bluuebunny/crossref_metadata_2025 huggingface dataset:
Implication of the chemokine CCL2 in trigeminal nociception and traumatic neuropathic orofacial pain
Authors: Dauvergne C. , Molet J. , Reaux‐Le Goazigo A. , Mauborgne A. , Mélik‐Parsadaniantz S. , Boucher Y. , Pohl M.
Published: August 2013

Background

Chemokine (C‐C motif) ligand 2 (CCL2) participates in different mechanisms contributing to the spinal cord inflammation and pain development after sciatic nerve injury. Recent data also support its role in orofacial thermal hypersensitivity, although its implication in different phases of trigeminal pain emergence is unclear. We assessed the importance of CCL2 signalling in biochemical and behavioural alterations during the early and late stages following chronic constriction injury of infraorbital nerve (ION‐CCI), a model of peripheral traumatic trigeminal pain.

Methods

After evaluating the consequences of CCL2 intracisternal injection in naïve rats, we determined the expression changes for CCL2, inflammatory and glia activation markers in the somatosensory trigeminal complex (STC) and trigeminal ganglia (TG) after ION‐CCI. The role of CCL2 signalling was assessed using pre‐emptive or ‘curative’ intracisternal treatment with specific CCL2 receptor antagonist – INCB3344.

Results

Exogenous CCL2 evoked spontaneous behaviour reminiscent of orofacial pain and marked mechanical hypersensitivity, associated with increased expression of proinflammatory cytokines and glial markers in STC and TG. CCL2‐evoked changes were prevented by the co‐administration of INCB3344. Two weeks after ION‐CCI, mRNA for CCL2, glial and inflammatory markers were up‐regulated, and CCL2‐immunoreactivity accumulated in central and ganglionic tissues. At this time, repeated intracisternal administration of INCB3344 did not attenuate the ION‐CCI‐associated behavioural nor biochemical changes. By contrast, pre‐emptive INCB3344 treatment delayed the emergence of trigeminal mechanical allodynia and associated biochemical alterations.

Conclusions

Our data suggest that CCL2 is involved principally in the early events accompanying the ION lesion rather than in long‐term alterations and the maintenance of trigeminal mechanical hypersensitivity.
Contributions of pauli repulsions to the energetics and physical properties computed in QM/MM methods
Authors: Jin Yingdi , Johnson Erin R. , Hu Xiangqian , Yang Weitao , Hu Hao
Published: August 2013

Conventional combined quantum mechanical/molecular mechanical (QM/MM) methods lack explicit treatment of Pauli repulsions between the quantum‐mechanical and molecular‐mechanical subsystems. Instead, classical Lennard‐Jones (LJ) potentials between QM and MM nuclei are used to model electronic Pauli repulsion and long‐range London dispersion, despite the fact that the latter two are inherently of quantum nature. Use of the simple LJ potential in QM/MM methods can reproduce minimal geometries and energies of many molecular clusters reasonably well, as compared to full QM calculations. However, we show here that the LJ potential cannot correctly describe subtle details of the electron density of the QM subsystem because of the neglect of Pauli repulsions between the QM and MM subsystems. The inaccurate electron density subsequently affects the calculation of electronic and magnetic properties of the QM subsystem. To explicitly consider Pauli interactions with QM/MM methods, we propose a method to use empirical effective potentials on the MM atoms. The test case of the binding energy and magnetic properties of a water dimer shows promising results for the general application of effective potentials to mimic Pauli repulsions in QM/MM calculations. © 2013 Wiley Periodicals, Inc.
Immunoelectron microscopic observation of connexin43 in rat odontoblasts
Authors: Muramatsu Takashi , Hashimoto Sadamitsu , Shibukawa Yoshiyuki , Yuasa Kazuhiro , Furusawa Masahiro , Shimono Masaki
Published: August 2013

Gap junctions play an important role in differentiation of odontoblasts. Gap junction protein, connexin 43 is expressed in odontoblast. However, the detailed localization in odontoblasts has yet to be fully investigated. We investigated the localization of connexin43 in rat odontoblasts immuno‐electron microscopically. The rats were transcardially fixed with 1% paraformaldehyde in 0.1M phosphate buffer, and mandibles were decalcified with 10% ethylenediamine tetraacetic acid. Pre‐embedding method was carried out for immuno‐electron microscopic analysis. Microscopically, gap junctions were localized between bodies of odontoblasts, and between bodies and processes of odontoblasts. The gap junctions were labeled with gold particles that indicated connexin43. These results suggest that gap junctions between odontoblasts are definitely composed of connexin43 in rats, and our methods used in this study is useful to investigate localization of connexin43 immuno‐electron microscopically. Microsc. Res. Tech., 76:988–991, 2013. © 2013 Wiley Periodicals, Inc.
Nanoscale elemental sensitivity study of Nd2Fe14B using absorption correlation tomography
Authors: Kao Thomas L. , Shi Crystal Y. , Wang Junyue , Mao Wendy L. , Liu Yijin , Yang Wenge
Published: August 2013

