bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Polyurethane Formulations Containing Diols Obtained via Glycolysis of Poly(ethylene terephthalate) (PET) by Oligoesters Diols through a Reactive Extrusion Process
Authors: Colomines Gaël , Rivas Florian , Lacoste Marie‐Laure , Robin Jean‐Jacques 
Published: July 2005

AbstractSummary:The glycolysis of PET by oligoester diols in the presence of zinc acetate was carried out in two successive twin‐screw extruders with total residence times of 4 min and without solvent. These new glycolysates were analyzed and used in polyurethane formulation with a commercial polyol. The reactivity of these formulations was studied. The mechanical properties, thermal and swelling behavior of these polyurethanes were investigated. Mechanical properties are improved with the addition of glycolysate. The thermal behavior is not modified with the addition of glycolysate. The swelling behavior of the material depends on the solvent nature. The addition of glycolysate allows a decrease in material swelling in chloroform but increases this swelling in acetone.magnified image
Gamma Ray Irradiation‐Initiated Copolymerization of a Binary Casting System Involving DPBMIn and Vinylpyrrolidone
Authors: Liu Feng , Wang Zhen , Lü Changli , Gao Lianxun , Ding Mengxian 
Published: July 2005

AbstractSummary: When initiated by gamma ray irradiation, a series of homogenous binary casting systems composed of bismaleimide oligomer DPBMIn with different chain length and reactive solvent vinylpyrrolidone were capable of copolymerization via radical mechanism to form copolymer resins with crosslinked network. Postcuring was performed by thermal treatment subsequent to gamma ray irradiation. The influences of irradiation dose, postcure, DPBMIn content, and chain length of DPBMIn on mechanical properties, water uptake, and thermal property of copolymer resins were investigated in details. Fracture morphologies of copolymer resins based on different DPBMIn were studied by SEM.SEM images of the copolymer resins.magnified imageSEM images of the copolymer resins.
Synthesis of Fluorinated Hyperbranched Polymers and Their Use as Additives in Cationic Photopolymerization
Authors: Sangermano Marco , Di Gianni Anna , Bongiovanni Roberta , Priola Aldo , Voit Brigitte , Pospiech Doris , Appelhans Dietmar 
Published: July 2005

AbstractSummary: A fluorine containing hyperbranched polymer was synthesized by modifying an aromatic‐aliphatic hyperbranched polyester with a semifluorinated alcohol via a Mitsunobu reaction and was subsequently used as an additive in cationic photopolymerization of an epoxy resin. The remaining OH groups of the fluorinated hyperbranched polymer interact with the polymeric carbocation through a chain‐transfer mechanism inducing an increase in the final epoxy conversion. The fluorinated HBP induces modification of bulk and surface properties, with an increase in Tg and surface hydrophobicity already reached at very low concentration. The HBFP additive can, therefore, protect the coatings from aggressive solvents, increases hardness, and allows the preparation of a low energy surface coating.Synthesis of fluorinated hyperbranched polyester.magnified imageSynthesis of fluorinated hyperbranched polyester.
Asymptotic properties of digit sequences of random numbers
Authors: Stadje Wolfgang 
Published: July 2005

AbstractWe consider several aspects of the relationship between a [0, 1]‐valued random variableXand the random sequence of digits given by itsm‐ary expansion. We present results for three cases: (a) independent and identically distributed digit sequences; (b) random variablesXwith smooth densities; (c) stationary digit sequences. In the case of i.i.d. an integral limit thorem is proved which applies for example to relative frequencies, yielding asymptotic moment identities. We deal with occurrence probabilities of digit groups in the case thatXhas an analytic Lebesgue density. In the case of stationary digits we determine the distribution ofXin terms of their transition functions. We study an associated [0, 1]‐valued Markov chain, in particular its ergodicity, and give conditions for the existence of stationary digit sequences with prespecified transition functions. It is shown that all probability measures induced on [0, 1] by such sequences are purely singular except for the uniform distribution. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Rapid Eco‐Friendly Synthesis of Poly(butylene succinate) by a Direct Polyesterification under Microwave Irradiation
Authors: Velmathi Sivan , Nagahata Ritsuko , Sugiyama Jun‐ichi , Takeuchi Kazuhiko 
Published: July 2005

