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Sample records for butanediols

  1. 1,3-Butanediol Dibenzoate

    Directory of Open Access Journals (Sweden)

    Wataru Hakamata

    2016-08-01

    Full Text Available Environmentally friendly and straightforward methods for creating biofuels are required to promote biofuel use. Therefore, we present here a convenient and environmentally friendly direct self-aldol reaction of acetaldehyde in 100 mM borate buffer (pH 10 affording the dimer of 3-hydroxybutanal with a good yield. The product can be easily converted into 1,3-butanediol and its benzoate; therefore, our results will have a positive impact in the field of biochemical production from ethanol.

  2. Engineering of Bacillus subtilis for the Production of 2,3-Butanediol from Sugarcane Molasses.

    Science.gov (United States)

    Deshmukh, Apoorva Nandkumar; Nipanikar-Gokhale, Padmaja; Jain, Rishi

    2016-05-01

    2,3-butanediol is known to be a platform chemical with several potential industrial applications. Sustainable industrial scale production can be attained by using a sugarcane molasses based fermentation process using Bacillus subtilis. However, the accumulation of acetoin needs to be reduced to improve process efficiency. In this work, B. subtilis was genetically modified in order to increase the yield of 2,3-butanediol. Metabolic engineering strategies such as cofactor engineering and overexpression of the key enzyme butanediol dehydrogenase were attempted. Both the strategies individually led to a statistically significant increase in the 2,3-butanediol yields for sugarcane molasses based fermentation. Cofactor engineering led to a 26 % increase in 2,3-butanediol yield and overexpression of bdhA led to a 11 % increase. However, the combination of the two strategies did not lead to a synergistic increase in 2,3-butanediol yield. PMID:26825987

  3. Conversion of 2,3-butanediol to butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, Michael A.; Frye, Jr, John G.; Lee, Suh-Jane; Albrecht, Karl O.

    2016-09-06

    A composition comprising 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by exposure to a catalyst comprising (a) M.sub.xO.sub.y wherein M is a rare earth metal, a group IIIA metal, Zr, or a combination thereof, and x and y are based upon an oxidation state of M, or (b) M.sup.3.sub.a(PO.sub.4).sub.b where M.sup.3 is a group IA, a group IIA metal, a group IIIA metal, or a combination thereof, and a and b are based upon the oxidation state of M.sup.3. Embodiments of the catalyst comprising M.sub.xO.sub.y may further include M.sup.2, wherein M.sup.2 is a rare earth metal, a group IIA metal, Zr, Al, or a combination thereof. In some embodiments, 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by a catalyst comprising M.sub.xO.sub.y, and the methyl vinyl carbinol is subsequently dehydrated to 1,3-butadiene by exposure to a solid acid catalyst.

  4. Engineered Serratia marcescens for efficient (3R)-acetoin and (2R,3R)-2,3-butanediol production.

    Science.gov (United States)

    Bai, Fangmin; Dai, Lu; Fan, Jiying; Truong, Ngoctu; Rao, Ben; Zhang, Liaoyuan; Shen, Yaling

    2015-05-01

    (3R)-Acetoin and (2R,3R)-2,3-butanediol are important pharmaceutical intermediates. However, until now, the quantity of natural microorganisms with the ability to produce single configuration of optically pure (3R)-acetoin and (2R,3R)-2,3-butanediol is rare. In this study, a meso-2,3-butanediol dehydrogenase encoded by the slaC gene from Serratia marcescens MG1 was identified for meso-2,3-butanediol and (2S,3S)-2,3-butanediol biosynthesis. Inactivation of the slaC gene could significantly decrease meso-2,3-butanediol and (2S,3S)-2,3-butanediol and result in a large quantity of (3R)-acetoin accumulation. Furthermore, a (2R,3R)-2,3-butanediol dehydrogenase encoded by the bdhA gene from Bacillus subtilis 168 was introduced into the slaC mutant strain of Serratia marcescens MG1. Excess (2R,3R)-2,3-butanediol dehydrogenase could accelerate the reaction from (3R)-acetoin to (2R,3R)-2,3-butanediol and lead to (2R,3R)-2,3-butanediol accumulation. In fed-batch fermentation, the excess (2R,3R)-2,3-butanediol dehydrogenase expression strain could produce 89.81 g/l (2R,3R)-2,3-butanediol with a productivity of 1.91 g/l/h at 48 h. These results provided potential applications for (3R)-acetoin and (2R,3R)-2,3-butanediol production.

  5. Impact of a Bacterial Volatile 2,3-Butanediol on Bacillus subtilis Rhizosphere Robustness

    Science.gov (United States)

    Yi, Hwe-Su; Ahn, Yeo-Rim; Song, Geun C.; Ghim, Sa-Youl; Lee, Soohyun; Lee, Gahyung; Ryu, Choong-Min

    2016-01-01

    Volatile compounds, such as short chain alcohols, acetoin, and 2,3-butanediol, produced by certain strains of root-associated bacteria (rhizobacteria) elicit induced systemic resistance in plants. The effects of bacterial volatile compounds (BVCs) on plant and fungal growth have been extensively studied; however, the impact of bacterial BVCs on bacterial growth remains poorly understood. In this study the effects of a well-characterized bacterial volatile, 2,3-butanediol, produced by the rhizobacterium Bacillus subtilis, were examined in the rhizosphere. The nature of 2,3-butanediol on bacterial cells was assessed, and the effect of the molecule on root colonization was also determined. Pepper roots were inoculated with three B. subtilis strains: the wild type, a 2,3-butanediol overexpressor, and a 2,3-butanediol null mutant. The B. subtilis null strain was the first to be eliminated in the rhizosphere, followed by the wild-type strain. The overexpressor mutant was maintained at roots for the duration of the experiment. Rhizosphere colonization by a saprophytic fungus declined from 14 days post-inoculation in roots treated with the B. subtilis overexpressor strain. Next, exudates from roots exposed to 2,3-butanediol were assessed for their impact on fungal and bacterial growth in vitro. Exudates from plant roots pre-treated with the 2,3-butanediol overexpressor were used to challenge various microorganisms. Growth was inhibited in a saprophytic fungus (Trichoderma sp.), the 2,3-butanediol null B. subtilis strain, and a soil-borne pathogen, Ralstonia solanacearum. Direct application of 2,3-butanediol to pepper roots, followed by exposure to R. solanacearum, induced expression of Pathogenesis-Related (PR) genes such as CaPR2, CaSAR8.2, and CaPAL. These results indicate that 2,3-butanediol triggers the secretion of root exudates that modulate soil fungi and rhizosphere bacteria. These data broaden our knowledge regarding bacterial volatiles in the rhizosphere and

  6. Biological denitrification using poly(butanediol succinate) as electron donor.

    Science.gov (United States)

    Shen, Zhiqiang; Yin, Yanan; Wang, Jianlong

    2016-07-01

    Poly(butanediol succinate) (PBS), a biodegradable polymer, was used as both solid carbon source and biofilm carrier for biological nitrate removal process, in which PBS was filled in a packed-bed bioreactor. The denitrification performance and the microbial diversity of biofilm attached on the surface of PBS were investigated. The experimental results showed that the volumetric denitrification rate was 0.60 kg m(-3) day(-1) when NO3-N loading rate was 0.63 kg m(-3) day(-1), and the average NO2-N concentration was below 0.20 mg L(-1). The effluent pH value decreased slightly from a range of 6.98-7.87 to 6.46-7.18. The analysis of microbial community structure of biofilm by pyrosequencing method showed that Proteobacteria was the most abundant phylum (89.87 %), and β-Proteobacteria represented the most abundant class. Among the 76 identified genera, Dechloromonas (10.26 %), Alicycliphilus (9.15 %), Azospira (8.92 %), and Sinobacteraceae-uncultured (8.75 %) were the abundant genera. PBS, as a promising alternative carbon source, is a suitable solid carbon source and biofilm carrier for nitrate removal. PMID:26960320

  7. Combined enzymatic hydrolysis and fermentation of hemicellulose to 2,3-butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Yu, E.K.C.; Deschatelets, L.; Saddler, J.N.

    1984-06-01

    Hemicellulose-rich fractions from several agricultural residues were converted to 2,3-butanediol by a combined enzymatic hydrolysis and fermentation process. Culture filtrates from Trichoderma harzianum E58 were used to hydrolyze the substrates while Klebsiella pneumoniae fermented the liberated sugars to 2,3-butanediol. Approximately 50-60% of a 5% (w/v) xylan preparation could be hydrolyzed and quantitatively converted to 2,3-butanediol using this procedure. Although enzymatic hydrolysis was optimal at pH 5.0 and 50/sup 0/C, the combined hydrolysis and fermentation was most efficient at pH 6.5 and 30/sup 0/C. Combined hydrolysis and fermentation resulted in butanediol levels that were 20-40% higher than could be obtained with a separate hydrolysis and fermentation process. The hemicellulose-rich water-soluble fractions obtained from a variety of steam-exploded agricultural residues could be readily used by the combined hydrolysis and fermentation approach resulting in butanediol yields of 0.4-0.5 g/g of reducing sugar utilized.

  8. Enhancement of 2,3-Butanediol Production by Klebsiella oxytoca PTCC 1402

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    Maesomeh Anvari

    2011-01-01

    Full Text Available Optimal operating parameters of 2,3-Butanediol production using Klebsiella oxytoca under submerged culture conditions are determined by using Taguchi method. The effect of different factors including medium composition, pH, temperature, mixing intensity, and inoculum size on 2,3-butanediol production was analyzed using the Taguchi method in three levels. Based on these analyses the optimum concentrations of glucose, acetic acid, and succinic acid were found to be 6, 0.5, and 1.0 (% w/v, respectively. Furthermore, optimum values for temperature, inoculum size, pH, and the shaking speed were determined as 37°C, 8 (g/L, 6.1, and 150 rpm, respectively. The optimal combinations of factors obtained from the proposed DOE methodology was further validated by conducting fermentation experiments and the obtained results revealed an enhanced 2,3-Butanediol yield of 44%.

  9. Butanediol production from cellulose and hemicellulose by Klebsiella pneumoniae grown in sequential coculture with Trichoderma harzianum

    Energy Technology Data Exchange (ETDEWEB)

    Yu, E.K.C.; Deschatelets, L.; Louis-Seize, G.; Saddler, J.N.

    1985-10-01

    The bioconverison of cellulose and hemicellulose substrates to 2,3-butanediol by a sequential coculture approach was investigated with the cellulolytic fungus Trichoderma harzianum E58 and the fermentative bacterium Klebsiella pneumoniae. Vogel medium optimal for the production of the cellulolytic and xylanolytic enzymes of the fungus was found to be inhibitory to butanediol fermentation. This inhibition appeared to be due to a synergistic effect of various ingredients, particularly the salts, present in the fungal medium. The removal or replacement of such ingredients from Vogel medium led to the relief of fermentation inhibition, but the treatments also resulted in a significant decrease in fungal enzyme production. Resting cells of K. pneumoniae could be used for butanediol production in the fungal medium, indicating that the inhibitory effect on solvent production under such conditions was due to the indirect result of growing inhibition of the bacterial cells. The resting-cell approach could be combined with a fed-batch system for the direct conversion of 8 to 10% (wt/vol) of Solka-Floc or aspenwood xylan to butanediol at over 30% of the theoretical conversion efficiencies.

  10. Cloning, expression and characterization of glycerol dehydrogenase involved in 2,3-butanediol formation in Serratia marcescens H30.

    Science.gov (United States)

    Zhang, Liaoyuan; Xu, Quanming; Peng, Xiaoqian; Xu, Boheng; Wu, Yuehao; Yang, Yulong; Sun, Shujing; Hu, Kaihui; Shen, Yaling

    2014-09-01

    The meso-2,3-butanediol dehydrogenase (meso-BDH) from S. marcescens H30 is responsible for converting acetoin into 2,3-butanediol during sugar fermentation. Inactivation of the meso-BDH encoded by budC gene does not completely abolish 2,3-butanediol production, which suggests that another similar enzyme involved in 2,3-butanediol formation exists in S. marcescens H30. In the present study, a glycerol dehydrogenase (GDH) encoded by gldA gene from S. marcescens H30 was expressed in Escherichia coli BL21(DE3), purified and characterized for its properties. In vitro conversion indicated that the purified GDH could catalyze the interconversion of (3S)-acetoin/meso-2,3-butanediol and (3R)-acetoin/(2R,3R)-2,3-butanediol. (2S,3S)-2,3-Butanediol was not a substrate for the GDH at all. Kinetic parameters of the GDH enzyme showed lower K m value and higher catalytic efficiency for (3S/3R)-acetoin in comparison to those for (2R,3R)-2,3-butanediol and meso-2,3-butanediol, implying its physiological role in favor of 2,3-butanediol formation. Maximum activity for reduction of (3S/3R)-acetoin and oxidations of meso-2,3-butanediol and glycerol was observed at pH 8.0, while it was pH 7.0 for diacetyl reduction. The enzyme exhibited relative high thermotolerance with optimum temperature of 60 °C in the oxidation-reduction reactions. Over 60 % of maximum activity was retained at 70 °C. Additionally, the GDH activity was significantly enhanced for meso-2,3-BD oxidation in the presence of Fe(2+) and for (3S/3R)-acetoin reduction in the presence of Mn(2+), while several cations inhibited its activity, particularly Fe(2+) and Fe(3+) for (3S/3R)-acetoin reduction. The properties provided potential application for single configuration production of acetoin and 2,3-butanediol .

  11. Enantioselective Synthesis of Vicinal (R,R)-Diols by Saccharomyces cerevisiae Butanediol Dehydrogenase.

    Science.gov (United States)

    Calam, Eduard; González-Roca, Eva; Fernández, M Rosario; Dequin, Sylvie; Parés, Xavier; Virgili, Albert; Biosca, Josep A

    2016-03-01

    Butanediol dehydrogenase (Bdh1p) from Saccharomyces cerevisiae belongs to the superfamily of the medium-chain dehydrogenases and reductases and converts reversibly R-acetoin and S-acetoin to (2R,3R)-2,3-butanediol and meso-2,3-butanediol, respectively. It is specific for NAD(H) as a coenzyme, and it is the main enzyme involved in the last metabolic step leading to (2R,3R)-2,3-butanediol in yeast. In this study, we have used the activity of Bdh1p in different forms-purified enzyme, yeast extracts, permeabilized yeast cells, and as a fusion protein (with yeast formate dehydrogenase, Fdh1p)-to transform several vicinal diketones to the corresponding diols. We have also developed a new variant of the delitto perfetto methodology to place BDH1 under the control of the GAL1 promoter, resulting in a yeast strain that overexpresses butanediol dehydrogenase and formate dehydrogenase activities in the presence of galactose and regenerates NADH in the presence of formate. While the use of purified Bdh1p allows the synthesis of enantiopure (2R,3R)-2,3-butanediol, (2R,3R)-2,3-pentanediol, (2R,3R)-2,3-hexanediol, and (3R,4R)-3,4-hexanediol, the use of the engineered strain (as an extract or as permeabilized cells) yields mixtures of the diols. The production of pure diol stereoisomers has also been achieved by means of a chimeric fusion protein combining Fdh1p and Bdh1p. Finally, we have determined the selectivity of Bdh1p toward the oxidation/reduction of the hydroxyl/ketone groups from (2R,3R)-2,3-pentanediol/2,3-pentanedione and (2R,3R)-2,3-hexanediol/2,3-hexanedione. In conclusion, Bdh1p is an enzyme with biotechnological interest that can be used to synthesize chiral building blocks. A scheme of the favored pathway with the corresponding intermediates is proposed for the Bdh1p reaction.

  12. THE SOLUBILITY OF LIGNIN FROM BAGASSE IN A 1,4-BUTANEDIOL/WATER SYSTEM

    OpenAIRE

    Qiang Wang; Kefu Chen; Jun Li; Guihua Yang,; Shanshan Liu; Jun Xu

    2011-01-01

    The solubility of lignin from bagasse in a 1,4-butanediol/water mixed solution was investigated and explained by the solubility parameter (δ-value). To explore the lignin solubility, enzymatic hydrolysis/mild acidolysis lignin (EMAL) isolated from bagasse was used as the starting material to prepare lignin solution by ultrasonic treatment. The lignin content in solution was determined by UV-vis spectroscopy at a wavelength of 280 nm. The results showed that 240 minutes of ultrasonic treatment...

  13. Salting-out Extraction of 2,3-Butanediol from Jerusalem artichoke-based Fermentation Broth

    Institute of Scientific and Technical Information of China (English)

    DAI Jianying; ZHANG Yuanli; XIU Zhilong

    2011-01-01

    The removal of solid impurities and separation of target products from a fermentation broth is becoming more tedious with the utilization of lignocelluloses as source of substrate.2,3-Butanediol,an important chemical used widely is also a main product of sugar-based fermentation carried out by Klebsiella pneumoniae.In this study,we investigated the use of salting-out extraction(SOE) that employed a K2HPO4/ethanol system consisting of 21% ethanol and 17% K2HPO4(mass fraction) to separate 2,3-butanediol from the viscous Jerusalem artichoke-based fermentation broth.After SOE,about 98% of solid matters was removed,and the viscosity decreased from 72.5 mPa s in the original fermentation broth to 4.4 mPa s in the top phase.The partition coefficient and yield of 2,3-butanediol reached 13.4 and 99%,respectively,and 89% of soluble proteins was removed from the broth.The results showed that SOE is an efficient way for isolating 2,3-BD from a highly viscous fermentation broth by removing much of the solid matters within the broth.

  14. Thermophilic fermentation of acetoin and 2,3-butanediol by a novel Geobacillus strain

    Directory of Open Access Journals (Sweden)

    Xiao Zijun

    2012-12-01

    Full Text Available Abstract Background Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination. Results This work reports the isolation and identification of a novel aerobic Geobacillus strain XT15 capable of producing both of these chemicals under elevated temperatures, thus reducing the risk of bacterial contamination. The optimum growth temperature was found to be between 45 and 55°C and the medium initial pH to be 8.0. In addition to glucose, galactose, mannitol, arabionose, and xylose were all acceptable substrates, enabling the potential use of cellulosic biomass as the feedstock. XT15 preferred organic nitrogen sources including corn steep liquor powder, a cheap by-product from corn wet-milling. At 55°C, 7.7 g/L of acetoin and 14.5 g/L of 2,3-butanediol could be obtained using corn steep liquor powder as a nitrogen source. Thirteen volatile products from the cultivation broth of XT15 were identified by gas chromatography–mass spectrometry. Acetoin, 2,3-butanediol, and their derivatives including a novel metabolite 2,3-dihydroxy-3-methylheptan-4-one, accounted for a total of about 96% of all the volatile products. In contrast, organic acids and other products were minor by-products. α-Acetolactate decarboxylase and acetoin:2,6-dichlorophenolindophenol oxidoreductase in XT15, the two key enzymes in acetoin metabolic pathway, were found to be both moderately thermophilic with the identical optimum temperature of 45°C. Conclusions Geobacillus sp. XT15 is the first naturally occurring thermophile excreting acetoin and/or 2,3-butanediol. This work has demonstrated the attractive prospect of developing it as an industrial strain in the thermophilic fermentation of acetoin and 2,3-butanediol with improved anti-contamination performance. The novel metabolites and enzymes identified in XT15 also indicated its

  15. Novel microbial screen for detection of 1,4-butanediol, ethylene glycol, and adipic acid.

    Science.gov (United States)

    Stieglitz, B; Weimer, P J

    1985-03-01

    A novel microbial-screening procedure was developed for separate detection of 1,4-butanediol, ethylene glycol, and adipic acid, three commercially important oxychemicals potentially derivable from bacterial omega-oxidation of n-butanol, ethanol, and hexanoic acid, respectively. The screening method involved postproduction addition of one of several specific Pseudomonas strains which produce a soluble fluorescent pigment during growth on the product of interest. A mutation and selection procedure was developed for isolation of specific strains with phenotypes for growth and pigment production on the desired product (e.g., 1,4-butanediol), but not on its bioconversion substrate (e.g., n-butanol), common by-products (e.g., n-butyrate), or product isomers. Pigment production was growth associated and required cultivation of the screening strains under limiting Fe3+ concentrations. The pigments resembled well-characterized, iron-chelating siderophores produced by other fluorescent pseudomonads. The sensitivity of the assay for product accumulation was enhanced by (i) conducting the screening in microtiter dishes to permit examination of individual isolates of putative producers and to control product diffusion, (ii) using a wavelength cutoff filter to reduce background source light, and (iii) using adapted screening strains which grew at lower (0.3 mM) concentrations of test compounds. The potential utility of the method for detecting a variety of oxidative catabolic products is discussed.

  16. Linear and cyclic ester Oligomers of succinic acid and 1,4-butanediol: Biocatalytic synthesis and characterization

    NARCIS (Netherlands)

    Habeych Narvaez, D.I.; Eggink, G.; Boeriu, C.G.

    2011-01-01

    The lipase-catalyzed synthesis of cyclic ester oligomers from non-activated succinic acid (A) and 1,4-butanediol (B) in the presence of immobilized Candida antarctica lipase B was investigated. Batch and pulse fed-batch systems were implemented to increase the formation of cyclic ester products. The

  17. Renewable Gasoline, Solvents, and Fuel Additives from 2,3-Butanediol.

    Science.gov (United States)

    Harvey, Benjamin G; Merriman, Walter W; Quintana, Roxanne L

    2016-07-21

    2,3-Butanediol (2,3-BD) is a renewable alcohol that can be prepared in high yield from biomass sugars. 2,3-BD was selectively dehydrated in a solvent-free process to a complex mixture of 2-ethyl-2,4,5-trimethyl-1,3-dioxolanes and 4,5-dimethyl-2isopropyl dioxolanes with the heterogeneous acid catalyst Amberlyst-15. The purified dioxolane mixture exhibited an anti-knock index of 90.5, comparable to high octane gasoline, and a volumetric net heat of combustion 34 % higher than ethanol. The solubility of the dioxolane mixture in water was only 0.8 g per 100 mL, nearly an order of magnitude lower than the common gasoline oxygenate methyl tert-butyl ether. The dioxolane mixture has potential applications as a sustainable gasoline blending component, diesel oxygenate, and industrial solvent. PMID:27304610

  18. Renewable Gasoline, Solvents, and Fuel Additives from 2,3-Butanediol.

    Science.gov (United States)

    Harvey, Benjamin G; Merriman, Walter W; Quintana, Roxanne L

    2016-07-21

    2,3-Butanediol (2,3-BD) is a renewable alcohol that can be prepared in high yield from biomass sugars. 2,3-BD was selectively dehydrated in a solvent-free process to a complex mixture of 2-ethyl-2,4,5-trimethyl-1,3-dioxolanes and 4,5-dimethyl-2isopropyl dioxolanes with the heterogeneous acid catalyst Amberlyst-15. The purified dioxolane mixture exhibited an anti-knock index of 90.5, comparable to high octane gasoline, and a volumetric net heat of combustion 34 % higher than ethanol. The solubility of the dioxolane mixture in water was only 0.8 g per 100 mL, nearly an order of magnitude lower than the common gasoline oxygenate methyl tert-butyl ether. The dioxolane mixture has potential applications as a sustainable gasoline blending component, diesel oxygenate, and industrial solvent.

  19. Metabolic Engineering of Zymomonas mobilis for 2,3-Butanediol Production from Lignocellulosic Biomass Sugars

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shihui; Mohagheghi, Ali; Franden, Mary Ann; Chou, Yat-Chen; Chen, Xiaowen; Dowe, Nancy; Himmel, Michael E.; Zhang, Min

    2016-09-02

    To develop pathways for advanced biofuel production, and to understand the impact of host metabolism and environmental conditions on heterologous pathway engineering for economic advanced biofuels production from biomass, we seek to redirect the carbon flow of the model ethanologen Zymomonas mobilis to produce desirable hydrocarbon intermediate 2,3-butanediol (2,3-BDO). 2,3-BDO is a bulk chemical building block, and can be upgraded in high yields to gasoline, diesel, and jet fuel. 2,3-BDO biosynthesis pathways from various bacterial species were examined, which include three genes encoding acetolactate synthase, acetolactate decarboxylase, and butanediol dehydrogenase. Bioinformatics analysis was carried out to pinpoint potential bottlenecks for high 2,3-BDO production. Different combinations of 2,3-BDO biosynthesis metabolic pathways using genes from different bacterial species have been constructed. Our results demonstrated that carbon flux can be deviated from ethanol production into 2,3-BDO biosynthesis, and all three heterologous genes are essential to efficiently redirect pyruvate from ethanol production for high 2,3-BDO production in Z. mobilis. The down-selection of best gene combinations up to now enabled Z. mobilis to reach the 2,3-BDO production of more than 10 g/L from glucose and xylose, as well as mixed C6/C5 sugar streams derived from the deacetylation and mechanical refining process. This study confirms the value of integrating bioinformatics analysis and systems biology data during metabolic engineering endeavors, provides guidance for value-added chemical production in Z. mobilis, and reveals the interactions between host metabolism, oxygen levels, and a heterologous 2,3-BDO biosynthesis pathway. Taken together, this work provides guidance for future metabolic engineering efforts aimed at boosting 2,3-BDO titer anaerobically.

  20. Epoxidation and oxidation reactions using 1,4-butanediol dimethacrylate crosslinked polystyrene-supported tertiary butyl hydroperoxide

    Indian Academy of Sciences (India)

    M S Sheela; K Sreekumar

    2004-11-01

    1,4-Butanediol dimethacrylate (1,4-BDDMA) crosslinked polystyrene-supported -butyl hydroperoxide was employed in the epoxidation of olefins and oxidation of alcohols to carbonyl compounds. The reagent proved to be successful as a recyclable solid phase organic reagent with as much or more efficiency when compared to its monomeric counterpart. The extent of reaction was found to be dependent on various reaction parameters like solvent, temperature, molar concentration and presence of catalyst.

  1. Enhanced fed-batch fermentation of 2,3-butanediol by Paenibacillus polymyxa DSM 365.

    Science.gov (United States)

    Häßler, Thomas; Schieder, Doris; Pfaller, Rupert; Faulstich, Martin; Sieber, Volker

    2012-11-01

    Fed-batch fermentations for the production of 2,3-butanediol (BDL) with Paenibacillus polymyxa DSM 365 were investigated in 2-L-fermenters. A suitable micro-aerobic set-up enabled high product selectivity of up to 98% R,R-BDL towards meso-BDL and acetoin. Up to 111 g L(-1)R,R-BDL within 54 h could be achieved with sufficient supply of complex medium (yeast extract). To the best of the knowledge of the authors, this is the highest titer so far reported for P. polymyxa indicating its high potential as a non pathogenic BDL-producer. Fermentation in low nutritional medium (5 g L(-1) yeast extract) yielded up to 72 g L(-1) BDL+acetoin (79% R,R-BDL), yet was affected by formation of exopolysaccharides (EPS). In the range of 30-40°C EPS formation decreased with raising temperature although growth rate and BDL-production remained similar. Additionally, Tween80® was found to be a good additive to reduce viscosity caused by EPS.

  2. Modification of chimeric (2S, 3S)-butanediol dehydrogenase based on structural information.

    Science.gov (United States)

    Shimegi, Tomohito; Mochizuki, Kaito; Oyama, Takuji; Ohtsuki, Takashi; Kusunoki, Masami; Ui, Sadaharu

    2014-01-01

    A chimeric (2S, 3S)-butanediol dehydrogenase (cLBDH) was engineered to have the strict (S)-configuration specificity of the (2S, 3S)-BDH (BsLBDH) derived from Brevibacterium saccharolyticum as well as the enzymatic stability of the (2R, 3S)-BDH (KpMBDH) from Klebsiella pneumonia by swapping the domains of two native BDHs. However, while cLBDH possesses the stability, it lacks the specificity. In order to assist in the design a BDH having strict substrate specificity, an X-ray structural analysis of a cLBDH crystal was conducted at 1.58 Å. The results obtained show some readily apparent differences around the active sites of cLBDH and BsLBDH. Based on this structural information, a novel (2S, 3S)-BDH having a preferred specificity was developed by introducing a V254L mutation into cLBDH. The influence of this mutation on the stability of cLBDH was not evaluated. Nevertheless, the technique described herein is an effective method for the production of a tailor-made BDH. PMID:25612804

  3. Biotransformation of acetoin to 2,3-butanediol: Assessment of plant and microbial biocatalysts

    Science.gov (United States)

    Javidnia, Katayoun; Faghih-Mirzaei, Ehsan; Miri, Ramin; Attarroshan, Mahshid; Zomorodian, Kamiar

    2016-01-01

    2,3-Butanediol (2,3-BD) is a valuable bulk chemical owing to its extensive application in chemical and pharmaceutical industry with diverse applications in drug, cosmetics and food products. In the present study, the biotransformation of acetoin to 2,3-BD by five plant species (Brassica oleracea, Brassica rapa, Daucuscarota, Pastinaca sativa, and Raphnussativus) and five microorganisms (Aspergillusfoetidus, Penicillumcitrinum, Saccharomyces carlbergensis, Pichiafermentans, and Rhodotrulaglutinis) was investigated as a method for the production of 2,3-BD, which can serve as an alternative to the common pentoses and hexoses fermentation by microorganisms. The produced 2,3-BD stereoisomers were characterized and their total conversion yields were determined. The results showed that the examined plants can be used as a green factory for the production of all 2,3-BD stereoisomers, except B. rapa. In microorganisms, P. fermentans and S. carlbergensis produced (–)-2R,3R and mesobutanediol, while P. citrinum produced (+)-2S,3S and mesobutanediol. R. glutinis and A. foetidus produced all three isomers. In conclusion, efficient whole-cell biocatalysts from plants and microorganisms were determined in the bioconversion of acetoin to 2,3-BD. The profile of produced stereoisomers demonstrated that microorganisms produce more specific stereoisomers.

  4. Suitability of aspenwood biologically delignified with Pheblia tremellosus for fermentation to ethanol or butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Mes-Hartree, M.; Yu, E.K.C.; Saddler, J.N.; Reid, I.D.

    1987-05-01

    Enzymatic conversion of lignocellulosic materials to fuels and chemicals depends on an initial pretreatment to render the cellulose more susceptible to enzymatic attack. Biological delignification of aspenwood with the fungus Phlebia tremellosus was compared to steaming as a pretreatment method. The biologically delignified aspenwood (BDA) had a high pentosan content and did not contain inhibitors of enzymatic hydrolysis or subsequent fermentation. In contrast, the steamed aspenwood required a water-extraction step to remove the inhibitory material and this step also removed most of the pentosan. The yield of treated material was 90% from biological delignification and 70% from steaming. The cellulose in the BDA was less accessible to the cellulase enzymes than the steamed aspenwood. Combined hydrolysis and fermentation with Saccharomyces cerevisiae gave a lower yield of ethanol from BDA than from the steamed aspenwood, but the yields based on the weight of substrate before pretreatment were comparable. Combined hydrolysis and fermentation with Klebsiella pneumoniae gave higher yields of butanediol from BDA than from steamed aspenwood, because Klebsiella can ferment the xylose which was present in the biologically treated aspenwood. Trichoderma harzianum produced lower levels of cellulase enzymes when grown on BDA than when grown on steamed aspenwood and this was related to the xylan found in the biologically treated material.

  5. Biotransformation of acetoin to 2,3-butanediol: Assessment of plant and microbial biocatalysts.

    Science.gov (United States)

    Javidnia, Katayoun; Faghih-Mirzaei, Ehsan; Miri, Ramin; Attarroshan, Mahshid; Zomorodian, Kamiar

    2016-07-01

    2,3-Butanediol (2,3-BD) is a valuable bulk chemical owing to its extensive application in chemical and pharmaceutical industry with diverse applications in drug, cosmetics and food products. In the present study, the biotransformation of acetoin to 2,3-BD by five plant species (Brassica oleracea, Brassica rapa, Daucuscarota, Pastinaca sativa, and Raphnussativus) and five microorganisms (Aspergillusfoetidus, Penicillumcitrinum, Saccharomyces carlbergensis, Pichiafermentans, and Rhodotrulaglutinis) was investigated as a method for the production of 2,3-BD, which can serve as an alternative to the common pentoses and hexoses fermentation by microorganisms. The produced 2,3-BD stereoisomers were characterized and their total conversion yields were determined. The results showed that the examined plants can be used as a green factory for the production of all 2,3-BD stereoisomers, except B. rapa. In microorganisms, P. fermentans and S. carlbergensis produced (-)-2R,3R and mesobutanediol, while P. citrinum produced (+)-2S,3S and mesobutanediol. R. glutinis and A. foetidus produced all three isomers. In conclusion, efficient whole-cell biocatalysts from plants and microorganisms were determined in the bioconversion of acetoin to 2,3-BD. The profile of produced stereoisomers demonstrated that microorganisms produce more specific stereoisomers. PMID:27651816

  6. Synthetic operon for (R,R)-2,3-butanediol production in Bacillus subtilis and Escherichia coli.

    Science.gov (United States)

    de Oliveira, Rafael R; Nicholson, Wayne L

    2016-01-01

    To reduce dependence on petroleum, an alternative route to production of the chemical feedstock 2,3-butanediol (2,3-BD) from renewable lignocellulosic sources is desirable. In this communication, the genes encoding the pathway from pyruvate to 2,3-BD (alsS, alsD, and bdhA encoding acetolactate synthase, acetolactate decarboxylase, and butanediol dehydrogenase, respectively) from Bacillus subtilis were engineered into a single tricistronic operon under control of the isopropyl β-D-1-thiogalactopyranoside (IPTG)-inducible Pspac promoter in a shuttle plasmid capable of replication and expression in either B. subtilis or Escherichia coli. We describe the construction and performance of a shuttle plasmid carrying the IPTG-inducible synthetic operon alsSDbdhA coding for 2,3-BD pathway capable of (i) expression in two important representative model microorganisms, the gram-positive B. subtilis and the gram-negative E. coli; (ii) increasing 2,3-BD production in B. subtilis; and (iii) successfully introducing the B. subtilis 2,3-BD pathway into E. coli. The synthetic alsSDbdhA operon constructed using B. subtilis native genes not only increased the 2,3-BD production in its native host but also efficiently expressed the pathway in the heterologous organism E. coli. Construction of an efficient shuttle plasmid will allow investigation of 2,3-BD production performance in related organisms with industrial potential for production of bio-based chemicals.

  7. Efficient production of acetoin in Saccharomyces cerevisiae by disruption of 2,3-butanediol dehydrogenase and expression of NADH oxidase.

    Science.gov (United States)

    Bae, Sang-Jeong; Kim, Sujin; Hahn, Ji-Sook

    2016-01-01

    Acetoin is widely used in food and cosmetic industry as taste and fragrance enhancer. For acetoin production in this study, Saccharomyces cerevisiae JHY605 was used as a host strain, where the production of ethanol and glycerol was largely eliminated by deleting five alcohol dehydrogenase genes (ADH1, ADH2, ADH3, ADH4, and ADH5) and two glycerol 3-phosphate dehydrogenase genes (GPD1 and GPD2). To improve acetoin production, acetoin biosynthetic genes from Bacillus subtilis encoding α-acetolactate synthase (AlsS) and α-acetolactate decarboxylase (AlsD) were overexpressed, and BDH1 encoding butanediol dehydrogenase, which converts acetoin to 2,3-butanediol, was deleted. Furthermore, by NAD(+) regeneration through overexpression of water-forming NADH oxidase (NoxE) from Lactococcus lactis, the cofactor imbalance generated during the acetoin production from glucose was successfully relieved. As a result, in fed-batch fermentation, the engineered strain JHY617-SDN produced 100.1 g/L acetoin with a yield of 0.44 g/g glucose. PMID:27279026

  8. Effects of genetic modifications and fermentation conditions on 2,3-butanediol production by alkaliphilic Bacillus subtilis.

    Science.gov (United States)

    Białkowska, Aneta M; Jędrzejczak-Krzepkowska, Marzena; Gromek, Ewa; Krysiak, Joanna; Sikora, Barbara; Kalinowska, Halina; Kubik, Celina; Schütt, Fokko; Turkiewicz, Marianna

    2016-03-01

    Two recombinants of alkaliphilic Bacillus subtilis LOCK 1086, constructed via different strategies such as cloning the gene encoding bacterial hemoglobin from Vitreoscilla stercoraria (vhb) and overexpression of the gene encoding acetoin reductase/2,3-butanediol dehydrogenase (bdhA) from B. subtilis LOCK 1086, did not produce more 2,3-butanediol (2,3-BD) than the parental strain. In batch fermentations, this strain synthesized 9.46 g/L in 24 h and 12.80 g/L 2,3-BD in 46 h from sugar beet molasses and an apple pomace hydrolysate, respectively. 2,3-BD production by B. subtilis LOCK 1086 was significantly enhanced in fed-batch fermentations. The highest 2,3-BD concentration (75.73 g/L in 114 h, productivity of 0.66 g/L × h) was obtained in the sugar beet molasses-based medium with four feedings with glucose. In a medium based on the apple pomace hydrolysate with three feedings with sucrose, B. subtilis LOCK 1086 produced up to 51.53 g/L 2,3-BD (in 120 h, productivity of 0.43 g/L × h). PMID:26590588

  9. Efficient production of 2,3-butanediol from corn stover hydrolysate by using a thermophilic Bacillus licheniformis strain.

    Science.gov (United States)

    Li, Lixiang; Li, Kun; Wang, Kai; Chen, Chao; Gao, Chao; Ma, Cuiqing; Xu, Ping

    2014-10-01

    In this study, a thermophilic Bacillus licheniformis strain X10 was newly isolated for 2,3-butanediol (2,3-BD) production from lignocellulosic hydrolysate. Strain X10 could utilize glucose and xylose simultaneously without carbon catabolite repression. In addition, strain X10 possesses high tolerance to fermentation inhibitors including furfural, vanillin, formic acid, and acetic acid. In a fed-batch fermentation, 74.0g/L of 2,3-BD was obtained from corn stover hydrolysate, with a productivity of 2.1g/Lh and a yield of 94.6%. Thus, this thermophilic B. licheniformis strain is a candidate for the development of efficient industrial production of 2,3-BD from corn stover hydrolysate.

  10. Efficient production of 2,3-butanediol from corn stover hydrolysate by using a thermophilic Bacillus licheniformis strain.

    Science.gov (United States)

    Li, Lixiang; Li, Kun; Wang, Kai; Chen, Chao; Gao, Chao; Ma, Cuiqing; Xu, Ping

    2014-10-01

    In this study, a thermophilic Bacillus licheniformis strain X10 was newly isolated for 2,3-butanediol (2,3-BD) production from lignocellulosic hydrolysate. Strain X10 could utilize glucose and xylose simultaneously without carbon catabolite repression. In addition, strain X10 possesses high tolerance to fermentation inhibitors including furfural, vanillin, formic acid, and acetic acid. In a fed-batch fermentation, 74.0g/L of 2,3-BD was obtained from corn stover hydrolysate, with a productivity of 2.1g/Lh and a yield of 94.6%. Thus, this thermophilic B. licheniformis strain is a candidate for the development of efficient industrial production of 2,3-BD from corn stover hydrolysate. PMID:25151068

  11. Techno-economic evaluation of a complete bioprocess for 2,3-butanediol production from renewable resources.

    Science.gov (United States)

    Koutinas, Apostolis A; Yepez, Bernardo; Kopsahelis, Nikolaos; Freire, Denise M G; de Castro, Aline Machado; Papanikolaou, Seraphim; Kookos, Ioannis K

    2016-03-01

    This study presents the techno-economic evaluation of 2,3-butanediol (BDO) production via fermentation using glycerol, sucrose and sugarcane molasses as carbon sources. Literature-cited experimental data were used to design the fermentation stage, whereas downstream separation of BDO was based on reactive extraction of BDO employing an aldehyde to convert BDO into an acetal that is immiscible with water. The selected downstream process can be used in all fermentations employed. Sensitivity analysis was carried out targeting the estimation of the minimum selling price (MSP) of BDO at different plant capacities and raw material purchase costs. In all cases, the MSP of BDO is higher than 1 $/kg that is considered as the target in order to characterize a fermentation product as platform chemical. The complex nutrient supplements, the raw material market price and the fermentation efficiency were identified as the major reasons for the relatively high MSP observed. PMID:26773945

  12. 2,3 Butanediol production in an obligate photoautotrophic cyanobacterium in dark conditions via diverse sugar consumption.

    Science.gov (United States)

    McEwen, Jordan T; Kanno, Masahiro; Atsumi, Shota

    2016-07-01

    Cyanobacteria are under investigation as a means to utilize light energy to directly recycle CO2 into chemical compounds currently derived from petroleum. Any large-scale photosynthetic production scheme must rely on natural sunlight for energy, thereby limiting production time to only lighted hours during the day. Here, an obligate photoautotrophic cyanobacterium was engineered for enhanced production of 2,3-butanediol (23BD) in continuous light, 12h:12h light-dark diurnal, and continuous dark conditions via supplementation with glucose or xylose. This study achieved 23BD production under diurnal conditions comparable to production under continuous light conditions. The maximum 23BD titer was 3.0gL(-1) in 10d. Also achieving chemical production under dark conditions, this work enhances the feasibility of using cyanobacteria as industrial chemical-producing microbes. PMID:26979472

  13. AI-2 Key Enzyme S-Ribosylhomocysteinase from Strain Klebsiella pneumoniae CICC 10011 Producing 2,3-Butanediol

    Institute of Scientific and Technical Information of China (English)

    DAI Jian-ying; ZHANG Li-fu; XIU Zhi-long

    2011-01-01

    S-Ribosylhomocysteinase(LuxS) is the key enzyme in the synthetic pathway of a quorum sensing autoin ducer AI-2. LuxS from a 2,3-butanediol produced strain Klebisella pneumoniae CICC 10011 was cloned and charac terized. The luxS gene is composed of 540 bp with 172 amino acids encoded. The Km value for S-ribosylhomo-cysteine(SRH) was (27+1) μmol/L, kcat was (0.112±0.004) s-1 and kcat/Km was 4.4×103 L.mol-1 s-1 at 25 ℃. LuxS was activated by divalent metal ions, the highest activity was detected with Co2+ form, followed by Mg2+, Ba2+, Mn2+,Fe2+ and Ca2+, and activation constant for Co2+ is (16±2) μmol/L.

  14. Synthesis and crystallographic analysis of meso-2,3-difluoro-1,4-butanediol and meso-1,4-dibenzyloxy-2,3-difluorobutane

    Directory of Open Access Journals (Sweden)

    Bruno Linclau

    2010-06-01

    Full Text Available A large-scale synthesis of meso-2,3-difluoro-1,4-butanediol in 5 steps from (Z-but-2-enediol is described. Crystallographic analysis of the diol and the corresponding benzyl ether reveals an anti conformation of the vicinal difluoride moiety. Monosilylation of the diol is high-yielding but all attempts to achieve chain extension through addition of alkyl Grignard and acetylide nucleophiles failed.

  15. Complete Genome Sequence of Raoultella ornithinolytica Strain B6, a 2,3-Butanediol-Producing Bacterium Isolated from Oil-Contaminated Soil.

    Science.gov (United States)

    Shin, Sang Heum; Um, Youngsoon; Beak, Jeong Hun; Kim, Sehwan; Lee, Soojin; Oh, Min-Kyu; Kim, Young-Rok; Lee, Jinwon; Yang, Kap-Seok

    2013-06-27

    Here we report the full genome sequence of Raoultella ornithinolytica strain B6, a Gram-negative aerobic bacillus belonging to the family Enterobacteriaceae. This 2,3-butanediol-producing bacterium was isolated from oil-contaminated soil on Backwoon Mountain in South Korea. Strain B6 contains 5,398,151 bp with 4,909 protein-coding genes, 104 structural RNAs, and 55.88% G+C content.

  16. Fermentation of bio-based product 2,3-butanediol%2,3-丁二醇的发酵生产

    Institute of Scientific and Technical Information of China (English)

    宋源泉; 许赟珍; 李强; 刘德华

    2011-01-01

    The development of chemical industry is hindered by energy crisis and environment pollution, and a new model of development is urgently to be exploited. Biorefining technology with renewable resources as feedstock is proposed as one possible solution, in which 2,3-butanediol fermentation is one important issue. 2,3-Butanediol, a bulk chemical product, has extensive applications, especially in chemical processes, food, fuel and medicine. The metabolic pathway of 2,3-butanediol is briefly described, and the progress of biotechnological production of 2,3-butanediol is reviewed, including microbial strains, strains mutagenization, genetic modifications and operating conditions (substrates, pH value, aeration, temperature and fermentation mode). Finally, 2,3-butanediol fermentation research directions are proposed.%能源危机和环境污染使得化工行业的发展举步维艰,亟待开发新的发展模式,以可再生能源为原料的生物炼制技术成为可行的途径之一.2,3-丁二醇的发酵生产是现代生物炼制的重要课题之一.2,3-丁二醇作为一种大宗的化学产品具有广泛的应用价值,尤其在化工、食品、燃料、医药等领域.本文简要描述了2,3-丁二醇在微生物体内的代谢途径,着重讨论了2,3-丁二醇的发酵生产,对发酵的菌种种类、菌种诱变和定向改造、各种发酵影响因素(包括底物、pH值、溶氧、温度以及发酵方式)进行了详细的归纳总结,同时展望了2,3-丁二醇发酵生产的研究发展方向.

  17. Progress on the separation of 2,3-butanediol%2,3-丁二醇分离提取工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    樊亚超; 张霖; 廖莎; 王领民

    2016-01-01

    2,3-丁二醇应用广泛,是一种潜在的平台化合物,可以用于替代传统平台化合物——四碳烃。基于能源安全及绿色环保的需求,生物炼制制备2,3-丁二醇受到人们的青睐。与化学法相比,生物炼制制备2,3-丁二醇具有明显的优势。然而,2,3-丁二醇的高沸点及强极性的特点使它难以从发酵液中分离。这成为了生物炼制2,3-丁二醇工艺工业化的瓶颈。因此,开发高效价廉的2,3-丁二醇分离工艺成为研究的重点。本文综述了从发酵液中分离2,3-丁二醇工艺的研究进展。2,3-丁二醇的分离主要包括固液分离、发酵液深处理及2,3-丁二醇精制3个方面,涉及的分离技术包括离心、絮凝、膜过滤、离子交换、电渗析、萃取、精馏等以及相关技术的优化和耦合。提出今后的研究重点在于现有分离工艺的高效整合及新型分离工艺的有效突破。%As a potential platform compound,2,3-butanediol is used widely and can replace the traditional platforms——four carbon hydrocarbons.With the requirements of energy security and environmental protection,biological refinery of 2,3-butanediol have gained substantial interest due to its obvious advantages over the chemical method. However,due to the high boiling point and hydrophilicity of 2,3-butanediol,it is very difficult to be recovered from fermentation broth,which has become the bottle-neck of industrial production of 2,3-butanediol. Therefore,it is important to develop cost effective process to separate 2,3-butanediol. The progress is reviewed on the downstream processing of 2,3-butanediol fermentation. The process contains mainly three steps:solid-liquid separation,deep treatment of broth and purification of 2,3-butanediol. Many technologies have been involved,such as centrifugation,flocculation,membrane filtration,ion exchange,electrodialysis, extraction,distillation and so on,and their optimization and combinations. In

  18. Latest Advances of Microbial Production of 2,3-Butanediol%生物法制备2,3-丁二醇的最新进展

    Institute of Scientific and Technical Information of China (English)

    付晶; 王萌; 刘维喜; 陈涛

    2012-01-01

    As important liquid fuel and chemical raw materials, 2,3-butanediol and its derivatives have broad industrial application prospects. Economical and efficient 2,3-butanediol microbial production has significant impetus to the low-carbon and circular economy development of China. Focusing on the latest achievements in the microbial production of 2, 3-butanediol, this review summarizes the hot spots of the researchers' attentions nowadays, which can be divided into four parts : identification of the key genes and enzymes involved in the 2,3- butanediol metabolic pathway, development of new strains and metabolic engineered strains for high yield or chiral 2,3-butanediol production, strategies for fermentation optimization such as simultaneous saccharification and fermentation, and technology improvement for combining process involved in 2,3-butanediol recovering processing. These achievements in the last three years are classified and discussed with state-of-art views. At last, guidelines for future studies are also proposed. It is pointed out that future research should focus on new strains, new genes and enzymes, new metabolic pathways, new cheap and renewable resources for substrate, and new technology for fermentation and separation. There's no doubt that metabolic engineered class I strains, which can utilize cost- effective and renewable substrates to lower the raw materials cost producing chiral 2,3-butanediol with high yield and productivity, should be favored. Besides, new technology in separation and purification process must be developed and improved to lower the cost of downstream processing.%2,3-丁二醇及其衍生物作为重要的液体燃料和化工原料,具有广阔的工业应用前景。高效、经济的2,3-丁二醇生物制备方法,对我国低碳经济和循环经济的建设具有重要的促进作用。针对近三年间生物法制备2,3-丁二醇领域的最新研究成果,本文综述了当前国内外学者在该领域研究的热点,

  19. LCA of 1,4-Butanediol Produced via Direct Fermentation of Sugars from Wheat Straw Feedstock within a Territorial Biorefinery

    Directory of Open Access Journals (Sweden)

    Annachiara Forte

    2016-07-01

    Full Text Available The bio-based industrial sector has been recognized by the European Union as a priority area toward sustainability, however, the environmental profile of bio-based products needs to be further addressed. This study investigated, through the Life Cycle Assessment (LCA approach, the environmental performance of bio-based 1,4-butanediol (BDO produced via direct fermentation of sugars from wheat straw, within a hypothetical regional biorefinery (Campania Region, Southern Italy. The aim was: (i to identify the hotspots along the production chain; and (ii to assess the potential environmental benefits of this bio-based polymer versus the reference conventional product (fossil-based BDO. Results identified the prevailing contribution to the total environmental load of bio-based BDO in the feedstock production and in the heat requirement at the biorefinery plant. The modeled industrial bio-based BDO supply chain, showed a general reduction of the environmental impacts compared to the fossil-based BDO. The lowest benefits were gained in terms of acidification and eutrophication, due to the environmental load of the crop phase for feedstock cultivation.

  20. Enzymatic hydrolysis of various pretreated lignocellulosic substrates and the fermentation of the liberated sugars to ethanol and butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Saddler, J.N.; Mes-Hartree, M.; Yu, E.K.C.; Brownell, H.H.

    1983-01-01

    Aspen wood and wheat straw were pretreated by exposure to steam at elevated temperatures. Chemical analysis of the substrates revealed that steam explosion differentially decomposed the pentosan component while leaving the glucan portion relatively unchanged. The pretreated residues could be used as substrates for growth of Trichoderma reesei C30 and T. harzianum E58. The cellulase activities detected were in some cases three times as high as those found when Solka Floc was used as the substrate. Culture filtrates of T. harzianum E58 could efficiently hydrolyze the hemicellulose-rich water-soluble fractions. This material was fermented by Klebsiella pneumoniae with 0.4-0.5 g of 2,3-butanediol produced per gram of sugar utilized. Once the steam-exploded residues had been water and alkali extracted, the enzymatically hydrolyzed substrates were readily fermented by Saccharomyces cerevisiae or Zymononas mobilis with values as high as 2% (w/v) ethanol obtained from 5% steam-exploded wood fractions. 30 references, 2 figures, 8 tables.

  1. Glucose tracer, kinetics and turnover in monkeys and chickens infused with ethanol, 1,3-butanediol, or fructose

    International Nuclear Information System (INIS)

    Mixtures of (2-3H) and (U-14C) glucose were injected as single doses into fasted cynomolgus monkeys to assess glucose tracer kinetics and obtain rates of turnover. Data were treated by stochastic and compartmental analyses and results from both analyses closely agreed. However, (2-3H) data analyzed by the compartmental analysis required three pools to fit the glucose disappearance curve while (6-3H) data fit a two or three pool model equally well. Turnover rates averaged 4.9-4.0, and 3.0 mg/min x kg-1 body weight with (2-3H), 6-3H) and (U-14C) glucose tracers, respectively. The data heuristically suggest that the slow turnover pool that was necessary to fit (2-3H) glucose data is related to isotope discrimination. The effects of four treatment solutions on (6-3H) glucose metabolism in monkeys were examined. The solutions and their rates of infusion (umoles/min x kg-1) were: (1) ethanol, 110; (2) 1,3-butanediol, 110; (3) fructose, 30; and (4) ethanol pus fructose, 110 and 30, respectively. The glucose clearance rate was lowest during the ethanol plus fructose infusions. Ethanol infusions (222 or 444 umoles/min x kg-1 body weight) in chickens (1500 g) fasted 64 hours did not cause hypoglycemia although the high dose slightly decreased the rate of glucose turnover 15% (14.0 versus 12.0 mg/min x kg-1). It was further found that neither the hepatic cytosolic nor the mitochondrial redox state significantly changed in chickens infused with the high dose of ethanol. The unchanged hepatic metabolite ratios in chickens are consistent with their unusual resistance to ethanol-induced hypoglycemia

  2. Dynamic polarization of protons in 2,3-butanediol doped with Cr(V)- complex and in other materials containing adjacent hydroxyl groups

    CERN Document Server

    Guckelsberger, K

    1977-01-01

    Results are given on 2,3-butanediol doped with Cr(V)-complex as a material for polarized proton targets. It is shown to be an improvement over the presently used 1,2-propanediol since its chemical composition is slightly more favourable and its melting point is near room temperature. Maximum polarization, nuclear relaxation time, reversal time, minimum power requirement, radiation resistance, and annealing temperature are all very similar to 1,2-propanediol. A review of other materials containing adjacent hydroxyl groups is made, and conclusions are drawn as to their possible use as target materials. (17 refs).

  3. (Liquid + liquid) phase equilibria for (water + 2,3-butanediol + oleyl alcohol) at T = (300.2, 307.2, and 314.2) K

    Energy Technology Data Exchange (ETDEWEB)

    Khayati, Gholam [Department of Chemical Engineering, Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-143 Tehran (Iran, Islamic Republic of); Pahlavanzadeh, Hassan [Department of Chemical Engineering, Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-143 Tehran (Iran, Islamic Republic of)], E-mail: pahlavzh@modares.ac.ir; Vasheghani-Farahani, Ebrahim [Department of Chemical Engineering, Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-143 Tehran (Iran, Islamic Republic of); Ghaemi, Nasser [Department of Biotechnology, University College of Science, University of Tehran (Iran, Islamic Republic of)

    2009-02-15

    (Liquid + liquid equilibrium) (LLE) data for ternary system: (water + 2,3-butanediol + oleyl alcohol) has been measured at T = (300.2, 307.2, and 314.2) K. Complete phase diagrams were obtained by determining solubility and tie-line data. Tie-line compositions were correlated by Othmer-Tobias and Bachman methods. The nonrandom two liquids equation (NRTL) was used to correlate the phase equilibrium in the system using the interaction parameters determined from experimental data. It is found that NRTL could give a good correlation for the LLE data. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  4. Process Optimization on Micro-Aeration Supply for High Production Yield of 2,3-Butanediol from Maltodextrin by Metabolically-Engineered Klebsiella oxytoca.

    Science.gov (United States)

    Chan, Sitha; Jantama, Sirima Suvarnakuta; Kanchanatawee, Sunthorn; Jantama, Kaemwich

    2016-01-01

    An optimization process with a cheap and abundant substrate is considered one of the factors affecting the price of the production of economical 2,3-Butanediol (2,3-BD). A combination of the conventional method and response surface methodology (RSM) was applied in this study. The optimized levels of pH, aeration rate, agitation speed, and substrate concentration (maltodextrin) were investigated to determine the cost-effectiveness of fermentative 2,3-BD production by metabolically-engineered Klebsiella oxytoca KMS005. Results revealed that pH, aeration rate, agitation speed, and maltodextrin concentration at levels of 6.0, 0.8 vvm, 400 rpm, and 150 g/L respectively were the optimal conditions. RSM also indicated that the agitation speed was the most influential parameter when either agitation and aeration interaction or agitation and substrate concentration interaction played important roles for 2,3-BD production by the strain from maltodextrin. Under interim fed-batch fermentation, 2,3-BD concentration, yield, and productivity were obtained at 88.1±0.2 g/L, 0.412±0.001 g/g, and 1.13±0.01 g/L/h respectively within 78 h. PMID:27603922

  5. In silico metabolic engineering of Bacillus subtilis for improved production of riboflavin, Egl-237, (R,R)-2,3-butanediol and isobutanol.

    Science.gov (United States)

    Hao, Tong; Han, Binbin; Ma, Hongwu; Fu, Jing; Wang, Hui; Wang, Zhiwen; Tang, Bincai; Chen, Tao; Zhao, Xueming

    2013-08-01

    Bacillus subtilis is a Gram-positive sporiferous bacterium widely used in a variety of industrial fields as a producer of high-quality vitamins, enzymes and proteins. Many genetic modifications and evolutionary engineering optimisations aiming at obtaining a better performing strain for its products have been studied. As genome-scale metabolic network models have gained significant popularity as effective tools in metabolic phenotype studies, we reconstructed a genome-scale metabolic network of B. subtilis-iBsu1147. The accuracy of iBsu1147 is validated by growth on various carbon sources, single gene knockout and large fragment non-essential gene knockout simulations. The model is used for the in silico metabolic engineering design of reactions over/underexpressed or knockout for increasing the production of four important products of B. subtilis: riboflavin, cellulase Egl-237, (R,R)-2,3-butanediol and isobutanol. The simulation predicted candidate reactions related to the improvement of strain performance on related products. The prediction is partly supported by previously published results. Due to the complexity of the biological system, it is difficult to manually find the factors that are not directly related to the production of the target compounds. The in silico predictions provide more choices for further strain improvement for these products. PMID:23666098

  6. Effects of mutation of 2,3-butanediol formation pathway on glycerol metabolism and 1,3-propanediol production by Klebsiella pneumoniae J2B.

    Science.gov (United States)

    Kumar, Vinod; Durgapal, Meetu; Sankaranarayanan, Mugesh; Somasundar, Ashok; Rathnasingh, Chelladurai; Song, HyoHak; Seung, Doyoung; Park, Sunghoon

    2016-08-01

    The current study investigates the impact of mutation of 2,3-butanediol (BDO) formation pathway on glycerol metabolism and 1,3-propanediol (PDO) production by lactate dehydrogenase deficient mutant of Klebsiella pneumoniae J2B. To this end, BDO pathway genes, budA, budB, budC and budO (whole-bud operon), were deleted from K. pneumoniae J2B ΔldhA and the mutants were studied for glycerol metabolism and alcohols (PDO, BDO) production. ΔbudO-mutant-only could completely abolish BDO production, but with reductions in cell growth and PDO production. By modifying the culture medium, the ΔbudO mutant could recover its performance on the flask scale. However, in bioreactor experiments, the ΔbudO mutant accumulated a significant amount of pyruvate (>73mM) in the late phase and PDO production stopped concomitantly. Glycolytic intermediates of glycerol, especially glyceraldehyde-3-phosphate (G3P) was highly inhibitory to glycerol dehydratase (GDHt); its accumulation, followed by pyruvate accumulation, was assumed to be responsible for the ΔbudO mutant's low PDO production. PMID:27160953

  7. Combining metabolic engineering and biocompatible chemistry for high-yield production of homo-diacetyl and homo-(S,S)-2,3-butanediol.

    Science.gov (United States)

    Liu, Jianming; Chan, Siu Hung Joshua; Brock-Nannestad, Theis; Chen, Jun; Lee, Sang Yup; Solem, Christian; Jensen, Peter Ruhdal

    2016-07-01

    Biocompatible chemistry is gaining increasing attention because of its potential within biotechnology for expanding the repertoire of biological transformations carried out by enzymes. Here we demonstrate how biocompatible chemistry can be used for synthesizing valuable compounds as well as for linking metabolic pathways to achieve redox balance and rescued growth. By comprehensive rerouting of metabolism, activation of respiration, and finally metal ion catalysis, we successfully managed to convert the homolactic bacterium Lactococcus lactis into a homo-diacetyl producer with high titer (95mM or 8.2g/L) and high yield (87% of the theoretical maximum). Subsequently, the pathway was extended to (S,S)-2,3-butanediol (S-BDO) through efficiently linking two metabolic pathways via chemical catalysis. This resulted in efficient homo-S-BDO production with a titer of 74mM (6.7g/L) S-BDO and a yield of 82%. The diacetyl and S-BDO production rates and yields obtained are the highest ever reported, demonstrating the promising combination of metabolic engineering and biocompatible chemistry as well as the great potential of L. lactis as a new production platform.

  8. Novel hydrogels based on carboxyl pullulan and collagen crosslinking with 1, 4-butanediol diglycidylether for use as a dermal filler: initial in vitro and in vivo investigations.

    Science.gov (United States)

    Li, Xian; Xue, Wenjiao; Zhu, Chenhui; Fan, Daidi; Liu, Yannan; XiaoxuanMa

    2015-12-01

    Novel hydrogels based on carboxyl pullulan (PC) and human-like collagen (HLC) crosslinking with 1,4-butanediol diglycidyl ether (BDDE) are promising soft fillers for tissue engineering due to their highly tunable properties. Recent studies, however, have shown that incorporating hyaluronic acid and BDDE results in hydrogels with a microporous structure, a large pore size and high porosity, which reduce cell adhesion and enhance degradation in vivo. To improve biocompatibility and prevent biodegradation, the use of PC to replace hyaluronic acid in the fabrication of PC/BDDE (PCB) and PC/BDDE/HLC (PCBH) hydrogels was investigated. Preparation of gels with PC is a promising strategy due to the high reactivity, superb selectivity, and mild reaction conditions of PC. In particular, the Schiff base reaction of HLC and PC produces the novel functional group -RCONHR' in PCBH hydrogels. Twenty-four weeks after subcutaneous injection of either PCB or PCBH hydrogel in mice, the surrounding tissue inflammation, enzymatic response and cell attachment were better compared to hyaluronic acid-based hydrogels. However, the biocompatibility, cytocompatibility and non-biodegradability of PCBH were milder than those of the PCB hydrogels both in vivo and in vitro. These results show that the proposed use of PC and HLC for the fabrication of hydrogels is a promising strategy for generating soft filler for tissue engineering.

  9. Screening of bacterial strains capable of converting biodiesel-derived raw glycerol into 1,3-propanediol, 2,3-butanediol and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Metsoviti, Maria; Paramithiotis, Spiros; Drosinos, Eleftherios H.; Galiotou-Panayotou, Maria; Nychas, George-John E.; Papanikolaou, Seraphim [Department of Food Science and Technology, Agricultural University of Athens, Athens (Greece); Zeng, An-Ping [Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology (TUHH), Hamburg (Germany)

    2012-02-15

    The ability of bacterial strains to assimilate glycerol derived from biodiesel facilities to produce metabolic compounds of importance for the food, textile and chemical industry, such as 1,3-propanediol (PD), 2,3-butanediol (BD) and ethanol (EtOH), was assessed. The screening of 84 bacterial strains was performed using glycerol as carbon source. After initial trials, 12 strains were identified capable of consuming raw glycerol under anaerobic conditions, whereas 5 strains consumed glycerol under aerobiosis. A plethora of metabolic compounds was synthesized; in anaerobic batch-bioreactor cultures PD in quantities up to 11.3 g/L was produced by Clostridium butyricum NRRL B-23495, while the respective value was 10.1 g/L for a newly isolated Citrobacter freundii. Adaptation of Cl. butyricum at higher initial glycerol concentration resulted in a PD{sub max} concentration of {proportional_to}32 g/L. BD was produced by a new Enterobacter aerogenes isolate in shake-flask experiments, under fully aerobic conditions, with a maximum concentration of {proportional_to}22 g/L which was achieved at an initial glycerol quantity of 55 g/L. A new Klebsiella oxytoca isolate converted waste glycerol into mixtures of PD, BD and EtOH at various ratios. Finally, another new C. freundii isolate converted waste glycerol into EtOH in anaerobic batch-bioreactor cultures with constant pH, achieving a final EtOH concentration of 14.5 g/L, a conversion yield of 0.45 g/g and a volumetric productivity of {proportional_to}0.7 g/L/h. As a conclusion, the current study confirmed the utilization of biodiesel-derived raw glycerol as an appropriate substrate for the production of PD, BD and EtOH by several newly isolated bacterial strains under different experimental conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. The implementation of high fermentative 2,3-butanediol production from xylose by simultaneous additions of yeast extract, Na2EDTA, and acetic acid.

    Science.gov (United States)

    Wang, Xiao-Xiong; Hu, Hong-Ying; Liu, De-Hua; Song, Yuan-Quan

    2016-01-25

    The effective use of xylose may significantly enhance the feasibility of using lignocellulosic hydrolysate to produce 2,3-butanediol (2,3-BD). Previous difficulties in 2,3-BD production include that the high-concentration xylose cannot be converted completely and the fermentation rate is slow. This study investigated the effects of yeast extract, ethylenediaminetetraacetic acid disodium salt (Na2EDTA), and acetic acid on 2,3-BD production from xylose. The central composite design approach was used to optimize the concentrations of these components. It was found that simultaneous addition of yeast extract, Na2EDTA, and acetic acid could significantly improve 2,3-BD production. The optimal concentrations of yeast extract, Na2EDTA, and acetic acid were 35.2, 1.2, and 4.5 g/L, respectively. The 2,3-BD concentration in the optimized medium reached 39.7 g/L after 48 hours of shake flask fermentation, the highest value ever reported in such a short period. The xylose utilization ratio and the 2,3-BD concentration increased to 99.0% and 42.7 g/L, respectively, after 48 hours of stirred batch fermentation. Furthermore, the 2,3-BD yield was 0.475 g/g, 95.0% of the theoretical maximum value. As the major components of lignocellulosic hydrolysate are glucose, xylose, and acetic acid, the results of this study indicate the possibility of directly using the hydrolysate to effectively produce 2,3-BD.

  11. Study of the effect of mixing approach on cross-linking efficiency of hyaluronic acid-based hydrogel cross-linked with 1,4-butanediol diglycidyl ether.

