Sample records for n-vinyl pyrrolidone nvp

  1. Determination of N-vinyl-2-pyrrolidone and N-methyl-2-pyrrolidone in drugs using polypyrrole-based headspace solid-phase microextraction and gas chromatography-nitrogen-phosphorous detection.

    PubMed

    Mehdinia, Ali; Ghassempour, Alireza; Rafati, Hasan; Heydari, Rouhollah

    2007-03-21

    A headspace solid-phase microextraction and gas chromatography-nitrogen-phosphorous detection (HS-SPME-GC-NPD) method using polypyrrole (PPy) fibers has been introduced to determine two derivatives of pyrrolidone; N-vinyl-2-pyrrolidone (NVP) and N-methyl-2-pyrrolidone (NMP). Two types of PPy fibers, prepared using organic and aqueous media, were compared in terms of extraction efficiency and thermal stability. It was found that PPy film prepared using organic medium (i.e. acetonitrile) had higher extraction efficiency and more thermal stability compared to the film prepared in aqueous medium. To enhance the sensitivity of HS-SPME, the effects of pH, ionic strength, extraction time, extraction temperature and the headspace volume on the extraction efficiency were optimized. Using the results of this research, high sensitivity and selectivity had been achieved due to the combination of the high extraction efficiency of PPy film prepared in organic medium and the high sensitivity and selectivity of nitrogen-phosphorous detection. Linear range of the analytes was found to be between 1.0 and 1000 microg L(-1) with regression coefficients (R(2)) of 0.998 and 0.997 for NVP and NMP, consequently. Limits of detection (LODs) were 0.074 and 0.081 microg L(-1) for NVP and NMP, respectively. Relative standard deviation (R.S.D.) for five replications of analyses was found to be less than 6.0%. In real samples the mean recoveries were 94.81% and 94.15% for NVP and NMP, respectively. The results demonstrated the suitability of the HS-SPME technique for analyzing NVP and NMP in two different pharmaceutical matrices. In addition, the method was used for simultaneous detection of NVP, 2-pyrrolidone (2-Pyr), gamma-butyrolactone (GBL) and ethanolamine (EA) compounds.

  2. Mucoadhesive hydrogel microparticles based on poly (methacrylic acid-vinyl pyrrolidone)-chitosan for oral drug delivery.

    PubMed

    Sajeesh, S; Sharma, Chandra P

    2011-05-01

    The study was aimed at the evaluation of N-vinyl pyrrolidone (NVP) incorporated polymethacrylic acid-chitosan microparticles for oral drug delivery applications. Poly (methacrylic acid)-chitosan (PMC) and poly(methacrylic acid-vinyl pyrrolidone)-chitosan (PMVC) microparticles were prepared by an ionic-gelation method. Mucoadhesion behaviour of these particles was evaluated by ex-vivo adhesion method using freshly excised rat intestinal tissue. Cytotoxicity and absorption enhancing property of PMC and PMVC particles were evaluated on Caco 2 cell monolayers. Protease enzyme inhibition capability and insulin loading/release properties of these hydrogel particles was evaluated under in vitro experimental conditions. Addition of NVP units enhanced the mucoadhesion behavior of PMC particles on isolated rat intestinal tissue. Both PMC and PMVC particles were found non-toxic on Caco 2 cell monolayers and PMC particles was more effective in improving paracellular transport of fluorescent dextran across Caco 2 cell monolayers as compared to PMVC particles. However, protease inhibition efficacy of PMC particles was not significantly affected with NVP addition. NVP incorporation improved the insulin release properties of PMC microparticles at acidic pH. Hydrophilic modification seems to be an interesting approach in improving mucoadhesion capability of PMC microparticles.

  3. Surface characterization and protein interaction of a series of model poly[acrylonitrile-co-(N-vinyl pyrrolidone)] nanocarriers for drug targeting.

    PubMed

    Staufenbiel, Sven; Merino, Marian; Li, Wenzhong; Huang, Mao-Dong; Baudis, Stefan; Lendlein, Andreas; Müller, Rainer H; Wischke, Christian

    2015-05-15

    The surface properties of intravenously injected nanoparticles determine the acquired blood protein adsorption pattern and subsequently the organ distribution and cellular recognition. A series of poly[acrylonitrile-co-(N-vinyl pyrrolidone)] (PANcoNVP) model nanoparticles (133-181 nm) was synthesized, in which the surface properties were altered by changing the molar content of NVP (0-33.8 mol%) as the more hydrophilic repeating unit. The extent of achieved surface property variation was comprehensively characterized. The residual sodium dodecyl sulfate (SDS) content from the synthesis was in the range 0.3-1.6 μgml(-1), potentially contributing to the surface properties. Surface hydrophobicity was determined by Rose Bengal dye adsorption, hydrophobic interaction chromatography (HIC) and aqueous two-phase partitioning (TPP). Particle charge was quantified by zeta potential (ZP) measurements including ZP-pH profiles. The interaction with proteins was analyzed by ZP measurements in serum and by adsorption studies with single proteins. Compared to hydrophobic polystyrene model nanoparticles, all PANcoNVP particles were very hydrophilic. Differences in surface hydrophobicity could be detected, which did not linearly correlate with the systematically altered bulk composition of the PANcoNVP nanoparticles. This proves the high importance of a thorough surface characterization applying a full spectrum of methods, complementing predictions solely based on bulk polymer composition. Copyright © 2015. Published by Elsevier B.V.

  4. Effect of crosslinking concentration on properties of 3-(trimethoxysilyl) propyl methacrylate/N-vinyl pyrrolidone gels.

    PubMed

    Mohammed, Ameen Hadi; Ahmad, Mansor B; Ibrahim, Nor Azowa; Zainuddin, Norhazlin

    2018-02-13

    The incorporation of two different monomers, having different properties, in the same polymer molecule leads to the formation of new materials with great scientific and commercial importance. The basic requirements for polymeric materials in some areas of biomedical applications are that they are hydrophilic, having good mechanical and thermal properties, soft, and oxygen-permeable. A series of 3-(trimethoxysilyl) propyl methacrylate/N-vinyl pyrrolidone (TMSPM/NVP) xerogels containing different concentration of ethylene glycol dimethacrylate (EGDMA) as crosslinking agent were prepared by bulk polymerization to high conversion using BPO as initiator. The copolymers were characterized by FTIR. The corresponding hydrogels were obtained by swelling the xerogels in deionized water to equilibrium. Addition of EGDMA increases the transparency of xerogels and hydrogels. The minimum amount of EGDMA required to produce a transparent xerogel is 1%. All the Swelling parameters, including water content (EWC), volume fraction of polymer (ϕ 2 ) and weight loss during swelling decrease with increasing EGDMA. Young's and shear modulus (E and G) increase as EGDMA increases. The hydrogels were characterized in terms of modulus cross-linking density (v e and v t ) and polymer-solvent interaction parameters (χ). Thermal properties include TGA and glass transition temperature (T g ) enhance by adding EGDMA whereas the oxygen permeability (P) of hydrogels decreases as water content decrease. This study prepared and studied the properties for new copolymer (TMSPM-co-NVP) contains different amounts of (EGDMA). These copolymers possess new properties with potential use in different biomedical applications. The properties of the prepared hydrogels are fit with the standard properties of materials which should be used for contact lenses.

  5. Multi-stage Mass Spectrometry of Poly(vinyl pyrrolidone) and Its Vinyl Succinimide Copolymer Formed upon Exposure to Sodium Hypochlorite

    PubMed Central

    Fouquet, Thierry; Torimura, Masaki; Sato, Hiroaki

    2016-01-01

    The degradation routes of poly(vinyl pyrrolidone) (PVP) exposed to sodium hypochlorite (bleach) have been previously investigated using chemical analyses such as infrared spectroscopy. So far, no reports have proposed mass spectrometry (MS) as an alternative tool despite its capability to provide molecular and structural information using its single stage electrospray (ESI) or matrix assisted laser desorption ionization (MALDI) and multi stage (MSn) configurations, respectively. The present study thus reports on the characterization of PVP after its exposure to bleach by high resolution MALDI spiralTOF-MS and Kendrick mass defect analysis providing clues as to the formation of a vinyl pyrrolidone/vinyl succinimide copolymeric degradation product. A thorough investigation of the fragmentation pathways of PVP adducted with sodium and proton allows one main route to be described—namely the release of the pyrrolidone pendant group in a charge remote and charge driven mechanism, respectively. Extrapolating this fragmentation pathway, the oxidation of vinyl pyrrolidone into vinyl succinimide hypothesized from the single stage MS is validated by the detection of an alternative succinimide neutral loss in lieu of the pyrrolidone release in the ESI-MSn spectra of the aged PVP sample. It constitutes an example of application of multi-stage mass spectrometry for the characterization of the degradation of polymeric samples at a molecular level. PMID:27800293

  6. Synthesis and characterization of Pd-poly(N-vinyl-2-pyrrolidone)/KIT-5 nanocomposite as a polymer-inorganic hybrid catalyst for the Suzuki-Miyaura cross-coupling reaction

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

    Kalbasi, Roozbeh Javad, E-mail: rkalbasi@iaush.ac.ir; Mosaddegh, Neda

    2011-11-15

    Composite poly(N-vinyl-2-pyrrolidone)/KIT-5 (PVP/KIT-5) was prepared by in situ polymerization method and used as a support for palladium nanoparticles obtained through the reduction of Pd(OAc){sub 2} by hydrazine hydrate. The physical and chemical properties of the catalyst were investigated by XRD, FT-IR, UV-vis, TG, BET, SEM, and TEM techniques. The catalytic performance of this novel heterogeneous catalyst was determined for the Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid in the presence of water at room temperature. The stability of the nanocomposite catalyst was excellent and could be reused 8 times without much loss of activity in the Suzuki-Miyaura cross-couplingmore » reaction. - Graphical Abstract: Pd-poly(N-vinyl-2-pyrrolidone)/KIT-5 was prepared as an organic-inorganic hybrid catalyst for the Suzuki-Miyaura reaction. The stability of the catalyst was excellent and could be reused 8 times in the Suzuki-Miyaura reaction. Highlights: > Pd-poly(N-vinyl-2-pyrrolidone)/KIT-5 was prepared as a novel nanocomposite. > Nanocomposite was prepared based on a cage-type mesoporous system. > Catalyst showed excellent activity for Suzuki-Miyaura reaction in water. > Stability of the catalyst was excellent and could be reused 8 times.« less

  7. Hydrophilic porous magnetic poly(GMA-MBAA-NVP) composite microspheres containing oxirane groups: An efficient carrier for immobilizing penicillin G acylase

    NASA Astrophysics Data System (ADS)

    Xue, Ping; Su, Weiguang; Gu, Yaohua; Liu, Haifeng; Wang, Julan

    2015-03-01

    Magnetic hydrophilic polymeric microspheres containing oxirane groups were prepared by inverse suspension polymerization of glycidyl methacrylate (GMA), N, N‧-methylene bisacrylamide (MBAA) and N-vinyl pyrrolidone (NVP) in the existence of formamide, which were denoted as magnetic poly(GMA-MBAA-NVP) microspheres. The magnetic poly(GMA-MBAA-NVP) microspheres were characterized by scanning electron microscopy (SEM), FT-IR spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and so on. The results showed that poly(GMA-MBAA-NVP) microspheres possessed well spherical shape, narrow size distribution, abundant porous structure, reactive oxirane groups and superparamagnetic properties. Formamide used in the present work served as a modifier, a dispersant and a porogen to form final porous polymer microspheres. The penicillin G acylase (PGA) was covalently immobilized onto the magnetic microspheres through the reaction between the amino groups of enzyme and the oxirane groups on the microspheres for producing 6-aminopenicillanic acid (6-APA). The effects of GMA/NVP ratio and crosslink density on the activity of immobilized PGA were investigated. The highest apparent activity, enzyme loading and coupling yield of immobilized PGA were 821 IU/g, 65.3 mg/g and 42.3% respectively when the mass ratio of GMA/NVP was 1:1 and crosslink density was 60%. Compared with the free PGA, immobilized PGA showed a wider range of pH value and reaction temperature. The relative activity and reaction rate of immobilized PGA remained almost constant after 20 recycles. The magnetic poly(GMA-MBAA-NVP) microspheres would be very promising carriers for immobilizing enzymes in industrial application.

  8. Synthesis and Application of Pyrrolidone-containing Shale Inhibitors

    NASA Astrophysics Data System (ADS)

    Liu, Yonggui; Hou, Jie; Zhang, Yang; Yan, Jing; Song, Tao; Xu, Yongjun

    2018-03-01

    New generation polyamine inhibitors are amino-terminated polyethers with excellent inhibiting capabilities; they play a key role in borehole stabilization and reservoir protection. However, polyamine inhibitors are limited by their poor thermal stability, which can be attributed to the presence of ether bonds in their molecular structures. We propose a three-step synthesis approach fora novel pyrrolidone-containing polyamine inhibitor (DYNP) by introducing N-vinyl-2-pyrrolidone (NVP) on divinyloxyethane. This polyamine inhibitor exhibits an optimized molecular structure and has enhanced heat resistance. Characterizations by infrared (IR) spectroscopy and evaluation tests demonstrate several advantages of DYNP inhibitors, including excellent inhibiting capability (superior to similar materials such as polyamines), improved heat resistance (reasonable stability at temperatures up to 240°C), and good compatibility with both fresh water and salt water drilling fluids. These can be attributed to the presence of considerable amounts of amino groups in the repeating unit of DYNP molecules. The DYNP inhibitor was applied in over 20 boreholes in tight oil blocks in Daqing Oilfield to relieve hydration of formations with high shale contents. For instance, drilling in the 2033.5m horizontal section of Dragon 2 borehole was smooth, with a borehole diameter expansion ratio below 10%.

  9. Pyrolysis-gas chromatography-mass spectrometry for studying N-vinyl-2-pyrrolidone-co-vinyl acetate copolymers and their dissolution behaviour.

    PubMed

    Chojnacka, Aleksandra; Ghaffar, Abdul; Feilden, Andrew; Treacher, Kevin; Janssen, Hans-Gerd; Schoenmakers, Peter

    2011-11-14

    Knowledge on the solubility behaviour and dissolution rate of speciality and commodity polymers is very important for the use of such materials in high-tech applications. We have developed methods for the quantification and characterization of dissolved copolymers of N-vinyl-2-pyrrolidone (VP) and vinyl acetate (VA) during dissolution in water. The methods are based on pyrolysis (Py) performed in a programmed-temperature vaporization injector with subsequent identification and quantification of the components in the pyrolysate using capillary gas chromatography-mass spectrometry (GC-MS). By injecting large volumes and applying cryo-focussing at the top of the column, low detection limits could be achieved. The monomer ratio was found to have the greatest effect on the dissolution rate of the PVP-co-VA copolymers. The material with the highest amount of VA (50%) dissolves significantly slower than the other grades. Size-exclusion chromatography (SEC) and Py-GC-MS were used to measure molecular weights and average chemical compositions, respectively. Combined off-line SEC//Py-GC-MS was used to determine the copolymer composition (VP/VA ratio), as a function of the molecular weight for the pure polymers. In the dissolution experiments, a constant VP/VA ratio across the dissolution curve was observed for all copolymers analysed. This suggests a random distribution of the two monomers over the molecules. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Flavonoids preservation and release by methacrylic acid-grafted (N-vinyl-pyrrolidone).

    PubMed

    Parisi, Ortensia Ilaria; Puoci, Francesco; Iemma, Francesca; Curcio, Manuela; Cirillo, Giuseppe; Spizzirri, Umile Gianfranco; Picci, Nevio

    2013-01-01

    Flavonoids preservation and release. Synthesis of a polymeric material able to prevent thermal and photo degradation of a flavonoid model compound, such as (+)-catechin, and suitable for a controlled/sustained delivery of this molecule in gastro-intestinal simulating fluids. Methacrylic acid (MAA) was grafted onto poly(N-vinyl-pyrrolidone) (PVP) by a free radical grafting procedure involving a single-step reaction at room temperature. For this purpose, hydrogen peroxide/ascorbic acid redox pair was employed as water-soluble and biocompatible initiator system. FT-IR spectra confirmed the insertion of MAA onto the polymeric chain. Stability studies, performed under various conditions, such as freeze-thaw cycles, exposure to strong light, thermal stability studies under constant humidity and with light protection at different temperatures, showed the preservative properties of the polymeric material towards flavonoids. Furthermore, the biocompatibility was highlighted by Hen's Egg Test-Chorioallantoic Membrane assay and in vitro release studies demonstrated the possibility to employ PVP-MAA copolymer as a device for gastro-intestinal release of flavonoids. The coupling of good preservative properties together with biocompatibility and the usefulness as carrier in controlled release make this kind of material very interesting from an industrial point of view for different applications in food, pharmaceutical, and cosmetic fields.

  11. Catalytic Effect of Pd Clusters in the Poly( N-vinyl-2-pyrrolidone) Combustion

    NASA Astrophysics Data System (ADS)

    Schiavo, L.; De Nicola, S.; Carotenuto, G.

    2018-01-01

    Pd(0) is able to catalyze oxygen-involving reactions because of its capability to convert molecular oxygen to the very reactive atomic form. Consequently, the embedding of a little amount of Pd(0) clusters in polymeric phases can be technologically exploited to enhance the incineration kinetic of these polymers. The effect of nanostructuration on the Pd(0) catalytic activity in the polymer incineration reaction has been studied using poly( N-vinyl-2-pyrrolidone) ( \\overline{Mw} = 10,000 gmol-1) as polymeric model system. A change in the PVP incineration kinetic mechanism with significant increase in the reaction rate was experimentally found. The kinetic of the Pd(0)-catalyzed combustion has been studied by isothermal thermogravimetric analysis. After a short induction time, the combustion in presence of Pd(0) clusters shifted to a zero-order kinetic from a second-order kinetic control, which is operative in pure PVP combustion reaction. In addition, the activation energy resulted much lowered compared to the pure PVP incineration case (from 300 to 260 kJ/mol).

  12. Poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles-catalyzed hydrolysis of ammonia borane for hydrogen generation

    NASA Astrophysics Data System (ADS)

    Rakap, Murat

    2015-02-01

    The catalytic use of highly efficient poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles (4.2 ± 1.9 nm) in the hydrolysis of ammonia-borane is reported. The catalyst is prepared by co-reduction of two metal ions in ethanol/water mixture by an alcohol reduction method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Vis spectroscopy. They are recyclable and highly active for hydrogen generation from the hydrolysis of ammonia-borane even at very low concentrations and temperature, providing a record numbers of average turnover frequency value (125 mol H2/mol cat.min-1) and maximum hydrogen generation rate (3468 L H2 min-1 (mol cat)-1). They also provide activation energy of 51.7 ± 2 kJ/mol for the hydrolysis of ammonia borane.

  13. 40 CFR 180.1130 - N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false N-(n-octyl)-2-pyrrolidone and N-(n... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1130 N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a tolerance. N-(n-octyl)-2...

  14. 40 CFR 180.1130 - N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false N-(n-octyl)-2-pyrrolidone and N-(n... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1130 N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a tolerance. N-(n-octyl)-2...

  15. Bioreactor validation and biocompatibility of Ag/poly(N-vinyl-2-pyrrolidone) hydrogel nanocomposites.

    PubMed

    Jovanović, Zeljka; Radosavljević, Aleksandra; Kačarević-Popović, Zorica; Stojkovska, Jasmina; Perić-Grujić, Aleksandra; Ristić, Mirjana; Matić, Ivana Z; Juranić, Zorica D; Obradovic, Bojana; Mišković-Stanković, Vesna

    2013-05-01

    Silver/poly(N-vinyl-2-pyrrolidone) (Ag/PVP) nanocomposites containing Ag nanoparticles at different concentrations were synthesized using γ-irradiation. Cytotoxicity of the obtained nanocomposites was determined by MTT assay in monolayer cultures of normal human immunocompetent peripheral blood mononuclear cells (PBMC) that were either non-stimulated or stimulated to proliferate by mitogen phytohemagglutinin (PHA), as well as in human cervix adenocarcinoma cell (HeLa) cultures. Silver release kinetics and mechanical properties of nanocomposites were investigated under bioreactor conditions in the simulated body fluid (SBF) at 37°C. The release of silver was monitored under static conditions, and in two types of bioreactors: perfusion bioreactors and a bioreactor with dynamic compression coupled with SBF perfusion simulating in vivo conditions in articular cartilage. Ag/PVP nanocomposites exhibited slight cytotoxic effects against PBMC at the estimated concentration of 0.4 μmol dm(-3), with negligible variations observed amongst different cell cultures investigated. Studies of the silver release kinetics indicated internal diffusion as the rate limiting step, determined by statistically comparable results obtained at all investigated conditions. However, silver release rate was slightly higher in the bioreactor with dynamic compression coupled with SBF perfusion as compared to the other two systems indicating the influence of dynamic compression. Modelling of silver release kinetics revealed potentials for optimization of Ag/PVP nanocomposites for particular applications as wound dressings or soft tissue implants. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. The Impact of the Polymer Chain Length on the Catalytic Activity of Poly(N-vinyl-2-pyrrolidone)-supported Gold Nanoclusters.

    PubMed

    Haesuwannakij, Setsiri; Kimura, Tetsunari; Furutani, Yuji; Okumura, Kazu; Kokubo, Ken; Sakata, Takao; Yasuda, Hidehiro; Yakiyama, Yumi; Sakurai, Hidehiro

    2017-08-29

    Poly(N-vinyl-2-pyrrolidone) (PVP) of varying molecular weight (M w  = 40-360 kDa) were employed to stabilize gold nanoclusters of varying size. The resulting Au:PVP clusters were subsequently used as catalysts for a kinetic study on the sized-dependent aerobic oxidation of 1-indanol, which was monitored by time-resolved in situ infrared spectroscopy. The obtained results suggest that the catalytic behaviour is intimately correlated to the size of the clusters, which in turn depends on the molecular weight of the PVPs. The highest catalytic activity was observed for clusters with a core size of ~7 nm, and the size of the cluster should increase with the molecular weight of the polymer in order to maintain optimal catalytic activity. Studies on the electronic and colloid structure of these clusters revealed that the negative charge density on the cluster surface also strongly depends on the molecular weight of the stabilizing polymers.

  17. Preparation and Properties of Electrospun Poly (Vinyl Pyrrolidone)/Cellulose Nanocrystal/Silver Nanoparticle Composite Fibers

    PubMed Central

    Huang, Siwei; Zhou, Ling; Li, Mei-Chun; Wu, Qinglin; Kojima, Yoichi; Zhou, Dingguo

    2016-01-01

    Poly (vinyl pyrrolidone) (PVP)/cellulose nanocrystal (CNC)/silver nanoparticle composite fibers were prepared via electrospinning using N,N′-dimethylformamide (DMF) as a solvent. Rheology, morphology, thermal properties, mechanical properties, and antimicrobial activity of nanocomposites were characterized as a function of material composition. The PVP/CNC/Ag electrospun suspensions exhibited higher conductivity and better rheological properties compared with those of the pure PVP solution. The average diameter of the PVP electrospun fibers decreased with the increase in the amount of CNCs and Ag nanoparticles. Thermal stability of electrospun composite fibers was decreased with the addition of CNCs. The CNCs help increase the composite tensile strength, while the elongation at break decreased. The composite fibers included Ag nanoparticles showed improved antimicrobial activity against both the Gram-negative bacterium Escherichia coli (E. coli) and the Gram-positive bacterium Staphylococcus aureus (S. aureus). The enhanced strength and antimicrobial performances of PVP/CNC/Ag electrospun composite fibers make the mat material an attractive candidate for application in the biomedical field. PMID:28773644

  18. Studies on biodegradable and crosslinkable poly(castor oil fumarate)/poly(propylene fumarate) composite adhesive as a potential injectable biomaterial.

    PubMed

    Mitha, M K; Jayabalan, M

    2009-12-01

    Biodegradable hydroxyl terminated-poly(castor oil fumarate) (HT-PCF) and poly(propylene fumarate) (HT-PPF) resins were synthesized as an injectable and in situ-cross linkable polyester resins for orthopedic applications. An injectable adhesive formulation containing this resin blend, N-vinyl pyrrolidone (NVP), hydroxy apatite, free radical initiator and accelerator was developed. The Composite adhesives containing the ratio of resin blend and NVP, 2.1:1.5, 2.1:1.2 and 2.1:1.0 set fast with tolerable exothermic temperature as a three dimensionally cross linked toughened material. Crosslink density and mechanical properties of the crosslinked composite increase with increase of NVP. The present crosslinked composite has hydrophilic character and cytocompatibility with L929 fibroblast cells.

  19. Development of a P((MAA-co-NVP)-g-EG) Hydrogel Platform for Oral Protein Delivery: Effects of Hydrogel Composition on Environmental Response and Protein Partitioning.

    PubMed

    Steichen, Stephanie; O'Connor, Colleen; Peppas, Nicholas A

    2017-01-01

    Hydrogels based upon terpolymers of methacrylic acid, N-vinyl pyrrolidone, and poly(ethylene glycol) are developed and characterized for their ability to respond to changes in environmental pH and to partition protein therapeutics of varying molecular weights and isoelectric points. P((MAA-co-NVP)-g-EG) hydrogels are synthesized with PEG-based cross-linking agents of varying length and incorporation densities. The composition is confirmed using FT-IR spectroscopy and shows peak shifts indicating hydrogen bonding. Scanning electron microscopy reveals microparticles with an irregular, planar morphology. The pH-responsive behavior of the hydrogels is confirmed under equilibrium and dynamic conditions, with the hydrogel collapsed at acidic pH and swollen at neutral pH. The ability of the hydrogels to partition model protein therapeutics at varying pH and ionic strength is evaluated using three model proteins: insulin, porcine growth hormone, and ovalbumin. Finally, the microparticles are evaluated for adverse interactions with two model intestinal cell lines and show minimal cytotoxicity at concentrations below 5 mg mL -1 . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Polysulfone hemodiafiltration membranes with enhanced anti-fouling and hemocompatibility modified by poly(vinyl pyrrolidone) via in situ cross-linked polymerization.

    PubMed

    Zhu, Lijing; Song, Haiming; Wang, Jiarong; Xue, Lixin

    2017-05-01

    Poly(vinyl pyrrolidone) (PVP) and its copolymers have been widely employed for the modification of hemodiafiltration membranes due to their excellent hydrophilicity, antifouling and hemocompatibility. However, challenges still remain to simplify the modification procedure and to improve the utilization efficiency. In this paper, antifouling and hemocompatibility polysulfone (PSf) hemodiafiltration membranes were fabricated via in situ cross-linked polymerization of vinyl pyrrolidone (VP) and vinyltriethoxysilane (VTEOS) in PSf solutions and non-solvent induced phase separation (NIPS) technique. The prepared membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which suggested that VP and VTEOS have been cross-linked copolymerized in PSf membranes. The modified PSf membranes with high polymer content showed improved hydrophilicity, ultrafiltration and protein antifouling ability. In addition, the modified PSf membranes showed lower protein adsorption, inhibited platelet adhesion and deformation, prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), and decreased the content of fibrinogen (FIB) transferring to fibrin, indicating enhanced hemocompatibility. In a word, the present work provides a simple and effective one-step modification method to construct PSf membranes with improved hydrophilicity, antifouling and hemocompatibility. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Analysis of nevirapine (NVP) resistance in Ugandan infants who were HIV infected despite receiving single-Dose (SD) NVP versus SD NVP plus daily NVP up to 6 weeks of age to prevent HIV vertical transmission.

    PubMed

    Church, Jessica D; Omer, Saad B; Guay, Laura A; Huang, Wei; Lidstrom, Jessica; Musoke, Philippa; Mmiro, Francis; Jackson, J Brooks; Eshleman, Susan H

    2008-10-01

    Single-dose nevirapine (SD NVP) at birth plus NVP prophylaxis for the infant up to 6 weeks of age is superior to SD NVP alone for prevention of vertical transmission of human immunodeficiency virus (HIV) through breastfeeding. We analyzed NVP resistance in HIV-infected Ugandan infants who received either SD NVP or extended NVP prophylaxis. We tested plasma HIV by using a genotyping assay (ViroSeq; Celera Diagnostics), a phenotypic resistance assay (PhenoSense; Monogram Biosciences), and sensitive point mutation assay (LigAmp, for K103N, Y181C, and G190A). When infants were 6 weeks old, ViroSeq detected NVP resistance in a higher proportion of infants in the extended NVP arm than in the SD NVP arm (21 of 25 [84%] vs. 12 of 24 [50%]; P = .01). Similar results were obtained with LigAmp and PhenoSense. In both study arms, infants who were HIV infected at birth frequently had NVP resistance detected. In contrast, infants in the extended NVP arm who were HIV infected after birth were more likely to have resistance detected at 6 weeks, compared with infants in the SD NVP arm. The use of extended NVP prophylaxis was also associated with detection of NVP resistance by ViroSeq at 6 months (7 of 7 [100%] infants in the extended NVP arm had resistance detected, compared with 1 of 6 [16.7%] infants in the SD NVP arm; P = .005). The use of extended NVP prophylaxis was associated with increased selection for and persistence of NVP resistance in HIV-infected Ugandan infants.

  2. 21 CFR 500.1410 - N-methyl-2-pyrrolidone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false N-methyl-2-pyrrolidone. 500.1410 Section 500.1410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Used in Food-Producing Animals § 500.1410 N-methyl-2-pyrrolidone. (a) Standard for residues. No...

  3. 21 CFR 500.1410 - N-methyl-2-pyrrolidone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false N-methyl-2-pyrrolidone. 500.1410 Section 500.1410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Used in Food-Producing Animals § 500.1410 N-methyl-2-pyrrolidone. (a) Standard for residues. No...

  4. Methacrylated monosaccharides as the modifiers for carbochain polymers: Synthesis, mechanical/thermal properties and biodegradability of hybrids

    NASA Astrophysics Data System (ADS)

    Yakushev, P.; Bershtein, V.; Bukowska-Śluz, I.; Sobiesiak, M.; Gawdzik, B.

    2016-05-01

    Methacrylated derivatives of glucose (MGLU) and galactose (MGAL) were synthesized by the procedure described by Vogel, and their copolymers with methyl methacrylate (MMA) and MMA/N-vinyl pyrrolidone (MMA/NVP) (1:1) mixture were obtained with the aim to modify some properties of carbochain polymers, in particular to generate their biodegradability. These hybrids of synthetic and natural products, with 10, 20 or 30 wt. % modifiers, were characterized by DMA and TGA methods and in the biodegradation tests. Increasing Tg values by 20-30°C was registered in all cases whereas thermal stability was improved only for PMMA due to modification. On the contrary, only for hybrids based on hygroscopic MMA/NVP copolymer the essential biodegradability could be generated.

  5. Improving amphiphilic polypropylenes by grafting poly(vinylpyrrolidone) and poly(ethylene glycol) methacrylate segments on a polypropylene microporous membrane

    NASA Astrophysics Data System (ADS)

    Chen, Huirong; Ma, Wenzhong; Xia, Yanping; Gu, Yi; Cao, Zheng; Liu, Chunlin; Yang, Haicun; Tao, Shengxi; Geng, Haoran; Tao, Guoliang; Matsuyama, Hideto

    2017-10-01

    An amphiphilic polypropylene-g-poly[vinylpyrrolidone-co-poly(ethylene glycol) methacrylate] (PP-g-(NVP-co-PEGMA)) modifier was prepared by melt grafting polymerization using N-vinyl pyrrolidone (NVP) as the grafting monomer and poly(ethylene glycol) (PEGMA) as the comonomer. Fourier transform infrared (FTIR) spectroscopy and elemental analysis showed that the hydrophilic branched chains (NVP-g-PEGMA) were successfully grafted to polypropylene (PP) macromolecular chains. The largest NVP grafting degree for PP-g-(NVP-co-PEGMA) (up to 20.4%) was obtained when the mass ratio of PP/NVP/PEGMA was 100/30/15. Hydrophilic PP microporous membranes were prepared by stretching cast films of PP/PP-g-(NVP-co-PEGMA) blends. The membrane thermostability (including the modifier) was better than that of the pure PP membrane with a similar surface pore structure. The porosity of the modified membranes was only slightly lower than that of the pure PP membranes. Contact angle measurements were used to examine the hydrophilicity of the membranes. The water contact angle of the membranes decreased when PP-g-(NVP-co-PEGMA) was added, and the minimum contact angle was 64.5°. Therefore, this work provides a good application for stretched hydrophilic PP membrane fabrication.

  6. Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

    PubMed

    Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

    2014-12-01

    N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Radiation preparation of drug carriers based polyacrylic acid (PAAc) using poly(vinyl pyrrolidone) (PVP) as a template polymer

    NASA Astrophysics Data System (ADS)

    Abd El-Rehim, H. A.; Hegazy, E. A.; Khalil, F. H.; Hamed, N. A.

    2007-01-01

    The present study deals with the radiation synthesis of stimuli response hydrophilic polymers from polyacrylic acid (PAAc). To maintain the property of PAAc and control the water swellibility for its application as a drug delivery system, radiation polymerization of AAc in the presence of poly(vinyl pyrrolidone) (PVP) as a template polymer was carried out. Characterization of the prepared PAA/PVP inter-polymer complex was investigated by determining gel content, swelling property, hydrogel microstructure and the release rate of caffeine as a model drug. The release rate of caffeine from the PAA/PVP inter-polymer complexes showed pH-dependency, and seemed to be mainly controlled by the dissolution rate of the complex above a p Ka of PAAc. The prepared inter-polymer complex could be used for application as drug carriers.

  8. Synthesis and characterization of core-shell gold nanoparticles with poly(vinyl pyrrolidone) from a new precursor salt

    NASA Astrophysics Data System (ADS)

    Behera, M.; Ram, S.

    2013-02-01

    In this article, we report a facile one-step chemical synthesis of gold (Au) nanoparticles (GNPs) from a new precursor salt i.e., gold hydroxide in the presence of poly(vinyl pyrrolidone) (PVP) polymer. The non-aqueous dispersion of GNPs was comprehensively characterized by UV-Visible, FTIR, zeta potential, and transmission electron microscope (TEM). A strong surface plasmon resonance band at 529 nm in the UV-Visible spectrum confirms the formation of GNPs in the Au colloid. The FTIR spectroscopic results showed that PVP molecules get chemisorbed onto the surface of GNP via O-atom of carbonyl group. A negative zeta potential of (-)16 mV reveals accumulation of nonbonding electrons of O-atom of carbonyl group of PVP molecules on the nanosurface of GNP. TEM images demonstrate a core-shell nanostructure with an Au-crystalline core covered by a thin amorphous PVP-shell. PVP-capped GNPs could be a potential candidate for bio-sensing, catalysis, and other applications.

  9. Effects of N-vinylpyrrolidone (NVP) containing polyelectrolytes on surface properties of conventional glass-ionomer cements (GIC).

    PubMed

    Moshaverinia, Alireza; Roohpour, Nima; Ansari, Sahar; Moshaverinia, Maryam; Schricker, Scott; Darr, Jawwad A; Rehman, Ihtesham U

    2009-10-01

    It has been found that polyacids containing an N-vinylpyrrolidinone (NVP) comonomer produces a glass inomer cement with improved mechanical and handling properties. The objective of this study was to investigate the effect of NVP modified polyelectrolytes on the surface properties and shear bond strength to dentin of glass ionomer cements. Poly(acrylic acid (AA)-co-itaconic acid (IA)-co-N-vinylpyrrolidone) was synthesized by free radical polymerization. The terpolymer was characterized using (1)H NMR, FTIR spectroscopy and viscometry for solution properties. The synthesized polymers were used in glass ionomer cement formulations (Fuji II commercial GIC). Surface properties (wettability) of modified cements were studied by water contact angle measurements as a function of time. Work of adhesion values of different surfaces was also determined. The effect of NVP modified polyacid, on bond strength of glass-ionomer cement to dentin was also investigated. The mean data obtained from contact angle and bonding strength measurements were subjected to one- and two-way analysis of variance (ANOVA) at alpha=0.05. Results showed that NVP modified glass ionomer cements showed significantly lower contact angles (theta=47 degrees) and higher work of adhesion (WA=59.4 erg/cm(2)) in comparison to commercially available Fuji II GIC (theta=60 degrees and WA=50.3 erg/cm(2), respectively). The wettability of dentin surfaces conditioned with NVP containing terpolymer was higher (theta=21 degrees, WA=74.2 erg/cm(2)) than dentin conditioned with Fuji conditioner (theta=30 degrees, WA=69 erg/cm(2)). The experimental cement also showed higher but not statistically significant values for shear bond strength to dentin (7.8 MPa), when compared to control group (7.3 MPa). It was concluded that NVP containing polyelectrolytes are better dentin conditioners than the commercially available dentin conditioner (Fuji Cavity Conditioner, GC). NVP containing terpolymers can enhance the surface

  10. Fabrication of high quality carbonaceous coating on Cu nanoparticle using poly(vinyl pyrrolidone) and its application for oxidation prevention

    NASA Astrophysics Data System (ADS)

    Pyo, Youngjun; Choi, Dahyun; Son, Yeon-Ho; Kang, Suhee; Yoon, Eric H.; Jung, Seung-Boo; Kim, Yongil; Sunyong Lee, Caroline

    2016-05-01

    A novel method of carbonaceous coating on the surface of copper particles was developed through a chemical vapor deposition (CVD) process to prevent the oxidation of copper nanoparticles (CNPs). The types of poly(vinyl pyrrolidone) (PVP) used were K-12 (M W 3,500) and K-30 (M W 45,000). The amounts of PVP used ranged from 10 to 50 wt %. Additionally, processing temperatures of 900 and 875 °C were tested and compared. The optimum CVD process conditions for the carbonaceous coating were as follows: 875 °C processing temperature, 50 wt % K12 PVP solution, and gas conditions of \\text{Ar}:\\text{H}2 = 1:1. The resistivity change in the fabricated copper pattern was confirmed that the initial resistivity value of the ink with a mixing ratio of carbonaceous-coated CNPs to 1-octanethiol-coated CNPs of 4:6 (w/w) maintained its initial resistivity value of 2.93 × 10-7 Ω·m for more than 210 days.

  11. Development of swellable local implants of a polyethyleneimine-poly(vinyl pyrrolidone) (PEI-PVP) hydrogel as a socket filler.

    PubMed

    Chang, Ching-Wen; Ho, Hsiu-O; Lo, Yi-June; Lee, Sheng-Yang; Yang, You-Ren; Sheu, Ming-Thau

    2012-01-01

    In this study, hydrogels composed of polyethyleneimine (PEI) and poly(vinyl pyrrolidone) K90 (PVP) cross-linked with various concentrations (0, 0.125, 0.25 and 0.5%) of glutaraldehyde were evaluated as a hydrogel filler for the local delivery of lidocaine after tooth extraction. The drug-release kinetics, swellability, cytotoxicity and wound healing after tooth extraction of these non-cross-linked and cross-linked PEI-PVP hydrogels were examined in male beagles and compared to values using Spongostan(®). Results demonstrated that the extent of cross-linking influenced the swelling of the resulting hydrogel, but the drug-release rates were similar. No significant changes were observed in gingival fibroblasts in contact with the PEI- PVP hydrogels or Spongostan(®). In the in vivo study, PEI-PVP hydrogels showed good retention in the socket for 2 days and showed comparable wound-healing rates within 2 weeks with those of Spongostan(®). In conclusion, PEI-PVP hydrogels are suitable for use as socket-dressing materials, and the release of local anaesthesia from PEI-PVP hydrogels can be sustained for a desirable period of time to prevent pain after a tooth extraction.

  12. N-alkyl pyrrolidone ether podands as versatile alkali metal ion chelants.

    PubMed

    Perrin, Andrea; Myers, Dominic; Fucke, Katharina; Musa, Osama M; Steed, Jonathan W

    2014-02-28

    This work explores the coordination chemistry of a bis(pyrrolidone) ether ligand. Pyrrolidones are commercially important functional groups because of the high polarity and hence high hydrophilicity and surface affinity. An array of alkali metal ion complexes of a podand bearing two pendant pyrrolidone functionalities, namely 1-{2-[2-(2-oxo-pyrrolid-1-yl)-ethoxy]-ethyl}-pyrrolid-2-one (1) are reported. Reaction of this ligand with sodium hexafluorophosphate gives two discrete species of formulae [Na(1)2]PF6 (3) and [Na3(H2O)2(μ-1)2](PF6)3 (4), and a coordination polymer {[Na3(μ3-1)3(μ2-1)](PF6)3}n (5). The same reaction in methanol gives a 1 : 1 complex, namely [Na2(μ-1)2(MeOH)2](PF6)2 (6). Use of tetraphenyl borate as a less coordinating counter ion gives [Na2(1)2(H2O)4](BPh4)2 (7) and [Na2(1)4](BPh4)2 (8). Two potassium complexes have also been isolated, a monomer [K(1)2]PF6 (9) and a cyclic tetramer [K4(μ4-H2O)2(μ-1)4](PF6)4 (10). The structures illustrate the highly polar nature of the amide carbonyl moiety within bis(pyrrolidone) ethers with longer interactions to the ether oxygen atom. The zinc complex is also reported and {[ZnCl2(μ-1)]}n (11) exhibits bonding only to the carbonyl moieties. The ether oxygen atom is not necessary for Na(+) complexation as exemplified by the structure of the sodium complex of the analogue 1,3-bis(pyrrolid-2-on-1-yl)butane (2). Reaction of compound 1 with lithium salts results in isolation of the protonated ligand.

  13. Review of NVP and HG and Early Pharmacotherapeutic Intervention

    PubMed Central

    Clark, Shannon M.; Costantine, Maged M.; Hankins, Gary D. V.

    2012-01-01

    NVP occurs in 50–90% of pregnancies, making it a common medical condition in pregnancy. Women present differently with any combination of signs and symptoms. It is appropriate to take the pregnancy-related versus nonpregnancy-related approach when determining the cause of nausea and vomiting but other causes should be considered. The most common etiologies for NVP include the hormonal changes associated with pregnancy, the physiologic changes in the gastrointestinal tract, and a genetic predisposition. Up to 10% of women will require pharmacotherapy to treat the symptoms of NVP despite conservative measures. ACOG currently recommends that a combination of oral pyridoxine hydrochloride and doxylamine succinate be used as first-line treatment for NVP if pyridoxine monotherapy does not relieve symptoms. A review of NVP and early pharmacotherapeutic management is presented due to the fact that NVP is largely undertreated, and investigations into the safe and effective pharmacotherapies available to treat NVP are lacking. PMID:22190950

  14. Synthesis and evaluation of acryloylated starch-g-poly (Acrylamide/Vinylmethacrylate/1-Vinyl-2-pyrrolidone) crosslinked terpolymer functionalized by dimethylphenylvinylsilane derivative as a novel polymer-flooding agent.

    PubMed

    El-Hoshoudy, A N; Desouky, S M

    2018-05-16

    Starch is a natural biopolymer that subjected to various chemical modifications through different industrial applications. Molecular structure of starch allow its grafting with different vinyl monomers in the presence of crosslinking agents to synthesize cross-linked hydrogels, which used in enhanced oil recovery (EOR) applications, water shutoff and drag reduction. Application of native starch in the field of petroleum reservoirs as a flooding agent suffer from some limitations concerned with microbial degradation, thermal and salinity resistance under harsh petroleum reservoir conditions. In the current research, we stated the synthesis of acryloylated starch then it's grafting with poly (Acrylamide/Vinylmethacrylate/1-Vinyl-2-pyrrolidone) terpolymer in presence of dimethylphenylvinylsilane through emulsification polymerization. Characterization and structure determination occur by different spectroscopic techniques as stated throughout the manuscript. Rheological and solution properties carried out as a function of shear rate, salinity and temperature at simulated reservoir conditions. Flooding tests carried out through linear-dimensional sandstone model at simulated reservoir conditions, and recovered oil amount calculated on volumetric basis. The obtained results indicate that the prepared starch-g-terpolymer can tolerate to severe flooding conditions of high temperature and salinity, moreover it can increase recovery factor up to 49% of residual oil saturation so considered as a promised EOR candidate. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Pyrrolidon carboxypeptidase activities in the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-ovary axes of rats with mammary gland cancer induced by N-methyl nitrosourea.

    PubMed

    Carrera, M P; Ramírez-Expósito, M J; Valenzuela, M T; García, M J; Mayas, M D; Arias de Saavedra, J M; Sánchez, R; Pérez, M C; Martínez-Martos, J M

    2005-02-01

    Pyrrolidon carboxypeptidase is an omega-peptidase that hydrolyses N-terminal pyroglutamyl residues from biologically active peptides such as gonadotropin-releasing and thyrotrophin-releasing hormones. We previously described a decrease in both rat and human pyrrolidon carboxypeptidase activity with breast cancer, suggesting that gonadotropin-releasing hormone may be an important local intracrine, autocrine and/or paracrine hormonal factor in the pathogenesis of breast cancer while playing a role in the tumoral process. However, the other susceptible substrate of pyrrolidon carboxypeptidase, thyrotrophin-releasing hormone, may also be modified with breast cancer, supporting an association between breast cancer and thyroid disorders. The present work analyses soluble and membrane-bound pyrrolidon carboxypeptidase activities in the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-ovary axes in N-methyl nitrosourea-induced breast cancer in rats. Our aim was to determine the possible relationship between gonadotropin-releasing hormone and thyrotrophin-releasing hormone regulation through pyrrolidon carboxypeptidase activity. We propose that pyrrolidon carboxypeptidase activity dysregulation at various local and systemic levels may participate in the initiation, promotion and progression of breast cancer induced in rat by N-methyl nitrosourea through the increase in gonadotropin-releasing hormone. Since pyrrolidon carboxypeptidase activity also acts on thyrotrophin-releasing hormone, the dysregulation of this enzyme's activity could indirectly affect hypothalamus-pituitary-thyroid axis function, and thus potentially represent a link between the diseases of thyroid and breast cancer.

  16. Preparation of hydrophilic monolithic capillary column by in situ photo-polymerization of N-vinyl-2-pyrrolidinone and acrylamide for highly selective and sensitive enrichment of N-linked glycopeptides.

    PubMed

    Jiang, Hao; Yuan, Huiming; Qu, Yanyan; Liang, Yu; Jiang, Bo; Wu, Qi; Deng, Nan; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2016-01-01

    In this study, a novel kind of amide functionalized hydrophilic monolith was synthesized by the in situ photo-polymerization of N-vinyl-2-pyrrolidinone (NVP), acrylamide (AM), and N, N'-methylenebisacrylamide (MBA) in a UV transparent capillary, and successfully applied for hydrophilic interaction chromatography (HILIC) based enrichment of N-linked glycopeptides. With 2 μg of the tryptic digests of IgG as the sample, after enrichment, 18 glycopeptides could be identified by MALDI-TOF/TOF MS analysis. Furthermore, with the mixture of BSA and IgG digests (10,000:1, m/m) as the sample, 6 N-linked glycopeptides were unambiguously identified after enrichment, indicating the high selectivity and good specificity of such material. Moreover, such a monolithic capillary column was also applied for the N-glycosylation sites profiling of 6 μg protein digests from HeLa cells and 1 μL human serum. In total, 530 and 262 unique N-glycosylated peptides were identified, respectively, corresponding to 282 and 124N-glycoproteins, demonstrating its great potential for the large scale glycoproteomics analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Charge transfer interactions in oligomer coated gold nanoclusters

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

    Newmai, M. Boazbou; Kumar, Pandian Senthil, E-mail: duplasmonics@gmail.com

    Gold nanoclusters were synthesized by a bottom-up synergistic approach of in-situ oligomerization of the monomer, N-vinyl pyrrolidone (NVP) and simultaneous weak reduction of Au-NVP complexes in the absence of any other external energy sources, thereby making these tiny gold clusters as the most elemental building blocks to construct further novel nano/microstructures with application potentials. It is well-known that metal clusters with less than 2 nm size do not show the usual surface plasmon band, because of the presence of a band-gap at the fermi level. Nevertheless, our present oligomer coated gold clusters show a discrete intense band at around 630 nm, whichmore » could very well be attributed to the charge transfer between the oligomer chain and the surface Au atoms. Such kind of sacrificial plasmon induced charge transfer interaction, observed for the very first time to the best of our knowledge, were also strongly corroborated through the enhancement / shifting of specific vibrational / rotational peaks as observed from the FTIR and Raman measurements as a function of the metal oxidation states, thus representing a new prototype for an efficient solar energy conversion probe.« less

  18. Monomer functionalized silica coated with Ag nanoparticles for enhanced SERS hotspots

    NASA Astrophysics Data System (ADS)

    Newmai, M. Boazbou; Verma, Manoj; Kumar, P. Senthil

    2018-05-01

    Mesoporous silica (SiO2) spheres are well-known for their excellent chromatographic properties such as the relatively high specific surface, large pore volume, uniform particle size, narrow pore size distribution with favorable pore connectivity; whereas the noble metal Ag nanoparticles have unique size/shape dependant surface plasmon resonance with wide ranging applications. Thus, the desire to synchronize both their properties for specific applications has naturally prompted research in the design and synthesis of core-shell type novel nanoAg@mesoSiO2 nanocomposites, which display potential utility in applications such as photothermal therapy, photocatalysis, molecular sensing, and photovoltaics. In the present work, SiO2 spheres were carefully functionalized with the monomer, N-vinyl pyrrolidone (NVP), which cohesively controls the uniform mass transfer of Ag+ metal ions, thereby enabling its sequential reduction to zerovalent Ag (in the presence of slightly excess NaOH) by electron transfer from nucleophilic attack of the NVP vinyl group by the water molecules even under ambient conditions. Complete metal nanoshell coverage of the silica surface was obtained after multiple Ag deposition cycles, as systematically confirmed from the BET, TEM, optical and FTIR characterization. Our present Ag-coated silica spheres were directly utilized as viable SERS substrates with high sensitivity in contrast with other long chain polymer/surfactant coated silica spheres, owing to the presence of significant number of nanogaps enhanced SERS 'hotspots', which were methodically analyzed utilizing two example analytes, such as crystal violet (CV) and calendula officinalis (CaF).

  19. Studies on biodegradation of crosslinked hydroxy terminated-poly(proplyene fumarate) and formation of scaffold for orthopedic applications.

    PubMed

    Shalumon, K T; Jayabalan, M

    2009-12-01

    Biodegradation of crosslinked-hydroxy terminated-poly(proplyene fumarate) (X-HTPPF) has been studied in simulated physiological media to assess the formation of porous scaffold structure for bone growth and remodeling in load bearing orthopedic applications. Variation in crosslink density and surface hydrophilicity of X-HTPPF are observed due to non-stoichiometric mass of reacting partners. These variations influence absorption of the medium and biodegradation during aging. Though the initial absorption of medium is relatively higher with the crosslinked polymer (PNVP1) having 63.6% HT-PPF and 36.4% comonomer n-vinyl pyrrolidone (NVP) during the initial period of aging, the weight loss due to subsequent degradation with time is relatively lesser. PNVP1 undergo slow degradation with formation of fibril structure on the surface. The present crosslinked material PNVP1 is a candidate for the load bearing orthopedic applications.

  20. Employment of ultrasonic irradiation for production of poly(vinyl pyrrolidone)/modified alpha manganese dioxide nanocomposites: Morphology, thermal and optical characterization.

    PubMed

    Mallakpour, Shadpour; Abdolmaleki, Amir; Tabebordbar, Hashem

    2018-03-01

    This work explains the production, morphology, and features of novel nanocomposite (NC) established on poly(vinyl pyrrolidone) (PVP) as polymer background and modified alpha manganese dioxide (α-MnO 2 ) nanorod (NR) asan efficient filler. At first, one-dimensional α-MnO 2 nanorods (NRs) were produced by a hydrothermal technique and then they were amended with stearic acid (SA) by a solvothermal process. In following, the NCs were made by adding different volumes of α-MnO 2 -SA NR (1, 3 and 5wt%) in the PVP matrix through ultrasonic irradiation as a green, low-cost, fast, and useful technique. Structural and morphological descriptions confirm crystallinity of α-MnO 2 -SA NRs and showed that NRs have been separately dispersed in PVP matrix with rod-like morphology and diameter of about 40-60nm. The use of modifier and ultrasonic waves is accountable for good homogeneities of NRs. Thermogravimetric analysis revealed that thermal permanency of the obtained NCs has grown with increasing the α-MnO 2 -SA content. Also, the UV-vis absorption of NCs was enhanced with the incorporation of the modified α-MnO 2 NR in PVP matrix. The substantial perfections in NCs properties are associated to compatible intermolecular relations between the surface modifying groups of the α-MnO 2 -SA and PVP chain. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effects of poly(2-hydroxyethyl methacrylate) and poly(vinyl-pyrrolidone) hydrogel implants on myopic and normal chick sclera

    PubMed Central

    Su, James; Iomdina, Elena; Tarutta, Elena; Ward, Brian; Song, Jie; Wildsoet, Christine F.

    2008-01-01

    There has been generally little attention paid to the utilization of biomaterials as an anti-myopia treatment. The purpose of this study was to investigate whether polymeric hydrogels, either implanted or injected adjacent to the outer scleral surface, slow ocular elongation. White Leghorn (gallus gallus domesticus) chicks were used at 2 weeks of age. Chicks had either (1) strip of poly(2-hydroxyethyl methacrylate) (pHEMA) implanted monocularly against the outer sclera at the posterior pole, or (2) an in situ polymerizing gel [main ingredient: poly(vinyl-pyrrolidone) (PVP)] injected monocularly at the same location. Some of the eyes injected with the polymer were fitted with a diffuser or a −10D lens. In each experiment, ocular lengths were measured at regular intervals by high frequency A-scan ultrasonography, and chicks were sacrificed for histology at staged intervals. No in vivo signs of either orbital or ocular inflammation were observed. The pHEMA implant significantly increased scleral thickness by the third week, and the implant became encapsulated with fibrous tissue. The PVP-injected eyes left otherwise untreated, showed a significant increase in scleral thickness, due to increased chondrocyte proliferation and extracellular matrix deposition. However, there was no effect of the PVP injection on ocular elongation. In eyes wearing optical devices, there was no effect on either scleral thickness or ocular elongation. These results represent “proof of principle” that scleral growth can be manipulated without adverse inflammatory responses. However, since neither approach slowed ocular elongation, additional factors must influence scleral surface area expansion in the avian eye. PMID:19109950

  2. Quantification of six potential unspecific human biomarkers of 1-vinyl-2-pyrrolidone exposure in Sprague-Dawley rat urine using gas chromatography coupled with triple mass spectrometry.

    PubMed

    Bertram, J; Schettgen, T; Kraus, T

    2017-11-15

    The monomer 1-vinyl-2-pyrrolidone (VP) is a substance with excellent solvent features. It is used in a wide variety of pharmaceutical, cosmetic, food industrial or technical applications and produced on an industrial scale. Since VP has caused adenocarcinoma of the nasal cavity and liver cell carcinoma in long-term experiments with rats, a human biomarker would be appreciated for risk assessment. A sensitive analytical electron ionization gas chromatography/tandem mass spectrometry (GC/MS/MS) method for the determination of six possible biomarkers for VP in urine was established and validated. Two isotope-labeled internal standards (ISTD) were used for quantification. A simple and easy to use freeze-drying step was performed prior to derivatization with N-tert-butyldimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) and following sample extraction for cleanup purposes. A calibration curve with six calibration standards ranging from 50 μg/L to 2000 μg/L (10-fold higher for H-OPAA) in urine was prepared. Validation results were satisfactory with recoveries ranging from 88.2 to 110.2 % with two exceptions for the lowest quality control for two substances without ISTD (126.4 % and 139.3 %). Three of the substances could be identified as VP metabolites in an exposure study with Sprague-Dawley (SD) rats. A quick and easy to use method has been established for six target molecules investigated for a better understanding of the metabolism of VP. Two of three substances identified as metabolites of VP could serve as a nonspecific human biomarker for VP exposure as shown with an excerpt of an exposure study performed in SD rats. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, propylene glycol, N-methyl-2-pyrrolidone, and water at 25 degrees C.

    PubMed

    Jouyban, Abolghasem; Soltanpour, Shahla

    2010-09-01

    The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 degrees C are reported. The generated data are fitted to the Jouyban-Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

  4. Process for radiation grafting hydrogels onto organic polymeric substrates

    DOEpatents

    Ratner, Buddy D.; Hoffman, Allan S.

    1976-01-01

    An improved process for radiation grafting of hydrogels onto organic polymeric substrates is provided comprising the steps of incorporating an effective amount of cupric or ferric ions in an aqueous graft solution consisting of N-vinyl-2 - pyrrolidone or mixture of N-vinyl-2 - pyrrolidone and other monomers, e.g., 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, propylene glycol acrylate, acrylamide, methacrylic acid and methacrylamide, immersing an organic polymeric substrate in the aqueous graft solution and thereafter subjecting the contacted substrate with ionizing radiation.

  5. pH-responsive and enzymatically-responsive hydrogel microparticles for the oral delivery of therapeutic proteins: Effects of protein size, crosslinking density, and hydrogel degradation on protein delivery.

    PubMed

    Koetting, Michael Clinton; Guido, Joseph Frank; Gupta, Malvika; Zhang, Annie; Peppas, Nicholas A

    2016-01-10

    Two potential platform technologies for the oral delivery of protein therapeutics were synthesized and tested. pH-responsive poly(itaconic acid-co-N-vinyl-2-pyrrolidone) (P(IA-co-NVP)) hydrogel microparticles were tested in vitro with model proteins salmon calcitonin, urokinase, and rituximab to determine the effects of particle size, protein size, and crosslinking density on oral delivery capability. Particle size showed no significant effect on overall delivery potential but did improve percent release of encapsulated protein over the micro-scale particle size range studied. Protein size was shown to have a significant impact on the delivery capability of the P(IA-co-NVP) hydrogel. We show that when using P(IA-co-NVP) hydrogel microparticles with 3 mol% tetra(ethylene glycol) dimethacrylate crosslinker, a small polypeptide (salmon calcitonin) loads and releases up to 45 μg/mg hydrogel while the mid-sized protein urokinase and large monoclonal antibody rituximab load and release only 19 and 24 μg/mg hydrogel, respectively. We further demonstrate that crosslinking density offers a simple method for tuning hydrogel properties to variously sized proteins. Using 5 mol% TEGDMA crosslinker offers optimal performance for the small peptide, salmon calcitonin, whereas lower crosslinking density of 1 mol% offers optimal performance for the much larger protein rituximab. Finally, an enzymatically-degradable hydrogels of P(MAA-co-NVP) crosslinked with the peptide sequence MMRRRKK were synthesized and tested in simulated gastric and intestinal conditions. These hydrogels offer ideal loading and release behavior, showing no degradative release of encapsulated salmon calcitonin in gastric conditions while yielding rapid and complete release of encapsulated protein within 1h in intestinal conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Kinetics study of invertase covalently linked to a new functional nanogel.

    PubMed

    Raj, Lok; Chauhan, Ghanshyam S; Azmi, Wamik; Ahn, J-H; Manuel, James

    2011-02-01

    Nanogels are promising materials as supports for enzyme immobilization. A new hydrogel comprising of methacrylic acid (MAAc) and N-vinyl pyrrolidone (N-VP) and ethyleneglycol dimethacrylate (EGDMA) was synthesized and converted to nanogel by an emulsification method. Nanogel was further functionalized by Curtius azide reaction for use as support for the covalent immobilization of invertase (Saccharomyces cerevisiae). As-prepared or invertase-immobilized nanogel was characterized by FTIR, XRD, TEM and nitrogen analysis. The characterization of both free and the immobilized-invertase were performed using a spectrophotometric method at 540 nm. The values of V(max), maximum reaction rate, (0.123 unit/mg), k(m), Michaelis constant (7.429 mol/L) and E(a), energy of activation (3.511 kj/mol) for the immobilized-invertase are comparable with those of the free invertase at optimum conditions (time 70 min, pH 6.0 and temperature 45°C). The covalent immobilization enhanced the pH and thermal stability of invertase. The immobilized biocatalyst was efficiently reused up to eight cycles. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Mild copper-catalyzed vinylation reactions of azoles and phenols with vinyl bromides.

    PubMed

    Taillefer, Marc; Ouali, Armelle; Renard, Brice; Spindler, Jean-Francis

    2006-07-05

    An efficient and straightforward copper-catalyzed method allowing vinylation of N- or O-nucleophiles with di- or trisubstituted vinyl bromides is reported. The procedure is applicable to a broad range of substrates since N-vinylation of mono-, di-, and triazoles as well as O-vinylation of phenol derivatives can be performed with catalytic amounts of copper iodide and inexpensive nitrogen ligands 3 or 8. In the case of more hindered vinyl bromides, the use of the original bidentate chelator 8 was shown to be more efficient to promote the coupling reactions than our key tetradentate ligand 3. The corresponding N-(1-alkenyl)azoles and alkenyl aryl ethers are obtained in high yields and selectivities under very mild temperature conditions (35-110 degrees C for N-vinylation reactions and 50-80 degrees C for O-vinylation reactions). Moreover, to our knowledge, this method is the first example of a copper-catalyzed vinylation of various azoles. Finally, this protocol, practical on a laboratory scale and easily adaptable to an industrial scale, is very competitive compared to the existing methods that allow the synthesis of such compounds.

  8. Radiation graft modification of EPDM rubber

    NASA Astrophysics Data System (ADS)

    Katbab, A. A.; Burford, R. P.; Garnett, J. L.

    N-Vinyl pyrrolidone (NVP), 2-hydroxyethylmethacrylate (HEMA) and acrylamide (AAm) have been grafted to the surface of rubber vulcanizates based on ethylene-propylene-terpolymer (EPDM) using the simultaneous radiation method to alter surface properties such as wettability and therefore biocompatibility. The effect of monomer concentration, solvent and EPDM structural factors on the grafting behavior have been investigated. The inhibitory effect upon homopolymerization of various salts has also been evaluated for the three monomers. NVP and HEMA could be grafted onto EPDM rubber in the presence of aqueous solutions of cupric nitrate at 0.005 M and 1.0 M concentrations respectively. Aqueous solutions of Mohr's salt (ammonium ferrous sulphate) at 0.05 M not only suppressed the homopolymerization of AAm but also increased grafting yield. The percentage grafting also increased with increasing AAm concentration. A mechanism has been proposed to explain the behaviour of these monomers. The inclusion of multifunctional acrylates in additive amounts (1.0 vol%) enhanced the graft degree. Modified samples were able to be efficiently stained, allowing the depth of the graft copolymerization to be determined by light microscopy. Water was found to have an accelerating effect on the polymerization of these monomers, but methanol prevented their polymerization completely. The effect of EPDM structural factors upon degree of grafting was found to vary, depending upon the monomer type.

  9. Drug loading optimization and extended drug delivery of corticoids from pHEMA based soft contact lenses hydrogels via chemical and microstructural modifications.

    PubMed

    García-Millán, Eva; Koprivnik, Sandra; Otero-Espinar, Francisco Javier

    2015-06-20

    This paper proposes an approach to improve drug loading capacity and release properties of poly(2-hydroxyethyl methacrylate) (p(HEMA)) soft contact lenses based on the optimization of the hydrogel composition and microstructural modifications using water during the polymerization process. P(HEMA) based soft contact lenses were prepared by thermal or photopolymerization of 2-hydroxyethyl methacrylate (HEMA) solutions containing ethylene glycol di-methacrylate as crosslinker and different proportions of N-vinyl-2-pyrrolidone (NVP) or methacrylic acid (MA) as co-monomers. Transmittance, water uptake, swelling, microstructure, drug absorption isotherms and in vitro release were characterized using triamcinolone acetonide (TA) as model drug. Best drug loading ratios were obtained with lenses containing the highest amount (200 mM) of MA. Incorporation of 40% V/V of water during the polymerization increases the hydrogel porosity giving a better drug loading capacity. In vitro TA release kinetics shows that MA hydrogels released the drug significantly faster than NVP-hydrogels. Drug release was found to be diffusion controlled and kinetics was shown to be reproducible after consecutive drug loading/release processes. Results of p(HEMA) based soft contact lenses copolymerized with ethylene glycol dimethacrylate (EGDMA) and different co-monomers could be a good alternative to optimize the loading and ocular drug delivery of this corticosteroid drug. Copyright © 2015. Published by Elsevier B.V.

