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1

Poly(ethylene glycol)-modified phospholipids prevent aggregation during covalent conjugation of proteins to liposomes.  

PubMed

Liposome aggregation is a major problem associated with the covalent attachment of proteins to liposomes. This report describes a procedure for coupling proteins to liposomes that results in little or no change in liposome size. This is achieved by incorporating appropriate levels of poly(ethylene glycol)-modified lipids into the liposomes. The studies employed thiolated avidin-D coupled to liposomes containing the thio-reactive lipid N-(4-(p-maleimidophenyl)butyryl)dipalmitoyl phosphatidylethanolamine (1 mol % of total lipid) and various amounts of MePEG-S-POPE (monomethoxypoly(ethylene glycol) linked to phosphatidylethanolamine via a succinate linkage). The influence of PEG chain length and density was also assessed. The presence of PEG on the surface of liposomes is shown to provide an effective method of inhibiting aggregation and the corresponding increase in liposome size during the covalent coupling of avidin-D. A balance between the size of the PEG used and the amount of PEG-lipid incorporated into the liposome had to be achieved in order to maintain efficient coupling. Optimal coupling efficiencies in combination with minimal aggregation effects were achieved using 2 mol % MePEG2000-S-POPE (PEG of 2000 MW) or 0.8 mol % MePEG5000-S-POPE (PEG of 5000 MW). At these levels, the presence of PEG did not affect the biotin binding activity of the covalently attached avidin. The ability of the resulting liposomes to specifically target to biotinylated cells is demonstrated. PMID:7599262

Harasym, T O; Tardi, P; Longman, S A; Ansell, S M; Bally, M B; Cullis, P R; Choi, L S

1995-01-01

2

Transactivating-transduction protein-polyethylene glycol modified liposomes traverse the blood-spinal cord and blood-brain barriers?  

PubMed Central

Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fluorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers. PMID:25317128

Zhou, Xianhu; Wang, Chunyuan; Feng, Shiqing; Chang, Jin; Kong, Xiaohong; Liu, Yang; Gao, Shijie

2012-01-01

3

Poly(ethylene glycol)-Modified Ligninase Enhances Pentachlorophenol  

E-print Network

such as poly(ethylene gly- col) (PEG, also referred to as poly(ethylene oxide), PEO) appeared to be a feasiblePoly(ethylene glycol)-Modified Ligninase Enhances Pentachlorophenol Biodegradation in WaterP) from Phanerochaete chryso- sporium was modified by poly(ethylene glycol) to en- hance its activity

Wang, Ping

4

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

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

5

Poly(ethylene glycol)Modified Proteins: Implications for Poly(lactide-co-glycolide)Based Microsphere Delivery  

Microsoft Academic Search

The reduced injection frequency and more nearly constant serum concentrations afforded by sustained release devices have been\\u000a exploited for the chronic delivery of several therapeutic peptides via poly(lactide-co-glycolide) (PLG) microspheres. The\\u000a clinical success of these formulations has motivated the exploration of similar depot systems for chronic protein delivery;\\u000a however, this application has not been fully realized in practice. Problems with

Sheetal S. Pai; Robert D. Tilton; Todd M. Przybycien

2009-01-01

6

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

E-print Network

) (PEG)/ poly(ethylene oxide) (PEO) has emerged as a strategy to enhance solubility of hydrophobic drugsExpert Review Poly(ethylene glycol)-modified Nanocarriers for Tumor-targeted and Intracellular and action at non- specific sites. Surface modification of nanoparticulate carriers with poly(ethylene glycol

Sridhar, Srinivas

7

Structure of poly(ethylene glycol)-modified horseradish peroxidase in organic solvents: infrared amide I spectral changes upon protein dehydration are largely caused by protein structural changes and not by water removal per se.  

PubMed Central

Fourier transform infrared (FTIR) spectroscopy has emerged as a powerful tool to guide the development of stable lyophilized protein formulations by providing information on the structure of proteins in amorphous solids. The underlying assumption is that IR spectral changes in the amide I and III region upon protein dehydration are caused by protein structural changes. However, it has been claimed that amide I IR spectral changes could be the result of water removal per se. Here, we investigated whether such claims hold true. The structure of horseradish peroxidase (HRP) and poly(ethylene glycol)-modified HRP (HRP-PEG) has been investigated under various conditions (in aqueous solution, the amorphous dehydrated state, and dissolved/suspended in toluene and benzene) by UV-visible (UV-Vis), FTIR, and resonance Raman spectroscopy. The resonance Raman and UV-Vis spectra of dehydrated HRP-PEG dissolved in neat toluene or benzene were very similar to that of HRP in aqueous buffer, and thus the heme environment (heme iron spin, coordination, and redox state) was essentially the same under both conditions. Therefore, the three-dimensional structure of HRP-PEG dissolved in benzene and toluene was similar to that in aqueous solution. The amide I IR spectra of HRP-PEG in aqueous buffer and of dehydrated HRP-PEG dissolved in neat benzene and toluene were also very similar, and the secondary structure compositions (percentages of alpha-helices and beta-sheets) were within the standard error the same. These results are irreconcilable with recent claims that water removal per se could cause substantial amide I IR spectral changes (M. van de Weert, P.I. Haris, W.E. Hennink, and D.J. Crommelin. 2001. Anal. Biochem. 297:160-169). On the contrary, amide I IR spectral changes upon protein dehydration are caused by perturbations in the secondary structure. PMID:12496131

Al-Azzam, Wasfi; Pastrana, Emil A; Ferrer, Yancy; Huang, Qing; Schweitzer-Stenner, Reinhard; Griebenow, Kai

2002-01-01

8

Chromatographic methods for characterization of poly(ethylene glycol)-modified polyamidoamine dendrimers.  

PubMed

The objective of this study was to develop chromatographic methods for the determination of the modification degree and the characterization of poly(ethylene glycol)-modified polyamidoamine dendrimers (PEG-PAMAMs). The PEG-PAMAMs were prepared by reacting PAMAM generation 4 with monomethoxy PEG-nitrophenyl carbonate (mPEG-NPC). The modification degrees of PEG-PAMAMs were determined by quantifying 4-nitrophenol released from mPEG-NPC after PEGylation reaction using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. The PEG-PAMAMs, which have poor UV absorbances, were characterized by HPLC with charged aerosol detection. This study demonstrates that the combination of these two detectors is a powerful tool for the preparation and characterization of PEG-PAMAMs. PMID:24361709

Park, Eun Ji; Cho, Hoon; Kim, Si Wouk; Na, Dong Hee

2014-03-15

9

Effect of supercritical carbon dioxide as an exfoliation aid on bio-based polyethylene terephthalate glycol-modified/clay nanocomposites  

NASA Astrophysics Data System (ADS)

Bio-based PETG (bio-based glycol modified polyethylene terephthalate, Ecozen T95) / clay (organo-modified montmorillonite, OMMT, C10A) nanocomposites were prepared by co-rotating twin screw extruder attached with supercritical carbon dioxide (scCO2) injection system. The effects of nano-clay and scCO2 on the properties of PETG/clay nanocomposites were investigated by measuring thermal, rheological, tensile, impact, and barrier properties. The thermal and mechanical properties decreased with increasing nano-clay content, but they recovered or even exceeded the properties of neat PETG as scCO2 was added. It was verified due to a good dispersion of the nano-clay in PETG matrix for PETG/clay nanocomposites by XRD, SEM, and TEM. It was thought that scCO2 could be an effective exfoliation agent for many nanocomposites systems as well as for bio-based PET/clay nanocomposites.

Jang, Kwangho; Lee, Jae Wook; Hong, In-Kwon; Lee, Sangmook

2013-08-01

10

Sorption of adamantanes on polyethylene glycol-modified graphitized thermal soot  

NASA Astrophysics Data System (ADS)

The thermodynamic characteristics of sorption of adamantane and its functional derivatives on graphitized thermal soot (GTS) modified with polyethylene glycol Carbowax 20M were determined by equilibrium gas chromatography. The resulting thermodynamic characteristics were analyzed and compared with the data measured for adamantanes on the surface of nonmodified GTS and polyethylene glycol deposited on an inert substrate. The solid carbon substrate was shown to affect the character of intermolecular interactions in the GTS-modifier system and the retention of framework compounds under the conditions of gas, liquid, and solid-state chromatography.

Yashkin, S. N.; Ageeva, Yu. A.

2014-04-01

11

Poly(ethylene glycol)-modified Nanocarriers for Tumor-targeted and Intracellular Delivery  

Microsoft Academic Search

The success of anti-cancer therapies largely depends on the ability of the therapeutics to reach their designated cellular\\u000a and intracellular target sites, while minimizing accumulation and action at non-specific sites. Surface modification of nanoparticulate\\u000a carriers with poly(ethylene glycol) (PEG)\\/poly(ethylene oxide) (PEO) has emerged as a strategy to enhance solubility of hydrophobic\\u000a drugs, prolong circulation time, minimize non-specific uptake, and allow

Lilian E. van Vlerken; Tushar K. Vyas; Mansoor M. Amiji

2007-01-01

12

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

PubMed Central

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

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

2015-01-01

13

Polyethylene Glycol Modified, Cross-Linked Starch Coated Iron Oxide Nanoparticles for Enhanced Magnetic Tumor Targeting  

PubMed Central

While successful magnetic tumor targeting of iron oxide nanoparticles has been achieved in a number of models, the rapid blood clearance of magnetically suitable particles by the reticuloendothelial system (RES) limits their availability for targeting. This work aimed to develop a long-circulating magnetic iron oxide nanoparticle (MNP) platform capable of sustained tumor exposure via the circulation and, thus, enhanced magnetic tumor targeting. Aminated, cross-linked starch (DN) and aminosilane (A) coated MNPs were successfully modified with 5 kDa (A5, D5) or 20 kDa (A20, D20) polyethylene glycol (PEG) chains using simple N-Hydroxysuccinimide (NHS) chemistry and characterized. Identical PEG-weight analogues between platforms (A5 & D5, A20 & D20) were similar in size (140–190 nm) and relative PEG labeling (1.5% of surface amines – A5/D5, 0.4% – A20/D20), with all PEG-MNPs possessing magnetization properties suitable for magnetic targeting. Candidate PEG-MNPs were studied in RES simulations in vitro to predict long-circulating character. D5 and D20 performed best showing sustained size stability in cell culture medium at 37°C and 7 (D20) to 10 (D5) fold less uptake in RAW264.7 macrophages when compared to previously targeted, unmodified starch MNPs (D). Observations in vitro were validated in vivo, with D5 (7.29 hr) and D20 (11.75 hr) showing much longer half-lives than D (0.12 hr). Improved plasma stability enhanced tumor MNP exposure 100 (D5) to 150 (D20) fold as measured by plasma AUC0-? Sustained tumor exposure over 24 hours was visually confirmed in a 9L-glioma rat model (12 mg Fe/kg) using magnetic resonance imaging (MRI). Findings indicate that both D5 and D20 are promising MNP platforms for enhanced magnetic tumor targeting, warranting further study in tumor models. PMID:21176955

Cole, Adam J.; David, Allan E.; Wang, Jianxin; Galbán, Craig J.; Hill, Hannah L.; Yang, Victor C.

2010-01-01

14

Sites of modification of hemospan, a poly(ethylene glycol)-modified human hemoglobin for use as an oxygen therapeutic.  

PubMed

Hemospan is an acellular hemoglobin-based oxygen therapeutic in clinical trials in Europe and the United States. The product is prepared by site-specific conjugation of maleimide-activated poly(ethylene) glycol (PEG, MW approximately 5500) to human oxyhemoglobin through maleimidation reactions either (1) directly to reactive Cys thiols or (2) at surface Lys groups following thiolation using 2-iminothiolane. The thiolation/maleimidation reactions lead to the addition of approximately 8 PEGs per hemoglobin tetramer. Identification of PEG modified globins by SDS-PAGE and MALDI-TOF reveals a small percentage of protein migrating at the position for unmodified globin chains and the remaining as separate bands representing globin chains conjugated with 1 to 4 PEGs per chain. Identification of PEG modification sites on individual alpha and beta globins was made using reverse-phase HPLC, showing a series of alpha globins conjugated with 0 to 3 PEGs and a series of beta globins conjugated with 0 to 4 PEGs per globin. Mass analysis of tryptic peptides from hemoglobin thiolated and maleimidated with N-ethyl maleimide showed the same potential sites of modification regardless of thiolation reaction ratio, with seven sites identified on beta globins at beta8, beta17, beta59, beta66, beta93, beta95, and beta132 and three sites identified on alpha globins at alpha7, alpha16, and alpha40. PMID:18837531

Vandegriff, Kim D; Malavalli, Ashok; Mkrtchyan, Gnel M; Spann, Stephanie N; Baker, Dale A; Winslow, Robert M

2008-11-19

15

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

PubMed Central

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

2014-01-01

16

Comparative studies of irinotecan-loaded polyethylene glycol-modified liposomes prepared using different PEG-modification methods.  

PubMed

Recently, a polyethylene glycol (PEG)-modification method for liposomes prepared using pH-gradient method has been proposed. The differences in the pharmacokinetics and the impact on the antitumor effect were examined; however the impact of PEG-lipid molar weight has not been investigated yet. The main purpose of this study is to evaluate the impact of PEG-lipid molar weight against the differences in the pharmacokinetics, the drug-release profile, and the antitumor effect between the proposed PEG-modification method, called the post-modification method, and the conventional PEG-modification method, called the pre-modification method. Various comparative studies were performed using irinotecan as a general model drug. The results showed that PEG-lipid degradation could be markedly inhibited in the post-modification method. Furthermore, prolonged circulation time was observed in the post-modification method. The sustained drug-release was observed in the post-modification method by the results of the drug-releasing test in plasma. Moreover, a higher antitumor effect was observed in the post-modification method. It was also confirmed that the same behaviors were observed in all comparative studies even though the PEG molecular weight was lower. In conclusion, the post-modification method has the potential to be a valuable PEG-modification method that can achieve higher preservation stability of PEG-lipid, prolonged circulation time, and higher antitumor effect with only half the amount of PEG-lipid as compared to the pre-modification method. Furthermore, it was demonstrated that PEG(5000)-lipid would be more desirable than PEG(2000)-lipid since it requires much smaller amount of PEG-lipid to demonstrate the same performances. PMID:22828450

Yoshino, Keisuke; Nakamura, Koji; Terajima, Yoko; Kurita, Akinobu; Matsuzaki, Takeshi; Yamashita, Keiko; Isozaki, Masashi; Kasukawa, Hiroaki

2012-11-01

17

Self-aggregated nanoparticles from methoxy poly(ethylene glycol)-modified chitosan: synthesis; characterization; aggregation and methotrexate release in vitro.  

PubMed

Methoxy poly(ethylene glycol)-grafted-chitosan (mPEG-g-CS) conjugates were synthesized by formaldehyde linking method and characterized by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance ((1)H-NMR). The degree of substitution (DS) of methoxy poly (ethylene glycol) (mPEG) in the mPEG-g-CS molecules determined by (1)H-NMR ranged from 19% to 42%. The critical aggregation concentration (CAC) was determined by fluorescence spectroscopy using pyrene as fluorescence probe and its value was 0.07 mg/mL in water. mPEG-g-CS formed monodisperse self-aggregated nanoparticles with a roughly spherical shape and a mean diameter of 261.9 nm were prepared by the dialysis method. mPEG-g-CS self-aggregated nanoparticles were used as carriers of poorly water-soluble anticancer drug methotrexate (MTX). MTX was physically entrapped inside mPEG-g-CS self-aggregated nanoparticles by dialysis method and the characteristics of MTX-loaded mPEG-g-CS self-aggregated nanoparticles were analyzed using dynamic laser light scattering (DLLS), transmission electron microscopy (TEM). Moreover, in vitro release behavior of MTX was also investigated and the results showed that MTX was continuously released more than 50% in 48 h. PMID:17869489

Yang, Xindu; Zhang, Qiqing; Wang, Yinsong; Chen, Han; Zhang, Huizhu; Gao, Fuping; Liu, Lingrong

2008-02-15

18

Whey Protein Fractionation with Polyethylene Glycol  

Microsoft Academic Search

Fractionation of whey proteins with polyethylene glycols 1,450, 6,000, and 20,000 was studied at pH 4.6, 6.0, and 7.0 and at 4 and 23 C. Whey proteins were most susceptible to precipitation by polyethylene glycols at pH 4.6 and most resistant to precipitation at pH 6.0. At pH 4.6, 6,000 and 20,000 were more effective precipitation agents than 1,450. Temperature

R. L. Richter; C. V. Morr; G. A. Reineccius

1974-01-01

19

Poly(ethylene glycol)-modified PAMAM-Fe3O4-doxorubicin triads with the potential for improved therapeutic efficacy: generation-dependent increased drug loading and retention at neutral pH and increased release at acidic pH.  

PubMed

Polyamidoamine (PAMAM) dendrimer-coated magnetic nanoparticles are a promising drug-delivery system that can enhance the therapeutic effects of chemotherapy drugs, such as doxorubicin (DOX), with minimized side effects. This work explores the optimization of the potential therapeutic efficiency of PAMAM-Fe3O4-DOX triads. Different generations (G3, G5, and G6) of PAMAMs were synthesized and modified with poly(ethylene glycol) (PEG) and then used to encapsulate glutamic acid-modified Fe3O4 nanoparticles. The Fe3O4-dendrimer carriers (Fe3O4-DGx where x = the generation 3, 5, or 6 of dendrimers) were electrostatically conjugated with drug DOX. The loading and releasing efficiencies of DOX increased with the PAMAM generation from 3 to 6. The loading efficiencies of DOX molecules were 87, 93, and 96% for generations 3, 5, and 6, respectively. At pH 5, the DOX release efficiencies within 24 h were approximately 60, 68, and 80% for generations 3, 5, and 6, respectively. At pH 7.4, the DOX releasing efficiency was as low as ? 15%. Compared to the negative control, the PAMAM-Fe3O4-DOX triads showed only mild toxicity against human cervical adenocarcinoma cell line HeLa at pH 7.4, which indicated that DOX can be fairly benignly carried and sparingly released until PAMAM-Fe3O4-DOX is taken up into the cell. PMID:24446987

Nigam, Saumya; Chandra, Sudeshna; Newgreen, Donald F; Bahadur, Dhirendra; Chen, Qizhi

2014-02-01

20

Enzymatic catalysis in organic solvents: Polyethylene glycol modified hydrogenase retains sulfhydrogenase activity in toluene  

SciTech Connect

Naturally occurring enzymes may be modified by covalently attaching hydrophobic groups that render the enzyme soluble and active in organic solvents, and have the potential to greatly expand applications of enzymatic catalysis. The reduction of elemental sulfur to hydrogen sulfide by a hydrogenase isolated from Pyrococcus furiosus has been investigated as a model system for organic biocatalysis. While the native hydrogenase catalyzed the reduction of sulfur to H{sub 2}S in aqueous solution, no activity was observed when the aqueous solvent was replaced with anhydrous toluene. Hydrogenase modified with PEG p-nitrophenyl carbonate demonstrated its native biocatalytic ability in toluene when the reducing dye, benzyl viologen, was also present. Neither benzyl viologen or PEG p-nitrophenyl carbonate alone demonstrated reducing capability. PEG modified cellulase and benzyl viologen were also incapable of reducing sulfur to H{sub 2}S, indicating that the enzyme itself, and not the modification procedure, is responsible for the conversion in the nonpolar organic solvent. Sulfide production in toluene was tenfold higher than that produced in an aqueous system with equal enzyme activity, demonstrating the advantages of organic biocatalysis. Applications of bioprocessing in nonaqueous media are expected to provide significant advances in the areas of fossil fuels, renewable feedstocks, organic synthesis, and environmental control technology.

Woodward, C.A.; Kaufman, E.N. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States)

1996-11-05

21

Effects of polyethylene glycol on protein interactions  

NASA Astrophysics Data System (ADS)

The interactions between globular proteins in the presence of poly (ethylene glycol) (PEG) are probed through the measurement of the protein solution second virial coefficient (B2). The solution properties of PEG are characterized for four molecular weights (400, 1000, 6000, and 12 000), providing an opportunity for quantitative comparison of measurements and theoretical predictions of B2. PEG displays a buffer and molecular weight-dependent lower critical solution temperature. As the polymer solution approaches phase separation, the consequences of depletion attractions increase significantly. For lysozyme and bovine serum albumin in sulfate buffers with PEG, B2 is not well described by standard depletion models. This failure is accentuated in acetate buffers where B2 is a nonmonotonic function of polymer concentration. The attractive minima in B2 are closely associated with the proximity of the heating-induced phase separation of aqueous PEG solutions. The experimental data for both proteins in the presence of PEG are well captured by the thermal polymer reference interaction site model for depletion interactions where the polymer density fluctuation correlation length is treated as a function of temperature, polymer concentration, and molecular weight.

Kulkarni, Amit M.; Chatterjee, Avik P.; Schweizer, Kenneth S.; Zukoski, Charles F.

2000-12-01

22

Effect of polyethylene glycol on the liquidliquid phase transition in aqueous protein solutions  

E-print Network

Effect of polyethylene glycol on the liquid­liquid phase transition in aqueous protein solutions, 2002 We have studied the effect of polyethylene glycol (PEG) on the liquid­liquid phase separation. PEG ternary mixtures solubility partitioning Polyethylene glycol (PEG) is a hydrophilic nonionic

Annunziata, Onofrio

23

Determination of six polyynes in Oplopanax horridus and Oplopanax elatus using polyethylene glycol modified reversed migration microemulsion electrokinetic chromatography.  

PubMed

A PEG-modified reversed migration MEEKC method was developed for simultaneous determination of six polyynes, including oplopandiol, falcarindiol, oplopandiol acetate, (11S, 16S, 9Z)-9,17-octadecadiene-12,14-diyne-1,11,16-triol,1-acetate, oplopantriol B, and oplopantriol A, in Oplopanax horridus and Oplopanax elatus. The running buffer containing 0.8% v/v ethyl acetate, 3.8% w/v SDS, 6.6% v/v n-butanol in 20 mM phosphate buffer (pH 2.5), followed by mixing with propan-2-ol at 30% v/v and PEG-1000 at 15% w/v, was applied in the analysis. The proposed method was successfully applied to determine the six polyynes in five samples of Oplopanax horridus and one of O. elatus. The result showed that the types and amounts of polyynes present were obviously different when comparing the two herbs. Besides, the developed PEG-modified reversed MEEKC method might be suitable for the analysis of hydrophobic analytes in herbal medicines. PMID:25070635

Yang, Zhong-mei; Zhao, Jing; Lao, Ka-meng; Chen, Xiao-jia; Leong, Fong; Wang, Chong-Zhi; Yuan, Chun-Su; Li, Shao-ping

2014-10-01

24

Interfacial Protein-Protein Associations  

PubMed Central

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

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

2014-01-01

25

Mode of lysozyme protein adsorption at end-tethered polyethylene oxide brushes on gold surfaces determined by neutron reflectivity.  

PubMed

The mode of lysozyme protein adsorption at end-tethered thiol-terminated polyethylene oxide brushes grafted upon gold was determined in situ by neutron reflectivity using the INTER instrument at target station 2, ISIS, RAL, UK. It was found that the most probable position of protein adsorption at these weakly protein resistive brushes was at the gold-brush interface in the so-called primary protein position. PMID:25743024

Taylor, Warren; Ebbens, Stephen; Skoda, Maximillian W A; Webster, John R P; Jones, Richard A L

2015-03-01

26

Controlling microencapsulation and release of micronized proteins using poly(ethylene glycol) and electrospraying.  

PubMed

The fabrication of tailored microparticles for delivery of therapeutics is a challenge relying upon a complex interplay between processing parameters and materials properties. The emerging use of electrospraying allows better tailoring of particle morphologies and sizes than current techniques, critical to reproducible release profiles. While dry encapsulation of proteins is essential for the release of active therapeutics from microparticles, it is currently uncharacterized in electrospraying. To this end, poly(ethylene glycol) (PEG) was assessed as a micronizing and solubilizing agent for dry protein encapsulation and release from electrosprayed particles made from polycaprolactone (PCL). The physical effect of PEG in protein-loaded poly(lactic-co-glycolic acid) (PLGA) particles was also studied, for comparison. The addition of 5-15 wt% PEG 6 kDa or 35 kDa resulted in reduced PCL particle sizes and broadened distributions, which could be improved by tailoring the electrospraying processing parameters, namely by reducing polymer concentration and increasing flow rate. Upon micronization, protein particle size was reduced to the micrometer domain, resulting in homogenous encapsulation in electrosprayed PCL microparticles. Microparticle size distributions were shown to be the most determinant factor for protein release by diffusion and allowed specific control of release patterns. PMID:24657821

Bock, Nathalie; Dargaville, Tim R; Woodruff, Maria A

2014-07-01

27

Adhesive protein expression on endothelial cells after contact in vitro with polyethylene terephthalate coated with pyrolytic carbon  

Microsoft Academic Search

This research aims at evaluating the expression of some adhesive proteins on endothelial cell surface after contact with polyethylene terephthalate coated with pyrolytic carbon (PET + PC). Twenty-two different cultures of human umbilical vein endothelial cells (HUVECs) were put in contact with PET + PC. Both HUVECs grown without the biomaterial and HUVECs incubated with endotoxin were used as control.

E. Cenni; D. Granchi; C. R. Arciola; G. Ciapetti; L. Savarino; S. Stea; D. Cavedagna; A. Di Leo; A. Pizzoferrato

1995-01-01

28

Effects of branching and molecular weight of surface-bound poly(ethylene oxide) on protein rejection  

Microsoft Academic Search

To understand better the origin of protein rejection observed with surface-bound poly(ethylene oxide) (or PEO), we have measured fibrinogen adsorption for a series of linear and branched, low-molecular-weight PEOs bound to solid polystyrene surfaces. The results show that a dependence on molecular weight is found below 1500 g mol for linear PEO. Branched PEOs are less effective at protein rejection

Karin Beroström; Eva Österberg; Krister Holmberg; Allan S. Hoffman; Thomas P. Schuman; Antoni Kozlowski; J. Milton Harris

1995-01-01

29

Site-selective adsorption of protein induced by a metal pattern on a poly(ethylene terephthalate) surface.  

PubMed

A novel technique for inducing site-selective adsorption of protein through constructing metal patterns on flexible poly(ethylene terephthalate) surfaces is presented. The substrates were first modified by vacuum ultraviolet (VUV) irradiation through a photomask to introduce regions with different functional groups. Then the designed metal patterns were constructed on the surfaces of VUV-treated substrates. The surface rearrangement was effectively prevented by constructing silver patterns on poly(ethylene terephthalate) surfaces, thus significantly improving the stability and selectivity of protein adsorption on the surfaces. Moreover, the protein-repulsive layer further reinforced the effect. Finally, protein patterns were successfully obtained. As confirmed by fluorescence microscope, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and static water contact angle measurement, the protein patterns possess both excellent selectivity and high fidelity. Feature size of the protein patterns surrounded by a protein-repulsive layer was exactly the same as that of the photomask. And the grain sizes of silver particles were approximately 50 nm. This work could potentially be used in various fields such as biomedicine, bioelectronic components, and tissue repair and replacement, where selective adsorption of protein is desired. PMID:23856546

Cao, Jiali; Wu, Zhongkui; Li, Shaoying; Tang, Hongxiao; Mei, Qilin

2013-11-01

30

Mechanism of precipitation of proteins by polyethylene glycols. Analysis in terms of excluded volume.  

PubMed

The apparent solubilities of various proteins (14,000 to 670,000 daltons) were measured in the presence of polyethylene glycols (PEGs) of different sizes. All of the solubility curves, determined by measuring the protein concentration in the supernate of centrifuged mixtures, exhibited the characteristic linear dependence of log S (g/liter) on PEG concentration (%, w/v). For human albumin in PEG-4000 at pH 4.5, this linearity extended over a 1,000-fold range of solubility, even though the appearance of the sedimented phase changed from a viscous fluid to a white amorphous solid. The slope, beta, decreased from 0.27 to 0.09 with decreasing Mr of PEG from 20,000 to 400, but was insensitive to changes in solution conditions (pH, T, salts), suggesting the absence of specific chemical interactions between protein and polymer. This conclusion was supported by the observation that concentrations of PEG up to 30% (w/v) had no significant effect on the melting temperature of ribonuclease A. Furthermore, equilibrium dialysis measurements, as well as various spectral measurements, provided no evidence for such interactions. Using a steric exclusion model (Edmond, E., and Ogston, A. G. (1968) Biochem. J. 109, 569-576) and assuming that the chemical potential of the solid phase is constant, beta can be related to interaction coefficients calculated from co-volumes using the equivalent sphere radii of PEG (r2) and protein (r3). Although good agreement was obtained for albumin in PEG-20,000, the predicted dependence of beta on r3 was greater than observed and the predicted dependence of beta on r2 was of opposite direction to that observed. However, the interaction coefficient determined from the equilibrium dialysis measurements of albumin and PEG-1000 agreed with the predicted value. Thus, the exclusion of low concentrations of PEG by albumin can be explained by a simple excluded volume model, whereas the exclusion of protein out of solution by PEG appears to be more complex. PMID:7298647

Atha, D H; Ingham, K C

1981-12-10

31

Strongly Stretched Protein Resistant Poly(ethylene glycol) Brushes Prepared by Grafting-To.  

PubMed

We present a new grafting-to method for resistant "non-fouling" poly(ethylene glycol) brushes, which is based on grafting of polymers with reactive end groups in 0.9 M Na2SO4 at room temperature. The grafting process, the resulting brushes, and the resistance toward biomolecular adsorption are investigated by surface plasmon resonance, quartz crystal microbalance, and atomic force microscopy. We determine both grafting density and thickness independently and use narrow molecular weight distributions which result in well-defined brushes. High density (e.g., 0.4 coils per nm(2) for 10 kDa) and thick (40 nm for 20 kDa) brushes are readily achieved that suppress adsorption from complete serum (10× dilution, exposure for 50 min) by up to 99% on gold (down to 4 ng/cm(2) protein coverage). The brushes outperform oligo(ethylene glycol) monolayers prepared on the same surfaces and analyzed in the same manner. The brush heights are in agreement with calculations based on a simple model similar to the de Gennes "strongly stretched" brush, where the height is proportional to molecular weight. This result has so far generally been considered to be possible only for brushes prepared by grafting-from. Our results are consistent with the theory that the brushes act as kinetic barriers rather than efficient prevention of adsorption at equilibrium. We suggest that the free energy barrier for passing the brush depends on both monomer concentration and thickness. The extraordinary simplicity of the method and good inert properties of the brushes should make our results widely applicable in biointerface science. PMID:25812004

Emilsson, Gustav; Schoch, Rafael L; Feuz, Laurent; Höök, Fredrik; Lim, Roderick Y H; Dahlin, Andreas B

2015-04-15

32

Poly(ethylene oxide) layers grafted to dopamine-melanin anchoring layer: stability and resistance to protein adsorption.  

PubMed

In this study, we propose substrate-independent modification for creating a protein-repellent surface based on dopamine-melanin anchoring layer used for subsequent binding of poly(ethylene oxide) (PEO) from melt. We verified that the dopamine-melanin layer can be formed on literally any substrate and could serve as the anchoring layer for subsequent grafting of PEO chains. Grafting of PEO from melt in a temperature range 70-110 °C produces densely packed PEO layers showing exceptionally low protein adsorption when exposed to the whole blood serum or plasma. The PEO layers prepared from melt at 110 °C retained the protein repellent properties for as long as 10 days after their exposure to physiological-like conditions. The PEO-dopamine-melanin modification represents a simple and universal surface modification method for the preparation of protein repellent surfaces that could serve as a nonfouling background in various applications, such as optical biosensors and tissue engineering. PMID:21823677

Pop-Georgievski, Ognen; Popelka, Št?pán; Houska, Milan; Chvostová, Dagmar; Proks, Vladimír; Rypá?ek, František

2011-09-12

33

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

PubMed

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 approximately <100 nm thickness. Gelation of PEG-octavinylsulfone with amines in either bovine serum albumin (BSA) or PEG-octaamine was monitored by dynamic light scattering (DLS), revealing the presence of microgels before macrogelation. NMR also revealed extremely high end-group conversions prior to macrogelation, consistent with the formation of highly crosslinked microgels and deviation from Flory-Stockmayer theory. Before macrogelation, the reacting solutions were diluted and incubated with nucleophile-functionalized surfaces. Using optical waveguide lightmode spectroscopy (OWLS) and quartz crystal microbalance with dissipation (QCM-D), we identified a highly hydrated, 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

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

2008-12-01

34

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

PubMed Central

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

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

2008-01-01

35

Improving Protein Delivery from Microparticles Using Blends of Poly(DL lactide co-glycolide) and Poly(ethylene oxide)-poly(propylene oxide) Copolymers  

Microsoft Academic Search

Purpose. Microparticles containing ovalbumin as a model for protein drugs were formulated from blends of poly(DL lactide-co-glycolide) and poly(ethylene oxide)-poly(propylene oxide) copolymers (Pluronic). The objectives were to achieve uniform release characteristics and improved protein delivery capacity.

