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Sample records for acid-ethylene glycol dimethacrylate

  1. Perfluorotriethylene glycol dimethacrylate modified composite resins for improved dental restoratives

    NASA Astrophysics Data System (ADS)

    Wang, Guigui

    The studies described in this dissertation focus on improvement of water resistance and durability of current dental composite resins. The physical, thermal and mechanical properties of the diluent fluorinated monomer, perfluorotriethylene glycol methacrylate (FTEGDMA), FTEGDMA-containing neat resin and its formulated composite resins were evaluated and compared with the conventional visible light-cured (VLC) dental composite resins. Further, the biocompatibility of this monomer and its cured resins were investigated and compared with their conventional counterparts. The results showed that the FTEGDMA-containing neat resin and its composite systems showed more water resistance and longer durability, compared to the conventional Bisphenol A glycol dimethacrylate/triethylene glycol dimethacrylate (BisGMA/TEGDMA) system. The preliminary in vitro biocompatibility test showed that FTEGDMA favored cell growth, compared to the conventional dental resins. The first study investigated basic physical properties of the diluent FTEGDMA monomer. The results showed that the FTEGDMA exhibited lower viscosity, lower refractive index, and a smaller contact angle, which were all beneficial to lowering the water sorption and increasing hydrophobicity. The second study evaluated some physical, thermal, and mechanical properties of the FTEGDMA based neat resins, including polymerization shrinkage, contact angle, water sorption, glass-transitions, dynamic modulus, thermal expansion, compressive strength, and diametral tensile strength. The results showed that the FTEGDMA diluent exhibited significant less water sorption and lower polymerization shrinkage and the BisEMA also contributed towards reducing water sorption. The third study investigated the effects of the FTEGDMA on the mechanical properties of the composite resins including flexural strength (FS), diametral tensile strength (DTS) and wear resistance (WR). In addition, the fracture surface topography of the tested materials

  2. Radiation-grafting of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) onto silicone rubber

    NASA Astrophysics Data System (ADS)

    Flores-Rojas, G. G.; Bucio, E.

    2016-10-01

    Silicone rubber (SR) was modified with a graft of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) using either gamma-radiation or azobisisobutyronitrile (AIBN). The graft efficiency was evaluated as a function of monomer concentration, absorbed dose, reaction temperature, and concentration of AIBN. The hydrophilicity of the grafted films was measured by contact angle and their equilibrium swelling time in ethanol. Additional characterization by infrared (FTIR-ATR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is also reported.

  3. Poly(N-vinylimidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids.

    PubMed

    Schemeth, Dieter; Noël, Jean-Christophe; Jakschitz, Thomas; Rainer, Matthias; Tessadri, Richard; Huck, Christian W; Bonn, Günther K

    2015-07-23

    In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC-qTOF-MS.

  4. Real-time monitoring of molecular dynamics of ethylene glycol dimethacrylate glass former.

    PubMed

    Viciosa, M T; Correia, N T; Salmerón Sanchez, M; Carvalho, A L; Romão, M J; Gómez Ribelles, J L; Dionísio, M

    2009-10-29

    The isothermal cold-crystallization of the glass-former low-molecular-weight compound, ethylene glycol dimethacrylate (EGDMA), was monitored by real-time dielectric relaxation spectroscopy (DRS) and differential scanning calorimetry (DSC). The alpha-relaxation associated with the dynamic glass transition as detected by DRS was followed at different crystallization temperatures, T(cr), nearly above the glass transition temperature, 176 K (1.06 < or = T(cr)/T(g) < or = 1.12). It was found that the alpha-process depletes upon cold-crystallization with no significant changes in either shape or location. At advanced crystallization states, a new relaxation, alpha'-process, evolves that was assigned to the mobility of molecules lying adjacent to crystalline surfaces. From the time evolution of the normalized permittivity, it was possible to get kinetic information that was complemented with the calorimetric data. From DSC measurements that were also carried out under melt-crystallization, an enlarged temperature range was covered (up to T(cr)/T(g) = 1.24), allowing us to draw a diagram of time-temperature crystallization for this system. Dielectric relaxation spectroscopy proved to be a sensitive tool to probe the mobility in the remaining amorphous regions even at high crystallinities. PMID:19803485

  5. Performance improvement of injectable poly(ethylene glycol) dimethacrylate-based hydrogels with finely dispersed hydroxyapatite.

    PubMed

    Zhou, Ziyou; Ren, Yongjuan; Yang, Dongzhi; Nie, Jun

    2009-06-01

    Injectable hydrogels are attractive materials for biomedical application. In this work, a chemical mixing technique was developed to promote the dispersion of hydroxyapatite (HA) in injectable poly(ethylene glycol) dimethacrylate (PEGDMA)-based hydrogels. Nano-sized HA particles were distributed homogenously within the organic network, whereby HA crystals were formed in the presence of PEGDMA macromers. In addition, hydrogels were also prepared by physical mixing of dry HA particles with PEGDMA, as a comparison. Transmission electron microscopy was used to evaluate the morphology and crystal structure of HA formed in the PEGDMA aqueous solution before polymerization. According to Fourier transform infrared spectra and x-ray diffraction results, hydrogels prepared by different methods have similar components and crystal structures. Scanning electron microscopy was used to observe the hydrogels' morphology, which showed that HA in hydrogels made by chemical mixing was well dispersed and nano sized. Mechanical evaluation indicated that the mean value of the compressive strength and modulus of hydrogels prepared by physical mixing were 0.137 MPa and 0.518 MPa, respectively, while those of hydrogels prepared by chemical mixing were 0.290 MPa and 0.696 MPa, respectively. Furthermore, temperature measurement showed that the mean value of the maximum temperature in the crosslinking process of hydrogels made by chemical mixing was 38.0 degrees C, which was significantly lower than that of for hydrogels made by physical mixing (38.6 degrees C). The results indicated that the performance of composite hydrogels could be promoted by chemical mixing of the inorganic network into a polymer network.

  6. SPME and GC-MS analysis of triethylene glycol dimethacrylate released from dental composite.

    PubMed

    Djozan, Djavanshir; Jozan, Saeed; Aminian, Roya; Baheri, Tahmineh

    2010-02-01

    A solid-phase microextraction (SPME) coupled with gas chromatography followed by mass spectrometry was developed for the determination of triethylene glycol dimethacrylate (TEGDMA) in aqueous media originated from cured dental composite. Cylindrical specimens of a common dental composite were cured and immersed for 48 h in 3 mL portions of human saliva and also some non-biologic media e.g., pure water and Ringer's solution. The extraction was carried out by direct SPME for 15 min. The efficiency and reliability of some commercially available and modified pencil lead fibers were evaluated for the extraction of interest compound from aqueous media. Some effective and experimental parameters of SPME and gas chromatography procedures were examined and optimized. The obtained results reveal that the direct SPME using the modified pencil lead is very effective and can extract TEGDMA with a good selectivety from among various compounds such as 2,6-di-tert-butyl-4-methyl phenol (buylated hydroxy toluene) (BHT), 2-propenoic acid, 2-methyl-oxybis (2,1-ethanediyl oxy-2,1-ethanediyl) ester (TEEGDMA), 3,5-di-t-butyl-4-hydroxy benzaldehyde, benzoic acid 4 (dimethyl-amino)-ethyl ester (DMA BEE), 2-propenoic acid, 2-methyl-dodecyl ester (methacrylic acid, dodecyl ester), 2-ethoxy ethyl methacrylate, and drometrizole (TINP). The results obtained also prove that the studied composite releases 11.0, 13.4, and 28.3 microg/mL TEGDMA into distilled water, Ringer's solution, and saliva, respectively, at 48 h of the exposition. PMID:20109291

  7. The Influence of Irradiation Time and Layer Thickness on Elution of Triethylene Glycol Dimethacrylate from SDR® Bulk-Fill Composite.

    PubMed

    Łagocka, Ryta; Jakubowska, Katarzyna; Chlubek, Dariusz; Buczkowska-Radlińska, Jadwiga

    2016-01-01

    Objective. This study aimed to evaluate triethylene glycol dimethacrylate (TEGDMA) elution from SDR bulk-fill composite. Methods. Three groups of samples were prepared, including samples polymerized in a 4 mm layer for 20 s, in a 4 mm layer for 40 s, and in a 2 mm layer for 20 s. Elution of TEGDMA into 100% ethanol, a 75% ethanol/water solution, and distilled water was studied. The TEGDMA concentration was measured using HPLC. Results. The TEGDMA concentration decreased in the following order: 100% ethanol > 75% ethanol > distilled water. Doubling the energy delivered to the 4 mm thick sample caused decrease (p < 0.05) in TEGDMA elution to distilled water. In ethanol solutions, the energy increase had no influence on TEGDMA elution. Decreasing the sample thickness resulted in decrease (p < 0.05) in TEGDMA elution for all the solutions. Conclusions. The concentration of eluted TEGDMA and the elution time were both strongly affected by the hydrophobicity of the solvent. Doubling the energy delivered to the 4 mm thick sample did not decrease the elution of TEGDMA but did decrease the amount of the monomer available to less aggressive solvents. Elution of TEGDMA was also correlated with the exposed sample surface area. Clinical Relevance. Decreasing the SDR layer thickness decreases TEGDMA elution. PMID:27366742

  8. The Influence of Irradiation Time and Layer Thickness on Elution of Triethylene Glycol Dimethacrylate from SDR® Bulk-Fill Composite

    PubMed Central

    Jakubowska, Katarzyna; Chlubek, Dariusz; Buczkowska-Radlińska, Jadwiga

    2016-01-01

    Objective. This study aimed to evaluate triethylene glycol dimethacrylate (TEGDMA) elution from SDR bulk-fill composite. Methods. Three groups of samples were prepared, including samples polymerized in a 4 mm layer for 20 s, in a 4 mm layer for 40 s, and in a 2 mm layer for 20 s. Elution of TEGDMA into 100% ethanol, a 75% ethanol/water solution, and distilled water was studied. The TEGDMA concentration was measured using HPLC. Results. The TEGDMA concentration decreased in the following order: 100% ethanol > 75% ethanol > distilled water. Doubling the energy delivered to the 4 mm thick sample caused decrease (p < 0.05) in TEGDMA elution to distilled water. In ethanol solutions, the energy increase had no influence on TEGDMA elution. Decreasing the sample thickness resulted in decrease (p < 0.05) in TEGDMA elution for all the solutions. Conclusions. The concentration of eluted TEGDMA and the elution time were both strongly affected by the hydrophobicity of the solvent. Doubling the energy delivered to the 4 mm thick sample did not decrease the elution of TEGDMA but did decrease the amount of the monomer available to less aggressive solvents. Elution of TEGDMA was also correlated with the exposed sample surface area. Clinical Relevance. Decreasing the SDR layer thickness decreases TEGDMA elution. PMID:27366742

  9. Reproductive toxicity evaluation of the dental resin monomer triethylene glycol dimethacrylate (CASRN 109-16-0) in mice.

    PubMed

    Moilanen, Lori H; Dahms, Janell K; Hoberman, Alan M

    2014-01-01

    The reproductive toxicity potential of the resin monomer triethylene glycol dimethacrylate (TEGDMA; Chemical Abstracts Service Registry Number 109-16-0) was investigated in male and female Crl:CD1(ICR) mice, 4 dosage groups, 25 mice/sex/group. Formulations of TEGDMA (0, 0.01, 0.1, or 1.0 mg/kg/d) in reverse osmosis-processed deionized water were intubated once daily beginning 28 days before cohabitation and continuing through mating (males) or through gestation day 17 (females). The following parameters were evaluated: viability, clinical signs, body weights, estrous cyclicity, necropsy observations, organ weights, sperm concentration/motility/morphology, cesarean-sectioning and litter observations, and histopathological evaluation of select tissues. No deaths or clinical signs related to TEGDMA occurred. No significant changes in male and female body weights and body weight gains were recorded for any of the administered dosages of TEGMDA. All mating and fertility parameters and all litter and fetal data were considered to be unaffected by dosages of TEGMDA as high as 1 mg/kg/d. Gross or histopathologic tissue changes attributable to the test article were not observed. Reproductive and developmental no observed adverse effect levels (NOAELs) for TEGMDA were 1.0 mg/kg/d, the highest dose tested. Comparison of conservatively estimated TEGDMA exposures from dental treatments to the NOAEL of 1.0 mg/kg/d identified in this study indicates margins of exposure of at least 120- to 3000-fold depending on the exposure scenario. The results of this study support the continued safe use of TEGDMA in polymeric dental products applied according to the manufacturers' instructions.

  10. Preparation, loading, and cytotoxicity analysis of polymer nanotubes from an ethylene glycol dimethacrylate homopolymer in comparison to multi‐walled carbon nanotubes

    PubMed Central

    Thomas, Laurent; Zheng, Yu; Steinhart, Martin; Werner, Carsten; Wang, Wenxin

    2016-01-01

    Abstract Despite concerns over toxicity, carbon nanotubes have been extensively investigated for potential applications in nanomedicine because of their small size, unique properties, and ability to carry cargo such as small molecules and nucleic acids. Herein, we show that polymer nanotubes can be synthesized quickly and easily from a homopolymer of ethylene glycol dimethacrylate (EGDMA). The nanotubes formed via photo‐initiated polymerization of the highly functional prepolymer, inside an anodized aluminium oxide template, have a regular structure and large internal pore and can be loaded with a fluorescent dye within minutes representing a simple alternative to multi‐walled carbon nanotubes for biomedical applications. PMID:27512602

  11. Final report of the Cosmetic Ingredient Review Expert Panel safety assessment of polymethyl methacrylate (PMMA), methyl methacrylate crosspolymer, and methyl methacrylate/glycol dimethacrylate crosspolymer.

    PubMed

    Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2011-05-01

    Polymethyl methacrylate (PMMA) and related cosmetic ingredients methyl methacrylate crosspolymer and methyl methacrylate/glycol dimethacrylate crosspolymer are polymers that function as film formers and viscosity-increasing agents in cosmetics. The Food and Drug Administration (FDA) determination of safety of PMMA use in several medical devices, which included human and animal safety data, was used as the basis of safety of PMMA and related polymers in cosmetics by the Cosmetic Ingredient Review (CIR) Expert Panel.  The PMMA used in cosmetics is substantially the same as in medical devices.  The Panel concluded that these ingredients are safe as cosmetic ingredients in the practices of use and concentrations as described in this safety assessment. PMID:21772027

  12. Adsorption induced enzyme denaturation: the role of protein surface in adsorption induced protein denaturation on allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymers.

    PubMed

    Thudi, Lahari; Jasti, Lakshmi S; Swarnalatha, Y; Fadnavis, Nitin W; Mulani, Khudbudin; Deokar, Sarika; Ponrathnam, Surendra

    2012-02-01

    The effects of protein size on adsorption and adsorption-induced denaturation of proteins on copolymers of allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) have been studied. Different responses were observed for the amount of protein adsorbed and denatured on the polymer surface for different proteins (trypsin, alchol dehydrogenase from baker's yeast (YADH), glucose dehydrogenase (GDH) from Gluconobacter cerinus, and alkaline phosphates from calf intestinal mucosa (CIAP). Protein adsorption on the copolymer with 25% crosslink density (AGE-25) was dependent not only on the size of the protein but also on the presence of glycoside residues on the protein surface. Adsorption and denaturation of proteins follows the order YADH>trypsin>GDH>CIAP although the molecular weights of the proteins follow the order YADH>CIAP>GDH>trypsin. The lack of correlation between amount of adsorbed protein and its molecular weight was due to the presence of glycoside residues on CIAP and GDH which protect the enzyme surface from denaturation. Enzyme stabilities in aqueous solutions of 1-cyclohexyl-2-pyrrolidinone (CHP) correlate well with the trend in denaturation by the copolymer, strongly suggesting that hydrophobic interactions play a major role in protein binding and the mechanism of protein denaturation is similar to that for water-miscible organic solvents.

  13. Mechanism of Cu(II), Cd(II) and Pb(II) ions sorption from aqueous solutions by macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)

    NASA Astrophysics Data System (ADS)

    Nastasović, Aleksandra B.; Ekmeščić, Bojana M.; Sandić, Zvjezdana P.; Ranđelović, Danijela V.; Mozetič, Miran; Vesel, Alenka; Onjia, Antonije E.

    2016-11-01

    The mechanism of Cu(II), Cd(II) and Pb(II) ions sorption from aqueous solutions by macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (PGME) functionalized by reaction of the pendant epoxy groups with diethylene triamine (PGME-deta) was studied using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis. Atomic force microscopy (AFM) and scanning energy-dispersive X-ray spectroscopy (SEM-EDX) were used for the determination of surface morphology of the copolymer particles. The sorption behavior of heavy metals Cu(II), Cd(II) and Pb(II) ions sorption was investigated in batch static experiments under non-competitive conditions at room temperature (298 K). The obtained results were fitted to pseudo-first order, pseudo-second order and intraparticle diffusion kinetic model. The kinetics studies showed that Cu(II), Cd(II) and Pb(II) sorption obeys the pseudo-second-order model under all investigated operating conditions with evident influence of pore diffusion.

  14. Direct-write femtosecond laser ablation and DNA combing and imprinting for fabrication of a micro/nanofluidic device on an ethylene glycol dimethacrylate polymer

    NASA Astrophysics Data System (ADS)

    Lim, Y. C.; Boukany, P. E.; Farson, D. F.; Lee, L. J.

    2011-01-01

    Arrays of microwells connected by nanoscale channels with sizes on the order of 10 nm can be created in an ethylene glycol dimethacrylate (EGMDA) polymer using the DNA combing and imprinting technique. Larger micro-scale channels which lead into the microwell/nanochannel arrays are needed to allow the arrays to be externally filled with desired reagents, molecules and cells. In this work, direct-write femtosecond laser ablation was employed as a post process to fabricate these microscale filling channels. Single pulse and multiple pulses overlap ablation was first conducted on an EGMDA polymer using a focused femtosecond laser beam. Scanning electron microscopy was employed to measure the ablated channel width. Single pulse ablation threshold fluence and incubation coefficient were found and were used to predict microchannel width. Finally, femtosecond laser ablation was used to fabricate filling channels on microwell/nanochannel arrays. Fluorescent flow testing was performed to verify fluid connectivity between the laser-ablated filling channels and the microwell/nanochannel array.

  15. Crosslinked poly (4-vinylpyridine-ethylene glycol dimethacrylate) used for preconcentration of Cd(II) and its determination by flow injection flame atomic absorption spectrometry.

    PubMed

    Tarley, César Ricardo Teixeira; Farias, Natália Cristina Botteon; Lima, Giovana de Fátima; de Oliveira, Fernanda Midori; Bonfílio, Rudy; Dragunski, Douglas Cardoso; Clausen, Débora Nobile; Segatelli, Mariana Gava

    2014-01-01

    The main purpose of this research was to synthesize crosslinked poly(4-vinylpyridine-ethylene glycol dimethacrylate) and evaluate its feasibility for highly sensitive and selective determination of Cd in water samples by using flow injection flame atomic absorption spectrometry. The crosslinked polymer, prepared by bulk polymerization, was characterized by FTIR spectrometry and scanning electron microscopy. The flow injection solid-phase method was based on preconcentration of 20.0 mL of sample through 100 mg of the polymer packed into a minicolumn at pH 8.25 using a flow rate of 6.0 mL/min, followed by elution with 1.0 M HNO3. The sample solution parameters influencing the preconcentration behavior of Cd ions, such as pH, buffer concentration, and flow rate, were simultaneously studied and optimized using a Doehlert matrix. Values of 0.10 microg/L, 2.0-210 microg/L, 32.3, 18/h, 9.7/min, and 0.62 mL were obtained for LOD, linear range, preconcentration factor, sample throughput, concentration efficiency, and consumption index, respectively. The effect of the presence of the inorganic cations Pb(II), U(IV), Co(II), Hg(II), Cu(II), As(II), Mg(II), Sb(III), Ni(II), Th(IV), Ba(II), and Ca(II) on the method was studied, and the preconcentration of Cd was observed to have no interference. The accuracy of the method was assessed by analysis of natural water samples using addition and recovery tests and inductively coupled plasma/MS as a reference technique, as well as by analysis of a standard reference material of trace elements in water. PMID:24830174

  16. Co-immobilized glucose oxidase and β-galactosidase on bovine serum albumin coated allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymer as a biosensor for lactose determination in milk.

    PubMed

    Jasti, Lakshmi Swarnalatha; Dola, Sandhya Rani; Fadnavis, Nitin W; Addepally, Uma; Daniels, Siona; Ponrathnam, Surendra

    2014-10-01

    Bovine serum albumin (BSA) was adsorbed on allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymer with 25% crosslink density (AGE-25) at pH 8.0 (16% w/w). The amino, thiol and carboxylic acid functional groups available on protein coated surface were utilized for covalent immobilization of glucose oxidase and β-galactosidase, both independently, and in a step-wise manner on the same matrix, with no more than 10% loss of enzyme activity during immobilization. Glutaraldehyde cross-linking after immobilization provided stable enzyme preparations. The pH-optima of the immobilized enzymes were similar to those for free enzyme but their thermal stability was vastly improved. The co-immobilized enzyme support was used as a biosensor for determination of lactose in milk with excellent reproducibility and reusability.

  17. Synthesis of nano-sized stereoselective imprinted polymer by copolymerization of (S)-2-(acrylamido) propanoic acid and ethylene glycol dimethacrylate in the presence of racemic propranolol and copper ion.

    PubMed

    Alizadeh, Taher; Bagherzadeh, Azam; Shamkhali, Amir Nasser

    2016-06-01

    A new chiral functional monomer of (S)-2-(acrylamido) propanoic acid was obtained by reaction of (l)-alanine with acryloyl chloride. The resulting monomer was characterized by FT-IR and HNMR and then utilized for the preparation of chiral imprinted polymer (CIP). This was carried out by copolymerization of (l)-alanine-derived chiral monomer and ethylene glycol dimethacrylate, in the presence of racemic propranolol and copper nitrate, via precipitation polymerization technique, resulting in nano-sized networked polymer particles. The polymer obtained was characterized by scanning electron microscopy and FT-IR. The non-imprinted polymer was also synthesized and used as blank polymer. Density functional theory (DFT) was also employed to optimize the structures of two diasterometric ternary complexes, suspected to be created in the pre-polymerization step, by reaction of optically active isomers of propranolol, copper ion and (S)-2-(acrylamido) propanoic acid. Relative energies and other characteristics of the described complexes, calculated by the DFT, predicted the higher stability of (S)-propranolol involved complex, compared to (R)-propranolol participated complex. Practical batch extraction test which employed CIP as solid phase adsorbent, indicated that the CIP recognized selectively (S)-propranolol in the racemic mixture of propranolol; whereas, the non-imprinted polymer (NIP) showed no differentiation capability between two optically active isomers of propranolol. PMID:27040217

  18. The fabrication of monolithic capillary column based on poly (bisphenol A epoxy vinyl ester resin-co-ethylene glycol dimethacrylate) and its applications for the separation of small molecules in high performance liquid chromatography.

    PubMed

    Niu, Wenjing; Wang, Lijuan; Bai, Ligai; Yang, Gengliang

    2013-07-01

    A new polymeric monolith was synthesized in fused-silica capillary by in situ polymerization technique. In the polymerization, bisphenol A epoxy vinyl ester resin (VER) was used as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the crosslinking monomer, 1,4-butanediol, 1-propanol and water as the co-porogens, and azobisisobutyronitrile (AIBN) as the initiator. The conditions of polymerization have been optimized. Morphology of the prepared poly (VER-co-EDMA) monolith was investigated by the scanning electron microscopy (SEM); pore properties were assayed by mercury porosimetry and nitrogen adsorption. The optimized poly (VER-co-EDMA) monolith showed a uniform structure, good permeability and mechanical stability. Then, the column was used as the stationary phase of high performance liquid chromatography (HPLC) to separate the mixture of benzene derivatives. The best column efficiency achieved for phenol was 235790 theoretical plates per meter. Baseline separations of benzene derivatives and halogenated benzene compounds under optimized isocratic mode conditions were achieved with high column efficiency. The column showed good reproducibility: the relative standard deviation (RSD) values based on the retention times (n=3) for run-to-run, column-to-column and batch-to-batch were less than 0.98, 1.68, 5.48%, respectively. Compared with poly (BMA-co-EDMA) monolithic column, the proposed monolith exhibited more efficiency in the separation of small molecules. PMID:23726080

  19. Immobilization of glucoamylase on polymer surface by radiation-induced polymerization of glass-forming monomers at low temperatures. [Gamma radiation; 2-hydroxyethyl methacrylate; diethylene glycol dimethacrylate

    SciTech Connect

    Yoshida, M.; Kaetsu, I.

    1981-02-01

    Glucoamylase was immobilized in hydrophilic porous poly(2-hydroxyethyl methacrylate) (PHEMA) and hydrophobic microsphere poly(diethylene glycol dimethyacrylate) (PDGDA) by radiation-induced polymerization at low temperatures, in the presence of acetate buffer solution. The distribution on the matrix of immobilized glucoamylase was investigated using fluorescein isothiocyanate (FITC)-conjugated glucoamylase and the fluorescence microscope. It was found that in the porous PHEMA system, the FITC-conjugated glucoamylase is present mainly on the interface between polymer membrane and pore structure and partly in the polymer, while in the microsphere PDGDA system the immobilized glucoamylase is present merely on the surface of the polymer microsphere.

  20. Structure/property relationships in methacrylate/dimethacrylate polymers for dental applications

    NASA Astrophysics Data System (ADS)

    Mehlem, Jeremy John

    Since its invention Bis-GMA or one of its analogs has been the main component of the polymer portion of composites for dental restorations. The need for dilution of Bis-GMA and its analogs to optimize its properties has long been recognized. Bis-GMA is a highly viscous monomer. This high viscosity leads to early vitrification, which limits conversion during cure. This viscosity also limits filler loading. Vitrification at low conversions leads to heterogeneous systems composed of low and high cross-link density phases. The low cross-link density phases behave as defects in the system; therefore, if the amount of low cross-link density phases in the system can be reduced and a more uniform network structure can be achieved, then the mechanical properties of the resin can be improved. Since the increase in viscosity during cure causes vitrification, it is logical that a system with a low initial viscosity will delay the onset of vitrification. Reactive diluents such as triethylene glycol dimethacrylate (TEGDMA) are effective at lower levels. However, large amounts negatively affect matrix properties by increasing polymerization shrinkage and water sorption. Shrinkage has been cited as one of the main deficiencies in dental composites. The goal of this project is to improve upon standard viscosity modifying comonomers such as triethylene glycol dimethacrylate. The comonomers that were explored were phenyloxyethyl methacrylate, cyclohexyl methacrylate, and tert-butylcylcohexyl methacrylate. Multicomponent systems based on analogs of ethylene glycol dimethacrylates with different length ethyl glycol chains were also examined. The substitution of monomethacrylates for TEGDMA as a comonomer resulted in enhanced or negligible affects on the mechanical properties of Bis-MEPP based polymer systems while reducing polymerization shrinkage. 129Xenon NMR and TappingMode(TM) AFM were used to characterize the heterogeneity of dimethacrylates systems during their cure cycle as well

  1. Calcium phosphate nanoparticles functionalized with a dimethacrylate monomer.

    PubMed

    Rodrigues, Marcela Charantola; Hewer, Thiago Lewis Reis; Brito, Giancarlo Espósito de Souza; Arana-Chavez, Victor Elias; Braga, Roberto Ruggiero

    2014-12-01

    The synthesis of calcium phosphate nanoparticles may include modifying agents to tailor particle size, reduce agglomeration and add specific functionalities. This study describes the synthesis of dicalcium phosphate dihydrate (DCPD) nanoparticles functionalized with triethylene glycol dimethacrylate (TEGDMA), added to one of the reacting solutions, with the purpose of reducing agglomeration and improving the compatibility with vinyl-based resin matrices. The nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), elemental analysis, thermogravimetric analysis (TGA), transmission electronic microscopy (TEM), dynamic light scattering (DLS), and surface area (BET). As controls, proprietary DCPD nanoparticles and nanoparticles synthesized without the addition of TEGDMA ("bare") were subjected to the same analytical methods. XRD revealed a similar crystalline structure of the synthesized materials in comparison to the proprietary nanoparticles. The presence of a TEGDMA layer was confirmed by elemental analysis and TGA, corresponding to a mass fraction of 8.5%. FTIR analysis of the functionalized nanoparticles revealed the suppression of some absorbance bands found in the neat TEGDMA. A chemisorption mechanism between TEGDMA and the surface of primary particles by ion-dipole interaction involving TEGDMA oxyethylene, and also an interaction mechanism between the particle surface and terminal-CH3 groups are proposed. Functionalized nanoparticles showed 3 to 11 times higher surface area than the controls, in agreement with DLS data, indicating lower agglomeration.

  2. Ethoxylated Bisphenol Dimethacrylate-based Amorphous Calcium Phosphate Composites

    PubMed Central

    Skrtic, D.; Antonucci, J.M.; Liu, D.W.

    2006-01-01

    Improving the anti-demineralizing/remineralizing and mechanical properties of amorphous calcium phosphate (ACP) composites has been the focus of our recent research. In this study, an ethoxylated bisphenol A dimethacrylate (EBPADMA) was blended with triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA) and methacryloxyethyl phthalate (MEP) to form three experimental resins. The resins were formulated to have 3 different EBPADMA/TEGDMA molar ratios (0.50, 0.85 and 1.35) and a constant HEMA/MEP molar ratio (8.26 ± 0.33). The resins were photo-activated for visible light polymerization and composites were prepared by admixture of either unmilled or milled zirconia-ACP filler (40 % by mass). One aim of the study was to test if improved ion release can be achieved by elevating the EBPADMA/TEGDMA ratio while lowering the level of surface active methacryloxyethyl phthalate in the resin without adversely affecting the strength, degree of vinyl conversion and water sorption of composites. A second aim was to assess the effect of using milled vs. unmilled ACP on these properties of the various composites. Both copolymers blends and composites were assessed for the biaxial flexure strength, degree of vinyl conversion and water sorption, and the composites were evaluated for the mineral ion release as well. Overall ion release of all composites was significantly above the theoretical minimum necessary for remineralization and calcium ion release was not impeded by calcium binding with the carboxylic acid groups of methacryloxyethyl phthalate. Increased supersaturation was attained with increasing EBPADMA/TEGDMA ratio in the resin. Variations in resin composition had no effect on the biaxial flexure strength or degree of vinyl conversion of composites. The biaxial flexure strength values of the milled ACP composites were higher than the biaxial flexure strength values of unmilled ACP composites (56 % and 79 %, respectively for dry and wet specimens

  3. Physical and chemical properties of an antimicrobial Bis-GMA free dental resin with quaternary ammonium dimethacrylate monomer.

    PubMed

    Huang, Qi-ting; He, Jing-wei; Lin, Zheng-mei; Liu, Fang; Lassila, Lippo V J; Vallittu, Pekka K

    2016-03-01

    The objective of this study was to evaluate the antibacterial activity, physicochemical properties of the quaternary ammonium dimethacrylate monomer N,N-bis[2-(3-(methacryloyloxy)propanamido)-ethyl]-N-methylhexadecyl ammonium bromide (IMQ-16) containing diurethane dimethacrylate (UDMA)/tricyclodecane dimethanol diacrylate (SR833s) resin system and compare with bisphenylglycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin system. It was hypothesized that the physical and chemical properties of the experimental polymers would be comparable with Bis-GMA/TEGDMA polymer and IMQ-16 monomer could endow the UDMA/SR833s resin with antibacterial activity. Double bond conversion (DC) was measured using Fourier transform infrared spectroscopy (FTIR). Mechanical properties including flexural strength (FS) and flexural modulus (FM) were measured by three-point bending test with bars of 2mm×2mm×25mm. Water sorption (WS) and solubility (WSL) were also investigated. Antibacterial activity of obtained polymers against Streptococcus mutans Ingbitt (S. mutans) was tested through direct contact test (DCT). The presence of antibacterial activity due to soluble components was also investigated by agar diffusion test (ADT). All of the polymers containing IMQ-16 exhibited improvements in WS and WSL, while maintaining equivalent DC and FS relative to the Bis-GMA/TEGDMA control system. Incorporation of 17% and 20% of IMQ-16 into UDMA/SR833s resin reduced the viable counts of S. mutans after incubation on the surface of the materials and produced no inhibition zones around the cured discs in ADT. UDMA/SR833s resin system is promising to formulate an antibacterial polymer with equivalent or even higher physicochemical properties relative to Bis-GMA/TEGDMA formulation. IMQ-16 is capable to endow UDMA/SR833s resin system with significant antibacterial activity when the mass ratio is 17% or 20%. PMID:26688422

  4. Physical and chemical properties of an antimicrobial Bis-GMA free dental resin with quaternary ammonium dimethacrylate monomer.

    PubMed

    Huang, Qi-ting; He, Jing-wei; Lin, Zheng-mei; Liu, Fang; Lassila, Lippo V J; Vallittu, Pekka K

    2016-03-01

    The objective of this study was to evaluate the antibacterial activity, physicochemical properties of the quaternary ammonium dimethacrylate monomer N,N-bis[2-(3-(methacryloyloxy)propanamido)-ethyl]-N-methylhexadecyl ammonium bromide (IMQ-16) containing diurethane dimethacrylate (UDMA)/tricyclodecane dimethanol diacrylate (SR833s) resin system and compare with bisphenylglycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin system. It was hypothesized that the physical and chemical properties of the experimental polymers would be comparable with Bis-GMA/TEGDMA polymer and IMQ-16 monomer could endow the UDMA/SR833s resin with antibacterial activity. Double bond conversion (DC) was measured using Fourier transform infrared spectroscopy (FTIR). Mechanical properties including flexural strength (FS) and flexural modulus (FM) were measured by three-point bending test with bars of 2mm×2mm×25mm. Water sorption (WS) and solubility (WSL) were also investigated. Antibacterial activity of obtained polymers against Streptococcus mutans Ingbitt (S. mutans) was tested through direct contact test (DCT). The presence of antibacterial activity due to soluble components was also investigated by agar diffusion test (ADT). All of the polymers containing IMQ-16 exhibited improvements in WS and WSL, while maintaining equivalent DC and FS relative to the Bis-GMA/TEGDMA control system. Incorporation of 17% and 20% of IMQ-16 into UDMA/SR833s resin reduced the viable counts of S. mutans after incubation on the surface of the materials and produced no inhibition zones around the cured discs in ADT. UDMA/SR833s resin system is promising to formulate an antibacterial polymer with equivalent or even higher physicochemical properties relative to Bis-GMA/TEGDMA formulation. IMQ-16 is capable to endow UDMA/SR833s resin system with significant antibacterial activity when the mass ratio is 17% or 20%.

  5. Poly(isophthalic acid)(ethylene oxide) as a Macromolecular Modulator for Metal-Organic Polyhedra.

    PubMed

    Chen, Teng-Hao; Wang, Le; Trueblood, Jonathan V; Grassian, Vicki H; Cohen, Seth M

    2016-08-01

    A new strategy was developed by using a polymer ligand, poly(isophthalic acid)(ethylene oxide), to modulate the growth of metal-organic polyhedra (MOP) crystals. This macromolecular modulator can effectively control the crystal habit of several different Cu24L24 (L = isophthalic acid derivatives) MOPs. The polymer also directed the formation of MOP structures under reaction conditions that only produce metal-organic frameworks in the absence of modulator. Moreover, the polymer also enabled the deposition of MOP crystals on glass surfaces. This macromolecular modulator strategy provides an innovative approach to control the morphology and assembly of MOP particles. PMID:27400759

  6. Synthesis and characterization of new dimethacrylate monomer and its application in dental resin.

    PubMed

    He, Jingwei; Liu, Fang; Vallittu, Pekka K; Lassila, Lippo V J

    2013-01-01

    In this study, a dimethacrylate monomer, 1,4-Bis[2-(4-(2'-hydroxy-3'-methacryloyloxy-propoxy)phenyl)-2propyl]benzene (BMPPB) was synthesized to replace 2,2-bis[4-(2'-hydroxyl-3'-methacryloyloxy-propoxy)phenyl]propane (Bis-GMA) as one component of dental restorative materials. The structure of BMPPB and its intermediate product 1,4-bis[2-(4-(oxiranylmethoxy)phenyl)-2propyl]benzene (BOPPB) were confirmed by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance spectroscopy ((1)H-NMR), and elemental analysis. In order to evaluate the possibility of replacing Bis-GMA with BMPPB in dental resin, double bond conversion (DC), polymerization shrinkage, contact angle, water sorption (WS) and solubility (SL), and flexural strength (FS) and modulus of BMPPB/tri(ethylene glycol)dimethacrylate (TEGDMA) (50/50 wt) resin system and Bis-GMA/BMPPB/TEGDMA (25/25/50 wt) resin system were studied. Commercially used Bis-GMA/TEGDMA (50/50 wt) dental resin system was used as reference. The results showed that BMPPB-contained copolymer had higher DC, higher WS and SL than the copolymer that only contained Bis-GMA (p<0.05). All of the copolymers had nearly the same contact angle (p>0.05). BMPPB/TEGDMA resin system had lower polymerization shrinkage, higher FS and modulus (p<0.05) than Bis-GMA/TEGDMA resin system. There was no significant difference on polymerization shrinkage, FS and modulus (p>0.05) between Bis-GMA/BMPPB/TEGDMA resin system and Bis-GMA/TEGDMA resin system. Before and after water immersion, both FS and modulus of every copolymer did not change significantly (p>0.05). Therefore, BMPPB had potential to be used to replace Bis-GMA as base resin in dental restorative materials, but many studies should be undertaken further.

  7. Preparation and characterization of Bis-GMA free dental resin system with synthesized dimethacrylate monomer TDDMMA derived from tricyclo[5.2.1.0(2,6)]-decanedimethanol.

    PubMed

    Yin, Mei; Liu, Fang; He, Jingwei

    2016-04-01

    As a substitute for 2,2-bis[4-(2-hydroxy-3- methacryloxypropoxy)phenyl] propane (Bis-GMA) in dental materials, a new dimethacrylate monomer TDDMMA without bisphenol-A structure was synthesized through the reaction between tricyclo[5.2.1.0(2,6)]- decanedimethanol and 2-isocyanatoethyl methacrylate. The TDDMMA was mixed with triethylene glycol dimethacrylate (TEGDMA) to prepare Bis-GMA free dental resin. Physicochemical properties, such as double bond conversion (DC), polymerization shrinkage (VS), water sorption (WS) and solubility (SL), flexural strength (FS) and modulus (FM) and fracture energy of TDDMMA/TEGDMA resin system were investigated. Bis-GMA/TEGDMA resin system was used as a control. The results showed that, compared with Bis-GMA/TEGDMA resin system, TDDMMA/TEGDMA resin system had comparable VS and several advantages like higher DC, lower SL and better mechanical properties after water immersion. PMID:26717250

  8. Preparation and characterization of Bis-GMA free dental resin system with synthesized dimethacrylate monomer TDDMMA derived from tricyclo[5.2.1.0(2,6)]-decanedimethanol.

    PubMed

    Yin, Mei; Liu, Fang; He, Jingwei

    2016-04-01

    As a substitute for 2,2-bis[4-(2-hydroxy-3- methacryloxypropoxy)phenyl] propane (Bis-GMA) in dental materials, a new dimethacrylate monomer TDDMMA without bisphenol-A structure was synthesized through the reaction between tricyclo[5.2.1.0(2,6)]- decanedimethanol and 2-isocyanatoethyl methacrylate. The TDDMMA was mixed with triethylene glycol dimethacrylate (TEGDMA) to prepare Bis-GMA free dental resin. Physicochemical properties, such as double bond conversion (DC), polymerization shrinkage (VS), water sorption (WS) and solubility (SL), flexural strength (FS) and modulus (FM) and fracture energy of TDDMMA/TEGDMA resin system were investigated. Bis-GMA/TEGDMA resin system was used as a control. The results showed that, compared with Bis-GMA/TEGDMA resin system, TDDMMA/TEGDMA resin system had comparable VS and several advantages like higher DC, lower SL and better mechanical properties after water immersion.

  9. Synthesis of elastic biodegradable polyesters of ethylene glycol and butylene glycol from sebacic acid.

    PubMed

    Park, Hyung-seok; Seo, Jung-a; Lee, Hye-Young; Kim, Hae-Won; Wall, Ivan B; Gong, Myoung-Seon; Knowles, Jonathan C

    2012-08-01

    High molecular weight biodegradable polyesters were prepared from sebacic acid, ethylene glycol and butylene glycol through a simple non-solvent polycondensation with a low toxicity catalyst. The successful synthesis of the polyesters was confirmed by gel permeation chromatography, (1)H-nuclear magnetic resonance and Fourier transform-infrared spectroscopies and differential scanning calorimetry. The degradation tests were performed at 37 °C in phosphate buffer solution (pH 7.4) and showed a mass loss of ~5% over 12 weeks compared with only 2% for polycaprolactone (PCL). Reverse transcription polymerase chain reaction results following culture of osteoblasts on the polymer surface showed that poly(ethylene sebacate) and poly(butylene sebacate) films were optimal for osteoblast formation in terms of Runx 2 and osteocalcin gene expression.

  10. Ethylene glycol

    Integrated Risk Information System (IRIS)

    Ethylene glycol ; CASRN 107 - 21 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  11. Propylene glycol

    Integrated Risk Information System (IRIS)

    Propylene glycol ; CASRN 57 - 55 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  12. Shrinkage, stress, and modulus of dimethacrylate, ormocer, and silorane composites

    PubMed Central

    Bacchi, Atais; Feitosa, Victor Pinheiro; da Silva Fonseca, Andrea Soares Quirino; Cavalcante, Larissa Maria Assad; Silikas, Nikolaos; Schneider, Luis Felipe Jochins

    2015-01-01

    Purpose: to evaluate the shrinkage, polymerization stress, elastic and bulk modulus resulting from composites formulated by siloranes, 2nd generation ormocers, and dimethacrylates. Materials and Methods: The bonded disc method was used to evaluate volumetric shrinkage. The polymerization stress was evaluated by mean of the Bioman. Cylindrical specimens (5 mm thickness and 6 mm diameter) were submitted to gradual loading. Young's and bulk modulus were obtained from the slope of the stress/strain curve. Data were analyzed using one-way analysis of variance and Tukey's test (5%). Results: Grandio and ormocer showed significant higher elastic and bulk modulus. Silorane presented significant lowest bulk modulus and maximum shrinkage. Ormocer and silorane presented lower values for the maximum rate of shrinkage. Extra-low shrinkage (ELS) composite presented the greatest maximum shrinkage. The higher maximum rate of shrinkage was attained by Grandio and ELS, statistically similar from each other. The silorane showed lower values of maximum stress and maximum rate of stress. The higher values of maximum stress were presented by ELS and Grandio, statistical similar between them. Grandio showed the significantly greatest maximum rate of stress. Conclusion: Silorane showed to promote lower shrinkage/stress among the composites, with the lowest elastic modulus. Ormocer showed lower shrinkage/stress than methacrylates despite of its high modulus. PMID:26430302

  13. Tetracalcium phosphate composite containing quaternary ammonium dimethacrylate with antibacterial properties.

    PubMed

    Cheng, Lei; Weir, Michael D; Limkangwalmongkol, Penwadee; Hack, Gary D; Xu, Hockin H K; Chen, Qianming; Zhou, Xuedong

    2012-04-01

    Tooth caries is a carbohydrate-modified bacterial infectious disease, and recurrent caries is a frequent reason for restoration failure. The objective of this study was to develop a novel antibacterial composite using tetracalcium phosphate (TTCP) fillers and bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, which is a quaternary ammonium dimethacrylate (QADM). QADM was synthesized using 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate and incorporated into a resin. The resin was filled with 40% TTCP and 30% glass particles. The following QADM mass fractions in the composite were tested: 0%, 6%, 12%, and 18%. Streptococcus mutans biofilms were formed on the composites and the colony-forming units (CFUs), metabolic activity, and lactic acid production were measured. The TTCP-QADM composite had flexural strength and elastic modulus similar to those of two commercial composites (p > 0.1). Increasing the QADM content in TTCP composite greatly decreased the bacteria growth and biofilm matrix production. There were significantly more dead bacteria with increasing QADM content. TTCP composite containing 18% QADM had biofilm CFU, metabolic activity, and acid production about half of those without QADM. Inversely linear relationships were established between QADM mass fraction and S. mutans biofilm CFU, metabolic activity, and acid production, with correlation coefficients R(2) ≥ 0.98. In conclusion, TTCP-QADM composites were developed and the effect of QADM mass fraction on the antibacterial properties of the composite was determined for the first time. The novel TTCP-QADM composites possessing a strong antibacterial capability, together with calcium phosphate ion release and good mechanical properties, are promising for dental restorations to reduce biofilm growth and recurrent caries.

  14. Tetracalcium phosphate composite containing quaternary ammonium dimethacrylate with antibacterial properties

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Limkangwalmongkol, Penwadee; Hack, Gary D.; Xu, Hockin H. K.; Chen, Qianming; Zhou, Xuedong

    2012-01-01

    Tooth caries is a carbohydrate-modified bacterial infectious disease, and recurrent caries is a frequent reason for restoration failure. The objective of this study was to develop a novel antibacterial composite using tetracalcium phosphate (TTCP) fillers and bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, which is a quaternary ammonium dimethacrylate (QADM). QADM was synthesized using 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate and incorporated into a resin. The resin was filled with 40% TTCP and 30% glass particles. The following QADM mass fractions in the composite were tested: 0%, 6%, 12%, and 18%. Streptococcus mutans biofilms were formed on the composites and the colony-forming units (CFUs), metabolic activity, and lactic acid production were measured. The TTCP-QADM composite had flexural strength and elastic modulus similar to those of two commercial composites (p > 0.1). Increasing the QADM content in TTCP composite greatly decreased the bacteria growth and biofilm matrix production. There were significantly more dead bacteria with increasing QADM content. TTCP composite containing 18% QADM had biofilm CFU, metabolic activity, and acid production about half of those without QADM. Inversely linear relationships were established between QADM mass fraction and S. mutans biofilm CFU, metabolic activity, and acid production, with correlation coefficients R2 ≥ 0.98. In conclusion, TTCP-QADM composites were developed and the effect of QADM mass fraction on the antibacterial properties of the composite was determined for the first time. The novel TTCP-QADM composites possessing a strong antibacterial capability, together with calcium phosphate ion release and good mechanical properties, are promising for dental restorations to reduce biofilm growth and recurrent caries. PMID:22190356

  15. 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. ...

  16. Microgels of polyaspartamide and poly(ethylene glycol) derivatives obtained by γ-irradiation

    NASA Astrophysics Data System (ADS)

    Pitarresi, Giovanna; Licciardi, Mariano; Craparo, Emanuela Fabiola; Calderaro, Elio; Spadaro, Giuseppe; Giammona, Gaetano

    2002-09-01

    The copolymer PHG based on α, β-poly( N-2-hydroxyethyl)- DL-aspartamide (PHEA) functionalized with glycidyl methacrylate has been exposed in aqueous solution to a γ-ray source at different irradiation doses (2, 2.5 and 3.5 kGy), alone or in combination with poly(ethylene glycol)dimethacrylate (PEGDMA) or poly(ethylene glycol)diacrylate (PEGDA). The irradiation produces microgel systems that have been characterized by viscosity measurements. Lyophilization of microgels gives rise to samples able to swell instantaneously in water whereas their treatment with acetone produces swellable microparticles that have been characterized.

