Sample records for bacterial polyester inclusions

  1. Bacterial polyesters: biosynthesis, biodegradable plastics and biotechnology.

    PubMed

    Lenz, Robert W; Marchessault, Robert H

    2005-01-01

    The discovery and chemical identification, in the 1920s, of the aliphatic polyester: poly(3-hydroxybutyrate), PHB, as a granular component in bacterial cells proceeded without any of the controversies which marked the recognition of macromolecules by Staudinger. Some thirty years after its discovery, PHB was recognized as the prototypical biodegradable thermoplastic to solve the waste disposal challenge. The development effort led by Imperial Chemical Industries Ltd., encouraged interdisciplinary research from genetic engineering and biotechnology to the study of enzymes involved in biosynthesis and biodegradation. From the simple PHB homopolyester discovered by Maurice Lemoigne in the mid-twenties, a family of over 100 different aliphatic polyesters of the same general structure has been discovered. Depending on bacterial species and substrates, these high molecular weight stereoregular polyesters have emerged as a new family of natural polymers ranking with nucleic acids, polyamides, polyisoprenoids, polyphenols, polyphosphates, and polysaccharides. In this historical review, the chemical, biochemical and microbial highlights are linked to personalities and locations involved with the events covering a discovery timespan of 75 years.

  2. Bacterial polyester inclusions engineered to display vaccine candidate antigens for use as a novel class of safe and efficient vaccine delivery agents.

    PubMed

    Parlane, Natalie A; Wedlock, D Neil; Buddle, Bryce M; Rehm, Bernd H A

    2009-12-01

    Bioengineered bacterial polyester inclusions have the potential to be used as a vaccine delivery system. The biopolyester beads were engineered to display a fusion protein of the polyester synthase PhaC and the two key antigens involved in immune response to the infectious agent that causes tuberculosis, Mycobacterium tuberculosis, notably antigen 85A (Ag85A) and the 6-kDa early secreted antigenic target (ESAT-6) from Mycobacterium tuberculosis. Polyester beads displaying the respective fusion protein at a high density were successfully produced (henceforth called Ag85A-ESAT-6 beads) by recombinant Escherichia coli. The ability of the Ag85A-ESAT-6 beads to enhance mouse immunity to the displayed antigens was investigated. The beads were not toxic to the animals, as determined by weight gain and absence of lesions at the inoculation site in immunized animals. In vivo injection of the Ag85A-ESAT-6 beads in mice induced significant humoral and cell-mediated immune responses to both Ag85A and ESAT-6. Vaccination with Ag85A-ESAT-6 beads was efficient at stimulating immunity on their own, and this ability was enhanced by administration of the beads in an oil-in-water emulsion. In addition, vaccination with the Ag85A-ESAT-6 beads induced significantly stronger humoral and cell-mediated immune responses than vaccination with an equivalent dose of the fusion protein Ag85A-ESAT-6 alone. The immune response induced by the beads was of a mixed Th1/Th2 nature, as assessed from the induction of the cytokine gamma interferon (Th1 immune response) and increased levels of immunoglobulin G1 (Th2 immune response). Hence, engineered biopolyester beads displaying foreign antigens represent a new class of versatile, safe, and biocompatible vaccines.

  3. Polyesters from microorganisms.

    PubMed

    Kim, Y B; Lenz, R W

    2001-01-01

    Bacterial polyesters have been found to have useful properties for applications as thermoplastics, elastomers, and adhesives and are biodegradable and biocompatible. Poly(3-hydroxyalkanoates) (PHAs) and poly(beta-malate) are the most representative polyesters synthesized by microorganisms. PHAs containing a wide variety of repeating units can be produced by bacteria, including those containing many types of pendant functional groups which can be synthesized by microorganisms that are grown on unnatural organic substrates. Poly(beta-malate) is of interest primarily for medical applications, especially for drug delivery systems. In this chapter, the bacterial production and properties of poly(3-hydroxyalkanoates) and poly(beta-malate) are described with emphasis on the former.

  4. Polyester synthases: natural catalysts for plastics.

    PubMed Central

    Rehm, Bernd H A

    2003-01-01

    Polyhydroxyalkanoates (PHAs) are biopolyesters composed of hydroxy fatty acids, which represent a complex class of storage polyesters. They are synthesized by a wide range of different Gram-positive and Gram-negative bacteria, as well as by some Archaea, and are deposited as insoluble cytoplasmic inclusions. Polyester synthases are the key enzymes of polyester biosynthesis and catalyse the conversion of (R)-hydroxyacyl-CoA thioesters to polyesters with the concomitant release of CoA. These soluble enzymes turn into amphipathic enzymes upon covalent catalysis of polyester-chain formation. A self-assembly process is initiated resulting in the formation of insoluble cytoplasmic inclusions with a phospholipid monolayer and covalently attached polyester synthases at the surface. Surface-attached polyester synthases show a marked increase in enzyme activity. These polyester synthases have only recently been biochemically characterized. An overview of these recent findings is provided. At present, 59 polyester synthase structural genes from 45 different bacteria have been cloned and the nucleotide sequences have been obtained. The multiple alignment of the primary structures of these polyester synthases show an overall identity of 8-96% with only eight strictly conserved amino acid residues. Polyester synthases can been assigned to four classes based on their substrate specificity and subunit composition. The current knowledge on the organization of the polyester synthase genes, and other genes encoding proteins related to PHA metabolism, is compiled. In addition, the primary structures of the 59 PHA synthases are aligned and analysed with respect to highly conserved amino acids, and biochemical features of polyester synthases are described. The proposed catalytic mechanism based on similarities to alpha/beta-hydrolases and mutational analysis is discussed. Different threading algorithms suggest that polyester synthases belong to the alpha/beta-hydrolase superfamily, with

  5. Isolation of cell-free bacterial inclusion bodies.

    PubMed

    Rodríguez-Carmona, Escarlata; Cano-Garrido, Olivia; Seras-Franzoso, Joaquin; Villaverde, Antonio; García-Fruitós, Elena

    2010-09-17

    Bacterial inclusion bodies are submicron protein clusters usually found in recombinant bacteria that have been traditionally considered as undesirable products from protein production processes. However, being fully biocompatible, they have been recently characterized as nanoparticulate inert materials useful as scaffolds for tissue engineering, with potentially wider applicability in biomedicine and material sciences. Current protocols for inclusion body isolation from Escherichia coli usually offer between 95 to 99% of protein recovery, what in practical terms, might imply extensive bacterial cell contamination, not compatible with the use of inclusion bodies in biological interfaces. Using an appropriate combination of chemical and mechanical cell disruption methods we have established a convenient procedure for the recovery of bacterial inclusion bodies with undetectable levels of viable cell contamination, below 10⁻¹ cfu/ml, keeping the particulate organization of these aggregates regarding size and protein folding features. The application of the developed protocol allows obtaining bacterial free inclusion bodies suitable for use in mammalian cell cultures and other biological interfaces.

  6. Towards revealing the structure of bacterial inclusion bodies.

    PubMed

    Wang, Lei

    2009-01-01

    Protein aggregation is a widely observed phenomenon in human diseases, biopharmaceutical production, and biological research. Protein aggregates are generally classified as highly ordered, such as amyloid fibrils, or amorphous, such as bacterial inclusion bodies. Amyloid fibrils are elongated filaments with diameters of 6-12 nm, they are comprised of residue-specific cross-beta structure, and display characteristic properties, such as binding with amyloid-specific dyes. Amyloid fibrils are associated with dozens of human pathological conditions, including Alzheimer disease and prion diseases. Distinguished from amyloid fibrils, bacterial inclusion bodies display apparent amorphous morphology. Inclusion bodies are formed during high-level recombinant protein production, and formation of inclusion bodies is a major concern in biotechnology. Despite of the distinctive morphological difference, bacterial inclusion bodies have been found to have some amyloid-like properties, suggesting that they might contain structures similar to amyloid-like fibrils. Recent structural data further support this hypothesis, and this review summarizes the latest progress towards revealing the structural details of bacterial inclusion bodies.

  7. Bioengineering of Bacteria To Assemble Custom-Made Polyester Affinity Resins

    PubMed Central

    Hay, Iain D.; Du, Jinping; Burr, Natalie

    2014-01-01

    Proof of concept for the in vivo bacterial production of a polyester resin displaying various customizable affinity protein binding domains is provided. This was achieved by engineering various protein binding domains into a bacterial polyester-synthesizing enzyme. Affinity binding domains based on various structural folds and derived from molecular libraries were used to demonstrate the potential of this technique. Designed ankyrin repeat proteins (DARPins), engineered OB-fold domains (OBodies), and VHH domains from camelid antibodies (nanobodies) were employed. The respective resins were produced in a single bacterial fermentation step, and a simple purification protocol was developed. Purified resins were suitable for most lab-scale affinity chromatography purposes. All of the affinity domains tested produced polyester beads with specific affinity for the target protein. The binding capacity of these affinity resins ranged from 90 to 600 nmol of protein per wet gram of polyester affinity resin, enabling purification of a recombinant protein target from a complex bacterial cell lysate up to a purity level of 96% in one step. The polyester resin was efficiently produced by conventional lab-scale shake flask fermentation, resulting in bacteria accumulating up to 55% of their cellular dry weight as polyester. A further proof of concept demonstrating the practicality of this technique was obtained through the intracellular coproduction of a specific affinity resin and its target. This enables in vivo binding and purification of the coproduced “target protein.” Overall, this study provides evidence for the use of molecular engineering of polyester synthases toward the microbial production of specific bioseparation resins implementing previously selected binding domains. PMID:25344238

  8. Towards revealing the structure of bacterial inclusion bodies

    PubMed Central

    2009-01-01

    Protein aggregation is a widely observed phenomenon in human diseases, biopharmaceutical production, and biological research. Protein aggregates are generally classified as highly ordered, such as amyloid fibrils, or amorphous, such as bacterial inclusion bodies. Amyloid fibrils are elongated filaments with diameters of 6–12 nm, they are comprised of residue-specific cross-β structure, and display characteristic properties, such as binding with amyloid-specific dyes. Amyloid fibrils are associated with dozens of human pathological conditions, including Alzheimer disease and prion diseases. Distinguished from amyloid fibrils, bacterial inclusion bodies display apparent amorphous morphology. Inclusion bodies are formed during high-level recombinant protein production, and formation of inclusion bodies is a major concern in biotechnology. Despite of the distinctive morphological difference, bacterial inclusion bodies have been found to have some amyloid-like properties, suggesting that they might contain structures similar to amyloid-like fibrils. Recent structural data further support this hypothesis, and this review summarizes the latest progress towards revealing the structural details of bacterial inclusion bodies. PMID:19806034

  9. Engineering the bacterial shapes for enhanced inclusion bodies accumulation.

    PubMed

    Jiang, Xiao-Ran; Wang, Huan; Shen, Rui; Chen, Guo-Qiang

    2015-05-01

    Many bacteria can accumulate inclusion bodies such as sulfur, polyphosphate, glycogen, proteins or polyhydroxyalkanoates. To exploit bacteria as factories for effective production of inclusion bodies, a larger intracellular space is needed for more inclusion body accumulation. In this study, polyhydroxybutyrate (PHB) was investigated as an inclusion bodies representative to be accumulated by Escherichia coli JM109SG. Various approaches were taken to increase the bacterial cell sizes including deletion on actin-like protein gene mreB, weak expression of mreB in mreB deletion mutant, and weak expression of mreB in mreB deletion mutant under inducible expression of SulA, the inhibitor of division ring protein FtsZ. All of the methods resulted in different levels of increases in bacterial sizes and PHB granules accumulation. Remarkably, an increase of over 100% PHB accumulation was observed in recombinant E. coli overexpressing mreB in an mreB deletion mutant under inducible expression of FtsZ inhibiting protein SulA. The molecular mechanism of enlarged bacterial size was found to be directly relate to weakened cytoskeleton which was the result of broken skeleton helix. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  10. Bacterial Inclusion Bodies: Discovering Their Better Half.

    PubMed

    Rinas, Ursula; Garcia-Fruitós, Elena; Corchero, José Luis; Vázquez, Esther; Seras-Franzoso, Joaquin; Villaverde, Antonio

    2017-09-01

    Bacterial inclusion bodies (IBs) are functional, non-toxic amyloids occurring in recombinant bacteria showing analogies with secretory granules of the mammalian endocrine system. The scientific interest in these mesoscale protein aggregates has been historically masked by their status as a hurdle in recombinant protein production. However, progressive understanding of how the cell handles the quality of recombinant polypeptides and the main features of their intriguing molecular organization has stimulated the interest in inclusion bodies and spurred their use in diverse technological fields. The engineering and tailoring of IBs as functional protein particles for materials science and biomedicine is a good example of how formerly undesired bacterial byproducts can be rediscovered as promising functional materials for a broad spectrum of applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Studies on bacterial inclusion bodies.

    PubMed

    de Groot, Natalia S; Espargaró, Alba; Morell, Montserrat; Ventura, Salvador

    2008-08-01

    The field of protein misfolding and aggregation has become an extremely active area of research in recent years. Of particular interest is the deposition of polypeptides into inclusion bodies inside bacterial cells. One reason for this interest is that protein aggregation constitutes a major bottleneck in protein production and restricts the spectrum of protein-based drugs available for commercialization. Additionally, prokaryotic cells could provide a simple yet powerful system for studying the formation and prevention of toxic aggregates, such as those responsible for a number of degenerative diseases. Here, we review recent work that has challenged our understanding of the structure and physiology of inclusion bodies and provided us with a new view of intracellular protein deposition, which has important implications in microbiology, biomedicine and biotechnology.

  12. 76 FR 38612 - Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839, A-583-833] Certain Polyester... sunset reviews of the antidumping duty orders on polyester staple fiber (PSF) from the Republic of Korea... polyesters measuring 3.3 decitex (3 denier, inclusive) or more in diameter. This merchandise is cut to...

  13. Bacterial Inclusion Bodies Contain Amyloid-Like Structure

    PubMed Central

    Wang, Lei; Maji, Samir K; Sawaya, Michael R; Eisenberg, David; Riek, Roland

    2008-01-01

    Protein aggregation is a process in which identical proteins self-associate into imperfectly ordered macroscopic entities. Such aggregates are generally classified as amorphous, lacking any long-range order, or highly ordered fibrils. Protein fibrils can be composed of native globular molecules, such as the hemoglobin molecules in sickle-cell fibrils, or can be reorganized β-sheet–rich aggregates, termed amyloid-like fibrils. Amyloid fibrils are associated with several pathological conditions in humans, including Alzheimer disease and diabetes type II. We studied the structure of bacterial inclusion bodies, which have been believed to belong to the amorphous class of aggregates. We demonstrate that all three in vivo-derived inclusion bodies studied are amyloid-like and comprised of amino-acid sequence-specific cross-β structure. These findings suggest that inclusion bodies are structured, that amyloid formation is an omnipresent process both in eukaryotes and prokaryotes, and that amino acid sequences evolve to avoid the amyloid conformation. PMID:18684013

  14. Learning about protein solubility from bacterial inclusion bodies

    PubMed Central

    Martínez-Alonso, Mónica; González-Montalbán, Nuria; García-Fruitós, Elena; Villaverde, Antonio

    2009-01-01

    The progressive solving of the conformation of aggregated proteins and the conceptual understanding of the biology of inclusion bodies in recombinant bacteria is providing exciting insights on protein folding and quality. Interestingly, newest data also show an unexpected functional and structural complexity of soluble recombinant protein species and picture the whole bacterial cell factory scenario as more intricate than formerly believed. PMID:19133126

  15. Protein aggregation as bacterial inclusion bodies is reversible.

    PubMed

    Carrió, M M; Villaverde, A

    2001-01-26

    Inclusion bodies are refractile, intracellular protein aggregates usually observed in bacteria upon targeted gene overexpression. Since their occurrence has a major economical impact in protein production bio-processes, in vitro refolding strategies are under continuous exploration. In this work, we prove spontaneous in vivo release of both beta-galactosidase and P22 tailspike polypeptides from inclusion bodies resulting in their almost complete disintegration and in the concomitant appearance of soluble, properly folded native proteins with full biological activity. Since, in particular, the tailspike protein exhibits an unusually slow and complex folding pathway involving deep interdigitation of beta-sheet structures, its in vivo refolding indicates that bacterial inclusion body proteins are not collapsed into an irreversible unfolded state. Then, inclusion bodies can be observed as transient deposits of folding-prone polypeptides, resulting from an unbalanced equilibrium between in vivo protein precipitation and refolding that can be actively displaced by arresting protein synthesis. The observation that the formation of big inclusion bodies is reversible in vivo can be also relevant in the context of amyloid diseases, in which deposition of important amounts of aggregated protein initiates the pathogenic process.

  16. Microbial odor profile of polyester and cotton clothes after a fitness session.

    PubMed

    Callewaert, Chris; De Maeseneire, Evelyn; Kerckhof, Frederiek-Maarten; Verliefde, Arne; Van de Wiele, Tom; Boon, Nico

    2014-11-01

    Clothing textiles protect our human body against external factors. These textiles are not sterile and can harbor high bacterial counts as sweat and bacteria are transmitted from the skin. We investigated the microbial growth and odor development in cotton and synthetic clothing fabrics. T-shirts were collected from 26 healthy individuals after an intensive bicycle spinning session and incubated for 28 h before analysis. A trained odor panel determined significant differences between polyester versus cotton fabrics for the hedonic value, the intensity, and five qualitative odor characteristics. The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts. A dissimilar bacterial growth was found in cotton versus synthetic clothing textiles. Micrococci were isolated in almost all synthetic shirts and were detected almost solely on synthetic shirts by means of denaturing gradient gel electrophoresis fingerprinting. A selective enrichment of micrococci in an in vitro growth experiment confirmed the presence of these species on polyester. Staphylococci were abundant on both cotton and synthetic fabrics. Corynebacteria were not enriched on any textile type. This research found that the composition of clothing fibers promotes differential growth of textile microbes and, as such, determines possible malodor generation. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. Microbial Odor Profile of Polyester and Cotton Clothes after a Fitness Session

    PubMed Central

    Callewaert, Chris; De Maeseneire, Evelyn; Kerckhof, Frederiek-Maarten; Verliefde, Arne; Van de Wiele, Tom

    2014-01-01

    Clothing textiles protect our human body against external factors. These textiles are not sterile and can harbor high bacterial counts as sweat and bacteria are transmitted from the skin. We investigated the microbial growth and odor development in cotton and synthetic clothing fabrics. T-shirts were collected from 26 healthy individuals after an intensive bicycle spinning session and incubated for 28 h before analysis. A trained odor panel determined significant differences between polyester versus cotton fabrics for the hedonic value, the intensity, and five qualitative odor characteristics. The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts. A dissimilar bacterial growth was found in cotton versus synthetic clothing textiles. Micrococci were isolated in almost all synthetic shirts and were detected almost solely on synthetic shirts by means of denaturing gradient gel electrophoresis fingerprinting. A selective enrichment of micrococci in an in vitro growth experiment confirmed the presence of these species on polyester. Staphylococci were abundant on both cotton and synthetic fabrics. Corynebacteria were not enriched on any textile type. This research found that the composition of clothing fibers promotes differential growth of textile microbes and, as such, determines possible malodor generation. PMID:25128346

  18. Amyloid-linked cellular toxicity triggered by bacterial inclusion bodies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gonzalez-Montalban, Nuria; Departament de Genetica i de Microbiologia, Universitat Autonoma de Barcelona, Bellaterra, 08193 Barcelona; Ciber de Bioingenieria, Biomateriales y Nanomedicina

    The aggregation of proteins in the form of amyloid fibrils and plaques is the characteristic feature of some pathological conditions ranging from neurodegenerative disorders to systemic amyloidoses. The mechanisms by which the aggregation processes result in cell damage are under intense investigation but recent data indicate that prefibrillar aggregates are the most proximate mediators of toxicity rather than mature fibrils. Since it has been shown that prefibrillar forms of the nondisease-related misfolded proteins are highly toxic to cultured mammalian cells we have studied the cytoxicity associated to bacterial inclusion bodies that have been recently described as protein deposits presenting amyloid-likemore » structures. We have proved that bacterial inclusion bodies composed by a misfolding-prone {beta}-galactosidase fusion protein are clearly toxic for mammalian cells but the {beta}-galactosidase wild type enzyme forming more structured thermal aggregates does not impair cell viability, despite it also binds and enter into the cells. These results are in the line that the most cytotoxic aggregates are early prefibrilar assemblies but discard the hypothesis that the membrane destabilization is Key event to subsequent disruption of cellular processes, such as ion balance, oxidative state and the eventually cell death.« less

  19. Bio-modification of Cotton and Micro-denier Polyester with Sericin to Develop Potent Antibacterial and Antifungal Textile Products

    NASA Astrophysics Data System (ADS)

    Rajalakshmi, M.; Uddandrao, V. V. Sathibabu; Saravanan, G.; Vadivukkarasi, S.; Koushik, C. V.

    2018-06-01

    The present study was aimed to develop a novel textile product through bio modification of cotton and micro-denier polyester with sericin (Sn) against bacterial and fungal growth. The authors extracted and purified Sn from silk yellow cocoons. Sn solution (10 g/L) was incorporated into the 100% cotton (C), 100% micro-denier polyester (MDP) and 65/35 micro-denier polyester/cotton (MDP/C) in a padding mangle by a 2-dip/2-nip process and fabrics were analysed by Field-Emission scanning electron microscope. Fabrics were divided into six groups such as untreated groups (C, MDP and MDP/C) and Sn-treated groups (Sn + C, Sn + MDP and Sn + MDP/C) and then underwent organoleptic evaluation and as well as anti-bacterial (Staphylococcus aureus and Escherichia coli) and anti-fungal (Aspergillus niger and Trichoderma harzianum) activities. Sn treated fabrics were found to show the presence of Sn by scanning electron micrographs and also attained high organoleptic score from the panel members. In addition, the Sn-treated fabrics displayed outstanding anti bacterial and anti fungal properties in terms of both qualitative and quantitative analysis. Sn + MDP/C fabrics have shown potential reduction in bacterial and fungal growth when compared with other treated and untreated fabrics. Hence, this study suggests that bio modification of C, MDP and MDP/C with Sn may make them ideal candidate for their application in medical textiles against pathogens.

  20. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyester elastomers. 177.1590 Section 177.1590... Components of Single and Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester...) For the purpose of this section, polyester elastomers are those produced by the ester exchange...

  1. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyester elastomers. 177.1590 Section 177.1590... Components of Single and Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester...) For the purpose of this section, polyester elastomers are those produced by the ester exchange...

  2. Recovery of bioactive protein from bacterial inclusion bodies using trifluoroethanol as solubilization agent.

    PubMed

    Upadhyay, Vaibhav; Singh, Anupam; Jha, Divya; Singh, Akansha; Panda, Amulya K

    2016-06-08

    Formation of inclusion bodies poses a major hurdle in recovery of bioactive recombinant protein from Escherichia coli. Urea and guanidine hydrochloride have routinely been used to solubilize inclusion body proteins, but many times result in poor recovery of bioactive protein. High pH buffers, detergents and organic solvents like n-propanol have been successfully used as mild solubilization agents for high throughput recovery of bioactive protein from bacterial inclusion bodies. These mild solubilization agents preserve native-like secondary structures of proteins in inclusion body aggregates and result in improved recovery of bioactive protein as compared to conventional solubilization agents. Here we demonstrate solubilization of human growth hormone inclusion body aggregates using 30% trifluoroethanol in presence of 3 M urea and its refolding into bioactive form. Human growth hormone was expressed in E. coli M15 (pREP) cells in the form of inclusion bodies. Different concentrations of trifluoroethanol with or without addition of low concentration (3 M) of urea were used for solubilization of inclusion body aggregates. Thirty percent trifluoroethanol in combination with 3 M urea was found to be suitable for efficient solubilization of human growth hormone inclusion bodies. Solubilized protein was refolded by dilution and purified by anion exchange and size exclusion chromatography. Purified protein was analyzed for secondary and tertiary structure using different spectroscopic tools and was found to be bioactive by cell proliferation assay. To understand the mechanism of action of trifluoroethanol, secondary and tertiary structure of human growth hormone in trifluoroethanol was compared to that in presence of other denaturants like urea and guanidine hydrochloride. Trifluoroethanol was found to be stabilizing the secondary structure and destabilizing the tertiary structure of protein. Finally, it was observed that trifluoroethanol can be used to solubilize

  3. Properties of honeycomb polyester knitted fabrics

    NASA Astrophysics Data System (ADS)

    Feng, A. F.

    2016-07-01

    The properties of honeycomb polyester weft-knitted fabrics were studied to understand their advantages. Seven honeycomb polyester weft-knitted fabrics and one common polyester weft-knitted fabric were selected for testing. Their bursting strengths, fuzzing and pilling, air permeability, abrasion resistance and moisture absorption and perspiration were studied. The results show that the honeycomb polyester weft-knitted fabrics have excellent moisture absorption and liberation. The smaller their thicknesses and area densities are, the better their moisture absorption and liberation will be. Their anti-fuzzing and anti-pilling is good, whereas their bursting strengths and abrasion resistance are poorer compared with common polyester fabric's. In order to improve the hygroscopic properties of the fabrics, the proportion of the honeycomb microporous structure modified polyester in the fabrics should not be less than 40%.

  4. L-arginine mediated renaturation enhances yield of human, α6 type IV collagen non-collagenous domain from bacterial inclusion bodies

    PubMed Central

    Gunda, Venugopal; Boosani, Chandra Shekhar; Verma, Raj Kumar; Guda, Chittibabu; Akul Sudhakar, Yakkanti

    2012-01-01

    The anti-angiogenic, carboxy terminal non-collagenous domain (NC1) derived from human Collagen type IV alpha 6 chain, [α6(IV)NC1] or hexastatin, was earlier obtained using different recombinant methods of expression in bacterial systems. However, the effect of L-arginine mediated renaturation in enhancing the relative yields of this protein from bacterial inclusion bodies has not been evaluated. In the present study, direct stirring and on-column renaturation methods using L-arginine and different size exclusion chromatography matrices were applied for enhancing the solubility in purifying the recombinant α6(IV)NC1 from bacterial inclusion bodies. This methodology enabled purification of higher quantities of soluble protein from inclusion bodies, which inhibited endothelial cell proliferation, migration and tube formation. Thus, the scope for L-arginine mediated renaturation in obtaining higher yields of soluble, biologically active NC1 domain from bacterial inclusion bodies was evaluated. PMID:22512648

  5. L-arginine mediated renaturation enhances yield of human, α6 Type IV collagen non-collagenous domain from bacterial inclusion bodies.

    PubMed

    Gunda, Venugopal; Boosani, Chandra Shekhar; Verma, Raj Kumar; Guda, Chittibabu; Sudhakar, Yakkanti Akul

    2012-10-01

    The anti-angiogenic, carboxy terminal non-collagenous domain (NC1) derived from human Collagen type IV alpha 6 chain, [α6(IV)NC1] or hexastatin, was earlier obtained using different recombinant methods of expression in bacterial systems. However, the effect of L-arginine mediated renaturation in enhancing the relative yields of this protein from bacterial inclusion bodies has not been evaluated. In the present study, direct stirring and on-column renaturation methods using L-arginine and different size exclusion chromatography matrices were applied for enhancing the solubility in purifying the recombinant α6(IV)NC1 from bacterial inclusion bodies. This methodology enabled purification of higher quantities of soluble protein from inclusion bodies, which inhibited endothelial cell proliferation, migration and tube formation. Thus, the scope for L-arginine mediated renaturation in obtaining higher yields of soluble, biologically active NC1 domain from bacterial inclusion bodies was evaluated.

  6. 49 CFR 173.165 - Polyester resin kits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Polyester resin kits. 173.165 Section 173.165... Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base... will not interact dangerously in the event of leakage. (b) For transportation by aircraft, polyester...

  7. Architecture of Amylose Supramolecules in Form of Inclusion Complexes by Phosphorylase-Catalyzed Enzymatic Polymerization

    PubMed Central

    Kadokawa, Jun-ichi

    2013-01-01

    This paper reviews the architecture of amylose supramolecules in form of inclusion complexes with synthetic polymers by phosphorylase-catalyzed enzymatic polymerization. Amylose is known to be synthesized by enzymatic polymerization using α-d-glucose 1-phosphate as a monomer, by phosphorylase catalysis. When the phosphorylase-catalyzed enzymatic polymerization was conducted in the presence of various hydrophobic polymers, such as polyethers, polyesters, poly(ester-ether), and polycarbonates as a guest polymer, such inclusion supramolecules were formed by the hydrophobic interaction in the progress of polymerization. Because the representation of propagation in the polymerization is similar to the way that a vine of a plant grows, twining around a rod, this polymerization method for the formation of amylose-polymer inclusion complexes was proposed to be named “vine-twining polymerization”. To yield an inclusion complex from a strongly hydrophobic polyester, the parallel enzymatic polymerization system was extensively developed. The author found that amylose selectively included one side of the guest polymer from a mixture of two resemblant guest polymers, as well as a specific range in molecular weights of the guest polymers poly(tetrahydrofuran) (PTHF) in the vine-twining polymerization. Selective inclusion behavior of amylose toward stereoisomers of chiral polyesters, poly(lactide)s, also appeared in the vine-twining polymerization. PMID:24970172

  8. 40 CFR 721.9507 - Polyester silane.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyester silane. 721.9507 Section 721... Polyester silane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a polyester silane (P-95-1022) is subject to reporting under this section for the...

  9. 40 CFR 721.9507 - Polyester silane.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester silane. 721.9507 Section 721... Polyester silane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a polyester silane (P-95-1022) is subject to reporting under this section for the...

  10. Tunable geometry of bacterial inclusion bodies as substrate materials for tissue engineering

    NASA Astrophysics Data System (ADS)

    García-Fruitós, Elena; Seras-Franzoso, Joaquín; Vazquez, Esther; Villaverde, Antonio

    2010-05-01

    A spectrum of materials for biomedical applications is produced in bacteria, and some of them, such as metals or polyhydroxyalkanoates, are straightforwardly obtained as particulate entities. We have explored the biofabrication process of bacterial inclusion bodies, particulate proteinaceous materials (ranging from 50 to 500 nm in diameter) recently recognized as suitable for surface topographical modification and tissue engineering. Inclusion bodies have been widely described as spherical or pseudo-spherical particles with only minor morphological variability, mostly restricted to their size. Here we have identified a cellular gene in Escherichia coli (clpP) that controls the in vivo fabrication process of inclusion bodies. In the absence of the encoded protease, the dynamics of protein deposition is perturbed, resulting in unusual tear-shaped particles with enhanced surface-volume ratios. This fact modifies the ability of inclusion bodies to promote mammalian cell attachment and differentiation upon surface decoration. The implications of the genetic control of inclusion body geometry are discussed in the context of their biological fabrication and regarding the biomedical potential of these protein clusters in regenerative medicine.

  11. Polyester Resin Hazards

    PubMed Central

    Bourne, L. B.; Milner, F. J. M.

    1963-01-01

    Polyester resins are being increasingly used in industry. These resins require the addition of catalysts and accelerators. The handling of polyester resin system materials may give rise to skin irritations, allergic reactions, and burns. The burns are probably due to styrene and organic peroxides. Atmospheric pollution from styrene and explosion and fire risks from organic peroxides must be prevented. Where dimethylaniline is used scrupulous cleanliness and no-touch technique must be enforced. Handling precautions are suggested. Images PMID:14014495

  12. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

  13. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

  14. Isolation of biologically active nanomaterial (inclusion bodies) from bacterial cells.

    PubMed

    Peternel, Spela; Komel, Radovan

    2010-09-10

    In recent years bacterial inclusion bodies (IBs) were recognised as highly pure deposits of active proteins inside bacterial cells. Such active nanoparticles are very interesting for further downstream protein isolation, as well as for many other applications in nanomedicine, cosmetic, chemical and pharmaceutical industry.To prepare large quantities of a high quality product, the whole bioprocess has to be optimised. This includes not only the cultivation of the bacterial culture, but also the isolation step itself, which can be of critical importance for the production process.To determine the most appropriate method for the isolation of biologically active nanoparticles, three methods for bacterial cell disruption were analyzed. In this study, enzymatic lysis and two mechanical methods, high-pressure homogenization and sonication, were compared.During enzymatic lysis the enzyme lysozyme was found to attach to the surface of IBs, and it could not be removed by simple washing. As this represents an additional impurity in the engineered nanoparticles, we concluded that enzymatic lysis is not the most suitable method for IBs isolation.During sonication proteins are released (lost) from the surface of IBs and thus the surface of IBs appears more porous when compared to the other two methods. We also found that the acoustic output power needed to isolate the IBs from bacterial cells actually damages proteins structures, thereby causing a reduction in biological activity.High-pressure homogenization also caused some damage to IBs, however the protein loss from the IBs was negligible. Furthermore, homogenization had no side-effects on protein biological activity. The study shows that among the three methods tested, homogenization is the most appropriate method for the isolation of active nanoparticles from bacterial cells.

  15. Surface Modification of Polyester Fiber with Perfluorooctyltrimethoxysilane

    NASA Astrophysics Data System (ADS)

    Wang, Xiangcheng; Liu, Yadong; Li, Dan; Tie, Zihan

    2018-05-01

    An excellent modified polyester fiber was prepared via chemical grafting between polyester fiber and perfluorooctyltrimethoxysilane (FAS-17), or silane coupler (KH-570), or Titanate coupler (DN-101) in isopropyl alcohol aqueous solution. Volume ratio of isopropyl alcohol in aqueous solution was 50:50, the mass concentration of FAS-17 is 2%, reacting on polyester fiber modified for 24h at 60 °C, the polyester fiber contact angle to water was 145 °, and the contact angle to peanut oil was 118 °, with excellent performance of amphiphobic property. KH-570 and DN-101 modified polymer fiber to be hydrophobic properties nearly as FAS-17, but modified polyester fiber have no amphiphobic property.

  16. 40 CFR 721.6485 - Hydroxy terminated polyester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hydroxy terminated polyester. 721.6485... Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydroxy terminated polyester...

  17. 40 CFR 721.6485 - Hydroxy terminated polyester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydroxy terminated polyester. 721.6485... Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydroxy terminated polyester...

  18. 49 CFR 173.165 - Polyester resin kits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Polyester resin kits. 173.165 Section 173.165... Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base... resin kits consisting of a base material component (Class 3, Packing Group II or III) and an activator...

  19. Isolation of biologically active nanomaterial (inclusion bodies) from bacterial cells

    PubMed Central

    2010-01-01

    Background In recent years bacterial inclusion bodies (IBs) were recognised as highly pure deposits of active proteins inside bacterial cells. Such active nanoparticles are very interesting for further downstream protein isolation, as well as for many other applications in nanomedicine, cosmetic, chemical and pharmaceutical industry. To prepare large quantities of a high quality product, the whole bioprocess has to be optimised. This includes not only the cultivation of the bacterial culture, but also the isolation step itself, which can be of critical importance for the production process. To determine the most appropriate method for the isolation of biologically active nanoparticles, three methods for bacterial cell disruption were analyzed. Results In this study, enzymatic lysis and two mechanical methods, high-pressure homogenization and sonication, were compared. During enzymatic lysis the enzyme lysozyme was found to attach to the surface of IBs, and it could not be removed by simple washing. As this represents an additional impurity in the engineered nanoparticles, we concluded that enzymatic lysis is not the most suitable method for IBs isolation. During sonication proteins are released (lost) from the surface of IBs and thus the surface of IBs appears more porous when compared to the other two methods. We also found that the acoustic output power needed to isolate the IBs from bacterial cells actually damages proteins structures, thereby causing a reduction in biological activity. High-pressure homogenization also caused some damage to IBs, however the protein loss from the IBs was negligible. Furthermore, homogenization had no side-effects on protein biological activity. Conclusions The study shows that among the three methods tested, homogenization is the most appropriate method for the isolation of active nanoparticles from bacterial cells. PMID:20831775

  20. Synthesis of improved polyester resins

    NASA Technical Reports Server (NTRS)

    Mcleod, A. H.; Delano, C. B.

    1979-01-01

    Eighteen aromatic unsaturated polyester prepolymers prepared by a modified interfacial condensation technique were investigated for their solubility in vinyl monomers and ability to provide high char yield forming unsaturated polyester resins. The best resin system contained a polyester prepolymer of phthalic, fumaric and diphenic acids reacted with 2,7-naphthalene diol and 9,9-bis(4-hydroxyphenyl)fluorene. This prepolymer is very soluble in styrene, divinyl benzene, triallyl cyanurate, diallyl isophthalate and methylvinylpyridine. It provided anaerobic char yields as high as 41 percent at 800 C. The combination of good solubility and char yield represents a significant improvement over state-of-the-art unsaturated polyester resins. The majority of the other prepolymers had only low or no solubility in vinyl monomers. Graphite composites from this prepolymer with styrene were investigated. The cause for the observed low shear strengths of the composites was not determined, however 12-week aging of the composites at 82 C showed that essentially no changes in the composites had occurred.

  1. Polyester projects for India, Pakistan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siddiqi, R.

    1993-02-10

    India's Indo Rama Synthetics (Bombay) is planning a $186-million integrated polyester fiber and filament complex at Nagpur, Maharashtra. The complex will have annual capacities for 38,000 m.t. of polyester chips by polycondensation, 25,000 m.t. of polyester staple fiber, and 12,000 m.t. of polyester blended yarn. The company is negotiating with the main world suppliers of polycondensation technology. The first stage of the project is slated to begin production by the end of this year and be fully completed by 1994. In Pakistan, National Fibers Ltd. (PNF; Karachi) has signed a deal with Zimmer (Frankfurt) for technology, procurement, construction, and supportmore » work to expand polyester staple fiber capacity from 14,000 m.t./year to 52,000 m.t./year. The technology involves a continuous polymerization process. The project also calls for improvements to PNF's existing batch plant. It is scheduled for completion by the end of 1994. Total cost of the project is estimated at Rs1.745 billion ($70 million), out of which the foreign exchange component is Rs1.05 billion. The Islamic Development Bank (Jeddah; Saudi Arabia) has already approved a $27-million slice of the financing, while the balance of the foreign exchange loan is being arranged through suppliers credit. Local currency loans will be provided by other financial institutions in Pakistan.« less

  2. Limit for the Survivability from Potassium Decay of Bacterial Spores in Halite Fluid Inclusions

    NASA Astrophysics Data System (ADS)

    Kminek, G.; Bada, J. L.

    2001-12-01

    Vreeland et al.1 recently claimed to have isolated and cultured a viable spore forming halotolerant bacterium from a 250 million year old brine inclusion present in a salt crystal from the Salado formation. An earlier report suggested that viable bacterial spores could be revived from samples obtained from insects entombed in 25-40 million year old Dominican amber2. On the bases of these reports, Parkes3 raised the question of whether bacterial spores under some conditions might be effectively immortal. Sporulation, induced by an adverse change in the environmental conditions, is able to stabilize the DNA primarily against hydrolytic depurination for extended periods of time4. However, the organism is still exposed to ionizing radiation from the environment. Dormant spores have a reduced sensitivity to ionizing radiation per se, but unlike active organisms are unable to repair DNA damage encountered during long-term exposure to ionizing radiation. The accumulated damage may overwhelm any repair mechanism that starts in the early stage of spore germination5. The main radionuclide in a halite fluid inclusion is 40K, which accounts for 0.0117% of natural potassium. 40K decays via beta decay to 40Ca and via electron capture to 40Ar, releasing a primary gamma-ray. About 83.3 % of the beta's emitted are in the energy range of 0.3-1.3 MeV. We assume 7 g/l for an average concentration of natural potassium in a halite fluid inclusion, which means that the amount of 40K in a 10 μ l fluid inclusion is 8.19 ng. We have chosen a 10 μ l because this volume is typical of that used to obtain chemical data and in the attempts to extract bacteria. Less than a percent of the gamma decay energy is absorbed in a fluid inclusion of 10 μ l. Thus, we will not take the gamma decay energy into account for the further discussion. Almost all the beta energy is absorbed in the fluid inclusion. The total decay energy absorbed in a time period of 250 million years is about 87 kGy. The most

  3. Radiation-Dependent Limit for the Viability of Bacterial Spores in Halite Fluid Inclusions and on Mars

    PubMed Central

    Kminek, Gerhard; Bada, Jeffrey L.; Pogliano, Kit; Ward, John F.

    2014-01-01

    Kminek, G., Bada, J. L., Pogliano, K. and Ward, J. F. Radiation-Dependent Limit for the Viability of Bacterial Spores in Halite Fluid Inclusions and on Mars. Radiat. Res. 159, 722–729 (2003). When claims for the long-term survival of viable organisms are made, either within terrestrial minerals or on Mars, considerations should be made of the limitations imposed by the naturally occurring radiation dose to which they have been exposed. We investigated the effect of ionizing radiation on different bacterial spores by measuring the inactivation constants for B. subtilis and S. marismortui spores in solution as well as for dry spores of B. subtilis and B. thuringiensis. S. marismortui is a halophilic spore that is genetically similar to the recently discovered 2-9-3 bacterium from a halite fluid inclusion, claimed to be 250 million years old (Vreeland et al., Nature 407, 897–900, 2000). B. thuringiensis is a soil bacterium that is genetically similar to the human pathogens B. anthracis and B. cereus (Helgason et al., Appl. Environ. Microbiol. 66, 2627–2630, 2000). To relate the inactivation constant to some realistic environments, we calculated the radiation regimen in a halite fluid inclusion and in the Martian subsurface over time. Our conclusion is that the ionizing dose of radiation in those environments limits the survival of viable bacterial spores over long periods. In the absence of an active repair mechanism in the dormant state, the long-term survival of spores is limited to less than 109 million years in halite fluid inclusions, to 100 to 160 million years in the Martian subsurface below 3 m, and to less than 600,000 years in the uppermost meter of Mars. PMID:12751954

  4. Synthetic polyester-hydrolyzing enzymes from thermophilic actinomycetes.

    PubMed

    Wei, Ren; Oeser, Thorsten; Zimmermann, Wolfgang

    2014-01-01

    Thermophilic actinomycetes produce enzymes capable of hydrolyzing synthetic polyesters such as polyethylene terephthalate (PET). In addition to carboxylesterases, which have hydrolytic activity predominantly against PET oligomers, esterases related to cutinases also hydrolyze synthetic polymers. The production of these enzymes by actinomycetes as well as their recombinant expression in heterologous hosts is described and their catalytic activity against polyester substrates is compared. Assays to analyze the enzymatic hydrolysis of synthetic polyesters are evaluated, and a kinetic model describing the enzymatic heterogeneous hydrolysis process is discussed. Structure-function and structure-stability relationships of actinomycete polyester hydrolases are compared based on molecular dynamics simulations and recently solved protein structures. In addition, recent progress in enhancing their activity and thermal stability by random or site-directed mutagenesis is presented. © 2014 Elsevier Inc. All rights reserved.

  5. 40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyether polyester copolymer... Specific Chemical Substances § 721.10213 Polyether polyester copolymer phosphate (generic). (a) Chemical... as polyether polyester copolymer phosphate (PMN P-09-253) is subject to reporting under this section...

  6. Microbial degradation of polyurethane, polyester polyurethanes and polyether polyurethanes.

    PubMed

    Nakajima-Kambe, T; Shigeno-Akutsu, Y; Nomura, N; Onuma, F; Nakahara, T

    1999-02-01

    Polyurethane (PUR) is a polymer derived from the condensation of polyisocyanate and polyol and it is widely used as a base material in various industries. PUR, in particular, polyester PUR, is known to be vulnerable to microbial attack. Recently, environmental pollution by plastic wastes has become a serious issue and polyester PUR had attracted attention because of its biodegradability. There are many reports on the degradation of polyester PUR by microorganisms, especially by fungi. Microbial degradation of polyester PUR is thought to be mainly due to the hydrolysis of ester bonds by esterases. Recently, polyester-PUR-degrading enzymes have been purified and their characteristics reported. Among them, a solid-polyester-PUR-degrading enzyme (PUR esterase) derived from Comamonas acidovorans TB-35 had unique characteristics. This enzyme has a hydrophobic PUR-surface-binding domain and a catalytic domain, and the surface-binding domain was considered as being essential for PUR degradation. This hydrophobic surface-binding domain is also observed in other solid-polyester-degrading enzymes such as poly(hydroxyalkanoate) (PHA) depolymerases. There was no significant homology between the amino acid sequence of PUR esterase and that of PHA depolymerases, except in the hydrophobic surface-binding region. Thus, PUR esterase and PHA depolymerase are probably different in terms of their evolutionary origin and it is possible that PUR esterases come to be classified as a new solid-polyester-degrading enzyme family.

  7. RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS

    EPA Science Inventory

    The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...

  8. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Partial phosphoric acid esters of polyester resins... of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section... prescribed conditions: (a) For the purpose of this section, partial phosphoric acid esters of polyester...

  9. Blends of polyester ionomers with polar polymers: Interactions, reactions, and compatibilization

    NASA Astrophysics Data System (ADS)

    Boykin, Timothy Lamar

    The compatibility of amorphous and semicrystalline polyester ionomers with various polar polymers (i.e., polyesters and polyamides) has been investigated for their potential use as minor component compatibilizers. The degree of compatibility (i.e., ranging from incompatible to miscible) between the polyester ionomers and the polar polymers was determined by evaluating the effect of blend composition on the melting behavior and phase behavior of binary blends. In addition, the origin of compatibility and/or incompatibility for each of the binary blends (i.e., polyamide/ionomer and polyester/ionomer) was determined by evaluating blends prepared by both solution and melt mixed methods. Subsequent to investigation of the binary blends, the effect of polyester ionomer addition on the compatibility of polyamide/polyester blends was investigated by evaluating the mechanical properties and phase morphology of ionomer compatibilized polyamide/polyester blends. Polyester ionomers (amorphous and semicrystalline) were shown to exhibit a high degree of compatibility (even miscibility) with polyamides, such as nylon 6,6 (N66). Compatibility was attributed to specific interactions between the metal counterion of the polyester ionomer and the amide groups of N66. The degree of compatibility (or miscibility) was shown to be dependent on the counterion type of the ionomer, with the highest degree exhibited by blends containing the divalent form of the polyester ionomers. Although polyester ionomers were shown to exhibit incompatibility with both poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), increasing the time of melt processing significantly enhanced the compatibility of the polyester ionomers with both PET and PBT. The observed enhancement in compatibility was attributed to ester-ester interchange between the polyester blend components, which was confirmed by NMR spectroscopy. The addition of polyester ionomers as a minor component compatibilizer (i

  10. Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

    PubMed

    Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

    2014-04-01

    Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

  11. Rab11-family of interacting protein 2 associates with chlamydial inclusions through its Rab-binding domain and promotes bacterial multiplication.

    PubMed

    Leiva, Natalia; Capmany, Anahí; Damiani, María Teresa

    2013-01-01

    Chlamydia trachomatis, an obligate intracellular pathogen, survives within host cells in a special compartment named 'inclusion' and takes advantage of host vesicular transport pathways for its growth and replication. Rab GTPases are key regulatory proteins of intracellular trafficking. Several Rabs, among them Rab11 and Rab14, are implicated in chlamydial development. FIP2, a member of the Rab11-Family of Interacting Proteins, presents at the C-terminus a Rab-binding domain that interacts with both Rab11 and Rab14. In this study, we determined and characterized the recruitment of endogenous and GFP-tagged FIP2 to the chlamydial inclusions. The recruitment of FIP2 is specific since other members of the Rab11-Family of Interacting Proteins do not associate with the chlamydial inclusions. The Rab-binding domain of FIP2 is essential for its association. Our results indicate that FIP2 binds to Rab11 at the chlamydial inclusion membrane through its Rab-binding domain. The presence of FIP2 at the chlamydial inclusion favours the recruitment of Rab14. Furthermore, our results show that FIP2 promotes inclusion development and bacterial replication. In agreement, the silencing of FIP2 decreases the bacterial progeny. C. trachomatis likely recruits FIP2 to hijack host intracellular trafficking to redirect vesicles full of nutrients towards the inclusion. © 2012 Blackwell Publishing Ltd.

  12. 21 CFR 177.2420 - Polyester resins, cross-linked.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... following prescribed conditions: (a) The cross-linked polyester resins are produced by the condensation of... fiber Polyester fiber produced by the condensation of one or more of the acids listed in paragraph (a)(1...

  13. Studies on thermo-mechanical properties of chemically treated jute-polyester composite

    NASA Astrophysics Data System (ADS)

    Chaudhari, Vikas; Chandekar, Harichandra; Saboo, Jayesh; Mascarenhas, Adlete

    2018-03-01

    The effect of chemical treatments on jute-polyester composites is studied in this paper. The jute fabrics are chemically treated with NaOH and benzoyl chloride and its tensile and visco-elastic properties are compared with untreated jute composite. The NaOH treated jute-polyester composite show superior tensile strength and modulus compared to other jute-polyester composites. The glass transition temperature obtained from DMA shift to higher temperature for composites in comparison to polyester resin, this is due to restriction of mobility in chains due to introduction of jute reinforcement. The DMA results also show favourable results towards NaOH treatment i.e. higher storage modulus and lower tan δ values relative to untreated jute-polyester composite. The benzoyl treated jute-polyester composite however do not show promising results which may be attributed to the fact that the adhesion properties associated with similar ester functional groups in the benzoyl treated jute fabric and polyester resin were not obtained.

  14. 21 CFR 177.2420 - Polyester resins, cross-linked.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... polyester resins are produced by the condensation of one or more of the acids listed in paragraph (a)(1) of.... Reinforcements: Asbestos Glass fiber Polyester fiber produced by the condensation of one or more of the acids...

  15. 21 CFR 177.2420 - Polyester resins, cross-linked.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polyester resins are produced by the condensation of one or more of the acids listed in paragraph (a)(1) of.... Reinforcements: Asbestos Glass fiber Polyester fiber produced by the condensation of one or more of the acids...

  16. Radiation-Dependent Limit for the Viability of Bacterial Spores in Halite Fluid Inclusions and on Mars

    NASA Technical Reports Server (NTRS)

    Kminek, Gerhard; Bada, Jeffrey L.; Pogliano, Kit; Ward, John F.

    2003-01-01

    When claims for the long-term survival of viable organisms are made, either within terrestrial minerals or on Mars, considerations should be made of the limitations imposed by the naturally occurring radiation dose to which they have been exposed. We investigated the effect of ionizing radiation on different bacterial spores by measuring the inactivation constants for B. subtilis and s. marismortui spores in solution as well as for dry spores of B. subtilis and B. thuringiensis. S. marismortui is a halophilic spore that is genetically similar to the recently discovered 2-9-3 bacterium from a halite fluid inclusion, claimed to be 250 million years old, B. thuringiensis is a soil bacterium that is genetically similar to the human pathogens B. anthracis and B. cereus. To relate the inactivation constant to some realistic environments, we calculated the radiation regimen in a halite fluid inclusion and in the Martian subsurface over time. Our conclusion is that the ionizing dose of radiation in those environments limits the survival of viable bacterial spores over long periods. In the absence of an active repair mechanism in the dormant state, the long-term survival of spores is limited to less than 109 million years in halite fluid inclusions, to 100 to 160 million years in the Martian subsurface below 3 m, and to less than 600,000 years in the upper-most meter of Mars.

  17. Study on moisture absorption and sweat discharge of honeycomb polyester fiber

    NASA Astrophysics Data System (ADS)

    Feng, Aifen; Zhang, Yongjiu

    2015-07-01

    The moisture absorption and liberation properties of honeycomb polyester fiber were studied in order to understand its moisture absorption and sweat discharge. Through testing moisture absorption and liberation regains of honeycomb polyester fiber and normal polyester fiber in standard atmospheric conditions, their moisture absorption and liberation curves were depicted, and the regression equations of moisture regains to time during their reaching the balance of moisture absorption and moisture liberation were obtained according to the curves. Their moisture absorption and liberation rate curves were analyzed and the regression equations of the rates to time were obtained. The results shows that the moisture regain of honeycomb polyester fiber is much bigger than the normal polyester fiber's, and the initial moisture absorption and moisture liberation rates of the former are much higher than the latter's, so that the moisture absorbance and sweat discharge of honeycomb polyester fiber are excellent.

  18. Isohexide and Sorbitol-Derived, Enzymatically Synthesized Renewable Polyesters with Enhanced Tg.

    PubMed

    Gustini, Liliana; Lavilla, Cristina; de Ilarduya, Antxon Martínez; Muñoz-Guerra, Sebastián; Koning, Cor E

    2016-10-10

    Sugar-based polyesters derived from sorbitol and isohexides were obtained via solvent-free enzymatic catalysis. Pendant hydroxyl groups, coming from the sorbitol units, were present along the polyester backbone, whereas the two isohexides, namely, isomannide and isoidide dimethyl ester monomers, were selected to introduce rigidity into the polyester chains. The feasibility of incorporating isomannide as a diol compared to the isoidide dimethyl ester as acyl-donor via lipase-catalyzed polycondensation was investigated. The presence of bicyclic units resulted in enhanced T g with respect to the parent sorbitol-containing polyester lacking isohexides. The different capability of the two isohexides to boost the thermal properties confirmed the more flexible character provided by the isoidide diester derivative. Solvent-borne coatings were prepared by cross-linking the sugar-based polyester polyols with polyisocyanates. The increased rigidity of the obtained sugar-based polyester polyols led to an enhancement in hardness of the resulting coatings.

  19. (Citric acid–co–polycaprolactone triol) polyester

    PubMed Central

    Thomas, Lynda V.; Nair, Prabha D.

    2011-01-01

    Tissue engineering holds enormous challenges for materials science, wherein the ideal scaffold to be used is expected to be biocompatible, biodegradable and possess mechanical and physical properties that are suitable for target application. In this context, we have prepared degradable polyesters in different ratios by a simple polycondensation technique with citric acid and polycaprolactone triol. Differential scanning calorimetry indicated that the materials were amorphous based the absence of a crystalline melting peak and the presence of a glass transition temperature below 37°C. These polyesters were found to be hydrophilic and could be tailor-made into tubes and films. Porosity could also be introduced by addition of porogens. All the materials were non-cytotoxic in an in vitro cytotoxicity assay and may degrade via hydrolysis to non-toxic degradation products. These polyesters have potential implications in the field of soft tissue engineering on account of their similarity of properties. PMID:23507730

  20. Liquid crystal polyester thermosets

    DOEpatents

    Benicewicz, Brian C.; Hoyt, Andrea E.

    1992-01-01

    The present invention provides (1) curable liquid crystalline polyester monomers represented by the formula: R.sup.1 --A.sup.1 --B.sup.1 --A.sup.2 --B.sup.2 --A.sup.3 --R.sup.2 where R.sup.1 and R.sup.2 are radicals selected from the group consisting of maleimide, substituted maleimide, nadimide, substituted naimide, ethynyl, and (C(R.sup.3).sub.2).sub.2 where R.sup.3 is hydrogen with the proviso that the two carbon atoms of (C(R.sup.3).sub.2).sub.2 are bound on the aromatic ring of A.sup.1 or A.sup.3 to adjacent carbon atoms, A.sup.1 and A.sup.3 are 1,4-phenylene and the same where said group contains one or more substituents selected from the group consisting of halo, e.g., fluoro, chloro, bromo, or iodo, nitro lower alkyl, e.g., methyl, ethyl, or propyl, alkoxy, e.g., methoxy, ethoxy, or propoxy, and fluoroalkyl, e.g., trifluoromethyl, pentafluoroethyl and the like, A.sup.2 is selected from the group consisting of 1,4-phenylene, 4,4'-biphenyl, 2,6-naphthylene and the same where said groups contain one or more substituents selected from the group consisting of halo, e.g., fluoro, chloro, bromo, or iodo, nitro, lower alkyl, e.g., methyl, ethyl, and propyl, lower alkoxy, e.g., methoxy, ethoxy, or propoxy, and fluoroalkyl or fluoroalkoxy, e.g., trifluoromethyl, pentafluoroethyl and the like, and B.sup.1 and B.sup.2 are selected from the group consisting of --C(O)--O-- and --O--C(O)--, (2) thermoset liquid crystalline polyester compositions comprised of heat-cured segments derived from monomers represented by the formula: R.sup.1 --A.sup.1 --B.sup.1 --A.sup.2 --B.sup.2 --A.sup.3 --R.sup.2 as described above, (3) curable blends of at least two of the polyester monomers and (4) processes of preparing the curable liquid crystalline polyester monomers.

  1. 76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... Polyester Staple Fiber From Korea and Taiwan Determination On the basis of the record \\1\\ developed in the... antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to lead to...), entitled Certain Polyester Staple Fiber From Korea and Taiwan: Investigation Nos. 731-TA-825 and 826...

  2. 75 FR 42784 - Greige Polyester/Cotton Printcloth From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-101 (Third Review)] Greige Polyester/Cotton Printcloth From China AGENCY: United States International Trade Commission. ACTION: Termination of... revocation of the antidumping duty order on greige polyester/cotton printcloth from China would be likely to...

  3. Degradation of microbial polyesters.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P

    2004-08-01

    Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

  4. 75 FR 23300 - Greige Polyester/Cotton Printcloth From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    .../Cotton Printcloth From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on greige polyester/cotton printcloth from... antidumping duty order on greige polyester/cotton printcloth from China would be likely to lead to...

  5. Recent advances in aliphatic polyesters for drug delivery applications.

    PubMed

    Washington, Katherine E; Kularatne, Ruvanthi N; Karmegam, Vasanthy; Biewer, Michael C; Stefan, Mihaela C

    2017-07-01

    The use of aliphatic polyesters in drug delivery applications has been a field of significant interest spanning decades. Drug delivery strategies have made abundant use of polyesters in their structures owing to their biocompatibility and biodegradability. The properties afforded from these materials provide many avenues for the tunability of drug delivery systems to suit individual needs of diverse applications. Polyesters can be formed in several different ways, but the most prevalent is the ring-opening polymerization of cyclic esters. When used to form amphiphilic block copolymers, these materials can be utilized to form various drug carriers such as nanoparticles, micelles, and polymersomes. These drug delivery systems can be tailored through the addition of targeting moieties and the addition of stimuli-responsive groups into the polymer chains. There are also different types of polyesters that can be used to modify the degradation rates or mechanical properties. Here, we discuss the reasons that polyesters have become so popular, the current research focuses, and what the future holds for these materials in drug delivery applications. WIREs Nanomed Nanobiotechnol 2017, 9:e1446. doi: 10.1002/wnan.1446 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

  6. 77 FR 60720 - Certain Polyester Staple Fiber From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... Fiber From China Determination On the basis of the record \\1\\ developed in the subject five-year review... certain polyester staple fiber from China would be likely to lead to continuation or recurrence of... (September 2012), entitled Certain Polyester Staple Fiber from China: Investigation No. 731-TA-1104 (Review...

