bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Chain Architecture on the Dynamics of Copolymers in a Homopolymer Matrix: Lattice Monte Carlo Simulations using the Bond‐Fluctuation Model
Authors: Kamath Sudesh Y. , Dadmun Mark D. 
Published: October 2005

AbstractSummary: The effects of copolymer sequence distribution on the dynamics of a copolymer in a homopolymer matrix are studied using computer simulations within the framework of the bond‐fluctuation model on blends containing low concentrations (10%) of copolymers dispersed in a homopolymer matrix. The sequence distribution of the two copolymer components was changed while maintaining the overall copolymer composition at 50/50. Our results indicate that copolymers with disordered sequence distributions exhibit dynamics that are faster than that of a homopolymer melt, while those with ordered sequence distributions exhibit a tendency to form aggregates that lead to slower dynamics as well as phase separation. Analysis of the structure suggests that copolymers with an alternating sequence distribution form large aggregates that are short‐lived, while diblocks form permanent micelle‐like structures. Analysis of the local composition around a copolymer molecule indicates that aggregation between copolymer chains has a direct impact on the local composition. This in turn has a significant impact on system dynamics. Our results indicate that the dynamics of random, random‐blocky, and alternating copolymers are nearly identical and are faster than that of a homopolymer melt. However, alternating copolymers form aggregates and hence are not uniformly distributed throughout the matrix phase. Thus, alternating copolymers are at a disadvantage in their ability to be effective compatibilizers. From a dynamic perspective, copolymers with random and random‐blocky copolymers seem to be ideal compatibilizers since they are distributed uniformly throughout the system and move rapidly through the matrix phase.Snapshots of aggregates of alternating copolymer chains. Dark and bright spheres represent A and B monomers, respectively.magnified imageSnapshots of aggregates of alternating copolymer chains. Dark and bright spheres represent A and B monomers, respectively.
Medieval big cat remains from the Royal Menagerie at the Tower of London
Authors: O'Regan H. , Turner A. , Sabin R. 
Published: October 2005

AbstractBig cats have been regarded as a symbol of power in different cultures throughout history. Here we present a study of the only known big cat remains from the Royal Menagerie at the Tower of London. They were excavated in 1937 but have not previously been published. Our radiocarbon dating has established that they range in date from the 13th–17th centuries, making them the earliest post‐Pleistocene big cat remains in Britain. We provide a description of the specimens–two lion skulls, a fragmentary leopard, plus 19 dog crania–and discuss the partially occluded foramen magnum of one of the lions. This anomaly has also been noted in captive and unprovenanced cat skulls from the early 20th century, indicating that it is a condition with a long history. We discuss the remains, the history of the menagerie, and the uses of the animals, in the light of our knowledge of conditions for captive animals at the time. Zooarchaeological studies such as these may also provide insights for modern conservation of zoo animals, and this aspect of the work is also considered. Copyright © 2005 John Wiley & Sons, Ltd.
Limitations with the response evaluation criteria in solid tumors (RECIST) guidance in disseminated pediatric malignancy
Authors: Barnacle A.M. , McHugh Kieran 
Published: October 2005

AbstractBackgroundResponse evaluation criteria in solid tumors (RECIST) guidelines were published in 2000 to evaluate response to treatment in solid tumors. These have sought to unify response assessment, and the new guidelines extend beyond lesion assessment to address modern imaging strategies. The RECIST guidelines, however, become complex and problematic when used to evaluate metastatic disease.MethodsTen consecutive oncology cases representative of tumors common to our pediatric practice were selected. All cases were evaluated at initial presentation and follow‐up. The RECIST criteria were retrospectively applied in each case. A standardized evaluation form was used.ResultsThe age range of the patients included in the study was 1 month to 16 years, with a mean age of 3.9 years. A range of tumor responses was identified: partial response (n = 6), stable disease (n = 2), and progressive disease (n = 2). Two of these responses were likely incorrect. Tumor bulk was underestimated in the axial plane, many lesions were either calcified and unmeasurable, or despite being well‐defined were too small to be measurable under the strict RECIST guidance.ConclusionIn highlighting specific problems with disseminated pediatric tumors, we emphasize the pressing need for debate regarding the application of RECIST in pediatric oncology and encourage the development of a pediatric radiology oncology group to collaborate in future modifications of the RECIST guidance. Pediatr Blood Cancer. © 2005 Wiley‐Liss, Inc.
Mn(III) oxidation of peptide polymers of elastin sequences: synthesis, kinetics and mechanistic study
Authors: Abiraj K. , Baba A. Ramesha , Srinivasa G. R. , Gowda D. Channe 
Published: October 2005

