bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonisothermal thermophysical evaluation of polypropylene/natural rubber based TPEs: Effect of blend ratio and dynamic vulcanization
Authors: Joseph Aju , Lüftl Sigrid , Seidler Sabine , Thomas Sabu , Joseph Kuruvilla 
Published: May 2009

AbstractOzawa macrokinetic model is applied to describe the nonisothermal melt crystallization process of polypropylene (PP), in natural rubber/polypropylene (NR/PP) thermoplastic elastomers (TPEs) as a function of blend ratio and dynamic vulcanization of the rubber phase. It was found that as cooling rate increases, the crystallization temperature Tc and half time for crystallization t1/2 get diminished. Dynamic vulcanizates show a similar trend in crystallization as that of neat PP. Crystallization rate constant and Ozawa exponent were found out for different temperatures by linear regression method using Ozawa analysis. Ozawa exponent, nO, showed variation in values when the conversion proceeded. For neat PP, the value of nO changes from 1.4 (102°C) to 3 (112°C). The nO values for NR/PP 50/50 blend were higher (e.g. 4.1 at 116°C). Crystallization rate constant KO shows a maximum at 0.5 relative crystallinity. The highest crystallization rate constants were found for NR/PP 50/50 TPEs. The activation energy for the melt crystallization was found to vary with the degree of conversion, as well as with the concentration of NR in the TPEs. Finally, attempts have been made to correlate the crystallization process with morphology of the blend. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Melting behavior, isothermal and nonisothermal crystallization kinetics of nylon 1111
Authors: Jiang Tao , Liu Minying , Fu Peng , Wang Yudong , Fang Yunli , Zhao Qingxiang 
Published: May 2009

AbstractThe isothermal and nonisothermal crystallization kinetics of nylon 1111 was extensively studied using differential scanning calorimetry (DSC). The equilibrium melting temperature of nylon 1111 was determined to be 188°C. In this article, the Avrami equation was used to describe the isothermal crystallization behavior of nylon 1111. On the basis of the DSC results, the Avrami exponent, n, was determined to be around 3 during the isothermal crystallization process. Nonisothermal crystallization was analyzed using both the Avrami equation as modified by Jeziorny and an equation suggested by Mo. The larger value of the Avrami exponent, n, during the nonisothermal crystallization process indicates that the development of nucleation and crystal growth are more complicated during the nonisothermal crystallization for nylon 1111, and that the nucleation mode might simultaneously include both homogeneous and heterogeneous nucleations. The isothermal and nonisothermal crystallization activation energies of nylon 1111 were determined to be −132 kJ/mol and −121 kJ/mol using the Arrhenius equation and the Kissinger method, respectively. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
RAFT copolymerization of methacrylic acid and poly(ethylene glycol) methyl ether methacrylate in the presence of a hydrophobic chain transfer agent in organic solution and in water
Authors: Rinaldi David , Hamaide Thierry , Graillat Christian , D'Agosto Franck , Spitz Roger , Georges Sébastien , Mosquet Martin , Maitrasse Philippe 
Published: May 2009

AbstractRAFT polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA, 1100 g mol−1) was first performed using cyanoisopropyl dithiobenzoate (CPDB). The control of PEGMA homopolymerization, carried out in THF ([PEGMA] = 40 wt %) at 65 °C (reflux) using 2,2′‐Azobis(isobutyronitrile) (AIBN) as initiator, was shown by the linear increase of molar masses and the low polydispersity indices (PDI) observed with conversion and also by the determination of a high chain transfer constant (Ctr = 9.1) for CPDB in this system. Copolymerization of PEGMA with methacrylic acid (MAA) ([PEGMA]/[MAA] = 40/60) was then undertaken first in dioxane at 85 °C. High conversion (89%) was obtained in 3 h without any composition drift and with a good level of control (PDI < 1.40). When the polymerization was performed in water, a strong increase in polymerization rate was observed with almost quantitative conversion (98%) in 2 h without affecting the level of control of the final copolymers (PDI ∼ 1.30). These last results were tentatively explained by the formation of hydrophobic domains in which the polymerization occurred as in bulk. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3045–3055, 2009
Conjugated polyelectrolyte with pendant carboxylate groups: Synthesis, photophysics, and pH responses in the presence of surfactants
Authors: Zhang Tao , Fan Hongliang , Zhou Jianguang , Jin Qinhan 
Published: May 2009

