bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalization of lignin: Synthesis of lignophenol‐graft‐poly(2‐ethyl‐2‐oxazoline) and its application to polymer blends with commodity polymers
Authors: Nemoto Tadamasa , Konishi Gen‐ichi , Tojo Yusuke , An Youn Chul , Funaoka Masamitsu 
Published: September 2011

AbstractLignophenol (LP)‐graft‐poly(2‐ethyl‐2‐oxazoline) (POZO) was prepared to reuse lignin, an industrial waste material, and to produce novel LP‐based polymer blends with poly(vinyl chloride) (PVC), poly(bisphenol A carbonate) (PC), polyvinylpyrrolidone (PVP), and polystyrene (PSt) as commodity polymers. The resulting graft polymer was soluble in various types of organic solvents such as chloroform, THF, acetone, and methanol, unlike LP. The miscibility of LP‐graft‐POZO with commodity polymers was measured by differential scanning calorimetry (DSC) to determine the glass transition temperatures (Tg). In the cases of the blends of LP‐graft‐POZO with PVC, PC, and PVP, the Tg values decreased during the second scan. Moreover, in the cases of the blends with PVC and PVP, the Tg values were not detected during the third scan. Therefore, it was inferred that LP‐graft‐POZO was miscible with PVC, PC, and PVP while forming single phases; in particular, the blends of LP‐graft‐POZO with PVC and PVP exhibited a secondary miscibility because the Tg values were not detected. Furthermore, the blend of LP‐graft‐POZO with PC exhibited better thermostability than LP and LP‐graft‐POZO. These results indicated that LP blended with POZO could be used as a polymer additive and as an adhesive to combine different polymers, organic–inorganic polymers, etc. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of KOH concentration in the gel polymer electrolyte for direct borohydride fuel cell
Authors: Ng Pao Ling , Jamaludin Aliyah , Alias Yatimah , Basirun Wan Jefrey , Ahmad Zainal Arifin , Mohamad Ahmad Azmin 
Published: September 2011

AbstractThe performance of a direct borohydride fuel cell (DBFC) based on a polyacrylamide (PAAm) gel polymer electrolyte system is investigated at different electrolyte concentrations. The DBFC, constructed using 2M sodium borohydride (NaBH4) as the fuel and potassium hydroxide (KOH) solution gelled with PAAm as the electrolytes yield the highest electrical conductivity of 2.73 × 10−1 S cm−1 at 6M KOH. The optimized composition, PAAm + 2M NaBH4 + 6M KOH, and the selected composition, PAAm + 2M NaBH4 + 3M KOH are then used in preparing the cells. Open‐circuit voltages for fuel cells is about 0.85–0.92 V, and the discharge characteristic produce discharge capacities of about 257.12–273.12 mAh cm−2 for cells with PAAm‐6M KOH. Current‐voltage and current density‐power density plots and internal resistance for both cells are almost the same. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrical and optical properties of polymer‐Au nanocomposite films synthesized by magnetron cosputtering
Authors: Liu Fanjung , Shang Songmin , Duan Yajun , Li Liang 
Published: September 2011

AbstractPolymer‐Au nanocomposite films were prepared by co‐sputtering from two independent magnetron sources. By sputtering from gold and polytetrafluoroethylene (PTFE) magnetrons, we prepared homogenous composite films using a rotatable sample holder. The microstructure of the nanocomposites was studied by transmission electron microscopy (TEM). The resistivity drops from 107 to 10−3 Ohm cm over a narrow range of metal content. The thin composite films show a strong optical absorption in the visible region due to surface plasmon resonances. The optical absorption has a strong dependence on the metal content, showing a red shift of the absorption peak from 550 nm to more than 700 nm with increasing gold content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on mixed‐mode fracture characterization in functionally graded materials
Authors: Liu D. L. , Yao X. F. , Ma Y. J. , Xu W. 
Published: September 2011

