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  • Open Access

    ARTICLE

    Isolation and Characterization of Fast-Migrating Human Glioma Cells in the Progression of Malignant Gliomas

    Vivian Adamski*, Anne Dorothée Schmitt*, Charlotte Flüh*, Michael Synowitz*, Kirsten Hattermann†1, Janka Held-Feindt*1

    Oncology Research, Vol.25, No.3, pp. 341-353, 2017, DOI:10.3727/096504016X14737243054982

    Abstract Gliomas are the most common primary brain tumors. The most malignant form, the glioblastoma multiforme (GBM; WHO IV), is characterized by an invasive phenotype, which enables the tumor cells to infiltrate into adjacent brain tissue. When investigating GBM migration and invasion properties in vitro, in most cases GBM cell lines were analyzed. Comprehensive investigations focusing on progression-dependent characteristics of migration processes using fresh human glioma samples of different malignancy grades do not exist. Thus, we isolated fast-migrating tumor cells from fresh human glioma samples of different malignancy grades (astrocytomas WHO grade II, grade III, GBM,… More >

  • Open Access

    ARTICLE

    Generation and characterization of a population of Tagetes minuta of broad genetic base - Obtaining selected individuals

    Massuh Y1,2, LE Torres1, SF Ocaño1, P Bruentti1, AG Chaves1, JA Zygadlo2, MS Ojeda1

    Phyton-International Journal of Experimental Botany, Vol.86, pp. 214-223, 2017, DOI:10.32604/phyton.2017.86.214

    Abstract Tagetes minuta L. (Asteraceae) is an annual herb that is of great interest due to the bioactive properties of its essential oil (EO) and its industrial use. In Argentina, 0.5 tons/year of EO are obtained from wild populations and commercialized with a value of 80-120 US$/kg. The introduction of the species in culture, and the initiation of a process of domestication, selection and breeding material aimed at generating higher yields and quality of EO as an alternative to wild collection. The goal of this work was to generate a population with a broad genetic base to… More >

  • Open Access

    ARTICLE

    Preparation and Characterization of the Nanocomposites from Chemically Modified Nanocellulose and Poly(lactic acid)

    Liqing Wei1, Shupin Luo2, Armando G. McDonald2, Umesh P. Agarwal1, Kolby C. Hirth1, Laurent M. Matuana3, Ronald C. Sabo1* , Nicole M. Stark1*

    Journal of Renewable Materials, Vol.5, No.5, pp. 410-422, 2017, DOI:10.7569/JRM.2017.634144

    Abstract Cellulose nanocrystals (CNCs) are renewable and sustainable filler for polymeric nanocomposites. However, their high hydrophilicity limits their use with hydrophobic polymer for composite materials. In this study, freeze-dried CNCs were modified by transesterification with canola oil fatty acid methyl ester to reduce the hydrophilicity. The transesterified CNCs (CNCFE) were compounded with PLA into nanocomposites. CNCFE with long-chain hydrocarbons plays a role as plasticizer. Increasing CNCFE loadings resulted in clear plasticizing effects. Lower Tg and Tm were achieved for CNCFE-based nanocomposites. Plasticizing nanocomposite melt with CNCFE can mitigate the degradation of CNCs during thermal processing. The More >

  • Open Access

    ARTICLE

    Physico-Chemical and Morphological Characterization of Cellulosic Samples Obtained from Sisal Fibers

    G. Mondragon, C. Peña-Rodriguez, A. Eceiza, A. Arbelaiz*

    Journal of Renewable Materials, Vol.5, No.5, pp. 345-356, 2017, DOI:10.7569/JRM.2017.634124

    Abstract In this work, the main chemical reactions conditions of a succession of specific chemical treatments used for the isolation of nanocellulose from sisal fibers were evaluated. The novelty of this work is the study done to analyze the effect of different reaction conditions (time or concentration) in fiber structure and composition as well as in the characteristics of obtained cellulosic samples. In order to achieve this goal different physicochemical, thermal and morphological characterization techniques were used after each chemical treatment and the most suitable reaction conditions were selected for the subsequent treatment. Moreover, the thermal More >

  • Open Access

    ARTICLE

    Synthesis and Characterization of Nanocrystalline Cellulose Derived from Pineapple Peel Residues

    Melissa Camacho1, Yendry Regina Corrales Ureña*,1, Mary Lopretti2, Leonel Bustamante Carballo1, Galia Moreno1, Brian Alfaro1, Jose Roberto Vega Baudrit1,3

    Journal of Renewable Materials, Vol.5, No.5, pp. 271-279, 2017, DOI:10.7569/JRM.2017.634117

    Abstract Pineapple peel biomass was used as raw material for nanocellulose extraction. The raw material is a residue from the Costa Rican fruit industry. The nanocellulose was obtained by a two-step hydrolysis process. Firstly, the cellulose was hydrolyzed with HCl to obtain microcrystalline cellulose. In the second step, the hydrolysis was carried out using H2SO4 to obtain smaller fragments and decrease the lignin content. A timedependent study was carried out to determine the particle size decrease depending on the contact time with the H2SO4. The chemical, thermal and morphological properties were analyzed by Fourier transform infrared More >

  • Open Access

    ARTICLE

    Design and Characterization of Biocomposites from Poly(lactic acid) (PLA) and Buriti Petiole (Mauritia flexuosa)

