bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallcarbene mit niedriger Oxidationsstufe als Initiatoren für Olefinmetathesen und verwandte Reaktionen
Authors: Katz Thomas J. 
Published: March 2005

AbstractVor 24 Jahren wurden Experimente mit Tantalcarbenen durchgeführt, aus deren Ergebnissen die häufig zitierte Hypothese abgeleitet wurde, dass Metalle (außer Ruthenium) ihre maximale Oxidationsstufe aufweisen müssen, damit ihre Carbenderivate Olefinmetathesen auslösen können. Diese Hypothese berechtigt zu der Annahme, dass nur Molybdän‐ und Wolframcarbene mit hoher Oxidationsstufe wirksame Initiatoren sind. Sie legt auch nahe, dass die schon früher als Initiatoren für Olefinmetathesen und verwandte Reaktionen entdeckten Fischer‐Wolframcarbene oxidiert werden müssen, bevor sie wirksam werden können. Die neueren Initiatoren sind als “wohldefiniert”, die älteren als “undefiniert” bezeichnet worden. Entspricht das den Fakten?
Ligating behavior and metal uptake of N‐sulphonylpolyamine chelating resins anchored on polystyrene‐divinylbenzene beads
Authors: Jeragh Bakir J. A. , Elassar Abdel‐Zaher A. , El‐Dissouky Ali 
Published: March 2005

AbstractAmberlite XAD‐2 has been functionalized by coupling through –SO2‐with ethylenediamine, propylenediamine, and diethylenetriamine to give the corresponding polyamine chelating resins I–III. The solid metallopolymer complexes of the synthesized chelating resins with Cu2+, Zn2+, Cd2+, and Pb2+ were synthesized. The polyamine derivatives and their metal complexes were characterized by elemental analysis, spectral (IR, UV/V, and ESR), and magnetic studies. The batch equilibrium method was utilized for using the chelating polyamines for the removal of Cu+2, Zn+2, Cd+2, and Pb+2 ions from aqueous solutions at different pH values and different shaking times at room temperature. The selective extraction of Cu+2 from a mixture of the four metal ions and the metal capacities of the chelating resins were evaluated using atomic absorption spectroscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1839–1846, 2005
Graft copolymerization of sodium salt of partially carboxymethylated guar gum with methyl methacrylate: An examination of the reaction variables
Authors: Trivedi J. H. , Kalia Kiran , Patel N. K. , Trivedi H. C. 
Published: March 2005

AbstractThe graft copolymerization of methyl methacrylate (MMA) onto sodium salt of partially carboxymethylated guar gum (Na‐PCMGG; degree of substitution = 0.497) with ceric ammonium nitrate as a redox initiator in an aqueous medium was studied. The optimized reaction conditions affording the maximum percentage of grafting of MMA onto Na‐PCMGG were determined through the variation of the concentrations of nitric acid, ceric ammonium nitrate, MMA, and Na‐PCMGG and of the temperature and time. The effects of these parameters on the grafting yields and the rates of polymerization, graft copolymerization, and homopolymerization were also studied, and the results were examined. The graft copolymer sample was characterized with IR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1855–1864, 2005
Formation of polymer nanocomposites with various organoclays
Authors: Kim Younghoon , White James L. 
Published: March 2005

AbstractThe role of the type of organic modifier used with montmorillonite (MMT) on the formation of polymer/clay nanocomposites in the melt compounding process was investigated. Various organoclays including primary [12‐aminolauric acid (12ALA)], secondary [dioctylamine (DOA)], tertiary [trioctylamine (TOA)], and two commercial quaternary (Cloisite 30B and 20A) MMTs were melt compounded with carefully selected polymers including polypropylene, polystyrene, styrene–acrylonitrile copolymer, poly(methyl methacrylate), poly(vinylidene fluoride), and acrylonitrile–butadiene copolymer (NBR). X‐ray diffraction and transmission electron microscopy characterizations confirmed that the two quaternary ammonium organoclay (Cloisite 30B and 20A) have superior compatibility compared to the primary (12ALA), secondary (DOA), and tertiary (TOA) ammonium organoclay. DOA and TOA can form polymer/clay nanocomposites only with the most polar polymer (NBR). Cloisite Na+ and 12ALA can not form nanocomposite with any polymers. The large organic surface area of the quaternary ammonium organoclay could be the reason of the best compatibility with polar polymers. It is estimated that long alkyl ammonium chains of organic modifier can spread over the clay surface more effectively than short alkyl chains. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1888–1896, 2005
Synthesis, characterization, and applications of polyvinylpyrrolidone/SiO2 hybrid materials
Authors: Hsiao C. N. , Huang K. S. 
Published: March 2005

