bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Strategy to Incorporate Carbon Nanotubes into Thermoplastic Matrices
Authors: Pötschke Petra , Pegel Sven , Claes Michael , Bonduel Daniel 
Published: December 2007

AbstractMultiwalled carbon nanotubes (MWNT) are introduced into thermoplastic matrices (polycarbonate and polyamide) by melt blending using polyethylene (PE) based concentrates with high MWNT loadings (24–44 wt.‐%). MWNT surfaces were treated with a metallocene‐based complex to afford the in‐situ polymerization of ethylene directly from the surface. The resulting concentrates showed excellent MWNT pre‐dispersion. Due to the high interfacial energy between MWNT and PE, the nanotubes migrate into matrix polymers with lower interfacial energies, like polycarbonate and polyamide, and thereby remain in their excellent dispersion state. Thus, electrical percolation is achieved at lower MWNT contents as compared to direct incorporation. For polycarbonate it is shifted from 0.75 to 0.25 wt.‐%.magnified image
Multi‐Sensitive Microgels Filled with Conducting Poly(3,4‐ethylenedioxythiophene) Nanorods
Authors: Hain Jessica , Eckert Franziska , Pich Andrij , Adler Hans‐Juergen 
Published: December 2007

AbstractIn this work we describe the synthesis of multi‐sensitive aqueous microgel particles with incorporated conducting poly(3,4‐ethylenedioxythiophene) (PEDOT) nanorods. We demonstrate that the loaded amount of PEDOT nanorods as well as their morphology can be varied by controlling the reaction conditions such as monomer concentration and alcohol concentration in aqueous phase. Obtained microgels can be stimulated by changes in the environment temperature as well as by the repulsion/attraction forces within polymeric network due to the reversible oxidation/reduction of the conjugated polymer. Microgels with unique properties can be operated in colloidal systems or used as building blocks for the preparation of nanostructured films.magnified image
High Rate Silicification of Peptide‐Polymer Assemblies Toward Composite Nanotapes
Authors: Kessel Stefanie , Börner Hans G. 
Published: December 2007

AbstractWell‐defined silica composite nanofibers are generated in a silicification process of self‐assembled poly(ethylene oxide)‐peptide nanotapes. Inspired by biological silica morphogenesis processes the nanotapes exhibit strong binding capabilities for silicic acid. Thus, pre‐hydrolyzed tetramethoxysilane could be used as silica precursor. Very low concentrations (270 µM) and short contact times (10 s) are sufficient to form effectively integrated nano‐composite tapes.magnified image
Thermal Stability of Lyocell Solutions: Experimental Results and Modeling Using Cluster Analysis and Partial Least Squares Regression
Authors: Wendler Frank , Kolbe Axel , Kraft Jörg , Einax Jürgen W. , Heinze Thomas 
Published: December 2007

AbstractA population of 167 samples were monitored using by rheological, calorimetric, chromatographic and spectroscopic methods, which allows a precise description of the thermal behavior. Hierarchical cluster analysis was used to find similarities between groups of samples. Principal components analysis revealed isoperibolic pressure slope, morpholine and N‐methylmorpholine as variables providing most information concerning the thermostability. The onset temperature as the beginning of an exothermicity can be modeled by the combination of detection of amines and aldehydes and subsequent PLS regression.magnified image
Excessive dopamine neuron loss in progressive supranuclear palsy
Authors: Murphy Karen E. , Karaconji Tanya , Hardman Craig D. , Halliday Glenda M. 
Published: December 2007

AbstractProgressive supranuclear palsy (PSP) and Parkinson's disease (PD) differ in their response to dopaminergic replacement therapies, despite having a similar degree of neuronal degeneration in the dopaminergic substantia nigra. We observed more widespread dopamine neuron loss in the extranigral A10 midbrain cell groups in PSP compared with PD. These cell groups innervate subcortical and cortical regions and may be required for adequate response to levodopa therapy. © 2007 Movement Disorder Society
Goldsinny wrasse (Ctenolabrusrupestris) is an extreme vtgAa‐type pelagophil teleost
Authors: Kolarevic Jelena , Nerland Audun , Nilsen Frank , Finn Roderick Nigel 
Published: December 2007

