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Sample records for butanediols

  1. 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.

  2. Optimization of 2,3-butanediol production in a bioreactor by Bacillus amyloliquefaciens

    OpenAIRE

    Manninen, Elina

    2015-01-01

    Due to the depleting fossil fuel reserves and the ever changing oil prices, the production of 2,3-butanediol has shifted towards more biological methods. Current studies are experimenting with various strains of bacteria and carbon sources to find the optimal production method. Finding the right balance in the production could make it possible to produce 2,3-butanediol in a larger scale. For this purpose, the production of 2,3-butanediol by the bacteria Bacillus amyloliquefaciens was optimize...

  3. Micro-organism for the production of stereo-specific s, s-2,3-butanediol

    DEFF Research Database (Denmark)

    2016-01-01

    The invention relates to a genetically modified lactic acid bacterium capable of producing (S,S)-2,3-butanediol stereo specifically from glucose under aerobic conditions. Additionally the invention relates to a method for producing (S,S)-2,3-butanediol and L-acetoin using the genetically modified...

  4. Production of 2,3-butanediol in Saccharomyces cerevisiae by in silico aided metabolic engineering

    Directory of Open Access Journals (Sweden)

    Ng Chiam Yu

    2012-05-01

    Full Text Available Abstract Background 2,3-Butanediol is a chemical compound of increasing interest due to its wide applications. It can be synthesized via mixed acid fermentation of pathogenic bacteria such as Enterobacter aerogenes and Klebsiella oxytoca. The non-pathogenic Saccharomyces cerevisiae possesses three different 2,3-butanediol biosynthetic pathways, but produces minute amount of 2,3-butanediol. Hence, we attempted to engineer S. cerevisiae strain to enhance 2,3-butanediol production. Results We first identified gene deletion strategy by performing in silico genome-scale metabolic analysis. Based on the best in silico strategy, in which disruption of alcohol dehydrogenase (ADH pathway is required, we then constructed gene deletion mutant strains and performed batch cultivation of the strains. Deletion of three ADH genes, ADH1, ADH3 and ADH5, increased 2,3-butanediol production by 55-fold under microaerobic condition. However, overproduction of glycerol was observed in this triple deletion strain. Additional rational design to reduce glycerol production by GPD2 deletion altered the carbon fluxes back to ethanol and significantly reduced 2,3-butanediol production. Deletion of ALD6 reduced acetate production in strains lacking major ADH isozymes, but it did not favor 2,3-butanediol production. Finally, we introduced 2,3-butanediol biosynthetic pathway from Bacillus subtilis and E. aerogenes to the engineered strain and successfully increased titer and yield. Highest 2,3-butanediol titer (2.29 g·l-1 and yield (0.113 g·g-1 were achieved by Δadh1 Δadh3 Δadh5 strain under anaerobic condition. Conclusions With the aid of in silico metabolic engineering, we have successfully designed and constructed S. cerevisiae strains with improved 2,3-butanediol production.

  5. 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.

  6. 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.

  7. Deletion of lactate dehydrogenase in Enterobacter aerogenes to enhance 2,3-butanediol production.

    Science.gov (United States)

    Jung, Moo-Young; Ng, Chiam Yu; Song, Hyohak; Lee, Jinwon; Oh, Min-Kyu

    2012-07-01

    2,3-Butanediol is an important bio-based chemical product, because it can be converted into several C4 industrial chemicals. In this study, a lactate dehydrogenase-deleted mutant was constructed to improve 2,3-butanediol productivity in Enterobacter aerogenes. To delete the gene encoding lactate dehydrogenase, λ Red recombination method was successfully adapted for E. aerogenes. The resulting strain produced a very small amount of lactate and 16.7% more 2,3-butanediol than that of the wild-type strain in batch fermentation. The mutant and its parental strain were then cultured with six different carbon sources, and the mutant showed higher carbon source consumption and microbial growth rates in all media. The 2,3-butanediol titer reached 69.5 g/l in 54 h during fed-batch fermentation with the mutant,which was 27.4% higher than that with the parental strain.With further optimization of the medium and aeration conditions,118.05 g/l 2,3-butanediol was produced in 54 h during fed-batch fermentation with the mutant. This is by far the highest titer of 2,3-butanediol with E. aerogenes achieved by metabolic pathway engineering.

  8. Phenolic compounds: Strong inhibitors derived from lignocellulosic hydrolysate for 2,3-butanediol production by Enterobacter aerogenes.

    Science.gov (United States)

    Lee, Sang Jun; Lee, Ju Hun; Yang, Xiaoguang; Kim, Sung Bong; Lee, Ja Hyun; Yoo, Hah Young; Park, Chulhwan; Kim, Seung Wook

    2015-12-01

    Lignocellulosic biomass are attractive feedstocks for 2,3-butanediol production due to their abundant supply and low price. During the hydrolysis of lignocellulosic biomass, various byproducts are formed and their effects on 2,3-butanediol production were not sufficiently studied compared to ethanol production. Therefore, the effects of compounds derived from lignocellulosic biomass (weak acids, furan derivatives and phenolics) on the cell growth, the 2,3-butanediol production and the enzymes activity involved in 2,3-butanediol production were evaluated using Enterobacter aerogenes ATCC 29007. The phenolic compounds showed the most toxic effects on cell growth, 2,3-butanediol production and enzyme activity, followed by furan derivatives and weak acids. The significant effects were not observed in the presence of acetic acid and formic acid. Also, feasibility of 2,3-butanediol production from lignocellulosic biomass was evaluated using Miscanthus as a feedstock. In the fermentation of Miscanthus hydrolysate, 11.00 g/L of 2,3-butanediol was obtained from 34.62 g/L of reducing sugar. However, 2,3-butanediol was not produced when the concentration of total phenolic compounds in the hydrolysate increased to more than 1.5 g/L. The present study provides useful information to develop strategies for biological production of 2,3-butanediol and to establish biorefinery for biochemicals from lignocellulosic biomass.

  9. 2,3-butanediol production by immobilized Enterobacter aerogenes IAM1133 with k-carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Chua, J.W.; Erarslan, A.; Kinoshita, S.; Taguchi, H.

    1980-01-01

    Enterbacter aerogenes IAM1133 was selected for 2,3-butanediol fermentation among 13 strains known to be 2,3-butanediol producers. This strain produced 11 mg/ml of 2,3-butanediol on 24-hr fermentation with 5% glucose. The cells were entrapped with k-carrageenan, which was activated in the medium to permit the growth in the matrix. It took one day to obtain the maximum activity of production and this activity was kept stable. The incubation conditions, such as pH, temperature, liquid volume (dissolved oxygen), and glucose concentration, for immobilized cells were not as sensitive as those for native cells. The production of 2,3-butanediol by the immobilized cells was carried out at pH 7 and at 30/sup 0/C with 5% glucose and 40 ml of medium in a 100 ml-flask. The long term production by immobilized cell was carried out by sequential replacement culture and continuous culture and they were stable without any loss of activity for at least 10 days. The production of acetoin was decreased by immobilization and the production of 2,3-butanediol by the cells released from the gel was negligible.

  10. 40 CFR 721.990 - 1,4-Benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol, cyclized.

    Science.gov (United States)

    2010-07-01

    ... ester, polymer with 1,4 - butanediol, cyclized. 721.990 Section 721.990 Protection of Environment..., dimethyl ester, polymer with 1,4 - butanediol, cyclized. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,4-benzedicarboxylic acid, dimethyl...

  11. 76 FR 7703 - 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4-Butanediol, Adipic Acid, and...

    Science.gov (United States)

    2011-02-11

    ... AGENCY 40 CFR Part 180 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4- Butanediol, Adipic... from the requirement of a tolerance for residues of 1,4-benzenedicarboxylic acid, dimethyl ester... residues of 1,4-benzenedicarboxylic acid, dimethyl ester, polymer with 1,4-butanediol, adipic acid,...

  12. Enhancement of 2,3-butanediol production by Klebsiella oxytoca PTCC 1402.

    Science.gov (United States)

    Anvari, Maesomeh; Safari Motlagh, Mohammad Reza

    2011-01-01

    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%.

  13. Engineered Enterobacter aerogenes for efficient utilization of sugarcane molasses in 2,3-butanediol production.

    Science.gov (United States)

    Jung, Moo-Young; Park, Bu-Soo; Lee, Jinwon; Oh, Min-Kyu

    2013-07-01

    Sugarcane molasses is considered to be a good carbon source for biorefinery due to its high sugar content and low price. Sucrose occupies more than half of the sugar in the molasses. Enterobacter aerogenes is a good host strain for 2,3-butanediol production, but its utilization of sucrose is not very efficient. To improve sucrose utilization in E. aerogenes, a sucrose regulator (ScrR) was disrupted from the genomic DNA. The deletion mutation increased the sucrose consumption rate significantly when sucrose or sugarcane molasses was used as a carbon source. The 2,3-butanediol production from sugarcane molasses by the mutant was enhanced by 60% in batch fermentation compared to that by the wild type strain. In fed-batch fermentation, 98.69 g/L of 2,3-butanediol production was achieved at 36 h.

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

    Directory of Open Access Journals (Sweden)

    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%.

  15. Crosslinking and modification of dermal sheep collagen using 1,4-butanediol diglycidyl ether

    NARCIS (Netherlands)

    Zeeman, R; Dijkstra, PJ; van Wachem, PB; van Luyn, MJA; Hendriks, M; Cahalan, PT; Feijen, J

    1999-01-01

    Crosslinking of dermal sheep collagen (DSC) was accomplished using 1,4-butanediol diglycidyl ether (BDDGE). At pH values > 8.0, epoxide groups of BDDGE will react with amine groups of collagen. The effects of BDDGE concentration, pH, time, and temperature were studied. Utilization of a 4-wt % BDDGE

  16. More efficient redox biocatalysis by utilising 1,4-butanediol as a ‘smart cosubstrate’

    NARCIS (Netherlands)

    Kara, S.; Spickermann, D.; Schrittwieser, J.H.; Leggewie,C.; Van Berkel, W.J.H.; Arendsa, I.W.C.E.; Hollmann, F.

    2012-01-01

    1,4-Butanediol is shown to be an efficient cosubstrate to promote NAD(P)H-dependent redox biocatalysis. The thermodynamically and kinetically inert lactone coproduct makes the regeneration reaction irreversible. Thereby not only the molar surplus of cosubstrate is dramatically reduced but also faste

  17. More efficient redox biocatalysis by utilizing 1,4-butanediol as a ‘smart cosubstrate'

    NARCIS (Netherlands)

    Kara, S.; Spickermann, D.; Schrittwieser, J.H.; Leggewie, C.; Berkel, van W.J.H.; Arends, I.W.C.E.; Hollmann, F.

    2013-01-01

    1,4-Butanediol is shown to be an efficient cosubstrate to promote NAD(P)H-dependent redox biocatalysis. The thermodynamically and kinetically inert lactone coproduct makes the regeneration reaction irreversible. Thereby not only the molar surplus of cosubstrate is dramatically reduced but also faste

  18. [GHB, GBL and butanediol poisonings--a serious problem in Western Sweden].

    Science.gov (United States)

    Knudsen, Kai; Greter, Joachim; Verdicchio, Mario; Cederquist, Thomas

    Acute poisoning with GHB (Gamma-hydroxybutyrate, Gamma-hydroxybutyric acid) has been an increasing medical and social problem during the last decade in Sweden, especially on the west coast. The number of poisonings decreased in the beginning of this millennium but has again increased during the last years. At the same time the number of seizures by the police has increased similarly as well as the number of drug-related deaths. During 2004 the number of GHB-abuse related deaths in western Sweden was seven, approximately the same figures as for heroin. Two other substances which are transformed to GHB in the human body, GBL (gamma-butyrolactone) and 1,4-butanediol, have during the last years presented themselves among the same users as for GHB. Since GBL and butanediol are not classified as illicit drugs the possibilities for the police force to intervene and capture the drugs are severely restricted. Intoxication by GBL and butanediol has shown to be as dangerous as intoxication by GHB. Acute intoxications and abuse of these drugs is still a serious medical and social problem. A legal classification of GBL and butanediol as narcotics appears to be medically motivated.

  19. 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 .

  20. 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.

  1. 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

    2016-01-01

    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. PMID:26729717

  2. Conversion of 2,3-butanediol to 2-butanol, olefins and fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, Michael A.; Lee, Guo-Shuh; Lee, Suh-Jane

    2016-12-13

    Embodiments of an integrated method for step-wise conversion of 2,3-butanediol to 2-butanol, and optionally to hydrocarbons, are disclosed. The method includes providing an acidic catalyst, exposing a composition comprising aqueous 2,3-butanediol to the acidic catalyst to produce an intermediate composition comprising methyl ethyl ketone, providing a hydrogenation catalyst that is spatially separated from the acidic catalyst, and subsequently exposing the intermediate composition to the hydrogenation catalyst to produce a composition comprising 2-butanol. The method may further include subsequently exposing the composition comprising 2-butanol to a deoxygenation catalyst, and deoxygenating the 2-butanol to form hydrocarbons. In some embodiments, the hydrocarbons comprise olefins, such as butenes, and the method may further include subsequently exposing the hydrocarbons to a hydrogenation catalyst to form saturated hydrocarbons.

  3. Separating 2,3-butanediol from fermentation broth using n-butylaldehyde

    Directory of Open Access Journals (Sweden)

    Yanjun Li

    2016-09-01

    Full Text Available In this paper, a complete separation process for 2,3-butanediol fermentation broth has been developed using reactive-extraction and reactive-distillation. n-Butylaldehyde can be used as both reactant and extractant in the process. Equilibrium and kinetics were studied on the reaction between 2,3-butanediol and n-butylaldehyde using different catalysts. Pseudo-Homogeneous model was used to describe the reaction behavior. The kinetic parameters were determined by analyzing experimental data. The results revealed that the reaction enthalpy ΔrH0 = −21.58 ± 1.63 kJ mol−1. The reaction rate was found to increase with increasing reaction temperature and had a linear correlation with catalyst amount. The activity energy for H2SO4 system and HCl system was 57.52 ± 5.35 and 58.14 ± 5.06 kJ mol−1, respectively. Feasible operation conditions have been obtained as follows: volume ratio of n-butylaldehyde to fermentation broth is 0.2; feed molar ratio of water and 2-propyl-4,5-dimethyl-1,3-dioxolane (n-butylaldehyde 2,3-butanediol acetal for hydrolysis is 3.0; theoretical plate number for reactive-distillation column is 10 with concentration of HCl solution of 0.5 mol/L. With the above conditions, more than 90% of 2,3-butanediol can be recovered from fermentation broth by reactive-extraction process and the purity of final product can be over 99%.

  4. Adsorption of 2,3-butanediol on Si(1 0 0)

    Science.gov (United States)

    Kim, J. W.; Carbone, M.; Tallarida, M.; Dil, J. H.; Horn, K.; Casaletto, M. P.; Flammini, R.; Piancastelli, M. N.

    2004-06-01

    The adsorption of 2,3-butanediol on a Si(1 0 0) surface has been investigated by photoelectron spectroscopy. The valence band spectra show features assigned to molecular orbitals of 2,3-butanediol by comparison with calculations, and the surface states of clean Si are removed. The Si 2p reveals core-level shifts with two new components at 0.24 and 0.97 eV from the bulk, which are assigned to Si-H and Si-O bonds, respectively. The C 1s core-level spectrum consists of two major peaks separated by 1.3 eV, which are attributed to carbon atoms in -CHOH and -CH 3 groups, in the molecule respectively. From the analysis of the valence band, the Si 2p, C 1s, and O 1s core-level spectra, we conclude that the 2,3-butanediol molecule undergoes a cleavage of the O-H bonds, and is bonded to the surface by the oxygen atoms. The molecule shows no further fragmentation and probably forms a six-membered ring of the O-C-C-O segment with the Si dimer atoms.

  5. 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

  6. Aqueous two-phase extraction of 2,3-butanediol from fermentation broths by isopropanol/ammonium sulfate system.

    Science.gov (United States)

    Sun, Li-Hui; Jiang, Bo; Xiu, Zhi-Long

    2009-03-01

    A novel aqueous two-phase system consisted of 2-propanol/ammonium sulfate was used for the extraction of 2,3-butanediol from fermentation broths. The maximum partition coefficient and recovery of 2,3-butanediol reached 9.9 and 93.7%, respectively, and more than 99% of the cells and about 85% of the soluble proteins were removed when 34% (w/w) 2-propanol and 20% (w/w) ammonium sulfate were used. The separated cells could be re-used as inocula for subsequent fermentations. The aqueous two-phase system described in this study may have potential application in the extraction of 2,3-butanediol produced by industrial fermentation processes.

  7. Biotechnological production of 2,3-butanediol from agroindustrial food waste

    Energy Technology Data Exchange (ETDEWEB)

    Canepa, P.; Cauglia, F.; Gilio, A.; Perego, P. [Genoa Univ., Genoa (Italy)

    2000-07-01

    The exploitation of common agroindustrial wastes to produce important industrial bioproducts was examined during a research study in which the solvent glycol was bioproduced for industrial applications. The preliminary results of fermentation on starch hydrolysate, sugar beet molasses and cheese whey by microorganisms were presented. Currently, 2,3-butanediol synthesizes by chemical pathways even though its biotechnological production from industrial wastes has two interesting possibilities. These include the low production costs of fermentation to obtain a compound with a huge market, plus the reduced environmental impact of waste pollution by biodegradation. In this study, pure cultures of Enterobacter aerogenes were used in a stirred batch reactor under micro-aerobic conditions. In order to determine the optimal working conditions for bacterial production of 2,3-butanediol on a glucose solution, several batch fermentations were conducted at different pH levels, temperatures and substrate concentrations. It was determined that the final glycol concentration increases with the increase in initial substrate composition even when the product yield decreases. 14 refs., 1 tab., 4 figs.

  8. 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.

  9. Improved production of 2,3-butanediol in Bacillus amyloliquefaciens by over-expression of glyceraldehyde-3-phosphate dehydrogenase and 2,3-butanediol dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Taowei Yang

    Full Text Available BACKGROUND: Previously, a safe strain, Bacillus amyloliquefaciens B10-127 was identified as an excellent candidate for industrial-scale microbial fermentation of 2,3-butanediol (2,3-BD. However, B. amyloliquefaciens fermentation yields large quantities of acetoin, lactate and succinate as by-products, and the 2,3-BD yield remains prohibitively low for commercial production. METHODOLOGY/PRINCIPAL FINDINGS: In the 2,3-butanediol metabolic pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH catalyzes the conversion of 3-phosphate glyceraldehyde to 1,3-bisphosphoglycerate, with concomitant reduction of NAD(+ to NADH. In the same pathway, 2,3-BD dehydrogenase (BDH catalyzes the conversion of acetoin to 2,3-BD with concomitant oxidation of NADH to NAD(+. In this study, to improve 2,3-BD production, we first over-produced NAD(+-dependent GAPDH and NADH-dependent BDH in B. amyloliquefaciens. Excess GAPDH reduced the fermentation time, increased the 2,3-BD yield by 12.7%, and decreased the acetoin titer by 44.3%. However, the process also enhanced lactate and succinate production. Excess BDH increased the 2,3-BD yield by 16.6% while decreasing acetoin, lactate and succinate production, but prolonged the fermentation time. When BDH and GAPDH were co-overproduced in B. amyloliquefaciens, the fermentation time was reduced. Furthermore, in the NADH-dependent pathways, the molar yield of 2,3-BD was increased by 22.7%, while those of acetoin, lactate and succinate were reduced by 80.8%, 33.3% and 39.5%, relative to the parent strain. In fed-batch fermentations, the 2,3-BD concentration was maximized at 132.9 g/l after 45 h, with a productivity of 2.95 g/l·h. CONCLUSIONS/SIGNIFICANCE: Co-overexpression of bdh and gapA genes proved an effective method for enhancing 2,3-BD production and inhibiting the accumulation of unwanted by-products (acetoin, lactate and succinate. To our knowledge, we have attained the highest 2,3-BD fermentation yield thus far

  10. 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

  11. Enlarged test catalysts during the hydrogenation of 1,4-butynediol to 1,4-butanediol

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2013-09-01

    Full Text Available The highly effective catalyzer for butynediol-1;4 hydrogenation was designed and synthesized. Enlarged tests showed that the selectivity on butanediol-1.4 at the hydrogenation of butynediol-1.4 on the alloyed catalyst SKN-39H during 320 h was 84.6 %; that on 18 % higher than for  industrial MNH. The yield of product on the catalyst SKN-39 increases slowly from 3.1 to 7.3 % when on a catalyst MNH – 7.1 to 11.7 % from the initial content of butynediol-1;4. At the hydrogenation of  butynediol on catalyst SKN-39H process efficiency increases in 1.5-2 times and product purity on 2-3 % is higher in comparing with the industrial catalyst MNH. 

