bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of strain on the properties of a styrene–butadiene rubber filled with multiwall carbon nanotubes
Authors: Bokobza Liliane , Belin Colette 
Published: April 2007

AbstractMultiwall carbon nanotubes were dispersed in a styrene–butadiene copolymer. The effect of nanotube concentration on the tensile characteristics of the composites was examined. Electrical properties carried out under uniaxial extension show an increase in resistivity upon gradual stretching. A second stretch performed after total release of the stress was shown to lead to a flat response in resistivity. Atomic force microscopy was used to examine orientational effects and changes in filler structure occurring upon application of an uniaxial deformation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Synthesis of urethane oils from palm oil and waste PET bottles
Authors: Saravari O. , Pathomwattanasak K. , Pimpan V. 
Published: April 2007

AbstractWaste PET bottles were depolymerized by propylene glycol at a weight ratio of PET to propylene glycol of 37.5 : 62.5, using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number–average molecular weight range of 240–1107, was obtained. It was further reacted with palm oil and tolylene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.8, with and without methanol acting as a blocking agent. It was found that all the synthesized urethane oils were yellowish transparent liquids of low molecular weights. A lower isocyanate content or the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness, excellent flexibility, and high impact strength. They also showed excellent water resistance, good acid resistance but only fair alkali resistance. Moreover, these prepared urethane oils had better adhesion compared with those of the commercial urethane oil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Polymeric decontaminant: N,N‐dichloro poly(styrene‐co‐divinyl benzene) sulfonamide—synthesis, characterization and efficacy against simulant of sulfur mustard
Authors: Gutch P. K. , Shrivastava R. K. , Dubey D. K. 
Published: April 2007

AbstractN,N‐Dichloro poly(styrene‐co‐divinylbenzene) sulfonamide (1) reacts with 2‐chloro ethyl phenyl sulfide (2), a simulant of sulfur mustard (SM), at room temperature, yielding corresponding nontoxic sulfones and sulfoxides in aqueous as well as aprotic medium. The decontamination reaction was monitored by gas chromatography, and products were identified by gas chromatography–mass spectrometry. N,N‐dichloro poly(styrene‐co‐divinylbenzene) sulfonamide was synthesized by three steps from a commercial starting material sulfonate cation‐exchange resin and characterized by FTIR, and TGA, and compressive strength by universal testing machine. The positive chlorine content of this polymer was checked by standard iodometry titration. The synthesized positive chlorine compound is observed to be a promising against a simulant of SM, chiefly in the situation where use of aqueous medium is precluded. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Simultaneous graft copolymerization of 2‐hydroxyethyl methacrylate and acrylic acid onto polydimethylsiloxane surfaces using a two‐step plasma treatment
Authors: Karkhaneh A. , Mirzadeh H. , Ghaffariyeh A. R. 
Published: April 2007

AbstractAcrylic acid (AAc) and 2‐hydroxyethyl methacrylate (HEMA) mixtures were simultaneously grafted onto the surfaces of polydimethylsiloxane (PDMS) films using a two‐step oxygen plasma treatment (TSPT). The first step of this method includes: oxygen plasma pretreatment of the PDMS films, immersion in HEMA/AAc mixtures, removal from the mixtures, and drying. The second step was carried out by plasma copolymerization of preadsorbed reactive monomers on the surfaces of dried pretreated films. The effects of pretreatment and polymerization time length, monomer concentration, and ratio on peroxide formation and graft amount were studied. The films were characterized by attenuated total reflection Furrier transformer infrared (ATR‐FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential, surface tension, and water contact angle measurements. The ATR‐FTIR spectrum of the modified film after alkaline treatment showed the two new characteristic bands of PHEMA and PAAc. Both increase the polar part of surface tension (γp) after grafting and the evaluation of surface charge at pH 1.8, 7, and 12 confirmed the presence of polar groups on the surface of grafted films with a mixture of HEMA/AAc. Morphological studies using both AFM and SEM evaluation illustrated various amounts of grafted copolymer on the surface of PDMS films. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Morphology, thermal, and mechanical properties of acrylonitrile–butadiene–styrene/carbon black composites
Authors: Shenavar A. , Abbasi F. 
Published: April 2007