Ming-Kung Yeh; Stanley S. Davis; Allan G. A. Coombes

1996-01-01

36

Parenteral protein delivery systems using biodegradable polyesters of ABA block structure, containing hydrophobic poly(lactide-co-glycolide) A blocks and hydrophilic poly(ethylene oxide) B blocks  

Microsoft Academic Search

Parenteral delivery systems for proteins, based on biodegradable polyesters present significant problems with respect to modulation of release properties. Frequently proteins are more sensitive to environmental factors than peptides, leading to a loss in biological activity. We have investigated the release properties of ABA block copolymers, which contain hydrophilic poly(ethylene oxide) B blocks. Microspheres prepared from these biodegradable polyesters show

T. Kissel; Y. X. Li; C. Volland; S. Görich; R. Koneberg

1996-01-01

37

Grafted poly-(ethylene glycol) on lipid surfaces inhibits protein adsorption and cell adhesion  

Microsoft Academic Search

Monolayers of dipalmitoyl-phosphatidylethanolamine (DPPE) mixing with various mole percentages of distearoyl-phosphatidylethanolamine (DSPE)-conjugated poly-(ethylene glycol) (PEG m.w. 750–5000) were deposited on DPPE-coated glass surfaces by the Langmuir-Blodgett method. Increasing percentages of grafted PEG in these supported lipid surfaces increasingly inhibit the adsorption of bovine serum albumin (BSA), laminin, and fibronectin. Increasing percentages of grafted PEG also inhibit the adhesion of erythrocytes,

Hong Du; Parthapratim Chandaroy; Sek Wen Hui

1997-01-01

38

Microcontact printing and microspotting as methods for direct protein patterning on plasma deposited polyethylene oxide: application to stem cell patterning.  

PubMed

Two methods for protein patterning on antifouling surfaces have been applied to analyze the density and bioactivity of the proteins after deposition. Microcontact printing has been used as a technique to transfer fibronectin through conformal contact, while piezoelectric deposition has been employed as a non-contact technique for producing arrays of fibronectin (FN). Plasma deposited polyethylene oxide-like (PEO-like) films have been used as non-fouling background to achieve the bioadhesive/biorepellent surface contrast. Both patterning methods allow the direct fabrication of protein arrays on a non-fouling substrate, and the subsequent formation of a pattern of stem cells by cell attachment on the arrayed substrates. Microcontact printing produced fully packed homogeneous fibronectin patterns, much denser than microspotted patterns. Both printing and spotting technologies generated functional protein arrays, their bioactivity being primarily modulated by the density of the deposited protein layer. Optimization of the FN parameters used for deposition has lead to the achievement of high-quality microarrays with large population of neural stem cells immobilized in the patterns in serum-free conditions, where cells exhibit a more homogeneous starting population and factors influencing fate decisions can be more easily tracked. The immunorecognition of fibronectin targeted antibodies, as well as the cell density, increase with the protein density up to a saturation point. Over 100 ng/cm² of fibronectin on the surface leads to a decrease in the number of attached cells and a raise of cell spreading. PMID:23404262

Ruiz, Ana; Zychowicz, Marzena; Ceriotti, Laura; Mehn, Dora; Sirghi, Lucel; Rauscher, Hubert; Mannelli, Ilaria; Colpo, Pascal; Buzanska, Leonora; Rossi, François

2013-06-01

39

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

NASA Astrophysics Data System (ADS)

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.

Scott, Evan Alexander

2009-12-01

40

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...

41

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

PubMed

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

Gavira, Jose A; Cera-Manjarres, Andry; Ortiz, Katia; Mendez, Janet; Jimenez-Torres, Jose A; Patiño-Lopez, Luis D; Torres-Lugo, Madeline

2014-07-01

42

Quantitation of free polyethylene glycol in PEGylated protein conjugate by size exclusion HPLC with refractive index (RI) detection.  

PubMed

In this study, size exclusion high performance liquid chromatography was evaluated for its application in separation and quantitation of free polyethylene glycol (PEG) and its PEGylated-protein-conjugate (PEG-conjugate). Although the large mass of the free PEG (2-fold greater than the protein) made separation difficult, chromatographic conditions were identified enabling resolution and quantitation of the free PEG, PEG-conjugate and non-PEGylated protein with Shodex Protein KW803 and KW804 columns in series and refractive index detection. The optimum resolution of 1.7 and 2.0 was achieved for the free PEG and PEG-conjugate as well as the free PEG and non-PEGylated protein using 20mM HEPES buffer at pH 6.5. Under this condition, the plot of log(10)MW of all the pertinent analytes against retention time showed a linear relationship with a correlation coefficient of 1. Limited assay performance evaluation demonstrated that the method was linear in the concentration range of 10 to 250 microg/mL of free PEG with correlation coefficients of > or = 0.99. When free PEG in this concentration range was spiked into PEG-conjugate samples at 1mg/mL, the recovery was in the range of 78%-120%. Detection and quantitation limits were determined to be, respectively, 10 and 25 microg/mL for free PEG. The R.S.D. for intra- and inter-day precision was 0.09% or less for retention time measurements and 2.9% or less for area count measurements. Robustness testing was performed by deliberately deviating +/-0.2 pH units away from the desired pH as well as by increasing the flow rate. These deviations resulted in no significant impact on area percent distribution of all species. However, separation was found to be sensitive to high ionic strength and buffer species. PMID:19019609

Li, Ning; Ziegemeier, Daisy; Bass, Laura; Wang, Wei

2008-12-15

43

Morphology and Properties of Deoiled Cake (DOC) Isolated Mixed Proteins and Low-Density Polyethylene Blends  

Microsoft Academic Search

Proteins were isolated from deoiled cakes (DOC) of soybean, castor and rapeseed. The isolated proteins were then blended with LDPE in different wt. ratios, using PEG400 as a plasticizer. The morphology of the blends was evaluated by using a scanning electron microscope (SEM). Homogeneous blends were obtained and analyzed for various mechanical properties such as tensile strength, impact strength, hardness

Darshan Patel; S. D. Toliwal; J. V. Patel

2012-01-01

44

Hydrogels based on poly(ethylene oxide) and poly(tetramethylene oxide) or poly(dimethyl siloxane): synthesis, characterization, in vitro protein adsorption and platelet adhesion  

Microsoft Academic Search

In vitro protein adsorption, platelet adhesion and activation on new hydrogel surfaces, composed of poly(ethylene oxide) (PEO) and poly(tetramethylene oxide) (PTMO) or poly(dimethyl siloxane) (PDMS), were investigated. By varying PEO length (MW=2000 or 3400), hydrophobic components (PTMO or PDMS) or polymer topology (block or graft copolymers), various physical hydrogels were produced. Their structures were verified by 1HNMR and ATR-IR and

Jae Hyung Park; You Han Bae

2002-01-01

45

PROTEIN SEPARATION BY CROSS-AXIS COIL PLANET CENTRIFUGE WITH TWO DIFFERENT POSITIONS OF ECCENTRIC COIL ASSEMBLIES USING POLYETHYLENE GLYCOL-DEXTRAN SOLVENT SYSTEM  

Microsoft Academic Search

Countercurrent chromatography (CCC) of proteins was performed by the cross-axis coil planet centrifuge (cross-axis CPC) using polyethylene glycol (PEG) - dextran biphasic systems. A pair of eccentric coil assemblies was mounted at two different positions (off-center and central) on the rotary frame. The best separation was obtained from a two-phase solvent system composed of 4.0% (w\\/w) PEG 8000 - 5.0%

Kazufusa Shinomiya; Shingo Hirozane; Yozo Kabasawa; Yoichiro Ito

2000-01-01

46

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

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...

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

2014-01-01

47

Accumulation of protein-coated liposomes in an extravascular site: influence of increasing carrier circulation lifetimes.  

PubMed

The primary objective of this work was to test whether increased blood levels and circulation lifetimes result in increased passive targeting of protein-coated liposomal drug carriers. The system used to evaluate this was based on i.v. injection of 100 nm of distearoyl phosphatidylcholine/cholesterol liposomes with covalently bound streptavidin. The circulation lifetime of these liposomes was increased by procedures that involved blockade of liposome uptake by phagocytic cells in the liver and/or the incorporation of a poly(ethylene glycol)-modified phospholipid [poly(ethylene glycol)2000-modified distearoyl phosphatidylethanolamine]. Blockade of liver phagocytic cells with a low predose (2 mg/kg of drug) of liposomal doxorubicin increased the circulation half-life of the streptavidin liposomes from less than 1 hr to greater than 3 hr. A further 2-fold increase in circulating half-life (to approximately 7.5 hr) was achieved by using liposomes with 2 mole % of poly(ethylene glycol)2000-modified phosphatidylethanolamine. In combination with RES blockade, the circulation lifetimes of poly(ethylene glycol)phosphatidylethanolamine containing streptavidin liposomes could be increased to greater than 12 hr. The ability of these liposomes to move from the plasma compartment to an extravascular compartment was measured by using the peritoneal cavity as a convenient, accessible, extravascular site. The tendency for liposomes to accumulate in this site was not, however, clearly dependent on circulating blood levels. Comparable levels of liposomes in the peritoneal cavity were achieved when using systems that exhibited significantly different circulation lifetimes. PMID:8531079

Longman, S A; Tardi, P G; Parr, M J; Choi, L; Cullis, P R; Bally, M B

1995-12-01

48

Graft copolymer-templated mesoporous TiO(2) films micropatterned with poly(ethylene glycol) hydrogel: novel platform for highly sensitive protein microarrays.  

PubMed

In this study, we describe the use of organized mesoporous titanium oxide (TiO(2)) films as three-dimensional templates for protein microarrays with enhanced protein loading capacity and detection sensitivity. Multilayered mesoporous TiO(2) films with high porosity and good connectivity were synthesized using a graft copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly(oxyethylene methacrylate) (POEM) side chains as a structure-directing template. The average pore size and thickness of the TiO(2) films were 50-70 nm and 1.5 ?m, respectively. Proteins were covalently immobilized onto mesoporous TiO(2) film via 3-aminopropyltriethoxysilane (APTES), and protein loading onto TiO(2) films was about four times greater than on planar glass substrates, which consequently improved the protein activity. Micropatterned mesoporous TiO(2) substrates were prepared by fabricating poly(ethylene glycol) (PEG) hydrogel microstructures on TiO(2) films using photolithography. Because of non-adhesiveness of PEG hydrogel towards proteins, proteins were selectively immobilized onto surface-modified mesoporous TiO(2) region, creating protein microarray. Specific binding assay between streptavidin/biotin and between PSA/anti-PSA demonstrated that the mesoporous TiO(2)-based protein microarrays yielded higher fluorescence signals and were more sensitive with lower detection limits than microarrays based on planar glass slides. PMID:21291203

Son, Kyung Jin; Ahn, Sung Hoon; Kim, Jong Hak; Koh, Won-Gun

2011-02-01

49

POLYETHYLENE ENCAPSULATION.  

SciTech Connect

Polyethylene microencapsulation physically homogenizes and incorporates mixed waste particles within a molten polymer matrix, forming a solidified final waste form upon cooling. Each individual particle of waste is embedded within the polymer block and is surrounded by a durable, leach-resistant coating. The process has been successfully applied for the treatment of a broad range of mixed wastes, including evaporator concentrate salts, soil, sludges, incinerator ash, off-gas blowdown solutions, decontamination solutions, molten salt oxidation process residuals, ion exchange resins, granular activated carbon, shredded dry active waste, spill clean-up residuals, depleted uranium powders, and failed grout waste forms. For waste streams containing high concentrations of soluble toxic metal contaminants, additives can be used to further reduce leachability, thus improving waste loadings while meeting or exceeding regulatory disposal criteria. In this configuration, contaminants are both chemically stabilized and physically solidified, making the process a true stabilization/solidification (S/S) technology. Unlike conventional hydraulic cement grouts or thermosetting polymers, thermoplastic polymers such as polyethylene require no chemical. reaction for solidification. Thus, a stable, solid, final waste form product is assured on cooling. Variations in waste chemistry over time do not affect processing parameters and do not require reformulation of the recipe. Incorporation of waste particles within the polymer matrix serves as an aggregate and improves the mechanical strength and integrity of the waste form. The compressive strength of polyethylene microencapsulated waste forms varies based on the type and quantity of waste encapsulated, but is typically between 7 and 17.2 MPa (1000 and 2500 psi), well above the minimum strength of 0.4 MPa (160 psi) recommended by the U.S. Nuclear Regulatory Commission (NRC) for low-level radioactive waste forms in support of 10 CFR 61 (NRC, 1991; 1983) Because polyethylene is a relatively new material, it is difficult to predict its long-term durability. However, prior to scale-up of the microencapsulation process, a study was conducted to evaluate potential degradation mechanisms. The study examined potential effects on mechanical integrity from exposure to chemicals and solvents, thermal cycling, saturated environments, microbial attack, and high gamma-radiation fields (Kalb et al., 1991). At ambient temperatures, polyethylene is relatively inert to most chemicals, including organic solvents, acids, and alkaline solutions. Exposure to changes in temperature or saturated soil conditions have been shown to degrade the mechanical integrity of some waste forms, but had little or no measurable impact on polyethylene waste forms. Low-density polyethylene is not susceptible to growth of microbial organisms, a fact that is evidenced by the lack of plastics decomposition in municipal waste landfills. When exposed to gamma-radiation at total doses of up to lo8 rad, additional cross-linking of the polymer occurs, resulting in increased strength and lower leachability.

KALB, P.

2001-08-22

50

Plasma-induced graft-polymerization of polyethylene glycol acrylate on polypropylene films: chemical characterization and evaluation of the protein adsorption.  

PubMed

This work deals with the optimization of argon plasma-induced graft-polymerization of polyethylene glycol acrylate (PEGA) on polypropylene (PP) films in order to obtain surfaces with a reduced protein adsorption for possible biomedical applications. To this end, we examined the protein adsorption on the treated and untreated surfaces. The graft-polymerization process consisted of four steps: (a) plasma pre-activation of the PP substrates; (b) immersion in a PEGA solution; (c) argon plasma-induced graft-polymerization; (d) washing and drying of the samples. The efficiency of these processes was evaluated in terms of the amount of grafted polymer, coverage uniformity and substrates wettability. The process was monitored by contact angle measurements, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS) and atomic force microscopy (AFM) analyses. The stability of the obtained thin films was evaluated in water and in Phosphate Buffer Saline (PBS) at 37 degrees C. The adsorption of fibrinogen and green fluorescent protein (GFP)--taken as model proteins--on the differently prepared surfaces was evaluated through a fluorescence approach using laser scanning confocal microscopy with photon counting detection. After plasma treatments of short duration, the protein adsorption decreases by about 60-70% with respect to that of the untreated film, while long plasma exposure resulted in a higher protein adsorption, due to damaging of the grafted polymer. PMID:19822326

Zanini, Stefano; Riccardi, Claudia; Grimoldi, Elisa; Colombo, Claudia; Villa, Anna Maria; Natalello, Antonino; Gatti-Lafranconi, Pietro; Lotti, Marina; Doglia, Silvia Maria

2010-01-01

51

Polyethylene Glycol 3350  

MedlinePLUS

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

52

Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.  

PubMed

Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P < 0.05) in abundance in at least one germination treatment. Nineteen proteins increasing and one protein decreasing in abundance during germination had higher abundance in germinated 15°C, 15°C after imbibition at 25°C for 48 h, and 25°C in KNO3 seeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

2015-04-01

53

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

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.

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

2014-11-19

54

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

PubMed

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

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

2014-10-01

55

‘Stealth’ corona-core nanoparticles surface modified by polyethylene glycol (PEG): influences of the corona (PEG chain length and surface density) and of the core composition on phagocytic uptake and plasma protein adsorption  

Microsoft Academic Search

Nanoparticles possessing poly(ethylene glycol) (PEG) chains on their surface have been described as blood persistent drug delivery system with potential applications for intravenous drug administration. Considering the importance of protein interactions with injected colloidal dug carriers with regard to their in vivo fate, we analysed plasma protein adsorption onto biodegradable PEG-coated poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA) and poly(?-caprolactone) (PCL)

R Gref; M Lück; P Quellec; M Marchand; E Dellacherie; S Harnisch; T Blunk; R. H Müller

2000-01-01

56

Two novel class II hydrophobins from Trichoderma spp. stimulate enzymatic hydrolysis of poly(ethylene terephthalate) when expressed as fusion proteins.  

PubMed

Poly(ethylene terephthalate) (PET) can be functionalized and/or recycled via hydrolysis by microbial cutinases. The rate of hydrolysis is however low. Here, we tested whether hydrophobins (HFBs), small secreted fungal proteins containing eight positionally conserved cysteine residues, are able to enhance the rate of enzymatic hydrolysis of PET. Species of the fungal genus Trichoderma have the most proliferated arsenal of class II hydrophobin-encoding genes among fungi. To this end, we studied two novel class II HFBs (HFB4 and HFB7) of Trichoderma. HFB4 and HFB7, produced in Escherichia coli as fusions to the C terminus of glutathione S-transferase, exhibited subtle structural differences reflected in hydrophobicity plots that correlated with unequal hydrophobicity and hydrophily, respectively, of particular amino acid residues. Both proteins exhibited a dosage-dependent stimulation effect on PET hydrolysis by cutinase from Humicola insolens, with HFB4 displaying an adsorption isotherm-like behavior, whereas HFB7 was active only at very low concentrations and was inhibitory at higher concentrations. We conclude that class II HFBs can stimulate the activity of cutinases on PET, but individual HFBs can display different properties. The present findings suggest that hydrophobins can be used in the enzymatic hydrolysis of aromatic-aliphatic polyesters such as PET. PMID:23645195

Espino-Rammer, Liliana; Ribitsch, Doris; Przylucka, Agnieszka; Marold, Annemarie; Greimel, Katrin J; Herrero Acero, Enrique; Guebitz, Georg M; Kubicek, Christian P; Druzhinina, Irina S

2013-07-01

57

Two Novel Class II Hydrophobins from Trichoderma spp. Stimulate Enzymatic Hydrolysis of Poly(Ethylene Terephthalate) when Expressed as Fusion Proteins  

PubMed Central

Poly(ethylene terephthalate) (PET) can be functionalized and/or recycled via hydrolysis by microbial cutinases. The rate of hydrolysis is however low. Here, we tested whether hydrophobins (HFBs), small secreted fungal proteins containing eight positionally conserved cysteine residues, are able to enhance the rate of enzymatic hydrolysis of PET. Species of the fungal genus Trichoderma have the most proliferated arsenal of class II hydrophobin-encoding genes among fungi. To this end, we studied two novel class II HFBs (HFB4 and HFB7) of Trichoderma. HFB4 and HFB7, produced in Escherichia coli as fusions to the C terminus of glutathione S-transferase, exhibited subtle structural differences reflected in hydrophobicity plots that correlated with unequal hydrophobicity and hydrophily, respectively, of particular amino acid residues. Both proteins exhibited a dosage-dependent stimulation effect on PET hydrolysis by cutinase from Humicola insolens, with HFB4 displaying an adsorption isotherm-like behavior, whereas HFB7 was active only at very low concentrations and was inhibitory at higher concentrations. We conclude that class II HFBs can stimulate the activity of cutinases on PET, but individual HFBs can display different properties. The present findings suggest that hydrophobins can be used in the enzymatic hydrolysis of aromatic-aliphatic polyesters such as PET. PMID:23645195

Espino-Rammer, Liliana; Ribitsch, Doris; Przylucka, Agnieszka; Marold, Annemarie; Greimel, Katrin J.; Herrero Acero, Enrique; Guebitz, Georg M.; Kubicek, Christian P.

2013-01-01

58

Specific Adsorption of Histidine-Tagged Proteins on Silica Surfaces Modified with Ni2+:NTA-Derivatized Poly(Ethylene Glycol)  

PubMed Central

Silica surfaces modified with nitrilotriacetic acid (NTA)-polyethylene glycol (PEG) derivatives were used for immobilizing hexahistidine-tagged green fluorescent oprotein (his6-GFP), biotin/streptavidin-AlexaFluor555 (his6-biotin/SA-AF) and gramicidin A-containing vesicles (his6-gA). Three types of surface-reactive PEG derivatives—NTA-PEG3400-Si(OMe)3, NTA-PEG3400-vinylsulfone, and mPEG5000-Si(OMe)3 (control)—were grafted onto silica and tested for their ability to capture his6-tag species via his6:Ni2+:NTA chelation. The composition and thicknesses of the PEG-modified surfaces were characterized using x-ray photoelectron spectroscopy, contact angle, and ellipsometry. Protein capture efficiencies of the NTA-PEG-grafted surfaces were evaluated by measuring fluorescence intensities of these surfaces after exposure to his6-tag species. XPS and ellipsometry data indicate that surface adsorption occurs via specific interactions between the his6-tag and the Ni2+:NTA-PEG-grafted surface. Protein immobilization was most effective for NTA-PEG3400-Si(OMe)3-modified surfaces, with maximal areal densities achieved at 45 pmol/cm2 for his6-GFP and 95 fmol/cm2 for his6-biotin/SA-AF. Lipid vesicles containing his6-gA in a 1:375 gA:lipid ratio could also be immobilized on Ni2+:NTA-PEG3400-Si(OMe)3-modified surfaces at 0.5 mM total lipid. Our results suggest that NTA-PEG-Si(OMe)3 conjugates may be useful tools for immobilizing his6-tag proteins on solid surfaces to produce protein-functionalized surfaces. PMID:17444666

Kang, Eunah; Park, Jin-won; McClellan, Scott; Kim, Jong-Mok; Holland, David; Lee, Gil U.; Franses, Elias; Park, Kinam; Thompson, David H.

2008-01-01

59

Use of site-directed mutagenesis to enhance the epitope-shielding effect of covalent modification of proteins with polyethylene glycol.  

PubMed Central

Modification by covalent attachment of polyethylene glycol (PEG) can reduce the immunogenicity and prolong the circulating life of proteins, but the utility of this approach for any protein is restricted by the number and distribution of PEG attachment sites (e.g., epsilon-amino groups of lysine residues). We have developed a strategy for introducing additional sites for PEG attachment by using site-directed mutagenesis to selectively replace arginine with lysine codons and tested it with purine nucleoside phosphorylase (PNP) from Escherichia coli, an extremely stable but immunogenic enzyme, that could potentially be used to treat an inherited deficiency of PNP. A triple mutant, RK3, possessing three Arg----Lys substitutions was constructed that increased the number of lysines per PNP subunit from 14 to 17, providing an additional 18 potential PEG attachment sites per hexameric enzyme molecule. The wild-type and RK3 enzymes had similar catalytic activity, antigenicity, and immunogenicity. After PEG modification, both enzymes retained catalytic activity, the plasma half-life of both enzymes in mice increased from approximately 4 hr to 4 days, and the binding of both enzymes by antisera raised against each unmodified enzyme was markedly diminished. However, antibody raised against wild-type PEG-PNP did not bind the PEG-RK3 enzyme. PEG-RK3 PNP was also substantially less immunogenic than wild-type PEG-PNP. Accelerated antibody-mediated clearance of PEG-PNP occurred in 2 of 12 mice treated with PEG-RK3 PNP, compared with 10 of 16 mice treated with the modified wild-type enzyme. This combined use of directed mutagenesis and PEG modification is aimed at permitting the widest choice of proteins, including products of genetic and chemical "engineering," to be used for therapy of inherited and acquired disorders. PMID:1714590

Hershfield, M S; Chaffee, S; Koro-Johnson, L; Mary, A; Smith, A A; Short, S A

1991-01-01

60

A functionalized poly(ethylene glycol)-based bioassay surface chemistry that facilitates bio-immobilization and inhibits non-specific protein, bacterial, and mammalian cell adhesion  

PubMed Central

This paper describes a new bioassay surface chemistry that effectively inhibits non-specific biomolecular and cell binding interactions, while providing a capacity for specific immobilization of desired biomolecules. Poly(ethylene glycol) (PEG) as the primary component in nonfouling film chemistry is well-established, but the multicomponent formulation described here is unique in that it (1) is applied in a single, reproducible, solution-based coating step; (2) can be applied to diverse substrate materials without the use of special primers; and (3) is readily functionalized to provide specific attachment chemistries. Surface analysis data are presented, detailing surface roughness, polymer film thickness, and film chemistry. Protein non-specific binding assays demonstrate significant inhibition of serum, fibrinogen, and lysozyme adsorption to coated glass, indium tin oxide, and tissue culture polystyrene dishes. Inhibition of S. aureus and K. pneumoniae microbial adhesion in a microfluidic flow cell, and inhibition of fibroblast cell adhesion from serum-based cell culture is shown. Effective functionalization of the coating is demonstrated by directing fibroblast adhesion to polymer surfaces activated with an RGD peptide. Batch-to-batch reproducibility data are included. The in situ cross-linked PEG-based coating chemistry is unique in its formulation, and its surface properties are attractive for a broad range of in vitro bioassay applications. PMID:18815622

Harbers, Gregory M.; Emoto, Kazunori; Greef, Charles; Metzger, Steven W.; Woodward, Heather N.; Mascali, James J.; Grainger, David W.; Lochhead, Michael J.

2008-01-01

61

Reduction of protein adsorption and macrophage and astrocyte adhesion on ventricular catheters by polyethylene glycol and N-acetyl-L-cysteine.  

PubMed

Cellular obstruction of poly(dimethyl)siloxane (PDMS) catheters is one of the most prevalent causes of shunt failure in the treatment of hydrocephalus. By modifying PDMS using short- and long-chain mono-functional polyethylene glycol (PEG604 and PEG5K, respectively) and N-acetyl-L-cysteine via adsorption and covalent binding (NAC and NAC/EDC/NHS, respectively), we increased surface wettability. We hypothesized that these surface modifications would inhibit protein adsorption and decrease host macrophage and astrocyte adhesion. Tested in a bioreactor set to mimic physiological flow, all modified surfaces significantly decreased albumin adsorption compared with PDMS (p < 0.05) except for PEG604-modified PDMS (p = 0.14). All four modification strategies significantly reduced (p < 0.01) fibronectin adsorption. PEG604, PEG5K, NAC, and NAC/EDC/NHS reduced the average level of macrophage adhesion by 53%, 63%, 40%, and 58% (p <.0.05 except when comparing PDMS with NAC) and astrocyte adhesion by 47%, 83%, 91%, and 72% (p < 0.05 except when comparing PDMS with PEG604), respectively. Combined with saline soak results which suggest that the surface wettability is stable over 30 days for each modification, our results are consistent with the hypothesis that these modifications decrease cell adhesion on catheters in vitro for the treatment of hydrocephalus. PMID:21630435

Harris, Carolyn A; Resau, James H; Hudson, Eric A; West, Richard A; Moon, Candice; Black, Andrew D; McAllister, James P

2011-09-01

62

Functional study of antibodies against a fibrogenin-binding protein in Staphylococcus epidermidis adherence to polyethylene catheters.  

PubMed

Staphylococcus epidermidis is an important pathogen in foreign body-associated infections. In a previous study, we showed that a surface-located fibrinogen-binding protein, termed Fbe, from S. epidermidis mediated the bacterial adherence to fibrinogen-coated surfaces in vitro. In the present study, we demonstrate that antibodies against Fbe can block adherence of S. epidermidis to fibrinogen-coated catheters, subcutaneously implanted catheters from rats, and peripheral venous catheters from human patients. PMID:11398109

Pei, L; Flock, J I

2001-07-01

63

Polyetheylenimine-polyplexes of Spiegelmer NOX-A50 directed against intracellular high mobility group protein A1 (HMGA1) reduce tumor growth in vivo.  

PubMed

High mobility group A1 (HMGA1) proteins belong to a group of architectural transcription factors that are overexpressed in a range of human malignancies, including pancreatic adenocarcinoma. They promote anchorage-independent growth and epithelial-mesenchymal transition and are therefore suggested as potential therapeutic targets. Employing in vitro selection techniques against a chosen fragment of HMGA1, we have generated biostable l-RNA oligonucleotides, so-called Spiegelmers, that specifically bind HMGA1b with low nanomolar affinity. We demonstrate that the best binding Spiegelmers, NOX-A50 and NOX-f33, compete HMGA1b from binding to its natural binding partner, AT-rich double-stranded DNA. We describe a formulation method based on polyplex formation with branched polyethylenimine for efficient delivery of polyethylene glycol-modified Spiegelmers and show improved tissue distribution and persistence in mice. In a xenograft mouse study using the pancreatic cancer cell line PSN-1, subcutaneous administration of 2 mg/kg per day NOX-A50 formulated in polyplexes showed an enhanced delivery of NOX-A50 to the tumor and a significant reduction of tumor volume. Our results demonstrate that intracellular targets can be successfully addressed with a Spiegelmer using polyethylenimine-based delivery and underline the importance of HMGA1 as a therapeutic target in pancreatic cancer. PMID:20961861

Maasch, Christian; Vater, Axel; Buchner, Klaus; Purschke, Werner G; Eulberg, Dirk; Vonhoff, Stefan; Klussmann, Sven

2010-12-17

64

Polyetheylenimine-Polyplexes of Spiegelmer NOX-A50 Directed against Intracellular High Mobility Group Protein A1 (HMGA1) Reduce Tumor Growth in Vivo*  

PubMed Central

High mobility group A1 (HMGA1) proteins belong to a group of architectural transcription factors that are overexpressed in a range of human malignancies, including pancreatic adenocarcinoma. They promote anchorage-independent growth and epithelial-mesenchymal transition and are therefore suggested as potential therapeutic targets. Employing in vitro selection techniques against a chosen fragment of HMGA1, we have generated biostable l-RNA oligonucleotides, so-called Spiegelmers, that specifically bind HMGA1b with low nanomolar affinity. We demonstrate that the best binding Spiegelmers, NOX-A50 and NOX-f33, compete HMGA1b from binding to its natural binding partner, AT-rich double-stranded DNA. We describe a formulation method based on polyplex formation with branched polyethylenimine for efficient delivery of polyethylene glycol-modified Spiegelmers and show improved tissue distribution and persistence in mice. In a xenograft mouse study using the pancreatic cancer cell line PSN-1, subcutaneous administration of 2 mg/kg per day NOX-A50 formulated in polyplexes showed an enhanced delivery of NOX-A50 to the tumor and a significant reduction of tumor volume. Our results demonstrate that intracellular targets can be successfully addressed with a Spiegelmer using polyethylenimine-based delivery and underline the importance of HMGA1 as a therapeutic target in pancreatic cancer. PMID:20961861

Maasch, Christian; Vater, Axel; Buchner, Klaus; Purschke, Werner G.; Eulberg, Dirk; Vonhoff, Stefan; Klussmann, Sven

2010-01-01

65

Phase transition behavior, protein adsorption, and cell adhesion resistance of poly(ethylene glycol) cross-linked microgel particles.  

PubMed

Thermoresponsive poly(N-isopropylacrylamide) (pNIPAm) microgel particles cross-linked with various concentrations of PEG diacrylates of 3 different PEG chain lengths were synthesized via free-radical precipitation polymerization in order to investigate the phase transition and protein adsorption behavior as the hydrophilicity of the network is increased. Photon correlation spectroscopy (PCS) reveals that, as the concentration of PEG cross-linker incorporated into the particles is increased, an increase in the temperature and breadth of the phase transition occurs. Qualitative differences in particle density using isopycnic centrifugation confirm that higher PEG concentrations result in denser networks. The efficient incorporation of PEG cross-linker was confirmed with (1)H NMR, and variable temperature NMR studies suggest that, in the deswollen state, the longer PEG cross-links protrude from the dense globular network. This behavior apparently manifests itself as a decrease in nonspecific protein adsorption with increasing PEG length and content. Furthermore, when electrostatically attached to a glass surface, the particles containing the longer chain lengths exhibited enhanced nonfouling behavior and were resistant to cell adhesion in serum-containing media. The excellent performance of these particulate films and the simplicity with which they are assembled suggests that they may be applicable in a wide range of applications where nonfouling coatings are required. PMID:16004442

Nolan, Christine M; Reyes, Catherine D; Debord, Justin D; García, Andrés J; Lyon, L Andrew

2005-01-01

66

Adsorption of peptides and small proteins with control access polymer permeation to affinity binding sites. Part II: Polymer permeation-ion exchange separation adsorbents with polyethylene glycol and strong anion exchange groups.  

