bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional expression of the chemokine receptor XCR1 on oral epithelial cells
Authors: Khurram Syed A , Whawell Simon A , Bingle Lynne , Murdoch Craig , McCabe Brenka M , Farthing Paula M 
Published: February 2010

AbstractChemokines are chemoattractant cytokines which act on specific receptors and play an important role in leukocyte migration as well as physiological and pathological processes. We investigated the role of the chemokine receptor XCR1 and its ligand lymphotactin (Lptn/XCL1) in the regulation of oral epithelial cell behaviour. In vitro XCR1 mRNA and cell surface protein expression was detected in normal oral keratinocytes and oral squamous cell carcinoma cell lines. Lymphotactin mediated intracellular activation of the ERK1/2 signalling pathway and stimulated migration, invasion, and proliferation of all cells through XCR1. Oral cancer cells showed a greater response to lymphotactin than normal keratinocytes and a direct relationship between receptor expression and migration, invasion, and proliferation was observed. Exposure of normal keratinocytes to lymphotactin resulted in increased adhesion to fibronectin but not collagen and stimulated MMP‐2 and MMP‐9 but not MMP‐7 release, whereas exposure of cancer cells resulted in increased adhesion to both collagen and fibronectin and stimulated production of MMP‐2, MMP‐9, and MMP‐7. We observed XCR1 but not lymphotactin to be expressed by epithelial cells in normal oral mucosa in vivo, whilst both were expressed and up‐regulated in inflammatory oral disease and oral cancer including primary and metastatic disease. Lymphotactin mRNA and constitutive intracellular protein were detected in normal keratinocytes and oral cancer cell lines in vitro. These findings show that XCR1 and its ligand, lymphotactin, are expressed by oral epithelial cells and suggest that they play a role in regulating the behaviour of these cells. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Validation of ischemic cerebrovascular diagnoses in the health improvement network (THIN)
Authors: Ruigómez Ana , Martín‐Merino Elisa , Rodríguez Luis Alberto García 
Published: February 2010

AbstractPurposeTo evaluate the validity of recorded diagnoses of ischemic cerebrovascular events requiring hospitalization within The Health Improvement Network (THIN) UK primary care database.MethodsWe identified 15 397 individuals aged 40–84 years with a first recorded ischemic event in 2000–2004. Of these, 4239 had a code suggestive of a hospitalization within 2 weeks of the event. A three‐step strategy was used to validate the records of these patients: manual review of computerized medical records excluding free‐text comments; manual review including free‐text comments (which include information gained from specialists, hospital discharge letters and results of diagnostic tests) of a random sample of possible cases (n = 300) and non‐cases (n = 100); and review of full medical records of this random sample and a questionnaire completed by their primary care physician. The positive predictive value (PPV) of each step was calculated. The confirmation rate was used to estimate incidence in the general population.ResultsAfter step 1, 3447 individuals were classified as possible cases and 792 were excluded as non‐cases. After step 2, 82% of possible cases were still classified as such. Step 3 showed that inclusion of free‐text comments increased the PPV of a diagnosis from 76 to 86%. The weighted incidence of hospitalized ischemic cerebrovascular events was 1.73 per 1000 person‐years (95% CI:1.68–1.77).ConclusionsTHIN demonstrates a high validity for the study of ischemic cerebrovascular events when reviewing computer records with additional free‐text comments. Accuracy of hospitalization status was not as well recorded. Copyright © 2010 John Wiley & Sons, Ltd.
Electromechanical stability of a Mooney–Rivlin‐type dielectric elastomer with nonlinear variable permittivity
Authors: Liu Yanju , Liu Liwu , Sun Shouhua , Leng Jinsong 
Published: February 2010

AbstractThe electromechanical stability of a Mooney–Rivlin‐type dielectric elastomer undergoing large deformation with nonlinear permittivity is investigated. The stability is analyzed by applying a new kind of free energy model, which couples Ogden elastic strain energy and electric field energy density with nonlinear permittivity. Then, nominal electric field and nominal electric displacement of the dielectric elastomer are introduced. Based on this, the electromechanical stability of the Mooney–Rivlin‐type dielectric elastomer is analyzed by simplifying the Ogden elastic strain energy. The critical breakdown electric fields under the conditions of two stretching ratios and various material constant ratios k (n = km, where m and n are material constants in the Ogden model, determined experimentally) are also obtained. According to the simulation results, for a larger dimensionless constant k of the dielectric material, the critical nominal electric field is higher, the corresponding dielectric elastomer or structure is more stable and the electromechanical stability of the dielectric elastomer is proved to be markedly enhanced by a pre‐stretching process. These results agree well with experimental data and can be used as guidance in the design and fabrication of dielectric elastomer actuators. Copyright © 2010 Society of Chemical Industry
MS characterization of qualitative protein polymorphisms in the spinal cords of inbred mouse strains
Authors: Mikkat Stefan , Lorenz Peter , Scharf Christian , Yu Xinhua , Glocker Michael O. , Ibrahim Saleh M. 
Published: February 2010