AbstractThis article reports the synthesis, optical properties, and pH responses of a water‐soluble poly(phenylene ethynylene) with pendant carboxylate groups. This conjugated polyelectrolyte, PPE‐OBS, was prepared via a facile synthetic route, using 1,4‐di(ethyl 4‐oxy‐butyrate)‐2,5‐diiodo‐benzene as polymeric monomer and followed by the alkali induced saponification. PPE‐OBS absorbs strongly in the blue region and emits a moderately intense fluorescence. However, it subjects to unstable emission in neutral aqueous media, which is believed to arise because the polymer tends to become more hydrophobic via protonation and to form much heavier aggregates (clusters). Subsequent studies on the interaction and stabilization of PPE‐OBS with various surfactants indicate that its fluorescence stability can be largely improved in the presence of a small amount of surfactant. More interestingly, even at low pH, the surfactant‐stabilized polyelectrolyte with its pendant groups being COOH rather than COO− remains water‐soluble and emits efficiently, which is expected of great significance for the covalent linkage to bio‐molecules. In addition, the sensitive pH response in emission spectrum of PPE‐OBS/surfactant complex over a relatively wide range suggests surely a potential access to the fluorescent sensing of pH variation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3056–3065, 2009
Polymerization of branched thiophene monomers and optoelectronic properties of materials
Authors: Takagi Koji , Torii Chikako , Yamashita Yusuke 
Published: May 2009

AbstractBithiophene monomers (5HBTh and 5HBThO) were prepared by the Suzuki coupling reaction of 3‐thienylboronic acid with 2‐bromo‐5‐hexylthiophene and 2‐bromo‐5‐hexylthiophene‐1,1‐dioxide. The oxidation polymerization mediated by vanadium catalyst gave poly(5HBTh) and oligo(5HBThO). 5HBThO bearing thiophene‐1,1‐dioxide had an absorption maximum at longer wavelength region than 5HBTh due to the intramolecular charge transfer interaction, while peak maxima blue shifted and their difference became small after the polymerization. Terthiophene monomers (5″HTTh, 3,5″DHTTh, and 4,5″DHTTh) were subsequently prepared by the mono‐bromination of 5HBTh followed by the Suzuki coupling reaction with boronic acid derivatives. The vanadium‐catalyzed oxidation polymerization of 5″HTTh and 4,5″DHTTh afforded soluble polymers and the absorption maximum wavelengths red shifted after the polymerization in contrast to bithiophene monomers and 3,5″DHTTh. The absorption and emission spectra of poly(5″DHTTh) red shifted when compared with those of poly(4,5″DHTTh). Thus the presence and position of n‐hexyl chain influenced the monomer polymerizability and optoelectronic properties of branched polythiophenes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3034–3044, 2009
N‐(2‐benzimidazolylquinolin‐8‐yl)benzamidate half‐titanocene chlorides: Synthesis, characterization and their catalytic behavior toward ethylene polymerization
Authors: Liu Shaofeng , Yi Jianjun , Zuo Weiwei , Wang Kefeng , Wang Deligeer , Sun Wen‐Hua 
Published: May 2009

AbstractA series of N‐(2‐benzimidazolyquinolin‐8‐yl)benzamidate half‐titanocene chlorides, Cp′TiLCl (C1–C8: Cp′ = C5H5, MeC5H4, or C5Me5; L = N‐(benzimidazolyquinolin‐8‐yl)benzamides)), was synthesized by the KCl elimination reaction of half‐titanocene trichlorides with the correspondent potassium N‐(2‐benzimidazolyquinolin‐8‐yl)benzamide. These half‐titanocene complexes were fully characterized by elemental and NMR analyses, and the molecular structures of complexes C2 and C8 were determined by the single‐crystal X‐ray diffraction. The high stability of the pentamethylcyclopentadienyl complex (C8) was evident by no decomposing nature of its solution in air for one week. The oxo‐bridged dimeric complex (C9) was isolated from the solution of the corresponding cyclopentadienyl complex (C3) solution in air. Complexes C1–C8 exhibited good to high catalytic activities toward ethylene polymerization and ethylene/α‐olefin copolymerization in the presence of methylaluminoxane (MAO) cocatalyst. In the typical catalytic system of C1/MAO, the polymerization productivities were enhanced with either elevating reaction temperature or increasing the ratio of MAO to titanium precursor. In general, it was observed that higher the catalytic activity of the catalytic system lower the molecular weight of polyethylene. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3154–3169, 2009
How oncologists and their patients with advanced cancer communicate about health‐related quality of life
Authors: Rodriguez Keri L. , Bayliss Nichole , Alexander Stewart C. , Jeffreys Amy S. , Olsen Maren K. , Pollak Kathryn I. , Kennifer Sarah L. , Tulsky James A. , Arnold Robert M. 
Published: May 2009