Transmission X‐ray microscopy (TXM) is a rapidly developing technique with the capability of nanoscale three dimensional (3D) real‐space imaging. Combined with the wide range in energy tunability from synchrotron sources, TXM enables the retrieval of 3D microstructural information with elemental/chemical sensitivity that would otherwise be inaccessible. The differential absorption contrast above and below absorption edges has been used to reconstruct the distributions of different elements, assuming the absorption edges of the interested elements are fairly well separated. Here we present an “Absorption Correlation Tomography” (ACT) method based on the correlation of the material absorption across multiple edges. ACT overcomes the significant limitation caused by overlapping absorption edges, significantly expands the capabilities of TXM, and makes it possible for fully quantitative nano‐scale 3D structural investigation with chemical/elemental sensitivity. The capability and robustness of this new methodology is demonstrated in a case study of an important type of rare earth magnet (Nd2Fe14B). Microsc. Res. Tech. 76:1112–1117, 2013. © 2013 Wiley Periodicals, Inc.
Burst‐swimming performance predicts the outcome of cannibalistic interactions in green poison frog larvae (Dendrobates auratus)
Authors: Wilcox Sean C. , Lappin A. Kristopher
Published: August 2013

Whole‐animal performance (e.g., swimming speed, bite force) functions as a fundamental link between organism and environment and, as such, performance characteristics are important in determining the outcomes of agonistic interactions, both interspecific and intraspecific. Cannibalism is an intraspecific agonistic interaction for which winners may be expected to exhibit superior performance in characteristics relevant to cannibalistic behavior. The larvae of the Green Poison Frog (Dendrobates auratus) exhibit cannibalistic behavior in which “fast‐starts” (i.e., high velocity and acceleration from a resting position) are used in attempts to bite and avoid being bitten by conspecifics. We tested the hypothesis that superior fast‐start swimming performance is positively associated with winning cannibalistic interactions between similarly sized individuals. Fast‐starts by larvae were imaged with a high‐speed camera, and pairs of size‐matched individuals then underwent interaction trials to determine whether swimming performance is associated with winning a cannibalistic interaction. Linear acceleration of the snout tip, approximating the position of the mouthparts used to attack an opponent, was significantly greater in winners than losers. At the estimated center of mass, generally representing a target for an attacking opponent, linear velocity and acceleration were significantly greater in winners than losers. Understanding the role of performance in intraspecific interactions can help elucidate how they contribute to population dynamics, and thus how such interactions ultimately drive morphological and behavioral evolution. J. Exp. Zool. 319A: 495–504, 2013. © 2013 Wiley Periodicals, Inc.
Effects of Copolymer Structure on the Mechanical Properties of Poly(dimethyl siloxane) Poly(oxamide) Segmented Copolymers
Authors: Buckwalter Daniel J. , Inglefield David L. , Enokida Joshua S. , Hudson Amanda G. , Moore Robert B. , Long Timothy E.
Published: August 2013

An investigation of the structure–property relationships of poly(dimethyl siloxane) (PDMS) polyoxamide segmented copolymers reveals the impact of oxamide spacing and PDMS molecular weight on physical properties. Varying the length of the methylene spacing between the oxamide hydrogen bonding groups in the hard segment (HS), as well as the PDMS soft segment molecular weight, provides insight into the influence on thermal and mechanical properties. Bulk polycondensation of ethyl‐oxalate‐terminated PMDS oligomers with diamines yields optically clear, thermoplastic elastomers with excellent mechanical properties. The structure–property investigation reveals optimum mechanical properties of PDMS polyoxamide segmented copolymers occur with the smallest spacing between oxamide groups in the HS.

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A mutation in the promoter region of zipA, a component of the divisome, suppresses the shape defect of RodZ‐deficient cells
Authors: Shiomi Daisuke , Niki Hironori
Published: August 2013

RodZ is important for maintaining the rod shape of Escherichia coli. Loss of RodZ causes conversion of the rod shape to a round shape and a growth rate slower than that of wild‐type cells. Suppressor mutations that simultaneously restore both the growth rates and the rod shape were isolated. Most of the suppressor mutations are found in mreB, mrdA, or mrdB. One of the mutations was in the promoter region of zipA, which encodes a crucial component of the cell division machinery. In this study, we investigated the mechanism of the suppression by this mutation. ZipA was slightly but significantly increased in the suppressor cells and led to a delay in cell division. While round‐shaped mreB and mrdA mutants lose cell bipolarity, we found that round‐shaped rodZ mutants retained cell bipolarity. Therefore, we concluded that a delay in the completion of septation provides extra time to elongate the cell laterally so that the zipA suppressor mutant is able to recover its ovoid or rod shape. The suppression by zipA demonstrates that the regulation of timing of septation potentially contributes to the conversion of morphology in bacterial cells.
Tripaddled anterolateral thigh flap for simultaneous reconstruction of bilateral buccal defects after buccal cancer ablation and severe oral submucous fibrosis release: A case report
Authors: Jiang Canhua , Guo Feng , Li Ning , Huang Pengxin , Jian Xinchun , Munnee Krishna
Published: August 2013

For buccal squamous cell carcinoma (SCC) patients accompanied with severe oral submucous fibrosis (OSF), it is a challenge to simultaneously reconstruct bilateral buccal defects created from cancer resection and contralateral OSF release to improve postoperative mouth opening. Herein, we present a case of reconstruction of bilateral buccal defects in a 46‐year‐old patient who had left buccal SCC accompanied with severe OSF. Extensive ablation involved the left full‐thickness cheek as well as part of mandible and a release of right OSF tissue were performed. A tripaddled anterolateral thigh (ALT) flap with three independent sets of perforators was harvested for reconstruction. The flap survived in its entirety. No donor or recipient site complication occurred. The preoperative inter‐incisor distance (IID) was 1 mm, while the postoperative IID was 23 mm. This is the first report on the use of one tripaddled ALT flap for reconstruction of bilateral buccal defects created from cancer ablation and severe contralateral OSF release. © 2013 Wiley Periodicals, Inc. Microsurgery 33:667–671, 2013.
Halogen effect on structure and 13C NMR chemical shift of 3,6‐disubstituted‐N‐alkyl carbazoles
Authors: Radula‐Janik Klaudia , Kupka Teobald , Ejsmont Krzysztof , Daszkiewicz Zdzislaw , Sauer Stephan P. A.
Published: August 2013