AbstractProtein based‐polymers comprised of Ala‐, Val‐ and Ile‐containing tetrapeptide repeating sequences of elastin were synthesized based on the increasing order of hydrophobicity and subjected to metal‐catalyzed oxidation to identify the amino acid residues, which are sensitive to oxidation. These polytetrapeptides (PTP) were oxidized using Mn(OAc)3 at 25°C and the kinetics of the reaction were monitored spectrophotometrically at λmax = 400 nm. A first‐order rate dependence on the substrate concentration [PTP] and [Mn(III)] and an inverse order dependence on [H+] has been observed. Further, the rate is independent of [Mn(OAc)2]. The effect of the dielectric constant on the rate was studied by varying the percentage of AcOH. Activation parameters were evaluated using Arrhenius and Eyring plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving [Mn(OAc)4]− is proposed. It is noteworthy that the rate of oxidation of poly(GGIP) was higher than those of poly(GGVP) and poly(GGAP). This may be due to their increased hydrophobicity. The overall order of rate of oxidation of PTP is poly(GGIP) > poly(GGVP) > poly(GGAP). Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and metathesis activity of ruthenium dimethylvinyl carbene complexes
Authors: Lehman Stephen E. , Wagener Kenneth B. , Akvan Shahab 
Published: October 2005

AbstractTwo new dimethylvinyl carbene complexes, RuCl2(SIMes)(PPh3)CHCHC(CH3)2 and RuCl2(SIMes)(3BP)2CHCHC(CH3)2, were synthesized from RuCl2(PCp3)2CHCHC(CH3)2. Complex RuCl2(SIMes)(3BP)2CHCHC(CH3)2 does not suffer from the problem of incomplete initiation that has been observed for the other dimethylvinyl carbene complexes, as witnessed by complete and rapid reaction with ethyl vinyl ether. Acyclic diene metathesis (ADMET) polymerization of 1,9‐decadiene with these complexes was found to give polymers with chemical and thermal properties similar to those obtained with Schrock's molybdenum catalyst. These complexes are also catalysts for ring‐opening metathesis polymerization. The parent complex RuCl2(SIMes)(PCp3)CHCHC(CH3)2 was found to give polyoctenamer with high initial heats of fusion, suggesting a dependence of the “as formed” crystallinity of the polymer on the rate of the ROMP reaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6134–6145, 2005
Preparation, characterization, and thermal properties of alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,3‐bis(ethylene)permethyloligosiloxanylene]s
Authors: Lee Nam S. , Gädda Thomas M. , Weber William P. 
Published: October 2005

Abstractalt‐Copoly[1,9‐decaphenylpentasiloxanylene/1,3‐bis(ethylene)tetramethyldisiloxanylene], alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,5‐bis(ethylene)hexamethyltrisiloxanylene], alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,7‐bis(ethylene)octamethyltetrasiloxanylene], and alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,9‐bis(ethylene)decamethylpentasiloxanylene] were synthesized by Pt‐catalyzed hydrosilylation reactions of 1,9 divinyldecaphenylpentasiloxanes with a series of oligodimethylsiloxanes. The molecular weights of these copolymers were determined by gel permeation chromatography. Their glass‐transition temperatures (Tg's) were obtained by differential scanning calorimetry. The thermal stabilities of the copolymers were measured by thermogravimetric analysis. The structures of the copolymers were verified by 1H, 13C, and 29Si NMR as well as IR and UV spectroscopy. The copolymers displayed high thermal stabilities and a single Tg, indicating that phase separation between the two short blocks did not occur. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6146–6152, 2005
Thermoresponsive copolymers of methacrylic acid and poly(ethylene glycol) methyl ether methacrylate
Authors: Jones Janevieve A. , Novo Noel , Flagler Kendra , Pagnucco Christina D. , Carew Steve , Cheong Charles , Kong Xiang Z. , Burke Nicholas A. D. , Stöver Harald D. H. 
Published: October 2005

