bluuebunny/crossref_metadata_2025 huggingface dataset:
THE ECONOMICS OF ENTOMOLOGICAL EFFORT: OVERVIEW AND RECOMMENDATIONS
Authors: McEwen F.L.
Published: December 2009

In opening the symposium, I referred to 3 reasons why I felt the symposium was so important and why I was pleased to participate in it. The first of these reasons was our need to define the benefits of entomology in economic terms so that we could make our case for funding. This point was made repeatedly. Those allocating resources see many outstretched hands. The public demands return on investments. If we are to be successful in having funds allotted to entomology, we must justify these in terms of real return to society.
EVALUATION OF MONITORING TECHNIQUES FOR THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (COLEOPTERA: CURCULIONIDAE)
Authors: Boivin Guy
Published: December 2009

Five trap designs were evaluated for their efficiency in capturing overwintering adults of the carrot weevil, Listronotus oregonensis (Le Conte). Trap catches were compared with counts of oviposition and nutrition cavities found in carrots placed on the ground. A trap consisting of 22 wooden plates, separated by metal washers and placed over a carrot which was used as bait, proved to be the most efficient. The weevils crawl between the plates, feed on the carrot, and are collected by dismantling the trap over a pan. This technique provided a seasonal record of carrot-weevil activity comparable to that obtained with carrot sections and can be used to issue insecticide-treatment recommendations prior to the beginning of the carrot-weevil oviposition period.
RELATIONSHIP BETWEEN PARASITISM OF LARCH CASEBEARER (LEPIDOPTERA: COLEOPHORIDAE) AND DEAD HOSTS IN THE BLUE MOUNTAINS, 1973–1983
Authors: Ryan Roger B.
Published: December 2009

Between 1973 and 1983 two newly introduced parasites, Agathis pumila (Ratz.) and Chrysocharis laricinellae (Ratz.), caused an increasing impact on populations of the larch casebearer, Coleophora laricella (Hbn.), as measured by percentage parasitism based on adult emergence and the associated mortality of hosts that did not produce parasites. Total impact of the parasites cannot be measured by adult emergence alone but must include parasite-killed hosts from which no parasites emerged. Nevertheless, trends in parasite effectiveness are represented by percentages based solely on adult emergence. Only 53.1% of the adult A. pumila successfully emerged in 1983 samples. Furthermore, the number of emerged plus non-emerged A. pumila was only 53.3% of the number expected based on previous samples of that same generation. This mortality of A. pumila took place even in the absence of significant populations of C. laricinellae, indicating that although C. laricinellae may cause some reduction in parasitism by A. pumila, other factors are also responsible.
IMPACT OF FEEDING BY LEPIDOPTERA LARVAE ON THE PRODUCTION OF HIGHBUSH BLUEBERRY IN THE LOWER FRASER VALLEY, BRITISH COLUMBIA
Authors: Gillespie David R.
Published: December 2009

Lepidoptera larvae on highbush blueberry fed more frequently in flower and fruit clusters than in leafrolls during April, May, and early June. Their feeding reduced the harvest from individual clusters to about half of that of undamaged clusters. Larval feeding caused losses of production in blueberry fields of from 2.5 to 7% depending on leafroller densities. Insecticide treatments in experimental plots decreased leafroller populations and increased cluster yields.
IL-15 Regulates Both Quantitative and Qualitative Features of the Memory CD8 T Cell Pool
Authors: Sandau Michelle M. , Kohlmeier Jacob E. , Woodland David L. , Jameson Stephen C.
Published: December 2009

Memory T cells are critical for immunity to various intracellular pathogens. Recent studies have indicated that CD8 secondary memory cells, induced by prime-boost approaches, show enhanced protective function compared with primary memory cells and exhibit phenotypic and functional characteristics that distinguish them from primary memory cells. However, little is known about the cytokine requirements for generation and maintenance of boosted memory CD8 T cells. We studied the role of IL-15 in determining the size and composition of the secondary (2°) memory CD8 T cell pool induced by Listeria monocytogenes infection in mice. Following boosting, IL-15–deficient animals failed to generate a subset of CD8 effector memory cells, including a population of IL-7Rαlow cells, which were prominent among secondary memory cells in normal mice. IL-15 deficiency also resulted in changes within the IL-7RαhighCD62Llow subset of 2° memory CD8 T cells, which expressed high levels of CD27 but minimal granzyme B. In addition to these qualitative changes, IL-15 deficiency resulted in reduced cell cycle and impaired Bcl-2 expression by 2° memory CD8 T cells, suggesting a role for IL-15 in supporting both basal proliferation and survival of the pool. Analogous qualitative differences in memory CD8 T cell populations were observed following a primary response to Sendai virus in IL-15−/− animals. Collectively, these findings demonstrate that IL-15 plays an important role in dictating the composition rather than simply the maintenance of the CD8 memory pool.
Phagocytosis of Apoptotic Cells by Neutrophil Granulocytes: Diminished Proinflammatory Neutrophil Functions in the Presence of Apoptotic Cells
Authors: Esmann Lars , Idel Christian , Sarkar Arup , Hellberg Lars , Behnen Martina , Möller Sonja , van Zandbergen Ger , Klinger Matthias , Köhl Jörg , Bussmeyer Uta , Solbach Werner , Laskay Tamás
Published: December 2009

