bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chain internal/chain end latent crosslinking in thermoset polymer systems
Authors: Matloka Piotr P. , Kean Zachary , Wagener Kenneth B. 
Published: March 2010

AbstractThe combination of both chain‐internal/chain‐end latent crosslinking in a single thermoset polymer system is the subject of this study. A series of linear carbosiloxane/hydrocarbon homopolymers were synthesized by metathesis polycondensation, polymers which serve as the soft phase in the target chain‐internal/chain‐end latent crosslinked materials. These carbosiloxane/hydrocarbon “soft phase” homopolymers exhibited excellent performance parameters, displaying purely amorphous character with glass transition temperatures ranging between −104 °C and −90 °C depending on the run length of siloxane or hydrocarbon methylene units within the carbosiloxane/hydrocarbon monomer. These soft phase monomers were then copolymerized with latent chain‐internal crosslinking carbosilane monomers in the presence of latent chain‐end crosslinking molecules thereby generating a new class linear copolymers capable of being moisture cured to produce a new class of silicon‐based thermoset systems. Mechanical properties of these thermosets, show breaking strengths up to 0.5 MPa and elongations up to 100%. Both elastic and plastic behavior can be observed in such systems, depending upon the molar ratio of carbosiloxane/hydrocarbon co‐monomer and the carbosilane co‐monomer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1866–1877, 2010
End‐linked amphiphilic polymer conetworks: Synthesis by sequential atom transfer radical polymerization and swelling characterization
Authors: Rikkou Maria D. , Kolokasi Maria , Matyjaszewski Krzysztof , Patrickios Costas S. 
Published: March 2010

AbstractConetworks based on end‐linked homopolymers and amphiphilic gradient copolymers were synthesized by the atom transfer radical polymerization (ATRP) of 2‐(dimethylamino)ethyl methacrylate (DMAEMA, hydrophilic monomer), methyl methacrylate (MMA, hydrophobic monomer), and ethylene glycol dimethacrylate (EGDMA, hydrophobic cross‐linker). Sequential, rather than step‐wise polymerizations, were performed to enhance the livingness of the polymerization, particularly for the end‐linking step, and to ultimately obtain conetworks based on gradient rather than pure block copolymers. Amphiphilic conetworks based on end‐linked MMA‐DMAEMA‐MMA gradient copolymers of different compositions were successfully synthesized as confirmed by the narrow molecular weight distributions of the linear precursors, the rigidity of the amphiphilic conetwork products and the low sol‐fraction extracted from the conetworks. Similarly successful was the ATRP synthesis of an end‐linked conetwork based on a DMAEMA‐MMA statistical copolymer and of a randomly cross‐linked conetwork that resulted from the simultaneous terpolymerization of DMAEMA, MMA and EGDMA. An amphiphilic conetwork based on an end‐linked DMAEMA‐MMA‐DMAEMA gradient copolymer presented a less rigid, mucous‐like, texture. The degrees of swelling (DS) in tetrahydrofuran of all the conetworks were higher than those measured in pure water, whereas the aqueous DS values increased by lowering the pH and increasing the DMAEMA content of the conetworks. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1878–1886, 2010
Facile one‐pot synthesis and thermal cyclopolymerization of aryl bistrifluorovinyl ether monomers bearing reactive pendant groups
Authors: Zhu Kaizheng , Iacono Scott T. , Budy Stephen M. , Jin Jianyong , Smith Dennis W. 
Published: March 2010

AbstractA diverse pool of aryl bistrifluorovinyl ether (BTFVE) compounds with reactive pendant groups were prepared in a facile, high yielding three step “one‐pot” synthesis from commercial 4‐bromo(trifluorovinyloxy)benzene. Monomers were confirmed from ATR–FTIR, 1H, 13C, and 19F NMR, and HRMS analysis. Aryl BTFVE compounds were thermally polymerized to afford perfluorocyclobutyl (PFCB) aryl ether polymers with high number–average molecular weight (Mn) for homopolymers (17,050–27,090) and copolymers with 4,4′‐bis(trifluorovinyloxy)biphenyl monomers (27,860–56,500). The PFCB aryl ether homo‐ and copolymers collectively possess high thermal stability (>299 °C in N2) and are readily solution processable producing optically transparent films. The thermal polymerization was achieved and reactive moieties remained intact, aside from those functionalized with acrylates. In the case with acrylate functionalized polymers, orthogonal polymerization was achieved by first photopolymerizing the acrylates followed by thermal curing of the aryl trifluorovinyl ether endgroups. Preliminary results in this study produced the successful preparation of photodefinable PFCB aryl ether material. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1887–1893, 2010
Organic soluble deoxyribonucleic acid (DNA) bearing carbazole moieties and its blend with phosphorescent Ir(III) complexes
Authors: Cho Min Ju , Lee U Ra , Kim Youn Sun , Shin Jicheol , Kim Young Min , Park Young Wook , Ju Byeong‐Kwon , Jin Jung‐Il , Choi Dong Hoon 
Published: March 2010

