242 research outputs found

    Use of wet-laid techniques to form flax-polypropylene nonwovens as base substrates for eco-friendly composites by using hot-press molding

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    The wet-laid process with flax (base) and polypropylene (binder) fibers has been used to obtain nonwovens for further processing by hot-press molding. Mechanical characterization of nonwovens has revealed that slight anisotropy is obtained with the wet-laid process as better tensile strength is obtained in the preferential deposition direction. The thermo-bonding process provides good cohesion to nonwovens, which is critical for further handling/shaping by hot-press molding. Flax:PP composites have been processed by stacking eight individual flax:PP nonwoven sheets and applying moderate temperature and pressure. As the amount of binder fiber is relatively low (< 30 wt%) if compared with similar systems processed by extrusion and injection molding, it is possible to obtain eco-friendly composites as the total content on natural fiber (flax) is higher than 70 wt%. Mechanical characterization of hot-pressed flax:PP composites has revealed high dependency of tensile and flexural strength on the total amount of binder fiber as this component is responsible for flax fiber embedment which is a critical parameter to ensure good fibermatrix interaction. Combination of wet-laid techniques with hot-press molding processes is interesting from both technical and environmental points of view as high natural fiber content composites with balanced properties can be obtained. POLYM. COMPOS., 2012. (c) 2011 Society of Plastics EngineersThis work is part of the project IPT-310000-2010-037, "ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character" funded by the "Ministerio de Ciencia e Innovacion," with an aid of 189540.20 euros, within the "Plan Nacional de InvestigacionCientifica, Desarrollo e InnovacionTecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, Operational Programme on R+D+i for and on behalf of the companies." It is also acknowledged the project "WET-TEX: Implementacion de la tecnologia wet-laid en el desarrollo de nuevos textiles medico-sanitario" with expedient number IMIDIC/2010/137 (total aid of 284400 euro), and the project "WET-TEX II: Implementacion de la tecnologia wet-laid en la investigacion y desarrollo de paneles para aplicaciones tecnicas a partir de residuos procedentes de la industria textil." with expedient number IMDEEA/2011/167 (total aid of 255000 euro) funded by IMPIVA and cofunded (80%) by the European Union through FEDER funds, Valencian Community Operational 2007-2012.Fages, E.; Gironés Bernabé, S.; Sánchez Nacher, L.; García Sanoguera, D.; Balart Gimeno, RA. (2012). Use of wet-laid techniques to form flax-polypropylene nonwovens as base substrates for eco-friendly composites by using hot-press molding. Polymer Composites. 33(2):253-261. doi:10.1002/pc.22147S253261332Hargitai, H., Rácz, I., & Anandjiwala, R. D. (2008). 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Journal of Cleaner Production, 18(4), 313-327. doi:10.1016/j.jclepro.2009.10.022Mohanty, A. K., Misra, M., & Drzal, L. T. (2002). Journal of Polymers and the Environment, 10(1/2), 19-26. doi:10.1023/a:1021013921916Larsson-Brelid, P., Wålinder, M. E. P., Westin, M., & Rowell, R. (2008). Ecobuild a Center for Development of Fully Biobased Material Systems and Furniture Applications. Molecular Crystals and Liquid Crystals, 484(1), 257/[623]-264/[630]. doi:10.1080/15421400801904666MacDougall, C. (2008). Natural Building Materials in Mainstream Construction: Lessons from the U. K. Journal of Green Building, 3(3), 1-14. doi:10.3992/jgb.3.3.1El-Sabbagh, A., Steuernagel, L., & Ziegmann, G. (2009). Processing and modeling of the mechanical behavior of natural fiber thermoplastic composite: Flax/polypropylene. Polymer Composites, 30(4), 510-519. doi:10.1002/pc.20675Aurich, T., & Mennig, G. (2001). Flow-induced fiber orientation in injection molded fit fiber reinforced polypropylene. Polymer Composites, 22(5), 680-689. doi:10.1002/pc.10570Andersons, J., Spārniņš, E., & Joffe, R. (2006). Stiffness and strength of flax fiber/polymer matrix composites. Polymer Composites, 27(2), 221-229. doi:10.1002/pc.20184Saiah, R., Sreekumar, P. A., Gopalakrishnan, P., Leblanc, N., Gattin, R., & Saiter, J. M. (2009). Fabrication and characterization of 100% green composite: Thermoplastic based on wheat flour reinforced by flax fibers. Polymer Composites, 30(11), 1595-1600. doi:10.1002/pc.20732Siaotong, B. A. C., Tabil, L. G., Panigrahi, S. A., & Crerar, W. J. (2010). Extrusion Compounding of Flax-Fiber-Reinforced Polyethylene Composites: Effects of Fiber Content and Extrusion Parameters. Journal of Natural Fibers, 7(4), 289-306. doi:10.1080/15440478.2010.527680Twite-Kabamba, E., Mechraoui, A., & Rodrigue, D. (2009). Rheological properties of polypropylene/hemp fiber composites. Polymer Composites, 30(10), 1401-1407. doi:10.1002/pc.20704S.R. Wang T.H. Yan J.H. Jiang N.L. Chen Proceedings of the 2009 International Textile Science and Technology Forum 2010H. Hargitai I. Racz R. Anandjiwala Development of HEMP Fiber Reinforced Polypropylene Composites 2007Chen, J. Y., Müller, D. H., König, C., Nießen, K., & Müssig, J. (2010). Spunlaced Flax/Polypropylene Nonwoven as Auto Interior Material: Acoustical and Fogging Performance. Journal of Biobased Materials and Bioenergy, 4(4), 330-337. doi:10.1166/jbmb.2010.1097Yan Chen, Müller, D. H., Nießen, K., & Müssig, J. (2008). Spunlaced Flax/Polypropylene Nonwoven as Auto Interior Material: Mechanical Performance. Journal of Industrial Textiles, 38(1), 69-86. doi:10.1177/1528083707087832JOLLY, M., & JAYARAMAN, K. (2006). MANUFACTURING FLAX FIBRE-REINFORCED POLYPROPYLENE COMPOSITES BY HOT-PRESSING. International Journal of Modern Physics B, 20(25n27), 4601-4606. doi:10.1142/s0217979206041756Niu, H., Jiao, X., Wang, R., & Zhou, H. (2010). 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    The Inhibitor of Growth Protein 5 (ING5) Depends on INCA1 as a Co-Factor for Its Antiproliferative Effects