Neutrophil granulocytes are rapidly recruited from the bloodstream to the site of acute inflammation where they die in large numbers. Because release of toxic substances from dead neutrophils can propagate the inflammatory response leading to tissue destruction, clearance of dying inflammatory neutrophils has a critical function in the resolution of the inflammatory response. Apoptotic neutrophils are phagocytosed primarily by macrophages, provided these cells are present in adequate numbers. However, macrophages are rare at sites of acute inflammation, whereas the number of neutrophils can be extremely high. In the current study, in vitro experiments with human neutrophils were carried out to investigate whether neutrophils can ingest apoptotic neutrophils. We show that naïve granulocytes isolated from venous blood have a limited capacity to phagocytose apoptotic cells. However, exposure to activating stimuli such as LPS, GM-CSF and/or IFN-γ results in enhanced phagocytosis of apoptotic cells. The efficient uptake of apoptotic cells by neutrophils was found to depend on the presence of heat labile serum factors. Importantly, the contact to or uptake of apoptotic cells inhibited neutrophil functions such as respiratory burst and the release of the proinflammatory cytokines TNF-α and interferon-inducible protein-10. Contact to apoptotic cells, however, induced the secretion of IL-8 and growth-related oncogene-α, which was independent of NF-κB and p38 MAPK but involved C5a and the ERK1/2 pathway. The data suggest that activated neutrophils participate in the clearance of apoptotic cells. In addition, because apoptotic cells inhibit proinflammatory functions of neutrophils, uptake of apoptotic cells by neutrophils contributes to the resolution of inflammation.
Marginal Zone Precursor B Cells as Cellular Agents for Type I IFN–Promoted Antigen Transport in Autoimmunity
Authors: Wang, John H. , Li Jun , Wu Qi , Yang PingAr , Pawar Rahul D. , Xie Shutao , Timares Laura , Raman Chander , Chaplin David D. , Lu Lu , Mountz John D. , Hsu Hui-Chen
Published: December 2009

The pathogenic connection of type I IFN and its role in regulating the migration response of Ag delivery by B cells into lymphoid follicles in an autoimmune condition has not been well-identified. Here, we show that there was a significantly larger population of marginal zone precursor (MZ-P) B cells, defined as being IgMhiCD1dhiCD21hiCD23hi in the spleens of autoimmune BXD2 mice compared with B6 mice. MZ-P B cells were highly proliferative compared with marginal zone (MZ) and follicular (FO) B cells. The intrafollicular accumulation of MZ-P B cells in proximity to germinal centers (GCs) in BXD2 mice facilitated rapid Ag delivery to the GC area, whereas Ag-carrying MZ B cells, residing predominantly in the periphery, had a lower ability to carry Ag into the GCs. IFN-α, generated by plasmacytoid dendritic cells, induced the expression of CD69 and suppressed the sphingosine-1-phosphate-induced chemotactic response, promoting FO-oriented Ag transport by MZ-P B cells. Knockout of type I IFN receptor in BXD2 (BXD2-Ifnαr−/−) mice substantially diffused the intrafollicular MZ-P B cell conglomeration and shifted their location to the FO-MZ border near the marginal sinus, making Ag delivery to the FO interior less efficient. The development of spontaneous GCs was decreased in BXD2-Ifnαr−/− mice. Together, our results suggest that the MZ-P B cells are major Ag-delivery B cells and that the FO entry of these B cells is highly regulated by type I IFN–producing plasmacytoid dendritic cells in the marginal sinus in the spleens of autoimmune BXD2 mice.
MART-1–Specific Melanoma Tumor-Infiltrating Lymphocytes Maintaining CD28 Expression Have Improved Survival and Expansion Capability Following Antigenic Restimulation In Vitro
Authors: Li Yufeng , Liu Shujuan , Hernandez Jessica , Vence Luis , Hwu Patrick , Radvanyi Laszlo
Published: December 2009

We determined how CD8+ melanoma tumor–infiltrating lymphocytes (TILs) isolated from two distinct phases of expansion in preparation for adoptive T cell therapy respond to melanoma Ag restimulation. We found that TILs isolated after the rapid expansion protocol (REP) phase, used to generate the final patient TIL infusion product, were hyporesponsive to restimulation with MART-1 peptide-pulsed dendritic cells, with many CD8+ T cells undergoing apoptosis. Telomere length was shorter post-REP, but of sufficient length to support further cell division. Phenotypic analysis revealed that cell-surface CD28 expression was significantly reduced in post-REP TILs, whereas CD27 levels remained unchanged. Tracking post-REP TIL proliferation by CFSE dilution, as well as sorting for CD8+CD28+ and CD8+CD28− post-REP subsets, revealed that the few CD28+ TILs remaining post-REP had superior survival capacity and proliferated after restimulation with MART-1 peptide. An analysis of different supportive cytokine mixtures during the REP found that a combination of IL-15 and IL-21 facilitated comparable expansion of CD8+ TILs as IL-2, but prevented the loss of CD28 expression with improved responsiveness to antigenic restimulation post-REP. These results suggest that current expansion protocols using IL-2 for melanoma adoptive T cell therapy yields largely CD8+ T cells unable to persist and divide in vivo following Ag contact. The few CD8+CD28+ T cells that remain may be the only CD8+ TILs that ultimately survive to repopulate the host and mediate long-term tumor control. A REP protocol using IL-15 and IL-21 may greatly increase the number of CD28+ TILs capable of long-term persistence.
Occupational immediate‐type asthma and rhinitis due to rhodium salts
Authors: Merget Rolf , Sander Ingrid , van Kampen Vera , Raulf‐Heimsoth Monika , Ulmer Hans‐Martin , Kulzer Rupprecht , Bruening Thomas
Published: December 2009

Background

Whereas platinum salts are well known occupational allergens, rhodium salts have not been identified as inhalative sensitizing substances.

