bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Cytotoxicity Studies of Fluorinated Derivatives of Vanadocene Y
Authors: Gleeson Brendan , Claffey James , Deally Anthony , Hogan Megan , Méndez Luis Miguel Menéndez , Müller‐Bunz Helge , Patil Siddappa , Wallis Denise , Tacke Matthias 
Published: May 2009

AbstractFrom the reaction of 6‐(2‐fluoro‐4‐methoxyphenyl)fulvene (1a), 6‐(3‐fluoro‐4‐methoxyphenyl)fulvene (1b) and 6‐[4‐(trifluoromethoxy)phenyl]fulvene (1c) with LiBEt3H, lithiated cyclopentadienide intermediates (2a–c) were synthesised. These intermediates were then transmetallated to vanadium with VCl4 to yield the benzyl‐substituted vanadocenes bis[(2‐fluoro‐4‐methoxybenzyl)cyclopentadienyl]vanadium(IV) dichloride (3a), bis[(3‐fluoro‐4‐methoxybenzyl)cyclopentadienyl]vanadium(IV) dichloride (3b), and bis[(4‐trifluoromethoxybenzyl)cyclopentadienyl]vanadium(IV) dichloride (3c). The three vanadocenes 3a–c were characterised by single‐crystal X‐ray diffraction. All three vanadocenes had their cytotoxicity investigated through MTT‐based preliminary in‐vitro testing on the LLC‐PK and Caki‐1 cell lines in order to determine their IC50 values. Vanadocenes 3a–c were found to have IC50 values of 6.0 (+/–4), 35 (+/–7) and 13 (+/–3) μM on the LLC‐PK cell line and IC50 values of 78 (+/–11), 18 (+/–16) and 2.2 (+/–0.5) μM on the Caki‐1 cell line respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
STAT3 activation contributes directly to Epstein‐Barr virus–mediated invasiveness of nasopharyngeal cancer cells in vitro
Authors: Lui Vivian Wai Yan , Wong Elaine Yue Ling , Ho Yeung , Hong Bo , Wong Sze Chuen Cesar , Tao Qian , Choi Gigi Ching Gee , Au Thomas Chi Chuen , Ho Kakiu , Yau Daisy Mei Sze , Ma Brigette Buig Yue , Hui Edwin Pun , Chan Andrew Sai‐Kit , Tsang Chi‐Man , Tsao Sai‐Wah , Grandis Jennifer Rubin , Chan Anthony Tak‐Cheung 
Published: May 2009

AbstractNasopharyngeal cancer (NPC) is an Epstein‐Barr virus (EBV)‐associated head and neck cancer prevalent in Asia. Although with reasons not fully understood, the intrinsic invasiveness of NPC is believed to be EBV‐linked. Recently, EBV was found to induce STAT3 activation. Constitutive STAT3 activation correlated with advanced clinical staging in NPC. We hypothesized that STAT3 activation by EBV directly contributes to the intrinsic invasiveness of NPC cells. Phospho‐STAT3‐Tyr705 was detected in high percentage of NPC tumors (7/10 cases). Using a paired NPC cell line model, HONE‐1 and the EBV‐infected counterpart, HONE‐1‐EBV, we found that HONE‐1‐EBV expressed a higher level of phospho‐STAT3‐Tyr705 and was ∼11‐fold more invasive than HONE‐1. In HONE‐1‐EBV, STAT3 siRNA targeting inhibited both spontaneous and serum‐induced invasion, as well as cell growth. Conversely, activation of STAT3 (by expressing an activated STAT3 mutant, namely STAT3C) in the parental HONE‐1, mimicking EBV‐induced STAT3 activation, significantly enhanced its invasiveness and proliferation, which was accompanied by increased expression of markers of mesenchymal status, proliferation and anti‐apoptosis. Our results demonstrated that EBV‐induced STAT3 activation is responsible for NPC cell proliferation and invasion. This was further confirmed by a small molecule inhibitor of JAK/STAT3, JSI‐124. JSI‐124 inhibited STAT3 activation in HONE‐1‐EBV, with subsequent growth inhibition, induction of PARP cleavage, abrogation of anchorage‐independent growth and invasion. We found that EBV‐independent activation of STAT3 by a growth factor, EGF, also contributed to NPC invasion. In conclusion, EBV‐induced STAT3 activation directly contributes to the intrinsic invasiveness of NPC cells and STAT3 targeting may be beneficial in treating aggressive NPC. © 2009 UICC
The nonexistence of a (K6‐e)‐decomposition of the complete graph K29
Authors: Hartke S. G. , Östergård P. R. J. , Bryant D. , El‐Zanati S. I. 
Published: May 2009