  12. 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.

  13. 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.

  14. Influence of dispersity on the activity, selectivity, and stability of Raney-Nickel catalyst during the hydrogenation of 1,4-butynediol into 1,4-butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Rusina, S.V.; Litvin, E.F.; Kheifets, V.I.; Sharf, V.Z.

    1992-07-10

    Raney-nickel catalysts are widely used in the hydrogenation of 1,4-butynediol into 1,4-butanediol, an important intermediate for the preparation of thermostable resins, plasticizers, pharmaceutical preparations, and other compounds. The authors carried out the investigation of the influence of the dispersity of the Raney-nickel catalysts on their activity, selectivity, and stability in the hydrogenation reaction of 1,4-butynediol into 1,4-butanediol.

  15. 2,3-Butanediol production by Enterobacter aerogenes: selection of the optimal conditions and application to food industry residues

    Energy Technology Data Exchange (ETDEWEB)

    Perego, P.; Converti, A.; Del Borghi, A. [Dept. of Chemical Engineering, Genoa Univ. (Italy); Canepa, P. [Dept. of Chemistry and Industrial Chemistry, Genoa Univ. (Italy)

    2000-12-01

    Optimum values of temperature, pH, and starting substrate concentration are experimentally determined for 2,3-butanediol production by Enterobacter aerogenes through three set of batch fermentations of synthetic glucose solutions. The results of tests carried out at variable temperature show an optimum of 39 C and are used to estimate, for both fermentation and thermal inactivation, the activation enthalpies (7.19 and 23.6 kJ mol{sup -1}) and the related entropies (-0.32 and -0.27 kJ mol{sup -1} K{sup -1}). An optimum pH value of 6.0 is evidenced from batch runs at variable pH, whose results are also used to make reasonable hypotheses on the reaction controlling the metabolic pathway which leads to butanediol. The fermentability of different food industry wastes, namely starch hydrolysate, both raw and decoloured molasses, and whey, is finally checked. (orig.)

  16. 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.

  17. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis

    Science.gov (United States)

    Kandasamy, Vijayalakshmi; Liu, Jianming; Dantoft, Shruti Harnal; Solem, Christian; Jensen, Peter Ruhdal

    2016-01-01

    The potential that lies in harnessing the chemical synthesis capabilities inherent in living organisms is immense. Here we demonstrate how the biosynthetic machinery of Lactococcus lactis, can be diverted to make (3R)-acetoin and the derived 2,3-butanediol isomers meso-(2,3)-butanediol (m-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added chemicals. PMID:27857195

  18. 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.

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    Katayoun Javidnia

    2016-01-01

    Full Text Available 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.

  1. 2,3-Butanediol recovery from fermentation broth by alcohol precipitation and vacuum distillation.

    Science.gov (United States)

    Jeon, Sangjun; Kim, Duk-Ki; Song, Hyohak; Lee, Hee Jong; Park, Sunghoon; Seung, Doyoung; Chang, Yong Keun

    2014-04-01

    This study presents a new and effective downstream process to recover 2,3-butanediol (2,3-BD) from fermentation broth which is produced by a recombinant Klebsiella pneumoniae strain. The ldhA-deficient K. pneumoniae strain yielded about 90 g/L of 2,3-BD, along with a number of by-products, such as organic acids and alcohols, in a 65 h fed-batch fermentation. The pH-adjusted cell-free fermentation broth was firstly concentrated until 2,3-BD reached around 500 g/L by vacuum evaporation at 50°C and 50 mbar vacuum pressure. The concentrated solution was further treated using light alcohols, including methanol, ethanol, and isopropanol, for the precipitation of organic acids and inorganic salts. Isopropanol showed the highest removal efficiency, in which 92.5% and 99.8% of organic acids and inorganic salts were precipitated, respectively. At a final step, a vacuum distillation process enabled the recovery of 76.2% of the treated 2,3-BD, with 96.1% purity, indicating that fermentatively produced 2,3-BD is effectively recovered by a simple alcohol precipitation and vacuum distillation.

  2. Production of 2,3-butanediol by Klebsiella pneumoniae from enzymatic hydrolyzate of sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Yuanquan Song

    2012-11-01

    Full Text Available Fermentation conditions for 2,3-butanediol (2,3-BD production by Klebsiella pneumoniae CGMCC1.9131 were optimized statistically in shake flasks. Four significant factors including the initial concentrations of yeast extract, glucose, K2HPO4, and (NH42SO4 were optimized by Response Surface Methodology (RSM. To further improve the yield of 2,3-BD, EDTA Na2 was added to the medium. After optimization, the yield of 2,3-BD was 0.44 g/g glucose and the final concentration was 26.20 g/L when initial glucose concentration was 60 g/L. The enzymatic hydrolyzate of pretreated sugarcane bagasse by alkali-peracetic acid (PAA and dilute acid were further used as feedstock to produce 2,3-BD under the optimized conditions, and the yields of 2,3-BD were 0.36 and 0.43 g/g consumed sugars, respectively. The experimental results indicated that the enzymatic hydrolyzate could be well converted to 2,3-BD.

  3. Present state and perspective of downstream processing of biologically produced 1,3-propanediol and 2,3-butanediol.

    Science.gov (United States)

    Xiu, Zhi-Long; Zeng, An-Ping

    2008-04-01

    1,3-Propanediol and 2,3-butanediol are two promising chemicals which have a wide range of applications and can be biologically produced. The separation of these diols from fermentation broth makes more than 50% of the total costs in their microbial production. This review summarizes the present state of methods studied for the recovery and purification of biologically produced diols, with particular emphasis on 1,3-propoanediol. Previous studies on the separation of 1,3-propanediol primarily include evaporation, distillation, membrane filtration, pervaporation, ion exchange chromatography, liquid-liquid extraction, and reactive extraction. Main methods for the recovery of 2,3-butanediol include steam stripping, pervaporation, and solvent extraction. No single method has proved to be simple and efficient, and improvements are especially needed with regard to yield, purity, and energy consumption. Perspectives for an improved downstream processing of biologically produced diols, especially 1,3-propanediol are discussed based on our own experience and recent work. It is argued that separation technologies such as aqueous two-phase extraction with short chain alcohols, pervaporation, reverse osmosis, and in situ extractive or pervaporative fermentations deserve more attention in the future.

  4. 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.

  5. Liquid-liquid equilibrium data for the separation of 2,3-butanediol from aqueous streams using tetraoctyl ammonium 2-methyl-1-naphthoate

    NARCIS (Netherlands)

    Garcia Chavez, L.Y.; Shazad, M.; Schuur, B.; Haan, de A.B.

    2012-01-01

    Microbiological production of 2,3-butanediol (2,3-BD) through fermentation using renewable feedstock is a promising option for the production of bio based chemicals. Liquid–liquid extraction could be a more efficient process, if a proper solvent is used. Tetraoctyl ammonium 2-methyl-1-naphthoate [TO

  6. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis

    DEFF Research Database (Denmark)

    Kandasamy, Vijayalakshmi; Liu, Jianming; Dantoft, Shruti Harnal

    2016-01-01

    -BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell......-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. [Current knowledge on gamma-hydroxybutyric acid (GHB), gamma-butyrolactone (GBL) and 1 ,4-butanediol (1,4-BD)].

    Science.gov (United States)

    Dematteis, Maurice; Pennel, Lucie; Mallaret, Michel

    2012-05-01

    Gamma-hydroxybutyric acid (GHB) is an old anaesthetic drug which was misused in the 80-90's as an anabolic agent (bodybuilding), recreational drug (drunkenness, euphoric, disinhibiting and aphrodisiac effects) and as a date rape drug (disinhibiting, hypnotic and amnesic effects). Its use in the general population is low, and mainly concerns gay population in nightclubs and young people in parties. The intoxications, above all with alcohol combination, can be severe, with coma and breathing depression, or even fatal. Chronic use leads to psychic and physical dependence; withdrawal syndrome can be severe, with agitation and delirium. In 1999, GHB classification as a narcotic resulted in the increased use of GHB prodrugs gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), which were easily commercially available as solvent and cleaning products. Like GHB, they have a narrow window of use, and share similar toxicity. Their increased cases of recreational use and of severe drug intoxication, abuse and dependence, led the French Ministry of Health in 2011 to prohibit their sale and transfer to the public.

  13. Comparison of the actions of gamma-butyrolactone and 1,4-butanediol in Swiss-Webster mice.

    Science.gov (United States)

    de Fiebre, Christopher M; de Fiebre, Nancy Ellen C; Coleman, Scott L; Forster, Michael J

    2004-04-01

    The abuse of gamma-hydroxybutyrate (GHB) and two of its precursors, gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) are recognized as a public health concern. Here, we report dose-response and time-course analyses for effects of GBL and 1,4-BD on locomotor activity and body temperature in Swiss-Webster mice. Locomotor activity was measured for 2 h following a single injection of one of four doses of each agent plus a saline vehicle control. At 50 mg/kg, GBL produced an initial depression of locomotor activity which was followed by stimulation of locomotor activity. In contrast, 1,4-BD at 50 mg/kg stimulated locomotor activity without producing any depression of activity. At higher doses, GBL produced primarily a dose-dependent decrease in locomotor activity that returned to baseline within 50 min. In contrast, 1,4-BD produced an initial depression which was followed by stimulation of activity. Body temperature was measured rectally across a 2.5-h time course following injection with either agent. Both drugs produced hypothermia with peak effects occurring at 20 and 30 min for both drugs for the lower and higher dose, respectively. At 150 mg/kg, GBL produced a greater hypothermic response; however, no differences in hypothermic response were observed at 100 mg/kg. These studies demonstrate that the precursor drugs to GHB have some differential actions from each other.

  14. Acute toxicity and withdrawal syndromes related to γ-hydroxybutyrate (GHB) and its analogues γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD).

    Science.gov (United States)

    Wood, David M; Brailsford, Alan D; Dargan, Paul I

    2011-01-01

    Gamma-hydroxybutyrate (GHB) has been used as a recreational drug since the 1990s and over the last few years there has been increasing use of its analogues gamma-butyrolactone (GBL) and to a lesser extent 1,4-butanediol (1,4BD). This review will summarize the literature on the pharmacology of these compounds; the patterns and management of acute toxicity associated with their use; and the clinical patterns of presentation and management of chronic dependency associated with GHB and its analogues.

  15. 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).

  16. (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.

  17. Extraction of vitexin from binahong (Anredera cordifolia (Ten.) Steenis) leaves using betaine - 1,4 butanediol natural deep eutectic solvent (NADES)

    Science.gov (United States)

    Mulia, Kamarza; Muhammad, Fajri; Krisanti, Elsa

    2017-03-01

    The leaves of binahong (Anredera cordifolia (Ten) Steenis) contain flavonoids as bioactive substances that have efficacy to treat wounds and diseases caused by bacteria. One of the flavonoids contained in the leaves is 8-glucopyranosyl-4'5'7-trihydroxyflavone or vitexin. Conventional extraction of flavonoids from leaves of binahong has been developed and usually using non-friendly organic solvent. To overcome these problems, a Natural Deep Eutectic Solvent (NADES) is used to replace the conventional organic solvents, as it is an environmentally friendly, non-toxic and high boiling point solvent. In this study, a betaine-based NADES combined with 1,4-butanediol in 1:3 mole ratio was used as the extraction solvent. Vitexin in the extract was analyzed qualitatively and quantitatively using an HPLC. The extraction of vitexin from binahong leaves at room temperature (27 °C) for four hours give yield of 46 ppm, much lower than 200 ppm yield obtained after extraction at 55 °C for 90 minutes. This results showed that (a) NADES consisting of betaine and 1,4 butanediol is a promising green solvent for extraction of vitexin from binahong leaves, and, (b) the extraction can be performed above ambient temperature, as long as it does not exceed the degradation temperature of the bioactive compound extracted.

  18. Systematic metabolic engineering of Escherichia coli for high-yield production of fuel bio-chemical 2,3-butanediol.

    Science.gov (United States)

    Xu, Youqiang; Chu, Haipei; Gao, Chao; Tao, Fei; Zhou, Zikang; Li, Kun; Li, Lixiang; Ma, Cuiqing; Xu, Ping

    2014-05-01

    The production of biofuels by recombinant Escherichia coli is restricted by the toxicity of the products. 2,3-Butanediol (2,3-BD), a platform and fuel bio-chemical with low toxicity to microbes, could be a promising alternative for biofuel production. However, the yield and productivity of 2,3-BD produced by recombinant E. coli strains are not sufficient for industrial scale fermentation. In this work, the production of 2,3-BD by recombinant E. coli strains was optimized by applying a systematic approach. 2,3-BD biosynthesis gene clusters were cloned from several native 2,3-BD producers, including Bacillus subtilis, Bacillus licheniformis, Klebsiella pneumoniae, Serratia marcescens, and Enterobacter cloacae, inserted into the expression vector pET28a, and compared for 2,3-BD synthesis. The recombinant strain E. coli BL21/pETPT7-EcABC, carrying the 2,3-BD pathway gene cluster from Enterobacter cloacae, showed the best ability to synthesize 2,3-BD. Thereafter, expression of the most efficient gene cluster was optimized by using different promoters, including PT7, Ptac, Pc, and Pabc. E. coli BL21/pET-RABC with Pabc as promoter was superior in 2,3-BD synthesis. On the basis of the results of biomass and extracellular metabolite profiling analyses, fermentation conditions, including pH, agitation speed, and aeration rate, were optimized for the efficient production of 2,3-BD. After fed-batch fermentation under the optimized conditions, 73.8g/L of 2,3-BD was produced by using E. coli BL21/pET-RABC within 62h. The values of both yield and productivity of 2,3-BD obtained with the optimized biological system are the highest ever achieved with an engineered E. coli strain. In addition to the 2,3-BD production, the systematic approach might also be used in the production of other important chemicals through recombinant E. coli strains.

  19. Evaluation for the withdrawal syndrome from gamma-hydroxybutyric acid (GHB), gamma-butyrolactone (GBL), and 1,4-butanediol (1,4-BD) in different rat lines.

    Science.gov (United States)

    Quang, Lawrence S; Colombo, Giancarlo; Lobina, Carla; Maccioni, Paola; Orru, Alessandro; Gessa, Gian Luigi; Maher, Timothy J; Carai, Mauro A M

    2006-08-01

    A severe and life-threatening gamma-hydroxybutyric acid (GHB) withdrawal syndrome, clinically similar to the alcohol withdrawal syndrome, is increasingly being reported in GHB addicts. We investigated for the occurrence of withdrawal in Wistar and Sprague-Dawley rats, and in the selectively bred lines of GHB-sensitive (GHB-S) and Sardinian alcohol-preferring (sP) rats, following chronic administration of GHB, gamma-butyrolactone (GBL), and/or 1,4-butanediol (1,4-BD). Using validated rodent alcohol withdrawal scoring scales, little to no spontaneous or pharmacologically precipitated withdrawal effects were observed in Wistar, Sprague-Dawley, or GHB-S rats. Conversely, sP rats displayed both spontaneous and precipitated audiogenic seizures following abrupt cessation of chronic GHB or 1,4-BD administration and following pharmacological challenge with the GABA(B) receptor-selective antagonist, SCH 50911, respectively.

  20. 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 l...... 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.......M 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...

  1. 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.

  2. 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.

  3. Enhanced production of 2,3-butanediol in pyruvate decarboxylase-deficient Saccharomyces cerevisiae through optimizing ratio of glucose/galactose.

    Science.gov (United States)

    Choi, Eun-Ji; Kim, Jin-Woo; Kim, Soo-Jung; Seo, Seung-Oh; Lane, Stephan; Park, Yong-Cheol; Jin, Yong-Su; Seo, Jin-Ho

    2016-11-01

    Galactose and glucose are two of the most abundant monomeric sugars in hydrolysates of marine biomasses. While Saccharomyces cerevisiae can ferment galactose, its uptake is tightly controlled in the presence of glucose by catabolite repression. It is desirable to construct engineered strains capable of simultaneous utilization of glucose and galactose for producing biofuels and chemicals from marine biomass. The MTH1 gene coding for transcription factor in glucose signaling was mutated in a pyruvate decarboxylase (Pdc)-deficient S. cerevisiae expressing heterologous 2,3-butanediol (2,3-BD) biosynthetic genes. The engineered S. cerevisiae strain consumed glucose and galactose simultaneously and produced 2,3-BD as a major product. Total sugar consumption rates increased with a low ratio of glucose/galactose, though, occurrence of the glucose depletion in a fed-batch fermentation decreased 2,3-BD production substantially. Through optimizing the profiles of sugar concentrations in a fed-batch cultivation with the engineered strain, 99.1 ± 1.7 g/L 2,3-BD was produced in 143 hours with a yield of 0.353 ± 0.022 g 2,3-BD/g sugars. This result suggests that simultaneous and efficient utilization of glucose and galactose by the engineered yeast might be applicable to the economical production of not only 2,3-BD, but also other biofuels and chemicals from marine biomass.

  4. Deletion of the budBAC operon in Klebsiella pneumoniae to understand the physiological role of 2,3-butanediol biosynthesis.

    Science.gov (United States)

    Jeong, Daun; Yang, Jeongmo; Lee, Soojin; Kim, Borim; Um, Youngsoon; Kim, Youngrok; Ha, Kyoung-Su; Lee, Jinwon

    2016-05-18

    Klebsiella pneumoniae is known to produce 2,3-butanediol (2,3-BDO), a valuable chemical. In K. pneumoniae, the 2,3-BDO operon (budBAC) is involved in the production of 2,3-BDO. To observe the physiological role of the 2,3-BDO operon in a mixed acid fermentation, we constructed a budBAC-deleted strain (SGSB109). The production of extracellular metabolites, CO2 emission, carbon distribution, and NADH/NAD(+) balance of SGSB109 were compared with the parent strain (SGSB100). When comparing the carbon distribution at 15 hr, four significant differences were observed: in 2,3-BDO biosynthesis, lactate and acetate production (lactate and acetate production increased 2.3-fold and 4.1-fold in SGSB109 compared to SGSB100), CO2 emission (higher in SGSB100), and carbon substrate uptake (higher in SGSB100). Previous studies on the inactivation of the 2,3-BDO operon were focused on the increase of 1,3-propanediol production. Few studies have been done observing the role of 2,3-BDO biosynthesis. This study provides a prime insight into the role of 2,3-BDO biosynthesis of K. pneumoniae.

  5. 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.

  6. 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.

  7. 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。

  8. 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)

  9. 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.

  10. Bis-butanediol-mercapturic acid (bis-BDMA) as a urinary biomarker of metabolic activation of butadiene to its ultimate carcinogenic species.

    Science.gov (United States)

    Kotapati, Srikanth; Sangaraju, Dewakar; Esades, Amanda; Hallberg, Lance; Walker, Vernon E; Swenberg, James A; Tretyakova, Natalia Y

    2014-06-01

    Human carcinogen 1,3-butadiene (BD) undergoes metabolic activation to 3,4-epoxy-1-butene (EB), hydroxymethylvinyl ketone (HMVK), 3,4-epoxy-1,2-butanediol (EBD) and 1,2,3,4-diepoxybutane (DEB). Among these, DEB is by far the most genotoxic metabolite and is considered the ultimate carcinogenic species of BD. We have shown previously that BD-exposed laboratory mice form 8- to 10-fold more DEB-DNA adducts than rats exposed at the same conditions, which may be responsible for the enhanced sensitivity of mice to BD-mediated cancer. In the present study, we have identified 1,4-bis-(N-acetyl-L-cystein-S-yl)butane-2,3-diol (bis-BDMA) as a novel DEB-specific urinary biomarker. Isotope dilution high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was employed to quantify bis-BDMA and three other BD-mercapturic acids, 2-(N-acetyl-L-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-L-cystein-S-yl)-2-hydroxy-but-3-ene (MHBMA, from EB), 4-(N-acetyl-L-cystein-S-yl)-1,2-dihydroxybutane (DHBMA, from HMVK) and 4-(N-acetyl-L-cystein-S-yl)-1,2,3-trihydroxybutane (THBMA, from EBD), in urine of confirmed smokers, occupationally exposed workers and BD-exposed laboratory rats. Bis-BDMA was formed in a dose-dependent manner in urine of rats exposed to 0-200 p.p.m. BD by inhalation, although it was a minor metabolite (1%) as compared with DHBMA (47%) and THBMA (37%). In humans, DHBMA was the most abundant BD-mercapturic acid excreted (93%), followed by THBMA (5%) and MHBMA (2%), whereas no bis-BDMA was detected. These results reveal significant differences in metabolism of BD between rats and humans.