AbstractThis research discusses the properties of hybrid materials formed by polyvinylpyrrolidone (PVP) and tetraethoxysilane (TEOS) of different weight ratios, by the sol–gel process, to evaluate the feasibility of its application to process‐dyed nylon fabrics. After using equipment including FTIR, 13C‐NMR, and SEM, it was shown that PVP and SiO2 are connected by hydrogen bonds, further showing the existence of special functional groups and the porous structure in hybrid materials. The pore size of the hybrid materials, specific volume of pores, and the specific surface area increased with increasing weight ratio of TEOS. In addition, the TGA testing results showed that the thermoresistance of hybrid materials can be improved. The color of the treated fabrics darkened if dyed nylon fabrics were treated by hybrid materials. When using metal complex acid dye for certain fabrics, when hybrid materials were used in finishing, there was significant improvement to the fabric's hygroscopicity and its colorfastness against chlorine. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1936–1942, 2005
One‐component epoxy resin with imine as water‐initiated latent hardener: Improvement of the mechanical and adhesive properties by the addition of methacrylate copolymer
Authors: Suzuki Kentarou , Sugita Yuko , Sanda Fumio , Endo Takeshi 
Published: March 2005

AbstractThe effect of addition of methacrylate polymer into a one‐component epoxy resin, containing Epikote 828 and diimine as a water‐initiated hardener, was examined. Although the cured epoxy resin in the presence of methyl methacrylate–butyl acrylate (MMA–BA) copolymer was very brittle, the resin containing MMA–BA–[γ‐(methacryloxy)propyl]trimethoxysilane (TMSMA) copolymer showed good mechanical and adhesive properties. The adhesive strength of the cured epoxy resin containing MMA–BA–TMSMA copolymer was much higher than that without its polymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1943–1949, 2005
Modeling of semibatch styrene suspension polymerization processes
Authors: Lenzi Marcelo Kaminski , Cunningham Michael F. , Lima Enrique Luis , Pinto José Carlos 
Published: March 2005

AbstractWe developed a mathematical model to describe the behavior of semibatch styrene suspension polymerization processes, where the constituents of a typical emulsion polymerization process are added into the reaction vessel during the course of a typical suspension reaction. This technique was recently described for the production of core–shell polymer particles. The model assumes that the nucleated emulsion particles can agglomerate with the sticky and much bigger suspension particles and that the agglomeration rate constant is a function of the internal states of the suspended droplets. The proposed model presented good agreement with experimental conversion, average molecular weight, and molecular weight distribution data. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1950–1967, 2005
Novel biodegradable amino acid containing anhydride oligomers for orthopedic applications
Authors: Xie Dong , Chung Ildoo , Puckett Aaron D. , Mays Jimmy W. 
Published: March 2005

AbstractNovel synthetic biodegradable methacrylated anhydride oligomers (MAOs) based on methacrylated alaninyl maleamic acid (MAMA) and methacrylated aminocaproyl maleamic acid (MACMA) were synthesized and characterized. Injectable and in situ crosslinkable polymer networks were formulated by the copolymerization of MAOs with triethylene glycol dimethacrylate (TEGDMA). Furthermore, composites composed of MAOs, TEGDMA, and β‐tricalcium phosphate were prepared. The networks and composites were initiated by photopolymerization and redox polymerization, respectively. The initial compressive strength (CS) and diametral tensile strength (DTS) of these materials were determined and used to evaluate the effects of the MAO/TEGDMA ratios on the degradation behavior of the materials. The MAMA‐based composites had initial DTS values of 5.7–17.1 MPa and CS values of 30.7–114.2 MPa. The MACMA‐based composites had initial DTS values of 2.8–20.8 MPa and CS values of 19.1–119.5 MPa. During the course of degradation, the neat polymer resins lost 97 and 87% of their initial CS values after 6 months with 50/50 MAMA/TEGDMA and MACMA/TEGDMA ratios, respectively. The composite with a 25/75 MACMA/TEGDMA ratio showed a significant increase in CS after an initial decrease for 7 days and then lost 57% of its initial CS value after 3 months. The composite composed of 100% methacrylated anhydride oligomer (MAOs) showed complete degradation after 21 days. The degrees of conversion of the neat resins were 60–77%. Both the neat resins and the composites had low polymerization shrinkage ranging from 3.8 to 5.6%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1979–1984, 2005
Adsorption of certain amino acids onto crosslinked diethylaminoethyl dextran microbeads
Authors: Tayfur Muhittin , Güner Ali 
Published: March 2005