AbstractWe show via an exhaustive computer search that there does not exist a (K6−e)‐decomposition of K29. This is the first example of a non‐complete graph G for which a G‐decomposition of K2|E(G)|+1 does not exist. © 2009 Wiley Periodicals, Inc. J Combin Designs 18: 94–104, 2010
Free‐shape 14C age–depth modelling of an intensively dated modern peat profile
Authors: Goslar Tomasz , Van Der Knaap Willem O. , Kamenik Christian , Van Leeuwen Jacqueline F. N. 
Published: May 2009

AbstractThe paper presents a new algorithm for finding the best‐fit age–depth model of a peat profile dated with 14C. This algorithm of free‐shape modelling is useful when the age–depth curve is wiggly and difficult to approximate by a simple mathematical function. The performance of the free‐shape algorithm is illustrated with the example of the MA2 peat profile from Mauntschas mire, using 29 radiocarbon dates spanning the last 1300 a, and where the age–depth curve revealed a relatively complicated shape.The best‐fit age–depth model searched for is a curve maximising the ‘Fit quality’, defined as a combination of fit of 14C dates to the radiocarbon calibration curve, general smoothness of the age–depth line, and similarity of relative changes in the modelled sediment accumulation rates to those suggested by independent data. The algorithm of free‐shape age–depth modelling searched for a reasonable equilibrium or compromise between the conditions above. Uncertainty of the free‐shape model was assessed with a Monte Carlo Markov chain built from large number of age–depth lines accepted with probabilities dependent on the ‘fit quality’ defined as above.Parallel fluctuations in concentrations of most pollen taxa in MA2 strongly suggest a complicated shape of the age–depth curve, which is supported in the upper part of the profile by the record of spheroidal carbonaceous particles, and in some levels also by the 14C dates. A modification of total pollen concentrations was therefore used as a quantitative indicator of relative changes of the peat accumulation rate. The use of pollen concentrations improved the fit of the 14C dates in several cases.Application of the final age–depth model to the pollen data resulted in a diagram of pollen accumulation which allows interpretation in ecological terms, whereas age–depth models that did not use pollen concentrations led to problematic and confusing results. The obtained age–depth model is therefore accepted as a good approximation of the actual conditions. Copyright © 2009 John Wiley & Sons, Ltd.
Investigation of the effect of CrO and MoO on carbon steel corrosion using AFM and electrochemical techniques
Authors: Chen Z. , Guo X. , Zhang X. , Huang L. 
Published: May 2009

AbstractThe effect of chromate (${\rm CrO}_4^{2 - }$) and molybdate (${\rm MoO}_4^{2 - }$) ions on the corrosion of carbon steel in 0.5 M NaCl solution has been studied using electrochemical measurements and atomic force microscopy (AFM) technique. Potentiodynamic polarization data suggest that both ${\rm CrO}_4^{2 - }$ and ${\rm MoO}_4^{2 - }$ have inhibition effect on carbon steel corrosion, and the inhibition efficiency increases with increase in concentrations of ${\rm CrO}_4^{2 - }$ and ${\rm MoO}_4^{2 - }$; at the same concentration, the inhibition efficiency of ${\rm CrO}_4^{2 - }$ is higher than that of ${\rm MoO}_4^{2 - }$. The increase in concentrations of ${\rm CrO}_4^{2 - }$ and ${\rm MoO}_4^{2 - }$ anions causes a shift of the breakdown potential (Eb) in the positive direction, indicating the inhibitive effect of the added anions on the pitting attack. At the same concentrations, the breakdown potential of ${\rm CrO}_4^{2 - }$ is higher than that of ${\rm MoO}_4^{2 - }$. Electrochemical impedance spectroscopy (EIS) tests reveal that the charge transfer resistance and passive film resistance increase with increase in concentrations of ${\rm CrO}_4^{2 - }$ or ${\rm MoO}_4^{2 - }$; at the same concentrations, as for ${\rm CrO}_4^{2 - }$ the charge transfer resistance and passive film resistance were bigger than those of ${\rm MoO}_4^{2 - }$. AFM imaging technique shows that local corrosion was inhibited obviously after the addtion of ${\rm CrO}_4^{2 - }$ or ${\rm MoO}_4^{2 - }$, and passive film of ${\rm CrO}_4^{2 - }$ was much more compact than that of ${\rm MoO}_4^{2 - }$. AFM force–distance curves indicate that the passive film of ${\rm CrO}_4^{2 - }$ is much stiffer than that of ${\rm MoO}_4^{2 - }$.
Influence of laser‐glazing on hot corrosion resistance of yttria‐stabilized zirconia TBC in molten salt mixture of V2O5 and Na2SO4
Authors: Zhong X. , Wang Y. , Xu Z. , Zhang Y. , Zhang J. , Cao X. 
Published: May 2009