  11. Metabolic engineering of Enterobacter cloacae for high-yield production of enantiopure (2R,3R)-2,3-butanediol from lignocellulose-derived sugars.

    Science.gov (United States)

    Li, Lixiang; Li, Kun; Wang, Yu; Chen, Chao; Xu, Youqiang; Zhang, Lijie; Han, Binbin; Gao, Chao; Tao, Fei; Ma, Cuiqing; Xu, Ping

    2015-03-01

    Biotechnological production of biofuels is restricted by toxicity of the products such as ethanol and butanol. As its low toxicity to microbes, 2,3-butanediol (2,3-BD), a fuel and platform bio-chemical, could be a promising alternative for biofuel production from renewable bioresources. In addition, no bacterial strains have been reported to produce enantiopure 2,3-BD using lignocellulosic hydrolysates. In this study, Enterobacter cloacae strain SDM was systematically and metabolically engineered to construct an efficient biocatalyst for production of the fuel and enantiopure bio-chemical-(2R,3R)-2,3-BD. First, the various (2R,3R)-2,3-BD dehydrogenase encoding genes were expressed in a meso-2,3-BD dehydrogenase encoding gene disrupted E. cloacae strain under native promoter Pb of the 2,3-BD biosynthetic gene cluster of E. cloacae. Then, carbon catabolite repression was eliminated via inactivation of the glucose transporter encoding gene ptsG and overexpression of a galactose permease encoding gene galP. The resultant strain could utilize glucose and xylose simultaneously. To improve the efficiency of (2R,3R)-2,3-BD production, the byproduct-producing genes (ldh and frdA) were knocked out, thereby enhancing the yield of (2R,3R)-2,3-BD by 16.5% in 500-mL Erlenmeyer flasks. By using fed-batch fermentation in a 5-L bioreactor, 152.0 g/L (2R,3R)-2,3-BD (purity>97.5%) was produced within 44 h with a specific productivity of 3.5 g/[Lh] and a yield of 97.7% from a mixture of glucose and xylose, two major carbohydrate components in lignocellulosic hydrolysates. In addition, when a lignocellulosic hydrolysate was used as the substrate, 119.4 g/L (2R,3R)-2,3-BD (purity>96.0%) was produced within 51 h with a productivity of 2.3g/[Lh] and a yield of 95.0%. These results show that the highest records have been acquired for enantiopure (2R,3R)-2,3-BD production by a native or engineered strain from biomass-derived sugars. In addition to producing the 2,3-BD, our systematic

  12. Development and study on extraction coupled distillation technology for 2,3-butanediol separation%2,3-丁二醇萃取-精馏耦合工艺开发研究

    Institute of Scientific and Technical Information of China (English)

    吴艳阳; 朱家文; 陈葵; 武斌; 沈亚领

    2011-01-01

    在前期液-液相平衡研究的基础上,得出正丁醇、乙酸乙酯及乙酸丁酯在萃取2,3-丁二醇时的不同特点.并根据其特点,分别设计了2条创新的间歇-循环的萃取-精馏耦合工艺.根据乙酸乙酯、乙酸丁酯分配系数小、相比(质量比)要求较大的特点,设计萃取-精馏耦合工艺一(即溶剂循环、料液间歇进料),该工艺具有相比逐渐增大、溶剂循环萃取的特点;根据正丁醇分相区小、可调相比范围较小的特点,设计了萃取-精馏耦合工艺二(即溶剂与精馏后水相连续循环、料液间歇进料),该工艺具有相比不变、溶剂循环萃取的特点.以2,3-丁二醇萃取率及溶剂损失率为指标,对2条萃取工艺进行考察,得出相应的可行工艺条件.在此条件下,2,3-丁二醇的萃取率均可大于90%,从而有效地解决了3种溶剂采用常规萃取工艺均无法很好地实现提取2,3-丁二醇的难题.%The characteristics of three solvents including n-butanol, ethyl acetate and butyl acetate were confirmed on the basis of the liquid-liquid equilibrium data of prior-phase lab experimental study. According to the characteristics, two innovative batch-continuous extraction technological routines were designed and studied, respectively. When ethyl acetate or butyl acetate is taken as extraction solvent, the distribution coefficients are small and big phase ratio (mass ratio) is necessary to satisfy 2,3-butanediol extraction. The corresponding extraction coupled distillation technology No. 1 (solvent is continuous and feed is discontinuous) is designed. This technology has the characteristics of gradually increasing phase ratio and continuous extraction. When n-butanol is taken as extraction solvent, the heterogeneous zone and the range of practical phase ratio are small. And the corresponding extraction coupled distillation technology No. 2 (solvent and aqueous phase after rectification are continuous and feed is

  13. 利用嗜盐菌Salinivibrio YS生产2,3-丁二醇和琥珀酸%Production of 2, 3-butanediol and succinic acid by Salinivibrio YS

    Institute of Scientific and Technical Information of China (English)

    薛源生; 古丽斯玛依·艾拜都拉; 陈国强

    2011-01-01

    以从新疆艾丁湖采集的土样中分离出的中度嗜盐菌Salinivibrio YS为研究对象,利用该菌在厌氧条件下生产2,3-丁二醇和琥珀酸,在单因素摇瓶实验基础上,确定影响产物积累的各因素及其相应条件,再利用正交试验确定这些参数的最佳水平,即温度33℃,起始pH为8.0,发酵过程pH为7.0,乙酸添加量为3 g/L,NaCl浓度为l0 g/L.利用优化条件进行3L体系的发酵放大实验,经过108 h的无氧发酵,2,3-丁二醇的产量可达35.05 g/L,而琥珀酸的含量则高达22.46 g/L,且其糖的总转化率高达约50%.首次利用嗜盐菌在厌氧条件下生产2,3-丁二醇和琥珀酸,拓展了嗜盐菌的应用,同时也为生产2,3-丁二醇和琥珀酸提供了新的思路.%The production of 2, 3-butanediol and succinic acid by a moderate halophile under anaerobic condition was investigated. This halophile, termed Salinivibrio YS, was isolated from the solid samples collected from Aydingkol Lake. Based on the single factor experiment, the parameters and their values for the production were obtained. Then, the optimum values of these parameters by the orthogonal experiments were obtained: temperature, 33 °C; initial pH of fermentation, 8.0; the pH during fermentation, 7.0; the concentration of acetic acid was 3 g/L and NaCl was 10 g/L. Finally, a 3-L fermentation based on these conditions was carried out. After 108 h of fermentation under anaerobic condition, 35.05 g/L of 2, 3-butanediol and 22.46 g/L of succinic acid were obtained. About 50% of total glucose conversion was achieved. The study on 2,3-butanediol and succinic acid by a halophile under anaerobic condition will expand the applications of halophiles and open a new area of production of 2,3-butanediol and succinic acid.

  14. 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.

  15. Gamma-Hydroxybutyrate (GHB), gamma-butyrolactone (GBL), and 1,4-butanediol (1,4-BD) reduce the volume of cerebral infarction in rodent transient middle cerebral artery occlusion.

    Science.gov (United States)

    Sadasivan, Shankar; Maher, Timothy J; Quang, Lawrence S

    2006-08-01

    gamma-Hydroxybutyric acid (GHB), an endogenous organic acid catabolite of gamma-aminobutyric acid (GABA), has been shown to have tissue-protective effects in various organs, including the brain. We examined the potential neuroprotective effect of GHB and its chemical precursors, gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), in the rodent ischemic stroke model by intraluminal filament middle cerebral artery occlusion (MCAO). Adult male Sprague-Dawley rats underwent transient left-sided MCAO and received intraperitoneal treatment with 300 mg/kg of GHB, GBL, 1,4-BD, or control vehicle given at 30 min before, as well as 180 and 360 min after the onset of ischemia. Infarct volumes were determined 24 h after MCAO. In transient MCAO, the mean volume of infarction for control rats was 464.4 +/- 17.9 cu.mm versus 273.6 +/- 53.1, 233.3 +/- 44.7, and 275.4 +/- 39.9 cu.mm for rats treated with 1,4-BD (P GBL (P GBL, and 1,4-BD protect against rat focal cerebral ischemia from transient MCAO.

  16. 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.

  17. Determination of γ-hydroxybutyrate (GHB), β-hydroxybutyrate (BHB), pregabalin, 1,4-butane-diol (1,4BD) and γ-butyrolactone (GBL) in whole blood and urine samples by UPLC-MSMS.

    Science.gov (United States)

    Dahl, Sandra Rinne; Olsen, Kirsten Midtbøen; Strand, Dag Helge

    2012-02-15

    The demand of high throughput methods for the determination of gamma-hydroxybutyrate (GHB) and its precursors gamma-butyrolactone (GBL) and 1,4-butane-diol (1,4BD) as well as for pregabalin is increasing. Here we present two analytical methods using ultra-high pressure liquid chromatography (UPLC) and tandem mass spectrometric (MS/MS) detection for the determination of GHB, beta-hydroxybutyrate (BHB), pregabalin, 1,4BD and GBL in whole blood and urine. Using the 96-well formate, the whole blood method is a simple high-throughput method suitable for screening of large sample amounts. With an easy sample preparation for urine including only dilution and filtration of the sample, the method is suitable for fast screening of urine samples. Both methods showed acceptable linearity, acceptable limits of detection, and limits of quantification. The within-day and between-day precisions of all analytes were lower than 10% RSD. The analytes were extracted from matrices with recoveries near 100%, and no major matrix effects were observed. Both methods have been used as routine screening analyses of whole blood and urine samples since January 2010.

  18. 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.

  19. 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。

  20. 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.

  1. 接种污泥对UASB处理1,4-丁二醇生产废水的影响%Effect of Inoculated Sludge on Treatment of Wastewater from 1,4-butanediol Production in UASB Reactor

    Institute of Scientific and Technical Information of China (English)

    郑陈华; 魏宏斌; 邹平; 陈良才; 操起顺

    2013-01-01

    Three upflow anaerobic sludge bed ( UASB) reactors inoculated with granular sludge, flocculent sludge and a combination of both types of sludge were used for treatment of wastewater from 1 ,4-butanediol production. The influence of inoculated sludge on the treatment efficiency was investigated. The results showed that the reactor inoculated with granular sludge achieved the highest treatment efficiency. The inoculation of granular sludge could improve the maximum COD volume loading rate, anti-load capacity and biogas production as well as reduce inhibition of high VFA to microbial activity. The maximum COD volume loading rates of three reactors were 4. 70 kg/( m3·d) , 3. 25 kg/( m3·d) and 4.50 kg/(m3·d) respectively when the COD removal rate was more than 70%.%采用UASB反应器处理1,4-丁二醇生产废水时,分别接种颗粒污泥、絮状污泥及两者的混合污泥,研究不同接种污泥对处理效果的影响.结果表明,接种颗粒污泥的反应器处理效果最好,但接种混合污泥时亦能取得较好的驯化及处理效果;接种颗粒污泥可以提高系统的最大COD容积负荷、抗污染负荷冲击能力及产气量,同时可降低挥发性脂肪酸的积累对微生物活性的抑制;在保持COD去除率>70%的条件下,3组反应器的最大COD容积负荷分别为4.70、3.25和4.50 kg/(m3·d).

  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. 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

  4. 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.

  5. H_9P_2W_(15)V_3/C催化1,4-丁二醇环化脱水制备四氢呋喃%Dehydration of 1,4-butanediol to tetrahydrofuran catalyzed by H9P2W15V3/C

    Institute of Scientific and Technical Information of China (English)

    曹小华; 严平; 谢宝华; 徐常龙; 邱丽霞

    2012-01-01

    以活性炭为载体,通过浸渍法制备了H9P2W15V3/C催化剂,对催化剂进行FT-IR表征。以催化1,4-丁二醇脱水制备四氢呋喃为探针反应,考察催化剂的酸催化性能。通过正交实验得出了最佳条件反应:w(催化剂)=3.93%(相对1,4丁二醇质量),反应温度为185~190℃,反应时间为40 min,四氢呋喃平均收率达93.30%,催化剂重复使用3次,产率仍可达90.94%。本工艺具有绿色、安全、操作简单、收率高等优点。%Tungstovanadophosphoric heteropoly acid with tri-vanadium-substituted Dawson structure supported by activated carbon was prepared by impregnation method and characterized by IR. Its catalytic performance was studied in the catalytic synthesis of tetrahydrofuran from 1,4-butanediol. The optimal reaction condition was obtained by orthogonal experiments as mass ratio of 1,4-butanediol to catalyst 100 : 3.93, reaction temperature 185--190 ~C and reaction time 40 rain, under which, the yield of tetrahydrofuran reached 93.30%. The catalyst could be reused for 3 times and the yield was still above 90.94%. This approach provides a green, safe, operation simple and highly active dehydration process to produce THF.

  6. 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.

  7. Efficient reduction of the formation of by-products and improvement of production yield of 2,3-butanediol by a combined deletion of alcohol dehydrogenase, acetate kinase-phosphotransacetylase, and lactate dehydrogenase genes in metabolically engineered Klebsiella oxytoca in mineral salts medium.

    Science.gov (United States)

    Jantama, Kaemwich; Polyiam, Pattharasedthi; Khunnonkwao, Panwana; Chan, Sitha; Sangproo, Maytawadee; Khor, Kirin; Jantama, Sirima Suvarnakuta; Kanchanatawee, Sunthorn

    2015-07-01

    Klebsiella oxytoca KMS005 (∆adhE∆ackA-pta∆ldhA) was metabolically engineered to improve 2,3-butanediol (BDO) yield. Elimination of alcohol dehydrogenase E (adhE), acetate kinase A-phosphotransacetylase (ackA-pta), and lactate dehydrogenase A (ldhA) enzymes allowed BDO production as a primary pathway for NADH re-oxidation, and significantly reduced by-products. KMS005 was screened for the efficient glucose utilization by metabolic evolution. KMS005-73T improved BDO production at a concentration of 23.5±0.5 g/L with yield of 0.46±0.02 g/g in mineral salts medium containing 50 g/L glucose in a shake flask. KMS005-73T also exhibited BDO yields of about 0.40-0.42 g/g from sugarcane molasses, cassava starch, and maltodextrin. During fed-batch fermentation, KMS005-73T produced BDO at a concentration, yield, and overall and specific productivities of 117.4±4.5 g/L, 0.49±0.02 g/g, 1.20±0.05 g/Lh, and 27.2±1.1 g/gCDW, respectively. No acetoin, lactate, and formate were detected, and only trace amounts of acetate and ethanol were formed. The strain also produced the least by-products and the highest BDO yield among other Klebsiella strains previously developed.

  8. 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.

  9. 含Zn2+的金属有机骨架材料对碳酸二苯酯与1,4-丁二醇酯交换反应的催化性能%Transesterification Between Diphenyl Carbonate and 1,4-Butanediol Catalyzed by Metal-Organic Framework Based on Zn2 +

    Institute of Scientific and Technical Information of China (English)

    王丽苹; 王公应; 汪帆; 刘品华; 徐晓林; 贺池先

    2013-01-01

    采用溶剂热法制备了Zn2+和对苯二甲酸组合形成的金属有机骨架材料(MOF),并用X射线衍射(XRD)和红外光谱(FT-IR)对其进行了表征.研究了MOF对碳酸二苯酯(DPC)与1,4-丁二醇(1,4-BD)酯交换反应合成聚碳酸酯二醇(PCDL)的催化活性,并与乙酰丙酮氧钛(TiO(acac)2)、乙酰丙酮锌(Zn(acac)2)和锌铝类水滑石(Zn-Al-CO3 LDH)等催化剂进行了比较.结果显示,MOF是该酯交换反应的良好催化剂.在优化的反应条件下,获得了数均分子量为3470,羟基值为35.2mg KOH/g的PCDL.%Metal-organic framework (MOF) based on Zn2+ and terephthalic acid was prepared and characterized with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The catalytic activity of MOF for the transesterification between diphenyl carbonate (DPC) and 1,4-butanediol (1,4-BD) to polycarbonate diol (PCDL) was investigated, and was compared with that of catalysts such as titaniumoxide acetylacetonate (TiO(acac)2), zinc acetylacetonate (Zn(acac)2) and Zn-Al-CO3 layered double hydroxides (Zn-Al-CO3 LDH). The results show that MOF is an efficient catalyst for the transesterification. Under optimal reaction conditions, PCDL with number average molecular weight (-Mn) of 3470 and hydroxyl value of 35.2 mg KOH/g was synthesized.

  10. 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.

  11. Transesterification Kinetics of Dimethyl Terephthalate with 1,4-Butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Impyo; Lee, Jinhong; Jo, Sanhwan; Cho, Minjung; Han, Myungwan [Chungnam National University, Daejeon (Korea, Republic of); Kang, Kyungsuk [Siontech, Daejeon (Korea, Republic of)

    2013-02-15

    PBT (polybutylene terephthalate) has excellent mechanical properties such as low absorption, dimensional stability, abrasion resistance. It is used in manufacturing electronic components, the automobile part and the various precise parts. Bis (hydroxybutyl) terephthalate (BHBT) which is a PBT monomer, can be produced by transesterification reaction of DMT (dimethyl terephthalate) with 1,4-butandiol (BD). The kinetics of transesterification reaction of DMT with BD using zinc acetate as a catalyst was studied in a batch reactor. Previous kinetic studies was carried out in a semibatch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the transesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous models was obtained and found to have a good agreement between model predictions and experimental data.

  12. 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.

  13. 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.

  14. Acetoin and 2,3 butanediol isomers synthesis in metabolically engineeredLactococcus lactis

    DEFF Research Database (Denmark)

    Kandasamy, Vijayalakshmi; Liu, Jianming; Dantoft, Shruti Harnal

    )-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBdh from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production...... of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32.1g....../L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added...

  15. Simultaneous production of isopropanol, butanol, ethanol and 2,3-butanediol by Clostridium acetobutylicum ATCC 824 engineered strains.

    OpenAIRE

    Collas, Florent; Kuit, Wouter; Clément, Benjamin; Marchal, Rémy; López-Contreras, Ana M.; Monot, Frederic

    2012-01-01

    International audience; Isopropanol represents a widely-used commercial alcohol which is currently produced from petroleum. In nature, isopropanol is excreted by some strains of Clostridium beijerinckii, simultaneously with butanol and ethanol during the isopropanol butanol ethanol (IBE) fermentation. In order to increase isopropanol production, the gene encoding the secondary-alcohol dehydrogenase enzyme from C. beijerinckii NRRL B593 (adh) which catalyzes the reduction of acetone to isoprop...

  16. Simultaneous production of isopropanol, butanol, ethanol and 2,3-butanediol by Clostridium acetobutylicum ATCC 824 engineered strains

    NARCIS (Netherlands)

    Collas, Florent; Kuit, Wouter; Clément, Benjamin; Marchal, Rémy; López-contreras, Ana M.; Monot, Frederic

    2012-01-01

    Isopropanol represents a widely-used commercial alcohol which is currently produced from petroleum. In nature, isopropanol is excreted by some strains of Clostridium beijerinckii, simultaneously with butanol and ethanol during the isopropanol butanol ethanol (IBE) fermentation. In order to increase

  17. 1,4-丁二醇生产技术进展%Progress in Production Technology of 1,4-Butanediol

    Institute of Scientific and Technical Information of China (English)

    王俐

    2001-01-01

    @@ 1,4-丁二醇(BDO)除作为生产四氢呋喃(THF)和γ-丁内酯(GBL)的原料外,主要用于生产聚对苯二甲酸丁二醇酯(PBT).近年来,该领域涌现出大量新工艺和新的生产厂商.

  18. 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

  19. Mutation and Screening of Enterobacter aerogenes for the Production of 2,3-butanediol%产2,3-丁二醇的产气肠杆菌株的诱变和筛选

    Institute of Scientific and Technical Information of China (English)

    赵世敏; 严群; 阮文权; 邹华

    2008-01-01

    以产气肠杆菌为原始菌株,采用紫外线、亚硝基胍复合诱变进行诱变育种,以产酸圈和产物耐受相结合的筛选方法,获得了1株高产2,3-丁二醇的优良突变菌株,其产量达到24.20 g/L,比原始菌株(6.28 g/L)提高了3.8倍,且遗传性质稳定.该诱变方法和筛选方法目标明确,易操作,对于其他具有工业应用价值菌株的筛选有一定的借鉴意义.

