bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perfluorinated coatings and terracotta: An impregnation study
Authors: Youssef Ali , Pabon Martial , Woelflé Emmanuel , Severac Romain , Gilbert Robert G. 
Published: July 2008

AbstractThe mechanisms of penetration onto terracotta of two commercially available perfluorinated acrylates were studied: Zonyl®225, a solvent‐based perfluorinated polyacrylate containing two unfluorinated acrylic or vinylic monomers; and Zonyl®329, an aqueous dispersion synthesized from comparable monomers plus a vinylic silane. Two application methods were used: by immersion of the substrate for 15 h and by multiple brush strokes, with pauses between strokes. Application effectiveness was assessed by measuring the depth of penetration into terracotta. The results of coating were examined by optical and electron microscopy, including elemental analysis. When the impregnating agent was applied by extended immersion, both solvent‐based and aqueous dispersion exhibited higher penetration depths with increasing concentrations. When applied using multiple brush strokes, the solvent‐based solution exhibited the same trend as that in immersion; however, the aqueous dispersion showed no penetration beyond ∼ 0.12 mm. This limited depth of penetration is shown to be a result of partial drying between brush strokes, but also as a result of porosity restrictions and electrostatic interactions between the positively charged polymer colloids in the dispersion and the negatively charged terracotta surface. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of hypochlorite treatment on performance of hollow fiber membrane prepared from polyethersulfone/N‐methyl‐2‐pyrrolidone/tetronic 1307 solution
Authors: Arahman Nasrul , Maruyama Tatsuo , Sotani Tomohiro , Matsuyama Hideto 
Published: July 2008

AbstractPolyethersulfone (PES) hollow fiber membrane was prepared by blending with nonionic surfactant Tetronic 1307 to improve its hydrophilicity. The membranes were posttreated by hypochlorite solution of 10, 100, 500, and 2000 ppm. The effect of hypochlorite treatment on the performance of PES membrane was investigated. Experimental results showed that the water permeability of treated membrane was two to three times higher than that of untreated membrane in case of blend membrane prepared from PES/N‐methyl‐2‐pyrrolidone (NMP)/Tetronic 1307 solution. On the other hand, hypochlorite treatment has no effect on water permeability of the membrane prepared from PES/NMP solution. Elemental analysis and ATR–FTIR measurement results indicated that hypochlorite treatment led to decomposition and leaching out of Tetronic 1307 component from the membrane. The change of membrane surface structure by the hypochlorite treatment was confirmed by atomic force microscopy measurement. The hypochlorite treatment brought about no significant impact on the mechanical property of the membranes. This indicated that the hypochlorite treatment of PES membrane prepared with surfactant was a useful way to improve the water permeability without the decrease of membrane strength. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of the structure of silane‐coupling agent on dynamic mechanical properties of dental resin‐nanocomposites
Authors: Sideridou Irini D. , Karabela Maria M. 
Published: July 2008

AbstractThis work was aimed at the study by dynamic mechanical analysis (DMA) of dental composites consisted of a Bis‐GMA/TEGDMA (50/50 wt/wt) matrix and silica nanoparticles (Aerosil OX50) as filler, silanized with various silanes. The silanes used were 3‐[(1,3(2)‐dimethacryloyloxypropyl)‐2 (3)‐oxycarbonylamido] propyltriethoxy‐silane (UDMS), 3‐methacryloxypropyl‐trimethoxysilane (MPS), octyltrimethoxysilane (OTMS), blends of UDMS/OTMS (50/50 wt/wt), or MPS/OTMS (50/50 wt/wt). The total amount of silane was kept constant at 10% by weight fraction relative to the filler weight. The silanized nanoparticles were mixed with the dimethacrylate matrix (60% filler by weight fraction). The composites were light cured and tested by DMA for the determination of storage modulus (E′), loss modulus (E″), tangent delta (tan δ), and glass transition temperature (Tg). Measurements were performed in samples immediately after curing and samples stored in water at 37°C for 1, 7, 30, or 120 days. OTMS‐composite in which OTMS does not form covalent bond with the dimethacrylate matrix showed lower elastic modulus both in dry and wet conditions. The ability of bifunctional UDMS for crosslinking was found not to increase the elastic behavior of the composite, as it was expected, compared with that of MPS‐composite, because of the high amount of the silane used. After immersion in water the elastic modulus of OTMS‐composite remained constant, while that of the other composites increased after 1 day and then remained constant up to 120 days. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
2,2‐Bis[4‐(3,4‐dicarboxyphenoxy) phenyl]propane dianhydride (BPADA)‐based polyimide membranes for pervaporation dehydration of isopropanol: Characterization and comparison with 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride (6FDA)‐based polyimide membranes
Authors: Xiao Shude , Feng Xianshe , Huang Robert Y. M. 
Published: July 2008

