bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonisothermal curing kinetics of a novel polymer containing phenylsilylene and propargyl–hexafluorobisphenol a units
Authors: Yang Guang , Yuan Zehong , Yang Zhiyong , Zhang Maning 
Published: May 2012

AbstractA novel thermosetting polymer, poly[(phenylsilylene) propargyl–hexafluorobisphenol A] (PBAFS), with a new structure was synthesized. The structure of PBAFS and its cured resins were characterized by Fourier transform infrared spectra. During curing, a hydrosilylation reaction may occur between SiH and CC bonds and a Claisen rearrangement reaction of aryl propargyl ether led to formation of chromene, which immediately preceded polymerization on heating. The dynamic viscosity behavior was investigated by rheological experiment. Thermal stability of the cured PBAFS was also measured by Thermogravimetric analysis. The curing behavior of PBAFS was monitored by nonisothermal differential scanning calorimetry at different heating rates. The kinetic parameters and the kinetic model of the cure reaction were evaluated by Kissinger, Ozawa, and Friedman methods. The cure reaction of PBAFS was found nth‐order in nature and the prediction curves by Friedman method for nonisothermal curing reaction were in good agreement with the experimental curves. The isothermal curing time of PBAFS were predicted by Vyazovkin and model‐fitting methods from the nonisothermal kinetic parameters. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Chlorosulfonated polyethylene–polypropylene thermoplastic vulcanizate: Mechanical, morphological, thermal, and rheological properties
Authors: Mandal Asis K. , Siddhanta Samir K. , Chakraborty Debabrata 
Published: May 2012

AbstractDifferent thermoplastic vulcanizate (TPV) blends were prepared from elastomeric chlorosulfonated polyethylene (CSM) and thermoplastic polypropylene (PP) by employing dynamic vulcanization technique. The mechanical properties of such blends were compared in respect of their stress at 25% modulus (25%M), ultimate tensile strength (UTS), percent elongation at break, and hardness to those of pure CSM. The mechanical analysis showed substantial improvement in stress at 25%M, UTS, and hardness values with the incorporation of 15–40 parts of thermoplastic contents (PP) (per hundred parts of blend). The two‐phase morphologies were clearly observed by scanning electron microscopy studies. The thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC studies showed a decreasing trend in glass transition temperature (Tg) and TGA studies indicated the increase in thermal stability of all TPV blends with respect to the elastomeric CSM. Rheological studies showed that there is an increasing trend in shear melt viscosity of TPV blends with the increase in PP amount as the higher content of isotactic PP used in the present case increases the melt viscosity. The TPVs obtained after the rheotron studies displayed identical shear stress/strain pattern when further subjected to the same study. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Biocidal nanofibers via electrospinning
Authors: Ren Xuehong , Kocer Hasan B. , Worley S. D. , Broughton R. M. , S. Huang T. 
Published: May 2012

AbstractTo achieve biocidal properties, a cyclic N‐halamine precursor, 7,7,9,9‐tetramethyl‐1,3,8‐triazaspiro[4.5]‐decane‐2,4‐dione (TTDD), was synthesized and introduced into nanosized polyacrylonitrile fibrous mat by an electrospinning technique. It was rendered antimicrobial by exposure to dilute hypochlorite solution. Synthesis routes and characterization data are presented. Scanning electron microscopy (SEM) demonstrated that the ultrafine fiber possessed average diameter 414 nm (from 240 to 650 nm). The chlorinated nanofibrous composites provided about 4.9 log reductions of both Gram‐positive bacteria Staphylococcus aureus (ATCC 6538) and Gram‐negative bacteria Escherichia coli O157:H7 (ATCC 43895) within 5 min of contact time. This is indicative of promising possible applications in the filtration of water and air. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Comparison of morphology and mechanical properties of peroxide‐cured acrylonitrile butadiene rubber/LDH composites prepared from different organically modified LDHs
Authors: Feng Jianxiang , Liao Zedong , Zhu Jin , Su Shengpei 
Published: May 2012