  17. Abscisic acid, ethylene and gibberellic acid act at different developmental stages to instruct the adaptation of young leaves to stress

    PubMed Central

    Verelst, Wim; Skirycz, Aleksandra

    2010-01-01

    Drought stress represents a particularly great environmental challenge for plants. A decreased water availability can severely limit growth, and this jeopardizes the organism's primary goal—to survive and sustain growth long enough to ensure the plentiful production of viable seeds within the favorable growth season. It is therefore vital for a growing plant to sense oncoming drought as early as possible, and to respond to it rapidly and appropriately in all organs. A typical, fast energy-saving response is the arrest of growth in young organs, which is likely mediated by root-derived signals. A recent publication indicates that three plant hormones (abscisic acid, ethylene and gibberellic acid) mediate the adaptation of leaf growth in response to drought, and that they act at different developmental stages. Abscisic acid mainly acts in mature cells, while ethylene and gibberellic acid function in expanding and dividing leaf cells. This provides the plant with a means to differentially control the developmental zones of a growing leaf, and to integrate environmental signals differently in sink and source tissues. Here we discuss the biological implications of this discovery in the context of long-distance xylem and phloem transport. PMID:20383070

  18. On the degelation of networks - Case of the radiochemical degradation of methyl methacrylate - ethylene glycol dimethacrylate copolymers

    NASA Astrophysics Data System (ADS)

    Richaud, Emmanuel; Gilormini, Pierre; Verdu, Jacques

    2016-05-01

    Methyl methacrylate networks were synthetized and submitted to radiochemical degradation. Ageing was monitored by means of sol-gel analysis and glass transition temperature measurements. Networks were shown to undergo exclusively chain scission process leading to the degelation of network. The critical conversion degree corresponding to degelation (loss of all elastically active chains) is discussed regarding a statistical theory.

  19. Synthesis of fluorinated dimethacrylate monomer and its application in preparing Bis-GMA free dental resin.

    PubMed

    Yin, Mei; Guo, Sen; Liu, Fang; He, Jingwei

    2015-11-01

    With the aim to reduce human exposure to Bis-phenol A derivatives, a novel fluorinated dimethacrylate monomer FUDMA was synthesized and mixed with triethyleneglycol dimethacrylate (TEGDMA) to prepare 2,2-bis[4-(2-hydroxy-3-methacryloy- loxypropyl)phenyl]propane (Bis-GMA) free dental resin system. Physicochemical properties, such as double bond conversion (DC), polymerization shrinkage (VS), water sorption (WS) and solubility (SL), flexural strength (FS) and modulus (FM), and fracture energy of FUDMA/TEGDMA resin system were investigated. Bis-GMA/TEGDMA resin system was used as a control. The results showed that, compared with Bis-GMA/TEGDMA resin system, FUDMA/TEGDMA had advantages like higher DC, lower VS, and higher fracture energy, but had no disadvantages. Therefore, FUDMA/TEGDMA resin system had better comprehensive physicochemical properties than Bis-GMA/TEGDMA resin system, and FUDMA had potential to be used as a substitute for Bis-GMA. PMID:26282076

  20. Osteoblast response to dimethacrylate composites varying in composition, conversion and roughness using a combinatorial approach

    PubMed Central

    Lin-Gibson, Sheng

    2009-01-01

    Dimethacrylate polymers and composites are seeing increased usage in orthopedics. As these applications require the material to integrate with the surrounding tissues, direct contact cytotoxicity assays should be used to assess the biocompatibility. This study utilized a combinatorial testing platform to evaluate the cell response to dimethacrylate composites with a variety of properties on a single sample. MC3T3-E1 pre-osteoblasts were cultured directly on composites with varying filler content, filler type, degree of conversion (DC), and surface topography. Cell viability, density, and area depended on an interplay of the material properties, with low DC causing a reduction in cell area but having minimal effect on cell viability, high filler content causing an increase in cell density, and filler content/type altering the surface roughness as a function of DC. The combinatorial testing platform successfully quantified the effects of numerous material properties on several aspects of the osteoblast response. PMID:19520423

  1. Synthesis of fluorinated dimethacrylate monomer and its application in preparing Bis-GMA free dental resin.

    PubMed

    Yin, Mei; Guo, Sen; Liu, Fang; He, Jingwei

    2015-11-01

    With the aim to reduce human exposure to Bis-phenol A derivatives, a novel fluorinated dimethacrylate monomer FUDMA was synthesized and mixed with triethyleneglycol dimethacrylate (TEGDMA) to prepare 2,2-bis[4-(2-hydroxy-3-methacryloy- loxypropyl)phenyl]propane (Bis-GMA) free dental resin system. Physicochemical properties, such as double bond conversion (DC), polymerization shrinkage (VS), water sorption (WS) and solubility (SL), flexural strength (FS) and modulus (FM), and fracture energy of FUDMA/TEGDMA resin system were investigated. Bis-GMA/TEGDMA resin system was used as a control. The results showed that, compared with Bis-GMA/TEGDMA resin system, FUDMA/TEGDMA had advantages like higher DC, lower VS, and higher fracture energy, but had no disadvantages. Therefore, FUDMA/TEGDMA resin system had better comprehensive physicochemical properties than Bis-GMA/TEGDMA resin system, and FUDMA had potential to be used as a substitute for Bis-GMA.

  2. Chitosan whiskers from shrimp shells incorporated into dimethacrylate-based dental resin sealant.

    PubMed

    Mahapoka, Ekamon; Arirachakaran, Pratanporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana; Poolthong, Suchit

    2012-01-01

    A resin-based sealant containing chitosan whiskers was developed for use as a pit and fissure sealer. Chitosan whiskers were synthesized and then characterized using Fourier transform infrared spectrometry and transmission electron microscopy. The whiskers were next incorporated into dimethacrylate monomer at various ratios by weight and subsequently analyzed for their antimicrobial and physical properties. The dimethacrylate-based sealant containing chitosan whiskers had a greater antimicrobial activity than control sealant and they were comparable with antimicrobial commercial resin sealants. The inclusion of the whiskers did not reduce the curing depth or degree of double bond conversion and the reduction in hardness was minimal. In conclusion, a resin-based sealant containing chitosan whiskers can be considered an effective antimicrobial pit and fissure sealant.

  3. Degradation resistance of silorane, experimental ormocer and dimethacrylate resin-based dental composites.

    PubMed

    Schneider, Luis Felipe J; Cavalcante, Larissa Maria; Silikas, Nick; Watts, David C

    2011-12-01

    There are several degradation mechanisms of resin-composite restorations and possible deleterious effects created by leached components cannot be ignored. Additionally, the surface integrity influences the long-term clinical performance of resin-composite restorations and can be affected by several factors. Novel technologies have been proposed, but there is a lack of information considering the degradation resistance of such materials. The aim of this study was to investigate the degradation resistance of silorane (SIL), pure-ormocer (ORM) and dimethacrylate (ELS and GRD) resin-based dental composites. Water sorption and solubility tests were adapted from ISO4049, color change trough the CIELab parameters after 24h and 30d immersion in distilled water. Knoop hardness readings were performed at the aforementioned periods and the percentage of hardness decrease was considered. Results were analyzed with one-way ANOVA followed by Tukey's test (P = 0.05). SIL and GRD produced lower water sorption than ORM and ELS. SIL presented the lowest solubility. All materials demonstrated acceptable results for color stability. SIL demonstrated the more stable surface, when considering surface hardness, in aqueous environment. It can be concluded that i) silorane and ormocer-based materials did not produced higher color stability than dimethacrylates in distilled aqueous media; and ii) silorane-based materials exhibited lower water solubility and lower hardness decreases after water immersion than dimethacrylate-based resin-composites, while the pure-ormocer-baed material not.

  4. Thermophysical properties of ethylene glycol mixture based CNT nanofluids

    NASA Astrophysics Data System (ADS)

    Camarano, D. M.; Mansur, F. A.; Araújo, T. L. C. F.; Salles, G. C.; Santos, A. P.

    2016-07-01

    Nanofluids are produced by dispersing nanometer-scale solid particles into base liquids such as water, ethylene glycol, etc. The thermal quadrupole method is utilized to determine the thermophysical properties of materials. By this technique, the thermal diffusivity and conductivity of different nanofluids containing the surfactants humic acid, sodium salt of humic acid and sodium carboxymethyl cellulose and multi-wall carbon nanotubes were evaluated at room temperature and at 75 oC. Values of thermal diffusivity varying in the range from 9.60x10-8 m2s-1 to 1.46x10-7 m2s-1 and thermal conductivity from 0.26 Wm-1K-1 to 41 Wm-1K-1 were obtained. As main conclusions, it was noted that nanofluids exhibit superior heat transfer characteristics than the conventional heat transfer fluid and the thermal conductivity is enhanced by 50% for the nanofluid containing 0.0275 mg/mL of sodium salt of humic acid + ethylene glycol, at the temperature of 25 oC.

  5. In-situ polymerized PLOT columns III: divinylbenzene copolymers and dimethacrylate homopolymers

    NASA Technical Reports Server (NTRS)

    Shen, T. C.; Fong, M. M.

    1994-01-01

    Studies of divinylbenzene copolymers and dimethacrylate homopolymers indicate that the polymer pore size controls the separation of water and ammonia on porous-layer-open-tubular (PLOT) columns. To a lesser degree, the polarity of the polymers also affects the separation of a water-ammonia gas mixture. Our results demonstrate that the pore size can be regulated by controlling the cross-linking density or the chain length between the cross-linking functional groups. An optimum pore size will provide the best separation of water and ammonia.

  6. Crosslinked polymer gel electrolytes based on polyethylene glycol methacrylate and ionic liquid for lithium battery applications

    SciTech Connect

    Liao, Chen; Sun, Xiao-Guang; Dai, Sheng

    2013-01-01

    Gel polymer electrolytes were synthesized by copolymerization polyethylene glycol methyl ether methacrylate with polyethylene glycol dimethacrylate in the presence of a room temperature ionic liquid, methylpropylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPY TFSI). The physical properties of gel polymer electrolytes were characterized by thermal analysis, impedance spectroscopy, and electrochemical tests. The ionic conductivities of the gel polymer electrolytes increased linearly with the amount of MPPY TFSI and were mainly attributed to the increased ion mobility as evidenced by the decreased glass transition temperatures. Li||LiFePO4 cells were assembled using the gel polymer electrolytes containing 80 wt% MPPY TFSI via an in situ polymerization method. A reversible cell capacity of 90 mAh g 1 was maintained under the current density of C/10 at room temperature, which was increased to 130 mAh g 1 by using a thinner membrane and cycling at 50 C.

  7. Cytocompatible Poly(ethylene glycol)-co-polycarbonate Hydrogels Crosslinked by Copper-free, Strain-promoted “Click” Chemistry

    PubMed Central

    Xu, Jianwen; Filion, Tera M.; Prifti, Fioleda

    2013-01-01

    Strategies to encapsulate cells in cytocompatible 3-dimensional hydrogels with tunable mechanical properties and degradability without harmful gelling conditions are highly desired for regenerative medicine applications. Here we reported a method for preparing poly(ethylene glycol)-co-polycarbonate hydrogels through copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) “Click” chemistry. Hydrogels with varying mechanical properties were formed by “clicking” azido-functionalized poly(ethylene glycol)-co-polycarbonate macromers with dibenzocyclooctyne functionalized poly(ethylene glycol) under physiological conditions within minutes. Bone marrow stromal cells encapsulated in these gels exhibited higher cellular viability than those encapsulated in photo-crosslinked poly(ethylene glycol) dimethacrylate. The precise control over the macromer compositions, the cytocompatible SPAAC crosslinking, and the degradability of the polycarbonate segments combined make these hydrogels promising candidates for scaffold- and stem cell-assisted tissue repair and regeneration. PMID:21954076

  8. Reinforcement of SBR/waste rubber powder vulcanizate with in situ generated zinc dimethacrylate

    NASA Astrophysics Data System (ADS)

    Wang, X. P.; Cheng, B. K.; Zhang, X.; Jia, D. M.

    2016-07-01

    Methyl acrylic acid/zinc oxide (MAA/ZnO) was introduced to modify styrene- butadiene rubber/waste rubber powder (SBR/WRP) composites by blending. The enhanced mechanical properties and processing ability were presumably originated from improved compatibility and interfacial interaction between WRP and the SBR matrix by the in situ polymerization of zinc dimethacrylate (ZDMA). A refined interface of the modified SBR/WRP composite was observed by scanning electron microscopy. The formation of ZDMA significantly increased the ionic bond content in the vulcanizate, resulting in exceptional mechanical performance. The comprehensive mechanical properties including tensile strength, tear strength and dynamic heat-building performance reached optimum values with 16 phr MAA.

  9. Colour stability and visual perception of dimethacrylate based dental composite resins.

    PubMed

    Cook, W D; Chong, M P

    1985-07-01

    The spectrophotometric method of colour measurement was applied to an investigation of the colour stability of dimethacrylate based composite resins exposed to thermal and photochemical aging. A good correlation was observed between visual perception of colour change and the spectrophotometric colour difference [delta E (FMC-2)] of unexposed and aged specimens, but 50% of the observers considered the colour match of two specimens to be clinically unacceptable when the colour difference exceeded 10.6. Kinetic studies of thermally and photochemically induced colour change showed a sigmoidal dependence of colour change on the logarithm of exposure time. Because the direction and magnitude of the colour change differed for the two procedures, it would appear that different mechanisms are involved.

  10. Antibacterial amorphous calcium phosphate nanocomposites with a quaternary ammonium dimethacrylate and silver nanoparticles

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Xu, Hockin H. K.; Antonucci, Joseph M.; Kraigsley, Alison M.; Lin, Nancy J.; Lin-Gibson, Sheng; Zhou, Xuedong

    2012-01-01

    Objectives Calcium and phosphate ion-releasing resin composites are promising for remineralization. However, there has been no report on incorporating antibacterial agents to these composites. The objective of this study was to develop antibacterial and mechanically-strong nanocomposites incorporating a quaternary ammonium dimethacrylate (QADM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP). Methods The QADM, bis(2-methacryloyloxyethyl) dimethylammonium bromide (ionic dimethacrylate-1), was synthesized from 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate. Ng was synthesized by dissolving Ag 2-ethylhexanoate salt in 2-(tertbutylamino)ethyl methacrylate. Mechanical properties were measured in three-point flexure with bars of 2×2×25 mm (n = 6). Composite disks (diameter = 9 mm, thickness = 2 mm) were inoculated with Streptococcus mutans. The metabolic activity and lactic acid production of biofilms were measured (n = 6). Two commercial composites were used as controls. Results Flexural strength and elastic modulus of NACP+QADM, NACP+NAg, and NACP+QADM+NAg matched those of commercial composites with no antibacterial property (p > 0.1). The NACP+QADM+NAg composite decreased the titer counts of adherent S. mutans biofilms by an order of magnitude, compared to the commercial composites (p < 0.05). The metabolic activity and lactic acid production of biofilms on NACP+QADM+NAg composite were much less than those on commercial composites (p < 0.05). Combining QADM and NAg rendered the nanocomposite more strongly antibacterial than either agent alone (p < 0.05). Significance QADM and NAg were incorporated into calcium phosphate composite for the first time. NACP+QADM+NAg was strongly-antibacterial and greatly reduced the titer counts, metabolic activity, and acid production of S. mutans biofilms, while possessing mechanical properties similar to commercial composites. These nanocomposites are promising to have

  11. [Chronic ethylene glycol poisoning].

    PubMed

    Kaiser, W; Steinmauer, H G; Biesenbach, G; Janko, O; Zazgornik, J

    1993-04-30

    Over a six-week period a 60-year-old patient had several unexplained intoxication-like episodes. He finally had severe abdominal cramps with changes in the level of consciousness and oligoanuric renal failure (creatinine 4.7 mg/dl). The history, marked metabolic acidosis (pH 7.15, HCO3- 2.2 mmol/l, pCO2 6.6 mmHg) as well as raised anion residue (43 mmol/l) and the presence of oxalates in urine suggested poisoning by ethylene glycol contained in antifreeze liquid. Intensive haemodialysis adequately eliminated ethylene glycol and its toxic metabolites (glycol aldehyde, glycolic acid). Renal function returned within 10 days, although the concentrating power of the kidney remained impaired for several weeks because of interstitial nephritis. The intoxication had been caused by a defective heating-pipe system from which the antifreeze had leaked into the hot-water boiler (the patient had habitually prepared hot drinks by using water from the hot-water tap). Gas chromatography demonstrated an ethylene glycol concentration of 21 g per litre of water.

  12. Diethylene glycol dinitrate (DEGDN)

    Integrated Risk Information System (IRIS)

    Diethylene glycol dinitrate ( DEGDN ) ; CASRN 693 - 21 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments

  13. Triethylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monoethyl ether ; CASRN 112 - 50 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  14. Triethylene glycol monobutyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monobutyl ether ; CASRN 143 - 22 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  15. Propylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Propylene glycol monoethyl ether ; CASRN 52125 - 53 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  16. In vitro comparison of two different materials for the repair of urethan dimethacrylate denture bases

    PubMed Central

    Cilingir, Altug; Bilhan, Hakan; Sulun, Tonguc; Bozdag, Ergun; Sunbuloglu, Emin

    2013-01-01

    PURPOSE The purpose of this in vitro study was to investigate the flexural properties of a recently introduced urethane dimethacrylate denture base material (Eclipse) after being repaired with two different materials. MATERIALS AND METHODS Two repair groups and a control group consisting of 10 specimens each were generated. The ES group was repaired with auto-polymerizing polymer. The EE group was repaired with the Eclipse. The E group was left intact as a control group. A 3-point bending test device which was set to travel at a crosshead speed of 5 mm/min was used. Specimens were loaded until fracture occurred and the mean displacement, maximum load, flexural modulus and flexural strength values and standard deviations were calculated for each group and the data were statistically analyzed. The results were assessed at a significance level of P<.05. RESULTS The mean "displacement", "maximum load before fracture", "flexural strength" and "flexural modulus" rates of Group E were statistically significant higher than those of Groups ES and EE, but no significant difference (P>.05) was found between the mean values of Group ES and EE. There was a statistically significant positive relation (P<.01) between the displacement and maximum load of Group ES (99.5%), Group EE (94.3%) and Group E (84.4%). CONCLUSION The more economic and commonly used self-curing acrylic resin can be recommended as an alternative repair material for Eclipse denture bases. PMID:24353876

  17. The mechanisms of cytotoxicity of urethane dimethacrylate to Chinese hamster ovary cells.

    PubMed

    Chang, Hsiao-Hua; Chang, Mei-Chi; Lin, Li-Deh; Lee, Jang-Jaer; Wang, Tong-Mei; Huang, Chun-Hsun; Yang, Ting-Ting; Lin, Hsueh-Jen; Jeng, Jiiang-Huei

    2010-09-01

    Monomers released from resin-containing products may cause various adverse effects. Urethane dimethacrylate (UDMA) is a principal resin monomer and also a major component released from various dental resin materials. Thus the toxic effects and mechanisms should be elucidated for improving of its safety use. Here we investigated the effects of UDMA on the growth, cell cycle progression, reactive oxygen species (ROS) production and glutathione (GSH) alteration in CHO-K1 cells, and the preventive effects by antioxidants (NAC and catalase) were also evaluated. UDMA elicited growth inhibition (>0.025 mm) of CHO-K1 cells in a clearly dose-dependent manner. Cell cycle perturbation and ROS overproduction were also observed. A 0.1 mm UDMA-induced S-phase cell cycle arrest and ROS accumulation. Cell apoptosis and necrosis became significant when UDMA concentration was 0.25 mm. GSH depletion occurred at cells treated with 0.25 mm UDMA, a highly cytotoxic concentration at which point myriad cells were under apoptosis or necrosis. Thus GSH depletion can be crucial for the death of CHO-K1 cells. Furthermore NAC (0.5-10 mm) and catalase (250-1000 U/ml) obviously attenuated the UDMA-induced toxicity by reducing ROS generation and cell cycle disturbance, and the effects were dose-related. These results suggest that UDMA toxicity is associated with ROS production, GSH depletion, cell cycle disturbance and cell apoptosis/necrosis. PMID:20579731

  18. Analysis of the biocompatibility of perfluoropolyether dimethacrylate network using an organotypic method.

    PubMed

    Jellali, Rachid; Duval, Jean-Luc; Leclerc, Eric

    2016-08-01

    In this work, we have investigated the potential of perfluoropolyether (PFPE) polymers for use in biomaterial applications, especially in cell culture and tissue engineering. PFPE substrates were synthesized by the photocuring of liquid PFPE urethane dimethacrylate. These surfaces were then modified by ECM protein coatings and microstructuration, to promote cell adhesion and migration. The surface properties of PFPE and PDMS (used as a reference) samples were studied by static contact angle measurements and AFM imaging. Both polymer surfaces were hydrophobic, having sessile air-water contact angles superior to 100°. Collagen and fibronectin coatings were found to change the wettability of PFPE and PDMS samples. The biological testing of substrates was done using a liver organotypic culture to evaluate the migration and density of liver cells. The results over seven days of culture demonstrated that the migration and density of cells cultured under untreated PFPE were higher than the migration and density of cells cultured under PDMS. ECM protein coatings enhanced cell migration from liver explants cultured on PFPE or PDMS. Furthermore, these coatings were more efficient in the case of a PFPE sample. From a second series of tests, in which the PFPE was microstructured, it was found that microstructures promoted the formation of a 3D cell layer. These results indicate that PFPE polymers have a potential for use in the development of biomaterials for tissue engineering and cell culture. PMID:27157755

  19. Polyethylene Glycol Propionaldehydes

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  20. Stereolithography of three-dimensional bioactive poly(ethylene glycol) constructs with encapsulated cells.

    PubMed

    Arcaute, Karina; Mann, Brenda K; Wicker, Ryan B

    2006-09-01

    Stereolithography (SL) was used to fabricate complex 3-D poly(ethylene glycol) (PEG) hydrogels. Photopolymerization experiments were performed to characterize the solutions for use in SL, where the crosslinked depth (or hydrogel thickness) was measured at different laser energies and photoinitiator (PI) concentrations for two concentrations of PEG-dimethacrylate in solution (20% and 30% (w/v)). Hydrogel thickness was a strong function of PEG concentration, PI type and concentration, and energy dosage, and these results were utilized to successfully fabricate complex hydrogel structures using SL, including structures with internal channels of various orientations and multi-material structures. Additionally, human dermal fibroblasts were encapsulated in bioactive PEG photocrosslinked in SL. Cell viability was at least 87% at 2 and 24 h following fabrication. The results presented here indicate that the use of SL and photocrosslinkable biomaterials, such as photocrosslinkable PEG, appears feasible for fabricating complex bioactive scaffolds with living cells for a variety of important tissue engineering applications.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  2. Interstellar Antifreeze: Ethylene Glycol

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-01-01

    Interstellar ethylene glycol (HOCH2CH2,OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/ reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  3. Cytotoxicity of urethane dimethacrylate composites before and after aging and leaching.

    PubMed

    Mohsen, N M; Craig, R G; Hanks, C T

    1998-02-01

    The in vitro cytotoxicity of urethane dimethacrylate composites cured at different times by visible light and after different aging times and extraction treatments was evaluated using succinic dehydrogenase activity in the mitochondria of a fibroblastic cell line to reflect cell viability. In addition, extractable chemicals associated with cell response were identified. The composite samples were tested untreated, polished, or extracted with water or 75% ethanol-water. Balb/c 3T3 fibroblasts were used as the cell culture system while MTT-formazan production was used as the toxicity parameter. Cell viability was calculated as a percentage of Teflon controls. Identification of the chemicals was measured by extracting the composites with 75% ethanol-water, separating the extract by HPLC, and identifying the fractions with mass spectroscopy. In general, cell viability increased continuously with curing time for differently treated samples at high aging times (288 h) while it decreased when the composites were not aged (0 h). In addition, for 75% ethanol or water-extracted composites, cell viability increased within the first 24 h of aging and reached a plateau after 72 h. Lowest cytotoxicity occurred when the samples were extracted with the 75% ethanol solution. The highest cytotoxic effects were found when the samples were untreated. Slightly reduced cytotoxic effects were seen with polished composites. The results suggest that curing the light-activated composites for a minimum of 150 s and post-curing for 24 h is required to attain comparable biocompatibility with the Teflon control. Removing the oxygen-inhibited layer from these composites decreased the cytotoxicity by 33% while extracting the composites with 75% ethanol-water decreased it by 77%. Chemicals released from the surface accounted for approximately 40% of cellular response while about 60% of the response was due to chemical components released from the bulk. The primary leachable component from the

  4. Development of erbium phosphate doped poly(glycidyl methacrylate/ethylene dimethacrylate) spin columns for selective enrichment of phosphopeptides.

    PubMed

    Güzel, Yüksel; Rainer, Matthias; Messner, Christoph B; Hussain, Shah; Meischl, Florian; Sasse, Michael; Tessadri, Richard; Bonn, Günther K

    2015-05-01

    In this study, a novel method for the highly selective enrichment of phosphopeptides using erbium phosphate doped poly(glycidyl methacrylate/ethylene dimethacrylate) spin columns is presented. Erbium phosphate was synthesized by precipitation from boiling phosphoric acid and incubated overnight in erbium chloride solutions. The resulting powder was embedded in a monolithic poly(glycidyl methacrylate/ethylene dimethacrylate) polymer. The monolith was synthesized in a spin column by radical polymerization. Erbium phosphate demonstrated a high affinity and selectivity for phosphopeptides due to the strong interaction of trivalent erbium ions with the phosphate groups of phosphopeptides. The high selectivity and performance of the designed spin columns were demonstrated by successfully enriching phosphopeptides from tryptically digested protein mixtures containing the model phosphoproteins α- and β-casein, bovine milk, and human saliva. By the implementation of several washing steps, unspecific components were removed and the enriched phosphopeptides were effectively eluted from the spin columns under alkaline conditions. The selective performance of the presented method was further demonstrated by the enrichment of two synthetic phosphopeptides, which were spiked in tryptically digested and dephosphorylated HeLa cell lysates at low ratios. Finally, the presented approach was compared to conventional phosphopeptide enrichment by titanium oxide and revealed higher recoveries for the erbium phosphate doped monoliths.

  5. Spectral spatial electron paramagnetic resonance imaging as a tool to study photoactive dimethacrylate-based dental resins

    NASA Astrophysics Data System (ADS)

    Levêque, Philippe; Leprince, Julian G.; Bebelman, Sabine; Devaux, Jacques; Leloup, Gaëtane; Gallez, Bernard

    2012-07-01

    Photopolymerizable dimethacrylate-based dental resins, which are widely used in the current routine dental practice, show a very strong EPR signal. This signal has already been studied by EPR spectroscopy, but not by EPR imaging. The spectrum is quite complex due to hyperfine splitting and to the presence of two radical species, which is a priori not favorable to EPR imaging. In this work, the robustness of EPR imaging was investigated, both in the spatial and spectral-spatial modes, to characterize this type of material using small resin samples. The images produced using standard deconvolution and filtered backprojection procedure did not display any noticeable artifact. They also reflected the expected density of free radicals in two types of resin, photopolymerized with two different light irradiances. Moreover, the spectral-spatial imaging mode provided a complete spectrum for each pixel, which enabled to delineate the different distributions of the two radical species inside the samples. EPR imaging offered a different information compared to the usual degree of conversion measured by Raman spectrometry. These results suggest that EPR imaging could be used as a complementary tool to further characterize the dimethacrylate-based resins used in dental practice or for other applications.

  6. [Crystalluria in ethylene glycol intoxication].

    PubMed

    Montagnac, Richard; Thouvenin, Maxime; Luxey, Grégoire; Schendel, Adeline; Parent, Xavier

    2014-11-01

    When seen, some habits of calcium oxalate monohydrate crystals (whewellite) are so typical of ethylene glycol intoxication that they may be helpful for its diagnosis when circumstances are not clearly established.

  7. Polyethylene glycol coated CoFe{sub 2}O{sub 4} nanoparticles: A potential spinel ferrite for biomedical applications

    SciTech Connect

    Humbe, Ashok V.; Birajdar, Shankar D.; Jadhav, K. M.; Bhandari, J. M.; Waghule, N. N.; Bhagwat, V. R.

    2015-06-24

    The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe{sub 2}O{sub 4}) nanoparticles have been reported in the present study. CoFe{sub 2}O{sub 4} nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe{sub 2}O{sub 4} nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe{sub 2}O{sub 4} nanoparticles were calculated by using XRD data. The presence of PEG on CoFe{sub 2}O{sub 4} nanoparticles and reduced agglomeration in the CoFe{sub 2}O{sub 4} nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, coercivity etc have been obtained. These magnetic parameters were get decreased by PEG coating.

  8. Polyethylene glycol coated CoFe2O4 nanoparticles: A potential spinel ferrite for biomedical applications

    NASA Astrophysics Data System (ADS)

    Humbe, Ashok V.; Birajdar, Shankar D.; Bhandari, J. M.; Waghule, N. N.; Bhagwat, V. R.; Jadhav, K. M.

    2015-06-01

    The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe2O4) nanoparticles have been reported in the present study. CoFe2O4 nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe2O4 nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe2O4 nanoparticles were calculated by using XRD data. The presence of PEG on CoFe2O4 nanoparticles and reduced agglomeration in the CoFe2O4 nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, coercivity etc have been obtained. These magnetic parameters were get decreased by PEG coating.

  9. Degree of conversion and leached monomers of urethane dimethacrylate-hydroxypropyl methacrylate-based dental resin systems.

    PubMed

    Zhang, Meng; Puska, Mervi A; Botelho, Michael G; Säilynoja, Eija S; Matinlinna, Jukka P

    2016-01-01

    The degree of conversion (DC) and monomer leaching of three experimental urethane dimethacrylate (UEDMA)-hydroxypropyl methacrylate (HPMA)-based resin systems were studied. Three experimental resins (E1: 70.6 wt% UEDMA + 27.4 wt% HPMA, E2: 80.6 wt% UEDMA + 17.4 wt% HPMA, E3: 90.6 wt% UEDMA + 7.4 wt% HPMA) and one control resin [C: 70.6 wt% bis-phenol A glycidyl methacrylate (bis-GMA) + 27.4 wt% methyl methacrylate (MMA)] were prepared. For the DC test, cylindrical specimens [1.5 mm (h) × 6 mm (d)] were scanned with an ATR-FTIR instrument before and after light-curing (n = 5). For the monomer leaching test, block-shaped specimens [5.67 mm (l) × 2.00 mm (w) × 2.00 mm (h)] were light-cured (n = 6), stored in a 75% ethanol:water solution for 3 days, and then analyzed with HPLC. The UEDMA-HPMA-based experimental groups showed higher DC (62-78%) than the bis-GMA-MMA-based control group (58-66%), and the DC decreased as the UEDMA content increased (P < 0.05). Amongst the four groups, E3 exhibited the lowest leaching of both mono methacrylate (0.1% HPMA) and dimethacrylate (<0.043% UEDMA) monomers after 30 or 40 s of curing. The UEDMA-HPMA-based resins, therefore, exhibited higher DC and less monomer leaching compared to the bis-GMA-MMA-based resin. (J Oral Sci 58, 15-22, 2016). PMID:27021535

  10. Degree of conversion and leached monomers of urethane dimethacrylate-hydroxypropyl methacrylate-based dental resin systems.

    PubMed

    Zhang, Meng; Puska, Mervi A; Botelho, Michael G; Säilynoja, Eija S; Matinlinna, Jukka P

    2016-01-01

    The degree of conversion (DC) and monomer leaching of three experimental urethane dimethacrylate (UEDMA)-hydroxypropyl methacrylate (HPMA)-based resin systems were studied. Three experimental resins (E1: 70.6 wt% UEDMA + 27.4 wt% HPMA, E2: 80.6 wt% UEDMA + 17.4 wt% HPMA, E3: 90.6 wt% UEDMA + 7.4 wt% HPMA) and one control resin [C: 70.6 wt% bis-phenol A glycidyl methacrylate (bis-GMA) + 27.4 wt% methyl methacrylate (MMA)] were prepared. For the DC test, cylindrical specimens [1.5 mm (h) × 6 mm (d)] were scanned with an ATR-FTIR instrument before and after light-curing (n = 5). For the monomer leaching test, block-shaped specimens [5.67 mm (l) × 2.00 mm (w) × 2.00 mm (h)] were light-cured (n = 6), stored in a 75% ethanol:water solution for 3 days, and then analyzed with HPLC. The UEDMA-HPMA-based experimental groups showed higher DC (62-78%) than the bis-GMA-MMA-based control group (58-66%), and the DC decreased as the UEDMA content increased (P < 0.05). Amongst the four groups, E3 exhibited the lowest leaching of both mono methacrylate (0.1% HPMA) and dimethacrylate (<0.043% UEDMA) monomers after 30 or 40 s of curing. The UEDMA-HPMA-based resins, therefore, exhibited higher DC and less monomer leaching compared to the bis-GMA-MMA-based resin. (J Oral Sci 58, 15-22, 2016).

  11. Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms

    PubMed Central

    Nalawade, Triveni Mohan; Bhat, Kishore; Sogi, Suma H. P.

    2015-01-01

    Aim: The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Materials and Methods: Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. Results: All vehicles

  12. 21 CFR 582.1666 - Propylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Additives § 582.1666 Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally recognized as safe (except in cat food) when used in accordance with good...

  13. Colorometric detection of ethylene glycol vapor

    NASA Technical Reports Server (NTRS)

    Helm, C.; Mosier, B.; Verostko, C. E.

    1970-01-01

    Very low concentrations of ethylene glycol in air or other gases are detected by passing a sample through a glass tube with three partitioned compartments containing reagents which successively convert the ethylene glycol vapor into a colored compound.

  14. Propylene glycol monomethyl ether (PGME)

    Integrated Risk Information System (IRIS)

    Propylene glycol monomethyl ether ( PGME ) ; CASRN 107 - 98 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

  15. GLYCOLIC - FORMIC ACID FLOWSHEET DEVELOPMENT

    SciTech Connect

    Pickenheim, B.; Stone, M.; Newell, J.

    2010-11-08

    Flowsheet testing was performed to further develop the nitric/glycolic/formic acid flowsheet as an alternative to the nitric/formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be removed in the Sludge Receipt and Adjustment Tank (SRAT) with minimal hydrogen generation. All other processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Eight runs were performed in total, including the baseline run. The baseline nitric/formic flowsheet run was extremely difficult to process under existing DWPF acceptance criteria with this simulant at the HM levels of noble metals. While nitrite was destroyed and mercury was removed to near the DWPF limit, the rheology of the SRAT and SME products were well above design basis and hydrogen generation far exceeded the DWPF limit. In addition, mixing during the SME cycle was very poor. In this sense, the nitric/glycolic/formic acid flowsheet represents a significant upgrade over the current flowsheet. In the nitric/glycolic/formic flowsheet runs, mercury was successfully removed with almost no hydrogen generation and the SRAT and SME products yield stresses were within process limits or previously processed ranges. It is recommended that DWPF continue to support development of the nitric/glycolic/formic flowsheet. Although experience is limited at this time, this flowsheet meets or outperforms the current flowsheet in many regards, including off-gas generation, mercury removal, product rheology and general ease of processing. Additional flowsheet testing will allow for a more thorough understanding of the chemistry and effectiveness of the flowsheet over a range of sludge compositions and formic/glycolic ratios. This testing will also show whether the REDOX and metal solubility concerns with this change in the flowsheet can be addressed by just adjusting the volumes of

  16. Glycolate transporter of the pea chloroplast envelope

    SciTech Connect

    Howitz, K.T.

    1985-01-01

    The discovery of a glycolate transporter in the pea (Pisum sativum) chloroplast envelope is described. Several novel silicone oil centrifugation methods were developed to resolve the initial rate kinetics of (/sup 14/C)glycolate transport by isolated, intact pea chloroplasts. Chloroplast glycolate transport was found to be carrier mediated. Transport rates saturated with increasing glycolate concentration. N-Ethylmaleimide (NEM) pretreatment of chloroplasts inhibited transport, an inhibition prevented by glycolate. Glycolate distributed across the envelope in a way which equalized stromal and medium glycolic acid concentrations, limiting possible transport mechanisms to facilitated glycolic acid diffusion, proton symport or hydroxyl antiport. The effects of stomal and medium pH's on the K/sub m/ and V/sub max/ fit the predictions of mobile carrier kinetic models of hydroxyl antiport or proton symport (H/sup +/ binds first). The carrier mediated transport was fast enough to be consistent with in vivo rates of photorespiration. The 2-hydroxymonocarboxylates, glycerate, lactate and glyoxylate are competitive inhibitors of chloroplast glycolate uptake. Glyoxylate, D-lactate and D-glycerate cause glycolate counterflow, indicating that they are also substrates of the glycolate carrier. This finding was confirmed for D-glycerate by studies on glycolate effects on (1-/sup 14/C)D-glycerate transport.

  17. Selection of di(meth)acrylate monomers for low pollution of fluorinated mold surfaces in ultraviolet nanoimprint lithography.

    PubMed

    Nakagawa, Masaru; Kobayashi, Kei; Hattori, Azusa N; Ito, Shunya; Hiroshiba, Nobuya; Kubo, Shoichi; Tanaka, Hidekazu

    2015-04-14

    We used fluorescence microscopy to show that low adsorption of resin components by a mold surface was necessary for continuous ultraviolet (UV) nanoimprinting, as well as generation of a low release energy on detachment of a cured resin from a template mold. This is because with low mold pollution, fracture on demolding occurred at the interface between the mold and cured resin surfaces rather than at the outermost part of the cured resin. To achieve low mold pollution, we investigated the radical photopolymerization behaviors of fluorescent UV-curable resins and the mechanical properties (fracture toughness, surface hardness, and release energy) of the cured resin films for six types of di(meth)acrylate-based monomers with similar chemical structures, in which polar hydroxy and aromatic bulky bisphenol moieties and methacryloyl or acryloyl reactive groups were present or absent. As a result, we selected bisphenol A glycerolate dimethacrylate (BPAGDM), which contains hydroxy, bisphenol, and methacryloyl moieties, which give good mechanical properties, monomer bulkiness, and mild reactivity, respectively, as a suitable base monomer for UV nanoimprinting under an easily condensable alternative chlorofluorocarbon (HFC-245fa) atmosphere. The fluorescent UV-curable BPAGDM resin was used for UV nanoimprinting and lithographic reactive ion etching of a silicon surface with 32 nm line-and-space patterns without a hard metal layer. PMID:25793911

  18. Stability and repeatability of capillary columns based on porous monoliths of poly(butyl methacrylate-co-ethylene dimethacrylate)

    PubMed Central

    Geiser, Laurent; Eeltink, Sebastiaan; Svec, Frantisek; Fréchet, Jean M.J.

    2009-01-01

    Monolithic poly(butyl methacrylate-co-ethylene dimethacrylate) capillary columns have been prepared via either thermally or photochemically initiated polymerization of the corresponding monomers and the repeatability of their preparation has been explored. Three separate batches of five columns each were prepared using thermal and photochemical initiation for a total of thirty columns. All thirty capillary columns were tested in liquid chromatography-electrospray ionization-mass spectrometry mode for the separation of a model mixture of three proteins - ribonuclease A, cytochrome c and myoglobin. Excellent repeatability of retention times was observed for the proteins as evidenced by relative standard deviation (RSD) values of less than 1.5%. Somewhat broader variations with RSD values of up to 10% were observed for the pressure drop in the columns. The stability of retention times was also monitored using a single monolithic column and no significant shifts in either retention times or back pressure was observed in a series of almost 2200 consecutive protein separations. PMID:17182044

  19. Urethane dimethacrylate induces cytotoxicity and regulates cyclooxygenase-2, hemeoxygenase and carboxylesterase expression in human dental pulp cells.

    PubMed

    Chang, Hsiao-Hua; Chang, Mei-Chi; Wang, Hsin-Hui; Huang, Guay-Fen; Lee, Yuan-Ling; Wang, Yin-Lin; Chan, Chiu-Po; Yeung, Sin-Yuet; Tseng, Shuei-Kuen; Jeng, Jiiang-Huei

    2014-02-01

    The toxic effect of urethane dimethacrylate (UDMA), a major dental resin monomer, on human dental pulp is not fully clear. In this study, we investigated the influence of UDMA on the cytotoxicity, cell cycle distribution, apoptosis and related gene expression of dental pulp cells. The role of reactive oxygen species, hemeoxygenase-1 (HO-1) and carboxylesterase (CES) in UDMA cytotoxicity, was evaluated. UDMA induced morphological changes of pulp cells and decreased cell viability by 29-49% at concentrations of 0.1-0.35 mM. UDMA induced G0/G1, G2/M cell cycle arrest and apoptosis. The expression of cdc2, cyclinB1 and cdc25C was inhibited by UDMA. Moreover, UDMA stimulated COX-2, HO-1 and CES2 mRNA expression of pulp cells. The cytotoxicity of UDMA was attenuated by N-acetyl-l-cysteine, catalase and esterase, but was enhanced by Zn-protoporphyrin (HO-1 inhibitor), BNPP (CES inhibitor) and loperamide (CES2 inhibitor). Exposure of UDMA may potentially induce the inflammation and toxicity of dental pulp. These findings are important for understanding the clinical response of human pulp to resin monomers after operative restoration and pulp capping, and also provide clues for improvement of dental materials. PMID:24140606

  20. Synthesis of a novel tertiary amine containing urethane dimethacrylate monomer (UDMTA) and its application in dental resin.

    PubMed

    Liu, Dongliang; Liu, Fang; He, Jingwei; Lassila, Lippo V J; Vallittu, Pekka K

    2013-06-01

    A novel tertiary amine containing urethane dimethacrylate monomer UDMTA was synthesized with the aim of replacing Bis-GMA as one component of dental restorative materials. The structure of UDMTA was confirmed by FT-IR and (1)H-NMR spectra. UDMTA was incorporated into Bis-GMA/TEGDMA (50 wt%/50 wt%) resin system to replace Bis-GMA partly and totally. Double bond conversion, polymerization volumetric shrinkage, water sorption and solubility, flexural strength and modulus of UDMTA containing resin formulations were studied with neat Bis-GMA/TEGDMA resin formulation as a reference. Results showed that UDMTA could be used as a coinitiator in photocurable dental resin, UDMTA containing resin had higher double bond conversion and lower polymerization shrinkage than that of Bis-GMA/TEGDMA resin, and the UDMTA containing copolymer had higher flexural strength and flexural modulus than Bis-GMA/TEGDMA copolymer. When UDMTA was used to replace more than 25 wt% of Bis-GMA, the obtained copolymer had higher water sorption and solubility. The optimized resin composition is by replacing 25 wt% of Bis-GMA in Bis-GMA/TEGDMA (50/50 by wt%), for the prepared resin had the best comprehensive properties.

  1. Propylene Glycol Poisoning From Excess Whiskey Ingestion

    PubMed Central

    Ku, Kevin; Sue, Gloria R.

    2015-01-01

    In this report, we describe a case of high anion gap metabolic acidosis with a significant osmolal gap attributed to the ingestion of liquor containing propylene glycol. Recently, several reports have characterized severe lactic acidosis occurring in the setting of iatrogenic unintentional overdosing of medications that use propylene glycol as a diluent, including lorazepam and diazepam. To date, no studies have explored potential effects of excess propylene glycol in the setting of alcohol intoxication. Our patient endorsed drinking large volumes of cinnamon flavored whiskey, which was likely Fireball Cinnamon Whisky. To our knowledge, this is the first case of propylene glycol toxicity from an intentional ingestion of liquor containing propylene glycol. PMID:26904700

  2. Final report on the safety assessment of PEG-25 propylene glycol stearate, PEG-75 propylene glycol stearate, PEG-120 propylene glycol stearate, PEG-10 propylene glycol, PEG-8 propylene glycol cocoate, and PEG-55 propylene glycol oleate.

    PubMed

    Johnson, W

    2001-01-01

    The ingredients considered in this safety assessment are polyethylene glycol ethers of either propylene glycol itself, propylene glycol stearate, propylene glycol oleate, or propylene glycol cocoate. They function in cosmetic formulations as surfactant--cleansing agents; surfactant-solubilizing agents; surfactant--emulsifying agents; skin conditioning agents--humectant; skin-conditioning agents--emollient; and solvents. Those in current use are used in only a small number of cosmetic formulations. Some are not currently used. Polyethylene Glycol (PEG) Propylene Glycol Cocoates and PEG Propylene Glycol Oleates are produced by the esterification of polyoxyalkyl alcohols with lauric acid and oleic acid, respectively. Although there is no information available on the method of manufacture of the other polymers, information was available describing impurities, including ethylene oxide (maximum 1 ppm), 1,4-dioxane (maximum 5 ppm), polycyclic aromatic compounds (maximum 1 ppm), and heavy metals-lead, iron, cobalt, nickel, cadmium, and arsenic included (maximum 10 ppm combined). In an acute oral toxicity study, PEG-25 Propylene Glycol Stearate was not toxic. An antiperspirant product containing 2.0% PEG-25 Propylene Glycol Stearate was nonirritating to mildly irritating to the eyes of rabbits. This product was also practically nonirritating to the skin of rabbits in single-insult occlusive patch tests. In a guinea pig sensitization test, PEG-25 Propylene Glycol Stearate was classified as nonallergenic at challenge concentrations of 25% and 50% in petrolatum. PEG-25 Propylene Glycol Stearate and PEG-55 Propylene Glycol Oleate were negative in clinical patch tests. Based on the available data, it was concluded that these ingredients are safe as used (concentrations no greater than 10%) in cosmetic formulations. Based on evidence of sensitization and nephrotoxicity in burn patients treated with a PEG-based antimicrobial preparation, the ingredients included in this review

  3. Poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith coupled to high-performance liquid chromatography for the determination of adenosine phosphates in royal jelly.

    PubMed

    Liu, Dan; Zhang, Tianbin; Cheng, Yechun; Jia, Qiong

    2014-07-01

    A polymer monolith microextraction method coupled with high-performance liquid chromatography was developed for the determination of adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate. The monolithic column was synthesized inside fused-silica capillaries using thermal initiation free-radical polymerization with glycidyl methacrylate as the monomer, ethylene dimethacrylate as the cross-linker, cyclohexanol, and 1-dodecanol as the porogen. N-Methylolacrylamide, an important hydrophilic monomer, was incorporated into the polymerization mixture to enhance the hydrophilicity of the poly(glycidyl methacrylate-co-ethylene dimethacrylate) column. The obtained poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectra, and X-ray photoelectron spectroscopy. Optimum conditions for the preconcentration and separation of the target adenosines were also investigated. Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good relative standard deviations. The developed polymer monolith microextraction with high-performance liquid chromatography method exhibited a good performance with recovery values in the range of 76.9-104.7% when applied to the determination of the adenosines in five royal jelly samples.

  4. Cutaneous metabolism of glycol ethers.

    PubMed

    Lockley, David J; Howes, Douglas; Williams, Faith M

    2005-03-01

    The toxicity of glycol ethers is associated with their oxidation to the corresponding aldehyde and alkoxyacetic acid by cytosolic alcohol dehydrogenase (ADH; EC 1.1.1.1.) and aldehyde dehydrogenase (ALDH; 1.2.1.3). Dermal exposure to these compounds can result in localised or systemic toxicity including skin sensitisation and irritancy, reproductive, developmental and haemotological effects. It has previously been shown that skin has the capacity for local metabolism of applied chemicals. Therefore, there is a requirement to consider metabolism during dermal absorption of these compounds in risk assessment for humans. Cytosolic fractions were prepared from rat liver, and whole and dermatomed skin by differential centrifugation. Rat skin cytosolic fractions were also prepared following multiple dermal exposure to dexamethasone, ethanol or 2-butoxyethanol (2-BE). The rate of ethanol, 2-ethoxyethanol (2-EE), ethylene glycol, 2-phenoxyethanol (2-PE) and 2-BE conversion to alkoxyacetic acid by ADH/ALDH in these fractions was continuously monitored by UV spectrophotometry via the conversion of NAD+ to NADH at 340 nm. Rates of ADH oxidation by rat liver cytosol were greatest for ethanol followed by 2-EE >ethylene glycol >2-PE >2-BE. However, the order of metabolism changed to 2-BE >2-PE >ethylene glycol >2-EE >ethanol using whole and dermatomed rat skin cytosolic fractions, with approximately twice the specific activity in dermatomed skin cytosol relative to whole rat skin. This suggests that ADH and ALDH are localised in the epidermis that constitutes more of the protein in dermatomed skin than whole skin cytosol. Inhibition of ADH oxidation in rat liver cytosol by pyrazole was greatest for ethanol followed by 2-EE >ethylene glycol >2-PE >2-BE, but it only inhibited ethanol metabolism by 40% in skin cytosol. Disulfiram completely inhibited alcohol and glycol ether metabolism in the liver and skin cytosolic fractions. Although ADH1, ADH2 and ADH3 are expressed at the

  5. Measuring exposures to glycol ethers.

    PubMed Central

    Clapp, D E; Zaebst, D D; Herrick, R F

    1984-01-01

    In 1981, NIOSH began investigating the potential reproductive health effects resulting from exposures to a class of organic solvents known generically as glycol ethers (GE). This research was begun as a result of the NIOSH criteria document development program which revealed little data available on the health effects of glycol ether exposure. Toxicologic research was begun by NIOSH and other researchers which suggested substantial reproductive effects in animals. These animal data motivated a study of human exposures in the occupational setting. In 1981 and 1982 NIOSH conducted several walk-through surveys which included preliminary measurements of exposures in a variety of industries including painting trades, coal mining, production blending and distribution facilities, aircraft fueling, and communications equipment repair facilities. The human exposure data from these surveys is summarized in this paper with most results well below 1 parts per million (ppm) and only a few values approaching 10 ppm. Blood samples were collected at one site resulting in GE concentrations below the limit of detection. Exposures to airborne glycol ethers, in the industries investigated during the collection of this data, revealed several problems in reliably sampling GE at low concentrations. It became apparent, from the data and observations of work practices, that air monitoring alone provided an inadequate index of GE exposure. Further field studies of exposure to GE are anticipated, pending location of additional groups of exposed workers and development of more reliable methods for characterizing exposure, especially biological monitoring. PMID:6499824

  6. Why use glycols in HVAC systems?

    SciTech Connect

    Eppelheimer, D.M.