    Samantha Andrade Vale de Sousa1, Mercês Coelho da Silva2, Orlando Gama da Silva Júnior3, Artur Caron Mottin4, Rodrigo Lambert Oréfice3, Eliane Ayres1*

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 251-257, 2017, DOI:10.7569/JRM.2017.634115

    Abstract Buriti or miriti (Mauritia flexuosa) is a palm tree found in the Brazilian cerrado. Herein buriti petiole, part of the trunk that supports the leaves, was ground and used without any treatment as low density load to prepare poly(lactic acid) biocomposites. X-ray microtomography of buriti petiole showed its porous structure, with a wide pore size distribution determined with the aid of SEM. The obtained biocomposites with 1, 5 and 10 wt% of buriti petiole particles were investigated by their sessile drop contact angle, FTIR, TGA and tensile test. The tensile properties indicated poor adhesion between More >

  • Open Access

    ARTICLE

    Synthesis and Characterization of Interpenetrating Polymer Networks (IPNs) from Acrylated Soybean Oil a-Resorcylic Acid: Part 2. Thermo-Mechanical Properties and Linear Fracture Mechanics

    Bernal Sibaja1,2,3, Camila Pereira Matheus1,2, Ricardo Ballestero Mendez1,2,Ramsis Farag1,2,4, J. R. Vega-Baudrit3, Maria L. Auad*,1,2

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 241-250, 2017, DOI:10.7569/JRM.2017.634114

    Abstract The thermo-mechanical properties and linear fracture mechanics of acrylated soybean oil and the triglycidylated ether of α-resorcylic acid interpenetrated networks as a function of their weight composition are the focus of Part 2 of this article. Thermo-mechanical characterization showed that the obtained materials behave as thermoset amorphous polymers, and that both the modulus and glass transition are extremely dependent on the epoxy/acrylate weight ratio. Modulus values ranged from 0.7 to 3.3 GPa at 30 °C, and glass transition temperatures ranged from around 58 °C to approx. 130 °C. No synergistic effect on these two properties More >

  • Open Access

    ARTICLE

    Synthesis and Characterization of Interpenetrating Polymer Networks (IPNs) from Acrylated Soybean Oil and a-Resorcylic Acid: Part 1. Kinetics of Network Formation

    Bernal Sibaja1,2,3, Camila Pereira Matheus1,2, Ricardo Ballestero Mendez1,2, J. R. Vega-Baudrit3, Maria L. Auad*,1,2

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 231-240, 2017, DOI:10.7569/JRM.2017.634113

    Abstract Interpenetrating polymer networks (IPNs) using an epoxy phase synthesized from chemically modified α-resorcylic acid, and an acrylate phase employing acrylated soybean oil are the main focus of this study. Part 1 details the epoxidation of α-resorcylic acid with epichlorohydrin in alkaline medium, as well as the study of the polymerization and network formation of the generated epoxy-acrylate interpenetrated systems. The epoxy content of the epoxidized α-resorcylic acid was measured by means of a titration using HBr in acetic acid solution, and the functionalization was studied by FTIR. From the obtained results, mainly calorimetry and gel More >

  • Open Access

    ARTICLE

    Thermal-Mechanical Characterization of Polyurethane Rigid Foams: Effect of Modifying Bio-Polyol Content in Isocyanate Prepolymers

    Luis Daniel Mora-Murillo1, Felipe Orozco-Gutierrez2, José Vega-Baudrit2, Rodolfo Jesús González-Paz2*

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 220-230, 2017, DOI:10.7569/JRM.2017.634112

    Abstract Nowadays, green polyurethane (PU) foams are mostly synthesized by replacing an amount of petrochemical polyol with biobased polyol. Here we report five different families of isocyanate prepolymer formulations that were prepared with biobased sources and the correlation between the structure of chains and the properties of the produced PU foam. Foam behavior in tension, torsion, compression, shape memory tests and physical properties were studied by dynamic mechanical thermal analysis (DMTA); interactions in the polymer chains were analyzed by Fourier transform infrared spectroscopy (FTIR); and thermal analysis was performed by thermogravimetry (TGA) and differential scanning calorimetry More >

  • Open Access

    ARTICLE

    Renewable Polymers: Synthesis and Characterization of Poly(4-ketopimelic acid-glycerol)

    Ananda S. Amarasekara*, Muhammad A. Hasan, Eve Larkin

    Journal of Renewable Materials, Vol.5, No.1, pp. 62-66, 2017, DOI:10.7569/JRM.2016.634129

    Abstract Condensation polymerization of renewable resources-based monomers, 4-ketopimelic acid and glycerol, were studied using two different catalysts; p-toluenesulfonic acid and Sb2O3. The highest polymer yield of 96% was achieved by using a 3:4 mole ratio mixture of 4-ketopimelic acid and glycerol, with Sb2O3 (0.5 mol% relative to 4-ketopimelic acid) as catalyst and heating at 23–210 °C, under N2 for 1 h; then 210 °C, vacuum, 12 h. The poly(4-ketopimelic acid-glycerol) formed is insoluble in all common organic solvents and is shown to contain a branched polymeric structure with ketal and ester links by using FT-IR, 1H More >

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