AbstractThe spinal cord proteomes of two inbred mouse strains with different susceptibility to experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, were investigated by 2‐DE and MALDI‐MS. A proteome map comprising 304 different protein species was established. Using 2‐D fluorescence difference gel electrophoresis, a comparison of the mouse strains revealed 26 qualitatively polymorphic proteins with altered electrophoretic mobility. MS analyses and DNA sequencing were applied to characterize their structural differences and 14 single amino acid substitutions were identified. Moreover, analysis of selectively enriched phosphopeptides from the neurofilament heavy polypeptide of both mouse strains revealed a high degree of diversity in the phosphorylated C‐terminal domains of this protein. The described approach is capable to structurally characterize qualitative protein polymorphisms, whereas their functional significance remains to be elucidated. For some proteins formerly associated with experimental autoimmune encephalomyelitis and/or multiple sclerosis structural polymorphisms are described here, which may be subjected to further investigations. In addition, this work should be of general interest for proteomic analysis of inbred strains, because it shows potentials and constraints in the use of 2‐DE analysis and MALDI‐MS to detect and characterize structural protein polymorphisms.
Gas‐phase basicities of acetophenones toward lanthanum cation [La(OMe)]
Authors: Than Soe , Badal Md. Mizanur Rahman , Itoh Shuhei , Mishima Masaaki 
Published: February 2010

AbstractThe relative free energy changes (lanthanum cation basicity, LaCB[L2]) for the reaction [La(OMe)2]L ⇌ La(OMe) + 2L were determined in the gas phase for m‐ and p‐substituted acetophenones based on the measurement of ligand exchange equilibria using an FT‐ICR mass spectrometer. The substituent effect on ΔLaCB[L2] of acetophenone is described in terms of the Yukawa–Tsuno equation, ΔG = ρ(σ° + r+ Δ σ), with a ρ value of −11.2 and an r+ value of 0.49. From this result, a ρ value of −7.0 and an r+ value of 0.49 were estimated for the monomeric complex [LLa(OMe)] with the aid of theoretical calculations. This ρ value was found to be significantly smaller than that for protonation, and even smaller than Li+ basicity. Such a small ρ value has been attributed to the largely ionic (ion–dipole interaction) nature of the bonding interaction between La(OMe) and the carbonyl oxygen atom and, in part, to the long distance between La(OMe) and the substituent. Contrary to the ρ value, the r+ value is identical in both La(OMe) and Li+ basicities, suggesting that the r+ value of 0.49 can be regarded as a limiting one in a series of Lewis cation basicities of the acetophenone system, H+ (0.86) > Me3Si+ (0.75) > Me3Ge+ (0.71) > Cu+ (0.60) > Li+ = La(OMe) (0.49). Since the binding interaction between La(OMe) or Li+ and a neutral ligand is mostly electrostatic, the moderate r+ was interpreted to result from the redistribution of the induced positive charge within the acetophenone moiety upon binding with a metal ion rather than transfer of positive charge from a metal ion to the aromatic moiety. Copyright © 2010 John Wiley & Sons, Ltd.
How quantum tunnelling can contribute to proton transfer at biologically relevant temperatures
Authors: Horsewill A. J. 
Published: February 2010

AbstractThe double proton transfer reaction in the bridging hydrogen bonds of carboxylic acid dimers provides a model system for investigating the fundamental physics underpinning the role of quantum tunnelling in molecular dynamics. The behaviour of this system is used to discuss the possible role that tunnelling plays in the molecular dynamics that characterise more complex biological systems at high temperature. Copyright © 2010 John Wiley & Sons, Ltd.
A DFT study on the mechanisms for gas phase reaction of yttrium with propene
Authors: Li Tao Hong , Xie Xiao Guang 
Published: February 2010