  10. NVP melt/magma viscosity: insight on Mercury lava flows

    NASA Astrophysics Data System (ADS)

    Rossi, Stefano; Morgavi, Daniele; Namur, Olivier; Vetere, Francesco; Perugini, Diego; Mancinelli, Paolo; Pauselli, Cristina

    2016-04-01

    After more than four years of orbiting Mercury, NASA's MESSENGER spacecraft came to an end in late April 2015. MESSENGER has provided many new and surprising results. This session will again highlight the latest results on Mercury based on MESSENGER observations or updated modelling. The session will further address instrument calibration and science performance both retrospective on MESSENGER and on the ESA/JAXA BepiColombo mission. Papers covering additional themes related to Mercury are also welcomed. Please be aware that this session will be held as a PICO session. This will allow an intensive exchange of expertise and experience between the individual instruments and mission. NVP melt/magma viscosity: insight on Mercury lava flows S. Rossi1, D. Morgavi1, O. Namur2, D. Perugini1, F.Vetere1, P. Mancinelli1 and C. Pauselli1 1 Dipartimento di Fisica e Geologia, Università di Perugia, piazza Università 1, 06123 Perugia, Italy 2 Uni Hannover Institut für Mineralogie, Leibniz Universität Hannover, Callinstraβe 3, 30167 Hannover, Germany In this contribution we report new measurements of viscosity of synthetic komatitic melts, used the behaviour of silicate melts erupted at the surface of Mercury. Composition of Mercurian surface magmas was calculated using the most recent maps produced from MESSENGER XRS data (Weider et al., 2015). We focused on the northern hemisphere (Northern Volcanic Province, NVP, the largest lava flow on Mercury and possibly in the Solar System) for which the spatial resolution of MESSENGER measurements is high and individual maps of Mg/Si, Ca/Si, Al/Si and S/Si were combined. The experimental starting material contains high Na2O content (≈7 wt.%) that strongly influences viscosity. High temperature viscosity measurements were carried out at 1 atm using a concentric cylinder apparatus equipped with an Anton Paar RheolabQC viscometer head at the Department of Physics and Geology (PVRG_lab) at the University of Perugia (Perugia, Italy

  11. Antithrombogenic and antibiotic composition and methods of preparation thereof

    DOEpatents

    Hermes, Robert E.

    1990-01-01

    Antithrombogenic and antibiotic composition of matter and method of preparation thereof. A random copolymer of a component of garlic and a biocompatible polymer has been prepared and found to exhibit antithrombogenic and antibiotic properties. Polymerization occurs selectively at the vinyl moiety in 2-vinyl-4H-1,3-dithiin when copolymerized with N-vinyl pyrrolidone.

  12. Design, Sustainable Synthesis, and Programmed Reactions of Templated N-Heteroaryl-Fused Vinyl Sultams.

    PubMed

    Laha, Joydev K; Sharma, Shubhra; Kirar, Seema; Banerjee, Uttam C

    2017-09-15

    A de novo design and synthesis of N-heteroaryl-fused vinyl sultams as templates for programming chemical reactions on vinyl sultam periphery or (hetero)aryl ring is described. The key features include rational designing and sustainable synthesis of the template, customized reactions of vinyl sultams at C═C bond or involving N-S bond cleavage, and reactions on the periphery of the heteroaryl ring for late-stage diversification. The simple, easy access to the template coupled with opportunities for the synthesis of diversely functionalized heterocyles from a single template constitutes a rare study in contemporary organic synthesis.

  13. Antithrombogenic and antibiotic composition and methods of preparation thereof

    DOEpatents

    Hermes, R.E.

    1990-04-17

    Antithrombogenic and antibiotic composition of matter and method of preparation are disclosed. A random copolymer of a component of garlic and a biocompatible polymer has been prepared and found to exhibit antithrombogenic and antibiotic properties. Polymerization occurs selectively at the vinyl moiety in 2-vinyl-4H-1,3-dithiin when copolymerized with N-vinyl pyrrolidone. 4 figs.

  14. Antithrombogenic and antibiotic compositions and methods of preparation thereof

    DOEpatents

    Hermes, R.E.

    1988-04-19

    Antithrombogenic and antibiotic composition of matter and method of preparation thereof. A random copolymer of a component of garlic and a biocompatible polymer has been prepared and found to exhibit antithrombogenic and antibiotic properties. Polymerization occurs selectively at the vinyl moiety in 2-vinyl-4H-1,3-dithiin when copolymerized with N-vinyl pyrrolidone. 4 figs., 2 tabs.

  15. [Monograph for N-Methyl-pyrrolidone (NMP) and human biomonitoring values for the metabolites 5-Hydroxy-NMP and 2-Hydroxy-N-methylsuccinimide].

    PubMed

    2015-10-01

    1-Methyl-pyrrolidone (NMP) is used as a solvent in many technical applications. The general population may be exposed to NMP from the use as ingredient in paint and graffiti remover, indoors also from use in paints and carpeting. Because of developmental toxic effects, the use of NMP in consumer products in the EU is regulated. The developmental effects accompanied by weak maternally toxic effects in animal experiments are considered as the critical effects by the German HBM Commission. Based on these effects, HBM-I values of 10 mg/l urine for children and of 15 mg/l for adults, respectively, were derived for the metabolites 5-Hydroxy-NMP and 2-Hydroxy-N-methylsuccinimide. HBM-II-values were set to 30 mg/l urine for children and 50 mg/l for adults, respectively. Because of similar effects of the structural analogue 1-ethyl-2-pyrrolidone (NEP), the possible mixed exposure to both compounds has to be taken into account when evaluating the total burden.

  16. Disk diffusion quality control guidelines for NVP-PDF 713: a novel peptide deformylase inhibitor.

    PubMed

    Anderegg, Tamara R; Jones, Ronald N

    2004-01-01

    NVP-PDF713 is a peptide deformylase inhibitor that has emerged as a candidate for treating Gram-positive infections and selected Gram-negative species that commonly cause community-acquired respiratory tract infections. This report summarizes the results of a multi-center (seven participants) disk diffusion quality control (QC) investigation for NVP PDF-713 using guidelines of the National Committee for Clinical Laboratory Standards and the standardized disk diffusion method. A total of 420 NVP-PDF 713 zone diameter values were generated for each QC organism. The proposed zone diameter ranges contained 97.6-99.8% of the reported participant results and were: Staphylococcus aureus ATCC 25923 (25-35 mm), Streptococcus pneumoniae ATCC 49619 (30-37 mm), and Haemophilus influenzae ATCC 49247 (24-32 mm). These QC criteria for the disk diffusion method should be applied during the NVP-PDF 713 clinical trials to maximize test accuracy.

  17. Biomonitoring of exposure to N-methyl-2-pyrrolidone in workers of the automobile industry.

    PubMed

    Meier, Swetlana; Schindler, Birgit K; Koslitz, Stephan; Koch, Holger M; Weiss, Tobias; Käfferlein, Heiko U; Brüning, Thomas

    2013-07-01

    N-methyl-2-pyrrolidone (NMP) is an important organic solvent for varnishes in industry. NMP has been previously shown to be a developmental toxicant in rodents. This study reports current exposures to NMP in the spraying department of an automobile plant using biological monitoring. Two specific metabolites, 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methyl-succinimide (2-HMSI), were analyzed in 69 urine samples of 14 workers exposed to NMP and 9 nonexposed controls. Three different working tasks ('loading' and 'cleaning' of the sprayer system and 'wiping/packing' of the sprayed materials) and three sampling times (preshift, postshift, and preshift of the following day) were studied in exposed workers. Median exposures of 5-HNMP and 2-HMSI in postshift urine of exposed workers were 0.91 and 0.52mg g(-1) creatinine, respectively, whereas median levels in controls were below the limit of detection. Decreased levels of 5-HNMP were observed in preshift urine samples on the following day (0.39mg g(-1) creatinine) in exposed workers, while the concentration of 2-HMSI did not change (0.49mg g(-1) creatinine). Highest exposures occurred during sprayer cleaning with a maximum level of 8.31mg g(-1) creatinine of 5-HNMP in postshift urine. In contrast to 'wipers/packers', no decrease in 5-HNMP could be observed in preshift urine samples on day 2 of the 'loaders' and 'cleaners'. Overall, exposure in terms of 5-HNMP postshift and 2-HMSI preshift of the following day were well below the current biological limit values of the European Union (70 and 20mg g(-1) creatinine). Our results provide initial data on NMP exposure in the automobile industry and suggest that the analysis of 5-HNMP in preshift samples also provides essential information, particularly in situations involving direct handling of liquid NMP-containing formulations.

  18. SPE-GC/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine.

    PubMed

    Kubota, Ryuichi; Endo, Yoko; Takeuchi, Akito; Inoue, Yoshinori; Ogata, Hiroko; Ogawa, Masanori; Nakagawa, Tomoo; Onda, Nobuhiko; Endo, Ginji

    2007-07-01

    An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant was injected into the capillary GC using a DB1701. This method allowed efficient separation of NMP, MSI, and 2-HMSI, which were nearly free of interference by other GC peaks arising from urine. Recoveries of NMP, MSI, and 2-HMSI from the SPE cartridge were about 98, 101, and 67%, respectively, with limits of detection of 0.04, 0.02, and 0.06 mg/L, respectively, which met the regulatory requirements. The present method was used for assay in biological monitoring of workers exposed to NMP in their occupational environment.

  19. The novel HSP90 inhibitor NVP-AUY922 shows synergistic anti-leukemic activity with cytarabine in vivo.

    PubMed

    Wendel, Torunn; Zhen, Yan; Suo, Zenhe; Bruheim, Skjalg; Wiedlocha, Antoni

    2016-01-15

    HSP90 is a molecular chaperone essential for stability, activity and intracellular sorting of many proteins, including oncoproteins, such as tyrosine kinases, transcription factors and cell cycle regulatory proteins. Therefore, inhibitors of HSP90 are being investigated for their potential as anti-cancer drugs. Here we show that the HSP90 inhibitor NVP-AUY922 induced degradation of the fusion oncoprotein FOP2-FGFR1 in a human acute myeloid leukemia (AML) cell line, KG-1a. Concordantly, downstream signaling cascades, such as STAT1, STAT3 and PLCγ were abrogated. At concentrations that caused FOP2-FGFR1 degradation and signaling abrogation, NVP-AUY922 treatment caused significant cell death and inhibition of proliferation of KG-1a cells in vitro. In an animal model for AML, NVP-AUY922 administrated alone showed no anti-leukemic activity. However, when NVP-AUY922 was administered in combination with cytarabine, the two compounds showed significant synergistic anti-leukemic activity in vivo. Thus NVP-AUY922 and cytarabine combination therapy might be a prospective strategy for AML treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Direct determination of N-methyl-2-pyrrolidone metabolites in urine by HPLC-electrospray ionization-MS/MS using deuterium-labeled compounds as internal standard.

    PubMed

    Suzuki, Yoshihiro; Endo, Yoko; Ogawa, Masanori; Yamamoto, Shinobu; Takeuchi, Akito; Nakagawa, Tomoo; Onda, Nobuhiko

    2009-11-01

    N-methyl-2-pyrrolidone (NMP) has been used in many industries and biological monitoring of NMP exposure is preferred to atmospheric monitoring in occupational health. We developed an analytical method that did not include solid phase extraction (SPE) but utilized deuterium-labeled compounds as internal standard for high-performance liquid chromatography-electrospray ionization-mass spectrometry using a C30 column. Urinary concentrations of NMP and its known metabolites 5-hydoxy-N-methyl-2-pyrrolidone (5-HNMP), N-methyl-succinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) were determined in a single run. The method provided baseline separation of these compounds. Their limits of detection in 10-fold diluted urine were 0.0001, 0.006, 0.008, and 0.03 mg/L, respectively. Linear calibration covered a biological exposure index (BEI) for urinary concentration. The within-run and total precisions (CV, %) were 5.6% and 9.2% for NMP, 3.4% and 4.2% for 5-HNMP, 3.7% and 6.0% for MSI, and 6.5% and 6.9% for 2-HMSI. The method was evaluated using international external quality assessment samples, and urine samples from workers exposed to NMP in an occupational area.

  1. Determination of 5-hydroxy-N-methyl-2-pyrrolidone and 2-hydroxy-N-methylsuccinimide in human plasma and urine using liquid chromatography-electrospray tandem mass spectrometry.

    PubMed

    Carnerup, M A; Akesson, B; Jönsson, B A

    2001-09-15

    A method for simultaneous determination of 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI) was developed. These compounds are metabolites from N-methyl-2-pyrrolidone (NMP), a powerful and widely used organic solvent. 5-HNMP and 2-HMSI were purified from plasma and urine by solid-phase extraction using Isolute ENV+ columns, and analysed by liquid chromatography coupled to a mass spectrometer fitted with an atmospheric pressure turbo ion spray ionisation interface in the positive ion mode. The method was validated for plasma and urine concentrations from 0.12 to 25 microg/ml. The recoveries for 5-HNMP and 2-HMSI in plasma were 99 and 98%, respectively, and in urine 111 and 106%, respectively. For 5-HNMP and 2-HMSI, the within-day precision in plasma was 1-4 and 3-6%, respectively, and in urine 2-12 and 3-10%, respectively. The corresponding data for the between-day precision was 5 and 3-6%, respectively, and 4-6 and 7-8%, respectively. The detection limit for 5-HNMP was 4 ng/ml in plasma and 120 ng/ml in urine. For 2-HMSI, it was 5 ng/ml in plasma and 85 ng/ml in urine. The method is applicable for analysis of plasma and urine samples from workers exposed to NMP.

  2. Tyrosine kinase inhibitor NVP-BGJ398 functionally improves FGFR3-related dwarfism in mouse model.

    PubMed

    Komla-Ebri, Davide; Dambroise, Emilie; Kramer, Ina; Benoist-Lasselin, Catherine; Kaci, Nabil; Le Gall, Cindy; Martin, Ludovic; Busca, Patricia; Barbault, Florent; Graus-Porta, Diana; Munnich, Arnold; Kneissel, Michaela; Di Rocco, Federico; Biosse-Duplan, Martin; Legeai-Mallet, Laurence

    2016-05-02

    Achondroplasia (ACH) is the most frequent form of dwarfism and is caused by gain-of-function mutations in the fibroblast growth factor receptor 3-encoding (FGFR3-encoding) gene. Although potential therapeutic strategies for ACH, which aim to reduce excessive FGFR3 activation, have emerged over many years, the use of tyrosine kinase inhibitor (TKI) to counteract FGFR3 hyperactivity has yet to be evaluated. Here, we have reported that the pan-FGFR TKI, NVP-BGJ398, reduces FGFR3 phosphorylation and corrects the abnormal femoral growth plate and calvaria in organ cultures from embryos of the Fgfr3Y367C/+ mouse model of ACH. Moreover, we demonstrated that a low dose of NVP-BGJ398, injected subcutaneously, was able to penetrate into the growth plate of Fgfr3Y367C/+ mice and modify its organization. Improvements to the axial and appendicular skeletons were noticeable after 10 days of treatment and were more extensive after 15 days of treatment that started from postnatal day 1. Low-dose NVP-BGJ398 treatment reduced intervertebral disc defects of lumbar vertebrae, loss of synchondroses, and foramen-magnum shape anomalies. NVP-BGJ398 inhibited FGFR3 downstream signaling pathways, including MAPK, SOX9, STAT1, and PLCγ, in the growth plates of Fgfr3Y367C/+ mice and in cultured chondrocyte models of ACH. Together, our data demonstrate that NVP-BGJ398 corrects pathological hallmarks of ACH and support TKIs as a potential therapeutic approach for ACH.

  3. Dermal absorption and urinary elimination of N-methyl-2-pyrrolidone.

    PubMed

    Bader, Michael; Keener, Stephen A; Wrbitzky, Renate

    2005-09-01

    The dermal absorption of the solvent N-methyl-2-pyrrolidone (NMP) and its elimination in urine was investigated in an experimental study. Seven volunteers were exposed to 1045 mg of liquid NMP under occlusive conditions for 2 h. Urine was collected before, during and up to 72 h after the exposure and analysed for NMP by GC/MS after liquid-liquid extraction. Additionally, the remaining NMP in the pads was determined to estimate the total dermal uptake. The concentration of NMP in urine increased rapidly after beginning of the exposure up to 1 h after the exposure was completed. A peak concentration of 1,836+/-863 microg/l was observed, the half-life in urine was 3.2 h. About 0.5% of the absorbed dose was excreted metabolically unchanged. An average dermal absorption of 5.5 mg cm(-2) h(-1) was calculated. The results of this study show that the percutaneous absorption of NMP may contribute significantly to the overall uptake of the solvent, e.g. in the workplace. Therefore, a biological monitoring of NMP exposed workers is essential for occupational-medical surveillance.

  4. Metabolic engineering of Escherichia coli for the biosynthesis of 2-pyrrolidone

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

    Zhang, Jingwei; Kao, Emily; Wang, George

    2-Pyrrolidone is a valuable bulk chemical with myriad applications as a solvent, polymer precursor and active pharmaceutical intermediate. A novel 2-pyrrolidone synthase, ORF27, from Streptomyces aizunensis was identified to catalyze the ring closing dehydration of γ-aminobutyrate. ORF27's tendency to aggregate was resolved by expression at low temperature and fusion to the maltose binding protein (MBP). Recombinant Escherichia coli was metabolically engineered for the production of 2-pyrrolidone from glutamate by expressing both the genes encoding GadB, a glutamate decarboxylase, and ORF27. Incorporation of a GadB mutant lacking H465 and T466, GadB_δHT, improved the efficiency of one-pot 2-pyrrolidone biosynthesis in vivo. Whenmore » the recombinant E. coli strain expressing the E. coli GadB_δHT mutant and the ORF27-MBP fusion was cultured in ZYM-5052 medium containing 9. g/L of l-glutamate, 7.7. g/L of l-glutamate was converted to 1.1. g/L of 2-pyrrolidone within 31. h, achieving 25% molar yield from the consumed substrate.« less

  5. Metabolic engineering of Escherichia coli for the biosynthesis of 2-pyrrolidone

    DOE PAGES

    Zhang, Jingwei; Kao, Emily; Wang, George; ...

    2016-12-01

    2-Pyrrolidone is a valuable bulk chemical with myriad applications as a solvent, polymer precursor and active pharmaceutical intermediate. A novel 2-pyrrolidone synthase, ORF27, from Streptomyces aizunensis was identified to catalyze the ring closing dehydration of γ-aminobutyrate. ORF27's tendency to aggregate was resolved by expression at low temperature and fusion to the maltose binding protein (MBP). Recombinant Escherichia coli was metabolically engineered for the production of 2-pyrrolidone from glutamate by expressing both the genes encoding GadB, a glutamate decarboxylase, and ORF27. Incorporation of a GadB mutant lacking H465 and T466, GadB_δHT, improved the efficiency of one-pot 2-pyrrolidone biosynthesis in vivo. Whenmore » the recombinant E. coli strain expressing the E. coli GadB_δHT mutant and the ORF27-MBP fusion was cultured in ZYM-5052 medium containing 9. g/L of l-glutamate, 7.7. g/L of l-glutamate was converted to 1.1. g/L of 2-pyrrolidone within 31. h, achieving 25% molar yield from the consumed substrate.« less

  6. Tyrosine kinase inhibitor NVP-BGJ398 functionally improves FGFR3-related dwarfism in mouse model

    PubMed Central

    Dambroise, Emilie; Kramer, Ina; Benoist-Lasselin, Catherine; Kaci, Nabil; Le Gall, Cindy; Martin, Ludovic; Busca, Patricia; Barbault, Florent; Graus-Porta, Diana; Munnich, Arnold; Kneissel, Michaela; Di Rocco, Federico; Biosse-Duplan, Martin

    2016-01-01

    Achondroplasia (ACH) is the most frequent form of dwarfism and is caused by gain-of-function mutations in the fibroblast growth factor receptor 3–encoding (FGFR3-encoding) gene. Although potential therapeutic strategies for ACH, which aim to reduce excessive FGFR3 activation, have emerged over many years, the use of tyrosine kinase inhibitor (TKI) to counteract FGFR3 hyperactivity has yet to be evaluated. Here, we have reported that the pan-FGFR TKI, NVP-BGJ398, reduces FGFR3 phosphorylation and corrects the abnormal femoral growth plate and calvaria in organ cultures from embryos of the Fgfr3Y367C/+ mouse model of ACH. Moreover, we demonstrated that a low dose of NVP-BGJ398, injected subcutaneously, was able to penetrate into the growth plate of Fgfr3Y367C/+ mice and modify its organization. Improvements to the axial and appendicular skeletons were noticeable after 10 days of treatment and were more extensive after 15 days of treatment that started from postnatal day 1. Low-dose NVP-BGJ398 treatment reduced intervertebral disc defects of lumbar vertebrae, loss of synchondroses, and foramen-magnum shape anomalies. NVP-BGJ398 inhibited FGFR3 downstream signaling pathways, including MAPK, SOX9, STAT1, and PLCγ, in the growth plates of Fgfr3Y367C/+ mice and in cultured chondrocyte models of ACH. Together, our data demonstrate that NVP-BGJ398 corrects pathological hallmarks of ACH and support TKIs as a potential therapeutic approach for ACH. PMID:27064282

  7. Biocatalytic Asymmetric Synthesis of (1R, 2S)-N-Boc-vinyl-ACCA Ethyl Ester with a Newly Isolated Sphingomonas aquatilis.

    PubMed

    Zhu, Shaozhou; Shi, Ying; Zhang, Xinyu; Zheng, Guojun

    2018-02-01

    1-amino cyclopropane-1-carboxylic acid (ACCA) and its derivatives are essential pharmacophoric unit that widely used in drug research and development. Specifically, (1R, 2S)-N-Boc-vinyl-ACCA ethyl ester (vinyl-ACCA) is a key chiral intermediate in the synthesis of highly potent hepatitis C virus (HCV) NS3/4A protease inhibitors such as asunaprevir and simeprevir. Developing strategies for the asymmetric synthesis of vinyl-ACCA is thus extremely high demand. In this study, 378 bacterial strains were isolated from soil samples using N-Boc-vinyl-ACCA ethyl ester as the sole carbon source and were screened for esterase activity. Fourteen of which worked effectively for the asymmetric synthesis of (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester. The strain CY-2, identified as Sphingomonas aquatilis, which showed the highest stability and enantioselectivity was selected as whole cell biocatalyst for further study. A systematic study of all factors influencing the enzymatic hydrolysis was performed. Under optimized conditions, resolution of rac-vinyl-ACCA to (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester with 88.2% ee and 62.4% conversion (E = 9) was achieved. Besides, S. aquatilis was also used to transform other 10 different substrates. Notably, it was found that 7 of them could be stereoselectively hydrolyzed, especially for (1R,2S)-1-amino-vinyl-ACCA ethyl ester hydrochloride (99.6% ee, E>200). Our investigations provide a new efficient whole cell biocatalyst for resolution of ACCA and might be developed for industry application.

  8. NVP-QBE170: an inhaled blocker of the epithelial sodium channel with a reduced potential to induce hyperkalaemia

    PubMed Central

    Coote, K J; Paisley, D; Czarnecki, S; Tweed, M; Watson, H; Young, A; Sugar, R; Vyas, M; Smith, N J; Baettig, U; Groot-Kormelink, P J; Gosling, M; Lock, R; Ethell, B; Williams, G; Schumacher, A; Harris, J; Abraham, W M; Sabater, J; Poll, C T; Faller, T; Collingwood, S P; Danahay, H

    2015-01-01

    Background and Purpose Inhaled amiloride, a blocker of the epithelial sodium channel (ENaC), enhances mucociliary clearance (MCC) in cystic fibrosis (CF) patients. However, the dose of amiloride is limited by the mechanism-based side effect of hyperkalaemia resulting from renal ENaC blockade. Inhaled ENaC blockers with a reduced potential to induce hyperkalaemia provide a therapeutic strategy to improve mucosal hydration and MCC in the lungs of CF patients. The present study describes the preclinical profile of a novel ENaC blocker, NVP-QBE170, designed for inhaled delivery, with a reduced potential to induce hyperkalaemia. Experimental Approach The in vitro potency and duration of action of NVP-QBE170 were compared with amiloride and a newer ENaC blocker, P552-02, in primary human bronchial epithelial cells (HBECs) by short-circuit current. In vivo efficacy and safety were assessed in guinea pig (tracheal potential difference/hyperkalaemia), rat (hyperkalaemia) and sheep (MCC). Key Results In vitro, NVP-QBE170 potently inhibited ENaC function in HBEC and showed a longer duration of action to comparator molecules. In vivo, intratracheal (i.t.) instillation of NVP-QBE170 attenuated ENaC activity in the guinea pig airways with greater potency and duration of action than that of amiloride without inducing hyperkalaemia in either guinea pig or rat. Dry powder inhalation of NVP-QBE170 by conscious sheep increased MCC and was better than inhaled hypertonic saline in terms of efficacy and duration of action. Conclusions and Implications NVP-QBE170 highlights the potential for inhaled ENaC blockers to exhibit efficacy in the airways with a reduced risk of hyperkalaemia, relative to existing compounds. PMID:25573195

  9. NVP-QBE170: an inhaled blocker of the epithelial sodium channel with a reduced potential to induce hyperkalaemia.

    PubMed

    Coote, K J; Paisley, D; Czarnecki, S; Tweed, M; Watson, H; Young, A; Sugar, R; Vyas, M; Smith, N J; Baettig, U; Groot-Kormelink, P J; Gosling, M; Lock, R; Ethell, B; Williams, G; Schumacher, A; Harris, J; Abraham, W M; Sabater, J; Poll, C T; Faller, T; Collingwood, S P; Danahay, H

    2015-06-01

    Inhaled amiloride, a blocker of the epithelial sodium channel (ENaC), enhances mucociliary clearance (MCC) in cystic fibrosis (CF) patients. However, the dose of amiloride is limited by the mechanism-based side effect of hyperkalaemia resulting from renal ENaC blockade. Inhaled ENaC blockers with a reduced potential to induce hyperkalaemia provide a therapeutic strategy to improve mucosal hydration and MCC in the lungs of CF patients. The present study describes the preclinical profile of a novel ENaC blocker, NVP-QBE170, designed for inhaled delivery, with a reduced potential to induce hyperkalaemia. The in vitro potency and duration of action of NVP-QBE170 were compared with amiloride and a newer ENaC blocker, P552-02, in primary human bronchial epithelial cells (HBECs) by short-circuit current. In vivo efficacy and safety were assessed in guinea pig (tracheal potential difference/hyperkalaemia), rat (hyperkalaemia) and sheep (MCC). In vitro, NVP-QBE170 potently inhibited ENaC function in HBEC and showed a longer duration of action to comparator molecules. In vivo, intratracheal (i.t.) instillation of NVP-QBE170 attenuated ENaC activity in the guinea pig airways with greater potency and duration of action than that of amiloride without inducing hyperkalaemia in either guinea pig or rat. Dry powder inhalation of NVP-QBE170 by conscious sheep increased MCC and was better than inhaled hypertonic saline in terms of efficacy and duration of action. NVP-QBE170 highlights the potential for inhaled ENaC blockers to exhibit efficacy in the airways with a reduced risk of hyperkalaemia, relative to existing compounds. © 2015 The British Pharmacological Society.

  10. [Correlations of pharmacokinetics and pharmacodynamics of a combined preparation containing pyrrolidone and pyroglutamic acid].

    PubMed

    Sariev, A K; Lun'shina, E V; Zherdev, V P; Mirzoian, N R

    2006-01-01

    Experiments showed that a new drug composition containing pyrrolidone and pyroglutamic acid exhibits a significant cerebrovascular effect upon peroral administration in rats. The pharmacokinetics of pyrrolidone monitored upon its combined administration with pyroglutamic acid shows that this drug, as a component of the composition, is characterized by a high absolute bioavailability and permeability trough the blood-brain barrier. The presence of pyroglutamic acid slows down the absorption and elimination of pyrrolidone and enhances its distribution in the organs and tissues. There is a correlation between the concentration of pyrrolidone in the brain, on the one hand, and the levels of cerebral microcirculation and arterial pressure on the other hand. An increase in the concentration of pyrrolidone in the brain is accompanied by more intensive cerebral blood flow and by a decrease in the arterial pressure.

  11. Safety and Efficacy of HIV Hyperimmune Globulin (HIVIGLOB) for Prevention of Mother-to-Child HIV Transmission in HIV-1 infected Pregnant Women and their Infants in Kampala, Uganda (HIVIGLOB/NVP STUDY)

    PubMed Central

    Onyango-Makumbi, Carolyne; Omer, Saad B.; Mubiru, Michael; Moulton, Lawrence H.; Nakabiito, Clemensia; Musoke, Philippa; Mmiro, Francis; Zwerski, Sheryl; Wigzell, Hans; Falksveden, Lars; Wahren, Britta; Antelman, Gretchen; Fowler, Mary Glenn; Guay, Laura; Jackson, J. Brooks

    2011-01-01

    Background This phase III randomized clinical trial compared single dose nevirapine (sdNVP) plus HIV immunoglobulin (HIVIGLOB) to sdNVP alone for preventing maternal-to-child transmission (PMTCT) of HIV. Primary objectives were to determine rates of HIV infection among infants, and to assess the safety of HIVIGLOB in combination with sdNVP in HIV-infected Ugandan pregnant women and their infants. Methods Mother-infant pairs were randomized to receive 200mg of NVP to women in labor and 2mg/kg NVP to newborns within 72 hours after birth (sdNVP arm) or to receive sdNVP plus a single intravenous 240ml dose of HIVIGLOB given to women at 36-38 weeks gestation and a single intravenous 24ml dose to newborns within 18 hours of birth (HIVIGLOB/sdNVP arm). Risk of HIV infection was determined using Kaplan-Meier and risk ratio estimates at birth, 2, 6, 14 weeks, 6 and 12 months of age. Results Intent-to-treat analysis included 198 HIVIGLOB/sdNVP and 294 sdNVP mother-infant pairs. At 6 months of age, the primary endpoint, there was no statistically significant difference in HIV transmission in the HIVIGLOB/sdNVP arm versus the sdNVP arm (18.7% vs.15.0%; RR =1.240 [95% CI: 0.833-1.846]; p= 0.290). Similarly, the proportion of serious adverse events in the HIVIGLOB/sdNVP and sdNVP arms, respectively for mothers (18.9% vs. 19.3%; p= 0.91) and infants (62.6% vs. 59.5%; p=0.51), were not significantly different. Conclusion Giving mother-infant pairs an infusion of peripartum HIV hyperimmunoglobulin in addition to sdNVP for PMTCT was as safe as sdNVP alone, but was no more effective than sdNVP alone in preventing HIV transmission. PMID:21826009

  12. Enhanced photodynamic activity of hypericin by penetration enhancer N-methyl pyrrolidone formulations in the chick chorioallantoic membrane model.

    PubMed

    Saw, Constance Lay Lay; Heng, Paul Wan Sia; Chin, William Wei Lim; Soo, Khee Chee; Olivo, Malini

    2006-07-08

    Hypericin (HY) was examined for photodynamic therapy (PDT)-induced vascular damage using the chick chorioallantoic membrane (CAM) model. Clinically, plasma protein was used to solubilize HY. Upon binding to albumin, free HY available to be transported through the membrane may be limited. Hence, formulations containing a biocompatible solvent, N-Methyl pyrrolidone (NMP), have the potential to enhance HY delivery into solid tumors. At suitable concentrations, NMP and/or light irradiation did not produce antivascular damage. Hypericin-PDT effects showed to be HY and NMP concentrations-dependent. These findings indicate that NMP is a promising solvent and penetration enhancer for HY-PDT clinical applications.

  13. Effects of pore forming agents on chitosan-graft-poly(N-vinylpyrrolidone) hydrogel properties for use as a matrix for floating drug delivery

    NASA Astrophysics Data System (ADS)

    Budianto, E.; Al-Shidqi, M. F.; Cahyana, A. H.

    2017-07-01

    Eradicating H. pylori-based infection by using conventional oral dosage form of amoxicillin trihydrate finds difficulties to overcome rapid gastric retention time. Encapsulating amoxicillin trihydrate in floating drug delivery system may solve the problem. In this research, the floating drug delivery system of amoxicillin trihydrate encapsulated in floating chitosan-graft-poly(N-vinyl pyrrolidone) hydrogels containing CaCO3 and NaHCO3 as pore forming agents has been successfully prepared. Pore forming agents used was varied with the ratio of 10 to 25% pore forming agents to total mass of the used materials. The hydrogel were characterizedusing FTIR spectrophotometer and stereo microscope. As pore forming agents compositions increased, the porosity (%) and floating properties increased but followed by decrease in drug entrapment efficiency. Most of the floating hydrogels possessed floating ability longer than 180 min and the highest porosity was found in hydrogel containing 25% NaHCO3. Hydrogel containing CaCO3 showed sustained drug release profile than hydrogel containing NaHCO3. However, the optimum formulation was achieved at composition of 10% NaHCO3 with 57% of drug entrapped within the hydrogel and 43% drug released. The results of these studies show that NaHCO3 is an effective pore forming agents for chitosan-graft-poly(N-vinyl pyrrolidone) hydrogel preparation as compare to CaCO3.

  14. Tensile Properties of Poly (N-vinyl caprolactam) Gels

    NASA Technical Reports Server (NTRS)

    Morgret, Leslie D.; Hinkley, Jeffrey A.

    2004-01-01

    N-vinyl caprolactam was copolymerized with ethylene glycol dimethacrylate using a free-radical initiator in alcohol/water solution. The resulting gels were thermally-responsive in water, undergoing an approximate fivefold reversible volume shrinkage between room temperature and ca. 50 C. Tensile testing showed that the stress-strain behavior was qualitatively different in the collapsed state above the temperature-induced transition. At the higher temperature, gels were stiffer, more ductile, and showed greater time dependence. Implications for the design of gel actuators are briefly discussed.

  15. In Vitro Cytocompatibility of One- and Two-Dimensional Nanostructure-Reinforced Biodegradable Polymeric Nanocomposites

    PubMed Central

    Farshid, Behzad; Lalwani, Gaurav; Sitharaman, Balaji

    2015-01-01

    This study investigates the in vitro cytocompatibility of one- and two-dimensional (1-D and 2-D) carbon and inorganic nanomaterial reinforced polymeric nanocomposites fabricated using biodegradable polymer poly (propylene fumarate), crosslinking agent N-vinyl pyrrolidone (NVP) and following nanomaterials: single- and multi- walled carbon nanotubes, single- and multi- walled graphene oxide nanoribbons, graphene oxide nanoplatelets, molybdenum disulfide nanoplatelets, or tungsten disulfide nanotubes dispersed between 0.02–0.2 wt% concentrations in the polymer. The extraction media of unreacted components, crosslinked nanocomposites and their degradation products between 1X-100X dilutions were examined for effects on viability and attachment employing two cell lines: NIH3T3 fibroblasts and MC3T3 pre-osteoblasts. The extraction media of unreacted PPF/NVP elicited acute dose-dependent cytotoxicity attributed to leaching of unreacted components into cell culture media. However, extraction media of crosslinked nanocomposites showed no dose dependent adverse effects. Further, all crosslinked nanocomposites showed high viability (78–100%), high cellular attachment (40–55%), and spreading that was confirmed by confocal and scanning electron microscopy. Degradation products of nanocomposites showed a mild dose-dependent cytotoxicity possibly due to acidic degradation components of PPF. In general, compared to PPF control, none of the nanocomposites showed significant differences in cellular response to the unreacted components, crosslinked nanocomposites and their degradation products. The initial minor cytotoxic response and lower cell attachment numbers were observed only for a few nanocomposite groups; these effects were absent at later time points for all PPF nanocomposites. The favorable cytocompatibility results for all the nanocomposites opens avenues for in vivo safety and efficacy studies for bone tissue engineering applications. PMID:25367032

  16. Antimicrobial activity of LBM415 (NVP PDF-713) tested against pathogenic Neisseria spp. (Neisseria gonorrhoeae and Neisseria meningitidis).

    PubMed

    Jones, Ronald N; Sader, Helio S; Fritsche, Thomas R

    2005-02-01

    LBM415 (NVP PDF-713), a novel peptide deformylase inhibitor, was tested by reference methods against 2 collections of pathogenic Neisseria, N. gonorrhoeae (157 strains) and N. meningitidis (100 strains). The collection included strains resistant to penicillin, tetracycline, and fluoroquinolones and were also tested against ceftriaxone, ciprofloxacin, penicillin, and tetracycline. The 50% and 90% minimum inhibitory concentration values for LBM415 were 1 and 2 microg/mL, and 4 and 8 microg/mL for N. meningitidis and N. gonorrhoeae, respectively. All comparison agents were more active than this peptide deformylase inhibitor against this genus.

  17. Genotype-Dependent Efficacy of a Dual PI3K/mTOR Inhibitor, NVP-BEZ235, and an mTOR Inhibitor, RAD001, in Endometrial Carcinomas

    PubMed Central

    Shoji, Keiko; Oda, Katsutoshi; Kashiyama, Tomoko; Ikeda, Yuji; Nakagawa, Shunsuke; Sone, Kenbun; Miyamoto, Yuichiro; Hiraike, Haruko; Tanikawa, Michihiro; Miyasaka, Aki; Koso, Takahiro; Matsumoto, Yoko; Wada-Hiraike, Osamu; Kawana, Kei; Kuramoto, Hiroyuki; McCormick, Frank; Aburatani, Hiroyuki; Yano, Tetsu; Kozuma, Shiro; Taketani, Yuji

    2012-01-01

    The PI3K (phosphatidylinositol-3-kinase)/mTOR (mammalian target of rapamycin) pathway is frequently activated in endometrial cancer through various PI3K/AKT-activating genetic alterations. We examined the antitumor effect of NVP-BEZ235—a dual PI3K/mTOR inhibitor—and RAD001—an mTOR inhibitor—in 13 endometrial cancer cell lines, all of which possess one or more alterations in PTEN, PIK3CA, and K-Ras. We also combined these compounds with a MAPK pathway inhibitor (PD98059 or UO126) in cell lines with K-Ras alterations (mutations or amplification). PTEN mutant cell lines without K-Ras alterations (n = 9) were more sensitive to both RAD001 and NVP-BEZ235 than were cell lines with K-Ras alterations (n = 4). Dose-dependent growth suppression was more drastically induced by NVP-BEZ235 than by RAD001 in the sensitive cell lines. G1 arrest was induced by NVP-BEZ235 in a dose-dependent manner. We observed in vivo antitumor activity of both RAD001 and NVP-BEZ235 in nude mice. The presence of a MEK inhibitor, PD98059 or UO126, sensitized the K-Ras mutant cells to NVP-BEZ235. Robust growth suppression by NVP-BEZ235 suggests that a dual PI3K/mTOR inhibitor is a promising therapeutic for endometrial carcinomas. Our data suggest that mutational statuses of PTEN and K-Ras might be useful predictors of sensitivity to NVP-BEZ235 in certain endometrial carcinomas. PMID:22662154

  18. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2...

  19. Embryotoxic potential of N-methyl-pyrrolidone (NMP) and three of its metabolites using the rat whole embryo culture system

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

    Flick, Burkhard; Talsness, Chris E.; Jaeckh, Rudolf

    2009-06-01

    N-methyl-2-pyrrolidone (NMP), which undergoes extensive biotransformation, has been shown in vivo to cause developmental toxicity and, especially after oral treatment, malformations in rats and rabbits. Data are lacking as to whether the original compound or one of its main metabolites is responsible for the toxic effects observed. Therefore, the relative embryotoxicity of the parent compound and its metabolites was evaluated using rat whole embryo culture (WEC) and the balb/c 3T3 cytotoxicity test. The resulting data were evaluated using two strategies; namely, one based on using all endpoints determined in the WEC and the other including endpoints from both the WECmore » and the cytotoxicity test. On basis of the first analysis, the substance with the highest embryotoxic potential is NMP, followed by 5-hydroxy-N-methyl-pyrrolidone (5-HNMP), 2-hydroxy-N-methylsuccinimide (2-HMSI) and N-methylsuccinimide (MSI). Specific dysmorphogeneses induced by NMP and 5-HNMP were aberrations in the head region of the embryos, abnormal development of the second visceral arches and open neural pores. The second evaluation strategy used only two endpoints of the WEC, i.e. the no observed adverse effect concentration (NOAEC{sub WEC}) and the lowest concentration leading to dysmorphogenesis in 100% of the cultured embryos (IC{sub MaxWEC}). In addition to these WEC endpoints the IC{sub 503T3} from the cytotoxicity test (balb/c 3T3 fibroblasts) was included in the evaluation scheme. These three endpoints were applied to a prediction model developed during a validation study of the European Centre for the Validation of Alternative Methods (ECVAM) allowing the classification of the embryotoxic potential of each compound into three classes (non-, weakly- and strongly embryotoxic). Consistent results from both evaluation strategies were observed, whereby NMP and its metabolites revealed a direct embryotoxic potential. Hereby, only NMP and 5-HNMP induced specific embryotoxic effects and

  20. [Neuroprotective properties of pyroglutamic acid in combination with pyrrolidone].

    PubMed

    Lun'shina, E V; Gan'shina, T S; Makarova, L M; Pogorelyĭ, V E; Mirzoian, R S

    2003-01-01

    A new drug composition containing pyroglutamic acid and pyrrolidone produces a significant effect on the cerebral circulation in rats with global recurrent brain ischemia and in a model ischemic state under high radial gravitational overload. In the former case, the new drug increases the blood circulation in rats with the global ischemic damage to a greater extent than in the intact control group. Pretreatment with the pyroglutamic acid--pyrrolidone composition produced a 2-2.5-fold increase in the survival of rats in the ischemic state caused by the radial gravitational overload. The data obtained show evidence of a substantial neuroprotector action of the new drug composition.

  1. Discovery of Fevipiprant (NVP-QAW039), a Potent and Selective DP2 Receptor Antagonist for Treatment of Asthma

    PubMed Central

    2017-01-01

    Further optimization of an initial DP2 receptor antagonist clinical candidate NVP-QAV680 led to the discovery of a follow-up molecule 2-(2-methyl-1-(4-(methylsulfonyl)-2-(trifluoromethyl)benzyl)-1H-pyrrolo[2,3-b]pyridin-3-yl)acetic acid (compound 11, NVP-QAW039, fevipiprant), which exhibits improved potency on human eosinophils and Th2 cells, together with a longer receptor residence time, and is currently in clinical trials for severe asthma. PMID:28523115

  2. Potential utility of a peptide deformylase inhibitor (NVP PDF-713) against oxazolidinone-resistant or streptogramin-resistant Gram-positive organism isolates.

    PubMed

    Jones, Ronald N; Moet, Gary J; Sader, Helio S; Fritsche, Thomas R

    2004-05-01

    To evaluate the potency of a novel peptide deformylase inhibitor, NVP PDF-713, against Gram-positive organisms having resistances to linezolid or quinupristin/dalfopristin. A total of 45 strains from three genera (six species groups) were tested by reference broth microdilution methods. The mechanism of resistance to the oxazolidinone was determined by sequencing of the gene encoding the ribosomal target. NVP PDF-713 retained activity against linezolid-resistant staphylococci (MIC range 0.25-2 mg/L), Streptococcus oralis (MIC 0.5 mg/L), Enterococcus faecalis (MIC range 2-4 mg/L) and Enterococcus faecium (MIC range 0.5-4 mg/L). Quinupristin/dalfopristin-resistant E. faecium (MIC range 1-2 mg/L) and staphylococci (MIC range 0.12-2 mg/L) were also inhibited by NVP PDF-713. Many (10 of 13 strains) of the linezolid-resistant enterococci were resistant to vancomycin and these clinical strains had a G2576U ribosomal target mutation. NVP PDF-713 appears to be a promising clinical candidate among the peptide deformylase inhibitors for the treatment of infections caused by Gram-positive organisms that possess resistances to oxazolidinones or streptogramin combinations.

  3. Considerations for spectroscopy of liquid-exfoliated 2D materials: emerging photoluminescence of N-methyl-2-pyrrolidone.

    PubMed

    Ogilvie, Sean P; Large, Matthew J; Fratta, Giuseppe; Meloni, Manuela; Canton-Vitoria, Ruben; Tagmatarchis, Nikos; Massuyeau, Florian; Ewels, Christopher P; King, Alice A K; Dalton, Alan B

    2017-12-01

    N-methyl-2-pyrrolidone (NMP) has been shown to be the most effective solvent for liquid phase exfoliation and dispersion of a range of 2D materials including graphene, molybdenum disulphide (MoS 2 ) and black phosphorus. However, NMP is also known to be susceptible to sonochemical degradation during exfoliation. We report that this degradation gives rise to strong visible photoluminescence of NMP. Sonochemical modification is shown to influence exfoliation of layered materials in NMP and the optical absorbance of the solvent in the dispersion. The emerging optical properties of the degraded solvent present challenges for spectroscopy of nanomaterial dispersions; most notably the possibility of observing solvent photoluminescence in the spectra of 2D materials such as MoS 2 , highlighting the need for stable solvents and exfoliation processes to minimise the influence of solvent degradation on the properties of liquid-exfoliated 2D materials.

  4. Role of N-methyl-2-pyrrolidone for preparation of Fe3O4@SiO2 controlled the shell thickness

    NASA Astrophysics Data System (ADS)

    Wee, Sung-Bok; Oh, Hyeon-Cheol; Kim, Tae-Gyun; An, Gye-Seok; Choi, Sung-Churl

    2017-04-01

    We developed a simple and novel approach for the synthesis of Fe3O4@SiO2 nanoparticles with controlled shell thickness, and studied the mechanism. The introduction of N-methyl-2-pyrrolidone (NMP) led to trapping of monomer nuclei in single shell and controlled the shell thickness. Fe3O4@SiO2 controlled the shell thickness, showing a high magnetization value (64.47 emu/g). Our results reveal the role and change in the chemical structure of NMP during the core-shell synthesis process. NMP decomposed to 4-aminobutanoic acid in alkaline condition and decreased the hydrolysis rate of the silica coating process.

  5. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and pipe...

  6. Novel Biocompatible Thermoresponsive Poly(N-vinyl Caprolactam)/Clay Nanocomposite Hydrogels with Macroporous Structure and Improved Mechanical Characteristics.

    PubMed

    Shi, Kun; Liu, Zhuang; Yang, Chao; Li, Xiao-Ying; Sun, Yi-Min; Deng, Yi; Wang, Wei; Ju, Xiao-Jie; Xie, Rui; Chu, Liang-Yin

    2017-07-05

    Poly(N-vinyl caprolactam) (PVCL) hydrogels usually suffer from the imporous structure and poor mechanical characteristics as well as the toxicity of cross-linkers, although PVCL itself is biocompatible. In this paper, novel biocompatible thermoresponsive poly(N-vinyl caprolactam)/clay nanocomposite (PVCL-Clay) hydrogels with macroporous structure and improved mechanical characteristics are developed for the first time. The macroporosity in the hydrogel is introduced by using Pickering emulsions as templates, which contain N-vinyl caprolactam (VCL) monomer as dispersed phase and clay sheets as stabilizers at the interface. After polymerization, macropores are formed inside the hydrogels with the residual unreacted VCL droplets as templates. The three-dimensional PVCL polymer networks are cross-linked by the clay nanosheets. Due to the nanocomposite structure, the hydrogel exhibits better mechanical characteristics in comparison to the conventional PVCL hydrogels cross-linked by N,N'-methylene diacrylamide (BIS). The prepared PVCL-Clay hydrogel possesses remarkable temperature-responsive characteristics with a volume phase transition temperature (VPTT) around 35 °C, and provides a feasible platform for cell culture. With macroporous structure and good mechanical characteristics as well as flexible assembly performance, the proposed biocompatible thermoresponsive PVCL-Clay nanocomposite hydrogels are ideal material candidates for biomedical, analytical, and other applications such as entrapment of enzymes, cell culture, tissue engineering, and affinity and displacement chromatography.

  7. Developmental toxic effects of N-ethyl-2-pyrrolidone administered orally to rats.

    PubMed

    Saillenfait, A M; Gallissot, F; Sabaté, J P

    2007-01-01

    The developmental toxicity of N-ethyl-2-pyrrolidone (NEP) was studied in Sprague-Dawley rats after oral administration. Pregnant rats were given NEP at doses of 0 (distilled water), 50, 250, 500 and 750 mg kg(-1) day(-1), by gavage (5 ml kg(-1)), on gestational days (GD) 6-20. Maternal toxicity, as evidenced by reduction in body weight gain and food consumption, was observed in all NEP groups at the beginning of treatment (GD 6-9). The incidence of resorptions was significantly increased at 500 mg kg(-1) day(-1), and reached 83% at 750 mg kg(-1) day(-1). There was a dose-related decrease in fetal weight, which was significantly lower than control at 250 mg kg(-1) day(-1) and higher doses. The incidence of malformed fetuses per litter and the number of litters with malformed fetuses were significantly increased at 500 and 750 mg kg(-1) day(-1). Malformations mainly consisted of edema, anal atresia with absent tail, cardiovascular defects and fused cervical arches. Ossification of skull bones and sternebrae was significantly reduced at 500 and 750 mg kg(-1) day(-1). The incidence of supernumerary ribs was significantly elevated at 250 mg kg(-1) day(-1) and higher doses. In conclusion, NEP administered by gavage is embryotoxic and teratogenic at maternal toxic doses. (c) 2007 John Wiley & Sons, Ltd.

  8. Molecular effects of the phosphatidylinositol-3-kinase inhibitor NVP-BKM120 on T and B-cell acute lymphoblastic leukaemia.

    PubMed

    Pereira, João Kleber Novais; Machado-Neto, João Agostinho; Lopes, Matheus Rodrigues; Morini, Beatriz Corey; Traina, Fabiola; Costa, Fernando Ferreira; Saad, Sara Teresinha Olalla; Favaro, Patricia

    2015-09-01

    Constitutive activation of the PI3K pathway in T cell acute lymphoblastic leukaemia (T-ALL) has been reported and in a mouse model, PI3K activation, together with MYC, cooperates in Burkitt lymphoma (BL) pathogenesis. We investigated the effects of NVP-BKM120, a potent pan-class I PI3K inhibitor, in lymphoblastic leukaemia cell lines. Effects of NVP-BKM120 on cell viability, clonogenicity, apoptosis, cell cycle, cell signalling and autophagy were assessed in vitro on T-ALL (Jurkat and MOLT-4) and BL (Daudi and NAMALWA) cell lines. NVP-BKM120 treatment decreased cell viability and clonogenic growth in all tested cells. Moreover, the drug arrested cell cycling in association with a decrease in Cyclin B1 protein levels, and increased apoptosis. Immunoblotting analysis of cells treated with the drug revealed decreased phosphorylation, in a dose-dependent manner, of AKT, mTOR, P70S6K and 4EBP1, with stable total protein levels. Additionally, we observed a dose-dependent decrease in BAD phosphorylation, in association with augmented BAX:BCL2 ratio. Quantification of autophagy showed a dose-dependent increase in acidic vesicular organelles in all cells tested. In summary, our present study establishes that NVP-BKM120 presents an effective antitumour activity against T-ALL and BL cell lines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Enhancement of Mycophenolate Mofetil Permeation for Topical Use by Eucalyptol and N-Methyl-2-pyrrolidone

    PubMed Central

    Songkram, Chalermkiat

    2016-01-01

    Mycophenolate mofetil (MMF) is a prodrug of mycophenolic acid (MPA) which can be metabolized by esterase. MMF has been approved by the United States Food and Drug Administration (USFDA) for treatment of psoriasis patient with skin symptoms. However, it remains unclear whether MMF is efficiently effective to treat skin symptoms developed from psoriasis. The insufficient amount of MMF penetrating through the skin results in the treatment failure due to the difficulty in MMF penetration through the stratum corneum. Skin permeation enhancers such as eucalyptol (EUL) and N-methyl-2-pyrrolidone (NMP) potentially aid in increasing skin penetration. This study aimed to investigate the effects of a concentration ratio (% w/v) between two enhancers (EUL and NMP). The results showed that EUL enhanced MMF permeation with an enhancement ratio (ER) of 3.44 while NMP was not able to promote the penetration of MMF. Interestingly, the synergistic effect of the two enhancers was observed with a suitable ratio given that the ER was 8.21. EUL and NMP are promising enhancers for the development of MMF based skin product. PMID:27069715

  10. Antibacterial SnO2 nanorods as efficient fillers of poly(propylene fumarate-co-ethylene glycol) biomaterials.

    PubMed

    Díez-Pascual, Ana M; Díez-Vicente, Angel L

    2017-09-01

    Antibacterial and biocompatible SnO 2 nanorods have been easily synthesized through a hydrothermal process with the aid of a cationic surfactant, and incorporated as nanoreinforcements in poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)) copolymer crosslinked with N-vinyl-pyrrolidone (NVP) by sonication and thermal curing. The nanorods were randomly and individually dispersed inside the P(PF-co-EG) network, and noticeably increased the thermal stability, hydrophilicity, degree of crystallinity, protein absorption capability as well as stiffness and strength of the matrix, whilst decreased its level of porosity and biodegradation rate. More importantly, the resulting nanocomposites retained adequate rigidity and strength after immersion in a simulated body fluid (SBF) at 37°C. They also exhibited biocide action against Gram-positive and Gram-negative bacteria; their antibacterial effect was strong under UV-light illumination whilst in dark conditions was only moderate. Further, they did not cause toxicity on human dermal fibroblasts. The friction coefficient and wear rate strongly decreased with increasing nanorod loading under both dry and SBF conditions; the greatest drops in SBF were about 18-fold and 13-fold, respectively, compared to those of the copolymer network. These novel biomaterials are good candidates to be applied in the field of soft-tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Far-Infrared Spectroscopy of Anti-Vinyl Alcohol

    NASA Astrophysics Data System (ADS)

    Raston, Paul; Bunn, Hayley

    2016-06-01

    Vinyl alcohol can exist in two rotameric forms, known as syn- and anti- vinyl alcohol, where syn is the most stable. Both rotamers have been observed in the interstellar medium towards Sagittarius B2(N) making them of particular astrophysical importance. Vinyl alcohol has been subject to various spectroscopic investigations, however, the anti rotamer has only been obsvered in the microwave region. We report the high resolution (0.001 wn) FTIR spectrum of anti-vinyl alcohol collected at the infrared beamline facility of the Australian Synchrotron. Vinyl alcohol was produced via the pyrolysis of 2-chloroethanol at 900°C, and its far infrared spectrum reveals the presence of the strong νb{15} fundamental and hot band of anti-vinyl alcohol. Rotational and centrifugal distortion constants of this higher energy rotamer have since been determined for the νb{15} and 2νb{15} states, and the ground state constants have been refined. B. E. Turner, A. J. Apponi, ApJ 561, 207 (2001) M. Rodler, J. Mol. Spec. 114, 23 (1985) D-L Joo, et al., J. Mol. Spec. 197, 68 (1999)

  12. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34 Section 151.50-34 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall...

  13. Effect of drug loading method against the dissolution mechanism of encapsulated amoxicillin trihidrate drug in matrix of semi-IPN chitosan-poly (N-vinyl pyrrolidone) hydrogel with pore forming agent CaCO3

    NASA Astrophysics Data System (ADS)

    Nurjannah, Yanah; Budianto, Emil

    2018-04-01

    Heliobacter pylori (H.pylori) is a type of bacteria that causes inflammation in the lining of the stomach. The treatment of the bacterial infection by using conventional medicine which is amoxicillin trihidrate has a very short retention time in the stomach which is about 1-1,5 hours. Floating drug delivery system is expected to have a long retention time in the stomach so the efficiency of drug can be achieved. In this study, has been synthesized matrix of semi-IPN chitosan-Poly(N-vinil pyrrolidone) hydrogel with a pore-forming agent of CaCO3 under optimum conditions. Amoxicillin is encapsulated in a matrix hydrogel to be applied as a floating drug delivery system by in situ loading and post loading methods. The encapsulation efficiency and dissolution of in situ loading and post loading hydrogels are performed in vitro on gastric pH. In situ loading hydrogel shows higer percentage of encapsulation efficiency and dissolution compared to post loading hydrogel. The encapsulation efficiency of in situ and post loading hydrogels were 92,1% and 89,4%, respectively. The aim of drug dissolution by mathematical equation model is to know kinetics and the mecanism of dissolution. The kinetics release of in situ hydrogel tends to follow first order kinetics, while the post loading hydrogel follow the Higuchi model. The dissolution mecanism of hydrogels is erosion.

  14. Gas-phase infrared spectra of vinyl selenol and vinyl tellurol.

    PubMed

    Benidar, Abdessamad; Khater, Brahim; Guillemin, Jean-Claude; Gámez, José A; Yáñez, Manuel

    2009-11-19

    The infrared spectra (3500-500 cm(-1)) of gaseous vinyl selenol and vinyl tellurol have been recorded at 0.1 cm(-1) resolution. For the latter the spectra were obtained at room temperature, but for the former a temperature of -40 degrees C was required because of the chemical instability of vinyl selenol at room temperature. To compensate the very weak vapor pressure of vinyl tellurol at room temperature, a long optical path up to 136 m was necessary to record its spectrum. B3LYP density functional theory (DFT) calculations have been performed to assign the different absorption bands. Since an unambiguous assignment of the absorption bands requires a precise knowledge on the relative abundance of the syn and gauche rotamers of these compounds, their relative energies and their anharmonic vibrational frequencies were obtained using a very extended Def2-QZVP basis set. Two rotamers, the syn, which is planar, and a nonplanar gauche, were found to be local minima for both compounds. The gauche rotamer presents two degenerate conformers, which differ by the position of the SeH (TeH) hydrogen atom above or below the molecular plane. Our theoretical results are in good agreement with the main features of the experimental spectra. Fundamental bands and some combination bands of vinyl selenol and vinyl tellurol were assigned and compared with those of vinyl alcohol and vinyl thiol, whose spectra had been reported previously in the literature.

  15. Gas-Phase Infrared Spectra of Vinyl Selenol and Vinyl Tellurol

    NASA Astrophysics Data System (ADS)

    Benidar, Abdessamad; Khater, Brahim; Guillemin, Jean-Claude; Gámez, José A.; Yáñez, Manuel

    2009-10-01

    The infrared spectra (3500-500 cm-1) of gaseous vinyl selenol and vinyl tellurol have been recorded at 0.1 cm-1 resolution. For the latter the spectra were obtained at room temperature, but for the former a temperature of -40 °C was required because of the chemical instability of vinyl selenol at room temperature. To compensate the very weak vapor pressure of vinyl tellurol at room temperature, a long optical path up to 136 m was necessary to record its spectrum. B3LYP density functional theory (DFT) calculations have been performed to assign the different absorption bands. Since an unambiguous assignment of the absorption bands requires a precise knowledge on the relative abundance of the syn and gauche rotamers of these compounds, their relative energies and their anharmonic vibrational frequencies were obtained using a very extended Def2-QZVP basis set. Two rotamers, the syn, which is planar, and a nonplanar gauche, were found to be local minima for both compounds. The gauche rotamer presents two degenerate conformers, which differ by the position of the SeH (TeH) hydrogen atom above or below the molecular plane. Our theoretical results are in good agreement with the main features of the experimental spectra. Fundamental bands and some combination bands of vinyl selenol and vinyl tellurol were assigned and compared with those of vinyl alcohol and vinyl thiol, whose spectra had been reported previously in the literature.

  16. Rapid Quantification of N-Methyl-2-pyrrolidone in Polymer Matrices by Thermal Desorption-GC/MS.

    PubMed

    Kim, Young-Min; Kim, Jae Woo; Moon, Hye Mi; Lee, Min-Jin; Hosaka, Akihiko; Watanabe, Atsushi; Teramae, Norio; Park, Young-Kwon; Myung, Seung-Woon

    2017-01-01

    Analysis of a residual solvent in polymeric materials has become an important issue due to the increased regulations and standards for its use. N-Methyl-2-pyrrolidone (NMP) is a solvent widely used in many industries and restricted as one of the chemicals under EU REACH regulations due to its potential harmful effects. In this study, thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) is applied for the quantitative analysis of NMP with the use of a polymer-coated sample cup. By using the polymer-coated sample cup, the vaporization of NMP was prevented during waiting time before TD-GC/MS analysis. The calibration curve for the TD method showed good linearity (correlation coefficient, r 2 = 0.9998) and precision values (below 5.3% RSD). NMP recovery rates in different polymer matrices (PS, PMMA and PVC) were in the range of 98.8 to 106.6% with RSD values below 5.0%. The quantification result (600 mg NMP/kg PVC) for the blind NMP carrying sample in a PVC matrix by TD-GC/MS was higher than that (532 mg NMP/kg PVC) by solvent extraction-GC/MS method.

  17. Millimeter Wave Spectrum and Astronomical Search for Vinyl Formate

    NASA Astrophysics Data System (ADS)

    Alonso, E. R.; Kolesniková, L.; Tercero, B.; Cabezas, C.; Alonso, J. L.; Cernicharo, J.; Guillemin, J.-C.

    2016-11-01

    Previous detections of methyl and ethyl formate make other small substituted formates potential candidates for observation in the interstellar medium. Among them, vinyl formate is one of the simplest unsaturated carboxylic ester. The aim of this work is to provide direct experimental frequencies of the ground vibrational state of vinyl formate in a large spectral range for astrophysical use. The room-temperature rotational spectrum of vinyl formate has been measured from 80 to 360 GHz and analyzed in terms of Watson’s semirigid rotor Hamiltonian. Two thousand six hundred transitions within J = 3-88 and K a = 0-28 were assigned to the most stable conformer of vinyl formate and a new set of spectroscopic constants was accurately determined. Spectral features of vinyl formate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of vinyl formate are provided.

  18. MILLIMETER WAVE SPECTRUM AND ASTRONOMICAL SEARCH FOR VINYL FORMATE

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

    Alonso, E. R.; Kolesniková, L.; Cabezas, C.

    2016-11-20

    Previous detections of methyl and ethyl formate make other small substituted formates potential candidates for observation in the interstellar medium. Among them, vinyl formate is one of the simplest unsaturated carboxylic ester. The aim of this work is to provide direct experimental frequencies of the ground vibrational state of vinyl formate in a large spectral range for astrophysical use. The room-temperature rotational spectrum of vinyl formate has been measured from 80 to 360 GHz and analyzed in terms of Watson’s semirigid rotor Hamiltonian. Two thousand six hundred transitions within J = 3–88 and K {sub a} = 0–28 were assignedmore » to the most stable conformer of vinyl formate and a new set of spectroscopic constants was accurately determined. Spectral features of vinyl formate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of vinyl formate are provided.« less

  19. Effect of chain structure on hydrogen bonding in vinyl acetate - vinyl alcohol copolymers

    NASA Astrophysics Data System (ADS)

    Merekalova, Nadezhda D.; Bondarenko, Galina N.; Denisova, Yuliya I.; Krentsel, Liya B.; Litmanovich, Arkadiy D.; Kudryavtsev, Yaroslav V.

    2017-04-01

    FTIR spectroscopy and semi-empirical AM1 method are used to study hydrogen bonding in multiblock and random equimolar copolymers of vinyl acetate and vinyl alcohol. An energetically beneficial zip-holder complex, built on multiple inter- and intrachain hydroxyl-hydroxyl bonds and an intrachain hydroxyl-acetyloxy bond, can be formed between two vinyl alcohol sequences. As a result, multiblock copolymers reveal stronger degree of association that affects crystallinity, as well as various rheological and relaxation properties discussed in the literature. Macromolecular complexes in random copolymers are weak and tend to be destroyed in the presence of residual DMF solvent and adsorbed water. Nevertheless, a rather stable interchain quaternary complex can be formed that includes vinyl alcohol and vinyl acetate units and DMF and water molecules. For a single chain it is shown that an H-bond between neighboring vinyl alcohol and vinyl acetate monomer units mostly engages a carbonyl oxygen atom of the vinyl acetate, if the vinyl alcohol belongs to a short (<5 units) sequence, and an ether oxygen atom in the other case. On the whole, the quantum chemistry calculations shed much light on the origin of distinctions in the copolymer FTIR spectra, which may seem subtle when considered standalone.