AbstractThe adsorption dynamism of certain amino acids [alanine (Ala), serine (Ser), lysine (Lys), proline (Pro), and aspartic acid (Asp)] on crosslinked diethylaminoethyl (DEAE) dextran microbeads was investigated with electronic spectroscopy in aqueous solutions. Among the selected amino acids, Ala‐Pro and Ser‐Lys showed similar adsorption dynamism, but Asp showed the strongest tendency for adsorption. The interaction dynamism of Asp with crosslinked DEAE dextran microbeads was studied to determine the mechanism of this adsorption. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1985–1991, 2005
The clustering power of low frequency words in academic Webs
Authors: Price Liz , Thelwall Mike 
Published: March 2005

AbstractThe value of low frequency words for subject‐based academic Web site clustering is assessed. A new technique is introduced to compare the relative clustering power of different vocabularies. The technique is designed for word frequency tests in large document clustering exercises. Results for the Australian and New Zealand academic Web spaces indicate that low frequency words are useful for clustering academic Web sites along subject lines; removing low frequency words results in sites becoming, on average, less dissimilar to sites from other subjects.
Fluorene and phenanthrene uptake by Pseudomonas putida ATCC 17514: Kinetics and physiological aspects
Authors: Rodrigues Ana C. , Wuertz Stefan , Brito António G. , Melo Luís F. 
Published: March 2005

AbstractPseudomonas putida ATCC 17514 was used as a model strain to investigate the characteristics of bacterial growth in the presence of solid fluorene and phenanthrene. Despite the lower water‐solubility of phenanthrene, P. putida degraded this polycyclic aromatic hydrocarbon (PAH) at a maximum observed rate of 1.4 ± 0.1 mg L−1 h−1, higher than the apparent degradation rate of fluorene, 0.8 ± 0.07 mg L−1 h−1. The role of physiological processes on the biodegradation of these PAHs was analyzed and two different uptake strategies were identified. Zeta potential measurements revealed that phenanthrene‐grown cells were slightly more negatively charged (–57.5 ± 4.7 mV) than fluorene‐grown cells (–51.6 ± 4.9 mV), but much more negatively charged than glucose‐grown cells (–26.8 ± 3.3 mV), suggesting that the PAH substrate induced modifications on the physical properties of bacterial surfaces. Furthermore, protein‐to‐exopolysaccharide ratios detected during bacterial growth on phenanthrene were typical of biofilms developed under physicochemical stress conditions, caused by the presence of sparingly water‐soluble chemicals as the sole carbon and energy source for growth, the maximum value for TP/EPS during growth on phenanthrene (1.9) being lower than the one obtained with fluorene (5.5). Finally, confocal laser microscopy observations using a gfp‐labeled derivative strain revealed that, in the presence of phenanthrene, P. putida::gfp cells formed a biofilm on accessible crystal surfaces, whereas in the presence of fluorene the strain grew randomly between the crystal clusters. The results showed that P. putida was able to overcome the lower aqueous solubility of phenanthrene by adhering to the solid PAH throughout the production of extracellular polymeric substances, thus promoting the availability and uptake of such a hydrophobic compound. © 2005 Wiley Periodicals, Inc.
Biomass characteristics and membrane aeration: Toward a better understanding of membrane fouling in submerged membrane bioreactors (MBRs)
Authors: Germain Eve , Stephenson Tom , Pearce Pete 
Published: March 2005

AbstractFouling in submerged membrane bioreactors (MBRs) was studied under different operating conditions and with varying biomass characteristics. Fouling rates were determined using a flux‐step method for seven biomass conditions with mixed liquor solids concentrations ranging from 4.3 to 13.5 g.l−1, six permeate fluxes (5.5, 11.0, 16.5, 22.0, 27.5, and 33.0 l.m−2.h−1), and three membrane airflow velocities (0.07, 0.10, and 0.13 m.s−1). Statistical analysis was used to specify the degree of influence of each of the biomass characteristics (solids concentration, dewaterability, viscosity, particle size distribution, concentrations of protein and carbohydrate in the soluble microbial products, SMP, and extracellular polymer substances, EPS), the permeate flux and the membrane aeration velocity on the membrane fouling rate. Among all these variables, only the permeate flux, the solids concentration (correlated to the viscosity and the dewaterability), the carbohydrate concentration in the EPS, and the membrane aeration velocity were found to affect the fouling rate. The permeate flux had the greatest effect. A transitional permeate flux was observed between 16.5 and 33 l.m−2.h−1, below which no significant fouling was observed regardless of the biomass characteristics, the permeate flux, and the membrane aeration velocity. © 2005 Wiley Periodicals, Inc.
Temperature‐triggered purification of antibodies
Authors: Kim Jae‐Young , Mulchandani Ashok , Chen Wilfred 
Published: March 2005