AbstractRubber compounds based on acrylonitrile butadiene rubber (NBR) containing organically modified layered double hydroxides (LDHs) were prepared using peroxide as a curing agent. The LDHs intercalated by organic compounds including sodium styrene sulfonate (SSS) and sodium dodecylbenzene sulfonate (SDBS) were investigated using thermogravimetric analysis (TGA) and X‐ray diffraction (XRD) while the unmodified LDHs were used as contrast. Experimental results from TGA and XRD showed that both SSS‐ and SDBS‐intercalated LDHs were successfully obtained. The morphology of the LDH composites was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and XRD. The chemical structure of NBR/LDHs compounds were measured by Fourier transform infrared spectrum. The thermal properties were measured by TGA and differential scanning calorimetry. Other properties such as mechanical and swelling properties were also investigated. The results showed that a chemical bonding between organically modified LDHs and rubber matrix through SSS was built during vulcanization, which leads to improved interfacial strength of the cured compound. A high‐performance acrylonitrile butadiene rubber/SSS‐modified LDH compound, which has two times higher tensile strength than cured pure rubber without significant loss of elongation, was obtained. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of nanoclay content and matrix composition on properties and stress–strain behavior of NR/EPDM nanocomposites
Authors: Alipour Abdolmajid , Naderi Ghasem , Ghoreishy Mir HamidReza 
Published: May 2012

AbstractNanocomposites based on NR/EPDM/Cloisite 15A have been prepared via a vulcanization process to investigate the effect of nanoclay content and rubber composition on the properties of samples. The prepared nanocomposite samples are characterized by several techniques. The experimental results of X‐ray diffraction and transmission electron microscopy showed the widening of distance between the silicate layers, penetration of polymer chains into silicate layers, and formation of an intercalated and partially exfoliated structure. Results indicated that addition of nanoclay could improve the mechanical strength of the rubber. Also increase of nanoclay and EPDM content were found to improve the thermal aging of the samples and also the performance of the rubbers under compression. Nanoclay also reduced the hysteresis and heat build up of the rubber compounds. Moreover, to investigate the stress–strain behavior of NR/EPDM nanocomposites using constitutive models, applicability and best fit of five different hyperelastic constitutive models including second order Polynominal, Yeoh, third order Ogden, Marlow, and Arruda‐Boyce against experimental data for NR/EPDM/nanoclay blends were studied. Due to the different amounts of nanoclay (1, 3, 5, and 7 wt %) and different NR/EPDM compositions (100/0), (75/25), (50/50), (25/75), and (0/100), different experimentally measured data of samples were compared with those predicted by the mathematical models previously mentioned. Results showed that third order Ogden and Marlow models can be used for different amounts of nanoclay and rubber compositions, whereas Arruda‐Boyce and Yeoh models show more deviation from experimental data with a reduction in nanoclay and increase in EPDM content. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fabrication and characterization of natural origin chitosan‐ gelatin‐alginate composite scaffold by foaming method without using surfactant
Authors: Sharma Chhavi , Dinda Amit Kumar , Mishra Narayan Chandra 
Published: May 2012

AbstractA natural origin tripolymer scaffold from chitosan, gelatin, and alginate was fabricated by applying foaming method without adding any foam stabilizing surfactant. Previously, in foaming method of scaffold fabrication, toxic surfactants were used to stabilize the foam, but in this work, the use of surfactant has been avoided strictly, which can provide better environment for cellular response and viability. In foaming method, stable foam is produced simply by agitating the polymer (alginate‐gelatin) solution, and the foam is crosslinked with CaCl2, glutaraldehyde, and chitosan to produce tripolymer alginate‐gelatin‐chitosan composite scaffold. Microscopic images of the composite scaffold revealed the presence of interconnected pores, mostly spread over the entire surface of the scaffold. The scaffold has a porosity of 90% with a mean pore size of 57 μm. Swelling and degradation studies of the scaffold showed that the scaffold possesses excellent properties of hydrophilicity and biodegradability. In vitro cell culture studies by seeding L929 mouse fibroblast cells on scaffold revealed excellent cell viability, proliferation rate and adhesion as indicated by MTT assay, DNA quantification, and phase contrast microscopy of cell‐scaffold construct. The natural origin composite scaffold fabricated by the simplest method i.e., foaming method, but without adding any surfactant, is cheap, biocompatible, and it might find potential applications in the field of tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fabrication of size‐controllable mPEG‐decorated microparticles conjugating optically active ketoprofen based on self‐assembly of amphiphilic random copolymers
Authors: Li Xia , Zhou Guo‐Jun , Chu Guo‐Hai , Lin Xian‐Fu , Wang Jun‐Liang , Shen Kai , Yin Jie 
Published: May 2012