Structures of selected 3,6‐dihalogeno‐N‐alkyl carbazole derivatives were calculated at the B3LYP/6‐311++G(3df,2pd) level of theory, and their 13C nuclear magnetic resonance (NMR) isotropic shieldings were predicted using density functional theory (DFT). The model compounds contained 9H, N‐methyl and N‐ethyl derivatives. The relativistic effect of Br and I atoms on nuclear shieldings was modeled using the spin–orbit zeroth‐order regular approximation (ZORA) method. Significant heavy atom shielding effects for the carbon atom directly bonded with Br and I were observed (~−10 and ~−30 ppm while the other carbon shifts were practically unaffected). The decreasing electronegativity of the halogen substituent (F, Cl, Br, and I) was reflected in both nonrelativistic and relativistic NMR results as decreased values of chemical shifts of carbon atoms attached to halogen (C3 and C6) leading to a strong sensitivity to halogen atom type at 3 and 6 positions of the carbazole ring. The predicted NMR data correctly reproduce the available experimental data for unsubstituted N‐alkylcarbazoles. Copyright © 2013 John Wiley & Sons, Ltd.
Optimal therapy protocols in the mathematical model of acute leukemia with several phase constraints
Authors: Todorov Y. , Nuernberg F.
Published: August 2013

A mathematical model for leukemia therapy based on the Gompertzian law of cell growth is investigated. The effect of the therapy is described in terms of therapy functions. Two types of therapy functions are considered: monotone and non‐monotone. In the first case, the effect of the chemotherapy on the normal cells directly depends on the quantity of the chemotherapeutic agent. In the second case, we consider a therapy function with a threshold effect, which influences the leukemia cells. This effect can describe resistance to the therapy. The optimal control problem has the purpose of minimizing the number of the leukemia cells subject to the constraints of the normal cells, whose number must not fall below a prescribed critical limit and of the amount of the chemotherapeutic agents in the body of the patient (i.e. constraint on the toxicity). Furthermore, a third phase constraint on the cumulative amount of the medicine over the whole therapy process is considered, which can be interpreted as an economic factor of the therapy. This optimization problem is solved analytically with the help of the Pontryagin's Maximum Principle, extension of penalty functions and additional analysis. Copyright © 2013 John Wiley & Sons, Ltd.
Phytochemical Study of the Alkaloidal Fractions of Unonopsis duckei R. E. Fr. Guided by Electrospray Ionisation Ion‐trap Tandem Mass Spectrometry
Authors: da Silva Felipe M. A. , de Souza Afonso D. L. , Koolen Hector H. F. , Barison Andersson , Vendramin Mayara E. , Costa Emmanoel V. , Ferreira Antonio G. , Pinheiro Maria Lúcia B.
Published: August 2013

Introduction

The Unonopsis genus is a promising source of aporphinoid alkaloids, substances with great biological potential. These alkaloids have a well‐defined mass spectrometry fragmentation pattern that, together with previous phytochemical knowledge, can guide the isolation of alkaloids not yet described for the genus.

Objective

Isolate substances not yet described in the Unonopsis genus, guided by alkaloidal profile analyses of stem barks, twigs and leaves of Unonopsis duckei using electrospray ionisation ion‐trap tandem mass spectrometry (ESI‐IT/MSn).

Methods

Methanolic extracts from stem barks, twigs and leaves were submitted to a liquid–liquid, acid–base partitioning treatment to obtain the alkaloidal fractions. These fractions were analysed by direct infusion into an ESI‐IT/MSn system. The major alkaloids observed for each fraction were submitted to fragmentation analysis.

Results

The MS fragmentation patterns revealed the presence of alkaloids previously reported for Annonaceae, including nornuciferine, anonaine, asimilobine, liriodenine and lysicamine, known for the Unonopsis genus, as well as others that were not yet described for this genus. In this way, the proaporphine alkaloid glaziovine was isolated, as well as a mixture of the aporphine alkaloids glaucine and norglaucine, all described for the first time in the Unonopsis genus.

Conclusion

Mass spectrometry monitoring was fundamental to prioritise the isolation of substances not yet identified for the Unonopsis genus, dismissing known compounds and simplifying the phytochemical study. Copyright © 2013 John Wiley & Sons, Ltd.
Stereoelectronic effects in Menshutkin‐type SN2 reactions: theoretical study based on through‐space/bond orbital interaction analysis
Authors: Jiang Lizhi , Orimoto Yuuichi , Aoki Yuriko
Published: August 2013