AbstractPolyimides were synthesized from one‐step polycondensation of BPADA and various diamines and were characterized with GPC, FTIR, NMR, DSC, and TGA. Polyimide membranes were prepared, and their hydrophilicity was estimated by contact angles and the free energies of interfacial interactions. Pervaporation properties were investigated for the dehydration of isopropanol, and comparisons were made between BPADA‐based membranes and 6FDA‐based membranes. The concentration coefficients of BPADA‐based membranes were calculated from the linear moiety contribution method based on the results from 6FDA‐based membranes, and they were compared to understand the effects of the feed concentration on pervaporation properties. The effects of temperature on permeation flux were studied with permeation activation energies for total flux and water flux in permeates. Moiety contribution factors for activation energies were used to correlate permeation flux and monomer moieties in the polymers, and reasonable results were obtained for BPADA. It is revealed that steric effects of monomers may change the diffusion properties, while functional groups are favorable to the changes in sorption properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Genomic organization of thepara‐sodium channel α‐subunit genes from the pyrethroid‐resistant and ‐susceptible strains of the diamondback moth
Authors: Sonoda Shoji , Tsukahara Yoshitaka , Ashfaq Muhammad , Tsumuki Hisaaki 
Published: July 2008

AbstractWe examined the genomic organization of thepara‐sodium channel α‐subunit gene of the diamondback moth,Plutella xylostella(L.). The nucleotide sequence contained 34 putative exons, which covered almost the entire coding region of the gene producing 1,889 amino acid residues. Deduced amino acid identity to thehscplocus ofHeliothis virescenswas 84%. Comparison of deduced amino acid sequences of the permethrin‐resistant and ‐susceptible strains showed two substitutions other thankdrandsuper‐kdr‐like substitutions. They were Ala to Thr (A1060T) and Pro to Ser (P1836S) at the linker region of the domains II–III and the carboxyl terminus, respectively. Furthermore, we developed PCR amplification protocols for the rapid detection of both substitutions. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.
Characterization ofAnopheles minimusCYP6AA3 expressed in a recombinant baculovirus system
Authors: Boonsuepsakul Soamrutai , Luepromchai Ekawan , Rongnoparut Pornpimol 
Published: July 2008

AbstractMetabolism by cytochrome P450 monooxygenases is a major mechanism implicated in resistance of insects to insecticides, including pyrethroids. We previously isolated the cytochrome P450 CYP6AA3 from deltamethrin‐selected resistant strain ofAnopheles minimusmosquito, a major malaria vector in Thailand. In the present study, we further investigated the role of CYP6AA3 enzyme in deltamethrin metabolism in vitro. The CYP6AA3 was expressed inSpodoptera frugiperda(Sf9) insect cells via baculovirus‐mediated expression system. The enzymatic activity of CYP6AA3 in deltamethrin metabolism was characterized after being reconstituted withAn. minimusNADPH‐cytochrome P450 reductase and a NADPH‐regenerating system. The contribution of CYP6AA3 responsible for deltamethrin metabolism was determined by measurement of deltamethrin disappearance following the incubation period and deltamethrin‐derived compounds were detected using combined gas chromatography mass spectrometry analysis. 3‐Phenoxybenzaldehyde was a major product of CYP6AA3‐mediated deltamethrin metabolism. Deltamethrin degradation and formation of metabolites were NADPH‐dependent and inhibited by piperonyl butoxide. Deltamethrin was catalyzed by CYP6AA3 with an apparentKmof 80.0 ± 2.0 andVmaxof 60.2 ± 3.6 pmol/min/pmol P450. Furthermore, deltamethrin cytotoxicity assays by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) and trypan blue dye exclusion were examined in Sf9 insect cells, with and without expression of CYP6AA3. Results revealed that CYP6AA3 could play a role in detoxifying deltamethrin in the cells. Thus, the results of this study support the role of CYP6AA3 in deltamethrin metabolism. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.
Aflatoxin B1 detoxification by CYP321A1 in Helicoverpa zea
Authors: Niu Guodong , Wen Zhimou , Rupasinghe Sanjeewa G. , Zeng Ren Sen , Berenbaum May R. , Schuler Mary A. 
Published: July 2008