  20. Fabrication of TiN nanorods by electrospinning and their electrochemical properties

    NASA Astrophysics Data System (ADS)

    Sun, Dongfei; Lang, Junwei; Yan, Xingbin; Hu, Litian; Xue, Qunji

    2011-05-01

    TiN nanorods were synthesized using electrospinning technique followed by thermolysis in different atmospheres. A dimethyl formamide-ethanol solution of poly-(vinyl pyrrolidone) and Ti (IV)-isopropoxide was used as the electrospinning precursor solution and as-spun nanofibers were calcined at 500 °C in air to generate TiO 2 nanofibers. Subsequently, a conversion from TiO 2 nanofibers to TiN nanorods was employed by the nitridation treatment at 600˜1400 °C in ammonia atmosphere. A typical characteristic of the final products was that the pristine nanofibers were cut into nanorods. The conversion from TiO 2 to TiN was realized when the nitridation temperature was above 800 °C. As-prepared nanorods were composed of TiN nano-crystallites and the average crystallite size gradually increased with the increase of the nitridation temperature. Electrochemical properties of TiN nanorods showed strong dependence on the nitridation temperature. The maximum value of the specific capacitance was obtained from the TiN nanorods prepared at 800 °C.

  1. Synthesis of PVP-stabilized ruthenium colloids with low boiling point alcohols.

    PubMed

    Zhang, Yuqing; Yu, Jiulong; Niu, Haijun; Liu, Hanfan

    2007-09-15

    A route to the preparation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium colloids by refluxing ruthenium(III) chloride in low boiling point alcohols was developed. Deep purple colloids with shuttle-like ruthenium particles were also synthesized. XPS measurement verified the nanoparticles were in the metallic state. The morphology of metal nanoparticles was characterized by UV-visible absorption spectrophotometry, TEM and XRD.

  2. Vinyl Chloride

    Cancer.gov

    Learn about vinyl chloride, which can raise the risk of a rare form of liver cancer, as well as brain and lung cancers, and leukemia and lymphoma. Vinyl chloride is used primarily to make PVC, a substance used in products such as pipes.

  3. A comparison between the effects of ginger, pyridoxine (vitamin B6) and placebo for the treatment of the first trimester nausea and vomiting of pregnancy (NVP).

    PubMed

    Sharifzadeh, Fatemeh; Kashanian, Maryam; Koohpayehzadeh, Jalil; Rezaian, Fatemeh; Sheikhansari, Narges; Eshraghi, Nooshin

    2017-07-07

    distress) and distress of vomit. Ginger is more effective than placebo for the treatment of mild to moderate NVP and is comparable with vitamin B6. Trial registration number and registry website: IRCT2015020320923N1.

  4. Characterization of the novel and specific PI3Kα inhibitor NVP-BYL719 and development of the patient stratification strategy for clinical trials.

    PubMed

    Fritsch, Christine; Huang, Alan; Chatenay-Rivauday, Christian; Schnell, Christian; Reddy, Anupama; Liu, Manway; Kauffmann, Audrey; Guthy, Daniel; Erdmann, Dirk; De Pover, Alain; Furet, Pascal; Gao, Hui; Ferretti, Stephane; Wang, Youzhen; Trappe, Joerg; Brachmann, Saskia M; Maira, Sauveur-Michel; Wilson, Christopher; Boehm, Markus; Garcia-Echeverria, Carlos; Chene, Patrick; Wiesmann, Marion; Cozens, Robert; Lehar, Joseph; Schlegel, Robert; Caravatti, Giorgio; Hofmann, Francesco; Sellers, William R

    2014-05-01

    Somatic PIK3CA mutations are frequently found in solid tumors, raising the hypothesis that selective inhibition of PI3Kα may have robust efficacy in PIK3CA-mutant cancers while sparing patients the side-effects associated with broader inhibition of the class I phosphoinositide 3-kinase (PI3K) family. Here, we report the biologic properties of the 2-aminothiazole derivative NVP-BYL719, a selective inhibitor of PI3Kα and its most common oncogenic mutant forms. The compound selectivity combined with excellent drug-like properties translates to dose- and time-dependent inhibition of PI3Kα signaling in vivo, resulting in robust therapeutic efficacy and tolerability in PIK3CA-dependent tumors. Novel targeted therapeutics such as NVP-BYL719, designed to modulate aberrant functions elicited by cancer-specific genetic alterations upon which the disease depends, require well-defined patient stratification strategies in order to maximize their therapeutic impact and benefit for the patients. Here, we also describe the application of the Cancer Cell Line Encyclopedia as a preclinical platform to refine the patient stratification strategy for NVP-BYL719 and found that PIK3CA mutation was the foremost positive predictor of sensitivity while revealing additional positive and negative associations such as PIK3CA amplification and PTEN mutation, respectively. These patient selection determinants are being assayed in the ongoing NVP-BYL719 clinical trials.

  5. Discovery and characterization of NVP-QAV680, a potent and selective CRTh2 receptor antagonist suitable for clinical testing in allergic diseases.

    PubMed

    Sandham, David A; Arnold, Nicola; Aschauer, Heinrich; Bala, Kamlesh; Barker, Lucy; Brown, Lyndon; Brown, Zarin; Budd, David; Cox, Brian; Docx, Cerys; Dubois, Gerald; Duggan, Nicholas; England, Karen; Everatt, Brian; Furegati, Marcus; Hall, Edward; Kalthoff, Frank; King, Anna; Leblanc, Catherine J; Manini, Jodie; Meingassner, Josef; Profit, Rachael; Schmidt, Alfred; Simmons, Jennifer; Sohal, Bindi; Stringer, Rowan; Thomas, Matthew; Turner, Katharine L; Walker, Christoph; Watson, Simon J; Westwick, John; Willis, Jennifer; Williams, Gareth; Wilson, Caroline

    2013-11-01

    Optimization of a 7-azaindole-3-acetic acid CRTh2 receptor antagonist chemotype derived from high throughput screening furnished a highly selective compound NVP-QAV680 with low nM functional potency for inhibition of CRTh2 driven human eosinophil and Th2 lymphocyte activation in vitro. The molecule exhibited good oral bioavailability in the rat, combined with efficacy in rodent CRTh2-dependent mechanistic and allergic disease models and was suitable for clinical development. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Curcumin Significantly Enhances Dual PI3K/Akt and mTOR Inhibitor NVP-BEZ235-Induced Apoptosis in Human Renal Carcinoma Caki Cells through Down-Regulation of p53-Dependent Bcl-2 Expression and Inhibition of Mcl-1 Protein Stability

    PubMed Central

    Cho, Il Je; Kim, Sang Chan; Kwon, Taeg Kyu

    2014-01-01

    The PI3K/Akt and mTOR signaling pathways are important for cell survival and growth, and they are highly activated in cancer cells compared with normal cells. Therefore, these signaling pathways are targets for inducing cancer cell death. The dual PI3K/Akt and mTOR inhibitor NVP-BEZ235 completely inhibited both signaling pathways. However, NVP-BEZ235 had no effect on cell death in human renal carcinoma Caki cells. We tested whether combined treatment with natural compounds and NVP-BEZ235 could induce cell death. Among several chemopreventive agents, curcumin, a natural biologically active compound that is extracted from the rhizomes of Curcuma species, markedly induced apoptosis in NVP-BEZ235-treated cells. Co-treatment with curcumin and NVP-BEZ235 led to the down-regulation of Mcl-1 protein expression but not mRNA expression. Ectopic expression of Mcl-1 completely inhibited curcumin plus NVP-NEZ235-induced apoptosis. Furthermore, the down-regulation of Bcl-2 was involved in curcumin plus NVP-BEZ235-induced apoptosis. Curcumin or NVP-BEZ235 alone did not change Bcl-2 mRNA or protein expression, but co-treatment reduced Bcl-2 mRNA and protein expression. Combined treatment with NVP-BEZ235 and curcumin reduced Bcl-2 expression in wild-type p53 HCT116 human colon carcinoma cells but not p53-null HCT116 cells. Moreover, Bcl-2 expression was completely reversed by treatment with pifithrin-α, a p53-specific inhibitor. Ectopic expression of Bcl-2 also inhibited apoptosis in NVP-BE235 plus curcumin-treated cells. In contrast, NVP-BEZ235 combined with curcumin did not have a synergistic effect on normal human skin fibroblasts and normal human mesangial cells. Taken together, combined treatment with NVP-BEZ235 and curcumin induces apoptosis through p53-dependent Bcl-2 mRNA down-regulation at the transcriptional level and Mcl-1 protein down-regulation at the post-transcriptional level. PMID:24743574

  7. Specific apoptosis induction by the dual PI3K/mTor inhibitor NVP-BEZ235 in HER2 amplified and PIK3CA mutant breast cancer cells

    PubMed Central

    Brachmann, Saskia M.; Hofmann, Irmgard; Schnell, Christian; Fritsch, Christine; Wee, Susan; Lane, Heidi; Wang, Shaowen; Garcia-Echeverria, Carlos; Maira, Sauveur-Michel

    2009-01-01

    NVP-BEZ235 is a dual PI3K/mTOR inhibitor currently in phase I clinical trials. We profiled this compound against a panel of breast tumor cell lines to identify the patient populations that would benefit from such treatment. In this setting, NVP-BEZ235 selectively induced cell death in cell lines presenting either HER2 amplification and/or PIK3CA mutation, but not in cell lines with PTEN loss of function or KRAS mutations, for which resistance could be attributed, in part to ERK pathway activity. An in depth analysis of death markers revealed that the cell death observed upon NVP-BEZ235 treatment could be recapitulated with other PI3K inhibitors and that this event is linked to active PARP cleavage indicative of an apoptotic process. Moreover, the effect seemed to be partly independent of the caspase-9 executioner and mitochondrial activated caspases, suggesting an alternate route for apoptosis induction by PI3K inhibitors. Overall, this study will provide guidance for patient stratification for forthcoming breast cancer phase II trials for NVP-BEZ235. PMID:20007781

  8. Aggregate development in C 60/N-methyl-2-pyrrolidone solution and its mixture with water as revealed by extraction and mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Kyzyma, O. A.; Korobov, M. V.; Avdeev, M. V.; Garamus, V. M.; Snegir, S. V.; Petrenko, V. I.; Aksenov, V. L.; Bulavin, L. A.

    2010-06-01

    The aggregate development in C 60/N-methyl-2-pyrrolidone (C 60/NMP) solution with time is studied by the extraction (hexane) and mass spectroscopy. It is shown that only molecular C 60 in NMP is extracted in hexane, which makes it possible to follow a change in the concentration of non-aggregated fullerene in C 60/NMP during the aggregate growth. It is concluded that almost all fullerene dissolved in NMP is in the aggregates after one month. The reorganization of the aggregates is detected when water is added to the aggregated solution C 60/NMP. Both methods prove that in this case individual fullerene molecules are detached from the aggregates, which contradicts somewhat to complete insolubility of C 60 in water.

  9. Quantification of four major metabolites of embryotoxic N-methyl- and N-ethyl-2-pyrrolidone in human urine by cooled-injection gas chromatography and isotope dilution mass spectrometry.

    PubMed

    Schindler, Birgit K; Koslitz, Stephan; Meier, Swetlana; Belov, Vladimir N; Koch, Holger M; Weiss, Tobias; Brüning, Thomas; Käfferlein, Heiko U

    2012-04-17

    N-Methyl- and N-ethyl-2-pyrollidone (NMP and NEP) are frequently used industrial solvents and were shown to be embryotoxic in animal experiments. We developed a sensitive, specific, and robust analytical method based on cooled-injection (CIS) gas chromatography and isotope dilution mass spectrometry to analyze 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), two newly identified presumed metabolites of NEP, and their corresponding methyl counterparts (5-HNMP, 2-HMSI) in human urine. The urine was spiked with deuterium-labeled analogues of these metabolites. The analytes were separated from urinary matrix by solid-phase extraction and silylated prior to quantification. Validation of this method was carried out by using both, spiked pooled urine samples and urine samples from 56 individuals of the general population with no known occupational exposure to NMP and NEP. Interday and intraday imprecision was better than 8% for all metabolites, while the limits of detection were between 5 and 20 μg/L depending on the analyte. The high sensitivity of the method enables us to quantify NMP and NEP metabolites at current environmental exposures by human biomonitoring.

  10. Efficacy and durability of nevirapine in antiretroviral drug näive patients.

    PubMed

    Lange, Joep M A

    2003-09-01

    Nevirapine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that was first reported in the scientific literature in 1990. Varying doses of nevirapine (NVP) and a number of regimens containing this NNRTI have been studied in antiretroviral (ARV) näive patients. Four key studies have compared the efficacy and safety of triple drug regimens containing NVP in ARV näive, HIV-1 infected patients. The INCAS study was the first demonstration of how to use NVP in an effective and durable manner: as a component of a triple drug regimen. The COMBINE Study was a comparison of protease inhibitor (PI)-based and NVP-based triple regimens. The Atlantic Study is comparing the safety and efficacy of three triple drug regimens in ARV näive patients. In this study, treatment consists of a divergent drug regimen (PI and nucleoside reverse transcriptase inhibitors, NRTIs) targeting both HIV-1 protease and reverse transcriptase or a convergent regimen targeting reverse transcriptase alone (three NRTIs or two NRTIs plus a NNRTI). A clinical endpoint study (BI 1090) compared the efficacy and durability of multi-drug regimens in ARV näive patients with high baseline plasma HIV-1 RNA levels (pVLs) and low peripheral blood CD4+ lymphocyte counts. Data from these studies confirm that triple regimens containing NVP suppressed viral replication for up to one year, even when the ARV näive patients had low CD4+ cell counts at baseline. Nevirapine-containing regimens suppressed pVLs to < 50 copies/ mL in approximately 50% of patients in the studies discussed (Intent to Treat analyses). Data from 96 weeks of follow up in the Atlantic Study demonstrates that the regimens containing didanosine and stavudine plus indinavir or NVP were significantly more successful in suppressing pVLs to < 50 copies/mL during this period than a regimen composed of these NRTIs and lamivudine (p < or = 0.001). As with other ARV drugs, NVP should always be used as part of a fully suppressive ARV regimen

  11. Sol–gel auto-combustion synthesis of PVP/CoFe{sub 2}O{sub 4} nanocomposite and its magnetic characterization

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

    Kurtan, U.; Topkaya, R., E-mail: rtopkaya@gyte.edu.tr; Baykal, A.

    2013-11-15

    Graphical abstract: - Highlights: • The Poly(vinyl pyrrolidone) (PVP) was used as a surface capping agent. • PVP/CoFe{sub 2}O{sub 4} nanocomposite was synthesized by a sol-gel auto-combustion method. • The existence of the spin-disordered surface layer was established. - Abstract: Poly(vinyl pyrrolidone)/CoFe{sub 2}O{sub 4} nanocomposite has been fabricated by a sol–gel auto-combustion method. Poly(vinyl pyrrolidone) was used as a reducing agent as well as a surface capping agent to prevent particle aggregation and stabilize the particles. The average crystallite size estimated from X-ray line profile fitting was found to be 20 ± 7 nm. The high field irreversibility and unsaturatedmore » magnetization behaviours indicate the presence of the core–shell structure in the sample. The exchange bias effect observed at 10 K suggests the existence of the magnetically aligned core surrounded by spin-disordered surface layer. The reduced remanent magnetization value of 0.6 at 10 K (higher than the theoretical value of 0.5) shows the PVP/CoFe{sub 2}O{sub 4} nanocomposite to have cubic magnetocrystalline anisotropy according to the Stoner–Wohlfarth model.« less

  12. Synthesis and characterization of psyllium-NVP based drug delivery system through radiation crosslinking polymerization

    NASA Astrophysics Data System (ADS)

    Singh, Baljit; Kumar, S.

    2008-08-01

    In order to develop the hydrogels meant for the drug delivery, we have prepared psyllium- N-vinylpyrrolidone (NVP) based hydrogels by radiation induced crosslinking. Polymers were characterized with SEMs, FTIR and swelling studies. Swelling of the hydrogels was studied as a function of monomer concentration, total radiation dose, temperature, pH and [NaCl] of the swelling medium. The swelling kinetics of the hydrogels and release dynamics of anticancer model drug (5-fluorouracil) from the hydrogels have been carried out for the evaluation of swelling and drug release mechanism. It has been observed that diffusion exponent ' n' have 0.8, 0.9, 0.8 and gel characteristics constant ' k' have 9.22 × 10 -3, 2.06 × 10 -3, 11.72 × 10 -3 values for the release of drug from the drug loaded hydrogels in distilled water, pH 2.2 buffer and pH 7.4 buffer, respectively. The present study shows that the release of drug from the hydrogels occurred through Non-Fickian diffusion mechanism.

  13. Boron Nitride Nanotubes and Nanoplatelets as Reinforcing Agents of Polymeric Matrices for Bone Tissue Engineering

    PubMed Central

    Farshid, Behzad; Lalwani, Gaurav; Mohammadi, Meisam Shir; Simonsen, John; Sitharaman, Balaji

    2016-01-01

    This study investigates the mechanical properties and in vitro cytotoxicity of one- and two-dimensional boron nitride nanomaterials-reinforced biodegradable polymeric nanocomposites. Poly(propylene fumarate) (PPF) nanocomposites were fabricated using crosslinking agent N-vinyl pyrrolidone (NVP) and inorganic nanomaterials: boron nitride nanotubes (BNNTs) and boron nitride nanoplatelets (BNNPs) dispersed at 0.2 wt.% in the polymeric matrix. The incorporation of BNNPs and BNNTs resulted in a ~38% and ~15% increase in compressive (young's) modulus, and ~31% and ~6% increase in compressive yield strength compared to PPF control, respectively. The nanocomposites showed a time-dependent increased protein adsorption for only collagen-I protein. The cytotoxicity evaluation of aqueous BNNT and BNNP dispersions (at 1-100 μg/mL concentrations) using a representative murine MC3T3 preosteoblast cell line showed cytocompatibility of BNNTs and BNNPs (~73-99% viability). The cytotoxicity evaluation of media extracts of nanocomposites prior to crosslinking, after crosslinking and upon degradation (using 1X-100X dilutions) showed dose-dependent cytotoxicity responses. Crosslinked nanocomposites showed excellent (~79-100%) cell viability, cellular attachment (~57-67%), and spreading similar to cells grown on the surface of tissue culture polystyrene (TCPS) control. The media extracts of degradation products showed a dose-dependent cytotoxicity. The favorable cytocompatibility results in combination with improved mechanical properties of BNNT and BNNP nanocomposites opens new avenues for further in vitro and in vivo safety and efficacy studies for their bone tissue engineering applications. PMID:26526153

  14. Synthesis of poly(N-isopropylacrylamide) particles for metal affinity binding of peptides

    PubMed Central

    Tsai, Hsin-Yi; Lee, Alexander; Peng, Wei; Yates, Matthew Z.

    2013-01-01

    Temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgel particles with metal affinity ligands were prepared for selective binding of peptides containing the His6-tag (six consecutive histidine residues). The PNIPAM particles were copolymerized with the functional ligand vinylbenzyl iminodiacetic acid (VBIDA) through a two-stage dispersion polymerization using poly(N-vinyl pyrrolidone) (PVP) as a steric stabilizer. The resulting particles were monodisperse in size and colloidally stable over a wide range of temperature and ionic strength due to chemically grafted PVP chains. The particle size was also found to be sensitive to ionic strength and pH of the aqueous environment, likely due to the electrostatic repulsion between ionized VBIDA groups. Divalent nickel ions were chelated to the VBIDA groups, allowing selective metal affinity attachment of a His6-Cys peptide. The peptide was released upon the addition of the competitive ligand imidazole, demonstrating that the peptide attachment to the particles is reversible and selective. PMID:24176889

  15. Insulin-Like Growth Factor-Type 1 Receptor Inhibitor NVP-AEW541 Enhances Radiosensitivity of PTEN Wild-Type but Not PTEN-Deficient Human Prostate Cancer Cells

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

    Isebaert, Sofie F., E-mail: sofie.isebaert@med.kuleuven.be; Swinnen, Johannes V.; McBride, William H.

    2011-09-01

    Purpose: During the past decade, many clinical trials with both monoclonal antibodies and small molecules that target the insulin-like growth factor-type 1 receptor (IGF-1R) have been launched. Despite the important role of IGF-1R signaling in radioresistance, studies of such agents in combination with radiotherapy are lagging behind. Therefore, the aim of this study was to investigate the effect of the small molecule IGF-1R kinase inhibitor NVP-AEW541 on the intrinsic radioresistance of prostate cancer cells. Methods and Materials: The effect of NVP-AEW541 on cell proliferation, cell viability, IGF-1R signaling, radiosensitivity, cell cycle distribution, and double strand break repair was determined inmore » three human prostate cancer cell lines (PC3, DU145, 22Rv1). Moreover, the importance of the PTEN pathway status was explored by means of transfection experiments with constitutively active Akt or inactive kinase-dead Akt. Results: NVP-AEW541 inhibited cell proliferation and decreased cell viability in a time-and dose-dependent manner in all three cell lines. Radiosensitization was observed in the PTEN wild-type cell lines DU145 and 22Rv1 but not in the PTEN-deficient PC3 cell line. NVP-AEW541-induced radiosensitization coincided with downregulation of phospho-Akt levels and high levels of residual double strand breaks. The importance of PTEN status in the radiosensitization effect was confirmed by transfection experiments with constitutively active Akt or inactive kinase-dead Akt. Conclusions: NVP-AEW541 enhances the effect of ionizing radiation in PTEN wild-type, but not in PTEN-deficient, prostate cancer cells. Proper patient selection based on the PTEN status of the tumor will be critical to the achievement of optimal results in clinical trials in which the combination of radiotherapy and this IGF-1R inhibitor is being explored.« less

  16. Toxicology and Carcinogenesis Studies of Mixtures of 3'-Azido-3'-Deoxythymidine (AZT), Lamivudine (3TC), and Nevirapine (NVP) (CAS Nos. 30516-87-1, 134678-17-4, 129618-40-2) in Genetically Modified C3B6.129F1-Trp53(tm1Brd) N12 Haploinsufficient Mice (in utero and postnatal gavage studies).

    PubMed

    2013-10-01

    3'-Azido-3'-deoxythymidine (AZT) is the most widely used and evaluated chemotherapeutic agent for the treatment of persons with acquired immune deficiency syndrome (AIDS). Antiviral therapy is essential for treatment and prevention of AIDS in adults and children infected with human immunodeficiency virus (HIV), and to prevent mother-to-child transmission of HIV during pregnancy and labor. The studies described in this report were designed to determine possible long-term sequelae from AZT treatment, often used in combination with other antiviral drugs, such as lamivudine (3TC) and nevirapine (NVP) in preventing mother-to-child transmission of HIV. Male and female heterozygous F1 p53+/- mice were exposed to AZT, 3TC, NVP, or combinations of the chemicals in utero on gestation days (GD) 12 through 18, then administered the same chemical or combination of chemicals by gavage from postnatal day (PND) 1 through PND 28 and then observed until 45 weeks of age. Vehicle control mice received only an aqueous solution containing 0.2% methylcellulose and 0.1% Tween 80. Mice were dosed twice daily until PND 28. Genetic toxicology studies were conducted in mouse peripheral blood erythrocytes. The study compared three combination doses of AZT, 3TC and NVP (AZT/3TC/NVP-L, AZT/3TC/NVP-M, and AZT/3TC/NVP-H) with the vehicle controls, and compared the individual components with each other at the highest dose (AZT-H, 3TC-H, NVP-H, AZT/3TC-H and AZT/3TC/NVP-H). Because exposure to AZT/3TC/NVP-M and AZT/3TC/NVP-H reduced pup survival, additional litters were required to provide sufficient pups to load the 45-week study. 45-WEEK STUDY: In general, survival was relatively high once the pup exposure phase had been completed, with at least 75% of the mice surviving to terminal sacrifice in all groups. For males, survival was significantly greater in the AZT/3TC/NVP-L and AZT/3TC/NVP-M groups relative to the vehicle control group. There were no significant differences in survival between high

  17. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Premarket Approval (HFS-200), Center for Food Safety and Applied Nutrition, Food and Drug Administration... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-vinyl acetate-vinyl alcohol copolymers. 177.1360 Section 177.1360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  18. Commercial broth microdilution panel validation and reproducibility trials for NVP PDF-713 (LBM 415), a novel inhibitor of bacterial peptide deformylase.

    PubMed

    Fritsche, T R; Moet, G J; Jones, R N

    2004-09-01

    NVP PDF-713 (LBM 415) is a peptide deformylase inhibitor being progressed into clinical trials. Dry-form broth microdilution panels of NVP PDF-713 were compared to reference MIC panels of 552 recent clinical isolates. Most (99.2%) dry-form MIC results were within +/- 1 log(2) dilution of the reference panel MICs. Of the bacteria tested, Streptococcus pneumoniae and Haemophilus influenzae showed a bias towards higher and lower MICs, respectively. Same-day and between-day reproducibility tests showed that 98.9% and 96.7% of MIC values, respectively, were within +/- 1 log(2) dilution step, thereby demonstrating a high degree of reliability of the dry-form MIC product for clinical studies.

  19. Rhodium/Silver-Cocatalyzed Transannulation of N-Sulfonyl-1,2,3-triazoles with Vinyl Azides: Divergent Synthesis of Pyrroles and 2 H-Pyrazines.

    PubMed

    Zhang, Lin; Sun, Ge; Bi, Xihe

    2016-11-07

    The first cyclization reaction between vinyl azides and N-sulfonyl-1,2,3-triazoles is reported. A Rh/Ag binary metal catalyst system proved to be necessary for the successful cyclization. By varying the structure of vinyl azides, such reaction allows the divergent synthesis of pyrroles and 2H-pyrazines. The cyclization reactions feature a broad substrate scope, good functional group tolerance, high reaction efficiency, and good to high product yields. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Thermal and chemical stabilization of ethylene/vinyl acetate/vinyl alcohol (EVA-OH) terpolymers under nitroplasticizer environments

    DOE PAGES

    Yang, Dali; Hubbard, Kevin M.; Henderson, Kevin C.; ...

    2014-09-17

    Here, we compare the aging behaviors of cross-linked ethylene/vinyl acetate/vinyl alcohol terpolymers, also referred to as EVA-OH, when they are either immersed in nitroplasticizer (NP) liquid or exposed to NP vapor at different temperatures. And while thermogravimetric analysis and differential scanning calorimetry are used to probe the thermal stability of aged NP and polymers, Fourier transform infrared, gel permeation chromatography, ultra-violet/vis, and nuclear magnetic resonance are used to probe their structural changes over the aging process. Our study confirms that NP degrades through C[BOND]N cleavage, and releases HONO molecules at a slightly elevated temperature (<75°C). As these molecules accumulate inmore » the vapor phase, they react among themselves to create an acidic environment. Therefore, these chemical constituents in the NP vapor significantly accelerate the hydrolysis of EVA-OH polymer. When the hydrolysis occurs in both vinyl acetate and urethane groups and the scission at the cross-linker progresses, EVA-OH becomes vulnerable to further degradation in the NP vapor environment. Finally, through the comprehensive characterization, the possible degradation mechanisms of the terpolymers are proposed.« less

  1. Methacrylate derivatives incorporating pyroglutamic acid.

    PubMed

    Smith, Tara J; Mathias, Lon J

    2002-01-01

    Methacrylates containing pyroglutamic acid were synthesized in good yields. Methyl alpha-pyroglutamyl methylacrylate (PyMM) and methyl alpha-pyroglutamidoundecanoyl methylacrylate (PyUM) give very fast photopolymerization rates both in homopolymerizations and with widely used commercial monomers N-vinyl pyrrolidinone (NVP) and hydroxyethyl methacrylate (HEMA). Soluble or cross-linked homopolymers can be obtained depending upon polymerization temperature. Pyroglutamic methacrylates polymerize without added initiator in the melt. Solution cast, photocured, and thermally cured coatings gave good to excellent adhesion to poly(ethylene terephthalate) and glass surfaces.

  2. Microbial reductive dehalogenation of vinyl chloride

    DOEpatents

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Nannhein, DE; Meshulam-Simon, Galit [Los Altos, CA; McCarty, Perry L [Stanford, CA

    2011-11-22

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  3. Microbial reductive dehalogenation of vinyl chloride

    DOEpatents

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Mannheim, DE; Meshulam-Simon, Galit [Los Angeles, CA; McCarty, Perry L [Stanford, CA

    2014-02-11

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  4. Palladium-catalyzed stereoretentive olefination of unactivated C(sp3)-H bonds with vinyl iodides at room temperature: synthesis of β-vinyl α-amino acids.

    PubMed

    Wang, Bo; Lu, Chengxi; Zhang, Shu-Yu; He, Gang; Nack, William A; Chen, Gong

    2014-12-05

    A method is reported for palladium-catalyzed N-quinolyl carboxamide-directed olefination of the unactivated C(sp(3))-H bonds of phthaloyl alanine with a broad range of vinyl iodides at room temperature. This reaction represents the first example of the stereoretentive installation of multisubstituted terminal and internal olefins onto unactivated C(sp(3))-H bonds. These methods enable access to a wide range of challenging β-vinyl α-amino acid products in a streamlined and controllable fashion, beginning from simple precursors.

  5. Preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  6. Preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-03-24

    This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

  7. Cl⋯N weak interactions. Conformational analysis of imidazol-2-ylum heterocycles bearing N-β-chloroethyl and N-vinyl pendant groups

    NASA Astrophysics Data System (ADS)

    Rodríguez-López, Germán; Montes-Tolentino, Pedro; Sánchez-Ruiz, Sonia; Villaseñor-Granados, Tayde Osvaldo; Flores-Parra, Angelina

    2017-11-01

    Enantiomerically pure and racemic mixtures of β-chloroethylamines hydrochlorides with one and two stereogenic centres were used to synthesise 1,4-dialkyl-1,3-diimines, which in turn gave place to a series of imidazolium chlorides and tetraphenylborates bearing pendant N-β-chloroethyl substituents (sbnd CHEt-CH2Cl; sbnd CHMe-CHPhCl). Stereoselective dehydrochlorination of imidazolium compounds afforded in good yield the corresponding heterocycles bearing N-vinyl groups (-CEt=CH2; -CMe=CHPh). The volume of the N-substituents provides a steric screening of the cationic ring. The structure of the new compounds was determined by IR, mass spectra, NMR and X-ray diffraction analyses as well as DFT calculations of the optimized geometries. Uncommon stabilising intramolecular Cl⋯N weak interactions are described, together with H⋯Cl and H···π hydrogen bonds. The existence of the non-covalent weak intramolecular bonds was deduced from the X-ray diffraction analysis and confirmed by calculations of the electrostatic potential, electronic density distributions and the maps of the Laplacian functions of the electronic density.

  8. 3D polymer gel dosimetry using a 3D (DESS) and a 2D MultiEcho SE (MESE) sequence

    NASA Astrophysics Data System (ADS)

    Maris, Thomas G.; Pappas, Evangelos; Karolemeas, Kostantinos; Papadakis, Antonios E.; Zacharopoulou, Fotini; Papanikolaou, Nickolas; Gourtsoyiannis, Nicholas

    2006-12-01

    The utilization of 3D techniques in Magnetic Resonance Imaging data aquisition and post-processing analysis is a prerequisite especially when modern radiotherapy techniques (conformal RT, IMRT, Stereotactic RT) are to be used. The aim of this work is to compare a 3D Double Echo Steady State (DESS) and a 2D Multiple Echo Spin Echo (MESE) sequence in 3D MRI radiation dosimetry using two different MRI scanners and utilising N-VInylPyrrolidone (VIPAR) based polymer gels.

  9. Effect of the Z- and Macro-R-Group on the Thermal Desulfurization of Polymers Synthesized with Acid/Base "Switchable" Dithiocarbamate RAFT Agents.

    PubMed

    Stace, Sarah J; Fellows, Christopher M; Moad, Graeme; Keddie, Daniel J

    2018-05-11

    Thermolysis is examined as a method for complete desulfurization of reversible addition-fragmentation chain transfer (RAFT)-synthesized polymers prepared with acid/base "switchable" N-methyl-N-pyridyldithiocarbamates [RS 2 CZ or RS 2 CZH + ]. Macro-RAFT agents from more activated monomers (MAMs) (i.e., styrene (St), N-isopropylacrylamide (NIPAm), and methyl methacrylate (MMA)) with RS 2 CZH + and less activated monomers (LAMs) (i.e., vinyl acetate (VAc) and N-vinylpyrolidone (NVP)) with RS 2 CZ are prepared by RAFT polymerization and analyzed by thermogravimetric analysis. In all cases, a mass loss consistent with loss of the end group (ZCS 2 H) is observed at temperatures lower than, and largely discrete from, that required for further degradation of the polymer. The temperatures for end group loss and the new end groups formed are strongly dependent on the identity of the R(P) n and the state of the pyridyl Z group; increasing in the series poly(MMA) < poly(St) ∼ poly(NIPAm) < poly(VAc) ∼ poly(NVP) for S 2 CZ and poly(MMA) < poly(St) ∼ poly(NIPAm) for S 2 CZH + . Clean end group removal is possible for poly(St) and poly(NVP). For poly(NIPAm), the thiocarbonyl chain end is removed, but the end group identity is less certain. For poly(MMA) and poly(VAc), some degradation of the polymer accompanies end group loss under the conditions used and further refinement of the process is required. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Stereoselective Vinylation of Aryl N-(2-Pyridylsulfonyl) Aldimines with 1-Alkenyl-1,1-Heterobimetallic Reagents

    PubMed Central

    Hussain, Nusrah; Hussain, Mahmud M.; Ziauddin, Muhammed; Triyawatanyu, Plengchat; Walsh, Patrick J.

    2011-01-01

    Vinylation of aryl N-(2-pyridylsulfonyl) aldimines with versatile 1-alkenyl-1,1-borozinc heterobimetallic reagents is disclosed. In situ hydroboration of air-stable B(pin)-alkynes followed by chemoselective transmetallation with dimethylzinc and addition to aldimines provides B(pin)-substituted allylic amines in 60–93% yield in a one-pot procedure. The addition step can be followed by either B–C bond oxidation to provide α-amino ketones (71–98% yield) or Suzuki cross-coupling to furnish trisubstituted 2-arylated (E)-allylic amines (51–73% yield). PMID:22085226

  11. Determination of NVP-BEZ235, a dual PI3K and mTOR inhibitor, in human and mouse plasma and in mouse tissue homogenates by reversed-phase high-performance liquid chromatography with fluorescence detection.

    PubMed

    Lin, Fan; Chandrasekaran, Gayathri; de Gooijer, Mark C; Beijnen, Jos H; van Tellingen, Olaf

    2012-07-15

    NVP-BEZ235 is a novel dual inhibitor of PI3K/mTOR and currently undergoing phase I/II clinical trials for advanced solid tumors. We developed a sensitive and selective reversed-phase high-performance liquid chromatographic (HPLC) assay with fluorometric detection for quantification of NVP-BEZ235 in biological matrices. Liquid-liquid extraction with tert-butyl methyl ether was used for sample pre-treatment, yielding a recovery of >84%. Chromatographic separation of NVP-BEZ235 and the internal standard (IS) NVP-BBD130 was achieved on a GraceSmart C-18 column by isocratic elution with a mobile phase which consisted of acetonitrile, methanol, and milliQ water adjusted with acetic acid to pH 3.7 (20:36:44, v/v/v). Fluorescence detection using excitation and emission wavelengths of 270 and 425 nm, respectively, provided a selectivity and sensitivity allowing quantification down to 1 ng/ml in human plasma and linear calibration curves within a range of 1-1000 ng/ml. The assay was validated for human plasma, mouse plasma and a range of tissues. The accuracy, within-day and between-day precision for all matrices, was within the generally accepted 15% range. NVP-BEZ235 was stable for 72 h in pretreated samples in reconstitution mixture (acetonitrile-water (30:70, v/v)), but unstable in mouse tissue homogenates upon repeated freeze-thaw cycles or long term storage (≥24 h) at room temperature. A pilot pharmacokinetic study in mice demonstrated the applicability of this method for pharmacokinetic purposes. Overall, this assay is suitable for the pharmacokinetic studies of NVP-BEZ235 in mice and in human plasma. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Complex Coacervate Core Micelles Containing Poly(vinyl alcohol) Inhibit Ice Recrystallization.

    PubMed

    Sproncken, Christian C M; Surís-Valls, Romà; Cingil, Hande E; Detrembleur, Christophe; Voets, Ilja K

    2018-04-10

    Complex coacervate core micelles (C3Ms) form upon complexation of oppositely charged copolymers. These co-assembled structures are widely investigated as promising building blocks for encapsulation, nanoparticle synthesis, multimodal imaging, and coating technology. Here, the impact on ice growth is investigated of C3Ms containing poly(vinyl alcohol), PVA, which is well known for its high ice recrystallization inhibition (IRI) activity. The PVA-based C3Ms are prepared upon co-assembly of poly(4-vinyl-N-methyl-pyridinium iodide) and poly(vinyl alcohol)-block-poly(acrylic acid). Their formation conditions, size, and performance as ice recrystallization inhibitors are studied. It is found that the C3Ms exhibit IRI activity at PVA monomer concentrations as low as 1 × 10 -3 m. The IRI efficacy of PVA-C3Ms is similar to that of linear PVA and PVA graft polymers, underlining the influence of vinyl alcohol monomer concentration rather than polymer architecture. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are described...

  14. Preparation of Syndiotactic Poly(vinyl alcohol)/Poly(vinyl pivalate/vinyl acetate) Microspheres with Radiopacity Using Suspension Copolymerization and Saponification

    NASA Astrophysics Data System (ADS)

    Seok Lyoo, Won; Wook Cha, Jin; Young Kwak, Kun; Jae Lee, Young; Yong Jeon, Han; Sik Chung, Yong; Kyun Noh, Seok

    2010-06-01

    To prepare Poly(vinyl pivalate/vinyl acetate) [P(VPi/VAc)] microspheres with radiopacity, the suspension copolymerization approach in the presence of aqueous radiopaque nanoparticles was used. After, The P(VPi/VAc) microspheres with radiopacity were saponified in heterogeneous system, and then P(VPi/VAc) microspheres without aggregates were converted to s-PVA/P(VPi/VAc) microspheres of skin/core structure through the heterogeneous surface saponification. Radiopacity of microspheres was confirmed with Computed tomography (CT).

  15. Total synthesis of (+)-batzelladine A and (-)-batzelladine D via [4 + 2]-annulation of vinyl carbodiimides with N-alkyl imines.

    PubMed

    Arnold, Michael A; Day, Kenneth A; Durón, Sergio G; Gin, David Y

    2006-10-11

    A diastereoselective [4 + 2]-annulation of vinyl carbodiimides with chiral N-alkyl imines has been developed to access the stereochemically rich polycyclic guanidine cores of the batzelladine alkaloids. Application of this strategy, together with additional key steps such as long-range directed hydrogenation and diastereoselective intramolecular iodo-amination, led to highly convergent total syntheses of (-)-batzelladine D and (+)-batzelladine A with excellent stereocontrol.

  16. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... polymerization of vinyl fluoride. (b) The poly(vinyl fluoride) basic resins have an intrinsic viscosity of not... Dilute Solution Viscosity of Vinyl Chloride Polymers,” which is incorporated by reference. Copies may be... Solution Viscosity of Vinyl Chloride Polymers,” which is incorporated by reference; see paragraph (b) of...

  17. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polymerization of vinyl fluoride. (b) The poly(vinyl fluoride) basic resins have an intrinsic viscosity of not... Dilute Solution Viscosity of Vinyl Chloride Polymers,” which is incorporated by reference. Copies may be... Solution Viscosity of Vinyl Chloride Polymers,” which is incorporated by reference; see paragraph (b) of...

  18. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride... the purpose of this section, poly(vinyl fluoride) resins consist of basic resins produced by the...

  19. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride... the purpose of this section, poly(vinyl fluoride) resins consist of basic resins produced by the...

  20. MECHANICAL PROPERTIES OF BLENDS OF PAMAM DENDRIMERS WITH POLY(VINYL CHLORIDE) AND POLY(VINYL ACETATE)

    EPA Science Inventory

    Hybrid blends of poly(amidoamine) PAMAM dendrimers with two linear high polymers, poly(vinyl chloride), PVC, and poly(vinyl acetate), PVAc, are reported. The interaction between the blend components was studied using dynamic mechanical analysis, xenon nuclear magnetic resonacne ...

  1. Indirect latex glove contamination and its inhibitory effect on vinyl polysiloxane polymerization.

    PubMed

    Kimoto, Katsuhiko; Tanaka, Kinya; Toyoda, Minoru; Ochiai, Kent T

    2005-05-01

    The inhibitory effect of indirect latex contamination on the polymerization of vinyl polysiloxane (VPS) impression material has been previously reported. However, the transfer of specific elements that cause inhibition has not been confirmed, nor has the removal of such contaminants been reported. This study examined the surfaces of materials commonly used in restorative procedures that were contaminated by indirect latex glove contact and then evaluated for inhibition of polymerization of VPS. The effect of selected cleansing procedures was then studied. Four experimental groups (n = 8) were prepared: (1) clean vinyl gloves (control), (2) clean gingival retraction cords (control), (3) contaminated vinyl gloves, and (4) contaminated gingival retraction cord. Microscopic evaluation of the appearance and the characterization of surface particulate contamination were performed for each. Three cleansing protocols were then evaluated for efficacy in cleaning vinyl glove surfaces contaminated by latex contact (n = 10): (1) brushing with water, (2) brushing with soap/rinsing with water, (3) cleansing with rubbing alcohol. The subsequent degree of VPS polymerization inhibition was evaluated subjectively. A chi-square test was used for data analysis (alpha=.05). Particulate sulfur elements and sulfur-chloride compounds were present on the contaminated substrates. None of the 3 cleansing procedures eliminated polymerization inhibition (P =.33). Residual elemental sulfur remained on all tested surfaces. Particulate sulfur and sulfur-chloride compounds were identified as the particulate contamination that resulted in polymerization inhibition of the tested VPS dental impression material. Removal of these contaminants from the tested vinyl gloves and gingival retraction cord was not possible with the 3 cleansing protocols tested in this study.

  2. Vinyl flooring in the home is associated with children's airborne butylbenzyl phthalate and urinary metabolite concentrations.

    PubMed

    Just, Allan C; Miller, Rachel L; Perzanowski, Matthew S; Rundle, Andrew G; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E; Calafat, Antonia M; Perera, Frederica P; Whyatt, Robin M

    2015-01-01

    Prior studies have shown that vinyl flooring as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) are associated with asthma and airway inflammation. Although DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (i) visual observation of potential phthalate containing flooring, (ii) a 2-week home indoor air sample, and (iii) concurrent urinary metabolites in a subset (n=193). The category "vinyl or linoleum" flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m(3)) than rooms with wood or carpet flooring (10.6 ng/m(3)). Children from homes with "vinyl or linoleum" flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman's rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children's exposure to BBzP via indoor air.

  3. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  4. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  5. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  6. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  7. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  8. Effects of cyclic structure inhibitors on the morphology and growth of tetrahydrofuran hydrate crystals

    NASA Astrophysics Data System (ADS)

    Li, Sijia; Wang, Yanhong; Lang, Xuemei; Fan, Shuanshi

    2013-08-01

    Morphology and growth of hydrate crystals with cyclic structure inhibitors at a hydrate-liquid interface were directly observed through a microscopic manipulating apparatus. Tetrahydrofuran (THF) hydrate was employed as an objective. The effects of four kind of cyclic structure inhibitors, polyvinylpyrrolidone (PVP), poly(N-vinyl-2-pyrrolidone-co-2-vinyl pyridine) (PVPP), poly(2-vinyl pyridine-co-N-vinylcaprolactam) (PVPC) and poly(N-vinylcaprolactam) (PVCap), were investigated. Morphological patterns between each hydrate crystal growth from hydrate-liquid interface into droplet were found differ significantly. Lamellar structure growth of hydrate crystal was observed without inhibitor, while with PVP was featheriness-like, PVPP was like long dendritic crystal, PVPC was Mimosa pudica leaf-like and PVCap was like weeds. The growth rate of hydrate crystal without inhibitor was 0.00498 mm3/s, while with PVPP, PVPC and PVCap, were 0.00339 mm3/s, 0.00350 mm3/s, 0.00386 mm3/s and 0.00426 mm3/s, respectively. Cyclic structure inhibitors can decrease the growth rate, degree of reduction in growth rate of hydrate crystals decrease with the increase of cylinder number.

  9. Polymeric blend nanocomposite membranes for ethanol dehydration-effect of morphology and membrane-solvent interactions

    EPA Science Inventory

    Nanocomposite membranes (NCMs) of sodium alginate/poly(vinyl pyrrolidone) blend polymers incorporated with varying concentrations of phosphotungstic acid (H3PW12O40) (PWA) nanoparticles have been prepared and used in ethanol dehydration by the pervaporation (PV) technique. Effe...

  10. Antimicrobial fabric adsorbed iodine produced by radiation-induced graft polymerization

    NASA Astrophysics Data System (ADS)

    Aoki, Shoji; Fujiwara, Kunio; Sugo, Takanobu; Suzuki, Koichi

    2013-03-01

    Antimicrobial fabric was synthesized by radiation-induced graft polymerization of N-vinyl pyrrolidone onto polyolefine nonwoven fabric and subsequent adsorption of iodine. In response of the huge request for the antimicrobial material applied to face masks for swine flu in 2009, operation procedure of continuous radiation-induced graft polymerization apparatus was improved. The improved grafting production per week increased 3.8 times compared to the production by former operation procedure. Shipped antimicrobial fabric had reached 130,000 m2 from June until December, 2009.

  11. Total Synthesis of (+)-Batzelladine A and (−)-Batzelladine D via [4 + 2]-Annulation of Vinyl Carbodiimides with N-Alkyl Imines

    PubMed Central

    Arnold, Michael A.; Day, Kenneth A.; Durón, Sergio G.; Gin, David Y.

    2008-01-01

    A diastereoselective [4 + 2]-annulation of vinyl carbodiimides with chiral N-alkyl imines has been developed to access the stereochemically rich polycyclic guanidine cores of the batzelladine alkaloids. Application of this strategy, together with additional key steps such as long-range directed hydrogenation and diastereoselective intramolecular iodo-amination, led to highly convergent total syntheses of (−)-batzelladine D and (+)-batzelladine A with excellent stereocontrol. PMID:17017806

  12. Vinyl flooring in the home is associated with children’s airborne butylbenzyl phthalate and urinary metabolite concentrations

    PubMed Central

    Just, Allan C.; Miller, Rachel L.; Perzanowski, Matthew S.; Rundle, Andrew G.; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E.; Calafat, Antonia M.; Perera, Frederica P.; Whyatt, Robin M.

    2015-01-01

    Prior studies have shown that vinyl flooring, as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP), are associated with asthma and airway inflammation. While DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (1) visual observation of potential phthalate containing flooring, (2) a two-week home indoor air sample, and (3) concurrent urinary metabolites in a subset (n=193). The category “vinyl or linoleum” flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m3) than rooms with wood or carpet flooring (10.6 ng/m3). Children from homes with “vinyl or linoleum” flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman’s rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children’s exposure to BBzP via indoor air. PMID:25690585

  13. 46 CFR 154.1745 - Vinyl chloride: Transferring operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride: Transferring operations. 154.1745 Section 154.1745 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Operating Requirements § 154.1745 Vinyl chloride: Transferring operations. A vessel carrying vinyl chloride...

  14. Pure Rotational Spectroscopy of Vinyl Mercaptan

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, Marie-Aline; Zingsheim, Oliver; Thorwirth, Sven; Müller, Holger S. P.; Lewen, Frank; Schlemmer, Stephan

    2014-06-01

    Vinyl mercaptan (ethenethiol, CH_2=CHSH) exists in the gas phase in two distinct rotameric forms, syn (planar) and anti (quasi-planar in the ground vibrational state). The microwave spectra of these two isomers were investigated previously, however not exceeding frequencies of about 65 GHz. In the present investigation, the pure rotational spectra of both species have been investigated at millimeter wavelengths. Vinyl mercaptan was produced in a radiofrequency discharge through a constant flow of ethanedithiol at low pressure. Both syn and anti rotamers were observed and new extensive sets of molecular parameters were obtained. Owing to its close structural relationship to vinyl alcohol and the astronomical abundance of complex sulfur-bearing molecules, vinyl mercaptan is a plausible candidate for future radio astronomical searches. M. Tanimoto et al. J. Mol. Spectrosc. 78, 95--105 & 106--119 (1979)

  15. Graphene-Fiber-Based Supercapacitors Favor N-Methyl-2-pyrrolidone/Ethyl Acetate as the Spinning Solvent/Coagulant Combination.

    PubMed

    He, Nanfei; Pan, Qin; Liu, Yixin; Gao, Wei

    2017-07-26

    One-dimensional flexible fiber supercapacitors (FSCs) have attracted great interest as promising energy-storage units that can be seamlessly incorporated into textiles via weaving, knitting, or braiding. The major challenges in this field are to develop tougher and more efficient FSCs with a relatively easy and scalable process. Here, we demonstrate a wet-spinning process to produce graphene oxide (GO) fibers from GO dispersions in N-methyl-2-pyrrolidone (NMP), with ethyl acetate as the coagulant. Upon chemical reduction of GO, the resulting NMP-based reduced GO (rGO) fibers (rGO@NMP-Fs) are twice as high in the surface area and toughness but comparable in tensile strength and conductivity as that of the water-based rGO fibers (rGO@H 2 O-Fs). When assembled into parallel FSCs, rGO@NMP-F-based supercapacitors (rGO@NMP-FSCs) offered a specific capacitance of 196.7 F cm -3 (147.5 mF cm -2 ), five times higher than that of rGO@H 2 O-F-based supercapacitors (rGO@H 2 O-FSCs) and also higher than most existing wet-spun rGO-FSCs, as well as those FSCs built with metal wires, graphene/carbon nanotube (CNT) fibers, or even pseudocapacitive materials. In addition, our rGO@NMP-FSCs can provide good bending and cycling stability. The energy density of our rGO@NMP-FSCs reaches ca. 6.8 mWh cm -3 , comparable to that of a Li thin-film battery (4 V/500 μAh).

  16. Formation of silicon carbide by laser ablation in graphene oxide-N-methyl-2-pyrrolidone suspension on silicon surface

    NASA Astrophysics Data System (ADS)

    Jaleh, Babak; Ghasemi, Samaneh; Torkamany, Mohammad Javad; Salehzadeh, Sadegh; Maleki, Farahnaz

    2018-01-01

    Laser ablation of a silicon wafer in graphene oxide-N-methyl-2-pyrrolidone (GO-NMP) suspension was carried out with a pulsed Nd:YAG laser (pulse duration = 250 ns, wavelength = 1064 nm). The surface of silicon wafer before and after laser ablation was studied using optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The results showed that the ablation of silicon surface in liquid by pulsed laser was done by the process of melt expulsion under the influence of the confined plasma-induced pressure or shock wave trapped between the silicon wafer and the liquid. The X-ray diffraction‌ (XRD) pattern of Si wafer after laser ablation showed that 4H-SiC layer is formed on its surface. The formation of the above layer was also confirmed by Raman spectroscopy, and X-ray photoelectron spectroscopy‌ (XPS), as well as EDX was utilized. The reflectance of samples decreased with increasing pulse energy. Therefore, the morphological alteration and the formation of SiC layer at high energy increase absorption intensity in the UV‌-vis regions. Theoretical calculations confirm that the formation of silicon carbide from graphene oxide and silicon wafer is considerably endothermic. Development of new methods for increasing the reflectance without causing harmful effects is still an important issue for crystalline Si solar cells. By using the method described in this paper, the optical properties of solar cells can be improved.

  17. 21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of articles...

  18. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...(vinyl fluoride) basic resins have an intrinsic viscosity of not less than 0.75 deciliter per gram as determined by ASTM method D1243-79, “Standard Test Method for Dilute Solution Viscosity of Vinyl Chloride... (ASTM method D1243-79, “Standard Test Method for Dilute Solution Viscosity of Vinyl Chloride Polymers...

  19. Method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, Jr., Earle D.

    1995-01-01

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member and/or six member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone.

  20. 29 CFR 1915.1017 - Vinyl chloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Vinyl chloride. 1915.1017 Section 1915.1017 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1017 Vinyl chloride. Note: The requirements applicable to shipyard employment under this section...

  1. Vinyl acetate

    Integrated Risk Information System (IRIS)

    Vinyl acetate ; CASRN 108 - 05 - 4 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 Eff

  2. Vinyl chloride

    Integrated Risk Information System (IRIS)

    EPA / 635R - 00 / 004 TOXICOLOGICAL REVIEW OF VINYL CHLORIDE ( CAS No . 75 - 01 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) May 2000 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accordance w

  3. Vinyl bromide

    Integrated Risk Information System (IRIS)

    Vinyl bromide ; CASRN 593 - 60 - 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 Assessments for Noncarcinogenic Eff

  4. Thermodynamic properties (enthalpy, bond energy, entropy, and heat capacity) and internal rotor potentials of vinyl alcohol, methyl vinyl ether, and their corresponding radicals.

    PubMed

    da Silva, Gabriel; Kim, Chol-Han; Bozzelli, Joseph W

    2006-06-29

    Vinyl alcohols (enols) have been discovered as important intermediates and products in the oxidation and combustion of hydrocarbons, while methyl vinyl ethers are also thought to occur as important combustion intermediates. Vinyl alcohol has been detected in interstellar media, while poly(vinyl alcohol) and poly(methyl vinyl ether) are common polymers. The thermochemical property data on these vinyl alcohols and methyl vinyl ethers is important for understanding their stability, reaction paths, and kinetics in atmospheric and thermal hydrocarbon-oxygen systems. Enthalpies , entropies , and heat capacities (C(p)()(T)) are determined for CH(2)=CHOH, C(*)H=CHOH, CH(2)=C(*)OH, CH(2)=CHOCH(3), C(*)H=CHOCH(3), CH(2)=C(*)OCH(3), and CH(2)=CHOC(*)H(2). Molecular structures, vibrational frequencies, , and C(p)(T) are calculated at the B3LYP/6-31G(d,p) density functional calculation level. Enthalpies are also determined using the composite CBS-Q, CBS-APNO, and G3 methods using isodesmic work reactions to minimize calculation errors. Potential barriers for internal rotors are calculated at the B3LYP/6-31G(d,p) level and used to determine the hindered internal rotational contributions to entropy and heat capacity. The recommended ideal gas phase values calculated in this study are the following (in kcal mol(-1)): -30.0, -28.9 (syn, anti) for CH(2)=CHOH; -25.6, -23.9 for CH(2)=CHOCH(3); 31.3, 33.5 for C(*)H=CHOH; 27.1 for anti-CH(2)=C(*)OH; 35.6, 39.3 for C(*)H=CHOCH(3); 33.5, 32.2 for CH(2)=C(*)OCH(3); 21.3, 22.0 for CH(2)=CHOC(*)H(2). Bond dissociation energies (BDEs) and group additivity contributions are also determined. The BDEs reveal that the O-H, O-CH(3), C-OH, and C-OCH(3) bonds in vinyl alcohol and methyl vinyl ether are similar in energy to those in the aromatic molecules phenol and methyl phenyl ether, being on average around 3 kcal mol(-1) weaker in the vinyl systems. The keto-enol tautomerization enthalpy for the interconversion of vinyl alcohol to acetaldehyde is

  5. Compound oxidized styrylphosphine. [flame resistant vinyl polymers

    NASA Technical Reports Server (NTRS)

    Paciorek, K. J. L. (Inventor)

    1979-01-01

    A process is described for preparing flame resistant, nontoxic vinyl polymers which contain phosphazene groups and which do not emit any toxic or corrosive products when they are oxidatively degraded. Homopolymers, copolymers, and terpolymers of a styrene based monomer are prepared by polymerizing at least one oxidized styrylphosphine monomer from a group of organic azides, or by polymerizing p-diphenylphosphinestyrene and then oxidizing that monomer with an organoazide from the group of (C6H5)2P(O)N3, (C6H5O)2P(O)N3, (C6H5)2C3N3(N3), and C6H5C3N3(N3)2. Copolymers can also be prepared by copolymerizing styrene with at least one oxidized styrylphosphine monomer.

  6. First application of an efficient and versatile ligand for copper-catalyzed cross-coupling reactions of vinyl halides with N-heterocycles and phenols.

    PubMed

    Kabir, M Shahjahan; Lorenz, Michael; Namjoshi, Ojas A; Cook, James M

    2010-02-05

    2-Pyridin-2-yl-1H-benzoimidazole L3 is presented as a new, efficient, and versatile bidentate N-donor ligand suitable for the copper-catalyzed formation of vinyl C-N and C-O bonds. This inexpensive and easily prepared ligand facilitates copper-catalyzed cross-coupling reactions of alkenyl bromides and iodides with N-heterocycles and phenols to afford the desired cross-coupled products in good to excellent yields with full retention of stereochemistry. This method is particularly noteworthy given its efficiency, that is, mild reaction conditions, low catalyst loading, simplicity, versatility, and exceptional level of functional group tolerance.

  7. First Application of An Efficient and Versatile Ligand for Copper-Catalyzed Cross-Coupling Reactions of Vinyl Halides with N-Heterocycles and Phenols

    PubMed Central

    Kabir, M. Shahjahan; Lorenz, Michael; Namjoshi, Ojas A.; Cook, James M.

    2010-01-01

    2-Pyridin-2-yl-1H-benzoimidazole L3 is presented as a new, efficient, and versatile bidentate N-donor ligand suitable for the copper-catalyzed formation of vinyl C-N and C-O bonds. This inexpensive and easily prepared ligand facilitates copper-catalyzed cross-coupling reactions of alkenyl bromides and iodides with N-heterocycles and phenols to afford the desired cross-coupled products in good to excellent yields with full retention of stereochemistry. This method is particularly noteworthy given its efficiency i.e., mild reaction conditions, low catalyst loading, simplicity, versatility, and exceptional level of functional group tolerance. PMID:20039699

  8. IRIS Toxicological Review of Vinyl Chloride (Final Report ...

    EPA Pesticide Factsheets

    EPA is announcing the release of the final report, Toxicological Review of Vinyl Chloride: in support of the Integrated Risk Information System (IRIS). The updated Summary for Vinyl Chloride and accompanying Quickview have also been added to the IRIS Database. Common synonyms of vinyl chloride (VC) include chloroethene, chloroethylene, ethylene monochloride, and monochloroethene. VC is a synthetic chemical used as a chemical intermediate in the polymerization of polyvinyl chloride.

  9. 40 CFR 721.10262 - Oxime, Me vinyl silane (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxime, Me vinyl silane (generic). 721... Substances § 721.10262 Oxime, Me vinyl silane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as oxime, Me vinyl silane (PMN P...

  10. 40 CFR 721.10262 - Oxime, Me vinyl silane (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Oxime, Me vinyl silane (generic). 721... Substances § 721.10262 Oxime, Me vinyl silane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as oxime, Me vinyl silane (PMN P...

  11. 21 CFR 177.1960 - Vinyl chloride-hexene-1 copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-hexene-1 copolymers. 177.1960... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1960 Vinyl chloride-hexene-1 copolymers. The vinyl chloride-hexene-1 copolymers identified in paragraph (a) of this section or as...

  12. 46 CFR 154.1740 - Vinyl chloride: Inhibiting and inerting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride: Inhibiting and inerting. 154.1740... Operating Requirements § 154.1740 Vinyl chloride: Inhibiting and inerting. When a vessel is carrying vinyl chloride, the master shall ensure that: (a) Section 154.1818 is met; or (b) Section 154.1710 is met, and...

  13. Design and synthesis study of the thermo-sensitive poly (N-vinylpyrrolidone-b- N, N-diethylacrylamide).

    PubMed

    Zhang, Xiayun; Yang, Zhongduo; Xie, Dengmin; Liu, Donglei; Chen, Zhenbin; Li, Ke; Li, Zhizhong; Tichnell, Brandon; Liu, Zhen

    2018-01-01

    The reversible addition fragmentation chain transfer (RAFT) polymerization method was adopted here to prepare a series of thermo-sensitive copolymers, poly (N,N-diethyl- acrylamide-b-N-vinylpyrrolidone). Their structures, molecular weight distribution and temperature sensitivity performances were characterized by the nuclear magnetic resonance ( 1 HNMR), the gel permeation chromatography (GPC) and the fluorescence spectrophotometer, respectively. It has been identified that the synthesis reaction of the block copolymer was living polymerization. The thermo-sensitivity study suggested that N-vinylpyrrolidone (NVP), played a key role on the lower critical solution temperature (LCST) performance.

  14. Viscometric investigation of compatibilization of the poly(vinyl chloride)/poly(ethylene-co-vinyl acetate) blends by terpolymer of maleic anhydride styrene vinyl acetate

    NASA Astrophysics Data System (ADS)

    İmren, Dilek; Boztuğ, Ali; Yılmaz, Ersen; Zengin, H. Bayram

    2008-11-01

    In this study, a blend of poly(vinyl chloride) (PVC)/ethylene-co-vinyl acetate (EVA) was compatibilized by terpolymer of maleic anhydride-styrene-vinyl acetate (MAStVA) used as a compatibilizer. It was prepared the blends of 50/50 PVC/EVA containing 2-10% of the terpolymer. The compatibility experiences of these blends were investigated by using viscometric method in the range of concentrations (0.5-2.0 g dL -1) where tetrahydrofuran (THF) is the solvent. The interaction parameter (Δ b) was used to study the miscibility and compatibility of polymer blend in solution, obtained from the modified Krigbaum and Wall theory. Turbidity and FTIR measurements were also used to investigate the miscibility of this pair of polymers. The values of the relative viscosities of the each polymer solution and their blends were measured by a Cannon-Fenske type viscometer. In consequence of the study, it was observed that a considerable improvement was achieved in the miscibility of PVC/EVA blends by adding among 5 and 10 wt% of compatibilizer.

  15. Spectroscopic detection and mapping of vinyl cyanide on Titan

    NASA Astrophysics Data System (ADS)

    Cordiner, Martin; Yukiko Palmer, Maureen; Lai, James; Nixon, Conor A.; Teanby, Nicholas; Charnley, Steven B.; Vuitton, Veronique; Kisiel, Zbigniew; Irwin, Patrick; Molter, Ned; Mumma, Michael J.

