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Sample records for polyethylene glycol-modified proteins

  1. Cell separation by immunoaffinity partitioning with polyethylene glycol-modified Protein A in aqueous polymer two-phase systems

    NASA Technical Reports Server (NTRS)

    Karr, Laurel J.; Van Alstine, James M.; Snyder, Robert S.; Shafer, Steven G.; Harris, J. Milton

    1988-01-01

    Previous work has shown that polyethylene glycol (PEG)-bound antibodies can be used as affinity ligands in PEG-dextran two-phase systems to provide selective partitioning of cells to the PEG-rich phase. In the present work it is shown that immunoaffinity partitioning can be simplified by use of PEG-modified Protein A which complexes with unmodified antibody and cells and shifts their partitioning into the PEG-rich phase, thus eliminating the need to prepare a PEG-modified antibody for each cell type. In addition, the paper provides a more rigorous test of the original technique with PEG-bound antibodies by showing that it is effective at shifting the partitioning of either cell type of a mixture of two cell populations.

  2. Expert Review Poly(ethylene glycol)-modified Nanocarriers for Tumor-targeted

    E-print Network

    Sridhar, Srinivas

    Expert Review Poly(ethylene glycol)-modified Nanocarriers for Tumor-targeted and Intracellular, prolong circulation time, minimize non-specific uptake, and allow for specific tumor-targeting through for incorporation of active targeting ligands, thereby providing the drug and gene carriers with specific tumor

  3. Pharmacokinetics and microdistribution of polyethylene glycol-modified humanized A33 antibody targeting colon cancer xenografts.

    PubMed

    Deckert, P M; Jungbluth, A; Montalto, N; Clark, M A; Finn, R D; Williams, C; Richards, E C; Panageas, K S; Old, L J; Welt, S

    2000-08-01

    Therapeutic proteins have been conjugated with polyethylene glycol (PEGylation) to reduce immunogenicity and enhance circulating dose. Here we have investigated the effect of PEGylation on immunogenicity, pharmacokinetics, and histologic microdistribution of tumor-targeting antibodies with humanized A33 antibody (huA33) as a model system. Conjugation of huA33 with methoxy-PEG of M(r) 5,000 (32%-34% of primary amines modified) or M(r) 20,000 (16%-18% modification) preserved >50% of native huA33 binding to SW1222 colon cancer cells. In mice, both PEGylated forms cleared from serum moderately slower than native huA33. After repeated immunization with PEG-huA33, antiantibody titers in immunocompetent mice were <5% of those in huA33-treated controls. Both PEG-huA33 forms reached approx. 75% of the maximum tumor dose of huA33 in SW1222-xenografted mice, but their tumor:blood ratios were considerably reduced. To demonstrate immunologic specificity of PEG-huA33 targeting in SW1222 tumor-bearing mice, antigenic sites were presaturated by injecting excess native huA33. This reduced subsequent uptake of PEG-huA33 by up to 80%, whereas presaturation with hu3S193 control antibody had no significant effect. To assess the microdistribution of antibody uptake in the same xenograft model, tumor tissue resected at different time points after antibody administration was examined for human IgG by immunohistochemistry. Both PEG preparations achieved the same peak staining intensity and homogeneity as native huA33 with a delay of several hours. Given the measured reduction in immunoreactivity in vitro, these results demonstrate that the tumor targeting potential of huA33 in vivo is preserved at PEGylation levels sufficient to suppress immunogenicity. PMID:10897044

  4. An ultrahigh dielectric constant composite based on polyvinylidene fluoride and polyethylene glycol modified ferroferric oxide

    NASA Astrophysics Data System (ADS)

    Zhu, Jiujun; Li, Weiping; Huo, Xiaoyun; Li, Lili; Li, Ya; Luo, Laihui; Zhu, Yuejin

    2015-09-01

    To improve the compatibility between a filler and polymer matrix, a polyethylene glycol (PEG) surface modifier was used for modification in the polyvinylidene fluoride (PVDF) and ferroferric oxide (Fe3O4) composites. It is found that the PEG-modified Fe3O4 and PVDF composites have a much higher dielectric constant and better suppressed dielectric loss than the other similar percolative systems. The maximum of the dielectric constant can be up to 63?000 while the dielectric loss is controlled below 4.5. Finally, the microscopic reasons for this improvement are presented. It is helpful to understand the influence of surface modification agents on the interfaces between the filler and matrix.

  5. Polyethylene-Glycol-Modified Single-Walled Carbon Nanotubes for Intra-Articular Delivery to Chondrocytes

    PubMed Central

    Sacchetti, Cristiano; Liu-Bryan, Ru; Magrini, Andrea; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo

    2015-01-01

    Osteoarthritis (OA) is a common and debilitating degenerative disease of articular joints for which no disease-modifying medical therapy is currently available. Inefficient delivery of pharmacologic agents into cartilage-resident chondrocytes after systemic administration has been a limitation to the development of anti-OA medications. Direct intra-articular injection enables delivery of high concentrations of agents in close proximity to chondrocytes; however, the efficacy of this approach is limited by the fast clearance of small molecules and biomacromolecules after injection into the synovial cavity. Coupling of pharmacologic agents with drug delivery systems able to enhance their residence time and cartilage penetration can enhance the effectiveness of intra-articularly injected anti-OA medications. Herein we describe an efficient intra-articular delivery nanosystem based on single-walled carbon nanotubes (SWCNTs) modified with polyethylene glycol (PEG) chains (PEG-SWCNTs). We show that PEG-SWCNTs are capable to persist in the joint cavity for a prolonged time, enter the cartilage matrix, and deliver gene inhibitors into chondrocytes of both healthy and OA mice. PEG-SWCNT nanoparticles did not elicit systemic or local side effects. Our data suggest that PEG-SWCNTs represent a biocompatible and effective nanocarrier for intra-articular delivery of agents to chondrocytes. PMID:25415768

  6. Polyethylene glycol-modified dendrimer-entrapped gold nanoparticles enhance CT imaging of blood pool in atherosclerotic mice

    PubMed Central

    2014-01-01

    We report a new use of dendrimer-entrapped gold nanoparticles (Au DENPs) modified by polyethylene glycol (PEG) with good biocompatibility for in vitro and in vivo imaging of atherosclerotic mice by computed tomography (CT). In this study, Au DENPs were synthesized using poly(amidoamine) (PAMAM) dendrimers of generation 5 (G5.NH2) modified by PEG monomethyl ether (G5.NH2-mPEG20) as templates. In vitro cytotoxicity and flow cytometry assays show that the formed PEGylated Au DENPs have good biocompatibility and are non-cytotoxic at the Au concentration up to 300 ?M. Silver staining and transmission electron microscopy (TEM) further confirm that the Au DENPs are able to be uptaken by macrophages and are located dominantly in the lysosomes of the cells. Importantly, the formed PEGylated Au DENPs are able to be used for CT imaging of murine macrophages in vitro and macrophages in atherosclerotic mice in vivo using apolipoprotein-E-gene-deficient mice as a model. These findings suggest that the formed PEGylated Au DENPs are a promising contrast agent for CT imaging of atherosclerosis. PMID:25288918

  7. Poly(ethylene glycol)-Modified Ligninase Enhances Pentachlorophenol

    E-print Network

    Wang, Ping

    -miscible solvent. The modified enzyme retained 100% of its activity in aqueous solutions and showed enhanced tolerance against the organic solvent. The activity of the modified enzyme was found to be over twice- hanced substrate solubility and the increased activity of the modified enzyme, the catalytic efficiency

  8. Protein diffusion in photopolymerized poly(ethylene glycol) hydrogel networks.

    PubMed

    Engberg, Kristin; Frank, Curtis W

    2011-10-01

    In this study, protein diffusion through swollen hydrogel networks prepared from end-linked poly(ethylene glycol)-diacrylate (PEG-DA) was investigated. Hydrogels were prepared via photopolymerization from PEG-DA macromonomer solutions of two molecular weights, 4600 Da and 8000 Da, with three initial solid contents: 20, 33 and 50 wt/wt% PEG. Diffusion coefficients for myoglobin traveling across the hydrogel membrane were determined for all PEG network compositions. The diffusion coefficient depended on PEG molecular weight and initial solid content, with the slowest diffusion occurring through lower molecular weight, high-solid-content networks (D(gel) = 0.16 ± 0.02 × 10(-8) cm(2) s(-1)) and the fastest diffusion occurring through higher molecular weight, low-solid-content networks (D(gel) = 11.05 ± 0.43 × 10(-8) cm(2) s(-1)). Myoglobin diffusion coefficients increased linearly with the increase of water content within the hydrogels. The permeability of three larger model proteins (horseradish peroxidase, bovine serum albumin and immunoglobulin G) through PEG(8000) hydrogel membranes was also examined, with the observation that globular molecules as large as 10.7 nm in hydrodynamic diameter can diffuse through the PEG network. Protein diffusion coefficients within the PEG hydrogels ranged from one to two orders of magnitude lower than the diffusion coefficients in free water. Network defects were determined to be a significant contributing factor to the observed protein diffusion. PMID:21873762

  9. Plasma proteins adsorption mechanism on polyethylene-grafted poly(ethylene glycol) surface by quartz crystal microbalance with dissipation.

    PubMed

    Jin, Jing; Jiang, Wei; Yin, Jinghua; Ji, Xiangling; Stagnaro, Paola

    2013-06-01

    Protein adsorption has a vital role in biomaterial surface science because it is directly related to the hemocompatibility of blood-contacting materials. In this study, monomethoxy poly(ethylene glycol) (mPEG) with two different molecular weights was grafted on polyethylene as a model to elucidate the adsorption mechanisms of plasma protein through quartz crystal microbalance with dissipation (QCM-D). Combined with data from platelet adhesion, whole blood clotting time, and hemolysis rate, the blood compatibility of PE-g-mPEG film was found to have significantly improved. Two adsorption schemes were developed for real-time monitoring of protein adsorption. Results showed that the preadsorbed bovine serum albumin (BSA) on the surfaces of PE-g-mPEG films could effectively inhibit subsequent adsorption of fibrinogen (Fib). Nonspecific protein adsorption of BSA was determined by surface coverage, not by the chain length of PEG. Dense PEG brush could release more trapped water molecules to resist BSA adsorption. Moreover, the preadsorbed Fib could be gradually displaced by high-concentration BSA. However, the adsorption and displacement of Fib was determined by surface hydrophilicity. PMID:23659226

  10. Comparison between Protein-Polyethylene Glycol (PEG) Interactions and the Effect of PEG on Protein-Protein Interactions Using the Liquid-Liquid Phase Transition

    E-print Network

    Benedek, George B.

    Comparison between Protein-Polyethylene Glycol (PEG) Interactions and the Effect of PEG on Protein-ProteinVember 18, 2006 Phase transitions of protein aqueous solutions are important for protein crystallization and biomaterials science in general. One source of thermodynamic complexity in protein solutions and their phase

  11. Influence of Surface Charge and Polymer Coating on Internalization and Biodistribution of Polyethylene Glycol-Modified Iron Oxide Nanoparticles.

    PubMed

    Maurizi, Lionel; Papa, Anne-Laure; Dumont, Laure; Bouyer, Frédéric; Walker, Paul; Vandroux, David; Millot, Nadine

    2015-01-01

    The aim of this study was to investigate the influence of the surface charge and coating of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on their in vitro and in vivo behaviors. Neutral and negatively-charged PEG-based SPIONs were synthesized and compared to Resovist, a carboxydextran-based SPION currently used in clinics. Their cytotoxicity, cell internalization, and potential as contrast agents for magnetic resonance imaging were assessed. Neutral pegylated SPIONs were internalized less readily by the reticuloendothelial system and showed a lower uptake by the liver, compared to negatively-charged SPIONs (with carboxydextran and PEG). These results suggested that the charge of functionalized SPIONs was more relevant for their biological interactions than the nature of their coating. PMID:26301306

  12. Interfacial Protein-Protein Associations

    PubMed Central

    Langdon, Blake B.; Kastantin, Mark; Walder, Robert; Schwartz, Daniel K.

    2014-01-01

    While traditional models of protein adsorption focus primarily on direct protein-surface interactions, recent findings suggest that protein-protein interactions may play a central role. Using high-throughput intermolecular resonance energy transfer (RET) tracking, we directly observed dynamic, protein-protein associations of bovine serum albumin on poly(ethylene glycol) modified surfaces. The associations were heterogeneous and reversible, and associating molecules resided on the surface for longer times. The appearance of three distinct RET states suggested a spatially heterogeneous surface – with areas of high protein density (i.e. strongly-interacting clusters) coexisting with mobile monomers. Distinct association states exhibited characteristic behavior, i.e. partial-RET (monomer-monomer) associations were shorter-lived than complete-RET (protein-cluster) associations. While the fractional surface area covered by regions with high protein density (i.e. clusters) increased with increasing concentration, the distribution of contact times between monomers and clusters was independent of solution concentration, suggesting that associations were a local phenomenon, and independent of the global surface coverage. PMID:24274729

  13. Monoliths from poly(ethylene glycol) diacrylate and dimethacrylate for capillary hydrophobic interaction chromatography of proteins.

    PubMed

    Li, Yuanyuan; Tolley, H Dennis; Lee, Milton L

    2010-07-23

    Rigid monoliths were synthesized solely from poly(ethylene glycol) diacrylates (PEGDA) or poly(ethylene glycol) dimethacrylates (PEGDMA) containing different ethylene glycol chain lengths by one-step UV-initiated polymerization. Methanol/ethyl ether and cyclohexanol/decanol were used as bi-porogen mixtures for the PEGDA and PEGDMA monoliths, respectively. Effects of PEG chain length, bi-porogen ratio and reaction temperature on monolith morphology and back pressure were investigated. For tri- and tetra-ethylene glycol diacrylates (i.e., PEGDA 258 and PEGDA 302), most combinations of methanol and ethyl ether were effective in forming monoliths, while for diacrylates containing longer chain lengths (i.e., PEGDA 575 and PEGDA 700), polymerization became more sensitive to the bi-porogen ratio. A similar tendency was also observed for PEGDMA monomers. Polymerization of monoliths was conducted at approximately 0 degrees C and room temperature, which produced significant differences in monolith morphology and permeability. Monoliths prepared from PEGDA 258 were found to provide the best chromatographic performance with respect to peak capacity and resolution in hydrophobic interaction chromatography (HIC). Detailed study of these monoliths demonstrated that chromatographic performance was not affected by changing the ratios of the two porogens, but resulted in almost identical retention times and comparable peak capacities. An optimized PEGDA 258 monolithic column was able to separate proteins using a 20-min elution gradient with a peak capacity of 62. Mass recoveries for test proteins were found to be greater than 90, indicating its excellent biocompatibility. All monoliths demonstrated nearly no swelling or shrinking in different polarity solvents, and most of them could be stored dry, indicating excellent stability due to their highly crosslinked networks. The preparation of these in situ polymerized single-monomer monolithic columns was highly reproducible. The relative standard deviation (RSD) values based on retention times of retained proteins were all within 2.2%, and in most cases, less than 1.2%. The RSD values based on peak areas were within 9.5%, and in most cases, less than 7.0%. The single-monomer synthesis approach clearly improves column-to-column reproducibility. PMID:20576269

  14. Protein and cell patterning in closed polymer channels by photoimmobilizing proteins on photografted poly(ethylene glycol) diacrylate

    PubMed Central

    Larsen, Esben Kjær Unmack; Larsen, Niels B.

    2014-01-01

    Definable surface chemistry is essential for many applications of microfluidic polymer systems. However, small cross-section channels with a high surface to volume ratio enhance passive adsorption of molecules that depletes active molecules in solution and contaminates the channel surface. Here, we present a one-step photochemical process to coat the inner surfaces of closed microfluidic channels with a nanometer thick layer of poly(ethylene glycol) (PEG), well known to strongly reduce non-specific adsorption, using only commercially available reagents in an aqueous environment. The coating consists of PEG diacrylate (PEGDA) covalently grafted to polymer surfaces via UV light activation of the water soluble photoinitiator benzoyl benzylamine, a benzophenone derivative. The PEGDA coating was shown to efficiently limit the adsorption of antibodies and other proteins to <5% of the adsorbed amount on uncoated polymer surfaces. The coating could also efficiently suppress the adhesion of mammalian cells as demonstrated using the HT-29 cancer cell line. In a subsequent equivalent process step, protein in aqueous solution could be anchored onto the PEGDA coating in spatially defined patterns with a resolution of <15??m using an inverted microscope as a projection lithography system. Surface patterns of the cell binding protein fibronectin were photochemically defined inside a closed microfluidic device that was initially homogeneously coated by PEGDA. The resulting fibronectin patterns were shown to greatly improve cell adhesion compared to unexposed areas. This method opens for easy surface modification of closed microfluidic systems through combining a low protein binding PEG-based coating with spatially defined protein patterns of interest. PMID:25587375

  15. Complete identification of proteins responsible for human blood plasma fouling on poly(ethylene glycol)-based surfaces.

    PubMed

    Riedel, Tomáš; Riedelová-Reicheltová, Zuzana; Májek, Pavel; Rodriguez-Emmenegger, César; Houska, Milan; Dyr, Jan E; Brynda, Eduard

    2013-03-12

    The resistance of poly(ethylene glycol) (PEG) against protein adsorption is crucial and has been widely utilized in various biomedical applications. In this work, the complete protein composition of biofilms deposited on PEG-based surfaces from human blood plasma (BP) was identified for the first time using nanoLC-MS/MS, a powerful tool in protein analysis. The mass of deposited BP and the number of different proteins contained in the deposits on individual surfaces decreased in the order of self-assembling monolayers of oligo(ethylene glycol) alkanethiolates (SAM) > poly(ethylene glycol) end-grafted onto a SAM > poly(oligo(ethylene glycol) methacrylate) brushes prepared by surface initiated polymerization (poly(OEGMA)). The BP deposit on the poly(OEGMA) surface was composed only of apolipoprotein A-I, apolipoprotein B-100, complement C3, complement C4-A, complement C4-B, histidine-rich glycoprotein, Ig mu chain C region, fibrinogen (Fbg), and serum albumin (HSA). The total resistance of the surface to the Fbg and HSA adsorption from single protein solutions suggested that their deposition from BP was mediated by some of the other proteins. Current theories of protein resistance are not sufficient to explain the observed plasma fouling. The research focused on the identified proteins, and the experimental approach used in this work can provide the basis for the understanding and rational design of plasma-resistant surfaces. PMID:23391268

  16. Wear properties of polyethylene-metal and polyethylene-ceramic bearings for hip joint replacements: The effect of temperature and protein precipitation in hip simulator tests

    NASA Astrophysics Data System (ADS)

    Liao, Yen-Shuo

    Ultra-high-molecular weight polyethylene (PE) cups bearing against metal or ceramic balls are the most commonly used combinations of materials for human hip joint replacements. The wear properties of these materials are typically evaluated in the laboratory using hip joint wear simulators, while lubricated with bovine serum. A previous test evaluating the PE cups against cobalt-chrome (CoCr), zirconia (Zr) and alumina balls demonstrated the sensitivity of serum proteins to elevated temperature; especially for Zr/PE, which showed the highest protein precipitation and bulk lubricant temperature but the lowest cup wear. In the present investigation, a temperature control system was used on a hip simulator to systematically evaluate the relationship between temperature and denaturation of the serum proteins which, in turn, affects the friction and wear properties of the prosthetic materials being tested. In order to control protein precipitation, the interface was temperature reduced by circulating coolant at 4°C through the center of the CoCr or Zr balls during a wear test. With cooling, protein assay of the serum showed 66% and 50% reductions in protein precipitation with the CoCr and Zr balls, respectively. The wear rate of the PE cups against the CoCr balls decreased by an average of 44%, whereas two of the three PE cups running against Zr balls exhibited slight increases in their wear rates, and the third showed a two fold increase. Under scanning electron microscopy, there were marked differences in the worn surfaces of the cups for the various conditions, and differences in the morphology of the PE wear debris recovered from the serum. For example, granular particles predominated without cooling, whereas fibrous particles predominated with cooling. Since particles generated in vivo (i.e., retrieved from periprosthetic tissues) typically show approximately equal proportions of granules and fibrils, the use of an intermediate coolant temperature might provide wear in the simulator closer to that occurring with these materials in vivo. These results demonstrated the complex interaction of the variables affecting wear in the hip simulator system that should be taken into account, for example, in the development of international standard procedures.

  17. Protein adsorption and cell adhesion on nanoscale bioactive coatings formed from poly(ethylene glycol) and albumin microgels

    PubMed Central

    Scott, Evan A.; Nichols, Michael D.; Cordova, Lee H.; George, Brandon J.; Jun, Young-Shin; Elbert, Donald L.

    2008-01-01

    Late-term thrombosis on drug-eluting stents is an emerging problem that might be addressed using extremely thin, biologically-active hydrogel coatings. We report a dip-coating strategy to covalently link poly(ethylene glycol) (PEG) to substrates, producing coatings with protein-resistant layer with a thickness of approximately 75 nm. Atomic force microscopy in buffered water revealed the presence of coalesced spheres of various sizes but with diameters less than about 100 nm. Microgel-coated glass or poly(ethylene terephthalate) exhibited reduced protein adsorption and cell adhesion. Cellular interactions with the surface could be controlled by using different proteins to cap unreacted vinylsulfone groups within the coating. PMID:18771802

  18. Steric exclusion is the principal source of the preferential hydration of proteins in the presence of polyethylene glycols.

    PubMed Central

    Bhat, R.; Timasheff, S. N.

    1992-01-01

    The preferential interactions of bovine serum albumin, lysozyme, chymotrypsinogen, ribonuclease A, and beta-lactoglobulin with polyethylene glycols (PEGs) of molecular weight 200-6,000 have been measured by dialysis equilibrium coupled with high precision densimetry. All the proteins were found to be preferentially hydrated in all the PEGs, and the magnitude of the preferential hydration increased with increasing PEG size for each protein. The change in the chemical potentials of the proteins with the addition of the PEGs had highly positive values, indicating a strong thermodynamic destabilization of the system by the PEGs. A viscosity study of the PEGs showed them to be randomly coiled polymers, as their radii of gyration were related to the molecular weight by Rg = aM0.55. The thickness of the effective shell impenetrable to PEG around protein molecules, calculated from the preferential hydration, was found to vary with PEG molecular weight in similar fashion as the PEG radius of gyration, supporting the proposal (Arakawa, T. & Timasheff, S.N., 1985a, Biochemistry 24, 6756-6762) that the preferential exclusion of PEGs from proteins is due principally to the steric exclusion of PEG from the protein domain, although favorable interactions with protein surface residues, in particular nonpolar ones, may compete with the exclusion. These thermodynamically unfavorable preferential exclusion interactions lead to the action of PEGs as precipitants, although they may destabilize protein structure at higher temperatures. PMID:1304392

  19. Improving biocompatibility by controlling protein adsorption: Modification and design of biomaterials using poly(ethylene glycol) microgels and microspheres

    NASA Astrophysics Data System (ADS)

    Scott, Evan Alexander

    2009-12-01

    Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material's surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic surfaces. The objective of this thesis is to improve the design of biomaterials through the analysis and control of adsorbing protein layers. This goal is approached through three separate strategies. First, a proteomics-based methodology is presented for the assessment of protein conformation at the residue level after adsorption to biomaterial surfaces. A quantitative mass spectrometric technique is additionally suggested for the identification and quantification of proteins within adsorbed protein layers. Second, a method is described for the covalent attachment of poly(ethylene glycol) (PEG)-based hydrogel coatings onto biomaterials surfaces for the minimization of protein adsorption. The coatings are applied using partially crosslinked PEG solutions containing polymer and protein oligomers and microgels that can be designed to control cell adhesion. Finally, a modular strategy is proposed for the assembly of bioactive PEG-based hydrogel scaffolds. This was accomplished using novel PEG microspheres with diverse characteristics that individually contribute to the ability of the scaffold to direct cellular infiltration. The methodologies proposed by this thesis contribute to the recent shift in biomaterials and tissue engineering strategies towards directed cellular responses at the molecular level.

  20. Effects of one-seed juniper and polyethylene glycol on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein and tannins.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the effect of polyethylene glycol (PEG) on juniper and total intake, rumen fermentation, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and basal diets containing 10% quebracho tannins with no protein supplement (Control; 5% CP) or high rumen degradable (RDP 15% CP) or u...

  1. Polyethylenimine modified poly(ethylene terephthalate) capillary channeled-polymer fibers for anion exchange chromatography of proteins.

    PubMed

    Jiang, Liuwei; Jin, Yi; Marcus, R Kenneth

    2015-09-01

    Native poly(ethylene terephthalate) (PET) capillary-channeled polymer (C-CP) fibers have been previously studied as stationary phases for reversed phase and affinity protein separations. In this study, surface modified PET C-CP fibers were evaluated for the anion exchange separation of proteins. The native PET C-CP fibers were aminated using polyethylenimine (PEI) followed by a 1,4-butanediol diglycidyl ether (BUDGE) cross-linking step. Subsequent PEI/BUDGE treatments can be employed to further develop the polyamine layer on the fiber surfaces. The PEI densities of the modified fibers were quantified through the ninhydrin reaction, yielding values of 0.43-0.89?molg(-1). The surface modification impact on column permeability was found to be 0.66×10(-11) to 1.33×10(-11)m(2), depending on the modification time and conditions. The dynamic binding capacities of the modified fiber media were determined to be 1.99-8.54mgmL(-1) bed volume, at linear velocities of 88-438cmmin(-1) using bovine serum albumin as the model protein. It was found that increasing the mobile phase linear velocity (up to 438cmmin(-1)) had no effect on the separation quality for a synthetic protein mixture, reflecting the lack of van Deemter C-term effects for the C-CP fiber phase. The low-cost, easy modification method and the capability of fast protein separation illustrate great potential in the use of PEI/BUDGE-modified PET C-CP fibers for high-throughput protein separation and downstream processing. PMID:26253835

  2. Use of Cross-Linked Poly(ethylene glycol)-Based Hydrogels for Protein Crystallization

    PubMed Central

    2015-01-01

    Poly(ethylene glycol) (PEG) hydrogels are highly biocompatible materials extensively used for biomedical and pharmaceutical applications, controlled drug release, and tissue engineering. In this work, PEG cross-linked hydrogels, synthesized under various conditions, were used to grow lysozyme crystals by the counterdiffusion technique. Crystallization experiments were conducted using a three-layer arrangement. Results demonstrated that PEG fibers were incorporated within lysozyme crystals controlling the final crystal shape. PEG hydrogels also induced the nucleation of lysozyme crystals to a higher extent than agarose. PEG hydrogels can also be used at higher concentrations (20–50% w/w) as a separation chamber (plug) in counterdiffusion experiments. In this case, PEG hydrogels control the diffusion of the crystallization agent and therefore may be used to tailor the supersaturation to fine-tune crystal size. As an example, insulin crystals were grown in 10% (w/w) PEG hydrogel. The resulting crystals were of an approximate size of 500 ?m. PMID:25383049

  3. Analysis of partitioning of organic compounds and proteins in aqueous polyethylene glycol-sodium sulfate aqueous two-phase systems in terms of solute-solvent interactions.

    PubMed

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-10-01

    Partition behavior of nine small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.5M osmolyte (sorbitol, sucrose, trehalose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. It was found out that the partition coefficient of all compounds examined (including proteins) may be described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system differ from those in polyethylene glycol-dextran system. PMID:26342872

  4. Surface modification of ultrahigh molecular weight polyethylene by the poly(ethylene glycol)-grafted method and its effect on the adsorption of proteins and the adhesion of blood platelets.

    PubMed

    Xia, Bing; Xie, Meiju; Yang, Bangcheng

    2013-01-01

    With the help of a silane coupling agent, poly(ethylene glycol) (PEG), a well-biocompatable agent, was grafted onto the surface of ultrahigh molecular weight polyethylene (UHMWPE) by ultraviolet initiation. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis proved the success of PEG grafting. Water contact angle measurement showed that the modified UHMWPE was obviously improved in surface hydrophilicity and thermogravimetric analysis result showed that its thermostability did not decline even it was pretreated by strong acids. Then, the protein adsorption of the modified UHMWPE was investigated using three model proteins including bovine serum albumin, lysozyme, and fibrinogen. Rabbit blood was used to study the platelet adhesion on the surface of modified UHMWPE. The results indicated that the quantity of protein adsorption on the modified UHMWPE grafted PEG reduced apparently for all the model proteins while there was some specific differences or exceptions among them. It was ascribed to the changed surface chemical composition, surface hydrophilicity and surface topography after modification. The adhesive ability of blood platelets on the modified surface of UHMWPE decreased after PEG grafting. Owing to the improved resistance to fibrinogen adsorption and platelet adhesion, the surface modification might endow the UHWMPE surface better anticoagulation ability according to clotting mechanism. PMID:22807149

  5. The influence of poly(ethylene glycol) on the micelle formation of alkyl maltosides used in membrane protein crystallization.

    PubMed

    Müh, Frank; DiFiore, Dörte; Zouni, Athina

    2015-05-01

    With the aim of better understanding the phase behavior of alkyl maltosides (n-alkyl-?-d-maltosides, CnG2) under the conditions of membrane protein crystallization, we studied the influence of poly(ethylene glycol) (PEG) 2000, a commonly used precipitating agent, on the critical micelle concentration (CMC) of the alkyl maltosides by systematic variation of the number n of carbon atoms in the alkyl chain (n = 10, 11, and 12) and the concentration of PEG2000 (?) in a buffer suitable for the crystallization of cyanobacterial photosystem II. CMC measurements were based on established fluorescence techniques using pyrene and 8-anilinonaphthalene-1-sulfonate (ANS). We found an increase of the CMC with increasing PEG concentration according to ln(CMC/CMC0) = kP?, where CMC0 is the CMC in the absence of PEG and kP is a constant that we termed the "polymer constant". In parallel, we measured the influence of PEG2000 on the surface tension of detergent-free buffer solutions. At PEG concentrations ? > 1% w/v, the surface pressure ?s(?) = ?(0) - ?(?) was found to depend linearly on the PEG concentration according to ?s(?) = ?? + ?s(0), where ?(0) is the surface tension in the absence of PEG. Based on a molecular thermodynamic modeling, CMC shifts and surface pressure due to PEG are related, and it is shown that kP = ?c(n) + ?, where c(n) is a detergent-specific constant depending inter alia on the alkyl chain length n and ? is a correction for molarity. Thus, knowledge of the surface pressure in the absence of a detergent allows for the prediction of the CMC shift. The PEG effect on the CMC is discussed concerning its molecular origin and its implications for membrane protein solubilization and crystallization. PMID:25865704

  6. Studies of protein adsorption on implant materials in relation to biofilm formation I. Activity of Pseudomonas aeruginosa on Polypropylene and High density Polyethylene in presence of serum albumin

    E-print Network

    Sinha, S Dutta; Maity, P K; Tarafdar, S; Moulik, S P

    2014-01-01

    The surface of biomaterials used as implants are highly susceptible to bacterial colonization and subsequent infection. The amount of protein adsorption on biomaterials, among other factors, can affect the nature and quality of biofilms formed on them. The variation in the adsorption time of the protein on the biomaterial surface produces a phenotypic change in the bacteria by alteration of the production of EPS (exoplysaccharide) matrix. Knowledge of the effects of protein adsorption on implant infection will be very useful in understanding the chemistry of the biomaterial surfaces, which can deter the formation of biofilms. It is observed that the adsorption of BSA on the biomaterial surfaces increases with time and concentration, irrespective of their type and the nature of the EPS matrix of the bacterial biofilm is dependent on the amount of protein adsorbed on the biomaterial surface. The adsorption of protein (BSA) on the biomaterials, polypropylene (PP) and high density polyethylene (HDPE) has been stu...

  7. Polyethylene Glycol Propionaldehydes

    NASA Technical Reports Server (NTRS)

    Harris, Joe M.; Sedaghat-Herati, Mohammad R.; Karr, Laurel J.

    1992-01-01

    New class of compounds derived from polyethylene glycol (PEG's) namely, PEG-propionaldehydes, offers two important advantages over other classes of PEG aldehyde derivatives: compounds exhibit selective chemical reactivity toward amino groups and are stable in aqueous environment. PEG's and derivatives used to couple variety of other molecules, such as, to tether protein molecules to surfaces. Biotechnical and biomedical applications include partitioning of two phases in aqueous media; immobilization of such proteins as enzymes, antibodies, and antigens; modification of drugs; and preparation of protein-rejecting surfaces. In addition, surfaces coated with PEG's and derivatives used to control wetting and electroosmosis. Another potential application, coupling to aminated surfaces.

  8. Studies of protein adsorption on implant materials in relation to biofilm formation I. Activity of Pseudomonas aeruginosa on Polypropylene and High density Polyethylene in presence of serum albumin

    E-print Network

    S Dutta Sinha; Susmita Chatterjee; P. K. Maity; S. Tarafdar; S. P. Moulik

    2014-11-19

    The surface of biomaterials used as implants are highly susceptible to bacterial colonization and subsequent infection. The amount of protein adsorption on biomaterials, among other factors, can affect the nature and quality of biofilms formed on them. The variation in the adsorption time of the protein on the biomaterial surface produces a phenotypic change in the bacteria by alteration of the production of EPS (exoplysaccharide) matrix. Knowledge of the effects of protein adsorption on implant infection will be very useful in understanding the chemistry of the biomaterial surfaces, which can deter the formation of biofilms. It is observed that the adsorption of BSA on the biomaterial surfaces increases with time and concentration, irrespective of their type and the nature of the EPS matrix of the bacterial biofilm is dependent on the amount of protein adsorbed on the biomaterial surface. The adsorption of protein (BSA) on the biomaterials, polypropylene (PP) and high density polyethylene (HDPE) has been studied and the formation of the biofilms of Pseudomonas aeruginosa on them has been examined.

  9. Polymers for the stabilization and delivery of proteins topically and per os to the insect hemocoel through conjugation with aliphatic polyethylene glycol.

    PubMed

    Jeffers, Laura A; Shen, Hongyan; Bissinger, Brooke W; Khalil, Sayed; Gunnoe, T Brent; Roe, R Michael

    2014-10-01

    Co-feeding of aliphatic polyethylene glycol (PEG), phospholipase A2, anionic and ionic detergents, and amphipathic glycoside with bovine serum albumin (BSA) as a model protein to fourth stadium tobacco budworms, Heliothis virescens, did not affect the levels of BSA in the hemolymph. Covalent conjugation of small proteins like the decapeptide trypsin modulating oostatic factor (TMOF) to polyethylene glycol was previously shown to protect the peptide from protease attack and enhance its accumulation in the insect hemocoel. Whether this polymer chemistry could do the same for larger proteins was examined. The chemistry for the synthesis of polydispersed aliphatic PEG350-insulin and monodispersed aliphatic PEG333-insulin are described herein. Insulin was used for this synthesis and not BSA to better control conjugation among the available free amine groups. When PEGylated insulin or free insulin were fed in artificial diet to fifth stadium budworms, greater concentrations of insulin using the PEGylated variants were found in the hemolymph than when free insulin was used (a 6.7 and 7.3-fold increase for the PEG350 and PEG333 conjugates, respectively). When insulin is topically applied to the dorsum of H. virescens, no insulin is found in the hemolymph. However, after topical application of the PEGylated insulins, PEG350-insulin and PEG333-insulin were detected in the hemolymph. After injections of insulin into the hemocoel of fourth stadium H. virescens, insulin is completely cleared from the hemolymph in 120min. In comparison, PEG350-insulin and PEG333-insulin were present in the hemolymph for 300 and 240min after injection, respectively, translating to a 3.3 and 2.7-fold increase in the length of time insulin remains in the hemolymph after injection. PMID:25307467

  10. Polyethylene Glycol 3350

    MedlinePLUS

    Polyethylene glycol 3350 is used to treat occasional constipation. Polyethylene glycol 3350 is in a class of medications called ... Polyethylene glycol 3350 comes as a powder to be mixed with a liquid and taken by mouth. It ...

  11. Quantitative analysis of polyethylene glycol (PEG) and PEGylated proteins in animal tissues by LC-MS/MS coupled with in-source CID.

    PubMed

    Gong, Jiachang; Gu, Xiaomei; Achanzar, William E; Chadwick, Kristina D; Gan, Jinping; Brock, Barry J; Kishnani, Narendra S; Humphreys, W Griff; Iyer, Ramaswamy A

    2014-08-01

    The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins. PMID:25003239

  12. Protein resistance of surfaces prepared by sorption of end-thiolated poly(ethylene glycol) to gold: effect of surface chain density.

    PubMed

    Unsworth, Larry D; Sheardown, Heather; Brash, John L

    2005-02-01

    Nonspecific protein adsorption generally occurs at the biomaterial-tissue interface and usually has adverse consequences. Thus, surfaces that are protein-resistant are eagerly sought with the expectation that these materials will exhibit improved biocompatibility. Surfaces modified with end-tethered poly(ethylene oxide) (PEO) have been shown to be protein-resistant to some degree. Although the mechanisms are unclear, it has been suggested that chain length, chain density, and chain conformation are important factors. To investigate the effects of PEO chain density, we selected a model system based on the chemisorption of chain-end thiolated PEO to a gold substrate. Chain density was varied by varying PEO solubility (proximity to cloud point) and incubation time in the chemisorption solution. The adsorption of fibrinogen and lysozyme to these surfaces was investigated. It was found that for 750 and 2000 MW PEO layers, resistance to fibrinogen increased with chain density and was maximal at a density of approximately 0.5 chains/nm(2) (80% decrease in adsorption compared to unmodified gold). As PEO chain density increased beyond 0.5/nm(2) adsorption increased. For PEO of 5000 MW the optimal chain density was 0.27/nm(2) and gave only a 60% reduction in fibrinogen adsorption. It is suggested that, at high chain density, the chemisorbed PEO is dehydrated giving a surface that is no longer protein resistant. The PEO-modified surfaces were found also to be resistant to lysozyme adsorption with reductions similar to, if somewhat less than, those for fibrinogen. The fibrinogen to lysozyme molar ratios were within the expected range for close-packed layers of these proteins in their native conformation and were relatively insensitive to PEO chain density and MW. This may suggest that such adsorption as did occur, even at chain densities giving minimum adsorption, may have been on patches of unmodified gold. PMID:15667186

  13. Influence of poly(ethylene oxide)-based copolymer on protein adsorption and bacterial adhesion on stainless steel: modulation by surface hydrophobicity.

    PubMed

    Yang, Yi; Rouxhet, Paul G; Chudziak, Dorota; Telegdi, Judit; Dupont-Gillain, Christine C

    2014-06-01

    The aim of the present work is to study the adhesion of Pseudomonas NCIMB 2021, a typical aerobic marine microorganism, on stainless steel (SS) substrate. More particularly, the potential effect on adhesion of adsorbed poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer is investigated. Bacterial attachment experiments were carried out using a modified parallel plate flow chamber, allowing different surface treatments to be compared in a single experiment. The amount of adhering bacteria was determined via DAPI staining and fluorescence microscopy. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface chemical composition of SS and hydrophobized SS before and after PEO-PPO-PEO adsorption. The adsorption of bovine serum albumin (BSA), a model protein, was investigated to test the resistance of PEO-PPO-PEO layers to protein adsorption. The results show that BSA adsorption and Pseudomonas 2021 adhesion are significantly reduced on hydrophobized SS conditioned with PEO-PPO-PEO. Although PEO-PPO-PEO is also found to adsorb on SS, it does not prevent BSA adsorption nor bacterial adhesion, which is attributed to different PEO-PPO-PEO adlayer structures on hydrophobic and hydrophilic surfaces. The obtained results open the way to a new strategy to reduce biofouling on metal oxide surfaces using PEO-PPO-PEO triblock copolymer. PMID:24650936

  14. Polyethylene oxide surfaces of variable chain density by chemisorption of PEO-thiol on gold: adsorption of proteins from plasma studied by radiolabelling and immunoblotting.

    PubMed

    Unsworth, Larry D; Sheardown, Heather; Brash, John L

    2005-10-01

    The mechanisms involved in the inhibition of protein adsorption by polyethylene oxide (PEO) are not completely understood, but it is believed that PEO chain length, chain density and chain conformation all play a role. In this work, surfaces formed by chemisorption of PEO-thiol to gold were investigated: the effects of PEO chain density, chain length (600, 750, 2000 and 5000 MW) and end-group (-OH, -OCH3) on protein adsorption from plasma are reported. Similar to previous single protein adsorption studies (L.D. Unsworth et al., Langmuir 2005;21:1036-41) it was found that, of the different surfaces investigated, PEO layers formed from solutions near the cloud point adsorbed the lowest amount of fibrinogen from plasma. Layers of hydroxyl-terminated PEO of MW 600 formed under these low solubility conditions showed almost complete suppression (versus controls) of the Vroman effect, with 20+/-1 ng/cm2 adsorbed fibrinogen at the Vroman peak and 6.7+/-0.6 ng/cm2 at higher plasma concentration. By comparison, Vroman peak adsorption was 70+/-20 and 50+/-3 ng/cm2, respectively, for 750-OCH3 and 2000-OCH3 layers formed under low solubility conditions; adsorption on these surfaces at higher plasma concentration was 16+/-9 and 12+/-3 ng/cm2. Thus in addition to the effect of solution conditions noted previously, the results of this study also suggest a chain end group effect which inhibits fibrinogen adsorption to, and/or facilitates displacement from, hydroxyl terminated PEO layers. Fibrinogen adsorption from plasma was not significantly different for surfaces prepared with PEO of molecular weight 750 and 2000 when the chain density was the same ( approximately 0.5 chains/nm2) supporting the conclusion that chain density may be the key property for suppression of protein adsorption. The proteins eluted from the surfaces after contact with plasma were investigated by SDS-PAGE and immunoblotting. A number of proteins were detected on the various surfaces including fibrinogen, albumin, C3 and apolipoprotein A-I. The blot responses were zero or weak for all four proteins of the contact system; some complement activation was observed on all of the surfaces studied. PMID:15958239

  15. In situ immobilization of proteins and RGD peptide on polyurethane surfaces via poly(ethylene oxide) coupling polymers for human endothelial cell growth.

    PubMed

    Wang, Dong-an; Ji, Jian; Sun, Yong-hong; Shen, Jia-cong; Feng, Lin-xian; Elisseeff, Jennifer H

    2002-01-01

    A "CBABC"-type pentablock coupling polymer, mesylMPEO, was designed and synthesized to promote human endothelial cell growth on the surfaces of polyurethane biomaterials. The polymer was composed of a central 4,4'-methylenediphenyl diisocyanate (MDI) coupling unit and poly(ethylene oxide) (PEO) spacer arms with methanesulfonyl (mesyl) end groups pendent on both ends. As the presurface modifying additive (pre-SMA), the mesylMPEO was noncovalently introduced onto the poly(ether urethane) (PEU) surfaces by dip coating, upon which the protein/peptide factors (gelatin, albumin, and arginine-glycine-aspartic acid tripeptide [RGD]) were covalently immobilized in situ by cleavage of the original mesyl end groups. The pre-SMA synthesis and PEU surface modification were characterized using nuclear magnetic resonance spectroscopy ((1)H NMR), attenuated total reflection infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). Human umbilical vein endothelial cells (HUVEC) were harvested manually by collagenase digestion and seeded on the modified PEU surfaces. Cell adhesion ratios (CAR) and cell proliferation ratios (CPR) were measured using flow cytometry, and the individual cell viability (ICV) was determined by MTT assay. The cell morphologies were investigated by optical inverted microscopy (OIM) and scanning electrical microscopy (SEM). The gelatin- and RGD-modified surfaces were HUVEC-compatible and promoted HUVEC growth. The albumin-modified surfaces were compatible but inhibited cell adhesion. The results also indicated that, for HUVEC in vitro cultivation, the cell adhesion stage was of particular importance and had a significant impact on the cell responses to the modified surfaces. PMID:12425667

  16. Resistance to moist conditions of whey protein isolate and pea starch biodegradable films and low density polyethylene nondegradable films: a comparative study

    NASA Astrophysics Data System (ADS)

    Mehyar, G. F.; Bawab, A. Al

    2015-10-01

    Biodegradable packaging materials are degraded under the natural environmental conditions. Therefore using them could alleviate the problem of plastics accumulation in nature. For effective replacement of plastics, with biodegradable materials, biodegradable packages should keep their properties under the high relative humidity (RH) conditions. Therefore the objectives of the study were to develop biodegradable packaging material based on whey protein isolate (WPI) and pea starch (PS). To study their mechanical, oxygen barrier and solubility properties under different RHs compared with those of low density polyethylene (LDPE), the most used plastic in packaging. Films of WPI and PS were prepared separately and conditioned at different RH (30-90%) then their properties were studied. At low RHs (<50%), WPI films had 2-3 times lower elongation at break (E or stretchability) than PS and LDPE. Increasing RH to 90% significantly (P<0.01) increased the elongation of PS but not WPI and LDPE films. LDPE and WPI films kept significantly (P<0.01) higher tensile strength (TS) than PS films at high RH (90%). Oxygen permeability (OP) of all films was very low (<0.5 cm3 ?m m-2 d-1 kPa-1) below 40% RH but increased for PS films and became significantly (P<0.01) different than that of LDPE and WPI at > 40% RH. Oxygen permeability of WPI and LDPE did not adversely affected by increasing RH to 65%. Furthermore, WPI and LDPE films had lower degree of hydration at 50% and 90% RH and total soluble matter than PS films. These results suggest that WPI could be successfully replacing LDPE in packaging of moist products.

  17. Method for casting polyethylene pipe

    NASA Technical Reports Server (NTRS)

    Elam, R. M., Jr.

    1973-01-01

    Short lengths of 7-cm ID polyethylene pipe are cast in a mold which has a core made of room-temperature-vulcanizable (RTV) silicone. Core expands during casting and shrinks on cooling to allow for contraction of the polyethylene.

  18. Method for shaping polyethylene tubing

    NASA Technical Reports Server (NTRS)

    Kramer, R. C.

    1981-01-01

    Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.