AbstractPlasma‐sprayed 8YSZ (zirconia stabilized with 8 wt% yttria)/NiCoCrAlYTa thermal barrier coatings (TBCs) were laser‐glazed using a continuous‐wave CO2 laser. Open pores within the coating surface were eliminated and an external densified layer was generated by laser‐glazing. The hot corrosion resistances of the plasma‐sprayed and laser‐glazed coatings were investigated. The two specimens were exposed for the same period of 100 h at 900 °C to a salt mixture of vanadium pentoxide (V2O5) and sodium sulfate (Na2SO4). Serious crack and spallation occurred in the as‐sprayed coating, while the as‐glazed coating exhibited good hot corrosion behavior and consequently achieved a prolonged lifetime. The results showed that the as‐sprayed 8YSZ coating achieved remarkably improved hot corrosion resistance by laser‐glazing. Changes in the coatings were studied by scanning electron microscopy (SEM) to observe the microstructure and X‐ray diffraction (XRD) technique to analyze the phase composition. XRD results showed that the reaction between yttria (Y2O3) and V2O5 produced yttrium vanadate (YVO4), leaching Y2O3 from YSZ and causing the progressive destabilization transformation from the tetragonal (t) to monoclinic (m) phase. The external dense layer produced by laser‐glazing restrained the penetration of the molten salt, to a certain extent, into the coating, which led to a relatively low m‐ZrO2 content in the coating after the hot corrosion test. Additionally, the segmented cracks in the coating surface induced by laser‐glazing were helpful to the improvement of strain tolerance of the coating. The two factors were important contributions to the significant enhancement of hot corrosion resistance of the as‐glazed YSZ coating.
Corrosion monitoring of hydrogen by HUP probe in the presence of sulphide and thiourea
Authors: Abbassi A. , Mihi A. , Benbouta R. 
Published: May 2009

AbstractThe effect of sulphide and thiourea on hydrogen uptake during the corrosion of steel in deaerated pH3 has been studied using an electrochemical hydrogen probe incorporating a solid electrolyte (HUP) and lead dioxide (PbO2) as a reference electrode. This probe has been used for the quantitative determination of the hydrogen activity generated during the corrosion of steel. The sensor voltage implies an average equivalent hydrogen pressure in uncharged steel of 2 × 10−18 atmospheres. During the corrosion of steel, this value increases by very large amounts; thus in deaerated pH3, the equivalent pressure rose by 1024.5 in the presence of 200 ppm sulphide and by 102 in the presence of 100 ppm thiourea. Weight loss and AC impedance methods were also performed under the same conditions as the hydrogen measurements. The hydrogen probe data were correlated with a.c impedance and weight loss results in order to understand the effect of S2− and thiourea on hydrogen uptake.
Cluster secondary ion mass spectrometry of polymers and related materials
Authors: Mahoney Christine M. 
Published: May 2009

AbstractCluster secondary ion mass spectrometry (cluster SIMS) has played a critical role in the characterization of polymeric materials over the last decade, allowing for the ability to obtain spatially resolved surface and in‐depth molecular information from many polymer systems. With the advent of new molecular sources such as ${\rm C}_{60}^ +$, ${\rm Au}_3^ +$, ${\rm SF}_5^ +$, and ${\rm Bi}_3^ +$, there are considerable increases in secondary ion signal as compared to more conventional atomic beams (Ar+, Cs+, or Ga+). In addition, compositional depth profiling in organic and polymeric systems is now feasible, without the rapid signal decay that is typically observed under atomic bombardment. The premise behind the success of cluster SIMS is that compared to atomic beams, polyatomic beams tend to cause surface‐localized damage with rapid sputter removal rates, resulting in a system at equilibrium, where the damage created is rapidly removed before it can accumulate. Though this may be partly true, there are actually much more complex chemistries occurring under polyatomic bombardment of organic and polymeric materials, which need to be considered and discussed to better understand and define the important parameters for successful depth profiling. The following presents a review of the current literature on polymer analysis using cluster beams. This review will focus on the surface and in‐depth characterization of polymer samples with cluster sources, but will also discuss the characterization of other relevant organic materials, and basic polymer radiation chemistry. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:247–293, 2010
Toughening and brittle‐tough transition in blends of an amorphous polyamide with a modified styrene/ethylene‐butylene/styrene triblock copolymer
Authors: González I. , Eguiazábal J.I. , Nazábal J. 
Published: May 2009