AbstractObjective: To describe the content and frequency of communication about health‐related quality of life (HRQOL) during outpatient encounters between oncologists and their patients with advanced cancer.Methods: We coded for HRQOL talk in a subset of audio‐recorded conversations (each previously found to contain prognostic talk by the oncologist) from the Study of Communication in Oncologist–Patient Encounters Trial, a randomized controlled trial conducted from 2003 to 2008 in two large US academic medical centers and one Veterans Affairs Medical Center.Results: Seventy‐three encounters involved 70 patients and 37 oncologists. Patients were more likely to be female (53%), White (86%), married (78%), and possessing some college education (62%). Most oncologists were male (78%) and White (78%). Mean ages were 59 years for patients and 44 years for oncologists. Every encounter included some talk about HRQOL and HRQOL discussions made up, on average, 25% of the visit time. HRQOL segments described symptoms (50%), general HRQOL (27%), and the following concerns: physical (27%), functional (22%), psychological (9%), social (7%), spiritual (1%), and other (28%). Topics included treatment (56%), disease (14%), and testing (3%), and conversations focused on past (44%), present (68%), and future HRQOL (59%).Conclusions: HRQOL discussions between oncologists and patients are common, but the emphasis is often on treatment (e.g. side effects) and symptoms (e.g. pain) even in patients with advanced disease. Given the often intense emotional experience of patients with advanced cancer, oncologists may need to pay more attention to psychological, social, and spiritual HRQOL concerns. Copyright © 2009 John Wiley & Sons, Ltd.
Safety and tolerability of montelukast in placebo‐controlled pediatric studies and their open‐label extensions
Authors: Bisgaard Hans , Skoner David , Boza Maria L. , Tozzi Carol A. , Newcomb Kathleen , Reiss Theodore F. , Knorr Barbara , Noonan Gertrude 
Published: May 2009

AbstractBackgroundMontelukast is a potent leukotriene‐receptor antagonist administered once daily that provides clinical benefit in the treatment of asthma and allergic rhinitis in children and adults. Because of its wide use as a pediatric controller, there is a need for a further review of the safety and tolerability of montelukast in children.ObjectiveTo summarize safety and tolerability data for montelukast from previously reported as well as from unpublished placebo‐controlled, double‐blind, pediatric studies and their active‐controlled open‐label extension/extended studies.MethodsThese studies evaluated 2,751 pediatric patients 6 months to 14 years of age with persistent asthma, intermittent asthma associated with upper respiratory infection, or allergic rhinitis. These patients were enrolled in seven randomized, placebo‐controlled, double‐blind registration and post‐registration studies and three active‐controlled open‐label extension/extended studies conducted by Merck Research Laboratories between 1995 and 2004.ResultsMontelukast was well tolerated in all studies. Clinical and laboratory adverse experiences for patients treated with montelukast were generally mild and transient. The most frequent clinical adverse events for all treatments (placebo, montelukast, active control/usual care) in virtually all studies were upper respiratory infection, worsening asthma, pharyngitis, and fever.ConclusionThe clinical and laboratory safety profile for montelukast was similar to that observed for placebo or active control/usual care therapies. The safety profile of montelukast did not change with long‐term use. Pediatr Pulmonol. 2009; 44:568–579. © 2009 Wiley‐Liss, Inc.
Phosphonium labeling for increasing metabolomic coverage of neutral lipids using electrospray ionization mass spectrometry
Authors: Woo Hin‐Koon , Go Eden P. , Hoang Linh , Trauger Sunia A. , Bowen Benjamin , Siuzdak Gary , Northen Trent R. 
Published: May 2009