PubMed

In chromatographic separations, the most general problem in small biomolecule isolation and purification is that such biomolecules are usually found in extremely low concentrations together with high concentrations of large molecular weight proteins. In the first part of this work, adsorption and size exclusion chromatography (AdSEC) controlled access media, using polyethylene glycol (PEG) as a semi-permeable barrier on a polysaccharide Immobilized Metal Affinity Chromatography (IMAC) matrix was synthesized and used to develop chromatographic adsorbents that preferentially adsorb and separate low molecular weight biomolecules while rejecting large molecular weight proteins. In this second part, we expand the concept of controlled access polymer permeation adsorption (CAPPA) media by grafting polyethylene glycol (PEG) on a high capacity polysaccharide ion exchange (IEX) chromatographic resin where PEG acts as a semi-permeable barrier that preferentially allows the permeation of small molecules while rejecting large ones. The IEX resin bearing quaternary ammonium groups binds permeated biomolecules according to their ion exchange affinity while excluding large biomolecules by the PEG barrier and thus cannot compete for the binding sites. This new AdSEC media was used to study the retention of peptides and proteins covering a wide range of molecular weights from 1 to 150 kDa. The effect of protein molecular weight towards retention by ion exchange was performed using pure protein solutions. Recovery of insulin from insulin-spiked human serum and insulin-spiked human urine was evaluated under polymer controlled permeation conditions. The CAPPA media consisted of agarose beads modified with amino-PEG-methoxy and with trimethyl ammonium groups, having chloride capacities between 20 and 40 ?eq/mL and were effective in rejecting high molecular weight proteins while allowing the preferential adsorption of small proteins and peptides. PMID:22265175

González-Ortega, Omar; Porath, Jerker; Guzmán, Roberto

2012-03-01

67

Chemical characterization of polyethylene resins and polyethylene gas pipe  

SciTech Connect

Three analytical techniques were used in this study to characterize chemically commercial polyethylene pipe samples: carbon-13 nuclear magnetic resonance (/sup 13/C NMR) for looking at branching in the polyethylene, gas chromatography/mass spectrometry (GC/MS) for characterizing some of the low molecular weight components of polyethylene gas pipe, and x-ray diffraction (XRD) for determining the degree of crystallite orientation and crystallite size of the polyethylene within the polyethylene pipe matrix. Results are discussed. 9 figs., 6 tabs.

Raphaelian, L.A.; Ettinger, D.G.

1985-01-01

68

Method for casting polyethylene pipe  

NASA Technical Reports Server (NTRS)

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.

Elam, R. M., Jr.

1973-01-01

69

Achievement of high rates of in vitro synthesis of 1,4-beta-D-glucan: activation by cooperative interaction of the Acetobacter xylinum enzyme system with GTP, polyethylene glycol, and a protein factor.  

PubMed Central

Regulatory properties of a cellulose synthase (UDP-forming)(UDPglucose:1,4-beta-D-glucan 4-beta-D-glucosyltransferase, EC 2.4.1.12) have been demonstrated by using enzyme preparations derived from cells of Acetobacter xylinum. Preparation of a particulate fraction in the presence of 20% (wt/vol) polyethylene glycol-4000 (PEG-4000) yields enzyme with activity 3- to 10-fold higher than that previously reported. The enzyme prepared in this fashion also shows a further marked, specific activation by GTP. The Ka for GTP is 34 microM. Guanosine 5'-[gamma-thio]triphosphate, an analog of GTP, is even more effective than GTP (Ka for guanosine 5'-[gamma-thio]triphosphate = 17 microM). A large number of other nucleotides and nucleotide derivatives were tested with no effect. Enzyme prepared in the absence of PEG-4000 does not respond to GTP because it lacks a protein factor necessary for GTP activation. PEG-4000 promotes the interaction of the protein factor with the enzyme. The factor itself has no synthase activity nor does it stimulate activity of the enzyme in the absence of GTP. In the presence of GTP, protein factor, and PEG-4000, initial rates of enzyme activity 200 times greater than those previously reported can be achieved. Such rates exceed 40% of the in vivo rate of cellulose synthesis from glucose. PMID:6216481

Aloni, Y; Delmer, D P; Benziman, M

1982-01-01

70

Adsorption of peptides and small proteins with control access polymer permeation to affinity binding sites. Part I: Polymer permeation-immobilized metal ion affinity chromatography separation adsorbents with polyethylene glycol and immobilized metal ions.  

PubMed

Despite the many efforts to develop efficient protein purification techniques, the isolation of peptides and small proteins on a larger than analytical scale remains a significant challenge. Recovery of small biomolecules from diluted complex biological mixtures, such as human serum, employing porous adsorbents is a difficult task mainly due to the presence of concentrated large biomolecules that can add undesired effects in the system such as blocking of adsorbent pores, impairing diffusion of small molecules, or competition for adsorption sites. Adsorption and size exclusion chromatography (AdSEC) controlled access media, using polyethylene glycol (PEG) as a semi-permeable barrier on a polysaccharide matrix, have been developed and explored in this work to overcome such effects and to preferentially adsorb small molecules while rejecting large ones. In the first part of this work, adsorption studies were performed with small peptides and proteins from synthetic mixtures using controlled access polymer permeation adsorption (CAPPA) media created by effectively grafting PEG on an immobilized metal affinity chromatography (IMAC) agarose resin, where chelating agents and immobilized metal ions were used as the primary affinity binding sites. Synthetic mixtures consisted of bovine serum albumin (BSA) with small proteins, peptides, amino acids (such as histidine or Val?-Angiotensin III), and small molecules-spiked human serum. The synthesized hybrid adsorbent consisted of agarose beads modified with iminodiacetic (IDA) groups, loaded with immobilized Cu(II) ions, and PEG. These CAPPA media with grafted PEG on the interior and exterior surfaces of the agarose matrix were effective in rejecting high molecular weight proteins. Different PEG grafting densities and PEG of different molecular weight were tested to determine their effect in rejecting and controlling adsorbent permeation properties. Low grafting density of high molecular weight PEG was found to be as effective as high grafting density of low molecular weight PEG in the rejecting properties of the semi-permeable synthesized media. PMID:22281505

González-Ortega, Omar; Porath, Jerker; Guzmán, Roberto

2012-03-01

71

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

PubMed

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

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

2013-11-01

72

Topological Twistons in Crystalline Polyethylene  

E-print Network

We introduce an alternate model to describe twistons in crystalline polyethylene. The model couples torsional and longitudinal degrees of freedom and appears as an extension of a model that describes only the torsional motion. We find exact solutions that describe stable topological twistons, in good agreement with the torsional and longitudinal interactions in polyethylene.

D. Bazeia; E. Ventura

1999-02-09

73

Water treeing in polyethylene cables  

Microsoft Academic Search

Water tree growth in polyethylene cable insulation is discussed. The characteristics of water trees, the effect of aging parameters on water tree growth, and the possible mechanisms of growth are considered, emphasizing vented tree development in polyethylene insulating materials. The morphology of water trees, the characteristics of the tree-infested dielectric cable, and test methods and measures to reduce water treeing

E. F. Steennis; F. H. Kreuger

1990-01-01

74

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

E-print Network

Phase Structure and Properties of Poly(ethylene terephthalate)/High-Density Polyethylene Based.interscience.wiley.com). ABSTRACT: Blends based on recycled high density polyethylene (R-HDPE) and recycled poly(ethylene tereph- thalate) (R-PET) were made through reactive extrusion. The effects of maleated polyethylene (PE

75

Degradable polyethylene: fantasy or reality.  

PubMed

Plastic waste disposal is one of the serious environmental issues being tackled by our society today. Polyethylene, particularly in packaging films, has received criticism as it tends to accumulate over a period of time, leaving behind an undesirable visual footprint. Degradable polyethylene, which would enter the eco-cycle harmlessly through biodegradation would be a desirable solution to this problem. However, the "degradable polyethylene" which is presently being promoted as an environmentally friendly alternative to the nondegradable counterpart, does not seem to meet this criterion. This article reviews the state of the art on the aspect of degradability of polyethylene containing pro-oxidants, and more importantly the effect these polymers could have on the environment in the long run. On exposure to heat, light, and oxygen, these polymers disintegrate into small fragments, thereby reducing or increasing the visual presence. However, these fragments can remain in the environment for prolonged time periods. This article also outlines important questions, particularly in terms of time scale of complete degradation, environmental fate of the polymer residues, and possible accumulation of toxins, the answers to which need to be established prior to accepting these polymers as environmentally benign alternatives to their nondegradable equivalents. It appears from the existing literature that our search for biodegradable polyethylene has not yet been realized. PMID:21495645

Roy, Prasun K; Hakkarainen, Minna; Varma, Indra K; Albertsson, Ann-Christine

2011-05-15

76

Photon tunnelling microscopy of polyethylene single crystals  

E-print Network

Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

Srinivasarao, Mohan

77

21 CFR 177.1615 - Polyethylene, fluorinated.  

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

78

21 CFR 177.1615 - Polyethylene, fluorinated.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

79

21 CFR 177.1615 - Polyethylene, fluorinated.  

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

80

21 CFR 177.1615 - Polyethylene, fluorinated.  

Code of Federal Regulations, 2014 CFR

...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...

2014-04-01

81

21 CFR 177.1615 - Polyethylene, fluorinated.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

82

21 CFR 172.260 - Oxidized polyethylene.  

Code of Federal Regulations, 2014 CFR

...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. Oxidized polyethylene may be safely used as a component...

2014-04-01

83

21 CFR 172.260 - Oxidized polyethylene.  

Code of Federal Regulations, 2013 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component...

2013-04-01

84

21 CFR 172.260 - Oxidized polyethylene.  

Code of Federal Regulations, 2011 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component...

2011-04-01

85

21 CFR 172.260 - Oxidized polyethylene.  

Code of Federal Regulations, 2012 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component...

2012-04-01

86

21 CFR 172.260 - Oxidized polyethylene.  

Code of Federal Regulations, 2010 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component...

2010-04-01

87

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

E-print Network

Poly(ethylene oxide sulfide): New Poly(ethylene glycol) Derivatives Degradable in Reductive Received October 1, 2004 Poly(ethylene oxide sulfide) (PEOS), polymers consisting of an internal ethylene. The backbone of these poly(ethylene oxide sulfide) (PEOS) polymers could be degraded into small monomers

Park, Jong-Sang

88

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals  

E-print Network

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 of lamellar single crystals of polyethylene (PE). We obtain thickness, diffraction, and calorimetry data

Allen, Leslie H.

89

Integrin alphaVbeta3 targeted gene delivery using RGD peptidomimetic conjugates with copolymers of PEGylated poly(ethylene imine).  

PubMed

This study describes the synthesis and characterization of five conjugates of poly(ethylene glycol) modified polyethylenimine (PEG-PEIs) coupled in two different synthesis routes to a nonpeptidic pentacyclic RDG-mimetic for integrin receptor-targeted gene delivery. Synthesis of this panel of different conjugates allowed for systematic analysis of structure-activity relationships. Conjugates were therefore characterized regarding molecular composition, DNA condensation, size, and zeta potential of self-assembled polyplexes. In vitro characterization included investigation of blood compatibility, binding affinity to receptor-positive and receptor-negative cells measured by flow cytometry, cellular uptake quantified by scintillation counting, and efficiency and specificity of transfection assayed by reporter gene expression. In a first synthetic approach, low molecular weight PEI (LMW-PEI) was PEGylated using a heterobifunctional PEG linker and coupling of the RGD-mimetic was achieved at the distal end of PEG chains. In a second synthesis route, the RGD-mimetic was directly coupled to AB-block-copolymers of PEI (25 kDa) and PEG (30 kDa). Interactions of RGD-PEG-LMW-PEI conjugates with DNA were strongly impaired, whereas PEG-PEI-RGD conjugates were more promising candidates due to their physicochemical properties and higher receptor specificity. The binding, uptake, and transfection efficiency in receptor-positive cells was strongly increased upon conjugation of the RGD-mimetic to AB-block-copolymers of PEG-PEI and depended on the degree of peptide substitution. The conjugates of PEG-PEI AB-block-copolymers with low ligand density of the RGD-mimetic appear to be promising candidates for in vivo cancer gene therapy. PMID:19476331

Merkel, Olivia M; Germershaus, Oliver; Wada, Carol K; Tarcha, Peter J; Merdan, Thomas; Kissel, Thomas

2009-06-01

90

Hydrogels prepared by electron irradiation of poly(ethylene oxide) in water solution: unexpected dependence of cross-link density and protein diffusion coefficients on initial PEO molecular weight  

Microsoft Academic Search

Under ionizing radiation aqueous solutions of water-soluble polymers become cross-linked and form hydrogels, primarily by radiolysis of water-generating hydroxyl radicals which attack the polymer chains. The chain radicals thus formed create cross-links by coupling. In particular, hydrogels formed from poly(ethylene oxide) are of interest for biomedical applications, including those in which it is necessary to transport large molecules such as

Peter Kofinas; Vassiliki Athanassiou; Edward W. Merrill

1996-01-01

91

Negative Poisson's ratio polyethylene foams  

Microsoft Academic Search

Various polyethylene foams were subjected to thermo-mechanical processing with the aim of transforming them into re-entrant materials exhibiting negative Poisson's ratio. Following transformation, large cell foams (cell sizes of 1 and 2 mm) exhibited re-entrant cell structure and negative Poisson's ratio over a range of processing times and temperatures. Poisson's ratio vs. strain for these foams was similar to prior

B. Brandel; R. S. Lakes

2001-01-01

92

Covalent attachment of lactase to low-density polyethylene films.  

PubMed

Polymer films to which bioactive compounds such as enzymes are covalently attached offer potential for in-package processing of food. Beta-galactosidase (lactase) was covalently attached to surface-functionalized low-density polyethylene films. A two-step wet chemical functionalization introduced 15.7 nmol/cm2 primary amines to the film surface. Contact angle, dye assays, X-ray photoelectron spectroscopy, and appropriate protein assays were used to characterize changes in film surface chemistry after each step in the process of attachment. Glutaraldehyde was used to covalently attach lactase to the surface at a density of 6.0 microg protein per cm2 via reductive amination. The bond between the covalently attached lactase and the functionalized polyethylene withstood heat treatment in the presence of an ionic denaturant with 74% enzyme retention, suggesting that migration of the enzyme into the food product would be unlikely. The resulting polyethylene had an enzyme activity of 0.020 lactase units (LU)/cm2 (approximately 4500 LU/g). These data suggest that enzymes that may have applications in foods can be covalently attached to inert polymer surfaces, retain significant activity, and thus have potential as a nonmigratory active packaging materials. PMID:17995883

Goddard, J M; Talbert, J N; Hotchkiss, J H

2007-01-01

93

Poly(ethylene oxide) functionalization  

DOEpatents

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.

Pratt, Russell Clayton

2014-04-08

94

Light transmission through polyethylene samples  

NASA Astrophysics Data System (ADS)

A spectral calibration Hg(Ar) lamp and a pulsed Nd:YAG laser were employed to study the UV, VIS and IR light transmission through polyethylene samples, as pure and doped with Fe 2O 3 and carbon nanotubes. Optical measurements were performed in the spectral range between 200 nm and 800 nm. Measurements with 0.1% and 1% in weight of filler concentrations were investigated. The polymers' optical absorption coefficients, calculated from the experimental transmitted component, were tabulated at different wavelengths as a function of the analyzed samples. The radiation depth penetration was also evaluated.

Caridi, F.; Torrisi, L.; Visco, A. M.

2012-03-01

95

Single electron states in polyethylene  

SciTech Connect

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.

Wang, Y. [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China) [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); MacKernan, D. [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland)] [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Cubero, D., E-mail: dcubero@us.es, E-mail: n.quirke@imperial.ac.uk [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); Departmento de Física Aplicada I, Universidad de Sevilla, Calle Virgen de Africa 7, 41011 Seville (Spain); Coker, D. F. [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics and Complex Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States); Quirke, N., E-mail: dcubero@us.es, E-mail: n.quirke@imperial.ac.uk [State Key Lab. of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, Shaanxi (China); Department of Chemistry, Imperial College, London SW7 2AY (United Kingdom)

2014-04-21

96

76 FR 54791 - Polyethylene Terephthalate (PET) Film From Korea  

Federal Register 2010, 2011, 2012, 2013, 2014

...Third Review] Polyethylene Terephthalate (PET) Film From Korea Determination On the basis...duty order on polyethylene terephthalate (PET) film from Korea would not be likely to...entitled Polyethylene Terephthalate (PET) Film from Korea: Investigation No....

2011-09-02

97

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 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...

2012-07-01

98

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 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...

2011-07-01

99

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 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...

2013-07-01

100

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 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...

2014-07-01

101

21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Polyethylene glycol (400) monolaurate. 178.3760...Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing...

2014-04-01

102

21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Polyethylene glycol (400) monolaurate. 178.3760...Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing...

2012-04-01

103

Branch content of metallocene polyethylene Ramnath Ramachandran, Gregory Beaucage*  

E-print Network

Branch content of metallocene polyethylene Ramnath Ramachandran, Gregory Beaucage* and Amit catalyzed polyethylene (PE). A novel scaling approach is applied to determine the mole fraction branch solutions of metallocene polyethylene samples, to quantify the LCB content in polymers previously studied

Beaucage, Gregory

104

21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Polyethylene glycol (400) monolaurate. 178.3760...Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing...

2013-04-01

105

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

106

Microvoids in crosslinked polyethylene insulated cables  

Microsoft Academic Search

This paper explains the main. cause of the formation of microvoids (1µm-several 10sµm) in the insulation of crosslinked polyethylene, and the effect of those on the electrial characteristics of cable. Crosslinked polyethylene cable is produced through the process of extruding, moulding, heating, crosslinking and cooling. Steam is usually used as the heating medium. The first cause of the formation of

S. Kageyama; M. Ono; S. Chabata

1975-01-01

107

Suppression of tumor growth in H-ras12V liver cancer mice by delivery of programmed cell death protein 4 using galactosylated poly(ethylene glycol)-chitosan-graft-spermine.  

PubMed

Non-viral gene delivery systems based on polyethyleneimine (PEI) are efficient due to their proton-sponge effect within endosomes, but they have poor physical characteristics such as slow dissociation, cytotoxicity, and non targeted gene delivery. To overcome many of the problems associated with PEI, we synthesized a galactosylated poly(ethylene glycol)-chitosan-graft-spermine (GPCS) copolymer with low cytotoxicity and optimal gene delivery to hepatocytes using an amide bond between galactosylated poly(ethylene glycol) and chitosan-graft-spermine. The GPCS copolymer formed complexes with plasmid DNA, and the GPCS/DNA complexes had well-formed spherical shapes. The GPCS/DNA complexes were nanoscale size with homogenous size distribution and a positive zeta potential by dynamic light scattering (DLS). The GPCS copolymer had lower cytotoxicity than that of PEI 25K in HepG2, HeLa, and A549 cell lines at various concentrations and showed good hepatocyte-targeting ability. Furthermore, GPCS/DNA complexes showed higher levels of GFP expression in the liver in model mice after intravenous injection than naked DNA and metoxy-poly(ethylene glycol)-chitosan-graft-spermine as controls without remarkable fibrosis, inflammation, lipidosis, or necrosis. In a tumor suppression study, an intravenous injection of the GPCS/Pdcd4 complexes significantly suppressed tumor growth, activated apoptosis, and suppressed proliferation and angiogenesis in liver tumor-bearing H-ras12V mice. Our results indicate that the GPCS copolymer has potential as a hepatocyte-targeting gene carrier. PMID:22153867

Kim, Ji-Hye; Minai-Tehrani, Arash; Kim, You-Kyoung; Shin, Ji-Young; Hong, Seong-Ho; Kim, Hye-Joon; Lee, Hee-Do; Chang, Seung-Hee; Yu, Kyeong-Nam; Bang, Yong-Bin; Cho, Chong-Su; Yoon, Tae-Jong; Yu, Dae-Yeul; Jiang, Hu-Lin; Cho, Myung-Haing

2012-02-01

108

Which polyesters can mimic polyethylene?  

PubMed

Self-metathesis of erucic acid by [(PCy(3))(?-C-C(3)H(4)N(2)Mes(2))Cl(2)Ru = CHPh] (Grubbs second- generation catalyst) followed by catalytic hydrogenation and purification via the ester yields 1,26-hexacosanedioate (>99% purity). Polyesterification with 1,26-hexacosanediol, generated from the diester, affords polyester-26,26, which features a T(m) of 114 °C (T(c) = 92 °C, ?H(m) = 160 J g(-1)). Ultralong-chain model polyesters-38,23 (T(m) = 109 °C) and -44,23 (T(m) = 111 °C), generated via multistep procedures including acyclic diene metathesis polymerization, underline that melting points of such aliphatic polyesters do not gradually increase with methylene sequence chain length. Available data suggest that to mimic linear polyethylenes thermal properties, even longer sequences, amounting to at least four times a fatty acid chain, fully incorporated in a linear fashion are required. PMID:23161497

Stempfle, Florian; Ortmann, Patrick; Mecking, Stefan

2013-01-11

109

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a  

E-print Network

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a , Gregory Keywords: Polyethylene Branching Neutron scattering a b s t r a c t Commercial polyethylene is typically and catalyst activity. Further, processing of polyethylene after polymerization may also result in changes

Beaucage, Gregory

110

Protein  

NSDL National Science Digital Library

Protein structure: Primary protein structure is a sequence of amino acids. Secondary protein structure occurs when the amino acids in the sequence are linked by hydrogen bonds. Tertiary protein structure occurs when certain attractions are present between alpha helices and pleated sheets. Quaternary protein structure is a protein consisting of more than one amino acid chain.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-04

111

Surface modification of polymeric biomaterials with poly(ethylene oxide), albumin, and heparin for reduced thrombogenicity  

Microsoft Academic Search

Appropriate surface modification has significantly improved the blood compatibility of polymeric biomaterials. This article reviews methods of surface modification with water-soluble polymers, such as polyethylene oxide (PEO), albumin, and heparin. PEO is a synthetic, neutral, watersoluble polymer, while albumin and heparin are a natural globular protein and an anionic polysaccharide, respectively. When grafted onto the surface, all three macromolecules share

Mansoor Amiji

1993-01-01

112

Friction and wear of hydroxyapatite reinforced high density polyethylene against the stainless steel counterface  

Microsoft Academic Search

Hydroxyapatite (HA) reinforced high density polyethylene (HDPE) was invented as a biomaterial for skeletal applications. In this investigation, tribological properties (e.g. wear rate and coefficient of friction) of unfilled HDPE and HA\\/HDPE composites were evaluated against the duplex stainless steel in dry and lubricated conditions, with distilled water or aqueous solutions of proteins (egg albumen or glucose) being lubricants. Wear

M. Wang; M. Chandrasekaran; W. Bonfield

2002-01-01

113

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

E-print Network

Association of hydrophobically-modified poly(ethylene glycol) with fusogenic liposomes Debra T. Fusogenic liposomes prepared from N-C12-DOPE:DOPC 7:3 (mol:mol) were equilibrated with HMPEGs. Affinity: Fusogenic liposome; Hydrophobically modified PEG; Liposome protection; Complement assay; Comb-graft; Protein

Auguste, Debra T.

114

Controlling Blown Polyethylene Film Optical Properties  

Microsoft Academic Search

The conventional blown process imparts an inherent haze to the product. The percentage of haze varies with certain process variables:1. Surface irregularities caused by melt flow phenomena2. Crystallization behavior3. Melt drawing phenomena in certain types of polyethylene

A. K. Bose

1981-01-01

115

Polyethylene Encasement for Cast-Iron Pipe  

Microsoft Academic Search

External corrosion of buried iron pipe can occur if an area's soil is corrosive. To help protect pipe against electrolytic current, the use of polyethylene encasement is recommended. Standard specifications developed for this product are reviewed in the following.

Walter Amory

1976-01-01

116

Reuse of polyethylene waste in road construction.  

PubMed

The cost of construction of flexible pavements depends on thickness of the pavement layers. The thickness of pavement mainly depends on the strength of the subgrade. By suitable improvement to the strength of the subgrade, considerable saving in the scarce resources and economy can be achieved. Because of their lightweight, easy handling, non-breakable and corrosion free nature, polyethylene have surpassed all other materials in utility. But polyethylene waste has been a matter of concern to environmentalists as it is non-biodegradable. In this investigation, an attempt has been made to study the improvement of California Bearing Ratio (CBR) value of soils stabilized with waste polyethylene bags. This alternative material is mixed in different proportions to the gravel and clay to determine the improvement ofCBR value. Use of the waste polyethylene bags observed to have a significant impact on the strength and economy in pavement construction, when these are available locally in large quantities. PMID:18472564

Raju, S S S V Gopala; Murali, M; Rengaraju, V R

2007-01-01

117

Treeing of Polyethylene at 77K  

Microsoft Academic Search

Ac tree starting voltage of low density polyethylene has been found to be higher at liquid nitrogen temperature (42kV) than that at room temperature (7kV) and it is almost equal to the positive impulse tree starting voltage. This improvement may be due to either the partial-discharge free contact of the interface between the needle electrode and the polyethylene and for

M. Kosaki; N. Shimizu; K. Horii

1977-01-01

118

Radioprotective effect of polyethylene glycol  

SciTech Connect

Polyethylene glycol of molecular weight 400 (PEG-400) had a radioprotective effect of about 20% against lethality when given ip 20 min prior to single or fractionated X-ray doses to the head and neck. Dose modification factors (DMF) based on LD50/15 values ranged from 1.14 to 1.24. A similar DMF of 1.12 based on LD50/30 values was obtained using single doses of whole-body X irradiation. Mice given head and neck irradiation had significantly reduced rectal temperatures (31.3 +/- 3.0/sup 0/C) 9 days post irradiation compared with unirradiated controls (35.4 +/- 0.6/sup 0/C). No such reduction was observed when PEG-400 was given with radiation (36.3 +/- 0.9/sup 0/C). PEG-400 also lessened, but not significantly, the frequency of shivering in irradiated animals. Histopathologic examination of the oral structures demonstrated only marginal protection by PEG-400. Estimation of the alpha/beta ratio from LD50 data on head and neck-irradiated mice yielded values of 4.4 +/- 1.9 (95% confidence limits) Gy without PEG-400 and 7.9 +/- 1.4 Gy with PEG-400. Since it is a non-thiol radioprotector, PEG-400 may be more useful when combined with more conventional thiol-containing radioprotectors.

Shaeffer, J.; Schellenberg, K.A.; Seymore, C.H.; Schultheiss, T.E.; el-Mahdi, A.M.

1986-07-01

119

Osmotic effects of polyethylene glycol.  

PubMed

Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution. PMID:3345895

Schiller, L R; Emmett, M; Santa Ana, C A; Fordtran, J S

1988-04-01

120

Charge packets modeling in polyethylene  

NASA Astrophysics Data System (ADS)

Charge packets in insulating polymers have been reported by many groups within the last two decades, especially in polyethylene-based materials. They consist in a pulse of net charge that remains in the form of a pulse as it crosses the insulation. In spite of a variety of characteristics depending on material properties and experimental conditions, one of the puzzling aspects of the packets is their repetitive character until they eventually die away. Several theories have been proposed to explain their formation and propagation. Two of them have the advantage of simplicity and of being physically based, being the existence of an hysteresis loop in the injection mechanism or a negative differential mobility of carriers with the electric field. Based on these descriptions, some progress has been done recently by discussing the shape of the packets during their propagation but none of the concepts has been incorporated into a transport model to describe the full evolution from the packet generation to their vanishing. Here, we used a simplified transport model featuring bipolar charge injection and transport coupled to specific conditions in charge injection or carrier mobility to reproduce experimental results. One of the salient features of the results is that both models are able to reproduce the repetitive character and the dying away of the packets that appear to be linked with the internal field distribution modulated by a bipolar space charge.

Baudoin, F.; Laurent, C.; Teyssedre, G.; Le Roy, S.

2014-04-01

121

Protein  

MedlinePLUS

... sources, such as fruits, vegetables, grains, nuts and seeds, lack one or more essential amino acids. Vegetarians ... protein came from animal sources. Diabetes Again, protein quality matters more than protein quantity when it comes ...

122

Space Charge Distribution and Crystalline Structure in Low-Density Polyethylene modified by Metallocene Catalyzed Polyethylene  

Microsoft Academic Search

A small amount of metallocene catalyzed polyethylene (MPE) was blended into low-density polyethylene (LDPE) in this paper. Then the space charge profile in the blends was measured by pulsed electro-acoustic (PEA) method, which showed that the space charges were greatly decreased and field distributions tended to be uniform in LDPE blended with 1 wt% MPE. At the same time the

Wang Xia; Wu Chaoyi; Tu Demin; Lei Chao; Du Qiangguo

2006-01-01

123

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

124

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

125

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

126

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

127

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

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

128

Polymeric compositions incorporating polyethylene glycol as a phase change material  

DOEpatents

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.

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

1989-01-01

129

ABA-triblock copolymers from biodegradable polyester A-blocks and hydrophilic poly(ethylene oxide) B-blocks as a candidate for in situ forming hydrogel delivery systems for proteins  

Microsoft Academic Search

Hydrogels are very attractive delivery systems for hydrophilic macromolecules such as proteins and DNA because they provide a protective environment and allow control of diffusion by adjusting cross-link densities. Physically cross-linked hydrogels generated by rapid swelling upon exposure to an aqueous environment can be obtained from ABA triblock copolymers containing hydrophobic polyester A-blocks and hydrophilic polyether B-blocks. They provide an

Thomas Kissel; Youxin Li; Florian Unger

2002-01-01

130

Exact Topological Twistons in Crystalline Polyethylene  

E-print Network

We investigate the presence of topological twistons in crystalline polyethylene. We describe crystalline polyethylene with a model that couples the torsional and longitudinal degrees of freedom of the polymeric chain by means of a system of two real scalar fields. This model supports topological twistons, which are described by exact and stable topological solutions that appear when the interaction between torsional and longitudinal fields is polynomial, containing up to the sixth power in the fields. We calculate the energy of the topological twiston, and the result is in very good agreement with the value obtained via molecular simulation.

E. Ventura; A. M. Simas; D. Bazeia

2000-04-04

131

Alumina-on-Polyethylene Bearing Surfaces in Total Hip Arthroplasty  

PubMed Central

The long-term durability of polyethylene lining total hip arthroplasty (THA) mainly depends on periprosthetic osteolysis due to wear particles, especially in young active patients. In hip simulator study, reports revealed significant wear reduction of the alumina ceramic-on-polyethylene articulation of THA compared with metal-on-polyethylene bearing surfaces. However, medium to long-term clinical studies of THA using the alumina ceramic-on-polyethylene are few and the reported wear rate of this articulation is variable. We reviewed the advantages and disadvantages of ceramicon- polyethylene articulation in THA, hip simulator study and retrieval study for polyethylene wear, in vivo clinical results of THA using alumina ceramic-on-polyethylene bearing surfaces in the literature, and new trial alumina ceramic-onhighly cross linked polyethylene bearing surfaces. PMID:20224739

Jung, Yup Lee; Kim, Shin-Yoon

2010-01-01

132

21 CFR 177.1630 - Polyethylene phthalate polymers.  

Code of Federal Regulations, 2011 CFR

...safely used as, or components of plastics (films, articles, or fabric) intended for...conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene...in coatings for polyethylene phthalate films complying with paragraph (a) of this...

2011-04-01

133

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Polyethylene Terephthalate (Pet) Film From Korea AGENCY: United States International...order on polyethylene terephthalate (PET) film from Korea...revocation of the antidumping order on PET film from Korea would be likely to lead to...

2011-02-15

134

21 CFR 177.1630 - Polyethylene phthalate polymers.  

Code of Federal Regulations, 2012 CFR

...safely used as, or components of plastics (films, articles, or fabric) intended for...conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene...in coatings for polyethylene phthalate films complying with paragraph (a) of this...

2012-04-01

135

21 CFR 177.1630 - Polyethylene phthalate polymers.  

Code of Federal Regulations, 2010 CFR

...safely used as, or components of plastics (films, articles, or fabric) intended for...conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene...in coatings for polyethylene phthalate films complying with paragraph (a) of...

2010-04-01

136

21 CFR 177.1630 - Polyethylene phthalate polymers.  

Code of Federal Regulations, 2014 CFR

...safely used as, or components of plastics (films, articles, or fabric) intended for...conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene...in coatings for polyethylene phthalate films complying with paragraph (a) of this...

2014-04-01

137

21 CFR 177.1630 - Polyethylene phthalate polymers.  

Code of Federal Regulations, 2013 CFR

...safely used as, or components of plastics (films, articles, or fabric) intended for...conditions: (a) Polyethylene phthalate films consist of a base sheet of ethylene...in coatings for polyethylene phthalate films complying with paragraph (a) of this...

2013-04-01

138

Protein  

MedlinePLUS

... meet their protein needs. With some planning, a vegetarian diet can easily meet the recommended protein needs of ... the American Dietetic Association and Dietitians of Canada: Vegetarian diets. JADA , 2003; 103(6) 748 – 765. 2 Source ...