AbstractAcrylonitrile–butadiene–styrene (ABS) polymers are susceptible to degradation that increases the yellowness of the polymer, distorts the surface glossy, and affects the mechanical properties. One way to protect ABS against degradation is the addition of carbon black (CB) that can act as a stabilizer. In this work, CB was dispersed in ABS through melt‐compounding. Electron microscopy was used to study the morphology of the filled‐ and unfilled‐ABS, and revealed that the CB particles/aggregates were distributed within the styrene–acrylonitrile (SAN) phase and around the PB phase. The results of the Fourier transform infrared spectroscopy showed that upon processing of ABS, crosslinking in the polybutadiene (PB) phase was the governing degradation mechanism. Increasing the CB content resulted in increasing the heat stability of the ABS/CB compounds, which was confirmed by thermogravimetric analysis. The DTA results showed that the PB degradation peak occurring at about 395°C was disappeared by addition of CB. Impact strength test was performed to study the effect of CB on the toughness of ABS. Impact strength was reduced with increasing CB loading. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Production and characterization of polypropylene fiber upon addition of selective peroxide during melt spinning and comparison with conventional polypropylene fibers
Authors: Kalantari Bahareh , Semnani Rahbar Ruhollah , Mojtahedi M. R. M. , Mousavi Shoushtari S. A. , Khosroshahi Ali 
Published: April 2007

AbstractIn the present work, effect of selective peroxide on reactor grade polypropylene (PP) (known as V30S) during melt spinning process on the physical and thermal properties of as‐spun resultant multifilament yarn was studied. Attempts have also been made to compare this yarn sample with other fiber samples produced from reactor and controlled rheology grades polypropylene. The results show that the multifilament yarn spun from V30S/Peroxide sample shows higher birefringence and tensile strength and also lower modulus, elongation at break, and shrinkage compared with that of spun from pure V30S granule. Density and thermal behavior studies show low variations compared with original sample. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Organic/inorganic hybrid of polyaniline/BaTiO3 composites and their electrorheological and dielectric characteristics
Authors: Fei Fang Fei , Hye Kim Ji , Jin Choi Hyoung , Seo Yongsok 
Published: April 2007

AbstractBarium titanate (BaTiO3) inorganic particles which possess large electronic resistance and excellent dielectric properties were employed to synthesize conducting polyaniline (PANI)/BaTiO3 composites via an in situ oxidative polymerization, since conducting PANI/inorganic composites have been considered as a superior candidate of electrorheological (ER) fluids because of their physical properties, unique structure, and the combined merits of the two phases. The influence of the fraction of BaTiO3 particles in the as‐synthesized composites on the physical properties (morphology and crystal structure) and the ER behaviors were examined. Yield stress data obtained were analyzed based on the universal yield stress equation as a function of applied electric field and it was found that the universal yield stress equation collapses these data onto a single curve independent of BaTiO3 particle concentration. Their shear stresses under an applied electric field were also found to be fitted well with the Cho–Choi–Jhon model. In addition, the investigated dielectric spectra were found to be useful to interpret the differences in the ER performances for the PANI/BaTiO3 composite based ER fluids. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis and Anti‐HIV‐1 Activity of New MKC‐442 Analogues with an Alkynyl‐Substituted 6‐Benzyl Group*
Authors: Aly Youssef L. , Pedersen Erik B. , La Colla Paolo , Loddo Roberta 
Published: April 2007