  20. D194 G突变对meso-2,3-丁二醇脱氢酶催化特性的影响%Effects of D194G Mutant on meso-2, 3-Butanediol Dehydrogenase Catalytic Properties

    Institute of Scientific and Technical Information of China (English)

    郝文博; 姬芳玲; 王静云; 张悦; 王天琪; 车文实; 包永明

    2016-01-01

    目的:比较来源于Enterobacter aerogenes CICC10293和Bacillus subtilis的meso-2,3-丁二醇脱氢酶(E.a-BDH和D194G B.s-BDH)活性和动力学参数,分析D194氨基酸对BDH催化特性的影响.方法:利用E.coli BL21(DE3)原核表达E.a-BDH和D194GB.s-BDH,经HiTrap Q FF阴离子交换柱和Superdex 75凝胶柱纯化后,用MALDI-TOF MS确定其分子质量;检测NADH/NAD+氧化还原的吸光度变化确定BDH活性、辅酶和底物的特异性、最适pH、温度及动力学参数.结果:重组表达E.a-BDH和D194G B.s-BDH是同源四聚体蛋白,基因序列有两处碱基不同(g.27A/T和g.581A/G),其中g.581A/G导致BDH的一处氨基酸发生改变(p.D194G).D194G B.s-BDH的活性约为E.a-BDH的2.3%,并且丧失了氧化meso-2,3-丁二醇的能力.二者均以乙偶姻/NADH为最适底物,但D194G B.s-BDH的Km是E.a-BDH的5.63倍.结论:D194G氨基酸突变降低了BDH的活性.

  1. (2R,3R)-丁二醇脱氢酶的体外重组表达%Recombinant Expression of(2R,3R)-Butanediol Dehydrogenase in Vitro

    Institute of Scientific and Technical Information of China (English)

    罗雅婧; 严陶陶

    2015-01-01

    ObjectiveTo establish how 2,3-BDH possesse differential stereo specificities.Methods The gene of(2R,3R)-BDH amplified from the genome of Bacillus subtilis,and was inserted into pMD18-T vector for sequencing. The constructed recombinant expression vector was sequenced, and the result of this experiment was compared with the known sequence to construct evolutionary tree.ResultsSoluble expression of the recombinant plasmid was obtained in the recombinant bacteria.Conclusion (2R,3R)-BDH was obtained by induced expression in recombinant bacteria.%目的:明确2,3-丁二醇脱氢酶(2,3-BDH)如何具有不同的立体定向性。方法从枯草芽孢杆菌中克隆出(2R,3R)-丁二醇脱氢酶基因,将克隆的目的基因导入pMD18-T载体中,构建的重组质粒经测序后,将本实验序列和已发表序列进行比对分析,构建进化树。结果重组质粒可在重组菌中获得可溶性表达。结论利用重组菌株诱导表达获得了(2R,3R)-丁二醇脱氢酶。

  2. 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.

  3. Biobutanediol-mediated liquefaction of empty fruit bunch saccharification residues to prepare lignin biopolyols.

    Science.gov (United States)

    Lee, Jae Hoon; Lee, Eun Yeol

    2016-05-01

    Saccharification residue from empty fruit bunch (EFB) was liquefied with bio-butanediol to produce lignin biopolyols for the preparation of biopolyurethane. To substitute petroleum-derived polyhydric alcohols, butanediol isomers (1,4-butanediol, levo-2,3-bio-butanediol, and meso-2,3-bio-butanediol) or PEG#400-blended butanediol isomers were used as liquefaction solvents in the presence of sulfuric acid catalyst. Lignin biopolyols with a conversion of 63.3%, a hydroxyl number of 582.7 mg KOH/g and an acid number of 21.7 mg KOH/g were obtained under the optimal condition consisting of 25% biomass loading, 3% acid loading, and a temperature of 150°C for 120 min when liquefied with 1,4-butanediol/PEG#400 blended solvent (9/1, w/w). When the levo-2,3-bio-butanediol solvent was used in the absence of PEG#400, the highest conversion, 68.9%, was obtained. Lignin biopolyol-based biopolyurethanes were synthesized with toluene diisocyanate. FT-IR analysis revealed that EFB lignin biopolyols liquefied with bio-butanediols were suitable monomers for the preparation of biopolyurethane.

  4. Catalytic activity of carbon-based solid acids in the esterification synthesis of 1,4-butanediol disuccinate diisooctyl%碳基固体酸在1,4-丁二醇双琥珀酸二异辛酯合成中的催化性能

    Institute of Scientific and Technical Information of China (English)

    华平; 喻红梅; 李建华; 方略韬; 戴宝江; 张海滨; 朱国华

    2016-01-01

    采用对甲苯磺酸和可溶性淀粉混合物部分炭化制备新型碳基固体酸催化剂,研究了m(对甲苯磺酸):m(可溶性淀粉)、炭化温度和炭化时间对催化剂催化合成1,4-丁二醇双琥珀酸二异辛酯的影响,用SEM、XRD、红外光谱、元素分析等对催化剂进行了表征。结果表明,在m(对甲苯磺酸):m(可溶性淀粉)=1.0:2.0、炭化温度200℃、炭化时间8 h的条件下,得到碳基固体酸的催化活性最高,在180℃下反应1.5 h可达到规定的酯化率,催化剂重复使用5次后,酯化率仍能达到93%以上,另外该催化剂具有良好的热稳定性。%Carbon-based solid acids were prepared by coking mixtures of p-toluene sulfonic acid and soluble starch with different ratios at different temperatures. The effects of the p-toluene sulfonic acid/soluble starch mass ratio, coking temperature and time on their catalytic activities in the esterification reaction of maleic anhydride with ethylene glycol were investigated. Results indicated that the activity of the acid was the highest when amixture with the mass ratio of 0. 5 was coked at 200℃ for 8 h. The activity remained high after the solid acid had been used 5 times.

  5. 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.

  6. 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%.

  7. 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.

  8. 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

  9. Genome-wide Escherichia coli stress response and improved tolerance towards industrially relevant chemicals

    DEFF Research Database (Denmark)

    Rau, Martin Holm; Calero Valdayo, Patricia; Lennen, Rebecca

    2016-01-01

    , hydroxy-γ-butyrolactone, 1,4-butanediol, furfural), organic acids (acetate, itaconic acid, levulinic acid, succinic acid), amino acids (serine, threonine) and membrane-intercalating chemicals (decanoic acid, geraniol). The transcriptional response towards these chemicals revealed large overlaps...

  10. Glucose kinetics, plasma metabolites, and endocrine responses during experimental ketosis in steers.

    Science.gov (United States)

    Lyle, R R; deBoer, G; Mills, S E; Russell, R W; Beitz, D C; Young, J W

    1984-10-01

    Phlorizin and 1,3-butanediol were used to determine effects of glucosuria and ketonemia on concentrations of metabolites in blood plasma and on kinetics of glucose metabolism. Four steers received four treatments (control; control plus dietary 1,3-butanediol; control plus phlorizin injections; and control plus phlorizin and 1,3-butanediol) in a Latin square design. Treatments lasted 14 days. All steers received a 30% grain, 70% forage ration in equal meals every 2 h. Metabolite concentrations in blood plasma and urine and glucose kinetics were measured on each of the last 3 days of each treatment period. Phlorizin caused glucosuria; decreased plasma glucose, glucose total entry rate, and glucose recycling; and increased plasma free fatty acids and glucose irreversible loss. Glucose pool size was increased by 1,3-butanediol. Phlorizin plus 1,3-butanediol caused glucosuria and ketonuria; decreased plasma glucose; and increased blood ketone bodies, plasma free fatty acids, glucose irreversible loss, and glucose pool size. Growth hormone, insulin, and glucagon were not affected by treatment. Physiological perturbations in these steers were characteristic of some of those in ketotic cows.

  11. 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.

  12. 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.

  13. 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.

  14. The metabolic flux regulation of Klebsiella pneumoniae based on quorum sensing system

    Science.gov (United States)

    Sun, Shujing; Zhang, Haiyang; Lu, Shuyi; Lai, Chunfen; Liu, Huijun; Zhu, Hu

    2016-01-01

    Quorum-sensing (QS) systems exist universally in bacteria to regulate multiple biological functions. Klebsiella pneumoniae, an industrially important bacterium that produces bio-based chemicals such as 2,3-butanediol and acetoin, can secrete a furanosyl borate diester (AI-2) as the signalling molecule mediating a QS system, which plays a key regulatory role in the biosynthesis of secondary metabolites. In this study, the molecular regulation and metabolic functions of a QS system in K. pneumoniae were investigated. The results showed that after the disruption of AI-2-mediated QS by the knockout of luxS, the production of acetoin, ethanol and acetic acid were relatively lower in the K. pneumoniae mutant than in the wild type bacteria. However, 2,3-butanediol production was increased by 23.8% and reached 54.93 g/L. The observed enhancement may be attributed to the improvement of the catalytic activity of 2,3-butanediol dehydrogenase (BDH) in transforming acetoin to 2,3-butanediol. This possibility is consistent with the RT-PCR-verified increase in the transcriptional level of budC, which encodes BDH. These results also demonstrated that the physiological metabolism of K. pneumoniae was adversely affected by a QS system. This effect was reversed through the addition of synthetic AI-2. This study provides the basis for a QS-modulated metabolic engineering study of K. pneumoniae. PMID:27924940

  15. 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 (Julian)

    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

  16. Simultaneous determination of gamma-Hydroxybutyrate (GHB) and its analogues (GBL, 1.4-BD, GVL) in whole blood and urine by liquid chromatography coupled to tandem mass spectrometry

    DEFF Research Database (Denmark)

    Johansen, Sys Stybe; Windberg, Charlotte Norup

    2011-01-01

    A simple liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for simultaneous identification and quantification of ¿-hydroxybutyrate (GHB), ¿-butyrolactone (GBL), 1.4-butanediol (1.4-BD), and ¿-valerolactone (GVL) in whole blood from forensic cases...

  17. Synthesis and properties of poly(butylene terephthalate)-b-polyisobutylene segmented block copolymers

    NARCIS (Netherlands)

    Walch, E.; Gaymans, R.J.

    1994-01-01

    Segmented block copolymers of polyisobutylene (PIB) and poly(butylene terephthalate) (PBT) were made by condensation polymerization of α,θ-di-anhydride telechelic PIB, with 1,4-butanediol and dimethyl terephthalate. The inherent viscosity of the polymers was between 0.35 and 2.0 dl g−1. The extracta

  18. 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

  19. 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.

  20. Immunochemical properties of NAD+-linked glycerol dehydrogenases from Escherichia coli and Klebsiella pneumoniae.

    OpenAIRE

    Tang, J C; Forage, R G; Lin, E C

    1982-01-01

    An NAD+-linked glycerol dehydrogenase hyperproduced by a mutant of Escherichia coli K-12 was found to be immunochemically homologous to a minor glycerol dehydrogenase of unknown physiological function in Klebsiella pneumoniae 1033, but not to the glycerol dehydrogenase of the dha system responsible for anaerobic dissimilation of glycerol or to the 2,3-butanediol dehydrogenase of K. pneumoniae.

  1. Physical and monolayer film properties of potential fatty ester biolubricants

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Linxing [Iowa State University; Hammond, Earl G [Iowa State University; Wang, Tong [Iowa State University; Bu, Wei [Ames Laboratory; Vaknin, David [Ames Laboratory

    2014-04-03

    The desire to replace petroleum-based lubricants with alternatives that are environmentally friendly and made from sustainable sources has encouraged the development of biolubricants based on vegetable oils. To be good lubricants, the materials should have low melting points, appropriate viscosity and oxidative stability. In this paper, we report the melting point and viscosity of oleate esters of ethylene glycol, 1,2-propanediol, 2,3-butanediol, and pentaerythritol as well as the decanoate esters of 2,3-butanediol and the 12-methyltetradecanoate esters of 1,2-propanediol. Polyol esters that have a free hydroxy group had lower melting points than the completely esterified polyols, but the completely esterified polyol esters exhibited less change in viscosity with temperature than those having a free hydroxy group. 2, 3-Butanediol monooleate, which melted at -48.6°C shows promise as a biolubricant, but its viscosity index was estimated to be 100. Pentaerythritol oleate esters, with melting points below -10°C and viscosity indices in the range of 170–197, may be suitable candidates as biolubricants. The behavior of esters spread as a monomolecular film at air/water interface may provide insight into the way they behave when spread on metal or polar surfaces, so the pressure-area isotherms of 2,3-butanediol monoleate and selected esters are also reported.

  2. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Does, van der L.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal p

  3. Production and characterization of poly(3-hydroxypropionate-co-4-hydroxybutyrate) with fully controllable structures by recombinant Escherichia coli containing an engineered pathway

    DEFF Research Database (Denmark)

    Meng, De-Chuan; Shi, Zhen-Yu; Wu, Lin-Ping

    2012-01-01

    ) and 1,4-butanediol (BDO), compositions of 4HB in microbial P(3HP-co-4HB) were controllable ranging from 12 mol% to 82 mol% depending on PDO/BDO ratios. Nuclear magnetic resonance (NMR) spectra clearly indicated the polymers were random copolymers of 3HP and 4HB. Their mechanical and thermal properties...

  4. Incorporation of different crystallizable amide blocks in segmented poly(ester amide)s

    NARCIS (Netherlands)

    Lips, P.A.M.; Broos, R.; Heeringen, van M.J.M.; Dijkstra, P.J.; Feijen, J.

    2005-01-01

    High molecular weight segmented poly(ester amide)s were prepared by melt polycondensation of dimethyl adipate, 1,4-butanediol and a symmetrical bisamide-diol based on ε-caprolactone and 1,2-diaminoethane or 1,4-diaminobutane. FT-IR and WAXD analysis revealed that segmented poly(ester amide)s based

  5. 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

  6. Aspen Plus异丁醇-水萃取精馏过程的模拟计算%Simulation and calculation of extractive distillation process of Iso-butanol-water system using Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    周文; 黄雪莉

    2011-01-01

    借助Aspen Plus,对异丁醇-水体系萃取精馏过程所用的溶剂1,4-丁二醇、1,3-丁二醇、1,3-丙二醇、1,2-丙二醇、甘油、乙二醇等进行了模拟计算,确定分离能力大小的顺序为:1,4-丁二醇>甘油>乙二醇>1,2-丙二醇>1,3-丙二醇>1,3-丁二醇.在此基础上,以1,4-丁二醇为萃取剂,对该体系的萃取精馏过程进行了模拟计算,确定了萃取精馏过程的最佳工艺操作条件,并在此条件下获得质量浓度高达99.75%的异丁醇产品.为异丁醇-水萃取精馏分离工艺工业化提供了理论依据和设计参考.%With Aspen Plus software, extraction solvents,1,4-butanediol,l,3-butanediol, 1,2-propanediol, 1,3- propanediol, glycerol and ethylene-clycol, were investigated for the process of extractive distillation of isobutanol- water system. The ability of separation is: l,4-butanediol>Glycerol> ethylene glycol>l,2-propanediol>l,3- propanediol>l,3-butanediol, and 1,4-butanediol is the best extraction solvent. On this basis, with 1,4-butanediol for extraction solvent of the system, simulation and optimization! Were carried out for the process of extractive distillation to determine the optimum operation Conditions, under which the concentration of the isobutanol product was up to 99.75%. These works will provide a theory basis and design reference for the industrialization of the extractive distillation separation of isobutanol- water system.

  7. 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.

  8. 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.

  9. Preparation with laser ablation and photoluminescence of Y3Al5O12:Ce nanophosphors

    Science.gov (United States)

    Cho, Young-Sik; Huh, Young-Duk; Park, Chan Ryang; Do, Young Rag

    2014-03-01

    We prepared Y3Al5O12:Ce (YAG:Ce) nanophosphors with a mean size of 15 nm by using laser ablation of micron-sized commercial YAG:Ce target phosphor in 1,4-butanediol. The photoluminescence properties of the YAG:Ce nanophosphors were compared with those of micron-sized YAG:Ce phosphor. The elimination of back-scattering effect was confirmed by the optical properties of the YAG:Ce nanophosphors. The thermal stability of the YAG:Ce nanophosphors was also examined for the use of high power white LED. We convinced that the laser ablation method in 1,4-butanediol is an adequate method for the preparation of YAG:Ce nanophosphors for high power white LED with enhancement of the transmittance of the blue light from the InGaN chip.

  10. Acquisition of Heat Stable Enzymes from Thermophilic Microorganisms: Peroxidases, Ureases, and Glucose Oxidases.

    Science.gov (United States)

    1992-04-01

    galactonic acid lactone N N N phenylethylamine N N N D-galacturonic acid N N 9 putrescine N N N D-gluconic acid N N N 2-amino ethanol N N N D...58 N N N phenylethylanew N N N - N N N putrescine N N N N N N 2-amino ethanol N N N N N N 2,3-butanediol N N 29 N N N glycerol N N N N N N D,L-a...41 N N 53 thymidine N N 53 N N 59 phenylethylarnine N N N N N N putrescine N N N N N N 2-amino ethanol N N N N N N 2,3-butanediol N N 35 39 N 52

  11. Engineering an Obligate Photoautotrophic Cyanobacterium to Utilize Glycerol for Growth and Chemical Production.

    Science.gov (United States)

    Kanno, Masahiro; Atsumi, Shota

    2017-01-20

    Cyanobacteria have attracted much attention as a means to directly recycle carbon dioxide into valuable chemicals that are currently produced from petroleum. However, the titers and productivities achieved are still far below the level required in industry. To make a more industrially applicable production scheme, glycerol, a byproduct of biodiesel production, can be used as an additional carbon source for photomixotrophic chemical production. Glycerol is an ideal candidate due to its availability and low cost. In this study, we found that a heterologous glycerol respiratory pathway enabled Synechococcus elongatus PCC 7942 to utilize extracellular glycerol. The engineered strain produced 761 mg/L of 2,3-butanediol in 48 h with a 290% increase over the control strain under continuous light conditions. Glycerol supplementation also allowed for continuous cell growth and 2,3-butanediol production in diurnal light conditions. These results highlight the potential of glycerol as an additional carbon source for photomixotrophic chemical production in cyanobacteria.

  12. Global metabolic rewiring for improved CO2 fixation and chemical production in cyanobacteria

    Science.gov (United States)

    Kanno, Masahiro; Carroll, Austin L.; Atsumi, Shota

    2017-03-01

    Cyanobacteria have attracted much attention as hosts to recycle CO2 into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2 fixation and increase chemical production. We introduce modifications in glycolytic pathways and the Calvin Benson cycle to increase carbon flux and redirect it towards carbon fixation. The engineered strain efficiently uses both CO2 and glucose, and produces 12.6 g l-1 of 2,3-butanediol with a rate of 1.1 g l-1 d-1 under continuous light conditions. Removal of native regulation enables carbon fixation and 2,3-butanediol production in the absence of light. This represents a significant step towards industrial viability and an excellent example of carbon metabolism plasticity.

  13. 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.

  14. Networks 90: Polymer Networks Group Meeting (10th) and IUPAC international Symposium on Polymer Networks (10th) Held in Jerusalem on 20-25 May 1990. Programme and Abstracts

    Science.gov (United States)

    1990-05-25

    at the ambient temperatureI (T) and pressure (p); pu, is the "contribution’ of the network to u,; q is the degree of swelling, which equals 1i/ where...Antonio Rey and Walther Burcharda) a) Institute of Macromolecular Chemistry, University of Freiburg 7800 Freiburg, FRG b) Departimento di Quimica Fisica...Ingenieria Quimica , 12 de octubre 1842, 8000 Bahia Blanca, Argentina. P-36 BRANCHING KINETICS OF EPOXY POLYMERIZATION OF 1,4-BUTANEDIOL DIGLYCIDYL ETHER

  15. 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.

  16. Biologically produced succinic acid: A new route to chemical intermediates

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The national laboratory consortium has undertaken an R&D project with the Michigan Biotechnology Institute (MBI) to demonstrate the feasibility of producing a chemical intermediate, succinic acid, and various derivatives, from renewable agricultural resources. The projects near-term goal is to demonstrate an economically competetive process for producing 1,4-butanediol and other derivatives from biologically produced succinic acid without generating a major salt waste. The competitiveness to the petrochemical process must be demonstrated.

  17. 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

  18. Abnormal Metabolite in Alcoholic Subjects,

    Science.gov (United States)

    1982-01-01

    coated with 3Z Carbowax 20 M. Serum proteins were removed by precipitation with 0.5 M percholoric acid. The clear, protein -free supernatant was...this study included alcoholic hepatitis or cirrhosis of the liver in 29. of the alcoholic subjects; diabetes mellitus in 8 and Korsakoff’s syndrome in 6...no ethanol, and who according to the history had been two days without any alcohol intake . DISCUSSION The source of the 2,3-butanediol found in the

  19. 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.