AbstractNovel size‐controllable mPEG‐decorated polymeric microparticles binding optically active ketoprofen were successfully fabricated based on chemoenzymatic synthesis and self‐assembly of amphiphilic random polymer–ketoprofen conjugates with mPEG and (S)‐ketoprofen as pendants. A series of mPEG350‐ or mPEG1000‐functionalized amphiphilic random polymer–ketoprofen conjugates with drug loading capacity from 16.5% to 73.2% were easily prepared by combining enzymatic resolution with radical polymerization and characterized by Fourier Transform Infrared spectroscopy, 1H‐NMR, and gel permeation chromatography. The formation of aggregates from the amphiphilic random polymer–ketoprofen conjugates was investigated by ultraviolet‐visible absorption spectra using pyrene as the guest molecule. Transmission electron microscopy measurement revealed that the self‐assemblies were well dispersed as spherical microparticles. The size of the self‐assemblies could be widely tuned by varying the length of mPEG chains and the content of ketoprofen in the synthetic polymer–ketoprofen conjugates, and a series of mPEG‐decorated (S)‐ketoprofen‐bound polymeric microparticles with average radius from 70 nm to 1.1 μm were obtained. The successful preparation of the microparticles containing (S)‐ketoprofen provided a new strategy for the design and fabrication of optically active drug delivery systems. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis, characterization, and corrosion inhibition study of polyaniline‐α‐Fe2O3 nanocomposite
Authors: Umare S. S. , Shambharkar B. H. 
Published: May 2012

AbstractPolyaniline (PANI)‐α‐Fe2O3 nanocomposites (NCs) have been synthesized by chemical oxidative in situ polymerization of aniline in presence of α‐Fe2O3 nanoparticles at 5°C using (NH4)2S2O8 as an oxidant in an aqueous solution of sodium dodecylbenzene sulphonic acid (SDBS), as surfactant and dopant under N2 atmosphere. The room temperature conductivity of NCs decreases and coercive force (Hc) increases with an increase addition of α‐Fe2O3 in PANI matrix. The result of FTIR and TGA shows that the interaction between α‐Fe2O3 particles and PANI matrix could improve the thermal stability of NCs. NCs demonstrate the superparamagnetic behavior. The performance of PANI and PANI‐α‐Fe2O3 NCs as protective coating, against corrosion of 316LN stainless steel in 3.5% NaCl was assessed by potentiodynamic polarization technique. The study shows a good corrosion inhibition effect of both the coatings. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Electropolymerization and properties of 3,4‐ethylenedioxythiophene backbone polymer with tetrathiafulvalene as pendant
Authors: Zhang Lei , Li Meijiang , Wang Chengyun , Wang Yanhong , Shen Yongjia 
Published: May 2012

AbstractThree 3,4‐ethylenedioxythiophene (EDOT) derivatives, including an EDOT‐tetrathiafulvalene (TTF) derivative, were synthesized by Steglich esterification of carboxylic acids with hydroxymethyl EDOT (3,4‐ethylenedioxythiophene methanol). The UV spectra showed that there was no distinctive intramolecular interaction for the EDOT–TTF monomer between the EDOT and the TTF moieties in the ground state; however, the cyclic voltammetry responses implied that such intramolecular interaction occurred. Electropolymerization in excessive potential could bring in strong overoxidation effects and degradation in the polymer film. The polymers were simulated using density functional theory with Gaussian03 package and the optimized HOMO and LUMO state were figured out. The conductivity of TTF‐polymer was 6 S·cm−1 obtained by galvano station and 4.8 × 10−3 S·cm−1 obtained by potentiostatic electropolymerization after doping with 7,7,8,8‐tetracyanoquinodimethane. The results indicated that this polymer was a reasonable candidate for conducting materials and it was meaningful to increase the conductive dimensions of TTF polymers by chemical doping. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Induction of extremely low protein expression level by fusion of C‐terminal region of Nef
Authors: Takamune Nobutoki , Irisaka Yukari , Yamamoto Minami , Harada Keisuke , Shoji Shozo , Misumi Shogo 
Published: May 2012