AbstractSynthesis and antiviral activities are reported of a series of 6‐(3‐alkynyl benzyl)‐substituted analogues of MKC‐442 (6‐benzyl‐1‐(ethoxymethyl)‐5‐isopropyluracil), a highly potent agent against HIV. The 3‐alkynyl group is assumed to give a better stacking of the substituted benzyl group to reverse transcriptase (RT) and this was believed to improve antiviral activity against HIV‐1. The bromo derivatives, 5‐alkyl‐6‐(3‐bromo‐benzyl)‐1‐ethoxymethyl derivatives 7a, b and 5‐alkyl‐6‐(3‐bromobenzyl)‐1‐allyloxymethyl derivatives 9a, b, showed activity against HIV on the same level as their corresponding analogues 10a–d with a 3‐trimethylsilylalkynylbenzyl substituent and their desilylated analogues 11a–d. However, they all showed activity against HIV‐1 wild type in the range of more than 10fold lower than the one of MKC‐442. Moderate activity against Y181C and Y181C + K103N mutated strains was also observed and, in some cases, they were marginally better than those found for MKC‐442. A few amino‐DABO and S‐DABO analogues were also synthesized but they were found to be inactive against HIV.
On the Tacticity of Polynorbornenes with 5,6‐endo Pendant Groups That Contain Substituted Aryl Chromophores
Authors: Lin Wei‐Yu , Wang Hsian‐Wen , Liu Zhi‐Chang , Xu Jun , Chen Chih‐Wei , Yang Yun‐Chin , Huang Shou‐Ling , Yang Hsiao‐Ching , Luh Tien‐Yau 
Published: April 2007

AbstractTwo dimers and a series of polymers with 5,6‐endo pendant aryl groups that contain different substituents at the para positions were synthesized. The conformation and stereochemistry of the dimers and polymers were determined by nonlinear optical analysis (EFISH) as well as UV/Vis and 13C NMR spectroscopy. The chemical shifts of C7 for the polymers appeared as two peaks in the 13C NMR spectra when the substituents are electron‐withdrawing groups. The percentage decrease in the relative extinction coefficient of the polymers, εd, was linearly related to the Hammett constant σ. Polynorbornenes with electron‐withdrawing substituents may adopt isotactic stereochemistry with all pendant groups aligned in one direction. The nature of the interactions between neighboring chromophores may be one of the most important factors in directing the stereoregularity and conformation of these polymers. The corresponding polymers derived from the exo isomers appeared to be less stereoregular.
Modeling the Short‐, Middle‐ and Long‐Term Viral Load Responses for Comparing Estimated Dynamic Parameters
Authors: Huang Yangxin 
Published: April 2007

AbstractA virologic marker, the number of HIV RNA copies or viral load, is currently used to evaluate antiviral therapies in AIDS clinical trials. This marker can be used to assess the antiviral potency of therapies, but is easily affected by drug exposures, drug resistance and other factors during the long‐term treatment evaluation process. The study of HIV dynamics is one of the most important development in recent AIDS research for understanding the pathogenesis of HIV‐1 infection and antiviral treatment strategies. Although many HIV dynamic models have been proposed by AIDS researchers in the last decade, they have only been used to quantify short‐term viral dynamics and do not correctly describe long‐term virologic responses to antiretroviral treatment. In other words, these simple viral dynamic models can only be used to fit short‐term viral load data for estimating dynamic parameters. In this paper, a mechanism‐based differential equation models is introduced for characterizing the long‐term viral dynamics with antiretroviral therapy. We applied this model to fit different segments of the viral load trajectory data from a simulation experiment and an AIDS clinical trial study, and found that the estimates of dynamic parameters from our modeling approach are very consistent. We may conclude that our model can not only characterize long‐term viral dynamics, but can also quantify short‐ and middle‐term viral dynamics. It suggests that if there are enough data in the early stage of the treatment, the results from our modeling based on short‐term information can be used to capture the performance of long‐term care with HIV‐1 infected patients. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrahigh‐Throughput Screening to Identify E. coli Cells Expressing Functionally Active Enzymes on their Surface
Authors: Becker Stefan , Michalczyk Anja , Wilhelm Susanne , Jaeger Karl‐Erich , Kolmar Harald 
Published: April 2007

