bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructing the Phase Diagram of an Aqueous Solution of Poly(N‐isopropyl acrylamide) by Controlled Microevaporation in a Nanoliter Microchamber
Authors: Zhou Xuechang , Li Junfang , Wu Chi , Zheng Bo 
Published: June 2008

AbstractThis paper describes a poly(dimethylsiloxane) (PDMS)‐based microfluidic platform for constructing the phase diagram of poly(N‐isopropyl acrylamide) (PNIPAM) in aqueous solution. The PNIPAM solution was delivered into a nanoliter chamber through the main microchannel. An osmotic pressure difference was established between the chamber and the control microchannel by flowing a high‐concentration salt solution in the control microchannel. Controlled evaporation of water resulted in increasing concentration of PNIPAM. A phase diagram of PNIPAM was built by measuring the cloud points at different concentrations, with a minimum point at ≈40 wt.‐%. The microfluidic platform has the advantages of low sample consumption and rapid heat exchange rates, and allows studying viscous polymer solution.magnified image
Interrupted Wet‐Spinning Process for Chitosan Hollow Fiber Elaboration
Authors: Araiza Rocio Nohemi Rivas , Rochas Cyrille , David Laurent , Domard Alain 
Published: June 2008

AbstractSummary:Chitosan hollow fiber formation with a variable internal diameter was performed from a new wet‐spinning method in interrupted coagulation conditions by means of water washings. The main objective of the present study is to provide a better understanding of the physicochemical events involved during the chitosan fiber formation by this new wet‐spinning method.
Hydrogel of Guar Gum in Experimental Osteoarthritis in Rats
Authors: Cunha Pablyana L. R. , Castro Rondinelle R. , Rocha Francisco A. C. , Feitosa Judith P. A. 
Published: June 2008

AbstractSummary:Commercial Guar Gum, a galactomannan polysaccharide, was purified by the use of two subsequent methods, including precipitation with Fehling solution in order to eliminate protein impurities. The protein content (3.6%) was totally removed. Glutaraldehyde cross‐linked gels were prepared with purified (GGP) and unpurified gum (GGU). The viscosity of the gels is similar to that of Hylan G‐F 20, a commercial substitute of hyaluronic acid, used in viscosupplementation in human osteoarthritis. Guar Gums (gel and solution) were injected intra‐articularly into the knee joints of rats subjected to experimental OA and the effect in hypernociception and cells influx measured. GGU promoted hypernociception and cell influx in naïve rats. GGP was innocuous to naïve rats and inhibited hypernociception, both as a gel or solution, to the same extent as Hylan G‐F20. GGP promotes analgesia in OA due to its carbohydrate component.
Synthesis of a New Hydrogel, Based on Guar Gum, for Controlled Drug Release
Authors: Panariello G. , Favaloro R. , Forbicioni M. , Caputo E. , Barbucci R. 
Published: June 2008

AbstractSummary:Guar gum (GG) polymer was crosslinked in order to obtain a new hydrogel. The GG hydrogel has been characterized by means of FT‐IR spectroscopy, the determination of the water content, at different pH values, rheological measurements and in vitro release studies. The GG hydrogel shows a maximum water uptake at acid and basic pH values. The mechanical properties are investigated in order to verify the thixotropic behaviour of the material. In vitro release studies are conducted to evaluate the application of the GG hydrogel as a matrix for controlled drug release.
Kinetic Study of Bovine Serum Albumin (BSA) Released from Alginate‐Ca2+/PNIPAAm Hydrogels
Authors: Piai Juliana F. , de Moura Márcia R. , Rubira Adley F. , Muniz Edvani C. 
Published: June 2008