  19. Polyethylene glycol modification decreases the cardiac toxicity of carbonaceous dots in mouse and zebrafish models

    PubMed Central

    Chen, Jian-tao; Sun, Hua-qin; Wang, Wei-liang; Xu, Wen-ming; He, Qin; Shen, Shun; Qian, Jun; Gao, Hui-le

    2015-01-01

    Aim: Carbonaceous dots (CDs), which have been used for diagnosis, drug delivery and gene delivery, are accumulated in heart at high concentrations. To improve their biocompatibility, polyethylene glycol-modified CDs (PEG-CDs) were prepared. In this study we compared the cardiac toxicity of CDs and PEG-CDs in mouse and zebrafish models. Methods: Mice were intravenously treated with CDs (size: 4.9 nm, 5 mg·kg?1·d?1) or PEG-CDs (size: 8.3 nm, 5 mg·kg?1·d?1) for 21 d. Their blood biochemistry indices, ECG, and histological examination were examined for evaluation of cardiac toxicity. CDs or PEG-CDs was added in incubator of cmlc2 transgenic Zebrafish embryos at 6 hpf, and the shape and size of embryos' hearts were observed at 48 hpf using a fluorescent microscope. Furthermore, whole-mount in situ hybridization was used to examine the expression of early cardiac marker gene (clml2) at 48 hpf. Results: Administration of CDs or PEG-CDs in mice caused mild, but statistically insignificant reduction in serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels detected at 7 d, which were returned to the respective control levels at 21 d. Neither CDs nor PEG-CDs caused significant changes in the morphology of heart cells. Administration of CDs, but not PEG-CDs, in mice caused marked increase of heart rate. Both CDs and PEG-CDs did not affect other ECG parameters. In the zebrafish embryos, addition of CDs (20 ?g/mL) caused heart development delay, whereas addition of CDs (80 ?g/mL) led to heart malformation. In contrast, PEG-CDs caused considerably small changes in heart development, which was consistent with the results from the in situ hybridization experiments. Conclusion: CDs causes greater cardiac toxicity, especially regarding heart development. Polyethylene glycol modification can attenuate the cardiac toxicity of CDs. PMID:26456589

  20. Poly(ethylene glycol)- and carboxylate-functionalized gold nanoparticles using polymer linkages: single-step synthesis, high stability, and plasmonic detection of proteins.

    PubMed

    Park, Garam; Seo, Daeha; Chung, Im Sik; Song, Hyunjoon

    2013-11-01

    Gold nanoparticles with suitable surface functionalities have been widely used as a versatile nanobioplatform. However, functionalized gold nanoparticles using thiol-terminated ligands have a tendency to aggregate, particularly in many enzymatic reaction buffers containing biological thiols, because of ligand exchange reactions. In the present study, we developed a one-step synthesis of poly(ethylene glycol) (PEG)ylated gold nanoparticles using poly(dimethylaminoethyl methacrylate) (PDMAEMA) in PEG as a polyol solvent. Because of the chelate effect of polymeric functionalities on the gold surface, the resulting PEGylated gold nanoparticles (Au@P-PEG) are very stable under the extreme conditions at which the thiol-monolayer-protected gold nanoparticles are easily coagulated. Using the solvent mixture of PEG and ethylene glycol (EG) and subsequent hydrolysis, gold nanoparticles bearing mixed functionalities of PEG and carboxylate are generated. The resulting particles exhibit selective adsorption of positively charged chymotrypsin (ChT) without nonselective adsorption of bovine serum albumin (BSA). The present nanoparticle system has many advantages, including high stability, simple one-step synthesis, biocompatibility, and excellent binding specificity; thus, this system can be used as a versatile platform for potential bio-related applications, such as separation, sensing, imaging, and assays. PMID:24090031

  1. Methoxy-Poly(ethylene glycol) Modified Poly(L-lactide) Enhanced Cell Affinity of Human Bone Marrow Stromal Cells by the Upregulation of 1-Cadherin and Delta-2-catenin

    PubMed Central

    Mao, Xueli; Chen, Zetao; Ling, Junqi; Quan, Jingjing; Peng, Hui; Xiao, Yin

    2014-01-01

    Poly(l-lactide) (PLLA), a versatile biodegradable polymer, is one of the most commonly-used materials for tissue engineering applications. To improve cell affinity for PLLA, poly(ethylene glycol) (PEG) was used to develop diblock copolymers. Human bone marrow stromal cells (hBMSCs) were cultured on MPEG-b-PLLA copolymer films to determine the effects of modification on the attachment and proliferation of hBMSC. The mRNA expression of 84 human extracellular matrix (ECM) and adhesion molecules was analyzed using RT-qPCR to understand the underlying mechanisms. It was found that MPEG-b-PLLA copolymer films significantly improved cell adhesion, extension, and proliferation. This was found to be related to the significant upregulation of two adhesion genes, CDH1 and CTNND2, which encode 1-cadherin and delta-2-catenin, respectively, two key components for the cadherin-catenin complex. In summary, MPEG-b-PLLA copolymer surfaces improved initial cell adhesion by stimulation of adhesion molecule gene expression. PMID:24834434

  2. Methoxy-poly(ethylene glycol) modified poly(L-lactide) enhanced cell affinity of human bone marrow stromal cells by the upregulation of 1-cadherin and delta-2-catenin.

    PubMed

    Mao, Xueli; Chen, Zetao; Ling, Junqi; Quan, Jingjing; Peng, Hui; Xiao, Yin

    2014-01-01

    Poly(L-lactide) (PLLA), a versatile biodegradable polymer, is one of the most commonly-used materials for tissue engineering applications. To improve cell affinity for PLLA, poly(ethylene glycol) (PEG) was used to develop diblock copolymers. Human bone marrow stromal cells (hBMSCs) were cultured on MPEG-b-PLLA copolymer films to determine the effects of modification on the attachment and proliferation of hBMSC. The mRNA expression of 84 human extracellular matrix (ECM) and adhesion molecules was analyzed using RT-qPCR to understand the underlying mechanisms. It was found that MPEG-b-PLLA copolymer films significantly improved cell adhesion, extension, and proliferation. This was found to be related to the significant upregulation of two adhesion genes, CDH1 and CTNND2, which encode 1-cadherin and delta-2-catenin, respectively, two key components for the cadherin-catenin complex. In summary, MPEG-b-PLLA copolymer surfaces improved initial cell adhesion by stimulation of adhesion molecule gene expression. PMID:24834434

  3. Effects of adding protein, condensed tannins, and polyethylene glycol to diets of sheep and goats fed one-seed juniper and low quality roughage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biochemical mechanisms that limit voluntary intake of one-seed juniper by browsing ruminants are not well understood. Twelve Rambouillet ewes (78 ± 2.3 kg BW) and 12 Boer-Spanish does (54 ± 1.4 kg BW) were used in a split-plot sequence design to investigate the effects of adding protein, quebrac...

  4. Effects of Biomass in Polyethylene or Polylactic Acid Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that compounding Polyethylene (PE) or Polylactic acid (PLA) with a dairy-based bioplastic resulted in composites with good mechanical properties. In this study, mass ratios of a dairy-protein-based material (DBP) ranging from 0, 5, 10 and 20 wt% replaced equivalent masse...

  5. Electromagnetic Characteristics of Thin Polyethylene-Carbon-Polyethylene Films

    NASA Astrophysics Data System (ADS)

    Volynets, N. I.; Lyubimov, A. G.; Plyushch, A. O.; Poddubskaya, O. G.; Kuzhir, P. P.; Korovin, E. Yu.; Suslyaev, V. I.; Macutkevic, J.; Pikutskaya, E. S.; Baturkin, S. A.; Klochkov, A. Ya.

    2015-09-01

    A method of manufacturing a polyethylene - expanded carbon - polyethylene layered structures which allows thin (down to 90 ?m) and flexible sandwiches to be easily made, is suggested. The electromagnetic properties of the manufactured composite materials at frequencies from 1 MHz to 3 GHz, 26-37.5 GHz, and 0.1-1.4 THz are analyzed. It is established that the material so obtained is opaque for the Ka microwave band due to high reflectivity (96-97%), does not transmit electromagnetic radiation of the terahertz range, has a high conductivity (up to 1 S/m) in the frequency range from 1 MHz to 1 GHz, and retains the main physical polyethylene properties (light weight, elasticity, and flexibility).

  6. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Fluorinated polyethylene food-contact articles are produced by modifying the surface of polyethylene articles through action of fluorine gas in combination with gaseous nitrogen as an inert diluent. Such modification affects only the surface of the...

  7. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Fluorinated polyethylene food-contact articles are produced by modifying the surface of polyethylene articles through action of fluorine gas in combination with gaseous nitrogen as an inert diluent. Such modification affects only the surface of the...

  8. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Fluorinated polyethylene food-contact articles are produced by modifying the surface of polyethylene articles through action of fluorine gas in combination with gaseous nitrogen as an inert diluent. Such modification affects only the surface of the...

  9. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Fluorinated polyethylene food-contact articles are produced by modifying the surface of polyethylene articles through action of fluorine gas in combination with gaseous nitrogen as an inert diluent. Such modification affects only the surface of the...

  10. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Fluorinated polyethylene food-contact articles are produced by modifying the surface of polyethylene articles through action of fluorine gas in combination with gaseous nitrogen as an inert diluent. Such modification affects only the surface of the...

  11. Profiles in garbage: Polyethylene terephthalate

    SciTech Connect

    Miller, C.

    1997-11-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks -- along with salad dressing, fruit juices, peanut butter, and other household and consumer products -- use PET bottles. PET also is used for film, sheeting for cups and food trays, oven-safe trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early 1970s. Because it is an ``engineered`` resin, PET is more expensive than commodity resins such as high-density polyethylene (HDPE) and, for the same reason, it is usually the highest valued plastic recyclable.

  12. Phosphorus contamination in polyethylene glycol.

    PubMed

    Reid, C P

    1978-04-01

    Concentrations of Fe, Mn, Cu, Zn, Ca, Mg, K, and P were examined in untreated and ion exchange resin-treated solutions of polyethylene glycol, molecular weight 3000 to 3700, polyethylene glycol (PEG 4000). Relatively high levels of P were found in untreated PEF-4000 solutions. The concentration of contaminating P in solutions prepared from untreated PEG 4000, even at high water potentials (-1 to -3 bars), was greater than what is usually found in soil solution. Occurrence of significant amounts of P in untreated PEG could introduce problems in experiments where (32)P and PEG are used together and where phosphate interactions may occur. PMID:16660369

  13. Waste product profile: Polyethylene terephthalate

    SciTech Connect

    Miller, C.

    1996-02-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks are the primary product packaged in PET. Salad dressing, peanut butter, and other household and consumer products also use PET bottles. PET is also used for film, sheeting for cups and food trays, ovenable trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early `70s. Because it is an ``engineered`` resin, it is more expensive than commodity resins such as high-density polyethylene (HDPE). The primary market for recycled PET is the fiber industry, which uses PET for carpet fiber, sweaters and other clothing, and for other uses. Recycled PET can also be used for food and beverage containers. Export markets, particularly Asian countries, are becoming increasingly important.

  14. Phase Structure and Properties of Poly(ethylene terephthalate)/High-Density Polyethylene Based on

    E-print Network

    -density polyethylene (LDPE), polypropylene (PP), Poly (ethylene terephthalate) (PET), etc. The plastic waste words: polyethylene; recycling; blends; poly(ethylene terephthalate) INTRODUCTION Plastics account for an increasing fraction of munici- pal solid waste around the world, and solid house- hold waste is made up

  15. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Amidoamine modified polyethylene glycol (generic). 721.6493... § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical...generically as an amidoamine modified polyethylene glycol (PMN P-99-0645) is...

  16. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Polyethylene resins, carboxyl modified. 177...Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as...

  17. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Polyethylene phthalate polymers. 177.1630 Section 177.1630...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  18. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Polyethylene phthalate polymers. 177.1630 Section 177.1630...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  19. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Polyethylene phthalate polymers. 177.1630 Section 177.1630...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  20. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Polyethylene phthalate polymers. 177.1630 Section 177.1630...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  1. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Polyethylene phthalate polymers. 177.1630 Section 177.1630...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  2. Poly(ethylene oxide) functionalization

    DOEpatents

    Pratt, Russell Clayton

    2014-04-08

    A simple procedure is provided by which the hydroxyl termini of poly(ethylene oxide) can be appended with functional groups to a useful extent by reaction and precipitation. The polymer is dissolved in warmed toluene, treated with an excess of organic base and somewhat less of an excess of a reactive acylating reagent, reacted for several hours, then precipitated in isopropanol so that the product can be isolated as a solid, and salt byproducts are washed away. This procedure enables functionalization of the polymer while not requiring laborious purification steps such as solvent-solvent extraction or dialysis to remove undesirable side products.

  3. Single electron states in polyethylene

    SciTech Connect

    Wang, Y.; School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 ; MacKernan, D.; Cubero, D. E-mail: n.quirke@imperial.ac.uk; Coker, D. F.; Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 ; Quirke, N. E-mail: n.quirke@imperial.ac.uk

    2014-04-21

    We report computer simulations of an excess electron in various structural motifs of polyethylene at room temperature, including lamellar and interfacial regions between amorphous and lamellae, as well as nanometre-sized voids. Electronic properties such as density of states, mobility edges, and mobilities are computed on the different phases using a block Lanczos algorithm. Our results suggest that the electronic density of states for a heterogeneous material can be approximated by summing the single phase density of states weighted by their corresponding volume fractions. Additionally, a quantitative connection between the localized states of the excess electron and the local atomic structure is presented.

  4. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Oxidized polyethylene. 172.260 Section 172.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene....

  5. 76 FR 70896 - Polyethylene Glycol; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... AGENCY 40 CFR Part 180 Polyethylene Glycol; Tolerance Exemption AGENCY: Environmental Protection Agency... amu), 17,000; also known as polyethylene glycol, when used as an inert ingredient in a pesticide... Findings In the Federal Register of August 26, 2011 (76 FR 53372) (FRL-8884- 9), EPA issued a...

  6. Nanoscale Calorimetry of Isolated Polyethylene Single Crystals

    E-print Network

    Allen, Leslie H.

    Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals with lamellar thicknesses of 12 1 nm. We observed the melting of as few as 25 crystals. Over a wide number

  7. Photon tunnelling microscopy of polyethylene single crystals

    E-print Network

    Srinivasarao, Mohan

    Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S polyethylenesinglecrystals, providing a topographical map ofthe single-crystal surface.Tunnelling increases exponentially:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

  8. Polyethylene crystallization in compatibilized polyethylene/polyamide 6 blends

    NASA Astrophysics Data System (ADS)

    Ceccia, Simona; Hynstova, Katerina; Fabre, Alexandra; Trouillet-Fonti, Lise; Long, Didier; Sotta, Paul

    2011-03-01

    Blends of semicrystalline polymers can exhibit much better properties than each of the pure polymers regarding e.g. impact/modulus compromise. Controlling the crystallization mechanisms (nucleation, kinetics) is a key factor to obtain the desired morphologies which lead to these unique properties. We have studied the crystallization of polyethylene (PE) in blends of PE and polyamide 6 (PA) compatibilized by PE functionalized with maleic anhydride (PE-g-MA, 1 wt% MA) obtained by reactive blending. Samples with different amounts of PA6 (0-60 %vol) have been investigated by polarized optical microscopy and Differential Scanning Calorimetry. The samples were heated at a temperature above the melting temperature of PE and below the melting temperature of PA, and then cooled at the selected crystallization temperature. We describe how the crystallization kinetics is modified by the presence of PA and MA.

  9. Chemical modification of lipase with polyethylene glycol

    SciTech Connect

    Baillargeon, M.W.; Sonnet, P.E.

    1986-05-01

    Proteins become soluble in selected organic solvents after covalent attachment of polyethylene glycol (PEG) to the free amino groups. A crude Candida rugosa lipase preparation was coupled with activated PEG to yield a PEG-lipase with both hydrolytic and synthetic activity in aqueous and organic media. The coupling step involved a modification of the procedure of Inada et al. To maintain lipase activity, mild reaction conditions were used: pH 7.5 or 8.0 buffer, 20 minutes reaction at room temperature. Up to 87% of the initial activity is retained in PEG-lipase. The PEG-lipase is soluble in aqueous solution, benzene and trichloroethane. The hydrolytic and synthetic activity of PEG-lipase in various organic solvents is compared to that of the native lipase; the PEG-lipase consistently shows higher specific activity, PEG-lipase also shows activity in iso-octane and cyclohexane, in which it is insoluble. The stability of PEG- and native lipase is solvent dependent.

  10. Photolithographic patterning of polyethylene glycol hydrogels.

    PubMed

    Hahn, Mariah S; Taite, Lakeshia J; Moon, James J; Rowland, Maude C; Ruffino, Katie A; West, Jennifer L

    2006-04-01

    A simple, inexpensive photolithographic method for surface patterning deformable, solvated substrates is demonstrated using photoactive poly(ethylene glycol) (PEG)-diacrylate hydrogels as model substrates. Photolithographic masks were prepared by printing the desired patterns onto transparencies using a laser jet printer. Precursor solutions containing monoacryloyl-PEG-peptide and photoinitiator were layered onto hydrogel surfaces. The acrylated moieties in the precursor solution were then conjugated in monolayers to specific hydrogel regions by exposure to UV light through the transparency mask. The effects of UV irradiation time and precursor solution concentration on the levels of immobilized peptide were characterized, demonstrating that bound peptide concentration can be controlled by tuning these parameters. Multiple peptides can be immobilized to a single hydrogel surface in distinct patterns by sequential application of this technique, opening up its potential use in co-cultures. In addition, 3D structures can be generated by incorporating PEG-diacrylate into the precursor solution. To evaluate the feasibility of using these patterned surfaces for guiding cell behavior, human dermal fibroblast adhesion on hydrogel surfaces patterned with acryloyl-PEG-RGDS was investigated. This patterning method may find use in tissue engineering, the elucidation of fundamental structure-function relationships, and the formation of immobilized cell and protein arrays for biotechnology. PMID:16375965

  11. Soluble hyperbranched grafts on polyethylene surfaces 

    E-print Network

    Britton, Danielle M

    2002-01-01

    Here we report two methods to synthesize hyperbranched poly(acrylic acid) grafts on polyethylene films and powders. The previously reported route using ?,[]-diaminopoly(tert-butyl acrylate) was repeated and all previous results were confirmed...

  12. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... polyethylene has a minimum number average molecular weight of 1,200, as determined by high temperature vapor pressure osmometry; contains a maximum of 5 percent by weight of total oxygen; and has an acid value of...

  13. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... chlorinated polyethylene contains a maximum of 60 percent by weight of total chlorine, as determined by ASTM 1method D1303-55 (Reapproved 1979), “Standard Test Method for Total Chlorine in Vinyl Chloride...

  14. Proteins.

    ERIC Educational Resources Information Center

    Doolittle, Russell F.

    1985-01-01

    Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

  15. Maxillofacial prostheses of chlorinated polyethylene.

    PubMed

    May, P D

    1978-05-01

    There is clearly a need for maxillofacial prosthetic materials with improved properties. The chlorinated polyethylenes are thermoplastic elastomers which have particularly promising properties, and were used by us to prepare improved maxillofacial prostheses. Suitable CPE resins were compounded with other polymers and with pigments on a heated rubber mill to form thin sheets in a variety of shades. These were heated at 190 degrees C for 10 min and placed between heated linotype mold halves. The prosthesis was formed in a hand press. Sometimes heating and pressing were repeated. After cooling in water, the prosthesis was removed and hand-shaded with oil-soluble dyes. Physical properties were evaluated using standard techniques; skin irritation studies were conducted by 14-day insult patch tests on rabbits. Clinical evaluations were conducted on human volunteers. Parallel evaluations were conducted on commerically available materials for comparison. The CPE was superior to all of the three commerical materials in most properties, and comparable to the better of the three in the remaining properties. On balance, CPE was significantly superior. Early results indicate that the materials and techniques required are easily handled in the dental lab and that the final prosthesis has excellent aesthetic and patient acceptability. PMID:670262

  16. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). 721.7255...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). (a) Chemical...polyethyleneamine crosslinked with substituted polyethylene glycol with substituted...

  17. Protein

    MedlinePLUS

    ... Go lean with protein. • Choose lean meats and poultry. Lean beef cuts include round steaks (top loin, ... main dishes. • Use nuts to replace meat or poultry, not in addition to meat or poultry (i. ...

  18. Protein

    MedlinePLUS

    ... Fruits Fats and Cholesterol Types of Fat Cholesterol Dietary fat and disease Calcium and Milk Vitamins Healthy Drinks ... the high protein diet saw improvements in blood lipids and blood pressure. ( 11 ) A more recent study ...

  19. Polymeric compositions incorporating polyethylene glycol as a phase change material

    DOEpatents

    Salyer, Ival O. (Dayton, OH); Griffen, Charles W. (Mason, OH)

    1989-01-01

    A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

  20. 76 FR 70965 - Polyethylene Retail Carrier Bags From Thailand: Correction to the Amended Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ...Polyethylene Retail Carrier Bags From Thailand: Correction to the Amended Final Results...polyethylene retail carrier bags from Thailand for the period August 1, 2009, through...polyethylene retail carrier bags from Thailand. See Polyethylene Retail Carrier...

  1. Recent advances in polyethylene separator technology

    NASA Astrophysics Data System (ADS)

    Weighall, M. J.

    The well known technical and production benefits of polyethylene separator materials over other separator materials have prompted a dramatic increase in polyethylene separator usage in recent years. Separator trends in the United States from 1980 to 1996, and in Europe from 1987 to 1992, are shown. The manufacturing process for polyethylene separators is outlined, with particular emphasis on the latest advances in manufacturing technology. These improvements have resulted in a higher quality product, and also benefit the environment because of the sophisticated oil extraction and solvent recovery system. The product quality improvements resulting from the latest manufacturing technology include consistent conformance to dimensional specifications, low electrical resistance, close control of residual oil content, virtual elimination of pinholes, and good running properties on the battery manufacturers' plate enveloping machines. The material can also be manufactured with a very thin backweb to reduce electrical resistance still further.

  2. Relationship between arterial thrombosis and neutralization of a polyethylene ionomer

    SciTech Connect

    Goggins, J.A.; Hiltner, A.; Jones, P.K. ); Jones, R.D. )

    1993-05-01

    The influence of three levels of sodium neutralization of an ethylene/methacrylic acid copolymer on in vivo blood compatibility was studied in a canine arterial model. Effects due to sample fabrication methods were also monitored. Sodium content, sodium release, hydrogen dissociation, and localization of anionic groups were noted. Polymer surface energy, surface morphology, water uptake, and thermal properties were characterized. Material characterization and in vivo implantation disclose the following: (1) thermal pressing generated oxidation degradation products that decreased in vivo blood compatibility. Solution-cast samples adhered and activated fewer blood elements; (2) platelets and leukocytes were sensitive to differences in shear rate in the carotid and femoral arteries, with the femoral site tending toward higher shear, more platelet deposition and fewer leukocytes; (3) the surface properties of the polyethylene control, 0% Na, and 50% Na samples tended to be similar. These properties were different from the 100% Na sample; (4) these differences were manifested in vivo by platelet activation and thrombus development on the polyethylene, 0% Na, and 50% Na implants, while the 100% Na implant surfaces were predominantly covered by singly adherent, unactivated platelets; (5) it is proposed that the improvement in biocompatibility for the 100% Na ionomer is due to the cluster development in the neutralized methacrylic component and that either directly, or through appropriate protein adsorption and/or conformational adjustment to the cluster regions, platelets are not activated and do not initiate the coagulation mechanism.

  3. 76 FR 8770 - Polyethylene Terephthalate (Pet) Film From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ...COMMISSION [Investigation No. 731-TA-459 (Third Review)] Polyethylene Terephthalate (Pet) Film From Korea AGENCY: United States...five-year review concerning the antidumping duty order on polyethylene terephthalate (PET) film from...

  4. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene and/or diethylene glycol may be used at a level not to exceed...

  5. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene and/or diethylene glycol may be used at a level not to exceed...

  6. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene and/or diethylene glycol may be used at a level not to exceed...

  7. Polyethylene glycol-electrolyte solution (PEG-ES)

    MedlinePLUS

    Polyethylene glycol-electrolyte solution (PEG-ES) is used to empty the colon (large intestine, bowel) before a colonoscopy ( ... Polyethylene glycol-electrolyte solution (PEG-ES) comes as a powder to mix with water and take by mouth. ...

  8. Adsorption of Polypropylene and Polyethylene on Liquid Chromatographic

    E-print Network

    Li, Jing

    Adsorption of Polypropylene and Polyethylene on Liquid Chromatographic Column Packings T. Macko1 tested as column packings for adsorption of isotactic polypropylene and linear polyethylene from dilute sorbent - mobile phase, where adsorption of polypropylene was observed. Keywords Column liquid

  9. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene and/or diethylene glycol may be used at a level not to...

  10. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene and/or diethylene glycol may be used at a level not to...

  11. Phosphorus Contamination in Polyethylene Glycol 1

    PubMed Central

    Reid, C. P. Patrick; Bowen, Glynn D.; McCleod, Stanley

    1978-01-01

    Concentrations of Fe, Mn, Cu, Zn, Ca, Mg, K, and P were examined in untreated and ion exchange resin-treated solutions of polyethylene glycol, molecular weight 3000 to 3700, polyethylene glycol (PEG 4000). Relatively high levels of P were found in untreated PEF-4000 solutions. The concentration of contaminating P in solutions prepared from untreated PEG 4000, even at high water potentials (?1 to ?3 bars), was greater than what is usually found in soil solution. Occurrence of significant amounts of P in untreated PEG could introduce problems in experiments where 32P and PEG are used together and where phosphate interactions may occur. PMID:16660369

  12. Non-isothermal Crystallization Kinetics of Linear Metallocene Polyethylenes

    E-print Network

    Hussein, Ibnelwaleed A.

    Non-isothermal Crystallization Kinetics of Linear Metallocene Polyethylenes Ibnelwaleed A. Hussein ABSTRACT The effect of Mw on the non-isothermal crystallization kinetics of metallocene linear polyethylene, metallocene polyethylene, non- isothermal crystallization, modulated DSC Email: ihussein@kfupm.edu.sa; Tel

  13. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  14. Morphological characteristics of selenium-polyethylene glycol nanocomposites

    NASA Astrophysics Data System (ADS)

    Kipper, A. I.; Titova, A. V.; Borovikova, L. N.; Pisarev, O. A.

    2015-09-01

    Hybrid organo-inorganic nanocomposites containing selenium nanoparticles stabilized with polyethylene glycols with different molecular masses were synthesized and studied by the static and dynamic scattering methods. It was shown that the morphological characteristics of nanocomposites can be regulated by varying the molecular mass of polyethylene glycols and the ratio of the selenium-polyethylene glycol components during the synthesis.

  15. Mechanisms for covalent immobilization of horseradish peroxi-dase on ion beam treated polyethylene

    E-print Network

    Kondyurin, Alexey V; Tilley, Jennifer M R; Nosworthy, Neil J; Bilek, Marcela M M; McKenzie, David R

    2011-01-01

    The mechanism that provides the observed strong binding of biomolecules to polymer sur-faces modified by ion beams is investigated. The surface of polyethylene (PE) was modified by plasma immersion ion implantation with nitrogen ions. Structure changes including car-bonization and oxidation were observed in the modified surface layer of PE by Raman spec-troscopy, FTIR ATR spectroscopy, atomic force microscopy, surface energy measurement and XPS spectroscopy. An observed high surface energy of the modified polyethylene was attributed to the presence of free radicals on the surface. The surface energy decay with stor-age time after PIII treatment was explained by a decay of the free radical concentration while the concentration of oxygen-containing groups increased with storage time. Horseradish per-oxidase was covalently attached onto the modified PE surface. The enzymatic activity of co-valently attached protein remained high. A mechanism based on the covalent attachment by the reaction of protein with free r...

  16. Solubility of Lysozyme in Polyethylene Glycol-Electrolyte Mixtures: The Depletion Interaction and Ion-Specific Effects

    PubMed Central

    Bon?ina, Matjaž; Reš?i?, Jurij; Vlachy, Vojko

    2008-01-01

    The solubility of aqueous solutions of lysozyme in the presence of polyethylene glycol and various alkaline salts was studied experimentally. The protein-electrolyte mixture was titrated with polyethylene glycol, and when precipitation of the protein occurred, a strong increase of the absorbance at 340 nm was observed. The solubility data were obtained as a function of experimental variables such as protein and electrolyte concentrations, electrolyte type, degree of polymerization of polyethylene glycol, and pH of the solution; the last defines the net charge of the lysozyme. The results indicate that the solubility of lysozyme decreases with the addition of polyethylene glycol; the solubility is lower for a polyethylene glycol with a higher degree of polymerization. Further, the logarithm of the protein solubility is a linear function of the polyethylene glycol concentration. The process is reversible and the protein remains in its native form. An increase of the electrolyte (NaCl) concentration decreases the solubility of lysozyme in the presence and absence of polyethylene glycol. The effect can be explained by the screening of the charged amino residues of the protein. The solubility experiments were performed at two different pH values (pH = 4.0 and 6.0), where the lysozyme net charge was +11 and +8, respectively. Ion-specific effects were systematically investigated. Anions such as Br?, Cl?, F?, and \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{H}}_{2}{\\mathrm{PO}}_{4}^{-}\\end{equation*}\\end{document} (all in combination with Na+), when acting as counterions to a protein with positive net charge, exhibit a strong effect on the lysozyme solubility. The differences in protein solubility for chloride solutions with different cations Cs+, K+, and Na+ (coions) were much smaller. The results at pH = 4.0 show that anions decrease the lysozyme solubility in the order \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{F}}^{-}\\hspace{.167em}<\\hspace{.167em}{\\mathrm{H}}_{2}{\\mathrm{PO}}_{4}^{-}\\hspace{.167em}<\\hspace{.167em}{\\mathrm{Cl}}^{-}\\hspace{.167em}<\\hspace{.167em}{\\mathrm{Br}}^{-}\\end{equation*}\\end{document} (the inverse Hofmeister series), whereas cations follow the direct Hofmeister series (Cs+ < K+ < Na+) in this situation. PMID:18441020

  17. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and......

  18. Dynamic compressive behavior of foamed polyethylene film

    NASA Astrophysics Data System (ADS)

    Tateyama, Kohei; Yamada, Hiroyuki; Ogasawara, Nagahisa; Okui, Ryo; Ogawa, Kinya

    2015-09-01

    The foamed film as the shock absorption material has attracted much attention because it is thin (100 ?m ˜ 400 ?m) and has a closed cell structure. However, the dynamic mechanical properties have not been reported in the foamed film. The purpose of this study is to elucidate the compressive behavior of the foamed polyethylene film at the wide strain rate range. First, the new compressive test apparatus for the dynamic strain rate, the drop-weight testing machine with opposed load cell, was developed, which can be also evaluated the dynamic stress equilibrium of the specimen. It is confirmed that the compressive flow stress increased with increasing the strain rate, regardless of the film thickness. The foamed polyethylene film has the high strain rate sensitivity in the quasi-static deformation. On the other hand, there is almost no change of the strain rate sensitivity in the dynamic and the impact deformation. In order to investigate the mechanism of strain rate dependence, the foamed polyethylene film was observed by X-ray computed tomography scanner before and after compressive test. The fracture of the closed cell only occurred in the quasi-static deformation. It was clarified that the strain rate sensitivity of the foamed film depends strongly on that of the construction material, polyethylene.

  19. Herbicide dissipation from low density polyethylene mulch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field and laboratory studies were conducted to examine herbicide dissipation when applied to low density polyethylene (LDPE) mulch for dry scenarios vs. washing off with water. In field studies, halosulfuron, paraquat, carfentrazone, glyphosate, and flumioxazin were applied to black 1.25-mil LDPE at...

  20. Preservation of Mercury in Polyethylene Containers.

    ERIC Educational Resources Information Center

    Piccolino, Samuel Paul

    1983-01-01

    Reports results of experiments favoring use of 0.5 percent nitric acid with an oxidant (potassium dichromate or potassium permanganate) to preserve samples in polyethylene containers for mercury analysis. Includes procedures used and statistical data obtained from the experiments. (JN)

  1. Evaluation of Paulownia elongata wood polyethylene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paulownia wood flour (PWF), a byproduct of milling lumber, was employed as a bio-filler and blended with high density polyethylene (HDPE) via extrusion. Paulownia wood (PW) shavings were milled through a 1-mm screen then separated via shaking into various particle fractions using sieves (#30 - < #2...

  2. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Polyethylene. 573.780 Section 573.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

  3. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Polyethylene. 573.780 Section 573.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

  4. POLYETHYLENE ENCAPSULATES FOR HAZARDOUS WASTE DRUMS

    EPA Science Inventory

    This capsule report summarizes studies of the use of polyethylene (P.E.) for encapsulating drums of hazardous wastes. Flat PE sheet is welded to roto moded PE containers which forms the encapsulates. Plastic pipe welding art was used, but the prototype welding apparatus required ...

  5. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Oxidized polyethylene. 172.260 Section 172.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances...

  6. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Oxidized polyethylene. 172.260 Section 172.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances...

  7. STRESS CRACK TESTING OF POLYETHYLENE GEOMEMBRANES

    EPA Science Inventory

    The sensitivity of high density polyethylene (HDPE) geomembranes to stress cracking is evaluated under accelerated conditions at a constant stress. he test specimens are according to ASTM D-1822, and are of the dumbbell shape with a constant length in the central section. he acce...

  8. Fabrication of poly(ethylene glycol) hydrogel microstructures using photolithography

    NASA Technical Reports Server (NTRS)

    Revzin, A.; Russell, R. J.; Yadavalli, V. K.; Koh, W. G.; Deister, C.; Hile, D. D.; Mellott, M. B.; Pishko, M. V.

    2001-01-01

    The fabrication of hydrogel microstructures based upon poly(ethylene glycol) diacrylates, dimethacrylates, and tetraacrylates patterned photolithographically on silicon or glass substrates is described. A silicon/silicon dioxide surface was treated with 3-(trichlorosilyl)propyl methacrylate to form a self-assembled monolayer (SAM) with pendant acrylate groups. The SAM presence on the surface was verified using ellipsometry and time-of-flight secondary ion mass spectrometry. A solution containing an acrylated or methacrylated poly(ethylene glycol) derivative and a photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was spin-coated onto the treated substrate, exposed to 365 nm ultraviolet light through a photomask, and developed with either toluene, water, or supercritical CO2. As a result of this process, three-dimensional, cross-linked PEG hydrogel microstructures were immobilized on the surface. Diameters of cylindrical array members were varied from 600 to 7 micrometers by the use of different photomasks, while height varied from 3 to 12 micrometers, depending on the molecular weight of the PEG macromer. In the case of 7 micrometers diameter elements, as many as 400 elements were reproducibly generated in a 1 mm2 square pattern. The resultant hydrogel patterns were hydrated for as long as 3 weeks without delamination from the substrate. In addition, micropatterning of different molecular weights of PEG was demonstrated. Arrays of hydrogel disks containing an immobilized protein conjugated to a pH sensitive fluorophore were also prepared. The pH sensitivity of the gel-immobilized dye was similar to that in an aqueous buffer, and no leaching of the dye-labeled protein from the hydrogel microstructure was observed over a 1 week period. Changes in fluorescence were also observed for immobilized fluorophore labeled acetylcholine esterase upon the addition of acetyl acholine.

  9. Biodegradation of low-density polyethylene by marine bacteria from pelagic waters, Arabian Sea, India.

    PubMed

    Harshvardhan, Kumar; Jha, Bhavanath

    2013-12-15

    Sixty marine bacteria isolated from pelagic waters were screened for their ability to degrade low-density polyethylene; among them, three were positive and able to grow in a medium containing polythene as the sole carbon source. The positive isolates were identified as Kocuria palustris M16, Bacillus pumilus M27 and Bacillus subtilis H1584 based on the 16S rRNA gene sequence homology. The weight loss of polyethylene was 1%, 1.5% and 1.75% after 30 days of incubation with the M16, M27 and H1584 isolates, respectively. The maximum (32%) cell surface hydrophobicity was observed in M16, followed by the H1584 and M27 isolates. The viability of the isolates growing on the polyethylene surface was confirmed using a triphenyltetrazolium chloride reduction test. The viability was also correlated with a concomitant increase in the protein density of the biomass. Polyethylene biodegradation was further confirmed by an increase in the Keto Carbonyl Bond Index, the Ester Carbonyl Bond Index and the Vinyl Bond Index, which were calculated from FT-IR spectra. PMID:24210946

  10. Mechanisms for Covalent Immobilization of Horseradish Peroxidase on Ion-Beam-Treated Polyethylene

    PubMed Central

    Kondyurin, Alexey V.; Naseri, Pourandokht; Tilley, Jennifer M. R.; Nosworthy, Neil J.; Bilek, Marcela M. M.; McKenzie, David R.

    2012-01-01

    The surface of polyethylene was modified by plasma immersion ion implantation. Structure changes including carbonization and oxidation were observed. High surface energy of the modified polyethylene was attributed to the presence of free radicals on the surface. The surface energy decay with storage time after treatment was explained by a decay of the free radical concentration while the concentration of oxygen-containing groups increased with storage time. Horseradish peroxidase was covalently attached onto the modified surface by the reaction with free radicals. Appropriate blocking agents can block this reaction. All aminoacid residues can take part in the covalent attachment process, providing a universal mechanism of attachment for all proteins. The native conformation of attached protein is retained due to hydrophilic interactions in the interface region. The enzymatic activity of covalently attached protein remained high. The long-term activity of the modified layer to attach protein is explained by stabilisation of unpaired electrons in sp2 carbon structures. A high concentration of free radicals can give multiple covalent bonds to the protein molecule and destroy the native conformation and with it the catalytic activity. The universal mechanism of protein attachment to free radicals could be extended to various methods of radiation damage of polymers. PMID:24278665

  11. Analytical rheology of metallocene-catalyzed polyethylenes

    NASA Astrophysics Data System (ADS)

    Shanbhag, Sachin; Takeh, Arsia

    2011-03-01

    A computational algorithm that seeks to invert the linear viscoelastic spectrum of single-site metallocene-catalyzed polyethylenes is presented. The algorithm uses a general linear rheological model of branched polymers as its underlying engine, and is based on a Bayesian formulation that transforms the inverse problem into a sampling problem. Given experimental rheological data on unknown single-site metallocene- catalyzed polyethylenes, it is able to quantitatively describe the range of values of weight-averaged molecular molecular weight, MW , and average branching density, bm , consistent with the data. The algorithm uses a Markov-chain Monte Carlo method to simulate the sampling problem. If, and when information about the molecular weight is available through supplementary experiments, such as chromatography or light scattering, it can easily be incorporated into the algorithm, as demonstrated. Financial support from NSF DMR 0953002.

  12. Polyethylene in knee arthroplasty: A review

    PubMed Central

    Chakrabarty, Gautam; Vashishtha, Mayank; Leeder, Daniel

    2015-01-01

    Polyethylene (PE) has been used extensively in knee arthroplasty since the mid 20th century. Progress in material manufacturing and processing has led to newer polyethylenes over last few decades with different material properties. It has been established that PE wear in knee arthroplasty causes particle induced osteolysis which is the main reason for late failure and requires revision surgery. Although there are various causes of wear, the properties of PE have long been a matter of investigation as a contributory factor. The advent of newer highly cross linked PE has been shown to improve wear rates in hip arthroplasty but the benefits have not been shown to be of the same degree in knee arthroplasty. The laboratory and clinical studies so far are limited and slightly conflicting in their conclusions. The risks of using highly cross linked PE in knee arthroplasty include tibial post fracture, disruption of locking mechanism, liner fracture which can lead to increased wear and osteolysis. The current evidence suggests that highly cross linked polyethylenes should be used with caution and only considered in younger active patients. The results of a recently completed randomized trial to compare the conventional with high molecular weight PE in knee arthroplasty are awaited. PMID:25983517

  13. Oral toxicity and bacterial mutagenicity studies with a spunbond polyethylene and polyethylene terephthalate polymer fabric.

    PubMed

    Merski, Jerome A; Johnson, William D; Muzzio, Miguel; Lyang, Nei-Long; Gaworski, Charles L

    2008-01-01

    Spunbond, nonwoven fabrics consisting of polyethylene and polyethylene terephthalate, which meet food contact requirements, may be used as pouch materials for products containing food and/or flavor ingredients that are held in the mouth. In these situations ingestion may occur, resulting in exposure to the fabric and potentially antimony, a catalyst used in polyethylene terephthalate. To assess potential adverse effects when such a material is ingested, a 13 week dietary study in Sprague-Dawley CD rats and a Salmonella reverse mutation assay were conducted. Ground fabric was dosed at target concentrations of 0.5%, 2.5%, and 5% in the dietary study. Antimony trioxide in the polyethylene terephthalate was used to determine the test material concentration in the diet and was also assessed for bioavailability. Detectable levels of antimony were found in 2/20 blood samples of control rats, and in 20/20 high-dose group rats. No toxicologically relevant treatment related effects were observed in any of end points evaluated in the feeding study. In the mutagenicity assay, ground fabric was extracted in phosphate buffered saline or dimethysulfoxide and tested in Salmonella strains TA98, TA100, TA102, TA1535, and TA1537 with and without S9 activation. No mutagenic response was observed at any dose level tested. These results demonstrate that repeated daily ingestion of a spunbond, nonwoven polymer fabric consisting of polyethylene and polyethylene terephthalate for up to 13 weeks is well tolerated in rats, with no apparent target-organ toxicity at dietary levels up to 5%, and that fabric extracts are not mutagenic in a bacterial reverse mutation assay. PMID:19037809

  14. The yield behavior of polyethylene tubes subjected to biaxial loadings

    NASA Technical Reports Server (NTRS)

    Semeliss, M.; Wong, R.; Tuttle, M.

    1990-01-01

    High-density polyethylene is subjected to biaxial states of stress to examine the yield behavior of the semicrystalline thermoplastic under constant octahedral shear-stress rates. Combinations of internal pressures and axial loads are applied to thin-walled tubes of polyethylene, and the strain response in the axial and hoop directions are measured. The polyethylene specimens are found to be anisotropic, and the experimental measurements are compared to yield criteria that are applicable to isotropic and anisotropic materials.

  15. Crystallization of polyethylene by modified weighted density approximation(MWDA)

    E-print Network

    Razeghizadeh, Alireza; Lavafpour, Farhad

    2015-01-01

    In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

  16. Crystallization of polyethylene by modified weighted density approximation(MWDA)

    E-print Network

    Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

    2015-02-07

    In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

  17. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Alkyl polyethylene glycol phosphate, potassium salt. 721.3900 Section 721.3900...Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical substances and...alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is...

  18. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Alkyl polyethylene glycol phosphate, potassium salt. 721.3900 Section 721.3900...Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical substances and...alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is...

  19. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Alkyl polyethylene glycol phosphate, potassium salt. 721.3900 Section 721.3900...Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical substances and...alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is...

  20. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Alkyl polyethylene glycol phosphate, potassium salt. 721.3900 Section 721.3900...Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical substances and...alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is...

  1. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Alkyl polyethylene glycol phosphate, potassium salt. 721.3900 Section 721.3900...Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical substances and...alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is...

  2. 77 FR 2959 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ...Trade Administration [A-570-886] Polyethylene Retail Carrier Bags From the People's...review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from...PRC. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From the...

  3. 77 FR 9892 - Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary Intent to Rescind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ...Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet and Strip...countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip...respect to Vacmet and Polypacks. See Polyethylene Terephthalate Film, Sheet and...

  4. 78 FR 48147 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ...Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip...countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip...gauges of raw, pretreated, or primed polyethylene terephthalate film, sheet and...

  5. 78 FR 78333 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...Antidumping Duty Administrative Review: Polyethylene Terephthalate Film, Sheet, and...

  6. 76 FR 76948 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ...Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip...results of the administrative review of polyethylene terephthalate film, sheet and strip...Background Since the issuance of Polyethylene Terephthalate Film, Sheet, and...

  7. 77 FR 73010 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates; Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...of raw, pre- treated, or primed polyethylene terephthalate film, whether...

  8. 77 FR 73428 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...Antidumping Duty Administrative Review: Polyethylene Terephthalate Film, Sheet, and...

  9. 78 FR 2365 - Polyethylene Terephthalate Film, Sheet and Strip From India: Partial Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ...Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet and Strip...the antidumping duty (AD) order on polyethylene terephthalate film, sheet and strip...Plastics (America), Inc. \\3\\ See Polyethylene Terephthalate (PET) Film,...

  10. 78 FR 88 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ...Trade Administration [A-570-886] Polyethylene Retail Carrier Bags From the People's...review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from...August 31, 2012, the petitioners, the Polyethylene Retail Carrier Bag Committee and...

  11. 78 FR 35245 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  12. 76 FR 75870 - Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Notice of Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ...Trade Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, [[Page...revocation of the antidumping duty order on polyethylene terephthalate film, sheet, and...

  13. 75 FR 23667 - Antidumping Duty Orders: Polyethylene Retail Carrier Bags from Indonesia, Taiwan, and the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ...A-552-806 Antidumping Duty Orders: Polyethylene Retail Carrier Bags from Indonesia...issuing antidumping duty orders on polyethylene retail carrier bags (PRCBs) from...investigation of PRCBs from Taiwan. See Polyethylene Retail Carrier Bags from Taiwan:...

  14. 78 FR 79400 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Initiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...Background The antidumping duty order on polyethylene terephthalate film, sheet, and...

  15. 76 FR 71512 - Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ...Trade Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  16. 78 FR 46319 - Polyethylene Retail Carrier Bags From Taiwan: Initiation of Anti-Circumvention Inquiry on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ...Trade Administration [A-583-843] Polyethylene Retail Carrier Bags From Taiwan: Initiation...In response to a request from The Polyethylene Retail Carrier Bag Committee and its...determine whether imports of unfinished polyethylene retail carrier bags (PRCBs) on...

  17. 78 FR 77649 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates; Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...of raw, pre- treated, or primed polyethylene terephthalate film, whether...

  18. 75 FR 78968 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...order on PET Film from the UAE. See Polyethylene Terephthalate Film, Sheet, and...

  19. 78 FR 48143 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ...Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...Antidumping Duty Administrative Review: Polyethylene Terephthalate Film, Sheet, and...

  20. 77 FR 19634 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission of Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ...Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet and Strip...countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip...respect to Vacmet and Polypacks. See Polyethylene Terephthalate Film, Sheet and...

  1. 76 FR 50456 - Notice of Final Results of Antidumping Duty Changed Circumstances Review: Polyethylene...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ...Duty Changed Circumstances Review: Polyethylene Terephthalate Film, Sheet, and Strip...regard to the antidumping duty order on polyethylene terephthalate film, sheet, and strip...of Sales at Less Than Fair Value: Polyethylene Terephthalate Film, Sheet, and...

  2. 75 FR 80457 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ...Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet and strip...through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and...

  3. 76 FR 30908 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ...Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip...results of the new shipper review of polyethylene terephthalate film, sheet and strip...Background Since the issuance of Polyethylene Terephthalate Film, Sheet, and...

  4. 76 FR 57715 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Revocation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ...Trade Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...existing antidumping duty order on polyethylene terephthalate film, sheet, and...

  5. 78 FR 9670 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ...Trade Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film (PET Film) from...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  6. 76 FR 76365 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...order on PET Film from the UAE. See Polyethylene Terephthalate Film, Sheet, and...

  7. 78 FR 67113 - Polyethylene Terephthalate Film, Sheet and Strip From India and Taiwan: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ...Administration [A-533-824, A-583-837] Polyethylene Terephthalate Film, Sheet and Strip...review of the antidumping duty orders on Polyethylene Terephthalate Film, Sheet and Strip...Value and Antidumping Duty Order: Polyethylene Terephthalate Film, Sheet, and...