AbstractDuring oocyte maturation in the goldsinny wrasse (Ctenolabrus rupestris) extensive proteolysis of yolk proteins generates a large pool of free amino acids that drive hydration of the pelagic egg. By cloning hepatic vitellogenins (vtg) and using mass spectrometry, N‐terminal microsequencing, and Western‐immunoblotting to identify the yolk proteins (Yp), we show that multiple forms of vitellogenin mRNAs (vtgAa, vtgAb, and vtgC) are expressed in the liver, but only a single major class of the Yps derived from vtgAa predominates in the oocytes. Some Yps derived from vtgAb and vtgC appear also to be incorporated in the oocytes and eggs, but only at background levels. During oocyte hydration the vtgAa‐derived lipovitellin heavy chain (LvH‐Aa) and its cleavage variants are completely degraded leaving only a processed lipovitellin light chain (LvL‐Aa) fragment as the major yolk protein for embryonic development. The maturational cleavage site of the LvL‐Aa is identified as two amino acids downstream from the conserved Tyr1168 of VtgAa in Atlantic halibut. In addition, although a β′‐component (∼18 kDa) is present in the oocytes, it is not fully degraded during the hydration process. Mol. Reprod. Dev. 75: 1011–1020, 2007. © 2007 Wiley‐Liss, Inc.
Effect of temporary nuclear arrest by Phosphodiesterase 3‐Inhibitor on morphological and functional aspects of in vitro matured mouse oocytes
Authors: Vanhoutte Leen , Nogueira Daniela , Gerris Jan , Dhont Marc , De Sutter Petra 
Published: December 2007

AbstractThe present study aimed to analyze detailed morphological and functional characteristics of mouse in vitro matured oocytes after a pre‐maturation culture (PMC) by temporary nuclear arrest with the specific phosphodiesterase 3‐inhibitor (PDE3‐I) Cilostamide. In a first experiment the lowest effective dose of Cilostamide was determined. Cumulus–oocyte complexes (COCs), isolated from small antral follicles, were exposed to different concentrations of Cilostamide (ranging from 0 (control) to10 µM) for 24 hr. Afterwards, oocytes were removed from PDE3‐I‐containing medium and underwent in vitro maturation (IVM) for 16–18 hr. A concentration of 1 µM Cilostamide was the lowest effective dose for maximum level of inhibition and reversibility of meiosis inhibition. This concentration was used in further experiments to evaluate oocyte quality following IVM in relation to different parameters: kinetics of meiotic progression, metaphase II (MII) spindle morphology, aneuploidy rate, fertilization, and embryonic developmental rates. The results were compared to nonarrested (in vitro control) and in vivo matured oocytes (in vivo control). Following withdrawal of the inhibitor, the progression of meiosis was more synchronous and accelerated in arrested when compared to nonarrested oocytes. A PMC resulted in a significant increase in the number of oocytes constituting a MII spindle of normal morphology. None of the oocytes exposed to PDE3‐I showed numerical chromosome alterations. In addition, fertilization and embryonic developmental rates were higher in the PMC group compared to in vitro controls, but lower than in vivo controls. These results provide evidence that induced nuclear arrest by PDE3‐I is a safe and reliable method to improve oocyte quality after IVM. Mol. Reprod. Dev. 75: 1021–1030, 2007. © 2007 Wiley‐Liss, Inc.
Necessary and sufficient local convergence condition of one class of iterative aggregation–disaggregation methods
Authors: Pultarová Ivana 
Published: December 2007

AbstractThis paper concludes one part of the local convergence analysis of a certain class of iterative aggregation–disaggregation methods for computing a stationary probability distribution vector of an irreducible stochastic matrix B. We show that the local convergence of the algorithm is determined only by the sparsity pattern of the matrix and by the choice of the aggregation groups. We introduce the asymptotic convergence rates of the normalized components of approximations corresponding to particular aggregation groups and we also specify an upper bound on the rates. Copyright © 2008 John Wiley & Sons, Ltd.
Health outcomes associated with potentially inappropriate medication use in older adults
Authors: Fick Donna M. , Mion Lorraine C. , Beers Mark H. , L. Waller Jennifer 
Published: December 2007

AbstractThe purpose of this study was to examine the prevalence of potentially inappropriate medication use (PIMs) among community‐dwelling older adults and the association between PIMs and health care outcomes. Participants were 17,971 individuals age 65 years and older. PIM use was defined by the Beers criteria. Drug‐related problems (DRPs) were defined using ICD‐9 codes. Forty percent of the 17,971 individuals filled at least 1 PIM prescription, and 13% filled 2 or more PIM prescriptions. Overall DRP prevalence among those with at least 1 PIM prescription was 14.3% compared to 4.7% in the non‐PIM group (p < .001). In conclusion, preventing PIM use may be important for decreasing medication‐related problems, which are increasingly being recognized as requiring an integrated interdisciplinary approach. © 2007 Wiley Periodicals, Inc. Res Nurs Health 31:42–51, 2008
Examining pain‐related distress in relation to pain intensity and psychological distress
Authors: Wells Nancy , Ridner Sheila H. 
Published: December 2007

