bluuebunny/crossref_metadata_2025_split huggingface dataset:
The stress protein ERp57/GRP58 binds specific DNA sequences in HeLa cells
Authors: Chichiarelli Silvia , Ferraro Anna , Altieri Fabio , Eufemi Margherita , Coppari Sabina , Grillo Caterina , Arcangeli Valentina , Turano Carlo 
Published: October 2006

AbstractThe protein ERp57/GRP58 is a member of the protein disulfide isomerase family and is also a glucose‐regulated protein, which, together with the other GRPs, is induced by a variety of cellular stress conditions. ERp57/GRP58 is mainly located in the endoplasmic reticulum (ER), but has also been found in the cytoplasm and in the nucleus, where it can bind DNA. In order to identify a possible correlation between the stress‐response and the nuclear location of ERp57/GRP58, its binding sites on DNA in HeLa cells have been searched by chromatin immunoprecipitation and cloning of the immunoprecipitated DNA fragments. Following sequencing of the cloned fragments, 10 DNA sequences have been securely identified as in vivo targets of ERp57/GRP58. Nine of them are present in the non‐coding regions of identified genes, and seven of these in introns. The features of some of these DNA sequences, that is, DNase hypersensitivity, proximity of MAR regions, and homology to the non‐coding regions of orthologue genes of mouse or rat, are compatible with a gene expression regulatory function. Considering the nature of the genes concerned, two of which code for DNA repair proteins, we would suggest that at least part of the mechanism of action of ERp57/GRP58 takes place through the regulation of these, and possibly other still unidentified, stress‐response genes. J. Cell. Physiol. 210: 343–351, 2007. © 2006 Wiley‐Liss, Inc.
Novel Branched Polyphenylenes based on A2/B3 and AB2/AB Monomers via Diels‐Alder Cycloaddition
Authors: Stumpe Katrin , Komber Hartmut , Voit Brigitte I. 
Published: October 2006

AbstractSummary: Novel hyperbranched polyphenylenes based on both an A2 + B3 and an AB2 + AB approach were synthesised and characterised. Different monomers were prepared and polymerised using a Diels‐Alder reaction with subsequent decarbonylation. The polymer backbones consist of hexaphenylbenzene units which are linked in different positions and functionalised by cyclopentadienone (A) and/or alkyne groups (B) depending on the monomer ratio. The structure and properties of the resulting polymers were compared to those of hyperbranched polyphenylenes based solely on an AB2 monomer. All branched products showed high thermal stability and good solubility in common organic solvents such as chloroform or toluene. However, due to steric hindrance, the polyphenylenes produced using the A2 + B3 approach exhibited a high percentage of linear units within the polymer structure.Schematic structure of hyperbranched polyphenylenes from A2 and B3 monomers.magnified imageSchematic structure of hyperbranched polyphenylenes from A2 and B3 monomers.
Cyclopentadienyl Nickel and Palladium Complexes/Activator System for the Vinyl‐Type Copolymerization of Norbornene with Norbornene Carboxylic Acid Esters: Control of Polymer Solubility and Glass Transition Temperature
Authors: Kaita Shojiro , Matsushita Kumiko , Tobita Morika , Maruyama Yooichiroh , Wakatsuki Yasuo 
Published: October 2006