139

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 Abstract The statistics of polyethylene chains in the amorphous region between two crystallites have been as models of the chain molecules in the amorphous region of semicrystalline polyethylene, both

Aluffi, Paolo

140

Irradiation effects in high-density polyethylene Jussi Polvia  

E-print Network

Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold energy for creating defects in the polyethylene lattice as a function of the incident angle. We found

Nordlund, Kai

141

Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles  

E-print Network

Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles W. Brullot a in revised form 20 December 2011 Available online 3 February 2012 Keywords: Ferrofluid Polyethylene glycol Magneto-optics Magnetite Rheology a b s t r a c t Versatile ferrofluids based on polyethylene glycol

142

Automated Assessment of Polyethylene Wear in Cemented Acetabular Components using  

E-print Network

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 to the polyethylene acetabular component of a prosthesis so that both it and the metal femoral head component can

St Andrews, University of

143

An Instability Leading to Failure of Polyethylene in Uniaxial Creep  

E-print Network

An Instability Leading to Failure of Polyethylene in Uniaxial Creep L. J. ZAPAS and J. M. CRISSMAN model, a point of instability is pre- dicted for the uniaxial creep of high density polyethylene. From dead load experiments it has been found that the instabil- ity occurs for linear -polyethylene

144

NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS  

E-print Network

#12;NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS BY ALEX TAN KWAN B.S., Stanford) device, the nanocalorimeter, it was possible to investigate the melting of isolated polyethylene (PE, a simple Ni-foil calorimeter, to measure the heat capacity of a thin polyethylene film to verify

Allen, Leslie H.

145

Adsorption of Polypropylene and Polyethylene on Liquid Chromatographic  

E-print Network

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 solutions. It was found that polyethylene is fully or partially retained from thermodynamically good sol

Li, Jing

146

Test method Evaluating the influence of contacting fluids on polyethylene  

E-print Network

Test method Evaluating the influence of contacting fluids on polyethylene using acoustic emissions emissions Polyethylene Penetrant Toluene Aqueous detergent a b s t r a c t Identifying microstructural) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure

Thompson, Michael

147

Optical Properties and Orientation in Polyethylene Blown Films  

E-print Network

Optical Properties and Orientation in Polyethylene Blown Films AYUSH BAFNA,1 GREGORY BEAUCAGE,1 properties of blown poly- ethylene films. Two types of blown polyethylene films of similar degrees of crystallinity were made from (1) single-site-catalyst high-density polyethylene (HDPE; STAR ) and (2) Ziegler

Beaucage, Gregory

148

Synthesis and characterization of maleated polyethylene\\/clay nanocomposites  

Microsoft Academic Search

Maleic anhydride grafted polyethylene (maleated polyethylene)\\/clay nanocomposites were prepared by simple melt compounding. The exfoliation and intercalation behaviors depended on the hydrophilicity of polyethylene grafted with maleic anhydride and the chain length of organic modifier in the clay. When the number of methylene groups in alkylamine (organic modifier) was larger than 16, the exfoliated nanocomposite was obtained, and the maleic

Ki Hyun Wang; Min Ho Choi; Chong Min Koo; Yeong Suk Choi; In Jae Chung

2001-01-01

149

RESEARCH ARTICLE Biodegradable mulch instead of polyethylene for weed  

E-print Network

RESEARCH ARTICLE Biodegradable mulch instead of polyethylene for weed control of processing tomato Abstract Black polyethylene (PE) film is used for mulch- ing in processing tomato (Lycopersicon esculentum be an alternative. Keywords Polyethylene . Biodegradable mulch . Paper. Barley straw 1 Introduction Weeds

Paris-Sud XI, Université de

150

Development of polymeric foams from recycled polyethylene and recycled gypsum  

Microsoft Academic Search

The extrusion foaming of recycled polyethylene through different foaming agents has been studied. Cellular structures were obtained in a single screw extruder with different grades of polyethylene (low and high density), using recycled gypsum and a commercial foaming agent (azodicarbonamide). Differential scanning calorimetry and thermogravimetric analysis were used to characterize the transition temperatures of the polyethylenes used, and the dissociation

A. Greco; A. Maffezzoli; O. Manni

2005-01-01

151

High-pressure vibrational properties of polyethylene  

NASA Astrophysics Data System (ADS)

The pressure evolution of the vibrational spectrum of polyethylene was investigated up to 50 GPa along different isotherms by Fourier-transform infrared and Raman spectroscopy and at 0 K by density-functional theory calculations. The infrared data allow for the detection of the orthorhombic Pnam to monoclinic P21/m phase transition which is characterized by a strong hysteresis both on compression and decompression experiments. However, an upper and lower boundary for the transition pressure are identified. An even more pronounced hysteresis is observed for the higher-pressure transition to the monoclinic A2/m phase. The hysteresis does not allow in this case the determination of a well defined P-T transition line. The ambient structural properties of polyethylene are fully recovered after compression/decompression cycles indicating that the polymer is structurally and chemically stable up to 50 GPa. A phase diagram of polyethylene up to 50 GPa and 650 K is proposed. Analysis of the pressure evolution of the Davydov splittings and of the anomalous intensification with pressure of the IR active wagging mode provides insight about the nature of the intermolecular interactions in crystalline polyethylene.

Fontana, Luca; Santoro, Mario; Bini, Roberto; Vinh, Diep Q.; Scandolo, Sandro

2010-11-01

152

Ultrasonically enhanced persulfate oxidation of polyethylene surfaces  

Microsoft Academic Search

The ultrasonically enhanced oxidation of polyethylene surfaces by potassium and ammonium persulfates is described. The use of ultrasound allows significant levels of surface modification to be achieved using these oxidizing agents under mild conditions. Changes in the water contact angle and attenuated total reflection infra-red spectra were used to follow the changes in surface chemistry. Variation of conditions such as

Fiona Keen

1996-01-01

153

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...

154

21 CFR 177.1610 - Polyethylene, chlorinated.  

Code of Federal Regulations, 2010 CFR

...and Repeated Use Food Contact Surfaces § 177.1610...components of articles that contact food, except for articles...Materials, 100 Barr Harbor Dr., West Conshohocken...Administration (NARA). For information on the availability...polyethylene may be used in contact with all types of...

2010-04-01

155

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...

156

Crosslinked polyethylene foams, via EB radiation  

Microsoft Academic Search

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

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

1998-01-01

157

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 ...

158

Preservation of Mercury in Polyethylene Containers.  

ERIC Educational Resources Information Center

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)

Piccolino, Samuel Paul

1983-01-01

159

Clinical Performance of Contemporary Tibial Polyethylene Components  

Microsoft Academic Search

A postclinical retrieval analysis was performed on 43 polyethylene tibial components of a contemporary total knee arthroplasty system with implantation duration between 12 and 80 months. Components were scored for 8 potential modes of surface wear or damage on the top and back surfaces. Moderate backside wear of 4.1 ?m\\/y was documented by measuring the extent of manufacturer's engraved lettering

Roy D. Crowninshield; Markus A. Wimmer; Joshua J. Jacobs; Aaron G. Rosenberg

2006-01-01

160

Poly(ethylene terephthalate)\\/polyethylene composite based on in-situ microfiber formation  

Microsoft Academic Search

Poly(ethylene terephthalate) (PET) microfiber was in-situ formed by compounding PET with polyethylene (PE) through a single screw extruder of a Haake rheometer system, where a rod die with comparatively smaller diameter (2.1 mm) was used, and the extrudate was drawn in a certain drawing ratio (3.1:1) and quickly cooled in cold water. Subsequently, the in-situ PET\\/PE composite was injection molded into

Z. M. Li; M. B. Yang; R. Huang; W. Yang; J. M. Feng

2002-01-01

161

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

E-print Network

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...

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

2011-01-01

162

Compatibilization of polyethylene\\/aluminum hydroxide (PE\\/ATH) and polyethylene\\/magnesium hydroxide (PE\\/MH) composites with functionalized polyethylenes  

Microsoft Academic Search

Study was made of the compatibilization of polyethylene\\/aluminum hydroxide (PE\\/ATH) and polyethylene\\/magnesium hydroxide (PE\\/MH) composites with composition 60\\/40wt%. Compatibilizers were hydroxyl or carboxylic acid functionalized copolymers prepared in our laboratory with metallocene catalysts and commercial butyl acrylate, maleic anhydride, epoxy, and acrylic acid functionalized polyethylenes. Comparison was made with stearic acid treatment of the composites. The effect of polymeric compatibilizers

U Hippi; J Mattila; M Korhonen; J Seppälä

2003-01-01

163

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

PubMed Central

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

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

2008-01-01

164

Proteins  

NSDL National Science Digital Library

Paul Anderson explains the structure and importance of proteins. He describes how proteins are created from amino acids connected by dehydration synthesis. He shows the importance of chemical properties in the R-groups of individual amino acids in the polypeptide.

Paul Anderson

2013-03-12

165

Proteins  

NSDL National Science Digital Library

Laboratory manual and supplemental resources that were developed for a college laboratory course in protein purification. The enzyme, Beta-galactosidase, is purified in two steps, with analysis and verification of results. Course materials are divided into four units: Why Proteins, Assays, The Purification Process, and Analysis and Verification. Powerpoint lectures and study guides are provided.

Mowery, Jeanette

166

Proteins.  

ERIC Educational Resources Information Center

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)

Doolittle, Russell F.

1985-01-01

167

Method for determination of polyethylene glycol molecular weight.  

PubMed

A method utilizing competitive adsorption between polyethylene glycols (PEGs) and labeled protein to nanoparticles was developed for the determination of PEG molecular weight (MW) in a microtiter plate format. Two mix-and-measure systems, time-resolved luminescence resonance energy transfer (TR-LRET) with donor europium(III) polystyrene nanoparticles and acceptor-labeled protein and quenching with quencher gold nanoparticles and fluorescently labeled protein were compared for their performance. MW is estimated from the PEG MW dependent changes in the competitive adsorption properties, which are presented as the luminescence signal vs PEG mass concentration. The curves obtained with the TR-LRET system overlapped for PEGs larger than 400 g/mol providing no information on MW. Distinctly different curves were obtained with the quenching system enabling the assessment of PEG MW within a broad dynamic range. The data was processed with and without prior knowledge of the PEG concentration to measure PEGs over a MW range from 62 to 35?000 g/mol. The demonstration of the measurement independent of the PEG concentration suggests that the estimation of MW is possible with quenching nanoparticle system for neutrally charged and relatively hydrophilic polymeric molecules widening the applicability of the simple and cost-effective nanoparticle-based methods. PMID:25783500

Pihlasalo, Sari; Hänninen, Pekka; Härmä, Harri

2015-04-01

168

Speciation of antimony in polyethylene terephthalate bottles  

SciTech Connect

Antimony contamination has been reported in drinking water from polyethylene terephthalate (PET) bottles. Micro-X-ray fluorescence (XRF) analysis has been used to identify the distribution and chemical form of residual antimony used as a catalyst in the manufacture of PET bottles. The results are consistent with clusters of Sb(III) having dimensions of the order of tens of micrometers, clearly showing the ability of synchrotron radiation analyses to both map elemental distribution and determine oxidation state.

Martin, R.R.; Ablett, J.; Shotyk, W.S.; Naftel, S.; Northrup, P.

2009-12-18

169

Structure and plastic deformation of polyethylene  

Microsoft Academic Search

A review is given of the structure of semi-crystalline polymers and the mechanisms of plastic deformation in them. High-density polyethylene (HDPE) is taken as the specific example because of the large number of detailed studies performed on this material. The early findings are also compared and contrasted with very recent detailed large-strain deformation studies and computer simulations of deformation-induced texture

L. Lin; A. S. Argon

1994-01-01

170

Thermophilic microbial degradation of polyethylene succinate  

Microsoft Academic Search

This paper examined the biodegradability of a new aliphatic polyester, polyethylene succinate (PES), at a high incubation temperature of 50°C. The distribution and population of total colonies and of PES degrading micro organisms on polymer-emulsified agar plates were determined using the plate count and clear zone methods. The PES-decomposers were present in six of 10 soil samples and the total

M. L. Tansengco; Y. Tokiwa

1998-01-01

171

Injectable cartilage using polyethylene oxide polymer substrates.  

PubMed

This study demonstrates that polyethylene oxide gels, which are biocompatible and biodegradable synthetic polymers, can be utilized for the encapsulation of isolated chondrocytes and maintenance of three-dimensional spatial support for new tissue development. Chondrocytes isolated from the glenohumeral and humeroradioulnar joints of a calf were added to a 20% polyethylene oxide solution in Ham's F-12 medium to generate a final cellular density of 10 x 10(6)/mL. The polymer-chondrocyte constructs were injected through a 22-gauge needle in 500-microliters aliquots subcutaneously in 12 nude mice and incubated for 6 and 12 weeks in vivo. Histologic and biochemical analyses including deoxyribonucleic acid and glycosaminoglycan quantitative analyses confirmed the presence of actively proliferating chondrocytes with production of a well-formed cartilaginous matrix in the transplanted samples. Control specimens from eight implantation sites consisting of chondrocytes alone or polyethylene oxide substrates did not demonstrate any gross or histologic evidence of neocartilage formation. These findings demonstrate the potential use of an injectable and moldable polymer substrate that can support cell proliferation and matrix synthesis after subcutaneous transplantation for neocartilage generation. The use of functional biologic tissue substitutes may serve as an alternative solution to current methods of augmentation or reconstruction of structural craniofacial contour deformities. PMID:8823024

Sims, C D; Butler, P E; Casanova, R; Lee, B T; Randolph, M A; Lee, W P; Vacanti, C A; Yaremchuk, M J

1996-10-01

172

Polyethylene solidification of low-level wastes  

SciTech Connect

This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs.

Kalb, P.D.; Colombo, P.

1985-02-01

173

Preparation of extruded polyethylene/chitosan blends compatibilized with polyethylene-graft-maleic anhydride.  

PubMed

Novel films of polyethylene and chitosan were obtained using extrusion. These polymers have interesting properties, and processing them with methods that are of high use in the industry, such as the extrusion method, can have a significant effect on the potential applications of these materials. The individual materials were thermally characterized; after this, extruded films of low density polyethylene and chitosan mixtures were prepared with the addition of polyethylene-graft-maleic anhydride as a compatibilizer for the blends, and glycerol, as a plasticizer for chitosan. The use of compatibilizer and plasticizer agents improved the processability and compatibility of the mixtures, as well as their mechanical properties, as revealed by mechanical property measurements and scanning electron microscopy. It was possible to prepare blends with a maximum chitosan content of 20 wt%. The material stiffness increased with the increase of chitosan in the sample. FTIR studies revealed the existence of an interaction between the compatibilizer and chitosan. PMID:24299879

Quiroz-Castillo, J M; Rodríguez-Félix, D E; Grijalva-Monteverde, H; Del Castillo-Castro, T; Plascencia-Jatomea, M; Rodríguez-Félix, F; Herrera-Franco, P J

2014-01-30

174

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

PubMed Central

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

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

2012-01-01

175

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-print Network

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.

Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

2015-02-07

176

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-print Network

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.

Razeghizadeh, Alireza; Lavafpour, Farhad

2015-01-01

177

Development of Macroporous Poly(ethylene glycol) Hydrogel Arrays Within Microfluidic Channels  

PubMed Central

The mass transport of solutes through hydrogels is an important design consideration in materials used for tissue engineering, drug delivery, and protein arrays used to quantify protein concentration and activity. We investigated the use of poly(ethylene glycol) (PEG) as a porogen to enhance diffusion of macromolecules into the interior of polyacrylamide and PEG hydrogel posts photopatterned within microfluidic channels. The diffusion of GST–GFP and dextran–FITC into hydrogels was monitored and effective diffusion coefficients were determined by fitting to the Fickian diffusion equations. PEG-diacrylate (Mr 700) with porogen formed a macroporous structure and permitted significant penetration of 250 kDa dextran. Proteins copolymerized in these macroporous hydrogels retained activity and were more accessible to antibody binding than proteins copolymerized in nonporous gels. These results suggest that hydrogel macroporosity can be tuned to regulate macromolecular transport in applications such as tissue engineering and protein arrays. PMID:21028794

Lee, Andrew G.; Arena, Christopher P.; Beebe, David J.; Palecek, Sean P.

2010-01-01

178

Patterned functional carbon fibers from polyethylene  

SciTech Connect

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.

Hunt, Marcus A [ORNL; Saito, Tomonori [ORNL; Brown, Rebecca H [ORNL; Kumbhar, Amar S [University of North Carolina, Chapel Hill; Naskar, Amit K [ORNL

2012-01-01

179

Soluble hyperbranched grafts on polyethylene surfaces  

E-print Network

of deprotonated hyperbranched poly [(acrylic acid)-co-(N, N-dimethylacrylamide)]: (a) Spectra of 27. 5 I ratio of acid:amide shows larger carboxylate peak (1550 cm ') than amide peak (1650 cm '); (b) Spectra of I:I ratio of acid:amide shows no acid present; (c...) Spectra of 6. 25 I ratio of acid:amide shows approximately equal amounts of carboxylate and amide peaks 61 3-11 XPS analyses of hyperbranched copolymer gratis on polyethylene surfaces; ( ~ ) represents the percentage of carbon present in sample; (V...

Britton, Danielle M

2002-01-01

180

Polyethylene terephthalate thin films; a luminescence study  

NASA Astrophysics Data System (ADS)

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.

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

2015-04-01

181

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

182

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

183

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Alkyl polyethylene glycol phosphate, potassium salt...Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt...substance identified generically as alkyl polyethylene glycol phosphate, potassium...

2011-07-01

184

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

Code of Federal Regulations, 2014 CFR

...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

2014-07-01

185

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

Code of Federal Regulations, 2013 CFR

...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked...polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

2013-07-01

186

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

Code of Federal Regulations, 2013 CFR

...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or...

2013-04-01

187

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-549-821] Polyethylene Retail Carrier Bags From Thailand...review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from...subject to the antidumping duty order is polyethylene retail carrier bags, which are...

2013-05-14

188

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Polyethylene glycol (400) mono- and dioleate...Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and...

2013-04-01

189

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-01-02

190

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Alkyl polyethylene glycol phosphate, potassium salt...Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt...substance identified generically as alkyl polyethylene glycol phosphate, potassium...

2012-07-01

191

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Polyethylene glycol (400) mono- and dioleate...Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and...

2011-04-01

192

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

Code of Federal Regulations, 2012 CFR

...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or...

2012-04-01

193

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

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Polyethylene glycol (400) mono- and dioleate...Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and...

2014-04-01

194

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Alkyl polyethylene glycol phosphate, potassium salt...Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt...substance identified generically as alkyl polyethylene glycol phosphate, potassium...

2014-07-01

195

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9...and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this...

2011-04-01

196

Polyethylene glycol, unique among laxatives, suppresses aberrant crypt foci, by elimination of cells  

E-print Network

Polyethylene glycol, unique among laxatives, suppresses aberrant crypt foci, by elimination Corpet Abstract Background Polyethylene glycol (PEG), an osmotic laxative, is a very ; Polyethylene Glycols ; pharmacology ; therapeutic use ; Precancerous Conditions ; chemically induced

Paris-Sud XI, Université de

197

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Pentenylated polyethylene glycol sulfate salt (generic...Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt (generic...identified generically as pentenylated polyethylene glycol sulfate salt (PMN...

2013-07-01

198

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Polyethylene glycol (400) mono- and dioleate...Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and...

2012-04-01

199

Accepted Manuscript Kinetic modelling of high density polyethylene pyrolysis: Part 2. Reduction of existing  

E-print Network

Accepted Manuscript Kinetic modelling of high density polyethylene pyrolysis: Part 2. Reduction density polyethylene pyrolysis: Part 2. Reduction of existing detailed mechanism, Polymer Degradation Modelling of High Density PolyEthylene Pyrolysis: Part 2. Reduction of existing detailed mechanism. N

Paris-Sud XI, Université de

200

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9...and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this...

2010-04-01

201

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-10-04

202

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Polyethylene glycol (mean molecular weight 200-9...and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this...

2012-04-01

203

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

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Polyethylene glycol (mean molecular weight 200-9...and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this...

2014-04-01

204

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-12-17

205

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2011-12-05

206

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

Code of Federal Regulations, 2014 CFR

...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...patch or pledget made of polypropylene, polyethylene terephthalate, or...

2014-04-01

207

Sodalite ion exchange in polyethylene oxide oligomer solvents Gina M. Canfield,a  

E-print Network

Sodalite ion exchange in polyethylene oxide oligomer solvents Gina M. Canfield,a Michael Bizimisb and rare earth ions. Ethylene oxide-based oligomers (polyethylene glycol, polyethylene glycol methyl ether

Latturner, Susan

208

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Polyethylene glycol (mean molecular weight 200-9...and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this...

2013-04-01

209

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

210

77 FR 14501 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension...AD) order on polyethylene terephthalate film, sheet and strip from India covering the...2011. See Polyethylene Terephthalate Film, Sheet and Strip From India:...

2012-03-12

211

75 FR 65450 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension...duty order on polyethylene terephthalate film, sheet and strip from India for the period...2009. See Polyethylene Terephthalate Film, Sheet and Strip from India:...

2010-10-25

212

75 FR 79336 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension...duty order on polyethylene terephthalate film, sheet and strip from India for the period...2009. See Polyethylene Terephthalate Film, Sheet and Strip from India:...

2010-12-20

213

75 FR 69400 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension...duty order on polyethylene terephthalate film, sheet and strip from India for the period...2009. See Polyethylene Terephthalate Film, Sheet and Strip from India:...

2010-11-12

214

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

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Extension...duty order on polyethylene terephthalate film, sheet and strip from India for the period...2009. See Polyethylene Terephthalate Film, Sheet and Strip from India:...

2010-12-22

215

76 FR 9745 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping...antidumping duty order on polyethylene terephthalate film (PET Film) from Taiwan. See Polyethylene Terephthalate...

2011-02-22

216

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-12-27

217

Self-Healing of Polyethylene Oxide  

NASA Astrophysics Data System (ADS)

Autonomic self-healing is expected to enhance the lifetime of polymeric materials, resins, and composites subjected to long term mechanical stresses. The self-healing process is initiated by the rupture of some polyurea-formaldehyde microcapsules filled with monomer. The self-healing polymer is actually a compound containing microcapsules filled with monomer and catalyst particles. The monomer released from these broken microcapsules is diffusing within the polymer, reacting with the catalyst and starting a polymerization reaction. This new polymer, growing within the propagating crack, stops the mechanical failure. While the process is pretty slow (timescale of the order of 10 to 100 s), there are many important technological applications that would benefit from the availability of self-healing polymers. We report about the addition of self-healing capabilities to polyethylene oxide by using polyurea formaldehyde microcapsules filled with dicyclopentadiene and first generation Grubbs catalysts. Details regarding the physical and chemical steps used to add self-healing capabilities to polyethylene oxide will be presented. Self-healing efficiency was assessed by fatigues tests.

Magdalena Chipara, Dorina; Flores, Maritza; Puente, Nancy; Lozano, Karen

2011-03-01

218

Recycling of irradiated high-density polyethylene  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

219

Poly(ethylene glycol) Self-Assembled Monolayer Island Growth  

E-print Network

Hopkins School of Medicine. (1) PEG is also referred to as poly(ethylene oxide) (POE) or polyPoly(ethylene glycol) Self-Assembled Monolayer Island Growth Jonas Rundqvist, Jan H. Hoh, and David. This height change can be associated with a molecular conformational transition. Introduction Poly(ethylene

Haviland, David

220

Polyethylene encapsulation full-scale technology demonstration. Final report  

Microsoft Academic Search

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

P. D. Kalb; P. R. Lageraaen

1994-01-01

221

Space charge measurement techniques and space charge in polyethylene  

Microsoft Academic Search

Recently, several new techniques such as LIPP, PIPS, PEA and TP methods have been developed to measure directly the space charge distributions in insulating polymers. Many papers have been published on space charge in insulating materials. In this paper, the space charge measurement techniques and space charge in polyethylene are reviewed. The space charge distributions in polyethylene depend strongly upon

T. Mizutani

1994-01-01

222

Optimal grade transitions in a gas phase polyethylene reactor  

Microsoft Academic Search

This paper reports that using gas-phase technology many grades of polyethylene can be produced in a single reactor. For a series of three polyethylene products, model-based dynamic optimization is used to determine optimal grade changeover policies. Optimal manipulated variable profiles are determined for hydrogen and butene feed rates, reactor temperature setpoint, gas bleed flow, catalyst feed rate, and bed level

K. B. McAuley; J. F. MacGregor

1992-01-01

223

Fracture mechanics analysis of slow crack growth in polyethylene  

E-print Network

Slow crack growth in polyethylene is often the limiting factor in long-term service of plastic pipe or other structural applications. A new test method and analysis method was developed to study slow crack growth in polyethylene. Two high density...

Self, Robert Alan

1997-01-01

224

Modification of textile acetate yarn with polyethylene oxide  

Microsoft Academic Search

Small proportions of polyethylene oxides are known to exert a modifying effect on acetate fibre when added to the common solvent. In the case of textile yarn the effect is optimum (improved fatigue strength) when the polymer solution contains I 2% polyethylene oxide (PEO) of a molecular weight of 4000 - 5000 \\/I\\/. Several batches of modified textile acetate yarn

M. Sh. Tairov; M. V. Polovnikova; D. I. Kalandarov; P. I. Baboshkin; Z. Z. Gulombaev; A. A. Saidov

1975-01-01

225

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...

226

Extensional rheology of shear-thickening fumed silica nanoparticles dispersed in an aqueous polyethylene  

E-print Network

polyethylene oxide solution Sunilkumar Khandavalli and Jonathan P. Rothsteina) Mechanical and Industrial rheology of fumed silica nanoparticles dispersed in an aqueous polyethylene oxide (PEO) solution

Rothstein, Jonathan

227

Selected Physical Characteristics of Polystyrene/High Density Polyethylene Composites Prepared from Virgin  

E-print Network

Selected Physical Characteristics of Polystyrene/High Density Polyethylene Composites Prepared from: Mixtures of polystyrene and high density polyethylene were injection molded from recycled and virgin

228

Polyethylene glycol-induced mammalian cell hybridization: Effect of polyethylene glycol molecular weight and concentration  

Microsoft Academic Search

The effects of polyethylene glycol (PEG) molecular weight and concentration on mammalian cell hybridization were studied. The peak hybridization-inducing activity with all grades of PEG from 400–6000 was found to occur in the concentration range of 50–55%. However, changes in concentration were seen to have different quantitative effects with different grades of PEG. For monolayer fusions, PEG 1000 at 50%

Richard L. Davidson; Kathleen A. O'Malley; Thomas B. Wheeler

1976-01-01

229

Polyethylene glycolated PAMAM dendrimers-Efavirenz conjugates  

PubMed Central

Aim: The preparation of novel PEGylated PAMAM (poly-amidoamine) dendrimers for delivery of anti-HIV drug Efavirenz is reported. Method and Materials: About 5.0 G PAMAM dendrimers are prepared by ethylene diamine core via Michael addition by divergent method. PEGylation is done by polyethylene glycol 600 using epichlorhydrin as linker. PEGylated 5.0 G PAMAM dendrimers loaded with Efavirenz (EFV) are evaluated for FTIR, DSC, SEM, drug release, and stability studies. Results and Conclusion: From the results it is proved that this method is less time consuming, inexpensive, and reproducible. Drug-release studies indicate, PEGylated 5.0 G PAMAM-EFV dendrimers have shown prolonged drug-release property. PMID:24678457

Pyreddy, Suneela; Kumar, Pandurangan Dinesh; Kumar, Palanirajan Vijayaraj

2014-01-01

230

Crosslinked polyethylene foams, via EB radiation  

NASA Astrophysics Data System (ADS)

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.

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

1998-06-01

231

Annealing of single lamella nanoparticles of polyethylene  

E-print Network

We study the change of the size and structure of freely suspended single lamella nanoparticles of polyethylene during thermal annealing in aqueous solutions. Using small-angle x-ray scattering and cryogenic transmission electron microscopy, it is shown that a doubling of the crystalline lamella sandwiched between two amorphous polymer layers is obtained by annealing the nanoparticles at 125 C. This thickening of the crystalline lamella can be understood in terms of an unlooping of polymer chains within a single nanoparticle. In addition a variation of the annealing temperature from 90 C to 115 C demonstrates that the inverse of the crystalline lamellar thickness increases linearly with the annealing temperatures leading to a recrystallization line in a Gibbs-Thomson graph. Since the nanoparticles consist of about only eight polymer chains, they can be considered as a ideal candidates for the experimental realization of equilibrium polymer crystals.

Christophe N. Rochette; Sabine Rosenfeldt; Katja Henzler; Frank Polzer; Matthias Ballauff; Qiong Tong; Stefan Mecking; Markus Drechsler; Theyencheri Narayanan; Ludger Harnau

2011-07-05

232

Single chain elasticity and thermoelasticity of polyethylene  

E-print Network

Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated.

John T. Titantah; Carlo Pierleoni; Jean-Paul Ryckaert

2002-09-05

233

Vacuum Outgassing of High Density Polyethylene  

SciTech Connect

A combination of thermogravimetric analysis (TGA) and temperature programmed decomposition (TPD) was employed to identify the outgassing species, the total amount of outgassing, and the outgassing kinetics of high density polyethylene (HDPE) in a vacuum environment. The isoconversional kinetic analysis was then used to analyze the outgassing kinetics and to predict the long-term outgassing of HDPE in vacuum applications at ambient temperature. H{sub 2}O and C{sub n}H{sub x} with n as high as 9 and x centering around 2n are the major outgassing species from solid HDPE, but the quantities evolved can be significantly reduced by vacuum baking at 368 K for a few hours prior to device assembly.

Dinh, L N; Sze, J; Schildbach, M A; Chinn, S C; Maxwell, R S; Raboin, P; McLean II, W

2008-08-11

234

Immobilization of silver nanoparticles on polyethylene terephthalate  

PubMed Central

Two different procedures of grafting with silver nanoparticles (AgNP) of polyethylene terephthalate (PET), activated by plasma treatment, are studied. In the first procedure, the PET foil was grafted with biphenyl-4,4?-dithiol and subsequently with silver nanoparticles. In the second one, the PET foil was grafted with silver nanoparticles previously coated with the same dithiol. X-ray photoelectron spectroscopy and electrokinetic analysis were used for characterization of the polymer surface at different modification steps. Silver nanoparticles were characterized by ultraviolet-visible spectroscopy and by transmission electron microscopy (TEM). The first procedure was found to be more effective. It was proved that the dithiol was chemically bonded to the surface of the plasma-activated PET and that it mediates subsequent grafting of the silver nanoparticles. AgNP previously coated by dithiol bonded to the PET surface much less. PMID:24994960

2014-01-01

235

Electron dynamics of shocked polyethylene crystal  

NASA Astrophysics Data System (ADS)

Electron force field (eFF) wave-packet molecular-dynamics simulations of the single shock Hugoniot are reported for a crystalline polyethylene (PE) model. The eFF results are in good agreement with previous density-functional theories and experimental data, which are available up to 80 GPa. We predict shock Hugoniots for PE up to 350 GPa. In addition, we analyze the structural transformations that occur due to heating. Our analysis includes ionization fraction, molecular decomposition, and electrical conductivity during isotropic compression. We find that above a compression of 2.4 g/cm3, the PE structure transforms into an atomic fluid, leading to a sharp increase in electron ionization and a significant increase in system conductivity. eFF accurately reproduces shock pressures and temperatures for PE along the single shock Hugoniot.

Theofanis, Patrick L.; Jaramillo-Botero, Andres; Goddard, William A., III; Mattsson, Thomas R.; Thompson, Aidan P.

2012-03-01

236

Myocardial matrix-polyethylene glycol hybrid hydrogels for tissue engineering  

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

237

Infection of a porous polyethylene orbital implant with Capnocytophaga.  

PubMed

A 68-year-old woman experienced an infection of a porous polyethylene orbital implant caused by Capnocytophaga after a dental procedure. The infection was unresponsive to both topical and oral antibiotics and required removal of the porous polyethylene orbital implant. Capnocytophaga is a capnophilic, gram-negative bacillus. Capnocytophaga is a normal commensal of the mouth and is responsible for both gingivitis and periodontal disease. Capnocytophaga is a rare cause of ocular infections. This is the first reported patient with an infection of a porous polyethylene orbital implant caused by Capnocytophaga. The authors believe infected integrated orbital implants must be removed because neither topical or systemic therapy provide effective treatment. PMID:9842559

Wilson, M W; Wobig, J L; Dailey, R A

1998-11-01

238

Enzymes for the biofunctionalization of poly(ethylene terephthalate).  