  8. 76 FR 30910 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ...Trade Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip...results of the new shipper review of polyethylene terephthalate film, sheet and strip...Background Since the issuance of Polyethylene Terephthalate Film, Sheet, and...

  9. 75 FR 10758 - Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping Duty and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ...Administration [A-533-824, C-533-825] Polyethylene Terephthalate Film, Sheet and Strip...countervailing duty (CVD) orders on Polyethylene Terephthalate Film, Sheet and Strip...Value and Antidumping Duty Order: Polyethylene Terephthalate Film, Sheet, and...

  10. 78 FR 76280 - Polyethylene Retail Carrier Bags From the People's Republic of China: Affirmative Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ...Trade Administration [A-570-886] Polyethylene Retail Carrier Bags From the People's...determines that imports of unfinished polyethylene retail carrier bags (PRCBs) from...1\\ See Antidumping Duty Order: Polyethylene Retail Carrier Bags From the...

  11. 75 FR 23670 - Polyethylene Retail Carrier Bags from the Socialist Republic of Vietnam: Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ...Trade Administration (C-552-805) Polyethylene Retail Carrier Bags from the Socialist...issuing a countervailing duty order on polyethylene retail carrier bags (PRCBs) from...investigation of PRCBs from Vietnam. See Polyethylene Retail Carrier Bags from the...

  12. 75 FR 61128 - Polyethylene Retail Carrier Bags From Malaysia: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ...Trade Administration [A-557-813] Polyethylene Retail Carrier Bags From Malaysia...review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from...and invited parties to comment. See Polyethylene Retail Carrier Bags From...

  13. 78 FR 48651 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan; Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ...Trade Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...1\\ See Polyethylene Terephthalate Film, Sheet and...

  14. 76 FR 61085 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...results of the administrative review of polyethylene terephthalate film, sheet, and strip...results of the review by 60 days. See Polyethylene Terephthalate Film, Sheet, and...

  15. 76 FR 11203 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ...Trade Administration [A-570-886] Polyethylene Retail Carrier Bags From the People's...review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from...PRC. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From the...

  16. 78 FR 47276 - Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ...Trade Administration [C-533-825] Polyethylene Terephthalate (PET) Film, Sheet...of the countervailing duty order on polyethylene terephthalate (PET) film, sheet...Notice of Countervailing Duty Order: Polyethylene Terephthalate Film, Sheet, and...

  17. 77 FR 14493 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-12

    ...Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip...antidumping duty administrative review of polyethylene terephthalate film, sheet, and strip...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  18. 75 FR 16434 - Polyethylene Retail Carrier Bags From the Socialist Republic of Vietnam: Final Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ...Trade Administration [A-552-806] Polyethylene Retail Carrier Bags From the Socialist...Department'') has determined that polyethylene retail carrier bags (``PRCBs...LTFV, as provided in the Act. See Polyethylene Retail Carrier Bags From the...

  19. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Pentenylated polyethylene glycol sulfate salt (generic). 721.10546 Section 721...Pentenylated polyethylene glycol sulfate salt (generic). (a) Chemical substance...pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject to...

  20. 78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-18

    ... AGENCY 40 CFR Part 180 Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride... oil, polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. (CAS Reg. No... residues of tall oil, polymer with polyethylene glycol and succinic anhydride monopolyisobutylene...

  1. 75 FR 23673 - Polyethylene Retail Carrier Bags from Thailand: Extension of Time Limit for Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ...A-549-821 Polyethylene Retail Carrier Bags from Thailand: Extension of Time Limit...order on polyethylene retail carrier bags from Thailand. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From Thailand, 69 FR 48204...

  2. 78 FR 78748 - 2,5-Furandione, polymer With ethenylbenzene, Reaction Products With polyethylene-polypropylene...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ...with ethenylbenzene, reaction products with polyethylene-polypropylene...ingredient in a pesticide chemical formulation. Huntsman...with ethenylbenzene, reaction products with polyethylene-polypropylene...with ethenylbenzene, reaction products with polyethylene-polypropylene...efforts to determine which chemicals have a common...

  3. 75 FR 36359 - Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ...Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for Preliminary...polyethylene retail carrier bags from Thailand. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From Thailand, 69 FR 48204 (August 9,...

  4. 78 FR 28192 - Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ...Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of Antidumping...polyethylene retail carrier bags (PRCBs) from Thailand. The review covers 11 respondents...Polyethylene Retail Carrier Bags from Thailand,'' dated concurrently with this...

  5. 75 FR 34699 - Polyethylene Retail Carrier Bags from Thailand: Rescission of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ...Polyethylene Retail Carrier Bags from Thailand: Rescission of Antidumping Duty Administrative...polyethylene retail carrier bags from Thailand. The period of review is August 1...polyethylene retail carrier bags from Thailand. See Initiation of Antidumping and...

  6. 77 FR 25684 - Polyethylene Retail Carrier Bags From Thailand: Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-01

    ...Polyethylene Retail Carrier Bags From Thailand: Rescission of Antidumping Duty Administrative...polyethylene retail carrier bags from Thailand. The period of review is August 1...polyethylene retail carrier bags from Thailand. See Initiation of Antidumping and...

  7. 76 FR 59999 - Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ...Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...polyethylene retail carrier bags from Thailand. We gave interested parties an opportunity...Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of...

  8. Why do polyethylene crystals have sectors?

    PubMed Central

    Dorset, D L; Hanlon, J; McConnell, C H; Fryer, J R; Lotz, B; Wittmann, J C; Beckmann, E; Zemlin, F

    1990-01-01

    High-resolution (3.7 A in optical diffraction) electron microscope images have been obtained from a series of n-paraffin monolamellar crystals with chain lengths from n-C36H74 to n-C82H166. The higher molecular weight specimens, which do not undergo chain folding, form sectorized crystals and the molecular packing is found to include alternate bands of untilted and tilted chains along <130>. Their widths are consistent with those of Bragg fringe widths in bright-field images obtained at lower magnification. The chain tilt axis is near d*110. Lower molecular weight paraffins form nonsectorized crystals where the chains are generally untilted with occasional small inclinations around nonspecific axes. Surface decoration of the longer alkanes with polyethylene crystallites, first of all, reveals three preferred polyethylene crystal rod orientations ([100] plus two perpendicular to [110]) instead of the two commonly found for the lower alkane. Control studies on solid-solution crystals reveal that the third [100] orientation is a result of slight surface roughness due to unequal chain lengths or surface protrusions of chains; the new decoration is also randomly distributed. For pure n-C60H122 lamellae, however, suggestions of regular bands containing rods along [100], due to surface discontinuities along <130>, can also be seen. In contrast with polyethylene, these data suggest that crystal sectorization may be a function of chain-stem packing alone and that chain folds may play merely a secondary role in the polymer--e.g., by directing the collapse of pyramidal crystals on a flat surface. Images PMID:11607068

  9. Patterned functional carbon fibers from polyethylene

    SciTech Connect

    Hunt, Marcus A; Saito, Tomonori; Brown, Rebecca H; Kumbhar, Amar S; Naskar, Amit K

    2012-01-01

    Patterned, continuous carbon fibers with controlled surface geometry were produced from a novel melt-processible carbon precursor. This portends the use of a unique technique to produce such technologically innovative fibers in large volume for important applications. The novelties of this technique include ease of designing and fabricating fibers with customized surface contour, the ability to manipulate filament diameter from submicron scale to a couple of orders of magnitude larger scale, and the amenable porosity gradient across the carbon wall by diffusion controlled functionalization of precursor. The geometry of fiber cross-section was tailored by using bicomponent melt-spinning with shaped dies and controlling the melt-processing of the precursor polymer. Circular, trilobal, gear-shaped hollow fibers, and solid star-shaped carbon fibers of 0.5 - 20 um diameters, either in self-assembled bundle form, or non-bonded loose filament form, were produced by carbonizing functionalized-polyethylene fibers. Prior to carbonization, melt-spun fibers were converted to a char-forming mass by optimizing the sulfonation on polyethylene macromolecules. The fibers exhibited distinctly ordered carbon morphologies at the outside skin compared to the inner surface or fiber core. Such order in carbon microstructure can be further tuned by altering processing parameters. Partially sulfonated polyethylene-derived hollow carbon fibers exhibit 2-10 fold surface area (50-500 m2/g) compared to the solid fibers (10-25 m2/g) with pore sizes closer to the inside diameter of the filaments larger than the sizes on the outer layer. These specially functionalized carbon fibers hold promise for extraordinary performance improvements when used, for example, as composite reinforcements, catalyst support media, membranes for gas separation, CO2 sorbents, and active electrodes and current collectors for energy storage applications.

  10. Biocompatible composites of ultrahigh molecular weight polyethylene

    NASA Astrophysics Data System (ADS)

    Panin, S. V.; Kornienko, L. A.; Suan, T. Nguen; Ivanova, L. P.; Korchagin, M. A.; Chaikina, M. V.; Shilko, S. V.; Pleskachevskiy, Yu. M.

    2015-10-01

    Mechanical and tribotechnical characteristics of biocompatible, antifriction and extrudable composites based on ultrahigh molecular weight polyethylene (UHMWPE) as well as hybrid matrix "UHMWPE + PTFE" with biocompatible hydroxyapatite filler under the dry friction and boundary lubrication were investigated. A comparative analysis of effectiveness of adding the hydroxyapatite to improve the wear resistance of composites based on these two matrices was performed. It is shown that the wear intensity of nanocomposites based on the hybrid matrix is lower than that for the composites based on pure UHMWPE. Possibilities of using the composites of the polymer "UHMWPE-PTFE" mixture as a material for artificial joints implants are discussed.

  11. Nonlinear viscoelastic characterization of thin polyethylene film

    NASA Technical Reports Server (NTRS)

    Wilbeck, J. S.

    1981-01-01

    In order to understand the state of stress and strain in a typical balloon fabricated from thin polyethylene film, experiment data in the literature reviewed. It was determined that the film behaves as a nonlinear viscoelasticity material and should be characterized accordingly. A simple uniaxial, nonlinear viscoelastic model was developed for predicting stress given a certain strain history. The simple model showed good qualitative agreement with results of constant rate, uniaxial accurately predicting stresses for cyclic strain histories typical of balloon flights. A program was outlined which will result in the development of a more complex nonlinear viscoelastic model.

  12. Initial Stages of the Pyrolysis of Polyethylene.

    PubMed

    Popov, Konstantin V; Knyazev, Vadim D

    2015-12-10

    An experimental study of the kinetics of the initial stages of the pyrolysis of high-density polyethylene (PE) was performed. Quantitative yields of gas-phase products (C1-C8 alkanes and alkenes) and functional groups within the remaining polyethylene melt (methyl, vinyl, vinylene, vinylidene, and branching sites) were obtained as a function of time (0-20 min) at five temperatures in the 400-440 °C range. Gas chromatography and NMR ((1)H and (13)C) were used to detect the gas- and condensed-phase products, respectively. Modeling of polyethylene pyrolysis was performed, with the primary purpose of determining the rate constants of several critical reaction types important at the initial pyrolysis stages. Detailed chemical mechanisms were created (short and extended mechanisms) and used with both the steady-state approximation and numerical integration of the differential kinetic equations. Rate constants of critical elementary reactions (C-C backbone scission, two kinds of H-atom transfer, radical addition to the double bond, and beta-scission of tertiary alkyl radicals) were adjusted, resulting in an agreement between the model and the experiment. The values of adjusted rate constants are in general agreement with those of cognate reactions of small molecules in the gas phase, with the exception of the rate constants of the backbone C-C scission, which is found to be approximately 1-2 orders of magnitude lower. This observation provides tentative support to the hypothesis that congested PE melt molecular environment impedes the tumbling motions of separating fragments in C-C bond scission, thus resulting in less "loose" transition state and lower rate constant values. Sensitivity of the calculations to selected uncertainties in model properties was studied. Values and estimated uncertainties of four combinations of rate constants are reported as derived from the experimental results via modeling. The dependence of the diffusion-limited rate constant for radical recombination on the changing molecular mass of polyethylene was explicitly quantified and included in the extended kinetic mechanism, which appears critical for the agreement between modeling and experiment, particularly the agreement between the experimental and the calculated activation energies for product formation rates. Calculations were performed to estimate the contribution to the overall rate of radical recombination of the "reaction diffusion" phenomenon, where recombination is driven not by the actual motion of the recombining radical sites but rather by the migration of the radical site through PE melt due to rapid hydrogen transfer; this contribution was shown to be negligible for the conditions of the current work. PMID:26503638

  13. Polyethylene terephthalate thin films; a luminescence study

    NASA Astrophysics Data System (ADS)

    Carmona-Téllez, S.; Alarcón-Flores, G.; Meza-Rocha, A.; Zaleta-Alejandre, E.; Aguilar-Futis, M.; Murrieta S, H.; Falcony, C.

    2015-04-01

    Polyethylene Terephthalate (PET) films doped with Rare Earths (RE3+) have been deposited on glass by spray pyrolysis technique at 240 °C, using recycled PET and (RE3+) chlorides as precursors. Cerium, terbium, dysprosium and europium were used as dopants materials, these dopants normally produce luminescent emissions at 450, 545, 573 and 612 nm respectively; the doped films also have light emissions at blue, green, yellow and red respectively. All RE3+ characteristic emissions were observed at naked eyes. Every deposited films show a high transmission in the visible range (close 80% T), films surfaces are pretty soft and homogeneous. Films thickness is around 3 ?m.

  14. 76 FR 12700 - Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ...Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...polyethylene retail carrier bags from Thailand. We gave interested parties an opportunity...Page 12701

  15. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Polyethylene phthalate films consist of a base sheet of ethylene terephthalate polymer, ethylene terephthalate....1315(b)(3), to which have been added optional substances, either as constituents of the base sheet or as constituents of coatings applied to the base sheet. (b) Polyethylene phthalate articles consist...

  16. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... following prescribed conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene... as constituents of the base sheet or as constituents of coatings applied to the base sheet. (b) Polyethylene phthalate articles consist of a base polymer of ethylene terephthalate polymer, or...

  17. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... following prescribed conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene... as constituents of the base sheet or as constituents of coatings applied to the base sheet. (b) Polyethylene phthalate articles consist of a base polymer of ethylene terephthalate polymer, or...

  18. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... following prescribed conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene... as constituents of the base sheet or as constituents of coatings applied to the base sheet. (b) Polyethylene phthalate articles consist of a base polymer of ethylene terephthalate polymer, or...

  19. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... following prescribed conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene... as constituents of the base sheet or as constituents of coatings applied to the base sheet. (b) Polyethylene phthalate articles consist of a base polymer of ethylene terephthalate polymer, or...

  20. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  1. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  2. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  3. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  4. SECURING CONTAINERIZED HAZARDOUS WASTES WITH POLYETHYLENE RESIN AND FIBERGLASS ENCAPSULATES

    EPA Science Inventory

    This study investigates the fabrication and use of polyethylene resin and fiberglass to encapsulate and secure containerized hazardous wastes. Laboratory-scale encapsulates of composite structure were made from powdered, high-density polyethylene (HDPE) and epoxy-resin-wetted fib...

  5. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under this... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amidoamine modified...

  6. Automated Assessment of Polyethylene Wear in Cemented Acetabular Components using

    E-print Network

    Ulidowski, Irek

    Automated Assessment of Polyethylene Wear in Cemented Acetabular Components using Anteroposterior, Ninewells Hospital, Dundee, DD1 9SY, UK Abstract Polyethylene wear in the acetabular components of hip prostheses is implicated in loosening and failure. Radiographic measurement of wear is used to identify

  7. Impact perforation of monolithic polyethylene plates: projectile nose shape dependence

    E-print Network

    Mohagheghian, I.; McShane, G. J.; Stronge, W. J.

    2015-02-12

    -crystalline thermoplastics. The focus of the study is light-weight monolithic plates of extruded polymer impacted normally by rigid projectiles at velocities up to 100 ms?1. Three polymers will be considered: Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE...

  8. DC Current in Nanosilica-based Polyethylene Nanocomposites

    E-print Network

    DC Current in Nanosilica-based Polyethylene Nanocomposites Yan Wang, Zhiqiang Xu, George Chen Kingdom yw14g13@soton.ac.uk Abstract ­ In the present paper, DC current of polyethylene nanocomposites the nanometer-sized particles, which is currently termed as nanodielectrics or nanocomposites. During past 20

  9. Revision of the polyethylene component for wear in TKA.

    PubMed

    Whiteside, Leo A; Katerberg, Brian

    2006-11-01

    Given reports of failure in isolated polyethylene exchange in well-fixed TKA components, we asked whether isolated exchange could be successful either by replacing the polyethylene in implants whose locking mechanism accepts currently available polyethylene designs or by creating a new locking mechanism fabricated with a carbide bit and augmented with polymethylmethacrylate cement. We performed isolated liner exchange for wear in 46 patients (49 knees). The polyethylene locking mechanism in two total knee designs (13 knees) allowed polyethylene exchange without polymethylmethacrylate fixation. A locking mechanism was fabricated for three implant designs (36 knees). Clinical function after polyethylene component exchange was good in all but three knees. No knees with a fabricated locking mechanism failed. The mechanical strength of the fabricated locking mechanism was tested in the laboratory. The cement- fabricated locking mechanism in the unmodified tray notably outperformed the standard polyethylene locking mechanism. Isolated polyethylene component exchange was successful in this small clinical study. Fabricating a locking mechanism with a carbide bit and acrylic cement was effective in laboratory testing and clinical application. PMID:16967039

  10. Degradation of Green Polyethylene by Pleurotus ostreatus

    PubMed Central

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Ribeiro, Karla Veloso Gonçalves; Mendes, Igor Rodrigues; Kasuya, Maria Catarina Megumi

    2015-01-01

    We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers. PMID:26076188

  11. Nanostructurization and thermal properties of polyethylenes' welds

    NASA Astrophysics Data System (ADS)

    Galchun, Anatoliy; Korab, Nikolay; Kondratenko, Volodymyr; Demchenko, Valeriy; Shadrin, Andriy; Anistratenko, Vitaliy; Iurzhenko, Maksym

    2015-03-01

    As it is known, polyethylene (PE) is one of the common materials in the modern world, and PE products take the major share on industrial and trade markets. For example, various types of technical PE like PE-63, PE-80, and PE-100 have wide industrial applications, i.e., in construction, for pipeline systems etc. A rapid development of plastics industry outstrips detailed investigation of welding processes and welds' formation mechanism, so they remain unexplored. There is still no final answer to the question how weld's microstructure forms. Such conditions limit our way to the understanding of the problem and, respectively, prevent scientific approaches to the welding of more complicated (from chemical point of view) types of polymers than PE. Taking into account state-of-the-art, the article presents results of complex studies of PE weld, its structure, thermophysical and operational characteristics, analysis of these results, and basing on that some hypotheses of welded joint and weld structure formation. It is shown that welding of dissimilar types of polyethylene, like PE-80 and PE-100, leads to the formation of better-ordered crystallites, restructuring the crystalline phase, and amorphous areas with internal stresses in the welding zone.

  12. Nanostructurization and thermal properties of polyethylenes' welds.

    PubMed

    Galchun, Anatoliy; Korab, Nikolay; Kondratenko, Volodymyr; Demchenko, Valeriy; Shadrin, Andriy; Anistratenko, Vitaliy; Iurzhenko, Maksym

    2015-01-01

    As it is known, polyethylene (PE) is one of the common materials in the modern world, and PE products take the major share on industrial and trade markets. For example, various types of technical PE like PE-63, PE-80, and PE-100 have wide industrial applications, i.e., in construction, for pipeline systems etc. A rapid development of plastics industry outstrips detailed investigation of welding processes and welds' formation mechanism, so they remain unexplored. There is still no final answer to the question how weld's microstructure forms. Such conditions limit our way to the understanding of the problem and, respectively, prevent scientific approaches to the welding of more complicated (from chemical point of view) types of polymers than PE. Taking into account state-of-the-art, the article presents results of complex studies of PE weld, its structure, thermophysical and operational characteristics, analysis of these results, and basing on that some hypotheses of welded joint and weld structure formation. It is shown that welding of dissimilar types of polyethylene, like PE-80 and PE-100, leads to the formation of better-ordered crystallites, restructuring the crystalline phase, and amorphous areas with internal stresses in the welding zone. PMID:25897302

  13. Degradation of Green Polyethylene by Pleurotus ostreatus.

    PubMed

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Ribeiro, Karla Veloso Gonçalves; Mendes, Igor Rodrigues; Kasuya, Maria Catarina Megumi

    2015-01-01

    We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers. PMID:26076188

  14. Recycling of irradiated high-density polyethylene

    NASA Astrophysics Data System (ADS)

    Navratil, J.; Manas, M.; Mizera, A.; Bednarik, M.; Stanek, M.; Danek, M.

    2015-01-01

    Radiation crosslinking of high-density polyethylene (HDPE) is a well-recognized modification of improving basic material characteristics. This research paper deals with the utilization of electron beam irradiated HDPE (HDPEx) after the end of its lifetime. Powder of recycled HDPEx (irradiation dose 165 kGy) was used as a filler into powder of virgin low-density polyethylene (LDPE) in concentrations ranging from 10% to 60%. The effect of the filler on processability and mechanical behavior of the resulting mixtures was investigated. The results indicate that the processability, as well as mechanical behavior, highly depends on the amount of the filler. Melt flow index dropped from 13.7 to 0.8 g/10 min comparing the lowest and the highest concentration; however, the higher shear rate the lower difference between each concentration. Toughness and hardness, on the other hand, grew with increasing addition of the recycled HDPEx. Elastic modulus increased from 254 to 450 MPa and material hardness increased from 53 to 59 ShD. These results indicate resolving the problem of further recycling of irradiated polymer materials while taking advantage of the improved mechanical properties.

  15. The adhesion of oxygen-plasma treated poly(ethylene) and poly(ethylene terephthlate) films

    SciTech Connect

    Holton, S.L.; Kinloch, A.J.; Watts, J.F.

    1996-12-31

    The effects of low-pressure oxygen-plasma treatment on the surfaces of poly(ethylene) (PE) and poly(ethylene terephthlate) (PET) films and its influence on the adhesion of PE/PET laminates were assessed. The 90{degree} peel test was used to estimate the adhesive fracture energy, G{sub c} for the laminates. XPS, SEM and AFM were used to analyse the treated films and fracture surfaces. Significant improvements in bond strength occurred within very short treatment times (5s at 50W) with the maximum adhesion occurring after 300s. For longer treatment times the bond strengths decrease slightly. G{sub c} values were found to be low when PET was the peel arm. When PE was the peel arm, the G{sub c} values were substantially larger using the current analysis.

  16. Polyethylene Oxide (PEO) and Polyethylene Glycol (PEG) Polymer Sieving Matrix for RNA Capillary Electrophoresis

    PubMed Central

    Yamaguchi, Yoshinori; Li, Zhenqing; Zhu, Xifang; Liu, Chenchen; Zhang, Dawei; Dou, Xiaoming

    2015-01-01

    The selection of sieving polymer for RNA fragments separation by capillary electrophoresis is imperative. We investigated the separation of RNA fragments ranged from 100 to 10,000 nt in polyethylene glycol (PEG) and polyethylene oxide (PEO) solutions with different molecular weight and different concentration. We found that the separation performance of the small RNA fragments (<1000 nt) was improved with the increase of polymer concentration, whereas the separation performance for the large ones (>4000 nt) deteriorated in PEG/PEO solutions when the concentration was above 1.0%/0.6%, respectively. By double logarithmic plot of mobility and RNA fragment size, we revealed three migration regimes for RNA in PEG (300-500k) and PEO (4,000k). Moreover, we calculated the smallest resolvable nucleotide length (Nmin) from the resolution length analysis. PMID:25933347

  17. Novel Nanoparticles Formed via Self-Assembly of Poly(ethylene glycol-b-sebacic anhydride) and Their Degradation in Water

    E-print Network

    Wu, Chi

    ; Revised Manuscript Received September 19, 2000 ABSTRACT: A novel diblock copolymer, poly(ethylene oxide attracted a particular attention since PEG is nontoxic and has a low protein adsorption and cell adhesion.28,29 The most important is that the internal use of PEG in the human body has been approved by the Food and Drug

  18. Myocardial matrix-polyethylene glycol hybrid hydrogels for tissue engineering

    NASA Astrophysics Data System (ADS)

    Grover, Gregory N.; Rao, Nikhil; Christman, Karen L.

    2014-01-01

    Similar to other protein-based hydrogels, extracellular matrix (ECM) based hydrogels, derived from decellularized tissues, have a narrow range of mechanical properties and are rapidly degraded. These hydrogels contain natural cellular adhesion sites, form nanofibrous networks similar to native ECM, and are biodegradable. In this study, we expand the properties of these types of materials by incorporating poly(ethylene glycol) (PEG) into the ECM network. We use decellularized myocardial matrix as an example of a tissue specific ECM derived hydrogel. Myocardial matrix-PEG hybrids were synthesized by two different methods, cross-linking the proteins with an amine-reactive PEG-star and photo-induced radical polymerization of two different multi-armed PEG-acrylates. We show that both methods allow for conjugation of PEG to the myocardial matrix by gel electrophoresis and infrared spectroscopy. Scanning electron microscopy demonstrated that the hybrid materials still contain a nanofibrous network similar to unmodified myocardial matrix and that the fiber diameter is changed by the method of PEG incorporation and PEG molecular weight. PEG conjugation also decreased the rate of enzymatic degradation in vitro, and increased material stiffness. Hybrids synthesized with amine-reactive PEG had gelation rates of 30 min, similar to the unmodified myocardial matrix, and incorporation of PEG did not prevent cell adhesion and migration through the hydrogels, thus offering the possibility to have an injectable ECM hydrogel that degrades more slowly in vivo. The photo-polymerized radical systems gelled in 4 min upon irradiation, allowing 3D encapsulation and culture of cells, unlike the soft unmodified myocardial matrix. This work demonstrates that PEG incorporation into ECM-based hydrogels can expand material properties, thereby opening up new possibilities for in vitro and in vivo applications.

  19. Thermoviscoelastic models for polyethylene thin films

    NASA Astrophysics Data System (ADS)

    Li, Jun; Kwok, Kawai; Pellegrino, Sergio

    2015-11-01

    This paper presents a constitutive thermoviscoelastic model for thin films of linear low-density polyethylene subject to strains up to yielding. The model is based on the free volume theory of nonlinear thermoviscoelasticity, extended to orthotropic membranes. An ingredient of the present approach is that the experimentally inaccessible out-of-plane material properties are determined by fitting the model predictions to the measured nonlinear behavior of the film. Creep tests, uniaxial tension tests, and biaxial bubble tests are used to determine the material parameters. The model has been validated experimentally, against data obtained from uniaxial tension tests and biaxial cylindrical tests at a wide range of temperatures and strain rates spanning two orders of magnitude.

  20. Investigation of Raman spectra of polyethylene terephthalate

    NASA Astrophysics Data System (ADS)

    Zhu, Changjun; Tong, Na; Song, Lixin; Zhang, Guoqing

    2015-08-01

    Raman spectrometry was employed to study the characteristics of Raman spectra of polyethylene terephthalate (PET), which were treated with sodium hydroxide, sulfuric acid and copper sulfate, respectively. Raman spectra under different conditions were obtained and the characteristics of the Raman spectra were analyzed. The morphology structures were observed under different conditions using Atomic Force Microscope. The results show that the spectral intensity of PET treated with sodium hydroxide is higher than that untreated between 200-1750 cm-1, while the intensity of PET treated with sodium hydroxide is lower than that untreated beyond 1750 cm-1 and the fluorescence background of Raman spectra is decreased. The spectral intensity of PET treated with sulfuric acid is remarkably reduced than that untreated, and the intensity of PET treated with copper sulphate is much higher than that untreated.

  1. Role of polyethylene glycol in childhood constipation.

    PubMed

    Phatak, Uma Padhye; Pashankar, Dinesh S

    2014-09-01

    Constipation is a common and chronic problem in children worldwide. Long-term use of laxatives is necessary for successful treatment of chronic constipation. Commonly used laxatives in children include milk of magnesia, lactulose, mineral oil, and polyethylene glycol (PEG). Recent studies report the efficacy and safety of PEG for the long-term treatment of constipation in children. Because of its excellent patient acceptance, PEG is being used widely in children for constipation. In this commentary, we review the recently published pediatric literature on the efficacy, safety, and patient acceptance of PEG. We also assess the role of PEG in childhood constipation by comparing it with other laxatives in terms of efficacy, safety, patient acceptance, and cost. PMID:24108331

  2. Crosslinked polyethylene foams, via EB radiation

    NASA Astrophysics Data System (ADS)

    Cardoso, E. C. L.; Lugão, A. B.; Andrade E. Silva, L. G.

    1998-06-01

    Polyethylene foams, produced by radio-induced crosslinking, show a smooth and homogeneous surface, when compared to chemical crosslinking method using peroxide as crosslinking agent. This process fosters excellent adhesive and printability properties. Besides that, closed cells, intrinsic to theses foams, imparts opitmum mechanical, shocks and insulation resistance, indicating these foams to some markets segments as: automotive and transport; buoyancy, flotation and marine: building and insulation: packaging: domestic sports and leisure goods. We were in search of an ideal foam, by adding 5 to 15% of blowing agent in LDPE. A series of preliminary trials defined 203° C as the right blowing agent decomposition temperature. At a 22.7 kGy/dose ratio, the lowest dose for providing an efficient foam was 30 kGy, for a formulation comprising 10% of azodicarbonamide in LDPE, within a 10 minutes foaming time.

  3. Thermal conductivity of electrospun polyethylene nanofibers

    NASA Astrophysics Data System (ADS)

    Ma, Jian; Zhang, Qian; Mayo, Anthony; Ni, Zhonghua; Yi, Hong; Chen, Yunfei; Mu, Richard; Bellan, Leon M.; Li, Deyu

    2015-10-01

    We report on the structure-thermal transport property relation of individual polyethylene nanofibers fabricated by electrospinning with different deposition parameters. Measurement results show that the nanofiber thermal conductivity depends on the electric field used in the electrospinning process, with a general trend of higher thermal conductivity for fibers prepared with stronger electric field. Nanofibers produced at a 45 kV electrospinning voltage and a 150 mm needle-collector distance could have a thermal conductivity of up to 9.3 W m-1 K-1, over 20 times higher than the typical bulk value. Micro-Raman characterization suggests that the enhanced thermal conductivity is due to the highly oriented polymer chains and enhanced crystallinity in the electrospun nanofibers.

  4. Viscoplastic tearing of polyethylene thin film

    NASA Astrophysics Data System (ADS)

    Hegyi, Dezso; Pellegrino, Sergio

    2015-05-01

    Recent advances in noncontact strain measurement techniques and large-strain constitutive modeling of the linear low-density polyethylene film used in NASA superpressure balloons StratoFilm 420 are combined to provide a novel measurement technique for the tear propagation critical value of the J-integral. Previously these measurements required complex test configurations and procedures. It is found that the critical value of the J-integral increases by approximately 50 % when the strain rate is decreased from 1.33×10-4 s-1 to 1.33×10-5 s-1. It is shown that there is good correlation between measurements made on uniaxially loaded dogbone samples and circular diaphragms loaded by pressure, both with a 2-mm-wide slit in the middle. This result indicates that more extensive studies of strain-rate dependence may be made with the simpler, uniaxial test configuration.

  5. The shock response of polyoxymethylene and polyethylene

    NASA Astrophysics Data System (ADS)

    Bourne, N. K.; Millett, J. C. F.; Goveas, S. G.

    2007-09-01

    In the past few years, a series of papers has examined the shock response of common engineering polymers as their microstructure changes. In this latest work, the behaviour of two polymers, polyoxymethylene and polyethylene, is investigated under conditions of shock loading in one-dimensional strain. The two are semi-crystalline thermoplastics differing only in the components of the chain. Equation of state data are investigated for the low pressure (up < 1 km s-1) regime. Further, measurements of the lateral component of stress and knowledge of the impact conditions allow calculation of the shear strength. Variations both with impact stress amplitude and pulse duration are discussed in terms of the polymer chain structure.

  6. Thermal conductivity of electrospun polyethylene nanofibers.

    PubMed

    Ma, Jian; Zhang, Qian; Mayo, Anthony; Ni, Zhonghua; Yi, Hong; Chen, Yunfei; Mu, Richard; Bellan, Leon M; Li, Deyu

    2015-10-01

    We report on the structure-thermal transport property relation of individual polyethylene nanofibers fabricated by electrospinning with different deposition parameters. Measurement results show that the nanofiber thermal conductivity depends on the electric field used in the electrospinning process, with a general trend of higher thermal conductivity for fibers prepared with stronger electric field. Nanofibers produced at a 45 kV electrospinning voltage and a 150 mm needle-collector distance could have a thermal conductivity of up to 9.3 W m(-1) K(-1), over 20 times higher than the typical bulk value. Micro-Raman characterization suggests that the enhanced thermal conductivity is due to the highly oriented polymer chains and enhanced crystallinity in the electrospun nanofibers. PMID:26412240

  7. Crystallization of polyethylenes at very high supercooling

    NASA Astrophysics Data System (ADS)

    Wagner, John Edward

    The crystallization behavior of a series of ethylene-octene copolymers synthesized using metallocene catalysts has been studied using the Ding-Spruiell method of rapid cooling. In conventional crystallization experiments it was found, as expected, that the spherulite growth rates varied with octene content and molecular weight. When studied at rapid cooling rates the polymers generate their own pseudo-isothermal crystallization temperatures, in agreement with Ding-Spruiell's studies on other systems, however, at the lowest temperatures of crystallization, the spherulite growth rates of all the copolymers studied merge. The WAXD results indicate at the faster crystallization rates that the size of the unit cell unit decreases with decreasing crystallization temperature. A resulting increase in the surface free energy plays a role in the behavior of the copolymers such that spherulitic growth rates of copolymers begin to surpass that of the linear polyethylene at very high supercooling. This is a change in the behavior of the copolymers that should be of considerable relevance to polymer processing conditions. Spinodal transformation could play of role in the leveling off of growth rates at high supercooling. The crystallization and morphology of four LLDPE samples produced using metallocene catalysts through the copolymerization of ethylene and octene has been studied. The second part of the study is primarily concerned with the growth kinetics obtained through experimentally determined growth rates at different crystallization temperatures of low and high molecular weight samples. Using experimentally determined equilibrium melting points secondary nucleation behavior is studied in detail. Three Regimes are seen for a molecular weight 101,000 with no branching and at 60,000 with branching at 4 octenes per 1000 carbons. Two Regimes have been obtained for a sample of similar molecular weight but with branching at 17 octenes per 1000 carbons. Lamellar thickness data in the rapid cooling region correlate well with previous studies of the equilibrium melting temperature of the linear polyethylene. Andrews plot data shows a three-stem nucleus in Regime III.

  8. Effect of sodium chloride on solute-solvent interactions in aqueous polyethylene glycol-sodium sulfate two-phase systems.

    PubMed

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-12-18

    Partition behavior of eight small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.215M NaCl and 0.5M osmolyte (sorbitol, sucrose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate-0.215M NaCl system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. The partition coefficients of all compounds examined (including proteins) were described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system change in the presence of NaCl additive. PMID:26615710

  9. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  10. Temperature-responsive surface-functionalized polyethylene films 

    E-print Network

    Ponder, Bill C.

    1998-01-01

    PE-PEG-Pyrene cooligomers were used to functionalize the surface of polyethylene films via an entrapment process. The resultant films yield a temperature responsive surface-solvent interface when immersed in water. The responsiveness of these films...

  11. TECHNICAL GUIDANCE DOCUMENT: THE FABRICATION OF POLYETHYLENE FML FIELD SEAMS

    EPA Science Inventory

    This technical guidance document is meant to augment the numerous construction quality control and construction assurance (CQC and CQA) guidelines that are presently available for high density polyethylene (HDPE) liner installation and inspection.

  12. Creep behavior of 6 micrometer linear low density polyethylene film

    NASA Technical Reports Server (NTRS)

    Simpson, J. M.; Schur, W. W.

    1993-01-01

    Creep tests were performed to provide material characteristics for a 6.4-micron polyethylene film used to construct high altitude balloons. Results suggest simple power law relationships are adequate for stresses below about 4.83 MPa.

  13. DISSIPATION OF FIELD APPLIED HERBICIDES FROM LOW DENSITY POLYETHYLENE MULCH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field studies evaluated dissipation of herbicides from low density polyethylene mulch (LDPM). Herbicide dissipation was measured under dry conditions and following irrigation events. Halosulfuron, paraquat, carfentrazone, glyphosate, and oxyfluorfen were applied to black 1.5-mil LDPM at concentrat...

  14. Irradiation effects in high-density polyethylene Jussi Polvia

    E-print Network

    Nordlund, Kai

    materials since the 1960s [1]. The earliest applications were cross-linking plastic materials, sterilizing polymers like polyethylene can be used to produce heat-shrinkable-plastic films for packaging foods

  15. Extensional viscosity measurements of polyethylene using a melt flow indexer 

    E-print Network

    Moffatt, Scott Gordon

    1999-01-01

    The extensional viscosity of polyethylene melts plays and important role in the processability of the resins. Extensional viscosity is important in processing operations such as film blowing, blow molding, and fiber spinning. The processability...

  16. DELIVERY OF THERAPEUTIC PROTEINS

    PubMed Central

    Pisal, Dipak S.; Kosloski, Matthew P.; Balu-Iyer, Sathy V.

    2009-01-01

    The safety and efficacy of protein therapeutics are limited by three interrelated pharmaceutical issues, in vitro and in vivo instability, immunogenicity and shorter half-lives. Novel drug modifications for overcoming these issues are under investigation and include covalent attachment of poly(ethylene glycol) (PEG), polysialic acid, or glycolic acid, as well as developing new formulations containing nanoparticulate or colloidal systems (e.g. liposomes, polymeric microspheres, polymeric nanoparticles). Such strategies have the potential to develop as next generation protein therapeutics. This review includes a general discussion on these delivery approaches. PMID:20049941

  17. High density polyethylene (HDPE) containers as an alternative to polyethylene terephthalate (PET) bottles for solar disinfection of drinking water in northern region, Ghana

    E-print Network

    Yazdani, Iman

    2007-01-01

    The purpose of this study is to investigate the technical feasibility of high density polyethylene (HDPE) containers as an alternative to polyethylene terephthalate (PET) bottles for the solar disinfection of drinking water ...

  18. The mechanical properties of density graded hemp/polyethylene composites

    NASA Astrophysics Data System (ADS)

    Dauvegis, Raphaël; Rodrigue, Denis

    2015-05-01

    In this work, the production and mechanical characterization of density graded biocomposites based on high density polyethylene and hemp fibres was performed. The effect of coupling agent addition (maleated polyethylene) and hemp content (0-30%) was studied to determine the effect of hemp distribution (graded content) inside the composite (uniform, linear, V and ?). Tensile and flexural properties are reported to compare the structures, especially in terms of their stress-strain behaviors under tensile loading.

  19. A highly efficient polyethylene glycol-mediated transformation method for mushrooms.

    PubMed

    Li, Gang; Li, Ruixue; Liu, Qiuyun; Wang, Qiang; Chen, Min; Li, Baojian

    2006-03-01

    A highly efficient transformation system mediated by polyethylene glycol was developed for the cultivated mushroom Pleurotus ostreatus. Eighty to 180 integrative and stable-resistant colonies appeared per mug of DNA per 10(7) viable protoplasts in a transformation experiment with the hygromycin B phosphotransferase gene (hph), which is about 40-1800 times higher than that previously reported in P. ostreatus. One hundred to 150 transformants emitting green fluorescence were observed per mug of DNA per 10(7) viable protoplasts in a transformation with the green fluorescent protein gene, but green fluorescence disappeared 30 h after transformation, suggesting that the green fluorescent protein gene was only transiently expressed in P. ostreatus. Plasmid pAN7-1 was also transferred into two important cultivated mushrooms, Ganoderma lucidum and Lentinus edodes, and 120-150 and 85-100 transformants per mug of DNA per 10(7) viable protoplasts were obtained, respectively, which is seven to 38 times and 24-28 times greater than previously reported. These data indicate that this new polyethylene glycol-mediated transformation procedure is highly efficient for mushrooms, and could be a useful tool in mushroom improvement by gene engineering. PMID:16499607

  20. Engineering Poly(ethylene glycol) Materials to Promote Cardiogenesis

    NASA Astrophysics Data System (ADS)

    Smith, Amanda Walker

    Heart failure is one of the leading causes of death worldwide, and the current costs of treatment put a significant economic burden on our societies. After an infarction, fibrotic tissue begins to form as part of the heart failure cascade. Current options to slow this process include a wide range of pharmaceutical agents, and ultimately the patient may require a heart transplant. Innovative treatment approaches are needed to bring down costs and improve quality of life. The possibility of regenerating or replacing damaged tissue with healthy cardiomyocytes is generating considerable excitement, but there are still many obstacles to overcome. First, while cell injections into the myocardium have demonstrated slight improvements in cardiac function, the actual engraftment of transplanted cells is very low. It is anticipated that improving engraftment will boost outcomes. Second, cellular differentiation and reprogramming protocols have not yet produced cells that are identical to adult cardiomyocytes, and immunogenicity continues to be a problem despite the advent of autologously derived induced pluripotent stem cells. This dissertation will explore biomaterials approaches to addressing these two obstacles. Tissue engineering scaffolds may improve cell engraftment by providing bioactive factors, preventing cell anoikis, and reducing cell washout by blood flow. Poly(ethylene glycol) (PEG) is often used as a coating to reduce implant rejection because it is highly resistant to protein adsorption. Because fibrosis of a material in contact with the myocardium could cause arrhythmias, PEG materials are highly relevant for cardiac tissue engineering applications. In Chapter 2, we describe a novel method for crosslinking PEG microspheres around cells to form a scaffold for tissue engineering. We then demonstrate that HL-1 cardiomyocyte viability and phenotype are retained throughout the fabrication process and during the first 7 weeks of culture. In the third chapter of the dissertation, we demonstrate that the use of PEG cell culture substrates can improve efficiency of direct reprogramming from fibroblasts to cardiomyocytes for cell transplantation. Standard tissue culture plastic adsorbs proteins from the cell media, increasing experimental variability via non-specific signaling. Because of its protein resistant properties, PEG provides cells with highly specific signals. In addition to improving the efficiency, we found that presentation of RGD peptides stimulated proliferation during reprogramming. Combined, the improvements enabled us to approximately double the number of cardiomyocytes produced by the protocol. In Chapter 4, we explore the effects of 3D culture on the direct reprogramming protocol described in Chapter 3. We demonstrate that the variables involved in 3D culture, including scaffold material, diffusion, cellular remodeling, and scaffold topography, have significant effects on reprogramming efficiency. This chapter provides the groundwork for future studies developing 3D microenvironments for efficient and scalable reprogramming to cardiomyocytes.

  1. Entangled Diffusion in Binary Polyethylene Blends

    NASA Astrophysics Data System (ADS)

    Dirama, N.; Mattice, W. L.; von Meerwall, E.

    2003-10-01

    In continuing support of our Monte-Carlo simulations of self-diffusion in polymers near the entanglement transition we have used the proton pulsed-gradient spin-echo NMR method to augment our previous measurements in n-alkane and polyethylene (PE) melts by studying three series of blends at T = 150 deg. C across the full concentration (c) range. Blends were based on M = 33k PE and contained either n-C50 alkane, M = 1.8k PE, or M = 6.7k PE. The results are again in agreement with our earlier theoretical synthesis(1) involving a smooth transition from Rouse to reptational behavior involving constraint release, accounting for free-volume and tube-constraint host effects which depend on T, M, and c. Tube dilation effects are assumed contained in the constraint-release mechanism; contour-length fluctuations are not considered to affect center-of-mass diffusion. Contrary to our earlier findings, unentangled n-alkanes (n-C50 and even n-C12) do not appear to act as diluents able to delay the onset of entanglements in blends with PE. (1) E. von Meerwall, et al., J. Chem. Phys. 111, 750 (1999); E. von Meerwall, et al., Polymer Prepr. 44, 287 (2003).

  2. Polyethylene Terephthalate May Yield Endocrine Disruptors

    PubMed Central

    Sax, Leonard

    2010-01-01

    Background Recent reports suggest that endocrine disruptors may leach into the contents of bottles made from polyethylene terephthalate (PET). PET is the main ingredient in most clear plastic containers used for beverages and condiments worldwide and has previously been generally assumed not to be a source of endocrine disruptors. Objective I begin by considering evidence that bottles made from PET may leach various phthalates that have been putatively identified as endocrine disruptors. I also consider evidence that leaching of antimony from PET containers may lead to endocrine-disrupting effects. Discussion The contents of the PET bottle, and the temperature at which it is stored, both appear to influence the rate and magnitude of leaching. Endocrine disruptors other than phthalates, specifically antimony, may also contribute to the endocrine-disrupting effect of water from PET containers. Conclusions More research is needed in order to clarify the mechanisms whereby beverages and condiments in PET containers may be contaminated by endocrine-disrupting chemicals. PMID:20368129

  3. Theory of the deformation of aligned polyethylene

    PubMed Central

    Hammad, A.; Swinburne, T. D.; Hasan, H.; Del Rosso, S.; Iannucci, L.; Sutton, A. P.

    2015-01-01

    Solitons are proposed as the agents of plastic and viscoelastic deformation in aligned polyethylene. Interactions between straight, parallel molecules are mapped rigorously onto the Frenkel–Kontorova model. It is shown that these molecular interactions distribute an applied load between molecules, with a characteristic transfer length equal to the soliton width. Load transfer leads to the introduction of tensile and compressive solitons at the chain ends to mark the onset of plasticity at a well-defined yield stress, which is much less than the theoretical pull-out stress. Interaction energies between solitons and an equation of motion for solitons are derived. The equation of motion is based on Langevin dynamics and the fluctuation–dissipation theorem and it leads to the rigorous definition of an effective mass for solitons. It forms the basis of a soliton dynamics in direct analogy to dislocation dynamics. Close parallels are drawn between solitons in aligned polymers and dislocations in crystals, including the configurational force on a soliton. The origins of the strain rate and temperature dependencies of the viscoelastic behaviour are discussed in terms of the formation energy of solitons. A failure mechanism is proposed involving soliton condensation under a tensile load. PMID:26339196

  4. Optimizing the surface density of polyethylene glycol chains by grafting from binary solvent mixtures

    NASA Astrophysics Data System (ADS)

    Arcot, Lokanathan; Ogaki, Ryosuke; Zhang, Shuai; Meyer, Rikke L.; Kingshott, Peter

    2015-06-01

    Polyethylene glycol (PEG) brushes are very effective at controlling non-specific deposition of biological material onto surfaces, which is of paramount importance to obtaining successful outcomes in biomaterials, tissue engineered scaffolds, biosensors, filtration membranes and drug delivery devices. We report on a simple 'grafting to' approach involving binary solvent mixtures that are chosen based on Hansen's solubility parameters to optimize the solubility of PEG thereby enabling control over the graft density. The PEG thiol-gold model system enabled a thorough characterization of PEG films formed, while studies on a PEG silane-silicon system examined the versatility to be applied to any substrate-head group system by choosing an appropriate solvent pair. The ability of PEG films to resist non-specific adsorption of proteins was quantitatively assessed by full serum exposure studies and the binary solvent strategy was found to produce PEG films with optimal graft density to efficiently resist protein adsorption.