Through‐space/bond orbital interaction analysis has been applied to investigate the stereoelectronic effects on stabilizing the transition state of Menshutkin‐type SN2 reactions. The mechanism of how the substituent effects work on accelerating the reactions has been demonstrated from orbital interaction perspective. The geometrical structures and Mulliken charge distributions have been compared to elucidate the substituent effects for the SN2 reaction center. It is found that the substituents lower the activation energies by strengthening the orbital interactions in the SN2 reaction process. When electron‐donating and electron‐accepting substituents (–C6H5 and –CHO) are introduced to the same central carbon at the reaction center, the symmetry allows the π–π* interactions among the donor and acceptor in the transition state. It stabilizes the transition state much more than the reactant complex. And the π–π* interactions are estimated to decrease about 2.28 kcal/mol of the energy for transition state. The σ‐like orbitals of the partial bond around the central carbon are reactive, and the σ–π* orbital interactions stabilize the reactant complex much more than the π–σ* interaction. When the σ–π* and π–σ* interactions are deleted from the system, the activation energy increases and turns close to the values of the systems which are without such substituents. It can be concluded that the π–π*, σ–π*, and π–σ* interactions cooperatively accelerates the SN2 reaction by stabilizing its transition state. Copyright © 2013 John Wiley & Sons, Ltd.
Charged surfactants induce a non‐fibrillar aggregation pathway of amyloid‐beta peptide
Authors: Loureiro Joana A. , Rocha Sandra , Pereira Maria do Carmo
Published: August 2013

The amyloid β‐peptide with a sequence of 42 amino acids is the major constituent of extracellular amyloid deposits in Alzheimer's disease plaques. The control of the peptide self‐assembly is difficult to achieve because the process is fast and is affected by many variables. In this paper, we describe the effect of different charged and non‐charged surfactants on Aβ(1‐42) fibrillation to define common alternate aggregation pathways. The characterization of the peptide‐surfactant interactions by ultra‐structural analysis, thioflavin T assay and secondary structure analysis, suggested that charged surfactants interact with Aβ(1‐42) through electrostatic interactions. Charged micelles slow down the aggregation process and stabilize the peptide in the oligomeric state, whereas non‐charged surfactants promote the Aβ(1‐42) fibril formation. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Initial growth stages of heavily boron‐doped HFCVD diamond for electrical probe application
Authors: Simon D. K. , Tsigkourakos M. , Hantschel T. , Conard T. , Vandervorst W.
Published: August 2013

The initial growth stages of boron‐doped diamond, deposited by hot‐filament chemical vapour deposition (HFCVD), are crucial for the conductivity of moulded tips used in scanning spreading resistance microscopy (SSRM) where the first grown layer is the active layer of the tip. In this paper, we investigate therefore the beginning of the growth by interrupting the HFCVD process for nano‐crystalline (NCD) and microcrystalline diamond (MCD) films at various moments during the filament carburisation. The characterisation of these initial stages is done by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). A slow growth start after the first ∼20 min of carburisation is revealed by the change of C‐bindings at the seed surface towards pure CC indicated by XPS. AFM measurements show that the actual growth starts after ∼40 min. Our work shows that boron tends to form BO clusters at the beginning of the growth (∼50 min) which can affect the conductivity of the first layers of our tips. By using carburised filaments the diamond seeds form earlier more pronounced crystal shapes which are related to a higher sp3/sp2 ratio. This is advantageous for moulded diamond tips used in electrical probing.
Effect of Pt decoration on the gas response of ZnO nanoparticles
Authors: Daryakenari Ahmad Ahmadi , Apostoluk Aleksandra , Delaunay Jean‐Jacques
Published: August 2013

In order to improve the performance of gas sensors based on ZnO nanoparticles, platinum was deposited on the nanoparticle surface using sputtering. Gas‐sensing experiments on Pt‐functionalized ZnO nanoparticles exhibited larger response to ethanol gas at lower operating temperature, attributed to the sensitization and spillover effects. The faster recovery time of Pt‐decorated ZnO nanoparticles is associated with the catalyst effect of Pt. The maximum sensitivity of Pt‐decorated ZnO nanoparticles was more than twice compared to that of bare ZnO nanoparticles. At 400 °C, the response time of Pt‐decorated ZnO nanoparticles to 15 ppm ethanol vapor was 150 s, while that of bare ZnO nanoparticles was of about 1200 s. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light emission from planar‐type ZnO p‐n junction fabricated by PLD
Authors: Kusumori Takeshi , Nakao Setsuo , Yoshimura Kazuki
Published: August 2013

Zinc oxide (ZnO) is a promising wide band‐gap semiconductor for optoelectronic devices such as high‐brightness (HB) light‐emitting‐diode (LEDs) in illumination applications. A significant difficulty has been the preparation of p‐type ZnO, which is indispensable for ZnO LEDs. We have prepared reproducible p‐type zinc oxide films by pulsed‐laser deposition (PLD) and a subsequent thermal annealing treatment. The Hall effect, with a Hall bar configuration, was measured in order to determine the conduction type of the films. The gradient of applied magnetic field vs. Hall voltage clearly implies the successful realization of p‐type ZnO films. After the confirmation of p‐type conductivity, the films were patterned again to prepare the planar‐type p‐n junction. Emission of visible light with bluish white color was observed when electrical current was injected through the junction. The spectra of the light indicate the emission start neat the band edge of ZnO. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO nanorod growth from aqueous solution via microwave heating on paper substrates
Authors: Ogata K. , Koike K. , Sasa S. , Inoue M. , Yano M.
Published: August 2013

ZnO nanorods were grown on paper substrates using aqueous solution at 95 °C by microwave heating. Although no direct growth on paper substrates was observed, surface coating with ZnMgO and Au layers enabled ZnO nanorod growth on paper substrates with rough surface structures of cellulose. X‐ray diffraction (XRD) measurements showed a weak diffraction peak from c‐axis oriented ZnO nanorods associated with tilted ones, which is related with not only rough surface structure of cellulose but also the poor properties of coated layers. In cathodoluminescence (CL) spectra, stronger bandedge emission was observed in ZnO nanorods on ZnMgO/paper in comparison of that on Au/paper substrates. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sol‐gel undoped and Al‐doped ZnO films crystallized under an electric field and the ZnO/Si heterojunction characteristics
Authors: Abe Kazunori , Komiyama Takao , Chonan Yasunori , Yamaguchi Hiroyuki , Aoyama Takashi
Published: August 2013