AbstractSummary: A rapid and eco‐friendly synthesis of poly(butylene succinate) (PBS) using microwaves was developed in the presence of 1,3‐dichloro‐1,1,3,3‐tetrabutyldistannoxane as catalyst. To determine the optimum conditions, the effect of catalyst concentration, bulk vs. solution polymerization, reaction time, temperature, and stoichiometry of the monomers were studied. Based on the optimum conditions, PBS with a weight‐average molecular weight of 2.35 × 104 was obtained in a short time of 20 min.Synthesis of poly(butylene succinate) under microwave irradiation.magnified imageSynthesis of poly(butylene succinate) under microwave irradiation.
Novel C60‐Anchored Two‐Armed Poly(tert‐butyl acrylate): Synthesis and Characterization
Authors: Chu Chih‐Chien , Wang Leeyih , Ho Tong‐Ing 
Published: July 2005

AbstractSummary: A multistep synthetic procedure for preparing novel C60‐anchored two‐armed poly(tert‐butyl acrylate) was developed. First, two‐armed poly(tert‐butyl acrylate) bearing a malonate ester core with well‐controlled molecular weight was synthesized through atom transfer radical polymerization. The effective Bingel reaction between C60 and the well‐defined polymer was then carried out to yield C60‐anchored polymer. GPC, 1H NMR, and UV‐vis spectroscopy indicated that the C60‐anchored polymer was a monosubstituted and ‘closed’ 6,6‐ring‐bridged methanofullerene derivative.Schematic of a novel C60‐anchored two‐armed polymer.magnified imageSchematic of a novel C60‐anchored two‐armed polymer.
Macromolecular Recognition by Polymer‐Carrying Cyclodextrins: Interaction of a Polymer Bearing Cyclodextrin Moieties with Poly(acrylamide)s Bearing Aromatic Side Chains
Authors: Hashidzume Akihito , Ito Fumitaka , Tomatsu Itsuro , Harada Akira 
Published: July 2005

AbstractSummary: The interaction of a polymer bearing β‐cyclodextrin moieties (β‐CD polymer) with poly(acrylamide)s bearing aromatic side chains was investigated by viscometry to study the effect of collectivity (i.e., interactions at multi‐sites) in macromolecular recognition. The formation of inclusion complexes at multi‐sites caused a large difference in the size of interpolymer aggregates, even though the difference in association constants for complexation of native β‐CD with guest moieties was not very much large.Conceptual illustration for interpolymer aggregates of β‐CD polymer with poly(acrylamide)s bearing naphthyl groups substituted on the (a) 1‐ and (b) 2‐positions (see Scheme 1).magnified imageConceptual illustration for interpolymer aggregates of β‐CD polymer with poly(acrylamide)s bearing naphthyl groups substituted on the (a) 1‐ and (b) 2‐positions (see Scheme 1).
Radical approaches to probe protein structure, folding, and interactions by mass spectrometry
Authors: Maleknia Simin D. , Downard Kevin M. 
Published: July 2005

AbstractI.Introduction388II.Case for Radicals389III.Radiation and Discharge Radical Sources390IV.Reaction Products: Nature of Amino Acid Modifications391V.Protein Integrity Versus Damage392VI.Reaction Kinetics and Protein Structure Elucidation394VII.Protein Folding: Equilibrium and Time‐Resolved Studies395VIII.Protein Complexes and Assemblies397IX.Conclusions398Acknowledgments399References399This review describes mass spectrometry‐based strategies and investigations to determine protein structure, folding dynamics, and protein‐protein interactions in solution through the use of radical reagents. The radicals are generated in high flux within microseconds from synchrotron radiation and discharge sources, and react with proteins on time scales that are less than those often attributed to structural reorganization and folding. The oxygen‐based radicals generated in aqueous solution react with proteins to effect limited oxidation at specific amino acids throughout the sequence of the protein. The extent of oxidation at these residue markers is highly influenced by the accessibility of the reaction site to the bulk solvent. The extent of oxidation allows protection levels to be measured based on the degree to which a reaction occurs. A map of a protein's three‐dimensional structure is subsequently assembled as in a footprinting experiment. Protein solutions that contain various concentrations of substrates that either promote or disrupt dynamic structural transitions can be investigated to facilitate site‐specific equilibrium and time‐resolved studies of protein folding. The radical‐based strategies can also be employed in the study of protein–protein interactions to provide a new avenue for investigating protein complexes and assemblies with high structural resolution. The urea‐induced unfolding of apomyoglobin and the binding of gelsolin to actin are among the systems presented to illustrate the approach. © 2002 Wiley Periodicals, Inc., Mass Spec Rev 20:388–401, 2001; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.10013
Polyolefin Macroradical Properties: A Semiempirical Quantum Chemistry Study
Authors: Shyichuk Alexander , Cysewski Piotr 
Published: July 2005