AbstractThe gas phase reaction of ground‐state yttrium (Y) with propene, previously examined by crossed molecular beams (CMBs) experiment, has been theoretically investigated in detail using B3LYP method. Three concerted and five stepwise pathways were found for H2 elimination. The calculated PESs indicate that the concerted mechanisms are energetically much more favorable than the stepwise mechanisms for the elimination of H2. Three isomers, Y‐propyne, Y‐allene, and Y(CHCHCH2), were assigned to the experimentally observed H2‐elimination product, YC3H4. Three pathways were identified for the CC bond cleavage products, YCH2 + C2H4. The energetically most favorable pathway involves the formation of a metallacyclobutane intermediate, which can decay to YCH2 + C2H4. The results of this study confirmed some previous inferences and provided more details for the title reaction. Copyright © 2010 John Wiley & Sons, Ltd.
Chemically amplified photoresists for 193‐nm photolithography: Effect of molecular structure and photonic parameters on photopatterning
Authors: Ridaoui Hassan , Dirani Ali , Soppera Olivier , Ismailova Esma , Brochon Cyril , Schlatter Guy , Hadziioannou Georges , Tiron Raluca , Bandelier Philippe , Sourd Claire 
Published: February 2010

AbstractNext generations of microelectronic devices request further miniaturized systems. In this context, photolithography is a key step and many efforts have been paid to develop new irradiation setup and materials compatible with sub‐100 nm resolution. Among other resist platforms, chemically amplified photoresists (CAR) are widely used because of their excellent properties in terms of resolution, sensitivity, and etching resistance. However, low information on the impact of the polymer structure on the lithography performance is available. CAR with well‐controlled polymer structures were thus prepared and investigated. In particular, the impact of the polymer structure on the lithographic performance was evaluated. Linear and branched polymers with various molecular weights and polydispersities were compared. We focused on the dependency of the photosensitivity of the resist with the structural parameters. These results allow further understanding the fundamental phenomena involved by 193‐nm irradiation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1271–1277, 2010
Sol‐gel transition behavior of amphiphilic comb‐like poly[(PEG‐b‐PLGA)acrylate] block copolymers
Authors: Park Chung Won , Kim Sung Chul 
Published: February 2010

AbstractThe effects of comb‐like amphiphilic block copolymer architectures on the physical properties such as sol‐gel transition and micellization behaviors with the change of temperature and pH were examined. Comb‐like poly((poly(ethylene glycol)‐b‐(poly(lactic acid‐co‐glycolic acid))acrylate‐co‐acrylic acid) (poly((PEG‐b‐PLGA)A‐co‐AA)) copolymers were synthesized by coupling of poly(acrylic acid) (PAA) with two different kinds of PEG‐b‐PLGA diblock copolymers to investigate the effects of the number of branches and hydrophilicity/hydrophobicity on the sol‐gel transition and micellization. The molecular weights and chemical structures were confirmed by GPC and 1H NMR. The number of PEG‐b‐PLGA branches was gradually deviated from the feed molar ratio with increasing the molecular weight and the number of branches and due to the bulkiness of PEG‐b‐PLGA. Poly[(PEG‐b‐PLGA)A‐co‐AA] aqueous solutions showed thermosensitive sol‐gel transition behavior, and the gelation took place at lower concentration with increasing the number of branches and PLGA chain length due to the increase of hydrophobicity. The temperature, at which abrupt increase of viscosity by dynamic rheometer appeared, was also in good agreement with sol‐gel transition by tube‐titling method. The CMC, calculated from UV‐Visible spectroscopy using DPH as hydrophobic dye, also decreased with increasing the number of PEG‐b‐PLGA branches and PLGA chain length with same reason. The micelle size was increased with increasing temperature at the initial stage, however, decreased with further increase of temperature, since the micelles were, first, aggregated by hydrophobic intermolecular interaction, and then fragmented by dehydration of PEG segments with increasing temperature. PH‐sensitive PAA backbone played a key role in physical properties. With decreasing pH, sol‐to‐gel transition temperature, CMC values, and micelle size were decreased because of the increase of hydrophobicity resulting form non‐ionized acrylic acid. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1287–1297, 2010
Triphenylamine‐based fluorescent conjugated copolymers with pendant terpyridyl ligands as chemosensors for metal ions
Authors: Cui Yi , Chen Qi , Zhang Dan‐Dan , Cao Jie , Han Bao‐Hang 
Published: February 2010