PubMed

The functionalization of synthetic polymers such as poly(ethylene terephthalate) to improve their hydrophilicity can be achieved biocatalytically using hydrolytic enzymes. A number of cutinases, lipases, and esterases active on polyethylene terephthalate have been identified and characterized. Enzymes from Fusarium solani, Thermomyces insolens, T. lanuginosus, Aspergillus oryzae, Pseudomonas mendocina, and Thermobifida fusca have been studied in detail. Thermostable biocatalysts hydrolyzing poly(ethylene terephthalate) are promising candidates for the further optimization of suitable biofunctionalization processes for textile finishing, technical, and biomedical applications. PMID:21076908

Zimmermann, Wolfgang; Billig, Susan

2011-01-01

239

Alumina Ceramic against Polyethylene: A long term follow up  

Microsoft Academic Search

\\u000a Between 1978 and 1990 the femoral implant was the same in four groups of patients with different function couples: alumina\\/alumina,\\u000a (AL\\/AL); alumina\\/ polyethylene (AL\\/PE); metal\\/polyethylene (Me\\/PE); zirconia\\/polyethylene (Zir\\/ PE). The aim of this study\\u000a was to compare survival rate, wear and femoral osteolysis among different couples of friction in patients with the same femoral\\u000a stem.\\u000a \\u000a \\u000a For comparison between AL\\/AL and

Ph. Hernigou; A. Nogier; A. Poignard; P. Filippini

240

Silica Supported Single-Walled Carbon Nanotubes as a Modifier in Polyethylene Composites  

E-print Network

Silica Supported Single-Walled Carbon Nanotubes as a Modifier in Polyethylene Composites Neal D. Mc.interscience.wiley.com). ABSTRACT: Composites have been made from single- wall carbon nanotubes in a polyethylene (PE) matrix: additives; composites; conducting polymers; nanocomposites; polyethylene INTRODUCTION Polyethylene (PE

Resasco, Daniel

241

Quantification of branching in model 3-arm star polyethylene Ramnath Ramachandran, Gregory Beaucage*  

E-print Network

1 Quantification of branching in model 3-arm star polyethylene Ramnath Ramachandran, Gregory-arm star polyethylene molecules is presented. Many commercial polyethylenes have long side branches-density polyethylene (LDPE) is typically a highly branched structure with broad distributions in branch content, branch

Beaucage, Gregory

242

High-Molecular-Weight Polyethylene Glycol Prevents Lethal Sepsis Due to Intestinal Pseudomonas aeruginosa  

E-print Network

High-Molecular-Weight Polyethylene Glycol Prevents Lethal Sepsis Due to Intestinal Pseudomonas of this study were to test the ability of a high-molecular- weight polyethylene glycol compound, polyethylene: The ability of polyethylene glycol 15­20 to protect the intestinal epi- thelium against the opportunistic

Lee, Ka Yee C.

243

Western blot membrane composed of electrospun polyvinylidene fluoride nanofiber membrane and polyethylene terephthalate sheet.  

PubMed

In a previous study, an electrospun polyvinylidene fluoride (PVDF) nanofiber membrane was developed for Western blotting. The membrane exhibited high sensitivity and high binding capacity for the detection of protein bands that was unlike that observed for conventional, microphase separation-based porous PVDF membranes. Nevertheless, the PVDF nanofiber membrane is quite expensive. The objective of this study was to develop an economical Western blot membrane using a hybrid electrospun PVDF nanofiber and polyethylene terephthalate (PET) sheet. The results showed that the detection sensitivity of the 4 gram per square meter (gsm) membrane was similar to those of the electrospun PVDF nanofiber membrane only, and the 7 gsm PVDF nanofiber membranes on a PET sheet and the electrospun PVDF nanofiber membrane. This means the protein detection sensitivity is not proportional to the thickness of the PVDF nanofiber membrane. The 4 gsm PVDF nanofiber membrane on a PET sheet can be used to detect proteins with high sensitivity and economic efficiency. PMID:23862502

Cho, Eugene; Kim, Chan; Hwang, Cheol Ho; Chang, Duck Rye; Kook, Joong-Ki

2013-06-01

244

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...

245

75 FR 53711 - Polyethylene Terephthalate (PET) Film From Korea  

Federal Register 2010, 2011, 2012, 2013, 2014

...Polyethylene Terephthalate (PET) Film From Korea AGENCY: United States International...concerning the antidumping duty order on PET film from Korea...revocation of the antidumping duty order on PET film from Korea would be likely to lead to...

2010-09-01

246

Polyethylene/Boron Composites for Radiation Shielding Applications  

SciTech Connect

Multifunctional composites made with boron are absorbers of low energy nuetrons, and could be used for structural shielding materials. Polyethylene/boron carbide composites were fabricated using conventional polymer processing techniques, and were evaluated for mechanical and radiation shielding properties. Addition of neat boron carbide (powder and nanoparticles) to an injection molding grade HPDE showed superior mechanical properties compared to neat HDPE. Radiation shielding measurements of a 2 wt% boron carbide composite were improved over those of the neat polyethylene.

Harrison, Courtney; Grulke, Eric [Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506 (United States); Burgett, Eric; Hertel, Nolan [Neely Nuclear Research Center, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2008-01-21

247

CORROSION CONTROL OF DUCTILE IRON PIPE WITH POLYETHYLENE ENCASEMENT  

Microsoft Academic Search

This paper covers the history, research, development and performance of polyethylene encasement as a corrosion control measure for Cast and Ductile Iron pipe. We will review the research leading to the adoption of the American Water Works Association (AWWA) Standard for Polyethylene Encasement for Ductile-Iron Pipe Systems (ANSI\\/AWWA C105\\/A21.5) in 1972. The paper also includes a discussion of the AWWA

Normand De Agostinis

248

Polyethylene/Boron Composites for Radiation Shielding Applications  

NASA Astrophysics Data System (ADS)

Multifunctional composites made with boron are absorbers of low energy nuetrons, and could be used for structural shielding materials. Polyethylene/boron carbide composites were fabricated using conventional polymer processing techniques, and were evaluated for mechanical and radiation shielding properties. Addition of neat boron carbide (powder and nanoparticles) to an injection molding grade HPDE showed superior mechanical properties compared to neat HDPE. Radiation shielding measurements of a 2 wt% boron carbide composite were improved over those of the neat polyethylene.

Harrison, Courtney; Burgett, Eric; Hertel, Nolan; Grulke, Eric

2008-01-01

249

Highly Enriched Uranium Metal Annuli and Cylinders with Polyethylene Reflectors and/or Internal Polyethylene Moderator  

SciTech Connect

A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, experiments of uranium metal annuli with and without polyethylene reflectors and with the central void region either empty or filled with polyethylene were evaluated under ICSBEP Identifier HEU-MET-FAST-076. The outer diameter of the uranium annuli varied from 9 to 15 inches in two-inch increments. In addition, there were uranium metal cylinders with diameters varying from 7 to 15 inches with complete reflection and reflection on one flat surface to simulate floor reflection. Most of the experiments were performed between February 1964 and April 1964. Five partially reflected (reflected on the top only) experiments were assembled in November 1967, but are judged by the evaluators not to be of benchmark quality. Twenty-four of the twenty-five experiments have been determined to have fast spectra. The only exception has a mixed spectrum. Analyses were performed in which uncertainty associated with five different parameters associated with the uranium parts and three associated with the polyethylene parts was evaluated. Included were uranium mass, height, diameter, isotopic content, and impurity content and polyethylene mass, diameter, and impurity content. There were additional uncertainties associated with assembly alignment, support structure, and the value for ßeff. In addition to the idealizations made by the experimenters (removal of a diaphragm), a few simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. Simplifications included omission of the support structure, possible surrounding equipment, and the walls, floor, and ceiling of the experimental cell. Bias values that result from these simplifications were determined and associated uncertainty in the bias values were included in the overall uncertainty in benchmark keff values. Bias values ranged from 0.0002 ?k to 0.0093 ?k below the experimental value. Overall uncertainties range from ? 0.0002 to ? 0.0011. Major contributors to the overall uncertainty include uncertainty in the support structure and the polyethylene parts. A comparison of experimental, benchmark-model, and MCNP-model keff values is shown in Figure 1. The experimental keff values are derived from the original reactivities reported by the principal experimentalist. The benchmark-model keff values are the experimental keff values adjusted to account for biases that were introduced by removing the support structure and surroundings. The MCNP-model keff values are simply the values found from MCNP calculations using the benchmark specifications and ENDF/B-VI cross-section data. Figure 1. Comparison of Experimental, Benchmark-Model and MCNP-Model keff value. Calculated results for most of the experiments are

Tyler Sumner; J. Blair Briggs; Leland Montierth

2007-05-01

250

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

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 ...

Yazdani, Iman

2007-01-01

251

Fatigue crack propagation resistance of highly crosslinked polyethylene.  

PubMed

A higher degree of cross-linking has been shown to improve wear properties of ultra-high molecular weight polyethylene in laboratory studies. However, cross-linking can also affect the mechanical properties of ultra-high molecular weight polyethylene. Fatigue crack propagation resistance was determined for electron beam cross-linked ultra-high molecular weight polyethylene and compared with gamma irradiation cross-linked and noncross-linked polyethylene fatigue specimens. Crosslinking was done with different dosages of irradiation followed by melting. For one irradiation dose (50 kGy) extrusion and molding processes were compared. A fracture mechanics approach was used to determine how the degree of cross-linking affects resistance to crack propagation in ultra-high molecular weight polyethylene. Fatigue crack propagation resistance was reduced in proportion to the irradiation dose. The type of irradiation (gamma or electron beam) or manufacturing method (extrusion or molding) did not affect fatigue crack propagation resistance. The reduced fatigue strength of highly cross-linked ultra-high molecular weight polyethylene could lead to mechanical failure in conditions that are associated with cyclic local tensile stresses. PMID:15577468

Bradford, Letitia; Baker, David; Ries, Michael D; Pruitt, Lisa A

2004-12-01

252

Tribological characteristics of polyethylene glycol (PEG) as a lubricant for wear resistance of ultra-high-molecular-weight polyethylene (UHMWPE ) in artificial knee join.  

PubMed

For the longevity of total knee joint prostheses, we have developed an artificial lubricant using polyethylene glycol (PEG) for the prevention of wear of ultra-high-molecular-weight polyethylene (UHMWPE). In the present study, the lubricative function of this PEG lubricant was evaluated by a wear test using Co-Cr alloy and UHMWPE counter surface samples. As a result, human synovial fluid including the PEG lubricant showed good result regarding the wear volume and a worn surface of UHMWPE. Considering its lubrication mechanism, it is suspected that interaction between the PEG molecules and the proteins in synovial fluid was involved. Since PE molecules are also organic compounds having a hydroxyl group at one or both ends, the albumin and PEG molecule complex would have bound more strongly to the metal oxide surface and UHMWPE surfaces might enhance and stabilize the lubricating film between the contact surfaces under the boundary lubrication. This study suggests that PEG lubricant as an intra-articular viscous supplement has the potential to prevent wear of UHMWPE by mixing with synovial fluid and to contribute to the longevity of knee joint prostheses. PMID:25016174

Kobayashi, Masanori; Koide, Takayuki; Hyon, Suong-Hyu

2014-10-01

253

Reinforcing Poly(ethylene) with Cellulose Nanocrystals.  

PubMed

The fabrication of nanocomposites of low-density polyethylene (LDPE), one of the world's most widely used polymers, and cellulose nanocrystals (CNCs), which represent the world's most abundant bio-based nanofiller, is reported. While the hydrophobic polymer and the hydrophilic filler seem to be intrinsically incompatible, this article shows that it is possible to kinetically trap homogeneous nanocomposites by a templating approach. An organogel is first prepared by exchanging the solvent of an aqueous CNC dispersion against acetone, impregnating the resulting organogel, in which the CNCs form a percolating network with a hot LDPE solution in toluene, and compression-molding the resulting materials into thin films. At a filler content of 7.6% v/v, the resulting materials display a three- to four-fold increase in strength and stiffness compared with the neat LDPE, which confirms that the CNC network could be largely maintained. It is also possible to reprocess these nanocomposites and dilute them with LDPE using conventional melt-processing techniques. PMID:25204424

Sapkota, Janak; Jorfi, Mehdi; Weder, Christoph; Foster, Earl Johan

2014-09-10

254

Exciton self-trapping in bulk polyethylene  

E-print Network

We studied theoretically the behavior of an injected electron-hole pair in crystalline polyethylene. Time-dependent adiabatic evolution by ab-initio molecular dynamics simulations show that the pair will become self-trapped in the perfect crystal, with a trapping energy of about 0.38 eV, with formation of a pair of trans-gauche conformational defects, three C$_2$H$_4$ units apart on the same chain. The electron is confined in the inter-chain pocket created by a local, 120$^\\circ$ rotation of the chain between the two defects, while the hole resides on the chain and is much less bound. Despite the large energy stored in the trapped excitation, there does not appear to be a direct non-radiative channel for electron-hole recombination. This suggests that intrinsic self-trapping of electron-hole pairs inside the ideal quasi-crystalline fraction of PE might not be directly relevant for electrical damage in high-voltage cables.

D. Ceresoli; M. C. Righi; E. Tosatti; S. Scandolo; G. Santoro; S. Serra

2005-07-13

255

Polarimetric studies of polyethylene terephtalate flexible substrates  

NASA Astrophysics Data System (ADS)

Polymer sheets are currently used worldwide in a wide range of applications. The manufacturing process of these sheets involves extruding machines that stretch the material in both lateral and longitudinal directions with respect to the machine direction, thus inducing birefringence. In most cases, the film obtained is optically biaxial. Polarimetric spectroscopy (Ellipsometry and Mueller Matrix) combined with conoscopic observation are the methods of choice to study these properties. In this work we report an analysis of commercially available polyethylene terephtalate (PET) films used as substrate for food packaging as well as for embedded electronic devices such as solar cells or flexible displays. Initial observation of these films through polarizing microscope in conoscopic mode reveals first the trace of optical axis plane with respect to the film surface and second, whether the optical axis is acute or not. This preliminary study allows optimal sample positioning for further polarimetric studies. The measurements and modelling are done in both reflection and transmission mode on several spectroscopic polarimetric setups from UV to NIR. The models give as a main result, the dielectric tensor of the film as well as its orientation with respect to the laboratory reference frame.

Stchakovsky, M.; Garcia-Caurel, E.; Warenghem, M.

2008-12-01

256

Application of In Situ Microfibrillization to Recycling Ultraviolet?Aged Poly(Ethylene Terephthalate) (PET) and High Density Polyethylene (HDPE)  

Microsoft Academic Search

The potential of in situ microfibrillization for recycling ultraviolet?aged high density polyethylene (HDPE) and poly(ethylene terephthalate) (PET) mixtures was investigated. The photodegradation of HDPE and PET was conducted through accelerated irradiation in an ultraviolet (UV) chamber. The ultraviolet?aged HDPE and PET was melt blended (in 80\\/20 wt. ratio) and rectangular slit die extruded, followed by hot stretch and quenching; thus the

2007-01-01

257

UV stability and radiation-crosslinking of linear low density polyethylene and low density polyethylene for greenhouse applications  

Microsoft Academic Search

Ultraviolet (UV) radiation stability and ?-radiation crosslinking of linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) for greenhouse film applications was investigated. Various combinations of primary antioxidant (i.e. Irganox 1010), secondary antioxidant (i.e. Irgafos 168), UV absorber (i.e. Chimassorb 81) and hindered amine light stabilizer (HALS) were used to prepare thin PE films (60 ?m thick). The films

Ahmed A Basfar; K. M Idriss Ali; S. M Mofti

2003-01-01

258

Natural weathering test for films of various formulations of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE)  

Microsoft Academic Search

Natural (outdoor) weathering test was performed to investigate the UV stability of thin films (0.06mm) of linear low density polyethylene (LLDPE) and low density polyethylene (LDPE). The PE films were prepared from various formulations of LLDPE and LDPE resins. Some of these films contained a single high molecular mass HALS only, along with a primary antioxidant (i.e. Irganox 1010) and

A. A. Basfar; K. M. Idriss Ali

2006-01-01

259

Engineering Poly(ethylene glycol) Materials to Promote Cardiogenesis  

NASA Astrophysics Data System (ADS)

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.

Smith, Amanda Walker

260

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

Code of Federal Regulations, 2014 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2014-07-01

261

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

Code of Federal Regulations, 2011 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and...

2011-07-01

262

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

Code of Federal Regulations, 2012 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2012-07-01

263

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

Code of Federal Regulations, 2013 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2013-07-01

264

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

Code of Federal Regulations, 2010 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and...

2010-07-01

265

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

NASA Astrophysics Data System (ADS)

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.

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

266

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

PubMed

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

Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood

2015-03-30

267

Wear of highly crosslinked polyethylene acetabular components.  

PubMed

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

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

2015-04-01

268

Lubricin: A versatile, biological anti-adhesive with properties comparable to polyethylene glycol.  

PubMed

Lubricin is a glycoprotein found in articular joints which has been recognized as being an important biological boundary lubricant molecule. Besides providing lubrication, we demonstrate, using a quartz crystal microbalance, that lubricin also exhibits anti-adhesive properties and is highly effective at preventing the non-specific adsorption of representative globular proteins and constituents of blood plasma. This impressive anti-adhesive property, combined with lubricin's ability to readily self-assemble to form dense, highly stable telechelic polymer brush layers on virtually any substrates, and its innate biocompatibility, makes it an attractive candidate for anti-adhesive and anti-fouling coatings. We show that coatings of lubricin protein are as effective as, or better than, self-assembled monolayers of polyethylene glycol over a wide range of pH and that this provides a simple, versatile, highly stable, and highly effective method of controlling unwanted adhesion to surfaces. PMID:25890713

Greene, George W; Martin, Lisandra L; Tabor, Rico F; Michalczyk, Agnes; Ackland, Leigh M; Horn, Roger

2015-06-01

269

Friction and wear of hydroxyapatite reinforced high density polyethylene against the stainless steel counterface.  

PubMed

Hydroxyapatite (HA) reinforced high density polyethylene (HDPE) was invented as a biomaterial for skeletal applications. In this investigation, tribological properties (e.g. wear rate and coefficient of friction) of unfilled HDPE and HA/HDPE composites were evaluated against the duplex stainless steel in dry and lubricated conditions, with distilled water or aqueous solutions of proteins (egg albumen or glucose) being lubricants. Wear tests were conducted in a custom-built test rig for HDPE and HA/HDPE containing up to 40 vol % of HA. It was found that HA/HDPE composites had lower coefficients of friction than unfilled HDPE under certain conditions. HA/HDPE also exhibited less severe fatigue failure marks than HDPE. The degradation and fatigue failure of HDPE due to the presence of proteins were severe for low speed wear testing (100 rpm) as compared to high speed wear testing (200 rpm). This was due possibly to the high shear rate at the contact which could remove any degraded film instantaneously at high sliding speed, while with a low sliding speed the build-up of a degraded layer of protein could occur. The degraded protein layer would stay at the contact for a longer time and mechanical activation would induce adverse reactions, weakening the surface layer of HDPE. Both egg albumen and glucose were found to be corrosive to steel and adversely reactive for HDPE and HA/HDPE composites. The wear modes observed were similar to that of ultra-high molecular weight polyethylene. Specimens tested with egg albumen also displayed higher wear rates, which was again attributed to corrosion accelerated wear. PMID:15348592

Wang, M; Chandrasekaran, M; Bonfield, W

2002-06-01

270

Modeling uptake of hydrophobic organic contaminants into polyethylene passive samplers.  

PubMed

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

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

2015-02-17

271

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

...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...

2010-12-03

272

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-549-821] Polyethylene Retail Carrier Bags From Thailand...weighted-average duty margin for polyethylene retail carrier bags (PRCBs) from...2\\ See Polyethylene Retail Carrier Bags from...

2013-11-21

273

Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function of Crystallinity in the Presence of the  

E-print Network

Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function: In this study, the friction and wear behavior of ultrahigh molecular weight polyethylene (UHMWPE) were evaluated Words: ultrahigh molecular weight polyethylene (UHMWPE), crystallinity, friction, wear, phospholipid

Lin, Zhiqun

274

75 FR 16431 - Polyethylene Retail Carrier Bags From Indonesia: Final Determination of Sales at Less Than Fair...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Polyethylene Retail Carrier Bags From Indonesia: Final Determination of Sales at Less...polyethylene retail carrier bags (PRCBs) from Indonesia are being, or are likely to be, sold...Polyethylene Retail Carrier Bags from Indonesia: Preliminary Determination of...

2010-04-01

275

Initial Stages of Pyrolysis of Polyethylene  

NASA Astrophysics Data System (ADS)

Combustion and flammability of plastics are important topics of practical interest directly related to fire safety and recycling of polymeric materials; pyrolysis of the solid is the initial step of its combustion. One of the main ways to study such complicated processes is through detailed mechanistic modeling, in which the process is represented by a set of many elementary reactions. Mechanistic modeling of combustion of plastics is considerably hindered by the lack of necessary kinetic data. In virtually all existing models of polymer pyrolysis the majority of kinetic data used are derived from the corresponding gas phase values of smaller species. The use of gas phase rate constants is, generally, not justified without an experimental justification. In the first part of the work the influence of condensed phase on the rate of scission of a carbon-carbon bond (the reaction that initiates pyrolysis and combustion) in polyethylene (PE) was studied using the method of Reactive Molecular Dynamics (RMD). A method based on a two-step kinetic mechanism was developed to decouple the cage effect from the kinetics of the reaction under study. It was observed that under the conditions of condensed phase the rate constant of C-C bond scission in PE decreased by an order of magnitude compared to that obtained in vacuum. It was also shown that under the conditions of polymer melt the rate constant does not depend on the length of the polymer chain. In the second part of the work the kinetics of liquid phase and gas phase products of PE pyrolysis were studied experimentally using Gas Chromatography and Nuclear Magnetic Resonance. Based on the assumption of applicability of gas phase kinetic data for C-C scission reaction and beta-scission reaction under the conditions of polymer melt, rate constants of hydrogen transfer, radical addition to double bonds, and radical recombination were determined via kinetic modeling of the experimental results. The obtained values of the rate constants were found to be in reasonable agreement with the constants of similar reactions of smaller molecules in the gas phase.

Popov, Konstantin V.

276

Injectable silk-polyethylene glycol hydrogels.  

PubMed

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

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

2015-01-01

277

Hydration of polyethylene glycol-grafted liposomes.  

PubMed Central

This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase of the samples decrease. This reflects the increase in hydration of the lipid headgroup region (up to five additional water molecules per lipid molecule for 12 mol % PEG-lipid) and the weakening of the bilayer packing due to the lateral repulsion of PEG chains. PMID:9512033

Tirosh, O; Barenholz, Y; Katzhendler, J; Priev, A

1998-01-01

278

Molecular Weight Dependence of the Viscosity of Polyethylene Macrocycles  

NASA Astrophysics Data System (ADS)

The Grubbs group at Caltech is using a new method of synthesis for the production of macrocycles that avoids the problems of sample contamination with long chain linear molecules. They have produced macrocyclic polyethylenes having molecular weights as high as 400,000 g/mole. At Texas Tech University rheological measurements are being made using both the Plazek Magnetic Bearing Torsional Creep Apparatus and a Paar Physica controlled stress rheometer. Because the samples are polydisperse, with Mw/Mn values of 1.6-1-9, we here report only the results of the viscosity as a function of molecular weight. Surprisingly, unlike reports in the literature for polystyrene rings or polybutadiene rings, the viscosities of the polyethylene rings are larger than those for equivalent molecular weight linear polyethylenes and the viscosity increases approximately exponentially with weight average molecular weight. Further results will be reported at the meeting.

Wang, Jian; McKenna, Gregory; Benitez, Diego; Gorodetskaya, Irina; Grubbs, Robert

2005-03-01

279

Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles  

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

280

Radiation Transport Properties of Polyethylene-Fiber Composites  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

281

Space radiation transport properties of polyethylene-based composites  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

282

Molecularly uniform poly(ethylene glycol) certified reference material  

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

283

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2011-05-06

284

Coextruded Polyethylene and Wood-Flour Composite: Effect of Shell Thickness, Wood Loading, and Core  

E-print Network

Coextruded Polyethylene and Wood-Flour Composite: Effect of Shell Thickness, Wood Loading, and Core recycled polyethylene and wood-flour composites with core­shell structure were manufactured using a pilot

285

Synthesis and elaboration of polyethylene surfaces modified via anionic grafting chemistry  

E-print Network

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...

Bandella, Ashok Krishangopal

1996-01-01

286

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

E-print Network

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

Gruner, Sol M.

287

Hyperbranched Fluoropolymer and Linear Poly(ethylene glycol) Based Amphiphilic Crosslinked Networks as Efficient  

E-print Network

Hyperbranched Fluoropolymer and Linear Poly(ethylene glycol) Based Amphiphilic Crosslinked Networks and crosslinking of mixtures of hyperbranched fluoropolymer (HBFP) and diamino-terminated poly(ethylene glycol 42: 6193­6208, 2004 Keywords: hyperbranched polymers; amphiphiles; crosslinking; fluoropolymers; poly

Greenlief, C. Michael

288

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

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...Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). The...

2012-12-07

289

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

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2011-05-27

290

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of...administrative review of polyethylene terephthalate film, sheet and strip (PET Film) from India for Ester Industries Ltd....

2011-12-09

291

76 FR 58248 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, In Part, of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission...CVD) order on polyethylene terephthalate film, sheet and strip from India covering the...Garware Polyester Ltd., Jindal Poly Films Limited of India, Polyplex...

2011-09-20

292

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

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...Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). This...

2011-12-07

293

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

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2011-07-18

294

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

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Partial...AD) order on polyethylene terephthalate film, sheet and strip from India covering the...SRF Limited (SRF), and Jindal Poly Films Limited of India (Jindal).\\3\\...

2013-01-11

295

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

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824, C-533-825] Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping...duty (CVD) orders on Polyethylene Terephthalate Film, Sheet and Strip (PET Film) from India. The Department determines that...

2010-03-09

296

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

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...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2012-12-10

297

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...administrative review of polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2012-03-12

298

76 FR 27005 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Initiation and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea...antidumping duty order on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of Korea (Korea) pursuant...

2011-05-10

299

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Second Review)] Polyethylene Terephthalate Film, Sheet, and Strip From India and Taiwan; Notice...countervailing duty order on polyethylene terephthalate film, sheet, and strip (``PET'' film) from India and the antidumping duty orders...

2013-07-15

300

75 FR 75172 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-351-841] Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil for the period November 6,...

2010-12-02

301

75 FR 81570 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from India in response to a request from SRF...

2010-12-28

302

76 FR 9753 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Final...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2011-02-22

303

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). The...

2013-12-24

304

78 FR 45512 - Polyethylene Terephthalate Film from India and Taiwan: Extension of Time Limits for Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824, A-583-837] Polyethylene Terephthalate Film from India and Taiwan: Extension of Time Limits for...antidumping duty (AD) orders on polyethylene terephthalate film (PET Film) from India and Taiwan, pursuant to section...

2013-07-29

305

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

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...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...administrative review of polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2011-10-03

306

76 FR 47546 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from India. This review covers one...

2011-08-05

307

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-520-803] Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab Emirates (UAE). This...

2010-12-17

308

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

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India: Final Results...duty order on polyethylene terephthalate (PET) film, sheet, and strip (``PET film'') from India. The Department finds that...

2013-08-05

309

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

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...Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan; Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan. The period of review (POR)...

2013-08-09

310

75 FR 49900 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-351-841] Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative review...

2010-08-16

311

78 FR 60311 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, China, and the United Arab...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Review)] Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, China...polyethylene terephthalate (``PET'') film, sheet, and strip from Brazil, China...antidumping duty orders on imports of PET film from Brazil, China, and the United...

2013-10-01

312

77 FR 3730 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping...  

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...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission...AD) order on polyethylene terephthalate film, sheet and strip from India covering the...Polyester Ltd. (Garware), Jindal Poly Films Limited of India (Jindal),...

2012-01-25

313

76 FR 18519 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Amended Final Results of...  

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...Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Amended Final...administrative review of polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan.\\1\\ The period of review...

2011-04-04

314

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

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...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2013-12-30

315

76 FR 58244 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission...AD) order on polyethylene terephthalate film, sheet and strip from India covering the...Garware Polyester Ltd., Jindal Poly Films Limited of India, Polyplex...

2011-09-20

316

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from the Republic of Korea. Pursuant to...

2011-09-16

317

78 FR 9668 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping...antidumping duty order on polyethylene terephthalate film (PET Film) from Taiwan.\\1\\ This review covers two...

2013-02-11

318

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

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary...CVD) order on polyethylene terephthalate film, sheet and strip from India covering the...Polyester Ltd. (Garware), Jindal Poly Films Limited of India (Jindal),...

2012-02-21

319

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...duty (CVD) order on polyethylene terephthalate film, sheet and strip (PET film) from India in response to a request from SRF...

2010-12-28

320

76 FR 76943 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Antidumping...antidumping duty order on polyethylene terephthalate film (PET Film) from India.\\1\\ This review covers one...

2011-12-09

321

75 FR 6634 - Polyethylene Terephthalate Film, Sheet, and Strip from India: Final Results of Countervailing...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip from India: Final Results of...countervailing duty order on polyethylene terephthalate film, sheet, and strip (PET film) from India for the period January 1, 2007...

2010-02-10

322

77 FR 46704 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from Taiwan. The period of review (POR)...

2012-08-06

323

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of...new shipper review of polyethylene terephthalate film, sheet and strip (PET Film) from India for SRF Limited (SRF), covering...

2011-05-27

324

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2013-06-12

325

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...duty (CVD) order on polyethylene terephthalate film, sheet and strip (PET film) from India for the period of review (POR)...

2013-08-07

326

76 FR 72676 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-351-841] Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil for the period November 1, 2009...

2011-11-25

327

76 FR 76941 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-837] Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of...antidumping duty order on polyethylene terephthalate film, sheet and strip (PET Film) from Taiwan. The period of review (POR)...

2011-12-09

328

76 FR 47558 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of...  

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...Administration [C-533-825] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...duty (CVD) order on polyethylene terephthalate film, sheet and strip (PET Film) from India. This review covers one...

2011-08-05

329

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Administrative...antidumping duty order on polyethylene terephthalate film (PET Film) from India.\\1\\ This review covers three...

2013-02-11

330

76 FR 48122 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-351-841] Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative review...

2011-08-08

331

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

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission...CVD) order on polyethylene terephthalate film, sheet and strip from India covering the...Polyester Ltd. (Garware), Jindal Poly Films Limited of India (Jindal),...

2012-04-02

332

77 FR 1668 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission...CVD) order on polyethylene terephthalate film, sheet and strip from India covering the...Polyester Ltd. (Garware), Jindal Poly Films Limited of India (Jindal),...

2012-01-11

333

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-924] Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic...antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from the People's Republic of...

2013-12-26

334

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Circumstances Review: Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea AGENCY...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Korea, effective as of the date of...

2011-08-15

335

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-533-824] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from India. The period of review (POR) is...

2013-08-07

336

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-807] Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Final Results of...antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET film) from Korea, covering the June 1, 2009, to...

2011-11-18

337

78 FR 2369 - Polyethylene Terephthalate Film, Sheet and Strip From India: Partial Rescission of Countervailing...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-825] Polyethylene Terephthalate Film, Sheet and Strip From India: Partial...CVD) order on polyethylene terephthalate film, sheet and strip from India covering the...SRF Limited (SRF), and Jindal Poly Films Limited of India (Jindal). The...

2013-01-11

338

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

Federal Register 2010, 2011, 2012, 2013, 2014

...A-533-824, A-583-837] Polyethylene Terephthalate Film, Sheet and Strip From India and Taiwan: Preliminary...antidumping duty orders on Polyethylene Terephthalate Film, Sheet and Strip (``PET Film'') from India and Taiwan. The Department...

2013-11-08

339

Divinyl-End-Functionalized Polyethylenes: Ready Access to a Range of Telechelic Polyethylenes through Thiol-Ene Reactions.  

PubMed

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

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

2015-04-01

340

Complement activation on poly(ethylene oxide)-like RFGD-deposited surfaces  

PubMed Central

Non-specific protein adsorption, particularly fibrinogen (Fg), is thought to be an initiating step in the foreign body response (FBR) to biomaterials by promoting phagocyte attachment. In previous studies, we therefore prepared radio frequency glow discharge (RFGD) polyethylene oxide (PEO)-like tetraglyme coatings (CH3O(CH2CH2O)4CH3) adsorbing less than 10 ng/cm2 Fg and showed that they had the expected low monocyte adhesion in vitro. However, when these were implanted in vivo, many adherent inflammatory cells and a fibrous capsule were found, suggesting the role of alternative proteins, such as activated complement proteins, in the FBR to these materials. We therefore investigated complement interactions with the tetraglyme surfaces. First, because of its well known role in complement C3 activation, we measured the hydroxyl group (-OH) content of tetraglyme, but found it to be very low. Second, we measured C3 adsorption to tetraglyme from plasma. Low amounts of C3 adsorbed on tetraglyme, though it displayed higher binding strength than the control surfaces. Finally, complement activation was determined by measuring C3a and SC5b-9 levels in serum after incubating with tetraglyme, as well as other surfaces that served as positive and negative controls, namely poly(vinyl alcohol) hydrogels, Silastic sheeting, and poly(ethylene glycol) self-assembled monolayers with different end groups. Despite displaying low hydroxyl group concentration, relatively high C3a and SC5b-9 levels were found in serum exposed to tetraglyme, similar to the values due to our positive control, PVA. Our results support the conclusion that complement activation by tetraglyme is a possible mechanism involved in the FBR to these biomaterials. PMID:21105163

Szott, Luisa Mayorga; Stein, M. Jeanette; Ratner, Buddy D.; Horbett, Thomas A.

