bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of chain‐extended bismaleimide modified polyurethane–epoxy matrices
Authors: Mahesh K. P. O. , Alagar M. 
Published: January 2003

AbstractIntercrosslinked networks of bismaleimide (BMI) modified polyurethane–epoxy systems were prepared from chain‐extended BMI and polyurethane modified epoxy and cured in the presence of 4,4′‐diaminodiphenylmethane. Infrared spectral analysis was used to confirm the grafting of polyurethane onto the epoxy skeleton. The prepared matrices were characterized by mechanical, thermal, and morphological studies. The results, obtained from the mechanical and thermal studies, reveal that the incorporation of polyurethane into epoxy increases the mechanical strength and decreases the glass‐transition temperature and thermal stability. The incorporation of chain‐extended BMI into polyurethane modified epoxy systems increases the thermal stability and both tensile and flexural properties, and decreases the impact strength and glass‐transition temperature. Surface morphologies of polyurethane modified epoxy and chain‐extended BMI modified polyurethane– epoxy systems were studied by scanning electron microscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1562–1568, 2003
Polystyrene/bisphenol a polycarbonate (PS/PC) molecular composite by in situ polymerization. II. Effect of different molecular size of PC on the blending behavior and properties
Authors: Jang Lee Wook , Lee Dong Choo 
Published: January 2003

AbstractThe influences of different molecular sizes and contents of bisphenol A polycarbonate (PC) on the miscibility, morphology, and physical properties of a polystyrene/PC (PS/PC) molecular composite are examined. The polymerization of the matrix monomer, styrene, which is completely miscible with PC, affords an apparently homogeneous mixture that remains stable on heating to above the glass transition temperature (Tg) of the pure matrix and solubilizes in common organic solvents. Both the molecular and material characterizations for the purified products are examined in full detail by various instrumental analyses and microscopy. An enhanced miscibility with higher molar mass of PC was confirmed by both the unambiguous scanning electron microscopy (SEM) images, showing subinclusions of PS/PC microdomains in the matrix, and the characteristic size exclusion chromatograms (SEC) of the fractionated sample, exhibiting homogeneous molecular mixing. With increased molecular size of PC and its content, the Tg increases proportionally and shows a shift to higher temperatures than that of pure PC, indicating the reduced segmental motion of PC chains due to the intimate chain entanglement with PS chains. Except for the case of the lowest molar mass of PC, both the thermal and tensile properties of the composite are also elevated. The conformational similarity between the two long flexible‐chain polymers has clearly accentuated the tendency for miscibility. This effect is due mainly to the increase in entropy gained by mixing, which in turn leads to reinforcement of n–π complex formation between the carbonate and benzene mixtures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1610–1618, 2003
Structure–property behavior of UV‐curable polyepoxy–acrylate hybrid materials prepared via sol–gel process
Authors: Zhang Ling , Zeng Zhaohua , Yang Jianwen , Chen Yonglie 
Published: January 2003

AbstractUV‐curable, hard, transparent organic/inorganic hybrid material with an improved mechanical property was prepared by the sol–gel process, based on a commonly used epoxy acrylate (EA) oligomeric resin. Systematic experiments were carried out to study the effect of the inorganic content, the acid content, and the content of a silane coupling agent on the property behavior of the hybrid materials. The structure of the hybrids were characterized by IR spectra and SEM observation. Results from thermogravimetric analysis (TGA) and mechanical measurement show that the properties of the hybrids differ with the changes of these variables. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1654–1659, 2003
Controlling the phase stability of polymer blends through the introduction of impenetrable interfaces
Authors: Oréfice Rodrigo L. , Barbosa Ana Paula C. , Nogueira Marcos M. N. 
Published: January 2003

