bluuebunny/crossref_metadata_2025_split huggingface dataset:
pH‐ and thermo‐responsive properties of poly(N‐vinylcaprolactam‐co‐acrylic acid) copolymers
Authors: Shtanko Nadejda I , Lequieu Wouter , Goethals Eric J , Du Prez Filip E 
Published: January 2005

AbstractCopolymers with both pH‐ and thermo‐responsiveness were synthesized by free radical copolymerization of N‐vinylcaprolactam with small amounts of acrylic acid. The copolymers have been prepared in various solvents and characterized by gel permeation chromatography, Fourier‐transform infrared (FTIR) spectroscopy and titration. The phase separation behaviour of these copolymers was studied in water and buffered solutions at a variety of pH values and temperatures by means of attenuated total reflectance FTIR and cloud‐point measurements. The aqueous solutions of the copolymers showed a temperature, pH and molecular weight dependent phase‐separation behaviour. Copyright © 2003 Society of Chemical Industry
Effect of organoclay on the curing reactions in bismaleimide/diallyl bisphenol a resin
Authors: Hu Xiao , Meng Jiru 
Published: January 2005

Abstract4,4′‐Bismaleimidodiphenyl methane (BMPM)/2,2′‐diallyl bisphenol A (DBA)/organoclay nanocomposites were synthesized. The effects of organoclays on the curing reactions in the BMPM/DBA system at low temperatures (ene reaction) and high temperatures (Diels–Alder reaction, homopolymerization of BMPM, and alternative copolymerization) were investigated with differential scanning calorimetry and Fourier transform infrared techniques. The results showed that these reactions were affected to different extents in the presence of organoclays. The ene reaction was accelerated to different degrees depending on the acidity of the modifier and the accessibility of the organoclays used. The exfoliation degree of organoclays in the prepolymers showed great effects on the curing behavior of BMPM/DBA. When an organoclay was less intercalated, the curing behavior of the system was different from that of neat BMPM/DBA. On the other hand, when the organoclay was better exfoliated in prepolymers, the curing behavior of the system was similar to that of the neat BMPM/DBA system. However, even in this case, the reactions at high temperatures occurred in different ways in the presence of an organoclay. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 994–1006, 2005
Anionic polymerization of styrenic macromonomers of polyisoprene, polybutadiene, and polystyrene
Authors: Vazaios Aggelos , Hadjichristidis Nikos 
Published: January 2005

AbstractAnionic polymerization and high‐vacuum techniques were used to prepare a series of well‐defined polyisoprene, polybutadiene, and polystyrene polymacromonomers. The procedure involved (1) the synthesis of styrenic macromonomers in benzene by the selective reaction of the corresponding macroanion with the chlorine of 4‐(chlorodimethylsilyl)styrene (CDMSS) and (2) the in situ anionic polymerization of the macromonomer without previous isolation. The synthesis of the macromonomers [polyisoprene macromonomer: 11 samples, weight‐average molecular weight (Mw) = 1000–18,000; polybutadiene macromonomer: 5 samples, Mw = 2000–4000; and polystyrene macromonomer: 2 samples, Mw = 1300 and 3600] was monitored by size exclusion chromatography with refractive index/ultraviolet detectors. Selectivity studies with CDMSS indicated that polybutadienyllithum had the highest selectivity, and polystryryllithium the lowest. From kinetic studies it was concluded that the polymerization half‐life times were longer but comparable to those of styrene, and they appeared to only slightly depend on the molecular weight of the macromonomer chain (at least for low degrees of polymerization of the polymacromonomer and for Mw < 7000 for the macromonomer side chain). Dependence on the polymerization degree of the polymacromonomer product was also observed. All the prepared polymacromonomers were characterized by size exclusion chromatography with refractive index, ultraviolet and two‐angle laser light scattering detectors, and NMR spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1038–1048, 2005
Synthesis and characterization of telechelic polymethacrylates via RAFT polymerization
Authors: Lima Vincent , Jiang Xulin , Brokken‐Zijp José , Schoenmakers Peter J. , Klumperman Bert , Van Der Linde Rob 
Published: January 2005