AbstractThe polyphagous corn earworm Helicoverpa zea frequently encounters aflatoxins, mycotoxins produced by the pathogens Aspergillus flavus and A. parasiticus, which infect many of this herbivore's host plants. While aflatoxin B1 metabolism by midgut enzymes isolated from fifth instars feeding on control diets was not detected, this compound was metabolized by midgut enzymes isolated from larvae consuming diets supplemented with xanthotoxin, coumarin, or indole‐3‐carbinol, phytochemicals that are likely to co‐occur with aflatoxin in infected host plants. Of the two metabolites generated, the main derivative identified in midguts induced with these chemicals and in reactions containing heterologously expressed CYP321A1 was aflatoxin P1 (AFP1), an O‐demethylated product of AFB1. RT‐PCR gel blots indicated that the magnitude of CYP321A1 transcript induction by these chemicals is associated with the magnitude of increase in the metabolic activities of induced midgut enzymes (coumarin>xanthotoxin>indole 3‐carbinol). These results indicate that induction of P450s, such as CYP321A1, plays an important role in reducing AFB1 toxicity to H. zea. Docking of AFB1 in the molecular models of CYP321A1 and CYP6B8 highlights differences in their proximal catalytic site volumes that allow only CYP321A1 to generate the AFP1 metabolite. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.
The citation advantage of open‐access articles
Authors: Norris Michael , Oppenheim Charles , Rowland Fytton 
Published: July 2008

AbstractFour subjects—ecology, applied mathematics, sociology, and economics—were selected to assess whether there is a citation advantage between journal articles that have an open‐access (OA) version on the Internet compared to those articles that are exclusively toll access (TA). Citations were counted using the Web of Science, and the OA status of articles was determined by searching OAIster, OpenDOAR, Google, and Google Scholar. Of a sample of 4,633 articles examined, 2,280 (49%) were OA and had a mean citation count of 9.04 whereas the mean for TA articles was 5.76. There appears to be a clear citation advantage for those articles that are OA as opposed to those that are TA. This advantage, however, varies between disciplines, with sociology having the highest citation advantage, but the lowest number of OA articles, from the sample taken, and ecology having the highest individual citation count for OA articles, but the smallest citation advantage. Tests of correlation or association between OA status and a number of variables were generally found to weak or inconsistent. The cause of this citation advantage has not been determined.
Information organization and retrieval using a topic maps‐based ontology: Results of a task‐based evaluation
Authors: Yi Myongho 
Published: July 2008

AbstractAs information becomes richer and more complex, alternative information‐organization methods are needed to more effectively and efficiently retrieve information from various systems, including the Web. The objective of this study is to explore how a Topic Maps‐based ontology approach affects users' searching performance. Forty participants participated in a task‐based evaluation where two dependent variables, recall and search time, were measured. The results of this study indicate that a Topic Maps‐based ontology information retrieval (TOIR) system has a significant and positive effect on both recall and search time, compared to a thesaurus‐based information retrieval (TIR) system. These results suggest that the inclusion of a Topic Maps‐based ontology is a beneficial approach to take when designing information retrieval systems.
Selecting manuscripts for a high‐impact journal through peer review: A citation analysis of communications that were accepted by Angewandte Chemie International Edition, or rejected but published elsewhere
Authors: Bornmann Lutz , Daniel Hans‐Dieter 
Published: July 2008

AbstractAll journals that use peer review have to deal with the following question: Does the peer review system fulfill its declared objective to select the “best” scientific work? We investigated the journal peer‐review process at Angewandte Chemie International Edition (AC‐IE), one of the prime chemistry journals worldwide, and conducted a citation analysis for Communications that were accepted by the journal (n = 878) or rejected but published elsewhere (n = 959). The results of negative binomial‐regression models show that holding all other model variables constant, being accepted by AC‐IE increases the expected number of citations by up to 50%. A comparison of average citation counts (with 95% confidence intervals) of accepted and rejected (but published elsewhere) Communications with international scientific reference standards was undertaken. As reference standards, (a) mean citation counts for the journal set provided by Thomson Reuters corresponding to the field “chemistry” and (b) specific reference standards that refer to the subject areas of Chemical Abstracts were used. When compared to reference standards, the mean impact on chemical research is for the most part far above average not only for accepted Communications but also for rejected (but published elsewhere) Communications. However, average and below‐average scientific impact is to be expected significantly less frequently for accepted Communications than for rejected Communications. All in all, the results of this study confirm that peer review at AC‐IE is able to select the “best” scientific work with the highest impact on chemical research.
Main‐path analysis and path‐dependent transitions in HistCite™‐based historiograms
Authors: Lucio‐Arias Diana , Leydesdorff Loet 
Published: July 2008