    2017-10-01

    The first spectroscopic detection of vinyl cyanide (otherwise known as acrylonitrile; C2H3CN) on Titan was obtained by Palmer et al. (2017), based on three rotational emission lines observed with ALMA at millimeter wavelengths (in receiver band 6). The astrobiological significance of this detection was highlighted due to the theorized ability of C2H3CN molecules to combine into cell membrane-like structures under the cold conditions found in Titan's hydrocarbon lakes. Here we report the detection of three additional C2H3CN transitions at higher frequencies (from ALMA band 7 flux calibration data). We present the first emission maps for this gas on Titan, and compare the molecular distribution with that of other nitriles observed with ALMA including HC3N, CH3CN, C2H5CN and HNC. The molecular abundance patterns are interpreted based on our understanding of Titan's high-altitude photochemistry and time-variable global circulation. Similar to the short-lived HC3N molecule, vinyl cyanide is found to be most abundant in the vicinity of the southern (winter) pole, whereas the longer-lived CH3CN is more concentrated in the north. The vertical abundance profile of C2H3CN (from radiative transfer modeling), as well as its latitudinal distribution, are consistent with a short photochemical lifetime for this species. Complementary results from our more recent (2017) nitrile mapping studies at higher spatial resolution will also be discussed.REFERENCES:Palmer, M. Y., Cordiner, M. A., Nixon, C. A. et al. "ALMA detection and astrobiological potential of vinyl cyanide on Titan", Sci. Adv. 2017, 3, e1700022

  16. Synthesis and patterning of polymers for biomedical applications

    NASA Astrophysics Data System (ADS)

    He, Wei

    The goal of this dissertation is to synthesize and characterize novel polymers, as well as to explore alternative techniques for biomedical applications. Although significant progress has been achieved in the design and preparation of new biomaterials over the past years, much remains to be accomplished. The interactions between biomaterials and cells are very important, especially in the emerging field of tissue engineering. The focus of this research is to improve such interactions via several different approaches. One way to engineer cellular interaction is by modifying surface topography through micro-patterning. Although photolithography is widely used for patterning, it is not suitable for direct cell and protein patterning because of the usage of organic solvent for feature development. To address this issue, a biocompatible chemically amplified resist derived from N-vinyl-2-pyrrolidone (NVP) was prepared. The results have shown that no organic solvent development was required to reveal the patterns and cells can be cultured on these patterned surfaces directly. Strong cell alignment was observed. The other issue addressed in this research is to develop a technique that can modify surface morphology and surface chemistry simultaneously. Such a technique is called masked ion beam lithography (MIBL). By implanting phosphorous ions on polymeric substrates through masks, not only micron/nano size patterns were generated on the surface, but also the phosphorous ions were incorporated. Incubation of bone forming osteoblast cells on these ion beam processed samples has shown that osteoblast cell attachment to the substrate was enhanced, as a consequence of the increased surface roughness as well as the implanted phosphorous ions. This indicates that MIBL can not only generate micro/nanostructures on the surface of a biocompatible polymer, but can also selectively modify the surface chemistry by implanting with specific ions. These factors can contribute to an

  17. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

  18. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

  19. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

  20. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

  1. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids any...

  2. Vinyl monomers-induced synthesis of polyvinyl alcohol-stabilized selenium nanoparticles

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

    Shah, Chetan P.; Singh, Krishan K.; Kumar, Manmohan, E-mail: manmoku@barc.gov.in

    2010-01-15

    A simple wet chemical method has been developed to synthesize selenium nanoparticles (size 100-200 nm), by reaction of sodium selenosulphate precursor with different vinyl monomers, such as acrylamide, N,N'-dimethylene bis acrylamide, methyl methacrylate, sodium acrylate, etc., in aqueous medium, under ambient conditions. Polyvinyl alcohol has been used to stabilize the selenium nanoparticles. Average size of the synthesized selenium nanoparticles can be controlled by adjusting concentration of both the precursors and the stabilizer. Rate of the reaction as well as size of the resultant selenium nanoparticles have been correlated with the functional groups of the different monomers. UV-vis optical absorption spectroscopy,more » X-ray diffraction, energy dispersive X-rays, differential scanning calorimetry, atomic force microscopy, scanning electron microscopy and transmission electron microscopy techniques have been employed to characterize the synthesized selenium nanoparticles. Gas chromatographic analysis of the reaction mixture established the non-catalytic role of the vinyl monomers, which were found to be consumed during the course of the reaction.« less

  3. Pyrrolidone - a new solvent for the methylation of humic acid

    USGS Publications Warehouse

    Wershaw, R. L.; Pinckney, D.J.; Booker, S.E.

    1975-01-01

    In the past, humic acid has been methylated by suspending it in a solution of diazomethane in diethyl ether, and degrading the partly methylated humic acid to release those parts of the molecule that were methylated. Only small fragments of the molecule have been identified by this technique. In the procedure described here the humic acid is dissolved in 2-pyrrolidone and methylated by the addition of diazomethane in diethyl ether and ethanol to the solution. Because the humic acid is completely dissolved in the reaction medium, disaggregation of the humic acid particles takes place and much more complete methylation is obtained. The methylated products may be fractionated by countercurrent distribution and analyzed by mass spectrometry.

  4. Degradable vinyl polymers for biomedical applications.

    PubMed

    Delplace, Vianney; Nicolas, Julien

    2015-10-01

    Vinyl polymers have been the focus of intensive research over the past few decades and are attractive materials owing to their ease of synthesis and their broad diversity of architectures, compositions and functionalities. Their carbon-carbon backbones are extremely resistant to degradation, however, and this property limits their uses. Degradable polymers are an important field of research in polymer science and have been used in a wide range of applications spanning from (nano)medicine to microelectronics and environmental protection. The development of synthetic strategies to enable complete or partial degradation of vinyl polymers is, therefore, of great importance because it will offer new opportunities for the application of these materials. This Review captures the most recent and promising approaches to the design of degradable vinyl polymers and discusses the potential of these materials for biomedical applications.

  5. Poly (N-vinyl Carbazole) - Polypyrrole/graphene oxide nanocomposite material on tapered fiber for Q-switched pulse generation

    NASA Astrophysics Data System (ADS)

    Ahmad, H.; Faruki, M. J.; Jasim, A. A.; Ooi, S. I.; Thambiratnam, K.

    2018-02-01

    A passively Q-switched fiber laser using a Saturable Absorber (SA) fabricated from a new Poly (N-vinyl Carbazole) - Polypyrrole/Graphene Oxide (PNVC-PPy/GO) nanocomposite material deposited on a tapered fiber is proposed and demonstrated. The PNVC-PPy/GO composition is deposited along a 3 mm length of the 6.5 cm tapered fiber which has a tapered waist of 8 μm. Q-switched pulses are obtained with repetition rates of 25.15-42.7 kHz and pulse widths of 5.74-2.48 μs over a pump power range of 12.8-40.0 mW. A maximum average power of 0.19 mW and pulse energy of 4.43 nJ are also observed. The proposed Q-switched maintains advantages of a simple design and low fabrication cost while at the same time generating high quality Q-switched pulses.

  6. Surveillance for angiosarcoma of the liver among vinyl chloride workers.

    PubMed

    Collins, James J; Jammer, Brenda; Sladeczek, Frank M; Bodnar, Catherine M; Salomon, Sergio S

    2014-11-01

    We report the results of our angiosarcoma of the liver (ASL) registry to assess the occurrence, the impact of exposures to vinyl chloride, and to quantify latency. We examined more than 73,000 death certificates of North American workers employed between 1940 and 2008. We found 13 deaths of ASL among workers with vinyl chloride exposure. All 13 occurred at single plant among workers with high vinyl chloride exposure. The mean latency after first exposure was 36.5 years ranging from 24 to 56 years. No ASL deaths occurred among workers with vinyl chloride exposures after 1974, when exposures were reduced. We may have seen the last case of ASL among workers exposed to vinyl chloride. Nevertheless, given the long latency of this cancer, continued surveillance seems prudent.

  7. Anaerobic mineralization of vinyl chloride in Fe(III)-reducing, aquifer sediments

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.

    1996-01-01

    Within anaerobic aquifer systems, reductive dehalogenation of polychlorinated ethenes commonly results in the accumulation of vinyl chloride, which is highly toxic and carcinogenic to humans. Anaerobic reduction of vinyl chloride is considered to be slow and incomplete. Here, we provide the first evidence for anaerobic oxidation of vinyl chloride under Fe(III)reducing conditions. Addition of chelated Fe(III) (as Fe-EDTA) to anaerobic aquifer microcosms resulted in mineralization of up to 34% of [1,2- 14C]vinyl chloride within 84 h. The results indicate that vinyl chloride can be mineralized under anaerobic, Fe(III)-reducing conditions and that the bioavailability of Fe(III) is an important factor affecting the rates of mineralization.

  8. Production of methyl-vinyl ketone from levulinic acid

    DOEpatents

    Dumesic, James A [Verona, WI; West,; Ryan, M [Madison, WI

    2011-06-14

    A method for converting levulinic acid to methyl vinyl ketone is described. The method includes the steps of reacting an aqueous solution of levulinic acid, over an acid catalyst, at a temperature of from room temperature to about 1100 K. Methyl vinyl ketone is thereby formed.

  9. Far-Infrared Spectroscopy of Syn-Vinyl Alcohol

    NASA Astrophysics Data System (ADS)

    Raston, Paul; Bunn, Hayley

    2016-06-01

    Vinyl alcohol has been extensively studied in both the microwave and mid-IR spectral regions, where 9 out of 15 vibrational modes have been identified. Here we present the first far-IR spectrum of vinyl alcohol, collected below 700 wn at the Australian Synchrotron. The high resolution (0.001 wn) spectrum reveals the νb{11} and νb{15} fundamentals of syn-vinyl alcohol at 489 wn and 407 wn, in addition to two hot bands of the νb{15} mode at 369 wn and 323 wn. High J transitions in the R-branch of the νb{15} band were found to be perturbed by an a-axis Coriolis interaction with the nearby νb{11} state. The νb{15} torsional mode of syn-vinyl alcohol was fit using a Watson's A-reduced Hamiltonian to yield rotational, centrifugal distortion, and Coriolis coupling parameters. S. Saito, Chem. Phys. Lett. 42, 3 (1976) M. Rodler et al., J. Am. Chem. Soc. 106, 4029 (1948) Y. Koga et al., J. Mol. Spec. 145, 315 (1991) D-L. Joo et al., J. Mol. Spec. 197, 68 (1999)

  10. High-strength N-methyl-2-pyrrolidone-containing process wastewater treatment using sequencing batch reactor and membrane bioreactor: A feasibility study.

    PubMed

    Loh, Chun Heng; Wu, Bing; Ge, Liya; Pan, Chaozhi; Wang, Rong

    2018-03-01

    N-methyl-2-pyrrolidone (NMP) is widely used as a solvent in polymeric membrane fabrication process, its elimination from the process wastewater (normally at a high concentration > 1000 mg/L) prior to discharge is essential because of environmental concern. This study investigated the feasibility of treating high-strength NMP-containing process wastewater in a sequencing batch reactor (SBR; i.e., batch feeding and intermittent aerobic/anoxic condition) and a membrane bioreactor (MBR; i.e., continuous feeding and aeration), respectively. The results showed that the SBR with the acclimated sludge was capable of removing >90% of dissolved organic carbon (DOC) and almost 98% of NMP within 2 h. In contrast, the MBR with the acclimated sludge showed a decreasing NMP removal efficiency from 100% to 40% over 15-day operation. The HPLC and LC-MS/MS analytical results showed that NMP degradation in SBR and MBR could undergo different pathways. This may be attributed to the dissimilar bacterial community compositions in the SBR and MBR as identified by 16s rRNA gene sequencing analysis. Interestingly, the NMP-degrading capability of the activated sludge derived from MBR could be recovered to >98% after they were operated at the SBR mode (batch feeding mode with intermittent aerobic/anoxic condition). This study reveals that SBR is probably a more feasible process to treat high-strength NMP-containing wastewater, but residual NMP metabolites in the SBR effluent need to be post-treated by an oxidation or adsorption process in order to achieve zero-discharge of toxic chemicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Separation of copper ions from iron ions using PVA-g-(acrylic acid/N-vinyl imidazole) membranes prepared by radiation-induced grafting.

    PubMed

    Ajji, Zaki; Ali, Ali M

    2010-01-15

    Acrylic acid (AAc), N-vinyl imidazole (Azol) and their binary mixtures were graft copolymerized onto poly(vinyl alcohol) membranes using gamma irradiation. The ability of the grafted membranes to separate Cu ions from Fe ions was investigated with respect to the grafting yield and the pH of the feed solution. The data showed that the diffusion of copper ions from the feed compartment to the receiver compartment depends on the grafting yield of the membranes and the pH of the feed solution. To the contrary, iron ions did not diffuse through the membranes of all grafting yields. However, a limited amount of iron ions diffused in strong acidic medium. This study shows that the prepared membranes could be considered for the separation of copper ions from iron ions. The temperature of thermal decomposition of pure PVA-g-AAc/Azol membrane, PVA-g-AAc/Azol membrane containing copper ions, and PVA-g-AAc/Azol membrane containing iron ions were determined using TGA analyzer. It was shown that the presence of Cu and Fe ions increases the decomposition temperature, and the membranes bonded with iron ions are more stable than those containing copper ions.

  12. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... be used as a “check” on the required closed gauge, nor as a means or sampling. (h) The words “CANCER... legend: cancer—suspect agent in this area protective equipment required authorized personnel only must be... clean and dry for each use, to prevent skin contact with liquid vinyl chloride. [CGFR 70-10, 35 FR 3714...

  13. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... be used as a “check” on the required closed gauge, nor as a means or sampling. (h) The words “CANCER... legend: cancer—suspect agent in this area protective equipment required authorized personnel only must be... clean and dry for each use, to prevent skin contact with liquid vinyl chloride. [CGFR 70-10, 35 FR 3714...

  14. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... be used as a “check” on the required closed gauge, nor as a means or sampling. (h) The words “CANCER... legend: cancer—suspect agent in this area protective equipment required authorized personnel only must be... clean and dry for each use, to prevent skin contact with liquid vinyl chloride. [CGFR 70-10, 35 FR 3714...

  15. Moisture-induced phase separation and recrystallization in amorphous solid dispersions.

    PubMed

    Luebbert, Christian; Sadowski, Gabriele

    2017-10-30

    Active Pharmaceutical Ingredients (APIs) are often dissolved in polymeric matrices to control the gastrointestinal dissolution and to stabilize the amorphous state of the API. During the pharmaceutical development of new formulations, stability studies via storage at certain temperature and relative humidity (RH) have to be carried out to verify the long-term thermodynamic stability of these formulations against unwanted recrystallization and moisture-induced amorphous-amorphous phase separation (MIAPS). This study focuses on predicting the MIAPS of API/polymer formulations at elevated RH. In a first step, the phase behavior of water-free formulations of ibuprofen (IBU) and felodipine (FEL) combined with the polymers poly(vinyl pyrrolidone) (PVP), poly(vinyl acetate) (PVAC) and poly (vinyl pyrrolidone-co-vinyl acetate) (PVPVA64) was determined experimentally by differential scanning calorimetry (DSC). The phase behavior of these water-free formulations was modeled using the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT). Based on this, the API solubility and MIAPS in the above-mentioned formulations at humid conditions was predicted in perfect agreement with the results of two-year lasting stability studies at 25°C/0% RH and 40°C/75% RH. MIAPS was predicted and also experimentally found for the FEL/PVP, FEL/PVPVA64 and IBU/PVP formulations, whereas MIAPS was neither predicted nor measured for the IBU/PVPVA64 system and PVAC-containing formulations. It was thus shown that the results of time-consuming long-term stability tests can be correctly predicted via thermodynamic modeling with PC-SAFT. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Cyclization Reactions through DDQ-Mediated Vinyl Oxazolidinone Oxidation

    PubMed Central

    Liu, Lei; Floreancig, Paul E.

    2009-01-01

    Vinyl oxazolidinones react with DDQ to form α,β-unsaturated acyliminium ions in a new method for forming electrophiles under oxidative conditions. Appended nucleophiles undergo 1,4-addition reactions with these intermediates to form cyclic vinyl oxazolidinones with good levels of diastereocontrol, highlighting a new approach to utilizing oxidative carbon–hydrogen bond functionalization to increase molecular complexity. PMID:19552390

  17. IRIS Toxicological Review of Vinyl Chloride (Final Report, 2000)

    EPA Science Inventory

    EPA is announcing the release of the final report, Toxicological Review of Vinyl Chloride: in support of the Integrated Risk Information System (IRIS). The updated Summary for Vinyl Chloride and accompanying Quickview have also been added to the IRIS Database.

  18. Well treating fluids and additives therefor

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

    Patel, B.

    1991-07-16

    This patent describes a solid, dry additive for reducing the water loss and improving other properties of well treating fluids in high temperature environments. It comprises a mixture of a water soluble copolymer of N-vinyl pyrrolidone and the sodium salt of 2- acrylamido-2-methylpropane sulfonic acid and an organic compound selected from the group consisting of lignites, tannins, asphaltic materials, derivatives thereof and mixtures of such compounds, the mixture of the water soluble copolymer and organic compound being prepared by mixing a water and oil emulsion containing the copolymer with the organic compound followed by removing the oil and water frommore » the resultant mixture.« less

  19. Palladium-Catalyzed Conversion of Aryl and Vinyl Triflates to Bromides and Chlorides

    PubMed Central

    Shen, Xiaoqiang; Hyde, Alan M.; Buchwald, Stephen L.

    2010-01-01

    The palladium-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl and vinyl halides can be prepared via this method in good to excellent yields. PMID:20857936

  20. Effect of pyrrolidone-pyroglutamic acid composition on blood flow in rat middle cerebral artery.

    PubMed

    Semkina, G A; Matsievskii, D D; Mirzoyan, N R

    2006-01-01

    We compared the effects of a pyrrolidone-pyroglutamic acid composition and nimodipine on blood circulation in the middle cerebral artery in rats. The composition produced a strong effect on blood supply to the brain, stimulated blood flow in the middle cerebral artery (by 60 +/- 9%) and decreased blood pressure (by 25.0 +/- 2.7%). The cerebrovascular effects of this composition differed from those of nimodipine. Nimodipine not only increased middle cerebral artery blood flow, but also decreased cerebral blood flow in the early period after treatment.

  1. Far-infrared Spectroscopic Characterization of Anti-vinyl Alcohol

    NASA Astrophysics Data System (ADS)

    Bunn, Hayley; Soliday, Rebekah M.; Sumner, Isaiah; Raston, Paul L.

    2017-09-01

    We report a detailed analysis of the high-resolution far-infrared spectrum of anti-vinyl alcohol, which has been previously identified toward Sagittarius B2(N). The ν 15 OH torsional fundamental investigated here is more than 200 cm-1 removed from the next nearest vibration, making it practically unperturbed and ideal to help refine the ground state rotational constants that were previously determined from 25 microwave lines. We assigned 1335 lines within the ν 15 fundamental centered at 261.5512 cm-1, with J and K a ranges of 1-59 and 0-16, respectively. The microwave and far-infrared line positions were fit with Watson-type A- and S-reduced Hamiltonians, with the inclusion of quartic and select sextic distortion terms. This resulted in a significant refinement of the ground state constants, in addition to the determination of the {ν }15=1 state constants for the first time. The spectroscopic parameters are in good agreement with the results from anharmonic coupled-cluster calculations, and should be useful in searches for rotationally and/or vibrationally warm anti-vinyl alcohol in interstellar molecular clouds.

  2. Sequential development of hepatocellular carcinoma and liver angiosarcoma in a vinyl chloride-exposed worker.

    PubMed

    Guido, Maria; Sarcognato, Samantha; Pelletti, Guido; Fassan, Matteo; Murer, Bruno; Snenghi, Rossella

    2016-11-01

    Strong experimental and clinical evidences have definitely linked occupational vinyl chloride exposure to development of angiosarcoma of the liver. In contrast, despite the International Agency for Research on Cancer having included vinyl chloride among the causes of hepatocellular carcinoma, the association between vinyl chloride exposure and hepatocellular carcinoma remains debated. This issue is relevant, because occupational exposure to high levels of vinyl chloride may still occur. We report a unique case of sequential occurrences of hepatocellular carcinoma and angiosarcoma of the liver, in a vinyl chloride-exposed worker without cirrhosis and any known risk factor for chronic liver disease. Both the hepatocellular carcinoma and the surrounding normal liver showed micronucleus formation, which reflects genotoxic effect of vinyl chloride. Angiosarcoma showed a KRAS G12D point mutation, which is considered to be characteristic of vinyl chloride-induced angiosarcoma. This case supports the pathogenic role of vinyl chloride in both hepatocellular carcinoma and angiosarcoma development. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Studies Update Vinyl Chloride Hazards.

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1980-01-01

    Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

  4. Angiosarcoma of the liver in Great Britain in proximity to vinyl chloride sites.

    PubMed

    Elliott, P; Kleinschmidt, I

    1997-01-01

    To study the incidence of angiosarcoma of the liver in England and Wales 1979-86 and Scotland 1975-87. To investigate whether any non-occupational neighbourhood cases occurred near a vinyl chloride site. This is a geographical study of incident cases among the general population of Great Britain. Diagnosis of angiosarcoma of the liver was based mainly on the national cancer registry, the world register of cases among vinyl chloride workers, and the register of cases (including histological review) maintained by the Health and Safety Executive. Proximity (< 10 km) of residence to a vinyl chloride site was based on postcode of address at the time of diagnosis. 55 cases were ascribed to angiosarcoma of the liver in England and Wales with a further six cases in Scotland (annual incidence in Great Britain from all sources of around 1.4 cases per 10 million population). There were two cases with documented exposure to Thorotrast, and 10 cases among vinyl chloride workers. There were no vinyl chloride sites in Scotland. Among the 25 cases in England and Wales with histological diagnosis after review by a panel of pathologists, only 15 were confirmed as angiosarcoma, and one of the two Scottish cases after histological review was also confirmed. Overall, 11 cases ascribed to angiosarcoma were resident within 10 km of a vinyl chloride site; nine were vinyl chloride workers, one further case on histological review was not considered to have been correctly diagnosed as angiosarcoma, and the remaining case, confirmed as angiosarcoma, was employed at a vinyl chloride factory during the late 1950s, although not as a vinyl chloride worker. The incidence of angiosarcoma of the liver in Great Britain remains extremely rare. The one confirmed case in a non-vinyl chloride worker within 10 km of a site must nevertheless be presumed to have been exposed to vinyl chloride in the workplace. In the period of study, there were no confirmed non-occupationally exposed cases of angiosarcoma

  5. Angiosarcoma of the liver in Great Britain in proximity to vinyl chloride sites.

    PubMed Central

    Elliott, P; Kleinschmidt, I

    1997-01-01

    OBJECTIVES: To study the incidence of angiosarcoma of the liver in England and Wales 1979-86 and Scotland 1975-87. To investigate whether any non-occupational neighbourhood cases occurred near a vinyl chloride site. METHODS: This is a geographical study of incident cases among the general population of Great Britain. Diagnosis of angiosarcoma of the liver was based mainly on the national cancer registry, the world register of cases among vinyl chloride workers, and the register of cases (including histological review) maintained by the Health and Safety Executive. Proximity (< 10 km) of residence to a vinyl chloride site was based on postcode of address at the time of diagnosis. RESULTS: 55 cases were ascribed to angiosarcoma of the liver in England and Wales with a further six cases in Scotland (annual incidence in Great Britain from all sources of around 1.4 cases per 10 million population). There were two cases with documented exposure to Thorotrast, and 10 cases among vinyl chloride workers. There were no vinyl chloride sites in Scotland. Among the 25 cases in England and Wales with histological diagnosis after review by a panel of pathologists, only 15 were confirmed as angiosarcoma, and one of the two Scottish cases after histological review was also confirmed. Overall, 11 cases ascribed to angiosarcoma were resident within 10 km of a vinyl chloride site; nine were vinyl chloride workers, one further case on histological review was not considered to have been correctly diagnosed as angiosarcoma, and the remaining case, confirmed as angiosarcoma, was employed at a vinyl chloride factory during the late 1950s, although not as a vinyl chloride worker. CONCLUSION: The incidence of angiosarcoma of the liver in Great Britain remains extremely rare. The one confirmed case in a non-vinyl chloride worker within 10 km of a site must nevertheless be presumed to have been exposed to vinyl chloride in the workplace. In the period of study, there were no confirmed non

  6. Experimental exposure of male volunteers to N-methyl-2-pyrrolidone (NMP): acute effects and pharmacokinetics of NMP in plasma and urine.

    PubMed Central

    Akesson, B; Paulsson, K

    1997-01-01

    OBJECTIVES: To study the acute effects of exposure to the increasingly used solvent, N-methyl-2-pyrrolidone (NMP) in male volunteers. Further, to determine the NMP concentration in plasma and urine during and after the exposure. METHODS: Six male volunteers were exposed for eight hours on four different days to 0, 10, 25, and 50 mg/m3 NMP. Plasma was collected and urine was sampled during and after the exposure. Changes in nasal volume were measured by acoustic rhinometry and in airway resistance by spirometry. RESULTS: The eight-hour experimental exposure to 10, 25, and 50 mg/m3 did not induce discomfort to eyes or upper airways. Acute changes in nasal volume were not found, and no changes in the spirometric data could be registered. The elimination curves suggested a non-linear pattern and at the end of exposure showed mean (range) half lifes of NMP in plasma of about 4.0 (2.9-5.8) hours and in urine 4.5 (3.5-6.6) hours. The unmetabolised NMP found in urine samples collected during exposure and at the subsequent 44 hours corresponded to about 2% of the calculated absorbed dose. At the end of the exposure there was a close correlation between exposures and the plasma concentration and urinary excretion of NMP. CONCLUSIONS: NMP was absorbed through the respiratory tract and readily eliminated from the body, mainly by biotransformation to other compounds. Exposure to 10, 25, or 50 mg/m3 NMP did not cause nose, eye, or airway irritation. Thus, NMP is a mild irritant. PMID:9166128

  7. Sol–gel auto combustion synthesis of CoFe{sub 2}O{sub 4}/1-methyl-2-pyrrolidone nanocomposite with ethylene glycol: Its magnetic characterization

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

    Topkaya, R., E-mail: rtopkaya@gyte.edu.tr; Kurtan, U.; Junejo, Y.

    2013-09-01

    Graphical abstract: - Highlights: • CoFe{sub 2}O{sub 4} was generated by sol–gel autocombustion using 1-methyl-2-pyrrolidone and ethylene glycol. • The presence of spin-disordered surface layer on magnetic core was established. • A linear dependence of the coercivity on temperature was fitted to Kneller's law. - Abstract: Magnetic nanoparticles were generated by sol–gel auto combustion synthesis of metal salts in the presence of 1-methyl-2-pyrrolidone, a functional solvent and ethylene glycol as usual solvent. The average crystallite size was obtained by using line profile fitting as 11 ± 5 nm. The saturation magnetization value decreases with usage of the ethylene glycol inmore » synthesis. The observed exchange bias effect further confirms the existence of the magnetically ordered core surrounded by spin-disordered surface layer and the ethylene glycol. Square-root temperature dependence of coercivity can be fitted to Kneller's law in the temperature range of 10–400 K. The reduced remanent magnetization values lower than the theoretical value of 0.5 for non-interacting single domain particles indicate the CoFe{sub 2}O{sub 4}-1-methyl-2-pyrrolidone nanocomposite to have uniaxial anisotropy instead of the expected cubic anisotropy according to the Stoner–Wohlfarth model.« less

  8. Environmental and Chemical Aging of Fatty-Acid-Based Vinyl Ester Composites

    DTIC Science & Technology

    2011-04-01

    Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites by Steven E. Boyd and John J. La Scala ARL-TR-5523 April...2011 Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites Steven E. Boyd and John J. La Scala Weapons and Materials...COVERED (From - To) October 2009–September 2010 4. TITLE AND SUBTITLE Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites

  9. [Effect of a drug composition containing pyroglutamic acid and pyrrolidone on the cerebral circulation].

    PubMed

    Lun'shina, E V; Gan'shina, T S; Mirzoian, R S

    2002-01-01

    A drug composition containing pyroglutamic acid and pyrrolidone produces a significant effect on the cerebral circulation in rats and cats, which is manifested by increased cerebral blood flow and by a dose-independent improvement of the microcirculation. The cerebrovascular effects were similarly pronounced in both rats and cats which indicates that the drug action is independent of the animal species. The drug combination studied did not exhibit antiserotonin activity. The data obtained show evidence of a substantial contribution of the cerebrovascular component to the neuroprotector action of the drug composition studied.

  10. Spectral Photosensitization of Optical Anisotropy in Solid Poly(Vinyl Cinnamate) Films

    NASA Astrophysics Data System (ADS)

    Kozenkov, V. M.; Spakhov, A. A.; Belyaev, V. V.; Chausov, D. N.; Chigrinov, V. G.

    2018-04-01

    The possibility and features of formation of sensitized photoinduced optical anisotropy in amorphous films of poly(vinyl cinnamate) and its derivative poly(vinyl-4-metoxicinnamate) under the action of polarized light (including light that is not absorbed by polymer macromolecules themselves) have been investigated. It is found that the effect of induced optical anisotropy is based on the transfer of electron excitation energy from donor (sensitizer) molecules to acceptor molecules and is observed in the course of phototopochemical biomolecular cyclization reaction of cinnamate fragments in polymer macromolecules. The detected photoinduced anisotropy in solid films of poly(vinyl cinnamate) and its derivative poly(vinyl-4-metoxicinnamate) ensures sensitized photo-orientation of low-molecular thermotropic liquid crystals.

  11. Vinyl chloride removal from an air stream by biotrickling filter.

    PubMed

    Faraj, S H Esmaeili; Esfahany, M Nasr; Kadivar, M; Zilouei, H

    2012-01-01

    A biofiltration process was used for degradation of vinyl chloride as a hazardous material in the air stream. Three biotrickling filters in series-parallel allowing uniform feed and moisture distribution all over the bed were used. Granular activated carbon mixed with compost was employed as carrier bed. The biological culture consisted of mixture of activated sludge from PVC wastewater treatment plant. Concurrent flow of gas and liquid was used in the bed. Results indicated that during the operation period of 110 days, the biotrickling bed was able to remove over 35% of inlet vinyl chloride. Maximum elimination capacity was calculated to be 0.56 g.m(-3).hr(-1). The amount of chlorine accumulated in the circulating liquid due to the degradation of vinyl chloride was measured to be equal to the vinyl chloride removed from the air stream.

  12. Nanocomposites prepared from acrylonitrile butadiene rubber and organically modified montmorillonite with vinyl groups

    NASA Astrophysics Data System (ADS)

    Han, Mijeong; Kim, Hoonjung; Kim, Eunkyoung

    2006-01-01

    Nanocomposites were prepared from acrylonitrile-butadiene rubber (NBR), vinyl groups containing organically modified montmorillonite and additives, such as zinc oxide, stearic acid, and sulfur. The organically modified montmorillonites used in these nanocomposites were prepared by ion exchange reactions of N,N'-dimethylalkyl-(p-vinylbenzyl)-ammonium chlorides (DAVBAs, alkyl = octyl, dodecyl, and octadecyl) with sodium montmorillonite (Na+-MMT). NBR nanocomposites were obtained by controlling both the mixing and vulcanization conditions, by using a Brabender mixer and hot-press process. X-ray diffraction (XRD) analysis shows that, depending on the amount of montmorillonite that is added, both exfoliated and intercalated nanocomposite structures are formed. The NBR/DAVBA-MMT nanocomposites exhibit much higher mechanical properties (e.g., tensile strength, Young's modulus, 300% modulus, and hardness) as well as gas barrier properties as compared to NBR Na+-MMT or NBR composites generated from modified montmorillonites without vinyl groups. Consistent with the results of XRD, transmission electron microscopy (TEM) reveals that the intercalation and exfoliation structures of the nanocomposites coexist and that the DAVBA-MMT layers are well dispersed in NBR.

  13. Laser Spectroscopy of Vinyl Alcohol Embedded in Helium Droplets

    NASA Astrophysics Data System (ADS)

    Bunn, Hayley; Raston, Paul; Douberly, Gary E.

    2017-06-01

    Vinyl alcohol has two rotameric forms, known as syn- and anti-vinyl alcohol, where syn is the most stable. While both have been investigated by microwave and far-infrared spectroscopy, only the syn rotamer has been investigated by mid-infrared spectroscopy. This is due to the low anti rotamer population (15%) at room temperature, in addition to the closeness in proximity of the mid-infrared bands between the rotamers; this results in overlapping bands that are dominated by syn-vinyl alcohol absorptions. In this investigation we increase the anti-vinyl alcohol population to 40% by using a high temperature "pyrolysis" source, and eliminate the spectral overlap by recording the spectra at low temperature in helium nanodroplets. We observe a number of bands of both rotamers in the OH, CH, and CO stretching regions that display rotational substructure. A highlight of this work is the observation of a Fermi dyad in the OH stretching region of anti-vinyl alcohol. Anharmonic frequency calculations suggest that this is due to a near degeneracy of the OH stretching state (νb{1}) with a triple combination involving νb{7}, νb{8}, and νb{9}. M. Rodler, J. Mol. Spec. 114, 23 (1985);S. Saito, Chem. Phys. Lett. 42, 3 (1976) H. Bunn, R. Hudson, A. S. Gentleman, and P. L. Raston, ACS Earth Space Chem. DOI: 10.1021/acsearthspacechem.6b00008 (2017) D-L Joo, A. J. Merer, D. J. Clouthier, J. Mol. Spec. 197, 68 (1999)

  14. Experimental investigations on potassium permanganate doped polyvinyl alcohol - polyvinyl pyrrolidone blend

    NASA Astrophysics Data System (ADS)

    Veena, G.; Lobo, Blaise

    2018-04-01

    Potassium permanganate (KMnO4) doped polyvinyl alcohol (PVA) - polyvinyl pyrrolidone (PVP) blend films were prepared by solution casting technique, in the doping range varying from 0.01 wt % up to 4.70 wt %. The microstructural changes caused by doping, and the modified properties of these films were studied using Atomic Force Microscope (AFM) and temperature dependent direct current (DC) electrical measurements. Temperature variation of electrical resistivity was found to obey Arrhenius relation, from which activation energy was determined. The study was supported by AFM scans, which showed an increase in surface roughness and the presence of spike-like structures, due to interaction of dopant with the polymeric blend. Differential Scanning Calorimetry (DSC) scans revealed two stages of degradation in KMnO4 doped PVA - PVP blend films.

  15. Influence of humidity on the phase behavior of API/polymer formulations.

    PubMed

    Prudic, Anke; Ji, Yuanhui; Luebbert, Christian; Sadowski, Gabriele

    2015-08-01

    Amorphous formulations of APIs in polymers tend to absorb water from the atmosphere. This absorption of water can induce API recrystallization, leading to reduced long-term stability during storage. In this work, the phase behavior of different formulations was investigated as a function of relative humidity. Indomethacin and naproxen were chosen as model APIs and poly(vinyl pyrrolidone) (PVP) and poly(vinyl pyrrolidone-co-vinyl acetate) (PVPVA64) as excipients. The formulations were prepared by spray drying. The water sorption in pure polymers and in formulations was measured at 25°C and at different values of relative humidity (RH=25%, 50% and 75%). Most water was absorbed in PVP-containing systems, and water sorption was decreasing with increasing API content. These trends could also be predicted in good agreement with the experimental data using the thermodynamic model PC-SAFT. Furthermore, the effect of absorbed water on API solubility in the polymer and on the glass-transition temperature of the formulations was predicted with PC-SAFT and the Gordon-Taylor equation, respectively. The absorbed water was found to significantly decrease the API solubility in the polymer as well as the glass-transition temperature of the formulation. Based on a quantitative modeling of the API/polymer phase diagrams as a function of relative humidity, appropriate API/polymer compositions can now be selected to ensure long-term stable amorphous formulations at given storage conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. 40 CFR 721.5960 - N,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt (generic name). 721.5960 Section 721.5960...,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt... methyl sulfate double salt (PMN P-84-913) is subject to reporting under this section for the significant...

  17. 40 CFR 721.5960 - N,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt (generic name). 721.5960 Section 721.5960...,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt... methyl sulfate double salt (PMN P-84-913) is subject to reporting under this section for the significant...

  18. 40 CFR 721.5960 - N,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt (generic name). 721.5960 Section 721.5960...,N′-Bis(2-(2-(3-alkyl)thia- zoline) vinyl)-1,4-pheny-lene-dia-mine methyl sulfate double salt... methyl sulfate double salt (PMN P-84-913) is subject to reporting under this section for the significant...

  19. Novel targeted approaches to treating biliary tract cancer: the dual epidermal growth factor receptor and ErbB-2 tyrosine kinase inhibitor NVP-AEE788 is more efficient than the epidermal growth factor receptor inhibitors gefitinib and erlotinib.

    PubMed

    Wiedmann, Marcus; Feisthammel, Jürgen; Blüthner, Thilo; Tannapfel, Andrea; Kamenz, Thomas; Kluge, Annett; Mössner, Joachim; Caca, Karel

    2006-08-01

    Aberrant activation of the epidermal growth factor receptor is frequently observed in neoplasia, notably in tumors of epithelial origin. Attempts to treat such tumors with epidermal growth factor receptor antagonists resulted in remarkable success in recent studies. Little is known, however, about the efficacy of this therapy in biliary tract cancer. Protein expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 was assessed in seven human biliary tract cancer cell lines by immunoblotting. In addition, histological sections from 19 patients with extrahepatic cholangiocarcinoma were analyzed for epidermal growth factor receptor, ErbB-2 and vascular endothelial growth factor receptor-2 expression by immunohistochemistry. Moreover, we sequenced the cDNA products representing the entire epidermal growth factor receptor coding region of the seven cell lines, and searched for genomic epidermal growth factor receptor amplifications and polysomy by fluorescence in-situ hybridization. Cell growth inhibition by gefitinib erlotinib and NVP-AEE788 was studied in vitro by automated cell counting. In addition, the anti-tumoral effect of erlotinib and NVP-AEE788 was studied in a chimeric mouse model. The anti-tumoral drug mechanism in this model was assessed by MIB-1 antibody staining, terminal deoxynucleotidyl transfer-mediated dUTP nick end-labelling assay, von Willebrand factor staining, and immunoblotting for p-p42/44 (p-Erk1/2, p-MAPK) and p-AKT. Immunoblotting revealed expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 in all biliary tract cancer cell lines. EGFR was detectable in six of 19 (32%) extrahepatic human cholangiocarcinoma tissue samples, ErbB-2 in 16 of 19 (84%), and vascular endothelial growth factor receptor-2 in nine of 19 (47%). Neither epidermal growth factor receptor mutations nor amplifications or polysomy were found in the seven biliary tract cancer

  20. Synthesis of nucleosides and oligonucleotides containing adducts of acrolein and vinyl chloride.

    PubMed

    Nechev, L V; Harris, C M; Harris, T M

    2000-05-01

    Vinyl chloride and acrolein are important industrial chemicals. Both form DNA adducts, vinyl chloride after enzymatic oxidation to chlorooxirane and acrolein by direct reaction. Reaction at the N(2) position of guanine is a major pathway. The resulting 2-oxoethyl and 3-oxopropyl adducts cyclize spontaneously to hydroxyethano and hydroxypropano derivatives, respectively. The two cyclic adducts have been detected in DNA exposed to these mutagens. A new method has been developed for the synthesis of deoxyguanosine adducts of chlorooxirane and acrolein, as well as oligonucleotides containing these adducts. Reaction of O(6)-[(trimethylsilyl)ethyl]-2-fluoro-2'-deoxyinosine with the appropriate aminodiol followed by oxidative cleavage of the diol with NaIO(4) gave the adducts in excellent yields. Reaction of oligonucleotides containing the halonucleoside with the aminodiols followed by NaIO(4) efficiently created the nucleosides in the oligonucleotides. Deoxyadenosine adducts were created similarly using 6-chloropurine 9-(2'-deoxyriboside).

  1. Physical-chemical properties and the reactivity of pyridoxine and pyrrolidone carboxylate and their protolytic forms.

    PubMed

    Golovenko, N Ya; Larionov, V B; Karpova, O V

    2016-01-01

    Preparation Methadoxine is equimolar salt, which cationic component (pyridoxine) is 3-oxypyridine derivative, possessing B6-vitamine like activity, while anionic component is the cyclic lactame of glutamic acid. Since biopharmaceutical and pharmacological properties of this drug depend on biochemical transformation its components, of the aim of this work was to determine the structure of possible ionized pyridoxine and pyrrolidone carboxylate forms and their reaction ability in biochemical processes. Physical-chemical properties of compounds (pKa, logP, logD, proton donor/acceptor quantity, solubility (g/l)) were calculated with ACD/pKaDB program or obtained from Pub-Med physical/chemical properties database. UV spectra of compounds were obtained after dissolution in different pH solutions (1.0, 4.5 and 6.8). It was found that at different pH values one can observe changes of the absorption spectra due to the presence of prevailing amount of the protonated form. An analysis of both pKa, logP and logD indicators and reactive functional groups of Methadoxine components has revealed that they can be protonated in different regions of gastro-intestinal tract, that influences their solubility in hydrophilic and lypophilic media. Pharmacological properties of pyridoxine and pyrrolidone carboxylate themselves are performed after their preliminary biotransformation to active metabolites. Only ionic interaction between Methadoxine components in the substance composition can appear, that provides its pharmaceutical stability and ensures its activity only in the organism conditions.

  2. Determination of Vinyl Chloride at ug/l. Level in Water by Gas Chromatography

    ERIC Educational Resources Information Center

    Bellar, Thomas A.; And Others

    1976-01-01

    A quantitative method for the determination of vinyl chloride in water is presented. Vinyl chloride is transfered to the gas phase by bubbling inert gas through the water. After concentration on silica gel or Carbosieve-B, determination is by gas chromatography. Confirmation of vinyl chloride is by gas chromatography-mass spectrometry. (Author/BT)

  3. Method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, Jr., Earle D.

    1995-01-01

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  4. Method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, E.D. Jr.

    1995-07-11

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  5. Hydrogen-Mediated Electron Doping of Gold Clusters As Revealed by In Situ X-ray and UV-vis Absorption Spectroscopy.

    PubMed

    Ishida, Ryo; Hayashi, Shun; Yamazoe, Seiji; Kato, Kazuo; Tsukuda, Tatsuya

    2017-06-01

    We previously reported that small (∼1.2 nm) gold clusters stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP) exhibited a localized surface plasmon resonance (LSPR) band at ∼520 nm in the presence of NaBH 4 . To reveal the mechanism of this phenomenon, the electronic structure of Au:PVP during the reaction with NaBH 4 in air was examined by means of in situ X-ray absorption spectroscopy at Au L 3 -edge and UV-vis spectroscopy. These measurements indicated that the appearance of the LSPR band is not associated with the growth in size but is ascribed to electron doping to the Au sp band by the adsorbed H atoms.

  6. Vintage Vinyl Record Design

    ERIC Educational Resources Information Center

    Sacco, Michael

    2008-01-01

    In this article, the author describes a project in which his ninth-grade art students utilized a vinyl record as an unusual medium to create a work that exhibited solid design, great creativity, and strong craftsmanship. Students presented their pieces to the class for critique, explained the process, the media, and their feelings about their…

  7. Formation of vinyl halides via a ruthenium-catalyzed three-component coupling.

    PubMed

    Trost, Barry M; Pinkerton, Anthony B

    2002-06-26

    The ruthenium-catalyzed three-component coupling of an alkyne, an enone, and halide ion to form E- or Z-vinyl halides has been investigated. Through systematic optimization experiments, the conditions effecting the olefin selectivity were examined. In general, more polar solvents such as DMF favored the formation of the E-isomer, and less polar solvents such as acetone favored formation of the Z-isomer. The optimized conditions for the formation of E-vinyl chlorides were found to be the use of cyclopentadienyl ruthenium (II) cyclooctadiene chloride, stannic chloride pentahydrate as a cocatalyst, and for a chloride source, either ammonium chloride in DMF/water mixtures or tetramethylammonium chloride in DMF. A range of several other ruthenium (II) catalysts was also shown to be effective. A wide variety of vinyl chlorides could be formed under these conditions. Substrates with tethered alcohols or ketones either five or six carbons from the alkyne portion gave instead diketone or cyclohexenone products. For formation of vinyl bromides, a catalyst system involving the use of cyclopentadienylruthenium (II) tris(acetonitrile) hexafluorophosphate with stannic bromide as a cocatalyst was found to be most effective. The use of ammonium bromide in DMF/acetone mixtures was optimal for the synthesis of E-vinyl bromides, and the use of lithium bromide in acetone was optimal for formation of the corresponding Z-isomer. Under either set of conditions, a wide range of vinyl bromides could be formed. When alkynes with propargylic substituents are used, enhanced selectivity for formation of the Z-isomer is observed. When aryl acetylenes are used as the coupling partners, complete selectivity for the Z-isomer is obtained. A mechanism involving a cis or trans halometalation is invoked to explain formation of the observed products. The vinyl halides have been shown to be precursors to alpha-hydroxy ketones and cyclopentenones, and as coupling partners in Suzuki-type reactions.

  8. 77 FR 12328 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Vinyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... for OMB Review; Comment Request; Vinyl Chloride Standard ACTION: Notice. SUMMARY: The Department of... collection request (ICR) titled, ``Vinyl Chloride Standard,'' to the Office of Management and Budget (OMB... email at [email protected] . SUPPLEMENTARY INFORMATION: The purpose of the Vinyl Chloride Standard...

  9. Visible-light sensitization of vinyl azides by transition-metal photocatalysis.

    PubMed

    Farney, Elliot P; Yoon, Tehshik P

    2014-01-13

    Irradiation of vinyl and aryl azides with visible light in the presence of Ru photocatalysts results in the formation of reactive nitrenes, which can undergo a variety of C-N bond-forming reactions. The ability to use low-energy visible light instead of UV in the photochemical activation of azides avoids competitive photodecomposition processes that have long been a significant limitation on the synthetic use of these reactions. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. 40 CFR 721.10484 - Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Siloxanes and Silicones, Me vinyl... Substances § 721.10484 Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with...) The chemical substance identified as Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction...

  11. 40 CFR 721.10484 - Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Siloxanes and Silicones, Me vinyl... Substances § 721.10484 Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with...) The chemical substance identified as Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction...

  12. Radicals derived from acetaldehyde and vinyl alcohol.

    PubMed

    Estep, Marissa L; Morgan, W James; Winkles, Alexander T; Abbott, Adam S; Villegas-Escobar, Nery; Mullinax, J Wayne; Turner, Walter E; Wang, Xiao; Turney, Justin M; Schaefer, Henry F

    2017-10-18

    Vinyl alcohol and acetaldehyde are isoelectronic products of incomplete butanol combustion. Along with the radicals resulting from the removal of atomic hydrogen or the hydroxyl radical, these species are studied here using ab initio methods as complete as coupled cluster theory with single, double, triple, and perturbative quadruple excitations [CCSDT(Q)], with basis sets as large as cc-pV5Z. The relative energies provided herein are further refined by including corrections for relativistic effects, the frozen core approximation, and the Born-Oppenheimer approximation. The effects of anharmonic zero-point vibrational energies are also treated. The syn conformer of vinyl alcohol is predicted to be lower in energy than the anti conformer by 1.1 kcal mol -1 . The alcoholic hydrogen of syn-vinyl alcohol is found to be the easiest to remove, requiring 84.4 kcal mol -1 . Five other radicals are also carefully considered, with four conformers investigated for the 1-hydroxyvinyl radical. Beyond energetics, we have conducted an overhaul of the spectroscopic literature for these species. Our results also provide predictions for fundamental modes yet to be reported experimentally. To our knowledge, the ν 3 (3076 cm -1 ) and ν 4 (2999 cm -1 ) C-H stretches for syn-vinyl alcohol and all but one of the vibrational modes for anti-vinyl alcohol (ν 1 -ν 14 ) are yet to be observed experimentally. For the acetyl radical, ν 6 (1035 cm -1 ), ν 11 (944 cm -1 ), ν 12 (97 cm -1 ), and accounting for our changes to the assignment of the 1419.9 cm -1 experimental mode, ν 10 (1441 cm -1 ), are yet to be observed. We have predicted these unobserved fundamentals and reassigned the experimental 1419.9 cm -1 frequency in the acetyl radical to ν 4 rather than to ν 10 . Our work also strongly supports reassignment of the ν 10 and ν 11 fundamentals of the vinoxy radical. We suggest that the bands assigned to the overtones of these fundamentals were in fact combination bands. Our

  13. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and quaternary...

  14. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and quaternary...

  15. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and quaternary...

  16. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and quaternary...

  17. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and quaternary...

  18. N-vinylpyrrolidone modified glass-ionomer resins for improved dental restoratives

    NASA Astrophysics Data System (ADS)

    Xie, Dong

    The studies described in this dissertation focus on improvement of mechanical properties of current glass-ionomer cements. Thermal properties and microstructures of the cements were correlated with their mechanical strengths. The first study evaluated mechanical properties of selected commercial glass-ionomer cements and examined their microstructures. The results showed that resin-modified glass-ionomer cements (RM GICs) exhibited much higher flexural (FS) and diametral tensile strengths (DTS), compared to conventional GICs (C GICs). In addition, they exhibited comparable compressive strength (CS), relatively low microhardness and less wear resistance than C GICs. The C GICs exhibited brittle behavior, whereas the RM GICs underwent substantial plastic deformation in compression. The mechanical properties of the GICs were closely related to their microstructures. Factors such as the density of the microstructure, the integrity of the interface between the glass particles and polymer matrix, particle size and the number and size of voids have important roles in determining the mechanical properties. The second study evaluated thermal properties of these GICs. The results showed that the RM GICs exhibited higher thermal transition temperatures than those of the C GICs, thermal expansion coefficients of these cements were close to those of human teeth, and the indentation creep of the RM GICs were higher than the C GICs. The third study explored and evaluated the effect of a water-soluble monomer, N-vinylpyrrolidone (NVP), on the performance of current C GICs, indicating a significant improvement in both mechanical and working properties. The fourth study demonstrated the process of determining the optimal molar ratio of the NVP-containing copolymers, using design of experiment. The results showed that the optimal molar ratio for these copolymers was 7:1:3 for poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone), based on the FS test. The molar ratio of 8:2:1 (AA:IA:NVP

  19. Modification of conventional glass-ionomer cements with N-vinylpyrrolidone containing polyacids, nano-hydroxy and fluoroapatite to improve mechanical properties.

    PubMed

    Moshaverinia, Alireza; Ansari, Sahar; Movasaghi, Zanyar; Billington, Richard W; Darr, Jawwad A; Rehman, Ihtesham U

    2008-10-01

    The objective of this study was to enhance the mechanical strength of glass-ionomer cements, while preserving their unique clinical properties. Copolymers incorporating several different segments including N-vinylpyrrolidone (NVP) in different molar ratios were synthesized. The synthesized polymers were copolymers of acrylic acid and NVP with side chains containing itaconic acid. In addition, nano-hydroxyapatite and fluoroapatite were synthesized using an ethanol-based sol-gel technique. The synthesized polymers were used in glass-ionomer cement formulations (Fuji II commercial GIC) and the synthesized nanoceramic particles (nano-hydroxy or fluoroapatite) were also incorporated into commercial glass-ionomer powder, respectively. The synthesized materials were characterized using FTIR and Raman spectroscopy and scanning electron microscopy. Compressive, diametral tensile and biaxial flexural strengths of the modified glass-ionomer cements were evaluated. After 24h setting, the NVP modified glass-ionomer cements exhibited higher compressive strength (163-167 MPa), higher diametral tensile strength (DTS) (13-17 MPa) and much higher biaxial flexural strength (23-26 MPa) in comparison to Fuji II GIC (160 MPa in CS, 12MPa in DTS and 15 MPa in biaxial flexural strength). The nano-hydroxyapatite/fluoroapatite added cements also exhibited higher CS (177-179 MPa), higher DTS (19-20 MPa) and much higher biaxial flexural strength (28-30 MPa) as compared to the control group. The highest values for CS, DTS and BFS were found for NVP-nanoceramic powder modified cements (184 MPa for CS, 22 MPa for DTS and 33 MPa for BFS) which were statistically higher than control group. It was concluded that, both NVP modified and nano-HA/FA added glass-ionomer cements are promising restorative dental materials with improved mechanical properties.

  20. RAFT Aqueous Dispersion Polymerization of N-(2-(Methacryloyloxy)ethyl)pyrrolidone: A Convenient Low Viscosity Route to High Molecular Weight Water-Soluble Copolymers.

    PubMed

    Cunningham, Victoria J; Derry, Matthew J; Fielding, Lee A; Musa, Osama M; Armes, Steven P

    2016-06-28

    RAFT solution polymerization of N -(2-(methacryoyloxy)ethyl)pyrrolidone (NMEP) in ethanol at 70 °C was conducted to produce a series of PNMEP homopolymers with mean degrees of polymerization (DP) varying from 31 to 467. Turbidimetry was used to assess their inverse temperature solubility behavior in dilute aqueous solution, with an LCST of approximately 55 °C being observed in the high molecular weight limit. Then a poly(glycerol monomethacylate) (PGMA) macro-CTA with a mean DP of 63 was chain-extended with NMEP using a RAFT aqueous dispersion polymerization formulation at 70 °C. The target PNMEP DP was systematically varied from 100 up to 6000 to generate a series of PGMA 63 -PNMEP x diblock copolymers. High conversions (≥92%) could be achieved when targeting up to x = 5000. GPC analysis confirmed high blocking efficiencies and a linear evolution in M n with increasing PNMEP DP. A gradual increase in M w / M n was also observed when targeting higher DPs. However, this problem could be minimized ( M w / M n < 1.50) by utilizing a higher purity grade of NMEP (98% vs 96%). This suggests that the broader molecular weight distributions observed at higher DPs are simply the result of a dimethacrylate impurity causing light branching, rather than an intrinsic side reaction such as chain transfer to polymer. Kinetic studies confirmed that the RAFT aqueous dispersion polymerization of NMEP was approximately four times faster than the RAFT solution polymerization of NMEP in ethanol when targeting the same DP in each case. This is perhaps surprising because both 1 H NMR and SAXS studies indicate that the core-forming PNMEP chains remain relatively solvated at 70 °C in the latter formulation. Moreover, dissolution of the initial PGMA 63 -PNMEP x particles occurs on cooling from 70 to 20 °C as the PNMEP block passes through its LCST. Hence this RAFT aqueous dispersion polymerization formulation offers an efficient route to a high molecular weight water-soluble polymer

  1. Biomedical applications of stereoregular poly(vinyl alcohol) micro- and nanoparticles

    NASA Astrophysics Data System (ADS)

    Lyoo, Won Seok; Kim, Joon Ho; Kim, Sam Soo; Ghim, Han Do

    2002-11-01

    Syndiotactic poly(vinyl alcohol) (PVA)/poly(vinyl pivalate/vinyl acetate) (P(VPi/VAc)) and atactic PVA/PVAc micro- and nanoparticles with skin/core structure have been prepared by heterogeneous saponification of P(VPi/VAc) and PVAc micro- and nanoparticles. Especially, to prepare P(VPi/VAc) and PVAc microparticles having various particle sizes and uniform particle size distribution, vinyl pivalate (VPi)/vinyl acetate (VAc) and VAc were suspension-polymerized using a low-temperature initiator, 2,2"-azobis(2,4-dimethylvaleronitrile). P(VPi/VAc) particles are promising precursor of stereoregular PVA embolic materials which can be introduced through catheters in the management of gastrointestinal bleeders, arteriovenous malformations, hemangiomas, and traumatic rupture of blood vessels. Monodisperse and/or nearly monodisperse P(VPi/VAc) and PVAc microparticles with various particle diameters were obtained by controlling suspension polymerization conditions. Monodisperse P(VPi/VAc) and PVAc microparticles having various particle sizes were partially saponified in the heterogeneous system. PVA/P(VPi/VAc) and PVA/PVAc microparticles having various tacticity and degree of saponification were produced by controlling various polymerization and saponification conditions. The coating of stereoregular PVA micro- and nanoparticles for drug release experiments was conducted with the strepo-avidin-alkaline phosphatase conjugate in variable conditions of pH value, coating buffer, and reaction temperature. Protein-coated syndiotactic PVA micro- and nanoparticles, which does not crosslinking, were more superior to controllability of drug release, durability, and dimensional stability to water and blood than atactic one.

  2. Effects of N-methyl pyrrolidone on the uptake of hypericin in human bladder carcinoma and co-staining with DAPI investigated by confocal microscopy.

    PubMed

    Saw, Constance Lay Lay; Olivo, Malini; Wohland, Thorsten; Fu, Chit Yaw; Kho, Kiang Wei; Soo, Khee Chee; Sia Heng, Paul Wan

    2007-10-01

    Photodynamic diagnosis (PDD) using hypericin (HY), a natural photosensitizer, detects bladder cancer significantly better than white light endoscopy. However, the lipophilicity of HY complicates its administration for clinical applications. Currently, pharmaceutical preparations for HY without plasma protein are being developed. Formulations containing a biocompatible solvent, N-methyl pyrrolidone (NMP) have been shown to enhance the photodynamic therapeutic effects of HY. It was recently reported that, NMP formulations of HY were able to produce significantly higher contrast for fluorescence detection of tumors than albumin-containing HY formulations. This present work hypothesizes that NMP acts both as a solvent and penetration enhancer to improve the delivery of HY into cells by increasing the permeability of cell membranes. This paper reports the use of 3-D confocal microscopy to monitor real-time uptake of HY in human carcinoma. 3-D confocal microscopy was used to investigate the possibility of nuclear localization of HY in MGH cells. The fluorescence of HY was confirmed to be emitted from HY containing cells using spectrometry. The localization of a DNA fluorescent probe 4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) was used to confirm the possibility of colocalization of DAPI and HY. The colocalization analysis in the present study suggests that it was very unlikely that HY colocalized in the nucleus that was stained by DAPI. Fluorescein leakage tests showed that 1% NMP changes the permeability of cell membranes, and enhanced the delivery of HY into cells resulting in lower cell survival ratios. Thus, NMP was able to enhance the photodynamic therapeutic effects of HY on cancer cells.

  3. Poly(1-Vinyl-1,2,4-triazolium) Poly(Ionic Liquid)s: Synthesis and the Unique Behavior in Loading Metal Ions.

    PubMed

    Zhang, Weiyi; Yuan, Jiayin

    2016-07-01

    Herein, the synthesis of a series of poly(4-alkyl-1-vinyl-1,2,4-triazolium) poly(ionic liquid)s is reported either via straightforward free radical polymerization of their corresponding ionic liquid monomers or via anion metathesis of the polymer precursors bearing halide as counter anion. The ionic liquid monomers are first prepared via N-alkylation reaction of commercially available 1-vinyl-1,2,4-triazole with alkyl iodides, followed by anion metathesis with targeted fluorinated anions. The thermal properties and solubilities of these poly(ionic liquid)s have been systematically investigated. Interestingly, it is found that the poly(4-ethyl-1-vinyl-1,2,4-triazolium) poly(ionic liquid) exhibited an improved loading capacity of transition metal ions in comparison with its imidazolium counterpart. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Plug Repairs of Marine Glass Fiber / Vinyl Ester Laminates Subjected to Uniaxial Tension

    DTIC Science & Technology

    2009-06-01

    Material characteristics of glass fiber / vinyl ester composites used in naval surface ships 1.1.1.2 Construction of surface ship hulls with FRP...Piping - Ventilation ducts - Deck gratings 1.1.1.1 Material characteristics of glass fiber / vinyl ester composites used in naval surface ships The...that polysester-based composites do [15, 24]. Typical processing methods for vinyl ester composites are hand lay-up, Resin Transfer Molding (RTM

  5. Specific adhesion model for bonding hot-melt polyamides to vinyl

    Treesearch

    Charles R. Frihart

    2004-01-01

    Hot-melt polyamides are an important market for the dimer acid made from the tall oil fatty acids liberated during the Kraft pulping process. These polyamides bond well to many substrates, but not to polyvinyl chloride (PVC), commonly called vinyl. Dimer-based polyamides made from secondary amines such as piperazine bond well to vinyl. No model for this unique adhesion...

  6. The Vinyl Acetate Content of Packaging Film: A Quantitative Infrared Experiment.

    ERIC Educational Resources Information Center

    Allpress, K. N.; And Others

    1981-01-01

    Presents an experiment used in laboratory technician training courses to illustrate the quantitative use of infrared spectroscopy which is based on industrial and laboratory procedures for the determination of vinyl acetate levels in ethylene vinyl acetate packaging films. Includes three approaches to allow for varying path lengths (film…

  7. Do occupational exposures to vinyl chloride cause hepatocellular carcinoma and cirrhosis?

    PubMed

    Lotti, Marcello

    2017-05-01

    Controversy exists about the association between occupational exposures to vinyl chloride and hepatocellular carcinoma and cirrhosis. Two large multicentre mortality cohort studies, one American and another European, reported higher mortality for primary cancer of liver and biliary tract. However, the American study was not able to rule out misclassification, because based on death certificates and under the heading primary liver cancers, some angiosarcomas, the typical neoplasia associated with vinyl chloride, may have been included. The American study does not report on cirrhosis mortality. The European study also reports higher mortality of primary liver cancer, but contrary to the American study in a further analysis based on 10 verified cases of hepatocellular carcinoma, an exposure-response trend with duration of employment and with cumulative exposure to vinyl chloride was detected. A smaller cohort belonging to this multicentre cohort confirmed these results. Meta-analyses based on the two large cohorts concluded for a small excess of primary liver cancer, although misclassification could not be ruled out. Excess risk of cirrhosis was reported in the European cohort, in a subcohort and in a cross-sectional study. However, a meta-analysis did not confirm this excess. Several critical appraisals of the literature reached antithetical conclusions about hepatocellular carcinoma, cirrhosis and occupational exposures to vinyl chloride. For both hepatocellular carcinoma and cirrhosis, a study suggests an additive and multiplicative effect of vinyl chloride exposure with viral hepatitis and alcohol consumption respectively. Pathology reports seem to indicate a possible development of hepatocellular carcinoma but not of cirrhosis after high exposures to vinyl chloride. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. 75 FR 42311 - Third Party Testing for Certain Children's Products; Vinyl Plastic Film: Requirements for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Testing for Certain Children's Products; Vinyl Plastic Film: Requirements for Accreditation of Third Party... relating to vinyl plastic film. The Commission is issuing this notice of requirements pursuant to the.... Comments should be captioned ``Third Party Testing for Certain Children's Products; Vinyl Plastic Film...

  9. Influence of chain microstructure on thermodegradative behavior of furfuryl methacrylate-N-vinylpyrrolidone random copolymers by thermogravimetry

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

    Peniche, C.; Zaldivar, D.; Bulay, A.

    1993-12-20

    The thermal behavior of random copolymers of furfuryl methacrylate (F) and N-vinyl-pyrrolidone (P) was studied by means of dynamic thermogravimetric analysis (TGA) in the range 100--600 C. The dynamic experiments show that these copolymers exhibit two degradation steps in the intervals 260--320 C and 350--520 C, respectively. The normalized weight loss in the low temperature interval increases as the mole fraction of F in the copolymer m[sub F] increases, whereas an inverted trend in the high temperature interval is observed. The apparent activation energy E[sub a] of the first degradation step for copolymers prepared with different composition, was obtained accordingmore » to the treatment suggested by Broido. A plot of the values of E[sub a] versus the F dead molar fraction in the copolymer chains m[sub FF] gave a straight line that indicates that there is a direct relationship between the thermogravimetric behavior of these systems and their corresponding microstructure, that is, the distribution of comonomeric units along the copolymers chains. The first decomposition step was also studied by isothermal TGA and a good linearity for the variation of the weight loss percentage [Delta]W versus m[sub F] at least during the first 30 min of treatment was obtained.« less

  10. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by... methacrylate-dye reaction product listed under this section into commerce shall submit to the Food and Drug...

  11. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by... methacrylate-dye reaction product listed under this section into commerce shall submit to the Food and Drug...