AbstractThe fracture characterizations on mixed‐mode crack of functionally graded materials (FGMs) are investigated using digital speckle correlation method (DSCM). The stress intensity factors at mixed‐mode crack tip are obtained from digital speckle displacements fields. In combination with finite elements simulation results, the influences of gradient coefficients on fracture behavior of mixed‐mode cracks are analyzed. All the results show that the influence of gradient coefficients on fracture modes is not noticeable, and the stress intensity factor at the crack tip in graded materials are clearly influenced by the gradient coefficients, i.e., the stress intensity factors decrease with the increasing of gradient coefficients. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Flame‐retardant polycarbonate/acrylonitrile‐butadiene‐styrene based on red phosphorus encapsulated by polysiloxane: Flame retardance, thermal stability, and water resistance
Authors: Jian Rong‐Kun , Chen Li , Hu Zhi , Wang Yu‐Zhong 
Published: September 2011

AbstractRed phosphorus encapsulated by polysiloxane (MRP) was prepared, and the chemical structure and morphology of MRP were characterized by FTIR and TEM, respectively. A series of flame retardant polycarbonate/acrylonitrile‐butadiene‐styrene containing MRP (PC/ABS/MRP) were prepared via melt‐blending. The flame retardance of PC/ABS/MRP was investigated by limiting oxygen index (LOI) and UL‐94 test. It was shown that the LOI value was increased to 27.7 and UL‐94 achieved a V‐0 rating at a 15 wt % loading of MRP. Cone calorimetric results showed that the peak of heat release rate (PHRR) of PC/ABS/15% MRP decreased from 452.7 to 198.0 kW/m2, and the total heat release decreased from 92.9 to 60.7 MJ/m2 compared with virgin PC/ABS. Thermal stability analysis showed that the char yield of the PC/ABS/15% MRP increased from 0 to 16.1 wt % under air atmosphere, and from 15.2 to 27.4 wt % under nitrogen atmosphere compared to virgin PC/ABS, respectively. The sample PC/ABS/15% MRP also showed excellent water resistance of flame retardance in 70°C water for 168 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of membrane pore size on the pH‐sensitivity of polyethersulfone hollow fiber ultrafiltration membrane
Authors: Li Lulu , Xiang Tao , Su Baihai , Li Huijuan , Qian Bosi , Zhao Changsheng 
Published: September 2011

AbstractIn our recent study, pH‐sensitive polyethersulfone (PES) hollow fiber membranes were prepared by blending poly (acrylonitrile‐co‐acrylic acid) (PANAA), and the electroviscous effect had great effect on the water flux change. While the question remains: is the water flux change caused by the electroviscous effect for all the membranes with different pore sizes? Herein, pH‐sensitive hollow fiber membranes with different pore sizes were prepared. The pore size and the theoretic water flux were calculated through the ultrafiltration of polyethylene glycol (PEG) solution. Comparing the calculated fluxes and the experimental ones, we found that the water flux change was mainly caused by the pore size change at the pH value larger than pKa, while that was caused by both the pore size change and the electroviscous effect when pH value was smaller than the pKa, and the pore size change was caused by the ionization of the COOH in the copolymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Photo‐cross‐linked biodegradable thermo‐ and pH‐responsive hydrogels for controlled drug release
Authors: Zhao Changwen , He Pan , Xiao Chunsheng , Gao Xiaoye , Zhuang Xiuli , Chen Xuesi 
Published: September 2011