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    The proteins of the Inhibitor of Growth (ING) family are involved in multiple cellular functions such as cell cycle regulation, apoptosis, and chromatin remodeling. For ING5, its actual role in growth suppression and the necessary partners are not known. In a yeast-two-hybrid approach with human bone marrow derived cDNA, we identified ING5 as well as several other proteins as interaction partners of Inhibitor of cyclin A1 (INCA1) that we previously characterized as a novel interaction partner of cyclin A1/CDK2. ING5 expression in leukemic AML blasts was severely reduced compared to normal bone marrow. In line, ING5 inhibited bone marrow colony formation upon retroviral transduction. However, Inca1−/− bone marrow colony formation was not suppressed by ING5. In murine embryonic fibroblast (MEF) cells from Inca1+/+ and Inca1−/− mice, overexpression of ING5 suppressed cell proliferation only in the presence of INCA1, while ING5 had no effect in Inca1−/− MEFs. ING5 overexpression induced a delay in S-phase progression, which required INCA1. Finally, ING5 overexpression enhanced Fas-induced apoptosis in Inca1+/+ MEFs, while Inca1−/− MEFs were protected from Fas antibody-induced apoptosis. Taken together, these results indicate that ING5 is a growth suppressor with suppressed expression in AML whose functions depend on its interaction with INCA1