    1997-12-31

    Glycols are used to prevent damage to heating, ventilating, and airconditioning (HVAC) equipment due to freezing and corrosion. Two glycols enjoy wide acceptance--ethylene glycol and propylene glycol. Both glycols have lower heat transfer characteristics and increased pumping requirements when compared to water. The loss of heat transfer and the increase in pumping power are influenced by temperature and the concentration of the fluid. The physical effects of glycol are almost unnoticed in heating systems where higher temperatures prevail. However, in cooling applications, the effect of glycol on system capacity and pump power must be carefully considered. Capricious addition of glycol to cooling systems is inappropriate. The effects of glycol can be mitigated by careful selection of equipment. This paper illustrates methods by which to reduce the impact of glycols when selecting cooling coils and chillers. Techniques such as increasing log mean temperature difference (LMTD) and modifications in coil circuiting or tube geometry can have a dramatic effect. The benefits of these techniques will be reviewed.

  7. Ethylene glycol, hazardous substance in the household.

    PubMed

    Patocka, Jirí; Hon, Zdenek

    2010-01-01

    Ethylene glycol is a colorless, odorless, sweet-tasting but poisonous type of alcohol found in many household products. The major use of ethylene glycol is as an antifreeze in, for example, automobiles, in air conditioning systems, in de-icing fluid for windshields, and else. People sometimes drink ethylene glycol mistakenly or on purpose as a substitute for alcohol. Ethylene glycol is toxic, and its drinking should be considered a medical emergency. The major danger from ethylene glycol is following ingestion. Due to its sweet taste, peoples and occasionally animals will sometimes consume large quantities of it if given access to antifreeze. While ethylene glycol itself has a relatively low degree of toxicity, its metabolites are responsible for extensive cellular damage to various tissues, especially the kidneys. This injury is caused by the metabolites, glycolic and oxalic acid and their respective salts, through crystal formation and possibly other mechanisms. Toxic metabolites of ethylene glycol can damage the brain, liver, kidneys, and lungs. The poisoning causes disturbances in the metabolism pathways, including metabolic acidosis. The disturbances may be severe enough to cause profound shock, organ failure, and death. Ethylene glycol is a common poisoning requiring antidotal treatment. PMID:20608228

  8. Stereolithography of spatially controlled multi-material bioactive poly(ethylene glycol) scaffolds.

    PubMed

    Arcaute, Karina; Mann, Brenda; Wicker, Ryan

    2010-03-01

    Challenges remain in tissue engineering to control the spatial, mechanical, temporal and biochemical architectures of scaffolds. Unique capabilities of stereolithography (SL) for fabricating multi-material spatially controlled bioactive scaffolds were explored in this work. To accomplish multi-material builds, a mini-vat setup was designed allowing for self-aligning X-Y registration during fabrication. The mini-vat setup allowed the part to be easily removed and rinsed, and different photocrosslinkable solutions to be easily removed and added to the vat. Two photocrosslinkable hydrogel biopolymers, poly(ethylene glycol) dimethacrylate (PEG-dma, MW 1000) and poly(ethylene glycol) diacrylate (PEG-da, MW 3400), were used as the primary scaffold materials. Multi-material scaffolds were fabricated by including controlled concentrations of fluorescently labeled dextran, fluorescently labeled bioactive PEG or bioactive PEG in different regions of the scaffold. The presence of the fluorescent component in specific regions of the scaffold was analyzed with fluorescent microscopy, while human dermal fibroblast cells were seeded on top of the fabricated scaffolds with selective bioactivity and phase contrast microscopy images were used to show specific localization of cells in the regions patterned with bioactive PEG. Multi-material spatial control was successfully demonstrated in features down to 500 microm. In addition, the equilibrium swelling behavior of the two biopolymers after SL fabrication was determined and used to design constructs with the specified dimensions at the swollen state. The use of multi-material SL and the relative ease of conjugating different bioactive ligands or growth factors to PEG allows for the fabrication of tailored three-dimensional constructs with specified spatially controlled bioactivity.

  9. The effects of different additives on the dielectric relaxation and the dynamic mechanical properties of urethane dimethacrylate.

    PubMed

    Mohsen, N M; Craig, R G; Filisko, F E

    2000-03-01

    The polymer-filler interaction of a dental composite was examined by dielectric measurements to determine how a non-compatible inorganic phase modifies the molecular behaviour of the polymer chains and how modification of this phase by silanation can affect these molecular behaviours. Urethane dimethacrylate (UDMA) monomer and zirconia-silica (ZS) powder were used as organic and inorganic phases, respectively. 3-Acryloxypropyltrimethoxysilane (MAPM) and 4-aminobutyltriethoxysilane (ABTE) were used as silanating coupling agents. The components of the composite were mixed in different ratios after treating the filler with from 0 to 30 times the minimum uniform coverage with the silane, then the composite was made into thin films. The dielectric spectra of five replicas for each filler-monomer ratio were measured, and three replicas were measured for each silane and for each amount of silane used to treat the filler. Increasing the filler concentration in the composites decreased the intensity of Tan(delta)epsilon for the alpha- and beta-relaxations, where the beta-relaxations also became broader and the alpha-relaxations were totally obstructed. The alpha-relaxations were shifted to higher temperatures, while the beta-relaxations were shifted to lower temperatures. Filler treatment with small amounts of MAPM shifted the alpha-relaxations to higher temperatures; they were shifted back to lower temperatures when the filler was treated with large amounts of silane. Filler treatment with large amounts of ABTE (30-fold) caused an extra peak to emerge in the high-temperature region. It can be concluded that increasing filler concentration restricts the mobility of the main chains and decreases the thickness of the surface layer, while allowing more movement of the local chains. Filler treatment with MAPM was shown to be a compatible coupling agent with the ZS and the UDMA systems. Such compatibility was observed through the effectiveness of the chemical linkage of the

  10. The effects of different additives on the dielectric relaxation and the dynamic mechanical properties of urethane dimethacrylate.

    PubMed

    Mohsen, N M; Craig, R G; Filisko, F E

    2000-03-01

    The polymer-filler interaction of a dental composite was examined by dielectric measurements to determine how a non-compatible inorganic phase modifies the molecular behaviour of the polymer chains and how modification of this phase by silanation can affect these molecular behaviours. Urethane dimethacrylate (UDMA) monomer and zirconia-silica (ZS) powder were used as organic and inorganic phases, respectively. 3-Acryloxypropyltrimethoxysilane (MAPM) and 4-aminobutyltriethoxysilane (ABTE) were used as silanating coupling agents. The components of the composite were mixed in different ratios after treating the filler with from 0 to 30 times the minimum uniform coverage with the silane, then the composite was made into thin films. The dielectric spectra of five replicas for each filler-monomer ratio were measured, and three replicas were measured for each silane and for each amount of silane used to treat the filler. Increasing the filler concentration in the composites decreased the intensity of Tan(delta)epsilon for the alpha- and beta-relaxations, where the beta-relaxations also became broader and the alpha-relaxations were totally obstructed. The alpha-relaxations were shifted to higher temperatures, while the beta-relaxations were shifted to lower temperatures. Filler treatment with small amounts of MAPM shifted the alpha-relaxations to higher temperatures; they were shifted back to lower temperatures when the filler was treated with large amounts of silane. Filler treatment with large amounts of ABTE (30-fold) caused an extra peak to emerge in the high-temperature region. It can be concluded that increasing filler concentration restricts the mobility of the main chains and decreases the thickness of the surface layer, while allowing more movement of the local chains. Filler treatment with MAPM was shown to be a compatible coupling agent with the ZS and the UDMA systems. Such compatibility was observed through the effectiveness of the chemical linkage of the

  11. Ethylene Glycol Metabolism by Pseudomonas putida

    PubMed Central

    Mückschel, Björn; Simon, Oliver; Klebensberger, Janosch; Graf, Nadja; Rosche, Bettina; Altenbuchner, Josef; Pfannstiel, Jens; Huber, Armin

    2012-01-01

    In this study, we investigated the metabolism of ethylene glycol in the Pseudomonas putida strains KT2440 and JM37 by employing growth and bioconversion experiments, directed mutagenesis, and proteome analysis. We found that strain JM37 grew rapidly with ethylene glycol as a sole source of carbon and energy, while strain KT2440 did not grow within 2 days of incubation under the same conditions. However, bioconversion experiments revealed metabolism of ethylene glycol by both strains, with the temporal accumulation of glycolic acid and glyoxylic acid for strain KT2440. This accumulation was further increased by targeted mutagenesis. The key enzymes and specific differences between the two strains were identified by comparative proteomics. In P. putida JM37, tartronate semialdehyde synthase (Gcl), malate synthase (GlcB), and isocitrate lyase (AceA) were found to be induced in the presence of ethylene glycol or glyoxylic acid. Under the same conditions, strain KT2440 showed induction of AceA only. Despite this difference, the two strains were found to use similar periplasmic dehydrogenases for the initial oxidation step of ethylene glycol, namely, the two redundant pyrroloquinoline quinone (PQQ)-dependent enzymes PedE and PedH. From these results we constructed a new pathway for the metabolism of ethylene glycol in P. putida. Furthermore, we conclude that Pseudomonas putida might serve as a useful platform from which to establish a whole-cell biocatalyst for the production of glyoxylic acid from ethylene glycol. PMID:23023748

  12. Ethylene glycol metabolism by Pseudomonas putida.

    PubMed

    Mückschel, Björn; Simon, Oliver; Klebensberger, Janosch; Graf, Nadja; Rosche, Bettina; Altenbuchner, Josef; Pfannstiel, Jens; Huber, Armin; Hauer, Bernhard

    2012-12-01

    In this study, we investigated the metabolism of ethylene glycol in the Pseudomonas putida strains KT2440 and JM37 by employing growth and bioconversion experiments, directed mutagenesis, and proteome analysis. We found that strain JM37 grew rapidly with ethylene glycol as a sole source of carbon and energy, while strain KT2440 did not grow within 2 days of incubation under the same conditions. However, bioconversion experiments revealed metabolism of ethylene glycol by both strains, with the temporal accumulation of glycolic acid and glyoxylic acid for strain KT2440. This accumulation was further increased by targeted mutagenesis. The key enzymes and specific differences between the two strains were identified by comparative proteomics. In P. putida JM37, tartronate semialdehyde synthase (Gcl), malate synthase (GlcB), and isocitrate lyase (AceA) were found to be induced in the presence of ethylene glycol or glyoxylic acid. Under the same conditions, strain KT2440 showed induction of AceA only. Despite this difference, the two strains were found to use similar periplasmic dehydrogenases for the initial oxidation step of ethylene glycol, namely, the two redundant pyrroloquinoline quinone (PQQ)-dependent enzymes PedE and PedH. From these results we constructed a new pathway for the metabolism of ethylene glycol in P. putida. Furthermore, we conclude that Pseudomonas putida might serve as a useful platform from which to establish a whole-cell biocatalyst for the production of glyoxylic acid from ethylene glycol.

  13. The Occurrence of Glycolate Dehydrogenase and Glycolate Oxidase in Green Plants

    PubMed Central

    Frederick, Sue Ellen; Gruber, Peter J.; Tolbert, N. E.

    1973-01-01

    Homogenates of various lower land plants, aquatic angiosperms, and green algae were assayed for glycolate oxidase, a peroxisomal enzyme present in green leaves of higher plants, and for glycolate dehydrogenase, a functionally analogous enzyme characteristic of certain green algae. Green tissues of all lower land plants examined (including mosses, liverworts, ferns, and fern allies), as well as three freshwater aquatic angiosperms, contained an enzyme resembling glycolate oxidase, in that it oxidized l- but not d-lactate in addition to glycolate, and was insensitive to 2 mm cyanide. Many of the green algae (including Chlorella vulgaris, previously claimed to have glycolate oxidase) contained an enzyme resembling glycolate dehydrogenase, in that it oxidized d- but not l-lactate, and was inhibited by 2 mm cyanide. Other green algae had activity characteristic of glycolate oxidase and, accordingly, showed a substantial glycolate-dependent O2 uptake. It is pointed out that this distribution pattern of glycolate oxidase and glycolate dehydrogenase among the green plants may have phylogenetic significance. Activities of catalase, a marker enzyme for peroxisomes, were also determined and were generally lower in the algae than in the land plants or aquatic angiosperms. Among the algae, however, there were no consistent correlations between levels of catalase and the type of enzyme which oxidized glycolate. PMID:16658555

  14. Enhanced bioconversion of ethylene glycol to glycolic acid by a newly isolated Burkholderia sp. EG13.

    PubMed

    Gao, Xiaoxin; Ma, Zhengfei; Yang, Limin; Ma, Jiangquan

    2014-10-01

    Burkholderia sp. EG13 with high ethylene glycol-oxidizing activity was isolated from soil, which could be used for the synthesis of glycolic acid from the oxidation of ethylene glycol. Using the resting cells of Burkholderia sp. EG13 as biocatalysts, the optimum reaction temperature and pH were 30 °C and 6.0, respectively. After 24 h of biotransformation, the yield of glycolic acid from 200 mM ethylene glycol was 98.8 %. Furthermore, an integrated bioprocess for the production of glycolic acid which involved in situ product removal (ISPR) was investigated. Using fed-batch method with ISPR, a total of 793 mM glycolic acid has been accumulated in the reaction mixture after the 4th feed.

  15. Propylene Glycol Toxicity in Children

    PubMed Central

    Poole, Robert L.; Pageler, Natalie M.

    2014-01-01

    Propylene glycol (PG) is a commonly used solvent for oral, intravenous, and topical pharmaceutical agents. Although PG is generally considered safe, when used in high doses or for prolonged periods, PG toxicity can occur. Reported adverse effects from PG include central nervous system (CNS) toxicity, hyperosmolarity, hemolysis, cardiac arrhythmia, seizures, agitation, and lactic acidosis. Patients at risk for toxicity include infants, those with renal or hepatic insuficiency, epilepsy, and burn patients receiving extensive dermal applications of PG containing products. Laboratory monitoring of PG levels, osmolarity, lactate, pyruvate, bicarbonate, creatinine, and anion gap can assist practitioners in making the diagnosis of PG toxicity. Numerous studies and case reports have been published on PG toxicity in adults. However, very few have been reported in pediatric patient populations. A review of the literature is presented. PMID:25762872

  16. Radiation synthesis of poly[(dimethylaminoethyl methacrylate)-co-(ethyleneglycol dimethacrylate)] hydrogels and its application as a carrier for anticancer delivery

    NASA Astrophysics Data System (ADS)

    Mazied, Nabila A.; Ismail, Sahar A.; Abou Taleb, Manal F.

    2009-11-01

    The use of hydrogels as carriers for anticancer delivery has been a subject of significant recent research. In our recent work, we have shown that diffusion-controlled delivery of flutamide from hydrogels containing poly (dimethylaminoethyl methacrylate (DMAEMA)/ethyleneglycol dimethacrylate (EGDMA)) can be possible and controlled by the three-dimensional structure. Hydrogels based essentially on dimethylaminoethyl methacrylate and different ratios of ethyleneglycol dimethacrylate monomers were synthesized using gamma radiation copolymerization. The influence of copolymer composition and pH value of the surrounding medium on swelling behavior into the glassy polymer were discussed. The results showed that the ratio of EGDMA in the comonomer feeding solution has a great effect on the gel fraction and water content in the final hydrogel. In this regard, it was observed that the increase of EGDMA ratio decreased these properties. The ability of the prepared copolymer to be used as drug carrier for anticancer drug-delivery system was estimated using flutamide as a model drug. In vitro drug-release studies in different buffer solutions show that the basic parameters affecting the drug release behavior of hydrogel are the pH of the solution and DMAEMA content of hydrogel.

  17. Glycolic acid modulates the mechanical property and degradation of poly(glycerol, sebacate, glycolic acid).

    PubMed

    Sun, Zhi-Jie; Wu, Lan; Huang, Wei; Chen, Chang; Chen, Yan; Lu, Xi-Li; Zhang, Xiao-Lan; Yang, Bao-Feng; Dong, De-Li

    2010-01-01

    The development of biodegradable materials with controllable degradation properties is beneficial for a variety of applications. Poly(glycerol-sebacate) (PGS) is a promising candidate of biomaterials; so we synthesize a series of poly(glycerol, sebacate, glycolic acid) (PGSG) with 1:2:0, 1:2:0.2, 1:2:0.4, 1:2:0.6, 1:2:1 mole ratio of glycerol, sebacate, and glycolic acid to elucidate the relation of doped glycolic acid to the degradation rate and mechanical properties. The microstructures of the polymers with different doping of glycolic acid were dissimilar. PGSG with glycolic acid in the ratio of 0.2 displayed an integral degree of ordering, different to those with glycolic acid in the ratio of 0, 0.4, 0.6, and 1, which showed mild phase separation structure. The number, DeltaH(m), and temperature of the PGSG melting peaks tended to decrease with the increasing ratio of doped glycolic acid. In vitro and in vivo degradation tests showed that the degradation rate of PGSG with glycolic acid in the ratio of 0.2 was slowest, but in the ratio range of 0, 0.4, and 0.6, the degradation rate increased with the increase of glycolic acid. All PGSG samples displayed good tissue response and anticoagulant effects. Our data suggest that doping glycolic acid can modulate the microstructure and degree of crosslinking of PGS, thereby control the degradation rate of PGS.

  18. 21 CFR 184.1666 - Propylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p....

  19. 21 CFR 184.1666 - Propylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p....

  20. 21 CFR 184.1666 - Propylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p....

  1. 21 CFR 184.1666 - Propylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p....

  2. GLYCOLATE METABOLISM IN ESCHERICHIA COLI1

    PubMed Central

    Hansen, Robert W.; Hayashi, James A.

    1962-01-01

    Hansen, Robert W. (University of Illinois College of Medicine, Chicago) and James A. Hayashi. Glycolate metabolism in Escherichia coli. J. Bacteriol. 83:679–687. 1962.—This study of glycolate-adapted Escherichia coli indicates that the most probable route for utilization of the substrate includes glyceric acid, 3-phosphoglyceric acid, and the tricarboxylic acid cycle. A glyceric acid dehydrogenase, which reduces tartronic semialdehyde to glycerate in the presence of reduced diphosphopyridine nucleotide, and a kinase, which catalyzes the formation of 3-phosphoglycerate from glyceric acid and adenosine triphosphate, were shown to be present. Carbon recoveries in growing cultures and manometric data obtained with resting cells showed the complete oxidation of glycolate to carbon dioxide. Measurements of the oxidation of tricarboxylic acid cycle intermediates indicated that these compounds are oxidized without lag and at a rate commensurate with the rate of glycolate oxidation. Assays of the enzymes characteristic of known pathways of terminal oxidation, such as isocitratase, malate synthetase, isocitric dehydrogenase, and condensing enzyme, provided further evidence for an operating tricarboxylic acid cycle. A postulated pathway for the utilization of glycolic acid is as follows: glycolate → glycerate → 3-phosphoglycerate → pyruvate → tricarboxylic acid cycle. PMID:13904441

  3. Optimizing the concentration of quaternary ammonium dimethacrylate monomer in bis-GMA/TEGDMA dental resin system for antibacterial activity and mechanical properties.

    PubMed

    Liang, Xiaoxu; Söderling, Eva; Liu, Fang; He, Jingwei; Lassila, Lippo V J; Vallittu, Pekka K

    2014-05-01

    Four novel quaternary ammonium dimethacrylate monomers named IMQ (side alkyl chain length from 12 to 18) were synthesized with the aim to synthesize dental resin with antibacterial activity. All of IMQs were added into bis-GMA/TEGDMA dental resin system with a series of mass ratio (5, 10, and 20 wt%), double bond conversion (DC), flexural strength (FS), modulus of elasticity (FM) and biofilm formation inhibitory effect were studied. According to the results of DC, FS, FM, and the biofilm inhibitory effect, IMQ-16 containing polymer had the best comprehensive properties, and the optimal concentration of IMQ-16 in bis-GMA/TEGDMA dental resin would be in the range of 5-10 wt%.

  4. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (generic). 721.10518 Section 721.10518 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES...

  5. Fabrication of poly(ethylene glycol): gelatin methacrylate composite nanostructures with tunable stiffness and degradation for vascular tissue engineering.

    PubMed

    Kim, Peter; Yuan, Alex; Nam, Ki-Hwan; Jiao, Alex; Kim, Deok-Ho

    2014-06-01

    Although synthetic polymers are desirable in tissue engineering applications for the reproducibility and tunability of their properties, synthetic small diameter vascular grafts lack the capability to endothelialize in vivo. Thus, synthetically fabricated biodegradable tissue scaffolds that reproduce important aspects of the extracellular environment are required to meet the urgent need for improved vascular grafting materials. In this study, we have successfully fabricated well-defined nanopatterned cell culture substrates made of a biodegradable composite hydrogel consisting of poly(ethylene glycol) dimethacrylate (PEGDMA) and gelatin methacrylate (GelMA) by using UV-assisted capillary force lithography. The elasticity and degradation rate of the composite PEG-GelMA nanostructures were tuned by varying the ratios of PEGDMA and GelMA. Human umbilical vein endothelial cells (HUVECs) cultured on nanopatterned PEG-GelMA substrates exhibited enhanced cell attachment compared with those cultured on unpatterned PEG-GelMA substrates. Additionally, HUVECs cultured on nanopatterned PEG-GelM substrates displayed well-aligned, elongated morphology similar to that of native vascular endothelial cells and demonstrated rapid and directionally persistent migration. The ability to alter both substrate stiffness and degradation rate and culture endothelial cells with increased elongation and alignment is a promising next step in recapitulating the properties of native human vascular tissue for tissue engineering applications.

  6. Swelling properties of copolymeric hydrogels of poly(ethylene glycol) monomethacrylate and monoesters of itaconic acid for use in drug delivery.

    PubMed

    Teijón, César; Guerrero, Sandra; Olmo, Rosa; Teijón, José M; Blanco, M Dolores

    2009-11-01

    Copolymeric hydrogels of poly(ethylene glycol) monomethacrylate (PEGMA) (P) have been synthesized for use in drug-delivery. New copolymeric hydrogels were prepared by free radical solution polymerization of PEGMA and monomethyl itaconate (MMI) or monoethyl itaconate (MEI), using ethyleneglycol dimethacrylate and tetraethyleneglycol dimethacrylate, respectively, as cross-linkers. The effect of copolymer composition on swelling behavior, thermal decomposition and drug release was studied. Three compositions of each copolymer were studied: 70P/30MMI (or MEI), 80P/20MMI (or MEI) and 90P/10MMI (or MEI). The largest equilibrium swelling degree was observed in gels containing the highest content of MMI or MEI (84.22 +/- 0.22 wt % for 70P/30MEI; 79.56 +/- 0.64 wt % for 70P/30MMI). The swelling process was in accordance with Fick's Second Law. Methotrexate (MTX), an anticancer agent used in the treatment of different hyperproliferative epithelial diseases, was chosen to be loaded in the gels. The drug was included by immersion of the copolymeric disks in an aqueous solution of the drug. The amount of MTX in the xerogels was between 5.34 +/- 0.06 mg MTX/g (90P/10MMI) and 14.94 +/- 0.91 mg MTX/g (80P/20MEI). Two stages of thermal degradation for unloaded and MTX-loaded gels were determined; the presence of the drug in the polymeric matrices decreased the temperature of the first stage of thermal degradation. MTX release was also in accordance with Fick's Second Law. The length of total drug release (340 +/- 30 min-1502 +/- 81 min) could be modulated as a function of the comonomer composition of the hydrogel.

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

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1989-01-01

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

  8. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Ethylene glycol: Commercial grade. Purify if necessary, by distillation. Diethylene glycol: Commercial grade. Purify, if necessary, by distillation. Glycol standards: Prepare chromatographic standards...

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

    MedlinePlus

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

  10. Complete recovery after massive ethylene glycol ingestion.

    PubMed

    Curtin, L; Kraner, J; Wine, H; Savitt, D; Abuelo, J G

    1992-06-01

    We treated a 64-year-old man who recovered completely from a massive antifreeze ingestion with ethylene glycol levels well above those of previously described survivors. Rapid and aggressive treatment of the patient with recognized methods, including hemodialysis, resulted in the favorable outcome.

  11. Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol)

    Integrated Risk Information System (IRIS)

    Ethylene glycol monobutyl ether ( EGBE ) ( 2 - Butoxyethanol ) ; CASRN 111 - 76 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I (

  12. Novel biotreatment process for glycol waters

    SciTech Connect

    Raja, L.M.V.; Elamvaluthy, G.; Palaniappan, R.; Krishnan, R.M.

    1991-12-31

    Propylene oxide (PO), propylene glycol (PG), and polyols are produced from propylene via propylene chlorohydrin. Effluents from these plants contain biological oxygen demand/chemical oxygen demand (BOD/COD) loads besides high chloride concentrations. The high salinity poses severe problem to adopt conventional methods like activated sludge processes. Presently, a simple, economically viable and versatile microbiological process has been developed to get more than 90% biodegradation in terms of BOD/COD, utilizing specially developed Pseudomonas and Aerobacter. The process can tolerate high salinity up to 10 wt% NaCl or 5 wt% CaCl{sub 2} and can withstand wide variations in pH (5.5-11.0) and temperature (15-45{degrees}C). The biodegradation of glycols involves two steps. The enzymatic conversion of glycols to carboxylic and hydroxycarboxylic acids is aided by Pseudoomonas. Further degradation to CO{sub 2} and H{sub 2}O by carboxylic acid utilizing Aerobacter, and possible metabolic degradative pathway of glycols are discussed. Various process parameters obtained in the lab scale (50 L bioreactor) and pilot scale (20 m{sup 3} bioreactor), and unique features of our process are also discussed.

  13. 21 CFR 184.1666 - Propylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol. 184.1666 Section 184.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed...

  14. 21 CFR 582.1666 - Propylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... is generally recognized as safe (except in cat food) when used in accordance with good...

  15. 21 CFR 582.1666 - Propylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... is generally recognized as safe (except in cat food) when used in accordance with good...

  16. Methacrylated glycol chitosan as a photopolymerizable biomaterial.

    PubMed

    Amsden, Brian G; Sukarto, Abby; Knight, Darryl K; Shapka, Stephen N

    2007-12-01

    Glycol chitosan is a derivative of chitosan that is soluble at neutral pH and possesses potentially useful biological properties. With the goal of obtaining biocompatible hydrogels for use as tissue engineering scaffolds or drug delivery depots, glycol chitosan was converted to a photopolymerizable prepolymer through graft methacrylation using glycidyl methacrylate in aqueous media at pH 9. N-Methacrylation was verified by both (1)H NMR and (13)C NMR. The degree of N-methacrylation, measured via (1)H NMR, was easily varied from 1.5% to approximately 25% by varying the molar ratio of glycidyl methacrylate to glycol chitosan and the reaction time. Using a chondrocyte cell line, the N-methacrylated glycol chitosan was found to be noncytotoxic up to a concentration of 1 mg/mL. The prepolymer was cross-linked in solution using UV light and Irgacure 2959 photoinitiator under various conditions to yield gels of low sol content ( approximately 5%), high equilibrium water content (85-95%), and thicknesses of up to 6 mm. Cross-polarization magic-angle spinning (13)C solid state NMR verified the complete conversion of the double bonds in the gel. Chondrocytes seeded directly onto the gel surface, populated the entirety of the gel and remained viable for up to one week. The hydrogels degraded slowly in vitro in the presence of lysozyme at a rate that increased as the cross-link density of the gels decreased. PMID:18031015

  17. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  18. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  19. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Dipropylene glycol dimethyl ether. 721... Substances § 721.3550 Dipropylene glycol dimethyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as dipropylene glycol dimethyl ether (PMN...

  20. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dipropylene glycol dimethyl ether. 721... Substances § 721.3550 Dipropylene glycol dimethyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as dipropylene glycol dimethyl ether (PMN...

  1. Effects of low temperature on the biodegradation of ethylene glycol and propylene glycol

    SciTech Connect

    Williams, J.B.; Blessing, R.L.

    1995-12-31

    Ethylene glycol and propylene glycol are used in a variety of applications. These compounds are well known to biodegrade readily at 20 C, which is the benchmark temperature for most biodegradation studies. These compounds may enter the environment when the ambient temperatures are significantly below 20 C. Biodegradation data at low temperatures was needed. For example, wintertime airport stormwater discharges contain glycols from deicing fluids. These compounds may enter streams at ambient winter temperatures, or wastewater treatment works which may be operating at temperatures well below 20 C. Biodegradation studies were conducted with BOD bottles incubated at 40 C and 10 C. Biodegradation was slower than 20 C but still significant. For ethylene glycol, the half-life (time at which one-half of the oxygen demand was consumed by the microorganisms) was 5 days at 20 C, 8 days at 10 C, and 25 days at 40 C. For propylene glycol, the half-life was 5 days at 20 C, 12 days at 10 C, and 28 days at 40 C. Two aircraft deicing fluids were also tested, and similar degradation rates were observed. This indicates the presence of additives in deicing fluids has little effect on biodegradation of glycols.

  2. Chromatographic separation of proteins on metal immobilized iminodiacetic acid-bound molded monolithic rods of macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate).

    PubMed

    Luo, Q; Zou, H; Xiao, X; Guo, Z; Kong, L; Mao, X

    2001-08-17

    Continuous rod of macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate) was prepared by a free radical polymerization within the confines of a stainless-steel column. The epoxide groups of the rod were modified by a reaction with iminodiacetic acid (IDA) that affords the active site to form metal IDA chelates used for immobilized metal affinity chromatography (IMAC). The efficiency of coupling of IDA to the epoxide-contained matrix was studied as a function of reaction time and temperature. High-performance separation of proteins, based on immobilized different metals on the column, were described. The influence of pH on the adsorption capacity of bovine serum albumin on the Cu2+-IDA continuous rod column was investigated in the range from 5.0 to 9.0. Purification of lysozyme from egg white and human serum albumin (HSA) on the commercially available HSA solution were performed on the naked IDA and Cu2+-IDA continuous rod columns, respectively; and the purity of the obtained fractions was detected by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. PMID:11556331

  3. In situ reactive compatibilization of polypropylene/ethylene-propylene-diene monomer thermoplastic vulcanizate by zinc dimethacrylate via peroxide-induced dynamic vulcanization.

    PubMed

    Chen, Yukun; Xu, Chuanhui; Liang, Xingquan; Cao, Liming

    2013-09-12

    This work demonstrates an approach of in situ reactive compatibilization between polypropylene (PP) and ethylene-propylene-diene monomer (EPDM) by using zinc dimethacrylate (ZDMA) as a compatibilizer and, simultaneously, as a very strong reinforcing agent. With the incorporation of 7phr ZDMA in the PP/EPDM (30/70, w/w) thermoplastic vulcanizate (TPV), the tensile strength, tear strength, elongation at break, and hardness of PP/EPDM/ZDMA TPV were increased from 5.3 MPa, 31.3 kN/m, 222%, and 78 up to 11.2 MPa, 64.2 kN/m, 396%, and 83, respectively. This tremendous reinforcing as well as the compatibilization effect of the ZDMA was understood by polymerization of ZDMA and ZDMA reacted with EPDM and PP during peroxide-induced dynamic vulcanization. A peculiar phase structure that rubber particles were surrounded and "bonded" by a thick transition zone that contained numerous of nanoparticles with dimensions of about 20-30 nm was observed from transmission electron microscopy. Scanning electron microscopy results confirmed that incorporation of ZDMA reduced the size of the cross-linked EPDM particles. Moreover, we found that the compatibilized TPV showed a higher tan δ peak temperature for EPDM phase and a lower tan δ peak temperature for PP phase. The suggested method for in situ reactive compatibilization of PP and EPDM offers routes to the design of new TPV-based technical products for diversified applications. PMID:23981036

  4. Morphology study of peroxide-induced dynamically vulcanized polypropylene/ethylene-propylene-diene monomer/zinc dimethacrylate blends during tensile deformation.

    PubMed

    Chen, Yukun; Xu, Chuanhui; Cao, Liming; Wang, Yanpeng; Fang, Liming

    2013-06-27

    Polypropylene (PP)/ethylene-propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blend (EPDM/PP ratio of 30/70) with remarkable extensibility was successfully prepared via peroxide dynamic vulcanization. The uniaxial tensile properties, crystallization behavior, structure, and morphology during stretching were investigated. The tensile process study showed that the PP/EPDM/ZDMA blend exhibited the rubbery-like behavior with an elongation beyond 600%. The ZDMA graft-product domain increased the compatibility and interfacial adhesion between rubber and PP phases, while it reduced the crystallinity of the PP phase. On the basis of TEM and SEM analyses, we found that the cross-linked rubber particles could be elongated and oriented along the tensile direction, whereas the ZDMA graft-product domain "encapsulated" rubber phase together, acting as a "bridge" between elongated rubber phases and the PP phase during uniaxial stretching. The stress could be effectively transferred from the PP phase to the numerous elongated rubber phases due to the excellent compatibility and interfacial adhesion between rubber and PP phases, resulting in the rubbery-like behavior. PMID:23742700

  5. Separation of alpha-, beta-, gamma-, delta-tocopherols and alpha-tocopherol acetate on a pentaerythritol diacrylate monostearate-ethylene dimethacrylate monolith by capillary electrochromatography.

    PubMed

    Chaisuwan, Patcharin; Nacapricha, Duangjai; Wilairat, Prapin; Jiang, Zhengjin; Smith, Norman W

    2008-06-01

    This work reports the first use of a monolith with method development for the separation of tocopherol (TOH) compounds by CEC with UV detection. A pentaerythritol diacrylate monostearate-ethylene dimethacrylate (PEDAS-EDMA) monolithic column has been investigated for an optimised condition to separate alpha-, beta-, gamma- and delta-TOHs, and alpha-tocopherol acetate (TAc). The PEDAS-EDMA monolith showed a remarkably good selectivity for separation of the TOH isomers including the beta- and gamma-isomers which are not easily separated by standard C8 or C18 particle-packed columns. Retention studies indicated that an RP mechanism was involved in the separation on the PEDAS-EDMA column, but polar interactions with the underlying ester and hydroxyl groups enhanced the separation of the problematic beta- and gamma-isomers. Separation of all the compounds was achieved within 25 min using 3:10:87 v/v/v 100 mM Tris buffer (pH 9.3)/methanol/ACN as the mobile phase. The method was successfully applied to a pharmaceutical sample with recoveries from 93 to 99%. Intraday and interday precisions (%RSD) for peak area and retention time were less than 2.3. LODs for all four TOHs and TAc were below 1 ppm.

  6. In situ reactive compatibilization of polypropylene/ethylene-propylene-diene monomer thermoplastic vulcanizate by zinc dimethacrylate via peroxide-induced dynamic vulcanization.

    PubMed

    Chen, Yukun; Xu, Chuanhui; Liang, Xingquan; Cao, Liming

    2013-09-12

    This work demonstrates an approach of in situ reactive compatibilization between polypropylene (PP) and ethylene-propylene-diene monomer (EPDM) by using zinc dimethacrylate (ZDMA) as a compatibilizer and, simultaneously, as a very strong reinforcing agent. With the incorporation of 7phr ZDMA in the PP/EPDM (30/70, w/w) thermoplastic vulcanizate (TPV), the tensile strength, tear strength, elongation at break, and hardness of PP/EPDM/ZDMA TPV were increased from 5.3 MPa, 31.3 kN/m, 222%, and 78 up to 11.2 MPa, 64.2 kN/m, 396%, and 83, respectively. This tremendous reinforcing as well as the compatibilization effect of the ZDMA was understood by polymerization of ZDMA and ZDMA reacted with EPDM and PP during peroxide-induced dynamic vulcanization. A peculiar phase structure that rubber particles were surrounded and "bonded" by a thick transition zone that contained numerous of nanoparticles with dimensions of about 20-30 nm was observed from transmission electron microscopy. Scanning electron microscopy results confirmed that incorporation of ZDMA reduced the size of the cross-linked EPDM particles. Moreover, we found that the compatibilized TPV showed a higher tan δ peak temperature for EPDM phase and a lower tan δ peak temperature for PP phase. The suggested method for in situ reactive compatibilization of PP and EPDM offers routes to the design of new TPV-based technical products for diversified applications.

  7. In Vitro Solubility and Wear Rates of Silorane and Dimethacrylate Resin Based Composite Restorative Materials under Different pH Conditions

    PubMed Central

    Soliman, Tarek A; Tubaigy, Khalid M; Raffat, Eman M; Al-Agha, Ebaa I

    2015-01-01

    Background: The purpose of this study was to evaluate the effect of different pH solutions on the solubility and wear resistance of Silorane and dimethacrylate resin based composite restorative materials. Materials and Methods: Two different resin based restorative materials (Filtek Silorane P90 and hybrid composite Z100) were tested. Different pH solutions (2.5 and 5) also were used. A total of 60 samples of each type of selected composite were prepared. Specimens were immersed in each type of pH solutions (2.5 and 5) and distilled water as a control group for 24 h then the specimens was subjected to the required mechanical tests. Results: Significant statistical differences were observed regarding water solubility and wear values in different pH solutions. Filtek Silorane presented the smallest values of water solubility and wear values. Conclusion: Under tested experimental conditions, the pH solutions used in this study showed pronounced effect on water solubility and wear values of both two restorative materials. Finally, within the limitation of this study we recommended to use Filtek Silorane (P90) instead of hybrid (Z100) due to its low solubility values under different pH solutions. PMID:26225097

  8. Certain glycol ethers eliminated from toxic chemical release reporting requirements

    SciTech Connect

    1994-09-01

    Effective June 28, 1994, the U.S. Environmental Protection Agency (EPA) eliminated high molecular weight glycol ethers from the reporting requirements of section 313 of the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA). EPCRA (42 U.S.C. 11023) is also referred to as Title III of the Superfund Amendments and Reauthorization Act (SARA) of 1986. EPA redefined the glycol ethers category list of chemicals subject to reporting based on an EPA review of available human health data on short-chain glycol ethers. EPA is removing only the surfactant glycol ethers, which are high molecular weight glycol ethers, i.e., those with pendant alkyl groups and that typically have eight or more carbon atoms. The redefinition retains certain glycol ethers (i.e., ethylene glycol ethers where there are 1,2, or 3 repeating ethylene oxide groups) in the category. These are reasonably anticipated to cause adverse human health effects.

  9. Glycolic acid peel therapy - a current review.

    PubMed

    Sharad, Jaishree

    2013-01-01

    Chemical peels have been time-tested and are here to stay. Alpha-hydroxy peels are highly popular in the dermatologist's arsenal of procedures. Glycolic acid peel is the most common alpha-hydroxy acid peel, also known as fruit peel. It is simple, inexpensive, and has no downtime. This review talks about various studies of glycolic acid peels for various indications, such as acne, acne scars, melasma, postinflammatory hyperpigmentation, photoaging, and seborrhea. Combination therapies and treatment procedure are also discussed. Careful review of medical history, examination of the skin, and pre-peel priming of skin are important before every peel. Proper patient selection, peel timing, and neutralization on-time will ensure good results, with no side effects. Depth of the glycolic acid peel depends on the concentration of the acid used, the number of coats applied, and the time for which it is applied. Hence, it can be used as a very superficial peel, or even a medium depth peel. It has been found to be very safe with Fitzpatrick skin types I-IV. All in all, it is a peel that is here to stay. PMID:24399880

  10. Relative toxicities of formulated glycol aircraft deicers and pure glycol products to duckweed (Lemna minor)

    SciTech Connect

    DuFresne, D.L.; Pillard, D.A.

    1995-12-31

    Ethylene and propylene glycol deicers are commonly used at airports in the US and other countries to both remove snow and ice from aircraft, and to retard the accumulation of those materials. Snow and ice often pile up at airports during the winter and are then flushed into the storm sewer system during warmer temperatures or rainfall. Some of this water containing deicers may enter waterbodies without prior treatment, While previous studies have investigated the effects of deicers on aquatic animals and algae, data are not available on the effects on aquatic macrophytes, Glycol deicers were obtained in the formulated mixtures used on aircraft; pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Duckweed (Lemna minor) fronds were exposed to various concentrations of pure and formulated glycol mixtures. The number of fronds at test termination and chlorophyll concentration (measured using a spectrophotometer) were the measured endpoints. Based upon glycol concentration, the formulated products were more toxic than the pure material. These results are consistent with results seen in other animal and plant studies.

  11. Endocrine-Disrupting Potential of Bisphenol A, Bisphenol A Dimethacrylate, 4-n-Nonylphenol, and 4-n-Octylphenol in Vitro: New Data and a Brief Review

    PubMed Central

    Bonefeld-Jørgensen, Eva C.; Long, Manhai; Hofmeister, Marlene V.; Vinggaard, Anne Marie

    2007-01-01

    Background An array of environmental compounds is known to possess endocrine disruption (ED) potentials. Bisphenol A (BPA) and bisphenol A dimethacrylate (BPA-DM) are monomers used to a high extent in the plastic industry and as dental sealants. Alkylphenols such as 4-n-nonylphenol (nNP) and 4-n-octylphenol (nOP) are widely used as surfactants. Objectives We investigated the effect in vitro of these four compounds on four key cell mechanisms including transactivation of a) the human estrogen receptor (ER), b) the human androgen receptor (AR), c) the aryl hydrocarbon receptor (AhR), and d) aromatase activity. Results All four compounds inhibited aromatase activity and were agonists and antagonists of ER and AR, respectively. nNP increased AhR activity concentration-dependently and further increased the 2,3,7,8-tetrachlorodibenzo-p-dioxin AhR action. nOP caused dual responses with a weak increased and a decreased AhR activity at lower (10−8 M) and higher concentrations (10−5–10−4 M), respectively. AhR activity was inhibited with BPA (10−5–10−4 M) and weakly increased with BPA-DM (10−5 M), respectively. nNP showed the highest relative potency (REP) compared with the respective controls in the ER, AhR, and aromatase assays, whereas similar REP was observed for the four chemicals in the AR assay. Conclusion Our in vitro data clearly indicate that the four industrial compounds have ED potentials and that the effects can be mediated via several cellular pathways, including the two sex steroid hormone receptors (ER and AR), aromatase activity converting testosterone to estrogen, and AhR; AhR is involved in syntheses of steroids and metabolism of steroids and xenobiotic compounds. PMID:18174953

  12. 21 CFR 573.225 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.225 1,3-Butylene glycol. The food additive 1,3-butylene glycol (1,3-butanediol) may... 21 Food and Drugs 6 2011-04-01 2011-04-01 false 1,3-Butylene glycol. 573.225 Section 573.225...

  13. 21 CFR 573.225 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.225 1,3-Butylene glycol. The food additive 1,3-butylene glycol (1,3-butanediol) may... 21 Food and Drugs 6 2013-04-01 2013-04-01 false 1,3-Butylene glycol. 573.225 Section 573.225...

  14. 21 CFR 573.225 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.225 1,3-Butylene glycol. The food additive 1,3-butylene glycol (1,3-butanediol) may... 21 Food and Drugs 6 2010-04-01 2010-04-01 false 1,3-Butylene glycol. 573.225 Section 573.225...

  15. 21 CFR 573.225 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.225 1,3-Butylene glycol. The food additive 1,3-butylene glycol (1,3-butanediol) may... 21 Food and Drugs 6 2014-04-01 2014-04-01 false 1,3-Butylene glycol. 573.225 Section 573.225...

  16. 21 CFR 573.225 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.225 1,3-Butylene glycol. The food additive 1,3-butylene glycol (1,3-butanediol) may... 21 Food and Drugs 6 2012-04-01 2012-04-01 false 1,3-Butylene glycol. 573.225 Section 573.225...

  17. Diethylene glycol poisoning in Nigerian children.

    PubMed

    Okuonghae, H O; Ighogboja, I S; Lawson, J O; Nwana, E J

    1992-01-01

    Between June and September 1990, 47 children died at Jos University Teaching Hospital, Nigeria from ingestion of paracetamol syrup adulterated with diethylene glycol. Most of the children presented with anuria, fever, vomiting, diarrhoea and convulsions. Signs on admission were tachycardia, acidotic breathing, pallor, oedema and hepatomegaly. Laboratory findings included hyperkalaemia, acidosis, elevated creatinine level and hypoglycaemia. Management consisted of correction of dehydration and acidosis plus administration of antibiotics when indicated. None of the children had dialysis. All died within 2 weeks of admission. Proper government supervision of pharmaceutical companies and their agencies is urgently needed in order to prevent any future occurrence of such tragic deaths. PMID:1280035

  18. Characterization of Polyethylene Glycol Modified Hemoglobins

    NASA Astrophysics Data System (ADS)

    Salazar, Gil; Barr, James; Morgan, Wayne; Ma, Li

    2011-03-01

    Polyethylene glycol modified hemoglobins (PEGHbs) was characterized by liquid chromatography and fluorescence methods. We prepared four samples of two different molecular weight PEG, 5KDa and 20KDa, modified bovine and human hemoglobin. We studied the oxygen affinities, stabilities, and peroxidase activities of PEGHbs. We have related oxygen affinities with different degrees of modifications. The data showed that the modification on the beta subunits was less stable than that of the alpha subunits on the human Hb based samples especially. We also compared peroxidase activities among different modified PEGHbs.

  19. Marangoni effects in aqueous polypropylene glycol foams.

    PubMed

    Tan, Su Nee; Fornasiero, Daniel; Sedev, Rossen; Ralston, John

    2005-06-15

    The foam behavior of three polypropylene glycols covering the molecular weight range between 192 and 725 g/mol has been examined. Static and dynamic surface tension data, as well as bubble size distribution and retention time in the foam, were incorporated into a simple model of foam stability. The latter clearly indicates that surface tension differences between the plateau border and lamellar region adjacent to the bubble surface are the dominant factor in controlling foamability, causing liquid flow in the direction opposite to liquid drainage, a process termed the Marangoni effect.

  20. Microfluidic approaches for the fabrication of gradient crosslinked networks based on poly(ethylene glycol) and hyperbranched polymers for manipulation of cell interactions

    PubMed Central

    Pedron, S; Peinado, C; Bosch, P; Benton, J A; Anseth, K S

    2011-01-01

    High-throughput methods allow rapid examination of parameter space to characterize materials and develop new polymeric formulations for biomaterials applications. One limitation is the difficulty of preparing libraries and performing high-throughput screening with conventional instrumentation and sample preparation. Here, we describe the fabrication of substrate materials with controlled gradients in composition by a rapid method of micromixing followed by a photopolymerization reaction. Specifically, poly(ethylene glycol) dimethacrylate was copolymerized with a hyperbranched multimethacrylate (P1000MA or H30MA) in a gradient manner. The extent of methacrylate conversion and the final network composition were determined by near-infrared spectroscopy, and mechanical properties were measured by nanoindentation. A relationship was observed between the elastic modulus and network crosslinking density. Roughness and hydrophilicity were increased on surfaces with a higher concentration of P1000MA. These results likely relate to a phase segregation process of the hyperbranched macromer that occurs during the photopolymerization reaction. On the other hand, the decrease in the final conversion in H30MA polymerization reactions was attributed to the lower termination rate as a consequence of the softening of the network. Valvular interstitial cell attachment was evaluated on these gradient substrates as a demonstration of studying cell morphology as a function of the local substrate properties. Data revealed that the presence of P1000MA affects cell–material interaction with a higher number of adhered cells and more cell spreading on gradient regions with a higher content of the multifunctional crosslinker. PMID:21105168

  1. The effect of glycerol, propylene glycol and polyethylene glycol 400 on the partition coefficient of benzophenone-3 (oxybenzone).

