispensed into luminescent, multicolor pixel arrays. This study demonstrates the relevance of parameters like polymer concentration and nozzle diameter, highlighting how the optimal conditions to print NCs embedded in 5 wt% polystyrene nanocomposite are given by a 70‐µm‐diameter nozzle. The obtained structures show that the bright size‐dependent emission of the NCs in the nanocomposite is retained in the printed pixels.
Fabrication of Nanowire Channels with Unidirectional Alignment and Controlled Length by a Simple, Gas‐Blowing‐Assisted, Selective‐Transfer‐Printing Technique
Authors: Kim Yong‐Kwan , Kang Pil Soo , Kim Dae‐Il , Shin Gunchul , Kim Gyu Tae , Ha Jeong Sook 
Published: February 2009

AbstractA printing‐based lithographic technique for the patterning of V2O5 nanowire channels with unidirectional orientation and controlled length is introduced. The simple, directional blowing of a patterned polymer stamp with N2 gas, inked with randomly distributed V2O5 nanowires, induces alignment of the nanowires perpendicular to the long axis of the line patterns. Subsequent stamping on the amine‐terminated surface results in the selective transfer of the aligned nanowires with a controlled length corresponding to the width of the relief region of the polymer stamp. By employing such a gas‐blowing‐assisted, selective‐transfer‐printing technique, two kinds of device structures consisting of nanowire channels and two metal electrodes with top contact, whereby the nanowires were aligned either parallel (parallel device) or perpendicular (serial device) to the current flow in the conduction channel, are fabricated. The electrical properties demonstrate a noticeable difference between the two devices, with a large hysteresis in the parallel device but none in the serial device. Systematic analysis of the hysteresis and the electrical stability account for the observed hysteresis in terms of the proton diffusion in the water layer of the V2O5 nanowires, induced by the application of an external bias voltage higher than a certain threshold voltage.
Die neue Eisenbahnbrücke über den Donaukanal und den Winterhafen in Wien
Authors: Dorrer Günther 
Published: February 2009

AbstractMit der Probebelastung der Winterhafenbrücke am 01.09.2008 wurde die seit April 1945 zerstörte Gleisverbindung zwischen Donaulände‐ und Donauuferbahn wieder hergestellt. Mit einer Länge von 168 m bildet die neue eingleisige Eisenbahnbrücke, welche als Zweifelddurchlaufträger konzipiert ist, das zentrale Bindeglied und somit das Herzstück des Projekts. Die beiden Spannweiten wurden als dreieckförmiger Fachwerkträger über den Donaukanal und flache Trogbrücke über den Winterhafen aufgelöst. Die Planung, Herstellung und Montage der Stahlbrücke erfolgten in mehreren Etappen und stellte eine enorme bautechnische Herausforderung dar. Mit der Gesamtfertigstellung des Projektes im September 2009 wird ein wesentlicher Beitrag zur Verlagerung des Güterverkehrs von der Straße auf die umweltfreundliche Schiene geleistet (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
VFT‐WIB‐Brücke bei Vigaun – Verbundbrücke mit externer Bewehrung
Authors: Seidl Günter , Braun Anton 
Published: February 2009

AbstractDer Verbunddübel ermöglicht neue Konstruktionsprinzipien im Brückenbau. Mit der Straßenbrücke in Vigaun/Österreich ist im Herbst 2008 die erste Brücke in VFT‐WIB‐Bauweise in Betrieb gegangen. Zwei Verbundfertigteile mit halbierten Walzträgern als Untergurt bilden den Querschnitt. Die durch den Schneideprozess mit Verbunddübeln versehenen halbierten Walzträger wirken als “externe” Bewehrung im Querschnitt und vereinen Schlankheit und Wirtschaftlichkeit im Verbundbrückenbau. Der Aufsatz beschreibt das 78m lange 3‐Feld‐Rahmenbauwerk über die Bahnstrecke von Salzburg nach Wörgl unter den Gesichtspunkten Entwurf, versuchsgestützte Bemessung und Ausführung (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rheinbrücke Breisach – Umbau und Instandsetzung einer 45 Jahre alten Stahlkonstruktion
Authors: Lenz Peter , Emrich Christine , Wenzel Gernot , Materna Stefan , Loose Tobias 
Published: February 2009