    Dengue Virus Capsid Protein Binds Core Histones and Inhibits Nucleosome Formation in Human Liver Cells

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    Dengue virus (DENV) is a member of the Flaviviridae and a globally (re)emerging pathogen that causes serious human disease. There is no specific antiviral or vaccine for dengue virus infection. Flavivirus capsid (C) is a structural protein responsible for gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. Flaviviral replication is known to occur in the cytoplasm yet a large portion of capsid protein localizes to the nucleus during infection. The reasons for the nuclear presences of capsid are not completely understood. Here, we expressed mature DENV C in a tandem affinity purification assay to identify potential binding partners in human liver cells. DENV C targeted the four core histones, H2A, H2B, H3 and H4. DENV C bound recombinant histones in solution and colocalized with histones in the nucleus and cytoplasm of liver cells during DENV infection. We show that DENV C acts as a histone mimic, forming heterodimers with core histones, binding DNA and disrupting nucleosome formation. We also demonstrate that DENV infection increases the amounts of core histones in livers cells, which may be a cellular response to C binding away the histone proteins. Infection with DENV additionally alters levels of H2A phosphorylation in a time-dependent manner. The interactions of C and histones add an interesting new role for the presence of C in the nucleus during DENV infection

    Genome-based trait prediction in multi- environment breeding trials in groundnut

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    Genomic selection (GS) can be an efficient and cost-effective breeding approach which captures both small- and large-effect genetic factors and therefore promises to achieve higher genetic gains for complex traits such as yield and oil content in groundnut. A training population was constituted with 340 elite lines followed by genotyping with 58 K ‘Axiom_Arachis’ SNP array and phenotyping for key agronomic traits at three locations in India. Four GS models were tested using three different random cross-validation schemes (CV0, CV1 and CV2). These models are: (1) model 1 (M1 = E + L) which includes the main effects of environment (E) and line (L); (2) model 2 (M2 = E + L + G) which includes the main effects of markers (G) in addition to E and L; (3) model 3 (M3 = E + L + G + GE), a naïve interaction model; and (4) model 4 (E + L + G + LE + GE), a naïve and informed interaction model. Prediction accuracy estimated for four models indicated clear advantage of the inclusion of marker information which was reflected in better prediction accuracy achieved with models M2, M3 and M4 as compared to M1 model. High prediction accuracies (> 0.600) were observed for days to 50% flowering, days to maturity, hundred seed weight, oleic acid, rust@90 days, rust@105 days and late leaf spot@90 days, while medium prediction accuracies (0.400–0.600) were obtained for pods/plant, shelling %, and total yield/plant. Assessment of comparative prediction accuracy for different GS models to perform selection for untested genotypes, and unobserved and unevaluated environments provided greater insights on potential application of GS breeding in groundnut

    Nuclear ING2 expression is reduced in human cutaneous melanomas

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    Cutaneous malignant melanoma is a severe and sometimes life-threatening cancer. The molecular mechanism of melanomagenesis is incompletely understood. Deregulation of apoptosis is probably one of the key factors contributing to the progression of melanoma. The inhibitor of growth (ING) family proteins are candidate tumour suppressors which play important roles in apoptosis. Downregulated expression of ING proteins have been reported in several tumour types, including the loss of nuclear expression of p33ING1b in melanoma. As ING2 exhibits 58.9% homology with p33ING1b, we hypothesized that the aberrant expression of ING2 may be involved in melanomagenesis. Here, we used tissue microarray technology and immunohistochemistry to examine ING2 expression in human nevi and melanoma biopsies. Our data showed that nuclear ING2 expression was significantly reduced in radial growth phase (RGP), vertical growth phase (VGP), and metastatic melanomas compared with dysplastic nevi (P<0.05). Our data also revealed that nuclear ING2 expression was not associated with patient's gender, age or tumour thickness, ulceration, American Joint Committee on Cancer (AJCC) stage, tumour subtype, location and 5-year survival (P>0.05). Taken together, our results suggest that nuclear ING2 expression is significantly reduced in human melanomas and that reduced ING2 may be an important molecular event in the initiation of melanoma development