    PubMed

    Mbah, C J

    2007-01-01

    Sunscreen products are widely used to protect the skin from sun-related deleterious effects. The objective of the study was to investigate the potential effect of glycerol, propylene glycol and polyethylene glycol 400 on dermal absorption of oxybenzone by studying their effects on its partition coefficient. The partition coefficient was evaluated in a chloroform-water system at room temperature. It was found that glycerol and propylene glycol decreased the partition coefficient of oxybenzone, while an increase in partition coefficient was observed with polyethylene glycol 400. The findings suggest that polyethylene glycol 400 in contrast to glycerol and propylene glycol has the potential of increasing the vehicle-skin partition coefficient of oxybenzone when cosmetic products containing such an UV absorber are topically applied to the skin. PMID:17294811

  2. Microwave-assisted Functionalization of Poly(ethylene glycol) and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation

    PubMed Central

    Van Hove, Amy H.; Wilson, Brandon D.; Benoit, Danielle S. W.

    2013-01-01

    One of the main benefits to using poly(ethylene glycol) (PEG) macromers in hydrogel formation is synthetic versatility. The ability to draw from a large variety of PEG molecular weights and configurations (arm number, arm length, and branching pattern) affords researchers tight control over resulting hydrogel structures and properties, including Young’s modulus and mesh size. This video will illustrate a rapid, efficient, solvent-free, microwave-assisted method to methacrylate PEG precursors into poly(ethylene glycol) dimethacrylate (PEGDM). This synthetic method provides much-needed starting materials for applications in drug delivery and regenerative medicine. The demonstrated method is superior to traditional methacrylation methods as it is significantly faster and simpler, as well as more economical and environmentally friendly, using smaller amounts of reagents and solvents. We will also demonstrate an adaptation of this technique for on-resin methacrylamide functionalization of peptides. This on-resin method allows the N-terminus of peptides to be functionalized with methacrylamide groups prior to deprotection and cleavage from resin. This allows for selective addition of methacrylamide groups to the N-termini of the peptides while amino acids with reactive side groups (e.g. primary amine of lysine, primary alcohol of serine, secondary alcohols of threonine, and phenol of tyrosine) remain protected, preventing functionalization at multiple sites. This article will detail common analytical methods (proton Nuclear Magnetic Resonance spectroscopy (;H-NMR) and Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-ToF)) to assess the efficiency of the functionalizations. Common pitfalls and suggested troubleshooting methods will be addressed, as will modifications of the technique which can be used to further tune macromer functionality and resulting hydrogel physical and chemical properties. Use of synthesized products for the

  3. Characterization of tetraethylene glycol passivated iron nanoparticles

    NASA Astrophysics Data System (ADS)

    Nunes, Eloiza da Silva; Viali, Wesley Renato; da Silva, Sebastião William; Coaquira, José Antonio Huamaní; Garg, Vijayendra Kumar; de Oliveira, Aderbal Carlos; Morais, Paulo César; Jafelicci Júnior, Miguel

    2014-10-01

    The present study describes the synthesis and characterization of iron@iron oxide nanoparticles produced by passivation of metallic iron in tetraethylene glycol media. Structural and chemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Mössbauer spectroscopy. Pomegranate-like core@shell nanoparticulate material in the size range of 90-120 nm was obtained. According to quantitative phase analysis using Rietveld structure refinement the synthesized iron oxide was identified as magnetite (Fe3O4) whereas the iron to magnetite mass fractions was found to be 47:53. These findings are in good agreement with the data obtained from Mössbauer and thermal gravimetric analysis (TGA). The XPS data revealed the presence of a surface organic layer with higher hydrocarbon content, possibly due to the tetraethylene glycol thermal degradation correlated with iron oxidation. The room-temperature (300 K) saturation magnetization measured for the as-synthesized iron and for the iron-iron oxide were 145 emu g-1 and 131 emu g-1, respectively. The measured saturation magnetizations are in good agreement with data obtained from TEM, XRD and Mössbauer spectroscopy.

  4. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  6. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  7. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  8. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic). 721.10038 Section 721.10038... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  9. Millimetre wave rotational spectrum of glycolic acid

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Pszczółkowski, Lech; Białkowska-Jaworska, Ewa; Charnley, Steven B.

    2016-03-01

    The pure rotational spectrum of glycolic acid, CH2OHCOOH, was studied in the region 115-318 GHz. For the most stable SSC conformer, transitions in all vibrational states up to 400 cm-1 have been measured and their analysis is reported. The data sets for the ground state, v21 = 1 , and v21 = 2 have been considerably extended. Immediately higher in vibrational energy are two triads of interacting vibrational states and their rotational transitions have been assigned and successfully fitted with coupled Hamiltonians accounting for Fermi and Coriolis resonances. The derived energy level spacings establish that the vibrational frequency of the ν21 mode is close to 100 cm-1. The existence of the less stable AAT conformer in the near 50 °C sample used in our experiment was also confirmed and additional transitions have been measured.

  10. Ethylene glycol: properties, synthesis, and applications.

    PubMed

    Yue, Hairong; Zhao, Yujun; Ma, Xinbin; Gong, Jinlong

    2012-06-01

    Ethylene glycol (EG) is an important organic compound and chemical intermediate used in a large number of industrial processes (e.g. energy, plastics, automobiles, and chemicals). Indeed, owing to its unique properties and versatile commercial applications, a variety of chemical systems (e.g., catalytic and non-catalytic) have been explored for the synthesis of EG, particularly via reaction processes derived from fossil fuels (e.g., petroleum, natural gas, and coal) and biomass-based resources. This critical review describes a broad spectrum of properties of EG and significant advances in the prevalent synthesis and applications of EG, with emphases on the catalytic reactivity and reaction mechanisms of the main synthetic methodologies and applied strategies. We also provide an overview regarding the challenges and opportunities for future research associated with EG. PMID:22488259

  11. Diethylene glycol poisoning in Gurgaon, India, 1998.

    PubMed Central

    Singh, J.; Dutta, A. K.; Khare, S.; Dubey, N. K.; Harit, A. K.; Jain, N. K.; Wadhwa, T. C.; Gupta, S. R.; Dhariwal, A. C.; Jain, D. C.; Bhatia, R.; Sokhey, J.

    2001-01-01

    OBJECTIVE: To discover the cause of acute renal failure in 36 children aged 2 months to 6 years who were admitted to two hospitals in Delhi between 1 April and 9 June 1998. METHODS: Data were collected from hospital records, parents and doctors of the patients, and district health officials. Further information was obtained from house visits and community surveys; blood and stool samples were collected from other ill children, healthy family members and community contacts. Samples of drinking-water and water from a tube-well were tested for coliform organisms. FINDINGS: Most of the children (26/36) were from the Gurgaon district in Haryana or had visited Gurgaon town for treatment of a minor illness. Acute renal failure developed after an episode of acute febrile illness with or without watery diarrhoea or mild respiratory symptoms for which the children had been treated with unknown medicines by private medical practitioners. On admission to hospital the children were not dehydrated. Median blood urea concentration was 150 mg/dl (range 79-311 mg/dl) and median serum creatinine concentration was 5.6 mg/dl (range 2.6-10.8 mg/dl). Kidney biopsy showed acute tubular necrosis. Thirty-three children were known to have died despite being treated with peritoneal dialysis and supportive therapy. CONCLUSION: Cough expectorant manufactured by a company in Gurgaon was found to be contaminated with diethylene glycol (17.5% v/v), but a sample of acetaminophen manufactured by the same company tested negative for contamination when gas-liquid chromatography was used. Thus, poisoning with diethylene glycol seems to be the cause of acute renal failure in these children. PMID:11242827

  12. Membrane permeability of the human granulocyte to water, dimethyl sulfoxide, glycerol, propylene glycol and ethylene glycol

    PubMed Central

    Vian, Alex M.; Higgins, Adam Z.

    2015-01-01

    Granulocytes are currently transfused as soon as possible after collection because they rapidly deteriorate after being removed from the body. This short shelf life complicates the logistics of granulocyte collection, banking and safety testing. Cryopreservation has the potential to significantly increase shelf life; however, cryopreservation of granulocytes has proven to be difficult. In this study, we investigate the membrane permeability properties of human granulocytes, with the ultimate goal of using membrane transport modeling to facilitate development of improved cryopreservation methods. We first measured the equilibrium volume of human granulocytes in a range of hypo- and hypertonic solutions and fit the resulting data using a Boyle-van't Hoff model. This yielded an isotonic cell volume of 378 μm3 and an osmotically inactive volume of 165 μm3. To determine the permeability of the granulocyte membrane to water and cryoprotectant (CPA), cells were injected into well-mixed CPA solution while collecting volume measurements using a Coulter Counter. These experiments were performed at temperatures ranging from 4 to 37 °C for exposure to dimethyl sulfoxide, glycerol, ethylene glycol and propylene glycol. The best-fit water permeability was similar in the presence of all of the CPAs, with an average value at 21 °C of 0.18 μm atm−1 min−1. The activation energy for water transport ranged from 41 to 61 kJ/mol. The CPA permeability at 21 °C was 6.4, 1.0, 8.4 and 4.0 μm/min for dimethyl sulfoxide, glycerol, ethylene glycol and propylene glycol, respectively, and the activation energy for CPA transport ranged between 59 and 68 kJ/mol. PMID:24269528

  13. Membrane permeability of the human granulocyte to water, dimethyl sulfoxide, glycerol, propylene glycol and ethylene glycol.

    PubMed

    Vian, Alex M; Higgins, Adam Z

    2014-02-01

    Granulocytes are currently transfused as soon as possible after collection because they rapidly deteriorate after being removed from the body. This short shelf life complicates the logistics of granulocyte collection, banking, and safety testing. Cryopreservation has the potential to significantly increase shelf life; however, cryopreservation of granulocytes has proven to be difficult. In this study, we investigate the membrane permeability properties of human granulocytes, with the ultimate goal of using membrane transport modeling to facilitate development of improved cryopreservation methods. We first measured the equilibrium volume of human granulocytes in a range of hypo- and hypertonic solutions and fit the resulting data using a Boyle-van't Hoff model. This yielded an isotonic cell volume of 378 μm(3) and an osmotically inactive volume of 165 μm(3). To determine the permeability of the granulocyte membrane to water and cryoprotectant (CPA), cells were injected into well-mixed CPA solution while collecting volume measurements using a Coulter Counter. These experiments were performed at temperatures ranging from 4 to 37°C for exposure to dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol. The best-fit water permeability was similar in the presence of all of the CPAs, with an average value at 21°C of 0.18 μmatm(-1)min(-1). The activation energy for water transport ranged from 41 to 61 kJ/mol. The CPA permeability at 21°C was 6.4, 1.0, 8.4, and 4.0 μm/min for dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol, respectively, and the activation energy for CPA transport ranged between 59 and 68 kJ/mol. PMID:24269528

  14. Thermal desorption characterisation of molecularly imprinted polymers. Part I: A novel study using direct-probe GC-MS analysis.

    PubMed

    Cummins, Wayne; Duggan, Patrick; McLoughlin, Peter

    2008-06-01

    A novel thermal desorption technique using a direct-probe device (Chromatoprobe) attached to a gas chromatograph-mass spectrometer is presented for the thermal pretreatment, characterisation and analysis of molecularly imprinted polymers. The technique is demonstrated as effective for the removal of volatile materials, including template and unreacted monomers, from methacrylic acid-ethylene glycol dimethacrylate copolymers imprinted with 2-aminopyridine. Mass spectrometry is a powerful technique for polymer bleed characterisation. Thermal desorption studies on reloaded template and related compounds are reported as a means of assessing polymer morphology, specific binding by imprinted polymers compared with reference non-imprinted polymers and selective binding by an imprinted polymer for its template. Calibration studies on the thermal desorption technique using an internal standard are presented with R(2) > 0.999. The technique provides a novel method for assessment of polymer thermal stability, composition and morphology.

  15. Degradation of ethylene glycol using Fenton's reagent and UV.

    PubMed

    McGinnis, B D; Adams, V D; Middlebrooks, E J

    2001-10-01

    Oxidation of ethylene glycol in aqueous solutions was found to occur with the addition of Fenton's reagent with further conversion observed upon UV irradiation. The pH range studied was 2.5-9.0 with initial H2O2 concentrations ranging from 100 to 1000 mg/l. Application of this method to airport storm-water could potentially result in reduction of chemical oxygen demand by conversion of ethylene glycol to oxalic and formic acids. Although the amount of H2O2 added follows the amount of ethylene glycol degraded, smaller H2O2 doses were associated with increases in the ratio of ethylene glycol removed per unit H2O2 added indicating the potential of pulsed doses or constant H2O2 feed systems. Ethylene glycol removal was enhanced by exposure to UV light after treatment with Fenton's reagent, with rates dependent on initial H2O2 concentration. In addition to ethylene glycol, the principle products of this reaction, oxalic and formic acids, have been shown to be mineralized in other HO generating systems presenting the potential for ethylene glycol mineralization in this system with increased HO* production.

  16. Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations.

    PubMed

    Peace, Michelle R; Baird, Tyson R; Smith, Nathaniel; Wolf, Carl E; Poklis, Justin L; Poklis, Alphonse

    2016-07-01

    Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography-tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography-mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations.

  17. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect

    Pickenheim, B.; Bibler, N.

    2010-06-08

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be

  18. Magnetic fluids stabilized by polypropylene glycol

    NASA Astrophysics Data System (ADS)

    Lebedev, A. V.; Lysenko, S. N.

    2011-05-01

    A series of samples of magnetic fluids stabilized with low-molecular weight polypropylene glycol (PPG) of different molecular masses were synthesized. The use of PPG allowed the maximum extension of the carrier fluid range to include ethyl- and butyl-acetate, ethanol, butanol, acetone, carbon tetrachloride, toluene, kerosene and PPG itself. Magnetic and rheological properties of the samples were investigated. Based on the results of investigation it has been concluded that magnetic nanoparticles are covered by a monolayer of surfactant molecules. At low temperatures the propanol-based sample preserves fluidity up to -115 °C. Measurement of critical temperatures of other base fluids showed that alcohols are the best carrier medium. Coagulation stability of the ethanol-based ferrocolloid with respect to water and kerosene was explored. It has been found that kerosene, whose fraction by weight exceeds 22.5%, does not mix with the colloid. This effect can be used to produce magneto-controllable extractors of ethyl alcohol. Under the action of water the colloid coagulates, which allows one to substitute the carrier fluid and to separate the colloid into fractions.

  19. Redox-labelled poly(ethylene glycol) used as a diffusion probe in poly(ethylene glycol) melts

    SciTech Connect

    Haas, O.; Velasquez, C.; Porat, Z.

    1995-12-01

    Ferrocene labelled monomethyl poly(ethylene glycol) MPEG with molecular weights of 1900 and 750 was prepared and used as an electrochemical diffusion probe in poly(ethylene glycol) melts. Cyclic voltammetry and chronoamperometry were used in connection with microdisk electrodes to measure the diffusion coefficient of redox tagged molecules using melted poly(ethylene glycol) as a solvent. The molecular weight of the solvent polymer was 750, 2000 and 20000. Results from the temperature dependency of the diffusion process and of the viscosity and conductivity of the polymer electrolyte are presented and discussed.

  20. Green polymer chemistry VIII: synthesis of halo-ester-functionalized poly(ethylene glycol)s via enzymatic catalysis.

    PubMed

    Castano, Marcela; Seo, Kwang Su; Kim, Eun Hye; Becker, Matthew L; Puskas, Judit E

    2013-09-01

    Halo-ester-functionalized poly(ethylene glycol)s (PEGs) are successfully prepared by the transesterification of alkyl halo-esters with PEGs using Candida antarctica lipase B (CALB) as a biocatalyst under the solventless conditions. Transesterifications of chlorine, bromine, and iodine esters with tetraethylene glycol monobenzyl ether (BzTEG) are quantitative in less than 2.5 h. The transesterification of halo-esters with PEGs are complete in 4 h. (1) H and (13) C NMR spectroscopy with MALDI-ToF and ESI mass spectrometry confirm the structure and purity of the products. This method provides a convenient and "green" process to effectively produce halo-ester PEGs.

  1. Why does glycol inhibit CO{sub 2} corrosion?

    SciTech Connect

    Gulbrandsen, E.; Morad, J.H.

    1998-12-31

    CO{sub 2} corrosion of carbon steel and its inhibition in mixtures of water and ethylene glycol (MEG) or diethylene glycol (DEG) has been studied at 1 bar CO{sub 2}, 25 C, pH 5 under natural convection conditions. Corrosion rates predicted by the glycol correction factor of DeWaard et al. were in mutual agreement with the experimental results. Analysis of the experimental results shows that the corrosion inhibitor effect of MEG and DEG can be correlated to changes in solution properties with increasing MEG or DEG concentration, such as decreased CO{sub 2} volubility, decreased CO{sub 2} diffusivity/increased solution viscosity, decreased water activity and decreased solution polarity. Also described is an impurity related corrosion inhibition that can be very efficient, and possible ways to improve the inhibitor effect of glycol solutions by adding small amounts of inhibitor compounds.

  2. Measurement of diffusion coefficient of propylene glycol in skin tissue

    NASA Astrophysics Data System (ADS)

    Genin, Vadim D.; Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.

    2015-03-01

    Optical clearing of the rat skin under the action of propylene glycol was studied ex vivo. It was found that collimated transmittance of skin samples increased, whereas weight and thickness of the samples decreased during propylene glycol penetration in skin tissue. A mechanism of the optical clearing under the action of propylene glycol is discussed. Diffusion coefficient of propylene glycol in skin tissue ex vivo has been estimated as (1.35±0.95)×10-7 cm2/s with the taking into account of kinetics of both weight and thickness of skin samples. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  3. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect

    Lambert, D.; Pickenheim, B.; Hay, M.

    2011-06-20

    The Defense Waste Processing Facility (DWPF) is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and

  4. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  5. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  6. Safety assessment of 1,2-glycols as used in cosmetics.

    PubMed

    Johnson, Wilbur; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2012-01-01

    Caprylyl glycol and related 1,2-glycols are used mostly as skin and hair conditioning agents and viscosity agents in cosmetic products, and caprylyl glycol and pentylene glycol also function as cosmetic preservatives. The Cosmetic Ingredient Review (CIR) Expert Panel noted that, while these ingredients are dermally absorbed, modeling data predicted decreased skin penetration of longer chain 1,2-glycols. Because the negative oral toxicity data on shorter chain 1,2-glycols and genotoxicity data support the safety of the 1,2-glycols reviewed in this safety assessment, the Panel concluded that these ingredients are safe in the present practices of use and concentration described in this safety assessment.

  7. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

    NASA Technical Reports Server (NTRS)

    Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

    2003-01-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

  8. Material compatibility evaluation for DWPF nitric-glycolic acid-literature review

    SciTech Connect

    Mickalonis, J.; Skidmore, E.

    2013-06-01

    Glycolic acid is being evaluated as an alternative for formic and nitric acid in the DWPF flowsheet. Demonstration testing and modeling for this new flowsheet has shown that glycolic acid and glycolate has a potential to remain in certain streams generated during the production of the nuclear waste glass. A literature review was conducted to assess the impact of glycolic acid on the corrosion of the materials of construction for the DWPF facility as well as facilities downstream which may have residual glycolic acid and glycolates present. The literature data was limited to solutions containing principally glycolic acid.

  9. GLYCOLIC-FORMIC ACID FLOWSHEET FINAL REPORT FOR DOWNSELECTION DECISION

    SciTech Connect

    Lambert, D.; Pickenheim, B.; Stone, M.; Newell, J.; Best, D.

    2011-03-10

    Flowsheet testing was performed to develop the nitric-glycolic-formic acid flowsheet (referred to as the glycolic-formic flowsheet throughout the rest of the report) as an alternative to the nitric/formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be removed in the Sludge Receipt and Adjustment Tank (SRAT) with minimal hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Forty-six runs were performed in total, including the baseline run and the melter feed preparation runs. Significant results are summarized. The baseline nitric/formic flowsheet run, using the SB6 simulant produced by Harrell was extremely difficult to process successfully under existing DWPF acceptance criteria with this simulant at the HM levels of noble metals. While nitrite was destroyed and mercury was removed to near the DWPF limit, the rheology of the SRAT and SME products were well above design basis and hydrogen generation far exceeded the DWPF SRAT limit. In addition, mixing during the SME cycle was very poor. In this sense, the nitric/glycolic/formic acid flowsheet represents a significant upgrade over the current flowsheet. Mercury was successfully removed with almost no hydrogen generation and the SRAT and SME products yield stresses were within process limits or previously processed ranges. The glycolic-formic flowsheet has a very wide processing window. Testing was completed from 100% to 200% of acid stoichiometry and using a glycolic-formic mixture from 40% to 100% glycolic acid. The testing met all processing requirements throughout these processing windows. This should allow processing at an acid stoichiometry of 100% and a glycolic-formic mixture of 80% glycolic acid with minimal hydrogen generation. It should also allow processing endpoints in the SRAT and SME at significantly higher

  10. Partitioning of differently sized poly(ethylene glycol)s into OmpF porin.

    PubMed Central

    Rostovtseva, Tatiana K; Nestorovich, Ekaterina M; Bezrukov, Sergey M

    2002-01-01

    To understand the physics of polymer equilibrium and dynamics in the confines of ion channel pores, we study partitioning of poly(ethylene glycol)s (PEGs) of different molecular weights into the bacterial porin, OmpF. Thermodynamic and kinetic parameters of partitioning are deduced from the effects of polymer addition on ion currents through single OmpF channels reconstituted into planar lipid bilayer membranes. The equilibrium partition coefficient is inferred from the average reduction of channel conductance in the presence of PEG; rates of polymer exchange between the pore and the bulk are estimated from PEG-induced conductance noise. Partition coefficient as a function of polymer weight is best fitted by a "compressed exponential" with the compression factor of 1.65. This finding demonstrates that PEG partitioning into the OmpF channel pore has sharper dependence on polymer molecular weight than predictions of hard-sphere, random-flight, or scaling models. A 1360-Da polymer separates regimes of partitioning and exclusion. Comparison of its characteristic size with the size of a 2200-Da polymer previously found to separate these regimes for the alpha-toxin shows good agreement with the x-ray structural data for these channels. The PEG-induced conductance noise is compatible with the polymer mobility reduced inside the OmpF pore by an order of magnitude relatively to its value in bulk solution. PMID:11751305

  11. Polyethylene glycol-coated biocompatible surfaces.

    PubMed

    Alcantar, N A; Aydil, E S; Israelachvili, J N

    2000-09-01

    Surfaces covered with polyethylene glycol (PEG; HO-(CH(2)-CH(2)-O)(n)-H) have been shown to be biocompatible because PEG's properties yield nonimmunogenicity, nonantigenicity, and protein rejection. To produce a biocompatible surface coating, we have developed a method for grafting PEG onto activated silica films. We first deposited an amorphous silica film by plasma-enhanced chemical vapor deposition from SiH(4) and O(2) gases, which provided the flexibility to coat diverse materials with different chemistries and shapes. The silica films were activated by exposure to water plasma, increasing the number of silanol groups (Si-OH) on their surface. The surface silanol groups were then chemically reacted with the hydroxyl end of PEG to form an ester bond, Si-O-C, and to cover the surface with PEG. The surface reactions were monitored using attenuated total reflection Fourier transform infrared spectroscopy. The vibrational absorption bands of the C-O and -CH(2) bonds increased with time and saturated, indicating that PEG was adsorbed to saturation coverage on the surface. Simultaneously, the Si-OH absorption band decreased, showing that the surface silanols reacted with PEG and were depleted. The PEG-covered surfaces were physically characterized by atomic force microscopy, Auger electron spectroscopy, ellipsometry, and contact angle measurements. These characterization techniques provided additional evidence for the existence of chemically bonded PEG on the surfaces. Efficacy of protein rejection on PEG-covered surfaces was studied through measurements of the fluorescence intensity of Texas red-labeled bovine serum albumin brought in contact with such surfaces in solution. Significantly less protein adsorption was observed on surfaces covered with PEG compared to uncovered surfaces. PMID:10880075

  12. Mutagenicity testing of diethylene glycol monobutyl ether.

    PubMed Central

    Thompson, E D; Coppinger, W J; Valencia, R; Iavicoli, J

    1984-01-01

    The mutagenic potential of diethylene glycol monobutyl ether (diEGBE) was examined with a Tier I battery of in vitro assays followed by a Tier II in vivo Drosophila sex-linked recessive lethal assay. The in vitro battery consisted of: the Salmonella mutagenicity test, the L5178Y mouse lymphoma test, a cytogenetics assay using Chinese hamster ovary cells and the unscheduled DNA synthesis (UDS) assay in rat hepatocytes. Results of the Salmonella mutagenicity test, the cytogenetics test, and the rat hepatocyte assay were negative at concentrations up to 20 microL/plate, 7.92 microL/mL, and 4.4 microL/mL, respectively. Toxicity was clearly demonstrated at all high doses. A weak, but dose-related increase in the mutation frequency (4-fold increase over the solvent control at 5.6 microL/mL with 12% survival) was obtained in the L5178Y lymphoma test in the absence of metabolic activation. Results of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay results were assessed by performing the Tier II sex-linked recessive lethal assay in Drosophila in which the target tissue is maturing germinal cells. Both feeding (11,000 ppm for 3 days) and injection (0.3 microL of approximately 14,000 ppm solution) routes of administration were employed in the Drosophila assay. Approximately 11,000 individual crosses with an equal number of negative controls were performed for each route of administration. diEGBE produced no increase in recessive lethals under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6389113

  13. Fast determination of ethylene glycol, 1,2-propylene glycol and glycolic acid in blood serum and urine for emergency and clinical toxicology by GC-FID.

    PubMed

    Hložek, Tomáš; Bursová, Miroslava; Čabalaa, Radomír

    2014-12-01

    A simple, cost effective, and fast gas chromatography method with flame ionization detection (GC-FID) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. This new method employs a relatively less used class of derivatization agents - alkyl chloroformates, allowing the efficient and rapid derivatization of carboxylic acids within seconds while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. To avoid possible interference from naturally occurring endogenous acids and quantitation errors 3-(4-chlorophenyl) propionic acid was chosen as an internal standard. The significant parameters of the derivatization have been found using chemometric procedures and these parameters were optimized using the face-centered central composite design. The calibration dependence of the method was proved to be quadratic in the range of 50-5000 mg mL(-1), with adequate accuracy (92.4-108.7%) and precision (9.4%). The method was successfully applied to quantify the selected compounds in serum of patients from emergency units.

  14. The Verification of a Method for Detecting and Quantifying Diethylene Glycol, Triethylene Glycol, Tetraethylene Glycol, 2-Butoxyethanol and 2-Methoxyethanolin in Ground and Surface Waters

    EPA Science Inventory

    This verification study was a special project designed to determine the efficacy of a draft standard operating procedure (SOP) developed by US EPA Region 3 for the determination of selected glycols in drinking waters that may have been impacted by active unconventional oil and ga...

  15. Hydration of polyethylene glycol-grafted liposomes.

    PubMed Central

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

    1998-01-01

    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

  16. Synthesis and characterization of hydrolytically degradable copolyester biomaterials based on glycolic acid, sebacic acid and ethylene glycol.

    PubMed

    Simitzis, J; Soulis, S; Triantou, D; Zoumpoulakis, L; Zotali, P

    2011-12-01

    Copolyesters of glycolic acid (G) combined with sebacic acid (S) and ethylene glycol were synthesized in different molar ratios (G: 0-100% and S: 100-0%) and their hydrolytic degradation was studied and correlated with their structures. Based on the FTIR spectra of the homopolyesters and copolyesters and the normalized peak intensity of the I(2918), I(2848) and I(1087) for the corresponding wavenumbers, it is concluded that the I(2918) and the I(2848) are in accordance with the mean number degree of polymerization of ethylene sebacate units and the I(1087) is in accordance with the mean number degree of polymerization of glycolate units. Based on the XRD diffractograms, poly(ethylene sebacate) and poly(glycolic acid) belong to the monoclinic and the orthorhombic crystal system, respectively and both have higher crystallinity than the copolyesters. The experimental data of the hydrolytic degradation were fitted with exponential rise to maximum type functions using two-parameter model and four-parameter model. Three regions can been distinguished for the hydrolytic degradation by decreasing the molar feed ratio of sebacic acid, which are correlated with the changes of crystallinity. Two copolyesters are proposed: first the copolyester with high amount of glycolate units (S10G90) having higher hydrolytic degradation than G100 and second the copolyester with equal amount of glycolate and ethylene sebacate units (S50G50), having lower hydrolytic degradation than G100. These hydrolytically degradable copolyesters are soluble in common organic solvents, opposite to poly(glycolic acid) and could have perspectives for biomedical applications.

  17. Pulmonary surfactant adsorption is increased by hyaluronan or polyethylene glycol.

    PubMed

    Taeusch, H William; Dybbro, Eric; Lu, Karen W

    2008-04-01

    In acute lung injuries, inactivating agents may interfere with transfer (adsorption) of pulmonary surfactants to the interface between air and the aqueous layer that coats the interior of alveoli. Some ionic and nonionic polymers reduce surfactant inactivation in vitro and in vivo. In this study, we tested directly whether an ionic polymer, hyaluronan, or a nonionic polymer, polyethylene glycol, enhanced adsorption of a surfactant used clinically. We used three different methods of measuring adsorption in vitro: a modified pulsating bubble surfactometer; a King/Clements device; and a spreading trough. In addition we measured the effects of both polymers on surfactant turbidity, using this assay as a nonspecific index of aggregation. We found that both hyaluronan and polyethylene glycol significantly increased the rate and degree of surfactant material adsorbed to the surface in all three assays. Hyaluronan was effective in lower concentrations (20-fold) than polyethylene glycol and, unlike polyethylene glycol, hyaluronan did not increase apparent aggregation of surfactant. Surfactant adsorption in the presence of serum was also enhanced by both polymers regardless of whether hyaluronan or polyethylene glycol was included with serum in the subphase or added to the surfactant applied to the surface. Therefore, endogenous polymers in the alveolar subphase, or exogenous polymers added to surfactant used as therapy, may both be important for reducing inactivation of surfactant that occurs with various lung injuries.

  18. The pathway of glycollate utilization in Chlorella pyrenoidosa.

    PubMed

    Lord, J M; Merrett, M J

    1970-05-01

    1. Exogenous glycollate was rapidly metabolized in both the light and the dark by photoautotrophically grown Chlorella pyrenoidosa. 2. The incorporation of (14)C from [1-(14)C]glycollate by these cells was inhibited by the tricarboxylic acid-cycle inhibitors monofluoroacetate, diethylmalonate and arsenite, and also by alpha-hydroxypyrid-2-ylmethanesulphonate and isonicotinylhydrazine. 3. Short-term kinetic experiments showed over 80% of the total (14)C present in the soluble fraction from the cells to be in glycine and serine after 10s. This percentage decreased with time whereas the percentage radioactivity in glycerate increased for up to 30s then remained steady. The percentage of the total radioactivity present in citrate increased over the experimental period. Malate was the only other tricarboxylic acid-cycle intermediate to become labelled. 4. The kinetic and inhibitor experiments supported the following pathway of glycollate incorporation: glycollate --> glyoxylate --> glycine --> serine --> hydroxypyruvate --> glycerate --> 3-phosphoglycerate --> 2-phosphoglycerate --> phosphoenolpyruvate --> pyruvate --> acetyl-CoA. 5. The specific activities of the enzymes catalysing this metabolic sequence in cell-free extracts were great enough to account for the observed rate of glycollate metabolism of 0.25mumol/h per mg dry wt. of cells in the light.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  20. Green polymer chemistry VIII: synthesis of halo-ester-functionalized poly(ethylene glycol)s via enzymatic catalysis.

    PubMed

    Castano, Marcela; Seo, Kwang Su; Kim, Eun Hye; Becker, Matthew L; Puskas, Judit E

    2013-09-01

    Halo-ester-functionalized poly(ethylene glycol)s (PEGs) are successfully prepared by the transesterification of alkyl halo-esters with PEGs using Candida antarctica lipase B (CALB) as a biocatalyst under the solventless conditions. Transesterifications of chlorine, bromine, and iodine esters with tetraethylene glycol monobenzyl ether (BzTEG) are quantitative in less than 2.5 h. The transesterification of halo-esters with PEGs are complete in 4 h. (1) H and (13) C NMR spectroscopy with MALDI-ToF and ESI mass spectrometry confirm the structure and purity of the products. This method provides a convenient and "green" process to effectively produce halo-ester PEGs. PMID:23877930

  1. Electrochemical measurements of diffusion coefficients of redox-labeled poly(ethylene glycol) dissolved in poly(ethylene glycol) melts

    SciTech Connect

    Haas, O.; Velazquez, C.S.; Porat, Z.; Murray, R.W.

    1995-10-12

    Ferrocene labeled monomethoxy-poly(ethylene glycol)s (MPEG) with molecular weights of 1900 and 750 were used as redox probe solutes in poly(ethylene glycol) melt solvents of molecular weight 750, 2000, and 20000. Cyclic voltammetry and chronoamperometry at microdisk electrodes were employed to measure the diffusion coefficients of the redox probes, which were independent of the probe concentration and varied between 10{sup -7} and 10{sup -10} cm{sup 2}/s. Diffusional activation barrier results also suggest that the ferrocene label does not significantly influence the diffusivity of the probe molecule in the host solvent. Activation barrier, viscosity, and ionic conductivity results show that the LiClO{sub 4} electrolyte does not influence the diffusion barrier or viscosity as long as the ether O/Li{sup +} ratio is >=250 (ca. 0.1 M) which is still a sufficient electrolyte concentration to allow quantitative electrochemical diffusion measurements. 21 refs., 7 figs., 2 tabs.

  2. Determination of ethanolamine, ethylene glycol and triethylene glycol by ion chromatography for laboratory and field biodegradation studies.

    PubMed

    Mrklas, Ole; Chu, Angus; Lunn, Stuart

    2003-04-01

    The determination of alkanolamines and glycols in groundwater and subsurface environments is essential for environmental assessment, remediation and monitoring for selected industrial sites. Monoethanolamine (MEA), ammonium, sodium, magnesium and calcium detection was performed using cation exchange chromatography (IC) with suppressed conductivity detection. Acetate, chloride, nitrite, nitrate, phosphate, sulfate and oxalate were monitored employing anion exchange chromatography with suppressed conductivity. Detection of ethylene glycol (MEG) and triethylene glycol (TEG) and ethanol was carried out using ion exclusion chromatography with pulsed amperometric detection. Effective determination of MEA, MEG and TEG in complex groundwater matrices without compound transformation offered improved monitoring capabilities. This study presents robust analytical tools for MEA, MEG and TEG determination in biodegradation studies. Using ion chromatography offered significant advantages for the analyses of groundwater samples and laboratory bioreactor monitoring.

  3. Comparative acute and subchronic toxicity of ethylene glycol monopropyl ether and ethylene glycol monopropyl ether acetate.

    PubMed Central

    Katz, G V; Krasavage, W J; Terhaar, C J

    1984-01-01

    The acute toxicity of ethylene glycol monopropyl ether (EGPE) and ethylene glycol monopropyl ether acetate (EGPEA) was determined in a series of standardized tests. The oral LD50 in rats was 3089 and 9456 mg/kg EGPE and EGPEA, respectively. Skin irritation was slight following an occluded single dose application of either compound to the guinea pig abdomen. The dermal LD50 for guinea pigs was 1 to 5 mL/kg and greater than 20 mL/kg EGPE and EGPEA, respectively. EGPE produced a very weak positive sensitization response in one of five guinea pigs. No positive response was elicited when 10 guinea pigs were similarly challenged with EGPEA. EGPE produced transient moderate to severe eye irritation in rabbits while EGPEA produced slight eye irritation. Subchronic toxicity was determined in a series of oral and inhalation studies. Groups of 10 male rats were dosed with 15, 7.5, 3.75 or 1.88 mmole/kg EGPE and 30, 15 or 7.5 mmole/kg EGPEA by gavage 5 days/week for 6 weeks. Hemoglobinuria was seen at least once at all dose levels of both compounds. EGPE had little effect on feed consumption or body weight gain, while body weight gain was reduced in the two high dose groups exposed to EGPEA and feed consumption was reduced at all dose levels. Hematologic changes were seen at all dose levels of both compounds. Absolute and/or relative spleen weights were increased at all but the lowest EGPE dose level and at all EGPEA dose levels. Gross and histopathologic examinations revealed significant effects on the spleen of animals exposed to EGPE and on the spleen, liver, kidney and testes of animals exposed to EGPEA. The no-observed effect level (NOEL) for splenic changes was 1.88 mmole/kg EGPE. A NOEL for hematology was not established. The NOEL for liver and testicular changes were 15 and 7.5 mmole/kg EGPEA, respectively while a NOEL for hematologic, splenic and renal changes was not established. Groups of 10 rats (5M, 5F) were exposed to 800, 400, 200 or 100 ppm EGPE or EGPEA 6 hr

  4. 21 CFR 173.220 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 1,3-Butylene glycol. 173.220 Section 173.220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents...

  5. 21 CFR 173.220 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 1,3-Butylene glycol. 173.220 Section 173.220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents...

  6. 21 CFR 173.220 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 1,3-Butylene glycol. 173.220 Section 173.220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents...

  7. 21 CFR 173.220 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false 1,3-Butylene glycol. 173.220 Section 173.220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.220...

  8. 21 CFR 173.220 - 1,3-Butylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 1,3-Butylene glycol. 173.220 Section 173.220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN...

  9. Ethylene glycol toxicosis in adult beef cattle fed contaminated feeds

    PubMed Central

    Barigye, Robert; Mostrom, Michelle; Dyer, Neil W.; Newell, Teresa K.; Lardy, Gregory P.

    2008-01-01

    Acute deaths of cows held in a drylot and fed several crop processing plant by-products were investigated. Clinical signs in affected cows included diarrhea, ataxia, recumbency, hypersalivation, and sunken eyes. A histological diagnosis of ethylene glycol toxicosis, based on numerous birefringent crystals in renal tubules, was supported by toxicologic findings. PMID:19119372

  10. Direct Routes from Synthesis Gas to Ethylene Glycol.

    ERIC Educational Resources Information Center

    Dombek, B. D.

    1986-01-01

    Discusses the synthesis of ethylene glycol from carbon monoxide and hydrogen using bimetallic catalysts. Although this technology has not been implemented, it illustrates two important future trends, namely, use of bimetallic catalysts and use of coal-derived carbon monoxide and hydrogen as a new feed stock. (JN)

  11. Structure, depolymerization, and cytocompatibility evaluation of glycol chitosan.

    PubMed

    Knight, Darryl K; Shapka, Stephen N; Amsden, Brian G

    2007-12-01

    Glycol chitosan, a water soluble chitosan derivative being investigated as a new biomaterial, was fractionated via two different methods. Initial characterization of the glycol chitosan with (1)H NMR spectroscopy illustrated the presence of both secondary and tertiary amine groups, contradictory to its widely accepted structure. Fractionation of glycol chitosan with nitrous acid resulted in a significant reduction in the number average molecular weight, specifically, from 170 to approximately 7 kDa for a pH 3 and below. However, the reaction altered its chemical structure, as the secondary amine groups were converted to N-nitrosamines, which are potentially carcinogenic. An increase in the pH of the reaction limited this formation, but not entirely. Free radical degradation initiated with potassium persulfate was not as effective at reducing the molecular weight as the nitrous acid approach, yielding molecular weights around 12 kDa under the same molar ratio of degrading species, but did retain the structural integrity of the glycol chitosan. Additionally, control of the molecular weight appears feasible with potassium persulfate. When assessed in vitro for cytocompatibility, the polymer exhibited no toxicity on monolayer-cultured chondrocytes, and in fact stimulated cell growth at low concentrations. PMID:17559127

  12. Ethylene glycol emissions from on-road vehicles.

    PubMed

    Wood, Ezra C; Knighton, W Berk; Fortner, Ed C; Herndon, Scott C; Onasch, Timothy B; Franklin, Jonathan P; Worsnop, Douglas R; Dallmann, Timothy R; Gentner, Drew R; Goldstein, Allen H; Harley, Robert A

    2015-03-17

    Ethylene glycol (HOCH2CH2OH), used as engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's law coefficient. We present measurements of ethylene glycol (EG) vapor in the Caldecott Tunnel near San Francisco, using a proton transfer reaction mass spectrometer (PTR-MS). Ethylene glycol was detected at mass-to-charge ratio 45, usually interpreted as solely coming from acetaldehyde. EG concentrations in bore 1 of the Caldecott Tunnel, which has a 4% uphill grade, were characterized by infrequent (approximately once per day) events with concentrations exceeding 10 times the average concentration, likely from vehicles with malfunctioning engine coolant systems. Limited measurements in tunnels near Houston and Boston are not conclusive regarding the presence of EG in sampled air. Previous PTR-MS measurements in urban areas may have overestimated acetaldehyde concentrations at times due to this interference by ethylene glycol. Estimates of EG emission rates from the Caldecott Tunnel data are unrealistically high, suggesting that the Caldecott data are not representative of emissions on a national or global scale. EG emissions are potentially important because they can lead to the formation of secondary organic aerosol following oxidation in the atmospheric aqueous phase.

  13. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  14. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  15. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  16. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  17. 21 CFR 172.858 - Propylene glycol alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Propylene glycol alginate. 172.858 Section 172.858 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices,...

  18. 21 CFR 172.858 - Propylene glycol alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol alginate. 172.858 Section 172.858 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices, and in confections...

  19. 21 CFR 172.858 - Propylene glycol alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Propylene glycol alginate. 172.858 Section 172.858 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices,...

  20. 21 CFR 172.858 - Propylene glycol alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Propylene glycol alginate. 172.858 Section 172.858 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices,...

  1. 21 CFR 172.858 - Propylene glycol alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propylene glycol alginate. 172.858 Section 172.858 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices,...

  2. Processes and systems for the production of propylene glycol from glycerol

    DOEpatents

    Frye, John G; Oberg, Aaron A; Zacher, Alan H

    2015-01-20

    Processes and systems for converting glycerol to propylene glycol are disclosed. The glycerol feed is diluted with propylene glycol as the primary solvent, rather than water which is typically used. The diluted glycerol feed is sent to a reactor where the glycerol is converted to propylene glycol (as well as other byproducts) in the presence of a catalyst. The propylene glycol-containing product from the reactor is recycled as a solvent for the glycerol feed.

  3. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  4. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  5. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  6. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions as specified in...

  7. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  8. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions as specified in...

  9. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Glycol dehydration unit process vent... Storage Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions...

  10. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  11. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Glycol dehydration unit process vent... Storage Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions...

  12. 21 CFR 500.50 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409...

  13. 21 CFR 500.50 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409...

  14. 21 CFR 500.50 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409...

  15. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  19. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  1. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  2. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  3. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol mono- and diesters of fats and... CONSUMPTION Multipurpose Additives § 172.856 Propylene glycol mono- and diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to...

  4. Intermediates to ethylene glycol: carbonylation of formaldehyde catalyzed by Nafion solid perfluorosulfonic acid resin

    SciTech Connect

    Hendriksen, D.E.

    1983-01-01

    Details of a series of reactions for the production of ethylene glycol using a catalyst of Nafion solid perfluorosulfonic acid resin was detailed. The reactions included the carbonylation of formaldehyde and esterification and then hydrogenation of the product of the carbonylation, glycolic acid. Other preparations included in the work included methyl glycolate, acetylglycolic acid, methyl acetylglycolate, and methyl methoxyacetate.

  5. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  6. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  7. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  8. Simulated Waste Testing Of Glycolate Impacts On The 2H-Evaporator System

    SciTech Connect

    Martino, C. J.

    2013-08-13

    Glycolic acid is being studied as a total or partial replacement for formic acid in the Defense Waste Processing Facility (DWPF) feed preparation process. After implementation, the recycle stream from DWPF back to the high-level waste tank farm will contain soluble sodium glycolate. Most of the potential impacts of glycolate in the tank farm were addressed via a literature review, but several outstanding issues remained. This report documents the non-radioactive simulant tests impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The testing for which non-radioactive simulants could be used involved the following: the partitioning of glycolate into the evaporator condensate, the impacts of glycolate on metal solubility, and the impacts of glycolate on the formation and dissolution of sodium aluminosilicate scale within the evaporator. The following are among the conclusions from this work: Evaporator condensate did not contain appreciable amounts of glycolate anion. Of all tests, the highest glycolate concentration in the evaporator condensate was 0.38 mg/L. A significant portion of the tests had glycolate concentration in the condensate at less than the limit of quantification (0.1 mg/L). At ambient conditions, evaporator testing did not show significant effects of glycolate on the soluble components in the evaporator concentrates. Testing with sodalite solids and silicon containing solutions did not show significant effects of glycolate on sodium aluminosilicate formation or dissolution.

  9. 21 CFR 500.50 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 500.50 Section 500.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol...

  10. 21 CFR 500.50 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol in or on cat food. 500.50 Section 500.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol...

  11. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyalkylene glycol polyamide ester... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  12. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyalkylene glycol polyamide ester... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  13. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polyalkylene glycol polyamide ester... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  14. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyalkylene glycol polyamide ester... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  15. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyalkylene glycol polyamide ester... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  16. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  17. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  18. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  19. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  20. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Succistearin (stearoyl propylene glycol hydrogen... Other Specific Usage Additives § 172.765 Succistearin (stearoyl propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen succinate) may be safely used...

  1. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  2. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  3. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  4. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  5. 40 CFR 721.10090 - Tertiary amine salt of glycol succinate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Tertiary amine salt of glycol... Specific Chemical Substances § 721.10090 Tertiary amine salt of glycol succinate (generic). (a) Chemical... as tertiary amine salt of glycol succinate (PMN P-01-595) is subject to reporting under this...

  6. Toxicity of formulated glycol deicers and ethylene and propylene glycol to lactuca sativa, lolium perenne, selenastrum capricornutum, and lemna minor

    PubMed

    Pillard; DuFresne

    1999-07-01

    Laboratory studies were conducted to determine the toxicity of ethylene glycol (EG) and propylene glycol (PG) as well as two formulated glycol aircraft deicing/anti-icing fluids (ADAFs) to lettuce (Lactuca sativa), perennial ryegrass (Lolium perenne), a green alga (Selenastrum capricornutum), and duckweed (Lemna minor). Seedling emergence, root length, and shoot length were measured in lettuce and ryegrass; cell growth of the alga and frond growth, chlorophyll a, and pheophytin a of the duckweed were measured. While both the ADAFs and pure glycols were toxic to the test species, there were substantial differences in how the organisms responded to the test materials. ADAFs affected emergence in ryegrass more than in lettuce. However, when considering the sublethal endpoints of root and shoot length, the ADAFs were significantly more toxic to lettuce. The root length 120-h IC25s for lettuce were 2,710 and 21, 270 mg EG/L for the ADAF and pure EG compound, respectively; the root length 120-h IC25s for ryegrass were 4,150 and 3,620 mg EG/L for the ADAF and pure EG compound, respectively. EG and PG ADAFs were more toxic than pure EG or PG to L. minor. To S. capricornutum, EG ADAF toxicity was similar to EG toxicity, however, PG ADAF was substantially more toxic to the alga than pure PG. The greater toxicity of ADAFs is reflective of other studies using animals and suggests that although glycols no doubt contribute to toxicity in deicer formulations, other compounds in the mixtures also contribute to the toxicity of the deicers. However, differences in responses between the four plant species suggest differences in modes of action and/or how the plants metabolize the compounds.http://link. springer-ny.com/link/service/journals/00244/bibs/37n1p29.html

  7. Propylene Glycol Poisoning From Excess Whiskey Ingestion: A Case of High Osmolal Gap Metabolic Acidosis.

    PubMed

    Cunningham, Courtney A; Ku, Kevin; Sue, Gloria R

    2015-01-01

    In this report, we describe a case of high anion gap metabolic acidosis with a significant osmolal gap attributed to the ingestion of liquor containing propylene glycol. Recently, several reports have characterized severe lactic acidosis occurring in the setting of iatrogenic unintentional overdosing of medications that use propylene glycol as a diluent, including lorazepam and diazepam. To date, no studies have explored potential effects of excess propylene glycol in the setting of alcohol intoxication. Our patient endorsed drinking large volumes of cinnamon flavored whiskey, which was likely Fireball Cinnamon Whisky. To our knowledge, this is the first case of propylene glycol toxicity from an intentional ingestion of liquor containing propylene glycol.

