bluuebunny/crossref_metadata_2025 huggingface dataset:
A general approach to fuzzy concepts
Authors: Popescu Andrei
Published: April 2004

The paper proposes a flexible way to build concepts within fuzzy logic and set theory. The framework is general enough to capture some important particular cases, with their own independent interpretations, like “antitone” or “isotone” concepts constructed from fuzzy binary relations, but also to allow the two universes (of objects and attributes) to be equipped each with its own truth structure. Perhaps the most important feature of our approach is that we do not commit ourselves to any kind of logical connector, covering thus the case of a possibly non‐commutative conjunction too. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constructive complements of unions of two closed sets
Authors: Bridges Douglas S.
Published: April 2004

It is well known that in Bishop‐style constructive mathematics, the closure of the union of two subsets of ℝ is ‘not’ the union of their closures. The dual situation, involving the complement of the closure of the union, is investigated constructively, using completeness of the ambient space in order to avoid any application of Markov's Principle. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fragments of Martin's Maximum in generic extensions
Authors: König Bernhard , Yoshinobu Yasuo
Published: April 2004

We show that large fragments of MM, e. g. the tree property and stationary reflection, are preserved by strongly (ω1 + 1)‐game‐closed forcings. PFA can be destroyed by a strongly (ω1 + 1)‐game‐closed forcing but not by an ω2‐closed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Processing Additives on Adhesive Properties of Surface‐Modified Low‐Density Polyethylene
Authors: Novák Igor , Florián Štěpán
Published: April 2004

Summary: The paper deals with the surface and adhesive properties of low‐density polyethylene modified by corona discharge, which appear during the long‐term hydrophobic recovery of the modified polymer. The study was aimed at the change in polarity during aging of low‐density polyethylene modified by corona discharge reducing the surface free energy, its polar component and the mechanical work of adhesion. During the long‐term hydrophobization of low‐density polyethylene the main decrease of the surface properties appeared within the first 30 d after modification. In the course of further aging the hydrophobic recovery of the polymer proceeded more slowly. It has been found that the value of the surface and adhesive properties of low‐density polyethylene after modification with corona discharge as well as the dynamics of their decrease during the aging is to a great extent dependent on the presence of the processing additives in the polymer.

Mechanical work of adhesion of LDPE modified by corona discharge to poly(vinyl acetate) during hydrophobic recovery: a) additive‐free LDPE, b) LDPE with additives.

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Mechanical work of adhesion of LDPE modified by corona discharge to poly(vinyl acetate) during hydrophobic recovery: a) additive‐free LDPE, b) LDPE with additives.
The Relationship between Microstructure and Properties in PP/Rubber Powder/nano‐CaCO3 Ternary Blends
Authors: Su Xinqing , Hua Youqing , Qiao Jinliang , Liu Yiqun , Zhang Xiaohong , Gao Jianming , Song Zhihai , Huang Fan , Zhang Manli
Published: April 2004

Summary: A new kind of rubber powder with “salami” structure (RPS) was prepared by spray drying the mixture of styrene‐butadiene rubber latex and nano‐CaCO3 slurry. It was found that RPS is an effective toughener with synergistic toughening effect on poly(propylene) (PP). The Izod impact strength of PP/RPS blend is not only higher than that of PP/rubber powder or PP/nano‐CaCO3 blends, but also higher than that of a PP/rubber powder/CaCO3 blend. TEM images show that the microstructure of the PP/RPS blend is an “island‐sea” structure with “salami” structure in RPS, in which nano‐CaCO3 particles are embedded in styrene‐butadiene rubber particles. The relationship between properties and microstructure has been studied by using TEM, SEM, DSC, etc.

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Nitroxide‐Controlled Grafting by an Insertion Mechanism using a Polymerizable N‐Oxyl
Authors: Appelt Mathias , Schmidt‐Naake Gudrun
Published: April 2004

Summary: The polymerizable nitroxide 4‐acryloyloxy‐2,2,6,6‐tetramethylpiperidine‐N‐oxyl (AOTEMPO) was utilized in a two step polymerization to prepare alkoxyamine‐functionalized backbone polymers. These backbones were then used as initiators for stable free‐radical graft polymerizations in bulk at 125 °C. The products were cleaved into their linear components by reaction with L‐(+)‐ascorbic acid allowing a reproducible analysis of the molecular weights. The influences of the backbone concentration and the graft density on the polymerization were investigated. Graft polymers purely consisting of styrene were produced as well as polymers with a backbone based on 2‐ethoxyethyl acrylate (EOEA). In addition a graft polymer with block copolymer side chains was prepared by extending a preformed graft polymer. In all cases the controlled course of the reaction was confirmed by the linear increase of the molecular weights over conversion and the low polydispersities of the products.

Structure of an extended graft copolymer.

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Structure of an extended graft copolymer.
Hydrogenation of Styrene‐Butadiene Rubber Catalyzed by Ru(CHCHPh)Cl(CO)(PCy3)2
Authors: Pan Qinmin , Rempel Garry L.
Published: April 2004

Summary: The hydrogenation of a copolymer of styrene and butadiene (SBR) catalyzed by Ru(CHCHPh)Cl(CO)(PCy3)2 was experimentally investigated within the temperature range of 120–160 °C, at P of 300–1 200 psi, and a catalyst concentration of 10–78 × 10−6 M. Special attention was paid to minimizing the catalyst metal residue and crosslinking in the product. The results indicated that high‐quality hydrogenated SBR was achieved without crosslinking and the metal residue was less than 7 ppm without a post‐treatment.