AbstractA functionalized deoxyribonucleic acid (Cz‐DNA) was prepared with carbazolyl ammonium lipid as a triplet host material for phosphorescent material system. It is soluble in organic solvents, which facilitates the sample preparation for the absorption and luminescent properties in solid states. A highly soluble iridium complex, Ir(Cz‐ppy)3 with carbazolyl‐substituted 2‐phenylpyridine ligands was employed for studying the phosphorescence in Cz‐DNA. There is a good overlap between the photoluminescence spectrum of Cz‐DNA and the metal‐to‐ligand charge transfer (MLCT) absorption bands of the iridium complex. This overlap enables efficient energy transfer from the excited state in the host to the MLCT band of Ir(Cz‐ppy)3. In addition, photoluminescence quantum yield of Cz‐DNA was found to be relatively larger than the copolymer (PCzSt) with vinylcarbazole and styrene. Thus, Cz‐DNA was employed as a triplet host material for fabricating multilayered electrophosphorescence devices via modification of its property by doping 5,4‐tert‐butylhexyl‐1,3,4‐oxadiazole (PBD). After doping 30 wt % PBD and 10 wt % Ir(Cz‐ppy)3 into Cz‐DNA, we achieved much improvement in electron injection/transport from an adjacent carrier transport layer, resulting in much improved device performances. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1913–1918, 2010
Synthesis and physicochemical characterization of biodegradable and pH‐responsive hydrogels based on polyphosphoester for protein delivery
Authors: He Jinlin , Ni Peihong , Wang Sai , Shao Haiyan , Zhang Mingzu , Zhu Xiulin 
Published: March 2010

AbstractIn this work, a series of biodegradable and pH‐responsive hydrogels based on polyphosphoester and poly(acrylic acid) are presented. A novel biodegradable macrocrosslinker α‐methacryloyloxyethyl ω‐acryloyl poly(ethyl ethylene phosphate) (HEMA‐PEOP‐Ac) was synthesized by first ring‐opening polymerization of the cyclic monomer 2‐ethoxy‐2‐oxo‐1,3,2‐dioxaphospholane using HEMA as the initiator and Sn(Oct)2 as catalyst, and subsequent conversion of hydroxyl into vinyl group. The hydrogels were then fabricated by the copolymerization of the macromonomer with acrylic acid, and their swelling/deswelling and degradation behaviors were investigated. The results demonstrated that the crosslinking density and pH values of media strongly influenced both the swelling ratio and the degradation rate of the hydrogels. The rheological properties of these hydrogels were also studied from which the storage modulus (G′) showed clear dependence on the crosslinking density. MTT and “live/dead” assay showed that these hydrogels were compatible to fibroblast cells, not exhibiting apparent cytotoxicity even at high concentrations. Moreover, in vitro bovine serum albumin release from these hydrogels was also investigated, and it could be found that the release profiles showed a burst effect followed by a continuous release phase, and the release rate was inversely proportional to the crosslinking density of hydrogels. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1919–1930, 2010
Tough interconnected polymerized medium and high internal phase emulsions reinforced by silica particles
Authors: Wu Ranting , Menner Angelika , Bismarck Alexander 
Published: March 2010