    Science.gov (United States)

    Al-Sibani, Mohammed; Al-Harrasi, Ahmed; Neubert, Reinhard H H

    2016-08-25

    Regardless of various strategies reported for cross-linking hyaluronic acid (HA) with 1,4-butanediol diglycidyl ether (BDDE), seeking new strategies that enhance cross-linking efficiency with a low level of cross-linker is essential. In this work, we studied the influence of mixing approach on two cross-linked BDDE-HA hydrogels prepared by two different mixing approaches; the large-batch mixing approach in which the hydrogel quantities were all mixed as a single lump in one container (hydrogel 1), and the small-batches mixing approach in which the hydrogel quantities were divided into smaller batches, mixed separately at various HA/BDDE ratios then combined in one reaction mixture (hydrogel 2). The result showed that the cross-linking reaction was mixing process-dependent. Degradation tests proved that, in relation to hydrogel 1, hydrogel 2 was more stable, and exhibited a higher resistance towards hyaluronidase activity. The swelling ratio of hydrogel 1 was significantly higher than that of hydrogel 2 in distilled water; however, in phosphate buffer saline, both hydrogels showed no significant difference. SEM images demonstrated that hydrogel 2 composite showed a denser network structure and smaller pore-size than hydrogel 1. In comparison to native HA, the occurrence of chemical modification in the cross-linked hydrogels was confirmed by FTIR and NMR distinctive peaks. These peaks also provided evidence that hydrogel 2 exhibited a higher degree of modification than hydrogel 1. In conclusion, the small-batches mixing approach proved to be more effective than large-batch mixing in promoting HA-HA entanglement and increasing the probability of BDDE molecules for binding with HA chains. PMID:27312477

  12. Study on 1,4-butanediol wastewater treatment%1,4-丁二醇生产废水处理中试研究

    Institute of Scientific and Technical Information of China (English)

    吴英; 祝双燕; 曹斌; 王丽春

    2015-01-01

    1,4-butanediol(BDO) wastewater contains formaldehyde which is so refractory and toxic with great water quality and quantity changes,that it is difficult to be treated. The combined system,pre-aerated hydrolytic acidifica-tion reactor-anaerobic reactor-contact oxidation-membrane bioreactor ,has been constructed for treating the BDO wastewater. Pre-aerated hydrolytic acidification reactor can effectively reduce the formaldehyde concentration so that the toxicity of wastewater can be reduced. At the same time ,the biodegradability of wastewater can be improved by both of the pre-aerated hydrolytic acidification reactor and the anaerobic reactor. COD removing efficiency of the system reaches 90%above,and effluent COD can meet the requirements for the first grade of Integrated Wastewater Discharge Standard(GB 8978—1996).%1,4-丁二醇(BDO)生产废水含甲醛,难降解、毒性大、水质水量变化大,处理难度高。试验构建了预曝气水解酸化-高效厌氧反应器-接触氧化-膜生物反应器组合系统处理BDO废水。预曝气水解酸化可有效降低甲醛浓度,降低废水毒性。同时预曝气水解酸化和高效厌氧反应器均可提高废水的可生化性。系统对废水COD的去除率达到90%以上,出水COD满足国家《污水综合排放标准》(GB 8978—1996)一级标准。

  13. 11B NMR study of easter formation and complexing in the polyborate existence region of H3BO3-NaOH-H2O-2,3-butanediol system

    International Nuclear Information System (INIS)

    Interactions in concentrated solutions of boric acid and sodium hydroxide mixtures at pH 9 with 2,3-butanediol (BD) have been studied by 11B NMR spectroscopy method. With an increase in BD concentration a cyclic esters of boric acid (BD)BOH is formed, as well as complex anions [(BD)B(OH)2]-, [(BD)2B]- and [(BD)B3O3(OH)2]-. Polyion [B5O6(OH)4]- with addition of BD excess is partially hydrolyzed into monoborate-ion and boric acid, which react instantly with BD excess giving rise to formation of the relevant complex anions and ester

  14. 棉秆脱毒水解液发酵生产2,3-丁二醇的工艺优化%Process optimization for producing 2, 3-butanediol by fermentation of cotton stalk hydrolysate after detoxification

    Institute of Scientific and Technical Information of China (English)

    张根林; 江英兰; 班丽丽

    2011-01-01

    2,3-Butanediol is an important chemical product. Utilization of cotton stalk hydrolysate instead of starch for 2,3 -butanediol production can ensure food security and reduce costs. Cotton stalk was hydrolyzed by dilute acid in this research. The detoxification of furfural and phenol from cotton stalk dilute acid hydrolysate was performed by microwave assistant heating-activated carbon adsorption method, the optimized technical conditions were determined as activated carbon 1%, microwave power 330 W and detoxification time 10 min. The detoxification ratio of furfural was 81.2% and 92.3% of phenol, and the loss of total sugar was only 10.6%. The batch cultures showed that the biomass of Klebsiella pneumoniae XJ-Li and the yield of 2,3-butanediol reached to peak value when the total sugar concentration was 40 g/L in media. The results of research demonstrated that the inhibition effect of high concentration of cotton stalk hydrolysate on the growth and metabolic of microorganism could be reduced by fed-batch fermentation. The multiplexed regulation method of adding 60 mg/L of vitamin C into media and maintaining pH of broth at 5.5 was applied, and 45.1 g/L of 2,3-butanediol was reached with the yield of 0.45 g/g. The cornhusk dilute acid hydrolysate after detoxification can be the substitution of glucose as a carbon source for producing succinic acid by anaerobic fermentation.Fermentation experiments showed that it is feasible to produce 2,3-butanediol by fermentation using cotton stalks hydrolyzate detoxified as a carbon source.%2,3-丁二醇是一种重要的化工产品,利用棉秆水解液替代淀粉原料制备2,3-丁二醇可保证粮食安全并降低成本.该文以棉秆稀酸水解液为基础,研究了其中糠醛和苯酚微波辅助加热-活性炭吸附的脱毒条件,优化结果为:活性炭用量1%、微波功率330 W、作用时间10 min.在此工艺条件下,糠醛的去除率为81.2%,苯酚的脱除率为92.3%,总糖的损失为10.6%.脱

  15. 利用肺炎克雷伯氏菌以葡萄糖和磷酸铵盐为底物生产2,3-丁二醇%Production of 2,3-Butanediol by Klebsiella Pneumoniae Using Glucose and Ammonium Phosphate

    Institute of Scientific and Technical Information of China (English)

    秦加阳; 肖梓军; 马翠卿; 谢能中; 刘培海; 许平

    2006-01-01

    The production of 2,3-butanediol by Klebsiella pneumoniae from glucose supplemented with different salts was studied. A suitable medium composition was defined by response surface experiments. In a medium containing glucose and (NH4)2HPO4, the strain could convert 137.0g of glucose into 52.4g of 2,3-butanediol and 8.4g of acetoin in shaking flasks. The diol yield amounted to 90% of its theoretical value and the productivity was 1-1.5g·L-1·h-1. In fed-batch fermentation, the yield and productivity of diol were further enhanced by maintaining the pH at 6.0. Up to 92.4g of 2,3-butanediol and 13.1g of acetoin per liter were obtained from 215.0g of glucose per liter. The diol yield reached 98% of its theoretical value and the productivity was up to 2.1g·L-1·h-1.

  16. Comparative study of equimolar doses of gamma-hydroxybutyrate (GHB), 1,4-butanediol (1,4-BD) and gamma-butyrolactone (GBL) on catalepsy after acute and chronic administration.

    Science.gov (United States)

    Towiwat, Pasarapa; Phattanarudee, Siripan; Maher, Timothy J

    2013-01-01

    Gamma-hydroxybutyrate (GHB), and its precursors 1,4-butanediol (1,4-BD) and gamma-butyrolactone (GBL) are known drugs of abuse. The ability of acute and chronic administration of equimolar doses of GHB (200mg/kg), 1,4-BD (174mg/kg) and GBL (166mg/kg) to produce catalepsy in male Swiss Webster mice was examined. GHB, 1,4-BD, GBL produced catalepsy when injected acutely. Drug treatment was then continued for 14days. Tolerance development was determined on days 6, 14, and challenged with a higher dose on day 15 in those chronically pretreated mice, and compared with naïve mice. Chronic GHB produced tolerance to catalepsy, as evidenced from area under the curve (AUC) of catalepsy versus time (min-sec) on days 6 (678±254), 14 (272±247), which were less than those on day 1 (1923±269). However, less tolerance was seen from GBL or 1,4-BD, as AUCs on days 6 and 14 were not significantly lower than that of day 1. In conclusion, although equimolar doses were used, expecting similar levels of GHB in the body, 1,4-BD and GBL shared only some of the in vivo effects of GHB. The rate of metabolic conversion of 1,4-BD and GBL into GHB might be responsible for the differences in the tolerance development to these drugs.

  17. Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4-butanediol (1,4-BD; BDO): A literature review with a focus on UK fatalities related to non-medical use.

    Science.gov (United States)

    Corkery, John M; Loi, Barbara; Claridge, Hugh; Goodair, Christine; Corazza, Ornella; Elliott, Simon; Schifano, Fabrizio

    2015-06-01

    Misuse of gamma hydroxybutrate (GHB) and gamma butyrolactone (GBL) has increased greatly since the early 1990s, being implicated in a rising number of deaths. This paper reviews knowledge on GHB and derivatives, and explores the largest series of deaths associated with their non-medical use. Descriptive analyses of cases associated with GHB/GBL and 1,4-butanediol (1,4-BD) use extracted from the UK's National Programme on Substance Abuse Deaths database. From 1995 to September 2013, 159 GHB/GBL-associated fatalities were reported. Typical victims: White (92%); young (mean age 32 years); male (82%); with a drug misuse history (70%). Most deaths (79%) were accidental or related to drug use, the remainder (potential) suicides. GHB/GBL alone was implicated in 37%; alcohol 14%; other drugs 28%; other drugs and alcohol 15%. Its endogenous nature and rapid elimination limit toxicological detection. Post-mortem blood levels: mean 482 (range 0-6500; SD 758)mg/L. Results suggest significant caution is needed when ingesting GHB/GBL, particularly with alcohol, benzodiazepines, opiates, stimulants, and ketamine. More awareness is needed about risks associated with consumption.

  18. 己二酸-1,4-丁二醇-尿素共聚物的合成与表征%Synthesis, characterization of adipic acid-l, 4-butanediol-urea copolymer

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 谢伟; 刘亦武; 刘磅

    2012-01-01

    A novel adipic acid copolymer was synthesized via condensation polymerization with adipic acid, urea and, 1,4-butanediol as the raw materials. The influences of reaction time, catalyst, mass ratio of raw materials and the temperature on the property of copolymer were investigated. The structure, thermodynamic perform- ance and the molecular weights of the eopolymer were characterized by fourier transform infrared (FT-IR), 1 H- NMR spectrum, gel permeation chromatography (GPG) and thermogravimeter-differential scanning calorimeter (TG-DSC) respectively. The results show that under the condition of 220℃, 10h, the optimal feed molar ratios n (1,4-butanediol and urea)/n (adipic acid) == 1.16 : 1, n (adipie acid)/n (urea) = 5 : 1, the amount of catalyst was 0.03wt %), a desired adipic acid copolymer whose weight-average molecular weight reaches 12700 could be obtained. The prepared copolymer has higher thermostability, degradability and good appearance.%以己二酸、1,4-丁二醇和尿素为原料,在氩气环境下,通过高温熔融缩聚反应合成了一种新型可降解的己二酸-丁二醇-尿素共聚物,并对反应时间、催化剂种类及其用量、原料配比、反应温度等因素对聚合产物的影响进行了研究。采用红外光谱(FT-IR)、核磁共振(1H-NMR)、凝胶渗透色谱(GPC)、热重分析(TG)、差示量热扫描(DSC)对产物的结构与性能进行了表征。结果表明,当丁二醇和尿素的总量与己二酸(n(丁二醇+尿素)∶n(己二酸))的摩尔比为1.16∶1,丁二醇和尿素(n(1,4-丁二醇)∶n(尿素))的摩尔比为5∶1,最高反应温度为220℃,二月桂酸二丁基锡为催化剂且用量为原料总量的0.03%,总反应时间10h,所得到产物的重均分子量(Mw)可达12700,其颜色、热稳定性和降解性能等较好。

  19. Scientific Opinion on the safety assessment of the substances (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, for use in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the additives (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, (FCM substance Nos 998, 859 and 1043, intended to be used up to 10 % w/w as an impact modifier in rigid (unplasticized polyvinylchloride (PVC. The final material is intended to be used for contact with all food types, at room temperature or lower, for long time storage. The monomers constituting the copolymer are listed in Regulation (EU 10/2011. The migration from PVC of the low molecular weight fraction of the additive below 1000 Da was estimated to be about 0.009 mg/kg food. Considering that these low molecular weight oligomers are made from authorised monomers, which by reaction are expected to lack the reactive functional groups, they do not give rise to safety concern. The migration of the additive in nanoparticle form from the PVC was estimated, using conservative migration modelling, to be about 1 x 10-6 mg/kg food and so consumer exposure would be very low, if any. The CEF Panel concluded that there is no safety concern for the consumer if the substances are used as additives individually or in combination at up to a total of 10 % w/w in rigid PVC used in contact with all food types at ambient temperature or below including long-term storage.

  20. 1,4-丁二醇蒸馏底物解聚溶液组成的分析方法%The Analytical Method for the Composion of Depolymerization Solution of 1,4-Butanediol's Distillation Substrate

    Institute of Scientific and Technical Information of China (English)

    王毓嘉; 王攀; 魏顺安; 董立春; 杨楠; 尤新强

    2012-01-01

    Liquid-liquid extraction ( LLE) was used to analyze the contents of 1,4-butanediol( BDO) in the depolymerization solution. The LLE data for the system were measured at 30 ℃, when n-octanol was used as extracting reagent. Activity coefficient models were established to correlate the LLE data of the system using the Extended-UNIQUAC equation, in which the binary interaction energy parameters of water + BDO + n-octanol ternary system were obtained through a simplex fitting method. The results show that the composition of raffinate phase can be predicted reliably by analyzing the composition of extract phase. Therefore, the contents of BDO in the solution can be calculated. The method is accurate and simple and can be used as the common analytic method for this system.%使用液液萃取法分析溶液中的1,4-丁二醇(BDO)含量,正辛醇作为萃取剂,在30℃下测定了水-BDO-正辛醇三元液液相平衡数据.使用扩展型UNIQUAC模型建立了溶液中水-BDO-正辛醇的活度系数模型,关联该体系的液液平衡数据,通过单纯型法回归获得三元体系组分之间的相互作用能参数.实验数据以及计算结果表明,通过分析萃取相的组成,能可靠地预测萃余相的组成,进而得到原溶液中BDO的含量.该法准确、简便,可作为该体系的常规分析方法.

  1. 乙酸、糠醛和5-羟甲基糠醛对产酸克雷伯氏菌发酵生产2,3-丁二醇的影响%Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca

    Institute of Scientific and Technical Information of China (English)

    吴晶; 程可可; 李文英; 冯杰; 张建安

    2013-01-01

    To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal.%为了解产酸克雷伯氏菌对木质纤维素水解液中主要抑制物的耐受和代谢,考察了产酸克雷伯氏菌发酵生产2,3-丁二醇(2,3-butanediol,2,3-BDO)过程中对3种发酵抑制物乙酸、糠醛和5-羟甲基糠醛(5-hydroxymethylfurfural HMF)的耐受以及抑制物浓度的变化,检测了糠醛和HMF的代谢产物.结果表明:产酸克雷伯氏菌对乙酸、糠醛和HMF的耐受浓度分别为30 g/L、4 g/L和5 g/L.并且部分乙酸可作为生产2,3-丁二醇的底物,在0~30 g/L浓度范围内可提高2,3-丁二醇的产量.发酵过程中产酸克雷伯氏菌可将HMF和糠醛全部转化,其中约70%HMF被转化为2,5-呋喃二甲醇,30%HMF和全部糠醛被菌体代谢.研究表明在木质纤维素水解液生产2,3-丁二醇的脱毒过程中可优先考虑脱除糠醛,一定浓度的乙酸可以不用脱除.

  2. Preparation and Properties of Poly(Succinic Acid-1,4-Butanediol-Urea) Polyester Ureide%丁二酸-1,4-丁二醇-尿素聚酯酰脲共聚物的制备与性能

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 刘磅; 冯正洋; 戴红

    2015-01-01

    A biodegradable poly(succinic acid -1,4-Butanediol - urea ) polyester ureide(PEU) was synthesized via melt phase polycondensation and chain extension reaction under argon atmosphere using succinic acid, 1,4-butanediol and urea as raw materials, and related polyester ureide films were prepared through a rolling film-forming method. The structure and properties of the films were studied by infrared spectroscopy (FT-IR), nuclear magnetic resonance (H-NMR), gel permeation chromatograph (GPC), thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and universal tensile machine. The results show that the poly(succinic acid-1,4-Butanediol -urea ) copolymer was successfully synthesized, and the molecular weight of the copolymer can reach to 7.3104 with melting point of ~111.5℃ and decomposition temperature of ~380℃.The tensile strength of the copolymer film increases with the increase of urea content, but the value of elongation at break decreases. Hydrolytic degradation tests show that introduction of urea to modify PBS can improve the degradation properties of the copolymer.%在氩气环境下以丁二酸、1,4-丁二醇、尿素为原料,通过熔融缩聚、扩链反应合成新型可降解的丁二酸-丁二醇-尿素聚酯酰脲共聚物,并通过压延成膜法制得聚酯酰脲薄膜。采用傅里叶红外光谱(FT-IR)、核磁共振(1H-NMR)、凝胶色谱(GPC)、热重分析(TG)、差式扫描量热仪(DSC)、万能拉力机对聚合物及其薄膜结构及性能进行表征。结果表明:成功地合成了丁二酸-丁二醇-尿素聚酯酰脲共聚物,分子量可达7.3×104,熔点约为111.5℃,分解温度约为380℃。随着尿素含量的增加,共聚物薄膜拉伸强度增加,而断裂伸长率降低。经水解降解测试表明,引入尿素共聚改性PBS,可以提高共聚物的降解性能。

  3. pH值对Reppe法生产1,4-丁二醇加氢工艺的影响%Influence of pH Value on Hydrogenation Process for Producing 1, 4 - Butanediol with Reppe Method

    Institute of Scientific and Technical Information of China (English)

    李建立; 刘新波; 罗明周

    2012-01-01

    河南开祥精细化工有限公司4.5万t/a1,4-丁二醇装置采用Reppe法工艺技术。简述了该装置的加氢工艺流程和催化剂特性;建立了低压加氢反应器内物料的pH值与主产物BDO浓度以及产物中乙缩醛含量、羰基数、丁醇含量之间的关联曲线;确立了混合槽物料pH值(pH1)与低压加氢进料槽物料pH值(pH2)以及低压加氢反应器内物料pH值(pH3)三者之间的递减关系。研究结果表明:①将低压加氢反应器内物料pH值控制在7.0-7.5时,催化剂使用条件最佳,主产物BD0的含量最高,且各副产物浓度较低;②通过调整进料槽物料的pH值,可控制加氢反应器内物料的pH值。%The process technology with Reppe method has been adopted in the 1, 4 - Butanediol plant with a capacity of 45,000 t/a in Kaixiang Fine Chemistry Engineering Company Ltd. Author has briefly described the hydrogenation process flow and the characteristic of catalyst in this plant ; has established the relation curves among the medium pH value in low pressure hydrogenation reactor, BOD concentration of product, content of by-product acetal, carbonyl number and butanol content; has determined the progressively decreasing relation among the three parts of medium pH value (pHI) in mixing tank, medium pH value (pH2) in low pressure hydrogenation feed tank and medium value (pH3) in low pressure hydrogenation reactor. Researc- hing result indicates: (1) The operating condition is optimum, with a maximum content of the main products, and a lower concentration of every by-product, in case of tak- ing the medium pH value in low pressure hydrogenation reactor being controlled in 7.0-7.5. (2) The pH value of medium in Hydrogenation reactor can be controlled by means of controlling the pH value of medium in the feed tank.

  4. 微生物合成2,3-丁二醇的代谢工程%Metabolic engineering for efficient microbial production of 2,3-butanediol

    Institute of Scientific and Technical Information of China (English)

    童颖佳; 邬文嘉; 彭辉; 刘陆罡; 黄和; 纪晓俊

    2016-01-01

    2,3-butanediol (2,3-BD), which is considered as an important microbial metabolite, has been widely used in many fields such as food, medicine, chemical, and so on. Microbial 2,3-BD production has a history of more than 100 years, but the low efficiency of microbial 2,3-BD accumulation has constrained its process in biological manufacturing industrialization. Optimization of microbial metabolic pathway with the theory and method of metabolic engineering is expected to solve this problem. The objective of this paper is to review the state-of-the-art strain transformation and construction strategies in microbial synthesis of 2,3-BD, including overexpressing genes encoding for key enzymes in the 2,3-BD metabolic pathway, knocking out the metabolic bypass way genes, and using the methods of cofactor engineering in redesigning and reasonable transformation of the natural strains’ metabolic network. Besides that, the using of synthetic biology in constructing brand new 2,3-BD pathways in model strains, such as Escherichia coli, Saccharomyces cerevisiae and Cyanobacteria, in order to enhance the yield or chiral 2,3-BD production in microorganisms is also introduced in this review. Finally, the future research direction is prospected, and the guidelines to develop high-efficiency microbial cell factories by advanced synthetic biology methods to achieve the optimal allocation of the intracellular metabolic flow are also proposed.%2,3-丁二醇(2,3-BD)是一种重要的微生物代谢产物,广泛应用于食品、医药、化工等多个领域。微生物合成2,3-BD 的效率不高一直制约着其生物制造工业化进程,应用代谢工程的理论和方法优化微生物的代谢途径有望解决这一问题。本文全面总结了近年来微生物合成2,3-BD 研究过程中的菌株改造和构建技术,包括过表达合成途径中的关键酶编码基因、敲除旁路代谢途径关键酶编码基因、应用辅因子工程手段对天然菌株代谢

  5. 氧供应量对Klebsiella pneumoniae利用混合糖生物合成2,3-丁二醇过程的影响分析%Analysis of 2,3-butanediol production with Klebsiella pneumoniae using sugar mixture under different oxygen supply conditions

    Institute of Scientific and Technical Information of China (English)

    任彤; 张旭; 朱明龙

    2012-01-01

    以筛选的肺炎克雷伯氏菌(Klebsiella pneumoniae UV-86)为对象,考察供氧条件分别对菌体生长、葡萄糖和木糖双底物利用和产物合成的影响.研究发现生物量随氧供应量增加而增加.不同供氧条件对菌体消耗葡萄糖过程的影响较小,而代谢木糖的能力随氧供应量的增大而增强.微氧条件下2,3-丁二醇的生物合成能力最强,2,3-丁二醇产量在1.5 vvm下达到最高为30.1 g/L,是好氧时的2.5倍,最大体积产率为0.485 g/(L·h).不同条件下两底物产物分布有所区别,木糖代谢中乙酸生产增强.因此根据不同阶段代谢特点选择适合的供氧策略可以提高过程产量和产率.%The characteristics of cell growth, the metabolism of glucose and xylose and products formed by Klebsiella pneumoniae UV-86 (K. pneumoniae UV-86) under different oxygen supply conditions were investigated. The results showed that the cell mass increased with oxygen supply rates. The influence on the ability of glucose metabolism was not evident under different oxygen supply conditions. But the average specific xylose consumption rate was enhanced with increasing oxygen supply rates. The optimal production condition was under micro-aerobic condition. The maximum of 2, 3-butanediol concentration of 30.1 g/L was obtained at 1. 5 vvm and it was 2. 5 times the aerobic condition. The maximum productivity was 0.485 g/ (L·h). The distributions of products metabolized by glucose and xylose under different oxygen supply conditions were different. The production of acetate was enhanced in xylose metabolism. Therefore, it was necessary to choose suitable strategies to improve 2,3-butanediol concentration and productivity according to metabolic characteristics at different stages.

  6. Scientific Opinion on the safety evaluation of the active substances, terephthalic acid, dimethyl ester , polymer with 1,4-butanediol, cyclized, polymers with glycidyl methacrylate, hydroxyl-terminated polybutadiene, methyl methacrylate and styrene, and cobalt stearate for use in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2012-10-01

    Full Text Available

    This scientific opinion of EFSA deals with the safety evaluation of the oxygen absorber (terephthalic acid, dimethyl ester, polymer with 1,4-butanediol, cyclized, polymers with glycidyl methacrylate, hydroxyl-terminated polybutadiene, methyl methacrylate and styrene copolymer (CAS No 1223402-34-3, FCM substance No 1005 and the oxidation catalyst cobalt stearate (CAS No 1002-88-6 and FCM Substance No 1004, intended to be used up to a maximum percentage of 1% in polyethylene terephtalate (PET for absorbing oxygen from the food environment. All starting substances of the oxygen absorber formulation and cobalt stearate have been evaluated and approved for use as additives in plastic food contact materials. Methyl methacrylate, glycidyl methacrylate and cobalt stearate were not detected at the detection limits of 0.6, 0.006 and 0.0005 mg/kg food simulant, respectively. Butadiene was not detected in the PET bottles at a detection limit of 0.33 mg/kg plastic. For PET formulated with the maximum 1% of the active copoymer, the migration of the low molecular weight fraction (LMWF of the copolymer was estimated to be less than 35 µg/kg food. The CEF Panel concluded that the use of the copolymer up to 1% w/w in PET for contact with all types of foods at temperature up to 95°C and the use of cobalt stearate as oxidation catalyst in PET, is not of safety concern for the consumer.

  7. 聚(丁二酸丁二醇酯丁二酸环己烷二甲醇酯)的合成与表征%Synthesis and Characterization of Copolyesters of Succinic Acid-1,4-Butanediol/Succinic Acid-1,4-Cyclohexanedimethanol

    Institute of Scientific and Technical Information of China (English)

    余瑾; 程小苗; 周艺峰; 聂王焰

    2009-01-01

    用熔融缩聚法合成了一系列聚(丁二酸丁二醇酯丁二酸环己烷二甲醇酯)的无规共聚物.用FT-IR,~1H-NMR,DSC,TGA,XRD及水降解测试等方法表征了材料的结构与性能.通过DSC和TGA分析得到产物的熔点虽然较聚丁二酸丁二醇酯(PBS)有所降低,但是热分解温度却得到了提高;XRd测试结果表明,共聚物的晶体结构并没有发生改变;水降解测试结果表明,共聚物较PBS的降解速率有所提高.%A series of copolyesters of succinic acid-1,4-butanediol/succinic acid-1,4-cycl- ohexanedimethanol were synthesized and characterized by means of Fourier transform infrared spectroscopic(FT-IR), hydrogen nuclear magnetic resonance spectrum (~1H-NMR), differential scanning calorimetry ( DSC), thermogravimetry analysis (TGA), X-ray diffraction (XRD) and hydrolytic degradation. Though the melting temperature decreased, the copolymers showed the higher thermal decomposition temperature which was justified by TGA. X-ray diffraction shows that the crystal structure of copolymers is the same as poly (butylene succinate) (PBS). The results of hydrolytic degradation show that the rate of biodegradation of copolymers are higher than that of PBS.

  8. Enzymes related with NAD synthesis promote conversion of 1,4-butanediol to 4-hydroxybutyrate%烟酰胺腺嘌呤二核苷酸合成相关酶有助于1,4-丁二醇转化为4-羟基丁酸

    Institute of Scientific and Technical Information of China (English)

    张鑫; 陈国强

    2011-01-01

    Besides medical application, 4-hydroxybutyrate (4-HB) is a precursor of P3HB4HB, a bioplastic showing excellent physical properties and degradability. Escherichia coli S17-1 (pZL-dhaT-aldD) can transform 1, 4-butanediol (1,4-BD) into 4HB with participation of cofactor NAD. To enhance productivity, nicotinic acid phosphoribosyltransferase (PncB) and nicotinamide adenine dinucleotide synthetase (NadE) were overexpressed to increase intracellular nicotinamide adenine dinucleotide concentration and promote reaction process. The shake flask fermentation result showed that the conversion rate increased by 13.03% with help of PncB-NadE, leading to 4.87 g/L 4HB from 10 g/L 1,4-BD, and productivity was increased by 40.91% tol.86 g/g. These results demonstrated that expression of PncB and NadE is beneficial for conversion of 1,4-BD to 4HB.%4-羟基丁酸(4-HB)不仅具有医学应用价值,而且是合成生物材料P3HB4HB的重要前体.在烟酰胺腺嘌呤二核苷酸(NAD)参与情况下,大肠杆菌Escherichia coli S17-1(pZL-dhaT-aldD)可以把1,4-丁二醇(1,4-BD)转化为4HB.为提高4HB产率,通过过表达烟酸磷酸核糖转移酶(PncB)和烟酰胺腺嘌呤二核苷酸合成酶(NadE)增加胞内NAD含量,从而加速1,4-BD转化反应的进行.结果表明,PncB-NadE的表达使1,4-BD转化率比对照组增加13.03%,由10g/L的1,4-BD得到4.87 g/L的4HB,单位细胞的4HB产量由1.32 g/g提高40.91%至1.86 g/g.因此PncB和NadE可用于促进1,4-BD转化为4HB.

  9. Paenibacillus polymyxa ZJ-9混合发酵菊粉和葡萄糖合成R,R-2,3-丁二醇%Production of R,R-2,3-butanediol through mixed fermentation of inulin and glucose by Paenibacillus polymyxa ZJ-9

    Institute of Scientific and Technical Information of China (English)

    徐尤勇; 高健; 徐虹; 曹灿; 黄巍巍

    2015-01-01

    在7.5L发酵罐上考察了PaenibaciUus polymyxa ZJ-9混合发酵菊粉和葡萄糖合成R,R-2,3-丁二醇的工艺条件.选用菊芋菊粉粗提液为发酵前期底物,分析比较不同初始菊粉浓度下的细胞比生长速率(μ)和产物比合成速率(qp),进而研究了补糖种类和不同补料方式对合成R,R-2,3-丁二醇的影响.结果表明,初始菊粉75.0g/L,当发酵到24h、31 h时,分别添加15.0 g/L的葡萄糖,发酵效果最佳,44h时,产物产量达到最高值47.8 g/L,与分批发酵相比,糖转化率由原来的34.9%提高到45.5%,生产强度由原来的0.70 g/(L·h)提高到1.09 g/(L·h),并且副产物乙偶姻、残糖浓度相对较低.%Using 7.5 L fermentor,the conditions for mixed fermentation of inulin and glucose by Paenibacillus polymyxa Z J-9 to produce R,R-2,3-butanediol (R,R-2,3-BD) were discussed.The raw extract of inulin from Jerusalem artichoke tubers was used as the substrate for early fermentation.The specific cell growth rate (μ) and specific product formation rate (qp) under different initial concentrations of inulin were compared.Then,the influence of types of carbohydrate and feeding methods on the synthesis of R,R-2,3-BD was evaluated.The results showed that when the initial inulin concentration was 75.0 g/L and 15.0 g/L glucose was added at 24 h and 31 h,respectively,the optimal fermentation effect was achieved.The product yield reached the highest of 47.8 g/L at 44 h of fermentation.Compared with batch fermentation,the conversion rate of sugar (inulin and glucose) increased from 34.9% to 45.5%,and the productivity of R,R-2,3-BD increased from 0.70 g/(L · h) to 1.09 g/ (L · h).Furthermore,the concentrations of by-products such as acetoin and residual sugar were lowered.

  10. Genome Engineering of the 2,3-Butanediol Biosynthetic Pathway for Tight Regulation in Cyanobacteria.

    Science.gov (United States)

    Nozzi, Nicole E; Atsumi, Shota

    2015-11-20

    Cyanobacteria have gained popularity among the metabolic engineering community as a tractable photosynthetic host for renewable chemical production. However, though a number of successfully engineered production systems have been reported, long-term genetic stability remains an issue for cyanobacterial systems. The genetic engineering toolbox for cyanobacteria is largely lacking inducible systems for expression control. The characterization of tight regulation systems for use in cyanobacteria may help to alleviate this problem. In this work we explore the function of the IPTG inducible promoter P(L)lacO1 in the model cyanobacterium Synechococcus elongatus PCC 7942 as well as the effect of gene order within an operon on pathway expression. According to our experiments, P(L)lacO1 functions well as an inducible promoter in S. elongatus. Additionally, we found that gene order within an operon can strongly influence control of expression of each gene.

  11. Production of longer-chain alcohols from biomass - butanol, isopropanol and 2,3-butanediol

    NARCIS (Netherlands)

    Lopez Contreras, A.M.; Kuit, W.; Siemerink, M.A.J.; Kengen, S.W.M.; Springer, J.; Claassen, P.A.M.

    2010-01-01

    Bioethanol is one of the main biofuels capable of substituting petroleum usage in vehicles, and has had one of the largest impacts to date. The first generation of bioethanol production has had a worldwide impact, though it is restricted by energy intensive grain-to-bioethanol production technology,

  12. High Production of 2,3-Butanediol (2,3-BD) by Raoultella ornithinolytica B6 via Optimizing Fermentation Conditions and Overexpressing 2,3-BD Synthesis Genes

    Science.gov (United States)

    Kim, Taeyeon; Cho, Sukhyeong; Lee, Sun-Mi; Woo, Han Min; Lee, Jinwon; Seo, Jin-Ho

    2016-01-01

    Biological production of 2,3-butandiol (2,3-BD) has received great attention as an alternative to the petroleum-based 2,3-BD production. In this study, a high production of 2,3-BD in fed-batch fermentation was investigated with a newly isolated bacterium designated as Raoultella ornithinolytica B6. The isolate produced 2,3-BD as the main product using hexoses (glucose, galactose, and fructose), pentose (xylose) and disaccharide (sucrose). The effects of temperature, pH-control schemes, and agitation speeds on 2,3-BD production were explored to optimize the fermentation conditions. Notably, cell growth and 2,3-BD production by R. ornithinolytica B6 were higher at 25°C than at 30°C. When three pH control schemes (no pH control, pH control at 7, and pH control at 5.5 after the pH was decreased to 5.5 during fermentation) were tested, the best 2,3-BD titer and productivity along with reduced by-product formation were achieved with pH control at 5.5. Among different agitation speeds (300, 400, and 500 rpm), the optimum agitation speed was 400 rpm with 2,3-BD titer of 68.27 g/L, but acetic acid was accumulated up to 23.32 g/L. Further enhancement of the 2,3-BD titer (112.19 g/L), yield (0.38 g/g), and productivity (1.35 g/L/h) as well as a significant reduction of acetic acid accumulation (9.71 g/L) was achieved by the overexpression of homologous budABC genes, the 2,3-BD-synthesis genes involved in the conversion of pyruvate to 2,3-BD. This is the first report presenting a high 2,3-BD production by R.ornithinolytica which has attracted little attention with respect to 2,3-BD production, extending the microbial spectrum of 2,3-BD producers. PMID:27760200

  13. Combining metabolic engineering and biocompatible chemistry for high-yield production of homo-diacetyl and homo-(S,S)-2,3-butanediol

    DEFF Research Database (Denmark)

    Liu, Jianming; Chan, Siu Hung Joshua; Brock-Nannestad, Theis;

    2016-01-01

    Biocompatible chemistry is gaining increasing attention because of its potential within biotechnology for expanding the repertoire of biological transformations carried out by enzymes. Here we demonstrate how biocompatible chemistry can be used for synthesizing valuable compounds as well...... as for linking metabolic pathways to achieve redox balance and rescued growth. By comprehensive rerouting of metabolism, activation of respiration, and finally metal ion catalysis, we successfully managed to convert the homolactic bacterium Lactococcus lactis into a homo-diacetyl producer with high titer (95m...... of 82%. The diacetyl and S-BDO production rates and yields obtained are the highest ever reported, demonstrating the promising combination of metabolic engineering and biocompatible chemistry as well as the great potential of L. lactis as a new production platform....

  14. Comparison of 2,3-Butanediol Production by Two Klebsiella pneumoniae Strains%两株Klebsiella pneumoniae菌发酵生产2,3-丁二醇的比较

    Institute of Scientific and Technical Information of China (English)

    孙丽慧; 戴建英; 王旭东; 修志龙

    2010-01-01

    对两株克雷伯氏菌(Klebsiella pneumoniae)批式流加发酵生产2,3-丁二醇进行了研究,结果表明,K.pneumoniae CICC 10011代谢产生的各种有机酸和乙醇浓度均明显低于K.pneumoniae DSM 2026,发酵56 h,目标产物(2,3-丁二醇+乙偶姻)浓度为85.61 g/L,生产强度为1.53 g/(L·b),葡萄糖质量转化率为45%.对2株克雷伯氏菌发酵的代谢流量分析表明,K.pneumoniae CICC 10011是生产2,3-丁二醇的优良菌株.

  15. The catalyst and production process of methyl ethyl ketone by the dehydration of 2,3-butanediol%2,3-丁二醇气相脱水制备甲乙酮用催化剂及其工艺研究

    Institute of Scientific and Technical Information of China (English)

    王文革; 吴彦彬; 杨理; 宋国全; 闫广学; 吴正岭

    2016-01-01

    采用固定床反应器,以2,3-丁二醇为原料,在超强固体酸催化剂作用下,气相催化脱水制备甲乙酮.研究了反应温度、液时空速和氮醇物质量的比(N2流量)等因素对合成反应的影响.在反应温度290~305℃,液时空速0.5~3.0h-1,氮醇物质量的比26~30的条件下,2,3-丁二醇转化率达95%以上,甲乙酮选择性达92%以上.

  16. 生物降解聚丁二酸丁二醇/1,3-丙二醇酯的合成与表征%Synthesis and Characterization of Biodegradable Copolyester (Succinic Acid-1,4-Butanediol-1,3-Propanediol)

    Institute of Scientific and Technical Information of China (English)

    刘亦武; 王倩; 谭井华; 向贤伟; 刘跃军

    2014-01-01

    以丁二酸、丁二醇和1,3-丙二醇(1,3-PDO)为原料,采用熔融缩聚法,合成了一系列新型可降解的聚丁二酸丁二醇酯/丁二酸1,3-丙二醇酯共聚物P(BS-co-PDO).选用红外光谱仪和核磁共振仪对共聚物的化学结构进行了表征.研究了1,3-PDO的添加量对共聚物的相对分子质量、热性能、结晶性能、力学性能、透光率以及降解性能的影响.结果表明:随着1,3-PDO添加量的增加,共聚物的分子量、熔点和结晶度呈降低趋势;相对于聚丁二酸丁二醇酯而言,引入1,3-PDO组分的共聚物的热性能提高,柔韧性增强,断裂伸长率增大,透光率提高;降解测试结果表明,1,3-PDO组分含量越多,共聚物的降解性能越好.

  17. Study on production of 2,3-butanediol from straw paper pulp hydrolysate fermentation by Klebsiella pneumoniae%Klebsiella pneumoniae发酵稻草纸浆水解液生产2,3-丁二醇工艺的研究

    Institute of Scientific and Technical Information of China (English)

    杨洋; 张玉苍; 孙岩峰; 何连芳; 姜杨

    2010-01-01

    对Klebsiella pneumoniae发酵稻草纸浆水解液生产2,3-丁二醇的工艺进行了初步的实验研究.考察了温度、时间、底物浓度、pH等不同因素对稻草纸浆酶水解和2,3-丁二醇发酵的影响.结果表明,在纸浆的酶用量为135 IU/g、底物浓度为20g/L、50℃、pH4.8的条件下反应20 h,还原糖得率最高为68.15%;2,3-丁二醇的最佳发酵条件为pH 6.0、葡萄糖仞始浓度100 g/L、30 ℃、接种量15%、150 r/min、反应72 h,2,3-丁二醇的最高转化率为17.92%.

  18. Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources : Enzymatic Synthesis, Characterization, and Properties

    NARCIS (Netherlands)

    Jiang, Yi; Alberda van Ekenstein, Gerhard; Woortman, Albert J. J.; Loos, Katja

    2014-01-01

    Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)-catalyzed polycondensations of succinate, itaconate, and 1,4-butanediol. The effects of monomer substrates and polymerization methods on enzymatic polycondens

  19. Modification of Metal Complex on the Stereoselective Hydrogenation of 2,3-Butanedione

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The modification of some metal complexes on Pt/Al2O3 clusters leads to remarkable increases in both the activity and the selectivity for meso-2,3-butanediol in the stereoselective hydrogenation of 2,3-butanedione.

  20. Preparation of a removable polyurethane encapsulant

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.G.

    1976-08-01

    The preparation of polyurethane encapsulants, based on polyether diol/diisocyanate prepolymers and 1,4-butanediol, which are soluble in several organic solvents, was investigated. Since these materials can be easily removed, repair of electronic circuitry found defective in potted units can be readily accomplished. Polyether diols of varying molecular weights were reacted with toluene diisocyanate (TDI) and methylene diphenylisocyanate (MDI) to produce stable prepolymers. Several properties of both the isocyanate prepolymers and 1,4-butanediol cured polyurethane encapsulants are presented.

  1. Study on multimers and their structures in molecular association mixture

    Institute of Scientific and Technical Information of China (English)

    NI Yi; DOU XiaoMing; ZHAO HaiYing; YIN GuangZhong; YAMAGUCHI Yoshinori; OZAKI Yukihiro

    2007-01-01

    Self-association system of (R)-1,3-butanediol in dilute carbon tetrachloride (CCl4) solution is studied as a model of molecular association mixture. Analysis methods including FSMWEFA (fixed-size moving window evolving factor analysis) combined with PCA (principal component analysis), SIMPLISMA (simple-to-use interactive self-modeling mixture analysis), and ITTFA (iterative target transformation factor analysis) are adopted to resolve infrared spectra of (R)-1,3-butanediol solution. Association number and equilibrium constant are computed. (R)-1,3-butanediol in dilute inert solution is determined as a monomer-trimer equilibrium system. Theoretical investigation of trimer structures is carried out with DFT (density functional theory), and structural factors are analyzed.

  2. The 3-hydroxy-2-butanone pathway is required for Pectobacterium carotovorum pathogenesis.

    Directory of Open Access Journals (Sweden)

    Maria del Pilar Marquez-Villavicencio

    Full Text Available Pectobacterium species are necrotrophic bacterial pathogens that cause soft rot diseases in potatoes and several other crops worldwide. Gene expression data identified Pectobacterium carotovorum subsp. carotovorum budB, which encodes the α-acetolactate synthase enzyme in the 2,3-butanediol pathway, as more highly expressed in potato tubers than potato stems. This pathway is of interest because volatiles produced by the 2,3-butanediol pathway have been shown to act as plant growth promoting molecules, insect attractants, and, in other bacterial species, affect virulence and fitness. Disruption of the 2,3-butanediol pathway reduced virulence of P. c. subsp. carotovorum WPP14 on potato tubers and impaired alkalinization of growth medium and potato tubers under anaerobic conditions. Alkalinization of the milieu via this pathway may aid in plant cell maceration since Pectobacterium pectate lyases are most active at alkaline pH.

  3. Study on multimers and their structures in molecular association mixture

    Institute of Scientific and Technical Information of China (English)

    YAMAGUCHI; Yoshinori; OZAKI; Yukihiro

    2007-01-01

    Self-association system of(R)-1,3-butanediol in dilute carbon tetrachloride(CCl4)solution is studied as a model of molecular association mixture.Analysis methods including FSMWEFA(fixed-size moving window evolving factor analysis)combined with PCA(principal component analysis),SIMPLISMA (simple-to-use interactive self-modeling mixture analysis),and ITTFA(iterative target transformation factor analysis)are adopted to resolve infrared spectra of(R)-1,3-butanediol solution.Association number and equilibrium constant are computed.(R)-1,3-butanediol in dilute inert solution is determined as a monomer-trimer equilibrium system.Theoretical investigation of trimer structures is carried out with DFT(density functional theory),and structural factors are analyzed.

  4. Laser spectroscopy and mass spectrometry of biologically relevant systems: chiral discrimination

    Science.gov (United States)

    Piccirillo, Susanna; Satta, Mauro; Coreno, Marcello; Catone, Daniele; Rondino, Flaminia; Scuderi, Debora; Paladini, Alessandra; Speranza, Maurizio; Giardini, Anna

    2005-06-01

    Radical ions are open-shell elusive species of paramount importance in many organic reactions and in biological processes. Oxidative bond breaking and forming involving radical ions are common process taking place in asymmetric enzyme cavities. Side-chain Cα-CΒ bond fragmentation in the radical cations of aromatic alcohols is a common process in solution [1-3], whose efficiency is enhanced in polar solvents such as water. Hydrogen-bonding between the ion and the solvent in the relevant transition structure is thought as responsible of the rate acceleration [4]. Effects of achiral and chiral microsolvation on the radical cation of R-(+)-l-phenyl-l-propanol, have been investigated. The energy thresholds of the homolytic Cα-Cβ bond breaking of R-(+)-1-phenyl-1-propanol radical cation, its mono-hydrated cluster, and its clusters with (2R,3R)-(-)-2,3-butanediol and (2S,3S)-(+)-2,3-butanediol have been studied through two color Resonant Two Photon Ionization, Photodissociation and Mass Spectrometry. The barrier of the Cα-Cβ fragmentation is appreciably higher for the unsolvated molecular ion than for its adducts with solvent molecules. Moreover, marked differences in the ethyl loss fragmentation energy are observed for the clusters with water and with the two diols. In particular the homochiral cluster with (2R, 3R)-(-)-2,3-butanediol exhibits a fragmentation barrier higher than that of the corresponding heterochiral adduct with (25, 35)-(+)-2,3-butanediol.

  5. Quantitative estimation of the strength of specific interactions in polyurethane elastomers, and their effect on structure and properties

    NARCIS (Netherlands)

    Bagdi, K.; Molnar, K.; Kallay, M.; Schön, P.M.; Vancso, G.J.; Pukanszky, B.

    2012-01-01

    Two sets of segmented polyurethane (PU) elastomers were prepared from crystalline MDI, butanediol and a polyester or a polyether polyol, respectively. The molar mass of both polyols was 1000 g/mol. The –OH functional group ratio of polyol/total diol was kept constant at a value of 0.4, while the rat

  6. Comparison of different busulfan analogues for depletion of hematopoietic stem cells and promotion of donor-type chimerism in murine bone marrow transplant recipients

    NARCIS (Netherlands)

    Westerhof, GR; Ploemacher, RE; Boudewijn, A; Blokland, [No Value; Dillingh, JH; McGown, AT; Hadfield, JA; Dawson, MJ; Down, JD

    2000-01-01

    Busulfan (1,4-butanediol dimethanesulfonate, BU) is relatively unique among other standard chemotherapy compounds in its ability to deplete noncycling primitive stem cells in the host and consequently to allow for high levels of long-term, donor-type engraftment after bone marrow transplantation (BM

  7. Comparison of different busulfan analogues for depletion of hematopoietic stem cells and promotion of donor-type chimerism in murine bone marrow transplant recipients

    NARCIS (Netherlands)

    G.R. Westerhof; R.E. Ploemacher (Robert); A. Boudewijn (Adrie); I. Blokland (Irene); J.H. Dillingh; A.T. McGown; J.A. Hadfield; M.J. Dawson; J.D. Down

    2000-01-01

    textabstractBusulfan (1,4-butanediol dimethanesulfonate, BU) is relatively unique among other standard chemotherapy compounds in its ability to deplete noncycling primitive stem cells in the host and consequently to allow for high levels of long-term, donor-type engraft

  8. Synthesis and Characterisation of Bis-(chloromethyl Oxetane, its Homopolymer and Copolymer with Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    T. S. Reddy

    2006-07-01

    Full Text Available Bis-(chloromethyl oxetane (BCMO was synthesised from pentaerythritol by chlorination,followed by ring closure. It was polymerised using BF3-etherate and butanediol system, similarlythe BCMO–THF (tetrahydrofuran copolymer was also synthesised. The monomers and thepolymers were characterised by IR, 1H-NMR and molecular weight. Flame retardant propertiesof the poly-BCMO were also investigated.

  9. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    NARCIS (Netherlands)

    Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetrame

  10. Co- and Terpolyesters based on isosorbide and succinic acid for coating applications : synthesis and characterization

    NARCIS (Netherlands)

    Noordover, B.A.J.; Staalduinen, van V.G.; Duchateau, R.; Koning, C.E.; Benthem, van R.A.T.M.; Mak, M.; Heise, A.; Frissen, A.E.; Haveren, van J.

    2006-01-01

    Co- and terpolyesters based on succinic acid and isosorbide in combination with other renewable monomers such as 2,3-butanediol, 1,3-propanediol, and citric acid were synthesized and characterized. Linear polyesters were obtained via melt polycondensation of nonactivated dicarboxylic acids with OH f

  11. 40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

    Science.gov (United States)

    2010-07-01

    .../Dehydrogenation of 1,4-butanediol Caprolactam/From cyclohexane via cyclohexanone and its oxime Lilian..., Oxo process Cyclohexanone/From phenol via cyclohexanol by hydrogenation-dehydrogenation Fatty amines.../Oxidation of cyclohexanol-cyclohexanone mixture Adipic acid/Oxidation of cyclohexane via...

  12. Possibility of diacetyl and related compounds as the 4-carbon compound necessary for the formation of riboflavin in Ashbya gossypii.

    Science.gov (United States)

    Nakajima, K; Mitsuda, H

    1984-01-01

    The effects of various compounds (0.5%) involved in the butanediol and the glycolytic pathways on riboflavin formation in whole cells of Ashbya gossypii at rest were examined. The addition of acetate, glycerol and diacetyl inhibited riboflavin formation, while the addition of acetoin had no effect on it, and the addition of ethanol, 2,3-butanediol, pyruvic acid and glucose accelerated it. The relation of diacetyl and acetoin to riboflavin formation during resting cell incubation in the presence of 0.5% ethanol and various concentrations of 2,3-butanediol was examined. The results quantitatively revealed a precursor-product relation between riboflavin formation and the formation of diacetyl and acetoin. The results obtained provide evidence that a high flavinogenic agent, ethanol, was converted to acetaldehyde, pyruvic acid, acetoin and diacetyl in this order, that a week flavinogenic agent, 2,3-butanediol, was transferred to diacetyl through acetoin, and that the diacetyl produced can be utilized as the 4-carbon compound for riboflavin formation in the flavinogenic mold, Ashbya gossypii. It remains obscure whether diacetyl is enzymatically involved in riboflavin formation. PMID:6534171

  13. Interesting Starter Culture Strains for Controlled Cocoa Bean Fermentation Revealed by Simulated Cocoa Pulp Fermentations of Cocoa-Specific Lactic Acid Bacteria ▿

    OpenAIRE

    Lefeber, Timothy; Janssens, Maarten; Moens, Frédéric; Gobert, William; De Vuyst, Luc

    2011-01-01

    Among various lactic acid bacterial strains tested, cocoa-specific strains of Lactobacillus fermentum were best adapted to the cocoa pulp ecosystem. They fermented glucose to lactic acid and acetic acid, reduced fructose to mannitol, and converted citric acid into lactic acid and 2,3-butanediol.

  14. 尿素共聚改性聚己二酸丁二醇酯及其性能%Properties of PBA Modified by Copolymerization with Urea

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 谢伟; 刘亦武; 范淑红; 刘磅

    2013-01-01

    An adipic acid-1,4-butanediol copolymer (PBA) was synthesized by esterification reaction using adipic acid and 1, 4-butanediol as the raw materials. Then, using PBA and urea as reactive materials, a biodegradable polyester, adipic acid 1, 4-butanediol urea copolymer, was synthesized by high-temperature melt polycondensation. The influences of urea on the copolymer thermostability, crystallization, water absorption and degradation properties were investigated. The structure and properties of the copolymer were characterized by Fourier transform infrared (FT-IR), 1H-NMR spectrum, gel permeation chromatography (GPC), thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The results show that with the proper molar ratio ( n (1,4-butanediol and urea)/n (adipic acid) = 1.16:1, and n(1,4-butanediol)/n(urea) =5:1), the weight average molecular weight (-Mw) of adipic acid 1,4- butanediol urea copolymer was approximately 1×104. Compared with PBA, the thermal stability, water absorption and degradation performance of this copolymer are improved significantly.%以己二酸和1,4-丁二醇为原料,通过酯化反应合成了聚己二酸丁二醇酯(PBA),再用尿素与其通过高温熔融缩聚反应合成了己二酸-丁二醇-尿素共聚物.考察了尿素含量对共聚物热稳定性、结晶性能、吸水率和降解性能的影响.利用红外光谱(IR)、核磁共振谱(NMR)、凝胶渗透色谱(GPC)、热重分析(TG)和差示扫描量热分析(DSC)对聚合物进行了表征.结果表明,当丁二醇和尿素总量与己二酸的物质的量比n(丁二醇+尿素)∶n(己二酸)为1.16∶1,丁二醇和尿素的物质的量比n(1,4-丁二醇)∶n(尿素)为5∶1时,共聚物的重均分子量(-Mw)约为1×104,对比PBA,共聚物的热稳定性、吸水率和降解性能等有明显的提高.

  15. 基于生物质资源的化工多元醇生物炼制研究进展%Recent progress of biorefinery of polyols based on biomass resources

    Institute of Scientific and Technical Information of China (English)

    马翠卿; 李理想; 高超

    2013-01-01

    介绍了2,3-丁二醇、1,2-丙二醇和木糖醇等多元醇的主要用途及市场需求,从生产菌株、生产原料、生产方式等方面综述了国内基于生物质资源的2,3-丁二醇、1,2-丙二醇和木糖醇生物炼制的研究进展.%The main use and market demands of 2, 3-butanediol, 1, 2-propanediol and xylitol were presented. The recent development in biorefinery production of 2, 3-butanediol, 1, 2-propanediol and xylitol was summarized, including the producing strains, raw materials, and producing method.

  16. Effects of introducing heterologous pathways on microbial metabolism with respect to metabolic optimality

    DEFF Research Database (Denmark)

    Kim, Hyun Uk; Kim, Byoungjin; Seung, Do Young;

    2014-01-01

    reactions are more frequently introduced into various microbial hosts. The genome-scale metabolic simulations of Escherichia coli strains engineered to produce 1,4-butanediol, 1,3-propanediol, and amorphadiene suggest that microbial metabolism shows much different responses to the introduced heterologous......Although optimality of microbial metabolism under genetic and environmental perturbations is well studied, the effects of introducing heterologous reactions on the overall metabolism are not well understood. This point is important in the field of metabolic engineering because heterologous...... reactions in a strain-specific manner than typical gene knockouts in terms of the energetic status (e.g., ATP and biomass generation) and chemical production capacity. The 1,4-butanediol and 1,3-propanediol producers showed greater metabolic optimality than the wild-type strains and gene knockout mutants...

  17. Preparation and Properties of HBS Lignin from Masson Pine

    Institute of Scientific and Technical Information of China (English)

    CHENG Xian-su; CHEN Wei-jian; CHEN Yun-ping; CHEN Yue-xian; LI Mian-jun; FANG Hua-shu

    2004-01-01

    In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent (HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%-90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200-220 ℃ for 60-180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent (RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.

  18. Influence of fermentation by-products on the purification of ethanol from water using pervaporation.

    Science.gov (United States)

    Chovau, S; Gaykawad, S; Straathof, A J J; Van der Bruggen, B

    2011-01-01

    Pervaporation is claimed to be a promising separation technique for the purification of ethanol from fermentation broths during bio-ethanol production. In this study, influence of fermentation by-products on the purification of ethanol from water during hydrophobic pervaporation was investigated. Sugars and salts were found to increase the membrane performance. Reason for this was a change in vapor/liquid equilibrium. 2,3-butanediol decreased the ethanol flux and selectivity factor, while glycerol exhibited no effect. This was explained by a strong sorption of butanediol into PDMS and no sorption of glycerol. Due to the presence of carboxylic acids, hydrophobicity degree of the Pervap 4060 membrane decreased, which resulted in an irreversible increase in water flux and decrease in separation performance. These observations suggested the presence of silicalite-based fillers in the membrane. When the pH was raised to a value above the dissociation constant, no changes in hydrophobicity degree and membrane performance were found.

  19. Imperium/Lanzatech Syngas Fermentation Project - Biomass Gasification and Syngas Conditioning for Fermentation Evaluation: Cooperative Research and Development Final Report, CRADA Number CRD-12-474

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, E.

    2014-09-01

    LanzaTech and NREL will investigate the integration between biomass gasification and LanzaTech's proprietary gas fermentation process to produce ethanol and 2,3-butanediol. Using three feed materials (woody biomass, agricultural residue and herbaceous grass) NREL will produce syngas via steam indirect gasification and syngas conditioning over a range of process relevant operating conditions. The gasification temperature, steam-to-biomass ratio of the biomass feed into the gasifier, and several levels of syngas conditioning (based on temperature) will be varied to produce multiple syngas streams that will be fed directly to 10 liter seed fermenters operating with the Lanzatech organism. The NREL gasification system will then be integrated with LanzaTech's laboratory pilot unit to produce large-scale samples of ethanol and 2,3-butanediol for conversion to fuels and chemicals.

  20. Biotechnology for producing fuels and chemicals from biomass. Volume 2: Fermentation chemicals from biomass

    Science.gov (United States)

    Villet, R.

    1981-02-01

    The technological and economic feasibility of producing chemicals by fermentation is discussed: acetone; butanol; acetic acid; citric acid; 2,3-butanediol, and propionic acid. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5 percent to 7 percent/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. The feedstock cost is 15 to 20 percent of the overall cost of production. The anticipated 5 percent growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. The commercial fermentative production of propionic acid has not yet been developed.

  1. Devising efficient biotechnological processes for the production of fuels and chemicals from biomass

    Science.gov (United States)

    Villet, R. H.

    1982-05-01

    Research directed toward improving ethanol processes based on readily fermentable feedstocks is discussed. Efforts were also made to develop novel fermentation systems. Reducing the cost of producing ethanol and other chemicals requires using cellulosics as feedstocks, which when hydrolyzed form hexose sugars readily metabolized by yeast. A program was undertaken to discover thermophilic organisms that convert various biopolymers to ethanol and other chemical products. Lipids suitable as diesel oil extenders are produced by microorganisms. A screening program was undertaken to identify microbial strains with a biotechnological potential. This involved a precise, quantitative chemical analysis of lipid products. Some work on developing a 2,3-butanediol fermentation process is described. During the fermentation process ethanol is also produced. To improve the ratio of butanediol to ethanol, a program of genetic and physiological research was designed and initiated.

  2. A NEW METHOD FOR MAKING CELLULOSE AND LIGNIN FROM BAMBOO BY HIGH BOILING SOLVENT

    Institute of Scientific and Technical Information of China (English)

    XiansuCHENG; WeijianCHEN; YunpingCHEN; HuashuFANG; MianjunLI; YuexianCHEN

    2004-01-01

    In order to establish a new method for making cellulose and lignin from bamboo, a high boiling solvent (HBS) pulping process with aqueous solvcnt of 1,4-butanediol was investigated. Bamboo chips were pulped with 70~90% aqueous solution of 1. 4-butanediol containing a small amount of catalyst at 180~200℃ for 30~90 min. HBS bamboo cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. Recovery high boiling solvents (RHBS) is able to recycle as a pulping solvent indicating that the HBS method is a pulping process of bamboo with saving energy, saving resources and non-pollution. HBS lignin has better chemical activity and lower ash content than lignin sulfonate.

  3. A NEW METHOD FOR MAKING CELLULOSE AND LIGNIN FROM BAMBOO BY HIGH BOILING SOLVENT

    Institute of Scientific and Technical Information of China (English)

    Xiansu CHENG; Weijian CHEN; Yunping CHEN; Huashu FANG; Mianjun LI; Yuexian CHEN

    2004-01-01

    In order to establish a new method for making cellulose and lignin from bamboo, a high boiling solvent (HBS) pulping process with aqueous solvent of 1,4-butanediol was investigated. Bamboo chips were pulped with 70~90% aqueous solution of 1,4-butanediol containing a small amount of catalyst at 180~200℃ for 30-90 min.. HBS bamboo cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. Recovery high boiling solvents (RHBS) is able to recycle as a pulping solvent indicating that the HBS method is a pulping process of bamboo with saving energy, saving resources and non-pollution. HBS lignin has better chemical activity and lower ash content than lignin sulfonate.

  4. Effect of heat treatments on the luminescence properties of Zn{sub 2}SiO{sub 4}:Mn{sup 2+} phosphors prepared by glycothermal methods

    Energy Technology Data Exchange (ETDEWEB)

    Uegaito, Keisuke; Hosokawa, Saburo [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510 (Japan); Inoue, Masashi, E-mail: inoue@scl.kyoto-u.ac.jp [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510 (Japan)

    2012-01-15

    Manganese-doped Zn{sub 2}SiO{sub 4} phosphors with different crystal structures and morphologies were synthesized by glycothermal reactions of zinc acetate dihydrate and manganese(II) acetate tetrahydrate with tetraethyl orthosilicate in various glycols at 315 deg. C. The reactions in 1,3-propanediol and 1,4-butanediol yielded {alpha}-Zn{sub 2}SiO{sub 4}:Mn{sup 2+}, whereas the reactions in ethylene glycol and 1,5-pentanediol yielded {beta}-Zn{sub 2}SiO{sub 4}:Mn{sup 2+} and ZnO, respectively. The samples obtained in 1,4-butanediol and 1,3-propanediol emitted green light (522 nm), and the sample prepared in 1,4-butanediol showed a higher emission intensity. The photoluminescence intensity of the Zn{sub 1.96}Mn{sub 0.04}SiO{sub 4} phosphor prepared by a glycothermal reaction in 1,4-butanediol and subsequently calcined at 1100 deg. C was twice as high as that of the sample synthesized by a conventional solid-state reaction. The high emission efficiency was obtained because the highly homogeneous distribution of Mn{sup 2+} in the {alpha}-Zn{sub 2}SiO{sub 4} host synthesized by the glycothermal reaction was maintained during calcination treatment in air. - Highlights: > Glycothermal synthesis of {alpha}-Zn{sub 2}SiO{sub 4}:Mn{sup 2+}. > High photoluminescence property of {alpha}-Zn{sub 2}SiO{sub 4}:Mn{sup 2+} prepared by glycothermal method. > XANES characterization of Mn species in {alpha}-Zn{sub 2}SiO{sub 4} calcined at various temperatures. > Highly homogeneous distribution of Mn{sup 2+} in the {alpha}-Zn{sub 2}SiO{sub 4} host.

  5. Effect of heat treatments on the luminescence properties of Zn2SiO4:Mn2+ phosphors prepared by glycothermal methods

    International Nuclear Information System (INIS)

    Manganese-doped Zn2SiO4 phosphors with different crystal structures and morphologies were synthesized by glycothermal reactions of zinc acetate dihydrate and manganese(II) acetate tetrahydrate with tetraethyl orthosilicate in various glycols at 315 deg. C. The reactions in 1,3-propanediol and 1,4-butanediol yielded α-Zn2SiO4:Mn2+, whereas the reactions in ethylene glycol and 1,5-pentanediol yielded β-Zn2SiO4:Mn2+ and ZnO, respectively. The samples obtained in 1,4-butanediol and 1,3-propanediol emitted green light (522 nm), and the sample prepared in 1,4-butanediol showed a higher emission intensity. The photoluminescence intensity of the Zn1.96Mn0.04SiO4 phosphor prepared by a glycothermal reaction in 1,4-butanediol and subsequently calcined at 1100 deg. C was twice as high as that of the sample synthesized by a conventional solid-state reaction. The high emission efficiency was obtained because the highly homogeneous distribution of Mn2+ in the α-Zn2SiO4 host synthesized by the glycothermal reaction was maintained during calcination treatment in air. - Highlights: → Glycothermal synthesis of α-Zn2SiO4:Mn2+. → High photoluminescence property of α-Zn2SiO4:Mn2+ prepared by glycothermal method. → XANES characterization of Mn species in α-Zn2SiO4 calcined at various temperatures. → Highly homogeneous distribution of Mn2+ in the α-Zn2SiO4 host.

  6. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese

    Science.gov (United States)

    Martino, Gabriela P.; Quintana, Ingrid M.; Espariz, Martín; Blancato, Victor S.; Gallina Nizo, Gabriel; Esteban, Luis

    2016-01-01

    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  7. Tetrahydrofuran Unit Adopting Davy's Latest Maleic Anhydride Technology to Come Online

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The 1,4-butanediol (BDO)/tetrahydrofuran (THF) project constructed by the Blue Star (Nanjing) New Chemical Ma-terials Co., Ltd. adopting a whole package of the world's latest patented technology will come on-stream by the end of 2008. It is told that by that time Blue Star will rank among the global leaders in terms of quality of BDO and THF products, which can substitute for around 40% of imported high-quality products.

  8. Preparation of Monolithic Column and Its Application in p-CEC

    Institute of Scientific and Technical Information of China (English)

    Jun Jiao YANG; Kai ZHANG; Ru Yu GAO; Yu Kui ZHANG; Chao YAN

    2004-01-01

    A novel monolithic stationary phase having long alkyl chain ligands was introduced and evaluated in pressurized-capillary electrochromatography of small neutral and charged compounds.The monolithic column was prepared by the in situ copolymerization of ethylene dimethacrylate,1-hexadecene,allyl alcohol and 2-acrylamido-2-methyl-1-propanesulfonic acid in a quaternary porogenic solvent mixture consisting of 1,4-butanediol,cyclohexanol,dodecanol and water.

  9. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement

    OpenAIRE

    Brochu, Alice B. W.; Chyan, William J.; Reichert, William M

    2012-01-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thicknes...

  10. Stone Comminution Correlates with the Average Peak Pressure Incident on a Stone during Shock Wave Lithotripsy

    OpenAIRE

    Smith, N; P Zhong

    2012-01-01

    To investigate the roles of lithotripter shock wave (LSW) parameters and cavitation in stone comminution, a series of in vitro fragmentation experiments have been conducted in water and 1,3-butanediol (a cavitation-suppressive fluid) at a variety of acoustic field positions of an electromagnetic shock wave lithotripter. Using field mapping data and integrated parameters averaged over a circular stone holder area (Rh = 7 mm), close logarithmic correlations between the average peak pressure (P+...

  11. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    OpenAIRE

    Scholten, Elke; Bromberg, Lev E.; Rutledge, Gregory C.; Hatton, T. Alan

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetramethylene glycol as the soft segments were electrospun from their solutions in N,N-dimethylformamide to form micrometer-sized fibers. Although activated carbon possessed a many-fold higher surface ar...

  12. Characterization of Volatile Components in Makgeolli, a Traditional Korean Rice Wine, with or without Pasteurization, During Storage

    OpenAIRE

    Sang Hoon Song; Young-Suk Kim; Sang Mi Lee; Hye-Jung Park

    2013-01-01

    Changes in the volatile components of unpasteurized and pasteurized makgeolli during 30 days of storage were investigated by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O). A total of 11 odor-active compounds such as 3-methyl-1-butanol (isoamyl alcohol), 2-methyl-1-butanol, 2,3-butanediol, butanoic acid, 3-methylbutanoic acid (isovaleric acid), 2-methylbutanoic acid, 3-(methylthio)-1-propanol (methionol), 2-phenylethanol, ethyl decanoate, ethyl dodecanoate, and ethyl ...

  13. Strategies for enhancing fermentative production of acetoin: a review.

    Science.gov (United States)

    Xiao, Zijun; Lu, Jian R

    2014-01-01

    Acetoin is a volatile compound widely used in foods, cigarettes, cosmetics, detergents, chemical synthesis, plant growth promoters and biological pest controls. It works largely as flavour and fragrance. Since some bacteria were found to be capable of vigorous acetoin biosynthesis from versatile renewable biomass, acetoin, like its reduced form 2,3-butanediol, was also classified as a promising bio-based platform chemical. In spite of several reviews on the biological production of 2,3-butanediol, little has concentrated on acetoin. The two analogous compounds are present in the same acetoin (or 2,3-butanediol) pathway, but their production processes including optimal strains, substrates, derivatives, process controls and product recovery methods are quite different. In this review, the usages of acetoin are reviewed firstly to demonstrate its importance. The biosynthesis pathway and molecular regulation mechanisms are then outlined to depict the principal network of functioning in typical species. A phylogenetic tree is constructed and the relationship between taxonomy and acetoin producing ability is revealed for the first time, which will serve as a useful guide for the screening of competitive acetoin producers. Genetic engineering, medium optimization, and process control are effective strategies to improve productivity as well. Currently, downstream processing is one of the main barriers in efficient and economical industrial acetoin fermentation. The future prospects of microbial acetoin production are discussed in light of the current progress, challenges, and trends in this field. PMID:24412764

  14. Biofuel and chemical production by recombinant microorganisms via fermentation of proteinaceous biomass

    Energy Technology Data Exchange (ETDEWEB)

    Liao, James C.; Cho, Kwang Myung; Yan, Yajun; Huo, Yixin

    2016-03-15

    Provided herein are metabolically modified microorganisms characterized by having an increased keto-acid flux when compared with the wild-type organism and comprising at least one polynucleotide encoding an enzyme that when expressed results in the production of a greater quantity of a chemical product when compared with the wild-type organism. The recombinant microorganisms are useful for producing a large number of chemical compositions from various nitrogen containing biomass compositions and other carbon sources. More specifically, provided herein are methods of producing alcohols, acetaldehyde, acetate, isobutyraldehyde, isobutyric acid, n-butyraldehyde, n-butyric acid, 2-methyl-1-butyraldehyde, 2-methyl-1-butyric acid, 3-methyl-1-butyraldehyde, 3-methyl-1-butyric acid, ammonia, ammonium, amino acids, 2,3-butanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 2-methyl-1,4-butanediamine, isobutene, itaconate, acetoin, acetone, isobutene, 1,5-diaminopentane, L-lactic acid, D-lactic acid, shikimic acid, mevalonate, polyhydroxybutyrate (PHB), isoprenoids, fatty acids, homoalanine, 4-aminobutyric acid (GABA), succinic acid, malic acid, citric acid, adipic acid, p-hydroxy-cinnamic acid, tetrahydrofuran, 3-methyl-tetrahydrofuran, gamma-butyrolactone, pyrrolidinone, n-methylpyrrolidone, aspartic acid, lysine, cadeverine, 2-ketoadipic acid, and/or S-adenosyl-methionine (SAM) from a suitable nitrogen rich biomass.

  15. Polyurethane-maleamides for cardiovascular applications: synthesis and properties.

    Science.gov (United States)

    Petrini, P; De Ponti, S; Farè, S; Tanzi, M C

    1999-12-01

    Several polyurethane-maleamides (PUMAs) containing polyether or polycarbonate soft segments, and aromatic or aliphatic hard segments were synthesized by solution or bulk polymerization, using maleic acid (MA) or a mixture of MA and butanediol as chain extenders. Using this process, activated double bonds are introduced into the polymer chains and the base polyurethanes may undergo further modification via specific grafting, thus improving their tissue compatibility. PUMAs chemicophysical properties were evaluated by gel permeation chromatography (GPC), intrinsic viscosity analyses, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and tensile mechanical tests. Polycarbonate diol (PCU)-based PUMAs showed higher molecular weights than polyether diol (PEU)-based ones. The use of butanediol in mixture with maleic acid led to an increase of molecular weights. FT-IR confirmed the presence of the bands related to the amide groups and to the conjugated double bond, yet more evident for the polymer obtained in solution. The higher crystallinity shown by this polymer was also indicative of a better phase separation. All the PCU-PUMAs exhibited similar tensile properties with a higher stiffness than PEU-PUMAs. Among the PEU-PUMAs, the highest tensile properties were shown by the polymer obtained in solution, and by the one derived from a mixture of maleic acid and butanediol.