IR spectra of the styrene–butadiene rubber before (a) and after (b) hydrogenation with the Ru(CHCHPh)Cl(CO)(PCy3)2 catalyst were observed as reported here. The disappearance of all characteristic absorbencies of CC (724, 910, 967, and 994 cm−1) suggests nearly quantitative hydrogenation of the CC bonds.

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IR spectra of the styrene–butadiene rubber before (a) and after (b) hydrogenation with the Ru(CHCHPh)Cl(CO)(PCy3)2 catalyst were observed as reported here. The disappearance of all characteristic absorbencies of CC (724, 910, 967, and 994 cm−1) suggests nearly quantitative hydrogenation of the CC bonds.
Negative Electrorheological Effect of Silicone Gels Containing Barium Titanate
Authors: Mitsumata Tetsu , Sugitani Kousuke
Published: April 2004

Summary: We observed the negative electrorheological phenomenon on swollen silicone gels containing barium titanate. Contrary, no negative electrorheological effect was observed in unswollen silicone gels containing barium titanate and silicon gels without barium titanate. The change in storage modulus increased with increasing DC electric field strength. The effects of frequency, degree of swelling, and the field strength have been investigated.

Electric‐field dependence of the change in storage modulus at f = 0.1 Hz for swollen silicone/BaTiO3 gels with varying CAT content; (○): CAT 0.1, (□): CAT 0.2, (⋄): CAT 0.3, (×): SG.

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Electric‐field dependence of the change in storage modulus at f = 0.1 Hz for swollen silicone/BaTiO3 gels with varying CAT content; (○): CAT 0.1, (□): CAT 0.2, (⋄): CAT 0.3, (×): SG.
Synthesis and Characterization of a Novel, Mesoporous Organosilica with Additional Cyclodextrin‐Based Micropores
Authors: Liu Chunqing , Wang Jinfeng , Economy James
Published: April 2004

Summary: A novel mesoporous organosilica with additional cyclodextrin‐based micropores has been synthesized from tetraethoxysilane (TEOS) and cyclodextrin‐based silane monomer precursors and triblock PEO‐PPO‐PEO (poly(ethylene oxide)‐poly(propylene oxide)‐ poly(ethylene oxide)) copolymer P123 as the structure‐directing template with the aid of sodium chloride and the supramolecular assembly of cyclodextrins with P123.

The synthesis of CD‐Si‐2%.

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The synthesis of CD‐Si‐2%.
Synthesis and Cyclohexene Oxide/Carbon Dioxide Copolymerizations of Zinc Acetate Complexes Bearing Bidentate Pyridine‐Alkoxide Ligands
Authors: Kim Il , Kim Sang Mook , Ha Chang‐Sik , Park Dae‐Won
Published: April 2004

Summary: The reaction of 2‐lithio‐6‐methylpyridine or 2‐lithiopyridine and the appropriate diaryl ketone followed by hydrolysis yields 6‐Me‐pyCAr2OH pyridine alcohols or pyCAr2OH pyridine alcohols. The reactions of zinc acetate with 1 equiv. of the lithiated products of the ligands proceed rapidly to afford LiOAc salt and mono‐ligand complexes (6‐Me‐pyCAr2O)Zn(OAc) and (pyCAr2O)Zn(OAc), respectively, in high yield. The copolymerizations of carbon dioxide with cyclohexene oxide were investigated. The (6‐Me‐pyCAr2O)Zn(OAc) showed moderate yield and CO2 incorporation. The [6‐Me‐pyC(4‐Cl‐C6H4)2O]Zn(OAc) complex gave large polymers with high proportions of carbonate linkage (>60%) and narrow polydispersity, indicating single active sites.

The monoligated Zn complexes synthesized and used here as catalysts for the copolymerization of cyclohexene oxide and carbon dioxide.

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The monoligated Zn complexes synthesized and used here as catalysts for the copolymerization of cyclohexene oxide and carbon dioxide.
Diffusion‐Controlled Particle Growth and its Effects on Nucleation in Stirred Emulsion Polymerisation Reactors
Authors: Sajjadi Shahriar
Published: April 2004

Summary: Particle formation and growth in the batch emulsion homo‐polymerisation of styrene and methyl methacrylate monomers under diffusion‐controlled conditions were studied. The polymerisations started with two stratified layers of a monomer and water containing an initiator and a surfactant, with the water layer being gently stirred. Because of limitations in monomer transport, the rate of particle growth was substantially reduced and as a result a large number of polymer particles formed.

Schematic presentation of the highly diffusion‐controlled polymerisation.

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Schematic presentation of the highly diffusion‐controlled polymerisation.
Polymer‐Bound, Amphiphilic Hoveyda‐Grubbs‐Type Catalyst for Ring‐Closing Metathesis in Water
Authors: Zarka M. Tobias , Nuyken Oskar , Weberskirch Ralf
Published: April 2004

Summary: We report on the synthesis of a new amphiphilic, polymer‐bound variant of the Hoveyda‐Grubbs catalyst via the coupling reaction of a carboxylic acid‐functionalized poly(2‐oxazoline) block copolymer with 2‐isopropoxy‐5‐hydroxystyrene and subsequent reaction of the resulting macroligand with a second generation Grubbs catalyst. For the benchmark, the substrate diethyl diallylmalonate was studied in the ring‐closing metathesis (RCM) reaction and a turn‐over number (TON) of up to 390 in water was achieved. To the best of our knowledge, this is the highest value for any aqueous RCM reaction to date. For the first time, recycling of a ruthenium initiator in an aqueous RCM reaction has been successful to some extent. In addition, the micellar conditions accelerate the conversion of the hydrophobic diene and at the same time stabilize the active alkylidene species, although competing decomposition of the catalyst in water still impairs the catalyst performance. Residual ruthenium content was determined to be below 1 ppm in the product suggesting a very low leaching of the polymeric catalyst system.

