bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of chitosan/citrate and chitosan/acetate films and applications for wound healing
Authors: Tanigawa Junichi , Miyoshi Norio , Sakurai Kensuke 
Published: July 2008

AbstractIn this work, we aimed to develop a scaffold of chitosan (CS) with a porous sponge structure for an artificial skin. The scaffolds were prepared from both CS/citric and CS/acetic solutions. In addition, the cast films were also prepared from the same solutions to compare some of their properties. They were characterized using WAXD, FTIR, DSC, tensile measurements, and SEM observation. It was found that CS/acetate had low crystallinity but CS/citrate was in an amorphous state, resulting in a large ductility with rubbery softness. Despite the different morphologies of CS/citrate and CS/acetate scaffolds, both scaffolds exhibited the wound healing effect available for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Electrospun cellulose nanofiber reinforced soybean protein isolate composite film
Authors: Chen Guanfushou , Liu Haiqing 
Published: July 2008

AbstractThis article presents the fabrication of cellulose nanofibrous mats (CNM) reinforced soybean protein isolate (SPI) composite with high visible light transmittance. The CNM was composed of cellulose nanofibers generated from electrospinning technique. The microstructure of the fractured surface of composite films was characterized by scanning electron microscopy (SEM). The light transmittance, mechanical properties, and swelling ratio of CNM/SPI composite were investigated in terms of CNM content in the composite. Because of the ultrafine diameter and superhigh length‐to‐diameter ratio of nanofibers, large amount of cellulose nanofibers fibers distribute in the SPI matrix to form an interpenetrating network (IPN) like composite material. It was found that strong interfacial interactions occurred at the cellulose nanofiber/SPI interfaces. The incorporation of 20 wt % cellulose nanofibers in the SPI matrix resulted in great improvement of mechanical strength and Young's modulus by respectively 13 and 6 times more than neat SPI film. More interestingly, this composite was translucent with light transmittance of over 75% at 700 nm. Furthermore, the swelling ratio of this IPN‐like CNM/SPI composite decreased from 106 to 22% as CNM content increased from 0 to 20 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Syntheses and properties of cross‐linked polymers from functionalized triglycerides
Authors: Zhao Hui‐Ping , Zhang Jian‐Feng , Susan Sun Xiuzhi , Hua Duy H. 
Published: July 2008

AbstractA number of functionalized triglycerides were synthesized from glyceryl trioleoate via epoxidation followed by reduction to give glyceryl tris(9‐hydroxy)trioleoate (a triol) or hydrolytic ring opening to obtain glyceryl tris(9,10‐dihydroxy)trioleoate (a hexaol). A selective monoepoxidation reaction of glyceryl trioleoate was also carried out and the resulting monoepoxide was hydrolyzed to give glyceryl 9,10‐dihydroxytrioleoate (a diol). Glyceryl tris(9‐hydroxy)trioleoate was brominated followed by displacement with sodium azide and reduction to give glyceryl tris(9‐amino)trioleoate (a triamine) and glyceryl tris[9‐(N‐isopropylamino)]trioleoate. These functionalized triglycerides were crosslinked with 1,4‐phenylene diisocyanate. The crosslinked polymers exhibit thermoset characteristics. Thermal analysis results suggest that the polymers are in amorphous states, and their thermal stability was significantly affected by crosslink degree. The crosslinked polymer derived from the diol retained 56% of its weight at 408°C, whereas the polymers derived from the aforementioned hexaol with higher crosslink degree retained only 36% of the original weight. Glass transition temperatures of these polymers range from −1.0°C to 10.2°C. The thermal stable polymer, 12, derived from the aforementioned diol exhibits a linear viscoelastic character and can be used as thermoplastics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on superabsorbent composites. XXI. Synthesis, characterization and swelling behaviors of chitosan‐g‐poly(acrylic acid)/organo‐rectorite nanocomposite superabsorbents
Authors: Liu Jianghua , Wang Aiqin 
Published: July 2008