  16. Effects of budC gene knockout and ldhA overexpression on D-lactic acid production by Klebsiella pneumoniae%budC敲除及ldhA过表达对Klebsiella pneumoniae合成D-乳酸的影响

    Institute of Scientific and Technical Information of China (English)

    王凤寰; 孟青青

    2012-01-01

    为了提高K.pneumoniae中D-乳酸的合成效率,本文以BUD和LDH为改造目标,扩增丁二醇脱氢酶基因budC,并在其中插入四环素抗性基因tet,构建了基因敲除载体pTBT,转化K.pneumoniae,利用同源重组技术,敲除K.pneumoniae染色体上的budC基因,得到重组菌K.pneumoniae B-;在此基础上,构建了表达载体pKP-ldhA,转化K.pneumoniae B-,过量表达乳酸脱氢酶基因ldhA,得到重组菌Kpneumoniae B-L+.摇瓶发酵结果显示,重组菌K.pneumoniae B-L+的丁二醇合成浓度比原始菌降低了90%以上,D-乳酸合成浓度比K.pneumoniae B-和原始菌分别提高了77.1%和41.4%,发酵罐实验D-乳酸产量68.4 g/L,转化率0.78,生产强度1.22 g/(L·h).结果表明,敲除budC及过表达ldhA有利于改善克雷伯肺炎杆菌中D-乳酸的合成.%In the metabolic pathway of Klebsiella pneumoniae, 2,3-butanediol is a byproduct and its accumulation decreases the yield of main product, D-lactic acid. Butanediol dehydrogenase (BUD) is one of the key enzymes for butanediol biosynthesis, which competes with lactate dehydrogenase (LDH) for reducing equivalents of nicotinam-ide adenine dinueleotide (NADH). In order to reduce the butanediol accumulation and improve the D-lactic acid production, in this study, a homologous recombination vector pTBT was constructed and transformed into K. pneumoniae, resulting in K. pneumoniae B-, in which the budC gene encoding butanediol dehydrogenase was disrupted by inserting a tetracycline resistant gene (tet). Simultaneously, the expression vector pKP-ldhA harboring the ldhA gene was constructed and transformed into K. pneumoniae B- to overexpress lactate dehydrogenase. The resulting recombinant strain K. pneumoniae B-L + exhibited a nearly abolished butanediol formation ( decreased by 90% ) but a significantly improved NADH availability and D-lactic acid production. In flask culture, the D-lactic acid concentrations were 77. 1% and 41.4% , respectively, higher than those of

  17. The genome of Pelobacter carbinolicus reveals surprising metabolic capabilities and physiological features

    Energy Technology Data Exchange (ETDEWEB)

    Aklujkar, Muktak [University of Massachusetts, Amherst; Haveman, Shelley [University of Massachusetts, Amherst; DiDonatoJr., Raymond [University of Massachusetts, Amherst; Chertkov, Olga [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL; Brown, Peter [University of Massachusetts, Amherst; Lovley, Derek [University of Massachusetts, Amherst

    2012-01-01

    Background: The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species. Results: Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their structural properties and genomic contexts. The absence of asparagine synthetase and the presence of a mutant tRNA for asparagine encoded among RNA-active enzymes suggest that P. carbinolicus may make asparaginyl-tRNA in a novel way. Catabolic glutamate dehydrogenases were discovered, implying that the tricarboxylic acid (TCA) cycle can function catabolically. A phosphotransferase system for uptake of sugars was discovered, along with enzymes that function in 2,3-butanediol production. Pyruvate: ferredoxin/flavodoxin oxidoreductase was identified as a potential bottleneck in both the supply of oxaloacetate for oxidation of acetate by the TCA cycle and the connection of glycolysis to production of ethanol. The P. carbinolicus genome was found to encode autotransporters and various appendages, including three proteins with similarity to the geopilin of electroconductive nanowires. Conclusions: Several surprising metabolic capabilities and physiological features were predicted from the genome of P. carbinolicus, suggesting that it is more versatile than anticipated.

  18. Pareto Optimal Design for Synthetic Biology.

    Science.gov (United States)

    Patanè, Andrea; Santoro, Andrea; Costanza, Jole; Carapezza, Giovanni; Nicosia, Giuseppe

    2015-08-01

    Recent advances in synthetic biology call for robust, flexible and efficient in silico optimization methodologies. We present a Pareto design approach for the bi-level optimization problem associated to the overproduction of specific metabolites in Escherichia coli. Our method efficiently explores the high dimensional genetic manipulation space, finding a number of trade-offs between synthetic and biological objectives, hence furnishing a deeper biological insight to the addressed problem and important results for industrial purposes. We demonstrate the computational capabilities of our Pareto-oriented approach comparing it with state-of-the-art heuristics in the overproduction problems of i) 1,4-butanediol, ii) myristoyl-CoA, i ii) malonyl-CoA , iv) acetate and v) succinate. We show that our algorithms are able to gracefully adapt and scale to more complex models and more biologically-relevant simulations of the genetic manipulations allowed. The Results obtained for 1,4-butanediol overproduction significantly outperform results previously obtained, in terms of 1,4-butanediol to biomass formation ratio and knock-out costs. In particular overproduction percentage is of +662.7%, from 1.425 mmolh⁻¹gDW⁻¹ (wild type) to 10.869 mmolh⁻¹gDW⁻¹, with a knockout cost of 6. Whereas, Pareto-optimal designs we have found in fatty acid optimizations strictly dominate the ones obtained by the other methodologies, e.g., biomass and myristoyl-CoA exportation improvement of +21.43% (0.17 h⁻¹) and +5.19% (1.62 mmolh⁻¹gDW⁻¹), respectively. Furthermore CPU time required by our heuristic approach is more than halved. Finally we implement pathway oriented sensitivity analysis, epsilon-dominance analysis and robustness analysis to enhance our biological understanding of the problem and to improve the optimization algorithm capabilities.

  19. The genome of Pelobacter carbinolicus reveals surprising metabolic capabilities and physiological features

    Directory of Open Access Journals (Sweden)

    Aklujkar Muktak

    2012-12-01

    Full Text Available Abstract Background The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species. Results Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their structural properties and genomic contexts. The absence of asparagine synthetase and the presence of a mutant tRNA for asparagine encoded among RNA-active enzymes suggest that P. carbinolicus may make asparaginyl-tRNA in a novel way. Catabolic glutamate dehydrogenases were discovered, implying that the tricarboxylic acid (TCA cycle can function catabolically. A phosphotransferase system for uptake of sugars was discovered, along with enzymes that function in 2,3-butanediol production. Pyruvate:ferredoxin/flavodoxin oxidoreductase was identified as a potential bottleneck in both the supply of oxaloacetate for oxidation of acetate by the TCA cycle and the connection of glycolysis to production of ethanol. The P. carbinolicus genome was found to encode autotransporters and various appendages, including three proteins with similarity to the geopilin of electroconductive nanowires. Conclusions Several surprising metabolic capabilities and physiological features were predicted from the genome of P. carbinolicus, suggesting that it is more versatile than anticipated.

  20. Preparation of films of a highly aligned lipid cubic phase

    OpenAIRE

    Squires, Adam; Hallett, J.E.; Beddoes, C. M.; Plivelic, T. S.; Seddon, A. M.

    2013-01-01

    We demonstrate a method by which we can produce an oriented film of an inverse bicontinuous cubic phase (QII D) formed by the lipid monoolein (MO). By starting with the lipid as a disordered precursor (the L3 phase) in the presence of butanediol, we can obtain a film of the QII D phase showing a high degree of in-plane orientation by controlled dilution of the sample under shear within a linear flow cell. We demonstrate that the direction of orientation of the film is different from that foun...

  1. A NOVEL METHOD TO PREPARE CROSSLINKED POLYETHYLENEIMINE HOLLOW NANOSPHERES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel method to prepare crosslinked polyethyleneimine (CPEI) hollow nanospheres was reported.Uniform silica nanospheres were used as templates,3-aminopropyl trimethoxysilane (APS) was immobilized on the surface of silica nanospheres as couple agent.Aziridine was initiated ring-opening polymerization with the amino groups in APS to form polyethyleneimine (PEI) shell layer.1,4-Butanediol diacrylate was utilized to crosslink PEI polymeric shell.The silica nanospheres in core were etched by hydrofluoric acid to obtain hollow CPEI nanospheres.The hollow nanospheres were characterized by X-ray photoelectron spectroscopy (XPS),transmission electron microscopy (TEM),and thermogravimetric analysis (TGA).

  2. Preparation of polyacrylamide based monolith with immobilized pH gradient and its application for protein analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic materials were prepared in capillaries by in situ polymerization of acrylamide, glycidyl methacrylate and N,N′-memylenebisacrylamid in the presence of trinary porogens, including 1,4-butanediol, dodecanol and dimethyl sulphoxide. With Ampholine immobilized on the monolith by chemical bonding according to their pIs, the monolithic immobilized pH gradient (M-IPG) was prepared, and applied to the separation of four standard proteins. Compared with polyacrylate based M-IPG, the hydrophilicity of the new material was improved. It could not only avoid the adsorption of proteins, but also make the synthesized procedure simple, which showed great potential in the analysis of proteins.

  3. Draft Genome Sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a Citrate-Fermenting Strain

    Science.gov (United States)

    Zuljan, Federico; Espariz, Martín; Blancato, Victor S.; Esteban, Luis; Alarcón, Sergio

    2016-01-01

    We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains. PMID:26847906

  4. Structural changes in amorphous organic compounds and their role during chemical transformations

    International Nuclear Information System (INIS)

    Using butanediol vinylacetate and dimetacrylate as an example, it can be shown that structural changes of amorphous-liquid substance play an important part at chemical transformations of amorphous compounds and chemical reaction rate provides an function of local order. When the amorphous polymer is viewed as an system of multiple transformations, each gives birth to the definite local order, the calculation of recombination reaction of active centers accumulated during irradiation of polymer at 77 K is carried out. Concentration of recombinated centers rises steeply near each transformation Tk

  5. Evaluation of level of impregnation monomers in hydrotalcite

    International Nuclear Information System (INIS)

    To evaluate the impregnation degree of 1,6-hexamethylene diisocyanate and 1,4-butanediol monomers in hydrotalcite clays it was prepared dispersions with mixing ratio 1:100 (clay/monomer), using the Ultraturrax and Ultrasound. Subsequently the samples were characterized by Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Swelling tests and Tyndall effect were used to illustrate the different dispersions. The results indicated a strong interaction between the hydrotalcite with 1,6-hexamethylene diisocyanate, favoring the formation of intercalated structures. (author)

  6. Evaluation of level of impregnation monomers in hydrotalcite; Avaliacao do grau de impregnacao de monomeros em hidrotalcita

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Danieli M. do, E-mail: danielimcarmo@hotmail.com [Instituto de Macromoleculas Professora Eloisa Mano - IMA, Universidade Federal do Rio de Janeiro - UFRJ, RJ (Brazil); Machado, Jacson S.C.; Oliveira, Marcelo F.L.; Oliveira, Marcia G. [Instituto Nacional de Tecnologia - INT, Rio de Janeiro, RJ (Brazil); Soares, Bluma G. [Instituto de Macromoleculas Professora Eloisa Mano - IMA, Universidade Federal do Rio de Janeiro - UFRJ, RJ (Brazil)

    2011-07-01

    To evaluate the impregnation degree of 1,6-hexamethylene diisocyanate and 1,4-butanediol monomers in hydrotalcite clays it was prepared dispersions with mixing ratio 1:100 (clay/monomer), using the Ultraturrax and Ultrasound. Subsequently the samples were characterized by Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Swelling tests and Tyndall effect were used to illustrate the different dispersions. The results indicated a strong interaction between the hydrotalcite with 1,6-hexamethylene diisocyanate, favoring the formation of intercalated structures. (author)

  7. Systems strategies for developing industrial microbial strains

    DEFF Research Database (Denmark)

    Lee, Sang Yup; Kim, Hyun Uk

    2015-01-01

    Industrial strain development requires system-wide engineering and optimization of cellular metabolism while considering industrially relevant fermentation and recovery processes. It can be conceptualized as several strategies, which may be implemented in an iterative fashion and in different ord...... achievements in recent years include microbial production of amino acids (L-valine, L-threonine, L-lysine and L-arginine), bulk chemicals (1,4-butanediol, 1,4-diaminobutane, 1,5-diaminopentane, 1,3-propanediol, butanol, isobutanol and succinic acid) and drugs (artemisinin)....

  8. SYNTHESIS AND CHARACTERIZATION OF Si-CONTAINING POLYESTER-POLYETHER MULTIBLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    LI Zhenyi; ZHU Jin

    1996-01-01

    A series of Si-containing polyester-polyether multiblock copolymers were synthesized by transesterification and melt copolycondensation of organosilicon monomers [1, 1, 3, 3-tetramethyl-1, 3-bis (p-carbomethoxyphenyl) disiloxane] (I) or dimethyl bis (p-carbomethoxyphenyl) silane] (II) and dimethyl terephthalate (DMT), with 1, 4-butanediol, polytetramethylene glycol (PTMG) respectively. The organosilicon monomers were prepared by Grinard reaction, oxidation and esterification. The structures of the above monomers (Ⅰ), (Ⅱ) and the copolymers were characterized by MS anal. and 1H-NMR.

  9. Preparation of polyacrylamide based monolith with immobilized pH gradient and its application for protein analysis

    Institute of Scientific and Technical Information of China (English)

    ZHU GuiJie; ZHANG WeiBing; ZHANG LiHua; LIANG Zhen; ZHANG YuKui

    2007-01-01

    Monolithic materials were prepared in capillaries by in situ polymerization of acrylamide, glycidyl methacrylate and N,N'-memylenebisacrylamid in the presence of trinary porogens, including 1,4-butanediol, dodecanol and dimethyl sulphoxide. With Ampholine immobilized on the monolith by chemical bonding according to their pIs, the monolithic immobilized pH gradient (M-IPG) was prepared, and applied to the separation of four standard proteins. Compared with polyacrylate based M-IPG, the hydrophilicity of the new material was improved. It could not only avoid the adsorption of proteins, but also make the synthesized procedure simple, which showed great potential in the analysis of proteins.

  10. Comparison between properties of polyurethane nano composites prepared by two different methods

    International Nuclear Information System (INIS)

    In this work, a thermoplastic polyurethane elastomer model based on polytetramethylene glycol. toluene diisocyanate and 1,4-butanediol was selected and synthesized. According to this model two types of polyurethane nano composites were prepared by in situ polymerization and melt intercalation procedures. The organo-modified nano clay was used in nano composites samples in 0.4 weight percent level. The prepared nano composites were studied by WAXD, tensile and thermal analysis. Thermal properties of the nano composites were higher than those of pure polyurethane elastomers. Nano composites prepared via melt intercalation method showed a lower tensile strength and hardness than those prepared through in situ polymerization method

  11. Synthesis and characterization of biodegradable polyurethane based on poly(ε-caprolactone) and L-lysine ethyl ester diisocyanate

    Institute of Scientific and Technical Information of China (English)

    Jian HAN; Bing CHEN; Lin YE; Ai-ying ZHANG; Jian ZHANG; Zeng-guo FENG

    2009-01-01

    A biocompatible diisocyanate, lysine ethyl ester diisocyanate, was prepared. Afterwards, biodegra-dable polyurethane (PU) was synthesized by the step-growth polymerization of this diisocyanate with hydroxyl terminated poly(ε-caprolactone) in the presence of 1,4-butanediol as a chain-extender. The resulting PU was characterized by GPC, IR and DSC measurements. Its mechanical strength was found to increase with increasing the hard segment content. The PU microfiber meshes with high porosity were obtained by solution electrospinning technique. Their degradation behavior in the PBS and enzymatic solution was also investigated.

  12. Mesoporous tertiary oxides via a novel amphiphilic approach

    Directory of Open Access Journals (Sweden)

    Natasha Bennett

    2016-01-01

    Full Text Available We report a facile biomimetic sol-gel synthesis using the sponge phase formed by the lipid monoolein as a structure-directing template, resulting in high phase purity, mesoporous dysprosium- and gadolinium titanates. The stability of monoolein in a 1,4-butanediol and water mixture complements the use of a simple sol-gel metal oxide synthesis route. By judicious control of the lipid/solvent concentration, the sponge phase of monoolein can be directly realised in the pyrochlore material, leading to a porous metal oxide network with an average pore diameter of 10 nm.

  13. Mesoporous tertiary oxides via a novel amphiphilic approach

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Natasha; Hall, Simon R., E-mail: simon.hall@bristol.ac.uk, E-mail: Annela.Seddon@bristol.ac.uk [Bristol Centre for Functional Nanomaterials, Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol BS8 1FD, United Kingdom and Complex Functional Materials Group, School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Seddon, Annela M., E-mail: simon.hall@bristol.ac.uk, E-mail: Annela.Seddon@bristol.ac.uk; Hallett, James E. [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Kockelmann, Winfried [STFC Rutherford Appleton Laboratory, Chilton OX11 0QX (United Kingdom); Ting, Valeska P. [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom); Sadasivan, Sajanikumari; Tooze, Robert P. [Sasol Technology (UK) Ltd, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST (United Kingdom)

    2016-01-01

    We report a facile biomimetic sol-gel synthesis using the sponge phase formed by the lipid monoolein as a structure-directing template, resulting in high phase purity, mesoporous dysprosium- and gadolinium titanates. The stability of monoolein in a 1,4-butanediol and water mixture complements the use of a simple sol-gel metal oxide synthesis route. By judicious control of the lipid/solvent concentration, the sponge phase of monoolein can be directly realised in the pyrochlore material, leading to a porous metal oxide network with an average pore diameter of 10 nm.

  14. Variations in Volatile Compounds in Bergamot during Curing%佛手挥发性物质在腌制过程中的变化

    Institute of Scientific and Technical Information of China (English)

    严赞开; 严奉伟

    2012-01-01

    以佛手鲜果及其腌制品为原料,通过超声波辅助水蒸气蒸馏技术,提取鲜佛手及其腌制品的挥发性物质,运用气相色谱-质谱联用技术对挥发性物质进行分析。结果表明:两种佛手挥发性物质提取率分别为0.76%和0.32%;新鲜佛手挥发性物质鉴定出31种化合物,其中以(Z)-2,3-丁二醇、(E)-2,3-丁二醇、D-柠檬烯、松油烯、α-松油醇、橙花醇、反式香叶醇等为主;在腌制过程中,不饱和烯烃类化合物损失较大,含量明显下降,其中有6种未检出;但糖类发酵导致(Z)-2,3-丁二醇、(E)-2,3-丁二醇的含量明显增加,这是佛手腌制后具有浓郁香甜风味的原因。%The volatile compositions of fresh and cured bergamot were analyzed by ultrasonic-assisted steam distillation coupled with GC-MS.The extraction rates of essential oil from fresh and cured bergamot were 0.76% and 0.32%,respectively.A total of 31 compounds were identified from fresh bergamot and(Z)-2,3-butanediol,(E)-2,3-butanediol,D-limomene,terpinene,αterpineol,neroli and trans-geraniol were predominant among them.During the process of curing,the loss of unsaturated alkenes was remarkable,and 6 unsaturated alkenes showed undetectable levels.However,the contents of(Z)-2,3-butanediol and(E)-2,3butanediol showed a notable increase as a result of carbohydrate fermentation,which was responsible for the strong sweet flavor of cured bergamot.

  15. Synthesis and stereochemistry of 6-membered ring phosphonates

    Directory of Open Access Journals (Sweden)

    Michael D. Pungente

    2012-03-01

    Full Text Available Background: Organophosphorus compounds have important industrial and biomedical applications as pharmaceutical and agrochemical agents, as well as transition state analogs for the production of monoclonal antibodies. Methods: Two diastereomers of a 6-membered ring, cyclic phenyl phosphonate were synthesized in 8 steps from 1,3-butanediol. Results: The stereochemistry of the diastereomers was elucidated on the basis of H NMR nuclear Overhauser effects (NOE difference experiments. Conclusions: Such cyclic phosphonates may have utility serving as transition state analogs for the production of monoclonal antibodies.

  16. Draft Genome Sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a Citrate-Fermenting Strain.

    Science.gov (United States)

    Zuljan, Federico; Espariz, Martín; Blancato, Victor S; Esteban, Luis; Alarcón, Sergio; Magni, Christian

    2016-01-01

    We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains. PMID:26847906

  17. Visualization study of the shrinkage void distribution in thermal energy storage capsules of different geometry

    Energy Technology Data Exchange (ETDEWEB)

    Revankar, Shripad T. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Croy, Travis [INEEL, Idaho Falls, ID 83404-5558 (United States)

    2007-01-15

    The presence of concentrated shrinkage voids in thermal energy storage systems employing encapsulated phase change material can cause serious problems when one attempts to melt the solidified phase change material for the next thermal cycle. Experiments were performed and void-formation phenomena with rectangular flat plate, spherical, and torus shape capsules were investigated. The initial void growth, distribution and the total void in the capsule were photographically studied from transparent capsules using cyclohexane, hexadecane, butanediol and octadecane as phase change materials. The observations on freezing process and the shrinkage void distribution are presented. (author)

  18. Migration of additives from poly(vinyl chloride) (PVC) tubes into aqueous media

    DEFF Research Database (Denmark)

    Wang, Qian; Storm, Birgit Kjærside

    2005-01-01

    The stability and migration product of medical PVC tubes plasticized with polyadipates were investigated by ageing in phosphate buffer at pH 1.679 and water at different temperatures. Changes in the PVC tubes were studied by wtaer absorption, weight loss, Fourier infrared spectroscopy (FTIR...... from PVC matrix occurred. When the tube was aged at 110 C, significant degradation of both polyadipates and PVC were observed. Adipic acid and 1,4-butanediol monomers and oligomers of polyadipate were the major migration products from polyadipates in the water ageing solution, while only a relatively...

  19. SYNTHESIS OF MESOGENIC POLYESTERS WITH 2-DICHLOROMETHYLHYDROQUINONE MOIETIES

    Institute of Scientific and Technical Information of China (English)

    Zhou Qifeng; Guo Ailan

    1995-01-01

    A series of novel mesogenic polyesters with 2-dichloromethylhydroquinone moieties were synthesized by polycondensation of the novel diacyl chloride monomer 2-dichloromethyl-1,4-bis (4'-chloroformylbenzoyl) oxybenzene(Ⅰ) with α, ω-polymethylenediols including ethylene glycol, 1,4-butanediol, 1,6-hexanediol and 1,10-decanediol. The diacyl chloride monomer was synthesized by simultaneous transformations of both the carboxy and formaldehyde groups of 2-formyl-1, 4-bis (4'-carboxybenzoyl)oxybenzene into acyl chloride and dichloromethyl groups respectively. The syntheses of the monomer (Ⅰ) and the polymers were reported.

  20. A FOURIER TRANSFORM INFRARED SPECTROSCOPIC STUDY OF THE REACTION BETWEEN POLY (VINYL PYRIDINE)S AND EPOXY COMPOUNDS

    Institute of Scientific and Technical Information of China (English)

    XUE Gi; JIANG Shankeng

    1987-01-01

    Chemical reactions between poly (vinyl pyridine)s and 1,4-butanediol diglycidyl ether and other epoxy compounds were studied by Fouriertransform infrared spectroscopy and other techniques. The epoxy group was found to react with the pyridine side group of poly (4-vinyl pyridine), forming crosslinked networks which contain cyclic amide structures. The reaction was also observed in the interfacial region of poly(vinyl pyridine) and γ-glycidoxy propyl trimethoxysilane hydrolyzate (γ-GPS) coatings on PET fiber substrates.Poly(2-vinyl pyridine) does not show the same reaction.

  1. Sorption and selective chromatographic properties of isomer-selective composite sorbent based on a eutectic mixture of nematic liquid crystals and perbenzoylated β-cyclodextrin

    Science.gov (United States)

    Onuchak, L. A.; Kapralova, T. S.; Kuraeva, Yu. G.; Belousova, Z. P.; Stepanova, R. F.

    2015-12-01

    Mesomorphic, sorption, and selective properties of a three-component sorbent based on a mixture of nematic ( N) liquid crystals of 4-methoxy-4'-ethoxyazoxybenzene (MEAB) and 4,4'-diethoxyazoxybenzene (azoxyphenetol, AOP) of an eutectic composition and heptakis-(2,3,6-tri- O-benzoyl)-β-cyclodextrin (Bz-β-CD) are studied. For 30 organic compounds of different classes with linear and cyclic molecular structures, including optical isomers of limonene, pinene, camphene, and butanediol-2,3, thermodynamic functions are determined for their gas-phase sorption using a three-component MEAB-AOP-Bz-β- CD sorbent (62: 28: 10 wt %). It is found that the investigated sorbent possesses high structural selectivity (αp/m = 1.128-1.059, 100-130°C, N) and moderate enantioselectivity (1.07-1.02) within a broad temperature range (95-170°C) including both mesomorphic and isotropic phases of the sorbent. It is shown that the enantioselectivity of the sorbent is apparent under conditions of both increasing retention when a chiral Bz-β-CD additive is introduced into the MEAB-AOP system (limonenes, pinenes, camphenes) and decreasing retention (butanediols-2,3).

  2. Fundamental studies for microbial enhanced oil recovery field test; Biseibutsu koho (MEOR) fuirudo tesuto no tameno kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, H. [Tohoku Univ., Sendai (Japan). Dept. of Geoscience and Tech.; Fujiwara, K. [Kansai Research Inst., Kyoto (Japan). Lefescience Research Center; Yonebayashi, H. [Japan National Oil Corp., Tokyo (Japan). Tech. Research Center

    2000-03-01

    This paper describes a series of experiments relevant to the screening of microbes to adapt and monitor the targeted microbes in the microbial enhanced oil recovery (MEOR) process. Firstly, the samples of reservoir brine, soil of well site, drilling cuttings, and activated sludge were collected from domestic oil fields, drilling sites, sewage treatment facilities, and environmental conditions. To achieve higher oil recovery, metabolic products of isolates were individually evaluated. These isolates were also incubated in culture bottles packed with silica sands, to clarify the growth potential and metabolic activity in the micro culture space. By carrying out two stages of flooding experiments simulating the reservoir environment, the capability of isolates for improving oil recovery was evaluated, and the microbes were selected. Two gene-engineering techniques were established in parallel with the screening experiments for monitoring the microbes injected into the reservoir. These techniques are potentially capable of rapidly detecting the presence of injecting microbes; moreover, they are available and effective for studying the microbes relevant to the MEOR process. In addition, it was demonstrated that metabolic activity of the microbes capable of producing effective gas could be estimated based on the quantity of 2,3-butanediol found as a major end product of fermentation. The results of the huff and puff field test implied that the gene-engineering techniques established in this study and the metabolic activity analysis on 2,3-butanediol were effective for understanding the growth and metabolic activity of the microbes injected into the reservoir. (author)

  3. PREPARATION OF EVOH MICROPOROUS MEMBRANES via THERMALLY INDUCED PHASE SEPARATION USING BINARY SOLVENTS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Microporous ethylene-vinyl alcohol copolymer (EVOH) flat membranes and hollow-fiber membranes with 38 mol% ethylene content were prepared via thermally induced phase separation (TIPS) using the mixture of 1,4-butanediol and poly(ethylene glycol)(PEG400) as diluents. Effects of the ratio of 1,4-butanediol to PEG400 on the phase diagrams, phase separation mechanism and membrane morphology were studied by small angle light scattering (SALS) measurements, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). It was found that by varying the composition of the binary solvent, the phase diagrams and membrane morphology can be controlled successfully. Moreover, the phase diagrams showed that broader regions of Liquid-Liquid (L-L) phase separation were obtained, as well as closer distances between L-L phase separation lines and Solid-Liquid (S-L) phase separation lines. Interconnected structures observed both in the flat membrane and hollow fiber membrane consist with the above results.

  4. Microwave-assisted on-spot derivatization for gas chromatography-mass spectrometry based determination of polar low molecular weight compounds in dried blood spots.

    Science.gov (United States)

    Sadones, Nele; Van Bever, Elien; Archer, John R H; Wood, David M; Dargan, Paul I; Van Bortel, Luc; Lambert, Willy E; Stove, Christophe P

    2016-09-23

    Dried blood spot (DBS) sampling and analysis is increasingly being applied in bioanalysis. Although the use of DBS has many advantages, it is also associated with some challenges. E.g. given the limited amount of available material, highly sensitive detection techniques are often required to attain sufficient sensitivity. In gas chromatography coupled to mass spectrometry (GC-MS), derivatization can be helpful to achieve adequate sensitivity. Because this additional sample preparation step is considered as time-consuming, we introduce a new derivatization procedure, i.e. "microwave-assisted on-spot derivatization", to minimize sample preparation of DBS. In this approach the derivatization reagents are directly applied onto the DBS and derivatization takes place in a microwave instead of via conventional heating. In this manuscript we evaluated the applicability of this new concept of derivatization for the determination of two polar low molecular weight molecules, gamma-hydroxybutyric acid (GHB) and gabapentin, in DBS using a standard GC-MS configuration. The method was successfully validated for both compounds, with imprecision and bias values within acceptance criteria (weight compounds of interest in clinical and/or forensic toxicology, including vigabatrin, beta-hydroxybutyric acid, propylene glycol, diethylene glycol, 1,4-butanediol and 1,2-butanediol, can also be detected using this method. PMID:27578413

  5. Performance of supercritical methanol in polyurethane degradation

    Directory of Open Access Journals (Sweden)

    Liu Lu

    2016-01-01

    Full Text Available Polyurethane is a group of block copolymer which is composed of diisocyanate, chain extender, and polyol, including polyurethane foam, polyurethane elastomer, waterborne polyurethane, etc. This research focused on thermoplastic polyurethane elastomer (TPU which is formed with 4,4’-diphenylmethane diisocyanate (MDI, poly(1,4-butanediol-hexanedioic acid diolpolyester(PBA and extended with 1,4-butanediol(BDO.The degradation of TPU was carried out with the help of methanol as the supercritical solvent. The SEM of the reaction residues revealed the process of the depolymerisation. The products were measured by GC-MS and found out to be PBA, BDO and 4,4’-methylene diphenyl carbamate(MDC which is themethylate of MDI.GC-FID, HPLC-UV and GPC were used to further analysis. The experimental results showed that supercritical methanol performed outstandingly in TPU recycling, it needed lower temperature and shorter time than regular methods. At 230°C/70min, over 90% raw materials of TPU could be recovered.

  6. Biotechnology for producing fuels and chemicals from biomass. Volume II. Fermentation chemicals from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Villet, R. (ed.)

    1981-02-01

    The technological and economic feasibility of producing some selected chemicals by fermentation is discussed: acetone, butanol, acetic acid, citric acid, 2,3-butanediol, and propionic acid. The demand for acetone and butanol has grown considerably. They have not been produced fermentatively for three decades, but instead by the oxo and aldol processes. Improved cost of fermentative production will hinge on improving yields and using cellulosic feedstocks. The market for acetic acid is likely to grow 5% to 7%/yr. A potential process for production is the fermentation of hydrolyzed cellulosic material to ethanol followed by chemical conversion to acetic acid. For about 50 years fermentation has been the chief process for citric acid production. The feedstock cost is 15% to 20% of the overall cost of production. The anticipated 5%/yr growth in demand for citric acid could be enhanced by using it to displace phosphates in detergent manufacture. A number of useful chemicals can be derived from 2,3-butanediol, which has not been produced commercially on a large scale. R and D are needed to establish a viable commercial process. The commercial fermentative production of propionic acid has not yet been developed. Recovery and purification of the product require considerable improvement. Other chemicals such as lactic acid, isopropanol, maleic anhydride, fumarate, and glycerol merit evaluation for commercial fermentative production in the near future.

  7. Single-walled carbon nanotube-based polymer monoliths for the enantioselective nano-liquid chromatographic separation of racemic pharmaceuticals.

    Science.gov (United States)

    Ahmed, Marwa; Yajadda, Mir Massoud Aghili; Han, Zhao Jun; Su, Dawei; Wang, Guoxiu; Ostrikov, Kostya Ken; Ghanem, Ashraf

    2014-09-19

    Single-walled carbon nanotubes were encapsulated into different polymer-based monolithic backbones. The polymer monoliths were prepared via the copolymerization of 20% monomers, glycidyl methacrylate, 20% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) or 16.4% monomers (16% butyl methacrylate, 0.4% sulfopropyl methacrylate), 23.6% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) along with 6% single-walled carbon nanotubes aqueous suspension. The effect of single-walled carbon nanotubes on the chiral separation of twelve classes of pharmaceutical racemates namely; α- and β-blockers, antiinflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs and antiarrhythmic drugs was investigated. The enantioselective separation was carried out under multimodal elution to explore the chiral recognition capabilities of single-walled carbon nanotubes using reversed phase, polar organic and normal phase chromatographic conditions using nano-liquid chromatography. Baseline separation was achieved for celiprolol, chlorpheniramine, etozoline, nomifensine and sulconazole under multimodal elution conditions. Satisfactory repeatability was achieved through run-to-run, column-to-column and batch-to-batch investigations. Our findings demonstrate that single-walled carbon nanotubes represent a promising stationary phase for the chiral separation and may open the field for a new class of chiral selectors.

  8. Review of old chemistry and new catalytic advances in the on-purpose synthesis of butadiene.

    Science.gov (United States)

    Makshina, Ekaterina V; Dusselier, Michiel; Janssens, Wout; Degrève, Jan; Jacobs, Pierre A; Sels, Bert F

    2014-11-21

    Increasing demand for renewable feedstock-based chemicals is driving the interest of both academic and industrial research to substitute petrochemicals with renewable chemicals from biomass-derived resources. The search towards novel platform chemicals is challenging and rewarding, but the main research activities are concentrated on finding efficient pathways to produce familiar drop-in chemicals and polymer building blocks. A diversity of industrially important monomers like alkenes, conjugated dienes, unsaturated carboxylic acids and aromatic compounds are thus targeted from renewable feedstock. In this context, on-purpose production of 1,3-butadiene from biomass-derived feedstock is an interesting example as its production is under pressure by uncertainty of the conventional fossil feedstock. Ethanol, obtained via fermentation or (biomass-generated) syngas, can be converted to butadiene, although there is no large commercial activity today. Though practised on a large scale in the beginning of the 20th century, there is a growing worldwide renewed interest in the butadiene-from-ethanol route. An alternative route to produce butadiene from biomass is through direct carbohydrate and gas fermentation or indirectly via the dehydration of butanediols. This review starts with a brief discussion on the different feedstock possibilities to produce butadiene, followed by a comprehensive summary of the current state of knowledge regarding advances and achievements in the field of the chemocatalytic conversion of ethanol and butanediols to butadiene, including thermodynamics and kinetic aspects of the reactions with discussions on the reaction pathways and the type of catalysts developed. PMID:24993100

  9. Ion permeable microcapsules for the release of biologically available ions for remineralization.

    Science.gov (United States)

    Davidson, Michael T; Greving, Theresa A; McHale, William A; Latta, Mark A; Gross, Stephen M

    2012-03-01

    The objective of this study was to investigate the effect of chemical structure, ion concentration, and ion type on the release rate of biologically available ions useful for remineralization from microcapsules with ion permeable membranes. A heterogeneous polymerization technique was utilized to prepare microcapsules containing either an aqueous solution of K₂HPO₄, Ca(NO₃)₂, or NaF. Six different polyurethane-based microcapsule shells were prepared and characterized based on ethylene glycol, butanediol, hexanediol, octanediol, triethylene glycol, and bisphenol A structural units. Ion release profiles were measured as a function of initial ion concentration within the microcapsule, ion type, and microcapsule chemical structure. The rate of ion release increased with initial concentration of ion stored in the microcapsule over a range of 0.5-3.0M. The monomer used in the synthesis of the membrane had a significant effect on ion release rates at 3.0 M salt concentration. At 1.0 M, the ethylene glycol released ions significantly faster than the hexanediol-, octanediol-, and butanediol-based microcapsules. Ion release was fastest for fluoride and slowest for phosphate for the salts used in this study. It was concluded that the microcapsules are capable of releasing calcium, phosphate, and fluoride ions in their biologically available form.

  10. Effects of Dental Methacrylates on Oxygen Consumption and Redox Status of Human Pulp Cells

    Directory of Open Access Journals (Sweden)

    Giuseppina Nocca

    2014-01-01

    Full Text Available Several studies have already demonstrated that the incomplete polymerization of resin-based dental materials causes the release of monomers which might affect cell metabolism. The aim of this study was to investigate the effects of triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, urethane dimethacrylate, and 2-hydroxyethyl methacrylate on (1 cellular energy metabolism, evaluating oxygen consumption rate, glucose consumption, glucose 6-phosphate dehydrogenase activity, and lactate production, and (2 cellular redox status, through the evaluation of glutathione concentration and of the activities of enzymes regulating glutathione metabolism. Methods. Human pulp cells were used and oxygen consumption was measured by means of a Clark electrode. Moreover, reactive oxygen species production was quantified. Enzymatic activity and glucose and lactate concentrations were determined through a specific kit. Results. Triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, and 2-hydroxyethyl methacrylate induced a decrease in oxygen consumption rate, an enhancement of glucose consumption, and lactate production, whilst glucose 6-phosphate dehydrogenase and glutathione reductase activity were not significantly modified. Moreover, the monomers induced an increase of reactive oxygen species production with a consequent increase of superoxide dismutase and catalase enzymatic activities. A depletion of both reduced and total glutathione was also observed. Conclusion. The obtained results indicate that dental monomers might alter energy metabolism and glutathione redox balance in human pulp cells.

  11. Effect of Additives on Liner Properties of Case-bonded Composite Propellants

    Directory of Open Access Journals (Sweden)

    S. B. Navale

    2004-07-01

    Full Text Available A thin layer of liner is applied to ensure a good bond between the insulator and the propellant in case-bonded rocket motors. It also acts as a protective shield for the insulatorby providing a limited fire protection effect. Liner compositions should preferably be based on the same binder system used in the propellant formulations. As the liner has to hold the propellant and the insulator without debond under all the environmental conditions, it plays a key role in predicted performance of a rocket motor. Hence, studies were carried out to improve the liner properties using various hydroxyl compounds, such as butanediol, cardanol, trimethylol propane, pyrogallol, etc as additives. Butanediol and phloroglucinol combination gave the best results in terms of mechanical properties and interface properties for the liner compositions. The effect of filler content on the liner properties was also studied. The results showed that higher filler content does not affect interface properties. Considering the fire retardancy effect and reinforcement of antimony trioxide (S£203, the formulation containing higher Sb2O3 was selected. The studies on pot life/castable life of liner showed that propellant could be cast up to 6 days after liner coating, without adversely affecting the bonding and the bond strength.

  12. The role of symmetry of chain extender in controlling the morphology of thermoplastic polyurethanes

    Science.gov (United States)

    Wamuo, Onyenkachi; Song, Cheng; Hsu, Shaw Ling

    Although polyurethane is a well-studied subject, the specific role of chain extender in the alteration of segmental dynamics and morphology formation has yet to be elucidated. Relatively low molecular weight thermoplastic polyurethanes synthesized from a two-step polymerization method were utilized in this study. The effect of the symmetry of chain extenders used in the polymerization on the morphological behavior has been studied. Comparison has been made for a number of chain extenders, including a symmetric 1,4 butanediol or 1,6 hexanediol and an asymmetric 1,2 propanediol or 1,3 butanediol. Using a combination of thermal analysis, spectroscopy and mechanical properties measurements, the development of morphological features were determined as a function of time and temperature. The symmetric chain-extended polyurethanes promotes the formation of hydrogen bonding, shows two glass transition temperatures consistent with a phase separation behavior and furthermore gives a more rigid, less extensible mechanical property when compared with the asymmetric chain-extended polyurethanes. In the latter case, the reacted polymer exhibits poor chain packing thus limiting the formation of robust hydrogen bonding behavior. It showed a singular glass transition representative of a more phase mixed system and shows more extensibility in terms of its mechanical behavior.

  13. A carbon sink pathway increases carbon productivity in cyanobacteria.

    Science.gov (United States)

    Oliver, John W K; Atsumi, Shota

    2015-05-01

    The burning of fossil reserves, and subsequent release of carbon into the atmosphere is depleting the supply of carbon-based molecules used for synthetic materials including plastics, oils, medicines, and glues. To provide for future society, innovations are needed for the conversion of waste carbon (CO2) into organic carbon useful for materials. Chemical production directly from photosynthesis is a nascent technology, with great promise for capture of CO2 using sunlight. To improve low yields, it has been proposed that photosynthetic capacity can be increased by a relaxation of bottlenecks inherent to growth. The limits of carbon partitioning away from growth within the cell and the effect of partitioning on carbon fixation are not well known. Here we show that expressing genes in a pathway between carbon fixation and pyruvate increases partitioning to 2,3-butanediol (23BD) and leads to a 1.8-fold increase in total carbon yield in the cyanobacterium Synechococcus elongatus PCC 7942. Specific 2,3-butanediol production increases 2.4-fold. As partitioning increases beyond 30%, it leads to a steep decline in total carbon yield. The data suggests a local maximum for carbon partitioning from the Calvin Benson cycle that is scalable with light intensity.

  14. Energy and chemicals from the selective electrooxidation of renewable diols by organometallic fuel cells.

    Science.gov (United States)

    Bellini, Marco; Bevilacqua, Manuela; Filippi, Jonathan; Lavacchi, Alessandro; Marchionni, Andrea; Miller, Hamish A; Oberhauser, Werner; Vizza, Francesco; Annen, Samuel P; Grützmacher, H

    2014-09-01

    Organometallic fuel cells catalyze the selective electrooxidation of renewable diols, simultaneously providing high power densities and chemicals of industrial importance. It is shown that the unique organometallic complex [Rh(OTf)(trop2NH)(PPh3)] employed as molecular active site in an anode of an OMFC selectively oxidizes a number of renewable diols, such as ethylene glycol , 1,2-propanediol (1,2-P), 1,3-propanediol (1,3-P), and 1,4-butanediol (1,4-B) to their corresponding mono-carboxylates. The electrochemical performance of this molecular catalyst is discussed, with the aim to achieve cogeneration of electricity and valuable chemicals in a highly selective electrooxidation from diol precursors.

  15. Classification of red wines using suitable markers coupled with multivariate statistic analysis.

    Science.gov (United States)

    Geana, Elisabeta Irina; Popescu, Raluca; Costinel, Diana; Dinca, Oana Romina; Ionete, Roxana Elena; Stefanescu, Ioan; Artem, Victoria; Bala, Camelia

    2016-02-01

    Methodologies for chemometric classification of five authentic red wine varieties from Murfatlar wine center, Romania, young and aged are reported. The discriminant analysis based on several anthocyanins, organic acids, (13)C/(12)C, (18)O/(16)O and D/H isotopic ratios, (1)H and (13)C NMR fingerprints revealed a very satisfactory categorization of the wines, both in terms of variety and vintage, thus illustrating the validity of selected variables for wine authentication purposes. LDA applied to the combined data shows 85.7% classification of wines according to grape variety and 71.1% classification of wines according to vintage year, including a control wine set for each categorization, thus allowing an accurate interpretation of the data. Thereby, anthocyanins, certain anthocyanin ratios, oxalic, shikimic, lactic, citric and succinic acids, sugars like glucose, amino acids like histidine, leucine, isoleucine and alanine, and also 2,3-butanediol, methanol, glycerol and isotopic variables were significant for classification of wines.

  16. Process development of short-chain polyols synthesis from corn stover by combination of enzymatic hydrolysis and catalytic hydrogenolysis

    Directory of Open Access Journals (Sweden)

    Zhen-Hong Fang

    2014-09-01

    Full Text Available Currently short-chain polyols such as ethanediol, propanediol, and butanediol are produced either from the petroleum feedstock or from the starch-based food crop feedstock. In this study, a combinational process of enzymatic hydrolysis with catalytic hydrogenolysis for short-chain polyols production using corn stover as feedstock was developed. The enzymatic hydrolysis of the pretreated corn stover was optimized to produce stover sugars at the minimum cost. Then the stover sugars were purified and hydrogenolyzed into polyols products catalyzed by Raney nickel catalyst. The results show that the yield of short-chain polyols from the stover sugars was comparable to that of the corn-based glucose. The present study provided an important prototype for polyols production from lignocellulose to replace the petroleum- or corn-based polyols for future industrial applications.

  17. Development of a hydrophobic polymer composition with improved biocompatibility for making foldable intraocular lenses

    Science.gov (United States)

    Haldar, R. S.; Chauhan, R.; Kapoor, K.; Niyogi, U. K.

    2014-05-01

    A hydrophobic composition for foldable intraocular lenses was developed by copolymerizing phenyl ethyl acrylate, phenyl ethyl methacrylate and butanediol diacrylate by gamma irradiation. Aqueous solution of heparin, a biocompatibilizer absorbed in hydroxyethyl methacrylate was added to the monomer mixture before irradiation to impart desired level of hydrophilicity and improved biocompatibility to the hydrophobic composition. Ketorolac tromethamine, an anti-inflammatory agent and L-glutathione, an antioxidant were added to the composition as functional additive for exhibiting improved performance while in use. Concentrations of monomers, biocompatibilizer and functional additives were optimized to develop an advanced material for foldable intraocular lenses. Transmittance, refractive index, Abbe number, hardness, tensile strength, flexibility and foldability were studied on the final composition. Scanning electron microscopic study, differential scanning calorimetric analysis, leachability and viscometry confirmed the permanent incorporation of additives into the polymer. Results of haemocompatibility, tissue implantation and cytotoxicity confirm that the biocompatibility of the base polymer was improved by incorporation of heparin.

  18. Metal organic framework MIL-101(Cr) for dehydration reactions

    Indian Academy of Sciences (India)

    M Suresh; B David Raju; K S Rama Rao; K Raveendranath Reddy; M Lakshmi Kantam; Pavuluri Srinivasu

    2014-03-01

    Porous chromium terephthalate MIL-101 (Cr-MIL-101) has been prepared by direct method under hydrothermal conditions and characterized using X-ray diffraction, N2 sorption, TGA and FT-IR. The nitrogen adsorption-desorption isotherm shows that the Cr-MIL-101 possesses BET specific surface area of 2563 m2/g. Catalytic performance of Cr-MIL-101 in the dehydration of 1,4-butanediol and 1-phenylethanol is assessed under vapour phase conditions in the temperature range of 513-533 K and time on stream (TOS) at 513 K. Cr-MIL-101 demonstrates superior catalytic activity with conversion of 95% of 1-phenylethanol. Moreover, high surface area and nanocages with coordinated unsaturated sites of Cr-MIL-101 have allowed us to attain higher dehydrated products selectivity than Cr-supported activated carbon (Cr/AC), amberlyst-15 and HZSM-5 catalysts.

  19. Simultaneous Determination of Five Alcohols in E-cigarette Emissions by Gas Chromatography-Mass Spectrometry%GC/MS法同时测定电子烟烟气释放物中的5种醇类化合物

    Institute of Scientific and Technical Information of China (English)

    段沅杏; 吴亿勤; 杨威; 杨继; 韩敬美; 田永峰; 赵伟; 杨柳; 陈永宽

    2015-01-01

    In order to accurately determine the contents of alcohols in e-cigarette emissions, a gas chromatography-mass spectrometry (GC/MS) method was developed for simultaneously determining 1, 2-propylene glycol, 1,3-butanediol, glycerol, diethylene glycol and triethylene glycol, wherein 1, 4-butanediol was used as an internal standard. Sixteen samples of e-cigarette were tested by the developed method. The results showed that: 1) The limit of detection and limit of quantitation were 0.08-0.32 and 0.27-1.07 μg/puff, respectively; the recoveries were 90.0%-99.5% with the relative standard deviations (RSD) ranged from 1.20% to 4.93%. 2) 1,2-Propylene glycol and glycerin were detectable, while diethylene glycol and triethylene glycol were undetectable in all samples; and 1,3-butanediol was detectable in four samples. 3) This method was suitable for the qualitative and quantitative determination of 1,2-propylene glycol, 1,3-butanediol, glycerol, diethylene glycol, triethylene glycol in e-cigarette emissions.%为了准确测定电子烟烟气释放物中醇类化合物的量,以1,4-丁二醇为内标建立了同时检测电子烟烟气释放物中1,2-丙二醇、1,3-丁二醇、丙三醇、二甘醇和三甘醇的气相色谱/质谱(GC/MS)方法,采用该法测定了16种电子烟样品.结果表明:①该法的检出限和定量限范围在0.08~0.32 μg/口和0.27~1.07 μg/口之间;回收率在90.0%~99.5%之间,相对标准偏差(RSD)为1.20%~4.93%.②所测样品中均检出1,2-丙二醇、丙三醇,均未检出二甘醇和三甘醇;4个样品中检测出1,3-丁二醇.该法灵敏度高、定性准确,适合电子烟样品烟气释放物中1,2-丙二醇、1,3-丁二醇、丙三醇、二甘醇和三甘醇的定性定量分析.

  20. Chemical structures and thermal properties of polyesters obtained from different samples of bio diesel epoxidized; Estruturas quimicas e propriedades termicas de poliesteres obtidos a partir de diferentes tipos de biodiesel epoxidado

    Energy Technology Data Exchange (ETDEWEB)

    Samios, Dimitrios; Reiznautt, Quelen B.; Nicolau, Aline; Martini, Denise D.; Chagas, Arthur L. das, E-mail: dsamios@iq.ufrgs.b [Universidade Federal do Rio Grande do Sul (IQ/UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica. Lab. de Instrumentacao e Dinamica Molecular

    2009-07-01

    In this work new structures from oligo esters and polyesters from different oils (olive oil, sunflower oil and linseed oil) were synthesized and characterized. Oligo esters and polyesters were synthesized from the reaction of fatty acid methyl epoxy-esters, obtained from different oils, with cis-1,2-cyclohexanedicarboxylic anhydride in the presence of triethylamine (TEA). Different amounts of the resin 1,4-butanediol diglycidyl ether (BDGE) were added in order to increase the capacity of crosslinking. The molar ratio of BDGE used in system was between 0 and 0.066. The intermediate structures, as well as the oligo esters and polyesters produced, were analyzed by using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance ({sup 1}H - NMR). The thermal behavior of the products was realized through differential scanning calorimetry and Thermogravimetric analyses. The presence of BDGE in the materials chains increases the bonding capacity resulting in a higher molecular weight material which presents good thermal stability. (author)

  1. The Antitumor Components from Marine-derived Bacterium Streptoverticillium luteoverticillatum 11014 Ⅱ

    Institute of Scientific and Technical Information of China (English)

    LI Dehai; ZHU Tianjiao; FANG Yuchun; LIU Hongbing; GU Qianqun; ZHU Weiming

    2007-01-01

    Eight known compounds were isolated from a marine-derived bacterium Streptoverticillium luteoverticillatum 11014 using bioassay-guided fractionations. Their structures were identified by spectral analysis as bis (4-hydroxybenzyl) ether (1), p-hydroxyphenylethyl alcohol (2), N-(4-hydroxyphenethyl) acetamide (3), indole-3 carboxylic acid methyl ester (4), dibenzo[b,e] [1,4]dioxine (5), thymine (6), cytosine deoxyribonucleoside (7) and 2, 3-butanediol (8). These compounds were evaluated for their cytotoxic activities against K562 cell line with the SRB method for the first time. Compounds 2 and 4 showed cytotoxcities with IC50 values of 101.1 and 165.3 μmolL-1, respectively. All compounds were isolated from S. luteoverticillatum 11014 for the first time.

  2. Hyperproduction of poly(4-hydroxybutyrate) from glucose by recombinant Escherichia coli

    DEFF Research Database (Denmark)

    Zhou, Xiao-Yun; Yuan, Xiao-Xi; Shi, Zhen-Yu;

    2012-01-01

    -hydroxybutyrate or 1,4-butanediol (1,4-BD) are provided as precursor which are much more expensive than glucose. At present, high production cost is a big obstacle for large scale production of poly(4HB). RESULTS: Recombinant Escherichia coli strain was constructed to achieve hyperproduction of poly(4......-hydroxybutyrate) [poly(4HB)] using glucose as a sole carbon source. An engineering pathway was established in E. coli containing genes encoding succinate degradation of Clostridium kluyveri and PHB synthase of Ralstonia eutropha. Native succinate semialdehyde dehydrogenase genes sad and gabD in E. coli were both...... inactivated to enhance the carbon flux to poly(4HB) biosynthesis. Four PHA binding proteins (PhaP or phasins) including PhaP1, PhaP2, PhaP3 and PhaP4 from R. eutropha were heterologously expressed in the recombinant E. coli, respectively, leading to different levels of improvement in poly(4HB) production...

  3. Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

    Directory of Open Access Journals (Sweden)

    Elena Vlad

    2012-01-01

    Full Text Available Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics.

  4. Mechanical Properties and Morphology of the Clay/Waterborne Polyurethane Nanocomposite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongcheng; WANG Junwei; ZHAO Yuhua; KANG maoqing; WANG Xinkui

    2006-01-01

    Stable clay/waterborne polyurethane nanocompostie dispersions were synthesized by sulfonated poly ( butylene adipate ) diol , 4,4-diphenylmethane diisocyanate , dimethyl propionic acid, 1,4-butanediol, triethyl anine and clay-water dispersion through a route named prepolymer acetone mixing progress. The reinforced mechanical properties and thermal resistance of films casting from it were examined by dynamic mechanical analyses (DMA), thermogravimetric analyses (TGA) and tensile tests. Furthermore, the morphology of these nanocompostie films and dispersions were observed by transmission electron microscopy (TEM), scanning electron microscopy( SEM), wide-angle X-ray diffraction analyses( WXRD ). The experimental results reveal that the clay could be predominantly dispersed in the pristine polymer forming nanocomposties, and evidendy enhanced the tensile properties and modulus of it. Additionally, the best-reinforced effect could occur when the clay content was near 1 wt% .

  5. Curing mechanism of TDE-85/MeTHPA epoxy resin modified by polyurethane

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; ZHENG Zi-qiao; REN Dong-yan; HUANG Yao-peng

    2007-01-01

    Diglycidyl 4,5-epoxy tetrahydro phthalate/methyl tetrahydrophthalic anhydride (TDE-85/MeTHPA) epoxy resin modified by polyurethane (PU) was prepared with 1,4-butanediol (1,4-BDO), trimethylol propane (TMP) and polyurethane prepolymer synthesized by polypropylene glycol and toluene diisocynate. Chemical reaction and curing mechanism of this system were discussed by incorporating the results of infra spectrum analysis. The results indicate that the epoxy polymeric network Ⅰ is obtained by the curing reaction between TDE-85 and MeTHPA, while the PU polymeric network Ⅱ is obtained by the chain-extended and crosslinking reaction between 1,4-BDO, TMP and polyurethane prepolymer(PUP). The graft chemical bonds are formed between polymer networks Ⅰ and Ⅱ that therefore increase the degree of blend and compatibility between epoxy polymer and PU.

  6. Bio-based production of monomers and polymers by metabolically engineered microorganisms.

    Science.gov (United States)

    Chung, Hannah; Yang, Jung Eun; Ha, Ji Yeon; Chae, Tong Un; Shin, Jae Ho; Gustavsson, Martin; Lee, Sang Yup

    2015-12-01

    Recent metabolic engineering strategies for bio-based production of monomers and polymers are reviewed. In the case of monomers, we describe strategies for producing polyamide precursors, namely diamines (putrescine, cadaverine, 1,6-diaminohexane), dicarboxylic acids (succinic, glutaric, adipic, and sebacic acids), and ω-amino acids (γ-aminobutyric, 5-aminovaleric, and 6-aminocaproic acids). Also, strategies for producing diols (monoethylene glycol, 1,3-propanediol, and 1,4-butanediol) and hydroxy acids (3-hydroxypropionic and 4-hydroxybutyric acids) used for polyesters are reviewed. Furthermore, we review strategies for producing aromatic monomers, including styrene, p-hydroxystyrene, p-hydroxybenzoic acid, and phenol, and propose pathways to aromatic polyurethane precursors. Finally, in vivo production of polyhydroxyalkanoates and recombinant structural proteins having interesting applications are showcased. PMID:26318077

  7. Effects of Polybenzoxazine on Shape Memory Properties of Polyurethanes with Amorphous and Crystalline Soft Segments

    Directory of Open Access Journals (Sweden)

    Senlong Gu

    2014-04-01

    Full Text Available This paper evaluates the role of minor component polybenzoxazine (PB on shape-memory properties of polyurethanes (PU with glassy and crystalline soft segments. The polymer compounds were prepared in two steps. In the first step, benzoxazine, polyurethane pre-polymer, and chain extender butanediol (BD were mixed into a solution followed by chain-extension of the pre-polymer with BD. In the second step, benzoxazine was polymerized at 180 °C for 3 h to obtain shape memory polymer compounds. The atomic force microscopy images revealed that the PB-phase formed uniform dispersions in PU. The presence of PB-phase induced shape-memory behavior in non-shape memory PU with amorphous soft segment and significantly improved the values of shape fixity, recovery ratio, and recovery stress in shape memory polyurethane with crystalline soft segment.

  8. Phytoremediation of heavy and transition metals aided by legume-rhizobia symbiosis

    DEFF Research Database (Denmark)

    Hao, X.; Taghavi, S.; Xie, P.;

    2014-01-01

    Legumes are important for nitrogen cycling in the environment and agriculture due to the ability of nitrogen fixation by rhizobia. In this review, we introduce an important and potential role of legume-rhizobia symbiosis in aiding phytoremediation of some metal contaminated soils as various legumes...... have been found to be the dominant plant species in metal contaminated areas. Resistant rhizobia used for phytoremediation could act on metals directly by chelation, precipitation, transformation, biosorption and accumulation. Moreover, the plant growth promoting (PGP) traits of rhizobia including...... nitrogen fixation, phosphorus solubilization, phytohormone synthesis, siderophore release, and production of ACC deaminase and the volatile compounds of acetoin and 2, 3-butanediol may facilitate legume growth while lessening metal toxicity. The benefits of using legumes inoculated with naturally resistant...

  9. Synthesis and characterization of bio-based polyurethane from benzoylated cashewnut husk tannins

    Indian Academy of Sciences (India)

    A J Sunija; S Siva Ilango; K P Vinod Kumar

    2014-05-01

    Benzoylated tannin prepared by benzoylation of cashewnut husk tannin, was treated with hexame-thylenediisocyanate in the presence of 1,4-butanediol as an extender to prepare thermosetting polyurethane. The sample was characterized using FT–IR and 13C NMR spectra. Thermal, morphological, physico-chemical and electrical properties were also investigated. Polyurethane obtained was sensitive to moisture but had very good solvent resistance. Results show that g of the sample is 260 °C and thermal decomposition begins at 280 °C. The dielectric constant varies randomly with temperature. The conductivity of the sample was found to increase with increase in temperature but shows random variation at 90 and 150 °C

  10. Thermal stability of segmented polyurethane elastomers reinforced by clay particles

    Directory of Open Access Journals (Sweden)

    Pavličević Jelena

    2009-01-01

    Full Text Available The aim of this work was to determine the influence of clay nanoparticles on thermal properties of segmented polyurethanes based on hexamethylene- diisocyanate, aliphatic polycarbonate diol and 1,4-butanediol as chain extender. The organically modified particles of montmorillonite and bentonite were used as reinforcing fillers. The structure of elastomeric materials was varied either by diol type or chain extender content. The ratio of OH groups from diol and chain extender (R was either 1 or 10. Thermal properties of prepared materials were determined using modulated differential scanning calorimetry (MDSC. Thermal stability of obtained elastomers has been studied by simultaneously thermogravimetry coupled with DSC. The glass transition temperature, Tg, of soft segments for all investigated samples was about -33°C. On the basis of DTG results, it was concluded that obtained materials were very stable up to 300°C.

  11. Rapid preparation and characterization of methacrylate-based monoliths for chromatographic and electrophoretic separation.

    Science.gov (United States)

    Fan, Li-Qun; Zhang, Yu-Ping; Gong, Wen-Jun; Qu, Ling-Bo; Lee, Kwang-Pill

    2010-01-01

    Butyl-methacrylate-based porous monoliths were rapidly prepared in the fused-silica capillary with a 10-cm stripe of polyimide removed from its exterior. The photopolymerization could be carried out in 150 s using ethylene glycol dimethacrylate as a cross-linking agent; 1-propanol, 1,4-butanediol, and water as tri-porogenic solvents; and Irgacure 1800 as a photo-initiator. The effect of different morphologies on the efficiency and retention properties was investigated using pressure-assisted CEC (p-CEC), CEC, and low pressure-assisted liquid chromatography modes (LPLC). Baseline separation of the model analytes was respectively achieved including thiourea, toluene, naphthalene, and biphenyl with the lowest theoretical height up to 8.0 microm for thiourea in the mode of p-CEC. Furthermore, the influence of the tri-porogenic solvents on the morphology of methacrylate-based monoliths was systematically studied with mercury intrusion porosimetry and scanning electron microscopy. PMID:20515536

  12. Carbon recovery by fermentation of CO-rich off gases - Turning steel mills into biorefineries.

    Science.gov (United States)

    Molitor, Bastian; Richter, Hanno; Martin, Michael E; Jensen, Rasmus O; Juminaga, Alex; Mihalcea, Christophe; Angenent, Largus T

    2016-09-01

    Technological solutions to reduce greenhouse gas (GHG) emissions from anthropogenic sources are required. Heavy industrial processes, such as steel making, contribute considerably to GHG emissions. Fermentation of carbon monoxide (CO)-rich off gases with wild-type acetogenic bacteria can be used to produce ethanol, acetate, and 2,3-butanediol, thereby, reducing the carbon footprint of heavy industries. Here, the processes for the production of ethanol from CO-rich off gases are discussed and a perspective on further routes towards an integrated biorefinery at a steel mill is given. Recent achievements in genetic engineering as well as integration of other biotechnology platforms to increase the product portfolio are summarized. Already, yields have been increased and the portfolio of products broadened. To develop a commercially viable process, however, the extraction from dilute product streams is a critical step and alternatives to distillation are discussed. Finally, another critical step is waste(water) treatment with the possibility to recover resources. PMID:27095410

  13. Microstructural organization of polydimethylsiloxane based polyurethane block copolymers

    Science.gov (United States)

    Hernandez, Rebeca; Weksler, Jadwiga; Padsalgikar, Ajay; Runt, James

    2007-03-01

    Microphase separation was investigated for polyurethane block copolymers synthesized from MDI and 1,4 butanediol as the hard segments, and poly(hexamethyleneoxide) (MW ˜ 700) and bis(6-hydroxyethoxypropyl) poly(dimethylsiloxane) as soft segments (MW ˜ 1000). The neat PDMS-based diol presents two segmental relaxations corresponding to the principle siloxane repeat unit and to the hydroxyethoxypropyl end group segments, respectively. When incorporated in the polyurethane, the siloxane units form a phase without intermixing with hard segments and the polyether end group segments are mixed with the second macrodiol and some short hard segment sequences. The microdomain morphology was characterized by atomic force microscopy and small-angle X-ray scattering, and the scattering data were analyzed using an approach based on a modified core-shell model. The model includes core hard segment particles (MDI-BDO), surrounded by a mixed polyether shell (PHMO and hydroxyethoxypropyl end group segments), and a matrix composed of the siloxane units.

  14. Surface Characteristics of Cotton/ Polyester Fabric Coated with Poly-urethane Elastomers Cured Thermally or by Using Gamma Irradiation

    International Nuclear Information System (INIS)

    Different Polyurethane (PU) elastomerics formulations were prepared by using 4, 4'-diphenyl methane diisocyanate, polyol (castor oil; CO), chain extender (1,4-butanediol); CE and catalyst. The prepared PU formulations were applied as coating films up on the cotton/ polyester blend fabric surface. The specimens were cured to complete the reaction of the PU spell, either thermally (140°C) or by using γ-rays at different doses (30-150 kGy). The PU layer formed up on the fabric surface was characterized by using Fourier-transform infrared (FTIR). The effects of CE percent and the used curing system on the coated fabrics properties, such as mechanical properties, thermal stability, water absorbance, crease recovery and surface morphology were investigated. The results showed that the increasing of CE percent and the irradiation dose lead to improving the tensile strength; MPa and the thermal stability, while, the elongation at break (%), crease recovery and water absorbance were decreased.

  15. Chemical Constituents of Phacellaria compressa Benth.

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two new compounds, 1-(3-methoxy-4-hydroxyphenyl)-3-(3, 5-dimethoxy-4-hydroxyphenyl)-propane (1) and 5, 7,3'-trimethyoxyflavan-4'-O-β-D-glucopyranoside (2) were isolated from the ethanol extract of the dried aerial parts of Phacellaria compressa Benth., together with 2,3-bis[(4-hydroxy-3,5-dimethoxyphenyl)-methyl]-1,4-butanediol (3), ethyl 3,4,5-trihydroxybenzoate (4), methyl 3, 4, 5-trihydroxybenzoate (5), β-sitosterol (6), 5, 7, 3', 4'-tetrahydroxyflavan (7), lupeol (8), zhebeiresinol (9), quercetin-3-O-α-L-rhamnopyranoside (10), (+)-catechin (11),betulin (12), β-daucosterol (13), (+)-syringaresinol (14), scopoletin (15), and proximadiol (16). The structures of these compounds were determined by spectral evidence or by comparing them with authentic samples.Compound 9 showed α-amylase inhibitory activity of 57.55% at a concentration of 50 μg/mL.

  16. Nucleic acid compositions and the encoding proteins

    Science.gov (United States)

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  17. The small angle neutron scattering study on the segmented polyurethane

    Energy Technology Data Exchange (ETDEWEB)

    Sudirman; Gunawan; Prasetyo, S.M.; Karo Karo, A.; Lahagu, I.M.; Darwinto, Tri [Materials Science Research Center, National Nuclear Energy Agency, Serpong, Tangerang (Indonesia)

    1999-10-01

    The distance between hard segment (HS) and soft segment (SS) of segmented polyurethane have been determined using the Small Angle Neutron Scattering (SANS) technique. The segmented Polyurethanes (SPU) are linear multiblock copolymers, which include elastomer thermoplastic. SPU consist of hard segment and soft segment, each has tendency to make a group with similar type to form a domain. The soft segments used were polypropylene glycol (PPG) and 4,4 diphenylmethane diisocyanate (MDI), while l,4 butanediol (BD) was used as hard segment. The characteristic of SPU depends on its phase structure which is affected by several factors, such as type of chemical formula and the composition of the HS and SS, solvent as well as the synthesizing process. The samples used in this study were SPU56 and SPU68. Based on the appearance of SANS profile, it was obtained that domain distances are 12.32 nm for the SPU56 and 19 nm for the SPU68. (author)

  18. Effect of different polyol-based plasticizers on thermal properties of polyvinyl alcohol:starch blends.

    Science.gov (United States)

    Aydın, Ahmet Alper; Ilberg, Vladimir

    2016-01-20

    A series of gelatinized polyvinyl alcohol (PVA):starch blends were prepared with various polyol-based plasticizers in 5 wt%, 15 wt% and 25 wt% ratios via solution casting method. The obtained films were analyzed by Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Remarkable changes have been observed in glass-transition temperature (Tg) and thermal stability of the samples containing varying concentrations of different plasticizers and they have been discussed in detail with respect to the conducted thermal and chemical analyses. The observed order of Tg point depression of the samples containing 15 wt% plasticizer is 1,4-butanediol - 1,2,6-hexanetriol--pentaerythriyol--xylitol--mannitol, which is similar to the sequence of the thermal stability changes of the samples. PMID:26572374

  19. Preparation and Properties of Tung Oil-Based Polyurethane

    Institute of Scientific and Technical Information of China (English)

    袁才登; 赵晓明; 邵丽英; 唐克华

    2014-01-01

    Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oil-based anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the proper-ties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The re-sults show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.

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

    Directory of Open Access Journals (Sweden)

    Angélica Díaz

    2014-04-01

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

  1. Synthesis and surface properties of polyurethane modified by polysiloxane

    Institute of Scientific and Technical Information of China (English)

    Linlin FENG; Xingyuan ZHANG; Jiabing DAI; Zhen GE; Jing CHAO; Chenyan BAI

    2008-01-01

    A series of polyurethanes modified by polysiloxane (Si-PU) were synthesized based on 2,4-toluene diisocyanate (TDI), dihydroxybutyl-terminated polydimethylsiloxane (DHPDMS), polytetramethylene glycol (PTMG) and 1,4-butanediol (BDO). Fourier transform infrared spectroscopy analysis showed that DHPDMS had been incorporated into the polyurethane chains. With the increase of DHPDMS content, the water contact angle increased while the surface tension decreased. As the DHPDMS content increases above 5%, both the contact angle and the surface tension tend to approach a constant. The contact angle increases with increasing temperature, and it tends to approach a constant when the temperature is higher than 50℃. The result indicates that Si-PU exhibits good surface and mechanical properties when the DHPDMS content is 5%.

  2. SYNTHETIC STUDIES ON BLOOD COMPATIBLEBIOMATERIALS 13: A NOVEL SEGMENTED POLYURETHANE CONTAINING PHOSPHORYLCHOLINE STRUCTURE: SYNTHESIS, CHARACTERIZATION AND BLOOD COMPATIBILITY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    P. Najafi Mogaddam; A. Entezami

    2003-01-01

    A new phosphorylcholine, (6-hydroxy)hexyl-2-(trimethylammonio)ethyl phosphate (HTEP), was synthesized and characterized. Segmented polyurethane (SPU) containing phosphorylcholine structure was synthesized based on diphenylmethane diisocyanate (MDI), soft segment polytetramethylene glycol (PTMG) and HTEP, with 1,4-butanediol (BD)as a chain extender. The existence of phosphorylcholine structure on the surface of SPU was revealed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. The blood compatibilities of the polymers were evaluated by hemolytic testing and a platelet-rich plasma (PRP) adhesion experiment, which was viewed by scanning electron microscopy (SEM) with polyurethane as a reference. The novel segmented polyurethane containing phosphorylcholine structure showed improved blood compatibility.