AbstractIn this work, the effect of the introduction of modified solid surfaces into polymer blends on the phase‐separation process was investigated. Glass fibers with surfaces having different chemistries were introduced into polystyrene–poly(methyl methacrylate) blends. The glass fibers used either had fully hydrated surfaces or had surfaces covered with a random copolymer, poly(styrene‐co‐methyl methacrylate). The copolymer was synthesized by free‐radical polymerization of styrene and methyl methacrylate in the presence of previously vinyl silane‐treated glass fibers. The copolymerization and grafting procedures were investigated by FTIR and thermal analysis. Blends containing the fibers were studied using FTIR microscopy and optical microscopy. FTIR microscopy results showed that the composition of the phases in the blends was shifted by using fibers with different surface chemistries. Fibers with grafted copolymers were capable of narrowing the immiscibility region in the phase diagram, while fully hydrated fibers were able to expand the gap. It was proposed that interfacial interactions regulated by a hydrophilic–hydrophobic type of forces were responsible for guiding the described phase‐separation process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1619–1627, 2003
Rheology, cure characteristics, physical and mechanical properties of tire tread reclaimed rubber/natural rubber compounds
Authors: Sombatsompop N. , Kumnuantip C. 
Published: January 2003

AbstractThis work aimed to examine the effect of addition of tire‐tread reclaimed rubber on the properties of two natural rubber (NR) compounds with respect to the reclaimed rubber concentration and mastication time, the properties of interest including rheological and cure characteristics, physical and mechanical properties. The results under the test conditions suggested that Mooney Plasticity and shear viscosity increased with reclaimed rubber content, but decreased with mastication time. The greater the molar mass of the natural rubber the higher the sensitivity to the change in compound viscosity due to mastication and reclaimed rubber content. The die swell was more dependent on the reclaimed rubber than the molar mass of the rubbers. The cure rate and scorch time were found to increase and decrease with reclaimed rubber content, respectively, whereas the cure time was independent of the reclaimed rubber content. For vulcanized rubbers, it was also observed that 100% modulus of the rubber increased with reclaimed rubber content, but this was not the case for tensile stress and elongation at break. The hardness and heat buildup properties of the vulcanizates increased with reclaimed rubber content whereas the tear strength became independent of the reclaimed rubber. The findings in this work suggested that the variations in the rheological and cure characteristics for the unvulcanized rubber were very much dependent on the molar mass of the rubber whereas the mechanical properties for the vulcanized rubber were influenced by crosslink density. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1723–1731, 2003
Rotation and scale invariant wavelet feature for content‐based texture image retrieval
Authors: Lee Moon‐Chuen , Pun Chi‐Man 
Published: January 2003

AbstractThis article introduces an effective rotation and scale invariant log‐polar wavelet texture feature for image retrieval. The proposed feature is an attempt to enhance the existing content‐based image retrieval systems that largely present difficulty in coping with images with changes in orientations and scales. The underlying feature extraction process involves a log‐polar transform followed by an adaptive row shift invariant wavelet packet transform. The log‐polar transform converts a given image into a rotation and scale invariant but row‐shifted image, which is then further processed through an adaptive row‐shift invariant wavelet packet transform operation to generate adaptively selected subbands of rotation and scale invariant wavelet coefficients, based on an information cost function. An energy signature is computed for each subband of these wavelet coefficients. To reduce feature dimensionality, only the most dominant log‐polar wavelet energy signatures are selected for the feature vector for image retrieval. The overall feature extraction process is quite efficient and involves only O(n · log n) complexity. Experimental results show that this rotation and scale invariant wavelet feature is quite effective for image retrieval and outperforms the traditional wavelet packet signatures.
A bit more to it: Scholarly Communication Forums as Socio‐Technical Interaction Networks
Authors: Kling Rob , McKim Geoffrey , King Adam 
Published: January 2003

AbstractIn this article, we examine the conceptual models that help us understand the development and sustainability of scholarly and professional communication forums on the Internet, such as conferences, pre‐print servers, field‐wide data sets, and collaboratories. We first present and document the information processing model that is implicitly advanced in most discussions about scholarly communications—the “Standard Model.” Then we present an alternative model, one that considers information technologies as Socio‐Technical Interaction Networks (STINs). STIN models provide a richer understanding of human behavior with online scholarly communications forums. They also help to further a more complete understanding of the conditions and activities that support the sustainability of these forums within a field than does the Standard Model. We illustrate the significance of STIN models with examples of scholarly communication forums drawn from the fields of high‐energy physics, molecular biology, and information systems. The article also includes a method for modeling electronic forums as STINs.
Information science research agenda in Slovakia: History and emerging vision
Authors: Steinerová Jela 
Published: January 2003