AbstractTwo well‐defined triphenylamine‐based fluorescent conjugated copolymers with pendant terpyridyl ligands were synthesized through Suzuki coupling polymerization and were further characterized by 1H‐NMR, 13C‐NMR, gel permeation chromatography, Infrared, and UV‐vis spectra. Polymer P‐1, terpyridine‐bearing poly(triphenylamine‐alt‐fluorene) with a high fluorescence quantum yield (62%) shows much higher sensitivities toward Fe3+, Ni2+, and Cu2+ as compared with the other metal ions investigated. Especially, Fe3+ can lead to an almost complete fluorescence quenching of polymer P‐1. Whereas, the analogous polymer P‐2, in which N‐ethylcarbazole repeat units replace the fluorene units in P‐1, shows a very poor selectivity. It demonstrates that polymers with a same receptor may show different sensitivity to analytes owing to their different type of backbones. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1310–1316, 2010
A facile method for the preparation of monodisperse hollow silica spheres with controlled shell thickness
Authors: Cao Shunsheng , Jin Xin , Yuan Xinhua , Wu Weiwei , Hu Jie , Sheng Weichen 
Published: February 2010

AbstractThis article presents a facile, effective, mild synthesis process for well‐defined hollow spheres by using cationic polystyrene (PS) submicro‐particles as templates. In this approach, the cationic PS templates can be first prepared via emulsifier‐free polymerization by using the cationic monomer 2‐(methacryloyloxy) ethyltrimethylammonium chloride as comonomer, then, the silica shells from the sol‐gel process of tetraethoxysilane were coated on the surfaces of template particles via electrostatic interaction, finally the PS was dissolved in situ by modification of the reaction conditions in the same medium to form monodisperse hollow silica spheres with controlled shell thickness. Fourier transform‐infrared spectroscopy, thermogravimetric analysis, Brunauer‐Emmett‐Teller, transmission electron microscopy, and scanning electron microscope measurements were used to characterize these hollow silica spheres. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1332–1338, 2010
Chemical synthesis and characterization of poly(aniline‐co‐ethyl 3‐aminobenzoate) copolymers
Authors: Gizdavic‐Nikolaidis Marija R. , Zujovic Zoran D. , Ray Sudip , Easteal Allan J. , Bowmaker Graham A. 
Published: February 2010

AbstractCopolymers of aniline and ethyl 3‐aminobenzoate (3EAB) were synthesized by chemical polymerization in several mole ratios of aniline to functionalized aniline, and their physicochemical properties were compared to those of poly(aniline‐co‐3‐aminobenzoic acid) (3ABAPANI) copolymers. The copolymers were characterized with UV–vis, FTIR, Raman, SEM, EPR, and solid‐state NMR spectroscopy, elemental analysis, and conductivity measurements. The influence of the carboxylic acid and ester group ring substituents on the copolymers was investigated. The spectroscopic studies confirmed incorporation of 3ABA or 3EAB units in the copolymers and hence the presence of CO group in the copolymer chains. The conductivity and EPR signals both decreased with increasing 3EAB content of the copolymers emeraldine salt (ES) form. The conductivity of the ES form of 3ABAPANI was found to be high (1.4 × 10−1 S cm−1) compared with the conductivity (10−2–10−3 S cm−1) of 3EABPANI (ES) copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1339–1347, 2010
Room‐temperature RAFT copolymerization of 2‐chloroallyl azide with methyl acrylate and versatile applications of the azide copolymers
Authors: Li Guang , Wang Hu , Zheng Haiting , Bai Ruke 
Published: February 2010

AbstractA new vinyl azide monomer, 2‐chlorallyl azide (CAA), has been synthesized from commercially available reagent in one step. The reversible addition fragmentation chain transfer (RAFT) copolymerization of CAA with methyl acrylate (MA) was carried out at room temperature using a redox initiator, benzoyl peroxide (BPO)/N,N‐dimethylaniline (DMA), in the presence of benzyl 1H‐imidazole‐1‐carbodithioate (BICDT). The polymerization results showed that the process bears the characteristics of controlled/living radical polymerizations, such as the molecular weight increasing linearly with the monomer conversion, the molecular weight distribution being narrow, and a linear relationship existing between ln([M]0/[M]) and the polymerization time. Chain extension polymerization was performed successfully to prepare block copolymer. Furthermore, the azide copolymers were functionalized by CuI‐catalyzed “click” reaction with alkyne‐containing poly(ethylene glycol) (PEG) to yield graft copolymers with hydrophilic PEG side chains. Surface modification of the glass sheet was successfully achieved via the crosslinking reaction of the azide copolymer under UV irradiation at ambient temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1348–1356, 2010
Chain‐growth condensation polymerization of 4‐aminobenzoic acid esters bearing tri(ethylene glycol) side chain with lithium amide base
Authors: Yoshino Kazuo , Hachiman Kotaro , Yokoyama Akihiro , Yokozawa Tsutomu 
Published: February 2010