AbstractA novel chitosan‐g‐poly(acrylic acid)/organo‐rectorite (CTS‐g‐PAA/OREC) nanocomposite superabsorbent was synthesized by aqueous polymerization using N, N′‐methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. Rectorite was organified with four different degree of hexadecyltrimethyl ammonium bromide, and the organification of rectorite was proved by FTIR and XRD. The effect of organification degree of rectorite on water absorbency of CTS‐g‐PAA/OREC with different organo‐rectorite content was investigated. The swelling behaviors in distilled water and various pH solutions were also studied. The results from IR spectroscopy and XRD data show that acrylic acid had been grafted polymerization with chitosan and organo‐rectorite and formed nanocomposite. Introducing organo‐rectorite into the CTS‐g‐PAA polymeric network can improved water absorbency and swelling rate of CTS‐g‐PAA/OREC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of rheological behavior of epoxy during precuring on foaming
Authors: Takiguchi Osamu , Ishikawa Daisaku , Sugimoto Masataka , Taniguchi Takashi , Koyama Kiyohito 
Published: July 2008

AbstractIn this study, the effect of rheological behavior of epoxy during precuring on foaming was investigated. Dynamic time sweep test of epoxy/curing agent (100/1, w/w) was conducted. The viscosities as a function of time showed extremely rapid increase from the order of 102–103 to 106Pa · s at a certain time, followed by slow increase of the viscosities. Dynamic frequency sweep test of precured epoxy with curing agent was conducted at 90°C. The critical gelation time was obtained by using rheological criterion proposed by Winter and Chambon. We found that the slopes of G′(ω) and G″(ω) decreased with increasing precuring time. Correspondingly, tan δ showed a change from negative to positive slope at a critical time. By using the results, the critical gelation time was determined as t = 895–935 s. Samples of epoxy/curing agent/blowing agent (100/1/0.5) were precured for 960–1620 s. And then precured samples were foamed at 230°C for 300 s to decompose chemical blowing agent. The formed bubble size distribution becomes sharp with increase of the precuring time. There are roughly two sizes of bubbles when precured for relatively short time (t < 1080 s) before foaming: large bubbles (>100 μm) and small ones (≅30 μm). On the other hand, foams precured for long time (t > 1200 s) before foaming, large bubbles disappear, and the average diameter of the bubble becomes small while the porosity is low. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Potential applications of poly(vinyl alcohol)‐congo red aqueous solutions and hydrogels as liquids for hydraulic fracturing
Authors: Vega Isabel , Fernández Emiliano , Mijangos Carmen , D'Accorso Norma , López Daniel 
Published: July 2008

AbstractThe authors report on the viscoelastic characterization of guar hydrogels obtained through complexation reactions with borax ions. These gels are compared with hydrogels obtained from poly(vinyl alcohol) of different degree of hydrolysis through complexation reactions with congo red. The effect of the degree of hydrolysis and both, the concentration of PVA and the concentration of congo red, on the viscoelastic properties of the hydrogels is analyzed. The potential use of the PVA‐based hydrogels as hydraulic fracturing liquids is discussed in relation to the commonly used fracturing liquid based on the guar–borax system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanisms of organophosphate resistance in a field population of oriental migratory locust, Locusta migratoria manilensis (Meyen)
Authors: Yang M.L. , Zhang J.Z. , Zhu K.Y. , Xuan T. , Liu X.J. , Guo Y.P. , Ma E.B. 
Published: July 2008

AbstractThe susceptibilities to three organophosphate (OP) insecticides (malathion, chlorpyrifos, and phoxim), responses to three metabolic synergists [triphenyl phosphate (TPP), piperonyl butoxide (PBO), and diethyl maleate (DEM)], activities of major detoxification enzymes [general esterases (ESTs), glutathione S‐transferases (GSTs), and cytochrome P450 monooxygenases (P450s)], and sensitivity of the target enzyme acetylcholinesterase (AChE) were compared between a laboratory‐susceptible strain (LS) and a field‐resistant population (FR) of the oriental migratory locust, Locusta migratoria manilensis (Meyen). The FR was significantly resistant to malathion (57.5‐fold), but marginally resistant to chlorpyrifos (5.4) and phoxim (2.9). The malathion resistance of the FR was significantly diminished by TPP (synergism ratio: 16.2) and DEM (3.3), but was unchanged by PBO. In contrast, none of these synergists significantly affected the toxicity of malathion in the LS. Biochemical studies indicated that EST and GST activities in the FR were 2.1‐ to 3.2‐fold and 1.2‐ to 2.0‐fold, respectively, higher than those in the LS, but there was no significant difference in P450 activity between the LS and FR. Furthermore, AChE from the FR showed 4.0‐fold higher activity but was 3.2‐, 2.2‐, and 1.1‐fold less sensitive to inhibition by malaoxon, chlorpyrifos‐oxon, and phoxim, respectively, than that from the LS. All these results clearly indicated that the observed malathion resistance in the FR was conferred by multiple mechanisms, including increased detoxification by ESTs and GSTs, and increased activity and reduced sensitivity of AChE to OP inhibition. Arch. Insect Biochem. Physiol. 2009. © 2008 Wiley‐Liss, Inc.
Up‐regulation of lysozyme gene expression during metamorphosis and immune challenge of the cotton bollworm, Helicoverpa armigera
Authors: Zhang Yong , Huang Jianhua , Zhou Bo , Zhang Chunlin , Liu Wenbin , Miao Xuexia , Huang Yongping 
Published: July 2008