Simplified chemical structure of the amphiphilic, polymer‐bound Grubbs‐Hoveyda catalyst.

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Simplified chemical structure of the amphiphilic, polymer‐bound Grubbs‐Hoveyda catalyst.
Selective human enterovirus and rhinovirus inhibitors: An overview of capsid‐binding and protease‐inhibiting molecules
Authors: Shih Shin‐Ru , Chen Shu‐Jen , Hakimelahi Gholam Hossein , Liu Hsing‐Jang , Tseng Chen‐Tso , Shia Kak‐Shan
Published: April 2004

The absence of effective vaccines for most viral infections highlights an urgent necessity for the design and development of effective antiviral drugs. Due to the advancement in virology since the late 1980s, several key events in the viral life cycle have been well delineated and a number of molecular targets have been validated, culminating in the emergence of many new antiviral drugs in recent years. Inhibitors against enteroviruses and rhinoviruses, responsible for about half of the human common colds, are currently under active investigation. Agents targeted at either viral protein 1 (VP1), a relatively conserved capsid structure mediating viral adsorption/uncoating process, or 3C protease, which is highly conserved among different serotypes and essential for viral replication, are of great potential to become antipicornavirus drugs. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 4, 449–474, 2004
DNA minor groove binders as potential antitumor and antimicrobial agents
Authors: Baraldi Pier Giovanni , Bovero Andrea , Fruttarolo Francesca , Preti Delia , Tabrizi Mojgan Aghazadeh , Pavani Maria Giovanna , Romagnoli Romeo
Published: April 2004

DNA minor groove binders constitute an important class of derivatives in anticancer therapy. Some of these compounds form noncovalent complexes with DNA (e.g., distamycin A, Hoechst 33258, and pentamidine) while others DNA‐binding compounds (such as CC‐1065) cause cleavages in the DNA backbone. In this article, we have reviewed the minor groove binders currently in preclinical evaluation in the last years. Diarylamidines such as DAPI, berenil, and pentamidine; bis‐benzimidazoles such as Hoechst 33258; ecteinascidins, pyrrololo [2,1‐c]‐[1,4]‐benzodiazepines (PBDs), CC‐1065, and distamycins are the classes discussed in this review article. A special section has been dedicated to hybrid molecules resulted by the combination of two minor groove binders, especially for derivatives of naturally occurring antitumor agents, such as anthramycin or the alkylating unit of the antibiotic CC‐1065, and distamycin frames. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 4, 475–528, 2004
On the evolution of thin viscous jets: filament formation
Authors: Fontelos Marco A.
Published: April 2004

In this paper, we have studied the evolution of thin fluid jets, paying special attention on the limit of very large viscosity. Local well‐posedness of the one‐dimensional system describing this evolution as well as the existence of break‐up (at least as t → ∞) under quite general conditions is proved. In addition, we have proved the well‐known experimental fact that in the limits of very large viscosities the solutions develop very long and thin filaments previous to break‐up and a complete detailed description of their structure is given. Copyright © 2004 John Wiley & Sons, Ltd.
Different short‐term modulation of cortical motor output to distal and proximal upper‐limb muscles during painful sensory nerve stimulation
Authors: Urban P. P. , Solinski M. , Best C. , Rolke R. , Hopf H. C. , Dieterich M.
Published: April 2004

The pattern of upper‐limb muscle activation following painful stimulation has not been clarified in detail. We investigated the short‐term inhibitory and excitatory effects of painful electrical digital stimulation on the motoneuron pools of distal and proximal upper‐limb muscles. Transcranial magnetic stimulation (TMS) was used as test stimulus, and painful digital nerve stimulation as conditioning stimulus for motor evoked potential (MEP) recordings over the abductor digiti minimi (ADM), abductor pollicis brevis (APB), biceps brachii (BB), and deltoid muscles. Inhibition of the conditioned MEP response was most prominent in the distal muscles, whereas BB and deltoid muscles were only weakly inhibited. The mean MEP response over APB decreased with painful cutaneous stimuli, showing maximum inhibition (by 82%) at interstimulus intervals (ISIs) of 50 ms. Inhibition in the ADM was maximal (49%) but less pronounced at an ISI of 40 ms. The BB and deltoid muscles showed inhibition by 25% and 29%, respectively. Significant facilitation was present in BB and deltoid muscles by 43% and 41% at an ISI of 100 ms, but not in the smaller hand muscles. The observed pattern of upper‐limb muscle activation corresponds to the protective withdrawal reflex and the neuronal basis of the observed short‐term modulation of motor activity is compatible with a spinal or brainstem pathway. Muscle Nerve 29: 663–669, 2004
Continuous myofiber remodeling in uninjured extraocular myofibers: Myonuclear turnover and evidence for apoptosis
Authors: McLoon Linda K. , Rowe Jocelyn , Wirtschafter Jonathan , McCormick Kathleen M.
Published: April 2004