AbstractAmorphous polyamide (aPA)/maleated styrene/ethylene‐butylene/styrene triblock copolymer (mSEBS) blends with a mSEBS content up to 25% were obtained in the melt state with the aim of toughening the notch sensitive pseudoductile matrix, and of studying the parameters that influence the morphology that leads to the brittle/tough transition. The increase in the Tg of the rubbery phase, which depended on the maleinized copolymer content, indicated the presence of reacted copolymers. These copolymers should decrease the interfacial tension, thus allowing the presence of a fine dispersed particle size. The impressive (27‐fold) toughness increase observed, which is among the largest observed in toughened blends, took place at 15% mSEBS content. The critical interparticle distance (τc) of the blends was smaller than that of polyamide 6 (PA6)/mSEBS blends tested at the same conditions. Having ruled out the possible influence of other parameters, the lower τc of the aPA/mSEBS blends of this study is attributed to their higher interfacial adhesion that was inferred by the calculation of the solubility parameters and by the measured interfacial toughness. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Mechanism of interactions of eggshell microparticles with epoxy resins
Authors: Ji Genzhong , Zhu Hongqi , Qi Chenze , Zeng Minfeng 
Published: May 2009

AbstractLarge surface‐area microparticles of natural chicken eggshell were prepared and characterized to illustrate how such particles can improve the toughness of epoxy resins. A small amount of organic compounds, in particular proteins, were found to be present in the microparticles and beneficial to the enhancement of the mechanical properties of the epoxy resins. Scanning electron microscopic analysis of the rough fracture surfaces show that there are full of plastic deformation, voids, cavities, and debonding phenomena in the microparticle‐filled composites. Positron annihilation study indicates that the lifetime of τ3 o‐Ps varies and the corresponding intensity of I3 becomes weak with the increase of eggshell particle content, which indicates that there is a good interaction between the epoxy resin and the filling particles. This gives rise to significant improvement in the toughness of the filled resin. The impact strength of the epoxy resin composite reaches 16.7 kJ/m2 compared with 9.7 kJ/m2 of neat epoxy resin when the epoxy resin composite is filled with only 5 mass% eggshell particles. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
The effect of poly(vinyl alcohol) hydrolysis on the properties of its blends with nylon 6
Authors: Cui Li , Fu Qiang , Chang Chang‐jung , Yeh Jen‐taut 
Published: May 2009

AbstractAn investigation of the properties of the blends of nylon 6 (PA6) and poly(vinyl alcohol) (PVA) with varying degrees of hydrolysis was conducted. A near disappearance of the characteristics of the α‐form PVA crystals, crystallization exotherms, and hydrogen‐bonded hydroxyl groups and the tensile properties originally associated with the PVA molecules of PA6xPVA PA6xPVA, and PA6xPVA specimens was observed as the PVA contents of the specimens became equal to or less than their corresponding ‘‘critical’’ values at 16.7 wt%, 33.3 wt%, and 50 wt%, respectively. These results support the idea that PVA molecules are miscible with PA6 molecules to some extent at the molecular level as the PVA contents of the blends become equal to or less than their corresponding critical PVA contents. In this article, we have proposed the possible reasons accounting for these properties of the PA6xPVAy series specimens with a varying degree of hydrolysis. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Steady‐state viscoelastic flow simulation of polymer melts in a rotational‐type rheometer
Authors: Tanoue Shuichi , Zielinski Michal K. , Iemoto Yoshiyuki 
Published: May 2009

AbstractPolymer samples in the jigs begins to protrude when the heat is turned up when we measure the rheological characteristics of polymer melts using rotational‐type rheometers, such as parallel and cone‐and‐plate types. To clarify the effects of this protruding part on the obtained rheological data, we tried to evaluate the rotational‐type rheometer by a non‐isothermal viscoelastic flow simulation using the finite element method. The multiple mode Phan‐Thien Tanner (PTT) model was employed as the constitutive equation. As a result, the shear viscosity in the steady state increases with the size of the protruding part of the polymer melt specimen at the same shear rate in case with a parallel plate and a cone‐and‐plate type rheomters. In contrast, the deviation of the primary normal stress difference between the estimated value from the simulation results and the data from the PTT model is almost independent of the size of the protruding part with the cone‐and‐plate type rheometer. In addition, the deviations of the primary normal stress difference with a parallel plate rheometer increase with the protruding part size. However, these deviations are smaller than those of shear viscosity. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Enhancing thermal, electrical efficiencies of a miniature combustion‐driven thermophotovoltaic system
Authors: Li Yueh‐Heng , Li Hong‐Yuan , Dunn‐Rankin Derek , Chao Yei‐Chin 
Published: May 2009