  5. Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films.

    PubMed

    Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood

    2015-03-30

    In this work, low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) films are prepared with the aim of obtaining environmentally friendly materials containing high TPS content with required packaging properties. Blending of LDPE/LLDPE (70/30 wt/wt) with 5-20 wt% of TPS and 3 wt% of PE-grafted maleic anhydride (PE-g-MA) is performed in a twin-screw extruder, followed by the blowing process. Differential scanning calorimetric results indicate starch has more pronounced effect on crystallization of LLDPE than LDPE. Scanning electron micrograph shows a fairly good dispersion of TPS in PE matrices. Fourier transfer infrared spectra confirm compatibility between polymers using PE-g-MA as the compatibilizer. Storage modulus, loss modulus and complex viscosity increase with incorporation of starch. Tensile strength and elongation-at-break decrease from 18 to 10.5 MPa and 340 to 200%, respectively when TPS increases from 5 to 20%. However, the required mechanical properties for packaging applications are attained when 15 wt% starch is added, as specified in ASTM D4635. Finally 12% increase in water uptake is achieved with inclusion of 15 wt% starch. PMID:25563952

  6. Effect of amine functionalized polyethylene on clay-silver dispersion for polyethylene nanocomposites

    NASA Astrophysics Data System (ADS)

    Sánchez-Valdes, S.; Ibarra-A, M. C.; Ramírez-V, E.; Ramos-V, L. F.; Martinez-C, J. G.; Romero-G, J.; Ledezma-P, A. S.; Rodriguez-F, O. S.

    2014-08-01

    The compatibilization provided by maleic anhydride (MA) and 2-[2-(dimethylamino)-ethoxy] ethanol (DMAE) functionalized polyethylene for forming polyethylene-based nanocomposites was studied and compared. MA was grafted into PE by melt mixing to obtain PEgMA (compatibilizer 1), thereafter, PEgMA was reacted with DMAE and an antioxidant also by melt mixing to obtain PAgDMAE (compatibilizer 2). These compatibilizers were reacted using ultrasound with a solution of AgNO3 0.04 M and Ethylene glycol. Ammonium hydroxide was added in a ratio of 2:1 molar with respect to silver nitrate. These silver coated compatibilizers were mixed with PE and nano-clay (Cloisite I28E), thus forming the different hybrid PE-clay-silver nanocomposites. FTIR confirmed the formation of these two compatibilizers. All the compatibilized nanocomposites had better filler (clay and silver) dispersion and exfoliation compared to the uncompatibilized PE nanocomposites. X-ray diffraction, mechanical and antimicrobial properties attained showed that the PEgDMAE produced the better dispersed PE, clay and silver nanocomposites. The obtained nanocomposites showed outstanding antimicrobial properties against bacteria, Escherichia coli and fungus, Aspergillus niger. It is concluded that the PEgDMAE offers an outstanding capability for preparing nanocomposites with highly exfoliated and dispersed filler into the PE matrix.

  7. Proteomic Analysis of Lonicera japonica Thunb. Immature Flower Buds Using Combinatorial Peptide Ligand Libraries and Polyethylene Glycol Fractionation.

    PubMed

    Zhu, Wei; Xu, Xiaobao; Tian, Jingkui; Zhang, Lin; Komatsu, Setsuko

    2016-01-01

    Lonicera japonica Thunb. flower is a well-known medicinal plant that has been widely used for the treatment of human disease. To explore the molecular mechanisms underlying the biological activities of L. japonica immature flower buds, a gel-free/label-free proteomic technique was used in combination with combinatorial peptide ligand libraries (CPLL) and polyethylene glycol (PEG) fractionation for the enrichment of low-abundance proteins and removal of high-abundance proteins, respectively. A total of 177, 614, and 529 proteins were identified in crude protein extraction, CPLL fractions, and PEG fractions, respectively. Among the identified proteins, 283 and 239 proteins were specifically identified by the CPLL and PEG methods, respectively. In particular, proteins related to the oxidative pentose phosphate pathway, signaling, hormone metabolism, and transport were highly enriched by CPLL and PEG fractionation compared to crude protein extraction. A total of 28 secondary metabolism-related proteins and 25 metabolites were identified in L. japonica immature flower buds. To determine the specificity of the identified proteins and metabolites for L. japonica immature flower buds, Cerasus flower buds were used, which resulted in the abundance of hydroxymethylbutenyl 4-diphosphate synthase in L. japonica immature flower buds being 10-fold higher than that in Cerasus flower buds. These results suggest that proteins related to secondary metabolism might be responsible for the biological activities of L. japonica immature flower buds. PMID:26573373

  8. Wear of highly crosslinked polyethylene acetabular components

    PubMed Central

    Callary, Stuart A; Solomon, Lucian B; Holubowycz, Oksana T; Campbell, David G; Munn, Zachary; Howie, Donald W

    2015-01-01

    Background and purpose Wear rates of highly crosslinked polyethylene (XLPE) acetabular components have varied considerably between different published studies. This variation is in part due to the different techniques used to measure wear and to the errors inherent in measuring the relatively low amounts of wear in XLPE bearings. We undertook a scoping review of studies that have examined the in vivo wear of XLPE acetabular components using the most sensitive method available, radiostereometric analysis (RSA). Methods A systematic search of the PubMed, Scopus, and Cochrane databases was performed to identify published studies in which RSA was used to measure wear of XLPE components in primary total hip arthroplasty (THA). Results 18 publications examined 12 primary THA cohorts, comprising only 260 THAs at 2–10 years of follow-up. The mean or median proximal wear rate reported ranged from 0.00 to 0.06 mm/year. However, differences in the manner in which wear was determined made it difficult to compare some studies. Furthermore, differences in RSA methodology between studies, such as the use of supine or standing radiographs and the use of beaded or unbeaded reference segments, may limit future meta-analyses examining the effect of patient and implant variables on wear rates. Interpretation This scoping review confirmed the low wear rates of XLPE in THA, as measured by RSA. We make recommendations to enhance the standardization of reporting of RSA wear results, which will facilitate early identification of poorly performing implants and enable a better understanding of the effects of surgical and patient factors on wear. PMID:25301435

  9. Modeling uptake of hydrophobic organic contaminants into polyethylene passive samplers.

    PubMed

    Thompson, Jay M; Hsieh, Ching-Hong; Luthy, Richard G

    2015-02-17

    Single-phase passive samplers are gaining acceptance as a method to measure hydrophobic organic contaminant (HOC) concentration in water. Although the relationship between the HOC concentration in water and passive sampler is linear at equilibrium, mass transfer models are needed for nonequilibrium conditions. We report measurements of organochlorine pesticide diffusion and partition coefficients with respect to polyethylene (PE), and present a Fickian approach to modeling HOC uptake by PE in aqueous systems. The model is an analytic solution to Fick's second law applied through an aqueous diffusive boundary layer and a polyethylene layer. Comparisons of the model with existing methods indicate agreement at appropriate boundary conditions. Laboratory release experiments on the organochlorine pesticides DDT, DDE, DDD, and chlordane in well-mixed slurries support the model's applicability to aqueous systems. In general, the advantage of the model is its application in the cases of well-agitated systems, low values of polyethylene-water partioning coefficients, thick polyethylene relative to the boundary layer thickness, and/or short exposure times. Another significant advantage is the ability to estimate, or at least bound, the needed exposure time to reach a desired CPE without empirical model inputs. A further finding of this work is that polyethylene diffusivity does not vary by transport direction through the sampler thickness. PMID:25607420

  10. 76 FR 22867 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film (PET Film) from...following events have taken place. See Polyethylene Terephthalate Film, Sheet, and...

  11. 78 FR 29700 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film (PET Film) from...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  12. 76 FR 1135 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ...Trade Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip...review of the antidumping duty order on polyethylene terephthalate film, sheet, and...

  13. 75 FR 70901 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ...Trade Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping order on polyethylene terephthalate film, sheet and strip...the Republic of Korea (Korea). See Polyethylene Terephthalate Film, Sheet, and...

  14. 77 FR 20357 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ...Trade Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip...review of the antidumping duty order on polyethylene terephthalate film (PET Film) from...1\\ See Polyethylene Terephthalate Film, Sheet, and...

  15. 75 FR 75454 - Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for the Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-03

    ...A-549-821] Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for...antidumping duty order on polyethylene retail carrier bags from Thailand. See Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of...

  16. Interfacial interactions between polyethylene matrix and clay layers in polyethylene/clay nanocomposites

    NASA Astrophysics Data System (ADS)

    Abu-Zurayk, R.

    2015-10-01

    Polyethylene/clay nanocomposites were prepared as blown films using different formulae (clay contents (4 and 6 wt%) and compatibilizer/clay ratio (1/2, 1.0, 2.0)). Structure and mechanical behaviour were tested. It was found that blown film extrusion process decreased the tactoids size and consequently enhanced the exfoliation degree of the clay layers inside the polymer matrix, which is due to the elongational stress during extrusion. Addition of clay had some effects on mechanical behaviour. There was an increase of yield strength (max 32%). Yield strength is related to the interfacial interaction between the polymer and the clay layers in the nanocomposites, which would be enhanced by enhancing the compatibility between polymer and clay layers. Correlation analysis showed good correlation between compatibility and interfacial interaction parameters, and between parameters of interfacial interaction, structure and yield strength.

  17. [In-vivo wear of the slide combinations ceramics-polyethylene as opposed to metal-polyethylene].

    PubMed

    Zichner, L; Lindenfeld, T

    1997-02-01

    The present study deals with long-term dimensional changes in cemented Müller-type total hip endoprostheses. Creep and wear contribute to different extents to the dimensional changes in polyethylene. The total amount of polyethylene wear is represented by the displacement of the femoral head into the socket. Within the first postoperative years, the head shifts up to a relatively high rate of about 0.5 mm per year. This rate diminishes after 5 years to an average of about 0.1 mm (ceramics) and 0.2 mm (metal) per year. Values exceeding 0.2 mm per year for the shift of the femoral head are considered to be unfavourable with regard to a probable loosening of the prosthesis. In this study we determined the orientation of the centre of the prosthetic head in relation to the wire marker of the polyethylene cup, comprising in all 369 total hip prostheses. After an average of 77 months, 96% of the prostheses with ceramic heads (n = 109) had a wear rate of less than 0.2 mm per year. Using metal heads (Protasul-2 and Protasul-10) this rate could only be measured in 71% (n = 109) of the prostheses (61.5 months). The combination ceramics-polyethylene produces half of the total amount of wear produced by metal-polyethylene. Younger patients should preferably be treated with a ceramic ballhead. PMID:9157352

  18. Space radiation transport properties of polyethylene-based composites

    NASA Technical Reports Server (NTRS)

    Kaul, R. K.; Barghouty, A. F.; Dahche, H. M.

    2004-01-01

    Composite materials that can serve as both effective shielding materials against cosmic-ray and energetic solar particles in deep space, as well as structural materials for habitat and spacecraft, remain a critical and mission enabling component in mission planning and exploration. Polyethylene is known to have excellent shielding properties due to its low density, coupled with high hydrogen content. Polyethylene-fiber reinforced composites promise to combine this shielding effectiveness with the required mechanical properties of structural materials. Samples of polyethylene-fiber reinforced epoxy matrix composite 1-5 cm thick were prepared at the NASA Marshall Space Flight Center and tested against a 500 MeV/nucleon Fe beam at the HIMAC facility of NIRS in Chiba, Japan. This paper presents measured and calculated results for the radiation transport properties of these samples.

  19. Radiation Transport Properties of Polyethylene-Fiber Composites

    NASA Technical Reports Server (NTRS)

    Kaul, Raj K.; Barghouty, A. F.; Dahche, H. M.

    2003-01-01

    Composite materials that can both serve as effective shielding materials against cosmic-ray and energetic solar particles in deep space as well as structural materials for habitat and spacecraft remain a critical and mission enabling piece in mission planning and exploration. Polyethylene is known to have excellent shielding properties due to its low density coupled with high hydrogen content. Polyethylene fiber reinforced composites promise to combine this shielding effectiveness with the required mechanical properties of structural materials. Samples of Polyethylene-fiber reinforced epoxy matrix composite 1-5 cm thick were prepared at NASA's Marshall Space Flight Center and tested against 500 MeV/nucleon Fe beam at the HIMAC facility of NIRS in Chiba, Japan. This paper presents measured and calculated results for the radiation transport properties of these samples.

  20. Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Brullot, W.; Reddy, N. K.; Wouters, J.; Valev, V. K.; Goderis, B.; Vermant, J.; Verbiest, T.

    2012-06-01

    Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles were obtained by a facile protocol and thoroughly characterized. Superparamagnetic iron oxide nanoparticles synthesized using a modified forced hydrolysis method were functionalized with polyethylene glycol silane (PEG silane), precipitated and dried. These functionalized particles are dispersable in a range of solvents and concentrations depending on the desired properties. Examples of tunable properties are magnetic behavior, optical and magneto-optical response, thermal features and rheological behavior. As such, PEG silane functionalized particles represent a platform for the development of new materials that have broad applicability in e.g. biomedical, industrial or photonic environments. Magnetic, optical, magneto-optical, thermal and rheological properties of several ferrofluids based on PEG coated particles with different concentrations of particles dispersed in low molecular mass polyethylene glycol were investigated, establishing the applicability of such materials.

  1. Injectable silk-polyethylene glycol hydrogels.

    PubMed

    Wang, Xiaoqin; Partlow, Benjamin; Liu, Jian; Zheng, Zhaozhu; Su, Bo; Wang, Yansong; Kaplan, David L

    2015-01-01

    Silk hydrogels for tissue repair are usually pre-formed via chemical or physical treatments from silk solutions. For many medical applications, it is desirable to utilize injectable silk hydrogels at high concentrations (>8%) to avoid surgical implantation and to achieve slow in vivo degradation of the gel. In the present study, injectable silk solutions that formed hydrogels in situ were generated by mixing silk with low-molecular-weight polyethylene glycol (PEG), especially PEG300 and 400 (molecular weight 300 and 400g mol(-1)). Gelation time was dependent on the concentration and molecular weight of PEG. When the concentration of PEG in the gel reached 40-45%, gelation time was less than 30min, as revealed by measurements of optical density and rheological studies, with kinetics of PEG400 faster than PEG300. Gelation was accompanied by structural changes in silk, leading to the conversion from random coil in solution to crystalline ?-sheets in the gels, based on circular dichroism, attenuated total reflection Fourier transform infrared spectroscopy and X-ray diffraction. The modulus (127.5kPa) and yield strength (11.5kPa) determined were comparable to those of sonication-induced hydrogels at the same concentrations of silk. The time-dependent injectability of 15% PEG-silk hydrogel through 27G needles showed a gradual increase of compression forces from ?10 to 50N within 60min. The growth of human mesenchymal stem cells on the PEG-silk hydrogels was hindered, likely due to the presence of PEG, which grew after a 5 day delay, presumably while the PEG solubilized away from the gel. When 5% PEG-silk hydrogel was subcutaneously injected in rats, significant degradation and tissue in-growth took place after 20 days, as revealed by ultrasound imaging and histological analysis. No significant inflammation around the gel was observed. The features of injectability, slow degradation and low initial cell attachment suggests that these PEG-silk hydrogels are of interest for many biomedical applications, such as anti-fouling and anti-adhesion. PMID:25449912

  2. 76 FR 42113 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ...COMMERCE International Trade Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's...for the preliminary results of the administrative review of polyethylene terephthalate film, sheet, and strip (``PET...

  3. Synthesis and elaboration of polyethylene surfaces modified via anionic grafting chemistry 

    E-print Network

    Bandella, Ashok Krishangopal

    1996-01-01

    called entrapment functionalization. These anionic precursors are located mainly on the surface of polyethylene films which can be easily deprotonated by n-BuLi to generate diarylanions at the polyethylene film surface. Poly(tert-butyl acrylate...

  4. Crystallographic texture evolution in high-density polyethylene during uniaxial tension

    E-print Network

    Garmestani, Hamid

    generation of metallocene- type catalysts [3]. Based on molecular structure, the polyethylenes are divided the catalyst and/or the polymerization process, polyethylenes can be obtained having markedly different chain

  5. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Intracardiac patch or pledget made of polypropylene, polyethylene...Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene, polyethylene...a) Identification. An intracardiac patch or pledget made of polypropylene,...

  6. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Intracardiac patch or pledget made of polypropylene, polyethylene...Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene, polyethylene...a) Identification. An intracardiac patch or pledget made of polypropylene,...

  7. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 false Intracardiac patch or pledget made of polypropylene, polyethylene...Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene, polyethylene...a) Identification. An intracardiac patch or pledget made of polypropylene,...

  8. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Diethylene glycol, polymer with diisocyanatoalkane, polyethylene... § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene...identified generically as diethylene glycol, polymer with diisocyanatoalkane,...

  9. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Diethylene glycol, polymer with diisocyanatoalkane, polyethylene... § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene...identified generically as diethylene glycol, polymer with diisocyanatoalkane,...

  10. 75 FR 25207 - Polyethylene Retail Carrier Bags From Malaysia: Extension of Time Limit for Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ...Trade Administration A-557-813 Polyethylene Retail Carrier Bags From Malaysia: Extension of Time Limit for Preliminary Results...of the antidumping duty order on polyethylene retail carrier bags from Malaysia for the period August 1, 2008, through July...

  11. 76 FR 26241 - Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ...Administration [A-549-821] Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for Preliminary Results...of the antidumping duty order on polyethylene retail carrier bags from Thailand for the period August 1, 2009, through July...

  12. 78 FR 50376 - Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ...Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...polyethylene retail carrier bags (PRCBs) from Thailand. The period of review (POR) is August...antidumping duty order on PRCBs from Thailand.\\1\\ We invited interested...

  13. 76 FR 68137 - Polyethylene Retail Carrier Bags From Thailand: Amended Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ...Polyethylene Retail Carrier Bags From Thailand: Amended Final Results of Antidumping...Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...by applying this ratio to Landblue (Thailand) Co., Ltd.'s (Landblue)...

  14. Synthesis and Characterization of Amphiphilic Poly(ethylene oxide)-block-poly(hexyl methacrylate)

    E-print Network

    Gruner, Sol M.

    Synthesis and Characterization of Amphiphilic Poly(ethylene oxide)-block-poly(hexyl methacrylate University, Ithaca, NY 14853, USA Keywords: amphiphilic block copolymers; anionic polymerization; ATRP; microphase separation Introduction Poly(ethylene oxide) (PEO) based amphiphilic block co- polymers exhibit

  15. Irradiation of linear polyethylene - Partitioning between sol and gel.

    NASA Technical Reports Server (NTRS)

    Rijke, A. M.; Mandelkern, L.

    1971-01-01

    Investigation of the importance of chain-scission processes and of the applicability of the general theory of network formation to polyethylene with respect to critical conditions for gelation, using molecular weight fractions of linear polyethylene irradiated at 133 C. The partitioning between sol and gel was found to adhere to the theory just beyond the gel point. Deviations from theory occurred as the irradiation dosage was increased. It was concluded that main-chain scission at the temperatures concerned is not a significant process.

  16. Molecularly uniform poly(ethylene glycol) certified reference material

    NASA Astrophysics Data System (ADS)

    Takahashi, Kayori; Matsuyama, Shigetomo; Kinugasa, Shinichi; Ehara, Kensei; Sakurai, Hiromu; Horikawa, Yoshiteru; Kitazawa, Hideaki; Bounoshita, Masao

    2015-02-01

    A certified reference material (CRM) for poly(ethylene glycol) with no distribution in the degree of polymerization was developed. The degree of polymerization of the CRM was accurately determined to be 23. Supercritical fluid chromatography (SFC) was used to separate the molecularly uniform polymer from a standard commercial sample with wide polydispersity in its degree of polymerization. Through the use of a specific fractionation system coupled with SFC, we are able to obtain samples of poly(ethylene glycol) oligomer with exact degrees of polymerization, as required for a CRM produced by the National Metrology Institute of Japan.

  17. Polyethylene composites containing a phase change material having a C14 straight chain hydrocarbon

    DOEpatents

    Salyer, Ival O. (Dayton, OH)

    1987-01-01

    A composite useful in thermal energy storage, said composite being formed of a polyethylene matrix having a straight chain alkyl hydrocarbon incorporated therein, said polyethylene being crosslinked to such a degree that said polyethylene matrix is form stable and said polyethylene matrix is capable of absorbing at least 10% by weight of said straight chain alkyl hydrocarbon; the composite is useful in forming pellets or sheets having thermal energy storage characteristics.

  18. Divinyl-end-functionalized polyethylenes: ready access to a range of telechelic polyethylenes through thiol-ene reactions.

    PubMed

    Norsic, Sebastien; Thomas, Coralie; D'Agosto, Franck; Boisson, Christophe

    2015-04-01

    Telechelic ?,?-iodo-vinyl-polyethylenes (Vin-PE-I) were obtained by catalytic ethylene polymerization in the presence of [(C5 Me5 )2 NdCl2 Li(OEt2 )2 ] in combination with a functionalized chain-transfer agent, namely, di(10-undecenyl)magnesium, followed by treatment of the resulting di(vinylpolyethylenyl)magnesium compounds ((vinyl-PE)2 Mg) with I2 . The iodo-functionalized vinylpolyethylenes (Vin-PE-I) were transformed into unique divinyl-functionalized polyethylenes (Vin-PE-Vin) by simple treatment with tBuOK in toluene at 95?°C. Thiol-ene reactions were then successfully performed on Vin-PE-Vin with functionalized thiols in the presence of AIBN. A range of homobifunctional telechelic polyethylenes were obtained on which a hydroxy, diol, carboxylic acid, amine, ammonium chloride, trimethoxysilyl, chloro, or fluoroalkyl group was installed quantitatively at each chain end. PMID:25688747

  19. Wood plastic composites based on microfibrillar blends of high density polyethylene/poly(ethylene terephthalate)

    E-print Network

    Wood plastic composites based on microfibrillar blends of high density polyethylene January 2010 Keywords: Wood plastic composites Poly(ethylene terephthalate) Polyethylene Extrusion a b into wood plastic composites through a two-step reactive extrusion technology. Wood flour was added into pre

  20. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2768 Sorbitol SX850, or equivalent) 12 percent in H2O by weight on 60-80 mesh nonacid washed... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (mean molecular weight 200-9... Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene...

  1. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  2. Study On Temperature Distribution In T Fittings - Polyethylene Natural Gas Pipes Assemblies

    NASA Astrophysics Data System (ADS)

    Avrigean, Eugen

    2015-09-01

    The present paper intends to approach theoretically and experimentally an important topic concerning the operational safety of the polyethylene pipes used in natural gas distribution. We discuss the influence of temperature in the high density polyethylene elbows during welding to the polyethylene pipes.

  3. Use of cotton gin trash and compatibilizers in polyethylene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ginning of cotton produces 15-42% of foreign materials, called “cotton gin trash”, including cotton burr, stems, leaf fragment, and dirt. In this work we examined the mechanical properties of composites of low density polyethylene (LDPE) and cotton burr. The burr was ground into powder, and se...

  4. Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region

    E-print Network

    Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region Zhong­Hui Duan computed, modeling the chains as random walks on a diamond lattice with two absorbing boundaries four neighbors --- the lattice of the diamond (also silicon) crystal. We shall model the chains

  5. Herbicide dissipation from low density polyethylene mulch utilizing analytical techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Georgia, most of the low density polyethylene mulch (LDPM) is laid for spring vegetable production followed by a second crop in the autumn, with a potential third crop the following spring. Between these vegetable plantings, farmers often use contact and residual herbicides to control weeds that ...

  6. SECURING CONTAINERIZED HAZARDOUS WASTES WITH WELDED POLYETHYLENE ENCAPSULATES

    EPA Science Inventory

    Full-scale encapsulation of 208-liter (55-gal) drums was studied as a means for managing corroding containers of hazardous wastes in the field and rendering them suitable for transport and safe deposit within a final disposal site such as a landfill. Polyethylene (PE) receivers w...

  7. Polymer geometry and Li+ conduction in poly(ethylene oxide)

    E-print Network

    Averbuch, Amir

    Polymer geometry and Li+ conduction in poly(ethylene oxide) L. Gitelman a , M. Israeli b, , A: Lithium battery Polymer molecule Brownian motion Simulation Conductivity PEO a b s t r a c t We study of the amorphous PE structure is increased by mechanical stretching due to the unraveling of loops in the polymer

  8. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (400) monolaurate. 178.3760 Section 178.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and...

  9. Adsorption of Polyethylene from Solution onto Starch Film Surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since starch adsorbs onto polyethylene (PE) surfaces from cooled solutions of jet cooked starch, this study was carried out to determine whether adsorption of PE onto hydrophilic starch film surfaces would also take place if starch films were placed in hot solutions of PE in organic solvents, and th...

  10. Preventing oxidation of iron sulfide minerals by polyethylene polyamines

    E-print Network

    Belzile, Nelson

    blasting and mineral processing can cause significant surface oxi- dation of sulfide rock piles, which can processes of sulfide minerals still remains an important issue for both mineral extraction and environmentalPreventing oxidation of iron sulfide minerals by polyethylene polyamines Yu-Wei Chen a,*, Yuerong

  11. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated...

  12. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and...

  13. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene resins, carboxyl modified. 177.1600 Section 177.1600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and...

  14. APPLICATION OF HYDROPHILIC STARCH-BASED COATINGS TO POLYETHYLENE SURFACES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coatings were applied to polyethylene film surfaces by spraying formulations prepared from a jet cooked dispersion of waxy cornstarch, a water-based epoxy resin, a wax emulsion, and a surfactant. Although the starch component separated rapidly from the coating when the film was placed in water at r...

  15. Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process

    E-print Network

    reported that the two-step process was better for the manufacturing of air-formed woodWood-Fiber/High-Density-Polyethylene Composites: Compounding Process J. Z. Lu,1 Q. Wu,1 I. I online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: The compounding process directly

  16. Vol. 79, No. 2, 2002 261 Tensile Properties of Extruded Corn Protein

    E-print Network

    Vol. 79, No. 2, 2002 261 Tensile Properties of Extruded Corn Protein Low-Density Polyethylene Films products, petroleum conservation, and con- servation of landfill space. Research in protein films has focused on the production of solvent- cast films. Corn and wheat protein (Aydt et al 1991; Herald et al

  17. Solvent effect in the polyethylene recovery from multilayer postconsumer aseptic packaging.

    PubMed

    Cervantes-Reyes, Alejandro; Núñez-Pineda, Alejandra; Barrera-Díaz, Carlos; Varela-Guerrero, Víctor; Martínez-Barrera, Gonzalo; Cuevas-Yañez, Erick

    2015-04-01

    Polyethylene films were separated and recovered from polyethylene-aluminum composites derived from recycling multilayer postconsumer aseptic packaging. A brief study about the separation process by dissolving PE-aluminum (PE-Al) composites into a series of organic solvents with a combination of time and temperature is presented. Through this procedure, 56% polyethylene is recovered from this kind of composites in optimized conditions. DSC and TGA studies were performed to determine the thermal stability of recovered polyethylene films and to establish a comparison with a PE reference commercial product, demonstrating that recovered polyethylene films kept their thermal properties. PMID:25681948

  18. Liquid-Liquid Phase Transition of Protein Aqueous Solutions Isothermally Induced by Protein Cross-Linking

    E-print Network

    Benedek, George B.

    of protein-rich liquid droplets for bovine serum albumin and chicken egg lysozyme at 25 °C. These dropletsH, polyethylene glycol, and salt concentrations can be used to favor LLPS relative to aggregation. Although is quite common in industrial polymerization processes.8 The observed phase separa- tion is related

  19. Comparison of Polyethylene Glycol-Electrolyte Solution vs Polyethylene Glycol-3350 for the Treatment of Fecal Impaction in Pediatric Patients

    PubMed Central

    Boles, Erin E.; Gaines, Cameryn L.

    2015-01-01

    OBJECTIVES: The objective of this study was to evaluate the safety and efficacy of polyethylene glycol-electrolyte solution vs polyethylene glycol-3350 for the treatment of fecal impaction in pediatric patients. METHODS: A retrospective, observational, institutional review board–approved study was conducted over a 1-year time period. Patients were included in the study if they were admitted to the hospital with a diagnosis of fecal impaction or constipation and were treated with either polyethylene glycol-electrolyte solution (PEG-ES) or polyethylene glycol-3350 (PEG-3350). Patients were excluded if they were discharged prior to resolution of treatment and/or did not receive PEG-ES or PEG-3350. RESULTS: Fifty-one patients (ranging in age from 1 month to 15 years) were evaluated: 23 patients received PEG-ES and 28 patients received PEG-3350. Sex, race, age, and weight were not statistically different between the 2 groups. Resolution of fecal impaction was not significantly different between PEG-ES vs PEG-3350 (87% and 86%, respectively; p = 0.87). There was only 1 reported side effect with PEG-3350, vs 11 reported side effects with PEG-ES (p < 0.01). CONCLUSIONS: Theses results suggest that PEG-3350 is as effective as PEG-ES for the treatment of fecal impaction in pediatric patients and is associated with fewer side effects. PMID:26170773

  20. Poly(ethylene glycol)-containing hydrogels modulate ?-defensin release from polymorphonuclear leukocytes and monocyte recruitment.

    PubMed

    Lieberthal, Tyler Jacob; Cohen, Hannah Caitlin; Kao, W John

    2015-12-01

    Polymorphonuclear leukocytes (PMNs) release granule proteins as the first line of defense against bacteria and set up chemotactic gradients that result in monocyte infiltration to the site of injury. Although well established, the role of biomaterials in regulating adherent PMN degranulation and subsequent PMN-monocyte paracrine interactions is less clear. The aim of this study was to determine how biomaterials affect the degranulation of selected biomarkers and downstream monocyte adhesion and transendothelial migration. Poly(ethylene glycol) (PEG)-containing hydrogels (PEG and an interpenetrating network of PEG and gelatin) promote the release of the ?-defensins human neutrophil peptides 1-3, but not azurocidin or monocyte chemotactic protein-1. Although human neutrophil peptides 1-3 are monocyte chemoattractants, no subsequent effects on monocyte transmigration are observed in static conditions. Under flow conditions, monocyte adhesion on human umbilical vein endothelial cells stimulated with tumor necrosis factor-? is elevated in the presence of granule proteins from PMNs adherent on polydimethylsiloxane, but not from PMNs cultured on PEG hydrogels. These results suggest that PEG promotes PMN antimicrobial capacity without enhanced monocyte recruitment. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3772-3780, 2015. PMID:26053326

  1. Proteomic and phosphoproteomic analysis of polyethylene glycol-induced osmotic stress in root tips of common bean (Phaseolus vulgaris L.)

    PubMed Central

    Horst, Walter Johannes

    2013-01-01

    Previous studies have shown that polyethylene glycol (PEG)-induced osmotic stress (OS) reduces cell-wall (CW) porosity and limits aluminium (Al) uptake by root tips of common bean (Phaseolus vulgaris L.). A subsequent transcriptomic study suggested that genes related to CW processes are involved in adjustment to OS. In this study, a proteomic and phosphoproteomic approach was applied to identify OS-induced protein regulation to further improve our understanding of how OS affects Al accumulation. Analysis of total soluble proteins in root tips indicated that, in total, 22 proteins were differentially regulated by OS; these proteins were functionally categorized. Seventy-seven per- cent of the total expressed proteins were involved in metabolic pathways, particularly of carbohydrate and amino acid metabolism. An analysis of the apoplastic proteome revealed that OS reduced the level of five proteins and increased that of seven proteins. Investigation of the total soluble phosphoproteome suggested that dehydrin responded to OS with an enhanced phosphorylation state without a change in abundance. A cellular immunolocalization analysis indicated that dehydrin was localized mainly in the CW. This suggests that dehydrin may play a major protective role in the OS-induced physical breakdown of the CW structure and thus maintenance of the reversibility of CW extensibility during recovery from OS. The proteomic and phosphoproteomic analyses provided novel insights into the complex mechanisms of OS-induced reduction of Al accumulation in the root tips of common bean and highlight a key role for modification of CW structure. PMID:24123251

  2. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Boric acid (H3BO3), mixed esters with polyethylene...Chemical Substances § 721.1729 Boric acid (H3BO3), mixed esters with polyethylene...chemical substance identified as boric acid (H3 BO3 ), mixed...

  3. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Boric acid (H3BO3), mixed esters with polyethylene...Chemical Substances § 721.1729 Boric acid (H3BO3), mixed esters with polyethylene...chemical substance identified as boric acid (H3 BO3 ), mixed...

  4. Strength of Polyethylene, Polypropylene and Polystyrene Behind a Shock Front

    NASA Astrophysics Data System (ADS)

    Tyler, C. E.; Bourne, N. K.; Millett, J. C. F.

    2007-12-01

    There is a recent interest in the response of thermoplastics to shock. Previous work on three simple hydrocarbons has indicated that the shear strength increases with the complexity of the side group. Strength values have been calculated using lateral stress measurements with manganin gauges that have been recalibrated for use in the low stress regime. The present work aims to investigate the effect of the configuration of the thermoplastic's chain when side groups are added. Results show that whilst polyethylene has the lowest shear strength, polypropylene and polystyrene have similar values. In all cases the strength of polymer increases with time after the shock has past. As the applied stress increases, polystrene and polypropylene strengthen to a higher degree when compared with polyethylene. Explanations are offered in terms of microstructure and tacticity of the chain.

  5. Study of the Auger line shape of polyethylene and diamond

    NASA Technical Reports Server (NTRS)

    Dayan, M.; Pepper, S. V.

    1984-01-01

    The KVV Auger electron line shapes of carbon in polyethylene and diamond have been studied. The spectra were obtained in derivative form by electron beam excitation. They were treated by background subtraction, integration and deconvolution to produce the intrinsic Auger line shape. Electron energy loss spectra provided the response function in the deconvolution procedure. The line shape from polyethylene is compared with spectra from linear alkanes and with a previous spectrum of Kelber et al. Both spectra are compared with the self-convolution of their full valence band densities of states and of their p-projected densities. The experimental spectra could not be understood in terms of existing theories. This is so even when correlation effects are qualitatively taken into account account to the theories of Cini and Sawatzky and Lenselink.

  6. Hyperthermal atomic oxygen reactions with kapton and polyethylene

    SciTech Connect

    Cross, J.B. ); Koontz, S.L. . Lyndon B. Johnson Space Center); Gregory, J.C.; Edgell, M.J. . Dept. of Chemistry)

    1990-01-01

    Gas phase reaction products produced by the interaction of high kinetic energy (1--3 eV) {sup 3}P ground state atomic oxygen (AO) with polyethylene and kapton were found to be H{sub 2}, H{sub 2}O, CO, and CO{sub 2} with NO being a possible secondary product from kapton. Hydrogen abstraction at high AO kinetic energy is postulated to be the key reaction controlling the erosion rate of kapton and polyethylene. An Arrhenius-like expression having an activation barrier of 0.4 eV can be fit to the data, which suggests that the rate limiting step in the AO/kapton reaction mechanism can be overcome by translational energy. 16 refs., 13 figs.

  7. Hyperthermal atomic oxygen reactions with kapton and polyethylene. [in LEO

    NASA Technical Reports Server (NTRS)

    Cross, J. B.; Koontz, S. L.; Gregory, J. C.; Edgell, M. J.

    1990-01-01

    Gas phase reaction products produced by the interaction of high kinetic energy (1-3 eV) 3p ground state atomic oxygen (AO) with polyethylene and kapton were found to be H2, H2O, CO, and CO2 with NO being a possible secondary product from kapton. Hydrogen abstraction at high AO kinetic energy is postulated to be the key reaction controlling the erosion rate of kapton and polyethylene. An Arrhenius-like expression having an activation barrier of 0.4 eV can be fit to the data, which suggests that the rate limiting step in the AO/kapton reaction mechanism can be overcome by translational energy.

  8. Polyethylene encapsulation full-scale technology demonstration. Final report

    SciTech Connect

    Kalb, P.D.; Lageraaen, P.R.

    1994-10-01

    A full-scale integrated technology demonstration of a polyethylene encapsulation process, sponsored by the US Department of Energy (DOE) Office of Technology Development (OTD), was conducted at the Environmental & Waste Technology Center at Brookhaven National Laboratory (BNL.) in September 1994. As part of the Polymer Solidification National Effort, polyethylene encapsulation has been developed and tested at BNL as an alternative solidification technology for improved, cost-effective treatment of low-level radioactive (LLW), hazardous and mixed wastes. A fully equipped production-scale system, capable of processing 900 kg/hr (2000 lb/hr), has been installed at BNL. The demonstration covered all facets of the integrated processing system including pre-treatment of aqueous wastes, precise feed metering, extrusion processing, on-line quality control monitoring, and process control.

  9. Polyethylene Glycol (PEG)-Induced Anaphylactic Reaction During Bowel Preparation

    PubMed Central

    2015-01-01

    Barium enema is used to screen patients with gastrointestinal bleeding who do not want to undergo colonoscopy. Polyethylene glycol (PEG) is usually the bowel preparation of choice. Few allergic reactions from this product have been reported; these include urticaria, angioedema, and anaphylaxis. Reactions are thought to result from a small amount of PEG crossing the intestinal mucosa, which, in some patients, is sufficient to provoke an anaphylactic reaction. PMID:26203443

  10. Tensile properties of sand-reinforced low density polyethylene

    SciTech Connect

    Kandeil, A.Y.; Zahran, R.R.

    1995-10-01

    Sand-reinforced low density polyethylene samples were prepared using injection molding. The effect of some processing and structural parameters on the tensile properties of the prepared samples was investigated. The processing parameters were the melt and the die temperatures. The investigated structural parameters were sand content and sand particle size. The studied tensile properties were modulus of elasticity, tensile strength, ductility and toughness. The obtained results are thoroughly analyzed and interpreted as structure-property relationships.

  11. The Shock Induced Shear Strength of Polyoxymethylene and Polyethylene

    NASA Astrophysics Data System (ADS)

    Goveas, Stephen; Millett, Jeremy; Bourne, Neil

    2007-06-01

    In the past few years, a series of papers has examined the shock response of common engineering polymers in terms of their microstructure. In this latest work, the behaviours of two polymers, polyoxymethylene and polyethylene, are investigated under conditions of one-dimensional strain. The study focuses on the experimentally determined lateral component of stress and, from knowledge of the impact conditions, the shear strength. Variations with impact stress amplitude and pulse duration are discussed in terms of the polymer chain structure.

  12. The Strength of Polyethylene and Polyoxymethylene Under Shock Loading

    NASA Astrophysics Data System (ADS)

    Goveas, S. G.; Bourne, N. K.; Millett, J. C. F.

    2007-12-01

    In the past few years, a series of papers has examined the shock response of common engineering polymers in terms of their microstructure. In this latest work, the behaviours of two polymers, polyethylene and polyoxymethylene, are investigated under conditions of one-dimensional strain. The study focuses on the experimentally determined lateral component of stress and, from knowledge of the impact conditions, the shear strength. Variations with impact stress amplitude and pulse duration are discussed in terms of the polymer chain structure.

  13. Porous polyethylene implants in facial reconstruction: Outcome and complications.

    PubMed

    Ridwan-Pramana, Angela; Wolff, Jan; Raziei, Ashkan; Ashton-James, Claire E; Forouzanfar, Tymour

    2015-10-01

    The aim of the present study was to assess the indications, results and complications of patients treated with porous polyethylene (Medpor(®)) implants in the Department of Oral and Maxillofacial Surgery of VU Medical Centre, Amsterdam over 17 years. A total of 69 high-density porous polyethylene implants (Medpor(®) Biomaterial; Porex Surgical, Newman, GA) were used in forty patients (22 males, 18 females). All patients were analysed for gender, age, diagnosis, indications for surgery, follow-up period and postoperative complications. A mean age of 34.1 years was observed. The main reason for implant surgery was post-traumatic functional impairment (27.5%). Most implants were placed at the mandibular angel and the orbital floor. Unsatisfactory appearance scored the highest in postoperative complications (10.1%) followed by infection rate (7.2%). Comparing the number of implants placed over the years and the incidence of complications, makes the overall complications rate of porous polyethylene very low. A consensus about antibiotic prophylaxis is needed. The objective measurements in patient satisfaction and proper implant design would be of great use. PMID:26276064

  14. Wear of a sequentially annealed polyethylene acetabular liner

    PubMed Central

    Gascoyne, Trevor C; Petrak, Martin J; Turgeon, Thomas R; Bohm, Eric R

    2014-01-01

    Background and purpose We previously reported on a randomized controlled trial (RCT) that examined the effect of adding tobramycin to bone cement after femoral stem migration. The present study examined femoral head penetration into both conventional and highly crosslinked polyethylene acetabular liners in the same group of RCT patients, with a minimum of 5 years of postoperative follow-up. Patients and methods Linear penetration of the femoral head into an X3 (Stryker) crosslinked polyethylene (XLPE) liner was measured in 18 patients (19 hips) using radiostereometric analysis (RSA). Femoral head penetration was also measured in 6 patients (6 hips) with a conventional polyethylene liner (CPE), which served as a control group. Results The median proximal femoral head penetration in the XLPE group after 5.5 years was 0.025 mm with a steady-state penetration rate of 0.001 mm/year between year 1 and year 5. The CPE liner showed a median proximal head penetration of 0.274 mm after 7.2 years, at a rate of 0.037 mm/year. Interpretation The Trident X3 sequentially annealed XLPE liner shows excellent in vivo wear resistance compared to non-crosslinked CPE liners at medium-term implantation. The rate of linear head penetration in the XLPE liners after > 5 years of follow-up was 0.001 mm/year, which is in close agreement with the results of previous studies. PMID:25140986

  15. Effect of cenosphere on dielectric properties of low density polyethylene

    NASA Astrophysics Data System (ADS)

    Sharma, Janu; Chand, Navin; Bapat, M. N.

    2012-01-01

    Dielectric characterization of cenosphere filled low density polyethylene composites is reported in this paper. Cenosphere filled low density polyethylene (LDPE) composites with inhomogeneous dispersions of cenosphere were prepared and dielectric measurements have been performed on these composites in the temperature range 34-110 °C in the frequency range 1-10 kHz. The dielectric constants of the composites with filler concentrations 0%, 10%, 15% and 20 vol.% were measured. Effect of temperature and frequency variations on dielectric constant (??), dissipation factor (tan ?) and a.c. conductivity (?a.c.) was also determined. The frequency dependent dielectric and conductivity behaviour of flyash cenosphere filled low density polyethylene (LDPE) polymer composites have been studied. Appearance of peak in the dielectric loss curves for all the concentrations confirms the presence of relaxing dipoles in the cenosphere/LDPE composites. The effect of filler distribution on the dielectric constant is examined and the observed differences are attributed to the differences in two kinds of interfaces present: one formed between the touching cenosphere particles and the other formed between LDPE and cenosphere. With the increase of cenosphere content dielectric constant decreased gradually. Maxwell-Garnett approximation fairly fits for the dielectric data obtained experimentally for these composites.

  16. Polyethylene macroencapsulation - mixed waste focus area. OST reference No. 30

    SciTech Connect

    1998-02-01

    The lead waste inventory throughout the US Department of Energy (DOE) complex has been estimated between 17 million and 24 million kilograms. Decontamination of at least a portion of the lead is viable but at a substantial cost. Because of various problems with decontamination and its limited applicability and the lack of a treatment and disposal method, the current practice is indefinite storage, which is costly and often unacceptable to regulators. Macroencapsulation is an approved immobilization technology used to treat radioactively contaminated lead solids and mixed waste debris. (Mixed waste is waste materials containing both radioactive and hazardous components). DOE has funded development of a polyethylene extrusion macroencapsulation process at Brookhaven National Laboratory (BNL) that produces a durable, leach-resistant waste form. This innovative macroencapsulation technology uses commercially available single-crew extruders to melt, convey, and extrude molten polyethylene into a waste container in which mixed waste lead and debris are suspended or supported. After cooling to room temperature, the polyethylene forms a low-permeability barrier between the waste and the leaching media.

  17. The use of poly(ethylene oxide) for the efficient stabilization of entrapped alpha-chymotrypsin in silicone elastomers: a chemometric study.

    PubMed

    Ragheb, Amro M; Hileman, Oliver E; Brook, Michael

    2005-12-01

    The enzyme alpha-chymotrypsin, a model for catalytic proteins, was entrapped in different silicone elastomers that were formed via the condensation-cure room temperature vulcanization (CC-RTV) of silanol terminated poly(dimethylsiloxane) with tetraethyl orthosilicate as a crosslinker, in the presence of different poly(ethylene oxide) oligomers that were functionalized with triethoxysilyl groups. The effects of various chemical factors on both the activity and entrapping efficiency of proteins (leaching) were studied using a 2-level fractional factorial design--a chemometrics approach. The factors studied include the concentration and chain length of poly(ethylene oxide), enzyme content, and crosslinker (TEOS) concentration. The study indicated that poly(ethylene oxide) can stabilize the entrapped alpha-chymotrypsin in silicone rubber: the specific activity can be maximized by incorporating a relatively high content of short chain, functional PEO. Increased enzyme concentration was found to adversely affect the specific activity. The effect of TEOS was found to be insignificant when PEO was present in the elastomer, however, it does affect the activity positively in the case of simple elastomers. PMID:15992922

  18. Poly(ethylene oxide sulfide): New Poly(ethylene glycol) Derivatives Degradable in Reductive Conditions

    E-print Network

    Park, Jong-Sang

    . On the basis of these properties, PEOS can be applied in many drug delivery fields. Among the many polymers or gene delivery,1,2 the production of lithium polymer batteries,3 cell fusion,4 protein PEGylation,5 hy- drogelation,6 and so on. Above all, PEG is an important polymer in delivery systems because it facilitates

  19. Modification and patterning of nanometer-thin poly(ethylene glycol) films by electron irradiation.

    PubMed

    Meyerbröker, Nikolaus; Zharnikov, Michael

    2013-06-12

    In this study, we analyzed the effect of electron irradiation on highly cross-linked and nanometer-thin poly(ethylene glycol) (PEG) films and, in combination with electron beam lithography (EBL), tested the possibility to prepare different patterns on their basis. Using several complementary spectroscopic techniques, we demonstrated that electron irradiation results in significant chemical modification and partial desorption of the PEG material. The initially well-defined films were progressively transformed in carbon-enriched and oxygen-depleted aliphatic layers with, presumably, still a high percentage of intermolecular cross-linking bonds. The modification of the films occurred very rapidly at low doses, slowed down at moderate doses, and exhibited a leveling off behavior at higher doses. On the basis of these results, we demonstrated the fabrication of wettability patterns and sculpturing complex 3D microstructures on the PEG basis. The swelling behavior of such morphological patterns was studied in detail, and it was shown that, in contrast to the pristine material, irradiated areas of the PEG films reveal an almost complete absence of the hydrogel-typical swelling behavior. The associated sealing of the irradiated areas allows a controlled deposition of objects dissolved in water, such as metal nanoparticles or fluorophores, into the surrounding, pristine areas, resulting in the formation of nanocomposite patterns. In contrast, due to the distinct protein-repelling properties of the PEG films, proteins are exclusively adsorbed onto the irradiated areas. This makes such films a suitable platform to prepare protein-affinity patterns in a protein-repelling background. PMID:23639274

  20. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

  1. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

  2. Conserving Waterlogged Rope: A Review of Traditional Methods and Experimental Research with Polyethylene Glycol 

    E-print Network

    McCaskill, Jennifer R.