AbstractChain‐growth condensation polymerization of p‐aminobenzoic acid esters 1 bearing a tri(ethylene glycol) monomethyl ether side chain on the nitrogen atom was investigated by using lithium 1,1,1,3,3,3‐hexamethyldisilazide (LiHMDS) as a base. The methyl ester monomer 1a afforded polymer with low molecular weight and a broad molecular weight distribution, whereas the polymerization of the phenyl ester monomer 1b at −20 °C yielded polymer with controlled molecular weight (Mn = 2800–13,400) and low polydispersity (Mw/Mn = 1.10–1.15). Block copolymerization of 1b and 4‐(octylamino)benzoic acid methyl ester (2) was further investigated. We found that block copolymer of poly1b and poly2 with defined molecular weight and low polydispersity was obtained when the polymerization of 1b was initiated with equimolar LiHMDS at −20 °C and continued at −50 °C, followed by addition of 2 and equimolar LiHMDS at −10 °C. Spherical aggregates were formed when a solution of poly1b in THF was dropped on a glass plate and dried at room temperature, although the block copolymer of poly1b and poly2 did not afford similar aggregates under the same conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1357–1363, 2010
ATRP of methyl methacrylate initiated with a bifunctional initiator bearing bromomethyl functional groups: Synthesis of the block and graft copolymers
Authors: Ozturk Temel , Yilmaz Sevil Savaskan , Hazer Baki , Menceloglu Yusuf Z. 
Published: February 2010

AbstractThis article reports the synthesis of the block and graft copolymers using peroxygen‐containing poly(methyl methacrylate) (poly‐MMA) as a macroinitiator that was prepared from the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in the presence of bis(4,4′‐bromomethyl benzoyl peroxide) (BBP). The effects of reaction temperatures on the ATRP system were studied in detail. Kinetic studies were carried out to investigate controlled ATRP for BBP/CuBr/bpy initiating system with MMA at 40 °C and free radical polymerization of styrene (S) at 80 °C. The plots of ln ([Mo]/[Mt]) versus reaction time are linear, corresponding to first‐order kinetics. Poly‐MMA initiators were used in the bulk polymerization of S to obtain poly (MMA‐b‐S) block copolymers. Poly‐MMA initiators containing undecomposed peroygen groups were used for the graft copolymerization of polybutadiene (PBd) and natural rubber (RSS‐3) to obtain crosslinked poly (MMA‐g‐PBd) and poly(MMA‐g‐RSS‐3) graft copolymers. Swelling ratio values (qv) of the graft copolymers in CHCl3 were calculated. The characterizations of the polymers were achieved by Fourier‐transform infrared spectroscopy (FTIR), 1H‐nuclear magnetic resonance (1H NMR), gel‐permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and the fractional precipitation (γ) techniques. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1364–1373, 2010
Phosphido‐diphosphine pincer group 3 complexes as efficient initiators for lactide polymerization
Authors: Mazzeo Mina , Lamberti Marina , D'Auria Ilaria , Milione Stefano , Peters Jonas C. , Pellecchia Claudio 
Published: February 2010

AbstractNew Group 3 metal complexes of the type [LM(CH2SiMe3)2(THF)n] supported by tridentate phosphido‐diphosphine ligands [(o‐C6H4PR2)2PH; L1‐H: R = iPr; L2‐H: R = Ph] have been synthesized by reaction of L1‐H and L2‐H with [M(CH2SiMe3)3(THF)2)] (M = Y and Sc). All the new complexes [(o‐C6H4PR2)2PM(CH2SiMe3)2(THF)n] [M = Y, R = iPr (1), R = Ph (2); M = Sc, R = iPr (3), R = Ph (4)] were studied as initiators for the ring opening polymerization of lactide. The yttrium complexes (1 and 2) exhibited high activity and good polymerization control, shown by the linear fits in the plot of number‐averaged molecular weight (Mn) versus the percentage conversion and versus the monomer/initiator ratio and by the low polydispersity index values. Interestingly, very good molar‐mass control was observed even when L‐Lactide was polymerized in the absence of solvent at 130 °C. A good molar‐mass control but lower activities were observed in the polymerization reaction of lactide promoted by the analogous scandium complexes 3 and 4. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1374–1382, 2010