  20. Cofactor engineering through heterologous expression of an NADH oxidase and its impact on metabolic flux redistribution in Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Ji Xiao-Jun

    2013-01-01

    Full Text Available Abstract Background Acetoin is an important bio-based platform chemical. However, it is usually existed as a minor byproduct of 2,3-butanediol fermentation in bacteria. Results The present study reports introducing an exogenous NAD+ regeneration sysytem into a 2,3-butanediol producing strain Klebsiella pneumoniae to increse the accumulation of acetoin. Batch fermentation suggested that heterologous expression of the NADH oxidase in K. pneumoniae resulted in large decreases in the intracellular NADH concentration (1.4 fold and NADH/NAD+ ratio (2.0 fold. Metabolic flux analysis revealed that fluxes to acetoin and acetic acid were enhanced, whereas, production of lactic acid and ethanol were decreased, with the accumualation of 2,3-butanediol nearly unaltered. By fed-batch culture of the recombinant, the highest reported acetoin production level (25.9 g/L by Klebsiella species was obtained. Conclusions The present study indicates that microbial production of acetoin could be improved by decreasing the intracellular NADH/NAD+ ratio in K. pneumoniae. It demonstrated that the cofactor engineering method, which is by manipulating the level of intracellular cofactors to redirect cellular metabolism, could be employed to achieve a high efficiency of producing the NAD+-dependent microbial metabolite.

  1. Low molecular weight gelators based on biosurfactants, cellobiose lipids by Cryptococcus humicola.

    Science.gov (United States)

    Imura, Tomohiro; Kawamura, Daisuke; Ishibashi, Yuko; Morita, Tomotake; Sato, Shun; Fukuoka, Tokuma; Kikkawa, Yoshihiro; Kitamoto, Dai

    2012-01-01

    Cellobiose lipids (CLs) are bolaform glycolipid biosurfactants, which are produced from natural resources by a yeast strain and show fungicidal activity. In this study, the gelation properties of CL in solvents were investigated by several techniques including rheology and atomic force microscopy (AFM). The yeast CL was found to gelate 6 out of 26 solvents. Although it did not provide gels in ethanol or 1, 3-butanediol which are widely used for cosmetic industries, we succeeded in producing gels by mixing ethanol or 1, 3-butanediol with water. AFM observation of the gels on a silicon substrate provided 3D supramolecular structures with an entangled fibrous network. Moreover, it was also found that some of fibrous structures were twisted helical ribbons. This should be due to the cellobiose backbone having several chiral functional groups. The sol-gel phase transition temperatures for gels in mixed ethanol/water and 1, 3-butanediol/water systems were below 100°C, indicating that the gels can be obtained with rather mild preparation conditions. The present CL gels would be useful for novel multifunctional materials applicable to various industries.

  2. 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.

  3. A novel whole-cell biocatalyst with NAD+ regeneration for production of chiral chemicals.

    Directory of Open Access Journals (Sweden)

    Zijun Xiao

    Full Text Available BACKGROUND: The high costs of pyridine nucleotide cofactors have limited the applications of NAD(P-dependent oxidoreductases on an industrial scale. Although NAD(PH regeneration systems have been widely studied, NAD(P(+ regeneration, which is required in reactions where the oxidized form of the cofactor is used, has been less well explored, particularly in whole-cell biocatalytic processes. METHODOLOGY/PRINCIPAL FINDINGS: Simultaneous overexpression of an NAD(+ dependent enzyme and an NAD(+ regenerating enzyme (H(2O producing NADH oxidase from Lactobacillus brevis in a whole-cell biocatalyst was studied for application in the NAD(+-dependent oxidation system. The whole-cell biocatalyst with (2R,3R-2,3-butanediol dehydrogenase as the catalyzing enzyme was used to produce (3R-acetoin, (3S-acetoin and (2S,3S-2,3-butanediol. CONCLUSIONS/SIGNIFICANCE: A recombinant strain, in which an NAD(+ regeneration enzyme was coexpressed, displayed significantly higher biocatalytic efficiency in terms of the production of chiral acetoin and (2S,3S-2,3-butanediol. The application of this coexpression system to the production of other chiral chemicals could be extended by using different NAD(P-dependent dehydrogenases that require NAD(P(+ for catalysis.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Genome sequence of the plant growth promoting endophytic bacterium Enterobacter sp. 638.

    Directory of Open Access Journals (Sweden)

    Safiyh Taghavi

    2010-05-01

    Full Text Available Enterobacter sp. 638 is an endophytic plant growth promoting gamma-proteobacterium that was isolated from the stem of poplar (Populus trichocarpaxdeltoides cv. H11-11, a potentially important biofuel feed stock plant. The Enterobacter sp. 638 genome sequence reveals the presence of a 4,518,712 bp chromosome and a 157,749 bp plasmid (pENT638-1. Genome annotation and comparative genomics allowed the identification of an extended set of genes specific to the plant niche adaptation of this bacterium. This includes genes that code for putative proteins involved in survival in the rhizosphere (to cope with oxidative stress or uptake of nutrients released by plant roots, root adhesion (pili, adhesion, hemagglutinin, cellulose biosynthesis, colonization/establishment inside the plant (chemiotaxis, flagella, cellobiose phosphorylase, plant protection against fungal and bacterial infections (siderophore production and synthesis of the antimicrobial compounds 4-hydroxybenzoate and 2-phenylethanol, and improved poplar growth and development through the production of the phytohormones indole acetic acid, acetoin, and 2,3-butanediol. Metabolite analysis confirmed by quantitative RT-PCR showed that, the production of acetoin and 2,3-butanediol is induced by the presence of sucrose in the growth medium. Interestingly, both the genetic determinants required for sucrose metabolism and the synthesis of acetoin and 2,3-butanediol are clustered on a genomic island. These findings point to a close interaction between Enterobacter sp. 638 and its poplar host, where the availability of sucrose, a major plant sugar, affects the synthesis of plant growth promoting phytohormones by the endophytic bacterium. The availability of the genome sequence, combined with metabolome and transcriptome analysis, will provide a better understanding of the synergistic interactions between poplar and its growth promoting endophyte Enterobacter sp. 638. This information can be further

  9. 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).

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. Gas Fermentation using Thermophilic Moorella Species for production of Biochemicals

    DEFF Research Database (Denmark)

    Redl, Stephanie Maria Anna

    fermentation processes that are nearly on commercial level, mesophilic acetogens are used to mainly produce ethanol and butanediol. However, thermophilic acetogens, such as Moorella thermoacetica would allow for easy downstream processing when producing volatile products such as acetone. This thesis starts...... with a review of the feedstock potential for gas fermentation and how thermophilic production strains as well as unconventional fermentation processes such as mixotrophy can help to exploit this potential. I analyzed a process with respect to thermodynamic and economic considerations, in which acetone......, this thesis describes several projects which help to pave the way for biochemical production with the thermophile M. thermoacetica on in an economically competitive way....

  15. 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.

  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

    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. Atom-Specific Identification of Adsorbed Chiral Molecules by Photoemission

    Science.gov (United States)

    Kim, J. W.; Carbone, M.; Dil, J. H.; Tallarida, M.; Flammini, R.; Casaletto, M. P.; Horn, K.; Piancastelli, M. N.

    2005-09-01

    The study of chiral adsorbed molecules is important for an analysis of enantioselectivity in heterogeneous catalysis. Here we show that such molecules can be identified through circular dichroism in core-level photoemission arising from the chiral carbon atoms in stereoisomers of 2,3-butanediol molecules adsorbed on Si(100), using circularly polarized x rays. The asymmetry in the carbon 1s intensity excited by right and left circularly polarized light is readily observed, and changes sign with the helicity of the radiation or handedness of the enantiomers; it is absent in the achiral form of the molecule. This observation demonstrates the possibility of determining molecular chirality in the adsorbed phase.

  18. DEVELOPMENT OF BIOSURFACTANT-MEDIATED OIL RECOVERY IN MODEL POROUS SYSTEMS AND COMPUTER SIMULATIONS OF BIOSURFACTANT-MEDIATED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; S.K. Maudgalya; R. Knapp; M. Folmsbee

    2004-05-31

    Current technology recovers only one-third to one-half of the oil that is originally present in an oil reservoir. Entrapment of petroleum hydrocarbons by capillary forces is a major factor that limits oil recovery (1, 3, 4). Hydrocarbon displacement can occur if interfacial tension (IFT) between the hydrocarbon and aqueous phases is reduced by several orders of magnitude. Microbially-produced biosurfactants may be an economical method to recover residual hydrocarbons since they are effective at low concentrations. Previously, we showed that substantial mobilization of residual hydrocarbon from a model porous system occurs at biosurfactant concentrations made naturally by B. mojavensis strain JF-1 if a polymer and 2,3-butanediol were present (2). In this report, we include data on oil recovery from Berea sandstone experiments along with our previous data from sand pack columns in order to relate biosurfactant concentration to the fraction of oil recovered. We also investigate the effect that the JF-2 biosurfactant has on interfacial tension (IFT). The presence of a co-surfactant, 2,3-butanediol, was shown to improve oil recoveries possibly by changing the optimal salinity concentration of the formulation. The JF-2 biosurfactant lowered IFT by nearly 2 orders of magnitude compared to typical 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. Tertiary oil recovery experiments showed that biosurfactant solutions with concentrations ranging from 10 to 60 mg/l in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of the residual oil present in Berea sandstone cores. When PHPA was used alone, about 10% of the residual oil was recovered. Thus, about 10% of the residual oil recovered in these experiments was due to the increase in viscosity of the displacing fluid. Little or no oil was recovered at

  19. Photochromic Properties of 3-Deoxyanthocyanidin Pigments in Nontoxic Solvents.

    Science.gov (United States)

    Yagishita, Yuki; Mihara, Mai; Kohno, Yoshiumi; Shibata, Masashi

    2016-12-01

    The photochromic properties of some naturally occurring 3-deoxyanthocyanidin pigments were investigated in various nontoxic solvents. When luteolinidin, a representative 3-deoxyanthocyanidin, was dissolved in a mixture of weakly acidic water and an organic solvent with a relative permittivity between 20 and 34, it was possible to repeatedly induce coloration via ultraviolet irradiation and decoloration under light-shielded conditions. 1,3-Butanediol and ethanol, which are approved for use in foods, cosmetics, and household goods, were found to be appropriate organic solvents for this process. In addition, we confirmed that other 3-deoxyanthocyanidins, specifically apigeninidin and tricetinidin, which are commonly found in food grains and tea leaves, also exhibit photochromic properties.

  20. 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.

  1. Poly(butylene succinate) and its copolymers: research, development and industrialization.

    Science.gov (United States)

    Xu, Jun; Guo, Bao-Hua

    2010-11-01

    Poly(butylene succinate) (PBS) and its copolymers are a family of biodegradable polymers with excellent biodegradability, thermoplastic processability and balanced mechanical properties. In this article, production of the monomers succinic acid and butanediol, synthesis, processing and properties of PBS and its copolymers are reviewed. The physical properties and biodegradation rate of PBS materials can be varied in a wide range through copolymerization with different types and various contents of monomers. PBS has a wide temperature window for thermoplastic processing, which makes the resin suitable for extrusion, injection molding, thermoforming and film blowing. Finally, we summarized industrialization and applications of PBS.

  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. 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.

  4. 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.

  5. 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.

  6. Influence of the polymerization-mixture composition for monolithic methacrylate-based columns on the electrochromatographic performance of drug molecules.

    Science.gov (United States)

    Tanret, Indiana; Mangelings, Debby; Vander Heyden, Yvan

    2008-09-29

    Methacrylate-based monolithic stationary phases were evaluated for the analysis of drug molecules using capillary electrochromatography (CEC) as separation technique. The effect of the polymerization-mixture composition on the retention behavior of a small test set of mainly drug molecules was studied. Two factors were varied in a central-composite design-based approach: the ratio between the pore-forming solvents and the monomers on one hand, and the ratio within the pore-forming solvents on the other hand, resulting in nine different stationary phases. The central point of the design was chosen at 70% (m/m) pore-forming solvents (PFS) of which 30% (m/m) is 1,4-butanediol, i.e. 21% of the total polymerization mixture. Experiments were conducted using both a basic (pH 11.5) and an acidic (pH 3) mobile phase. Retention times, retention factors, peak asymmetry and number of theoretical plates are the responses used to evaluate the performance of the resulting monoliths. The best compromise between the different responses was found around 67% PFS and 18% 1,4-butanediol (relative to the total mass), i.e. rather close to the center point. At these conditions, retention times were generally below 15min and retention factors below 5. Asymmetry values between close to 1 were found, and theoretical plate numbers up to 10,900, which were improvements compared to the central point of the design.

  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. Biological conversion of gaseous alkenes to liquid chemicals.

    Science.gov (United States)

    Desai, Shuchi H; Koryakina, Irina; Case, Anna E; Toney, Michael D; Atsumi, Shota

    2016-11-01

    Industrial gas-to-liquid (GTL) technologies are well developed. They generally employ syngas, require complex infrastructure, and need high capital investment to be economically viable. Alternatively, biological conversion has the potential to be more efficient, and easily deployed to remote areas on relatively small scales for the utilization of otherwise stranded resources. The present study demonstrates a novel biological GTL process in which engineered Escherichia coli converts C2-C4 gaseous alkenes into liquid diols. Diols are versatile industrially important chemicals, used routinely as antifreeze agents, polymer precursors amongst many other applications. Heterologous co-expression of a monooxygenase and an epoxide hydrolase in E. coli allows whole cell conversion of C2-C4 alkenes for the formation of ethylene glycol, 1,2-propanediol, 1,2-butanediol, and 2,3-butanediol at ambient temperature and pressure in one pot. Increasing intracellular NADH supply via addition of formate and a formate dehydrogenase increases ethylene glycol production titers, resulting in an improved productivity of 9mg/L/h and a final titer of 250mg/L. This represents a novel biological method for GTL conversion of alkenes to industrially valuable diols.

  9. 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.

  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. 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).

  12. 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.

  13. Using slaughterhouse waste in a biochemical-based biorefinery - results from pilot scale tests.

    Science.gov (United States)

    Schwede, Sebastian; Thorin, Eva; Lindmark, Johan; Klintenberg, Patrik; Jääskeläinen, Ari; Suhonen, Anssi; Laatikainen, Reino; Hakalehto, Elias

    2016-09-02

    A novel biorefinery concept was piloted using protein-rich slaughterhouse waste, chicken manure and straw as feedstocks. The basic idea was to provide a proof of concept for the production of platform chemicals and biofuels from organic waste materials at non-septic conditions. The desired biochemical routes were 2,3-butanediol and acetone-butanol fermentation. The results showed that hydrolysis resulted only in low amounts of easily degradable carbohydrates. However, amino acids released from the protein-rich slaughterhouse waste were utilized and fermented by the bacteria in the process. Product formation was directed towards acidogenic compounds rather than solventogenic products due to increasing pH-value affected by ammonia release during amino acid fermentation. Hence, the process was not effective for 2,3-butanediol production, whereas butyrate, propionate, γ-aminobutyrate and valerate were predominantly produced. This offered fast means for converting tedious protein-rich waste mixtures into utilizable chemical goods. Furthermore, the residual liquid from the bioreactor showed significantly higher biogas production potential than the corresponding substrates. The combination of the biorefinery approach to produce chemicals and biofuels with anaerobic digestion of the residues to recover energy in form of methane and nutrients that can be utilized for animal feed production could be a feasible concept for organic waste utilization.

  14. 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.

  15. 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.

  16. The Japan Flavour and Fragrance Materials Association's (JFFMA) safety assessment of acetal food flavouring substances uniquely used in Japan.

    Science.gov (United States)

    Okamura, Hiroyuki; Abe, Hajime; Hasegawa-Baba, Yasuko; Saito, Kenji; Sekiya, Fumiko; Hayashi, Shim-Mo; Mirokuji, Yoshiharu; Maruyama, Shinpei; Ono, Atsushi; Nakajima, Madoka; Degawa, Masakuni; Ozawa, Shogo; Shibutani, Makoto; Maitani, Tamio

    2015-01-01

    Using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), we performed safety evaluations on five acetal flavouring substances uniquely used in Japan: acetaldehyde 2,3-butanediol acetal, acetoin dimethyl acetal, hexanal dibutyl acetal, hexanal glyceryl acetal and 4-methyl-2-pentanone propyleneglycol acetal. As no genotoxicity study data were available in the literature, all five substances had no chemical structural alerts predicting genotoxicity. Using Cramer's classification, acetoin dimethyl acetal and hexanal dibutyl acetal were categorised as class I, and acetaldehyde 2,3-butanediol acetal, hexanal glyceryl acetal and 4-methyl-2-pentanone propyleneglycol acetal as class III. The estimated daily intakes for all five substances were within the range of 1.45-6.53 µg/person/day using the method of maximised survey-derived intake based on the annual production data in Japan from 2001, 2005, 2008 and 2010, and 156-720 µg/person/day using the single-portion exposure technique (SPET), based on the average use levels in standard portion sizes of flavoured foods. The daily intakes of the two class I substances were below the threshold of toxicological concern (TTC) - 1800 μg/person/day. The daily intakes of the three class III substances exceeded the TTC (90 μg/person/day). Two of these, acetaldehyde 2,3-butanediol acetal and hexanal glyceryl acetal, were expected to be metabolised into endogenous products after ingestion. For 4-methyl-2-pentanone propyleneglycol acetal, one of its metabolites was not expected to be metabolised into endogenous products. However, its daily intake level, based on the estimated intake calculated by the SPET method, was about 1/15 000th of the no observed effect level. It was thus concluded that all five substances raised no safety concerns when used for flavouring foods at the currently estimated intake levels. While no information on in vitro and in vivo toxicity for all five substances was available

  17. 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.

  18. 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.

  19. UV-polymerized butyl methacrylate monoliths with embedded carboxylic single-walled carbon nanotubes for CEC applications.

    Science.gov (United States)

    Navarro-Pascual-Ahuir, María; Lucena, Rafael; Cárdenas, Soledad; Ramis-Ramos, Guillermo; Valcárcel, Miguel; Herrero-Martínez, José Manuel

    2014-10-01

    The preparation of polymeric monoliths with embedded carboxy-modified single-walled carbon nanotubes (c-SWNTs) and their use for capillary electrochromatography (CEC) is described. Carbon nanotube composites were obtained by preparing a polymerization mixture in the presence of increasing c-SWNT concentrations, followed by UV initiation. The novel stationary phases were studied by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Using short UV-polymerization times, the optimized porogenic solvent (a binary mixture of 1,4-butanediol and 2-propanol) gave rise to polymeric beds with homogenously dispersed embedded c-SWNTs. The CEC features of these monoliths were evaluated using polycyclic aromatic hydrocarbons (PAHs), non-steroidal anti-inflammatory drugs (NSAIDs) and chiral compounds. The monolith prepared in the presence of c-SWNTs showed enhanced resolution of the text mixtures, including a remarkable capability to separate enantiomers.

  20. Study of the solubility and stability of polystyrene wastes in a dissolution recycling process.

    Science.gov (United States)

    García, María Teresa; Gracia, Ignacio; Duque, Gema; Lucas, Antonio de; Rodríguez, Juan Francisco

    2009-06-01

    Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a "green process" the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at different temperatures has been investigated. The solvent can be easily recycled by distillation.

  1. 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.

  2. Production of 2-butanol from crude glycerol by a genetically-engineered Klebsiella pneumoniae strain.

    Science.gov (United States)

    Oh, Baek-Rock; Heo, Sun-Yeon; Lee, Sung-Mok; Hong, Won-Kyung; Park, Jang Min; Jung, You Ree; Kim, Dae-Hyuk; Sohn, Jung-Hoon; Seo, Jeong-Woo; Kim, Chul Ho

    2014-01-01

    Klebsiella pneumoniae was engineered to produce 2-butanol from crude glycerol as a sole carbon source by expressing acetolactate synthase (ilvIH), keto-acid reducto-isomerase (ilvC) and dihydroxy-acid dehydratase (ilvD) from K. pneumoniae, and α-ketoisovalerate decarboxylase (kivd) and alcohol dehydrogenase (adhA) from Lactococcus lactis. Engineered K. pneumonia, ∆ldhA/pBR-iBO (ilvIH–ilvC–ilvD–kivd–adhA), produced 2-butanol (160 mg l−1) from crude glycerol. To increase the yield of 2-butanol, we eliminated the 2,3-butanediol pathway from the recombinant strain by inactivating α-acetolactate decarboxylase (adc). This further engineering step improved the yield of 2-butanol from 160 to 320 mg l−1. This represents the first successful attempt to produce 2-butanol from crude glycerol.

  3. 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.

  4. 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.

  5. 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% .

  6. 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.

  7. 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%.