2010-01-01

341

Preventing corona effects: multi-phosphonic acid poly(ethylene glycol) copolymers for stable stealth iron oxide nanoparticles  

E-print Network

When disperse in biological fluids, engineered nanoparticles are selectively coated with proteins, resulting in the formation of a protein corona. It is suggested that the protein corona is critical in regulating the conditions of entry into the cytoplasm of living cells. Recent reports describe this phenomenon as ubiquitous and independent of the nature of the particle. For nanomedicine applications however, there is a need to design advanced and cost-effective coatings that are resistant to protein adsorption and that increase the biodistribution in vivo. In this study, phosphonic acid poly(ethylene glycol) copolymers were synthesized and used to coat iron oxide particles. The copolymer composition was optimized to provide simple and scalable protocols as well as long-term stability in culture media. It is shown that polymers with multiple phosphonic acid functionalities and PEG chains outperform other types of coating, including ligands, polyelectrolytes and carboxylic acid functionalized PEG. PEGylated pa...

Torrisi, V; Vitorazi, L; Crouzet, Q; Marletta, G; Loubat, C; Berret, J -F

2014-01-01

342

Transport and structural characteristics of crosslinked poly(ethylene oxide) rubbers  

Microsoft Academic Search

Three series of crosslinked poly(ethylene oxide) rubbers have been prepared by photopolymerization of prepolymer solutions containing: (1) poly(ethylene glycol) diacrylate (PEGDA) and H2O, (2) PEGDA and poly(ethylene glycol) methyl ether acrylate (PEGMEA), and (3) PEGDA and poly(ethylene glycol) acrylate (PEGA). All of these polymers have similar chemical composition (approximately 82wt.% ethylene oxide), but the crosslink density and the content and

Haiqing Lin; Elizabeth Van Wagner; John S. Swinnea; Benny D. Freeman; Steven J. Pas; Anita J. Hill; Sumod Kalakkunnath; Douglass S. Kalika

2006-01-01

343

Effects of crosslinking byproducts on space charge formation in crosslinked polyethylene  

Microsoft Academic Search

Space charge is formed in cables insulated with crosslinked polyethylene. It has not been clear whether the crosslinking byproducts or the crosslinked polymer morphology is responsible for the space charge formation. In order to clarify this point additive-free noncrosslinked low-density polyethylene, additive-free crosslinked polyethylene, and degassed crosslinked polyethylene were soaked in the crosslinking byproducts and the space charge distribution was

Yasumasa Maeno; Naoshi Hirai; Yoshimichi Ohki; Toshikatsu Tanaka; Minoru Okashita; Takashi Maeno

2005-01-01

344

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

DOEpatents

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.

Salyer, Ival O. (Dayton, OH)

1987-01-01

345

Conformation of Poly(ethylene oxide)-Hydroxybenzene Molecular Complexes Studied by Solid-State NMR  

E-print Network

Conformation of Poly(ethylene oxide)-Hydroxybenzene Molecular Complexes Studied by Solid-State NMR February 16, 2000 ABSTRACT: The conformation of poly(ethylene oxide), PEO, in molecular complexes. Introduction Poly(ethylene oxide), PEO, is a relatively nonpolar polymer but contains ether oxygens

Hong, Mei

346

Synthesis and Characterization of Poly(Ethylene Glycol)-Based Single-Ion Conductors  

E-print Network

of the polymer matrix. 1. Introduction Poly(ethylene oxide) (PEO) has been extensively inves- tigatedSynthesis and Characterization of Poly(Ethylene Glycol)-Based Single-Ion Conductors Shichen DouVania 16802 ReceiVed February 14, 2006 A series of ionomers was synthesized by melt polycondensation of poly(ethylene

Colby, Ralph H.

347

Static strength of modified polyethylene films after prolonged exposure in different climatic zones  

Microsoft Academic Search

Conclusions 1.In the original condition, alloying of film polyethylene with thermoelastoplastic and also with additions of carbon black leads to a reduction in ultimate strength and an increase in deformability.2.Alloying with thermoelastoplastic has practically no effect on film polyethylene aging rate.3.Alloying with thermoelastoplastic together with additions of carbon black reduces the aging rate for film polyethylene.

É. S. Umanskii; N. S. Shidlovskii; L. L. Stezhko; R. M. Kas'yan; V. S. Sychov; B. N. Rybakov

1985-01-01

348

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

Federal Register 2010, 2011, 2012, 2013, 2014

...order on polyethylene retail carrier bags from Thailand...from the Polyethylene Retail Carrier Bag Committee...by Thai Plastic Bags Industries Co., Ltd., the Department...order on polyethylene retail carrier bags from Thailand...liquidation of the relevant entries during this review...

2010-06-18

349

The crystallographic texture of a great number of polyethylene films manufactured by the film  

E-print Network

The crystallographic texture of a great number of polyethylene films manufactured by the film polymer films (fig. 1). It is essentially dedicated to polyethylene, espe- cially for packaging in polyethylene blown films J.-M. Haudin, J.-M. André, G. Bellet, B. Monasse, P. Navard École des Mines de Paris

Paris-Sud XI, Université de

350

MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE  

E-print Network

MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE Gagan Deep distribution of temperature during drop-wise condensation over a polyethylene substrate was measured using on the substrate was simultaneously visualized. Static contact angles of water on polyethylene are measured

Khandekar, Sameer

351

Macromolecules 1991,24, 5687-5694 5687 Characterization of Molecular Orientation in Polyethylene by  

E-print Network

Macromolecules 1991,24, 5687-5694 5687 Characterization of Molecular Orientation in Polyethylene bonds in thick processed samples of polyethylene. Introduction In order to take full advantage to the production of high-modulusfibersandfilms. High-density polyethylene isoneof the polymers that has been used

Pezolet, Michel

352

Substrate Effect on the Melting Temperature of Thin Polyethylene Films M. Rafailovich,1,* J. Sokolov,1  

E-print Network

Substrate Effect on the Melting Temperature of Thin Polyethylene Films Y. Wang,1 M. Rafailovich,1 polyethylene thin films. The Tm decreases with the film thickness decrease when the film is thinner than that the degree of crystal- linity of polyethylene (PE) remained high even in films as thin as 15 nm [5]. A novel

353

Rheology of Low-Density Polyethylene Boehmite Piotr Blaszczak,1,2  

E-print Network

Rheology of Low-Density Polyethylene þ Boehmite Composites Piotr Blaszczak,1,2 Witold Brostow,1), University of North Texas, Denton 76203-5017, Texas Polyethylene is already one of the most commonly used polymers due to its solvent resistance and easy processing. Low-density polyethylene (LDPE) also has

North Texas, University of

354

Soil bacterial strains able to grow on the surface of oxidized polyethylene film containing prooxidant additives  

E-print Network

Soil bacterial strains able to grow on the surface of oxidized polyethylene film containing low-density polyethylene film containing prooxidant additives were isolated from three forest soils of adhering to the surface of oxidized polyethylene, growing there and possibly biodegrading its oxidation

Boyer, Edmond

355

Creep Behavior of High Density Polyethylene after Aging in Contact with Different Oil Derivates  

E-print Network

Creep Behavior of High Density Polyethylene after Aging in Contact with Different Oil Derivates The creep behavior of a high density polyethylene (HDPE), currently used as raw material for pipe manu polyethylene (HDPE) is a natural choice due to its good properties, its large availability, and its reduced

Paris-Sud XI, Université de

356

Rice Straw Fiber Reinforced High Density Polyethylene Composite: Effect of Coupled Compatibilizating and  

E-print Network

Rice Straw Fiber Reinforced High Density Polyethylene Composite: Effect of Coupled polyethylene (HDPE) composites were manufactured by extrusion and injection molding. Three compatibilizers compatibilizers, ma- leic anhydride grafted polyethylene and polypropylene (PE-g-MA and PP-g-MA) are considered

357

Reduced adhesion of human blood platelets to polyethylene tubing by microplasma surface modification  

E-print Network

Reduced adhesion of human blood platelets to polyethylene tubing by microplasma surface of small-diameter polyethylene (PE) tubing. A microwave cavity diagnostic was used to measure the density tubing and the emitted light intensity was found. A poly(ethylene oxide) surfactant was immobilized

von Andrian, Ulrich H.

358

Thermal rectification at silicon-amorphous polyethylene interface Ming Hu,1,a  

E-print Network

Thermal rectification at silicon-amorphous polyethylene interface Ming Hu,1,a Pawel Keblinski,1,b heat currents. We estimate that in the limit of large heat currents, the silicon-amorphous polyethylene by amorphous polymer polyethylene PE and silicon crystal. We will also show that the mecha- nism governing

Li, Baowen

359

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

E-print Network

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 and processing conditions. Equistar, in Cincinnati, is the largest producer of polyethylene in the US and P

Beaucage, Gregory

360

A MODIFIED GAMBLER'S RUIN MODEL POLYETHYLENE CHAINS IN THE AMORPHOUS REGION  

E-print Network

A MODIFIED GAMBLER'S RUIN MODEL OF POLYETHYLENE CHAINS IN THE AMORPHOUS REGION Zhong­Hui Duan and Louis N. Howard Department of Mathematics The Florida State University ABSTRACT. Polyethylene chainsM 3 +O(M 2 ). INTRODUCTION Semicrystalline polyethylene formed from melt generally consists

Aluffi, Paolo

361

Creep Failure and Fracture of Polyethylene in Uniaxial J. M. CRISSMAN and L. J. ZAPAS  

E-print Network

Creep Failure and Fracture of Polyethylene in Uniaxial Extension J. M. CRISSMAN and L. J. ZAPAS conditions of uniaxial creep the frac- ture of high density polyethylene can be categorized as one of three, this phenomenon is known as dead load fatigue. In the case of polyethylene the ultimate fracture can

362

Thermal resistance and phonon scattering at the interface between carbon nanotube and amorphous polyethylene  

E-print Network

polyethylene Sho Hida a , Takuma Hori a , Takuma Shiga a , James Elliott b , Junichiro Shiomi a,c, a Department dynamics study of heat conduction in carbon nanotube (CNT)/polyethylene (PE) composites. Particular across the CNT/polyethylene interfaces ($1 Â 10À7 m2 K WÀ1 ) and a moder- ate but non

Elliott, James

363

Density functional study of molecular crystals: Polyethylene and a crystalline analog of bisphenol-A polycarbonate  

E-print Network

Density functional study of molecular crystals: Polyethylene and a crystalline analog of bisphenol polyethylene comprising covalently bonded parallel chains with weak interchain interactions, and b reaction barriers.8 In a recent study of the interchain interactions in crystalline polyethylene PE ,9 we

364

Number Plastic Type Common Items Number of Items (tally) 1 polyethylene terephthalate  

E-print Network

End Time: Number Plastic Type Common Items Number of Items (tally) 1 polyethylene terephthalate and vegetable oil containers; ovenable food trays. 2 high density polyethylene Milk jugs, juice bottles; bleach, piping, candy wrappers 4 low density polyethylene Squeezable bottles; bread, frozen food, dry cleaning

Schladow, S. Geoffrey

365

DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures  

E-print Network

DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures polyethylenes of types HDPE, LDPE, and LLDPE. DSC data were obtained for a range of heating and cooling rates previous rheology findings of order and high-temperature transitions in polyethylene melts. Introduction

Hussein, Ibnelwaleed A.

366

Effect of the sliding orientation on the tribological properties of polyethylene in molecular dynamics simulations  

E-print Network

Effect of the sliding orientation on the tribological properties of polyethylene in molecular properties of polyethylene PE is investigated by using classical molecular dynamics simulations. Cross: 10.1063/1.2900884 I. INTRODUCTION Polyethylene PE is one of the most widely used poly- mers because

Sawyer, Wallace

367

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

E-print Network

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 adhesion bonds to the polyethylene matrix. © 2005 American Institute of Physics. DOI: 10.1063/1.1868060 I

Garmestani, Hamid

368

Simulation of the effects of chain architecture on the sorption of ethylene in polyethylene  

E-print Network

Simulation of the effects of chain architecture on the sorption of ethylene in polyethylene Brian J in amorphous linear low-density polyethylene of different chain architectures. The NERD united-atom force field investigated the effect of polyethylene chain length and branching on ethylene solubility. In this study, we

Faller, Roland

369

Crystallographic texture evolution in high-density polyethylene during uniaxial tension  

E-print Network

Crystallographic texture evolution in high-density polyethylene during uniaxial tension D. Lia , H experimental measurements of crystallographic texture evolution in high-density polyethylene subjected to very straining of high-density polyethylene to large strains. There are at least three distinct preferred

Garmestani, Hamid

370

76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2011-0583; FRL-8891-4] Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol...a tolerance for residues of methacrylic acid-methyl methacrylate- polyethylene glycol...permissible level for residues of methacrylic acid-methyl methacrylate-polyethylene...

2011-11-09

371

Primary Radiation Defect Production in Polyethylene and Cellulose Jussi Polvi,* Petri Luukkonen, and Kai Nordlund  

E-print Network

Primary Radiation Defect Production in Polyethylene and Cellulose Jussi Polvi,* Petri Luukkonen in polyethylene and cellulose were examined using molecular dynamics simulations. The governing reactions in both. Crystalline cellulose was found to be more resistant to radiation damage than crystalline polyethylene

Nordlund, Kai

372

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 Agricultural Center, Baton Rouge, LA 70803, United States a r t i c l e i n f o Article history: Received 2 January 2010 Keywords: Wood plastic composites Poly(ethylene terephthalate) Polyethylene Extrusion a b

373

DELIVERY OF THERAPEUTIC PROTEINS  

PubMed Central

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

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

2009-01-01

374

Structure and morphology of biaxially oriented films of polyethylenes  

Microsoft Academic Search

Biaxially oriented films of commercial polyethylenes were investigated using X-ray diffraction in directions transverse and perpendicular to the film plane. The surface morphology of the inner and outer faces of these films were studied in two directions by (a) transmission election microscopy employing replication procedures, (b) by atomic force microscopy (tapping mode) down to nanometer resolution, (c) scanning electron microscopy

M. Kojima; J. H. Magill; J. S. Lin; S. N. Magonov

1997-01-01

375

8 Ultrahigh molecular weight polyethylene from slurry Insite TM technology  

Microsoft Academic Search

Ultra-high molecular weight polyethylene (UHMWPE) homopolymer was prepared with the slurry INSITE™ technology and a Tebbe reagent. The molecular weight of the homopolymer was controlled from 2 million to 10 million of Mv by the concentration of the Tebbe reagent in the polymerization process. UHMWPE copolymer of ethylene and 1-hexene was also prepared. The molecular weight of the copolymer was

Koichi Hasebe; Akio Fujiwara; Takashi Nozaki; Koichi Miyamoto; Harumi Watanabe

2006-01-01

376

Preventing oxidation of iron sulfide minerals by polyethylene polyamines  

E-print Network

an important catalyzing role in the oxidation of sulfides and acid mine generation. Polyethylene polyamines. Keywords: Sulfide ores; Acid rock drainage; Oxidation; Surface modification; Redox reaction 1. Introduction The oxidation of sulfide minerals not only generates serious environmental damages by producing acid mine

Belzile, Nelson

377

A process for solidifying sodium nitrate waste in polyethylene  

SciTech Connect

A laboratory-scale process has been developed for the solidification of nitrate salt wastes in polyethylene. The process uses a commercially available single-screw extruder which continuously discharges prescribed polyethylene-waste mixtures from the hoppers to the output die, where it is extruded into a container while still in the molten form. The molten mixture (/approximately/110--120/degree/C) conforms to the shape of the container and solidifies upon cooling. Proportional feeders maintain waste to binder ratio and homogeneity of the waste form. Present studies use dry wastes, although wet solid wastes can be processed using vented extrudes of the type used for the bitumen solidification process. Tests were performed to determine leachability and mechanical stability. Emphasis is placed upon leaching of nitrates from the waste forms. Differential Scanning Calorimetry (DSC) was used to confirm the compatibility of polyethylene and simulated salt wastes at elevated temperatures. Components of the polyethylene/NaNO/sub 3/ system, alone and in combination, were tested by DSC at temperatures to 400/degree/C. 14 refs., 6 figs.

Heiser, J.H. III; Franz, E.M.; Colombo, P.

1987-04-01

378

Postconsumer polyethylene terephthalate (PET)\\/polyolefin blends through reactive processing  

Microsoft Academic Search

Increasing awareness of environmental and energy problems has promoted greater governmental interest in selected waste collection and consequently has attracted the interest of several research groups to the challenge of converting recovered plastics into useful materials. The reactive blending of postconsumer polyethylene terephthalate (PET) with different polyolefins (PO) was studied in attempts to obtain a new material with enhanced properties

Mauro Aglietto; Maria-Beatrice Coltelli; Stefania Savi; Francesco Lochiatto; Francesco Ciardelli; Maurizio Giani

2004-01-01

379

Dimethyl sulfoxide enhances polyethylene glycol-mediated somatic cell fusion  

Microsoft Academic Search

The efficiency of fusion of human diploid cells by polyethylene glycol was greatly enhanced by addition of dimethyl sulfoxide. The extent of fusion was directly proportional to the concentrations of both of these compounds. At all except the highest concentrations, cell loss was moderate to minimal and perturbation of cell cycle function as measured by [3H]thymidine labeling indices and mitotic

T. H. Norwood; C. J. Zeigler; G. M. Martin

1976-01-01

380

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...

381

Control of Osmotic Pressure of Culture Solutions with Polyethylene Glycol  

Microsoft Academic Search

Experiments with kidney beans indicate that Carbowax polyethylene glycol, molecular weight 20,000, upon purification, may be used as an agent to control the osmotic pressure of plant nutrient solutions without the hazard of interference with normal metabolic processes. With the sodium electrode and the thermocouple psychrometer, interaction between ions and Carbowax is shown to lead to a slight dissociation of

J. V. Lagerwerff; Gen Ogata; Harold E. Eagle

1961-01-01

382

DUCTILE-TO-BRITTLE TRANSITION TIME IN POLYETHYLENE GEOMEMBRANE SHEET  

EPA Science Inventory

The susceptibility of polyethylene (PE) geomembranes to stress cracking was evaluated in the laboratory using an accelerated notched constant load testing (NCLT) method. he test specimens were subjected to various stress levels which ranged from 25% to 70% of the yield stress at ...

383

Modelling of thermal oxidation of phosphite stabilized polyethylene  

Microsoft Academic Search

The thermal oxidation behaviour of polyethylene films stabilized by various weight ratios of organophosphites (Irgafos 168) has been studied at selected temperatures. The duration of the induction period was found to increase proportionally with the stabilizer concentration, even at temperatures as low as 80 °C. Particular attention was paid to the phosphite–phosphate conversion during the induction period. A kinetic model, involving

Fatma Djouani; Emmanuel Richaud; Bruno Fayolle; Jacques Verdu

2011-01-01

384

Mechanical modifications in dense polyethylene induced by energetic electron beams  

Microsoft Academic Search

Effects of radiation damage in ultra high molecular weight polyethylene are investigated by using energetic electron beams. Special attention is devoted to the mechanical characterization of the polymer, before and after the modification induced by 5 MeV electrons, as a function of the absorbed dose. Elastic modules, ultimate tensile and compressive strengths and roughness and hardness, have been measured in

L. Torrisi; N. Campo; L. Auditore; R. Barna; D. de Pasquale; A. Italiano; A. Trifirbo; M. Trimarchi; G. di Marco

2004-01-01

385

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

E-print Network

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

Averbuch, Amir

386

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 ...

387

Occupational asthma due to polyethylene shrink wrapping (paper wrapper's asthma).  

PubMed

Occupational asthma due to the pyrolysis products of polyvinyl chloride (PVC) produced by shrink wrapping processes has previously been reported. The first case of occupational asthma in a shrink wrap worker using a different plastic, polyethylene, is reported; the association was confirmed by specific bronchial provocation testing. PMID:1440477

Gannon, P F; Burge, P S; Benfield, G F

1992-09-01

388

Occupational asthma due to polyethylene shrink wrapping (paper wrapper's asthma)  

Microsoft Academic Search

Occupational asthma due to the pyrolysis products of polyvinyl chloride (PVC) produced by shrink wrapping processes has previously been reported. The first case of occupational asthma in a shrink wrap worker using a different plastic, polyethylene, is reported; the association was confirmed by specific bronchial provocation testing.

P F Gannon; P S Burge; G F Benfield

1992-01-01

389

Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for  

E-print Network

Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for Adhesion Improvement Uwe] The pretreatment modifies the surface properties of the substrate, thereby improving the adhesion strength parts of a substrate selectively.[3,4] Also, in contrast to most corona treatments (and dielectric

Greifswald, Ernst-Moritz-Arndt-Universität

390

Dynamic tensile testing of aramid and polyethylene fiber composites  

Microsoft Academic Search

Dynamic properties of materials such as aramid and polyethylene fiber reinforced composites are rarely found in the literature, in spite of their significance in ballistic design. It is also difficult to find detailed descriptions of the testing techniques and procedures to characterize these materials. This paper describes a dynamic tensile testing technique for these composite materials, and discusses problems such

I. S. Chocron Benloulo; J. Rodríguez; M. A. Martínez; V. Sánchez Gálvez

1997-01-01

391

Coprocessing of heavy shale oil with polyethylene waste  

Microsoft Academic Search

Copyrolysis of heavy shale oil with polyethylene (PE) waste in autoclaves at various temperatures and times has been studied. It is shown that the copyrolysis improves the quality of the oil obtained and gives possibility to transform the wastes into liquid fuels. The copyrolysis of heavy oil and PE in the ratio 1:1 increases the percentage of aliphatic hydrocarbons in

Laine Tiikma; Hindrek Tamvelius; Lea Luik

2007-01-01

392

DC Treeing Breakdown Associated with Space Charge Formation in Polyethylene  

Microsoft Academic Search

It is well known that space charge accumulation has a great influence on both the short-time and long-time breakdown strengths of plastic insulation systems operating under direct voltages. In this paper, dc treeing phenomena initiated from the tip of a needle electrode inserted into a polyethylene specimen have been investigated under various conions. The characteristics of four kinds of trees,

Ieda; Nawata

1977-01-01

393

Morphology Effects on Space Charge Characteristics of Low Density Polyethylene  

Microsoft Academic Search

Low density polyethylene (LDPE) film samples with different morphology were prepared by three kinds of annealing methods which were different in cooling rates in this study. A pulsed electro-acoustic (PEA) space charge measurement system was improved to solve the surface discharge problems for small samples applied with a high voltage. Negative direct current (DC) fields from 50 to above 220

Zhou Yuanxiang; Wang Yunshan; Markus Zahn; Wang Ninghua; Sun Qinghua; Liang Xidong; Guan Zhichen

2011-01-01

394

Space charge behavior in polyethylene under AC electric fields  

Microsoft Academic Search

Polyethylene has been widely used as the insulation of high voltage power cables due to its excellent dielectric properties and electrical performance. The existence of space charge in polymeric insulators is a significant issue with respect to life expectation. It can alter the local electric field and initiate possible partial discharge or eventual breakdown. This appears relatively more severe under

J. Zhao; Z. Xu; G. Chen; P. L. Lewin

2011-01-01

395

Charge trapping in corona-charge polyethylene films  

Microsoft Academic Search

A model for the process of surface potential decay of insulating films following charging by corona ions is developed. Account is taken of charge trapping and release at sites both in the surface and in the bulk where trapping can reduce the mobility significantly. The model is particularly applicable to polyethylene films and is used to interpret measurements of surface

R. Toomer; T. J. Lewis

1980-01-01

396

Wood-Fiber/High-Density-Polyethylene Composites: Coupling Agent Performance  

E-print Network

.interscience.wiley.com). ABSTRACT: The coupling efficiency of seven coupling agents in wood­polymer composites (WPC) was investi structure. As a coupling agent, mal- eated polyethylene (MAPE) had a better performance in WPC than oxidized on the interfacial bonding in WPC. The coupling agents with a high molecular weight, moderate acid number, and low

397

Oscillatory carbonylation using alkyne-functionalised poly(ethylene glycol).  

PubMed

In this study palladium-catalysed oscillatory carbonylation has been achieved using mono alkyne-terminated poly(ethylene glycol) methyl ether substrates. Reproducible, synchronised oscillations in pH and solution turbidity have been recorded over several days. A reaction network accounting for the observed phenomena has been proposed. PMID:24957532

Donlon, Lynn; Novakovic, Katarina

2014-12-21

398

Thermal conductivity of boron nitride reinforced polyethylene composites  

Microsoft Academic Search

The thermal conductivity of boron nitride (BN) particulates reinforced high density polyethylene (HDPE) composites was investigated under a special dispersion state of BN particles in HDPE, i.e., BN particles surrounding HDPE particles. The effects of BN content, particle size of HDPE and temperature on the thermal conductivity of the composites were discussed. The results indicate that the special dispersion of

Wenying Zhou; Shuhua Qi; Qunli An; Hongzhen Zhao; Nailiang Liu

2007-01-01

399

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...

400

Polyethylene\\/Boron Composites for Radiation Shielding Applications  

Microsoft Academic Search

Multifunctional composites made with boron are absorbers of low energy nuetrons, and could be used for structural shielding materials. Polyethylene\\/boron carbide composites were fabricated using conventional polymer processing techniques, and were evaluated for mechanical and radiation shielding properties. Addition of neat boron carbide (powder and nanoparticles) to an injection molding grade HPDE showed superior mechanical properties compared to neat HDPE.

Courtney Harrison; Eric Burgett; Nolan Hertel; Eric Grulke

2008-01-01

401

Polyethylene Terephthalate Waste Recycling and Application Possibilities: a Review  

Microsoft Academic Search

This paper presents a review of works that cover PET post-consumer waste recycling and application during last twenty years. It is shown that physically recycled PET can be used in the blends with other polymers, such as high and low density polyethylene, polycarbonates, polyvinyl chloride, etc. The compatibilizers and other additives often are used to obtain valuable blends of recycled

Gintaras MACIJAUSKAS

402

Controlling Affinity Binding with Peptide-Functionalized Poly(ethylene glycol) Hydrogels**  

PubMed Central

Poly(ethylene glycol) (PEG) hydrogels functionalized with peptide moieties have been widely used in regenerative medicine applications. While many studies have suggested the importance of affinity binding within PEG hydrogels, the relationships between the structures of the peptide motifs and their binding to protein therapeutics remain largely unexplored, especially in the recently developed thiol-acrylate photopolymerization systems. Herein, we employ Förster resonance energy transfer (FRET) and thiol-acrylate photopolymerizations to investigate how the architectures of affinity peptides in crosslinked hydrogels affect their binding to diffusible proteins. The binding between diffusible streptavidin and biotinylated peptide immobilized to PEG hydrogel network was used as a model system to reveal the interplay between affinity binding and peptide sequences/architectures. In addition, we design peptides with different structures to enhance affinity binding within PEG hydrogels and to provide tunable affinity-based controlled delivery of basic fibroblast growth factor (bFGF). This study demonstrates the importance of affinity binding in controlling the availability of hydrogel-encapsulated proteins and provides strategies for enhancing affinity binding of protein therapeutics to bound peptide moieties in thiol-acrylate photopolymerized PEG hydrogels. The results presented herein should find useful on the design and fabrication of hydrogels to retain and sustained release of growth factors for promoting tissue regeneration. PMID:20148198

Lin, Chien-Chi; Anseth, Kristi S.

2009-01-01

403

Infrared, Raman and INS studies of poly-ethylene oxide oligomers  

NASA Astrophysics Data System (ADS)

In the present paper the experimental findings obtained by different spectroscopic techniques on water mixtures of a protein model system, i.e. PolyEthylene Oxide (PEO), are reported. By increasing the polymerization degree m, the D-LAM spectral contribution shows a behavior of the centre frequency and of linewidth which tends to reach a constant value. Also the intramolecular OH stretching contribution, by increasing m, shows a shift which tends to flatten for polymers with molecular weight higher than Mw = 600. These results can be connected with the oligomer-polymer transition, at m = 13. When in aqueous solutions the D-LAM frequency increases towards the value corresponding to that of the crystal phase; similarly one observes also a sharpening of the D-LAM spectral contribution. These evidences suggest the presence of a more ordered conformation of PEO in water in respect to the melt phase.

Migliardo, F.; Magazù, S.; Caccamo, M. T.

2013-09-01

404

Polyethylene glycol (PEG)-mediated transient gene expression in a red alga, Cyanidioschyzon merolae 10D.  

PubMed

DNA introduction into cells is an essential technique for molecular genetic analysis. Here, we show that DNA is easily introduced into cells of the unicellular red alga Cyanidioschyzon merolae by a polyethylene glycol (PEG)-mediated protocol. In this study, the beta-tubulin gene of C. merolae was cloned on a plasmid and a hemagglutinin (HA) tag then added at the C-terminus. This plasmid was then introduced into C. merolae cells by a PEG-mediated transformation protocol. At 24 h after PEG-mediated transformation, intracellular localization of the tagged protein was detected by anti-HA immunocytochemistry, indicating the utility of this transient expression system for molecular genetic analyses. PMID:18003671

Ohnuma, Mio; Yokoyama, Takashi; Inouye, Takayuki; Sekine, Yasuhiko; Tanaka, Kan

2008-01-01

405

Poly(ethylene glycol)-Prodrug Conjugates: Concept, Design, and Applications  

PubMed Central

Poly(ethylene glycol) (PEG) is the most widely used polymer in delivering anticancer drugs clinically. PEGylation (i.e., the covalent attachment of PEG) of peptides proteins, drugs, and bioactives is known to enhance the aqueous solubility of hydrophobic drugs, prolong circulation time, minimize nonspecific uptake, and achieve specific tumor targetability through the enhanced permeability and retention effect. Numerous PEG-based therapeutics have been developed, and several have received market approval. A vast amount of clinical experience has been gained which has helped to design PEG prodrug conjugates with improved therapeutic efficacy and reduced systemic toxicity. However, more efforts in designing PEG-based prodrug conjugates are anticipated. In light of this, the current paper highlights the synthetic advances in PEG prodrug conjugation methodologies with varied bioactive components of clinical relevance. In addition, this paper discusses FDA-approved PEGylated delivery systems, their intended clinical applications, and formulations under clinical trials. PMID:22645686

Banerjee, Shashwat S.; Aher, Naval; Patil, Rajesh; Khandare, Jayant

2012-01-01

406

Tuning the superstructure of ultrahigh-molecular-weight polyethylene/low-molecular-weight polyethylene blend for artificial joint application.  

PubMed

An easy approach was reported to achieve high mechanical properties of ultrahigh-molecular-weight polyethylene (UHMWPE)-based polyethylene (PE) blend for artificial joint application without the sacrifice of the original excellent wear and fatigue behavior of UHMWPE. The PE blend with desirable fluidity was obtained by melt mixing UHMWPE and low molecular weight polyethylene (LMWPE), and then was processed by a modified injection molding technology-oscillatory shear injection molding (OSIM). Morphological observation of the OSIM PE blend showed LMWPE contained well-defined interlocking shish-kebab self-reinforced superstructure. Addition of a small amount of long chain polyethylene (2 wt %) to LMWPE greatly induced formation of rich shish-kebabs. The ultimate tensile strength considerably increased from 27.6 MPa for conventional compression molded UHMWPE up to 78.4 MPa for OSIM PE blend along the flow direction and up to 33.5 MPa in its transverse direction. The impact strength of OSIM PE blend was increased by 46% and 7% for OSIM PE blend in the direction parallel and vertical to the shear flow, respectively. Wear and fatigue resistance were comparable to conventional compression molded UHMWPE. The superb performance of the OSIM PE blend was originated from formation of rich interlocking shish-kebab superstructure while maintaining unique properties of UHMWPE. The present results suggested the OSIM PE blend has high potential for artificial joint application. PMID:22339721

Xu, Ling; Chen, Chen; Zhong, Gan-Ji; Lei, Jun; Xu, Jia-Zhuang; Hsiao, Benjamin S; Li, Zhong-Ming

2012-03-01

407

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

PubMed

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

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

2015-04-01

408

Long-term culture of HL1 cardiomyocytes in modular poly(ethylene glycol) microsphere-based scaffolds crosslinked in the phase-separated state  

Microsoft Academic Search

Poly(ethylene glycol) (PEG) microspheres were assembled around HL-1 cardiomyocytes to produce highly porous modular scaffolds. In this study we took advantage of the immiscibility of PEG and dextran to improve upon our previously described modular scaffold fabrication methods. Phase separating the PEG microspheres in dextran solutions caused them to rapidly deswell and crosslink together, eliminating the need for serum protein-based

Amanda W. Smith; Claire E. Segar; Peter K. Nguyen; Matthew R. MacEwan; Igor R. Efimov; Donald L. Elbert

409

Gamma Inert Sterilization: A Solution to Polyethylene Oxidation?  