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

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1986-01-01

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

  9. Propylene Glycol Poisoning From Excess Whiskey Ingestion: A Case of High Osmolal Gap Metabolic Acidosis.

    PubMed

    Cunningham, Courtney A; Ku, Kevin; Sue, Gloria R

    2015-01-01

    In this report, we describe a case of high anion gap metabolic acidosis with a significant osmolal gap attributed to the ingestion of liquor containing propylene glycol. Recently, several reports have characterized severe lactic acidosis occurring in the setting of iatrogenic unintentional overdosing of medications that use propylene glycol as a diluent, including lorazepam and diazepam. To date, no studies have explored potential effects of excess propylene glycol in the setting of alcohol intoxication. Our patient endorsed drinking large volumes of cinnamon flavored whiskey, which was likely Fireball Cinnamon Whisky. To our knowledge, this is the first case of propylene glycol toxicity from an intentional ingestion of liquor containing propylene glycol. PMID:26904700

  10. Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles

    SciTech Connect

    Eastman, J. A.; Choi, S. U. S.; Li, S.; Yu, W.; Thompson, L. J.

    2001-02-05

    It is shown that a ''nanofluid'' consisting of copper nanometer-sized particles dispersed in ethylene glycol has a much higher effective thermal conductivity than either pure ethylene glycol or ethylene glycol containing the same volume fraction of dispersed oxide nanoparticles. The effective thermal conductivity of ethylene glycol is shown to be increased by up to 40% for a nanofluid consisting of ethylene glycol containing approximately 0.3 vol% Cu nanoparticles of mean diameter <10 nm. The results are anomalous based on previous theoretical calculations that had predicted a strong effect of particle shape on effective nanofluid thermal conductivity, but no effect of either particle size or particle thermal conductivity.

  11. Investigation of Volumetric Properties of Some Glycol Ethers Using a Simple Equation of State

    NASA Astrophysics Data System (ADS)

    Moosavi, M.; Goharshadi, E. K.

    2006-09-01

    In this work, a simple equation of state (EoS) has been used to predict the density and other thermodynamic properties such as the isobaric expansion coefficient, α P , the isothermal compressibility, κ T , and the internal pressure, P i , of six glycol ethers including diethylene glycol monobutyl ether (DEGBE), propylene glycol propyl ether (PGPE), diethylene glycol monomethyl ether (DEGME), diethylene glycol monoethyl ether (DEGEE), triethylene glycol dimethyl ether (TriEGDME), and tetraethylene glycol dimethyl ether (TEGDME) at different temperatures and pressures. A comparison with literature experimental data has been made. Additionally, statistical parameters between experimental and calculated densities for the GMA EoS and four other EoSs (Soave Redlich Kwong, Peng Robinson, Soave Redlich Kwong with volume translation, and Patel Teja) indicate the superiority of the GMA EoS.

  12. Degradation and compatibility behaviors of poly(glycolic acid) grafted chitosan.

    PubMed

    Zhang, Luzhong; Dou, Sufeng; Li, Yan; Yuan, Ying; Ji, Yawei; Wang, Yaling; Yang, Yumin

    2013-07-01

    The films of poly(glycolic acid) grafted chitosan were prepared without using a catalyst to improve the degradable property of chitosan. The films were characterized by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The degradation of the poly(glycolic acid) grafted chitosan films were investigated in the lysozyme solution. In vitro degradation tests revealed that the degradation rate of poly(glycolic acid) grafted chitosan films increased dramatically compared with chitosan. The degradation rate of poly(glycolic acid) grafted chitosan films gradually increased with the increasing of the molar ratio of glycolic acid to chitosan. Additionally, the poly(glycolic acid) grafted chitosan films have good biocompatibility, as demonstrated by in vitro cytotoxicity of the extraction fluids. The biocompatible and biodegradable poly(glycolic acid) grafted chitosan would be an effective material with controllable degradation rate to meet the diverse needs in biomedical fields.

  13. Glycol Chitosan-Based Fluorescent Theranostic Nanoagents for Cancer Therapy

    PubMed Central

    Rhee, Jin-Kyu; Park, Ok Kyu; Lee, Aeju; Yang, Dae Hyeok; Park, Kyeongsoon

    2014-01-01

    Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms. PMID:25522316

  14. Acute oxalate nephropathy caused by ethylene glycol poisoning

    PubMed Central

    Seo, Jung Woong; Lee, Jong-Ho; Son, In Sung; Kim, Yong Jin; Kim, Do Young; Hwang, Yong; Chung, Hyun Ah; Choi, Hong Seok; Lim, So Dug

    2012-01-01

    Ethylene glycol (EG) is a sweet-tasting, odorless organic solvent found in many agents, such as anti-freeze. EG is composed of four organic acids: glycoaldehyde, glycolic acid, glyoxylic acid and oxalic acid in vivo. These metabolites are cellular toxins that can cause cardio-pulmonary failure, life-threatening metabolic acidosis, central nervous system depression, and kidney injury. Oxalic acid is the end product of EG, which can precipitate to crystals of calcium oxalate monohydrate in the tubular lumen and has been linked to acute kidney injury. We report a case of EG-induced oxalate nephropathy, with the diagnosis confirmed by kidney biopsy, which showed acute tubular injury of the kidneys with extensive intracellular and intraluminal calcium oxalate monohydrate crystal depositions. PMID:26889430

  15. Comparative toxicity of formulated glycol deicers and pure ethylene and propylene glycol to Ceriodaphnia dubia and Pimephales promelas

    SciTech Connect

    Pillard, D.A. )

    1995-02-01

    Airlines use deicers to remove ice and snow from aircraft before flights, and to retard the inflight buildup of these materials. Many of the deicers are formulated mixtures of ethylene glycol (EG) or propylene glycol (PG) and a variety of additives. Because these deicers may be intentionally or accidentally released into aquatic ecosystems, the possibility exists for direct and indirect adverse effects on aquatic organisms. Laboratory studies evaluated the comparative toxicity of formulated glycol deicers and pure materials on the water flea, Ceriodaphnia dubia, and fathead minnow, Pimephales promelas. Acute and short-term chronic tests were performed according to US Environmental Protection Agency (EPA) guidelines. The formulated mixtures were found to be substantially more toxic than either of the pure glycol materials. The 48-h LC50s for C. dubia were 13,140 mg/L and 1,020 mg/L using formulated EG and PG, and 34,400 mg/L and 18,340 mg/L using pure EG and PG, respectively. The 96-h LC50s for P. promelas were 8,050 mg/L and 710 mg/L using formulated EG and PG, and 72,860 mg/L and 55,770 mg/L using pure EG and PG, respectively. Chronic IC25s for C. dubia were 3,960 mg/L and 640 mg/L using formulated EG and PG; 12,310 mg/L and 13,470 mg/L using pure EG and PG. Chronic IC25s for P. promelas were 3,660 mg/L and 110 mg/L using formulated EG and PG; 22,520 mg/L and 6,940 mg/L using pure EG and PG. For airports that have stormwater discharge permits, numerical limits for EG and PG are generally listed; potential toxicity is assumed to be due to the glycol materials. However, other compounds in the mixtures may either contribute substantially to, or in some cases overshadow, the toxicity of the glycol materials.

  16. Synthesis and properties of oligodeoxyribonucleotide-polyethylene glycol conjugates.

    PubMed Central

    Jäschke, A; Fürste, J P; Nordhoff, E; Hillenkamp, F; Cech, D; Erdmann, V A

    1994-01-01

    Pools of oligonucleotide conjugates consisting of 10-400 different molecular species were synthesized. The conjugates contained a varying number of ethylene glycol units attached to 3'-terminal, 5'-terminal and internal positions of the oligonucleotides. Conjugate synthesis was performed by phosphoramidite solid phase chemistry using suitably protected polyethylene glycol phosphoramidites and PEG-derivatized solid supports containing polydisperse PEGs of various molecular weight ranges. The pools were analyzed and fractionated by chromatographic and electrophoretic techniques, and the composition of isolated conjugates was revealed by matrix-assisted laser desorption/ionization mass spectrometry. The number and attachment sites of coupled ethylene glycol units greatly influence the hydrophobicity of the conjugates, as well as their electrophoretic mobilities. Conjugation had little effect on the hybridization behavior of oligonucleotide conjugates with unmodified complementary oligonucleotide strands. Melting temperatures were between 67 and 73 degrees C, depending on the size and number of coupled PEG chains, compared to 68 degrees C for the unmodified duplex. Conjugates with PEG coupled to both 3'- and 5'-terminal positions showed a more than 10-fold increase in exonuclease stability. PMID:7984434

  17. Pressure and temperature dependence of excess enthalpies of methanol + tetraethylene glycol dimethyl ether and methanol + polyethylene glycol dimethyl ether 250

    SciTech Connect

    Lopez, E.R.; Coxam, J.Y.; Fernandez, J.; Grolier, J.P.E.

    1999-12-01

    The excess molar enthalpies at 323.15 K, 373.15 K, and 423.15 K, at 8 MPa, are reported for the binary mixtures methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250). Excess molar enthalpies were determined with a Setaram C-80 calorimeter equipped with a flow mixing cell. For both systems, the excess enthalpies are positive over the whole composition range, increasing with temperature. The H{sup E}(x) curves are slightly asymmetrical, and their maxima are skewed toward the methanol-rich region. The excess enthalpies slightly change with the pressure, the sign of this change being composition-dependent. In the case of mixtures with TEGDME, the experimental H{sup E} values have been compared with those predicted with the Gmehling et al. version of UNIFAC (Dortmund) and the Nitta-Chao and DISQUAC group contribution models.

  18. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  19. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  20. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  1. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  3. Effect of tocopheryl polyethylene glycol succinate on the percutaneous penetration of minoxidil from water/ethanol/polyethylene glycol 400 solutions.

    PubMed

    Sheu, Ming-Thau; Wu, An-Bang; Lin, Keng-Ping; Shen, Chao-Hui; Ho, Hsiu-O

    2006-06-01

    We described to achieve the local retention of minoxidil which has penetrated the skin with minimization of its absorption into the general circulation and elimination of local irritation induced by propylene glycol. The effect of tocopheryl polyethylene glycol succinate (TPGS) on the penetration flux of minoxidil and its retention in the skin from topical minoxidil formulations consisting of water, alcohol, and polyethylene glycol 400 was characterized by an experimental design of ten solvent formulations in this study. Results show that the addition of TPGS was only able to improve the solubility of minoxidil in those solvent systems containing higher proportions of water and PEG 400, and the extent of improvement was also more profound with the addition of TPGS at concentrations higher than 5%. For those solvent systems containing a higher fraction of alcohol, an insignificant change in minoxidil solubility with increasing added amounts of TPGS was noted even with the tendency to decrease the solubility of minoxidil with higher amounts of TPGS. Increasing the amount of TPGS added gradually increased the flux and the corrected flux from solvent formulations with a lower solubility parameter, but decreased those from solvent systems with a higher solubility parameter. With the addition of TPGS, solvent formulation F6 (alcohol:PEG 400 of 50:50) was demonstrated to be the optimal choice by having an improved local effect and a reduced systemic effect compared to the reference of 2% Regaine((R)). Tocopheryl polyethylene glycol succinate (TPGS) was mainly retained locally in the stratum corneum, and the amount was proportional to the increase in the amount of TPGS added to these ten solvent formulations. PMID:16720414

  4. Acid-base equilibria in ethylene glycol--III: selection of titration conditions in ethylene glycol medium, protolysis constants of alkaloids in ethylene glycol and its mixtures.

    PubMed

    Zikolov, P; Zikolova, T; Budevsky, O

    1976-08-01

    Theoretical titration curves are used for the selection of appropriate conditions for the acid-base volumetric determination of weak bases in ethylene glycol medium. The theoretical curves for titration of some alkaloids are deduced graphically on the basis of the logarithmic concentration diagram. The acid-base constants used for the construction of the theoretical titration curves were determined by potentiometric titration in a cell without liquid junction, equipped with a glass and a silver-silver chloride electrode. It is shown that the alkaloids investigated can be determined accurately by visual or potentiometric titration. The same approach for the selection of titration conditions seems to be applicable to other non-aqueous amphiprotic solvents.

  5. Toxic effects of some alcohol and ethylene glycol derivatives on Cladosporium resinae.

    PubMed Central

    Lee, K H; Wong, H A

    1979-01-01

    Eleven commercially available alcohol and ethylene glycol derivatives were tested for their toxicity toward a problem organism in jet fuel, Cladosporium resinae. In the presence of glucose, 20% (vol/vol) ethylene glycol monomethyl ether prevented spore germination and mycelial growth, and 10% (vol/vol) 2-ethoxybutanol, 10% 2-isopropoxyethanol, 10% 3-methoxybutanol, 5% 2-butyloxyethanol, 5% ethylene glycol dibutyl ether, and 5% diethylene glycol monobutyl ether were found to have similar effects. In a biphasic kerosene-water system, 3-methoxybutanol, 2-butyloxyethanol, and diethylene glycol monobutyl ether were again found to be more toxic than ethylene glycol monomethyl ether. Considerable potassium efflux, protein leakage, and inhibition of endogenous respiration were observed in the presence of the more toxic compounds. 2-Butyloxyethanol also caused loss of sterols from cells. PMID:573588

  6. Accidental and intentional poisonings with ethylene glycol in infancy: diagnostic clues and management.

    PubMed

    Saladino, R; Shannon, M

    1991-04-01

    Ethylene glycol has long been recognized as a potentially lethal poison and remains available today as automotive antifreeze and windshield deicer fluids. Ethylene glycol is rapidly absorbed from the gastrointestinal tract, with peak levels measured one to four hours after ingestion. Metabolism of the parent compound and the production of several organic acids are responsible for the metabolic acidosis observed in ethylene glycol poisoning. Target organ cellular damage is seen in the kidney, brain, myocardium, pancreas, and blood vessel walls. Renal tubular deposition of calcium oxalate crystals is felt to be responsible for the development of the severe renal injury which may accompany ethylene glycol ingestion. The clinical course is quite varied and includes inebriation, hematuria, cardiorespiratory compromise, and neurologic effects. Prompt diagnosis and initiation of treatment, including ethanol therapy and hemodialysis, is necessary to ameliorate the effects of ethylene glycol ingestion. Two cases of ethylene glycol poisoning, one accidental and one intentional, are reviewed.

  7. Echogenic Glycol Chitosan Nanoparticles for Ultrasound-Triggered Cancer Theranostics.

    PubMed

    Min, Hyun Su; You, Dong Gil; Son, Sejin; Jeon, Sangmin; Park, Jae Hyung; Lee, Seulki; Kwon, Ick Chan; Kim, Kwangmeyung

    2015-01-01

    Theranostic nanoparticles hold great promise for simultaneous diagnosis of diseases, targeted drug delivery with minimal toxicity, and monitoring of therapeutic efficacy. However, one of the current challenges in developing theranostic nanoparticles is enhancing the tumor-specific targeting of both imaging probes and anticancer agents. Herein, we report the development of tumor-homing echogenic glycol chitosan-based nanoparticles (Echo-CNPs) that concurrently execute cancer-targeted ultrasound (US) imaging and US-triggered drug delivery. To construct this novel Echo-CNPs, an anticancer drug and bioinert perfluoropentane (PFP), a US gas precursor, were simultaneously encapsulated into glycol chitosan nanoparticles using the oil in water (O/W) emulsion method. The resulting Echo-CNPs had a nano-sized particle structure, composing of hydrophobic anticancer drug/PFP inner cores and a hydrophilic glycol chitosan polymer outer shell. The Echo-CNPs had a favorable hydrodynamic size of 432 nm, which is entirely different from the micro-sized core-empty conventional microbubbles (1-10 μm). Furthermore, Echo-CNPs showed the prolonged echogenicity via the sustained microbubble formation process of liquid-phase PFP at the body temperature and they also presented a US-triggered drug release profile through the external US irradiation. Interestingly, Echo-CNPs exhibited significantly increased tumor-homing ability with lower non-specific uptake by other tissues in tumor-bearing mice through the nanoparticle's enhanced permeation and retention (EPR) effect. Conclusively, theranostic Echo-CNPs are highly useful for simultaneous cancer-targeting US imaging and US-triggered delivery in cancer theranostics. PMID:26681985

  8. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Heyob, K. M.; Mouser, P. J.

    2014-12-01

    Ethylene glycol (EG) is a commonly used organic additive in hydraulic fracturing fluids used for shale gas recovery. Under aerobic conditions, this compound readily biodegrades to acetate and CO2 or is oxidized through the glycerate pathway. In the absence of oxygen, organisms within genera Desulfovibrio, Acetobacterium, and others can transform EG to acetaldehyde, a flammable and suspected carcinogenic compound. Acetaldehyde can then be enzymatically degraded to ethanol or acetate and CO2. However, little is known on how EG degrades in the presence of other organic additives, particularly under anaerobic conditions representative of deep groundwater aquifers. To better understand the fate and attenuation of glycols within hydraulic fracturing fluids we are assessing their biodegradation potential and pathways in batch anaerobic microcosm treatments. Crushed Berea sandstone was inoculated with groundwater and incubated with either EG or a synthetic fracturing fluid (SFF) containing EG formulations. We tracked changes in dissolved organic carbon (DOC), EG, and its transformation products over several months. Approximately 41% of bulk DOC in SFF is degraded within 21 days, with 58% DOC still remaining after 63 days. By comparison, this same SFF degrades by 70% within 25 days when inoculated with sediment-groundwater microbial communities, suggesting that bulk DOC degradation occurs at a slower rate and to a lesser extent with bedrock. Aerobic biodegradation of EG occurs rapidly (3-7 days); however anaerobic degradation of EG is much slower, requiring several weeks for substantial DOC loss to be observed. Ongoing experiments are tracking the degradation pathways of EG alone and in the presence of SFF, with preliminary data showing incomplete glycol transformation within the complex hydraulic fracturing fluid mixture. This research will help to elucidate rates, processes, and pathways for EG biodegradation and identify key microbial taxa involved in its degradation.

  9. Echogenic Glycol Chitosan Nanoparticles for Ultrasound-Triggered Cancer Theranostics

    PubMed Central

    Min, Hyun Su; You, Dong Gil; Son, Sejin; Jeon, Sangmin; Park, Jae Hyung; Lee, Seulki; Kwon, Ick Chan; Kim, Kwangmeyung

    2015-01-01

    Theranostic nanoparticles hold great promise for simultaneous diagnosis of diseases, targeted drug delivery with minimal toxicity, and monitoring of therapeutic efficacy. However, one of the current challenges in developing theranostic nanoparticles is enhancing the tumor-specific targeting of both imaging probes and anticancer agents. Herein, we report the development of tumor-homing echogenic glycol chitosan-based nanoparticles (Echo-CNPs) that concurrently execute cancer-targeted ultrasound (US) imaging and US-triggered drug delivery. To construct this novel Echo-CNPs, an anticancer drug and bioinert perfluoropentane (PFP), a US gas precursor, were simultaneously encapsulated into glycol chitosan nanoparticles using the oil in water (O/W) emulsion method. The resulting Echo-CNPs had a nano-sized particle structure, composing of hydrophobic anticancer drug/PFP inner cores and a hydrophilic glycol chitosan polymer outer shell. The Echo-CNPs had a favorable hydrodynamic size of 432 nm, which is entirely different from the micro-sized core-empty conventional microbubbles (1-10 μm). Furthermore, Echo-CNPs showed the prolonged echogenicity via the sustained microbubble formation process of liquid-phase PFP at the body temperature and they also presented a US-triggered drug release profile through the external US irradiation. Interestingly, Echo-CNPs exhibited significantly increased tumor-homing ability with lower non-specific uptake by other tissues in tumor-bearing mice through the nanoparticle's enhanced permeation and retention (EPR) effect. Conclusively, theranostic Echo-CNPs are highly useful for simultaneous cancer-targeting US imaging and US-triggered delivery in cancer theranostics. PMID:26681985

  10. Acute renal failure, neuropathy, and myopathy after ingestion of dipropylene glycol fog solution.

    PubMed

    LoVecchio, Frank; Nourani, Cameron; Watts, D J; Wallance, K L; Wax, P M

    2008-06-01

    Dipropylene glycol is used in several industrial products including cosmetics, emulsifiers, solvents, and as a fog solution for dance club special effects. Animal studies have suggested that dipropylene glycol has minimal toxicity. We report a case of a 32-year-old man who ingested more than 500 mL of dipropylene glycol-containing Fantasia fog solution (High Energy Lighting, Houston, TX) and subsequently developed acute renal failure, polyneuropathy, and myopathy.

  11. Allergic reaction to polyethylene glycol in a painter.

    PubMed

    Antolin-Amerigo, D; Sánchez-González, M J; Barbarroja-Escudero, J; Rodríguez-Rodríguez, M; Álvarez-Perea, A; Alvarez-Mon, M

    2015-08-01

    We report a case of a male painter who visited our outpatient clinic after developing a distinct skin reaction 15 min after the ingestion of a laxative solution containing polyethylene glycol (PEG) prior to colonoscopy. He described suffering from the same skin reaction when he was previously exposed to paints that contained PEG-4000. An exposure challenge test with pure PEG-4000, simulating his workplace conditions, elicited a generalized urticarial reaction. Allergy to PEG should be considered in painters who develop urticarial or other systemic symptoms after handling PEG-containing products.

  12. Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid

    NASA Astrophysics Data System (ADS)

    Yadav, Vishnu P.; Mukherjee, Rudra Palash; Bantraj, Kandi; Maity, Sunil K.

    2010-10-01

    The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

  13. Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid

    SciTech Connect

    Yadav, Vishnu P.; Maity, Sunil K.; Mukherjee, Rudra Palash; Bantraj, Kandi

    2010-10-26

    The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

  14. Polyethylene glycol-based homologated ligands for nicotinic acetylcholine receptors☆

    PubMed Central

    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

    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

  15. Effective Antisense Gene Regulation via Noncationic, Polyethylene Glycol Brushes.

    PubMed

    Lu, Xueguang; Jia, Fei; Tan, Xuyu; Wang, Dali; Cao, Xueyan; Zheng, Jiamin; Zhang, Ke

    2016-07-27

    Negatively charged nucleic acids are often complexed with polycationic transfection agents before delivery. Herein, we demonstrate that a noncationic, biocompatible polymer, polyethylene glycol, can be used as a transfection vector by forming a brush polymer-DNA conjugate. The brush architecture provides embedded DNA strands with enhanced nuclease stability and improved cell uptake. Because of the biologically benign nature of the polymer component, no cytotoxicity was observed. This approach has the potential to address several long-lasting challenges in oligonucleotide therapeutics. PMID:27420413

  16. Mode of Action: Oxalate Crystal-Induced Renal Tubule Degeneration and Glycolic Acid-Induced Dysmorphogenesis—Renal and Developmental Effects of Ethylene Glycol

    SciTech Connect

    Corley, Rick A.; Meek, M E.; Carney, E W.

    2005-10-01

    Ethylene glycol can cause both renal and developmental toxicity, with metabolism playing a key role in the mode of action (MOA) for each form of toxicity. Renal toxicity is ascribed to the terminal metabolite oxalic acid, which precipitates in the kidney in the form of calcium oxalate crystals and is believed to cause physical damage to the renal tubules. The human relevance of the renal toxicity of ethylene glycol is indicated by the similarity between animals and humans of metabolic pathways, the observation of renal oxalate crystals in toxicity studies in experimental animals and human poisonings, and cases of human kidney and bladder stones related to dietary oxalates and oxalate precursors. High-dose gavage exposures to ethylene glycol also cause axial skeletal defects in rodents (but not rabbits), with the intermediary metabolite, glycolic acid, identified as the causative agent. However, the mechanism by which glycolic acid perturbs development has not been investigated sufficiently to develop a plausible hypothesis of mode of action, nor have any cases of ethylene glycol-induced developmental effects been reported in humans. Given this, and the variations in sensitivity between animal species in response, the relevance to humans of ethylene glycol-induced developmental toxicity in animals is unknown at this time.

  17. Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease

    PubMed Central

    Lee, Jae Min; Keum, Bora; Yoo, In Kyung; Kim, Seung Han; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Chun, Hoon Jai; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Kim, Myung Gyu; Jo, Sang Kyung

    2016-01-01

    Abstract The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease. We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing. The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients’ reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group. The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function. PMID:27603372

  18. Influence of propylene glycol on aqueous silica dispersions and particle-stabilized emulsions.

    PubMed

    Binks, Bernard P; Fletcher, Paul D I; Thompson, Michael A; Elliott, Russell P

    2013-05-14

    We have studied the influence of adding propylene glycol to both aqueous dispersions of fumed silica nanoparticles and emulsions of paraffin liquid and water stabilized by the same particles. In the absence of oil, aerating mixtures of aqueous propylene glycol and particles yields either stable dispersions, aqueous foams, climbing particle films, or liquid marbles depending on the glycol content and particle hydrophobicity. The presence of glycol in water promotes particles to behave as if they are more hydrophilic. Calculations of their contact angle at the air-aqueous propylene glycol surface are in agreement with these findings. In the presence of oil, particle-stabilized emulsions invert from water-in-oil to oil-in-water upon increasing either the inherent hydrophilicity of the particles or the glycol content in the aqueous phase. Stable multiple emulsions occur around phase inversion in systems of low glycol content, and completely stable, waterless oil-in-propylene glycol emulsions can also be prepared. Accounting for the surface energies at the respective interfaces allows estimation of the contact angle at the oil-polar phase interface; reasonable agreement between measured and calculated phase inversion conditions is found assuming no glycol adsorption on particle surfaces.

  19. Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease.

    PubMed

    Lee, Jae Min; Keum, Bora; Yoo, In Kyung; Kim, Seung Han; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Chun, Hoon Jai; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Kim, Myung Gyu; Jo, Sang Kyung

    2016-09-01

    The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function. PMID:27603372

  20. Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease.

    PubMed

    Lee, Jae Min; Keum, Bora; Yoo, In Kyung; Kim, Seung Han; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Chun, Hoon Jai; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Kim, Myung Gyu; Jo, Sang Kyung

    2016-09-01

    The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function.

  1. The Relative Location of the Dye Staining Endpoint Indicated With Polypropylene Glycol-Based Caries Dye versus Conventional Propylene Glycol-Based Caries Dye

    PubMed Central

    Boston, Daniel W; Jefferies, Steven R; Gaughan, John P

    2008-01-01

    Objectives This study determined the difference in the location of the caries dye staining endpoint of 1% Acid Red dye in propylene glycol versus that of 1% Acid Red dye in polypropylene glycol. Methods Freshly extracted permanent molar crowns with primary occlusal carious lesions were chisel-split axially to expose the lesion in cross-section on both halves. One half was stained with propylene glycol-based dye and the other with polypropylene glycol-based dye. For the control group, both halves were stained with propylene glycol-based dye. The dye staining front was marked on digital images of the stained split surfaces, and the images were aligned using reference notches. The distance between the marked staining front lines was measured in five locations, and the measurement protocol was repeated. Weighted averages and a 95% confidence interval for the distance between marked staining front lines were calculated for the control and experimental groups. Results The weighted average distance for the experimental group (0.298 mm, 95% confidence interval 0.240 mm – 0.357 mm) was about four times that of the control group (0.070 mm, 95% confidence interval 0.051 mm – 0.089 mm). Generally, the marked staining line for the polypropylene glycol-based dye specimens was located shallow (occlusal) to the propylene glycol-based staining line (range −0.12 mm to 0.66 mm). Conclusions The staining endpoint of 1% Acid Red dye in polypropylene glycol is shallower than that of 1% Acid Red dye in propylene glycol. The method is useful for comparing staining endpoints of caries dye formulations. (Eur J Dent 2008;2:29–36) PMID:19212506

  2. Ethylene glycol-assisted coating of titania on nanoparticles.

    PubMed

    Dahl, Michael; Castaneda, Fernando; Joo, Ji Bong; Reyes, Victor; Goebl, James; Yin, Yadong

    2016-06-14

    Coating titania shells onto sub-micron sized particles has been widely studied recently, with success mainly limited to objects with sizes above 50 nm. Direct coating on particles below this size has been difficult to attain especially with good control over properties such as thickness and crystallinity. Here we demonstrate that titanium-glycolate formed by reacting titanium alkoxide and ethylene glycol is an excellent precursor for coating titania on aqueous nanoparticles. The new coating method is particularly useful for its ability to coat materials lacking strong polymers or ligands which are frequently needed to facilitate typical titania coatings. We demonstrate the effectiveness of the process of coating titania on metal nanoparticles ranging from citrate-stabilized gold and silver spheres to gold nanorods and silver nanoplates, and larger particles such as SiO2 microspheres and polymer spheres. Further the thickness of these coatings can be tuned from a few nanometers to ∼40 nm through sequential coatings. These coatings can subsequently be crystallized into TiO2 through refluxing in water or by calcination to obtain crystalline shells. This procedure can be very useful for the production of TiO2 coatings with tunable thickness and crystallinity as well as for further study on the effect of TiO2 coatings on nanoparticles.

  3. Hydrogenolysis of ethylene glycol to methanol over modified RANEY® catalysts.

    PubMed

    Wu, Cheng-Tar; Qu, Jin; Elliott, Joseph; Yu, Kai Man Kerry; Tsang, Shik Chi Edman

    2013-06-21

    There is tremendous growing interest in utilizing biomass molecules for energy provision due to their carbon neutrality. Here, we employ ethylene glycol as a model compound for catalytic activation, which represents a basic unit for complex carbohydrate molecules (polyols). In this paper, hydrogenolysis of ethylene glycol to produce methanol in hydrogen over modified RANEY® Ni and Cu catalysts has been studied. This work provides essential information that may leads to the development of new catalysts for carbohydrate activation to methanol, a novel but important reaction concerning biomass conversion to transportable form of energy. Particularly, in this study, modification of electronic structure hence adsorption properties of RANEY® catalysts has mainly been achieved by blending with second metal(s). It is found that the activity and selectivity of this reaction can be significantly affected by this approach. In contrast, there is no subtle effect on methanol selectivity despite a great variation in the d-band centre position which shows a distinctive effect on other products. This result suggests that methanol is produced on specific surface sites independent from the other sites at an intrinsic rate and will not be converted to other products by the d-band alteration. PMID:23661262

  4. The Mm-Wave Rotational Spectrum of Glycolic Acid

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Pszczółkowski, Lech; Białkowska-Jaworska, Ewa; Charnley, Steven B.

    2014-06-01

    Glycolic acid, HOCH_2COOH is the simplest α-hydroxy acid. It is as yet undetected in the interstellar medium, but is known to be present in carbonaceous meteorites and in residues from UV-photolysed interstellar ice analogue mixtures. Prior rotational spectroscopy has been carried out up to 40 GHz for the main, SSC conformer, Presently we report the analysis of the rotational spectrum of glycolic acid on the basis of broadband measurements performed up to 318 GHz, and updated spectroscopic constants for the ground state and the first two excited states of the low-frequency ν21 torsional mode. We have used the AABS package to assign multiple further excited vibrational states of the SSC conformer. In particular, we have been able to assign the highly perturbed triad of ν14, ν20 and 3ν21 states. The triad has been fitted down to experimental accuracy with a coupled fit, which allowed us to pin down the hitherto elusive frequency of the ν21 mode. The experimental results make an interesting comparison with those of anharmonic force field calculations. We have also been able to extend the measurements for the AAT conformer. C.E.Blom, A.Bauder, Chem. Phys. Lett., 82, 492 (1981), J. Am. Chem. Soc., 104, 2993 (1982). H.Hasegawa, O.Ohashi, I.Yamaguchi, J. Mol. Spectrosc., 82, 205 (1982). P.D.Godfrey, F.M.Rodgers, R.D.Brown, J. Am. Chem. Soc., 119, 2232 (1997).

  5. Behavioral teratology of ethylene glycol monomethyl and monoethyl ethers

    SciTech Connect

    Nelson, B.K.; Brightwell, W.S.

    1984-08-01

    A recent addition to the field of teratology has been the inclusion of functional assessment techniques of offspring after prenatal exposure to exogenous agents. The present paper reviews the behavioral teratogenic effects of ethylene glycol monomethyl ether (EGME, 2-methoxyethanol) and ethylene glycol monoethyl ether (EGEE, 2-ethoxyethanol). Groups of 15 pregnant rats were exposed via inhalation to 25 ppm EGME or to 100 ppm EGEE on gestation days 7 to 13 or 14 to 20. An equal number of sham-exposed controls were included for both periods of gestation. The only effect noted in the maternal animals was a slightly prolonged gestation in the group exposed to 100 ppm EGEE on days 14 to 20. Litters were culled in four female and four male pups on the day of birth. Pups of each sex from all litters were tested on a variety of behavioral tasks (including tests of neuromuscular ability, activity, and learning ability) extending from postnatal days 10 to 90. In addition, brains from newborn and from 21-day-old offspring were removed and analyzed for concentrations of the neurotransmitters acetylcholine, dopamine, norepinephrine, and 5-hydroxytryptamine (serotonin). Both the behavioral testing and the neurochemical evaluations revealed functional alterations in the litter groups experiencing prenatal exposure to EGME and EGEE at concentrations which produced no observable effects in the maternal animals. 6 references, 3 tables.

  6. Prehospital diagnosis of massive ethylene glycol poisoning and use of an early antidote.

    PubMed

    Amathieu, Roland; Merouani, Medhi; Borron, Stephen W; Lapostolle, Frédéric; Smail, Nadia; Adnet, Frédéric

    2006-08-01

    We report the case of a patient suspected of voluntary massive poisoning by ethylene glycol. Prehospital diagnosis was established by portable blood analyser and an early antidote with 4 MP treatment initiated in out-of-hospital setting. Use of portable blood analyser in prehospital care should be considered in case of suspected massive poisoning by ethylene glycol. PMID:16808995

  7. Kinetics of the reaction of diethylene glycol bis-chloroformate with allyl alcohol

    SciTech Connect

    Alekseev, N.N.; Shtoda, N.F.; Dzumedzei, N.V.

    1988-10-01

    The kinetics of diethylene glycol bis-chloroformate solvolysis by excess allyl alcohol in toluene and carbon tetrachloride has been studied. Under conditions of a pseudofirst order reaction with respect to diethylene glycol bis-chloroformate the activation parameters confirm an addition-detachment mechanism.

  8. Synthesis of Monodispersed Tantalum(V) oxide Nanospheres by an Ethylene Glycol Mediated Route

    EPA Science Inventory

    Tantalum(V) oxide (Ta2O5) nanospheres have been synthesized by a very simple ethylene glycol mediated route. The two-step process involves the formation of glycolate nanoparticles and their subsequent hydrolysis and calcination to generate the final Ta2O5 nanospheres. The synthes...

  9. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug,...

  10. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug,...

  11. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug,...

  12. 40 CFR 63.62 - Redefinition of glycol ethers listed as hazardous air pollutants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., diethylene glycol, and triethylene glycol R-(OCH2CH2)n-OR′. Where: n = 1, 2, or 3; R = alkyl C7 or less; or R = phenyl or alkyl substituted phenyl; R′= H or alkyl C7 or less; or OR′ consisting of carboxylic acid...

  13. 40 CFR 63.62 - Redefinition of glycol ethers listed as hazardous air pollutants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., diethylene glycol, and triethylene glycol R-(OCH2CH2)n-OR′. Where: n = 1, 2, or 3; R = alkyl C7 or less; or R = phenyl or alkyl substituted phenyl; R′= H or alkyl C7 or less; or OR′ consisting of carboxylic acid...

  14. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Lactylated fatty acid esters of glycerol and... CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and propylene glycol may be safely used...

  15. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  16. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  17. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible...

  18. 21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.856 Propylene glycol mono- and... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propylene glycol mono- and diesters of fats...

  19. Solvation agent for disulfide precipitates from inhibited glycol-water solutions

    NASA Technical Reports Server (NTRS)

    Taylor, M. F.

    1971-01-01

    Small additions /0.01 percent or less/ of triethanoloamine sodium sulfite adduct to mercapto benzothiazole inhibited glycol water heat transfer solutions containing disulfide precipitate produce marked reduction in amount of precipitate. Adduct is useful as additive in glycol base antifreezes and coolants.

  20. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  1. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  2. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  3. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  4. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  5. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  6. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  7. 21 CFR 573.820 - Polyoxyethylene glycol (400) mono- and dioleates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.820 Polyoxyethylene glycol (400) mono- and dioleates. The food additive polyoxyethylene glycol (400) mono- and dioleates may be safely used as an...

  8. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  9. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  10. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  11. New toxicity data for the propylene glycol ethers - a commitment to public health and safety.

    PubMed

    Spencer, P J

    2005-03-28

    Propylene glycol ethers are a class of solvents used in a wide array of industrial, commercial and consumer applications, such as in paints, cleaners and inks. A robust toxicity database exists for the propylene glycol ethers that provide strong product safety support. Standard toxicity studies conducted under good laboratory practices indicate a lack of genotoxic, developmental and reproductive hazards. Recent testing efforts have primarily focused in two areas: (1) examination of the chronic toxicity/oncogenicity potential of propylene glycol monomethyl ether (PGME) in rats and mice and (2) expansion of the developmental toxicity database to higher molecular weight P-series glycol ether derivatives (i.e. propylene glycol n-propyl ether (PGPE), propylene glycol n-butyl ether (PGBE) and dipropylene glycol n-butyl ether (DPGBE)). In PGME chronic toxicity/oncogenicity studies no treatment-related increases in the incidence of tumors occurred in either species. Like other previously tested P-series derivatives, PGPE, PGBE and DPGBE were negative in rodent and rabbit developmental toxicity studies. Collectively, the toxicity database for P-series glycol ether products continues to support the lack of significant health effects with proper use of the commercial products.

  12. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 589.1001 Section 589.1001 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on...

  13. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol in or on cat food. 589.1001 Section 589.1001 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on...

  14. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... polymer of ethylene oxide and water with a mean molecular weight of 200 to 9,500. (b) It contains no more than 0.2 percent total by weight of ethylene and diethylene glycols if its mean molecular weight is 350 or higher and no more than 0.5 percent total by weight of ethylene and diethylene glycols if its...

  15. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  16. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  17. Maternal exposure to diethylene glycol monomethyl ether: a possible role in the etiology of retrocaval ureter.

    PubMed

    Karaman, M Ihsan; Gürdal, Mesut; Oztürk, Metin; Kanberoğlu, Hüseyin

    2002-08-01

    Retrocaval ureter is a very rare condition. In light of the experimental studies, one of the etiologic factors seems to be maternal contact with diethylene glycol monomethyl ether or ethylene glycol monomethyl ether. A case of cardiovascular, skeletal, and retrocaval ureter anomalies caused by possible maternal contact while pregnant with these materials at her work in a textile factory is presented.

  18. Influence of ethylene glycol and propylene glycol on polymer diffusion in poly(butyl acrylate-co-methyl methacrylate) latex films.

    PubMed

    Schroeder, Walter F; Liu, Yuanqin; Tomba, J Pablo; Soleimani, Mohsen; Lau, Willie; Winnik, Mitchell A

    2010-03-11

    We describe fluorescence resonance energy transfer (FRET) experiments carried out to examine the effect of ethylene glycol and propylene glycol on the early stages of polymer diffusion in poly(butyl acrylate-co-methyl methacrylate) latex films. In our approach, we temporarily arrest the drying process of a wet latex film by sealing the film in a previously cooled airtight sample chamber. This arrests propagation of the drying front and suppresses polymer diffusion during the measurements. We then measure donor fluorescence decays from 0.5 mm diameter spots at various locations on the film. From our analysis, we obtain information about the earliest stages of polymer diffusion as the film is still drying. We also investigate the effect of these glycols on polymer diffusion at longer aging times on predried latex films. Ethylene glycol and propylene glycol retard polymer diffusion at early times immediately after the passing of the drying front but enhance the rate of polymer diffusion at later aging times. This behavior is described quantitatively in terms of free-volume theory and the partitioning of the glycols between the aqueous and polymer phases in the film.

  19. Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2(110)

    SciTech Connect

    Chen, Long; Li, Zhenjun; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

    2014-04-16

    Understanding hydrogen formation on TiO2 surfaces is of great importance as it could provide fundamental insight into water splitting for hydrogen production using solar energy. In this work, hydrogen formation from glycols having different numbers of methyl end-groups have been studied using temperature pro-grammed desorption on reduced, hydroxylated, and oxidized TiO2(110) surfaces. The results from OD-labeled glycols demon-strate that gas-phase molecular hydrogen originates exclusively from glycol hydroxyl groups. The yield is controlled by a combi-nation of glycol coverage, steric hindrance, TiO2(110) order and the amount of subsurface charge. Combined, these results show that proximal pairs of hydroxyl aligned glycol molecules and subsurface charge are required to maximize the yield of this redox reaction. These findings highlight the importance of geometric and electronic effects in hydrogen formation from adsorbates on TiO2(110).

  20. GLYCOLIC-FORMIC ACID FLOWSHEET SLUDGE MATRIX STUDY

    SciTech Connect

    Lambert, D.; Koopman, D.

    2011-06-30

    Testing was completed to demonstrate the viability of the newly developed glycolic acid/formic acid flowsheet on processing in the Defense Waste Processing Facility's (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in DWPF. Four sludge simulants were prepared to cover two compositional ranges in the waste. The first was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium (referred to as HiMn or LoMn in this report). These two options can be combined to form four distinct sludge compositions. The sludge matrix study called for testing each of these four simulants near the minimum acid required for nitrite destruction (100% acid stoichiometry) and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid (150% acid stoichiometry). Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants were used for high and low acid testing. Eight planned experiments (GF26 to GF33) were completed to demonstrate the viability of the glycolic-formic flowsheet. Composition and physical property measurements were made on the SRAT product. Composition measurements were made on the condensate from the Mercury Water Wash Tank (MWWT), Formic Acid Vent Condenser (FAVC), ammonia scrubber and on SRAT samples pulled throughout the SRAT cycle. Updated values for formate loss and nitrite-tonitrate conversion were found that can be used in the acid calculations for future sludge matrix process simulations with the glycolic acid/formic acid flowsheet

  1. Ice recrystallization inhibition in ice cream by propylene glycol monostearate.

    PubMed

    Aleong, J M; Frochot, S; Goff, H D

    2008-11-01

    The effectiveness of propylene glycol monostearate (PGMS) to inhibit ice recrystallization was evaluated in ice cream and frozen sucrose solutions. PGMS (0.3%) dramatically reduced ice crystal sizes in ice cream and in sucrose solutions frozen in a scraped-surface freezer before and after heat shock, but had no effect in quiescently frozen solutions. PGMS showed limited emulsifier properties by promoting smaller fat globule size distributions and enhanced partial coalescence in the mix and ice cream, respectively, but at a much lower level compared to conventional ice cream emulsifier. Low temperature scanning electron microscopy revealed highly irregular crystal morphology in both ice cream and sucrose solutions frozen in a scraped-surface freezer. There was strong evidence to suggest that PGMS directly interacts with ice crystals and interferes with normal surface propagation. Shear during freezing may be required for its distribution around the ice and sufficient surface coverage.

  2. Rheological profile of boron nitride–ethylene glycol nanofluids

    SciTech Connect

    Żyła, Gaweł; Witek, Adam; Gizowska, Magdalena

    2015-01-07

    The paper presents the complete rheological profile of boron nitride (BN)–ethylene glycol (EG) nanofluids. Nanofluids have been produced by two-step method on the basis of commercially available powder of plate-like grains of nanometrical thickness. Viscoelastic structure has been determined in oscillatory measurements at a constant frequency and temperature. Viscosity and flow curves for these materials have been measured. Studies have shown that the Carreau model can be used for the modeling of dynamic viscosity curves of the material. The samples were tested for the presence of thixotropy. The dependence of viscosity on temperature was also examined. The effect of temperature on the dynamic viscosity of BN-EG nanofluids can be modelled with the use of Vogel-Fulcher-Tammann expression.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  5. Polyethylene glycol diffusion in ex vivo skin tissue

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  6. The effect of polyethylene glycol on shellac stability

    NASA Astrophysics Data System (ADS)

    Khairuddin; Pramono, Edi; Budi Utomo, Suryadi; Wulandari, Viki; A'an Zahrotul, W.; Clegg, Francis

    2016-02-01

    The effect of polyethylene glycol (PEG) having amolecular weight of 1000 and 2000 on shellac stability has been investigated in this research. The shellac was shellac wax free, and the solvent was ethanol 96%. Shellac films were prepared by solventevaporationmethod. The stability of shellac was investigated using insoluble solid test, Fourier Transform Infra Red (FTIR), Thermogravimetry Analyzer (TGA), and Water Vapour Transmission Rate (WVTR). The results showed that stability of shellac decreased after heating at 125oC for 10,30,90,and 180 minutes, and storing for 1 month at 27 oC and 85 relative humidity (RH). PEG improved the stability, and the most stable effect was achieved through PEG1000.

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

    SciTech Connect

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

    2014-03-28

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

  8. Developmental pharmacokinetics of propylene glycol in preterm and term neonates

    PubMed Central

    De Cock, Roosmarijn F W; Knibbe, Catherijne A J; Kulo, Aida; de Hoon, Jan; Verbesselt, Rene; Danhof, Meindert; Allegaert, Karel

    2013-01-01

    AIM Propylene glycol (PG) is often applied as an excipient in drug formulations. As these formulations may also be used in neonates, the aim of this study was to characterize the pharmacokinetics of propylene glycol, co-administered intravenously with paracetamol (800 mg PG/1000 mg paracetamol) or phenobarbital (700 mg PG/200 mg phenobarbital) in preterm and term neonates. METHODS A population pharmacokinetic analysis was performed based on 372 PG plasma concentrations from 62 (pre)term neonates (birth weight (bBW) 630–3980 g, postnatal age (PNA) 1–30 days) using NONMEM 6.2. The model was subsequently used to simulate PG exposure upon administration of paracetamol or phenobarbital in neonates (gestational age 24–40 weeks). RESULTS In a one compartment model, birth weight and PNA were both identified as covariates for PG clearance using an allometric function (CLi= 0.0849 × {(bBW/2720)1.69× (PNA/3)0.201}). Volume of distribution scaled allometrically with current bodyweight (Vi= 0.967 × {(BW/2720)1.45}) and was estimated 1.77 times higher when co-administered with phenobarbital compared with paracetamol. By introducing these covariates a large part of the interindividual variability on clearance (65%) as well as on volume of distribution (53%) was explained. The final model shows that for commonly used dosing regimens, the population mean PG peak and trough concentrations range between 33–144 and 28–218 mg l−1 (peak) and 19–109 and 6–112 mg l−1 (trough) for paracetamol and phenobarbital formulations, respectively, depending on birth weight and age of the neonates. CONCLUSION A pharmacokinetic model was developed for PG co-administered with paracetamol or phenobarbital in neonates. As such, large variability in PG exposure may be expected in neonates which is dependent on birth weight and PNA. PMID:22536830

  9. DEVELOPMENT OF A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR ETHYLENE GLYCOL AND ITS MAJOR METABOLITE, GLYCOLIC ACID, IN RATS AND HUMANS

    SciTech Connect

    Corley, Rick A.; Bartels, M J.; Carney, E W.; Weitz, Karl K.; Soelberg, Jolen J.; Gies, Richard A.; Thrall, Karla D.