  12. Effect of gamma ray on poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends as biodegradable food packaging films

    NASA Astrophysics Data System (ADS)

    Razavi, Seyed Mohammad; Dadbin, Susan; Frounchi, Masoud

    2014-03-01

    Poly(lactic acid) (PLA)/poly(vinyl acetate-co-vinyl alcohol) [P(VAc-co-VA)] blends as new transparent film packaging materials were prepared at various blend compositions and different vinyl alcohol contents. The blends and pure PLA were irradiated by gamma rays to investigate the extent of changes in the packaging material during gamma ray sterilization process. The miscibility of the blends was dependent on the blend composition and vinyl alcohol content; gamma irradiation had little effect on the extent of miscibility. The glass transition temperature of pure PLA and PLA/P(VAc-co-VA) miscible blends reduced after irradiation. On the other hand in PLA/P(VAc-co-VA) immiscible blends, while the glass transition temperature of the PLA phase decreased; that of the copolymer phase slightly increased. The reduction in the glass transition was about 10 percent for samples irradiated with 50 kGy indicating dominance of chain scission of PLA molecules at high irradiation dose. The latter was verified by drop in mechanical properties of pure PLA after exposing to gamma irradiation at 50 kGy. Blending of PLA with the copolymer P(VAc-co-VA) compensated greatly the adverse effects of irradiation on PLA. The oxygen-barrier property of the blend was superior to the neat PLA and remained almost intact with irradiation. The un-irradiated and irradiated blends had excellent transparency. Gamma ray doses used for sterilization purposes are usually less than 20 kGy. It was shown that gamma irradiation at 20 kGy had no or little adverse effects on PLA/P(VAc-co-VA) blends mechanical and gas barrier properties.

  13. Kinetic and theoretical studies of novel biodegradable thermo-sensitive xerogels based on PEG/PVP/silica for sustained release of enrofloxacin

    NASA Astrophysics Data System (ADS)

    Ebadi, Azra; Rafati, Amir Abbas; Bavafa, Sadeghali; Mohammadi, Masoumah

    2017-12-01

    This study involves the synthesis of a new silica-based colloidal hybrid system. In this new hybrid system, poly (ethylene glycol) (PEG) and thermo-sensitive amphiphilic biocompatible poly (vinyl pyrrolidone) (PVP) were used to create suitable storage for hydrophobic drugs. The possibility of using variable PVP/PEG molar ratios to modulate drug release rate from silica nanoparticles was a primary goal of the current research. In addition, an investigation of the drug release kinetic was conducted. To achieve this, silica nanoparticles were synthesized in poly (ethylene glycol) (PEG) and poly (vinyl pyrrolidone) (PVP) solution incorporated with enrofloxacin (EFX) (as a model hydrophobic drug), using a simple synthetic strategy of hybrid materials which avoided waste and multi-step processes. The impacts of PVP/PEG molar ratios, temperature, and pH of the release medium on release kinetic were investigated. The physicochemical properties of the drug-loaded composites were studied by Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). In vitro drug release studies demonstrated that the drug release rate, which was evaluated by analyzing the experimental data with seven kinetic models in a primarily non-Fickian diffusion-controlled process, aligned well with both Ritger-Peppas and Sahlin-Peppas equations.

  14. Magnetically recoverable magnetite/gold catalyst stabilized by poly(N-vinyl-2-pyrrolidone) for aerobic oxidation of alcohols.

    PubMed

    Chen, Hsiao Wei; Murugadoss, Arumugam; Hor, T S Andy; Sakurai, Hidehiro

    2010-12-29

    Fe(3)O(4):PVP/Au nanocomposite synthesized via a two-step procedure was tested as a quasi-homogenous alcohol oxidation catalyst. It was found that the nanocomposite was able to carry out aerobic oxidation of alcohols in water at room temperature. Studies show rapid magnetic recoverability and reusability characteristics.

  15. Merging photoredox and nickel catalysis: decarboxylative cross-coupling of carboxylic acids with vinyl halides.

    PubMed

    Noble, Adam; McCarver, Stefan J; MacMillan, David W C

    2015-01-21

    Decarboxylative cross-coupling of alkyl carboxylic acids with vinyl halides has been accomplished through the synergistic merger of photoredox and nickel catalysis. This new methodology has been successfully applied to a variety of α-oxy and α-amino acids, as well as simple hydrocarbon-substituted acids. Diverse vinyl iodides and bromides give rise to vinylation products in high efficiency under mild, operationally simple reaction conditions.

  16. Merging Photoredox and Nickel Catalysis: Decarboxylative Cross-Coupling of Carboxylic Acids with Vinyl Halides

    PubMed Central

    2015-01-01

    Decarboxylative cross-coupling of alkyl carboxylic acids with vinyl halides has been accomplished through the synergistic merger of photoredox and nickel catalysis. This new methodology has been successfully applied to a variety of α-oxy and α-amino acids, as well as simple hydrocarbon-substituted acids. Diverse vinyl iodides and bromides give rise to vinylation products in high efficiency under mild, operationally simple reaction conditions. PMID:25521443

  17. Enantioselective α-Vinylation of Aldehydes Via the Synergistic Combination of Copper and Amine Catalysis

    PubMed Central

    Skucas, Eduardas; MacMillan, David W. C.

    2012-01-01

    The enantioselective α-vinylation of aldehydes using vinyl iodonium triflate salts has been accomplished via the synergistic combination of copper and chiral amine catalysis. These mild catalytic conditions provide a direct route for the enantioselective construction of enolizable α-formyl vinylic stereocenters without racemization or olefin transposition. These high-value coupling adducts are readily converted into a variety of useful olefin synthons. PMID:22616631

  18. Tunable thermoresponsive pyrrolidone-based polymers from pyroglutamic acid, a bio-derived resource.

    PubMed

    Bhat, Rajani; Pietrangelo, Agostino

    2013-03-12

    A series of pyrrolidone-based polymers is prepared from pyroglutamic acid, a bio-derived resource. Polymers bearing simple alkoxy substituents (e.g., methoxy, ethoxy, and butoxy) are soluble in common organic solvents and possess glass transition temperatures that are dependent on the length of the alkoxy residue. Replacing these substituents with an ether moiety (CH3 OCH2 CH2 O-) affords a highly sensitive and reversible thermoresponsive polymer with a lower critical solution temperature (LCST) of 42 °C in water. Copolymers composed of repeat units bearing both the ether and simple alkoxy residues are found to exhibit LCSTs that are highly dependent on the nature of the hydrophobic alkoxy residue suggesting that the LCSTs of these polymers can be successfully tuned by simply tailoring the copolymer structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Partial molar volume of anionic polyelectrolytes in aqueous solution.

    PubMed

    Salamanca, Constain; Contreras, Martín; Gamboa, Consuelo

    2007-05-15

    In this work the partial molar volumes (V) of different anionic polyelectrolytes and hydrophobically modified polyelectrolytes (PHM) were measured. Polymers like polymaleic acid-co-styrene, polymaleic acid-co-1-olefin, polymaleic acid-co-vinyl-2-pyrrolidone, and polyacrylic acid (abbreviated as MAS-n, PA-n-K2, AMVP, and PAA, respectively) were employed. These materials were investigated by density measurements in highly dilute aqueous solutions. The molar volume results allow us to discuss the effect of the carboxylic groups and the contributions from the comonomeric principal chain. The PAA presents the smaller V, while the largest V value was for AMVP. The V of PHM shows a linear relationship with the number of methylene groups in the lateral chain. It is found that the magnitude of the contribution per methylene group decreases as the hydrophobic character of the environment increases.

  20. Highly filled biocomposites based on ethylene-vinyl acetate copolymer and wood flour

    NASA Astrophysics Data System (ADS)

    Shelenkov, P. G.; Pantyukhov, P. V.; Popov, A. A.

    2018-05-01

    Recently, there is a great interest in the world to biodegradable materials based on synthetic polymers in a composition with natural fillers. Highly filled polymer composite materials based on various grades of synthetic block copolymer of ethylene vinyl acetate with wood flour were under investigation. Five grades of ethylene-vinyl acetate copolymer differing in the content of vinyl acetate groups and a melt flow index were used in this work in order to find the best one for highly filled biocomposites. Wood flour content in biocomposites was 50, 60, 70 weight %. The rheological and physico-mechanical characteristics of the resulting biocomposites were studied.

  1. Gas Chromatographic Separation of an Acetylene Vinyl Fluoride-Difluoroethane Mixture on Triethylene Glycol and Silicone Oil,

    DTIC Science & Technology

    The purpose of the research was to study gas-chromatographic separation of impurities of acetylene and difluoroethane in vinyl fluoride obtained by...and difluoroethane . All the components are separated, and the criteria of separation of acetylene-vinyl fluoride and vinyl fluoride- difluoroethane

  2. 29 CFR 1910.1017 - Vinyl chloride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

  3. 29 CFR 1910.1017 - Vinyl chloride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

  4. 29 CFR 1910.1017 - Vinyl chloride.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: Cancer; central nervous system effects; liver effects; blood effects; and flammability. (iii) Employers..., whichever occurs first. (B) A continuous-monitoring and alarm system must be provided when concentrations of... system must be used to alert employees when vinyl chloride concentrations exceed the allowable...

  5. Bone Regeneration Using N-Methyl-2-pyrrolidone as an Enhancer for Recombinant Human Bone Morphogenetic Protein-2 in a Rabbit Sinus Augmentation Model

    PubMed Central

    Thoma, Daniel S.

    2017-01-01

    The aim of this study was to determine whether N-methyl-2-pyrrolidone (NMP) can decrease the dose of recombinant human bone morphogenetic protein-2 (rhBMP-2) in sinus augmentation of rabbits. In each of 15 rabbits, 2 sinuses were randomly grafted using 1 of 3 treatment modalities: (i) biphasic calcium phosphate (BCP; control), (ii) rhBMP-2-coated BCP (BMP), or (iii) rhBMP-2-coated BCP soaked in NMP solution (BMP/NMP). The rabbits were sacrificed 2 weeks postoperatively. Histologic and histomorphometric analyses were performed. Bone formation in all groups was predominantly located close to the access window and the lateral walls. Newly formed bone within the total augmented area (NBTA) was greatest in BMP/NMP (1.94 ± 0.69 mm2), followed by BMP (1.50 ± 0.72 mm2) and BCP (1.28 ± 0.52 mm2) (P > 0.05). In the center of the augmentation (NBROI_C) and the area close to the sinus membrane (NBROI_M), BMP/NMP produced the largest area of NB (NBROI_C: 0.10 ± 0.11 mm2; NBROI_M: 0.17 ± 0.08 mm2); the corresponding NB values for BCP were 0.05 ± 0.05 mm2 and 0.08 ± 0.09 mm2, respectively (P > 0.05 for all comparisons). The effect of NMP on bone regeneration was inconsistent between the specimens. Adding NMP as an adjunct to rhBMP-2-coated BCP produced inconsistent effects on bone regeneration, resulting in no significant benefit compared to controls. PMID:28680881

  6. Bone Regeneration Using N-Methyl-2-pyrrolidone as an Enhancer for Recombinant Human Bone Morphogenetic Protein-2 in a Rabbit Sinus Augmentation Model.

    PubMed

    Lim, Hyun-Chang; Thoma, Daniel S; Yoon, So-Ra; Cha, Jae-Kook; Lee, Jung-Seok; Jung, Ui-Won

    2017-01-01

    The aim of this study was to determine whether N-methyl-2-pyrrolidone (NMP) can decrease the dose of recombinant human bone morphogenetic protein-2 (rhBMP-2) in sinus augmentation of rabbits. In each of 15 rabbits, 2 sinuses were randomly grafted using 1 of 3 treatment modalities: (i) biphasic calcium phosphate (BCP; control), (ii) rhBMP-2-coated BCP (BMP), or (iii) rhBMP-2-coated BCP soaked in NMP solution (BMP/NMP). The rabbits were sacrificed 2 weeks postoperatively. Histologic and histomorphometric analyses were performed. Bone formation in all groups was predominantly located close to the access window and the lateral walls. Newly formed bone within the total augmented area (NB TA ) was greatest in BMP/NMP (1.94 ± 0.69 mm 2 ), followed by BMP (1.50 ± 0.72 mm 2 ) and BCP (1.28 ± 0.52 mm 2 ) ( P > 0.05). In the center of the augmentation (NB ROI_C ) and the area close to the sinus membrane (NB ROI_M ), BMP/NMP produced the largest area of NB (NB ROI_C : 0.10 ± 0.11 mm 2 ; NB ROI_M : 0.17 ± 0.08 mm 2 ); the corresponding NB values for BCP were 0.05 ± 0.05 mm 2 and 0.08 ± 0.09 mm 2 , respectively ( P > 0.05 for all comparisons). The effect of NMP on bone regeneration was inconsistent between the specimens. Adding NMP as an adjunct to rhBMP-2-coated BCP produced inconsistent effects on bone regeneration, resulting in no significant benefit compared to controls.

  7. A study of factors affecting properties of AM/AMPS/NVP terpolymeric microspheres prepared by inverse suspension polymerization

    NASA Astrophysics Data System (ADS)

    Jiang, J. F.; Zhao, Q.; Lin, M. Q.; Wang, Y. F.; Dang, S. M.; Sun, F. F.

    2015-12-01

    Terpolymeric microspheres were synthesized by the inverse suspension polymerization of functional monomers including AMPS, NVP, and AM. The morphology and size of the obtained microspheres were measured by scanning electron microscopy (SEM) and optical microscopy. Furthermore, the swelling performances of the obtained microspheres were measured with alaser particle analyzer (LPA), and the thermal stability of the microspheres obtained was measured by differential thermal analysis (DSC-TG) and high temperature experiments involving microsphere/water dispersion. The results revealed that the extreme value of the microsphere size distribution decreased from 280 μm to 20 μm as the stirring rate increased from 175 rpm to 500 rpm. At temperatures below 25°C, the maximum achieved swelling ratio of the microspheres was 21, and the thermal stability of the terpolymer microspheres was significantly higher than that of the dipolymer microspheres. The terpolymer/water dispersions were kept at 120°C for 19d before any damage was observed.

  8. Reusable recording medium based on MBPVA and vinyl acetate

    NASA Astrophysics Data System (ADS)

    John, Beena Mary; Ushamani, M.; Joseph, Rani; Sreekumar, K.; Sudha Kartha, C.

    2006-03-01

    A new photopolymerizable recording media is introduced based on poly (vinyl alcohol) and vinyl acetate sensitized with methylene blue. It is observed that this MBPVA/VAc system can be reused a number of times without significant decrease in diffraction efficiency. The PVA-VAc ratio was optimized at 2:1. Diffraction efficiency of 6.3% was obtained without any fixing at a dye concentration of 9.3?×?10-4?mol/l at an exposure of 750?mJ/cm2. The material is attractive on account of its reusability.

  9. Processable dodecylbenzene sulfonic acid (DBSA) doped poly(N-vinyl carbazole)-poly(pyrrole) for optoelectronic applications

    PubMed Central

    Hammed, W. A.; Rahman, M. S.; Mahmud, H. N. M. E.; Yahya, R.; Sulaiman, K.

    2017-01-01

    Abstract A soluble poly (n-vinyl carbazole)–polypyrrole (PNVC–Ppy) copolymer was prepared through oxidative chemical polymerization wherein dodecyl benzene sulfonic acid (DBSA) was used as a dopant to facilitate polymer-organic solvent interaction and ammonium persulfate (APS) was used as an oxidant. Compared with undoped PNVC–Ppy, the DBSA-doped PNVC–Ppy copolymer showed higher solubility in some selected organic solvents. The composition and structural characteristics of the DBSA-doped PNVC–Ppy were determined by Fourier transform infrared, ultraviolet–visible, and X-ray diffraction spectroscopic methods. Field emission scanning electron microscopic method was employed to observe the morphology of the DBSA-doped PNVC–Ppy copolymer. The electrical conductivity of the DBSA-doped PNVC–Ppy copolymer was measured at room temperature. The conductivity increased with increasing concentration of APS oxidant, and the highest conductivity was recorded at 0.004 mol/dm3 APS at a polymerization temperature of −5 °C. The increased conductivity can be explained by the extended half-life of pyrrole free radical at a lower temperature and a gradual increase in chain length over a prolonged time due to the slow addition of APS. Furthermore, the obtained soluble copolymer exhibits unique optical and thermal properties different from those of PNVC and Ppy. PMID:29491808

  10. Copper-Mediated SN2' Allyl-Alkyl and Allyl-Boryl Couplings of Vinyl Cyclic Carbonates.

    PubMed

    Miralles, Núria; Gómez, José Enrique; Kleij, Arjan W; Fernández, Elena

    2017-11-17

    A method for the copper-catalyzed borylmethylation and borylation of vinyl cyclic carbonates through an S N 2' mechanism is reported. These singular reactions involve selective S N 2' allylic substitutions with concomitant ring opening of the cyclic carbonate and with extrusion of CO 2 and formation of a useful hydroxyl functionality in a single step. The stereoselectivity of the homoallylic borylation and allylic borylation processes can be controlled, and synthetically useful unsaturated (E)-pent-2-ene-1,5-diols and (E)-but-2-ene-1,4-diols are accessed.

  11. Minor drug-resistant HIV type-1 variants in breast milk and plasma of HIV type-1-infected Ugandan women after nevirapine single-dose prophylaxis.

    PubMed

    Pilger, Daniel; Hauser, Andrea; Kuecherer, Claudia; Mugenyi, Kizito; Kabasinguzi, Rose; Somogyi, Sybille; Harms, Gundel; Kunz, Andrea

    2011-01-01

    Nevirapine single-dose (NVP-SD) reduces mother-to-child transmission of HIV type-1 (HIV-1), but frequently induces resistance mutations in the HIV-1 genome. Little is known about drug-resistant HIV-1 variants in the breast milk of women who have taken NVP-SD. Blood and breast milk samples of 39 HIV-1-infected Ugandan women were taken 6-12 weeks after NVP-SD intake. Samples were analysed by population sequencing and allele-specific real-time PCR (AS-PCR) with detection limits for NVP-resistant HIV-1 variants (K103N and Y181C) of < 1% of the total viral population. AS-PCR results for both plasma and breast milk were obtained for 19 women who constituted the final study group (HIV-1 subtype frequencies were A1 n = 11, D n = 5, G n = 2 and C n = 1). A total of 7 (37%) and 10 (53%) women carried NVP-resistant virus in breast milk and plasma, respectively. Overall, 71% (5/7) women with NVP-resistant HIV-1 in breast milk displayed >1 drug-resistant variant. Resistance in breast milk was higher at week 6 (6/13 samples [46%]) compared with week 12 (1/6 samples [17%]). In total, 10 drug-resistant populations harbouring the K103N and/or Y181C mutation were detected in the 19 breast milk samples; 7 (70%) were caused by resistant minorities (< 5% of the total HIV-1 population). In the four women with drug-resistant virus in both plasma and breast milk, the mutation patterns differed between the two compartments. Minor populations of drug-resistant HIV-1 were frequently found in breast milk of Ugandan women after exposure to NVP-SD. Further studies need to explore the role of minor drug-resistant variants in the postnatal transmission of (resistant) HIV-1.

  12. Aerobic mineralization of vinyl chlorides by a bacterium of the order Actinomycetales

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

    Phelps, T.J.; Malachowsky, K.; Schram, R.M.

    1991-04-01

    A gram-positive branched bacterium isolated from a trichloroethylene-degrading consortium mineralized vinyl chloride in growing cultures and cell suspensions. Greater than 67% of the (1,2-{sup 14}C)vinyl chloride was mineralized to carbon dioxide, with approximately 10% of the radioactivity appearing in {sup 14}C-aqueous-phase products.

  13. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acids, C10-13 - branched, vinyl... Specific Chemical Substances § 721.9965 Fatty acids, C10-13 - branched, vinyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as fatty...

  14. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty acids, C10-13 - branched, vinyl... Specific Chemical Substances § 721.9965 Fatty acids, C10-13 - branched, vinyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as fatty...

  15. Field and laboratory evidence for intrinsic biodegradation of vinyl chloride contamination in a Fe(III)-reducing aquifer

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Wilson, J.T.

    1998-01-01

    Intrinsic bioremediation of chlorinated ethenes in anaerobic aquifers previously has not been considered feasible, due, in large part, to 1) the production of vinyl chloride during microbial reductive dechlorination of higher chlorinated contaminants and 2) the apparent poor biodegradability of vinyl chloride under anaerobic conditions. In this study, a combination of field geochemical analyses and laboratory radiotracer ([1,2-14C] vinyl chloride) experiments was utilized to assess the potential for intrinsic biodegradation of vinyl chloride contamination in an Fe(III)-reducing, anaerobic aquifer. Microcosm experiments conducted under Fe(III)-reducing conditions with material from the Fe(III)-reducing, chlorinated-ethene contaminated aquifer demonstrated significant oxidation of [1,2-14C] vinyl chloride to 14CO2 with no detectable production of ethene or other reductive dehalogenation products. Rates of degradation derived from the microcosm experiments (0.9-1.3% d-1) were consistent with field-estimated rates (0.03-0.2% d-1) of apparent vinyl chloride degradation. Field estimates of apparent vinyl chloride biodegradation were calculated using two distinct approaches; 1) a solute dispersion model and 2) a mass balance assessment. These findings demonstrate that degradation under Fe(III) reducing conditions can be an environmentally significant mechanism for intrinsic bioremediation of vinyl chloride in anaerobic ground-water systems.

  16. 29 CFR 1926.1117 - Vinyl chloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Vinyl chloride. 1926.1117 Section 1926.1117 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... chloride. Note: The requirements applicable to construction work under this section are identical to those...

  17. Liver Hypertrophy After Percutaneous Portal Vein Embolization: Comparison of N-Butyl-2-Cyanocrylate Versus Sodium Acrylate-Vinyl Alcohol Copolymer Particles in a Swine Model

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

    Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Theocharis, Stamatis, E-mail: theocharis@ath.forthnet.gr; Ptohis, Nikolaos, E-mail: nikptohis@yahoo.gr

    2011-10-15

    Purpose: Percutaneous portal vein embolization (PPVE) induces hypertrophy of the future liver remnant before hepatic resection. The ideal embolic material has not yet been determined. We compared N-butyl-2-cyanocrylate (NBCA) with sodium acrylate-vinyl alcohol copolymer particles using a swine model. Materials and Methods: Twelve pigs underwent PPVE. Six pigs (group A) were embolized with NBCA, and 6 pigs (group B) were embolized with sodium acrylate-vinyl alcohol copolymer particles. Computed tomographic volumetry of the embolized lobe (EL) and the nonembolized lobe (NEL), along with liver function tests, was performed before and at 14 and 28 days after embolization. Tissue samples from bothmore » lobes were taken 14 and 28 days after PPVE. Results: NEL-volume and NEL-ratio increases were significantly higher in group A at 14 and 28 days after PPVE (78 and 52% and 91 and 66%, respectively) than in group B (32 and 12% and 28 and 10%, respectively) (p < 0.05). Percent change of the EL-volume was significantly higher for group A at 28 days after PPVE. No statistically significant difference was found between the groups regarding hepatocyte proliferation on the NEL and apoptosis on the EL at both time intervals. Conclusion: PPVE using NBCA is more efficient and causes more NEL hypertrophy than microspheres.« less

  18. Anion effects on anti-microbial activity of poly[1-vinyl-3-(2-sulfoethyl imidazolium betaine)].

    PubMed

    Garg, Godawari; Chauhan, Ghanshyam S; Gupta, Reena; Ahn, J-H

    2010-04-01

    Recent investigations in the anti-microbial properties of the functional polymers are predominantly focused on the structure of the cationic moieties. In the present study, we investigated that the nature of the anion present in polysulfobetaines affects activity against certain microorganisms and their anti-microbial properties have been rationalized in terms of the structure-activity relationship. Vinyl imidazolium-based polysulfobetaines were prepared by the quaternization of poly(N-vinyl imidazole) with sodium salt of 2-bromo ethanesulfonic acid. The bromide counter anion of the resulting polymer was exchanged with different anions to generate a series of polymers. These were characterized by FTIR, DSC, XRD, SEM, elemental analysis (C, H, N and S) and viscosity measurements. The anti-microbial activity studies were carried against three fungi (Aspergillus niger, Byssochlamys fulva and Mucor circenelliods) and two bacteria (Bacillus coagulans BTS-3 and Pseudomonas aeruginosa BTS-2). The nature of the anion affects the structure of polysulfobetaine by realignment of polymer chains. The anion-dependent anti-microbial properties of polysulfobetaines result from the interaction of the microbes at the polymer interface. Copyright 2009 Elsevier Inc. All rights reserved.

  19. Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach

    PubMed Central

    Saeb, Mohammad Reza; Rezaee, Babak; Shadman, Alireza; Formela, Krzysztof; Ahmadi, Zahed; Hemmati, Farkhondeh; Kermaniyan, Tayebeh Sadat; Mohammadi, Yousef

    2017-01-01

    Abstract Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins. PMID:29491797

  20. Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach.

    PubMed

    Saeb, Mohammad Reza; Rezaee, Babak; Shadman, Alireza; Formela, Krzysztof; Ahmadi, Zahed; Hemmati, Farkhondeh; Kermaniyan, Tayebeh Sadat; Mohammadi, Yousef

    2017-01-01

    Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins.

  1. Vinyl Sulfones as Antiparasitic Agents and a Structural Basis for Drug Design*

    PubMed Central

    Kerr, Iain D.; Lee, Ji H.; Farady, Christopher J.; Marion, Rachael; Rickert, Mathias; Sajid, Mohammed; Pandey, Kailash C.; Caffrey, Conor R.; Legac, Jennifer; Hansell, Elizabeth; McKerrow, James H.; Craik, Charles S.; Rosenthal, Philip J.; Brinen, Linda S.

    2009-01-01

    Cysteine proteases of the papain superfamily are implicated in a number of cellular processes and are important virulence factors in the pathogenesis of parasitic disease. These enzymes have therefore emerged as promising targets for antiparasitic drugs. We report the crystal structures of three major parasite cysteine proteases, cruzain, falcipain-3, and the first reported structure of rhodesain, in complex with a class of potent, small molecule, cysteine protease inhibitors, the vinyl sulfones. These data, in conjunction with comparative inhibition kinetics, provide insight into the molecular mechanisms that drive cysteine protease inhibition by vinyl sulfones, the binding specificity of these important proteases and the potential of vinyl sulfones as antiparasitic drugs. PMID:19620707

  2. Environmentally Friendly Bio-Based Vinyl Ester Resins for Military Composite Structures

    DTIC Science & Technology

    2008-12-01

    composites, fatty acid , vinyl ester 9. Distribution $tatement (requr’iedl lsmanuscript subjectto export control? E ruo I yes Circfe appropriate l tter and...resins is to replace some or all of the styrene with fatty acid -based monomers. These fatty acid vinyl ester resins allow for the formulation of high...validation studies have been performed, showing that the fatty acid -based resins have sufficient, modulus, strength, glass transition temperature, and

  3. High Performance Fatty Acid-Based Vinyl Ester Resin for Liquid Molding

    DTIC Science & Technology

    2007-07-01

    High Performance Fatty Acid -Based Vinyl Ester Resin for Liquid Molding by Xing Geng, John J. La Scala, James M. Sands, and Giuseppe R...it to the originator. Army Research Laboratory Aberdeen Proving Ground, MD 21005-5069 ARL-RP-184 July 2007 High Performance Fatty Acid ...CONTRACT NUMBER 5b. GRANT NUMBER 4. TITLE AND SUBTITLE High Performance Fatty Acid -Based Vinyl Ester Resin for Liquid Molding 5c. PROGRAM

  4. Aerobic mineralization of vinyl chloride by a bacterium of the order Actinomycetales.

    PubMed Central

    Phelps, T J; Malachowsky, K; Schram, R M; White, D C

    1991-01-01

    A gram-positive branched bacterium isolated from a trichloroethylene-degrading consortium mineralized vinyl chloride in growing cultures and cell suspensions. Greater than 67% of the [1,2-14C]vinyl chloride was mineralized to carbon dioxide, with approximately 10% of the radioactivity appearing in cell biomass and another 10% appearing in 14C-aqueous-phase products. PMID:1905522

  5. Scientists Toast the Discovery of Vinyl Alcohol in Interstellar Space

    NASA Astrophysics Data System (ADS)

    2001-10-01

    Astronomers using the National Science Foundation's 12 Meter Telescope at Kitt Peak, AZ, have discovered the complex organic molecule vinyl alcohol in an interstellar cloud of dust and gas near the center of the Milky Way Galaxy. The discovery of this long-sought compound could reveal tantalizing clues to the mysterious origin of complex organic molecules in space. Vinyl Alcohol and its fellow isomers "The discovery of vinyl alcohol is significant," said Barry Turner, a scientist at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Va., "because it gives us an important tool for understanding the formation of complex organic compounds in interstellar space. It may also help us better understand how life might arise elsewhere in the Cosmos." Vinyl alcohol is an important intermediary in many organic chemistry reactions on Earth, and the last of the three stable members of the C2H4O group of isomers (molecules with the same atoms, but in different arrangements) to be discovered in interstellar space. Turner and his colleague A. J. Apponi of the University of Arizona's Steward Observatory in Tucson detected the vinyl alcohol in Sagittarius B -- a massive molecular cloud located some 26,000 light-years from Earth near the center of our Galaxy. The astronomers were able to detect the specific radio signature of vinyl alcohol during the observational period of May and June of 2001. Their results have been accepted for publication in the Astrophysical Journal Letters. Of the approximately 125 molecules detected in interstellar space, scientists believe that most are formed by gas-phase chemistry, in which smaller molecules (and occasionally atoms) manage to "lock horns" when they collide in space. This process, though efficient at creating simple molecules, cannot explain how vinyl alcohol and other complex chemicals are formed in detectable amounts. For many years now, scientists have been searching for the right mechanism to explain how the building

  6. Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

    PubMed

    Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

    2011-12-06

    The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

  7. Separator Membrane from Crosslinked Poly(Vinyl Alcohol) and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride)

    PubMed Central

    Rohatgi, Charu Vashisth; Dutta, Naba K.; Choudhury, Namita Roy

    2015-01-01

    In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA) with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MA). Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity), thermal and electrochemical properties using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications. PMID:28347019

  8. A modification of the Hammett equation for predicting ionisation constants of p-vinyl phenols.

    PubMed

    Sipilä, Julius; Nurmi, Harri; Kaukonen, Ann Marie; Hirvonen, Jouni; Taskinen, Jyrki; Yli-Kauhaluoma, Jari

    2005-01-01

    Currently there are several compounds used as drugs or studied as new chemical entities, which have an electron withdrawing group connected to a vinylic double bond in a phenolic or catecholic core structure. These compounds share a common feature--current computational methods utilizing the Hammett type equation for the prediction of ionisation constants fail to give accurate prediction of pK(a)'s for compounds containing the vinylic moiety. The hypothesis was that the effect of electron-withdrawing substituents on the pK(a) of p-vinyl phenols is due to the delocalized electronic structure of these compounds. Thus, this effect should be additive for multiple substituents attached to the vinylic double bond and quantifiable by LFER-based methods. The aim of this study was to produce an improved equation with a reduced tendency to underestimate the effect of the double bond on the ionisation of the phenolic hydroxyl. To this end a set of 19 para-substituted vinyl phenols was used. The ionisation constants were measured potentiometrically, and a training set of 10 compounds was selected to build a regression model (r2 = 0.987 and S.E. = 0.09). The average error with an external test set of six compounds was 0.19 for our model and 1.27 for the ACD-labs 7.0. Thus, we have been able to significantly improve the existing model for prediction of the ionisation constants of substituted p-vinyl phenols.

  9. Preparation of polymethacrylic acid-grafted HEMA/PVP microspheres and preliminary study on basic protein adsorption.

    PubMed

    Gao, Baojiao; Hu, Hongyan; Guo, Jianfeng; Li, Yanbin

    2010-06-01

    The crosslinked copolymeric microspheres (HEMA/NVP) of N-vinylpyrrolidone (NVP) and 2-hydroxyethyl methacrylate (HEMA) were prepared using inverse suspension polymerization method. Subsequently, the reaction of methacryloyl chloride with the hydroxyl groups on the surfaces of HEMA/NVP microspheres was performed, leading to the introduction of polymerisable double bonds onto the surfaces of microspheres HEMA/NVP. Afterward, methacrylic acid was allowed to be graft-polymerized on microspheres HEMA/NVP in the manner of "grafting from", resulting in the grafted microspheres PMAA-HEMA/NVP. The grafted microspheres PMAA-HEMA/NVP were fully characterized with several means. The graft-polymerization of MAA on microspheres HEMA/NVP was studied in detail, and the optimal reaction conditions were determined. Thereafter, the adsorption property of the grafted microspheres PMAA-HEMA/NVP for lysozyme as a basic protein model was preliminarily examined to explore the feasibility of removing deleterious basic protein such as density lipoprotein from blood. The experimental results indicate that the PMAA grafting degree on microspheres HEMA/NVP is limited because an enwinding polymer layer as a kinetic barrier on the surfaces of HEMA/NVP microspheres will be formed during the graft-polymerization, and block the graft-polymerization. In order to enhance PMAA grafting degree, reaction temperature, monomer concentration and the used amount of initiator should be effectively controlled. The experimental results also reveal that the grafted microspheres PMAA-HEMA/NVP possess very strong adsorption ability for lysozyme by right of strong electrostatic interaction. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Hepatocyte spheroids as a competent in vitro system for drug biotransformation studies: nevirapine as a bioactivation case study.

    PubMed

    Pinheiro, Pedro F; Pereira, Sofia A; Harjivan, Shrika G; Martins, Inês L; Marinho, Aline T; Cipriano, Madalena; Jacob, Cristina C; Oliveira, Nuno G; Castro, Matilde F; Marques, M Matilde; Antunes, Alexandra M M; Miranda, Joana P

    2017-03-01

    The development of metabolically competent in vitro models is of utmost importance for predicting adverse drug reactions, thereby preventing attrition-related economical and clinical burdens. Using the antiretroviral drug nevirapine (NVP) as a model, this work aimed to validate rat hepatocyte 3D spheroid cultures as competent in vitro systems to assess drug metabolism and bioactivation. Hepatocyte spheroids were cultured for 12 days in a stirred tank system (3D cultures) and exposed to equimolar dosages of NVP and its two major Phase I metabolites, 12-OH-NVP and 2-OH-NVP. Phase I NVP metabolites were detected in the 3D cultures during the whole culture time in the same relative proportions reported in in vivo studies. Moreover, the modulation of SULT1A1 activity by NVP and 2-OH-NVP was observed for the first time, pointing their synergistic effect as a key factor in the formation of the toxic metabolite (12-sulfoxy-NVP). Covalent adducts formed by reactive NVP metabolites with N-acetyl-L-cysteine and bovine serum albumin were also detected by high-resolution mass spectrometry, providing new evidence on the relative role of the reactive NVP metabolites, 12-sulfoxy-NVP, and NVP quinone methide, in toxicity versus excretion pathways. In conclusion, these results demonstrate the validity of the 3D culture system to evaluate drug bioactivation, enabling the identification of potential biomarkers of bioactivation/toxicity, and providing new evidence to the mechanisms underlying NVP-induced toxic events. This model, integrated with the analytical strategies described herein, is of anticipated usefulness to the pharmaceutical industry, as an upstream methodology for flagging drug safety alerts in early stages of drug development.

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

    Takigami, S.; Maeda, Y.; Nakamura, Y.

    The diffusive permeability of potassium chloride, urea, and uric acid through cellophanes grafted with acrylamide, acrylic acid, styrene, and N-vinyl-2-pyrrolidone by ..gamma..-ray irradiation was studied. The diffusive permeability coefficients of the permeants through the grafted cellophanes were increased with increase in hydration of the grafted membranes, except for the permeation of potassium chloride through cellophanes grafted with acrylic acid. The permeation of potassium chloride, urea, and uric acid through the various grafted cellophanes is explained by the free volume concept of homogeneously water-swollen membranes. However, the behavior of the permeation of potassium chloride through cellophane grafted with acrylic acid deviatedmore » from that of nonionic membranes because of the contribution of the electrical interaction between electrolyte and charge of the membrane. 4 figures, 3 tables.« less

  12. Protein valves prepared by click reaction grafting of poly(N-isopropylacrylamide) to electrospun poly(vinyl chloride) fibrous membranes

    NASA Astrophysics Data System (ADS)

    Guo, Jian-Wei; Lin, Zhen-Yu; Chang, Chi-Jung; Lu, Chien-Hsing; Chen, Jem-Kun

    2018-05-01

    In this study, poly(vinyl chloride) (PVC) was electrospun into fibrous membranes and then reacted with NaN3 to generate azido-terminated PVC fibrous membranes. A propargyl-terminated poly(N-isopropylacrylamide) (PNIPAAm) was also synthesized and then grafted, through click reactions, onto the azido-terminated PVC fiber surface. Protrusion-, scale-, and joint-like structures of the PNIPAAm grafts on the PVC fibers were formed upon increasing the molecular weight of the PNIPAAm grafts. The PNIPAAm-grafted PVC fibrous mats exhibited completely wetted surfaces at 25 °C because of their high roughness. The static water contact angle of the PNIPAAm-grafted PVC fibrous mats reached 140° when the temperature was increased to 45 °C. This thermoresponsive behavior was significantly greater than that of the PNIPAAm grafted on a flat surface. Temperature-responsive membranes were constructed having a pore size of 1.38 μm and applied as protein valves to block and release an antibody (fluorescein-conjugated AffiniPure goat anti-rabbit IgG). At 25 °C, the collection efficiency remained at 94% for antibody concentrations up to 60 ng/L. As the temperature increased to 45 °C, the collection efficiency decreased abruptly, to 4%, when the antibody concentration was greater than 20 ng/L. Accordingly, this system of PNIPAAm-grafted PVC fibers functioned as a protein valve allowing the capture and concentration of proteins.

  13. Improved adhesion performances of aramid fibers with vinyl epoxy via supercritical carbon dioxide modification

    NASA Astrophysics Data System (ADS)

    Qin, M. L.; Kong, H. J.; Yu, M. H.; Teng, C. Q.

    2017-06-01

    In this paper, aramid fibers were treated under supercritical carbon dioxide (SCCO2) with isocyanate terminated liquid nitrile rubber to improve the adhesion performances of vinyl epoxy composites. The interfacial shear strength (IFSS) of vinyl epoxy composites was investigated by micro-bond test. The results indicate that the surface modification of aramid fibers in SCCO2 was an efficient method to increase the adhesion performances between fibers and vinyl epoxy. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were adopted to investigate the surface structure and composition of aramid fibers. The flexural strength and interlaminar shear strength (ILSS) of treated aramid fibers/vinyl epoxy composites was improved by 18.1% and 28.9% compared with untreated aramid fibers, respectively. Furthermore, the fractured surfaces of the composites were observed by SEM, which showed that the interfacial adhesion of composites has been remarkably changed.

  14. Preparation of vinyl acetate grafted natural rubber by irradiation method

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

    Porntrairat, A.; Pattamaprom, C.

    Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content weremore » measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.« less

  15. 76 FR 76766 - Standard on Vinyl Chloride; Extension of the Office of Management and Budget's (OMB) Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ...] Standard on Vinyl Chloride; Extension of the Office of Management and Budget's (OMB) Approval of... requirements specified in the Standard on Vinyl Chloride (29 CFR 1910.1017). DATES: Comments must be submitted... of the collection of information requirements contained in the Vinyl Chloride (VC) Standard. (A...

  16. A Torquoselective Extrusion of Isoxazoline N-Oxides. Application to the Synthesis of Aryl Vinyl and Divinyl Ketones for Nazarov Cyclization

    PubMed Central

    Canterbury, Daniel P.; Herrick, Ildiko R.; Um, Joann; Houk, K. N.; Frontier, Alison J.

    2009-01-01

    A mild, convenient reaction sequence for the synthesis of Nazarov cyclization substrates is described. The [3+2] dipolar cycloaddition of a nitrone and an electron-deficient alkyne gives an isolable isoxazoline intermediate, which upon oxidation undergoes stereoselective extrusion of nitrosomethane to give aryl vinyl or divinyl ketones. PMID:20161228

  17. Synthesis of icosahedral gold nanocrystals: a thermal process strategy.

    PubMed

    Zhou, Min; Chen, Shenhao; Zhao, Shiyong

    2006-03-16

    We demonstrate a one-step thermal process route to the synthesis of icosahedral gold nanocrystals. By regulating the concentrations of poly(vinyl pyrrolidone) (PVP) and HAuCl4 or changing the temperature, we can readily access the shapes of icosahedral nanocrystals with good uniformity. These gold nanostructures, with unique geometrical shapes, might find use in areas that include photonics, optoelectronics, and optical sensing. We also observed that these gold nanocrystals have a strong tendency to be immobilized spontaneously on the glass substrate.

  18. Synthesis of aryl azides and vinyl azides via proline-promoted CuI-catalyzed coupling reactions.

    PubMed

    Zhu, Wei; Ma, Dawei

    2004-04-07

    The coupling reaction of aryl halides or vinyl iodide with sodium azide under catalysis of CuI/L-proline works at relatively low temperature to provide aryl azides or vinyl azides in good to excellent yields.

  19. 21 CFR 177.1980 - Vinyl chloride-propylene copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... grams of granular sodium peroxide, 0.1 gram of powdered starch, and 0.02 gram potassium nitrate; and the... provisions of this section are not applicable to vinyl chloride-propylene copolymers used in food-packaging...

  20. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

    1998-02-17

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

  1. Development and application of an LC-MS/MS method for the detection of the vinyl chloride-induced DNA adduct N2,3-ethenoguanine in tissues of adult and weanling rats following the exposure to [13C2]-VC

    EPA Science Inventory

    In the 1970s exposure to vinyl chloride (VC) was shown to cause liver angiosarcoma in VC workers. We have developed a new LC-MS/MS method for analyzing the promutagenic DNA adduct N2,3-ethenoguanine and have applied this to DNA from tissues of both adult and weanling rats expose...

  2. Process for the preparation of vinyl acetate

    DOEpatents

    Tustin, Gerald Charles; Zoeller, Joseph Robert; Depew, Leslie Sharon

    1998-01-01

    This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

  3. Vinylation of nitro-substituted indoles, quinolinones, and anilides with grignard reagents.

    PubMed

    Egris, Riccardo; Villacampa, Mercedes; Menéndez, J Carlos

    2009-10-19

    The reaction of vinyl Grignard reagents with o-methoxynitroarenes containing an electron-releasing substituent para to the nitro group proceeds through a pathway that is different from the initially expected Bartoli indole synthesis. Thus, instead of giving fused indole derivatives, these reactions provide a very mild and efficient new procedure for the synthesis of synthetically relevant aromatic systems containing an o-nitrovinyl moiety, such as 5-nitro-4-vinylindoles, 6-nitro-7-vinylindoles, 6-nitro-5-vinyl-2(1H)quinolinones, and 4-nitro-3-vinylanilines.

  4. 21 CFR 177.1980 - Vinyl chloride-propylene copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... contents of the cup are added 3.5 grams of granular sodium peroxide, 0.1 gram of powdered starch, and 0.02... applicable to vinyl chloride-propylene copolymers used in food-packaging adhesives complying with § 175.105...

  5. 21 CFR 177.1980 - Vinyl chloride-propylene copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... contents of the cup are added 3.5 grams of granular sodium peroxide, 0.1 gram of powdered starch, and 0.02... applicable to vinyl chloride-propylene copolymers used in food-packaging adhesives complying with § 175.105...

  6. Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride).

    PubMed

    Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

    2013-01-02

    Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively.

  7. Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride)

    PubMed Central

    Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

    2012-01-01

    Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively. PMID:24958543

  8. Identification of NVP-BKM120 as a Potent, Selective, Orally Bioavailable Class I PI3 Kinase Inhibitor for Treating Cancer.

    PubMed

    Burger, Matthew T; Pecchi, Sabina; Wagman, Allan; Ni, Zhi-Jie; Knapp, Mark; Hendrickson, Thomas; Atallah, Gordana; Pfister, Keith; Zhang, Yanchen; Bartulis, Sarah; Frazier, Kelly; Ng, Simon; Smith, Aaron; Verhagen, Joelle; Haznedar, Joshua; Huh, Kay; Iwanowicz, Ed; Xin, Xiaohua; Menezes, Daniel; Merritt, Hanne; Lee, Isabelle; Wiesmann, Marion; Kaufman, Susan; Crawford, Kenneth; Chin, Michael; Bussiere, Dirksen; Shoemaker, Kevin; Zaror, Isabel; Maira, Sauveur-Michel; Voliva, Charles F

    2011-10-13

    Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein we describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines where the pharmacokinetic properties were improved by modulating the electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned further by modification of the 4-position substituent. The resulting 2,4-bismorpholino 6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modulation in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of cancer.

  9. Identification of NVP-BKM120 as a Potent, Selective, Orally Bioavailable Class I PI3 Kinase Inhibitor for Treating Cancer

    PubMed Central

    2011-01-01

    Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein we describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines where the pharmacokinetic properties were improved by modulating the electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned further by modification of the 4-position substituent. The resulting 2,4-bismorpholino 6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modulation in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of cancer. PMID:24900266

  10. Stereoselective Formation of Trisubstituted Vinyl Boronate Esters by the Acid-Mediated Elimination of α-Hydroxyboronate Esters

    PubMed Central

    2015-01-01

    The copper-catalyzed diboration of ketones followed by an acid-catalyzed elimination leads to the formation of 1,1-disubstituted and trisubstituted vinyl boronate esters with moderate to good yields and selectivity. Addition of tosic acid to the crude diboration products provides the corresponding vinyl boronate esters upon elimination. The trisubstituted vinyl boronate esters are formed as the (Z)-olefin isomer, which was established by subjecting the products to a Suzuki–Miyaura coupling reaction to obtain alkenes of known geometry. PMID:24915498

  11. One-Pot Catalytic Enantio- and Diastereoselective Syntheses of anti-, syn-cis-Disubstituted, and syn-Vinyl Cyclopropyl Alcohols

    PubMed Central

    Kim, Hun Young; Salvi, Luca; Carroll, Patrick J.; Walsh, Patrick J.

    2009-01-01

    Highly enantio- and diastereoselective methods for the synthesis of a variety of cyclopropyl alcohols are reported. These methods represent the first one-pot approaches to syn-vinyl cyclopropyl alcohols, syn-cis-disubstituted cyclopropyl alcohols, and anti-cyclopropyl alcohols from achiral precursors. The methods begin with enantioselective C–C bond formations promoted by a MIB-based zinc catalyst to generate allylic alkoxide intermediates. The intermediates are then subjected to in situ alkoxide-directed cyclopropanation to provide cyclopropyl alcohols. In the synthesis of vinyl cyclopropyl alcohols, hydroboration of enynes is followed by transmetalation of the resulting dienylborane to zinc to provide dienylzinc reagents. Enantioselective addition to aldehydes generates the requisite dienyl zinc alkoxides, which are then subjected to in situ cyclopropanation to furnish vinyl cyclopropyl alcohols. Cyclopropanation occurs at the double bond allylic to the alkoxide. Using this method, syn-vinylcyclopropyl alcohols are obtained in 65–85% yield, 76–93% ee, and >19:1 dr. To prepare anti-cyclopropanols, enantioselective addition of alkylzinc reagents to conjugated enals provides allylic zinc alkoxides. Because direct cyclopropanation provides syn-cyclopropyl alcohols, the intermediate allylic alkoxides were treated with TMSCl/Et3N to generate intermediate silyl ethers. In situ cyclopropanation of the allylic silyl ether resulted in cyclopropanation to form the anti-cyclopropyl silyl ether. Workup with TBAF affords the anti-cyclopropyl alcohols in one-pot in 60–82% yield, 89–99% ee, and ≥10:1 dr. For the synthesis of cis-disubstituted cyclopropyl alcohols, in situ generated (Z)-vinyl zinc reagents were employed in asymmetric addition to aldehydes to generate (Z)-allylic zinc alkoxides. In situ cyclopropanation provides syn-cis-disubstituted cyclopropyl alcohols in 42–70% yield, 88–97% ee, and >19:1 dr. These one-pot procedures enable the synthesis of a

  12. Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

    NASA Astrophysics Data System (ADS)

    Xiang, Feng; Gan, Weiping

    2018-01-01

    In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.

  13. 21 CFR 177.1960 - Vinyl chloride-hexene-1 copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... determined by any suitable analytical procedure of generally accepted applicability. (ii) Inherent viscosity... D1243-79, “Standard Test Method for Dilute Solution Viscosity of Vinyl Chloride Polymers,” which is...

  14. Characterization of Vinyl Ester Composites Filled with Carbonized Jatropha seed shell: effect of accelerated weathering

    NASA Astrophysics Data System (ADS)

    Sri Aprilia, N. A.; Khalil, H. P. S. Abdul; Amin, Amri; Meurah Rosnelly, Cut; Fathanah, Ummi; Mariana

    2018-05-01

    The effect of accelerated weathering test of carbonized jatropha seed shell filled vinyl ester biocomposites was investigated. In this study, four loading of carbonized jatropha seed shell and one without loading of vinyl ester biocomposites were used. The samples exposure at several circles time in QUV chamber. The durability of vinyl ester biocomposites filled carbonized jatropha seed shell changes in mechanical properties and weight loss during exposure in UV and condensation. The tensile test and flexural indicated decrease with increasing of carbonized jatropha seed shell loading. The SEM fracture surface of biocomposites looks rough and some carbonized out of the matrix.

  15. An Evaluation of Fracture Toughness of Vinyl Ester Composites Cured under Microwave Conditions

    NASA Astrophysics Data System (ADS)

    Ku, H.; Chan, W. L.; Trada, M.; Baddeley, D.

    2007-12-01

    The shrinkage of vinyl ester particulate composites has been reduced by curing the resins under microwave conditions. The reduction in the shrinkage of the resins by microwaves will enable the manufacture of large vinyl ester composite items possible (H.S. Ku, G. Van Erp, J.A.R. Ball, and S. Ayers, Shrinkage Reduction of Thermoset Fibre Composites during Hardening using Microwaves Irradiation for Curing, Proceedings, Second World Engineering Congress, Kuching, Malaysia, 2002a, 22-25 July, p 177-182; H.S. Ku, Risks Involved in Curing Vinyl Ester Resins Using Microwaves Irradiation. J. Mater. Synth. Proces. 2002b, 10(2), p 97-106; S.H. Ku, Curing Vinyl Ester Particle Reinforced Composites Using Microwaves. J. Comp. Mater., (2003a), 37(22), p 2027-2042; S.H. Ku and E. Siores, Shrinkage Reduction of Thermoset Matrix Particle Reinforced Composites During Hardening Using Microwaves Irradiation, Trans. Hong Kong Inst. Eng., 2004, 11(3), p 29-34). In tensile tests, the yield strengths of samples cured under microwave conditions obtained are within 5% of those obtained by ambient curing; it is also found that with 180 W microwave power, the tensile strengths obtained for all duration of exposure to microwaves are also within the 5% of those obtained by ambient curing. While, with 360 W microwave power, the tensile strengths obtained for all duration of exposure to microwaves are 5% higher than those obtained by ambient curing. Whereas, with 540 W microwave power, the tensile strengths obtained for most samples are 5% below those obtained by ambient curing (H. Ku, V.C. Puttgunta, and M. Trada, Young’s Modulus of Vinyl Ester Composites Cured by Microwave Irradiation: Preliminary Results, J. Electromagnet. Waves Appl., 2007, 20(14), p. 1911-1924). This project, using 33% by weight fly ash reinforced vinyl ester composite [VE/FLYSH (33%)], is to further investigate the difference in fracture toughness between microwave cured vinyl ester particulate composites and those cured

  16. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

    NASA Astrophysics Data System (ADS)

    Aydınlı, Bahattin; Tin c̡er, Teoman

    2001-10-01

    Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60°C and they became clearer at a higher grafting level. In the second run of DSC some Tg values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

  17. Pressure and Temperature Dependence of the Reaction of Vinyl Radical with Ethylene

    NASA Technical Reports Server (NTRS)

    Ismail, Huzeifa; Goldsmith, C. Franklin; Abel, Paul R.; Howe, Pui-Teng; Fahr, Askar; Halpern, Joshua B.; Jusinski, Leonard E.; Georgievskii, Yuri; Taatjes, Craig A.; Green, William H.

    2007-01-01

    This work reports measurements of absolute rate coefficients and Rice-Ramsperger-Kassel-Marcus (RRKM) master equation simulations of the C2H3 + C2H4 reaction. Direct kinetic studies were performed over a temperature range of 300-700 K and pressures of 20 and 133 mbar. Vinyl radicals (H2C=CH) were generated by laser photolysis of vinyl iodide (C2H31) at 266 nm, and time-resolved absorption spectroscopy was used to probe vinyl radicals through absorption at 423.2 nm. Measurements at 20 mbar are in good agreement with previous determinations at higher temperature. A weighted three-parameter Arrhenius fit to the experimental rate constant at 133 mbar, with the temperature exponent fixed, gives k = (7 +/- 1) x 10(exp -l4) cu cm/molecule/s (T/298 K)(exp 2) exp[-(1430 +/- 70) K/T]. RRKM master equation simulations, based on G3 calculations of stationary points on the C4H7 potential energy surface, were carried out to predict rate coefficients and product branching fractions. The predicted branching to 1-methylallyl product is relatively small under the conditions of the present experiments but increases as the pressure is lowered. Analysis of end products of 248 nm photolysis of vinyl iodide/ethylene mixtures at total pressures between 27 and 933 mbar provides no direct evidence for participation of I -methylallyl.

  18. 40 CFR 721.10481 - Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with silica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Siloxanes and Silicones, Me vinyl... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10481 Siloxanes and Silicones, Me... uses subject to reporting. (1) The chemical substance identified as Siloxanes and Silicones, Me vinyl...

  19. 40 CFR 721.10481 - Siloxanes and Silicones, Me vinyl, hydroxy-terminated, reaction products with silica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Siloxanes and Silicones, Me vinyl... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10481 Siloxanes and Silicones, Me... uses subject to reporting. (1) The chemical substance identified as Siloxanes and Silicones, Me vinyl...

  20. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Emission standard for ethylene... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride...

  1. “Click, Click, Cyclize”: A DOS Approach to Sultams Utilizing Vinyl Sulfonamide Linchpins

    PubMed Central

    Zhou, Aihua; Rayabarapu, Dinesh; Hanson, Paul R.

    2009-01-01

    A diversity-oriented synthesis (DOS) strategy termed “Click, Click, Cyclize” is reported. This approach relies on functional group (FG) pairing between a vinyl sulfonamide and an array of functional groups to synthesize skeletally diverse sultams. Several FG pairing pathways on central tertiary vinyl sulfonamide linchpins have been developed including intramolecular Heck, aza-Michael, ring-closing enyne metathesis, Pauson—Khand, and chemoselective oxidation/Baylis—Hillman reactions. PMID:19115841

  2. Injectable biomaterials for minimally invasive orthopedic treatments.

    PubMed

    Jayabalan, M; Shalumon, K T; Mitha, M K

    2009-06-01

    Biodegradable and injectable hydroxy terminated-poly propylene fumarate (HT-PPF) bone cement was developed. The injectable formulation consisting HT-PPF and comonomer, n-vinyl pyrrolidone, calcium phosphate filler, free radical catalyst, accelerator and radiopaque agent sets rapidly to hard mass with low exothermic temperature. The candidate bone cement attains mechanical strength more than the required compressive strength of 5 MPa and compressive modulus 50 MPa. The candidate bone cement resin elicits cell adhesion and cytoplasmic spreading of osteoblast cells. The cured bone cement does not induce intracutaneous irritation and skin sensitization. The candidate bone cement is tissue compatible without eliciting any adverse tissue reactions. The candidate bone cement is osteoconductive and inductive and allow osteointegration and bone remodeling. HT-PPF bone cement is candidate bone cement for minimally invasive radiological procedures for the treatment of bone diseases and spinal compression fractures.

  3. Facile Preparation of Doxorubicin-Loaded and Folic Acid-Conjugated Carbon Nanotubes@Poly(N-vinyl pyrrole) for Targeted Synergistic Chemo-Photothermal Cancer Treatment.

    PubMed

    Wang, Daquan; Ren, Yibo; Shao, Yongping; Yu, Demei; Meng, Lingjie

    2017-11-15

    We developed a bifunctional nanoplatform for targeted synergistic chemo-photothermal cancer treatment. The nanoplatform was constructed through a facile method in which poly(N-vinyl pyrrole) (PVPy) was coated on cut multiwalled carbon nanotubes (c-MWNTs); FA-PEG-SH was then linked by thiol-ene click reaction to improve the active targeting ability, water dispersibility, and biocompatibility and to extend the circulation time in blood. The PVPy shell not only enhanced the photothermal effect of c-MWNTs significantly but also provided a surface that could tailor targeting molecules and drugs. The resulting MWNT@PVPy-S-PEG-FA possessed high drug-loading ratio as well as pH-sensitive unloading capacity for a broad-spectrum anticancer agent, doxorubicin. Owing to its outstanding efficiency in photothermal conversion and ability in targeted drug delivery, the material could potentially be used as an efficient chemo-photothermal therapeutic nanoagent to treat cancer.

  4. 75 FR 5578 - Submission for OMB Review; Comment Request-Flammability Standards for Clothing Textiles and Vinyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... Standards for Clothing Textiles and Vinyl Plastic Film AGENCY: Consumer Product Safety Commission. ACTION... Commission's flammability standards for clothing textiles and vinyl plastic film. DATES: Written comments on... collection requirements should be captioned ``Clothing Textiles and Film, Collection of Information'' and...

  5. Fabrication of thermo-responsive cotton fabrics using poly(vinyl caprolactam-co-hydroxyethyl acrylamide) copolymer.

    PubMed

    Xiao, Min; González, Edurne; Monterroza, Alexis Martell; Frey, Margaret

    2017-10-15

    A thermo-responsive polymer with hydrophilic to hydrophobic transition behavior, poly(vinyl caprolactam-co-hydroxyethyl acrylamide) P(VCL-co-HEAA), was prepared by copolymerization of vinyl caprolactam and N-hydroxyethyl acrylamide via free radical solution polymerization. The resulting copolymer was characterized by Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The lower critical solution temperature (LCST) of P(VCL-co-HEAA) was determined at 34.5°C. This thermo-responsive polymer was then grafted onto cotton fabrics using 1,2,3,4-butanetetracarboxylic acid (BTCA) as crosslinker and sodium hypophosphite (SHP) as catalyst. FTIR and energy dispersive X-ray spectroscopy (EDS) studies confirmed the successful grafting reaction. The modified cotton fabric exhibited thermo-responsive behavior as evidenced by water vapor permeability measurement confirming decreased permeability at elevated temperature. This is the first demonstration that a PVCL based copolymer is grafted to cotton fabrics. This study provides a new thermo-responsive polymer for fabrication of smart cotton fabrics with thermally switchable hydrophilicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Elastic electron scattering by ethyl vinyl ether

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

    Khakoo, M. A.; Hong, L.; Kim, B.

    2010-02-15

    We report measured and calculated results for elastic scattering of low-energy electrons by ethyl vinyl ether (ethoxyethene), a prototype system for studying indirect dissociative attachment processes that may play a role in DNA damage. The integral cross section displays the expected {pi}{sup *} shape resonance. The agreement between the calculated and measured cross sections is generally good.

  7. Poly(vinyl Chloride) Photostabilization in the Presence of Schiff Bases Containing a Thiadiazole Moiety.

    PubMed

    Shaalan, Naser; Laftah, Nawres; El-Hiti, Gamal A; Alotaibi, Mohammad Hayal; Muslih, Raad; Ahmed, Dina S; Yousif, Emad

    2018-04-15

    Five Schiff bases containing a thiadiazole moiety have been used as poly(vinyl chloride) photostabilizers at low concentrations. The efficiency of Schiff bases as photostabilizers was investigated using various techniques, for example, the changes in poly(vinyl chloride) infrared spectra, molecular weight, chain scission quantum yield, and surface morphology were monitored upon irradiation with an ultraviolet light. Evidently, all the additives used inhibited poly(vinyl chloride) photodegradation at a significant level. The most efficient Schiff base exhibited a high level of aromaticity and contained a hydroxyl group. It seems possible that such photostabilization could be due to the direct absorption of ultraviolet radiation by the additives. In addition, Schiff bases could act as radical scavengers and proton transfer facilitators to stabilize the polymeric materials.

  8. Chemo-enzymatic synthesis of vinyl and l-ascorbyl phenolates and their inhibitory effects on advanced glycation end products.

    PubMed

    Hwang, Seung Hwan; Wang, Zhiqiang; Lim, Soon Sung

    2017-01-01

    This study successfully established the feasibility of a two-step chemo-enzymatic synthesis of l-ascorbyl phenolates. Intermediate vinyl phenolates were first chemically produced and then underwent trans-esterification with l-ascorbic acid in the presence of Novozyme 435® (Candida Antarctica lipase B) as a catalyst. Twenty vinyl phenolates and 11 ascorbyl phenolates were subjected to in vitro bioassays to investigate their inhibitory activity against advanced glycation end products (AGEs). Among them, vinyl 4-hydroxycinnamate (17VP), vinyl 4-hydroxy-3-methoxycinnamate (18VP), vinyl 4-hydroxy-3,5-dimethoxycinnamate (20VP), ascorbyl 4-hydroxy-3-methoxycinnamate (18AP) and ascorbyl 3,4-dimethoxycinnamate (19AP) showed 2-10 times stronger inhibitory activities than positive control (aminoguanidine and its precursors). These results indicated that chemo-enzymatically synthesized compounds have AGE inhibitory effect and thus are effective in either preventing or retarding glycation protein formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The development and characterization of degradable poly(vinyl ester) and poly(vinyl ester)/PEO block copolymers

    NASA Astrophysics Data System (ADS)

    Lipscomb, Corinne Elizabeth

    The development of biodegradable materials is a challenging and important problem in polymer science. A review of the state of the art in degradable materials is presented, which reveals that current biodegradable materials do not exhibit the thermal or mechanical properties necessary for widespread applications. One strategy for toughening polymeric materials, which has previously been applied to non-degradable thermoplastics and thermoplastic elastomers, is the formation of block copolymers. Poly(vinyl esters) (PVE) homopolymers are known to have a wide range of properties, but PVE block copolymers comprise a class of inexpensive and (bio)degradable materials that were previously unknown. Therefore, the synthesis and properties of these block copolymers were explored in an effort to develop robust degradable materials. This thesis research probes the reaction conditions necessary for the reversible-addition fragmentation chain transfer (RAFT) polymerization and chain extension reactions of vinyl ester monomers. PVE di- and triblock copolymers are synthesized and studied, and the triblock copolymers display extremely poor toughness due to their relatively low molecular weights in light of the high entanglement molecular weight of the poly(vinyl acetate) center block. Attempts to improve the mechanical properties of these materials focus on the incorporation of poly(ethylene oxide) (PEO) as a low entanglement molecular weight and biocompatible center block in PVE-containing triblock copolymers. Depending on the choice of PVE endblocks and the overall polymer composition, crystallization of the PEO block can be controlled, confined, or inhibited. Polymers in which PEO crystallization is completely inhibited exhibit enhanced mechanical properties and behave as weak thermoplastics. In order to understand the relationship between the inhibition of PEO crystallization and the mechanical properties of PVE/PEO materials, these polymers were studied using dynamic

  10. The chemistry of dimethacrylate-styrene networks, and, Development of flame retardant, halogen-free fiber reinforced vinyl ester composites

    NASA Astrophysics Data System (ADS)

    Rosario, Astrid Christa

    One of the major classes of polymer matrix resins under consideration for structural composite applications in the infrastructure and construction industries is vinyl ester resin. Vinyl ester resin is comprised of low molecular weight poly(hydroxyether) oligomers with methacrylate endgroups diluted with styrene monomer. The methacrylate endgroups cure with styrene via free radical copolymerization to yield thermoset networks. The copolymerization behavior of these networks was monitored by Fourier Transform Infrared Spectroscopy (FTIR) at various cure conditions. Reactions of the carbon-carbon double bonds of the methacrylate (943 cm-1) and styrene (910 cm-1 ) were followed independently. Oligomers possessing number average molecular weights of 700 g/mole were studied with systematically increasing levels of styrene. The Mortimer-Tidwell reactivity ratios indicated that at low conversion more styrene was incorporated into the network at lower cure temperatures. The experimental vinyl ester-styrene network compositions deviated significantly from those predicted by the Meyer-Lowry integrated copolymer equation at higher conversion, implying that the reactivity ratios for these networks may change with conversion. The kinetic data were used to provide additional insight into the physical and mechanical properties of these materials. In addition to establishing the copolymerization kinetics of these materials, the development of halogen free fiber reinforced vinyl ester composites exhibiting good flame properties was of interest. Flame retardant vinyl ester resins are used by many industries for applications requiring good thermal resistance. The current flame-retardant technology is dependent on brominated vinyl esters, which generate high levels of smoke and carbon monoxide. A series of halogen free binder systems has been developed and dispersed in the vinyl ester to improve flame retardance. The binder approach enables the vinyl ester resin to maintain its low

  11. Reactions of NO 3 with the man-made emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone

    NASA Astrophysics Data System (ADS)

    Pfrang, Christian; Tooze, Christopher; Nalty, Andrew; Canosa-Mas, Carlos E.; Wayne, Richard P.