Methods

A 27‐year‐old atopic operator of an electroplating plant developed work‐related shortness of breath and runny nose with sneezing after exposure to rhodium salts. Quantitative skin prick tests (SPT) and bronchial challenge tests with a dosimeter protocol were performed with quadrupling doses of the sodium chloride salts of rhodium (Na3RhCl6) and platinum (Na2PtCl6).

Results

The patient showed positive SPT reactions and positive bronchial immediate‐type reactions with rhodium and platinum salts. Sensitivity to rhodium salt was much higher than to platinum salt; the molar concentrations differed by a factor of 256 in SPT and a factor of 16 in bronchial challenges.

Conclusions

Rhodium salts should be considered as occupational immediate‐type allergens. Am. J. Ind. Med. 53:42–46. 2010. © 2009 Wiley‐Liss, Inc.
Three stones for three seeds: natural occurrence of selective tool use by capuchins (Cebus libidinosus) based on an analysis of the weight of stones found at nutting sites
Authors: Ferreira Renata G. , Emidio Ricardo Almeida , Jerusalinsky Leandro
Published: December 2009

Capuchins (Cebus libidinosus) occupy areas of Caatinga in northeast Brazil. They consume the nuts of several species of difficult‐to‐open fruits (two species of Palmae and one species of Euphorbiacea) and are reported to use stones as hammers to crack open the nuts. This article describes the weight of hammers found on anvils and presumably used for nut‐cracking by individuals in two groups of wild unprovisioned capuchin monkeys. Hammer weights ranged from less than 200 to over 3 kg. Based on a correlation between the type of broken nuts found at a site and the stones present on anvils, there was evidence that hammer weight differed according to nut size. These findings are consistent with experimental data recently published by Visalberghi et al. [Current Biology 19, 2009, DOI: 10.1016/j.cub.2008.11.064] and indicate that capuchins are capable of choosing stones of appropriate weight to effectively use pounding tools in natural environments without interference from humans. Am. J. Primatol. 72:270–275, 2010. © 2009 Wiley‐Liss, Inc.
Are howler monkey species ecologically equivalent? Trophic niche overlap in syntopicAlouatta guariba clamitansandAlouatta caraya
Authors: Agostini Ilaria , Holzmann Ingrid , Di Bitetti Mario S.
Published: December 2009

According to the principle of competitive exclusion, niche differentiation allows the stable coexistence of closely related species. We analyzed dietary profile and diversity, and dietary overlap between syntopic brown howlers (BR;Alouatta guariba clamitans) and black and gold howlers (BLG;A. caraya) in the Atlantic Forest of NE Argentina, with the objective of evaluating the degree of trophic niche overlap and potential interspecific competition for food. During 12 months, we collected data on feeding behavior of two groups of each howler species using the scan sampling method, together with data on food availability. Both at the group‐ and species‐level, we analyzed feeding behavior in terms of monthly percentages of time spent feeding on each food type and specific food item, dietary diversity (Shannon indexH′), and we estimated dietary overlap using the percentage index and the Morisita–Horn index (CH). Across months, both howlers showed species‐specific preferences for certain food items, and BLG had a more diverse diet (mean±SE,H′=2.77±0.08) than BR (H′=2.39±0.09). However, diets of both species overlapped extensively (percentage index=45.64±2.97%;CH=0.6±0.05) and diets of conspecific groups did not overlap more than diets of groups of different species. Given their high degree of trophic overlap, syntopic BR and BLG meet one of the conditions necessary for interspecific food competition to occur. Although at present we lack direct evidence for interspecific competition in these howler species, we conclude that high levels of niche overlap may have an important role in maintaining the essentially parapatric distribution of howler species throughout the Neotropics. Am. J. Primatol. 72:173–186, 2010. © 2009 Wiley‐Liss, Inc.
Patterns of systemic stress during the agricultural transition in prehistoric Japan
Authors: Temple Daniel H.
Published: December 2009

This study documents and interprets systemic stress during the agricultural transition in prehistoric Japan using linear enamel hypoplasia (LEH) defects and cribra orbitalia (CO) lesions. Middle to Final Jomon cultures (5000–2300 BP) from Honshu Island represent the foraging samples, while Yayoi cultures (2500–1700 BP) represent the early agricultural samples. Jomon foragers from eastern Japan had broad‐based, intensive economies. Jomon foragers from western Japan had a greater focus on seasonally available, nutritionally poor resources, while Yayoi people were descendents of migrants from the East Asian continent and introduced wet rice economies to Japan. This study tests the hypotheses that wet rice economies will be associated with a lower prevalence of teeth/individuals affected by LEH defects in western Japan, while few differences in the prevalence of teeth/individuals with LEH defects will be observed between eastern Jomon people and Yayoi farmers. It is further predicted that similar CO prevalence will be observed between Jomon and Yayoi people given environmental similarities. Significantly greater frequencies of teeth affected by LEH defects are observed among western Jomon compared to Yayoi people. The prevalence of teeth with LEH defects is slightly elevated among eastern Jomon foragers compared to Yayoi agriculturalists. Significant differences in CO prevalence are not observed. Systemic stress prevalence in western Japan likely declined following wet‐rice agriculture because this crop provided a predictable, renewable resource base. Systemic stress prevalence was similar between eastern Jomon and Yayoi people because both groups practiced intensive subsistence strategies. Similar CO prevalence reflects infectious diseases associated with living conditions. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.
Brief communication: Population variation in human maxillary premolar accessory ridges (MxPAR)
Authors: Burnett Scott E. , Hawkey Diane E. , Turner Christy G.
Published: December 2009