AbstractA new strategy was developed to prepare thermo‐ and pH‐sensitive hydrogels by the crosslinking of poly(N‐isopropylacrylamide) with a biodegradable crosslinker derived from poly(L‐glutamic acid). Hydrogels were fabricated by exposing aqueous solutions of precursor containing photoinitiator to UV light irradiation. The swelling behaviors of hydrogels at different temperatures, pHs, and ionic strengths were examined. The hydrogels shrank under acidic condition or at temperature above their collapse temperature and would swell in neutral or basic media or at lower temperature. These processes were reversible as the pH or temperature changed. All hydrogels exhibited no weight loss in the simulated gastric fluid but degraded rapidly in the simulated intestinal condition. Bovine serum albumin were used as a model protein drug and loaded into the hydrogels. The in vitro drug release experiment was carried out at different pH values and temperatures. The pH and temperature dependent release behaviors indicated the promising application of these materials as stimuli‐responsive drug delivery vehicles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Direct formation of “artificial wool” nanofiber via two‐spinneret electrospinning
Authors: Li Congju , Wang Jiaona , Zhang Binfei 
Published: September 2011

AbstractTo reproduce the excellent characteristics of natural fibers like wool and proteins, a novel two‐spinneret electrospinning technology was demonstrated in this communication, which can generate three‐dimensional self‐crimp fibers of HSPET/PTT, HSPET/PAN and PU/PAN directly. In the apparatus, two spinnerets were used to prevent gel formation or precipitation of the polymer, and the voltages of opposite polarities were applied to the spinnerets respectively. And the elecctrospun fibers morphology was observed by using scanning electron microscopy (SEM). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of iron carboxylates on the photodegradability of polypropylene. II. Artificial weathering studies
Authors: Rajakumar K. , Sarasvathy V. , Chelvan A. Thamarai , Chitra R. , Vijayakumar C. T. 
Published: September 2011

AbstractThe various iron carboxylates such as ferric caprate, ferric laurate, ferric myristate, ferric palmitate, and ferric stearate were synthesized to enhance the photodegradability of polypropylene (PP). The prodegradants (0.2%) synthesized were blended with virgin PP and then blown into films. All the PP films mentioned were exposed to ultraviolet (UV) radiation of 365 nm at room temperature to study the photodegradation behavior of PP with and without the prodegradants under artificial weathering conditions. The photoirradiated films were found to degrade after certain hours of UV exposure, which could be found from the steep increase of hydroxyl, carbonyl, lactone, ester, carboxylic acid, and crystallinity index. At the same time, a sudden decrease of elongation at break percentages and tensile strength; development of surface cracks indicated the scission of the main chain of the PP. The results revealed that PP containing prodegradants degraded at a faster rate than the virgin material. However, the effectiveness of the prodegradants for the photodegradation of PP was found to be in the order: ferric caprate > ferric laurate > ferric myristate > ferric palmitate > ferric stearate. The results showed that the number of carbon atoms present in the alkyl part of the various prodegradants played a vital role in the degradation phenomenon. Furthermore, it could be concluded that the mobility of the alkyl radicals formed from the decomposition of the incorporated prodegradants during artificial weathering played a prominent role in the photooxidative degradation behavior of PP films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of the base and diluent methacrylate monomers on the polymerization stress and its determinants
Authors: Fróes‐Salgado N. R. G. , Boaro L. C. , Pick B. , Pfeifer C. S. , Francci C. E. , Méier M. M. , Braga R. R. 
Published: September 2011