PubMed Central

Background: In the 1990s, oxidation was found to occur in ultra-high molecular weight polyethylene total joint replacement components following gamma irradiation and prolonged shelf aging in air. Orthopaedic manufacturers developed barrier packaging to reduce oxidation during and after radiation sterilization. The present study explores the hypothesis that polyethylene components sterilized in a low-oxygen environment undergo similar in vivo oxidative mechanisms as inserts sterilized in air. In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined. Methods: An analysis of oxidation, wear, and surface damage was performed for forty-eight acetabular liners and 123 tibial inserts. The mean implantation time was 12.3 ± 3.7 years for thirty-one acetabular liners that had been gamma sterilized in air and 4.0 ± 2.5 years for the seventeen acetabular liners that had been gamma sterilized in inert gas. The mean implantation time was 11.0 ± 3.2 years for the twenty-six tibial inserts that had been sterilized in air and 2.8 ± 2.2 years for the ninety-seven tibial inserts that had been gamma sterilized in inert gas. Oxidation and hydroperoxide levels were characterized in loaded and unloaded regions of the inserts. Results: Measurable oxidation and oxidation potential were observed in all cohorts. The oxidation and hydroperoxide levels were regional. Surfaces with access to body fluids were more heavily oxidized than protected bearing surfaces were. This variation appeared to be greater in historical (gamma-in-air-sterilized) components. Regarding wear performance, historical and conventional acetabular liners showed similar wear penetration rates, whereas a low incidence of delamination was confirmed for the conventional tibial inserts in the first decade of implantation. Conclusions: The present study explores the impact of industry-wide changes in sterilization practices for polyethylene. We found lower oxidation and oxidation potential in the conventional acetabular liners and tibial inserts that had been gamma sterilized in inert gas as compared with the historical components that had been gamma sterilized in air. However, we also found strong evidence that conventional components undergo mechanisms of in vivo oxidation similar to those observed following gamma irradiation in air. In addition, gamma sterilization in inert gas did not provide polyethylene with a significant improvement in terms of wear resistance as compared with gamma sterilization in air, except for a lower incidence of delamination in the first decade of implantation for tibial inserts. Clinical Relevance: Our research demonstrates that gamma inert sterilization may have improved, but not completely solved, the problem of polyethylene oxidation for hip and knee arthroplasty. PMID:19339568

Medel, Francisco J.; Kurtz, Steven M.; Hozack, William J.; Parvizi, Javad; Purtill, James J.; Sharkey, Peter F.; MacDonald, Daniel; Kraay, Matthew J.; Goldberg, Victor; Rimnac, Clare M.

2009-01-01

410

Polyethylene encapsulation full-scale technology demonstration. Final report  

SciTech Connect

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.

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

1994-10-01

411

Hyperthermal atomic oxygen reactions with kapton and polyethylene  

SciTech Connect

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.

Cross, J.B. (Los Alamos National Lab., NM (USA)); Koontz, S.L. (National Aeronautics and Space Administration, Houston, TX (USA). Lyndon B. Johnson Space Center); Gregory, J.C.; Edgell, M.J. (Alabama Univ., Huntsville, AL (USA). Dept. of Chemistry)

1990-01-01

412

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

413

Polyethylene glycol rinse solution: An effective way to prevent ischemia-reperfusion injury  

PubMed Central

AIM: To test whether a new rinse solution containing polyethylene glycol 35 (PEG-35) could prevent ischemia-reperfusion injury (IRI) in liver grafts. METHODS: Sprague-Dawley rat livers were stored in University of Wisconsin preservation solution and then washed with different rinse solutions (Ringer’s lactate solution and a new rinse solution enriched with PEG-35 at either 1 or 5 g/L) before ex vivo perfusion with Krebs-Heinseleit buffer solution. We assessed the following: liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity), liver function (bile output and vascular resistance), oxidative stress (malondialdehyde), nitric oxide, liver autophagy (Beclin-1 and LCB3) and cytoskeleton integrity (filament and globular actin fraction); as well as levels of metalloproteinases (MMP2 and MMP9), adenosine monophosphate-activated protein kinase (AMPK), heat shock protein 70 (HSP70) and heme oxygenase 1 (HO-1). RESULTS: When we used the PEG-35 rinse solution, reduced hepatic injury and improved liver function were noted after reperfusion. The PEG-35 rinse solution prevented oxidative stress, mitochondrial damage, and liver autophagy. Further, it increased the expression of cytoprotective heat shock proteins such as HO-1 and HSP70, activated AMPK, and contributed to the restoration of cytoskeleton integrity after IRI. CONCLUSION: Using the rinse solution containing PEG-35 was effective for decreasing liver graft vulnerability to IRI. PMID:25473175

Zaouali, Mohamed Amine; Bejaoui, Mohamed; Calvo, Maria; Folch-Puy, Emma; Pantazi, Eirini; Pasut, Gianfranco; Rimola, Antoni; Ben Abdennebi, Hassen; Adam, René; Roselló-Catafau, Joan

2014-01-01

414

Charge distribution and crystalline structure in polyethylene nucleated with sorbital  

Microsoft Academic Search

The charge distribution in samples under dc electrical field is measured by pulsed electro-acoustic (PEA) method, and it was found that the space charges were greatly decreased and field distribution trended to uniform in low density polyethylene (LDPE) by adding 0.3 wt% of Bis-(p-ethylbenzylidene) sorbital. The crystalline structures of LDPE and LDPE\\/sorbital were studied. The non-isothermal crystallization kinetics was investigated

Li Xiang; Qiangguo Du; Yin Yi; Demin Tu

2000-01-01

415

Gas solubility, diffusivity and permeability in poly(ethylene oxide)  

Microsoft Academic Search

The effect of pressure on the solubility, diffusivity, and permeability of He, H2, O2, N2, CO2, CH4, C2H4, C2H6, C3H6 and C3H8 in poly(ethylene oxide) (PEO) is reported at 35°C. Additionally, the temperature dependence of permeability is reported. The effect of polar ether linkages in PEO on gas transport is illustrated by comparing transport properties in PEO with those in

H. Lin; B. D. Freeman

2004-01-01

416

Poly(ethylene oxide)\\/NH 4 +-smectite nanocomposites  

Microsoft Academic Search

New materials based on the intercalation of poly(ethylene oxide), PEO, into homoionic NH4+-smectites (montmorillonite and hectorite) have been synthesised and characterised. IR spectroscopy of the resultant nanocomposites shows changes in the polymer helical conformation of PEO as well as in the Td symmetry of the ammonium ion. Intercalation of PEO into NH4+-hectorite produces a material with regular stacking of the

Pilar Aranda; Eduardo Ruiz-Hitzky

1999-01-01

417

Gelcasting of ceramic suspension in acrylamide\\/polyethylene glycol systems  

Microsoft Academic Search

A new polyethylene glycol\\/acrylamide-based gelcasting system has been developed. The new system performs at least as well as, and in some cases better than, the original acrylamide-based system. The development of this system is for the sake of eliminating the surface-exfoliation phenomenon of green bodies gelcast in air. This study concentrates attention on dispersion, rheological and gelation behavior in the

Jingtao Ma; Zhipeng Xie; Hezhuo Miao; Yong Huang; Yingbing Cheng

2002-01-01

418

Cold crystallization of poly(ethylene glycol)–water systems  

Microsoft Academic Search

Phase transition behaviour of poly(ethylene glycol) (PEG)–water systems was investigated by differential scanning calorimetry (DSC) in a temperature range from 150 to 350K and water content (mass of water\\/mass of PEG) range from 0 to 10gg?1. In DSC heating curves, glass transition, cold crystallization, melting of eutectic crystal, water and PEG crystal were observed depending on water content. The cold

Tatsuko Hatakeyma; Hazuki Kasuga; Masaru Tanaka; Hyoe Hatakeyama

2007-01-01

419

Low-temperature thermal properties of nylon and polyethylene  

Microsoft Academic Search

The thermal conductivity and heat capacity of polyethylene and nylon samples have been measured in the temperature range 0.15–4°K. A good theoretical fit is obtained for the thermal conductivity above 1°K by using a Debye ?2 phonon frequency distribution with constant mean free path internal boundary scattering and amorphous structure scattering. Below 1°K the experimental results show a lower power

Terry A. Scott; Johannes de Bruin; Monte M. Giles; Colin Terry

1973-01-01

420

Wettability of grafted poly(ethylene terephthalate) fibers  

Microsoft Academic Search

Graft copolymerisation of perfluorooctyl-2 ethanol acrylic monomer\\/stearyl methacrylate monomer mixture onto poly(ethylene terephthalate) fibers using benzoyl peroxide as initiator was carried out in order to improve water repellency. By characterising the surface free energy, the degree of water repellency can be evaluated. In this article, the Wilhelmy plate method is used to determinate the surface fiber wettability by probe liquids

Ahmida El-Achari; Abdellah Ghenaim; Claude Cazé

2002-01-01

421

Deformation processes in poly(ethylene terephthalate) fibers  

Microsoft Academic Search

The structure\\/property relationships in a series of melt-spun poly(ethylene terephthalate) (PET) fibers processed under different conditions have been investigated. The structure of the fibers was characterized using a variety of techniques, including gel permeation chromatography (GPC), differential scanning calorimetry (DSC), optical birefringence, and wide-angle x-ray scattering (WAXS). The mechanical properties of the PET fibers were also investigated, and the fibers

W.-Y. Yeh; R. J. Young

1998-01-01

422

Inhibited oxidation of polyethylene: anatomy of induction period  

Microsoft Academic Search

Oxidation of high-density polyethylene containing the strong phenolic antioxidant 2,2?-methylene-bis(4-methyl-6-tertbutylphenol) has been studied. During the induction period the antioxidant is consumed according to first-order kinetics, the rate constant depending on the initial antioxidant concentration; during the induction period about three moles of O2 are consumed per mole of antioxidant. Formation of hydrogen peroxide in the induction period of oxidation has

Yu. A. Shlyapnikov; N. K. Tyuleneva

1997-01-01

423

Solid polymer electrolytes based on polyethylene oxide-silver thiocyanate  

Microsoft Academic Search

The polymer electrolyte films obtained by the addition of silver thiocyanate to polyethylene oxide have been investigated by complex impedance spectroscopy, X-ray diffraction, FTIR, optical microscopy and transference number measurement techniques. It has been observed that complexation takes place mainly in the amorphous region and conductivity of the order of 10?6 S cm?1 has been observed at room temperature. Transference

S. S. Sekhon; Gurjinder Singh; S. A. Agnihotry; S. Chandra

1995-01-01

424

Surface characterization of polyethylene terephthalate\\/silica nanocomposites  

Microsoft Academic Search

Poly(ethylene terephthalate) (PET) based nanocomposites containing hydrophilic (i.e. Aerosil 200 or Aerosil TT 600) or hydrophobic (i.e. Aerosil R 972) nano-silica were prepared by melt compounding. Influence of nano-silica type on surface properties of the resultant nanocomposites was investigated by the use of Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurement (CAM), scanning electron microscopy (SEM)

Mazeyar Parvinzadeh; Siamak Moradian; Abosaeed Rashidi; Mohamad-Esmail Yazdanshenas

2010-01-01

425

Alterations in pancreatic ductal morphology following polyethylene pancreatic stent therapy  

Microsoft Academic Search

Background: Polyethylene stents placed in the main pancreatic duct induce morphologic alterations that may resemble chronic pancreatitis.Methods: We reviewed the sequential pancreatograms of stented patients who had long-term follow-up after stent removal.Results: Forty patients (66%) had a normal baseline pancreatogram, whereas 21 (34%) showed changes of chronic pancreatitis. In 49 of 61 patients (80.3%), one or more had new morphologic

Milton T. Smith; Stuart Sherman; Steven O. Ikenberry; Robert H. Hawes; Glen A. Lehman

1996-01-01

426

Molecular dynamics simulation of chains mobility in polyethylene crystal  

E-print Network

The mobility of polymer chains in perfect polyethylene (PE) crystal was calculated as a function of temperature and chain length through Molecular dynamics (MD) in united atom approximation. The results demonstrate that the chain mobility drastically increases in the vicinity of the phase transition from the orthorhombic to quasi-hexagonal phase. In the quasi-hexagonal phase, the chain mobility is almost independent on temperature and inversely proportional to the chain length.

V. I. Sultanov; V. V. Atrazhev; D. V. Dmitriev; S. F. Burlatsky

2014-01-17

427

Polyethylene thin-film growth via cluster-surface collisions  

Microsoft Academic Search

Molecular dynamics simulations have been performed to investigate the growth of polyethylene thin films via cluster-surface collisions. The substrate is hydrogen-terminated diamond (111) and a beam of four molecular clusters of ethylene impact the substrate at a velocity of 18 km\\/s. The atoms are characterized by a realistic many-body empirical potential for hydrocarbon systems. The goal of this study is

Thomas A. Plaisted; John D. Zahrt; W. Leigh Young; Lifeng Qi; Susan B. Sinnott

1999-01-01

428

Nonisothermal Melting and Crystallization of Foamed Crosslinked Polyethylene  

Microsoft Academic Search

Foamed crosslinked specimens of low density polyethylene are produced by hot mould injection moulding. Dicumylperoxide, as crosslinking agent and azodicarbonamide as blowing agent, were used. The three components are blended and granulated in advance in an extruder-granulator at temperatures of 100-125°C. The contents of blowing and crosslinking agents in the composites studied are 5-15 and 0.08-0.6, respectively, in percents by

G. Kotzev; N. Touleshkov; D. Christova; E. Nedkov

2000-01-01

429

Morphology and Mechanical Properties of Foamed Polyethylene-Polypropylene Blends  

Microsoft Academic Search

Blends of high-density polyethylene and polypropylene are foamed by means of extrusion using azodicarbonamide as a chemical blowing agent to study the effect of blending on the morphological and mechanical properties. At 0.5 wt% of blowing agent, optimum foam density is found to be around 417 kg\\/m3 for each blend composition, but the average cell size ranges between 130 and

Elias Herrera Tejeda; Carlos Zepeda Sahagún; Rubén González-Núñez; Denis Rodrigue

2005-01-01

430

Space charge behavior in low-density polyethylene  

Microsoft Academic Search

The space charge distribution in low-density polyethylene (LDPE) was measured with the pulsed electroacoustic (PEA) method. We used three types of LDPE: LDPE-L and LDPE-H were prepared by the high pressure process, and m-LDPE was polymerized with a metallocene catalyst. Space charge in LDPE strongly depended upon the electrode material. Semiconductive electrodes enhanced carrier injection into LDPE and, as a

T. Mizutani; H. Semi; K. Kaneko

2000-01-01

431

Energy levels of charge traps in polyethylene terephthalate films  

Microsoft Academic Search

Photo-stimulated discharge (PSD) spectroscopy of polyethylene terephthalate (PETP) films charged through contacting electrodes was performed in order to investigate the mechanism(s) of charge storage and to determine trap depths. The samples were irradiated in vacuum with monochromatic light (photon energies of 3 - 6.2 eV) at constant temperature. The laser-intensity modulation method (LIMM) was used to determine the polarization and

F. Camacho Gonzalezt; A. Mellinger; R. Gerhard-Multhaupt

2004-01-01

432

Do Polyethylene Plastic Covers Affect Smoke Emissions from Debris Piles?  

NASA Astrophysics Data System (ADS)

Shrubs and small diameter trees exist in the understories of many western forests. They are important from an ecological perspective; however, this vegetation also presents a potential hazard as “ladder fuels” or as a heat source to damage the overstory during prescribed burns. Cutting and piling of this material to burn under safe conditions is a common silvicultural practice. To improve ignition success of the piled debris, polyethylene plastic is often used to cover a portion of the pile. While burning of piled forest debris is an acceptable practice in southern California from an air quality perspective, inclusion of plastic in the piles changes these debris piles to rubbish piles which should not be burned. With support from the four National Forests in southern California, we conducted a laboratory experiment to determine if the presence of polyethylene plastic in a pile of burning wood changed the smoke emissions. Debris piles in southern California include wood and foliage from common forest trees such as sugar and ponderosa pines, white fir, incense cedar, and California black oak and shrubs such as ceanothus and manzanita in addition to forest floor material and dirt. Manzanita wood was used to represent the debris pile in order to control the effects of fuel bed composition. The mass of polyethylene plastic incorporated into the pile was 0, 0.25 and 2.5% of the wood mass—a range representative of field conditions. Measured emissions included NOx, CO, CO2, SO2, polycyclic and light hydrocarbons, carbonyls, particulate matter (5 to 560 nm), elemental and organic carbon. The presence of polyethylene did not alter the emissions composition from this experiment.

Weise, D. R.; Jung, H.; Cocker, D.; Hosseini, E.; Li, Q.; Shrivastava, M.; McCorison, M.

2010-12-01

433

Polyethylene and metal wear particles: characteristics and biological effects  

Microsoft Academic Search

This paper first presents a brief overview about the mechanism of wear particle formation as well as wear particle characteristics\\u000a in metal-on-polyethylene and metal-on-metal artificial hip joints. The biological effects of such particles are then described,\\u000a focusing on the inflammatory response induced by each type of particles as well as on how metal wear products may be the source\\u000a of

Isabelle Catelas; Markus A. Wimmer; Sandra Utzschneider

2011-01-01

434

Formation of low density polyethylene\\/hollow glass microspheres composites  

Microsoft Academic Search

Hydrogen is used to absorb heavy particle radiation, which is the most damaging radiation in space for humans. Low density polyethylene\\/hollow glass microsphere composites have been suggested as a possible radiation shield because of the high concentration of hydrogen and the low gravimetric density of the microspheres. Composites pressed under 3.90MPa (566psi) and 120°C have the highest probability of success

M. M. Ashton-Patton; M. M. Hall; J. E. Shelby

2006-01-01

435

Reasons of Revision for First-Generation Highly Crosslinked Polyethylenes  

PubMed Central

Over a ten-year period, we prospectively evaluated the reasons for revision for contemporary and highly crosslinked polyethylene formulations in a multicenter retrieval program. 212 consecutive retrievals were classified as conventional gamma-inert sterilized liners (n=37), annealed (Crossfire™, n=72), or remelted (Longevity™, XLPE, Durasul; n=93). The most frequent reasons for revision were loosening (35%), instability (28%) and infection (21%) and were not related to polyethylene formulation (p = 0.17). Annealed and remelted liners had comparable linear penetration rates (0.03 and 0.04 mm/y, respectively, on average) and were significantly lower than conventional retrievals (0.11 mm/y; p ? 0.0005). This retrieval study including first-generation highly crosslinked liners demonstrated lower wear than conventional polyethylene. While loosening remained the most prevalent reason for revision, we could not demonstrate a relationship between wear and loosening. The long-term clinical performance of first-generation highly crosslinked remains promising, based on the mid-term outcomes of the components documented in this study. PMID:20541895

Kurtz, Steven M.; Medel, Francisco; MacDonald, Daniel; Parvizi, Javad; Kraay, Matthew; Rimnac, Clare

2010-01-01

436

Wear of a sequentially annealed polyethylene acetabular liner  

PubMed Central

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

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

2014-01-01

437

Polyethylene Wear Is Influenced by Manufacturing Technique in Modular TKA  

PubMed Central

Polyethylene insert backside surface wear is implicated in osteolysis and failure of total knee arthroplasty. Manufacturing and sterilization methods reduce articular-sided wear. We questioned whether manufacturing technique influences the severity of backside wear. We examined 39 explanted tibial bearings in a blinded fashion using visual, stereomicroscopic, and scanning electron microscopic techniques. We examined 26 direct compression molded components and 13 nondirect compression molded components and applied a new backside wear severity score. The score characterized the magnitude of the various modes of wear with severity ranging from 0 (no wear) to 27 (severe wear). Time in vivo, tibial baseplate material, and manufacturing technique were used as variables for comparison. Backside wear was related to polyethylene manufacturing process with direct compression molded implants having a wear score of 2.3 and nondirect compression molded a score of 5.7. Time in vivo influenced backside wear, although direct compression molded predicted decreased backside wear independent of time in vivo. The data suggest manufacturing technique influences backside wear in total knee arthroplasty polyethylene inserts. PMID:18791779

Ellison, Bradley S.; Berend, Keith R.

2008-01-01

438

Absorption current behaviour of polyethylene/silica nanocomposites  

NASA Astrophysics Data System (ADS)

Absorption current is an important characteristic of polymers with regard to their time-domain response to a direct current (DC) poling field. This is because the results of absorption current measurements can be used to gain understanding of the relationship between space charge accumulation and movement. In semicrystalline polyethylene, for example, charge accumulation is likely to be influenced by the presence of charge trapping sites, which are associated with interfaces between the crystalline and amorphous phases. With the addition of a nanofiller, the charge transport mechanism will become more complicated than in the unfilled polymer, as the inclusion of the nanofiller will introduce nanofiller/polymer interfaces. The presence of such interfaces will affect the current flow due to the introduction or modification of the distribution of trapping sites within the system. In this paper, we report on an investigation into the absorption current behaviour of polyethylene nanocomposites containing 0 wt%, 2 wt%, 5 wt% and 10 wt% of silica nanofiller, either untreated or treated using trimethoxy(propyl)silane coupling agent. Our results indicate that the absorption current behaviour of the polyethylene was affected by the presence of the nanosilica. While the current behaviour through the unfilled polymer decreases with time in a conventional manner, all nanocomposites reveal an initial decrease followed by a period in which the current increases with increasing time of DC field application.

Lau, K. Y.; Vaughan, A. S.; Chen, G.; Hosier, I. L.; Holt, A. F.

2013-11-01

439

Nanostructured Composites Based on Polyethylene–Polyamide Blends. II. Probing the Orientation in Polyethylene–Polyamide Nanocomposites and Their Precursors  

Microsoft Academic Search

The present article discloses the orientation in some microfibrillar?reinforced materials (MFC), as well as in their precursors as revealed by small?angle x?ray scattering (SAXS) of synchrotron radiation. Compatibilized and noncompatibilized polymer blends based on high?density polyethylene (PE) and polyamide 12 (PA12) or polyamides 6 (PA6) taken in various proportions were prepared by consecutive melt blending, extruding, and cold drawing. These

Zlatan Denchev; Maria J. Oliveira; João F. Mano; Júlio C. Viana; Sérgio S. Funari

2005-01-01

440

A thermosensitive hydrogel based on biodegradable amphiphilic poly(ethylene glycol) polycaprolactone poly(ethylene glycol) block copolymers  

Microsoft Academic Search

A series of low molecular weight poly(ethylene glycol)-polycaprolactone-poly(ethylene glycol) (PEG-PCL-PEG) biodegradable block copolymers were successfully synthesized using isophorone diisocyanate (IPDI) as the coupling agent, and were characterized using 1H NMR and Fourier transform infrared spectroscopy. The aqueous solutions of the PEG-PCL-PEG copolymers displayed a special thermosensitive gel-sol transition when the concentration was above the corresponding critical gel concentration. Gel-sol phase

Chang Yang Gong; Zhi Yong Qian; Cai Bing Liu; Mei Juan Huang; Ying Chun Gu; Yan Jun Wen; Bing Kan; Ke Wang; Mei Dai; Xing Yi Li; Ma Ling Gou; Ming Jing Tu; Yu Quan Wei

2007-01-01

441

Synthesis, patterning and applications of star-shaped poly(ethylene glycol) biofunctionalized surfaces.  

PubMed

Poly(ethylene) glycol (PEG) is an excellent material to modify surfaces to resist non-specific protein adsorption. Linear PEG has been extensively studied both theoretically and experimentally and it has been found that resistance of PEG-coated surfaces to protein adsorption depends mainly on the molecular weight of the polymer and the surface grafting density. End-functionalized star-shaped PEGs allow for interpolymer crosslinking to form a dense layer. An excellent example of such a system consists of a 6-arm PEG/PPG (4 : 1) star polymer functionalized with isocyanate using IPDI. The end functionalization may be further biofunctionalized to recognize specific biomolecules such as streptavidin, His-tagged proteins, amino-terminated oligonucleotides and cell receptors. This functionalization may be patterned into specific geometries using stamping techniques or randomly distributed by statistical reaction of the end group with the biofunctional molecule in solution. The surface preparation uses simple spin-, dip- or spray-coating and produces smooth layers with low background fluorescence. These properties, together with the advantageous chemical properties of PEG, render the surfaces ideal for immobilizing proteins on surfaces with detection limits down to the single molecule level. Proteins immobilized on such surfaces are able to maintain their folded, functional form and are able to completely refold if temporarily exposed to denaturing conditions. Immobilized enzyme molecules were able to perform their function with the same activity as the enzyme in solution. Future directions of using surfaces coated with such crosslinked star polymers in highly sensitive and robust biotechnology applications will be discussed. PMID:17533455

Heyes, Colin D; Groll, Jürgen; Möller, Martin; Nienhaus, G Ulrich

2007-06-01

442

Tolerogenic activity of polyethylene glycol-conjugated lysozyme distinct from that of the native counterpart.  

PubMed Central

Conjugation of proteins with polyethylene glycol (PEG) has been reported to make the proteins tolerogenic. Native proteins are also potentially tolerogenic when given without adjuvants. We compared immunotolerogenic activities between PEG-conjugated and native hen egg-white lysozyme (HEL). BALB/c mice were given consecutive weekly intraperitoneal administrations of PEG-conjugated HEL, unmodified HEL or phosphate-buffered saline (PBS), for 3 weeks, then challenged with HEL in Freund's complete adjuvant. The pretreatment with PEG-HEL tolerized both T-cell and humoral responses, while native HEL tolerized only the T-cell response. Immunoglobulin G1 (IgG1) antibody was already elevated in HEL-pretreated mice prior to challenge immunization, followed by suppressed IgG2a and IgG2b, but spared IgG1 production after the antigen challenge, whereas PEG-HEL-pretreated mice produced no antibody in all IgG subclasses prior and subsequent to the antigen-challenge. Production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) by lymphoid cells in response to HEL in vitro was markedly suppressed in both the antigen-pretreated groups, while suppression of IL-4 production was evident only in PEG-HEL-, not in HEL-pretreated animals. Involvement of suppressor cells in these tolerance states was found to be unlikely, and the immunological property of PEG-HEL differed from deaggregated HEL that was similar to the original HEL. These results suggest a unique immunotolerogenic activity of PEG-conjugated proteins to suppress both T-helper type-1 (Th1)- and Th2-type responses, the result being extensive inhibition of all IgG subclass responses, while tolerance induction by unconjugated soluble proteins tends to be targeted on Th1-, but spares Th2-type responses. PMID:9616369

Ito, H O; So, T; Hirata, M; Koga, T; Ueda, T; Imoto, T

1998-01-01

443

Mechanical, Rheological, and Bioactivity Properties of Ultra High-Molecular-Weight Polyethylene Bioactive Composites Containing Polyethylene Glycol and Hydroxyapatite  

PubMed Central

Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA) as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50?phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P) precipitates on the composite surface as proven from SEM and XRD analysis. PMID:22666129

Ahmad, Mazatusziha; Wahit, Mat Uzir; Abdul Kadir, Mohammed Rafiq; Mohd Dahlan, Khairul Zaman

2012-01-01

444

Factory-assembled polyethylene linings in metal backing show higher wear rates compared to equisized all-polyethylene sockets.  

PubMed

Two series of cementless total hip arthroplasty with acetabular sockets of a threaded truncated cone design were compared regarding volumetric wear rates. The first series included all-polyethylene acetabular sockets of the type Endler (E-PE); in the second series, a nonmodular titanium metal-backed polyethylene (E-MB) socket with an identical outer shape to E-PE was implanted. Bearings were articulated with alumina 32-mm diameter ball heads. Ninety-five retrieved devices were examined with a modified fluid displacement method using dental self-polymerizing precision casts. The sockets had to be revised mainly because of wear-induced osteolysis: E-PE after 10.6 years on average and E-MB after 7.8 years (P = .002). Comparison with unused sockets showed mean wear rates of 63 mm(3)/y for E-PE and 120 mm(3)/y for E-MB (P = .0008). Increased contact stress and load deformation due to reduction of polyethylene thickness in E-MB compared to E-PE were identified as predominant reasons for higher wear rates. PMID:20647160

Jentschke, Matthias W; Schultz, Wolfgang; Buchhorn, Gottfried H

2011-06-01

445

Adhesion, Growth, and Maturation of Vascular Smooth Muscle Cells on Low-Density Polyethylene Grafted with Bioactive Substances  

PubMed Central

The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE) was treated by an Ar+ plasma discharge and then grafted with biologically active substances, namely, glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C), or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs), the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted. PMID:23586032

Parizek, Martin; Slepickova Kasalkova, Nikola; Bacakova, Lucie; Bacakova, Marketa; Lisa, Vera; Svorcik, Vaclav

2013-01-01

446

MALDI TOF-TOF characterization of a light stabilizer polymer contaminant from polypropylene or polyethylene plastic test tubes.  

PubMed

Disposable plasticware such as plastic test tubes are routinely used in all proteomics laboratories. Additives in polymers are used to protect them against oxygen or ultraviolet (UV) light degradation. Hindered amine light stabilizers (HALSs) are of utmost importance in modern polyolefin (polypropylene, polyethylene) stabilization. In this article, we demonstrate that the manufacturing polymeric agent: poly-(N-beta-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidinyl succinate), known as Tinuvin-622 or Lowilite 62, from the HALS family, leaches from laboratory polypropylene or polyethylene plastic test tubes into the standard solvents for sample preparation. The analysis of these polluted samples by matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry, in the positive mode, shows highly contaminated mass spectra, due to the high sensitivity of this technique. These contaminants have mass range and mass defect similar to those of peptides arising from the digestion of a protein in a conventional proteomics study. Therefore, they can be really harmful for proteomics studies, leading to misattributions, preventing any protein identification. In this article, an MS and MS/MS fingerprint of this pollutant is given and some pieces of advice to avoid it are proposed. PMID:19899063

Sachon, Emmanuelle; Matheron, Lucrèce; Clodic, Gilles; Blasco, Thierry; Bolbach, Gérard

2010-01-01

447

Protein adsorption characterization.  

PubMed

Protein adsorption from (aqueous) solutions onto a (solid) surface is a common process that takes place at biological interfaces. This phenomenon, that spontaneously occurs, changes the properties of the surface and can induce structural modifications on proteins. Proteins in solution can be easily identified/quantified using classical biochemical methods. However, adsorbed proteins are more difficult to assess since they are always associated with a substrate. The selection of the analytical method depends on the type of substrate used, the amount of adsorbed protein, the type of solution (single protein solution vs. complex biological media), and the type of information that is demanded (quantification of the adsorbed protein, adsorption kinetics, conformation, and orientation of the adsorbed protein). Until now, none of the techniques available are capable by its own to characterize all the protein adsorption process. Therefore, a multitechnique analysis is required. During this chapter, the methodologies to measure human serum albumin to poly(ethylene terephthalate) using the three different techniques, radiolabeling, ellipsometry, and quartz crystal microbalance with dissipation - QCM-D, are described in detail. The specific preparation of polymeric surfaces to be used with each technique is also presented. PMID:22042678

Martins, M Cristina L; Sousa, Susana R; Antunes, Joana C; Barbosa, Mário A

2012-01-01

448

Human polyethylene granuloma tissues inhibit bone healing in a novel xenograft animal model.  