  3. Preparation of films of a highly aligned lipid cubic phase.

    Science.gov (United States)

    Squires, Adam M; Hallett, James E; Beddoes, Charlotte M; Plivelic, Tomás S; Seddon, Annela M

    2013-02-12

    We demonstrate a method by which we can produce an oriented film of an inverse bicontinuous cubic phase (Q(II)(D)) formed by the lipid monoolein (MO). By starting with the lipid as a disordered precursor (the L(3) phase) in the presence of butanediol, we can obtain a film of the Q(II)(D) phase showing a high degree of in-plane orientation by controlled dilution of the sample under shear within a linear flow cell. We demonstrate that the direction of orientation of the film is different from that found in the oriented bulk material that we have reported previously; therefore, we can now reproducibly form Q(II)(D) samples oriented with either the [110] or the [100] axis aligned in the flow direction depending on the method of preparation. The deposition of MO as a film, via a moving fluid-air interface that leaves a coating of MO in the L(3) phase on the capillary wall, leads to a sample in the [110] orientation. This contrasts with the bulk material that we have previously demonstrated to be oriented in the [100] direction, arising from flow producing an oriented bulk slug of material within the capillary tube. The bulk sample contains significant amounts of residual butanediol, which can be estimated from the lattice parameter of the Q(II)(D) phase obtained. The sample orientation and lattice parameters are determined from synchrotron small-angle X-ray scattering patterns and confirmed by simulations. This has potential applications in the production of template materials and the growth of protein crystals for crystallography as well as deepening our understanding of the mechanisms underlying the behavior of lyotropic liquid-crystal phases. PMID:23347289

  4. Role of a Highly Conserved and Catalytically Important Glutamate-49 in the Enterococcus faecalis Acetolactate Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Miyoung; Lee, Sangchoon; Cho, Junehaeng; Ryu, Seong Eon; Yoon, Moonyoung [Hanyang Univ., Seoul (Korea, Republic of); Koo, Bonsung [Rural Development Administration, Suwon (Korea, Republic of)

    2013-02-15

    Acetolactate synthase (ALS) is a thiamine diphosphate (ThDP)-dependent enzyme that catalyzes the decarboxylation of pyruvate and then condenses the hydroxyethyl moiety with another molecule of pyruvate to give 2-acetolactate (AL). AL is a key metabolic intermediate in various metabolic pathways of microorganisms. In addition, AL can be converted to acetoin, an important physiological metabolite that is excreted by many microorganisms. There are two types of ALSs reported in the literature, anabolic aceto-hydroxyacid synthase (AHAS) and catabolic ALSs (cALS). The anabolic AHAS is primarily found in plants, fungi, and bacteria, is involved in the biosynthesis of branched-chain amino acids (BCAAs), and contains flavin adenine dinucleotide (FAD), whereas the cALS is found only in some bacteria and is involved in the butanediol fermentation pathway. Both of the enzymes are ThDP-dependent and require a divalent metal ion for catalytic activity. Despite the similarities of the reactions catalyzed, the cALS can be distinguished from anabolic AHAS by a low optimal pH of about 6.0, FAD-independent functionality, a genetic location within the butanediol operon, and lack of a regulatory subunit. It is noteworthy that the structural and functional features of AHAS have been extensively studied, in contrast to those of cALS, for which only limited information is available. To date, the only crystal structure of cALS reported is from Klebsiella pneumonia, which revealed that the overall structure of K. pneumonia ALS is similar to that of AHAS except for the FAD binding region found in AHAS.

  5. Microwave-assisted on-spot derivatization for gas chromatography-mass spectrometry based determination of polar low molecular weight compounds in dried blood spots.

    Science.gov (United States)

    Sadones, Nele; Van Bever, Elien; Archer, John R H; Wood, David M; Dargan, Paul I; Van Bortel, Luc; Lambert, Willy E; Stove, Christophe P

    2016-09-23

    Dried blood spot (DBS) sampling and analysis is increasingly being applied in bioanalysis. Although the use of DBS has many advantages, it is also associated with some challenges. E.g. given the limited amount of available material, highly sensitive detection techniques are often required to attain sufficient sensitivity. In gas chromatography coupled to mass spectrometry (GC-MS), derivatization can be helpful to achieve adequate sensitivity. Because this additional sample preparation step is considered as time-consuming, we introduce a new derivatization procedure, i.e. "microwave-assisted on-spot derivatization", to minimize sample preparation of DBS. In this approach the derivatization reagents are directly applied onto the DBS and derivatization takes place in a microwave instead of via conventional heating. In this manuscript we evaluated the applicability of this new concept of derivatization for the determination of two polar low molecular weight molecules, gamma-hydroxybutyric acid (GHB) and gabapentin, in DBS using a standard GC-MS configuration. The method was successfully validated for both compounds, with imprecision and bias values within acceptance criteria (<20% at LLOQ, <15% at 3 other QC levels). Calibration lines were linear over the 10-100μg/mL and 1-30μg/mL range for GHB and gabapentin, respectively. Stability studies revealed no significant decrease of gabapentin and GHB in DBS upon storage at room temperature for at least 84 days. Furthermore, DBS-specific parameters, including hematocrit and volume spotted, were evaluated. As demonstrated by the analysis of GHB and gabapentin positive samples, "microwave-assisted on-spot derivatization" proved to be reliable, fast and applicable in routine toxicology. Moreover, other polar low molecular weight compounds of interest in clinical and/or forensic toxicology, including vigabatrin, beta-hydroxybutyric acid, propylene glycol, diethylene glycol, 1,4-butanediol and 1,2-butanediol, can also be

  6. Conservation and diversity of seed associated endophytes in Zea across boundaries of evolution, ethnography and ecology.

    Directory of Open Access Journals (Sweden)

    David Johnston-Monje

    Full Text Available Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte to modern maize (corn and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed

  7. Reduction of ethanol yield and improvement of glycerol formation by adaptive evolution of the wine yeast Saccharomyces cerevisiae under hyperosmotic conditions.

    Science.gov (United States)

    Tilloy, Valentin; Ortiz-Julien, Anne; Dequin, Sylvie

    2014-04-01

    There is a strong demand from the wine industry for methodologies to reduce the alcohol content of wine without compromising wine's sensory characteristics. We assessed the potential of adaptive laboratory evolution strategies under hyperosmotic stress for generation of Saccharomyces cerevisiae wine yeast strains with enhanced glycerol and reduced ethanol yields. Experimental evolution on KCl resulted, after 200 generations, in strains that had higher glycerol and lower ethanol production than the ancestral strain. This major metabolic shift was accompanied by reduced fermentative capacities, suggesting a trade-off between high glycerol production and fermentation rate. Several evolved strains retaining good fermentation performance were selected. These strains produced more succinate and 2,3-butanediol than the ancestral strain and did not accumulate undesirable organoleptic compounds, such as acetate, acetaldehyde, or acetoin. They survived better under osmotic stress and glucose starvation conditions than the ancestral strain, suggesting that the forces that drove the redirection of carbon fluxes involved a combination of osmotic and salt stresses and carbon limitation. To further decrease the ethanol yield, a breeding strategy was used, generating intrastrain hybrids that produced more glycerol than the evolved strain. Pilot-scale fermentation on Syrah using evolved and hybrid strains produced wine with 0.6% (vol/vol) and 1.3% (vol/vol) less ethanol, more glycerol and 2,3-butanediol, and less acetate than the ancestral strain. This work demonstrates that the combination of adaptive evolution and breeding is a valuable alternative to rational design for remodeling the yeast metabolic network. PMID:24532067

  8. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    Science.gov (United States)

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g.

  9. Liquid fuel production from hemicellulose. 2 Volumes

    Energy Technology Data Exchange (ETDEWEB)

    1983-03-01

    Hemicellulose was derived from a variety of pretreated wood substrates. A variety of different fungi was screened for the ability of their culture filtrates to hydrolyse hemicellulose to its composite sugars. Three strains of Clostridia were screened to see which could produce higher amounts of solvents from those sugars. C. acetobutylicum proved to produce highest amounts of butanol and conditions for maximum solvent production by this anaerobe were defined. Six strains of facultative anaerobes were screened for their ability to produce power solvents from hemicellulose derived sugars. Klebsiella pneumoniae could efficiently utilize all the major sugars present in wood hemicellulose with 2,3-butanediol being the major end product. The conditions for maximum diol production by K. pneumoniae grown on sugars normally found in hemicellulose hydrolysates were defined. The utilization of wood hemicellulose hydrolyzates by microorganisms for the production of liquid fuels was investigated. Pretreatment of aspen wood by steam-explosion was optimized with respect to maximizing the pentosan yields in the water-soluble fractions of steam-treated substrates. These fractions were then hydrolyzed by dilute sulphuric acid or by the xylanase enzyme(s) present in the culture filtrates of Trichoderma harzianum. The relative efficiencies of hydrolysis were compared with respect to the release of reducing sugars and monosaccharides. The hemicellulose hydrolyzates were then used as substrates for fermentation. Butanediol yields of 0.4-0.5 g per g of sugar consumed were achieved using K. pneumoniae up to 0.16 g butanol could be attained per g of hemicellulose sugar utilized. 102 refs., 50 figs., 169 tabs.

  10. Carbonate phosphonium salts as catalysts for the transesterification of dialkyl carbonates with diols. The competition between cyclic carbonates and linear dicarbonate products.

    Science.gov (United States)

    Selva, Maurizio; Caretto, Alessio; Noè, Marco; Perosa, Alvise

    2014-06-28

    At 90-120 °C, in the presence of methylcarbonate and bicarbonate methyltrioctylphosphonium salts as catalysts ([P8881][A]; [A] = MeOCO2 and HOCO2), the transesterification of non-toxic dimethyl- and diethyl-carbonate (DMC and DEC, respectively) with 1,X-diols (2 ≤ X ≤ 6) proceeds towards the formation of cyclic and linear products. In particular, 1,2-propanediol and ethylene glycol afford propylene- and ethylene-carbonate with selectivity and yields up to 95 and 90%, respectively; while, the reaction of DMC with higher diols such 1,3-butanediol, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl, 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol produce linear C8-C10 dicarbonates of general formula MeOC(O)O∼∼∼OC(O)OMe as the almost exclusive products. Of note, these dicarbonate derivatives are not otherwise accessible in good yields by other conventional base catalyzed methods. Among 1,3-diols, the only exception was 2-methyl 2,4-pentandiol that yields the corresponding cyclic carbonate, i.e. 4,4,6-trimethyl-1,3-dioxan-2-one. In no one case, polycarbonates are observed. Such remarkable differences of product distributions are ascribed to the structure (branching and relative position of OH groups) of diols and to the role of cooperative (nucleophilic and electrophilic) catalysis which has been proved for onium salts. The investigated carbonate salts are not only effective in amounts as low as 0.5 mol%, but they are highly stable and recyclable. PMID:24825024

  11. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    Science.gov (United States)

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g. PMID:27339313

  12. Synthesis and characterization of hyaluronic acid/human-like collagen hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jingjing; Ma, Xiaoxuan, E-mail: xiaoxuanma@163.com; Fan, Daidi, E-mail: fandaidi@nwu.edu.cn; Zhu, Chenhui; Deng, Jianjun; Hui, Junfeng; Ma, Pei

    2014-10-01

    Injectable hydrogel plays an important role in soft tissue filling and repair. We report an injectable hydrogel based on hyaluronic acid (HA) and human-like collagen (HLC), both with favorable biocompatibility and biodegradability. These two types of biomacromolecules were crosslinked with 1,4-butanediol diglycidyl ether to form a three-dimensional network. The redundant crosslinker was removed by dialysis and distillation. An HA-based hydrogel prepared by the same method was used as a control. The cytocompatibility was studied with a Cell Counting Kit-8 (CCK-8) test. Carbazole colorimetry was used to analyze the in vitro degradation rate. The histocompatibility was evaluated by hematoxylin and eosin (H and E) staining analysis and immunohistochemical analysis. The CCK-8 assay demonstrated that the HA/HLC hydrogel was less cytotoxic than the HA-based hydrogel and could promote baby hamster kidney cell (BHK) proliferation. The cell adhesion indicated that BHK could grow well on the surface of the materials and maintain good cell viability. The in vitro degradation test showed that the HA/HLC hydrogel had a longer degradation time and an excellent antienzyme ability. In vivo injection showed that there was little inflammatory response to HA/HLC after 1, 2, and 4 weeks. Therefore, the HA/HLC hydrogel is a promising biomaterial for soft tissue filling and repair. - Highlights: • Human-like collagen was used with hyaluronic acid to prepare soft tissue filling meterials. • 1,4-Butanediol diglycidyl ether (BDDE) was introduced to treat the hydrogels. • The addition of human-like collagen could improve the biological properties of hydrogels.

  13. Effects of various metabolites (sugars, carboxylic acids and alcohols) on riboflavin formation in non-growing cells of Ashbya gossypii.

    Science.gov (United States)

    Mitsuda, H; Nakajima, K; Ikeda, Y

    1978-01-01

    The effects of various sugars and sugar derivatives on flavinogenesis were examined using non-growing cells of a high flavinogenic mold, Ashbya gossypii. Glucose, fructose and galactose were found to be the most stimulative. Glycerol and glucono-delta-lactone were less stimulative; next in order were n-propanol, n-butanol, glycols and butanediols, which were likewise effective; acetate, lactate and pyruvate were slightly stimulative. In contrast, ribose, xylose, arabinose, ribitol, citrate, succinate, oxaloacetate, glyoxylate and malate were rather inhibitory, in additions at 1.0%. Among these compounds, ethanol (1%) greatly stimulated riboflavin formation. Maximum flavinogenesis with the above stimulants was attained by the additions of 1% ethanol, 1.25--3.0% glucose, 1.25% glycerol, 4.0--6.0% propane and butanediols, 1.0% pyruvate and 0.9% acetate after 37 hr incubation, respectively. These compounds inhibited flavinogenesis with increasing concentrations above their optimum concentrations. The stimulation effect of ethanol far exceeded those of other stimulants but ethanol had almost no effect on growth and pH values during incubation. With the addition of ethanol (1%) during incubation, maximum formation (1,776 microgram/g wet mycelia) of riboflavin was achieved when added at the start of incubation and the most effective utilization was observed when added at the logarithmic phase of flavinogenesis, although the maximum formation of riboflavin in the latter case was much lower than in the former case. The relation of sugar metabolism, especially ethanol metabolism, to flavinogenesis was discussed with the flavinogenic activities of these additives. PMID:27596

  14. Production of Chemical Derivatives from Renewables

    Energy Technology Data Exchange (ETDEWEB)

    Davison, Brian; Nghiem, John; Donnelly, Mark; Tsai, Shih-Perng; Frye, John; Landucci, Ron; Griffin, Michael

    1996-06-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corp., (LMER), Argonne National Laboratory (ANL), National Renewable Energy Laboratory (NREL), and Battelle Memorial Institute, operator of Pacific Northwest National Laboratory (PNNL), (collectively referred to as the 'Contractor'), and Applied Carbochemicals, Inc. (Participant) was to scale-up from bench results an economically promising and competitive process for the production of chemical derivatives from biologically produced succinic acid. The products that were under consideration for production from the succinic acid platform included 1,4-butanediol, {gamma}y-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Preliminary economic analyses indicated that this platform was competitive with the most recent petrochemical routes. The Contractors and participant are hereinafter jointly referred to as the 'Parties.' Research to date in succinic acid fermentation, separation and genetic engineering resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on preliminary laboratory findings and predicted catalytic parameters. At the time, the current need was to provide the necessary laboratory follow-up information to properly optimize, design and operate a pilot scale process. The purpose of the pilot work was to validate the integrated process, assure 'robustness' of the process, define operating conditions, and provide samples for potential customer evaluation. The data from the pilot scale process was used in design and development of a full scale production facility. A new strain, AFP111 (patented), discovered at ANL was tested and developed for process use at the Oak

  15. Moisture Absorption and Retention of Plysaccharides from Four Marine Shellfishes%4种海洋贝类多糖提取和保湿性研究

    Institute of Scientific and Technical Information of China (English)

    邓一清; 童银洪; 陈小丽; 梁飞龙; 杜晓东

    2012-01-01

    Polysaccharides were obtained from the whole viscera of marine shellfishes Pinctada martensii, Pteria penguin, Perna viridis and Crassostrea rivularis by hot water extraction. Moisture absorption of the polysaccharidc extractions from the four shellfishes were evaluated in contrast with traditional humectants such as glycerol, 1,3-butanediol, propanediol, PEG-400. At a relative humidity of 44%, the order of moisture absorption rate at 12 hours of the humectants was as follows: Pinctada martensii < Crassostrea rivularis< Pteria penguin < Perna viridis < PEG-400 < 1, 3-butanediol < glycerol < propanediol. At a relative humidity of 80%, the order of moisture absorption rate at 12 hours of the humectants listed as follows: Crassostrea rivularis < Pinctada martensii < Pteria penguin < 1,3-butanediol < Perna viridis < PEG-400 < glycerol Perna viridis > Pinctada martensii> Pteria penguin > glycerol > 1, 3-butanediol> propanediol > PEG-400. Moisture absorption rate of polysaccharide from Perna viridis was superior to the other shellfishes, and inferior to traditional humectants. Moisturizing retention rate of polysaccharide of Perna viridis was inferior to oyster, and superior to the others.%以马氏珠母贝(Pinctada martensii)、企鹅珍珠贝(Pteria penguin)、翡翠贻贝(Perna viridis)和近江牡蛎(oyster)的内脏团为原料提取、纯化多糖,与甘油、聚乙二醇400( PEG-400)、丙二醇和1,3-丁二醇四种常规保湿剂进行比较.结果表明,在相对湿度为44%时,前12h吸湿率顺序为:马氏珠母贝<近江牡蛎<企鹅珍珠贝<翡翠贻贝< PEG-400<1,3-丁二醇<甘油<丙二醇;在相对湿度为80%时,前12h吸湿率顺序为:近江牡蛎<马氏珠母贝<企鹅珍珠贝<1,3-丁二醇<翡翠贻贝< PEG-400<甘油<丙二醇.前12h的保湿率顺序为:近江牡蛎>翡翠贻贝>马氏珠母贝>企鹅珍珠贝>甘油>1,3-丁二醇>丙二醇> PEG-400.翡翠

  16. Study on Synthesis of Sodium 1,4-ButanedioI Bis-octafIuoropentyI SuIfo Succinate%1,4-丁二醇双琥珀酸八氟戊醇双酯磺酸钠的合成工艺研究

    Institute of Scientific and Technical Information of China (English)

    张国华; 顾菊香; 程希; 翁仪瑾; 刘洪颖

    2015-01-01

    采用八氟戊醇、马来酸酐、1,4-丁二醇为原料,合成了一种新型的双子表面活性剂—1,4-丁二醇双琥珀酸八氟戊醇双酯磺酸钠。通过实验得到各步反应的最优工艺条件,单酯化反应:马来酸酐与八氟戊醇摩尔比为1.2:1.0,加入占马来酸酐质量1%的无水乙酸钠,反应时间为4h,反应温度为90℃;双酯化反应:八氟戊醇马来酸单酯与1,4-丁二醇的摩尔比为2.1:1.0,占八氟戊醇马来酸单酯质量1.5%的对甲苯磺酸催化剂,反应温度为160℃,反应时间为7h;磺化反应:NaHSO3与1,4-丁二醇双马来酸八氟戊醇双酯摩尔比为1.0:2.2,反应温度为100℃,反应时间为6h。对终产物的性能进行测定,表面张力为:29.6 mN·m-1,CMC为0.005 g/L。%With eight fluorine amyl alcohol,maleic anhydride and 1,4 -butanediol as raw material,a new Gemini surfactants of sodium glycol bis-octafluoropentyl sulfo succinate was synthesized. The optimal reac-tion conditions were obtained through experiments as follow,for single esterification reaction,the molar ratio of maleic anhydride to eight fluorine amyl alcohol was 1. 2:1. 0 ,with anhydrous sodium acetate accounted for 1% of the mass of maleic anhydride as catalyst,reaction temperature e was 90℃ and reaction time was 4h;for the double-esterification reaction,the molar ratio of eight fluorine amyl alcohol maleic acid monoester to 1, 4-butanediol was 2. 1:1. 0 ,with p-toluenesulfonic acid accounted for 1. 5% of the mass of octafluoropenta-nol maleic acid monoester as catalyst,reaction temperature was 160℃ and reaction time was 7h;for sulfona-tion reaction:the molar ratio of NaHSO3 to 1 ,4-butanediol bis-maleic acid octafluoropentanol diester molar ratio was 1. 0:2. 2,the reaction temperature was 100℃ and the reaction time was 6h. Determination of the fi-nal product performance,surface tension:29. 6 mN m-1 ,CMC:0. 005 g/L.

  17. Dissolution Behaviors of Lignin and Carbohydrate in Bagasse during High Boiling Solvent Pretreatment%甘蔗渣高沸醇预处理过程中木质素和碳水化合物的溶出规律

    Institute of Scientific and Technical Information of China (English)

    王景全; 赵红; 胡湛波; 刘世锋; 胡会超; 柴欣生

    2011-01-01

    研究了甘蔗渣在1,4-丁二醇溶剂预处理过程中木质素、碳水化合物随保温温度和时间的溶出规律及其溶出反应动力学参数.结果表明,适合甘蔗渣1,4-丁二醇预处理的溶剂浓度为60%;在此条件下,木质素和碳水化合物的溶出反应均可分为大量溶出和残余溶出两个阶段;在这两个阶段,木质素溶出反应的活化能分别为98.6 kJ/mol和152.3 kJ/mol,碳水化合物溶出反应的活化能分别为117.4 kJ/mol和125.9 kJ/mol.当残余木质素量降至约为3.2%后,纤维素将发生严重降解.%This paper reports the kinetic dissolution behaviors of lignin and carbohydrate in bagasse during 1,4-butanediol pretreatment.The results showed the the solvent concentration of 60% is suitable,which will be economically feasible in consideration of the solvent recycling.The lignin and carbohdrate dissolution undergoes bulk and residual srages,the activation energies of those two stages for lignin are 98.6 and 152.3kJ/mol resoectively,and 117.4and 125.9kJ/mol for carbhydrate respectively.The cellulose will be degraded seriously when rhe content of lignin in the bagasse is reduced to less than 3.2%.This data are of certain guiding significance in optimzing the pretreatment process of bagasse biorefinery using 1,4-butanediol solvent.

  18. Determination of volatile aroma compounds in litchi vinegar by HS-SPME-GC/MS%顶空固相微萃取-气质联用测定荔枝果醋中挥发性成分

    Institute of Scientific and Technical Information of China (English)

    李巍青; 王浩; 蒋丽婷; 李理

    2011-01-01

    采用顶空固相微萃取结合气质联用法测定了荔枝果醋中的挥发性成分,共检测出34种物质,包括酸类、醇类、醛酮类、酯类、烃类化合物以及少量其它化合物.采用面积归一法进行分析可知:主要成分为醋酸(61.6%)、乙酸乙酯(7.91%)、3-羟基-2-丁酮(6.44%)、乙酸异戊酯(2.97%)、乙酸苯乙酯(2.87%)、邻苯二甲酸二异丁酯(2.25%)、(2R,3R)-(-)-2,3-丁二醇(2.09%)、醋酸异丁酯(1.74%)、2,3-丁二醇(1.61%)、辛酸乙酯(1.42%)、乙酸-2-甲基丁酯(1.37%)、乙醇(1.25%).%The volatile compounds of Litchi vinegar were extracted by solid phase micro extraction and were identified by the analysis of gas chro-matography-mass spectrometry. About 34 different components were identified including acids, alcohols, aldehydes, ketones, esters, hydrocarbons and a few other compounds. The percentage of each component was determined by area normalization. It was indicated that the main volatile components in the Litchi vinegar were acetic acid (61.6%), ethyl acetate (7.91%), 3-hydroxy-2-butanone (6.44%), isoamyl acetate (2.97%), phenethyl acetate (2.87%), diisobutyl phthalate (2.25%), (2R,3R)-(-)-2,3-butanediol (2.09%), isobutyl acetate (1.74%), 2,3-butanediol (1.61%), octanoic acid ethyl ester (1.42%), acetic acid 2-methylbutyl ester (1.37%), ethyl alcohol (1.25%).

  19. 碳酸乙二酯与二醇反应制备聚碳酸酯二元醇%Synthesis of Polycarbonate Diol Through the Reaction of Ethylene Carbonate with Diol

    Institute of Scientific and Technical Information of China (English)

    李金丽; 周宏勇; 李云庆; 王家喜

    2012-01-01

    A series of linear aliphatic polycarbonate diols (APC) with defined structure were synthesized by using ethylene carbonate (EC), 1,4-butanediol, and 1,6-hexanediol as the raw materials promoted by zinc acetate or zinc nitrate. The effect of reaction temperature, time and the amount of catalyst on the structure and number average molecular weight of polycarbonate was investigated. The structures and number average molecular weight were characterized and calculated by means of NMR spectroscopy. The number average molecular weight (Mn) of polycarbonate with l]-hydroxylethyl and/or c0-hydroxylalkyl as end groups is in range of 300 to 560 for reaction of 1, 4-butanediol and 700 to 980 for reaction of 1,6-hexanediol. The ether unit from the reaction of 1,4-butandiol can be less than 3%(mol). While the ether unit from the reaction of 1,6-hexandiol can be less up to 0.24% (tool). The reaction mechanism of ethylene carbonate with diol is proposed.%以碳酸乙二酯、1,4-丁二醇和1,6-己二醇为原料,醋酸锌、硝酸锌为催化剂,考察了反应温度、反应时间等条件对碳酸乙二酯与二元醇反应的影响,制备出结构规整的以β-羟乙基、ω-羟烷氧基为端基的聚碳酸酯二元醇。产物经核磁共振波谱表征,1,4-丁二醇反应的聚碳酸酯二元醇的数均分子量为300-560,产物中由脱羰基反应形成的醚键链段含量可小于3%,1,6-己二醇反应的聚碳酸酯二元醇的数均分子量为700-980,产物中醚键链段含量可降低至0.24%。最后探讨了碳酸乙二酯与二元醇的反应机理。

  20. Homolactic fermentation from glucose and cellobiose using Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Martinez Alfredo

    2009-04-01

    Full Text Available Abstract Backgroung Biodegradable plastics can be made from polylactate, which is a polymer made from lactic acid. This compound can be produced from renewable resources as substrates using microorganisms. Bacillus subtilis is a Gram-positive bacterium recognized as a GRAS microorganism (generally regarded as safe by the FDA. B. subtilis produces and secretes different kind of enzymes, such as proteases, cellulases, xylanases and amylases to utilize carbon sources more complex than the monosaccharides present in the environment. Thus, B. subtilis could be potentially used to hydrolyze carbohydrate polymers contained in lignocellulosic biomass to produce chemical commodities. Enzymatic hydrolysis of the cellulosic fraction of agroindustrial wastes produces cellobiose and a lower amount of glucose. Under aerobic conditions, B. subtilis grows using cellobiose as substrate. Results In this study, we proved that under non-aerated conditions, B. subtilis ferments cellobiose to produce L-lactate with 82% of the theoretical yield, and with a specific rate of L-lactate production similar to that one obtained fermenting glucose. Under fermentative conditions in a complex media supplemented with glucose, B. subtilis produces L-lactate and a low amount of 2,3-butanediol. To increase the L-lactate production of this organism, we generated the B subtilis CH1 alsS- strain that lacks the ability to synthesize 2,3-butanediol. Inactivation of this pathway, that competed for pyruvate availability, let a 15% increase in L-lactate yield from glucose compared with the parental strain. CH1 alsS- fermented 5 and 10% of glucose to completion in mineral medium supplemented with yeast extract in four and nine days, respectively. CH1 alsS- produced 105 g/L of L-lactate in this last medium supplemented with 10% of glucose. The L-lactate yield was up to 95% using mineral media, and the optical purity of L-lactate was of 99.5% since B. subtilis has only one gene (lctE that

  1. Water-enhanced solvation of organics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H.

    1993-07-01

    Water-enhanced solvation (WES) was explored for Lewis acid solutes in Lewis base organic solvents, to develop cheap extract regeneration processes. WES for solid solutes was determined from ratios of solubilities of solutes in water-sat. and low-water solvent; both were determined from solid-liquid equilibrium. Vapor-headspace analysis was used to determine solute activity coefficients as function of organic phase water concentration. WES magnitudes of volatile solutes were normalized, set equal to slope of log {gamma}{sub s} vs x{sub w}/x{sub s} curve. From graph shape {Delta}(log {gamma}{sub s}) represents relative change in solute activity coefficient. Solutes investigated by vapor-headspace analysis were acetic acid, propionic acid, ethanol, 1,2-propylene glycol, 2,3-butylene glycol. Monocarboxylic acids had largest decrease in activity coefficient with water addition followed by glycols and alcohols. Propionic acid in cyclohexanone showed greatest water-enhancement {Delta} (log {gamma}{sub acid})/{Delta}(x{sub w}/x{sub acid}) = {minus}0.25. In methylcyclohexanone, the decrease of the activity coefficient of propionic acid was {minus}0.19. Activity coefficient of propionic acid in methylcyclohexanone stopped decreasing once the water reached a 2:1 water to acid mole ratio, implying a stoichiometric relation between water, ketone, and acid. Except for 2,3-butanediol, activity coefficients of the solutes studied decreased monotonically with water content. Activity coefficient curves of ethanol, 1,2-propanediol and 2,3-butanediol did not level off at large water/solute mole ratio. Solutes investigated by solid-liquid equilibrium were citric acid, gallic acid, phenol, xylenols, 2-naphthol. Saturation concentration of citric acid in anhydrous butyl acetate increased from 0.0009 to 0.087 mol/L after 1.3 % (g/g) water co-dissolved into organic phase. Effect of water-enhanced solvation for citric acid is very large but very small for phenol and its derivatives.

  2. Contribution of Liver Alcohol Dehydrogenase to Metabolism of Alcohols in Rats

    Science.gov (United States)

    Plapp, Bryce V.; Leidal, Kevin G.; Murch, Bruce P.; Green, David W.

    2015-01-01

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5–20 mmole/kg. Ethanol was eliminated most rapidly, at 7.9 mmole/kg•h. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5–10 mmole/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmole/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6 ± 1 mmole/kg•h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD+ for the conversion to ketones whereas primary alcohols require two equivalents of NAD+ for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD+ is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

  3. A comparative transcriptomic, fluxomic and metabolomic analysis of the response of Saccharomyces cerevisiae to increases in NADPH oxidation

    Directory of Open Access Journals (Sweden)

    Celton Magalie

    2012-07-01

    Full Text Available Abstract Background Redox homeostasis is essential to sustain metabolism and growth. We recently reported that yeast cells meet a gradual increase in imposed NADPH demand by progressively increasing flux through the pentose phosphate (PP and acetate pathways and by exchanging NADH for NADPH in the cytosol, via a transhydrogenase-like cycle. Here, we studied the mechanisms underlying this metabolic response, through a combination of gene expression profiling and analyses of extracellular and intracellular metabolites and 13 C-flux analysis. Results NADPH oxidation was increased by reducing acetoin to 2,3-butanediol in a strain overexpressing an engineered NADPH-dependent butanediol dehydrogenase cultured in the presence of acetoin. An increase in NADPH demand to 22 times the anabolic requirement for NADPH was accompanied by the intracellular accumulation of PP pathway metabolites consistent with an increase in flux through this pathway. Increases in NADPH demand were accompanied by the successive induction of several genes of the PP pathway. NADPH-consuming pathways, such as amino-acid biosynthesis, were upregulated as an indirect effect of the decrease in NADPH availability. Metabolomic analysis showed that the most extreme modification of NADPH demand resulted in an energetic problem. Our results also highlight the influence of redox status on aroma production. Conclusions Combined 13 C-flux, intracellular metabolite levels and microarrays analyses revealed that NADPH homeostasis, in response to a progressive increase in NADPH demand, was achieved by the regulation, at several levels, of the PP pathway. This pathway is principally under metabolic control, but regulation of the transcription of PP pathway genes can exert a stronger effect, by redirecting larger amounts of carbon to this pathway to satisfy the demand for NADPH. No coordinated response of genes involved in NADPH metabolism was observed, suggesting that yeast has no system for

  4. Electrochemical sensing of H2O2 by the modified electrode with pd nanoparticles on multi-walled carbon nanotubes-g-poly(lactic acid).

    Science.gov (United States)

    Han, Hyoung Soon; You, Jung-Min; Jeong, Haesang; Jeon, Seungwon

    2014-06-01

    A simple method has adapted to prepare MWCNT grafted Poly(lactic acid) (MWCNT-g-PLA) by intercalative polymerization of poly(lactic acid) in the presence of multi-wall carbon nanotubes (MWCNT) functionalized with hydroxyl groups. The functionalized MWCNT has obtained from the treatment of methylene diphenyl diisocyanate (MDI) with MWCNT, and then the reaction with 1,4-butanediol (BD) to create functional hydroxyl groups. MWCNT-g-PLA-Pd and MWCNT-g-PLA-Pt have prepared from the MWCNT-g-PLA and metal precursors. The synthesized materials have characterized by 1H-NMR, Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM). The MWCNT-g-PLA-Pd is possibilities for employing to electrochemical detection of hydrogen peroxide. Electrocatalytic activities are verified from cyclic voltammetry (CV) and amperometric response in 0.1 M phosphate buffer solution (PBS). The biosensor provided good stability and selectivity towards interferences such as UA, AA, and glucose. PMID:24738350

  5. Nutritional Value and Volatile Compounds of Black Cherry (Prunus serotina Seeds

    Directory of Open Access Journals (Sweden)

    Leticia García-Aguilar

    2015-02-01

    Full Text Available Prunus serotina (black cherry, commonly known in Mexico as capulín, is used in Mexican traditional medicine for the treatment of cardiovascular, respiratory, and gastrointestinal diseases. Particularly, P. serotina seeds, consumed in Mexico as snacks, are used for treating cough. In the present study, nutritional and volatile analyses of black cherry seeds were carried out to determine their nutraceutical potential. Proximate analysis indicated that P. serotina raw and toasted seeds contain mostly fat, followed by protein, fiber, carbohydrates, and ash. The potassium content in black cherry raw and toasted seeds is high, and their protein digestibility-corrected amino acid scores suggest that they might represent a complementary source of proteins. Solid phase microextraction and gas chromatography/flame ionization detection/mass spectrometry analysis allowed identification of 59 and 99 volatile compounds in the raw and toasted seeds, respectively. The major volatile compounds identified in raw and toasted seeds were 2,3-butanediol and benzaldehyde, which contribute to the flavor and odor of the toasted seeds. Moreover, it has been previously demonstrated that benzaldehyde possesses a significant vasodilator effect, therefore, the presence of this compound along with oleic, linoleic, and α-eleostearic fatty acids indicate that black cherry seeds consumption might have beneficial effects on the cardiovascular system.

  6. Prepared polymethacrylate-based monoliths for the separation of cations by non-suppressed capillary ion chromatography.

    Science.gov (United States)

    Li, Jing; Zhu, Yan

    2014-01-01

    This paper describes a novel analytical system for non-suppressed capillary ion chromatography. Methacrylate monolithic columns were prepared from silanized fused-silica capillaries of 320 µm i.d. by in situ polymerization of glycidyl methacrylate and ethylene dimethacrylate in the presence of 1,4-butanediol, 1-propanol and water as the porogen solvents. The introduction of cation-exchange sites was achieved by sulfonating the matrix with sodium sulfite to produce total cation-exchange capacities in the range of 45-105 μequiv/mL for a 25 cm column. The conditions (concentrations of sodium sulfite solution, reacting time and modified flow rate) of sulfonation were optimized. The hydrodynamic and chromatographic performances were estimated. Coupled with a conductivity detector, a capillary ion chromatography system was set up with the prepared column. Finally, the resultant column was used for the separations of five common univalent cations (Li(+), Na(+), NH4(+), K(+) and Cs(+)) using methanesulfonic acid as the eluent and four divalent cations (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) by non-suppressed capillary ion chromatography; the chromatographic parameters were further researched.

  7. TOPEM DSC study of glass transition region of polyurethane cationomers

    International Nuclear Information System (INIS)

    Highlights: ► TOPEM DSC method was employed to investigate the glass transition (Tg) region of fluorinated polyurethane cationomers. ► Introduction of fluorine compounds significantly changes thermal behaviour of cationomers in the Tg region of hard segments. ► Introduction of fluorine compound leads to changes of the slope in activation diagram of glass transition. - Abstract: In this paper TOPEM DSC method was employed to investigate the glass transition region of fluorinated polyurethane cationomers. Fluorinated polyurethane cationomers have been synthesised in the reaction of MDI with poly(ethylene glycol) (600) and butane1,4-diol or N-methyl- or N-butyldiethanolamine and 2,2,3,3-tetrafluoro-1,4-butanediol. Better rigidity was found for generally amorphous cationomer coats. It was found that introduction of fluorine compound changes thermal behaviour of polyurethane cationomers as well as leads to changes in the slope in activation diagram profiles of glass transition in comparison to polyuretahene cationomer without fluorine compound. Application of TOPEM DSC allows to obtain more information concerning frequency dependence of glass transition region and thermodynamical stability of polyurethane structures.

  8. Biodegradable products by lipase biocatalysis.

    Science.gov (United States)

    Linko, Y Y; Lämsä, M; Wu, X; Uosukainen, E; Seppälä, J; Linko, P

    1998-11-18

    The interest in the applications of biocatalysis in organic syntheses has rapidly increased. In this context, lipases have recently become one of the most studied groups of enzymes. We have demonstrated that lipases can be used as biocatalyst in the production of useful biodegradable compounds. A number of examples are given. 1-Butyl oleate was produced by direct esterification of butanol and oleic acid to decrease the viscosity of biodiesel in winter use. Enzymic alcoholysis of vegetable oils without additional organic solvent has been little investigated. We have shown that a mixture of 2-ethyl-1-hexyl esters can be obtained in a good yield by enzymic transesterification from rapeseed oil fatty acids for use as a solvent. Trimethylolpropane esters were also similarly synthesized as lubricants. Finally, the discovery that lipases can also catalyze ester syntheses and transesterification reactions in organic solvent systems has opened up the possibility of enzyme catalyzed production of biodegradable polyesters. In direct polyesterification of 1,4-butanediol and sebacic acid, polyesters with a mass average molar mass of the order of 56,000 g mol-1 or higher, and a maximum molar mass of about 130,000 g mol-1 were also obtained by using lipase as biocatalyst. Finally, we have demonstrated that also aromatic polyesters can be synthesized by lipase biocatalysis, a higher than 50,000 g mol-1 mass average molar mass of poly(1,6-hexanediyl isophthalate) as an example. PMID:9866859

  9. Catalysis for biomass and CO2 use through solar energy: opening new scenarios for a sustainable and low-carbon chemical production.

    Science.gov (United States)

    Lanzafame, Paola; Centi, Gabriele; Perathoner, Siglinda

    2014-11-21

    The use of biomass, bio-waste and CO2 derived raw materials, the latter synthesized using H2 produced using renewable energy sources, opens new scenarios to develop a sustainable and low carbon chemical production, particularly in regions such as Europe lacking in other resources. This tutorial review discusses first this new scenario with the aim to point out, between the different possible options, those more relevant to enable this new future scenario for the chemical production, commenting in particular the different drivers (economic, technological and strategic, environmental and sustainability and socio-political) which guide the selection. The case of the use of non-fossil fuel based raw materials for the sustainable production of light olefins is discussed in more detail, but the production of other olefins and polyolefins, of drop-in intermediates and other platform molecules are also analysed. The final part discusses the role of catalysis in establishing this new scenario, summarizing the development of catalysts with respect to industrial targets, for (i) the production of light olefins by catalytic dehydration of ethanol and by CO2 conversion via FTO process, (ii) the catalytic synthesis of butadiene from ethanol, butanol and butanediols, and (iii) the catalytic synthesis of HMF and its conversion to 2,5-FDCA, adipic acid, caprolactam and 1,6-hexanediol. PMID:24577063

  10. Surface Tension of Alcohols. Data Selection and Recommended Correlations

    Science.gov (United States)

    Mulero, A.; Cachadiña, I.; Sanjuán, E. L.

    2015-09-01

    In previous papers, we have proposed specific correlations to reproduce the surface tension values for several sets of fluids and for wide ranges of temperatures. In this paper, we focus our attention on alcohols and consider the available data for 152 fluids grouped into five families. We use the most recent versions of the DIPPR and DETHERM databases and also Wohlfarth and Wohlfarth's (1997) book as our main sources of data. In some cases we have also considered new data. All the data have been carefully filtered in order to discard those that are in clear disagreement with most of the available data for the same fluid. In some cases, two or more different data sets versus temperature trends were observed, and where possible we considered only one of these trends. To fit the finally selected data, we used the model currently implemented in National Institute of Standards and Technology's refprop program, calculating two, four, or six adjustable coefficients for each fluid. As a result, we proposed recommended correlations for 147 alcohols, providing mean average percentage deviations below 1.7% for each fluid, with only two exceptions: 1,2-butanediol (2.77%) and benzyl alcohol (3.20%).

  11. Identification and quantification of the main organic components of vinegars by high resolution {sup 1}H NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Caligiani, A. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy)]. E-mail: augusta.caligiani@unipr.it; Acquotti, D. [Centro Interfacolta Misure, Universita degli Studi di Parma, Via Usberti 23A, 43100-Parma (Italy); Palla, G. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy); Bocchi, V. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy)

    2007-02-28

    A detailed analysis of the proton high-field NMR spectra of vinegars (in particular of Italian balsamic vinegars) is reported. A large number of organic substances belonging to different classes, such as carbohydrates, alcohols, organic acids, volatile compounds and amino acids, were assigned. The possibility of quantification of the substances identified in the whole vinegar sample, without extraction or pre-concentration steps, was also tested. The data validity was demonstrated in terms of precision, accuracy, repeatability and inter-day reproducibility. The effects of the most critical experimental parameters (sample concentration, water suppression and relaxation time) on the analysis response were also discussed. {sup 1}H NMR results were compared with those obtained by traditional techniques (GC-MS, titrations), and good correlations were obtained. The results showed that {sup 1}H NMR with water suppression allows a rapid, simultaneous determination of carbohydrates (glucose and fructose), organic acids (acetic, formic, lactic, malic, citric, succinic and tartaric acids), alcohols and polyols (ethanol, acetoin, 2,3-butanediol, hydroxymethylfurfural), and volatile substances (ethyl acetate) in vinegar samples. On the contrary, the amino acid determination without sample pre-concentration was critical. The {sup 1}H NMR method proposed was applied to different samples of vinegars, allowing, in particular, the discrimination of vinegars and balsamic vinegars.

  12. Affinity chromatography for the purification of therapeutic proteins from transgenic maize using immobilized histamine.

    Science.gov (United States)

    Platis, Dimitris; Labrou, Nikolaos E

    2008-03-01

    Plant molecular pharming is a technology that uses plants as bioreactors to produce recombinant molecules of medical and veterinary importance. In the present study, we evaluated the ability of histamine (HIM), tryptamine (TRM), phenylamine (PHEM) and tyramine (TYRM) coupled to Sepharose CL-4B via a 1,4-butanediol diglycidyl ether spacer to bind and purify human monoclonal anti-HIV antibody 2F5 (mAb 2F5) from spiked maize seed and tobacco leaf extracts. Detailed studies were carried out to determine the factors that affect the chromatographic behaviour of mAb 2F5 and also maize seed and tobacco leaf proteins. All affinity adsorbents showed a reduced capacity to bind and a reduced ability to purify proteins from tobacco extract compared to maize extract. Under optimal conditions, HIM exhibited high selectivity for mAb 2F5 and allowed a high degree of purification (>95% purity) and recovery (>90%) in a single step with salt elution (0.4 M KCl) from spiked maize seed extract. Analysis of the purified antibody fraction by ELISA and Western blot showed that the antibody was fully active and free of degraded variants or modified forms. The efficacy of the system was assessed further using a second therapeutic antibody (human monoclonal anti-HIV antibody mAb 2G12) and a therapeutic enzyme (alpha-chymotrypsin). HIM may find application in the purification of a wide range of biopharmaceuticals from transgenic plants. PMID:18307162

  13. 2-Butanol and butanone production in Saccharomyces cerevisiae through combination of a B12 dependent dehydratase and a secondary alcohol dehydrogenase using a TEV-based expression system.

    Directory of Open Access Journals (Sweden)

    Payam Ghiaci

    Full Text Available 2-Butanol and its chemical precursor butanone (methyl ethyl ketone--MEK are chemicals with potential uses as biofuels and biocommodity chemicals. In order to produce 2-butanol, we have demonstrated the utility of using a TEV-protease based expression system to achieve equimolar expression of the individual subunits of the two protein complexes involved in the B12-dependent dehydratase step (from the pdu-operon of Lactobacillus reuteri, which catalyze the conversion of meso-2,3-butanediol to butanone. We have furthermore identified a NADH dependent secondary alcohol dehydrogenase (Sadh from Gordonia sp. able to catalyze the subsequent conversion of butanone to 2-butanol. A final concentration of 4±0.2 mg/L 2-butanol and 2±0.1 mg/L of butanone was found. A key factor for the production of 2-butanol was the availability of NADH, which was achieved by growing cells lacking the GPD1 and GPD2 isogenes under anaerobic conditions.

  14. Synthesis of polycarbonate urethane elastomers and effects of the chemical structures on their thermal, mechanical and biocompatibility properties.

    Science.gov (United States)

    Zhu, Rong; Wang, Yiyu; Zhang, Zongrui; Ma, Daiwei; Wang, Xinyu

    2016-06-01

    In this study, to obtain biomedical polyurethane elastomers with good mechanical properties and biocompatibility, a series of polycarbonate urethanes were synthesized via a two-step solution of polymerization method using the poly(1,6-hexanediol)carbonate diols (PCDL) as the soft segment, 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI), 1,6-hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO) as the hard segment with dibutyltin dilaurate as the catalyst. In this article, we illustrated the physical behaviors were obviously influenced by synthetic routes. And their chemical and physical structures were investigated by gel permeation chromatograph (GPC), differential scanning calorimeter (DSC), fourier transform infrared spectrography (FT-IR) and mechanical properties tests. The surface wettability were studied by contact angle measurement (CA). As a kind of short-term implant biomaterial, the results of the hemolysis and platelet adhesive tests were recorded by spectrophotometer and scanning electron microscopy (SEM), indicating the materials have a great potential for developments and applications in biomedical field. PMID:27441296

  15. Polyurethane/fluor-hydroxyapatite nanocomposite scaffolds for bone tissue engineering. Part I: morphological, physical, and mechanical characterization.

    Science.gov (United States)

    Asefnejad, Azadeh; Behnamghader, Aliasghar; Khorasani, Mohammad Taghi; Farsadzadeh, Babak

    2011-01-01

    In this study, new nano-fluor-hydroxyapatite (nFHA)/polyurethane composite scaffolds were fabricated for potential use in bone tissue engineering. Polyester urethane samples were synthesized from polycaprolactone, hexamethylene diisocyanate, and 1,4-butanediol as chain extender. Nano fluor-hydroxyapatite (nFHA) was successfully synthesized by sol-gel method. The solid-liquid phase separation and solvent sublimation methods were used for preparation of the porous composites. Mechanical properties, chemical structure, and morphological characteristics of the samples were investigated by compressive test, Fourier transform infrared, and scanning electron microscopy (SEM) techniques, respectively. The effect of nFHA powder content on porosity and pore morphology was investigated. SEM images demonstrated that the scaffolds were constituted of interconnected and homogeneously distributed pores. The pore size of the scaffolds was in the range 50-250 μm. The result obtained in this research revealed that the porosity and pore average size decreased and compressive modulus increased with nFHA percentage. Considering morphological, physical, and mechanical properties, the scaffold with a higher ratio of nFHA has suitable potential use in tissue regeneration.

  16. Polyurethane/fluor-hydroxyapatite nanocomposite scaffolds for bone tissue engineering. Part I: morphological, physical, and mechanical characterization

    Directory of Open Access Journals (Sweden)

    Azadeh Asefnejad

    2011-01-01

    Full Text Available Azadeh Asefnejad1, Aliasghar Behnamghader2, Mohammad Taghi Khorasani3, Babak Farsadzadeh11Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran; 2Materials and Energy Research Center, Tehran, Iran; 3Iran Polymer and Petrochemical Institute, Tehran, IranAbstract: In this study, new nano-fluor-hydroxyapatite (nFHA/polyurethane composite scaffolds were fabricated for potential use in bone tissue engineering. Polyester urethane samples were synthesized from polycaprolactone, hexamethylene diisocyanate, and 1,4-butanediol as chain extender. Nano fluor-hydroxyapatite (nFHA was successfully synthesized by sol-gel method. The solid–liquid phase separation and solvent sublimation methods were used for preparation of the porous composites. Mechanical properties, chemical structure, and morphological characteristics of the samples were investigated by compressive test, Fourier transform infrared, and scanning electron microscopy (SEM techniques, respectively. The effect of nFHA powder content on porosity and pore morphology was investigated. SEM images demonstrated that the scaffolds were constituted of interconnected and homogeneously distributed pores. The pore size of the scaffolds was in the range 50–250 µm. The result obtained in this research revealed that the porosity and pore average size decreased and compressive modulus increased with nFHA percentage. Considering morphological, physical, and mechanical properties, the scaffold with a higher ratio of nFHA has suitable potential use in tissue regeneration.Keywords: polyester urethane, composite, fluor-hydroxyapatite, scaffold

  17. Revealing the morphological architecture of a shape memory polyurethane by simulation

    Science.gov (United States)

    Hu, Jinlian; Zhang, Cuili; Ji, Fenglong; Li, Xun; Han, Jianping; Wu, You

    2016-01-01

    The lack of specific knowledge of the network structure in shape memory polymers (SMPs) has prevented us from gaining an in-depth understanding of their mechanisms and limited the potential for materials innovation. This paper firstly reveals the unit-cell nanoscale morphological architecture of SMPs by simulation. The phase separated architecture of a segmented shape memory polyurethane (SMPU) with a 30 wt% hard segment content (HSC, 4,4’-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO)) showing good shape memory properties was investigated by dissipative particle dynamics (DPD) simulations. A linked-spherical netpoint-frame phase of MDI, a matrix-switch phase of polycaprolactone (PCL) and a connected-spider-like interphase for BDO were obtained for this SMPU. The BDO interphase can reinforce the MDI network. Based on these simulation results, a three-dimensional (3D) overall morphological architectural model of the SMPU can be established. This theoretical study has verified, enriched and integrated two existing schematic models: one being the morphological model deduced from experiments and the other the frame model for SMPs reported before. It can serve as a theoretical guide for smart polymeric materials design. This method for the simulation of polymer structure at the nanoscale can be extended to many areas such as photonic crystals where nanoscale self-assembly plays a vital role. PMID:27373495

  18. Exploring mild enzymatic sustainable routes for the synthesis of bio-degradable aromatic-aliphatic oligoesters.

    Science.gov (United States)

    Pellis, Alessandro; Guarneri, Alice; Brandauer, Martin; Acero, Enrique Herrero; Peerlings, Henricus; Gardossi, Lucia; Guebitz, Georg M

    2016-05-01

    The application of Candida antarctica lipase B in enzyme-catalyzed synthesis of aromatic-aliphatic oligoesters is here reported. The aim of the present study is to systematically investigate the most favorable conditions for the enzyme catalyzed synthesis of aromatic-aliphatic oligomers using commercially available monomers. Reaction conditions and enzyme selectivity for polymerization of various commercially available monomers were considered using different inactivated/activated aromatic monomers combined with linear polyols ranging from C2 to C12 . The effect of various reaction solvents in enzymatic polymerization was assessed and toluene allowed to achieve the highest conversions for the reaction of dimethyl isophthalate with 1,4-butanediol and with 1,10-decanediol (88 and 87% monomer conversion respectively). Mw as high as 1512 Da was obtained from the reaction of dimethyl isophthalate with 1,10-decanediol. The obtained oligomers have potential applications as raw materials in personal and home care formulations, for the production of aliphatic-aromatic block co-polymers or can be further functionalized with various moieties for a subsequent photo- or radical polymerization. PMID:26762794

  19. Oligoesters and polyesters produced by the curing of sunflower oil epoxidized biodiesel with cis-cyclohexane dicarboxylic anhydride: Synthesis and characterization

    International Nuclear Information System (INIS)

    Oligoesters and polyesters produced from sunflower oil biodiesel were synthesized and characterized. The polymers were obtained through the reaction of fatty acid methyl epoxy esters (EE) with cis-1,2-cyclohexane dicarboxylic anhydride (CH) and triethylamine (TEA) as initiator. Some reactions were conducted by adding small amounts of 1,4-butanediol diglycidyl ether (BDGE). The intermediate products of the synthesis process, including sunflower oil, methyl ester, epoxidised methyl esters, and the oligoesters and polyesters produced, were followed by Fourier Transform Infrared Spectroscopy and 1H and 13C nuclear magnetic resonance. The products obtained from the curing of the epoxidised esters with different compositions present similar chemical structures; however, they still depend on the amount of the epoxy resin BDGE that was added in the polymerization reaction. Thermoplastic materials with molecular weights (MW) starting at 3800 g/mol and reaching very high MWs, resulted in cross linked polymers. The thermal behaviour of the different products was investigated using differential scanning calorimetry and thermogravimetric analyses. The presence of BDGE in the structure of the materials increases the bonding capacity, resulting in higher molecular weight materials, which present good thermal stability.

  20. On-line detection of illicit substances in liquid phase with proton-transfer-reaction mass spectrometry (PTR-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Juerschik, Simone; Agarwal, Bishu; Petersson, Fredrik [Institut fuer Ionenphysik und Angewandte Physik, Universitaet Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); Sulzer, Philipp; Haidacher, Stefan; Jordan, Alfons; Schottkowsky, Ralf; Hartungen, Eugen; Hanel, Gernot; Seehauser, Hans; Maerk, Lukas [IONICON Analytik GmbH, Eduard-Bodem-Gasse 3, 6020 Innsbruck (Austria); Maerk, Tilmann D. [Institut fuer Ionenphysik und Angewandte Physik, Universitaet Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); IONICON Analytik GmbH, Eduard-Bodem-Gasse 3, 6020 Innsbruck (Austria)

    2011-07-01

    The direct aqueous injection (DAI) technique was recently utilized for the detection of illicit substances in liquid phase. DAI turns out to be an ideal solution for direct analysis of liquid samples, since we can make good use of the outstanding advantages, such as real-time analysis, no sample preparation, low detection limits and short response time. Differences in TNT concentration in the water could be seen dependent on time and original size of the pieces and we could demonstrate a linear correlation between the concentration in liquid and the PTR-MS signal. Furthermore, we were also able to demonstrate that this method is capable of detecting minute traces of ''rape drugs'', i.e. {gamma}-butyrolactone and 1,4-butanediol, in liquids. This new method achieving sensitivities in the around 100 pptw range appears therefore well suited for the fight against drug crime and terrorism and for the evaluation of contamination of ammunition dumping sites.

  1. Preparation and characterization of biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids via in situ melt polycondensation

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Bing Tao Wang; Zheng Hong Guo; Jie Chen; Zheng Ping Fang

    2009-01-01

    In situ melt polycondensation was proposed to prepare biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids based on terephthalic acid (TPA), poly(L-lactic acid) oligomer (OLLA), 1,4-butanediol (BDO) and nano-SiO_2. TEM and FT-IR characterizations confirmed that TPA, OLLA and BDO copolymerized to obtain biodegradable copolyesters, poly(butylene terephthalate-co-lactate) (PBTL), and the abundant hydroxyl groups on the surface of nano-SiO_2 provided potential sites for in situ grafting with the simultaneous resulted PBTL. The nano-SiO_2 particles were chemically wrapped with PBTL to form PBTL/nano-SiO2 hybrids. Due to the good dispersion and interfacial adhesion of nano-SiO_2 particles with the copolyester matrix, the tensile strength and the Young's modulus increased from 5.4 and 5.6 Mpa for neat PBTL to 16 and 390 Mpa for PBTL/nano-SiO_2 hybrids with 5 wt.% nano-SiO_2, respectively. The mechanical properties of PBTL/nano-SiO_2 hybrids were substantially improved.

  2. Synthesis and Characterisation of Bis-azido Methyl Oxetane and its Polymer and Copolymer with Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    J. K. Nair

    2002-04-01

    Full Text Available Bis-azido methyl oxetane (BAMO was synthesised from pentaerythritol in two steps. Pentaerythritol was chlorinated to yield a mixture of mono, di, tri and tetra chloro compounds. The trichloro compound on ring closure gives bis-chloro methyl oxetane (BCMO. It was reacted with sodium azide in aqueous medium to obtain BAMO. The latter was polymerised using BF3 etherate catalyst and 1,4-butanediol initiator. Similarly, the BAMO- THF copolymer was also synthesised. All the monomers and polymers were characterised by IR, 1H-NMR, 13C-NMR, and refractive index. The polymers were also characterised for molecular weight, hydroxyl value, etc. Thermal analysis showed that both polymers degrade exothermically with T max of 237 °C for poly BAMO and 241°C for BAMO- THF copolymer with activation energy of 39 kcal/mol and 40 kcal/mol, respectively. Explosive properties like impact and friction sensitivity of BAMO and the other polymers were also determined.

  3. Synthesis and characterization of shape-memory poly carbonate urethane microspheres for future vascular embolization.

    Science.gov (United States)

    Liu, Rongrong; Dai, Honglian; Zhou, Qian; Zhang, Qian; Zhang, Ping

    2016-08-01

    Two types of shape memory poly carbonate urethanes (PCUs) microspheres were synthesized by pre-polymerization and suspension polymerization, based on Polycarbonate diol (PCDL) as the soft segment, Isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) as the hard segments and 1,4-butanediol (BDO) as the chain expanding agent. The structure, crystallinity, and thermal property of the two synthesized PCUs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Differential scanning calorimetery (DSC), respectively. The results showed that the two types of PCUs exhibited high thermal stability with phase separation and semi-crystallinity. Also, the results of the compression test displayed that the shape fixity and the shape recovery of two PCUs were more than 90% compared to the originals, indicating their similar bio-applicability and shape-memory properties. The tensile strength, elongation at break was enhanced by introducing and increasing content of HDI. The water contact angles of PCUs decreased and their surface tension increased by surface modified with Bovine serum albumin (BSA). Furthermore, the biological study results of two types of PCUs from the platelet adhesion test and the cell proliferation inhibition test indicated they had some biocompatibilites. Hence, the PCU microspheres might represent a smart and shape-memory embolic agent for vascular embolization. PMID:27193120

  4. SYNTHESIS AND APPLICATION AS POLYMER ELECTROLYTE OF HOMO- AND COPOLYMERS OF 3-(2-CYANO ETHOXY)METHYL- AND 3-(METHOXY(TRIETHYLENOXY))METHYL-3'-METHYLOXETANE

    Institute of Scientific and Technical Information of China (English)

    Lin Ye; Zeng-guo Feng; Xiao-wen Zhang; Qian Qin; Ying Bai; Feng Wu; Shi Chen; Guo-qing Wang

    2006-01-01

    Two oxetane-derived monomers, 3-(2-cyano-ethoxy)methyl- and 3-(methoxy-(triethylenoxy))methyl-3'-methyloxetane (COX and MTOX), were prepared from 3-hydroxymethyl-3'-methyloxetane. Their homo- and co-polymerization in solution were carried out by the cationic ring-opening polymerization with BF3 · Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end (ACE) and activated monomer (AM) mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using 1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data.When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10-3.58 S/em at 30℃ and 10-2.73 S/cm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.

  5. Whole genome analysis of halotolerant and alkalotolerant plant growth-promoting rhizobacterium Klebsiella sp. D5A.

    Science.gov (United States)

    Liu, Wuxing; Wang, Qingling; Hou, Jinyu; Tu, Chen; Luo, Yongming; Christie, Peter

    2016-01-01

    This research undertook the systematic analysis of the Klebsiella sp. D5A genome and identification of genes that contribute to plant growth-promoting (PGP) traits, especially genes related to salt tolerance and wide pH adaptability. The genome sequence of isolate D5A was obtained using an Illumina HiSeq 2000 sequencing system with average coverages of 174.7× and 200.1× using the paired-end and mate-pair sequencing, respectively. Predicted and annotated gene sequences were analyzed for similarity with the Kyoto Encyclopedia of Genes and Genomes (KEGG) enzyme database followed by assignment of each gene into the KEGG pathway charts. The results show that the Klebsiella sp. D5A genome has a total of 5,540,009 bp with 57.15% G + C content. PGP conferring genes such as indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, siderophore production, acetoin and 2,3-butanediol synthesis, and N2 fixation were determined. Moreover, genes putatively responsible for resistance to high salinity including glycine-betaine synthesis, trehalose synthesis and a number of osmoregulation receptors and transport systems were also observed in the D5A genome together with numerous genes that contribute to pH homeostasis. These genes reveal the genetic adaptation of D5A to versatile environmental conditions and the effectiveness of the isolate to serve as a plant growth stimulator. PMID:27216548

  6. Genome Sequencing of a Mung Bean Plant Growth Promoting Strain of P. aeruginosa with Biocontrol Ability

    Directory of Open Access Journals (Sweden)

    Devaraj Illakkiam

    2014-01-01

    Full Text Available Pseudomonas aeruginosa PGPR2 is a mung bean rhizosphere strain that produces secondary metabolites and hydrolytic enzymes contributing to excellent antifungal activity against Macrophomina phaseolina, one of the prevalent fungal pathogens of mung bean. Genome sequencing was performed using the Ion Torrent Personal Genome Machine generating 1,354,732 reads (6,772,433 sequenced bases achieving ~25-fold coverage of the genome. Reference genome assembly using MIRA 3.4.0 yielded 198 contigs. The draft genome of PGPR2 encoded 6803 open reading frames, of which 5314 were genes with predicted functions, 1489 were genes of known functions, and 80 were RNA-coding genes. Strain specific and core genes of P. aeruginosa PGPR2 that are relevant to rhizospheric habitat were identified by pangenome analysis. Genes involved in plant growth promoting function such as synthesis of ACC deaminase, indole-3-acetic acid, trehalose, mineral scavenging siderophores, hydrogen cyanide, chitinases, acyl homoserine lactones, acetoin, 2,3-butanediol, and phytases were identified. In addition, niche-specific genes such as phosphate solubilising 3-phytase, adhesins, pathway-specific transcriptional regulators, a diguanylate cyclase involved in cellulose synthesis, a receptor for ferrienterochelin, a DEAD/DEAH-box helicase involved in stress tolerance, chemotaxis/motility determinants, an HtpX protease, and enzymes involved in the production of a chromanone derivative with potent antifungal activity were identified.

  7. Metabolic engineering of Klebsiella pneumoniae for the de novo production of 2-butanol as a potential biofuel.

    Science.gov (United States)

    Chen, Zhen; Wu, Yao; Huang, Jinhai; Liu, Dehua

    2015-12-01

    Butanol isomers are important bulk chemicals and promising fuel substitutes. The inevitable toxicity of n-butanol and isobutanol to microbial cells hinders their final titers. In this study, we attempt to engineer Klebsiella pneumoniae for the de novo production of 2-butanol, another butanol isomer which shows lower toxicity than n-butanol and isobutanol. 2-Butanol synthesis was realized by the extension of the native meso-2,3-butanediol synthesis pathway with the introduction of diol dehydratase and secondary alcohol dehydrogenase. By the screening of different secondary alcohol dehydrogenases and diol dehydratases, 320mg/L of 2-butanol was produced by the best engineered K. pneumoniae. The production was increased to 720mg/L by knocking out the ldhA gene and appropriate addition of coenzyme B12. Further improvement of 2-butanol to 1030mg/L was achieved by protein engineering of diol dehydratase. This work lays the basis for the metabolic engineering of microorganism for the production of 2-butanol as potential biofuel.

  8. Conducting polymer actuator based on chemically deposited polypyrrole and polyurethane-based solid polymer electrolyte working in air

    International Nuclear Information System (INIS)

    Conducting polymers (CPs), such as polypyrrole, polythiophene, and polyaniline, are unique in that they have switchable properties due to their two or more mechanically stable oxidation states. Thus, their films or coatings can be easily switched by the application of a small voltage and current to change their volume during electrochemical redox processes. In particular, polypyrrole (PPy) has been studied most extensively because of its high electrical conductivity and good environmental stability under ambient conditions. In this work, we have studied a new CP actuator, fully polymeric, assembled with two PPy film electrodes and a solid polymer electrolyte (SPE), polyurethane/Mg(ClO4)2. Polyurethanes (PUs) were synthesized from 4,4'-diphenylmethane diisocyanate (MDI), 1,4-butanediol (1,4-BD) and three types of polyol: poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), and PPG-block-PEG-block-PPG (PPG-co-PEG). The chemical polymerization of PPy by immersion in Py monomer aqueous solution and oxidant aqueous solution is an adequate method to prepare PU/PPy composite film as an actuator. To find the proper thickness of the PPy coating layer for actuation, we measured the displacements of the actuators according to the thickness of the PPy coating layer. The displacement of all actuators is discussed in connection with the properties of the SPE and PPy. All the results obtained in this work show the feasibility of electrochemomechanical devices based on PPy and SPE film being able to work in air

  9. Sol–gel processing of carbidic glasses

    Indian Academy of Sciences (India)

    L M Manocha; E Yasuda; Y Tanabe; S Manocha; D Vashistha

    2000-02-01

    Carbon incorporation into the silicate network results in the formation of rigid carbidic glasses with improved physical, mechanical and thermal properties. This generated great interest in the development of these heteroatom structured materials through different processing routes. In the present studies, sol–gel processing has been used to prepare silicon based glasses, especially oxycarbides through organic–inorganic hybrid gels by hydrolysis–condensation reactions in silicon alkoxides, 1,4-butanediol and furfuryl alcohol with an aim to introduce Si–C linkages in the precursors at sol level. The incorporation of these linkages has been studied using IR and NMR spectroscopy. These bonds, so introduced, are maintained throughout the processing, especially during pyrolysis to high temperatures. In FFA–TEOS system, copolymerization with optimized mol ratio of the two results in resinous mass. This precursor on pyrolysis to 1000°C results in Si–O–C type amorphous solid black mass. XRD studies on the materials heated to 1400°C exhibit presence of crystalline Si–C and cristobalites in amorphous Si–O–C mass. In organic–inorganic gel system, the pyrolysed mass exhibits phase stability up to much higher temperatures. The carbidic materials so produced have been found to exhibit good resistance against oxidation at 1000°C.

  10. Structural and magnetic properties of CoxFe3−xO4 versus Co/Fe molar ratio

    International Nuclear Information System (INIS)

    CoxFe3−xO4 (x=0.5–2.5) magnetic nanoparticles were synthesized via redox reaction between cobalt nitrate, iron nitrate and 1-4-butanediol using five Co/Fe molar ratios, followed by calcination at 1000 °C. Single phase nanoscaled cobalt ferrite was obtained at x=1.0 and at slight Co excess (x=1.5), while at high Co/Fe molar ratios (x=2.0 and x=2.5) the prevailing phase was CoO accompanied by CoFe2O4 traces. The highest values of coercive field and saturation magnetization were obtained for the sample at x=1.0, while the lowest values were obtained in the sample with the highest Co excess (x=2.5). The results indicated that the used synthesis route was suitable for the synthesis of cobalt ferrite with moderate saturation magnetization and high coercive field values. - Highlights: • Cobalt ferrite magnetic nanoparticles were synthesized by redox reaction. • The magnetic properties of CoxFe3−xO4 depend on the Co/Fe ratio. • Nanoparticles were spherical with sizes in the range of 30–73 nm. • At Co/Fe stoichiometric ratio and slight Co excess single phase CoFe2O4 results. • The critical role of Co concentration in the synthesized samples was revealed

  11. Affinity chromatography for the purification of therapeutic proteins from transgenic maize using immobilized histamine.

    Science.gov (United States)

    Platis, Dimitris; Labrou, Nikolaos E

    2008-03-01

    Plant molecular pharming is a technology that uses plants as bioreactors to produce recombinant molecules of medical and veterinary importance. In the present study, we evaluated the ability of histamine (HIM), tryptamine (TRM), phenylamine (PHEM) and tyramine (TYRM) coupled to Sepharose CL-4B via a 1,4-butanediol diglycidyl ether spacer to bind and purify human monoclonal anti-HIV antibody 2F5 (mAb 2F5) from spiked maize seed and tobacco leaf extracts. Detailed studies were carried out to determine the factors that affect the chromatographic behaviour of mAb 2F5 and also maize seed and tobacco leaf proteins. All affinity adsorbents showed a reduced capacity to bind and a reduced ability to purify proteins from tobacco extract compared to maize extract. Under optimal conditions, HIM exhibited high selectivity for mAb 2F5 and allowed a high degree of purification (>95% purity) and recovery (>90%) in a single step with salt elution (0.4 M KCl) from spiked maize seed extract. Analysis of the purified antibody fraction by ELISA and Western blot showed that the antibody was fully active and free of degraded variants or modified forms. The efficacy of the system was assessed further using a second therapeutic antibody (human monoclonal anti-HIV antibody mAb 2G12) and a therapeutic enzyme (alpha-chymotrypsin). HIM may find application in the purification of a wide range of biopharmaceuticals from transgenic plants.