  8. The effect of polyether functional polydimethylsiloxane on surface and thermal properties of waterborne polyurethane

    Science.gov (United States)

    Zheng, Guikai; Lu, Ming; Rui, Xiaoping

    2017-03-01

    Waterborne polyurethanes (WPU) modified with polyether functional polydimethylsiloxane (PDMS) were synthesized by pre-polymerization method using isophorone diisocyanate (IPDI) and 1,4-butanediol (BDO) as hard segments and polybutylene adipate glycol (PBA) and polyether functional PDMS as soft segments. The effect of polyether functional PDMS on phase separation, thermal properties, surface properties including surface composition, morphology and wettability were investigated by FTIR, contact angle measurements, ARXPS, SEM-EDS, AFM, TG and DSC. The results showed that the compatibility between urethane hard segment and PDMS modified with polyether was good, and there was no distinct phase separation in both bulk and surface of WPU films. The degradation temperature and low temperature flexibility increased with increasing amounts of polyether functional PDMS. The enrichment of polyether functional PDMS with low surface energy on the surface imparted excellent hydrophobicity to WPU films.

  9. 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.

  10. 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.

  11. Engineering of carboligase activity reaction in Candida glabrata for acetoin production.

    Science.gov (United States)

    Li, Shubo; Xu, Nan; Liu, Liming; Chen, Jian

    2014-03-01

    Utilization of Candida glabrata overproducing pyruvate is a promising strategy for high-level acetoin production. Based on the known regulatory and metabolic information, acetaldehyde and thiamine were fed to identify the key nodes of carboligase activity reaction (CAR) pathway and provide a direction for engineering C. glabrata. Accordingly, alcohol dehydrogenase, acetaldehyde dehydrogenase, pyruvate decarboxylase, and butanediol dehydrogenase were selected to be manipulated for strengthening the CAR pathway. Following the rational metabolic engineering, the engineered strain exhibited increased acetoin biosynthesis (2.24 g/L). In addition, through in silico simulation and redox balance analysis, NADH was identified as the key factor restricting higher acetoin production. Correspondingly, after introduction of NADH oxidase, the final acetoin production was further increased to 7.33 g/L. By combining the rational metabolic engineering and cofactor engineering, the acetoin-producing C. glabrata was improved stepwise, opening a novel pathway for rational development of microorganisms for bioproduction.

  12. Epoxy-photopolymer composites: thick recording media for holographic data storage

    Science.gov (United States)

    Trentler, Timothy J.; Boyd, Joel E.; Colvin, Vicki L.

    2001-06-01

    Archival data-storage based on holographic methods requires high performance recording materials. Here, we describe an epoxy-photopolymer composite material which is sensitive to visible light and can be fabricated as thick films. These materials are prepared by combining photopolymerizable vinyl monomers with a liquid epoxy resin and an amine hardener. As the epoxy cures at room temperature, a solid matrix is formed which surrounds the unreacted photopolymer. These vinyl monomers are subsequently photopolymerized during hologram recording. Typically the material consists of a low index matrix, composed of diethylenetriamine and 1,4- butanediol diglycidyl ether, and a high index photopolymer mixture of N-vinylcarbazole and N-vinyl-2-pyrrolidinone. Because the polymers can be prepared in thick formats, narrow angular bandwidth holograms with high diffraction efficiency can be recorded. A dynamic range up to 13 has been measured in these materials.

  13. Synthesis and physicochemical study of ZSM-5 high-silica zeolite from natural raw materials

    Science.gov (United States)

    Aliev, A. M.; Mamedova, U. A.; Samedov, Kh. R.; Sarydzhanov, A. A.; Agaeva, R. Yu.

    2011-02-01

    ZSM-5 high-silica zeolite was obtained from metakaolinite, Dzhenranchel'sk volcanic ash, and silica gel at T = 150-220°C, pH 9-13, and τ = 48-240 h with the use of an organic structure-forming additive, butanediol-1,4, in an alkaline solution. Optimum conditions for the synthesis of ZSM-5 zeolite were found ( T = 200°C, pH 10, τ = 144 h). The catalytic properties of its H-form in vapor-phase esterification of acetic acid ( I) with ethanol ( II) were studied at 140-180°C and a I: II molar ratio from 1 to 2. Synthesized HZSM-5 showed high activity and selectivity in this reaction.

  14. SYNTHESIS AND AVERAGE SEQUENCE LENGTH DETERMINATION OF AROMATIC-ALIPHATIC COPOLYESTERS CONTAINING POLY(ALKYLENE OXALATE) UNITS

    Institute of Scientific and Technical Information of China (English)

    Yun-hui Zhao; Fen Wang; Xu-bo Yuan; Gen-hui Xu; Jing Sheng

    2008-01-01

    Two series of aromatic-aliphatic random copolyesters (PEBTOXS) with diverse diol ratios have been synthesizedby direct melting polycondensation. Two kinds of diols (glycol (EG) and 1,4-butanediol (BD)) are used in combination inorder to adjust crystallization and tensile properties, and three kinds of diacids (dimethyl terephthalate (DMT), diethyloxalate (DEOX), and sebacic acid (SA)) are involved. IH-NMR spectra quantify both composition and structure, and showthat the final contents in copolyesters appropriate to the feed ratio. Average sequence lengths of six polyester units arecalculated based on the analyses of 1H-NMR spectra and copolyester structure. The results reveal that the average sequencelengths of sebacate related units increase with the increasing content of sebacic acid in copolyesters, while those of oxalaterelated units show a slight rise. Decreases of average sequence length are found for all terephthalate units, which may bebecause of the restriction of rigid aromatic units in reactions.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Metabolic engineering of Saccharomyces cerevisiae microbial cell factories for succinic acid production

    DEFF Research Database (Denmark)

    Otero, José Manuel; Olsson, Lisbeth; Nielsen, Jens

    2007-01-01

    products is 18, 14, 54, and 9 C-mol/C-mol-glucose, respectively, with acids, encompassing fumaric, malic, and succinic acid. Succinic acid is a key building block molecule...... for further conversion to precursor molecules such as tetrahydrofuran, 1,4-butanediol, and butyrolactone. Succinic acid has the potential to become a commodity chemical, with world-wide annual demand exceeding $2 billion USD and over 160 million kg currently produced from petrochemical conversion of maleic...... anhydride. There are several biomass platforms, all prokaryotic, for succinic acid production; however, overproduction of succinic acid in S. cerevisiae offers distinct process advantages. For example, S. cerevisiae has been awarded GRAS status for use in human consumables, grows well at low p...

  2. 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.

  3. 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)

  4. Quorum Sensing Coordinates Cooperative Expression of Pyruvate Metabolism Genes To Maintain a Sustainable Environment for Population Stability

    Science.gov (United States)

    Hawver, Lisa A.; Giulietti, Jennifer M.; Baleja, James D.

    2016-01-01

    ABSTRACT Quorum sensing (QS) is a microbial cell-cell communication system that regulates gene expression in response to population density to coordinate collective behaviors. Yet, the role of QS in resolving the stresses caused by the accumulation of toxic metabolic by-products at high cell density is not well defined. In response to cell density, QS could be involved in reprogramming of the metabolic network to maintain population stability. Using unbiased metabolomics, we discovered that Vibrio cholerae mutants genetically locked in a low cell density (LCD) QS state are unable to alter the pyruvate flux to convert fermentable carbon sources into neutral acetoin and 2,3-butanediol molecules to offset organic acid production. As a consequence, LCD-locked QS mutants rapidly lose viability when grown with fermentable carbon sources. This key metabolic switch relies on the QS-regulated small RNAs Qrr1-4 but is independent of known QS regulators AphA and HapR. Qrr1-4 dictate pyruvate flux by translational repression of the enzyme AlsS, which carries out the first step in acetoin and 2,3-butanediol biosynthesis. Consistent with the idea that QS facilitates the expression of a common trait in the population, AlsS needs to be expressed cooperatively in a group of cells. Heterogeneous populations with high percentages of cells not expressing AlsS are unstable. All of the cells, regardless of their respective QS states, succumb to stresses caused by toxic by-product accumulation. Our results indicate that the ability of the bacteria to cooperatively control metabolic flux through QS is critical in maintaining a sustainable environment and overall population stability. PMID:27923919

  5. Three-dimensional nonwoven scaffolds from a novel biodegradable poly(ester amide) for tissue engineering applications.

    Science.gov (United States)

    Hemmrich, Karsten; Salber, Jochen; Meersch, Melanie; Wiesemann, Ute; Gries, Thomas; Pallua, Norbert; Klee, Doris

    2008-01-01

    Biodegradable polyesters are established biomaterials in medicine due to their chemical characteristics and options for material processing. A main problem, however, is the release of acid degradation products during biodegradation with severe local pH-drops and inflammatory reactions. Polyesteramides, in contrast, show a less prominent pH-drop during degradation. In this study, we developed a simple, reproducible synthesis of the poly(ester amide) (PEA) type C starting from epsilon-caprolactame, 1,4-butanediol, and adipic acid in a one-batch two-step reaction and conducted the manufacturing of PEA-derived 3D textile scaffolds applicable for tissue engineering purposes. The thermal and mechanical properties of PEA-type C were analysed and the structural conformity of different batches was confirmed by NMR spectroscopy and size exclusion chromatography. The polymer was formed into nonwovens by textile manufacturing. Cytotoxicity tests and X-ray photoelectron spectroscopy (XPS) were used to analyze the effect of scaffold extraction before cell seeding. The manufactured carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. The production of PEA type C successfully occurred via simultaneous ring-opening polymerization of epsilon-caprolactame and polycondensation with 1,4-butanediol and adipic acid at 250 degrees C under high-vacuum. Soxhlet extraction allowed optimal cleaning of nonwoven scaffolds. Extracted PEA-derived matrices were capable of allowing good adherence, proliferation, and differentiation of preadipocytes. These results are encouraging and guidance towards an optimally prepared nonwoven carrier applicable for clinical use.

  6. 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.

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    Ahuactzin-Pérez, Miriam [Doctorado en Biología Experimental, Universidad Autónoma Metropolitana-Iztapalapa (UAM-I) (Mexico); Facultad de Agrobiología, Universidad Autónoma de Tlaxcala, Ixtacuixtla, Tlaxcala (Mexico); Tlecuitl-Beristain, Saúl; García-Dávila, Jorge [Universidad Politécnica de Tlaxcala, San Pedro Xalcatzinco, Tepeyanco, Tlaxcala CP 90180 (Mexico); González-Pérez, Manuel [Universidad Popular Autónoma del Estado de Puebla, Puebla CP 72410 (Mexico); Gutiérrez-Ruíz, María Concepción [Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, D.F (Mexico); Sánchez, Carmen, E-mail: sanher6@hotmail.com [Laboratory of Biotechnology, Research Centre for Biological Sciences, Universidad Autónoma de Tlaxcala, Ixtacuixtla, Tlaxcala CP. 90062 (Mexico)

    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 (X{sub max}), biodegradation constant of DEHP (k), half-life (t{sub 1/2}) 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 1000 mg/L). The greatest μ and the largest X{sub max} occurred in media supplemented with 1000 mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000 mg/L) within 60 h of growth. The k and t{sub 1/2} were 0.024 h{sup −1} and 28 h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500 mg/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. - Highlights: • F. culmorum degraded 95% of DEHP (1000 mg/L) within 60 h. • Removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500 mg/L, respectively. • DEHP was fully metabolized by F. culmorum, with butanediol as the final product. • A DEHP biodegradation pathway was proposed using on quantum chemical modeling.

  8. 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.

  9. Enantioselective nano liquid chromatographic separation of racemic pharmaceuticals: a facile one-pot in situ preparation of lipase-based polymer monoliths in capillary format.

    Science.gov (United States)

    Ahmed, Marwa; Ghanem, Ashraf

    2014-11-01

    New affinity monolithic capillary columns of 150 µm internal diameter were prepared in situ fused glass capillary via either immobilization or encapsulation of Candida antarctica lipase B (CALB) on or within polymer monoliths, respectively. The immobilized lipase-based monoliths were prepared via copolymerization of 19.1% monomers (8.9% MMA and 10.2% GMA), 19.8% EDMA, and 61.1% porogens (54.2% formamide and 6.9% 1-propanol) w/w or 20% GMA, 20% EDMA, and 60% porogens (51.6% cyclohexanol and 8.4% 1-dodecanol) in the presence of AIBN (1%) as a radical initiator. This was followed by pumping a solution of lipase through the capillaries and rinsing with potassium phosphate buffer. On the other hand, the encapsulated lipase-based monoliths were prepared via copolymerization of 20% monomers (GMA), 20% EDMA, and 60% porogens (48% 1-propanol, 6% 1,4-butanediol) or 16.4% monomers (16% BuMA, 0.4% SPMA), 23.6% EDMA, and 60% porogens (36% 1-propanol, 18% 1,4-butanediol along with 6% lipase aqueous solution in potassium phosphate buffer. The prepared capillary columns were investigated for the enantioselective nano liquid chromatographic separation of a set of different classes of racemic pharmaceuticals, 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. Run-to-run repeatability was quite satisfactory. The encapsulated lipase-based capillary monolith showed better enantioselective separations of most of the investigated compounds. Baseline separation was achieved for alprenolol, atenolol, bromoglutithimide, carbuterol, chloropheneramine, cizolertine carbinol, 4-hydroxy-3-methoxymandelic acid, desmethylcizolertine, nomifensine, normetanephrine, and sulconazole under reversed phase chromatographic conditions. A speculation about the understanding of the chiral recognition mechanism of

  10. 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.

  11. Acetoin Synthesis Acquisition Favors Escherichia coli Growth at Low pH

    Science.gov (United States)

    Vivijs, Bram; Moons, Pieter; Aertsen, Abram

    2014-01-01

    Some members of the family Enterobacteriaceae ferment sugars via the mixed-acid fermentation pathway. This yields large amounts of acids, causing strong and sometimes even lethal acidification of the environment. Other family members employ the 2,3-butanediol fermentation pathway, which generates comparatively less acidic and more neutral end products, such as acetoin and 2,3-butanediol. In this work, we equipped Escherichia coli MG1655 with the budAB operon, encoding the acetoin pathway, from Serratia plymuthica RVH1 and investigated how this affected the ability of E. coli to cope with acid stress during growth. Acetoin fermentation prevented lethal medium acidification by E. coli in lysogeny broth (LB) supplemented with glucose. It also supported growth and higher stationary-phase cell densities in acidified LB broth with glucose (pH 4.10 to 4.50) and in tomato juice (pH 4.40 to 5.00) and reduced the minimal pH at which growth could be initiated. On the other hand, the acetoin-producing strain was outcompeted by the nonproducer in a mixed-culture experiment at low pH, suggesting a fitness cost associated with acetoin production. Finally, we showed that acetoin production profoundly changes the appearance of E. coli on several diagnostic culture media. Natural E. coli strains that have laterally acquired budAB genes may therefore have escaped detection thus far. This study demonstrates the potential importance of acetoin fermentation in the ecology of E. coli in the food chain and contributes to a better understanding of the microbiological stability and safety of acidic foods. PMID:25063653

  12. 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

  13. 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.

  14. Effects of eliminating pyruvate node pathways and of coexpression of heterogeneous carboxylation enzymes on succinate production by Enterobacter aerogenes.

    Science.gov (United States)

    Tajima, Yoshinori; Yamamoto, Yoko; Fukui, Keita; Nishio, Yousuke; Hashiguchi, Kenichi; Usuda, Yoshihiro; Sode, Koji

    2015-02-01

    Lowering the pH in bacterium-based succinate fermentation is considered a feasible approach to reduce total production costs. Newly isolated Enterobacter aerogenes strain AJ110637, a rapid carbon source assimilator under weakly acidic (pH 5.0) conditions, was selected as a platform for succinate production. Our previous work showed that the ΔadhE/PCK strain, developed from AJ110637 with inactivated ethanol dehydrogenase and introduced Actinobacillus succinogenes phosphoenolpyruvate carboxykinase (PCK), generated succinate as a major product of anaerobic mixed-acid fermentation from glucose under weakly acidic conditions (pH <6.2). To further improve the production of succinate by the ΔadhE/PCK strain, metabolically engineered strains were designed based on the elimination of pathways that produced undesirable products and the introduction of two carboxylation pathways from phosphoenolpyruvate and pyruvate to oxaloacetate. The highest production of succinate was observed with strain ES04/PCK+PYC, which had inactivated ethanol, lactate, acetate, and 2,3-butanediol pathways and coexpressed PCK and Corynebacterium glutamicum pyruvate carboxylase (PYC). This strain produced succinate from glucose with over 70% yield (gram per gram) without any measurable formation of ethanol, lactate, or 2,3-butanediol under weakly acidic conditions. The impact of lowering the pH from 7.0 to 5.5 on succinate production in this strain was evaluated under pH-controlled batch culture conditions and showed that the lower pH decreased the succinate titer but increased its yield. These findings can be applied to identify additional engineering targets to increase succinate production.

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

    Science.gov (United States)

    Johnston-Monje, David; Raizada, Manish N

    2011-01-01

    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 isolate

  16. 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

  17. Formate hydrogen lyase mediates stationary-phase deacidification and increases survival during sugar fermentation in acetoin-producing enterobacteria

    Directory of Open Access Journals (Sweden)

    Bram eVivijs

    2015-02-01

    Full Text Available Two fermentation types exist in the Enterobacteriaceae family. Mixed-acid fermenters produce substantial amounts of lactate, formate, acetate and succinate, resulting in lethal medium acidification. On the other hand, 2,3-butanediol fermenters switch to the production of the neutral compounds acetoin and 2,3-butanediol and even deacidify the environment after an initial acidification phase, thereby avoiding cell death. We equipped three mixed-acid fermenters (Salmonella Typhimurium, S. Enteritidis and Shigella flexneri with the acetoin pathway from Serratia plymuthica to investigate the mechanisms of deacidification. Acetoin production caused attenuated acidification during exponential growth in all three bacteria, but stationary-phase deacidification was only observed in Escherichia coli and Salmonella, suggesting that it was not due to the consumption of protons accompanying acetoin production. To identify the mechanism, 34 transposon mutants of acetoin-producing E. coli that no longer deacidified the culture medium were isolated. The mutations mapped to 16 genes, all involved in formate metabolism. Formate is an end product of mixed-acid fermentation that can be converted to H2 and CO2 by the formate hydrogen lyase (FHL complex, a reaction that consumes protons and thus can explain medium deacidification. When hycE, encoding the large subunit of hydrogenase 3 that is part of the FHL complex, was deleted in acetoin-producing E. coli, deacidification capacity was lost. Metabolite analysis in E. coli showed that introduction of the acetoin pathway reduced lactate and acetate production, but increased glucose consumption and formate and ethanol production. Analysis of a hycE mutant in S. plymuthica confirmed that medium deacidification in this organism is also mediated by FHL. These findings improve our understanding of the physiology and function of fermentation pathways in Enterobacteriaceae.

  18. 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

    2015-06-05

    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 mmol/kg. Ethanol was eliminated most rapidly, at 7.9 mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10 mmol/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 mmol/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 mmol/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.

  19. 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.

  20. 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

  1. Genome Sequence of the Plant Growth Promoting Endophytic Bacterium Enterobacter sp. 638

    Energy Technology Data Exchange (ETDEWEB)

    Taghavi, S.; van der Lelie, D.; Hoffman, A.; Zhang, Y.-B.; Walla, M. D.; Vangronsveld, J.; Newman, L.; Monchy, S.