Effect of electric field on the crystallization of ZnO sol‐gel films was investigated by measuring x‐ray diffraction (XRD) patterns, photoluminescence (PL) spectra, and current‐voltage (I‐V) characteristics of n‐ZnO/p‐Si heterojunctions. When sol‐gel ZnO films (undoped and Al‐doped) were crystallized at 800 °C in air for 10 min, an electric field was applied between 0 and 2.0 kV/cm. As the electric field was increased, the XRD (002) peak intensity increased and had a maximum value at 1.5 and 2.0 kV/cm for the films on quartz and silicon substrates, respectively. The Hall carrier mobility increased and the carrier concentration decreased for the crystallized undoped and Al‐doped films when the electric field was 1.0 kV/cm and 1.5 kV/cm, respectively. As the electric field was increased from 0 to 2.0 kV/cm, the forward current increased and the reverse current decreased for n‐ZnO/p‐Si heterojunctions. These results indicated that application of electric fields was an effective means to reduce the defect density of ZnO sol‐gel films and to improve their heterojunction characteristics.
Characteristics of ZnO/CuO heterojunctions formed by direct bonding and PLD with bias voltage application
Authors: Komatsu Kazuya , Seno Yuki , Komiyama Takao , Chonan Yasunori , Yamaguchi Hiroyuki , Aoyama Takashi
Published: August 2013

Current‐voltage (I–V) characteristics of the n‐ZnO/p‐CuO heterojunctions have been investigated by changing the composition of the ZnO films and by using the direct bonding technique to form the heterojunctions. A ZnO film was deposited on an n‐type ZnO ceramic substrate by the PLD technique with bias voltage application. The change of the PLD bias voltage caused the deviation from the stoichiometric condition for ZnO films and led to growth of different grain sizes. The n‐ZnO/ZnO specimens were directly bonded on p‐type CuO substrates at room temperature. Post annealing at 400 °C for 1 h improved the diode characteristic but more than about 3 h annealing deteriorated the I‐V characteristics. A deposition condition close to stoichiometric oxygen/zinc = 1 caused the largest activation energies for both the forward and the reverse currents while a slightly zinc‐rich condition caused a larger forward and a smaller reverse currents. This suggested the applicability of the direct bonding technique for fabricating excellent ZnO heterojunctions. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First principles studies of structural, electrical and magnetic properties of semiconductor nanowires
Authors: Galicka Marta , Buczko Ryszard , Kacman Perla , Lima Erika N. , Schmidt Tome M. , Shtrikman Hadas
Published: August 2013

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This article reviews recent advances in theoretical description of the properties of various III–V and IV–VI nanowires, which have been obtained using simple ab initio methods. The impact of crystal structure, lateral surfaces, passivation of the dangling bonds and quantum confinement on the stability of the nanowires is discussed. The second part of the paper is devoted to the analysis of III–V and IV–VI nanowires doped with various, in particular magnetic, ions. The influence of the crystal structure of the wire on the segregation and formation energies of different dopants and thus on the electric and magnetic properties of the nanowires is shown. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atomic hydrogen cleaning of In0.53Ga0.47As studied using synchrotron radiation photoelectron spectroscopy
Authors: Brennan Barry , Kumarappan Kumar , Hughes Greg
Published: August 2013

The removal of the native oxides from the In0.53Ga0.47As surface by exposure to atomic hydrogen has been investigated by highly surface sensitive synchrotron radiation based photoelectron spectroscopy. This shows that it is possible to fully remove the arsenic oxides at low temperatures, while still leaving a low concentration of stable Ga2O and In2O at the surface, and no evidence of indium loss from the substrate. The removal of surface carbon contamination is also seen, however full removal is only detected in the absence of prior substrate annealing. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prevention of Urinary Tract Infections with Vaccinium Products
Authors: Davidson Elyad , Zimmermann Benno F. , Jungfer Elvira , Chrubasik‐Hausmann Sigrun
Published: August 2013

Cranberries exert a dose‐dependent inhibition of the adherence of E. coli fimbriae to uroepithelial cells. This was demonstrated in vitro but also ex vivo in vitro with urine from cranberry consumers. The active principle has not been identified in detail but type‐A proanthocyanidins (PAC) play an important role in the mechanism of action. Since the three species, American cranberry (Vaccinium macrocarpon), European cranberry (Vaccinium oxycoccus) and/or lingonberry (Vaccinium vitis‐idaea), have different patterns of type‐A PACs, results from one species cannot be transferred to the others. It seems likely that most of the studies with monopreparations from V. macrocarpon were underdosed. Whereas photometric PAC quantification may overestimate the true content on co‐active compounds, reversed phase high‐performance liquid chromatograpy may underestimate them. Recent studies with PAC doses in the upper range (DMAC method) or declared type‐A PAC content in the daily dose reveal a dose‐dependent trend of clinical effectiveness, however, with a possible ceiling effect. In order to clarify this, future three‐arm studies should investigate Vaccinium preparations with higher type‐A PAC doses than previously used. We analysed two popular European vitis‐idaea products, a mother juice and a proprietary extract. Both preparations may be appropriate to confirm the Vaccinium urinary tract infection‐preventive effect beyond doubt. Copyright © 2013 John Wiley & Sons, Ltd.
Monocular Vision for Long‐term Micro Aerial Vehicle State Estimation: A Compendium
Authors: Weiss Stephan , Achtelik Markus W. , Lynen Simon , Achtelik Michael C. , Kneip Laurent , Chli Margarita , Siegwart Roland
Published: August 2013