AbstractThe aim of this study was to evaluate the effect of the association between bisphenol‐A diglycidyl dimethacrylate (BisGMA) or its ethoxylated version (BisEMA) with diluents derived from the ethylene glycol dimethacrylate (EGDMA), with increasing number of ethylene glycol units (1: EGDMA, 2: DEGDMA, 3: TEGDMA, or 4: TETGDMA), or trimethylol propane trimethacrylate (TMPTMA) or 1,10‐decanediol dimethacrylate (D3MA) on polymerization stress, volumetric shrinkage, degree of conversion, maximum rate of polymerization (Rpmax), and elastic modulus of experimental composites. BisGMA containing formulations presented lower shrinkage and stress but higher modulus and Rpmax than those containing BisEMA. TMPTMA presented the lowest stress among all diluents, as a result of lower conversion. EGDMA, DEGDMA, TEGDMA, and TETGDMA presented similar polymerization stress which was higher than the stress presented by D3MA and TMPTMA. D3MA presented similar conversion when copolymerized with both base monomers. The other diluents presented higher conversion when associated with BisEMA. EGDMA showed similar shrinkage compared with DEGDMA and higher than the other diluents. The lower conversion achieved by TMPTMA did not jeopardize its elastic modulus, similar to the other diluents. Despite the similar conversion presented by D3MA in comparison with EGDMA and DEGDMA, its lower elastic modulus may limit its use. Rather than proposing new materials, this study provides a systematic evaluation of off the shelf monomers and their effects on stress development, as highlighted by the analysis of conversion, shrinkage and modulus, to aid the optimization of commercially available materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Studies of fluorine‐containing bismaleimide resins part I: Synthesis and characteristics of model compounds
Authors: Wang Zen‐You , Ho Jiau‐Ching , Shu Wei‐Jye 
Published: September 2011

AbstractA series of fluorine‐containing bismaleimide (FBMI) monomers are synthesized by a 3‐step reaction for using as the applications of low‐k materials. The synthesized FBMI monomers are characterized by the 1H, 13C, 19F nuclear magnetic resonance (NMR) spectroscopy and element analysis. These FBMI monomers react with free radical initiator or self‐cure to prepare FBMI‐polymers. All the self‐curing FBMI resins have the glass transition temperatures (Tg) in the range of 128–141°C and show the 5% weight loss temperatures (T5%) of 235–293°C in nitrogen atmosphere. The higher heat resistance of self‐curing FBMI resin relative to FBMI‐homopolymer is due to its higher crosslinking density. The FBMI resins exhibit improved dielectric properties as compared with commercial bismaleimide (BMI) resins with the dielectric constants (Dk) lower than 2.49, which is related to the low polarizability of the CF bond and the large free volume of CF3 groups in the polymers. Besides, the flame retardancy of all these FBMI resins could be enhanced via the introduction of Br‐atom. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Rheological properties of concentrated solutions of agarose in ionic liquid
Authors: Horinaka Jun‐ichi , Yasuda Ryosuke , Takigawa Toshikazu 
Published: September 2011

AbstractThe rheological properties of agarose solutions were examined under the effect of entanglement coupling between agarose chains. Agarose solutions were prepared by using an ionic liquid 1‐butyl‐3‐methylimidazolium chloride as a solvent. The concentration of agarose was varied from 1.1 × 101–2.1 × 102 kg m−3. The master curves of the angular frequency (ω) dependence of the storage modulus (G′) and the loss modulus (G″) showed a rubbery region in the middle ω region and a flow region at low ω region, respectively. The molecular weight between entanglements (Me) for agarose was calculated from the plateau modulus. Moreover, Me for agarose melt was determined to be 2.3 × 103 from the concentration dependence curve of Me. By using well‐known empirical relations in polymer rheology, information on molecular characteristics of sample agarose was derived. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Increased levels of the cell cycle inhibitor protein, dacapo, accompany 20‐hydroxyecdysone‐induced G1 arrest in a mosquito cell line
Authors: Gerenday Anna , Fallon Ann M. 
Published: September 2011