  12. Metabolism and Virulence Strategies in Dickeya-Host Interactions.

    Science.gov (United States)

    Hugouvieux-Cotte-Pattat, N

    2016-01-01

    Dickeya, a genus of the Enterobacteriaceae family, all cause plant diseases. They are aggressive necrotrophs that have both a wide geographic distribution and a wide host range. As a plant pathogen, Dickeya has had to adapt to a vegetarian diet. Plants constitute a large storage of carbohydrates; they contain substantial amounts of soluble sugars and the plant cell wall is composed of long polysaccharides. Metabolic functions used by Dickeya in order to multiply during infection are essential aspects of pathogenesis. Dickeya is able to catabolize a large range of oligosaccharides and glycosides of plant origin. Glucose, fructose, and sucrose are all efficiently metabolized by the bacteria. To avoid the formation of acidic products, their final catabolism involves the butanediol pathway, a nonacidifying fermentative pathway. The assimilation of plant polysaccharides necessitates their prior cleavage into oligomers. Notably, the Dickeya virulence strategy is based on its capacity to dissociate the plant cell wall and, for this, the bacteria secrete an extensive set of polysaccharide degrading enzymes, composed mostly of pectinases. Since pectic polymers have a major role in plant tissue cohesion, pectinase action results in plant rot. The pectate lyases secreted by Dickeya play a double role as virulence factors and as nutrient providers. This dual function implies that the pel gene expression is regulated by both metabolic and virulence regulators. The control of sugar assimilation by specific or global regulators enables Dickeya to link its nutritional status to virulence, a coupling that optimizes the different phases of infection. PMID:27571693

  13. γ-羟基丁酸及其前体物质的滥用潜力和现状

    Institute of Scientific and Technical Information of China (English)

    宫琦; 梁建辉

    2012-01-01

    @@ 1956年,γ-氨基丁酸(gamma aminobutyric acid,GABA)作为主要的中枢神经系统(centrol nervous system,CNS)抑制性递质被发现.这引发了人们对可通透血脑屏障的GABA类似物的探寻,以期研制潜在的治疗性药物.随后,γ-羟基丁酸(γ-hydroxybutyrate,GHB)在脑中被发现并于1964年在实验室被合成[1],且作为中枢神经系统抑制剂在临床展开应用.近年来,GHB及其前体物质γ-丁内酯(γ-butyrolactone,GBL)和1,4-丁二醇(1,4-butanediol,1,4BD)成为了新兴的滥用药物,常被用作迷奸药,社会危害性极大.多国政府已将GHB归为管制药物,而与GHB有相似效应的两种前体物质却仍可合法使用.

  14. GHB, GBL and 1,4-BD addiction.

    Science.gov (United States)

    Brunt, Tibor M; van Amsterdam, Jan G C; van den Brink, Wim

    2014-01-01

    A growing body of evidence shows that gamma-hydroxybutyric acid (GHB) is an addictive substance. Its precursors gammabutyrolactone (GBL) and 1,4-butanediol (1,4-BD) show the same properties and may pose even more risks due to different pharmacokinetics. There are indications that problematic GHB use is increasing in the European Union. This review investigates the existing literature on the neurochemistry of GHB and its precursors, their acute toxicity, addiction potential and withdrawal, the proposed molecular mechanism underlying addiction and the treatment of withdrawal and addiction. Current evidence shows that GHB and its precursors are highly addictive, both in humans and animals, probably through a GABAB receptor related mechanism. Severity of withdrawal symptoms can be considered as a medical emergency. Recent studies suggest that benzodiazepines are not very effective, showing a high treatment resistance, whereas detoxification with pharmaceutical GHB proved to be successful. However, relapse in GHB use is frequent and more research is warranted on relapse prevention. This might aid medical practitioners in the field and improve general understanding of the severity of addiction to GHB, GBL and 1,4-BD.

  15. The Use of GHB to Facilitate Sexual Assault.

    Science.gov (United States)

    Marinetti, L; Montgomery, M A

    2010-01-01

    γ-Hydroxybutyric acid (GHB) and its metabolic precursors, γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), may be among the most favored drugs used to commit drug-facilitated sexual assault (DFSA). In fact, federal legislation was enacted in the form of the Hillory J. Farias and Samantha Reid Date-Rape Drug Prohibition Act of 2000 to control and penalize use and distribution of GHB, GBL, and 1,4-BD. Unfortunately, solid proof of their use in many cases is difficult to obtain because GHB, GBL, and 1,4-BD have strong sedative and memory-impairing effects and are rapidly eliminated after ingestion. To further complicate the matter, GHB is a metabolite of γ-aminobutyric acid (GABA), a naturally occurring neurotransmitter in humans. This review focuses on the chemistry and pharmacology of these drugs and their use in DFSA. An overview of analytical techniques used to identify their presence is provided, as well as guidance on the toxicological interpretation of findings of GHB in biological specimens.

  16. [Gamma-hydroxybutyric acid (GHB): more than a date rape drug, a potentially addictive drug].

    Science.gov (United States)

    Karila, Laurent; Novarin, Johanne; Megarbane, Bruno; Cottencin, Olivier; Dally, Sylvain; Lowenstein, William; Reynaud, Michel

    2009-10-01

    According to available information, GHB and its precursors--gamma-butyrolactone (GBL) and 1,4-butanediol (1,4BD)--are used especially in a nightlife scene characterized by the search for amplified sensations through the combination of electronic music, marathon dancing, and substance abuse. Evidence indicates that GHB/GHL is used particularly in some subpopulations and in places, such as in gay nightclubs. Commonly known as Gorliquid ecstasy, it was misused in the 1980s for its bodybuilding effects and in the 1990s as a recreational drug at music venues. In the same period, media coverage of the use of GHB in sexual assault (often referred to as date rape) brought the drug into the spotlight. GHB/GHL addiction is a recognized clinical entity evidenced by severe withdrawal symptoms when the drug is abruptly discontinued after regular or chronic use. There is evidence that negative health and social consequences may occur in recreational and chronic users. Nonfatal overdoses and deaths related to GHB have been reported. These undesirable effects and especially the deaths appear to have prompted campaigns to limit the use of GHB. Clinicians must also be aware of GBL, which is being sold and used as a substitute for GHB.

  17. 尿液、血液中γ-羟丁酸的气质联用法分析%Determination of Gamma-hydroxybutyric acid in urine and blood by GC-MS

    Institute of Scientific and Technical Information of China (English)

    刘晓茜; 沈敏; 刘伟; 沈保华; 向平

    2005-01-01

    目的为尿液、血液中γ-羟丁酸(gamma-bdroxybutyric acid,GHB),γ-羟丁酸内酯(gamma-butyro-lactone,GBL)和1,4-丁二醇(1,4-butanediol,1,4-BD)的鉴定提供方法和依据.方法100μl尿液或血液以GHB-d6为内标,经乙酸乙酯提取、BSTFA衍生化后,用GC/MS法分析.结果测尿液中内源性GHB的线性范围是20~800ng/ml,R2=0.999 5,最低检出限为10ng/ml(S/N≥3);测尿液、血液中外源性GHB的线性范围为5~60μg/ml,R2分别为0.999 9和0.992 8.相对回收率为99%~104%.以所建方法测定了健康志愿者尿液中内源性GHB含量,并考察了健康受试者外源性GHB的代谢情况.结论所建方法准确、便捷、省时、选择性好,适用于法医毒物学鉴定.

  18. Determination of GHB and its precursors (GBL and 1,4-BD) in dietary supplements through the synthesis of their isotopologues and analysis by GC-MS method.

    Science.gov (United States)

    Rosi, Luca; Frediani, Piero; Bartolucci, Gianluca

    2013-02-23

    Gamma-hydroxybutyric acid (GHB) and its "pro-drugs", gamma-butyrolactone (GBL) and 1,4 butanediol (1,4-BD), are drugs of abuse with depressant effects on the central nervous system. Many analytical methods have been proposed for the quantitative determination of these compounds mainly in biological matrices but only few have been addressed to dietary supplements and foods. Facile synthesis of the GBL and 1,4-BD isotopologues are available by "one pot" Ru-catalyzed homogeneous deuteration of dicarboxylic acids. In this work we propose a new method for determination of GHB, GBL and 1,4-BD in commercially available dietary supplements, based on isotope dilution mass spectrometry (ID-MS). The procedure involves a simple extraction of sample with acidic acetonitrile and direct analysis by GC-ID-MS method without any purification or derivatization. Indeed, the proposed method takes advantage of the complete conversion of GHB (free acid or its salts) to GBL, allowing the quantification of GHB and its pro-drugs. Five levels for each calibration curve have been prepared by diluting working solutions of the analytes to obtain concentrations ranging from 1 to 20mg/mL. The validation procedures have shown an accuracy between 88% and 99% and a precision between 7.3% and 2.9% of each analyte in the sample matrix. Positive ions chemical ionization (PICI) have been employed to preserve the information on molecular ions and to improve specificity and sensitivity of quantitative determination.

  19. Gamma-hydroxybutyrate (GHB): a scoping review of pharmacology, toxicology, motives for use, and user groups.

    Science.gov (United States)

    Brennan, Rebekah; Van Hout, Marie Claire

    2014-01-01

    Gamma hydroxybutyrate (GHB) is a central nervous system depressant with euphoric and relaxant effects. Documentation of GHB prevalence and the underreporting of abuse remains problematic, given the availability of GHB and its precursors γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) and the ease of synthesis from kits available on the Internet. The continued abuse of and dependence on GHB, and associated fatalities, present an on-going public health problem. As the drug GHB remains an underresearched topic, a scoping review was chosen as a technique to map the available literature into a descriptive summarized account. PRISMA was used to assist in data retrieval, with subsequent data charting into three key themes (pharmacology and toxicology, outcomes, and user groups). Administered orally, GHB is dose-dependent and popular for certain uses (therapeutic, body enhancement, sexual assault) and amongst user sub groups (recreational party drug users, homosexual men). Despite the low prevalence of use in comparison to other club drugs, rising abuse of the drug is associated with dependence, withdrawal, acute toxicity, and fatal overdose. Clinical diagnosis and treatment is complicated by the co-ingestion of alcohol and other drugs. Limitations of the scoping review and potential for further research and harm reduction initiatives are discussed.

  20. Syntheses of silsesquioxane (POSS)-based inorganic/organic hybrid and the application in reinforcement for an epoxy resin.

    Science.gov (United States)

    Ni, Caihua; Ni, Guifeng; Zhang, Liping; Mi, Jiaquan; Yao, Bolong; Zhu, Changping

    2011-10-01

    A new inorganic/organic hybrid material containing silsesquioxane was prepared by the reaction of caged octa (aminopropyl silsesquioxane) (POSS-NH(2)) with n-butyl glycidyl ether (nBGE) and 1,4-butanediol diglycidyl ether (BDGE). The copolymers of POSS, nBGE, and BDGE could be obtained with varied feed ratio of POSS-NH(2), nBGE, and BDGE in the preparation. The hybrid material was added into an epoxy resin (E51) for enhancing the toughening and thermal properties of the epoxy resin. The results showed that the toughening and the thermal properties of the cured epoxy resin were greatly improved by the addition of the hybrid. The enhancement was ascribed to nano-scale effect of the POSS structure and the formation of anchor structure in the cured network. The investigation of kinetics for the curing process of the hybrid-modified epoxy resin revealed that two kinds of curing reactions occurred in different temperature ranges. They were attributed to the reactions between amino groups of the curing agent with epoxy groups of E51 and with residue epoxy groups in the hybrid. The reacting activation energies were calculated based on Kissinger's and Flynn-Wall-Ozawa's methods, respectively.

  1. Combinatorial metabolic pathway assembly in the yeast genome with RNA-guided Cas9.

    Science.gov (United States)

    EauClaire, Steve F; Zhang, Jianzhong; Rivera, Corban Gregory; Huang, Lixuan L

    2016-07-01

    The yeast Saccharomyces cerevisiae is an important industrial platform for the production of grain and cellulosic ethanol, isobutanol, butanediol, isoprenoids, and other chemicals. The construction of a successful production strain usually involves multiple gene knockouts and chromosomal integration of expression cassettes to redirect the metabolic fluxes for the conversion of sugars and other feed stocks into the desired product. RNA-guided Cas9 based genome editing has been demonstrated in many prokaryotic and eukaryotic hosts including S. cerevisiae, in which it has been additionally exploited as a tool for metabolic engineering. To extend the utilization of RNA-guided Cas9 as a metabolic pathway building tool, we demonstrated the direct assembly and chromosomal integration of up to 17 overlapping DNA fragments encoding the beta-carotene biosynthetic pathway. Furthermore, we generated a combinatorial strain library for the beta-carotene biosynthetic pathway, directly integrated into the yeast genome to create a diverse library of strains. This enabled the screening of combinatorial libraries in stable chromosomally integrated strains for rapid improvements of product titers. This combinatorial approach for pathway assembly will significantly accelerate the current speed of metabolic engineering for S. cerevisiae as an industrial platform, and increase the number of strains that can be simultaneously evaluated for enzyme screening, expression optimization and protein engineering to achieve the titer, rate and yield necessary for the commercialization of new industrial fermentation products. PMID:27138038

  2. TECHNOLOGIES OF SYNTHESIS OF ORGANIC SUBSTANCES BY MICROORGANISMS USING WASTE BIODIESEL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Pirog T. P.

    2015-08-01

    Full Text Available We describe here literature and our experimental data concerning microbial synthesis using waste biodiesel production, mono- and dihydric alcohols (1,3-propanediol, 2,3-butanediol, butanol, ethanol, polyols (mannitol, erythritol, arabitol, organic acids (citric, succinic, lactic, glyceric, polymers and compounds with a complex structure (polysaccharides, polyhydroxyalkanoates, surfactants, cephalosporin, cyanocobalamin. In some mentioned cases recombinant producer strains were used. It was shown that due to the presence of potential inhibitors in the composition of technical (crude glycerol (methanol, sodium and potassium salts, the efficiency of synthesis of most microbial products on such a substrate is lower than on the purified glycerol. However, the need of utilization of this toxic waste (storage and processing of crude glycerol is a serious environmental problem due to the high alkalinity and the content of methanol in it, compensates the lower rates of synthesis of the final product. Furthermore, currently considering the volumes of crude glycerol formed during the production of biodiesel, microbial technologies are preferred for its utilization, allowing realizing biosynthesis of practically valuable metabolites in the environment with the highest possible concentration of this waste. Using of crude glycerol as a substrate will reduce the cost of products of microbial synthesis and increase the profitability of biodiesel production.

  3. An Injectable Hydrogel as Bone Graft Material with Added Antimicrobial Properties

    Science.gov (United States)

    Tommasi, Giacomo; Perni, Stefano

    2016-01-01

    Currently, the technique which provides the best chances for a successful bone graft, is the use of bone tissue from the same patient receiving it (autograft); the main limitations are the limited availability and the risks involved in removing living bone tissue, for example, explant site pain and morbidity. Allografts and xenografts may overcome these limitations; however, they increase the risk of rejection. For all these reasons the development of an artificial bone graft material is particularly important and hydrogels are a promising alternative for bone regeneration. Gels were prepared using 1,4-butanediol diacrylate as crosslinker and alpha tricalciumphosphate; ZnCl2 and SrCl2 were added to the aqueous phase. MTT results demonstrated that the addition of strontium had a beneficial effect on the osteoblast cells density on hydrogels, and zinc instead did not increase osteoblast proliferation. The amount of calcium produced by the osteoblast cells quantified through the Alizarin Red protocol revealed that both strontium and zinc positively influenced the formation of calcium; furthermore, their effect was synergistic. Rheology properties were used to mechanically characterize the hydrogels and especially the influence of crosslinker's concentration on them, showing the hydrogels presented had extremely good mechanical properties. Furthermore, the antimicrobial activity of strontium and zinc in the hydrogels against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis was determined. PMID:27174392

  4. Revealing the morphological architecture of a shape memory polyurethane by simulation.

    Science.gov (United States)

    Hu, Jinlian; Zhang, Cuili; Ji, Fenglong; Li, Xun; Han, Jianping; Wu, You

    2016-01-01

    The lack of specific knowledge of the network structure in shape memory polymers (SMPs) has prevented us from gaining an in-depth understanding of their mechanisms and limited the potential for materials innovation. This paper firstly reveals the unit-cell nanoscale morphological architecture of SMPs by simulation. The phase separated architecture of a segmented shape memory polyurethane (SMPU) with a 30 wt% hard segment content (HSC, 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO)) showing good shape memory properties was investigated by dissipative particle dynamics (DPD) simulations. A linked-spherical netpoint-frame phase of MDI, a matrix-switch phase of polycaprolactone (PCL) and a connected-spider-like interphase for BDO were obtained for this SMPU. The BDO interphase can reinforce the MDI network. Based on these simulation results, a three-dimensional (3D) overall morphological architectural model of the SMPU can be established. This theoretical study has verified, enriched and integrated two existing schematic models: one being the morphological model deduced from experiments and the other the frame model for SMPs reported before. It can serve as a theoretical guide for smart polymeric materials design. This method for the simulation of polymer structure at the nanoscale can be extended to many areas such as photonic crystals where nanoscale self-assembly plays a vital role. PMID:27373495

  5. Dynamic mechanical and thermal properties of seven polyurethane adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.M.

    1981-03-01

    Seven polyurethane adhesives have been developed at Lawrence Livermore National Laboratory (LLNL). These adhesives, designated Halthanes were synthesized because of OSHA restrictions on the use of the curing agent methylene bis(2-chloroaniline). Four of the Halthanes were made from LLNL-developed 4,4'-methylene bis(phenylisocyanate) terminated prepolymers cured with a blend of polyols; three were made from an LLNL-developed prepolymer terminated with Hylene W and cured with aromatic diamines. In this paper the dynamic mechanical and thermal behavior of these seven segmented polyurethanes are discussed. The chemical structure of the hard and soft segments, the concentrations of each block, and the presence of tetrafunctional crosslinker determined the dynamic mechanical and thermal properties of the three types of polyurethane adhesives, 73-, 87-, and 88-series Halthanes studied. Aromatic-aliphatic MDI- butanediol urethane hard segments produce lower modulus (10/sup 6/ Pa) materials in the rubbery region than cyclic unsaturated-aromatic urea hard segments. Incorporation of chemical crosslinks in the hard segments extended the rubbery plateau beyond the hard segment transitions up to temperatures where the polymer begins to degrade. Concentration of hard and soft segments can also be used to control the modulus between the glass transition temperatures of the two blocks.

  6. Modelling the surface free energy parameters of polyurethane coats-part 1. Solvent-based coats obtained from linear polyurethane elastomers.

    Science.gov (United States)

    Król, Piotr; Lechowicz, Jaromir B; Król, Bożena

    2013-04-01

    Polyurethane elastomers coating were synthesised by using typical diisocyanates, polyether and polyester polyols and HO-tertiary amines or diols as a chain extenders. Mole fractions of structural fragments (κ exp) responsible for the polar interactions within polyurethane chains were calculated by (1)H NMR method. Obtained results were confronted with the analogous parameter values (κ theor) calculated on the basis of process stoichiometry, considering the stage of the production of isocyanate prepolymers and reaction of their extension for polyurethanes. Trials of linear correlation between the κ exp parameters and surface free energy (SFE) values of investigated coatings were presented. SFE values were determined by Owens-Wendt method, using contact angles measured with the goniometric method. Based on achieved results, another empirical models, allowing for prediction the influence of the kind of polyurethane raw materials on SFE values of received coatings were determined. It was found that it is possible to regulate the SFE in the range millijoules per cubic metre by the selection of appropriate substrates. It has been found that use of 2,2,3,3-tetrafluoro-1,4-butanediol as a fluorinated extender of prepolymer chains is essential to obtain coatings with increased hydrophobicity, applied among others as biomaterials-next to diphenylmethane diisocyanate and polyoxyethylene glycol. PMID:23525512

  7. Synthesis, platelet adhesion and cytotoxicity studies of new glycerophosphoryl-containing polyurethanes.

    Science.gov (United States)

    D'Arrigo, P; Giordano, C; Macchi, P; Malpezzi, L; Pedrocchi-Fantoni, G; Servi, S

    2007-02-01

    In this work we synthesized new MDI -based poly(ether)urethanes (PEUs) with phospholipid-like residue as chain extender. Polymers were prepared by a conventional two-step solution polymerization procedure using 4,4' diphenylmethanediisocyanate (MDI) and poly(1,4- butanediol) with 1000 as molecular weight to form prepolymers which were successively polymerized with 1 glycerophosphorylcholine (1-GPC), 2-glycerophosphorylcholine (2-GPC) or glycerophosphorylserine (GPS) as chain extenders. Two reference polymers bearing 1,4-butandiol (BD) have been also synthesized. The polymers obtained were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and modulated scanning calorimetry (MDSC). The biocompatibility of synthesized segmented polyurethanes was then investigated by platelet-rich plasma contact studies and related scanning electron microscopy (SEM) photographs for blood compatibility and cytotoxicity assay (MTT test) on material elution to assess the effect of any toxic leachables on cellular viability. Three polymers among all have given very satisfactory results suggesting to investigate more deeply their possible use in biomedical devices. PMID:17377908

  8. [Gamma-hydroxybutyric acid (GHB): more than a date rape drug, a potentially addictive drug].

    Science.gov (United States)

    Karila, Laurent; Novarin, Johanne; Megarbane, Bruno; Cottencin, Olivier; Dally, Sylvain; Lowenstein, William; Reynaud, Michel

    2009-10-01

    According to available information, GHB and its precursors--gamma-butyrolactone (GBL) and 1,4-butanediol (1,4BD)--are used especially in a nightlife scene characterized by the search for amplified sensations through the combination of electronic music, marathon dancing, and substance abuse. Evidence indicates that GHB/GHL is used particularly in some subpopulations and in places, such as in gay nightclubs. Commonly known as Gorliquid ecstasy, it was misused in the 1980s for its bodybuilding effects and in the 1990s as a recreational drug at music venues. In the same period, media coverage of the use of GHB in sexual assault (often referred to as date rape) brought the drug into the spotlight. GHB/GHL addiction is a recognized clinical entity evidenced by severe withdrawal symptoms when the drug is abruptly discontinued after regular or chronic use. There is evidence that negative health and social consequences may occur in recreational and chronic users. Nonfatal overdoses and deaths related to GHB have been reported. These undesirable effects and especially the deaths appear to have prompted campaigns to limit the use of GHB. Clinicians must also be aware of GBL, which is being sold and used as a substitute for GHB. PMID:19762202

  9. Systems strategies for developing industrial microbial strains.

    Science.gov (United States)

    Lee, Sang Yup; Kim, Hyun Uk

    2015-10-01

    Industrial strain development requires system-wide engineering and optimization of cellular metabolism while considering industrially relevant fermentation and recovery processes. It can be conceptualized as several strategies, which may be implemented in an iterative fashion and in different orders. The key challenges have been the time-, cost- and labor-intensive processes of strain development owing to the difficulties in understanding complex interactions among the metabolic, gene regulatory and signaling networks at the cell level, which are collectively represented as overall system performance under industrial fermentation conditions. These challenges can be overcome by taking systems approaches through the use of state-of-the-art tools of systems biology, synthetic biology and evolutionary engineering in the context of industrial bioprocess. Major systems metabolic engineering achievements in recent years include microbial production of amino acids (L-valine, L-threonine, L-lysine and L-arginine), bulk chemicals (1,4-butanediol, 1,4-diaminobutane, 1,5-diaminopentane, 1,3-propanediol, butanol, isobutanol and succinic acid) and drugs (artemisinin). PMID:26448090

  10. Identification and quantification of the main organic components of vinegars by high resolution 1H NMR spectroscopy.

    Science.gov (United States)

    Caligiani, A; Acquotti, D; Palla, G; Bocchi, V

    2007-02-28

    A detailed analysis of the proton high-field NMR spectra of vinegars (in particular of Italian balsamic vinegars) is reported. A large number of organic substances belonging to different classes, such as carbohydrates, alcohols, organic acids, volatile compounds and amino acids, were assigned. The possibility of quantification of the substances identified in the whole vinegar sample, without extraction or pre-concentration steps, was also tested. The data validity was demonstrated in terms of precision, accuracy, repeatability and inter-day reproducibility. The effects of the most critical experimental parameters (sample concentration, water suppression and relaxation time) on the analysis response were also discussed. (1)H NMR results were compared with those obtained by traditional techniques (GC-MS, titrations), and good correlations were obtained. The results showed that (1)H NMR with water suppression allows a rapid, simultaneous determination of carbohydrates (glucose and fructose), organic acids (acetic, formic, lactic, malic, citric, succinic and tartaric acids), alcohols and polyols (ethanol, acetoin, 2,3-butanediol, hydroxymethylfurfural), and volatile substances (ethyl acetate) in vinegar samples. On the contrary, the amino acid determination without sample pre-concentration was critical. The (1)H NMR method proposed was applied to different samples of vinegars, allowing, in particular, the discrimination of vinegars and balsamic vinegars. PMID:17386654

  11. Life-cycle fossil energy consumption and greenhouse gas emissions of bioderived chemicals and their conventional counterparts.

    Science.gov (United States)

    Adom, Felix; Dunn, Jennifer B; Han, Jeongwoo; Sather, Norm

    2014-12-16

    Biomass-derived chemical products may offer reduced environmental impacts compared to their fossil-derived counterparts and could improve profit margins at biorefineries when coproduced with higher-volume, lower-profit margin biofuels. It is important to assess on a life-cycle basis the energy and environmental impacts of these bioproducts as compared to conventional, fossil-derived products. We undertook a life-cycle analysis of eight bioproducts produced from either algal-derived glycerol or corn stover-derived sugars. Selected on the basis of technology readiness and market potential, the bioproducts are propylene glycol, 1,3-propanediol, 3-hydroxypropionic acid, acrylic acid, polyethylene, succinic acid, isobutanol, and 1,4-butanediol. We developed process simulations to obtain energy and material flows in the production of each bioproduct and examined sensitivity of these flows to process design assumptions. Conversion process data for fossil-derived products were based on the literature. Conversion process data were combined with upstream parameters in the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model to generate life-cycle greenhouse gas (GHG) emissions and fossil energy consumption (FEC) for each bioproduct and its corresponding petroleum-derived product. The bioproducts uniformly offer GHG emissions reductions compared to their fossil counterparts ranging from 39 to 86% on a cradle-to-grave basis. Similarly, FEC was lower for bioproducts than for conventional products. PMID:25380298

  12. Cross-linked Polyethylenimine as Potential DNA Vector for Gene Delivery with High Efficiency and Low Cytotoxicity

    Institute of Scientific and Technical Information of China (English)

    Wei DONG; Guang-Hui JIN; Shu-Feng LI; Qi-Ming SUN; Ding-Yuan MA; Zi-Chun HUA

    2006-01-01

    Polyethylenimine (PEI) has been known as an efficient gene carrier with the highest cationic charge potential. High transfection efficiency of PEI, along with its cytotoxicity, strongly depends on its molecular weight. To enhance its gene delivery efficiency and minimize cytotoxicity, we have synthesized small cross-linked PEI with biodegradable linkages and evaluated their transfection efficiencies in vitro. In this study, branched PEI with a molecular weight of 800 Da was cross-linked by small diacrylate [ 1,4-butanediol diacrylate or ethyleneglycol dimethacrylate (EGDMA)] for 2-6 h. The efficiencies of the cross-linked PEI in in vitro transfection of plasmid DNA containing enhanced green fluorescent protein (EGFP) reporter gene were assessed in melanoma B 16F10 cell line and other cell lines. Flow cytometry was used to quantify the cellular entry efficiency of plasmid and the transgene expression level. The cytotoxicities of the cross-linked PEI in these cells were evaluated by MTT assay. EGDMA-PEI 800-4h, a typical cross-linked PEI reported here, mediated a more efficient expression of reporter gene than the commercially available 25-kDa branched PEI control, and resulted in a 9-fold increase in gene delivery in B16F10 cells and a 16-fold increase in 293T cells, while no cytotoxicity was found at the optimized condition for gene delivery. Furthermore, the transfection activity of polyplexes was preserved in the presence of serum proteins.

  13. Inhibitory Effects of Chemical Compounds Isolated from the Rhizome of Smilax glabra on Nitric Oxide and Tumor Necrosis Factor-α Production in Lipopolysaccharide-Induced RAW264.7 Cell

    Directory of Open Access Journals (Sweden)

    Chuan-li Lu

    2015-01-01

    Full Text Available The rhizome of Smilax glabra has been used for a long time as both food and folk medicine in many countries. The present study focused on the active constituents from the rhizome of S. glabra, which possess potential anti-inflammatory activities. As a result, nine known compounds were isolated from the rhizome of S. glabra with the bioassay-guiding, and were identified as syringaresinol (1, lasiodiplodin (2, de-O-methyllasiodiplodin (3, syringic acid (4, 1,4-bis(4-hydroxy-3,5-dimethoxyphenyl-2,3-bis(hydroxymethyl-1,4-butanediol (5, lyoniresinol (6, trans-resveratrol (7, trans-caffeic acid methyl ester (8, and dihydrokaempferol (9. Among these compounds, 2 and 3 were isolated for the first time from S. glabra. In addition, the potential anti-inflammatory activities of the isolated compounds were evaluated in vitro in lipopolysaccharide- (LPS- induced RAW264.7 cells. Results indicated that 4 and 7 showed significant inhibitory effects on NO production of RAW264.7 cells, and 1, 2, 3, and 5 showed moderate suppression effects on induced NO production. 1, 7, and 5 exhibited high inhibitory effects on TNF-α production, with the IC50 values less than 2.3, 4.4, and 16.6 μM, respectively. These findings strongly suggest that compounds 1, 2, 3, 4, 5, 7, and 9 were the potential anti-inflammatory active compositions of S. glabra.

  14. A new crystal form of human tear lipocalin reveals high flexibility in the loop region and induced fit in the ligand cavity

    Science.gov (United States)

    Breustedt, Daniel A.; Chatwell, Lorenz; Skerra, Arne

    2009-01-01

    Tear lipocalin (TLC) with the bound artificial ligand 1,4-butanediol has been crystallized in space group P21 with four protein molecules in the asymmetric unit and its X-ray structure has been solved at 2.6 Å resolution. TLC is a member of the lipocalin family that binds ligands with diverse chemical structures, such as fatty acids, phospholipids and cholesterol as well as microbial siderophores and the antibiotic rifampin. Previous X-ray structural analysis of apo TLC crystallized in space group C2 revealed a rather large bifurcated ligand pocket and a partially disordered loop region at the entrace to the cavity. Analysis of the P21 crystal form uncovered major conformational changes (i) in β-strands B, C and D, (ii) in loops 1, 2 and 4 at the open end of the β-­barrel and (iii) in the extended C-terminal segment, which is attached to the β-­barrel via a disulfide bridge. The structural comparison indicates high conformational plasticity of the loop region as well as of deeper parts of the ligand pocket, thus allowing adaptation to ligands that differ vastly in size and shape. This illustrates a mechanism for promiscuity in ligand recognition which may also be relevant for some other physiologically important members of the lipocalin protein family. PMID:19770509

  15. Degradation of di(2-ethyl hexyl) phthalate by Fusarium culmorum: Kinetics, enzymatic activities and biodegradation pathway based on quantum chemical modelingpathway based on quantum chemical modeling.

    Science.gov (United States)

    Ahuactzin-Pérez, Miriam; Tlecuitl-Beristain, Saúl; García-Dávila, Jorge; González-Pérez, Manuel; Gutiérrez-Ruíz, María Concepción; Sánchez, Carmen

    2016-10-01

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. The specific growth rate (μ), maximum biomass (Xmax), biodegradation constant of DEHP (k), half-life (t1/2) of DEHP biodegradation and removal efficiency of DEHP, esterase and laccase specific activities, and enzymatic yield parameters were evaluated for Fusarium culmorum grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L). The greatest μ and the largest Xmax occurred in media supplemented with 1000mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000mg/L) within 60h of growth. The k and t1/2 were 0.024h(-1) and 28h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500mg/L, respectively. Much higher specific esterase activity than specific laccase activity was observed in all media tested. The compounds of biodegradation of DEHP were identified by GC-MS. A DEHP biodegradation pathway by F. culmorum was proposed on the basis of the intermolecular flow of electrons of the identified intermediate compounds using quantum chemical modeling. DEHP was fully metabolized by F. culmorum with butanediol as the final product. This fungus offers great potential in bioremediation of environments polluted with DEHP.

  16. Synthesis and characterization of biodegradable aliphatic copolyesters with hydrophilic soft segments

    Directory of Open Access Journals (Sweden)

    JASNA DJONLAGIC

    2004-12-01

    Full Text Available In this study, the synthesis, structure and physical properties of two series of segmented poly(ester-ethers based on poly(butylene succinate and two different types of polyethers were investigated. The poly(ester-ethers were synthesized by transesterification reaction of dimethyl succinate, 1,4-butanediol and poly(ethylene oxide (PEO, Mn = 1000 g/mol in the first series, and poly(tetramethylene oxide (PTMO, Mn = 1000 g/mol in the second. The mass fraction of soft segments was varied between 10 and 50 mass. %. The effect of the introduction of two different polyether soft segments on the structure, thermal and rheological properties were investigated. The composition of the poly(ester-ethers, determined from their 1H-NMR spectra, showed that incorporation of soft polyether segments was successfully performed by the transesterification reaction in bulk. The molecular weight was estimated from solution viscosity measurements and complex dynamic viscosities. The thermal properties investigated by DSC indicated that the presence of soft segments lowers the melting and crystallization temperature of the hard phase, as well as the degree of crystallinity. Dynamical mechanical analysis was used to investigate the influence of composition on the rheological behavior of the segmented poly(ester-ethers. The results obtained from an enzymatic degradation test performed on some of the synthesized polymers showed that the biodegradability is enhanced with increasing hydrophilicity.

  17. Permeability of different types of medical protective gloves to acrylic monomers.

    Science.gov (United States)

    Lönnroth, Emma-Christin; Wellendorf, Hanne; Ruyter, Eystein

    2003-10-01

    Dental personnel and orthopedic surgeons are at risk when manually handling products containing methyl methacrylate (MMA). Dental products may also contain cross-linking agents such as ethylene glycol dimethacrylate (EGDMA) or 1,4-butanediol dimethacrylate (1,4-BDMA). Skin contact with monomers can cause hand eczema, and the protection given by gloves manufactured from different types of material is not well known. The aim of this study was to determine the breakthrough time (BTT, min) as a measure of protection (according to the EU standard EN-374-3) for a mixture consisting of MMA, EGDMA and 1,4-BDMA. Fifteen different gloves representing natural rubber latex material, synthetic rubber material (e.g. nitrile rubbers), and synthetic polymer material were tested. The smallest monomer MMA permeated within 3 min through all glove materials. A polyethylene examination glove provided the longest protection period to EGDMA and 1, 4-BDMA (> 120 min and 25.0 min), followed by the surgical glove Tactylon (6.0 min and 8.7 min) and the nitrile glove Nitra Touch (5.0 min and 8.7 min). This study showed that the breakthrough time (based on permeation rate) cannot be regarded as a 'safe limit'. When the permeation rate is low, monomers may have permeated before BTT can be determined. Using double gloves with a synthetic rubber inner glove and a natural rubber outer glove provided longer protection when the inner glove was rinsed in water before placing the outer glove on top.

  18. SHAPE MEMORY EFFECT OF PU IONOMERS WITH IONIC GROUPS ON HARD-SEGMENTS

    Institute of Scientific and Technical Information of China (English)

    Yong Zhu; Jin-lian Hu; Kwok-wing Yeung; Hao-jun Fan; Ye-qiu Liu

    2006-01-01

    SMPU (shape memory polyurethane) non-ionomers and ionomers, synthesized with poly(ε-caprolactone) (PCL),4, 4'-diphenylmethane diisocyanate (MDI), 1,4-butanediol (BDO), dimethylolpropionic acid (DMPA) were measured with cyclic tensile test and strain recovery test. The relations between the structure and shape memory effect of these two series were studied with respect to the ionic group content and the effect of neutralization. The resulting data indicate that, with the introduction of asymmetrical extender, the stress at 100% elongation is decreased for PU non-ionomer and ionomer series,especially lowered sharply for non-ionomer series; the fixation ratio of ionomer series is not affected obviously by the ionic group content; the total recovery ratio of ionomer series is decreased greatly. After sufficient relaxation time for samples stretched beforehand, the switching temperature is raised slightly, whereas the recovery ratio measured with strain recovery test method is lowered with increased DMPA content. The characterization with FT-IR, DSC, DMA elucidated that, the ordered hard domain of the two series is disrupted with the introduction of DMPA which causes more hard segments to dissolve in soft phase; ionic groups on hard segment enhance the cohesion between hard segments especially at high ionic group content and significantly facilitate the phase separation compared with the corresponding non-ionomer at moderate ionic group content.

  19. Short communication: Use of a mixture of sodium nitrite, sodium benzoate, and potassium sorbate in aerobically challenged silages.

    Science.gov (United States)

    Knicky, Martin; Spörndly, Rolf

    2015-08-01

    Aerobic instability is still a common problem with many types of silages, particularly well-fermented silages. This study evaluated the effect of adding an additive mixture based on sodium nitrite, sodium benzoate, and potassium sorbate to a variety of crop materials on fermentation quality and aerobic stability of silages. Ensiling conditions were challenged by using a low packing density (104±4.3kg of dry matter/m(3)) of forage and allowing air ingression into silos (at 14 and 7 d before the end of the storage, for 8 h per event). Additive-treated silages were found to have significantly lower pH and reduced formation of ammonia-N, 2.3-butanediol, and ethanol compared with untreated control silages. Yeast growth was significantly reduced by additive treatment in comparison with untreated control silage. Consequently, additive-treated silages were considerably more aerobically stable (6.7 d) than untreated control silages (0.5 d). Overall, adding 5mL/kg of fresh crop of the additive based on sodium nitrite, sodium benzoate, and potassium sorbate reduced undesirable microorganisms in silages and thereby provided suitable ensiling conditions and prolonged aerobic stability, even under air-challenged laboratory ensiling conditions. PMID:26026758

  20. Evaluation of glycidyl methacrylate-based monolith functionalized with weak anion exchange moiety inside 0.5 mm i.d. column for liquid chromatographic separation of DNA

    Directory of Open Access Journals (Sweden)

    Aprilia Nur Tasfiyati

    2016-03-01

    Full Text Available In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100 × 0.5 mm i.d. by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogenic solvents, with the presence of initiator α,α′-azobisisobutyronitrile (AIBN. The monolith matrix was modified with diethylamine to create weak anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by SEM. The properties of the monolithic column, such as permeability, mechanical stability, binding capacity and pore size distribution, were characterized in detail. From the results of the characterization, monoliths poly-(GMA-co-EDMA with total monomer percentage (%T 40 and crosslinker percentage (%C 25 was found to be the ideal composition of monomer and crosslinker. It has good mechanical stability and high permeability, adequate molecular recognition sites (represented with binding capacity value of 36 mg ml−1, and has relatively equal proportion of flow-through pore and mesopores (37.2% and 41.1% respectively. Poly-(GMA-co-EDMA with %T 40 and %C 25 can successfully separate oligo(dT12–18 and 50 bp DNA ladder with good resolution.

  1. Lack of RsmA-mediated control results in constant hypervirulence, cell elongation, and hyperflagellation in Pectobacterium wasabiae.

    Science.gov (United States)

    Kõiv, Viia; Andresen, Liis; Broberg, Martin; Frolova, Jekaterina; Somervuo, Panu; Auvinen, Petri; Pirhonen, Minna; Tenson, Tanel; Mäe, Andres

    2013-01-01

    The posttranscriptional regulator RsmA controls the production of plant cell wall degrading enzymes (PCWDE) and cell motility in the Pectobacterium genus of plant pathogens. In this study the physiological role of gene regulation by RsmA is under investigation. Disruption of rsmA gene of the Pectobacterium wasabiae strain, SCC3193 resulted in 3-fold decrease in growth rate and increased virulence. The comparison of mRNA levels of the rsmA(-) mutant and wild-type using a genome-wide microarray showed, that genes responsible for successful infection, i.e. virulence factors, motility, butanediol fermentation, various secretion systems etc. were up-regulated in the rsmA(-) strain. The rsmA(-) strain exhibited a higher propensity to swarm and produce PCWDE compared to the wild-type strain. Virulence experiments in potato tubers demonstrated that in spite of its more efficient tissue maceration, the rsmA(-) strain's ability to survive within the host is reduced and the infection site is taken over by resident bacteria. Taken together, in the absence of RsmA, cells revert to a constitutively infective phenotype characterized by expression of virulence factors and swarming. We hypothesize that lack of control over these costly energetic processes results in decreased growth rate and fitness. In addition, our findings suggest a relationship between swarming and virulence in plant pathogens. PMID:23372695

  2. Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

    Science.gov (United States)

    Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

    2015-10-01

    A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC. PMID:26187821

  3. FTIR and molecular mechanics studies of H-bonds in aliphatic polyurethane and polyamide-66 model molecules

    Science.gov (United States)

    Wang, Guoqing; Zhang, Chunxia; Guo, Xiaohe; Ren, Zhiyong

    2008-02-01

    Model aliphatic polyurethane (APU) hard segment based on 1,6-hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO) were prepared. FTIR and molecular mechanics (MM) simulation were used to conduct the systematic studies on APU and polyamide-66 (PA-66) whose sole difference lies in the alkoxyl oxygen. It was found that the introduction of the alkoxyl not only increases the conformations in APU, makes it a possible H-bond acceptor, but also weakens the H-bond between NH and O dbnd C in APU. There are two conformers stably existed in APU with lowest energy, leading to eight H-bond complexes based on NH as donor and (1) O dbnd C as acceptor, and another two complexes based on (2) alkoxyl O and (3) urethane N as acceptors, whereas there is only one stable conformer in PA-66, leading to one H-bond complex. One predominant H-bond complex has been found in APU with probability of about 95%. The simulated results are consistent with the νNH and νC dbnd O band shifting in FTIR.

  4. Synthesis of waterborne polyurethane containing alkoxysilane side groups and the properties of the hybrid coating films

    Science.gov (United States)

    Li, Qi; Guo, Longhai; Qiu, Teng; Xiao, Weidong; Du, Dianxing; Li, Xiaoyu

    2016-07-01

    A series of waterborne polyurethane (WPU) containing alkoxysilane side groups were synthesized by using the dihydroxy functionalized alkoxysilane. The diol with trimethoxysilane groups at the side chains was synthesized via Michael addition between 3-(methacryloxypropyl)trimethoxysilane (MAPTS) and diethanolamine (DEA). The silane diol was applied as the chain extender for the NCO-endcapped prepolymer of isophorone diisocyanate, polycarbonate diol, 2,2-bis(hydroxymethyl) butyric acid and 1,4-butanediol. The products with the silane content varied from 1.2 to 16.5 wt% were dispersed in water after neutralization. The effect of the silane diol on the particle size and morphology of the WPU dispersion was studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. X-ray photoelectron spectroscopy (XPS) characterization was carried out on the coating film of the WPU, revealing that the long flexible side chain is favorable for the silane components to emigrate toward the film surface and crosslink during the film formation process. As a result, both the surface contact angle to water and water adsorption of the WPU coating films increased with the silane content. Furthermore, the mechanical properties including the modulus and tensile strength of the films were also improved by the incorporation of silane diol.

  5. MIXED SUBSTRATES IN ENVIRONMENT AND BIOTECHNOLOGICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2013-12-01

    Full Text Available The modern literature and own experimental data on the use of substrates’ mixtures for intensification of microbial synthesis technologies of practically valuable fermentation products (ethanol, lactic acid, butanediol, primary (amino acids, n-hydroxybenzoate, triglycerides and secondary (lovastatin, surfactants metabolites as well as for intensification of biodegradation of aromatic xenobiotics (benzene, cresols, phenols, toluene and pesticides (dimethoate are presented. Special attention is paid on the molecular mechanisms that were established in recent years and underlying the phenomenon catabolic repression in Gram-positive (Bacillus subtilis and Gram-negative (Pseudomonas, Escherichia coli bacteria and yeast Saccharomyces cerevisiae, and on the use of these data to develop technologies for utilization of plant biomass to produce industrially important metabolites. The survival strategies of heterotrophic microorganisms in natural oligotrophic environments are considered, including the simultaneous use of multiple substrates, allowing improved kinetic characteristics that give them a competitive advantage, also provided significant metabolic/physiological flexibility. The own experimental data on the use of mixtures of growth substrates for the intensification of surfactants’ synthesis of Rhodococcus erythropolis IMV Ac-5017 and Acinetobacter calcoaceticus IMV B-7241 are summarized. The dependence of the synthesis of surfactants in a mixture of energy excess (hexadecane and energy deficient (glycerol, ethanol substrates on the way of inoculum preparation, concentration of mono-substrates in the mixture, and their molar ratio were determined.

  6. Lack of RsmA-mediated control results in constant hypervirulence, cell elongation, and hyperflagellation in Pectobacterium wasabiae.

    Directory of Open Access Journals (Sweden)

    Viia Kõiv

    Full Text Available The posttranscriptional regulator RsmA controls the production of plant cell wall degrading enzymes (PCWDE and cell motility in the Pectobacterium genus of plant pathogens. In this study the physiological role of gene regulation by RsmA is under investigation. Disruption of rsmA gene of the Pectobacterium wasabiae strain, SCC3193 resulted in 3-fold decrease in growth rate and increased virulence. The comparison of mRNA levels of the rsmA(- mutant and wild-type using a genome-wide microarray showed, that genes responsible for successful infection, i.e. virulence factors, motility, butanediol fermentation, various secretion systems etc. were up-regulated in the rsmA(- strain. The rsmA(- strain exhibited a higher propensity to swarm and produce PCWDE compared to the wild-type strain. Virulence experiments in potato tubers demonstrated that in spite of its more efficient tissue maceration, the rsmA(- strain's ability to survive within the host is reduced and the infection site is taken over by resident bacteria. Taken together, in the absence of RsmA, cells revert to a constitutively infective phenotype characterized by expression of virulence factors and swarming. We hypothesize that lack of control over these costly energetic processes results in decreased growth rate and fitness. In addition, our findings suggest a relationship between swarming and virulence in plant pathogens.

  7. Steam-explosion pretreatment of wood: effect of chip size, acid, moisture content and pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Brownell, H.H.; Yu, E.K.C.; Saddler, J.N.

    1986-06-01

    Material balances for pentosan, lignin, and hexosan, during steam-explosion pretreatment of aspenwood, showed almost quantitative recovery of cellulose in the water-insoluble fraction. Dilute acid impregnation resulted in more selective hydrolysis of pentosan relative to undesirable pyrolysis, and gave a more accessible substrate for enzymatic hydrolysis. Thermocouple probes, located inside simulated aspenwood chips heated in 240 degrees C-saturated steam, showed rapid heating of air-dry wood, whereas green or impregnated wood heated slowly. Small chips, 3.2 mm in the fiber direction, whether green or air dry gave approximately equal rates of pentosan destruction and solubilization, and similar yields of glucose and of total reducing sugars on enzmatic hydrolysis with Trichoderma harzianum. Partial pyrolysis, destroying one-third of the pentosan of aspenwood at atmospheric pressure by dry steam at 276 degrees C, gave little increase in yield of reducing sugars on enzymatic hydrolysis. Treatment with saturated steam at 240 degrees C gave essentially the same yields of butanediol and ethanol on fermentation with Klebsiella pneumoniae, whether or not 80% of the steam was bled off before explosion and even if the chips remained intact, showing that explosion was unnecessary. 17 references.

  8. Bioconversion of xylan for drugs, energy and chemical intermediates%木聚糖生物转化药物、能源和化工中间体

    Institute of Scientific and Technical Information of China (English)

    王海洪; 孙晓锋; 吴耀国

    2011-01-01

    Xylan, the second most abundant polysaccharide compared to cellulose,is a kind of polysaccharide widely existing in the nature. It has tremendous potential applications in many fields, especially in the pharmaceutical,energy and chemicals. Bioconversion with advantages of non-polluting and low-energy consumption expands the applications of xylan. The structure of xylan and itS mechanism of enzymatic lycosylation are introduced. The research on bioconversion of xylan into drugs ( xylo-oligosaccharides and xylitol) , energy ( fuel ethanol and 2, 3-butanediol) , and chemical intermediates ( lactic acid and furfural) are described in detail. Enzymatic species , hacteria , zymotic factors and detective methods are comparably studied as well.%介绍了木聚糖的结构与酶糖化机理,综述了国内外对木聚糖生物转化方面的研究.详细介绍了木聚糖转化为低聚木糖和木糖醇等医药食品、燃料乙醇和2,3-丁二醇等能源物质、乳酸和糠醛等化工中间体的研究进展.

  9. Stereoselective PCO/POC-Rearrangement of P-C-Cage Phosphorane in the Reaction of 4,5-Dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane with Hexafluoroacetone.

    Science.gov (United States)

    Mironov, Vladimir F; Dimukhametov, Mudaris N; Efimov, Sergey V; Aminova, Roza M; Karataeva, Farida Kh; Krivolapov, Dmitry B; Mironova, Ekaterina V; Klochkov, Vladimir V

    2016-07-15

    Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, -40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like phosphoranes with phosphorus-carbon and phosphorus-oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane. PMID:27258739

  10. Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution.

    Science.gov (United States)

    Ji, Xiuling; Tian, Maozhang; Wang, Yilin

    2016-02-01

    The aggregation behaviors of the mixtures of cationic gemini surfactant 1,4-bis(dodecyl-N,N-dimethylammonium bromide)-2,3-butanediol (C12C4(OH)2C12Br2) and anionic amino acid surfactant N-dodecanoylglutamic acid (C12Glu) in aqueous solution of pH = 10.0 have been studied. The mixture forms spherical micelles, vesicles, and wormlike micelles at 25 °C by changing mixing ratios and/or total surfactant concentration. Then these aggregates undergo a series of transitions upon increasing the temperature. Smaller spherical micelles transfer into larger vesicles, vesicles transfer into solid spherical aggregates and then into larger irregular aggregates, and entangled wormlike micelles transfer into branched wormlike micelles. Moreover, the larger irregular aggregates and branched micelles finally lead to precipitation and clouding phenomenon, respectively. All these transitions are thermally reversible, and the transition temperatures can be tuned by varying the mixing ratios and/or total concentration. These temperature-dependent aggregate transitions can be elucidated on the basis of the temperature-induced variations in the dehydration, electrostatic interaction, and hydrogen bonds of the headgroup area and in the hydrophobic interaction between the hydrocarbon chains. The results suggest that the surfactants carrying multiple binding sites will greatly improve the regulation ability and temperature sensitivity. PMID:26750978

  11. Application of shape memory polyurethane in orthodontic.

    Science.gov (United States)

    Jung, Yong Chae; Cho, Jae Whan

    2010-10-01

    A shape memory polymer wire for orthodontic application was prepared by melt-spinning of polyurethane block copolymer (PU) which was synthesized in a two-step process from a reaction of 4,4'-methylene bis(phenylisocyanate), poly(ε-caprolactone)diol (PCL), and 1,4-butanediol. An orthodontic test using the PU wire was carried out in an orthodontic model with a metal bracket. High shape recovery force of 70 gf for PU wire at 40 wt% hard segment content could be preserved for even 1 month after a shape recovery force test at a constant temperature of 50°C. The shape recovery force decreased exponentially during the initial 2 h, but reached an equilibrium shape recovery force of 50 gf after about 20 days. It was found that this shape recovery force was sufficient to correct misaligned teeth in the orthodontic test. The shape memory PU wire possesses strong potential as a novel orthodontic appliance with esthetically appealing appearance.

  12. Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

    Science.gov (United States)

    Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

    2015-10-01

    A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC.

  13. Control of Mechanical Properties of Thermoplastic Polyurethane Elastomers by Restriction of Crystallization of Soft Segment

    Directory of Open Access Journals (Sweden)

    Sadaharu Nakamura

    2010-12-01

    Full Text Available Mechanical properties of thermoplastic polyurethane elastomers based on either polyether or polycarbonate (PC-glycols, 4,4’-dipheylmethane diisocyanate (1,1’-methylenebis(4-isocyanatobenzene, 1,4-butanediol, were controlled by restriction of crystallization of polymer glycols. For the polyether glycol based-polyurethane elastomers (PUEs, poly(oxytetramethylene glycol (PTMG, and PTMG incorporating dimethyl groups (PTG-X and methyl side groups (PTG-L were employed as a polymer glycol. For the PC-glycol, the randomly copolymerized PC-glycols with hexamethylene (C6 and tetramethylene (C4 units between carbonate groups with various composition ratios (C4/C6 = 0/100, 50/50, 70/30 and 90/10 were employed. The degree of microphase separation and mechanical properties of both the PUEs were investigated using differential scanning calorimetry, dynamic viscoelastic property measurements and tensile testing. Mechanical properties could be controlled by changing the molar ratio of two different monomer components.

  14. Revealing the morphological architecture of a shape memory polyurethane by simulation

    Science.gov (United States)

    Hu, Jinlian; Zhang, Cuili; Ji, Fenglong; Li, Xun; Han, Jianping; Wu, You

    2016-07-01

    The lack of specific knowledge of the network structure in shape memory polymers (SMPs) has prevented us from gaining an in-depth understanding of their mechanisms and limited the potential for materials innovation. This paper firstly reveals the unit-cell nanoscale morphological architecture of SMPs by simulation. The phase separated architecture of a segmented shape memory polyurethane (SMPU) with a 30 wt% hard segment content (HSC, 4,4’-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO)) showing good shape memory properties was investigated by dissipative particle dynamics (DPD) simulations. A linked-spherical netpoint-frame phase of MDI, a matrix-switch phase of polycaprolactone (PCL) and a connected-spider-like interphase for BDO were obtained for this SMPU. The BDO interphase can reinforce the MDI network. Based on these simulation results, a three-dimensional (3D) overall morphological architectural model of the SMPU can be established. This theoretical study has verified, enriched and integrated two existing schematic models: one being the morphological model deduced from experiments and the other the frame model for SMPs reported before. It can serve as a theoretical guide for smart polymeric materials design. This method for the simulation of polymer structure at the nanoscale can be extended to many areas such as photonic crystals where nanoscale self-assembly plays a vital role.

  15. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement.

    Science.gov (United States)

    Brochu, Alice B W; Chyan, William J; Reichert, William M

    2012-10-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thickness, content and reactivity of encapsulated agent, and shelf life are investigated and their reliance on solvent type and amount, surfactant type and amount, temperature, pH, agitation rate, reaction time, and mode of addition of the oil phase to the aqueous phase are presented. Capsules had average diameters ranging from 74 to 222 μm and average shell thicknesses ranging from 1.5 to 6 μm. The capsule content was determined via thermogravimetric analysis and subsequent analysis of the capsules following up to 8 weeks storage revealed minimal loss of core contents. Mechanical testing of OCA-containing capsules showed individual capsules withstood compressive forces up to a few tenths of Newtons, and the contents released from crushed capsules generated tensile adhesive forces of a few Newtons. Capsules were successfully mixed into the poly(methyl methacrylate) bone cement, surviving the mixing process, exposure to methyl methacrylate monomer, and the resulting exothermic matrix curing. PMID:22807313

  16. Shape memory polymers based on uniform aliphatic urethane networks

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T S; Bearinger, J P; Herberg, J L; Marion III, J E; Wright, W J; Evans, C L; Maitland, D J

    2007-01-19

    Aliphatic urethane polymers have been synthesized and characterized, using monomers with high molecular symmetry, in order to form amorphous networks with very uniform supermolecular structures which can be used as photo-thermally actuable shape memory polymers (SMPs). The monomers used include hexamethylene diisocyanate (HDI), trimethylhexamethylenediamine (TMHDI), N,N,N{prime},N{prime}-tetrakis(hydroxypropyl)ethylenediamine (HPED), triethanolamine (TEA), and 1,3-butanediol (BD). The new polymers were characterized by solvent extraction, NMR, XPS, UV/VIS, DSC, DMTA, and tensile testing. The resulting polymers were found to be single phase amorphous networks with very high gel fraction, excellent optical clarity, and extremely sharp single glass transitions in the range of 34 to 153 C. Thermomechanical testing of these materials confirms their excellent shape memory behavior, high recovery force, and low mechanical hysteresis (especially on multiple cycles), effectively behaving as ideal elastomers above T{sub g}. We believe these materials represent a new and potentially important class of SMPs, and should be especially useful in applications such as biomedical microdevices.

  17. Theoretical calculation of the OH vibrational overtone spectra of 1-n alkane diols (n = 2-4): origin of disappearing hydrogen-bonded OH peak.

    Science.gov (United States)

    Cheng, Yu-Lung; Chen, Hui-Yi; Takahashi, Kaito

    2011-06-01

    In this theoretical study, we simulated the vibrational overtone spectrum of ethylene glycol (EG), 1-3 propanediol (PD), and 1-4 butanediol (BD). Using the local mode model along with the potential energy curve and dipole moment function calculated by B3LYP/6-31+G(d,p) and QCISD/6-311++G(3df,3pd), we obtained the theoretical peak position and integrated absorption coefficient. Furthermore, the vibrational spectra was simulated using a Voigt function using homogeneous and inhomogenous width obtained from quantum chemical calculation methods. Previously, Howard and Kjaergaard recorded the second and third overtone photoacoustic spectra of the three aforementioned alkane diols in the gas phase and observed that the intramolecular hydrogen bonded OH peak becomes difficult to observe as the intramolecular hydrogen bonding strength increased, that is, as the chain length was increased. In this paper we show that the disappearance of the hydrogen-bonded OH peak for the OH stretching overtone excitation for BD is partly due to the increase in homogeneous width due to the increase in the hydrogen bond strength and partly due to the decrease in the relative population of the intramolecular hydrogen-bonded conformers as the chain length is increased. This latter feature is a consequence of the unfavorable strained geometry needed to form the intramolecular hydrogen bond in longer alkane chains. PMID:21568300

  18. Acetoin catabolism and acetylbutanediol formation by Bacillus pumilus in a chemically defined medium.

    Directory of Open Access Journals (Sweden)

    Zijun Xiao

    Full Text Available BACKGROUND: Most low molecular diols are highly water-soluble, hygroscopic, and reactive with many organic compounds. In the past decades, microbial research to produce diols, e.g. 1,3-propanediol and 2,3-butanediol, were considerably expanded due to their versatile usages especially in polymer synthesis and as possible alternatives to fossil based feedstocks from the bioconversion of renewable natural resources. This study aimed to provide a new way for bacterial production of an acetylated diol, i.e. acetylbutanediol (ABD, 3,4-dihydroxy-3-methylpentan-2-one, by acetoin metabolism. METHODOLOGY/PRINCIPAL FINDINGS: When Bacillus pumilus ATCC 14884 was aerobically cultured in a chemically defined medium with acetoin as the sole carbon and energy source, ABD was produced and identified by gas chromatography--chemical ionization mass spectrometry and NMR spectroscopy. CONCLUSIONS/SIGNIFICANCE: Although the key enzyme leading to ABD from acetoin has not been identified yet at this stage, this study proposed a new metabolic pathawy to produce ABD in vivo from using renewable resources--in this case acetoin, which could be reproduced from glucose in this study--making it the first facility in the world to prepare this new bio-based diol product.

  19. Effect of Hydroxyapatite Nanoparticles on the Degradability of Random Poly(butylene terephthalate-co-aliphatic dicarboxylates Having a High Content of Terephthalic Units

    Directory of Open Access Journals (Sweden)

    Nina Heidarzadeh

    2016-07-01

    Full Text Available Copolyesters derived from 1,4-butanediol and constituted also of aliphatic and aromatic dicarboxylate units in a molar ratio of 3:7 were synthesized by a two-step polycondensation procedure. Succinic, adipic, and sebacic acids were specifically selected as the aliphatic component whereas terephthalic acid was chosen as the aromatic moiety. The second synthesis step was a thermal transesterification between the corresponding homopolymers, always attaining a random distribution as verified by NMR spectroscopy. Hybrid polymer composites containing 2.5 wt % of hydroxyapatite (HAp were also prepared by in situ polymerization. Hydroxyl groups on the nanoparticle surface allowed the grafting of polymer chains in such a way that composites were mostly insoluble in the typical solvents of the parent copolyesters. HAp had some influence on crystallization from the melt, thermal stability, and mechanical properties. HAp also improved the biocompatibility of samples due to the presence of Ca2+ cations and the damping effect of phosphate groups. Interestingly, HAp resulted in a significant increase in the hydrophilicity of samples, which considerably affected both enzymatic and hydrolytic degradability. Slight differences were also found in the function of the dicarboxylic component, as the lowest degradation rates was found for the sample constituted of the most hydrophobic sebacic acid units.

  20. Shrinkage Characteristics of Experimental Polymer Containing Composites under Controlled Light Curing Modes

    Directory of Open Access Journals (Sweden)

    Alain Pefferkorn

    2012-01-01

    Full Text Available The adsorption of polymethylmethacrylate polymer of different molecular weight at the aerosil/ethyleneglycol- or 1,3 butanediol-dimethacrylate interfaces was determined to provide microstructured networks. Their structural characteristics were determined to be controlled by the amount of polymer initially supplied to the system. The sediment (the settled phase characteristics, determined as a function of the polymer concentration and the rate of the polymerization shrinkage determined for composite resins, obtained by extrusion of the sediment after centrifugation, were found to be correlated. The specific role of the adsorbed polymer was found to be differently perturbed with the supplementary supply of dimethacrylate based monomer additives. Particularly, the bisphenol A dimethacrylate that generated crystals within the sediment was found to impede the shrinkage along the crystal lateral faces and strongly limit the shrinkage along its basal faces. Addition of ethyleneglycol- or polyethylene-glycoldimethacrylate monomers was determined to modify the sedimentation characteristics of the aerosil suspension and the shrinkage properties of the composites. Finally, the effects of stepwise light curing methods with prolonged lighting-off periods were investigated and found to modify the development and the final values of the composite shrinkage.

  1. Viticultural practice and winemaking effects on metabolic profile of Negroamaro.

    Science.gov (United States)

    De Pascali, Sandra Angelica; Coletta, Antonio; Del Coco, Laura; Basile, Teodora; Gambacorta, Giuseppe; Fanizzi, Francesco Paolo

    2014-10-15

    Metabolic profiles of 32 Negroamaro red wines were analysed using (1)H NMR spectroscopy and multivariate statistical analyses (Principal Component Analysis, PCA, and Orthogonal Partial Least Square Discriminant Analysis, OPLS-DA). Among winemaking technologies three were compared: ultrasounds (U; 12 samples), cryomaceration using dry ice (C; 12 samples) and traditional (T; 8 samples). Moreover, each vinification technology was used for grapes grown by two different soil management practices, soil tillage (ST; 16 samples) and cover crop (CC; 16 samples), and by two different training systems, monolateral (M; 16 samples) and bilateral Guyot (B; 16 samples). All statistical models applied on NMR data revealed a good separation between ST (soil tillage) and CC (cover crop), showing a higher influence of the soil management practices compared to the winemaking technologies (ultrasound, cryomaceration and traditional). The differentiation among samples, due to soil management practices, was mainly caused by metabolites such as glycerol, 2,3-butanediol, malic acid, α/β-glucose and phenolic compounds, such as tyrosine and caffeic acid.

  2. Transparent large-strain thermoplastic polyurethane magnetoactive nanocomposites.

    Science.gov (United States)

    Yoonessi, Mitra; Peck, John A; Bail, Justin L; Rogers, Richard B; Lerch, Bradley A; Meador, Michael A

    2011-07-01

    Organically modified superparamagnetic MnFe(2)O(4)/thermoplastic polyurethane elastomer (TPU) nanocomposites (0.1-8 wt %) were prepared by solvent mixing followed by solution casting. Linear aliphatic alkyl chain modification of spherical MnFe(2)O(4) provided compatibility with the TPU containing a butanediol extended polyester polyol-MDI. All MnFe(2)O(4)/TPU nanocomposite films were superparamagnetic and their saturation magnetization, σ(s), increased with increasing MnFe(2)O(4) content. All nanocomposite films exhibited large deformations (>10 mm) under a magneto-static field. This is the first report of large actuation of magnetic nanoparticle nanocomposites at low-loading levels of 0.1 wt % (0.025 vol %). The maximum actuation deformation of the MnFe(2)O(4)/TPU nanocomposite films increased exponentially with increasing nanoparticle concentration. An empirical correlation between the maximum displacement, saturation magnetization, and magnetic nanoparticle loading is proposed. The cyclic deformation actuation of a 6 wt % surface modified MnFe(2)O(4)/TPU, in a low magnetic field 151 < B(y) < 303 Oe, exhibited excellent reproducibility and controllability. MnFe(2)O(4)/TPU nanocomposite films (0.1-2 wt %) were transparent and semitransparent over the wavelengths from 350 to 700 nm. PMID:21710967

  3. Effect of filler surface properties on stress relaxation behavior of carbon nanofiber/polyurethane nanocomposites

    Science.gov (United States)

    Sedat Gunes, I.; Jimenez, Guillermo; Jana, Sadhan

    2009-03-01

    The effect of carbon nanofiber (CNF) surface properties on tensile stress relaxation behavior of CNF/polyurethane (PU) nanocomposites was analyzed. PU was synthesized from methylene diisocyanate, polypropylene glycol (PPG diol), and butanediol. CNF, oxidized CNF (ox-CNF), and PPG diol grafted CNF (ol-CNF) were selected as fillers. ol-CNF was obtained by grafting PPG diol onto ox-CNF by reacting it with the carboxyl groups present on ox-CNF surface. The atomic ratios of oxygen to carbon present on the filler surfaces were 0.13 and 0.18 on ox-CNF and on ol-CNF as compared to 0.015 on CNF, mostly due to the presence oxygen containing polar groups on the surfaces of the former. The composites were prepared by in-situ polymerization and melt mixing in a chaotic mixer. The stress relaxation behavior of composites was determined at room temperature after inducing a tensile strain of 100%. The presence of fillers augmented the rate of stress relaxation in composites which was highest in the presence of CNF. The results suggested that relatively weak polymer-filler interactions in composites of CNF promoted higher stress relaxation.

  4. Novel monosaccharide fermentation products in Caldicellulosiruptor saccharolyticus identified using NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Isern, Nancy G.; Xue, Junfeng; Rao, Jaya V.; Cort, John R.; Ahring, Birgitte K.

    2013-04-03

    Profiles of metabolites produced by the thermophilic obligately anaerobic cellulose-degrading Gram-positive bacterium Caldicellulosiruptor saccharolyticus DSM 8903 strain following growth on different monosaccharides (D-glucose, D-mannose, L-arabinose, D-arabinose, D-xylose, L-fucose, and D-fucose) as carbon sources revealed several unexpected fermentation products, suggesting novel metabolic capacities and unexplored metabolic pathways in this organism. Both 1H and 13C nuclear magnetic resonance (NMR) spectroscopy were used to determine intracellular and extracellular metabolite profiles. Metabolite profiles were determined from 1-D 1H NMR spectra by curve fitting against spectral libraries provided in Chenomx software. To reduce uncertainties due to unassigned, overlapping, or poorly-resolved peaks, metabolite identifications were confirmed with 2-D homonuclear and heteronuclear NMR experiments. In addition to expected metabolites such as acetate, lactate, glycerol, and ethanol, several novel fermentation products were identified: ethylene glycol (from growth on D-arabinose, though not L-arabinose), acetoin and 2,3-butanediol (from D-glucose and L-arabinose), and hydroxyacetone (from D-mannose and L-arabinose). Production of ethylene glycol from D-arabinose was particularly notable, with around 10% of the substrate carbon converted into this uncommon fermentation product. The novel products have not previously been reported to be produced by C. saccharolyticus, nor would they be easily predicted from the current genome annotation, and show new potentials for using this strain for production of bioproducts.

  5. New aliphatic glycerophosphoryl-containing polyurethanes: synthesis, platelet adhesion and elution cytotoxicity studies.