AbstractSummary: In non‐polar solvents such as toluene, Cp‐Ni and ‐Pd complexes (Cp = η5‐C5H5) with appropriate activators have been found to induce the addition polymerization of norbornene in excellent yields, for example (Cp)Pd(allyl)/[Ph3C][B(C6F5)4] gave 105 120 kg‐polymer/cat‐mol · h at room temperature. While the Cp‐Pd system was not suitable in the presence of ester‐substituted norbornenes, the Cp‐Ni system, for example (Cp)Ni(Cl)(PPh3)/AlMe3/B(C6F5)3 can copolymerize norbornene with 5‐norbornene‐2‐carboxylic acid methyl ester in toluene to give high yields (up to 68% in 2 h at room temperature) of copolymer with variable contents of the methyl ester monomer unit (17.4–60.7 mol‐%). These copolymers have high molecular weights ($\overline M _{\rm n}$ = 234 100–109 500) and narrow molecular weight distributions ($\overline M _{\rm w} /\overline M _{\rm n}$ = 1.78–1.89). In addition, they are soluble in common organic solvents giving flexible and transparent films on casting, that show very high Tg in the range of 352.8 to 316.0 °C. The same Ni‐catalyst system can also copolymerize norbornene derivatives with bulky substituents, i.e., 2‐butyl‐5‐norbornene and 5‐norbornene‐2‐carboxylic acid butyl ester. The Tg of these copolymers are lower (294.9–267.3 °C) than the methyl ester‐based copolymers, demonstrating that the Tg of the polynorbornene copolymer film can be tailored simply by changing the alkyl group of the monomer to within the range of 352 to 267 °C.Figure showing the addition polymerization of norbornene using Cp‐Ni complex with appropriate activators.magnified imageFigure showing the addition polymerization of norbornene using Cp‐Ni complex with appropriate activators.
Novel Photo‐Crosslinkable Light‐Emitting Rod/Coil Copolymers: Underlying Facile Material for Fabricating Pixelated Displays
Authors: Qiang Liangliang , Ma Zhun , Zheng Zhe , Yin Rong , Huang Wei 
Published: October 2006

AbstractSummary: Photo‐crosslinkable PF‐b‐PCEA triblock copolymers have been successfully synthesized by an end‐capped Yamamoto reaction and further atom transfer radical polymerization. The copolymer film on a glass substrate could be selectively photo‐crosslinked using 365 nm UV radiation and a mask with a standard photopattern process. Elaborate and complex pixel structures are easily obtained, which may be applied to fabricate pixelated matrix displays and large area displays in the future. Furthermore, the crosslinked PF‐b‐PCEA film shows better stability under thermal stress and UV irradiation than the homopolymer, which indicates that the block copolymers could have a longer lifetime and stability when they are used in OLED fabrication. The optical properties and conversion of the photo‐responsive group are also investigated by various methods and confirm the photo‐responsive property. The corresponding results show that many other types of photo‐crosslinkable light‐emitting materials can be conveniently and efficiently obtained by this method.“Fudan university badge” feature obtained by photolithography.magnified image“Fudan university badge” feature obtained by photolithography.
Synthesis of Water‐Soluble Dendritic Conjugated Polymers for Fluorescent DNA Assays
Authors: Yu Minghui , Tang Yanli , He Fang , Wang Shu , Zheng Dagui , Li Yuliang , Zhu Daoben 
Published: October 2006

AbstractSummary: Cationic water‐soluble dendritic poly(fluorene)s with positively charged amines on the exterior (PFP‐G0–2) can be prepared by a macromonomer (generation‐by‐generation) approach. The charge densities of PFP‐G0–2 can control their distances to DNA by electrostatic interactions. The PFP‐G2 with higher generation of dendritic side chains possesses a higher charge density, and gives rise to efficient fluorescence resonance energy transfer (FRET) to a signaling fluorescein labeled at the terminus of DNA. These new conjugated polymers form less aggregates and yield more efficient FRET in a tetrahydrofuran/H2O mixed solvent as compared to in pure water. The sensitivity of the DNA sensor is improved by utilizing highly dendritic conjugated polymers.Structure of the dendritic conjugated polymer PFP‐G2.magnified imageStructure of the dendritic conjugated polymer PFP‐G2.
Fixed points of order‐reversing maps in ℝ and chemical equilibrium
Authors: Gnacadja Gilles 
Published: October 2006

AbstractThe problem of computing the equilibrium state of a reversible chemical reaction network has a natural interpretation as a fixed‐point problem. Several authors have used fixed‐point iterations in this context, yet there are no comprehensive investigations into the convergence of the algorithm. We address this void by studying the larger problem of the existence and uniqueness of fixed points, and the convergence of fixed‐point iterations, for order‐reversing maps in ℝ. By using the Thompson metric, we are able to apply fixed‐point theorems based on the Lipschitz condition and obtain upper bounds on judiciously defined approximation errors. Copyright © 2006 John Wiley & Sons, Ltd.
Modelling surface orientation and stress at failure of concrete and geological materials
Authors: Schreyer Howard L. 
Published: October 2006