Unlike normal mature limb skeletal muscles, in which satellite cells are quiescent unless the muscle is injured, satellite cells in mammalian adult extraocular muscles (EOM) are chronically activated. This is evidenced by hepatocyte growth factor, the myogenic regulatory factor, Pax‐7, and the cell‐cycle marker, Ki‐67, localized to the satellite cell position using serial sections and the positional markers laminin and dystrophin. Bromodeoxyuridine (brdU) labeling combined with dystrophin immunostaining showed brdU‐positive myonuclei, presumably the result of fusion of activated satellite cells into existing myofibers. One new myonucleus was added to every 1000 myofibers in cross‐section using a 12‐hour brdU‐labeling paradigm. The EOM thus appear to retain a stable nuclear population by an opposing process of apoptosis that results in myonuclear removal as visualized by terminal deoxynucleotidyltransferase‐mediated nick end labeling (TUNEL). Activated caspase‐3 was present in localized cytoplasmic domains extending from 10 to 210 μm within individual myofibers, suggesting segmental cytoplasmic reorganization. Understanding the cellular mechanisms that maintain this process of continuous myonuclear addition and removal in normal adult EOM may suggest new hypotheses to explain the preferential involvement or sparing of these muscles in skeletal muscle disease. © 2004 Wiley Periodicals, Inc. Muscle Nerve 29: 707–715, 2004
Syllable repertoire and the size of the song control system in captive canaries (Serinus canaria)
Authors: Leitner Stefan , Catchpole Clive K.
Published: April 2004

In songbirds, there is considerable interest in relationships between song structure and the size of the song control system in the forebrain. In male canaries, earlier studies have reported that repertoire size increased with age, and positive correlations were obtained between repertoire size and the volume of song control nuclei such as high vocal center (HVC). Here we investigate whether age has an effect upon both the song structure and the morphology of two song control nuclei [HVC and robustus archistriatalis (RA)] that are important in song production. We recorded songs from an aviary population of 1‐ and 2‐year‐old male domesticated canaries. We found that repertoire size, number of sexually attractive (sexy) syllables, and size of song nuclei did not differ between 1‐ and 2‐year‐old males. Neither did we find significant correlations between syllable repertoire size and the size of the song control nuclei. However, HVC size was positively correlated with the proportion of sexy syllables in the repertoires of 2‐year‐old males. Some older males may enhance vocal performance by modifying the control of syllables rather than by increasing repertoire size or neural space. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 21–27, 2004
Evidence for a secreted chemorepellent that directs glioma cell invasion
Authors: Werbowetski Tamra , Bjerkvig Rolf , Del Maestro Rolando F.
Published: April 2004

Secreted chemotropic cues guide the migration of neuronal and glial cell precursors during neural development. It is not known if chemotropism contributes to directing the invasion of brain tissue by glioma cells. A model system has been developed that allows quantification of invasive behavior using gliomas spheroids embedded in collagen gels. Here we provide evidence that glioma spheroids secrete a chemorepellent factor(s) that directs cells away from the spheroid and into the collagen matrix. The relationship between total invasion, cell number, and implantation distance suggests that glioma cells respond to a gradient of the chemorepellent cue(s) that is well established at 48 h. C6 astrocytoma cells normally invade the collagen at an angle perpendicular to the spheroid edge. In contrast, an adjacent spheroid causes cells to turn away from their normal trajectory and slow their rate of invasion. Astrocytoma cells are repelled by an adjacent glioma spheroid but rapidly infiltrate astrocyte aggregates, indicating that astrocytes do not express the repellent cue. Uniform concentrations of repellent factor(s) in spheroid conditioned medium overwhelm endogenous gradients and render glioma cells less able to exhibit this chemotropic response. Concentration gradients of spheroid conditioned medium in cell migration assays also demonstrate the chemorepellent cue(s)'s tropic effect. Our findings indicate that glioma spheroids produce a secreted diffusible cue(s) that promotes glioma cell invasion. Identification of this factor(s) may advance current therapies that aim to limit tumor cell invasion. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 71–88, 2004
Overexpression of Bcl‐2 prevents neomycin‐induced hair cell death and caspase‐9 activation in the adult mouse utricle in vitro
Authors: Cunningham Lisa L. , Matsui Jonathan I. , Warchol Mark E. , Rubel Edwin W.
Published: April 2004

Mechanosensory hair cells of the inner ear are especially sensitive to death induced by exposure to aminoglycoside antibiotics. This aminoglycoside‐induced hair cell death involves activation of an intrinsic program of cellular suicide. Aminoglycoside‐induced hair cell death can be prevented by broad‐spectrum inhibition of caspases, a family of proteases that mediate apoptotic and programmed cell death in a wide variety of systems. More specifically, aminoglycoside‐induced hair cell death requires activation of caspase‐9. Caspase‐9 activation requires release of mitochondrial cytochrome c into the cytoplasm, indicating that aminoglycoside‐induced hair cell death is mediated by the mitochondrial (or “intrinsic”) cell death pathway. The Bcl‐2 family of pro‐apoptotic and anti‐apoptotic proteins are important upstream regulators of the mitochondrial apoptotic pathway. Bcl‐2 is an anti‐apoptotic protein that localizes to the mitochondria and promotes cell survival by preventing cytochrome c release. Here we have utilized transgenic mice that overexpress Bcl‐2 to examine the role of Bcl‐2 in neomycin‐induced hair cell death. Overexpression of Bcl‐2 significantly increased hair cell survival following neomycin exposure in organotypic cultures of the adult mouse utricle. Furthermore, Bcl‐2 overexpression prevented neomycin‐induced activation of caspase‐9 in hair cells. These results suggest that the expression level of Bcl‐2 has important effects on the pathway(s) important for the regulation of aminoglycoside‐induced hair cell death. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 89–100, 2004
Correlation of Pax‐2 expression with cell proliferation in the developing chicken inner ear
Authors: Li Huawei , Liu Hong , Corrales C. Eduardo , Mutai Hideki , Heller Stefan
Published: April 2004