AbstractDespite frequent use of the term symptom distress in the pain literature, symptom distress is often confused with symptom intensity and psychological distress, contributing to inadequate assessment of symptoms and less than ideal symptom management. In this article we address these issues and propose a hybrid model, combining Price's interaction of pain sensation, pain unpleasantness, and secondary pain affect model with an information processing model. Recommendations on methods and techniques to reduce this confusion would assist healthcare professionals and researchers to better distinguish among these terms as they manage patient symptoms and design symptom management studies. Thus, the purpose of this article is to examine the terms symptom distress, symptom intensity, and psychological distress using pain as the example symptom. © 2007 Wiley Periodicals, Inc. Res Nurs Health 31:52–62, 2008
The incorporation of rigid diol monomers into poly(butylene terephthalate) via solid‐state copolymerization and melt copolymerization
Authors: Jansen M. A. G. , Wu L. H. , Goossens J. G. P. , Wit G. de , Bailly C. , Koning C. E. , Portale G. 
Published: December 2007

AbstractIncorporation of 2,2‐bis[4‐(2‐hydroxyethoxy)phenyl]propane (Dianol 220®) into poly(butylene terephthalate) (PBT) via solid‐state copolymerization (SSP) showed that Dianol, besides being the reactant, also acts as a swelling agent for rigid amorphous PBT chain segments. Being swollen, these amorphous chain segments become sufficiently mobile to contribute to the SSP process. The thermal behavior of the resulting copolyesters is comparable with melt copolymerized copolymers, although having a different chemical microstructure. The main reason is a full miscibility in the melt of unmodified PBT chain segments and modified chain segments, which eliminates the advantages of a blocky microstructure for the SSP copolyesters. However, incorporation of 2,2′‐biphenyldimethanol (BDM) into PBT resulted in a higher crystallization temperature compared with PBT–Dianol copolymers of equal composition. Preordering of polymer chains in the melt by incorporating rigid, phase separating BDM‐moieties, preferably via SSP to obtain a non‐random distribution, may be the origin of the enhanced crystallization temperature. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1203–1217, 2008
ABCD 4‐miktoarm star quarterpolymers using click [3 + 2] reaction strategy
Authors: Altintas Ozcan , Hizal Gurkan , Tunca Umit 
Published: December 2007

AbstractTwo samples of ABCD 4‐miktoarm star quarterpolymer with A = polystyrene (PS), B = poly(ε‐caprolactone) (PCL), C = poly(methyl methacrylate) (PMMA) or poly(tert‐butyl acrylate) (PtBA), and D = poly(ethylene glycol) (PEG) were prepared using click reaction strategy (Cu(I)‐catalyzed Huisgen [3 + 2] reaction). Thus, first, predefined block copolymers of different polymerization routes, PS‐b‐PCL with azide and PMMA‐b‐PEG and PtBA‐b‐PEG copolymers with alkyne functionality, were synthesized and then these blocks were combined together in the presence of Cu(I)/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as a catalyst in DMF at room temperature to give the target 4‐miktoarm star quarterpolymers. The obtained miktoarm star quarter polymers were characterized by GPC, NMR, and DSC measurements. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1218–1228, 2008
New poly(ether‐ester) thermosets obtained by cationic curing of DGEBA and 7,7‐dimethyl‐6,8‐dioxaspiro[3.5] nonane‐5,9‐dione with several Lewis acids as initiators
Authors: González Lidia , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels 
Published: December 2007

AbstractScandium, ytterbium, and lanthanum triflates and boron trifluoride monoethylamine were used as cationic initiators to cure a mixture 2:1 (mol/mol) of diglycidylether of bisphenol A (DGEBA) and 7,7‐dimethyl‐6,8‐dioxaspiro[3.5]nonane‐5,9‐dione (MCB). The evolution of the epoxy and lactone during curing and the linear ester groups in the final materials were evaluated by Fourier Transform Infrared in the attenuated‐total‐reflection mode. The kinetic parameters of the curing process were calculated from DSC analysis applying isoconversional procedures. The shrinkage on curing and the thermal degradability of the materials on varying the initiator used were evaluated. The expandable character of MCB was confirmed. The materials obtained were more degradable than conventional epoxy resins due to the tertiary ester groups incorporated in the network by copolymerization. © 2008 Wiley Periodicals, Inc J Polym Sci Part A: Polym Chem 46: 1229–1239, 2008
Preparation of single‐walled carbon nanotubes‐induced poly(p‐oxybenzoyl) crystals
Authors: Kobashi Kazufumi , Lomeda Jay , Chen Zheyi , Azad Samina , Hwang Wen‐Fang , Tour James M. 
Published: December 2007