AbstractWe show here that E. coli bacteria that display esterases or lipases on their cell surface together with horseradish peroxidase (HRP) are capable of hydrolysing carboxylic acid esters of biotin tyramide. The tyramide radicals generated by the coupled lipase–peroxidase reaction were short‐lived and therefore became covalently attached to reactive tyrosine residues that were located in close vicinity on the surface of a bacterial cell that displayed lipase activity. Up to 120 000 biotinylated tyramide derivatives could be covalently coupled through HRP activation to the surface of a single living E. coli cell. Differences in cellular esterase activity were found to correlate with the amount of biotin tyramide deposited on the cell surface. Selective biotin tyramide labelling of cells that had lipase activity allowed their isolation by magnetic cell sorting from a 1:106 mixture of control cells. This strategy of covalently attaching a biotin label to esterase‐proficient bacteria might open new avenues to ultrahigh‐throughput screening of enzyme libraries for hydrolytic enzymes with enhanced activities or enantioselectivities.
Factorial analysis and psychometric properties of the revised Valencia scale of attitudes and beliefs towards hypnosis‐client version
Authors: Carvalho Claudia , Capafons Antonio , Kirsch Irving , Espejo Begona , Mazzoni Giuliana , Leal Isabel 
Published: April 2007

AbstractPsychometric properties and factorial structure of the Revised Valencia Scale of Attitudes and Beliefs toward Hypnosis – Client Version using a Portuguese sample are presented. Exploratory factor analysis on a Portuguese population of undergraduate college students (N = 444) yielded 8 factors: ‘Interest/Liking’, ‘Memory/Magic’, ‘Help’, ‘Control’, ‘Cooperation’, ‘Marginal’, ‘Fear’ and ‘Automaton’. The overall 8‐factor structure is similar to the one found in the therapist version of the scale, and as in the therapist version, each factor of the client version showed good internal consistency and reliability. Differences among participants that had and had not experienced hypnosis previously were also assessed. The results indicated that participants with prior experience of hypnosis scored higher on factors indicating positive attitudes and accurate beliefs (‘Interest/Liking’, ‘Help’, ‘Control’ and ‘Cooperation’), whereas participants that had not experienced hypnosis scored higher in factors indicating misconceptions about hypnosis (‘Memory/Magic’, ‘Fear’, ‘Marginal’ and ‘Automaton’). These results indicate that the scale is sensitive to changes in attitudes and beliefs toward hypnosis brought about by the experience of hypnosis in a scientific context. Copyright © 2007 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
Pharmaceutical Strategy and Innovation: An Academics Perspective
Authors: Baxendale Ian R. , Hayward John J. , Ley Steven V. , Tranmer Geoffrey K. 
Published: April 2007

AbstractThe pharmaceutical industry is under increasing pressure on many fronts, from investors requiring larger returns to consumer groups and health authorities demanding cheaper and safer drugs. It is also feeling additional pressure from the infringement upon its profit margins by generic drug producers. Many companies are aggressively pursuing outsourcing contracts in an attempt to counter many of the financial pressures and streamline their operations. At the same time, the productivity of the pharmaceutical industry at its science base is being questioned in terms of the number of products and the timeframes required for each company to deliver them to market. This has generated uncertainties regarding the current corporate strategies that have been adopted and the levels of innovation being demonstrated. In this essay we discuss these topics in the context of the global pharmaceutical market, investigating the basis for many of these issues and highlighting the hurdles the industry needs to overcome, especially as they relate to the chemical sciences.
Pilot study of regional, hepatic intra‐arterial paclitaxel in patients with breast carcinoma metastatic to the liver
Authors: Camacho Luis H. , Kurzrock Razelle , Cheung Alex , Barber Diane F. , Gupta Sanjay , Madoff David C. , Wallace Michael J. , Kim E. Edmund , Curley Steven A. , Hortobagyi Gabriel N. , Mavligit Giora 
Published: April 2007