AbstractSummary:In this work the releasing of Bovine Serum Albumin (BSA) from thermosensitive hydrogels of alginate‐Ca2+/PNIPAAm was investigated. The hydrogels are constituted of PNPAAm network interpenetrated in alginate‐Ca2+ network, so the hydrogels are IPN‐typed. The PNIPAAm network was synthesized in the first step in which the sodium alginate remained soluble. The alginate‐Ca2+ network was formed in the second step by immersion the membrane obtained on the first step in aqueous calcium chloride. It was changed the amount of NIPAAm in the feed solution of the first step. The fractions of BSA released as a function of time were treated according to the mathematical model recently published by our lab [J. Coll. Interf. Sci. 2007, 310, 128] that allows predicting the whole profile of solute released from polymer networks. This mathematical model is based in the partition phenomena. The amount of BSA released from alginate‐Ca2+/PNIPAAm hydrogels changes inversely to both amount of PNIPAAm and temperature. Thus, the IPN‐typed matrixes of alginate‐Ca2+/PNIPAAm may be considered as smart hydrogels for release the BSA because the amount and rate of released BSA can be tailored by the amount of PNIPAAm in the hydrogel and by the control of temperature. Finally, the whole profile of released BSA can be adequately fitted by the model based in the partition phenomenon. From that model the kinetic parameter t1/2 and rate constant of releasing, kR, were calculated for the different hydrogels investigated in this work.
Relaxation behavior study of silicone rubber crosslinked network under static and dynamic compression by electric response
Authors: Chen Ling , Chen Guohua 
Published: June 2008

AbstractThe macroscopical deformation and the microcosmic molecule motions of the polymer matrix under static and dynamic compression can be studied by observing and analyzing the corresponding electric response of its electrically conductive composite. The resistance of silicone rubber/graphite nanosheet nanocomposite under static and dynamic compression changes in different ways, which reflects clearly the corresponding deformation characteristics: under static compression, resistance relaxation occurs, according to which it is concluded that the constant strain transforms over time from the initial elastic one to the viscoelastic one; under dynamic compression, the resistance rises with continuously increasing strain, in terms of which it is considered that short relaxation times may not allow the transformation of strain to happen and the elastic strain is dominative. A similar expression of Burgers equation was adopted here for describing resistance relaxation of SR/GN nanocomposite and the Burger's model without the dashpot in series for the crosslinked polymer network was also used to model the corresponding deformation characteristics of the polymer matrix. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding
Authors: Sreekumar P.A. , Saiah Redouan , Saiter Jean Marc , Leblanc Nathalie , Joseph Kuruvilla , Unnikrishnan G. , Thomas Sabu 
Published: June 2008

AbstractThe dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding (RTM) were investigated as a function of fiber content, frequency, and temperature. Investigation proved that at all temperature range the storage modulus (E′) value is maximum for the composites having fiber loading of 40 vol%. The loss modulus (E″) and damping peaks (tan δ) were lowered with increasing fiber content. The height of the damping peaks depends upon the fiber content and the fiber/matrix adhesion. The extent of the reinforcement was estimated from the experimental storage modulus, and it has been found that the effect of reinforcement is maximum at 40 vol% fiber content. As the fiber content increases the Tg from tan δ curve showed a positive shift. The loss modulus, storage modulus, and damping peaks were evaluated as a function of frequency. The activation energy for the glass transition increases upon the fiber content. Cole–Cole analysis was made to understand the phase behavior of the fiber reinforced composites. Finally, attempts were made to correlate the experimental dynamic properties with theoretical predictions. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Structure, interaction and thermal study in electrolyte of polyethylene oxide/silica/ammonium thiocynate nanocomposites
Authors: Pandey Kamlesh , Dwivedi Mrigank Mauli , Tripathi Mridula 
Published: June 2008

AbstractComposite polymer electrolyte consisting of polymer (polyethylene oxide, PEO) and nanosized ceramic filler with different concentrations of salt have been synthesized and characterized. X‐ray diffraction analysis shows that polymer salt complex has been intercalated into the naometric silicate layers. IR spectra reveal that the polymer structure in the ceramic interlayer is similar to that of polymer salt complexes and there is a strong interaction between PEO:SiO2 and polymer‐salt complexes. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and thermal decomposition of PS/AG microspheres
Authors: Zhao Wen , Zhang Qiuyu , Zhang Junping , Zhang Hepeng 
Published: June 2008