The purpose of this brief communication is to report the results of an analysis of maxillary premolar accessory ridges (MxPAR), a common but understudied accessory ridge that may occur both mesial and distal to the central ridge of the buccal cusp of upper premolars. We developed a new five‐grade scoring plaque to better categorize MxPAR variation. Subsequently, we conducted a population analysis of MxPAR frequency in 749 dental casts of South African Indian, American Chinese, Alaskan Eskimo, Tohono O'odham (Papago), Akimel O'odham (Pima), Solomon Islander, South African Bantu, and both American and South African Whites. Northeast Asian and Asian‐derived populations exhibited the highest MxPAR frequencies while Indo‐European samples (South African Indians, American and South African Whites) exhibited relatively low frequencies. The Solomon Islanders and South African Bantu samples exhibited intermediate frequencies. Our analysis indicates that statistically significant differences in MxPAR frequency exist between major geographic populations. As a result, the MxPAR plaque has now been added to the Arizona State University Dental Anthropology System, an important contribution as maxillary premolar traits are underrepresented in analyses of dental morphology. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.
Hydrogen production by methanol‐steam reforming using NiMoCu/γ‐alumina trimetallic catalysts
Authors: Yaakob Z. , Kamarudin S. K. , Daud W. R. W. , Yosfiah M. R. , Lim K. L. , Kazemian H.
Published: December 2009

Recent attention has focused on steam reforming (SR) of methanol to produce high‐purity hydrogen for ‘clean’ energy applications. Methanol (as a hydrogen carrier) is a renewable and easily accessible energy source that can be produced from biomass and natural gas; the advantages are its availability, high energy density, relative low cost, and easy storage and transportation. In the hydrogen production processes, catalysts play a very critical role for increasing the hydrogen yield and purity as well as reducing by‐products. In this study, the thermodynamic parameters of the methanol‐SR reaction were evaluated. Several NiMoCu/γ‐alumina trimetallic catalysts with different compositions were prepared by a wet impregnation method. The hydrogen production efficiency of the catalysts was evaluated for the methanol‐SR reaction. Thermodynamic studies of the reaction showed that methanol‐SR was an exothermic and spontaneous reaction for all catalysts investigated. Thermodynamic considerations revealed that a catalyst with a composition of 7 wt% Cu, 0.2 wt% Mo and 0.2 wt% Ni was the most reactive catalyst with an enthalpy of − 663.102 kcal. Experimental results showed that the optimum reaction occurred at 548 K and pressure of 3 bar. At these conditions, the production of undesirable by‐products such as CO and CO2 was negligible. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Kinetics of water and alcohol vapors adsorption on natural zeolite
Authors: Ivanova Emilia P. , Kostova Miryana A. , Koumanova Bogdana K.
Published: December 2009

Alcohols are important high volatility industrial chemicals, and when present in low concentrations require highly selective separation techniques. This paper investigates the kinetics of the adsorption of water, methanol, and butanol vapors on natural clinoptilolite based on experimental data obtained from laboratory‐scale equipment under constant saturated vapor pressure conditions at ambient temperature. In order to determine the corresponding mass transfer and diffusion coefficients of the adsorbed components in the zeolite particles, the kinetic curves have been investigated using two simple models—the linear driving force model (LDFM) as well as the particle diffusion model. The equilibrium and the kinetic parameters can also be determined from the experimental values of the statistical moments of the kinetic curves. Two main results have been obtained from this study. At the experimental conditions, the overall rates of adsorption of both methanol and water vapors are nearly equal, and they are of the same order of magnitude to the macro‐(meso)‐pore and intracrystalline diffusion rates predicted for the biporous clinoptilolite structure. In contrast, the diffusion of butanol vapors is much slower in the zeolite particles and particle crystals, where the intracrystalline mass transfer resistance plays a dominant role, even for the largest particles studied. The simple LDFM predictions exhibit very good correlation to the experimental data for all adsorptive components and particle sizes, despite the biporous zeolite structure. This model can be used to provide an acceptable and quick interpretation of adsorption rate curves, even at nonlinear equilibrium conditions. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Tailoring the swelling and glass‐transition temperature of acrylonitrile/hydroxyethyl acrylate copolymers
Authors: Aran Bengi , Sankır Mehmet , Vargün Elif , Sankır Nurdan D. , Usanmaz Ali
Published: December 2009