  7. A mathematical approach to molecular organization and proteolytic disintegration of bacterial inclusion bodies.

    PubMed

    Cubarsi, R; Carrió, M M; Villaverde, A

    2005-09-01

    The in vivo proteolytic digestion of bacterial inclusion bodies (IBs) and the kinetic analysis of the resulting protein fragments is an interesting approach to investigate the molecular organization of these unconventional protein aggregates. In this work, we describe a set of mathematical instruments useful for such analysis and interpretation of observed data. These methods combine numerical estimation of digestion rate and approximation of its high-order derivatives, modelling of fragmentation events from a mixture of Poisson processes associated with differentiated protein species, differential equations techniques in order to estimate the mixture parameters, an iterative predictor-corrector algorithm for describing the flow diagram along the cascade process, as well as least squares procedures with minimum variance estimates. The models are formulated and compared with data, and successively refined to better match experimental observations. By applying such procedures as well as newer improved algorithms of formerly developed equations, it has been possible to model, for two kinds of bacterially produced aggregation prone recombinant proteins, their cascade digestion process that has revealed intriguing features of the IB-forming polypeptides.

  8. Interior microelectrolysis oxidation of polyester wastewater and its treatment technology.

    PubMed

    Yang, Xiaoyi

    2009-09-30

    This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

  9. Polyester polymer concrete overlay.

    DOT National Transportation Integrated Search

    2013-01-01

    Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement d...

  10. 40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polymer (generic). 721.10298 Section 721.10298 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). (a... generically as MDI terminated polyester polyurethane polymer (P-11-662) is subject to reporting under this...

  11. 40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polymer (generic). 721.10298 Section 721.10298 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). (a... generically as MDI terminated polyester polyurethane polymer (P-11-662) is subject to reporting under this...

  12. 40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polymer (generic). 721.10298 Section 721.10298 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). (a... generically as MDI terminated polyester polyurethane polymer (P-11-662) is subject to reporting under this...

  13. Eco-friendly surface modification on polyester fabrics by esterase treatment

    NASA Astrophysics Data System (ADS)

    Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping

    2014-03-01

    Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

  14. Degradation rates of glycerol polyesters at acidic and basic conditions

    USDA-ARS?s Scientific Manuscript database

    Polyesters prepared from glycerol with mixtures of adipic and citric acids were evaluated in the laboratory to estimate degradation rates over a range of pH conditions. These renewable polymers provide a market for glycerol that is generated during biodiesel production. The polyesters were prepared...

  15. Stabilized unsaturated polyesters

    NASA Technical Reports Server (NTRS)

    Vogl, O.; Borsig, E. (Inventor)

    1985-01-01

    An unsaturated polyester, such as propylene glycolmaleic acid phthalic acid prepolymer dissolved in styrene is interpolymerized with an ultraviolet absorber and/or an antioxidant. The unsaturated chain may be filled with H or lower alkyl such as methyl and tertiary alkyl such as tertiary butyl. A polymer stable to exposure to the outdoors without degradation by ultraviolet radiation, thermal and/or photooxidation is formed.

  16. 78 FR 51707 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... certain polyester staple fiber (polyester staple fiber) from the Republic of Korea (Korea) for the period..., 2013, the Department initiated an administrative review of the antidumping duty order on polyester...

  17. 75 FR 43921 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... certain polyester staple fiber from Taiwan. The period of review is May 1, 2008, through April 30, 2009... polyester staple fiber (PSF) from Taiwan. See Certain Polyester Staple Fiber From Taiwan: Preliminary...

  18. SOLUTION RHEOLOGY OF HYPERBRANCHED POLYESTERS AND THEIR BLENDS WITH LINEAR POLYMERS

    EPA Science Inventory

    In this study, the rheological properties of different generations of hyperbranched polyesters in 1-methyl-2-pyrrolidinone solvent and their blends with poly(2-hydroxyethyl methacrylate) have ben investigated. All the hyperbranched polyester solutions exhibited Newtonian behavior...

  19. Radiation cured polyester compositions containing metal-properties

    NASA Astrophysics Data System (ADS)

    Szalińska, H.; Pietrzak, M.; Gonerski, A.

    The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them.

  20. Effects of glass scraps powder and glass fiber on mechanical properties of polyester composites

    NASA Astrophysics Data System (ADS)

    Sonsakul, K.; Boongsood, W.

    2017-11-01

    One concern in bus manufacturing is the high cost of glass fiber reinforced in polyester composites parts. The composites of glass fiber and polyester are low elongation and high strength, and glass scraps powder displays high hardness and good chemical compatibility with the polymer matrix and glass fiber. This research aimed to study the effects of glass scraps powder and glass fiber on mechanical performance of polyester composites. Glass fiber was randomly oriented fiber and used as new. Glass scraps were obtained from a bus factory and crushed to powder sizes of 120 and 240 μm by a ball mill. Polyester composites were prepared using Vacuum Infusion Process (VIP).Polyester reinforced with 3 layers of glass fiber was an initial condition. Then, one layer of glass fiber was replaced with glass scraps powder. Flexural strength, tensile strength, impact strength and hardness of the polyester composites were determined. Hardness was increased with a combination of smaller size and higher volume of glass scraps powder. Pictures of specimens obtained by using scanning electron microscope (SEM) confirmed that the powder of glass scraps packed in the layers of glass fiber in polyester composites.

  1. Inexpensive, renewable substrates for the fermentative biosynthesis of bacterial poly(hydroxyalkanoate)s with controlled monomeric compositions

    USDA-ARS?s Scientific Manuscript database

    Poly(hydroxyalkanoate)s (PHA’s) are well-known bacterial polyesters produced by many bacteria under nutrient-deficient conditions. While many PHA’s demonstrate comparable properties to the more popular petrochemical polymers, PHA applications are inhibited by high production costs. In an effort to r...

  2. Pressure polymerization of polyester

    DOEpatents

    Maurer, Charles J.; Shaw, Gordon; Smith, Vicky S.; Buelow, Steven J.; Tumas, William; Contreras, Veronica; Martinez, Ronald J.

    2000-08-29

    A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about 220.degree. C. to about 320.degree. C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

  3. Thermal Degradation Mechanism of a Thermostable Polyester Stabilized with an Open-Cage Oligomeric Silsesquioxane

    PubMed Central

    Gozalbo, Ana; Mestre, Sergio; Sanz, Vicente

    2017-01-01

    A polyester composite was prepared through the polymerization of an unsaturated ester resin with styrene and an open-cage oligomeric silsesquioxane with methacrylate groups. The effect of the open-cage oligomeric silsesquioxane on the thermal stability of the thermostable polyester was studied using both thermogravimetric analysis and differential thermal analysis. The results showed that the methacryl oligomeric silsesquioxane improved the thermal stability of the polyester. The decomposition mechanism of the polyester/oligomer silsesquioxane composite was proposed by Fourier transform infrared spectroscopy (FTIR) analysis of the volatiles. PMID:29295542

  4. Microfabricated polyester conical microwells for cell culture applications†

    PubMed Central

    Selimović, Šeila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto

    2012-01-01

    Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required. PMID:21614380

  5. Concepts and tools to exploit the potential of bacterial inclusion bodies in protein science and biotechnology.

    PubMed

    Gatti-Lafranconi, Pietro; Natalello, Antonino; Ami, Diletta; Doglia, Silvia Maria; Lotti, Marina

    2011-07-01

    Cells have evolved complex and overlapping mechanisms to protect their proteins from aggregation. However, several reasons can cause the failure of such defences, among them mutations, stress conditions and high rates of protein synthesis, all common consequences of heterologous protein production. As a result, in the bacterial cytoplasm several recombinant proteins aggregate as insoluble inclusion bodies. The recent discovery that aggregated proteins can retain native-like conformation and biological activity has opened the way for a dramatic change in the means by which intracellular aggregation is approached and exploited. This paper summarizes recent studies towards the direct use of inclusion bodies in biotechnology and for the detection of bottlenecks in the folding pathways of specific proteins. We also review the major biophysical methods available for revealing fine structural details of aggregated proteins and which information can be obtained through these techniques. © 2011 The Authors Journal compilation © 2011 FEBS.

  6. 75 FR 47795 - Certain Polyester Staple Fiber from Korea: Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... Polyester staple fiber (``PSF'') covered by the scope of the order is defined as synthetic staple fibers, not carded, combed or otherwise processed for spinning, of polyesters measuring 3.3 decitex (3 denier...

  7. 75 FR 4044 - Polyester Staple Fiber From Taiwan: Initiation and Preliminary Results of Changed-Circumstances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... Commerce is initiating a changed- circumstances review of the antidumping duty order on polyester staple... previously accorded to Far Eastern Textile Limited with regard to the antidumping duty order on polyester...

  8. 76 FR 52935 - Certain Polyester Staple Fiber From Korea: Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-24

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... on polyester staple fiber from Korea. See Antidumping or Countervailing Duty Order, Finding, or..., 76 FR 37781 (June 28, 2011). Scope of the Order Polyester staple fiber covered by the scope of the...

  9. Liquefaction of corn stover and preparation of polyester from the liquefied polyol.

    PubMed

    Yu, Fei; Liu, Yuhuan; Pan, Xuejun; Lin, Xiangyang; Liu, Chengmei; Chen, Paul; Ruan, Roger

    2006-01-01

    This research investigated a novel process to prepare polyester from corn stover through liquefaction and crosslinking processes. First, corn stover was liquefied in organic solvents (90 wt% ethylene glycol and 10 wt% ethylene carbonate) with catalysts at moderate temperature under atmospheric pressure. The effect of liquefaction temperature, biomass content, and type of catalyst, such as H2SO4, HCl, H3PO4, and ZnCl2, was evaluated. Higher liquefaction yield was achieved in 2 wt% sulfuric acid, 1/4 (w/w) stover to liquefying reagent ratio; 160 degrees C temperature, in 2 h. The liquefied corn stover was rich in polyols, which can be directly used as feedstock for making polymers without further separation or purification. Second, polyester was made from the liquefied corn stover by crosslinking with multifunctional carboxylic acids and/or cyclic acid anhydrides. The tensile strength of polyester is about 5 MPa and the elongation is around 35%. The polyester is stable in cold water and organic solvents and readily biodegradable as indicated by 82% weight loss when buried in damp soil for 10 mo. The results indicate that this novel polyester could be used for the biodegradable garden mulch film production.

  10. 75 FR 39208 - Polyester Staple Fiber from Taiwan: Final Results of Changed-Circumstances Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-08

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber from... Eastern Textile Limited with regard to the antidumping duty order on polyester staple fiber from Taiwan... on polyester staple fiber from Taiwan to determine whether FENC was the successor-in-interest to FET...

  11. [Analysis of anatomical pieces preservation with polyester resin for human anatomy study].

    PubMed

    de Oliveira, Ítalo Martins; Mindêllo, Marcela Maria Aguiar; Martins, Yasmin de Oliveira; da Silva Filho, Antônio Ribeiro

    2013-01-01

    To evaluate the use of polyester resin in preserving anatomical specimens for the study of human anatomy. We used 150 anatomical specimens, comprised of unfixed (fresh), fixed in 10% formalin and vascular casts of organs injected with vinyl acetate and polyester resin. The solution used consisted of polyester resin with the diluent styrene monomer and catalyst (peroxol). After embedding in this solution, models in transparent resin were obtained, allowing full observation of structures and conservation of the specimens used. upon evaluation of the specimens, we observed a high degree of transparency, which promoted a complete visualization of structures with perfect preservation of the anatomy. The average time for the completion of the embedding was 48 hours. Only 14 specimens (9.3%) were lost during the preparation. Polyester resin can be used for preserving anatomical specimens for teaching human anatomy in a practical, aesthetic and durable way.

  12. 77 FR 6783 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... polyester staple fiber from the PRC. See Initiation of Antidumping and Countervailing Duty Administrative...

  13. Hydrolyzable polyester resins, varnishes and coating compositions containing the same

    DOEpatents

    Yamamori, Naoki; Yokoi, Junji; Yoshikawa, Motoyoshi

    1984-01-01

    Preparation of hydrolyzable polyester resin comprising reacting polycarboxylic acid and polyhydric alcohol components, which is characterized by using, as at least part of said polyhydric alcohol component, a metallic salt of hydroxy carboxylic acid of the formula defined and effecting the polycondensation at a temperature which is no more than the decomposition temperature of said metallic salt. The polyester resins are useful as resinous vehicle of varnishes and antifouling paints.

  14. Characterization of Polyester Matrix Reinforced with Banana Fibers Thermal Properties by Photoacoustic Technique

    NASA Astrophysics Data System (ADS)

    de Assis, Foluke S.; Netto, Pedro A.; Margem, Frederico M.; Monteiro, Artur R. P. Junior Sergio N.

    Synthetic fibers are being replaced gradually by natural materials such as lignocellulosic fibers. Compared to synthetic fibers, natural fibers have shown advantages in technical aspects such as environmental and economic. So there is a growing international interest in the use of those fibers. The banana fiber presents significant properties to be studied, but until now few thermal properties on banana fiber as reinforcement of polyester matrix were performed. The present work had as its objective to investigate, by photoacoustic spectroscopy and photothermal techniques the thermal properties of diffusivity, specific heat capacity and conductivity for polyester composites reinforced with banana fibers. In the polyester matrix will be added up to 30% in volume of continuous and aligned banana fibers. These values show that the incorporation of banana fibers in the polyester matrix changes its thermal properties.

  15. 75 FR 30373 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...

  16. 78 FR 38938 - Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review; 2011...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... duty order on polyester staple fiber (PSF) from Taiwan. The period of review is May 1, 2011, through... Results. None were received. \\1\\ See Polyester Staple Fiber From Taiwan: Preliminary Results of...

  17. 75 FR 6352 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...

  18. 77 FR 62217 - Certain Polyester Staple Fiber From the People's Republic of China: Continuation of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-12

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... International Trade Commission (``ITC'') that revocation of the antidumping duty order on certain polyester... antidumping duty order on certain polyester staple fiber from the PRC pursuant to section 751(c)(2) of the...

  19. 76 FR 7532 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... initiation of the administrative review of the antidumping duty order on certain polyester staple fiber from...

  20. 77 FR 19619 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... polyester staple fiber from the PRC.\\1\\ On February 9, 2012 the Department partially extended the deadline...

  1. 76 FR 37830 - Polyester Staple Fiber From Korea and Taiwan; Scheduling of Expedited Five-Year Reviews...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 731-TA-825 and 826 (Second Review)] Polyester... Duty Orders on Polyester Staple Fiber From Korea and Taiwan AGENCY: United States International Trade... determine whether revocation of the antidumping duty orders on polyester staple fiber from Korea and Taiwan...

  2. Static properties and moisture content properties of polyester fabrics modified by plasma treatment and chemical finishing

    NASA Astrophysics Data System (ADS)

    Kan, C. W.; Yuen, C. W. M.

    2008-01-01

    Low temperature plasma treatment has been conducted in textile industry and has some success in the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve the anti-static property of polyester fabric. The polyester fabrics were treated under different conditions using low temperature plasma. An Orthogonal Array Testing Strategy was employed to determine the optimum treatment condition. After low temperature plasma treatment, the polyester fabrics were evaluated with different characterisation methods. Under the observation of scanning electron microscope, the surface structure of low temperature plasma-treated polyester fabric was seriously altered. This provided more capacity for polyester to capture moisture and hence increase the dissipation of static charges. The relationship between moisture content and half-life decay time for static charges was studied and the results showed that the increment of moisture content would result in shortening the time for the dissipation of static charges. Moreover, there was a great improvement in the anti-static property of the low temperature plasma-treated polyester fabric after comparing with that of the polyester fabric treated with commercial anti-static finishing agent.

  3. 75 FR 51442 - Polyester Staple Fiber from Taiwan: Rescission of Antidumping Duty Administrative Review in Part

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber from... antidumping duty order on polyester staple fiber from Taiwan. The period of review is May 1, 2009, through... duty order on polyester staple fiber from Taiwan with respect to respondents Nan Ya Plastics...

  4. Optical properties of three-dimensional P(St-MAA) photonic crystals on polyester fabrics

    NASA Astrophysics Data System (ADS)

    Liu, Guojin; Zhou, Lan; Wu, Yujiang; Wang, Cuicui; Fan, Qinguo; Shao, Jianzhong

    2015-04-01

    The three-dimensional (3D) photonic crystals with face-centered cubic (fcc) structure was fabricated on polyester fabrics, a kind of soft textile materials quite different from the conventional solid substrates, by gravitational sedimentation self-assembly of monodisperse P(St-MAA) colloidal microspheres. The optical properties of structural colors on polyester fabrics were investigated and the position of photonic band gap was characterized. The results showed that the color-tuning ways of the structural colors from photonic crystals were in accordance with Bragg's law and could be modulated by the size of P(St-MAA) colloidal microspheres and the viewing angles. The L∗a∗b∗ values of the structural colors generated from the assembled polyester fabrics were in agreement with their reflectance spectra. The photonic band gap position of photonic crystals on polyester fabrics could be consistently confirmed by reflectance and transmittance spectra.

  5. 3D printing of new biobased unsaturated polyesters by microstereo-thermallithography.

    PubMed

    Gonçalves, Filipa A M M; Costa, Cátia S M F; Fabela, Inês G P; Farinha, Dina; Faneca, Henrique; Simões, Pedro N; Serra, Arménio C; Bártolo, Paulo J; Coelho, Jorge F J

    2014-09-01

    New micro three-dimensional (3D) scaffolds using biobased unsaturated polyesters (UPs) were prepared by microstereo-thermal-lithography (μSTLG). This advanced processing technique offers indubitable advantages over traditional printing methods. The accuracy and roughness of the 3D structures were evaluated by scanning electron microscopy and infinite focus microscopy, revealing a suitable roughness for cell attachment. UPs were synthesized by bulk polycondensation between biobased aliphatic diacids (succinic, adipic and sebacic acid) and two different glycols (propylene glycol and diethylene glycol) using fumaric acid as the source of double bonds. The chemical structures of the new oligomers were confirmed by proton nuclear magnetic resonance spectra, attenuated total reflectance Fourier transform infrared spectroscopy and matrix assisted laser desorption/ionization-time of flight mass spectrometry. The thermal and mechanical properties of the UPs were evaluated to determine the influence of the diacid/glycol ratio and the type of diacid in the polyester's properties. In addition an extensive thermal characterization of the polyesters is reported. The data presented in this work opens the possibility for the use of biobased polyesters in additive manufacturing technologies as a route to prepare biodegradable tailor made scaffolds that have potential applications in a tissue engineering area.

  6. A high-throughput assay for enzymatic polyester hydrolysis activity by fluorimetric detection.

    PubMed

    Wei, Ren; Oeser, Thorsten; Billig, Susan; Zimmermann, Wolfgang

    2012-12-01

    A fluorimetric assay for the fast determination of the activity of polyester-hydrolyzing enzymes in a large number of samples has been developed. Terephthalic acid (TPA) is a main product of the enzymatic hydrolysis of polyethylene terephthalate (PET), a synthetic polyester. Terephthalate has been quantified following its conversion to the fluorescent 2-hydroxyterephthalate by an iron autoxidation-mediated generation of free hydroxyl radicals. The assay proved to be robust at different buffer concentrations, reaction times, pH values, and in the presence of proteins. A validation of the assay was performed by analyzing TPA formation from PET films and nanoparticles catalyzed by a polyester hydrolase from Thermobifida fusca KW3 in a 96-well microplate format. The results showed a close correlation (R(2) = 0.99) with those obtained by a considerably more tedious and time-consuming HPLC method, suggesting the aptness of the fluorimetric assay for a high-throughput screening for polyester hydrolases. The method described in this paper will facilitate the detection and development of biocatalysts for the modification and degradation of synthetic polymers. The fluorimetric assay can be used to quantify the amount of TPA obtained as the final degradation product of the enzymatic hydrolysis of PET. In a microplate format, this assay can be applied for the high-throughput screening of polyester hydrolases. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 76 FR 2886 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results and Partial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... duty order on certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC''). See Certain Polyester Staple Fiber From the People's Republic of China: Notice of Preliminary Results...

  8. 75 FR 34097 - Certain Polyester Staple Fiber From Taiwan: Extension of the Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan. See Certain Polyester Staple Fiber from Taiwan: Preliminary Results of Antidumping Duty Administrative Review, 75 FR...

  9. 75 FR 38463 - Greige Polyester Cotton Printcloth From the People's Republic of China: Final Results of Sunset...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-101] Greige Polyester Cotton... duty order on greige polyester cotton printcloth from the People's Republic of China (``PRC''). Because..., 1983, the Department issued an antidumping duty order on greige polyester cotton printcloth from the...

  10. Polyester: simulating RNA-seq datasets with differential transcript expression.

    PubMed

    Frazee, Alyssa C; Jaffe, Andrew E; Langmead, Ben; Leek, Jeffrey T

    2015-09-01

    Statistical methods development for differential expression analysis of RNA sequencing (RNA-seq) requires software tools to assess accuracy and error rate control. Since true differential expression status is often unknown in experimental datasets, artificially constructed datasets must be utilized, either by generating costly spike-in experiments or by simulating RNA-seq data. Polyester is an R package designed to simulate RNA-seq data, beginning with an experimental design and ending with collections of RNA-seq reads. Its main advantage is the ability to simulate reads indicating isoform-level differential expression across biological replicates for a variety of experimental designs. Data generated by Polyester is a reasonable approximation to real RNA-seq data and standard differential expression workflows can recover differential expression set in the simulation by the user. Polyester is freely available from Bioconductor (http://bioconductor.org/). jtleek@gmail.com Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. 77 FR 21733 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... Department) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1, 2010, through April 30, 2011.\\1\\ In Certain Polyester Staple...

  12. 78 FR 38939 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... Preliminary Results of the 2011-2012 administrative review of the antidumping duty order on certain polyester... dumping margin is listed in the ``Final Results of Review'' section below. \\1\\ See Certain Polyester...

  13. 76 FR 28420 - Certain Polyester Staple Fiber From the People's Republic of China: Full Extension of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...

  14. The axial crushes behaviour on foam-filled round Jute/Polyester composite tubes

    NASA Astrophysics Data System (ADS)

    Othman, A.; Ismail, A. E.

    2018-04-01

    The present paper investigates the effect of axial loading compression on jute fibre reinforced polyester composite round tubes. The specimen of composite tube was fabricated by hand lay-up method of 120 mm length with fix 50.8 mm inner diameter to determine the behaviour of energy absorption on number of layers of 450 angle fibre and internally reinforced with and without foam filler material. The foam filler material used in this studies were polyurethane (PU) and polystyrene (PE) with average of 40 and 45 kg/m3 densities on the axial crushing load against displacement relations and on the failure modes. The number of layers of on this study were two; three and four were selected to calculate the crush force efficiency (CFE) and the specific energy absorption (SEA) of the composite tubes. Result indicated that the four layers’ jute/polyester show significant value in term of crushing load compared to 2 and 3 layers higher 60% for 2 layer and 3% compared to 3 layers. It has been found that the specific energy absorption of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 10% to 12% than empty and polyurethane (PU) foam tubes. The increase in the number of layers from two to four increases the mean axial load from 1.01 KN to 3.60 KN for empty jute/polyester and from 2.11 KN to 4.26 KN for the polyurethane (PU) foam-filled jute/polyester tubes as well as for 3.60 KN to 5.58 KN for the polystyrene (PE) foam-filled jute/polyester. The author’s found that the failure of mechanism influence the characteristic of curve load against displacement obtained and conclude that an increasing number of layers and introduce filler material enhance the capability of specific absorbed energy.

  15. Mechanical performance of hybrid polyester composites reinforced Cloisite 30B and kenaf fibre

    NASA Astrophysics Data System (ADS)

    Bonnia, N. N.; Surip, S. N.; Ratim, S.; Mahat, M. M.

    2012-06-01

    Hybridization of rubber toughened polyester-kenaf nanocomposite was prepared by adding various percentage of kenaf fiber with 4% Cloisite 30B in unsaturated polyester resin. Composite were prepared by adding filler to modified polyester resin subsequently cross-linked using methyl ethyl ketone peroxide and the accelerator cobalt octanoate 1%. Three per hundred rubbers (phr) of liquid natural rubber (LNR) were added in producing this composite. This composite expected to be applied in the interior of passenger cars and truck cabins. This is a quality local product from a combination of good properties polyester and high performance natural fiber, kenaf that is suitable for many applications such as in automotive sector and construction sector. The mechanical and thermal properties of composite were characterized using Durometer Shore-D hardness test, Izod impact test, Scanning electron microscopy, thermogravimetry (TGA) and differential scanning calorimetry (DSC). Result shows that addition of LNR give good properties on impact, flexural and hardness compare to without LNR composite. DSC curve shows that all composition of composites is fully cured and good in thermal properties. Addition of higher percentage of kenaf will lead the composite to elastic behavior and decrease the toughened properties of the composite. Hybrid system composite showed the flexural properties within the flexural properties of kenaf - polyester and Cloisite 30B.

  16. 76 FR 60802 - Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Continuation of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839, A-583-833] Certain Polyester... Commission (ITC) that revocation of the antidumping duty orders on certain polyester staple fiber from the... and the ITC instituted sunset reviews of the antidumping duty orders on polyester staple fiber from...

  17. Fiber Reinforced Polyester Resins Polymerized by Microwave Source

    NASA Astrophysics Data System (ADS)

    Visco, A. M.; Calabrese, L.; Cianciafara, P.; Bonaccorsi, L.; Proverbio, E.

    2007-12-01

    Polyester resin based composite materials are widely used in the manufacture of fiberglass boats. Production time of fiberglass laminate components could be strongly reduced by using an intense energy source as well as microwaves. In this work a polyester resin was used with 2% by weight of catalyst and reinforced with chopped or woven glass fabric. Pure resin and composite samples were cured by microwaves exposition for different radiation times. A three point bending test was performed on all the cured samples by using an universal testing machine and the resulting fracture surfaces were observed by means of scanning electron microscopy (SEM). The results of mechanical and microscopy analyses evidenced that microwave activation lowers curing time of the composite while good mechanical properties were retained. Microwaves exposition time is crucial for mechanical performance of the composite. It was evidenced that short exposition times suffice for resin activation while long exposure times cause fast cross linking and premature matrix fracture. Furthermore high-radiation times induce bubbles growth or defects nucleation within the sample, decreasing composite performance. On the basis of such results microwave curing activation of polyester resin based composites could be proposed as a valid alternative method for faster processing of laminated materials employed for large-scale applications.

  18. Semi-aromatic polyesters based on a carbohydrate-derived rigid diol for engineering plastics.

    PubMed

    Wu, Jing; Eduard, Pieter; Thiyagarajan, Shanmugam; Noordover, Bart A J; van Es, Daan S; Koning, Cor E

    2015-01-01

    New carbohydrate-based polyesters were prepared from isoidide-2,5-dimethanol (extended isoidide, XII) through melt polymerization with dimethyl esters of terephthalic acid (TA) and furan-2,5-dicarboxylic acid (FDCA), yielding semi-crystalline prepolymers. Subsequent solid-state post-condensation (SSPC) gave high molecular weight (Mn =30 kg mol(-1) for FDCA) materials, the first examples of high Mn , semi-aromatic homopolyesters containing isohexide derivatives obtained via industrially relevant procedures. NMR spectroscopy showed that the stereo-configuration of XII was preserved under the applied conditions. The polyesters are thermally stable up to 380 °C. The TA- and FDCA-based polyesters have high Tg (105 °C and 94 °C, resp.) and Tm (284 °C and 250 °C, resp.) values. Its reactivity, stability, and ability to afford high Tg and Tm polyesters make XII a promising diol for the synthesis of engineering polymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A study on effect of ATH on Euphorbia coagulum modified polyester banana fiber composite

    NASA Astrophysics Data System (ADS)

    Kumari, Sanju; Rai, Bhuvneshwar; Kumar, Gulshan

    2018-02-01

    Fiber reinforced polymer composites are used for building and structural applications due to their high strength. In conventional composites both the binder and the reinforcing fibers are synthetic or either one of the material is natural. In the present study coagulum of Euphorbia royleana has been used for replacing polyester resinas binder in polyester banana composite. Euphorbia coagulum (driedlatex) is rich in resinous mass (60-80%), which are terpenes and polyisoprene (10-20%). Effect of varying percentage of coagulum content on various physico-mechanical properties of polyester-banana composites has been studied. Since banana fiber is sensitive to water due to presence of polar group, banana composite undergoes delamination and deterioration under humid condition. Alkali treated banana fiber along with coagulum content has improved overall mechanical properties and reduction in water absorption. The best physico-mechanical properties have been achieved on replacing 40% of polyester resin by coagulum. An increase of 50% in bending strength, 30% bending modulus and 45% impact strength as well as 68% decrease in water absorption was observed. Incorporation of 20% ATH as flame retardant in coagulum modified banana polyester composite enhanced limiting oxygen index from 20.6 to 26.8% and smoke density reduced up to 40%. This study presents the possibility of utilization of renewable materials for environmental friendly composite development as well as to find out alternative feedstock for petroleum products. Developed Euphorbia latex modified banana polyester composites can have potential utility in hardboard, partition panel, plywood and automotive etc.

  20. Dipeptide-based polyphosphazene and polyester blends for bone tissue engineering.

    PubMed

    Deng, Meng; Nair, Lakshmi S; Nukavarapu, Syam P; Jiang, Tao; Kanner, William A; Li, Xudong; Kumbar, Sangamesh G; Weikel, Arlin L; Krogman, Nicholas R; Allcock, Harry R; Laurencin, Cato T

    2010-06-01

    Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)(1)(phenyl phenoxy)(1)phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2

  1. Dipeptide-based Polyphosphazene and Polyester Blends for Bone Tissue Engineering

    PubMed Central

    Deng, Meng; Nair, Lakshmi S.; Nukavarapu, Syam P.; Jiang, Tao; Kanner, William A.; Li, Xudong; Kumbar, Sangamesh G.; Weikel, Arlin L.; Krogman, Nicholas R.; Allcock, Harry R.; Laurencin, Cato T.

    2010-01-01

    Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)1(phenyl phenoxy)1phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2 < Matrix1 < PLAGA in phosphate buffered saline at 37°C over 12 weeks. Significantly higher pH values of degradation media were observed for blends compared to PLAGA confirming the neutralization of PLAGA acidic degradation by polyphosphazene hydrolysis products. The blend components PLAGA and polyphosphazene exhibited a similar degradation pattern as characterized by the molecular weight loss. Furthermore, blends demonstrated significantly higher osteoblast growth rates compared to PLAGA while maintaining osteoblast phenotype over a 21-day culture. Both blends demonstrated improved biocompatibility in a rat subcutaneous implantation model compared to PLAGA over 12 weeks. PMID:20334909

  2. Sugar-based bicyclic monomers for aliphatic polyesters: a comparative appraisal of acetalized alditols and isosorbide

    PubMed Central

    Zakharova, Elena; Martínez de Ilarduya, Antxon; León, Salvador; Muñoz-Guerra, Sebastián

    2017-01-01

    Abstract Three series of polyalkanoates (adipates, suberates and sebacates) were synthesized using as monomers three sugar-based bicyclic diols derived from D-glucose (Glux-diol and isosorbide) and D-mannose (Manx-diol). Polycondensations were conducted in the melt applying similar reaction conditions for all cases. The aim was to compare the three bicyclic diols regarding their suitability to render aliphatic polyesters with enhanced thermal and mechanical properties. The ensuing polyesters had molecular weights (M w) in the 25,000–50,000 g mol−1 range with highest values being attained for Glux-diol. All the polyesters started to decompose above 300 °C and most of them did not display perceivable crystallinity. On the contrary, they had glass transition temperatures much higher than usually found in homologous polyesters made of alkanediols, and showed a stress–strain behavior consistent with their T g values. Glux-diol was particularly effective in increasing the T g and to render therefore polyesters with high elastic modulus and considerable mechanical strength. PMID:29491789

  3. 75 FR 76954 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Time Limit for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... administrative review of certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC''), covering the period June 1, 2008--May 31, 2009. See Certain Polyester Staple Fiber From the People's...

  4. Kenaf-glass fiber reinforced unsaturated polyester hybrid composites: Tensile properties

    NASA Astrophysics Data System (ADS)

    Zhafer, S. F.; Rozyanty, A. R.; Shahnaz, S. B. S.; Musa, L.; Zuliahani, A.

    2016-07-01

    The use of natural fibers in composite is rising in recent years due their lightweight, non-abrasive, combustible, non-toxic, low cost and biodegradable properties. However, in comparison with synthetic fibers, the mechanical properties of natural fibers are lower. Therefore, the inclusion of synthetic fibers could improve the mechanical performance of natural fiber based composites. In this study, kenaf bast fiber and glass fiber at different weight percentage loading were used as reinforcement to produce hybrid composites. Unsaturated polyester (UP) resin was used as matrix and hand lay-up process was performed to apply the UP resin on the hybrid kenaf bast/glass fiber composite. Effect of different fiber loading on tensile strength, tensile modulus and elongation at break of the hybrid composite was studied. It has been found that the highest value of tensile strength and modulus was achieved at 10 wt.% kenaf/10 wt.% glass fiber loading. It was concluded that addition of glass fiber has improved the tensile properties of kenaf bast fiber based UP composites.

  5. Preparation and properties of high storage stability polyester polyol dispersion for two-component waterborne polyurethane coating

    NASA Astrophysics Data System (ADS)

    Hao, H.; Hu, J. Q.; Wang, F.; Tu, W. P.

    2017-01-01

    A new type of polyester polyol dispersion with good storage stability was prepared based on a hydrophilic monomer 5-sodium sulfodimethyl isophthalate (5-SIPM), and frequently-used monomers such as neopentyl glycol (NPG), dimethyl terephthalate (DMT), dimethyl phthalate (DMP) and trimethylolpropane (TMP) by the transpolycondensation and polycondensation method. The polyester polyol dispersion was characterized by FTIR and GPC. The proper content of these monomers were determined by the performance of polyester dispersion: the content of TMP was 15wt%, the content of NPG was 7.5wt% and the hydrophilic monomer 5-SIPM content was 5wt%. Two-component waterborne polyurethane (2K-WPU) coatings were prepared by Bayhydur® XP2487/1 and polyester polyol dispersions, which were stored before and after at 40 ° for 6 weeks, the prepared films have no differences in drying time, adhesion, pencil hardness, gloss and chemical resistance, the result also reveals that the polyester polyol dispersion have excellent storage stability resistance.

  6. The identification of cutin synthase: formation of the plant polyester cutin.

    PubMed

    Yeats, Trevor H; Martin, Laetitia B B; Viart, Hélène M-F; Isaacson, Tal; He, Yonghua; Zhao, Lingxia; Matas, Antonio J; Buda, Gregory J; Domozych, David S; Clausen, Mads H; Rose, Jocelyn K C

    2012-07-01

    A hydrophobic cuticle consisting of waxes and the polyester cutin covers the aerial epidermis of all land plants, providing essential protection from desiccation and other stresses. We have determined the enzymatic basis of cutin polymerization through characterization of a tomato extracellular acyltransferase, CD1, and its substrate, 2-mono(10,16-dihydroxyhexadecanoyl)glycerol. CD1 has in vitro polyester synthesis activity and is required for cutin accumulation in vivo, indicating that it is a cutin synthase.

  7. The identification of cutin synthase: formation of the plant polyester cutin

    PubMed Central

    Yeats, Trevor H.; Martin, Laetitia B. B.; Viart, Hélène M.-F.; Isaacson, Tal; He, Yonghua; Zhao, Lingxia; Matas, Antonio J.; Buda, Gregory J.; Domozych, David S.; Clausen, Mads H.; Rose, Jocelyn K. C.

    2012-01-01

    A hydrophobic cuticle consisting of waxes and the polyester cutin covers the aerial epidermis of all land plants, providing essential protection from desiccation and other stresses. We have determined the enzymatic basis of cutin polymerization through characterization of a tomato extracellular acyltransferase, CD1, and its substrate, 2-mono(10,16-dihydroxyhexadecanoyl)glycerol (2-MHG). CD1 has in vitro polyester synthesis activity and is required for cutin accumulation in vivo, indicating that it is a cutin synthase. PMID:22610035

  8. Effect of structural parameters on burning behavior of polyester fabrics having flame retardancy property

    NASA Astrophysics Data System (ADS)

    Çeven, E. K.; Günaydın, G. K.

    2017-10-01

    The aim of this study is filling the gap in the literature about investigating the effect of yarn and fabric structural parameters on burning behavior of polyester fabrics. According to the experimental design three different fabric types, three different weft densities and two different weave types were selected and a total of eighteen different polyester drapery fabrics were produced. All statistical procedures were conducted using the SPSS Statistical software package. The results of the Analysis of Variance (ANOVA) tests indicated that; there were statistically significant (5% significance level) differences between the mass loss ratios (%) in weft and mass loss ratios (%) in warp direction of different fabrics calculated after the flammability test. The Student-Newman-Keuls (SNK) results for mass loss ratios (%) both in weft and warp directions revealed that the mass loss ratios (%) of fabrics containing Trevira CS type polyester were lower than the mass loss ratios of polyester fabrics subjected to washing treatment and flame retardancy treatment.

  9. Precision Aliphatic Polyesters with Alternating Microstructures via Cross-Metathesis Polymerization: An Event of Sequence Control.

    PubMed

    Li, Zi-Long; Zeng, Fu-Rong; Ma, Ji-Mei; Sun, Lin-Hao; Zeng, Zhen; Jiang, Hong

    2017-06-01

    Sequence-regulated polymerization is realized upon sequential cross-metathesis polymerization (CMP) and exhaustive hydrogenation to afford precision aliphatic polyesters with alternating sequences. This strategy is particularly suitable for the arrangement of well-known monomer units including glycolic acid, lactic acid, and caprolactic acid on polymer chain in a predetermined sequence. First of all, structurally asymmetric monomers bearing acrylate and α-olefin terminuses are generated in an efficient and straightforward fashion. Subsequently, cross-metathesis (co)polymerization of M1 and M2 using the Hoveyda-Grubbs second-generation catalyst (HG-II) furnishes P1-P3, respectively. Finally, hydrogenation yields the desired saturated polyesters HP1-HP3. It is noteworthy that the ε-caprolactone-derived unit is generated in situ rather than introduced to tailor-made monomers prior to CMP. NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) results verify the microstructural periodicity of these precision polyesters. Differential scanning calorimetry (DSC) results reflect that polyesters without methyl side groups exhibit crystallinity, and unsaturated polyester samples show higher glass transition temperatures than their hydrogenated counterparts owing to structural rigidity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Polyester Fabric's Fluorescent Dyeing in Supercritical Carbon Dioxide and its Fluorescence Imaging.

    PubMed

    Xiong, Xiaoqing; Xu, Yanyan; Zheng, Laijiu; Yan, Jun; Zhao, Hongjuan; Zhang, Juan; Sun, Yanfeng

    2017-03-01

    As one of the most important coumarin-like dyes, disperse fluorescent Yellow 82 exhibits exceptionally large two-photon effects. Here, it was firstly introduced into the supercritical CO 2 dyeing polyester fabrics in this work. Results of the present work showed that the dyeing parameters such as the dyeing time, pressure and temperature had remarkable influences on the color strength of fabrics. The optimized dyeing condition in supercritical CO 2 dyeing has been proposed that the dyeing time was 60 min; the pressure was 25 MPa and the temperature was 120 °C. As a result, acceptable products were obtained with the wash and rub fastness rating at 5 or 4-5. The polyester fabrics dyed with fluorescent dyes can be satisfied for the requirement of manufacturing warning clothing. Importantly, the confocal microscopy imaging technology was successfully introduced into textile fields to observe the distribution and fluorescence intensity of disperse fluorescent Yellow 82 on polyester fabrics. As far as we know, this is the first report about supercritical CO 2 dyeing polyester fabrics based on disperse fluorescent dyes. It will be very helpful for the further design of new fluorescent functional dyes suitable for supercritical CO 2 dyeing technique.

  11. The effect of autoclave resterilisation on polyester vascular grafts.

    PubMed

    Riepe, G; Whiteley, M S; Wente, A; Rogge, A; Schröder, A; Galland, R B; Imig, H

    1999-11-01

    polyester grafts are expensive, single-use items. Some manufacturers of uncoated, woven grafts include instructions for autoclave resterilisation to be performed at the surgeon's own request. Others warn against such manipulation. Theoretically, the glass transition point of polyester at 70-80 degrees C and the possible acceleration of hydrolysis suggest that autoclave resterilisation at 135 degrees C might be a problem. a DeBakey Soft Woven Dacron Vascular Prosthesis (Bard) and a Woven Double Velour Dacron Graft (Meadox) were autoclave-resterilised 0 to 20 times, having been weighed before and after sterilisation. Tactile testing was performed. Mechanical properties were examined by probe puncture and single-filament testing, the surface was examined by scanning electron microscopy and the degree of hydrolysis by infra-red spectroscopy. tactile testing revealed a change of feeling with increasing cycles of resterilisation. Investigation of weight, textile strength, single-filament strength, electron microscopy of the surface and infra-red spectroscopy showed no change of the material. changes felt are presumably a surface phenomenon, not measurably affecting strength or chemistry of material after autoclave resterilisation. We therefore feel that it is safe to use once-autoclave-resterilised surplus uncoated polyester grafts, provided that sterility is guaranteed. Copyright 1999 Harcourt Publishers Ltd.

  12. Simulation on the Performance of a Driven Fan Made by Polyester/Epoxy interpenetrate polymer network (IPN)

    NASA Astrophysics Data System (ADS)

    Fahrul Hassan, Mohd; Jamri, Azmil; Nawawi, Azli; Zaini Yunos, Muhamad; Fauzi Ahmad, Md; Adzila, Sharifah; Nasrull Abdol Rahman, Mohd

    2017-08-01

    The main purpose of this study is to investigate the performance of a driven fan design made by Polyester/Epoxy interpenetrate polymer network (IPN) material that specifically used for turbocharger compressor. Polyester/Epoxy IPN is polymer plastics that was used as replacements for traditional polymers and has been widely used in a variety of applications because of their limitless conformations. Simulation based on several parameters which are air pressure, air velocity and air temperature have been carried out for a driven fan design performance of two different materials, aluminum alloy (existing driven fan design) and Polyester/Epoxy IPN using SolidWorks Flow Simulation software. Results from both simulations were analyzed and compared where both materials show similar performance in terms of air pressure and air velocity due to similar geometric and dimension, but Polyester/Epoxy IPN produces lower air temperature than aluminum alloy. This study shows a preliminary result of the potential Polyester/Epoxy IPN to be used as a driven fan design material. In the future, further studies will be conducted on detail simulation and experimental analysis.

  13. A new polyester based on allyl α-hydroxy glutarate as shell for magnetite nanoparticles

    NASA Astrophysics Data System (ADS)

    Nan, Alexandrina; Feher, Ioana Coralia

    2017-12-01

    Allyl side-chain-functionalized lactide was synthesized from commercially available glutamic acid and polymerized by ring opening polymerization using 4-dimethylaminopyridine as an organocatalyst in the presence of magnetic nanoparticles. The resulting magnetic nanostructures coated with the allyl-containing polyester were then functionalized with cysteine by thiol-ene click reaction leading to highly functionalized magnetic nano-platforms of practical interest. The polyester precursors were characterized by nuclear magnetic resonance and mass spectrometry. The morphology of magnetic nanostructures based on the functionalized polyester was determined by transmission electron microscopy TEM, while the chemical structure was investigated by FT-IR. TGA investigations and the magnetic properties of the magnetic nanostructures are also described.

  14. Experimental Investigation on Thermal Physical Properties of an Advanced Polyester Material

    NASA Astrophysics Data System (ADS)

    Guangfa, Gao; Shujie, Yuan; Ruiyuan, Huang; Yongchi, Li

    Polyester materials were applied widely in aircraft and space vehicles engineering. Aimed to an advanced polyester material, a series of experiments for thermal physical properties of this material were conducted, and the corresponding performance curves were obtained through statistic analyzing. The experimental results showed good consistency. And then the thermal physical parameters such as thermal expansion coefficient, engineering specific heat and sublimation heat were solved and calculated. This investigation provides an important foundation for the further research on the heat resistance and thermodynamic performance of this material.

  15. Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

    PubMed Central

    Rydz, Joanna; Sikorska, Wanda; Kyulavska, Mariya; Christova, Darinka

    2014-01-01

    This review focuses on the polyesters such as polylactide and polyhydroxyalkonoates, as well as polyamides produced from renewable resources, which are currently among the most promising (bio)degradable polymers. Synthetic pathways, favourable properties and utilisation (most important applications) of these attractive polymer families are outlined. Environmental impact and in particular (bio)degradation of aliphatic polyesters, polyamides and related copolymer structures are described in view of the potential applications in various fields. PMID:25551604

  16. Synthesis of amphiphilic alternating polyesters with oligo(ethylene glycol) side chains and potential use for sustained release drug delivery.

    PubMed

    Wang, Wei; Ding, Jianxun; Xiao, Chunsheng; Tang, Zhaohui; Li, Di; Chen, Jie; Zhuang, Xiuli; Chen, Xuesi

    2011-07-11

    Novel amphiphilic alternating polyesters, poly((N-phthaloyl-l-glutamic anhydride)-co-(2-(2-(2-methoxyethoxy)ethoxy)methyl)oxirane) (P(PGA-co-ME(2)MO)), were synthesized by alternating copolymerization of PGA and ME(2)MO. The structures of the synthesized polyesters were characterized by (1)H NMR, (13)C NMR, FT-IR, and GPC analyses. Because of the presence of oligo(ethylene glycol) (OEG) side chains, the polyesters could self-assemble into thermosensitive micelles. Dynamic light scattering (DLS) showed that these micelles underwent thermoinduced size decrease without intermicellar aggregation. In vitro methyl thiazolyl tetrazolium (MTT) assay demonstrated that the polyesters were biocompatible to Henrietta Lacks (HeLa) cells, rendering their potential for drug delivery applications. Two hydrophobic drugs, rifampin and doxorubicin (DOX), were loaded into the polyester micelles and observed to be released in a zero-order sustained manner. The sustained release could be accelerated in lower pH or in the presence of proteinase K, due to the degradation of the polyester under these conditions. Remarkably, in vitro cell experiments showed that the polyester micelles accomplished fast release of DOX inside cells and higher anticancer efficacy as compared with the free DOX. With enhanced stability during circulation condition and accelerated drug release at the target sites (e.g., low pH or enzyme presence), these novel polyesters with amphiphilic structures are promising to be used in sustained release drug delivery systems.

  17. Micro-thermal analysis of polyester coatings

    NASA Astrophysics Data System (ADS)

    Fischer, Hartmut R.

    2010-04-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure like chain scission and cross-linking are manifested by a shift of the LTA detectable Tg and by a change of the slope of the part of the LTA graph responsible for the penetration of the hot sensor into the material after passing the glass transition temperature. As such LTA is a valuable tool to have a quick look into coating surfaces and especially their ageing. The photo-degradation of polyester in air leads to the formation of a cross-linked network at a surface layer of about 3-4 μm coupled with an increase in hardness and of the glass transition temperature by ˜90 K, the effect is less drastic for a photo-degradation in a nitrogen environment. Moreover, the presence of a non-equilibrium dense surface layer with a higher Tg formed during the drying of the coating formulation and the film solidification can be shown.

  18. Study on Energy Absorption Capacity of Steel-Polyester Hybrid Fiber Reinforced Concrete Under Uni-axial Compression

    NASA Astrophysics Data System (ADS)

    Chella Gifta, C.; Prabavathy, S.

    2018-05-01

    This work presents the energy absorption capacity of hybrid fiber reinforced concrete made with hooked end steel fibers (0.5 and 0.75%) and straight polyester fibers (0.5, 0.8, 1.0 and 2.0%). Compressive toughness (energy absorption capacity) under uni-axial compression was evaluated on 100 × 200 mm size cylindrical specimens with varying steel and polyester fiber content. Efficiency of the hybrid fiber reinforcement is studied with respect to fiber type, size and volume fractions in this investigation. The vertical displacement under uni-axial compression was measured under the applied loads and the load-deformation curves were plotted. From these curves the toughness values were calculated and the results were compared with steel and polyester as individual fibers. The hybridization of 0.5% steel + 0.5% polyester performed well in post peak region due to the addition of polyester fibers with steel fibers and the energy absorption value was 23% greater than 0.5% steel FRC. Peak stress values were also higher in hybrid series than single fiber and based on the results it is concluded that hybrid fiber reinforcement improves the toughness characteristics of concrete without affecting workability.

  19. Design and fabrication of an E-shaped wearable textile antenna on PVB-coated hydrophobic polyester fabric

    NASA Astrophysics Data System (ADS)

    Babu Roshni, Satheesh; Jayakrishnan, M. P.; Mohanan, P.; Peethambharan Surendran, Kuzhichalil

    2017-10-01

    In this paper, we investigated the simulation and fabrication of an E-shaped microstrip patch antenna realized on multilayered polyester fabric suitable for WiMAX (Worldwide Interoperability for Microwave Access) applications. The main challenges while designing a textile antenna were to provide adequate thickness, surface uniformity and water wettability to the textile substrate. Here, three layers of polyester fabric were stacked together in order to obtain sufficient thickness, and were subsequently dip coated with polyvinyl butyral (PVB) solution. The PVB-coated polyester fabric showed a hydrophobic nature with a contact angle of 91°. The RMS roughness of the uncoated and PVB-coated polyester fabric was about 341 nm and 15 nm respectively. The promising properties, such as their flexibility, light weight and cost effectiveness, enable effortless integration of the proposed antenna into clothes like polyester jackets. Simulated and measured results in terms of return loss as well as gain were showcased to confirm the usefulness of the fabricated prototype. The fabricated antenna successfully operates at 3.37 GHz with a return loss of 21 dB and a maximum measured gain of 3.6 dB.

  20. Release of polyester and cotton fibers from textiles in machine washings.

    PubMed

    Sillanpää, Markus; Sainio, Pirjo

    2017-08-01

    Microplastics are widely spread in the environment, which along with still increasing production have aroused concern of their impacts on environmental health. The objective of this study is to quantify the number and mass of two most common textile fibers discharged from sequential machine washings to sewers. The number and mass of microfibers released from polyester and cotton textiles in the first wash varied in the range 2.1 × 10 5 to 1.3 × 10 7 and 0.12 to 0.33% w/w, respectively. Amounts of released microfibers showed a decreasing trend in sequential washes. The annual emission of polyester and cotton microfibers from household washing machines was estimated to be 154,000 (1.0 × 10 14 ) and 411,000 kg (4.9 × 10 14 ) in Finland (population 5.5 × 10 6 ). Due to the high emission values and sorption capacities, the polyester and cotton microfibers may play an important role in the transport and fate of chemical pollutants in the aquatic environment.

  1. Radioluminescence of polyester resin modified with acrylic acid and its salts

    NASA Astrophysics Data System (ADS)

    Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

  2. Antifungal activity of fabrics knitted by metalized Silver/Polyester composite yarn

    NASA Astrophysics Data System (ADS)

    Özkan, İ.; Duru Baykal, P.

    2017-10-01

    In this study, antifungal properties of fabric knitted from metalized silver/polyester composite yarn were investigated. Intermingling is an alternative technique for yarn blending process. Yarns having different features can be combined by feeding the same intermingling jet. This process is defined as commingling. In the study, intermingling process was used to produce metalized silver/polyester composite yarn. Commingled yarns were knitted to single jersey fabrics by IPM brand sample type circular knitting machine. Antifungal activity test was applied to samples against Aspergillus Niger according to AATCC 30 test procedure. It has been identified that the application provides antifungal activity to fabric.

  3. 77 FR 54562 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty Administrative Review AGENCY: Import... antidumping duty order on certain polyester staple fiber from the Republic of Korea (``the Order''). The...

  4. Mechanical Properties of Unsaturated Polyester / Montmorillonite Composites

    DTIC Science & Technology

    2001-11-01

    Montmorillonite Composites DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE: Nanophase and...Mechanical Properties of Unsaturated Polyester / Montmorillonite Composites A. Baran Inceoglu and Ulku Yilmazer Middle East Technical University, Chemical...analysed the nature of the curing agent on structure. Kornmann, Berglund and Giannelis [8] studied nanocomposites based on montmorillonite modified

  5. Protoenzymes: the case of hyperbranched polyesters

    NASA Astrophysics Data System (ADS)

    Mamajanov, Irena; Cody, George D.

    2017-11-01

    Enzymes are biopolymeric complexes that catalyse biochemical reactions and shape metabolic pathways. Enzymes usually work with small molecule cofactors that actively participate in reaction mechanisms and complex, usually globular, polymeric structures capable of specific substrate binding, encapsulation and orientation. Moreover, the globular structures of enzymes possess cavities with modulated microenvironments, facilitating the progression of reaction(s). The globular structure is ensured by long folded protein or RNA strands. Synthesis of such elaborate complexes has proven difficult under prebiotically plausible conditions. We explore here that catalysis may have been performed by alternative polymeric structures, namely hyperbranched polymers. Hyperbranched polymers are relatively complex structures that can be synthesized under prebiotically plausible conditions; their globular structure is ensured by virtue of their architecture rather than folding. In this study, we probe the ability of tertiary amine-bearing hyperbranched polyesters to form hydrophobic pockets as a reaction-promoting medium for the Kemp elimination reaction. Our results show that polyesters formed upon reaction between glycerol, triethanolamine and organic acid containing hydrophobic groups, i.e. adipic and methylsuccinic acid, are capable of increasing the rate of Kemp elimination by a factor of up to 3 over monomeric triethanolamine. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  6. Reactive modification of polyesters and their blends

    NASA Astrophysics Data System (ADS)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

  7. Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

    NASA Astrophysics Data System (ADS)

    Othman, A.; Ismail, AE

    2018-04-01

    Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

  8. Influence of nanosize clay platelets on the mechanical properties of glass fiber reinforced polyester composites.

    PubMed

    Jawahar, P; Balasubramanian, M

    2006-12-01

    Glass fiber reinforced polyester composite and hybrid nanoclay-fiber reinforced composites were prepared by hand lay-up process. The mechanical behavior of these materials and the changes as a result of the incorporation of both nanosize clay and glass fibers were investigated. Composites were prepared with a glass fibre content of 25 vol%. The proportion of the nanosize clay platelets was varied from 0.5 to 2.5 vol%. Hybrid clay-fiber reinforced polyester composite posses better tensile, flexural, impact, and barrier properties. Hybrid clay-fiber reinforced polyester composites also posses better shear strength, storage modulus, and glass transition temperature. The optimum properties were found to be with the hybrid laminates containing 1.5 vol% nanosize clay.

  9. The Effect of Structural Modifications on Ionic Conductivity in Newly-Designed Polyester Electrolytes

    NASA Astrophysics Data System (ADS)

    Pesko, Danielle; Jung, Yuki; Coates, Geoff; Balsara, Nitash

    2015-03-01

    Gaining a fundamental understanding of the relationship between molecular structure and ionic conductivity of polymer electrolytes is an essential step toward designing next generation materials for battery applications. In this study, we use a systematic set of newly-designed polyesters with varying side-chain lengths and oxygen functional groups to elucidate the effects of structural modifications on the conductive properties of the corresponding electrolytes. Mixtures of polyesters and lithium bis(trifluromethanesulfonyl)imide (LiTFSI) were characterized using ac impedance spectroscopy to measure the ionic conductivity at various temperatures and salt concentrations. The relative conductivities of these electrolytes in the dilute limit are directly comparable to results of molecular dynamics simulations performed using the same polymers. The simulations correspond well with the experimental results, and provide molecular level insight about the solvation environment of the lithium ions and how the ions transport through these polyesters.

  10. Non-destructive and fast identification of cotton-polyester blend fabrics by the portable near-infrared spectrometer.

    PubMed

    Li, Wen-xia; Li, Feng; Zhao, Guo-liang; Tang, Shi-jun; Liu, Xiao-ying

    2014-12-01

    A series of 376 cotton-polyester (PET) blend fabrics were studied by a portable near-infrared (NIR) spectrometer. A NIR semi-quantitative-qualitative calibration model was established by Partial Least Squares (PLS) method combined with qualitative identification coefficient. In this process, PLS method in a quantitative analysis was used as a correction method, and the qualitative identification coefficient was set by the content of cotton and polyester in blend fabrics. Cotton-polyester blend fabrics were identified qualitatively by the model and their relative contents were obtained quantitatively, the model can be used for semi-quantitative identification analysis. In the course of establishing the model, the noise and baseline drift of the spectra were eliminated by Savitzky-Golay(S-G) derivative. The influence of waveband selection and different pre-processing method was also studied in the qualitative calibration model. The major absorption bands of 100% cotton samples were in the 1400~1600 nm region, and the one for 100% polyester were around 1600~1800 nm, the absorption intensity was enhancing with the content increasing of cotton or polyester. Therefore, the cotton-polyester's major absorption region was selected as the base waveband, the optimal waveband (1100~2500 nm) was found by expanding the waveband in two directions (the correlation coefficient was 0.6, and wave-point number was 934). The validation samples were predicted by the calibration model, the results showed that the model evaluation parameters was optimum in the 1100~2500 nm region, and the combination of S-G derivative, multiplicative scatter correction (MSC) and mean centering was used as the pre-processing method. RC (relational coefficient of calibration) value was 0.978, RP (relational coefficient of prediction) value was 0.940, SEC (standard error of calibration) value was 1.264, SEP (standard error of prediction) value was 1.590, and the sample's recognition accuracy was up to 93

  11. 78 FR 14512 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Fiber From the People's Republic of China: Preliminary Results and Rescission in Part of the 2011-2012... administrative review of the antidumping duty order on certain polyester staple fiber from the People's Republic... Industries (``Far Eastern'') and Huvis Sichuan Chemical Fiber Corp. and Huvis Sichuan Polyester Fiber Ltd...

  12. 75 FR 70906 - Certain Polyester Staple Fiber From the People's Republic of China: Partial Rescission of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of China: Partial Rescission of the Third Antidumping Duty... Request Administrative Review'' of the antidumping duty order on certain polyester staple fiber (``PSF...

  13. 76 FR 5331 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of Antidumping Duty Administrative...) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from...

  14. 77 FR 4543 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of Antidumping Duty Administrative...) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from...

  15. 77 FR 50530 - Polyester Staple Fiber From China; Scheduling of an Expedited Five-Year Review Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1104 (Review)] Polyester Staple Fiber... Polyester Staple Fiber From China AGENCY: United States International Trade Commission. ACTION: Notice... CONTACT: Joanna Lo (202-205-1888), Office of Investigations, U.S. International Trade Commission, 500 E...