AbstractPS/Ag microspheres were prepared by electroless silver plating on PS microspheres. SEM, EDS, and XRD approved the successful formation of silver coatings on PS microspheres. The thermogravimetric analysis was studied using a TGA system. The Ozawa and Coats‐Redfern methods were exploited to calculate activation energy and determine thermal decomposition mechanism. The thermal decomposition mechanism of pure PS microspheres was also investigated to draw comparisons with the mechanism of PS/Ag microspheres. It has been found that the thermal decomposition mechanism of PS/Ag microspheres and PS microspheres were both A2 model. The activation energy of PS microspheres and PS/Ag microspheres is 76.76 kJ/mol and 78.61 kJ/mol, respectively. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Elastomeric composites based on ethylene–propylene–diene monomer rubber and conducting polymer‐modified carbon black
Authors: Domenech S.C. , Bendo L. , Mattos D.J.S. , Borges N.G. , Zucolotto V. , Mattoso L.H.C. , Soldi V. 
Published: June 2008

AbstractThermally stable elastomeric composites based on ethylene–propylene–diene monomer (EPDM) and conducting polymer‐modified carbon black (CPMCB) additives were produced by casting and crosslinked by compression molding. CPMCB represent a novel thermally stable conductive compound made via “in situ” deposition of intrinsically conducting polymers (ICP) such as polyaniline or polypyrrole on carbon black particles. Thermogravimetric analysis showed that the composites are thermally stable with no appreciable degradation at ca. 300°C. Incorporating CPMCB has been found to be advantageous to the processing of composites, as the presence of ICP lead to a better distribution of the filler within the rubber matrix, as confirmed by morphological analysis. These materials have a percolation threshold range of 5–10 phr depending on the formulation and electrical dc conductivity values in the range of 1 × 10−3 to 1 × 10−2 S cm−1 above the percolation threshold. A less pronounced reinforcing effect was observed in composites produced with ICP‐modified additives in relation to those produced only with carbon black. The results obtained in this study show the feasibility of this method for producing stable, electrically conducting composites with elastomeric characteristics. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and characterization of poly(styrene‐b‐butadiene‐b‐styrene)/montmorillonite nanocomposites
Authors: Chen Zhonghua , Feng Runcai 
Published: June 2008

AbstractWith some polymerizable small molecules grafting onto the montmorillonite surface, we disposed the clay through in‐situ emulsion polymerization, and the structure of the modified montmorillonites were studied through Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). The nanocomposites of poly(styrene‐b‐butadiene‐b‐styrene) (SBS)/montmorillonite with excellent mechanical properties were prepared by mixing SBS and the modified montmorillonite on the double rollers at 150°C. The exfoliation of the layered silicates was confirmed by XRD analysis and transmission electron microscopy (TEM) observation. After mechanical kneading of the molten nanocomposites, the exfoliation structure of the silicates is still stable for polystyrene macromolecules grafting onto the silicates. Upon the addition of the modified montmorillonite, the tensile strength, elongation at break and tear strength of the nanocomposites increased from 22.6 MPa to 31.1 MPa, from 608% to 948%, from 45.32 N/mm to 55.27 N/mm, respectively. The low‐temperature point of glass‐transition temperature (Tg) of the products was about −77°C, almost constant, but the high‐temperature point increased from 97°C to 106°C. In addition, the nanocomposites of SBS and modified montmorillonites showed good resistance to thermal oxidation and aging. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effects of magnesium hydroxide and its surface modification on crystallization and rheological behaviors of polypropylene
Authors: Chen Xiaolang , Yu Jie , Guo Shaoyun , Luo Zhu , He Min 
Published: June 2008

AbstractIn this article, polypropylene composites filled with magnesium hydroxide (PP filled with MH) were prepared in corotating twin‐screw extruder. The effects of MH particles content and types of treatment agents on the crystallization and melting behaviors, crystal structure, and rheological properties of PP/MH composites were studied by differential scanning calorimetry (DSC), a wide‐angle X‐ray diffraction, and dynamic rheological measurements. The DSC results show that MH particles act as a good heterogeneous nucleation effect on PP. Surface treatment of MH weakens its heterogeneous nucleation effect. The nucleating efficiency of MH on PP is found to depend strongly on its content and type of treatment agents. The dynamic rheological behaviors of MH filled PP is found that the complex viscosity (η*) increases with increasing MH content, whereas with increasing filler concentration the network structure becomes the prevailing process, which raises the η* values, especially at the low frequency zone. The η* values of the composites, however, decrease with the addition of various treatment agents. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effect of nanoparticles on mode‐I fracture toughness of polyurethane foams
Authors: Saha Mrinal C. , Kabir Md. E. , Jeelani Shaik 
Published: June 2008