    Rate coefficients for reactions of nitrate radicals (NO 3) with the anthropogenic emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone (pent-1-en-3-one) were determined to be (9.3±1.1)×10 -12, (9.3±3.2)×10 -12, (1.7±1.3)×10 -12 and (9.4±2.7)×10 -17 cm 3 molecule -1 s -1. We performed kinetic experiments at room temperature and atmospheric pressure using a relative-rate technique with GC-FID analysis. Experiments with ethyl vinyl ether required a modification of our established procedure that might introduce additional uncertainties, and the errors suggested reflect these difficulties. Rate coefficients are discussed in terms of electronic and steric influences. Atmospheric lifetimes with respect to important oxidants in the troposphere were calculated. NO 3-initiated oxidation is found to be the strongly dominating degradation route for 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene and ethyl vinyl ether. Atmospheric concentrations of the alkenes and their relative contribution to the total NMHC emissions from trucks can be expected to increase if plans for the introduction of particle filters for diesel engines are implemented on a global scale. Thus more kinetic data are required to better evaluate the impact of these emissions.

  12. Performance Evaluation of Vinyl Replacement Windows.

    DTIC Science & Technology

    1980-07-15

    VINYL REPLACEMENT WINDOWS P. B. SHEPHERD JOHNS - MANVILLE SALES CORPORATION LEU ! RESEARCH & DEVELOPMENT CENTER CLE 0 KEN-CARYL RANCH DENVER, COLORADO...PE F -I.. E RI.. Philip B.heperd/K^678D00 9. PERFORMING ORGANIZATION NAME AND ADDRESS SO. PROGRAM ELEMENT. PROJECT, TASK Johns - Manville Sales Corporatp...Development Center Ken-Caryl Ranch Denver. Colorado 80217 (303) 979-1000 October 23, 1979 Dear Sir: The Johns - Manville R&D Center has been contacted

  13. Caspase vinyl sulfone small molecule inhibitors prevent axonal degeneration in human neurons and reverse cognitive impairment in Caspase-6-overexpressing mice.

    PubMed

    Pakavathkumar, Prateep; Noël, Anastasia; Lecrux, Clotilde; Tubeleviciute-Aydin, Agne; Hamel, Edith; Ahlfors, Jan-Eric; LeBlanc, Andrea C

    2017-02-28

    The activation of the aspartate-specific cysteinyl protease, Caspase-6, is proposed as an early pathogenic event of Alzheimer disease (AD) and Huntington's disease. Caspase-6 inhibitors could be useful against these neurodegenerative diseases but most Caspase-6 inhibitors have been exclusively studied in vitro or show acute liver toxicity in humans. Here, we assessed vinyl sulfone small molecule peptide caspase inhibitors for potential use in vivo. The IC 50 of NWL vinyl sulfone small molecule caspase inhibitors were determined on Caspase-1 to 10, and Caspase-6-transfected human colon carcinoma HCT116 cells. Inhibition of Caspase-6-mediated axonal degeneration was assessed in serum-deprived or amyloid precursor protein-transfected primary human CNS neurons. Cellular toxicity was measured by phase contrast microscopy, mitochondrial and lactate dehydrogenase colorimetric activity assays, or flow cytometry. Caspase inhibition was measured by fluorogenic activity assays, fluorescence microscopy, and western blot analyses. The effect of inhibitors on age-dependent cognitive deficits in Caspase-6 transgenic mice was assessed by the novel object recognition task. Liquid chromatography coupled to tandem mass spectrometry assessed the blood-brain barrier permeability of inhibitors in Caspase-6 mice. Vinyl sulfone NWL-117 caspase inhibitor has a higher selectivity against Caspase-6, -4, -8, -9, and -10 whereas NWL-154 has higher selectivity against Caspase-6, -8, and -10. The half-maximal inhibitory concentrations (IC 50 ) of NWL-117 and NWL-154 is 192 nM and 100 nM against Caspase-6 in vitro, and 4.82 μM and 3.63 μM in Caspase-6-transfected HCT116 cells, respectively. NWL inhibitors are not toxic to HCT116 cells or to human primary neurons. NWL-117 and NWL-154 inhibit serum deprivation-induced Caspase-6 activity and prevent amyloid precursor protein-mediated neurite degeneration in human primary CNS neurons. NWL-117 crosses the blood brain barrier and reverses age

  14. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    NASA Technical Reports Server (NTRS)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  15. Stereocontrolled Cyanohydrin Ether Synthesis through Chiral Brønsted Acid-Mediated Vinyl Ether Hydrocyanation

    PubMed Central

    Lu, Chunliang; Su, Xiaoge; Floreancig, Paul E.

    2013-01-01

    Vinyl ethers can be protonated to generate oxocarbenium ions that react with Me3SiCN to form cyanohydrin alkyl ethers. Reactions that form racemic products proceed efficiently upon converting the vinyl ether to an α-chloro ether prior to cyanide addition in a pathway that proceeds through Brønsted acid-mediated chloride ionization. Enantiomerically enriched products can be accessed by directly protonating the vinyl ether with a chiral Brønsted acid to form a chiral ion pair. Me3SiCN acts as the nucleophile and PhOH serves as a stoichiometric proton source in a rare example of an asymmetric bimolecular nucleophilic addition reaction into an oxocarbenium ion. Computational studies provide a model for the interaction between the catalyst and the oxocarbenium ion. PMID:23968162

  16. Thermodynamic and Kinetic Behavior of the Polystyrene/Poly(vinyl methyl ether) Blend as Studied by Excimer Fluorescence.

    DTIC Science & Technology

    1986-01-02

    AD-A±63 895 THERMODYNAMIC AND KINETIC BEHAVIOR OF THE / POLYSTYRENE/POLY(YINYL METHYL E..(U) STANFORD UNIY CALIFDEPT OF CHEMICAL ENGINEERING C N...Polystyrene/Poly(vinyl methyl ether) Blend 7. DEcFRMN 81 toOR 30USptE8 00~ as Studied by Excimer Fluorescence 6 EFRIGOG EOTNME *AUTHOR() a. CONTRACT OR GRANT...werea fondoare ihemoriisof * ~ Ex e sp fluodecositionsdu to deud Gen e and hoog Pinus Florsneis shownhase migrationprocSECURITY CLASIFICTIO OFd

  17. Multidimensional chromatographic techniques for hydrophilic copolymers II. Analysis of poly(ethylene glycol)-poly(vinyl acetate) graft copolymers.

    PubMed

    Knecht, Daniela; Rittig, Frank; Lange, Ronald F M; Pasch, Harald

    2006-10-13

    A large variety of hydrophilic copolymers is applied in different fields of chemical industry including bio, pharma and pharmaceutical applications. For example, poly(ethylene glycol)-poly(vinyl alcohol) graft copolymers that are used as tablet coatings are responsible for the controlled release of the active compounds. These copolymers are produced by grafting of vinyl acetate onto polyethylene glycol (PEG) and subsequent hydrolysis of the poly(ethylene glycol)-poly(vinyl acetate) graft copolymers. The poly(ethylene glycol)-poly(vinyl acetate) copolymers are distributed with regard to molar mass and chemical composition. In addition, they frequently contain the homopolymers polyethylene glycol and polyvinyl acetate. The comprehensive analysis of such complex systems requires hyphenated analytical techniques, including two-dimensional liquid chromatography and combined LC and nuclear magnetic resonance spectroscopy. The development and application of these techniques are discussed in the present paper.

  18. Simple and fast polydimethylsiloxane (PDMS) patterning using a cutting plotter and vinyl adhesives to achieve etching results.

    PubMed

    Hyun Kim; Sun-Young Yoo; Ji Sung Kim; Zihuan Wang; Woon Hee Lee; Kyo-In Koo; Jong-Mo Seo; Dong-Il Cho

    2017-07-01

    Inhibition of polydimethylsiloxane (PDMS) polymerization could be observed when spin-coated over vinyl substrates. The degree of polymerization, partially curing or fully curing, depended on the PDMS thickness coated over the vinyl substrate. This characteristic was exploited to achieve simple and fast PDMS patterning method using a vinyl adhesive layer patterned through a cutting plotter. The proposed patterning method showed results resembling PDMS etching. Therefore, patterning PDMS over PDMS, glass, silicon, and gold substrates were tested to compare the results with conventional etching methods. Vinyl stencils with widths ranging from 200μm to 1500μm were used for the procedure. To evaluate the accuracy of the cutting plotter, stencil designed on the AutoCAD software and the actual stencil widths were compared. Furthermore, this method's accuracy was also evaluated by comparing the widths of the actual stencils and etched PDMS results.

  19. Characteristics of women with nausea and vomiting of pregnancy who chose to continue compassionate use of placebo after a randomised trial.

    PubMed

    Matok, I; Umans, J; Feghali, M N; Clark, S; Caritis, S; Miodovnik, M; Hankins, G; Mattison, D R; Nordeng, H; Koren, G

    2013-08-01

    The placebo effect has not been characterised in pregnant women suffering from nausea and vomiting of pregnancy (NVP). Our aim was to characterise determinants of the placebo effect in women treated with placebo for NVP. We analysed data from a multicentre, double blind randomised controlled trial of Diclectin (delayed release doxylamine and pyridoxine) vs placebo for the treatment of NVP. A total of 127 women in the placebo arm and 130 in the active arm provided evaluable data for this analysis. Women who chose to continue placebo on a compassionate basis (n = 41) had significantly better improvement in symptoms of NVP and higher Wellbeing scores than those who did not ask to continue compassionate use. Results were similar in the active drug arm. The request to continue compassionate use of either placebo or active drug could be predicted by greater improvement in symptoms of NVP during the trial period.

  20. 21 CFR 177.1950 - Vinyl chloride-ethylene copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... deciliter per gram as determined by ASTM method D1243-79, “Standard Test Method for Dilute Solution... vinyl chloride-ethylene copol-ymer per 100 grams of sample tested as determined from the organic... using duplicate blanks. Approximately 400 grams of sample (accurately weighed) shall be placed in a 2...

  1. 21 CFR 177.1950 - Vinyl chloride-ethylene copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... deciliter per gram as determined by ASTM method D1243-79, “Standard Test Method for Dilute Solution... vinyl chloride-ethylene copol-ymer per 100 grams of sample tested as determined from the organic... using duplicate blanks. Approximately 400 grams of sample (accurately weighed) shall be placed in a 2...

  2. 40 CFR 721.10483 - Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated, reaction products with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Siloxanes and Silicones, di-Me, Me... Substances § 721.10483 Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated, reaction products with...) The chemical substance identified as Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated...

  3. 40 CFR 721.10483 - Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated, reaction products with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Siloxanes and Silicones, di-Me, Me... Substances § 721.10483 Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated, reaction products with...) The chemical substance identified as Siloxanes and Silicones, di-Me, Me vinyl, hydroxy-terminated...

  4. [Quantitative evaluation of health risk associated with occupational inhalation exposure to vinyl chloride at production plants in Poland].

    PubMed

    Szymczak, W

    1997-01-01

    Vinyl chloride is classified by the IARC in group 1-human carcinogens. In Poland occupational exposure to vinyl chloride is found among workers employed in many branches of industry, among others in the industry of vinyl chloride synthesis and polymerization as well as in the plastics, footwear, rubber, pharmaceutical and metallurgical industries. Concentrations observed range from the noon-determinable level to 90 mg/m3, at the MAC value equal to 5 mg/m3. Neoplasm of liver is a major carcinogenic effect of vinyl chloride. Hence, the health assessment focused on this critical risk. Four different linear dose-response models, developed by several authors and based on results of different epidemiological studies, were used to characterise the extent of cancer risk depending on the level of vinyl chloride concentrations. The estimated risk related to a forty-year employment under exposure equal to MAC values (5 mg/m3) fell within the range from 2.9.10(-4) to 2.6.10(-3). As the figures depict it did not exceed the acceptable level (10(-3)).

  5. Nitroethylation of Vinyl Triflates and Bromides

    PubMed Central

    Padilla–Salinas, Rosaura; Walvoord, Ryan R.; Tcyrulnikov, Sergei

    2013-01-01

    A two-carbon homologation of vinyl triflates and bromides for the synthesis of homoallylic nitro products is described. This palladium-catalyzed double coupling of nitromethane exploits the anion stabilizing and leaving group properties of nitromethane, generating the homo allyl nitro products via a tandem cross-coupling/π-allylation sequence. The resultant process provides a mild and convenient entry of nitroethylated products, which are versatile precursors to β,γ-unsaturated carbonyls, homoallylic amines, and nitrile oxides. PMID:23885976

  6. The Microwave Spectrum of Argon-Vinyl Chloride

    NASA Astrophysics Data System (ADS)

    Leung, Helen O.; Marshall, Mark D.

    2011-06-01

    Through the systematic comparison of the structures of a series of complexes formed between protic acid and fluorine substituted ethylenes, we have been able to observe how tuning the properties of the functional groups (F and H atoms) in ethylene using additional F atoms causes these groups to compete or cooperate with each other in intermolecular interactions. A necessary step for expanding our work in the next natural direction by examining the effects of the less electronegative, but more polarizable Cl atom is the determination of the structures of protic acid-vinyl chloride complexes. Since the rich microwave spectrum of Ar-vinyl chloride has not previously been reported, it is essential to first characterize this rare gas complex. We have observed strong b-type and weak a-type transitions for both 35Cl and 37Cl versions of this species, all of which appear to be doubled. Although ab initio calculations suggest a sufficiently large value of μ_c, c-type lines remain elusive. Indeed, these same calculations reveal the presence of several minima on the interaction potential energy surface, which may provide an explanation.

  7. Maleate/vinyl ether UV-cured coatings: Effects of composition on curing and properties

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

    Noren, G.K.

    1996-10-01

    The effect of the composition of the maleate polyester and the vinyl ether terminated compound on their UV-curing and properties has been investigated. Linear unsaturated polyester resins based on maleic anhydride and 1,5-pentane diol were synthesized. The molecular weight of the unsaturated polyesters was varied by changing the ratio of maleic anhydride to 1,5-pentane diol and the double bond equivalent weight was varied by replacing maleic anhydride with succinic anhydride. Coating formulations containing these unsaturated polyesters, triethylene glycol divinyl ether and a free radical photoinitiator were crosslinked in the presence of UV light. The coatings were very brittle, exhibiting tensilemore » strengths in the range of 1.5-4.0 MPa and elongations of only 3-7%. Diethyl maleate and isobutyl vinyl ether were effective diluents for reducing viscosity but reduced the cure speed. A vinyl ether urethane oligomer was synthesized and enhanced the flexibility and toughness of the coatings when substituted for triethylene glycol divinyl ether.« less

  8. Preparation of poly(vinyl alcohol)/kaolinite nanocomposites via in situ polymerization

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

    Jia Xin; Department of Chemistry, Hexi University, Zhangye 734000; Li Yanfeng

    2008-03-04

    Poly(vinyl alcohol)/kaolinite intercalated nanocomposites (Kao-PVA) were prepared via in situ intercalation radical polymerization. Vinyl acetate (VAc) was intercalated into kaolinite by a displacement method using dimethyl sulfoxide/kaolinite (Kao-DMSO) as the intermediate. Then, PVAc/kaolinite (Kao-PVAc) was obtained via radical polymerization with benzoyl peroxide (BPO) as initiator. Last, PVAc/kaolinite was saponified via direct-hydrolysis with NaOH solution in order to obtain PVA/kaolinite nanocomposites, which was characterized by Fourier-Transformation spectroscopy (FTIR), wide X-ray diffraction (WXRD) and transmission electron microscopy (TEM). Their differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results of the obtained PVA/kaolinite suggested that the thermal properties had an obvious improvement.

  9. Colloidal titration of aqueous zirconium solutions with poly(vinyl sulfate) by potentiometric endpoint detection using a toluidine blue selective electrode.

    PubMed

    Sakurada, Osamu; Kato, Yasutake; Kito, Noriyoshi; Kameyama, Keiichi; Hattori, Toshiaki; Hashiba, Minoru

    2004-02-01

    Zirconium oxy-salts were hydrolyzed to form positively charged polymer or cluster species in acidic solutions. The zirconium hydrolyzed polymer was found to react with a negatively charged polyelectrolyte, such as poly(vinyl sulfate), and to form a stoichiometric polyion complex. Thus, colloidal titration with poly(vinyl sulfate) was applied to measure the zirconium concentration in an acidic solution by using a Toluidine Blue selective plasticized poly(vinyl chloride) membrane electrode as a potentiometric end-point detecting device. The determination could be performed with 1% of the relative standard deviation. The colloidal titration stoichiometry at pH < or = 2 was one mol of zirconium per equivalent mol of poly(vinyl sulfate).

  10. Attitudes, management and consequences of nausea and vomiting of pregnancy in the United States and Canada.

    PubMed

    Mazzotta, P; Maltepe, C; Navioz, Y; Magee, L A; Koren, G

    2000-09-01

    Nausea and vomiting of pregnancy (NVP) affects a large proportion of pregnant women. In 1983, Bendectin((R)), the only FDA-approved drug for NVP, was removed from the market by its manufacturer due to legal costs based on claims of teratogenicity, which were subsequently proven to be unsubstantiated. In Canada, a generic form of Bendectin (Diclectin; a doxylamine/pyridoxine combination) has continued to be available, with increasing use over the last few years. To characterize the attitudes, management and consequences of NVP among pregnant women in the USA, where no approved drug for NVP is available, and in Canada, where such a drug is available. Prospective, observational study. Women suffering from NVP (N = 1444) were interviewed, of which 42% were American and 58% were Canadian. The two groups had similar maternal characteristics and a similar distribution of severity of NVP, although among Canadian women the NVP continued for slightly longer. American respondents were treated significantly more often by an obstetrician as their primary caregiver, were more commonly advised by their caregiver to change their diet and/or lifestyle and to use non-pharmacological agents to manage their NVP, and more often perceived anti-emetics as posing an increased risk for malformations (all P < 0.001). Canadian respondents reported a family physician as their primary caregiver significantly more often, were more commonly advised to take anti-emetic medications and perceived their NVP as causing a concern to their unborn (all P < 0.001). American women experienced significantly larger weight loss, more hospitalizations and more time lost from paid work. Lack of an approved drug for symptoms of NVP may be associated with unwarranted and preventable adverse health effects. Because this is an observational study, these associations do not necessarily prove causation.

  11. Branched polyesters based on poly[vinyl-3-(dialkylamino)alkylcarbamate-co-vinyl acetate-co-vinyl alcohol]-graft-poly(D,L-lactide-co-glycolide): effects of polymer structure on in vitro degradation behaviour.

    PubMed

    Unger, Florian; Wittmar, Matthias; Morell, Frank; Kissel, Thomas

    2008-05-01

    Branched polyesters of the general structure poly[vinyl-3-(dialkylamino)alkylcarbamate-co-vinyl acetate-co-vinyl alcohol]-graft-poly(D,L-lactide-co-glycolide) have shown potential for nano- and micro-scale drug delivery systems. Here the in vitro degradation behaviour with a special emphasis on elucidating structure-property relationships is reported. Effects of type and degree of amine substitution as well as PLGA side chain length were considered. In a first set of experiment, the weight loss of solvent cast films of defined size from 19 polymers was measured as a function of incubation in phosphate buffer (pH 7.4) at 37 degrees C over a time of 21 days. A second study was initiated focusing on three selected polymers in a similar set up, but with additional observation of pH influences (pH 2 and pH 9) and determination of water uptake (swelling) and molecular weights during degradation. Scanning electron micrographs have been recorded at selected time points to characterize film specimens morphologically after degradation. Our investigations revealed the potential to influence the degradation of this polymer class by the degree of amine substitution, higher degrees leading to faster erosion. The erosion rate could further be influenced by the type of amine functionality, DEAPA-modified polyesters degrading as fast as or slightly faster than DMAPA-modified polyesters and these degrading faster than DEAEA-PVA-g-PLGA. As a third option the degradation rate could be modified by the PLGA side chain length, shorter side chains leading to faster erosion. As compared to linear PLGA, remarkably shorter degradation times could be achieved by grafting short PLGA side chains onto amine-modified PVA backbones. Erosion times from less than 5 days to more than 4 weeks could be realized by selecting the type of amine functionality, the degree of amine substitution and the PLGA side chain length at the time of synthesis. In addition, the pathway of hydrolytic degradation can be

  12. Poly(N-vinylpyrrolidone)-block-poly(vinyl acetate) as a drug delivery vehicle for hydrophobic drugs.

    PubMed

    Bailly, Nathalie; Thomas, Mark; Klumperman, Bert

    2012-12-10

    Poly((N-vinylpyrrolidone)-block-poly(vinyl acetate)) (PVP-b-PVAc) block copolymers of varying molecular weight and hydrophobic block lengths were synthesized via controlled radical polymerization and investigated as carriers for the solubilization of highly hydrophobic riminophenazine compounds. These compounds have recently been shown to exhibit a strong activity against a variety of cancer types. PVP-b-PVAc self-assembles into polymer vesicles in aqueous media, and the dialysis method was used to load the water-insoluble drug (clofazimine) into these polymer vesicles. The polymer vesicles were characterized by 1H NMR spectroscopy to confirm vesicle formation and the incorporation of the anticancer drugs into the polymer vesicles. Dynamic light scattering was used to determine the particle size and particle size distribution of the drug-loaded vesicles as well as the stability of the vesicles under physiological conditions. The size of the polymer vesicles did not increase upon loading with clofazimine, and the particle size of 180-200 nm and the narrow particle size distribution were maintained. The morphology of the vesicles was examined by transmission electron microscopy. The polymer vesicles had a relatively high drug loading capacity of 20 wt %. In vitro cytotoxicity studies of PVP-b-PVAc and drug-loaded PVP-b-PVAc were performed against MDA-MB-231 multidrug-resistant breast epithelial cancer cells and MCF12A nontumorigenic breast epithelial cells. In vitro experiments demonstrated that the PVP-b-PVAc drug carrier showed no cytotoxicity, which confirms the biocompatibility of the PVP-b-PVAc drug carrier. The results indicate that the present PVP-b-PVAc block copolymer could be a potential candidate as a drug carrier for hydrophobic drugs.

  13. Thermal stability, antioxidant, and anti-inflammatory activity of curcumin and its degradation product 4-vinyl guaiacol.

    PubMed

    Esatbeyoglu, Tuba; Ulbrich, Katrin; Rehberg, Clemens; Rohn, Sascha; Rimbach, Gerald

    2015-03-01

    Curcumin is a secondary plant metabolite present in Curcuma longa L. Since curcumin is widely used as a food colorant in thermally processed food it may undergo substantial chemical changes which in turn could affect its biological activity. In the current study, curcumin was roasted at 180 °C up to 70 minutes and its kinetic of degradation was analyzed by means of HPLC-PDA and LC-MS, respectively. Roasting of curcumin resulted in the formation of the degradation products vanillin, ferulic acid, and 4-vinyl guaiacol. In cultured hepatocytes roasted curcumin as well as 4-vinyl guaiacol enhanced the transactivation of the redox-regulated transcription factor Nrf2, known to be centrally involved in cellular stress response and antioxidant defense mechanisms. The antioxidant enzyme paraoxonase 1 was induced by roasted curcumin and 4-vinyl guaiacol. Furthermore, roasted curcumin and 4-vinyl guaiacol decreased interleukin-6 gene expression in lipopolysaccharide stimulated murine macrophages. Current data suggest that curcumin undergoes degradation due to roasting and its degradation product exhibit significant biological activity in cultured cells.

  14. Levels of CEA among vinyl chloride and polyvinyl chloride exposed workers

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

    Anderson, H.A.; Snyder, J.; Lewinson, T.

    1978-09-01

    In 1974, vinyl chloride exposed workers were found to have an increased risk of malignant disease (hemangiosarcoma of the liver). We have examined 1,147 workers exposed to vinyl chloride monomer in three VC/PVC polymerization plants, and 269 workers from a PVC extrusion plant manufacturing PVC textile leather, exposed to much lower concentrations of vinyl chloride. Included among the comprehensive clinical and laboratory studies conducted was the CEA titer. We obtained, respectively, 1,115 and 248 CEA titers. Multiple factors were demonstrated which affected the distribution of CEA titers. Cigarette use had the greatest effect, followed by history of specific past illnessesmore » and alcohol intake history. After removing these possible confounding effects, the distribution of CEA titers among the polymerization workers was significantly different from the extrusion plant group and from an unexposed comparison group. Of the six job categories analyzed, only production and maintenance workers had CEA titer distributions significantly different from the comparison group and the extrusion workers. The investigation demonstrates that occupational exposures in VC/PVC polymerization plants can cause elevations in the CEA titers of otherwise healthy individuals. Prospective follow-up is necessary before conclusions can be drawn concerning the usefulness of the CEA titer as a predictive indicator of possible increased risk.« less

  15. Minimalism in radiation synthesis of biomedical functional nanogels.

    PubMed

    Dispenza, Clelia; Sabatino, Maria Antonietta; Grimaldi, Natascia; Bulone, Donatella; Bondì, Maria Luisa; Casaletto, Maria Pia; Rigogliuso, Salvatrice; Adamo, Giorgia; Ghersi, Giulio

    2012-06-11

    A scalable, single-step, synthetic approach for the manufacture of biocompatible, functionalized micro- and nanogels is presented. In particular, poly(N-vinyl pyrrolidone)-grafted-(aminopropyl)methacrylamide microgels and nanogels were generated through e-beam irradiation of PVP aqueous solutions in the presence of a primary amino-group-carrying monomer. Particles with different hydrodynamic diameters and surface charge densities were obtained at the variance of the irradiation conditions. Chemical structure was investigated by different spectroscopic techniques. Fluorescent variants were generated through fluorescein isothiocyanate attachment to the primary amino groups grafted to PVP, to both quantify the available functional groups for bioconjugation and follow nanogels localization in cell cultures. Finally, a model protein, bovine serum albumin, was conjugated to the nanogels to demonstrate the attachment of biologically relevant molecules for targeting purposes in drug delivery. The described approach provides a novel strategy to fabricate biohybrid nanogels with a very promising potential in nanomedicine.

  16. Vinyl sulfoxides as stereochemical controllers in intermolecular Pauson-Khand reactions: applications to the enantioselective synthesis of natural cyclopentanoids.

    PubMed

    Rodríguez Rivero, Marta; Alonso, Inés; Carretero, Juan C

    2004-10-25

    The use of sulfoxides as chiral auxiliaries in asymmetric intermolecular Pauson-Khand reactions is described. After screening a wide variety of substituents on the sulfur atom in alpha,beta-unsaturated sulfoxides, the readily available o-(N,N-dimethylamino)phenyl vinyl sulfoxide (1 i) has proved to be highly reactive with substituted terminal alkynes under N-oxide-promoted conditions (CH3CN, 0 degrees C). In addition, these Pauson-Khand reactions occurred with complete regioselectivity and very high diastereoselectivity (de=86->96 %, (S,R(S)) diastereomer). Experimental studies suggest that the high reactivity exhibited by the vinyl sulfoxide 1 i relies on the ability of the amine group to act as a soft ligand on the alkyne dicobalt complex prior to the generation of the cobaltacycle intermediate. On the other hand, both theoretical and experimental studies show that the high stereoselectivity of the process is due to the easy thermodynamic epimerization at the C5 center in the resulting 5-sulfinyl-2-cyclopentenone adducts. When it is taken into account that the known asymmetric intermolecular Pauson-Khand reactions are limited to the use of highly reactive bicyclic alkenes, mainly norbornene and norbornadiene, this novel procedure constitutes the first asymmetric version with unstrained acyclic alkenes. As a demonstration of the synthetic interest of this sulfoxide-based methodology in the enantioselective preparation of stereochemically complex cyclopentanoids, we have developed very short and efficient syntheses of the antibiotic (-)-pentenomycin I and the (-)-aminocyclopentitol moiety of a hopane triterpenoid.

  17. Characterisation and in vitro stability of low-dose, lidocaine-loaded poly(vinyl alcohol)-tetrahydroxyborate hydrogels.

    PubMed

    Abdelkader, D H; Osman, M A; El-Gizawy, S A; Faheem, A M; McCarron, P A

    2016-03-16

    Poly(vinyl alcohol) hydrogels cross-linked with the tetrahydroxyborate anion possess textural and rheological properties that can be used as novel drug-loaded vehicles for application to traumatic wounds. However, addition of soluble drug substances causes concentration-dependent phase separation and rheological changes. The aim of this work was to investigate the effect of adding a local anaesthetic, but keeping the concentration low in an attempt to prevent these changes. Cross-linked hydrogels prepared from three grades of poly(vinyl alcohol) were characterised rheologically. Temperature sweep studies showed an elevated complex viscosity upon moving from 25°C to 80°C, which remained high for 48 h following completion of the cycle. Adhesion to model dermal surfaces achieved a maximum of 2.62 N cm(-2) and were greater than that observed to epidermal substrates, with a strong dependence on the rate of detachment used during testing. An optimised formulation (6% w/w PVA (31-50; 99) and 2% w/w THB) containing lidocaine hydrochloride loaded to an upper maximum concentration of 1.5% w/w was assessed for phase separation and drug crystallisation. After six months, crystallisation was present in formulations containing 0.7% and 1.5% lidocaine HCl. Changes in pH in response to increases in lidocaine loading were low. Drug release was shown to operate via a non-Fickian process for all three concentrations, with 60% occurring after approximately 24h. It can be concluded that using a low concentration of lidocaine hydrochloride in hydrogels based on poly(vinyl alcohol) will result in crystallisation. Furthermore, these hydrogels are unlikely to induce rapid anaesthesia due to the low loading and slow release kinetics. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Preparation and Properties of Nano-Hydroxyapatite/Gelatin/Poly(vinyl alcohol) Composite Membrane.

    PubMed

    Liao, Haotian; Shi, Kun; Peng, Jinrong; Qu, Ying; Liao, Jinfeng; Qian, Zhiyong

    2015-06-01

    In this study, the bone-like composite membrane based on blends of gelatin (Gel), nano-hydroxyapatite (n-HA) and poly(vinyl alcohol) (PVA) was fabricated by solvent casting and evaporation methods. The effect of n-HA content and the ratio of Gel/PVA on the properties of the composite was investigated. The Gel/PVA and n-HA/Gel/PVA composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), water contact angle measurement and scanning electron microscopy (SEM). The mechanical properties of the composites were determined by tensile tests. The as prepared composite membranes exhibited hydrophobility, the water contact angle of composite membrane was 126.6 when its mass ratio of n-HA/Gel/PVA was 10/50/40. The tensile strength of composite membranes was greatly increased due to the introduction of n-HA, and the tensile strength was increased to 74.92 MPa when the mass ratio of n-HA/Gel/PVA was 10/50/40. SEM observation indicated that n-HA was dispersed in the membranes and a sea-island structure was formed in the n-HA/Gel/PVA composite membranes, resulting in a significant increase in tensile strength. The as-prepared n-HA/Gel/PVA composite membranes may be applied in the field of bone tissue engineering.

  19. 21 CFR 175.350 - Vinyl acetate/crotonic acid copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl acetate/crotonic acid copolymer. 175.350 Section 175.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF...

  20. Development of a novel anisotropic self-inflating tissue expander: in vivo submucoperiosteal performance in the porcine hard palate.

    PubMed

    Swan, Marc C; Bucknall, David G; Czernuszka, Jan T; Pigott, David W; Goodacre, Timothy E E

    2012-01-01

    The advent of self-inflating hydrogel tissue expanders heralded a significant advance in the reconstructive potential of this technique. Their use, however, is limited by their uncontrolled isotropic (i.e., uniform in all directions) expansion. Anisotropy (i.e., directional dependence) was achieved by annealing a hydrogel copolymer of poly(methyl methacrylate-co-vinyl pyrrolidone) under a compressive load for a specified time period. The expansion ratio is dictated by the percentage of vinyl pyrrolidone content and the degree of compression. The expansion rate is modified by incorporating the polymer within a silicone membrane. The in vivo efficacy of differing prototype devices was investigated in juvenile pigs under United Kingdom Home Office Licence. The devices were implanted within a submucoperiosteal pocket in a total of six porcine palates; all were euthanized by 6 weeks after implantation. A longitudinal volumetric assessment of the expanded tissue was conducted, in addition to postmortem analysis of the bony and mucoperiosteal palatal elements. Uncoated devices caused excessive soft-tissue expansion that resulted in mucoperiosteal ulceration, thus necessitating animal euthanasia. The silicone-coated devices produced controlled soft-tissue expansion over the 6-week study period. There was a statistically significant increase in the volume of expanded soft tissue with no evidence of a significant acute inflammatory response to the implant, although peri-implant capsule formation was observed. Attenuation of the bony palatal shelf was noted. A unique anisotropic hydrogel device capable of controlled expansion has been developed that addresses a number of the shortcomings of the technology hitherto available.

  1. Investigation of the interactions of enteric and hydrophilic polymers to enhance dissolution of griseofulvin following hot melt extrusion processing.

    PubMed

    Bennett, Ryan C; Keen, Justin M; Bi, Yunxia Vivian; Porter, Stuart; Dürig, Thomas; McGinity, James W

    2015-07-01

    This study focuses on the application of hot melt extrusion (HME) to produce solid dispersions containing griseofulvin (GF) and investigates the in-vitro dissolution performance of HME powders and resulting tablet compositions containing HME-processed dispersions. Binary, ternary and quaternary dispersions containing GF, enteric polymer (Eudragit L100-55 or AQOAT-LF) and/or vinyl pyrrolidone-based polymer (Plasdone K-12 povidone or S-630 copovidone) were processed by HME. Two plasticizers, triethyl citrate (TEC) and acetyl tributyl citrate (ATBC), were incorporated to aid in melt processing and to modify release of GF in neutral media following a pH-change in dissolution. Products were characterized for GF recovery, degrees of compositional amorphous character, intermolecular interactions and non-sink dissolution performance. Binary dispersions exhibited lower maximum observed concentration values and magnitudes of supersaturated GF in neutral media dissolution in comparison with the ternary dispersions. The quaternary HME products, 1 : 2 : 1 : 0.6 GF : L100-55 : S-630 : ATBC and GF : AQOAT-LF : K-12 : ATBC, were determined as the most optimal concentration-enhancing compositions due to increased hydrogen bonding of enteric functional groups with carbonyl/acetate groups of vinyl pyrrolidone-based polymers, reduced compositional crystallinity and presence of incorporated hydrophobic plasticizer. HME products containing combinations of concentration-enhancing polymers can supersaturate and sustain GF dissolution to greater magnitudes in neutral media following the pH-transition and be compressed into immediate-release tablets exhibiting similar dissolution profiles. © 2015 Royal Pharmaceutical Society.

  2. Pre-emptive therapy for severe nausea and vomiting of pregnancy and hyperemesis gravidarum.

    PubMed

    Koren, G; Maltepe, Caroline

    2004-08-01

    Nausea and vomiting of pregnancy (NVP) affects 80% of pregnancies. Its severe form, hyperemesis gravidarum (HG), results in dehydration, electrolyte imbalance, the need for hospitalisation and can, rarely, be fatal. This was a prospective, open-labelled, controlled, interventional study to evaluate the effectiveness of pre-emptive treatment of NVP symptoms in women who experienced severe NVP or HG in their previous pregnancy. Twenty-five women who reported severe symptoms of NVP with or without HG in their previous pregnancy were recruited and counselled to commence the use of antiemetics as soon as they became aware of the present pregnancy, and no later than the beginning of symptoms. They were followed-up prospectively through the index pregnancy for symptoms of NVP, and were counselled continuously as to how to modify antiemetic doses based on symptoms. A comparison group consisted of randomly selected women also counselled by us for NVP, who had also had severe NVP in the previous pregnancy, but who did not call before a planned pregnancy and thus could not be offered pre-emptive therapy. The recruited women commenced pre-emptive drug therapy for NVP before conception or up to 7 weeks' gestation, before the appearance of NVP symptoms in all cases. In comparison to the previous pregnancy, only eight of these 18 women experienced a HG again in the index pregnancy (P = 0.01). The majority of study the women had an improvement in severity of NVP symptoms compared to the previous pregnancy. In the comparison group (n = 35), symptoms in the index pregnancy remained severe in 28 cases (80%), decreased to moderate in six (16.6%) and decreased to mild in five cases (13.9%). There were five cases of HG in the previous pregnancy and three in the index pregnancy. The pre-emptive group was improved significantly compared to the control group (P = 0.01). Pre-emptive symptom management appears to be effective in preventing severe NVP in general, and HG in particular. Women

  3. Copper/amino acid catalyzed cross-couplings of aryl and vinyl halides with nucleophiles.

    PubMed

    Ma, Dawei; Cai, Qian

    2008-11-18

    Copper-assisted Ullmann-type coupling reactions are valuable transformations for organic synthesis. Researchers have extensively applied these reactions in both academic and industrial settings. However, two important issues, the high reaction temperatures (normally above 150 degrees C) and the stoichiometric amounts of copper necessary, have greatly limited the reaction scope. To solve these problems, we and other groups have recently explored the use of special ligands to promote these coupling reactions. We first showed that the structure of alpha-amino acids can accelerate Cu-assisted Ullmann reactions, leading to the coupling reactions of aryl halides and alpha-amino acids at 80-90 degrees C. In response to these encouraging results, we also discovered that an l-proline ligand facilitated the following transformations: (1) coupling of aryl halides with primary amines, cyclic secondary amines, and N-containing heterocycles at 40-90 degrees C; (2) coupling of aryl halides with sulfinic acid salts at 80-95 degrees C; (3) azidation of aryl halides and vinyl halides with sodium azide at 40-95 degrees C; (4) coupling of aryl halides with activated methylene compounds at 25-50 degrees C. In addition, we found that N,N-dimethylglycine as a ligand facilitated Cu-catalyzed biaryl ether formation at 90 degrees C. Moreover, Sonogashira reactions worked in the absence of palladium and phosphine ligands, forming enamides from vinyl halides and amides at temperatures ranging from ambient temperature up to 80 degrees C. Furthermore, we discovered that an ortho-amide group can accelerate some Ullmann-type reactions. This functional group in combination with other ligand effects allowed for aryl amination or biaryl ether formation at ambient temperature. The coupling between aryl halides and activated methylene compounds even proceeded at -45 degrees C to enantioselectively form a quaternary carbon center. Taking advantage of these results, we developed several novel approaches

  4. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... plants. 61.63 Section 61.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any...

  5. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... plants. 61.63 Section 61.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any...

  6. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... plants. 61.63 Section 61.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any...

  7. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... plants. 61.63 Section 61.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any...

  8. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... plants. 61.63 Section 61.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any...

  9. Comparison of slime-producing coagulase-negative Staphylococcus colonization rates on vinyl and ceramic tile flooring materials.

    PubMed

    Yazgi, H; Uyanik, M H; Ayyildiz, A

    2009-01-01

    This study investigated the colonization of slime-producing coagulase-negative Staphylococcus (CoNS) in 80 patient wards in Turkey (40 vinyl and 40 ceramic tile floors). A total of 480 samples that included 557 CoNS isolates were obtained. Slime production was investigated with the Christensen method and methicillin-susceptibility was tested by the disk-diffusion method. There was a significant difference in the percentage of slime-producing CoNS isolates on vinyl (12.4%) versus ceramic tile flooring (4.4%). From vinyl flooring, the percentage of slime producing methicillin-resistant CoNS (MRCoNS) (8.9%) was significantly higher than for methicillin-sensitive CoNS (MSCoNS) (3.6%), whereas there was no difference from ceramic tile flooring (2.5% MRCoNS versus 1.8% MSCoNS). The most commonly isolated slime-producing CoNS species was S. epidermidis on both types of flooring. It is concluded that vinyl flooring seems to be a more suitable colonization surface for slime-producing CoNS than ceramic tile floors. Further studies are needed to investigate bacterial strains colonized on flooring materials, which are potential pathogens for nosocomial infections.

  10. Functional Degradable Polymers by Radical Ring-Opening Copolymerization of MDO and Vinyl Bromobutanoate: Synthesis, Degradability and Post-Polymerization Modification.

    PubMed

    Hedir, Guillaume G; Bell, Craig A; O'Reilly, Rachel K; Dove, Andrew P

    2015-07-13

    The synthesis of vinyl bromobutanoate (VBr), a new vinyl acetate monomer derivative obtained by the palladium-catalyzed vinyl exchange reaction between vinyl acetate (VAc) and 4-bromobutyric acid is reported. The homopolymerization of this new monomer using the RAFT/MADIX polymerization technique leads to the formation of novel well-defined and controlled polymers containing pendent bromine functional groups able to be modified via postpolymerization modification. Furthermore, the copolymerization of vinyl bromobutanoate with 2-methylene-1,3-dioxepane (MDO) was also performed to deliver a range of novel functional degradable copolymers, poly(MDO-co-VBr). The copolymer composition was shown to be able to be tuned to vary the amount of ester repeat units in the polymer backbone, and hence determine the degradability, while maintaining a control of the final copolymers' molar masses. The addition of functionalities via simple postpolymerization modifications such as azidation and the 1,3-dipolar cycloaddition of a PEG alkyne to an azide is also reported and proven by (1)H NMR spectroscopy, FTIR spectroscopy, and SEC analyses. These studies enable the formation of a novel class of hydrophilic functional degradable copolymers using versatile radical polymerization methods.

  11. Kinetic Studies that Evaluate the Solvolytic Mechanisms of Allyl and Vinyl Chloroformate Esters

    PubMed Central

    D’Souza, Malcolm J.; Givens, Aaron F.; Lorchak, Peter A.; Greenwood, Abigail E.; Gottschall, Stacey L.; Carter, Shannon E.; Kevill, Dennis N.

    2013-01-01

    At 25.0 °C the specific rates of solvolysis for allyl and vinyl chloroformates have been determined in a wide mix of pure and aqueous organic mixtures. In all the solvents studied, vinyl chloroformate was found to react significantly faster than allyl chloroformate. Multiple correlation analyses of these rates are completed using the extended (two-term) Grunwald-Winstein equation with incorporation of literature values for solvent nucleophilicity (NT) and solvent ionizing power (YCl). Both substrates were found to solvolyze by similar dual bimolecular carbonyl-addition and unimolecular ionization channels, each heavily dependent upon the solvents nucleophilicity and ionizing ability. PMID:23549265

  12. Vinyl Monomers Double as UV Stabilizers: 179th ACS Meeting Houston.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1980

    1980-01-01

    Synthesis and polymerization of vinyl monomers that double as stabilizers against degradation of plastics by ultraviolet light has been accomplished. Potential applications include protection of photovoltaic cells in solar power plants. (Author/RE)

  13. Effect of Aromatherapy with Peppermint Oil on the Severity of Nausea and Vomiting in Pregnancy: A Single-blind, Randomized, Placebo-controlled trial.

    PubMed

    Joulaeerad, Narges; Ozgoli, Giti; Hajimehdipoor, Homa; Ghasemi, Erfan; Salehimoghaddam, Fatemeh

    2018-01-01

    Nausea and vomiting are common complaints in the first half of pregnancy. These symptoms can significantly affect a person's personal and professional life. Aromatherapy is one of the types of complementary medicine that is used in the treatment of nausea and vomiting. The objective of this study was to determine the effect of aromatherapy with peppermint oil on the severity of nausea and vomiting of pregnancy (NVP). This was a single-blind clinical trial that was conducted on 56 pregnant women with mild to moderate severity of NVP and 6 to 20 weeks of gestational age. After the determination of gestational age and base severity of NVP in each woman, they were randomly assigned to one of the two groups: peppermint oil (n=28) or placebo (n=28). Inhalation aromatherapy was done for four days and at the end of each day, they responded to the Pregnancy Unique Quantification of Emesis/Nausea questionnaire (PUQE). The data obtained were analyzed with Mann-Whitney test and ANOVA with repeated measures using SPSS software version 22. Also, the level of significance was p<0.05. Although the severity of NVP in each intervention group significantly decreased (p<0.001), the comparison of the severity of NVP during the study period and at the end of it was not statistically significant between the placebo and intervention groups. According to the possibility of neurological mechanisms causing NVP, the effect of aromatherapy with peppermint oil and placebo were the same in this study. This similarity can be due to psychological impacts of intervention on pregnant women.

  14. The effect of heartburn and acid reflux on the severity of nausea and vomiting of pregnancy

    PubMed Central

    Gill, Simerpal Kaur; Maltepe, Caroline; Koren, Gideon

    2009-01-01

    BACKGROUND: Heartburn (HB) and acid reflux (RF) in the non-pregnant population can cause nausea and vomiting; therefore, it is plausible that in women with nausea and vomiting of pregnancy (NVP), HB/RF may increase the severity of symptoms. OBJECTIVE: To determine whether HB/RF during pregnancy contribute to increased severity of NVP. METHODS: A prospectively collected cohort of women who were experiencing NVP and HB, RF or both (n=194) was studied. The Pregnancy-Unique Quantification of Emesis and Nausea (PUQE) scale and its Well-being scale was used to compare the severity of the study cohort’s symptoms. This cohort was compared with a group of women experiencing NVP but no HB/RF (n=188). Multiple linear regression was used to control for the effects of confounding factors. RESULTS: Women with HB/RF reported higher PUQE scores (9.6±2.6) compared with controls (8.9±2.6) (P=0.02). Similarly, Well-being scores for women experiencing HB/RF were lower (4.3±2.1) compared with controls (4.9±2.0) (P=0.01). Multiple linear regression analysis demonstrated that increased PUQE scores (P=0.003) and decreased Well-being scores (P=0.005) were due to the presence of HB/RF as opposed to confounding factors such as pre-existing gastrointestinal conditions/symptoms, hyperemesis gravidarum in previous pregnancies and comorbidities. CONCLUSION: The present cohort study is the first to demonstrate that HB/RF are associated with increased severity of NVP. Managing HB/RF may improve the severity of NVP. PMID:19373420

  15. Response surface method (RSM) for optimization of ionic conductivity of membranes polymer electrolyte poly (vinylidene fluoride) (PVDF) with polyvinyl pyrrolidone (PVP) as pore forming agent

    NASA Astrophysics Data System (ADS)

    Dyartanti, E. R.; Susanto, H.; Widiasa, I. N.; Purwanto, A.

    2017-06-01

    The Membranes Polymer Gel Electrolyte (MPGEs) based poly (vinylidene fluoride) (PVDF) was prepared by a phase inversion method using polyvinyl pyrrolidone (PVP) as a pore-forming agent and N, N-dimethyl acetamide (DMAc) as a solvent and water as non solvet. The membranes were then soaked in 1 M lithium hexafluorophosphate (LiPF6) in ethylene carbonate (EC) / dimethyl carbonate (DMC) / Diethyl carbonate (DEC) (4:2:4 %vol) solution in order to prepare polymer electrolyte membranes. The MPEGs PVDF/PVP/Nanoclay was applied using central composite design (CCD) experimental design to obtain a quantitative relationship between selected membranes prepared parameters namely (PVDF, PVP as pore forming agent and nanoclay filler concentration) and Ionic conductivity MPEGs. The model was used to find the optimum ionic conductivity from polymer electrolyte membranes. The polymer electrolyte membranes show good ionic conductivity on the order of 6.3 - 8.7 x 10-3 S cm-1 at the ambient temperatures. The ionic conductivity tended to increase with PVP and nanoclay concentration and decrease with PVDF composition. The model predicted the maximum ionic conductivity of 8.47 x 10-3 S cm-1 when the PVDF, PVP and nanoclay concentration were set at 8.01 %, 8.04 % and 10.12%, respectively. The first section in your paper.

  16. RAFT Aqueous Dispersion Polymerization of N-(2-(Methacryloyloxy)ethyl)pyrrolidone: A Convenient Low Viscosity Route to High Molecular Weight Water-Soluble Copolymers

    PubMed Central

    2016-01-01

    RAFT solution polymerization of N-(2-(methacryoyloxy)ethyl)pyrrolidone (NMEP) in ethanol at 70 °C was conducted to produce a series of PNMEP homopolymers with mean degrees of polymerization (DP) varying from 31 to 467. Turbidimetry was used to assess their inverse temperature solubility behavior in dilute aqueous solution, with an LCST of approximately 55 °C being observed in the high molecular weight limit. Then a poly(glycerol monomethacylate) (PGMA) macro-CTA with a mean DP of 63 was chain-extended with NMEP using a RAFT aqueous dispersion polymerization formulation at 70 °C. The target PNMEP DP was systematically varied from 100 up to 6000 to generate a series of PGMA63–PNMEPx diblock copolymers. High conversions (≥92%) could be achieved when targeting up to x = 5000. GPC analysis confirmed high blocking efficiencies and a linear evolution in Mn with increasing PNMEP DP. A gradual increase in Mw/Mn was also observed when targeting higher DPs. However, this problem could be minimized (Mw/Mn < 1.50) by utilizing a higher purity grade of NMEP (98% vs 96%). This suggests that the broader molecular weight distributions observed at higher DPs are simply the result of a dimethacrylate impurity causing light branching, rather than an intrinsic side reaction such as chain transfer to polymer. Kinetic studies confirmed that the RAFT aqueous dispersion polymerization of NMEP was approximately four times faster than the RAFT solution polymerization of NMEP in ethanol when targeting the same DP in each case. This is perhaps surprising because both 1H NMR and SAXS studies indicate that the core-forming PNMEP chains remain relatively solvated at 70 °C in the latter formulation. Moreover, dissolution of the initial PGMA63–PNMEPx particles occurs on cooling from 70 to 20 °C as the PNMEP block passes through its LCST. Hence this RAFT aqueous dispersion polymerization formulation offers an efficient route to a high molecular weight water-soluble polymer in a rather

  17. Polyvinylpyrrolidone/Multiwall Carbon Nanotube Composite Based 36° YX LiTaO3 Surface Acoustic Wave For Hydrogen Gas Sensing Applications

    NASA Astrophysics Data System (ADS)

    Chee, Pei Song; Arsat, Rashidah; He, Xiuli; Kalantar-zadeh, Kourosh; Arsat, Mahyuddin; Wlodarski, Wojtek

    2011-05-01

    Poly-vinyl-pyrrolidone (PVP) /Multiwall Carbon Nanotubes (MWNTs) based Surface Acoustic Wave (SAW) sensors are fabricated and characterized, and their performances towards hydrogen gas are investigated. The PVP/MWNTs fibers composite are prepared by electrospinning of the composite aqueous solution deposited directly onto the active area of SAW transducers. Via scanning electron microscopy (SEM), the morphology of the deposited nanostructure material is observed. From the dynamic response, frequency shifts of 530 Hz (1% H2) and 11.322 kHz (0.25% H2) are recorded for the sensors contain of 1.525 g and 1.025 g PVP concentrations, respectively.

  18. Composite poly(vinyl alcohol)/poly(vinyl acetate) electrospun nanofibrous mats as a novel wound dressing matrix for controlled release of drugs

    PubMed Central

    Jannesari, Marziyeh; Varshosaz, Jaleh; Morshed, Mohammad; Zamani, Maedeh

    2011-01-01

    The aim of this study was to develop novel biomedicated nanofiber electrospun mats for controlled drug release, especially drug release directly to an injury site to accelerate wound healing. Nanofibers of poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), and a 50:50 composite blend, loaded with ciprofloxacin HCl (CipHCl), were successfully prepared by an electrospinning technique for the first time. The morphology and average diameter of the electrospun nanofibers were investigated by scanning electron microscopy. X-ray diffraction studies indicated an amorphous distribution of the drug inside the nanofiber blend. Introducing the drug into polymeric solutions significantly decreased solution viscosities as well as nanofiber diameter. In vitro drug release evaluations showed that both the kind of polymer and the amount of drug loaded greatly affected the degree of swelling, weight loss, and initial burst and rate of drug release. Blending PVA and PVAc exhibited a useful and convenient method for electrospinning in order to control the rate and period of drug release in wound healing applications. Also, the thickness of the blend nanofiber mats strongly influenced the initial release and rate of drug release. PMID:21720511

  19. Structure and electrochemical behaviour of 4,7-diazaheptyl-trimethoxy-silane and vinyl-trialkoxy-silane adsorbed at silver surface

    NASA Astrophysics Data System (ADS)

    Łuczak, Teresa; Pankiewicz, Radosław; Łęska, Bogusława; Schroeder, Grzegorz; Bełtowska-Brzezinska, Maria; Brzezinski, Bogumil

    2006-12-01

    Novel self-assembled monolayers were obtained on silver using 4,7-diazaheptyl-trimethoxy-silane (SiN) and vinyl-trialkoxy-silane (SiVA, where the alkyl group is 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60-eicozaoxa- hexaheptaconan). It was shown that thus modified metal surface was protected against electrooxidation. A densely packed monolayer remained stable and did not desorb from the Ag electrode on the potential cycling. The structure of SiN and SiVA as well as their complexes with Li + cations were calculated and visualised by the AM1d and PM5 semi-empirical methods.

  20. Controlled Growth of CdS Quantum Dot in an Amphiphilic Diblock Copolymer Poly(2-Vinyl Pyridine)-b-Poly(n-Hexyl Isocyanate) Reversed Micelle Nanoreactor.

    PubMed

    Samal, Monica; Mohapatra, Priya Ranjan; Yun, Kyu Sik

    2015-09-01

    A diblock copolymer poly(2-vinyl pyridine)-b-poly(n-hexyl isocyanate) (P2VP-b-PHIC) is used for the present study. It has two blocks; a rod-shaped PHIC block that adopts a helical conformation, and a coil shaped P2VP block. In a polar solvent such as THF both PHIC and P2VP blocks are soluble. In mixtures of two solvents, such as THF and methanol, while the solubility of P2VP component is augmented that of PHIC is decreased leading to formation of reversed micelles. The pyridine nitrogen in P2VP block is a reactive site. It forms complexes with a suitable metal ion, such as Cd2+. The micelle is employed as a nanoreactor for synthesis of CdS quantum dot (QD). In this paper, the micellization behaviour of the copolymer and the use of the micelles for synthesis and controlled growth of CdS nanocrystals are demonstrated.

  1. Electrospun nanofibers of poly(vinyl alcohol)reinforced with cellulose nanofibrils

    USDA-ARS?s Scientific Manuscript database

    In this work, nanofibers of poly(vinyl alcohol) (PVA) reinforced with cellulose nanofibrils (CnF) were produced by electrospinning. The effects of applied voltage, polymer concentration and injection rate, tip-to-collector distance (TCD), rotation speed of the collector, and relative humidity on mor...

  2. Shock tube study of dissociation and relaxation in 1,1-difluoroethane and vinyl fluoride.

    PubMed

    Xu, Hui; Kiefer, John H; Sivaramakrishnan, Raghu; Giri, Binod R; Tranter, Robert S

    2007-08-21

    This paper reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser-schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500-2000 K and 43 < P < 424 torr. The vinyl fluoride product of this process then dissociates affecting the late observations. We thus include a laser schlieren study (1717-2332 K, 75 < P < 482 torr in 10 and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass spectrometry (4% vinyl fluoride in neon, 1500-1980 K, 500 < P < 1300 torr). These time-of-flight experiments confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The dissociation experiments are augmented by laser schlieren measurements of vibrational relaxation (1-20% C(2)H(3)F in Kr, 415-1975 K, 5 < P < 50 torr, and 2 and 5% C(2)H(4)F(2) in Kr, 700-1350 K, 6 < P < 22 torr). These experiments exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. An RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large DeltaE(down) of 1600 cm(-1), similar to that found in a previous examination of 1,1,1-trifluoroethane. Dissociation of vinyl fluoride is complicated by the presence of two parallel HF eliminations, both three-center and four-center. Structure calculations find nearly equal barriers for these, and TST calculations show almost identical k(infinity). An RRKM fit to the observed falloff again requires an unusually large DeltaE(down) and the experiments actually support a slightly reduced barrier. These large energy-transfer parameters now seem routine in these large fluorinated species. It is perhaps a surprising result for which there is as yet no explanation.

  3. Laboratory characterization and astrophysical detection of vibrationally excited states of vinyl cyanide in Orion-KL

    NASA Astrophysics Data System (ADS)

    López, A.; Tercero, B.; Kisiel, Z.; Daly, A. M.; Bermúdez, C.; Calcutt, H.; Marcelino, N.; Viti, S.; Drouin, B. J.; Medvedev, I. R.; Neese, C. F.; Pszczółkowski, L.; Alonso, J. L.; Cernicharo, J.

    2014-12-01

    = 1 ⇔ (ν11 = 1,ν15 = 1) dyad (at 806.4/809.9 K), and ν11 = 3 (at 987.9 K), are populated under warm and dense conditions, so they probe the hottest parts of the Orion-KL source. The vibrational temperatures derived for the ν11 = 1, ν11 = 2, and ν15 = 1 states are 252 ± 76 K, 242 ± 121 K, and 227 ± 68 K, respectively; all of them are close to the mean kinetic temperature of the hot core component (210 K). The total column density of CH2CHCN in the ground state is (3.0 ± 0.9) × 1015 cm-2. We report the detection of methyl isocyanide (CH3NC) for the first time in Orion-KL and a tentative detection of vinyl isocyanide (CH2CHNC). We also give column density ratios between the cyanide and isocyanide isomers, obtaining a N(CH3NC)/N(CH3CN) ratio of 0.002. Conclusions: Laboratory characterization of many previously unassigned vibrationally excited states of vinyl cyanide ranging from microwave to THz frequencies allowed us to detect these molecular species in Orion-KL. Column density, rotational and vibrational temperatures for CH2CHCN in their ground and excited states, and the isotopologues have been constrained by means of a sample of more than 1000 lines in this survey. The full Tables A.6-A.14 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A44This work was based on observations carried out with the IRAM-30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

  4. Development of electrospun poly (vinyl alcohol)-based bionanocomposite scaffolds for bone tissue engineering.

    PubMed

    Enayati, Mohammad Saied; Behzad, Tayebeh; Sajkiewicz, Pawel; Rafienia, Mohammad; Bagheri, Rouhollah; Ghasemi-Mobarakeh, Laleh; Kolbuk, Dorota; Pahlevanneshan, Zari; Bonakdar, Shahin H

    2018-04-01

    The article is focused on the role of nanohydroxy apatite (nHAp) and cellulose nanofibers (CNFs) as fillers in the electrospun poly (vinyl alcohol) (ES-PVA) nanofibers for bone tissue engineering (TE). Fibrous scaffolds of PVA, PVA/nHAp (10 wt.%), and PVA/nHAp(10 wt.%)/CNF(3 wt.%) were successfully fabricated and characterized. Tensile test on electrospun PVA/nHAp10 and PVA/nHAp10/CNF3 revealed a three-fold and seven-fold increase in modulus compared with pure ES-PVA (45.45 ± 4.77). Although, nanofiller loading slightly reduced the porosity percentage, all scaffolds had porosity higher than 70%. In addition, contact angle test proved the great hydrophilicity of scaffolds. The presence of fillers reduced in vitro biodegradation rate in PBS while accelerates biomineralization in simulated body fluid (SBF). Furthermore, cell viability, cell attachment, and functional activity of osteoblast MG-63 cells were studied on scaffolds showing higher cellular activity for scaffolds with nanofillers. Generally, the obtained results confirm that the 3-componemnt fibrous scaffold of PVA/nHAp/CNF has promising potential in hard TE. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1111-1120, 2018. © 2018 Wiley Periodicals, Inc.

  5. The Vinyl Chloride Problem: Several Routes to One Compound.

    ERIC Educational Resources Information Center

    Nechvatal, A.; And Others

    This unit is one of a group of units written to fit the Certificate of Sixth Year Studies (CSYS) chemistry course, but it could be used in most Sixth Form courses. These materials are designed for use in a group decision-making format with each of three groups representing a different manufacturing process which produces vinyl chloride. The unit…

  6. DISPERSION POLYMERIZATION OF 1-VINYL-2-PYRROLIDONE IN SUPERCRITICAL CARBON DIOXIDE. (R826115)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. Safety and efficacy of vinyl bags in prevention of hypothermia of preterm neonates at birth.

    PubMed

    Gathwala, Geeta; Singh, Gurmeet; Agrawal, Nitika

    2010-01-01

    The present study was planned to evaluate the safety and efficacy of vinyl bags in prevention of hypothermia during resuscitation at birth in very low birth weight neonates. Sixty neonates of gestational age ≤32 weeks and birth weight ≤ 1500gm were randomised to either study group, or control group. Study group neonates were put in vinyl bags up to neck and the head was covered with a cap after drying immediately following delivery and resuscitated under radiant warmer. Control group neonates were resuscitated by conventional drying under radiant warmer. Mean axillary and rectal temperature recorded immediately after admission to NICU were significantly higher in the study group compared to control group. Temperature recorded after 1 hour of admission to NICU were however comparable between the two groups. As temperature maintenance in these VLBW neonates is of tremendous importance, it would make sense to recommend the use of vinyl bags during their resuscitation.

  8. Preparation of end-grafted polymer brushes by nitroxide-mediated free radical polymerization of vaporized vinyl monomers.

    PubMed

    Li, Jun; Chen, Xiaoru; Chang, Ying-Chih

    2005-10-11

    In this work, we report a gas-phase polymerization approach to create end-grafted vinyl based polymer films on silicon oxide based substrates. The "surface-initiated vapor deposition polymerization" (SI-VDP) of vaporized vinyl monomers, via the nitroxide-mediated free radical polymerization mechanism, was developed to fabricate various homo- and block copolymer brushes from surface-bound initiators, 1-(4'-oxa-2'-phenyl-12'-trimethoxysilyldodecyloxy)-2,2,6,6-tetra-methylpiperidine ("TEMPO"). The resulting polymer thin films were characterized by the Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ellipsometry, and contact angle goniometry, respectively, to identify the surface composition, film thickness, surface coverage, and water contact angles. Through the SI-VDP, end-grafted polymer films of polystyrene (PSt), poly(acrylic acid) (PAAc), poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA), and poly(N-isopropylacrylamide) (PNIPAAm) with 10-200 nm thicknesses were fabricated. Furthermore, the block copolymer films of PAAc (1st block)-b-PSt (2nd block), PSt (1st block)-b-PAAc (2nd block), and a triblock copolymer film of PAAc (1st)-b-PSt (2nd)-b-PHPMA (3rd), were also fabricated, suggesting the "renewability" of the TEMPO-initiated polymerization in the SI-VDP scheme. It is also noticed that the SI-VDP is more efficient than the conventional solution phase polymerization in producing functional polymer brushes such as PNIPAAm, PAAc, or PAAc-b-PSt end-grafted films. In summary, our studies have shown clear advantages of the SI-VDP setup for the nitroxide-mediated polymerization scheme in controlling synthesis of end-grafted homo- and copolymer thin films.