AbstractThe reversible addition–fragmentation chain transfer (RAFT) polymerization technique has been employed to synthesize linear α,ω ‐telechelic polymers with either hydroxyl or carboxyl end groups. Methyl methacrylate, butyl methacrylate, and butyl acrylate were polymerized with RAFT polymerization. The polymerizations exhibited the usual characteristics of living processes. Telechelic polymethacrylates were obtained from a hydroxyl monofunctional RAFT polymer with a two‐step chain‐end modification procedure of the dithioester end group. The procedure consisted of an aminolysis followed by a Michael addition on the resulting thiol. The different steps of the procedure were followed by detailed analysis. It was found that this route was always accompanied by side reactions, resulting in disulfides and hydrogen‐terminated polymer chains as side products next to the hydroxyl‐terminated telechelic polymers. Telechelic poly(butyl acrylates) with carboxyl end groups were produced in a single step procedure with difunctional trithiocarbonates as RAFT agents. The high yield in terms of end group functionality was confirmed by a new critical‐liquid‐chromatography method, in which the polymers were separated based on acid‐functionality and by mass spectrometry analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 959–973, 2005
Alternative approach to the design of thermosensitive polymers: The addition of hydrophobic groups to the ends of hydrophilic polyether
Authors: Mori Takeshi , Shiota Yuuki , Minagawa Keiji , Tanaka Masami 
Published: January 2005

AbstractWe synthesized thermosensitive polymers by adding hydrophobic groups to the ends of a hydrophilic polyether, poly(ethylene oxide‐co‐propylene oxide). The cloud points of the polymers were controlled by the molecular weight of the polyether and the kind of hydrophobic end group. The polymers showed relatively sharp phase transitions, as observed by turbidimetry. The order of the cloud points of the polymers with various end groups did not follow that of the critical micelle concentrations of the polymers determined with fluorescence measurements with pyrene as a probe. The cloud points of the polymers linearly decreased with increasing concentrations of salts (Na2SO4 and Na3PO4). The slopes of the linear lines were almost constant, regardless of the kind of hydrophobic group and the molecular weight of the polyether. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1007–1013, 2005
Cationic polymerization of seven‐membered cyclic monothiocarbonate 1,3‐dioxepan‐2‐thione
Authors: Ochiai Bungo , Yoshii Kouichi , Nagai Daisuke , Endo Takeshi 
Published: January 2005

AbstractThe cationic ring‐opening polymerization of a seven‐membered cyclic monothiocarbonate, 1,3‐dioxepan‐2‐thione, produced a soluble polymer through the selective isomerization of thiocarbonyl to a carbonyl group {[SC(CO)O(CH2)4]n}. The molecular weights of the polymer could be controlled by the feed ratio of the monomer to the initiators or the conversion of the monomer during the polymerization, although some termination reactions occurred after the complete consumption of the monomer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1014–1018, 2005
Raf‐1 expression may influence progression to androgen insensitive prostate cancer
Authors: Mukherjee R. , Bartlett J.M.S. , Krishna N.S. , Underwood M.A. , Edwards J. 
Published: January 2005

AbstractBACKGROUNDRecent evidence has implicated the MAP kinase pathway with the development of androgen insensitive prostate cancer (AIPC). We have previously reported gene amplification of critical members of this pathway with the development of androgen insensitive disease.METHODSProtein expression of Raf‐1 was analyzed using immunohistochemistry (IHC) in a database of 65 paired tumor specimens obtained before and after the development of AIPC and correlated with other members of the pathway.RESULTSPatients whose Raf‐1 expression rose with development of AIPC had a significantly shorter median time to biochemical relapse compared to those whose expression fell or remained unchanged (1.16 vs. 2.62 years, P = 0.0005). In AIPC tumors, expression of Raf‐1 correlated significantly with expression of HER2 and with expression of c‐fos.CONCLUSIONSWe conclude that the HER2/Raf‐1/AP‐1 axis may promote the development of AIPC, leading to early relapse. Members of the pathway may act as novel therapeutic targets for patients. © 2005 Wiley‐Liss, Inc.
Selective targeting of indel‐inferred differences in spatial structures of highly homologous proteins
Authors: Cherkasov Artem , Nandan Devki , Reiner Neil E. 
Published: January 2005