AbstractWhen treated with the steroid hormone 20‐hydroxyecdysone (20E), C7‐10 cells from the mosquito, Aedes albopictus, arrest in the G1 phase of the cell cycle. To explore whether 20E‐mediated cell cycle arrest proceeds through increased levels of cell cycle inhibitor (CKI) proteins, we cloned the Ae. albopictus homolog of dacapo, the single member of the Cip/Kip family of CKI proteins known from Drosophila melanogaster. The Ae. albopictus dacapo cDNA encoded a 261‐amino acid homolog of the Aedes aegypti protein XP_001651102.1, which is encoded by an ∼23 kb gene containing three exons. Like dacapo from D. melanogaster, the ∼27 kDa protein from Aedes and Culex mosquitoes contained several S/TXXE/D motifs corresponding to potential protein kinase CK2 phosphorylation sites, and a binding site for proliferating cell nuclear antigen (PCNA). When extracts from cells treated with 20E were analyzed by western blotting, using a primary antibody to synthetic peptides from the mosquito dacapo protein, up‐regulation of an ∼27 kDa protein was observed within 24 h, and the abundance of the protein further increased by 48 h after hormone treatment. This is the first investigation of a cell cycle inhibitory protein in mosquitoes. The results reinforce growing evidence that 20E affects expression of proteins that regulate cell cycle progression. © 2011 Wiley Periodicals, Inc.
Synthesis and Free Radical Scavenging Activity of Coumarin Derivatives Containing a 2‐Methylbenzothiazoline Motif
Authors: Khoobi Mehdi , Emami Saeed , Dehghan Gholamreza , Foroumadi Alireza , Ramazani Ali , Shafiee Abbas 
Published: September 2011

AbstractCoumarin and benzothiazole scaffolds can be found in a number of natural or synthetic antioxidants. In an effort to develop a novel radical scavenger and potential antioxidant, a series of coumarin derivatives containing 2‐methylbenzothiazoline motif and related compounds was synthesized and evaluated for their DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) and ABTS•+ (2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radicals scavenging activities. Among them, 7‐hydroxy‐3‐(2‐methyl‐2,3‐dihydrobenzo[d]thiazol‐2‐yl)‐2H‐chromen‐2‐one (3e) has shown a significant free radical scavenging activity. From the structure–activity point of view, it was found that phenolic coumarin ring and benzothiazoline moiety in target compounds may contribute to the scavenging activity against free radicals.
Design, Synthesis and Antifungal Activity of Some New Imidazole and Triazole Derivatives
Authors: Rezaei Zahra , Khabnadideh Soghra , Zomorodian Kamiar , Pakshir Kyvan , Kashi Giti , Sanagoei Narges , Gholami Sanaz 
Published: September 2011

AbstractTriazole and imidazole are incorporated into the structures of many antifungal compounds. In this study a novel series of 1,2,4‐triazole, imidazole, benzoimidazole, and benzotriazole derivatives was designed as inhibitors of cytochrome P450 14α‐demethylase (14DM). These structures were docked into the active site of MT‐CYP51, using Autodock program. Sixteen compounds with the best binding energy were synthesized. The chemical structures of the new compounds were confirmed by elemental and spectral (1H‐NMR and Mass) analyses. All compounds were investigated for antifungal activity against Candida albicans, Candida tropicalis, Candida glabrata, Candida parapeilosis, Candida kruzei, Candida dubliniensis, Aspergillus fomigatus, Aspergillus flavus, Microsporum canis, Microsporum gypseum, Trichophyton mentagrophyte, Epidermophyton floccosum. Some compounds showed excellent in‐vitro antifungal activity against most of the tested fungi. Compounds 2, 9, and 10 had antifungal activity against several resistant fungi against fluconazole and itraconazole.
Synthesis, Characterisation and Biological Evaluation of Copper and Silver Complexes based on Acetylsalicylic Acid
Authors: Rubner Gerhard , Bensdorf Kerstin , Wellner Anja , Bergemann Silke , Gust Ronald 
Published: September 2011