    2010-01-16

    Conservation Research Laboratory DBTDA dibutyltin diacetate EDTA ethylenediaminetetraacetic acid INA Institute of Nautical Archaeology MTMS methyltrimethoxysilane PEG polyethylene glycol PVA polyvinyl acetate PVP polyvinyl pyrrolidone PVOH polyvinyl...

  3. Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

    DOEpatents

    Salyer, Ival O. (Dayton, OH); Griffen, Charles W. (Mason, OH)

    1986-01-01

    A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

  4. Optimization of Protein Extraction for Lichen Thalli

    PubMed Central

    Kondratiuk, Anna S.; Savchuk, Oleksiy M.

    2015-01-01

    Lichen-forming fungal proteins have been seldom searched due to many difficulties in their extraction. Phenols, quinones, proteases, and other components released during cell disruption have been known to be the greatest challenges related to protein extraction from lichens. To overcome these problems and maintain good electrophoretic resolution and high protein concentration, an extraction buffer containing polyvinylpolypyrrolidone, ascorbic acid, Triton X-100, polyethylene glycol, proteinase, and oxidase inhibitors in sodium phosphate buffer was developed. This extraction buffer showed high efficiency for all lichen species tested in the study. PMID:26190923

  5. Physiological, Ultrastructural and Proteomic Responses in the Leaf of Maize Seedlings to Polyethylene Glycol-Stimulated Severe Water Deficiency

    PubMed Central

    Shao, Ruixin; Xin, Longfei; Mao, Jun; Li, Leilei; Kang, Guozhang; Yang, Qinghua

    2015-01-01

    After maize seedlings grown in full-strength Hoagland solution for 20 days were exposed to 20% polyethylene glycol (PEG)-stimulated water deficiency for two days, plant height, shoot fresh and dry weights, and pigment contents significantly decreased, whereas malondialdehyde (MDA) content greatly increased. Using transmission electron microscopy, we observed that chloroplasts of mesophyll cells in PEG-treated maize seedlings were swollen, with a disintegrating envelope and disrupted grana thylakoid lamellae. Using two-dimensional gel electrophoresis (2-DE) method, we were able to identify 22 protein spots with significantly altered abundance in the leaves of treated seedlings in response to water deficiency, 16 of which were successfully identified. These protein species were functionally classified into signal transduction, stress defense, carbohydrate metabolism, protein metabolism, and unknown categories. The change in the abundance of the identified protein species may be closely related to the phenotypic and physiological changes due to PEG-stimulated water deficiency. Most of the identified protein species were putatively located in chloroplasts, indicating that chloroplasts may be prone to damage by PEG stimulated-water deficiency in maize seedlings. Our results help clarify the molecular mechanisms of the responses of higher plants to severe water deficiency. PMID:26370980

  6. Investigation of the fire endurance of borated polyethylene shielding material

    SciTech Connect

    Foote, K.L.

    1988-06-17

    We conducted nine experiments to investigate the fire endurance of a borated polyethylene shielding material to be used in the Engineering Demonstration System. Several chemistry tests were also done. The shielding material was found to melt at 93.5/degree/C, decompose at 230/degree/C, and ignite at 350/degree/C. Five fire tests were done in a realistic configuration and four tests in a pessimistic configuration. The material easily passed all nine tests. In each case, the shielding material never reached ignition temperature and was found acceptable in this proposed application. 7 refs., 10 figs., 3 tabs.

  7. Aspiration of barium-impregnated polyethylene spheres by a dog.

    PubMed

    Greci, V; Bissett, S A; Copple, C N; Hawkins, E C

    2010-05-01

    This case report describes an 11-year-old Belgian Malinois dog with acute onset of cough caused by aspiration of barium-impregnated polyethylene spheres (BIPS) and pneumonia following an episode of suspected gastric dilation. Although bronchoscopic retrieval of the BIPS was largely unsuccessful, the dog recovered uneventfully, with most of the BIPS being coughed out and swallowed over a 1-month period. Aspiration of BIPS should be considered a potential complication of their administration. Furthermore, endoscopic removal of aspirated BIPS is challenging and may not be indicated because of their inert nature and possible self-clearance. PMID:20529021

  8. Pyrolysis Pathways of Sulfonated Polyethylene, an Alternative Carbon Fiber Precursor

    SciTech Connect

    Younker, Jarod M; Saito, Tomonori; Hunt, Marcus A; Beste, Ariana; Naskar, Amit K

    2013-01-01

    Sulfonated polyethylene is an emerging precursor for the production of carbon fibers. Pyrolysis of sulfonated polyethylene was characterized by thermogravimetric analysis (TGA). n-heptane-4-sulfonic acid (H4S) was selected as a model compound for the study of sulfonated polyethylene. Density functional theory and conventional transition state theory were used to determine the rate constants of pyrolysis for H4S from 300-1000 K. Multiple reaction channels from two different mechanisms were explored: 1) internal five-centered elimination (Ei 5) and 2) radical chain reaction. The pyrolysis of H4S was simulated with kinetic Monte Carlo (kMC) to obtain TGA plots that compared favorably to experiment. We observed that at tem- peratures < 550 K, the radical mechanism was dominant and yielded the trans-alkene, whereas cis-alkene was formed at higher temperatures from the internal elimination. The maximum rates of % mass loss became independent of initial OH radical concentration at 440-480 K. Experimentally, the maximum % mass loss occurred from 440-460 K (heating rate dependent). Activation energies derived from the kMC-simulated TGAs of H4S (26-29 kcal/mol) agreed with experiment for sulfonated polyethylene ( 31 kcal/mol). The simulations revealed that in this region, decomposition of radical HOSO2 became competitive to H abstraction by HOSO2, making OH the carrying radical for the reaction chain. The maximum rate of % mass loss for internal elimination was observed at temperatures > 600 K. Low-scale carbonization utilizes temperatures < 620 K; thus, internal elimination will not be competitive. Ei5 elimination has been studied for sulfoxides and sulfones, but this represents the first study of internal elimination in sulfonic acids. Nonlinear Arrhenius plots were found for all bimolecular reactions. The most significant nonlinear behavior was observed for reactions where the barrier was small. For reactions with low activation barriers, nonlinearity was traced to conflicting trends between the exponential temperature dependence of the energetic term and the temperature dependence of the vibrational partition function of the transitional modes.

  9. Giant Thermal Rectification from Polyethylene Nanofiber Thermal Diodes

    E-print Network

    Zhang, Teng

    2015-01-01

    The realization of phononic computing is held hostage by the lack of high performance thermal devices. Here we show through theoretical analysis and molecular dynamics simulations that unprecedented thermal rectification factors (as large as 1.20) can be achieved utilizing the phase dependent thermal conductivity of polyethylene nanofibers. More importantly, such high thermal rectifications only need very small temperature differences (nanofiber diodes range from 12 to 25 - much larger than other thermal diodes (nanofiber thermal diode consists of a crystalline portion whose thermal conductivity is highly phase-sensitive and a cross-linked portion which has a stable phase. Nanoscale size effect can be utilized t...

  10. THz-Spectroscopy on High Density Polyethylene with Different Crystallinity

    NASA Astrophysics Data System (ADS)

    Sommer, Stefan; Raidt, Thomas; Fischer, Bernd M.; Katzenberg, Frank; Tiller, Jörg C.; Koch, Martin

    2015-11-01

    The different crystallinity states of high density polyethylene (PE-HD) are investigated using THz time-domain spectroscopy by exploiting the complex permittivity at a frequency range from 0.5 up to 3.5 THz. We found that samples with different crystallinity can be distinguished by comparing the material specific refractive index (n) or rather the linked complex part of the permittivity (? ' '). Correlating the calorimetrically determined degrees of crystallinity with the absolute values of the refractive index and the specific absorption peak at 2.18 THz, respectively, suggests in both cases a linear correlation.

  11. Catalytic degradation of high density polyethylene using zeolites.

    PubMed

    Zaggout, F R; al Mughari, A R; Garforth, A

    2001-01-01

    Plastic wastes, which cause a serious environmental problem in urban areas, can serve as sources of energy. Catalytic treatment of High Density Polyethylene (HDPE) has shown that the degradation of HDPE resulted in the production of a stream of gaseous hydrocarbons varied in the range C1-C8. The degradation was carried out using diluted forms of zeolites ZSM-5, USY and Mordenite (MORD) using a fluidized bed reactor (FBR). Effect of coke formation on the activity of the catalysts was screened by thermogravimetric (TGA). ZSM-5 showed a significant resistance to deactivation because of the nature of its small pore size compared with USY and MORD. PMID:11382018

  12. Deuterated polyethylene coatings for ultra-cold neutron applications

    NASA Astrophysics Data System (ADS)

    Brenner, Th.; Fierlinger, P.; Geltenbort, P.; Gutsmiedl, E.; Hollering, A.; Lauer, T.; Petzoldt, G.; Ruhstorfer, D.; Schroffenegger, J.; Seemann, K. M.; Soltwedel, O.; Stuiber, St.; Taubenheim, B.; Windmayer, D.; Zechlau, T.

    2015-09-01

    We report on the fabrication and use of deuterated polyethylene as a coating material for ultra-cold neutron (UCN) storage and transport. The Fermi potential has been determined to be 214 neV, and the wall loss coefficient ? is 1.3 × 104 per wall collision. The coating technique allows for a wide range of applications in this field of physics. In particular, flexible and quasi-massless UCN guides with slit-less shutters and seamless UCN storage volumes become possible. These properties enable the use in next-generation measurements of the electric dipole moment of the neutron.

  13. Analysis of the directional drilling technique for laying polyethylene pipes

    SciTech Connect

    Delorme, P.; Homand, F.

    1996-08-01

    This article reports the results of the National Microtunnels Project by the French Society Trenchless Technology. Main project components discussed include: (1) compilation of a database for worksite information; (2) drilling site descriptions, including geological conditions, techniques used, and performance obtained; and (3) in-situ measurements of tensile stresses and scratches in polyethylene pipes and drilling machinery operating parameters. An experimental approach was used to validate in-situ results through a method to calculate stresses surrounding the pipeline while being laid by directional drilling. Observations are made for each project component discussed, which are intended for use in establishing specifications for the us of directional drilling techniques. 4 refs., 7 figs.

  14. Enhancement of the predicted drug hepatotoxicity in gel entrapped hepatocytes within polysulfone-g-poly (ethylene glycol) modified hollow fiber

    SciTech Connect

    Shen Chong; Zhang Guoliang; Meng Qin

    2010-12-01

    Collagen gel-based 3D cultures of hepatocytes have been proposed for evaluation of drug hepatotoxicity because of their more reliability than traditional monolayer culture. The collagen gel entrapment of hepatocytes in hollow fibers has been proven to well reflect the drug hepatotoxicity in vivo but was limited by adsorption of hydrophobic drugs onto hollow fibers. This study aimed to investigate the impact of hollow fibers on hepatocyte performance and drug hepatotoxicity. Polysulfone-g-poly (ethylene glycol) (PSf-g-PEG) hollow fiber was fabricated and applied for the first time to suppress the drug adsorption. Then, the impact of hollow fibers was evaluated by detecting the hepatotoxicity of eight selected drugs to gel entrapped hepatocytes within PSf and PSf-g-PEG hollow fibers, or without hollow fibers. The hepatocytes in PSf-g-PEG hollow fiber showed the highest sensitivity to drug hepatotoxicity, while those in PSf hollow fiber and cylindrical gel without hollow fiber underestimated the hepatotoxicity due to either drug adsorption or low hepatic functions. Therefore, the 3D culture of gel entrapped hepatocytes within PSf-g-PEG hollow fiber would be a promising tool for investigation of drug hepatotoxicity in vitro.

  15. [The experimental assessment of high-density ultrahigh molecular weight polyethylene for the prosthetic treatment of auditory ossicles].

    PubMed

    Khorov, O G; Struk, V A; Novoseletski?, V A

    2013-01-01

    The objective of the present study was the comparative assessment of the influence of titanium and high-density ultrahigh molecular weight polyethylene (HDMPE) on the selected biochemical and immunological properties of blood and morphological features of the middle ear tissues in experimental animals. A total of 35 rabbits used were allocated to 3 groups. Groups 1 and 2 included 15 animals each. They were involved in three series of experiments (5 animals per series lasting 15, 60, and 90 days). Group 3 was comprised of 5 animals. Prosthetic treatment of auditory ossicles was performed using implants from modified high-density ultrahigh molecular weight polyethylene (group 1) and titanium implants (group 2). Control animals (group 3) remained intact. There were no significant difference between total bilirubin, AsAT, glucose, creatinine, and total protein levels in blood plasma at different time-points after surgery. HDMPE turned out to have no appreciable effect on immunological characteristics and morphological features of the soft tissues lining tympanic bulla. It is concluded that HDMPE may serve as a material for the fabrication of prostheses of the auditory ossicle chain. PMID:23528461

  16. Temperature and rate dependent finite strain behavior of poly(ethylene terephthalate) and poly(ethylene terephthalate)-glycol above the glass transition temperature

    E-print Network

    Dupaix, Rebecca B. (Rebecca Brown), 1976-

    2003-01-01

    Poly(ethylene terephthalate) is widely used for consumer products such as drawn fibers, stretched films, and soda bottles. Much of its commercial success lies in the fact that it crystallizes at large strains during warm ...

  17. 78 FR 19524 - Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan; Institution of Five-Year...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-01

    ...701-TA-415 and 731-TA-933-934 (Second Review)] Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan...determine whether revocation of the countervailing duty order on polyethylene terephthalate film, sheet, and strip (``PET...

  18. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Uses for Specific Chemical Substances § 721...epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and significant...reporting. (1) The chemical substance identified...epichlorohydrin-polyethylene glycol reaction products...

  19. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Uses for Specific Chemical Substances § 721...epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and significant...reporting. (1) The chemical substance identified...epichlorohydrin-polyethylene glycol reaction products...

  20. 78 FR 69817 - Polyethylene Retail Carrier Bags From Thailand: Final Court Decision and Amended Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-21

    ...Polyethylene Retail Carrier Bags From Thailand: Final Court Decision and Amended Final...polyethylene retail carrier bags (PRCBs) from Thailand produced or exported by King Pac Industrial...antidumping duty order on PRCBs from Thailand covering the POR, in accordance...

  1. Properties of high density polyethylene – Paulownia wood flour composites via injection molding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paulownia wood (PW) flour is evaluated as a bio-based fiber reinforcement. Composites of high density polyethylene (HDPE), 25% by weight of PW, and either 0% or 5% by weight of maleated polyethylene (MAPE) were produced by twin screw compounding followed by injection molding. Molded test composite...

  2. 78 FR 2365 - Polyethylene Terephthalate Film, Sheet and Strip From India: Partial Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... Administrative Review, 77 FR 39216, 39217 (July 2, 2012). \\2\\ Petitioners are DuPont Teijin Films, Mitsubishi..., 77 FR 52688 (August 30, 2012). \\6\\ See Polyethylene Terephthalate (PET) Film, Sheet, and Strip from... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India:...

  3. 78 FR 42105 - Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan; Notice of Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ... COMMISSION Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan; Notice of Commission... countervailing duty order on polyethylene terephthalate film, sheet, and strip (``PET'' film) from India and the antidumping duty orders on PET film from India and Taiwan would be likely to lead to continuation...

  4. 76 FR 76948 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... Administrative Review, 76 FR 47558 (August 5, 2011) (Preliminary Results), the following events have occurred... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results...) issued the preliminary results of the administrative review of polyethylene terephthalate film, sheet...

  5. 76 FR 75870 - Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Notice of Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ..., 76 FR 45227 (July 28, 2011) (Initiation Notice). \\2\\ See Polyethylene Terephthalate Film, Sheet, and Strip from Korea: Final Results of Antidumping Duty Administrative Review and Revocation in Part, 76 FR... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Notice...

  6. 77 FR 46687 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... Review, 73 FR 71601 (November 25, 2008); see also Certain Polyethylene Terephthalate Film, Sheet and...: Final Modification, 77 FR 8101 (February 14, 2012). \\52\\ See Polyethylene Terephthalate Film, Sheet, and..., Sheet, and Strip from India, 67 FR 44175 (July 1, 2002). \\2\\ See Antidumping or Countervailing...

  7. 75 FR 10758 - Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping Duty and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... Order: Polyethylene Terephthalate Film, Sheet and Strip (PET Film) from India, 67 FR 44179 (July 1, 2002... India, 67 FR 44175 (July 1, 2002) (Antidumping Duty Order). The notice announcing the countervailing... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation...

  8. 75 FR 81574 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... Countervailing Duty Order: Polyethylene Terephthalate Film, Sheet and Strip (PET Film) from India, 67 FR 44179... Countervailing Duty New Shipper Review, 75 FR 69400 (November 12, 2010); Polyethylene Terephthalate Film, Sheet..., and Strip from India, 70 FR 46483, 46485 (August 10, 2005) (PET Film Preliminary Results of...

  9. 78 FR 47276 - Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ...: Polyethylene Terephthalate Film, Sheet, and Strip From India, 67 FR 44179 (July 1, 2002). On April 2, 2012, the... 1930, as amended (the Act). See Initiation of Five-Year (``Sunset'') Reviews, 78 FR 19647 (April 2... International Trade Administration Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India:...

  10. 78 FR 48147 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary... film, sheet and strip (PET film) from India for the period of review (POR) January 1, 2011, through... polyethylene terephthalate film, sheet and strip, whether extruded or coextruded. Excluded are metallized...

  11. 78 FR 79400 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Initiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... and Amended Final Determination of Sales at Less Than Fair Value for the United Arab Emirates, 73 FR... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic... a request for a new shipper review of the antidumping duty order on polyethylene terephthalate...

  12. Association of hydrophobically-modified poly(ethylene glycol) with fusogenic liposomes

    E-print Network

    Auguste, Debra T.

    Association of hydrophobically-modified poly(ethylene glycol) with fusogenic liposomes Debra T interactions to shield liposomes by incorporating multiple hydrophobic anchoring sites on polyethylene glycol. Fusogenic liposomes prepared from N-C12-DOPE:DOPC 7:3 (mol:mol) were equilibrated with HMPEGs. Affinity

  13. Semi-Crystalline Polymers Semi-crystalline polymers, such as polyethylene and polypropylene are common

    E-print Network

    Beaucage, Gregory

    Semi-Crystalline Polymers Semi-crystalline polymers, such as polyethylene and polypropylene are common commercial materials used for consumer products. Polyethylene is the most widely used polymer due a future competitor for polyolefins. Due to the length of a polymer molecule, the variability in length

  14. Influence of Molecular Structure on the Rheology and Thermorheology of Metallocene Polyethylenes

    E-print Network

    Hussein, Ibnelwaleed A.

    Influence of Molecular Structure on the Rheology and Thermorheology of Metallocene Polyethylenes. The linear metallocenes were prepared by gas-phase polymerization, while the branched PEs were commercial energy; metallocene polyethylene INTRODUCTION Molecular architecture is known to have a strong in

  15. Adhesion energy in carbon nanotube-polyethylene composite: Effect of chirality

    E-print Network

    Garmestani, Hamid

    Adhesion energy in carbon nanotube-polyethylene composite: Effect of chirality M. Al-Haik and M. Y 2005 This work presents a study of the adhesion energy between carbon nanotube-polyethylene matrix nanotube chirality on adhesion energy. It is observed that composites that utilize nanotubes with smaller

  16. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  17. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  18. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  19. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  20. Mechanical and thermal properties of high density polyethylene – dried distillers grains with solubles composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried Distillers Grain with Solubles (DDGS) is evaluated as a bio-based fiber reinforcement. Injection molded composites of high density polyethylene (HDPE), 25% by weight of DDGS, and either 5% of 0% by weight of maleated polyethylene (MAPE) were produced by twin screw compounding and injection mo...

  1. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  2. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  3. Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water

    E-print Network

    Short, Daniel

    higher doses caused increased occurrences of lung, liver and bile cancers (Schnorr et al., 1995, JonesLeaching of antimony from polyethylene terephthalate (PET) bottles into mineral water Szilvia SODIS The Sb leaching from polyethylene terephthalate (PET) package material into 10 different brands

  4. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food in... ethylene oxide and water with a mean molecular weight of 200 to 9,500. (2) It contains no more than...

  5. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9... molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as a... conditions: (a) The additive is an addition polymer of ethylene oxide and water with a mean molecular...

  6. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as a... conditions: (a) The additive is an addition polymer of ethylene oxide and water with a mean molecular...

  7. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9... weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food in... ethylene oxide and water with a mean molecular weight of 200 to 9,500. (2) It contains no more than...

  8. 78 FR 50376 - Polyethylene Retail Carrier Bags From Thailand: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... Antidumping Duty Administrative Review; 2011- 2012, 78 FR 28192 (May 14, 2013) (Preliminary Results). The... at Less Than Fair Value: Polyethylene Retail Carrier Bags From Thailand, 69 FR 34122- 34124 (June 18... Review, 72 FR 1982, 1983 (January 17, 2007), Polyethylene Retail Carrier Bags from Thailand:...

  9. A COMPARATIVE STUDY OF THE WETTABILITY OF STEEL, CARBON, AND POLYETHYLENE FIBERS BY WATER

    E-print Network

    Chung, Deborah D.L.

    A COMPARATIVE STUDY OF THE WETTABILITY OF STEEL, CARBON, AND POLYETHYLENE FIBERS BY WATER W. Lu, X at Buffalo, Buffalo, NY 14260-4400, USA (Received March 9, 1998; in final form April 10, 1998) ABSTRACT The wettability of fibers by water was found to increase in this order: polyethylene fiber, steel fiber

  10. Acute Repair of Crushed Guinea Pig Spinal Cord by Polyethylene Glycol

    E-print Network

    Shi, Riyi

    Acute Repair of Crushed Guinea Pig Spinal Cord by Polyethylene Glycol RIYI SHI AND RICHARD B of crushed guinea pig spinal cord by polyethylene glycol. J. Neurophysiol. 81: 2406­2414, 1999. We have studied the responses of adult guinea pig spinal cord white matter to a standardized compression within

  11. Effect of thermal modification on rheological properties of polyethylene blends

    SciTech Connect

    Siriprumpoonthum, Monchai; Nobukawa, Shogo; Yamaguchi, Masayuki; Satoh, Yasuo; Sasaki, Hiroko

    2014-03-15

    We examined the effects of thermal modification under flow field on the rheological properties of linear low-density polyethylene (LLDPE) with high molecular weight, low-density polyethylene (LDPE), and their blends, without thermal stabilizer. Although structural changes during processing are not detected by size extrusion chromatography or nuclear magnetic resonance spectroscopy, linear viscoelastic properties changed greatly, especially for the LLDPE. A cross-linking reaction took place, leading to, presumably, star-shaped long-chain branches. Consequently, the modified LLDPE, having high zero-shear viscosity, became a thermorheologically complex melt. Moreover, it should be noted that the drawdown force, defined as the uniaxial elongational force at a constant draw ratio, was significantly enhanced for the blends. Enhancement of elongational viscosity was also detected. The drawdown force and elongational viscosity are marked for the thermally modified blend as compared with those for the blend of thermally modified pure components. Intermolecular cross-linking reactions between LDPE and LLDPE, yielding polymers with more than two branch points per chain, result in marked strain-hardening in the elongational viscosity behavior even at small strain. The recovery curve of the oscillatory modulus after the shear modification is further evidence of a branched structure.

  12. Wear characteristics of ultrahigh molecular weight polyethylene (UHMWPE)

    NASA Astrophysics Data System (ADS)

    El-Domiaty, A.; El-Fadaly, M.; Nassef, A. Es.

    2002-10-01

    The wear of ultrahigh molecular weight polyethylene (UHMWPE) bearing against 316 stainless steel or cobalt chromium (Co-Cr) alloy was measured using a 12-channel wear tester especially developed for the evaluation of candidate materials for prosthetic joints. The coefficient of friction and wear rate were determined as a function of lubricant, contact stress, and metallic surface roughness in tests lasting 2 3 million cycles, the equivalent of several years use of a prosthesis. Wear was determined by the weight loss of the polyethylene (PE) specimens corrected for the effect of fluid absorption. The friction and wear processes in blood serum differed markedly from those in saline solution or distilled water. Only serum lubrication produced wear surfaces resembling those observed on removed prostheses. The experimental methods provided accurate reproducible measurement of PE wear. The long-term wear rates were proportional to load and sliding distance. Although the PE wear rate increased with increasing surface roughness, wear was not severe except with very coarse metal surfaces. The data obtained in these studies formed a comparison basis for the subsequent evaluation of potentially superior materials for prosthetic joints.

  13. Analyzing and improving viscoelastic properties of high density polyethylene

    NASA Astrophysics Data System (ADS)

    Ahmed, Reaj Uddin

    2011-12-01

    High Density Polyethylene (HDPE) is closely packed, less branched polyethylene having higher mechanical properties, chemical resistance, and heat resistance than Low Density Polyentylene (LDPE). Better properties and cost effectiveness make it an important raw material over LDPE in packaging industries. Stacked containers made of HDPE experience static loading and deformation strain during their storage period in a warehouse. As HDPE is a viscoelastic material, dimensional stability of stacked HDPE containers depends on time dependent properties such as creep and stress relaxation. Now, light weighting is a driving force in packaging industries, which results in lower production costs but performance of the product becomes a challenge. Proper understanding of the viscoelastic properties of HDPE, with relevant FE simulation can facilitate improved designs. This research involves understanding and improving viscoelastic properties, creep behavior, and stress relaxation of HDPE. Different approaches were carried out to meet the objectives. Organic filler CaCO3 was added to HDPE at increasing weight fractions and corresponding property changes were investigated. Annealing heat treatments were also carried out for potential property improvements. The effect of ageing was also investigated on both annealed and non annealed HDPE. The related performance of different water bottles against squeeze pressure was also characterized. Both approaches, incorporation of CaCO3 and annealing, showed improvements in the properties of HDPE over neat HDPE. This research aids finding the optimum solution for improving viscoelastic properties, stress relaxation, and creep behavior of HDPE in manufacturing.

  14. FhuA deletion variant ?1-159 overexpression in inclusion bodies and refolding with Polyethylene-Poly(ethylene glycol) diblock copolymer.

    PubMed

    Dworeck, Tamara; Petri, Anne-Kathrin; Muhammad, Noor; Fioroni, Marco; Schwaneberg, Ulrich

    2011-05-01

    Membrane protein isolation is a challenging problem. In fact especially their extraction from the respective membrane is difficult and often goes along with losses in yield. Usually expensive detergents are needed to extract the target protein from the membrane. Therefore finding an efficient overexpression and extraction method and an alternative to detergents is desirable. In this study we describe a new and fast method to express, extract and purify an engineered variant of the FhuA protein (FhuA ?1-159) that acts as passive diffusion channel, using a diblock copolymer as an alternative to detergents like octyl-POE (n-octylpolyoxyethylene). The N-terminal leader sequence, facilitating the protein's transport to the outer membrane was deleted (FhuA ?1-159 ?signal), resulting in protein accumulation in easy to isolate inclusion bodies. Urea was used to solubilise the unfolded protein and dialysis against phosphate-buffer containing the commercially available diblock copolymer PE-PEG[Polyethylene-Poly(ethyleneglycol)] lead to protein refolding. Circular dichroism spectroscopy revealed a high ?-sheet percentage within the refolded protein secondary structure indicating the successful reconstitution of FhuA ?1-159 ?signal native state. Furthermore the channel functionality of FhuA ?1-159 ?signal was verified by measuring the in and out-flux through the protein when inserted into liposome membrane, using the HRP/TMB (HRP=Horse Radish Peroxidase, TMB=3,3',5,5'-tetramethylbenzidine) assay system. PMID:21168506

  15. Size-exclusion separation of proteins using a biocompatible polymeric monolithic capillary column with mesoporosity.

    PubMed

    Li, Yun; Tolley, H Dennis; Lee, Milton L

    2010-12-24

    Biocompatible poly(ethylene glycol methyl ether acrylate-co-polyethylene glycol diacrylate) monoliths were prepared for size exclusion chromatography (SEC) of proteins in the capillary format using Brij 58P in a mixture of hexanes and dodecanol as porogens. The monolithic columns provided size separation of four proteins in 20 mM sodium phosphate buffer (pH 7.0) containing 0.15 M NaCl, and there was a linear relationship between the retention times and the logarithmic values of the molecular weights. Compared to SEC monoliths previously synthesized using a triblock copolymer of polyethylene oxide and polypropylene oxide, an increase in mesoporosity was confirmed by inverse size exclusion chromatography. As a result, improved protein separation in the high molecular weight range and reduced column back-pressure were observed. PMID:21084091

  16. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with epichlorohydrin-polyethylene glycol reaction products. 721.10472 Section 721.10472 Protection of...-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and..., polymers with epichlorohydrin-polyethylene glycol reaction products (PMN P-03-645; CAS No. 652968-34-8)...

  17. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with epichlorohydrin-polyethylene glycol reaction products. 721.10472 Section 721.10472 Protection of...-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and..., polymers with epichlorohydrin-polyethylene glycol reaction products (PMN P-03-645; CAS No. 652968-34-8)...

  18. Solution and film properties of sodium caseinate/glycerol and sodium caseinate/polyethylene glycol edible coating systems.

    PubMed

    Siew, D C; Heilmann, C; Easteal, A J; Cooney, R P

    1999-08-01

    The aim of this study is to determine the effects of plasticizer hydrogen bonding capability and chain length on the molecular structure of sodium caseinate (NaCAS), in NaCAS/glycerol and NaCAS/polyethylene glycol 400 (PEG) systems. Both solution and film phases were investigated. Glycerol and PEG reduced the viscosity of aqueous NaCAS, with the latter having a greater effect. This was explained in terms of protein/plasticizer aggregate size and changes to the conformation of the caseinate chain. In the film phase, glycerol caused more pronounced changes to the film tensile strength compared with PEG. However, the effect of glycerol on film water vapor permeability was smaller. These observations are attributed to the differences in plasticizer size and hydrogen bonding strength that controls the protein-plasticizer and protein-protein interactions in the films. Glass transition calculations from the tensile strength data indicate that the distribution of bonding interactions is more homogeneous in NaCAS/PEG films than in NaCAS/glycerol films. PMID:10552668

  19. Comparison between polyethylene glycol and zwitterionic polymers as antifouling coatings on wearable devices for selective antigen capture from biological tissue.

    PubMed

    Robinson, Kye J; Coffey, Jacob W; Muller, David A; Young, Paul R; Kendall, Mark A F; Thurecht, Kristofer J; Grøndahl, Lisbeth; Corrie, Simon R

    2015-01-01

    Selective capture of disease-related proteins in complex biological fluids and tissues is an important aim in developing sensitive protein biosensors for in vivo applications. Microprojection arrays are biomedical devices whose mechanical and chemical properties can be tuned to allow efficient penetration of skin, coupled with highly selective biomarker capture from the complex biological environment of skin tissue. Herein, the authors describe an improved surface modification strategy to produce amine-modified polycarbonate arrays, followed by the attachment of an antifouling poly(sulfobetaine-methacrylate) (pSBMA) polymer or a linear polyethylene glycol (PEG) polymer of comparative molecular weight and hydrodynamic radius. Using a "grafting to" approach, pSBMA and linear PEG coatings yielded comparative antifouling behavior in single protein solutions, diluted plasma, or when applied to mouse flank skin penetrating into the vascularized dermal tissue. Interestingly, the density of immobilized immunoglobulin G (IgG) or bovine serum albumin protein on pSBMA surfaces was significantly higher than that on the PEG surfaces, while the nonspecific adsorption was comparable for each protein. When incubated in buffer or plasma solutions containing dengue non-structural protein 1 (NS1), anti-NS1-IgG-coated pSBMA surfaces captured significantly more NS1 in comparison to PEG-coated devices. Similarly, when wearable microprojection arrays were applied to the skin of dengue-infected mice using the same coatings, the pSBMA-coated devices showed significantly higher capture efficiency (>2-fold increase in signal) than the PEG-coated substrates, which showed comparative signal when applied to naïve mice. In conclusion, zwitterionic pSBMA polymers (of equivalent hydrodynamic radii to PEG) allowed detection of dengue NS1 disease biomarker in a preclinical model of dengue infection, showing significantly higher signal-to-noise ratio in comparison to the PEG controls. The results of this study will be useful in the future development of a range of protein biosensors designed for use in vivo. PMID:26446192

  20. Poly(ethylene glycol)-containing hydrogel surfaces for antifouling applications in marine and freshwater environments.

    PubMed

    Ekblad, Tobias; Bergström, Gunnar; Ederth, Thomas; Conlan, Sheelagh L; Mutton, Robert; Clare, Anthony S; Wang, Su; Liu, Yunli; Zhao, Qi; D'Souza, Fraddry; Donnelly, Glen T; Willemsen, Peter R; Pettitt, Michala E; Callow, Maureen E; Callow, James A; Liedberg, Bo

    2008-10-01

    This work describes the fabrication, characterization, and biological evaluation of a thin protein-resistant poly(ethylene glycol) (PEG)-based hydrogel coating for antifouling applications. The coating was fabricated by free-radical polymerization on silanized glass and silicon and on polystyrene-covered silicon and gold. The physicochemical properties of the coating were characterized by infrared spectroscopy, ellipsometry, and contact angle measurements. In particular, the chemical stability of the coating in artificial seawater was evaluated over a six-month period. These measurements indicated that the degradation process was slow under the test conditions chosen, with the coating thickness and composition changing only marginally over the period. The settlement behavior of a broad and diverse group of marine and freshwater fouling organisms was evaluated. The tested organisms were barnacle larvae (Balanus amphitrite), algal zoospores (Ulva linza), diatoms (Navicula perminuta), and three bacteria species (Cobetia marina, Marinobacter hydrocarbonoclasticus, and Pseudomonas fluorescens). The biological results showed that the hydrogel coating exhibited excellent antifouling properties with respect to settlement and removal. PMID:18759475

  1. Polyethylene glycol reduces inflammation and aberrant crypt foci in carcinogen-initiated rats.

    PubMed

    Karlsson, Pernilla C; Hughes, Roisin; Rafter, Joseph J; Bruce, W Robert

    2005-06-01

    Polyethylene glycol 8000 inhibits the formation of tumors and of aberrant crypt foci (ACF) in carcinogen-initiated rats. We asked: is the inhibition associated with a reduction of colonic inflammation and an increase in colonic cell permeability? Twenty-eight, male F 344 rats were divided into two groups, 10 control animals and 18 animals initiated with azoxymethane. Nine of the rats in the carcinogen-initiated group were given a diet with 5% PEG 8000 in an AIN-93 based, high fat diet. The other nine, and the control group received the diet without the addition of PEG. Nine weeks later, the rats receiving the diet containing PEG had a 43% reduction in ACF (P<0.001) compared with the carcinogen-initiated rats on the control diet, a result confirming earlier observations that PEG inhibits colon carcinogenesis. The animals receiving the diet containing PEG also had a 10-fold reduction in fecal granulocyte marker protein (GMP) (P<0.001) compared with both the carcinogen-treated and the control animals. PEG reduced inflammation below the levels of carcinogen-treated and of untreated animals. Fecal water from the rats receiving PEG did not reduce transepithelial resistance of, or manitol flux through, human Caco-cells grown as monolayers in vitro. PEG may reduce colon carcinogenesis through a mechanism involving colonic inflammation. PMID:15896454

  2. Relevance of the poly(ethylene glycol) linkers in peptide surfaces for proteases assays.

    PubMed

    Trzcinska, Roza; Balin, Katarzyna; Kubacki, Jerzy; Marzec, Magdalena E; Pedrys, Roman; Szade, Jacek; Silberring, Jerzy; Dworak, Andrzej; Trzebicka, Barbara

    2014-05-01

    Poly(ethylene glycol)s (PEGs) with different lengths were used as linkers during the preparation of peptide surfaces for protease detection. In the first approach, the PEG monolayers were prepared using a "grafting to" method on 3-aminopropyltrietoxysilane (APTES)-modified silicon wafers. Protected peptides with a fluorescent marker were synthesized by Fmoc solid phase synthesis. The protected peptide structures enabled their site-specific immobilization onto the PEG surfaces. Alternatively, the PEG-peptide surface was obtained by immobilizing a PEG-peptide conjugate directly onto the modified silicon wafer. The surfaces (composition, grafting density, hydrophilicity, and roughness) were characterized by time-of-flight-secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), contact angle (CA), and atomic force microscopy (AFM). Introducing the PEG linker between the peptide and surface increased their resistance toward nonspecific protein adsorption. The peptide surfaces were examined as analytical platforms to study the action of trypsin as a representative protease. The products of the enzymatic hydrolysis were analyzed by fluorescence spectroscopy, electrospray ionization-mass spectrometry (ESI-MS), and ToF-SIMS. Conclusions about the optimal length of the PEG linker for the analytical application of PEG-peptide surfaces were drawn. This work demonstrates an effective synthetic procedure to obtain PEG-peptide surfaces as attractive platforms for the development of peptide microarrays. PMID:24697681

  3. Characteristics of Cultured Tomato Cells after Prolonged Exposure to Medium Containing Polyethylene Glycol 1

    PubMed Central

    Handa, Avtar K.; Bressan, Ray A.; Handa, Sangita; Hasegawa, Paul M.

    1982-01-01

    Cell lines of tomato (Lycopersicon esculentum Mill., cv. VFNT-Cherry) have been isolated, which are capable of growing in media containing polyethylene glycol (PEG) 6000 with water potentials as low as ?15 or ?22 bar. After prolonged exposure to media containing PEG, these cell populations have reduced abilities to grow in the absence of PEG. Upon resuspension in PEG-free medium, the cells swell and begin to release metabolites, including protein. Measurement by plasmometry of the osmotic potential of cells selected in medium with ?22 bar water potential indicates that they maintain, at the end of the growth cycle, an osmotic potential of approximately ?26 bar. This is compared to an osmotic potential of ?9 bar for nonselected cells in medium without PEG, having an initial water potential of ?4 bar. Thus, considerable osmotic adjustment occurs as a result of exposure to external low water potential. The results also indicate that PEG does not contribute significantly to osmotic adjustment of the cells. Images PMID:16662239

  4. Injectable Dopamine-Modified Poly(ethylene glycol) Nanocomposite Hydrogel with Enhanced Adhesive Property and Bioactivity

    PubMed Central

    2015-01-01

    A synthetic mimic of mussel adhesive protein, dopamine-modified four-armed poly(ethylene glycol) (PEG-D4), was combined with a synthetic nanosilicate, Laponite (Na0.7+(Mg5.5Li0.3Si8)O20(OH)4)0.7–), to form an injectable naoncomposite tissue adhesive hydrogel. Incorporation of up to 2 wt % Laponite significantly reduced the cure time while enhancing the bulk mechanical and adhesive properties of the adhesive due to strong interfacial binding between dopamine and Laponite. The addition of Laponite did not alter the degradation rate and cytocompatibility of PEG-D4 adhesive. On the basis of subcutaneous implantation in rat, PEG-D4 nanocomposite hydrogels elicited minimal inflammatory response and exhibited an enhanced level of cellular infiltration as compared to Laponite-free samples. The addition of Laponite is potentially a simple and effective method for promoting bioactivity in a bioinert, synthetic PEG-based adhesive while simultaneously enhancing its mechanical and adhesive properties. PMID:25222290

  5. Polyethylene glycol acrylate-grafted polysulphone membrane for artificial lungs: plasma modification and haemocompatibility improvement.

    PubMed

    Wang, Weiping; Huang, Xin; Yin, Haiyan; Fan, Wenling; Zhang, Tao; Li, Lei; Mao, Chun

    2015-01-01

    In this study, polyethylene glycol acrylate (PEGA) was introduced onto the surface of polysulphone (PSF) membrane to prepare PSF-PEGA membranes through low-temperature plasma technology for haemocompatibility improvement of artificial lungs. The effects of plasma power, PEGA solution concentration and dipcoating temperature on surface modification were systematically investigated. Results of Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and PEGA grafting degree confirmed that PEGA was successfully grafted onto the PSF membranes. Contact angle values showed that the hydrophilicity of the PSF-PEGA membrane surface increased by 21.5%. The results of the protein adsorption, platelet adhesion and coagulation tests further showed the excellent haemocompatibility of the modified membrane. Gas exchange tests also revealed that at a porcine blood flow rate of 5 l min(-1), O2 and CO2 exchange rates through the PSF-PEGA membrane were 198.6 and 170.9?ml min(-1), respectively; approximately this is the gas exchange capacity of commercial respiratory assistance devices. PMID:26658212

  6. Subunit Stabilization and Polyethylene Glycolation of Cocaine Esterase Improves In Vivo Residence Time

    SciTech Connect

    Narasimhan, Diwahar; Collins, Gregory T.; Nance, Mark R.; Nichols, Joseph; Edwald, Elin; Chan, Jimmy; Ko, Mei-Chuan; Woods, James H.; Tesmer, John J.G.; Sunahara, Roger K.

    2012-03-15

    No small-molecule therapeutic is available to treat cocaine addiction, but enzyme-based therapy to accelerate cocaine hydrolysis in serum has gained momentum. Bacterial cocaine esterase (CocE) is the fastest known native enzyme that hydrolyzes cocaine. However, its lability at 37 C has limited its therapeutic potential. Cross-linking subunits through disulfide bridging is commonly used to stabilize multimeric enzymes. Herein we use structural methods to guide the introduction of two cysteine residues within dimer interface of CocE to facilitate intermolecular disulfide bond formation. The disulfide-crosslinked enzyme displays improved thermostability, particularly when combined with previously described mutations that enhance stability (T172R-G173Q). The newly modified enzyme yielded an extremely stable form of CocE (CCRQ-CocE) that retained greater than 90% of its activity after 41 days at 37 C, representing an improvement of more than 4700-fold over the wild-type enzyme. CCRQ-CocE could also be modified by polyethylene glycol (PEG) polymers, which improved its in vivo residence time from 24 to 72 h, as measured by a cocaine lethality assay, by self-administration in rodents, and by measurement of inhibition of cocaine-induced cardiovascular effects in rhesus monkeys. PEG-CCRQ elicited negligible immune response in rodents. Subunit stabilization and PEGylation has thus produced a potential protein therapeutic with markedly higher stability both in vitro and in vivo.

  7. Intraluminal polyethylene glycol stabilizes tight junctions and improves intestinal preservation in the rat.

    PubMed

    Oltean, M; Joshi, M; Björkman, E; Oltean, S; Casselbrant, A; Herlenius, G; Olausson, M

    2012-08-01

    Rapidly progressing mucosal breakdown limits the intestinal preservation time below 10 h. Recent studies indicate that intraluminal solutions containing polyethylene glycol (PEG) alleviate preservation injury of intestines stored in UW-Viaspan. We investigated whether a low-sodium PEG solution is beneficial for intestines stored in histidine-tryptophane-ketoglutarate (HTK) preservation solution. Rat intestines used as control tissue (group 1) were perfused with HTK, groups 2 and 3 received either a customized PEG-3350 (group 2) or an electrolyte solution (group 3) intraluminally before cold storage. Tissue injury, brush-border maltase activity, zonula occludens-1 (ZO-1) and claudin-3 expression in the tight junctions (TJ) were analyzed after 8, 14 and 20 h. We measured epithelial resistance and permeability (Ussing chamber) after 8 and 14 h. Group 2 had superior morphology while maltase activity was similar in all groups. TJ proteins rapidly decreased and decolocalized in groups 1 3; these negative events were delayed in group 2, where colocalization persisted for about 14 h. Intestines in group 2 had higher epithelial resistance and lower permeability than the other groups. These results suggest that a customized PEG solution intraluminally reduces the intestinal preservation injury by improving several major epithelial characteristics without negatively affecting the brush-border enzymes or promoting edema. PMID:22548829

  8. Prevention of peritendinous adhesions with electrospun polyethylene glycol/polycaprolactone nanofibrous membranes.

    PubMed

    Chen, Chih-Hao; Chen, Shih-Hsien; Shalumon, K T; Chen, Jyh-Ping

    2015-09-01

    Postoperative adhesion formation is the major complication that could occur after acute tendon surgery. The application of an anti-adhesive membrane at the post-surgical site is deemed as a potential way to solve this problem by preventing adhesive fibrotic tissue development. In this study, we fabricated electrospun composite poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) nanofibrous membrane (NFM) to prevent peritendinous adhesions, which could act as a barrier between the tendon and surrounding tissues, without interrupting mass transfer and normal tendon gliding. PCL/PEG NFMs of 0% PEG (PCL), 25% PEG (25PECL), 50% PEG (50PECL) and 75% PEG (75PECL) were prepared and characterized for physico-chemical properties. The PCL NFM shows the lowest protein permeability while 25PECL NFM exhibited the largest fiber diameter, smallest pore size and the largest ultimate stress and strain. The 75PECL NFM had the lowest water contact angle and the highest Young's modulus. In vitro cell adhesion and migration experiments with fibroblasts indicate that all NFMs could prevent cell penetration, with 75PECL NFM having the least cell attachment. In vivo application of 75PECL NFM on the repaired site of rabbit flexor tendon rupture model demonstrated improved efficacy compared with the PCL NFM and a commercial anti-adhesion barrier (Seprafilm™), from gross observation, histological analysis and functional assays. We concluded that 75PECL NFM could function as an effective anti-adhesion membrane after tendon surgery in a clinical setting. PMID:26115533

  9. Biodegradable DNA-enabled poly(ethylene glycol) hydrogels prepared by copper-free click chemistry.

    PubMed

    Barker, Karolyn; Rastogi, Shiva K; Dominguez, Jose; Cantu, Travis; Brittain, William; Irvin, Jennifer; Betancourt, Tania

    2016-01-01

    Significant research has focused on investigating the potential of hydrogels in various applications and, in particular, in medicine. Specifically, hydrogels that are biodegradable lend promise to many therapeutic and biosensing applications. Endonucleases are critical for mechanisms of DNA repair. However, they are also known to be overexpressed in cancer and to be present in wounds with bacterial contamination. In this work, we set out to demonstrate the preparation of DNA-enabled hydrogels that could be degraded by nucleases. Specifically, hydrogels were prepared through the reaction of dibenzocyclooctyne-functionalized multi-arm poly(ethylene glycol) with azide-functionalized single-stranded DNA in aqueous solutions via copper-free click chemistry. Through the use of this method, biodegradable hydrogels were formed at room temperature in buffered saline solutions that mimic physiological conditions, avoiding possible harmful effects associated with other polymerization techniques that can be detrimental to cells or other bioactive molecules. The degradation of these DNA-cross-linked hydrogels upon exposure to the model endonucleases Benzonase(®) and DNase I was studied. In addition, the ability of the hydrogels to act as depots for encapsulation and nuclease-controlled release of a model protein was demonstrated. This model has the potential to be tailored and expanded upon for use in a variety of applications where mild hydrogel preparation techniques and controlled material degradation are necessary including in drug delivery and wound healing systems. PMID:26541212

  10. Anisotropic Poly(Ethylene Glycol)/Polycaprolactone Hydrogel–Fiber Composites for Heart Valve Tissue Engineering

    PubMed Central

    Tseng, Hubert; Puperi, Daniel S.; Kim, Eric J.; Ayoub, Salma; Shah, Jay V.; Cuchiara, Maude L.; West, Jennifer L.