The recent technological advances in Micro Aerial Vehicles (MAVs) have triggered great interest in the robotics community, as their deployability in missions of surveillance and reconnaissance has now become a realistic prospect. The state of the art, however, still lacks solutions that can work for a long duration in large, unknown, and GPS‐denied environments. Here, we present our visual pipeline and MAV state‐estimation framework, which uses feeds from a monocular camera and an Inertial Measurement Unit (IMU) to achieve real‐time and onboard autonomous flight in general and realistic scenarios. The challenge lies in dealing with the power and weight restrictions onboard a MAV while providing the robustness necessary in real and long‐term missions. This article provides a concise summary of our work on achieving the first onboard vision‐based power‐on‐and‐go system for autonomous MAV flights. We discuss our insights on the lessons learned throughout the different stages of this research, from the conception of the idea to the thorough theoretical analysis of the proposed framework and, finally, the real‐world implementation and deployment. Looking into the onboard estimation of monocular visual odometry, the sensor fusion strategy, the state estimation and self‐calibration of the system, and finally some implementation issues, the reader is guided through the different modules comprising our framework. The validity and power of this framework are illustrated via a comprehensive set of experiments in a large outdoor mission, demonstrating successful operation over flights of more than 360 m trajectory and 70 m altitude change.
Testing gene‐environment interactions in family‐based association studies using trait‐based ascertained samples
Authors: Zhang Weiming , Langefeld Carl D. , Grunwald Gary K. , Fingerlin Tasha E.
Published: August 2013

The study of gene‐environment interactions is an increasingly important aspect of genetic epidemiological investigation. Historically, it has been difficult to study gene‐environment interactions using a family‐based design for quantitative traits or when parent‐offspring trios were incomplete. The QBAT‐I provides researchers a tool to estimate and test for a gene‐environment interaction in families of arbitrary structure that are sampled without regard to the phenotype of interest, but is vulnerable to inflated type I error if families are ascertained on the basis of the phenotype. In this study, we verified the potential for type I error of the QBAT‐I when applied to samples ascertained on a trait of interest. The magnitude of the inflation increases as the main genetic effect increases and as the ascertainment becomes more extreme. We propose an ascertainment‐corrected score test that allows the use of the QBAT‐I to test for gene‐environment interactions in ascertained samples. Our results indicate that the score test and an ad hoc method we propose can often restore the nominal type I error rate, and in cases where complete restoration is not possible, dramatically reduce the inflation of the type I error rate in ascertained samples. Copyright © 2013 John Wiley & Sons, Ltd.
Multiple imputation for an incomplete covariate that is a ratio
Authors: Morris Tim P. , White Ian R. , Royston Patrick , Seaman Shaun R. , Wood Angela M.
Published: August 2013

We are concerned with multiple imputation of the ratio of two variables, which is to be used as a covariate in a regression analysis. If the numerator and denominator are not missing simultaneously, it seems sensible to make use of the observed variable in the imputation model. One such strategy is to impute missing values for the numerator and denominator, or the log‐transformed numerator and denominator, and then calculate the ratio of interest; we call this ‘passive’ imputation. Alternatively, missing ratio values might be imputed directly, with or without the numerator and/or the denominator in the imputation model; we call this ‘active’ imputation. In two motivating datasets, one involving body mass index as a covariate and the other involving the ratio of total to high‐density lipoprotein cholesterol, we assess the sensitivity of results to the choice of imputation model and, as an alternative, explore fully Bayesian joint models for the outcome and incomplete ratio. Fully Bayesian approaches using Winbugs were unusable in both datasets because of computational problems. In our first dataset, multiple imputation results are similar regardless of the imputation model; in the second, results are sensitive to the choice of imputation model. Sensitivity depends strongly on the coefficient of variation of the ratio's denominator. A simulation study demonstrates that passive imputation without transformation is risky because it can lead to downward bias when the coefficient of variation of the ratio's denominator is larger than about 0.1. Active imputation or passive imputation after log‐transformation is preferable. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.
Atomic‐Layer‐Deposition‐Assisted Formation of Carbon Nanoflakes on Metal Oxides and Energy Storage Application
Authors: Guan Cao , Zeng Zhiyuan , Li Xianglin , Cao Xiehong , Fan Yu , Xia Xinhui , Pan Guoxiang , Zhang Hua , Fan Hong Jin
Published: August 2013

Nanostructured carbon is widely used in energy storage devices (e.g., Li‐ion and Li‐air batteries and supercapacitors). A new method is developed for the generation of carbon nanoflakes on various metal oxide nanostructures by combining atomic layer deposition (ALD) and glucose carbonization. Various metal oxide@nanoflake carbon (MO@f‐C) core‐branch nanostructures are obtained. For the mechanism, it is proposed that the ALD Al2O3 and glucose form a composite layer. Upon thermal annealing, the composite layer becomes fragmented and moves outward, accompanied by carbon deposition on the alumina skeleton. When tested as electrochemical supercapacitor electrode, the hierarchical MO@f‐C nanostructures exhibit better properties compared with the pristine metal oxides or the carbon coating without ALD. The enhancement can be ascribed to increased specific surface areas and electric conductivity due to the carbon flake coating. This peculiar carbon coating method with the unique hierarchical nanostructure may provide a new insight into the preparation of ‘oxides + carbon’ hybrid electrode materials for energy storage applications.
A simple multiply robust estimator for missing response problem
Authors: Chan Kwun Chuen Gary
Published: August 2013