    2005-05-19

    An extensive database on the toxicity and modes of action of the major industrial chemical, ethylene glycol (EG), has been developed over the past several decades. These studies have consistently identified the kidney as a primary target organ, with rats being more sensitive than mice and males more sensitive than females following chronic exposure. Renal toxicity has been associated with the terminal metabolite, oxalic acid which can precipitate with calcium to form crystals. EG also induces developmental toxicity, although these effects appear to require high-doses or accelerated dose-rates, and have been reported only in rats and mice. The developmental toxicity of EG has been attributed to the intermediate metabolite, glycolic acid (GA). The developmental toxicity of EG has been the subject of extensive research and regulatory review in recent years. Therefore, a physiologically based pharmacokinetic (PBPK) model was developed to integrate the extensive mode of action and pharmacokinetic data on EG and GA for use in developmental risk assessment. Metabolic rate constants and partition coefficients for EG and GA were estimated from in vitro studies. Other biochemical constants were optimized from appropriate in vivo pharmacokinetic studies. The resulting PBPK model includes inhalation, oral, dermal, intravenous and subcutaneous routes of administration. Metabolism of EG and GA were described in the liver with elimination via the kidneys. Several rat and human metabolism studies were used to validate the resulting PBPK model. Consistent with these studies, simulations indicated that the metabolism of EG to GA was essentially first-order (linear) up to 2500 mg/kg/day while the metabolism of GA saturated between bolus ethylene glycol doses of 200 and 1000 mg/kg/day. This saturation results in non-linear increases in blood GA concentrations, correlating with the developmental toxicity of EG. Pregnancy had no effect on maternal EG and GA kinetics over a broad dose

  10. Hydrogel containing silica shell cross-linked micelles for ocular drug delivery.

    PubMed

    Lu, Changhai; Yoganathan, Roshan B; Kociolek, Michael; Allen, Christine

    2013-02-01

    Poly(2-hydroxyethyl methacrylate-methacrylic acid-ethylene glycol dimethacrylate) hydrogels loaded with silica shell cross-linked methoxy(polyethylene glycol)-block-polycaprolactone (MePEG-b-PCL) micelles with rod-like morphology were prepared as a potential soft contact lens material for the sustained release of ocular drugs. The silica shell cross-linked methoxy micelles (SSCMs) comprising a polycaprolactone core surrounded by a silica shell were synthesized and their size, morphology, stability, and drug release kinetics were evaluated. The relationships between the composition of the SSCM-loaded poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels and their transparency, surface wettability, and equilibrium water content were determined. Scanning electron microscopy (SEM) images of SSCM-hydrogel systems showed the presence of intact SSCMs within the hydrogel matrix. Dexamethasone acetate (DMSA), a hydrophobic ophthalmic drug, was loaded into the SSCMs prior to their incorporation into the hydrogels. In vitro release of DMSA from the SSCM-hydrogels, with varying drug loading levels, was observed for up to 30 days. Overall, the incorporation of rod-like SSCMs within pHEMA-based hydrogels provided sustained release over prolonged periods while maintaining optical transparency. This delivery system may be suitable for use as a therapeutic soft contact lens material. PMID:23203974

  11. Determination of the Impact of Glycolate on ARP and MCU Operations

    SciTech Connect

    Taylor-Pashow, K. M.L.; Peters, T. B.; Fondeur, F. F.; Shehee, T. C.; Washington, A. L.

    2012-12-13

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similar to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The

  12. LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY

    SciTech Connect

    Adu-Wusu, K.

    2012-05-10

    Glycolic acid (GA) is being studied as an alternate reductant in the Defense Waste Processing Facility (DWPF) feed preparation process. It will either be a total or partial replacement for the formic acid that is currently used. A literature review has been conducted on the impact of glycolate on two post-DWPF downstream systems - the 2H Evaporator system and the Effluent Treatment Facility (ETF). The DWPF recycle stream serves as a portion of the feed to the 2H Evaporator. Glycolate enters the evaporator system from the glycolate in the recycle stream. The overhead (i.e., condensed phase) from the 2H Evaporator serves as a portion of the feed to the ETF. The literature search revealed that virtually no impact is anticipated for the 2H Evaporator. Glycolate may help reduce scale formation in the evaporator due to its high complexing ability. The drawback of the solubilizing ability is the potential impact on the criticality analysis of the 2H Evaporator system. It is recommended that at least a theoretical evaluation to confirm the finding that no self-propagating violent reactions with nitrate/nitrites will occur should be performed. Similarly, identification of sources of ignition relevant to glycolate and/or update of the composite flammability analysis to reflect the effects from the glycolate additions for the 2H Evaporator system are in order. An evaluation of the 2H Evaporator criticality analysis is also needed. A determination of the amount or fraction of the glycolate in the evaporator overhead is critical to more accurately assess its impact on the ETF. Hence, use of predictive models like OLI Environmental Simulation Package Software (OLI/ESP) and/or testing are recommended for the determination of the glycolate concentration in the overhead. The impact on the ETF depends on the concentration of glycolate in the ETF feed. The impact is classified as minor for feed glycolate concentrations {le} 33 mg/L or 0.44 mM. The ETF unit operations that will have

  13. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA VOL. II: APPENDICES

    EPA Science Inventory

    The report gives results of the collection of emissions test data st two triethylene glycol units to provide data for the comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. [NOTE: Glycol dehydrators are used in the natural gas i...

  14. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA VOL. I: TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of the collection of emissions tests data at two triethylene glycol units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural gas indu...

  15. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  17. 40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diesters with benzoic acid and diethylene glycol. 721.10111 Section 721.10111 Protection of Environment... diesters with benzoic acid and diethylene glycol. (a) Chemical substance and significant new uses subject... benzoic acid and diethylene glycol (PMN P-04-510; CAS No. 610787-78-5) is subject to reporting under...

  18. 40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diesters with benzoic acid and neopentlyl glycol. 721.10110 Section 721.10110 Protection of Environment... diesters with benzoic acid and neopentlyl glycol. (a) Chemical substance and significant new uses subject... benzoic acid and neopentlyl glycol (PMN P-04-509; CAS No. 610787-77-4) is subject to reporting under...

  19. 40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diesters with benzoic acid and diethylene glycol. 721.10111 Section 721.10111 Protection of Environment... diesters with benzoic acid and diethylene glycol. (a) Chemical substance and significant new uses subject... benzoic acid and diethylene glycol (PMN P-04-510; CAS No. 610787-78-5) is subject to reporting under...

  20. 40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diesters with benzoic acid and neopentlyl glycol. 721.10110 Section 721.10110 Protection of Environment... diesters with benzoic acid and neopentlyl glycol. (a) Chemical substance and significant new uses subject... benzoic acid and neopentlyl glycol (PMN P-04-509; CAS No. 610787-77-4) is subject to reporting under...

  1. 40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diesters with benzoic acid and diethylene glycol. 721.10111 Section 721.10111 Protection of Environment... diesters with benzoic acid and diethylene glycol. (a) Chemical substance and significant new uses subject... benzoic acid and diethylene glycol (PMN P-04-510; CAS No. 610787-78-5) is subject to reporting under...

  2. 40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diesters with benzoic acid and diethylene glycol. 721.10111 Section 721.10111 Protection of Environment... diesters with benzoic acid and diethylene glycol. (a) Chemical substance and significant new uses subject... benzoic acid and diethylene glycol (PMN P-04-510; CAS No. 610787-78-5) is subject to reporting under...

  3. 40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diesters with benzoic acid and neopentlyl glycol. 721.10110 Section 721.10110 Protection of Environment... diesters with benzoic acid and neopentlyl glycol. (a) Chemical substance and significant new uses subject... benzoic acid and neopentlyl glycol (PMN P-04-509; CAS No. 610787-77-4) is subject to reporting under...

  4. 40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diesters with benzoic acid and neopentlyl glycol. 721.10110 Section 721.10110 Protection of Environment... diesters with benzoic acid and neopentlyl glycol. (a) Chemical substance and significant new uses subject... benzoic acid and neopentlyl glycol (PMN P-04-509; CAS No. 610787-77-4) is subject to reporting under...

  5. 40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diesters with benzoic acid and neopentlyl glycol. 721.10110 Section 721.10110 Protection of Environment... diesters with benzoic acid and neopentlyl glycol. (a) Chemical substance and significant new uses subject... benzoic acid and neopentlyl glycol (PMN P-04-509; CAS No. 610787-77-4) is subject to reporting under...

  6. 40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diesters with benzoic acid and diethylene glycol. 721.10111 Section 721.10111 Protection of Environment... diesters with benzoic acid and diethylene glycol. (a) Chemical substance and significant new uses subject... benzoic acid and diethylene glycol (PMN P-04-510; CAS No. 610787-78-5) is subject to reporting under...

  7. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  8. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  9. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  10. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  11. Inhibition of heavy metal ion corrosion on aluminum in fresh water cooling systems using propylene glycol anti-freeze

    SciTech Connect

    Hack, H.P.; Corbett, R.; Krantz, B.

    1998-12-31

    Electronics cooling and environmental control systems are required in enclosed manned spaces such as the inside of spacecraft or submersibles. Because egress from such spaces may not be possible in a short time frame, coolant leaks must have minimum toxicity. For this reason, propylene glycol coolants are preferred over the traditional ethylene glycol coolants. Corrosion inhibitor formulations are well developed for ethylene glycol coolants, but there is concern that the inhibitor suite for propylene glycol systems may not be as mature. In particular, coolant systems with a mixture of aluminum and copper can develop heavy metal ion corrosion of the aluminum due to precipitation of copper ions from solution onto the aluminum. This type of accelerated corrosion of aluminum does not require electrical contact with copper, as is the case for galvanic corrosion, nor is significant coolant conductivity required for corrosion to occur. This paper presents a study of the ability of a commercial inhibited propylene glycol coolant to prevent heavy metal ion corrosion of aluminum when copper is also present in the coolant system. The inhibited propylene glycol`s performance is compared to that of reagent propylene glycol without inhibitors, a mature ethylene glycol inhibited coolant, and to tap water. The inhibitor suite in the inhibited propylene glycol was found to be as effective in controlling heavy metal ion corrosion as that of the inhibited ethylene glycol coolant, while uninhibited reagent propylene glycol was ineffective in controlling heavy metal ion corrosion.

  12. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols polyglycidyl ethers (generic name). 721.6980... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  13. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols polyglycidyl ethers (generic name). 721.6980... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  14. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols polyglycidyl ethers (generic name). 721.6980... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  15. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis

    PubMed Central

    Yu, Tao; Zhao, Changfu; Li, Peng; Liu, Guangyao; Luo, Min

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) conduit-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair. PMID:25206505

  16. Experimental Evidence for a Hydride Transfer Mechanism in Plant Glycolate Oxidase Catalysis*

    PubMed Central

    Dellero, Younès; Mauve, Caroline; Boex-Fontvieille, Edouard; Flesch, Valérie; Jossier, Mathieu; Tcherkez, Guillaume; Hodges, Michael

    2015-01-01

    In plants, glycolate oxidase is involved in the photorespiratory cycle, one of the major fluxes at the global scale. To clarify both the nature of the mechanism and possible differences in glycolate oxidase enzyme chemistry from C3 and C4 plant species, we analyzed kinetic parameters of purified recombinant C3 (Arabidopsis thaliana) and C4 (Zea mays) plant enzymes and compared isotope effects using natural and deuterated glycolate in either natural or deuterated solvent. The 12C/13C isotope effect was also investigated for each plant glycolate oxidase protein by measuring the 13C natural abundance in glycolate using natural or deuterated glycolate as a substrate. Our results suggest that several elemental steps were associated with an hydrogen/deuterium isotope effect and that glycolate α-deprotonation itself was only partially rate-limiting. Calculations of commitment factors from observed kinetic isotope effect values support a hydride transfer mechanism. No significant differences were seen between C3 and C4 enzymes. PMID:25416784

  17. Assessment of salinity-induced photorespiratory glycolate metabolism in Anabaena sp. PCC 7120.

    PubMed

    Srivastava, Ashish Kumar; Alexova, Ralitza; Jeon, Young Jae; Kohli, Gurjeet S; Neilan, Brett A

    2011-03-01

    This paper reports an investigation of salinity-induced glycolate metabolism in the cyanobacterium Anabaena sp. PCC 7120 (hereafter Anabaena PCC 7120). Quantitative analysis of transcripts for the photosynthesis-associated genes encoding ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), phosphoribulokinase and transketolase, as well as those involved in glycolate metabolism (phosphoglycolate phosphatase, glycolate oxidase, alanine-glyoxylate aminotransferase and serine hydroxymethyltransferase) was performed. The expression of all investigated photosynthesis-associated genes except Rubisco was downregulated after 24 h NaCl treatment. However, under the same conditions, the transcripts encoding enzymes involved in glycolate metabolism were overexpressed. This was further confirmed by the quantitative analysis of the intermediates involved in glycolate metabolism. The intracellular levels of organic acids (glyceric, glycolic and glyoxylic acids) and amino acids (glycine and serine) were elevated in salt-treated cells as compared to those in the control cells. Transcriptional inhibition of photosynthesis-associated genes, and upregulation of genes and enhanced synthesis of intermediates associated with glycolate metabolism, indicate the occurrence of this photorespiratory metabolic pathway metabolism in Anabaena PCC 7120 under salt stress. PMID:21163840

  18. Assessment of salinity-induced photorespiratory glycolate metabolism in Anabaena sp. PCC 7120.

    PubMed

    Srivastava, Ashish Kumar; Alexova, Ralitza; Jeon, Young Jae; Kohli, Gurjeet S; Neilan, Brett A

    2011-03-01

    This paper reports an investigation of salinity-induced glycolate metabolism in the cyanobacterium Anabaena sp. PCC 7120 (hereafter Anabaena PCC 7120). Quantitative analysis of transcripts for the photosynthesis-associated genes encoding ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), phosphoribulokinase and transketolase, as well as those involved in glycolate metabolism (phosphoglycolate phosphatase, glycolate oxidase, alanine-glyoxylate aminotransferase and serine hydroxymethyltransferase) was performed. The expression of all investigated photosynthesis-associated genes except Rubisco was downregulated after 24 h NaCl treatment. However, under the same conditions, the transcripts encoding enzymes involved in glycolate metabolism were overexpressed. This was further confirmed by the quantitative analysis of the intermediates involved in glycolate metabolism. The intracellular levels of organic acids (glyceric, glycolic and glyoxylic acids) and amino acids (glycine and serine) were elevated in salt-treated cells as compared to those in the control cells. Transcriptional inhibition of photosynthesis-associated genes, and upregulation of genes and enhanced synthesis of intermediates associated with glycolate metabolism, indicate the occurrence of this photorespiratory metabolic pathway metabolism in Anabaena PCC 7120 under salt stress.

  19. The effect of ethylene glycol on the phytovolatilization of 1,4-dioxane.

    PubMed

    Edwards, Maureen R A; Hetu, Marie-France; Columbus, Melanie; Silva, Anthony; Lefebvre, Daniel D

    2011-08-01

    Phytoremediation at contaminated sites is often complicated by the presence of more than one chemical However, the effects of common co-contaminants such as ethylene glycol on the phytoremediation of other chemicals, e.g., 1,4-dioxane, is not well understood. Field studies with DN34 poplar trees revealed a 28% decline in growth rate in response to 10 g/L ethylene glycol in the groundwater, thus indicating a significant and deleterious effect on tree viability, and likely, the plants' utility for phytoremediation. Thorough investigations using Arabidopsis thaliana, with its small size and rapid life cycle, indicated significant growth reduction at 10 g/L and complete inhibition of germination at 40 g/L ethylene glycol Ethylene glycol was almost as severe a stressor as the well characterized osmotic inhibitor, sorbitoL Watering potted trees with 10 g/L ethylene glycol reduced their growth by more than 50%, and similar results were observed in hydroponically grown poplar and willow trees. Under hydroponic conditions, 60 g/L ethylene glycol inhibited the phytovolatilization of l,4-dioxane by more than 80%, and all trees evapo-transpired 1,4-dioxane less efficiently than water. In fact, this efficiency differed between trees and the difference became more pronounced in the presence of ethylene glycol.

  20. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis.

    PubMed

    Yu, Tao; Zhao, Changfu; Li, Peng; Liu, Guangyao; Luo, Min

    2013-07-25

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) conduit-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  1. Impact of the propylene glycol-water-borax coolant on material recovery operations

    SciTech Connect

    Duerksen, W.K.; Taylor, P.A.

    1983-05-01

    The reaction of the propylene glycol-water-borax coolant with nitric acid has now been studied in some detail. This document is intended to provide a summary of the results. Findings are summarized under nine headings. Tests have also been conducted to determine if the new coolant would have any adverse effects on the uranium recycle systems. Experiments were scientifically designed after observation of the production operations so that accurate response to the immediate production concerns could be provided. Conclusions from these studies are: formation of glycol nitrates is very improbable; the reaction of concentrated (70%) nitric acid with pure propylene glycol is very violent and hazardous; dilution of the nitric acid-glycol mixture causes a drastic decrease in the rate and intensity of the reaction; the mechanism of the nitric acid propylene glycol reaction is autocatalytic in nitrous acid; no reaction is observed between coolant and 30% nitric acid unless the solution is heated; the coolant reacts fairly vigorously with 55% nitric acid after a concentration-dependent induction time; experiments showed that the dissolution of uranium chips that had been soaked in coolant proceeded at about the same rate as if the chips had not previously contacted glycol; thermodynamic calculations show that the enthalpy change (heat liberated) by the reaction of nitric acid (30%) with propylene glycol is smaller than if the same amount of nitric acid reacted with uranium. Each of these conclusions is briefly discussed. The effect of new coolant on uranium recycle operations is then briefly discussed.

  2. Recent progress in alkaline direct ethylene glycol fuel cells for sustainable energy production

    NASA Astrophysics Data System (ADS)

    An, L.; Chen, R.

    2016-10-01

    Alkaline direct ethylene glycol fuel cells are one of the most promising power sources for portable, mobile and stationary power applications, primarily because this type of fuel cell runs on a sustainable fuel and the key materials that constitute the fuel cell are relatively inexpensive. This review article summarizes and discusses the past investigations on the development of alkaline direct ethylene glycol fuel cells, including the physical and chemical processes through the fuel cell structure, the electrocatalytic oxidation and electrocatalysts of ethylene glycol, the singe-cell performance, and innovative system designs.

  3. A detailed chemical kinetic model of high-temperature ethylene glycol gasification

    NASA Astrophysics Data System (ADS)

    Hafner, Simon; Rashidi, Arash; Baldea, Georgiana; Riedel, Uwe

    2011-08-01

    In recent experimental investigations, ethylene glycol is used as a model substance for biomass-based pyrolysis oil in an entrained flow gasifier. In order to gain a deeper insight into process sequences and to conduct parametric analysis, this study describes the development and validation of a detailed chemical kinetic model of high-temperature ethylene glycol gasification. A detailed reaction mechanism based on elementary reactions has been developed considering 80 species and 1243 reactions for application in CFD software. In addition to mechanism validation based on ignition delay times, laminar flame speeds and concentration profiles, simulation results are compared to experimental data of ethylene glycol gasification under complex turbulent reactive flow conditions.

  4. Allergic contact dermatitis to propyl gallate and pentylene glycol in an emollient cream.

    PubMed

    Foti, Caterina; Bonamonte, Domenico; Cassano, Nicoletta; Conserva, Anna; Vena, Gino A

    2010-05-01

    A 62-year-old man, with a 20-year history of seborrhoeic dermatitis, presented with a worsening of his dermatitis. He had previously been demonstrated to be allergic to various topical corticosteroids, so he had been using an emollient cream (Sebclair), containing piroctone olamine and various anti-inflammatory substances, for 6 months, with good effect. Patch testing to the cream and its ingredients revealed positive reactions to both propyl gallate and pentylene glycol. A positive reaction to propylene glycol was also detected, whereas patch testing to butylene glycol was negative. Complete remission followed avoidance of the offending substances. PMID:20546226

  5. Inhibitive Performance of Monoethylene Glycol on CO2 Corrosion of API 5L X52 Steel

    NASA Astrophysics Data System (ADS)

    Javidi, M.; Khodaparast, M.

    2015-04-01

    Monoethylene glycol has been utilized in wet natural gas transportation to avoid hydrate formation and corrosion. The inhibitive performance of monoethylene glycol (MEG) on CO2 corrosion of API 5L X52 steel in saline solution at 50 °C was studied using electrochemical techniques. Change in inhibition mechanism of MEG against CO2 corrosion was observed including the blocking of reaction sites by MEG in low concentration and slow down of corrosion reactions at high concentration. The presence of different concentrations of sodium chloride affects the corrosion rate in a different manner for rich and lean glycol solution.

  6. Effects of Aminooxyacetate and Aminoacetonitrile on Glycolate and Ammonia Release by the Cyanobacterium Anabaena cylindrica1

    PubMed Central

    Bergman, Birgitta; Renström, Eva; Hällbom, Lars; Codd, Geoffrey A.

    1985-01-01

    Aminooxyacetate and aminoacetonitrile cause increased excretion of glycolate by the cyanobacterium Anabaena cylindrica. Both compounds also reduce NH4-N release induced by methionine sulfoximine in non-nitrogen-fixing cultures. Changes in amino acid pool sizes together with changes in activities of some enzymes related to glycolate metabolism show that glyoxylate to glycine conversion and glycine to serine conversion are inhibited by aminooxyacetate and aminoacetonitrile, respectively. The results also verify that photorespiratory glycolate metabolism via amination of glyoxylate is operative in A. cylindrica. PMID:16664093

  7. Development of a w/o/w emulsion for chemical peeling applications containing glycolic acid.

    PubMed

    Yener, Gülgün; Baitokova, Aida

    2006-01-01

    Glycolic acid is a member of the AHA family, which occurs naturally in foods and has been used for centuries as a cutaneous rejuvenation treatment. It is used in many cosmetic products as an exfoliant and moisturizer. When glycolic acid is used in greater amounts, however, there are greater cosmetic benefits but also potential for skin irritation as far as burning increases. The aim of this work was to investigate the feasibility of a topical delivery system as a multiple emulsion combining glycolic acid, strontium nitrate, and dexpanthenol in order to optimize the acid's cosmetic properties and lowering its side effects. PMID:17256078

  8. Staining methods applied to glycol methacrylate embedded tissue sections.

    PubMed

    Cerri, P S; Sasso-Cerri, E

    2003-01-01

    The use of glycol methacrylate (GMA) avoids some technical artifacts, which are usually observed in paraffin-embedded sections, providing good morphological resolution. On the other hand, weak staining have been mentioned during the use of different methods in plastic sections. In the present study, changes in the histological staining procedures have been assayed during the use of staining and histochemical methods in different GMA-embedded tissues. Samples of tongue, submandibular and sublingual glands, cartilage, portions of respiratory tract and nervous ganglion were fixed in 4% formaldehyde and embedded in glycol methacrylate. The sections of tongue and nervous ganglion were stained by H&E. Picrosirius, Toluidine Blue and Sudan Black B methods were applied, respectively, for identification of collagen fibers in submandibular gland, sulfated glycosaminoglycans in cartilage (metachromasia) and myelin lipids in nervous ganglion. Periodic Acid-Schiff (PAS) method was used for detection of glycoconjugates in submandibular gland and cartilage while AB/PAS combined methods were applied for detection of mucins in the respiratory tract. In addition, a combination of Alcian Blue (AB) and Picrosirius methods was also assayed in the sublingual gland sections. The GMA-embedded tissue sections showed an optimal morphological integrity and were favorable to the staining methods employed in the present study. In the sections of tongue and nervous ganglion, a good contrast of basophilic and acidophilic structures was obtained by H&E. An intense eosinophilia was observed either in the striated muscle fibers or in the myelin sheaths in which the lipids were preserved and revealed by Sudan Black B. In the cartilage matrix, a strong metachromasia was revealed by Toluidine Blue in the negatively-charged glycosaminoglycans. In the chondrocytes, glycogen granules were intensely positive to PAS method. Extracellular glycoproteins were also PAS positive in the basal membrane and in the

  9. DETERMINATION OF THE IMPACT OF GLYCOLATE ON ARP AND MCU OPERATIONS

    SciTech Connect

    Taylor-Pashow, K.; Peters, T.; Shehee, T.

    2012-06-04

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5,000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5,000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similarly to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The presence of glycolate did not change the lack

  10. Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use

    PubMed Central

    Shin, Chan Young; Kim, Kyu-Bong

    2015-01-01

    Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient. PMID:26191379

  11. Biocompatible and target specific hydrophobically modified glycol chitosan nanoparticles.

    PubMed

    Yin, Wei; Li, Weiyi; Rubenstein, David A; Meng, Yizhi

    2016-01-01

    Cardiovascular disease is the leading cause of death in the United States. Atherosclerosis is a major cause for cardiovascular diseases. Drugs that treat atherosclerosis usually act nonspecifically. To enhance drug delivery specificity, the authors developed a hydrophobically modified glycol chitosan (HGC) nanoparticle that can specifically target activated endothelial cells. The biocompatibility of these nanoparticles toward red blood cells and platelets was evaluated through hemolysis, platelet activation, platelet thrombogenicity, and platelet aggregation assays. The biocompatibility of these nanoparticles toward vascular endothelial cells was evaluated by their effects on endothelial cell growth, metabolic activity, and activation. The results demonstrated that HGC nanoparticles did not cause hemolysis, or affect platelet activation, thrombogenicity, and aggregation capability in vitro. The nanoparticles did not impair vascular endothelial cell growth or metabolic activities in vitro, and did not cause cell activation either. When conjugated with intercellular adhesion molecular 1 antibodies, HGC nanoparticles showed a significantly increased targeting specificity toward activated endothelial cells. These results suggested that HGC nanoparticles are likely compatible toward red blood cells, platelets, and endothelial cells, and they can be potentially used to identify activated endothelial cells at atherosclerotic lesion areas within the vasculature, and deliver therapeutic drugs.

  12. Biodegradation of propylene glycol and associated hydrodynamic effects in sand.

    PubMed

    Bielefeldt, Angela R; Illangasekare, Tissa; Uttecht, Megan; LaPlante, Rosanna

    2002-04-01

    At airports around the world, propylene glycol (PG) based fluids are used to de-ice aircraft for safe operation. PG removal was investigated in 15-cm deep saturated sand columns. Greater than 99% PG biodegradation was achieved for all flow rates and loading conditions tested, which decreased the hydraulic conductivity of the sand by 1-3 orders of magnitude until a steady-state minimum was reached. Under constant loading at 120 mg PG/d for 15-30 d, the hydraulic conductivity (K) decreased by 2-2.5 orders of magnitude when the average linear velocity of the water was 4.9-1.4 cm/h. Variable PG loading in recirculation tests resulted in slower conductivity declines and lower final steady-state conductivity than constant PG feeding. After significant sand plugging, endogenous periods of time without PG resulted in significant but partial recovery of the original conductivity. Biomass growth also increased the dispersivity of the sand. PMID:12044070

  13. Compressive Strength of Mineral Trioxide Aggregate with Propylene Glycol

    PubMed Central

    Ghasemi, Negin; Rahimi, Saeed; Shahi, Shahriar; Salem Milani, Amin; Rezaei, Yashar; Nobakht, Mahnaz

    2016-01-01

    Introduction: The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral trioxide aggregate (MTA) liquid with volume ratio of 20% on the compressive strength (CS) of MTA in two time periods (4 and 21 days) after mixing. Methods and Materials: Four groups of steel cylinders (n=15) with an internal diameter of 3 and a height of 6 mm were prepared and MTA (groups 1 and 2) and MTA+PG (80% MTA liquid+20% PG) (groups 3 and 4) were placed in to the cylinders. In groups 1 and 3 the CS was evaluated after 4 days and in groups 2 and 4 after 21 days. Data were calculated using the two-ways ANOVA. The level of significance was set at 0.05. Results: The highest (52.22±18.92 MPa) and lowest (4.5±0.67 MPa) of CS was obtained in 21-day MTA samples and 4-day MTA+PG specimen, respectively. The effect of time and PG were significant on the CS (P<0.05). Mixing MTA with PG significantly reduced the CS; but passing the time from 4 to 21 days significantly increased the CS. Conclusion: Considering the limitations of this study, PG had a negative effect on CS of MTA. PMID:27790264

  14. Method for determination of polyethylene glycol molecular weight.

    PubMed

    Pihlasalo, Sari; Hänninen, Pekka; Härmä, Harri

    2015-04-01

    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.

  15. Theoretical studies on the unimolecular decomposition of ethylene glycol.

    PubMed

    Ye, Lili; Zhao, Long; Zhang, Lidong; Qi, Fei

    2012-01-12

    The unimolecular decomposition processes of ethylene glycol have been investigated with the QCISD(T) method with geometries optimized at the B3LYP/6-311++G(d,p) level. Among the decomposition channels identified, the H(2)O-elimination channels have the lowest barriers, and the C-C bond dissociation is the lowest-energy dissociation channel among the barrierless reactions (the direct bond cleavage reactions). The temperature and pressure dependent rate constant calculations show that the H(2)O-elimination reactions are predominant at low temperature, whereas at high temperature, the direct C-C bond dissociation reaction is dominant. At 1 atm, in the temperature range 500-2000 K, the calculated rate constant is expressed to be 7.63 × 10(47)T(-10.38) exp(-42262/T) for the channel CH(2)OHCH(2)OH → CH(2)CHOH + H(2)O, and 2.48 × 10(51)T(-11.58) exp(-43593/T) for the channel CH(2)OHCH(2)OH → CH(3)CHO + H(2)O, whereas for the direct bond dissociation reaction CH(2)OHCH(2)OH → CH(2)OH + CH(2)OH the rate constant expression is 1.04 × 10(71)T(-16.16) exp(-52414/T).

  16. Polyethylene glycol improves phenol removal by immobilized turnip peroxidase.

    PubMed

    Quintanilla-Guerrero, F; Duarte-Vázquez, M A; García-Almendarez, B E; Tinoco, R; Vazquez-Duhalt, R; Regalado, C

    2008-12-01

    Purified peroxidase from turnip (Brassica napus L. var. esculenta D.C.) was immobilized by entrapment in spheres of calcium alginate and by covalent binding to Affi-Gel 10. Both immobilized Turnip peroxidase (TP) preparations were assayed for the detoxification of a synthetic phenolic solution and a real wastewater effluent from a local paints factory. The effectiveness of phenolic compounds (PC's) removal by oxidative polymerization was evaluated using batch and recycling processes, and in the presence and in the absence of polyethylene glycol (PEG). The presence of PEG enhances the operative TP stability. In addition, reaction times were reduced from 3h to 10 min, and more effective phenol removals were achieved when PEG was added. TP was able to perform 15 reaction cycles with a real industrial effluent showing PC's removals >90% PC's during the first 10 reaction cycles. High PC's removal efficiencies (>95%) were obtained using both immobilized preparations at PC's concentrations <1.2mM. Higher PC's concentrations decreased the removal efficiency to 90% with both preparations after the first reaction cycle, probably due to substrate inhibition. On the other hand, immobilized TP showed increased thermal stability when compared with free TP. A large-scale enzymatic process for industrial effluent treatment is expected to be developed with immobilized TP that could be stable enough to make the process economically feasible. PMID:18502120

  17. Immediate-type hypersensitivity to polyethylene glycols: a review.

    PubMed

    Wenande, E; Garvey, L H

    2016-07-01

    Polyethylene glycols (PEGs) or macrogols are polyether compounds widely used in medical and household products. Although generally considered biologically inert, cases of mild to life-threatening immediate-type PEG hypersensitivity are reported with increasing frequency. Nevertheless, awareness of PEG's allergenic potential remains low, due to a general lack of suspicion towards excipients and insufficient product labelling. Information on immediate-type reactions to PEG is limited to anecdotal reports, and the potential for PEG sensitization and cross-sensitization to PEGylated drugs and structurally related derivatives is likely underestimated. Most healthcare professionals have no knowledge of PEG and thus do not suspect PEG's as culprit agents in hypersensitivity reactions. In consequence, patients are at risk of misdiagnosis and commonly present with a history of repeated, severe reactions to a range of unrelated products in hospital and at home. Increased awareness of PEG prevalence, PEG hypersensitivity, and improved access to PEG allergy testing, should facilitate earlier diagnosis and reduce the risk of inadvertent re-exposure. This first comprehensive review provides practical information for allergists and other healthcare professionals by describing the clinical picture of 37 reported cases of PEG hypersensitivity since 1977, summarizing instances where PEG hypersensitivity should be considered and proposing an algorithm for diagnostic management. PMID:27196817

  18. Aerobic biodegradation of propylene glycol by soil bacteria.

    PubMed

    Toscano, Giuseppe; Cavalca, Lucia; Letizia Colarieti, M; Scelza, Rosalia; Scotti, Riccardo; Rao, Maria A; Andreoni, Vincenza; Ciccazzo, Sonia; Greco, Guido

    2013-09-01

    Propylene glycol (PG) is a main component of aircraft deicing fluids and its extensive use in Northern airports is a source of soil and groundwater contamination. Bacterial consortia able to grow on PG as sole carbon and energy source were selected from soil samples taken along the runways of Oslo Airport Gardermoen site (Norway). DGGE analysis of enrichment cultures showed that PG-degrading populations were mainly composed by Pseudomonas species, although Bacteroidetes were found, as well. Nineteen bacterial strains, able to grow on PG as sole carbon and energy source, were isolated and identified as different Pseudomonas species. Maximum specific growth rate of mixed cultures in the absence of nutrient limitation was 0.014 h(-1) at 4 °C. Substrate C:N:P molar ratios calculated on the basis of measured growth yields are in good agreement with the suggested values for biostimulation reported in literature. Therefore, the addition of nutrients is suggested as a suitable technique to sustain PG aerobic degradation at the maximum rate by autochthonous microorganisms of unsaturated soil profile.

  19. Natural and enhanced biodegradation of propylene glycol in airport soil.

    PubMed

    Toscano, Giuseppe; Colarieti, M Letizia; Anton, Attila; Greco, Guido; Biró, Borbála

    2014-01-01

    Aircraft de-icing fluids (ADF) are a source of water and soil pollution in airport sites. Propylene glycol (PG) is a main component in several commercial formulations of ADFs. Even though PG is biodegradable in soil, seasonal overloads may result in occasional groundwater contamination. Feasibility studies for the biostimulation of PG degradation in soil have been carried out in soil slurries, soil microcosms and enrichment cultures with and without the addition of nutrients (N and P sources, oligoelements), alternative electron acceptors (nitrate, oxygen releasing compounds) and adsorbents (activated carbon). Soil samples have been taken from the contaminated area of Gardermoen Airport Oslo. Under aerobic conditions and in the absence of added nutrients, no or scarce biomass growth is observed and PG degradation occurs by maintenance metabolism at constant removal rate by the original population of PG degraders. With the addition of nutrient, biomass exponential growth enhances aerobic PG degradation also at low temperatures (4 ° C) that occur at the high season of snowmelt. Anaerobic PG degradation without added nutrients still proceeds at constant rate (i.e. no biomass growth) and gives rise to reduced fermentation product (propionic acid, reduced Fe and Mn, methane). The addition of nitrate does not promote biomass growth but allows full PG mineralization without reduced by-products. Further exploitation on the field is necessary to fully evaluate the effect of oxygen releasing compounds and adsorbents.

  20. Urinary oxalate and glycolate excretion and plasma oxalate concentration.

    PubMed Central

    Barratt, T M; Kasidas, G P; Murdoch, I; Rose, G A

    1991-01-01

    The diagnosis of primary hyperoxaluria in young children is hampered by the lack of a reliable reference range for urinary oxalate excretion, especially in infants. We present data on urinary oxalate and glycolate excretion in 137 normal children, on the plasma oxalate concentration in 33 normal children and 53 with chronic renal failure, and on amniotic fluid oxalate concentration in 63 uncomplicated pregnancies. The urinary oxalate:creatinine molar ratios were log normally distributed: mean (range) values were less than 1 year 0.061 (0.015-0.26), 1-5 years 0.036 (0.011-0.12), 5-12 years 0.030 (0.0059-0.15), and greater than 12 years 0.013 (0.0021-0.083). Geometric mean (range) plasma oxalate concentration in the normal children was 1.53 (0.78-3.02) mumols/l and was independent of age. The mean (SD) plasma oxalate: creatinine molar ratio in these normal children and 50 with chronic renal failure was 0.033 (0.013), and was independent of age and renal function. Mean (SD) amniotic fluid oxalate concentration was 19.0 (4.3) mumols/l. PMID:2031609

  1. Physicochemical characterization of nimodipine-polyethylene glycol solid dispersion systems.

    PubMed

    Barmpalexis, Panagiotis; Kachrimanis, Kyriakos; Georgarakis, Emanouil

    2014-07-01

    This study investigates the solid-solid interactions between nimodipine (NIM) and polyethylene glycol (PEG) of different mean molecular weights (PEG 2000, 4000 and 6000), in solid dispersion systems, applying differential scanning calorimetry (DSC), Fourier-Transform infrared spectroscopy, powder X-ray diffraction (PXRD), hot stage microscopy (HSM) and theoretical modeling by the Flory-Huggins (FH) solution theory. Phase diagrams constructed with the aid of DSC and FH solution theory showed sensitivity on the estimated values of the FH interaction parameter (χ). When χ is considered a constant number (χ = α, α ≠ 0), formation of a eutectic mixture is predicted in the 70-80% w/w PEG concentration region, while when χ was considered as a function of concentration and temperature (χ = f(φ,Τ)), the model predicts the formation of monotectic systems. Construction of more precise phase diagrams by HSM to the aid of Kofler's "contact preparation" method confirmed the monotectic nature of the examined systems. Studies on NIM's re-crystallization process in the solid dispersions revealed a strong dependence of the crystallization rate, as well as the resulting crystal form, on the mean molecular weight and concentration of PEG: NIM crystallization rates decrease as PEG's MW increases, while NIM mod II crystals predominate in dispersions prepared at temperatures above NIM's liquidus and growth of NIM mod I prevailing in PEG-rich samples.

  2. Polyethylene glycol protects primary hepatocytes during supercooling preservation.

    PubMed

    Puts, C F; Berendsen, T A; Bruinsma, B G; Ozer, Sinan; Luitje, Martha; Usta, O Berk; Yarmush, M L; Uygun, K

    2015-08-01

    Cold storage (at 4°C) offers a compromise between the benefits and disadvantages of cooling. It allows storage of organs or cells for later use that would otherwise quickly succumb to warm ischemia, but comprises cold ischemia that, when not controlled properly, can result in severe damage as well by both similar and unique mechanisms. We hypothesized that polyethylene glycol (PEG) 35 kDa would ameliorate these injury pathways and improve cold primary hepatocyte preservation. We show that reduction of the storage temperature to below zero by means of supercooling, or subzero non-freezing, together with PEG supplementation increases the viable storage time of primary rat hepatocytes in University of Wisconsin (UW) solution from 1 day to 4 days. We find that the addition of 5% PEG 35 kDa to the storage medium prevents cold-induced lipid peroxidation and maintains hepatocyte viability and functionality during storage. These results suggest that PEG supplementation in combination with supercooling may enable a more optimized cell and organ preservation.

  3. Coarse-grained models for aqueous polyethylene glycol solutions.

    PubMed

    Choi, Eunsong; Mondal, Jagannath; Yethiraj, Arun

    2014-01-01

    A new coarse-grained force field is developed for polyethylene glycol (PEG) in water. The force field is based on the MARTINI model but with the big multipole water (BMW) model for the solvent. The polymer force field is reparameterized using the MARTINI protocol. The new force field removes the ring-like conformations seen in simulations of short chains with the MARTINI force field; these conformations are not observed in atomistic simulations. We also investigate the effect of using parameters for the end-group that are different from those for the repeat units, with the MARTINI and BMW/MARTINI models. We find that the new BMW/MARTINI force field removes the ring-like conformations seen in the MARTINI models and has more accurate predictions for the density of neat PEG. However, solvent-separated-pairs between chain ends and slow dynamics of the PEG reflect its own artifacts. We also carry out fine-grained simulations of PEG with bundled water clusters and show that the water bundling can lead to ring-like conformations of the polymer molecules. The simulations emphasize the pitfalls of coarse-graining several molecules into one site and suggest that polymer-solvent systems might be a stringent test for coarse-grained force fields. PMID:24350686

  4. Diminution of phagocytosed perfluorocarbon emulsions using perfluoroalkylated polyethylene glycol surfactant.

    PubMed

    Hsu, Y C; Peng, C A

    2001-05-18

    Perfluorocarbon emulsions have been considered as potential blood substitutes for years due to their high capacity of dissolving respiratory oxygen and carbon dioxide. However, they have been reported to associate with side effects (e.g., flu-like syndrome) after being injected into animal's bloodstream. The cause of these side effects is related to the phagocytosis of perfluorocarbon emulsions by cells (e.g., macrophages). Inspired by the approach of using polyethylene glycol (PEG) to camouflage liposomes, we synthesized a perfluoroalkylated PEG (R(F)-PEG) surfactant to provide steric hindrance for decreasing phagocytosis of perfluorocarbon emulsions. The R(F)-PEG surfactant along with Pluronic F-68 and egg yolk phospholipid mediated perfluorocarbon emulsions were incubated individually with J774A.1 macrophages to examine the degree of phagocytosis. 19F NMR studies were used to quantitatively determine the amount of perfluorocarbon emulsions phagocytosed by macrophages. Results showed that the degree of phagocytosis was diminished to a large extent for perfluorocarbon microparticles emulsified by the R(F)-PEG surfactant. PMID:11350051

  5. Fluoroalkylated polyethylene glycol as potential surfactant for perfluorocarbon emulsion.

    PubMed

    Peng, C A; Hsu, Y C

    2001-11-01

    So far, perfluorocarbon (PFC) emulsions have been manufactured based mainly on two surfactants, Pluronic F-68 and egg yolk phospholipids (EYP) for clinical use. However, they have been documented to induce inflammatory or allergic responses when PFC emulsions were injected into human bloodstream. The cause of these side effects is associated with the phagocytosis of emulsified PFC microparticles by cells such as macrophages. In order to lessen the side effects, it is logic to develop surfactants, which are more phagocytosis-resistant and biocompatible. In this study, a perfluoroalkylated polyethylene glycol (R(F)-PEG) surfactant was synthesized by reacting perfluorooctanoyl chloride (C7F15COCl) with PEG of molecular weigh 8000. Both R(F)-PEG 8000 and EYP were used to make PFC emulsions separately by an ultrasonic homogenizer. Individual PFC emulsions were then incubated with mouse macrophage J774A.1 cells to examine the degree of phagocytosis. From microscopic observation of cell morphology, our results showed that the process of phagocytosis was retarded to a large extend using the R(F)-PEG surfactant. We also harnessed 19F-NMR to quantitatively detect the amount of PFC emulsions phagocytosed by J774A.1 cells. 19F-NMR result was consistent with the qualitative microscopic observation aforementioned. PMID:11795633

  6. Ethylene glycol ethers induce oxidative stress in the rat brain.

    PubMed

    Pomierny, Bartosz; Krzyżanowska, Weronika; Smaga, Irena; Pomierny-Chamioło, Lucyna; Stankowicz, Piotr; Budziszewska, Bogusława

    2014-11-01

    Ethylene glycol ethers (EGEs) are components of many industrial and household products. Their hemolytic and gonadotoxic effects are relatively well known while their potential adverse effects on the central nervous system have not yet been clearly demonstrated. The aim of the present study was to examine the effects of 4-week administration of 2-buthoxyethanol (BE), 2-phenoxyethanol (PHE) and 2-ethoxyethanol (EE) on the total antioxidant capacity, activity of some antioxidant enzymes, such as the superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX) and glutathione reductase and lipid peroxidation in the frontal cortex and hippocampus in the rat. These studies showed that BE and PHE decreased the total antioxidant activity, SOD and GPX activity, while increased lipid peroxidation in the frontal cortex. Like in the frontal cortex, also in the hippocampus BE and PHE attenuated the total antioxidant activity, however, lipid peroxidation was increased only in animals which received BE while reduction in GPX activity was present in rats administered PHE. The obtained data indicated that 4-week administration of BE and PHE, but not EE, reduced the total antioxidant activity and enhanced lipid peroxidation in the brain. In the frontal cortex, adverse effects of PHE and BE on lipid peroxidation probably depended on reduction in SOD and GPX activity, however, in the hippocampus the changes in the total antioxidant activity and lipid peroxidation were not connected with reduction of the investigated antioxidant enzyme activity.

  7. Optical clearing of skin tissue ex vivo with polyethylene glycol

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    Alterations of the optical and structural (weight, thickness, and square) parameters of skin caused by polyethylene glycol (PEG) with molecular weights of 300 and 400 Da were studied experimentally. The objects of the study were ex vivo skin samples of albino laboratory rats. Collimated transmittance of the skin was measured in the wavelength range 500-900 nm. As a result of exposure to the agents, an increase in the collimated transmittance and a decrease in weight, thickness, and square of skin samples were observed. Analysis of the kinetics of parameters alterations allowed us to measure the diffusion coefficient of the agents in the skin as (1.83 ± 2.22) × 10-6 and (1.70 ± 1.47) × 10-6 cm2/s for PEG-300 and PEG-400, respectively, and the rate of alterations of the structural parameters. The results obtained in this study can be used for the improvement of existing and development of new methods of noninvasive diagnostics and therapy of subcutaneous diseases.

  8. The study of gamma irradiation effects on poly (glycolic acid)

    NASA Astrophysics Data System (ADS)

    Rao Nakka, Rajeswara; Rao Thumu, Venkatappa; Reddy SVS, Ramana; Rao Buddhiraju, Sanjeeva

    2015-05-01

    We have investigated the effects of gamma irradiation on chemical structure, thermal and morphological properties of biodegradable semi-crystalline poly (glycolic acid) (PGA). PGA samples were subjected to irradiation treatment using a 60Co gamma source with a delivered dose of 30, 60 and 90 kGy, respectively. Gamma irradiation induces cleavage of PGA main chains forming ∼OĊH2 and ĊH2COO∼ radicals in both amorphous and crystalline regions. The free radicals formed in the amorphous region abstract atmospheric oxygen and convert them to peroxy radicals. The peroxy radical causes chain scission at the crystal interface through hydrogen abstraction from methylene groups forming the ∼ĊHCOO∼ (I) radical. Consequently, the observed electron spin resonance (ESR) doublet of irradiated PGA is assigned to (I). The disappearance of the ESR signal above 190°C indicates that free radicals are formed in the amorphous region and decay below the melting temperature of PGA. Fourier transform infrared and optical absorption studies confirm that the ? groups are not influenced by gamma irradiation. Differential scanning calorimetry (DSC) studies showed that the melting temperature of PGA decreased from 212°C to 202°C upon irradiation. Degree of crystallinity increased initially and then decreased with an increase in radiation as per DSC and X-ray diffraction studies. Irradiation produced changes in the physical properties of PGA as well as affecting the morphology of the material.

  9. Amended safety assessment of formaldehyde and methylene glycol as used in cosmetics.

    PubMed

    Boyer, Ivan J; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2013-01-01

    Formaldehyde and methylene glycol may be used safely in cosmetics if established limits are not exceeded and are safe for use in nail hardeners in the present practices of use and concentration, which include instructions to avoid skin contact. In hair-smoothing products, however, in the present practices of use and concentration, formaldehyde and methylene glycol are unsafe. Methylene glycol is continuously converted to formaldehyde, and vice versa, even at equilibrium, which can be easily shifted by heating, drying, and other conditions to increase the amount of formaldehyde. This rapid, reversible formaldehyde/methylene glycol equilibrium is distinguished from the slow, irreversible release of formaldehyde resulting from the so-called formaldehyde releaser preservatives, which are not addressed in this safety assessment (formaldehyde releasers may continue to be safely used in cosmetics at the levels established in their individual Cosmetic Ingredient Review safety assessments). PMID:24335968

  10. Formaldehyde and methylene glycol equivalence: critical assessment of chemical and toxicological aspects.

    PubMed

    Golden, R; Valentini, M

    2014-07-01

    Due largely to the controversy concerning the potential human health effects from exposure to formaldehyde gas in conjunction with the misunderstanding of the well-established equilibrium relationship with its hydrated reaction product, methylene glycol, the concept of chemical equivalence between these two distinctly different chemicals has been adopted by regulatory authorities. Chemical equivalence implies not only that any concentration of methylene glycol under some condition of use would be nearly or completely converted into formaldehyde gas, but also that these two substances would be toxicologically equivalent as well. A relatively simple worst case experiment using 37% formalin (i.e., concentrated methylene glycol) dispels the concept of chemical equivalence and a review of relevant literature demonstrates that methylene glycol has no inherent toxicity apart from whatever concentration of formaldehyde that might be present in equilibrium with such solutions.