    2014-01-01

    The recapitulation of the material properties and structure of the native aortic valve leaflet, specifically its anisotropy and laminate structure, is a major design goal for scaffolds for heart valve tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are attractive scaffolds for this purpose as they are biocompatible, can be modified for their mechanical and biofunctional properties, and can be laminated. This study investigated augmenting PEG hydrogels with polycaprolactone (PCL) as an analog to the fibrosa to improve strength and introduce anisotropic mechanical behavior. However, due to its hydrophobicity, PCL must be modified prior to embedding within PEG hydrogels. In this study, PCL was electrospun (ePCL) and modified in three different ways, by protein adsorption (pPCL), alkali digestion (hPCL), and acrylation (aPCL). Modified PCL of all types maintained the anisotropic elastic moduli and yield strain of unmodified anisotropic ePCL. Composites of PEG and PCL (PPCs) maintained anisotropic elastic moduli, but aPCL and pPCL had isotropic yield strains. Overall, PPCs of all modifications had elastic moduli of 3.79±0.90?MPa and 0.46±0.21?MPa in the parallel and perpendicular directions, respectively. Valvular interstitial cells seeded atop anisotropic aPCL displayed an actin distribution aligned in the direction of the underlying fibers. The resulting scaffold combines the biocompatibility and tunable fabrication of PEG with the strength and anisotropy of ePCL to form a foundation for future engineered valve scaffolds. PMID:24712446

  11. Protective Effect of Intravenous High Molecular Weight Polyethylene Glycol on Fatty Liver Preservation

    PubMed Central

    Bejaoui, Mohamed; Pantazi, Eirini; Folch-Puy, Emma; Panisello, Arnau; Calvo, María; Pasut, Gianfranco; Rimola, Antoni; Navasa, Miquel; Adam, René; Roselló-Catafau, Joan

    2015-01-01

    Ischemia reperfusion injury (IRI) leads to significant tissue damage in liver surgery. Polyethylene glycols (PEGs) are water soluble nontoxic polymers that have proved their effectiveness against IRI. The objective of our study was to investigate the potential protective effects of intravenous administration of a high molecular weight PEG of 35?kDa (PEG 35) in steatotic livers subjected to cold ischemia reperfusion. In this study, we used isolated perfused rat liver model to assess the effects of PEG 35 intravenous administration after prolonged cold ischemia (24?h, 4°C) and after reperfusion (2?h, 37°C). Liver injury was measured by transaminases levels and mitochondrial damage was determined by confocal microscopy assessing mitochondrial polarization (after cold storage) and by measuring glutamate dehydrogenase activity (after reperfusion). Also, cell signaling pathways involved in the physiopathology of IRI were assessed by western blot technique. Our results show that intravenous administration of PEG 35 at 10?mg/kg ameliorated liver injury and protected the mitochondria. Moreover, PEG 35 administration induced a significant phosphorylation of prosurvival protein kinase B (Akt) and activation of cytoprotective factors e-NOS and AMPK. In conclusion, intravenous PEG 35 efficiently protects steatotic livers exposed to cold IRI. PMID:26543868

  12. Multifunctional copolymer coating of polyethylene glycol, glycidyl methacrylate, and REDV to enhance the selectivity of endothelial cells.

    PubMed

    Wei, Yu; Zhang, Jingxun; Li, Haolie; Zhang, Li; Bi, Hong

    2015-12-01

    Multifunctional polymer coatings have potential applications in biomaterials. These coatings possess reactive functional groups for the immobilization of specific biological factors that can influence cellular behavior. These coatings also display low nonspecific protein adsorption. In this study, we prepared a multifunctional polymer coating through the deposition of random copolymers of poly(ethylene glycol) methacrylate (PEGMA) and glycidyl methacrylate (GMA) to prevent nonspecific attachment and enable the covalence of Arg-Glu-Asp-Val (REDV) peptide with endothelial cells (ECs) selectivity. Coatings were characterized by X-ray photoelectron spectroscopy (XPS). The adhesion and proliferation of ECs and smooth muscle cells (SMCs) onto the REDV-modified surface were investigated to understand the synergistic action of antifouling PEG and EC selective REDV peptide conjugated GMA. The copolymers containing GMA and PEG groups are very useful as a multifunctional coating material with anti-fouling and ECs specific adhesion for implant materials surface modification. PMID:26381476

  13. Elaboration et caracterisation de nanocomposites polyethylene/montmorillonite

    NASA Astrophysics Data System (ADS)

    Stoeffler, Karen

    This research project consists in preparing polyethylene/montmorillonite nanocomposites for film packaging applications. Montmorillonite is a natural clay with an exceptional aspect ratio. In recent years, its incorporation in polymer matrices has attracted great interest. The pioneer work from Toyota on polyamide-6/montmorillonite composites has shown that it was possible to disperse the clay at a nanometric scale. Such a structure, so-called exfoliated, leads to a significant increase in mechanical, barrier and fire retardant properties, even at low volumetric fractions of clay. This allows a valorization of the polymeric material at moderate cost. Due to its high polarity, montmorilloite exfoliation in polymeric matrices is problematic. In the particular case of polyolefin matrices, the platelets dispersion remains limited: most frequently, the composites obtained exhibit conventional structures (microcomposites) or intercalated structures. To solve this problem, two techniques are commonly employed: the surface treatment of the clay, which allows the expansion of the interfoliar gallery while increasing the affinity between the clay and the polymer, and the use of a polar compatibilizing agent (grafted polyolefin). The first part of this thesis deals with the preparation and the characterization of highly thermally stable organophilic montmorillonites. Commercial organophilic montmorillonites are treated with quaternary ammonium intercalating agents. However, those intercalating agents present a poor thermal stability and are susceptible to decompose upon processing, thus affecting the clay dispersion and the final properties of the nanocomposites. In this work, it was proposed to modify the clay with alkyl pyridinium, alkyl imidazolium and alkyl phosphonium intercalating agents, which are more stable than ammonium based cations. Organophilic montmorillonites with enhanced thermal stabilites compared to commercial organoclays (+20°C to +70°C) were prepared. The effect of the chemical structure of the intercalating agent on the capacity of the organoclay to be dispersed in polyethylene matrices was analyzed. In addition, the influence of the dispersion on the thermal stability of the nanocomposites prepared is discussed. In a second part, the effect of the compatibilizing agent characteristics on the quality of the clay dispersion in polyethylene/montmorillonite nanocomposites was analyzed. The mechanical properties and the oxygen permeability of the nanocomposites were evaluated and related to the level of clay delamination and to the strength of the polymer/clay interface, which was evaluated through surface tension measurements.

  14. Protein-to-film adhesion as examined by amino analysis of protein binding to three different packaging films.

    PubMed

    Clardy, C B; Han, I Y; Acton, J C; Wardlaw, F B; Bridges, W B; Dawson, P L

    1998-05-01

    A weak protein solution extracted from chicken breast meat was exposed to three types of packaging materials. The crude myofibrillar protein solution (12.0 mg protein/mL buffer) was suspended in a 0.6M NaCl/NaPO4 buffer, then placed in bags made from either polyethylene (nonbinding film), a nylon blend (binding film), or Surlyn (binding film). Two separate experiments were conducted to determine the effects of exposure time at a constant temperature and varying endpoint exposure temperatures on the amount of bound protein by amino acid analysis. Bound amino acids were quantified and grouped by class based on functional side group. It was theorized that differences in the amount of bound amino acid class was linked to the mechanism by which the meat-to-film binding occurs. The protein solution was sealed in bags and held in a water bath for 5 s, 20 min, 40 min, and 60 min at 25.8 C for the timed experiment and heated from 25.8 C to 40, 55, 70, and 80 C for the temperature experiment. Protein adhesion occurred due to exposure of the solution to all films at 25.8 C. Greater protein adhesion was found in the two binding films than in the nonbinding film after 60 min of exposure. Heating the protein solution increased adhesion for the Surlyn film and showed a clear delineation in the degree of binding between the film types. Surlyn bound the most protein, followed by the nylon blend and then polyethylene. Bound protein increased in the Surlyn film with heating to 80 C, whereas the polyethylene did not show an increase in the amount of bound protein. Increases in binding observed between 55 and 80 C for Surlyn may be associated with transitional and conformational changes in muscle proteins that affect the adhesion of meat to the film surface. PMID:9603364

  15. Hot embossed polyethylene through-hole chips for bead-based microfluidic devices

    PubMed Central

    Chou, Jie; Du, Nan; Ou, Tina; Floriano, Pierre N.; Christodoulides, Nicolaos; McDevitt, John T.

    2013-01-01

    Over the past decade, there has been a growth of interest in the translation of microfluidic systems into real-world clinical practice, especially for use in point-of-care or near patient settings. While initial fabrication advances in microfluidics involved mainly the etching of silicon and glass, the economics of scaling of these materials is not amendable for point-of-care usage where single-test applications forces cost considerations to be kept low and throughput high. As such, a materials base more consistent with point-of-care needs is required. In this manuscript, the fabrication of a hot embossed, through-hole low-density polyethylene ensembles derived from an anisotropically etched silicon wafer is discussed. This semi-opaque polymer that can be easily sterilized and recycled provides low background noise for fluorescence measurements and yields more affordable cost than other thermoplastics commonly used for microfluidic applications such as cyclic olefin copolymer (COC). To fabrication through-hole microchips from this alternative material for microfluidics, a fabrication technique that uses a high-temperature, high-pressure resistant mold is described. This aluminum-based epoxy mold, serving as the positive master mold for embossing, is casted over etched arrays of pyramidal pits in a silicon wafer. Methods of surface treatment of the wafer prior to casting and PDMS casting of the epoxy are discussed to preserve the silicon wafer for future use. Changes in the thickness of polyethylene are observed for varying embossing temperatures. The methodology described herein can quickly fabricate 20 disposable, single use chips in less than 30 minutes with the ability to scale up 4x by using multiple molds simultaneously. When coupled as a platform supporting porous bead sensors, as in the recently developed Programmable Bio-Nano-Chip, this bead chip system can achieve limits of detection, for the cardiac biomarker C-reactive protein, of 0.3 ng/mL, thereby demonstrating the approach is compatible with high performance, real-world clinical measurements in the context of point-of-care testing. PMID:23183187

  16. Polyethylene glycol versus dual sugar assay for gastrointestinal permeability analysis: is it time to choose?

    PubMed Central

    van Wijck, Kim; Bessems, Babs AFM; van Eijk, Hans MH; Buurman, Wim A; Dejong, Cornelis HC; Lenaerts, Kaatje

    2012-01-01

    Background Increased intestinal permeability is an important measure of disease activity and prognosis. Currently, many permeability tests are available and no consensus has been reached as to which test is most suitable. The aim of this study was to compare urinary probe excretion and accuracy of a polyethylene glycol (PEG) assay and dual sugar assay in a double-blinded crossover study to evaluate probe excretion and the accuracy of both tests. Methods Gastrointestinal permeability was measured in nine volunteers using PEG 400, PEG 1500, and PEG 3350 or lactulose-rhamnose. On 4 separate days, permeability was analyzed after oral intake of placebo or indomethacin, a drug known to increase intestinal permeability. Plasma intestinal fatty acid binding protein and calprotectin levels were determined to verify compromised intestinal integrity after indomethacin consumption. Urinary samples were collected at baseline, hourly up to 5 hours after probe intake, and between 5 and 24 hours. Urinary excretion of PEG and sugars was determined using high-pressure liquid chromatography-evaporative light scattering detection and liquid chromatography-mass spectrometry, respectively. Results Intake of indomethacin increased plasma intestinal fatty acid-binding protein and calprotectin levels, reflecting loss of intestinal integrity and inflammation. In this state of indomethacin-induced gastrointestinal compromise, urinary excretion of the three PEG probes and lactulose increased compared with placebo. Urinary PEG 400 excretion, the PEG 3350/PEG 400 ratio, and the lactulose/rhamnose ratio could accurately detect indomethacin-induced increases in gastrointestinal permeability, especially within 2 hours of probe intake. Conclusion Hourly urinary excretion and diagnostic accuracy of PEG and sugar probes show high concordance for detection of indomethacin-induced increases in gastrointestinal permeability. This comparative study improves our knowledge of permeability analysis in man by providing a clear overview of both tests and demonstrates equivalent performance in the current setting. PMID:22888267

  17. Activity retention after nisin entrapment in a polyethylene oxide brush layer.

    PubMed

    Auxier, Julie A; Schilke, Karl F; McGuire, Joseph

    2014-09-01

    The cationic, amphiphilic peptide nisin is an effective inhibitor of gram-positive bacteria whose mode of action does not encourage pathogenic resistance, and its proper incorporation into food packaging could enhance food stability, safety, and quality in a number of circumstances. Sufficiently small peptides have been shown to integrate into otherwise nonfouling polyethylene oxide (PEO) brush layers in accordance with their amphiphilicity and ordered structure, including nisin, and we have recently shown that nisin entrapment within a PEO layer does not compromise the nonfouling character of that layer. In this work we test the hypothesis that surface-bound, pendant PEO chains will inhibit displacement of entrapped nisin by competing proteins and, in this way, prolong retention of nisin activity at the interface. For this purpose, the antimicrobial activity of nisinloaded, PEO-coated surfaces was evaluated against the gram-positive indicator strain, Pediococcus pentosaceous. The retained antimicrobial activity of nisin layers was evaluated on uncoated and PEO-coated surfaces after incubation in the presence of bovine serum albumin for contact periods up to 1 week. Nisin-loaded, uncoated and PEO-coated samples were withdrawn at selected times and were incubated on plates inoculated with P. pentosaceous to quantify nisin activity by determination of kill zone radii. Our results indicate that nisin activity is retained at a higher level for a longer period of time after entrapment within PEO than after direct adsorption in the absence of PEO, owing to inhibition of nisin exchange with dissolved protein afforded by the pendant PEO chains. PMID:25198858

  18. Anaphylactic Shock Caused by Ingestion of Polyethylene Glycol

    PubMed Central

    Lee, Sun Hee; Lee, Joung Il; Joo, Kwang Ro; Shin, Hyun Phil; Baek, Il Hyun; Jeon, Jung Won; Lim, Jun Uk; Lee, Jung Lok; Lee, Hyae Min; Cho, Young-Hak

    2015-01-01

    Colonoscopy is the current standard method for evaluation of the colon. The diagnostic accuracy and therapeutic safety of colonoscopy depend on the quality of colonic cleansing and preparation. Generally, all these preparations have been demonstrated to be safe for use in healthy individuals without significant comorbid conditions. Based on safety and efficacy concerns, polyethylene glycol (PEG) is most commonly utilized as a bowel preparation solution for colonoscopy. Adverse events in patients receiving PEG are mostly clinically non-significant. However, fatal adverse events rarely have been shown to occur in the few individuals who experience vomiting or aspiration. Anaphylactic shock associated with ingestion of PEG electrolyte solution is an extremely rare fatal complication, and reported mainly in Western countries. Here, we report the first case of anaphylactic shock following the ingestion of PEG solution in Korea. PMID:25691849

  19. Compatibilization of a polyethylene/polyamide 6 blend nanocomposite

    NASA Astrophysics Data System (ADS)

    Mistretta, M. C.; Ceraulo, M.; La Mantia, F. P.; Morreale, M.

    2014-05-01

    Polymer blends of incompatible components need to be compatibilized to give rise to a blend with good properties. At the same way, polymer/clay nanocomposites show the same problem because of different chemical nature of the polymer matrix and of the clay. Compatibilization is then necessary if an incompatible polymer blend is filled with an organomodified clay. In this work a polyethylene/polyamide 6 blend filled with an organomodified clay has been compatibilized with a maleic anyhidride grafted SEBS (styrene-ethylene-butylene-styrene) copolymer and a glicidylmethacrylate-ethylene copolymer. The results show that compatibilization improves the mechanical properties in terms of elongation at break; furthermore, an unexpected effect has been found, since going from the isotropic to the anisotropic material, a fragile-ductile transition occurs, with a significant increase of the elongation values.

  20. High-strength welds in metallocene Polypropylene/Polyethylene laminates

    PubMed

    Chaffin; Knutsen; Brant; Bates

    2000-06-23

    Spectacular advances in organometallic chemistry over the past two decades have resulted in single-site catalysts that are revolutionizing production of polyethylene (PE) and isotactic polypropylene (iPP). This report describes an unanticipated benefit of metallocene-catalyzed semicrystalline polyolefins, namely welded joint strengths in PE/iPP laminates that can exceed the cohesive strength of the constituents. We propose that interfacial polymer entanglements, established in the molten state and subsequently anchored in chain-folded lamellae upon crystallization, are responsible for this intrinsic property. The poor adhesion exhibited by traditional Ziegler-Natta-catalyzed polyolefins is shown to derive from the accumulation of amorphous polymer, a by-product of the polymerization reactions, at the interface. These results should facilitate fabrication and improve the properties of composites based on materials that dominate the plastics industry. PMID:10864863

  1. Poly(ethylene glycol) amphiphilic copolymer for anticancer drugs delivery.

    PubMed

    Feng, Runliang; Zhu, Wenxia; Teng, Fangfang; Liu, Na; Yang, Fengying; Meng, Ning; Song, Zhimei

    2015-01-01

    Poly(ethylene glycol) is a water-soluble polymer. Due to its high safety and biocompatibility, it has been widely used to prepare amphiphilic copolymers for drug delivery. These copolymers can enhance water-solubility of hydrophobic drugs, improve their pharmacokinetic parameters and control their release from corresponding nanocarriers formed by its self-assembly. Anticancer drugs have some shortcomings such as lower water-solubility, bad targeting and some serious side-effects, which limit their applications and are dangerous to patients. So encapsulation of anticancer drugs into nanocarriers originated from its copolymeric derivates can improve their absorption, distribution, metabolism and excretion with better release properties and activities against cancer cells, increase their therapeutic effects, and realize their passive or active target delivery through structure modification. Recent research development of its drug delivery systems for anticancer drugs will be discussed. PMID:25420636

  2. Hansen solubility parameters for polyethylene glycols by inverse gas chromatography.

    PubMed

    Adamska, Katarzyna; Voelkel, Adam

    2006-11-01

    Inverse gas chromatography (IGC) has been applied to determine solubility parameter and its components for nonionic surfactants--polyethylene glycols (PEG) of different molecular weight. Flory-Huggins interaction parameter (chi) and solubility parameter (delta(2)) were calculated according to DiPaola-Baranyi and Guillet method from experimentally collected retention data for the series of carefully selected test solutes. The Hansen's three-dimensional solubility parameters concept was applied to determine components (delta(d), delta(p), delta(h)) of corrected solubility parameter (delta(T)). The molecular weight and temperature of measurement influence the solubility parameter data, estimated from the slope, intercept and total solubility parameter. The solubility parameters calculated from the intercept are lower than those calculated from the slope. Temperature and structural dependences of the entopic factor (chi(S)) are presented and discussed. PMID:16920129

  3. A Molecular Mechanism of viscoelasticity in aligned polyethylene

    NASA Astrophysics Data System (ADS)

    Hammad, A.; Hasan, H.; Swinburne, T. D.; Khawaja, M.; Del-Rosso, S.; Iannucci, L.; Sutton, A. P.

    2015-03-01

    The key observed property of aligned polyethylene is its viscoelastic behaviour, which is traditionally fitted with Maxwell models. Although these empirical models are successful at reproducing the mechanical response of the material, they fail to capture the underlying molecular mechanisms that lead to the observed viscoelastic behaviour. We explain the observed viscoelastic behaviour in terms of the formation, interaction and movement of solitons, and relate these molecular mechanisms to the semi-crystalline microstructure of the material. Using Molecular Dynamics we demonstrate the following results: (a) The formation of solitons from interfaces between crystalline and amorphous regions (b) The transfer of tensile load between molecular chains (c) the pile-up of solitons in a molecular chain that allows the concentration of stress at particular points (d) The disassociation of solitons into ?-twistons at 300K. European Science Research Council (EPSRC).

  4. Modeling Low Density Polyethylene with Precisely Placed Butyl Branches

    NASA Astrophysics Data System (ADS)

    Rojas, Giovanni; Wagener, Kenneth B.

    Polyethylene (PE) is a commodity produced on a massive scale and also is one of the most studied macromolecules. Crystallinity can be controlled by copolymerizing ethylene with ?-olefins, producing a wide range of material responses. Physical properties of PE, obtained via ? olefin copolymerization, depend on the branch content that is directly related to the comonomer incorporation into the PE backbone. Materials with unknown primary structures are produced via chaingrowth chemistry, because unwanted side reactions generate defects in the main backbone that alter the morphological behavior and thermal response. Acyclic diene metathesis (ADMET) polymerization/hydrogenation methodology produce perfect sequenced copolymers of ethylene with ?-olefins. Synthesis and thermal properties of PE with butyl branches precisely placed along the polymer backbone using ADMET chemistry is described within.

  5. Horseradish Peroxidase Inactivation: Heme Destruction and Influence of Polyethylene Glycol

    PubMed Central

    Mao, Liang; Luo, Siqiang; Huang, Qingguo; Lu, Junhe

    2013-01-01

    Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to support the hypothesis that HRP is inactivated by heme destruction. Product of heme destruction is identified using liquid chromatography with mass spectrometry. The heme macrocycle destruction involving deprivation of the heme iron and oxidation of the 4-vinyl group in heme occurs as a result of the reaction. We also demonstrated that heme consumption and iron releases resulting from HRP destruction are largely reduced in the presence of polyethylene glycol (PEG), providing the first evidence to indicate that heme destruction is effectively suppressed by co-dissolved PEG. These findings advance a better understanding of the mechanisms of HRP inactivation. PMID:24185130

  6. Antibacterial Performance of Alginic Acid Coating on Polyethylene Film

    PubMed Central

    Karbassi, Elika; Asadinezhad, Ahmad; Lehocký, Marian; Humpolí?ek, Petr; Vesel, Alenka; Novák, Igor; Sáha, Petr

    2014-01-01

    Alginic acid coated polyethylene films were examined in terms of surface properties and bacteriostatic performance against two most representative bacterial strains, that is, Escherichia coli and Staphylococcus aureus. Microwave plasma treatment followed by brush formation in vapor state from three distinguished precursors (allylalcohol, allylamine, hydroxyethyl methacrylate) was carried out to deposit alginic acid on the substrate. Surface analyses via various techniques established that alginic acid was immobilized onto the surface where grafting (brush) chemistry influenced the amount of alginic acid coated. Moreover, alginic acid was found to be capable of bacterial growth inhibition which itself was significantly affected by the brush type. The polyanionic character of alginic acid as a carbohydrate polymer was assumed to play the pivotal role in antibacterial activity. The cell wall composition of two bacterial strains along with the substrates physicochemical properties accounted for different levels of bacteriostatic performance. PMID:25196604

  7. Chain Ends and the Ultimate Strength of Polyethylene Fibers

    E-print Network

    Thomas C. O'Connor; Mark O. Robbins

    2015-11-20

    We use large scale molecular dynamics (MD) simulations to determine the tensile yield mechanism of orthorhombic polyethylene (PE) crystals with finite chains spanning $10^2-10^4$ carbons in length. We find the yield stress $\\sigma_y$ saturates for long chains at 6.3 GPa, agreeing well with experiments. We show chains do not break but always yield by slip, after nucleation of 1D dislocations at chain ends. Dislocations are accurately described by a Frenkel-Kontorova model parametrized by the mechanical properties of an ideal crystal. We compute a dislocation core size $\\xi\\approx25$\\AA\\ and determine the high and low strain rate limits of $\\sigma_y$. Our results suggest characterizing the 1D dislocations of polymer crystals as an efficient method for numerically predicting the ultimate tensile strength of aligned fibers.

  8. The characterisation of two different degradable polyethylene (PE) sacks

    SciTech Connect

    Davis, G. . E-mail: gudavis@cytanet.com.cy

    2006-12-15

    The compostability of two different polyethylene (PE) products on the UK market under open-windrow composting conditions is explored within this paper. Chemical analysis of the PE bags has established their constituents in order to examine how the PE bags have an increased degradability depending on additives. Weight loss of the two different PE products within open-windrow composting conditions was recorded in order to establish the percentage weight loss as an indication of the degradability of the two products and their relative suitability for open-windrow composting. Scanning electron microscopy (SEM) of the PE products over the composting duration established the degradation processes for the PE products within the compost. These analyses concluded that one of the PE product mixes was more degradable than the other. However, neither product completed degraded within the timeframe of 12-14 weeks generally accepted for open-windrow composting in the UK.

  9. Polyethylene glycol diffusion in ex vivo skin tissue

    NASA Astrophysics Data System (ADS)

    Genin, V. D.; Tuchina, D. K.; Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.

    2015-11-01

    Optical clearing of the rat skin under the action of polyethylene glycol (PEG) with molecular weight 300 and 400 Dalton was studied ex vivo. The collimated transmittance was measured at the wavelength range 500-900 nm. It was found that collimated transmittance of skin samples increased, whereas weight, thickness and area of the samples decreased during PEG penetration in skin tissue. A mechanism of the optical clearing under the action of PEG is discussed. Taking into account the kinetics of volume and thickness of the skin samples, diffusion coefficient of PEGs in skin tissue has been estimated as (1.83±2.22)×10-6 cm2/s and (1.70±1.47)×10-6 cm2/s for PEG-300 and PEG-400, respectively. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  10. Simulation of polyethylene glycol and calcium-mediated membrane fusion

    SciTech Connect

    Pannuzzo, Martina; De Jong, Djurre H.; Marrink, Siewert J.; Raudino, Antonio

    2014-03-28

    We report on the mechanism of membrane fusion mediated by polyethylene glycol (PEG) and Ca{sup 2+} by means of a coarse-grained molecular dynamics simulation approach. Our data provide a detailed view on the role of cations and polymer in modulating the interaction between negatively charged apposed membranes. The PEG chains cause a reduction of the inter-lamellar distance and cause an increase in concentration of divalent cations. When thermally driven fluctuations bring the membranes at close contact, a switch from cis to trans Ca{sup 2+}-lipid complexes stabilizes a focal contact acting as a nucleation site for further expansion of the adhesion region. Flipping of lipid tails induces subsequent stalk formation. Together, our results provide a molecular explanation for the synergistic effect of Ca{sup 2+} and PEG on membrane fusion.

  11. Use of fillers to enable the microwave processing of polyethylene.

    PubMed

    Harper, John; Price, Duncan; Zhang, Jie

    2007-01-01

    Microwave heating has a number of advantages over conventional heating due to the ability to heat specimens directly through specific interaction of electromagnetic radiation with the material. Thus it is possible to consider highly localised, rapid melting of thermoplastics using microwave radiation as a means of forming and welding. However, most polymers exhibit very low dielectric losses in the GHz region, which means that it is difficult to heat them efficiently by this means. We have therefore studied the use of fillers such as talc, zinc oxide and carbon black as a way of increasing the susceptibility of common polymers to microwave processing. Carbon black was found to be the most effective susceptor for high density polyethylene and its efficiency was directly proportional to its surface area and loading. PMID:17847676

  12. Silk fibroin and polyethylene glycol-based biocompatible tissue adhesives.

    PubMed

    Serban, Monica A; Panilaitis, Bruce; Kaplan, David L

    2011-09-15

    Tissue sealants have emerged in recent years as strong candidates for hemostasis. A variety of formulations are currently commercially available and though they satisfy many of the markets' needs there are still key aspects of each that need improvement. Here we present a new class of blends, based on silk fibroin and chemically active polyethylene glycols (PEGs) with strong adhesive properties. These materials are cytocompatible, crosslink within seconds via chemical reaction between thiols and maleimides present on the constituent PEGs and have the potential to further stabilize through ?-sheet formation by silk. Based on the silk concentration in the final formulation, the adhesive properties of these materials are comparable or better than the current leading PEG-based sealant. In addition, the silk-PEG based materials show decreased swelling and longer degradation times. Such properties would make them suitable for applications for which the current sealants are contraindicated. PMID:21681949

  13. Irradiation of linear polyethylene - Partitioning between sol and gel.

    NASA Technical Reports Server (NTRS)

    Rijke, A. M.; Mandelkern, L.

    1971-01-01

    Molecular weight fractions of linear polyethylene were irradiated at 133 C, in the completely molten and highly crystalline states, for the purpose of assessing the importance of chain-scission processes and establishing the critical conditions for gelation. The partitioning between sol and gel in either state was found to adhere to the theory for the intermolecular cross-linking of monodisperse species for dosages just beyond the gel point. Deviations from theory occurred as the dosage was increased further. It was concluded that main-chain scission, at these temperatures, is not a significant process. High molecular weight samples in the completely molten state obeyed the Flory-Stockmayer condition for critical gelation.

  14. Fracture of composites based on polyethylene and elastic particles

    NASA Astrophysics Data System (ADS)

    Serenko, O. A.; Karaeva, A. A.; Goncharuk, G. P.; Zaderenko, T. V.; Bazhenov, S. L.

    2009-06-01

    The composites based on low-density polyethylene with elastomer filling particles are studied. A fracture mechanism induced by the fracture of filler particles or their separation from the matrix polymer is revealed. The fracture of the composites is caused by the growth of formed rhombic pores. The natural relative elongation in a neck is shown to be an important characteristic of a polymer. If the relative elongation in a neck is lower than the strain of appearance of rhombic pores, they form at the stage of uniform tension after necking, and the composite remains plastic. If the relative elongation in a neck is higher than the strain of formation of rhombic pores, they nucleate during necking, and the material undergoes quasi-brittle fracture. Good adhesion between the matrix polymer and elastic particles hinders the appearance of rhombic pores in a neck and, thus, retains high deformation properties of the composites.

  15. In vitro antibacterial activity of concentrated polyethylene glycol 400 solutions.

    PubMed Central

    Chirife, J; Herszage, L; Joseph, A; Bozzini, J P; Leardini, N; Kohn, E S

    1983-01-01

    It was found that concentrated polyethylene glycol 400 (PEG 400) solutions have significant antibacterial activity against various pathogenic bacteria, including Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. This effect might be attributed to two effects: lowering of water activity and, superimposed on this, the specific action of PEG-400 molecules on bacterial cells. Phase-contrast microscopic observations of cells placed in contact with PEG 400 revealed clumping and morphological changes of bacterial cells. The larger changes in appearance were evidenced by the species which were more rapidly killed by PEG 400. The results obtained suggested that concentrated PEG 400 solutions may have a potential value in medicine as a topical antibacterial agent. The feasibility of this application is the subject of present investigation. Images PMID:6638996

  16. Electrospun Polyaniline/Polyethylene Oxide Nanofiber Field Effect Transistor

    NASA Technical Reports Server (NTRS)

    Pinto, N. J.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.

    2003-01-01

    We report on the observation of field effect transistor (FET) behavior in electrospun camphorsulfonic acid doped polyaniline(PANi)/polyethylene oxide(PE0) nanofibers. Saturation channel currents are observed at surprisingly low source/drain voltages. The hole mobility in the depletion regime is 1.4 x 10(exp -4) sq cm/V s while the 1-D charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx. 10(exp -3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating 1-D polymer FET's.

  17. Polymer crystal-melt interfaces and nucleation in polyethylene

    E-print Network

    Scott T. Milner

    2010-09-22

    Kinetic barriers cause polymers to crystallize incompletely, into nanoscale lamellae interleaved with amorphous regions. As a result, crystalline polymers are full of crystal-melt interfaces, which dominate their physical properties. The longstanding theoretical challenge to understand these interfaces has new relevance, because of accumulating evidence that polymer crystals often nucleate via a metastable, partially ordered "rotator" phase. To test this idea requires a theory of the bulk and interfacial free energies of the critical nucleus. We present a new approach to the crystal-melt interface, which represents the amorphous region as a grafted brush of loops in a self-consistent pressure field. We combine this theory with estimates of bulk free energy differences, to calculate nucleation barriers and rates via rotator versus crystal nuclei for polyethylene. We find rotator-phase nucleation is indeed favored throughout the temperature range where nucleation is observed. Our methods can be extended to other polymers.

  18. Textural changes in metallurgical coke prepared with polyethylene

    NASA Astrophysics Data System (ADS)

    Gornostayev, Stanislav S.; Heino, Jyrki J.; Kokkonen, Tommi M. T.; Makkonen, Hannu T.; Huttunen, Satu M. M.; Fabritius, Timo M. J.

    2014-10-01

    The effect of high-density polyethylene (HDPE) on the textural features of experimental coke was investigated using polarized-light optical microscopy and wavelet-based image analysis. Metallurgical coke samples were prepared in a laboratory-scale furnace with 2.5%, 5.0%, 7.5%, 10.0%, and 12.5% HDPE by mass, and one sample was prepared by 100% coal. The amounts and distribution of textures (isotropic, mosaic and banded) and pores were obtained. The calculations reveal that the addition of HDPE results in a decrease of mosaic texture and an increase of isotropic texture. Ethylene formed from the decomposition of HDPE is considered as a probable reason for the texture modifications. The approach used in this study can be applied to indirect evaluation for the reactivity and strength of coke.

  19. Silk fibroin and polyethylene glycol-based biocompatible tissue adhesives

    PubMed Central

    Serban, Monica A.; Panilaitis, Bruce; Kaplan, David L.

    2012-01-01

    Tissue sealants have emerged in recent years as strong candidates for hemostasis. A variety of formulations are currently commercially available and though they satisfy many of the markets’ needs there are still key aspects of each that need improvement. Here we present a new class of blends, based on silk fibroin and chemically active polyethylene glycols (PEGs) with strong adhesive properties. These materials are cytocompatible, crosslink within seconds via chemical reaction between thiols and maleimides present on the constituent PEGs and have the potential to further stabilize through ?-sheet formation by silk. Based on the silk concentration in the final formulation, the adhesive properties of these materials are comparable or better than the current leading PEG-based sealant. In addition, the silk-PEG based materials show decreased swelling and longer degradation times. Such properties would make them suitable for applications for which the current sealants are contraindicated. PMID:21681949

  20. Gels and foams from ultrahigh molecular weight polyethylene

    SciTech Connect

    Hair, L.M.; Letts, S.A.; Tillotson, T.

    1988-07-01

    Ultrahigh molecular weight polyethylene (UHMW PE) foams with densities from 0.04 to 0.2 g/cm{sup 3} have routinely been made in our laboratory. First, an entangled solution of UHMW PE is made. Then, the solution is geled by cooling to crystallize the PE. The gel is later dried to a foam by critical point drying. Viscometry and cloud point measurements were used to determine the gelatin point and the critical gelatin concentrations. Polarized light microscopy and differential scanning calorimetry were used to investigate the effects of cooling rate on the gel, while the effects of cooling rate on the foam were investigated via x-ray diffraction and scanning electron microscopy. We found that rapid cooling of 5 wt % UHMW PE/tetralin solutions to {minus}10{degree}c yielded small, uniform structure at the expense of crystallinity and strength; cooling over three days yielded spherulitic structure with strength. 5 refs., 3 figs.

  1. Preparation of polyethylene sacks for collection of precipitation samples for chemical analysis

    USGS Publications Warehouse

    Schroder, L.J.; Bricker, A.W.

    1985-01-01

    Polyethylene sacks are used to collect precipitation samples. Washing polyethylene with acetone, hexane, methanol, or nitric acid can change the adsorptive characteristics of the polyethylene. In this study, simulated precipitation at pH 4.5 was in contact with the polyethylene sacks for 21 days; subsamples were removed for chemical analysis at 7, 14, and 21 days after intitial contact. Sacks washed with acetone adsorbed iron and lithium; sacks washed with hexane adsorbed barium, iron , and lithium; sacks washed with methanol adsorbed calcium and iron; and sacks washed with 0.30 N nitric acid adsorbed iron. Leaching the plastic sacks with 0.15 N nitric acid did not result in 100-percent recovery of any of the adsorbed metals. Washing polyethylene sacks with dilute nitric acid caused the pH of the simulated precipitation to be decreased by 0.2 pH unit after 1 week of contact with the polyethylene. The specific conductance increased by 10 microsiemens per centimeter. Contamination of precipitation samples by lead was determined to be about 0.1 microgram per liter from contact with precleaned polyethylene sacks. No measurable contamination of precipitation samples by zinc occurred. (USGS)

  2. Influence of Pelvic Tilt on Polyethylene Wear after Total Hip Arthroplasty

    PubMed Central

    Tezuka, Taro; Inaba, Yutaka; Kobayashi, Naomi; Ike, Hiroyuki; Kubota, So; Kawamura, Masaki; Saito, Tomoyuki

    2015-01-01

    We aimed to evaluate the effects of pelvic tilt on polyethylene wear after total hip arthroplasty (THA). A total of 105 joints treated with primary THA were included; conventional polyethylene (CPE) liners were used in 43 hips and highly cross-linked polyethylene (HXLPE) liners were used in the remaining 62 hips. The pelvis was tilted 6° posteriorly in the standing position as compared to the supine position, which resulted in significant increases of 1.7° and 2.8° in cup inclination in the CPE and HXLPE groups, respectively. Moreover, the change in pelvic tilt resulted in significant increases of 3.6° and 4.9° in cup anteversion in the CPE and HXLPE groups, respectively. For the CPE group, multiple regression analysis showed a significant association between the angle of pelvic tilt (PTA) and cup inclination and the polyethylene wear ratio. The adjusted R2 of the regression model was larger for measures obtained in the standing position as compared to the supine position. For the HXLPE group, there was no significant relationship between radiographic parameters and polyethylene wear. Close observation of polyethylene wear is recommended for patients with severe posterior pelvic tilt who have undergone THA with conventional polyethylene. PMID:26258136

  3. Protein nanorings organized by poly(styrene-block-ethylene oxide) self-assembled thin films.

    PubMed

    Malmström, Jenny; Wason, Akshita; Roache, Fergus; Yewdall, N Amy; Radjainia, Mazdak; Wei, Shanghai; Higgins, Michael J; Williams, David E; Gerrard, Juliet A; Travas-Sejdic, Jadranka

    2015-12-21

    This study explores the use of block copolymer self-assembly to organize Lsm?, a protein which forms stable doughnut-shaped heptameric structures. Here, we have explored the idea that 2-D crystalline arrays of protein filaments can be prepared by stacking doughnut shaped Lsm? protein into the poly(ethylene oxide) blocks of a hexagonal microphase-separated polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer. We were able to demonstrate the coordinated assembly of such a complex hierarchical nanostructure. The key to success was the choice of solvent systems and protein functionalization that achieved sufficient compatibility whilst still promoting assembly. Unambiguous characterisation of these structures is difficult; however AFM and TEM measurements confirmed that the protein was sequestered into the PEO blocks. The use of a protein that assembles into stackable doughnuts offers the possibility of assembling nanoscale optical, magnetic and electronic structures. PMID:26499391

  4. Supramolecular Protein Immobilization on Lipid Bilayers.

    PubMed

    Bosmans, Ralph P G; Hendriksen, Wouter E; Verheijden, Mark; Eelkema, Rienk; Jonkheijm, Pascal; van Esch, Jan H; Brunsveld, Luc

    2015-12-01

    Protein immobilization on surfaces, and on lipid bilayers specifically, has great potential in biomolecular and biotechnological research. Of current special interest is the immobilization of proteins using supramolecular noncovalent interactions. This allows for a reversible immobilization and obviates the use of harsh ligation conditions that could denature fragile proteins. In the work presented here, reversible supramolecular immobilization of proteins on lipid bilayer surfaces was achieved by using the host-guest interaction of the macrocyclic molecule cucurbit[8]uril. A fluorescent protein was successfully immobilized on the lipid bilayer by making use of the property of cucurbit[8]uril to host together a methylviologen and the indole of a tryptophan positioned on the N-terminal of the protein. The supramolecular complex was anchored to the bilayer through a cholesterol moiety that was attached to the methylviologen tethered with a small polyethylene glycol spacer. Protein immobilization studies using a quartz crystal microbalance (QCM) showed the assembly of the supramolecular complexes on the bilayer. Specific immobilization through the protein N-terminus is more efficient than through protein side-chain events. Reversible surface release of the proteins could be achieved by washing with cucurbit[8]uril or buffer alone. The described system shows the potential of supramolecular assembly of proteins and provides a method for site-specific protein immobilization under mild conditions in a reversible manner. PMID:26527541

  5. Enhanced Cutinase-Catalyzed Hydrolysis of Polyethylene Terephthalate by Covalent Fusion to Hydrophobins

    PubMed Central

    Ribitsch, Doris; Herrero Acero, Enrique; Przylucka, Agnieszka; Zitzenbacher, Sabine; Marold, Annemarie; Gamerith, Caroline; Tscheließnig, Rupert; Jungbauer, Alois; Rennhofer, Harald; Lichtenegger, Helga; Amenitsch, Heinz; Bonazza, Klaus; Kubicek, Christian P.; Guebitz, Georg M.

    2015-01-01

    Cutinases have shown potential for hydrolysis of the recalcitrant synthetic polymer polyethylene terephthalate (PET). We have shown previously that the rate of this hydrolysis can be enhanced by the addition of hydrophobins, small fungal proteins that can alter the physicochemical properties of surfaces. Here we have investigated whether the PET-hydrolyzing activity of a bacterial cutinase from Thermobifida cellulosilytica (Thc_Cut1) would be further enhanced by fusion to one of three Trichoderma hydrophobins, i.e., the class II hydrophobins HFB4 and HFB7 and the pseudo-class I hydrophobin HFB9b. The fusion enzymes exhibited decreased kcat values on soluble substrates (p-nitrophenyl acetate and p-nitrophenyl butyrate) and strongly decreased the hydrophilicity of glass but caused only small changes in the hydrophobicity of PET. When the enzyme was fused to HFB4 or HFB7, the hydrolysis of PET was enhanced >16-fold over the level with the free enzyme, while a mixture of the enzyme and the hydrophobins led only to a 4-fold increase at most. Fusion with the non-class II hydrophobin HFB9b did not increase the rate of hydrolysis over that of the enzyme-hydrophobin mixture, but HFB9b performed best when PET was preincubated with the hydrophobins before enzyme treatment. The pattern of hydrolysis by the fusion enzymes differed from that of Thc_Cut1 as the concentration of the product mono(2-hydroxyethyl) terephthalate relative to that of the main product, terephthalic acid, increased. Small-angle X-ray scattering (SAXS) analysis revealed an increased scattering contrast of the fusion proteins over that of the free proteins, suggesting a change in conformation or enhanced protein aggregation. Our data show that the level of hydrolysis of PET by cutinase can be significantly increased by fusion to hydrophobins. The data further suggest that this likely involves binding of the hydrophobins to the cutinase and changes in the conformation of its active center. PMID:25795674

  6. Graphite/Ultra-High Modulus Polyethylene Hybrid Fiber Composites with Epoxy and Polyethylene Matrices for Cosmic Radiation Shielding

    NASA Technical Reports Server (NTRS)

    2003-01-01

    One of the most significant technical challenges in long-duration space missions is that of protecting the crew from harmful radiation. Protection against such radiation on a manned Mars mission will be of vital importance both during transit and while on the surface of the planet. The development of multifunctional materials that serve as integral structural members of the space vehicle and provide the necessary radiation shielding for the crew would be both mission enabling and cost effective. Additionally, combining shielding and structure could reduce total vehicle mass. Hybrid laminated composite materials having both ultramodulus polyethylene (PE) and graphite fibers in epoxy and PE matrices could meet such mission requirements. PE fibers have excellent physical properties, including the highest specific strength of any known fiber. Moreover, the high hydrogen (H) content of polyethylene makes the material an excellent shielding material for cosmic radiation. When such materials are incorporated into an epoxy or PE matrix a very effective shielding material is expected. Boron (B) may be added to the matrix resin or used as a coating to further increase the shielding effectiveness due to B s ability to slow thermal neutrons. These materials may also serve as micrometeorites shields due to PE s high impact energy absorption properties. It should be noted that such materials can be fabricated by existing equipment and methods. It is the objective of this work therefore to: (a) perform preliminary analysis of the radiation transport within these materials; (b) fabricate panels for mechanical property testing before and after radiation exposure. Preliminary determination on the effectiveness of the combinations of material components on both shielding and structural efficiency will be made.

  7. Methods for increasing the thermal conductivity of ultra-high molecular weight polyethylene (UHMWPE)

    E-print Network

    Miler, Josef L

    2006-01-01

    A two-part study was conducted to determine methods for producing ultra-high molecular weight polyethylene with high thermal conductivity by way of polymer chain orientation. The first portion of this report surveys current ...

  8. 76 FR 39855 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Duty Order, Finding, or Suspended Investigation; Opportunity to Request an Administrative Review, 75 FR... Countervailing Duty Administrative Reviews and Deferral of Initiation of Administrative Review, 75 FR 53274... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission,...

  9. 76 FR 39855 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Order, Finding, or Suspended Investigation; Opportunity to Request an Administrative Review, 75 FR 38074... Countervailing Duty Administrative Reviews and Deferral of Initiation of Administrative Review, 75 FR 53274... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission,...

  10. Composite Polymer Electrolytes Based on Poly(ethylene glycol) and Hydrophobic Fumed Silica: Dynamic

    E-print Network

    Raghavan, Srinivasa

    utilized in electrolyte processing. Introduction Rechargeable lithium batteries employing solid elec electrolytes based on poly(ethylene oxide) (PEO).1 Solid polymer electrolytes can potentially eliminate battery* Department of Chemical Engineering, North Carolina State University, Raleigh, North Carolina 27695

  11. 75 FR 22842 - Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ...Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam Determinations...material injury by reason of imports from Indonesia, Taiwan, and Vietnam of PRCBs that...by Commerce that imports of PRCBs from Indonesia, Taiwan, and Vietnam were being...

  12. Limitations of Reverse Polyethylene Samplers (RePES) for Evaluating Toxicity of Field Contaminated Sediments

    EPA Science Inventory

    Passive samplers are used to measure dissolved nonionic organic contaminants (NOCs) in environmental media. More recently, reverse polyethylene samplers (RePES) have been used with spiked sediments to recreate interstitial water exposure concentrations and observed toxicity. In...