  16. Enhanced photocatalytic activity of Bi2WO6/TiO2 composite coated polyester fabric under visible light irradiation

    NASA Astrophysics Data System (ADS)

    Du, Zoufei; Cheng, Cheng; Tan, Lin; Lan, Jianwu; Jiang, Shouxiang; Zhao, Ludan; Guo, Ronghui

    2018-03-01

    In this study, a visible-light-driven photocatalyst Bi2WO6/TiO2 composite was reported using one-step hydrothermal method and then coated on the polyester fabric. The samples were systematically characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, UV-vis diffuse reflection spectroscopy and photoluminescence spectroscopy (PL). The photocatalytic activity of Bi2WO6/TiO2 coated polyester fabric was evaluated by degradation of Rhodamine B (RhB) and Methylene blue (MB) under visible light irradiation. The self-cleaning property of the fabrics was assessed through removing red wine stain. The results reveal that the Bi2WO6/TiO2 composites with irregular shape are coated on the polyester fabric successfully. The UV-vis absorption spectra show a broad absorption band in the visible region, which extends the scope of absorption spectrum and helps to improve the photocatalytic degradation efficiency. Photocatalytic activities of the Bi2WO6/TiO2 composite polyester fabric are associated with the content of TiO2. Bi2WO6/15%TiO2 coated polyester fabric exhibits the degradation efficiency for RhB and MB up to 98% and 95.1%, respectively, which is much higher than that of pure Bi2WO6 and TiO2 coated polyester fabric. Moreover, Bi2WO6/15%TiO2 coated polyester fabric shows good cycle stability toward continuous three cycles of photocatalytic experiment for dyes degradation. In addition, the Bi2WO6/TiO2 coated polyester fabric shows good self-cleaning property. This work could be extended to design of other composite photocatalyst coating on the fabric for enhancing activity by coupling suitable wide and narrow band-gap semiconductors.

  17. A study on the quality control of slow burning polyester

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Wang, Yinglei; Yan, Zhengfeng; Yu, Tao

    2018-04-01

    In this paper, the influence of the alcohol/acid mole ratio, reaction temperature, warm-up mode, end-capping, vacuity to the quality of slow burning polyester was studied. The hydroxyl value will increase when the alcohol/acid mole ratio increase, but the acid value and molecular weight will decrease. The molecular weight and molecular weight distribution of the polyester consistent with the designed one can be obtained by stepped heating up. Monobasic alcohol end-capping can be used to control the molecular weight effectively and reduce acid value. Stripping process narrow the molecular weight distribution and reduce the hydroxyl value. Decompression is in favor of the decrease of acid value and increase of the reaction speed to get qualified production.

  18. Thread angle dependency on flame spread shape over kenaf/polyester combined fabric

    NASA Astrophysics Data System (ADS)

    Azahari Razali, Mohd; Sapit, Azwan; Nizam Mohammed, Akmal; Nor Anuar Mohamad, Md; Nordin, Normayati; Sadikin, Azmahani; Faisal Hushim, Mohd; Jaat, Norrizam; Khalid, Amir

    2017-09-01

    Understanding flame spread behavior is crucial to Fire Safety Engineering. It is noted that the natural fiber exhibits different flame spread behavior than the one of the synthetic fiber. This different may influences the flame spread behavior over combined fabric. There is a research has been done to examined the flame spread behavior over kenaf/polyester fabric. It is seen that the flame spread shape is dependent on the thread angle dependency. However, the explanation of this phenomenon is not described in detail in that research. In this study, explanation about this phenomenon is given in detail. Results show that the flame spread shape is dependent on the position of synthetic thread. For thread angle, θ = 0°, the polyester thread is breaking when the flame approach to the thread and the kenaf thread tends to move to the breaking direction. This behavior produces flame to be ‘V’ shape. However, for thread angle, θ = 90°, the polyester thread melts while the kenaf thread decomposed and burned. At this angle, the distance between kenaf threads remains constant as flame approaches.

  19. Soil-release behaviour of polyester fabrics after chemical modification with polyethylene glycol

    NASA Astrophysics Data System (ADS)

    Miranda, T. M. R.; Santos, J.; Soares, G. M. B.

    2017-10-01

    The fibres cleanability depends, among other characteristics, on their hydrophilicity. Hydrophilic fibres are easy-wash materials but hydrophobic fibres are difficult to clean due to their higher water-repellent surfaces. This type of surfaces, like polyester (PET), produce an accumulation of electrostatic charges, which favors adsorption and retention of dirt. Thus, the polyester soil-release properties can be increased by finishing processes that improve fiber hydrophilicity. In present study, PET fabric modification was described by using poly(ethylene glycol) (PEG) and N,N´-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) chemically modified resin. Briefly, the modification process was carried out in two steps, one to hydrolyse the polyester and create hydroxyl and carboxylic acid groups on the surface and other to crosslink the PEG chains. The resulting materials were characterized by contact angle, DSC and FTIR-ATR methods. Additionally, the soil release behavior and the mechanical properties of modified PET were evaluated. For the best process conditions, the treated PET presented 0° contact angle, grade 5 stain release and acceptable mechanical performance.

  20. 75 FR 5763 - Notice of Correction to the First Administrative Review of Certain Polyester Staple Fiber From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China: Final... the People's Republic of China (``PRC''). See First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping Duty Administrative Review, 75...

  1. 75 FR 1336 - First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... System. Jianxin Fuda Chemical Fibre Factory. Comment 6: Correction of Name in Federal Register Notice... of Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping... duty order on certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC...

  2. 77 FR 39990 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... calls into question the reliability of this information. \\27\\ See Polyester Staple Fiber Final... Fiber From the People's Republic of China: Preliminary Results of the Antidumping Duty Administrative... duty order on certain polyester staple fiber from the People's Republic of China (``PRC'') for the...

  3. Synthesis of silver nanoparticles in melts of amphiphilic polyesters

    NASA Astrophysics Data System (ADS)

    Vasylyev, S.; Damm, C.; Segets, D.; Hanisch, M.; Taccardi, N.; Wasserscheid, P.; Peukert, W.

    2013-03-01

    The current work presents a one-step procedure for the synthesis of amphiphilic silver nanoparticles suitable for production of silver-filled polymeric materials. This solvent free synthesis via reduction of Tollens’ reagent as silver precursor in melts of amphiphilic polyesters consisting of hydrophilic poly(ethylene glycol) blocks and hydrophobic alkyl chains allows the production of silver nanoparticles without any by-product formation. This makes them especially interesting for the production of medical devices with antimicrobial properties. In this article the influences of the chain length of the hydrophobic block in the amphiphilic polyesters and the process temperature on the particle size distribution (PSD) and the stability of the particles against agglomeration are discussed. According to the results of spectroscopic and viscosimetric investigations the silver precursor is reduced to elemental silver nanoparticles by a single electron transfer process from the poly(ethylene glycol) chain to the silver ion.

  4. Polyester Wax: A New Embedding Medium for the Histopathologic Study of Human Temporal Bones

    PubMed Central

    Merchant, Saumil N.; Burgess, Barbara; O'Malley, Jennifer; Jones, Diane; Adams, Joe C.

    2007-01-01

    Background Celloidin and paraffin are the two common embedding mediums used for histopathologic study of the human temporal bone by light microscopy. Although celloidin embedding permits excellent morphologic assessment, celloidin is difficult to remove, and there are significant restrictions on success with immunostaining. Embedding in paraffin allows immunostaining to be performed, but preservation of cellular detail within the membranous labyrinth is relatively poor. Objectives/Hypothesis Polyester wax is an embedding medium that has a low melting point (37°C), is soluble in most organic solvents, is water tolerant, and sections easily. We hypothesized that embedding in polyester wax would permit good preservation of the morphology of the membranous labyrinth and, at the same time, allow the study of proteins by immunostaining. Methods Nine temporal bones from individuals aged 1 to 94 years removed 2 to 31 hours postmortem, from subjects who had no history of otologic disease, were used. The bones were fixed using 10% formalin, decal-cified using EDTA, embedded in polyester wax, and serially sectioned at a thickness of 8 to 12 μm on a rotary microtome. The block and knife were cooled with frozen CO2 (dry ice) held in a funnel above the block. Sections were placed on glass slides coated with a solution of 1% fish gelatin and 1% bovine albumin, followed by staining of selected sections with hematoxylin and eosin (H&E). Immunostaining was also performed on selected sections using antibodies to 200 kD neurofilament and Na-K-ATPase. Results Polyester wax–embedded sections demonstrated good preservation of cellular detail of the organ of Corti and other structures of the membranous labyrinth, as well as the surrounding otic capsule. The protocol described in this paper was reliable and consistently yielded sections of good quality. Immuno-staining was successful with both antibodies. Conclusion The use of polyester wax as an embedding medium for human temporal

  5. Microcellular processing of polylactide-hyperbranched polyester-nanoclay composites

    Treesearch

    Srikanth Pilla; Adam Kramschuster; Jungjoo Lee; Craig Clemons; Shaoqin Gong; Lih-Sheng Turng

    2010-01-01

    The effects of addition of hyperbranched polyesters (HBPs) and nanoclay on the material properties of both solid and microcellular polylactide (PLA) produced via a conventional and microcellular injection-molding process, respectively, were investigated. The effects of two different types of HBPs (i.e., Boltorn H2004® and Boltorn H20®) at the same...

  6. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, Toshifumi; Kukacka, Lawrence E.; Horn, William H.

    1985-01-01

    Quick setting polymer concrete compositions with excellent structural properties are disclosed; these polymer concrete compositions are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate, which may be wet, and with a source of bivalent metallic ions.

  7. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1981-11-04

    Quick setting polymer concrete compositions which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  8. 77 FR 54898 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Expedited...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... Fiber From the People's Republic of China: Final Results of Expedited Sunset Review of the Antidumping... (``sunset'') review of the antidumping duty order on certain polyester staple fiber from the People's... Department finds that revocation of the antidumping duty order on certain polyester staple fiber from the PRC...

  9. Physico-mechanical and wear properties of novel sustainable sour-weed fiber reinforced polyester composites

    NASA Astrophysics Data System (ADS)

    Patel, Vinay Kumar; Chauhan, Shivani; Katiyar, Jitendra Kumar

    2018-04-01

    In this study, a novel natural fiber i.e. Sour-weed botanically known as ‘Rumex acetosella’ has been first time introduced as natural reinforcements to polyester matrix. The natural fiber based polyester composites were fabricated by hand lay-up technique using different sizes and different weight percentages. In Sour-weed/Polyester composites, physical (density, water absorption and hardness), mechanical properties (tensile and impact properties) and wear properties (sand abrasion and sliding wear) were investigated for different sizes of sour weed of 0.6 mm, 5 mm, 10 mm, 15 mm and 20 mm at 3, 6 and 9 weight percent loading, respectively in polyester matrix. Furthermore, on average value of results, the multi-criteria optimization technique i.e. TOPSIS was employed to decide the ranking of the composites. From the optimized results, it was observed that Sour-weed composite reinforced with fiber’s size of 15 mm at 6 wt% loading demonstrated the best ranked composite exhibiting best overall properties as average tensile strength of 34.33 MPa, average impact strength of 10 Joule, average hardness of 12 Hv, average specific sand abrasion wear rate of 0.0607 mm3 N‑1m‑1, average specific sliding wear rate of 0.002 90 mm3 N‑1m‑1, average percentage of water absorption of 3.446% and average density of 1.013 among all fabricated composites.

  10. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1983-05-13

    Quick setting polymer concrete compositions are described which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  11. A novel polyester composite nanofiltration membrane formed by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC)

    NASA Astrophysics Data System (ADS)

    Cheng, Jun; Shi, Wenxin; Zhang, Lanhe; Zhang, Ruijun

    2017-09-01

    A novel polyester thin film composite nanofiltration (NF) membrane was prepared by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC) on polyethersulfone (PES) supporting membrane. The performance of the polyester composite NF membrane was optimized by regulating the preparation parameters, including reaction time, pH of the aqueous phase solution, pentaerythritol concentration and TMC concentration. A series of characterization, including permeation experiments, attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), atomic force microscopy (AFM), zeta potential analyzer and chlorine resistance experiments, were employed to study the properties of the optimized membrane. The results showed that the optimized polyester composite NF membrane exhibited very high rejection of Na2SO4 (98.1%), but the water flux is relatively low (6.1 L/m2 h, 0.5 MPa, 25 °C). The order of salt rejections is Na2SO4 > MgSO4 > MgCl2 > NaCl, which indicated the membrane was negatively charged, just consistent with the membrane zeta potential results. After treating by NaClO solutions with different concentrations (100 ppm, 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm) for 48 h, the results demonstrated that the polyester NF membrane had good chlorine resistance. Additionally, the polyester TFC NF membrane exhibits good long-term stability.

  12. Synthesis of lipase-catalysed silicone-polyesters and silicone-polyamides at elevated temperatures.

    PubMed

    Frampton, Mark B; Zelisko, Paul M

    2013-10-18

    More and more enzymes are being explored as alternatives to conventional catalysts in chemical reactions. To utilize these biocatalysts to their fullest, it is incumbent on researchers to gain a complete understanding of the reaction conditions that particular enzymes will tolerate. To this end siloxane-containing polyesters and polyamides have been produced via N435-mediated catalysis at temperatures well above the normal denaturation temperature for free CalB. Low molecular weight disiloxane-based acceptors release the enzyme from its acylated state with equal proficiency while longer chain siloxanes favours polyester synthesis. The thermal tolerance of the enzyme catalyst is increased using longer chain diesters and generally more hydrophobic substrates.

  13. Biological role of bacterial inclusion bodies: a model for amyloid aggregation.

    PubMed

    García-Fruitós, Elena; Sabate, Raimon; de Groot, Natalia S; Villaverde, Antonio; Ventura, Salvador

    2011-07-01

    Inclusion bodies are insoluble protein aggregates usually found in recombinant bacteria when they are forced to produce heterologous protein species. These particles are formed by polypeptides that cross-interact through sterospecific contacts and that are steadily deposited in either the cell's cytoplasm or the periplasm. An important fraction of eukaryotic proteins form inclusion bodies in bacteria, which has posed major problems in the development of the biotechnology industry. Over the last decade, the fine dissection of the quality control system in bacteria and the recognition of the amyloid-like architecture of inclusion bodies have provided dramatic insights on the dynamic biology of these aggregates. We discuss here the relevant aspects, in the interface between cell physiology and structural biology, which make inclusion bodies unique models for the study of protein aggregation, amyloid formation and prion biology in a physiologically relevant background. © 2011 The Authors Journal compilation © 2011 FEBS.

  14. Surface quality of unsaturated polyester resin processed via continuous multi-shot rotational molding

    NASA Astrophysics Data System (ADS)

    Ogila, K. O.; Yang, W.; Shao, M.; Tan, J.

    2017-05-01

    Unsaturated Polyester Resin is a versatile and cost efficient thermosetting plastic whose application in rotational molding is currently limited by its relatively high initial viscosity and heat of reaction. These material characteristics result in uneven material distribution, poor surface finish and imperfections in the moldings especially when large wall thicknesses are required. The current work attempts to remedy these shortcomings through the development of a continuous multi-shot system which adds predetermined loads of unsaturated polyester resin into a rotating mold at various intervals. As part of this system, a laboratory-scale uniaxial rotational molding machine was used to produce Unsaturated Polyester Resin moldings in single and double shots. Optimal processing conditions were determined through visual studies, three dimensional microscopic studies, thickness distribution analysis and Fourier Transform Infrared spectroscopy. Volume filling fractions of 0.049-0.065, second shot volumes of 0.5-0.75 from the first shot, rotational speeds of 15-20 rpm and temperatures of 30-50 °C resulted in moldings of suitable quality on both the inner and outer surfaces.

  15. A functionalizable polyester with free hydroxyl groups and tunable physiochemical and biological properties

    PubMed Central

    You, Zhengwei; Cao, Haiping; Gao, Jin; Shin, Paul H.; Day, Billy W.; Wang, Yadong

    2010-01-01

    Polyesters with free functional groups allow facile modifications with biomolecules, which can lead to versatile biomaterials that afford controlled interactions with cells and tissues. Efficient synthesis of functionalizable polyesters is still a challenge that greatly limits the availability and widespread applications of biofunctionalized synthetic polymers. Here we report a simple route to prepare a functionalizable polyester, poly(sebacoyl diglyceride) (PSeD) bearing free hydroxyl groups. The key synthetic step is an epoxide ring-opening polymerization, instead of the traditional polycondensation, that produces poly(glycerol sebacate) (PGS) [1]. PSeD has a more defined structure with mostly linear backbone, more free hydroxyl groups, higher molecular weight, and lower polydispersity than PGS. Crosslinking PSeD with sebacic acid yields a polymer five times tougher and more elastic than cured PGS. PSeD exhibits good cytocompatibility in vitro. Furthermore, functionalization by glycine proceeds with high efficiency. This versatile synthetic platform can offer a large family of biodegradable, functionalized polymers with tunable physiochemical and biological properties useful for a wide range of biomedical applications. PMID:20149441

  16. Impact behaviour of Napier/polyester composites under different energy levels

    NASA Astrophysics Data System (ADS)

    Fahmi, I.; Majid, M. S. Abdul; Afendi, M.; Haslan, M.; Helmi E., A.; M. Haameem J., A.

    2016-07-01

    The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.

  17. Development auxiliaries for dyeing polyester with disperse dyes at low temperatures

    NASA Astrophysics Data System (ADS)

    Carrion-Fite, F. J.; Radei, S.

    2017-10-01

    High-molecular weight organic compounds known as carriers are widely used to expedite polyester dyeing at atmospheric pressure at 100 °C. However, carriers are usually poorly biodegradable and can partially plasticize fibres. Also, dyeing at temperatures above 100 °C in the absence of a carrier entails using expensive equipment. In this work, we developed an alternative method for dyeing polyester at temperatures below 100 °C that reduces energy expenses, dispenses with the need to invest in new equipment and avoids the undesirable effects of non-biodegradable carriers. The method uses disperse dyes in a microemulsion containing a low proportion of a non-toxic organic solvent and either of two alternative development auxiliaries (coumarin and o-vanillin) that is prepared with the aid of ultrasound.

  18. Analytical approaches to identify potential migrants in polyester-polyurethane can coatings.

    PubMed

    Louise Bradley, Emma; Driffield, Malcolm; Guthrie, James; Harmer, Nick; Thomas Oldring, Peter Kenneth; Castle, Laurence

    2009-12-01

    The safety of a polyester-polyurethane can coating has been assessed using a suite of complementary analytical methods to identify and estimate the concentrations of potential chemical migrants. The polyester was based on phthalic acids and aliphatic diols. The polyisocyanate cross-linking agent was 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl cyclohexane homopolymer (IPDI) blocked with methylethylketone oxime (MEKO) to make a one-part formulation. The overall migrate, obtained using solvent extraction of cured films, comprised almost completely of 12 cyclic and one linear polyester oligomer up to molecular weight 800 and containing up to six monomer units. These 13 oligomers covered a total of 28 isomeric forms. Other minor components detected were plasticisers and surfactants as well as impurities present in the starting materials. There was no detectable residue of either the blocked isocyanate (<0.01 microg/dm(2)) used as the starting substance or the unblocked isocyanate (<0.02 microg/dm(2)). The level of extractable IPDI was used as an indicator of the completeness of cure in experimental coatings. These studies revealed that there was an influence of time, temperature and catalyst content. Polymerisation was also influenced by the additives used and by the ageing of the wet coating formulation over several months. These studies allow parameters to be specified to ensure that commercial production coatings receive a full cure giving low migration characteristics.

  19. Impact behaviour of Napier/polyester composites under different energy levels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fahmi, I., E-mail: fahmi-unimap@yahoo.com; Majid, M. S. Abdul, E-mail: shukry@unimap.edu.my; Afendi, M., E-mail: afendirojan@unimap.edu.my

    2016-07-19

    The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energymore » levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.« less

  20. 75 FR 33783 - Certain Polyester Staple Fiber from the Republic of Korea: Preliminary Results of the 2008 - 2009...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... Fiber from the Republic of Korea: Preliminary Results of the 2008 - 2009 Antidumping Duty Administrative... antidumping duty order on certain polyester staple fiber from the Republic of Korea. The period of review is May 1, 2008, through April 30, 2009. This review covers imports of certain polyester staple fiber from...

  1. Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

    NASA Astrophysics Data System (ADS)

    Nurazzi, N. Mohd; Khalina, A.; Sapuan, S. Mohd; Rahmah, M.

    2018-04-01

    This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

  2. The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

    PubMed

    Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

    2017-06-01

    Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

  3. The effect of woven and non-woven fiber structure on mechanical properties polyester composite reinforced kenaf

    NASA Astrophysics Data System (ADS)

    Ratim, S.; Bonnia, N. N.; Surip, S. N.

    2012-07-01

    The effects of woven and non-woven kenaf fiber on mechanical properties of polyester composites were studied at different types of perform structures. Composite polyester reinforced kenaf fiber has been prepared via hand lay-up process by varying fiber forms into plain weave, twill and mats structure. The reinforcing efficiency of different fiber structure was compared with control of unreinforced polyester sample. It was found that the strength and stiffness of the composites are largely affected by fiber structure. A maximum value for tensile strength of composite was obtained for twill weave pattern of fiber structure while no significant different for plain weave and mat structure. The elastic modulus of composite has shown some improvement on plain and twill weave pattern. Meanwhile, lower value of modulus elasticity achieved by mats structure composite as well as control sample. The modulus of rupture and impact resistance were also analyzed. The improvement of modulus of rupture value can be seen on plain and twill weave pattern. However impact resistance doesn't show significant improvement in all types of structure except for mat fiber. The mechanical properties of kenaf fiber reinforced polyester composite found to be increased with woven and non-woven fiber structures in composite.

  4. Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

    NASA Astrophysics Data System (ADS)

    Zohdy, Maged H.

    2005-06-01

    The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75 kGy followed by treatment with 15 ml l-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes.

  5. Green and selective polycondensation methods toward linear sorbitol-based polyesters: enzymatic versus organic and metal-based catalysis.

    PubMed

    Gustini, Liliana; Lavilla, Cristina; Janssen, William W T J; Martínez de Ilarduya, Antxon; Muñoz-Guerra, Sebastián; Koning, Cor E

    2016-08-23

    Renewable polyesters derived from a sugar alcohol (i.e., sorbitol) were synthesized by solvent-free polycondensation. The aim was to prepare linear polyesters with pendant hydroxyl groups along the polymer backbone. The performance of the sustainable biocatalyst SPRIN liposorb CALB [an immobilized form of Candida antarctica lipase B (CALB); SPRIN technologies] and the organo-base catalyst 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) were compared with two metal-based catalysts: dibutyl tin oxide (DBTO) and scandium trifluoromethanesulfonate [also known as scandium triflate, Sc(OTf)3 ]. For the four catalytic systems, the efficiency and selectivity for the incorporation of sorbitol were studied, mainly using (13) C and (31) P NMR spectroscopies, whereas side reactions, such as ether formation and dehydration of sorbitol, were evaluated using MALDI-TOF-MS. Especially the biocatalyst SPRIN liposorb CALB succeeded in incorporating sorbitol in a selective way without side reactions, leading to close-to-linear polyesters. By using a renewable hydroxyl-reactive curing agent based on l-lysine, transparent and glossy poly(ester urethane) networks were successfully synthesized offering a tangible example of bio-based coatings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Systematic computational and experimental investigation of lithium-ion transport mechanisms in polyester-based polymer electrolytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Webb, Michael A.; Jung, Yukyung; Pesko, Danielle M.

    Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds viamore » a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials.« less

  7. Systematic computational and experimental investigation of lithium-ion transport mechanisms in polyester-based polymer electrolytes

    DOE PAGES

    Webb, Michael A.; Jung, Yukyung; Pesko, Danielle M.; ...

    2015-07-10

    Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds viamore » a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials.« less

  8. Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

    PubMed Central

    2015-01-01

    Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds via a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials. PMID:27162971

  9. A kinetic study of hydrolysis of polyester elastomer in magnetic tape

    NASA Technical Reports Server (NTRS)

    Yamamoto, K.; Watanabe, H.

    1994-01-01

    A useful method for kinetic study of the hydrolysis of polyester elastomer is established which uses the number-average molecular weight. The reasonableness of this method is confirmed and the effect of magnetic particles on hydrolysis is considered.

  10. Fungi are the predominant micro-organisms responsible for degradation of soil-buried polyester polyurethane over a range of soil water holding capacities.

    PubMed

    Barratt, S R; Ennos, A R; Greenhalgh, M; Robson, G D; Handley, P S

    2003-01-01

    To investigate the relationship between soil water holding capacity (WHC) and biodegradation of polyester polyurethane (PU) and to quantify and identify the predominant degrading micro-organisms in the biofilms on plastic buried in soil. High numbers of both fungi and bacteria were recovered from biofilms on soil-buried dumb-bell-shaped pieces of polyester PU after 44 days at 15-100% WHC. The tensile strength of the polyester PU was reduced by up to 60% over 20-80% soil WHC, but no reduction occurred at 15, 90 or 100% soil WHC. A PU agar clearance assay indicated that fungi, but not bacteria were, the major degrading organisms in the biofilms on polyester PU and 10-30% of all the isolated fungi were able to degrade polyester PU in this assay. A 5.8S rDNA sequencing identified 13 strains of fungi representing the three major colony morphology types responsible for PU degradation. Sequence homology matches identified these strains as Nectria gliocladioides (five strains), Penicillium ochrochloron (one strain) and Geomyces pannorum (seven strains). Geomyces pannorum was the predominant organism in the biofilms comprising 22-100% of the viable polyester PU degrading fungi. Polyester PU degradation was optimum under a wide range of soil WHC and the predominant degrading organisms were fungi. By identifying the predominant degrading fungi in soil and studying the optimum WHC conditions for degradation of PU it allows us to better understand how plastics are broken down in the environment such as in landfill sites.

  11. PHACOS, a functionalized bacterial polyester with bactericidal activity against methicillin-resistant Staphylococcus aureus

    PubMed Central

    Dinjaski, Nina; Fernández-Gutiérrez, Mar; Selvam, Shivaram; Parra-Ruiz, Francisco J.; Lehman, Susan M.; Román, Julio San; García, Ernesto; García, José L.; García, Andrés J.; Prieto, María Auxiliadora

    2013-01-01

    Biomaterial-associated infections represent a significant clinical problem, and treatment of these microbial infections is becoming troublesome due to the increasing number of antibiotic-resistant strains. Here, we report a naturally functionalized bacterial polyhydroxyalkanoate (PHACOS) with antibacterial properties. We demonstrate that PHACOS selectively and efficiently inhibits the growth of methicillin-resistant Staphylococcus aureus (MRSA) both in vitro and in vivo. This ability has been ascribed to the functionalized side chains containing thioester groups. Significantly less (3.2-fold) biofilm formation of S. aureus was detected on PHACOS compared to biofilms formed on control poly(3-hydroxyoctanoate-co-hydroxyhexanoate) and poly(ethylene terephthalate), but no differences were observed in bacterial adhesion among these polymers. PHACOS elicited minimal cytotoxic and inflammatory effects on murine macrophages and supported normal fibroblast adhesion. In vivo fluorescence imaging demonstrated minimal inflammation and excellent antibacterial activity for PHACOS compared to controls in an in vivo model of implant-associated infection. Additionally, reductions in neutrophils and macrophages in the vicinity of sterile PHACOS compared to sterile PHO implant were observed by immunohistochemistry. Moreover, a similar percentage of inflammatory cells was found in the tissue surrounding sterile PHACOS and S. aureus pre-colonized PHACOS implants, and these levels were significantly lower than S. aureus pre-colonized control polymers. These findings support a contact active surface mode of antibacterial action for PHACOS and establish this functionalized polyhydroxyalkanoate as an infection-resistant biomaterial. PMID:24094939

  12. Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

    NASA Astrophysics Data System (ADS)

    Poillucci, Richard

    Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an

  13. Tandem mass spectrometry characteristics of polyester anions and cations formed by electrospray ionization.

    PubMed

    Arnould, Mark A; Buehner, Rita W; Wesdemiotis, Chrys; Vargas, Rafael

    2005-01-01

    Electrospray ionization of polyesters composed of isophthalic acid and neopentyl glycol produces carboxylate anions in negative mode and mainly sodium ion adducts in positive mode. A tandem mass spectrometry (MS/MS) study of these ions in a quadrupole ion trap shows that the collisionally activated dissociation pathways of the anions are simpler than those of the corresponding cations. Charge-remote fragmentations predominate in both cases, but the spectra obtained in negative mode are devoid of the complicating cation exchange observed in positive mode. MS/MS of the Na(+) adducts gives rise to a greater number of fragments but not necessarily more structural information. In either positive or negative mode, polyester oligomers with different end groups fragment by similar mechanisms. The observed fragments are consistent with rearrangements initiated by the end groups. Single-stage ESI mass spectra also are more complex in positive mode because of extensive H/Na substitutions; this is also true for matrix-assisted laser desorption ionization (MALDI) mass spectra. Hence, formation and analysis of anions might be the method of choice for determining block length, end group structure and copolymer sequence, provided the polyester contains at least one carboxylic acid end group that is ionizable to anions.

  14. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    NASA Astrophysics Data System (ADS)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  15. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    NASA Astrophysics Data System (ADS)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

    2014-10-01

    Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  16. Comparison of polyester, film-yarn composite, balloon materials subjected to shear and biaxial loading

    NASA Technical Reports Server (NTRS)

    Niccum, R. J.

    1972-01-01

    A series of candidate materials for use in large balloons was tested and their tensile and shear strength capabilities were compared. The tests were done in a cold box at -68 C (-90 F). Some of these materials were fabricated on a special machine called the flying thread loom. This machine laminates various patterns of polyester yarn to a thin polyester film. The results show that the shear strength of materials changes with the angle selected for the transverse yarns, and substantial increases in biaxial load carrying capabilities, compared to materials formerly used, are possible. The loom capabilities and the test methods are discussed.

  17. The late endocytic Rab39a GTPase regulates the interaction between multivesicular bodies and chlamydial inclusions.

    PubMed

    Gambarte Tudela, Julian; Capmany, Anahi; Romao, Maryse; Quintero, Cristian; Miserey-Lenkei, Stephanie; Raposo, Graca; Goud, Bruno; Damiani, Maria Teresa

    2015-08-15

    Given their obligate intracellular lifestyle, Chlamydia trachomatis ensure that they have access to multiple host sources of essential lipids by interfering with vesicular transport. These bacteria hijack Rab6-, Rab11- and Rab14-controlled trafficking pathways to acquire sphingomyelin from the Golgi complex. Another important source of sphingolipids, phospholipids and cholesterol are multivesicular bodies (MVBs). Despite their participation in chlamydial inclusion development and bacterial replication, the molecular mechanisms mediating the interaction between MVBs and chlamydial inclusions remain unknown. In the present study, we demonstrate that Rab39a labels a subset of late endocytic vesicles - mainly MVBs - that move along microtubules. Moreover, Rab39a is actively recruited to chlamydial inclusions throughout the pathogen life cycle by a bacterial-driven process that depends on the Rab39a GTP- or GDP-binding state. Interestingly, Rab39a participates in the delivery of MVBs and host sphingolipids to maturing chlamydial inclusions, thereby promoting inclusion growth and bacterial development. Taken together, our findings indicate that Rab39a favours chlamydial replication and infectivity. This is the first report showing that a late endocytic Rab GTPase is involved in chlamydial infection development. © 2015. Published by The Company of Biologists Ltd.

  18. Langmuir-Blodgett Films of Supported Polyester Dendrimers

    PubMed Central

    Redón, Rocío; Carreón-Castro, M. Pilar; Mendoza-Martínez, F. J.

    2012-01-01

    Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area (π/A) and Brewster angle microscopy (BAM) observations. PMID:24052855

  19. A solvent induced crystallisation method to imbue bioactive ingredients of neem oil into the compact structure of poly (ethylene terephthalate) polyester.

    PubMed

    Ali, Wazed; Sultana, Parveen; Joshi, Mangala; Rajendran, Subbiyan

    2016-07-01

    Neem oil, a natural antibacterial agent from neem tree (Azadarichtaindica) has been used to impart antibacterial activity to polyester fabrics. Solvent induced polymer modification method was used and that facilitated the easy entry of neem molecules into the compact structure of polyethylene terephthalate (PET) polyester. The polyester fabric was treated with trichloroacetic acid-methylene chloride (TCAMC) solvent system at room temperature prior to treatment with neem oil. The concentration of TCAMC and the treatment time were optimised. XRD and SEM results showed that the TCAMC treatment causes polymer modification and morphological changes in the PET polyester. Antibacterial activity of TCAMC pre-treated and neem-oil-treated polyester fabric was tested using AATCC qualitative and quantitative methods. Both Gram-positive and Gram-negative organisms were used to determine the antimicrobial activity. It was observed that the treated fabric registers substantial antimicrobial activity against both the Staphylococcus aureus (Gram-positive) and the Escherichia coli (Gram-negative) and the effect increases with the increase in concentration of TCAMC treatment. The antibacterial effect remains substantial even after 25 launderings. A kinetic growth study involving the effect of antibacterial activity at various incubation times was carried out. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Chemical and enzymatic catalytic routes to polyesters and oligopeptides biobased materials

    NASA Astrophysics Data System (ADS)

    Zhu, Jianhui

    My Ph.D research focuses on the synthesis and property studies of different biobased materials, including polyesters, polyurethanes and oligopeptides. The first study describes the synthesis, crystal structure and physico-mechanical properties of a bio-based polyester prepared from 2,5-furandicarboxylic acid (FDCA) and 1,4-butanediol. Melt-polycondensation experiments were conducted by a two-stage polymerization using titanium tetraisopropoxide (Ti[OiPr] 4) as catalyst. Polymerization conditions (catalyst concentration, reaction time and 2nd stage reaction temperature) were varied to optimize poly(butylene furan dicarboxylate), PBF, molecular weight. A series of PBFs with different Mw were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Dynamic Mechanical Thermal Analysis (DMTA), X-Ray diffraction and tensile testing. Influence of molecular weight and melting/crystallization enthalpy on PBF material tensile properties was explored. Cold-drawing tensile tests at room temperature for PBF with Mw 16K to 27K showed a brittle-to-ductile transition. When Mw reaches 38K, the Young's Modulus of PBF remains above 900 MPa, and the elongation at break increases to above 1000%. The mechanical properties, thermal properties and crystal structures of PBF were similar to petroleum derived poly(butylenes terephthalate), PBT. Fiber diagrams of uniaxially stretched PBF films were collected, indexed, and the unit cell was determined as triclinic (a=4.78(3) A, b=6.03(5) A, c=12.3(1) A, alpha=110.1(2)°, beta=121.1(3)°, gamma=100.6(2)°). A crystal structure was derived from this data and final atomic coordinates are reported. We concluded that there is a close similarity of the PBF structure to PBT alpha- and beta-forms. In the second study, a biobased long chain polyester polyol (PC14-OH) was synthesized from o-hydroxytetradecanoic acid (o-HOC14) and 1,4-butanediol. The first section about polyester polyurethanes describes the synthesis

  1. Elucidation of non-intentionally added substances migrating from polyester-polyurethane lacquers using automated LC-HRMS data processing.

    PubMed

    Omer, Elsa; Cariou, Ronan; Remaud, Gérald; Guitton, Yann; Germon, Hélène; Hill, Paul; Dervilly-Pinel, Gaud; Le Bizec, Bruno

    2018-03-08

    An untargeted strategy aiming at identifying non-intentionally added substances (NIAS) migrating from coatings was developed. This innovative approach was applied to two polyester-polyurethane lacquers, for which suppliers previously provided the identity of the monomers involved. Lacquers were extracted with acetonitrile and analyzed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Data, acquired in the full scan mode, were processed using an open-source R-environment (xcms and CAMERA packages) to list the detected features and deconvolute them in groups related to individual compounds. The most intense groups, accounting for more than 85% of cumulated feature intensities, were then investigated. A homemade database, populated with predicted polyester oligomer combinations from a relevant selection of diols and diacids, enabled highlighting the presence of 14 and 17 cyclic predicted polyester oligomers in the two lacquers, including three mutual combinations explained by common known monomers. Combination hypotheses were strengthened by chromatographic considerations and by the investigation of fragmentation patterns. Regarding unpredicted migrating substances, four monomers were hypothesised to explain several polyester or caprolactam oligomer series. Finally, considering both predicted and tentatively elucidated unpredicted oligomers, it was possible to assign hypotheses to features representing up to 82% and 90% of the cumulated intensities in the two lacquers, plus 9% and 3% (respectively) originating from the procedural blank. Graphical abstract Elucidation of non-intentionally added substances.

  2. New evidence for Cu-decorated binary-oxides mediating bacterial inactivation/mineralization in aerobic media.

    PubMed

    Rtimi, S; Pulgarin, C; Bensimon, M; Kiwi, J

    2016-08-01

    Binary oxide semiconductors TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 (TiO2-ZrO2-Cu) uniform films were sputtered on polyester (PES). These films were irradiated under low intensity solar simulated light and led to bacterial inactivation in aerobic and anaerobic media as evaluated by CFU-plate counting. But bacterial mineralization was only induced by TiO2-ZrO2-Cu in aerobic media. The highly oxidative radicals generated on the films surface under light were identified by the use of appropriate scavengers. The hole generated on the TiO2-ZrO2 films is shown to be the main specie leading to bacterial inactivation. TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 films release Zr and Ti <1ppb and Cu 4.6ppb/cm(2) as determined by inductively coupled plasma mass spectrometry (ICP-MS) This level is far below the citotoxicity permitted level allowed for mammalian cells suggesting that bacterial disinfection proceeds through an oligodynamic effect. By Fourier transform attenuated infrared spectroscopy (ATR-FTIR) the systematic shift of the predominating νs(CH2) vibrational-rotational peak making up most of the bacterial cell-wall content in C was monitored. Based on this evidence a mechanism suggested leading to CH bond stretching followed by cell lysis and cell death. Bacterial inactivation cycling was observed on TiO2-ZrO2-Cu showing the stability of these films leading to bacterial inactivation. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Renewable unsaturated polyesters from muconic acid

    DOE PAGES

    Rorrer, Nicholas A.; Dorgan, John R.; Vardon, Derek R.; ...

    2016-09-27

    cis,cis-Muconic acid is an unsaturated dicarboxylic acid that can be produced in high yields via biological conversion of sugars and lignin-derived aromatic compounds. Muconic acid is often targeted as an intermediate to direct replacement monomers such as adipic or terephthalic acid. However, the alkene groups in muconic acid provide incentive for its direct use in polymers, for example, in the synthesis of unsaturated polyester resins. Here, biologically derived muconic acid is incorporated into polyesters via condensation polymerization using the homologous series of poly(ethylene succinate), poly(propylene succinate), poly(butylene succinate), and poly(hexylene succinate). Additionally, dimethyl cis,cis-muconate is synthesized and subsequently incorporated intomore » poly(butylene succinate). NMR measurements demonstrate that alkene bonds are present in the polymer backbones. In all cases, the glass transition temperatures are increased whereas the melting and degradation temperatures are decreased. In the case of poly(butylene succinate), utilization of neat muconic acid yields substoichiometric incorporation consistent with a tapered copolymer structure, whereas the muconate diester exhibits stoichiometric incorporation and a random copolymer structure based on thermal and mechanical properties. Prototypical fiberglass panels were produced by infusing a mixture of low molecular weight poly(butylene succinate-co-muconate) and styrene into a woven glass mat and thermally initiating polymerization resulting in thermoset composites with shear moduli in excess of 30 GPa, a value typical of commercial composites. The increased glass transition temperatures with increasing mucconic incorporation leads to improved composites properties. We find that the molecular tunability of poly(butylene succinate-co-muconate) as a tapered or random copolymer enables the tunability of composite properties. Altogether, this study demonstrates the utility of muconic acid as a

  4. Renewable unsaturated polyesters from muconic acid

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rorrer, Nicholas A.; Dorgan, John R.; Vardon, Derek R.

    cis,cis-Muconic acid is an unsaturated dicarboxylic acid that can be produced in high yields via biological conversion of sugars and lignin-derived aromatic compounds. Muconic acid is often targeted as an intermediate to direct replacement monomers such as adipic or terephthalic acid. However, the alkene groups in muconic acid provide incentive for its direct use in polymers, for example, in the synthesis of unsaturated polyester resins. Here, biologically derived muconic acid is incorporated into polyesters via condensation polymerization using the homologous series of poly(ethylene succinate), poly(propylene succinate), poly(butylene succinate), and poly(hexylene succinate). Additionally, dimethyl cis,cis-muconate is synthesized and subsequently incorporated intomore » poly(butylene succinate). NMR measurements demonstrate that alkene bonds are present in the polymer backbones. In all cases, the glass transition temperatures are increased whereas the melting and degradation temperatures are decreased. In the case of poly(butylene succinate), utilization of neat muconic acid yields substoichiometric incorporation consistent with a tapered copolymer structure, whereas the muconate diester exhibits stoichiometric incorporation and a random copolymer structure based on thermal and mechanical properties. Prototypical fiberglass panels were produced by infusing a mixture of low molecular weight poly(butylene succinate-co-muconate) and styrene into a woven glass mat and thermally initiating polymerization resulting in thermoset composites with shear moduli in excess of 30 GPa, a value typical of commercial composites. The increased glass transition temperatures with increasing mucconic incorporation leads to improved composites properties. We find that the molecular tunability of poly(butylene succinate-co-muconate) as a tapered or random copolymer enables the tunability of composite properties. Altogether, this study demonstrates the utility of muconic acid as a

  5. Effect of a depilatory agent on cotton, polyester, and rayon versus human hair in a laboratory setting.

    PubMed

    Plesa, Jocelyn A; Shoup, Kelly; Manole, Mioara D; Hickey, Robert W

    2015-03-01

    We examine the ability of a depilatory agent, Nair, to dissolve strands of hair, cotton, polyester, and rayon. We conducted a bench laboratory study in which we tested single strands of hair and natural and synthetic fibers under static tension with a 10.8-g weight and application of Nair. The dependent variable, time until breakage, was recorded. If the strand did not break within 8 hours, the experiment was discontinued. Three types of hair were tested (thin, medium, and thick, as recorded per diameter). Three types of natural and synthetic fibers were tested (cotton, polyester, and rayon). All types of hair had breakage within 10 minutes of the Nair application. Synthetic materials had no breakage after 8 hours with application of Nair. Depilatory agents dissolve hair under tension within minutes. However, they do not dissolve cotton, polyester, and rayon even after many hours of application. Copyright © 2014 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  6. Mechanical properties of three layer glass fibre reinforced unsaturated polyester filled with P84 Polyimide

    NASA Astrophysics Data System (ADS)

    Ibrahim, Nik Noor Idayu Nik; Mamauod, Siti Nur Liyana; Romli, Ahmad Zafir

    2017-12-01

    The glass fibre reinforced orthophthalic unsaturated polyester composite was widely used in the pipeline industry as a replacement to the corroded steel pipes. A filler which possesses high mechanical performance at high temperature; P84 Polyimide used as the particulate reinforcement in the unsaturated polyester matrix system to increase the mechanical performance of the glass fibre reinforced unsaturated polyester. The glass fibre composite laminates were prepared through a hand lay-up technique and fabricated into three layer laminate. Prior to be used as the matrix system in the lamination process, the unsaturated polyester resin was mixed with masterbatch P84 Polyimide at three loadings amount of 1, 3, and 5 wt%. The addition of P84 Polyimide at 1, 3, and 5 wt% increased the tensile properties and flexural properties especially at 1 wt% filler loading. As the filler loading increased, the tensile properties and flexural properties showed decreasing pattern. In the dynamic mechanical analysis, the values of storage modulus were taken at two points; 50 °C and 150 °C which were the storage modulus before and after the glass transition temperature. All storage modulus showed fluctuation trend for both before and after Tg. However, the storage modulus of the filled composite laminates after Tg showed higher values than unfilled composite laminates at all filler loading. Since the P84 Polyimide possesses high thermal stability, the presence of P84 Polyimide inside the composite system had assisted in delaying the Tg. In terms of the filler dispersion, the Cole-Cole plot showed an imperfect semi-circular shape which indicated good filler dispersion.

  7. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... section, partial phosphoric acid esters of polyester resins are prepared by the reaction of trimellitic anhydride with 2,2-dimethyl-1,3-propanediol followed by reaction of the resin thus produced with phosphoric... characterizing the type of food and under the conditions of time and temperature characterizing the conditions of...

  8. Initial studies of a flexural member composed of glass-fiber reinforced polyester resin.

    DOT National Transportation Integrated Search

    1973-01-01

    An investigation was conducted of the structural behavior of a flexural member composed entirely of glass-fiber reinforced polyester resin. Three experimental girders were fabricated and load-tested in the laboratory. The physical characteristics of ...

  9. A novel biological recovery approach for PHA employing selective digestion of bacterial biomass in animals.

    PubMed

    Ong, Su Yean; Zainab-L, Idris; Pyary, Somarajan; Sudesh, Kumar

    2018-03-01

    Polyhydroxyalkanoate (PHA) is a family of microbial polyesters that is completely biodegradable and possesses the mechanical and thermal properties of some commonly used petrochemical-based plastics. Therefore, PHA is attractive as a biodegradable thermoplastic. It has always been a challenge to commercialize PHA due to the high cost involved in the biosynthesis of PHA via bacterial fermentation and the subsequent purification of the synthesized PHA from bacterial cells. Innovative enterprise by researchers from various disciplines over several decades successfully reduced the cost of PHA production through the efficient use of cheap and renewable feedstock, precisely controlled fermentation process, and customized bacterial strains. Despite the fact that PHA yields have been improved tremendously, the recovery and purification processes of PHA from bacterial cells remain exhaustive and require large amounts of water and high energy input besides some chemicals. In addition, the residual cell biomass ends up as waste that needs to be treated. We have found that some animals can readily feed on the dried bacterial cells that contain PHA granules. The digestive system of the animals is able to assimilate the bacterial cells but not the PHA granules which are excreted in the form of fecal pellets, thus resulting in partial recovery and purification of PHA. In this mini-review, we will discuss this new concept of biological recovery, the selection of the animal model for biological recovery, and the properties and possible applications of the biologically recovered PHA.

  10. Thermal Cyclic Resistance Polyester Resin Composites Reinforce Fiber Nut Shell

    NASA Astrophysics Data System (ADS)

    Fahmi, Hendriwan

    2017-12-01

    The purpose of study is to determine the effect of fiber length and thermal cyclic of the bending strength of polyester resin composite reinforced by fibers nut shell. The materials used in this study is a nut shell fibers with fiber length of 1 cm, 2 cm and 3 cm and polyester resin with composition 70-30%wt. Fiber nut shell treated soaking in NaOH 30% for 30 minutes, then rinse with clean water so that the fiber free of alkali and then dried. Furthermore, the composite is heated in an oven to a temperature of 100°C for 1 hour and then cooled in the open with a variety of thermal cyclic 30, 40, and 50 times. Bending properties of composites known through the testing process using a three-point bending test equipment universal testing machine. The test results show that the bending strength bending highest in fiber length of 3 cm with 30 treatment cycles of thermal to the value of 53.325 MPa, while the lowest occurred in bending strength fiber length of 1 cm with no cycles of thermal treatment to the value of 30.675 MPa.

  11. Radiation-induced changes affecting polyester based polyurethane binder

    NASA Astrophysics Data System (ADS)

    Pierpoint, Sujita Basi

    The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of radiation on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the radiation-induced changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion

  12. Transparent Composites Made from Tunicate Cellulose Membranes and Environmentally Friendly Polyester.

    PubMed

    Zhao, Yadong; Moser, Carl; Henriksson, Gunnar

    2018-05-25

    A series of optically transparent composites were made by using tunicate cellulose membranes, in which the naturally organized cellulose microfibrillar network structure of tunicate tunics was preserved and used as the template and a solution of glycerol and citric acid at different molar ratios was used as the matrix. Polymerization through ester bond formation occurred at elevated temperatures without any catalyst, and water was released as the only byproduct. The obtained composites had a uniform and dense structure. Thus, the produced glycerol citrate polyester improved the transparency of the tunicate cellulose membrane while the cellulose membrane provided rigidity and strength to the prepared composite. The interaction between cellulose and polyester afforded the composites high thermal stability. Additionally, the composites were optically transparent and their shape, strength, and flexibility were adjustable by varying the formulation and reaction conditions. These composites of cellulose, glycerol, and citric acid are renewable and biocompatible and have many potential applications as structural materials in packaging, flexible displays, and solar cells. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Surface modification of metallic cardiovascular stents by strongly adhering aliphatic polyester coatings.

    PubMed

    Jérôme, Christine; Aqil, Abdelhafid; Voccia, Samuël; Labaye, David-Emmanuel; Maquet, Véronique; Gautier, Sandrine; Bertrand, Olivier F; Jérôme, Robert

    2006-03-01

    This article reports on a novel two-step strategy for the coating of cardiovascular stents by strongly adhering biocompatible and biodegradable aliphatic polyesters. First, a precoating of poly(ethylacrylate) (PEA) was electrografted onto the metallic substrate by cathodic reduction of the parent monomer in dimethylformamide (DMF). The electrodeposition of PEA, in a good solvent of it, was confirmed by both Infra-red and Raman spectroscopies. The pendant ester groups of PEA were then chemically reduced into aluminum alkoxides, able to initiate the ring-opening polymerization (ROP) of either D,L-lactide (LA) or epsilon-caprolactone (CL). Growth of biodegradable PLA or PCL coatings from the adhering precoating was confirmed by both Infra-red and Raman spectroscopies, and directly observed by scanning electron microscopy (SEM). This type of coating can act as an anchoring layer for the subsequent casting of drug-loaded polyester films allowing the controlled release of antiproliferative agents for the treatment of in-stent restenosis. (c) 2005 Wiley Periodicals, Inc.

  14. Biochemical and Structural Insights into Enzymatic Depolymerization of Polylactic Acid and Other Polyesters by Microbial Carboxylesterases.

    PubMed

    Hajighasemi, Mahbod; Nocek, Boguslaw P; Tchigvintsev, Anatoli; Brown, Greg; Flick, Robert; Xu, Xiaohui; Cui, Hong; Hai, Tran; Joachimiak, Andrzej; Golyshin, Peter N; Savchenko, Alexei; Edwards, Elizabeth A; Yakunin, Alexander F

    2016-06-13

    Polylactic acid (PLA) is a biodegradable polyester derived from renewable resources, which is a leading candidate for the replacement of traditional petroleum-based polymers. Since the global production of PLA is quickly growing, there is an urgent need for the development of efficient recycling technologies, which will produce lactic acid instead of CO2 as the final product. After screening 90 purified microbial α/β-hydrolases, we identified hydrolytic activity against emulsified PLA in two uncharacterized proteins, ABO2449 from Alcanivorax borkumensis and RPA1511 from Rhodopseudomonas palustris. Both enzymes were also active against emulsified polycaprolactone and other polyesters as well as against soluble α-naphthyl and p-nitrophenyl monoesters. In addition, both ABO2449 and RPA1511 catalyzed complete or extensive hydrolysis of solid PLA with the production of lactic acid monomers, dimers, and larger oligomers as products. The crystal structure of RPA1511 was determined at 2.2 Å resolution and revealed a classical α/β-hydrolase fold with a wide-open active site containing a molecule of polyethylene glycol bound near the catalytic triad Ser114-His270-Asp242. Site-directed mutagenesis of both proteins demonstrated that the catalytic triad residues are important for the hydrolysis of both monoester and polyester substrates. We also identified several residues in RPA1511 (Gln172, Leu212, Met215, Trp218, and Leu220) and ABO2449 (Phe38 and Leu152), which were not essential for activity against soluble monoesters but were found to be critical for the hydrolysis of PLA. Our results indicate that microbial carboxyl esterases can efficiently hydrolyze various polyesters making them attractive biocatalysts for plastics depolymerization and recycling.

  15. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    NASA Astrophysics Data System (ADS)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-04-01

    Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(Cdbnd O, Csbnd OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  16. Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

    PubMed

    Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

    2014-09-01

    Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Polyester composites reinforced with corona-treated fibers from pine, eucalyptus and sugarcane bagasse

    USDA-ARS?s Scientific Manuscript database

    This study aims to evaluate plant fibers that were surface activated with NaOH and corona discharge before incorporating in ortho unsaturated polyester-based fiber composites. It demonstrates the potential use of lignocellulosic particles, especially eucalyptus that presented the higher values for a...

  18. Bacterial inclusion bodies as potential synthetic devices for pathogen recognition and a therapeutic substance release.

    PubMed

    Talafová, Klaudia; Hrabárová, Eva; Chorvát, Dušan; Nahálka, Jozef

    2013-02-07

    Adhesins of pathogens recognise the glycans on the host cell and mediate adherence. They are also crucial for determining the tissue preferences of pathogens. Currently, glyco-nanomaterials provide potential tool for antimicrobial therapy. We demonstrate that properly glyco-tailored inclusion bodies can specifically bind pathogen adhesins and release therapeutic substances. In this paper, we describe the preparation of tailored inclusion bodies via the conjugation of indicator protein aggregated to form inclusion bodies with soluble proteins. Whereas the indicator protein represents a remedy, the soluble proteins play a role in pathogen recognition. For conjugation, glutaraldehyde was used as linker. The treatment of conjugates with polar lysine, which was used to inactivate the residual glutaraldehyde, inhibited unwanted hydrophobic interactions between inclusion bodies. The tailored inclusion bodies specifically interacted with the SabA adhesin from Helicobacter pylori aggregated to form inclusion bodies that were bound to the sialic acids decorating the surface of human erythrocytes. We also tested the release of indicator proteins from the inclusion bodies using sortase A and Ssp DNAB intein self-cleaving modules, respectively. Sortase A released proteins in a relatively short period of time, whereas the intein cleavage took several weeks. The tailored inclusion bodies are promising "nanopills" for biomedical applications. They are able to specifically target the pathogen, while a self-cleaving module releases a soluble remedy. Various self-cleaving modules can be enabled to achieve the diverse pace of remedy release.

  19. Bacterial inclusion bodies as potential synthetic devices for pathogen recognition and a therapeutic substance release

    PubMed Central

    2013-01-01

    Background Adhesins of pathogens recognise the glycans on the host cell and mediate adherence. They are also crucial for determining the tissue preferences of pathogens. Currently, glyco-nanomaterials provide potential tool for antimicrobial therapy. We demonstrate that properly glyco-tailored inclusion bodies can specifically bind pathogen adhesins and release therapeutic substances. Results In this paper, we describe the preparation of tailored inclusion bodies via the conjugation of indicator protein aggregated to form inclusion bodies with soluble proteins. Whereas the indicator protein represents a remedy, the soluble proteins play a role in pathogen recognition. For conjugation, glutaraldehyde was used as linker. The treatment of conjugates with polar lysine, which was used to inactivate the residual glutaraldehyde, inhibited unwanted hydrophobic interactions between inclusion bodies. The tailored inclusion bodies specifically interacted with the SabA adhesin from Helicobacter pylori aggregated to form inclusion bodies that were bound to the sialic acids decorating the surface of human erythrocytes. We also tested the release of indicator proteins from the inclusion bodies using sortase A and Ssp DNAB intein self-cleaving modules, respectively. Sortase A released proteins in a relatively short period of time, whereas the intein cleavage took several weeks. Conclusions The tailored inclusion bodies are promising “nanopills” for biomedical applications. They are able to specifically target the pathogen, while a self-cleaving module releases a soluble remedy. Various self-cleaving modules can be enabled to achieve the diverse pace of remedy release. PMID:23391325

  20. Biomimetic polyesters and their role in ion transport across cell membranes.

    PubMed

    Jedliński, Z; Kurcok, P; Adamus, G; Juzwa, M

    2000-01-01

    Syntheses of biomimetic low-molecular weight poly-(R)-3-hydroxybutanoate mediated by three types of supramolecular catalysts are presented. The utility of these synthetic polyesters for preparation of artificial channels in phospholipid bilayers capable of sodium and calcium ion transport across cell membranes, is discussed. Further studies on possible applications of these bio-polymers for manufacturing drugs of prolonged activity are under way.

  1. Crossing the border - Solute entry into the chlamydial inclusion.

    PubMed

    Haferkamp, Ilka

    2017-08-26

    Chlamydiales comprise important human and animal pathogens as well as endosymbionts of amoebae. Generally, these obligate intracellular living bacteria are characterized by a biphasic developmental cycle, a reduced genome and a restricted metabolic capacity. Because of their metabolic impairment, Chlamydiales essentially rely on the uptake of diverse metabolites from their hosts. Chlamydiales thrive in a special compartment, the inclusion, and hence are surrounded by an additional membrane. Solutes might enter the inclusion through pores and open channels or by redirection of host vesicles, which fuse with the inclusion membrane and release their internal cargo. Recent investigations shed new light on the chlamydia-host interaction and identified an additional way for nutrient uptake into the inclusion. Proteome studies and targeting analyses identified chlamydial and host solute carriers in inclusions of Chlamydia trachomatis infected cells. These transporters are involved in the provision of UDP-glucose and biotin, and probably deliver further metabolites to the inclusion. By the controlled recruitment of specific solute carriers to the inclusion, the chlamydial resident thus can actively manipulate the metabolite availability and composition in the inclusion. This review summarizes recent findings and new ideas on carrier mediated solute uptake into the chlamydial inclusion in the context of the bacterial and host metabolism. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Improving protein delivery of fibroblast growth factor-2 from bacterial inclusion bodies used as cell culture substrates.

    PubMed

    Seras-Franzoso, Joaquin; Peebo, Karl; García-Fruitós, Elena; Vázquez, Esther; Rinas, Ursula; Villaverde, Antonio

    2014-03-01

    Bacterial inclusion bodies (IBs) have recently been used to generate biocompatible cell culture interfaces, with diverse effects on cultured cells such as cell adhesion enhancement, stimulation of cell growth or induction of mesenchymal stem cell differentiation. Additionally, novel applications of IBs as sustained protein delivery systems with potential applications in regenerative medicine have been successfully explored. In this scenario, with IBs gaining significance in the biomedical field, the fine tuning of this functional biomaterial is crucial. In this work, the effect of temperature on fibroblast growth factor-2 (FGF-2) IB production and performance has been evaluated. FGF-2 was overexpressed in Escherichia coli at 25 and 37 °C, producing IBs with differences in size, particle structure and biological activity. Cell culture topographies made with FGF-2 IBs biofabricated at 25 °C showed higher levels of biological activity as well as a looser supramolecular structure, enabling a higher protein release from the particles. In addition, the controlled use of FGF-2 protein particles enabled the generation of functional topographies with multiple biological activities being effective on diverse cell types. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Innovative Self-Cleaning and Biocompatible Polyester Textiles Nano-Decorated with Fe–N-Doped Titanium Dioxide

    PubMed Central

    Nica, Ionela Cristina; Stan, Miruna Silvia; Dinischiotu, Anca; Popa, Marcela; Chifiriuc, Mariana Carmen; Lazar, Veronica; Pircalabioru, Gratiela G.; Bezirtzoglou, Eugenia; Iordache, Ovidiu G.; Varzaru, Elena; Dumitrescu, Iuliana; Feder, Marcel; Vasiliu, Florin; Mercioniu, Ionel; Diamandescu, Lucian

    2016-01-01

    The development of innovative technologies to modify natural textiles holds an important impact for medical applications, including the prevention of contamination with microorganisms, particularly in the hospital environment. In our study, Fe and N co-doped TiO2 nanoparticles have been obtained via the hydrothermal route, at moderate temperature, followed by short thermal annealing at 400 °C. These particles were used to impregnate polyester (PES) materials which have been evaluated for their morphology, photocatalytic performance, antimicrobial activity against bacterial reference strains, and in vitro biocompatibility on human skin fibroblasts. Microscopic examination and quantitative assays have been used to evaluate the cellular morphology and viability, cell membrane integrity, and inflammatory response. All treated PES materials specifically inhibited the growth of Gram-negative bacilli strains after 15 min of contact, being particularly active against Pseudomonas aeruginosa. PES fabrics treated with photocatalysts did not affect cell membrane integrity nor induce inflammatory processes, proving good biocompatibility. These results demonstrate that the treatment of PES materials with TiO2-1% Fe–N particles could provide novel biocompatible fabrics with short term protection against microbial colonization, demonstrating their potential for the development of innovative textiles that could be used in biomedical applications for preventing patients’ accidental contamination with microorganisms from the hospital environment. PMID:28335342

  4. Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

    PubMed Central

    Goeschen, Catrin

    2013-01-01

    Summary Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. PMID:24204400

  5. Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

    PubMed

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-05-21

    Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.