AbstractRecent findings have shown that the protein elongation factor‐1α (EF‐1α) from the eukaryotic pathogen Leishmania donovani possesses virulence properties. This was unexpected, since it has greater than 80% sequence identity with its human homologue. Given that EF‐1α is essential for cell survival, in principle, it can be considered an attractive drug target. However, the challenge is to be able to selectively target the protein so as not to affect function of the human homologue. While a limited number of discrete differences were scattered throughout the sequence, most of the difference between these 2 homologues could be attributed to a 12–amino acid insert present in human EF‐1α and absent from the leishmania sequence. In the present study, we modeled the spatial differences in structures of human and L. donovani EF‐1α's inferred by this insertion–deletion (or “indel”). The protein models were used to develop antibodies directed specifically toward the deletion region of the pathogen protein. The strategy described allowed successful selective targeting of this putative leishmania virulence factor while avoiding recognition of the highly similar human EF‐1α homologue. These findings may establish a new strategy for the development of antagonists directed against certain pathogenic targets having close human homologues. Proteins 2005 © 2005 Wiley‐Liss, Inc.
A fuzzy clustering–ranking algorithm and its application for alarm operating optimization in chemical processing
Authors: Geng Zhiqiang , Zhu Qunxiong , Gu Xiangbai 
Published: January 2005

AbstractAlarm overload in modern chemical plants presents many difficulties in decision and diagnosis. Management and optimization of alarm information are challenging work that must be confronted everyday. A new system alarm optimization technique, based on a fuzzy clustering–ranking (FCR) algorithm, is proposed according to the correlativity among process‐measured variables. The fuzzy clustering method is used to rationally group and cluster the information matrix of alarm variables to effectively decrease alarms under safety production. Moreover, the fuzzy difference driving (FDD) algorithm is used to rank the clustering center and alarm variables in every cluster, based on objective process characteristics. Furthermore, the validity of the proposed algorithm and solution is verified by application of a practical ethylene cracking furnace alarm system. The proposed method is an effective and reliable alarm‐management method that can optimize process operation and improve plant safety in the chemical industry. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Comparative acaricide susceptibility and detoxifying enzyme activities in field‐collected resistant and susceptible strains of Tetranychus urticae
Authors: Van Leeuwen Thomas , Van Pottelberge Steven , Tirry Luc 
Published: January 2005

AbstractA field‐collected strain (MR‐VL) of the two‐spotted spider mite, Tetranychus urticae Koch, exhibited strong resistance to bifenthrin, dicofol and fenbutatin oxide in comparison with a susceptible laboratory strain (LS‐VL). The MR‐VL strain was screened for cross‐resistance with several currently used acaricides. Cross‐resistance was detected with clofentezine (RR = 2631), dimethoate (RR = 250), chlorfenapyr (RR = 154), bromopropylate (RR = 25), amitraz (RR = 17), flucycloxuron (RR = 15) and azocyclotin (RR = 7). Abamectin, acequinocyl, bifenazate, tebufenpyrad and spirodiclofen did not show any signs of cross‐resistance. Enhanced detoxification by increased activity of mono‐oxygenases (MO) and esterases is at least partially responsible for the observed resistance and cross‐resistance. MO assays with 7‐ethoxycoumarin (7‐EC) were optimised and 7‐ethoxy‐4‐trifluoromethylcoumarin (7‐EFC), a new MO‐substrate, was evaluated for the first time in T urticae and proved to be a good alternative to 7‐EC. Approximately 3‐ and 4‐fold higher MO activity was detected with 7‐EFC and 7‐EC respectively in the MR‐VL strain. Kinetic parameters of general esterase assays with 4‐nitrophenyl acetate and 1‐naphthyl acetate as substrate indicated that more esterases were present in the MR‐VL strain. A first attempt was made to classify the esterases present in T urticae. Acetyl‐, aryl‐ and carboxyl‐esterases were detected with the use of inhibitors after separation by native PAGE. Glutathione‐S‐transferases did not seem to play any role in the observed resistance and no differences were detected when the general oxidative capacities of the two strains were compared. Copyright © 2005 Society of Chemical Industry
Effect of hexaflumuron on mortality of the Western subterranean termite (Isoptera: Rhinotermitidae) during and following exposure and movement of hexaflumuron in termite groups
Authors: Haagsma Karl A , Rust Michael K 
Published: January 2005