    Science.gov (United States)

    Acetti, Daniela; D'Arrigo, Paola; Giordano, Carmen; Macchi, Piero; Servi, Stefano; Tessaro, Davide

    2009-04-01

    in this study new poly(ether)urethanes (PeUs) based on aliphatic diisocyanates were synthesized with phospholipid-like residues as chain extenders. The primary objective was to prepare new polyurethanes from diisocyanates that are less toxic than the aromatic ones widely used in medical-grade polyurethanes, in order to investigate the effect of the different aromatic or aliphatic hard segment content on the final properties of the materials. Some glycerophospho residues were simultaneously introduced to enhance the hemocompatibility of these materials. Polymers were prepared by a conventional two-step solution polymerization procedure using hexamethylene diisocyanate (HDi) and dodecametilendiisocyanate (DDi) and poly(1,4-butanediol) with molecular weight 1000 to form prepolymers, which were subsequently polymerized with 1-glycerophosphorylcholine (1-GPC) or glycerophosphorylserine (GPS) to act as chain extenders. The reference polymers bearing 1,4-butandiol (BD) were also synthesized. The polymers obtained were characterized by fourier transform infrared spectroscopy (fT-iR), nuclear magnetic resonance (1H nmR), and differential scanning calorimetry (DSC). The hemocompatibility of synthesized segmented polyurethanes was preliminarily investigated by platelet-rich plasma contact studies and related scanning electron microscopy (Sem) photographs as well as by cell viability assay after cell exposure to material elutions to assess the effect of any toxic leachables coming out from the samples. Two of the polymers gave interesting results, suggesting the desirability of further investigation into their possible use in biomedical devices. PMID:19569028

  6. Synthesis, extrusion and rheological behaviour of PU/HA composites for biomedical applications.

    Science.gov (United States)

    Machado, H B; Correia, Rui N; Covas, J A

    2010-07-01

    Biostable polyurethane/hydroxyapatite (PU/HA) composites with potential application as bone replacement materials were synthesized in bulk and processed in a screw extruder. The polyurethanes (PU) were prepared by reacting an aliphatic diisocyanate, 4-methylene-bis-diisocyanate (MDI), with poly-(epsilon-caprolactone) (PCL) diols and polytetramethylene oxide (PTMO) of different molecular weights, extended with 1, 4-butanediol (BDO). Glass-transition temperatures were measured by differential scanning calorimetry (DSC). The specific PU groups were assessed by total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The effects of polymer chemistry and filler content on the rheological behaviour were studied by oscillatory rheometry. Polymers with larger chain lengths showed higher viscosity and, for identical chain lengths, polyether urethanes seem to have higher viscosities than polyester based urethanes. A lubricating effect was found for composites containing 50% weight of filler, whereas at higher filler contents a solid-like behaviour was measured. Polymer chemistry seems to be affected by ageing but not so by the presence of filler. Ageing is characterized by a decrease in the concentration of hydrogen bonds involving between urethane linkages. PMID:20405172

  7. POLYURETHANE COMPOSITES AS DRUG CARRIERS:: RELEASE PATTERNS

    Directory of Open Access Journals (Sweden)

    M. V. Grigoreva

    2013-10-01

    Full Text Available Biodegradable polyurethanes attract interest of those developing composite materials for biomedical applications. One of their features is their ability to serve as carriers, or matrixes, for medicines and other bioactive compounds to produce a therapeutic effect in body through targeted and/or prolonged delivery of these compounds in the process of their controlled release from matrix. The review presents polyurethane composites as matrices for a number of drugs. The relation between structure of the composites and their degradability both in vitro and in vivo and the dependence of drug release kinetics on physicochemical properties of polyurethane matrix are highlighted. The release of drugs (cefazolin, naltrexone and piroxicam from the composites based on cross-linked polyurethanes (synthesized from laprols, Mw between 1,500 and 2,000 Da and toluylene diisocyanate demonstrated more or less the same pattern (about 10 days in vitro and three to five days in vivo. In contrast, the composites with dioxydine based on a linear polyurethanes (synthesized from oligotetramethilene glycol, Mw 1,000 Da, diphenylmethane-4,4’-diisocyanate and 1,4-butanediol retained their antimicrobial activity at least 30 days. They also showed a significantly higher breaking strength as compared to that of the composites based on cross-linked polyurethanes.

  8. Exploring mild enzymatic sustainable routes for the synthesis of bio-degradable aromatic-aliphatic oligoesters.

    Science.gov (United States)

    Pellis, Alessandro; Guarneri, Alice; Brandauer, Martin; Acero, Enrique Herrero; Peerlings, Henricus; Gardossi, Lucia; Guebitz, Georg M

    2016-05-01

    The application of Candida antarctica lipase B in enzyme-catalyzed synthesis of aromatic-aliphatic oligoesters is here reported. The aim of the present study is to systematically investigate the most favorable conditions for the enzyme catalyzed synthesis of aromatic-aliphatic oligomers using commercially available monomers. Reaction conditions and enzyme selectivity for polymerization of various commercially available monomers were considered using different inactivated/activated aromatic monomers combined with linear polyols ranging from C2 to C12 . The effect of various reaction solvents in enzymatic polymerization was assessed and toluene allowed to achieve the highest conversions for the reaction of dimethyl isophthalate with 1,4-butanediol and with 1,10-decanediol (88 and 87% monomer conversion respectively). Mw as high as 1512 Da was obtained from the reaction of dimethyl isophthalate with 1,10-decanediol. The obtained oligomers have potential applications as raw materials in personal and home care formulations, for the production of aliphatic-aromatic block co-polymers or can be further functionalized with various moieties for a subsequent photo- or radical polymerization.

  9. Determinação do parâmetro de solubilidade de poliuretanos de PBLH Solubility parameter of HTPB polyurethanes determination

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    Eder M. Santos

    2000-06-01

    Full Text Available O parâmetro de solubilidade de poliuretanos segmentados foi determinado através de ensaios de inchamento no equilíbrio, tratando-se os dados pela teoria de Flory-Rehner. O segmento flexível dos poliuretanos foi constituído por blocos de oligobutadieno e o segmento rígido foi formado pela reação entre di-isocianato de tolileno e os extensores de cadeia 1,3-propanodiol; 1,4-butanodiol; 1,6-hexanodiol e 2, 2'-di-hidroxi-isopropil N, N'anilina. O teor em segmento rígido para os polímeros provenientes dos extensores alifáticos ficou na faixa de 25,1% a 28,3%, enquanto que, nos polímeros estendidos com o extensor aromático, foi de 32,6%.The solubility parameter of a series of segmented polyurethanes was determined through equilibrium swelling experiments, using the Flory-Rehner theory. The soft segment of the polyurethanes was oligobutadiene and the hard block was formed through the reaction of tolylene diisocyanate with propanediol, butanediol, hexanediol or 2, 2' dihydroxy isopropyl N, N' aniline. The hard segment content in all polymers was about the same for the aliphatic extenders (25.1% to 28.3% and 32.6% for the aromatic one.

  10. Magnetic properties evolution of the CoxFe3-xO4/SiO2 system due to advanced thermal treatment at 700 °C and 1000 °C

    Science.gov (United States)

    Dippong, Thomas; Levei, Erika Andrea; Tanaselia, Claudiu; Gabor, Mihai; Nasui, Mircea; Barbu Tudoran, Lucian; Borodi, Gheorghe

    2016-07-01

    The CoxFe3-xO4 (x=0.5-2.5) system embedded in the silica matrix was synthesised by sol-gel method using cobalt nitrate, iron nitrate, 1.4-butanediol and tetraethyl orthosilicate. Five different Co/Fe molar ratios in the presence of diol and one without diol were used for the synthesis. The obtained gels were subjected to thermal treatment at 700 °C and 1000 °C. The oxide species formed in the silica matrix, the optimum temperature for the CoFe2O4 phase formation, the evolution of nanocrystallites size and magnetic properties with the calcination temperature were studied. The formed oxide species were studied using X-ray diffraction, Fourier transformed infrared spectrometry, the Co/Fe molar ratio was confirmed using inductively coupled plasma optical emission spectrometry, the nanocrystallites size, shape and clustering was identified by transmission electron microscopy and scanning electron microscopy, while the formation of magnetic phases was investigated by hysteresis and magnetization derivatives measurements.

  11. Microchip free flow planar reversed phase electrochromatography with monolithic stationary phase.

    Science.gov (United States)

    Wang, Pingli; Tao, Dingyin; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2009-08-01

    In this study, microchip free flow planar RP electrochromatography (microFF-PRPEC) was developed by in situ polymerization of monolithic materials in microchamber, and successfully applied for the separation of dyes and proteins. Poly(butyle methyacrylate-co-ethylene dimethacrylate) was prepared by UV-initiated polymerization in a glass microchamber (42 mm long, 23 mm wide, and 28 microm deep). A mixture of 1-propanol, 1,4-butanediol, and water was chosen as porogens, and 1.2% (wt%) 2-acrylamide-2-methyl-propanesulfonic acid (AMPS) was added into the polymerization solution to generate EOF. With 30% v/v ACN-15 mM Tris-HCl as the mobile phase, rhodamine B and methyl green were separated from each other with 400 V transverse voltage applied, and resolution as high as 4.6 was obtained, much higher than that obtained by microFFE under optimal conditions. Furthermore, microFF-PRPEC was also successfully applied into the separation of lysozyme and ribonuclease B, and resolution as high as 9.4 was obtained. All these results demonstrate that microFF-RPPEC might have great potential in the microscale continuous preparation of samples with improved resolution compared to microFFE.

  12. Biodegradation of Synthetic Polyesters (BTA and PCL with Natural Flora in Soil Burial and Pure Cultures under Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Mona K. Gouda

    2012-03-01

    Full Text Available The aim of this study was to study the biodegradation of two synthetic polyesters, one aliphaticaromatic (1, 4-butanediol, terephthalic-adipic acid, BTA and the other aliphatic (poly (,-caprolactone, PCL, under different soil types (canal shore soil, garden soil, compost and Peat moss, respectively, as well as using locally isolated cultures at ambient temperature. The results showed that the BTA films buried in canal shore and garden soil were degraded faster than that in the other soils. After six weeks about 90, 88 and 80% were degraded in garden, canal shore soil and compost respectively, while only 52% were degraded in Peat moss. On the other hand, 95 and 93% weight loss was obtained for PCL films buried for three weeks in canal shore and garden soil respectively. The Scanning Electron Microscope photos confirm the results of weight loss and revealed the presence of cracks and fungal growth on films buried in different soils. The results with pure cultures, especially with Fusarium solani, also confirmed the biodegradability of two polyesters under ambient temperature. Finally, it could be concluded that both synthetic polyester are degradable under ambient conditions.

  13. (1)H NMR-based metabolomic approach for understanding the fermentation behaviors of wine yeast strains.

    Science.gov (United States)

    Son, Hong-Seok; Hwang, Geum-Sook; Kim, Ki Myong; Kim, Eun-Young; van den Berg, Frans; Park, Won-Mok; Lee, Cherl-Ho; Hong, Young-Shick

    2009-02-01

    (1)H NMR spectroscopy coupled with multivariate statistical analysis was used for the first time to investigate metabolic changes in musts during alcoholic fermentation and wines during aging. Three Saccharomyces cerevisiae yeast strains (RC-212, KIV-1116, and KUBY-501) were also evaluated for their impacts on the metabolic changes in must and wine. Pattern recognition (PR) methods, including PCA, PLS-DA, and OPLS-DA scores plots, showed clear differences for metabolites among musts or wines for each fermentation stage up to 6 months. Metabolites responsible for the differentiation were identified as valine, 2,3-butanediol (2,3-BD), pyruvate, succinate, proline, citrate, glycerol, malate, tartarate, glucose, N-methylnicotinic acid (NMNA), and polyphenol compounds. PCA scores plots showed continuous movements away from days 1 to 8 in all musts for all yeast strains, indicating continuous and active fermentation. During alcoholic fermentation, the highest levels of 2,3-BD, succinate, and glycerol were found in musts with the KIV-1116 strain, which showed the fastest fermentation or highest fermentative activity of the three strains, whereas the KUBY-501 strain showed the slowest fermentative activity. This study highlights the applicability of NMR-based metabolomics for monitoring wine fermentation and evaluating the fermentative characteristics of yeast strains.

  14. Evaluation of the Mechanical Properties of Microcapsule-Based Self-Healing Composites

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    Liberata Guadagno

    2016-01-01

    Full Text Available Self-healing materials are beginning to be considered for applications in the field of structural materials. For this reason, in addition to self-healing efficiency, also mechanical properties such as tensile and compressive properties are beginning to become more and more important for this kind of materials. In this paper, three different systems based on epoxy-resins/ethylidene-norbornene (ENB/Hoveyda-Grubbs 1st-generation (HG1 catalyst are investigated in terms of mechanical properties and healing efficiency. The experimental results show that the mechanical properties of the self-healing systems are mainly determined by the chemical nature of the epoxy matrix. In particular, the replacement of a conventional flexibilizer (Heloxy 71 with a reactive diluent (1,4-butanediol diglycidyl ether allows obtaining self-healing materials with better mechanical properties and higher thermal stability. An increase in the curing temperature causes an increase in the elastic modulus and a slight reduction of the healing efficiency. These results can constitute the basis to design systems with high regenerative ability and appropriate mechanical performance.

  15. Whole genome analysis of halotolerant and alkalotolerant plant growth-promoting rhizobacterium Klebsiella sp. D5A.

    Science.gov (United States)

    Liu, Wuxing; Wang, Qingling; Hou, Jinyu; Tu, Chen; Luo, Yongming; Christie, Peter

    2016-01-01

    This research undertook the systematic analysis of the Klebsiella sp. D5A genome and identification of genes that contribute to plant growth-promoting (PGP) traits, especially genes related to salt tolerance and wide pH adaptability. The genome sequence of isolate D5A was obtained using an Illumina HiSeq 2000 sequencing system with average coverages of 174.7× and 200.1× using the paired-end and mate-pair sequencing, respectively. Predicted and annotated gene sequences were analyzed for similarity with the Kyoto Encyclopedia of Genes and Genomes (KEGG) enzyme database followed by assignment of each gene into the KEGG pathway charts. The results show that the Klebsiella sp. D5A genome has a total of 5,540,009 bp with 57.15% G + C content. PGP conferring genes such as indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, siderophore production, acetoin and 2,3-butanediol synthesis, and N2 fixation were determined. Moreover, genes putatively responsible for resistance to high salinity including glycine-betaine synthesis, trehalose synthesis and a number of osmoregulation receptors and transport systems were also observed in the D5A genome together with numerous genes that contribute to pH homeostasis. These genes reveal the genetic adaptation of D5A to versatile environmental conditions and the effectiveness of the isolate to serve as a plant growth stimulator.

  16. Activity of nanosized titania synthesized from thermal decomposition of titanium (IV n-butoxide for the photocatalytic degradation of diuron

    Directory of Open Access Journals (Sweden)

    Jitlada Klongdee, Wansiri Petchkroh, Kosin Phuempoonsathaporn, Piyasan Praserthdam, Alisa S. Vangnai and Varong Pavarajarn

    2005-01-01

    Full Text Available Nanoparticles of anatase titania were synthesized by the thermal decomposition of titanium (IV n-butoxide in 1,4-butanediol. The powder obtained was characterized by various characterization techniques, such as XRD, BET, SEM and TEM, to confirm that it was a collection of single crystal anatase with particle size smaller than 15 nm. The synthesized titania was employed as catalyst for the photodegradation of diuron, a herbicide belonging to the phenylurea family, which has been considered as a biologically active pollutant in soil and water. Although diuron is chemically stable, degradation of diuron by photocatalyzed oxidation was found possible. The conversions achieved by titania prepared were in the range of 70–80% within 6 h of reaction, using standard UV lamps, while over 99% conversion was achieved under solar irradiation. The photocatalytic activity was compared with that of the Japanese Reference Catalyst (JRC-TIO-1 titania from the Catalysis Society of Japan. The synthesized titania exhibited higher rate and efficiency in diuron degradation than reference catalyst. The results from the investigations by controlling various reaction parameters, such as oxygen dissolved in the solution, diuron concentration, as well as light source, suggested that the enhanced photocatalytic activity was the result from higher crystallinity of the synthesized titania.

  17. Scientific Opinion on the re-evaluation of montan acid esters (E 912 as a food additive

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    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS

    2013-06-01

    Full Text Available Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS was asked to deliver a scientific opinion re-evaluating the safety of montan acid esters (E 912 when used as a food additive. Montan acids are extracted from oxidised montan wax and esterified with ethylene glycol, 1,3-butanediol or triols, to form montan acid esters. Montan acid esters are authorised only for the surface treatment of fresh fruits. No data, specifically for montan acid esters, on toxicokinetics and reproductive and developmental toxicity were available. The available data on short-term and subchronic toxicity, genotoxicity and chronic toxicity and carcinogenicity were limited. Important deficiencies in the available studies on chronic toxicity and carcinogenicity were noticed. The data requested in the 1990s (i.e. chromosomal aberration in vitro, reproduction and teratogenicity studies, material characteristics, impurities, presence of PAHs were not submitted. Furthermore no data were submitted following an EFSA public call for data in 2012. The Panel identified some summary data in the European Chemicals Agency database (ECHA on registered substances that might have been relevant for the assessment of montan acid esters but the original study reports were not made available to EFSA. Based on these limitations in the toxicological database the Panel concluded that montan acid esters as a food additive could not be evaluated.

  18. Manufacturing of biodegradable polyurethane scaffolds based on polycaprolactone using a phase separation method: physical properties and in vitro assay

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    Asefnejad A

    2011-10-01

    Full Text Available Azadeh Asefnejad1, Mohammad Taghi Khorasani2, Aliasghar Behnamghader3, Babak Farsadzadeh1, Shahin Bonakdar4 1Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran; 2Iran Polymers and Petrochemical Institute, Tehran, Iran; 3Materials and Energy Research Center, Tehran, Iran; 4National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran Background: Biodegradable polyurethanes have found widespread use in soft tissue engineering due to their suitable mechanical properties and biocompatibility. Methods: In this study, polyurethane samples were synthesized from polycaprolactone, hexamethylene diisocyanate, and a copolymer of 1,4-butanediol as a chain extender. Polyurethane scaffolds were fabricated by a combination of liquid–liquid phase separation and salt leaching techniques. The effect of the NCO:OH ratio on porosity content and pore morphology was investigated. Results: Scanning electron micrographs demonstrated that the scaffolds had a regular distribution of interconnected pores, with pore diameters of 50–300 µm, and porosities of 64%–83%. It was observed that, by increasing the NCO:OH ratio, the average pore size, compressive strength, and compressive modulus increased. L929 fibroblast and chondrocytes were cultured on the scaffolds, and all samples exhibited suitable cell attachment and growth, with a high level of biocompatibility. Conclusion: These biodegradable polyurethane scaffolds demonstrate potential for soft tissue engineering applications. Keywords: polyurethane, tissue engineering, biodegradable, fibroblast cells

  19. Determination of gamma-hydroxybutyrate (GHB) and its precursors in blood and urine samples: a salting-out approach.

    Science.gov (United States)

    Kankaanpää, Aino; Liukkonen, Raija; Ariniemi, Kari

    2007-08-01

    Gamma-hydroxybutyrate (GHB) is an increasingly popular drug of abuse that causes stimulation, euphoria, anxiolysis or hypnosis, depending on the dose used. Low doses of the drug are used recreationally, and also implicated in drug-facilitated sexual assaults. Because of the unusually steep dose-response curves, accidental GHB overdosing, leading to coma, seizures or death can occur. Being a controlled substance, GHB is often substituted with its non-scheduled precursors gamma-butyrolactone (GBL) and 1,4-butanediol (BD), which are rapidly metabolized into GHB in the body. Here we describe an assay for GHB, GBL and BD in blood and/or urine samples. GHB and BD were extracted from diluted 200 microL aliquots of samples with t-butylmethylether (plus internal standard benzyl alcohol) in test tubes preloaded with NaCl. After acidification and centrifugation the solvent phase was transferred to a test tube preloaded with Na(2)SO(4), incubated for 30 min, centrifuged again, and evaporated in vacuum. The residue was mixed with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) in acetonitrile, and injected into a GC-MS. When analyzing GBL, the salting-out step was omitted, and analysis was performed with a GC-FID apparatus. As revealed by the validation data this procedure is suitable for quantitative determination of GHB and its precursors in blood and/or urine samples. PMID:17658710

  20. Data on synthesis of oligomeric and polymeric poly(butylene adipate-co-butylene terephthalate model substrates for the investigation of enzymatic hydrolysis

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    Veronika Perz

    2016-06-01

    Full Text Available The aliphatic-aromatic copolyester poly(butylene adipate-co-butylene terephthalate (PBAT, also known as ecoflex, contains adipic acid, 1,4-butanediol and terephthalic acid and is proven to be compostable [1–3]. We describe here data for the synthesis and analysis of poly(butylene adipate-co-butylene terephthalate variants with different adipic acid:terephatalic acid ratios and 6 oligomeric PBAT model substrates. Data for the synthesis of the following oligomeric model substrates are described: mono(4-hydroxybutyl terephthalate (BTa, bis(4-(hexanoyloxybutyl terephthalate (HaBTaBHa, bis(4-(decanoyloxybutyl terephthalate (DaBTaBDa, bis(4-(tetradecanoyloxybutyl terephthalate (TdaBTaBTda, bis(4-hydroxyhexyl terephthalate (HTaH and bis(4-(benzoyloxybutyl terephthalate (BaBTaBBa. Polymeric PBAT variants were synthesized with adipic acid:terephatalic acid ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. These polymeric and oligomeric substances were used as ecoflex model substrates in enzymatic hydrolysis experiments in the article “Substrate specificities of cutinases on aliphatic-aromatic polyesters and on their model substrates” [4].

  1. Gelatin-Modified Polyurethanes for Soft Tissue Scaffold

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    Justyna Kucińska-Lipka

    2013-01-01

    Full Text Available Recently, in the field of biomaterials for soft tissue scaffolds, the interest of their modification with natural polymersis growing. Synthetic polymers are often tough, and many of them do not possess fine biocompatibility. On the other hand, natural polymers are biocompatible but weak when used alone. The combination of natural and synthetic polymers gives the suitable properties for tissue engineering requirements. In our study, we modified gelatin synthetic polyurethanes prepared from polyester poly(ethylene-butylene adipate (PEBA, aliphatic 1,6-hexamethylene diisocyanate (HDI, and two different chain extenders 1,4-butanediol (BDO or 1-ethoxy-2-(2-hydroxyethoxyethanol (EHEE. From a chemical point of view, we replaced expensive components for building PU, such as 2,6-diisocyanato methyl caproate (LDI and 1,4-diisocyanatobutane (BDI, with cost-effective HDI. The gelatin was added in situ (in the first step of synthesis to polyurethane to increase biocompatibility and biodegradability of the obtained material. It appeared that the obtained gelatin-modified PU foams, in which chain extender was BDO, had enhanced interactions with media and their hydrolytic degradation profile was also improved for tissue engineering application. Furthermore, the gelatin introduction had positive impact on gelatin-modified PU foams by increasing their hemocompatibility.

  2. Synthesis of thermoplastic poly(ester-siloxanes in the melt and in solution

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    BILJANA P. DOJCINOVIC

    2005-12-01

    Full Text Available Two series of thermoplastic elastomers, based on poly(dimethylsiloxane, PDMS, as the soft segment and poly(butylene terephthalate, PBT, as the hard segment, were synthesized by catalyzed transesterification, from dimethyl terephthalate, DMT, silanol-terminated poly(dimethylsiloxane, PDMS-OH, Mn = 1750 g/mol, and 1,4-butanediol, BD. The mole ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 55:45. The first series was synthesized in order to determine the optimal mole ratio of BD and DMT for the synthesis of high molecular weight thermoplastic poly(ester-siloxanes, TPESs. The second series was performed in the presence of the high-boiling solvent, 1,2,4-trichlorbenzene in order to increase the mixing between the extremely non-polar siloxane prepolymer and the polar reactants, DMT and BD, and, therefore, avoid phase separation during synthesis. The structure and composition of the synthesized poly(ester- siloxanes were verified by 1H-NMR spectroscopy, while the melting temperatures and degree of crystallinity were determined by differential scanning calorimetry (DSC. The effectiveness of the incorporation of the silanol-terminated poly( dimethylsiloxane into the polyester chains was verified by chloroform extraction. The rheological properties of the poly(ester-siloxanes were investigated by dynamic mechanical spectroscopy (DMA.

  3. Application of reactive siloxane prepolymers for the synthesis of thermoplastic poly(ester–siloxanes and poly(ester–ether–siloxanes

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    VESNA V. ANTIC

    2007-02-01

    Full Text Available Thermoplastic poly(ester–siloxanes (TPES and poly(ester–ether–siloxane s, (TPEES, based on poly(butylene terephthalate (PBT as the hard segment and different siloxane-prepolymers as the soft segments, were prepared. The TPES and TPEES were synthesized by catalyzed two-step transesterification from dimethyl terephthalate, (DMT, 1,4-butanediol, (BD and a siloxane-prepolymer. Incorporation of dicarboxypropyl- or disilanol-terminated poly(dimethylsiloxanes (PDMS into the polar poly(butylene terephthalate chains resulted in rather inhomogeneous TPES copolymers, which was a consequence of a prononuced phase separation of the polar and non-polar reactants during synthesis. Two concepts were employed to avoid or reduce phase separation: 1 the use of siloxane-containing triblock prepolymers with hydrophilic terminal blocks, such as ethylene oxide (EO, poly(propylene oxide (PPO or poly(caprolactone (PLC when the terminal blocks serve as a compatibilizer between the extremely non-polar PDMS and the polar DMT and BD, and 2 the use of a high-boiling solvent (1,2,4-trichlorobenzene during the first phase of the reaction. Homogeneity was significantly improved in the case of copolymers based on PCL–PDMS–PCL.

  4. Morphology and mechanical properties of TPU nanoclay composites;Morfologia e propriedades mecanicas de compositos de TPU com argila

    Energy Technology Data Exchange (ETDEWEB)

    Pizatto, Leandro [Autotravi Borrachas e Plasticos Ltda, Caxias do Sul, RS (Brazil); Fiorio, Rudinei; Amorim, Cintia L.G.; Giovanela, Marcelo; Machado, Giovanna; Zattera, Ademir J.; Crespo, Janaina S., E-mail: jscrespo@ucs.b [Universidade de Caxias do Sul (UCS), RS (Brazil). Centro de Ciencias Exatas e Tecnologia

    2009-07-01

    In this study thermoplastic polyurethane (TPU) composites were obtained with different contents (0, 1, 3 for all cases and 10 wt % in some cases). The nanoclay Cloisite 30B (C 30B) was dispersed in the TPU matrix by melt processing (twin-screw extruder; TPU-E composites) and during bulk polymerization (TPU-S composites). The synthesis method involved the two-step bulk polymerization of polyester polyol (molecular weight 2.000 g mol-1) and diphenylmethanediisocyanate with 1,4-butanediol as the chain extender. The dispersion state of the nanoclay particles and its effect on the mechanical properties of the composites was investigated. The characterization of TPU/nanoclay composites was carried out by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical characterization was carried out by means of tensile and tear strengths test. The TPU-E 3 wt % composite showed the best improvement with increases in stress and strain at break (28% and 35%, respectively) and energy (88%), compared to the TPU-E (sample without nanoclay). (author)

  5. Enzyme-catalyzed organic syntheses: transesterification reactions of chlorophyl a, bacteriochlorophyll a, and derivatives with chlorophyllase

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, T.J.; Hunt, J.E.; Bradshaw, C.; Wagner, A.M.; Norris, J.R.; Katz, J.J.

    1988-08-17

    The green plant enzyme chlorophyllase (EC 3.1.1.14, chlorophyll chlorophyllido-hydroase) has been used for the synthesis of a variety of primary alcohol and diol esters of chlorophyll a, bacteriochlorophyll a, and pyrobacteriochlorophyll a. Green plant chlorophyllase accepts a much larger range of alcohol and chlorophyll substrates than had previously been realized. Thus, chlorophyllide and bacteriochlorophyllide esters of primary alcohols such as retinol and the detergent Triton X-100 and of dihydric alcohols such as ethylene glycol, butanediol, or 2-hydroxyethyl disulfide can readily be obtained by enzyme-assisted transesterification. The diol chlorophyllide esters are valuable intermediates for the synthesis of reaction center special pair models. Chlorophyllase-assisted reactions can be carried out in media containing up to 95% of organic solvents without the concomitant side reactions that important chlorophyll functional groups readily undergo even under mild conditions in conventional chemical synthetic procedures. In competitive chlorophyllase-catalyzed transesterification reactions, long-chain alcohols such as farnesol and retinol vs simple aliphatic alcohols and diols, the enzyme shows a definite preference for the long-chain alcohol. 37 references, 1 figure, 2 tables.

  6. Synthesis of graphene oxide grafted poly(lactic acid) with palladium nanoparticles and its application to serotonin sensing

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hyoung Soon; You, Jung-Min; Jeong, Haesang; Jeon, Seungwon, E-mail: swjeon3380@naver.com

    2013-11-01

    Graphene oxide (GO) has treated with methylene diphenyl diisocyanate (MDI) and subsequent 1,4-butanediol (BD) to create an anchoring OH site on the surface of GO (GO-MDI-OH). The OH groups of GO-MDI-OH were the initiators of the polymerization of poly(lactic acid) (PLA). The subsequent GO-g-PLA was synthesized by the polymerization reaction in the presence of GO-MDI-OH and PLA. The synthesized materials were characterized via {sup 1}H-NMR, Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis (differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA)). The surface morphologies and degree of dispersions at G-g-PLA-metals were observed using a field emission scanning electron microscope (FE-SEM) and a transmission electron microscopy (TEM). The electrical conductivity of G-g-PLA-Pd was largely enhanced compared with those of GO and GO-g-PLA. G-g-PLA-Pd was used for the electrochemical detection of serotonin. Electrocatalytic activities were verified from the cyclic voltammetry (CV) and amperometric response in a 0.1 M phosphate buffer solution (PBS). A significantly higher concentration range (0.1–100.0 μM) and a lower detection limit (8.0 × 10{sup −8} M, where s/n = 3) were found at the G-g-PLA-Pd modified glassy carbon electrode (GCE).

  7. Production of a polyester degrading extracellular hydrolase from Thermomonospora fusca.

    Science.gov (United States)

    Gouda, Mona K; Kleeberg, Ilona; van den Heuvel, Joop; Müller, Rolf-Joachim; Deckwer, Wolf-Dieter

    2002-01-01

    The production of a polyester-degrading hydrolase from the thermophilic actinomycete Thermomonospora fusca was investigated with regard to its potential technical application. Only in the presence of a polyester (random aliphatic-aromatic copolyester from 1,4-butanediol, terephthalic acid, and adipic acid with around 40-50 mol % terephthalic acid in the acid component), the excretion of the extracellular enzyme could be achieved with an optimized synthetic medium using pectin and NH(4)Cl as nitrogen source. Compared to complex media, a significantly higher specific activity at comparable volumetric yields could be obtained, thus reducing the expenditure for purification. The activity profile in the medium is controlled by a complex process involving (1) induction of enzyme excretion, (2) enzyme adsorption on the hydrophobic polyester surface, (3) inhibition of enzyme generation by monomers produced by polyester cleavage, and (4) enzyme denaturation. Diafiltration with cellulose acetate membranes as the sole downstream processing step led to a product of high purity and with sufficient yield (60% of total activity). Scaling-up from shaking flasks to a fermentor scale of 100 L revealed no specific problems. However, the excretion of the hydrolase by the actinomycete turned out to be inhibited by the degradation products (monomers) of the aliphatic-aromatic copolyester used as inductor for the enzyme production. The crude enzyme exhibited generally similar properties (temperature and pH optimum) as the highly purified hydrolase described previously; however, the storage capability and thermal stability is improved when the crude enzyme solution is diafiltrated.

  8. Evaluation report on the development of polymeric material from renewable resource using biocatalyst; Seitai shokubai wo riyoshita saisei kano shigen kara no kobunshi sozai no kaihatsu hyoka hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The project aims to develop a biocatalyst-assisted synthesizing method for efficiently manufacturing sugar containing polymers and polylactic acids which generate less environmental impact. Methods were developed using the ALP-901 originating in actinomycetes for changing esterification-shy isopropylidene glucose into vinyladipic ester and for esterifying arbutin. A study was made of the polymerization of sugar ester monomers, and a polymer with a molecular weight of scores of thousands was obtained. The biodegradability of sugar containing polymers was confirmed. Using an enzyme, a polymer with a molecular weight of 1200 was obtained. Using a lipase derived from psudomonas cepacia, a polylactic acid was obtained from lactide. A high-function polylactic acid was obtained in a reaction between methyl lactate and divinyladipate. In a reaction between butanediol and lactide, several lactic oligomers different in molecular weight were synthesized, which were then brought into reaction with divinylcarboxylic acid in the presence of an enzyme for the production of polymerizable lactic oligomers. Similarly, polymerizable lactic oligomer derivatives were obtained from glucose and lactide. The oligomers and derivatives were brought into polymerization in the presence of a radical polymerization initiator for the production of polymeric gels, respectively. (NEDO)

  9. Metabolome based volatiles profiling in 13 date palm fruit varieties from Egypt via SPME GC-MS and chemometrics.

    Science.gov (United States)

    Khalil, Mohammed N A; Fekry, Mostafa I; Farag, Mohamed A

    2017-02-15

    Dates (Phoenix dactylifera L.) are distributed worldwide as major food complement providing a source of sugars and dietary fiber as well as macro- and micronutrients. Although phytochemical analyses of date fruit non-volatile metabolites have been reported, much less is known about the aroma given off by the fruit, which is critical for dissecting sensory properties and quality traits. Volatile constituents from 13 date varieties grown in Egypt were profiled using SPME-GCMS coupled to multivariate data analysis to explore date fruit aroma composition and investigate potential future uses by food industry. A total of 89 volatiles were identified where lipid-derived volatiles and phenylpropanoid derivatives were the major components of date fruit aroma. Multivariate data analyses revealed that 2,3-butanediol, hexanal, hexanol and cinnamaldehyde contributed the most to classification of different varieties. This study provides the most complete map of volatiles in Egyptian date fruit, with Siwi and Sheshi varieties exhibiting the most distinct aroma among studied date varieties. PMID:27664623

  10. Versatile Biodegradable Poly(ester amides Derived from α-Amino Acids for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Pooneh Karimi

    2010-03-01

    Full Text Available Biodegradable poly(ester amide (PEA biomaterials derived from α-amino acids, diols, and diacids are promising materials for biomedical applications such as tissue engineering and drug delivery because of their optimized properties and susceptibility for either hydrolytic or enzymatic degradation. The objective of this work was to synthesize and characterize biodegradable PEAs based on the α-amino acids L-phenylalanine and L-methionine. Four different PEAs were prepared using 1,4-butanediol, 1,6-hexanediol, and sebacic acid by interfacial polymerization. High molecular weight PEAs with narrow polydispersity indices and excellent film-forming properties were obtained. The incubation of these PEAs in PBS and chymotrypsin indicated that the polymers are biodegradable. Human coronary artery smooth muscle cells were cultured on PEA films for 48 h and the results showed a well-spread morphology. Porous 3D scaffolds fabricated from these PEAs were found to have excellent porosities indicating the utility of these polymers for vascular tissue engineering.

  11. The {gamma} radiolysis at room temperature of liquid deaerated isopropanol; Radiolyse {gamma} a temperature ambiante de l'isopropanol liquide desaere

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-02-01

    The main products formed in the room temperature {gamma} radiolysis of liquid isopropanol, and their respective yields, are: hydrogen 3.8, methane 1.6, acetone 3.4, acetaldehyde 1.1, and pinacol 0.3. These results give a material balance in good agreement with the formula of isopropanol and lead to a value for the yield of decomposition: 5, 3. The absence of butanediol 2.3 shows that the acetaldehyde cannot come from the dismutation of hydroxyethyl radicals. The variations of the hydrogen yield in the neutral medium with the concentration of added electron scavengers may be explained in terms of the model proposed by Freeman and FAYADH which supposes the existence of spurs. The yield of solvated electrons diffusing into the bulk of the solution and also the ratios of rate constants for the reactions of the scavengers with the electrons may likewise be obtained on the basis of this model. Certain effects not foreseen by this model may result from the capture of electrons solvated or not, whose mode of disappearance in pure alcohol remains unknown. One may distinguish a yield of excited molecules of at least 2, of which 80 per cent lead to the production of molecular hydrogen and 20 per cent to that of molecular methane, and an ionization yield of 2. 2. The discussion of the various mechanisms which may lead to the formation of the products indicates that these yields may be higher than the values quoted. (author) [French] Les principaux produits formes a temperature ambiante dans la radiolyse {gamma} de l'isopropanol liquide sont: l'hydrogene, le methane, l'acetone, l'acetaldehyde et le pinacol avec des rendements respectifs de 3,8 - 1,6 - 3,4 - 1,1 - 0,3. Le bilan de masse deduit de ces resultats est en bon accord avec la formule brute de l'isopropanol dont le rendement de decomposition est 5,3. L'absence de butanediol 2,3 montre que l'acetaldehyde ne peut provenir de la reaction de dismutation des radicaux hydroxyethyles. Le

  12. 发酵蒸馏酒基液呈味物质的分析及在饮料调配中应用研究%Analysis of Flavouring Material of Concentrated Foundation Liquid of Fermenting and Distilling Wine and Seasoning Technology in Preparation Processing of the Beverage

    Institute of Scientific and Technical Information of China (English)

    赵金; 李新华

    2014-01-01

    以威士忌液体发酵蒸馏酒基液浓缩液为原料,采用CHCl2萃取浓缩液中的呈味物质,对其呈味物质进行GC-MS分析。结果表明:呈味物质包括69种化合物,其中主要呈味物质为2,3-丁二醇、乙醇、苯乙醇、2,5-己二醇、癸酸乙酯、月桂酸乙酯、3-甲基丁酸和糠醛等36种。在饮料配方中加入该浓缩液,通过调整糖酸比,制作的饮料酸甜可口、风味独特。单因素及正交试验结果表明:在甜味剂添加量为6%,酸味剂添加量为0.03%,香兰素添加量为0.01%的基础上,浓缩液的添加量为0.5%,此时感官风味最好。经GC-MS分析此风味饮料中呈味物质共包括30种化合物,主要成分为香草醛、2,3-丁二醇、乙醇、苯乙醇、乙酸乙酯、癸酸乙酯、糠醛、苯甲醛,此风味饮料保留了19种原浓缩液的风味物质。%Concentrated foundation liquid of fermenting and distilling wine of whisky as the research object. Flavouring materials were extracted by solvent extraction. According to the analysis of GC/MS, 69 components were identified. The main components were Ethyl alcohol,2,3-Butanediol,Phenylethyl Alcohol,2,5-Hexanediol,Decanoic acid,ethyl ester,Dodecanoic acid,ethyl ester,3-methylbutanoic acid,Furfural.etc. a total of 36. adding the concentrate in the beverage, and adjusting the sugar and acid ratio make the sweet and delicious beverage. The single factor and orthogonal experiment results indicated: In sweeteners, adding amount was 6%,citric acid content was 0.03%, vanillin content of 0.01%, on the basis of concentrate adding amount of 0.5%, the sensory flavor is the best. According to the analysis of GC/MS, 30 components were identified in the flavor drink. The main componets were Vanillin,2,3 -Butanediol,Ethyl alcohol,Phenylethyl Alcohol,Ethyl Acetate,Decanoic acid,ethyl ester,Furfural, Benzaldehyde. The specialty drinks retain a concentrate of 19 species of the original flavor.

  13. Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; K.E. Duncan; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; Randy R. Simpson; N.Ravi; D. Nagle

    2005-08-15

    The project had three objectives: (1) to develop microbial strains with improved biosurfactant properties that use cost-effective nutrients, (2) to obtain biosurfactant strains with improved transport properties through sandstones, and (3) to determine the empirical relationship between surfactant concentration and interfacial tension and whether in situ reactions kinetics and biosurfactant concentration meets appropriate engineering design criteria. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns and Berea sandstone cores when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. Even low biosurfactant concentrations (16 mg/l) mobilized substantial amounts of residual hydrocarbon (29%). The bio-surfactant lowered IFT by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. A mathematical model that relates oil recovery to biosurfactant concentration was modified to include the stepwise changes in IFT as biosurfactant concentrations changes. This model adequately predicted the experimentally observed changes in IFT as a function of biosurfactant concentration. Theses data show that lipopeptide biosurfactant systems may be effective in removing hydrocarbon contamination sources in soils and aquifers and for the recovery of entrapped oil from low production oil reservoirs. Diverse microorganisms were screened for biosurfactant production and anaerobic

  14. 棕榈花、叶、茎挥发油成分及抑菌活性研究%Study on chemical components of the essential oils in flower, leaf and stem of Trachycarpus fortunei (Hook) H.Wendl.and their antimicrobial activities

    Institute of Scientific and Technical Information of China (English)

    卫强; 王燕红

    2016-01-01

    采用超临界二氧化碳萃取,应用气相色谱-质谱联用( GC-MS)法鉴定棕榈花、叶、茎挥发油化学成分,并考查其体外抗菌活性。结果显示,共鉴定得到224种化合物。棕榈花挥发油中主要有二十三烷(23.86%)、二十八烷(8.48%)等;棕榈叶挥发油中主要有(Z)-3-己烯-1-醇(15.87%)、正己醇(12.60%)、2,3-丁二醇(10.19%)、3-(1-乙氧乙氧基)-2-甲基丁烷-1,4-二醇(9.63%)、甲苯(9.60%)、2-乙氧基-3-氯丁烷(8.10%)等;棕榈茎挥发油中主要有甲苯(13.80%)、1,1-二乙氧基乙烷(25.77%)、2,3-丁二醇(10.65%)等。棕榈花、叶、茎的环己烷、乙醚萃取挥发油对特定病原菌有特殊抑菌效果,可作为抑菌剂使用。%In order to analyze the chemical components of essential oils in flower , leaf and stem of Trachycarpus for-tunei (Hook.) H.Wendl.and their biological activities , the volatile oils were extracted by supercritical CO 2 extrac-tion and were identified by GC-MS.The antimicrobial activities of the identified volatile oils were inspected in vitro. It was shown that 224 components were identified altogether .In flowers, main constituents of the identified volatile oils were tricosane (23.86%) and octacosane(8.48%).(Z)-3-hexen-1-ol (15.87%), 1-hexanol (12.60%), 2, 3-butanediol (10.19%), 3-(1-ethoxyethoxy)-2-methylbutane-1,4-diol (9.63%), toluene(9.60%) and 2-ethoxy-3-chlorobutane (8.10%) were the main volatile oils in the leaf, and toluene (13.80%), 1,1-diethoxy-ethane (25.77%) and 2,3-butanediol (10.65%) were the majority in stem.The extracted volatile oils from flower , leaf and stem by cyclonexane and aether exhibited special inhibiting activities against some pathogenic bacteria , which in-dicated their potential as bacteriostatic agent .

  15. Organ preservation at low temperature: a physical and biological problem

    Science.gov (United States)

    Aussedat, J.; Boutron, P.; Coquilhat, P.; Descotes, J. L.; Faure, G.; Ferrari, M.; Kay, L.; Mazuer, J.; Monod, P.; Odin, J.; Ray, A.

    1993-02-01

    Before reporting the preliminary results obtained by our group, we first review the main problems to be solved in the preservation of organs at very low temperature, before being transplanted. This cryopreservation is being presently explored in order to increase the preservation tiine of transplants and to contribute to a better control of the donor recipient compatibility. We recall that, for the isolated cells to be preserved at nitrogen liquid temperatures, as now successfully performed at industrial scale, it is necessary to immerse the cells in a solution containing more or less t,oxical additives (so-called cryopro tect ants). Furthermore cooling and warming rates must be specific of each type of cells. We then show that cryo preservation could be extrapolated to whole organs by means of vitrification, the only way to avoid any ice crystallization. This vitrification will be the result of two directions of research, the one on the elaboration of cryoprotective solutions, the least toxic possible, the other on the obtention of high enough and homogeneous cooling and warming rates. After having briefly summarized the state of research on the heart and kidneys of small mammals, we present the first results that we have obtained on perfusion at 4 ^{circ}C and the auto-transplantation of rabbit kidneys, on the toxicity of a new cryoprotectant, 2,3-butanediol, on the heart rate, and on the cooling of experimental models of organs. Avant de présenter les résultats préliminaires obtenus par notre groupe, nous passons d'abord en revue les principaux problèmes à résoudre pour conserver à très basse température des organes en vue de leur transplantation. Cette cryopréservation est une voie de recherche actuellement explorée pour augmenter la durée de conservation des greffons et permettre ainsi de mieux contrôler la compatibilité donneur-receveur. Nous rappelons que la conservation des cellules isolées à la température de l'azote liquide, actuellement

  16. DEVELOPMENT OF MICROORGANISMS WITH IMPROVED TRANSPORT AND BIOSURFACTANT ACTIVITY FOR ENHANCED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; R.M. Knapp; D.P. Nagle, Jr.; Kathleen Duncan; N. Youssef; M.J. Folmsbee; S. Maudgakya

    2003-06-26

    Biosurfactants enhance hydrocarbon biodegradation by increasing apparent aqueous solubility or affecting the association of the cell with poorly soluble hydrocarbon. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. One pore volume of cell-free culture fluid with 900 mg/l of the biosurfactant, 10 mM 2,3-butanediol and 1000 mg/l of partially hydrolyzed polyacrylamide polymer mobilized 82% of the residual hydrocarbon. Consistent with the high residual oil recoveries, we found that the bio-surfactant lowered the interfacial tension (IFT) between oil and water by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. The lipopeptide biosurfactant system may be effective in removing hydrocarbon contamination sources in soils and aquifers and for the recovery of entrapped oil from low production oil reservoirs. Previously, we reported that Proteose peptone was necessary for anaerobic growth and biosurfactant production by B. mojavensis JF-2. The data gathered from crude purification of the growth-enhancing factor in Proteose peptone suggested that it consisted of nucleic acids; however, nucleic acid bases, nucleotides or nucleosides did not replace the requirement for Proteose Peptone. Further studies revealed that salmon sperm DNA, herring sperm DNA, Echerichia coli DNA and synthetic DNA replaced the requirement for Proteose peptone. In addition to DNA, amino acids and nitrate were required for anaerobic growth and vitamins further improved growth. We now have a defined medium that can be used to manipulate growth and biosurfactant

  17. H{sub 2}V{sub 3}O{sub 8} nanobelts as a novel stable electrode material with good reversible redox performance

    Energy Technology Data Exchange (ETDEWEB)

    Mjejri, I.; Etteyeb, N. [Laboratoire de Chimie de la Matière Condensée, Université de Tunis, Institut Préparatoire aux Études d’Ingénieurs (Tunisia); Sediri, F., E-mail: faouzi.sediri@ipeit.rnu.tn [Laboratoire de Chimie de la Matière Condensée, Université de Tunis, Institut Préparatoire aux Études d’Ingénieurs (Tunisia); Faculté des Sciences de Tunis, Université Tunis-Elmanar, 2092 Elmanar, Tunis (Tunisia)

    2014-10-25

    Highlights: • Belt-like nanocrystalline H{sub 2}V{sub 3}O{sub 8} was synthesized hydrothermally. • Reversible redox behavior with doping/dedoping process. • Doping/dedoping is easier for Li{sup +} to Na{sup +} one and to K{sup +} cation. • Energy-related applications such as cathodes in lithium batteries. - Abstract: Belt-like nanocrystalline H{sub 2}V{sub 3}O{sub 8} has been successfully synthesized via a hydrothermal process using vanadium pentoxide as inorganic precursor and 1,4-butanediol as structure-directing template. It is found that the reaction time has a significant effect on the morphology of the product. The as-synthesized H{sub 2}V{sub 3}O{sub 8} nanobelts are up to several of micrometers in length and about 35 nm in average width. The nanobelts show a large BET surface area which favors the electrochemical properties. The optical properties of the as-synthesized H{sub 2}V{sub 3}O{sub 8} nanobelts were investigated by UV–visible absorption and photoluminescence. The band gap was found to be 2.75 eV. Electrochemical measurements have revealed reversible redox behavior with doping/dedoping process corresponding to reversible cation intercalation/deintercalation. This process is easier in propylene carbonate than in aqueous solvent and is easier for the small Li{sup +} to the larger Na{sup +} one and to the largest K{sup +} cation. This has been assigned to a probable presence of different tunnel cavities in the orthorhombic H{sub 2}V{sub 3}O{sub 8} lattice.

  18. Preparation and characterization of poly-(methacrylatoethyl trimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate monolith

    Directory of Open Access Journals (Sweden)

    Eko Malis

    2015-05-01

    Full Text Available A polymer monolithic column, poly-(methacrylatoethyltrimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate or poly-(MATE-co-VBC-co-EDMA was successfully prepared in the current study by one-step thermally initiated in situ polymerization, confined in a steel tubing of 0.5 mm i.d. and 1/16” o.d. The monoliths were prepared from methacrylatoethyltrimethylammonium chloride (MATE and vinylbenzyl chloride (VBC as monomer and ethylene dimethacrylate (EDMA as crosslinker using a binary porogen system of 1-propanol and 1,4-butanediol. The inner wall of steel tubing was pretreated with 3-methacryloxypropyl-trimethoxysilane (MAPS. In order to obtain monolith with adequate column efficiency and low flow resistance, some parameters such as total monomer concentration (%T and crosslinker concentration (%C were optimized. The morphology of this monolith was assessed by scanning electron microscopy (SEM. The properties of the monolithic column, such as permeability, binding capacity, and pore size distribution were also characterized in detail. From the results of the characterization of all monolith variation, monolith with %T 30 %C 50 and %T 35 %C 50 give the best characteristic. These monoliths have high permeability, adequate molecular recognition sites (represented with binding capacity value of over 20 mg/mL, and have over 80% flow through pores in their pore structure contribute to low flow resistance. The resulted monolithic columns have promising potential for dual mode liquid chromatography. MATE may contribute for anion-exchange while VBC may responsible for reversed-phase liquid chromatography.

  19. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    International Nuclear Information System (INIS)

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process

  20. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  1. Polystyrene-divinylbenzene-glycidyl methacrylate stationary phase grafted with poly (amidoamine) dendrimers for ion chromatography.

    Science.gov (United States)

    Guo, Dandan; Lou, Chaoyan; Zhang, Peimin; Zhang, Jiajie; Wang, Nani; Wu, Shuchao; Zhu, Yan

    2016-07-22

    In this work, a novel ion exchange stationary phase based on different generations of poly (amidoamine) dendrimers (PAMAM) was developed for the determination of inorganic anions and carbohydrates. Synthesis of the PAMAM was carried out with the polymerization reaction of ethylenediamine and methyl acrylate. The synthesized PAMAM was then grafted to the polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) to form PAMAM-based beads. These beads were finally modified with 1,4-butanediol diglycidyl ether (BDDE) to generate the anion exchanger, which were characterized by scanning electron microscopy (SEM), brunauer-emmett-teller (BET), fourier transform infrared spectroscopy (FTIR), and elemental analysis. Elemental analysis, breakthrough curves and capacity factors showed that more epoxy groups and higher PAMAM generations in stationary phase could result in higher anion exchange capacity. The efficiency, durability and stability of the proposed anion exchanger were investigated by using six inorganic anions (fluoride, chloride, nitrite, bromide, nitrate and sulfate) and four carbohydrates (trehalose, glucose, maltotriose and galacturonic acid) as analytes, respectively. The reliability of the proposed ion chromatographic stationary phase was demonstrated by determining the content of galacturonic acid in polysaccharides from Poria cocos and Atractylodes macrocephala. The relative standard deviations of retention time, peak height, and peak area for galacturonic acid were 0.39%, 1.22%, and 2.02%, respectively. The spiked recoveries were in the range of 88.29%-100.51% for plant polysaccharides. Due to the good structural homogeneity, intense internal porosity, biological compatibility and high density of active groups in PAMAM, this grafted stationary phase showed good ion-exchange characteristics, especially in biological charged molecules.

  2. Anion exchangers with branched functional ion exchange layers of different hydrophilicity for ion chromatography.

    Science.gov (United States)

    Shchukina, O I; Zatirakha, A V; Smolenkov, A D; Nesterenko, P N; Shpigun, O A

    2015-08-21

    Novel polystyrene-divinylbenzene (PS-DVB) based anion exchangers differing from each other in the structure of the branched functional ion exchange layer are prepared to investigate the role of linker and functional site on ion exchange selectivity. The proposed method of synthesis includes the obtaining of aminated PS-DVB particles by means of their acylation with following reductive amination with methylamine. Further modification of the obtained secondary aminogroups is provided by the alkylation with either 1,4-butanediol diglycidyl ether (1,4-BDDGE) or resorcinol diglycidyl ether (RDGE), which form the linkers of different hydrophobicity, and amination of terminal epoxide rings with trimethylamine (TMA), dimethylethanolamine (DMEA), methyldiethanolamine (MDEA) or triethanolamine (TEA). The variation of the structure and hydrophobicity of the linker and terminal quaternary ammonium sites in the functional layer allows the alteration of selectivity and separation efficiency of the obtained adsorbents. The ion exchange selectivity and separation efficiency of the anion exchangers are evaluated using the model mixtures of anions (F(-), HCOO(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) in potassium hydroxide eluents. The adsorbents show the decrease of selectivity with increasing the hydrophilicity of the terminal functional site. The anion exchangers having more flexible and hydrophilic 1,4-BDDGE linker provide smaller separation factors for most of the analytes as compared with RDGE-containing adsorbents with the same terminal ion exchange sites, but are characterized with higher column efficiencies and better peak symmetry for polarizable anions. In case of 1,4-BDDGE-modified anion exchangers of the particle size of 3.3μm functionalized with DMEA and MDEA the calculated values of column efficiencies for polarizable NO3(-) and Br(-) are up to 49,000 and 53,000N/m, respectively, which is almost twice higher than the values obtained for the RDGE

  3. 复合二元酸改性环氧树脂的制备工艺研究%Study on Preparation Technology of Dibasic Acid Modified Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    马群锋; 朱蓓蓓; 周生启

    2014-01-01

    用C36二聚酸、癸二酸与1,4-丁二醇二缩水甘油醚和双酚A型环氧树脂进行扩链反应,制备柔韧性环氧树脂预聚体。考察了配方组成、反应温度和催化剂等因素对羧基转化率的影响。结果表明,对于所给配方,当催化剂用量为0.1%,140℃下反应2 h,反应基本完全。另外,以柔韧性环氧树脂预聚体为基体树脂制备的固化物拉伸强度达到12.0 MPa,断裂伸长率为85%。%We process extender chain reaction with C36 dimer acid, sebacic acid, 1,4-butanediol diglycidyl and bisphenol A type epoxy resin, and produce flexible epoxy resin prepolymers. We investigate the influence of carboxyl conversion rate from formula composition, reaction temperature and catalyst and other factors. The results show that, for given formula, when the dosage of catalyst is 0.1%,it reacts 2h under 140 ℃, and the re-action is substantially complete. In addition, the flexibility of a cured epoxy resin prepolymer matrix resin composition prepared by a tensile strength of 12.0 MPa, elongation at break of 85%.

  4. Curing behaviors and properties of an extrinsic toughened epoxy/anhydride system and an intrinsic toughened epoxy/anhydride system

    International Nuclear Information System (INIS)

    Highlights: ► Two curing systems (ETRS and ITRS) with similar chemical composite were prepared. ► The curing kinetics of the ETRS and the novel ITRS were comparatively studied. ► Crosslinking density can affect the kinetic schemes of the two curing systems. ► Their mechanical properties and thermal stabilities were also comparatively studied. ► Crosslinking density may play an influential role in mechanical properties. - Abstract: The curing kinetics of an extrinsic toughened epoxy (mixture of diglycidyl ether of bisphenol-A and 1,4-butanediol epoxy resin, DGEBA/DGEBD) and an intrinsic toughened epoxy (ethoxylated bisphenol-A epoxy resin with two oxyethylene units, DGEBAEO-2) using hexahydrophthalic anhydride (HHPA) as curing agent and tris-(dimethylaminomethyl) phenol (DMP-30) as accelerator were comparatively studied by non-isothermal DSC with a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin. The dynamic mechanical properties and thermal stabilities of the cured materials were investigated by DMTA and TGA, respectively. The results showed that Šesták–Berggren model can generally simulate well the reaction rates of these two systems. The activation energy of DGEBA/DGEBD/HHPA/DMP-30 at high fractional conversion changed much higher than that of DGEBAEO-2/HHPA/DMP-30, indicating the increased steric hindrance mainly affected the reaction kinetic scheme of DGEBA/DGEBD/HHPA/DMP-30. The Tg and storage moduli of cured DGEBAEO-2/HHPA/DMP-30 were lower than those of cured DGEBA/DGEBD/HHPA/DMP-30 according to DMTA while TGA showed that the thermal stabilities of these two cured systems were similar

  5. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    Directory of Open Access Journals (Sweden)

    Almeida João R M

    2012-07-01

    Full Text Available Abstract The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a “waste-stream” instead of a valuable “coproduct”. The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  6. Curing behaviors and properties of an extrinsic toughened epoxy/anhydride system and an intrinsic toughened epoxy/anhydride system

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Mengjin; Liu, Jialin; Li, Xiangyuan [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Cheng, Jue, E-mail: chengjue@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Junying, E-mail: zjybuct@gmail.com [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-02-20

    Highlights: ► Two curing systems (ETRS and ITRS) with similar chemical composite were prepared. ► The curing kinetics of the ETRS and the novel ITRS were comparatively studied. ► Crosslinking density can affect the kinetic schemes of the two curing systems. ► Their mechanical properties and thermal stabilities were also comparatively studied. ► Crosslinking density may play an influential role in mechanical properties. - Abstract: The curing kinetics of an extrinsic toughened epoxy (mixture of diglycidyl ether of bisphenol-A and 1,4-butanediol epoxy resin, DGEBA/DGEBD) and an intrinsic toughened epoxy (ethoxylated bisphenol-A epoxy resin with two oxyethylene units, DGEBAEO-2) using hexahydrophthalic anhydride (HHPA) as curing agent and tris-(dimethylaminomethyl) phenol (DMP-30) as accelerator were comparatively studied by non-isothermal DSC with a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin. The dynamic mechanical properties and thermal stabilities of the cured materials were investigated by DMTA and TGA, respectively. The results showed that Šesták–Berggren model can generally simulate well the reaction rates of these two systems. The activation energy of DGEBA/DGEBD/HHPA/DMP-30 at high fractional conversion changed much higher than that of DGEBAEO-2/HHPA/DMP-30, indicating the increased steric hindrance mainly affected the reaction kinetic scheme of DGEBA/DGEBD/HHPA/DMP-30. The T{sub g} and storage moduli of cured DGEBAEO-2/HHPA/DMP-30 were lower than those of cured DGEBA/DGEBD/HHPA/DMP-30 according to DMTA while TGA showed that the thermal stabilities of these two cured systems were similar.

  7. The Relations between Flavoring Components and Sensory Quality of Market-sold Grape Wine%市售葡萄酒风味物质与感官品质的关系分析

    Institute of Scientific and Technical Information of China (English)

    魏晓华

    2015-01-01

    In this study, esters, alcohols and organic acids of eight market-sold wine products were analyzed by GC. Meanwhile, those wine products were scored by sensory evaluation. It was found that, the varieties and content of flavoring components of white wine were lower than red wine, and wine with high sensory evaluation score had higher content of ethyl acetate and ethyl lactate. Active-amyl alcohol had key influ-ence on wine flavor. In addition, relativity analysis suggested that wine sensory score had positive correlations with the content of n-butanol, acetic acid, heptylic acid, 2,3-butanediol andβ-phenethylamine.%采用气相色谱对8种市售葡萄酒中酯类、醇类与有机酸风味物质进行分析,同时对葡萄酒进行感官品评和评分.结果表明,白葡萄酒中风味物质种类及含量均低于红葡萄酒;感官品评得分较高的葡萄酒中乙酸乙酯、乳酸乙酯含量较高.活性戊醇是对葡萄酒的风味起着关键影响的风味物质.此外,通过相关性分析发现正丁醇、乙酸、庚酸、2,3-丁二醇、β-苯乙醇与葡萄酒感官品评得分呈正相关.

  8. Thermal conductivity of the cryoprotective cocktail DP6 in cryogenic temperatures, in the presence and absence of synthetic ice modulators.

    Science.gov (United States)

    Ehrlich, Lili E; Malen, Jonathan A; Rabin, Yoed

    2016-10-01

    The thermal conductivity of the cryoprotective agent (CPA) cocktail DP6 in combination with synthetic ice modulators (SIMs) is measured in this study, using a transient hot-wire method. DP6 is a mixture of 3 M dimethyl sulfoxide (DMSO) and 3 M propylene glycol, which received significant attention in the cryobiology community in recent years. Tested SIMs include 6% 1,3Cyclohexanediol, 6% 2,3Butanediol, and 12% PEG400 (percentage by volume). This study integrates the scanning cryomacroscope for visual verification of crystallization and vitrification events. It is demonstrated that the thermal conductivity of the vitrifying CPA cocktail decreases monotonically with the decreasing temperature down to -180 °C. By contrast, the thermal conductivity of the crystalline material increases with decreasing temperature in the same temperature range. Results of this study demonstrate that the thermal conductivity may vary by three fold between the amorphous and crystalline phases of DP6 below the glass transition temperature of DP6 (Tg = -119 °C). The selected SIMs demonstrate the ability to inhibit crystallization in DP6, even at subcritical cooling rates. An additional ice suppression capability is observed by the Euro-Collins as a vehicle solution, disproportionate to its volume ratio in the cocktail. The implication of the observed thermal conductivity differences between the amorphous and crystalline phases of the same cocktail on cryopreservation simulations is significant in some cases and must be taken into account in thermal analyses of cryopreservation protocols.

  9. Induction, purification and characterization of a novel manganese peroxidase from Irpex lacteus CD2 and its application in the decolorization of different types of dye.

    Directory of Open Access Journals (Sweden)

    Xing Qin

    Full Text Available Manganese peroxidase (MnP is the one of the important ligninolytic enzymes produced by lignin-degrading fungi which has the great application value in the field of environmental biotechnology. Searching for new MnP with stronger tolerance to metal ions and organic solvents is important for the maximization of potential of MnP in the biodegradation of recalcitrant xenobiotics. In this study, it was found that oxalic acid, veratryl alcohol and 2,6-Dimehoxyphenol could stimulate the synthesis of MnP in the white-rot fungus Irpex lacteus CD2. A novel manganese peroxidase named as CD2-MnP was purified and characterized from this fungus. CD2-MnP had a strong capability for tolerating different metal ions such as Ca2+, Cd2+, Co2+, Mg2+, Ni2+ and Zn2+ as well as organic solvents such as methanol, ethanol, DMSO, ethylene glycol, isopropyl alcohol, butanediol and glycerin. The different types of dyes including the azo dye (Remazol Brilliant Violet 5R, Direct Red 5B, anthraquinone dye (Remazol Brilliant Blue R, indigo dye (Indigo Carmine and triphenylmethane dye (Methyl Green as well as simulated textile wastewater could be efficiently decolorized by CD2-MnP. CD2-MnP also had a strong ability of decolorizing different dyes with the coexistence of metal ions and organic solvents. In summary, CD2-MnP from Irpex lacteus CD2 could effectively degrade a broad range of synthetic dyes and exhibit a great potential for environmental biotechnology.

  10. Aroma compounds generation in citrate metabolism of Enterococcus faecium: Genetic characterization of type I citrate gene cluster.

    Science.gov (United States)

    Martino, Gabriela P; Quintana, Ingrid M; Espariz, Martín; Blancato, Victor S; Magni, Christian

    2016-02-01

    Enterococcus is one of the most controversial genera belonging to Lactic Acid Bacteria. Research involving this microorganism reflects its dual behavior as regards its safety. Although it has also been associated to nosocomial infections, natural occurrence of Enterococcus faecium in food contributes to the final quality of cheese. This bacterium is capable of fermenting citrate, which is metabolized to pyruvate and finally derives in the production of the aroma compounds diacetyl, acetoin and 2,3 butanediol. Citrate metabolism was studied in E. faecium but no data about genes related to these pathways have been described. A bioinformatic approach allowed us to differentiate cit(-) (no citrate metabolism genes) from cit(+) strains in E. faecium. Furthermore, we could classify them according to genes encoding for the transcriptional regulator, the oxaloacetate decarboxylase and the citrate transporter. Thus we defined type I organization having CitI regulator (DeoR family), CitM cytoplasmic soluble oxaloacetate decarboxylase (Malic Enzyme family) and CitP citrate transporter (2-hydroxy-carboxylate transporter family) and type II organization with CitO regulator (GntR family), OAD membrane oxaloacetate decarboxylase complex (Na(+)-transport decarboxylase enzyme family) and CitH citrate transporter (CitMHS family). We isolated and identified 17 E. faecium strains from regional cheeses. PCR analyses allowed us to classify them as cit(-) or cit(+). Within the latter classification we could differentiate type I but no type II organization. Remarkably, we came upon E. faecium GM75 strain which carries the insertion sequence IS256, involved in adaptative and evolution processes of bacteria related to Staphylococcus and Enterococcus genera. In this work we describe the differential behavior in citrate transport, metabolism and aroma generation of three strains and we present results that link citrate metabolism and genetic organizations in E. faecium for the first time.

  11. Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam

    Directory of Open Access Journals (Sweden)

    Pan Xuejun

    2013-01-01

    Full Text Available Abstract Background Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved from the cell wall in pretreatment or chemical pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment methods for woody biomass for cellulosic ethanol production, and kraft process is a dominant chemical pulping method in paper industry. In the present research, the lignins from organosolv pretreatment and kraft pulping were evaluated to replace polyol for producing rigid polyurethane foams (RPFs. Results Petroleum-based polyol was replaced with hardwood ethanol organosolv lignin (HEL or hardwood kraft lignin (HKL from 25% to 70% (molar percentage in preparing rigid polyurethane foam. The prepared foams contained 12-36% (w/w HEL or 9-28% (w/w HKL. The density, compressive strength, and cellular structure of the prepared foams were investigated and compared. Chain extenders were used to improve the properties of the RPFs. Conclusions It was found that lignin was chemically crosslinked not just physically trapped in the rigid polyurethane foams. The lignin-containing foams had comparable structure and strength up to 25-30% (w/w HEL or 19-23% (w/w HKL addition. The results indicated that HEL performed much better in RPFs and could replace more polyol at the same strength than HKL because the former had a better miscibility with the polyol than the latter. Chain extender such as butanediol could improve the strength of lignin-containing RPFs.

  12. Transcriptional responses to sucrose mimic the plant-associated life style of the plant growth promoting endophyte Enterobacter sp. 638.

    Directory of Open Access Journals (Sweden)

    Safiyh Taghavi

    Full Text Available Growth in sucrose medium was previously found to trigger the expression of functions involved in the plant associated life style of the endophytic bacterium Enterobacter sp. 638. Therefore, comparative transcriptome analysis between cultures grown in sucrose or lactate medium was used to gain insights in the expression levels of bacterial functions involved in the endophytic life style of strain 638. Growth on sucrose as a carbon source resulted in major changes in cell physiology, including a shift from a planktonic life style to the formation of bacterial aggregates. This shift was accompanied by a decrease in transcription of genes involved in motility (e.g., flagella biosynthesis and an increase in the transcription of genes involved in colonization, adhesion and biofilm formation. The transcription levels of functions previously suggested as being involved in endophytic behavior and functions responsible for plant growth promoting properties, including the synthesis of indole-acetic acid, acetoin and 2,3-butanediol, also increased significantly for cultures grown in sucrose medium. Interestingly, despite an abundance of essential nutrients transcription levels of functions related to uptake and processing of nitrogen and iron became increased for cultures grown on sucrose as sole carbon source. Transcriptome data were also used to analyze putative regulatory relationships. In addition to the small RNA csrABCD regulon, which seems to play a role in the physiological adaptation and possibly the shift between free-living and plant-associated endophytic life style of Enterobacter sp. 638, our results also pointed to the involvement of rcsAB in controlling responses by Enterobacter sp. 638 to a plant-associated life style. Targeted mutagenesis was used to confirm this role and showed that compared to wild-type Enterobacter sp. 638 a ΔrcsB mutant was affected in its plant growth promoting ability.

  13. Delicate balance of hydrogen bonding forces in D-threoninol.

    Science.gov (United States)

    Vaquero-Vara, Vanesa; Zhang, Di; Dian, Brian C; Pratt, David W; Zwier, Timothy S

    2014-09-01

    The seven most stable conformers of D-threoninol (2(S)-amino-1,3(S)-butanediol), a template used for the synthesis of artificial nucleic acids, have been identified and characterized from their pure rotational transitions in the gas phase using chirped-pulse Fourier transform microwave spectroscopy. D-Threoninol is a close analogue of glycerol, differing by substitution of an NH2 group for OH on the C(β) carbon and by the presence of a terminal CH3 group that breaks the symmetry of the carbon framework. Of the seven observed structures, two are H-bonded cycles containing three H-bonds that differ in the direction of the H-bonds in the cycle. The other five are H-bonded chains containing OH···NH···OH H-bonds with different directions along the carbon framework and different dihedral angles along the chain. The two structural types (cycles and chains of H-bonds) are in surprisingly close energetic proximity. Comparison of the rotational constants with the calculated structures at the MP2/6-311++G(d,p) level of theory reveals systematic changes in the H-bond distances that reflect NH2 as a better H-bond acceptor and poorer donor, shrinking the H-bond distances by ∼0.2 Å in the former case and lengthening them by a corresponding amount in the latter. Thus revealed is the subtle effect of asymmetric substitution on the energy landscape of a simple molecule, likely to be important in living systems.