  9. Nanostructural surface engineering of grafted polymers on inorganic oxide substrates for membrane separations

    NASA Astrophysics Data System (ADS)

    Yoshida, Wayne Hiroshi

    Nanostructural engineering of inorganic substrates by free radical graft polymerization was studied with the goal of developing new membrane materials for pervaporation. Graft polymerization consisted of modification of surface hydroxyls with vinyl trimethoxysilane, followed by solution graft polymerization reaction using either vinyl acetate (VAc) or vinyl pyrrolidone (VP). The topology of the modified surfaces was studied by atomic force microscopy (AFM) on both atomically smooth silicon wafer substrates and microporous inorganic membrane supports in order to deduce the effects of modification on the nanostructural properties of the membrane. While unmodified wafers showed a root-mean-square (RMS) surface roughness of 0.21 +/- 0.03 nm, roughness increased to 3.15 +/- 0.23 nm upon silylation. Under poor solvent conditions (i.e., air), surfaces modified with higher poly(vinyl acetate) (PVAc) or poly(vinyl pyrrolidone) (PVP) polymer graft yields displayed lateral inhomogeneities in the polymer layer. Although RMS surface roughness was nearly identical (0.81--0.85 nm) for PVAc-modified surfaces grafted at different monomer concentrations, the skewness of the height distribution decreased from 2.22 to 0.78 as polymer graft yield increased from 0.8 to 3.5 mg/m2. The polymer-modified surfaces were used to create inorganic pervaporation membranes consisting of a single macromolecular separation layer formed by graft polymerization. PVAc grafted silica membranes (500A native pore size) were found selective for MTBE in the separation of 0.1--1% (v/v) MTBE from water, achieving MTBE enrichment factors as high as 371 at a permeate flux of 0.38 l/m2 hr and a Reynolds number of 6390; however, these membranes could not separate anhydrous organic mixtures. Pervaporative separation of methanol/MTBE mixtures was possible with PVAc and PVP-modified alumina supports of 50A native pore size, where the separation layer consisted of grafted polymer chains with estimated radius of

  10. Sonochemical synthesis of PVA/PVP blend nanocomposite containing modified CuO nanoparticles with vitamin B1 and their antibacterial activity against Staphylococcus aureus and Escherichia coli.

    PubMed

    Mallakpour, Shadpour; Mansourzadeh, Soheila

    2018-05-01

    The aim of this paper was to blend the polymers, poly(N-vinyl-2-pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) to produce a novel composite materials possessing the benefits of both. CuO nanoparticles (NPs) were used as a suitable filler to fabricate the blend nanocomposites (NCs) with desired properties. First, the surface of NPs, was modified with vitamin B 1 (VB 1 ) as a bio-safe coupling agent. Then, the blend NCs with various ratios of modified CuO (3, 5, and 7 wt%) were fabricated under ultrasonic irradiations followed by casting/solvent evaporation method. These processes are fast and green way to disperse the NPs sufficiently. Several techniques were applied for the characterization of the obtained NCs. morphology examination demonstrated the morphology of NCs and compatibility of NPs with the blend polymer. EDX results indicated the weight and atomic percentage of the achieved materials. TGA analysis verified that the NCs show higher thermal properties than the neat blend polymer. Also embedding the modified NPs into the blend polymer had effected on optical absorbance of the obtained NCs. The contact angle measurements confirmed that the hydrophilicity decreased for different proportions of the modified NPs loaded in the blend polymer. Finally, NCs show better bactericidal effects against gram-positive than gram-negative bacteria. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Merging Photoredox with 1,2-Metallate Rearrangements: The Photochemical Alkylation of Vinyl Boronate Complexes.

    PubMed

    Silvi, Mattia; Sandford, Christopher; Aggarwal, Varinder K

    2017-04-26

    Vinyl boronates react with electron-deficient alkyl iodides in the presence of visible light to give boronic esters in which two new C-C bonds have been created. The reaction occurs by radical addition of an electron-deficient alkyl radical to the vinyl boronate followed by electron transfer with another molecule of alkyl iodide, continuing the chain, and triggering a 1,2-metalate rearrangement. In a number of cases, the use of a photoredox catalyst enhances yields significantly. The scope of the radical precursor includes α-iodo ketones, esters, nitriles, primary amides, α-fluorinated halo-acetates and perfluoroalkyl iodides.

  12. Electrocatalytic effect of polyvinyl pyrrolidone capped platinum nanoparticles electrodeposited on platinum electrode for ammonia oxidation

    NASA Astrophysics Data System (ADS)

    Mayedwa, Noluthando; Matinise, Nolubabalo; Mongwaketsi, Nametso; Maaza, Malik

    2018-05-01

    The aim of this work was to study structural and kinetic parameters as well as the mechanism of platinum nanoparticles (PtNP) reduced with sodium borohydride (NaBH4) and capped with polyvinyl pyrrolidone (PVP). The nanoparticles were supported on Pt electrode for ammonia oxidation in fuel cell application. X-ray diffraction (XRD) was used to study structural composition and high resolution transmission electron microscopy (HRTEM) was used for morphological study of the nanoalloy. The electrocatalysts were studied in alkaline solution of potassium hydroxide (KOH) by cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS). CV showed that the ammonia oxidation over potential for PtNP was -431 mV and with exchange current density of 1.726 × 10-4 A. EIS showed that the charge transfer resistance (Rct) of PtNP was the lowest (Rct = 1.943 × 106 Ω) compared to that of bare Pt working electrode (2.0604 × 106 Ω), indicating that the Pt nanoparticles have good conductivity and played an important role in accelerating the transfer of electrons.

  13. Effect of Aromatherapy with Peppermint Oil on the Severity of Nausea and Vomiting in Pregnancy: A Single-blind, Randomized, Placebo-controlled trial

    PubMed Central

    Joulaeerad, Narges; Ozgoli, Giti; Hajimehdipoor, Homa; Ghasemi, Erfan; Salehimoghaddam, Fatemeh

    2018-01-01

    Background: Nausea and vomiting are common complaints in the first half of pregnancy. These symptoms can significantly affect a person's personal and professional life. Aromatherapy is one of the types of complementary medicine that is used in the treatment of nausea and vomiting. The objective of this study was to determine the effect of aromatherapy with peppermint oil on the severity of nausea and vomiting of pregnancy (NVP). Methods: This was a single-blind clinical trial that was conducted on 56 pregnant women with mild to moderate severity of NVP and 6 to 20 weeks of gestational age. After the determination of gestational age and base severity of NVP in each woman, they were randomly assigned to one of the two groups: peppermint oil (n=28) or placebo (n=28). Inhalation aromatherapy was done for four days and at the end of each day, they responded to the Pregnancy Unique Quantification of Emesis/Nausea questionnaire (PUQE). The data obtained were analyzed with Mann-Whitney test and ANOVA with repeated measures using SPSS software version 22. Also, the level of significance was p<0.05. Results: Although the severity of NVP in each intervention group significantly decreased (p<0.001), the comparison of the severity of NVP during the study period and at the end of it was not statistically significant between the placebo and intervention groups. Conclusion: According to the possibility of neurological mechanisms causing NVP, the effect of aromatherapy with peppermint oil and placebo were the same in this study. This similarity can be due to psychological impacts of intervention on pregnant women.

  14. Accessing siloxane functionalized polynorbornenes via vinyl-addition polymerization for CO 2 separation membranes

    DOE PAGES

    Mahurin, Shannon Mark; Sokolov, Alexei P.; Saito, Tomonori; ...

    2016-07-06

    Here, the vinyl addition polymerization of norbornylbased monomers bearing polar functional groups is often problematic, leading to low molecular weight polymers in poor yield. Herein, we provide proof-of-principle evidence that addition-type homopolymers of siloxane substituted norbornyl-based monomers may be readily synthesized using the catalyst trans-[Ni(C 6F 5) 2(SbPh 3) 2]. Polymerizations using this catalyst reached moderate to high conversion in just 5 min of polymerization and produced siloxanesubstituted polymers with molecular weights exceeding 100 kg/mol. These polymers showed excellent thermal stability (T d ≥ 362 °C) and were cast into membranes that displayed high CO 2 permeability and enhanced COmore » 2/N 2 selectivity as compared to related materials.« less

  15. Flexible Vinyl and Urethane Coating and Printing: New Source Performance Standards (NSPS)

    EPA Pesticide Factsheets

    Learn about the New Source Performance Standards (NSPS) for flexible vinyl and urethane coating and printing by reading the rule summary, the rule history, the code of federal regulations subpart and related rules

  16. Lead and Cadmium in Vinyl Children's Products. A Greenpeace Expose.

    ERIC Educational Resources Information Center

    Di Gangi, Joseph

    Polyvinyl chloride (vinyl or PVC) is a substance widely used in children's products. Because children in contact with these products may ingest substantial quantities of potentially harmful chemicals during normal play, especially when they chew on the product, this Greenpeace study examined the levels of lead and cadmium in a variety of consumer…

  17. VIEW OF DINING ROOM ENTRY (VIA CARPORT), SHOWING VINYL SIDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF DINING ROOM ENTRY (VIA CARPORT), SHOWING VINYL SIDING AND PANELING THAT HAS BEEN APPLIED. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

  18. EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ON THE SOUTHEAST SIDE OF THE UNIT - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

  19. Enhanced PL and EL properties of Alq3/nano-TiO2 with the modification of 8-vinyl POSS

    NASA Astrophysics Data System (ADS)

    Li, Jie; Xie, Bing; Xia, Kai; Zhao, Chunmao; Li, Yingchun; Hu, Shengliang

    2018-04-01

    In this study, tris (8-hydroxyquinoline) aluminum/nano-titanium dioxide (Alq3/nano-TiO2) composites were synthesized using a simply in-situ process with 8-vinyl polyhedral oligomeric silsesquioxane (POSS) as a modifier. The as-prepared Alq3/nano-TiO2 composites were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible (UV-vis) absorption spectra. The effect of modification on luminescence properties for the samples was studied by photoluminescence (PL) spectra, electroluminescence (EL) spectra and time-resolved luminescence decay curves. Organic light emitting diodes (OLEDs) with the corresponded emitting layer structure were investigated. The results show that the amphiphilicity of the 8-vinyl POSS leads to well-dispersion state of the nano-TiO2 in the Alq3. Adding a proper weight percentage of 8-vinyl POSS is beneficial for the PL and EL properties enhancement of the composites. OLED using the Alq3/nano-TiO2 with 1 wt% 8-vinyl POSS emitting layer has the low turn-on voltage (4.7 V at 1 cd/m2), high maximum luminance (7463 cd/m2 at 8.75 V), and high luminous efficiency (1.13 cd/A at 100 mA/cm2). Adding 1 wt% 8-vinyl POSS in Alq3/nano-TiO2 can increase the EL intensity by a factor of 37.1 at 8 V. These values are better than those for OLEDs using the Alq3 emitting layer. The increase in luminance and current efficiency stability can be attributed to the energy transfer process between the Alq3 and the nano-TiO2, and the suppression of the self-quenching by caged 8-vinyl POSS molecules.

  20. Ultrasonic-assisted synthesis of phosphorus graphene oxide/poly (vinyl alcohol) polymer and surface resistivity research of phosphorus graphene oxide/poly (vinyl alcohol) film.

    PubMed

    Li, Jihui; Li, Yongshen; Niu, Shuai; Li, Ning

    2017-05-01

    In this paper, phosphorus graphene oxide/poly (vinyl alcohol) polymer (PGO/PVA polymer) was synthesized by PGO and PVA via the esterification in the case of faint acidity and the ultrasound irradiation and characterized; moreover, phosphorus graphene oxide/poly (vinyl alcohol) film (PGO/PVA film) was prepared by PGO/PVA polymer and characterized; also, the surface resistivity of PGO/PVA film was investigated in the case of the different amount of PGO. Based on those, it had been found that PGO reacted with PVA to produce PGO/PVA polymer via the esterification under the ultrasonic-assisted condition, and PGO/PVA polymer was structured by 2D lattice of PGO and the chain of PVA connected in the form of six-member lactone ring and phosphonic ester, and PGO/PVA film was constituted by PGO/PVA polymer, and surface resistivity of 0.00, 0.75, 1.50, 2.25 and 3.00wt% of PGO/PVA film were 6.85×10 8 , 2.98×10 8 , 1.42×10 6 , 7.66×10 4 and 1.29×10 5 Ω/sq, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Thermoplastic rubber comprising ethylene-vinyl acetate copolymer, asphalt and fluxing oil

    NASA Technical Reports Server (NTRS)

    Hendel, F. J. (Inventor)

    1970-01-01

    A thermoplastic rubber is made from a mixture of between about 10 percent and about 50 percent of asphalt, between about 5 percent and about 30 percent fluxing oil, and between about 35 percent and about 70 percent of a copolymer of polyethylene and vinyl acetate.

  2. Enhancing the Oxidation Stability of Polydivinylbenzene Films via Residual Pendant Vinyl Passivation

    DOE PAGES

    Lepro, Xavier; Ehrmann, Paul; Rodriguez, Jennifer; ...

    2018-01-11

    Polydivinylbenzene (PDVB) is a thermally stable, optically transparent, crosslinked polymer that until recently has been difficult to synthesize as a thin film. With the recent demonstration of initiated chemical vapor deposition (iCVD) of thin PDVB films, a renewed interest in the material properties of PDVB has developed. In particular, attention is now focused on its oxidation pathways and long-term stability under the desired application use conditions. In this paper, we report on the thermal and environmental stability of PDVB films and show that unreacted pendant vinyl groups drive polymer oxidation upon exposure to either air or light. We demonstrate thatmore » such vinyls can be effectively passivated by a simple ex-situ thermal annealing at ca. 300 °C in inert atmosphere that induces an 87% reduction of the PDVB oxidation rate in air and slows light (λ=405 nm) induced oxidation by 56%. While the thermal annealing is less effective at preventing oxidation under higher energy (λ = 365 nm) UV light, we demonstrate that this aging pathway is based on the presence of reactive oxygen species rather than traditional photo-oxidation. Finally, vinyl removal through ex-situ thermal annealing improves the chemical stability of iCVD PDVB to continuous air (over 500 days) or light (70 hours) exposure and offers a simple option to improve its environmental aging resistance which is important for long-term protective applications.« less

  3. Biomaterial properties evaluation of poly(vinyl acetate- alt-maleic anhydride)/chitosan nanocapsules

    NASA Astrophysics Data System (ADS)

    Raţă, Delia Mihaela; Popa, Marcel; Chailan, Jean-François; Zamfir, Carmen Lăcrămioara; Peptu, Cătălina Anişoara

    2014-08-01

    Nanocapsules with diameter around 100 nm based on a natural polymer (chitosan) and a synthetic polymer poly(vinyl acetate- alt-maleic anhydride) [poly(MAVA)] by interfacial condensation method were prepared. The present study proposes a new type of biocompatible nanocapsules based on poly(vinyl acetate- alt-maleic anhydride-chitosan) (MCS) able to become a reliable support for inclusion and release of drugs. The spherical shape of the nanocapsules was evidenced by scanning electron microscopy. Nanocapsules presented a good Norfloxacin loading and release capacity. Haemocompatibility tests have demonstrated that the nanocapsules present a low toxicity and a good compatibility with sanguine medium. The biocompatibility properties of the nanocapsules after their intraperitoneal administration in rats were evidenced by histopathological examination of different organs (brain, liver, kidney, and lung). The results are encouraging and the nanocapsules can be used as controlled drug delivery systems.

  4. Investigation of yeast invertase immobilization onto cupric ion-chelated, porous, and biocompatible poly(hydroxyethyl methacrylate-n-vinyl imidazole) microspheres.

    PubMed

    Sari, Müfrettin Murat

    2011-04-01

    Cupric ion-chelated poly(hydroxyethyl methacrylate-n-vinyl imidazole) (poly(HEMA-VIM)) microspheres prepared by suspension polymerization were investigated as a specific adsorbent for immobilization of yeast invertase in a batch system. They were characterized by scanning electron microscopy, surface area, and pore size measurements. They have spherical shape and porous structure. The specific surface area of the p(HEMA-VIM) spheres was found to be 81.2 m²/g with a size range of 70-120 μm in diameter, and the swelling ratio was 86.9%. Then, Cu(II) ion chelated on the microspheres (546 μmol Cu(II)/g), and they were used in the invertase adsorption. Maximum invertase adsorption was 51.2 mg/g at pH 4.5. Cu(II) chelation increases the tendency from Freundlich-type to Langmuir-type adsorption model. The optimum activity for both free and adsorbed invertase was observed at pH 4.5. The optimum temperature for the poly(HEMA-VIM)/Cu(II)-invertase system was found to be at 55 °C, 10 °C higher than that of the free enzyme at 45 °C. V(max) values were determined as 342 and 304 U/mg enzyme, for free and adsorbed invertase, respectively. K(m) values were found to be same for free and adsorbed invertase (20 mM). Thermal and pH stability and reusability of invertase increased with immobilization.

  5. Infralimbic GluN2A-Containing NMDA Receptors Modulate Reconsolidation of Cocaine Self-Administration Memory.

    PubMed

    Hafenbreidel, Madalyn; Rafa Todd, Carolynn; Mueller, Devin

    2017-04-01

    Addiction is characterized by high relapse susceptibility, and relapse can be triggered by drug-associated cues. Cue presentation induces retrieval of the drug-cue memory, which becomes labile and must be reconsolidated into long-term storage. Repeated unpaired cue presentation, however, promotes extinction. Cue-reactivity can be reduced by blocking reconsolidation or facilitating extinction, which are mediated by NMDA receptors (NMDArs). However, the role of NMDArs in either process following self-administration is unclear. Thus, to determine their role in extinction, rats learned to self-administer cocaine before receiving injections of the NMDAr antagonist CPP immediately after four 45-min extinction sessions. During a subsequent 90-min extinction retention test, CPP-treated rats lever pressed less than saline-treated rats indicating that NMDAr blockade facilitated extinction or disrupted drug-cue memory reconsolidation. In addition, infusing CPP into the infralimbic medial prefrontal cortex (IL-mPFC), a structure implicated in extinction, before four 45-min or immediately after four 30min extinction sessions, had similar results during the extinction retention tests. Next, the GluN2A-selective antagonist NVP or GluN2B-selective antagonist Ro25 was infused into IL-mPFC or nucleus accumbens (NAc) shell, another structure implicated in extinction, after four 45-min extinction sessions. Blocking GluN2A-, but not GluN2B-, containing NMDArs, in IL-mPFC or NAc shell reduced lever pressing during the extinction retention tests. Finally, to dissociate reconsolidation from extinction, NVP was infused into IL-mPFC after four 10-min reactivation sessions, which resulted in reduced lever pressing during the retention test. These results indicate that IL-mPFC GluN2A-containing NMDArs modulate reconsolidation, and suggest a novel treatment strategy, as reducing cue reactivity could limit relapse susceptibility.

  6. Infralimbic GluN2A-Containing NMDA Receptors Modulate Reconsolidation of Cocaine Self-Administration Memory

    PubMed Central

    Hafenbreidel, Madalyn; Rafa Todd, Carolynn; Mueller, Devin

    2017-01-01

    Addiction is characterized by high relapse susceptibility, and relapse can be triggered by drug-associated cues. Cue presentation induces retrieval of the drug-cue memory, which becomes labile and must be reconsolidated into long-term storage. Repeated unpaired cue presentation, however, promotes extinction. Cue-reactivity can be reduced by blocking reconsolidation or facilitating extinction, which are mediated by NMDA receptors (NMDArs). However, the role of NMDArs in either process following self-administration is unclear. Thus, to determine their role in extinction, rats learned to self-administer cocaine before receiving injections of the NMDAr antagonist CPP immediately after four 45-min extinction sessions. During a subsequent 90-min extinction retention test, CPP-treated rats lever pressed less than saline-treated rats indicating that NMDAr blockade facilitated extinction or disrupted drug-cue memory reconsolidation. In addition, infusing CPP into the infralimbic medial prefrontal cortex (IL-mPFC), a structure implicated in extinction, before four 45-min or immediately after four 30min extinction sessions, had similar results during the extinction retention tests. Next, the GluN2A-selective antagonist NVP or GluN2B-selective antagonist Ro25 was infused into IL-mPFC or nucleus accumbens (NAc) shell, another structure implicated in extinction, after four 45-min extinction sessions. Blocking GluN2A-, but not GluN2B-, containing NMDArs, in IL-mPFC or NAc shell reduced lever pressing during the extinction retention tests. Finally, to dissociate reconsolidation from extinction, NVP was infused into IL-mPFC after four 10-min reactivation sessions, which resulted in reduced lever pressing during the retention test. These results indicate that IL-mPFC GluN2A-containing NMDArs modulate reconsolidation, and suggest a novel treatment strategy, as reducing cue reactivity could limit relapse susceptibility. PMID:28042872

  7. Stereoselective preparation of quaternary 2-vinyl sphingosines and ceramides and their effect on basal sphingolipid metabolism.

    PubMed

    Calderón, Raquel; Mercadal, Nerea; Abad, José Luis; Ariza, Xavier; Delgado, Antonio; Garcia, Jordi; Rodríguez, Aleix; Fabriàs, Gemma

    2017-06-01

    The dicyclohexylborane-mediated addition of allene 1 to (E)-2-tridecenal affords a quaternary protected 2-amino-2-vinyl-1,3-diol in good yield as a single diastereomer. This compound is readily transformed into the four stereoisomers of the quaternary (E)-2-vinyl analogs of sphingosine. The metabolic fate and the effect of these compounds on the basal sphingolipid metabolism in human A549 lung adenocarcinoma cells has been studied, together with the ceramide analog of the most relevant vinylsphingosine derivative. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Assimilation of NH₄Br in Polyvinyl Alcohol/Poly(N-vinyl pyrrolidone) Polymer Blend-Based Electrolyte and Its Effect on Ionic Conductivity.

    PubMed

    Parameswaran, V; Nallamuthu, N; Devendran, P; Manikandan, A; Nagarajan, E R

    2018-06-01

    Biodegradable polymer blend electrolyte based on ammonium based salt in variation composition consisting of PVA:PVP were prepared by using solution casting technique. The obtained films have been analyzed by various technical methods like as XRD, FT-IR, TG-DSC, SEM analysis and impedance spectroscopy. The XRD and FT-IR analysis exposed the amorphous nature and structural properties of the complex formation between PVA/PVP/NH4Br. Impedance spectroscopy analysis revealed the ionic conductivity and the dielectric properties of PVA/PVP/NH4Br polymer blend electrolyte films. The maximum ionic conductivity was determined to be 6.14 × 10-5 Scm-1 for the composition of 50%PVA: 50%PVP: 10% NH4Br with low activation energy 0.3457 eV at room temperature. Solid state battery is fabricated using highest ionic conducting polymer blend as electrolyte with the configuration Zn/ZnSO4 · 7H2O (anode) ∥ 50%PVA: 50%PVP: 10% NH4Br ∥ Mn2O3 (cathode). The observed open circuit voltage is 1.2 V and its performance has been studied.

  9. The impact of electron beam irradiation on Low density polyethylene and Ethylene vinyl acetate

    NASA Astrophysics Data System (ADS)

    Sabet, Maziyar; Soleimani, Hassan

    2017-05-01

    Improvement of measured gel content, hardness, tensile strength and elongation at break of Ethylene vinyl acetate (EVA) have confirmed positive effect of electron beam irradiation on EVA. Results obtained from both gel content tests show that degree of cross-linking in amorphous regions is dependent on dose. A significant improvement in tensile strength of neat EVA samples is obtained upon electron-beam radiation up to 210 kGy. Similarly, hardness properties of Low-density polyethylene (LDPE) improvewith increasing electron beam irradiation. This article deals with the impacts of electron beam (EB) irradiation on the properties of LDPE and Ethylene-Vinyl Acetate (EVA) as the two common based formulations for wire and cable applications.

  10. Reactivity of vinyl ethers and vinyl ribosides in UV-initiated free radical copolymerization with acceptor monomers.

    PubMed

    Pichavant, Loic; Guillermain, Céline; Coqueret, Xavier

    2010-09-13

    The reactivity of various vinyl ethers and vinyloxy derivatives of ribose in the presence of diethyl fumarate or diethyl maleate was investigated for evaluating the potential of donor-acceptor-type copolymerization applied to unsaturated monomers derived from renewable feedstock. The photochemically induced polymerization of model monomer blends in the bulk state was monitored by infrared spectroscopy. The method allowed us to examine the influence of monomer pair structure on the kinetic profiles. The simultaneous consumption of both monomers was observed, supporting an alternating copolymerization mechanism. A lower reactivity of the blends containing maleates compared with fumarates was confirmed. The obtained kinetic data revealed a general correlation between the initial polymerization rate and the Hansen parameter δ(H) associated with the H-bonding aptitude of the donor monomer.

  11. Facile synthesis of electrophilic vinyl boranes: reactions of alkynyl-borates and diazonium salts.

    PubMed

    Zhao, Xiaoxi; Liang, Liyuan; Stephan, Douglas W

    2012-10-21

    Reactions of alkynylborate salts, easily derived from reaction of frustrated Lewis pairs with terminal alkynes, with diazonium salts to induce 1,1-carboboration affording a facile and efficient route to substituted electrophilic vinyl boranes.

  12. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... coloring effect. (2) As part of the manufacturing process, the lenses containing the color additives are... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction products. 73.3127 Section 73.3127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  13. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... coloring effect. (2) As part of the manufacturing process, the lenses containing the color additives are... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction products. 73.3127 Section 73.3127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  14. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... coloring effect. (2) As part of the manufacturing process, the lenses containing the color additives are... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction products. 73.3127 Section 73.3127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  15. Wax inhibitor based on ethylene vinyl acetate with methyl methacrylate and diethanolamine for crude oil pipeline

    NASA Astrophysics Data System (ADS)

    Anisuzzaman, S. M.; Abang, S.; Bono, A.; Krishnaiah, D.; Karali, R.; Safuan, M. K.

    2017-06-01

    Wax precipitation and deposition is one of the most significant flow assurance challenges in the production system of the crude oil. Wax inhibitors are developed as a preventive strategy to avoid an absolute wax deposition. Wax inhibitors are polymers which can be known as pour point depressants as they impede the wax crystals formation, growth, and deposition. In this study three formulations of wax inhibitors were prepared, ethylene vinyl acetate, ethylene vinyl acetate co-methyl methacrylate (EVA co-MMA) and ethylene vinyl acetate co-diethanolamine (EVA co-DEA) and the comparison of their efficiencies in terms of cloud point¸ pour point, performance inhibition efficiency (%PIE) and viscosity were evaluated. The cloud point and pour point for both EVA and EVA co-MMA were similar, 15°C and 10-5°C, respectively. Whereas, the cloud point and pour point for EVA co-DEA were better, 10°C and 10-5°C respectively. In conclusion, EVA co-DEA had shown the best % PIE (28.42%) which indicates highest percentage reduction of wax deposit as compared to the other two inhibitors.

  16. Cel vinyls: materials and methods.

    PubMed

    Harrison, S J

    1983-12-01

    Many commercial uses of media are applicable to medical/scientific media production and illustration, not the least of which are techniques pioneered in the commercial cartooning field. Whether or not the illustrative effort culminates in a "cartoon," the production techniques of the cartooning industry cannot be overlooked by the illustrator faced with providing projection graphics, whether animated or still, for slides, motion pictures, television or even print media. When Walt Disney introduced Mickey Mouse as "Steamboat Willie" in 1928, his technology opened the door for exploration of cartooning media by all artists. Only in comparatively recent years have these tools been used by the scientific illustrator. In this article cel vinyl acrylics or cartoon colors will be discussed: the rationale for the use of this medium, materials and methods, and considerations related to the photography of this art form.

  17. Synthesis of light-selective poly(ethylene-co-vinyl acetate) nanofilms in supercritical carbon dioxide

    NASA Astrophysics Data System (ADS)

    Xu, William (Zhiming)

    Due to the increased requirements of environmental protection, significant effort has been made to develop new "green" chemistry and engineering methods. Two effective approaches for "green" processes are: (1) to employ routes with fewer synthetic and separation steps, and (2) to replace volatile organic solvents with environmentally friendly solvents. Supercritical carbon dioxide (scCO2) has emerged as such a viable "green" alternative to organic solvents for several applications including extraction, polymerization, and nanotechnology, etc. In addition, it is an enabling solvent, allowing new types of chemistry and materials to be formed. In order to effectively utilize scCO2, it is required to study its effect on the relevant chemical process. This thesis focuses on the copolymerization of ethylene and vinyl acetate in scCO2, and the application of scCO2 in the synthesis of novel poly(vinyl acetate) (PVAc) and poly(ethylene-co-vinyl acetate) (PEVA) nanocomposites. Firstly, the kinetics of the process was investigated. The thermal decomposition of the free-radical initiator diethyl peroxydicarbonate (DEPDC) was monitored by in situ attenuate total reflection Fourier transform infrared spectroscopy (ATR-FTIR) in heptane, and in scCO2. The rate constant and activation energy of the thermal decomposition of DEPDC in scCO2 were determined, and a decomposition mechanism was proposed. Further, with a knowledge of the initiator kinetics, in situ ATR-FTIR was employed to monitor the initial formation of copolymers of ethylene and vinyl acetate during polymerization in scCO2. The reactivity ratios for the copolymerization of ethylene and vinyl acetate in scCO2 were determined using both the Kelen-Tudos and the non-linear least-squares methods. The potential of scCO2 was further examined to synthesize advanced and novel nanomaterials based on an understanding of the polymerization mechanism. A novel one-step synthesis route was developed for making silica

  18. Evaluation of the efficacy and safety of bi-daily combination therapy with pyridoxine and doxylamine for nausea and vomiting of pregnancy.

    PubMed

    Ashkenazi-Hoffnung, Liat; Merlob, Paul; Stahl, Bracha; Klinger, Gil

    2013-01-01

    Diclectin (pyridoxine 10 mg and doxylamine 10 mg) has traditionally been used to treat nausea and vomiting of pregnancy (NVP); however, this drug is unavailable in many countries. To evaluate the efficacy and safety of a simple bi-daily treatment regimen with the combination of pyridoxine (50 mg twice daily) and doxylamine (25-50 mg) as an alternative treatment for NVP. A prospective case-controlled observational study of mother-infant pairs was conducted between February 2008 and December 2010. All women who contacted the Beilinson Teratology Information Service (BELTIS) regarding treatment of NVP were eligible for inclusion. Using data on NVP severity, treatment efficacy and outcomes, we compared the two groups of women: those treated with the combination of pyridoxine and doxylamine (treatment group, n=29) and those treated with metoclopramide (control group, n=29). Moderate to severe symptoms were present in 97% of the treatment group women vs. 69% of control group women (P < 0.01). Despite increased symptom severity in the treatment group, the combination regimen was efficacious: 20/29 (69%) vs. 18/25 (72%) in the treatment vs. control women respectively (P = 0.65). There were no congenital anomalies in the treatment group. Follow-up was normal for all infants. Bi-daily combination therapy with pyridoxine and doxylamine for NVP is safe, has comparable efficacy to metoclopramide, and is a treatment alternative in countries where Diclectin is not available. Despite symptoms warranting counseling by a teratology information service, more than a third of women do not take the suggested treatment.

  19. Molecular dynamics study of HIV-1 RT-DNA-nevirapine complexes explains NNRTI inhibition and resistance by connection mutations.

    PubMed

    Vijayan, R S K; Arnold, Eddy; Das, Kalyan

    2014-05-01

    HIV-1 reverse transcriptase (RT) is a multifunctional enzyme that is targeted by nucleoside analogs (NRTIs) and non-nucleoside RT inhibitors (NNRTIs). NNRTIs are allosteric inhibitors of RT, and constitute an integral part of several highly active antiretroviral therapy regimens. Under selective pressure, HIV-1 acquires resistance against NNRTIs primarily by selecting mutations around the NNRTI pocket. Complete RT sequencing of clinical isolates revealed that spatially distal mutations arising in connection and the RNase H domain also confer NNRTI resistance and contribute to NRTI resistance. However, the precise structural mechanism by which the connection domain mutations confer NNRTI resistance is poorly understood. We performed 50-ns molecular dynamics (MD) simulations, followed by essential dynamics, free-energy landscape analyses, and network analyses of RT-DNA, RT-DNA-nevirapine (NVP), and N348I/T369I mutant RT-DNA-NVP complexes. MD simulation studies revealed altered global motions and restricted conformational landscape of RT upon NVP binding. Analysis of protein structure network parameters demonstrated a dissortative hub pattern in the RT-DNA complex and an assortative hub pattern in the RT-DNA-NVP complex suggesting enhanced rigidity of RT upon NVP binding. The connection subdomain mutations N348I/T369I did not induce any significant structural change; rather, these mutations modulate the conformational dynamics and alter the long-range allosteric communication network between the connection subdomain and NNRTI pocket. Insights from the present study provide a structural basis for the biochemical and clinical findings on drug resistance caused by the connection and RNase H mutations. Copyright © 2013 Wiley Periodicals, Inc.

  20. IRIS Toxicological Review and Summary Documents for Vinyl Chloride (External Review Draft)

    EPA Science Inventory

    The Draft Toxicological Review was developed to evaluate both the cancer and non cancer human health risks from environmental exposure to vinyl chloride. A reference concentration (RfC), and a reference dose (RfD) were developed based upon induction of liver cell polymorphism in ...

  1. Single-step synthesis of styryl phosphonic acids via palladium-catalyzed Heck coupling of vinyl phosphonic acid with aryl halides

    DOE PAGES

    McNichols, Brett W.; Koubek, Joshua T.; Sellinger, Alan

    2017-10-27

    Here, we have developed a single step palladium-catalyzed Heck coupling of aryl halides with vinyl phosphonic acid to produce functionalized (E)-styryl phosphonic acids. This pathway utilizes a variety of commercially available aryl halides, vinyl phosphonic acid and Pd(P(tBu) 3) 2 as catalyst. These conditions produce a wide range of styryl phosphonic acids with high purities and good to excellent yields (31–80%).

  2. Single-step synthesis of styryl phosphonic acids via palladium-catalyzed Heck coupling of vinyl phosphonic acid with aryl halides

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

    McNichols, Brett W.; Koubek, Joshua T.; Sellinger, Alan

    Here, we have developed a single step palladium-catalyzed Heck coupling of aryl halides with vinyl phosphonic acid to produce functionalized (E)-styryl phosphonic acids. This pathway utilizes a variety of commercially available aryl halides, vinyl phosphonic acid and Pd(P(tBu) 3) 2 as catalyst. These conditions produce a wide range of styryl phosphonic acids with high purities and good to excellent yields (31–80%).

  3. Establishment of a structure-activity relationship of 1H-imidazo[4,5-c]quinoline-based kinase inhibitor NVP-BEZ235 as a lead for African sleeping sickness.

    PubMed

    Seixas, João D; Luengo-Arratta, Sandra A; Diaz, Rosario; Saldivia, Manuel; Rojas-Barros, Domingo I; Manzano, Pilar; Gonzalez, Silvia; Berlanga, Manuela; Smith, Terry K; Navarro, Miguel; Pollastri, Michael P

    2014-06-12

    Compound NVP-BEZ235 (1) is a potent inhibitor of human phospoinositide-3-kinases and mammalian target of rapamycin (mTOR) that also showed high inhibitory potency against Trypanosoma brucei cultures. With an eye toward using 1 as a starting point for anti-trypanosomal drug discovery, we report efforts to reduce host cell toxicity, to improve the physicochemical properties, and to improve the selectivity profile over human kinases. In this work, we have developed structure-activity relationships for analogues of 1 and have prepared analogues of 1 with improved solubility properties and good predicted central nervous system exposure. In this way, we have identified 4e, 9, 16e, and 16g as the most promising leads to date. We also report cell phenotype and phospholipidomic studies that suggest that these compounds exert their anti-trypanosomal effects, at least in part, by inhibition of lipid kinases.

  4. Copper-catalyzed oxidative Heck reactions between alkyltrifluoroborates and vinyl arenes.

    PubMed

    Liwosz, Timothy W; Chemler, Sherry R

    2013-06-21

    We report herein that potassium alkyltrifluoroborates can be utilized in oxidative Heck-type reactions with vinyl arenes. The reaction is catalyzed by a Cu(OTf)2/1,10-phenanthroline with MnO2 as the stoichiometric oxidant. In addition to the alkyl Heck, amination, esterification, and dimerization reactions of alkyltrifluoroborates are demonstrated under analogous reaction conditions. Evidence for an alkyl radical intermediate is presented.

  5. Enhancement of OCT images with vinyl polysiloxane (VPS)

    NASA Astrophysics Data System (ADS)

    Kang, Hobin; Darling, Cynthia L.; Fried, Daniel

    2016-02-01

    Several studies have shown that optical coherence tomography (OCT) can be used to measure the remaining enamel thickness and detect the location of subsurface lesions hidden under the sound enamel. Moreover studies have shown that high refractive index liquids can be used to improve the visibility of subsurface lesions in OCT images. In this study, we demonstrate that vinyl polysiloxane (VPS) impression materials which are routinely used in dentistry can be used to enhance the detection of dentinal lesions on tooth occlusal surfaces. Lesion presence was confirmed with polarized light microscopy and microradiography.

  6. Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate).

    PubMed

    Suresh, Sunil S; Mohanty, Smita; Nayak, Sanjay K

    2018-06-01

    The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

  7. Palladium-Catalyzed Dynamic Kinetic Asymmetric Transformations of Vinyl Aziridines with Nitrogen Heterocycles: Rapid Access to Biologically Active Pyrroles and Indoles

    PubMed Central

    Trost, Barry M.; Osipov, Maksim; Dong, Guangbin

    2010-01-01

    We report that nitrogen heterocycles can serve as competent nucleophiles in the palladium-catalyzed dynamic kinetic asymmetric alkylation of vinyl aziridines. The resulting alkylated products were obtained with high regio-, chemo-, and enantioselectivity. Both substituted 1H-pyrroles and 1H-indoles were successfully employed to give exclusively the branched N-alkylated products. The synthetic utility of this process was demonstrated by applying this method to the preparation of several medicinal chemistry lead compounds and bromopyrrole alkaloids including longamide B, longamide B methyl ester, hanishin, agesamides A and B, and cyclooroidin. PMID:20949972

  8. Poly(vinyl alcohol) cryogel phantoms for use in ultrasound and MR imaging

    NASA Astrophysics Data System (ADS)

    Surry, K. J. M.; Austin, H. J. B.; Fenster, A.; Peters, T. M.

    2004-12-01

    Poly(vinyl alcohol) cryogel, PVA-C, is presented as a tissue-mimicking material, suitable for application in magnetic resonance (MR) imaging and ultrasound imaging. A 10% by weight poly(vinyl alcohol) in water solution was used to form PVA-C, which is solidified through a freeze-thaw process. The number of freeze-thaw cycles affects the properties of the material. The ultrasound and MR imaging characteristics were investigated using cylindrical samples of PVA-C. The speed of sound was found to range from 1520 to 1540 m s-1, and the attenuation coefficients were in the range of 0.075-0.28 dB (cm MHz)-1. T1 and T2 relaxation values were found to be 718-1034 ms and 108-175 ms, respectively. We also present applications of this material in an anthropomorphic brain phantom, a multi-volume stenosed vessel phantom and breast biopsy phantoms. Some suggestions are made for how best to handle this material in the phantom design and development process.

  9. Multi-heteroatom doped carbon coated Na3V2(PO4)3 derived from ionic liquids.

    PubMed

    Zhang, Lu-Lu; Zhou, Ying-Xian; Li, Tao; Ma, Di; Yang, Xue-Lin

    2018-03-28

    Multi-heteroatom (N, S and F) doped carbon coated Na 3 V 2 (PO 4 ) 3 (labeled as NVP/C-ILs) derived from an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM]TF2N) has been successfully fabricated. The as-prepared Na 3 V 2 (PO 4 ) 3 particles are well dispersed and closely coated with a multi-heteroatom (N, S and F) doped carbon layer. As a cathode for sodium-ion batteries, the NVP/C-ILs electrode exhibits high reversible specific capacity (117.5 mA h g -1 at 1C), superior rate performance (93.4 mA h g -1 at 10C) and excellent cycling stability (∼95% capacity retention ratio at 10C over 1000 cycles). The impressive electrochemical performance of NVP/C-ILs can be attributed to effectively conductive networks for electrons and Na + ions induced by a joint effect of N, S and F doping on carbon. The use of multi-heteroatom doped carbon coated Na 3 V 2 (PO 4 ) 3 provides a facile and effective strategy for the fabrication of high performance electrode materials with low intrinsic electrical conductivity.

  10. Changes in chemical permeation of disposable latex, nitrile, and vinyl gloves exposed to simulated movement.

    PubMed

    Phalen, Robert N; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. The aim of this study was to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time (BT) was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. Glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves.

  11. Changes in Chemical Permeation of Disposable Latex, Nitrile and Vinyl Gloves Exposed to Simulated Movement

    PubMed Central

    Phalen, Robert N.; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. This study was aimed to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. In conclusion, glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves. PMID:24689368

  12. Microstructure and molecular interaction in glycerol plasticized chitosan/poly(vinyl alcohol) blending films

    USDA-ARS?s Scientific Manuscript database

    Poly (vinyl alcohol) (PVA)/chitosan (CS) blended films plasticized by glycerol were investigated using mechanical testing, atomic force microscopy (AFM), differential scanning calorimetry (DSC) and FTIR spectroscopy, with primary emphasis on the effects of the glycerol content and the molecular weig...

  13. Role of Rilpivirine and Etravirine in Efavirenz and Nevirapine-Based Regimens Failure in a Resource-Limited Country: A Cross- Sectional Study.

    PubMed

    Teeranaipong, Phairote; Sirivichayakul, Sunee; Mekprasan, Suwanna; Ohata, Pirapon June; Avihingsanon, Anchalee; Ruxrungtham, Kiat; Putcharoen, Opass

    2016-01-01

    Etravirine(ETR) can be used for patients who have failed NNRTI-based regimen. In Thailand, ETR is approximately 45 times more expensive than rilpivirine(RPV). However, there are no data of RPV use in NNRTI failure. Therefore, we assessed the susceptibility and mutation patterns of first line NNRTI failure and the possibility of using RPV compared to ETV in patients who have failed efavirenz(EFV)- and nevirapine(NVP)-based regimens. Clinical samples with confirmed virological failure from EFV- or NVP-based regimens were retrospectively analyzed. Resistance-associated mutations (RAMs) were interpreted by IAS-USA Drug Resistance Mutations. Susceptibility of ETR and RPV were interpreted by DUET, Monogram scoring system, and Stanford University HIV Drug Resistance Database. 1,279 and 528 patients failed EFV- and NVP-based regimens, respectively. Y181C was the most common NVP-associated RAM (54.3% vs. 14.7%, p<0.01). K103N was the most common EFV-associated RAM (56.5% vs. 19.1%, P<0.01). The results from all three scoring systems were concordant. 165(11.1%) and 161(10.9%) patients who failed NVP-based regimen were susceptible to ETR and RPV, respectively (p = 0.85). 195 (32.2%) and 191 (31.6%) patients who failed EFV-based regimen, were susceptible to ETR and RPV, respectively (p = 0.79). The susceptibility of ETV and RPV in EFV failure was significantly higher than NVP failure (p<0.01). The mutation patterns for ETR and RPV were similar but 32% and 11% of patients who failed EFV and NVP -based regimen, respectivly were susceptible to RPV. This finding suggests that RPV can be used as the alternative antiretroviral agent in patients who have failed EFV-based regimen.

  14. Cell-Penetrating CaCO3 Nanocrystals for Improved Transport of NVP-BEZ235 across Membrane Barrier in T-Cell Lymphoma

    PubMed Central

    Civallero, Monica; Citti, Cinzia; Cosenza, Maria; Baldassarre, Francesca; Cannazza, Giuseppe; Pozzi, Samantha; Sacchi, Stefano

    2018-01-01

    Owing to their nano-sized porous structure, CaCO3 nanocrystals (CaCO3NCs) hold the promise to be utilized as desired materials for encapsulating molecules which demonstrate wide promise in drug delivery. We evaluate the possibility to encapsulate and release NVP-BEZ235, a novel and potent dual PI3K/mTOR inhibitor that is currently in phase I/II clinical trials for advanced solid tumors, from the CaCO3NCs. Its chemical nature shows some intrinsic limitations which induce to administer high doses leading to toxicity; to overcome these problems, here we proposed a strategy to enhance its intracellular penetration and its biological activity. Pristine CaCO3 NCs biocompatibility, cell interactions and internalization in in vitro experiments on T-cell lymphoma line, were studied. Confocal microscopy was used to monitor NCs-cell interactions and cellular uptake. We have further investigated the interaction nature and release mechanism of drug loaded/released within/from the NCs using an alternative approach based on liquid chromatography coupled to mass spectrometry. Our approach provides a good loading efficiency, therefore this drug delivery system was validated for biological activity in T-cell lymphoma: the anti-proliferative test and western blot results are very interesting because the proposed nano-formulation has an efficiency higher than free drug at the same nominal concentration. PMID:29370086

  15. The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate).

    PubMed

    Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V; Domínguez-Aguilar, Marco A; Lijanova, Irina V; Arce-Estrada, Elsa

    2014-08-07

    Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC 12 ), poly(1-vinyl-3-octylimidazolium) (PImC₈) and poly(1-vinyl-3-butylimidazolium) (PImC₄) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1-1 M H₂SO₄) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir's isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC 12 > PImC₈ > PImC₄) to reach 61% for PImC 12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs' partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

  16. Thermal dissociation and relaxation in vinyl fluoride, 1,1-difluoroethane and 1,3,5-triazine

    NASA Astrophysics Data System (ADS)

    Xu, Hui

    This study reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500--2000 K and 43 < P < 424 torr. The product vinyl then dissociates affecting the late density gradient. We include a laser schlieren study (1717--2332 K, 75 < P < 482 torr in 10% and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass-spectrometry (4% vinyl fluoride in neon, 1500--1980 K, 500 < P < 1300 torr), which confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The relaxation experiments (1--20% C2H3F in Kr, 415--1975 K, 5 < P < 50 torr, and 2% and 5% C2H4F2 in Kr, 700--1350 K, 6 < P < 22 torr) exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. A RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large down of 1600cm-1 . Dissociation of vinyl fluoride has two parallel HF eliminations both three-center and four-center with nearly equal barriers. An RRKM fit to the observed falloff again requires an unusually large down and the experiments actually support a slightly reduced barrier. Both 1,3,5-triazine and pyrazine relax extremely rapidly with energy transfer in a few collisions, any incubation delay can be confidently discounted in dissociation. 1,3,5-triazine dissociation experiments show fall-off with a clear pressure dependence. The three body product dissociation mechanism models this dissociation perfectly. Experimental data agree well with an RRKM calculation using a down of 1200cm-1 and a barrier E0 = 84.66 kcal/mol. Dyakov et al. suggested lower barrier of E0 = 81 kcal/mole. The new RRKM calculation using this barrier seems a better

  17. Acetogenic microbial degradation of vinyl chloride

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.

    2000-01-01

    Under methanogenic conditions, microbial degradation of [1,2-14C]vinyl chloride (VC) resulted in significant (14 ?? 3% maximum recovery) but transient recovery of radioactivity as 14C-acetate. Subsequently, 14C- acetate was degraded to 14CH4 and 14CO2 (18 ?? 2% and 54 ?? 3% final recoveries, respectively). In contrast, under 2-bromoethanesulfonic acid (BES) amended conditions, 14C-acetate recovery remained high (27 ?? 1% maximum recovery) throughout the study, no 14CH4 was produced, and the final recovery of 14CO2 was only 35 ?? 4%. These results demonstrate that oxidative acetogenesis may be an important mechanism for anaerobic VC biodegradation. Moreover, these results (1) demonstrate that microbial degradation of VC to CH4 and CO2 may involve oxidative acetogenesis followed by acetotrophic methanogenesis and (2) suggest that oxidative acetogenesis may be the initial step in the net oxidation of VC to CO2 reported previously under Fe(III)-reducing, SO4-reducing, and humic acids- reducing conditions.Under methanogenic conditions, microbial degradation of [1,2-14C]vinyl chloride (VC) resulted in significant (14 ?? 3% maximum recovery) but transient recovery of radioactivity as 14C-acetate. Subsequently, 14C-acetate was degraded to 14CH4 and 14CO2 (18 ?? 2% and 54 ?? 3% final recoveries respectively). In contrast, under 2-bromoethanesulfonic acid (BES) amended conditions, 14C-acetate recovery remained high (27 ?? 1% maximum recovery) throughout the study, no 14CH4 was produced, and the final recovery of 14CO2 was only 35 ?? 4%. These results demonstrate that oxidative acetogenesis may be an important mechanism for anaerobic VC biodegradation. Moreover, these results (1) demonstrate that microbial degradation of VC to CH4 and CO2 may involve oxidative acetogenesis followed by acetotrophic methanogenesis and (2) suggest that oxidative acetogenesis may be the initial step in the net oxidation of VC to CO2 reported previously under Fe(III)-reducing, SO4-reducing, and

  18. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring - A Mechanistic Analysis

    EPA Science Inventory

    A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Adsorption isotherms for phthalates and plasticizers on interior ...

  19. 40 CFR 721.10044 - Metal oxide, modified with alkyl and vinyl terminated polysiloxanes (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and vinyl terminated polysiloxanes (PMN P-02-698) is subject to reporting under this section for the... specified in § 721.125 (a), (b), (c), and (i) are applicable to manufacturers, importers, and processors of...

  20. Interaction between poly(vinyl pyrrolidone) PVP and fullerene C60 at the interface in PVP-C60 nanofluids–A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Behera, M.; Ram, S.

    2018-03-01

    Fourier transform infrared and Raman bands shows a discernible enhancement in band intensity of C–H stretching, C=O stretching, C–N stretching, C–H2 bending, and C–H2 in-plane bending in PVP molecules in the presence of C60 molecules. Amplification in intensity is ascribed to microscopic interactions results when a donation of nonbonding electron (n) occurs from a “>N–C=O” entity of PVP into a lowest unoccupied molecular orbital of the C60 molecule in PVP-C60 charge transfer (CT) complex. The C=O stretching band intensity (integrated) Vs C60 content plot exhibits a peak near a critical 13.9 μM C60 value owing to percolation effect. Light emission spectra show that even a small addition of 4.63 μM C60 able to suppress the band intensity by ~23% as a result of an energy loss. The integrated band intensity also decreases through a peak near 13.9 μM when plotted against the C60-content. In correlation to the vibration spectra, the maximum effect observed both in light emission and excitation spectra suggests a percolation effect in the CT complex. Exhibition of percolation threshold in C60-PVP donor-acceptor complex will be helpful in optimizing the photovoltaic properties vital for solar cell applications.

  1. Nanocomposite scaffold with enhanced stability by hydrogen bonds between collagen, polyvinyl pyrrolidone and titanium dioxide.

    PubMed

    Li, Na; Fan, Xialian; Tang, Keyong; Zheng, Xuejing; Liu, Jie; Wang, Baoshi

    2016-04-01

    In this study, three-dimensional (3D) nanocomposite scaffolds, as potential substrates for skin tissue engineering, were fabricated by freeze drying the mixture of type I collagen extracted from porcine skin and polyvinyl pyrrolidone (PVP)-coated titanium dioxide (TiO2) nanoparticles. This procedure was performed without any cross-linker or toxic reagents to generate porosity in the scaffold. Both morphology and thermal stability of the nanocomposite scaffold were examined. The swelling behavior, mechanical properties and hydrolytic degradation of the composite scaffolds were carefully investigated. Our results revealed that collagen, PVP and TiO2 are bonded together by four main hydrogen bonds, which is an essential action for the formation of nanocomposite scaffold. Using Coasts-Redfern model, we were able to calculate the thermal degradation apparent activation energy and demonstrated that the thermal stability of nanocomposites is dependent on amount of PVP incorporated. Furthermore, SEM images showed that the collagen fibers are wrapped and stabilized on scaffolds by PVP molecules, which improve the ultimate tensile strength (UTS). The UTS of PVP-contained scaffold is four times higher than that of scaffold without PVP, whereas ultimate percentage of elongation (UPE) is decreased, and PVP can enhance the degradation resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Immobilization of Platinum Nanoparticles on 3,4-diaminobenzoyl-Functionalized Multi-Walled Carbon Nanotube and its Electrocatalytic Activity

    DTIC Science & Technology

    2012-01-01

    solvents, such as ethanol , N-methyl-2-pyrrolidone, and methanesulfonic acid. The absorption and emission properties of DAB- MWCNT in solution state are...MWCNT) are highly dispersible in polar solvents, such as ethanol N-methyl-2-pyrrolidone, and methanesulfonic acid. The absorption and emission properties...oxidized defects on the CNTs are probable sites for deactivation of transition metal catalysts (Wildgoose et al. 2006). Hence, the development of a

  3. Effect of hydroxyapatite on the biodegradation and biomechanical stability of polyester nanocomposites for orthopaedic applications.

    PubMed

    Jayabalan, M; Shalumon, K T; Mitha, M K; Ganesan, K; Epple, M

    2010-03-01

    The effect of hydroxyapatite (HAP) on the performance of nanocomposites of an unsaturated polyester, i.e., hydroxy-terminated high molecular weight poly(proplyene fumarate) (HT-PPFhm), was investigated. A thermoset nanocomposite was prepared with nanoparticles of calcined HAP (<100 nm, rod-like shape, filler content 30 wt.%), HT-PPFhm and N-vinyl pyrrolidone, dibenzoyl peroxide and N,N-dimethyl aniline. Two more nanocomposites were prepared with precipitated HAP nanoparticles (<100 nm rod-like shape) and commercially available HAP nanoparticles (<200 nm spherical shape), respectively. Calcined HAP nanoparticles resulted in very good crosslinking in the resin matrix with high crosslinking density and interfacial bonding with the polymer, owing to the rod-like shape of the nanoparticles; this gave improved biomechanical strength and modulus and also controlled degradation of the nanocomposite for scaffold formation. The tissue compatibility and osteocompatibility of the nanocomposite containing calcined HAP nanoparticles was evaluated. The tissue compatibility was studied by intramuscular implantation in a rabbit animal model for 3 months as per ISO standard 10993/6. The in vivo femoral bone repair was also carried out in the rabbit animal model as per ISO standard 10993/6. The nanocomposite containing calcined HAP nanoparticles is both biocompatible and osteocompatible. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Evasion of the accelerated blood clearance phenomenon by coating of nanoparticles with various hydrophilic polymers.

    PubMed

    Ishihara, Tsutomu; Maeda, Taishi; Sakamoto, Haruka; Takasaki, Naoko; Shigyo, Masao; Ishida, Tatsuhiro; Kiwada, Hiroshi; Mizushima, Yutaka; Mizushima, Tohru

    2010-10-11

    The accelerated blood clearance (ABC) phenomenon is induced upon repeated injections of poly(ethylene glycol) (PEG)-coated colloidal carriers. It is essential to suppress this phenomenon in a clinical setting because the pharmacokinetics must be reproducible. In this study, we evaluated the induction of the ABC phenomenon using nanoparticles coated with various hydrophilic polymers instead of PEG. Nanoparticles encapsulating prostaglandin E1 were prepared by the solvent diffusion method from a blend of poly(lactic acid) (PLA) and block copolymers consisting of various hydrophilic polymers and PLA. Coating of nanoparticles with poly(N-vinyl-2-pyrrolidone) (PVP), poly(4-acryloylmorpholine), or poly(N,N-dimethylacrylamide) led to extended residence of the nanoparticles in blood circulation in rats, although they had a shorter half-life than the PEG-coated nanoparticles. The ABC phenomenon was not induced upon repeated injection of PVP-coated nanoparticles at various time intervals, dosages, or frequencies, whereas it was elicited by PEG-coated nanoparticles. In addition, anti-PVP IgM antibody, which is estimated to be one of the crucial factors for induction of the ABC phenomenon, was not produced after injection of PVP-coated nanoparticles. These results suggest that the use of PVP, instead of PEG, as a coating material for colloidal carriers can evade the ABC phenomenon.

  5. Effects of pore CaCO3 form agencies on dissolution mechanisms of amoxicillin drugs encapsulated in hydrogels full-IPN chitosan N-vinyl caprolactam

    NASA Astrophysics Data System (ADS)

    Budianto, Emil; Fauzia, Maghfira

    2018-04-01

    The administration of amoxicillin trihydrate in Helicobacter pylori infection is not effective enough because the conventional preparations used have a short retention time in the stomach. To overcome this problem, amoxicillin trihydrate was encapsulated into the floating drug delivery matrix-matrix. In this study, the full-ipn acetaldehyde crosslinked hydrogel (N-vinyl caprolactam) was synthesized with a 10% CaCO3 pore forming agent and then encapsulated on amoxicillin trihydrate and studied the mechanism of drug dissolution with its kinetic kinetics approach. The K-PNVCL Hydrogel produces optimal properties which are then loaded with amoxicillin trihydrate in situ and post loading. In this research, we have got the percentage of swelling, floating time, the efficiency of in situ and post loading 873%; 3.15 minutes; 99.8% and 99.4%. The dissolution test was performed on amoxicillin trihydrate which had been encapsulated K-PNVCL hydrogel in vitro at pH 1.2 resulting in 94.5% for in situ loading and 98.5% for post loading. Results of the kinetics of drug release for post loading and in situ loading methods tend to follow the Higuchi model kinetics. The drug release mechanism occurs by Fickian diffusion. Proof of drug release mechanism from K-PNVCL hydrogel matrix is further done by Scanning Electron Microscope (SEM) instrument.

  6. Hydroacylation of 2-vinyl benzaldehyde systems: an efficient method for the synthesis of chiral 3-substituted indanones.

    PubMed

    Kundu, Kousik; McCullagh, James V; Morehead, Andrew T

    2005-11-23

    Asymmetric rhodium-catalyzed hydroacylation has been utilized in the synthesis of 3-substituted indanones with high conversions and enantioselectivity. The hydroacylation reaction of 2-vinyl benzaldehyde had been previously reported to give a low yield of indanone and an unidentified product. We have identified this compound as a dimer of the starting material. Substitution at the alpha-position of the 2-vinyl benzaldehyde substrates blocks the competitive dimerization reaction and allows the reaction to proceed with yields generally greater than 90%. Utilization of BINAP as a chiral ligand results in good chemical yields and enantioselectivity greater than 95% in most cases.

  7. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Perfluoroalkylethyl methacrylate... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl... subject to reporting. (1) The chemical substance identified generically as perfluoroalkylethyl...

  8. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Perfluoroalkylethyl methacrylate... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl... subject to reporting. (1) The chemical substance identified generically as perfluoroalkylethyl...

  9. 21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... chemical reactions, other than addition reactions, occur when they are mixed. (2) Polymers identified in...; provided that no chemical reactions, other than addition reactions, occur when they are combined. Such..., other than addition reactions, occur among the vinyl chloride polymers and the modifying polymers...

  10. 21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... chemical reactions, other than addition reactions, occur when they are mixed. (2) Polymers identified in...; provided that no chemical reactions, other than addition reactions, occur when they are combined. Such..., other than addition reactions, occur among the vinyl chloride polymers and the modifying polymers...

  11. Polymer surfaces structured with random or aligned electrospun nanofibers to promote the adhesion of blood platelets.

    PubMed

    Wan, Ling-Shu; Xu, Zhi-Kang

    2009-04-01

    Fibrous membranes (nonwoven meshes) prepared via electrospinning technique have great potential in tissue engineering. This work is the first study on the behaviors of blood platelets at the nanostructured surface generated by electrospinning. Poly[acrylonitrile-co-(N-vinyl-2-pyrrolidone)] (PANCNVP) that shows excellent antiplatelet adhesion ability was directly electrospun onto its dense membrane surface. Polyacrylonitrile (PAN) samples were used as controls. The depth as well as the density of the nanofibers can be easily controlled. The results showed that the PANCNVP dense membrane certainly suppressed the activation and adhesion of platelets. However, whether the nanofibers and underlying membranes were composed of PAN or PANCNVP, the nanostructured surfaces promoted the activation, adhesion, and orientation of platelets. It was also found that, if the space between fibers was too large or the depth of fibers was too small, the nanostructured surface did not change the property of antiplatelet adhesion of PANCNVP. The promotion of activation and adhesion of platelets was obviously due to the presence of nanofibers, which induced the changes of surface topography and charge. Copyright 2008 Wiley Periodicals, Inc.

  12. Arginine-glycine-aspartic acid functional branched semi-interpenetrating hydrogels.

    PubMed

    Plenderleith, Richard A; Pateman, Christopher J; Rodenburg, Cornelia; Haycock, John W; Claeyssens, Frederik; Sammon, Chris; Rimmer, Stephen

    2015-10-14

    For the first time a series of functional hydrogels based on semi-interpenetrating networks with both branched and crosslinked polymer components have been prepared and we show the successful use of these materials as substrates for cell culture. The materials consist of highly branched poly(N-isopropyl acrylamide)s with peptide functionalised end groups in a continuous phase of crosslinked poly(vinyl pyrrolidone). Functionalisation of the end groups of the branched polymer component with the GRGDS peptide produces a hydrogel that supports cell adhesion and proliferation. The materials provide a new synthetic functional biomaterial that has many of the features of extracellular matrix, and as such can be used to support tissue regeneration and cell culture. This class of high water content hydrogel material has important advantages over other functional hydrogels in its synthesis and does not require post-processing modifications nor are functional-monomers, which change the polymerisation process, required. Thus, the systems are amenable to large scale and bespoke manufacturing using conventional moulding or additive manufacturing techniques. Processing using additive manufacturing is exemplified by producing tubes using microstereolithography.

  13. Polymerization Behavior and Polymer Properties of Eosin-Mediated Surface Modification Reactions.

    PubMed

    Avens, Heather J; Randle, Thomas James; Bowman, Christopher N

    2008-10-17

    Surface modification by surface-mediated polymerization necessitates control of the grafted polymer film thicknesses to achieve the desired property changes. Here, a microarray format is used to assess a range of reaction conditions and formulations rapidly in regards to the film thicknesses achieved and the polymerization behavior. Monomer formulations initiated by eosin conjugates with varying concentrations of poly(ethylene glycol) diacrylate (PEGDA), N-methyldiethanolamine (MDEA), and 1-vinyl-2-pyrrolidone (VP) were evaluated. Acrylamide with MDEA or ascorbic acid as a coinitiator was also investigated. The best formulation was found to be 40 wt% acrylamide with MDEA which yielded four to eight fold thicker films (maximum polymer thickness increased from 180 nm to 1420 nm) and generated visible films from 5-fold lower eosin surface densities (2.8 vs. 14 eosins/µm(2)) compared to a corresponding PEGDA formulation. Using a microarray format to assess multiple initiator surface densities enabled facile identification of a monomer formulation that yields the desired polymer properties and polymerization behavior across the requisite range of initiator surface densities.

  14. Polymerization Behavior and Polymer Properties of Eosin-Mediated Surface Modification Reactions

    PubMed Central

    Avens, Heather J.; Randle, Thomas James; Bowman, Christopher N.