AbstractMode‐I fracture toughness of rigid polyurethane (PUR) foam modified with nanosize particles of different shapes and sizes have been examined using a single edge notched bend (SENB) specimen under three‐point bending configuration. The PUR foams with density of 260 kg/m3 and four different types of nanoparticles, namely, nano TiO2 (5, 10, and 35 nm), nanoclay, carbon nanofibers (CNFs), and multiwall carbon nanotubes (MWNTs) are considered. Nanophased PUR foams are prepared through the infusion of nanoparticles into liquid PUR foam precursor in the range of 0.5–2 wt% with 0.5‐wt% increment using a sonochemical method. The linear elastic fracture mechanics (LEFM) model has been used to determine the mode‐I fracture toughness. The fracture toughness data have been validated with the plain strain fracture criteria and found to be appropriate. It is observed that the infusion of CNF at 0.5‐wt% loading shows the highest enhancement in fracture toughness (about 28%) over neat counter part. Among different sized nano TiO2, 5 nm nanoparticles show the highest improvement (about 16%) at a doping of 1.0 wt%. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Melt compounding of various polymers with organoclay by shear flow
Authors: Koyama Terumasa , Tanoue Shuichi , Iemoto Yoshiyuki , Maekawa Tomokazu , Unryu Tsunemune 
Published: June 2008

AbstractWe studied melt compounding of polymer/organoclay composites by shear flow in a rotating cylindrical mixer to investigate an effect of shear stress on the dispersion state of clay. The commercial organoclay, which is intercalated by dimethyl benzyl stearyl ammonium ion between clay platelets, and four kinds of commercial polymer (polystyrene (PS), poly(lactic acid) (PLA), polyamide(PA6), and poly(butylene succinate) (PBS)) were used in this study. According to the TEM photographs, there is exfoliated clay in PA6/organoclay composite, but the exfoliated clay cannot be seen in other polymer/organoclay composites. We calculated the value of clay dispersion from the low magnification TEM photograph, called the dispersion coefficient to consider the micro level dispersion of the clay in a polymer matrix. Generally, the dispersion coefficient increases with shear stress. However, the dispersion coefficients in case using PA6 and PBS as the matrix, whose melts have low viscosity, are larger than those in case using PS and PLA, whose melts have high viscosity. According to XRD results, d001 peak originated from organoclay mostly shifted to the low value of angle for PA6/organoclay composite and began shifting to the low value of angle for PBS/organoclay composite. However, there is a peak for PS and PLA based organoclay composites. From the cases of PA6 and PBS in the DMA results, the storage modulus increases with an addition of organoclay. These results imply that low viscosity polymer is typical easy to get the composites with intercalated clay by melt compounding. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Phytomodulatory potentials of Aloe vera against Salmonella OmpR‐mediated inflammation
Authors: Rishi Praveen , Rampuria Anjali , Tewari Rupinder , Koul Ashwani 
Published: June 2008

AbstractMediators released during inflammatory response play an essential role in eliminating microbes or microbial products. However, the uncontrolled release of cytotoxic substances characterized by extensive inflammation may adversely affect normal tissues. Under such conditions it is important to manage the hyperinflammation in order to change the clinical manifestations of the disease. Accordingly, the present study was designed to evaluate the modulation of Salmonella OmpR mediated inflammation by Aloe vera, a plant known to contain antiinflammatory ingredients. It was observed that outer‐membrane proteins (OMPs) extracted from the wild type strain of S. typhimurium caused inflammation of greater magnitude compared with the OMPs extracted from its mutant construct as evident from the oedema test as well as the hyperalgesic (flicking) response of the animals under experimental conditions. However, Aloe vera applied topically, administered intraperitoneally or in combination modulated the inflammatory response. The maximum effect was observed with the combined formulation indicating modulation at local as well as systemic levels. The results reveal that this modulation could be due to the potential of Aloe vera to decrease peroxidative damage via a decrease in the levels of monokines (TNF‐α, IL‐1 and IL‐6) and an increase in the level of superoxide dismutase (SOD). Moreover, the presence of SOD in Aloe vera itself might be responsible for enhancing its levels in the macrophages. On the other hand, no significant change in the catalase activity was observed by Aloe vera treatment. The use of Aloe vera, therefore, seems to have a promising role in the modulation of Salmonella OmpR mediated inflammation. Copyright © 2008 John Wiley & Sons, Ltd.
RetractedDecreased FKBP12.6 expression and enhanced endothelin receptor signaling associated with arrhymogenesis in myocardial infarction rats
Authors: He Haibo , Shi Mengqiong , Zeng Xiaowei , Yang Xianzhe , Yang Jun , Wu Limao , Li Lianda 
Published: June 2008