AbstractResearch and education in library and information science in Slovakia is presented as an example of the history, present state and future of information science research and collaboration in central European countries. The professional experience in the region since 1990 has been outlined and particular contribution to other countries proposed. Closer collaboration of central and east European countries in information research is needed. Wider context of professional experience covers rapid changes of local information environment, different ways of problem recognition and solutions. Structural changes are shown in professional areas like curricular revision, new categories and terminology, new research methods, new ways to conduct open professional discourse and exchange of ideas. Many professional events, projects, organizations, foundations and published works are named as examples of these changes. Several research projects of the Department of LIS in recent 10 years are described in detail including a new project on the interaction of man and the information environment. In conclusion, future directions of common research are outlined with the emphasis on digital libraries, cognitive and social aspects of the information process and diverse cultural approaches to information transfer and use.
Prospective and retrospective evaluations of experiences: how you evaluate an experience depends on when you evaluate it
Authors: Soman Dilip 
Published: January 2003

AbstractPrior research (cf. Soman & Shi, 2001) has shown that obstacles and periods of low progress in an experience reduce the evaluation of that experience. In this research, we propose that the temporal distance between the obstacle and the time of making the evaluation moderates the effect of the obstacle. Consequently, an early (late) obstacle reduces prospective (retrospective) evaluation more significantly than a late (early) obstacle. In two experiments, we find support for this temporal proximity hypothesis. Further, differences between prospective and retrospective evaluations disappeared when the data were analyzed in terms of temporal distance, suggesting that the judgment policies underlying prospective and retrospective evaluations were the same. We also show that it is possible to create pairs of paths such that one of the two paths would be preferred when viewed in prospect, but the other path might be preferred in retrospect. Copyright © 2002 John Wiley & Sons, Ltd.
Verbal probabilities: a question of frame?
Authors: Teigen Karl Halvor , Brun Wibecke 
Published: January 2003

AbstractVerbal expressions of probability and uncertainty are of two kinds: positive (‘probable’, ‘possible’) and negative (‘not certain’, ‘doubtful’). Choice of term has implications for predictions and decisions. The present studies show that positive phrases are rated to be more optimistic (when the target outcome is positive), and more correct, when the target outcome actually occurs, even in cases where positive and negative phrases are perceived to convey the same probabilities (Experiments 1 and 2). Selection of phrase can be determined by linguistic frame. Positive quantifiers (‘some’, ‘several’) support positive probability phrases, whereas negative quantifiers (‘not all’) suggest negative phrases (Experiment 3). Positive frames induced by numeric frequencies (e.g. the number of students to be admitted) imply positive probability phrases, whereas negative frames (e.g. the number of students to be rejected) call for negative probability phrases (Experiment 4). It is concluded that choice of verbal phrase is based not only on level of probability, but also on situational and linguistic cues. Copyright © 2002 John Wiley & Sons, Ltd.
Outsourcing in the brain: Do neurons depend on cholesterol delivery by astrocytes?
Authors: Pfrieger Frank W. 
Published: January 2003

AbstractBrain function depends on the cooperation between highly specialized cells. Neurons generate electrical signals and glial cells provide structural and metabolic support. Here, I propose a new kind of job‐sharing between neurons and astrocytes. Recent studies on primary cultures of highly purified neurons from the rodent central nervous system (CNS) suggest that, during development, neurons reduce or even abandon cholesterol synthesis to save energy and import cholesterol from astrocytes via lipoproteins. The cholesterol shuttle may be restricted to compartments distant from the soma including synapses and may be regulated by electrical activity. Testing these hypotheses will help to improve our still insufficient understanding of brain cholesterol metabolism and its role in neurodegeneration. BioEssays 25:72–78, 2003. © 2002 Wiley Periodicals, Inc.
Movement through slits: Cellular migration via the Slit family
Authors: Piper Michael , Little Melissa 
Published: January 2003