AbstractLysozymes act as crucial bacteriolytic enzymes in insect immune system by hydrolyzing the β (1→4) bonds between N‐acetylglucosamine and N‐acetylmuramic acid in the peptidoglycan of prokaryotic cell walls. We have isolated and characterized a Helicoverpa armigera cDNA encoding an insect lysozyme named HaLyz. We amplified a fragment by PCR, using degenerate primers derived from the conservative amino acid sequences for performing 5′ and 3′ RACE. The full‐length cDNA was 661 base pairs. The theoretical pI and molecular weight of the protein were computed to be 9.08 and 15.6 kDa, respectively. Prokaryotic expression of the HaLyz ORF by Escherichia coli confirmed the calculated molecular weight of the protein. The deduced 135 amino acids showed high homology with known lysozymes from other insects, ranging from 47% to 89% by BLASTp search in NCBI. Analyses revealed that this protein has a typical lysozyme C signature among amino acids 93–111, CNVTCAEMLLDDITKASTC. An interesting relation between immunity and larva to pupa metamorphosis in insects was discovered. Real time‐PCR showed that HaLyz gene expression was transiently enhanced at the onset of metamorphosis of the cotton bollworm, Helicoverpa armigera. The gene expression was up‐regulated after the injection of E. coli or entomopathogenic fungi, Beauveria bassiana, but showed different expression patterns. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.
Annotations on musical scores by performing musicians: Collaborative models, interactive methods, and music digital library tool development
Authors: Winget Megan A. 
Published: July 2008

AbstractAlthough there have been a number of fairly recent studies in which researchers have explored the information‐seeking and management behaviors of people interacting with musical retrieval systems, there have been very few published studies of the interaction and use behaviors of musicians interacting with their primary information object, the musical score. The ethnographic research reported here seeks to correct this deficiency in the literature. In addition to observing rehearsals and conducting 22 in‐depth musician interviews, this research provides in‐depth analysis of 25,000 annotations representing 250 parts from 13 complete musical works, made by musicians of all skill levels and performance modes. In addition to producing specific and practical recommendations for digital‐library development, this research also provides an augmented annotation framework that will enable more specific study of human‐information interaction, both with musical scores, and with more general notational/instructional information objects.
Motivation for using search engines: A two‐factor model
Authors: Wu Ling‐Ling , Chuang Ya‐Lan , Chen Pin‐Yuen 
Published: July 2008

AbstractFrom a user‐centered perspective, an effective search engine needs to attract new users to try out its features, and retain those users so that they continue using the features. In this article, we investigate the relations between users'motivation for using (i.e., trying out and continuing to use) a search engine and the engine's functional features. Based on Herzberg's two‐factor theory (F. Herzberg, 2003; F. Herzberg, M. Bernard, & B. Snyderman, 1959), the features can be categorized as hygiene factors and motivation factors. Hygiene factors support the query process and provide a basic “task context” for information seeking that allows users to access relevant information. Motivation factors, on the other hand, help users navigate (i.e., browse) and comprehend the retrieved information, related to the “task‐content” aspect of information seeking. Given the consistent findings that hygiene factors induce work motivation for a shorter period of time, it is hypothesized that hygiene factors are more effective in attracting users; while motivation factors are more effective in retaining than in attracting users. A survey, with 758 valid participants, was conducted to test the hypotheses. The empirical results provide substantial support for the proposed hypotheses and suggest that the two‐factor theory can account for the motivation for using a search engine.
Applying the author affiliation index to library and information science journals
Authors: Cronin Blaise , Meho Lokman I. 
Published: July 2008