  6. Effect OF NaOH Treatment on Bending Strength Of The Polyester Composite Reinforce By Sugar Palm Fibers

    NASA Astrophysics Data System (ADS)

    Arif Irfai, Mochamad; Wulandari, Diah; Sutriyono; Marsyahyo, Eko

    2018-04-01

    The objective of this research is to investigate the effect of NaOH treatment on bending strength of lamina composite reinforced by sugar palm fiber. To know of mechanism fracture can be done with visual inspection of the fracture surface. The Materials used are random sugar palm fibers that have been in the treatment of NaOH, polyester resin and hardener. Sugar palm fibers after washed and dried then soaked NaOH with a long time soaking 0, 2, 4, 6 and 8 hours. The bending test specimens were produced according to ASTM D 790. All specimens were post cured at 62°C for 4 hours. The Bending test was carried out on a universal testing machine. The SEM analysis has conducted to provide the analysis on interface adhesion between the surfaces of fiber with the matrix. The result shows that polyester composite reinforced by sugar palm fiber has highest bending stress 176.77 N/mm2 for 2 hours of a long time soaking NaOH, the highest flexural strain 0.27 mm for 2 hours of a long time soaking NaOH, elongation 24.05% for 2 hours of a long time soaking NaOH and the highest bending modulus 1.267 GPa for 2 hours of a long time soaking NaOH. Based on the results, it can be concluded that the polyester composite reinforced by sugar palm fiber has the optimum bending properties for a long time soaking 2 hours. The fracture surface shows that the polyester composite reinforced by sugar palm fiber pull out that indicate weakens the bond between fiber and matrix.

  7. Optical, colloidal and biological properties of up-converting nanoparticles embedded in polyester nanocarriers

    NASA Astrophysics Data System (ADS)

    Wawrzyńczyk, Dominika; Kulbacka, Julita; Bazylińska, Urszula

    2017-08-01

    We have investigated the change in optical properties and biocompatibility of up-converting NaYF4 nanoparticles (NPs) upon encapsulation inside the polyester nanocarriers (NCs) stabilized by Crempophor RH40 (CRH40), poly(D,L-lactide) (PLA), Pluronic P123 (P123). NaYF4:Er3+,Yb3+ NPs showed intense green and red emission, and upon encapsulation the increase of red band in respect to green one was observed, with no luminescence lifetime shortening. Obtained NCs showed prolonged colloidal stability and protective effect of the polymer shell simultaneously preserving the high emission efficiency of nanoparticles embedded within the silicon oil (SO) core. Based on emission spectra, kinetic measurements and cytotoxicity studies upon human malignant melanoma Me45 cell line we have shown the advantages of using polyester NCs as containers for the up-converting NPs. Due to the possibility of co-encapsulation of photosensitizers the obtained nanocarriers showed potential for application in theranostics.

  8. The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight.

    PubMed

    Truong, Vi Khanh; Stefanovic, Miljan; Maclaughlin, Shane; Tobin, Mark; Vongsvivut, Jitraporn; Al Kobaisi, Mohammad; Crawford, Russell J; Ivanova, Elena P

    2016-10-11

    Corrosion of metallic surfaces is prevalent in the environment and is of great concern in many areas, including the military, transport, aviation, building and food industries, amongst others. Polyester and coatings containing both polyester and silica nanoparticles (SiO2NPs) have been widely used to protect steel substrata from corrosion. In this study, we utilized X-ray photoelectron spectroscopy, attenuated total reflection infrared micro-spectroscopy, water contact angle measurements, optical profiling and atomic force microscopy to provide an insight into how exposure to sunlight can cause changes in the micro- and nanoscale integrity of the coatings. No significant change in surface micro-topography was detected using optical profilometry, however, statistically significant nanoscale changes to the surface were detected using atomic force microscopy. Analysis of the X-ray photoelectron spectroscopy and attenuated total reflection infrared micro-spectroscopy data revealed that degradation of the ester groups had occurred through exposure to ultraviolet light to form COO·, -H2C·, -O·, -CO· radicals. During the degradation process, CO and CO2 were also produced.

  9. Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites

    NASA Technical Reports Server (NTRS)

    Lark, R. F.; Chamis, C. C.

    1984-01-01

    Transverse filament tape (TFT) fiberglass/epoxy and TFT polyester composites intended for low cost wind turbine blade fabrication have been subjected to static and cyclic load behavior tests whose results are presently evaluated on the basis of an integrated hygrothermomechanical response theory. Laminate testing employed simulated filament winding procedures. The results obtained show that the predicted hygrothermomechanical environmental effects on TFT composites are in good agreement with measured data for various properties, including fatigue at different R-ratio values.

  10. Observation of hairpin defects in a nematic main-chain polyester

    NASA Astrophysics Data System (ADS)

    Li, M. H.; Brûlet, A.; Davidson, P.; Keller, P.; Cotton, J. P.

    1993-04-01

    The conformation of a main-chain liquid crystalline polyester in its oriented nematic phase has been determined by small-angle neutron scattering. The data are fitted by a model of rigid cylinder with orientational fluctuations. For a low degree of polymerization (~9) the chain is almost completely elongated in the direction of the nematic field. For a polymer 3 times longer, the existence of two hairpins is shown at high temperature; this number decreases with decreasing temperature.

  11. Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

    NASA Astrophysics Data System (ADS)

    Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

    2018-04-01

    The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

  12. Purification of recombinant ovalbumin from inclusion bodies of Escherichia coli.

    PubMed

    Upadhyay, Vaibhav; Singh, Anupam; Panda, Amulya K

    2016-01-01

    Recombinant ovalbumin expressed in bacterial host is essentially free from post-translational modifications and can be useful in understanding the structure-function relationship of the protein. In this study, ovalbumin was expressed in Escherichia coli in the form of inclusion bodies. Ovalbumin inclusion bodies were solubilized using urea and refolded by decreasing the urea concentration by dilution. Refolded protein was purified by anion exchange chromatography. Overall recovery of purified recombinant ovalbumin from inclusion bodies was about 30% with 98% purity. Purified recombinant ovalbumin was characterized by mass spectrometry, circular dichroism and fluorescence spectroscopy. Recombinant ovalbumin was shown to be resistant to trypsin using protease resistance assay. This indicated proper refolding of ovalbumin from inclusion bodies of E. coli. This method provides a simple way of producing ovalbumin free of post-translational modifications. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Investigation of the phase morphology of bacterial PHA inclusion bodies by contrast variation SANS

    NASA Astrophysics Data System (ADS)

    Russell, R. A.; Holden, P. J.; Garvey, C. J.; Wilde, K. L.; Hammerton, K. M.; Foster, L. J.

    2006-11-01

    Under growth-limiting conditions, many bacteria are able to metabolise excess organic acids into polyhydroxyalkanoates (PHA) and store these polymers as intracellular inclusions until the return of favourable conditions. Various models have been proposed for the macromolecular organisation of the boundary layer surrounding the polymer, and contrast-variation small-angle neutron scattering (SANS) was used to study its organisation. Inclusions formed by Pseudomonas oleovorans under hydrogenating conditions showed lowest scattering intensity at ca. 20% D 2O. The inclusions consist of protein and membrane lipids in the boundary layer and polyhydroxyoctanoate (lipid) in the inclusion body. At 20% D 2O the contributions of lipids were contrast matched with the solvent, indicating that lipids contributed the bulk of the scattering intensity observed at other D 2O/H 2O ratios. These results are inconsistent with a model of the boundary layer which proposed outer and inner layers of crystalline protein lattice sandwiching a membrane lipid membrane layer [E.S. Stuart, R.W. Lenz, R.C. Fuller, Can J Microbiol 41(Suppl 1) (1995) 84-93], and is more consistent with a model consisting of a lipid monolayer containing embedded proteins [U. Pieper-furst, M.H. Madkour, F. Mayer, A. Steinbuchel, J. Bacteriol. 176 (1994) 4328-4337.] By altering the H/D content of the precursors, we were able to collect SANS data from preparations of both deuterated and H/D copolymer inclusions, where initial PHA produced was hydrogenated followed by deuteration. Deuterated inclusions showed minimum intensity above 90% D 2O/H 2O whereas the sequentially produced copolymer (assumed to be in a core/shell arrangement) displayed minimum scattering some 20% lower, which is consistent with the increased hydrogenation of the boundary layer expected from its synthesis during supply of hydrogenated followed by deuterated precursors.

  14. Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

    PubMed Central

    Carrión, Francisco; Montalbán, Laura; Real, Julia I.

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior. PMID:25243213

  15. Mechanical and physical properties of polyester polymer concrete using recycled aggregates from concrete sleepers.

    PubMed

    Carrión, Francisco; Montalbán, Laura; Real, Julia I; Real, Teresa

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior.

  16. A microbial factory for lactate-based polyesters using a lactate-polymerizing enzyme

    PubMed Central

    Taguchi, Seiichi; Yamada, Miwa; Matsumoto, Ken'ichiro; Tajima, Kenji; Satoh, Yasuharu; Munekata, Masanobu; Ohno, Katsuhiro; Kohda, Katsunori; Shimamura, Takashi; Kambe, Hiromi; Obata, Shusei

    2008-01-01

    Polylactate (PLA) is synthesized as a representative bio-based polyester by the chemo-bio process on the basis of metal catalyst-mediated chemical polymerization of lactate (LA) supplied by microbial fermentation. To establish the one-step microbial process for synthesis of LA-based polyesters, we explored whether polyhydroxyalkanoate (PHA) synthase would exhibit polymerizing activity toward a LA-coenzyme A (CoA), based on the fact that PHA monomeric constituents, especially 3-hydroxybutyrate (3HB), are structurally analogous to LA. An engineered PHA synthase was discovered as a candidate by a two-phase in vitro polymerization system previously developed. An LA-CoA producing Escherichia coli strain with a CoA transferase gene was constructed, and the generation of LA-CoA was demonstrated by capillary electrophoresis/MS analysis. Next, when the engineered PHA synthase gene was introduced into the resultant recombinant strain, we confirmed the one-step biosynthesis of the LA-incorporated copolyester, P(6 mol% LA-co-94 mol% 3HB), with a number-average molecular weight of 1.9 × 105, as revealed by gel permeation chromatography, gas chromatography/MS, and NMR. PMID:18978031

  17. [A novel method based on Y-shaped cotton-polyester thread microfluidic channel].

    PubMed

    Wang, Lu; Shi, Yan-ru; Yan, Hong-tao

    2014-08-01

    A novel method based on Y-shaped microfluidic channel was firstly proposed in this study. The microfluidic channel was made of two cotton-polyester threads based on the capillary effect of cotton-polyester threads for the determination solutions. A special device was developed to fix the Y-shaped microfluidic channel by ourselves, through which the length and the tilt angle of the channel can be adjusted as requested. The spectrophotometry was compared with Scan-Adobe Photoshop software processing method. The former had a lower detection limit while the latter showed advantages in both convenience and fast operations and lower amount of samples. The proposed method was applied to the determination of nitrite. The linear ranges and detection limits are 1.0-70 micromol x L(-1), 0.66 micromol x L(-1) (spectrophotometry) and 50-450 micromol x L(-1), 45.10 micromol x L(-1) (Scan-Adobe Photoshop software processing method) respectively. This method has been successfully used to the determination of nitrite in soil samples and moat water with recoveries between 96.7% and 104%. It was proved that the proposed method was a low-cost, rapid and convenient analytical method with extensive application prospect.

  18. The Inclusive Classroom: How Inclusive Is Inclusion?

    ERIC Educational Resources Information Center

    Reid, Claudette M.

    2010-01-01

    This paper presents the position that inclusion is limited; inclusion does not go far enough. The inclusive classroom has been assessed to be of benefit both to the teacher and student. There are, however, limits set on inclusion. In most classrooms only children with learning disability are included omitting those with severe disabilities,…

  19. The usefulness of a stretch-polyester pouch to encase implanted pacemakers and defibrillators.

    PubMed

    Parsonnet, V; Bernstein, A D; Neglia, D; Omar, A

    1994-12-01

    This study was undertaken to assess the effects of enclosing permanent pacemaker and ICD pulse generators in a stretch-polyester pouch prior to implantation. Follow-up of 223 patients with oversized pacemakers and with ICDs and 344 with standard-sized pacemaker pulse generators showed that the pouch was effective in decreasing the frequency of pulse generator migration and extrusion.

  20. Degradation of polyester polyurethane by a newly isolated soil bacterium, Bacillus subtilis strain MZA-75.

    PubMed

    Shah, Ziaullah; Krumholz, Lee; Aktas, Deniz Fulya; Hasan, Fariha; Khattak, Mutiullah; Shah, Aamer Ali

    2013-11-01

    A polyurethane (PU) degrading bacterial strain MZA-75 was isolated from soil through enrichment technique. The bacterium was identified through 16S rRNA gene sequencing, the phylogenetic analysis indicated the strain MZA-75 belonged to genus Bacillus having maximum similarity with Bacillus subtilis strain JBE0016. The degradation of PU films by strain MZA-75 in mineral salt medium (MSM) was analyzed by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FT-IR) and gel permeation chromatography (GPC). SEM revealed the appearance of widespread cracks on the surface. FTIR spectrum showed decrease in ester functional group. Increase in polydispersity index was observed in GPC, which indicates chain scission as a result of microbial treatment. CO2 evolution and cell growth increased when PU was used as carbon source in MSM in Sturm test. Increase in both cell associated and extracellular esterases was observed in the presence of PU indicated by p-Nitrophenyl acetate (pNPA) hydrolysis assay. Analysis of cell free supernatant by gas chromatography-mass spectrometry (GC-MS) revealed that 1,4-butanediol and adipic acid monomers were produced. Bacillus subtilis strain MZA-75 can degrade the soft segment of polyester polyurethane, unfortunately no information about the fate of hard segment could be obtained. Growth of strain MZA-75 in the presence of these metabolites indicated mineralization of ester hydrolysis products into CO2 and H2O.

  1. Effects of dietary inclusion of silymarin on performance, intestinal morphology and ileal bacterial count in aflatoxin-challenged broiler chicks.

    PubMed

    Jahanian, E; Mahdavi, A H; Asgary, S; Jahanian, R

    2017-10-01

    This study was conducted to investigate the effect of dietary supplementation of silymarin on performance, jejunal morphology and ileal bacterial population in broiler chicks intoxicated with a mix of aflatoxins. A total of three hundred thirty six 7-day-old Ross broiler chicks were randomly distributed between seven experimental groups with four replicates of 12 birds each. Experimental treatments consisted of a control group (unchallenged), and a 2 × 3 factorial arrangement, including two aflatoxin levels (0.5 and 2 ppm) and three levels of silymarin (0, 500 and 1000 ppm). Birds were challenged with a mix of aflatoxins from 7 to 28 days of age. Results showed that increasing aflatoxin level resulted in decreased average daily feed intake (ADFI) and weight gain (ADWG), consequently impaired feed conversion ratio (FCR) throughout the trial period. Dietary supplementation of silymarin resulted in the marked increases in ADFI and ADWG, and improved FCR values in aflatoxin-challenged chicks. Ileal bacterial populations at days 28 and 42 of age were increased by incremental levels of aflatoxins. On the other hand, dietary silymarin supplementation suppressed ileal populations of Escherichia coli, Salmonella, Klebsiella and total negative bacteria in aflatoxicated birds. Increase in dietary aflatoxin level resulted in the decreased villi height, villi height-to-crypt depth ratio (VH:CD), villi surface area and apparent villi absorptive area, while it increased crypt depth, goblet cell count and lymphoid follicular diameter. Feeding silymarin at the level of 1000 ppm increased villi height and VH:CD in aflatoxicated birds. Present results indicate that dietary inclusion of silymarin could improve performance by suppressing ileal bacteria and enhancing absorptive surface area in aflatoxin-challenged broiler chicks. Journal of Animal Physiology and Animal Nutrition © 2017 Blackwell Verlag GmbH.

  2. New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes.

    PubMed

    Díaz, Angélica; del Valle, Luis J; Tugushi, David; Katsarava, Ramaz; Puiggalí, Jordi

    2015-01-01

    Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(α-aminoacyl)-α,ω-diol-diester monomer. The polymer having L-leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and polyhexamethylenebiguanide) and enzymes (e.g. α-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Loading of chitosan - Nano metal oxide hybrids onto cotton/polyester fabrics to impart permanent and effective multifunctions.

    PubMed

    Ibrahim, Nabil A; Eid, Basma M; El-Aziz, Eman Abd; Elmaaty, Tarek M Abou; Ramadan, Shaimaa M

    2017-12-01

    New and durable multifunctional properties of cotton/polyester blended fabrics were developed through loading of chitosan (Cs) and various metal oxide nanoparticles (MONPs) namely ZnO, TiO 2 , and SiO 2 onto fabric surface using citric acid/Sodium hypophosphite for ester-crosslinking and creating new anchoring and binding sites, COOH groups, onto the ester-crosslinked fabrics surface. The surface morphology and the presence of active ingredients (Cs & MONPs) onto selected - coated fabric samples were analyzed by SEM images and confirmed by EDS spectrums. The influence of various finishing formulations on some performance and functional properties such as wettability, antibacterial activity, UV-protection, self-cleaning, resiliency and durability to wash were studied. The obtained results revealed that the extent of improvement in the imparted functional properties is governed by type of loaded-hybrid and follows the decreasing order: Cs-TiO 2 NPs>Cs-ZnONPs>SiO 2 NP s >Cs alone, as well as kind of substrate cotton/polyester (65/35)>cotton/polyester (50/50). Moreover, after 15 washing cycles, the durability of the imparted functional properties of Cs/TiO 2 NP s - loaded substrates marginally decreased indicating the strong fixation of the hybrid components onto the ester-crosslinked substrates. The obtained bioactive multifunctional textiles can be used for producing eco-friendly protective textile materials for numerous applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. California State Implementation Plan; San Diego County Air Pollution Control District; VOC Emissions from Polyester Resin Operations

    EPA Pesticide Factsheets

    EPA is taking final action to approve revisions to the San Diego County Air Pollution Control District (SDCAPCD) portion of the California SIP concerning volatile organic compound (VOC) emissions from polyester resin operations.

  5. The influence of solvent processing on polyester bioabsorbable polymers.

    PubMed

    Manson, Joanne; Dixon, Dorian

    2012-01-01

    Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

  6. Degradation Mechanisms of Poly(ester urethane) Elastomer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Edgar, Alexander S.

    This report describes literature regarding the degradation mechanisms associated with a poly(ester urethane) block copolymer, Estane® 5703 (Estane), used in conjunction with Nitroplasticizer (NP), and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, also known as high molecular weight explosive (HMX) to produce polymer bonded explosive PBX 9501. Two principal degradation mechanisms are reported: NO2 oxidative reaction with the urethane linkage resulting in crosslinking and chain scission events, and acid catalyzed hydrolysis of the ester linkage. This report details future work regarding this PBX support system, to be conducted in late 2017 and 2018 at Engineered Materials Group (MST-7), Materials Science and Technology Division, Los Alamos Nationalmore » Laboratory. This is the first of a series of three reports on the degradation processes and trends of the support materials of PBX 9501.« less

  7. Red blood cell transport mechanisms in polyester thread-based blood typing devices.

    PubMed

    Nilghaz, Azadeh; Ballerini, David R; Guan, Liyun; Li, Lizi; Shen, Wei

    2016-02-01

    A recently developed blood typing diagnostic based on a polyester thread substrate has shown great promise for use in medical emergencies and in impoverished regions. The device is easy to use and transport, while also being inexpensive, accurate, and rapid. This study used a fluorescent confocal microscope to delve deeper into how red blood cells were behaving within the polyester thread-based diagnostic at the cellular level, and how plasma separation could be made to visibly occur on the thread, making it possible to identify blood type in a single step. Red blood cells were stained and the plasma phase dyed with fluorescent compounds to enable them to be visualised under the confocal microscope at high magnification. The mechanisms uncovered were in surprising contrast with those found for a similar, paper-based method. Red blood cell aggregates did not flow over each other within the thread substrate as expected, but suffered from a restriction to their flow which resulted in the chromatographic separation of the RBCs from the liquid phase of the blood. It is hoped that these results will lead to the optimisation of the method to enable more accurate and sensitive detection, increasing the range of blood systems that can be detected.

  8. Comparison of three distinct clean air suits to decrease the bacterial load in the operating room: an observational study.

    PubMed

    Kasina, Piotr; Tammelin, Ann; Blomfeldt, Anne-Marie; Ljungqvist, Bengt; Reinmüller, Berit; Ottosson, Carin

    2016-01-01

    Lowering air-borne bacteria counts in the operating room is essential in prevention of surgical site infections in orthopaedic joint replacement surgery. This is mainly achieved by decreasing bacteria counts through dilution, with appropriate ventilation and by limiting the bacteria carrying skin particles, predominantly shed by the personnel. The aim of this study was to investigate if a single use polypropylene clothing system or a reusable polyester clothing system could offer similar air quality in the operating room as a mobile laminar airflow device-assisted reusable cotton/polyester clothing system. Prospective observational study design, comparing the performance of three Clean Air Suits by measuring Colony Forming Units (CFU)/m(3) of air during elective hip and knee arthroplasties, performed at a large university-affiliated hospital. The amount of CFU/m(3) of air was measured during 37 operations of which 13 were performed with staff dressed in scrub suits made of a reusable mixed material (69 % cotton, 30 % polyester, 1 % carbon fibre) accompanied by two mobile laminar airflow units. During 24 procedures no mobile laminar airflow units were used, 13 with staff using a reusable olefin fabric clothing (woven polypropylene) and 11 with staff dressed in single-use suits (non-woven spunbonded polypropylene). Air from the operating field was sampled through a filter, by a Sartorius MD8, and bacterial colonies were counted after incubation. There were 6-8 measurements from each procedure, in total 244 measurements. Statistical analysis was performed by Mann-Whitney U-test. The single-use polypropylene suit reduced the amount of CFU/m(3) to a significantly lower level than both other clothing systems. Single-use polypropylene clothing systems can replace mobile laminar airflow unit-assisted reusable mixed material-clothing systems. Measurements in standardized laboratory settings can only serve as guidelines as environments in real operation settings present a

  9. Dry entrapment of enzymes by epoxy or polyester resins hardened on different solid supports.

    PubMed

    Barig, Susann; Funke, Andreas; Merseburg, Andrea; Schnitzlein, Klaus; Stahmann, K-Peter

    2014-06-10

    Embedding of enzymes was performed with epoxy or polyester resin by mixing in a dried enzyme preparation before polymerization was started. This fast and low-cost immobilization method produced enzymatically active layers on different solid supports. As model enzymes the well-characterized Thermomyces lanuginosus lipase and a new threonine aldolase from Ashbya gossypii were used. It was shown that T. lanuginosus lipase recombinantly expressed in Aspergillus oryzae is a monomeric enzyme with a molecular mass of 34kDa, while A. gossypii threonine aldolase expressed in Escherichia coli is a pyridoxal-5'-phosphate binding homotetramer with a mass of 180kDa. The enzymes were used freeze dried, in four different preparations: freely diffusing, adsorbed on octyl sepharose, as well as cross-linked enzyme aggregates or as suspensions in organic solvent. They were mixed with standard two-component resins and prepared as layers on solid supports made of different materials e.g. metal, glass, polyester. Polymerization led to encapsulated enzyme preparations showing activities comparable to literature values. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. The role of the substrate in micro-scale scratching of epoxy-polyester films

    NASA Astrophysics Data System (ADS)

    Barletta, M.; Gisario, A.

    2011-02-01

    The present investigation analyzes the deformation response of electrostatically sprayed epoxy-polyester powder coatings by 'in situ' micro-mechanical tests. The characterization of the performance of the coatings was carried out by micro-scale scratching, by varying the indenter type, the applied load and the sliding speed. The tests were carried out on polymeric coatings deposited on as-received, micro and macro-corrugated AISI 304 stainless steel substrates and 'rigidly adhered' to them. Further tests were performed on 'free-standing' coatings, that is, on the as-received metal substrates pre-coated with an intermediate layer of silicon-based heat curable release coating. Experimental data allow us to evaluate the influence of the contact conditions between substrate and indenter and the role of the loading conditions on the scratch and penetration resistance of the epoxy-polyester coatings. The different responses of the polymeric coatings when deposited on untreated or pre-treated substrates as well as on an intermediate layer of release coating, contribute to a better understanding of the intrinsic roles of the polymeric material and substrate as well as the influence of the interfacial adhesion between coating and substrate.

  11. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

    USDA-ARS?s Scientific Manuscript database

    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

  12. 78 FR 17637 - Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... staple fiber (PSF) from Taiwan. The period of review (POR) is May 1, 2011, through April 30, 2012. The.... DATES: Effective Date: March 22, 2013. FOR FURTHER INFORMATION CONTACT: Bryan Hansen or Minoo Hatten, AD...

  13. Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy- Efficient Wood-Plastic Composites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thompson, David N.; Emerick, Robert W.; England, Alfred B.

    In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. We have demonstrated that biopolymers (polyhydroxyalkanoates, PHA) can be successfully produced from wood pulping waste streams and that viable wood fiber reinforced thermoplastic compositemore » products can be produced from these materials. The results show that microbial polyester (PHB in this study) can be extruded together with wastewater-derived cell mass and wood flour into deck products having performance properties comparable to existing commercial HDPE/WF composite products. This study has thus proven the underlying concept that the microbial polyesters produced from waste effluents can be used to make cost-effective and energy-efficient wood-plastic composites. The cost of purified microbial polyesters is about 5-20 times that of HDPE depending on the cost of crude oil, due to high purification (40%), carbon substrate (40%) and sterilized fermentation (20%) costs for the PHB. Hence, the ability to produce competitive and functional composites with unpurified PHA-biomass mixtures from waste carbon sources in unsterile systems—without cell debris removal—is a significant step forward in producing competitive value-added structural composites from forest products residuals using a biorefinery approach. As demonstrated in the energy and waste analysis for the project, significant energy savings and waste reductions can also be realized using this approach. We recommend that the next step for

  14. Photo and biocatalytic activities along with UV protection properties on polyester fabric through green in-situ synthesis of cauliflower-like CuO nanoparticles.

    PubMed

    Rezaie, Ali Bashiri; Montazer, Majid; Rad, Mahnaz Mahmoudi

    2017-11-01

    In this paper, a facile environmentally friendly method is introduced for in-situ synthesis and fabrication of cauliflower-like CuO nanoparticles on the polyester fabric to produce photo and biocatalytic activities with UV protection properties on polyester fabric. The ash of burnt leaves and stems of Seidlitzia rosmarinus plant called Keliab was used as a natural and nontoxic alkaline source for simultaneous synthesis of CuO nanoparticles and surface modification of polyester without using any other compounds. The images of field-emission scanning electron microscopy, patterns of energy-dispersive spectroscopy, UV-visible spectrum and X-ray diffraction confirmed successful synthesis and loading of CuO nanoparticles on the polyester fabric. The treated fabrics showed very good antibacterial activities toward two pathogen bacteria including Staphylococcus aureus as a Gram-positive and Escherichia coli as a Gram-negative bacteria with no adverse effects on human dermal fibroblasts based on MTT test. The treated fabrics confirmed significant photocatalytic activity for degradation of methylene blue under sunlight, self-cleaning properties under UV light and also UV protection properties. Further a colorant effect along with an improvement in the wettability and mechanical properties of the treated fabrics were indicated. Overall, this method can be applied as a clean route for producing photo and bio active textiles protecting against UV irradiation. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Chlamydia trachomatis Intercepts Golgi-Derived Sphingolipids through a Rab14-Mediated Transport Required for Bacterial Development and Replication

    PubMed Central

    Capmany, Anahí; Damiani, María Teresa

    2010-01-01

    Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation. PMID:21124879

  16. Chlamydia trachomatis intercepts Golgi-derived sphingolipids through a Rab14-mediated transport required for bacterial development and replication.

    PubMed

    Capmany, Anahí; Damiani, María Teresa

    2010-11-22

    Chlamydia trachomatis are obligate intracellular bacteria that survive and replicate in a bacterial-modified phagosome called inclusion. As other intracellular parasites, these bacteria subvert the phagocytic pathway to avoid degradation in phagolysosomes and exploit trafficking pathways to acquire both energy and nutrients essential for their survival. Rabs are host proteins that control intracellular vesicular trafficking. Rab14, a Golgi-related Rab, controls Golgi to endosomes transport. Since Chlamydia establish a close relationship with the Golgi apparatus, the recruitment and participation of Rab14 on inclusion development and bacteria growth were analyzed. Time course analysis revealed that Rab14 associated with inclusions by 10 h post infection and was maintained throughout the entire developmental cycle. The recruitment was bacterial protein synthesis-dependent but independent of microtubules and Golgi integrity. Overexpression of Rab14 dominant negative mutants delayed inclusion enlargement, and impaired bacteria replication as determined by IFU. Silencing of Rab14 by siRNA also decreased bacteria multiplication and infectivity. By electron microscopy, aberrant bacteria were observed in cells overexpressing the cytosolic negative Rab14 mutant. Our results showed that Rab14 facilitates the delivery of sphingolipids required for bacterial development and replication from the Golgi to chlamydial inclusions. Novel anti-chlamydial therapies could be developed based on the knowledge of how bacteria subvert host vesicular transport events through Rabs manipulation.

  17. Protein recovery from inclusion bodies of Escherichia coli using mild solubilization process.

    PubMed

    Singh, Anupam; Upadhyay, Vaibhav; Upadhyay, Arun Kumar; Singh, Surinder Mohan; Panda, Amulya Kumar

    2015-03-25

    Formation of inclusion bodies in bacterial hosts poses a major challenge for large scale recovery of bioactive proteins. The process of obtaining bioactive protein from inclusion bodies is labor intensive and the yields of recombinant protein are often low. Here we review the developments in the field that are targeted at improving the yield, as well as quality of the recombinant protein by optimizing the individual steps of the process, especially solubilization of the inclusion bodies and refolding of the solubilized protein. Mild solubilization methods have been discussed which are based on the understanding of the fact that protein molecules in inclusion body aggregates have native-like structure. These methods solubilize the inclusion body aggregates while preserving the native-like protein structure. Subsequent protein refolding and purification results in high recovery of bioactive protein. Other parameters which influence the overall recovery of bioactive protein from inclusion bodies have also been discussed. A schematic model describing the utility of mild solubilization methods for high throughput recovery of bioactive protein has also been presented.

  18. One-step affinity tag purification of full-length recombinant human AP-1 complexes from bacterial inclusion bodies using a polycistronic expression system

    PubMed Central

    Wang, Wei-Ming; Lee, A-Young; Chiang, Cheng-Ming

    2008-01-01

    The AP-1 transcription factor is a dimeric protein complex formed primarily between Jun (c-Jun, JunB, JunD) and Fos (c-Fos, FosB, Fra-1, Fra-2) family members. These distinct AP-1 complexes are expressed in many cell types and modulate target gene expression implicated in cell proliferation, differentiation, and stress responses. Although the importance of AP-1 has long been recognized, the biochemical characterization of AP-1 remains limited in part due to the difficulty in purifying full-length, reconstituted dimers with active DNA-binding and transcriptional activity. Using a combination of bacterial coexpression and epitope-tagging methods, we successfully purified all 12 heterodimers (3 Jun × 4 Fos) of full-length human AP-1 complexes as well as c-Jun/c-Jun, JunD/JunD, and c-Jun/JunD dimers from bacterial inclusion bodies using one-step nickel-NTA affinity tag purification following denaturation and renaturation of coexpressed AP-1 subunits. Coexpression of two constitutive components in a dimeric AP-1 complex helps stabilize the proteins when compared with individual protein expression in bacteria. Purified dimeric AP-1 complexes are functional in sequence-specific DNA binding, as illustrated by electrophoretic mobility shift assays and DNase I footprinting, and are also active in transcription with in vitro-reconstituted human papillomavirus (HPV) chromatin containing AP-1-binding sites in the native configuration of HPV nucleosomes. The availability of these recombinant full-length human AP-1 complexes has greatly facilitated mechanistic studies of AP-1-regulated gene transcription in many biological systems. PMID:18329890

  19. One-pot preparation of unsaturated polyester nanocomposites containing functionalized graphene sheets via a novel solvent-exchange method

    USDA-ARS?s Scientific Manuscript database

    This paper reports a convenient one-pot method integrating a novel solvent-exchange method into in situ melt polycondensation to fabricate unsaturated polyester nanocomposites containing functionalized graphene sheets (FGS). A novel solvent-exchange method was first developed to prepare graphene oxi...

  20. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amide)s

    PubMed Central

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-01-01

    Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed. PMID:24776758

  1. Novel polyester/SiO2 nanocomposite membranes: Synthesis, properties and morphological studies

    NASA Astrophysics Data System (ADS)

    Ahmadizadegan, Hashem; Esmaielzadeh, Sheida

    2018-06-01

    In this paper, a new type of soluble polyester/silica (PE/SiO2) hybrid was prepared by the ultrasonic irradiation process. The coupling agent γ-glycidyloxypropyltrimethoxysilane (GOTMS) was chosen to enhance the compatibility between the polyester (PE) and silica (SiO2). Furthermore, the effects of the coupling agent on the morphologies and properties of the PE/SiO2 hybrids were investigated using UV-vis and FT-IR spectroscopies and FE-SEM. The densities and solubilities of the PE/SiO2 hybrids were also measured. The results show that the size of the silica particle was markedly reduced by the introduction of the coupling agent, which made the PE/SiO2 hybrid films become transparent. Furthermore, thermal stability, residual solvent in the membrane film and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). The effects of SiO2 nanoparticles on the glass transition temperature (Tg) of the prepared nanocomposites were studied by differential scanning calorimetry (DSC). Moreover, their mechanical properties were also characterized. It can be observed that the Young's moduli (E) of the hybrid films increase linearly with the silica content. The results obtained from gas permeation experiments with a constant pressure setup showed that adding SiO2 nanoparticles to the polymeric membrane structure increased the permeability of the membranes.

  2. Aliphatic hyperbranched polyester: A new building block in the construction of multifunctional nanoparticles and nanocomposites**

    PubMed Central

    Santra, Santimukul; Kaittanis, Charalambos; Perez, J. Manuel

    2009-01-01

    Herein we report the design and synthesis of multifunctional hyperbranched polyester-based nanoparticles and nanocomposites with properties ranging from magnetic, fluorescence, antioxidant and X-ray contrast. The fabrication of these nanostructures was achieved using a novel aliphatic and biodegradable hyperbranched polyester (HBPE) synthesized from readily available diethylmalonate. The polymer’s globular structure with functional surface carboxylic groups and hydrophobic cavities residing in the polymer’s interior allows for the formation of multifunctional polymeric nanoparticles, which are able to encapsulate a diversity of hydrophobic cargos. Via simple surface chemistry modifications, the surface carboxylic acid groups were modified to yield nanoparticles with a variety of surface functionalizations, such as amino, azide and propargyl groups, which mediated the conjugation of small molecules. This capability achieved the engineering of the HBPE nanoparticle surface for specific cell internalization studies and the formation of nanoparticle assemblies for the creation of novel nanocomposites that retained, and in some cases enhanced, the properties of the parental nanoparticle building blocks. Considering these results, the HBPE polymer, nanoparticles and composites should be ideal for biomedical, pharmaceutical, nanophotonics and material applications. PMID:19957939

  3. Influence of magnetite, ilmenite and boron carbide on radiation attenuation of polyester composites

    NASA Astrophysics Data System (ADS)

    El-Sarraf, M. A.; El-Sayed Abdo, A.

    2013-07-01

    This work is concerned with studying polyester/ magnetite CUP/Mag (ρ=2.75 g cm-3) and polyester/ ilmenite CUP/Ilm (ρ=2.7 g cm-3) composites for shielding of medical facilities, laboratory hot cells and for various purposes. Mechanical and physical properties such as compressive, flexural and impact strengths, as well as, a.c. electrical conductivity, specific heat, water absorption and porosity have been performed to evaluate the composite capabilities for radiation shielding. A collimated beam from fission 252Cf (100 µg) neutron source and neutron-gamma spectrometer with stilbene scintillator based on the zero cross over method and pulse shape discrimination (P.S.D.) technique have been used to measure neutron and gamma ray spectra. Fluxes of thermal neutrons have been measured using the BF3 detector and thermal neutron detection system. The attenuation parameters, namely macroscopic effective removal cross-section ΣR, total attenuation coefficient µ and macroscopic cross-section Σ of fast neutrons, gamma rays and thermal neutrons respectively have been evaluated. Theoretical calculations using MCNP-4C2 code was used to calculate ΣR,μ and Σ. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ΣR. Measured and calculated results were compared and reasonable agreement was found.

  4. Inhalable Andrographolide-β-cyclodextrin Inclusion Complexes for Treatment of Staphylococcus aureus Pneumonia by Regulating Immune Responses.

    PubMed

    Zhang, Tongtong; Zhu, Lifei; Li, Miao; Hu, Yuzhen; Zhang, Erfeng; Jiang, Qingcheng; Han, Guang; Jin, Yiguang

    2017-05-01

    Bacterial pneumonia is a serious disease with high mortality if no appropriate and immediate therapy is available. Andrographolide (AG) is an anti-inflammatory agent extracted from a traditional Chinese herb andrographis paniculata. Oral AG tablets and pills are clinically applied for treatment of upper respiratory tract infections. However, the low solubility and bioavailability of AG lead to high doses and long-term therapy. Here we developed an andrographolide-β-cyclodextrin inclusion complex (AG-β-CD) for inhalation therapy of Staphylococcus aureus pneumonia. AG-β-CD was identified with X-ray diffraction and FT-IR. Surprisingly, both AG-β-CD and AG showed little in vitro anti-S. aureus activity. However, pulmonary delivery of AG, AG-β-CD, or penicillin had significant anti-S. aureus pneumonia effects. Leukocytes, neutrophils, white blood cells, total proteins, TNF-α, IL-6, NF-κB p65 expression, and bacterial colonies in the bronchoalveolar lavage fluids were detected. Pulmonary delivery of AG and AG-β-CD led to bacterial inhibition and inflammation alleviation by regulating immune responses, while penicillin only killed bacteria without significant immune regulation. Moreover, the antipneumonia activity of AG-β-CD was much higher than that of AG, probably resulting from locally accelerated AG dissolution due to β-CD inclusion. The aerodynamic diameter of AG-β-CD powders was 2.03 μm, suitable for pulmonary delivery. Inhalable AG-β-CD is a promising antibacterial and anti-inflammatory medicine for the treatment of S. aureus pneumonia by regulating immune responses, and the effect is enhanced by β-CD inclusion. AG and its formulations might be potent weapons against the resistant bacterial pneumonia due to their specific mechanism in the future.

  5. The establishment and external validation of NIR qualitative analysis model for waste polyester-cotton blend fabrics.

    PubMed

    Li, Feng; Li, Wen-Xia; Zhao, Guo-Liang; Tang, Shi-Jun; Li, Xue-Jiao; Wu, Hong-Mei

    2014-10-01

    A series of 354 polyester-cotton blend fabrics were studied by the near-infrared spectra (NIRS) technology, and a NIR qualitative analysis model for different spectral characteristics was established by partial least squares (PLS) method combined with qualitative identification coefficient. There were two types of spectrum for dying polyester-cotton blend fabrics: normal spectrum and slash spectrum. The slash spectrum loses its spectral characteristics, which are effected by the samples' dyes, pigments, matting agents and other chemical additives. It was in low recognition rate when the model was established by the total sample set, so the samples were divided into two types of sets: normal spectrum sample set and slash spectrum sample set, and two NIR qualitative analysis models were established respectively. After the of models were established the model's spectral region, pretreatment methods and factors were optimized based on the validation results, and the robustness and reliability of the model can be improved lately. The results showed that the model recognition rate was improved greatly when they were established respectively, the recognition rate reached up to 99% when the two models were verified by the internal validation. RC (relation coefficient of calibration) values of the normal spectrum model and slash spectrum model were 0.991 and 0.991 respectively, RP (relation coefficient of prediction) values of them were 0.983 and 0.984 respectively, SEC (standard error of calibration) values of them were 0.887 and 0.453 respectively, SEP (standard error of prediction) values of them were 1.131 and 0.573 respectively. A series of 150 bounds samples reached used to verify the normal spectrum model and slash spectrum model and the recognition rate reached up to 91.33% and 88.00% respectively. It showed that the NIR qualitative analysis model can be used for identification in the recycle site for the polyester-cotton blend fabrics.

  6. Repair of osteochondral defects with hyaluronan- and polyester-based scaffolds.

    PubMed

    Solchaga, Luis A; Temenoff, Johnna S; Gao, Jizong; Mikos, Antonios G; Caplan, Arnold I; Goldberg, Victor M

    2005-04-01

    The natural repair of osteochondral defects can be enhanced with biocompatible, biodegradable materials that support the repair process. It is our hypothesis that hyaluronan-based scaffolds are superior to synthetic scaffolds because they provide biological cues. We tested this thesis by comparing two hyaluronan-based scaffolds [auto cross-linked polysaccharide polymer (ACP) and HYAFF-11] to polyester-based scaffolds [poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA)] with similar pore size, porosity and degradation times. Fifty-four rabbits received bilateral osteochondral defects. One defect received a hyaluronan-based scaffold and the contralateral defect received the corresponding polyester-based scaffold. Rabbits were euthanized 4, 12 and 20 weeks after surgery and the condyles dissected and processed for histology. Only ACP-treated defects presented bone at the base of the defect at 4 weeks. At 12 weeks, only defects treated with rapidly dissolving implants (ACP and PLGA) presented bone reconstitution consistently, while bone was present in only one third of those treated with slowly dissolving scaffolds (HYAFF-11 and PLLA). After 20 weeks, the articular surface of PLGA-treated defects presented fibrillation more frequently than in ACP-treated defects. The surface of defects treated with slowly dissolving scaffolds presented more cracks and fissures. The degradation rate of the scaffolds is critical for the repair process. Slowly dissolving scaffolds sustain thicker cartilage at the surface but, it frequently presents cracks and discontinuities. These scaffolds also delay bone formation at the base of the defects. Hyaluronan-based scaffolds appear to allow faster cell infiltration leading to faster tissue formation. The degradation of ACP leads to rapid bone formation while the slow degradation of HYAFF-11 prolongs the presence of cartilage and delays endochondral bone formation.

  7. Role of the disaggregase ClpB in processing of proteins aggregated as inclusion bodies.

    PubMed

    Zblewska, Kamila; Krajewska, Joanna; Zolkiewski, Michal; Kędzierska-Mieszkowska, Sabina

    2014-08-01

    Overproduction of heterologous proteins in bacterial systems often results in the formation of insoluble inclusion bodies (IBs), which is a major impediment in biochemical research and biotechnology. In principle, the activity of molecular chaperones could be employed to gain control over the IB formation and to improve the recombinant protein yields, but the potential of each of the major bacterial chaperones (DnaK/J, GroEL/ES, and ClpB) to process IBs has not been fully established yet. We investigated the formation of inclusion bodies (IBs) of two aggregation-prone proteins, VP1LAC and VP1GFP, overproduced in Escherichiacoli in the presence and absence of the chaperone ClpB. We found that both ClpB isoforms, ClpB95 and ClpB80 accumulated in E. coli cells during the production of IBs. The amount of IB proteins increased in the absence of ClpB. ClpB supported the resolubilization and reactivation of the aggregated VP1LAC and VP1GFP in E. coli cells. The IB disaggregation was optimal in the presence of both ClpB95 and ClpB80. Our results indicate an essential role of ClpB in controlling protein aggregation and inclusion body formation in bacteria. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. ANTIBACTERIAL EFFICACY OF INTRACANAL MEDICAMENTS ON BACTERIAL BIOFILM: A CRITICAL REVIEW

    PubMed Central

    Estrela, Carlos; Sydney, Gilson Blitzkow; Figueiredo, José Antonio Poli; Estrela, Cyntia Rodrigues de Araújo

    2009-01-01

    The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8% referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm. PMID:19148398

  9. Proteolytic digestion of bacterial inclusion body proteins during dynamic transition between soluble and insoluble forms.

    PubMed

    Carrió, M M; Corchero, J L; Villaverde, A

    1999-09-14

    Inclusion bodies formed by two closely related hybrid proteins, namely VP1LAC and LACVP1, have been compared during their building in Escherichia coli. Features of these proteins are determinant of aggregation rates and protein composition of the bodies, generating insoluble particles with distinguishable volume evolution. Interestingly, in LACVP1 and less perceptibly in VP1LAC bodies, an important fraction of the aggregated polypeptide is lost at a given stage of body construction. Stable degradation intermediates of the more fragile LACVP1 are concomitantly found embedded in the bodies. When recombinant protein synthesis is arrested in growing cells, the amount of aggregated protein drops while the amount of soluble protein undergoes a sudden rise before proteolysis. This indicates an architectural plasticity during the in vivo building of the studied inclusion bodies by a dynamic transition between soluble and insoluble forms of the recombinant proteins involved. During this transition, protease-sensitive polypeptides can suffer an efficient proteolytic attack and the resulting fragments further aggregate as inclusion body components.

  10. The storage stability of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags

    NASA Astrophysics Data System (ADS)

    Ahn, Jeong-Hyeon; Deep, Akash; Kim, Ki-Hyun

    2016-09-01

    In this study, the sorptive loss properties of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags were investigated as a function of storage duration. To this end, the relative recovery of gas phase standards of BVOCs, obtained via vaporization of liquid phase standards, was computed by calibrating their standards (response factors: RF) represnting each phase. Accordingly, the results indicated either slight loss (-5.59% (isoprene), -2.39% (camphene), -1.69% ((R)-(+)-limonene), -0.88% (p-cymene)) or gain (1.47% (γ-terpinene), 2.27% (α-terpinene), 2.63% (α-phellandrene), 2.73% ((+)-3-carene), 3.93% ((+)-β-pinene), and 5.98% ((+)-α-pinene)). Through comparison of the calibration results across storage time, the temporal stability of BVOCs was assessed. Longer BVOC storage time in polyester aluminum (PEA) bags lowered the relative recovery of BVOCs. The relative loss of BVOCs, if calculated in terms of mean bag standard RF ratios (relative to liquid standard) across elapsed time, decreased systematically: 0.99 ± 0.05 (0 h), 0.88 ± 0.06 (24 h), 0.66 ± 0.11 (72 h), and 0.62 ± 0.14 (120 h). It is thus recommended to complete the analysis of BVOC in PEA bags within 24 h of sample acquisition. As such, it is important to apply appropriate sampling approaches with a proper storage plan when measuring ambient BVOCs collected by bag sampling methods.

  11. Co-Expression of ORFCma with PHB Depolymerase (PhaZCma ) in Escherichia coli Induces Efficient Whole-Cell Biodegradation of Polyesters.

    PubMed

    Lee, Ming-Chieh; Liu, En-Jung; Yang, Cheng-Han; Hsiao, Li-Jung; Wu, Tzong-Ming; Li, Si-Yu

    2018-04-01

    Whole-cell degradation of polyesters not only avoids the tedious process of enzyme separation, but also allows the degraded product to be reused as a carbon source. In this study, Escherichia coli BL21(DE3) harboring phaZ Cma , a gene encoding poly(3-hydroxybutyrate) (PHB) depolymerase from Caldimonas manganoxidans, is constructed. The extra-cellular fraction of E. coli/pPHAZ exhibits a fast PHB degradation rate where it only took 35 h to completely degrade PHB films, while C. manganoxidans takes 81 h to do the same. The co-expression of ORF Cma (a putative periplasmic substrate binding protein that is within the same operon of phaZ Cma ) further improves the PHB degradation. While 28 h is needed for E. coli/pPHAZ to cause an 80% weight loss in PHB films, E. coli/pORFPHAZ needs only 21 h. Furthermore, it is able to degrade at-least four different polyesters, PHB, poly(lactic acid) (PLA), polycaprolactone (PCL), and poly(butylene succinate-co-adipate) (PBSA). Testing of the time course of 3-hydroxybutyrate concentration and the turbidity of the degradation solutions over time shows that PhaZ Cma has both exo- and endo-enzymatic activity. The whole-cell E. coli/pORFPHAZ can be used for recycling various polyesters while ORF Cma can potentially be a universal element for enhancing the secretion of recombinant protein. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Characterization of polyesters by matrix-assisted laser desorption/ionization and Fourier transform mass spectrometry.

    PubMed

    Mize, Todd H; Simonsick, William J; Amster, I Jonathan

    2003-01-01

    Two homopolyesters, poly(neopentyl glycol-alt-isophthalic acid) and poly(hexanediol-alt-azelaic acid), and two copolyesters, poly(dipropoxylated bisphenol-A-alt-(isophthalic acid-co-adipic acid)) and poly(neopentyl glycol-alt-(adipic acid-co-isophthalic acid)) were analyzed by internal source matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS). The high resolution and high mass accuracy provided by FTMS greatly facilitate the characterization of the polyester and copolyester samples. Isobaric resolution allows the ion abundances of overlapping isotopic envelopes to be assessed. Repeat units were confirmed and end functionality assigned. Single shot mass spectra of the entire polymeric distribution demonstrate that the dynamic range of this internal MALDI source instrument and the analyzer cell exceeds performance of those previously reported for higher field instruments. Corrections of space charge mass shift effects are demonstrated for the analytes using an external calibrant and (subsequent to confirmation of structure) via internal calibration which removes ambiguity due to space charge differences in calibrant and analyte spectra. Capillary gel permeation chromatography was used to prepare low polydispersity samples from a high polydispersity polyester, improving the measurement of molecular weight distribution two-fold while retaining the benefits of high resolution mass spectrometry for elucidation of oligomer identity.

  13. Study of the effect of surface treatment of kenaf fibre on mechanical properties of kenaf filled unsaturated polyester composite

    NASA Astrophysics Data System (ADS)

    Salem, I. A. S.; Rozyanty, A. R.; Betar, B. O.; Adam, T.; Mohammed, M.; Mohammed, A. M.

    2017-10-01

    In this research, unsaturated polyester/kenaf fiber (UP/KF) composites was prepared by using hand lay-up process. The effect of surface treatment of kenaf fiber on mechanical properties of kenaf filled unsaturated polyester composites were studied. Different concentrationsof stearic acid (SA) were applied, i.e. 0, 0.4, and 0.8 wt%. Tensile strength of untreated UP/KF composites was found to be higher for 40 wt% loading of kenaf fiber. The highest tensile strength value was obtained after treatment with 0.4 wt% concentration of stearic acid at 56 MPa and tensile modulus was at 2409 MPa. From the flexural strength result obtained, it is clearly seen that 40 wt% loading of kenaf fiber and treatment with 0.4 wt% concentration of stearic acid give the highest value at 72 MPa and flexural modulus at 3929 MPa.

  14. THE PHASE BEHAVIOR OF FLUORINATED DIOLS, DIVINYL ADIPATE, AND A FLUORINATED POLYESTER IN SUPERCRITICAL CARBON DIOXIDE. (R828131)

    EPA Science Inventory

    The use of supercritical carbon dioxide as a reaction medium for polyester synthesis is hindered by the low solubility of diols in CO2. However, it has been previously demonstrated that fluorinated compounds can exhibit greater miscibility with carbon dioxide than t...

  15. Fighting cancer with nanomedicine---drug-polyester nanoconjugates for targeted cancer therapy

    NASA Astrophysics Data System (ADS)

    Yin, Qian

    The aim of my Ph. D. research is to develop drug-polyester nanoconjugates (NCs) as a novel translational polymeric drug delivery system that can successfully evade non-specific uptake by reticuloendothelial system (RES) and facilitate targeted cancer diagnosis and therapy. By uniquely integrating well-established chemical reaction-controlled ring opening polymerization (ROP) with nanoprecipitation technique, I successfully developed a polymeric NC system based on poly(lactic acid) and poly(O-carboxyanhydrides) (OCA) that allows for the quantitative loading and controlled release of a variety of anticancer drugs. The developed NC system could be easily modified with parmidronate, one of bisphosphonates commonly used as the treatment for disease characterized by osteolysis, to selectively deliver doxorubicin (Doxo) to the bone tissues and substantially to improve their therapeutic efficiency in inhibiting the growth of osteosarcoma in both murine and canine models. More importantly, the developed NCs could avidly bind to human serum albumin, a ubiquitous protein in the blood, to bypass the endothelium barrier and penetrate into tumor tissues more deeply and efficiently. When compared with PEGylated NCs, these albumin-bound NCs showed significantly reduced accumulation in RES and enhanced tumor accumulation, which consequently contributed to higher their tumor inhibition capabilities. In addition, the developed NC system allows easy incorporation of X-ray computed tomography (CT) contrast agents to largely facilitate personalized therapy by improving diagnosis accuracy and monitoring therapeutic efficacy. Through the synthetic and formulation strategy I developed, a large quantity (grams or larger-scale) of drug-polyester NCs can be easily obtained, which can be used as a model drug delivery system for fundamental studies as well as a real drug delivery system for disease treatment in clinical settings.

  16. Biodegradation of Polyester Polyurethane by Endophytic Fungi▿

    PubMed Central

    Russell, Jonathan R.; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G.; Dantzler, Kathleen W.; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M.; Koppstein, David; Marks, Daniel H.; Mittermiller, Paul A.; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A.; Vishnevetsky, Michael; Williams, Neely E.; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A.

    2011-01-01

    Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation. PMID:21764951

  17. Biodegradation of polyester polyurethane by endophytic fungi.

    PubMed

    Russell, Jonathan R; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G; Dantzler, Kathleen W; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M; Koppstein, David; Marks, Daniel H; Mittermiller, Paul A; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A; Vishnevetsky, Michael; Williams, Neely E; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A

    2011-09-01

    Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation.

  18. Mulching effects of plant fiber and plant fiber-polyester mats combined with fertilizer on loblslly pine seedlings

    Treesearch

    James D. Haywood; John A. Youngquist

    1991-01-01

    In this preliminary study, several mattings, combined with and without fertilizer application, were tested around newly planted loblolly, pine (Pinus taeda L.) seedlings. After 9 months in the field, jute- polyester and jute mats had similar survival rates relitive to controls, but hemlock-po1yvester mats had depressed survival when used in...

  19. Chemical Resistance of Ornamental Compound Stone Produced with Marble Waste and Unsaturated Polyester

    NASA Astrophysics Data System (ADS)

    Ribeiro, Carlos E. Gomes; Rodriguez, Rubén J. Sánchez; Vieira, Carlos M. Fontes

    Ornamental compound stone are produced by industry for decades, however, few published studies describe these materials. Brazil has many deposits of stone wastes and a big potential to produce these materials. This work aims to evaluate the chemical resistance of ornamental compound stones produced with marble waste and unsaturated polyester. An adaptation of Annex H of ABNT NBR 13818:97 standard, with reagents commonly used in household products, was used. The results were compared with those obtained for natural stone used in composite production.

  20. Effects of Porous Polystyrene Resin Parameters on Candida antarctica Lipase B Adsorption, Distribution, and Polyester Synthesis Activity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen,B.; Miller, M.; Gross, R.

    2007-01-01

    Polystyrene resins with varied particle sizes (35 to 350-600 {mu}m) and pore diameters (300-1000 {angstrom}) were employed to study the effects of immobilization resin particle size and pore diameter on Candida antarctica Lipase B (CALB) loading, distribution within resins, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed rapidly (saturation time {<=}4 min) for particle sizes 120 {mu}m (pore size = 300 {angstrom}). Infrared microspectroscopy showed that CALB forms protein loading fronts regardless of resin particle size at similar enzyme loadings ({approx}8%). From the IR images, the fractions of total surface area available to the enzyme aremore » 21, 33, 35, 37, and 88% for particle sizes 350-600, 120, 75, 35 {mu}m (pore size 300 {angstrom}), and 35 {mu}m (pore size 1000 {angstrom}), respectively. Titration with methyl p-nitrophenyl n-hexylphosphate (MNPHP) showed that the fraction of active CALB molecules adsorbed onto resins was {approx}60%. The fraction of active CALB molecules was invariable as a function of resin particle and pore size. At {approx}8% (w/w) CALB loading, by increasing the immobilization support pore diameter from 300 to 1000 {angstrom}, the turnover frequency (TOF) of {var_epsilon}-caprolactone ({var_epsilon}-CL) to polyester increased from 12.4 to 28.2 s{sup -1}. However, the {var_epsilon}-CL conversion rate was not influenced by changes in resin particle size. Similar trends were observed for condensation polymerizations between 1,8-octanediol and adipic acid. The results herein are compared to those obtained with a similar series of methyl methacrylate resins, where variations in particle size largely affected CALB distribution within resins and catalyst activity for polyester synthesis.« less

  1. Double fixation of displaced patella fractures using bioabsorbable cannulated lag screws and braided polyester suture tension bands.

    PubMed

    Qi, Li; Chang, Cao; Xin, Tang; Xing, Pei Fu; Tianfu, Yang; Gang, Zhong; Jian, Li

    2011-10-01

    To evaluate the effectiveness and safety of a new double fixation technique for displaced patellar fractures using bioabsorbable cannulated lag screws and braided polyester suture tension bands. Fifteen patients (mean age of 46.2 years) with displaced transverse or comminuted patella fractures were enrolled in this prospective study. All of the patients were treated via the open reduction internal fixation (ORIF) procedure using bioabsorbable cannulated lag screws and braided polyester suture tension bands. The patients were followed post-surgery to evaluate (1) the time required for radiographic bone union, (2) the knee joint range of motion at the time of radiographic bone union, (3) the degree of pain assessed using the visual analogue scale (VAS), (4) the function of the knee using the Lysholm score and (5) the presence of any additional complications from the surgery. All of the patients were followed post-treatment for more than 1 year (range, 12-19 months; mean post-treatment follow up time, 14 months). The bone union of the fractures as seen radiographically occurred approximately 3 months from surgery in all cases without implant failure or redisplacement of the fractured site. The mean knee joint range of motion was from 0 to 134.6°, and the mean VAS score was 0.7 at the time of bone union. The mean Lysholm scores at the time of bone union and 12 months post-surgery were 86.7 and 95.7, respectively. No postoperative complications, such as infection, dislocation or breakage of the implants, were observed. Moreover, all of the patients returned to their previous activity level. This new double fixation technique using bioabsorbable cannulated lag screws and braided polyester suture tension bands resulted in satisfactory outcomes for patella fractures without any obvious complications. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Nondestructive identification of dye mixtures in polyester and cotton fibers using raman spectroscopy and ultraviolet-visible (UV-Vis) microspectrophotometry.