AbstractMass spectrometry has become an indispensable tool for the global study of metabolites (metabolomics), primarily using electrospray ionization mass spectrometry (ESI‐MS). However, many important classes of molecules such as neutral lipids do not ionize well by ESI and go undetected. Chemical derivatization of metabolites can enhance ionization for increased sensitivity and metabolomic coverage. Here we describe the use of tris(2,4,6,‐trimethoxyphenyl)phosphonium acetic acid (TMPP‐AA) to improve liquid chromatography (LC)/ESI‐MS detection of hydroxylated metabolites (i.e. lipids) from serum extracts. Cholesterol which is not normally detected from serum using ESI is observed with attomole sensitivity. This approach was applied to identify four endogenous lipids (hexadecanoyl‐sn‐glycerol, dihydrotachysterol, octadecanol, and alpha‐tocopherol) from human serum. Overall, this approach extends the types of metabolites which can be detected using standard ESI‐MS instrumentation and demonstrates the potential for targeted metabolomics analysis. Published in 2009 by John Wiley & Sons, Ltd.
Characterization of dihydrostreptomycin‐related substances by liquid chromatography coupled to ion trap mass spectrometry
Authors: Pendela Murali , Hoogmartens Jos , Van Schepdael Ann , Adams Erwin 
Published: May 2009

AbstractDihydrostreptomycin sulphate (DHS) is a water‐soluble, broad‐spectrum aminoglycoside antibiotic. For quantitative analysis, the European Pharmacopoeia (Ph. Eur.) prescribes an ion‐pairing liquid chromatography/ultraviolet (LC/UV) method using a C18 stationary phase. Several unknown compounds were detected in commercial samples. Hence, for characterization of these unknown peaks in a commercial DHS sample, the Ph. Eur. method was coupled to mass spectrometry (MS). However, since the Ph. Eur. method uses a non‐volatile mobile phase, each peak eluted was collected and desalted before introduction into the mass spectrometer. The desalting procedure was applied to remove the non volatile salt, buffer and ion‐pairing reagent in the collected fraction. In total, 20 impurities were studied and 14 of them were newly characterized. Five impurities which are already reported in the literature were also traced in this LC/UV method. Copyright © 2009 John Wiley & Sons, Ltd.
Automatic identification of otologic drilling faults: a preliminary report
Authors: Shen Peng , Feng Guodong , Cao Tianyang , Gao Zhiqiang , Li Xisheng 
Published: May 2009

AbstractBackgroundA preliminary study was carried out to identify parameters to characterize drilling faults when using an otologic drill under various operating conditions.MethodsAn otologic drill was modified by the addition of four sensors. Under consistent conditions, the drill was used to simulate three important types of drilling faults and the captured data were analysed to extract characteristic signals. A multisensor information fusion system was designed to fuse the signals and automatically identify the faults.ResultsWhen identifying drilling faults, there was a high degree of repeatability and regularity, with an average recognition rate of >70%.ConclusionsThis study shows that the variables measured change in a fashion that allows the identification of particular drilling faults, and that it is feasible to use these data to provide rapid feedback for a control system. Further experiments are being undertaken to implement such a system. Copyright © 2009 John Wiley & Sons, Ltd.
Using the PhysX engine for physics‐based virtual surgery with force feedback
Authors: Maciel Anderson , Halic Tansel , Lu Zhonghua , Nedel Luciana P. , De Suvranu 
Published: May 2009

AbstractBackgroundThe development of modern surgical simulators is highly challenging, as they must support complex simulation environments. The demand for higher realism in such simulators has driven researchers to adopt physics‐based models, which are computationally very demanding. This poses a major problem, since real‐time interactions must permit graphical updates of 30 Hz and a much higher rate of 1 kHz for force feedback (haptics). Recently several physics engines have been developed which offer multi‐physics simulation capabilities, including rigid and deformable bodies, cloth and fluids. While such physics engines provide unique opportunities for the development of surgical simulators, their higher latencies, compared to what is necessary for real‐time graphics and haptics, offer significant barriers to their use in interactive simulation environments.MethodsIn this work, we propose solutions to this problem and demonstrate how a multimodal surgical simulation environment may be developed based on NVIDIA's PhysX physics library. Hence, models that are undergoing relatively low‐frequency updates in PhysX can exist in an environment that demands much higher frequency updates for haptics. We use a collision handling layer to interface between the physical response provided by PhysX and the haptic rendering device to provide both real‐time tissue response and force feedback.ResultsOur simulator integrates a bimanual haptic interface for force feedback and per‐pixel shaders for graphics realism in real time. To demonstrate the effectiveness of our approach, we present the simulation of the laparoscopic adjustable gastric banding (LAGB) procedure as a case study.ConclusionsTo develop complex and realistic surgical trainers with realistic organ geometries and tissue properties demands stable physics‐based deformation methods, which are not always compatible with the interaction level required for such trainers. We have shown that combining different modelling strategies for behaviour, collision and graphics is possible and desirable. Such multimodal environments enable suitable rates to simulate the major steps of the LAGB procedure. Copyright © 2009 John Wiley & Sons, Ltd.
Immersion and invariance‐based impedance control for electrohydraulic systems
Authors: Kemmetmüller W. , Kugi A. 
Published: May 2009