AbstractMethods to enhance the thermal and electrical efficiencies through novel design of combustion and thermal management of the combustor in a miniature thermophotovoltaic (TPV) system are proposed, discussed, and demonstrated in this paper. The miniature TPV system consists of a swirling combustor surrounded by GaSb PV cell arrays. The swirl combustor design, along with a heat‐regeneration reverse tube and mixing‐enhancing porous‐medium fuel injection, improves the low illumination and incomplete combustion problems associated with typical miniature TPV systems. A reverse tube is used to enforce swirling flame attachment to the inner wall of the emitter by pushing the swirl recirculation zone back into the chamber and simultaneously redirecting the hot product gas for reheating the outer surface of the emitter. The porous medium fuel injector is used as a fuel/air mixing enhancer and as a flame stabilizer to anchor the flame. The miniature TPV system, using different combustor configurations, is tested and discussed. Results indicate that the proposed swirling combustor with a reverse tube and porous medium can improve the intensity and uniformity of the emitter illumination, and can increase the thermal radiant efficiency. Consequently, the overall thermal efficiency and electrical output of the miniature TPV system are greatly enhanced. Copyright © 2009 John Wiley & Sons, Ltd.
Preventive screening for early readers: Predictive validity of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS)
Authors: Goffreda Catherine T. , Diperna James Clyde , Pedersen Jason A. 
Published: May 2009

AbstractCurrent empirical evidence indicates poor learning trajectories for students with early literacy skill deficits. As such, reliable and valid detection of at‐risk students through regular screening and progress monitoring is imperative. This study investigated the predictive validity of scores on the Dynamic Indicators of Basic Early Literacy Skills (DIBELS). Logistic regression analyses were used to test the utility of the DIBELS first grade indicators for predicting reading proficiency on TerraNova California Achievement Test (CAT) Assessment and Pennsylvania System of School Assessment (PSSA) in second and third grade, respectively. Results suggest that students' first grade Oral Reading Fluency (ORF) DIBELS risk category scores were the only significant predictor of future TerraNova and PSSA reading proficiency. Although the current data present encouraging results for the predictive validity of ORF as a screening tool for early readers, further investigations of the utility of the remaining indicators (Letter Naming Fluency, Nonsense Word Fluency, and Phonemic Segmentation Fluency) are warranted. © 2009 Wiley Periodicals, Inc.
Green polymer chemistry using nature's catalysts, enzymes
Authors: Puskas Judit E. , Sen Mustafa Y. , Seo Kwang Su 
Published: May 2009

AbstractThe use of enzymes as catalysts for organic synthesis has become an increasingly attractive alternative to conventional chemical catalysis. Enzymes offer several advantages including high selectivity, ability to operate under mild conditions, catalyst recyclability, and biocompatibility. Although there are many examples in the literature involving enzymes for the synthesis of polymers, our search showed that very little had been done in the area of polymer modification. In this article, we will discuss enzyme catalysis in general and highlight our recent results concerning precision polymer functionalization using enzymatic catalysis—“green polymer chemistry.” © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2959–2976, 2009
Solvent‐induced self‐assembly in cardanol‐based urethane methacrylate comb polymers
Authors: Rekha N. , Asha S. K. 
Published: May 2009

AbstractWe report side chain urethane–methacrylate comb polymers based on the renewable resource cardanol and its saturated analogue 3‐pentadecyl phenol and their self‐assembly into pores, spheres, vesicles, tubes, and so forth. The monomers were synthesized in one pot by coupling 1 equiv. of isophorone diisocyanate with 1 equiv. of cardanol/pentadecyl phenol followed by coupling with 1 equiv. of hydroxyethyl methacrylate. They were polymerized free radically using benzoyl peroxide as the initiator and were characterized by NMR and FTIR, and their molecular weights were determined by gel permeation chromatography. The unique polymer design had sites for self‐organization via hydrogen bonding of the side chain urethane units, π–π stacking interactions of the aromatic units as well as interdigitation of the long C15 alkyl side chains in the polymer. The morphologies of solvent cast polymer films were studied using microscopic techniques such as scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The polymers exhibited three‐dimensional honeycomb morphology in CHCl3, whereas in tetrahydrofuran, they formed spheres. The direct cardanol‐derived polymer PCIH showed a tendency for multiple morphologies such as spheres and tubes in tetrahydrofuran. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2996–3009, 2009