AbstractThe authors use a novel method—the Author Affiliation Index (AAI)—to determine whether faculty at the top‐10 North American library and information science (LIS) programs have a disproportionate presence in the premier journals of the field. The study finds that LIS may be both too small and too interdisciplinary a domain for the AAI to provide reliable results.
Re‐estimating the difficulty of closing the digital divide
Authors: James Jeffrey 
Published: July 2008

AbstractWhile we now know the most important determinants of the digital divide, such as income, skills, and infrastructure, little has been written about how these variables relate to one another. Yet, it is on the basis of one's answer to this question that the difficulty of closing the divide ultimately depends. In this article, I have sought to challenge the (implicit) prevailing assumption in most of the digital‐preparedness literature that variables can be perfectly substituted for one another and, hence, added together. In particular, and drawing on available evidence, I view the relationship between, say computers and computer skills, as being nearer the opposite extreme, of totally limited substitutability. On this basis, I suggest that the components of digital‐preparedness indexes be multiplied rather than added. Using multiplication rather than addition in most current indexes of digital preparedness reveals a substantial understatement of the real difficulty in closing the digital divide and a different set of policies to deal with this larger problem. Such policies should include sharing arrangements and the use of intermediaries.
A quick MST‐based algorithm to obtain Pathfinder networks (∞, n − 1)
Authors: Quirin Arnaud , Cordón Oscar , Guerrero‐Bote Vicente P. , Vargas‐Quesada Benjamín , Moya‐Anegón Felix 
Published: July 2008

AbstractNetwork scaling algorithms such as the Pathfinder algorithm are used to prune many different kinds of networks, including citation networks, random networks, and social networks. However, this algorithm suffers from run time problems for large networks and online processing due to its O(n4) time complexity. In this article, we introduce a new alternative, the MST‐Pathfinder algorithm, which will allow us to prune the original network to get its PFNET(∞, n − 1) in just O(n2 · log n) time. The underlying idea comes from the fact that the union (superposition) of all the Minimum Spanning Trees extracted from a given network is equivalent to the PFNET resulting from the Pathfinder algorithm parameterized by a specific set of values (r = ∞ and q = n − 1), those usually considered in many different applications. Although this property is well‐known in the literature, it seems that no algorithm based on it has been proposed, up to now, to decrease the high computational cost of the original Pathfinder algorithm. We also present a mathematical proof of the correctness of this new alternative and test its good efficiency in two different case studies: one dedicated to the post‐processing of large random graphs, and the other one to a real world case in which medium networks obtained by a cocitation analysis of the scientific domains in different countries are pruned.
Revising and polishing a structured abstract: Is it worth the time and effort?
Authors: Hartley James , Betts Lucy 
Published: July 2008

AbstractMany writers of structured abstracts spend a good deal of time revising and polishing their texts—but is it worth it? Do readers notice the difference? In this paper we report three studies of readers using rating scales to judge (electronically) the clarity of an original and a revised abstract, both as a whole and in its constituent parts. In Study 1, with approximately 250 academics and research workers, we found some significant differences in favor of the revised abstract, but in Study 2, with approximately 210 information scientists, we found no significant effects. Pooling the data from Studies 1 and 2, however, in Study 3, led to significant differences at a higher probability level between the perception of the original and revised abstract as a whole and between the same components as found in Study 1. These results thus indicate that the revised abstract as a whole, as well as certain specific components of it, were judged significantly clearer than the original one. In short, the results of these experiments show that readers can and do perceive differences between original and revised texts—sometimes—and that therefore these efforts are worth the time and effort.
Proper nouns in English–Arabic cross language information retrieval
Authors: Bellaachia Abdelghani , Amor‐Tijani Ghita 
Published: July 2008