AbstractNef is one of the accessory proteins of human immunodeficiency viruses. Here, we noted that the relative expression level of NefNL4‐3 is much lower than that of NefJR‐CSF in HEK293 cells. By evaluating the expression level using a Nef mutant, it was indicated that amino acids 129‐206 of NefNL4‐3, that is, the C‐terminal region named NLAA129‐206, could contain the region responsible for the induction of the low protein expression level. In addition, the expression levels of the enhanced green fluorescent protein and Renilla luciferase became extremely low with the fusion of NLAA129‐206. Interestingly, the NLAA129‐206‐corresponding sequences of other Nef variants with relatively high expression levels also induced the extremely low protein expression level by fusion. These results suggest that the C‐terminal region of Nef can generally induce an extremely low protein expression level. Here, we propose that the C‐terminal region of Nef could become an excellent tool for the induction of an extremely low expression level of arbitrary proteins by attachment as fusion proteins.
Oxidative ring‐opening of 2‐methylcyclohexanone catalysed by supported heteropolyacid catalysts for cetane number enhancement
Authors: Ren Rui , Yang Hong , Zheng Ying , Ng Siauw , Zhao Jianshe 
Published: May 2012

AbstractIncipient wetness impregnation method was used to incorporate heteropolyacid H6[PV3Mo9O40]nH2O (HPA) on SiO2 at various HPA loadings (10, 20, 30, 40 wt.% HPA) and calcined temperatures. Catalytic activity of these synthesised catalysts were evaluated through oxidation of 2‐methylcyclohexanone to methyl 6‐oxoheptanoate which was a desired product. In the oxidative conditions the conversion and selectivity of the desired product methyl 6‐oxoheptanoate can reach as high as 97 and 94 wt.%, respectively. The results also suggested that the catalyst with 20 wt.% loading of HPA to be the best one. The catalysts were characterised using a variety of techniques including XRD, BET, FT‐IR and TGA‐DTA. The results indicated that HPA was well dispersed on the SiO2 supporting material. An engine ignition test following ASTM D6890 standard indicated that the oxidative ring‐opening of cyclohydrocarbons can have a positive impact on the cetane numbers and ignition delay time of fuels. © 2012 Canadian Society for Chemical Engineering
Simultaneous synthesis of structural‐constrained heat exchanger networks with and without stream splits
Authors: Zhaoyi Huo , Liang Zhao , Hongchao Yin , Jianxiong Ye 
Published: May 2012

AbstractThis paper presents a comprehensive simultaneous synthesis approach based on stage‐wise superstructure to design cost‐optimal heat exchanger network (HEN). It is well known that the simultaneous synthesis model has very complicated mixed integer nonlinear programming formulations, which are non‐convex, non‐continuous and have many local optima. Up till now, it cannot be expected that an algorithm can find, in polynomial time, the global solution to the simultaneous synthesis problem of HEN. In order to reduce computational complexity, some simplified assumptions for structures, such as no stream splits, stream splits with isothermal mixing, no stream split flowing through more than one exchanger, etc, are adopted to prune the search space at the expense of neglecting certain important alternatives in the network configuration. In this work, a flexible stage‐wise superstructure is proposed to control the solution performance and search space efficiently. At each stage of the superstructure, with or without stream splits is determined at random or by the experience of designers. In this way, various candidate series and split network designs featuring the lowest annual cost can be found. Moreover, an efficient two‐level optimisation algorithm is employed for solving the presented model utilising genetic algorithm and particle swarm optimisation algorithm. Three case studies are presented to show the applicability of the proposed methodology. In addition, the results show that the new approach is able to find more economical networks than those generated by other methods. © 2012 Canadian Society for Chemical Engineering
Bioreduction of Hexavalent Chromium by Live and Active Phanerochaete chrysosporium: Kinetics and Modeling
Authors: Murugavelh Somasundaram , Mohanty Kaustubha 
Published: May 2012

AbstractIn this work the potential of live and active Phanerochaete chryosporium, a white rot fungi, to remove lower Cr(VI) concentration from aqueous solutions was reported for the first time. A medium pH had significant effect on the growth of the fungus and bioremoval of Cr(VI). Substrate inhibition on the growth of Phanerochaete chrysosporium was evident beyond 20 g L−1 of dextrose concentration. A maximum biomass concentration of 15.64 g L−1 was obtained for an initial dextrose concentration of 20 g L−1 in metal free medium at pH 6.0. An increase in Cr(VI) concentration beyond 10 mg L−1 inhibited the growth of the fungi, thereby, reducing the chromium bioremoval efficiency. A maximum reduction efficiency of 98.92% was reported for an initial metal concentration of 10 mg L−1. A mathematical expression for the bioreduction of Cr(VI) considering the organic compounds in the cells was proposed.
On the efficient use of multiple channels by single‐receiver clients in wireless data broadcasting
Authors: Nicopolitidis P. , Chrysostomou C. , Papadimitriou G.I. , Pitsillides A. , Pomportsis A.S. 
Published: May 2012