AbstractIn the numerical simulation of failure for structures, crack initiation is normally based on a criterion that provides both the stress and the orientation of the material failure plane. Most constitutive models provide reasonably good criteria for stress, but the predictions of orientation are often at variance with experimental data. If a crack initiates in the wrong direction, it is likely that the direction of propagation will also be in error.The object of this paper is to describe an anisotropic decohesion function that provides predictions of both stress and failure orientation which are in good agreement with basic features of experimental data. The essential new feature is the addition to the decohesion function of components of stress that are not part of the traction vector on the material failure surface. The result is that a given decohesion surface describes two general regimes of failure. For the first, the normal to the material failure surface is in a direction of principal stress, not necessarily the maximum principal stress. The second involves shear for which there exists two or more solutions for the normal. Typically, the normal vector forms positive and negative angles of equal magnitude with a principal direction of stress and the angle varies continuously with stress. Experimental data for concrete and ice are used as representative examples for isotropic and anisotropic materials, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Gas‐solid Two‐phase Mixtures Flowing Upward through a Confined Packed Bed
Authors: He Yurong , Ngoc Cong Thang , Ding Yulong 
Published: October 2006

AbstractThis paper deals with flows of a gas‐solid two‐phase mixture through a confined packed bed. Both experimental work and numerical modelling are performed on the behaviour of suspended particles within the packed bed. The experimental work is carried out with a non‐intrusive Positron Emission Particle Tracking (PEPT) technique, which tracks particle motion at the single particle level for a prolonged period thus allows both the microscopic and macroscopic solids behaviour to be analysed under the steady‐state conditions. A continuous based model is used to simulate the flow behaviour. The model uses a newly proposed porosity model and treats the suspended and packed particles as a binary mixture with the packed particles being at zero velocity. The results show that the model captures the main features of solids behaviour in terms of the radial distributions of the suspended particle concentration and the axial solids velocity. Both the experiments and modelling suggest that the wall effect on the motion of suspended particles be limited to a small region close to the wall (∼0.5–1 packed particle diameter). However, deviations exist between the model predictions and experiments; more work is therefore proposed to improve the interaction terms in the model between the suspended and packed particles.
MRI Measurement of Granular Motion in a Rotating Drum
Authors: Kawaguchi Toshihiro , Tsutsumi Kenji , Tsuji Yutaka 
Published: October 2006

AbstractIt is generally difficult to measure the particle motion inside of dense granular flows or fluid‐particle flows. In the present paper, an MRI (Magnetic Resonance Imaging) technique is employed to measure the granular motion inside a rotating horizontal drum. A horizontal drum is half‐filled with a mixture of two different sizes of spherical particles, and is steadily rotated along its axis. A typical radial segregation phenomenon, i.e., smaller particles concentrate to the central part and larger particles distribute in the peripheral part, was observed in vertical cross sections. When a tapered drum was used, in addition to the radial segregation, an axial segregation was also observed. The effect of the inclination angle of the drum wall on the segregation phenomena was studied. Furthermore the effect of the rotational speed on the axial segregation phenomena was also studied.
Synthesis of single wall carbon nanotubes with defined 13C content
Authors: Kramberger C. , Löffler M. , Rümmeli M. , Grüneis A. , Schönfelder R. , Jost O. , Gemming T. , Pichler T. , Büchner B. 
Published: October 2006

AbstractThe synthesis of high quality isotope engineered SWCNT by means of laser ablation and the use of Pt‐Rh‐Re catalyst mixtures has been established. Optical absorption and Raman spectroscopy as well as transmission electron microscopy are utilized to characterize the obtained SWCNTs with regard to purity and yield. The absence of any ferromagnetic materials, as well as the remarkably low abundance of amorphous carbon renders this material ideal for magnetic studies. The controlled augmentation of 13C is conveniently confirmed by phonon softening and broadening observed in Raman spectroscopy. Isotope labelling at constant sample quality was achieved in the whole range from 1% 13C up to 98% 13C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Precise, molecularly thin semiconductor shells: from nanotubes to nanocorrugated quantum systems
Authors: Prinz V. Ya. 
Published: October 2006