    2010-05-13

    Enterobacter sp. 638 is an endophytic plant growth promoting gamma-proteobacterium that was isolated from the stem of poplar (Populus trichocarpa x deltoides cv. H11-11), a potentially important biofuel feed stock plant. The Enterobacter sp. 638 genome sequence reveals the presence of a 4,518,712 bp chromosome and a 157,749 bp plasmid (pENT638-1). Genome annotation and comparative genomics allowed the identification of an extended set of genes specific to the plant niche adaptation of this bacterium. This includes genes that code for putative proteins involved in survival in the rhizosphere (to cope with oxidative stress or uptake of nutrients released by plant roots), root adhesion (pili, adhesion, hemagglutinin, cellulose biosynthesis), colonization/establishment inside the plant (chemiotaxis, flagella, cellobiose phosphorylase), plant protection against fungal and bacterial infections (siderophore production and synthesis of the antimicrobial compounds 4-hydroxybenzoate and 2-phenylethanol), and improved poplar growth and development through the production of the phytohormones indole acetic acid, acetoin, and 2,3-butanediol. Metabolite analysis confirmed by quantitative RT-PCR showed that, the production of acetoin and 2,3-butanediol is induced by the presence of sucrose in the growth medium. Interestingly, both the genetic determinants required for sucrose metabolism and the synthesis of acetoin and 2,3-butanediol are clustered on a genomic island. These findings point to a close interaction between Enterobacter sp. 638 and its poplar host, where the availability of sucrose, a major plant sugar, affects the synthesis of plant growth promoting phytohormones by the endophytic bacterium. The availability of the genome sequence, combined with metabolome and transcriptome analysis, will provide a better understanding of the synergistic interactions between poplar and its growth promoting endophyte Enterobacter sp. 638. This information can be further exploited to

  2. 水性聚氨酯浆料的合成与性能%Synthesis and performance of water-soluble polyurethane sizing agents

    Institute of Scientific and Technical Information of China (English)

    吕福菊; 祝志峰

    2011-01-01

    为探索水性聚氨酯分子结构与件能的关系,以甲苯二异氰酸酯、聚丙二元醇、二羟甲基丙酸和l,4-丁二醇为原料,合成了一系列水性聚氨酯,并采用1 H-NMR(氢核磁共振)对其结构进行了表征.通过改变二羟甲基丙酸和聚丙二元醇的量,研究了水性聚氨酯分子结构对其水溶性、黏附性能和浆膜性能的影响.结果表明:随着二羟甲基丙酸量的增加,水性聚氨酯的水溶性提高.降低聚丙二元醇的量,有利于提高水性聚氨酯的黏附性能和浆膜强度,但会损害浆膜的耐磨性能.综合考虑各项性能指标,当上述4种原料之间物质的量比为1.05∶0.3∶0.3∶0.4时,水性聚氨酯浆料的性能最好.%In order to reveal the relationship between sizing performance and molecular structure of water-soluble polyurethane (WPU) used as warp sizing agents, a series of water-soluble polyurethane were synthesized using toluene diisocyanate, polypropylene glycol, dimethylol propionic acid and 1,4-butanediol as monomers. The structure was characterized by H-NMR. Through varying the contents of dimethylol propionic acid and polypropylene glycol, the effects of the structure on the solubility, adhesion-to-fiber, and film behaviors of the polyurethane were investigated. The results demonstrated that the solubility of the polyurethane was enhanced with the increase of the content of dimethylol propionic acid. The adhesion and film strength increased with the decrease of the content of polypropylene glycol, but the abrasion resistance of the sizing film decreased. Taking into consideration the comprehensive factors, the polyurethane with optimal properties could be prepared by adopting a monomer formulation in which the proportion of toluene diisocyanate, polypropylene glycol, dimethylol propionic acid and 1,4-butanediol was 1. 05: 0. 3: 0. 3: 0. 4.

  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. 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。

  5. Reactivity of polyfunctional alcohols towards atmospheric radicals in the aqueous solution

    Science.gov (United States)

    Hoffmann, D.; Herrmann, H.

    2009-04-01

    Alcohols such as ethylene glycol, propylene glycol and glycerol are widely used compounds in numerous applications. The oxidation of these compounds can influence the tropospheric oxidation budget as well as contribute significantly to the formation of low volatile organic particle constituents, such as mono- and dicarboxylic acids. Model simulations applying the multiphase chemistry mechanism CAPRAM 3.0i (Chemical Aqueous Phase Radical Mechanism) show that the aqueous phase oxidation of ethylene glycol contribute significantly to the formation of the known particle constituent oxalic acid under remote (up to 1.7%) and urban (up to 9.5%) conditions. Due to their high solubility oxidation processes of polyalcohols will take place mainly in the aqueous solution. Oxidation reactions of alcohols are triggered by reactions with atmospheric radicals such as OH, NO3 and SO4-. However, for the detailed implementation of the tropospheric degradation of alcohols in atmospheric chemistry mechanisms many kinetic data, in particular as a function of the temperature, are still needed. Therefore, the reactivity of 1,2-ethanediol (ethylene glycol), 1,2-propanediol (propylene glycol), 1,3-propanediol, 1,2,3-propanetriol (glycerol), 1,2-butanediol, 1,4-butanediol and 1,5-pentanediol was systematically investigated towards OH, NO3 and SO4- radicals in the aqueous solution. All kinetic measurements were done as a function of the temperature. During these experiments the temperature of the measurement solution was varied between 278 ≤ T [K] ≤ 318. Experiments were carried out using laser flash photolysis technique at a wavelength of 248 nm. Rate constants were measured directly or using competition kinetics in case of OH. The kinetic data and activation parameters obtained will be summarized and discussed with available literature data. Furthermore, the data obtained will be discussed in terms of reactivity correlations and atmospheric relevance. A more detailed implementation of

  6. 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

  7. 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%).

  8. 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.

  9. 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

  10. 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.

  11. SYNTHESIS AND PHASE BEHAVIOR OF POLYURETHANES END-CAPPED WITH FLUORINATED PHOSPHATIDYLCHOLINE HEAD GROUPS

    Institute of Scientific and Technical Information of China (English)

    Dong-sheng Tan; Xiao-qing Zhang; Jian-chuan Wang; Jie-hua Li; Hong Tan; Qiang Fu

    2011-01-01

    A series of fluorinated phosphatidylcholine polyurethane macromolecular additives were synthesized by solution polymerization using methylenebis(phylene isocyanates) (MDI) and 1,4-butanediol (BDO) as hard segments,a new phoshporycholine,2-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-10-(2-hydroxyethoxy)decyloxy) ethyl phosphorycholine (HDFOPC) as end-capper,and four polydiols,poly(tetramethylene glycol)s (PTMG),polydimethylsiloxane (PDMS),poly(1,6-hexyl-1,5-pentylcarbonate) (PHPC) and poly(propylene glycol) (PPG) as soft segments,respectively.The chemical structures of the synthesized polyurethanes were characterized by 1H-NMR and FTIR.DSC and DMA were employed to study the phase behavior of these novel polyurethanes due to their great influences on the surface properties,and hence their interactions with bio-systems.The results showed that phase separation of the fluorinated phosphatidylcholine end-capped polyurethanes was increased in comparison with that of normal polyurethanes.The effect of fluorinated phosphatidylcholine end-capped groups on the phase behavior was further demonstrated by analyzing the degree of hydrogen-bonding between hard and soft segments.

  12. Pretreatment based on two-step steam explosion combined with an intermediate separation of fiber cells--optimization of fermentation of corn straw hydrolysates.

    Science.gov (United States)

    Zhang, Yuzhen; Fu, Xiaoguo; Chen, Hongzhang

    2012-10-01

    Pretreatment is necessary for lignocellulose to achieve a highly efficient enzymatic hydrolysis and fermentation. However, coincident with pretreatment, compounds inhibiting microorganism growth are formed. Some tissues or cells, such as thin-walled cells that easily hydrolyze, will be excessively degraded because of the structural heterogeneity of lignocellulose, and some inhibitors will be generated under the same pretreatment conditions. Results showed, compared with one-step steam explosion (1.2 MPa/8 min), two-step steam explosion with an intermediate separation of fiber cells (ISFC) (1.1 Mpa/4 min-ISFC-1.2 MPa/4 min) can increase enzymatic hydrolyzation by 12.82%, reduce inhibitor conversion by 33%, and increase fermentation product (2,3-butanediol) conversion by 209%. Thus, the two-step steam explosion with ISFC process is proposed to optimize the hydrolysis process of lignocellulose by modifying the raw material from the origin. This novel process reduces the inhibitor content, promotes the biotransformation of lignocellulose, and simplifies the process of excluding the detoxification unit operation.

  13. Polyesteramide-derived nonwovens as innovative degradable matrices support preadipocyte adhesion, proliferation, and differentiation.

    Science.gov (United States)

    Hemmrich, K; Meersch, M; Wiesemann, U; Salber, J; Klee, D; Gries, Th; Pallua, N

    2006-12-01

    Extended soft tissue defects resulting from injuries or tumor resections are still an unresolved problem in plastic and reconstructive surgery because adequate reconstruction is difficult. Immature adipogenic precursor cells, called preadipocytes, which are located between mature adipocytes in adipose tissue, represent a powerful tool for soft tissue engineering because of their ability to proliferate and differentiate into adipose tissue after transplantation. In previous studies, we compared preadipocyte-loaded hyaluronan or collagen biomaterials and their applicability for adipose tissue engineering. Our findings demonstrated successful de novo formation of adipose tissue in vivo but pore size and stiffness were limiting factors not allowing for sufficient cell distribution in the construct. This study presents a nonwoven made of novel bioabsorbable co-poly(ester amide) based on e-caprolactam, adipic acid, and 1,4-butanediol in an innovative 3-dimensional architecture. The material was formed into nonwovens by textile manufacturing using an aerodynamic web formation process and a needle felting technique. Carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. In addition, methods of preparing scaffolds for optimal cell interaction were evaluated. Our findings show that polyesteramide-derived nonwovens allow good adherence, proliferation, and differentiation of preadipocytes. These results are promising guidance toward an optimally designed scaffold for in vivo use.

  14. Synthesis of RNAs with up to 100 Nucleotides Containing Site-Specific 2-methylseleno Labels for use in X-ray Crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Hobartner,C.; Rieder, R.; Kreutz, C.; Puffer, B.; Lang, K.; Polonskaia, A.; Serganov, A.; Micura, R.

    2005-01-01

    The derivatization of nucleic acids with selenium is a new and highly promising approach to facilitate their three-dimensional structure determination by X-ray crystallography. Here, we report a comprehensive study on the chemical and enzymatic syntheses of RNAs containing 2'-methylseleno (2'-Se-methyl) nucleoside labels. Our approach includes the first synthesis of an appropriate purine nucleoside phosphoramidite building block. Most importantly, a substantially changed RNA solid-phase synthesis cycle, comprising treatment with threo-1, 4-dimercapto-2, 3-butanediol (DTT) after the oxidation step, is required for a reliable strand elongation. This novel operation allows for the chemical syntheses of multiple Se-labeled RNAs in sizes that can typically be achieved only for nonmodified RNAs. In combination with enzymatic ligation, biologically important RNA targets become accessible for crystallography. Exemplarily, this has been demonstrated for the Diels-Alder ribozyme and the add adenine riboswitch sequences. We point out that the approach documented here has been the chemical basis for the very recent structure determination of the Diels-Alder ribozyme which represents the first novel RNA fold that has been solved via its Se-derivatives.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Bioactive Compound Evaluation of Ethanol Extract from Geodorum densiflorum (Lam. Schltr. by GC-MS analysis

    Directory of Open Access Journals (Sweden)

    Keerthiga Manohar

    2015-06-01

    Full Text Available The phytochemical constituents are responsible for medicinal value of the plant species. The present investigation was carried out to analyze the bioactive components from the whole plant of Geodorum densiflorum (Lam. Schltr using GC-MS technique. The chemical compositions of the ethanolic extract of G. densiflorum were investigated using Perkin - Elmer Gas Chromatography – Mass Spectrometry and about twenty one bioactive phytochemical compounds were identified. The prevailing compounds where Hexadecanoic acid, Ethyl ester (38.884 %, Ionone (7.125 %, 3-Deoxy-d-mannoic lactone (7.4441 %, 2,3-Butanediol (4.725 % and 2-Piperidinone, N-[4-bromo-n-butyl]- (4.004 %, (E-9-Octadeconoic acid ethyl ester (3.891 %, 1H-Pyrrole-2-Carbonitrile (3.778 %, Pyridinium, 1-amino-, chloride (3.305 %, 4H- Pyran-4-one, 3,5-dihydroxy-2-methyl- (3.274 and having various biological activities. This was the first report on the identification of bioactive compounds from ethanol extract of G. densiflorum.

  1. The Development and Application of a Method to Quantify the Quality of Cryoprotectant Conditions Using Standard Area Detector X-Ray Images

    Science.gov (United States)

    McFerrin, Michael; Snell, Edward; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    An X-ray based method for determining cryoprotectant concentrations necessary to protect solutions from crystalline ice formation was developed. X-ray images from a CCD area detector were integrated as powder patterns and quantified by determining the standard deviation of the slope of the normalized intensity curve in the resolution range where ice rings are known to occur. The method was tested determining the concentrations of glycerol, PEG400, ethylene glycol and 1,2-propanediol necessary to form an amorphous glass at 1OOK with each of the 98 crystallization solutions of Crystal Screens I and II (Hampton Research, Laguna Hills, California, USA). For conditions that required glycerol concentrations of 35% or above cryoprotectant conditions using 2,3-butanediol were determined. The method proved to be remarkably accurate. The results build on the work of [Garman and Mitchell] and extend the number, of suitable starting conditions to alternative cryoprotectants. In particular, 1,2-propanediol has emerged as a particularly good additive for glass formation upon flash cooling.

  2. 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.

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

    Science.gov (United States)

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

    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 1H-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 × 10-8 M, where s/n = 3) were found at the G-g-PLA-Pd modified glassy carbon electrode (GCE).

  4. 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.

  5. 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.

  6. [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.

  7. 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.

  8. 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.

  9. 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.

  10. 聚氨酯相变材料的非等温结晶动力学研究%Investigation on the Non-isothermal Crystallization Kinetics of Polyurethane Phase Change Materials

    Institute of Scientific and Technical Information of China (English)

    王宇; 田春蓉; 芦艾; 王建华; 黄奕刚; 黄玉西

    2012-01-01

    Polyurethane phase change materials(PUPCMs) were synthesized by Polyethylene glycol)(PEG; Mn=6 000), 4,4'-methylenebis(phenyl isocyanate)(MDI) and 1,4-butanediol(BDO), which contained 86% soft segments. Non-isothermal crystallization kinetics of PUPCMs were studied by means of DSC, Mo ZhiShen equation and Ozawa equation. The results show that there is great difference in the datas from Ozawa equation and MoZhiShen equation, and Ozawa equation is more suitable for the actual crystallization process.%以聚乙二醇-6000(PEG-6000)、4,4′-二苯基甲烷二异氰酸酯(MDI)、1,4-丁二醇(BDO)为原料制备了软段含量为86%的聚氨脂相变材料(PUPCMs).采用DSC测试手段,并且以Ozawa方程和莫志深方程为主要模型,分析研究了聚氨酯相变材料非等温结晶动力学.结果表明:Ozawa方程与莫志深方程的结果差别较大,而Ozawa方程更加符合实际的结晶过程.

  11. 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.

  12. In vitro evaluation of elastic multiblock co-polymers as a scaffold material for reconstruction of blood vessels.

    Science.gov (United States)

    Tzoneva, Rumiana; Weckwerth, Claudia; Seifert, Barbara; Behl, Marc; Heuchel, Matthias; Tsoneva, Iana; Lendlein, Andreas

    2011-01-01

    There is a need to create cell- and histocompatible implant materials, which might temporarily replace the mechanical function of a native tissue for regenerative therapies. To match the elastic behavior of the native tissue two different multiblock co-polymers were investigated: PDC, consisting of poly(p-dioxanone) (PPDO)/poly(ε-caprolactone) (PCL), and PDD, based on PPDO/poly((adipinate-alt-1,4-butanediol)-co-(adipinate-alt-ethylene glycol)-co-adipinate-alt-diethylene glycol) (Diorez). PDC is capable of a shapememory effect. Both multiblock co-polymers show an improved elasticity compared to materials applied in established vascular prosthesis. PDD is softer than PDC at 20°C, while PDC maintains its elasticity at 37°C. Thermodynamic characteristics indicate a more polar surface of PDD. Low cell adhesion was found on surfaces with low molar free energy of hysteresis (ΔG) derived from contact angle measurements in wetting and dewetting mode and high cell adhesion on high-ΔG surfaces. An increasing content of PCL in PDC improved cell adhesion and spreading of human umbilical vein endothelial cells. The prothrombotic potential of PDD is higher than PDC. Finally, it is concluded that PDC is a promising material for vascular tissue engineering because of its improved elastic properties, as well as balanced prothrombotic and anti-thrombotic properties with endothelial cells.

  13. 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.

  14. Synthesis and characterization of new hydroxycarboxylate compounds obtained in the redox reaction between Fe(NO{sub 3}){sub 3} and diol

    Energy Technology Data Exchange (ETDEWEB)

    Stefanescu, O., E-mail: oana.stefanescu@chim.upt.ro [Politehnica University of Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, P-ta Victoriei No. 2, Timisoara, RO-300006 (Romania); Vlase, T.; Vlase, G.; Doca, N. [West University of Timisoara, Research Center for Thermal Analysis in Environmental Problems, Str. Pestalozzi No. 16, Timisoara, RO-300115 (Romania); Stefanescu, M. [Politehnica University of Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, P-ta Victoriei No. 2, Timisoara, RO-300006 (Romania)

    2011-05-20

    Highlights: {yields} New hydroxycarboxylate compounds obtained in the redox reaction Fe(NO{sub 3}){sub 3}-diols. {yields} Octahedral stereochemistry with [Fe(III)O{sub 6}] chromophore for the synthesized complexes. {yields} Fe(III) glyoxylate and succinate as precursors of iron oxide {gamma}-Fe{sub 2}O{sub 3} nanoparticles. - Abstract: The paper presents experimental studies and structural investigations of two new Fe(III) hydroxycarboxylate coordination compounds. The homopolynuclear complex combinations of Fe(III) glyoxylate and succinate type were obtained in the redox reaction between Fe(NO{sub 3}){sub 3} and diols (1,2-ethanediol and 1,4-butanediol). The synthesized coordination compounds and the products formed during their thermal conversion were characterized by thermal analysis (in air and nitrogen), FT-IR and UV-VIS spectrometry, Moessbauer spectrometry, electron microscopy and XRD. By thermal decomposition of the complex combinations, at 300 {sup o}C, the well crystallized pure phase {gamma}-Fe{sub 2}O{sub 3} as nanoparticles were formed.

  15. 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.

  16. N7-guanine adducts of the epoxy metabolites of 1,3-butadiene in mice lung.

    Science.gov (United States)

    Koivisto, P; Peltonen, K

    2001-06-01

    Epoxy metabolites of 1,3-butadiene are electrophilic and can bind to nucleophilic sites in DNA forming DNA adducts. In this study, guanine N7 adducts of epoxy butene and guanine N7 adducts of epoxy butanediol were measured in lung tissues of mice inhalation exposed to various concentrations of 1,3-butadiene. 32P-postlabeling of DNA adducts were used to demonstrate that the DNA adducts derived from epoxybutene and epoxybutanediol were formed in a dose dependent manner. More than 98% of all adducts detected were formed from epoxybutanediol. Enantiomeric distribution of the adducts formed in vivo differs from that of in vitro experiments demonstrated before. In the case of epoxybutene most of the adducts were formed to the terminal carbon of the S-epoxybutene enantiomer. Most of the adducts derived from epoxybutanediol were formed from the 2S-3R enantiomer. The data demonstrates that enzymatic processes involved with activation and/or detoxification of the metabolites are enantiospecific and/or DNA repair machinery repairs the damage with stereochemical considerations. These are the crucial factors if interspecies differences in tumor sensitiveness is concerned.

  17. 1,2,3,4-Diepoxybutane-induced DNA-protein cross-linking in human fibrosarcoma (HT1080) cells.

    Science.gov (United States)

    Gherezghiher, Teshome B; Ming, Xun; Villalta, Peter W; Campbell, Colin; Tretyakova, Natalia Y

    2013-05-03

    1,2,3,4-Diepoxybutane (DEB) is the key carcinogenic metabolite of 1,3-butadiene (BD), an important industrial and environmental chemical present in urban air and in cigarette smoke. DEB is a genotoxic bis-electrophile capable of cross-linking cellular biomolecules to form DNA-DNA and DNA-protein cross-links (DPCs). In the present work, mass spectrometry-based proteomics was employed to characterize DEB-mediated DNA-protein cross-linking in human fibrosarcoma (HT1080) cells. Over 150 proteins including histones, high mobility group proteins, transcription factors, splicing factors, and tubulins were found among those covalently cross-linked to chromosomal DNA in the presence of DEB. A large portion of the cross-linked proteins are known factors involved in DNA binding, transcriptional regulation, cell signaling, DNA repair, and DNA damage response. HPLC-ESI(+)-MS/MS analysis of total proteolytic digests revealed the presence of 1-(S-cysteinyl)-4-(guan-7-yl)-2,3-butanediol conjugates, confirming that DEB forms DPCs between cysteine thiols within proteins and the N-7 guanine positions within DNA. However, relatively high concentrations of DEB were required to achieve significant DPC formation, indicating that it is a poor cross-linking agent as compared to antitumor nitrogen mustards and platinum compounds.