AbstractSummary: Semiempirical quantum chemistry simulations have been used to estimate the properties of mid‐chain alkyl radicals of ethylene, propylene and styrene oligomers depending on the chain length. The values of spin density and charge on the radical site proved to be almost unchanged for oligomer radicals having from 2 to 11 repeated units. Bond strength parameters of bonds neighboring the radical site demonstrate stable values starting from pentamers. The reliable inference is that the electron structure of polyethylene, poly(propylene) and polystyrene (PS) macroradicals may be simulated by means of relatively short oligomers. The obtained data indicate clearly that the polystyrene tertiary alkyl radical has noticeably decreased values of both spin and charge onto the radical site as well as very decreased strength of β‐bonds. For that reason the PS tert‐alkyl radical is estimated as that having decreased activity and increased susceptibility to chain scission. The most probable cause is delocalization of the free electron onto the neighboring aromatic ring.Spin density distribution in tertiary radical of polystyrene.magnified imageSpin density distribution in tertiary radical of polystyrene.
Usefulness of electrodiagnostic techniques in the evaluation of suspected tarsal tunnel syndrome: An evidence‐based review
Authors: Patel Atul T. , Gaines Kenneth , Malamut Richard , Park Tracy A. , Toro David R. Del , Holland Neil 
Published: July 2005

AbstractThis evidence‐based review was performed to evaluate the utility of nerve conduction studies (NCSs) and needle electromyography (EMG) in the diagnosis of tibial neuropathy at the ankle (tarsal tunnel syndrome, TTS). A total of 317 articles on TTS were identified that were published in English from 1965 through April 2002, from the National Library of Medicine MEDLINE database. All articles were reviewed on the basis of six selection criteria. The results of this search revealed that four articles met five or more criteria. All four articles examined the use of electrodiagnostic (EDX) techniques for the evaluation of patients with clinically suspected TTS, and were included in this practice parameter. Each of these four studies was considered to meet Class III level of evidence. NCSs were abnormal in some patients with suspected TTS. Sensory NCSs were more likely to be abnormal than motor NCSs but the actual sensitivity and specificity could not be determined. The sensitivity of needle EMG abnormalities could not be determined. NCSs may be useful for confirming the diagnosis of tibial neuropathy at the ankle, recommendation Level C. Well‐designed studies are needed to evaluate more definitively EDX techniques in TTS. Muscle Nerve, 2005
Benign pineal cysts in children with bilateral retinoblastoma: A new variant of trilateral retinoblastoma?
Authors: Beck Popovic Maja , Balmer Aubin , Maeder Philippe , Braganca Teresa , Munier Francis L. 
Published: July 2005

AbstractPurposePatients with hereditary retinoblastoma (Rb) develop in 4%–8% a malignant midline tumor called trilateral Rb (TRb). We report in this study on benign pineal cysts observed in patients investigated for TRb.Patients and MethodsBetween September 1990 and December 2001, 172 patients were screened for TRb. Ninty‐five had bilateral, 77 unilateral disease. The median age at diagnosis of Rb was 7 months (range 1–26). Treatment included enucleation, local treatment with cryotherapy or photocoagulation, first‐line chemotherapy (CT), thermo‐chemotherapy (TCT), Ruthenium plaque, and, rarely, external beam radiation (EBR).ResultsTRb was found in 5/95 patients (5.3%) with bilateral disease. Interestingly, five other patients (5.3%) presented a pineal cyst on magnetic resonance imaging (MRI). No cysts were recorded in the 77 patients with unilateral disease. This difference was statistically significant (P < 0.05). The median age at diagnosis of the pineal cyst was 26 months (range 16–80), much younger than reported in literature for healthy children. Four of five patients with TRb died of the disease, while all the patients with pineal cysts remained stable and asymptomatic during a median follow‐up of 41 months (range 37–54).ConclusionsThis report describes benign cystic lesions of the pineal gland in patients with hereditary Rb, suggesting a benign variant of TRb. Underlying possible pathogenetic mechanisms are discussed. © 2005 Wiley‐Liss, Inc.
Syntheses of 12‐arm star polymers and star diblock copolymers by nitroxide‐mediated radical polymerization using dendritic dodecafunctional macroinitiators
Authors: Miura Yozo , Dote Hiroyuki 
Published: July 2005