AbstractOut of vocabulary words, mostly proper nouns and technical terms, are one main source of performance degradation in Cross Language Information Retrieval (CLIR) systems. Those are words not found in the dictionary. Bilingual dictionaries in general do not cover most proper nouns, which are usually primary keys in the query. As they are spelling variants of each other in most languages, using an approximate string matching technique against the target database index is the common approach taken to find the target language correspondents of the original query key. N‐gram technique proved to be the most effective among other string matching techniques. The issue arises when the languages dealt with have different alphabets. Transliteration is then applied based on phonetic similarities between the languages involved. In this study, both transliteration and the n‐gram technique are combined to generate possible transliterations in an English–Arabic CLIR system. We refer to this technique as Transliteration N‐Gram (TNG). We further enhance TNG by applying Part Of Speech disambiguation on the set of transliterations so that words with a similar spelling, but a different meaning, are excluded. Experimental results show that TNG gives promising results, and enhanced TNG further improves performance.
Titanocene‐Catalyzed Regioselective Alkylation of Styrenes with Grignard Reagents Using β‐Bromoethyl Ethers, Thioethers, or Amines
Authors: Terao Jun , Kato Yuichiro , Kambe Nobuaki 
Published: July 2008

AbstractRegioselective double alkylation of styrenes with alkyl Grignard reagents and alkyl bromides having a heteroatom functional group at the β‐position has been achieved by the use of a titanocene catalyst in THF. When ether was used instead of THF as a solvent, monoalkylation by substitution of a vinylic hydrogen atom with an alkyl group proceeded under similar conditions. These reactions involve the addition of alkyl radicals to styrenes to form benzylic radical intermediates.
Highly Active and Removable Ruthenium Catalysts for Transition‐Metal‐Catalyzed Living Radical Polymerization: Design of Ligands and Cocatalysts
Authors: Ouchi Makoto , Ito Makoto , Kamemoto Satoshi , Sawamoto Mitsuo 
Published: July 2008

AbstractThe systematic search and design of phosphine ligands (PR3) and amine cocatalysts resulted in obtaining pentamethyl‐cyclopentadienyl (Cp*) ruthenium(II) phosphine complexes [RuCp*Cl(PR3)2], which are highly active and removable catalysts, for transition‐metal‐catalyzed living radical polymerization of methyl methacrylate (MMA). The catalysts are conveniently prepared in situ from a tetrameric precursor [RuCp*(μ3‐Cl)]4 and a selected phosphine (PR3). The combination of the meta‐tolyl phosphine [P(m‐Tol)3] ligand and a primary diamine cocatalyst [NH2(CH2)6NH2] provides a highly active catalytic system with precision control of the molecular weight of the polymer. The high activity enables a low catalyst dose and a high turn‐over frequency without deteriorating the controllability. A hydrophilic amine cocatalyst (amino alcohol) in place of the diamine, further forms an active and removable catalyst; simple treatment with acidic water gave colorless polymers visually free from metal residues (>97 % removal; <64 ppm).
A national assessment of the sensitivity of Australian runoff to climate change
Authors: Preston B. L. , Jones R. 
Published: July 2008

AbstractThe relationship between catchment rainfall, evapotranspiration and runoff can be exploited to assess climate risk to water resources. National data regarding climatology and runoff were used to estimate the sensitivity of regional runoff to projected changes in precipitation and evaporation. These sensitivity factors were integrated with patterns of climate change from 12 different global climate model (GCM) simulations to project future annual runoff sensitivity per degree of global mean temperature change. Divergent runoff sensitivities were identified depending upon the selected GCM. Averaging among GCMs resulted in a robust pattern of runoff sensitivity suitable for estimating future climate risk. Copyright © 2008 Royal Meteorological Society
Dividend payments in the classical risk model under absolute ruin with debit interest
Authors: Wang Chunwei , Yin Chuancun 
Published: July 2008

AbstractThis paper attempts to study the dividend payments in a compound Poisson surplus process with debit interest. Dividends are paid to the shareholders according to a barrier strategy. An alternative assumption is that business can go on after ruin, as long as it is profitable. When the surplus is negative, a debit interest is applied. At first, we obtain the integro‐differential equations satisfied by the moment‐generating function and moments of the discounted dividend payments and we also prove the continuous property of them at zero. Then, applying these results, we get the explicit expressions of the moment‐generating function and moments of the discounted dividend payments for exponential claims. Furthermore, we discuss the optimal dividend barrier when the claim sizes have a common exponential distribution. Finally, we give the numerical examples for exponential claims and Erlang (2) claims. Copyright © 2008 John Wiley & Sons, Ltd.