A multiply robust estimator for a missing response problem is recently proposed that is more robust than doubly robust estimators proposed in the literature. Its formulation is based on empirical likelihood, which solves an implicit Lagrangian equation and often encounters computational problems such as multiple roots or nonconvergence. An alternative multiply robust estimator is proposed, which is computed by least squares and can be implemented easily in practice. We show that this multiply robust estimator is locally semiparametric efficient.Copyright © 2013 John Wiley & Sons Ltd
Über Energieverfahren in der praktischen Baustatik
Authors: Rosemeier Gustav‐Erich
Published: August 2013

Energetisch begründete Gesetze der Baustatik sind unabhängig vom System. Es ist deshalb möglich bei Linien‐ und Flächentragwerken z. B. mit Hilfe von Biegemomentengelenken und des Prinzips der virtuellen Arbeiten zwangläufig kinematisch verschiebliche Gelenkketten einzuführen, deren Ergebnisse mit Lösungen der exakten Theorien praktisch übereinstimmen.

Energetic methods in practical statics. Energetic based laws of statics are independent variables of systems. That is why it is possible for line and plane load‐bearing structures e. g. to introduce bending moment joints in non‐rigid chain links by means of the principle of virtual work. The results of the approximate systems correspond to exact theories.
Tragverhalten und Gebrauchseigenschaften von kaltgefertigten rechteckigen Stahlbau‐Hohlprofilen
Authors: Ritakallio Pekka O.
Published: August 2013

Stahlbau‐Hohlprofile können entweder kalt‐ oder warmgefertigt werden. Aufgrund unterschiedlicher Herstellungsverfahren haben beide Typen unterschiedliche technische Eigenschaften. Mit Hinweis auf die Kaltumformung und die Inhomogenität des Querschnitts wird mitunter die Anwendbarkeit, Schweißbarkeit oder Zuverlässigkeit von kaltgefertigten Hohlprofilen ganz in Frage gestellt. Um eine technisch und wirtschaftlich sinnvolle Produktauswahl zu ermöglichen, werden deshalb verschiedene Einflüsse aus dem Herstellungsverfahren auf die Profileigenschaften und auf die Qualität und Zuverlässigkeit der daraus zu fertigenden Stahlkonstruktion näher beleuchtet. Festzustellen ist, dass gemäß DIN EN 10219 und nach Stand der Technik fachgerecht hergestellte kaltgefertigte Hohlprofile die Anforderungen nach Eurocode 3 an Tragfähigkeit und Dauerhaftigkeit ebenso sicher erfüllen wie warmgefertigte Hohlprofile nach DIN EN 10210. Für eine Vielzahl von Einsatzmöglichkeiten stellen kaltgefertigte Hohlprofile ein wirtschaftliches und zuverlässiges Bauprodukt dar.

Structural performance of cold formed rectangular structural hollow sections. Structural hollow sections can be either cold formed or hot finished. The manufacturing methods of these two products are different and consequently the technical characteristics also vary. The applicability, weldability and reliability of cold formed hollow sections are sometimes questioned because of the consequences of cold forming and inhomogenous cross sections. In order to enable a technically and economically purposeful product selection, various influences of the manufacturing process on the quality and structural performance of the hollow sections are specifically described. It is established that properly manufactured cold formed structural hollow sections according to DIN EN 10219 and the State of the Art fulfil the requirements of Eurocode 3 for static strength and durability just as reliably as hot finished hollow sections according to DIN EN 10210. Cold formed hollow sections offer an economical and reliable structural product for a wide range of applications.
Ein angepasstes Ermüdungslastmodell für stählerne Stabbogenbrücken mit freistehenden Bögen
Authors: Bransch Martin , Priebe Jürgen , Starossek Uwe
Published: August 2013

Bei vorhandenen stählernen Stabbogenbrücken mit freistehenden Bögen werden häufig seitliche Bogenschwingungen festgestellt. Diese resultieren aus kritischen Achsfolgeimpulsen überfahrender Lkw und Resonanz. Vielfach wird ein langes Nachschwingen beobachtet. Hieraus folgt eine große Ermüdungsbeanspruchung für den Bogen und die angrenzenden Bauteile, welche mit den Ermüdungslastmodellen aus den aktuell gültigen DIN‐Fachberichten unzureichend erfasst wird. Um bei Neuplanungen solcher Brücken die große Ermüdungsbeanspruchung zu berücksichtigen, wird hier ein erweitertes Ermüdungslastmodell zur Bemessung vorgeschlagen. Dieses wird ELM 3a genannt und in Anlehnung an die DIN‐Fachberichte aufgestellt. Für das ELM 3a werden ein anpassbarer Achsabstand und eine anpassbare Geschwindigkeit eingeführt, um die Bogenschwingung zu maximieren. In diesem Zusammenhang wird eine vereinfachte Impulsform für die Radlasten angegeben, die z. B. in einer FEM‐Berechnung verwendet werden kann.