PubMed

During revision of a conventional polyethylene joint replacement, surgeons usually remove the source of osteolysis (polyethylene) but cannot always remove all of the polyethylene granuloma tissues. We developed a human/rat xenograft model to investigate the effects of polyethylene granuloma tissues on bone healing. Human osteoarthritic and periprosthetic tissues collected during primary and revision hip arthroplasty surgeries were transplanted into the distal femora of athymic nude rats. After 3 weeks in vivo, there was a significant difference in the bone volume fraction (Vf ) between empty, primary, and revision defects (p?=?0.02), with a lower Vf in defects with revision granuloma tissues compared to defects with primary osteoarthritic tissues. Polyethylene granuloma tissues in trabecular bone defects inhibited bone healing. Therefore, debridement around a metal-on-polyethylene hip replacement may shorten the time it takes to achieve secondary stability around a revision hip replacement. PMID:24619566

Esposito, Christina I; Oliver, Rema A; Campbell, Patricia A; Yu, Yan; Walter, William L; Walter, William K; Walsh, William R

2014-06-01

449

Measurements of gas diffusion in polyethylene irradiated by 5MeV electron beams  

Microsoft Academic Search

The diffusion coefficient of light gas species in polyethylene is measured through a special apparatus which uses a vacuum chamber and a mass quadrupole spectrometer in order to detect the diffused species. Measurements are performed in thin polyethylene films with different molecular weight, which have been irradiated in air with 5 MeV electron beams. The irradiation modifies the polyethylene-inducing cross-linking

L. Torrisi; A. Ilacqua; F. Caridi; N. Campo; A. Picciotto; R. Barna; D. de Pasquale; M. Trimarchi; A. Trifiro; L. Auditore

2006-01-01

450

Experimental Flash Pyrolysis of High Density1 PolyEthylene under Hybrid Propulsion Conditions2  

E-print Network

1/25 Experimental Flash Pyrolysis of High Density1 PolyEthylene under Hybrid Propulsion Conditions2 Poly-Ethylene (HDPE) is studied6 up to 20 000 K.s-1 , under pressure up to 3.0 MPa and at temperature Pyrolysis (2013) 1-11" DOI : 10.1016/j.jaap.2013.02.014 #12;2/25 Keywords: Polyethylene; flash pyrolysis

Boyer, Edmond

451

Visualization of O-GlcNAc Glycosylation Stoichiometry and Dynamics using Resolvable Poly(ethylene glycol) Mass Tags  

PubMed Central

O -GlcNAc glycosylation is a dynamic protein posttranslational modification with roles in processes such as transcription, cell cycle regulation, and metabolism. Detailed mechanistic studies of O-GlcNAc have been hindered by a lack of methods for measuring O-GlcNAc stoichiometries and the interplay of glycosylation with other posttranslational modifications. We recently developed a method for labeling O-GlcNAc-modified proteins with resolvable poly(ethylene glycol) mass tags. This mass tagging approach enables the direct measurement of glycosylation stoichiometries and the visualization of distinct O-GlcNAc-modified subpopulations. Here, we describe protocols for labeling O-GlcNAc glycoproteins in cell lysates with mass tags. PMID:24391098

Clark, Peter M.; Rexach, Jessica E.; Hsieh-Wilson, Linda C.

2014-01-01

452

Manufacturing, structure and properties of recycled polyethylene terephthalate /liquid crystal polymer/montmorillonite clay nanocomposites  

NASA Astrophysics Data System (ADS)

Polyethylene terephthalate (PET)/liquid crystal polymer (LCP)/monthmorillonite clay (MMT) compositions were obtained by melt mixing. Their mechanical, structural, rheological and thermal properties were investigated.

Japins, Guntis; Berzina, Rita; Zicans, Janis; Merijs Meri, Remo; Ivanova, Tatjana; Kalkis, Valdis; Reinholds, Ingars

2013-12-01

453

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

E-print Network

and Conservation CRL 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...

McCaskill, Jennifer R.

2010-01-16

454

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

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

455

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

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

456

Ceramic Head Fracture in Ceramic-on-Polyethylene Total Hip Arthroplasty  

PubMed Central

Revision rates of total hip arthroplasty have decreased after introducing total hip arthroplasty (THA) using ceramic component, since ceramic components could reduce components wear and osteolysis. The fracture of a ceramic component is a rare but potentially serious event. Thus, ceramic on polyethylene articulation is gradually spotlighted to reduce ceramic component fracture. There are a few recent reports of ceramic head fracture with polyethylene liner. Herein, we describe a case of a ceramic head component fracture with polyethylene liner. The fractured ceramic head was 28 mm short neck with conventional polyethylene liner. We treated the patient by total revision arthroplasty using 4th generation ceramic on ceramic components. PMID:24142666

Nho, Jae-Hwi; Song, Ui-Seoub; Kim, Woo-Jong; Suh, You-Sung

2013-01-01

457

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

DOEpatents

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.

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

1986-01-01

458

Oxygen barrier performance of whey-protein-coated plastic films as affected by temperature, relative humidity, base film and protein type  

Microsoft Academic Search

Oxygen permeation properties of whey-protein-coated plastic films were examined to compare their oxygen-barrier performance as affected by temperature (15–40°C), relative humidity (30–85% RH), base film (PE: polyethylene & PP: polypropylene), and protein type (WPI: whey protein isolate & WPC: whey protein concentrate). The resulting whey-protein-coated films showed increase in oxygen permeability (OP) as temperature increased, with an Arrhenius behavior, and

Seok-In Hong; John M. Krochta

2006-01-01

459

An improved cryosection method for polyethylene glycol hydrogels used in tissue engineering.  

PubMed

The high water content of hydrogels allows these materials to closely mimic the native biological extracellular conditions, but it also makes difficult the histological preparation of hydrogel-based bioengineered tissue. Paraffin-embedding techniques require dehydration of hydrogels, resulting in substantial collapse and deformation, whereas cryosectioning is hampered by the formation of ice crystals within the hydrogel material. Here, we sought to develop a method to obtain good-quality cryosections for the microscopic evaluation of hydrogel-based tissue-engineered constructs, using polyethylene glycol (PEG) as a test hydrogel. Conventional sucrose solutions, which dehydrate cells while leaving extracellular water in place, produce a hydrogel block that is brittle and difficult to section. We therefore replaced sucrose with multiple protein-based and nonprotein-based solutions as cryoprotectants. Our analysis demonstrated that overnight incubation in bovine serum albumin (BSA), fetal bovine serum (FBS), polyvinyl alcohol (PVA), optimum cutting temperature (OCT) compound, and Fisher HistoPrep frozen tissue-embedding media work well to improve the cryosectioning of hydrogels. The protein-based solutions give background staining with routine hematoxylin and eosin, but the use of nonprotein-based solutions PVA and OCT reduces this background by 50%. These methods preserve the tissue architecture and cellular details with both in vitro PEG constructs and in constructs that have been implanted in vivo. This simple hydrogel cryosectioning technique improves the methodology for creation of good-quality histological sections from hydrogels in multiple applications. PMID:23448137

Ruan, Jia-Ling; Tulloch, Nathaniel L; Muskheli, Veronica; Genova, E Erin; Mariner, Peter D; Anseth, Kristi S; Murry, Charles E

2013-10-01

460

Human Ribonuclease with a Pendant Poly(Ethylene Glycol) Inhibits Tumor Growth in Mice1  

PubMed Central

Human pancreatic ribonuclease (RNase 1) is a small secretory protein that catalyzes the cleavage of RNA. This highly cationic enzyme can enter human cells spontaneously but is removed rapidly from circulation by glomerular filtration. Here, this shortcoming is addressed by attaching a poly(ethylene glycol) (PEG) moiety to RNase 1. The pendant has no effect on ribonucleolytic activity but does increase persistence in circulation. The RNase 1-PEG conjugates inhibit the growth of tumors in a xenograft mouse model of human lung cancer. Both retention in circulation and tumor growth inhibition correlate with the size of the pendant PEG. A weekly dose of the 60-kDa conjugate at 1 µmol/kg inhibited nearly all tumor growth without affecting body weight. Its molecular efficacy is ?5000-fold greater than that of erlotinib, which is a small molecule in clinical use for the treatment of lung cancer. These data demonstrate that the addition of a PEG moiety can enhance the in vivo efficacy of human proteins that act within cells and highlight a simple means of converting an endogenous human enzyme into a cytotoxin with potential clinical utility. PMID:23908681

Rutkoski, Thomas J; Kink, John A; Strong, Laura E; Raines, Ronald T

2013-01-01

461

An Improved Cryosection Method for Polyethylene Glycol Hydrogels Used in Tissue Engineering  

PubMed Central

The high water content of hydrogels allows these materials to closely mimic the native biological extracellular conditions, but it also makes difficult the histological preparation of hydrogel-based bioengineered tissue. Paraffin-embedding techniques require dehydration of hydrogels, resulting in substantial collapse and deformation, whereas cryosectioning is hampered by the formation of ice crystals within the hydrogel material. Here, we sought to develop a method to obtain good-quality cryosections for the microscopic evaluation of hydrogel-based tissue-engineered constructs, using polyethylene glycol (PEG) as a test hydrogel. Conventional sucrose solutions, which dehydrate cells while leaving extracellular water in place, produce a hydrogel block that is brittle and difficult to section. We therefore replaced sucrose with multiple protein-based and nonprotein-based solutions as cryoprotectants. Our analysis demonstrated that overnight incubation in bovine serum albumin (BSA), fetal bovine serum (FBS), polyvinyl alcohol (PVA), optimum cutting temperature (OCT®) compound, and Fisher HistoPrep frozen tissue-embedding media work well to improve the cryosectioning of hydrogels. The protein-based solutions give background staining with routine hematoxylin and eosin, but the use of nonprotein-based solutions PVA and OCT reduces this background by 50%. These methods preserve the tissue architecture and cellular details with both in vitro PEG constructs and in constructs that have been implanted in vivo. This simple hydrogel cryosectioning technique improves the methodology for creation of good-quality histological sections from hydrogels in multiple applications. PMID:23448137

Ruan, Jia-Ling; Tulloch, Nathaniel L.; Muskheli, Veronica; Genova, E. Erin; Mariner, Peter D.; Anseth, Kristi S.

2013-01-01

462

Drying and storage effects on poly(ethylene glycol) hydrogel mechanical properties and bioactivity.  

PubMed

Hydrogels based on poly(ethylene glycol) (PEG) are increasingly used in biomedical applications because of their ability to control cell-material interactions by tuning hydrogel physical and biological properties. Evaluation of stability after drying and storage are critical in creating an off-the-shelf biomaterial that functions in vivo according to original specifications. However, there has not been a study that systematically investigates the effects of different drying conditions on hydrogel compositional variables. In the first part of this study, PEG-diacrylate hydrogels underwent common processing procedures (vacuum-drying, lyophilizing, hydrating then vacuum-drying), and the effect of this processing on the mechanical properties and swelling ratios was measured. Significant changes in compressive modulus, tensile modulus, and swelling ratio only occurred for select processed hydrogels. No consistent trends were observed after processing for any of the formulations tested. The effect of storage conditions on cell adhesion and spreading on collagen- and streptococcal collagen-like protein (Scl2-2)-PEG-diacrylamide hydrogels was then evaluated to characterize bioactivity retention after storage. Dry storage conditions preserved bioactivity after 6 weeks of storage; whereas, storage in PBS significantly reduced bioactivity. This loss of bioactivity was attributed to ester hydrolysis of the protein linker, acrylate-PEG-N-hydroxysuccinimide. These studies demonstrate that these processing methods and dry storage conditions may be used to prepare bioactive PEG hydrogel scaffolds with recoverable functionality after storage. PMID:24123725

Luong, P T; Browning, M B; Bixler, R S; Cosgriff-Hernandez, E

2014-09-01

463

The effect of polyethylene glycol on the mechanics and ATPase activity of active muscle fibers.  

PubMed Central

We have used polyethylene glycol (PEG) to perturb the actomyosin interaction in active skinned muscle fibers. PEG is known to potentiate protein-protein interactions, including the binding of myosin to actin. The addition of 5% w/v PEG (MW 300 or 4000) to active fibers increased fiber tension and decreased shortening velocity and ATPase activity, all by 25-40%. Variation in [ADP] or [ATP] showed that the addition of PEG had little effect on the dissociation of the cross-bridge at the end of the power stroke. Myosin complexed with ADP and the phosphate analog V(i) or AlF(4) binds weakly to actin and is an analog of a pre-power-stroke state. PEG substantially enhances binding of these states both in active fibers and in solution. Titration of force with increasing [P(i)] showed that PEG increased the free energy available to drive the power stroke by about the same amount as it increased the free energy available from the formation of the actomyosin bond. Thus PEG potentiates the binding of myosin to actin in active fibers, and it provides a method for enhancing populations of some states for structural or mechanical studies, particularly those of the normally weakly bound transient states that precede the power stroke. PMID:10653805

Chinn, M K; Myburgh, K H; Pham, T; Franks-Skiba, K; Cooke, R

2000-01-01

464

Vascular tumor in metal-on-polyethylene THA requiring hemipelvectomy.  

PubMed

Total hip arthroplasty with metal-on-polyethylene implants and metal-on-metal articulations have been an area of recent interest. This article describes a patient with a persistent small soft tissue mass on the anterior groin following total hip arthroplasty with negative findings on infection workup, including blood work and aspiration. Subsequent biopsy findings were consistent with organizing thrombus and necrosis. It then developed into an expansile soft tissue groin mass with significant femoral and pelvic bony destruction and soft tissue infiltration. Metallosis, the formation of a pseudocapsule, and aseptic lymphocyte vasculitis-associated lesions have also been an area of interest following adult hip reconstruction. Occasionally, the formation of subsequent lesions make revision surgery impossible to perform due to bony destruction and soft tissue limitations. Although few in number, most studies or cases that have linked metal-on-metal implants to pseudotumors have been treated with revision surgery and replacement of articulating surfaces. This case highlights a metal-on-polyethylene total hip arthroplasty with a mass presenting with pseudotumor-like characteristics. However, final histology demonstrated fibroadipose tissue with fat necrosis and fibrosis, thickened vascular vessels, and diffuse chronic inflammation with lymphocytic infiltrates, which are more consistent with an atypical inflammatory vascular tumor. The current case illustrates treatment difficulties and provides surgical options for when this event occurs. Although aseptic lymphocyte vasculitis-associated lesions have been observed with metal-on-polyethylene articulations, the multiorgan involvement in this case is unique. In this case, radical excision with hemipelvectomy and complex flap closure was a last resort treatment solution that staved off the prospect of patient mortality. PMID:23823059

Lee, Jason H; Le, Vu H; Steinhoff, Amy; Hoang, Bang H

2013-07-01

465

Growth of ZnO nanowires on nonwoven polyethylene fibers  

NASA Astrophysics Data System (ADS)

We report the growth of ZnO nanowires on nonwoven polyethylene fibers using a simple hydrothermal method at a temperature below the boiling point of water. The ZnO nanowires were grown from seed ZnO nanoparticles affixed onto the fibers. The seed ZnO nanoparticles, with diameters of about 6-7 nm, were synthesized in isopropanol by reducing zinc acetate hydrate with sodium hydroxide. The growth process was carried out in a sealed chemical bath containing an equimolar solution of zinc nitrate hexahydrate and hexamethylene tetramine at a temperature of 95 °C over a period of up to 20 h. The thickness and length of the nanowires can be controlled by using different concentrations of the starting reactants and growth durations. A 0.5 mM chemical bath yielded nanowires with an average diameter of around 50 nm, while a 25 mM bath resulted in wires with a thickness of up to about 1 ?m. The length of the wires depends both on the concentration of the precursor solution as well as the growth duration, and in 20 h, nanowires as long as 10 ?m can be grown. The nonwoven mesh of polyethylene fibers covered with ZnO nanowires can be used for novel applications such as water treatment by degrading pollutants by photocatalysis. Photocatalysis tests carried out on standard test contaminants revealed that the polyethylene fibers with ZnO nanowires grown on them could accelerate the photocatalytic degradation process by a factor of 3.

Baruah, Sunandan; Thanachayanont, Chanchana; Dutta, Joydeep

2008-04-01

466

Rheological and NMR studies of polyethylene/calcium carbonate composites.  

PubMed

Rheometry, 13C CP/MAS NMR spectra and 1H spin-lattice relaxation times T1 and T1rho have been employed to study the structure and molecular dynamics in composites of polyethylene (LDPE) with calcium carbonate filler. It has been found that the addition of the filler into the polymer leads to an increase in composite rigidity and a decrease in mobility in its crystalline regions. The presence of the filler affects the crystallization process making the crystal structure less perfect and reduces the size of the crystallites. PMID:14698410

Nowaczyk, G; G?owinkowski, S; Jurga, S

2004-01-01

467

Substrate effect on the melting temperature of thin polyethylene films.  

PubMed

Strong dependence of the crystal orientation, morphology, and melting temperature (Tm) on the substrate is observed in the semicrystalline polyethylene thin films. The Tm decreases with the film thickness decrease when the film is thinner than a certain critical thickness, and the magnitude of the depression increases with increasing surface interaction. We attribute the large Tm depression to the decrease in the overall free energy on melting, which is caused by the substrate attraction force to the chains that competes against the interchain force which drives the chains to crystallization. PMID:16486656

Wang, Y; Rafailovich, M; Sokolov, J; Gersappe, D; Araki, T; Zou, Y; Kilcoyne, A D L; Ade, H; Marom, G; Lustiger, A

2006-01-20

468

Deuterated polyethylene coatings for ultra-cold neutron applications  

E-print Network

We report on the fabrication and use of deuterated polyethylene (dPE) 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 $\\eta$ is 2$\\cdot$10$^4$ per wall collision. The coating technique allows for a wide range of applications and new possibilities in this field of physics. In particular, flexible and quasi-massless UCN guides with slit-less shutters and slit-less UCN storage volumes become possible. These properties enable the use in next-generation measurements of the electric dipole moment of the neutron.

Altarev, I; Fierlinger, P; Geltenbort, P; Gutsmiedl, E; Kuchler, F; Lauer, T; Lins, T; Marino, M G; Niessen, B; Petzoldt, G; Ruhstorfer, D; Seeman, K M; Soltwedel, O; Stuiber, St; Taubenheim, B; Windmayer, D; Zechlau, T

2015-01-01

469

Pyrolysis Pathways of Sulfonated Polyethylene, an Alternative Carbon Fiber Precursor  

SciTech Connect

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.

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

2013-01-01

470

Polyethylene glycol-based homologated ligands for nicotinic acetylcholine receptors?  

PubMed Central

A homologous series of polyethylene glycol (PEG) monomethyl ethers were conjugated with three ligand series for nicotinic acetylcholine receptors. Conjugates of acetylaminocholine, the cyclic analog 1-acetyl-4,4-dimethylpiperazinium, and pyridyl ether A-84543 were prepared. Each series was found to retain significant affinity at nicotinic receptors in rat cerebral cortex with tethers of up to six PEG units. Such compounds are hydrophilic ligands which may serve as models for fluorescent/affinity probes and multivalent ligands for nAChR. PMID:19006672

Scates, Bradley A.; Lashbrook, Bethany L.; Chastain, Benjamin C.; Tominaga, Kaoru; Elliott, Brandon T.; Theising, Nicholas J.; Baker, Thomas A.; Fitch, Richard W.

2010-01-01

471

Branched carbon nanotube reinforcements for improved strength of polyethylene nanocomposites  

NASA Astrophysics Data System (ADS)

A bio-inspired design of polyethylene nanocomposites is presented in this letter using branched carbon nanotubes (BCNTs) as reinforcements. Using coarse-grained molecular dynamics simulations, we demonstrate that the pullout strength of the proposed BCNT nanofibers can be an order of magnitude higher than that of CNT reinforcements. The drastically improved interfacial shearing strength is found to be strongly dependent on the geometry of nanofibers, the molecular weight of matrix polymers, and the pullout velocity. By analyzing the time-evolving molecular configurations of BCNT nanofibers and surrounding polymer chains, the underlying strengthening mechanisms are discussed and strategies for further improvement are suggested.

Liu, Ling; Zhang, Lin; Lua, Jim

2012-10-01

472

Fabrication of complete denture bases reinforced with polyethylene woven fabric.  

PubMed

Incorporation of 5 layers of woven, high-modulus polyethylene fiber into acrylic resin denture bases produces substantial improvements in mechanical properties and dimensional changes. A modified split-pack technique has been developed using conventional dental-laboratory compression molding to accommodate multiple layers of woven fabric in complete denture bases. A recess formed in the resin by a spacer allows the reinforcement to be embedded in the denture base without exposing the fibers. Embedded fibers do not compromise the esthetics of complete dentures. PMID:10895680

Cheng, Y Y; Chow, T W

1999-12-01

473

Effective UV radiation dose in polyethylene exposed to weather  

NASA Astrophysics Data System (ADS)

In this work we quantified the effective UV radiation dose in orange and colorless polyethylene samples exposed to weather in the city of Aguascalientes, Ags. Mexico. The spectral distribution of solar radiation was calculated using SMART 2.9.5.; the samples absorption properties were measured using UV-Vis spectroscopy and the quantum yield was calculated using samples reflectance properties. The determining factor in the effective UV dose is the spectral distribution of solar radiation, although the chemical structure of materials is also important.

González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Calero Marín, S. P.; Vega-Durán, J. T.; Moreno-Virgen, R.

2009-09-01

474

40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p...Substances § 721.4040 Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p...chemical substance identified as glycols, polyethylene-,...

2012-07-01

475

40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p...Substances § 721.4040 Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p...chemical substance identified as glycols, polyethylene-,...

2011-07-01

476

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

E-print Network

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 ...

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

2003-01-01

477

Particle Size Control of Polyethylene Glycol Coated Fe Nanoparticles  

NASA Astrophysics Data System (ADS)

Recent interest in Fe nanoparticles with high magnetization is driven by their potential use in biomedical applications such as targeted drug delivery, MRI contrast enhancement and hyperthermia treatment of cancer. This study looks at the use of a polyethylene glycol (PEG) solution to mediate the particle size and therefore control the coercivity of the resulting nanoparticles. Iron nanoparticles were synthesized using an aqueous sodium borohydride reduction of ferrous chloride by a simultaneous introduction of reagents in a Y- junction. The resulting product was collected in a vessel containing a 15 mg/ml carboxyl terminated polyethylene glycol (cPEG) in ethyl alcohol solution located under the Y junction. By varying the length of tubing below the Y junction, the particle size was varied from 5-25 nm. X-ray diffraction data indicates the presence of either amorphous Fe-B or crystalline alpha Fe, depending on the molar ratio of reagents. Magnetic measurements indicate the particles are ferromagnetic with values of coercivity ranging from 200-500 Oe and a saturation magnetization in range of 70-110 emu/g. The XRD shows that the particles are not affected by the polymer coating.

Srinivasan, B.; Bonder, M. J.; Zhang, Y.; Gallo, D.; Hadjipanayis, G. C.

2006-03-01

478

Migration of wear debris of polyethylene depends on bone microarchitecture.  

PubMed

The mechanism of hip arthroplasties loosening is related to the migration of wear debris throughout the implant environment. In vivo, polyethylene particles (PE) were shown to infiltrate the bone implant interface and the medullary spaces of the cancellous bone. Our test hypothesis was that polyethylene particle migration is correlated to bone porosity. Bone samples with a high or low trabecular volume and microarchitecture were harvested in 20 calves and 20 human cadavers. They were extensively washed to remove marrow cells. Bone cylinders were filled with a light-curing monomer having the same viscosity as bone marrow. PE particles (7 and 33 microm) were deposited at the surface of the polymer. The bone cylinders were agitated during 7 days on an orbital shaker and the gel was left to polymerize at day light. X-ray microtomography was performed to characterize bone volume and microarchitecture. Cylinders were sectioned and observed under polarized light. The migration distance and rate were determined. Migration of PE particles strongly depended on trabecular bone volume and microarchitecture. We found a linear relationship (r = 0.61) between speed migration and bone volume and an exponential relationship between speed migration and bone architecture. The present in vitro model confirmed our hypothesis about the key role of bone microarchitecture in the migration of large PE wear particles. This is an explanation for the development of inflammatory reaction at distance from a prosthesis although our study did not include submicron particles. PMID:19235207

Libouban, Hélène; Massin, Philippe; Gaudin, Christine; Mercier, Philippe; Baslé, Michel F; Chappard, Daniel

2009-08-01

479

Effect of thermal modification on rheological properties of polyethylene blends  

SciTech Connect

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.

Siriprumpoonthum, Monchai; Nobukawa, Shogo; Yamaguchi, Masayuki, E-mail: m-yama@jaist.ac.jp [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Satoh, Yasuo; Sasaki, Hiroko [Packaging and Industrial Materials Laboratory, Prime Polymer Co., Ltd., 3 Chigusa-kaigan, Ichihara, Chiba 299-0108 (Japan)

2014-03-15

480

Platelet deposition studies on copolyether urethanes modified with poly(ethylene oxide)  

Microsoft Academic Search

Pellethane ® 2363 80A films and tubings were chemically modified and the effect of these modifications on platelet deposition was studied. Grafting of high molecular weight poly(ethylene oxide) and graft polymerization of methoxy poly(ethylene glycol) 400 methacrylate resulted in surfaces with a good water wettability. The increased hydrophilicity of these modified surfaces could be demonstrated by contact angle measurements. The

E. Brinkman; A. Foot; Does van der L; A. Bantjes

1990-01-01

481

Surface induced disorder of nematic MBBA near silica with grafted poly(ethylene oxide)  

E-print Network

909 Surface induced disorder of nematic MBBA near silica with grafted poly(ethylene oxide) H. Ben with grafted polymers poly(ethylene oxide) 2000, has been investigated by the electron paramagnetic resonance different. This paper describes the effect of macromolecules, namely poly- (ethylene oxide), grafted i

Paris-Sud XI, Université de

482

Hydrolytic Degradation of Poly(ethylene oxide)-block-Polycaprolactone Worm Micelles  

E-print Network

Hydrolytic Degradation of Poly(ethylene oxide)-block-Polycaprolactone Worm Micelles Yan Geng micelles prepared from degradable poly- (ethylene oxide)-b-poly( -caprolactone) copolymers (PEO polyesters, typically polylactide or polycaprolactone, plus a hydrophilic, biocompatible block such as poly(ethylene

Discher, Dennis

483

Thermal Oxidative Degradation of Poly(ethylene glycol) Helge Egsgaard1  

E-print Network

Thermal Oxidative Degradation of Poly(ethylene glycol) Helge Egsgaard1 , Martin Nordvig Mortensen2/z Relativeintensity - CH3OH Introduction Poly(ethylene glycol) (PEG) finds a number of unique applications, e.g. PEG 1500 following oxidation & hydrolysis 0 20 40 60 80 100 120 1000 1200 1400 1600 1800 2000 m

484

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

E-print Network

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

Chung, Deborah D.L.

485

Acute Repair of Crushed Guinea Pig Spinal Cord by Polyethylene Glycol  

E-print Network

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

Shi, Riyi

486

Leaf Area Distribution of Tomato Plants as Influenced by Polyethylene Mulch  

E-print Network

Leaf Area Distribution of Tomato Plants as Influenced by Polyethylene Mulch Surface Color Dennis R of polyethylene (plastic) mulch surface color (white versus black) on leaf area distribution of tomato, tomato plants grown with white mulch had more axillary leaves than plants in the black mulch, resulting

Decoteau, Dennis R.

487

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...

488

Reconstruction of the microtic external ear in adults using porous polyethylene implant  

Microsoft Academic Search

Autogenous rib cartilage and many other materials have been used for external ear reconstruction. Although the most commonly used material is the former, harvesting, carving and shaping are problems. Recently, porous polyethylene implants have proved to be useful for ear reconstruction. Ten ear reconstructions were performed in adults using porous polyethylene implants over the last two years. The patients were

M. ?engezer; M. Tiiregiin; S. I?ik; M. Sezgin

1996-01-01

489

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution  

E-print Network

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution-resolved small-angle neutron scattering (TR-SANS), the crystal- lization kinetics of polyethylene from deuterated (PE); neutron scattering INTRODUCTION Crystallization of long-chain molecules has been extensively

Wang, Howard "Hao"

490

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

Federal Register 2010, 2011, 2012, 2013, 2014

...that a U.S. industry is threatened...Polyethylene Retail Carrier Bags...all relevant entries of PRCBs from...liquidation of entries since the Department's...Polyethylene Retail Carrier Bags...unliquidated entries of PRCBs from...to a U.S. industry, the...

2010-05-04

491

Impact of gamma sterilization on clinical performance of polyethylene in the knee  

Microsoft Academic Search

Damage and rapid wear of the ultrahigh-molecular-weight polyethylene bearings of knee components continue to be major sources of failure of knee prostheses. Despite considerable research into the roles of design, polyethylene thickness and quality, and component alignment, the source of the rapid wear failures has remained a mystery. This study documents elevated oxidation resulting from the use of gamma sterilization

John P. Collier; Daniel K. Sperling; John H. Currier; Lauren C. Sutula; Kenneth A. Saum; Michael B. Mayor

1996-01-01

492

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...

493

Accepted Manuscript Kinetic Modelling of High Density PolyEthylene Pyrolysis: Part 1. Comparison of  

E-print Network

Accepted Manuscript Kinetic Modelling of High Density PolyEthylene Pyrolysis: Part 1. Comparison this article as: Gascoin N, Navarro-Rodriguez A, Gillard P, Mangeot A, Kinetic Modelling of High Density PolyEthylene.polymdegradstab.2012.05.008 #12;M ANUSCRIPT ACCEPTED ACCEPTED MANUSCRIPT 1 Kinetic Modelling of High Density PolyEthylene

Paris-Sud XI, Université de

494

Meta-analysis and cost comparison of polyethylene glycol lavage versus sodium phosphate for colonoscopy preparation  

Microsoft Academic Search

Background: Although polyethylene glycol lavage solutions are widely used for colonoscopy preparation, evidence suggests that sodium phosphate is better tolerated and has similar efficacy. The purpose of this study was to compare compliance with and efficacy of polyethylene glycol and sodium phosphate using meta-analysis and to compare the cost of colonoscopy with both methods. Methods: We used Medline to identify

Chia-Wen Hsu; Thomas F. Imperiale

1998-01-01

495

Antioxidant Content of and Migration from Commercial Polyethylene, Polypropylene, and Polyvinyl Chloride Packages  

Microsoft Academic Search

Antioxidants commonly used in polyolefins were studied in commercial food packages made of low- and high-density polyethylene (LDPE and HDPE), polypropylene (PP), polyvinylchloride (PVC), and polyethylene terephtalate (PET) and in a LDPE film extruded at the laboratory. The phenolic antioxidants BHA, BHT, AO 2246, AO 425, Ethanox 330, Irganox 1010, and Irganox 1076 were studied together with the phosphite Irgafos

M. S. Dopico-García; J. M. López-Vilariñó; M. V. González-Rodríguez

2007-01-01

496

The influence of soil macroinvertebrates on primary biodegradation of starch-containing polyethylene films  

Microsoft Academic Search

The primary biodegradability of polyethylene (PE) films containing different percentages of cornstarch (0–50%) and other additives (prooxidant, oxidized polyethylene) was tested using four species of earthworms (Eisenia fetida, Lumbricus terrestris, Aporectodea trapezoides, Aporectodea tuberculata), three species of cockroaches (Periplaneta americana, Blaberus sp.,Blattella germanica), termites (Reticulotermes flavipes), sowbugs (Porcellio laevis), and crickets (Acheta domesticus). These studies were conducted to elucidate the

Rong Tsao; Todd A. Anderson; Joel R. Coats

1993-01-01

497

Complete genome sequence of Bacillus sp. YP1, a polyethylene-degrading bacterium from waxworm's gut.  

PubMed

Bacillus sp. strain YP1, isolated from the gut of waxworm (the larvae of Plodia interpunctella) which ate polyethylene (PE) plastic, is capable of degrading PE and utilizing PE as sole carbon source. Here we report the complete genome sequence of strain YP1, which is relevant to polyethylene depolymerization and biodegradation. PMID:25795022

Yang, Yu; Chen, Jianwei; Wu, Wei-Min; Zhao, Jiao; Yang, Jun

2015-04-20

498

Comparison of low-energy radiation effects in polyethylene and cellulose Jussi Polvi, Kai Nordlund  

E-print Network

Comparison of low-energy radiation effects in polyethylene and cellulose Jussi Polvi, Kai Nordlund and cellulose. We determined the threshold energy for creating defects as a function of the incident angle, for a carbon atom in polyethylene chain, and for one of the carbon atoms in cellulose chain. Our analysis shows

Nordlund, Kai

499

Chemical group in crosslinking byproducts responsible for charge trapping in polyethylene  

Microsoft Academic Search

It is known that space charge is formed in cables insulated with crosslinked polyethylene. It is probable that the crosslinking byproduct or the crosslinked polymer morphology is responsible for the space charge. In order to examine the former possibility, an additive-free low-density polyethylene sheet was soaked in various liquid chemicals including the crosslinking byproducts and space charge distribution inside the

Naoshi Hirai; R. Minarni; Toshikatsu Tanaka; Yoshimichi Ohki; M. Okashita; T. Maeno

2003-01-01

500

Chemical group in crosslinking byproducts responsible for charge trapping in polyethylene  

Microsoft Academic Search

It is known that space charge is formed in cables insulated with crosslinked polyethylene. It is probable that the crosslinking byproduct or the crosslinked polymer morphology is responsible for the space charge. In order to examine the former possibility, an additive-free low-density polyethylene sheet was soaked in various liquid chemicals including the crosslinking byproducts and space charge distribution inside the

Naoshi Hirai; Ryotaro Minami; Toshikatsu Tanaka; Yoshimichi Ohki; Minoru Okashita; Takashi Maeno

2002-01-01