    H3K9me2/3 Binding of the MBT Domain Protein LIN-61 Is Essential for Caenorhabditis elegans Vulva Development

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    MBT domain proteins are involved in developmental processes and tumorigenesis. In vitro binding and mutagenesis studies have shown that individual MBT domains within clustered MBT repeat regions bind mono- and dimethylated histone lysine residues with little to no sequence specificity but discriminate against the tri- and unmethylated states. However, the exact function of promiscuous histone methyl-lysine binding in the biology of MBT domain proteins has not been elucidated. Here, we show that the Caenorhabditis elegans four MBT domain protein LIN-61, in contrast to other MBT repeat factors, specifically interacts with histone H3 when methylated on lysine 9, displaying a strong preference for di- and trimethylated states (H3K9me2/3). Although the fourth MBT repeat is implicated in this interaction, H3K9me2/3 binding minimally requires MBT repeats two to four. Further, mutagenesis of residues conserved with other methyl-lysine binding MBT regions in the fourth MBT repeat does not abolish interaction, implicating a distinct binding mode. In vivo, H3K9me2/3 interaction of LIN-61 is required for C. elegans vulva development within the synMuvB pathway. Mutant LIN-61 proteins deficient in H3K9me2/3 binding fail to rescue lin-61 synMuvB function. Also, previously identified point mutant synMuvB alleles are deficient in H3K9me2/3 interaction although these target residues that are outside of the fourth MBT repeat. Interestingly, lin-61 genetically interacts with two other synMuvB genes, hpl-2, an HP1 homologous H3K9me2/3 binding factor, and met-2, a SETDB1 homologous H3K9 methyl transferase (H3K9MT), in determining C. elegans vulva development and fertility. Besides identifying the first sequence specific and di-/trimethylation binding MBT domain protein, our studies imply complex multi-domain regulation of ligand interaction of MBT domains. Our results also introduce a mechanistic link between LIN-61 function and biology, and they establish interplay of the H3K9me2/3 binding proteins, LIN-61 and HPL-2, as well as the H3K9MT MET-2 in distinct developmental pathways

    Identification of Combinatorial Patterns of Post-Translational Modifications on Individual Histones in the Mouse Brain

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    Post-translational modifications (PTMs) of proteins are biochemical processes required for cellular functions and signalling that occur in every sub-cellular compartment. Multiple protein PTMs exist, and are established by specific enzymes that can act in basal conditions and upon cellular activity. In the nucleus, histone proteins are subjected to numerous PTMs that together form a histone code that contributes to regulate transcriptional activity and gene expression. Despite their importance however, histone PTMs have remained poorly characterised in most tissues, in particular the brain where they are thought to be required for complex functions such as learning and memory formation. Here, we report the comprehensive identification of histone PTMs, of their combinatorial patterns, and of the rules that govern these patterns in the adult mouse brain. Based on liquid chromatography, electron transfer, and collision-induced dissociation mass spectrometry, we generated a dataset containing a total of 10,646 peptides from H1, H2A, H2B, H3, H4, and variants in the adult brain. 1475 of these peptides carried one or more PTMs, including 141 unique sites and a total of 58 novel sites not described before. We observed that these PTMs are not only classical modifications such as serine/threonine (Ser/Thr) phosphorylation, lysine (Lys) acetylation, and Lys/arginine (Arg) methylation, but also include several atypical modifications such as Ser/Thr acetylation, and Lys butyrylation, crotonylation, and propionylation. Using synthetic peptides, we validated the presence of these atypical novel PTMs in the mouse brain. The application of data-mining algorithms further revealed that histone PTMs occur in specific combinations with different ratios. Overall, the present data newly identify a specific histone code in the mouse brain and reveal its level of complexity, suggesting its potential relevance for higher-order brain functions
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