  13. Use of prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent

    NASA Astrophysics Data System (ADS)

    Priyada, P.; Sarkar, P. K.

    2015-06-01

    The possibility of using measured prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent is explored theoretically. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of a high density polyethylene cylinder to emit prompt gammas from interaction of neutrons with the nuclei of hydrogen and carbon present in polyethylene. The neutron energy dependent responses of hydrogen and carbon nuclei are combined appropriately to match the energy dependent neutron fluence to ambient dose equivalent conversion coefficients. The proposed method is tested initially with simulated spectra and then validated using experimental measurements with an Am-Be neutron source. Experimental measurements and theoretical simulations have established the feasibility of estimating neutron ambient dose equivalent using measured neutron induced prompt gammas emitted from polyethylene with an overestimation of neutron dose at very low energies.

  14. Effectiveness of Vitamin-E-Doped Polyethylene in Joint Replacement: A Literature Review

    PubMed Central

    Gigante, Antonio; Bottegoni, Carlo; Ragone, Vincenza; Banci, Lorenzo

    2015-01-01

    Since polyethylene is one of the most frequently used biomaterials, such as in bearing components in joint arthroplasty, strong efforts have been made to improve the design and material properties over the last decades. Antioxidants, such as vitamin-E, seem to be a promising alternative to further increase durability and reduce polyethylene wear and degradation in the long-term. Nevertheless, even if several promising in vitro results are available, there is yet no clinical evidence that vitamin-E polyethylenes show these advantages in vivo. The aim of this paper was to provide a comprehensive overview on the current knowledge regarding the biological and mechanical proprieties of this biomaterial, underlying the in vitro and in vivo evidence for effectiveness of vitamin-E-doped polyethylene in joint arthroplasty. PMID:26371052

  15. 76 FR 48122 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-08

    ...Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty...sheet, and strip (PET film) from Brazil. This administrative review covers one...antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate...

  16. 75 FR 49900 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ...Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty...sheet, and strip (PET film) from Brazil. This administrative review covers one...antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate...

  17. Polyethylene/Potassium Titanate Separators For Ni/H2 Cells

    NASA Technical Reports Server (NTRS)

    Scott, William E.

    1995-01-01

    Experimental separators fabricated on paper-making machine. Two-layer, paperlike composite of polyethylene fibers and potassium titanate pigment shows promise for replacing asbestos as separator material in nickel/hydrogen electrochemical cells.

  18. The effect of different particle sizes of polyethylene on the absorption of myrrh in mixtures

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Li, Bin; Zuo, Jian; Zhang, Cunlin

    2015-08-01

    Terahertz radiation lies between far-infrared and microwave in electromagnetic spectrum with frequency from 0.1 to 10 THz. Absorption spectra of different mass ratio of the myrrh and polyethylene can be gained by Fourier transform infrared spectrometer in this paper. It is found that absorption spectra show a slight red-shift with the decrease of the mass ratio of myrrh and polyethylene. On the other hand, different particle sizes of polyethylene (PE) mixed with myrrh absorption spectra were measured. Due to the different sizes of polyethylene particles, there are some differences in the vibration peak intensity, peak position and peak numbers in the absorption spectra. The experimental results show that the scattering effect leads to this phenomenon.

  19. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...New Uses for Specific Chemical Substances § 721...triethoxysilyl)-, reaction products with polyethylene...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...triethoxysilyl)-, reaction products with...

  20. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...New Uses for Specific Chemical Substances § 721...triethoxysilyl)-, reaction products with polyethylene...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...triethoxysilyl)-, reaction products with...

  1. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...triethoxysilyl)-, reaction products with polyethylene...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...triethoxysilyl)-, reaction products with...

  2. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following specifications: Saponification number, 80-88; acid number, 5.0 maximum; and average molecular weight range, 640-680. (b) It is used...

  3. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following specifications: Saponification number, 80-88; acid number, 5.0 maximum; and average molecular weight range, 640-680. (b) It is used...

  4. 75 FR 53953 - Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ...Results of Antidumping Duty Administrative Review AGENCY: Import Administration, International...Department) is conducting an administrative review of the antidumping duty order on polyethylene...carrier bags (PRCBs) from Thailand. The review covers five exporters/producers....

  5. Extremely High Thermal Conductivity of Aligned Carbon Nanotube-Polyethylene Composites

    NASA Astrophysics Data System (ADS)

    Liao, Quanwen; Liu, Zhichun; Liu, Wei; Deng, Chengcheng; Yang, Nuo

    2015-11-01

    The ultra-low thermal conductivity of bulk polymers may be enhanced by combining them with high thermal conductivity materials such as carbon nanotubes. Different from random doping, we find that the aligned carbon nanotube-polyethylene composites has a high thermal conductivity by non-equilibrium molecular dynamics simulations. The analyses indicate that the aligned composite not only take advantage of the high thermal conduction of carbon nanotubes, but enhance thermal conduction of polyethylene chains.

  6. Layer-by-layer assembly on polyethylene films via "click" chemistry 

    E-print Network

    Chance, Brandon Scott

    2009-05-15

    -BY-LAYER ASSEMBLY ON POLYETHYLENE FILMS VIA ?CLICK? CHEMISTRY A Thesis by BRANDON SCOTT CHANCE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 2007 Major Subject: Chemistry LAYER-BY-LAYER ASSEMBLY ON POLYETHYLENE FILMS VIA ?CLICK? CHEMISTRY A Thesis by BRANDON SCOTT CHANCE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

  7. Extremely High Thermal Conductivity of Aligned Carbon Nanotube-Polyethylene Composites

    PubMed Central

    Liao, Quanwen; Liu, Zhichun; Liu, Wei; Deng, Chengcheng; Yang, Nuo

    2015-01-01

    The ultra-low thermal conductivity of bulk polymers may be enhanced by combining them with high thermal conductivity materials such as carbon nanotubes. Different from random doping, we find that the aligned carbon nanotube-polyethylene composites has a high thermal conductivity by non-equilibrium molecular dynamics simulations. The analyses indicate that the aligned composite not only take advantage of the high thermal conduction of carbon nanotubes, but enhance thermal conduction of polyethylene chains. PMID:26552843

  8. Production of an extracellular polyethylene-degrading enzyme(s) by Streptomyces species.

    PubMed

    Pometto, A L; Lee, B T; Johnson, K E

    1992-02-01

    Extracellular culture concentrates were prepared from Streptomyces viridosporus T7A, Streptomyces badius 252, and Streptomyces setonii 75Vi2 shake flask cultures. Ten-day-heat-treated (70 degrees C) starch-polyethylene degradable plastic films were incubated with shaking with active or inactive enzyme for 3 weeks (37 degrees C). Active enzyme illustrated changes in the films' Fourier transform infrared spectra, mechanical properties, and polyethylene molecular weight distributions. PMID:1610196

  9. Extremely High Thermal Conductivity of Aligned Carbon Nanotube-Polyethylene Composites.

    PubMed

    Liao, Quanwen; Liu, Zhichun; Liu, Wei; Deng, Chengcheng; Yang, Nuo

    2015-01-01

    The ultra-low thermal conductivity of bulk polymers may be enhanced by combining them with high thermal conductivity materials such as carbon nanotubes. Different from random doping, we find that the aligned carbon nanotube-polyethylene composites has a high thermal conductivity by non-equilibrium molecular dynamics simulations. The analyses indicate that the aligned composite not only take advantage of the high thermal conduction of carbon nanotubes, but enhance thermal conduction of polyethylene chains. PMID:26552843

  10. Effect of polyethylene glycol on the liquidliquid phase transition in aqueous protein solutions

    E-print Network

    Benedek, George B.

    that the phase separation temperature increases with both PEG con- centration and PEG molecular weight. PEG temperature and PEG partitioning in the ternary D-PEG- water systems are used to successfully predict measured experimentally and observed to increase with PEG molecular weight. The measurements of both LLPS

  11. Biodegradation of degradable plastic polyethylene by phanerochaete and streptomyces species.

    PubMed

    Lee, B; Pometto, A L; Fratzke, A; Bailey, T B

    1991-03-01

    The ability of lignin-degrading microorganisms to attack degradable plastics was investigated in pure shake flask culture studies. The degradable plastic used in this study was produced commercially by using the Archer-Daniels-Midland POLYCLEAN masterbatch and contained pro-oxidant and 6% starch. The known lignin-degrading bacteria Streptomyces viridosporus T7A, S. badius 252, and S. setonii 75Vi2 and fungus Phanerochaete chrysosporium were used. Pro-oxidant activity was accelerated by placing a sheet of plastic into a drying oven at 70 degrees C under atmospheric pressure and air for 0, 4, 8, 12, 16, or 20 days. The effect of 2-, 4-, and 8-week longwave UV irradiation at 365 nm on plastic biodegradability was also investigated. For shake flask cultures, plastics were chemically disinfected and incubated-shaken at 125 rpm at 37 degrees C in 0.6% yeast extract medium (pH 7.1) for Streptomyces spp. and at 30 degrees C for the fungus in 3% malt extract medium (pH 4.5) for 4 weeks along with an uninoculated control for each treatment. Weight loss data were inconclusive because of cell mass accumulation. For almost every 70 degrees C heat-treated film, the Streptomyces spp. demonstrated a further reduction in percent elongation and polyethylene molecular weight average when compared with the corresponding uninoculated control. Significant (P < 0.05) reductions were demonstrated for the 4- and 8-day heat-treated films by all three bacteria. Heat-treated films incubated with P. chrysosporium consistently demonstrated higher percent elongation and molecular weight average than the corresponding uninoculated controls, but were lower than the corresponding zero controls (heat-treated films without 4-week incubation). The 2- and 4-week UV-treated films showed the greatest biodegradation by all three bacteria. Virtually no degradation by the fungus was observed. To our knowledge, this is the first report demonstrating bacterial degradation of these oxidized polyethylenes in pure culture. PMID:16348434

  12. Introduction to current and future protein therapeutics: A protein engineering perspective

    SciTech Connect

    Carter, Paul J.

    2011-05-15

    Protein therapeutics and its enabling sister discipline, protein engineering, have emerged since the early 1980s. The first protein therapeutics were recombinant versions of natural proteins. Proteins purposefully modified to increase their clinical potential soon followed with enhancements derived from protein or glycoengineering, Fc fusion or conjugation to polyethylene glycol. Antibody-based drugs subsequently arose as the largest and fastest growing class of protein therapeutics. The rationale for developing better protein therapeutics with enhanced efficacy, greater safety, reduced immunogenicity or improved delivery comes from the convergence of clinical, scientific, technological and commercial drivers that have identified unmet needs and provided strategies to address them. Future protein drugs seem likely to be more extensively engineered to improve their performance, e.g., antibodies and Fc fusion proteins with enhanced effector functions or extended half-life. Two old concepts for improving antibodies, namely antibody-drug conjugates and bispecific antibodies, have advanced to the cusp of clinical success. As for newer protein therapeutic platform technologies, several engineered protein scaffolds are in early clinical development and offer differences and some potential advantages over antibodies.

  13. Microrheology of polyethylene oxide using DWS and single scattering

    NASA Astrophysics Data System (ADS)

    Dasgupta, B. R.; Crocker, J. C.; Tee, S. Y.; Weitz, D. A.

    2000-03-01

    We have measured the microrheological properties of polyethylene oxide, a flexible polymer from particle motions obtained through diffusing wave spectroscopy (DWS) and single scattering. We used two different molecular weights of PEO, 200K and 900K and studied the rheology of these polymers at concentrations above c*. The results obtained from these techniques compare well, within experimental errors, to data obtained from conventional bulk measurements. Using DWS, we can probe the rheology of the system at larger frequency regimes. Since we use only thermal energies of the embedded beads the material is subjected to very small strains as compared to bulk measurements. Other advantages of using this method are that one can measure visco-elastic behavior on a very small amount ( 2ml) and multiply scattering samples. Single scattering on the other hand allows us to probe at larger time scales than DWS and combining both these methods gives us a comprehensive overlap with the conventional rheological data. The work was supported by NSF grants DMR 9971432 and DMR 9704300.

  14. Confined crystallization in compatibilized Polyamide 6/High Density Polyethylene blends

    NASA Astrophysics Data System (ADS)

    Ceccia, Simona; Argoud, Alexandra; Trouillet-Fonti, Lise; Long, Didier R.; Sotta, Paul

    2012-02-01

    Blending polymers can be considered the easiest way to obtain new materials with tuned properties thanks to the possibility to control blend morphologies. The blend characteristics depend on the properties of each component, on composition and on morphologies developed during polymers processing. In case of semi-crystalline blended polymers, mechanical performances are closely related to the crystalline morphology. Therefore, it is essential that crystallinity is maintained after blending in order to keep or enhance the properties. This may be a challenge when the blends exhibit multiphase morphologies with sub-micrometer domain sizes. In this work, we study the crystallization behavior of compatibilized Polyamide 6/High Density Polyethylene (PA6/PE) blends by means of the Differential Scanning Calorimetry technique. Blends with various morphologies (dispersed, stretched dispersed, fibrillar and co-continuous) are obtained by reactive extrusion and varying blend composition and processing parameters. Blend composition and morphology turn out to greatly affect the bulk crystallization temperatures of both PA6 and PE. When the polymer is confined in domains of a few micrometers the crystallization temperature peak shifts to lower temperatures. Thus, the smaller the domain size the lower the crystallization temperature in case of dispersed morphologies. Moreover, in multi-scale morphologies showing polymer droplets in the nanometer range, fractionated crystallization (multiple crystallization peaks) is observed.

  15. Diffusion in Binary Polyethylene Blends: Role of Constraint Release

    NASA Astrophysics Data System (ADS)

    von Meerwall, E. D.; Dirama, N.; Mattice, W. L.

    2004-03-01

    In support of our Monte-Carlo simulations, we have used the proton pulsed-gradient NMR method to augment our earlier diffusion measurements in n-alkane and polyethylene (PE) melts and blends with three series of blends at T = 150 deg. C across the full concentration (c) range. Blends were based on M = 33k PE and contained either n-C50 alkane, M = 1.8k PE, or M = 6.7k PE. The results again agree with our theoretical synthesis(1) involving a smooth transition from Rouse to reptational behavior including constraint release (CR) and free-volume host effects which depend on T, M, and c. Tube dilation is assumed contained in the CR mechanism; contour length fluctuations are not considered to affect center-of-mass diffusion. The generalized CR term not only reproduces the c- and M-dependences of the self-diffusion of both species in fully entangled blends, but also supplants entanglement dilution in blends of PE with (unentangled) n-C50 and n-C12 (our earlier work), thus shifting from spatial to temporal constraint at all M in homologous blends. (1) E. von Meerwall, et al., J. Chem. Phys. 111, 750 (1999); E. von Meerwall, et al., Polymer Prepr. 44, 287 (2003).

  16. Remnant Repair-enhanced Polyethylene Terepthalate Artificial Ligament Graft Ligamentization.

    PubMed

    Li, H; Chen, J; Chen, S

    2015-11-01

    The aim of this study was to investigate whether augmented remnant repair could enhance polyethylene terepthalate (PET) artificial ligament graft ligamentization. 12 female goats underwent ACL reconstruction with PET artificial ligament graft in the right knees. Right knees in 6 goats were reconstructed with augmented remnant repair (Remnant group), whereas the other 6 goats had no augmented remnant repair comprised the Control group. 3 goats in each group were randomly sacrificed at 6 months and 12 months respectively after surgery. The intra-articular parts of the reconstructed grafts were harvested for histological evaluation. Well-vascularized tissue ingrowth within the artificial ligament was observed in the remnant group at 12 months postoperatively. Collagen-I content of graft was significantly higher in the Remnant group than in the Control group at each time point (p<0.05). The relative expression of collagen-III positive area of the remnant-preserved group was significantly higher than that of the Control group at 12 months (p=0.005). The vascular endothelial growth factor (VEGF)-positive or CD31-positive area in the graft appeared higher in the Remnant group compared with the Control group at 6 months. Remnant repair enhanced the revascularization and remodeling of the PET artificial ligament in ACL reconstruction. PMID:26258818

  17. Microfluidic Valves Made From Polymerized Polyethylene Glycol Diacrylate

    PubMed Central

    Rogers, Chad I.; Oxborrow, Joseph B.; Anderson, Ryan R.; Tsai, Long-Fang; Nordin, Gregory P.; Woolley, Adam T.

    2013-01-01

    Pneumatically actuated, non-elastomeric membrane valves fabricated from polymerized polyethylene glycol diacrylate (poly-PEGDA) have been characterized for temporal response, valve closure, and long-term durability. A ~100 ms valve opening time and a ~20 ms closure time offer valve operation as fast as 8 Hz with potential for further improvement. Comparison of circular and rectangular valve geometries indicates that the surface area for membrane interaction in the valve region is important for valve performance. After initial fabrication, the fluid pressure required to open a closed circular valve is ~50 kPa higher than the control pressure holding the valve closed. However, after ~1000 actuations to reconfigure polymer chains and increase elasticity in the membrane, the fluid pressure required to open a valve becomes the same as the control pressure holding the valve closed. After these initial conditioning actuations, poly-PEGDA valves show considerable robustness with no change in effective operation after 115,000 actuations. Such valves constructed from non-adsorptive poly-PEGDA could also find use as pumps, for application in small volume assays interfaced with biosensors or impedance detection, for example. PMID:24357897

  18. Evaluation of hybrid rubber-polyethylene industrial battery separators

    NASA Astrophysics Data System (ADS)

    Wimberly, Rick; Miller, Jamie; Brilmyer, George

    Antimonial lead alloys continue to play a key role in the overall success of the lead-acid battery in deep cycle applications. In markets such as motive power and golf car, these alloys have long been known to assist the performance of the positive plate by promoting a healthy, grid-active material interface. Antimony, on the other hand, is a well-established poison to the negative plate and ultimately leads to gassing, water-loss and cell failure. Reports in the literature indicate that specific battery separator materials may be used to delay the onset of gassing by suppressing the effects of antimony. Literature findings also suggest that the suppression effect may be due to a combination of the chemical make-up of the separator and its physical attributes. It is the intention of this paper to introduce a novel method for evaluating battery separator materials in terms of their ability to suppress the deleterious effects of antimony. Results presented here indicate that the chemical composition of the separator is a controlling factor in suppressing the influence of antimony in the lead-acid battery. Initial information on the characteristics of a new hybrid rubber-polyethylene battery separator is also presented.

  19. Mesophases in polyethylene, polypropylene, and poly(1-butene)

    SciTech Connect

    Androsch, Rene J; Di Lorenzo, Maria; Schick, Christoph; Wunderlich, Bernhard {nmn}

    2010-01-01

    This paper contains new views about the amorphous and partially ordered phases of the three polymers listed in the title. The discussion is based on information on structure, thermodynamic stability, and large-amplitude molecular motion. Polyethylene is the basic backbone of all alkene polymers, and the other two are the first members of the vinyl polymers which have stereospecifically placed alkyl side chains. Their multiphase structures consist of metastable crystals, mesophases, and surrounding rigid and mobile amorphous fractions. All these phases have sizes ranging from micrometer dimensions down to nanometers. Besides the phase structures, information about the molecular coupling between the phases must be considered. Depending on temperature, the polymer phases can vary from solid (rigid) to liquid (mobile). New knowledge is also gained by cross-comparison of the title polymers. The experimental information was gained from (a) various forms of slow, fast, and temperature-modulated thermal analysis to identify equilibrium and non-equilibrium states, (b) measurement of structure and morphology at various length scales, and (c) tracing of the large-amplitude molecular motion, the kinetics of order/disorder changes, and the liquid/solid transitions (glass transitions). It is shown that much more needs to be known about the various phases and their coupling to characterize a given polymer and to fine-tune its properties for a given application.

  20. High Speed Deformation of the Poly(Ethylene Terephthalate)

    NASA Astrophysics Data System (ADS)

    Ladouce, L.; Perez, J.; Vassoille, R.

    1996-01-01

    Mechanical behaviour of amorphous and semi-crystalline polyethylene terephthalate films is studied over five decades of strain rates, at temperatures below and above the glass transition. The data were obtained by combining measurements from conventional Instron machine with data from a high-speed tensile machine. The activation parameters are determined and compared with the activation process of the ? relaxation. Different modes of failure have been identified and the occurrence of an intermediate mode between ductile and brittle failure is shown. The brittle-ductile transition is estimated for each testing conditions and compared to the adiabatic-isothermal transition. Le comportement mécanique du Poly(éthylène téréphthalate) amorphe et semi-cristallin est étudié sur plus de cinq ordres de grandeurs de vitesse de déformation, de part et d'autre de la température de transition vitreuse. Les mesures expérimentales sont réalisées à l'aide d'une machine de traction Instron, pour les faibles vitesses de déformation, et d'une machine servo-hydraulique pour les grandes vitesses. Les paramètres d'activation sont déterminés et comparés à ceux de la relaxation secondaire basse température ?. Différents modes de rupture sont identifiés; entre une rupture typiquement ductile et une rupture fragile, un mode de rupture intermédiaire est mis en évidence. La transition ductile-fragile est estimée pour chaque condition d'essai, et comparée à la transition isotherme-adiabatique.

  1. A New Polyethylene Scattering Law Determined Using Inelastic Neutron Scattering

    SciTech Connect

    Lavelle, Christopher M; Liu, C; Stone, Matthew B

    2013-01-01

    Monte Carlo neutron transport codes such as MCNP rely on accurate data for nuclear physics cross-sections to produce accurate results. At low energy, this takes the form of scattering laws based on the dynamic structure factor, S (Q, E). High density polyethylene (HDPE) is frequently employed as a neutron moderator at both high and low temperatures, however the only cross-sections available are for T =300 K, and the evaluation has not been updated in quite some time. In this paper we describe inelastic neutron scattering measurements on HDPE at 5 and 300 K which are used to improve the scattering law for HDPE. We describe the experimental methods, review some of the past HDPE scattering laws, and compare computations using these models to the measured S (Q, E). The total cross-section is compared to available data, and the treatment of the carbon secondary scatterer as a free gas is assessed. We also discuss the use of the measurement itself as a scattering law via the 1 phonon approximation. We show that a scattering law computed using a more detailed model for the Generalized Density of States (GDOS) compares more favorably to this experiment, suggesting that inelastic neutron scattering can play an important role in both the development and validation of new scattering laws for Monte Carlo work.

  2. Experimental characterization of triboelectric charging of polyethylene powders

    NASA Astrophysics Data System (ADS)

    Janta?, Simon; Konopka, Ladislav; Kosek, Juraj

    2015-10-01

    Triboelectric charging causes serious problems in the industrial processing of powders. We focus on the charging of polyethylene (PE) powder particles, whose agglomeration can cause serious economic problems in PE production in fluidized-bed reactors. The ‘cascade method’ apparatus, i.e., a slide followed by the Faraday's pail, was utilized to observe the particle-wall charging of PE particles in friction contact with various materials (glass, aluminium, PE) and allowed us to characterize the charging dynamics. Our results indicate that the evolution of the charge on the particles follows a saturation curve, where the saturated state is represented by maximum (outcome) charge. Such a trend can be conveniently fitted by a function representing the first-order dynamics. We determine the dependency of charging dynamics on various factors, e.g., the humidity, the slide surface roughness and the slide material. Our measurements imply that air humidity influences the charging process substantially more than the choice of the slide material. Moreover, we observe significant charging even in the case of the same materials being in contact. The work contributes to a better understanding of tribocharging and the estimation of charging-related parameters provides the input for the modelling of this complex process.

  3. Delamination toughness of ultra high molecular weight polyethylene (UHMWPE) composites

    NASA Astrophysics Data System (ADS)

    Porras, A.; Tellez, J.; Casas-Rodriguez, J. P.

    2012-08-01

    Ultra high molecular weight polyethylene (UHMWPE) fibre reinforced composites are an important group of material for armours solutions, where their unique combination of properties could be utilized. A commonly observed failure mode in this kind of unidirectional laminated composites under impact ballistic is delamination between the composite layers. In the present study, an investigation on the delamination toughness behaviour exhibited by UHMWPE composites laminated was made. The interlaminar Mode II critical strain energy release rates of (UHMWPE) fibre reinforced composites were characterized using the End Notch Flexural (ENF) test. Critical strain energy release rate was obtained from the load - deflection test data using the beam theory expression. It was found that the energy release rate of the composite exhibited a very low value of around 60J/m2 using a moulding pressure of approximately 1200 psi. In order to analyse the delamination resistance of composite, the effects of changing the manufacture process variables and the use of a thermoplastic adhesive film in the composites were investigated. The composite laminates were produced by hot compressing moulding using a film-stacking procedure. It was found that the damage resistance of the UHMWPE composite was influenced by the manufacture method, which affects the Mode II interlaminar fracture toughness and the ballistic response of composites.

  4. Incipient and Progressive Damage in Polyethylene Under Extreme Tensile Conditions

    SciTech Connect

    Furmanski, Jevan; Brown, Eric; Trujillo, Carl P.; Martinez, Daniel Tito; Gray, George T. III

    2012-06-07

    The Dynamic-Tensile-Extrusion (Dyn-Ten-Ext) test was developed at LANL by Gray and coworkers to probe the tensile response of materials at large strains (>1) and high strain-rates (>1000/s) by firing projectiles through a conical die at 300-700 m/s. This technique has recently been applied to various polymers, such as the fluoropolymers PTFE (Teflon) and the chemically similar PCTFE, which respectively exhibited catastrophic fragmentation and distributed dynamic necking. This work details investigations of the Dyn-Ten-Ext response of high density polyethylene, both to failure and sub-critical conditions. At large extrusion ratios ({approx}7.4) and high velocities, such as those previously employed, HDPE catastrophically fragmented in a craze-like manner in the extruded jet. At more modest extrusion ratios and high velocities the specimen extruded a stable jet that ruptured cleanly, and at lower velocities was recovered intact after sustaining substantial internal damage. Thermomechanical finite element simulations showed that the damage corresponded to a locus of shear stress in the presence of hydrostatic tension. X-ray computed tomography corroborated the prediction of a shear damage mechanism by finding the region of partially damaged material to consist of macroscopic shear-mode cracks nearly aligned with the extrusion axis, originating from the location of damage inception.

  5. Unraveling the luminescence signatures of chemical defects in polyethylene

    NASA Astrophysics Data System (ADS)

    Chen, Lihua; Tran, Huan Doan; Wang, Chenchen; Ramprasad, Rampi

    2015-09-01

    Chemical defects in polyethylene (PE) can deleteriously downgrade its electrical properties and performance. Although these defects usually leave spectroscopic signatures in terms of characteristic luminescence peaks, it is nontrivial to make unambiguous assignments of the peaks to specific defect types. In this work, we go beyond traditional density functional theory calculations to determine intra-defect state transition and charge recombination process derived emission and absorption energies in PE. By calculating the total energy differences of the neutral defect at excited and ground states, the emission energies from intra-defect state transition are obtained, reasonably explaining the photoluminescence peaks in PE. In order to study the luminescence emitted in charge recombination processes, we characterize PE defect levels in terms of thermodynamic and optical charge transition levels that involve total energy calculations of neutral and charged defects. Calculations are performed at several levels of theory including those involving (semi)local and hybrid electron exchange-correlation functionals, and many-body perturbation theory. With these critical elements, the emission energies are computed and further used to clarify and confirm the origins of the observed electroluminescence and thermoluminescence peaks.

  6. Unraveling the luminescence signatures of chemical defects in polyethylene.

    PubMed

    Chen, Lihua; Tran, Huan Doan; Wang, Chenchen; Ramprasad, Rampi

    2015-09-28

    Chemical defects in polyethylene (PE) can deleteriously downgrade its electrical properties and performance. Although these defects usually leave spectroscopic signatures in terms of characteristic luminescence peaks, it is nontrivial to make unambiguous assignments of the peaks to specific defect types. In this work, we go beyond traditional density functional theory calculations to determine intra-defect state transition and charge recombination process derived emission and absorption energies in PE. By calculating the total energy differences of the neutral defect at excited and ground states, the emission energies from intra-defect state transition are obtained, reasonably explaining the photoluminescence peaks in PE. In order to study the luminescence emitted in charge recombination processes, we characterize PE defect levels in terms of thermodynamic and optical charge transition levels that involve total energy calculations of neutral and charged defects. Calculations are performed at several levels of theory including those involving (semi)local and hybrid electron exchange-correlation functionals, and many-body perturbation theory. With these critical elements, the emission energies are computed and further used to clarify and confirm the origins of the observed electroluminescence and thermoluminescence peaks. PMID:26429041

  7. Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use

    PubMed Central

    Shin, Chan Young; Kim, Kyu-Bong

    2015-01-01

    Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient. PMID:26191379

  8. An Evaluation of Polycyclic Aromatic Hydrocarbon Uptake into Polyethylene Samplers

    NASA Astrophysics Data System (ADS)

    Martynowych, D. J.; McDonough, C.; Lohmann, R.

    2013-12-01

    Polyethylene passive samplers (PEs) are simple reliable tools that have been widely used in the detection of hydrophobic organic compounds. Thick (>200?m or greater) PEs have important applications to specific sampling scenarios including biological assays, deployment on ships and aircraft (towing) and long term sampling, however little is known about their uptake kinetics. This study aimed to develop an accurate understanding of the uptake kinetics of these thick PEs. PE passive samplers of equal surface area, but differing thicknesses were co-deployed in the surface water and air of lower Narragansett Bay in 2013 to characterize differences in their uptake of polycyclic aromatic hydrocarbons (PAHs). PE samplers of approximately 50, 800, and 1600?m thicknesses were analyzed for 38 parent and alkylated PAHs, with replicate sampler reproducibility mostly within 25%. A number of smaller PAHs (typically those with a molecular weight less than 180) analyzed over a 4 week deployment equilibrated, while the larger molecules remained in the linear or curve linear uptake stages. Results from a second, 24 week deployment of 800?m and 1600?m samplers in surface waters suggest that all 38 compounds studied remained in the linear uptake stage. The PE-weight normalized concentration ratio of 1600?m to 800?m sampler fell below 1 for all analytes, implying equilibrium had not been established.

  9. Fabrication of Protein Dot Arrays via Particle Lithography

    PubMed Central

    Taylor, Zachary R.; Patel, Krupa; Spain, Travis; Keay, Joel C.; Jernigen, Jeremy D.; Sanchez, Ernest S.; Grady, Brian P.; Johnson, Matthew B.; Schmidtke, David W.

    2009-01-01

    The ability to pattern a surface with proteins on both the nanometer and micrometer scale has attracted considerable interest due to its applications in the fields of biomaterials, biosensors, and cell adhesion. Here we describe a simple particle lithography technique to fabricate substrates with hexagonally patterned dots of protein surrounded by a protein-repellant layer of poly(ethylene glycol) (PEG). Using this bottom-up approach, dot arrays of three different proteins (fibrinogen, P-selectin, and human serum albumin) were fabricated. The size of the protein dots (450 nm - 1.1 ?m) was independent of the protein immobilized, but could be varied by changing the size of the latex spheres (diameter = 2 - 10 ?m) utilized in assembling the lithographic bead monolayer. These results suggest that this technique can be extended to other biomolecules and will be useful in applications where arrays of protein dots are desired. PMID:19670836

  10. Controlled Activation of Protein Rotational Dynamics Using Smart Hydrogel Tethering

    SciTech Connect

    Beech, Brenda M.; Xiong, Yijia; Boschek, Curt B.; Baird, Cheryl L.; Bigelow, Diana J.; Mcateer, Kathleen; Squier, Thomas C.

    2014-09-05

    Stimulus-responsive hydrogel materials that stabilize and control protein dynamics have the potential to enable a range of applications to take advantage of the inherent specificity and catalytic efficiencies of proteins. Here we describe the modular construction of a hydrogel using an engineered calmodulin (CaM) within a polyethylene glycol (PEG) matrix that involves the reversible tethering of proteins through an engineered CaM-binding sequence. For these measurements, maltose binding protein (MBP) was isotopically labeled with [13C] and [15N], permitting dynamic structural measurements using TROSY-HSQC NMR spectroscopy. Upon initial formation of hydrogels protein dynamics are suppressed, with concomitant increases in protein stability. Relaxation of the hydrogel matrix following transient heating results in the activation of protein dynamics and restoration of substrate-induced large-amplitude domain motions necessary for substrate binding.

  11. Local effect of IL-4 delivery on polyethylene particle induced osteolysis in the murine calvarium.

    PubMed

    Rao, Allison J; Nich, Christophe; Dhulipala, Lakshmi S; Gibon, Emmanuel; Valladares, Roberto; Zwingenberger, Stefan; Smith, R Lane; Goodman, Stuart B

    2013-07-01

    Wear particles generated with use of total joint replacements incite a chronic macrophage-mediated inflammatory reaction, which leads to implant failure. Macrophage activation may be polarized into two states, with an M1 proinflammatory state dominating an alternatively activated M2 anti-inflammatory state. We hypothesized that IL-4, an activator of M2 macrophages, could modulate polyethylene (PE) particle-induced osteolysis in an experimental murine model. Four animal groups included (a) calvarial saline injection with harvest at 14 days (b) single calvarial injection of PE particles subcutaneously (SC) without IL-4 (c) PE particles placed as in (b), then IL-4 given SC for 14 consecutive days and (d) PE particles as in (b) then IL-4 beginning 7 days after particle injection for 7 days. The calvarial bone volume to total tissue volume was measured using microCT and histomorphometry. Calvaria were cultured for 24 h to assess release of RANKL, OPG, TNF-?, and IL-1ra and isolation and identification of M1 and M2 specific proteins. MicroCT and histomorphometric analysis showed that bone loss was significantly decreased following IL-4 administration to PE treated calvaria for both 7 and 14 days. Western blot analysis showed an increased M1/M2 ratio in the PE treated calvaria, which decreased with addition of IL-4. Cytokine analysis showed that the RANKL/OPG ratio and TNF-?/IL-1ra ratio decreased in PE-treated calvaria following IL-4 addition for 14 days. IL-4 delivery mitigated PE particle-induced osteolysis through macrophage polarization. Modulation of macrophage polarization is a potential treatment strategy for wear particle induced periprosthetic osteolysis. PMID:23225668

  12. Biodegradable pH-Sensitive Poly(ethylene glycol) Nanocarriers for Allergen Encapsulation and Controlled Release.

    PubMed

    Pohlit, Hannah; Bellinghausen, Iris; Schömer, Martina; Heydenreich, Bärbel; Saloga, Joachim; Frey, Holger

    2015-10-12

    In the last decades, the number of allergic patients has increased dramatically. Allergen-specific immunotherapy (SIT) is the only available cause-oriented therapy so far. SIT reduces the allergic symptoms, but also exhibits some disadvantages; that is, it is a long-lasting procedure and severe side effects like anaphylactic shock can occur. In this work, we introduce a method to encapsulate allergens into nanoparticles to avoid severe side effects during SIT. Degradable nanocarriers combine the advantage of providing a physical barrier between the encapsulated cargo and the biological environment as well as responding to certain local stimuli (like pH) to release their cargo. This work introduces a facile strategy for the synthesis of acid-labile poly(ethylene glycol) (PEG)-macromonomers that degrade at pH 5 (physiological pH inside the endolysosome) and can be used for nanocarrier synthesis. The difunctional, water-soluble PEG dimethacrylate (PEG-acetal-DMA) macromonomers with cleavable acetal units were analyzed with (1)H NMR, SEC, and MALDI-ToF-MS. Both the allergen and the macromonomers were entrapped inside liposomes as templates, which were produced by dual centrifugation (DAC). Radical polymerization of the methacrylate units inside the liposomes generated allergen-loaded PEG nanocarriers. In vitro studies demonstrated that dendritic cells (DCs) internalize the protein-loaded, nontoxic PEG-nanocarriers. Furthermore, we demonstrate by cellular antigen stimulation tests that the nanocarriers effectively shield the allergen cargo from detection by immunoglobulins on the surface of basophilic leucocytes. Uptake of nanocarriers into DCs does not lead to cell maturation; however, the internalized allergen was capable to induce T cell immune responses. PMID:26324124

  13. Preparation of poly(ethylene glycol)/polylactide hybrid fibrous scaffolds for bone tissue engineering

    PubMed Central

    Ni, PeiYan; Fu, ShaoZhi; Fan, Min; Guo, Gang; Shi, Shuai; Peng, JinRong; Luo, Feng; Qian, ZhiYong

    2011-01-01

    Polylactide (PLA) electrospun fibers have been reported as a scaffold for bone tissue engineering application, however, the great hydrophobicity limits its broad application. In this study, the hybrid amphiphilic poly(ethylene glycol) (PEG)/hydrophobic PLA fibrous scaffolds exhibited improved morphology with regular and continuous fibers compared to corresponding blank PLA fiber mats. The prepared PEG/PLA fibrous scaffolds favored mesenchymal stem cell (MSC) attachment and proliferation by providing an interconnected porous extracellular environment. Meanwhile, MSCs can penetrate into the fibrous scaffold through the interstitial pores and integrate well with the surrounding fibers, which is very important for favorable application in tissue engineering. More importantly, the electrospun hybrid PEG/PLA fibrous scaffolds can enhance MSCs to differentiate into bone-associated cells by comprehensively evaluating the representative markers of the osteogenic procedure with messenger ribonucleic acid quantitation and protein analysis. MSCs on the PEG/PLA fibrous scaffolds presented better differentiation potential with higher messenger ribonucleic acid expression of the earliest osteogenic marker Cbfa-1 and mid-stage osteogenic marker Col I. The significantly higher alkaline phosphatase activity of the PEG/PLA fibrous scaffolds indicated that these can enhance the differentiation of MSCs into osteoblast-like cells. Furthermore, the higher messenger ribonucleic acid level of the late osteogenic differentiation markers OCN (osteocalcin) and OPN (osteopontin), accompanied by the positive Alizarin red S staining, showed better maturation of osteogenic induction on the PEG/PLA fibrous scaffolds at the mineralization stage of differentiation. After transplantation into the thigh muscle pouches of rats, and evaluating the inflammatory cells surrounding the scaffolds and the physiological characteristics of the surrounding tissues, the PEG/PLA scaffolds presented good biocompatibility. Based on the good cellular response and excellent osteogenic potential in vitro, as well as the biocompatibility with the surrounding tissues in vivo, the electrospun PEG/PLA fibrous scaffolds could be one of the most promising candidates in bone tissue engineering. PMID:22163160

  14. Histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits

    PubMed Central

    Yu, Shao-Bin; Yang, Rong-Hua; Zuo, Zhong-Nan; Dong, Qi-Rong

    2014-01-01

    Polyethylene terephthalate LARS ligament were the remnant of LARS ligament used for repairing posterior cruciate ligament obtained from operation. We want to study histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits. Therefore, we replaced the original ACL with polyethylene terephthalate LARS ligament which was covering with the remnant of ACL in 9 rabbits (L-LARS group), while just only polyethylene terephthalate LARS ligament were transplanted in 3 rabbits (LARS group) with the remnant of ACL. Compared with group LARS, inflammatory cell reaction and foreign body reaction were more significant in group L-LARS. Moreover, electron microscopy investigation showed the tissue near LARS fibers was highly cellular with a matrix of thin collagen fibrils (50-100 nm) in group L-LARS. These above findings suggest the polyethylene terephthalate LARS ligament possess the high biocompatibility, which contributes to the polyethylene terephthalate LARS covered with recipient connective tissues. PMID:25356104

  15. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Boric acid (H3BO3), mixed esters with polyethylene...Chemical Substances § 721.1729 Boric acid (H3 BO3 ), mixed esters with...chemical substance identified as boric acid (H3 BO3 ), mixed...

  16. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Boric acid (H3BO3), mixed esters with polyethylene...Chemical Substances § 721.1729 Boric acid (H3 BO3 ), mixed esters with...chemical substance identified as boric acid (H3 BO3 ), mixed...

  17. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Boric acid (H3BO3), mixed esters with polyethylene...Chemical Substances § 721.1729 Boric acid (H3 BO3 ), mixed esters with...chemical substance identified as boric acid (H3 BO3 ), mixed...

  18. Gene transfection mediated by polyethyleneimine-polyethylene glycol nanocarrier prevents cisplatin-induced spiral ganglion cell damage

    PubMed Central

    Chen, Guan-gui; Mao, Min; Qiu, Li-zi; Liu, Qi-ming

    2015-01-01

    Polyethyleneimine-polyethylene glycol (PEI-PEG), a novel nanocarrier, has been used for transfection and gene therapy in a variety of cells. In our previous study, we successfully carried out PEI-PEG-mediated gene transfer in spiral ganglion cells. It remains unclear whether PEI-PEG could be used for gene therapy with X-linked inhibitor of apoptosis protein (XIAP) in the inner ear. In the present study, we performed PEI-PEG-mediated XIAP gene transfection in the cochlea of Sprague-Dawley rats, via scala tympani fenestration, before daily cisplatin injections. Auditory brainstem reflex tests demonstrated the protective effects of XIAP gene therapy on auditory function. Immunohistochemical staining revealed XIAP protein expression in the cytoplasm of cells in the spiral ganglion, the organ of Corti and the stria vascularis. Reverse transcription-PCR detected high levels of XIAP mRNA expression in the cochlea. The present findings suggest that PEI-PEG nanocarrier-mediated XIAP gene transfection results in XIAP expression in the cochlea, prevents damage to cochlear spiral ganglion cells, and protects hearing. PMID:25878591

  19. Parameterization of an interfacial force field for accurate representation of peptide adsorption free energy on high-density polyethylene.

    PubMed

    Abramyan, Tigran M; Snyder, James A; Yancey, Jeremy A; Thyparambil, Aby A; Wei, Yang; Stuart, Steven J; Latour, Robert A

    2015-01-01

    Interfacial force field (IFF) parameters for use with the CHARMM force field have been developed for interactions between peptides and high-density polyethylene (HDPE). Parameterization of the IFF was performed to achieve agreement between experimental and calculated adsorption free energies of small TGTG-X-GTGT host-guest peptides (T = threonine, G = glycine, and X = variable amino-acid residue) on HDPE, with ±0.5?kcal/mol agreement. This IFF parameter set consists of tuned nonbonded parameters (i.e., partial charges and Lennard-Jones parameters) for use with an in-house-modified CHARMM molecular dynamic program that enables the use of an independent set of force field parameters to control molecular behavior at a solid-liquid interface. The R correlation coefficient between the simulated and experimental peptide adsorption free energies increased from 0.00 for the standard CHARMM force field parameters to 0.88 for the tuned IFF parameters. Subsequent studies are planned to apply the tuned IFF parameter set for the simulation of protein adsorption behavior on an HDPE surface for comparison with experimental values of adsorbed protein orientation and conformation. PMID:25818122

  20. Physicochemical and biomechanical examination of surfaces of retrieved polyethylene heads from total hip prostheses with rotating polyethylene head system.

    PubMed

    Katayama, K; Maezawa, H; Uesato, N; Sasada, T

    2001-01-01

    In order to assess whether hydrodynamic lubrication occurs in total hip prostheses with a rotating polyethylene (PE) head system (R-THP), several physicochemical, morphological, and biomechanical tests were carried out. R-THPs have been used in more than 1000 patients since 1970, and 12 PE heads, retrieved from 10 patients after an average of 24.5 years since total hip arthroplasty (THA), were employed for the tests. The weight-bearing area of the PE surface was light yellow in color and considerably oxidized, but no wear scars were observed. In the non-weight-bearing area, in contrast, discoloration and oxidation were hard to detect. The weight-bearing surface of the PE head became smoother with time after THA, and the friction coefficient did not differ significantly from that of an unused PE head. The radial clearance between head and socket decreased at a temperature of 17 degrees C, which is equivalent to the difference between room temperature and the temperature of the human body. Scanning electron microscopy showed a fine undulating pattern, which suggested that hydrodynamic lubrication could occur in the rotating PE head system. PMID:11793172

  1. Near infrared light-responsive and injectable supramolecular hydrogels for on-demand drug delivery.

    PubMed

    Wang, Xinyu; Wang, Changping; Zhang, Qiang; Cheng, Yiyun

    2016-01-01

    A near infrared (NIR) light-responsive supramolecular hydrogel consisting of ?-cyclodextrin and poly(ethylene glycol)-modified dendrimer-encapsulated platinum nanoparticles was developed. Upon NIR irradiation, this hydrogel underwent a photothermo-sensitive degradation to release the entrapped therapeutic agents in an on-demand and dose-tunable fashion. PMID:26588349

  2. Interaction between water and poly(vinylpyrrolidone) containing polyethylene glycol.

    PubMed

    Hamaura, T; Newton, J M

    1999-11-01

    Information on the interaction between water and polymers is indispensable for manufacturing solid dispersion of a drug by hot-melt extrusion because this interaction affects various properties of the water-polymer mixtures, such as their viscoelastic properties. In this study, poly(vinylpyrrolidone) K30 (PVP) containing 0%, 10%, and 20% poly(ethylene glycol) 400 (PEG) was used as model amorphous polymers. The interaction of water with these polymers was assessed by the evaluation of the glass transition temperature (Tg), the point on the isotherm corresponding to the weight of sorbed water required to form a complete monolayer on the solid surface (apparent Wm), and the maximal amount of nonfreezing water, which were measured by differential scanning calorimetry and water sorption isotherms. In all of the systems with a water content below a certain water fraction (0.1 for PVP, 0.12 for PVP-PEG 10%, and 0.16 for PVP-PEG 20%), the Tg values were successfully predicted using theoretical equations, whereas the experimental Tg values were higher than predicted for those with a water content above these water fraction levels. In addition, these values of water fraction are similar to the apparent W(m) values determined using the Guggenheim-Anderson-DeBoer (GAB) equation (0.110, 0.117, and 0.147 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively). Nonfreezing water is detected above 0.47, 0.49, and 0.51 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively. Miscibility between water and PVP or PVP-PEG seems to change according to the water content in the system. All parameters increase with the concentration of PEG in the sample. This may be explained by the fact that PEG has a larger number of polymer repeating units, which may therefore interact with water more than PVP. PMID:10564074

  3. A course-grained model for polyethylene glycol polymer

    SciTech Connect

    Nicholson, Don M; Wang, Qifei; Keffer, David J

    2011-01-01

    A coarse-grained (CG) model of polyethylene glycol (PEG) was developed and implemented in CG molecular dynamics (MD) simulations of PEG chains with degree of polymerization (DP) 20 and 40. In the model, two repeat units of PEG are grouped as one CG bead. Atomistic MD simulation of PEG chains with DP = 20 was first conducted to obtain the bonded structural probability distribution functions (PDFs) and nonbonded pair correlation function (PCF) of the CG beads. The bonded CG potentials are obtained by simple inversion of the corresponding PDFs. The CG nonbonded potential is parameterized to the PCF using both an inversion procedure based on the Ornstein-Zernike equation with the Percus-Yevick approximation (OZPY{sup -1}) and a combination of OZPY{sup -1} with the iterative Boltzmann inversion (IBI) method (OZPY{sup -1}+IBI). As a simple one step method, the OZPY{sup -1} method possesses an advantage in computational efficiency. Using the potential from OZPY{sup -1} as an initial guess, the IBI method shows fast convergence. The coarse-grained molecular dynamics (CGMD) simulations of PEG chains with DP = 20 using potentials from both methods satisfactorily reproduce the structural properties from atomistic MD simulation of the same systems. The OZPY{sup -1}+IBI method yields better agreement than the OZPY{sup -1} method alone. The new CG model and CG potentials from OZPY{sup -1}+IBI method was further tested through CGMD simulation of PEG with DP = 40 system. No significant changes are observed in the comparison of PCFs from CGMD simulations of PEG with DP = 20 and 40 systems indicating that the potential is independent of chain length.