AbstractMetalcarbonyl complexes with ligands derived from acetylsalicylic acid demonstrated high cytotoxic potential against various tumor cell lines and strong inhibition of the cyclooxygenase enzymes COX‐1 and 2. In this study we tried to achieve comparable effects with [alkyne]silver or copper trifluoromethanesulfonate complexes which are more hydrophilic then the uncharged metalcarbonyl derivatives. All compounds were evaluated for growth inhibition against breast (MCF‐7, MDA‐MB 231) and colon cancer (HT‐29) cell lines and for COX‐1 and COX‐2 inhibitory effects at isolated isoenzymes. Pure ligands showed neither cytotoxic nor COX‐inhibitory effects. While the silver complexes of (but‐2‐ynyl)‐2‐acetoxybenzoate (But‐ASS‐Ag) and (but‐2‐yne‐1,4‐diyl)‐bis(2‐acetoxybenzoate) (Di‐ASS‐But‐Ag) were strong cytostatics, only the copper complex Di‐ASS‐But‐Cu was active. At the COX enzymes the complexes were more effective than their ligands and aspirin.
Anti‐Tumor Activity of New Artemisinin–Chalcone Hybrids
Authors: Xie Lijun , Zhai Xin , Liu Chun , Li Peng , Li Yangxiong , Guo Guoxian , Gong Ping 
Published: September 2011

AbstractIn an attempt to develop potent and selective anti‐tumor agents, three new series of artemisinin–chalcone hybrids 10a–10g, 11a–11g and 12a–12h were designed, synthesized and screened for their anti‐tumor activity against five cell lines (HT‐29, A549, MDA‐MB‐231, HeLa and H460) in vitro. Among compounds 10a–g and 11a–11g, most of them displayed enhanced activity and good selectivity toward HT‐29 and HeLa cell lines with IC50 values ranging from 0.12 to 0.85 µM as compared with DHA (dihydroartemisinin). Compounds 10a and 11a are most active toward HeLa cells with IC50 values of 0.12 and 0.19 µM. The results revealed that the presence of chalcone moiety is beneficial to their activity and selectivity. In addition, compounds 12a‐12h containing a ‘reversed chalcone’ moiety showed only slight improvement in activity than those of DHA.
The response of T cells to interleukin‐6 is differentially regulated by the microenvironment of the rheumatoid synovial fluid and tissue
Authors: Hidalgo Ester , Essex Sarah J. , Yeo Lorraine , Curnow S. John , Filer Andrew , Cooper Mark S. , Thomas Andrew M. , McGettrick Helen M. , Salmon Michael , Buckley Christopher D. , Raza Karim , Scheel‐Toellner Dagmar 
Published: September 2011

AbstractObjectiveInterleukin‐6 (IL‐6) is a proinflammatory cytokine with regulatory effects on the survival and differentiation of T cells. It exerts its biologic function in 2 ways: by directly binding to the IL‐6 receptor (IL‐6R; CD126) or via trans‐signaling, in which soluble IL‐6R/IL‐6 complexes bind to the signaling component CD130. This study was undertaken to assess the expression and regulation of CD126 and CD130 and determine how these affect the response of CD4+ T cells to IL‐6 in the joints of patients with rheumatoid arthritis (RA).MethodsFlow cytometry and immunofluorescence microscopy were used to determine the expression, function, and regulation of CD126 and CD130 in CD4+ T cells from the peripheral blood (PB), synovial fluid (SF), and synovial tissue of RA patients.ResultsCompared to the findings in RA PB, CD4+ T cells in the SF and synovial tissue expressed low levels of CD126. In contrast, whereas CD4+ T cell expression of CD130 was minimal in the SF, its level in the synovial tissue was high. Consistent with this phenotype, synovial tissue T cells responded to trans‐signaling by soluble IL‐6R/IL‐6 complexes, whereas no response was evident in CD4+ T cells from the SF. Down‐regulation of both receptor components in SF T cells could be explained by exposure to high levels of IL‐6. Increased levels of CD130 messenger RNA and protein in synovial tissue CD4+ T cells suggested that CD130 is up‐regulated locally. Among a range of cytokines tested, only IL‐10 induced CD130 expression in T cells.ConclusionThe inflamed microenvironment in the synovial tissue maintains responsiveness to IL‐6 trans‐signaling through the up‐regulation of CD130 expression in CD4+ T cells, and this process may be driven by IL‐10.