SUMMARYThis letter proposes an adaptive wireless push system for wireless data broadcasting environments, where multiple channels are available for broadcasting data from a broadcast server to a large number of mobile clients. We address the general case where the client demands are not dependent on client locations. The efficiency of the proposed system lies in the fact that it offers significant performance improvements to the system clients with the need of only one receiver at each client device. Copyright © 2012 John Wiley & Sons, Ltd.
Body mass index and survival in patients with renal cell carcinoma: A clinical‐based cohort and meta‐analysis
Authors: Choi Yuni , Park Bumsoo , Jeong Byong Chang , Seo Seong Il , Jeon Seong Soo , Choi Han Yong , Adami Hans‐Olov , Lee Jung Eun , Lee Hyun Moo 
Published: May 2012

AbstractGrowing evidence suggests that obesity, an established cause of renal cell cancer (RCC), may also be associated with a better prognosis. To evaluate the association between RCC survival and obesity, we analyzed a large cohort of patients with RCC and undertook a meta‐analysis of the published evidence. We collected clinical and pathologic data from 1,543 patients who underwent nephrectomy for RCC between 1994 and 2008 with complete follow‐up through 2008. Patients were grouped according to BMI (kg/m2): underweight <18.5, normal weight 18.5 to <23, overweight 23 to <25 and obese ≥25. We estimated survival using the Kaplan–Meier method and Cox proportional hazard models to examine the impact of BMI on overall survival (OS) and cancer‐specific survival (CSS) with adjustment for covariates. We performed a meta‐analysis of BMI and OS, CSS and recurrence‐free survival (RFS) from all relevant studies using a random‐effects model. The 5‐year CSS increased from 76.1% in the lowest to 92.7% in the highest BMI category. A multivariate analysis showed higher OS [hazard ratio (HR) = 0.45; 95% CI: 0.29–0.68) and CSS (HR = 0.47; 95% CI: 0.29–0.77] in obese patients than in normal weight patients. The meta‐analysis further corroborated that high BMI significantly improved OS (HR = 0.57; 95% CI: 0.43–0.76), CSS (HR = 0.59; 95% CI: 0.48–0.74) and RFS (HR = 0.49; 95% CI: 0.30–0.81). Our study shows that preoperative BMI is an independent prognostic indicator for survival among patients with RCC.
Therapeutic live vaccines as a potential anticancer strategy
Authors: Bolhassani Azam , Zahedifard Farnaz 
Published: May 2012

AbstractThe design of efficient cancer treatments is one of the major challenges of medical science. Therapeutic vaccines of cancer have been emerged as an attractive approach for their capacity of breaking the immune tolerance and invoking long‐term immune response targeting cancer cells without autoimmunity. An efficient antigen delivery system is the key issue of developing an effective cancer vaccine. In this regard, live vaccination strategies including various live bacterial and viral vectors have attracted a great attention. Several bacterial strains such as Salmonella, Listeria
monocytogenes and Lactococcus lactis effectively colonize solid tumors and act as antitumor therapeutics. On the other hand, the use of viruses as vaccine vectors such as Vaccinia, Adenovirus, Herpes simplex virus, Paramyxovirus and Retroviruses utilizes mechanisms that evolved in these microbes for entering cells and capturing the cellular machinery to express viral proteins. Viral/bacterial‐vectored vaccines induce systemic T‐cell responses including polyfunctional cytokine‐secreting CD4+ and CD8+ T‐cells. However, there is an urgent need for the development of new safe live vaccine vectors that are capable of enhancing antigen presentation and eliciting potent immune responses without the risk of development of disease in humans. Recently, nonpathogenic parasites including Leishmania
tarentolae, Toxoplasma gondii and Trypanosoma cruzi have emerged to be a novel candidate for gene delivery and heterologous genes expression. In this review, recent researches on cancer therapy using genetically modified bacteria and virus are summarized. In addition, live parasite‐based vectors will be discussed as a novel anticancer therapeutic approach.