  14. Metabolic characterization of Palatinate German white wines according to sensory attributes, varieties, and vintages using NMR spectroscopy and multivariate data analyses

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Kashif; Maltese, Federica [Leiden University, Division of Pharmacognosy, Section Metabolomics, Institute of Biology (Netherlands); Toepfer, Reinhard [Institute for Grapevine Breeding Geilweilerhof, Julius Kuehn Institute (JKI), Federal Research Centre for Cultivated Plants (Germany); Choi, Young Hae, E-mail: y.choi@chem.leidenuniv.nl; Verpoorte, Robert [Leiden University, Division of Pharmacognosy, Section Metabolomics, Institute of Biology (Netherlands)

    2011-04-15

    {sup 1}H NMR (nuclear magnetic resonance spectroscopy) has been used for metabolomic analysis of 'Riesling' and 'Mueller-Thurgau' white wines from the German Palatinate region. Diverse two-dimensional NMR techniques have been applied for the identification of metabolites, including phenolics. It is shown that sensory analysis correlates with NMR-based metabolic profiles of wine. {sup 1}H NMR data in combination with multivariate data analysis methods, like principal component analysis (PCA), partial least squares projections to latent structures (PLS), and bidirectional orthogonal projections to latent structures (O2PLS) analysis, were employed in an attempt to identify the metabolites responsible for the taste of wine, using a non-targeted approach. The high quality wines were characterized by elevated levels of compounds like proline, 2,3-butanediol, malate, quercetin, and catechin. Characterization of wine based on type and vintage was also done using orthogonal projections to latent structures (OPLS) analysis. 'Riesling' wines were characterized by higher levels of catechin, caftarate, valine, proline, malate, and citrate whereas compounds like quercetin, resveratrol, gallate, leucine, threonine, succinate, and lactate, were found discriminating for 'Mueller-Thurgau'. The wines from 2006 vintage were dominated by leucine, phenylalanine, citrate, malate, and phenolics, while valine, proline, alanine, and succinate were predominantly present in the 2007 vintage. Based on these results, it can be postulated the NMR-based metabolomics offers an easy and comprehensive analysis of wine and in combination with multivariate data analyses can be used to investigate the source of the wines and to predict certain sensory aspects of wine.

  15. Exposure-response of 1,2:3,4-diepoxybutane-specific N-terminal valine adducts in mice and rats after inhalation exposure to 1,3-butadiene.

    Science.gov (United States)

    Georgieva, Nadia I; Boysen, Gunnar; Bordeerat, Narisa; Walker, Vernon E; Swenberg, James A

    2010-06-01

    1,3-Butadiene (BD) is a known rodent and human carcinogen that is metabolized mainly by P450 2E1 to three epoxides, 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol. The individual epoxides vary up to 200-fold in their mutagenic potency, with DEB being the most mutagenic metabolite. It is important to understand the internal formation of the individual epoxides to assign the relative risk for each metabolite and to understand the molecular mechanisms responsible for extensive species differences in carcinogenicity. This study presents a comprehensive exposure-response for the formation of the DEB-specific N,N-(2,3-dihydroxy-1,4-butadiyl)valine (pyr-Val) in mice and rats. Using nano-ultra high pressure liquid chromatography-tandem-mass spectrometry allowed analysis of pyr-Val in mice and rats exposed to BD as low as 0.1 and 0.5 ppm BD, respectively, and demonstrated significant differences in the amounts and exposure-response of pyr-Val formation. Mice formed 10- to 60-fold more pyr-Val compared to rats at similar exposures. The formation of pyr-Val increased with exposures, and the formation was most efficient with regard to formation per parts per million BD at low exposures. While formation at higher exposures appeared linear in mice, in rats formation saturated at exposures > or = 200 ppm for 10 days. In rats, amounts of pyr-Val were lower after 20 days than after 10 days of exposure, suggesting that the lifespan of rat erythrocytes may be shortened following exposure to BD. This research supports the hypothesis that the lower susceptibility of rats to BD-induced carcinogenesis results from greatly reduced formation of DEB following exposure to BD.

  16. Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks.

    Science.gov (United States)

    Chen, Lei; Huang, Xiaojia

    2016-04-15

    In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012-0.23 μg/L and 0.039-0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9-116%, and the RSDs were below 10% in the all cases.

  17. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

    Science.gov (United States)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. PMID:25491999

  18. Induction, purification and characterization of a novel manganese peroxidase from Irpex lacteus CD2 and its application in the decolorization of different types of dye.

    Science.gov (United States)

    Qin, Xing; Zhang, Jie; Zhang, Xiaoyu; Yang, Yang

    2014-01-01

    Manganese peroxidase (MnP) is the one of the important ligninolytic enzymes produced by lignin-degrading fungi which has the great application value in the field of environmental biotechnology. Searching for new MnP with stronger tolerance to metal ions and organic solvents is important for the maximization of potential of MnP in the biodegradation of recalcitrant xenobiotics. In this study, it was found that oxalic acid, veratryl alcohol and 2,6-Dimehoxyphenol could stimulate the synthesis of MnP in the white-rot fungus Irpex lacteus CD2. A novel manganese peroxidase named as CD2-MnP was purified and characterized from this fungus. CD2-MnP had a strong capability for tolerating different metal ions such as Ca2+, Cd2+, Co2+, Mg2+, Ni2+ and Zn2+ as well as organic solvents such as methanol, ethanol, DMSO, ethylene glycol, isopropyl alcohol, butanediol and glycerin. The different types of dyes including the azo dye (Remazol Brilliant Violet 5R, Direct Red 5B), anthraquinone dye (Remazol Brilliant Blue R), indigo dye (Indigo Carmine) and triphenylmethane dye (Methyl Green) as well as simulated textile wastewater could be efficiently decolorized by CD2-MnP. CD2-MnP also had a strong ability of decolorizing different dyes with the coexistence of metal ions and organic solvents. In summary, CD2-MnP from Irpex lacteus CD2 could effectively degrade a broad range of synthetic dyes and exhibit a great potential for environmental biotechnology. PMID:25412169

  19. 八月瓜果实香气的GC-MS分析%Analysis of aromatic compositions in Akebia trifoliata fruit by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴莹; 张百忍

    2012-01-01

    利用溶剂萃取法提取香气成分,采用气质联用技术,对八月瓜果实的香气成分进行了气质联用检测分析,应用TIC峰面积归一法测定各成分的相对含量.结果表明:从八月瓜果实中检出46种化学成分,鉴定出42种香气成分,占总香气成分含量的94.2%.其中相对含量较高香气成分有:乙酸、5-羟甲基-2-呋喃甲醛、1,3-二羟基丙酮、1-羟基丙酮、异丁醇、2,3-二氢-3,5-二羟基-6-甲基-4(H)吡喃-4-酮、乙酸己酯、2,3-丁二醇、苯乙醇、乙酸乙酯等.%The aromatic compositions in Akebia trifoliate fruit was extracted by solvent extraction and analyzed by GC-MS. The relative contents were determined by area normalization. The results showed that 46 kinds of aromatic compositions were separated and 42 kinds were identified, 94.2% of total content in Akebia trifoliate fruit. The high relative concentration of aromatic compositions were acetic acid, 5-(hydroxymethyl)-2-Furancarbox-aldehyde, 1,3-dihydroxy-2-Propanone, 1-hydroxy-2-Propanone,isobutanol, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-Pyran-4-one, acetic acid hexyl ester, 2,3-butanediol, phenylethyl alcohol, ethyl acetate.

  20. Biological and physicochemical properties of carbon-graphite fibre-reinforced polymers intended for implant suprastructures.

    Science.gov (United States)

    Segerström, Susanna; Sandborgh-Englund, Gunilla; Ruyter, Eystein I

    2011-06-01

    The aim of this study was to determine water sorption, water solubility, dimensional change caused by water storage, residual monomers, and possible cytotoxic effects of heat-polymerized carbon-graphite fibre-reinforced composites with different fibre loadings based on methyl methacrylate/poly(methyl methacrylate) (MMA/PMMA) and the copolymer poly (vinyl chloride-co-vinyl acetate). Two different resin systems were used. Resin A contained ethylene glycol dimethacrylate (EGDMA) and 1,4-butanediol dimethacrylate (1,4-BDMA); the cross-linker in Resin B was diethylene glycol dimethacrylate (DEGDMA). The resin mixtures were reinforced with 24, 36 and 47 wt% surface-treated carbon-graphite fibres. In addition, polymer B was reinforced with 58 wt% fibres. Water sorption was equal to or below 3.34±1.18 wt%, except for the 58 wt% fibre loading of polymer B (5.27±1.22 wt%). Water solubility was below 0.36±0.015 wt%, except for polymer B with 47 and 58 wt% fibres. For all composites, the volumetric increase was below 0.01±0.005 vol%. Residual MMA monomer was equal to or below 0.68±0.05 wt% for the fibre composites. The filter diffusion test and the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay demonstrated no cytotoxicity for the carbon-graphite fibre-reinforced composites, and residual cross-linking agents and vinyl chloride were not detectable by high-performance liquid chromatography (HPLC) analysis.

  1. Effect of cationic side-chains on intracellular delivery and cytotoxicity of pH sensitive polymer-doxorubicin nanocarriers

    Science.gov (United States)

    Fang, Chen; Kievit, Forrest M.; Cho, Yong-Chan; Mok, Hyejung; Press, Oliver W.; Zhang, Miqin

    2012-10-01

    Fine-tuning the design of polymer-doxorubicin conjugates permits optimization of an efficient nanocarrier to greatly increase intracellular uptake and cytotoxicity. Here, we report synthesis of a family of self-assembled polymer-doxorubicin nanoparticles and an evaluation of the effects of various types of side-chains on intracellular uptake and cytotoxicity of the nanocarriers for lymphoma cells. Monomers with three different cationic side-chains (CA) and pKa's, i.e., a guanidinium group (Ag), an imidazole group (Im), and a tertiary amine group (Dm), were comparatively investigated. The cationic monomer, poly(ethylene glycol) (PEG), and doxorubicin (Dox) were reacted with 1,4-(butanediol) diacrylate (BUDA) to prepare a poly(β-amino ester) (PBAE) polymer via Michael addition. All three polymer-Dox conjugates spontaneously formed nanoparticles (NP) through hydrophobic interactions between doxorubicin in aqueous solution, resulting in NP-Im/Dox, NP-Ag/Dox, and NP-Dm/Dox, with hydrodynamic sizes below 80 nm. Doxorubicin was linked to all 3 types of NPs with a hydrazone bond to assure selective release of doxorubicin only at acidic pH, as it occurs in the tumor microenvironment. Both NP-Im/Dox and NP-Ag/Dox exhibited much higher intracellular uptake by Ramos cells (Burkitt's lymphoma) than NP-Dm/Dox, suggesting that the type of side chain in the NPs determines the extent of intracellular uptake. As a result, NP-Im/Dox and NP-Ag/Dox showed cytotoxicity that was comparable to free Dox in vitro. Our findings suggest that the nature of surface cationic group on nanocarriers may profoundly influence their intracellular trafficking and resulting therapeutic efficacy. Thus, it is a crucial factor to be considered in the design of novel carriers for intracellular drug delivery.

  2. Metabolic characterization of Palatinate German white wines according to sensory attributes, varieties, and vintages using NMR spectroscopy and multivariate data analyses

    International Nuclear Information System (INIS)

    1H NMR (nuclear magnetic resonance spectroscopy) has been used for metabolomic analysis of ‘Riesling’ and ‘Mueller-Thurgau’ white wines from the German Palatinate region. Diverse two-dimensional NMR techniques have been applied for the identification of metabolites, including phenolics. It is shown that sensory analysis correlates with NMR-based metabolic profiles of wine. 1H NMR data in combination with multivariate data analysis methods, like principal component analysis (PCA), partial least squares projections to latent structures (PLS), and bidirectional orthogonal projections to latent structures (O2PLS) analysis, were employed in an attempt to identify the metabolites responsible for the taste of wine, using a non-targeted approach. The high quality wines were characterized by elevated levels of compounds like proline, 2,3-butanediol, malate, quercetin, and catechin. Characterization of wine based on type and vintage was also done using orthogonal projections to latent structures (OPLS) analysis. ‘Riesling’ wines were characterized by higher levels of catechin, caftarate, valine, proline, malate, and citrate whereas compounds like quercetin, resveratrol, gallate, leucine, threonine, succinate, and lactate, were found discriminating for ‘Mueller-Thurgau’. The wines from 2006 vintage were dominated by leucine, phenylalanine, citrate, malate, and phenolics, while valine, proline, alanine, and succinate were predominantly present in the 2007 vintage. Based on these results, it can be postulated the NMR-based metabolomics offers an easy and comprehensive analysis of wine and in combination with multivariate data analyses can be used to investigate the source of the wines and to predict certain sensory aspects of wine.

  3. Selecting ethanol as a model organic solvent in radiation chemistry--3. Radiolysis of glycyrrhetinic acid (GL)-ethanol system and structure modification of GL by γ radiation method

    International Nuclear Information System (INIS)

    CH3CHOH, H·, esolv- are the main active radicals in the ethanol system irradiated by γ-ray without the presence of oxygen. In this study, GL ethanolic solution saturated with nitrogen was γ-irradiated, the radiolytic products were isolated by HPLC and the molecular structure was determined with UV, IR, MS spectra and elementary analysis methods. In this system GL reacts with H· and CH3CHOH radicals. CH3CHOH adds to the C-C double bond of GL, then the formed radicals disproportionate to the final products RP1 (olean 29-oic acid,3-hydroxy-11-oxo-12-ethoxyl-13-hydro-,(3β, 20β)-) and RP3. H· reacts with GL in the similar way. The rate constant of H· reacting with GL was obtained as kGL+H·=2.0x1010 dm3 mol-1 s-1. The rate constant of CH3CHOH reacting with GL was calculated as result of (1.2±0.1)x104 dm3 mol-1 s-1 by using steady state method and by using the numerical quadrature method with computer. G(-GL), G(H2 ), G(2,3-butanediol), G(CH3CHO) and G values of the radiolytic products of ethanolic solution with different GL concentration were measured. A material balance was obtained. Results show that the active site of a GL molecule is the C-C double bond. The radiation chemistry technique can be used to modify the structure of glycyrrhetinic acid

  4. Synthesis of thermoplastic poly(ester-olefin elastomers

    Directory of Open Access Journals (Sweden)

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  5. Effect of Polycarbonate Content on the Phase Separation and Damping Properties of PUE Based on Mixed Segments%PCDL含量对混和软段的PUE相分离和阻尼性能的影响

    Institute of Scientific and Technical Information of China (English)

    王丙寅; 黄光速

    2012-01-01

    Polyurethane elastomers were synthesized using Toluene Diisocyanate (TDI) and 1, 4-butanediol (BDO) as hard segments and mixed macrodiols derived from polycarbonate diol and polypropylene diol as soft segments by prepolymer method. The effect of polycarbonate content on the phase separation and damping properties of polyurethane elastomers was investigated by DSC, FT-IR and DMA. The results indicated that the PUE phase separation and the fraction of hydrogen bonded carbonyl decreased with PCDL content increasing. And then, the modulus of polyurethanes decreased. Compared with the PUE with one component soft segments, the polyurethane elastomers with mixed soft segments displayed relatively better damping properties.%以甲苯二异氰酸酯( TDI)、1,4-丁二醇(BDO)为硬段,聚碳酸酯二醇(PCDL)和聚醚二醇(PPG)混合物为软段,采用预聚体法制备了不同软段组成的聚氨酯弹性体(PUE).采用DSC、FT-IR和DMA等分析手段研究了PCDL含量对PUE的微相分离程度和阻尼性能的影响.结果表明,随着软段中PCDL含量的增加,PUE中氨酯羰基的氢键化程度减小,相分离程度减小,而且PUE的储能模量随着PCDL含量的增加而减小;与单一组分软段的PUE相比较,混合软段的PUE具有相对较好的阻尼性能.

  6. Synthesis and Application of Starch Grafted with Polyurethane Prepolymer%聚氨酯接枝淀粉的合成及应用

    Institute of Scientific and Technical Information of China (English)

    陈夫山; 赵华; 宋晓明

    2011-01-01

    Polyurethane-based grafted starch is a new type of surface sizing agent in recent years. In this paper, polyurethane prepolymer was used as a special water-resisant monomer, polyurethane-based grafted starch agent with good performance was synthesized. The better synthesis conditions of prepolymer were as follows; The amount of toluene di-isocyanate is 15% of 1,4-butanediol, the temperature is 80t. The optimal synthesis conditions of the sizing agent were as follows; the amount of prepolymer is 10% (on starch) , the weight ratio of monomer to starch is 2-1, the weight ratio of styene to butyl acrylate is 1.5:1.%聚氨酯型接枝淀粉表面施胶剂是近年开发的新型表面施胶剂。本研究以聚氨酯预聚体作为抗水性单体合成了性能优良的聚氨酯型接枝淀粉表面施胶剂。聚氨酯预聚体的较佳合成条件为:甲苯二异氰酸酯用量为1,4-丁二醇的15%,反应温度为80℃;施胶剂的较佳合成条件为:预聚体用量为淀粉的10%,单体与淀粉的质量比为2∶1,苯乙烯与丙烯酸丁酯的质量比为1.5∶1。

  7. UV 固化含氟聚氨酯丙烯酸酯的合成及其热稳定性研究%Study on Synthesis and Thermal Stability of UV-curable Fluorinated Polyurethane Acrylate

    Institute of Scientific and Technical Information of China (English)

    刘金玲

    2013-01-01

      氟碳树脂具有优异的热稳定性,可以改善聚氨酯的耐热性,文章以异佛尔酮二异氰酸酯(IPDI)、聚丙二醇1000(PPG1000)、1,4-丁二醇、含氟丙烯酸酯共聚物二醇和甲基丙烯酸羟乙酯(HEMA)为主要原料合成可 UV 固化含氟聚氨酯丙烯酸酯预聚体。研究了含氟丙烯酸酯共聚物以及双键单体种类对聚氨酯涂膜热稳定性的影响。结果表明,将含氟丙烯酸酯共聚物引入聚氨酯中,可以显著的提高其热稳定性,同时,降低了聚氨酯硬段与软段的微相分离程度。%Fluorocarbon resins have excellent thermal stability and can improve the heat resistance of polyurethane. Fluorinated polyurethane acrylate prepolymers were synthesized by using isophorone diisocyanate(IPDI), polypropylene glycol(PPG1000), fluorine-containing acrylate copolymer glycol, 1,4-butanediol, hydroxyethyl methylacrylate(HEMA) as the main raw materials. The effects of fluorine-containing acrylate copolymer and double bond monomers on thermal stability of polyurethane films were investigated. The results showed that fluorine-containing acrylate copolymer can significantly improve polyurethane thermal stability, and reduce the degree of microphase separation of polyurethane hard segment and soft segment.

  8. The microphase-separated structure of polyurethane bulk and thin films

    International Nuclear Information System (INIS)

    The microphase-separated structure of polyurethane bulk and thin films were investigated using atomic force microscopy (AFM). The polyurethane (PUs) were synthesized with poly(oxytetramethylene) glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD) by a prepolymer method. The hard segment contents were 34 and 45 wt%. Polarized optical microscopy (POM) revealed that the 34 wt% PUE is homogeneous at a macroscopic level, while the 45 wt% one is macrophase-separated into two phases. One phase forms spherulites of ca. 2-5 μm in diameter. AFM observation for the 34 wt% PUE showed the microphase-separated structure, consisting of hard segment domains and a soft segment matrix. In contrast, for the 45 wt% PUE, a lot of the hard segment domains were observed in the spherulite region, indicating that spherulites include much amount of hard segment component, in contrast, outside of spherulite exhibited similar structure to that of 34 wt% one. For the PU bulk, the different microphase-separated structure in the inside and outside of spherulite was successfully observed for the first time. Also, the microphase-separated structure of PU films was investigated as a function of the film thickness. The PU films exhibited similar microphase-separated structure. For the thicker film (∼200 nm), the interdomain spacing almost corresponded to bulk one. On the other hand, that for the film thickness below 7nm dramatically decreased. This seems to be simply related to a decreasing space. We obtained the experimental data, which the phase-separated domain size of multiblock copolymer decreased with decreasing film thickness. (author)

  9. Acompanhamento do processo de fermentação para produção de cachaça através de métodos microbiológicos e físico-químicos com diferentes isolados de Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Thaís Louise Soares

    2011-03-01

    Full Text Available Com a crescente exigência do mercado consumidor por produtos de melhor qualidade, busca-se o constante aprimoramento da produção de cachaça, uma vez que todas as etapas da cadeia produtiva de bebidas fermento-destiladas são importantes. O objetivo deste trabalho foi acompanhar o processo de fermentação para produção de cachaça, utilizando diferentes isolados de Saccharomyces cerevisiae a partir da quantificação de metabólitos secundários por Cromatografia Gasosa. O acompanhamento do processo deu-se desde o preparo do inóculo até o final do processo fermentativo. O estudo foi conduzido na Universidade Federal de Lavras (UFLA. Foram utilizados 8 isolados de Saccharomyces cerevisiae inoculados em caldo de cana, dos quais foram retiradas amostras durante a fase de crescimento em sistema de batelada alimentada e fermentação. As amostras foram analisadas quanto à taxa de floculação, ºBrix e álcoois superiores. Os parâmetros avaliados apresentaram diferenças para cada isolado. O melhor isolado para a produção de cachaça foi o isolado UFLA CA116 por apresentar alto número de células viáveis, maior taxa de floculação, ausência 1-propanol, presença de 1,3 butanediol.

  10. A new crystal form of human tear lipocalin reveals high flexibility in the loop region and induced fit in the ligand cavity

    Energy Technology Data Exchange (ETDEWEB)

    Breustedt, Daniel A.; Chatwell, Lorenz; Skerra, Arne, E-mail: skerra@wzw.tum.de [Munich Center for Integrated Protein Science, CIPS-M, and Lehrstuhl für Biologische Chemie, Technische Universität München, 85350 Freising-Weihenstephan (Germany)

    2009-10-01

    The crystal structure of tear lipocalin determined in space group P2{sub 1} revealed large structural deviations from the previously solved X-ray structure in space group C2, especially in the loop region and adjoining parts of the β-barrel which give rise to the ligand-binding site. These findings illustrate a novel mechanism for promiscuity in ligand recognition by the lipocalin protein family. Tear lipocalin (TLC) with the bound artificial ligand 1,4-butanediol has been crystallized in space group P2{sub 1} with four protein molecules in the asymmetric unit and its X-ray structure has been solved at 2.6 Å resolution. TLC is a member of the lipocalin family that binds ligands with diverse chemical structures, such as fatty acids, phospholipids and cholesterol as well as microbial siderophores and the antibiotic rifampin. Previous X-ray structural analysis of apo TLC crystallized in space group C2 revealed a rather large bifurcated ligand pocket and a partially disordered loop region at the entrace to the cavity. Analysis of the P2{sub 1} crystal form uncovered major conformational changes (i) in β-strands B, C and D, (ii) in loops 1, 2 and 4 at the open end of the β-barrel and (iii) in the extended C-terminal segment, which is attached to the β-barrel via a disulfide bridge. The structural comparison indicates high conformational plasticity of the loop region as well as of deeper parts of the ligand pocket, thus allowing adaptation to ligands that differ vastly in size and shape. This illustrates a mechanism for promiscuity in ligand recognition which may also be relevant for some other physiologically important members of the lipocalin protein family.

  11. A new crystal form of human tear lipocalin reveals high flexibility in the loop region and induced fit in the ligand cavity

    International Nuclear Information System (INIS)

    The crystal structure of tear lipocalin determined in space group P21 revealed large structural deviations from the previously solved X-ray structure in space group C2, especially in the loop region and adjoining parts of the β-barrel which give rise to the ligand-binding site. These findings illustrate a novel mechanism for promiscuity in ligand recognition by the lipocalin protein family. Tear lipocalin (TLC) with the bound artificial ligand 1,4-butanediol has been crystallized in space group P21 with four protein molecules in the asymmetric unit and its X-ray structure has been solved at 2.6 Å resolution. TLC is a member of the lipocalin family that binds ligands with diverse chemical structures, such as fatty acids, phospholipids and cholesterol as well as microbial siderophores and the antibiotic rifampin. Previous X-ray structural analysis of apo TLC crystallized in space group C2 revealed a rather large bifurcated ligand pocket and a partially disordered loop region at the entrace to the cavity. Analysis of the P21 crystal form uncovered major conformational changes (i) in β-strands B, C and D, (ii) in loops 1, 2 and 4 at the open end of the β-barrel and (iii) in the extended C-terminal segment, which is attached to the β-barrel via a disulfide bridge. The structural comparison indicates high conformational plasticity of the loop region as well as of deeper parts of the ligand pocket, thus allowing adaptation to ligands that differ vastly in size and shape. This illustrates a mechanism for promiscuity in ligand recognition which may also be relevant for some other physiologically important members of the lipocalin protein family

  12. Experimental determination of the temperature dependence of water activities for a selection of aqueous organic solutions

    Directory of Open Access Journals (Sweden)

    G. Ganbavale

    2014-05-01

    Full Text Available This work presents experimental data of the temperature dependence of water activity in aqueous organic solutions relevant for tropospheric conditions (200–273 K. Water activity (aw at low temperatures (T is a crucial parameter for predicting homogeneous ice nucleation. We investigated temperature dependent water activities, ice freezing and melting temperatures of solutions, and vapour pressures of a selection of atmospherically relevant aqueous organic systems. To measure aw over a wide composition range and with a focus on low temperatures, we use various aw measurement techniques and instruments: a dew point water activity meter, an electrodynamic balance (EDB, differential scanning calorimetry (DSC, and a setup to measure the total gas phase pressure at equilibrium over aqueous solutions. Water activity measurements were performed for aqueous multicomponent and multifunctional organic mixtures containing the functional groups typically found in atmospheric organic aerosols, such as hydroxyl, carboxyl, ketone, ether, ester, and aromatic groups. The aqueous organic systems studied at several fixed compositions over a considerable temperature range differ significantly in their temperature dependence. Aqueous organic systems of 1,4-butanediol and methoxyacetic acid show a moderate decrease in aw with decreasing temperature. The aqueous M5 system (a multicomponent system containing five different dicarboxylic acids and aqueous 2-(2-ethoxyethoxyethanol solutions both show a strong increase of water activity with decreasing temperature at high solute concentrations for TTaw can be reversed at low temperatures and that linear extrapolations of high temperature data may lead to erroneous predictions. To avoid this, experimentally determined aw at low temperature are needed to improve thermodynamic models towards lower temperatures and for improved predictions of the ice nucleation ability of organic–water systems.

  13. Combined enzymatic hydrolysis and fermentation of aspenwood using enzymes derived from Trichoderma harzianum E58

    Energy Technology Data Exchange (ETDEWEB)

    1989-05-01

    A project was initiated to study the conversion of aspenwood to ethanol, butanol or butanediol. The conversion method consisted of steam explosion pretreatment, followed by the enzymatic hydrolysis of the carbohydrate polymers, cellulose and hemicellulose. The enzyme was derived from a wild strain of the fungus Trichoderma harzianum E58, chosen because it produces a cellulose system that can degrade crystalline cellulose to glucose. The aspenwood was steamed at 240{degree}C for 80 seconds and then water and alkali extracted. The insoluble residue was 84% cellulose and was used for both enzyme production and the production of glucose, which was fermented to ethanol. Before fermentation of the water-soluble fraction was possible, the acetylxylan had to be hydrolyzed and the inhibitors (glucose, galactose, acetic and uronic acids, and lignin- and sugar-degradation products) removed. Enzymatic hydrolysis was found to generate less fermentation inhibitors than sulfuric acid hydrolysis. Due to market factors, fermentation research centred on the production of ethanol from hemicellulose, using the yeast Pichia stipitis. Although lignin had no effect on hydrolysis, it increased the bulk to be handled, in combination with small amounts of cellulose was found to strongly adsorb the cellulose enzymes, and broke down to produce inhibitors of the cellulose complex of T. harzanium and the enzyme production phase. Thus, it was advantageous to remove the lignin prior to enzyme production and cellular hydrolysis. None of the strategies were successful in decreasing the amount of cellulose required for enzyme production. It was concluded that T. harzianum E58 is unsuitable for use in a commercial bioconversion project. 59 refs., 31 figs., 31 tabs.

  14. 固相微萃取-气质联用分析柿子甜酒中的香气成分%Analysis of Aroma Constituents in Persimmon Sweet Wine by Solid-phase Micro-extraction and GC-MS

    Institute of Scientific and Technical Information of China (English)

    张媛; 张军翔; 刘亚辉

    2013-01-01

    The flavoring compositions were extracted from persimmon sweet wine by solvent extraction and then analyzed by GC/MS.Their relative contents were determined by peak area normalization method.32 volatile compounds were separated and identified,including lipid,alcohols,organic acids,aldehyde and a small amount of paraffin.The detection results showed that ethyl caprylate,phenylethyl alcohol,decanoic acid,ethyl ester,dimethyl phthalate,2,3-butanediol had relatively higher contents than the others,probably being the main flavoring compositions for persimmon sweet wine.%采用固相微萃取法提取柿子甜酒中的香气成分,用气相色谱-质谱仪进行测定,结合计算机检索技术对分离化合物进行分离鉴定,并应用色谱峰面积归一法测定各成分的相对含量.在柿子甜酒中共定性出32中挥发性成分,其中主要包括脂类、醇类、有机酸类、醛类和少量烷烃.结果表明,辛酸乙酯、苯乙醇、癸酸乙酯、邻苯二甲酸二甲酯、2,3-丁二醇等含量相对较高,可能是柿子甜酒香气形成的主要的成分.

  15. Production of Succinic Acid for Lignocellulosic Hydrolysates

    Energy Technology Data Exchange (ETDEWEB)

    Davison, B.H.; Nghiem, J.

    2002-06-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) is to add and test new metabolic activities to existing microbial catalysts for the production of succinic acid from renewables. In particular, they seek to add to the existing organism the ability to utilize xylose efficiently and simultaneously with glucose in mixtures of sugars or to add succinic acid production to another strain and to test the value of this new capability for production of succinic acid from industrial lignocellulosic hydrolyasates. The Contractors and Participant are hereinafter jointly referred to as the 'Parties'. Research to date in succinic acid fermentation, separation and genetic engineering has resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on repliminary laboratory findings and predicted catalytic parameters. The initial target markets include succinic acid itself, succinate salts, esters and other derivatives for use as deicers, solvents and acidulants. The other commodity products from the succinic acid platform include 1,4-butanediol, {gamma}-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Current economic analyses indicate that this platform is competitive with existing petrochemical routes, especially for the succinic acid and derivatives. The report presents the planned CRADA objectives followed by the results. The results section has a combined biocatalysis and fermentation section and a commercialization section. This is a nonproprietary report; additional proprietary information may be made available subject to acceptance of the appropriate proprietary information agreements.

  16. Correlação entre propriedades mecânicas e parâmetros estruturais de poliuretanos à base de poli(épsilon-caprolactona Relationships between mechanical properties and structural parameters of polyurethanes containing poly(epsilon-caprolactone

    Directory of Open Access Journals (Sweden)

    Juliana Kloss

    2005-03-01

    Full Text Available No presente trabalho foram preparados poliuretanos (PUs segmentados. Primeiramente foi obtido um pré-polímero (PP a partir da reação de 2,4 e 2,6 - diisocianato de tolileno (TDI e poli(épsilon-caprolactona diol (PCL. A PCL é um poliéster biodegradável que constituiu o segmento flexível do PU. O segmento rígido foi constituído por unidades uretânicas provenientes da ligação entre as extremidades isocianato do PP e as hidroxilas do extensor de cadeia: 1,4 - butanodiol (BDO, ou sacarose (SAC, ou glicose (GLY. Foram avaliadas as propriedades mecânicas e dinâmico-mecânicas dos poliuretanos obtidos e estas foram correlacionadas com os parâmetros estruturais. Os resultados foram justificados com base na intensidade das interações de hidrogênio, na mistura de fases, no volume dos extensores cíclicos e na presença de ligações cruzadas. Estes PUs estão sendo estudados com vistas à preparação de materiais biodegradáveis com propriedades mecânicas úteis.Segmented polyurethanes containing polycaprolactone as soft segment were prepared taking into account the biodegradable character of this compound. The hard block was produced by the reaction between tolylene diisocyanate and a chain extender (1,4 butanediol, sucrose or glucose. The mechanical and dynamical properties were evaluated as a function of the contents of rigid blocks. The results were analyzed on the basis of the intermolecular interactions, mainly H bonds, phase mixture, volume of cyclic chain extenders and crosslinking. These polyurethanes are being studied aiming at the preparation of biodegradable materials with useful mechanical properties.

  17. Preparation of Quaternized Cationic Waterborne Polyurethane and its Fixative Performance on Reactive Dyes%季胺化阳离子水性聚氨酯制备及其对活性染料的固色性能

    Institute of Scientific and Technical Information of China (English)

    张梦月; 刘俊琦; 刘玉峰; 权衡

    2014-01-01

    A set of silicon-modified cationic waterborne polyurethane reactive dyes wet rubbing fastness agent having high activity is prepared by isophorone diisocyanate, 1,4-butanediol, N-butyl diethanolamine as hard monomer, mixed polyether as soft monomer, hydroxyl alkyl polysiloxane as modified monomers. The effects that quaternary amination degree of the reactive polyurethane polymer have on the wet rubbing fastness ascend agent are studied. The results prove that quaternary ammonium salt structure make polyurethane macromolecules show excellent resistance to acid and alkali stability;however, the polyurethane macromolecules of strong cationic strength are not conducive to improve the fixation textile wet rubbing fastness.%以异佛尔酮二异氰酸酯、1,4-丁二醇、N-丁基二乙醇胺为硬单体,混合聚醚为软单体,羟烃基聚硅氧烷为改性单体,制备了一组具有较高化学活性的有机硅改性阳离子水性聚氨酯活性染料湿摩擦牢度提升剂,研究了活性聚氨酯高分子的季铵化程度对湿摩擦牢度提升剂性能的影响。研究结果表明:季铵盐结构使得聚氨酯大分子表现出优异的耐酸、耐碱稳定性;较高阳离子强度的聚氨酯大分子并不利于其固色纺织品湿摩擦牢度的改善。

  18. Difference in tumor incidence and other tissue responses to polyetherurethanes and polydimethylsiloxane in long-term subcutaneous implantation into rats.

    Science.gov (United States)

    Nakamura, A; Kawasaki, Y; Takada, K; Aida, Y; Kurokama, Y; Kojima, S; Shintani, H; Matsui, M; Nohmi, T; Matsuoka, A

    1992-05-01

    The long-term (1- and 2-year) adverse tissue responses including tumor formation by subcutaneous implantation of polyurethanes (PUs) and silicone (Sil) films into rats were compared. The weight-averaged molecular weights (Mw) of the PUs prepared from 4,4'-diphenylmethanediisocyanate, poly(tetramethyleneglycol) of Mn = 1000 and 1,4-butanediol are 220,000 (U-4), 124,000 (U-6), and 55,600 (U-8). The 50:50 mixed film of U-6 and silicone (U-6/sil) was prepared by roll-mixing of the noncured silicone and the U-6 solution followed by evaporation of the solvent and heat-curing at 70 degrees C. The tissue responses around implants were classified into four groups as follows: (A) tumor, (B) atypical cell proliferation accompanied by preneoplastic changes, (C) cell proliferation without preneoplastic changes, (D) no obvious responses. In both implantation periods, the PUs gave higher incidents of the adverse responses including tumor formation in comparison to Sil. No significant molecular weight-dependent trend was found in a 1-year study using U-4, 6, and 8. Significant PU-dose-dependent trends were found in a 2-year study: the total active incidence (A+B+C), U-6(22/29) greater than U-6/sil(11/29) greater than sil(7/28); tumor incidence (A), U-6(11/29) greater than U-6/sil(2/29) = sil(2/28). No detectable amounts of 4,4'-methylenedianiline (MDA) were found in the PUs. The methanol extracts from the PUs were negative in the mutagenicity tests. These indicate no relationship between the tumor formation by the PU films and the mutagenicities of the chemicals (mainly oligomers) leached from the PUs. PMID:1512283

  19. Study on the Waterproof and Breathable Properties of Polyether/Polyester Hydrophilic Polyurethane%聚醚/聚酯型亲水性聚氨酯防水透湿性能研究

    Institute of Scientific and Technical Information of China (English)

    权衡; 倪丽杰; 姜会钰; 黎谦; 涂超

    2013-01-01

    Six groups of segmented waterproof and breathable hydrophilic polyurethanes coatings based on mixed polyether or polyether/polyester hydrophilic soft monomers were prepared using 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO) as hard segments.Furthermore,the effect of microstructure and soft segment on moisture permeability and water resistance of the hydrophilic polyurethanes was researched.The results showed that some factors had remarkable effects on the waterproof and breathable,including the soft segment structure,composition,molecular weight,concentration and the degree of microphase separation.The most important factor on waterproof and breathable of hydrophilic polyurethane was the soft segment hydrophilic and activity.%以4,4'-二苯基甲烷二异氰酸酯(MDI)和1,4-丁二醇(BDO)为硬单体,制备了6组聚醚与聚酯或不同聚醚混合单体为软链段的嵌段型亲水性聚氨酯防水透湿涂层剂.研究了聚氨酯材料的微结构和软段结构对其防水、透湿性能的影响.结果表明,亲水性聚氨酯软链段的结构、组成、相对分子质量和含量及软、硬段相区间的微相分离程度对材料防水透湿性能的影响较大,亲水性聚氨酯的防水透湿性能主要取决于其中亲水性软链段的亲水性及其活动性.

  20. 一株红色素产生菌H2的初步鉴定%Preliminary Identification of A Strain H2 Producing Red Pigments

    Institute of Scientific and Technical Information of China (English)

    赵昌会

    2012-01-01

    A bacterial strain producing red pigments was isolated from marine mud,its biochemical and physiological characteristics,16S rDNA sequence were investigated.The result showed that the strain was Gram negative,could produce H2S,2,3-butanediol,peroxidase,gelatinase,the growth temperature was 4~37℃.It could use maltose,cellobiase,glycerol,D-glucose,D-fructose,trehalose,sucrose,D-mannitol etc.as carbon resource,and could use peptone,yeast extract and beef extract as nitrogen resource.The strain H2 was identified as Serratia marcescens by 16S rDNA,and phylogenetic trees were constructed by neighbor joining.%从海泥中分离纯化得到1株产红色素细菌,对该菌进行生理生化分析和16SrDNA鉴定。结果表明:该菌为革兰氏阴性,H2S、V.P.、酶触及明胶液化试验呈阳性,可在4~37℃下生长。可利用的碳源有麦芽糖、纤维二糖、甘油、D-葡萄糖、D-果糖、海藻糖、蔗糖及D-甘露醇等,可利用的氮源有蛋白胨、酵母膏和牛肉膏等;16SrDNA鉴定为Serratia marcescens,并建立了H2系统发育树。

  1. Whole genome sequencing and analysis of plant growth promoting bacteria isolated from the rhizosphere of plantation crops coconut, cocoa and arecanut.

    Directory of Open Access Journals (Sweden)

    Alka Gupta

    Full Text Available Coconut, cocoa and arecanut are commercial plantation crops that play a vital role in the Indian economy while sustaining the livelihood of more than 10 million Indians. According to 2012 Food and Agricultural organization's report, India is the third largest producer of coconut and it dominates the production of arecanut worldwide. In this study, three Plant Growth Promoting Rhizobacteria (PGPR from coconut (CPCRI-1, cocoa (CPCRI-2 and arecanut (CPCRI-3 characterized for the PGP activities have been sequenced. The draft genome sizes were 4.7 Mb (56% GC, 5.9 Mb (63.6% GC and 5.1 Mb (54.8% GB for CPCRI-1, CPCRI-2, CPCRI-3, respectively. These genomes encoded 4056 (CPCRI-1, 4637 (CPCRI-2 and 4286 (CPCRI-3 protein-coding genes. Phylogenetic analysis revealed that both CPCRI-1 and CPCRI-3 belonged to Enterobacteriaceae family, while, CPCRI-2 was a Pseudomonadaceae family member. Functional annotation of the genes predicted that all three bacteria encoded genes needed for mineral phosphate solubilization, siderophores, acetoin, butanediol, 1-aminocyclopropane-1-carboxylate (ACC deaminase, chitinase, phenazine, 4-hydroxybenzoate, trehalose and quorum sensing molecules supportive of the plant growth promoting traits observed in the course of their isolation and characterization. Additionally, in all the three CPCRI PGPRs, we identified genes involved in synthesis of hydrogen sulfide (H2S, which recently has been proposed to aid plant growth. The PGPRs also carried genes for central carbohydrate metabolism indicating that the bacteria can efficiently utilize the root exudates and other organic materials as energy source. Genes for production of peroxidases, catalases and superoxide dismutases that confer resistance to oxidative stresses in plants were identified. Besides these, genes for heat shock tolerance, cold shock tolerance and glycine-betaine production that enable bacteria to survive abiotic stress were also identified.

  2. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Science.gov (United States)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan

    2015-09-01

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  3. Polystyrene-divinylbenzene-glycidyl methacrylate stationary phase grafted with poly (amidoamine) dendrimers for ion chromatography.

    Science.gov (United States)

    Guo, Dandan; Lou, Chaoyan; Zhang, Peimin; Zhang, Jiajie; Wang, Nani; Wu, Shuchao; Zhu, Yan

    2016-07-22

    In this work, a novel ion exchange stationary phase based on different generations of poly (amidoamine) dendrimers (PAMAM) was developed for the determination of inorganic anions and carbohydrates. Synthesis of the PAMAM was carried out with the polymerization reaction of ethylenediamine and methyl acrylate. The synthesized PAMAM was then grafted to the polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) to form PAMAM-based beads. These beads were finally modified with 1,4-butanediol diglycidyl ether (BDDE) to generate the anion exchanger, which were characterized by scanning electron microscopy (SEM), brunauer-emmett-teller (BET), fourier transform infrared spectroscopy (FTIR), and elemental analysis. Elemental analysis, breakthrough curves and capacity factors showed that more epoxy groups and higher PAMAM generations in stationary phase could result in higher anion exchange capacity. The efficiency, durability and stability of the proposed anion exchanger were investigated by using six inorganic anions (fluoride, chloride, nitrite, bromide, nitrate and sulfate) and four carbohydrates (trehalose, glucose, maltotriose and galacturonic acid) as analytes, respectively. The reliability of the proposed ion chromatographic stationary phase was demonstrated by determining the content of galacturonic acid in polysaccharides from Poria cocos and Atractylodes macrocephala. The relative standard deviations of retention time, peak height, and peak area for galacturonic acid were 0.39%, 1.22%, and 2.02%, respectively. The spiked recoveries were in the range of 88.29%-100.51% for plant polysaccharides. Due to the good structural homogeneity, intense internal porosity, biological compatibility and high density of active groups in PAMAM, this grafted stationary phase showed good ion-exchange characteristics, especially in biological charged molecules. PMID:27311659

  4. Induction, purification and characterization of a novel manganese peroxidase from Irpex lacteus CD2 and its application in the decolorization of different types of dye.

    Science.gov (United States)

    Qin, Xing; Zhang, Jie; Zhang, Xiaoyu; Yang, Yang

    2014-01-01

    Manganese peroxidase (MnP) is the one of the important ligninolytic enzymes produced by lignin-degrading fungi which has the great application value in the field of environmental biotechnology. Searching for new MnP with stronger tolerance to metal ions and organic solvents is important for the maximization of potential of MnP in the biodegradation of recalcitrant xenobiotics. In this study, it was found that oxalic acid, veratryl alcohol and 2,6-Dimehoxyphenol could stimulate the synthesis of MnP in the white-rot fungus Irpex lacteus CD2. A novel manganese peroxidase named as CD2-MnP was purified and characterized from this fungus. CD2-MnP had a strong capability for tolerating different metal ions such as Ca2+, Cd2+, Co2+, Mg2+, Ni2+ and Zn2+ as well as organic solvents such as methanol, ethanol, DMSO, ethylene glycol, isopropyl alcohol, butanediol and glycerin. The different types of dyes including the azo dye (Remazol Brilliant Violet 5R, Direct Red 5B), anthraquinone dye (Remazol Brilliant Blue R), indigo dye (Indigo Carmine) and triphenylmethane dye (Methyl Green) as well as simulated textile wastewater could be efficiently decolorized by CD2-MnP. CD2-MnP also had a strong ability of decolorizing different dyes with the coexistence of metal ions and organic solvents. In summary, CD2-MnP from Irpex lacteus CD2 could effectively degrade a broad range of synthetic dyes and exhibit a great potential for environmental biotechnology.

  5. Polymeric nanoparticles for nonviral gene therapy extend brain tumor survival in vivo.

    Science.gov (United States)

    Mangraviti, Antonella; Tzeng, Stephany Yi; Kozielski, Kristen Lynn; Wang, Yuan; Jin, Yike; Gullotti, David; Pedone, Mariangela; Buaron, Nitsa; Liu, Ann; Wilson, David R; Hansen, Sarah K; Rodriguez, Fausto J; Gao, Guo-Dong; DiMeco, Francesco; Brem, Henry; Olivi, Alessandro; Tyler, Betty; Green, Jordan J

    2015-02-24

    Biodegradable polymeric nanoparticles have the potential to be safer alternatives to viruses for gene delivery; however, their use has been limited by poor efficacy in vivo. In this work, we synthesize and characterize polymeric gene delivery nanoparticles and evaluate their efficacy for DNA delivery of herpes simplex virus type I thymidine kinase (HSVtk) combined with the prodrug ganciclovir (GCV) in a malignant glioma model. We investigated polymer structure for gene delivery in two rat glioma cell lines, 9L and F98, to discover nanoparticle formulations more effective than the leading commercial reagent Lipofectamine 2000. The lead polymer structure, poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) end-modified with 1-(3-aminopropyl)-4-methylpiperazine, is a poly(β-amino ester) (PBAE) and formed nanoparticles with HSVtk DNA that were 138 ± 4 nm in size and 13 ± 1 mV in zeta potential. These nanoparticles containing HSVtk DNA showed 100% cancer cell killing in vitro in the two glioma cell lines when combined with GCV exposure, while control nanoparticles encoding GFP maintained robust cell viability. For in vivo evaluation, tumor-bearing rats were treated with PBAE/HSVtk infusion via convection-enhanced delivery (CED) in combination with systemic administration of GCV. These treated animals showed a significant benefit in survival (p = 0.0012 vs control). Moreover, following a single CED infusion, labeled PBAE nanoparticles spread completely throughout the tumor. This study highlights a nanomedicine approach that is highly promising for the treatment of malignant glioma.

  6. Mono-fermentation of glycerine - Fermentation of a substrate in a dominant amount. Final report; Monovergaerung von Glycerin - Vergaerung von einem Substrat in dominierender Menge. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Erb, D.; Bueeler, E.; Spicher, M.

    2008-02-15

    The present study investigated the feasibility of a mono fermentation of the glycerine-fraction from biodiesel production. Part of the experiments took place in a single-stage, continuous system with 700 l usable volume. The maximum yield of biogas of the glycerine-fraction is 1100 l/l of glycerine, or 870 l/kg of glycerine, in continuous operation. The average methane content is 70 %. The adaptation rate of the biomass at the substrate of glycerine-fraction is high. Two or three days after starting the feed 100 % degradation rates will be achieved. The single-stage, continuous fermentation of the glycerine-fraction at 40 {sup o}C runs only stable at very low organic loading rate (0.65 kg oDM/(d m{sup 3})) and is therefore not currently economical. At higher organic loading rates (1.5 to 3.0 kg oDM/(d m{sup 3})) the adapted biomass collapsed after about 20 days due to massive instability of the process. A two-stage system with separate hydrolysis stage could probably allow a stable fermentation as search for literature has shown. Fed-batch experiments in the laboratory of the University of Waedenswil, Switzerland (ZHAW) demonstrated that the glycerine-fraction from biodiesel production is slightly better degradable than pure glycerine. The process dysfunctions arise because of the inhibition of intermediates resulting from the degradation of glycerine. At higher concentrations of 1.2-propanediol and 2.3-butanediol the degradation was incomplete. Further inhibitors can not be excluded. The failed stability of the process is not due to the lack of main nutrients or trace elements. (author)

  7. Structural and magnetic properties of Co{sub x}Fe{sub 3−x}O{sub 4} versus Co/Fe molar ratio

    Energy Technology Data Exchange (ETDEWEB)

    Dippong, Thomas, E-mail: dippong.thomas@yahoo.ro [Technical University of Cluj-Napoca, North University Center of Baia Mare, Department of Chemistry and Biology, 76 Victoriei Street, 430122 Baia Mare (Romania); Levei, Erika Andrea, E-mail: erika.levei@icia.ro [INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath Street, 400293 Cluj-Napoca (Romania); Diamandescu, Lucian [National Institute of Materials Physics, 105bis Atomistilor Street, 077125 Magurele (Romania); Bibicu, Ion, E-mail: bibicu@infim.ro [National Institute of Materials Physics, 105bis Atomistilor Street, 077125 Magurele (Romania); Leostean, Cristian [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293 Cluj-Napoca (Romania); Borodi, Gheorghe, E-mail: borodi@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293 Cluj-Napoca (Romania); Barbu Tudoran, Lucian, E-mail: lbarbu@hasdeu.ubbcluj.ro [Babes-Bolyai University, Faculty of Biology and Geology, 44 Bilascu Street, 400015 Cluj-Napoca (Romania)

    2015-11-15

    Co{sub x}Fe{sub 3−x}O{sub 4} (x=0.5–2.5) magnetic nanoparticles were synthesized via redox reaction between cobalt nitrate, iron nitrate and 1-4-butanediol using five Co/Fe molar ratios, followed by calcination at 1000 °C. Single phase nanoscaled cobalt ferrite was obtained at x=1.0 and at slight Co excess (x=1.5), while at high Co/Fe molar ratios (x=2.0 and x=2.5) the prevailing phase was CoO accompanied by CoFe{sub 2}O{sub 4} traces. The highest values of coercive field and saturation magnetization were obtained for the sample at x=1.0, while the lowest values were obtained in the sample with the highest Co excess (x=2.5). The results indicated that the used synthesis route was suitable for the synthesis of cobalt ferrite with moderate saturation magnetization and high coercive field values. - Highlights: • Cobalt ferrite magnetic nanoparticles were synthesized by redox reaction. • The magnetic properties of Co{sub x}Fe{sub 3−x}O{sub 4} depend on the Co/Fe ratio. • Nanoparticles were spherical with sizes in the range of 30–73 nm. • At Co/Fe stoichiometric ratio and slight Co excess single phase CoFe{sub 2}O{sub 4} results. • The critical role of Co concentration in the synthesized samples was revealed.

  8. Hygroscopic and phase separation properties of ammonium sulfate/organic/water ternary solutions

    Directory of Open Access Journals (Sweden)

    M. A. Zawadowicz

    2015-03-01

    Full Text Available Atmospheric aerosol particles are often partially or completely composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have well-defined deliquescence and efflorescence points at which they take up and lose water, respectively. Deliquescence and efflorescence of simple inorganic salt particles have been investigated by a variety of methods, such as IR spectroscopy, tandem mobility analysis and electrodynamic balance. Field measurements have shown that atmospheric aerosols are not typically pure inorganic salt, instead they often also contain organic species. There is ample evidence from laboratory studies that suggests that mixed particles exist in a phase-separated state, with an aqueous inorganic core and organic shell. Although phase separation has not been measured in situ, there is no reason it would not also take place in the atmosphere. Many recent studies have focused on microscopy techniques that require deposition of the aerosol on a glass slide, possibly changing its surface properties. Here, we investigate the deliquescence and efflorescence points, phase separation and ability to exchange gas-phase components of mixed organic and inorganic aerosol using a flow tube coupled with FTIR spectroscopy. Ammonium sulfate aerosol mixed with organic polyols with different O : C ratios, including 1,4-butanediol, glycerol, 1,2,6-hexanetriol, 1,2-hexanediol, and 1,5-pentanediol have been investigated. Those constituents correspond to materials found in the atmosphere in great abundance, and therefore, particles prepared in this study should mimic atmospheric mixed phase aerosol particles. The results of this study tend to be in agreement with previous microscopy experiments, with several key differences, which possibly reveal a size-dependent effect on phase separation in organic/inorganic aerosol particles.

  9. Biosynthesis of poly(3-hydroxybutyrate) and its copolymers by Yangia sp. ND199 from different carbon sources.

    Science.gov (United States)

    Huu Phong, Tran; Van Thuoc, Doan; Sudesh, Kumar

    2016-03-01

    A halophilic bacterium isolated from mangrove soil sample in Northern Vietnam, Yangia sp. ND199 was found capable of producing homopolymer poly(3-hydroxybutyrate) [P(3HB)], copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)], and copolymer poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] from different carbon sources. The presence of 3HB, 3HV, and 4HB monomers were confirmed by gas chromatography and nuclear magnetic resonance analysis. Only P(3HB) was produced using carbon sources such as fructose or by a combination of fructose with 1,5-pentanediol, 1,6-hexanediol, sodium hexanoate, or sodium octanoate. The biosynthesis of P(3HB-co-3HV) was achieved by adding cosubstrates such as sodium valerate and sodium heptanoate. When 1,4-butanediol, γ-butyrolactone or sodium 4-hydroxybutyrate was added to the culture medium, P(3HB-co-4HB) containing 4.0-7.1mol% 4HB fraction was accumulated. The molecular weights and thermal properties of polyesters were determined by gel permeation chromatography and differential scanning calorimeter, respectively. The results showed that Yangia sp. ND199 is able to produce polyester with high weight average molecular weight ranging from 1.3×10(6) to 2.2×10(6) Dalton and number average molecular weight ranging from 4.2×10(5) to 6.9×10(5) Dalton. The molecular weights, glass transition temperature as well as melting temperature of homopolymer P(3HB) are higher than those of copolymer P(3HB-co-3HV) or P(3HB-co-4HB). PMID:26708435

  10. Influence of the content of hard segments on the properties of novel urethane-siloxane copolymers based on a poly(ε-caprolactone-b-poly(dimethylsiloxane-b-poly(ε- caprolactone triblock copolymer

    Directory of Open Access Journals (Sweden)

    Antić Vesna V.

    2011-01-01

    Full Text Available A series of novel thermoplastic urethane-siloxane copolymers (TPUSs based on a α,ω-dihydroxy-[poly(ε-caprolactone-bpoly( dimethylsiloxane-b-poly(ε-caprolactone] (α,ω-dihydroxy-PCLPDMS- PCL triblock copolymer, 4,4?-methylenediphenyl diisocyanate (MDI and 1,4-butanediol (BD was synthesized. The effects of the content (9-63 wt. % of hard urethane segments and their degree of polymerization on the properties of the segmented TPUSs were investigated. The structure, composition and hard segment degree of polymerization of the hard segments were examined using 1H- and quantitative 13C-NMR spectroscopy. The degree of crystallinity of the synthesized copolymers was determined using wide-angle X-ray scattering (WAXS. The surface properties were evaluated by measuring the water contact angle and water absorption. In the series of the TPUSs, the average degree of polymerization of the hard segments was varied from 1.2 to 14.4 MDI-BD units. It was found that average values from 3.8 to 14.4 MDI-BD units were effective segment lengths for crystallization of hard segments, which resulted in an increase in the degree of microphase separation of the copolymers. Spherulite-like superstructures were observed in copolymer films by scanning electron microscopy (SEM, which are believed to arise from the crystallization of the hard segments and/or PCL segments, depending on the content of the hard segments. The surface of the copolymers became more hydrophobic with increasing weight fraction of PDMS. The synthesized copolymers based on a PCL-PDMS-PCL segment showed good thermal stability, which increased with increasing content of soft PDMS segments, as was confirmed by the value of the starting temperature of thermal degradation.

  11. 以马铃薯残渣为原料的端羟基乳酸预聚物的制备%Synthesis of Hydroxyl Terminated Prepolymer of Polylactic Acid Using Potato Waste as Raw Materials

    Institute of Scientific and Technical Information of China (English)

    张红印; Fu-H sianChang; 陈少峰

    2011-01-01

    [目的]利用马铃薯残渣为原料合成乳酸预聚物,为聚乳酸的生产工艺改造提供理论依据.[方法]将由马铃薯残渣发酵所得的乳酸采用熔融缩聚法合成乳酸预聚物,并对此方法进行了优化.[结果]最佳工艺:催化剂辛酸亚锡的用量1%,熔融缩聚时间10 h,反应温度170℃,1,4-丁二醇用量1%.[结论]熔融缩聚法聚合所得的聚乳酸预聚物的最高分子量为3059 g/mol,用马铃薯残渣为原料合成乳酸预聚物简单易行,该方法提供了一种新的废物利用途径.%[Objective]The synthesis of hydroxyl terminated prepolyraer of polylactic acid using potato waste was studied to provide theoretical basis for reformation of productive technology of polylactic acid. [ Methods ] This study applied direct condensation method for polymerization of lactic acid produced from potato waste and the methods were optimized. [ Result]The results showed the following optimum conditions for polymerization :catalyst dosage:1%,reaction time: 10 h,reaction temperature; 170℃ ,1,4 - Butanediol dosage;1%. [Conclusion]The highest molecular weight of polylactic acid prepolymer obtained by melt condensation polymerization reached 3 059 g/mol. This study provides an alternative substitute for polylactic acid synthesis,which helps transfer low value potato waste to high value product.

  12. Comparative study of aromatic compounds in fruit wines from raspberry, strawberry, and mulberry in central Shaanxi area

    Directory of Open Access Journals (Sweden)

    Yiming Feng

    2015-11-01

    Full Text Available Background: Although grape wines have firmly dominated the production and consumption markets of fruit wines, raspberry, strawberry, and mulberry have been utilized to make wines because of their joyful aroma and high contents of polyphenolic phytochemicals and essential fatty acids. However, little is known about aromatic compounds of the wines produced from these three fruits. Methods: The aromatic composition of fruit wines produced from raspberry, strawberry, mulberry, and red grape was analyzed by GC-MS. Odor activity values (OAVs and relative odor contributions (ROCs were used to estimate the sensory contribution of the aromatic compounds to the overall flavor of the wines. Results: In strawberry, raspberry, and mulberry wines, 27, 30, and 31 odorants were detected, respectively. Alcohols formed the most abundant group, followed by esters and acids. The grape wine contained a wider variety (16 types of alcohols, and 4-methyl-2-pentanol and 2,3-butanediol were not present in the three fruit wines. The quantity of esters in raspberry (1.54% and mulberry wines (2.08% were higher than those of strawberry wine (0.78%, and mulberry wine contained more types of esters. There were no significant differences of acids between the three fruit wines and the control wine. In addition, 2-heptanone, 2-octanone, 2-nonanone, and 2-undecanone were unique to raspberry wine, and nonanal was present only in mulberry wine. The indistinguishable aroma of the three fruit wines was attributed to the dominance of fruity and floral odor components derived from ethyl esters of fatty acids and their contributions to the global aroma of the three fruit wines. Conclusion: The present study demonstrated that there were significant differences in the volatile components of fruit wines made from raspberry, strawberry, and mulberry. The aroma compounds were more abundant in the raspberry and mulberry wines than in the strawberry wine, but the quality of strawberry wine was

  13. 玉米芯的综合利用研究技术进展%Research Progress in Comprehensive Utilization of Corn Cobs

    Institute of Scientific and Technical Information of China (English)

    李昌文; 张丽华; 纵伟; 李江涛

    2015-01-01

    玉米芯是玉米生产和加工的副产物,资源丰富。玉米芯通常被当作饲料和燃料使用或作为废弃物,未能充分利用。对玉米芯进行开发和综合利用,可提高农副产品的经济效益和社会效益。叙述了以玉米芯为原料生产还原糖、木糖、木聚糖、多酚、多糖、糠醛、黄原胶、生物质活性炭、木质素、丁醇、2,3-丁二醇、改性玉米芯的生产工艺和研究进展,为玉米芯的综合利用提供参考。%As the by-product of corn processing,corn cob abounds in China. Corn cob is usually used in feed and fuel field or discarded. The economic and social benefit of agricultural product can be increased by the comprehensive utilization of corn cob. The development of studies on processing techniques of glucose, xylose, xylan, polyphenol, polysaccharide, furfural, xamthan gum, activated carbon, lignin, butanol, 2,3 -butanediol and modified corncob powder with corn cob as material were mainly introduced , which provided the references of comprehensive utilization of corn cob.

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

    Science.gov (United States)

    Zhu, Jianhui

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

  15. Volatile Constituents from Three Parts of Cucurbita Moschata Duch. (Miben) by Head-Space Solid Phase Micro-Extraction Coupled with GC-MS%HS-SPME-GC-MS分析蜜本南瓜3个部位的挥发性成分

    Institute of Scientific and Technical Information of China (English)

    张伟; 彭涛; 卢引; 顾雪竹; 李昌勤; 康文艺

    2013-01-01

    This study was aimed to analyze the volatile constituents from flower, stem tip and seed of Cucurbita moschata Duch.(Miben). The volatiles were analyzed by head-space solid micro-extraction, coupled with GC-MS and Kovats indices for the first time . The results showed that 22 compounds were identified from the flower , 20 from the stem tip and 21 from the seed of the C. moschata (Miben). The total essential constituents from each part were 91 . 89%, 89 . 24% and 96 . 26%, respectively . A total of 10 compounds in the flower and stem tip were mutual. And 3 compounds in the flower, stem tip and seed were mutual. It was concluded that the β-bourbonene (17.57%) and heneicosane (11.90%) were the highest components of the total essential constituents of the flower of C. moschata (Miben). Decanal (28.77%) was the highest components of the stem tip and hexadecanoic acid ethyl ester (29.12%), 2,3-butanediol (16.90%) and linoleic acid ethyl ester (16.52%) were the highest compo-nents of seed of C. moschata (Miben).%目的:对蜜本南瓜花、茎尖和籽的挥发性成分进行分析。方法:采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),结合保留指数法,首次分析蜜本南瓜3个部位的挥发性成分。结果:从蜜本南瓜花、茎尖、籽中分别鉴定出22、20和21个挥发性成分,占总峰面积的91.89%、89.24%和96.26%。其中花和茎尖共有10个共有成分,花、茎尖和籽有3个共有成分。结论:蜜本南瓜花中茁-波旁烯(17.57%)和二十一烷(11.90%)含量较高;蜜本南瓜茎尖中癸醛(28.77%)含量最高;籽中棕榈酸乙酯(29.12%)、2,3-丁二醇(16.90%)和亚油酸乙酯(16.52%)含量较高。

  16. Curing Temperature on Performance of Low Viscosity Epoxy%低黏度环氧树脂高温固化的性能影响

    Institute of Scientific and Technical Information of China (English)

    刘魁; 卢敏; 冯学斌; 唐先贺

    2012-01-01

    In this paper, curing performance of low viscosity epoxy resin used in wind power blades at temperatures of 70 ℃, 90 ℃ and 110 ℃ was studied. Analysis by gas chromatography-mass spectrometry showed that low viscosity epoxy resin was mainly made up with bisphenol A epoxy resin and 1, 4-butanediol diglycidyl, and curing agent was polyamine-based. Analysis of 3 group samples at 70 ℃, 90℃ and 110 ℃ by infrared spectroscopy showed that the content of ether linkage which played a role in cured cross-linked network decreased with the increase of curing temperature, while the content of carbonyl and methylene increasing , These were described in the curing temperature range of curing temperature polymer crosslinking degree of downward trend. Property test on the sample of casting body of epoxy and fiberglass mechanical showed that when curing temperature rose from 70 ℃ to 110 ℃ , the sample's mechanical properties got weaker.%研究了风电叶片用低黏度环氧树脂在70℃、90℃和110℃固化温度下固化物的性能变化.气相色谱-质谱分析低黏度环氧树脂主要由双酚A环氧树脂和1,4-丁二醇二缩水甘油醚组成,固化剂为多元胺的成分,再通过红外光谱对70℃、90℃和110℃3组样件进行分析,结果显示,随着固化温度升高,固化物中起到体型网络交联的醚键的含量呈下降趋势,同时羰基和亚甲基含量增加,这些都说明在此固化温度区间内,固化温度升高,高分子的交联度呈下降趋势.对环氧浇铸体和玻璃钢样件的力学性能测试显示,从70℃到110℃固化温度升高样件的各项力学性能呈下降趋势.

  17. Degradation Mechanism of Poly(Ether-Urethane) Estane Induced by High Energy Radiation (III) : Radiolytic Gases and Water Soluble Products

    International Nuclear Information System (INIS)

    Within the framework of nuclear waste management, there is interest in the prediction of long-term behaviour of organic materials subjected to high energy radiation. Once organic waste has been stored, gases and low molecular products might be generated from materials irradiated by radionuclides. Long-term behaviour of organic material in nuclear waste has several common concerns with radiation ageing of polymers. But a more detailed description of the chemical evolution is needed for nuclear waste management. In a first approach, an extensive work on radiation ageing is used to identify the different processes encountered during the degradation of a polyurethane, including oxidation dose rate-effects and influence of dose on the oxidation mechanism. In a second approach, a study is performed to identify and quantify gases and possible production of water soluble chemical complexing agents which might enhance radionuclides migration away from the repository. In this work, we present results concerning the production of radiolytic gases and the formation of water soluble oligomers reached with leaching tests Films were made from a poly(ether-urethane) synthesized from methylene bis(p-phenyl isocyanate) (MDI) and poly(tetramethylene glycol) (PTMG) with 1,4 butanediol (BD) and were irradiated by high-energy electron beam to cover a wide doses range and by γ rays to determine the formation/consumption yields of gases. They were measured by mass spectrometry and gas-chromatography/mass spectrometry (GC/MS). The migration of water soluble oligomers in water was reached by measuring the weight loss versus leaching time. The identification of oligomers was performed by using a mass spectrometry with an electrospray ionisation interface (ESI-MS-MS). The analysis of radiolytic gases indicates the formation of H2, CO2 and CO with respective radiolytic yields of 1, 0.5 and 0.3 molecule/100 eV. The consumption of O2 is evaluated to 6 molecules/100 eV. For absorbed doses higher

  18. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen-Jie; Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by {sup 1}H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t{sub 1/2}, Z{sub c} and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. - Highlights: • The incorporation of NPGS units reduced the spherulite size of BS unit. • The existence of NPGS units did not change the crystal structure of BS unit. • The NPGS units incorporated in PBS could significantly improve the ductility of

  19. GHB pharmacology and toxicology: acute intoxication, concentrations in blood and urine in forensic cases and treatment of the withdrawal syndrome.

    Science.gov (United States)

    Busardò, Francesco P; Jones, Alan W

    2015-01-01

    The illicit recreational drug of abuse, γ-hydroxybutyrate (GHB) is a potent central nervous system depressant and is often encountered during forensic investigations of living and deceased persons. The sodium salt of GHB is registered as a therapeutic agent (Xyrem®), approved in some countries for the treatment of narcolepsy-associated cataplexy and (Alcover®) is an adjuvant medication for detoxification and withdrawal in alcoholics. Trace amounts of GHB are produced endogenously (0.5-1.0 mg/L) in various tissues, including the brain, where it functions as both a precursor and a metabolite of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). Available information indicates that GHB serves as a neurotransmitter or neuromodulator in the GABAergic system, especially via binding to the GABA-B receptor subtype. Although GHB is listed as a controlled substance in many countries abuse still continues, owing to the availability of precursor drugs, γ-butyrolactone (GBL) and 1,4-butanediol (BD), which are not regulated. After ingestion both GBL and BD are rapidly converted into GHB (t½ ~1 min). The Cmax occurs after 20-40 min and GHB is then eliminated from plasma with a half-life of 30-50 min. Only about 1-5% of the dose of GHB is recoverable in urine and the window of detection is relatively short (3-10 h). This calls for expeditious sampling when evidence of drug use and/or abuse is required in forensic casework. The recreational dose of GHB is not easy to estimate and a concentration in plasma of ~100 mg/L produces euphoria and disinhibition, whereas 500 mg/L might cause death from cardiorespiratory depression. Effective antidotes to reverse the sedative and intoxicating effects of GHB do not exist. The poisoned patients require supportive care, vital signs should be monitored and the airways kept clear in case of emesis. After prolonged regular use of GHB tolerance and dependence develop and abrupt cessation of drug use leads to unpleasant

  20. STUDY ON INDUCING MINERALIZATION OF POLYLACTIDE CONTAINING PHOSPHORYLCHOLINE%含磷脂酰胆碱的聚乳酸的诱导矿化研究

    Institute of Scientific and Technical Information of China (English)

    邱永兵; 仇植; 陈元维; 罗祥林

    2012-01-01

    Polylactide containing phosphorylcholine (PLA-PC) and polylactide (PLA) were synthesized with lactide (LA) as monomer,glycerophosphorylcholine and 1,4-butanediol as ring-opening initiators respectively. The comparison investigation of inducing mineralization on PLA-PC and PLA films was conducted. The result demonstrated that mineralized products could form on the film of PLA-PC as well as on the film of PLA in the simulated body fluid (SBF) of pH 6. 8. Moreover, formation of the mineralized products was easier on the film of PLA-PC than on the film of PLA. The reason for that is phosphorylcholines can migrate to the surfaces of polymers when PLA-PC contacts with water, and PLA-PC can combine with more Ca + than PLA because phosphoryl in PLA-PC can combine with Ca2+ owing to the interaction between negative charge and positive charge. Fourier-transform infrared ( FTIR) , X-ray diffraction ( XRD ) and scanning electron microscopy (SEM) were used to characterize the mineralized products formed on the surface of PLA-PC films. The results showed that the mineral crystal was hydroxylapatite (HAP) and the crystal had a laminated structure. PLA-PC films are good for nucleation and development of crystals. The crystalline grains and crystalline thickness grew with increasing mineralization time. Therefore, PLA-PC is a promising biodegradable scaffolds material for bone tissue engineering.%分别以甘油磷脂酰胆碱和1,4-丁二醇为引发剂开环丙交酯,制备了含磷脂酰胆碱的聚乳酸(PLAPC)和聚乳酸(PLA),比较了两者在诱导矿化中的差异.用傅立叶红外光谱仪(FTIR)、X-射线衍射仪(XRD)和扫描电子显微镜(SEM)对PLA-PC膜表面形成的矿化物进行了表征,结果表明,形成的矿化物为羟基磷灰石(HAP),PLA-PC膜有利于成核和生长,晶体呈片状,并随矿化时间延长,HAP晶粒逐渐增大,晶片厚度也逐渐变大.