AbstractThe effects of hexaflumuron consumption on the mortality of workers of the Western subterranean termite, Reticulitermes hesperus Banks, were observed following various exposures to a substrate treated with 14C‐labeled hexaflumuron at 5 g kg−1. Uptake of hexaflumuron by workers was rapid, peaking at approximately 280 ng hexaflumuron per termite 12 days after exposure. The onset of mortality began at day 8, with cumulative mortality reaching approximately 96% by day 45. Excretion of hexaflumuron from worker termites was rapid following various exposure periods, half‐lives ranging from 2.1 to 4.7 days. Trophallaxis among worker termites was efficient, hexaflumuron levels in recipient termites approaching two‐thirds of levels present in donor termites feeding continuously on hexaflumuron‐treated filter paper. The effect of donor‐to‐recipient group ratios was negligible on the amounts of hexaflumuron transferred from donors to recipients. In laboratory tests, hexaflumuron diffused from a feeding source within 7 days. The presence of additional food sources appeared to inhibit movement of hexaflumuron. Movement of hexaflumuron by cannibalism and coprophagy occurred, but was significant only when termites were starved. Hexaflumuron also appeared to adversely affect egg development by preventing hatch. Hexaflumuron was readily transferred through termite groups, effectively suppressing laboratory populations of R hesperus. Variable efficacy in field situations employing baiting with hexaflumuron in southern California may be a consequence of sporadic feeding at bait stations, the rapid clearance of hexaflumuron from individual termites, and the difficulties in bait presentation (low foraging activity, poor bait station foraging fidelity) inherent in the foraging characteristics of the Western subterranean termite. Copyright © 2005 Society of Chemical Industry
Negative ion electrospray mass spectra of the maculatin peptides from the tree frogs Litoria genimaculata and Litoria eucnemis
Authors: Brinkworth Craig S. , Bowie John H. 
Published: January 2005

AbstractCollision‐induced fragmentations of deprotonated maculatin 1 peptides provide significant sequencing information. When the peptide lacks those residues which can fragment through their alpha side chains (e.g. Thr, Ser, Glu and Gln in this study) the basic α and β′ backbone cleavages occur from the [MH]− anion. When Thr, Ser, Glu and Gln are present, the ease of side‐chain fragmentation of these residues is: Thr (loss of MeCHO) > Ser (CH2O) > Glu (H2O) > Gln (NH3). When one of more of these residues is (are) present, the α and β′ cleavages often occur from a fragment rather than the [MH]− anion, e.g. for Thr, the [(MH)−MeCHO]− anion. These four residues also initiate γ backbone cleavage reactions. The relative abundances of peaks resulting from γ cleavage are Glu > Ser = Thr > Gln for maculatin 1 spectra. An unusual Gln19/Ile17 cyclisation/cleavage reaction occurs in maculatin spectra: the peptide [MH]− anion must adopt a helical conformation in order for these two groups to interact. Analogous fragmentations have been reported previously in the negative ion spectra of the caerin 1 peptides. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of tetracyclines in honey by high‐performance liquid chromatography/tandem mass spectrometry
Authors: Khong Seu‐Ping , Hammel Yves‐Alexis , Guy Philippe A. 
Published: January 2005

AbstractA confirmatory method coupling liquid chromatography to tandem mass spectrometry (LC/MS/MS) is described for the determination of tetracycline, oxytetracycline, doxycycline and chlortetracycline in honey. Demeclocycline, another tetracycline molecule not reported for its usage in honey, was used as internal standard to quantify the four analytes. The sample preparation entails a clean‐up on an Oasis HLB solid‐phase extraction cartridge and analyses were realised by LC/MS/MS in selected reaction monitoring mode. The stability of tetracyclines was checked under various storage conditions at −20, +4 and +20°C (both under dark and light exposures). Indeed, tetracyclines are not stable molecules and the epimerisation phenomenon was evaluated in this work. Appropriate correction factors of the MS/MS responses of each epimer were studied for each of the four tetracyclines to accurately quantify them. Moreover, the matrix effects encountered during the LC/MS/MS analyses were also studied in spiked experiments from blank honey samples of various geographical origins and different flower types. Copyright © 2005 John Wiley & Sons, Ltd.
Ionization and fragmentation of N‐linked glycans as silver adducts by electrospray mass spectrometry
Authors: Harvey David J. 
Published: January 2005