In vertebrates, the paired‐box transcription factor Pax‐2 is one of the earliest markers of the developing inner ear and is robustly expressed in the otic placode and the otic vesicle. Mutations in the Pax‐2 gene result in developmental defects of the vestibular and auditory apparatus. We set out to investigate whether regions of Pax‐2 expression in the developing otic vesicle correlate with areas of cell proliferation or cell death, which would indicate a possible role of Pax‐2 in these processes. Regionalized proliferation and local apoptosis are the principal mechanisms that lead to the complex morphogenesis of the highly compartmentalized inner ear starting from a simple vesicle. We found a high correlation of Pax‐2 expression with proliferating cells in the walls of the early otic vesicle. Apoptotic cells were mostly localized outside of the Pax‐2‐expressing regions. At later stages, we found the highest intensity of proliferating and Pax‐2‐positive cells in areas of the developing sensory epithelia. When hair cells begin to differentiate, they maintain a lower level of Pax‐2 expression than neighboring cells for a brief period, before they completely down‐regulate expression of this transcription factor. We conclude that a significant proportion of proliferating cells in the developing otocyst express Pax‐2, in particular in regions that include developing sensory patches. This implicates Pax‐2 as a marker for proliferating hair and supporting cell progenitors. Furthermore, the likelihood that Pax‐2‐expressing cells in the otocyst die by apoptosis is much lower when compared with cells residing in Pax‐2‐negative regions. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 61–70, 2004
Expression of BAFF (BLyS) in T cells infiltrating labial salivary glands from patients with Sjögren's syndrome
Authors: Lavie Frédéric , Miceli‐Richard Corinne , Quillard Jeanine , Roux Sophie , Leclerc Philippe , Mariette Xavier
Published: April 2004

Primary Sjögren's syndrome (pSS) is an autoimmune disorder characterized by lymphocytic infiltration of the salivary glands. Most of the infiltrating cells are T cells, but other features of the disease include polyclonal B‐cell activation, systemic production of autoantibodies, and increased risk of developing B‐cell non‐Hodgkin's lymphoma. Recently, a new tumour necrosis factor, the B‐cell activating factor (BAFF; also known as BLyS), has been implicated in the polyclonal activation of B cells. Using immunohistochemistry, this study evaluated BAFF expression in labial salivary gland biopsies from 14 patients with pSS, 14 normal controls, and two patients with sarcoidosis. Labial salivary gland samples from seven patients with pSS, seven controls, and one patient with sarcoidosis were double‐stained using indirect immunofluorescence. RT‐PCR analysis was also performed on lip biopsy samples from two patients and two controls. In all 14 pSS specimens, infiltrating inflammatory cells strongly expressed BAFF protein, as did some ductal epithelial cells, but acinar cells were negative. Some B cells were present in the vicinity of the BAFF‐positive cells. In the 14 normal labial salivary glands, some ductal cells were moderately positive, but acinar cells were negative. In the labial salivary glands from the two patients with sarcoidosis, infiltrating lymphocytes were not stained. BAFF mRNA expression was confirmed by RT‐PCR in salivary glands from pSS patients. Double immunofluorescence revealed T cells and macrophages to be the main cell types expressing BAFF in salivary glands from pSS patients. In conclusion, BAFF may be expressed by T cells at the site of autoimmune damage and could play a role in the pathogenesis of pSS, particularly by triggering the activation of self‐antigen‐driven autoimmune B cells. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Gene expression profiles from hypertrophic scar fibroblasts before and after IL‐6 stimulation
Authors: Dasu Mohan RK , Hawkins Hal K , Barrow Robert E , Xue Hui , Herndon David N
Published: April 2004

The structural rearrangement of collagen fibres in hypertrophic scar causes abnormal contracture, low tensile strength, and raised scars, which cause functional impairment and disfigurement. It is hypothesized that changes in the genes of cytokines, extracellular matrix proteins, and proteins regulating programmed cell death are related to hypertrophic scar formation. To test this hypothesis, fibroblasts were cultured from hypertrophic scars and their response to interleukin‐6 (IL‐6) stimulation was studied by defining their gene expression profiles. Affymetrix gene chip analysis was used to identify up‐ or down‐regulation in the 12 625 genes present in the affymetrix array. RT‐PCR and ELISA assays were used to validate microarray expression profiles further. Comparison of gene profiles showed an increase of 12 genes in hypertrophic scar fibroblasts compared with normal skin fibroblasts, while the expression of 14 genes decreased. Thirty‐three genes were affected by IL‐6 treatment in the hypertrophic scar fibroblasts, while 57 genes were affected in normal skin fibroblasts. Messenger RNA to β‐actin ratios for matrix metalloproteinase‐1 (MMP‐1) and MMP‐3 were increased with IL‐6 in normal skin fibroblasts from 2.43 ± 0.06 to 5.50 ± 0.45 and from 0.75 ± 0.09 to 1.98 ± 0.01, respectively. No change in these matrix metalloproteinases could be shown with IL‐6 stimulation in hypertrophic scar fibroblasts. Secreted protein levels of pro‐MMP‐1 and MMP‐3 were elevated in the supernatants from normal skin fibroblasts from 2.00 ± 0.09 and 1.72 ± 0.10 ng/ml to 4.60 ± 0.12 and 3.41 ± 0.20 ng/ml, respectively, after treatment with IL‐6 (p < 0.05). No changes were observed in hypertrophic scar fibroblasts treated with IL‐6. Values are means ± SEM. The absence of any up‐regulation of MMP‐1 and MMP‐3 in hypertrophic scar fibroblasts, in response to IL‐6, suggests that suppression of matrix metalloproteinases may play a role in the excessive accumulation of collagen formed in hypertrophic scars. While the pathogenesis of abnormal hypertrophic scars remains poorly understood, the use of gene expression arrays may prove helpful in identifying the mechanisms responsible for this type of abnormal scar formation and in formulating an effective therapeutic protocol. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
TIMP‐3 and endocrine therapy of breast cancer: an apoptosis connection emerges
Authors: Edwards Dylan R
Published: April 2004