  11. Methane production from glycolate excreting algae as a new concept in the production of biofuels.

    PubMed

    Günther, Anja; Jakob, Torsten; Goss, Reimund; König, Swetlana; Spindler, Daniel; Räbiger, Norbert; John, Saskia; Heithoff, Susanne; Fresewinkel, Mark; Posten, Clemens; Wilhelm, Christian

    2012-10-01

    It is the aim of the present work to introduce a new concept for methane production by the interaction of a glycolate-excreting alga (Chlamydomonas reinhardtii) and methanogenic microbes operating in separate compartments within one photobioreactor. This approach requires a minimum number of metabolic steps to convert light energy to methane thereby reducing the energetic and financial costs of biomass formation, harvest and refinement. In this feasibility study it is shown that the physiological limitations for sustained glycolate production can be circumvented by the use of C. reinhardtii mutants whose carbon concentrating mechanisms or glycolate dehydrogenase are suppressed. The results also demonstrate that methanogenic microbes are able to thrive on glycolate as single carbon source for a long time period, delivering biogas composed of CO(2)/methane with only very minor contamination.

  12. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (External Review Draft)

    EPA Science Inventory

    EPA has conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of ethylene glycol monobutyl ether that will appear on the Integrated Risk Information System (IRIS) database.

  13. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    SciTech Connect

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  14. Heat-transfer tests of aqueous ethylene glycol solutions in an electrically heated tube

    NASA Technical Reports Server (NTRS)

    Bernardo, Everett; Eian, Carroll S

    1945-01-01

    As part of an investigation of the cooling characteristics of liquid-cooled engines, tests were conducted with an electrically heated single-tube heat exchanger to determine the heat-transfer characteristics of an-e-2 ethylene glycol and other ethylene glycol-water mixtures. Similar tests were conducted with water and commercial butanol (n-butyl alcohol) for check purposes. The results of tests conducted at an approximately constant liquid-flow rate of 0.67 pound per second (Reynolds number, 14,500 to 112,500) indicate that at an average liquid temperature 200 degrees f, the heat-transfer coefficients obtained using water, nominal (by volume) 30 percent-70 percent and 70 percent-30 percent glycol-water mixtures are approximately 3.8, 2.8, and 1.4 times higher, respectively, than the heat-transfer coefficients obtained using an-e-2 ethylene glycol.

  15. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD.... Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance when used in foliar applications to peanut plants....

  16. Clinical Features of Reported Ethylene Glycol Exposures in the United States

    PubMed Central

    Jobson, Meghan A.; Hogan, Susan L.; Maxwell, Colin S.; Hu, Yichun; Hladik, Gerald A.; Falk, Ronald J.; Beuhler, Michael C.; Pendergraft, William F.

    2015-01-01

    Background Ethylene glycol is highly toxic and represents an important cause of poisonings worldwide. Toxicity can result in central nervous system dysfunction, cardiovascular compromise, elevated anion gap metabolic acidosis and acute kidney injury. Many states have passed laws requiring addition of the bittering agent, denatonium benzoate, to ethylene glycol solutions to reduce severity of exposures. The objectives of this study were to identify differences between unintentional and intentional exposures and to evaluate the utility of denatonium benzoate as a deterrent. Methods and Findings Using the National Poison Data System, we performed a retrospective analysis of reported cases of ethylene glycol exposures from January 2006 to December 2013. Outcome classification was summed for intentionality and used as a basis for comparison of effect groups. There were 45,097 cases of ethylene glycol exposures resulting in 154 deaths. Individuals more likely to experience major effects or death were older, male, and presented with more severe symptoms requiring higher levels of care. Latitude and season did not correlate with increased exposures; however, there were more exposures in rural areas. Denatonium benzoate use appeared to have no effect on exposure severity or number. Conclusion Deaths due to ethylene glycol exposure were uncommon; however, there were major clinical effects and more exposures in rural areas. Addition of denatonium benzoate was not associated with a reduction in exposures. Alternative means to deter ingestion are needed. These findings suggest the need to consider replacing ethylene glycol with alternative and less toxic agents. PMID:26566024

  17. Effect of glycol-based coolants on the suppression and recovery of platinum fuel cell electrocatalysts

    NASA Astrophysics Data System (ADS)

    Garsany, Yannick; Dutta, Sreya; Swider-Lyons, Karen E.

    2012-10-01

    We use cyclic and rotating disk electrode voltammetry to study glycol-based coolant formulations to show that individual constituents have either negligible or significant poisoning effects on the nanoscale Pt/carbon catalysts used in proton exchange membrane fuel cells. The base fluid in all these coolants is glycol (1, 3 propanediol), commercially available in a BioGlycol coolant formulation with an ethoxylated nonylphenol surfactant, and azole- and polyol-based non-ionic corrosion inhibitors. Exposure of a Pt/Vulcan carbon electrode to glycol-water or glycol-water-surfactant mixtures causes the loss of Pt electrochemical surface area (ECSA), but the Pt ECSA is fully recovered in clean electrolyte. Only mixtures with the azole corrosion inhibitor cause irreversible losses to the Pt ECSA and oxygen reduction reaction (ORR) activity. The Pt ECSA and ORR activity can only be recovered to within 70% of its initial values after aggressive voltammetric cycling to 1.50 V after azole poisoning. When poisoned with a glycol mixture containing the polyol corrosion inhibitor instead, the Pt ECSA and ORR activity is completely recovered by exposure to a clean electrolyte. The results suggest that prior to incorporation in a fuel cell, voltammetric evaluation of the constituents of coolant formulations is worthwhile.

  18. International industry initiatives to improve the glycol ether health effects knowledge base.

    PubMed

    Boatman, R J

    2005-03-28

    Following the recognition in the early 1980s of the potential reproductive hazards of certain glycol ethers, industry organizations were formed in the US and Europe having a number of stated goals to: (1) provide hazard information by expanding the toxicity database for glycol ethers; (2) promote cooperation among scientists, governmental authorities, and industry; and (3) promote scientifically sound regulatory actions and to assist in the setting of scientifically defensible safety standards. This effort led to early recommendations that EGME, EGEE, and their acetates be removed from consumer products. Also, studies conducted by industry under US EPA test rules have led to a better understanding of the hazards associated with glycol ether constituents of brake fluids, paints, and other products. Industry-provided information has greatly assisted the setting of occupational and public safety standards in a number of countries. Hazard assessments for a number of large-volume glycol ethers have been performed under the OECD SIDS program. This work continues with the industry-funded ICCA/HPV testing initiative. To provide sound risk assessment data, industry continues to sponsor basic research aimed at better understanding human versus mouse versus rat sensitivities to certain glycol ethers. Industry has also prepared and supported the publication of toxicological data compendia for glycol ethers. PMID:15705486

  19. The "New Polyethylene Glycol Dilemma": Polyethylene Glycol Impurities and Their Paradox Role in mAb Crystallization.

    PubMed

    Hildebrandt, Christian; Joos, Lea; Saedler, Rainer; Winter, Gerhard

    2015-06-01

    Polyethylene glycols (PEG) represent the most successful and frequently applied class of excipients used for protein crystallization. PEG auto-oxidation and formation of impurities such as peroxides and formaldehydes that foster protein drug degradation is known. However, their effect on mAb crystallization has not been studied in detail before. During the present study, a model IgG1 antibody (mAb1) was crystallized in PEG solutions. Aggregate formation was observed during crystallization and storage that was ascribed to PEG degradation products. Reduction of peroxide and formaldehyde levels prior to crystallization by vacuum and freeze-drying was investigated for its effect on protein degradation. Vacuum drying was superior in removal of peroxides but inferior in reducing formaldehyde residues. Consequently, double purification allowed extensive removal of both impurities. Applying of purified PEG led to 50% lower aggregate fractions. Surprisingly, PEG double purification or addition of methionine prior to crystallization prevented crystal formation. With increased PEG concentration or spiking with peroxides and formaldehydes, crystal formation could be recovered again. With these results, we demonstrate that minimum amounts of oxidizing impurities and thus in consequence chemically altered proteins are vital to initiate mAb1 crystallization. The present study calls PEG as good precipitant for therapeutic biopharmaceuticals into question.

  20. Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions.

    PubMed

    Wei, Y-Z; Zhuo, R-X; Jiang, X-L

    2016-05-20

    The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns. PMID:27102303

  1. A facile synthesis of azido-terminated heterobifunctional poly(ethylene glycol)s for "click" conjugation.

    PubMed

    Hiki, Shigehiro; Kataoka, Kazunori

    2007-01-01

    New azido-terminated heterobifunctional poly(ethylene glycol) (PEG) derivatives having primary amine and carboxyl end groups, (Azide-PEG-NH 2 and Azide-PEG-COOH, respectively) were synthesized with high efficiency. An alpha-allyl-omega-hydroxyl PEG was prepared as the first step to Azide-PEG-X (X = NH 2 and COOH) through the ring-opening polymerization of ethylene oxide (EO) with allyl alcohol as an initiator, followed by two-step modification of the hydroxyl end to an azido group. To introduce primary amino or carboxyl functional groups, amination and carboxylation reactions of the allyl terminal ends was then conducted by a radical addition of thiol compounds. Molecular functionalities of both ends of the PEG derivatives thus prepared were characterized by (1)H, (13)C NMR, and MALDI-TOF MS spectra, validating that the reaction proceeded quantitatively. The terminal azido functionality is available to conjugate various ligands with an alkyne group through the 1,3-dipolar cycloaddition reaction condition ("click chemistry").

  2. Versatile and selective synthesis of "click chemistry" compatible heterobifunctional poly(ethylene glycol)s possessing azide and alkyne functionalities.

    PubMed

    Hiki, Shigehiro; Kataoka, Kazunori

    2010-02-17

    Versatile route for "click chemistry" compatible heterobifunctional PEGs was established through preparation of alpha-tetrahydropyranyloxy-omega-hydroxyl poly(ethylene glycol) (THP-PEG-OH) via ring-opening polymerization of ethylene oxide using 2-(tetrahydro-2H-pyran-2-yloxy)ethanol as an initiator, followed by the functionalization of omega-OH group to either the azido or alkyne group. Quantitative azidation of THP-PEG-OH was confirmed from the analysis of molecular functionality of the derivatives. While the conversion efficiency of omega-alkynation was appropriately 70%, the unreacted THP-PEG-OH fraction was successfully removed by ion-exchange chromatography after the carboxylation of the hydroxyl group with succinic anhydride. Then, the protecting group of the alpha-end, THP, was removed in mild acidic media, followed by two- or three-step modification of the resulting alpha-hydroxyl group to primary amino or thiol groups. Consequently, "click chemistry" compatible heterobifunctional PEG derivatives (X-PEG-Y; X = NH(2) and SH, Y =Azide and Alkyne) were synthesized with high efficiency and controlled molecular weight.

  3. The influence of povidone K17 on the storage stability of solid dispersions of nimodipine and polyethylene glycol.

    PubMed

    Smikalla, Martina Maria; Urbanetz, Nora Anne

    2007-04-01

    Previous studies revealed that solid dispersions containing nimodipine and polyethylene glycol 2000 can be effectively prevented from recrystallization by adding povidone K17. These systems are characterized by a high dissolution rate and a remarkable supersaturation of the drug in the dissolution media. It is still unknown if these characteristics are achievable with all polyethylene glycol and povidone mixtures. The objective of the present study is to find out, whether povidone K17 has to be dissolved in melted polyethylene glycol during the preparation process of solid dispersions by the melting method in order to avoid recrystallization of the drug and to ensure storage stability. Solid dispersions consisting of 20% (m/m) nimodipine, 16% (m/m) povidone K17 and 64% (m/m) of six different mixtures of polyethylene glycol 2000 and 8000 were prepared by the melting method and investigated by dissolution testing, thermal analysis and X-ray diffraction. As the solubility of povidone K17 in polyethylene glycol 2000 is about 70% at 65 degrees C and decreases with increasing molecular weight of the polyethylene glycol, mixtures containing different amounts of dissolved povidone K17 are obtained by varying the mixing ratio of polyethylene glycol 2000 and 8000. Recrystallization is inhibited in the formulations, containing mainly polyethylene glycol 2000 whereas recrystallization occurs in systems consisting predominantly of polyethylene glycol 8000. These results show clearly that dissolution of povidone in melted polyethylene glycol is a prerequisite in order to prevent recrystallization.

  4. Enhanced incorporation of tritium into glycolate during photosynthesis by tobacco leaf tissue in the presence of tritiated water

    SciTech Connect

    Peterson, R.B.

    1982-01-01

    Tobacco (Nicotiana tabacum var. Havana Seed) leaf discs were allowed to photosynthesize for 3 to 20 minutes in the present of /sup 14/CO/sub 2/ and /sup 3/H/sub 2/O. Several metabolites of the Calvin cycle and photorespiratory pathway were isolated and purified and the /sup 3/H:/sup 14/C values measured. Glycolate had a 5- to 10-fold higher /sup 3/H:/sup 14/C than the Calvin cycle intermediate 3- phosphoglyceric acid, or its end product sucrose. The glycolate oxidase inhibitor ..cap alpha..-hydroxy-2-pyridinemethanesulfonic acid caused glycolate to accumulate in the tissue and lowered the /sup 3/H:/sup 14/C in glycolate to a value similar to that in 3-phosphoglyceric acid. Phosphoglycolate, a possible precursor of glycolate arising from the Calvin cycle, exhibited a /sup 3/H:/sup 14/C value similar 3-phosphoglyceric acid under all conditions. The finding of a /sup 3/H enrichment in glycolate suggests that another source of glycolate, possibly the reduction of glyoxylate, exists in leaf tissue. Analyses of incorporation of /sup 3/H into the pro-2R and pro-2S hydrogens of glycolate, in the presence and absence of ..cap alpha..-hydroxy-2-pyridinemethanesulfonic acid, suggest an alternative source of glycolate. Biochemical mechanisms to account for /sup 3/H enrichment into glycolate are evaluated.

  5. Myocardial Matrix-Polyethylene Glycol Hybrid Hydrogels for Tissue Engineering

    PubMed Central

    Grover, Gregory N.; Rao, Nikhil

    2014-01-01

    Similar to other protein-based hydrogels, extracellular matrix (ECM) based hydrogels, derived from decellularized tissues, have a narrow range of mechanical properties and are rapidly degraded. These hydrogels contain natural cellular adhesion sites, form nanofibrous networks similar to native ECM, and are biodegradable. In this study, we expand the properties of these types of materials by incorporating poly(ethylene glycol) (PEG) into the ECM network. We use decellularized myocardial matrix as an example of a tissue specific ECM derived hydrogel. Myocardial matrix-PEG hybrids were synthesized by two different methods, cross-linking the proteins with an amine-reactive PEG-star and photo-induced radical polymerization of two different multi-armed PEG-acrylates. We show that both methods allow for conjugation of PEG to the myocardial matrix by gel electrophoresis and infrared spectroscopy. Scanning electron microscopy demonstrated that the hybrid materials still contain a nanofibrous network similar to unmodified myocardial matrix and that the fiber diameter is changed by the method of PEG incorporation and PEG molecular weight. PEG conjugation also decreased the rate of enzymatic degradation in vitro, and increased material stiffness. Hybrids synthesized with amine-reactive PEG had gelation rates of thirty minutes, 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 four minutes upon irradiation allowing for 3D encapsulation and culture of cells, unlike the soft unmodified myocardial matrix. This work demonstrates PEG incorporation into ECM-based hydrogels can expand material properties, thereby opening up new possibilities for in vitro and in vivo applications. PMID:24334615

  6. A course-grained model for polyethylene glycol polymer

    SciTech Connect

    Nicholson, Don M; Wang, Qifei; Keffer, David J

    2011-01-01

    A coarse-grained (CG) model of polyethylene glycol (PEG) was developed and implemented in CG molecular dynamics (MD) simulations of PEG chains with degree of polymerization (DP) 20 and 40. In the model, two repeat units of PEG are grouped as one CG bead. Atomistic MD simulation of PEG chains with DP = 20 was first conducted to obtain the bonded structural probability distribution functions (PDFs) and nonbonded pair correlation function (PCF) of the CG beads. The bonded CG potentials are obtained by simple inversion of the corresponding PDFs. The CG nonbonded potential is parameterized to the PCF using both an inversion procedure based on the Ornstein-Zernike equation with the Percus-Yevick approximation (OZPY{sup -1}) and a combination of OZPY{sup -1} with the iterative Boltzmann inversion (IBI) method (OZPY{sup -1}+IBI). As a simple one step method, the OZPY{sup -1} method possesses an advantage in computational efficiency. Using the potential from OZPY{sup -1} as an initial guess, the IBI method shows fast convergence. The coarse-grained molecular dynamics (CGMD) simulations of PEG chains with DP = 20 using potentials from both methods satisfactorily reproduce the structural properties from atomistic MD simulation of the same systems. The OZPY{sup -1}+IBI method yields better agreement than the OZPY{sup -1} method alone. The new CG model and CG potentials from OZPY{sup -1}+IBI method was further tested through CGMD simulation of PEG with DP = 40 system. No significant changes are observed in the comparison of PCFs from CGMD simulations of PEG with DP = 20 and 40 systems indicating that the potential is independent of chain length.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  8. Interaction between water and poly(vinylpyrrolidone) containing polyethylene glycol.

    PubMed

    Hamaura, T; Newton, J M

    1999-11-01

    Information on the interaction between water and polymers is indispensable for manufacturing solid dispersion of a drug by hot-melt extrusion because this interaction affects various properties of the water-polymer mixtures, such as their viscoelastic properties. In this study, poly(vinylpyrrolidone) K30 (PVP) containing 0%, 10%, and 20% poly(ethylene glycol) 400 (PEG) was used as model amorphous polymers. The interaction of water with these polymers was assessed by the evaluation of the glass transition temperature (Tg), the point on the isotherm corresponding to the weight of sorbed water required to form a complete monolayer on the solid surface (apparent Wm), and the maximal amount of nonfreezing water, which were measured by differential scanning calorimetry and water sorption isotherms. In all of the systems with a water content below a certain water fraction (0.1 for PVP, 0.12 for PVP-PEG 10%, and 0.16 for PVP-PEG 20%), the Tg values were successfully predicted using theoretical equations, whereas the experimental Tg values were higher than predicted for those with a water content above these water fraction levels. In addition, these values of water fraction are similar to the apparent W(m) values determined using the Guggenheim-Anderson-DeBoer (GAB) equation (0.110, 0.117, and 0.147 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively). Nonfreezing water is detected above 0.47, 0.49, and 0.51 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively. Miscibility between water and PVP or PVP-PEG seems to change according to the water content in the system. All parameters increase with the concentration of PEG in the sample. This may be explained by the fact that PEG has a larger number of polymer repeating units, which may therefore interact with water more than PVP.

  9. Motor performance effects of propylene glycol dinitrate in the rat

    SciTech Connect

    Bogo, V.; Hill, T.A.; Nold, J.

    1987-01-01

    Propylene glycol dinitrate (PGDN), a major constituent of a liquid torpedo propellant, produces incoordination and impairment of balance in humans. This study was conducted to evaluate the rat as a model for PGDN-induced motor performance decrement, and to determine if direct application of PGDN onto neural tissue is a useful alternative to other routes of exposure. PGDN was injected onto the cisterna magna (ic) of adult Sprague-Dawley rats trained on the accelerod, a test of motor performance. Three groups of 13-14 male rats each received a single dose of either 5 or 10 microliters PGDN or 25 microliters sterile saline (control) while anesthetized with halothane. Accelerod performance was measured 12 min after ic injection, then hourly for 6 h, and at 24 h. Injections were evaluated using a five-stage screening criterion to eliminate grossly traumatized subjects, to verify the accuracy of the injection, and to determine the extent of mechanical damage. Eighteen out of 41 subjects passed the five-stage screen. A significant decrease in performance occurred during the first 2 h following injection of 10 microliters PGDN compared to the control and the 5-microliters groups. N significant differences were seen between the 5-microliter and control groups. These data confirm previous findings of PGDN-induced changes in human motor performance, suggesting that the rat may be a useful model for further PGDN neurobehavioral assessment. The data also indicate that ic injection may be an effective alternative to other routes of exposure for materials with appropriate chemical and biological properties if an evaluation screen is used.

  10. Potentiation of aquatic pollution by ethylene glycol with regard to the aquatic angiosperm, Lemna gibba

    SciTech Connect

    Thomas, D.A.; Barber, J.T.; Yatsu, L.Y.; Ensley, H.E.

    1995-12-31

    Ethylene glycol is usually thought of as a benign component of urban runoff. Thus, its EC50 value, with regard to the vegetative growth of axenically grown Lemna gibba, is relatively high, viz. 164 mM. Ethylene glycol is not metabolized by Lemna but growth is demonstrably stimulated at concentrations below 75 mM. In the presence of ethylene glycol, the fronds of duckweed are dark green, translucent and the growth medium contains gas bubbles of carbon dioxide which result from an enhanced uptake of sucrose from the growth medium and its subsequent respiration. The uptake is a non-specific effect since the uptake of various other compounds, including water, is enhanced when duckweed is grown in the presence of ethylene glycol. The increased uptake of water, sucrose, inorganic ions and organic compounds results from an increased permeability due to the creation of intercellular holes in the aerenchymatous tissues of the ethylene glycol-treated plants. The mechanism by which ethylene glycol causes the holes is unknown but may involve a disruption in lipid metabolism since the hydrophobicity of the fronds is altered and their lipid composition is changed. The significance of this phenomenon is that toxicants, just like innocuous substances, are taken up in increased amounts by treated plants and as a result their toxicities are increased with regard to duckweed as evidenced by a decrease in their effective concentrations, often of more than 3-fold. These results suggest that although ethylene glycol itself may be benign, its presence in polluted waters containing other toxicants may potentiate the effects of those pollutants.

  11. Glycol ethers--validation procedures for tube/pump and dosimeter monitoring methods.

    PubMed

    Langhorst, M L

    1984-06-01

    Methods were developed and validated for personal monitoring of exposures to airborne glycol ethers, both short-term and long-term time-weighted-averages. Either a 600 mg charcoal tube or a 780 mg silica gel tube is recommended for monitoring nine glycol ethers, depending upon the humidity and other organic compounds to be monitored. The charcoal tube allows maximum sensitivity and is unaffected by high humidity conditions. Two-phase solvent desorption with CS2 and water allows aqueous phase recoveries of DOWANOL EM, PM, EE, DM, DPM, and TM glycol ethers. DOWANOL EB, DB and TPM glycol ethers are partitioned between the two layers, necessitating chromatographic analysis of both layers. The silica gel tube method can be used to monitor all nine glycol ethers tested, but is affected by high humidity conditions, resulting in significant breakthrough of the more volatile glycol ethers. The 3M organic vapor monitor can accurately and conveniently determine exposure concentrations for DOWANOL EM, EE, and PM glycol ethers, but sensitivities may be inadequate for sampling periods less than one hour. These methods were validated at levels down to 0.1 times the Dow internal exposure guidelines for those substances with Dow exposure guidelines and well above the current ACGIH and OSHA guidelines. This paper also illustrates validation procedures for tube/pump and dosimeter methods, allowing good definition of method accuracy and precision. Some screening experiments are described for diffusional dosimeters to check the most important parameters in a minimum of time. This methodology will allow assessment of human airborne exposures relative to the new toxicology data available on animals. PMID:6331145

  12. Design and synthesis of multifunctional poly(ethylene glycol)s using enzymatic catalysis for multivalent cancer drug delivery

    NASA Astrophysics Data System (ADS)

    Seo, Kwang Su

    The objective of this research was to design and synthesize multifunctional poly(ethylene glycol)s (PEG)s using enzyme-catalyzed reactions for multivalent targeted drug delivery. Based on computer simulation for optimum folate binding, a four-arm PEG star topology with Mn = 1000 g/mol was proposed. First, a four-functional core based on tetraethylene glycol (TEG) was designed and synthesized using transesterification and Michael addition reactions in the presence of Candida antarctica lipase B (CALB) as a biocatalyst. The four-functional core (HO)2-TEG-(OH)2 core was successfully prepared by the CALB-catalyzed transesterification of vinyl acrylate (VA) with TEG and then Michael addition of diethanolamine to the resulting TEG diacrylate with/without the use of solvent. The functional PEG arms with fluorescein isothiocyanate (FITC) and folic acid (FA) were prepared using both traditional organic chemistry and enzyme-catalyzed reactions. FITC was reacted with the amine group of H2N-PEG-OH in the presence of triethylamine via nucleophilic addition onto the isothiocyanate group. Then, divinyl adipate (DVA) was transesterified with the FITC-PEG-OH product in the presence of CALB to produce the FITC-PEG vinyl ester that will be attached to the four-functional core via CALC-catalyzed transesterification. For the synthesis of FA-PEG vinyl ester arm, DVA was first reacted with PEG-monobenzyl ether (BzPEG-OH) in bulk in the presence of CALB. The BzPEG vinyl ester was then transesterified with 12-bromo-1-dodecanol in the presence of CALB. Finally, BzPEG-Br was attached to FA exclusively in the gamma position using a new method. The thesis also discusses fundamental studies that were carried out in order to get better understanding of enzyme catalyzed transesterification and Michael addition reactions. First, in an effort to investigate the effects of reagent and enzyme concentrations in transesterification, vinyl methacrylate (VMA) was reacted with 2-(hydroxyethyl) acrylate (2

  13. Carbohydrate radicals: from ethylene glycol to DNA strand breakage.

    PubMed

    von Sonntag, Clemens

    2014-06-01

    Radiation-induced DNA strand breakage results from the reactions of radicals formed at the sugar moiety of DNA. In order to elucidate the mechanism of this reaction investigations were first performed on low molecular weight model systems. Results from studies on deoxygenated aqueous solutions of ethylene glycol, 2-deoxy-d-ribose and other carbohydrates and, more relevantly, of d-ribose-5-phosphate have shown that substituents can be eliminated from the β-position of the radical site either proton and base-assisted (as in the case of the OH substituent), or spontaneously (as in the case of the phosphate substituent). In DNA the C(4') radical undergoes strand breakage via this type of reaction. In the presence of oxygen the carbon-centred radicals are rapidly converted into the corresponding peroxyl radicals. Again, low molecular weights models have been investigated to elucidate the key reactions. A typical reaction of DNA peroxyl radicals is the fragmentation of the C(4')-C(S') bond, a reaction not observed in the absence of oxygen. Although OH radicals may be the important direct precursors of the sugar radicals of DNA, results obtained with poly(U) indicate that base radicals may well be of even greater importance. The base radicals, formed by addition of the water radicals (H and OH) to the bases would in their turn attack the sugar moiety to produce sugar radicals which then give rise to strand breakage and base release. For a better understanding of strand break formation it is therefore necessary to investigate in more detail the reactions of the base radicals. For a start, the radiolysis of uracil in oxygenated solutions has been reinvestigated, and it has been shown that the major peroxyl radical in this system undergoes base-catalysed elimination of [Formula: see text], a reaction that involves the proton at N(l). In the nucleic acids the pyrimidines are bound at N(l) to the sugar moiety and this type of reaction can no longer occur. Therefore, with

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

    NASA Astrophysics Data System (ADS)

    Smith, Amanda Walker

    Heart failure is one of the leading causes of death worldwide, and the current costs of treatment put a significant economic burden on our societies. After an infarction, fibrotic tissue begins to form as part of the heart failure cascade. Current options to slow this process include a wide range of pharmaceutical agents, and ultimately the patient may require a heart transplant. Innovative treatment approaches are needed to bring down costs and improve quality of life. The possibility of regenerating or replacing damaged tissue with healthy cardiomyocytes is generating considerable excitement, but there are still many obstacles to overcome. First, while cell injections into the myocardium have demonstrated slight improvements in cardiac function, the actual engraftment of transplanted cells is very low. It is anticipated that improving engraftment will boost outcomes. Second, cellular differentiation and reprogramming protocols have not yet produced cells that are identical to adult cardiomyocytes, and immunogenicity continues to be a problem despite the advent of autologously derived induced pluripotent stem cells. This dissertation will explore biomaterials approaches to addressing these two obstacles. Tissue engineering scaffolds may improve cell engraftment by providing bioactive factors, preventing cell anoikis, and reducing cell washout by blood flow. Poly(ethylene glycol) (PEG) is often used as a coating to reduce implant rejection because it is highly resistant to protein adsorption. Because fibrosis of a material in contact with the myocardium could cause arrhythmias, PEG materials are highly relevant for cardiac tissue engineering applications. In Chapter 2, we describe a novel method for crosslinking PEG microspheres around cells to form a scaffold for tissue engineering. We then demonstrate that HL-1 cardiomyocyte viability and phenotype are retained throughout the fabrication process and during the first 7 weeks of culture. In the third chapter of the

  15. Complex microparticulate systems based on glycidyl methacrylate and xanthan.

    PubMed

    Lungan, Maria-Andreea; Popa, Marcel; Desbrieres, Jacques; Racovita, Stefania; Vasiliu, Silvia

    2014-04-15

    Porous microparticles based on glycidyl methacrylate, dimethacrylic monomers [ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate] and xanthan gum were synthesized by aqueous suspension polymerization method in the presence of toluene as diluent using two types of initiators: benzoyl peroxide and ammonium persulfate. The G microparticles based on glycidyl methacrylate and dimethacrylic monomers and X microparticles based on glycidyl methacrylate, xanthan and dimethacrylic monomers were characterized by various techniques including FT-IR spectroscopy, TG analysis, SEM analysis and DVS method. The specific surface areas were determined by DVS method, while the copolymer porosities and pore volume were obtained from the apparent and skeletal densities. The results have indicated that xanthan was included in the crosslinked matrix by means of covalent bonds. X microparticles have a porous structure with higher specific surface area (129-44 m(2)/g) and higher sorption capacities compared with G microparticles (69-31 m(2)/g). PMID:24607180

  16. [Determination of residual glycol ethers in leather and leather products by gas chromatography/mass spectrometry].

    PubMed

    Wang, Ghengyun; Zhang, Weiya; Li, Lixia; Shen, Yalei; Lin, Junfeng; Xie, Tangtang; Chu, Naiqing

    2014-08-01

    An effective method was established for the simultaneous determination of residual glycol ethers in leather and leather products by gas chromatography/mass spectrometry. Glycol ethers in leather and leather products were ultrasonically extracted at 45 °C, using ethyl acetate as the extraction solvent. The extracts were purified by solid phase extraction (SPE) columns, and then analyzed by gas chromatography/mass spectrometry in selected ion monitoring mode. The content of each analyte was calibrated by external standard method. The limit of detection of ethylene glycol ethyl ether (EGEE) was 0. 10 mg/kg under the condition of signal to noise (S/N) of 3 and the limits of the other 11 glycol ethers were all less than 0.05 mg/kg. The spiked recoveries varied from 81. 2% to 95. 5% at three different spiked levels with the relative standard deviations (RSDs) ranged from 1.4% to 6. 6%. The proposed method is simple, rapid and accurate, with the limits of detection much less than the requirements of the Regulation Concerning Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) of European Union. It is applicable to the determination of residual glycol ethers in leather and leather products, and provides a reference for the relevant testing standards.

  17. Crystallization Kinetics of Indomethacin/Polyethylene Glycol Dispersions Containing High Drug Loadings.

    PubMed

    Duong, Tu Van; Van Humbeeck, Jan; Van den Mooter, Guy

    2015-07-01

    The reproducibility and consistency of physicochemical properties and pharmaceutical performance are major concerns during preparation of solid dispersions. The crystallization kinetics of drug/polyethylene glycol solid dispersions, an important factor that is governed by the properties of both drug and polymer has not been adequately explored, especially in systems containing high drug loadings. In this paper, by using standard and modulated differential scanning calorimetry and X-ray powder diffraction, we describe the influence of drug loading on crystallization behavior of dispersions made up of indomethacin and polyethylene glycol 6000. Higher drug loading increases the amorphicity of the polymer and inhibits the crystallization of PEG. At 52% drug loading, polyethylene glycol was completely transformed to the amorphous state. To the best of our knowledge, this is the first detailed investigation of the solubilization effect of a low molecular weight drug on a semicrystalline polymer in their dispersions. In mixtures containing up to 55% indomethacin, the dispersions exhibited distinct glass transition events resulting from amorphous-amorphous phase separation which generates polymer-rich and drug-rich domains upon the solidification of supercooled polyethylene glycol, whereas samples containing at least 60% drug showed a single amorphous phase during the period in which crystallization normally occurs. The current study demonstrates a wide range in physicochemical properties of drug/polyethylene glycol solid dispersions as a result of the complex nature in crystallization of this system, which should be taken into account during preparation and storage.

  18. Oligoethylene glycol-substituted aza-BODIPY dyes as red emitting ER-probes.

    PubMed

    Kamkaew, Anyanee; Thavornpradit, Sopida; Puangsamlee, Thamon; Xin, Dongyue; Wanichacheva, Nantanit; Burgess, Kevin

    2015-08-14

    This study features aza-BODIPY (BF2-chelated azadipyrromethene) dyes with two aromatic substituents linked by oligoethylene glycol fragments to increase hydrophilicity of aza-BODIPY for applications in intracellular imaging. To prepare these, two chalcones were attached α,ω onto oligoethylene glycol fragments, then reacted with nitromethane anion. Conjugate addition products from this reaction were then subjected to typical conditions for synthesis of aza-BODIPY dyes (NH4OAc, (n)BuOH, 120 °C); formation of boracycles in this reaction was concomitant with creation of macrocycles containing the oligoethylene glycol fragments. Similar dyes with acyclic oligoelythene glycol substituents in the same position were used to compare the efficiencies of the intra- and inter-molecular aza-BODIPY forming reactions, and the characteristics of the products. All the fluors with oligoethylene glycol fragments, i.e. cyclic or acyclic, localized in the endoplasmic reticulum of a fibroblast cell line (WEHI-13VAR), the human pancreatic cancer cell line (PANC-1, rough ER predominates) and human liver cancer cell line (HepG2, smooth ER prevalent). These fluors are potentially useful for near IR (λmax emis at 730 nm) ER staining probes. PMID:26138325

  19. Viscoelasticity of repaired sciatic nerve by poly(lactic-co-glycolic acid) tubes

    PubMed Central

    Piao, Chengdong; Li, Peng; Liu, Guangyao; Yang, Kun

    2013-01-01

    Medical-grade synthetic poly(lactic-co-glycolic acid) polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly(lactic-co-glycolic acid) tubes. Ten sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly(lactic-co-glycolic acid) tubes. Stress relaxation and creep testing showed that at 7 200 seconds, the sciatic nerve anastomosed by poly(lactic-co-glycolic acid) tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly(lactic-co-glycolic acid) exhibits good viscoelasticity to meet the biomechanical require-ments for a biomaterial used to repair sciatic nerve injury. PMID:25206634

  20. Oligoethylene glycol-substituted aza-BODIPY dyes as red emitting ER-probes.

    PubMed

    Kamkaew, Anyanee; Thavornpradit, Sopida; Puangsamlee, Thamon; Xin, Dongyue; Wanichacheva, Nantanit; Burgess, Kevin

    2015-08-14

    This study features aza-BODIPY (BF2-chelated azadipyrromethene) dyes with two aromatic substituents linked by oligoethylene glycol fragments to increase hydrophilicity of aza-BODIPY for applications in intracellular imaging. To prepare these, two chalcones were attached α,ω onto oligoethylene glycol fragments, then reacted with nitromethane anion. Conjugate addition products from this reaction were then subjected to typical conditions for synthesis of aza-BODIPY dyes (NH4OAc, (n)BuOH, 120 °C); formation of boracycles in this reaction was concomitant with creation of macrocycles containing the oligoethylene glycol fragments. Similar dyes with acyclic oligoelythene glycol substituents in the same position were used to compare the efficiencies of the intra- and inter-molecular aza-BODIPY forming reactions, and the characteristics of the products. All the fluors with oligoethylene glycol fragments, i.e. cyclic or acyclic, localized in the endoplasmic reticulum of a fibroblast cell line (WEHI-13VAR), the human pancreatic cancer cell line (PANC-1, rough ER predominates) and human liver cancer cell line (HepG2, smooth ER prevalent). These fluors are potentially useful for near IR (λmax emis at 730 nm) ER staining probes.

  1. Oligoethylene Glycol-substituted Aza-BODIPY Dyes As Red Emitting ER-Probes

    PubMed Central

    Kamkaew, Anyanee; Thavornpradit, Sopida; Puangsamlee, Thamon; Xin, Dongyue; Wanichacheva, Nantanit; Burgess, Kevin

    2015-01-01

    This study features aza-BODIPY (BF2-chelated azadipyrromethene) dyes with two aromatic substituents linked by oligoethylene glycol fragments to increase hydrophilicity of aza-BODIPY for applications in intracellular imaging. To prepare these, two chalcones were attached α,ω onto oligoethylene glycol fragments, then reacted with nitromethane anion. Conjugate addition products from this reaction were then subjected to typical conditions for synthesis of aza-BODIPY dyes (NH4OAc, nBuOH, 120 °C); formation of boracycles in this reaction was concomitant with creation of macrocycles containing the oligoethylene glycol fragments. Similar dyes with acyclic oligoelythene glycol substituents in the same position were used to compare the efficiencies of the intra- and inter-molecular aza-BODIPY forming reactions, and the characteristics of the products. All the fluors with oligoethylene glycol fragments, ie cyclic or acyclic, localized in the endoplasmic reticulum of a fibroblast cell line (WEHI-13VAR), the human pancreatic cancer cell line (PANC-1, rough ER predominates) and human liver cancer cell line (HepG2, smooth ER prevalent). These fluors are potentially useful for near IR (λmax emis at 730 nm) ER staining probes. PMID:26138325

  2. Transport properties of carbon dioxide and ammonia in water - ethylene glycol mixtures from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Iskrenova, Eugeniya; Patnaik, Soumya S.

    2015-03-01

    The endothermic decomposition of ammonium carbamate has been proposed as a novel heat sink mechanism for aircraft thermal management (Johnson et al. SAE Technical Paper 2012-01-2190, 2012, doi:10.4271/2012-01-2190]). The products of this decomposition are carbon dioxide and ammonia which need to be efficiently removed in order to better control the decomposition reaction. Molecular dynamics simulations can provide insight into the transport properties of carbon dioxide and ammonia in the carrier fluid. In this work, an extensive set of molecular dynamics simulations was performed to better quantify the concentration dependence of solubility and diffusivity of carbon dioxide and ammonia in water, ethylene glycol, and their mixtures at standard temperature and pressure and at elevated temperature. The simulation results confirm the experimental observations that ammonia is more soluble than carbon dioxide in either water or ethylene glycol and that both carbon dioxide and ammonia are more soluble in ethylene glycol than in water. The simulations of water - ethylene glycol mixtures show that increasing the molar fraction of ethylene glycol leads to increased solubility of carbon dioxide and ammonia in the mixture. The authors gratefully acknowledge the DoD High Performance Computing Centers for computational resources.

  3. Advantages of using glycolic acid as a retardant in a brushite forming cement.

    PubMed

    Mariño, Faleh Tamimi; Torres, Jesús; Hamdan, Mohammad; Rodríguez, Carmen Rueda; Cabarcos, Enrique López

    2007-11-01

    In this study we have compared the effect of using acetic, glycolic, and citric acids on the brushite cement setting reaction and the properties of the resultant cement. The cement solid phase was made by mixing beta-tricalcium phosphate (beta-TCP), monocalcium dihydrogen phosphate anhydrate (MCPA), and sodium pyrophosphate, whereas the cement liquid phase consisted of aqueous solutions of carboxy acids at concentrations ranging from 0.5 to 3.5M. Cements were prepared by mixing the solid phase with the liquid phase to form a workable paste. The cement setting time was longer for glycolic and citric acids. The best mechanical properties in dry environments were obtained using glycolic and citric acid liquid phases. In a wet environment at 37 degrees C, the cement set with glycolic acid was the strongest one. Brushite cement diametral tensile strength seems to be affected by the calcium-carboxyl phase produced in the setting reaction. The acceptable setting time and mechanical properties of cements set in glycolic acid solutions are attributed to the additional hydrophilic groups in the carboxylic acid and the low solubility in water of the calcium salt produced in the reaction. Moreover, at high concentrations, carboxylic acids add chemically to the cement matrix becoming reactants themselves.

  4. Viscoelasticity of repaired sciatic nerve by poly(lactic-co-glycolic acid) tubes.

    PubMed

    Piao, Chengdong; Li, Peng; Liu, Guangyao; Yang, Kun

    2013-11-25

    Medical-grade synthetic poly(lactic-co-glycolic acid) polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly(lactic-co-glycolic acid) tubes. Ten sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly(lactic-co-glycolic acid) tubes. Stress relaxation and creep testing showed that at 7 200 seconds, the sciatic nerve anastomosed by poly(lactic-co-glycolic acid) tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly(lactic-co-glycolic acid) exhibits good viscoelasticity to meet the biomechanical require-ments for a biomaterial used to repair sciatic nerve injury.

  5. Poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) thermogel as a novel submucosal cushion for endoscopic submucosal dissection.

    PubMed

    Yu, Lin; Xu, Wei; Shen, Wenjia; Cao, Luping; Liu, Yan; Li, Zhaoshen; Ding, Jiandong

    2014-03-01

    Endoscopic submucosal dissection (ESD) is a clinical therapy for early stage neoplastic lesions in the gastrointestinal tract. It is, however, faced with a crucial problem: the high occurrence of perforation. The formation of a submucosal fluid cushion (SFC) via a fluid injection is the best way to avoid perforation, and thus an appropriate biomaterial is vital for this minimally invasive endoscopic technique. In this study, we introduced an injectable thermogel as a novel submucosal injection substance in ESD. The hydrogel synthesized by us was composed of poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymers. The polymer/water system was a low-viscosity fluid at room temperature and thus easily injected, and turned into a non-flowing gel at body temperature after injection. The submucosal injection of the thermogel to create SFCs was performed in both resected porcine stomachs and living minipigs. High mucosal elevation with a clear margin was maintained for a long duration. Accurate en bloc resection was achieved with the assistance of the thermogel. The mean procedure time was strikingly reduced. Meanwhile, no obvious bleeding, perforation and tissue damage were observed. The application of the thermogel not only facilitated the ESD procedure, but also increased the efficacy and safety of ESD. Therefore, the PLGA-PEG-PLGA thermogel provides an excellent submucosal injection system, and has great potential to improve the ESD technique significantly.

  6. Reduction of friction stress of ethylene glycol by attached hydrogen ions

    PubMed Central

    Li, Jinjin; Zhang, Chenhui; Deng, Mingming; Luo, Jianbin

    2014-01-01

    In the present work, it is shown that the friction stress of ethylene glycol can decrease by an order of magnitude to achieve superlubricity if there are hydrogen ions attached on the friction surfaces. An ultra-low friction coefficient (μ = 0.004) of ethylene glycol between Si3N4 and SiO2 can be obtained with the effect of hydrogen ions. Experimental result indicates that the hydrogen ions adsorbed on the friction surfaces forming a hydration layer and the ethylene glycol in the contact region forming an elastohydrodynamic film are the two indispensable factors for the reduction of friction stress. The mechanism of superlubricity is attributed to the extremely low shear strength of formation of elastohydrodynamic film on the hydration layer. This finding may introduce a new approach to reduce friction coefficient of liquid by attaching hydrogen ions on friction surfaces. PMID:25428584

  7. Effect of monopropylene glycol and gamma irradiation on Yarrowia lipolytica lipase stabilization.

    PubMed

    Alloue, W A M; Destain, J; Ongena, M; Blecker, C; Thonart, P

    2008-01-01

    This work investigated the effects of monopropylene glycol, protease inhibitor, and gamma irradiation on Yarrowia lipolytica lipase stability during storage. Enzyme liquid stabilization was achieved by addition of monopropylene glycol (MPG) at respective concentrations of 50, 75, and 90%, the protease inhibitors (P2714 and P8215) at 0.1%, and the gamma irradiation with 10kGy, 15kGy, and 25kGy doses. The results showed that monopropylene glycol limited the microorganism growth and decreased the enzymatic activity at high concentration (up to 50%), at two temperatures (20 and 4 degrees C). Enzyme stored at 20 degrees C lost its activity by 80% after two months. This loss was attributed to the protease's effect. At this temperature, the protease's activities have been limited by the specific inhibitors. The gamma irradiations improve microbial safety of liquid enzyme. PMID:18569869

  8. Treatment of pseudofolliculitis barbae with topical glycolic acid: a report of two studies.

    PubMed

    Perricone, N V

    1993-10-01

    Pseudofolliculitis barbae (razor bumps) is a foreign-body inflammatory reaction surrounding ingrown facial hair, which results from shaving. The problem occurs in persons with curly hair, with an incidence of over 50 percent in black men. The objective of the two studies described was to assess the effectiveness of topical glycolic acid in the treatment and prevention of razor bumps. The studies consisted of two placebo-controlled trials in thirty-five adult men. The results showed that glycolic acid lotion was significantly more effective than placebo in treating pseudofolliculitis barbae. There was over a 60 percent reduction in lesions on the treated side, which allowed daily shaving with little irritation. Topical application of glycolic acid lotion is an effective therapy for pseudofolliculitis barbae and allows the patient to resume a daily shaving regimen.

  9. Highly conductive polymer electrolyte membranes modified with polyethylene glycol-bis-carbamate

    NASA Astrophysics Data System (ADS)

    Fu, Guopeng; Dempsey, Janel; Kyu, Thein

    By virtue of its non-flammability and chemical stability, polyethylene glycol (PEG) networks have shown potential application in all solid-state polymer electrolyte membranes (PEM). However, room temperature ionic conductivity of these PEG based PEMs is inherently low. Plasticization of these PEMs is needed to improve the ionic conductivity. It was demonstrated by this group that small-molecule plasticizers such as succinonitrile, ethylene carbonate, or urea-carbamate can boost ionic conductivity of solid-state polymer electrolyte membranes. Polyethylene glycol bis-carbamate (PEGBC) was synthesized via condensation reaction of polyethylene glycol diamine and ethylene carbonate. The PEGBC modified PEM has shown higher ionic conductivity relative to the unmodified PEM. Moreover, PEGBC modified PEM has a better thermal stability relative to ethylene carbonate based liquid electrolyte with enhanced ionic conductivity. Supported by NSF-DMR 1161070, 1502543 and REU 1359321.

  10. DISINFECTION OF CLOUDS OF MENINGOPNEUMONITIS AND PSITTACOSIS VIRUSES WITH TRIETHYLENE GLYCOL VAPOR.

    PubMed

    Rosebury, T; Meiklejohn, G; Kingsland, L C; Boldt, M H

    1947-01-01

    1. Triethylene glycol in excess of saturation, introduced as a vapor into a cloud chamber in which a dynamic cloud of either meningopneumonitis virus or psittacosis virus was developed simultaneously with, or in most instances subsequently to, the glycol cloud, induced distinct reduction in concentration of air-home virus, as measured both by cloud sampling in capillary impingers and by exposure of mice to the cloud. The relative humidity in the chamber was held between 35 and about 60 per cent. 2. Reduction of virus concentration in samplers, in glycol runs as compared with controls, ranged from 0 to 93 per cent (average, 62 per cent). 3. Reduction of infective response in mice, based on counts of focal lesions on lung surfaces, ranged from 55 to 98 per cent (average 73 per cent).