AbstractIn this article the unique capability of elastin‐like protein (ELP) to reversibly precipitate was combined with the high affinity and specificity of antibody‐binding domains such as Protein G, Protein L, or Protein LG as a general method for antibody purification that combines in a unique manner the simplicity and robustness of temperature‐triggered precipitation with the selectivity of affinity interactions. In a single precipitation step, antibodies derived from different sources (animal sera or hybridoma cell cultures) were selectively recovered by a simple temperature trigger. Due to the versatility of the binding ligands toward different classes of antibodies, we believe that this technology will be useful as an economical, highly efficient, and universal platform for the purification of antibodies. © 2005 Wiley Periodicals, Inc.
Measuring social influence of a senior midwife on decision‐making in maternity care: an experimental study
Authors: Hollins Martin Caroline , Bull Peter 
Published: March 2005

AbstractThe document Changing Childbirth produced by the Department of Health (1993) requests provision of more choice, continuity and control for women during pregnancy and childbirth. In this context this study considers whether midwives'decisions are influenced by a senior midwife. A simple, valid and reliable scale—the Social Influence Scale for Midwifery (SIS‐M)—was devised to measure and score midwives' private anonymous responses to 10 clinical decisions. The SIS‐M was initially administered as a self‐completed postal survey by 209 midwives. Following a 9‐month time gap, a stratified sample of 60 (20 E, F, G grade midwives) were invited for interview in which a senior midwife attempted to influence SIS‐M responses in a conformist direction. Overall, a 3 × 2 (E, F, G grade midwives x private and interview SIS‐M scores) analysis of variance (ANOVA) revealed midwives were significantly more conformist when influenced by a senior midwife, in comparison to private anonymous responses. No significant interaction between groups was found. These findings indicate that there is influence of a senior midwife on clinical decisions that should be woman‐centred, according to Changing Childbirth (1993). The implication is that this influence may remove choice from women. Copyright © 2005 John Wiley & Sons, Ltd.
Lomustine (chloroethylnitrosourea [CCNU]), ifosfamide, bleomycin, vincristine, and cisplatin (CIBO‐P) is an effective regimen for patients with poor prognostic refractory or multiple disease recurrent aggressive non‐Hodgkin lymphoma
Authors: Musolino Antonino , Perrone Maria Antonietta , Michiara Maria , Delnevo Daniela , Franciosi Vittorio , Di Blasio Beatrice , Ceci Guido , Camisa Roberta , Ardizzoni Andrea , Cocconi Giorgio 
Published: March 2005

AbstractBACKGROUNDThe current study was designed to assess the activity and safety of a novel combination therapy for patients with recurrent or refractory aggressive non‐Hodgkin lymphoma (NHL).METHODSForty‐three consecutive patients with recurrent or refractory aggressive NHL were treated with lomustine (chloroethylnitrosourea [CCNU]; 60 mg/m2on Day 1), ifosfamide (1.5 g/m2on Days 1, 2 and 21, 22), bleomycin (5 mg/m2on Days 1, 5 and 21, 25), vincristine (1.4 mg/m2on Days 1, 8 and 21, 28), and cisplatin (25 mg/m2on Days 3, 4, 5 and 23, 24, 25), every 42 days (CIBO‐P regimen).RESULTSThirty‐nine patients (91%) were evaluable for response. The median patient age was 63 years. Thirty‐five percent of the patients had received ≥ 2 lines of previous chemotherapy and 40% had elevated lactate dehydrogenase levels at the time of treatment initiation. The overall objective response rate was 77% (95% confidence interval [95% CI], 63–90%), including 19 (49%) complete (CR) and 11 (28%) partial responses. CIBO‐P induced responses in primary refractory disease and in patients treated for second or subsequent disease recurrences. A CR with previous therapy was the most important factor associated with a significantly higher CR rate. The median duration of response was 6 months (95% CI, 4.4–7.7 months) and the median survival duration was 10.7 months (95% CI, 5.9–18.1 months). Five patients (11.6%) remained disease free for ≥ 24 months. By multivariate analysis, a CR with previous therapy and average dose intensity of CIBO‐P drugs were independent prognostic factors for time‐to‐treatment failure, whereas a CR with previous therapy and serum lactate dehydrogenase were independent predictors for survival. Myelosuppression was the most frequent serious complication of this regimen. However, none of the patients had hemorrhage with thrombocytopenia, and only 2 patients (5%) had febrile neutropenia.CONCLUSIONSIn the current study, CIBO‐P was a novel, highly active, and safe combination therapy for patients with refractory disease with a poor prognosis or for patients with multiply recurrent aggressive NHL. Cancer 2005. © 2005 American Cancer Society.
Surface‐Enhanced Raman Scattering of p‐Aminothiophenol on a Au(core)/Cu(shell) Nanoparticle Assembly
Authors: Cao Linyou , Diao Peng , Tong Lianming , Zhu Tao , Liu Zhongfan 
Published: March 2005