AbstractDendritic multifunctional macroinitiators having 12 TEMPO‐based alkoxyamines were prepared by the reaction of a benzyl alcohol having 4 TEMPO‐based alkoxyamines with 1,3,5‐tris[(4‐chlorocarbonyl)phenyl]benzene and 1,3,5‐tris(4‐isocyanatophenyl)benzene. Using the dodecafunctional macroinitiators, TEMPO‐mediated radical polymerizations of styrene (St) were carried out at 120 °C, and 12‐arm star polymers (star‐12) with narrow polydispersities of Mw/Mn = 1.06–1.26 were obtained. To evaluate the livingness for the TEMPO‐mediated radical polymerizations of St, hydrolysis of the ester bonds of the 12‐arm star polymers and subsequent SEC measurements were carried out. Furthermore, using star‐12 as the macroinitiator, TEMPO‐mediated radical polymerization of 4‐vinylpyridine (4‐VP) was carried out, and well‐defined poly(St)‐b‐poly(4‐VP) 12‐arm star diblock copolymers with Mw/Mn = 1.18–1.19 were obtained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3689–3700, 2005
Modification of surface properties of polyethylene by perfluoropolyether blending
Authors: Puukilainen Esa , Pakkanen Tapani A. 
Published: July 2005

AbstractThe preparation of a stabile blend from thermoplastic polymer and lubricating additive was studied with high density polyethylene (HDPE) and perfluoropolyether (PFPE). PFPE was melt blended within HDPE by injection molding. The chemical composition of the mixtures, the relative amount of PFPE on the surface, and the nature of the surface were studied by three surface sensitive methods: attenuated total reflectance infrared (ATR‐IR) spectroscopy, secondary ion mass spectroscopy (SIMS), and contact angle (CA) measurement. All the blends exhibited improved hydrophobicity. CA and SIMS gave a maximum response when about 2.0 wt % PFPE was added, whereas ATR‐IR spectroscopy gave maximum response for an addition of about 3.0 wt %. No changes in surface properties were observed when samples were reanalyzed about 1–4 months after preparation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2252–2258, 2005
Influence of entanglements on glass transition of atactic polystyrene
Authors: Rong Weiren , Fan Zhongyong , Yu Yin , Bu Haishan , Wang Michael 
Published: July 2005

AbstractFreeze‐dried samples were prepared from dilute solutions of atactic polystyrene (a‐Ps) in benzene in a concentration range of 1 × 10−1 to 2 × 10−5 g/mL, and their glass transition temperatures (Tg) were determined by differential scanning calorimetry. It was found that below a critical concentration (C), the Tg of samples decreases linearly with decreasing logarithmic concentration of solutions. The freeze‐dried samples were annealed at a constant temperature for various times or at various temperatures for the same period of time. The Tg of samples prepared from solutions of concentration below C was observed to shift to higher temperature with increasing annealing temperature or annealing time, finally approaching that of the bulk sample. Fourier transform infrared (FTIR) spectra of the freeze‐dried samples were determined and were compared with the bulk sample. Significant changes in line width and absorption intensity were observed in the spectra of the freeze‐dried samples, indicating that the packing of segments is in a more dilatant state. During annealing, the packing of segments in the samples gradually approaches that of the bulk sample, diminishing the differences in FTIR spectra between the freeze‐dried sample and the bulk sample. The experimental observations are discussed, and it is assumed that intrachain and interchain entanglements may play an important role in glass transition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2243–2251, 2005
Plasma Spraying of Capillary Porous Coatings: Experiments, Modeling, and Biomedical Applications
Authors: Kalita Vassili I. , Gnedovets Alexey G. 
Published: July 2005