  11. Thermosensitivity of bile acid-based oligo(ethylene glycol) stars in aqueous solutions.

    PubMed

    Strandman, Satu; Le Dévédec, Frantz; Zhu, X X

    2011-08-01

    Amphiphilic star-shaped oligo(ethylene glycol)s with a hydrophobic bile acid core and varying number of hydrophilic arms have been made. Their thermal behavior in aqueous solutions depends on the number rather than the length of the arms. The two-armed lithocholate derivative showed the strongest tendency for association and exhibited the lowest cloud point (79 °C) of the oligomers made, as well as another phase separation at a lower temperature (31 °C). The "double thermosensitivity" arising both from the salt-dependent LCST of the oligo(ethylene glycol) segments and the temperature-responsive self-assembly of amphiphilic bile acid derivative provides an interesting path in the design of bile acid-based smart materials.

  12. Thermosensitivity of bile acid-based oligo(ethylene glycol) stars in aqueous solutions.

    PubMed

    Strandman, Satu; Le Dévédec, Frantz; Zhu, X X

    2011-08-01

    Amphiphilic star-shaped oligo(ethylene glycol)s with a hydrophobic bile acid core and varying number of hydrophilic arms have been made. Their thermal behavior in aqueous solutions depends on the number rather than the length of the arms. The two-armed lithocholate derivative showed the strongest tendency for association and exhibited the lowest cloud point (79 °C) of the oligomers made, as well as another phase separation at a lower temperature (31 °C). The "double thermosensitivity" arising both from the salt-dependent LCST of the oligo(ethylene glycol) segments and the temperature-responsive self-assembly of amphiphilic bile acid derivative provides an interesting path in the design of bile acid-based smart materials. PMID:21661073

  13. Preparation and Thermo-Physical Properties of Fe2O3-Propylene Glycol Nanofluids.

    PubMed

    Shylaja, A; Manikandan, S; Suganthi, K S; Rajan, K S

    2015-02-01

    Iron oxide (Fe2O3) nanoparticles were prepared from ferric chloride and ferrous sulphate by precipitation reaction. Fe2O3-propylene glycol nanofluid was prepared by dispersing Fe2O3 nanoparticles in propylene glycol through stirred bead milling, shear homogenization and probe ultrasonication. The nanofluid was characterized through measurement of viscosity, particle size distribution and thermal conductivity. The interactions between Fe2O3 nanoparticles and propylene glycol on the nanoparticle surfaces lead to reduction in viscosity, the magnitude of which increases with nanoparticle concentration (0-2 vol%) at room temperature. The thermal conductivity enhancement for 2 vol% nanofluid was about 21% at room temperature, with liquid layering being the major contributor for thermal conductivity enhancement. PMID:26353708

  14. The effects of an alpha hydroxy acid (glycolic acid) on hairless guinea pig skin permeability.

    PubMed

    Hood, H L; Kraeling, M E; Robl, M G; Bronaugh, R L

    1999-11-01

    The barrier integrity of hairless guinea pig skin after treatment with an alpha hydroxy acid was assessed through in vivo topical application of an oil-in-water emulsion containing 5 or 10% glycolic acid at pH 3.0. The control was a commercial moisturizing lotion, pH 7.8. A dosing regimen for the glycolic acid formulations that was tolerated by the hairless guinea pigs and significantly decreased stratum corneum turnover time was determined using the dansyl chloride staining technique. Once-daily dosing of hairless guinea pig skin for 3 weeks with the glycolic acid formulations resulted in approximately a 36-39% decrease in stratum corneum turnover time compared with the control lotion. After this treatment, hairless guinea pigs were sacrificed for the in vitro measurement of the percutaneous absorption of [14C]hydroquinone and [14C]musk xylol. No significant differences in the 24-hour absorption of either test compound were found for skin treated with the control lotion or the glycolic acid formulations. There were also no significant differences found in the absorption of [3H]water through skin from the different treatment groups. Although no increase in skin penetration occurred after treatment with the glycolic acid formulations, histology revealed approximately a twofold increase in epidermal thickness. Also the number of nucleated cell layers nearly doubled in skin treated with 5% and 10% glycolic acid compared with the control lotion and untreated skin. These studies demonstrate that substantial changes in the structure of hairless guinea pig epidermis can occur without significant effect on skin permeability of two model compounds.

  15. The significance of water quality guidelines in environmental decision making: Ethylene glycol -- A case example

    SciTech Connect

    Craig, G.R.; Gilron, G.L.; Bishop, J.; Cerf, J.; Williams, J.

    1995-12-31

    Ethylene glycol is a principal component of deicing and anti-icing products commonly applied to aircraft in winter prior to take-off. Many airports do not have efficient collection systems in place surrounding aquatic environments and biota are often exposed to ethylene glycol contained in direct runoff and snowmelt. This study was designed to fulfill the minimum ecotoxicity data requirements for the development of a water quality guideline for ethylene glycol. Ecotoxicity testing was conducted using reagent-grade ethylene glycol and exposure concentrations were confirmed by GC/FID direct aqueous injection, or based on spectrophotometric measurement of the purpene-glycol reaction. The highest ethylene glycol NOEC values for the organisms tested included rainbow trout fry growth 14,692 mg/L, fathead minnow fry growth 12,531 mg/l, Ceriodaphnia dubia reproduction 3,469 mg/L, the ciliate Colpidium campylum 28,090 mg/L, and the rotifer Brachionus calyciflorus 12,800 mg/L. The highest non-lethal level for rainbow trout and the for the frog Xenopus laevis was 12,500 mg/L. Results indicated that the 48-hr LC50 for Xenopus laevis reported in an earlier study (and which was used in the derivation of some interim guidelines) could not be reproduced. However, results of the fish and invertebrate tests compared favorably with other literature values for similar species and with QSAR estimates. A number of water quality derivation protocols (CCME, Ontario MOE, and US EPA) were applied to the data set for the comparison of generated guideline values. Differences in values demonstrate the economic need for using a common approach in developing guidelines that are used to assess hazard to similar ecosystems in different jurisdictions within a global marketplace.

  16. Aphids preserved in propylene glycol can be used for reverse transcription-polymerase chain reaction detection of Potato virus Y.

    PubMed

    Nie, Xianzhou; Pelletier, Yvan; Mason, Nicola; Dilworth, Andrea; Giguère, Marie-Andrée

    2011-08-01

    The effectiveness of propylene glycol on the retention of RNA target of Potato virus Y (PVY), an aphid stylet-borne virus, in Myzus persicae was investigated in comparison to ethanol and liquid nitrogen/-80°C. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the PVY targets from the propylene glycol/ethanol/liquid nitrogen preserved single aphids after a 5min acquisition period from infected potato plants. In the liquid nitrogen/-80°C and 70% ethanol treatments, 55.6% and 38.8% aphids tested PVY-positive, respectively. In the 0-75% propylene glycol treatments, 12.2-44.7% aphids tested PVY-positive. The lowest detection rate was in the 0% (positive rate, 15.2%) and the 10% propylene glycol (positive rate, 12.2%). As the propylene glycol concentration increased to 25%, 29.8% aphids tested positive. A high PVY-positive rate was also found in 35-75% propylene glycol treatments at 44.7% (35% propylene glycol), 36.7% (50% propylene glycol) and 34.8% (75% propylene glycol), which is comparable to the rate shown in 70% ethanol. No significant difference in the positive detection rate was observed in aphids preserved in 50% propylene glycol at room temperature for 2, 4 and 10 days. These results demonstrate that propylene glycol at 25-75% can retain PVY targets effectively in aphids for an extended time period, and thus can be used in aphid traps to preserve viruliferous aphids for later RT-PCR detection of PVY.

  17. Physical properties of poly(lactic-co-glycolic) and poly(ethylene glycol) nanoparticles for drug delivery using atomic force microscopy (AFM) and electrostatic nanolithography

    NASA Astrophysics Data System (ADS)

    Lyuksyutov, Sergei; Fedin, Igor; Nedashkivska, Victoria; Lyuksyutova, Caterina; Geldenhuys, Werner; Sutariya, Vijay

    2010-03-01

    Nanoparticles (NP) of biodegradable polymers poly(lactic-co-glycolic)(PLGA) and poly(ethylene glycol) (PEG) are potential drug delivery components for biomedical applications. The NP based on PLGA or PEG can be directed to accumulate in cancer tumor cells with the use of anti-bodies which are conjugated to the NP. The NP's size distribution is the critical property for biochemical affinity and therefore delivery to the specific target organs. We used an atomic force microscopy (AFM) to characterize the NP size and AFM electrostatic nanolithography (AFMEN) to study the behavior of PEG-PLGA NP under the extreme electric fields exceeding 10^9 V m-1. AFMEN allows the displacement of molecules along the lines of the electric field due to electrostatic polarization. This study has an important practical application for the optimum design of NP with the correct characteristics for drug delivery.

  18. Synthesis and application of ion-imprinted polymer nanoparticles for the extraction and preconcentration of copper ions in environmental water samples.

    PubMed

    Roushani, Mahmoud; Abbasi, Shahryar; Khani, Hossein

    2015-04-01

    Novel Cu(II) ion-imprinted polymers (Cu-IIP) nanoparticles were prepared by using Cu(II) ion-thiosemicarbazide complex as the template molecule and methacrylic acid, ethylene glycol dimethacrylate (EGDMA), and 2,2'azobisisobutyronitrile (AIBN) as the functional monomer, cross-linker, and the radical initiator, respectively. The synthesized polymer nanoparticles were characterized by using infrared spectroscopy (IR), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopic (SEM) techniques. Some parameters such as pH, weight of the polymer, adsorption time, elution time, eluent type, and eluent volume which affect the extraction efficiency of the polymer were studied. In the proposed method, the maximum sorbent capacity of the ion-imprinted polymer was calculated to be 38.8 mg g(-1). The preconcentration factor, relative standard deviation, and limit of detection of the method were found to be 80, 1.7%, and 0.003 μg mL(-1), respectively. The prepared ion-imprinted polymer nanoparticles have an increased selectivity toward Cu(II) ions over a range of competing metal ions with the same charge and similar ionic radius. The method was applied to the determination of ultra trace levels of Cu2+ in environmental water samples with satisfactory results.

  19. A novel solid-phase extraction-spectrofluorimetric method for the direct determination of atenolol in human urine.

    PubMed

    Basan, Hasan; Yarımkaya, Sezen

    2014-05-01

    A novel, simple, sensitive and selective solid-phase extraction (SPE)-spectrofluorimetric method has been developed for the determination of atenolol (ATE) in human urine. Because an extraction procedure is required to isolate ATE or eliminate the interfering molecules present in complex human urine for the direct spectrofluorimetric determination, a pH-sensitive poly(acrylic acid-ethylene glycol dimethacrylate) [poly(AA-EGDMA)] hydrogel was developed and used as a SPE adsorbent. Some factors affecting the ATE extraction efficiency, such as washing solvent type and volume, and the volume of elution solvent were optimized. Eluates from SPE cartridges were analyzed using a spectrofluorimeter (λ(ex)  = 277 nm and λ(em)  = 300 nm). The calibration graph was linear over the concentration range 0.15-4.0 µg/mL. Limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.03 and 0.10 µg/mL, respectively. Relatively high intraday [2.06%, mean relative standard deviation (RSD)] and interday (2.6%, mean RSD) precisions were achieved. High mean recovery (95.4%) and low RSD values (3.8%) were obtained for spiked ATE in human urine. The spectrofluorimetric method presented here can be easily applied to assay trace amounts of ATE in pharmaceuticals and biological samples.

  20. Molecularly imprinted polymer on a SiO2 -coated graphene oxide surface for the fast and selective dispersive solid-phase extraction of Carbamazepine from biological samples.

    PubMed

    Khalilian, Faezeh; Ahmadian, Setareh

    2016-04-01

    A surface carbamazepine-imprinted polymer was grafted and synthesized on the SiO2 /graphene oxide surface. Firstly SiO2 was coated on synthesized graphene oxide sheet using the sol-gel technique. Prior to polymerization, the vinyl group was incorporated on to the surface of SiO2 /graphene oxide to direct selective polymerization on the surface. Methacrylic acid, ethylene glycol dimethacrylate and ethanol were used as monomer, cross-linker and porogen, respectively. Nonimprinted polymer was also prepared for comparison. The properties of the molecularly imprinted polymer were characterized using field-emission scanning electron microscopy and Fourier-transform infrared spectroscopy. The surface molecularly imprinted polymer was utilized as an adsorbent of dispersive solid-phase extraction for separation and preconcentration of carbamazepine. The effects of the different parameters influencing the extraction efficiency, such as sample pH were investigated and optimized. The specificity of the molecular imprinted polymer over the nonimprinted polymer was examined in absence and presence of competitive drugs. The carbamazepine calibration curve showed linearity in the ranges 0.5-500 μg/L. The limits of detection and quantification under the optimized conditions were 0.1 and 0.3 μg/L, respectively. The within-day and between-day relative standard deviations (n = 3) were 3.6 and 4.3%, respectively. Furthermore, the relative recoveries for spiked biological samples were above 85%. PMID:26899307

  1. Synthesis and application of ion-imprinted polymer nanoparticles for the determination of nickel ions

    NASA Astrophysics Data System (ADS)

    Abbasi, Shahryar; Roushani, Mahmoud; Khani, Hossein; Sahraei, Reza; Mansouri, Ghobad

    2015-04-01

    Novel Ni(II) ion-imprinted polymers (Ni-IIP) nanoparticles were prepared by using Ni(II) ion-1,5-diphenyl carbazide (DPC) complex as the template molecule and methacrylic acid, ethylene glycol dimethacrylate (EGDMA) and 2,2‧-azobisisobutyronitrile (AIBN) as the functional monomer, cross-linker and the radical initiator, respectively. The synthesized polymer particles were characterized physically and morphologically by using infrared spectroscopy (IR), thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques. Some parameters such as pH, weight of the polymer, adsorption time, elution time, eluent type and eluent volume which affects the efficiency of the polymer were studied. The preconcentration factor, relative standard deviation, and limit of detection of the method were found to be 100, 1.9%, and 0.002 μg mL-1, respectively. The prepared ion-imprinted polymer particles have an increased selectivity toward Ni(II) ions over a range of competing metal ions with the same charge and similar ionic radius. The method was applied to the determination of nickel in tomato and some water samples.

  2. Polymeric Colloidal Nanostructures Fabricated via Highly Controlled Convective Assembly and Their Use for Molecular Imprinting.

    PubMed

    Yang, Jin Chul; Park, Jin Young

    2016-03-23

    In this work, the formation of various polystyrene (PS) colloidal structures on striped PS patterns is demonstrated based on a simple and novel convective assembly method that controls the electrostatic interactions between the PS colloidal particles and sodium dodecyl sulfate (SDS). Under the optimal conditions (different withdrawal speeds, channel dimensions, suspension concentrations, etc.), highly ordered structures such as highly close-packed, zigzag, and linear colloidal aggregates are observed. In addition, these colloidal arrangements are used for development of molecularly imprinted polymer (MIP) sensors with highly improved sensing properties. Using PDMS replicas, three hemispherical poly(methacrylic acid-ethylene glycol dimethacrylate) (poly(MAA-EGDMA)) MIP films, including planar MIP and non-imprinted polymer (NIP) films, are photopolymerized for detection of trace atrazine in an aqueous solution. From gravimetric quartz crystal microbalance (QCM) measurements, a non-close-packed MIP film exhibits highest sensing response (Δf = 932 Hz) to atrazine detection among hemispherical MIP films and shows 6.5-fold higher sensing response than the planar MIP film. In addition, the sensitivity of the MIP sensor is equivalent to -119 Hz/(mol L(-1)). From the ratio of slopes of the calibration curves for the hemispherical MIP and NIP films, the imprinting factor (If) is as high as 11.0. The hemispherical MIP film also shows excellent selectivity in comparison with the sensing responses of other analogous herbicides. As a result, this molecular surface imprinting using PS colloidal arrays is highly efficient for herbicide detection. PMID:26938141

  3. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  4. Synthesis, Characterization, and Size Control of Zinc Sulfide Nanoparticles Capped by Poly(ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Allehyani, S. H. A.; Seoudi, R.; Said, D. A.; Lashin, A. R.; Abouelsayed, A.

    2015-11-01

    Zinc sulfide nanoparticles with controllable size were synthesized by chemical precipitation. Results from transmission electron microscopy and x-ray powder diffraction showed the samples were grown with the cubic phase. Particle size was varied by varying the molar ratio of zinc chloride to sodium sulfide in the presence of poly(ethylene glycol). The optical band gap was calculated on the basis of ultraviolet-visible spectroscopy and ranged from 4.13 to 4.31 eV depending on particle size. Surface passivation and adsorption of poly (ethylene glycol) on the nanoparticles was explained on the basis of Fourier-transform infrared measurements.

  5. Gas-phase synthesis of morpholine from diethylene glycol and ammonia

    SciTech Connect

    Kronich, I.G.; Dobrovol'skii, S.V.; Nikolaev, Y.T.; Shikunov, B.I.; Dyumaev, K.M.

    1982-11-01

    The theory and practice of catalysis in the process of amination of compounds which contain two or more hydroxyl groups has generated much interest. Specifically, there is particular interest in the reaction of diethylene glycol and ammonia; the amination process in this case is accompanied by cyclization with formation of morpholine - a very important product which is needed in growing amounts in the production of rubber vulcanization accelerators, optical bleaches and a number of other products. The possibility of producing morpholine from diethylene glycol and ammonia in gas phase in the presence of hydrogenating-dehydrogenating catalysts was demonstrated earlier. This report presents the results of further research in this area.

  6. Ethylene glycol (antifreeze) poisoning in a free-ranging polar bear

    SciTech Connect

    Amstrup, S.C.; Gardner, C.; Myers, K.C.; Oehme, F.W. )

    1989-08-01

    The bright, fluorescent pink-colored remains of a polar bear were found on an Alaskan island with the gravel and snow adjacent to the bear colored bright purple. Traces of fox urine and feces found nearby were also pink. The pink and purple colors were due to rhodamine B, and ethylene glycol (EG) was present in the soil under the carcass. Evidence is given to suggest the bear consumed a mixture of rhodamine B and EG commonly used to mark roads and runways during snow and ice periods. Such wildlife losses could be prevented by substituting propylene glycol for the EG in such mixtures.

  7. Mineral induced phosphorylation of glycolate ion--a metaphor in chemical evolution

    NASA Technical Reports Server (NTRS)

    Kolb, V.; Zhang, S.; Xu, Y.; Arrhenius, G.

    1997-01-01

    Bilateral surface-active minerals with excess positive charge concentrate glycolate and trimetaphosphate ion from l0(-3) m aqueous solution to half-saturation of the internal surface sites, and induce phosphorylation of glycolate ion in the mineral with trimetaphosphate, sorbed from l0(-2) m solution. By utilizing reactants from dilute solution at near-neutral pH, and eliminating the need for participating organic nitrogen compounds, the reaction comprises several elements considered necessary for geochemical realism in models for molecular evolution.

  8. Preparation of erythrocyte ghosts by a glycol-induced osmotic lysis under isoionic conditions.

    PubMed

    Billah, M M; Finean, J B; Coleman, R; Michell, R H

    1976-04-16

    A procedure has been developed for obtaining haemoglobin-free, erythrocyte ghosts under ionic conditions approximating that of the cell cytoplasm. Haemolysis was effected by incorporating glycol into cells suspended in the isoionic medium and then diluting with a large volume of glycol-free medium. The ghosts were of uniform spherical shape throughout the preparative procedure and were impermeable to macromolecules. Analysis of polypeptides by sodium dodecyl sulphate-gel electrophoresis at each stage of preparation and comparison with ghosts prepared under hypo-ionic conditions served to distinguish membrane components from those of cytoplasm.

  9. Supramolecular interactions between beta-cyclodextrin and hydrophobically end-capped poly(ethylene glycol)s: a quartz crystal microbalance study.

    PubMed

    Kham, Khémara; Guerrouache, Mohamed; Carbonnier, Benjamin; Lazerges, Mathieu; Perrot, Hubert; Millot, Marie-Claude

    2007-11-15

    In this study, the supramolecular interactions occurring between beta-cyclodextrin-based surfaces and macromolecular chains modified at one end with naphthyl, adamantyl, or phenyladamantyl hydrophobic groups were investigated by means of a quartz crystal microbalance. beta-Cyclodextrin-functionalized gold electrodes were obtained through the amide-coupling reaction between mono-6-deoxy-6-amino-beta-cyclodextrin and 11-mercaptoundecanoic acid self-assembled monolayer allowing the reproducible preparation of densely grafted surfaces with host properties. The interaction data obtained for the three different modified poly(ethylene glycol)s are in good agreement with our previous studies performed by high performance liquid chromatography and surface plasmon resonance. This evidences that the driving force for the supramolecular interaction is based on the inclusion of the hydrophobic terminal group of the chains within the cyclodextrin cavities. The reversibility of the inclusion process was proven through the regeneration of the original host properties of the sensing surfaces using sodium dodecylsulfate as a competitor for the desorption of the poly(ethylene glycol) chains.

  10. Highly efficient conversion of biomass-derived glycolide to ethylene glycol over CuO in water.

    PubMed

    Xu, Lingli; Huo, Zhibao; Fu, Jun; Jin, Fangming

    2014-06-01

    The efficient conversion of biomass-derived glycolide into ethylene glycol over CuO in water was investigated. The reaction of glycolide was carried out with 25 mmol Zn and 6 mmol CuO with 25% water filling at 250 °C for 150 min, which yielded the desired ethylene glycol in 94% yield. PMID:24769741

  11. Determination of trace amounts of ethylene glycol and its analogs in water matrixes by liquid chromatography/tandem mass spectrometry.

    PubMed

    Tran, Buu N; Okoniewski, Richard; Bucciferro, Anthony; Jansing, Robert; Aldous, Kenneth M

    2014-01-01

    Contamination of drinking water by ethylene glycol (EG) is a public health concern. EG causes adverse health effects in humans and animals, including cardiopulmonary and acute renal failure. EG and other glycols, such as propylene glycol (PG) are major components in antifreeze liquids, which may be the main source of contamination of ground water. A sensitive LC/electrospray ionization (ESI)-MS/MS method was developed to measure trace amounts of EG, diethylene glycol, and 1,2- and 1,3-PG in several water sources, including municipal tap, lake, river, and salinated water. In this method, glycols in water samples were derivatized with benzoyl chloride by the Schotten-Baumann reaction, followed by liquid-liquid extraction using pentane as the organic solvent prior to the LC/ESI-MS/MS determination. QC included analysis of a method blank and samples fortified at low and high levels. Analytical data showed excellent linear calibration for all observed glycols, with good precision and accuracy. The method detection limits for the studied glycols ranged from 1.9 to 6.1 ng/mL across the water matrixes tested. This method is suitable to help assess water quality in areas that may be prone to glycol contamination.

  12. Synthesis of glycolate from pyruvate via isocitrate lyase by tobacco leaves in light. [Nicotiana tabacum var Havana Seed

    SciTech Connect

    Zelitch, I. )

    1988-02-01

    Tobacco (Nicotiana tabacum var Havana Seed) leaf discs were supplied tracer quantities of (2-{sup 14}C)- and (3-{sup 14}C) pyruvate for 60 minutes in steady state photosynthesis with 21% or 1% O{sub 2}, and the glycolate oxidase inhibitor {alpha}-hydroxy-2-pyridinemethanesulfonic acid was then added for 5 or 10 minutes to cause glycolate to accumulate. The (3-{sup 14}C) pyruvate was converted directly to glycolate as shown by a 50% greater than equal-labeled {sup 14}C in C-2 of glycolate, and the fraction of {sup 14}C in C-2 increased in 1% O{sub 2} to 80% greater than equal-labeled. This suggests the pathway using pyruvate is less O{sub 2}-dependent than the oxygenase reaction producing glycolate from the Calvin cycle. The formation of glycolate from pyruvate in the leaf discs was time-dependent and with (2-{sup 14}C)- and (3-{sup 14}C) pyruvate supplied leaf discs the C-2 of glyoxylate derived from C-2 of isocitrate was labeled asymmetrically in a manner similar to the asymmetrical labeling of C-2 of glycolate under a number of conditions. Thus glycolate was probably formed by the reduction of glyoxylate. Isocitric lyase activity of tobacco leaves was associated with leaf mitochondria, through most of the activity was in the supernatant fraction after differential centrifugation of leaf homogenates.

  13. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ether from the list of hazardous air pollutants. 63.63 Section 63.63 Protection of Environment... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  14. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Dimer acids, polymer with polyalkylene... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  15. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dimer acids, polymer with polyalkylene... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  16. Human Oocyte Vitrification: The permeability of metaphase II oocytes to water and ethylene glycol and the appliance toward vitrification

    PubMed Central

    Mullen, Steven F.; Li, Mei; Li, Yuan; Chen, Zi-Jiang; Critser, John K.

    2008-01-01

    Objectives To determine the permeability of human metaphase II oocytes to ethylene glycol and water in the presence of ethylene glycol, and to use this information to develop a method to vitrify human oocytes. Design An incomplete randomized block design was used for this study. Setting A University-affiliated assisted reproductive center. Patients Women undergoing assisted reproduction in the Center for Reproductive Medicine at Shandong University. Interventions Oocytes were exposed to 1.0 molar ethylene glycol in a single step, and photographed during subsequent volume excursions. Main outcome measures A 2-parameter model was employed to estimate the permeability to water and EG. Results Water permeability ranged from 0.15 to 1.17 µm/(min·atm), and ethylene glycol permeability ranged from 1.5 to 30 µm/min between 7 °C at 36 °C. The activation energies for water and ethylene glycol permeability were 14.42 Kcal/mol and 21.20 Kcal/mol, respectively. Conclusions Despite the lower permeability of human MII oocytes to ethylene glycol compared to previously published values for propylene glycol and dimethylsulfoxide, methods to add and remove human oocytes with a vitrifiable concentration of ethylene glycol can be designed which prevent excessive osmotic stress and minimize exposure to high concentrations of this compound. PMID:17681308

  17. Glycolic acid chemical peeling improves inflammatory acne eruptions through its inhibitory and bactericidal effects on Propionibacterium acnes.

    PubMed

    Takenaka, Yuko; Hayashi, Nobukazu; Takeda, Mikiko; Ashikaga, Sayaka; Kawashima, Makoto

    2012-04-01

    Glycolic acid chemical peeling is effective for treating comedones, and some clinical data show that it also improves inflammatory eruptions. The purpose of this study was to identify the mechanism of glycolic acid chemical peeling to improve inflammatory acne. To assess growth inhibitory and bactericidal effects of glycolic acid on Propionibacterium acnes in vitro, we used an agar diffusion method and a time-kill method. To reveal bactericidal effects in vivo, we established an agar-attached method which correlated well with the ordinary swab-wash method, and we used the agar-attached method to compare the numbers of propionibacteria on the cheek treated with glycolic acid chemical peeling. Our results show that 30% glycolic acid (at pH 1.5, 3.5 and 5.5) formed growth inhibitory circles in the agar diffusion method, but the diameters of those circles were smaller than with 1% nadifloxacin lotion or 1% clindamycin gel. In the time-kill method, 30% glycolic acid (at pH 1.5 and 3.5) or 1% nadifloxacin lotion reduced the number of P. acnes to less than 100 CFU/mL within 5 min. In contrast, in 30% glycolic acid (at pH 5.5) or in 1% clindamycin gel, P. acnes survived for more than 4 h. Chemical peeling with 35% glycolic acid (at pH 1.2) decreased the number of propionibacteria on the cheeks of patients compared with untreated controls (P < 0.01). Our results demonstrate that glycolic acid has moderate growth inhibitory and bactericidal effects on P. acnes, and that chemical peeling with glycolic acid works on inflammatory acne via those effects. PMID:21950544

  18. Glycolic acid chemical peeling improves inflammatory acne eruptions through its inhibitory and bactericidal effects on Propionibacterium acnes.

    PubMed

    Takenaka, Yuko; Hayashi, Nobukazu; Takeda, Mikiko; Ashikaga, Sayaka; Kawashima, Makoto

    2012-04-01

    Glycolic acid chemical peeling is effective for treating comedones, and some clinical data show that it also improves inflammatory eruptions. The purpose of this study was to identify the mechanism of glycolic acid chemical peeling to improve inflammatory acne. To assess growth inhibitory and bactericidal effects of glycolic acid on Propionibacterium acnes in vitro, we used an agar diffusion method and a time-kill method. To reveal bactericidal effects in vivo, we established an agar-attached method which correlated well with the ordinary swab-wash method, and we used the agar-attached method to compare the numbers of propionibacteria on the cheek treated with glycolic acid chemical peeling. Our results show that 30% glycolic acid (at pH 1.5, 3.5 and 5.5) formed growth inhibitory circles in the agar diffusion method, but the diameters of those circles were smaller than with 1% nadifloxacin lotion or 1% clindamycin gel. In the time-kill method, 30% glycolic acid (at pH 1.5 and 3.5) or 1% nadifloxacin lotion reduced the number of P. acnes to less than 100 CFU/mL within 5 min. In contrast, in 30% glycolic acid (at pH 5.5) or in 1% clindamycin gel, P. acnes survived for more than 4 h. Chemical peeling with 35% glycolic acid (at pH 1.2) decreased the number of propionibacteria on the cheeks of patients compared with untreated controls (P < 0.01). Our results demonstrate that glycolic acid has moderate growth inhibitory and bactericidal effects on P. acnes, and that chemical peeling with glycolic acid works on inflammatory acne via those effects.

  19. 40 CFR 63.62 - Redefinition of glycol ethers listed as hazardous air pollutants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Redefinition of glycol ethers listed as hazardous air pollutants. 63.62 Section 63.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  20. 40 CFR 63.62 - Redefinition of glycol ethers listed as hazardous air pollutants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Redefinition of glycol ethers listed as hazardous air pollutants. 63.62 Section 63.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  1. Severe propylene glycol toxicity secondary to use of anti-epileptics.

    PubMed

    Pillai, Unnikrishnan; Hothi, Jatinder C; Bhat, Zeenat Y

    2014-01-01

    Propylene glycol toxicity presenting as high anion gap metabolic acidosis and osmolar gap has been extensively reported in literature, and most of them are secondary to intravenous lorazepam infusion. However, propylene glycol is used as a solvent in a number of medications that are frequently utilized in critical care setting, and hence one should be aware that the toxicity is possible from a variety of medication. Phenobarbital and phenytoin are one of those, and we hereby report a novel case of propylene glycol toxicity secondary to phenobarbital and phenytoin infusion in a patient with refractory status epilepticus. Furthermore, our patient had end-stage renal disease, which we think could have been an important precipitating factor for the toxicity. Because most of the symptoms from propylene glycol toxicity can mimic sepsis-which is very common in critical care unit patients-this life threatening scenario could be easily missed. Regular monitoring of osmolar gap is an easily available intervention in the at risk patients.

  2. 40 CFR 721.10610 - Toluene diisocyanate, polymers with polyalkylene glycol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Toluene diisocyanate, polymers with... New Uses for Specific Chemical Substances § 721.10610 Toluene diisocyanate, polymers with polyalkylene... substances identified generically as toluene diisocyanate, polymers with polyalkylene glycol (PMNs...

  3. 40 CFR 721.10610 - Toluene diisocyanate, polymers with polyalkylene glycol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Toluene diisocyanate, polymers with... New Uses for Specific Chemical Substances § 721.10610 Toluene diisocyanate, polymers with polyalkylene... substances identified generically as toluene diisocyanate, polymers with polyalkylene glycol (PMNs...

  4. Film-forming properties of blends of high-oleic sunflower oil with polyalkyl glycol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The viscosity, density, and elastohydrodynamic film thicknesses of oil-soluble polyalkyl glycols (PAG), high oleic sunflower oil (HOSuO), and their 50/50 (wt.) blends were investigated. The viscosity and density of the blends were found to be predictable from the corresponding neat oil properties us...

  5. 40 CFR 721.10661 - Methylenebis [isocyanatobenzene], polymer with alkanedoic acid, alkylene glycols, alkoxylated...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Methylenebis , polymer with alkanedoic acid, alkylene glycols, alkoxylated alkanepolyol and substituted trialkoxysilane (generic). 721.10661 Section 721.10661 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES...

  6. Production of 2,3-butylene glycol from citrus wastes. II. The Bacillus polymyxa fermentation.

    PubMed

    Long, S K; Patrick, R

    1965-11-01

    The conditions required for production of levo 2,3-butylene glycol by Bacillus polymyxa from citrus molasses were studied. Starter cultures required acclimatization to the substrate prior to inoculation of the fermentation medium. Maximal production of butylene glycol with minimal residual sugar was obtained with a medium consisting of molasses, diluted to 20 degrees Brix, and 0.4% urea. Optimal environmental conditions included aeration at 0.11 volumes of air per volume of medium per minute, maintenance of pH at 6.0 to 6.2, a fermentation temperature of 30 C, and a stirring rate of 420 rev/min. The concentration of butylene glycol obtained in the fermentation beer ranged from 2.3 to 4.4%. The optical rotation of the glycol ranged from [alpha](D) (23 degrees ) = -1.01 degrees to -10.45 degrees . The variation in rotation was probably due to the presence of contaminating substances in the distillate. PMID:5866043

  7. Detection of ethylene glycol - toward W51/e2 and G34.3+0.02

    NASA Astrophysics Data System (ADS)

    Lykke, Julie M.; Favre, Cécile

    2014-07-01

    Ethylene glycol (HOCH2CH2OH), also commenly known as antifreeze, is the reduced alcohol version of glycolaldehyde (CH2OHCHO). Glycoladehyde - the simplest possible aldehyde sugar (Marstokk and Møllendal 1973) - is the first intermediate step in the path toward forming more complex and biologically relevant molecules through the the formose reaction, which begins with formaldehyde (H2CO) and ends with the formation of sugars and ultimately ribose, the backbone of RNA (e.g., Larralde et al. 1995). The presence of glycolaldehyde is therefore an important indication that processes leading to biologically relevant molecules are taking place. It is however, still unclear as to how glycolaldehyde and ethylene glycol are formed in the ISM. It has been proposed that they share a common formation pathway through UV-irradiation of methanol (CH3OH) ices mixed with CO (Öberg et al. 2009). So far, ethylene glycol, in its lower energy con-former (g’Ga(CH2OH)2), has been detected toward SgrB2 (N) by Hollis et al. (2002), tentatively toward IRAS 16293-2422 (Jørgensen et al. 2012) and marginally by Kalenskii and Johansson (2010) toward W51 e1/e2. Here we present a firm detection of ethylene glycol toward W51/e2 as well as a first detection toward G34.3+0.02 at 1mm and 3mm using the IRAM 30m telescope.

  8. Relative toxicities of pure propylene and ethylene glycol and formulated deicers on plant species

    SciTech Connect

    DuFresne, D.L.; Pillard, D.A.

    1994-12-31

    Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum), and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot length, survival, and growth. Formulated deicers, like those used at airports, were generally more toxic than pure chemicals, based on glycol concentration. This greater toxicity of formulated deicers is consistent with results of tests using animal species.

  9. BULK SYNTHESIS OF SILVER NANORODS IN POLY(ETHYLENE GLYCOL) USING MICROWAVE IRRADIATION

    EPA Science Inventory

    Microwave-assisted (MW), surfactantless, greener approach to bulk synthesis of silver nanorods employing poly (ethylene glycol) (PEG) is described. An aqueous solution of silver nitrate (AgNO-3,- 0.1 M, 4 mL) and 4 mL of PEG (molecular weight 300) were mixed at room temperature t...

  10. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... percent total by weight of ethylene and diethylene glycols when tested by the analytical methods prescribed in paragraph (b) of this section. (b) Analytical method. (1) The analytical method prescribed in... of 450 or higher. (2) The following analytical method shall be used to determine the total...

  11. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... percent total by weight of ethylene and diethylene glycols when tested by the analytical methods prescribed in paragraph (b) of this section. (b) Analytical method. (1) The analytical method prescribed in... of 450 or higher. (2) The following analytical method shall be used to determine the total...

  12. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol...

  13. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol...

  14. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol...

  15. Pervaporation process and use in treating waste stream from glycol dehydrator

    DOEpatents

    Kaschemekat, Jurgen; Baker, Richard W.

    1994-01-01

    Pervaporation processes and apparatus with few moving parts. Ideally, only one pump is used to provide essentially all of the motive power and driving force needed. The process is particularly useful for handling small streams with flow rates less than about 700 gpd. Specifically, the process can be used to treat waste streams from glycol dehydrator regeneration units.

  16. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol...

  17. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  18. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  19. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  20. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  1. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  2. 40 CFR 63.62 - Redefinition of glycol ethers listed as hazardous air pollutants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Redefinition of glycol ethers listed as hazardous air pollutants. 63.62 Section 63.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  3. The Effect of Ethylene Glycol, Glycine Betaine, and Urea on Lysozyme Thermal Stability

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Leslie, Elizabeth J.; Nordstrom, Anna R.

    2010-01-01

    The four-week student project described in this article is an extension of protein thermal denaturation experiments to include effects of added cosolutes ethylene glycol, glycine betaine, and urea on the unfolding of lysozyme. The transition temperatures and van't Hoff enthalpies for unfolding are evaluated for six concentrations of each cosolute,…

  4. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  7. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  8. 40 CFR 721.10515 - Partially fluorinated alcohol substituted glycols (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Partially fluorinated alcohol... New Uses for Specific Chemical Substances § 721.10515 Partially fluorinated alcohol substituted... substances identified generically as partially fluorinated alcohol substituted glycols (PMN P-10-58,...

  9. Insights on cryoprotectant toxicity from gene expression profiling of endothelial cells exposed to ethylene glycol.

    PubMed

    Cordeiro, Rui Martins; Stirling, Soren; Fahy, Gregory M; de Magalhães, João Pedro

    2015-12-01

    Cryopreservation consists of preserving living cells or tissues generally at -80 °C or below and has many current applications in cell and tissue banking, and future potential for organ banking. Cryoprotective agents such as ethylene glycol (EG) are required for successful cryopreservation of most living systems, but have toxic side effects whose mechanisms remain largely unknown. In this work, we investigated the mechanisms of toxicity of ethylene glycol in human umbilical vein endothelial cells (HUVECs) as a model of the vascular endothelium in perfused organs. Exposing cells to 60% v/v EG for 2 h at 4 °C resulted in only a slight decrease in subsequent cell growth, suggesting only modest toxicity of EG for this cell type. Gene expression analysis with whole genome microarrays revealed signatures indicative of a generalized stress response at 24 h after EG exposure and a trend toward partial recovery at 72 h. The observed changes involved signalling pathways, glycoproteins, and genes involved in extracellular and transmembrane functions, the latter suggesting potential effects of ethylene glycol on membranes. These results continue to develop a new paradigm for understanding cryoprotectant toxicity and reveal molecular signatures helpful for future experiments in more completely elucidating the toxic effects of ethylene glycol in vascular endothelial cells and other cell types. PMID:26471925

  10. Excess wing in the dielectric loss spectra of propylene glycol oligomers at elevated pressure

    NASA Astrophysics Data System (ADS)

    Casalini, R.; Roland, C. M.

    2004-03-01

    Dielectric loss spectra at both ambient and elevated pressure are presented for propylene glycol (PG), dipropylene glycol, and tripropylene glycol. While in previous literature the excess wing (EW) was observed only for PG, we show herein that under high pressure an EW (coexistent with a secondary β relaxation) is present for all these materials. Furthermore, at higher pressures the EW evolves into a well-separated peak. The pressure sensitivity of the EW is very different from that of the β relaxation, being close to that of the structural relaxation, whereas the β peak is virtually insensitive to pressure. These differences imply a very different degree of intermolecularity of the underlying motions. A similarly small sensitivity to pressure has been observed for the β relaxation in sorbitol. We have measured the spectrum of sorbitol at high pressure, and likewise it indicates the presence of a submerged EW. Finally, the behavior observed for the EW in the glycols is shown to be consistent with predictions of the coupling model, relating the most probably relaxation time for the secondary process to a noncooperative relaxation time. This suggests that the EW may be the precursor to the α relaxation and therefore of fundamental importance to understanding the vitrification process in supercooled liquids and polymers.

  11. Design, Synthesis and Hydrolytic Behavior of Mutual Prodrugs of NSAIDs with Gabapentin Using Glycol Spacers

    PubMed Central

    Mahdi, Monther Faisal; Alsaad, Hiba Najeh

    2012-01-01

    The free –COOH present in NSAIDs is thought to be responsible for the GI irritation associated with all traditional NSAIDs. Exploitation of mutual prodrugs is an approach wherein the NSAID is covalently bounded to a second pharmacologically active carrier/drug with the ultimate aim of reducing the gastric irritation. In this study some NSAIDs were conjugated with gabapentin via ester bonds using glycol spacers with the expectation of reducing gastric adverse effects and obtaining synergistic analgesic effects. The kinetics of ester hydrolysis were studied in two different non enzymatic buffer solutions at pH 1.2 and 7.4, as well as in 80% human plasma using HPLC with chloroform -methanol as mobile phase. Compounds 9a–c with ethylene glycol spacers showed significant stability at buffer solutions with half lives ranging from about 8–25 h, while the underwent a reasonable plasma hydrolysis (49%–88%) in 2 h. Compound 9d with a propylene glycol spacer shows a higher rate of enzymatic hydrolysis than the corresponding ethylene glycol compound 9c. The result of compounds 9a-c indicate that these compounds may be stable during their passage through the GIT until reaching the blood circulation. PMID:24281258

  12. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... directly to the atmosphere may be used on the air emission control equipment installed to comply with... satisfaction, that the total HAP emissions to the atmosphere from the glycol dehydration unit process vent are... demonstrates, to the Administrator's satisfaction, that total emissions to the atmosphere from the...

  13. Ethylene Glycol Adsorption and Reaction over CeOX(111) Thin Films

    SciTech Connect

    T Chen; D Mullins

    2011-12-31

    This study reports the interaction of ethylene glycol with well-ordered CeO{sub x}(111) thin film surfaces. Ethylene glycol initially adsorbs on fully oxidized CeO{sub 2}(111) and reduced CeO{sub 2-x}(111) through the formation of one C-O-Ce bond and then forms a second alkoxy bond after annealing. On fully oxidized CeO{sub 2}(111) both recombination of ethylene glycol and water desorption occur at low temperature leaving stable -OCH{sub 2}CH{sub 2}O- (ethylenedioxy) intermediates and oxygen vacancies on the surface. This ethylenedioxy intermediate goes through C-C bond scission to produce formate species which then react to produce CO and CO{sub 2}. The formation of water results in the reduction of the ceria. On a reduced CeO{sub 2-x}(111) surface the reaction selectivity shifts toward a dehydration process. The ethylenedioxy intermediate decomposes by breaking a C-O bond and converts into an enolate species. Similar to the reaction of acetaldehyde on reduced CeO{sub 2-x}(111), the enolate reacts to produce acetaldehyde, acetylene, and ethylene. The loss of O from ethylene glycol leads to a small amount of oxidation of the reduced ceria.

  14. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (EGBE) (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA is releasing the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessme...

  15. AN EVALUATION OF THE HUMAN CARCINOGENIC POTENTIAL OF ETHYLENE GLYCOL BUTYL ETHER (EGBE)

    EPA Science Inventory

    Background

    The position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, was developed in support of the Agency's evaluation of a petition from the...

  16. Molar Mass and Second Virial Coefficient of Polyethylene Glycol by Vapor Pressure Osmometry

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Checkal, Caleb; Saksa, Brian; Baka, Nadia; Modi, Kalpit; Rivera, Carlos

    2015-01-01

    In this laboratory experiment, students determine the number-average molar masses and second virial coefficients of polyethylene glycol (PEG) polymers ranging in molar mass from 200 to 1500 g mol[superscript -1] using vapor pressure osmometry (VPO). Students assess VPO in relation to accurate molar mass calculations of PEG polymers. Additionally,…

  17. Near-infrared laser-induced generation of three rare conformers of glycolic acid.

    PubMed

    Halasa, Anna; Lapinski, Leszek; Reva, Igor; Rostkowska, Hanna; Fausto, Rui; Nowak, Maciej J

    2014-07-31

    Structural transformations were induced in conformers of glycolic acid by selective excitation with monochromatic tunable near-infrared laser light. For the compound isolated in Ar matrixes, near-IR excitation led to generation of two higher-energy conformers (GAC; AAT) differing from the most stable SSC form by 180° rotation around the C-C bond. A detailed investigation of this transformation revealed that one conformer (GAC) is produced directly from the near-IR-excited most stable conformer. The other higher-energy conformer (AAT) was effectively generated only upon excitation of the primary photoproduct (GAC) with another near-IR photon. Once these higher-energy conformers of glycolic acid were generated in an Ar matrix, they could be subsequently transformed into one another upon selective near-IR excitations. Interestingly, no repopulation of the initial most stable SSC conformer occurred upon near-IR excitation of the higher-energy forms of the compound isolated in solid Ar. A dramatically different picture of near-IR-induced conformational transformations was observed for glycolic acid isolated in N2 matrixes. In this case, upon near-IR excitation, the most stable SSC form converted solely into a new conformer (SST), where the acid OH group is rotated by 180°. This conformational transformation was found to be photoreversible. Moreover, SST conformer, photoproduced in the N2 matrix, spontaneously converted to the most stable SSC form of glycolic acid, when the matrix was kept at cryogenic temperature and in the dark.

  18. Ethylene Glycol Adsorption and Reaction over CeOX(111) Thin Films

    SciTech Connect

    Mullins, David R; Chen, Tsung-Liang

    2011-01-01

    This study reports the interaction of ethylene glycol with well-ordered CeO{sub x}(111) thin film surfaces. Ethylene glycol initially adsorbs on fully oxidized CeO{sub 2}(111) and reduced CeO{sub 2-x}(111) through the formation of one C-O-Ce bond and then forms a second alkoxy bond after annealing. On fully oxidized CeO{sub 2}(111) both recombination of ethylene glycol and water desorption occur at low temperature leaving stable -OCH{sub 2}CH{sub 2}O- (ethylenedioxy) intermediates and oxygen vacancies on the surface. This ethylenedioxy intermediate goes through C-C bond scission to produce formate species which then react to produce CO and CO{sub 2}. The formation of water results in the reduction of the ceria. On a reduced CeO{sub 2-x}(111) surface the reaction selectivity shifts toward a dehydration process. The ethylenedioxy intermediate decomposes by breaking a C-O bond and converts into an enolate species. Similar to the reaction of acetaldehyde on reduced CeO{sub 2-x}(111), the enolate reacts to produce acetaldehyde, acetylene, and ethylene. The loss of O from ethylene glycol leads to a small amount of oxidation of the reduced ceria.

  19. Photorespiration and Glycolate Metabolism: A Re-examination and Correlation of Some Previous Studies 1

    PubMed Central

    Downton, W. J. S.; Tregunna, E. B.

    1968-01-01

    Some previous studies of photorespiration and glycolate oxidation were re-examined and correlated by infra-red CO2 analysis. Data about rate of photosynthesis and oxygen sensitivity indicated that complete inhibition of photosynthesis with 3-(3,4-dichlorophenyl)-1,1 dimethyl urea (DCMU) allowed dark respiration to continue in the light. Photorespiration was also inhibited. The oxygen sensitivity of glycolate-stimulated CO2 production was found to be compatible with the proposal that glycolate is a substrate of photorespiration. Both `in vivo' and `in vitro' studies of the alga Nitella flexilis have revealed a pathway of glycolate oxidation similar to that of higher plants. DCMU inhibition of photosynthesis by Nitella gave results similar to those for the monocotyledons tested. Under very low light intensity, carbon dioxide compensation in corn was measurable but was not sensitive to high oxygen concentration. It appears that the lack of photorespiration in this plant is not the end result of efficient internal recycling of CO2 to photosynthesis. PMID:16656863

  20. MICROWAVE-ACCELERATED SUZUKI CROSS-COUPLING REACTION IN POLYETHYLENE GLYCOL (PEG)

    EPA Science Inventory

    Polyethylene glycol (PEG) is found to be an inexpensive and nontoxic reaction medium for the microwave-assisted Suzuki cross-coupling of arylboronic acids with aryl halides. This environmentally friendly microwave protocol offers the ease of operation and enables the recyclabilit...