Abstract[M+Ag]+ ions were produced by electrospray from neutral high‐mannose, hybrid and complex N‐linked glycans obtained from bovine ribonuclease, chicken egg glycoproteins, bovine fetuin and porcine thyroglobulin by the addition of silver nitrate to the electrospray solvent. Both singly and doubly charged ions were produced but, as the signals were split between the two silver isotopes, sensitivity was not as high as with the sodium adducts reported earlier. Collision‐induced dissociation (CID) spectra were dominated by ions produced by glycosidic cleavages, mainly of the B‐ and Y‐type. Internal cleavage ions involving both B and Y cleavages were very prominent but cross‐ring fragments were generally of very low abundance or absent. Silver was very efficient at cleaving the glycosidic bonds, so much so that spectra tended to contain glycosidic ions at most possible combinations of the constituent monosaccharides. Copyright © 2005 John Wiley & Sons, Ltd.
A proof of a conjecture of Buck, Chan, and Robbins on the expected value of the minimum assignment
Authors: Wästlund Johan 
Published: January 2005

AbstractWe prove the main conjecture of the paper “On the expected value of the minimum assignment” by Marshall W. Buck, Clara S. Chan, and David P. Robbins [Random Structures Algorithms 21 (2002), 33–58]. This is an exact formula for the expected value of a certain type of random assignment problem. It generalizes the formula 1 + 1/4 + … 1/n2 for the n by n exp(1) random assignment problem. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
The effect of exercise on the intensity of low back pain in pregnant women
Authors: Garshasbi A. , Faghih Zadeh S. 
Published: January 2005

AbstractObjectiveTo investigate the effect of exercise during pregnancy on the intensity of low back pain and kinematics of spine.MethodA prospective randomized study was deigned. 107 women participated in an exercise program three times a week during second half of pregnancy for 12 weeks and 105 as control group. All filled a questionnaire between 17–22 weeks of gestation and 12 weeks later for assessment of their back pain intensity. Lordosis and flexibility of spine were measured by Flexible ruler and Side bending test, respectively, at the same times. Weight gain during pregnancy, Pregnancy length and neonatal weight were recorded.ResultLow back pain intensity was increased in the control group. The exercise group showed significant reduction in the intensity of low back pain after exercise (p<0.0001). Flexibility of spine decreased more in the exercise group (p<0.0001). Weight gain during pregnancy, pregnancy length and neonatal weight were not different between the two groups.ConclusionExercise during second half of the pregnancy significantly reduced the intensity of low back pain, had no detectable effect on Lordosis and had significant effect on flexibility of spine.
Oral misoprostol versus intracervical dinoprostone for induction of labor
Authors: Langenegger E.J. , Odendaal H.J. , Grové D. 
Published: January 2005

AbstractObjectives: To compare oral misoprostol with dinoprostone for induction of labor and their effects on the fetal heart rate patterns. Methods: In a randomized controlled trial, 200 patients received either misoprostol 50 μg orally for every 4 h, or dinoprostone 0.5 mg intracervically for every 6 h. Cardiotocographic recordings, in 10‐min windows 30, 60, and 80 min after prostaglandin administration during induction and continuously during labor, were compared between the two groups. Primary outcome for effectiveness and safety was assessed in terms of the number of vaginal deliveries within 24 h and fetal heart rate abnormalities during induction and labor respectively. Results: Data from 96 patients in the misoprostol group and 95 in the dinoprostone group were analyzed. There were no significant differences in respect of the number of vaginal deliveries within 24 h (RR 1.12; 95% CI 0.88–1.42). The frequency of suspicious and pathological fetal heart rate patterns did not differ significantly but significantly more cardiotocographs in the dinoprostone group had non‐reassuring baseline variability 60 min after dose administration (RR 0.33; 95% CI 0.14–0.77). Maternal and neonatal outcomes did not differ significantly. Conclusion: Oral misoprostol is as effective as intracervical dinoprostone for induction of labor with no difference in the frequency of fetal heart rate abnormalities.
WHAT IS ARAB ISLAMIC RHETORIC? RETHINKING THE HISTORY OF MUSLIM ORATORY ART AND HOMILETICS
Authors: Halldén Philip 
Published: January 2005

But about this same time, we were exposed to an even stranger kind of rhetoric, the rhetoric of the Middle Eastern world…. This was a rhetoric that seemed to play by none of the rules that had come down to us from a tradition of rhetoric that had been practiced by the reigning nations of the Western World for over 2000 years. And then there is the distinctive rhetoric of the Oriental world…. But those are rhetorics that we still have to study and analyze and codify.—Edward P. J. Corbett, Classical Rhetoric for the Modern Student (1990), viii.