AbstractSurface‐enhanced Raman scattering (SERS) of p‐aminothiophenol (PATP) molecules adsorbed onto assemblies of Au(core)/Cu(shell) nanoparticles is reported. We compare it with the SERS spectrum of PATP adsorbed onto gold nanoparticles: both the absolute and relative scattered intensities of various bands in the two spectra are very different. The difference in relative intensity can be ascribed to chemical effects; the chemical enhancement ratio of the two substrates is ≈3–5. A theoretical analysis based on a charge‐transfer model is carried out, which yields a consistent result and shows that the difference in chemical enhancement is mainly due to the state densities and Fermi levels of the substrates. The difference in absolute intensity originates from electromagnetic (EM) enhancement. EM enhancement of Au(core)/Cu(shell) nanoparticles is unlike that of single‐component gold or copper SERS‐active substrates. The core/shell particle size for optimal enhancement is about 20 nm in the case of a 632.8 nm incident laser (the size ratio of the core and shell layers is about 0.6).
Numerical solution of the Boltzmann equation by time relaxed Monte Carlo (TRMC) methods
Authors: Pareschi Lorenzo , Trazzi Stefano 
Published: March 2005

AbstractA new family of Monte Carlo schemes has been recently introduced for the numerical solution of the Boltzmann equation of rarefied gas dynamics (SIAM J. Sci. Comput. 2001; 23:1253–1273). After a splitting of the equation the time discretization of the collision step is obtained from the Wild sum expansion of the solution by replacing high‐order terms in the expansion with the equilibrium Maxwellian distribution. The corresponding time relaxed Monte Carlo (TRMC) schemes allow the use of time steps larger than those required by direct simulation Monte Carlo (DSMC) and guarantee consistency in the fluid‐limit with the compressible Euler equations. Conservation of mass, momentum, and energy are also preserved by the schemes. Applications to a two‐dimensional gas dynamic flow around an obstacle are presented which show the improvement in terms of computational efficiency of TRMC schemes over standard DSMC for regimes close to the fluid‐limit. Copyright © 2005 John Wiley & Sons, Ltd.
Nonlinearity in the Fed's monetary policy rule
Authors: Kim Dong Heon , Osborn Denise R. , Sensier Marianne 
Published: March 2005

AbstractThis paper investigates the nature of nonlinearities in the monetary policy rule of the US Federal Reserve (Fed) using the flexible approach to nonlinear inference. We find that while there is significant evidence of nonlinearity for the period to 1979, there is little such evidence for the subsequent period. Possible asymmetries in the Fed's reactions to inflation deviations from target and the output gap in the 1960s and 1970s may tell part of the story, but do not capture the entire nature of the nonlinearity. The inclusion of the interaction between inflation deviations and the output gap, as recently proposed, appears to characterize the nonlinear policy rule more adequately. Copyright © 2005 John Wiley & Sons, Ltd.
Nonparametric bounds on the returns to language skills
Authors: González Libertad 
Published: March 2005

AbstractThis paper applies the theoretical literature on nonparametric bounds on treatment effects to the estimation of how limited English proficiency (LEP) affects wages and employment opportunities for Hispanic workers in the United States. I analyse the identifying power of several weak assumptions on treatment response and selection, and stress the interactions between LEP and education, occupation and immigration status. I show that the combination of two weak but credible assumptions provides informative upper bounds on the returns to language skills for certain subgroups of the population. Adding age at arrival as a monotone instrumental variable also provides informative lower bounds. Copyright © 2005 John Wiley & Sons, Ltd.