AbstractThis brief overview focuses on the fabrication methods and properties of semiconductor and metal nanoshells based on self‐rolling or buckling of strained ultrathin films. Previously, it was shown that thin epitaxial heterofilms (down to two monolayers for InGaAs/GaAs) can be controllably released from the substrates and converted into micro‐ and nanoshells, including tubes and corrugations. The diameter of the tubes obtained was down to 2 nm, and the period of the nanocorrugated systems was down to 10 nm. New results for quantum confinement in semiconductor and hybrid nanoshells and for fabrication of complex nanoshells are reported. Possible extension of this approach to the case of carbon shells is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge distribution of potassium intercalated Dy3N@C80 observed with core‐level and valence‐band photoemission
Authors: Shiozawa H. , Rauf H. , Grimm D. , Knupfer M. , Kalbac M. , Yang S. , Dunsch L. , Büchner B. , Pichler T. 
Published: October 2006

AbstractA photoemission study of potassium intercalated trimetal‐nitride fullerene Dy3N@C80 is reported. A continuous electron doping to the carbon cage with increasing potassium intercalation levels is observed as shape changes in the carbon‐sensitive ultra‐violet photoemission spectrum. X‐ray photoemission shows that the valence electronic state of the trivalent Dy ions is not affected by the additional charge in the fullerene cage. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro evaluation of possible adverse effects of nanosized materials
Authors: Wick P. , Manser P. , Spohn P. , Bruinink A. 
Published: October 2006

AbstractNanoscaled materials, such as single walled carbon nanotubes (SWCNT), are increasingly used in a wide range of areas because of their unique characteristics. Presently, it is not clear to what extent these materials have an adverse effect if they are taken up by humans. Because of their dimensions and persistency, SWCNT have been compared with asbestos. In the present study, an in vitro system was used to compare the effects of SWCNT and asbestos. With the short term tests used, some similarities in the induced effects could be detected. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cavity QED with a single QD inside an optical microcavity
Authors: Peter E. , Bloch J. , Martrou D. , Lemaître A. , Hours J. , Patriarche G. , Cavanna A. , Gérard J. M. , Laurent S. , Robert‐Philip I. , Senellart P. 
Published: October 2006

AbstractTo demonstrate strong coupling regime for a single quantum dot inside an optical microcavity, large oscillator strength quantum dots are needed. We show that quantum dots formed by the interface fluctuations of a thin GaAs quantum well are ideal systems for this purpose since they can present an oscillator strength larger than 100. By inserting a GaAs QD inside a state of the art microdisk microcavity, we demonstrate the strong coupling regime with a Rabi splitting of 400 µeV. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards a mid‐infrared polaron laser using InAs/GaAs self‐assembled quantum dots
Authors: Sauvage S. , Boucaud P. , Bras F. , Fishman G. , Ortéga J.‐M. , Gérard J.‐M. , Patriarche G. , Lemaître A. 
Published: October 2006

AbstractA three level scheme based on S–P polaron intersublevel transitions in n‐doped InAs/GaAs self‐assembled quantum dots is proposed to obtain laser effect around 25 µm wavelength under optical pumping. Temperature dependence of the optical gain is theoretically analysed. Lasing effect is expected up to 300 K. To probe the T 2 decoherence time, one of the key parameter driving the laser performances, an optical Rabi oscillation experiment is performed on the pumping transition. Transmission variation is measured as a function of the pump pulse area and modelled by 2‐level optical Bloch equations considering inhomogeneous contributions. We show that the non‐monotonous population dependence and damping of the oscillation is only compatible with a T 2 ∼ 5 ps dephasing time, one order of magnitude longer than in quantum wells and one order of magnitude shorter than the 45 ps relaxation time of the S–P transition, demonstrating a non relaxation‐limited decoherence for the transition. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of GaN quantum dots on nonpolar A ‐plane SiC by molecular‐beam epitaxy
Authors: Founta S. , Rol F. , Bellet‐Amalric E. , Sarigiannidou E. , Gayral B. , Moisson C. , Mariette H. , Daudin B. 
Published: October 2006

AbstractWe report on A ‐plane GaN quantum dots in AlN, grown on A ‐plane 6H SiC substrates by plasma‐assisted molecular‐beam epitaxy. AFM imaging revealed a strong alignment of the dots along the [1$ \bar 1 $00] direction that we correlated with the anisotropic morphology of the AlN buffer layer. A vertical correlation of these dots was evidenced by high resolution transmission electron microscopy on superlattice samples with an AlN spacer thickness of 5 nm. Time‐resolved spectroscopy performed on both C ‐plane and A ‐plane samples revealed much shorter radiative lifetimes for the A ‐plane dots, indicating a strong reduction of the internal electric field with respect to the one present in their C ‐plane counterparts. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrafast emission under two‐photon excitation of biexcitons in CuCl quantum dots
Authors: Miyajima K. , Kagotani Y. , Saito S. , Ashida M. , Itoh T. 
Published: October 2006