Novel polyacrylonitrile (PAN)‐co‐poly(hydroxyethyl acrylate) (PHEA) copolymers at three different compositions (8, 12, and 16 mol % PHEA) and their homopolymers were synthesized systematically by emulsion polymerization. Their chemical structures and compositions were elucidated by Fourier transform infrared, 1H‐NMR, and 13C‐NMR spectroscopy. Intrinsic viscosity measurements revealed that the molecular weights of the copolymers were quite enough to form ductile films. The influence of the molar fraction of hydroxyethyl acrylate on the glass‐transition temperature (Tg) and mechanical properties was demonstrated by differential scanning calorimetry and tensile test results, respectively. Additionally, thermogravimetric analysis of copolymers was performed to investigate the degradation mechanism. The swelling behaviors and densities of the free‐standing copolymer films were also evaluated. This study showed that one can tailor the hydrogel properties, mechanical properties, and Tg's of copolymers by changing the monomer feed ratios. On the basis of our findings, PAN‐co‐PHEA copolymer films could be useful for various biomaterial applications requiring good mechanical properties, such as ophthalmic and tissue engineering and also drug and hormone delivery. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Crosslinked methyl methacrylate/ethylene glycol dimethacrylate polymer compounds with a macroazoinitiator
Authors: Naghash Hamid Javaherian , Massah Ahmad Reza , Kalbasi Roozbeh Javad , Arman Masoud
Published: December 2009

A silane‐containing diamine, bis(p‐aminophenoxy) diphenylsilane (BADPS), was prepared by the condensation of p‐aminophenol with dichlorodiphenyl silane in the presence of triethylamine. Then, BADPS was condensed with 4,4‐azobis(4‐cyanopentanoyl chloride) to prepare macroazoinitiators containing silane units (Si–MAIs). A series of poly(methyl methacrylate) gels containing silane were derived by the solution free‐radical crosslinking copolymerization of methyl methacrylate and ethylene glycol dimethacrylate monomers initiated by these macroazoinitiators at a total monomer concentration of 6 mol/L and 80°C. Si–MAIs were characterized with 1H‐NMR and 13C‐NMR spectroscopy, and the structural characteristics of the gels were also examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
On polyethylene chain generation through chemical crosslinking of isotactic polypropylene
Authors: Bouhelal Saïd , Cagiao M. Esperanza , Bartolotta Antonio , Di Marco Gaetano , Garrido Leoncio , Benachour Djafer , Baltá Calleja Francisco J.
Published: December 2009

Crosslinked isotactic polypropylene (iPP) was prepared by reactive blending using dicumyl peroxide and active sulfur. The modified material was characterized by means of several techniques: dynamic mechanical thermal analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance (13C solid state NMR). Analysis of results using the above techniques confirms that, during the crosslinking process, new ethylenic chains are generated at expenses of the initially present iPP. Furthermore, a balance between the amount of missing iPP and the proportion of newly created polyethylene (PE) is observed. The newly formed PE is semicrystalline, having a degree of crystallinity of about 30%. The amorphous component of the generated PE is thought to contribute to the high impact strength of the crosslinked samples when compared to the unmodified iPP. In light of the results obtained by the different techniques, an attempt to describe the emerging structure of the new crosslinked iPP material is proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Aggregation behavior of a water‐soluble terpolymer with vinyl biphenyl characterized by a fluorescent probe
Authors: Zhong Chuanrong , Luo Pingya , Meng Xianghao
Published: December 2009

A terpolymer (PAAP) of acrylamide, sodium 2‐acrylamido‐2‐methylpropane sulfonate, and vinyl biphenyl as a hydrophobic monomer was synthesized to obtain a polymeric oil‐flooding agent with low molecular weight and application in oil reservoirs with medium to low permeability. The intermolecular self‐assembling mechanisms in the PAAP solutions were investigated with a pyrene fluorescence probe as functions of the polymer concentration, surfactant, and temperature. The hydrophobically associating morphologies of PAAP in an unsalted solution were observed with scanning electron microscopy. The results show that the high solution viscosity of PAAP was due to the strong intermolecular hydrophobic associations of the biphenyl groups, and the critical association concentration was 0.05 g/dL for the unsalted and brine PAAP solutions. The nonpolarity and association degree in the hydrophobic microdomains were greatly influenced by the polymer concentration. With the addition of the optimum sodium dodecyl benzene sulfonate concentration, the interpolymer hydrophobic associations were strengthened remarkably via the connection of the surfactant with biphenyl groups from different polymer chains. The number and sizes of the aggregates increased in the range of 20–50°C. These results demonstrate that the thickening effect of the PAAP polymer in the aqueous solution was due to intermolecular associations of the biphenyl groups. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Vapor‐induced swelling of supported methacrylic and siloxane polymer films: Determination of interaction parameters
Authors: Manoli Kyriaki , Goustouridis Dimitris , Raptis Ioannis , Valamontes Evangelos , Sanopoulou Merope
Published: December 2009

White light reflectance spectroscopy is applied to monitor vapor‐induced thickness changes of polymer films, supported on suitable silicon substrates. Assuming unidirectional swelling due to the constraining support, the equilibrium volume swelling of four methacrylic polymers and two siloxane‐based copolymers upon exposure to various activities of water, methanol, ethanol, and ethyl acetate vapor, at 30°C is evaluated. The deduced sorption isotherms were fitted to the Flory‐Huggins equation and interaction parameters, as well as solubility coefficients at infinite solute dilution, were deduced for each binary system. The relative sorption capacity of the different classes of polymers toward the four vapors are in line with the expected solubility interactions between solvent and solute. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Lipases improve the grafting of poly(ethylene terephthalate) fabrics with acrylic acid
Authors: Dadashian F. , Montazer M. , Ferdowsi S.
Published: December 2009