AbstractSummary: A novel technology of plasma spraying three‐dimensional capillary porous (3DCP) titanium coatings with principally new structures consisting of ridges and cavities has been developed. The surface area of the 3DCP coatings increases in direct proportion to the increase of the thickness of the deposited coating. The process of fabrication of the 3DCP coatings is performed under a sharp incidence angle of the plasma spray on the substrate. This method of spraying is based on the effect of shadow zones arising behind the particles already deposited to the substrate. The influence of the spray angle on the coatings porosity, roughness, and structure was investigated both in experiments using the methods of optical microscopy, SEM, image analysis, and porosimetry, and also by means of three‐dimensional numerical simulations. The value of the porosity of the 3DCP coatings reaches ∼50%, and the widths of the ridges and cavities may be regulated over a wide range, from 5 up to 2 700 µm. It was found that in order to achieve the highest strength characteristics of the porous coating, the ridges must be built‐up of splats with a maximum contact area between them. Low porosity (2–10%) of the internal volume of the ridges allows high values of adhesion and cohesion to be reached. The technology of plasma deposition of porous coatings was applied as a method to improve the functional characteristics of intrabone implants widely used in medicine. Enhanced mechanical parameters and high values of porosity and surface area of titanium 3DCP coatings are favorable for bone tissue growth in and fastening of its connection with an implant. The volume available for bone ingrowth into fabricated titanium 3DCP coatings appeared to be six times greater than the corresponding values for conventional plasma‐sprayed coatings.Computer images of the coating deposited at an off‐normal spray angle and the corresponding pore network.magnified imageComputer images of the coating deposited at an off‐normal spray angle and the corresponding pore network.
The anti‐HIV cyanovirin‐N domain is evolutionarily conserved and occurs as a protein module in eukaryotes
Authors: Percudani Riccardo , Montanini Barbara , Ottonello Simone 
Published: July 2005

AbstractA novel protein family homologous to the sugar‐binding antiviral protein cyanovirin‐N (CVN) is described. CVN, an 11‐kDa protein that, by binding to the high‐mannose moiety of certain viral surface glycoproteins, blocks virus entry into target cells, has thus far been identified only in the cyanobacterium Nostoc ellipsosporum. Here we show that CVN belongs to a protein family identified by analysis of transcript sequences deriving from a gene expression profiling study conducted in the truffle Tuber borchii. Members of this family (named CyanoVirin‐N
Homology) are found in filamentous ascomycetes and in the fern Ceratopteris richardii. As revealed by 3D structure‐based searches, all CVNH proteins have a predicted fold that matches the so far unique fold of the cyanobacterial polypeptide. The CVNH domain is a versatile protein module. In ferns and cyanobacteria it is found in secretory proteins. In filamentous ascomycetes it is found in nonsecretory monodomain proteins as well as part of multidomain proteins bearing functionally related modules such as the peptidoglycan and chitin‐binding domain LysM. Transcript abundance data further indicate that the expression of different CVNH forms is modulated in response to nutrient availability. These findings have implications for the understanding of protein–oligosaccharide interaction in fungi and plants, and provide candidate polypeptides to be tested and exploited as antiviral agents. Proteins 2005. © 2005 Wiley‐Liss, Inc.
LNG vapor cloud exclusion zones for spills into impoundments
Authors: Havens Jerry , Spicer Tom 
Published: July 2005

AbstractLNG spills on land are most likely to happen in dike/impoundment areas, introducing the need to consider effects of dike/impoundment walls on vapor holdup and dispersion. The DEGADIS and FEM3A models are approved for determination of vapor cloud exclusion zones in 49 CFR 193, but DEGADIS is limited to prediction of dispersion from area sources over flat, obstacle‐free terrain and is therefore not directly applicable to spills in dike/impoundment areas. However, FEM3A, which is a computational fluid dynamics (CFD) model, is directly applicable. Before FEM3A was approved, ad hoc methods were widely used to determine input conditions for DEGADIS to estimate dispersion downwind of a dike system for such releases. Vapor holdup and mixing with air in a dike system have been studied in wind tunnel and field experiments, and the fallacy of using an overly simplistic estimation of the time and rate of vapor cloud overflow has been demonstrated. In some cases, these ad hoc methods have resulted in exclusion zone determinations that do not provide for public safety as intended by 49 CFR 193. This paper summarizes the current state of knowledge about this important vapor dispersion scenario, including key experimental data that address the question. Applications of FEM3A to determine exclusion zones for a hypothetical spill within a typical dike/tank configuration, as well as a shortcut use of FEM3A to describe vapor overflow from the same impoundment for use as input information for DEGADIS simulation of the dispersion downwind from the dike, are illustrated. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005