An adjustable fatigue load model for steel bowstring bridges with free standing arches. Lateral arch vibrations are frequently observed at existing steel bowstring bridges. These result from critical axle arrangement loads of crossing trucks and resonance. A long post oscillation is often detected. Hence, a large fatigue load for the arch and the adjacent construction components exists, which is included in the actual standards insufficiently. An extended fatigue load model for structural design is presented to incorporate the large fatigue load while planning such bridges. It is called ELM 3a and is based on the fatigue load model 3 given in DIN Fachbericht 101. An adjustable distance between axles and an adjustable speed are introduced for the ELM 3a to maximize the lateral arch vibrations. A simplified impulse form is given for the wheel loads in this context, which can be used in an FEM calculation for example.
Frames with unique global and local imperfection in the shape of the elastic buckling mode (Part 1)
Authors: Chladný Eugen , Stujberová Magdalena
Published: August 2013

The principles and applications of the procedure using the equivalent unique global and local imperfection hinit,m (x) in the shape of the elastic buckling mode given in EN1993‐1‐1:2005, 5.3.2(11) and EN1999‐1‐1:2005 are presented here. The maximum amplitude of such an imperfection is determined from the fundamental requirement: the buckling resistance of the frame structure with axially loaded members only should be equal to the flexural buckling resistance of the equivalent member. The buckling resistance of such a frame is determined by the resistance of its critical cross‐section m with allowance for second‐order effects.

In this paper basic formulas defining the equivalent unique global and local imperfection are established and other formulas useful for easier calculations in practical cases are shown too. Numerical examples provide guidance on the proper application of the procedure presented. The verification of the buckling resistance for the continuous frame in a numerical example shows good agreement with other methods from EN 1993‐1‐1:2005, 5.2.2(3) with application of imperfections according to EN 1993‐1‐1:2005, 5.3.2(3). Full agreement with the method 5.2.2(3)c) of EN 1993‐1‐1:2005 is always reached for individual uniform members with constant axial force along their whole length.

Stabwerke mit einmaliger globaler und lokaler Imperfektion in der Form der elastischen Knickfigur (Teil 1). Die Prinzipen und Anwendungen des Verfahrens, welches die äquivalente, einmalige globale und lokale Imperfektion hinit,m (x) in der Form der elastischen Knickfigur für das gesamte Stabwerk verwendet, wie in EN 1993‐1‐1:2005, 5.3.2(11) und EN 1999‐1‐1:2005, werden hier vorgestellt. Die maximale Amplitude solch einer Imperfektion wird durch folgende grundlegende Bedingung bestimmt: Die Biegeknicktragfähigkeit des nur durch Axialkräfte beanspruchten Stabwerkes soll gleich der Biegeknicktragfähigkeit des Ersatzstabes sein. Die Biegeknicktragfähigkeit dieses Stabwerkes ist durch den Widerstand seines kritischen Querschnitts, unter Berücksichtigung der II. Ordnung‐Effekte, bestimmt.

In diesem Beitrag werden grundsätzliche sowie auch für praktische Anwendung nützliche Formeln abgeleitet und dargestellt. Der Nachweis der Biegeknicktragfähigkeit des Tragwerkes mit steifen Anschlüssen in einem numerischen Beispiel bestätigt gute Übereinstimmung mit anderen Methoden aus EN 1993‐1‐1:2005, 5.2.2(3) unter Anwendung der Imperfektionen nach EN 1993‐1‐1:2005, 5.3.2(3). Volle Übereinstimmung mit der Methode 5.2.2(3)c) der EN 1993‐1‐1:2005 ist immer erreicht bei individuellen Stäben mit konstantem Querschnitt und gleichmäßiger Druckkraft.
NürnbergMesse – neuer Eingang Mitte
Authors: Stumpf Martin , Reinhardt Achim
Published: August 2013

Der ehemalige Eingang Mitte der NürnbergMesse wurde seiner Rolle als Haupteingang nicht gerecht. Von außen schwer ablesbar, führte der niedrige Eingangsraum in eine unübersichtliche Gebäudestruktur. Anstatt der seit den 60er Jahren mehrfach ergänzten Messelandschaft lediglich einen weiteren additiven Baustein hinzuzufügen, schafft der Entwurf von kadawittfeldarchitektur mit dem 250 m langen und 57 m breiten Lamellendach ein neues Superzeichen, das mehrere Funktionen gleichzeitig erfüllt: Es ordnet die verschiedenen Bauteile der Messe, gibt ihr eine eindeutige Adresse, verbindet Innen‐ und Außenräume und definiert ein urbanes Foyer, das sich von der Zufahrt über den Vorplatz, den Eingang und das Hauptfoyer bis in den neuen Messepark erstreckt.

Trade fair centre of Nuremberg – new main entrance. The entrance called “Mitte” of Nuremberg’s trade fair centre did not do justice to its purpose as the main entrance. Barely perceptible from the outside, the low‐ceilinged lobby led into building structure. Instead of simply adding another module to the existing trade fair compound built in the 1960s, the draft of kadawittfeldarchitektur sets up a new super‐feature: The 20 m high steel slat roof measuring 256 by 57 m spans the forecourt of the trade fair and forms the roof of the new entrance building.
Mehrgeschossiger Leichtbau: Aufstockung des Fahrzeug‐Logistic‐Centers Galliker
Authors: Brux Gunther
Published: August 2013

Eine bestehende Fahrzeughalle sollte bei Nutzung der vorhandenen Struktur in sehr kurzer Zeit wesentlich vergrößert werden. Dabei wurden innovative Systeme von der Planung bis zur Umsetzung genutzt, wie das Verbunddeckensystem ArcelorMittal und die neue Brandschutztechnologie Sika Unitherm platinum sowie angepasste Parkdeckbeschichtungen für dauerhafte Nutzungen.