AbstractThis work deals with the impedance control of electrohydraulic systems based on the concept of immersion and invariance. In the first step, the impedance control task for a basic electrohydraulic system comprising a hydraulic cylinder and a 4/3 proportional valve is analyzed. In order to mitigate the problem of energetic inefficiency and the high demands on the dynamics of the valve, an extended electrohdydraulic system is proposed. By means of a suitable choice of the parameters and an immersion and invariance‐based controller strategy, a significant reduction of both energy consumption and required dynamics of the valve can be obtained. The feasibility of the proposed impedance control strategies is demonstrated by extensive simulation studies. Copyright © 2009 John Wiley & Sons, Ltd.
Method for Quantitative and Molecular Characterisation of Adsorbed Starch Polysaccharides on a Papermaking Pulp by SEC‐MALLS Measurements and Correlation with Paper Strength
Authors: Ulbrich Marco , Radosta Sylvia , Vorwerg Waltraud 
Published: May 2009

AbstractA laboratory‐scale method for determining the molecularly dispersed amount of cationic starch adsorbed on a papermaking pulp was developed. The starch was molecularly dispersed by pressure cooking and was characterised by SEC‐MALLS (Size Exclusion with Multi‐Angle Laser Light Scattering) before and after the adsorption experiment. The adsorbed amount was calculated from the depletion of starch polymers in the starch‐fibre suspension. The molecular composition of the adsorbed starch product was determined from the difference in the SEC chromatograms before and after adsorption. In addition, handsheets were formed to correlate starch adsorption on the pulp with the resulting paper strength. The value of the method was demonstrated using the example of a low DS cationic potato starch derivative. This sample from a slurry process was adsorbed to a significantly higher extent in virtually electrolyte‐free deionised water (DW) than in water with a high electrolyte content (36 degrees German Hardness – 36 dGH). In DW, both amylopectin and amylose were adsorbed on the pulp, whereas in water of 36 dGH only the amylopectin‐rich fraction was adsorbed. A correlation between starch adsorption as a function of water quality and the resulting paper strength was found. The amount and molecular composition of the adsorbed starch product influenced paper properties.
Epidermal Growth Factor Induces the Progeny of Subventricular Zone Type B Cells to Migrate and Differentiate into Oligodendrocytes
Authors: Gonzalez-Perez Oscar , Romero-Rodriguez Ricardo , Soriano-Navarro Mario , Garcia-Verdugo Jose Manuel , Alvarez-Buylla Arturo 
Published: May 2009

Abstract
New neurons and oligodendrocytes are continuously produced in the subventricular zone (SVZ) of adult mammalian brains. Under normal conditions, the SVZ primary precursors (type B1 cells) generate type C cells, most of which differentiate into neurons, with a small subpopulation giving rise to oligodendrocytes. Epidermal growth factor (EGF) signaling induces dramatic proliferation and migration of SVZ progenitors, a process that could have therapeutic applications. However, the fate of cells derived from adult neural stem cells after EGF stimulation remains unknown. Here, we specifically labeled SVZ B1 cells and followed their progeny after a 7-day intraventricular infusion of EGF. Cells derived from SVZ B1 cells invaded the parenchyma around the SVZ into the striatum, septum, corpus callosum, and fimbria-fornix. Most of these B1-derived cells gave rise to cells in the oligodendrocyte lineage, including local NG2+ progenitors, and premyelinating and myelinating oligodendrocytes. SVZ B1 cells also gave rise to a population of highly-branched S100β+/glial fibrillary acidic protein (GFAP)+ cells in the striatum and septum, but no neuronal differentiation was observed. Interestingly, when demyelination was induced in the corpus callosum by a local injection of lysolecithin, an increased number of cells derived from SVZ B1 cells and stimulated to migrate and proliferate by EGF infusion differentiated into oligodendrocytes at the lesion site. This work indicates that EGF infusion can greatly expand the number of progenitors derived from the SVZ primary progenitors which migrate and differentiate into oligodendroglial cells. This expanded population could be used for the repair of white matter lesions.
Disclosure of potential conflicts of interest is found at the end of this article.