  1. 阳离子全氟烷基水性聚氨酯涂膜表面性能的研究%Study on the surface properties of membrane of cationic perfluoroalkyl waterborne polyurethane

    Institute of Scientific and Technical Information of China (English)

    李培枝; 沈一丁; 杨晓武

    2011-01-01

    以异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃二醇(PTMG1000)、N-甲基二乙醇胺(MDEA)、1,4-丁二醇(BD0)、三羟甲基丙烷(TMP)等为主要原料,采用全氟乙基辛醇(FEOH)封端改性,制备了含全氟烷基侧链的阳离子含氟水性聚氨酯.通过红外光谱(IR)对聚合物结构进行了表征,测量了涂膜与水和乙二醇的接触角,用表面电子能谱仪(ESCA)检测了聚氨酯成膜后的含氟成分的分布情况,并考察了该涂膜的耐热性和耐蚀性能.研究发现,全氟烷基聚氨酯成膜时产生了较大取向作用,含氟基团向空气/聚合物界面伸展,有明显的"趋表"现象,这有利于形成低能表面,对聚合物内部分子形成了很好地保护作用,使涂膜具有较高的耐热性及优异的耐蚀性能.%Cationic waterborne fluorinated polyurethane (CFPU) containing perfluoroalkyl side chain was prepared by the reaction of isophorone isocyanate (IPDI), polyether polyol (PTMG1000), N-methyldiethanolamine (MDEA), 1,4-butanediol (BDO), trimethylol propane (TMP) and 2-(perfluorooctyl) ethyl alcohol (FEOH).The structure of the polymer was characterized by Fourier transform infared spectrometer (IR). And the contact angle of the membrane was measured, the distribution of the fluorinated group was examined in the surface of films with electron spectroscopy for chemical analysis (ESCA), then the heat resistance and corrosion resistance were also investigated. The results showed that during the process of casting membranes, the fluorinated group stretched on the interface of the air and the polymer, and had property of going to exterior, which could beneficial to form low energy surface and protect the inner molecule of the polymer effectively, and the films were provided with excellent heat and corrosion resistance properties.

  2. Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2012-12-01

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, {sup 1}HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T{sub m}), crystallization temperature (T{sub c}), and crystallinity (X{sub c}) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the {sup 1}H NMR spectra using the relative intensities of the proton peaks. As a sample, the {sup 1}H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH{sub 2}){sub 2}-CO; O-CH{sub 2}- and C-(CH{sub 2}){sub 2}-C from the SA and BD unit at {delta}2.59; {delta} 4.08 and {delta}1.67; O-(CH{sub 2}CH{sub 2}){sub n}-O from the PEG unit at {delta} 3.61. The molar composition of polyester copolymer was measured as the area ratio of {delta}3.61/({delta}4.08 + {delta}1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: Black-Right-Pointing-Pointer The introduction of PEG unit changed the flexibility of PBS main chain. Black-Right-Pointing-Pointer PEG unit did not alter the crystal form of PBS in copolymers. Black-Right-Pointing-Pointer PEG unit hindered the formation of ring-banded spherulite morphology in copolymers

  3. A hydrophilic polyurethane material with good blood compatibility%一种血液相容性良好的亲水性聚氨酯材料

    Institute of Scientific and Technical Information of China (English)

    鲁金; 周慧娟; 史惠婷; 钱羽锋; 贺春丽; 梁存霞; 李利

    2011-01-01

    BACKGROUND: When polyurethane materials are in contacwith living organisms, they can cause adverse biological reasons,for example, forming thrombus and inflammation.OBJECTIVE: To improve the hydrophilioity of polyurethane materials through a mixture of hydrophilic softs egments so as toobtain a polyurethane material with better anticoagulant properties.METHODS: Polyurethane films were synthesized with polvtetrahydr ofuran and polyethylene glycol as mixed s oft segments,4, 4'-diphenylmethane diisooyanate as the hard segment, and then in the chain extender I, 4-butanediol and the catalystdibutyltin dilaurate conditions to obtain a series of polyurethane materials.RESULTSAND CONCLUSION: The results showed that hydrophilic and blood compatibility properties of polyurethane filmswere enhanced, with the increase of the content of polyethylene glycol.%背景:当聚氨酯材料与活体组织相接触时,会导致一些不良反应,诸如血栓形成和炎症反应.目的:通过混合亲水性软段来改善聚氨酯材料的亲水性,从而制得抗凝血性能较好的聚氨酯材料.方法:以聚四氢呋喃、聚乙二醇作为混合软段,4,4'-二苯基甲烷二异氰酸酯为硬段,然后在扩链剂1,4-丁二醇以及催化剂二丁基二月桂酸锡的条件下以预聚法合成一系列聚氨酯材料.结果与结论:增加聚乙二醇的含量,聚氨酯材料的亲水性提高.软段中含有聚乙二醇的聚氨酯材料依然能够保持聚氨酯材料优良的机械性能,血小板黏附较少,抗凝血性较好.提示通过在聚氨酯合成原料的软段中添加聚乙二醇,可以提高聚氨酯材料的亲水性和血液相容性.

  4. Biodegradability of unsaturated aliphatic polyesters prepared from fumaric acid%以反丁烯二酸合成的不饱和脂肪族聚酯的生物降解性研究

    Institute of Scientific and Technical Information of China (English)

    杨群; 陆大年; 崔进

    2013-01-01

    Unsaturated aliphatic polyesters and copolyesters were prepared from fumaric acid (FA) , dieth-ylene glycol (DEG) and 1,4-butanediol (BD) by melt poly condensation method. Enzymatic degradation was performed at 37 ℃ in phosphate buffer solution with porcine pancreas lipase, effect of structures, compositions and cross-linking degrees of carbon-carbon double bonds of polyesters on the biodegradability were discussed. The results indicated that, as the C=C double bond introduced into the backbone of solid polyesters, Tm value and crystallinity increased. The degradability of aliphatic polyesters by lipases depended strongly on their Tm values and crystallinity, the higher the Tm and crystallinity, the lower the degradability . The result also indicated that the thermal properties ( Tm value and - △Hm value) and crystallinity of polyesters increased after partially enzymatic degradation, the biodegradation of unsaturated aliphatic polyester became smaller after cross-linked, and the higher the cross-linking degree, the smaller the biodegradation.%以反丁烯二酸、一缩二乙二醇和1,4-丁二醇为原料,采用熔融缩聚法合成了不饱和脂肪族聚酯和共聚酯,在37℃下,用含有脂肪酶的磷酸缓冲溶液对聚酯的生物降解性进行了研究,讨论了聚酯结构、组成及C=C双键的交联度对生物降解性的影响.结果表明,对于粘稠液体状的聚酯,C=C双键的引入,没有明显的改变其生物降解性;对于固体状的聚酯,C=C双键引入后,熔点(Tm)和结晶度增加;聚酯部分降解后,其热力学性能(Tm、-△Hm)和结晶度都升高;对于交联后的聚酯,交联度越高,生物降解性越差.

  5. Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

    International Nuclear Information System (INIS)

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, 1HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (Tm), crystallization temperature (Tc), and crystallinity (Xc) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the 1H NMR spectra using the relative intensities of the proton peaks. As a sample, the 1H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH2)2-CO; O-CH2- and C-(CH2)2-C from the SA and BD unit at δ2.59; δ 4.08 and δ1.67; O-(CH2CH2)n-O from the PEG unit at δ 3.61. The molar composition of polyester copolymer was measured as the area ratio of δ3.61/(δ4.08 + δ1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: ► The introduction of PEG unit changed the flexibility of PBS main chain. ► PEG unit did not alter the crystal form of PBS in copolymers. ► PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. ► The copolyesters had good in vitro degradation performance. ► The composition ratio of PEG unit can adjust the in vitro degradation performance.

  6. Evaluating the potential of poly(beta-amino ester nanoparticles for reprogramming human fibroblasts to become induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Bhise NS

    2013-12-01

    Full Text Available Nupura S Bhise,1,* Karl J Wahlin,2,* Donald J Zack,2–4 Jordan J Green1,21Department of Biomedical Engineering, Translational Tissue Engineering Center, and Institute for Nanobiotechnology, 2Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, MD, 3Solomon H Snyder Department of Neuroscience, Department of Molecular Biology and Genetics, and Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; 4Institut de la Vision, Paris, France*These authors contributed equally to this workBackground: Gene delivery can potentially be used as a therapeutic for treating genetic diseases, including neurodegenerative diseases, as well as an enabling technology for regenerative medicine. A central challenge in many gene delivery applications is having a safe and effective delivery method. We evaluated the use of a biodegradable poly(beta-amino ester nanoparticle-based nonviral protocol and compared this with an electroporation-based approach to deliver episomal plasmids encoding reprogramming factors for generation of human induced pluripotent stem cells (hiPSCs from human fibroblasts.Methods: A polymer library was screened to identify the polymers most promising for gene delivery to human fibroblasts. Feeder-independent culturing protocols were developed for nanoparticle-based and electroporation-based reprogramming. The cells reprogrammed by both polymeric nanoparticle-based and electroporation-based nonviral methods were characterized by analysis of pluripotency markers and karyotypic stability. The hiPSC-like cells were further differentiated toward the neural lineage to test their potential for neurodegenerative retinal disease modeling.Results: 1-(3-aminopropyl-4-methylpiperazine end-terminated poly(1,4-butanediol diacrylate-co-4-amino-1-butanol polymer (B4S4E7 self-assembled with plasmid DNA to form nanoparticles that were more effective than leading commercially available

  7. 基于酸性媒介黑T的水性聚氨酯染料的合成及成膜性能%Synthesis and cured film property of waterborne polyurethane dye based on eriochrome black T

    Institute of Scientific and Technical Information of China (English)

    胡先海; 张兴元; 戴家兵

    2011-01-01

    以甲苯二异氰酸酯(TDI)、聚氧化丙烯二醇、2,2-二羟甲基丙酸、酸性媒介黑T(EBT)或1,4-丁二醇(BDO)等为主要原料,经自乳化法分别合成制备出TDI型水性聚氨酯EBT-PU和BDO-PU.Fourier变换红外光谱分析证实了EBT-PU和BDO-pU的结构.研究发现由于EBT接入聚氨酯分子链时引起助色团-OH消失以及EBT中偶氮基生色团与萘环等整体共轭体系受到影响,528nm处的UV-vis吸收峰出现了44nm的红移.虽然EBT-PU和BDO-PU分子链中软硬段都不相容,但EBT共轭结构较BDO的脂肪链结构对软硬段不相容性影响更大.实验证实EBT-PU染料是一非晶聚合物,EBT的共轭结构可使EBT-PU热稳定性得到明显改善.%A noval waterborne polyurethane dye EBT-PU and a reference BDO-PU were synthesized using toluene diisocyanate, polyoxypropylene glycol,2,2-dimethylol propionic acid and eriochrome black T (EBT) or 1,4butanediol (BDO) by self-emulsification method. The structure of EBT-PU and BDO-PU was confirmed by Fourier transform infrared spectroscopy. It was found that the maximum absorption of 528nm in UV-Visible spectrum appeared a bathochromic shift of 44nm because of the disappearance of auxochrome -OH and the change of conjugate system for EBT during the reaction between EBT and -NCO group. Although the soft and hard segments in chains of EBT-PU and BDO-PU are incompatible, the conjugate structure of EBT has a big effect on the incompatibility comparing to the aliphatic chain of BDO. The experimental result shows that EBT-PU is an amorphous polymer,and the conjugate structure of EBT can introduce a distinct improve for the thermal stability of EBT-PU.

  8. Industrial Acetogenic Biocatalysts: A Comparative Metabolic and Genomic Analysis

    Science.gov (United States)

    Bengelsdorf, Frank R.; Poehlein, Anja; Linder, Sonja; Erz, Catarina; Hummel, Tim; Hoffmeister, Sabrina; Daniel, Rolf; Dürre, Peter

    2016-01-01

    Synthesis gas (syngas) fermentation by anaerobic acetogenic bacteria employing the Wood–Ljungdahl pathway is a bioprocess for production of biofuels and biocommodities. The major fermentation products of the most relevant biocatalytic strains (Clostridium ljungdahlii, C. autoethanogenum, C. ragsdalei, and C. coskatii) are acetic acid and ethanol. A comparative metabolic and genomic analysis using the mentioned biocatalysts might offer targets for metabolic engineering and thus improve the production of compounds apart from ethanol. Autotrophic growth and product formation of the four wild type (WT) strains were compared in uncontrolled batch experiments. The genomes of C. ragsdalei and C. coskatii were sequenced and the genome sequences of all four biocatalytic strains analyzed in comparative manner. Growth and product spectra (acetate, ethanol, 2,3-butanediol) of C. autoethanogenum, C. ljungdahlii, and C. ragsdalei were rather similar. In contrast, C. coskatii produced significantly less ethanol and its genome sequence lacks two genes encoding aldehyde:ferredoxin oxidoreductases (AOR). Comparative genome sequence analysis of the four WT strains revealed high average nucleotide identity (ANI) of C. ljungdahlii and C. autoethanogenum (99.3%) and C. coskatii (98.3%). In contrast, C. ljungdahlii WT and C. ragsdalei WT showed an ANI-based similarity of only 95.8%. Additionally, recombinant C. ljungdahlii strains were constructed that harbor an artificial acetone synthesis operon (ASO) consisting of the following genes: adc, ctfA, ctfB, and thlA (encoding acetoacetate decarboxylase, acetoacetyl-CoA:acetate/butyrate:CoA-transferase subunits A and B, and thiolase) under the control of thlA promoter (PthlA) from C. acetobutylicum or native pta-ack promoter (Ppta-ack) from C. ljungdahlii. Respective recombinant strains produced 2-propanol rather than acetone, due to the presence of a NADPH-dependent primary-secondary alcohol dehydrogenase that converts acetone to 2

  9. Comparative genomic analysis of single-molecule sequencing and hybrid approaches for finishing the Clostridium autoethanogenum JA1-1 strain DSM 10061 genome

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D [ORNL; Nagaraju, Shilpa [LanzaTech; Utturkar, Sagar M [ORNL; De Tissera, Sashini [LanzaTech; Segovia, Simón [LanzaTech; Mitchell, Wayne [LanzaTech; Land, Miriam L [ORNL; Dassanayake, Asela [LanzaTech; Köpke, Michael [LanzaTech

    2014-01-01

    Background Clostridium autoethanogenum strain JA1-1 (DSM 10061) is an acetogen capable of fermenting CO, CO2 and H2 (e.g. from syngas or waste gases) into biofuel ethanol and commodity chemicals such as 2,3-butanediol. A draft genome sequence consisting of 100 contigs has been published. Results A closed, high-quality genome sequence for C. autoethanogenum DSM10061 was generated using only the latest single-molecule DNA sequencing technology and without the need for manual finishing. It is assigned to the most complex genome classification based upon genome features such as repeats, prophage, nine copies of the rRNA gene operons. It has a low G + C content of 31.1%. Illumina, 454, Illumina/454 hybrid assemblies were generated and then compared to the draft and PacBio assemblies using summary statistics, CGAL, QUAST and REAPR bioinformatics tools and comparative genomic approaches. Assemblies based upon shorter read DNA technologies were confounded by the large number repeats and their size, which in the case of the rRNA gene operons were ~5 kb. CRISPR (Clustered Regularly Interspaced Short Paloindromic Repeats) systems among biotechnologically relevant Clostridia were classified and related to plasmid content and prophages. Potential associations between plasmid content and CRISPR systems may have implications for historical industrial scale Acetone-Butanol-Ethanol (ABE) fermentation failures and future large scale bacterial fermentations. While C. autoethanogenum contains an active CRISPR system, no such system is present in the closely related Clostridium ljungdahlii DSM 13528. A common prophage inserted into the Arg-tRNA shared between the strains suggests a common ancestor. However, C. ljungdahlii contains several additional putative prophages and it has more than double the amount of prophage DNA compared to C. autoethanogenum. Other differences include important metabolic genes for central metabolism (as an additional hydrogenase and the absence of a

  10. Analysis of volatile compounds of salty spice powder on sufu%一种腐乳咸味香料粉挥发性成分分析

    Institute of Scientific and Technical Information of China (English)

    陈蓉; 劳文艳

    2013-01-01

    对一种自然发酵腐乳制成的腐乳粉进行挥发性成分分析,运用固相微萃取结合气—质联用技术,鉴定出其中主要挥发性风味物质共68种,包括醇类4种,酸类5种,酚类2种,酮类2种,酯类25种,烷烃类16种,杂环化合物14种.酯类物质在数量上最多,同时也是腐乳粉风味产生的主体物质.乙酸、2,3-丁二醇、丙二醇、三甲基吡嗪、亚油酸乙酯、2,3,5,6-四甲基吡嗪、油酸乙酯在检出的物质中含量较大,分别为30.22%,15.7%,5.25%,2.94%,2.71%,2.37%,1.96%,它们对腐乳粉风味的形成具有一定的贡献,多种香气成分的存在共同构成了腐乳粉独特的风味.%The article analyze volatile organic compounds of a sufu powder which made by traditional fermentation sufu adopting SPME extraction combined with GC-MS, using technology of searching literature to determine the relative content of its components by area normalization method, 68 species (seven categories) volatile flavor compounds of sufu powder were identified, these flavor compounds include alcohols(4), acids(5) , phenols(2), ketones(2), esters(25), Alkanes(16) and heterocyclics ( 14). The content of esters is the most, and esters constitute the main profile of the characteristic of sufu powder. The content of ingredients such as ethanoic acid, 2,3-butanediol, propylene glycol, trimethylpyrazine, linoleic acid ethyl ester, 2,3,5,6 - tetramethylpyrazine, ethyl oleate were higher in sufu powder, and were 30. 22%, 15. 7%, 5. 25%, 2.94%, 2.71%, 2. 37% and 1. 96% ,respectively, play a certain contribution to flavor formation of sufu powder,the existence of various flavour compounds collectively constitute the unique flavor of sufu powder.

  11. 气相色谱-质谱联用法分析苹果酒香气成分的研究%Analysis of aromatic components in cider by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    彭帮柱; 岳田利; 袁亚宏; 王云阳; 高振鹏

    2006-01-01

    采用溶液萃取法提取并浓缩苹果酒中的香气成分,然后利用气相色谱-质谱联用法(GC-MS)对苹果酒香气成分进行鉴定分析.结果表明,共分离得出44种香气成分,鉴定出了40种香气的化学成分,约占色谱流出组分总峰面积的98.7%,其中苹果酒香气成分中相对含量较高的高级醇类有2-甲基-1-丁醇(2-Methyl-1-butanol,48.19%)、2,3-丁二醇(2,3-Butanediol,13.19%+4.06%)、苯乙醇(Benzene ethanol,12.61%)、3-呋喃乙醇(3-Fluranm ethanol,1.97%)、4-羟基苯乙醇(4-Hydroxy-benzene ethanol,0.96%)和2,3-二辛醇(2,3-Octanediol,0.55%)等;酯类有丁二酸单乙酯(Ethyl hydrogensuccinate,4.29%)、软脂酸乙酯(Ethyl palmitoate,1.84%)、辛酸乙酯(Octanoic acid,ethyl ester,0.43%)、己酸乙酯(Hexanoic acid,ethylester,0.37%)、乙酸-2-苯乙酯(Acetic acid,2-phenylethylester,0.23%)、癸酸乙酯(Ethyl decanoate,0.12%)和乙酸乙酯(Ethyl acetate,1.08%)等;脂肪酸类主要有癸酸(Decanoic acid,1.05%)、丁酸(Butenoic acid,0.55%)和己酸(Hexanoic acid,0.88%)等,这与其他的研究报道有异同之处.本试验还发现,苹果酒香气成分中含有较多的2-甲基-1-丁醇和丁二酸单乙酯.

  12. 端羟基聚乳酸低聚物的制备与性能研究%Preparation and Properties of Hydroxyl Terminated Polylactic Acid Oligomer

    Institute of Scientific and Technical Information of China (English)

    张苗苗; 常军; 杨超; 张恒; 许贺

    2015-01-01

    以左旋乳酸和1,4-丁二醇为原料,氯化亚锡(SnCl2・2H2O)和辛酸亚锡(Sn(OCT)2)为催化剂通过熔融缩聚法合成端羟基聚乳酸(HO-PLLA-OH)。熔融缩聚反应工艺条件为:0.1%SnCl2・2H2O(mol%)和0.1%Sn(OCt)2(mol%),聚合温度控制在180℃,反应时间为10 h,并采用红外光谱(IR)、核磁共振谱(1H-NMR),测得产物黏均分子量(Mη)为9528,差示扫描热分析( DSC)等手段对聚合物的热性能进行了研究。低聚物在缓冲液中20天失重率为43.1%。%L-lactic acid and 1,4-butanediol were used to synthesize hydroxyl terminated PLLA( HO-PLLA-OH) by melt polycondensation with stannous chloride and stannous octoate as catalyst.The polymerization conditions was attributed as follows:the dose of SnCl2・ 2H2 O and Sn(OCT)2 reached 0.1%, polymerization temperature was 180℃, polymerization time was 10 h.The synthesized HO-PLLA-OH was detected by infrared spectroscopy ( IR) and proton nuclear magnetic resonance (1H-NMR).The viscosity-average molecular weight was exceeded 9528 detected by ubbelohde viscometer, and the thermal perproty was investigated by differential scanning calorimeter(DSC).Weight loss of HO-PLLA-OH was 43.1%in 20 days.

  13. Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; K.E. Duncan; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; Randy R. Simpson; N.Ravi; D. Nagle

    2005-08-15

    The project had three objectives: (1) to develop microbial strains with improved biosurfactant properties that use cost-effective nutrients, (2) to obtain biosurfactant strains with improved transport properties through sandstones, and (3) to determine the empirical relationship between surfactant concentration and interfacial tension and whether in situ reactions kinetics and biosurfactant concentration meets appropriate engineering design criteria. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns and Berea sandstone cores when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. Even low biosurfactant concentrations (16 mg/l) mobilized substantial amounts of residual hydrocarbon (29%). The bio-surfactant lowered IFT by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. A mathematical model that relates oil recovery to biosurfactant concentration was modified to include the stepwise changes in IFT as biosurfactant concentrations changes. This model adequately predicted the experimentally observed changes in IFT as a function of biosurfactant concentration. Theses data show that lipopeptide biosurfactant systems may be effective in removing hydrocarbon contamination sources in soils and aquifers and for the recovery of entrapped oil from low production oil reservoirs. Diverse microorganisms were screened for biosurfactant production and anaerobic

  14. Marché des catalyseurs d'hydrogénation The Market for Hydrogenation Catalysts

    Directory of Open Access Journals (Sweden)

    Mace J. M.

    2006-11-01

    Full Text Available L'institut Français du Pétrole (IFP ayant acquis une grande expérience dans le domaine des catalyseurs d'hydrogénation, en particulier dans l'utilisation du nickel soluble et des catalyseurs bimétalliques à base de palladium, une étude a été effectuée pour évaluer le marché potentiel des catalyseurs d'hydrogénation intervenant dans la synthèse de quelques grands intermédiaires pétrochimiques : le cyclohexane, la cyclohexanone, les alcools oxo, le butanediol, le sorbitol, le toluylène diamine, l'hexaméthylène diamine, l'eau oxygénée et l'acide téréphtalique. Ce marché atteint pour les produits considérés 63 M$ pour 3500 t/an de catalyseurs commercialisés et représente globalement 7 % de celui des catalyseurs utilisés en pétrochimie. Les débouchés les plus importants sont ceux des catalyseurs nécessaires pour la production de toluylène diamine (14,4×10·6 $, d'hexaméthylène diamine (11,5×10·6 $ et d'eau oxygénée (11,5×10·6 $. Ces hydrogénations sont effectuées pour l'essentiel en présence de 3 métaux: le nickel, 2300 t/an, le cuivre, 680 t/an et le palladium, 560 t/an. Le nickel continue d'être utilisé en majeure partie sous forme de nickel de Raney. Le nickel soluble de I'IFP, bien qu'étant plus sensible au soufre et à l'eau, devrait pouvoir trouver des applications pour l'hydrogénation d'autres composés possédant des doubles liaisons aromatiques. Les catalyseurs au palladium s'imposent lorsque l'on recherche une sélectivité dans l'hydrogénation d'une fonction sans toucher à une autre fonction. L'exemple type est, dans la préparation de l'eau oxygénée, celui de l'hydrogénation des fonctions quinone sans toucher aux liaisons aromatiques. On the basis of the great experience gained by Institut Français du Pétrole (IFP in the field of hydrogenation catalysts, especially in using soluble nickel and bimetallic palladium-base catalysts, a survey was made to assess the potential market for

  15. Evolution of the metabolic and regulatory networks associated with oxygen availability in two phytopathogenic enterobacteria

    Directory of Open Access Journals (Sweden)

    Babujee Lavanya

    2012-03-01

    Full Text Available Abstract Background Dickeya dadantii and Pectobacterium atrosepticum are phytopathogenic enterobacteria capable of facultative anaerobic growth in a wide range of O2 concentrations found in plant and natural environments. The transcriptional response to O2 remains under-explored for these and other phytopathogenic enterobacteria although it has been well characterized for animal-associated genera including Escherichia coli and Salmonella enterica. Knowledge of the extent of conservation of the transcriptional response across orthologous genes in more distantly related species is useful to identify rates and patterns of regulon evolution. Evolutionary events such as loss and acquisition of genes by lateral transfer events along each evolutionary branch results in lineage-specific genes, some of which may have been subsequently incorporated into the O2-responsive stimulon. Here we present a comparison of transcriptional profiles measured using densely tiled oligonucleotide arrays for two phytopathogens, Dickeya dadantii 3937 and Pectobacterium atrosepticum SCRI1043, grown to mid-log phase in MOPS minimal medium (0.1% glucose with and without O2. Results More than 7% of the genes of each phytopathogen are differentially expressed with greater than 3-fold changes under anaerobic conditions. In addition to anaerobic metabolism genes, the O2 responsive stimulon includes a variety of virulence and pathogenicity-genes. Few of these genes overlap with orthologous genes in the anaerobic stimulon of E. coli. We define these as the conserved core, in which the transcriptional pattern as well as genetic architecture are well preserved. This conserved core includes previously described anaerobic metabolic pathways such as fermentation. Other components of the anaerobic stimulon show variation in genetic content, genome architecture and regulation. Notably formate metabolism, nitrate/nitrite metabolism, and fermentative butanediol production, differ between E

  16. Study on moderate temperature curing epoxy resin with low viscosity%低粘度中温固化环氧树脂基体的研究

    Institute of Scientific and Technical Information of China (English)

    苏曹宁; 任明伟; 何琪; 范广宏; 陈蕴博

    2012-01-01

    采用环氧树脂E-51,稀释剂1,4-丁二醇二缩水甘油醚(622)和四氢邻苯二甲酸二缩水甘油酯(711),固化剂3-氨甲基-3,5,5-三甲基环己基胺(固化剂A)和仪-(2-氨甲基乙基)-w-(2-氨甲基乙氧基)聚[氧(甲基-1,2-亚乙基)](固化剂B)制备了4种环氧体系,通过粘度和力学性能测试及示差扫描量热分析对其加工性能、固化特性、耐热性及拉伸性能进行了研究。结果表明,当E-51,711,固化剂A和B的质量配比为95:5:12.05:17.10时,环氧体系综合性能最佳,30℃下初始粘度为0.4Pa·S,适用期为40min,固化后的拉伸强度为70MPa,断裂伸长率为6.1%,可用于湿法缠绕成型或液体模塑成型。%The four epoxy systems were prepared by using epoxy resin (E -51 ), diluent 1, 4 -butanediol diglyeidyl ether (622) or tetrahydrophthalie diglyeidyl ester (711) and curing agent 3 - aminomethyl - 3, 5, 5 - trimethylcyclohexylamine ( curing agent A) and alpha - ( 2 - Aminomethylethyl) - omega - ( 2 - aminomethylethoxy) - poly ( oxy ( methyl - 1, 2 - ethandiyl) ) ( curing agent B). The processing properties, curing characteristics, therreal properties and tensile properties of the four epoxy resins were investigated by the testings of viscosity and men- chanical property and DSC. The results showed that the system with the mass ratio of E -51, 711, curing agent A and B 95 : 5 : 12.05 : 17.10 had the best comprehensive properties. The initial viscosity and pot life of the system at 30 ℃ was 0. 4 Pa. s and 40 min, respectively. Tensile strength was 70 MPa and elongation at break was 6. 1%.The system could be used for wet winding or liquid molding molding.

  17. Microwave Synthesis of 3,3'-Bisazidomethyl Oxetane-3-Azidomethyl-3'-Methyl Oxetane Random Copolymer%微波合成3,3'-双叠氮甲基环氧丁烷-3-叠氮甲基-3'-甲基环氧丁烷无规共聚物

    Institute of Scientific and Technical Information of China (English)

    张弛; 李杰; 罗运军; 葛震

    2012-01-01

    3,3'-Bisbromomethyl oxetane-3-bromomethyl-3'-methyl oxetane(BBMO-BrMMO) random co-polymer was synthesized by cationic ring opening polymerization using 1,4-butanediol/boron trifluoride etherate initiator system.3,3'-Bisazidomethyl oxetane-3-azidomethyl-3'-methyl oxetane(BAMO-AMMO) random copolymer was then synthesized through microwave synthesis.Azidation kinetic analysis was car-ried out at the same time.The results indicate that composition and micro-sequential distribution of BBMO-BrMMO random copolymers are controllable through regulating molar feed ratio of monomers.Re-action rate of azidation is controlled by the amount of tetrabutyl ammonium bromide(TBAB),k=48.85 L/(moloh)(TBAB=1%);k=51.95 L/(moloh)(TBAB=5%);k=62.72 L/(moloh)(TBAB=10%).Reaction time of azidation is shortened by microwave synthesis,the security of the reaction process is improved ac-cordingly,and microwave synthesis does not change the chain structure of copolymers.%以1,4-丁二醇/三氟化硼·乙醚为引发体系,通过阳离子开环共聚合方法合成了3,3'-双溴甲基环氧丁烷-3-溴甲基-3'-甲基环氧丁烷(BBMO-BrMMO)无规共聚物,采用13CNMR进行了结构表征.然后用微波法对BBMO-BrMMO无规共聚物进行大分子叠氮化反应,合成了3,3'-双叠氮甲基环氧丁烷-3-叠氮甲基-3'-甲基环氧丁烷(BAMO-AMMO)无规共聚物,并对叠氮化反应动力学进行了研究.结果表明,BBMO-BrMMO无规共聚物的共聚组成和微观序列分布可以通过调节单体的物质的量配比实现可控性.叠氮化反应速率由相转移催化剂四丁基溴化铵(TBAB)的用量控制,反应速率常数为k=48.85L/(mol·h)(TBAB=1%);k=51.95L/(mol·h)(TBAB=5%);k=62.72L/(mol·h)(TBAB=10%).微波法缩短了叠氮化反应时间,提高了合成过程的安全性,并且未改变共聚物的链结构.

  18. Preparation of low-melting point copolyester bonding fiber from post-consumer polyester fabric by glycolysis%废旧涤纶织物醇解再生制备低熔点粘合纤维

    Institute of Scientific and Technical Information of China (English)

    钱军; 王少博; 邢喜全; 王朝生; 王方河; 王赛博; 林世东

    2016-01-01

    Polyethylene terephthalate ( PET) was recycled from post-consumer PET fabric by ethylene glycol glycolysis and was copolymerized with isophthalic acid and 1,4-butanediol as modified monomers during the chemical recycling process to produce a low-melting point copolyester ( LPET) .And a recycled low-melting point PET bonding fiber was prepared by using the recycled PET as the core and the recycled LPET as the sheath at a certain proportion via sheath -core composite spinning process prior to tensile post-processing .The results showed that the recycled PET had the similar thermal stability and the recycled LPET had the lower thermal stability than normal bright PET , giving no impact on the processing and application; the recycled LPET had the softening point of 76℃and the melting point of 125℃;the recycled low-melting point PET bonding fiber could be prepared with the linear density of 4.6 dtex, breaking strength 3.22 cN/dtex, elongation at break 48.2%, dry-hot shrinkage 5.6%, moisture regain 0.41%, perfectly satisfying the requirements of FZ/T 52010-2014 Recycled Polyester Staple Fiber , under the conditions as followed:sheath-core mass ratio 4:6, spinning temperature 280 ℃, quenching temperature 22 ℃, quenching speed 1.2 m/s,spinning speed 1 100 m/min, drawing bath temperature 60-65 ℃, draw ratio 2.9.%以废旧涤纶织物为原料,采用乙二醇醇解法对废旧涤纶织物进行化学再生,制得再生聚对苯二甲酸乙二醇酯(PET);在化学再生过程中以间苯二甲酸,1,4-丁二醇为改性单体进行共聚,制得再生低熔点共聚酯( LPET);采用皮芯复合纺丝工艺将再生LPET(皮)与再生PET(芯)按一定复合比例进行纺丝并进行拉伸后处理,制得再生低熔点PET粘合纤维。结果表明:与常规大有光PET比较,再生PET的热稳定性与之相近,再生LPET的热稳定性稍差,但不影响其加工应用;再生LPET的软化温度为76℃,熔融温度为125

  19. 一类磺酸系双子表面活性剂的制备及性能研究%Preparation and properties of a sulfonic acid series gemini surfactants

    Institute of Scientific and Technical Information of China (English)

    宋冬冬; 孙雪丽; 刘方圆; 朱广军

    2012-01-01

    Intermediates, α - sulfostearic acid and α - snlfolauric acid ,were prepared by reacting ehlorosulfonic acid with stearic acid and lauric acid respectively. Five kinds of sulfonic acid gemini surfactant were prepared by reacting α - sulfostearic acid with ethanediol ,1,4- butanediol ,1,6- hexanediol and poly ethanediol respectively as well as α — sulfolauric acid with ethanediol. All the sulfonated intermediates were neutralized to form the corresponding salts and thereby five kinds of sulfonic acid gemini surfactant were prepared. Molecular structures of the gemini surfactants were characterized by FTIR and HNMR. Optimal esterification reaction conditions for preparation of the gemini surfactants were obtained through orthogonal designed experiments. Basic physical - chemical properties of the gemini surfactants were studied. Results showed that following the increase of carbon chain length of the spacing group,its cmc reduces correspondingly. Meanwhile,following the increase of the carbon chain length of the hydrophobic group,its γcmc increases correspondingly. Emulsification and foam properties of the sulfonic acid series gemini surfactants are better than that of the corresponding single body sulfonic acid surfactants.%以氯磺酸为磺化剂,分别与硬脂酸和月桂酸进行磺化反应,制备了中间体α-磺基硬脂酸和α-磺基月桂酸.将中间体α-磺基硬脂酸分别与乙二醇、1,4-丁二醇、1,6-己二醇和聚乙二醇400以及α-磺基月桂酸与乙二醇进行酯化反应,最后中和成盐,制备出5种磺酸系双子表面活性剂.通过FTIR和1HNMR对目标产物进行了表征.通过正交试验对磺酸系双子表面活性剂制备的酯化工艺进行了优化,得到较优的酯化工艺条件.对制备的磺酸系双子表面活性剂的基本物化性能进行了研究,结果表明,临界胶束浓度(cmc)随联结基团长度的增加而降低,同时随着疏水链的增长,γcmc呈增大的

  20. DEVELOPMENT OF MICROORGANISMS WITH IMPROVED TRANSPORT AND BIOSURFACTANT ACTIVITY FOR ENHANCED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; D. Nagle

    2004-05-31

    .1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. When PHPA was used alone, about 10% of the residual oil was recovered. Interfacial tension (IFT) decreased in a stepwise manner as biosurfactant concentration increased with marked reductions in IFT occurring at biosurfactant concentrations of 10 and 40 mg/l. When the biosurfactant concentration was greater than 10 mg/l, residual oil recovery linearly increased with biosurfactant concentration. A mathematical model that relates oil recovery to biosurfactant concentration was modified to include the stepwise changes in IFT as biosurfactant concentrations changes. This model adequately predicted the experimentally observed changes in IFT as a function of biosurfactant concentration. Our work shows that (1) diverse microorganisms produce biosurfactants, (2) nutrient manipulation may provide a mechanism to increase biosurfactant activity, (3) biosurfactant concentrations in excess of the critical micelle concentration recover substantial amounts of residual oil, and (4) equations that describe the effect of the biosurfactant on IFT adequately predict residual oil recovery in sandstone cores.

  1. Analysis of GHB and Its Precursors in Urine and Their Forensic Application%尿液中γ-羟基丁酸及其前体物质的检测和应用

    Institute of Scientific and Technical Information of China (English)

    施妍; 崔小培; 向平; 沈保华

    2015-01-01

    目的:建立尿液中γ-羟基丁酸(gamma-hydroxybutyric acid,GHB)及其前体物质1,4-丁二醇(1,4-butanediol,1,4-BD)和γ-丁内酯(gamma-butyrolactone,GBL)的液相色谱-串联质谱法(LC-MS/MS),为相关案件提供依据。方法以GHB-d6、MOR-d3为内标,尿样经甲醇沉淀蛋白后通过液相色谱分离,电喷雾离子源进行离子化,多反应监测模式对各化合物进行检测。结果 GHB及其前体物质1,4-BD、GBL的检出限分别为0.1、0.1和2μg/mL,准确度为87.6%~98.1%,日内及日间精密度均小于15%,基质效应大于80%。结论所建立的分析方法灵敏度高、简便快速、专属性强、可靠性高,可为司法鉴定实践中涉及GHB的案件提供技术支持和基础数据。%Objective To establish the m ethod to analyze γ-hydroxybutyric acid (GHB ) and its precursors 1,4-butanediol (1,4-B D ) and gam m a-butyrolactone (GBL) in urine through LC-M S/M S and provide evi-dence for related cases. Methods GHB-d6 and M O R-d3 were used as the internal standard. The urine sam ple w as separated by LC after protein precipitation w ith m ethanol. The electrospray ion source w as for ionization. E ach com pound w as detected through m ultiple-reaction m onitoring (M R M ) m ode. Results The lim its of detection of GHB and its precursors 1,4-B D and GBLwere 0.1, 0.1 and 2μg/m L. The accuracy w as 87.6% -98.1% . The intra-day and inter-day precisions were less than 15% and m atrix ef-fects were higher than 80% . Conclusion The m ethod is high sensitive, sim ple, rapid, specific and w ith high reliability. This study has provided technical support and basic data for forensic cases involving GHB .

  2. 全氟烷基侧链改性阳离子水性聚氨酯的制备与应用%Preparation and Application of Cationic Waterborne Polyurethane Modified by Perfluoroalkyl Side Chain

    Institute of Scientific and Technical Information of China (English)

    王晨; 李小瑞; 李培枝; 杨晓武

    2011-01-01

    以异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃二醇(PTMGI000)、1,4-丁二醇(BDO)、N-甲基二乙醇胺(MDEA)、三羟甲基丙烷(TMP)等为主要原料,通过全氟乙基辛醇(FEOH)封端改性,制备了含全氟烷基侧链的阳离子含氟水性聚氨酯乳液.通过红外光谱( FTIR)、热重分析(TG)对其结构与膜性能进行了表征,并且将其作为纸张防水防油剂用于表面施胶,对处理后纸张表面的水和液体石蜡接触角及纤维形态进行了研究.结果表明,聚氨酯分子链中的全氟烷基成膜时产生了较大取向作用,含氟基团向空气/聚合物界面伸展,有明显的“趋表”现象,这有利于形成低能表面,对聚合物内部分子形成了很好的保护作用,使涂膜具有较高的耐热降解性能.当表面施胶质量分数为0.3%时,纸张即可达到优异的防水防油效果,水接触角达到134.7°,液体石蜡接触角达到119.2°.%Cationic fluorinated waterborne polyurethane (WCFPU) emulsion containing perfluoroalkyl side chain was prepared by the reaction of isophorone isocyanate ( IPDI ), polyether polyol (PTMG1000) ,N-methyldiethanolamine ( MDEA) , 1,4-butanediol ( BDO ) , trimethylol propane (TMP ) and modified by 2-( perfluorooctyl) ethyl alcohol ( FEOH). The structure of the polymer and the performance of the film were characterized by means of fourier transform infared spectrometer (IR) , thermogravimetric analysis (TGA). The cationic fluorinated waterborne polyurethane was applied as water- and oil-resistant agent in the film casting of paper processing; the contact angle of water and liquid paraffin and the fiber morphology of sized paper surface were also investigated. The results show that during the process of casting films, the fluorinated group stretched on the exterior interface of the air and the polymer, which was conducive to the formation of low energy surface and the effective protection of the inner molecules of the polymer, so that the films

  3. Preparation and Properties Study of Fluorine-Containing UV-Curing Polyurethane Elastomer%含氟聚氨酯弹性体的制备及性能研究∗

    Institute of Scientific and Technical Information of China (English)

    钟汶桂; 倪忠斌; 东为富; 陈明清

    2016-01-01

    A kind of UV⁃curing hydrophobic polyurethane elastomer was prepared by using isophorone diisocy⁃anate ( IPDI) , hydroxyl terminated polybutadiene ( HTPB) , fluorine containing diol, 1,4⁃butanediol ( BDO) and 2⁃hydroxyethyl acrylate ( HEA) as raw materials. The effects of content of the fluorinated diol on molecular weight, thermostability, hydrophobic property, water tolerance and mechanical strength were researched. The results showed that fluorinated diol was successfully introduced into the polyurethane chain segment. With the increase of the con⁃tent of fluorinated diol, the relative molecular weight of HFTPU gradually decreased and the molecular weight distri⁃bution increased gradually. With the fluorinated diol content was 8%, the thermal decomposition temperature was promoted from 295 ℃ to 340℃, the contact angle was also enhanced from 82�5° to 108�6°, water absorption was decreased from 5�1% to 1�6%, and the elongation at break and the rebound rate all increased obviously. The re⁃sults indicated that the incorporation of the fluorinated diol was useful for improvement of thermostability, hydropho⁃bic property, water tolerance and mechanical strength of polyurethane elastomer.%以异佛尔酮二异氰酸酯(IPDI)、端羟基聚丁二烯(HTPB)、氟代二醇、1,4⁃丁二醇(BDO)和丙烯酸羟乙酯( HEA)为原料,经多步反应合成了可紫外光固化的疏水性聚氨酯弹性体。考察了氟代二醇用量对聚氨酯弹性体的相对分子质量大小、耐热性、疏水性、耐水性、机械强度的影响。结果表明,氟代二醇被成功引入到聚氨酯链段中。随着氟代二醇含量增加,聚氨酯相对分子质量逐渐减小,相对分子质量分布逐渐变宽;当引入8%的氟代二醇,所得聚氨酯弹性体的热分解温度从295℃升高到340℃,膜表面的接触角从82�5°上升到108�6°,吸水率从5�1%下降到1�6%,断裂伸长率及

  4. 龙眼果酒品质及香气成分的GC-M S分析%Analysis of the Quality and the Flavoring Components of Longan Wine by GC-MS

    Institute of Scientific and Technical Information of China (English)

    邱松山; 王彦安; 黄可怡; 姜翠翠

    2015-01-01

    In order to analyze the sensory quality and the physiochemical indexes of longan wine comprehensively, in this study, GC-MS was applied to determine the flavoring components (extracted by methylene chloride and identified by database searching) in longan wine and their relative content (calculated by peak area normalization method). The results showed that, longan wine was superior in quality with golden yel-low color, bright and transparent wine body, its acidity (counted by tartaric acid) was 3.95 g/L, total sugar content (counted by glucose) was 3.48 g/L, soluble solids content was 2.7%, the pH value was 3.62, the clarity was 56.7%and polyphenols content was 298.552 mg/L. 49 vola-tile compounds were identified in longan wine by GC-MS including 8 kinds of alcohol, 12 kinds of esters, 10 kinds of acids, 7 kinds of ketones, 4 kinds of aldehydes, 5 kinds of heterocyclic compounds, 1 kind of acid anhydride, 1 kind of alkane and 1 kind of ethers. The main flavoring compounds were 2, 3-butanediol, phenylethyle alcohol, and ethyl acetat etc. Longan wine had rich aroma compounds and it had great market potentials.%为了进一步分析龙眼果酒的感官品质和理化指标,采用气相色谱-质谱联用技术(GC-MS)检测龙眼果酒的香气组分及其相对含量,为龙眼果酒的品质评价奠定基础。以龙眼酒为分析样品,评价分析其感官品质和理化指标,同时采用二氯甲烷萃取龙眼酒中的香气成分,气相色谱-质谱联用检测,数据库检索并用峰面积归一化法确定香气的化学成分及其相对含量。龙眼酒品质优良,色泽金黄、透明清亮、纯正爽怡,酒精度为7.9%vol、酸度(以酒石酸计)为3.95 g/L、总糖(以葡萄糖计)为3.48 g/L、可溶性固形物含量2.7%、pH3.62、澄清度为56.7%、色度为0.534、多酚含量为298.552 mg/L。利用GC-MS分析技术鉴定出龙眼酒中含有49种挥发性物质,其中醇类8种,酯类12种,酸类10

  5. 发酵葡萄干对面包烘焙特性及风味的影响%Influence of fermented raisins on the baking properties and volatile compound of bread

    Institute of Scientific and Technical Information of China (English)

    涂雅俊; 黄田苗; 赵宝; 杨哪; 徐学明

    2013-01-01

    研究发酵葡萄干添加量为3.33%、6.67%、10%对面包烘焙特性的影响.并应用固相微萃取技术(SPME)和气相色谱-质谱联用技术(GC-MS)研究分别添加3.33%葡萄干或发酵葡萄干的面包和普通面包之间挥发性风味物质的差异.结果表明:发酵葡萄干的添加可以抑制面包芯水分的迁移,添加量越大,面包水分迁移速率越小;添加量为3.33%时,对面包比容和硬度的影响最小,与普通面包之间无显著性差异(P<0.05).葡萄干发酵液面包含有甲乙酐、癸醛、2-甲基丁酸等12种独有的风味物质.2,3-丁二醇、糠醛、异戊酸、丙位庚内酯、反式-2,4-癸二烯醛、香叶基丙酮和丙位癸内酯共同存在于葡萄干面包与葡萄干发酵液面包中,而普通面包中未检出.%The influence of breads made with 3.33% ,6.67% and 10% of fermented raisins on the baking properties were analyzed in this paper,respectively.The difference between common breads and breads containing 3.33% of fermented raisins in composition of volatile compound were quantified using solid phase micro-extraction(SPME) and gas chromatography-mass spectrometry(GC-MS).The result indicated that adding fermented raisins could inhibit the moisture migration in crumb.The rate of moisture migration decreased with the amount of fermented raisins added.There was no significant difference between common breads and breads made with fermented raisins,when the added level of fermented raisins was 3.33% and its impact on bread specific volume and crumb firmness was smallest.12 kinds of volatile flavor compounds were only examined in bread made with fermented raisins,for example of decanal,2- methyl butyric acid and etc.2,3-butanediol, furfuraldehyde, isovaleric acid, heptanolide,trans-2,4-Decadienal,Geranylacetone and gamma-Decalactone were found both in breads made with raisins and the ones made with fermented raisins,but not in common breads.

  6. Structure-property relationships of flexible polyurethane foams

    Science.gov (United States)

    Aneja, Ashish

    segments to self-assemble and form lath-like percolated structures, resulting in solid plaques, even though the overall volume of the system was known to be dominated by the two terminal liquid-like polyether segments. In another aspect of this research, foams were investigated in which the ratios of the 2,4 and 2,6 TDI isomers were varied. The three commercially available TDI mixtures, i.e., 65:35 2,4/2,6 TDI, 80:20 2,4/2,6 TDI, and 100:0 2,4/2,6 TDI were used. These foams were shown to display marked differences in their cellular structure (SEM), urea aggregation behavior (TEM), and in the hydrogen bonding characteristics of the hard segments (FTIR). Finally, the nanoscale morphology of a series of 'model' segmented polyurethane elastomers, based on 1,4-butanediol extended piperazine based hard segments and poly(tetramethylene oxide) soft segments, was also investigated using AFM. The monodisperse hard segments of these 'model' polyurethanes contained precisely either one, two, three, or four repeating units. Not only did AFM image the microphase separated morphology of these polyurethanes, but it also revealed that the hard domains preferentially oriented with their long axis along the radial direction of the spherulites which they formed.

  7. 可降解聚酯酰胺共聚物的合成及其性能研究%The synthesis and performance of biodegradable polyester amide copolymer

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 冯正洋; 戴红; 石璞

    2015-01-01

    以丁二酸、丁二醇、1,6-己二胺为原料,二丁基二月桂酸锡为催化剂,甲苯二异氰酸酯(TDI)为扩链剂,通过熔融共聚,合成了 M w为40~65 k 的聚丁二酸-丁二醇-1,6-己二胺共聚物,并采用压延成膜法制得聚酯酰胺薄膜.研究了1,6-己二胺含量对聚酯酰胺的热性能、结晶性能、降解性能和流变性能的影响.结果表明,合成了聚酯酰胺,其熔点达到100.97℃,热分解温度为317.85℃;随着1,6-己二胺添加量增加,聚酯酰胺的拉伸强度不断变大,断裂伸长率略有下降;1,6-己二胺的加入并未改变聚酯酰胺的晶型,但降低了其结晶度;1,6-己二胺的加入提高了聚酯酰胺降解性能,而且改善了其流变性能,这有利于聚酯酰胺的成型加工和应用.%Succinic acid-butanediol-1,6-hexamethylenediamine polyester amide copolymers with Mw from 40 000 to 65 000 were synthesized by succinic acid,1,4-butylene and 1,6-hexamethylenediamine,through high temper-ature melt reaction.Meanwhile,the second dibutyl tin laurate was selected as catalyst,and the toluene disocya-nate (TDI)was selected as chain extender.The succinic acid-butylene-adipic amine copolymer films were pre-pared by calendering film-forming method.The influences of the content of 1,6-adipic amine on the copolymer performance of thermal,crystallization,degradation and rheological properties were researched.The results showed that the polyester amide copolymers were synthesized successfully,whose melting point is 100.97 ℃and the thermal decomposition temperature is 317.85 ℃.With the increasing of 1,6-adipic amine,the tensile strength of copolymers increased accordingly,and the elongation at break decreased slightly.1,6-adipic amine did not change the crystal type of copolymer,but the crystallinity of copolymer decreased.With adding the 1,6-adipic amine in copolymer,the degradation performance and rheological properties of the copolymers were im-proved,which is useful for the

  8. Evaluation on the effect of the poly (butylenes succinate) biodegradation process on plant growth%聚丁二酸丁二醇酯(PBS)生物降解过程对植物生长的影响评价

    Institute of Scientific and Technical Information of China (English)

    李成涛; 张敏; 欧阳亮; 刘俊玲; 苏康宇; 邱建辉

    2011-01-01

    通过苏丹草(Sorghum sudanense Stapf)、籽粒笕(Amaranthus hypochondriacus L.)、豇豆(Vigna sesquipedalis Wight)种子的发芽试验及其盆栽试验,考察了PBS在土壤浸提液中的生物降解性能,探讨了PBS高聚物、低聚物和合成单体对植物的发芽和生长影响.研究结果表明:①在土壤浸提液中微生物对PBS有一定的降解作用,且在降解过程中,降解液的pH变化不明显;②PBS高聚物的降解产物对植物生长没有影响;③PBS低聚物在降解初期抑制部分植物的幼苗生长,后期对植物的生长没有影响;④当丁二酸的质量浓度低于200 mg·L-1时,对植物种子的发芽和幼苗生长不会产生影响,当质量浓度高于500mg·L-1时,将抑制幼苗生长;当1,4-丁二醇的质量浓度低于2 000mg·L-1时,对种子的发芽和生长没有影响.%In this paper, we have do experiment of the seed germination and plant growth such as Sudan grass, Purple grainjian and cowpea to investigate the degradation of PBS in the soil extract liquid, discuss the effect of polymers, oligomers and monomers of PBS on the germination and growth of plants. The results show that: ①Microorganisms in the soil extract liquid can degrade PBS and the pH of the degradation liquid did not change significantly. ②The degradation progress of polymer has no effect on the plant growth. ③The degradation products of PBS oligomers inhibit the growth of some seedlings in initial stages, but have no effect in later stage. ④When the succinate concentration is lower than 200 mg·L-1, it has no effect to the plant seed germination and seedling growth, but when it is higher than 500 mg·L-1, it will inhibit the seedling growth. When the 1, 4 - butanediol concentration is less than 2 000 mg·L-1, it has no effect to the seed germination and growth.

  9. Catalytic Effects Comparison of Several Catalysts Used to Synthesize Poly (Butylene Succinate)%几种合成聚丁二酸丁二酯用催化剂的催化效果比较

    Institute of Scientific and Technical Information of China (English)

    高艳; 赖仕全; 刘兴南; 岳莉; 赵雪飞

    2014-01-01

    Poly(butylene succinate) (PBS) was synthesized respectively from 1,4-succinic acid and 1,4-butanediol using SnCl2,Sn(Oct)2,ZnCl2,Zn(OAc)2,Sb2O3 or SO42-/ZrO2 as catalyst by direct melt polycondensation method. The catalytic effects of the 6 kinds of catalysts in the polymerization reaction of PBS were compared by measuring liquid yield in the esterification reaction stage,yield and properties of PBS,such as intrinsic viscosity,molecular weight and melting temperature. Taking SnCl2 as example, the structure and thermal stability of PBS synthesized by SnCl2 were studied with FTIR and TG. The results show that the synthesized product is hydroxyl-capped PBS. The 6 kinds of catalysts all can promote dehydration esterification reaction of 1,4-succinic acid and 1,4-butanedio. Except for Sn(Oct)2,several other catalysts can effectively reduce the formation of tetrahydrofuran by-product. Overall,the catalytic effects of stannum compound are best among these catalyst and when SnCl2 is used as catalyst,the yield, intrinsic viscosity,number average molecular weight and original melting temperature of the synthesized PBS are best and it’s decomposition temperature is 280℃. Taking molecular weight of PBS as index,the order of the catalytic effects of the 6 catalysts is SnCl2>Sn(Oct)2>Sb2O3>SO42-/ZrO2>ZnCl2>Zn(OAc)2.%以1,4-丁二酸和1,4-丁二醇为原料,分别以SnCl2,异辛酸亚锡[Sn(Oct)2],ZnCl2,乙酸锌[Zn(OAc)2], Sb2O3和SO42-/ZrO2固体超强酸为催化剂,采用直接熔融缩聚法合成了聚丁二酸丁二酯(PBS)。通过测试酯化反应阶段的出液量、PBS的收率及其特性黏度、数均分子量和熔融温度等性质,比较了6种催化剂在PBS聚合反应中的催化效果。以SnCl2为例,利用傅立叶变换红外光谱和热重分析研究了由其催化合成的PBS的结构和热稳定性能。结果表明,实验合成的产物为羟基封端PBS;6种催化剂都能促进1,4-丁二酸和1,4-丁二醇分子间

  10. 焦炉煤气-甲醇产业链延伸技术方案的经济分析%Economic evaluation of industrial chain extension solutions for coke oven gas to methanol and chemicals

    Institute of Scientific and Technical Information of China (English)

    易群; 吴彦丽; 范洋; 胡长淳; 褚琦; 冯杰; 李文英

    2014-01-01

    与煤制甲醇和天然气制甲醇工艺相比,焦炉煤气制甲醇不仅可以有效利用焦炉煤气中的氢,而且具有低成本的优势。在焦炉煤气制甲醇工艺基础上,文中提出了3种具有发展潜力的焦炉煤气综合利用方案:①气化煤气-焦炉煤气制甲醇生产方案;②焦炉煤气-乙炔-甲醇下游产品方案;③气化煤气-焦炉煤气-乙炔-甲醇下游产品方案。以200×104 t焦炭的生产规模分析了3种方案经济性,其毛利润分别为24.21亿元,18.92亿元和28.74亿元;内部收益率分别为28.29%、24.34%和27.11%。气化煤气-焦炉煤气-乙炔-甲醇下游产品方案充分发挥了规模效应和产品高附加值的特点,具有明显的经济优势;系统灵活性高,抵御市场风险能力强。%Production cost of methanol from abundant and cheap coke oven gas (COG) is about 800-1000 CNY·t-1 lower than that from coal or natural gas. With expansion of international methanol production capacity and production scale, methanol market competition becomes more intense and cost advantage of coke oven gas to methanol is reduced evidently. It is significant to improve technology and extend industrial chains to use coke oven gas and obtain maximal benefits on the basis of coke oven gas to methanol production. One technical solution is combining coke oven gas with coal gasified gas (CGG) to produce methanol. CH4/CO2 reforming technology is used to convert CO2+CH4 into H2+CO, and adjust H2/CO ratio of syngas in this scheme. With this scheme, methanol production can increase by 30%. Another option is to extend methanol industrial chain to obtain high-value-added downstream products, such as vinyl acetate, polyvinyl alcohol, and 1,4-butanediol. In this design, CH4 is separated from COG to make acetylene, which is used to synthesize methanol downstream products by methane partial oxidation technology. However, 0.07 billion m3 H2 surplus and small scale of methanol production

  11. HDI三聚体改性磺酸盐型高固含量水性聚氨酯的制备与性能研究%Synthesis and Properties of High Solid Content Sulphonated Waterborne Polyurethane Modified by HDI Trimer

    Institute of Scientific and Technical Information of China (English)

    孙雪娇; 夏正斌; 李伟; 曹高华; 张燕红; 李忠

    2013-01-01

    Sulphonated waterborne polyurethane emulsions with 50% solid-content were successfully synthesized by using poly(1,4-butanediol adipate)diol (PBA), isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) as the main raw materials, N-(2-aminoethyl)-amino ethane sulphonated sodium as hydrophilic chain extender, and HDI trimer (HT) as a modifier. The effects of the feeding method and the amount of HDI trimer on the latex particle size and distribution, Zeta potential and viscosity of waterborne polyurethane emulsions, and the water resistance, crystallinity and mechanical properties of the cast films of synthesized polyurethane were studied respectively by Malvern laser particle size analyzer, Brookfield viscometer, universal tensile machine, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H-NMR), X-ray diffraction analysis (XRD), differential scanning calorimetry analysis (DSC) and transmission electron microscopy (TEM). The results show that, with the increase of the amount of HDI trimer, the viscosity of waterborne polyurethane emulsion decreases, the average particle size and its distribution of latex particles increase, and the tensile strength and elongation at break of the cast films are increased firstly and then decreased. The introduction of the HDI trimer into the polyurethane chain destroys the arrangement regularity of the polyurethane soft segment, which results in a slightly lower film crystallinity. When the ratio of HDI trimer to IPDI is 1:3 (mass ratio), the synthesized polyurethane shows excellent performance, which has the emulsion particle size of 199.3 nm, Zeta potential of-42.7 mV, the film water absorption of 3.8%and the film relative crystallinity of 50.62%.%  以异氟尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)、聚己二酸1,4-丁二醇酯二醇(PBA)为主要原料,以乙二胺基乙磺酸钠(AAS)为亲水性扩链剂,以HDI三聚体(HT)为改性剂,制得了固含量

  12. Simultaneous Determination of 1,2-Propylene Glycol,Glycerol and Triethylene Glycol in Smokeless Tobacco Products by Gas Chromatography-Mass Spectrometry%GC/MS法同时检测无烟气烟草制品中的1,2-丙二醇、丙三醇和三甘醇

    Institute of Scientific and Technical Information of China (English)

    张杰; 李鹏; 孙世豪; 宋瑜冰; 谢剑平; 宗永立

    2011-01-01

    A gas chromatography-mass spectrometry (GC/MS) method under selected ion monitoring (SIM) mode was developed for the simultaneous determination of 1,2-propylene glycol, glycerol and triethylene glycol in smokeless tobacco products (STPs) by using 1 ,4-butanediol as an internal standard.Thirty STP samples were parallel tested by GC/MS/SIM and GC/FID, a CORESTA recommended method, and the results were compared.The results showed that; 1 ) The recoveries of 1,2-propylene glycol, glycerol and triethylene glycolranged from 89.3% to 100.3% with the limits of detection of 1.25 to 2.75 μg/g and RSDs of 1.16 % to 4.37%.2) The contents of 1 ,2-propylene glycol, glycerol, and triethylene glycol in the samples ranged from 0.011 to 40.817, 0.024 to 39.044, 0.012 to 0.099 mg/g, respectively.3) 1,2-propylene glycol in 13 samples and glycerol in 14 samples were detected, and their contents in 9 of the samples were accurately determinable, however, triethylene glycol was undetectable in all samples by GC/FID.4) 1 ,2-propylene glycol in 29 samples, glycerol in 28 samples and triethylene glycol in 21 samples were detected, their contents in 16, 25 and 11 of the samples could be accurately determined by GC/MS/SIM method, respectively.5) The Pearson correlation coefficients between the contents of 1,2-propylene glycol in 13 samples and glycerol in 9 samples determined by GC/FID and GC/MS/SIM were over 0.99 probable value less than significant level of 0.05 and paired test t value over significant level of 0.05.It was concluded that the target analytes in the samples determined by GC/MS/SIM agreed with those by GC/FID, however, GC/MS/SIM method was more sensitive and accurate.GC/MS/SIM method is more suitable for the qualitative and quantitative determination of 1 ,2-propylene glycol, glycerol, and triethylene glycol in smokeless tobacco products.%为了准确测定无烟气烟草制品中保润剂的含量,以1,4-丁二醇为内标建立了同时检测无烟气烟草制品中1

  13. 固相微萃取与气相色谱-质谱联用法对不同酒龄黄酒的微量风味分析与应用%Analysis and Application of Trace Compounds in Rice Wine by Solid-Phase Micro Etraction and Gas Chromatograph-Mass Spectrum

    Institute of Scientific and Technical Information of China (English)

    江伟; 兰玉倩; 黄毅; 薛洁; 张五九

    2011-01-01

    34 flavor compounds, including 8 alcohols, 14 esters, 4 aldehydes, 5 acids, 1 phenol, 1 lactone,and 1 heterocycle, were determined in rice wine by solid-phase micro extraction and gas chromatograph-mass spectrometer. The precisions of the method ranged from 4. 42% to 13.44%. The recoveries were 78.44% ~ 118.92% with the detection limits in the range of 0. 002 ~ 13.92 μg/L. All data above-mentioned demonstrated it was a good method. Rice wine with different ages determined by this method. The total content of flavor compounds ranged from 726. 233 mg/L to 1290. 769 mg/L. The main compounds in rice wine were alcohols, esters and aldehydes, accounting for 63.68% ~ 71.10% , 27.84% ~ 34.09% , lower than 2% , respectively. Compounds with high content in rice wine in order were β-phenylethanol, ethyl lactate, iso-pentyl alcohol, isobutanol, ethyl acetate, diethyl succinate, 2,3-butanediol and so on. The alcohols during aging decreased due to the oxidation, while the esters during the later aging increased because of the esterification and transesterification reaction. In addition, aldehydes during aging also increased by oxidation and maillard reaction. 5-methyl-2-furaldehyde, furfural and benzaldehyde increased by 10 ~ 40 times during aging demonstrated those three compounds could be used as aging indicators of rice wine.%通过固相微萃取-气相色谱-质谱联用法检测了黄酒中34种风味成分,即醇类8种、酯类14种、醛类4种、酸类5种、酚类1种、内酯类1种和杂环类1种,该法精密度为4.42%~13.44%,回收率为78.44%~118.92%,检出限为0.002~13.92μg/L,该法准确可靠、操作简便.利用该法检测了不同酒龄的黄酒,发现黄酒中所测的风味化合物含量总和为726.233~1290.769 mg/L-1,醇类、酯类和醛类是黄酒的主体香气,分别占风味化合物含量总和的63.68%~71.10%、27.84%~34.09%、<2%.黄酒中主要化合物依次为β-苯乙醇、乳酸乙酯、异

  14. Preparation and characterization of a new kind of firm/soft adjusted poly(D,L-lactic acid)-polyurethane%“刚/柔”可控的新型聚氨酯材料的制备与表征**

    Institute of Scientific and Technical Information of China (English)

    须建; 彭坤; 甘哓玲; 王易振; 段巧玲; 阮长顺; 孙姣霞

    2013-01-01

      BACKGROUND: Biodegradable polyurethane is a focus in the field of biomedical materials. Poly(D,L-lactic acid)-polyurethane has a broad prospect in the biomedical field. OBJECTIVE: To prepare a new poly(D,L-lactic acid)-polyurethane based on the molecular designing, using D,L-lactide, 1,6-hexamethylene di socyanate, 1,4-butanediol and 1,4-butanediamine. METHODS: The hydroxy-terminated poly(D,L-lactic acid) was synthesized by melt polymerization, and then1,6-hexamethylene di socyanate was added as a crosslinker to produce poly(D,L-lactic acid)-polyurethane. These products were characterized by Fourier transform infrared spectrometry, nuclear magnetic resonance spectrometer, thermogravimetry/differential thermal analyzer and Instron 1121 universal tester to explore the structures and performance. RESULTS AND CONCLUSION: The chemical structure of the products was consistent with the expected molecular structure. To adjust the proportion of reactants, we realized the control of the firm/soft transition degree (from 472% to 112% of the elongation at break) and firm/soft transition temperature (from 36.33 ℃ to 44.04 ℃ of the glass transition temperature). These findings indicate that the biodegradable poly(D,L-lactic acid)- polyurethane has thermosensitive effect, and its elongation at break and glass transition temperature can be control ed, which is the application foundation in the field of biomedical engineering.%  背景:生物可降解聚氨酯是生物医用材料领域研究的一个热点。基于聚乳酸的智能型聚聚氨在生物医学领域具有广阔的应用前景。目的:以D,L-丙交酯、1,6-六亚甲基二异氰酸酯、1,4-丁二醇和1,4-丁二胺作为原料,从分子设计角度出发,制备一种基于聚乳酸的“刚/柔”可控多嵌段聚氨酯材料。方法:采用熔融聚合法首先合成羟基封端聚(D,L-乳酸),加入六亚甲基二异氰酸酯作为交联剂,再聚合得到基于聚(D,L-

  15. Combustion characteristics of SMX and SMX based propellants

    Science.gov (United States)

    Reese, David A.

    This work investigates the combustion of the new solid nitrate ester 2,3-hydroxymethyl-2,3-dinitro-1,4-butanediol tetranitrate (SMX, C6H 8N6O16). SMX was synthesized for the first time in 2008. It has a melting point of 85 °C and oxygen balance of 0% to CO 2, allowing it to be used as an energetic additive or oxidizer in solid propellants. In addition to its neat combustion characteristics, this work also explores the use of SMX as a potential replacement for nitroglycerin (NG) in double base gun propellants and as a replacement for ammonium perchlorate in composite rocket propellants. The physical properties, sensitivity characteristics, and combustion behaviors of neat SMX were investigated. Its combustion is stable at pressures of up to at least 27.5 MPa (n = 0.81). The observed flame structure is nearly identical to that of other double base propellant ingredients, with a primary flame attached at the surface, a thick isothermal dark zone, and a luminous secondary flame wherein final recombination reactions occur. As a result, the burning rate and primary flame structure can be modeled using existing one-dimensional steady state techniques. A zero gas-phase activation energy approximation results in a good fit between modeled and observed behavior. Additionally, SMX was considered as a replacement for nitroglycerin in a double base propellant. Thermochemical calculations indicate improved performance when compared with the common double base propellant JA2 at SMX loadings above 40 wt-%. Also, since SMX is a room temperature solid, migration may be avoided. Like other nitrate esters, SMX is susceptible to decomposition over long-term storage due to the presence of excess acid in the crystals; the addition of stabilizers (e.g., derivatives of urea) during synthesis should be sufficient to prevent this. the addition of Both unplasticized and plasticized propellants were formulated. Thermal analysis of unplasticized propellant showed a distinct melt