  4. Various-sourced pectin and polyethylene oxide electrospun fibers.

    PubMed

    Rockwell, Pamela L; Kiechel, Marjorie A; Atchison, Jennifer S; Toth, Laura J; Schauer, Caroline L

    2014-07-17

    Pectin, a naturally occurring and biorenewable polysaccharide, is derived from plant cell wall tissue and used in applications ranging from food processing to biomedical engineering. Due to extraction methods and source variation, there is currently no consensus in literature as to the exact structure of pectin. Here, we have studied key material properties of electrospun pectin blends with polyethylene oxide (PEO) (1:1, v/v) in order to demonstrate the fabrication of a fibrous and less toxic material system, as well as to understand the effects of source variability on the resulting fibrous mats. The bulk pectin degree of esterification (DE) estimated using FTIR (bulk apple pomace (AP)=28%, bulk citrus peel (CP)=86% and bulk sugar beet pulp (SBP)=91%) was shown to inversely correlate with electrospun fiber crystallinity determined using XRD (PEO-AP=37%, PEO-CP=28% and PEO-SBP=23%). This in turn affected the trend observed for the mean fiber diameter (n=50) (PEO-AP=124 ± 26 nm, PEO-CP=493 ± 254 nm and PEO-SBP=581 ± 178 nm) and elastic tensile moduli (1.6 ± 0.2 MPa, 4.37 ± 0.64 MPa and 2.49 ± 1.46 MPa, respectively) of the fibrous mats. Electrospun fibers containing bulk AP had the lowest DE, highest crystallinity, smallest mean fiber diameter, and lowest tensile modulus compared to either the bulk CP or bulk SBP. Bound water in PEO-CP fiber and bulk pectin impurities in PEO-SPB were observed to influence fiber branching and mean diameter distributions, which in turn influenced the fiber tensile properties. These results indicate that pectin, when blended with PEO in water, produces submicron fibrous mats with pectin influencing the blend fiber properties. Moreover, the source of pectin is an important variable in creating electrospun blend fibrous mats with desired material properties. PMID:24702925

  5. Permeation Resistance of Chlorinated Polyethylene Against Hydrazine Fuels

    NASA Technical Reports Server (NTRS)

    Waller, J. M.; Williams, J. H.

    1999-01-01

    The permeation resistance of chlorinated polyethylene (CPE) used in chemical protective clothing against the aerospace fuels hydrazine, monomethylhydrazine (MMH), and uns-dimethylhydrazine (UDMH) was determined by measuring breakthrough times and time-averaged vapor transmission rates using an ASTM F 739 permeation cell. Two exposure scenarios were simulated: a 2 hour (h) fuel vapor exposure, and a liquid fuel "splash" followed by a 2 h vapor exposure. To simulate internal suit pressure during operation, a positive differential pressure of 0.3 in. water (75 Pa) on the collection side of the permeation apparatus was used. Breakthrough was observed after exposure to liquid MMH, and to vapor and liquid UDMH. No breakthrough was observed after exposure to vapor and liquid hydrazine, or vapor MMH. A model was then used to calculate propellant concentrations inside a totally encapsulating chemical protective suit based on the ASTM permeation data obtained in the present study. Concentrations were calculated under conditions of fixed vapor transmission rate, variable breathing air flow rate, and variable splash exposure area. Calculations showed that the maximum allowable permeation rates of hydrazine fuels through CPE were of the order of 0.05 to 0.08 ng sq cm/min for encapsulating suits with low breathing air flow rates (of the order of 5 scfm or 140 L/min). Above these permeation rates, the 10 parts per billion (ppb) threshold limit value time - weighted average could be exceeded for chemical protective suits having a CPE torso. To evaluate suit performance at ppb level concentrations, use of a sensitive analytical method such as cation exchange high performance liquid chromatography with amperometric detection was found to be essential.

  6. Evolution of density fluctuations to lamellar crystals in linear polyethylene

    SciTech Connect

    Akpalu, Y.A.; Amis, E.J.

    1999-11-01

    Structure formation during the isothermal crystallization of a linear polyethylene (M{sub w}=32&hthinsp;100 g/mol, M{sub w}/M{sub n}=1.1) has been monitored by simultaneous real time small-angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) with synchrotron radiation. Changes in the crystalline and amorphous scattering in WAXS occur simultaneously with the changes observed in the SAXS intensity profile, suggesting that the resulting scattering is a consequence of forming crystals. At the early stage of crystal growth, the SAXS intensity at q{lt}0.02&hthinsp;{Angstrom}{sup {minus}1} increases while that at higher wave vectors remains constant. Meanwhile, the apparent crystallinity from WAXS increases to about 10{percent} before two peaks in the SAXS intensity profile can be resolved. As lamellar stacks develop, the period corresponding to the first SAXS peak, L{sub 1}, decreases initially. After reaching a minimum, L{sub 1} further increases with crystallization time. On the other hand, the period corresponding to the second SAXS peak increases with crystallization time. At late times, the rate of increase is very slow. Changes in the crystallinity obtained from WAXS and the total scattering power from SAXS were evaluated and compared with a model for the crystallizing system which accounts for changes in the fraction of lamellar aggregates. The relative importance of two secondary crystallization processes, namely the formation of new lamellar stacks and increase in the crystallinity within lamellae, were evaluated during and after primary crystallization. {copyright} {ital 1999 American Institute of Physics.}

  7. Alteration of electroosmotic volume flow through skin by polyethylene glycols.

    PubMed

    Lee, Seung Yeon; Oh, Seaung Youl

    2015-07-01

    We have studied the effect of polyethylene glycols (PEGs) on the iontophoretic flux of acetaminophen (AAP) using conventional in vitro iontophoresis methodology. A series of PEGs with average molecular weight (MW) ranging from about 100 to 1,500 was studied. The results were analyzed to explain how PEGs affect the electroosmosis and flux through skin. As a marker molecule for the direction and magnitude of electroosmotic volume flow (EVF), AAP was used. PEG decreased both anodal and cathodal AAP flux markedly. The magnitude of this decrease in flux increased as the MW and the concentration of PEG increased. From the Helmholtz-Smoluchowski equation, it was expected that the increase in viscosity and the decrease in dielectric constant are thought to be the main reason for the decrease in EVF and the flux. The large increase in solubility of AAP in PEG solution may also play an important role, because this increase lowers the partition of AAP into the stratum corneum. When 30 % diethylene glycol solution was used, the magnitude of EVF was estimated to be about 1.5 ?l/cm(2) h, and it decreased as the MW of the PEG increased. These results and discussions clearly suggest that the incorporation of organic solubilizers and penetration enhancers into the iontophoretic formulation should be carefully decided after a thorough understanding of their effect on flux. Overall, these results provide further mechanistic insights into the role of electroosmosis in flux through skin, and how they can be modulated by PEG and their MW. PMID:25331332

  8. Stabilization of DNA Structures with Poly(ethylene sodium phosphate).

    PubMed

    Moriyama, Rui; Iwasaki, Yasuhiko; Miyoshi, Daisuke

    2015-09-10

    The structure and stability of biomolecules under molecular crowding conditions are of interest because such information clarifies how biomolecules behave under cell-mimicking conditions. The anionic surfaces of chromatin, which is composed of DNA strands and histone complexes, are concentrated in cell nuclei and thus generate a polyanionic crowding environment. In this study, we designed and synthesized an anionic polymer, poly(ethylene sodium phosphate) (PEP·Na), which has a nucleic acid phosphate backbone and created a cell nucleus-like environment. The effects of molecular crowding with PEP·Na on the thermodynamics of DNA duplexes, triplexes, and G-quadruplexes were systematically studied. Thermodynamic analysis demonstrated that PEP·Na significantly stabilized the DNA structures; e.g., a free energy change at 25 °C for duplex formation decreased from -6.6 to -12.8 kcal/mol with 20 wt % PEP·Na. Thermodynamic parameters further indicated that the factors for the stabilization of the DNA structures were dependent on sodium ion concentration. At lower polymer concentrations, the stabilization was attributed to a shielding of the electrostatic repulsion between DNA strands by the sodium ions of PEP·Na. In contrast, at higher polymer concentrations, the DNA structures were entropically stabilized by volume exclusion, which could be enhanced by electrostatic repulsion between phosphate groups in DNA strands and in PEP·Na. Additionally, increasing PEP·Na concentration resulted in increasing enthalpy of the DNA duplex but decreasing enthalpy of DNA G-quadruplex, indicating that the polymers also promoted dehydration of the DNA strands. Thus, polyanionic crowding affects the thermodynamics of DNA structures via the sodium ions, volume exclusion, and hydration. The stabilization of DNA by the cell nucleus-like polyanionic crowding provides new information regarding DNA structures and allows for modeling reactions in cell nuclei. PMID:26173001

  9. Structure and antibacterial properties of polyethylene/organo-vermiculite composites

    NASA Astrophysics Data System (ADS)

    Hundáková, Marianna; Tokarský, Jonáš; Valášková, Marta; Slobodian, Petr; Pazdziora, Erich; Kimmer, Dušan

    2015-10-01

    Vermiculite (VER) was modified by cation exchange with hexadecyltrimethylammonium (HDTMA+) bromide in three concentrations and used as organo-VER clay mineral nanofillers (denoted as HDTMA+1-VER, HDTMA+2-VER, and HDTMA+3-VER) in polyethylene (PE). PE/organo-VER composites were prepared via a melt compounding technique and pressed into thin plates. The organo-VER nanofillers and composite plates were characterized by X-ray diffraction analysis which in combination with molecular modeling confirmed the intercalation of HDTMA+ molecules. It was found that alkyl tails of HDTMA+ molecules create a non-polar, water-free area which may help the PE chains to enter the VER interlayer space. The nanocomposite structure was confirmed for PE/HDTMA+3-VER. PE/organo-VER composites were also studied by scanning electron microscopy and light microscopy and by creep testing. Antibacterial activity of powder organo-VER nanofillers was tested on Gram-positive (G+) (Staphylococcus aureus, Enterococcus faecalis) and Gram-negative (G-) (Escherichia coli) bacterial strains. The most sensitive G+ bacteria responded by stopping their bacterial growth after 24 h with a minimum inhibitory concentration (MIC) 0.014% (w/v) at all samples. Growth of G- bacteria was inhibited after 24 h with higher MIC value 0.041-10% (w/v) in relation to the content of HDTMA+ in samples. The surfaces of PE/organo-VER composites are very active against G+ bacterial strain E. faecalis. The number of bacterial colonies forming units (cfu) on surfaces of samples was reduced by approximately several orders. The number of bacterial colonies after 48 h was 0 cfu on the surface of PE/HDTMA+3-VER nanocomposite.

  10. Polyethylene recycling: Waste policy scenario analysis for the EU-27.

    PubMed

    Andreoni, Valeria; Saveyn, Hans G M; Eder, Peter

    2015-08-01

    This paper quantifies the main impacts that the adoption of the best recycling practices together with a reduction in the consumption of single-use plastic bags and the adoption of a kerbside collection system could have on the 27 Member States of the EU. The main consequences in terms of employment, waste management costs, emissions and energy use have been quantified for two scenarios of polyethylene (PE) waste production and recycling. That is to say, a "business as usual scenario", where the 2012 performances of PE waste production and recycling are extrapolated to 2020, is compared to a "best practice scenario", where the best available recycling practices are modelled together with the possible adoption of the amended Packaging and Packaging Waste Directive related to the consumption of single-use plastic bags and the implementation of a kerbside collection system. The main results show that socio-economic and environmental benefits can be generated across the EU by the implementation of the best practice scenario. In particular, estimations show a possible reduction of 4.4 million tonnes of non-recycled PE waste, together with a reduction of around €90 million in waste management costs in 2020 for the best practice scenario versus the business as usual scenario. An additional 35,622 jobs are also expected to be created. In environmental terms, the quantity of CO2 equivalent emissions could be reduced by around 1.46 million tonnes and the net energy requirements are expected to increase by 16.5 million GJ as a consequence of the reduction in the energy produced from waste. The main analysis provided in this paper, together with the data and the model presented, can be useful to identify the possible costs and benefits that the implementation of PE waste policies and Directives could generate for the EU. PMID:25976302

  11. Robust Identification of Polyethylene Terephthalate (PET) Plastics through Bayesian Decision

    PubMed Central

    Zulkifley, Mohd Asyraf; Mustafa, Mohd Marzuki; Hussain, Aini; Mustapha, Aouache; Ramli, Suzaimah

    2014-01-01

    Recycling is one of the most efficient methods for environmental friendly waste management. Among municipal wastes, plastics are the most common material that can be easily recycled and polyethylene terephthalate (PET) is one of its major types. PET material is used in consumer goods packaging such as drinking bottles, toiletry containers, food packaging and many more. Usually, a recycling process is tailored to a specific material for optimal purification and decontamination to obtain high grade recyclable material. The quantity and quality of the sorting process are limited by the capacity of human workers that suffer from fatigue and boredom. Several automated sorting systems have been proposed in the literature that include using chemical, proximity and vision sensors. The main advantages of vision based sensors are its environmentally friendly approach, non-intrusive detection and capability of high throughput. However, the existing methods rely heavily on deterministic approaches that make them less accurate as the variations in PET plastic waste appearance are too high. We proposed a probabilistic approach of modeling the PET material by analyzing the reflection region and its surrounding. Three parameters are modeled by Gaussian and exponential distributions: color, size and distance of the reflection region. The final classification is made through a supervised training method of likelihood ratio test. The main novelty of the proposed method is the probabilistic approach in integrating various PET material signatures that are contaminated by stains under constant lighting changes. The system is evaluated by using four performance metrics: precision, recall, accuracy and error. Our system performed the best in all evaluation metrics compared to the benchmark methods. The system can be further improved by fusing all neighborhood information in decision making and by implementing the system in a graphics processing unit for faster processing speed. PMID:25485630

  12. SANS study of highly resilient poly(ethylene glycol) hydrogels.

    PubMed

    Saffer, Erika M; Lackey, Melissa A; Griffin, David M; Kishore, Suhasini; Tew, Gregory N; Bhatia, Surita R

    2014-03-28

    Polymer networks are critically important for numerous applications including soft biomaterials, adhesives, coatings, elastomers, and gel-based materials for energy storage. One long-standing challenge these materials present lies in understanding the role of network defects, such as dangling ends and loops, developed during cross-linking. These defects can negatively impact the physical, mechanical, and transport properties of the gel. Here we report chemically cross-linked poly(ethylene glycol) (PEG) gels formed through a unique cross-linking scheme designed to minimize defects in the network. The highly resilient mechanical properties of these systems (discussed in a previous publication) [J. Cui, M. A. Lackey, A. E. Madkour, E. M. Saffer, D. M. Griffin, S. R. Bhatia, A. J. Crosby and G. N. Tew, Biomacromolecules, 2012, 13, 584-588], suggests that this cross-linking technique yields more homogeneous network structures. Four series of gels were formed based on chains of 35,000 g mol(-1), (35k), 12,000 g mol(-1) (12k) g mol(-1), 8000 g mol(-1) (8k) and 4000 g mol(-1) (4k) PEG. Gels were synthesized at five initial polymer concentrations ranging from 0.077 g mL(-1) to 0.50 g mL(-1). Small-angle neutron scattering (SANS) was utilized to investigate the network structures of gels in both D2O and d-DMF. SANS results show the resulting network structure is dependent on PEG length, transitioning from a more homogeneous network structure at high molecular weight PEG to a two phase structure at the lowest molecular weight PEG. Further investigation of the transport properties inherent to these systems, such as diffusion, will aid to further confirm the network structures. PMID:24652367

  13. Photodegradation and photostabilization of weathered wood flour filled polyethylene composites

    NASA Astrophysics Data System (ADS)

    Stark, Nicole M.

    2003-06-01

    Wood plastic composites (WPCs) have gained popularity as building materials because of their usefulness in replacing solid wood in a variety of applications. These composites are promoted as being low-maintenance, high-durability products. However, it has been shown that WPCs exposed to weathering may experience a color change and/or loss in mechanical properties. An important requirement for building materials used in outdoor applications is the retention of their aesthetic qualities and mechanical properties during service life. Therefore, it is critical to understand the photodegradation mechanisms of WPCs exposed to UV radiation and to develop approaches to stabilize these composites against ultraviolet light. In this dissertation, the surface chemistries of weathered composites (both unstabilized and stabilized) as well as the effect of weathering on the color fade and the retention of mechanical properties were characterized. Since different methods of manufacturing WPCs lead to different surface characteristics, which can influence weathering, the effect of manufacturing method on the photodegradation of WPCs was investigated first. Wood flour (WF) filled high-density polyethylene (HDPE) composite samples were either injection molded, extruded, or extruded and then planed. Fourier transform infrared (FTIR) spectroscopy was used to monitor the surface chemistry of the manufactured composites. The spectra showed that the surface of planed samples had more wood component than extruded and injection molded samples, respectively. After weathering, the samples were analyzed for color fade, and loss of flexural properties. The final lightness of the composites was not dependent upon the manufacturing method. However the mechanical property loss was dependent upon manufacturing method. The samples with more wood component at the surface (planed samples) experienced a larger percent of total loss in flexural properties after weathering due to a greater effect of moisture on the samples. The change in surface chemistry of HDPE and WF/HDPE composites after weathering was studied using spectroscopic techniques. (Abstract shortened by UMI.)

  14. Robust identification of polyethylene terephthalate (PET) plastics through Bayesian decision.

    PubMed

    Zulkifley, Mohd Asyraf; Mustafa, Mohd Marzuki; Hussain, Aini; Mustapha, Aouache; Ramli, Suzaimah

    2014-01-01

    Recycling is one of the most efficient methods for environmental friendly waste management. Among municipal wastes, plastics are the most common material that can be easily recycled and polyethylene terephthalate (PET) is one of its major types. PET material is used in consumer goods packaging such as drinking bottles, toiletry containers, food packaging and many more. Usually, a recycling process is tailored to a specific material for optimal purification and decontamination to obtain high grade recyclable material. The quantity and quality of the sorting process are limited by the capacity of human workers that suffer from fatigue and boredom. Several automated sorting systems have been proposed in the literature that include using chemical, proximity and vision sensors. The main advantages of vision based sensors are its environmentally friendly approach, non-intrusive detection and capability of high throughput. However, the existing methods rely heavily on deterministic approaches that make them less accurate as the variations in PET plastic waste appearance are too high. We proposed a probabilistic approach of modeling the PET material by analyzing the reflection region and its surrounding. Three parameters are modeled by Gaussian and exponential distributions: color, size and distance of the reflection region. The final classification is made through a supervised training method of likelihood ratio test. The main novelty of the proposed method is the probabilistic approach in integrating various PET material signatures that are contaminated by stains under constant lighting changes. The system is evaluated by using four performance metrics: precision, recall, accuracy and error. Our system performed the best in all evaluation metrics compared to the benchmark methods. The system can be further improved by fusing all neighborhood information in decision making and by implementing the system in a graphics processing unit for faster processing speed. PMID:25485630

  15. SLIDING DIRECTION-DEPENDENCE OF POLYETHYLENE WEAR FOR METAL COUNTERFACE TRAVERSE OF SEVERE SCRATCHES

    PubMed Central

    Glennon, Liam P.; Baer, Thomas E.; Martin, James A.; Lack, William D.; Brown, Thomas D.

    2008-01-01

    Third body effects appear to be responsible for an appreciable portion of the wear rate variability within cohorts of patients with metal-on-polyethylene joint replacements. The parameters dominating the rate of polyethylene debris liberation by counterface scratches are not fully understood, but one seemingly contributory factor is the scratch’s orientation relative to the direction of instantaneous local surface sliding. To study this influence, arrays of 550 straight parallel scratches each representative of the severe end of the clinical range were diamond stylus-ruled onto the surface of polished stainless steel plates. These ruled plates were then worn reciprocally against polyethylene pins (both conventional and highly cross-linked) at traverse angles varied parametrically relative to the scratch direction. Wear was measured gravimetrically, and particulate debris was harvested and morphologically characterized. Both of the polyethylene variants tested showed pronounced wear rate peaks at acute scratch traverse angles (15º for conventional, 5º for cross-linked), and had nominally comparable absolute wear rate magnitudes. The particulate debris from this very aggressive test regime primarily consisted of extremely large and elongated strands, often tens or even hundreds of microns in length. These data suggest that counterface damage regions with preferential scratch directionality can liberate large amounts of polyethylene debris, apparently by a slicing/shearing mechanism, at critical (acute) attack angles. However, the predominant manifestation of this wear volume was in the form of particles far beyond the most osteolytically potent size range. PMID:19045513

  16. Crystallization Kinetics of Indomethacin/Polyethylene Glycol Dispersions Containing High Drug Loadings.

    PubMed

    Duong, Tu Van; Van Humbeeck, Jan; Van den Mooter, Guy

    2015-07-01

    The reproducibility and consistency of physicochemical properties and pharmaceutical performance are major concerns during preparation of solid dispersions. The crystallization kinetics of drug/polyethylene glycol solid dispersions, an important factor that is governed by the properties of both drug and polymer has not been adequately explored, especially in systems containing high drug loadings. In this paper, by using standard and modulated differential scanning calorimetry and X-ray powder diffraction, we describe the influence of drug loading on crystallization behavior of dispersions made up of indomethacin and polyethylene glycol 6000. Higher drug loading increases the amorphicity of the polymer and inhibits the crystallization of PEG. At 52% drug loading, polyethylene glycol was completely transformed to the amorphous state. To the best of our knowledge, this is the first detailed investigation of the solubilization effect of a low molecular weight drug on a semicrystalline polymer in their dispersions. In mixtures containing up to 55% indomethacin, the dispersions exhibited distinct glass transition events resulting from amorphous-amorphous phase separation which generates polymer-rich and drug-rich domains upon the solidification of supercooled polyethylene glycol, whereas samples containing at least 60% drug showed a single amorphous phase during the period in which crystallization normally occurs. The current study demonstrates a wide range in physicochemical properties of drug/polyethylene glycol solid dispersions as a result of the complex nature in crystallization of this system, which should be taken into account during preparation and storage. PMID:26056715

  17. Enhanced adherence of mouse fibroblast and vascular cells to plasma modified polyethylene.

    PubMed

    Reznickova, Alena; Novotna, Zdenka; Kolska, Zdenka; Kasalkova, Nikola Slepickova; Rimpelova, Silvie; Svorcik, Vaclav

    2015-07-01

    Since the last decade, tissue engineering has shown a sensational promise in providing more viable alternatives to surgical procedures for harvested tissues, implants and prostheses. Biomedical polymers, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE), were activated by Ar plasma discharge. Degradation of polymer chains was examined by determination of the thickness of ablated layer. The amount of an ablated polymer layer was measured by gravimetry. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Chemical structure of modified polymers was characterized by angle resolved X-ray photoelectron spectroscopy. Surface chemistry and polarity of the samples were investigated by electrokinetic analysis. Changes in surface morphology were followed using atomic force microscopy. Cytocompatibility of plasma activated polyethylene foils was studied using two distinct model cell lines; VSMCs (vascular smooth muscle cells) as a model for vascular graft testing and connective tissue cells L929 (mouse fibroblasts) approved for standardized material cytotoxicity testing. Specifically, the cell number, morphology, and metabolic activity of the adhered and proliferated cells on the polyethylene matrices were studied in vitro. It was found that the plasma treatment caused ablation of the polymers, resulting in dramatic changes in their surface morphology and roughness. ARXPS and electrokinetic measurements revealed oxidation of the polymer surface. It was found that plasma activation has a positive effect on the adhesion and proliferation of VSMCs and L929 cells. PMID:25953566

  18. Tribology, UV degradation, and structure-property-processing relationships of detonation nanodiamond-polyethylene nanocomposites

    NASA Astrophysics Data System (ADS)

    Tipton, John

    Nanoscale reinforcements offer the possibility of coupling the already proven high strength to weight properties of polymer matrix composites with additional multifunctional properties such as electrical conductivity, thermal conductivity, unique optics, UV/IR radiation absorption, and enhanced wear resistance. This work presents materials based on detonation nanodiamonds dispersed in two types of polyethylene. The work begins with an understanding of nucleation phenomena. It was discovered through isothermal kinetics using differential scanning calorimetry that nanodiamonds act as nucleating agents during polyethylene crystallization. A processing technique to disperse nanodiamonds into very viscous ultra-high molecular weight polyethylene was developed and analyzed. These composites were further studied using dynamic mechanical analysis which showed increases in both stiffness and energy absorbing modes over unfilled UHMWPE. Exposure to UV degradation caused a failure of the polymer microstructure which was found to be caused by residual tensile stresses between the polymer particles formed during processing. These high stress regions were more prone to photo oxidation even though the nanodiamond particles were shown to decrease surface oxidation. Additionally, the tribological properties of UHMWPE/nanodiamond composites were investigated. Ultra-high molecular weight polyethylene is an already proven ultra tough and wear resistant polymer that is used in many high performance thermoplastic applications such as bearings, surfaces (skids/wheels), ropes/nets, and orthopedic implants. This work showed that UHMWPE loaded with 5.0wt% nanodiamonds might be a candidate to replace the currently used crosslinked polyethylene material used in orthopedic implants.

  19. OBT analysis method using polyethylene beads for limited quantities of animal tissue.

    PubMed

    Kim, S B; Stuart, M

    2015-08-01

    This study presents a polyethylene beads method for OBT determination in animal tissues and animal products for cases where the amount of water recovered by combustion is limited by sample size or quantity. In the method, the amount of water recovered after combustion is enhanced by adding tritium-free polyethylene beads to the sample prior to combustion in an oxygen bomb. The method reduces process time by allowing the combustion water to be easily collected with a pipette. Sufficient water recovery was achieved using the polyethylene beads method when 2 g of dry animal tissue or animal product were combusted with 2 g of polyethylene beads. Correction factors, which account for the dilution due to the combustion water of the beads, are provided for beef, chicken, pork, fish and clams, as well as egg, milk and cheese. The method was tested by comparing its OBT results with those of the conventional method using animal samples collected on the Chalk River Laboratories (CRL) site. The results determined that the polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used. PMID:25913056

  20. Protein crystal growth; Proceedings of the First International Conference, Stanford University, CA, August 14-16, 1985

    NASA Technical Reports Server (NTRS)

    Feigelson, R. S. (editor)

    1986-01-01

    Papers are presented on mechanisms of nucleation and growth of protein crystals, the role of purification in the crystallization of proteins and nucleic acids, and the effect of chemical impurities in polyethylene glycol on macromolecular crystallization. Also considered are growth kinetics of tetragonal lysozyme crystals, thermodynamic and kinetic considerations for crystal growth of complex molecules from solution, protein single-crystal growth under microgravity, and growth of organic crystals in a microgravity environment. Papers are also presented on preliminary investigations of protein crystal growth using the Space Shuttle, convective diffusion in protein crystal growth, and the growth and characterization of membrane protein crystals.

  1. Tribological Evaluation of Nanostructured Diamond Coatings and CoCr against Ultra-High Molecular Weight Polyethylene

    PubMed Central

    Hill, Michael R.; Catledge, Shane A.; Konovalov, Valeriy; Clem, William C.; Chowdhury, Shafiul A.; Etheridge, Brandon S.; Stanishevsky, Andrei; Lemons, Jack E.; Vohra, Yogesh K.; Eberhardt, Alan W.

    2008-01-01

    Background Some loss of joint prostheses has been attributed to osteolytic phenomena leading to loosening and associated with debris from wear of polyethylene articulating against metal alloys. Reduced polyethylene wear has been reported with ceramics serving as an alternative counterface. Methods Nanostructured Diamond (NSD) coatings were deposited onto Ti6A14V by microwave plasma-assisted chemical vapor deposition, with both hydrogen-rich (H-NSD) and helium-rich (He-NSD) feedgas mixtures. Pin-on-disk wear tests of polyethylene against NSD and CoCr were performed in serum lubrication at body temperature. Scanning electron microscopy was used to examine surface morphology, and nanoindentation was used to determine hardness and modulus of the polyethylene pins. Raman spectroscopy, surface roughness, and wettability analyses of NSD coatings were performed. Results Raman spectroscopy confirmed sp2 and sp3 bonded carbon. No significant differences in wear factors were found between polyethylene on H-NSD, He-NSD, and CoCr, despite higher roughness and friction coefficient for the He-NSD and H-NSD coatings, compared to CoCr. Contact angles for the diamond coatings were reduced following the wear tests, indicating that these surfaces became more hydrophilic. Multiple pimples were observed on pins articulated against CoCr, and a single, large protuberance was observed in polyethylene-on-NSD These features were conjectured to be re-consolidated polyethylene particles. Nanoindentation modulus and hardness of the worn polyethylene surfaces were lower for polyethylene-on-diamond than for polyethylene-on-CoCr. Conclusions As a counterface to polyethylene, the NSD coatings produced wear factors comparable to CoCr in the present pin-on-disk tests. Thus, NSD-coated Ti6A14V shows promise for use in joint replacement bearing applications. PMID:17853416

  2. Immobilized metal ion affinity partitioning, a method combining metal-protein interaction and partitioning of proteins in aqueous two-phase systems.

    PubMed

    Birkenmeier, G; Vijayalakshmi, M A; Stigbrand, T; Kopperschläger, G

    1991-02-22

    Immobilized metal ions were used for the affinity extraction of proteins in aqueous two-phase systems composed of polyethylene glycol (PEG) and dextran or PEG and salt. Soluble chelating polymers were prepared by covalent attachment of metal-chelating groups to PEG. The effect on the partitioning of proteins of such chelating PEG derivatives coordinated with different metal ions is demonstrated. The proteins studied were alpha 2-macroglobulin, tissue plasminogen activator, superoxide dismutase and monoclonal antibodies. The results indicate that immobilized metal ion affinity partitioning provides excellent potential for the extraction of proteins. PMID:1710621

  3. Protein Condensation

    NASA Astrophysics Data System (ADS)

    Gunton, James D.; Shiryayev, Andrey; Pagan, Daniel L.

    2007-09-01

    Preface; 1. Introduction; 2. Globular protein structure; 3. Experimental methods; 4. Thermodynamics and statistical mechanics; 5. Protein-protein interactions; 6. Theoretical studies of equilibrium; 7. Nucleation theory; 8. Experimental studies of nucleation; 9. Lysozyme; 10. Some other globular proteins; 11. Membrane proteins; 12. Crystallins and cataracts; 13. Sickle hemoglobin and sickle cell anemia; 14, Alzheimer's disease; Index.

  4. Protein Condensation

    NASA Astrophysics Data System (ADS)

    Gunton, James D.; Shiryayev, Andrey; Pagan, Daniel L.

    2014-07-01

    Preface; 1. Introduction; 2. Globular protein structure; 3. Experimental methods; 4. Thermodynamics and statistical mechanics; 5. Protein-protein interactions; 6. Theoretical studies of equilibrium; 7. Nucleation theory; 8. Experimental studies of nucleation; 9. Lysozyme; 10. Some other globular proteins; 11. Membrane proteins; 12. Crystallins and cataracts; 13. Sickle hemoglobin and sickle cell anemia; 14, Alzheimer's disease; Index.

  5. AL-SX (H1616) Container Support: Out-gassing of Polyethylene and Polycarbonate Resins

    SciTech Connect

    G.Cook Story; Leon Seibel and Linda Domeier

    1999-04-01

    Out-gassing tests were carried out on samples of polyethylene and polycarbonate packaging components used within the AL-SX (H1616) shipping container and compared to known samples of high and low density polyethylene and polycarbonate. Polyethylene is used to fabricate the shipping container overpack for the MC3007A/MC4059 and 1X-Acorn; LEXAN{reg_sign} polycarbonate (General Electric) is used to fabricate the lid of the Protective Container utilized to package the MC4213/MC4240 and MC4524 for shipment in the AL-SX (H1616). Pressure was monitored up to about 650 F and all the samples showed similar increases in pressure which were only slightly above those measured for control runs using no resin sample. None of the polymer samples showed out-gassing behavior that would lead to excessive pressure increases in the H1616 within that temperature range.

  6. Effect of Polyethylene Crosslinking and Bearing Design on Wear of Unicompartmental Arthroplasty.

    PubMed

    Netter, Jonathan; Hermida, Juan C; D'Alessio, Jerry; Kester, Mark; D'Lima, Darryl D

    2015-08-01

    Wear and polyethylene damage continue to be important factors affecting outcomes of unicompartmental knee arthroplasty. We compared two design rationales for unicompartmental arthroplasty: fully congruent mobile bearings; or moderately conforming fixed bearings using experimental and computational wear simulation. Experimental wear rates were 3.89 (±0.12) mg/million cycles for the highly crosslinked Triathlon PKR fixed bearing compared to 18.35 (±0.19) mg/million cycles for the low crosslinked Oxford mobile bearing. Finite element analysis was used to calculate the effect of crosslinking and backside wear. Increase in polyethylene crosslinking reduced wear by 68% while backside wear comprised 46% of the total wear in the mobile bearing. Increasing conformity may not be the sole predictor of wear performance and highly crosslinked fixed-bearing polyethylene insert can also provide high wear performance. PMID:25865811

  7. New data on long term stabilization of polyethylene for telecommunication wire insulation

    NASA Astrophysics Data System (ADS)

    Meyer, F. K.; Linhart, H.

    Medium density polyethylene is widely used for the insulation of telecommunication wires. A lifetime of 40 to 50 years is generally desired. Thus the stabilization of the polyethylene in contact with copper is of prime importance. In this paper new data pertaining to the long term heat stabilization are presented. The loss of stabilizers as a function of time is examined and aging data on actual wires are shown. There is evidence that polyethylene stabilized with a combination of a sterically hindered phenolic antioxidant (penetaerythrityl tetrakis (3.5-di-t-butyl-4-hydroxyphenyl propionate) and a copper deactivator (N, N'-bis (beta-3.5-di-t-butyl-4-hydroxypenyl-propiono) hydrazide) has good chances of reaching the expected lifetime.

  8. Urethane-based stabilizers for radiation-crosslinked polyethylene. [Electron beams

    SciTech Connect

    Shkolnik, S.; Rajbenbach, L.A.

    1982-11-01

    Unsaturated urethane-based stabilizers for use in radiation-crosslinked polyethylene were synthesized. Aromatic amine moieties were attached to allylic and acrylic monomers by means of aromatic or aliphatic diisocyanates. The synthesized stabilizers were incorporated in high-density polyethylene films which were subjected to electron beam irradiation. The oxidative stability of the films prior to and after extraction was determined by DTA in the temperature range 185-210/sup 0/C and compared with samples treated with commercial amine-bearing antioxidants. Tensile strength and gel content were also determined. Best results were obtained with a stabilizer prepared from equimolecular amounts of allyl alcohol, tolylene-2,4-diisocyanate and N-phenyl-1,4-phenylenediamine. Estimated lifetimes at 70/sup 0/C of stabilized irradiated polyethylene samples were calculated.

  9. An atomistic description of the high-field degradation of dielectric polyethylene

    SciTech Connect

    Bealing, Clive R.; Ramprasad, R.

    2013-11-07

    A microscopic mechanism governing the initiating step in the high-field aging of crystalline polyethylene is proposed, based on density functional calculations and ab initio molecular dynamics simulations. It is assumed that electrons, holes, and excitons are present in the system. While the additional individual electrons or holes are not expected to lead to significant degradation, the presence of triplet excitons are concluded to be rather damaging. The electron and hole states of the exciton localize on a distorted region of polyethylene, significantly weakening nearby C–H bonds and facilitating C–H bond scission. The barrier to cleavage of the weakened C–H bonds is estimated and is comparable to the thermal energy, suggesting that this mechanism may be responsible for the degradation of polyethylene when placed under electrical stress, e.g., in high-voltage cables.

  10. Capturing Knowledge In Order To Optimize The Cutting Process For Polyethylene Pipes Using Knowledge Models

    NASA Astrophysics Data System (ADS)

    Rotaru, Ionela Magdalena

    2015-09-01

    Knowledge management is a powerful instrument. Areas where knowledge - based modelling can be applied are different from business, industry, government to education area. Companies engage in efforts to restructure the database held based on knowledge management principles as they recognize in it a guarantee of models characterized by the fact that they consist only from relevant and sustainable knowledge that can bring value to the companies. The proposed paper presents a theoretical model of what it means optimizing polyethylene pipes, thus bringing to attention two important engineering fields, the one of the metal cutting process and gas industry, who meet in order to optimize the butt fusion welding process - the polyethylene cutting part - of the polyethylene pipes. All approach is shaped on the principles of knowledge management. The study was made in collaboration with companies operating in the field.

  11. Synthesis and morphology of hydroxyapatite/polyethylene oxide nanocomposites with block copolymer compatibilized interfaces

    NASA Astrophysics Data System (ADS)

    Lee, Ji Hoon; Shofner, Meisha

    2012-02-01

    In order to exploit the promise of polymer nanocomposites, special consideration should be given to component interfaces during synthesis and processing. Previous results from this group have shown that nanoparticles clustered into larger structures consistent with their native shape when the polymer matrix crystallinity was high. Therefore in this research, the nanoparticles are disguised from a highly-crystalline polymer matrix by cloaking them with a matrix-compatible block copolymer. Specifically, spherical and needle-shaped hydroxyapatite nanoparticles were synthesized using a block copolymer templating method. The block copolymer used, polyethylene oxide-b-polymethacrylic acid, remained on the nanoparticle surface following synthesis with the polyethylene oxide block exposed. These nanoparticles were subsequently added to a polyethylene oxide matrix using solution processing. Characterization of the nanocomposites indicated that the copolymer coating prevented the nanoparticles from assembling into ordered clusters and that the matrix crystallinity was decreased at a nanoparticle spacing of approximately 100 nm.

  12. Flat-on-flat, nonconstrained, compression molded polyethylene total knee replacement.

    PubMed

    Ritter, M A; Worland, R; Saliski, J; Helphenstine, J V; Edmondson, K L; Keating, E M; Faris, P M; Meding, J B

    1995-12-01

    Flat-on-flat, posterior cruciate ligament-sparing total knee prostheses recently have shown problems of wear, loosening, and multiple design changes. Two thousand one Anatomical Graduated Components total knee arthroplasties with compression molded, nonmodular polyethylene tibial components were done between 1983 and 1991 at 3 institutions. All knees were evaluated clinically and radiographically every 2 to 3 years; 71 knees were seen in followup > 10 years. There were 8 failures secondary to revision (5 tibial failures; 2 secondary to metalosis from patellar polyethylene dissociation; and 3 femoral failures) resulting in a 98% survival rate at 10 years. The tibial design was flat-on-flat with a compression molded polyethylene that the authors believe is the primary reason for its success. PMID:7497689

  13. High-pressure crystalline polyethylene studied by x-ray diffraction and ab initio simulations

    SciTech Connect

    Fontana, L.; Vinh, Diep Q.; Santoro, M.; Gorelli, F. A.; Hanfland, M.

    2007-05-01

    Crystalline polyethylene was investigated under pressure between 0 and 40 GPa, up to 280 deg. C, by means of synchrotron x-ray powder diffraction and ab initio calculations. A rich polymorphism was unveiled, consisting of two new high-pressure monoclinic phases, in addition to the well-known orthorhombic one, which appear reversibly, although with strong hysteresis, upon increasing pressure above 6 GPa (P2{sub 1}/m, Z{sub chain}=1) and 14-16 GPa (A2/m, Z{sub chain}=2), respectively. The equation of state was determined for the three solid phases. We find that polyethylene is characterized by a sharp separation between strong covalent intrachain and weaker interchain interactions up to the maximum investigated pressure, which, in turn, places the ultimate chemical stability limit of polyethylene far beyond these thermodynamic conditions.

  14. Optimization of serine protease purification from mango (Mangifera indica cv. Chokanan) peel in polyethylene glycol/dextran aqueous two phase system.

    PubMed

    Mehrnoush, Amid; Mustafa, Shuhaimi; Sarker, Md Zaidul Islam; Yazid, Abdul Manap Mohd

    2012-01-01

    Mango peel is a good source of protease but remains an industrial waste. This study focuses on the optimization of polyethylene glycol (PEG)/dextran-based aqueous two-phase system (ATPS) to purify serine protease from mango peel. The activity of serine protease in different phase systems was studied and then the possible relationship between the purification variables, namely polyethylene glycol molecular weight (PEG, 4000-12,000 g·mol(-1)), tie line length (-3.42-35.27%), NaCl (-2.5-11.5%) and pH (4.5-10.5) on the enzymatic properties of purified enzyme was investigated. The most significant effect of PEG was on the efficiency of serine protease purification. Also, there was a significant increase in the partition coefficient with the addition of 4.5% of NaCl to the system. This could be due to the high hydrophobicity of serine protease compared to protein contaminates. The optimum conditions to achieve high partition coefficient (84.2) purification factor (14.37) and yield (97.3%) of serine protease were obtained in the presence of 8000 g·mol(-1) of PEG, 17.2% of tie line length and 4.5% of NaCl at pH 7.5. The enzymatic properties of purified serine protease using PEG/dextran ATPS showed that the enzyme could be purified at a high purification factor and yield with easy scale-up and fast processing. PMID:22489172

  15. Regulating the surface poly(ethylene glycol) density of polymeric nanoparticles and evaluating its role in drug delivery in vivo.

    PubMed

    Du, Xiao-Jiao; Wang, Ji-Long; Liu, Wei-Wei; Yang, Jin-Xian; Sun, Chun-Yang; Sun, Rong; Li, Hong-Jun; Shen, Song; Luo, Ying-Li; Ye, Xiao-Dong; Zhu, Yan-Hua; Yang, Xian-Zhu; Wang, Jun

    2015-11-01

    Poly(ethylene glycol) (PEG) is usually used to protect nanoparticles from rapid clearance in blood. The effects are highly dependent on the surface PEG density of nanoparticles. However, there lacks a detailed and informative study in PEG density and in vivo drug delivery due to the critical techniques to precisely control the surface PEG density when maintaining other nano-properties. Here, we regulated the polymeric nanoparticles' size and surface PEG density by incorporating poly(?-caprolactone) (PCL) homopolymer into poly(ethylene glycol)-block-poly(?-caprolactone) (PEG-PCL) and adjusting the mass ratio of PCL to PEG-PCL during the nanoparticles preparation. We further developed a library of polymeric nanoparticles with different but controllable sizes and surface PEG densities by changing the molecular weight of the PCL block in PEG-PCL and tuning the molar ratio of repeating units of PCL (CL) to that of PEG (EG). We thus obtained a group of nanoparticles with variable surface PEG densities but with other nano-properties identical, and investigated the effects of surface PEG densities on the biological behaviors of nanoparticles in mice. We found that, high surface PEG density made the nanoparticles resistant to absorption of serum protein and uptake by macrophages, leading to a greater accumulation of nanoparticles in tumor tissue, which recuperated the defects of decreased internalization by tumor cells, resulting in superior antitumor efficacy when carrying docetaxel. PMID:26275857

  16. FETs Based on Doped Polyaniline/Polyethylene Oxide Fibers

    NASA Technical Reports Server (NTRS)

    Theofylaktos, Noulie; Robinson, Daryl; Miranda, Felix; Pinto, Nicholas; Johnson, Alan, Jr.; MacDiarmid, Alan; Mueller, Carl

    2006-01-01

    A family of experimental highly miniaturized field-effect transistors (FETs) is based on exploitation of the electrical properties of nanofibers of polyaniline/ polyethylene oxide (PANi/PEO) doped with camphorsulfonic acid. These polymer-based FETs have the potential for becoming building blocks of relatively inexpensive, low-voltage, highspeed logic circuits that could supplant complementary metal oxide/semiconductor (CMOS) logic circuits. The development of these polymerbased FETs offers advantages over the competing development of FETs based on carbon nanotubes. Whereas it is difficult to control the molecular structures and, hence, the electrical properties of carbon nanotubes, it is easy to tailor the electrical properties of these polymerbased FETs, throughout the range from insulating through semiconducting to metallic, through choices of doping levels and chemical manipulation of polymer side chains. A further advantage of doped PANi/PEO nanofibers is that they can be made to draw very small currents and operate at low voltage levels, and thus are promising for applications in which there are requirements to use many FETs to obtain large computational capabilities while minimizing power demands. Fabrication of an experimental FET in this family begins with the preparation of a substrate as follows: A layer of silicon dioxide between 50 and 200 nm thick is deposited on a highly doped (resistivity 0.01 W.cm) silicon substrate, then gold electrodes/contact stripes are deposited on the oxide. Next, one or more fibers of camphorsulphonic acid-doped PANi/PEO having diameters of the order of 100 nm are electrospun onto the substrate so as to span the gap between the gold electrodes (see Figure 1). Figure 2 depicts measured current-versus-voltage characteristics of the device of Figure 1, showing that saturation channel currents occur at source-todrain potentials that are surprisingly low, relative to those of CMOS FETs. The hole mobility in the depletion regime in this transistor was found to be 1.4 10(exp -4) sq cm/(V.s), while the one-dimensional charge density at zero gate bias was estimated to be approximately one hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx. 10(exp -3) S/cm). Reducing or eliminating the PEO content of the fibers is expected to enhance the properties of future versions of this transistor.

  17. Total protein

    MedlinePLUS

    The total protein test measures the total amount of two classes of proteins found in the fluid portion of your blood. These are albumin and globulin. Proteins are important parts of all cells and tissues. ...

  18. Protein C

    MedlinePLUS

    Protein C is a normal substance in the body that prevents blood clotting. A blood test can be done ... forming (anticoagulants), such as warfarin (Coumadin), decrease protein C and protein S levels. Your doctor may ask you ...

  19. Effect of nano-fibers on the stress-strain behavior of semi-crystalline poly(ethylene terephthalate) at different strain rates

    E-print Network

    Cohen, Ellann

    2008-01-01

    Uniaxial compression tests were performed on amorphous poly(ethylene terephthalate) (PET), amorphous poly(ethylene terephthalate)- glycol (PETG), semi-crystalline PET, and semicrystalline PET with various amounts of ...

  20. 76 FR 45508 - Polyethylene Terephthalate Film, Sheet and Strip From the United Arab Emirates: Extension of Time...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Antidumping and Countervailing Duty Administrative Reviews and Request for Revocation in Part, 75 FR 81565... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From the United Arab... of the antidumping duty order on polyethylene terephthalate film, sheet and strip from the...