AbstractEmulsion templating using high internal phase emulsions is an effective route to prepare low density and high porosity macroporous polymers known as polymerized high internal phase emulsions (polyHIPEs). Conventional polyHIPEs, synthesized from surfactant stabilized w/o emulsions have low permeabilities and poor mechanical properties. We present interconnected open macroporous low density nanocomposites produced by polymerizing the continuous phase of emulsion templates, which contained styrene, polyethyleneglycoldimethacrylate, and silylated silica particles. Polyethyleneglycoldimethacrylate and the silylated silica particles acted as crosslinker. The functionalized silica particles were incorporated into the polymer, which resulted in a significant improvement of the mechanical properties of the polyHIPEs without affecting the interconnected and permeable pore structures. The polyHIPEs contained up to 60 wt % silylated silica particles. Young's modulus of the reinforced macroporous polymers increased up to 600% compared with nonreinforced macroporous polymers. The mechanical performance was further increased by increasing the foam density of the macroporous nanocomposites from around 200 to 370 g/cm3 by raising the organic phase volume of the emulsion templates from 20 to 40 vol %. The macroporous polymers synthesized from less concentrated emulsions also possessed interconnected open porous although less permeable structures. The polyHIPE nanocomposites have a permeability of about 200 mD, whereas the polyMIPE nanocomposites still have permeabilities of around 50 mD. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1979–1989, 2010
Air‐tolerantly surface‐initiated AGET ATRP mediated by iron catalyst from silica nanoparticles
Authors: Li Qiang , Zhang Lifen , Zhang Zhengbiao , Zhou Nianchen , Cheng Zhenping , Zhu Xiulin 
Published: March 2010

AbstractWell‐defined polymer‐nanoparticle hybrids were prepared by a newly reported method: atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) mediated by iron catalyst. The kinetics of the surface‐initiated AGET ATRP of methyl methacrylate from the silica nanoparticles, which was mediated by FeCl3/triphenylphosphine as a catalyst complex, ascorbic acid as a reducing agent, N,N‐dimethylformamide as the solvent in the presence of a “sacrificial” (free) initiator, was studied. Both the free and grafted polymers were grown in a control manner. The chemical composition of the nanocomposites was characterized by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and 1H nuclear magnetic resonance spectroscopy. Thermogravimetric analysis was used to estimate the content of the grafted organic compound, and transmission electron micrographs was used to observe the core‐shell structure of the hybrid nanoparticles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2006–2015, 2010
Synthesis of polystyrene‐based random copolymers with balanced number of basic or acidic functional groups
Authors: Dimitrov Ivaylo , Jankova Katja , Hvilsted Søren 
Published: March 2010

AbstractPairs of polystyrene‐based random copolymers with balanced number of pendant basic or acidic groups were synthesized utilizing the template strategy. The same poly[(4‐hydroxystyrene)‐ran‐styrene] was used as a template backbone for modification. Two different synthetic approaches for the functionalization were applied. The first one involved direct functionalization of the template backbone through alkylation of the phenolic groups with suitable reagents. The second modification approach was based on “click” chemistry, where the introduction of alkyne groups onto the template backbone was followed by copper‐catalyzed 1,3 cycloaddition of aliphatic sulfonate‐ or amine‐contaning azides. Both synthetic approaches proved to be highly efficient as evidenced by 1H‐NMR analyses. The thermal properties were evaluated by differential scanning calorimetry and thermal gravimetric analyses and were influenced by the type of functionality and the modification method. The ether‐linked functional colopymers were thermally more stable than their “clicked” analogues. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2044–2052, 2010
Crystal growth rates and master curves of poly(ethylene succinate) and its copolyesters using a nonisothermal method
Authors: Tsai Chia‐Jung , Chen Ming , Lu Hsin‐Ying , Chang Wei‐Che , Chen Chi He 
Published: March 2010

AbstractThe spherulitic growth of poly(ethylene succinate) (PES) and two PES‐rich copolyesters at constant cooling rate was monitored and recorded using a system of polarized light microscope. Individual experiment of these polyesters lasted 40, 60, and 120 min, respectively. A continuous curve of isothermal growth rates between the melting and glass transition temperatures can be obtained after curve fitting procedures. These curves fit very well with those data points determined in the isothermal experiments, which are time consuming. The continuous data of PES was analyzed with the Hoffman (Lauritzen equation. A transition of regime II → III was found at 70.7 °C, which is very close to the literature values. The maximum growth rate was formulated in the Arrhenius and WLF expressions for the molecular transport term. A master curve of crystal growth rate for PES was constructed based on the continuous data of PES. When the reduced growth rates after normalization were plotted against the reduced temperatures, a universal master curve was observed for PES and two PES‐rich copolyesters. This nonisothermal method provides an efficient and reliable way for studying the crystallization kinetics of polymer and for constructing a universal master curve of crystal growth rate of PES. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 932–939, 2010
Biological Evaluation of DNA Damage in Bacteriophages Inactivated by Atmospheric Pressure Cold Plasma
Authors: Yasuda Hachiro , Miura Takuya , Kurita Hirofumi , Takashima Kazunori , Mizuno Akira 
Published: March 2010