AbstractDie Rheinbrücke Breisach zwischen Breisach in Baden‐Württemberg und Neuf‐Brisach im Elsass ist nach der Europabrücke Kehl–Straßburg die wichtigste regionale Straßenverbindung zwischen Deutschland und Frankreich. Die vierfeldige Straßenbrücke wurde 1962 auf den Fundamenten einer ehemaligen Eisenbahnbrücke errichtet. Der mit Flachblech‐ und Winkelsteifen ausgesteifte Hohlkastenquerschnitt der Brücke wurde sowohl geschweißt als auch genietet und geschraubt. Die Konstruktion des Schrammbordes mit einer damals des Öfteren verwendeten, aus heutiger Sicht ungünstigen Anschlussart sowie Schäden an der im Hohlkasten verlaufenden Entwässerung führten zu massiven Korrosionsschäden. Zukünftig soll ein Radweg über das Bauwerk verlaufen. Dies erfordert eine Verbreiterung des südlichen Gehweges. Die Umbau‐ und Instandsetzungsmaßnahme wurde im Frühjahr 2008 begonnen.In diesem Aufsatz soll nicht nur auf die einzelnen Details der Baumaßnahme eingegangen werden, sondern vielmehr auf die im Bauwerk versteckten Schwierigkeiten, die erst während der Durchführung der Baumaßnahme zu erkennen waren und gelöst werden mussten. Eine weitere Besonderheit des Bauwerks liegt darin, dass zwei Straßenbauverwaltungen, Frankreich und Deutschland, für den Unterhalt der Brücke zuständig sind (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Blockade of Peroxynitrite-Induced Neural Stem Cell Death in the Acutely Injured Spinal Cord by Drug-Releasing Polymer
Authors: Yu Dou , Neeley William L. , Pritchard Christopher D. , Slotkin Jonathan R. , Woodard Eric J. , Langer Robert , Teng Yang D. 
Published: February 2009

Abstract
Therapeutic impact of neural stem cells (NSCs) for acute spinal cord injury (SCI) has been limited by the rapid loss of donor cells. Neuroinflammation is likely the cause. As there are close temporal-spatial correlations between the inducible nitric oxide (NO) synthase expression and the donor NSC death after neurotrauma, we reasoned that NO-associated radical species might be the inflammatory effectors which eliminate NSC grafts and kill host neurons. To test this hypothesis, human NSCs (hNSCs: 5 × 104 to 2 × 106 per milliliter) were treated in vitro with “plain” medium, 20 μM glutamate, or donors of NO and peroxynitrite (ONOO−; 100 and 400 μM of spermine or DETA NONOate, and SIN-1, respectively). hNSC apoptosis primarily resulted from SIN-1 treatment, showing ONOO−-triggered protein nitration and the activation of p38 MAPK, cytochrome c release, and caspases. Therefore, cell death following post-SCI (p.i.) NO surge may be mediated through conversion of NO into ONOO−. We subsequently examined such causal relationship in a rat model of dual penetrating SCI using a retrievable design of poly-lactic-co-glycolic acid (PLGA) scaffold seeded with hNSCs that was shielded by drug-releasing polymer. Besides confirming the ONOO−-induced cell death signaling, we demonstrated that cotransplantation of PLGA film embedded with ONOO− scavenger, manganese (III) tetrakis (4-benzoic acid) porphyrin, or uric acid (1 μmol per film), markedly protected hNSCs 24 hours p.i. (total: n = 10). Our findings may provide a bioengineering approach for investigating mechanisms underlying the host microenvironment and donor NSC interaction and help formulate strategies for enhancing graft and host cell survival after SCI.
Disclosure of potential conflicts of interest is found at the end of this article.