AbstractFirst isolated in the fly and now characterised in vertebrates, the Slit proteins have emerged as pivotal components controlling the guidance of axonal growth cones and the directional migration of neuronal precursors. As well as extensive expression during development of the central nervous system (CNS), the Slit proteins exhibit a striking array of expression sites in non‐neuronal tissues, including the urogenital system, limb primordia and developing eye. Zebrafish Slit has been shown to mediate mesodermal migration during gastrulation, while Drosophila slit guides the migration of mesodermal cells during myogenesis. This suggests that the actions of these secreted molecules are not simply confined to the sphere of CNS development, but rather act in a more general fashion during development and throughout the lifetime of an organism. This review focuses on the non‐neuronal activities of Slit proteins, highlighting a common role for the Slit family in cellular migration. BioEssays 25:32–38, 2003. © 2002 Wiley Periodicals, Inc.
Masters change, slaves remain
Authors: Graham Patricia , Penn Jill K. M. , Schedl Paul 
Published: January 2003

AbstractSex determination offers an opportunity to address many classic questions of developmental biology. In addition, because sex determination evolves rapidly, it offers an opportunity to investigate the evolution of genetic hierarchies. Sex determination in Drosophila melanogaster is controlled by the master regulatory gene, Sex lethal (Sxl). DmSxl controls the alternative splicing of a downstream gene, transformer (tra), which acts with tra2 to control alternative splicing of doublesex (dsx). DmSxl also controls its own splicing, creating an autoregulatory feedback loop that ensures expression of Sxl in females, but not males. A recent paper1 has shown that in the dipteran Ceratitis capitata later (downstream) steps in the regulatory hierarchy are conserved, while earlier (upstream) steps are not. Cctra is regulated by alternative splicing and apparently controls the alternative splicing of Ccdsx. However, Cctra is not regulated by CcSxl. Instead it appears to autoregulate in a manner similar to the autoregulation seen with DmSxl. BioEssays 25:1–4, 2003. © 2002 Wiley Periodicals, Inc.
How the community effect orchestrates muscle differentiation
Authors: Buckingham Margaret 
Published: January 2003

AbstractThe “community effect” is necessary for tissue differentiation. In the Xenopus muscle paradigm, e‐FGF has been identified as a candidate community factor. Standley et al.1 now show that the community effect, mediated through FGF signalling, continues to be important at later stages of development in the posterior part of the embryo. In this region, the paraxial mesoderm is still undergoing segmentation into somites, which are the site of early skeletal muscle formation. Indeed, somitogenesis, together with the read‐out of the Hox code, which confers anteroposterior positional identity, is regulated by FGF signalling. This raises the question of the co‐ordination between these events and the community effect which orchestrates myogenesis. BioEssays 25:13–16, 2003. © 2002 Wiley Periodicals, Inc.
Child abuse fatalities and the media: lessons from a case study
Authors: Goddard Chris , Liddell Max 
Published: January 2003

AbstractThe role of the media in influencing child protection policy is explored by examination of the death of one child, Daniel Valerio, in Victoria, Australia. Daniel, 2 years old, died at the hands of his mother's de facto barely five months after he (Paul Aiton) moved in with Daniel's mother, Cheryl Butcher.[The Australian term ‘de facto’ is the equivalent of the English word ‘cohabitee’.] A series of reports to protective services highlighting multiple and severe bruising to Daniel were made; Daniel's postmortem revealed 104 bruises on his body. Although 21 professionals were involved in the case, tragedy was not averted; in fact, it was an electrician rather than trained professionals who recognized the obvious abuse. A series of inquiries into the case ensued; these were not immediately reported by the media, but press attention to the case intensified gradually. This led to a successful though paradoxical campaign by one newspaper, the Melbourne Herald Sun, to introduce the mandatory reporting of child abuse by health and welfare professionals. The paradox is that those people who needed to know of the case to protect Daniel knew about it before his death. This article analyses the campaign, highlights the factors which led to its success and provides succinct advice to professionals on the use of the media. Copyright © 1995 John Wiley & Sons, Ltd.
Effectively protecting black and minority ethnic children from harm: overcoming barriers to the child protection process
Authors: Webb Elspeth , Maddocks Alison , Bongilli Joan 
Published: January 2003