AbstractInactivation mechanisms of plasma treated microorganisms are still major subjects. We have developed a biological assay which evaluates in vivo DNA damage of the viruses treated with non‐thermal atmospheric pressure plasma in air. Different doses of the plasma were applied to wet state of λ phage particles under neutral pH and near the room temperature. From each sample of treated λ phages, DNA was purified and subjected to in vitro DNA packaging reactions. Survival curves of the re‐packaged phages showed an extremely large D value (D = 25 s) compared to the previous D value (D = 3 s) obtained from the survival curves of the treated phages. The results indicate the evidence that DNA damage hardly contributed to the inactivation.
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Crystal structure of the C‐terminal domain of the Salmonella type III secretion system export apparatus protein InvA
Authors: Worrall Liam J. , Vuckovic Marija , Strynadka Natalie C. J. 
Published: March 2010

AbstractInvA is a prominent inner‐membrane component of the Salmonella type III secretion system (T3SS) apparatus, which is responsible for regulating virulence protein export in pathogenic bacteria. InvA is made up of an N‐terminal integral membrane domain and a C‐terminal cytoplasmic domain that is proposed to form part of a docking platform for the soluble export apparatus proteins notably the T3SS ATPase InvC. Here, we report the novel crystal structure of the C‐terminal domain of Salmonella InvA which shows a compact structure composed of four subdomains. The overall structure is unique although the first and second subdomains exhibit structural similarity to the peripheral stalk of the A/V‐type ATPase and a ring building motif found in other T3SS proteins respectively.
Finiteness in SU(3)3 models
Authors: Heinemeyer S. , Ma E. , Mondragon M. , Zoupanos G. 
Published: March 2010

AbstractWe consider N = 1 supersymmetric gauge theories based on the group SU(N)1 × SU(N)2 × … × SU(N)k with matter content (N, N*, 1, …, 1) + (1, N, N*, …, 1) + … + (N*, 1, 1, …, N), which are finite if and only if there are exactly three generations. We study in particular two models with SU(3)3 as gauge group, an all‐loop and a two‐loop finite model, and we examine their predictions concerning the third generation quark masses.
Monitoring for imidacloprid resistance in the tobacco‐adapted form of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), in the eastern United States
Authors: Srigiriraju Lakshmipathi , Semtner Paul J , Bloomquist Jeffrey R 
Published: March 2010

AbstractBACKGROUND: Imidacloprid is the primary insecticide for controlling the tobacco‐adapted form of the green peach aphid (TGPA), Myzus persicae (Sulzer), a major pest of tobacco worldwide. This study used leaf‐dip bioassays to assess TGPA resistance to imidacloprid in the eastern United States from 2004 through 2007.RESULTS: When combined over the 4 year study, 18, 14 and 3% of the TGPA had imidacloprid resistance ratios (RRs) of 10–20‐fold, 20–30‐fold and 30–90‐fold, respectively, compared with the most susceptible colony tested. This indicates that some colonies have developed moderate levels of resistance to imidacloprid. A colony collected near Clayton, North Carolina, had the highest RR of 91 (LC50 value = 31 mg L−1). This resistance declined for six tests over a 3 year period in the laboratory culture from >130‐fold RR (LC50 = 48 mg L−1) to 40‐fold RR (LC50 = 15 mg L−1). Over the same period, the most susceptible colony and a standard colony not exposed to imidacloprid for over 7 years had consistently low LC50 values.CONCLUSION: Moderate levels of resistance to imidacloprid are noticed among TGPA colonies from the eastern United States. The variation in resistance indicates that the factors responsible are present in the populations at low frequencies and are just not enough to cause field failures yet. Copyright © 2010 Society of Chemical Industry
Field performance of Lynfield and McPhail traps for monitoring male and female sterile Bactrocera tryoni (Froggatt) and wild Dacus newmani (Perkins)
Authors: Dominiak Bernie C , Nicol Helen I 
Published: March 2010