    PubMed

    Was-Gubala, Jolanta; Starczak, Roza

    2015-01-01

    Presented in this paper is an assessment of the applicability of Raman spectroscopy and microspectrophotometry (MSP) in visible and ultraviolet light (UV-Vis) in the examination of textile fibers dyed with mixtures of synthetic dyes. Fragments of single polyester fibers, stained with ternary mixtures of disperse dyes in small mass concentrations, and fragments of single cotton fibers, dyed with binary or ternary mixtures of reactive dyes, were subjected to the study. Three types of excitation sources, 514, 633, and 785 nm, were used during Raman examinations, while the MSP study was conducted in the 200 to 800 nm range. The results indicate that the capabilities for discernment of dye mixtures are similar in the spectroscopic methods that were employed. Both methods have a limited capacity to distinguish slightly dyed polyester fiber; additionally, it was found that Raman spectroscopy enables identification of primarily the major components in dye mixtures. The best results, in terms of the quality of Raman spectra, were obtained using an excitation source from the near infrared. MSP studies led to the conclusion that polyester testing should be carried out in the range above 310 nm, while for cotton fibers there is no limitation or restriction of the applied range. Also, MSP UV-Vis showed limited possibilities for discriminatory analysis of cotton fibers dyed with a mixture of reactive dyes, where the ratio of the concentration of the main dye used in the dyeing process to minor dye was higher than four. The results presented have practical applications in forensic studies, inter alia.

  3. Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation.

    PubMed

    Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John

    2015-02-06

    Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES-TiO2 and PE-TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti(4+)/Ti(3+) redox catalysis occurring on PES-TiO2 and PE-TiO2 during the bacterial inactivation process. On PE-TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C-H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES-TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1-5% wt PES-TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces.

  4. Developing photoreceptor-based models of visual attraction in riverine tsetse, for use in the engineering of more-attractive polyester fabrics for control devices.

    PubMed

    Santer, Roger D

    2017-03-01

    Riverine tsetse transmit the parasites that cause the most prevalent form of human African trypanosomiasis, Gambian HAT. In response to the imperative for cheap and efficient tsetse control, insecticide-treated 'tiny targets' have been developed through refinement of tsetse attractants based on blue fabric panels. However, modern blue polyesters used for this purpose attract many less tsetse than traditional phthalogen blue cottons. Therefore, colour engineering polyesters for improved attractiveness has great potential for tiny target development. Because flies have markedly different photoreceptor spectral sensitivities from humans, and the responses of these photoreceptors provide the inputs to their visually guided behaviours, it is essential that polyester colour engineering be guided by fly photoreceptor-based explanations of tsetse attraction. To this end, tsetse attraction to differently coloured fabrics was recently modelled using the calculated excitations elicited in a generic set of fly photoreceptors as predictors. However, electrophysiological data from tsetse indicate the potential for modified spectral sensitivities versus the generic pattern, and processing of fly photoreceptor responses within segregated achromatic and chromatic channels has long been hypothesised. Thus, I constructed photoreceptor-based models explaining the attraction of G. f. fuscipes to differently coloured tiny targets recorded in a previously published investigation, under differing assumptions about tsetse spectral sensitivities and organisation of visual processing. Models separating photoreceptor responses into achromatic and chromatic channels explained attraction better than earlier models combining weighted photoreceptor responses in a single mechanism, regardless of the spectral sensitivities assumed. However, common principles for fabric colour engineering were evident across the complete set of models examined, and were consistent with earlier work. Tools for the

  5. Developing photoreceptor-based models of visual attraction in riverine tsetse, for use in the engineering of more-attractive polyester fabrics for control devices

    PubMed Central

    2017-01-01

    Riverine tsetse transmit the parasites that cause the most prevalent form of human African trypanosomiasis, Gambian HAT. In response to the imperative for cheap and efficient tsetse control, insecticide-treated ‘tiny targets’ have been developed through refinement of tsetse attractants based on blue fabric panels. However, modern blue polyesters used for this purpose attract many less tsetse than traditional phthalogen blue cottons. Therefore, colour engineering polyesters for improved attractiveness has great potential for tiny target development. Because flies have markedly different photoreceptor spectral sensitivities from humans, and the responses of these photoreceptors provide the inputs to their visually guided behaviours, it is essential that polyester colour engineering be guided by fly photoreceptor-based explanations of tsetse attraction. To this end, tsetse attraction to differently coloured fabrics was recently modelled using the calculated excitations elicited in a generic set of fly photoreceptors as predictors. However, electrophysiological data from tsetse indicate the potential for modified spectral sensitivities versus the generic pattern, and processing of fly photoreceptor responses within segregated achromatic and chromatic channels has long been hypothesised. Thus, I constructed photoreceptor-based models explaining the attraction of G. f. fuscipes to differently coloured tiny targets recorded in a previously published investigation, under differing assumptions about tsetse spectral sensitivities and organisation of visual processing. Models separating photoreceptor responses into achromatic and chromatic channels explained attraction better than earlier models combining weighted photoreceptor responses in a single mechanism, regardless of the spectral sensitivities assumed. However, common principles for fabric colour engineering were evident across the complete set of models examined, and were consistent with earlier work. Tools for

  6. Development of a restricted state space stochastic differential equation model for bacterial growth in rich media.

    PubMed

    Møller, Jan Kloppenborg; Bergmann, Kirsten Riber; Christiansen, Lasse Engbo; Madsen, Henrik

    2012-07-21

    In the present study, bacterial growth in a rich media is analysed in a Stochastic Differential Equation (SDE) framework. It is demonstrated that the SDE formulation and smoothened state estimates provide a systematic framework for data driven model improvements, using random walk hidden states. Bacterial growth is limited by the available substrate and the inclusion of diffusion must obey this natural restriction. By inclusion of a modified logistic diffusion term it is possible to introduce a diffusion term flexible enough to capture both the growth phase and the stationary phase, while concentration is restricted to the natural state space (substrate and bacteria non-negative). The case considered is the growth of Salmonella and Enterococcus in a rich media. It is found that a hidden state is necessary to capture the lag phase of growth, and that a flexible logistic diffusion term is needed to capture the random behaviour of the growth model. Further, it is concluded that the Monod effect is not needed to capture the dynamics of bacterial growth in the data presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Characterization of a resorbable poly(ester urethane) with biodegradable hard segments.

    PubMed

    Dempsey, David K; Robinson, Jennifer L; Iyer, Ananth V; Parakka, James P; Bezwada, Rao S; Cosgriff-Hernandez, Elizabeth M

    2014-01-01

    The rapid growth of regenerative medicine and drug delivery fields has generated a strong need for improved polymeric materials that degrade at a controlled rate into safe, non-cytotoxic by-products. Polyurethane thermoplastic elastomers offer several advantages over other polymeric materials including tunable mechanical properties, excellent fatigue strength, and versatile processing. The variable segmental chemistry in developing resorbable polyurethanes also enables fine control over the degradation profile as well as the mechanical properties. Linear aliphatic isocyanates are most commonly used in biodegradable polyurethane formulations; however, these aliphatic polyurethanes do not match the mechanical properties of their aromatic counterparts. In this study, a novel poly(ester urethane) (PEsU) synthesized with biodegradable aromatic isocyanates based on glycolic acid was characterized for potential use as a new resorbable material in medical devices. Infrared spectral analysis confirmed the aromatic and phase-separated nature of the PEsU. Uniaxial tensile testing displayed stress-strain behavior typical of a semi-crystalline polymer above its Tg, in agreement with calorimetric findings. PEsU outperformed aliphatic PCL-based polyurethanes likely due to the enhanced cohesion of the aromatic hard domains. Accelerated degradation of the PEsU using 0.1 M sodium hydroxide resulted in hydrolysis of the polyester soft segment on the surface, reduced molecular weight, surface cracking, and a 30% mass loss after four weeks. Calorimetric studies indicated a disruption of the soft segment crystallinity after incubation which corresponded with a drop in initial modulus of the PEsU. Finally, cytocompatibility testing with 3T3 mouse fibroblasts exhibited cell viability on PEsU films comparable to a commercial poly(ether urethane urea) after 24 h followed by 85% cell viability at 72 h. Overall, this new resorbable polyurethane shows strong potential for use in wide

  8. Bacterial vaginosis in pregnancy and the risk of prematurity: a meta-analysis.

    PubMed

    Flynn, C A; Helwig, A L; Meurer, L N

    1999-11-01

    We conducted this meta-analysis to determine the magnitude of risk conferred by bacterial vaginosis during pregnancy on preterm delivery. We selected articles from a combination of the results of a MEDLINE search (1966-1996), a manual search of bibliographies, and contact with leading researchers. We included case control and cohort studies evaluating the risk of preterm delivery, low birth weight, preterm premature rupture of membranes, or preterm labor for pregnant women who had bacterial vaginosis and those who did not. DATA COLLECTION AND ANALYSIS. Two investigators independently conducted literature searches, applied inclusion criteria, performed data extraction, and critically appraised included studies. Summary estimates of risk were calculated as odds ratios (ORs) using the fixed and random effects models. We included 19 studies in the final analysis. Bacterial vaginosis during pregnancy was associated with a statistically significant increased risk for all outcomes evaluated. In the subanalyses for preterm delivery, bacterial vaginosis remained a significant risk factor. Pooling adjusted ORs yielded a 60% increased risk of preterm delivery given the presence of bacterial vaginosis. Bacterial vaginosis is an important risk factor for prematurity and pregnancy morbidity. Further studies will help clarify the benefits of treating bacterial vaginosis and the potential role of screening during pregnancy.

  9. Cerebrospinal fluid ferritin in children with viral and bacterial meningitis.

    PubMed

    Rezaei, M; Mamishi, S; Mahmoudi, S; Pourakbari, B; Khotaei, G; Daneshjou, K; Hashemi, N

    2013-01-01

    Despite the fact that the prognosis of bacterial meningitis has been improved by the influence of antibiotics, this disease is still one of the significant causes of morbidity and mortality in children. Rapid differentiation between bacterial and aseptic meningitis, and the need for immediate antibiotic treatment in the former, is crucial in the prognosis of these patients. Ferritin is one of the most sensitive biochemical markers investigated in cerebrospinal fluid (CSF) for the early diagnosis of bacterial meningitis. The present study aims to evaluate the diagnostic capability of CSF ferritin in differentiating bacterial and viral meningitis in the paediatric setting. A cross-sectional study was carried out in the referral Children's Medical Center Hospital, Tehran, during 2008 and 2009. According to the inclusion criteria, CSF samples from 42 patients with suspected meningitis were obtained and divided into two meningitis groups, bacterial (n = 18) and viral (n = 24). Ferritin and other routine determinants (i.e., leucocytes, protein and glucose) were compared between the two groups. Ferritin concentration in the bacterial meningitis group was 106.39 +/- 86.96 ng/dL, which was considerably higher than in the viral meningitis group (10.17 +/- 14.09, P < 0.001). Mean CSF protein concentration and cell count were significantly higher in the bacterial meningitis group and showed a positive correlation with CSF ferritin. In conclusion, this study suggests that CSF ferritin concentration is an accurate test for the early differentiation of bacterial and aseptic meningitis; however, further investigation on a larger cohort of patients is required to confirm this finding.

  10. ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS, FILTRATION GROUP, AEROSTAR "C-SERIES" POLYESTER PANEL FILTER

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of the AeroStar "C-Series" Polyester Panel Filter air filter for dust and bioaerosol filtration manufactured by Filtration Group. The pressure drop across the filter was 126 Pa clean and 267...

  11. Overcoming STC2 mediated drug resistance through drug and gene co-delivery by PHB-PDMAEMA cationic polyester in liver cancer cells.

    PubMed

    Cheng, Hongwei; Wu, Zhixian; Wu, Caisheng; Wang, Xiaoyuan; Liow, Sing Shy; Li, Zibiao; Wu, Yun-Long

    2018-02-01

    Stanniocalcin 2 (STC2) overexpression in hepatocellular carcinoma (HCC) could lead to poor prognosis, which might be due to its induced P-glycoprotein and Bcl-2 protein expression level increase. P-glycoprotein or membrane pump induced drug efflux and altered prosurvival Bcl-2 expression are key mechanisms for drug resistance leading to failure of chemotherapy in HCC. However, current strategy to overcome both P-glycoprotein and Bcl-2 protein induced drug resistance was rarely reported. In this work, we utilized an amphiphilic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) cationic polyester to encapsulate chemotherapeutic paclitaxel (PTX) in hydrophobic PHB domain and Bcl-2 convertor Nur77/ΔDBD gene (Nur77 without DNA binding domain for mitochondria localization) by formation of polyplex due to cationic PDMAEMA segment, to effectively inhibit the drug resistant HepG2/STC2 and SMCC7721/STC2 liver cancer cell growth. Thanks to the cationic nanoparticle complex formation ability and high transfection efficiency to express Bcl-2 conversion proteins, PHB-PDMAEMA/PTX@polyplex could partially impair P-glycoprotein induced PTX efflux and activate the apoptotic function of previous prosurvival Bcl-2 protein. This is the pioneer report of cationic amphiphilic polyester PHB-PDMAEMA to codeliver anticancer drug and therapeutic plasmid to overcome both pump and non-pump mediated chemotherapeutic resistance in liver cancer cells, which might be inspiring for the application of polyester in personalized cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Facile synthesis of semi-library of low charge density cationic polyesters from poly(alkylene maleate)s for efficient local gene delivery.

    PubMed

    Yan, Huijie; Zhu, Dingcheng; Zhou, Zhuxian; Liu, Xin; Piao, Ying; Zhang, Zhen; Liu, Xiangrui; Tang, Jianbin; Shen, Youqing

    2018-03-30

    Cationic polymers are one of the main non-viral vectors for gene therapy, but their applications are hindered by the toxicity and inefficient transfection, particularly in the presence of serum or other biological fluids. While rational design based on the current understanding of gene delivery process has produced various cationic polymers with improved overall transfection, high-throughput parallel synthesis of libraries of cationic polymers seems a more effective strategy to screen out efficacious polymers. Herein, we demonstrate a novel platform for parallel synthesis of low cationic charge-density polyesters for efficient gene delivery. Unsaturated polyester poly(alkylene maleate) (PAM) readily underwent Michael-addition reactions with various mercaptamines to produce polyester backbones with pendant amine groups, poly(alkylene maleate mercaptamine)s (PAMAs). Variations of the alkylenes in the backbone and the mercaptamines on the side chain produced PAMAs with tunable hydrophobicity and DNA-condensation ability, the key parameters dominating transfection efficiency of the resulting polymer/DNA complexes (polyplexes). A semi-library of such PAMAs was exampled from 7 alkylenes and 18 mercaptamines, from which a lead PAMA, G-1, synthesized from poly(1,4-phenylene bis(methylene) maleate) and N,N-dimethylcysteamine, showed remarkable transfection efficiency even in the presence of serum, owing to its efficient lysosome-circumventing cellular uptake. Furthermore, G-1 polyplexes efficiently delivered the suicide gene pTRAIL to intraperitoneal tumors and elicited effective anticancer activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. The Plant Polyester Cutin: Biosynthesis, Structure, and Biological Roles.

    PubMed

    Fich, Eric A; Segerson, Nicholas A; Rose, Jocelyn K C

    2016-04-29

    Cutin, a polyester composed mostly of oxygenated fatty acids, serves as the framework of the plant cuticle. The same types of cutin monomers occur across most plant lineages, although some evolutionary trends are evident. Additionally, cutins from some species have monomer profiles that are characteristic of the related polymer suberin. Compositional differences likely have profound structural consequences, but little is known about cutin's molecular organization and architectural heterogeneity. Its biological importance is suggested by the wide variety of associated mutants and gene-silencing lines that show a disruption of cuticular integrity, giving rise to numerous physiological and developmental abnormalities. Mapping and characterization of these mutants, along with suppression of gene paralogs through RNA interference, have revealed much of the biosynthetic pathway and several regulatory factors; however, the mechanisms of cutin polymerization and its interactions with other cuticle and cell wall components are only now beginning to be resolved.

  14. [Spontaneous bacterial peritonitis: impact of microbiological changes].

    PubMed

    Almeida, Paulo Roberto Lerias de; Camargo, Nutianne Schneider; Arenz, Maximilhano; Tovo, Cristiane Valle; Galperim, Bruno; Behar, Paulo

    2007-01-01

    Spontaneous bacterial peritonitis is a serious complication in cirrhotic patients, and the changes in the microbiological characteristics reported in the last years are impacting the choice of antibiotic used in the treatment. To evaluate the change in the epidemiology and antibiotic resistance of the bacteria causing spontaneous bacterial peritonitis in a 7 years period. All the cases of cirrhotic patients with spontaneous bacterial peritonitis with positive cultural examination were retrospectively studied. Two periods were evaluated: 1997-1998 and 2002-2003. The most frequent infecting organisms and the sensitivity in vitro to antibiotics were registered. In the first period (1997-1998) there were 33 cases, 3 (9%) with polymicrobial infection. The most common were: E.coli in 13 (36,11%), Staphylococcus coagulase-negative in 6 (16,66%), K. pneumoniae in 5 (13,88%), S. aureus in 4 (11,11%) and S. faecalis in 3 (8,33%). In 2003-2004, there were 43 cases, 2 (5%) with polymicrobial infection. The most frequent were: Staphylococus coagulase-negative in 16 (35,55%), S. aureus in 8 (17,77%), E. coli in 7 (15,55%) and K. pneumoniae in 3 (6,66%). No one was using antibiotic prophilaxys. The prevalence of S. aureus methicillin-resitant to quinolone and trimethoprim-sulfamethoxazole changed from 25% to 50%, and vancomicin was the only one with absolute activity during all the period. In the same way, the prevalence of E. coli resistant to third generation cephalosporin and to quinolone changed from 0% to 16%. There was a modification of the bacterial population causing spontaneous bacterial peritonitis, with high frequency of gram-positive organisms, as well as an increase in the resistance to the traditionally recommended antibiotics. This study suggests a probable imminent inclusion of a drug against gram-positive organisms in the empiric treatment of spontaneous bacterial peritonitis.

  15. On the suitability of fiberglass reinforced polyester as building material for mesocosms.

    PubMed

    Berghahn, R; Brandsch, J; Piringer, O; Pluta, H J; Winkler, T

    1999-07-01

    Gel- and topcoat surface layers on fiberglass [glass-reinforced plastic (GRP)] made of unsaturated resin based on isophthalic acid polyester and neopentyl glycol (ISO-NPG) were tested for leaching, ecotoxicity of water eluates, and abrasion by river sediments at a current speed of 0.5 m * s-1. Leaching from topcoat tempered at low temperature was significant, whereas it was negligible from highly tempered gelcoat. Water eluates from both gel-and topcoat were nontoxic in routinely employed biotests (bacteria, algae, daphnids). No abrasion by river sediments was detectable. Based on these results, GRP with gelcoat made of ISO-NPG is considered a suitable building material for mesocosms. Copyright 1999 Academic Press.

  16. Septins arrange F-actin-containing fibers on the Chlamydia trachomatis inclusion and are required for normal release of the inclusion by extrusion.

    PubMed

    Volceanov, Larisa; Herbst, Katharina; Biniossek, Martin; Schilling, Oliver; Haller, Dirk; Nölke, Thilo; Subbarayal, Prema; Rudel, Thomas; Zieger, Barbara; Häcker, Georg

    2014-10-07

    Chlamydia trachomatis is an obligate intracellular human pathogen that grows inside a membranous, cytosolic vacuole termed an inclusion. Septins are a group of 13 GTP-binding proteins that assemble into oligomeric complexes and that can form higher-order filaments. We report here that the septins SEPT2, -9, -11, and probably -7 form fibrillar structures around the chlamydial inclusion. Colocalization studies suggest that these septins combine with F actin into fibers that encase the inclusion. Targeting the expression of individual septins by RNA interference (RNAi) prevented the formation of septin fibers as well as the recruitment of actin to the inclusion. At the end of the developmental cycle of C. trachomatis, newly formed, infectious elementary bodies are released, and this release occurs at least in part through the organized extrusion of intact inclusions. RNAi against SEPT9 or against the combination of SEPT2/7/9 substantially reduced the number of extrusions from a culture of infected HeLa cells. The data suggest that a higher-order structure of four septins is involved in the recruitment or stabilization of the actin coat around the chlamydial inclusion and that this actin recruitment by septins is instrumental for the coordinated egress of C. trachomatis from human cells. The organization of F actin around parasite-containing vacuoles may be a broader response mechanism of mammalian cells to the infection by intracellular, vacuole-dwelling pathogens. Importance: Chlamydia trachomatis is a frequent bacterial pathogen throughout the world, causing mostly eye and genital infections. C. trachomatis can develop only inside host cells; it multiplies inside a membranous vacuole in the cytosol, termed an inclusion. The inclusion is covered by cytoskeletal "coats" or "cages," whose organization and function are poorly understood. We here report that a relatively little-characterized group of proteins, septins, is required to organize actin fibers on the

  17. Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

    USDA-ARS?s Scientific Manuscript database

    The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

  18. Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation

    PubMed Central

    Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John

    2015-01-01

    Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES–TiO2 and PE–TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti4+/Ti3+ redox catalysis occurring on PES–TiO2 and PE–TiO2 during the bacterial inactivation process. On PE–TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C–H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES–TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1–5% wt PES–TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces. PMID:25657831

  19. Polyester polymer alloy as a high-performance membrane.

    PubMed

    Igoshi, Tadaaki; Tomisawa, Narumi; Hori, Yoshinori; Jinbo, Yoichi

    2011-01-01

    Polyester polymer alloy (PEPA) membrane is developed as a synthetic polymermembrane. It consists of two polymers - polyethersulfone (PES) and polyarylate (PAR).The pore size in membrane can be controlled by a blend ratio of PES and PAR. One unique characteristic is that PEPA membrane has three layers of a skin layer on the inner surface, a porous layer in the membrane, and a skin layer on the outer surface, respectively. The permeability of water and substances is controlled by the skin layer on the inner surface. PEPA membrane dialyzer can be adequately considered as a high-performance dialyzer. Furthermore, the skin layer on the outer surface can block endotoxin from the dialysis fluid side. PEPA membrane can therefore be used as an endotoxin-retentive filter. The other unique characteristic is that each amount of albumin loss or β2-microglobulin removal can be controlled by an additive amount of polyvinylpyrrolidone. This means that the PEPA dialyzer can be clinically used to meet the conditions of the patient. Copyright © 2011 S. Karger AG, Basel.

  20. The Assessing of the Failure Behavior of Glass/Polyester Composites Subject to Quasi Static Stresses

    NASA Astrophysics Data System (ADS)

    Stanciu, M. D.; Savin, A.; Teodorescu-Drăghicescu, H.

    2017-06-01

    Using glass fabric reinforced composites for structure of wind turbine blades requires high mechanical strengths especially to cyclic stresses. Studies have shown that approximately 50% of composite material failure occurs because of fatigue. Composites behavior to cyclic stresses involves three stages regarding to stiffness variation: the first stage is characterized by the accelerated decline of stiffness with micro-cracks, the second stage - a slight decrease of stiffness characterized by the occurrence of delamination and third stage characterized by higher decreases of resistance and occurrence of fracture thereof. The aim of the paper is to analyzed the behavior of composites reinforced with glass fibers fabric type RT500 and polyester resin subjected to tensile cyclic loading with pulsating quasi-static regime with asymmetry coefficient R = 0. The samples were tested with the universal tensile machine LS100 Lloyd Instruments Plus, with a load capacity of 100 kN. The load was applied with different speeds of 1 mm/min, 10 mm/min and 20 mm/min. After tests, it was observed that the greatest permanent strains were recorded in the first load cycles when the total energy storage by material was lost due to internal friction. With increasing number of cycles, the glass/polyester composites ability to store energy of deformation decreases, the flow phenomenon characterized by large displacements to smaller loading forces appearing.

  1. Effect of liquid immersion of PEDOT: PSS-coated polyester fabric on surface resistance and wettability

    NASA Astrophysics Data System (ADS)

    Getnet Tadesse, Melkie; Loghin, Carmen; Chen, Yan; Wang, Lichuan; Catalin, Dumitras; Nierstrasz, Vincent

    2017-06-01

    Coating of textile fabrics with poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT:PSS) is one of the methods used for obtaining functional or smart applications. In this work, we prepared PEDOT:PSS polymer with certain additives such as polyethylene glycol, methanol (MeOH), and ethylene glycol on polyester fabric substrates by a simple immersion process. Surface resistance was measured and analyzed with analysis of variance to determine the coating parameters at 95% confidence level. Fourier transform infrared (FTIR) analysis and scanning electron microscopy (SEM) study of the samples were performed. Contact angle and washing fastness measurements were conducted, to observe the wettability and washing fastness of the samples, respectively. Surface resistance values were decreased by a factor of 100, due to conductive enhancers. As the immersion time and temperature condition varies, surface resistance showed no difference, statistically. FTIR analysis supports the idea that the mechanism responsible for the conductivity enhancement is the partial replacement of PSS from PEDOT chain by forming a hydrogen bond with hydroxyl ion (OH) of the conductive enhancers. A SEM images showed that PEDOT:PSS is well distributed to the surface of the fabrics. Contact angle measurements showed morphology change in the samples. The conductivity was reasonably stable after 10 washing cycles. Altogether, an effective simple immersion of coated polyester fabric is presented to achieve functional textiles that offer a broad range of possible applications.

  2. Etiology of Acute Bacterial Meningitis in Iran: a Systematic Review.

    PubMed

    Ghotaslou, Reza; Yeganeh-Sefidan, Fatemeh; Salahi-Eshlaqi, Behnaz; Ebrahimzadeh-Leylabadlo, Hamed

    2015-08-01

    Acute bacterial meningitis (ABM) is one of the most severe infectious diseases, causing neurologic sequel, and a case fatality rate of 20-30%. The aim of this paper was to summarize the main causes of ABM in Iran. We searched the data for relevant articles using meningitis, etiology, and Iran as search terms. We found 23 papers for inclusion in the review that focused specifically on the ABM, addressing etiology and acute meningitis. Finally, during the 23 years, a total of 18163 cases were recorded, and 1074 cases of which met the criteria for bacterial meningitis. The most common agent associated with bacterial meningitis was S. pneumoniae, followed by H. influenzae, Enterobacter spp., N. meningitidis, and group B streptococcus. The total incidence of ABM during 1991 to 2002 was higher than during 2003-2013. S. pneumoniae still remains a main cause of bacterial meningitis. For improved outcomes, studies are needed to further clarify the etiology of meningitis in Iran, explore simple, accurate, and practical diagnostic tools as PCR, and investigate the most appropriate specific and supportive interventions to manage and prevent meningitis as vaccination.

  3. Study of the indoor decontamination using nanocoated woven polyester fabric

    NASA Astrophysics Data System (ADS)

    Memon, Hafeezullah; Kumari, Naveeta; Jatoi, Abdul Wahab; Khoso, Nazakat Ali

    2017-11-01

    This research primarily deals with the photocatalytic degradation of methanol in indoor air using nanocoated indoor textiles used for curtains as household textiles. The woven polyester was coated by titanium dioxide by sol gel method, using silicon-based binder. The characterization of the coating has been done using scanning electron microscopy (SEM) image analysis, energy dispersive analysis using X-ray (EDAX) and Fourier transform infrared spectroscopy (FTIR). The DIY instrument providing the similar environment as of indoor was designed to assess the performance of the degradation of formaldehyde under UV light. The photocatalytic degradation rate was measured using the absorption value of the solutions obtained in the result of liquid chromatography of test solution and reagent solution. Different amount of dosages (1-3 %) and different time period of coatings (half hour to 3 h) have been evaluated for optimization.

  4. Physicomechanical evaluation of polypropylene, polyester, and polytetrafluoroethylene meshes for inguinal hernia repair.

    PubMed

    Deeken, Corey R; Abdo, Michael S; Frisella, Margaret M; Matthews, Brent D

    2011-01-01

    For meshes to be used effectively for hernia repair, it is imperative that engineers and surgeons standardize the terminology and techniques related to physicomechanical evaluation of these materials. The objectives of this study were to propose standard techniques, perform physicomechanical testing, and classify materials commonly used for inguinal hernia repair. Nine meshes were evaluated: 4 polypropylene, 1 polyester, 1 polytetrafluoroethylene, and 3 partially absorbable. Physical properties were determined through image analysis, laser micrometry, and density measurements. Biomechanical properties were determined through suture retention, tear resistance, uniaxial, and ball burst testing with specimens tested in 2 different orientations. A 1-way ANOVA with Tukey's post-test or a t-test were performed, with p < 0.05. Significant differences were observed due to both mesh type and orientation. Areas of interstices ranged from 0.33 ± 0.01 mm² for ProLite (Atrium Medical Corp) and C-QUR Lite (Atrium Medical Corp) Large to 4.10 ± 0.06 mm² for ULTRAPRO (Ethicon), and filament diameters ranged from 99.00 ±8.1 μm for ProLite Ultra (Atrium Medical Corp) and C-QUR Lite Small to 338.8 ± 3.7 μm for Parietex Flat Sheet TEC (Covidien). These structural characteristics influenced biomechanical properties such as tear resistance and tensile strength. ProLite Ultra, C-QUR Lite Small, ULTRAPRO and INFINIT (WL Gore & Associates) did not resist tearing as effectively as the others. All meshes exhibited supraphysiologic burst strengths except INFINIT and ULTRAPRO. Significant differences exist between the physicomechanical properties of polypropylene, polyester, polytetrafluoroethylene, and partially absorbable mesh prostheses commonly used for inguinal hernia repair. Orientation of the mesh was also shown to be critical for the success of meshes, particularly those demonstrating anisotropy. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All

  5. Using bacterial inclusion bodies to screen for amyloid aggregation inhibitors.

    PubMed

    Villar-Piqué, Anna; Espargaró, Alba; Sabaté, Raimon; de Groot, Natalia S; Ventura, Salvador

    2012-05-03

    The amyloid-β peptide (Aβ42) is the main component of the inter-neuronal amyloid plaques characteristic of Alzheimer's disease (AD). The mechanism by which Aβ42 and other amyloid peptides assemble into insoluble neurotoxic deposits is still not completely understood and multiple factors have been reported to trigger their formation. In particular, the presence of endogenous metal ions has been linked to the pathogenesis of AD and other neurodegenerative disorders. Here we describe a rapid and high-throughput screening method to identify molecules able to modulate amyloid aggregation. The approach exploits the inclusion bodies (IBs) formed by Aβ42 when expressed in bacteria. We have shown previously that these aggregates retain amyloid structural and functional properties. In the present work, we demonstrate that their in vitro refolding is selectively sensitive to the presence of aggregation-promoting metal ions, allowing the detection of inhibitors of metal-promoted amyloid aggregation with potential therapeutic interest. Because IBs can be produced at high levels and easily purified, the method overcomes one of the main limitations in screens to detect amyloid modulators: the use of expensive and usually highly insoluble synthetic peptides.

  6. Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics.

    PubMed

    Teeraphatpornchai, T; Nakajima-Kambe, T; Shigeno-Akutsu, Y; Nakayama, M; Nomura, N; Nakahara, T; Uchiyama, H

    2003-01-01

    Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth.

  7. Bacterial Activity at −2 to −20°C in Arctic Wintertime Sea Ice

    PubMed Central

    Junge, Karen; Eicken, Hajo; Deming, Jody W.

    2004-01-01

    Arctic wintertime sea-ice cores, characterized by a temperature gradient of −2 to −20°C, were investigated to better understand constraints on bacterial abundance, activity, and diversity at subzero temperatures. With the fluorescent stains 4′,6′-diamidino-2-phenylindole 2HCl (DAPI) (for DNA) and 5-cyano-2,3-ditoyl tetrazolium chloride (CTC) (for O2-based respiration), the abundances of total, particle-associated (>3-μm), free-living, and actively respiring bacteria were determined for ice-core samples melted at their in situ temperatures (−2 to −20°C) and at the corresponding salinities of their brine inclusions (38 to 209 ppt). Fluorescence in situ hybridization was applied to determine the proportions of Bacteria, Cytophaga-Flavobacteria-Bacteroides (CFB), and Archaea. Microtome-prepared ice sections also were examined microscopically under in situ conditions to evaluate bacterial abundance (by DAPI staining) and particle associations within the brine-inclusion network of the ice. For both melted and intact ice sections, more than 50% of cells were found to be associated with particles or surfaces (sediment grains, detritus, and ice-crystal boundaries). CTC-active bacteria (0.5 to 4% of the total) and cells detectable by rRNA probes (18 to 86% of the total) were found in all ice samples, including the coldest (−20°C), where virtually all active cells were particle associated. The percentage of active bacteria associated with particles increased with decreasing temperature, as did the percentages of CFB (16 to 82% of Bacteria) and Archaea (0.0 to 3.4% of total cells). These results, combined with correlation analyses between bacterial variables and measures of particulate matter in the ice as well as the increase in CFB at lower temperatures, confirm the importance of particle or surface association to bacterial activity at subzero temperatures. Measuring activity down to −20°C adds to the concept that liquid inclusions in frozen environments

  8. A comparison of tensile properties of polyester composites reinforced with pineapple leaf fiber and pineapple peduncle fiber

    NASA Astrophysics Data System (ADS)

    Juraidi, J. M.; Shuhairul, N.; Syed Azuan, S. A.; Intan Saffinaz Anuar, Noor

    2013-12-01

    Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

  9. Vapor-Liquid Sol-Gel Approach to Fabricating Highly Durable and Robust Superhydrophobic Polydimethylsiloxane@Silica Surface on Polyester Textile for Oil-Water Separation.

    PubMed

    Su, Xiaojing; Li, Hongqiang; Lai, Xuejun; Zhang, Lin; Wang, Jing; Liao, Xiaofeng; Zeng, Xingrong

    2017-08-23

    Large-scale fabrication of superhydrophobic surfaces with excellent durability by simple techniques has been of considerable interest for its urgent practical application in oil-water separation in recent years. Herein, we proposed a facile vapor-liquid sol-gel approach to fabricating highly durable and robust superhydrophobic polydimethylsiloxane@silica surfaces on the cross-structure polyester textiles. Scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated that the silica generated from the hydrolysis-condensation of tetraethyl orthosilicate (TEOS) gradually aggregated at microscale driven by the extreme nonpolar dihydroxyl-terminated polydimethylsiloxane (PDMS(OH)). This led to construction of hierarchical roughness and micronano structures of the superhydrophobic textile surface. The as-fabricated superhydrophobic textile possessed outstanding durability in deionized water, various solvents, strong acid/base solutions, and boiling/ice water. Remarkably, the polyester textile still retained great water repellency and even after ultrasonic treatment for 18 h, 96 laundering cycles, and 600 abrasion cycles, exhibiting excellent mechanical robustness. Importantly, the superhydrophobic polyester textile was further applied for oil-water separation as absorption materials and/or filter pipes, presenting high separation efficiency and great reusability. Our method to construct superhydrophobic textiles is simple but highly efficient; no special equipment, chemicals, or atmosphere is required. Additionally, no fluorinated slianes and organic solvents are involved, which is very beneficial for environment safety and protection. Our findings conceivably stand out as a new tool to fabricate organic-inorganic superhydrophobic surfaces with strong durability and robustness for practical applications in oil spill accidents and industrial sewage emission.

  10. Photocrosslinkable biodegradable elastomers based on cinnamate-functionalized polyesters.

    PubMed

    Zhu, Congcong; Kustra, Stephen R; Bettinger, Christopher J

    2013-07-01

    Synthetic biodegradable elastomers are an emerging class of materials that play a critical role in supporting innovations in bioabsorbable medical implants. This paper describes the synthesis and characterization of poly(glycerol-co-sebacate)-cinnamate (PGS-CinA), a biodegradable elastomer based on hyperbranched polyesters derivatized with pendant cinnamate groups. PGS-CinA can be prepared via photodimerization in the absence of photoinitiators using monomers that are found in common foods. The resulting network exhibits a Young's modulus of 50.5-152.1kPa and a projected in vitro degradation half-life time between 90 and 140days. PGS-CinA elastomers are intrinsically cell-adherent and support rapid proliferation of fibroblasts. Spreading and proliferation of fibroblasts are loosely governed by the substrate stiffness within the range of Young's moduli in PGS-CinA networks that were prepared. The thermo-mechanical properties, biodegradability and intrinsic support of cell attachment and proliferation suggest that PGS-CinA networks are broadly applicable for use in next generation bioabsorable materials including temporary medical devices and scaffolds for soft tissue engineering. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  11. Interactions between F-111 Fuselage Fuel Tank Sealants. Part I. Characterisation of Polyester Sealants and their Hydrolytic Degradation Products,

    DTIC Science & Technology

    1983-12-01

    maleic acid , adipic acid , azelaic acid and suberic acid . To ensure complete esterification during the exhaustive degradation reactions, an...spectroscopic techniques. Major components were shown to be sebacic acid and neopentyl glycol. The most significant difference between the two polyester...and acid equivalent weights of the prepolymers, their hydrolysis products and hydrolysed cured sealants were determined to assess extent of degradation

  12. Chronic bacterial prostatitis and chronic pelvic pain syndrome.

    PubMed

    Bowen, Diana K; Dielubanza, Elodi; Schaeffer, Anthony J

    2015-08-27

    Chronic prostatitis can cause pain and urinary symptoms, and can occur either with an active infection (chronic bacterial prostatitis [CBP]) or with only pain and no evidence of bacterial causation (chronic pelvic pain syndrome [CPPS]). Bacterial prostatitis is characterised by recurrent urinary tract infections or infection in the prostate with the same bacterial strain, which often results from urinary tract instrumentation. However, the cause and natural history of CPPS are unknown and not associated with active infection. We conducted a systematic overview and aimed to answer the following clinical questions: What are the effects of treatments for chronic bacterial prostatitis? What are the effects of treatments for chronic pelvic pain syndrome? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). At this update, searching of electronic databases retrieved 131 studies. After deduplication and removal of conference abstracts, 67 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 51 studies and the further review of 16 full publications. Of the 16 full articles evaluated, three systematic reviews and one RCT were included at this update. We performed a GRADE evaluation for 14 PICO combinations. In this systematic overview, we categorised the efficacy for 12 interventions based on information relating to the effectiveness and safety of 5 alpha-reductase inhibitors, allopurinol, alpha-blockers, local injections of antimicrobial drugs, mepartricin, non-steroidal anti-inflammatory drugs (NSAIDs), oral antimicrobial drugs, pentosan polysulfate, quercetin, sitz baths, transurethral microwave thermotherapy (TUMT), and transurethral resection of the prostate (TURP).

  13. Zonal wavefront sensing using a grating array printed on a polyester film

    NASA Astrophysics Data System (ADS)

    Pathak, Biswajit; Kumar, Suraj; Boruah, Bosanta R.

    2015-12-01

    In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing frame rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.

  14. Zonal wavefront sensing using a grating array printed on a polyester film

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pathak, Biswajit; Boruah, Bosanta R., E-mail: brboruah@iitg.ernet.in; Kumar, Suraj

    2015-12-15

    In this paper, we describe the development of a zonal wavefront sensor that comprises an array of binary diffraction gratings realized on a transparent sheet (i.e., polyester film) followed by a focusing lens and a camera. The sensor works in a manner similar to that of a Shack-Hartmann wavefront sensor. The fabrication of the array of gratings is immune to certain issues associated with the fabrication of the lenslet array which is commonly used in zonal wavefront sensing. Besides the sensing method offers several important advantages such as flexible dynamic range, easy configurability, and option to enhance the sensing framemore » rate. Here, we have demonstrated the working of the proposed sensor using a proof-of-principle experimental arrangement.« less

  15. TDP-43 Inclusion Bodies Formed in Bacteria Are Structurally Amorphous, Non-Amyloid and Inherently Toxic to Neuroblastoma Cells

    PubMed Central

    Capitini, Claudia; Conti, Simona; Perni, Michele; Guidi, Francesca; Cascella, Roberta; De Poli, Angela; Penco, Amanda; Relini, Annalisa; Cecchi, Cristina; Chiti, Fabrizio

    2014-01-01

    Accumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs) and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein. PMID:24497973

  16. Recent Advances in 3D Printing of Aliphatic Polyesters

    PubMed Central

    Frone, Adriana Nicoleta; Brandabur, Călin

    2017-01-01

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

  17. Recent Advances in 3D Printing of Aliphatic Polyesters.

    PubMed

    Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

    2017-12-24

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

  18. MnO2 nanotubes assembled on conductive graphene/polyester composite fabric as a three-dimensional porous textile electrode for flexible electrochemical capacitors.

    PubMed

    Jin, Chun; Jin, Li-Na; Guo, Mei-Xia; Liu, Ping; Zhang, Jia-Nan; Bian, Shao-Wei

    2017-12-15

    A three-dimensional (3D) electrode material was successfully synthesized through a facile ZnO-assisted hydrothermal process in which vertical MnO 2 nanotube arrays were in situ grown on the conductive graphene/polyester composite fabric. The morphology and structure of MnO 2 nanotubes/graphene/polyester textile electrode were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The 3D electrode structure facilitates to achieve the maximum number of active sites for the pesudocapacitance redox reaction, fast electrolyte ion transportation and short ion diffusion path. The electrochemical measurements showed that the electrode possesses good capacitance capacity which reached 498F/g at a scan rate of 2mV/s in Na 2 SO 4 electrolyte solution. The electrode also showed stable electrochemical performances under the conditions of long-term cycling, and mechanical bending and twisting. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Dynamic-mechanical and thermomechanical properties of cellulose nanofiber/polyester resin composites.

    PubMed

    Lavoratti, Alessandra; Scienza, Lisete Cristine; Zattera, Ademir José

    2016-01-20

    Composites of unsaturated polyester resin (UPR) and cellulose nanofibers (CNFs) obtained from dry cellulose waste of softwood (Pinus sp.) and hardwood (Eucalyptus sp.) were developed. The fiber properties and the influence of the CNFs in the dynamic-mechanical and thermomechanical properties of the composites were evaluated. CNFs with a diameter of 70-90 nm were obtained. Eucalyptus sp. has higher α-cellulose content than Pinus sp. fibers. The crystallinity of the cellulose pulps decreased after grinding. However, high values were still obtained. The chemical composition of the fibers was not significantly altered by the grinding process. Eucalyptus sp. CNF composites had water absorption close to the neat resin at 1 wt% filler. The dynamic-mechanical properties of Eucalyptus sp. CNFs were slightly increased and the thermal stability was improved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. A longer stay for the kissing disease: epidemiology of bacterial tonsillitis and infectious mononucleosis over a 20-year period.

    PubMed

    Lennon, P; Saunders, J; Fenton, J E

    2013-02-01

    Anecdotally, infectious mononucleosis is considered a more severe infection than bacterial tonsillitis, requiring a longer hospital stay. However, there is little in the literature comparing the epidemiology of the two conditions. This study aimed to compare the epidemiology of bacterial tonsillitis and infectious mononucleosis, in particular any differences in the length of in-patient stay. The hospital in-patient enquiry system was used to analyse patients admitted with bacterial tonsillitis and infectious mononucleosis between 1990 and 2009 inclusive. There was a total of 3435 cases over the 20 years: 3064 with bacterial tonsillitis and 371 with infectious mononucleosis. The mean length of stay was 3.22 days for bacterial tonsillitis and 4.37 days for infectious mononucleosis. The median length of stay for each condition was compared using the Mann-Whitney U non-parametric test, and a significant difference detected (p < 0.001). Patients with infectious mononucleosis have a significantly longer stay in hospital than those with bacterial tonsillitis.

  1. Lipase-catalyzed ring-opening polymerization of lactones to polyesters and its mechanistic aspects.

    PubMed

    Namekawa, S; Suda, S; Uyama, H; Kobayashi, S

    1999-01-01

    Lipase catalysis induced a ring-opening polymerization of lactones with different ring-sizes. Small-size (four-membered) and medium-size lactones (six- and seven-membered) as well as macrolides (12-, 13-, 16-, and 17-membered) were subjected to lipase-catalyzed polymerization. The polymerization behaviors depended primarily on the lipase origin and the monomer structure. The macrolides showing much lower anionic polymerizability were enzymatically polymerized faster than epsilon-caprolactone. The granular immobilized lipase derived from Candida antartica showed extremely efficient catalysis in the polymerization of epsilon-caprolactone. Single-step terminal functionalization of the polyester was achieved by initiator and terminator methods. The enzymatic polymerizability of lactones was quantitatively evaluated by Michaelis-Menten kinetics.

  2. Inclusive indoor play: an approach to developing inclusive design guidelines.

    PubMed

    Mullick, Abir

    2013-01-01

    The purpose of the Inclusive Indoor Play study was to learn about indoor play and develop design guidelines to inform design of inclusive playthings. Children with and without disabilities, parents, teachers, therapists, daycare owners and designers. Focus group interviews; Children's drawings; and Indoor play simulation. The major findings suggest that: 1) play should encourage a child's creativity and develop imagination, 2) inclusive play concept must be employed to design playthings for children with wide age group, 3) inclusive designs improve usability, broaden market appeal, and increase user base, and 4) customizable playthings help children with and without disabilities personalize play situations. Three play principles provide new directions to designing inclusive playthings: 1) offer many play opportunities, 2) provide many modes of play, and 3) include many levels of play challenges. Inclusive Design Guidelines were developed from the findings of three studies: Focus group interviews, Children's drawings, and Play simulation. The guidelines served as useful tools for inclusive design and they were employed to design of six indoor playthings. The playthings were instrumental in promoting social inclusion and they met the criteria of the Inclusive Indoor Play project.

  3. Friction and wear performance of some thermoplastic polymers and polymer composites against unsaturated polyester

    NASA Astrophysics Data System (ADS)

    Unal, H.; Mimaroglu, A.; Arda, T.

    2006-09-01

    Wear experiments have been carried out with a range of unfilled and filled engineering thermoplastic polymers sliding against a 15% glass fibre reinforced unsaturated polyester polymer under 20, 40 and 60 N loads and 0.5 m/s sliding speed. Pin materials used in this experimental investigation are polyamide 66 (PA 66), poly-ether-ether-ketone (PEEK) and aliphatic polyketone (APK), glass fibre reinforced polyamide 46 (PA 46 + 30% GFR), glass fibre reinforced polytetrafluoroethylene (PTFE + 17% GFR), glass fibre reinforced poly-ether-ether-ketone (PEEK + 20% GFR), glass fibre reinforced poly-phylene-sulfide (PPS + 30% GFR), polytetrafluoroethylene filled polyamide 66 (PA 66 + 10% PTFE) and bronze filled pofytetrafluoroethylene (PTFE + 25% bronze) engineering polymers. The disc material is a 15% glass fibre reinforced unsaturated polyester thermoset polymer produced by Bulk Moulding Compound (BMC). Sliding wear tests were carried out on a pin-on-disc apparatus under 0.5 m/s sliding speed and load values of 20, 40 and 60 N. The results showed that the highest specific wear rate is for PPS + 30% GFR with a value of 1 × 10 -11 m 2/N and the lowest wear rate is for PTFE + 17% GFR with a value of 9.41 × 10 -15 m 2/N. For the materials and test conditions of this investigation, apart from polyamide 66 and PA 46 + 30% GFR polymers, the coefficient of friction and specific wear rates are not significantly affected by the change in load value. For polyamide 66 and PA 46 + 30% GFR polymers the coefficient of friction and specific wear rates vary linearly with the variation in load values.

  4. [Aortic reconstruction with graft materials resistant to bacterial infections].

    PubMed

    Hassen-Khodja, Réda; Sadaghianloo, Nirvana; Jean-Baptiste, Élixène

    2013-01-01

    Synthetic graft infection is a rare but extremely serious complication of aortic reconstruction procedures, with morbidity-mortality rates as high as 60 %. Some of the proteins (albumin, gelatin, collagen) used to coat polyester graft materials can establish ionic bonds with antibiotics or can capture antiseptics such as triclosan or ionic silver in their matrices. These active substances are then released from the graft, at varying rates, during the coating degradation that takes place during the weeks following polyester graft implantation in living tissues. Rifampin-bonded prostheses have proved effective against S. aureus and S. epidermidis in several canine models of synthetic aortic graft infection. Rifampin-bonded grafts have also been used successfully in patients with synthetic aortic graft infection by low-virulence bacteria. However, their effectiveness may be limited by the diverse and changing ecology of synthetic aortic graft infections, with an increasing prevalence of multidrug-resistant bacteria and polymicrobial infections. These include species that are naturally, or are likely to become, resistant to rifampin. We evaluated silver-ion-bonded prostheses in this setting but observed a disappointingly high mid-term rate of recurrent infections. Over the past few years we have been involved in the development of polyester vascular prostheses functionalized with a hydroxypropyl-β-cyclodextrin polymeric matrix that can capture and elute several therapeutic agents. The results are promising, as these prostheses enable the sustained release of various antibiotics in amounts several times their minimum inhibitory concentrations. This provides a unique opportunity to functionalize materials for aortic graft reconstruction, based on epidemiological data or individual bacteriological findings.

  5. Enzyme and metabolic engineering for the production of novel biopolymers: crossover of biological and chemical processes.

    PubMed

    Matsumoto, Ken'ichiro; Taguchi, Seiichi

    2013-12-01

    The development of synthetic biology has transformed microbes into useful factories for producing valuable polymers and/or their precursors from renewable biomass. Recent progress at the interface of chemistry and biology has enabled the production of a variety of new biopolymers with properties that substantially differ from their petroleum-derived counterparts. This review touches on recent trials and achievements in the field of biopolymer synthesis, including chemo-enzymatically synthesized aliphatic polyesters, wholly biosynthesized lactate-based polyesters, polyhydroxyalkanoates and other unusual bacterially synthesized polyesters. The expanding diversities in structure and the material properties of biopolymers are key for exploring practical applications. The enzyme and metabolic engineering approaches toward this goal are discussed by shedding light on the successful case studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

    NASA Astrophysics Data System (ADS)

    Kan, C. W.; Kwong, C. H.; Ng, S. P.

    2015-08-01

    Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

  7. Enhanced expression and purification of camelid single domain VHH antibodies from classical inclusion bodies.

    PubMed

    Maggi, Maristella; Scotti, Claudia

    2017-08-01

    Single domain antibodies (sdAbs) are small antigen-binding domains derived from naturally occurring, heavy chain-only immunoglobulins isolated from camelid and sharks. They maintain the same binding capability of full-length IgGs but with improved thermal stability and permeability, which justifies their scientific, medical and industrial interest. Several described recombinant forms of sdAbs have been produced in different hosts and with different strategies. Here we present an optimized method for a time-saving, high yield production and extraction of a poly-histidine-tagged sdAb from Escherichia coli classical inclusion bodies. Protein expression and extraction were attempted using 4 different methods (e.g. autoinducing or IPTG-induced soluble expression, non-classical and classical inclusion bodies). The best method resulted to be expression in classical inclusion bodies and urea-mediated protein extraction which yielded 60-70 mg/l bacterial culture. The method we here describe can be of general interest for an enhanced and efficient heterologous expression of sdAbs for research and industrial purposes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Inclusive health.

    PubMed

    Maclachlan, Malcolm; Khasnabis, Chapal; Mannan, Hasheem

    2012-01-01

    We propose the concept of Inclusive Health to encapsulate the Health for All ethos; to build on the rights-based approach to health; to promote the idea of inclusion as a verb, where a more proactive approach to addressing distinctive and different barriers to inclusion is needed; and to recognise that new initiatives in human resources for health can offer exciting and innovative ways of healthcare delivery. While Inclusive Education has become a widely recognised and accepted concept, Health for All is still contested, and new thinking is required to develop its agenda in line with contemporary developments. Inclusive Health refers both to who gets health care and to who provides it; and its ethos resonates strongly with Jefferson's assertion that 'there is nothing more unequal, than the equal treatment of unequal people'. We situate the timeliness of the Inclusive Health concept with reference to recent developments in the recognition of the rights of people with disability, in the new guidelines for community-based rehabilitation and in the World Report on Disability. These developments offer a more inclusive approach to health and, more broadly, its inter-connected aspects of wellbeing. A concept which more proactively integrates United Nations conventions that recognise the importance of difference - disability, ethnicity, gender, children - could be of benefit for global healthcare policy and practice. © 2011 Blackwell Publishing Ltd.

  9. Elucidation of a side reaction occurring during nitroxide-mediated polymerization of cyclic ketene acetals by tandem mass spectrometric end-group analysis of aliphatic polyesters.

    PubMed

    Albergaria Pereira, Bruna de Fátima; Tardy, Antoine; Monnier, Valérie; Guillaneuf, Yohann; Gigmes, Didier; Charles, Laurence

    2015-12-15

    In order to prevent side reactions while developing new polymerization processes, their mechanism has to be understood and one first key insight is the structure of the end-groups in polymeric by-products. The synthetic method scrutinized here is the nitroxide-mediated polymerization (NMP) of a cyclic ketene acetal, a promising alternative process to the production of polyesters. Polymer end-group characterization was performed by mass spectrometry (MS), combining elemental composition information derived from accurate mass data in the MS mode with fragmentation features recorded in the MS/MS mode. Electrospray was used as the ionization method to ensure the integrity of original chain terminations and a quadrupole time-of-flight (QTOF) instrument was employed for high-resolution mass measurements in both MS and tandem mass spectrometry (MS/MS) modes. Occurrence of side reactions in the studied polymerization method, first evidenced by an unusual increase in dispersity with conversion, was confirmed in MS with the detection of two polymeric impurities in addition to the expected species. Fragmentation rules were first established for this new polyester family in order to derive useful structural information from MS/MS data. In addition to a usual NMP by-product, the initiating group of the second polymeric impurities revealed the degradation of the nitroxide moiety. Unambiguous MS/MS identification of end-groups in by-products sampled from the polymerization medium allowed an unusual side reaction to be identified during the NMP preparation of polyesters. On-going optimization of the polymerization method aims at preventing this undesired process. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Inclusion.

    ERIC Educational Resources Information Center

    Nathanson, Jeanne H., Ed.

    1992-01-01

    This theme journal issue focuses on current activities of the Office of Special Education and Rehabilitative Services which stress inclusion of students with disabilities in the mainstream. It begins with a message from the Assistant Secretary, Robert R. Davila which examines the full meaning of an "inclusive" education. Next, Barbara…

  11. Flammability and thermal properties studies of nonwoven flax reinforced acrylic based polyester composites

    NASA Astrophysics Data System (ADS)

    Rasyid, M. F. Ahmad; Salim, M. S.; Akil, H. M.; Ishak, Z. A. Mohd.

    2017-12-01

    In the pursuit of green and more sustainable product, natural fibre reinforced composites originating from renewable resources has gained interest in recent years. These natural fibres exhibit good mechanical properties, low production costs, and good environmental properties. However, one of the disadvantages of natural fibre reinforced composites is their high flammability that limits their application in many fields. Within this research, the effect of sodium silicate on the flammability and thermal properties of flax reinforced acrylic based polyester composites has been investigated. Sodium silicate is applied as binder and flame retardant system in impregnation process of the natural flax fiber mats. The addition of sodium silicate significantly improved the flame retardant efficiency but reduced the degree of crosslinking of the composites.

  12. Effect of bacterial collagenase on resin-dentin bonds degradation.

    PubMed

    Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; Aguilera, Fátima S; Yamauti, Monica; Pashley, David H; Tay, Franklin

    2007-12-01

    The objective of this study is to evaluate the effect of a bacterial collagenase on the degradation of resin-dentin bonds. Human dentin surfaces were bonded with: an etch-&-rinse self-priming adhesive (SB), a two-step self-etching primer/adhesive (SEB), and a 1-step self-etching adhesive (OUB). Composite build-ups were constructed. The bonded teeth were stored (24 h, 3 months, 1 year) in distilled water or in a buffered bacterial collagenase solution. Half of the specimens were stored as intact bonded teeth (Indirect Exposure/IE). The other half were sectioned into beams prior to storage (Direct Exposure/DE). After storage the intact teeth were sectioned into beams and all specimens were tested for microtensile bond strengths (MTBS). ANOVA and multiple comparisons tests were performed. Fractographic analysis was performed by scanning electron microscopy. The inclusion of bacterial collagenase in the storing solution did not lower the MTBS values over those seen in specimens stored in water. SB and SEB bonds strength were equal, and were superior to OUB. After 3 months of DE, SB and OUB bonded specimens showed decreases in MTBS; similar reductions required 1 year for SEB/DE. MTBS did not decrease in IE specimens except for OUB. Resin and collagen dissolution were evident in DE groups after storing.

  13. Questioning Secondary Inclusive Education: Are Inclusive Classrooms Always Best for Students?

    ERIC Educational Resources Information Center

    Tkachyk, Ruth Elizabeth

    2013-01-01

    Educating students with special needs in inclusive settings has become a priority for westernized governments as they strive to create more inclusive societies. While recognizing the societal benefits of inclusion, teachers and parents question whether or not implementation of full inclusion will come at the expense of learners' individual…

  14. Limits to Inclusion

    ERIC Educational Resources Information Center

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  15. Rheological and Thermal Properties of Bio-based Hyperbranched Polyesters

    NASA Astrophysics Data System (ADS)

    Bubeck, Robert; Dumitrascu, Adina; Zhang, Tracy; Smith, Patrick

    Hyperbranched poly(ester)s (HBPEs) of designed molecular structures and targeted molecular weight can be prepared from a variety of multi-functional acids and alcohols. These polymers find application in the areas of coatings and rheology modifiers for coatings. These functional polymers can be synthesized in variety of architectures, possessing either hydroxyl or carboxyl reactive end-groups suitable for the attachment of active entities. The rheological characteristics as related to variation in molecular structure were determined using cone and plate or couette geometries. Viscosities of the HBPEs were found to be near Newtonian. HB polymers permit the control of Tg that is not as readily attained with linear polymers. Accordingly, Tg and viscosity are affected little as a function of Mw but vary dramatically with the nature of the end-groups, are highly dependent on hydrogen bonding of the hydroxyl end groups, and decrease dramatically with the incorporation of aliphatic end-caps. The thermal properties and the degradation characteristics of the HBPEs were determined. Thermal degradation of the hydroxyl-terminal HBPEs is initiated by dehydrative ether formation (crosslinking) while decarboxylation is the initial decomposition event for the carboxyl-terminal polymers. Midland, MI Campus.

  16. Study of the effect of surface treatment of kenaf fiber on chemical structure and water absorption of kenaf filled unsaturated polyester composite

    NASA Astrophysics Data System (ADS)

    Salem, I. A. S.; Rozyanty, A. R.; Betar, B. O.; Adam, T.; Mohammed, M.; Mohammed, A. M.