In this study, poly(ethylene terephthalate) (PET) fabrics were modified with two types of commercial lipases, namely, Lipex and Lipolase, and grafted with acrylic acid (AA) to improve their absorption properties. The effects of the enzyme concentration, reaction temperature, time, and pH on the grafting of AA onto PET were investigated. The pretreatment of PET with lipases increased the amount of AA that was introduced to the PET fibers, whereas AA grafting onto the untreated PET fabrics led to lower graft yields. Fourier transform infrared spectroscopy and scanning electron microscopy were used to characterize the AA‐grafted pretreated polyester fabrics. A new band appearing at 1546 cm−1 in the Fourier transform infrared spectrum implied that AA was introduced onto the PET fabrics. The surfaces of the fabric fibers presented in scanning electron microscopy micrographs clearly indicated the formation of a layer of grafted poly (acrylic acid). The results show that the density of surface grafting was improved by the lipase pretreatment. The increase in grafting was higher for Lipex than for Lipolase. The highest graft yield was obtained with 1% Lipex and Lipolase for 30 min at pH values of 7 and 5, respectively. There were no significant changes in the tenacity or weight reduction of the fabrics. The moisture content of the samples increased linearly with increasing graft yield. This was higher for the pretreated fabrics grafted with Lipex. A higher color strength was obtained for grafted PET samples that were pretreated with Lipex when they were dyed in alkaline aqueous solutions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Ethylene–propylene–diene terpolymer/silica compound modification with organosilane [bis(triethoxysilylpropyl)disulfide] and improved processability and mechanical properties
Authors: Kim Kwang‐Jea
Published: December 2009

Bifunctional silane [bis(triethoxysilylpropyl)disulfide (TESPD)] was added to a silica‐containing ethylene–propylene–diene terpolymer mold compound, and its effects with respect to the vulcanization properties, processability, and physical properties were investigated. The addition of TESPD caused reduced heat generation during mixing, low minimum torque, low drop temperature, and low extrusion pressure buildup in the extruder. It also caused a high vulcanization torque, high torque rise, high torque maximum, and high elongational modulus. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Deposition of silicon oxide hard coatings by low‐temperature radio‐frequency plasmas
Authors: Huang Chun , Yu Qingsong
Published: December 2009

In this study, the deposition of silicon oxide (SiOx) hard coatings on polycarbonate (PC) substrates was attempted with low‐temperature radio‐frequency (RF) plasmas from tetramethyldisiloxane (TMDSO) with the addition of oxygen. The coating uniformity and deposition rate were investigated in terms of substrate size, glow uniformity, and RF power input. The hardness of the resulting SiOx plasma coatings was examined by the ASTM pencil hardness test method. The hardness of the resulting SiOx plasma coatings was mainly determined by the TMDSO–O2 ratio in the plasma gas mixture. Ultraviolet–visible transmission spectra showed that these plasma coatings were transparent in the visible light region. Fourier transform infrared–attenuated total reflection analysis results indicated that the resulting SiOx plasma coatings were inorganic in nature. The interfacial adhesion, which is a common problem in the deposition of hard protective coatings on polymeric substrates, was also significantly improved by the deposition of an ultrathin plasma polymer interlayer from TMDSO before the deposition of the SiOx plasma coatings on the PC substrates. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Poly(9‐vinylcarbazole)/silver composite nanotubes and networks formed at the air–water interface
Authors: Wang Chang‐Wei , Xin Guo‐Qing , Lee Yong‐Ill , Hao Jingcheng , Jiang Jianzhuang , Liu Hong‐Guo
Published: December 2009

Silver‐nanoparticle‐doped poly(9‐vinylcarbazole) (PVK) nanocomposites were prepared via the reduction of Ag+ ions and the self‐assembly of PVK on AgNO3 aqueous solution surfaces. The formed composite nanostructures depended strongly on the experimental temperature. Thick round disks of PVK surrounded by discrete Ag nanoparticles and/or with irregular holes formed at room temperature; nanotubes and micronetworks doped with Ag nanoparticles formed at about 30–40°C, and networks formed at higher temperature. Further investigation revealed that the nanotubes were transformed from thin round disks. The length of the PVK/Ag composite nanotubes were longer than 10 μm, and the average size of the embedded Ag nanoparticles was found to be about 3.5 nm. The composite networks were composed of round pores with diameters of several hundred nanometers and fine silver nanoparticles embedded in the thin polymer films that covered the pores. The formation of the nanotubes was a very interesting self‐assembly phenomenon of the polymer at the air–water interface that has not been reported before. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Fabrication and characterization of TiO2/poly(dimethyl siloxane) composite fibers with thermal and mechanical stability
Authors: Kim Young Bum , Cho Donghwan , Park Won Ho
Published: December 2009