AbstractBACKGROUND: McPhail traps, baited with protein food lure, are used worldwide for surveillance of many species of fruit flies. Queensland fruit fly (Qfly) Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) is a native Australian fruit fly and normally monitored using Lynfield traps baited with cuelure. On some occasions, McPhail traps with wet food lures are deployed to detect female flies or to find the incursion epicentre. This paper reviews field results on the merits of Lynfield and McPhail traps for detection of male and female Qfly.RESULTS: Following release of equal numbers of sterile males and females, Lynfield traps baited with cuelure captured more Qfly males than protein autolysate or orange concentrate in McPhail traps. Significantly more male than female Qfly were captured in McPhail traps baited with protein autolysate or orange. There was no significant difference between orange concentrate lure and protein autolysate lure in attracting either males or females. Another Australian native fruit fly, Dacus newmani (Perkins), was attracted to cuelure in Lynfield traps but not to either lure in McPhail traps.CONCLUSIONS: The data obtained run counter to the reputation of McPhail traps baited with protein autolysate or orange concentrate as a specialist lure/trap combination for female Qfly. Copyright © 2010 Society of Chemical Industry
Bacopa monniera (L.) wettst inhibits type ii collagen‐induced arthritis in rats
Authors: Viji V. , Kavitha S. K. , Helen A. 
Published: March 2010

AbstractBacopa monniera (L.) Wettst is an Ayurvedic herb with antirheumatic potential. This study investigated the therapeutic efficacy of Bacopa monniera in treating rheumatoid arthritis using a type II collagen‐induced arthritis rat model. Arthritis was induced in male Wistar rats by immunization with bovine type II collagen in complete Freund's adjuvant. Bacopa monniera extract (BME) was administered after the development of arthritis from day 14 onwards. The total duration of experiment was 60 days. Paw swelling, arthritic index, inflammatory mediators such as cyclooxygenase, lipoxygenase, myeloperoxidase and serum anti‐collagen IgG and IgM levels were analysed in control and experimental rats. Arthritic induction significantly increased paw edema and other classical signs of arthritis coupled to upregulation of inflammatory mediators such as cyclooxygenase, lipoxygenase, neutrophil infiltration and increased anti‐collagen IgM and IgG levels in serum. BME significantly inhibited the footpad swelling and arthritic symptoms. BME was effective in inhibiting cyclooxygenase and lipoxygenase activities in arthritic rats. Decreased neutrophil infiltration was evident from decreased myeloperoxidase activity and histopathological data where an improvement in joint architecture was also observed. Serum anti‐collagen IgM and IgG levels were consistently decreased. Thus the study demonstrates the potential antiarthritic effect of Bacopa monniera for treating arthritis which might confer its antirheumatic activity. Copyright © 2010 John Wiley & Sons, Ltd.
Bioactivity of a flavanol‐rich lychee fruit extract in adipocytes and its effects on oxidant defense and indices of metabolic syndrome in animal models
Authors: Kalgaonkar Swati , Nishioka Hiroshi , Gross Heidrun B. , Fujii Hajime , Keen Carl L. , Hackman Robert M. 
Published: March 2010

AbstractMany polyphenolic compounds are poorly digested, and have low bioavailability due to their long chain lengths and chemical composition. A processed, flavanol‐rich lychee fruit extract (FRLFE) that is higher in flavanol monomers, dimer and trimers than its unprocessed counterpart, was tested in a variety of models. First, mature visceral adipocytes were treated with 0, 3, 10 or 30 μg/mL FRLFE (day 6–8). Compared with the controls, the treated cells had lower triglyceride concentrations, less lipid accumulation and a smaller lipid droplet size. Adiponectin release was significantly greater in cells receiving 3 or 10 μg/mL FRLFE than in the controls. Second, rats given a single dose of 50 or 100 mg/kg FRLFE had significant increases in plasma (‐)‐epicatechin, 3′‐O‐methyl‐(‐)‐epicatechin, and (+)‐catechin levels, peak values were at approximately 2 h and appreciable concentrations were still detected at 6 h. Rats supplemented daily for 1 week with 50 or 100 mg/kg FRLFE had significantly elevated metabolite concentrations. In response to an oxidative stress, erythrocyte membrane integrity was significantly improved in the 100 mg/kg FRLFE group. Third, 7‐month‐old mice fed a 200 mg/kg FRLFE diet for 10 months showed a significant decrease in glucose, triglyceride and lipid peroxide levels compared with mice fed a control diet. Collectively, these results support the concept that the flavanols present in FRLFE are well absorbed and bioactive. Copyright © 2010 John Wiley & Sons, Ltd.