    2017-10-01

    In this research, unsaturated polyester/kenaf fiber (UP/KF) composites was prepared by using hand lay-up process. The effect of surface treatment of kenaf fiber on mechanical properties of kenaf filled unsaturated polyester composites were studied. Different concentrationsof stearic acid (SA) were applied, i.e. 0, 0.4, and 0.8 wt%. The Fourier transform infrared (FT-IR) spectra of kenaf fiber shows high intensity of the peak around 3300-3400 cm-1, which is attributed to the hydrogen bonded O-H stretching. However, the treated kenaf fiber with stearic acid shows the elimination of O-H group and this peak is vanished. This is due to the reaction of (-COOH) group of stearic with (-OH) group of kenaf fiber. The results of water absorption study revealed that increasing the loading of KF in the composite will result is increasing the tendency to absorb water. However, the absorption was significantly decreased after treatment with stearic acid as well as the time to reach to the equilibrium state.

  17. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    NASA Astrophysics Data System (ADS)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2018-06-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  18. Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures

    PubMed Central

    Zafar, Urooj; Houlden, Ashley

    2013-01-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

  19. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    NASA Astrophysics Data System (ADS)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2017-08-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  20. Fungal communities associated with the biodegradation of polyester polyurethane buried under compost at different temperatures.

    PubMed

    Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D

    2013-12-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future.

  1. Contribution of soil esterase to biodegradation of aliphatic polyester agricultural mulch film in cultivated soils.

    PubMed

    Yamamoto-Tamura, Kimiko; Hiradate, Syuntaro; Watanabe, Takashi; Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Yarimizu, Tohru; Kitamoto, Hiroko

    2015-01-01

    The relationship between degradation speed of soil-buried biodegradable polyester film in a farmland and the characteristics of the predominant polyester-degrading soil microorganisms and enzymes were investigated to determine the BP-degrading ability of cultivated soils through characterization of the basal microbial activities and their transition in soils during BP film degradation. Degradation of poly(butylene succinate-co-adipate) (PBSA) film was evaluated in soil samples from different cultivated fields in Japan for 4 weeks. Both the degradation speed of the PBSA film and the esterase activity were found to be correlated with the ratio of colonies that produced clear zone on fungal minimum medium-agarose plate with emulsified PBSA to the total number colonies counted. Time-dependent change in viable counts of the PBSA-degrading fungi and esterase activities were monitored in soils where buried films showed the most and the least degree of degradation. During the degradation of PBSA film, the viable counts of the PBSA-degrading fungi and the esterase activities in soils, which adhered to the PBSA film, increased with time. The soil, where the film was degraded the fastest, recorded large PBSA-degrading fungal population and showed high esterase activity compared with the other soil samples throughout the incubation period. Meanwhile, esterase activity and viable counts of PBSA-degrading fungi were found to be stable in soils without PBSA film. These results suggest that the higher the distribution ratio of native PBSA-degrading fungi in the soil, the faster the film degradation is. This could be due to the rapid accumulation of secreted esterases in these soils.

  2. Biodegradable polyester-based eco-composites containing hemp fibers modified with macrocyclic oligomers

    NASA Astrophysics Data System (ADS)

    Conzatti, Lucia; Utzeri, Roberto; Hodge, Philip; Stagnaro, Paola

    2016-05-01

    An original compatibilizing pathway for hemp fibers/poly(1,4-butylene adipate-co-terephtalate) (PBAT) eco-composites was explored exploiting the capability of macrocyclic oligomers (MCOs), obtained by cyclodepolymerization (CDP) of PBAT at high dilution, of being re-converted into linear chains by entropically-driven ring-opening polymerization (ED-ROP) that occurs simply heating the MCOS in the bulk. CDP reaction of PBAT was carried out varying solvent, catalyst and reaction time. Selected MCOs were used to adjust the conditions of the ED-ROP reaction. The best experimental conditions were then adopted to modify hemp fibers. Eco-composites based on PBAT and hemp fibers as obtained or modified with PBAT macrocyclics or oligomers were prepared by different process strategies. The best fiber-PBAT compatibility was observed when the fibers were modified with PBAT oligomers before incorporation in the polyester matrix.

  3. Functional polyester materials with tunable degradability: Investigations into the use of reductive amination, ketoxime ether, and hydrazone linkages for functionalization, covalent stabilization and crosslinking of poly(epsilon-caprolactone) materials

    NASA Astrophysics Data System (ADS)

    van Horn, Brooke Angela

    Aliphatic polyesters represent one class of degradable, polymeric materials that is receiving significant attention in the search for, and design of, biocompatible and bioresorbable synthetic substances. Functional and crosslinked polyesters, having potential biomedical value, are the target of many avenues of current research. This dissertation work expands the utility of a specific aliphatic polyester, poly(epsilon-caprolactone-co-2-oxepane-1,5-dione) (P(CL-co-OPD)), which contains backbone ketone units that can be reacted with various functional, nucleophilic agents. Results presented in this dissertation convey both the successes had and the challenges encountered in the employment of different "iminyl" chemistries for the synthesis of functional and crosslinked materials. Specifically, the ketone-functionalized polyester was investigated as a general substrate designed to undergo solution-state intramolecular crosslinking and functionalization upon reductive amination with 1,6-hexanediamine and hexylamine, respectively, in the presence of NaCNBH3. Through detailed analysis of the products from these reactions, and simpler systems including small molecule model compounds, the polymeric gamma-keto ester functionality was determined to be incompatible with the reductive amination chemistry, resulting in chain cleavage via intramolecular lactam formation. Subsequent investigation of ketoxime ether formation using synthetic model hydroxylamines, 1-aminooxydodecane and 1,6-bis(aminooxy)hexane, in solution and in the presence of an acid catalyst, resulted in the targeted graft and crosslinked particulate/gel materials, respectively. With the significant interest in the development of synthetic polymer materials of increasing degrees of complexity, attention has been focused on the efficient and high-yielding conversion of polyesters into multi-functional materials. Facile conjugation of aminooxy- and sulfonyl hydrazide model ligands with P(CL-co-OPD) were also

  4. Overall and specific migration from multilayer high barrier food contact materials - kinetic study of cyclic polyester oligomers migration.

    PubMed

    Úbeda, Sara; Aznar, Margarita; Vera, Paula; Nerín, Cristina; Henríquez, Luis; Taborda, Laura; Restrepo, Claudia

    2017-10-01

    Most multilayer high barrier materials used in food packaging have a polyurethane adhesive layer in their structures. In order to assess the safety of these materials, it is important to determine the compounds intentionally added to the adhesives (IAS) as well as those non-intentionally added substances (NIAS). During the manufacture of polyurethane adhesives, some by-products can be formed, such as cyclic polyester oligomers coming from the reaction between dicarboxylic acids and glycols. Since these compounds are not listed in the Regulation 10/2011/EU, they should not be found in migration above 0.01 mg/kg of simulant. In this study two flexible multilayer packaging materials were used and migration was evaluated in simulant A (ethanol 10% v/v), simulant B (acetic acid 3% w/v) and simulant ethanol 95% v/v during 10 days at 60ºC. Identification and quantification of non-volatile compounds was carried out by UPLC-MS-QTOF. Most of migrants were oligomers such as cyclic polyesters and caprolactam oligomers. Overall migration and specific migration of adipic acid-diethylene glycol and phthalic acid-diethylene glycol were monitored over time and analysed by UPLC-MS-TQ. In most cases, ethanol 95% v/v was the simulant with the highest concentration values. Overall migration kinetics followed a similar pattern than specific migration kinetics.

  5. Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites

    NASA Technical Reports Server (NTRS)

    Lark, R. L.; Chamis, C. C.

    1983-01-01

    The static and cyclic load behavior of transverse filament tape (TFT) fiberglass/epoxy and TFY fiberglass/polyester composites, intended for use in the design of low-cost wind turbine blades, are presented. The data behavior is also evaluated with respect to predicted properties based on an integrated hygrothermomechanical response theory. Experimental TFT composite data were developed by the testing of laminates made by using composite layups typical of those used for the fabrication of TFT fiberglass wind turbine blades. Static properties include tension, compression, and interlaminar shear strengths at ambient conditions and at high humidity/elevated temperature conditions after a 500 hour exposure. Cyclic fatigue data were obtained using similar environmental conditions and a range of cyclic stresses. The environmental (temperature and moisture) and cyclic load effects on composite strength degradation are subsequently compared with the predictions obtained by using the composite life/durability theory. The results obtained show that the predicted hygrothermomechanical environmental effects on TFT composites are in good agreement with measured data for various properties including fatigue at different cyclic stresses.

  6. Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy-Efficient Wood-Plastic Composites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    David N. Thompson, Robert W. Emerick, Alfred B. England, James P. Flanders, Frank J. Loge, Katherine A. Wiedeman, Michael P. Wolcott

    The forestry, wood and paper industries in the United States provide thousands of productive well-paying jobs; however, in the face of the recent economic downturn it faces significant challenges in remaining economically viable and competitive. To compete successfully on a global market that is increasingly driven by the need for sustainable products and practices, the industry must improve margins and diversify product lines while continuing to produce the staple products. One approach that can help to accomplish this goal sustainably is the forest biorefinery. In the forest biorefinery, traditional waste streams are utilized singly or in combination to manufacture additionalmore » products in a profitable and environmentally sustainable manner. In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. Renewable microbial polyesters are not currently used in WFRTCs primarily because their production costs are several times higher than those of conventional petrochemical-derived plastics, limiting their use to small specialty markets. The strategy for this project was to economically produce WFRTCs using microbial polyesters by reducing or eliminating the most costly steps in the bio-plastic production. This would be achieved by producing them in and from waste effluents from the municipal and forest products sectors, and by eliminating the costly purification steps. After production the plasticladen biosolids would be dried and used directly to replace petroleum

  7. Seasonal dynamics of bacterial meningitis: a time-series analysis.

    PubMed

    Paireau, Juliette; Chen, Angelica; Broutin, Helene; Grenfell, Bryan; Basta, Nicole E

    2016-06-01

    Bacterial meningitis, which is caused mainly by Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae, inflicts a substantial burden of disease worldwide. Yet, the temporal dynamics of this disease are poorly characterised and many questions remain about the ecology of the disease. We aimed to comprehensively assess seasonal trends in bacterial meningitis on a global scale. We developed the first bacterial meningitis global database by compiling monthly incidence data as reported by country-level surveillance systems. Using country-level wavelet analysis, we identified whether a 12 month periodic component (annual seasonality) was detected in time-series that had at least 5 years of data with at least 40 cases reported per year. We estimated the mean timing of disease activity by computing the centre of gravity of the distribution of cases and investigated whether synchrony exists between the three pathogens responsible for most cases of bacterial meningitis. We used country-level data from 66 countries, including from 47 countries outside the meningitis belt in sub-Saharan Africa. A persistent seasonality was detected in 49 (96%) of the 51 time-series from 38 countries eligible for inclusion in the wavelet analyses. The mean timing of disease activity had a latitudinal trend, with bacterial meningitis seasons peaking during the winter months in countries in both the northern and southern hemispheres. The three pathogens shared similar seasonality, but time-shifts differed slightly by country. Our findings provide key insight into the seasonal dynamics of bacterial meningitis and add to knowledge about the global epidemiology of meningitis and the host, environment, and pathogen characteristics driving these patterns. Comprehensive understanding of global seasonal trends in meningitis could be used to design more effective prevention and control strategies. Princeton University Health Grand Challenge, US National Institutes of Health (NIH

  8. Seasonal dynamics of bacterial meningitis: a time-series analysis

    PubMed Central

    Paireau, Juliette; Chen, Angelica; Broutin, Helene; Grenfell, Bryan; Basta, Nicole E

    2017-01-01

    Summary Background Bacterial meningitis, which is caused mainly by Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae, inflicts a substantial burden of disease worldwide. Yet, the temporal dynamics of this disease are poorly characterised and many questions remain about the ecology of the disease. We aimed to comprehensively assess seasonal trends in bacterial meningitis on a global scale. Methods We developed the first bacterial meningitis global database by compiling monthly incidence data as reported by country-level surveillance systems. Using country-level wavelet analysis, we identified whether a 12 month periodic component (annual seasonality) was detected in time-series that had at least 5 years of data with at least 40 cases reported per year. We estimated the mean timing of disease activity by computing the centre of gravity of the distribution of cases and investigated whether synchrony exists between the three pathogens responsible for most cases of bacterial meningitis. Findings We used country-level data from 66 countries, including from 47 countries outside the meningitis belt in sub-Saharan Africa. A persistent seasonality was detected in 49 (96%) of the 51 time-series from 38 countries eligible for inclusion in the wavelet analyses. The mean timing of disease activity had a latitudinal trend, with bacterial meningitis seasons peaking during the winter months in countries in both the northern and southern hemispheres. The three pathogens shared similar seasonality, but time-shifts differed slightly by country. Interpretation Our findings provide key insight into the seasonal dynamics of bacterial meningitis and add to knowledge about the global epidemiology of meningitis and the host, environment, and pathogen characteristics driving these patterns. Comprehensive understanding of global seasonal trends in meningitis could be used to design more effective prevention and control strategies. Funding Princeton University Health

  9. Construction of Bimetallic ZIF-Derived Co-Ni LDHs on the Surfaces of GO or CNTs with a Recyclable Method: Toward Reduced Toxicity of Gaseous Thermal Decomposition Products of Unsaturated Polyester Resin.

    PubMed

    Hou, Yanbei; Qiu, Shuilai; Hu, Yuan; Kundu, Chanchal Kumar; Gui, Zhou; Hu, Weizhao

    2018-05-30

    This work proposed an idea of recycling in preparing Co-Ni layered double hydroxide (LDH)-derived flame retardants. A novel and feasible method was developed to synthesize CO-Ni LDH-decorated graphene oxide (GO) and carbon nanotubes (CNTs), by sacrificing bimetal zeolitic imidazolate frameworks (ZIFs). Organic ligands that departed from ZIFs were recyclable and can be reused to synthesize ZIFs. ZIFs, as transitional objects, in situ synthesized on the surfaces of GO or CNTs directly suppressed the re-stacking of the carbides and facilitated the preparation of GO@LDHs and CNTs@LDHs. As-prepared hybrids catalytically reduced toxic CO yield during the thermal decomposition of unsaturated polyester resin (UPR). What is more, the release behaviors of aromatic compounds were also suppressed during the pyrolysis process of UPR composites. The addition of GO@LDHs and CNTs@LDHs obviously inhibited the heat release and smoke emission behaviors of the UPR matrix during combustion. Mechanical properties of the UPR matrix also improved by inclusion of the carbides derivatives. This work paved a feasible method to prepare well-dispersed carbides@Co-Ni LDH nanocomposites with a more environmentally friendly method.

  10. Inclusive Education in Italy: Description and Reflections on Full Inclusion

    ERIC Educational Resources Information Center

    Anastasiou, Dimitris; Kauffman, James M.; Di Nuovo, Santo

    2015-01-01

    Inclusion of students with disabilities when appropriate is an important goal of special education for students with special needs. Full inclusion, meaning no education for any child in a separate setting, is held to be desirable by some, and Italy is likely the nation with an education system most closely approximating full inclusion on the…

  11. Tensile properties and translaminar fracture toughness of glass fiber reinforced unsaturated polyester resin composites aged in distilled and salt water

    NASA Astrophysics Data System (ADS)

    Sugiman, Gozali, M. Hulaifi; Setyawan, Paryanto Dwi

    2016-03-01

    Glass fiber reinforced polymer has been widely used in chemical industry and transportation due to lightweight and cost effective manufacturing. However due to the ability to absorb water from the environment, the durability issue is of interest for up to days. This paper investigated the water uptake and the effect of absorbed water on the tensile properties and the translaminar fracture toughness of glass fiber reinforced unsaturated polyester composites (GFRP) aged in distilled and salt water up to 30 days at a temperature of 50°C. It has been shown that GFRP absorbed more water in distilled water than in salt water. In distilled water, the tensile strength of GFRP tends to decrease steeply at 7 days and then slightly recovered for further immersion time. In salt water, the tensile strength tends to decrease continually up to 30 days immersion. The translaminar fracture toughness of GFRP aged in both distilled and salt-water shows the similar behavior. The translaminar fracture toughness increases after 7 days immersion and then tends to decrease beyond that immersion time. In the existence of ionics content in salt water, it causes more detrimental effect on the mechanical properties of fiberglass/unsaturated polyester composites compared to that of distilled water.

  12. Temporal trends in paediatric bacterial meningitis in a tropical Australian region: 1992-2014.

    PubMed

    White, Stephanie; Katf, Hala; Baird, Rob; Francis, Joshua

    2018-05-13

    The epidemiology of community-acquired bacterial meningitis has changed following the introduction of routine immunisation against common causative organisms. Indigenous children living in the Northern Territory, Australia, have high rates of bacterial infections. This study describes changes in the epidemiology of childhood bacterial meningitis and the distribution of the burden of disease in the Top End. A retrospective review of cases derived from hospital medical records and laboratory data was performed. Inclusion criteria were children aged 3 months to 14 years of age, admitted to Royal Darwin Hospital between 1992 and 2014 and diagnosed with bacterial meningitis. Annual incidence of bacterial meningitis and the distribution of causative pathogens are described. Demographic data, investigations, treatment and outcomes were compared between Indigenous and non-Indigenous children. There were 137 cases of childhood bacterial meningitis identified over the 23-year period. The incidence reduced from 21 per 100 000 children per year for 1992-2002 to 11 per 100 000 per year for 2003-2014 (P = 0.0025). Haemophilus influenzae type b, Streptococcus pneumoniae and Neisseria meningitidis were the most common causative organisms, with a reduction in cases for each pathogen observed across the study period. Indigenous children were over-represented (104/137, 76%). Case fatality rate was 8% (11/137); 91% of fatal cases presented to a remote facility. The incidence of childhood bacterial meningitis has declined in the Northern Territory of Australia, but Indigenous children are disproportionately affected. Routine immunisation is beneficial for all, although further efforts to 'Close the Gap' between health outcomes in Indigenous and non-Indigenous Australians is required. © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  13. In vivo deuteration of a native bacterial biopolymer for structural elucidation using SANS

    NASA Astrophysics Data System (ADS)

    Holden, P. J.; Russell, R. A.; Stone, D. J. M.; Garvey, C. J.; Foster, L. J. R.

    2004-07-01

    In order to facilitate future structural studies, biodeuteration of bacterial polyhydroxyalkanoates (PHAs) was investigated. We report here the in vivo deuteration of poly 3-hydroxyoctanoate (PHO) produced by its native host, the bacterium Pseudomonas oleovorans. Bacterial biomass was produced in bioreactor studies by growth on hydrogenated substrates and PHO was subsequently produced intracellularly (10-20% w/w) during batch fed growth on deuterated octanoic acid under oxygen limitation. GC-MS analyses of the PHO demonstrated that 13 of the 15 hydrogen atoms had been replaced with deuterium (except in position 3), the remaining two hydrogen presumably being derived from water. A SANS contrast variation study was conducted on whole cells and the results indicate the potential to discriminate inclusion bodies formed from deuterated precursor from an otherwise hydrogenated background.

  14. Enhancing the value of commodity polymers: Part 1. Structure-property relationships in composite materials based on maleated polypropylene/inorganic phosphate glasses. Part 2. New value-added applications for polyesters

    NASA Astrophysics Data System (ADS)

    Gupta, Mohit

    The first part of the thesis (Chapters 2 & 3) describes a new class of organic polymer/inorganic glass composite materials with property improvements that are impossible to achieve with classical polymer blends or composites. These materials exhibit good processability, superior mechanical performance, good thermal stability, and have excellent gas barrier properties. Low glass transition temperature phosphate glasses (Pglass) are used as inorganic fillers and slightly maleated polypropylene is used as the organic polymer matrix. The Pglass, which was dispersed as spherical droplets in the unoriented composites can be elongated into high aspect ratio platelets during the biaxial stretching process. Biaxially oriented films exhibited a brick wall type microstructure with highly aligned inorganic platelets in a ductile organic matrix and the oxygen barrier properties are significantly improved due to presence of Pglass platelets as impermeable inclusions. Mechanical properties of the biaxially oriented films showed significant improvements compared to neat polymer due to uniform dispersion of the Pglass platelets. Properly dispersed and aligned platelets have proven to be very effective for increasing the composite modulus. These developed materials therefore show promise to help fulfill the ever increasing demand for new advanced materials for a wide variety of advanced packaging applications because of their gas barrier properties, flexibility, transparency, mechanical strength and performance under humid conditions. The second part of the thesis (Chapters 4 & 5) describes new value-added applications for polyesters. Chapter 4 reports a novel process for the decolorization of green and blue colored PET bottle flakes using hydrogen peroxide. The decolorized flakes were characterized for color, intrinsic viscosity values. Decolorized flakes exhibited color values similar to those of colorless recycled PET and even though IV values decreased, bleached flakes still

  15. Phenotypic variability within the inclusion body spectrum of basophilic inclusion body disease and neuronal intermediate filament inclusion disease in frontotemporal lobar degenerations with FUS-positive inclusions.

    PubMed

    Gelpi, Ellen; Lladó, Albert; Clarimón, Jordi; Rey, Maria Jesús; Rivera, Rosa Maria; Ezquerra, Mario; Antonell, Anna; Navarro-Otano, Judith; Ribalta, Teresa; Piñol-Ripoll, Gerard; Pérez, Anna; Valldeoriola, Francesc; Ferrer, Isidre

    2012-09-01

    Basophilic inclusion body disease and neuronal intermediate filament inclusion disease (NIFID) are rare diseases included among frontotemporal lobar degenerations with FUS-positive inclusions (FTLD-FUS). We report clinical and pathologic features of 2 new patients and reevaluate neuropathologic characteristics of 2 previously described cases, including an early-onset case of basophilic inclusion body disease (aged 38 years) with a 5-year disease course and abundant FUS-positive inclusion bodies and 3 NIFID cases. One NIFID case (aged 37 years) presented with early-onset psychiatric disturbances and rapidly progressive cognitive decline. Two NIFID cases had later onset (aged 64 years and 70 years) and complex neurologic deficits. Postmortem neuropathologic studies in late-onset NIFID cases disclosed α-internexin-positive "hyaline conglomerate"-type inclusions that were positive with 1 commercial anti-FUS antibody directed to residues 200 and 250, but these were negative to amino acids 90 and 220 of human FUS. Early-onset NIFID had similar inclusions that were positive with both commercial anti-FUS antibodies. Genetic testing performed on all cases revealed no FUS gene mutations. These findings indicate that phenotypic variability in NIFID, including clinical manifestations and particular neuropathologic findings, may be related to the age at onset and individual differences in the evolution of lesions.

  16. High-performance liquid chromatographic determination of benzil in air as an indicator of emissions derived from polyester powder coatings.

    PubMed

    Pukkila, J; Kokotti, H; Peltonen, K

    1989-10-06

    A method to estimate occupational exposure to emissions from the curing of polyester powder paints was developed. The method is based on the monitoring only of a certain marker compound in workroom air in order to make the determinations easier. Benzil, reproducibly emitted from all the powders tested, was chosen as the indicator for curing (220 degrees C)-derived emissions. A method for the air sampling and high-performance liquid chromatographic benzil is described. Aspects of the use of marker compounds are discussed.

  17. One-pot refolding of core histones from bacterial inclusion bodies allows rapid reconstitution of histone octamer.

    PubMed

    Lee, Young-Tae; Gibbons, Garrett; Lee, Shirley Y; Nikolovska-Coleska, Zaneta; Dou, Yali

    2015-06-01

    We report an optimized method to purify and reconstitute histone octamer, which utilizes high expression of histones in inclusion bodies but eliminates the time consuming steps of individual histone purification. In the newly modified protocol, Xenopus laevis H2A, H2B, H3, and H4 are expressed individually into inclusion bodies of bacteria, which are subsequently mixed together and denatured in 8M guanidine hydrochloride. Histones are refolded and reconstituted into soluble octamer by dialysis against 2M NaCl, and metal-affinity purified through an N-terminal polyhistidine-tag added on the H2A. After cleavage of the polyhistidine-tag, histone octamer is further purified by size exclusion chromatography. We show that the nucleosomes reconstituted using the purified histone octamer above are fully functional. They serve as effective substrates for the histone methyltransferases DOT1L and MLL1. Small angle X-ray scattering further confirms that the reconstituted nucleosomes have correct structural integration of histone octamer and DNA as observed in the X-ray crystal structure. Our new protocol enables rapid reconstitution of histone octamer with an optimal yield. We expect this simplified approach to facilitate research using recombinant nucleosomes in vitro. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Microbial Degradation Behavior in Seawater of Polyester Blends Containing Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)

    PubMed Central

    Sashiwa, Hitoshi; Fukuda, Ryuji; Okura, Tetsuo; Sato, Shunsuke; Nakayama, Atsuyoshi

    2018-01-01

    The microbial degradation behavior of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and its compound with several polyesters such as poly(butylene adipate-co-telephtharate) (PBAT), poly(butylene succinate) (PBS), and polylactic acid (PLA) in seawater was tested by a biological oxygen demand (BOD) method. PHBHHx showed excellent biodegradation in seawater in this study. In addition, the biodegradation rate of several blends was much influenced by the weight ratio of PHBHHx in their blends and decreased in accordance with the decrement of PHBHHX ratio. The surface morphology of the sheet was important factor for controlling the biodegradation rate of PHBHHx-containing blends in seawater. PMID:29342118

  19. Bacterial prostatitis.

    PubMed

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  20. Bacterial Sialidase

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  1. Thermal properties of poly(urethane-ester-siloxane)s based on hyperbranched polyester

    NASA Astrophysics Data System (ADS)

    Pergal, M. V.; Džunuzović, J. V.; Kićanović, M.; Vodnik, V.; Pergal, M. M.; Jovanović, S.

    2011-12-01

    Novel polyurethanes (PUs) were synthesized using hydroxy-terminated hyperbranched polyester (BH-20) and 4,4'-methylenediphenyl diisocyanate (MDI) as hard segments and hydroxy-terminated ethylene oxide-poly(dimethylsiloxane)-ethylene oxide triblock copolymer (PDMS-EO) as soft segment, with soft segment content ranging from 30 to 60 wt %. The PUs were synthesized by two-step solution polymerization method. The influence of the soft segment content on the structure, swelling behavior and thermal properties of PUs was investigated. According to the results obtained by swelling measurements, the increase of the hard segment content resulted in the increase of the crosslinking density of synthesized samples. DSC results showed that the glass transition temperatures increase from 36 to 65°C with increasing hard segment content. It was demonstrated using thermogravimetric analysis (TGA) that thermal stability of investigated PUs increases with increase of the soft PDMS-EO content. This was concluded from the temperatures corresponding to the 10 wt % loss, which represents the beginning of thermal degradation of samples.

  2. CSF lactate level: a useful diagnostic tool to differentiate acute bacterial and viral meningitis.

    PubMed

    Abro, Ali Hassan; Abdou, Ahmed Saheh; Ustadi, Abdulla M; Saleh, Ahmed Alhaj; Younis, Nadeem Javeed; Doleh, Wafa F

    2009-08-01

    To evaluate the potential role of CSF lactate level in the diagnosis of acute bacterial meningitis and in the differentiation between viral and bacterial meningitis. This was a hospital based observational study, conducted at Infectious Diseases Unit, Rashid Hospital Dubai, United Arab Emirates, from July 2004 to June 2007. The patients with clinical diagnosis of acute bacterial meningitis and who had CSF Gram stain/culture positive, CSF analysis suggestive of bacterial meningitis with negative Gram stain and culture but blood culture positive for bacteria and patients with clinical diagnosis suggestive of viral meningitis supported by CSF chemical analysis with negative Gram stain and culture as well as negative blood culture for bacteria were included in the study. CT scan brain was done for all patients before lumber puncture and CSF and blood samples were collected immediately after admission. CSF chemical analysis including lactate level was done on first spinal tap. The CSF lactate level was tested by Enzymatic Colorimetric method. A total 95 adult patients of acute meningitis (53 bacterial and 42 viral) fulfilled the inclusion criteria. Among 53 bacterial meningitis patients, Neisseria meningitides were isolated in 29 (54.7%), Strept. Pneumoniae in 18 (33.96%), Staph. Aureus in 2 (3.77%), Klebsiell Pneumoniae in 2 (3.77%), Strept. Agalactiae in 1 (1.8%) and E. Coli in 1 (1.8%). All the patients with bacterial meningitis had CSF lactate > 3.8 mmol/l except one, whereas none of the patients with viral meningitis had lactate level > 3.8 mmol/l. The mean CSF lactate level in bacterial meningitis cases amounted to 16.51 +/- 6.14 mmol/l, whereas it was significantly lower in viral group 2.36 +/- 0.6 mmol/l, p < .0001. CSF lactate level was significantly high in bacterial than viral meningitis and it can provide pertinent, rapid and reliable diagnostic information. Furthermore, CSF lactate level can also differentiate bacterial meningitis from viral one in a quick

  3. Box-Behnken design approach towards optimization of activated carbon synthesized by co-pyrolysis of waste polyester textiles and MgCl2

    NASA Astrophysics Data System (ADS)

    Yuan, Zhihang; Xu, Zhihua; Zhang, Daofang; Chen, Weifang; Zhang, Tianqi; Huang, Yuanxing; Gu, Lin; Deng, Haixuan; Tian, Danqi

    2018-01-01

    Pyrolysis activation of waste polyester textiles (WPT) was regarded as a sustainable technique to synthesize multi-pore activated carbons. MgO-template method of using MgCl2 as the template precursor was employed, which possessed the advantages of ideal pore-forming effect and efficient preparation process. The response surface methodology coupled with Box-Behnken design (BBD) was conducted to study the interaction between different variables and optimized preparation conditions of waste polyester textiles based activated carbons. Derived from BBD design results, carbonization temperature was the most significant individual factor. And the maximum specific surface area of 1364 m2/g, which presented a good agreement with the predicted response values(1315 m2/g), was obtained at mixing ratio in MgCl2/WPT, carbonization temperature and time of 5:1, 900 °C and 90 min, respectively. Furthermore, the physicochemical properties of the sample prepared under optimal conditions were carried on utilizing nitrogen adsorption/desorption isotherms, EA, XRD, SEM and FTIR. In addition, the pore-forming mechanism was mainly attributed to the tendency of carbon layer coating on MgO to form pore walls after elimination of MgO and the strong dehydration effect of MgCl2 on WPT.

  4. ANTIBIOTICS IN MANAGEMENT OF STAPHYLOCOCCAL ENDOCARDITIS—With Special Reference to Increasing Bacterial Resistance

    PubMed Central

    Levinson, David C.; Griffith, George C.; Pearson, Harold E.

    1951-01-01

    Eighteen patients with staphylococcal endocarditis were observed at the Los Angeles County Hospital over a 3-year period (1947-49, inclusive). Twelve died. Bacterial sensitivity studies were carried out in 15 of the cases, and there was resistance to penicillin in ten. Aureomycin was effective in two cases of Staphylococcus aureus endocarditis in which there was no response to penicillin therapy. In one case of Staphylococcus aureus endocarditis the organism was resistant to penicillin and developed increasing resistance to aureomycin. PMID:14812349

  5. Poly(ester amide)s based on (L)-lactic acid oligomers and α-amino acids: influence of the α-amino acid side chain in the poly(ester amide)s properties.

    PubMed

    Fonseca, Ana C; Coelho, Jorge F J; Valente, Joana F A; Correia, Tiago R; Correia, Ilídio J; Gil, Maria H; Simões, Pedro N

    2013-01-01

    Novel biodegradable and low cytotoxic poly(ester amide)s (PEAs) based on α-amino acids and (L)-lactic acid (L-LA) oligomers were successfully synthesized by interfacial polymerization. The chemical structure of the new polymers was confirmed by spectroscopic analyses. Further characterization suggests that the α-amino acid plays a critical role on the final properties of the PEA. L-phenylalanine provides PEAs with higher glass transition temperature, whereas glycine enhances the crystallinity. The hydrolytic degradation in PBS (pH = 7.4) at 37 °C also depends on the α-amino acid, being faster for glycine-based PEAs. The cytotoxic profiles using fibroblast human cells indicate that the PEAs did not elicit an acute cytotoxic effect. The strategy presented in this work opens the possibility of synthesizing biodegradable PEAs with low citotoxicity by an easy and fast method. It is worth to mention also that the properties of these materials can be fine-tuned only by changing the α-amino acid.

  6. Inclusive Education: Identifying Teachers' Perceived Stressors in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Brackenreed, Darlene

    2008-01-01

    This research replicates the study conducted by Forlin (2001) in Churchlands, Western Australia. Forlin's Inclusive Education Teacher Stress and Coping Questionnaire was adapted from the original questionnaire to more accurately reflect the language and practice of inclusion in Ontario (Frost & Brackenreed, 2004). The purpose of this study was…

  7. Beyond Physical Inclusion: Teaching Skills in the Community to Enhance Social Inclusion

    ERIC Educational Resources Information Center

    Hall, Carmen L.

    2017-01-01

    Along with the deinstitutionalization movement, supports for persons with Intellectual Disabilities (ID) have shifted to promotion of person-centered supports inclusive in the community. Although successes have occurred regarding physical inclusion, skill building and social inclusion have not fared as well for those with more significant…

  8. Interactions between F-111 Fuselage Fuel Tank Sealants. Part 2. Variation in Performance Properties of Polysulfides after Contact with Polyester Degradation Products,

    DTIC Science & Technology

    1984-08-01

    principally from sebacic acid and neopentyl glycol and that the most significant difference between the sealants was the greater proportion of trihydric...exhaustive hydrolysis of the polyesters would generate sebacic acid and neopentyl glycol , in practice ester units such as (1) which are terminated with both...slight to moderate swelling and softening of the polysulfides with PR-1422 being the most susceptible. Neopentyl glycol suppressed the swelling due to

  9. Enzymatic Degradation of Aromatic and Aliphatic Polyesters by P. pastoris Expressed Cutinase 1 from Thermobifida cellulosilytica

    PubMed Central

    Gamerith, Caroline; Vastano, Marco; Ghorbanpour, Sahar M.; Zitzenbacher, Sabine; Ribitsch, Doris; Zumstein, Michael T.; Sander, Michael; Herrero Acero, Enrique; Pellis, Alessandro; Guebitz, Georg M.

    2017-01-01

    To study hydrolysis of aromatic and aliphatic polyesters cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1) was expressed in P. pastoris. No significant differences between the expression of native Thc_Cut1 and of two glycosylation site knock out mutants (Thc_Cut1_koAsn and Thc_Cut1_koST) concerning the total extracellular protein concentration and volumetric activity were observed. Hydrolysis of poly(ethylene terephthalate) (PET) was shown for all three enzymes based on quantification of released products by HPLC and similar concentrations of released terephthalic acid (TPA) and mono(2-hydroxyethyl) terephthalate (MHET) were detected for all enzymes. Both tested aliphatic polyesters poly(butylene succinate) (PBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were hydrolyzed by Thc_Cut1 and Thc_Cut1_koST, although PBS was hydrolyzed to significantly higher extent than PHBV. These findings were also confirmed via quartz crystal microbalance (QCM) analysis; for PHBV only a small mass change was observed while the mass of PBS thin films decreased by 93% upon enzymatic hydrolysis with Thc_Cut1. Although both enzymes led to similar concentrations of released products upon hydrolysis of PET and PHBV, Thc_Cut1_koST was found to be significantly more active on PBS than the native Thc_Cut1. Hydrolysis of PBS films by Thc_Cut1 and Thc_Cut1_koST was followed by weight loss and scanning electron microscopy (SEM). Within 96 h of hydrolysis up to 92 and 41% of weight loss were detected with Thc_Cut1_koST and Thc_Cut1, respectively. Furthermore, SEM characterization of PBS films clearly showed that enzyme tretment resulted in morphological changes of the film surface. PMID:28596765

  10. Gas gangrene of the abdominal wall due to late-onset enteric fistula after polyester mesh repair of an incisional hernia.

    PubMed

    Moussi, A; Daldoul, S; Bourguiba, B; Othmani, D; Zaouche, A

    2012-04-01

    The occurrence of enteric fistulae after wall repair using a prosthetic mesh is a serious but, fortunately, rare complication. We report the case of a 66-year-old diabetic man who presented with gas gangrene of the abdominal wall due to an intra-abdominal abscess caused by intestinal erosion six years after an incisional hernia repair using a polyester mesh. The aim of this case report is to illustrate the seriousness of enteric fistula after parietal repair using a synthetic material.

  11. Physical Properties of Polyester Fabrics Treated with Nano, Micro and Macro Emulsion Silicones

    NASA Astrophysics Data System (ADS)

    Parvinzadeh, M.; Hajiraissi, R.

    2007-08-01

    The processing of textile to achieve a particular handle is one of the most important aspects of finishing technology. Fabrics softeners are liquid composition added to washing machines during the rinse cycle to make clothes feel better to the touch. The first fabric softeners were developed by the textile industry during the early twentieth century. In this research polyester fabrics were treated with nano, micro and macro emulsion silicone softeners. Some of the physical properties of the treated fabric samples are discussed. The drapeability of treated samples was improved after treatment with nano silicone softeners. The colorimetric measurement of softener-treated fabrics is evaluated with a reflectance spectrophotometer. Moisture regain of treated samples is increased due to coating of silicone softeners. There is some increase in the weight of softener-treated samples. Samples treated with nano emulsion silicones gave better results compared to micro- and macro-emulsion treated ones.

  12. Inclusion by Design: Engineering Inclusive Practices in Secondary Schools

    ERIC Educational Resources Information Center

    Dukes, Charles; Lamar-Dukes, Pamela

    2009-01-01

    In order to help teachers understand the importance of intentional design for inclusive education, this article describes the design process an engineer might use when designing a new project. If teachers learn to think like engineers, it is possible for them to design inclusive education. This conceptual design can then be combined with…

  13. The crack-inclusion interaction problem

    NASA Technical Reports Server (NTRS)

    Liu, X.-H.; Erdogan, F.

    1986-01-01

    The general plane elastostatic problem of interaction between a crack and an inclusion is considered. The Green's functions for a pair of dislocations and a pair of concentrated body forces are used to generate the crack and the inclusion. Integral equations are obtained for a line crack and an elastic line inclusion having an arbitrary relative orientation and size. The nature of stress singularity around the end points of rigid and elastic inclusions is described and three special cases of this intersection problem are studied. The problem is solved for an arbitrary uniform stress state away from the crack-inclusion region. The nonintersecting crack-inclusion problem is considered for various relative size, orientation, and stiffness parameters, and the stress intensity factors at the ends of the inclusion and the crack are calculated. For the crack-inclusion intersection case, special stress intensity factors are defined and are calculated for various values of the parameters defining the relative size and orientation of the crack and the inclusion and the stiffness of the inclusion.

  14. The crack-inclusion interaction problem

    NASA Technical Reports Server (NTRS)

    Xue-Hui, L.; Erdogan, F.

    1984-01-01

    The general plane elastostatic problem of interaction between a crack and an inclusion is considered. The Green's functions for a pair of dislocations and a pair of concentrated body forces are used to generate the crack and the inclusion. Integral equations are obtained for a line crack and an elastic line inclusion having an arbitrary relative orientation and size. The nature of stress singularity around the end points of rigid and elastic inclusions is described and three special cases of this intersection problem are studied. The problem is solved for an arbitrary uniform stress state away from the crack-inclusion region. The nonintersecting crack-inclusion problem is considered for various relative size, orientation, and stiffness parameters, and the stress intensity factors at the ends of the inclusion and the crack are calculated. For the crack-inclusion intersection case, special stress intensity factors are defined and are calculated for various values of the parameters defining the relative size and orientation of the crack and the inclusion and the stiffness of the inclusion.

  15. Does negative-pressure wound therapy influence subjacent bacterial growth? A systematic review.

    PubMed

    Glass, Graeme E; Murphy, George R F; Nanchahal, Jagdeep

    2017-08-01

    Negative-pressure wound therapy is a ubiquitous wound management resource. The influence of NPWT on the bacterial bioburden of the subjacent wound remains unclear. We sought to examine the evidence. MEDLINE, Embase, PubMed, the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles quantitatively evaluating bacterial load under NPWT. Twenty-four studies met the inclusion criteria including 4 randomised controlled trials, 8 clinical series and 12 experimental studies. Twenty studies evaluated conventional NPWT, while 4 evaluated infiltration-based NPWT. While 8 studies using conventional NPWT failed to demonstrate an observable effect on bacterial load, 7 studies reported that NPWT was inherently bacteriostatic and 5 others reported species selectivity with suppression of non-fermentative gram-negative bacilli (NFGNB), including Pseudomonas spp. Simultaneously, there was some evidence of enhanced proliferation of gram-positive cocci where the niche was cleared of NFGNB. Two of the 4 studies using infiltration-based NPWT also reported selectively impaired proliferation of Pseudomonas spp. The assumption that NPWT suppresses bacterial proliferation is oversimplified. There is evidence that NPWT exhibits species selectivity, suppressing the proliferation of NFGNB. However, this may depopulate the niche for exploitation by gram-positive cocci. This, in turn, has implications for the use of NPWT where highly virulent strains of gram-positive cocci have been isolated and the duration of NPWT therapy and frequency of dressing changes. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. [Bacterial meningitis].

    PubMed

    Brouwer, M C; van de Beek, D

    2012-05-01

    Bacterial meningitis is a severe disease which affects 35.000 Europeans each year and has a mortality rate of about 20%. During the past 25 years the epidemiology of bacterial meningitis has changed significantly due to the implementation of vaccination against Haemophilus influenzae, Neisseria meningtidis group C and Streptococcus pneumoniae. Due to these vaccines, meningitis is now predominantly a disease occurring in adults, caused especially by Streptococcus pneumoniae, while it was formerly a child disease which was largely caused by Haemophilus influenzae. Bacterial meningitis is often difficult to recognize since the classical presentation with neck stiffness, reduced awareness and fever occurs in less than half of the patients. The only way to diagnose or exclude bacterial meningitis is by performing low-threshold cerebrospinal fluid examination with a suspicion of bacterial meningitis. The treatment consists of the prescription of antibiotics and dexamethasone.

  17. [Clinical outcome and prognosis of neonatal bacterial meningitis].

    PubMed

    Ben Hamouda, H; Ben Haj Khalifa, A; Hamza, M A; Ayadi, A; Soua, H; Khedher, M; Sfar, M T

    2013-09-01

    To study the epidemiological, clinical, and bacteriological aspects as well as the outcome of neonatal bacterial meningitis and analyze the factors of poor prognosis of this condition. We report a retrospective analysis of 44 cases of neonatal bacterial meningitis hospitalized in the pediatric unit of Tahar Sfar Hospital in Mahdia, Tunisia, between January 1996 and December 2010. Inclusion criteria were infants less than 29 days of age who were hospitalized for bacterial meningitis diagnosed on either the presence of bacteria in cerebrospinal fluid or with more than 50 cells/mm(3), predominance of neutrophils, and the protein level greater than 1.2g/l. Clinical data were obtained through the analysis of patient files. Statistical analysis was based on the Chi(2) test, and P-values less than 0.05 were considered statistically significant. The incidence of neonatal bacterial meningitis was 0.49 per 1000 live births. The patients were premature in 20.4 % and low birth weight in 13.6 % of cases. The clinical presentation was not specific for most cases. The main signs at admission were hyperthermia (43.2 %), refusal to nurse (20.4 %), seizures (18.2 %), and respiratory distress (13.6 %). The cerebrospinal fluid culture was positive in 36.4 % of cases. The group B streptococcus was the most frequently isolated (62.5 %) followed by Escherichia coli (12.5 %). The association of cefotaxime-ampicillin-gentamicin was used as the first treatment in all cases. Ofloxacin was associated with initial antibiotic therapy during the first 5 days in 20.4 % of cases. The mortality rate was 15.9 % and the rate of neurological sequelae in survivors was 21.6 %. Prematurity, low birth weight, shock, respiratory distress, and pleocytosis of less than 500 cells/mm(3) were the main factors of a poor prognosis. The addition of ofloxacin to the initial antibiotic therapy was associated with a decreased rate of neurological sequelae in survivors (11 % vs. 25 %, P=0.042). This study emphasizes

  18. Toughening epoxy acrylate with polyurethane acrylates and hyper-branched polyester in three dimensional printing

    NASA Astrophysics Data System (ADS)

    Fang, Chao; Li, Ning; Liu, Yang; Lu, Gang

    2018-05-01

    In order to improve the toughness of epoxy acrylate (EA) in three dimensional printing (3D-printing), bifunctional polyurethane acrylate (PUA) and trifunctional PUA were firstly blended with EA. The multi-indicators orthogonal experiment, designed with the indicators of tensile strength, elongation at break and impact strength, was used to find out the optimal formulation. Then, hyper-branched polyesters (HBPs) was added to improve the toughness of the photocurable system. The microstructures of the cured specimens were characterized by optical microscopy and scanning electron microscopy. By analyzing their mechanical properties and microstructures, it was revealed that the best addition amounts of HBP are 10 wt%. Results indicated that their toughness improved a lot comparing with pure EA. The changes of mechanical properties were characterized by DMA. The addition of HBP could cause a loss in stiffness, elasticity modulus and thermostability.

  19. Hemp-Fiber-Reinforced Unsaturated Polyester Composites: Optimization of Processing and Improvement of Interfacial Adhesion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Qui, Renhui; Ren, Xiaofeng; Fifield, Leonard S.

    2011-02-25

    The processing variables for making hemp-fiber-reinforced unsaturated polyester (UPE) composites were optimized through orthogonal experiments. It was found that the usage of initiator, methyl ethyl ketone peroxide, had the most significant effect on the tensile strength of the composites. The treatment of hemp fibers with a combination of 1, 6-diisocyanatohexane (DIH) and 2-hydroxylethyl acrylate (HEA) significantly increased tensile strength, flexural modulus of rupture and flexural modulus of elasticity, and water resistance of the resulting hemp-UPE composites. FTIR spectra revealed that DIH and HEA were covalently bonded to hemp fibers. Scanning electronic microscopy graphs of the fractured hemp-UPE composites demonstrated thatmore » treatment of hemp fibers with a combination of DIH and HEA greatly improved the interfacial adhesion between hemp fibers and UPE. The mechanism of improving the interfacial adhesion is proposed.« less

  20. Modeling the effects of free-living marine bacterial community composition on heterotrophic remineralization rates and biogeochemical carbon cycling

    NASA Astrophysics Data System (ADS)

    Teel, E.; Liu, X.; Cram, J. A.; Sachdeva, R.; Fuhrman, J. A.; Levine, N. M.

    2016-12-01

    Global oceanic ecosystem models either disregard fluctuations in heterotrophic bacterial remineralization or vary remineralization as a simple function of temperature, available carbon, and nutrient limitation. Most of these models were developed before molecular techniques allowed for the description of microbial community composition and functional diversity. Here we investigate the impact of a dynamic heterotrophic community and variable remineralization rates on biogeochemical cycling. Specifically, we integrated variable microbial remineralization into an ecosystem model by utilizing molecular community composition data, association network analysis, and biogeochemical rate data from the San Pedro Ocean Time-series (SPOT) station. Fluctuations in free-living bacterial community function and composition were examined using monthly environmental and biological data collected at SPOT between 2000 and 2011. On average, the bacterial community showed predictable seasonal changes in community composition and peaked in abundance in the spring with a one-month lag from peak chlorophyll concentrations. Bacterial growth efficiency (BGE), estimated from bacterial production, was found to vary widely at the site (5% to 40%). In a multivariate analysis, 47.6% of BGE variability was predicted using primary production, bacterial community composition, and temperature. A classic Nutrient-Phytoplankton-Zooplankton-Detritus model was expanded to include a heterotroph module that captured the observed relationships at the SPOT site. Results show that the inclusion of dynamic bacterial remineralization into larger oceanic ecosystem models can significantly impact microzooplankton grazing, the duration of surface phytoplankton blooms, and picophytoplankton primary production rates.

  1. Biodegradation of polyester polyurethane by Aspergillus tubingensis.

    PubMed

    Khan, Sehroon; Nadir, Sadia; Shah, Zia Ullah; Shah, Aamer Ali; Karunarathna, Samantha C; Xu, Jianchu; Khan, Afsar; Munir, Shahzad; Hasan, Fariha

    2017-06-01

    The xenobiotic nature and lack of degradability of polymeric materials has resulted in vast levels of environmental pollution and numerous health hazards. Different strategies have been developed and still more research is being in progress to reduce the impact of these polymeric materials. This work aimed to isolate and characterize polyester polyurethane (PU) degrading fungi from the soil of a general city waste disposal site in Islamabad, Pakistan. A novel PU degrading fungus was isolated from soil and identified as Aspergillus tubingensis on the basis of colony morphology, macro- and micro-morphology, molecular and phylogenetic analyses. The PU degrading ability of the fungus was tested in three different ways in the presence of 2% glucose: (a) on SDA agar plate, (b) in liquid MSM, and (c) after burial in soil. Our results indicated that this strain of A. tubingensis was capable of degrading PU. Using scanning electron microscopy (SEM), we were able to visually confirm that the mycelium of A. tubingensis colonized the PU material, causing surface degradation and scarring. The formation or breakage of chemical bonds during the biodegradation process of PU was confirmed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. The biodegradation of PU was higher when plate culture method was employed, followed by the liquid culture method and soil burial technique. Notably, after two months in liquid medium, the PU film was totally degraded into smaller pieces. Based on a comprehensive literature search, it can be stated that this is the first report showing A. tubingensis capable of degrading PU. This work provides insight into the role of A. tubingensis towards solving the dilemma of PU wastes through biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The Value of Inclusion

    ERIC Educational Resources Information Center

    Felder, Franziska

    2018-01-01

    In recent years inclusion has become one of the most dominant values and objectives in education. However, there is still considerable disagreement concerning the theoretical concept of inclusion and its normative implications. This article suggests an understanding of inclusion that first differentiates analytically between societal and communal…

  3. Poly(Neopentyl Glycol Furanoate): A Member of the Furan-Based Polyester Family with Smart Barrier Performances for Sustainable Food Packaging Applications

    PubMed Central

    Munari, Andrea

    2017-01-01

    In the last decade, there has been an increased interest from the food packaging industry toward the development and application of bioplastics, to contribute to the sustainable economy and to reduce the huge environmental problem afflicting the planet. In the present work, we focus on a new furan-based polyester, poly(neopentyl glycol 2,5-furanoate) (PNF) to be used for sustainable food packaging applications. The aromatic polyester was successfully synthesized with high molecular weight, through a solvent-free process, starting directly from 2,5-furandicarboxylic acid. PNF was revealed to be a material with good thermal stability, characterized by a higher Tg and Tm and a lower RAF fraction compared to poly(propylene 2,5-furanoate) (PPF), ascribable to the two methyl side groups present in PNF glycol-sub-unit. PNF’s mechanical characteristics, i.e., very high elastic modulus and brittle fracture, were found to be similar to those of PPF and PEF. Barrier properties to different gases, temperatures and relative humidity were evaluated. From the results obtained, PNF was showed to be a material with very smart barrier performances, significantly superior with respect to PEF’s ones. Lastly, PNF’s permeability behavior did not appreciably change after contact with food simulants, whereas it got worse with increasing RH, due to the polar nature of furan ring. PMID:28869555

  4. Poly(Neopentyl Glycol Furanoate): A Member of the Furan-Based Polyester Family with Smart Barrier Performances for Sustainable Food Packaging Applications.

    PubMed

    Genovese, Laura; Lotti, Nadia; Siracusa, Valentina; Munari, Andrea

    2017-09-04

    In the last decade, there has been an increased interest from the food packaging industry toward the development and application of bioplastics, to contribute to the sustainable economy and to reduce the huge environmental problem afflicting the planet. In the present work, we focus on a new furan-based polyester, poly(neopentyl glycol 2,5-furanoate) (PNF) to be used for sustainable food packaging applications. The aromatic polyester was successfully synthesized with high molecular weight, through a solvent-free process, starting directly from 2,5-furandicarboxylic acid. PNF was revealed to be a material with good thermal stability, characterized by a higher T g and T m and a lower RAF fraction compared to poly(propylene 2,5-furanoate) (PPF), ascribable to the two methyl side groups present in PNF glycol-sub-unit. PNF's mechanical characteristics, i.e., very high elastic modulus and brittle fracture, were found to be similar to those of PPF and PEF. Barrier properties to different gases, temperatures and relative humidity were evaluated. From the results obtained, PNF was showed to be a material with very smart barrier performances, significantly superior with respect to PEF's ones. Lastly, PNF's permeability behavior did not appreciably change after contact with food simulants, whereas it got worse with increasing RH, due to the polar nature of furan ring.

  5. Hybrid fixation with sublaminar polyester bands in the treatment of neuromuscular scoliosis: a comparative analysis.

    PubMed

    Albert, Michael C; LaFleur, Brett C

    2015-03-01

    Segmental spinal instrumentation with Luque wire fixation has been the standard treatment of neuromuscular scoliosis for >30 years. More recently, pedicle screw constructs have become the most widely utilized method of posterior spinal fixation; however, they are associated with complications such as implant malposition. We report the use of polyester bands and clamps utilized with pedicle screws in a hybrid fixation construct in the treatment of neuromuscular scoliosis. A retrospective review was conducted of 115 pediatric spinal deformity cases between 2008 and 2010 at a single center performed by a single surgeon. Intraoperative and postoperative complications were recorded. Radiographs were reviewed preoperatively and at the latest follow-up. A systematic review of the literature was conducted. Data from case series reporting outcomes of sublaminar wires and all-pedicle screw constructs in the treatment of neuromuscular scoliosis were compared with outcomes of the present study. Twenty-nine patients with neuromuscular scoliosis who underwent segmental spinal instrumentation with a hybrid construct including sublaminar bands and pedicle screws were included. There was an average follow-up of 29 months (range, 12 to 40 mo). The average postoperative correction of coronal balance was 69% (range, 24 to 71 degrees). Sagittal balance was corrected to within 2 cm of the C7 plumbline in 97% of patients. The loss of coronal and sagittal correction at latest follow-up was 0% and 2%, respectively. There were 2 intraoperative clamp failures of the 398 implants (0.5%). There were 2 major (6.9%) and 7 minor (24%) complications in 7 patients (24% overall). These results compared favorably to previous case series of sublaminar wire and all-pedicle screw fixation techniques. The polyester band technique is an excellent adjunct in the correction of spinal deformity in patients with neuromuscular scoliosis. Sublaminar bands utilized in a hybrid construct appear to be safe, can

  6. Modulatory effects of condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid on the bovine rumen bacterial community in vitro.

    PubMed

    Saminathan, Mookiah; Sieo, Chin Chin; Gan, Han Ming; Ravi, Sharanya; Venkatachalam, Karthikkumar; Abdullah, Norhani; Wong, Clemente Michael Vui Ling; Ho, Yin Wan

    2016-10-01

    Condensed tannin (CT) fractions of different molecular weights (MWs) may affect rumen microbial metabolism by altering bacterial diversity. In this study the effects of unfractionated CTs (F0) and five CT fractions (F1-F5) of different MWs (F1, 1265.8 Da; F2, 1028.6 Da; F3, 652.2 Da; F4, 562.2 Da; F5, 469.6 Da) from Leucaena leucocephala hybrid-Rendang (LLR) on the structure and diversity of the rumen bacterial community were investigated in vitro. Real-time polymerase chain reaction assay showed that the total bacterial population was not significantly (P > 0.05) different among the dietary treatments. Inclusion of higher-MW CT fractions F1 and F2 significantly (P < 0.05) increased the Fibrobacter succinogenes population compared with F0 and CT fractions F3-F5. Although inclusion of F0 and CT fractions (F1-F5) significantly (P < 0.05) decreased the Ruminococcus flavefaciens population, there was no effect on the Ruminococcus albus population when compared with the control (without CTs). High-throughput sequencing of the V3 region of 16S rRNA showed that the relative abundance of genera Prevotella and unclassified Clostridiales was significantly (P < 0.05) decreased, corresponding with increasing MW of CT fractions, whereas cellulolytic bacteria of the genus Fibrobacter were significantly (P < 0.05) increased. Inclusion of higher-MW CT fractions F1 and/or F2 decreased the relative abundance of minor genera such as Ruminococcus, Streptococcus, Clostridium XIVa and Anaeroplasma but increased the relative abundance of Acinetobacter, Treponema, Selenomonas, Succiniclasticum and unclassified Spirochaetales compared with the control and lower-MW CT fractions. This study indicates that CT fractions of different MWs may play an important role in altering the structure and diversity of the rumen bacterial community in vitro, and the impact was more pronounced for CT fractions with higher MW. © 2016 Society of Chemical Industry. © 2016 Society of

  7. The impact of bacterial and viral co‐infection in severe influenza

    PubMed Central

    Blyth, Christopher C.; Webb, Steve A. R.; Kok, Jen; Dwyer, Dominic E.; van Hal, Sebastiaan J.; Foo, Hong; Ginn, Andrew N.; Kesson, Alison M.; Seppelt, Ian; Iredell, Jonathan R.

    2013-01-01

    Please cite this paper as: Blyth et al. (2013) The impact of bacterial and viral co‐infection in severe influenza. Influenza and Other Respiratory Viruses 7(2) 168–176. Background  Many questions remain concerning the burden, risk factors and impact of bacterial and viral co‐infection in patients with pandemic influenza admitted to the intensive care unit (ICU). Objectives  To examine the burden, risk factors and impact of bacterial and viral co‐infection in Australian patients with severe influenza. Patients/Methods  A cohort study conducted in 14 ICUs was performed. Patients with proven influenza A during the 2009 influenza season were eligible for inclusion. Demographics, risk factors, clinical data, microbiological data, complications and outcomes were collected. Polymerase chain reaction for additional bacterial and viral respiratory pathogens was performed on stored respiratory samples. Results  Co‐infection was identified in 23·3–26·9% of patients with severe influenza A infection: viral co‐infection, 3·2–3·4% and bacterial co‐infection, 20·5–24·7%. Staphylococcus aureus was the most frequent bacterial co‐infection followed by Streptococcus pneumoniae and Haemophilus influenzae. Patients with co‐infection were younger [mean difference in age = 8·46 years (95% CI: 0·18–16·74 years)], less likely to have significant co‐morbidities (32·0% versus 66·2%, P = 0·004) and less frequently obese [mean difference in body mass index = 6·86 (95% CI: 1·77–11·96)] compared to those without co‐infection. Conclusions  Bacterial or viral co‐infection complicated one in four patients admitted to ICU with severe influenza A infection. Despite the co‐infected patients being younger and with fewer co‐morbidities, no significant difference in outcomes was observed. It is likely that co‐infection contributed to a need for ICU admission in those without other risk factors for severe influenza disease

  8. Effect of alkaline treatment on mechanical properties of kenaf fiber reinforced polyester composites

    NASA Astrophysics Data System (ADS)

    Reddy, Bijjam Ramgopal; Dhoria, Sneha H.