AbstractUnder the UN Convention, all children have the right to be protected from harm. However, there are barriers to the effective protection of children from Black and minority ethnic communities who are at risk of harm. This paper will explore these barriers in the context of three case histories and with reference to the literature. The cases illustrate some of the ways in which children are at risk and how the system currently fails to protect them. There are factors which increase the risk of harm faced by children or which reduce the likelihood that abuse in minority ethnic communities is recognized, acknowledged or dealt with appropriately. Other factors prevent effective partnerships with families, both to prevent abuse and in rehabilitation after abuse has occurred. Stereotyping, colour blindness, cultural deficit and inadequate training of professionals lead to failures in the statutory processes designed to protect children. These are compounded by wider societal factors, such as denial of abuse in ethnic minority communities, cultural differences in attitudes to disability and child‐rearing, the vulnerability of women in highly patriarchal communities, difficulties in providing mental health services across cultural boundaries and a lack of settings in which to provide appropriate alternative care and places of safety. Copyright © 2002 John Wiley & Sons, Ltd.
Comparison of outcomes in women and men treated with coronary stent implantation
Authors: Trabattoni Daniela , Bartorelli Antonio L. , Montorsi Piero , Fabbiocchi Franco , Loaldi Alessandro , Galli Stefano , Ravagnani Paolo , Cozzi Sergio , Grancini Luca , Liverani Antonio , Leon Maria E. , Robertson Chris , Boyle Peter 
Published: January 2003

AbstractWorse outcomes have been observed in women after PTCA. The present study was undertaken to compare clinical and angiographic results of coronary stenting among women and men. We retrospectively analyzed acute and 6‐month results in a consecutive series of 940 men and 160 women undergoing coronary stent implantation between May 1992 and January 1998. Women were older (63 vs. 57 years; P = 0.001), more often hypertensive (46.9% vs. 31.4%; P < 0.001) and diabetic (13.2% vs. 8.3%; P = 0.05), and less often smokers than men (32.5% vs. 70.5%; P < 0.001). A previous history of Q‐wave MI was less frequently present in women (28.2% vs. 40.2%; P = 0.003) who more often underwent coronary revascularization because of unstable angina (37.5% vs. 27.1%; P = 0.027). No difference was observed in coronary artery disease extension, lesion complexity, and stented vessel between the sexes. Bailout stenting was more frequently needed in women (28% vs. 17.8%; P = 0.001). No difference was observed in the number of stent implanted per vessel and per patient and average maximal inflation pressure used for stent postdilation. However, a smaller final balloon size was used in women. Procedural and clinical success was achieved in 94.4% and 92.5% of women and 96.7% and 94.5% of men (P = NS), respectively, without differences regarding in‐hospital major adverse cardiac events. Bleeding complications occurred more often in women when anticoagulation was used (OR = 2.87; 95% CI = 1.38–5.74). At 6‐month clinical follow‐up, TLR was similar between the sexes and event‐free survival was 75.5% in women and 81.5% in men (P = NS). Angiographic follow‐up, performed in 71% of the patients, showed that restenosis was 64% higher in women (OR = 1.64; 95% CI = 1.02–2.61). Despite older age, higher incidence of comorbidities, and more unstable presentation, women treated with coronary stenting showed acute and mid‐term clinical results similar to those observed in men. However, they were significantly more likely to develop angiographic restenosis. Cathet Cardiovasc Intervent 2003;58:20–28. © 2003 Wiley‐Liss, Inc.
Acute profound thrombocytopenia after use of eptifibatide for coronary stenting
Authors: Salengro Emmanuel , Mulvihill Niall T. , Farah Bruno 
Published: January 2003

AbstractThis is a case report of a patient who developed profound thrombocytopenia during treatment with eptifibatide after PCI of the mid right coronary artery. Cathet Cardiovasc Intervent 2003;58:73–75. © 2003 Wiley‐Liss, Inc.