AbstractCopolymers of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) were prepared and their cloud points in aqueous solution were studied as a function of comonomer ratio, solution pH, and presence of hydrophobic comonomers. Under acidic conditions, the cloud point falls below 0 °C for copolymers with between 25% to 60% ether content, because of the formation of hydrophobic H‐bonded ether–acid complexes. The cloud point also decreases with solution pH. For equivalent ether to acid ratios, the cloud point decreases with decreasing PEG chain length, because of the presence of a larger number of hydrophobic methyl and methacrylate groups. Similarly, the cloud point decreases upon incorporation of hydrophobic comonomers such as butyl, lauryl, or glycidyl methacrylates. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6095–6104, 2005
Matrix‐assisted laser desorption/ionization time‐of‐flight analysis of the copolymerization reaction of an expanding monomer with a diepoxide
Authors: Miller Matthew D. , Holder Andrew J. , Guthrie Jill R. , Pinzino Charles S. , Chappelow Cecil C. , Eick J. David 
Published: October 2005

AbstractIn search of a composite with low stress and low shrinkage properties, this study includes matrix‐assisted laser desorption/ionization time‐of‐flight analysis of the photoinitiated cationic polymerization between an expanding monomer [1,5,7,11‐tetraoxaspiro[5.5]undecane (TOSU)] and a diepoxide [bisphenol A diglycidyl ether (BADGE)]. Past studies using NMR and differential scanning calorimetry analyses concluded copolymerization indirectly on the basis of deviations from homopolymer product data. This is the first study to provide direct evidence of copolymerization between these species. Unlike previous research, this study enables the identification of the TOSU homopolymer and the absence of the BADGE homopolymer, suggesting initial cationic activation of TOSU. In addition to peaks that correspond to the presumed mechanism for six‐membered TOSU polymerization, many peaks have a net gain or loss of cyclic carbonate in support of a new polymerization mechanism participating in the reaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5962–5970, 2005
Copolymers of 2,5‐bis[(4‐methoxyphenyl) oxycarbonyl]styrene with n‐butyl acrylate: Design, synthesis, and characterization
Authors: Gao Long‐Cheng , Pan Qi‐Wei , Yi Yi , Fan Xing‐He , Chen Xiao‐Fang , Zhou Qi‐Feng 
Published: October 2005

AbstractA series of rod–coil diblock copolymers, consisting of poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} as a rigid segment and poly(n‐butyl acrylate) as a flexible part, were successfully prepared through two inverse procedures by atom transfer radical polymerization. The copolymers were characterized by 1H NMR and gel permeation chromatography and had high molecular weights and relatively narrow polydispersities (polydispersity index < 1.20). All the block copolymers synthesized had two distinct glass‐transition temperatures according to differential scanning calorimetry. A polarizing optical microscopy investigation demonstrated the liquid crystallinity of the diblock copolymers. The self‐assembly behaviors in dilute solutions was studied by transmission electron microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5935–5943, 2005
A tetrapeptide‐based method for polyproline II‐type secondary structure prediction
Authors: Vlasov Peter K. , Vlasova Anna V. , Tumanyan Vladimir G. , Esipova Natalia G. 
Published: October 2005

AbstractWe describe a new method for polyproline II‐type (PPII) secondary structure prediction based on tetrapeptide conformation properties using data obtained from all globular proteins in the Protein Data Bank (PDB). This is the first method for PPII prediction with a relatively high level of accuracy (∼60%). Our method uses only frequencies of different conformations among oligopeptides without any additional parameters. We also attempted to predict α‐helices and β‐strands using the same approach. We find that the application of our method reveals interrelation between sequence and structure even for very short oligopeptides (tetrapeptides). Proteins 2005. © 2005 Wiley‐Liss, Inc.
Mutagenesis at Pro309 of single‐chain urokinase‐type plasminogen activator alters its catalytic properties
Authors: Sun Ziyong , Liu Jian‐Ning 
Published: October 2005