AbstractCrystallization of oligomers was applied for the preparation of single‐walled carbon nanotubes (SWNTs)/poly(p‐oxybenzoyl) (POB) crystals using SWNTs as a nucleating agent. Polymerization conditions were investigated to induce the crystallization of POB oligomers through SWNTs. SWNTs/POB plate‐like or lozenge‐shaped crystals were successfully prepared by direct polymerization of p‐hydroxybenzoic acid (HBA) in a mixed solvent of DMF/Py with TsCl in the presence of functionalized SWNTs. The size of the plate‐like crystals were ∼200 nm to 3 μm. The crystals consisted of some layers, ∼3 nm thick plates. Model reactions showed that esterification reactions proceed between functionalized SWNTs and HBA monomers in the polymerization system. The obtained crystals exhibited unique morphology and high crystallinity, producing a novel SWNT/POB hybrid. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1265–1277, 2008
Random and AB diblock copolymers of tricyclodecanemethanol urethane methacrylate with styrene: Synthesis and morphology characterization
Authors: Deepak V. D. , Asha S. K. 
Published: December 2007

AbstractA monomer design having a bulky terminal tricyclodecane (TCD) unit linked via hydrogen bondable urethane to an ethyleneoxy methacrylate unit, and capable of generating three‐dimensional honeycomb patterns upon solvent casting has been investigated. Random copolymers as well as a diblock copolymer Poly(Sty42‐b‐TCD18) of this monomer with styrene were prepared by free‐radical polymerization route and atom transfer radical polymerization (ATRP) route. Morphology characterization was carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Particle size was measured by dynamic light scattering measurements (DLS). Irrespective of the wide differences in molecular weight and polydispersity index values, the random copolymers having TCD content >30 mol % were found to form microporous films upon solvent casting from a THF/water 9:1 solvent combination. The amount of TCD in the copolymer was found to have an influence on the pore size formed. The diblock copolymer formed microspheres ∼200 nm in diameter. The thermal properties of all the polymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and the copolymers were found to have good thermal stability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1278–1288, 2008
Photoinitiated dispersion polymerization of methyl methacrylate: A quick approach to prepare polymer microspheres with narrow size distribution
Authors: Chen Jia , Zeng Zhaohua , Yang Jianwen , Chen Yonglie 
Published: December 2007

AbstractPhotoinitiated dispersion polymerization of methyl methacrylate was carried out in a mixture of ethanol and water as dispersion medium in the presence of poly(N‐vinylpyrrolidone) (PVP) as the steric stabilizer and Darocur 1173 as photoinitiator. 93.7% of conversion was achieved within 30 min of UV irradiation at room temperature, and microspheres with 0.94 μm number–average diameter and 1.04 polydispersity index (PDI) were obtained. X‐ray photoelectron spectroscope (XPS) analysis revealed that only parts of surface of the microspheres were covered by PVP. The particle size decreased from 2.34 to 0.98 μm as the concentration of PVP stabilizer increased from 2 to 15%. Extra stabilizer (higher than 15%) has no effect on the particle size and distribution. Increasing medium polarity or decreasing monomer and photoinitiator concentration resulted in a decrease in the particle size. Solvency of reaction medium toward stabilizer, which affects the adsorption of stabilizer on the particle surface, was shown to be crucial for controlling particle size and uniformity because of the high reaction rate in photoinitiated dispersion polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1329–1338, 2008
Highly absorbing superabsorbent polymer
Authors: Mudiyanselage Thilini K. , Neckers Douglas C. 
Published: December 2007