AbstractScientific Deception: Retraction of a Fraudulent Paper

Andrew Coats
Elizabeth M. Williamson

We the editors of the International Journal of Cardiology and Phytotherapy Research regretfully report a case of scientific fraud. We have been made aware that two manuscripts published around the same time contain similar figures and tables. Upon further investigation the manuscript published in Phytotherapy Research 1 appears to have included falsely reproduced experiments with no acknowledgement of original source data and has consequently been retracted. The manuscript published in the International Journal of Cardiology 2 stands and there is no criticism of the authors of this paper.

1. He H, Shi M, Zeng X, Yang X, Yang J, Wu L, Li L.
Decreased FKBP12.6 expression and enhanced endothelin receptor signaling
associated with arrhymogenesis in myocardial infarction rats.
Phytother Res. 2008 Aug;22(8):1115‐24.
Doi: 10.1002/ptr.2470

2. Zhang Y, Huang ZJ, Dai DZ, Feng Y, Na T, Tang XY, Dai Y.
Downregulated FKBP12.6 expression and upregulated endothelin signaling contribute to elevated diastolic calcium and arrhythmogenesis in rat cardiomyopathy produced by l‐thyroxin. International Journal of Cardiology, [Epub ahead of print] Doi:10.1016/j.ijcard.2008.05.018
Pachypodol, a flavonol from the leaves of Calycopteris floribunda, inhibits the growth of CaCo 2 colon cancer cell line in vitro
Authors: Ali Husne‐Ara , Chowdhury A. K. Azad , Rahman Abul K. M. , Borkowski Tomasz , Nahar Lutfun , Sarker Satyajit D. 
Published: June 2008

AbstractCalycopteris floribunda Lam., commonly known as ‘goichia lata or goache lata’, is a large climbing woody shrub from Bangladesh, and well distributed in a number of other south‐east Asian countries. Traditionally, C. floribunda has been used in colic, as an antihelminthic, astringent and carminative, and for the treatment of diarrhoea, dysentery, jaundice and malaria in many countries including Bangladesh. Pachypodol (5,4′‐dihydroxy‐3,7,3′‐trimethoxyflavone) has been isolated from the leaves of C. floribunda by repeated column chromatography on silica gel, and the structure confirmed by spectroscopic means. While the general toxicity of pachypodol was determined by the brine shrimp lethality assay, the cytotoxic potential of this flavonoid has been evaluated by the Promega's CellTiter 96 Non‐Radioactive Cell Proliferation Assay using the CaCo‐2 colon cancer cell line (IC50 = 185.6 µM). A summary of the biological activities of pachypodol reported to date is also presented. Copyright © 2008 John Wiley & Sons, Ltd.
Combined 13C NMR and DFT/GIAO studies of the polyketides Aurasperone A and Fonsecinone A
Authors: de Lazaro Sergio , Campos Francinete Ramos , Rodrigues‐Fo Edson , Barison Andersson , Daolio Cristina , Ferreira Antonio G. , Polo Victor , Longo Elson , Andrés Juan 
Published: June 2008

AbstractStructural characterization by NMR spectroscopy and DFT calculations was performed for two dimeric naphtho‐γ‐pyrones, the polyketides Aurasperone A and Fonsecinone A. Experimental data (13C NMR chemical shifts and interatomic geometries) were found to be in reasonable agreement with theoretical ones, obtained at B3LYP level for three different basis sets (6‐31G/6‐31G(d)/6‐31G(d,p)). Additionally, the dipolar moments calculation allowed explaining the different solubility for these molecules. The 13C NMR theoretical chemical shifts were calculated with the GIAO method and the solvent effects were taken into account by means of the PCM approximation. In this work, the DFT/GIAO methodology shows to be a reliable tool in the assignment of experimental NMR chemical shifts of similar molecules. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008