The mechanical stability of titania (TiO2) nanofibers was improved by fabricating TiO2/poly(dimethyl siloxane) (PDMS) composite fibers using a combination of hybrid electrospinning and sol‐gel methods, followed by heat treatment at 250°C for 3 h. The compositions (90/10, 80/20, and 70/30, w/w) of the TiO2/PDMS composite fibers were varied by adjusting the flow rate of the PDMS sol with the flow rate of TiO2 sol fixed. There was no significant change in morphology and average diameter of the as‐spun TiO2/PDMS fibers after heat treatment. Both the tensile strength and modulus of the TiO2/PDMS composite fibers increased gradually with increasing PDMS content up to 30 wt %. In addition, from the photo‐degradation reaction of methylene blue, the photocatalytic activity of TiO2/PDMS composite fibers was strongly dependent on the TiO2 content (%) in the composite fibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rigid‐rod polybenzoxazoles containing perylene bisimide: Synthesis, structures and photophysical properties
Authors: Xu Xiao‐Hui , Liu Xiao‐Yun , Zhuang Qi‐Xin , Han Zhe‐Wen
Published: December 2009

A novel perylene bisimide dye bearing carboxylphenylene substituents on the imide N atoms was synthesized and four conjugated copolymers containing different contents of perylene bisimide dye were synthesized via PPA/P2O5 copolymerization method. The structures of the four copolymers were characterized by FTIR, elementary analysis, 1H‐NMR and XRD. The copolymers showed good thermal stabilities but poor solubilities due to the high rigidity of the backbone. The photophysical characteristics of the copolymers were investigated by UV‐Vis and PL spectra in solutions and films. Because of the conformational change of perylene bisimide chromophore, the absorptions of perylene bisimide core in copolymers showed a large blue‐shift (56 nm) compared to that of the perylene monomer. In PL experiments, when exciting the benzoxazole, an obvious fluorescent quenching was observed in all copolymers, which can be attributed to the energy transfer from benzoxazole units to perylene bisimide fragments and fluorescence quenching. With increasing perylene content, the copolymers turned to layered and friable. The XRD test showed that the interchain distances increased slightly with increasing perylene content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Viscosity effects in the photopolymerization of two‐monomer systems
Authors: Marcinkowska Agnieszka , Andrzejewska Ewa
Published: December 2009

Photopolymerization kinetics and viscosity behavior of five different two‐monomer systems forming hydrogen bonds and composed of mixtures of a high viscosity monomer (HVM) and a low viscosity monomer (LVM) at various molar ratios were investigated at six polymerization temperatures. The monomers used were mono‐ or dimethacrylates. Detailed viscosity measurements of the monomer mixtures showed significant negative deviations from the theoretical values (characterized by excess logarithm viscosities) indicating that interactions between the molecules of the same type (in individual monomers) are stronger than those between two molecules of different types (HVM and LVM). The photopolymerization kinetics were analyzed from the point of view of the appearance, viscosity and temperature behavior of the most reactive composition (MRC), the one showing the highest value of the maximum polymerization rate within a range of the HVM: LVM ratios. It was found that MRC appearance is determined mainly by the initial viscosity of the two‐monomer system, whereas the functionality of the monomers (and network formation) is much less important (MRC is observed even in linear systems). The initial viscosity of all the monomer mixtures showing MRC lay in the range of 0.06–2 Pa s, which is narrow compared to the range of viscosities of the monomers (approximately 10−3–103 Pa s). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of regenerated Antheraea yamamai silk fibroin film and controlled‐molecular conformation changes by aqueous ethanol treatment
Authors: Zheng Zhonghou , Wei Yanqiong , Yan Shuqin , Li Mingzhong
Published: December 2009

The methods of dissolving Antheraea yamamai (A. yamamai) silk fibroin fibers and preparing the regenerated silk fibroin were studied. The molecular conformations of A. yamamai silk fibroin film treated by different concentration ethanol solution were investigated by XRD, FTIR, and Raman spectra. The results indicated that A. yamamai silk fibroin fibers could be completely dissolved in dense lithium thiocyanate solution at about 35°C for 1 h. The initial regenerated film consisted of α‐helix and random coil components. The aqueous ethanol treatment of the film resulted in significant increase in β‐sheet component and improvement of water resistance of the film. This effect was strongly dependent on ethanol concentration, and 60–80% (w/w) ethanol was most effective. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Imidazolium salts as liquid coupling agents for the preparation of polypropylene‐silica composites
Authors: Donato Ricardo K. , Benvegnú Moisés A. , Furlan Luciano G. , Mauler Raquel S. , Schrekker Henri S.
Published: December 2009

This article describes the application of ionic liquid 1‐decyl‐3‐methylimidazolium tetrafluoroborate in the preparation of polypropylene‐silica composites. The sol‐gel technology was used to prepare xerogel silica‐ionic liquid hybrid S1, which was obtained as a free flowing powder of aggregated spherical particles. Ionic liquid free silica S2 was obtained by extraction and calcination of S1. Melt blending of isotactic polypropylene with S1 and S2 afforded the composites C1 (with ionic liquid) and C2 (without ionic liquid), respectively. The presence of ionic liquid on the S1 silica surface promoted significantly improved silica dispersion in the polymer matrix and prevented compression of the silica particles. Furthermore, the crystallization temperature of composite C1 was significantly higher, which indicated that silica‐ionic liquid filler S1 acted as nucleating agent. The resistance to thermal decomposition of both composites was increased, but this was higher in the presence of ionic liquid. These results show that liquid salts can function as coupling agents and compatibalizers for the preparation of polymeric composites with differentiated properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rapid and efficient removal of heavy metal ions from aqueous media using cysteine‐modified polymer nanowires
Authors: Tolani Sagar , Mugweru Amos , Craig Michael , Wanekaya Adam K.
Published: December 2009