    2018-04-01

    This paper focuses on the study of the effect of chemical treatment on mechanical properties such as tensile, flexural and impact properties of kenaf fiber reinforced polyester composites. Adhesion between the fiber and polymer is one of factors affecting the mechanical properties of composites. In order to increase the adhesion, the fibers are chemically treated with 5% of sodium hydroxide (NaOH) solution. The composite specimens are prepared in both untreated and treated forms of kenaf fibers with five levels of fiber volume fractions. The specimens are prepared according to ASTM standards. Mechanical tests such as tensile, flexural and impact are conducted to determine ultimate tensile strength, bending strength and impact strength of composites. The effect of change in volume fraction on the mechanical properties of the composites is studied for both untreated (raw) and chemically treated kenaf fibers. It has been found that the composites made of chemically treated fibers have good mechanical properties compared to untreated fibers.

  9. Inclusion as Professional Development

    ERIC Educational Resources Information Center

    Stanovich, Paula J.; Jordan, Anne

    2004-01-01

    The inclusion of students with disabilities in general education classrooms has become the preferred model of service delivery in many educational jurisdictions. The benefits of an inclusive model for students are becoming clear as the research evidence begins to accumulate. However, the authors argue, inclusion may well offer benefits for…

  10. Inclusion in Middle Tennessee

    ERIC Educational Resources Information Center

    Salter, Derrick; Ashley, Mandi; Hayes, Brandalyn

    2013-01-01

    The overall purpose of this study was to provide school districts within Tennessee with more research about how weekly hours of inclusion impact student achievement. Specifically, researchers examined which models of inclusion were in use in two school districts in Tennessee, administrators' and teachers' perceptions of inclusion, and whether or…

  11. Inclusive Education in Bangladesh

    ERIC Educational Resources Information Center

    Ahsan, Mohammad Tariq; Burnip, Lindsay

    2007-01-01

    This article reports on inclusive education in Bangladesh for children with special needs. Bangladesh is not behind other developed countries in enacting laws and declarations in favour of inclusive education, but a lack of resources is the main barrier in implementing inclusive education. Special education and integrated education models exist in…

  12. Footstep towards Inclusive Education

    ERIC Educational Resources Information Center

    Abbas, Faiza; Zafar, Aneeka; Naz, Tayyaba

    2016-01-01

    Inclusive education is a rising trend in the world. The first step towards inclusive education is providing the awareness to the general education teachers. This study focused to investigate the general education teachers of primary and secondary level awareness about the special education and inclusive education. This study is descriptive method…

  13. More Policies, Greater Inclusion? Exploring the Contradictions of New Labour Inclusive Education Policy

    ERIC Educational Resources Information Center

    Roulstone, Alan; Prideaux, Simon

    2008-01-01

    The era of New Labour government has witnessed unprecedented growth in inclusive education policies. There is, however, limited evidence that policies have increased disabled children's inclusion. This article explores reasons for this contradiction. Drawing on sociological insights, it is argued that New Labour policies on inclusive education…

  14. Synthesis of Unsaturated Polyester Resins from Various Bio-Derived Platform Molecules.

    PubMed

    Farmer, Thomas J; Castle, Rachael L; Clark, James H; Macquarrie, Duncan J

    2015-07-02

    Utilisation of bio-derived platform molecules in polymer synthesis has advantages which are, broadly, twofold; to digress from crude oil dependence of the polymer industry and secondly to reduce the environmental impact of the polymer synthesis through the inherent functionality of the bio-derived platform molecules. Bulk polymerisation of bio-derived unsaturated di-acids has been employed to produce unsaturated polyester (UPEs) which have been analysed by GPC, TGA, DSC and NMR spectroscopy, advancing on the analysis previously reported. UPEs from the diesters of itaconic, succinic, and fumaric acids were successfully synthesised with various diols and polyols to afford resins of MN 480-477,000 and Tg of -30.1 to -16.6 °C with solubilities differing based on starting monomers. This range of properties allows for many applications and importantly due to the surviving Michael acceptor moieties, solubility and cross-linking can be specifically tailored, post polymerisation, to the desired function. An improved synthesis of itaconate and succinate co-polymers, via the initial formation of an itaconate bis-diol, is also demonstrated for the first time, resulting in significantly improved itaconate incorporation.

  15. Linguistic Diversity and Social Inclusion

    ERIC Educational Resources Information Center

    Piller, Ingrid; Takahashi, Kimie

    2011-01-01

    This introduction provides the framework for the special issue by describing the social inclusion agenda of neoliberal market democracies. While the social inclusion agenda has been widely adopted, social inclusion policies are often blind to the ways in which language proficiency and language ideologies mediate social inclusion in linguistically…

  16. Inclusion in the East: Chinese Students' Attitudes towards Inclusive Education

    ERIC Educational Resources Information Center

    Malinen, Olli-Pekka; Savolainen, Hannu

    2008-01-01

    A sample of 523 Chinese university students was given a questionnaire on their attitudes towards the inclusion of children with disabilities into regular classrooms. Factor analysis, analysis of variance, t-test and correlations were used to assess the respondents' general attitude towards inclusion, the factor structure of the attitudes, the…

  17. Homogenisation of sulphide inclusions within diamonds: A new approach to diamond inclusion geochemistry

    NASA Astrophysics Data System (ADS)

    McDonald, Iain; Hughes, Hannah S. R.; Butler, Ian B.; Harris, Jeffrey W.; Muir, Duncan

    2017-11-01

    Base metal sulphide (BMS) inclusions in diamonds provide a unique insight into the chalcophile and highly siderophile element composition of the mantle. Entombed within their diamond hosts, these provide a more robust (closed system) sample, from which to determine the trace element, Re-Os and S-isotopic compositions of the mantle than mantle xenoliths or orogenic peridotites, as they are shielded from alteration during ascent to the Earth's crust and subsequent surface weathering. However, at temperatures below 1100 °C some BMS inclusions undergo subsolidus re-equilibration from an original monosulphide solid solution (Mss) and this causes fractionation of the major and trace elements within the inclusions. Thus to study the subjects noted above, current techniques require the entire BMS inclusion to be extracted for analyses. Unfortunately, 'flaking' of inclusions during break-out is a frequent occurrence and hence the risk of accidentally under-sampling a portion of the BMS inclusion is inherent in current practices. This loss may have significant implications for Re-Os isotope analyses where incomplete sampling of a Re-rich phase, such as chalcopyrite that typically occurs at the outer margins of BMS inclusions, may induce significant bias in the Re-Os and 187Os/188Os measurements and resulting model and isochron ages. We have developed a method for the homogenisation of BMS inclusions in diamond prior to their break-out from the host stone. Diamonds are heated to 1100 °C and then quenched to chemically homogenise any sulphide inclusions for both major and trace elements. Using X-ray Computed Microtomography (μCT) we determine the shape and spatial setting of multiple inclusions within a host stone and crucially show that the volume of a BMS inclusion is the same both before and after homogenisation. We show that the homogenisation process significantly reduces the inherent variability of in situ analysis when compared with unhomogenised BMS, thereby

  18. Measuring the Quality of Inclusive Practices: Findings from the Inclusive Classroom Profile Pilot

    ERIC Educational Resources Information Center

    Soukakou, Elena P.; Winton, Pam J.; West, Tracey A.; Sideris, John H.; Rucker, Lia M.

    2014-01-01

    The purpose of this study was to test the reliability and validity of the Inclusive Classroom Profile (ICP), an observation measure designed to assess the quality of classroom practices in inclusive preschool programs. The measure was field tested in 51 inclusive classrooms. Results confirmed and extended previous research findings, providing…

  19. Limitations of inclusive fitness.

    PubMed

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.

  20. Significant sequelae after bacterial meningitis in Niger: a cohort study.

    PubMed

    Jusot, Jean-François; Tohon, Zilahatou; Yazi, Abdoul Aziz; Collard, Jean-Marc

    2013-05-21

    Beside high mortality, acute bacterial meningitis may lead to a high frequency of neuropsychological sequelae. The Sahelian countries belonging to the meningitis belt experience approximately 50% of the meningitis cases occurring in the world. Studies in Africa have shown that N. meningitidis could cause hearing loss in up to 30% of the cases, exceeding sometimes measles. The situation is similar in Niger which experiences yearly meningitis epidemics and where rehabilitation wards are rare and hearing aids remain unaffordable. The aim of this study was to estimate the frequency of neuropsychological sequelae after acute bacterial meningitis in four of the eight regions of Niger. Subjects exposed to acute bacterial meningitis were enrolled into a cohort with non exposed subjects matched on age and gender. Consenting subjects were interviewed during inclusion and at a control visit two months later. If clinical symptoms or psychological troubles persisted at both visits among the exposed subjects with a frequency significantly greater than that observed among the non exposed subjects, a sequelae was retained. The comparison of the frequency of sequelae between non exposed and exposed subjects to bacterial meningitis was also calculated using the Fisher exact test. Three persisting functional symptoms were registered: headaches, asthenia, and vertigo among 31.3, 36.9, and 22.4% respectively of the exposed subjects. A significant motor impairment was retrieved among 12.3% of the exposed versus 1.6% of the non exposed subjects. Hearing loss significantly disabled 31.3% of the exposed subjects and 10.4% exhibited a serious deafness. This study carried out in Niger confirms two serious neurological sequelae occurring at high frequencies after bacterial meningitis: severe and profound hearing loss and motor impairment. Cochlear implantation and hearing aids are too expensive for populations living in developing countries. Neurological sequelae occurring after meningitis

  1. Student Teachers' Attitudes and Beliefs about Inclusion and Inclusive Practice

    ERIC Educational Resources Information Center

    Beacham, Nigel; Rouse, Martyn

    2012-01-01

    The beliefs and attitudes of teachers are an important element in the development of inclusive education and its associated practices. Teacher education is seen as crucial in helping to develop positive attitudes and beliefs that are thought to promote inclusion, although attempts to reform teacher education in order to address issues of inclusion…

  2. Antibiotics for bacterial vaginosis or Trichomonas vaginalis in pregnancy: a systematic review.

    PubMed

    Okun, Nan; Gronau, Karen A; Hannah, Mary E

    2005-04-01

    To determine whether antibiotic treatment for bacterial vaginosis or Trichomonas vaginalis during pregnancy decreases the risk of preterm birth and associated adverse outcomes. Pre-MEDLINE and MEDLINE (1966-2003), EMBASE (1980-2003), and the Cochrane Library were searched using the keywords "bacterial vaginosis", "Trichomonas", "Trichomonas vaginalis", "Trichomonas vaginitis", "Trichomonas infections", "pregnancy", "pregnant", "antibiotics", and "antibiotic prophylaxis". The search produced 1,888 titles, of which 1,256 abstracts were reviewed further. Of these, 1,217 were ineligible. Inclusion criteria were the following: randomized controlled trials in which antibiotics were compared with no antibiotic or placebo, for women in the second or third trimester of pregnancy with symptomatic or asymptomatic bacterial vaginosis or Trichomonas vaginalis, intact membranes, and not in labor. Exclusion criteria were as follows: published in a language other than English, dropout rate of more than 20% of women in either group, and lack of usable outcomes. Of the 39 papers reviewed in detail, 14 studies were included in the meta-analysis. One of the authors reviewed titles obtained from the searches, and 2 reviewers independently reviewed the abstracts, excluded those that were ineligible, identified eligible papers, and abstracted the data. For women with bacterial vaginosis, antibiotics reduced the risk of persistent infection but did not reduce the risk of preterm birth or the incidence of associated adverse outcomes for the general population or for any subgroup analyzed. For women with Trichomonas vaginalis, metronidazole reduced the risk of persistent infection but increased the incidence of preterm birth. Contrary to the conclusions of 3 recent systematic reviews, we found no evidence to support the use of antibiotic treatment for bacterial vaginosis or Trichomonas vaginalis in pregnancy to reduce the risk of preterm birth or its associated morbidities in low- or high

  3. K+ Block Is the Mechanism of Functional Asymmetry in Bacterial Nav Channels

    PubMed Central

    Ngo, Van; Wang, Yibo; Haas, Stephan; Noskov, Sergei Y.; Farley, Robert A.

    2016-01-01

    Crystal structures of several bacterial Nav channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Nav channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial NavAb channel. This approach provided new insight into the mechanism of selective ion permeation in bacterial Nav channels. The non-equilibrium simulations indicate that two or three extracellular K+ ions can block the entrance to the selectivity filter of NavAb in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be ‘locked’ in place by modest applied forces. In contrast to K+, three Na+ ions move favorably through the selectivity filter together as a unit in a loose “knock-on” mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na+ ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K+ block is equivalent to large applied potentials experimentally measured for two bacterial Nav channels to induce inward currents of K+ ions. These results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed free-energy landscapes

  4. CYP86B1 Is Required for Very Long Chain ω-Hydroxyacid and α,ω-Dicarboxylic Acid Synthesis in Root and Seed Suberin Polyester1[W][OA

    PubMed Central

    Compagnon, Vincent; Diehl, Patrik; Benveniste, Irène; Meyer, Denise; Schaller, Hubert; Schreiber, Lukas; Franke, Rochus; Pinot, Franck

    2009-01-01

    Suberin composition of various plants including Arabidopsis (Arabidopsis thaliana) has shown the presence of very long chain fatty acid derivatives C20 in addition to the C16 and C18 series. Phylogenetic studies and plant genome mining have led to the identification of putative aliphatic hydroxylases belonging to the CYP86B subfamily of cytochrome P450 monooxygenases. In Arabidopsis, this subfamily is represented by CYP86B1 and CYP86B2, which share about 45% identity with CYP86A1, a fatty acid ω-hydroxylase implicated in root suberin monomer synthesis. Here, we show that CYP86B1 is located to the endoplasmic reticulum and is highly expressed in roots. Indeed, CYP86B1 promoter-driven β-glucuronidase expression indicated strong reporter activities at known sites of suberin production such as the endodermis. These observations, together with the fact that proteins of the CYP86B type are widespread among plant species, suggested a role of CYP86B1 in suberin biogenesis. To investigate the involvement of CYP86B1 in suberin biogenesis, we characterized an allelic series of cyp86B1 mutants of which two strong alleles were knockouts and two weak ones were RNA interference-silenced lines. These root aliphatic plant hydroxylase lines had a root and a seed coat aliphatic polyester composition in which C22- and C24-hydroxyacids and α,ω-dicarboxylic acids were strongly reduced. However, these changes did not affect seed coat permeability and ion content in leaves. The presumed precursors, C22 and C24 fatty acids, accumulated in the suberin polyester. These results demonstrate that CYP86B1 is a very long chain fatty acid hydroxylase specifically involved in polyester monomer biosynthesis during the course of plant development. PMID:19525321

  5. A comparison in vivo dacron wool (Swank) and polyester mesh (Pall) micropore blood transfusion filters in the prevention of pulmonary microembolism associated with massive transfusion.

    PubMed Central

    Barrett, J; Dhurandhar, H N; Miller, E; Litwin, M S

    1975-01-01

    Experiments were performed to compare the effectiveness in vivo of the two most widely used micropore blood transfusion filters in preventing detrimental physiologic changes associated with transfusion of microaggregate-containing blood. Exchange transfusion with stored blood having an elevated screen filtration pressure (SFP) through polyester mesh (Pall) filters (Group PM) was followed by decreases in arterial blood pH and O2 consumption, increases in arterial blood pyruvate and lactate concentrations, and a decrease in pulmonary DO2. The lungs of 5 of 6 animals revealed emboli far out in the pulmonary microcirculation. These changes did not occur in animals transfused through dacron wool (Swank) filters (Group DW). Even though an increase after transfusion in pulmonary Qs/Qt in Group PM did not achieve statistical significance when compared to pretransfusion Qs/Qt, it was significantly higher than that in animals in Group DW. Both filters removed considerable quantities of microaggregates; however, the polyester mesh (Pall) filters permitted passage of small microaggregates and development of ditrimental physiologic changes. Dacron wool (Swank) filters completely removed measurable microaggregates and detrimental changes did not occur. Images Fig. 1. Fig. 2. Fig. 3. PMID:242282

  6. Index for Inclusion

    ERIC Educational Resources Information Center

    Smith, Allister

    2005-01-01

    Index for Inclusion is a programme to assist in developing learning and participation in schools. It was written by Tony Booth and Mel Ainscow from the Centre for Studies on Inclusive Education, UK. Central Normal School was pleased to have the opportunity to trial this programme.

  7. Bacterial meningitis.

    PubMed

    Heckenberg, Sebastiaan G B; Brouwer, Matthijs C; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained, preceding any imaging studies. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, and an altered level of consciousness but signs may be scarce in children, in the elderly, and in meningococcal disease. Host genetic factors are major determinants of susceptibility to meningococcal and pneumococcal disease. Dexamethasone therapy has been implemented as adjunctive treatment of adults with pneumococcal meningitis. Adequate and prompt treatment of bacterial meningitis is critical to outcome. In this chapter we review the epidemiology, pathophysiology, and management of bacterial meningitis. © 2014 Elsevier B.V. All rights reserved.

  8. Fluid inclusion geothermometry

    USGS Publications Warehouse

    Cunningham, C.G.

    1977-01-01

    Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.

  9. Becoming Inclusive: A Code of Conduct for Inclusion and Diversity.

    PubMed

    Schmidt, Bonnie J; MacWilliams, Brent R; Neal-Boylan, Leslie

    There are increasing concerns about exclusionary behaviors and lack of diversity in the nursing profession. Exclusionary behaviors, which may include incivility, bullying, and workplace violence, discriminate and isolate individuals and groups who are different, whereas inclusive behaviors encourage diversity. To address inclusion and diversity in nursing, this article offers a code of conduct. This code of conduct builds on existing nursing codes of ethics and applies to nursing students and nurses in both educational and practice settings. Inclusive behaviors that are demonstrated in nurses' relationships with patients, colleagues, the profession, and society are described. This code of conduct provides a basis for measureable change, empowerment, and unification of the profession. Recommendations, implications, and a pledge to action are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Insulating epoxy/barite and polyester/barite composites for radiation attenuation.

    PubMed

    El-Sarraf, M A; El-Sayed Abdo, A

    2013-09-01

    A trial has been made to create insulating Epoxy/Barite (EP/Brt) (ρ=2.85 g cm(-3)) and Crosslinked Unsaturated Polyester/Barite (CUP/Brt) (ρ=3.25 g cm(-3)) composites with radiation attenuation and shielding capabilities. Experimental work regarding mechanical and physical properties was performed to study the composites integrity for practical applications. The properties were found to be reasonable. Radiation attenuation properties have been carried out using emitted collimated beam from a fission (252)Cf (100 µg) neutron source, and the neutron-gamma spectrometer with stilbene scintillator. The pulse shape discriminating (P.S.D) technique based on the zero cross-over method was used to discriminate between neutron and gamma-ray pulses. Thermal neutron fluxes, measured using the BF3 detector and thermal neutron detection system, were used to plot the attenuation relations. The fast neutron macroscopic effective removal cross-section ΣR, gamma ray total attenuation coefficient µ and thermal neutron macroscopic cross-section Σ have been evaluated. Theoretical calculations have been achieved using MCNP-4C2 code to calculate ΣR, µ and Σ. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ΣR. Measured and calculated results have been compared and were found to be in reasonable agreement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Cellular internalization and transport of biodegradable polyester dendrimers on a model of the pulmonary epithelium and their formulation in pressurized metered-dose inhalers.

    PubMed

    Heyder, Rodrigo S; Zhong, Qian; Bazito, Reinaldo C; da Rocha, Sandro R P

    2017-03-30

    The purpose of this study was to evaluate the effect of generation and surface PEGylation of degradable polyester-based dendrimers nanocarriers on their interactions with an in vitro model of the pulmonary epithelium as well as to assess the ability to formulate such carriers in propellant-based, portable oral-inhalation devices to determine their potential for local and systemic delivery of drugs to and through the lungs. Hydroxyl (-OH) terminated polyester dendrimers of generation 3 and 4 (G3, and G4) were synthesized using a divergent approach. G4 was surface-modified with PEG (1,000Da). All dendrimers and their building blocks were determined to be highly compatible with the model pulmonary epithelium, with toxicity profiles much more favorable than non-degradable polyamidoamine dendrimers (PAMAM). The transport of the species from the apical to basolateral side across polarized Calu-3 monolayers showed to be generation and surface-chemistry (PEGylation) dependent. The extent of the transport is modulated by their interaction with the polarized epithelium and their transient opening of the tight junctions. G3 was the one most efficiently internalized by the epithelium, and had a small impact on the integrity of the monolayer. On the other hand, the PEGylated G4 was the one least internalized by the polarized epithelium, and at the same time had a more pronounced transient impact on the cellular junctions, resulting in more efficient transport across the cell monolayer. PEGylation of the dendrimer surface played other roles as well. PEGylation modulated the degradation profile of the dendrimer, slowing the process in a step-wise fashion - first the PEG layer is shed and then the dendrimer starts degrading. PEGylation also helped increase the solvation of the nanocarriers by the hydrofluoroalkane propellant used in pressurized metered-dose inhalers, resulting in formulations with excellent dispersibility and aerosol quality (deep lung deposition of 88

  12. Fluid inclusions in stony meteorites

    NASA Technical Reports Server (NTRS)

    Warner, J. L.; Ashwal, L. D.; Bergman, S. C.; Gibson, E. K., Jr.; Henry, D. J.; Lee-Berman, R.; Roedder, E.; Belkin, H. E.

    1983-01-01

    The fluid inclusions presently described for five stony meteorites brings to seven the number of such meteorites confirmed. Homogenization temperatures are reproducible in each inclusion, and range from 25 C to over 225 C, with some vapor plus liquid inclusions remaining at 225 C, the highest temperature in these microthermometric experiments. Upon cooling, the fluid in some inclusions appears to freeze, as indicated by deformation and immobilization of the vapor bubble at low temperatures. Melting temperatures are by contrast difficult to observe and are not reproducible. Microthermometric data for the fluid in diogenite ALPHA 77256 and inclusions in four chondrites suggest that the fluid is aqueous, with a high solute content.

  13. Polyester Textiles as a Source of Microplastics from Households: A Mechanistic Study to Understand Microfiber Release During Washing.

    PubMed

    Hernandez, Edgar; Nowack, Bernd; Mitrano, Denise M

    2017-06-20

    Microplastic fibers make up a large proportion of microplastics found in the environment, especially in urban areas. There is good reason to consider synthetic textiles a major source of microplastic fibers, and it will not diminish since the use of synthetic fabrics, especially polyester, continues to increase. In this study we provide quantitative data regarding the size and mass of microplastic fibers released from synthetic (polyester) textiles during simulated home washing under controlled laboratory conditions. Consideration of fabric structure and washing conditions (use of detergents, temperature, wash duration, and sequential washings) allowed us to study the propensity of fiber shedding in a mechanistic way. Thousands of individual fibers were measured (number, length) from each wash solution to provide a robust data set on which to draw conclusions. Among all the variables tested, the use of detergent appeared to affect the total mass of fibers released the most, yet the detergent composition (liquid or powder) or overdosing of detergent did not significantly influence microplastic release. Despite different release quantities due to the addition of a surfactant (approximately 0.025 and 0.1 mg fibers/g textile washed, without and with detergent, respectively), the overall microplastic fiber length profile remained similar regardless of wash condition or fabric structure, with the vast majority of fibers ranging between 100 and 800 μm in length irrespective of wash cycle number. This indicates that the fiber staple length and/or debris encapsulated inside the fabric from the yarn spinning could be directly responsible for releasing stray fibers. This study serves as a first look toward understanding the physical properties of the textile itself to better understand the mechanisms of fiber shedding in the context of microplastic fiber release into laundry wash water.

  14. Nanotubular Toughening Inclusions

    NASA Technical Reports Server (NTRS)

    Park, Cheol (Inventor); Working, Dennis C. (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

    2017-01-01

    Conventional toughening agents are typically rubbery materials or small molecular weight molecules, which mostly sacrifice the intrinsic properties of a matrix such as modulus, strength, and thermal stability as side effects. On the other hand, high modulus inclusions tend to reinforce elastic modulus very efficiently, but not the strength very well. For example, mechanical reinforcement with inorganic inclusions often degrades the composite toughness, encountering a frequent catastrophic brittle failure triggered by minute chips and cracks. Thus, toughening generally conflicts with mechanical reinforcement. Carbon nanotubes have been used as efficient reinforcing agents in various applications due to their combination of extraordinary mechanical, electrical, and thermal properties. Moreover, nanotubes can elongate more than 20% without yielding or breaking, and absorb significant amounts of energy during deformation, which enables them to also be an efficient toughening agent, as well as excellent reinforcing inclusion. Accordingly, an improved toughening method is provided by incorporating nanotubular inclusions into a host matrix, such as thermoset and thermoplastic polymers or ceramics without detrimental effects on the intrinsic physical properties of the matrix.

  15. Nanotubular Toughening Inclusions

    NASA Technical Reports Server (NTRS)

    Park, Cheol (Inventor); Working, Dennis C. (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

    2015-01-01

    Conventional toughening agents are typically rubbery materials or small molecular weight molecules, which mostly sacrifice the intrinsic properties of a matrix such as modulus, strength, and thermal stability as side effects. On the other hand, high modulus inclusions tend to reinforce elastic modulus very efficiently, but not the strength very well. For example, mechanical reinforcement with inorganic inclusions often degrades the composite toughness, encountering a frequent catastrophic brittle failure triggered by minute chips and cracks. Thus, toughening generally conflicts with mechanical reinforcement. Carbon nanotubes have been used as efficient reinforcing agents in various applications due to their combination of extraordinary mechanical, electrical, and thermal properties. Moreover, nanotubes can elongate more than 20% without yielding or breaking, and absorb significant amounts of energy during deformation, which enables them to also be an efficient toughening agent, as well as excellent reinforcing inclusion. Accordingly, an improved toughening method is provided by incorporating nanotubular inclusions into a host matrix, such as thermoset and thermoplastic polymers or ceramics without detrimental effects on the matrix's intrinsic physical properties.

  16. Enzyme-Catalyzed Synthesis of Unsaturated Aliphatic Polyesters Based on Green Monomers from Renewable Resources

    PubMed Central

    Jiang, Yi; Woortman, Albert J.J.; Alberda van Ekenstein, Gert O.R.; Loos, Katja

    2013-01-01

    Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR results confirm that carbon-carbon double bonds are well preserved in PBSI. The differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results indicate that the amount of itaconate in the co-polyesters has no obvious effects on the glass-transition temperature and the thermal stability of PBS and PBSI, but has significant effects on the melting temperature. PMID:24970176

  17. Removal of inclusions from silicon

    NASA Astrophysics Data System (ADS)

    Ciftja, Arjan; Engh, Thorvald Abel; Tangstad, Merete; Kvithyld, Anne; Øvrelid, Eivind Johannes

    2009-11-01

    The removal of inclusions from molten silicon is necessary to satisfy the purity requirements for solar grade silicon. This paper summarizes two methods that are investigated: (i) settling of the inclusions followed by subsequent directional solidification and (infiltration by ceramic foam filters. Settling of inclusions followed by directional solidification is of industrial importance for production of low-cost solar grade silicon. Filtration is reported as the most efficient method for removal of inclusions from the top-cut silicon scrap.

  18. Assembly of the Cutin Polyester: From Cells to Extracellular Cell Walls.

    PubMed

    Bakan, Bénédicte; Marion, Didier

    2017-11-18

    Cuticular matrices covering aerial plant organs or delimiting compartments in these organs are composed of an insoluble hydrophobic polymer of high molecular mass, i.e., cutin, that encompass some cell wall polysaccharides and is filled by waxes. Cutin is a polyester of hydroxy and-or epoxy fatty acids including a low amount of glycerol. Screening of Arabidopsis and more recently of tomato ( Solanum lycopersicum ) mutants allowed the delineation of the metabolic pathway involved in the formation of cutin monomers, as well as their translocation in the apoplast. Furthermore, these studies identified an extracellular enzyme involved in the polymerization of these monomers, i.e., cutin synthase 1 (CUS1), an acyl transferase of the GDSL lipase protein family. By comparing the structure of tomato fruit cutins from wild type and down-regulated CUS1 mutants, as well as with the CUS1-catalyzed formation of oligomers in vitro, hypothetical models can be elaborated on the polymerization of cutins. The polymorphism of the GDSL-lipase family raises a number of questions concerning the function of the different isoforms in relation with the formation of a composite material, the cuticle, containing entangled hydrophilic and hydrophobic polymers, i.e., polysaccharides and cutin, and plasticizers, i.e., waxes.

  19. Biodegradable polyester-based microcarriers with modified surface tailored for tissue engineering.

    PubMed

    Privalova, A; Markvicheva, E; Sevrin, Ch; Drozdova, M; Kottgen, C; Gilbert, B; Ortiz, M; Grandfils, Ch

    2015-03-01

    Microcarriers have been proposed in tissue engineering, namely for bone, cartilage, skin, vascular, and central nervous system. Although polyester-based microcarriers have been already used for this purpose, their surface properties should be improved to provide better cell growth. The goal of this study was to prepare microbeads based on poly(D,L-lactide) acid, poly(L-lactide) acid, and to study cell behavior (adhesion, spreading, growth, and proliferation) in function of microbead topography and surface chemistry. To improve L-929 fibroblasts adhesion, microbead surface has been modified with three polycations: chitosan, poly(2-dimethylamino ethylmethacrylate) (PDMAEMA), or chitosan-g-oligolactide copolymer (chit-g-OLA). Although modification of the microbead surface with chitosan and PDMAEMA was performed through physical adsorption on the previously prepared microbeads, chit-g-OLA copolymer was introduced directly during microbead processing. This simple approach (1) bypass the use of an emulsifier (polyvinyl alcohol, PVA); (2) avoid surface "contamination" with PVA molecules limiting a control of the surface characteristics. In vitro study of the growth of mouse fibroblasts on the microbeads showed that both surface topography and chemistry affected cell attachment, spreading, and proliferation. Cultivation of L-929 fibroblasts for 7 days resulted in the formation of a 3D cell-scaffold network. © 2014 Wiley Periodicals, Inc.

  20. Dark proteins: effect of inclusion body formation on quantification of protein expression.

    PubMed

    Iafolla, Marco A J; Mazumder, Mostafizur; Sardana, Vandit; Velauthapillai, Tharsan; Pannu, Karanbir; McMillen, David R

    2008-09-01

    Plasmid-borne gene expression systems have found wide application in the emerging fields of systems biology and synthetic biology, where plasmids are used to implement simple network architectures, either to test systems biology hypotheses about issues such as gene expression noise or as a means of exerting artificial control over a cell's dynamics. In both these cases, fluorescent proteins are commonly applied as a means of monitoring the expression of genes in the living cell, and efforts have been made to quantify protein expression levels through fluorescence intensity calibration and by monitoring the partitioning of proteins among the two daughter cells after division; such quantification is important in formulating the predictive models desired in systems and synthetic biology research. A potential pitfall of using plasmid-based gene expression systems is that the high protein levels associated with expression from plasmids can lead to the formation of inclusion bodies, insoluble aggregates of misfolded, nonfunctional proteins that will not generate fluorescence output; proteins caught in these inclusion bodies are thus "dark" to fluorescence-based detection methods. If significant numbers of proteins are incorporated into inclusion bodies rather than becoming biologically active, quantitative results obtained by fluorescent measurements will be skewed; we investigate this phenomenon here. We have created two plasmid constructs with differing average copy numbers, both incorporating an unregulated promoter (P(LtetO-1) in the absence of TetR) expressing the GFP derivative enhanced green fluorescent protein (EGFP), and inserted them into Escherichia coli bacterial cells (a common model organism for work on the dynamics of prokaryotic gene expression). We extracted the inclusion bodies, denatured them, and refolded them to render them active, obtaining a measurement of the average number of EGFP per cell locked into these aggregates; at the same time, we used

  1. K + block is the mechanism of functional asymmetry in bacterial Na v channels

    DOE PAGES

    Ngo, Van; Wang, Yibo; Haas, Stephan; ...

    2016-01-04

    Crystal structures of several bacterial Na v channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Na v channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial Na vAb channel. This approach provided new insight into the mechanism of selective ion permeation inmore » bacterial Nav channels. The non-equilibrium simulations indicate that two or three extracellular K + ions can block the entrance to the selectivity filter of Na vAb in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be ‘locked’ in place bymodest applied forces. In contrast to K +, three Na + ions move favorably through the selectivity filter together as a unit in a loose “knock-on” mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na + ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K + block is equivalent to large applied potentials experimentally measured for two bacterial Na v channels to induce inward currents of K + ions. Here, these results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed

  2. Lending a Helping Hand at Work: A Multilevel Investigation of Prosocial Motivation, Inclusive Climate and Inclusive Behavior.

    PubMed

    Nelissen, Philippe T J H; Hülsheger, Ute R; van Ruitenbeek, Gemma M C; Zijlstra, Fred R H

    2017-09-01

    Purpose People with disabilities often encounter difficulties at the workplace such as exclusion or unfair treatment. Researchers have therefore pointed to the need to focus on behavior that fosters inclusion as well as variables that are antecedents of such 'inclusive behavior'. Therefore the purpose of this study was to research the relationship between prosocial motivation, team inclusive climate and employee inclusive behavior. Method A survey was conducted among a sample of 282 paired employees and colleagues, which were nested in 84 teams. Employees self-rated prosocial motivation and team inclusive climate, their inclusive behavior was assessed by colleagues. Hypotheses were tested using multilevel random coefficient modeling. Results Employees who are prosocially motivated will display more inclusive behavior towards people with disabilities, and this relationship is moderated by team inclusive climate in such a way that the relationship is stronger when the inclusive climate is high. Conclusion This study shows that inclusive organizations, which value a diverse workforce, need to be aware of not only individual employee characteristics, but also team level climate to ensure the smooth integrations of people with disabilities into regular work teams.

  3. Polyester type polyHIPE scaffolds with an interconnected porous structure for cartilage regeneration

    NASA Astrophysics Data System (ADS)

    Naranda, Jakob; Sušec, Maja; Maver, Uroš; Gradišnik, Lidija; Gorenjak, Mario; Vukasović, Andreja; Ivković, Alan; Rupnik, Marjan Slak; Vogrin, Matjaž; Krajnc, Peter

    2016-06-01

    Development of artificial materials for the facilitation of cartilage regeneration remains an important challenge in orthopedic practice. Our study investigates the potential for neocartilage formation within a synthetic polyester scaffold based on the polymerization of high internal phase emulsions. The fabrication of polyHIPE polymer (PHP) was specifically tailored to produce a highly porous (85%) structure with the primary pore size in the range of 50-170 μm for cartilage tissue engineering. The resulting PHP scaffold was proven biocompatible with human articular chondrocytes and viable cells were observed within the materials as evaluated using the Live/Dead assay and histological analysis. Chondrocytes with round nuclei were organized into multicellular layers on the PHP surface and were observed to grow approximately 300 μm into the scaffold interior. The accumulation of collagen type 2 was detected using immunohistochemistry and chondrogenic specific genes were expressed with favorable collagen type 2 to 1 ratio. In addition, PHP samples are biodegradable and their baseline mechanical properties are similar to those of native cartilage, which enhance chondrocyte cell growth and proliferation.

  4. Polyester type polyHIPE scaffolds with an interconnected porous structure for cartilage regeneration

    PubMed Central

    Naranda, Jakob; Sušec, Maja; Maver, Uroš; Gradišnik, Lidija; Gorenjak, Mario; Vukasović, Andreja; Ivković, Alan; Rupnik, Marjan Slak; Vogrin, Matjaž; Krajnc, Peter

    2016-01-01

    Development of artificial materials for the facilitation of cartilage regeneration remains an important challenge in orthopedic practice. Our study investigates the potential for neocartilage formation within a synthetic polyester scaffold based on the polymerization of high internal phase emulsions. The fabrication of polyHIPE polymer (PHP) was specifically tailored to produce a highly porous (85%) structure with the primary pore size in the range of 50–170 μm for cartilage tissue engineering. The resulting PHP scaffold was proven biocompatible with human articular chondrocytes and viable cells were observed within the materials as evaluated using the Live/Dead assay and histological analysis. Chondrocytes with round nuclei were organized into multicellular layers on the PHP surface and were observed to grow approximately 300 μm into the scaffold interior. The accumulation of collagen type 2 was detected using immunohistochemistry and chondrogenic specific genes were expressed with favorable collagen type 2 to 1 ratio. In addition, PHP samples are biodegradable and their baseline mechanical properties are similar to those of native cartilage, which enhance chondrocyte cell growth and proliferation. PMID:27340110

  5. Comparison of three distinct surgical clothing systems for protection from air-borne bacteria: A prospective observational study

    PubMed Central

    2012-01-01

    Background To prevent surgical site infection it is desirable to keep bacterial counts low in the operating room air during orthopaedic surgery, especially prosthetic surgery. As the air-borne bacteria are mainly derived from the skin flora of the personnel present in the operating room a reduction could be achieved by using a clothing system for staff made from a material fulfilling the requirements in the standard EN 13795. The aim of this study was to compare the protective capacity between three clothing systems made of different materials – one mixed cotton/polyester and two polyesters - which all had passed the tests according to EN 13795. Methods Measuring of CFU/m3 air was performed during 21 orthopaedic procedures performed in four operating rooms with turbulent, mixing ventilation with air flows of 755 – 1,050 L/s. All staff in the operating room wore clothes made from the same material during each surgical procedure. Results The source strength (mean value of CFU emitted from one person per second) calculated for the three garments were 4.1, 2.4 and 0.6 respectively. In an operating room with an air flow of 755 L/s both clothing systems made of polyester reduced the amount of CFU/m3 significantly compared to the clothing system made from mixed material. In an operating room with air intake of 1,050 L/s a significant reduction was only achieved with the polyester that had the lowest source strength. Conclusions Polyester has a better protective capacity than cotton/polyester. There is need for more discriminating tests of the protective efficacy of textile materials intended to use for operating garment. PMID:23068884

  6. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    NASA Astrophysics Data System (ADS)

    Ishak, M. R.; Leman, Z.; Sapuan, S. M.; Edeerozey, A. M. M.; Othman, I. S.

    2010-05-01

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  7. Heart valves from polyester fibers: a preliminary 6-month in vivo study.

    PubMed

    Vaesken, Antoine; Pelle, Anne; Pavon-Djavid, Graciela; Rancic, Jeanne; Chakfe, Nabil; Heim, Frederic

    2018-06-27

    Transcatheter aortic valve implantation (TAVI) has become a popular alternative technique to surgical valve replacement for critical patients. Biological valve tissue has been used in TAVI procedures for over a decade, with over 150,000 implantations to date. However, with only 6 years of follow up, little is known about the long-term durability of biological tissue. Moreover, the high cost of tissue harvesting and chemical treatment procedures favor the development of alternative synthetic valve leaflet materials. In that context, textile polyester [polyethylene terephthalate (PET)] could be considered as an interesting candidate to replace the biological valve leaflets in TAVI procedures. However, no result is available in the literature about the behavior of textile once in contact with biological tissue in the valve position. The interaction of synthetic textile material with living tissues should be comparable to biological tissue. The purpose of this preliminary work is to compare the in vivo performances of various woven textile PET valves over a 6-month period in order to identify favorable textile construction features. In vivo results indicate that fibrosis as well as calcium deposit can be limited with an appropriate material design.

  8. Diverse Perspectives on Inclusive School Communities

    ERIC Educational Resources Information Center

    Tsokova, Diana; Tarr, Jane

    2012-01-01

    What is an inclusive school community? How do stakeholders perceive their roles and responsibilities towards inclusive school communities? How can school communities become more inclusive through engagement with individual perspectives? "Diverse Perspectives on Inclusive School Communities" captures and presents the voices of a wide…

  9. Study of the chain conformation of thermotropic nematic main chain polyesters

    NASA Astrophysics Data System (ADS)

    Li, M. H.; Brûlet, A.; Cotton, J. P.; Davidson, P.; Strazielle, C.; Keller, P.

    1994-10-01

    The conformation of main chain mesomorphic polyesters is studied by small angle neutron scattering (SANS) in the isotropic and in the nematic phases, by using mixtures of deuterated and undeuterated polymers. Particular attention is given to neglect the transesterification effects occurring mainly at high temperature for these LC polymers. In the isotropic phase, despite the presence of long rigid mesogenic groups, the LC polyester chains have a Gaussian conformation shown by the variation of the radius of gyration as a function of the molecular weight. This result is confirmed from the scattering variation in the intermediate range of the scattering vector. In the nematic phase, the SANS data are well fitted to a model of cylinder, in which the main chain polymer is confined. In the unoriented phase, the measurements in the intermediate range give the values of the radii of cylinders : they lie in between 10 Å and 19 Å depending on the degree of polymerization of chains. In the oriented nematic phase, the scattering patterns are highly anisotropic : they correspond to very long, thin and well-oriented cylinders. We have calculated the fully extended chain lengths using for the monomer length that measured in situ by X-ray diffraction. Then the comparison of this length with the measured height of the cylinders gives the existence of hairpins and their number per chain. For the short chain, the conformation is almost completely elongated in the nematic direction, whereas hairpin defects appear in longer chains. Their number decreases slightly with decreasing temperature. The orientational fluctuations of cylinders relatively to the nematic director are weak as shown from the high values of their order parameter (P_2 > 0.9). These results are discussed for two spacer lengths as a function of the molecular weight and of the temperature. La conformation de polyesters linéaires mésomorphes est étudiée par diffusion de neutrons aux petits angles (DNPA) dans les

  10. A review of social inclusion measures.

    PubMed

    Coombs, Tim; Nicholas, Angela; Pirkis, Jane

    2013-10-01

    Social inclusion is crucial to mental health and well-being and is emphasised in Australia's Fourth National Mental Health Plan. There is a recognition that a measure of social inclusion would complement the suite of outcome measures that is currently used in public sector mental health services. This paper is an initial scope of candidate measures of social inclusion and considers their suitability for this purpose. We identified potential measures through searches of PsycINFO and Medline and a more general Internet search. We extracted descriptive and evaluative information on each measure identified and compared this information with a set of eight criteria. The criteria related to the measure's inclusion of four domains of social inclusion outlined in Australia's Fourth National Mental Health Plan, its usability within the public mental health sector and its psychometric properties. We identified 10 candidate measures of social inclusion: the Activity and Participation Questionnaire (APQ-6); the Australian Community Participation Questionnaire (ACPQ); the Composite Measure of Social Inclusion (CMSI); the EMILIA Project Questionnaire (EPQ); the Evaluating Social Inclusion Questionnaire (ESIQ); the Inclusion Web (IW); the Social and Community Opportunities Profile (SCOPE); the Social Inclusion Measure (SIM); the Social Inclusion Questionnaire (SIQ); and the Staff Survey of Social Inclusion (SSSI). After comparison with the eight review criteria, we determined that the APQ-6 and the SCOPE-short form show the most potential for further testing. Social inclusion is too important not to measure. This discussion of individual-level measures of social inclusion provides a springboard for selecting an appropriate measure for use in public sector mental health services. It suggests that there are two primary candidates, but neither of these is quite fit-for-purpose in their current form. Further exploration will reveal whether one of these is suitable, whether another

  11. Exploring Preservice Teachers' Attitudes Towards Inclusion

    ERIC Educational Resources Information Center

    Killoran, Isabel; Woronko, Dagmara; Zaretsky, Hayley

    2014-01-01

    This study responds to a call for research into existing teacher-education programmes and their impact on teacher candidates' attitudes. An inclusive education course that examined the difference between "soft inclusion" (inclusion which addresses the issue of place rather than substance of learning) and genuine inclusion was used to…

  12. Shock Re-equilibration of Fluid Inclusions

    NASA Technical Reports Server (NTRS)

    Madden, M. E. Elwood; Horz, F.; Bodnar, R. J.

    2004-01-01

    Fluid inclusions (microscopic volumes of fluid trapped within minerals as they precipitate) are extremely common in terrestrial minerals formed under a wide range of geological conditions from surface evaporite deposits to kimberlite pipes. While fluid inclusions in terrestrial rocks are nearly ubiquitous, only a few fluid inclusion-bearing meteorites have been documented. The scarcity of fluid inclusions in meteoritic materials may be a result of (a) the absence of fluids when the mineral was formed on the meteorite parent body or (b) the destruction of fluid inclusions originally contained in meteoritic materials by subsequent shock metamorphism. However, the effects of impact events on pre-existing fluid inclusions trapped in target and projectile rocks has received little study. Fluid inclusions trapped prior to the shock event may be altered (re-equilibrated) or destroyed due to the high pressures, temperatures, and strain rates associated with impact events. By examining the effects of shock deformation on fluid inclusion properties and textures we may be able to better constrain the pressure-temperature path experienced by terrestrial and meteoritic shocked materials and also gain a clearer understanding of why fluid inclusions are rarely found in meteorite samples.

  13. Inclusive Education under Collectivistic Culture

    ERIC Educational Resources Information Center

    Futaba, Yasuko

    2016-01-01

    This paper addresses how inclusive education under collective culture is possible. Inclusive education, which more-or-less involves changing the current schools, has been denied, doubted or distorted by both policy-makers and practitioners of general and special education in Japan. Main reason for the setback in inclusive education can be…

  14. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  15. Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pinzon, NM; Aukema, KG; Gralnick, JA

    A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone productionmore » as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones. IMPORTANCE In recent years, there has been renewed interest in advanced biofuel sources such as bacterial hydrocarbon production. Previous studies used solvent extraction of bacterial cultures followed by gas chromatography-mass spectrometry (GC-MS) to detect and quantify ketones and hydrocarbons (Beller HR, Goh EB, Keasling JD, Appl. Environ. Microbiol. 76: 1212-1223, 2010; Sukovich DJ, Seffernick JL, Richman JE, Gralnick JA, Wackett LP, Appl. Environ. Microbiol. 76: 3850-3862, 2010). While these analyses are powerful and accurate, their labor-intensive nature makes them intractable to high-throughput screening; therefore, methods for rapid identification of bacterial strains that are overproducing hydrocarbons are needed. The use of high

  16. Inclusive Education in South Korea

    ERIC Educational Resources Information Center

    Kim, Yong-Wook

    2014-01-01

    The purpose of this paper is to examine the current implementation of inclusive education in South Korea and discuss its challenges. The history of special education is first described followed by an introduction to policies relevant to special and inclusive education. Next, a critical discussion of the state of inclusive education follows built…

  17. Inclusion complex from cyclodextrin-grafted hyaluronic acid and pseudo protein as biodegradable nano-delivery vehicle for gambogic acid.

    PubMed

    Ji, Ying; Shan, Shuo; He, Mingyu; Chu, Chih-Chang

    2017-10-15

    β-Cyclodextrin can form inclusion complex with a series of guest molecules including phenyl moieties, and has gained considerable popularity in the study of supramolecular nanostructure. In this study, a biodegradable nanocomplex (HA(CD)-4Phe4 nanocomplex) was developed from β-cyclodextrin grafted hyaluronic acid (HA) and phenylalanine based poly(ester amide). The phenylalanine based poly(ester amide) is a biodegradable pseudo protein which provides the encapsulation capacity for gambogic acid (GA), a naturally-derived chemotherapeutic which has been effectively employed to treat multidrug resistant tumor. The therapeutic potency of free GA is limited due to its poor solubility in water and the lack of tumor-selective toxicity. The nanocomplex carrier enhanced the solubility and availability of GA in aqueous media, and the HA component enabled the targeted delivery to tumor cells with overexpression of CD44 receptors. In the presence of hyaluronidase, the release of GA from the nanocomplex was significantly accelerated, due to the enzymatic biodegradation of the carrier. Compared to free GA, GA-loaded nanocomplex exhibited improved cytotoxicity in MDA-MB-435/MDR multidrug resistant melanoma cells, and induced enhanced level of apoptosis and mitochondrial depolarization, at low concentration of GA (1-2µM). The nanocomplex enhanced the therapeutic potency of GA, especially when diluted in physiological environment. In addition, suppressed matrix metalloproteinase activity was also detected in MDA-MB-435/MDR cells treated by GA-loaded nanocomplex, which demonstrated its potency in the inhibition of tumor metastasis. The in vitro data suggested that HA(CD)-4Phe4 nanocomplex could provide a promising alternative in the treatment of multidrug resistant tumor cells. Gambogic acid (GA), naturally derived from genus Garcinia trees, exhibited significant cytotoxic activity against multiple types of tumors with resistance to traditional chemotherapeutics. Unfortunately

  18. Inclusion in High-Achieving Singapore: Challenges of Building an Inclusive Society in Policy and Practice

    ERIC Educational Resources Information Center

    Walker, Zachary; Musti-Rao, Shobana

    2016-01-01

    Building an inclusive society in which all people can participate effectively and live together requires understanding inclusive education and its impact on the social order. As countries of different regions face the vast array of challenges unique to their educational systems, it becomes apparent that inclusive societies are intricately tied to…

  19. IMPACT OF MICROBIOLOGICAL CHANGES ON SPONTANEOUS BACTERIAL PERITONITIS IN THREE DIFFERENT PERIODS OVER 17 YEARS.

    PubMed

    Almeida, Paulo Roberto Lerias de; Leão, Gabriel Stefani; Gonçalves, Charlles David Gonçalves; Picon, Rafael Veiga; Tovo, Cristiane Valle

    2018-01-01

    Spontaneous bacterial peritonitis is a serious complication in cirrhotic patients, and changes in the microbiological characteristics reported in the last years are impacting the choice of antibiotic used for treatment. The aim of the present study is to evaluate the changes in the epidemiology and bacterial resistance of the germs causing spontaneous bacterial peritonitis over three different periods over 17 years. All cirrhotic patients with spontaneous bacterial peritonitis and positive culture of ascites fluid were retrospectively studied in a reference Hospital in Southern Brazil. Three periods were ramdomly evaluated: 1997-1998, 2002-2003 and 2014-2015. The most frequent infecting organisms and the sensitivity in vitro to antibiotics were registered. In the first period (1997-1998) there were 33 cases, the most common were: E. coli in 13 (36.11%), Staphylococcus coagulase-negative in 6 (16.66%), K. pneumoniae in 5 (13.88%), S. aureus in 4 (11.11%) and S. faecalis in 3 (8.33%). In the second period (2002-2003), there were 43 cases, the most frequent were: Staphylococus coagulase-negative in 16 (35.55%), S. aureus in 8 (17.77%), E. coli in 7 (15.55%) and K. pneumoniae in 3 (6.66%). In the third period (2014-2015) there were 58 cases (seven with two bacteria), the most frequent were: E. coli in 15 (23.1%), S. viridans in 12 (18.5%), K. pneumoniae in 10 (15.4%) and E. faecium 5 (7.7%). No one was using antibiotic prophylaxis. Considering all staphylococci, the prevalence increased to rates of the order of 50% in the second period, with a reduction in the third period evaluated. Likewise, the prevalence of resistant E. coli increased, reaching 14%. There was a modification of the bacterial population causing spontaneous bacterial peritonitis, with high frequency of gram-positive organisms, as well as an increase in the resistance to the traditionally recommended antibiotics. This study suggests a probable imminent inclusion of a drug against gram

  20. Structural differences in the bacterial flagellar motor among bacterial species.

    PubMed

    Terashima, Hiroyuki; Kawamoto, Akihiro; Morimoto, Yusuke V; Imada, Katsumi; Minamino, Tohru

    2017-01-01

    The bacterial flagellum is a supramolecular motility machine consisting of the basal body as a rotary motor, the hook as a universal joint, and the filament as a helical propeller. Intact structures of the bacterial flagella have been observed for different bacterial species by electron cryotomography and subtomogram averaging. The core structures of the basal body consisting of the C ring, the MS ring, the rod and the protein export apparatus, and their organization are well conserved, but novel and divergent structures have also been visualized to surround the conserved structure of the basal body. This suggests that the flagellar motors have adapted to function in various environments where bacteria live and survive. In this review, we will summarize our current findings on the divergent structures of the bacterial flagellar motor.

  1. Contribution To Degradation Study, Behavior Of Unsaturated Polyester Resin Under Neutron Irradiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abellache, D.; Lounis, A.; Taiebi, K.

    2010-01-05

    Applications of unsaturated polyester thermosetting resins are numerous in construction sector, in transport, electric spare parts manufactures, consumer goods, and anticorrosive materials. This survey reports the effect of thermosetting polymer degradation (unsaturated polyester): degradation by neutrons irradiation. In order to evaluate the deterioration of our material, some comparative characterizations have been done between standard samples and damaged ones. Scanning electron microscopy (SEM), ultrasonic scanning, hardness test (Shore D) are the techniques which have been used. The exposure to a neutrons flux is carried out in the column of the nuclear research reactor of Draria (Algiers-Algeria). The energetic profile of themore » incidental fluxes is constituted of fast neutrons (PHI{sub R} = 3.10{sup 12} n.cm{sup -2}.s{sup -1}, E = 2 Mev) of thermal neutrons (PHI{sub TH} = 10{sup 13} n.cm{sup -2}.s{sup -1}; E = 0.025 ev) and epithermal neutrons (PHI{sub epi} = 7.10{sup 11} n.cm{sup -2}.s{sup -1}; E>4,9 ev). The received dose flow is 0,4 Kgy. We notice only a few scientific investigations can be found in this field. In comparison with the standard sample (no exposed) it is shown that the damage degree is an increasing process with the exposure. Concerning the description of irradiation effects on polymers, we can advance that several reactions are in competition: reticulation, chain break, and oxidation by radical mechanism. In our case the incidental particle of high energy fast neutrons whose energy is greater or equal to 2 Mev, is braked by the target with a nuclear shock during which the incidental particle transmits a part of its energy to an atom. If the energy transfer is sufficient, the nuclear shock permits to drive out an atom of its site the latter will return positioning interstitially, the energy that we used oversteps probably the energy threshold (displacement energy). This fast neutrons collision with target cores proceeds to an indirect

  2. Crack-Inclusion Interaction: A Review

    DTIC Science & Technology

    2014-03-01

    research on the problem. fracture mechanics, inclusion, crack, dislocation, Erdogan , Dundurs, integral equation, Green’s function 58 Christopher S. Meyer...14 Figure 9. Geometry for the crack-inclusion problem, adapted from Erdogan and Wei (21) . . . 23 Figure 10. The...crack-inclusion problem geometry, adapted from Erdogan and Wei (21): figure 9 is repeated here in the text for convenience

  3. Nanobarium Titanate As Supplement To Accelerate Plastic Waste Biodegradation By Indigenous Bacterial Consortia

    NASA Astrophysics Data System (ADS)

    Kapri, Anil; Zaidi, M. G. H.; Goel, Reeta

    2009-06-01

    Plastic waste biodegradation studies have seen several developmental phases from the discovery of potential microbial cultures, inclusion of photo-oxidizable additives into the polymer chain, to the creation of starch-embedded biodegradable plastics. The present study deals with the supplementation of nanobarium titanate (NBT) in the minimal broth in order to alter the growth-profiles of the Low-density polyethylene (LDPE) degrading consortia. The pro-bacterial influence of the nanoparticles could be seen by substantial changes such as shortening of the lag phase and elongation of the exponential as well as stationary growth phases, respectively, which eventually increase the biodegradation efficiency. In-vitro biodegradation studies revealed better dissolution of LDPE in the presence of NBT as compared to control. Significant shifting in λ-max values was observed in the treated samples through UV-Vis spectroscopy, while Fourier transform infrared spectroscopy (FTIR) and simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) further confirmed the breakage and formation of bonds in the polymer backbone. Therefore, this study suggests the implementation of NBT as nutritional additive for plastic waste management through bacterial growth acceleration.

  4. Socially Inclusive Pedagogy in Literacy Classes: Fostering Inclusion in the Inner City

    ERIC Educational Resources Information Center

    Cleovoulou, Yiola

    2008-01-01

    Drawing on case studies of five elementary school teachers in one inner city school, the author explored ways teachers foster social inclusion in their classrooms. Rooted in classroom observations and extensive teacher interviews, teachers' teaching methods and practices were examined as a base from which to explore socially inclusive pedagogy in…

  5. Bacterial mycophagy: definition and diagnosis of a unique bacterial-fungal interaction.

    PubMed

    Leveau, Johan H J; Preston, Gail M

    2008-01-01

    This review analyses the phenomenon of bacterial mycophagy, which we define as a set of phenotypic behaviours that enable bacteria to obtain nutrients from living fungi and thus allow the conversion of fungal into bacterial biomass. We recognize three types of bacterial strategies to derive nutrition from fungi: necrotrophy, extracellular biotrophy and endocellular biotrophy. Each is characterized by a set of uniquely sequential and differently overlapping interactions with the fungal target. We offer a detailed analysis of the nature of these interactions, as well as a comprehensive overview of methodologies for assessing and quantifying their individual contributions to the mycophagy phenotype. Furthermore, we discuss future prospects for the study and exploitation of bacterial mycophagy, including the need for appropriate tools to detect bacterial mycophagy in situ in order to be able to understand, predict and possibly manipulate the way in which mycophagous bacteria affect fungal activity, turnover, and community structure in soils and other ecosystems.

  6. SU-E-T-115: Dose Perturbation Study of Self-Expandable Metal and Polyester Esophageal Stents in Proton Therapy Beams

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, S; Li, Z; Jalaj, S

    2014-06-01

    Purpose: This work investigates dose perturbations due to Self-expandable metal and polyester esophageal stents undergoing proton radiotherapy for esophageal cancer. Methods: Five commercially available esophageal stents made of nitinol (Evolution, Wallflex and Ultraflex), stainless steel (Z-Stent) and polyester (Polyflex) were tested. Radiochromic film (GafChromic EBT3 film, Ashland, Covington, KY) wrapped around a stent and a 12cc syringe was irradiated with 2CGE (Cobalt Gray Equivalent) of proton beam in a custom fabricated acrylic phantom. An air-hollow syringe simulates the esophagus. Results: The Z-stent created the largest dose perturbations ranges from -14.5% to 6.1% due to the steel composition. The WallFlex, Evolutionmore » and Ultraflex stents produced the dose perturbation ranges of (−9.2%∼8.6%), (−6.8%∼5.7%) and (−6.2%∼6.2%), respectively. The PolyFlex stent contains the radiopaque tungsten markers located top, middle and bottom portions. When the focal cold spots induced by the markers were excluded in the analysis, the dose perturbation range was changed from (−11.6%∼6.4%) to (−0.6%∼5.0%). Conclusion: The magnitude of dose perturbation is related to material of a metallic stent. The non-metallic stent such as PolyFlex shows relatively lower dose perturbation than metallic stents except a radiopaque marker region. Overall Evolution and Ultraflex stent appear to be less dose perturbations. The largest dose perturbations (cold spots) were located at both edges of stents in distal area for the single proton beam irradiation study. The analysis of more than two proton beam which is more typical clinical beam arrangement would be necessary to minimize the doe perturbation effect in proton ratiotherapy.« less

  7. Resources on Inclusive Education.

    ERIC Educational Resources Information Center

    Hulgin, Kathy, Ed.