The tissue inhibitors of metalloproteinases (TIMPs) control the activities of matrix metalloproteinases (MMPs) and as such, they have been recognized as potential suppressors of angiogenesis and tumour invasion and metastasis. However, TIMP‐3 has several unique properties that set it apart from other TIMPs, including its ability to bind to extracellular matrix, inhibit related adamalysin metalloproteinases (ADAMs), and induce apoptosis. New data suggest that high levels of TIMP‐3 mRNAs in human breast tumours are associated with success of adjuvant endocrine therapy, but not chemotherapy. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Under‐reporting of serious adverse drug reactions in Sweden
Authors: Bäckström M , Mjörndal T , Dahlqvist R
Published: April 2004

Introduction

Adverse drug reactions (ADR) constitute a major problem, both from a medical point of view and as an economical burden. Spontaneous reporting of ADRs is one of the methods for post marketing surveillance of drug safety. Under‐reporting can also provide an important obstacle to rapid and relevant signal detection.

Aim

To investigate the rate of under‐reporting serious ADRs of selected ICD 10 diagnoses.

Method

In order to investigate the under‐reporting rate we investigated at five hospitals within the county of Norrbotten in Sweden the total number of diagnosed cases during a period of 5 years (1996–2000) with the following diagnoses: cerebral haemorrhage (I 61.0–I 61.9), pulmonary embolism (I 26.0 and I 26.9), embolism or thrombosis (I 74.0–I 74.9), phlebititis, thrombophlebitits or venous thrombosis (I 80.0–I 80.3, I 80.8 and I 80.9) and portal vein thrombosis and other thrombosis or emboli (I 82.0–I 82.3, I 82.8 and I 82.9). The identity of these patients was obtained through a database search. The patients' case records were then scrutinized by a specially trained nurse and the drugs used at the time of the event were noted. An assessment of the possibility of an ADR was performed using standard WHO causality criteria. Later, database search in the Swedish ADR registry was performed in order to investigate whether these suspected ADRs had been reported to the national authority in Sweden or not.

Results

In total 1349 case records were found and scrutinized. Of these, 107 patients had received drugs that could have been a probable or possible cause to the diagnoses. Of these 92 cases had not been reported and only 15 patients were found in the database, giving an overall under‐reporting rate of all ADRs of 86%.

The most commonly occurring diagnoses were cerebral haemorrhage followed by venous thrombosis, 545 and 468 respectively. Among those cases that should have been reported according to the existing rules for spontaneous reporting of suspected ADRs the most frequently occurring diagnosis was cerebral haemorrhage (I 61.0) in connection to treatment with anticoagulants.

Conclusion

The rate of spontaneous ADR reporting is very low, also for serious and fatal reactions. Copyright © 2004 John Wiley & Sons, Ltd.
The thickness profile of ultra‐high molecular weight polyethylene films during sequential biaxial drawing
Authors: Moens M. T. R. , Govaert L. E. , Peters G. W. M. , Meijer H. E. H.
Published: April 2004

In this study, the evolution of the thickness profile of UHMW‐polyethylene films during sequential biaxial drawing is studied. The basic assumption is that a nonuniform thickness distribution of the drawn film is the result of the amplification of initial imperfections. Finite element simulations of the drawing process have been performed in which the drawing of a piece of film with a geometric imperfection is considered. For these numerical simulations, a viscoelastic model is adopted. Although the model does not describe the behavior of UHMW‐PE films in full detail, it is able to capture typical features of inhomogeneous deformation. The most striking observation is that severe localization occurs at the beginning of the second drawing step (i.e. in the direction transverse to the first step). In this stage of the drawing process, a localization band develops. These phenomena are also observed in validation experiments. A discrepancy between the simulations and the validation experiments is observed at the end of the drawing process. In the simulations, the deformation is stabilized again, and the resulting thickness profile is practically uniform. In the experiments however, the bad thickness profile at the beginning of the second drawing step is conserved up to the end of the drawing process. The simulations have been performed for different process parameters. Hence, it is possible to access the influence of these parameters on the evolution of the thickness profile. Furthermore, a suggestion is done to explain the deformation phenomena. The stability of the deformation can be determined from stress‐strain curves during the biaxial drawing process. It is concluded that, although no absolute values are acquired, trends are predicted correctly and they can serve as quidelines for process control.
An alternative model for predicting the cure kinetics of a high temperature cure epoxy adhesive
Authors: Rogers Angela D. , Lee‐Sullivan Pearl
Published: April 2004