AbstractThe charge of Lys300(c143) located within a flexible loop(297–313) of sc‐uPA has been identified as an important determinant for its high intrinsic activity. Mutations affecting the flexibility of the loop also modulate the intrinsic activity. Glu‐plasminogen activation by sc‐uPA is strongly promoted by fibrin fragment E but not fibrin fragment D‐dimer, whereas plasminogen activation by t‐PA is strongly promoted by fragment D‐dimer but not fragment E. To further investigate the effect of conformation changes in the flexible loop on catalytic properties of sc‐uPA, cassette mutations at Pro309(c152) were made and characterized. It was found that the activation of Pro309(c152) mutants by Lys‐plasmin was only moderately affected. In contrast, the intrinsic and two‐chain activities of Pro309(c152) mutants against S2444 were both significantly decreased. The two‐chain activities of these mutants against Glu‐plasminogen were also reduced in a range of 1.1‐ to 127‐fold. The mutations of Pro309(c152) to Trp/Phe and Arg/Asp more significantly affected both intrinsic and two‐chain activities, while only a moderate decrease in activity was found with mutations to Ala/Ser/Thr. In contrast to wild‐type sc‐uPA, plasminogen activation by Pro309(c152) mutants was found to be promoted by both fibrin fragment E and D‐dimer. In the presence of 2.0 μM D‐dimer, plasminogen activation by mutant Pro309(c152)→ His was promoted by 22‐fold, while only 2.0‐fold promotion was found with mutant Pro309(c152) → Gly. In conclusion, these findings demonstrated that conformation changes in the flexible loop of sc‐uPA not only affect its intrinsic and two‐chain activity, but also extend its promotion of plasminogen activation by fragment E to D‐dimer. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Integrating risk‐based inspection into risk management plans
Authors: Conley M. 
Published: October 2005

AbstractUsing risk as a metric for decisions, the right inspection can be applied at the right time. Risk‐based inspection is an approach for integrating risk metrics for both inspection‐type activities (such as preventative maintenance) and design‐type activities (such as safety systems to decrease risk).Risk management plans are being developed for ammonia storage facilities to:

ensure the safety of employees, the public, and the environment
aid management in the decision‐making process to determine which activities achieve the most cost‐effective form of risk reduction
allow prioritization of even very different activities under the umbrella of good risk management practices.

© 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Simulation calculations of surface segregation for Au–Cu alloys using an analytic embedded atom model
Authors: Bangwei Zhang , Taglauer Edmund , Xiaolin Shu , Wangyu Hu , Huiqiu Deng 
Published: October 2005

AbstractThe key problem for applying the Monte Carlo (MC) method to segregation lies in the selection of an appropriate energy model for the simulations. Zhang et al. proposed a modified analytic embedded atomic method (MAEAM), which has been applied to a variety of fundamental problems in metals and alloys. We used this MAEAM and MC method for the simulations of segregation of AuCu and Au3Cu alloys. For the (100) surface, the calculations show that Au is enriched in the 1st layer (70 at% for AuCu, 99 at% for Au3Cu), while Cu is enriched in the 2nd layer (50–62 at% for AuCu, 35–48 at% for Au3Cu). The composition profiles are generally oscillating. For the (111) surface, we also found Au to be enriched in the 1st layer. However, Cu is not enriched in the 2nd layer, it reaches the bulk composition from 2nd to 4th layer. Au increases from 92 to 97 at% and 99 to 100 at% for Au3Cu(111) and (100), respectively, when the temperature varies from 1000 to 200 K, which is basically in agreement with the measurements for Au3Cu(100) by Taglauer et al. However, the Au concentration does not change for the AuCu alloy in the same temperature range. We also calculate the segregation energy, the simulation results agree qualitatively with the experimental data available. Our results demonstrate that the MAEAM model provides an effective means for simulating the segregation of alloys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of the temperature‐dependent resistivity of La1–xTexMnO3
Authors: Guan Dong‐yi , Zhou Qing‐li , Jin Kui‐juan , Tan Guo‐tai , Chen Zheng‐hao , Lu Hui‐bin , Cheng Bo‐lin , Zhou Yue‐liang , He Meng , Han Peng , Yang Guo‐zhen 
Published: October 2005