AbstractAcrylic acid (AA)–acrylamide (AM) based superabsorbent polymers (SAP) were synthesized by inverse suspension polymerization using potassium‐persulfate as the initiator, N,N′‐methylene bisacrylamide (BIS) as a crosslinker, sorbitan monostearate (Span 60) as the dispersant, cyclohexane as the solvent, and bis(methacryloylamino)‐azobenzene as the hydrophobic surface crosslinker. The influence of the polymerization parameters on the properties of the SAPs, water absorption (Q), morphology of the SAPs, swelling kinetics, salt resistance, and the reversibility of water absorption were investigated. The prepared SAPs have excellent water absorption, rapid water uptake, and good resistance to NaCl solutions. Furthermore, they show better reversible water uptake than the previously reported SAPs. The average water absorbency is 2800 g/g and 181 g/g of liquid absorbance in 0.025M NaCl solution. The initial water uptake rate is 1357 g/g/min and the reversibility of water absorption is 200 g/g in the repeated fourth cycle. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1357–1364, 2008
Dispersion polymerization of MMA in supercritical CO2 stabilized by random copolymers of 1H,1H–perfluorooctyl methacrylate and 2‐(dimethylaminoethyl methacrylate)
Authors: Hwang Ha Soo , Yuvaraj Haldorai , Kim Won Soo , Lee Won‐Ki , Gal Yeong‐Soon , Lim Kwon Taek 
Published: December 2007

AbstractA series of random copolymers, composed of 1H,1H‐perfluorooctyl methacrylate (FOMA) and 2‐dimethylaminoethyl methacrylate (DMAEMA) were prepared as stabilizers for the dispersion polymerization of methyl methacrylate in supercritical CO2 (scCO2). Free‐flowing, spherical poly(methyl methacrylate) (PMMA) particles were produced in high yield by the effective stabilization of poly(FOMA‐co‐DMAEMA) containing 34–67 w/w % (15–41 m/m %) FOMA structural units. Less stabilized but micron‐sized discrete particles could be obtained even with 25 w/w % (10 m/m %) FOMA stabilizer. The result showed that the composition of copolymeric stabilizers had a dramatic effect on the size and morphology of PMMA. The particle size was controllable with the surfactant concentration. The effect of the monomer concentration and the initial pressure on the polymerization was also investigated. The dry polymer powder obtained from dispersion polymerization could be redispersed to form stable aqueous latexes in an acidic buffered solution (pH = 2.1) by an electrostatic stabilization mechanism due to the ionization of DMAEMA units in the stabilizer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1365–1375, 2008
Atom transfer radical polymerization of methyl methacrylate catalyzed by ion exchange resin immobilized Co(II) hybrid catalyst
Authors: Huang Zhong Xi , Zhang Yong Ming , Li Hong , Luan Ying Hao , Liu Yan Gang 
Published: December 2007

AbstractIon exchange resin immobilized Co(II) catalyst with a small amount of soluble CuCl2/Me6TREN catalyst was successfully applied to atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in DMF. Using this catalyst, a high conversion of MMA (>90%) was achieved. And poly(methyl methacrylate) (PMMA) with predicted molecular weight and narrow molecular weight distribution (Mw/Mn = 1.09–1.42) was obtained. The immobilized catalyst can be easily separated from the polymerization system by simple centrifugation after polymerization, resulting in the concentration of transition metal residues in polymer product was as low as 10 ppm. Both main catalytic activity and good controllability over the polymerization were retained by the recycled catalyst without any regeneration process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1416–1426, 2008
Novel silver/polyurethane nanocomposite by in situ reduction: Effects of the silver nanoparticles on phase and viscoelastic behavior
Authors: Cocca M. , D'Orazio L. 
Published: December 2007

AbstractA novel silver/poly(carbonate urethane) nanocomposite was prepared through in situ reduction of a silver salt (AgNO3) added to a solution consisting of a commercial poly(carbonate urethane) dissolved in N,N‐dimethylformamide (DMF). In this system, the presence of the poly(carbonate urethane) was proved to protect the silver nanoparticles, whose formation was confirmed by means of UV–vis spectroscopy, from aggregation phenomena. The silver morphology developed in the solid state after DMF casting was imaged by FESEM. Homogeneous dispersion of silver nanoprisms in the poly(carbonate urethane) matrix was clearly observed. The effects of dispersion of silver nanoparticles within the poly(carbonate urethane) matrix were investigated by means of ATR‐FTIR and multifrequency dynamic mechanical thermal analyses. The obtained results revealed that the presence of silver nanoparticles modifies both the phase and the viscoelastic behaviors of poly(carbonate urethane). As a matter of fact, the hydrogen bond formation in the hard and soft segments was found to be hindered and the molecular motions of the soft segments were restricted, because a comparatively higher activation energy was required for the related α‐relaxation process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 344–350, 2008