AbstractBACKGROUND.Approximately 25% of patients with metastatic breast carcinoma develop hepatic involvement during the course of their disease that further affects their survival. Systemic paclitaxel is safe and has demonstrated good antitumor activity against breast carcinoma. The objective of this prospective study was to determine the safety and antitumor activity of hepatic intra‐arterial paclitaxel therapy.METHODS.Ten patients with breast carcinoma and dominant liver metastases received monthly, inpatient, 24‐hour, continuous hepatic infusions of paclitaxel at 200 mg/m2 through an intra‐arterial catheter, which was placed using a percutaneous transfemoral approach.RESULTS.The mean patient age at the time of treatment was 51 years. Fifty‐six courses of paclitaxel were delivered. The most common treatment‐related toxicities were leukopenia, fatigue, nausea, and vomiting. No procedure‐related complications were observed. Three patients (30%) attained partial responses that lasted for 6 months, 7 months, and 48 months; and 4 other patients had stable disease for 5 months to 9 months. One patient underwent liver resection after receiving hepatic arterial infusions of paclitaxel and remained disease free for 48 months. Eight patients had received prior systemic taxane therapy alone or with other cytotoxic agents. However, no association between previous taxane exposure and the efficacy of the current regimen was established.CONCLUSIONS.Hepatic intra‐arterial therapy with paclitaxel at the dose level and on the schedule used in this study was safe and well tolerated and had reasonable antitumor activity against breast carcinoma involving the liver. Previous taxane exposure did not hamper the potential benefit of this approach. This regimen alone or in combination with targeted therapies deserves further investigation in patients with dominant liver metastases from breast carcinoma. Cancer 2007. © 2007 American Cancer Society.
Dehydration and Dehydrogenation of Alcohols with Mononuclear Cationic Vanadium Oxides in the Gas Phase and Energetics of VOnH0/+ (n = 2, 3)
Authors: Engeser Marianne , Schröder Detlef , Schwarz Helmut 
Published: April 2007

AbstractThe ion/molecule reactions of selected alcohols with the vanadium oxide cations VO+ and VO2+ are studied by Fourier‐transform ion‐cyclotron resonance (FT‐ICR) mass spectrometry. Dehydrogenation is the dominating reaction pathway for methanol and allyl alcohols. With larger or less unsaturated alcohols, dehydration and carbocation formations prevail. While the valence in VO+ remains unchanged during alcohol dehydrogenation, VO2+ is reduced to VIII. Thermochemical data for VO2H0/+, VO3H and VO3H2+ are derived by means of ICR bracketing. The experimental results are further complemented by ab initio calculations using density functional theory. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Surfactant‐coated single‐walled carbon nanotubes as a novel pseudostationary phase in capillary EKC
Authors: Suárez Beatriz , Simonet Bartolomé M. , Cárdenas Soledad , Valcárcel Miguel 
Published: April 2007

AbstractThe analytical potential of the use of surfactant‐coated single‐walled carbon nanotubes (SC‐SWNTs) as pseudostationary phase in CE is described. The pseudostationary phase shows an efficient alternative in enhancing electrochromatographic resolution of compounds which are capable of interacting with a nanotube surface, such as aromatic compounds. In general, the resolution is enhanced by increasing nanotube concentration in the buffer but the maximum amount of SWNTs that can be added to background electrolyte was found limited by compatibility with the UV/visible detection. As an alternative, a low‐extension partial filling was used, consisting of the introduction into the capillary of concentrated SC‐SWNT, just before the sample, with a plug length similar to the sample one. This has been showed as a reliable procedure in increasing resolution and sensitivity by sweeping phenomena. Finally, the potential of SC‐SWNTs to perform chiral separations is discussed.
Sample stacking for the analysis of catechins by microemulsion EKC
Authors: Huang Hsi‐Ya , Huang I.‐Yun , Liang Hsin‐hui , Lee Szetsen 
Published: April 2007

AbstractIn this study, an on‐line concentration method, ASEI (anion‐selective exhaustive injection)‐sweeping technology which was coupled with microemulsion EKC (MEEKC), was used to analyze and detect six catechins ((−)‐epicatechin, (+)‐catechin, (−)‐epigallocatechin gallate, (−)‐epicatechin gallate, (−)‐epigallocatechin, and (−)‐gallocatechin). In addition to the effects of the buffer pH and electrolyte concentration on stacking, the compositions of microemulsion (types of oil phase, and types and levels of cosurfactant) also dominated the stacking effect of catechins. In MEEKC, the effect of the type of oil in microemulsion on separation mechanism is often unclear. This study had demonstrated that the oil type in microemulsion indeed altered the affinity of oil droplets with analytes. Finally, this proposed ASEI‐sweeping MEEKC method was able to detect trace level of catechins in food products that was not previously possible by a normal MEEKC method.