The purpose of this work was to develop a cure kinetics model for a commercially available high temperature cure epoxy adhesive commonly used in the aerospace industry. While there are several phenomenological cure kinetic models commonly used in the literature for describing the rate of conversion of thermosetting epoxy adhesives as a function of degree of conversion, none of these models adequately depicts the adhesive used in this work over the entire range of conversion. Hence, by curve fitting empirical data collected using differential scanning calorimetry and refinement of existing models, an alternative model is proposed. The form of the present model suggests that chemical curing is the result of the combination of two autocatalytic reactions. The model is able to account for both the chemically controlled and diffusion controlled regimes of the cure. This paper also describes a novel iterative approach for predicting kinetics parameters as a function of isothermal cure temperature. Excellent agreement between experimental measurements and model predictions has been demonstrated over the entire range of conversion.
Analysis of closed‐discharge single‐screw extrusion of power‐law fluids
Authors: Guzmán Job D. , Schieber Jay D.
Published: April 2004

For rheometry and polymer processing applications, it is important to correlate fluid material properties with extrusion parameters like pressure buildup and revolutions per minute. Previous attempts to obtain such correlations have resorted to numerical techniques or approximate relationships. Here we show that upon a suitable rotation of coordinate axes, analysis of the metering zone in closed‐discharge single‐screw extrusion is simplified. Taking advantage of such simplification, we have derived an analytic, self‐consistent relation between fluid properties and extrusion parameters, where the power‐law model is used throughout the analysis.
Residual birefringence in modified polycarbonates
Authors: Wimberger‐Friedl R. , de Bruin J. G. , Schoo H. F. M.
Published: April 2004

The residual birefringence in quenched and injection‐molded specimens of bisphenol‐A polycarbonate (BAPC) homopolymer and its copolymers with substituted bisphenol‐A is investigated. The chemical modifications lead to a different stressoptical behavior in the melt and glass state, which generates differences in the residual birefringence of molded specimens. In this way the origins of the residual birefringence can be interpreted in a better way. In quenched samples it is found that the level of birefringence depends on the stress‐optical coefficient in the glassy state, but the unbalance of the birefringence distributions scales with the stress‐optical coefficient in the melt state. This supports the idea that transient thermal stresses present during vitrification induce molecular orientation, which is responsible for the unbalance of the distributions. The residual birefringence distributions in injection‐molded specimens all display a broad plateau in the core, as is usually observed in BAPC. The level of the plateau is found to scale with the stress‐optical coefficient of the melt state. This is a proof for the interpretation of this plateau being induced by transient thermal stresses during vitrification and not by residual stresses. It cannot be eliminated by optimizing molding conditions but only by drastically reducing the stress‐optical coefficient in the melt state.
Effect of reactive compatibilization on the interfacial slip in nylon‐6/EPR blends
Authors: Van Puyvelde P. , Oommen Z. , Koets P. , Groeninckx G. , Moldenaers P. , Leuven K. U. , Eindhoven T. U. , Leuven K. U.
Published: April 2004

The viscosity of uncompatibilized polymer blends often shows a negative deviation from a log‐additivity rule at shear rates relevant to processing. This deviation has been attributed to interfacial slip, which is related to the loss of entanglements at the interface. In this work interfacial slip and the effect of reactive compatibilization on this phenomenon are studied in blends consisting of ethylene‐propylene rubber and nylon‐6. The viscosity and morphology of blends with various compositions and compatibilizer content are investigated systematically. The results indicate that interfacial slip can indeed be important in uncompatibilized systems whereas it is suppressed in compatibilized blends. This is further supported by a study of the viscosity of multilayer structures. Both the effect of reactive compatibilization and of the number of layers on the rheology are studied. Again it is demonstrated that reactive compatibilization suppresses interfacial slip.
Novel ultrasonic process for in‐situ copolymer formation and compatibilization of immiscible polymers
Authors: Isayev A. I. , Hong Chang Kook
Published: April 2004

In‐situ copolymer formation and compatibilization of immiscible polymers in blends were discovered to occur during ultrasonic‐assisted extrusion in the melt state under high pressures. Residence times were of the order of seconds. The mechanical performance of plastic/rubber and rubber/rubber blends subjected to ultrasonic treatment was significantly enhanced compared to those of identical blends not subjected to ultrasonic treatment and having similar phase morphologies. The appearance of a high molecular weight tail in the rubber/rubber blends, stabilization of phase morphology in the melt state, the presence of a transition interface nanolayer and a decrease in the amount of extractable components in the plastic/rubber blends after ultrasonic‐assisted extrusion point towards the occurrence of in‐situ copolymer formation at the interfaces.
Application of ultrasound in the determination of fundamental extrusion performance: Residence time distribution measurement
Authors: Sun Z. , Jen C.‐K. , Shih C.‐K. , Denelsbeck D. A.
Published: April 2004

By means of new probe design and rapid data acquisition, we have succeeded in in‐line ultrasonic monitoring of residence time distribution (RTD) at the melting, mixing, and pumping zones as well as at the die exit of a Werner & Pfleiderer 30‐mm twin‐screw extruder by mounting the ultrasonic probes on the extruder barrel over the screw elements and at the die. The experimental systems were LDPE, CaCO3‐filled LDPE, and a Kraton/LDPE blend. The ultrasonic data at each of the extruder functional zones are presented. The ultrasonic results have been used to evaluate an opical RTD measurement method by using an optical sensor side by side with one ultrasonic probe at the mixing zone of the extruder. The comparison of the ultrasonic and optical results has shown that the presented ultrasonic technique could be a good complement to the optical technique in the monitoring and understanding of RTD during polymer extrusion processes.
Impact behavior and modeling of engineering polymers
Authors: Duan Y. , Saigal A. , Greif R. , Zimmerman M. A.
Published: April 2004