AbstractTime‐resolved photoluminescence spectra of biexcitons confined in CuCl quantum dots have been measured by means of an optical Kerr‐gate method. When the biexcitons are generated by resonant two‐photon excitation, a new ultrashort photoluminescence is observed. This result indicates that the resonant two‐photon excitation of the biexcitons induces a new transition process with a large optical nonlinearity which is characteristic for the direct generation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minimization of 𝓁2norm of the error signal in posicast input command shaping: a polynomial approach
Authors: Hurák Z. , Hromčík M. , Špiller M. 
Published: October 2006

AbstractIn this paper, design of a posicast input command shaper is formulated in discrete‐time domain as minimization of 𝓁2norm of the error sequence. This optimization task is solved by simple algebraic manipulation with polynomials, namely, solving two‐sided linear equations with polynomials and modular shift of a polynomial. Numerical examples are given to demonstrate properties of the optimal design in contrast with the classical Smith's design technique achieving complete cancellation of residual vibrations. Copyright © 2006 John Wiley & Sons, Ltd.
Quantifying spatial correlations in extinction risk for an aphid metapopulation
Authors: Hudgens Brian R. 
Published: October 2006

AbstractMetapopulation persistence depends on dispersal offsetting local extinction risks. The mitigating power of dispersal to offset local extinction risks is substantially reduced if extinction risks are highly spatially correlated. Extinction risks are likely to be spatially correlated when mechanisms driving local extinction act on large spatial scales, such as climatic events or far‐ranging predators. In this paper I develop a method to quantify spatial correlations in local extinction risks within a region. I then show that colonies of the aphidAphis lugentiswithin clusters of their host plant,Senecio bigelovii, do not have strong spatial correlations in extinction risks, even though the primary mechanism for colony extinction is over‐predation by far‐ranging predators (ladybugs and syrphid flies). Consequently, dispersal potentially plays an important role offsetting local extinction. Aphids did experience a weak, but significantly positive correlation in extinction risk in one of the two years of this study as well as increasing extinction risks across all plant clusters in both years. These observations point to important gaps in our understanding of how population synchrony affects metapopulation persistence.
Incidence and Predictors of Difficult and Impossible Mask Ventilation
Authors: Kheterpal Sachin , Han Richard , Tremper Kevin K. , Shanks Amy , Tait Alan R. , O’Reilly Michael , Ludwig Thomas A. 
Published: October 2006

Background
Mask ventilation is an essential element of airway management that has rarely been studied as the primary outcome. The authors sought to determine the incidence and predictors of difficult and impossible mask ventilation.

Methods
A four-point scale to grade difficulty in performing mask ventilation (MV) is used at the authors' institution. They used a prospective, observational study to identify cases of grade 3 MV (inadequate, unstable, or requiring two providers), grade 4 MV (impossible to ventilate), and difficult intubation. Univariate and multivariate analyses of a variety of patient history and physical examination characteristics were used to establish risk factors for grade 3 and 4 MV.

Results
During a 24-month period, 22,660 attempts at MV were recorded. 313 cases (1.4%) of grade 3 MV, 37 cases (0.16%) of grade 4 MV, and 84 cases (0.37%) of grade 3 or 4 MV and difficult intubation were observed. Body mass index of 30 kg/m or greater, a beard, Mallampati classification III or IV, age of 57 yr or older, severely limited jaw protrusion, and snoring were identified as independent predictors for grade 3 MV. Snoring and thyromental distance of less than 6 cm were independent predictors for grade 4 MV. Limited or severely limited mandibular protrusion, abnormal neck anatomy, sleep apnea, snoring, and body mass index of 30 kg/m or greater were independent predictors of grade 3 or 4 MV and difficult intubation.

Conclusions
The authors observed the incidence of grade 3 MV to be 1.4%, similar to studies with the same definition of difficult MV. Presence of a beard is the only easily modifiable independent risk factor for difficult MV. The mandibular protrusion test may be an essential element of the airway examination.