    2008-01-01

    Surface modification by surface-mediated polymerization necessitates control of the grafted polymer film thicknesses to achieve the desired property changes. Here, a microarray format is used to assess a range of reaction conditions and formulations rapidly in regards to the film thicknesses achieved and the polymerization behavior. Monomer formulations initiated by eosin conjugates with varying concentrations of poly(ethylene glycol) diacrylate (PEGDA), N-methyldiethanolamine (MDEA), and 1-vinyl-2-pyrrolidone (VP) were evaluated. Acrylamide with MDEA or ascorbic acid as a coinitiator was also investigated. The best formulation was found to be 40 wt% acrylamide with MDEA which yielded four to eight fold thicker films (maximum polymer thickness increased from 180 nm to 1420 nm) and generated visible films from 5-fold lower eosin surface densities (2.8 vs. 14 eosins/µm2) compared to a corresponding PEGDA formulation. Using a microarray format to assess multiple initiator surface densities enabled facile identification of a monomer formulation that yields the desired polymer properties and polymerization behavior across the requisite range of initiator surface densities. PMID:19838291

  15. Copper nanocoils synthesized through solvothermal method

    PubMed Central

    Liu, Yanjuan; Liu, Xiaowei; Zhan, Yongjie; Fan, Haiming; Lu, Yang

    2015-01-01

    Recently helical nanostructures such as nanosprings and nanocoils have drawn great interests in nanotechnology, due to their unique morphologies and physical properties, and they may be potential building blocks in sorts of electromechanical, magnetic, photoelectronic and plasmonic devices at micro/nanoscales. In this report, multi-turns copper nanocoils were synthesized through a modified solvothermal method, in which the mixture of water and N-methyl-2-pyrrolidone (NMP) were selected as reaction medium and copolymer poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP/VA 64E) as reductant. In the liquid solution, nanosprings could be formed from relaxed nanocoils and demonstrated high elasticity. These nanocoils and nanosprings are of single crystalline structure, with the characteristics wire diameters ranging from tens to a few hundreds of nanometers and the ring/coil diameters mostly ~10–35 microns. Their growth and deformation mechanisms were then investigated and discussed along with that of previously reported single-turn copper nanorings. This work could be of importance for researchers working on synthesis and applications of novel 1-D helical nanomaterials and their functional devices. PMID:26607386

  16. Stereoselective Synthesis of trans-Olefins by the Copper-Mediated SN2′ Reaction of Vinyl Oxazines with Grignard Reagents. Asymmetric Synthesis of D-threo-Sphingosines

    PubMed Central

    Singh, Om V.; Han, Hyunsoo

    2007-01-01

    The SN2′ reaction of 6-vinyl-5,6-dihydro-4H-[1,3]oxazines with Grignard reagents in the presence of CuCN was studied, and high trans selectivity for the formation of double bond was observed with a variety of RMgX. The SN2′ reaction, coupled with regioselective asymmetric aminohydroxylation reaction, provided a highly efficient route for the asymmetric synthesis of D-threo-N-acetylsphingosine. PMID:18958293

  17. ALMA Spectroscopy of Titan's Atmosphere: First Detections of Vinyl Cyanide and Acetonitrile Isotopologues

    NASA Astrophysics Data System (ADS)

    Cordiner, Martin; Y Palmer, Maureen; Nixon, Conor A.; Charnley, Steven B.; Mumma, Michael J.; Irwin, Pat G. J.; Teanby, Nick A.; Kisiel, Zbigniew; Serigano, Joseph

    2015-11-01

    Studies of Titan's atmospheric chemistry provide a unique opportunity to explore the origin and evolution of complex organic matter in primitive planetary atmospheres. The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful new telescope, well suited to the study of molecular emission from Titan's stratosphere and mesosphere. Here we present early results from our ongoing study to exploit the large volume of Titan data taken using ALMA in Early Science Mode (during the period 2012-2014). Combining data from multiple ALMA Band 6 observations, we obtained high-resolution mm-wave spectra with unprecedented sensitivity, enabling the first detection of vinyl cyanide (C2H3CN) in Titan's atmosphere. Initial estimates indicate a mesospheric abundance ratio with respect to ethyl cyanide (C2H5CN) of [C2H3CN]/[C2H5CN] = 0.31. In addition, we report the first detections on Titan of the 13C and 15N-substituted isotopologues of acetonitrile (13CH3CN and CH3C15N). Radiative transfer models and possible chemical formation pathways for these molecules will be discussed.

  18. Silk fibroin/poly (vinyl alcohol) blend scaffolds for controlled delivery of curcumin

    PubMed Central

    Li, Xiaomeng; Qin, Jinli; Ma, Jun

    2015-01-01

    A silk fibroin/poly (vinyl alcohol) porous scaffold with a water vapor transmission rate of 2125 ± 464 g/m2/day has been developed via thermally induced phase separation (gelation) and freeze-drying process. A hierarchical architecture of micropores and nanofibers was observed inside the scaffolds, and the related structures were analyzed. The viability and proliferation of 3T3 fibroblasts were examined, which indicated that the scaffolds exerted low cytotoxicity. After loading curcumin, the scaffolds can suppress the growth of 3T3 fibroblasts. The release behavior of curcumin from the scaffolds was investigated. At pH = 7.2, the release profiles showed no significant difference for the loading amounts of 0.5 mg and 0.25 mg per sample. Meanwhile, the cumulative amount of released drug at pH = 5.7 was significantly more than that in neutral solution due to more degradation of the scaffolds. It was suggested that the silk fibroin/poly (vinyl alcohol) blend scaffolds could be potentially used as wound dressing materials. PMID:26816634

  19. Photodissociation Dynamics of Vinyl Cyanide Studied by Chirped-Pulse Millimeter-Wave Spectroscopy of HCN and HNC Products

    NASA Astrophysics Data System (ADS)

    Prozument, Kirill; Shaver, Rachel G.; Baraban, Joshua H.; Park, G. Barratt; Suits, Arthur G.; Muenter, John S.; Field, Robert W.

    2013-06-01

    Vinyl cyanide 193 nm photodissociation has been studied using Chirped-Pulse Millimeter-Wave (CPmmW) spectroscopy. J = 0 - 1 transitions of more than 30 vibrationally excited states of the HCN and HNC products have been recorded and assigned within the 7 GHz wide chirp range. Bending excitations of HCN up to v_2 = 14, leading toward the HCN leftrightarrow HNC isomerization transition state, are detected and interpreted in terms of their electric quadrupole, (eQq)_{N}, and rotational, B_v, constants. The photolysis reaction transition states were probed using both normal vinyl cyanide, CH_2=CHCN, and its singly-deuterated isotopologue, CH_2=CDCN. The observed difference in the vibrational population distribution (VPD) obtained from the integrated intensities of the HCN and DCN products from the CH_2=CHCN vs. CH_2=CDCN photolysis reactions, suggests the relative unimportance of the three-center elimination mechanism for HCN production. On the other hand, the similarity in the observed VPD and overall intensities of HCN from CH_2=CHCN and CH_2=CDCN photolysis suggests four-center elimination as the major mechanism leading to the HCN product. Additional J - (J + 1) transitions would be required to characterize both the vibrational and the rotational state distributions of the products, which would permit more complete characterization of the transition state(s). The authors thank the Department of Energy, and KP thanks the ACS Petroleum Research Fund for their support of this work.

  20. Vinyl fluoride as an isoelectronic replacement for an enolate anion: inhibition of type II dehydroquinases.

    PubMed

    Frederickson, Martyn; Coggins, John R; Abell, Chris

    2002-09-07

    A vinyl fluoride analogue of the intermediate in the reaction catalysed by type II dehydroquinase enzymes has been synthesized over seven steps from (-)-quinic acid and shown to be a potent enzyme inhibitor.

  1. In vitro assessment of competitive and time-dependent inhibition of the nevirapine metabolism by nortriptyline in rats.

    PubMed

    Usach, Iris; Ferrer, José-Maria; Peris, José-Esteban

    2018-04-17

    Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) widely used as a component of High Active Antiretroviral Therapy (HAART) since it is inexpensive, readily absorbed after oral administration and non-teratogenic. In the present work, the mechanism of a previously described pharmacokinetic interaction between NVP and the antidepressant drug nortriptyline (NT) was studied using rat hepatic microsomes. The obtained results showed a competitive inhibition of the NVP metabolism by NT. The three main NVP metabolites (2-OH-NVP, 3-OH-NVP and 12-OH-NVP) where competitively inhibited with similar inhibitory constant values (K i  = 4.01, 3.97 and 4.40 μM, respectively). Time-dependent inhibition of the NVP metabolism was also detected, with a 2.5-fold reduction in the IC 50 values of NT for 2-, 3-, and 12-OH-NVP formation when NT was preincubated with the microsomal suspension in the presence of an NADPH-generating system. A concentration-dependent inhibition of the formation of NVP metabolites by the main NT metabolite (10-OH-NT) was also observed, however, the inhibitory potency of 10-OH-NT was much lower than that of the parent drug. The apparent hepatic intrinsic clearance of NVP determined in these in vitro experiments was used to predict the in vivo clearance of NVP using the "well-stirred" and the "parallel-tube" models, resulting in values close to those previously observed in vivo clearance. Finally, a good prediction of the increase in the plasma concentrations of NVP when co-administered with NT was obtained employing the inhibitory constant of NT determined in vitro and the estimated plasma concentration of NT entering the liver. Copyright © 2018. Published by Elsevier Inc.

  2. The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate)

    PubMed Central

    Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V.; Domínguez-Aguilar, Marco A.; Lijanova, Irina V.; Arce-Estrada, Elsa

    2014-01-01

    Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC12), poly(1-vinyl-3-octylimidazolium) (PImC8) and poly(1-vinyl-3-butylimidazolium) (PImC4) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4) to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions. PMID:28788156

  3. Influence of Block Copolymerization on the Antifreeze Protein Mimetic Ice Recrystallization Inhibition Activity of Poly(vinyl alcohol).

    PubMed

    Congdon, Thomas R; Notman, Rebecca; Gibson, Matthew I

    2016-09-12

    Antifreeze (glyco) proteins are produced by many cold-acclimatized species to enable them to survive subzero temperatures. These proteins have multiple macroscopic effects on ice crystal growth which makes them appealing for low-temperature applications-from cellular cryopreservation to food storage. Poly(vinyl alcohol) has remarkable ice recrystallization inhibition activity, but its mode of action is uncertain as is the extent at which it can be incorporated into other high-order structures. Here the synthesis and characterization of well-defined block copolymers containing poly(vinyl alcohol) and poly(vinylpyrrolidone) by RAFT/MADIX polymerization is reported, as new antifreeze protein mimetics. The effect of adding a large second hydrophilic block is studied across a range of compositions, and it is found to be a passive component in ice recrystallization inhibition assays, enabling retention of all activity. In the extreme case, a block copolymer with only 10% poly(vinyl alcohol) was found to retain all activity, where statistical copolymers of PVA lose all activity with very minor changes to composition. These findings present a new method to increase the complexity of antifreeze protein mimetic materials, while retaining activity, and also to help understand the underlying mechanisms of action.

  4. Influence of Block Copolymerization on the Antifreeze Protein Mimetic Ice Recrystallization Inhibition Activity of Poly(vinyl alcohol)

    PubMed Central

    2016-01-01

    Antifreeze (glyco) proteins are produced by many cold-acclimatized species to enable them to survive subzero temperatures. These proteins have multiple macroscopic effects on ice crystal growth which makes them appealing for low-temperature applications—from cellular cryopreservation to food storage. Poly(vinyl alcohol) has remarkable ice recrystallization inhibition activity, but its mode of action is uncertain as is the extent at which it can be incorporated into other high-order structures. Here the synthesis and characterization of well-defined block copolymers containing poly(vinyl alcohol) and poly(vinylpyrrolidone) by RAFT/MADIX polymerization is reported, as new antifreeze protein mimetics. The effect of adding a large second hydrophilic block is studied across a range of compositions, and it is found to be a passive component in ice recrystallization inhibition assays, enabling retention of all activity. In the extreme case, a block copolymer with only 10% poly(vinyl alcohol) was found to retain all activity, where statistical copolymers of PVA lose all activity with very minor changes to composition. These findings present a new method to increase the complexity of antifreeze protein mimetic materials, while retaining activity, and also to help understand the underlying mechanisms of action. PMID:27476873

  5. Catalytic Arylation and Vinylation Reactions Directed by Anionic Oxygen Functions via Cleavage of C - H and C - C Bonds

    NASA Astrophysics Data System (ADS)

    Satoh, Tetsuya; Miura, Masahiro

    Aromatic compounds having oxygen-containing substituents such as phenols, phenyl ketones, benzyl alcohols, and benzoic acids undergo regioselective arylation and vinylation via C-H bond cleavage in the presence of transition-metal catalysts. The latter two substrates are also arylated and vinylated via C-C bond cleavage accompanied by liberation of ketones and CO2, respectively. Coordination of their anionic oxygen to the metal center is the key to activate the inert bonds effectively and regioselectively. The recent progress of these oxygen-directed reactions is summarized herein.

  6. Synergistic anti-tumor effect of 17AAG with the PI3K/mTOR inhibitor NVP-BEZ235 on human melanoma.

    PubMed

    Calero, R; Morchon, E; Martinez-Argudo, I; Serrano, R

    2017-10-10

    Drug resistance by MAPK signaling recovery or activation of alternative signaling pathways, such as PI3K/AKT/mTOR, is an important factor that limits the long-term efficacy of targeted therapies in melanoma patients. In the present study, we investigated the phospho-proteomic profile of RTKs and its correlation with downstream signaling pathways in human melanoma. We found that tyrosine kinase receptors expression correlated with the expression of pivotal downstream components of the RAS/RAF/MAPK and PI3K/AKT/mTOR pathways in melanoma cell lines and tumors. We also found high expression of HSP90 and the PI3K/AKT/mTOR pathway proteins, 4EBP1 and AKT compared with healthy tissue and this correlated with poor overall survival of melanoma patients. The combination of the HSP90 inhibitor 17AAG with the PI3K/mTOR inhibitor NVP-BEZ235 showed a synergistic activity decreasing melanoma cell growth, inducing apoptosis and targeting simultaneously the MAPK and PI3K/AKT/mTOR pathways. These results demonstrate that the combination of HSP90 and PI3K/mTOR inhibitors could be an effective therapeutic strategy that target the main survival pathways in melanoma and must be considered to overcome resistance to BRAF inhibitors in melanoma patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Nevirapine bioactivation and covalent binding in the skin.

    PubMed

    Sharma, Amy M; Klarskov, Klaus; Uetrecht, Jack

    2013-03-18

    Nevirapine (NVP) treatment is associated with serious skin rashes that appear to be immune-mediated. We previously developed a rat model of this skin rash that is immune-mediated and is very similar to the rash in humans. Treatment of rats with the major NVP metabolite, 12-OH-NVP, also caused the rash. Most idiosyncratic drug reactions are caused by reactive metabolites; 12-OH-NVP forms a benzylic sulfate, which was detected in the blood of animals treated with NVP or 12-OH-NVP. This sulfate is presumably formed in the liver; however, the skin also has significant sulfotransferase activity. In this study, we used a serum against NVP to detect covalent binding in the skin of rats. There was a large artifact band in immunoblots of whole skin homogenates that interfered with detection of covalent binding; however, when the skin was separated into dermal and epidermal fractions, covalent binding was clearly present in the epidermis, which is also the location of sulfotransferases. In contrast to rats, treatment of mice with NVP did not result in covalent binding in the skin or skin rash. Although the reaction of 12-OH-NVP sulfate with nucleophiles such as glutathione is slow, incubation of this sulfate with homogenized human and rat skin led to extensive covalent binding. Incubations of 12-OH-NVP with the soluble fraction from a 9,000g centrifugation (S9) of rat or human skin homogenate in the presence of 3'-phosphoadenosine-5'-phosphosulfate (PAPS) produced extensive covalent binding, but no covalent binding was detected with mouse skin S9, which suggests that the reason mice do not develop a rash is that they lack the required sulfotransferase. This is the first study to report covalent binding of NVP to rat and human skin. These data provide strong evidence that covalent binding of NVP in the skin is due to 12-OH-NVP sulfate, which is likely responsible for NVP-induced skin rash. Sulfation may represent a bioactivation pathway for other drugs that cause a skin rash.

  8. Identification of danger signals in nevirapine-induced skin rash.

    PubMed

    Zhang, Xiaochu; Sharma, Amy M; Uetrecht, Jack

    2013-09-16

    Nevirapine (NVP) can cause serious skin rashes and hepatotoxicity. It also causes an immune-mediated skin rash in rats but not hepatotoxicity. This rash is caused by a metabolite of NVP; specifically, NVP is oxidized in the liver to a benzylic alcohol (12-OH-NVP), which travels to the skin where it forms a reactive benzylic sulfate. This could both act as a hapten and induce a danger signal. In contrast, most of the covalent binding in the liver involves oxidation of the methyl group leading to a reactive quinone methide. In this study, we examined the effects of NVP and 12-OH-NVP on gene expression in the liver and skin. Both NVP and 12-OH-NVP induced changes in the liver, but the list of genes was different, presumably reflecting different bioactivation pathways. In contrast, many more genes were up-regulated in the skin by 12-OH-NVP than by NVP, which is consistent with the fact that 12-OH-NVP is an obligate intermediate in the formation of the reactive sulfate in the skin. Genes up-regulated by 12-OH-NVP in the skin included TRIM63 (18-fold increase), S100a7a (7-fold increase), IL22-RA2 (4-fold increase), and DAPK1 (3-fold increase). TRIM63 acts as a ubiquitin ligase, which is consistent with protein damage leading to an increase in protein turnover. In addition, TRIM proteins are involved in inflammasome activation, and it appears that inflammasome activation is an essential step in the induction of NVP-induced skin rash. S100A7 is considered a danger signal, and its upregulation supports the danger hypothesis. Upregulation of the IL-22 RA2 gene marks an immune response. DAPK1 is involved with inflammasome assembly through binding directly to NLRP3, a NOD-like receptor expressed in keratinocytes. These results provide important clues to how NVP causes the induction of an immune response, in this case leading to skin rash.

  9. Photoinduced charge-carrier modulation of inkjet-printed carbon nanotubes via poly(vinyl acetate) doping and dedoping for thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Horike, Shohei; Fukushima, Tatsuya; Saito, Takeshi; Koshiba, Yasuko; Ishida, Kenji

    2018-01-01

    Here, we studied the charge-carrier modulation of single-walled carbon nanotubes (SWCNTs) via poly(vinyl acetate) (PVAc) doping and dedoping under ultraviolet (UV) light irradiation with the aim of pairing several p- and n-type SWCNTs as thermoelectric (TE) elements. The Seebeck coefficient of the SWCNTs was first made negative by doping with PVAc and then made positive again through UV-induced PVAc dedoping. A possible TE module configuration and the process for its fabrication are proposed, wherein prints and photopatterns can be obtained without the use of additional electrodes. Our findings enable the fabrication of fine TE modules using simple materials and techniques.

  10. Gold nanoparticles-decorated electrospun poly(N-vinyl-2-pyrrolidone) nanofibers with tunable size and coverage density for nanomolar detection of single and binary component dyes by surface-enhanced raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Kurniawan, Alfin; Wang, Meng-Jiy

    2017-09-01

    The application of the electrospun nanomaterials to surface-enhanced Raman spectroscopy (SERS) is a rapidly evolving field which holds potential for future developments in the generation of portable plasmonic-based detection platforms. In this study, a simple approach to fabricate electrospun poly(N-vinylpyrrolidone) (PVP) mats decorated with gold nanoparticles (AuNPs) by combining electrospinning and calcination was presented. AuNPs were decorated on the fiber mat surface through electrostatic interactions between positively charged aminosilane groups and negatively charged AuNPs. The size and coverage density of AuNPs on the fiber mats could be tuned by varying the calcination temperature. Calcination of AuNPs-decorated PVP fibers at 500 °C-700 °C resulted in the uniform decoration of high density AuNPs with very narrow gaps on every single fiber, which in turn contribute to strong electromagnetic SERS enhancement. The robust free-standing AuNPs-decorated mat which calcined at 500 °C (500/AuNPs-F) exhibited high SERS activity toward cationic (methylene blue, MB) and anionic (methyl orange, MO) dyes in single and binary systems with a detection range from tens of nM to a few hundred μM. The fabricated SERS substrate demonstrated high reproducibility with the spot-to-spot variation in SERS signal intensities was ±10% and ±12% for single and binary dye systems, respectively. The determination of MB and MO in spiked river water and tap water with 500/AuNPs-F substrate gave satisfactory results in terms of the percent spike recoveries (ranging from 92.6%-96.6%) and reproducibility (%RSD values less than 15 for all samples).

  11. Impact of Maternal and Infant Antiretroviral Drug Regimens on Drug Resistance in HIV-Infected Breastfeeding Infants

    PubMed Central

    Fogel, Jessica M.; Mwatha, Anthony; Richardson, Paul; Brown, Elizabeth R.; Chipato, Tsungai; Alexandre, Michel; Moodley, Dhayendre; Elbireer, Ali; Mirochnick, Mark; George, Kathleen; Mofenson, Lynne M.; Zwerski, Sheryl; Coovadia, Hoosen M.; Eshleman, Susan H.

    2013-01-01

    BACKGROUND The HPTN 046 trial evaluated the efficacy of extended infant nevirapine (NVP) administration for prevention of HIV transmission through breastfeeding. Infants received daily NVP to 6 weeks of age. HIV-uninfected infants (the intent-to-treat group) received daily NVP or placebo up to 6 months of age. We analyzed emergence of NVP resistance in infants who acquired HIV-infection despite prophylaxis. METHODS HIV genotyping was performed using the ViroSeq HIV Genotyping System. Medians and proportions were used to summarize data. Two-sided Fisher’s exact tests were used to evaluate associations between categorical variables. RESULTS NVP resistance was detected in 12 (92.3%) of 13 infants who were HIV-infected by 6 weeks and in seven (28%) of 25 infants who were HIV-uninfected at 6 weeks and HIV-infected at 6 months of age (6/8=75% in the NVP arm, 1/17=5.9% in the placebo arm, P=0.001). Among those 25 infants, 4 had mothers who initiated an antiretroviral (ARV) treatment regimen by 6 months postpartum. In all 4 cases, the treatment regimen included a non-nucleoside reverse transcriptase inhibitor (NVP or efavirenz). NVP resistance was detected in all four of those infants by 6 months of age (4/4=100%). In contrast, only three (14.2%) of the remaining 21 HIV-infected infants whose mothers did not initiate ARV treatment developed NVP resistance (P=0.003). CONCLUSIONS Extended NVP prophylaxis significantly increased the risk of NVP resistance in infants who acquired HIV infection after 6 weeks of age. Treatment of maternal HIV infection was also associated with emergence of NVP resistance in HIV-infected, breastfed infants. PMID:23249916

  12. Impact of maternal and infant antiretroviral drug regimens on drug resistance in HIV-infected breastfeeding infants.

    PubMed

    Fogel, Jessica M; Mwatha, Anthony; Richardson, Paul; Brown, Elizabeth R; Chipato, Tsungai; Alexandre, Michel; Moodley, Dhayendre; Elbireer, Ali; Mirochnick, Mark; George, Kathleen; Mofenson, Lynne M; Zwerski, Sheryl; Coovadia, Hoosen M; Eshleman, Susan H

    2013-04-01

    The HIV Prevention Trials Network (HPTN) 046 trial evaluated the efficacy of extended infant nevirapine (NVP) administration for prevention of HIV transmission through breastfeeding. Infants received daily NVP up to 6 weeks of age. HIV-uninfected infants (the intent-to-treat group) received daily NVP or placebo up to 6 months of age. We analyzed emergence of NVP resistance in infants who acquired HIV infection despite prophylaxis. HIV genotyping was performed using the ViroSeq HIV Genotyping System. Medians and proportions were used to summarize data. Two-sided Fisher exact tests were used to evaluate associations between categorical variables. NVP resistance was detected in 12 (92.3%) of 13 infants who were HIV-infected by 6 weeks and in 7 (28%) of 25 infants who were HIV-uninfected at 6 weeks and HIV-infected at 6 months of age (6/8 = 75% in the NVP arm, 1/17 = 5.9% in the placebo arm, P = 0.001). Among those 25 infants, 4 had mothers who initiated an antiretroviral treatment regimen by 6 months postpartum. In all 4 cases, the treatment regimen included a non-nucleoside reverse transcriptase inhibitor (NVP or efavirenz). NVP resistance was detected in all 4 of those infants by 6 months of age (4/4 = 100%). In contrast, only 3 (14.2%) of the remaining 21 HIV-infected infants whose mothers did not initiate antiretroviral treatment developed NVP resistance (P = 0.003). Extended NVP prophylaxis significantly increased the risk of NVP resistance in infants who acquired HIV infection after 6 weeks of age. Treatment of maternal HIV infection was also associated with emergence of NVP resistance in HIV-infected, breastfed infants.

  13. Heat shock protein 90 inhibitor NVP-AUY922 exerts potent activity against adult T-cell leukemia–lymphoma cells

    PubMed Central

    Taniguchi, Hiroaki; Hasegawa, Hiroo; Sasaki, Daisuke; Ando, Koji; Sawayama, Yasushi; Imanishi, Daisuke; Taguchi, Jun; Imaizumi, Yoshitaka; Hata, Tomoko; Tsukasaki, Kunihiro; Uno, Naoki; Morinaga, Yoshitomo; Yanagihara, Katsunori; Miyazaki, Yasushi

    2014-01-01

    Adult T-cell leukemia–lymphoma (ATL), an aggressive neoplasm etiologically associated with HTLV-1, is a chemoresistant malignancy. Heat shock protein 90 (HSP90) is involved in folding and functions as a chaperone for multiple client proteins, many of which are important in tumorigenesis. In this study, we examined NVP-AUY922 (AUY922), a second generation isoxazole-based non-geldanamycin HSP90 inhibitor, and confirmed its effects on survival of ATL-related cell lines. Analysis using FACS revealed that AUY922 induced cell-cycle arrest and apoptosis; it also inhibited the growth of primary ATL cells, but not of normal PBMCs. AUY922 caused strong upregulation of HSP70, a surrogate marker of HSP90 inhibition, and a dose-dependent decrease in HSP90 client proteins associated with cell survival, proliferation, and cell cycle in the G1 phase, including phospho-Akt, Akt, IKKα, IKKβ, IKKγ, Cdk4, Cdk6, and survivin. Interestingly, AUY922 induced downregulation of the proviral integration site for Moloney murine leukemia virus (PIM) in ATL cells. The PIM family (PIM-1, -2, -3) is made up of oncogenes that encode a serine/threonine protein kinase family. As PIM kinases have multiple functions involved in cell proliferation, survival, differentiation, apoptosis, and tumorigenesis, their downregulation could play an important role in AUY922-induced death of ATL cells. In fact, SGI-1776, a pan-PIM kinase inhibitor, successfully inhibited the growth of primary ATL cells as well as ATL-related cell lines. Our findings suggest that AUY922 is an effective therapeutic agent for ATL, and PIM kinases may be a novel therapeutic target. PMID:25263741

  14. Vinyl azides derived from allenes: thermolysis leading to multisubstituted 1,4-pyrazines and Mn(III)-catalyzed photochemical reaction leading to pyrroles.

    PubMed

    Sajna, K V; Kumara Swamy, K C

    2012-10-05

    Thermolysis of phosphorus-based vinyl azides under solvent- and catalyst-free conditions furnished a new route for 1,4-pyrazines. A simple one-pot, Mn(III)-catalyzed photochemical route has been developed for multisubstituted pyrroles starting from allenes and 1,3-dicarbonyls via in situ-generated vinyl azides. The utility of new phosphorus-based pyrroles is also demonstrated in the Horner reaction. The structures of key products are unequivocally confirmed by X-ray crystallography.

  15. Nevirapine patch testing in Thai human immunodeficiency virus infected patients with nevirapine drug hypersensitivity.

    PubMed

    Prasertvit, Piyatida; Chareonyingwattana, Angkana; Wattanakrai, Penpun

    2017-12-01

    Antiretroviral drug hypersensitivity in HIV patients is common. Publications have shown that Abacavir (ABC) patch testing is useful in confirming ABC hypersensitivity in 24-50% of cases with a 100% sensitivity of HLA-B*5701 in patch test positive cases. However, Nevirapine (NVP) patch testing has not been reported. (1) To evaluate the usefulness and safety of NVP patch testing in Thai HIV patients with NVP hypersensitivity. (2) To assess the correlation of positive patch tests with HLA-B*3505. Patients were classified into two groups: (1) study group of 20 HIV NVP hypersensitivity patients and (2) control group of 15 volunteers without NVP hypersensitivity. Both groups were patch tested with purified and commercialized form of NVP in various vehicles. Two HIV patients with NVP hypersensitivity were patch test positive. All controls tested negative. Three HIV patients were positive for HLA-B*3505 and the two patients with positive patch testing were both HLA-B*3505 positive. NVP patch testing in Thai HIV patients is safe and can be used to help confirm the association between NVP and hypersensitivity skin reactions. NVP patch test results significantly correlated with HLA-B*3505. The sensitivity of HLA-B*3505 for positive patch test was 100%. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Prediction of Protein Modification Sites of Pyrrolidone Carboxylic Acid Using mRMR Feature Selection and Analysis

    PubMed Central

    Zheng, Lu-Lu; Niu, Shen; Hao, Pei; Feng, KaiYan; Cai, Yu-Dong; Li, Yixue

    2011-01-01

    Pyrrolidone carboxylic acid (PCA) is formed during a common post-translational modification (PTM) of extracellular and multi-pass membrane proteins. In this study, we developed a new predictor to predict the modification sites of PCA based on maximum relevance minimum redundancy (mRMR) and incremental feature selection (IFS). We incorporated 727 features that belonged to 7 kinds of protein properties to predict the modification sites, including sequence conservation, residual disorder, amino acid factor, secondary structure and solvent accessibility, gain/loss of amino acid during evolution, propensity of amino acid to be conserved at protein-protein interface and protein surface, and deviation of side chain carbon atom number. Among these 727 features, 244 features were selected by mRMR and IFS as the optimized features for the prediction, with which the prediction model achieved a maximum of MCC of 0.7812. Feature analysis showed that all feature types contributed to the modification process. Further site-specific feature analysis showed that the features derived from PCA's surrounding sites contributed more to the determination of PCA sites than other sites. The detailed feature analysis in this paper might provide important clues for understanding the mechanism of the PCA formation and guide relevant experimental validations. PMID:22174779

  17. Poly(vinyl benzoate) nanoparticles for molecular delivery: Studies on their preparation and in vitro properties.

    PubMed

    Labruère, Raphaël; Sicard, Renaud; Cormier, Ryan; Turos, Edward; West, Leigh

    2010-12-01

    The preparation and properties of poly(vinyl benzoate) nanoparticle suspensions as molecular carriers are described for the first time. These nanoparticles can be formed by nanoprecipitation of commercial poly(vinyl benzoate) in water using Pluronic F68 as surfactant, to create spherical nanostructures measuring 200-250nm in diameter. These nanoparticles are stable in phosphate buffer and blood serum, and only slowly degrade in the presence of esterases. Pluronic F68 stabilizes the nanoparticle and also protects it from enzymatic degradation. Up to 1.6% by weight of a lipid-soluble molecule such as coumarin-6 can be introduced into the nanoparticle during nanoprecipitation, compared to a water-soluble compound (5(6)-carboxyfluorescein) which gave almost no loading. Kinetics experiments in phosphate buffer indicate that 78% of the coumarin-6 was encapsulated within the polymer matrix of the nanoparticle, and the residual 22% of coumarin-6 was surface-bound and quickly released. The nanoparticles are non-toxic in vitro towards human epithelial cells (IC(50)>1000μg/mL) and primary bovine aortic endothelial cells (IC(50)>500μg/mL), and non-bactericidal against a selection of representative test microbes (MIC >250μg/mL). These properties suggest that the poly(vinyl benzoate) nanoparticles may be suitable carriers for molecular delivery of lipophilic small molecules such as pharmaceutical and imaging agents. Copyright © 2010. Published by Elsevier B.V.

  18. Sex differences in hepatic and intestinal contributions to nevirapine biotransformation in rats.

    PubMed

    Pinheiro, P F; Marinho, A T; Antunes, A M M; Marques, M M; Pereira, S A; Miranda, J P

    2015-05-25

    The understanding of the intestine contribution to drug biotransformation improved significantly in recent years. However, the sources of inter-individual variability in intestinal drug biotransformation, namely sex-differences, are still elusive. Nevirapine (NVP) is an orally taken anti-HIV drug associated with severe idiosyncratic reactions elicited by toxic metabolites, with women at increased risk. As such, NVP is a good model to assess sex-dimorphic metabolism. The aim of this study was to perform a comparative profiling of NVP biotransformation in rat intestine and liver and evaluate whether or not it is organ- and sex-dependent. Therefore, nevirapine-containing solutions were perfused through the intestine, in a specially designed chamber, or incubated with liver slices, from male and female Wistar rats. The levels of NVP and its Phase I metabolites were quantified by HPLC-UV. Liver incubation experiments yielded the metabolites 2-, 3-, 8-, and 12-OH-NVP, being 12-OH-NVP and 2-OH-NVP the major metabolites in males and females, respectively. Inter-sex differences in the metabolic profile were also detected in the intestine perfusion experiments. Herein, the metabolites 3- and 12-OH-NVP were only found in male rats, whereas 2-OH-NVP levels were higher in females, both in extraluminal (p<0.01) and intraluminal media. The metabolite 8-OH-NVP was not detected in the intraluminal media from either males or females. In this study, important inter-sex differences were detected in both organs, providing further clues to the sex-dimorphic profile of NVP toxicity. Moreover, an extra-hepatic contribution to NVP biotransformation was observed, strengthening the relevance of the intestinal contribution in the biotransformation of orally taken-drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Long-term neurodevelopment of children exposed to maternal nausea and vomiting of pregnancy and diclectin.

    PubMed

    Nulman, Irena; Rovet, Joanne; Barrera, Maru; Knittel-Keren, Dafna; Feldman, Brian M; Koren, Gideon

    2009-07-01

    To determine the effects of nausea and vomiting of pregnancy (NVP) and its treatment with diclectin on child neurodevelopment. An observational cohort study of mother-child pairs ascertained via a pregnancy call-in center was conducted. Three groups of children were studied: 45 with NVP and diclectin, 47 with NVP no diclectin, and 29 with no NVP. Phone calls to mothers during pregnancy and 6 to 9 months after childbirth yielded information on pregnancy, birth, and early child development. Children aged 3 to 7 years received a comprehensive set of psychological tests. Mothers were assessed for IQ and socioeconomic status. All children scored in the normal range for IQ, with the NVP-exposed group scoring higher than the non-exposed group on Performance IQ (P < .02), NEPSY Verbal Fluency (P < .003) and Phonological Processing (P < .004), and McCarthy Numerical Memory (P < .004). Predictors of enhanced results were NVP severity and maternal IQ. NVP has an enhancing effect on later child outcome. Diclectin does not appear to adversely affect fetal brain development and can be used to control NVP when clinically indicated.

  20. Synthesis of Lipophilic Antioxidants by a Lipase-B-Catalyzed Addition of Peracids to the Double Bond of 4-Vinyl-2-methoxyphenol.

    PubMed

    Zago, Erika; Durand, Erwann; Barouh, Nathalie; Lecomte, Jérôme; Villeneuve, Pierre; Aouf, Chahinez

    2015-10-21

    4-Vinyl guaiacol (2) was lipophilized through the electrophilic addition of peracids to its vinylic double bond. Those peracids were formed in situ, by the Candida antarctica lipase-B-assisted perhydrolysis of carboxylic acids ranging from C2 to C18, in hydrogen peroxide solution. The addition of peracids with 4-8 carbons in their alkyl chains led to the formation of two regioisomers, with the prevalence of hydroxyesters bearing a primary free hydroxyl (4c-4e). This prevalence became more pronounced when peracids with longer alkyl chains (C10-C18) were used. In this case, only isomers 4f-4h were formed. The antioxidant activity of the resulting hydroxyesters was assessed by means of the conjugated autoxidizable triene (CAT) assay, and it was found out that the 4-vinyl guaiacol antioxidant activity was significantly increased by grafting alkyl chains with 2-8 carbons.

  1. The burden of nausea and vomiting during pregnancy: severe impacts on quality of life, daily life functioning and willingness to become pregnant again - results from a cross-sectional study.

    PubMed

    Heitmann, Kristine; Nordeng, Hedvig; Havnen, Gro C; Solheimsnes, Anja; Holst, Lone

    2017-02-28

    Though nausea and vomiting is very common during pregnancy, no studies have investigated the impact of this condition on the women's daily lives in a Scandinavian population. The aim of this study was to describe the burden of nausea and vomiting during pregnancy (NVP) on global quality of life, daily life functioning and willingness to become pregnant again according to the severity of NVP symptoms. This study is a cross-sectional population-based study conducted in Norway. Pregnant women and mothers with children <1 year of age with current or prior NVP were eligible to participate. Data were collected through an anonymous on-line questionnaire accessible from November 10 th , 2014 to January 31 st , 2015. Severity of NVP was measured using the 24-h Pregnancy Unique Quantification of Emesis Scale (PUQE). Associations between severity of NVP, daily life functioning and willingness to become pregnant again were tested using chi-square tests. Associations with global quality of life measured in terms of the Quality of Life Scale (QOLS) were estimated using generalized linear models and reported as unstandardized regression coefficients (β) with 95% confidence intervals (CI). 712 women with NVP were included in the study. NVP was significantly associated with several characteristics, including daily life functioning, quality of life and willingness to become pregnant again. The negative impact was greater the more severe the symptoms were, although considerable adverse effects were also seen among women with mild and moderate NVP symptoms. Over one fourth of the women with severe NVP considered terminating the pregnancy due to NVP, and three in four considered not to get pregnant again. Severity of NVP remained significantly associated with reduced global quality of life when adjusting for maternal characteristics and illnesses with β (95% CI) = -10.9 (-16.9, -4.9) for severe versus mild NVP. NVP as measured by PUQE had a major impact on various aspects of the

  2. Mortality experience of workers exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride in Great Britain.

    PubMed Central

    Fox, A J; Collier, P F

    1977-01-01

    Identification particulars were obtained for over 7000 men who were at some time between 1940 and 1974 exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride. Approximately 99% of these men have been traced and their mortality experience studied. The overall standardised mortality ratio, 75-4, shows a significant reduction compared with the national rates. Four cases of liver cancer were found. Two of these have been confirmed by a panel of liver pathologists as angiosarcoma and two as not angiosarcoma. There is no evidence to support the hypothesis that cancers other than those of the liver are associated with exposure to vinyl chloride monomer. The two cases of angiosarcoma were found in men who had been exposed to high concentrations of the monomer although the second man died only eight years after first exposure. The industry in Great Britain has expanded considerably since the second world war with over 50% of men having entered with the last decade. Conclusions drawn about the effect of vinyl chloride monomer on the mortality experience of men in this industry must consequently be tempered by the reservation that the full impact may not yet be in evidence. PMID:557328

  3. NOVEL METALLIC AND BIMETALLIC CROSS-LINKED POLY (VINYL ALCOHOL) NANOCOMPOSITES PREPARED UNDER MICROWAVE IRRADIATION

    EPA Science Inventory

    A facile microwave irradiation approach that results in a cross-linking reaction of poly (vinyl alcohol) (PVA) with metallic and bimetallic systems is described. Nanocomposites of PVA cross-linked metallic systems such as Pt, Cu, and In and bimetallic systems such as Pt-In, Ag-P...

  4. Bioorthogonal Metabolic DNA Labelling using Vinyl Thioether-Modified Thymidine and o-Quinolinone Quinone Methide.

    PubMed

    Gubu, Amu; Li, Long; Ning, Yan; Zhang, Xiaoyun; Lee, Seonghyun; Feng, Mengke; Li, Qiang; Lei, Xiaoguang; Jo, Kyubong; Tang, Xinjing

    2018-04-17

    Bioorthogonal metabolic DNA labeling with fluorochromes is a powerful strategy to visualize DNA molecules and their functions. Here, we report the development of a new DNA metabolic labeling strategy enabled by the catalyst-free bioorthogonal ligation using vinyl thioether modified thymidine and o-quinolinone quinone methide. With the newly designed vinyl thioether-modified thymidine (VTdT), we added labeling tags on cellular DNA, which could further be linked to fluorochromes in cells. Therefore, we successfully visualized the DNA localization within cells as well as single DNA molecules without other staining reagents. In addition, we further characterized this bioorthogonal DNA metabolic labeling using DNase I digestion, MS characterization of VTdT as well as VTdT-oQQF conjugate in cell nuclei or mitochondria. This technique provides a powerful strategy to study DNA in cells, which paves the way to achieve future spatiotemporal deciphering of DNA synthesis and functions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Radiation stability of resveratrol in immobilization on poly vinyl pyrrolidone hydrogel dressing for dermatological use

    NASA Astrophysics Data System (ADS)

    Momesso, Roberta G. R. A. P.; Moreno, Carolina S.; Rogero, Sizue O.; Rogero, José R.; Spencer, Patrick J.; Lugão, Ademar B.

    2010-03-01

    The polyphenol trans-resveratrol is a natural phytoalexin, which is found in red wine and in a wide variety of plant species. Resveratrol displays a wide array of biological activities, such as modulation of lipid metabolism, anti-inflammatory and antioxidant activities. This active compound immobilized in polyvinylpyrrolidone (PVP) hydrogel could be very interesting for topical administration, as a dressing form for dermatological use. However, PVP hydrogel obtained by radiation-induced crosslinking can cause undesirable hydrolysis reactions in the active compound. The aim of this work was to verify the resveratrol stability after irradiation at 0.5 and 1 kGy in the presence of ethanol, methanol or tert-butyl alcohol. The integrity of these samples was compared to unirradiated resveratrol by HPLC. The PVP hydrogel matrix was characterized by gel fraction, swelling and in vitro biocompatibility test. The results of gel fraction and swelling degree were approximately 90% and 1600%, respectively. The cytotoxicity assay showed absence of toxicity for this formulation after crosslinking and sterilization, indicating that the PVP hydrogel formulation was appropriate for resveratrol immobilization to produce a dressing for dermatological use.

  6. Uranium Adsorbent Fibers Prepared by Atom-Transfer Radical Polymerization (ATRP) from Poly(vinyl chloride)- co -chlorinated Poly(vinyl chloride) (PVC- co -CPVC) Fiber

    DOE PAGES

    Brown, Suree; Yue, Yanfeng; Kuo, Li-Jung; ...

    2016-03-11

    The need to secure future supplies of energy attracts researchers in several countries to a vast resource of nuclear energy fuel: uranium in seawater (estimated at 4.5 billion tons in seawater). In this study, we developed effective adsorbent fibers for the recovery of uranium from seawater via atom-transfer radical polymerization (ATRP) from a poly-(vinyl chloride)-co-chlorinated poly(vinyl chloride) (PVC-co-CPVC) fiber. ATRP was employed in the surface graft polymerization of acrylonitrile (AN) and tert-butyl acrylate (tBA), precursors for uranium-interacting functional groups, from PVC-co-CPVC fiber. The [tBA]/[AN] was systematically varied to identify the optimal ratio between hydrophilic groups (from tBA) and uranyl-binding ligandsmore » (from AN). The best performing adsorbent fiber, the one with the optimal [tBA]/[AN] ratio and a high degree of grafting (1390%), demonstrated uranium adsorption capacities that are significantly greater than those of the Japan Atomic Energy Agency (JAEA) reference fiber in natural seawater tests (2.42 3.24 g/kg in 42 days of seawater exposure and 5.22 g/kg in 49 days of seawater exposure, versus 1.66 g/kg in 42 days of seawater exposure and 1.71 g/kg in 49 days of seawater exposure for JAEA). Lastly, adsorption of other metal ions from seawater and their corresponding kinetics were also studied. The grafting of alternative monomers for the recovery of uranium from seawater is now under development by this versatile technique of ATRP.« less

  7. Uranium Adsorbent Fibers Prepared by Atom-Transfer Radical Polymerization (ATRP) from Poly(vinyl chloride)- co -chlorinated Poly(vinyl chloride) (PVC- co -CPVC) Fiber

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

    Brown, Suree; Yue, Yanfeng; Kuo, Li-Jung

    The need to secure future supplies of energy attracts researchers in several countries to a vast resource of nuclear energy fuel: uranium in seawater (estimated at 4.5 billion tons in seawater). In this study, we developed effective adsorbent fibers for the recovery of uranium from seawater via atom-transfer radical polymerization (ATRP) from a poly-(vinyl chloride)-co-chlorinated poly(vinyl chloride) (PVC-co-CPVC) fiber. ATRP was employed in the surface graft polymerization of acrylonitrile (AN) and tert-butyl acrylate (tBA), precursors for uranium-interacting functional groups, from PVC-co-CPVC fiber. The [tBA]/[AN] was systematically varied to identify the optimal ratio between hydrophilic groups (from tBA) and uranyl-binding ligandsmore » (from AN). The best performing adsorbent fiber, the one with the optimal [tBA]/[AN] ratio and a high degree of grafting (1390%), demonstrated uranium adsorption capacities that are significantly greater than those of the Japan Atomic Energy Agency (JAEA) reference fiber in natural seawater tests (2.42 3.24 g/kg in 42 days of seawater exposure and 5.22 g/kg in 49 days of seawater exposure, versus 1.66 g/kg in 42 days of seawater exposure and 1.71 g/kg in 49 days of seawater exposure for JAEA). Lastly, adsorption of other metal ions from seawater and their corresponding kinetics were also studied. The grafting of alternative monomers for the recovery of uranium from seawater is now under development by this versatile technique of ATRP.« less

  8. Uranium Adsorbent Fibers Prepared by Atom-Transfer Radical Polymerization (ATRP) from Poly(vinyl chloride)- co -chlorinated Poly(vinyl chloride) (PVC- co -CPVC) Fiber

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

    Brown, Suree; Yue, Yanfeng; Kuo, Li-Jung

    The need to secure future supplies of energy attracts researchers in several countries to a vast resource of nuclear energy fuel: uranium in seawater (estimated at 4.5 billion tons in seawater). In this study, we developed effective adsorbent fibers for the recovery of uranium from seawater via atom-transfer radical polymerization (ATRP) from a poly- (vinyl chloride)-co-chlorinated poly(vinyl chloride) (PVC-co-CPVC) fiber. ATRP was employed in the surface graft polymerization of acrylonitrile (AN) and tert-butyl acrylate (tBA), precursors for uranium-interacting functional groups, from PVC-co-CPVC fiber. The [tBA]/[AN] was systematically varied to identify the optimal ratio between hydrophilic groups (from tBA) and uranyl-bindingmore » ligands (from AN). The best performing adsorbent fiber, the one with the optimal [tBA]/[AN] ratio and a high degree of grafting (1390%), demonstrated uranium adsorption capacities that are significantly greater than those of the Japan Atomic Energy Agency (JAEA) reference fiber in natural seawater tests (2.42-3.24 g/kg in 42 days of seawater exposure and 5.22 g/kg in 49 days of seawater exposure, versus 1.66 g/kg in 42 days of seawater exposure and 1.71 g/kg in 49 days of seawater exposure for JAEA). Adsorption of other metal ions from seawater and their corresponding kinetics were also studied. The grafting of alternative monomers for the recovery of uranium from seawater is now under development by this versatile technique of ATRP.« less

  9. Treatments for hyperemesis gravidarum and nausea and vomiting in pregnancy: a systematic review and economic assessment.

    PubMed

    O'Donnell, Amy; McParlin, Catherine; Robson, Stephen C; Beyer, Fiona; Moloney, Eoin; Bryant, Andrew; Bradley, Jennifer; Muirhead, Colin; Nelson-Piercy, Catherine; Newbury-Birch, Dorothy; Norman, Justine; Simpson, Emma; Swallow, Brian; Yates, Laura; Vale, Luke

    2016-10-01

    -three studies (75 reports) met the inclusion criteria. For RCTs, 33 and 11 studies had a low and high risk of bias respectively. For the remainder ( n  = 20) it was unclear. The non-randomised studies ( n  = 9) were low quality. There were 33 separate comparators. The most common were acupressure versus placebo ( n  = 12); steroid versus usual treatment ( n  = 7); ginger versus placebo ( n  = 6); ginger versus vitamin B6 ( n  = 6); and vitamin B6 versus placebo ( n  = 4). There was evidence that ginger, antihistamines, metoclopramide (mild disease) and vitamin B6 (mild to severe disease) are better than placebo. Diclectin ® [Duchesnay Inc.; doxylamine succinate (10 mg) plus pyridoxine hydrochloride (10 mg) slow release tablet] is more effective than placebo and ondansetron is more effective at reducing nausea than pyridoxine plus doxylamine. Diclectin before symptoms of NVP begin for women at high risk of severe NVP recurrence reduces risk of moderate/severe NVP compared with taking Diclectin once symptoms begin. Promethazine is as, and ondansetron is more, effective than metoclopramide for severe NVP/HG. I.v. fluids help correct dehydration and improve symptoms. Dextrose saline may be more effective at reducing nausea than normal saline. Transdermal clonidine patches may be effective for severe HG. Enteral feeding is effective but extreme method treatment for very severe symptoms. Day case management for moderate/severe symptoms is feasible, acceptable and as effective as inpatient care. For all other interventions and comparisons, evidence is unclear. The economic analysis was limited by lack of effectiveness data, but comparison of costs between treatments highlights the implications of different choices. The main limitations were the quantity and quality of the data available. There was evidence of some improvement in symptoms for some treatments, but these data may not be transferable across disease severities. Methodologically sound and

  10. Superabsorbent hydrogel composite based on copolymer cellulose/poly (vinyl alcohol)/CNT

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

    Khoerunnisa, Fitri, E-mail: fitri.khoerunnisa@gmail.com; Hendrawan,; Sonjaya, Yaya

    2016-04-19

    Superabsorbent hydrogels are cross-linked hydrophilic polymers that can absorb and retain a large volume of water, saline solution, or physiological fluids. A distinctive superabsorbent hydrogel composite based on cellulose/ poly (vinyl alcohol)/ carbon nanotubes was successfully synthesized via the graft bio-copolymerization in an aqueous medium with glutaraldehide as a crosslinking agent. The effect of carbon nanotubes (CNT) on water absorption capacity and mechanical properties of superabsorbent composite were particularly investigated. The Fourier transform infrared spectra showed the evidence of copolymerization of hydrogel precursors as well as the interaction of CNT filler with the hydrogel matrices, as indicated by the shiftingmore » of peak intensity and position of several functional groups (O-H, C-H sp{sup 3}, C=O, C-N, C-O). The modification of hydrogel surface morphology and porosity owing to CNT insertion was also confirmed by scanning electron microscopy images. The CNT insertion improved the mechanical strength of superabsorbent hydrogel composites. Moreover, insertion of CNT into hydrogel matrix remarkably increased the swelling capacity of superabsorbent composites up to 840%. This huge water absorption capacity of hydrogel composites offers promising applications in development of superabsorbent polymers.« less

  11. Physicochemical characteristics of Fe3O4 magnetic nanocomposites based on Poly(N-isopropylacrylamide) for anti-cancer drug delivery.

    PubMed

    Davaran, Soodabeh; Alimirzalu, Samira; Nejati-Koshki, Kazem; Nasrabadi, Hamid Tayef; Akbarzadeh, Abolfazl; Khandaghi, Amir Ahmad; Abbasian, Mojtaba; Alimohammadi, Somayeh

    2014-01-01

    Hydrogels are a class of polymers that can absorb water or biological fluids and swell to several times their dry volume, dependent on changes in the external environment. In recent years, hydrogels and hydrogel nanocomposites have found a variety of biomedical applications, including drug delivery and cancer treatment. The incorporation of nanoparticulates into a hydrogel matrix can result in unique material characteristics such as enhanced mechanical properties, swelling response, and capability of remote controlled actuation. In this work, synthesis of hydrogel nanocomposites containing magnetic nanoparticles are studied. At first, magnetic nanoparticles (Fe3O4) with an average size 10 nm were prepared. At second approach, thermo and pH-sensitive poly (N-isopropylacrylamide -co-methacrylic acid-co-vinyl pyrrolidone) (NIPAAm-MAA- VP) were prepared. Swelling behavior of co-polymer was studied in buffer solutions with different pH values (pH=5.8, pH=7.4) at 37 °C. Magnetic iron oxide nanoparticles (Fe3O4) and doxorubicin were incorporated into copolymer and drug loading was studied. The release of drug, carried out at different pH and temperatures. Finally, chemical composition, magnetic properties and morphology of doxorubicin-loaded magnetic hydrogel nanocomposites were analyzed by FT- IR, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM). The results indicated that drug loading efficiency was increased by increasing the drug ratio to polymer. Doxorubicin was released more at 40 °C and in acidic pH compared to that 37 °C and basic pH. This study suggested that the poly (NIPAAm-MAA-VP) magnetic hydrogel nanocomposite could be an effective carrier for targeting drug delivery systems of anti-cancer drugs due to its temperature sensitive properties.

  12. The Microwave Spectrum of Methyl Vinyl Ketone Revisited

    NASA Astrophysics Data System (ADS)

    Wilcox, David S.; Shirar, Amanda J.; Williams, Owen L.; Dian, Brian C.

    2011-06-01

    A chirped-pulse Fourier transform microwave spectrometer was used to record the rotational spectrum of methyl vinyl ketone (MVK, 3-butene-2-one) from 6 to 18.9 GHz. Two stable conformations were identified: the previously documented antiperiplanar (ap) conformer and synperiplanar (sp), which is reported for the first time in this microwave study. Methyl torsional analysis with XIAM resulted in V3 barrier heights of 433.8(1) and 376.6(2) Cm-1 for ap- and sp-MVK, respectively. Heavy atom isotopic species were detected in natural abundance allowing bond lengths and angles of the molecular frames to be calculated through Kraitchman analysis. A comparison with ab initio calculations is included.

  13. Left Gastric Artery Aneurysm: Successful Embolization with Ethylene Vinyl Alcohol Copolymer (Onyx)

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

    Vargas, Hebert Alberto, E-mail: alberto.vargas@addenbrookes.nhs.uk; Cousins, Claire; Higgins, J. Nicholas

    2008-03-15

    Patients with left gastric artery aneurysms present with hemorrhagic shock due to rupture or occasionally it is an incidental finding on abdominal CT examinations. Due to the increased morbidity and mortality from this condition, adequate diagnosis and treatment are essential. In this article we present a patient with a left gastric artery aneurysm treated with a new embolization agent, ethylene vinyl alcohol copolymer (Onyx)

  14. Tissue engineered poly(caprolactone)-chitosan-poly(vinyl alcohol) nanofibrous scaffolds for burn and cutting wound healing.

    PubMed

    Gholipour-Kanani, Adeleh; Bahrami, S Hajir; Joghataie, Mohammad Taghi; Samadikuchaksaraei, Ali; Ahmadi-Taftie, Hossein; Rabbani, Shahram; Kororian, Alireza; Erfani, Elham

    2014-06-01

    Natural-synthetic blend nanofibres have recently attracted more interest because of the ability of achieving desirable properties. Poly(ε-caprolactone) (PCL)-chitosan (Cs)-poly(vinyl alcohol) (PVA) blend nanofibrous scaffolds were electrospun in 2:1:1.33 mass ratio of PCL:Cs:PVA. The presence of PCL in the blend leads to improvement in web hydrophobicity and helped the web to retain its integrity in aqueous media. The scaffolds were used in two forms of acellular and with mesenchymal stem cells. They were applied on burn (n = 12) and excisional cutting (n = 12) wounds on dorsum skin of rats. Macroscopic investigations were carried out to measure the wounds areas. It was found that the area of wounds that were treated with cell-seeded nanofibrous scaffolds were smaller compared to other samples. Pathological results showed much better healing performance for cell-seeded scaffolds followed by acellular scaffolds compared with control samples. All these results indicate that PCL:Cs:PVA nanofibrous web would be a proper material for burn and cutting wound healing.

  15. Site-Specific Mobilization of Vinyl Chloride Respiration Islands by a Mechanism Common in Dehalococcoides

    PubMed Central

    2011-01-01

    Background Vinyl chloride is a widespread groundwater pollutant and Group 1 carcinogen. A previous comparative genomic analysis revealed that the vinyl chloride reductase operon, vcrABC, of Dehalococcoides sp. strain VS is embedded in a horizontally-acquired genomic island that integrated at the single-copy tmRNA gene, ssrA. Results We targeted conserved positions in available genomic islands to amplify and sequence four additional vcrABC -containing genomic islands from previously-unsequenced vinyl chloride respiring Dehalococcoides enrichments. We identified a total of 31 ssrA-specific genomic islands from Dehalococcoides genomic data, accounting for 47 reductive dehalogenase homologous genes and many other non-core genes. Sixteen of these genomic islands contain a syntenic module of integration-associated genes located adjacent to the predicted site of integration, and among these islands, eight contain vcrABC as genetic 'cargo'. These eight vcrABC -containing genomic islands are syntenic across their ~12 kbp length, but have two phylogenetically discordant segments that unambiguously differentiate the integration module from the vcrABC cargo. Using available Dehalococcoides phylogenomic data we estimate that these ssrA-specific genomic islands are at least as old as the Dehalococcoides group itself, which in turn is much older than human civilization. Conclusions The vcrABC -containing genomic islands are a recently-acquired subset of a diverse collection of ssrA-specific mobile elements that are a major contributor to strain-level diversity in Dehalococcoides, and may have been throughout its evolution. The high similarity between vcrABC sequences is quantitatively consistent with recent horizontal acquisition driven by ~100 years of industrial pollution with chlorinated ethenes. PMID:21635780

  16. Production of vinyl derivatives from alkaline hydrolysates of corn cobs by recombinant Escherichia coli containing the phenolic acid decarboxylase from Lactobacillus plantarum CECT 748T.

    PubMed

    Salgado, José Manuel; Rodríguez-Solana, Raquel; Curiel, José Antonio; de las Rivas, Blanca; Muñoz, Rosario; Domínguez, José Manuel

    2012-08-01

    The enzyme PAD from Lactobacillus plantarum CECT 748T decarboxylates some cinnamic acids namely p-coumaric acid (p-CA), caffeic acid (CA), and ferulic acid (FA) into their corresponding 4-vinyl derivatives (4-VD): 4-vinyl phenol (4-VP), 4-vinyl catechol (4-VC), and 4-vinyl guaiacol (4-VG), respectively, which are valuable food additives mainly employed as flavouring agents. The gene encoding this enzyme was cloned and overexpressed in Escherichia coli. Recombinant E. coli cells overproducing L. plantarum PAD showed a preference to degrade mainly p-CA and CA. Sterilized liquors obtained after alkaline hydrolysis of corn cob or alkaline hydrolysis of the solid residue coming from acid hydrolysis of corn cob were employed as growth media in fermentations performed in shaker or bioreactor. The fermentative process allowed converting 2222.8 mg/L p-CA into 993.9 mg/L 4-VP. The process described here allowed the production with a high-yield of a valuable food additive from a by-product of the food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Effect of Postnatal HIV Treatment on Clinical Mastitis and Breast Inflammation in HIV-Infected Breast-feeding Women.

    PubMed

    Zadrozny, Sabrina; Westreich, Daniel; Hudgens, Michael G; Chasela, Charles; Jamieson, Denise J; Martinson, Francis; Zimba, Chifundo; Tegha, Gerald; Hoffman, Irving; Miller, William C; Pence, Brian W; King, Caroline C; Kourtis, Athena P; Msungama, Wezi; van der Horst, Charles

    2017-03-01

    The relationship between mastitis and antiretroviral therapy among HIV-positive, breast-feeding women is unclear. In the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study, conducted in Lilongwe, Malawi, 2369 mother-infant pairs were randomized to a nutritional supplement group and to one of three treatment groups: maternal antiretroviral therapy (ART), infant nevirapine (NVP) or standard of care for 24 weeks of exclusive breast-feeding and 4 weeks of weaning. Among 1472 HIV-infected women who delivered live infants between 2004 and 2007, we estimated cumulative incidence functions and sub-distribution hazard ratios (HR) of mastitis or breast inflammation comparing women in maternal ART (n = 487) or infant nevirapine (n = 492) groups to the standard of care (n = 493). Nutritional supplement groups (743 took, 729 did not) were also compared. Through 28-weeks post-partum, 102 of 1472 women experienced at least one occurrence of mastitis or breast inflammation. The 28-week risk was higher for maternal ART (risk difference (RD) 4.5, 95% confidence interval (CI) 0.9, 8.1) and infant NVP (RD 3.6, 95% CI 0.3, 6.9) compared to standard of care. The hazard of late-appearing mastitis or breast inflammation (from week 5-28) was also higher for maternal ART (HR 6.7, 95% CI 2.0, 22.6) and infant NVP (HR 5.1, 95% CI 1.5, 17. 5) compared to the standard of care. Mastitis or breast inflammation while breast-feeding is a possible side effect for women taking prophylactic ART and women whose infants take NVP, warranting additional research in the context of postnatal HIV transmission. © 2017 John Wiley & Sons Ltd.

  18. Heat shock protein 90 inhibitor NVP-AUY922 exerts potent activity against adult T-cell leukemia-lymphoma cells.

    PubMed

    Taniguchi, Hiroaki; Hasegawa, Hiroo; Sasaki, Daisuke; Ando, Koji; Sawayama, Yasushi; Imanishi, Daisuke; Taguchi, Jun; Imaizumi, Yoshitaka; Hata, Tomoko; Tsukasaki, Kunihiro; Uno, Naoki; Morinaga, Yoshitomo; Yanagihara, Katsunori; Miyazaki, Yasushi

    2014-12-01

    Adult T-cell leukemia-lymphoma (ATL), an aggressive neoplasm etiologically associated with HTLV-1, is a chemoresistant malignancy. Heat shock protein 90 (HSP90) is involved in folding and functions as a chaperone for multiple client proteins, many of which are important in tumorigenesis. In this study, we examined NVP-AUY922 (AUY922), a second generation isoxazole-based non-geldanamycin HSP90 inhibitor, and confirmed its effects on survival of ATL-related cell lines. Analysis using FACS revealed that AUY922 induced cell-cycle arrest and apoptosis; it also inhibited the growth of primary ATL cells, but not of normal PBMCs. AUY922 caused strong upregulation of HSP70, a surrogate marker of HSP90 inhibition, and a dose-dependent decrease in HSP90 client proteins associated with cell survival, proliferation, and cell cycle in the G1 phase, including phospho-Akt, Akt, IKKα, IKKβ, IKKγ, Cdk4, Cdk6, and survivin. Interestingly, AUY922 induced downregulation of the proviral integration site for Moloney murine leukemia virus (PIM) in ATL cells. The PIM family (PIM-1, -2, -3) is made up of oncogenes that encode a serine/threonine protein kinase family. As PIM kinases have multiple functions involved in cell proliferation, survival, differentiation, apoptosis, and tumorigenesis, their downregulation could play an important role in AUY922-induced death of ATL cells. In fact, SGI-1776, a pan-PIM kinase inhibitor, successfully inhibited the growth of primary ATL cells as well as ATL-related cell lines. Our findings suggest that AUY922 is an effective therapeutic agent for ATL, and PIM kinases may be a novel therapeutic target. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  19. Volatile out gassing characteristics of highly filled ethylene vinyl acetate binder materials: Gas phase infra-red spectroscopy

    DOE PAGES

    Patel, Mogon; Bowditch, Martin; Jones, Ben; ...

    2012-12-08

    Gas phase Infra-red (IR) spectroscopy has been used to investigate volatile out gassing properties of highly filled poly (ethylene-co-vinyl acetate) materials. In these studies, a Scout-EN TM heated gas cell was interfaced to a vacuum FTIR spectrometer, and the quantification of evolved species was achieved through calibration of the gas cell with certified gas standards. The volatile out gassing properties were monitored as a function of time during storage at 75°C under vacuum conditions (< 1mbar). Acetic acid, carbon dioxide and water were identified as the major out gassing products through IR absorption peaks at 1797, 2354 and 3853 cmmore » -1, respectively. We present a comparison of three highly filled poly (ethyleneco- vinyl acetate) resins.« less

  20. Adverse pregnancy outcomes in women with nausea and vomiting of pregnancy.

    PubMed

    Temming, Lorene; Franco, Albert; Istwan, Niki; Rhea, Debbie; Desch, Cheryl; Stanziano, Gary; Joy, Saju

    2014-01-01

    To examine the influence of nausea and vomiting of pregnancy (NVP) on pregnancy outcomes. Outcomes were compared for primigravidas with a current singleton gestation enrolled at <20 weeks' gestation in a maternity risk screening and education program (n = 81 486). Patient-reported maternal characteristics and pregnancy outcomes were compared for women with and without NVP and within the NVP group for those with and without poor weight gain. 6.4% of women reported NVP as a pregnancy complication. Women reporting NVP were more likely to be younger, obese, single and smoke. They had higher rates of preterm delivery, pregnancy-induced hypertension and low birth weight <2500 g. Almost one-quarter of women with NVP had lower than recommended weight gain. Poor weight gain was associated with a higher incidence of adverse outcomes. Obesity, tobacco use and poor pregnancy weight gain independently increased the odds of an adverse outcome. NVP and subsequent poor weight gain may be associated with adverse pregnancy outcomes.