AbstractWith the program HistCite™ it is possible to generate and visualize the most relevant papers in a set of documents retrieved from the Science Citation Index. Historical reconstructions of scientific developments can be represented chronologically as developments in networks of citation relations extracted from scientific literature. This study aims to go beyond the historical reconstruction of scientific knowledge, enriching the output of HistCite™ with algorithms from social‐network analysis and information theory. Using main‐path analysis, it is possible to highlight the structural backbone in the development of a scientific field. The expected information value of the message can be used to indicate whether change in the distribution (of citations) has occurred to such an extent that a path‐dependency is generated. This provides us with a measure of evolutionary change between subsequent documents. The “forgetting and rewriting” of historically prior events at the research front can thus be indicated. These three methods—HistCite, main path and path dependent transitions—are applied to a set of documents related to fullerenes and the fullerene‐like structures known as nanotubes.
Visualization of health‐subject analysis based on query term co‐occurrences
Authors: Zhang Jin , Wolfram Dietmar , Wang Peiling , Hong Yi , Gillis Rick 
Published: July 2008

AbstractA multidimensional‐scaling approach is used to analyze frequently used medical‐topic terms in queries submitted to a Web‐based consumer health information system. Based on a year‐long transaction log file, five medical focus keywords (stomach, hip, stroke, depression, and cholesterol) and their co‐occurring query terms are analyzed. An overlap‐coefficient similarity measure and a conversion measure are used to calculate the proximity of terms to one another based on their co‐occurrences in queries. The impact of the dimensionality of the visual configuration, the cutoff point of term co‐occurrence for inclusion in the analysis, and the Minkowski metric power k on the stress value are discussed. A visual clustering of groups of terms based on the proximity within each focus‐keyword group is also conducted. Term distributions within each visual configuration are characterized and are compared with formal medical vocabulary. This investigation reveals that there are significant differences between consumer health query‐term usage and more formal medical terminology used by medical professionals when describing the same medical subject. Future directions are discussed.
Robust Tris‐Cyclometalated Iridium(III) Phosphors with Ligands for Effective Charge Carrier Injection/Transport: Synthesis, Redox, Photophysical, and Electrophosphorescent Behavior
Authors: Zhou Guijiang , Wang Qi , Ho Cheuk‐Lam , Wong Wai‐Yeung , Ma Dongge , Wang Lixiang , Lin Zhenyang 
Published: July 2008

AbstractWith the target to design and develop new functionalized green triplet light emitters that possess distinctive electronic properties for robust and highly efficient phosphorescent organic light‐emitting diodes (PHOLEDs), a series of bluish–green to yellow–green phosphorescent tris‐cyclometalated homoleptic iridium(III) complexes [Ir(ppy‐X)3] (X=SiPh3, GePh3, NPh2, POPh2, OPh, SPh, SO2Ph, Hppy=2‐phenylpyridine) have been synthesized and fully characterized by spectroscopic, redox, and photophysical methods. By chemically manipulating the lowest triplet‐state character of Ir(ppy)3 with some functional main‐group 14–16 moieties on the phenyl ring of ppy, a new family of metallophosphors with high‐emission quantum yields, short triplet‐state lifetimes, and good hole‐injection/hole‐transporting or electron‐injection/electron‐transporting properties can be obtained. Remarkably, all of these IrIII complexes show outstanding electrophosphorescent performance in multilayer doped devices that surpass that of the state‐of‐the‐art green‐emitting dopant Ir(ppy)3. The devices described herein can reach the maximum external quantum efficiency (ηext) of 12.3 %, luminance efficiency (ηL) of 50.8 cd A−1, power efficiency (ηp) of 36.9 Lm W−1 for [Ir(ppy‐SiPh3)3], 13.9 %, 60.8 cd A−1, 49.1 Lm W−1 for [Ir(ppy‐NPh2)3], and 10.1 %, 37.6 cd A−1, 26.1 Lm W−1 for [Ir(ppy‐SO2Ph)3]. These results provide a completely new and effective strategy for carrier injection into the electrophosphor to afford high‐performance PHOLEDs suitable for various display applications.
Mono‐ and Dinuclear Palladium(II) N,S‐Heterocyclic Carbene Complexes with N Spacers and their Suzuki Coupling Activities
Authors: Yen Swee Kuan , Koh Lip Lin , Huynh Han Vinh , Hor T. S. Andy 
Published: July 2008