Because of their many unique and desirable properties, engineering polymers have increasingly been applied in applications where impact behavior is of primary concern. In this paper, the impact behavior of a glassy polymer acrylonitrile‐butadiene‐styrene (ABS) and a semicrystalline polymer alloy of polycarbonate and polybutylene‐terephthalates (PBT) are obtained as a function of impact velocity and temperature from the standard ASTM D3763 multiaxial impact test. As computer simulation of destructive impact events requires two material models, a constitutive model and a failure model, uniaxial mechanical tests of the two polymers are carried out to obtain true stress vs, true strain curves at various temperatures and strain rates. The generalized DSGZ constitutive model, previously developed by the authors to uniformly describe the entire range of deformation behavior of glassy and semicrystalline polymers for any monotonic loading modes, is calibrated and applied. The thermomechanical coupling phenomenon of polymers during high strain rate plastic deformation is considered and modeled. A failure criterion based on maximum plastic strain is proposed. Finally, the generalized DSGZ model, the thermomechanical coupling model, and the failure criterion are integrated into the commercial finite element analysis package ABAQUS/Explicit through a user material subroutine to simulate the multiaxial impact behavior of the two polymers ABS and PBT. Impact load vs. striker displacement curves and impact energy vs. striker displacement curves from computer simulation are compared with multiaxial impact test data and were found to be in good agreement.
Properties of rapid prototype injection mold tooling materials
Authors: Rodet Vincent , Colton Jonathan S.
Published: April 2004

Epoxy acrylate‐based sterolithography resins have been used successfully as tools for injection molding. Molds made out of these resins fail at distinct times: during the first injection of plastic; during the first part first ejection; during either injection or ejection, but after a certain number of parts have been produced, which can be compared to a fatigue process. This paper presents corelations between measured properties of stereolithography molds and injection molding processing conditions so as to understand and predict mold failure. The study focuses on two stereolithography resins (SL 7510 and SL 7510) and one epoxy‐based composite material used for the high speed machining of prototype molds (Renboard). Rapid tooling materials are studied in fatigue, tensile, and fracture at injection molding operating temperatures and at room temperature. Finally, a method to address failure of molds is proposed using the theory of fracture.
Dynamic mechanical signatures of Viton A and plastic bonded explosives based on this polymer
Authors: Mark Hoffman D.
Published: April 2004

The complex shear moduli of the fluorelastomer Viton A and four plastic bonded explosives LX‐04, LX‐07, LX‐10, and LX‐11, which use this polymer as a binder, have been investigated. LX‐10, LX‐07, LX‐04 and LX‐11 are composites of 94.5, 90, 85 and 80% 1, 3, 5, 7‐tetranitroazacyclooctane (HMX) explosive, respectively, and Viton A. Viton is a random copolymer of 7 vinylidene fluoride and 2 perfluoropropene monomers. In the temperature range from −150 to 120°C, two relaxations, the β relaxation at −80°C and the glass transition at −22°C, were observed as peaks in the loss modulus in Viton A at 0.1 Hz. A third relaxation, Tα, was found above Tg in all four explosive formulations. The plastic bonded explosives (PBX's) showed antiplasticization phenomena. Tg of the explosives increased 2–3°C as the concentration of binder was reduced in 5% steps. Samples from the same original lot of LX‐04 were evaluated after 20–23 years of service. The alpha relaxation occurred at 60°C as a peak in the loss modulus at 1 Hz. Both the beta and alpha relaxations were very broad and an accurate maximum for these relaxations was difficult to determine.
Effect of process conditions on the weld‐line strength and microstructure of microcellular injection molded parts
Authors: Turng Lih‐Sheng , Kharbas Hrishikesh
Published: April 2004

This study was aimed at understanding how the process conditions affect the weld‐line strength and microstructure of injection molded microcellular parts. A design of experiments (DOE) was performed and polycarbonate tensile test specimens were produced for tensile tests and microscopic analysis. Injection molding trials were performed by systematically adjusting four process parameters (i.e., melt temperature, shot size, supercritical fluid (SCF) level, and injection speed). For comparison, conventional solid specimens were also produced. The tensile strength was measured at the weld line and away from the weld line. The weld‐line strength of injecton molded microcellular parts was lower than that of its solid counterparts. It increased with increasing shot size, melt temperature, and injection speed, and was weakly dependent on the supercritical fluid level. The microstructure of the molded specimens at various cross sections were examined using scanning electron microscope (SEM) and a light microscope to study the variation of cell size and density with different process conditions.
Industrial solidification processes in polybutene‐1. Part I—quiescent melts
Authors: Braun J. , Pillichshammer D. , Eder G. , Janeschitz‐Kriegl H.
Published: April 2004

In the first paper of this series the principles for solidification of crystallizable polymers under heat transfer conditions are discussed for the case of the absence of flow. For industrial polymers, which, in general, are forced to crystallize at large undercoolings, the pertinent kinetic data are extremely rare. In the present paper the growth speeds of spherulites and the number of nuclei per unit volume are presented as functions of temperature for two industrial polybutene‐1 grades.