    This information packet is intended for use by teachers, parents, administrators, therapists, advocates, and others interested in achieving inclusive educational opportunities for students with disabilities. Part I provides reprints of selected readings, including: "Sample Case Studies of Inclusive Education" (Janet Duncan); "Public Schools…

  8. Using melt inclusions and fluid inclusions to track ore-metal behavior in magma-hydrothermal systems (Invited)

    NASA Astrophysics Data System (ADS)

    Lowenstern, J. B.; Audétat, A.

    2013-12-01

    Melt and fluid inclusions yield important clues to the history of igneous melts and their related hydrothermal ore deposits (1). Under ideal conditions, melt inclusions in volcanic rocks yield data on the actual concentrations of ore metals and volatiles during instantaneous snapshots of crystallization and degassing. Their varying compositions can directly reflect sequestration of ore-metals in fractionating minerals and/or exsolving brines and vapors. Frequently, scientists compare the concentration of volatile elements in melt inclusions with their abundance in devolatilized matrix glass. Though this provides an informative qualitative overview of volatility, it is essentially impossible to use such data to calculate thermodynamically relevant partition coefficients. The resulting partitioning ratio instead represents fractionation over a wide range of pressures, and compositions (for both exsolved fluid and silicate melt). Ideally, workers should identify co-entrapped fluid and glass inclusions to provide more thermodynamically meaningful partitioning ratios for volatile metals and gases (2,3). Unfortunately, the occurrence of fluid inclusions co-entrapped with silicate melt is relatively rare, and studies of synthetic fluid and melt inclusions may be the most practical means of exploring the effect of crystallization and degassing in 'natural' systems. As with melt inclusions, under ideal conditions, fluid inclusions in intrusive rocks represent the compositions of fluids generated within associated magmatic-hydrothermal fluid systems. Multiple generations of cross-cutting fractures may be generated, resulting in trails of secondary and pseudosecondary inclusions in igneous minerals, and primary and secondary inclusions in hydrothermal assemblages. Chemistry of the fluids preserved within different inclusion generations will change markedly due to changes in magmatic temperature and pressure and mixing of diverse external fluids from meteoric and metamorphic

  9. Cellular damage in bacterial meningitis: an interplay of bacterial and host driven toxicity.

    PubMed

    Weber, Joerg R; Tuomanen, Elaine I

    2007-03-01

    Bacterial meningitis is still an important infectious disease causing death and disability. Invasive bacterial infections of the CNS generate some of the most powerful inflammatory responses known in medicine. Although the components of bacterial cell surfaces are now chemically defined in exquisite detail and the interaction with several receptor pathways has been discovered, it is only very recently that studies combining these advanced biochemical and cell biological tools have been done. Additional to the immunological response direct bacterial toxicity has been identified as an important contributor to neuronal damage. A detailed understanding of the complex interaction of bacterial toxicity and host response may generate opportunities for innovative and specific neuroprotective therapies.

  10. Melt inclusions: Chapter 6

    USGS Publications Warehouse

    ,; Lowenstern, J. B.

    2014-01-01

    Melt inclusions are small droplets of silicate melt that are trapped in minerals during their growth in a magma. Once formed, they commonly retain much of their initial composition (with some exceptions) unless they are re-opened at some later stage. Melt inclusions thus offer several key advantages over whole rock samples: (i) they record pristine concentrations of volatiles and metals that are usually lost during magma solidification and degassing, (ii) they are snapshots in time whereas whole rocks are the time-integrated end products, thus allowing a more detailed, time-resolved view into magmatic processes (iii) they are largely unaffected by subsolidus alteration. Due to these characteristics, melt inclusions are an ideal tool to study the evolution of mineralized magma systems. This chapter first discusses general aspects of melt inclusions formation and methods for their investigation, before reviewing studies performed on mineralized magma systems.

  11. Bacterial surface adaptation

    NASA Astrophysics Data System (ADS)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  12. Fast procedure for the analysis of poly(hydroxyalkanoates) in bacterial cells by off-line pyrolysis/gas-chromatography with flame ionization detector.

    PubMed

    Torri, Cristian; Cordiani, Helena; Samorì, Chiara; Favaro, Lorenzo; Fabbri, Daniele

    2014-09-12

    Poly(hydroxyalkanoates) (PHAs) are polyesters formed by saturated short chain hydroxyacids, among which 3-hydroxybutanoic (HB) and 3-hydroxypentanoic (3-hydroxyvalerate, HV) are the most common monomers of homopolymers (e.g. poly(3-hydroxybutyrate), PHB) and copolymers (e.g. poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), PHB-HC). The most widely used approach for their determination is the polymer methanolysis followed by gas chromatography-mass spectrometry (GC-MS) analysis of the methylated monomers; this procedure generally requires the use of additional reagents (e.g. sulfuric acid) and is performed with harmful chlorinated solvents, such as chloroform. The development of fast routine solventless methods for the quantitative determination of PHAs and their monomeric composition is highly desirable to reduce sample pretreatment, speed up the analysis and decrease overall costs. It has been reported that under thermal treatment (e.g. pyrolysis, Py), PHAs are degraded in high yield (>40%, w/wPHA) into the corresponding 2-alkenoic acid (e.g. crotonic acid from PHB). This work aimed at investigating this reaction for direct analysis of PHAs in bacterial cells. The sample was directly subjected to pyrolysis and trapped pyrolysis products were analyzed by GC-FID. Off-line Py/GC-FID was first optimized on pure polymers with different monomer composition (PHB, PHB-HV, PHB-HC) and then applied to bacterial samples deriving from both mixed microbial cultures or selected strains, containing various types and amounts of PHAs. The Py/GC-FID method provided RSD <15% range, limit of detection of 100μg (1% PHAs in biomass), and results comparable to that of methanolysis (R(2)=0.9855), but with minimal sample pretreatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Innovation for an Inclusive Future

    NASA Astrophysics Data System (ADS)

    Springett, Mark; Rice, Mark; Carmichael, Alex; Griffiths, Richard

    This workshop will focus on setting the agenda for research, practice and policy in support of inclusive design for third generation computer-based products. The next generation of technology represents an unprecedented opportunity to improve the quality of life for groups of users who have previously faced exclusion, such as those with impairments and older citizens. At the same time it risks creating a greater digital divide and further exclusion. How we approach design for this new generation will determine whether or not the third wave will provide positive advances towards an inclusive digital world. We therefore need to put forward both a rationale for inclusive design and provide pointers towards technical development and design practice in support of inclusion. It is our belief that there is not only a strong moral case for design for inclusion but also significant commercial incentive, which may be key to persuading influential players to focus on inclusion. Therefore one of our key objectives is to describe and promote the advantages of designing ‘in from the edges’ of the user population rather than designing for a notional ‘average’ user.

  14. Bacterial mimetics of endocrine secretory granules as immobilized in vivo depots for functional protein drugs

    PubMed Central

    Céspedes, María Virtudes; Fernández, Yolanda; Unzueta, Ugutz; Mendoza, Rosa; Seras-Franzoso, Joaquin; Sánchez-Chardi, Alejando; Álamo, Patricia; Toledo-Rubio, Verónica; Ferrer-Miralles, Neus; Vázquez, Esther; Schwartz, Simó; Abasolo, Ibane; Corchero, José Luis; Mangues, Ramon; Villaverde, Antonio

    2016-01-01

    In the human endocrine system many protein hormones including urotensin, glucagon, obestatin, bombesin and secretin, among others, are supplied from amyloidal secretory granules. These granules form part of the so called functional amyloids, which within the whole aggregome appear to be more abundant than formerly believed. Bacterial inclusion bodies (IBs) are non-toxic, nanostructured functional amyloids whose biological fabrication can be tailored to render materials with defined biophysical properties. Since under physiological conditions they steadily release their building block protein in a soluble and functional form, IBs are considered as mimetics of endocrine secretory granules. We have explored here if the in vivo implantation of functional IBs in a given tissue would represent a stable local source of functional protein. Upon intratumoral injection of bacterial IBs formed by a potent protein ligand of CXCR4 we have observed high stability and prevalence of the material in absence of toxicity, accompanied by apoptosis of CXCR4+ cells and tumor ablation. Then, the local immobilization of bacterial amyloids formed by therapeutic proteins in tumors or other tissues might represent a promising strategy for a sustained local delivery of protein drugs by mimicking the functional amyloidal architecture of the mammals’ endocrine system. PMID:27775083

  15. C-reactive Protein Versus Neutrophil/lymphocyte Ratio in Differentiating Bacterial and Non-bacterial Pneumonia in Children.

    PubMed

    Gauchan, E; Adhikari, S

    2016-09-01

    Pneumonia is a leading cause of childhood mortality in a low resource country. Simple laboratory markers can help differentiate between bacterial and non-bacterial pneumonias for appropriate management. In children aged one to 60 months with features of lower respiratory infection, C-reactive protein (CRP) and neutrophil-lymphocyte ratio (NLR) were used to differentiate between bacterial and non-bacterial pneumonias. The cutoff values for detecting bacterial pneumonias were evaluated by statistical tools. Bacterial pneumonia was diagnosed in 285 (43.6%) children out of 654 studied. At a cut-off value of 36 mg/L CRP was predictive of bacterial pneumonias with sensitivity and specificity of 61.8% and 91.3% respectively while the sensitivity and specificity for predicting bacterial pneumonia using NLR was 45.6% and 64% respectively with 1.28 used as a cut-off. Our study shows that CRP is superior to NLR in differentiating bacterial from non-bacterial pneumonias in children.

  16. Co-precipitation of protein and polyester as a method to isolate high molecular weight DNA.

    PubMed

    Dixson, Jamie D

    2005-02-01

    DNA isolation is often the limiting step in genetic analysis using PCR and automated fragment analysis due to low quality or purity of DNA, the need to determine and adjust DNA concentrations after isolation etc. Several protocols have been developed which are either safe and provide good quality DNA or hazardous and provide excellent quality DNA. In this brief communication I describe a new and rapid method of DNA isolation which employs the co-precipitation of protein and polyester, in the presence of acetone, to remove contaminating proteins from a lysed-tissue sample, thus leaving high quality pure DNA. The advantages of this method are increased safety over the phenol:chloroform and the chaotrophic salt methods and increased purity over the salting-out method. Since the concentrations of DNA isolated using this method are relatively consistent regardless of the amount of starting tissue (within limits), adjustments of the DNA concentrations before use as templates in PCR's are not necessary.

  17. Isosorbide as the structural component of bio-based unsaturated polyesters for use as thermosetting resins.

    PubMed

    Sadler, Joshua M; Toulan, Faye R; Nguyen, Anh-Phuong T; Kayea, Ronald V; Ziaee, Saeed; Palmese, Giuseppe R; La Scala, John J

    2014-01-16

    In recent years, the development of renewable bio-based resins has gained interest as potential replacements for petroleum based resins. Modified carbohydrate-based derivatives have favorable structural features such as fused bicyclic rings that offer promising candidates for the development of novel renewable polymers with improved thermomechanical properties when compared to early bio-based resins. Isosorbide is one such compound and has been utilized as the stiffness component for the synthesis of novel unsaturated polyesters (UPE) resins. Resin blends of BioUPE systems with styrene were shown to possess viscosities (120-2200 cP) amenable to a variety of liquid molding techniques, and after cure had Tgs (53-107 °C) and storage moduli (430-1650 MPa) that are in the desired range for composite materials. These investigations show that BioUPEs containing isosorbide can be tailored during synthesis of the prepolymer to meet the needs of different property profiles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Fluid therapy for acute bacterial meningitis.

    PubMed

    Maconochie, Ian K; Bhaumik, Soumyadeep

    2016-11-04

    Acute bacterial meningitis remains a disease with high mortality and morbidity rates. However, with prompt and adequate antimicrobial and supportive treatment, the chances for survival have improved, especially among infants and children. Careful management of fluid and electrolyte balance is an important supportive therapy. Both over- and under-hydration are associated with adverse outcomes. This is the latest update of a review first published in 2005 and updated in 2008 and 2014. To evaluate treatment of acute bacterial meningitis with differing volumes of initial fluid administration (up to 72 hours after first presentation) and the effects on death and neurological sequelae. For this 2016 update we searched the following databases up to March 2016: the Cochrane Acute Respiratory Infections Group's Specialised Register, CENTRAL, MEDLINE, CINAHL, Global Health, and Web of Science. Randomised controlled trials (RCTs) of differing volumes of fluid given in the initial management of bacterial meningitis were eligible for inclusion. All four of the original review authors extracted data and assessed trials for quality in the first publication of this review (one author, ROW, has passed away since the original review; see Acknowledgements). The current authors combined data for meta-analysis using risk ratios (RRs) for dichotomous data or mean difference (MD) for continuous data. We used a fixed-effect statistical model. We assessed the overall quality of evidence using the GRADE approach. We included three trials with a total of 420 children; there were no trials in adult populations. The largest of the three trials was conducted in settings with high mortality rates and was judged to have low risk of bias for all domains, except performance bias which was high risk. The other two smaller trials were not of high quality.The meta-analysis found no significant difference between the maintenance-fluid and restricted-fluid groups in number of deaths (RR 0.82, 95

  19. Inclusive Services Innovation Configuration

    ERIC Educational Resources Information Center

    Holdheide, Lynn R.; Reschly, Daniel J.

    2011-01-01

    Teacher preparation to deliver inclusive services to students with disabilities is increasingly important because of changes in law and policy emphasizing student access to, and achievement in, the general education curriculum. This innovation configuration identifies the components of inclusive services that should be incorporated in teacher…

  20. Cloning and molecular characterization of a glycerol-3-phosphate O-acyltransferase (GPAT) gene from Echium (Boraginaceae) involved in the biosynthesis of cutin polyesters.

    PubMed

    Mañas-Fernández, Aurora; Li-Beisson, Yonghua; Alonso, Diego López; García-Maroto, Federico

    2010-09-01

    The glycerol-based lipid polyester called cutin is a main component of cuticle, the protective interface of aerial plant organs also controlling compound exchange with the environment. Though recent progress towards understanding of cutin biosynthesis has been made in Arabidopsis thaliana, little is known in other plants. One key step in this process is the acyl transfer reaction to the glycerol backbone. Here we report the cloning and molecular characterization of EpGPAT1, a gene encoding a glycerol-3-phosphate O-acyltransferase (GPAT) from Echium pitardii (Boraginaceae) with high similarity to the AtGPAT4/AtGPAT8 of Arabidopsis. Quantitative analysis by qRT-PCR showed highest expression of EpGPAT1 in seeds, roots, young leaves and flowers. Acyltransferase activity of EpGPAT1 was evidenced by heterologous expression in yeast. Ectopic expression in leaves of tobacco plants lead to an increase of C16 and C18 hydroxyacids and alpha,omega-diacids in the cell wall fraction, indicating a role in the biosynthesis of polyesters. Analysis of the genomic organization in Echium revealed the presence of EpGPAT2, a closely related gene which was found to be mostly expressed in developing leaves and flowers. The presence of a conserved HAD-like domain at the N-terminal moiety of GPATs from Echium, Arabidopsis and other plant species suggests a possible phosphohydrolase activity in addition to the reported acyltransferase activity. Evolutive implications of this finding are discussed.

  1. Procalcitonin and C-reactive protein as markers of bacterial infection in critically ill children at onset of systemic inflammatory response syndrome.

    PubMed

    Simon, Liliana; Saint-Louis, Patrick; Amre, Devendra K; Lacroix, Jacques; Gauvin, France

    2008-07-01

    To compare the accuracy of procalcitonin and C-reactive protein as diagnostic markers of bacterial infection in critically ill children at the onset of systemic inflammatory response syndrome (SIRS). Prospective cohort study. Tertiary care, university-affiliated pediatric intensive care unit (PICU). Consecutive patients with SIRS. From June to December 2002, all PICU patients were screened daily to include cases of SIRS. At inclusion (onset of SIRS), procalcitonin and C-reactive protein levels as well as an array of cultures were obtained. Diagnosis of bacterial infection was made a posteriori by an adjudicating process (consensus of experts unaware of the results of procalcitonin and C-reactive protein). Baseline and daily data on severity of illness, organ dysfunction, and outcome were collected. Sixty-four patients were included in the study and were a posteriori divided into the following groups: bacterial SIRS (n = 25) and nonbacterial SIRS (n = 39). Procalcitonin levels were significantly higher in patients with bacterial infection compared with patients without bacterial infection (p = .01). The area under the receiver operating characteristic curve for procalcitonin was greater than that for C-reactive protein (0.71 vs. 0.65, respectively). A positive procalcitonin level (>or=2.5 ng/mL), when added to bedside clinical judgment, increased the likelihood of bacterial infection from 39% to 92%, while a negative C-reactive protein level (<40 mg/L) decreased the probability of bacterial infection from 39% to 2%. Procalcitonin is better than C-reactive protein for differentiating bacterial from nonbacterial SIRS in critically ill children, although the accuracy of both tests is moderate. Diagnostic accuracy could be enhanced by combining these tests with bedside clinical judgment.

  2. When Inclusion Is Innovation: An Examination of Administrator Perspectives on Inclusion in China

    ERIC Educational Resources Information Center

    Hu, Bi Ying; Roberts, Sherron Killingsworth

    2011-01-01

    This article examines administrator perspectives of innovative services for the inclusion of young children with disabilities in regular preschool classrooms in China. Twelve directors from 12 pilot inclusion preschools in Beijing participated in this study. Qualitative interview results revealed the following subthemes: definition, advocacy,…

  3. Alternative preparation of inclusion bodies excludes interfering non-protein contaminants and improves the yield of recombinant proinsulin.

    PubMed

    Mackin, Robert B

    2014-01-01

    The goal of simple, high-yield expression and purification of recombinant human proinsulin has proven to be a considerable challenge. First, proinsulin forms inclusion bodies during bacterial expression. While this phenomenon can be exploited as a capture step, conventionally prepared inclusion bodies contain significant amounts of non-protein contaminants that interfere with subsequent chromatographic purification. Second, the proinsulin molecules within the inclusion bodies are incorrectly folded, and likely cross-linked to one another, making it difficult to quantify the amount of expressed proinsulin. Third, proinsulin is an intermediate between the initial product of ribosomal translation (preproinsulin) and the final product secreted by pancreatic beta cells (insulin). Therefore, to be efficiently produced in bacteria, it must be produced as an N-terminally extended fusion protein, which has to be converted to authentic proinsulin during the purification scheme. To address all three of these problems, while simultaneously streamlining the procedure and increasing the yield of recombinant proinsulin, we have made three substantive modifications to our previous method for producing proinsulin:.•Conditions for the preparation of inclusion bodies have been altered so contaminants that interfere with semi-preparative reversed-phase chromatography are excluded while the proinsulin fusion protein is retained at high yield.•Aliquots are taken following important steps in the procedure and the quantity of proinsulin-related polypeptide in the sample is compared to the amount present prior to that step.•Final purification is performed using a silica-based reversed-phase matrix in place of a polystyrene-divinylbenzene-based matrix.

  4. Alternative preparation of inclusion bodies excludes interfering non-protein contaminants and improves the yield of recombinant proinsulin

    PubMed Central

    Mackin, Robert B.

    2014-01-01

    The goal of simple, high-yield expression and purification of recombinant human proinsulin has proven to be a considerable challenge. First, proinsulin forms inclusion bodies during bacterial expression. While this phenomenon can be exploited as a capture step, conventionally prepared inclusion bodies contain significant amounts of non-protein contaminants that interfere with subsequent chromatographic purification. Second, the proinsulin molecules within the inclusion bodies are incorrectly folded, and likely cross-linked to one another, making it difficult to quantify the amount of expressed proinsulin. Third, proinsulin is an intermediate between the initial product of ribosomal translation (preproinsulin) and the final product secreted by pancreatic beta cells (insulin). Therefore, to be efficiently produced in bacteria, it must be produced as an N-terminally extended fusion protein, which has to be converted to authentic proinsulin during the purification scheme. To address all three of these problems, while simultaneously streamlining the procedure and increasing the yield of recombinant proinsulin, we have made three substantive modifications to our previous method for producing proinsulin:.•Conditions for the preparation of inclusion bodies have been altered so contaminants that interfere with semi-preparative reversed-phase chromatography are excluded while the proinsulin fusion protein is retained at high yield.•Aliquots are taken following important steps in the procedure and the quantity of proinsulin-related polypeptide in the sample is compared to the amount present prior to that step.•Final purification is performed using a silica-based reversed-phase matrix in place of a polystyrene-divinylbenzene-based matrix. PMID:26150942

  5. Embracing Inclusive Teacher Education

    ERIC Educational Resources Information Center

    Moran, Anne

    2007-01-01

    This paper examines the extent to which initial teacher education (ITE) programmes contribute to the development of inclusive attitudes, values and practices. Inclusive education is the entitlement of all children and young people to quality education, irrespective of their differences or dispositions. It is about embracing educational values of…

  6. Geometric Modeling of Inclusions as Ellipsoids

    NASA Technical Reports Server (NTRS)

    Bonacuse, Peter J.

    2008-01-01

    Nonmetallic inclusions in gas turbine disk alloys can have a significant detrimental impact on fatigue life. Because large inclusions that lead to anomalously low lives occur infrequently, probabilistic approaches can be utilized to avoid the excessively conservative assumption of lifing to a large inclusion in a high stress location. A prerequisite to modeling the impact of inclusions on the fatigue life distribution is a characterization of the inclusion occurrence rate and size distribution. To help facilitate this process, a geometric simulation of the inclusions was devised. To make the simulation problem tractable, the irregularly sized and shaped inclusions were modeled as arbitrarily oriented, three independent dimensioned, ellipsoids. Random orientation of the ellipsoid is accomplished through a series of three orthogonal rotations of axes. In this report, a set of mathematical models for the following parameters are described: the intercepted area of a randomly sectioned ellipsoid, the dimensions and orientation of the intercepted ellipse, the area of a randomly oriented sectioned ellipse, the depth and width of a randomly oriented sectioned ellipse, and the projected area of a randomly oriented ellipsoid. These parameters are necessary to determine an inclusion s potential to develop a propagating fatigue crack. Without these mathematical models, computationally expensive search algorithms would be required to compute these parameters.

  7. Direct Conversion of an Enzyme from Native-like to Amyloid-like Aggregates within Inclusion Bodies.

    PubMed

    Elia, Francesco; Cantini, Francesca; Chiti, Fabrizio; Dobson, Christopher Martin; Bemporad, Francesco

    2017-06-20

    The acylphosphatase from Sulfolobus solfataricus (Sso AcP) is a globular protein able to aggregate in vitro from a native-like conformational ensemble without the need for a transition across the major unfolding energy barrier. This process leads to the formation of assemblies in which the protein retains its native-like structure, which subsequently convert into amyloid-like aggregates. Here, we investigate the mechanism by which Sso AcP aggregates in vivo to form bacterial inclusion bodies after expression in E. coli. Shortly after the initiation of expression, Sso AcP is incorporated into inclusion bodies as a native-like protein, still exhibiting small but significant enzymatic activity. Additional experiments revealed that this overall process of aggregation is enhanced by the presence of the unfolded N-terminal region of the sequence and by destabilization of the globular segment of the protein. At later times, the Sso AcP molecules in the inclusion bodies lose their native-like properties and convert into β-sheet-rich amyloid-like structures, as indicated by their ability to bind thioflavin T and Congo red. These results show that the aggregation behavior of this protein is similar in vivo to that observed in vitro, and that, at least for a predominant part of the protein population, the transition from a native to an amyloid-like structure occurs within the aggregate state. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. Polyester modification of the mammalian TRPM8 channel protein: Implications for structure and function

    PubMed Central

    Bikard, Yann; Chen, Wei; Liu, Tong; Li, Hong; Jendrossek, Dieter; Cohen, Alejandro; Pavlov, Evgeny; Rohacs, Tibor; Zakharian, Eleonora

    2013-01-01

    SUMMARY The TRPM8 ion channel is expressed in sensory neurons and is responsible for sensing environmental cues such as cold temperatures and chemical compounds, including menthol and icilin. The channel functional activity is regulated by various physical and chemical factors, and is likely to be pre-conditioned by its molecular composition. Our studies indicate that TRPM8 channel forms a structural-functional complex with the polyester, poly-(R)-3hydroxybutyrate (PHB). We identified by mass spectrometry a number of PHB-modified peptides in the N-terminus of the TRPM8 protein and in its extracellular S3–S4 linker. Removal of PHB by enzymatic hydrolysis, and site-directed mutagenesis of both the serine residues that serve as covalent anchors for PHB and adjacent hydrophobic residues that interact with the methyl groups of the polymer, resulted in significant inhibition of TRPM8 channel activity. We conclude that the TRPM8 channel undergoes post-translational modification by PHB and that this modification is required for its normal function. PMID:23850286

  9. Waterborne carboxyl-terminated hyperbranched oligomer polyester ligand: Synthesis, characterization and chelation with chromium(III)

    NASA Astrophysics Data System (ADS)

    Yao, Qi; Li, Chenying; Huang, Henghui; Chen, Hualin; Liu, Bailing

    2017-09-01

    A series of carboxyl-terminated hyperbranched oligomer polyester (HBP) with different degree of branching (DB) and number average molar mass (Mbarn) have been prepared. The molecular structure, degree of branching, molecular mass and its distribution of HBP were investigated by FTIR, 1H NMR, and GPC, respectively. And the coordination number, stability constant and degree of dissociation (α) between HBP and chromium(Ⅲ) were measured via continuous variation method (Job's plot). Experimental results show that the coordination capability between HBP and chromium(Ⅲ) affected by both DB and molecular mass, and the latter plays a decisive role. Moreover HBP outperforms low molecular weight of organic acids (citric acid, acetic acid) and linear polyacrylic acid with similar molecular mass. The coordination number and stability constants of HBP-3 (Mbarn = 1713 Da, Mbarw /Mbarn (PDI) = 1.11 and DB = 0.72) can reach 4 and 6.55e+008, which demonstrated it can be selected as a good ligand to coordination with chromium(Ⅲ). Therefore HBP can be used as chrome auxiliary in chrome tanning to improve the absorption of chromium.

  10. Bacterial Prostatitis: Bacterial Virulence, Clinical Outcomes, and New Directions.

    PubMed

    Krieger, John N; Thumbikat, Praveen

    2016-02-01

    Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.

  11. Probing the molecular design of hyper-branched aryl polyesters towards lubricant applications

    PubMed Central

    Robinson, Joshua W.; Zhou, Yan; Bhattacharya, Priyanka; Erck, Robert; Qu, Jun; Bays, J. Timothy; Cosimbescu, Lelia

    2016-01-01

    We report novel polymeric materials that may be used as viscosity index improvers (VII) for lubricant applications. Our efforts included probing the comb-burst hyper-branched aryl polyester architecture for beneficial viscosity and friction behavior when utilized as an additive in a group I oil. The monomer was designed as to undergo polymerization via polycondensation within the architectural construct (AB2), typical of hyperbranched polymers. The monomer design was comprised of aliphatic arms (12 or 16 methylenes) to provide the necessary lipophilicity to achieve solubility in a non-polar medium. Once polymerized, via catalyst and heat, the surface alcohols were functionalized with fatty acids (lauric and palmitic). Controlling the aliphatic nature of the internal arms and peripheral end-groups provided four unique flexible polymer designs. Changing the reaction time and concentration provided opportunities to investigate the influence of molecular weight and branching density on oil-solubility, viscosity, and friction. Oil-solubility was found to decrease with fewer internal carbons, but the number of internal carbons appears to have little influence on the bulk solution viscosity. At concentrations of 2 wt % in a group I base oil, these polymer additives demonstrated an improved viscosity index and reduced friction coefficient, validating the basic approach. PMID:26727881

  12. Probing the molecular design of hyper-branched aryl polyesters towards lubricant applications

    NASA Astrophysics Data System (ADS)

    Robinson, Joshua W.; Zhou, Yan; Bhattacharya, Priyanka; Erck, Robert; Qu, Jun; Bays, J. Timothy; Cosimbescu, Lelia

    2016-01-01

    We report novel polymeric materials that may be used as viscosity index improvers (VII) for lubricant applications. Our efforts included probing the comb-burst hyper-branched aryl polyester architecture for beneficial viscosity and friction behavior when utilized as an additive in a group I oil. The monomer was designed as to undergo polymerization via polycondensation within the architectural construct (AB2), typical of hyperbranched polymers. The monomer design was comprised of aliphatic arms (12 or 16 methylenes) to provide the necessary lipophilicity to achieve solubility in a non-polar medium. Once polymerized, via catalyst and heat, the surface alcohols were functionalized with fatty acids (lauric and palmitic). Controlling the aliphatic nature of the internal arms and peripheral end-groups provided four unique flexible polymer designs. Changing the reaction time and concentration provided opportunities to investigate the influence of molecular weight and branching density on oil-solubility, viscosity, and friction. Oil-solubility was found to decrease with fewer internal carbons, but the number of internal carbons appears to have little influence on the bulk solution viscosity. At concentrations of 2 wt % in a group I base oil, these polymer additives demonstrated an improved viscosity index and reduced friction coefficient, validating the basic approach.

  13. Probing the molecular design of hyper-branched aryl polyesters towards lubricant applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, Joshua W.; Zhou, Yan; Bhattacharya, Priyanka

    We report novel polymeric materials that may be used as viscosity index improvers (VII) for lubricant applications. Our efforts included probing the comb-burst hyper-branched aryl polyester architecture for beneficial viscosity and friction behavior when utilized as an additive in a group I oil. The monomer was designed as to undergo polymerization via polycondensation within the architectural construct (AB2), typical of hyperbranched polymers. The monomer design was comprised of aliphatic arms (12 or 16 methylenes) to provide the necessary lipophilicity to achieve solubility in a non-polar medium. Once polymerized, via catalyst and heat, the surface alcohols were functionalized with fatty acidsmore » (lauric and palmitic). Controlling the aliphatic nature of the internal arms and peripheral end-groups provided four unique flexible polymer designs. Changing the reaction time and concentration provided opportunities to investigate the influence of molecular weight and branching density on oil-solubility, viscosity, and friction. Oil-solubility was found to decrease with fewer internal carbons, but the number of internal carbons appears to have little influence on the bulk solution viscosity. At concentrations of 2 wt % in a group I base oil, these polymer additives demonstrated an improved viscosity index and reduced friction coefficient, validating the basic approach.« less

  14. Inclusive Schools. Topical Bibliography on Inclusive Schools.

    ERIC Educational Resources Information Center

    Sorenson, Barbara, Comp.; Drill, Janet, Comp.

    This abstract bibliography of approximately 200 references looks at various aspects of inclusive schools. References are a result of computer searches of three databases: the Educational Resources Information Center (ERIC), Exceptional Child Education Resources, and the Western Regional Resources Center. Preliminary information includes directions…

  15. Sliding inclusions and their applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mura, T.

    It is found that when an ellipsoidal inclusion undergoes a shear eigenstrain and the inclusion is free to slip along the interface, the stress field vanishes everywhere in the inclusion and the matrix. It is assumed in the analysis that the inclusion interface cannot sustain any shear traction. There exists a shear deformation which transforms an ellipsoid into the identical ellipsoid without changing its orientation (ellipsoid invariant transformation). Therefore, no resistance for shear deformation is expected. This may be a characteristic of deformation seen in superplasticity alloys and granular materials. The theory is valid even for large deformations when incrementalmore » strains (or strain rates) are considered instead of strains themselves.« less

  16. Adhesion of Blood Plasma Proteins and Platelet-rich Plasma on l-Valine-Based Poly(ester urea).

    PubMed

    Childers, Erin P; Peterson, Gregory I; Ellenberger, Alex B; Domino, Karen; Seifert, Gabrielle V; Becker, Matthew L

    2016-10-10

    The competitive absorption of blood plasma components including fibrinogen (FG), bovine serum albumin (BSA), and platelet-rich plasma (PRP) on l-valine-based poly(ester urea) (PEU) surfaces were investigated. Using four different PEU polymers, possessing compositionally dependent trends in thermal, mechanical, and critical surface tension measurements, water uptake studies were carried out to determine in vitro behavior of the materials. Quartz crystal microbalance (QCM) measurements were used to quantify the adsorption characteristics of PRP onto PEU thin films by coating the surfaces initially with FG or BSA. Pretreatment of the PEU surfaces with FG inhibited the adsorption of PRP and BSA decreased the absorption 4-fold. In vitro studies demonstrated that cells cultured on l-valine-based PEU thin films allowed attachment and spreading of rat aortic cells. These measurements will be critical toward efforts to use this new class of materials in blood-contacting biomaterials applications.

  17. Enzymatic Synthesis of Amino Acids Endcapped Polycaprolactone: A Green Route Towards Functional Polyesters.

    PubMed

    Duchiron, Stéphane W; Pollet, Eric; Givry, Sébastien; Avérous, Luc

    2018-01-30

    ε-caprolactone (CL) has been enzymatically polymerized using α-amino acids based on sulfur (methionine and cysteine) as (co-)initiators and immobilized lipase B of Candida antarctica (CALB) as biocatalyst. In-depth characterizations allowed determining the corresponding involved mechanisms and the polymers thermal properties. Two synthetic strategies were tested, a first one with direct polymerization of CL with the native amino acids and a second one involving the use of an amino acid with protected functional groups. The first route showed that mainly polycaprolactone (PCL) homopolymer could be obtained and highlighted the lack of reactivity of the unmodified amino acids due to poor solubility and affinity with the lipase active site. The second strategy based on protected cysteine showed higher monomer conversion, with the amino acids acting as (co-)initiators, but their insertion along the PCL chains remained limited to chain endcapping. These results thus showed the possibility to synthesize enzymatically polycaprolactone-based chains bearing amino acids units. Such cysteine endcapped PCL materials could then find application in the biomedical field. Indeed, subsequent functionalization of these polyesters with drugs or bioactive molecules can be obtained, by derivatization of the amino acids, after removal of the protecting group.

  18. Detecting and Correcting Melt Inclusion Modification

    NASA Astrophysics Data System (ADS)

    Cottrell, E.; Kelley, K. A.

    2008-12-01

    Post entrapment diffusive modification of melt inclusions may mute or erase primary signatures. Corrections for post-entrapment crystallization (PEC) and Fe-loss are routinely applied and, because recent experimental studies suggest rapid diffusion of trace components into and out of olivine-hosted inclusions, the ability to discriminate between primary and secondary signatures is now even more critical. Two tools may assist in this endeavor. XANES measurements of Fe3+/ΣFe ratios in undegassed ol-hosted basaltic melt inclusions from global arcs are 16-36% (n=16), significantly higher than the 7-10% commonly assumed, and higher than in MORB or BABB lavas (Kelley and Cottrell, this mtg). The Fe3+/ΣFe ratios indicate melt-host equilibrium, with significantly less PEC or Fe-loss than would have been otherwise assumed. We conclude that Fe2+ diffusion has been minimal; therefore the residence time of these primitive inclusions in an evolved magma must have been short. Fe3+/ΣFe correlates positively with water concentration, but not with CO2 and S concentrations or Mg#. The oxidized nature of arc lavas and melt inclusions may therefore indicate an oxidized source rather than late-stage degassing or fractionation. Trace element concentrations evolve with time if an inclusion is out of equilibrium with its host. The numerical model of Cottrell et al., 2002, makes specific predictions about how suites of melt inclusions evolve, creating a tool to detect post-entrapment modification. Recent laboratory measurements of REE diffusion in olivine greatly diverge (at 1300°C, 1015 vs 1019m2/s). If REE diffusivity is extremely fast, melt inclusion HREE diversity shouldn't survive more than a few years in a magma chamber; but if slow, HREE variance could be preserved for >104 yrs. Model analysis of published suites of ol-hosted inclusions indicates that either REE diffusion is quite slow, or the residence time of melt inclusions at high temperature is very short. Loss of variance

  19. Supporting Students with Severe Disabilities in Inclusive Schools: A Descriptive Account From Schools Implementing Inclusive Practices

    ERIC Educational Resources Information Center

    Kurth, Jennifer A.; Lyon, Kristin J.; Shogren, Karrie A.

    2015-01-01

    The purpose of the present study was to investigate practices that support the inclusion of students with severe disabilities in the learning and social activities of inclusive K-8 schools to inform inclusive school reform research and practice. Eighteen K-8 students with severe disabilities in six schools recognized for their implementation of…

  20. Inclusive Education: Identifying Teachers' Strategies for Coping with Perceived Stressors in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Brackenreed, Darlene

    2011-01-01

    This research replicates the study conducted by Forlin (2001) in Churchlands, Western Australia. Forlin's Inclusive Education "Teacher Stress and Coping Questionnaire" was adapted from the original questionnaire to more accurately reflect the language and practice of inclusion in Ontario. The purpose of this portion of the study was to…

  1. School Inclusion Programmes (SIPS)

    ERIC Educational Resources Information Center

    Drossinou-Korea, Maria; Matousi, Dimitra; Panopoulos, Nikolaos; Paraskevopoulou, Aikaterini

    2016-01-01

    The purpose of this work was to understand the school inclusion programmes (SIPs) for students with special educational needs (SEN). The methodology was conducted in the field of special education (SE) and focuses on three case studies of students who was supported by SIPs. The Targeted, Individual, Structured, Inclusion Programme for students…

  2. Estimating meningitis hospitalization rates for sentinel hospitals conducting invasive bacterial vaccine-preventable diseases surveillance.

    PubMed

    2013-10-04

    The World Health Organization (WHO)-coordinated Global Invasive Bacterial Vaccine-Preventable Diseases (IB-VPD) sentinel hospital surveillance network provides data for decision making regarding use of pneumococcal conjugate vaccine and Haemophilus influenzae type b (Hib) vaccine, both recommended for inclusion in routine childhood immunization programs worldwide. WHO recommends that countries conduct sentinel hospital surveillance for meningitis among children aged <5 years, including collection of cerebrospinal fluid (CSF) for laboratory detection of bacterial etiologies. Surveillance for pneumonia and sepsis are recommended at selected hospitals with well-functioning laboratories where meningitis surveillance consistently meets process indicators (e.g., surveillance performance indicators). To use sentinel hospital surveillance for meningitis to estimate meningitis hospitalization rates, WHO developed a rapid method to estimate the number of children at-risk for meningitis in a sentinel hospital catchment area. Monitoring changes in denominators over time using consistent methods is essential for interpreting changes in sentinel surveillance incidence data and for assessing the effect of vaccine introduction on disease epidemiology. This report describes the method and its use in The Gambia and Senegal.

  3. The malleable gut microbiome of juvenile rainbow trout (Oncorhynchus mykiss): Diet-dependent shifts of bacterial community structures

    PubMed Central

    Michl, Stéphanie Céline; Ratten, Jenni-Marie; Beyer, Matt; Hasler, Mario; LaRoche, Julie; Schulz, Carsten

    2017-01-01

    Plant-derived protein sources are the most relevant substitutes for fishmeal in aquafeeds. Nevertheless, the effects of plant based diets on the intestinal microbiome especially of juvenile Rainbow trout (Oncorhynchus mykiss) are yet to be fully investigated. The present study demonstrates, based on 16S rDNA bacterial community profiling, that the intestinal microbiome of juvenile Rainbow trout is strongly affected by dietary plant protein inclusion levels. After first feeding of juveniles with either 0%, 50% or 97% of total dietary protein content derived from plants, statistically significant differences of the bacterial gut community for the three diet-types were detected, both at phylum and order level. The microbiome of juvenile fish consisted mainly of the phyla Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria, and thus fits the salmonid core microbiome suggested in previous studies. Dietary plant proteins significantly enhanced the relative abundance of the orders Lactobacillales, Bacillales and Pseudomonadales. Animal proteins in contrast significantly promoted Bacteroidales, Clostridiales, Vibrionales, Fusobacteriales and Alteromonadales. The overall alpha diversity significantly decreased with increasing plant protein inclusion levels and with age of experimental animals. In order to investigate permanent effects of the first feeding diet-type on the early development of the microbiome, a diet change was included in the study after 54 days, but no such effects could be detected. Instead, the microbiome of juvenile trout fry was highly dependent on the actual diet fed at the time of sampling. PMID:28498878

  4. The malleable gut microbiome of juvenile rainbow trout (Oncorhynchus mykiss): Diet-dependent shifts of bacterial community structures.

    PubMed

    Michl, Stéphanie Céline; Ratten, Jenni-Marie; Beyer, Matt; Hasler, Mario; LaRoche, Julie; Schulz, Carsten

    2017-01-01

    Plant-derived protein sources are the most relevant substitutes for fishmeal in aquafeeds. Nevertheless, the effects of plant based diets on the intestinal microbiome especially of juvenile Rainbow trout (Oncorhynchus mykiss) are yet to be fully investigated. The present study demonstrates, based on 16S rDNA bacterial community profiling, that the intestinal microbiome of juvenile Rainbow trout is strongly affected by dietary plant protein inclusion levels. After first feeding of juveniles with either 0%, 50% or 97% of total dietary protein content derived from plants, statistically significant differences of the bacterial gut community for the three diet-types were detected, both at phylum and order level. The microbiome of juvenile fish consisted mainly of the phyla Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria, and thus fits the salmonid core microbiome suggested in previous studies. Dietary plant proteins significantly enhanced the relative abundance of the orders Lactobacillales, Bacillales and Pseudomonadales. Animal proteins in contrast significantly promoted Bacteroidales, Clostridiales, Vibrionales, Fusobacteriales and Alteromonadales. The overall alpha diversity significantly decreased with increasing plant protein inclusion levels and with age of experimental animals. In order to investigate permanent effects of the first feeding diet-type on the early development of the microbiome, a diet change was included in the study after 54 days, but no such effects could be detected. Instead, the microbiome of juvenile trout fry was highly dependent on the actual diet fed at the time of sampling.

  5. Frictional sliding inclusions

    NASA Astrophysics Data System (ADS)

    Huang, Jin H.; Furuhashi, R.; Mura, T.

    1993-02-01

    S OLUTIONS ARE presented in closed form by using an averaging method for inclusions sliding along an interface due to uniform eigenstrains precribed in the inclusions. The associated stress fields are also analytically determined. A parameter s is introduced to indicate the relative magnitude of sliding compared with the extreme cases of perfect bonding and perfect sliding. When the parameter s becomes zero, the present solution coincides with Eshelby's solution which is the perfectly bonded case. In contrast, when the parameter s is unity, the solution agrees with Volterra's solution (M URA and F URUHASHI, 1984, J. appl. Mech.51, 308] for the perfect sliding case. Because of non-uniform elastic fields caused by sliding along the interface, the well-known Eshelby tensor is modified for the sliding inclusions. Moreover, based on the Mori-Tanaka theory (M ORI and T ANAKA, 1973, Acta Metall.21, 571), an overall stress-strain relation is established to characterize the sliding effect on the overall elastic moduli.

  6. Inclusion Body Myositis

    PubMed Central

    Dimachkie, Mazen M.; Barohn, Richard J.

    2012-01-01

    The idiopathic inflammatory myopathies are a group of rare disorders that share many similarities. These include dermatomyositis (DM), polymyositis (PM), necrotizing myopathy (NM), and sporadic inclusion body myositis (IBM). Inclusion body myositis is the most common idiopathic inflammatory myopathy after age 50 and it presents with chronic proximal leg and distal arm asymmetric mucle weakness. Despite similarities with PM, it is likely that IBM is primarily a degenerative disorder rather than an inflammatory muscle disease. Inclusion body myositis is associated with a modest degree of creatine kinase (CK) elevation and an abnormal electromyogram demonstrating an irritative myopathy with some chronicity. The muscle histopathology demonstrates inflammatory exudates surrounding and invading nonnecrotic muscle fibers often times accompanied by rimmed vacuoles. In this chapter, we review sporadic IBM. We also examine past, essentially negative, clinical trials in IBM and review ongoing clinical trials. For further details on DM, PM, and NM, the reader is referred to the idiopathic inflammatory myopathies chapter. PMID:23117948

  7. Inclusive outreach practices in Palaeontology: Inclusive-Coworking

    NASA Astrophysics Data System (ADS)

    García-Frank, Alejandra; Gomez-Heras, Miguel; Fesharaki, Omid

    2017-04-01

    Previous experiences with people with both physical and intellectual functional diversity around palaeontological issues have demonstrated the important value of science outreach directed to people with disabilities. The aforementioned practices act twofold: as a learning tool and also improving the quality of life of the participants and thus, their self-image. All these pioneer experiences were the first step in a process of developing new attitudes contributing the 2030 Agenda for Sustainable Development of United Nations, where among the 17 goals proposed an effective social inclusion of people with disabilities is required. For this, real inclusive practices in geological outreach are imperious. A close cooperation with all the parts (researchers and participants), in a kind of coworking attitude is needed. This Inclusive-Coworking is considered in the sense of social gathering in order to share equal values and look for the synergy that this different outlook implies. And what is more important: the change of role of the previously learners into an active part of the scientific outreach, providing the adequate methodology for that. The offer of non-formal learning activities normally includes the participation of university professors and researchers in Science Week editions. During the 2016 session in Madrid, four adults with intellectual disability who were participants in the previous edition, contributed in the palaeontological workshop. They were in charge of four of the eight modules explaining the origin of fossils and how to collect them, the evolution of equids' limbs, and the main dentition types in vertebrates to the twenty 16 year old secondary students who attended the workshop. During the development of the experience all the students were pleased with the inclusive approach, and the interaction of all participants was fruitful. Although the explanations took a bit more time when made by our functional diverse fellows, all the abstracts concepts

  8. What Counts as Inclusion?

    ERIC Educational Resources Information Center

    Walton, E.; Nel, N.

    2012-01-01

    In the years since the publication in South Africa of White Paper Six: Special needs education (Department of Education (DoE) 2001) various schools in the state and independent sectors have begun to implement inclusive policies and practices. With reference to the Guidelines for full-service/inclusive schools issued in 2009, and by discussing a…

  9. The Inclusion Facilitator's Guide

    ERIC Educational Resources Information Center

    Jorgensen, Cheryl M.; Schuh, Mary C.; Nisbet, Jan

    2005-01-01

    Inclusion facilitators are educators who do more than teach children with disabilities--they advocate for change in schools and communities, sparking a passion for inclusion in teachers, administrators, and families and giving them the practical guidance they need to make it work. This is an essential new role in today's schools, and this guide…

  10. Understanding Inclusion in Cyprus

    ERIC Educational Resources Information Center

    Mamas, Christoforos

    2013-01-01

    This paper provides a framework for understanding inclusion in Cyprus. The evidence base is the result of a six-month qualitative research study in five Cypriot mainstream primary schools. Despite the rhetoric in favour of inclusion, it seems that the Cypriot educational system is still highly segregating in its philosophy and does not fully…

  11. Biodegradable polyurethane ureas with variable polyester or polycarbonate soft segments: effects of crystallinity, molecular weight, and composition on mechanical properties.

    PubMed

    Ma, Zuwei; Hong, Yi; Nelson, Devin M; Pichamuthu, Joseph E; Leeson, Cory E; Wagner, William R

    2011-09-12

    Biodegradable polyurethane urea (PUU) elastomers are ideal candidates for fabricating tissue engineering scaffolds with mechanical properties akin to strong and resilient soft tissues. PUU with a crystalline poly(ε-caprolactone) (PCL) macrodiol soft segment (SS) showed good elasticity and resilience at small strains (<50%) but showed poor resilience under large strains because of stress-induced crystallization of the PCL segments, with a permanent set of 677 ± 30% after tensile failure. To obtain softer and more resilient PUUs, we used noncrystalline poly(trimethylene carbonate) (PTMC) or poly(δ-valerolactone-co-ε-caprolactone) (PVLCL) macrodiols of different molecular weights as SSs that were reacted with 1,4-diisocyanatobutane and chain extended with 1,4-diaminobutane. Mechanical properties of the PUUs were characterized by tensile testing with static or cyclic loading and dynamic mechanical analysis. All of the PUUs synthesized showed large elongations at break (800-1400%) and high tensile strength (30-60 MPa). PUUs with noncrystalline SSs all showed improved elasticity and resilience relative to the crystalline PCL-based PUU, especially for the PUUs with high molecular weight SSs (PTMC 5400 M(n) and PVLCL 6000 M(n)), of which the permanent deformation after tensile failure was only 12 ± 7 and 39 ± 4%, respectively. The SS molecular weight also influenced the tensile modulus in an inverse fashion. Accelerated degradation studies in PBS containing 100 U/mL lipase showed significantly greater mass loss for the two polyester-based PUUs versus the polycarbonate-based PUU and for PVLCL versus PCL polyester PUUs. Basic cytocompatibility was demonstrated with primary vascular smooth muscle cell culture. The synthesized families of PUUs showed variable elastomeric behavior that could be explained in terms of the underlying molecular design and crystalline behavior. Depending on the application target of interest, these materials may provide options or guidance for

  12. Optimization of inclusive fitness.

    PubMed

    Grafen, Alan

    2006-02-07

    The first fully explicit argument is given that broadly supports a widespread belief among whole-organism biologists that natural selection tends to lead to organisms acting as if maximizing their inclusive fitness. The use of optimization programs permits a clear statement of what this belief should be understood to mean, in contradistinction to the common mathematical presumption that it should be formalized as some kind of Lyapunov or even potential function. The argument reveals new details and uncovers latent assumptions. A very general genetic architecture is allowed, and there is arbitrary uncertainty. However, frequency dependence of fitnesses is not permitted. The logic of inclusive fitness immediately draws together various kinds of intra-genomic conflict, and the concept of 'p-family' is introduced. Inclusive fitness is thus incorporated into the formal Darwinism project, which aims to link the mathematics of motion (difference and differential equations) used to describe gene frequency trajectories with the mathematics of optimization used to describe purpose and design. Important questions remain to be answered in the fundamental theory of inclusive fitness.

  13. When social inclusion is not enough: Implicit expectations of extreme inclusion in borderline personality disorder.

    PubMed

    De Panfilis, Chiara; Riva, Paolo; Preti, Emanuele; Cabrino, Chiara; Marchesi, Carlo

    2015-10-01

    Increasing evidence suggests that individuals with borderline personality disorder (BPD) might feel rejected even when socially included by others. A psychological mechanism accounting for this response bias could be that objective social inclusion violates BPD patients' underlying implicit needs of "extreme" inclusion. Thus, this study investigated whether, during interpersonal exchanges, BPD patients report more rejection-related negative emotions and less feelings of social connection than controls unless they are faced with conditions of extreme social inclusion. Sixty-one BPD patients and 61 healthy controls completed a modified Cyberball paradigm. They were randomly assigned to a condition of ostracism, social inclusion, or overinclusion (a proxy for extreme social inclusion). They then rated their emotional states and feelings of social connection immediately and 20 min after the game. BPD patients reported greater levels of negative emotions than controls in the ostracism and the inclusion conditions, but not when overincluded. Furthermore, only for BPD participants was overinclusion associated with experiencing less negative emotions than the ostracism condition. However, BPD patients reported lower feelings of social connection than controls in any experimental situation. Thus, in BPD, a laboratory condition of "overinclusion" is associated with a reduction of negative emotions to levels comparable to those of control participants, but not with similar degrees of social connection. These results suggest that for BPD patients, even "including contexts" activate feelings of rejection. Their implicit expectations of idealized interpersonal inclusion may nullify the opportunity of experiencing "real" social connection and explain their distorted subjective experiences of rejection. (c) 2015 APA, all rights reserved).

  14. Inclusion 101: How To Teach All Learners.

    ERIC Educational Resources Information Center

    Bauer, Anne M.; Shea, Thomas M.

    This book is designed to help educators provide effective instruction to students with disabilities in inclusive classrooms. Chapters address: (1) the concepts of inclusive society, schools, classrooms and services; (2) legal foundations for inclusion and government support for education; (3) the qualities of inclusive schools and classrooms; (4)…

  15. The Inclusion of Inclusive Education in International Development: Lessons from Papua New Guinea

    ERIC Educational Resources Information Center

    Le Fanu, Guy

    2013-01-01

    A new "inclusive" curriculum has been introduced in Papua New Guinea, with significant levels of support from a bilateral development agency. The curriculum is inclusive in the sense that it is designed to meet the diverse, complex, and ever-changing needs of students. Research indicates the curriculum has been shaped by various…

  16. The Inclusion Puzzle: A Case Study of Inclusion in a Rural Elementary School

    ERIC Educational Resources Information Center

    Arnold, Linda N.

    2010-01-01

    Inclusion of special education students in general education classrooms has come to general acceptance by educators as one option in the continuum of special education service delivery. Another view of inclusion is the ideal of providing for all the varied individual needs of a diverse population of students: learning needs, physical needs,…

  17. Bacterial community composition characterization of a lead-contaminated Microcoleus sp. consortium.

    PubMed

    Giloteaux, Ludovic; Solé, Antoni; Esteve, Isabel; Duran, Robert

    2011-08-01

    A Microcoleus sp. consortium, obtained from the Ebro delta microbial mat, was maintained under different conditions including uncontaminated, lead-contaminated, and acidic conditions. Terminal restriction fragment length polymorphism and 16S rRNA gene library analyses were performed in order to determine the effect of lead and culture conditions on the Microcoleus sp. consortium. The bacterial composition inside the consortium revealed low diversity and the presence of specific terminal-restriction fragments under lead conditions. 16S rRNA gene library analyses showed that members of the consortium were affiliated to the Alpha, Beta, and Gammaproteobacteria and Cyanobacteria. Sequences closely related to Achromobacter spp., Alcaligenes faecalis, and Thiobacillus species were exclusively found under lead conditions while sequences related to Geitlerinema sp., a cyanobacterium belonging to the Oscillatoriales, were not found in presence of lead. This result showed a strong lead selection of the bacterial members present in the Microcoleus sp. consortium. Several of the 16S rRNA sequences were affiliated to nitrogen-fixing microorganisms including members of the Rhizobiaceae and the Sphingomonadaceae. Additionally, confocal laser scanning microscopy and scanning and transmission electron microscopy showed that under lead-contaminated condition Microcoleus sp. cells were grouped and the number of electrodense intracytoplasmic inclusions was increased.

  18. The diagnostic value of cerebrospinal fluid lactate for post-neurosurgical bacterial meningitis: a meta-analysis.

    PubMed

    Xiao, Xiong; Zhang, Yang; Zhang, Liwei; Kang, Peng; Ji, Nan

    2016-09-13

    Bacterial meningitis is not rare in post-neurosurgical patients. If patients are not treated promptly, the mortality rate can reach 20 to 50 %. The concentration of cerebrospinal fluid (CSF) lactate has been reported to be helpful in the diagnosis of bacterial meningitis; however, no systematic evaluations have investigated CSF from a postoperative perspective. In this study, we performed a systematic evaluation and meta-analysis of the efficacy of using CSF lactate concentrations in the diagnosis of post-neurosurgical bacterial meningitis. We retrieved studies that investigated the diagnostic value of CSF lactate for the diagnosis of post-neurosurgical bacterial meningitis by searching PubMed, EBSCO, the Cochrane Library and ClinicalTrials.gov. All these databases were searched from inception to November 2015. We used Quality Assessment of Diagnostic Accuracy Studies (QUADAS), a tool for the quality assessment of diagnostic accuracy, to evaluate the quality of the included studies. The Meta-DiSc 1.4 and Review Manager 5.3 software programs were used to analyze the included studies. Forest plots and summary receiver operating characteristics (SROC) curves were also drawn. Five studies, involving a total of 404 post-neurosurgical patients, were selected from 1,672 articles according to the inclusion criteria. The quality of the five included studies was assessed using QUADAS, and the related results are presented in tables. The meta-analysis revealed the following diagnostic values regarding CSF lactate for post-neurosurgical bacterial meningitis: a pooled sensitivity of 0.92 (95 % CI 0.85-0.96), a pooled specificity of 0.88 (95 % CI 0.84-0.92 with significant heterogeneity), a diagnostic odds ratio of 83.09 (95 % CI 36.83-187.46), an area under the curve (AUCSROC) of 0.9601, an SE(AUC) of 0.0122, a Q* of 0.9046 and an SE(Q*) of 0.0179. The meta-analysis indicated that the CSF lactate concentration has relatively high sensitivity and specificity for the

  19. Human β-defensin 3 increases the TLR9-dependent response to bacterial DNA.

    PubMed

    McGlasson, Sarah L; Semple, Fiona; MacPherson, Heather; Gray, Mohini; Davidson, Donald J; Dorin, Julia R

    2017-04-01

    Human β-defensin 3 (hBD3) is a cationic antimicrobial peptide with potent bactericidal activity in vitro. HBD3 is produced in response to pathogen challenge and can modulate immune responses. The amplified recognition of self-DNA by human plasmacytoid dendritic cells has been previously reported, but we show here that hBD3 preferentially enhances the response to bacterial DNA in mouse Flt-3 induced dendritic cells (FLDCs) and in human peripheral blood mononuclear cells. We show the effect is mediated through TLR9 and although hBD3 significantly increases the cellular uptake of both E. coli and self-DNA in mouse FLDCs, only the response to bacterial DNA is enhanced. Liposome transfection also increases uptake of bacterial DNA and amplifies the TLR9-dependent response. In contrast to hBD3, lipofection of self-DNA enhances inflammatory signaling, but the response is predominantly TLR9-independent. Together, these data show that hBD3 has a role in the innate immune-mediated response to pathogen DNA, increasing inflammatory signaling and promoting activation of the adaptive immune system via antigen presenting cells including dendritic cells. Therefore, our data identify an additional immunomodulatory role for this copy-number variable defensin, of relevance to host defence against infection and indicate a potential for the inclusion of HBD3 in pathogen DNA-based vaccines. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Inclusion evolution in molten and solidifying steel

    NASA Astrophysics Data System (ADS)

    Wang, Yan

    Cleanliness, with respect to impurities and nonmetallic inclusions in the melt, is an important issue in steel production. The commercial interest in controlling steel cleanliness has been growing rapidly, because clean steel exhibits a highly attractive combination of corrosion resistance, good formability, pleasing appearance, and a wide range of strength levels. In order to satisfy the requirements for the degree of cleanliness in steel, controlling the size distribution, chemistry and shape of inclusions are of great importance in the steelmaking process. A knowledge of the formation of nonmetallic inclusions and their chemical and morphological evolution during the steelmaking and casting process is necessary in order to minimize the inclusion size and also try to promote potentially beneficial properties of inclusions, such as grain-refining. In this research, the evolution of inclusions in molten and solidifying steels was investigated through in-situ observations using a high temperature Confocal Scanning Laser Microscope (CSLM). The study focused on solid Al2O3 and liquid Al 2O3-CaO inclusions on low carbon steel melt surfaces. Firstly, the agglomeration and clustering of inclusions on steel surfaces were quantified and compared to predictions according to capillary depression driven attraction forces. A strong agglomeration was observed between the solid Al2O33 particle pairs. However, the liquid Al 2O3-CaO inclusions were not prone to agglomeration due to their lens-like morphology, which causes the absence of capillary force. Secondly, the pushing vs. engulfment and entrapment of both liquid Al 2O3-CaO and solid Al2O3 inclusions by advancing planar and cellular delta-ferrite solidification fronts was studied and compared to model predictions based on the force balances acting on the inclusions at the solid/melt interface. The critical velocity, above which the inclusions get engulfed, was observed to be slower at the cellular front than at the planar

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