AbstractMixed‐ligand N,S‐heterocyclic carbene (NSHC) complexes, trans‐[PdBr2(NSHC)(Py)] (NSHC=3‐benzyl‐ or 3‐propyl‐benzothiazolin‐2‐ylidene), have been obtained from bridge‐cleavage reactions of the dinuclear complex, [Pd(μ‐Br)Br(NSHC)]2, in pyridine at room temperature. Use of neutral N‐bidentate donors (L=pyrazine, 1,2‐bis(4‐pyridyl)ethane, 4,4′‐bipyridine and trans‐1,2‐bis(4‐pyridyl)ethylene) yields the dinuclear spacer‐bridged [Pd2Br4(NSHC)2(μ‐L)] complexes. The X‐ray single‐crystal structures of the pyridyl, bridging pyrazine and 1,2‐bis(4‐pyridyl)ethane complexes are reported. These air‐stable complexes are active in the Suzuki–Miyaura coupling reactions of selected aryl bromides. The dinuclear complexes are generally more active than their mononuclear pyridyl analogues. The benzyl derivatives consistently outperform the n‐propyl counterparts.
Optimal predictive densities and fractional moments
Authors: Taufer Emanuele , Bose Sudip , Tagliani Aldo 
Published: July 2008

AbstractThe maximum entropy approach used together with fractional moments has proven to be a flexible and powerful tool for density approximation of a positive random variable. In this paper we consider an optimality criterion based on the Kullback–Leibler distance in order to select appropriate fractional moments. We discuss the properties of the proposed procedure when all the available information comes from a sample of observations. The method is applied to the size distribution of the U.S. family income. Copyright © 2008 John Wiley & Sons, Ltd.
MECP2 promoter methylation and X chromosome inactivation in autism
Authors: Nagarajan Raman P. , Patzel Katherine A. , Martin Michelle , Yasui Dag H. , Swanberg Susan E. , Hertz‐Picciotto Irva , Hansen Robin L. , Van de Water Judy , Pessah Isaac N. , Jiang Ruby , Robinson Wendy P. , LaSalle Janine M. 
Published: July 2008

AbstractEpigenetic mechanisms have been proposed to play a role in the etiology of autism. This hypothesis is supported by the discovery of increased MECP2 promoter methylation associated with decreased MeCP2 protein expression in autism male brain. To further understand the influence of female X chromosome inactivation (XCI) and neighboring methylation patterns on aberrant MECP2 promoter methylation in autism, multiple methylation analyses were performed on brain and blood samples from individuals with autism. Bisulfite sequencing analyses of a region 0.6 kb upstream of MECP2 in brain DNA samples revealed an abrupt transition from a highly methylated region in both sexes to a region unmethylated in males and subject to XCI in females. Chromatin immunoprecipitation analysis demonstrated that the CCCTC‐binding factor (CTCF) is bound to this transition region in neuronal cells, consistent with a chromatin boundary at the methylation transition. Male autism brain DNA samples displayed a slight increase in methylation in this transition region, suggesting a possible aberrant spreading of methylation into the MECP2 promoter in autism males across this boundary element. In addition, autistic female brain DNA samples showed evidence for aberrant MECP2 promoter methylation as an increase in the number of bisulfite sequenced clones with undefined XCI status for MECP2 but not androgen receptor (AR). To further investigate the specificity of MECP2 methylation alterations in autism, blood DNA samples from females and mothers of males with autism were also examined for XCI skewing at AR, but no significant increase in XCI skewing was observed compared to controls. These results suggest that the aberrant MECP2 methylation in autism brain DNA samples is due to locus‐specific rather than global X chromosome methylation changes.