We report the development of a novel, simple, and highly effective polymeric material with nanoscale dimensions for use in removal of heavy metal ions from aqueous media. The nanomaterial was ∼ 200 nm in diameter and several microns long and was fabricated in the form of nanowires via template‐directed electrochemical polymerization. The nanowires were covalently modified by cysteine, a nonessential amino acid with very high binding constants for selected toxic heavy metal ions, such as, As3+, Cd2+, Pb2+, and Cu2+. We demonstrated rapid and efficient removal of As3+, Cd2+, Pb2+, and Cu2+ ions from natural water samples. The arsenic removal capacity was found to be ∼ 160 mg As3+ per gram of the material, a substantially greater removal capacity than other materials reported to date. The removal capacity of other heavy metals ions was also rapid and effective, their concentrations becoming undetectable in a matter of minutes after treatment with the nanowires. These nanowires have demonstrated potential that could lead to a low cost, novel, and highly effective technique for use in treatment of drinking water and for other environmental remediation purposes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of polymer–nanoclay conductive nanocomposites
Authors: Ahmad Irfan , Hussain Manwar , Seo Keum‐Suk , Choa Yong‐Ho
Published: December 2009

Polymer–clay nanocomposites based on poly(3,4‐ethylenedioxythiophene)/polystyrene sulfonate (PEDOT) : PSS and nanoclay montmorillonite were synthesized and characterized. The doping of PEDOT with polystyrene sulfonate made it water dispersible (PEDOT–PSS). Sodium dodecyl benzene sulfonate (SDBS) and ionic liquid were used to increase the interlayer spacing and the conductivity of the nanocomposites, respectively. The nanocomposite was characterized by various techniques, such as X‐ray diffraction (XRD), TEM, surface resistivity, and thermogravimetric measurement analysis. Interlayer spacing increased as a result of the addition of SDBS, and this was confirmed by the 2θ shift observed via XRD analysis. The surface morphology of the conductive coated clay was examined by TEM analysis. Good electrical surface conductivity, interlayer spacing, and polymer coating were observed for the material prepared using the surfactant and conductive ionic liquid. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
In‐process ultrasonic measurements of orientation and disorientation relaxation of high‐density polyethylene/polyamide‐6 composites with compatibilizer
Authors: Lin Congmei , Sun Huimin , Wang Shan , Huang Jian , Li Jiang , Guo Shaoyun
Published: December 2009

The relaxation processes of orientation and disorientation of melts of high‐density polyethylene (HDPE) and polyamide‐6 (PA6) blends compatibilized with a compatibilizer precursor (CP) of HDPE‐grafted maleic anhydride (HDPE‐g‐MAH) were investigated in a restricted channel using real‐time ultrasonic technique. The experimental results showed that the evolution of ultrasonic velocity of HDPE/PA6 blends during the orientation or disorientation processes could be described by the exponential equation from which the maximum orientation degree and relaxation time could be obtained. Subsequently, the effects of CP on the relaxation processes of orientation and disorientation were studied. In addition, the relations of the CP content and the morphology and viscosity were investigated by scanning electron microscope analysis and rheological tests. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Emulsion polymerization of isoprene. Estimation of the branching exponent with the help of a mathematical model
Authors: Minari Roque J. , Rodriguez Virginia I. , Estenoz Diana A. , Vega Jorge R. , Meira Gregorio R. , Gugliotta Luis M.
Published: December 2009

This work investigates a batch and unseeded emulsion polymerization of isoprene at 10°C with n‐dodecylmercaptan as chain transfer agent (CTA). The obtained polyisoprene (PI) was analyzed by size exclusion chromatography (SEC) with on‐line viscometry. A global polymerization model was adjusted to the measurements of conversion, average particle size, and average molecular weights. The CTA concentration strongly affects the average molecular weights but has a negligible effect on conversion, average particle diameter, and average branching. Due to the combined effects of chain transfers to the polymer and to the CTA, the final molar mass distributions exhibited dispersity indexes higher than 10. The polymerization model predictions on the average degree of branching was combined with an ideal SEC model for adjusting the branching exponent of PI in tetrahydrofuran at 25°C that resulted ε = 2.5. A sensitivity analysis showed that +20% errors in $\overline{M}$w induced variations in ε lower than −10%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Sustained release of tetracycline from polymeric periodontal inserts prepared by extrusion
Authors: Obaidat Aiman A. , Hammad Mohammad M.
Published: December 2009

The specific aim of this study was to prepare polymeric inserts containing tetracycline that are intended for intraperiodontal pocket application. The inserts were prepared by a simple extrusion method and based on mixtures of polyvinyl alcohol, glyceryl behenate, xanthan gum, carrageenan, hydroxypropyl methylcellulose, and hyaluronic acid in addition to tetracycline HCL. The inserts were characterized regarding average weight, diameter, water content, and average tetracycline content. Zero‐order release kinetics of tetracycline were observed in case of three of the four batches of the prepared inserts with release profiles that were essentially similar. The release of the drug was incomplete in all cases. This was due, as shown by the equilibrium dialysis tests, to tetracycline binding by the polymers. However, the inserts performed more than 7 days drug sustained release which indicates promising results for local delivery of tetracycline for treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010