AbstractThe resistivity ρ of La1–xTexMnO3 (x = 0.1, 0.14) is studied using a random resistor network, based on phase separation between ferromagnetic (FM) and paramagnetic (PM) domains. By considering the irregular shape of the domains, a revised method, which is used to find the shortest paths across the sample, leads to a good agreement between the simulated results and experiment data. Moreover, it is found that FM components increase with Te doping, leading to a reduction of the resistivity and a shift of the transition temperature. This method is proved to be valid and the phase separation scenario is shown theoretically to be good enough in describing the electrical conductivity of the doped manganese perovskites. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Substantial addition of PbO and liquid phase conversion during the final processing of (Bi,Pb)‐2223 thick film on Ag substrate and their influence on the microstructure and transport properties
Authors: Azzouz F. Ben , M'chirgui A. , Ben Salem M. 
Published: October 2005

Abstract(Bi,Pb)‐2223 polycrystalline samples were made by introducing into the precursor powders various weight fractions of PbO during the final sintering cycle of a multi‐step preparation process. The influence of PbO addition on the melting temperature, high‐TC ((Bi,Pb)‐2223) phase formation, microstructure and transport property of samples was studied by DTA, XRD, SEM/EDX and electrical measurements. The results showed that the substantial addition of PbO up to 10 wt% promotes likely the stability and the abundance of the transient liquid phase during sintering, which in turn improved the grain growth an connectivity of (Bi,Pb)‐2223 phase, hence resulted in the improvement of transport current JC. The ultimate value of critical current density at 77 K in the self‐field is found to be 1080 A/cm2 in (Bi,Pb)‐2223 thick films on Ag substrate samples. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of gloss from rough surface parameters
Authors: Simonsen Ingve , Larsen Åge G. , Andreassen Erik , Ommundsen Espen , Nord‐Varhaug Katrin 
Published: October 2005

AbstractGloss is a quantity used in the optical industry to quantify and categorize materials according to how well they scatter light specularly. With the aid of phase perturbation theory, we derive an approximate expression for this quantity for a one‐dimensional randomly rough surface. It is demonstrated that gloss depends in an exponential way on two dimensionless quantities that are associated with the surface randomness: the root‐mean‐square roughness times the perpendicular momentum transfer for the specular direction, and a correlation function dependent factor times a lateral momentum variable associated with the collection angle. Rigorous Monte Carlo simulations are used to access the quality of this approximation, and good agreement is observed over large regions of parameter space. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Developments in the n‐electron valence state perturbation theory
Authors: Angeli Celestino , Borini Stefano , Cavallini Alex , Cestari Mirko , Cimiraglia Renzo , Ferrighi Lara , Sparta Manuel 
Published: October 2005

AbstractA short summary of the n‐electron valence state perturbation theory (NEVPT) is provided, and the defects inherent in cases of quasi‐degeneration are underscored. A new version of the theory, called QD‐NEVPT, based on quasi‐degenerate perturbation theory, is presented. The new theory introduces an effective interaction among the zero‐order wave functions and overcomes the difficulties of state‐specific NEVPT. An application concerning the interaction among the π → π* and Rydberg singlets of formaldehyde is presented. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Lower semicontinuity and existence of minimizers in incremental finite‐strain elastoplasticity
Authors: Mielke A. , Müller S. 
Published: October 2005

AbstractWe study incremental problems in geometrically nonlinear elastoplasticity. Using the multiplicative decomposition Dφ= FelFpl we consider general energy functionals of the formℐ(φ, Fpl) = ∫ΩU(x, DφF‐1pl, Fpl, 𝒢(Fpl)) dx‐<ℓ, φ>,which occur as the sum of the stored energy and the dissipation in one time step. Here 𝒢(Fpl) is the dislocation tensor which takes the form ${1\over {\rm det} F_{\rm pl}}$ curl3(Fpl),Fpl T in dimension d = 3.Imposing the usual constraint det Fpl ≡ 1 and suitable growth and polyconvexity conditions on U we show that the minimum of ℐ is attained in the natural Sobolev spaces. Moreover, we are able to treat multiple time steps by controlling the stored and dissipated energies. We also address the relation of the incremental problem to the time‐continuous energetic formulation of elastoplasticity.