  18. A novel approach to improve poly-γ-glutamic acid production by NADPH Regeneration in Bacillus licheniformis WX-02

    Science.gov (United States)

    Cai, Dongbo; He, Penghui; Lu, Xingcheng; Zhu, Chengjun; Zhu, Jiang; Zhan, Yangyang; Wang, Qin; Wen, Zhiyou; Chen, Shouwen

    2017-01-01

    Poly-γ-glutamic acid (γ-PGA) is an important biochemical product with a variety of applications. This work reports a novel approach to improve γ-PGA through over expression of key enzymes in cofactor NADPH generating process for NADPH pool. Six genes encoding the key enzymes in NADPH generation were over-expressed in the γ-PGA producing strain B. licheniformis WX-02. Among various recombinants, the strain over-expressing zwf gene (coding for glucose-6-phosphate dehydrogenase), WX-zwf, produced the highest γ-PGA concentration (9.13 g/L), 35% improvement compared to the control strain WX-pHY300. However, the growth rates and glucose uptake rates of the mutant WX-zwf were decreased. The transcriptional levels of the genes pgsB and pgsC responsible for γ-PGA biosynthesis were increased by 8.21- and 5.26-fold, respectively. The Zwf activity of the zwf over expression strain increased by 9.28-fold, which led to the improvement of the NADPH generation, and decrease of accumulation of by-products acetoin and 2,3-butanediol. Collectively, these results demonstrated that NADPH generation via over-expression of Zwf is as an effective strategy to improve the γ-PGA production in B. licheniformis. PMID:28230096

  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.

  20. Changes in the bacterial community and composition of fermentation products during ensiling of wilted Italian ryegrass and wilted guinea grass silages.

    Science.gov (United States)

    Li, Yanbing; Nishino, Naoki

    2013-08-01

    To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3-Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre-ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre-ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre-ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.

  1. 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.

  2. New agar microspheres for the separation and purification of natural products.

    Science.gov (United States)

    Ge, Chunling; Hu, Yu; Zhang, Fan; Lv, Yongqin; Tan, Tianwei

    2014-11-01

    A new type of agar chromatography media has been prepared with a yield over 80% using a water-in-oil emulsion technique. These microspheres have regular spherical shapes and particle diameters in the range 40-165 μm (average ∼90 μm). Cross-linking of the resulting agar microspheres with epichlorohydrin and 1,4-butanediol diglycidyl ether enhanced their mechanical and thermal stability. The alkaline conditions used during the cross-linking reaction also decreased the content of ionized sulfate groups of the polysaccharide, thus reducing the nonspecific adsorption of positively charged molecules. The cross-linked agar microspheres were functionalized with (i) branched poly(ethyleneimine) to obtain a stationary phase useful for the separation of proteins in an anion-exchange mode and (ii) with poly-β-cyclodextrin enabling direct isolation and purification of puerarin from a crude extract of Radix puerariae. Using a 23.5 mL column loaded with 20 mg extract (0.85 mg/mL gel), puerarin with a purity of 96% was recovered with a yield of 86%.

  3. Direct electrospray ionization mass spectrometry quantitative analysis of sebacic and terephthalic acids in biodegradable polymers.

    Science.gov (United States)

    Rizzarelli, Paola; Zampino, Daniela; Ferreri, Loredana; Impallomeni, Giuseppe

    2011-02-01

    A direct, rapid, and easy electrospray ionization mass spectrometry (ESI-MS) method to determine concentrations of sebacic acid (SA) and terephthalic acid (TA) residues in biodegradable copolymers was developed. Copolyester samples were synthesized from 1,4-butanediol and sebacic and terephthalic acids by melt polymerization. Extraction of monomers was performed in methanol. Their concentrations were determined by direct infusion ESI-MS, without chromatographic separation, using 1,12-dodecanedioic acid (DDA) as an internal standard. Calibration curves were obtained by plotting the ratio of the areas of the peaks relative to monomers and DDA standard as a function of their concentration ratio. We validated the method by determining the concentration of TA residue using both the ESI-MS protocol and high-performance liquid chromatography (HPLC) analysis with UV detection. The linearity range and the detection limit of this assay were 0.1-5.0 and 0.01 ppm for SA and 0.1-6.0 and 0.03 ppm for TA. This assay represents a useful alternative to conventional methods currently employed for acid quantification, resulting advantageous for its speed and high sensitivity.

  4. 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.

  5. 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.

  6. 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.

  7. Simultaneous determination of γ-Hydroxybutyrate (GHB) and its analogues (GBL, 1.4-BD, GVL) in whole blood and urine by liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Johansen, Sys Stybe; Windberg, Charlotte Norup

    2011-01-01

    A simple liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for simultaneous identification and quantification of γ-hydroxybutyrate (GHB), γ-butyrolactone (GBL), 1.4-butanediol (1.4-BD), and γ-valerolactone (GVL) in whole blood from forensic cases. The sample preparation of whole blood involved protein precipitation by acidic methanol. Urine samples were diluted and evaluated in relation to a control at the cutoff concentration. Hexadeutero GHB (GHB-d(6)) was used as the internal standard. Separation was achieved by reversed-phase chromatography, and detection was by MS-MS in MRM mode. The linear range for all compounds was from 1.0 to 100 mg/kg in whole blood with a limit of quantification of about 1 mg/kg. The method was validated with regards to selectivity, recovery, accuracy and precision, and stability. The method is currently applied to investigations on suspected drug-facilitated sexual assaults, driving under the influence of drugs, and general intoxication with these substances.

  8. Lack of effects of GHB precursors GBL and 1,4-BD following i.c.v. administration in rats.

    Science.gov (United States)

    Carter, Lawrence P; Koek, Wouter; France, Charles P

    2006-11-01

    Gamma-hydroxybutyrate (GHB) is used therapeutically and recreationally worldwide. Since the scheduling of GHB by the USA and the United Nations in 2000-2001, the recreational use of GHB precursors has reportedly increased. The aim of this study was to examine if potency differences of GHB and GHB-like compounds are due to their blood-brain barrier permeability. The effects of peripheral and central administration of GHB, GHB precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), and the gamma-aminobutyric acid (GABA)(B) receptor agonist baclofen on schedule-controlled responding were examined in rats. GHB and baclofen were 276- and 253-fold more potent, respectively, after intracerebroventricular (i.c.v.) administration than after intraperitoneal (i.p.) administration, whereas GBL and 1,4-BD, up to a dose of 1780 microg were without effect after i.c.v. administration. These data suggest that GBL and 1,4-BD are not metabolically converted to GHB in the brain, that enhanced brain penetration cannot account for potency differences between compounds, and that baclofen, like GHB, can readily cross the blood-brain barrier.

  9. Regenerable Subnanometer Pd Clusters on Zirconia for Highly Selective Hydrogenation of Biomass-Derived Succinic Acid in Water

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2016-07-01

    Full Text Available The size of metal particles is an important factor to determine the performance of the supported metal catalysts. In this work, we report subnanometer Pd clusters supported on zirconia by the microwave-assisted hydrothermal method. The presence of subnanometer Pd clusters on the zirconia surface was confirmed by two-dimensional Gaussian-function fits of the aberration-corrected high-angle annual dark-field images. These subnanometer Pd catalysts exhibit high catalytic performance for the hydrogenation of biomass-derived succinic acid to γ-butyrolactone in water and avoid the formation of overhydrogenated products, such as 1,4-butanediol and tetrahydrofuran. The catalyst with an ultra-low Pd loading of 0.2 wt. % demonstrated high selectivity (95% for γ-butyrolactone using water as a solvent at 473 K and 10 MPa. Moreover, it can be reused at least six times without the loss of catalytic activity, illustrating high performance of the small Pd clusters.

  10. Carbon monoxide fermentation to ethanol by Clostridium autoethanogenum in a bioreactor with no accumulation of acetic acid.

    Science.gov (United States)

    Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

    2015-06-01

    Fermentation of CO or syngas offers an attractive route to produce bioethanol. However, during the bioconversion, one of the challenges to overcome is to reduce the production of acetic acid in order to minimize recovery costs. Different experiments were done with Clostridium autoethanogenum. With the addition of 0.75 μM tungsten, ethanol production from carbon monoxide increased by about 128% compared to the control, without such addition, in batch mode. In bioreactors with continuous carbon monoxide supply, the maximum biomass concentration reached at pH 6.0 was 109% higher than the maximum achieved at pH 4.75 but, interestingly, at pH 4.75, no acetic acid was produced and the ethanol titer reached a maximum of 867 mg/L with minor amounts of 2,3-butanediol (46 mg/L). At the higher pH studied (pH 6.0) in the continuous gas-fed bioreactor, almost equal amounts of ethanol and acetic acid were formed, reaching 907.72 mg/L and 910.69 mg/L respectively.

  11. GC/MS profiling of gamma-hydroxybutyrate and precursors in various animal tissues using automatic solid-phase extraction. Preliminary investigations of its potential interest in postmortem interval determination.

    Science.gov (United States)

    Richard, Damien; Ling, Bing; Authier, Nicolas; Faict, Thierry W; Eschalier, Alain; Coudoré, François

    2005-03-01

    To quantify gamma-hydroxybutyrate (GHB) and its physiological metabolites, gamma-aminobutyric acid (GABA), 1,4-butanediol (1,4-BD), and gamma-butyrolactone (GBL) in various animal tissues (kidney, muscle, heart, liver, blood, brain cortex, thalamus, hypothalamus, hippocampus, or pons), an original gas chromatographic/mass spectrometric method with a automated solid-phase extraction by Oasis MCX cartridges on a Gilson Aspec Xli was developed. Using such apparatus allowed the limit of detection (LOD) of target compounds to be significantly lowered (LOD: 0.027, 0.025, and 5.7 microg/mL for GHB, 1,4-BD, and GABA, respectively, in 200 microL or microg of sample). After validation of each analytical step, the satisfactory performances of the apparatus in conjunction with the rapidity and ease of the extraction step make it suitable for simultaneous assay of GHB, 1,4-BD, GBL, and GABA. The method was used to test the correlation between GHB levels in tissues obtained at different times after death of male Sprague-Dawley rats and the postmortem interval. Preliminary results show a linear increase of GHB levels in relation to time of death in thoracic blood and central nervous system of animals kept at 15 and 20 degrees C.

  12. Simultaneous analysis of gamma-hydroxybutyric acid and its precursors in urine using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wood, Michelle; Laloup, Marleen; Samyn, Nele; Morris, Michael R; de Bruijn, Ernst A; Maes, Robert A; Young, Michael S; Maes, Viviane; De Boeck, Gert

    2004-11-12

    We have developed a rapid method that enables the simultaneous analysis of gamma-hydroxybutyrate (GHB) and its precursors, i.e. gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in urine. The method comprised a simple dilution of the urine sample, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatographic separation was achieved using an Atlantis dC18 column, eluted with a mixture of formic acid and methanol. The method was linear from 1-80 mg/L for GHB and 1,4-BD and from 1-50 mg/L for GBL. The limit of quantification was 1 mg/L for all analytes. The procedure, which has a total analysis time (including sample preparation) of less than 12 min, was fully validated and applied to the analysis of 182 authentic urine samples; the results were correlated with a previously published GC-MS procedure and revealed a low prevalence of GHB-positive samples. Since no commercial immunoassay is available for the routine screening of GHB, this simple and rapid method should prove useful to meet the current increased demand for the measurement of GHB and its precursors.

  13. An overview of gamma-hydroxybutyric acid: pharmacodynamics, pharmacokinetics, toxic effects, addiction, analytical methods, and interpretation of results.

    Science.gov (United States)

    Andresen, H; Aydin, B E; Mueller, A; Iwersen-Bergmann, S

    2011-09-01

    Abuse of gamma-hydroxybutyric acid (GHB) has been known since the early 1990's, but is not as widespread as the consumption of other illegal drugs. However, the number of severe intoxications with fatal outcomes is comparatively high; not the least of which is brought about by the consumption of the currently legal precursor substances gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD). In regards to previous assumptions, addiction to GHB or its analogues can occur with severe symptoms of withdrawal. Moreover, GHB can be used for drug-facilitated sexual assaults. Its pharmacological effects are generated mainly by interaction with both GABA(B) and GHB receptors, as well as its influence on other transmitter systems in the human brain. Numerous analytical methods for determining GHB using chromatographic techniques were published in recent years, and an enzymatic screening method was established. However, the short window of GHB detection in blood or urine due to its rapid metabolism is a challenge. Furthermore, despite several studies addressing this problem, evaluation of analytical results can be difficult: GHB is a metabolite of GABA (gamma-aminobutyric acid); a differentiation between endogenous and exogenous concentrations has to be made. Apart from this, in samples with a longer storage interval and especially in postmortem specimens, higher levels can be measured due to GHB generation during this postmortem interval or storage time.

  14. 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.

  15. 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

  16. Rapid and facile detection of four date rape drugs in different beverages utilizing proton transfer reaction mass spectrometry (PTR-MS).

    Science.gov (United States)

    Jürschik, Simone; Agarwal, Bishu; Kassebacher, Thomas; Sulzer, Philipp; Mayhew, Christopher A; Märk, Tilmann D

    2012-09-01

    In this work, we illustrate the application of proton transfer reaction mass spectrometry (PTR-MS) in the field of food and drink safety. We present proof-of-principle measurements of four different drinks (water, tea, red wine and white wine) each spiked separately with four different date rape drugs (chloral hydrate, tricholorethanol, γ-butyrolactone and butanediol). At first, the ideal PTR-MS operating conditions (reduced electric field strength and monitoring the most abundant [fragment] ion) for detection of the drugs were determined utilizing a time-of-flight-based PTR-MS instrument. We then dissolved small quantities of the drugs (below the activation threshold for effects on humans) into the various types of drinks and detected them using a quadrupole-based PTR-MS instrument via two different sampling methods: (1) dynamic headspace sampling and (2) direct liquid injection. Both methods have their advantages and drawbacks. Only with dynamic headspace sampling can rape drug contaminations be detected within a timeframe of seconds, and therefore, this method is the most promising use of PTR-MS as a fast, sensitive and selective monitor for the detection of food and drink contamination.

  17. 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.

  18. Polystyrene-divinylbenzene stationary phases agglomerated with quaternized multi-walled carbon nanotubes for anion exchange chromatography.

    Science.gov (United States)

    Huang, Zhongping; Wu, Hongwei; Wang, Fengli; Yan, Wenwu; Guo, Weiqiang; Zhu, Yan

    2013-06-14

    This work explores the potential of multi-walled carbon nanotubes as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions. Polyelectrolytes with quaternary ammonium groups were introduced onto the carbon nanotube surface, based on condensation polymerization of 1,4-butanediol diglycidyl ether (BDDE) and methylamine (MA). Quaternized multi-walled carbon nanotubes (Q-MWCNTs) were electrostatically adsorbed onto the surface of sulfonated polystyrene-divinylbenzene (PS-DVB) beads to generate the anion exchanger, which were confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A 100mm×4.0mm i.d. column was packed with Q-MWCNTs agglomerated PS-DVB particles, with a capacity of 56μequiv./column. Separation of inorganic anions, such as F(-), Cl(-), NO2(-), Br(-), NO3(-), SO4(2-) and PO4(3-) were performed. The stationary phase was rigid, chemically stable and showed good ion-exchange characteristics.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus.

    Science.gov (United States)

    Amavizca, Edgar; Bashan, Yoav; Ryu, Choong-Min; Farag, Mohamed A; Bebout, Brad M; de-Bashan, Luz E

    2017-02-01

    Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga's physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications.

  2. 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.

  3. A novel gigaporous GSH affinity medium for high-speed affinity chromatography of GST-tagged proteins.

    Science.gov (United States)

    Huang, Yongdong; Zhang, Rongyue; Li, Juan; Li, Qiang; Su, Zhiguo; Ma, Guanghui

    2014-03-01

    Novel GSH-AP (phenoxyl agarose coated gigaporous polystyrene, Agap-co-PSt) microspheres were successfully prepared by introducing GSH ligand into hydrophilic AP microspheres pre-activated with 1,4-butanediol diglycidyl ether. The gigaporous structure and chromatographic properties of GSH-AP medium were evaluated and compared with commercial GSH Sepharose FF (GSH-FF) medium. The macropores (100-500nm) of gigaporous PSt microspheres were well maintained after coating with agarose and functionalized with GSH ligand. Hydrodynamic experiments showed that GSH-AP column had less backpressure and plate height than those of GSH-FF column at high flow velocity, which was beneficial for its use in high-speed chromatography. The presence of flow-through pores in GSH-AP microspheres also accelerated the mass transfer rate of biomolecules induced by convective flow, leading to high protein resolution and high dynamic binding capacity (DBC) of glutathione S-transferase (GST) at high flow velocity. High purity of GST and GST-tagged recombinant human interleukin-1 receptor antagonist (rhIL-1RA) were obtained from crude extract with an acceptable recovery yield within 1.5min at a velocity up to 1400cm/h. GSH-AP medium is promising for high-speed affinity chromatography for the purification of GST and GST-tagged proteins.

  4. 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.

  5. Wood bioindustry in the 21st century. 21 seki ni okeru mokuzai bio kogyo

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, T. (Research Association for systematic Utilization of Wood Components, Tokyo (Japan))

    1991-09-01

    For these about ten tears, technology has remarkably made progress to convert chemical contents of wood, i.e., cellulose, hemicellulose and lignin into effective materials. As for the fractionation of wood contents, a mutual bonding is noted to be physically or chemically made respectively among all cellulose, hemicellulose and lignin which are structural contents of wood cell wall. Therefore, each of those contents must be fractionated and separated to be converted and utilized, which methods comprise, among others, digestion and explosive crushing method, acetic acid digestion method, and fine powder saccharification method. For the chemical and biochemical conversion of fractionated contents, it was introduced that the hemicellulose is thoroughly hydrolyzed, converted into monosaccharide xylose, further reduced to xylitol and finally converted into xylooligosaccharide and reduced xylooligosaccharide. Also, butanediol can be biologically produced by conversion. As for the chemical and biochemical conversion and utilization of cellulose, the cellulose can be hydrolyzed to glucose with enzyme to derive sorbitol, acetone and acetic acid by fermentation, and many other kinds of material. 7 refs., 10 figs., 8 tabs.

  6. 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.

  7. Engineering nonphosphorylative metabolism to generate lignocellulose-derived products.

    Science.gov (United States)

    Tai, Yi-Shu; Xiong, Mingyong; Jambunathan, Pooja; Wang, Jingyu; Wang, Jilong; Stapleton, Cole; Zhang, Kechun

    2016-04-01

    Conversion of lignocellulosic biomass into value-added products provides important environmental and economic benefits. Here we report the engineering of an unconventional metabolism for the production of tricarboxylic acid (TCA)-cycle derivatives from D-xylose, L-arabinose and D-galacturonate. We designed a growth-based selection platform to identify several gene clusters functional in Escherichia coli that can perform this nonphosphorylative assimilation of sugars into the TCA cycle in less than six steps. To demonstrate the application of this new metabolic platform, we built artificial biosynthetic pathways to 1,4-butanediol (BDO) with a theoretical molar yield of 100%. By screening and engineering downstream pathway enzymes, 2-ketoacid decarboxylases and alcohol dehydrogenases, we constructed E. coli strains capable of producing BDO from D-xylose, L-arabinose and D-galacturonate. The titers, rates and yields were higher than those previously reported using conventional pathways. This work demonstrates the potential of nonphosphorylative metabolism for biomanufacturing with improved biosynthetic efficiencies.

  8. 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.

  9. 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).

  10. 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.

  11. Engineering Pichia pastoris for improved NADH regeneration: A novel chassis strain for whole-cell catalysis

    Directory of Open Access Journals (Sweden)

    Martina Geier

    2015-09-01

    Full Text Available Many synthetically useful reactions are catalyzed by cofactor-dependent enzymes. As cofactors represent a major cost factor, methods for efficient cofactor regeneration are required especially for large-scale synthetic applications. In order to generate a novel and efficient host chassis for bioreductions, we engineered the methanol utilization pathway of Pichia pastoris for improved NADH regeneration. By deleting the genes coding for dihydroxyacetone synthase isoform 1 and 2 (DAS1 and DAS2, NADH regeneration via methanol oxidation (dissimilation was increased significantly. The resulting Δdas1 Δdas2 strain performed better in butanediol dehydrogenase (BDH1 based whole-cell conversions. While the BDH1 catalyzed acetoin reduction stopped after 2 h reaching ~50% substrate conversion when performed in the wild type strain, full conversion after 6 h was obtained by employing the knock-out strain. These results suggest that the P. pastoris Δdas1 Δdas2 strain is capable of supplying the actual biocatalyst with the cofactor over a longer reaction period without the over-expression of an additional cofactor regeneration system. Thus, focusing the intrinsic carbon flux of this methylotrophic yeast on methanol oxidation to CO2 represents an efficient and easy-to-use strategy for NADH-dependent whole-cell conversions. At the same time methanol serves as co-solvent, inductor for catalyst and cofactor regeneration pathway expression and source of energy.

  12. Pretreatment of cellulosic biomass in improved production of ethanol and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ningjun; Gong, C.S.; Tsao, G.T. [Purdue Univ., West Lafayette, IN (United States); Yutang Huang [Jilin Corn Research and Development Center (China)

    1996-12-31

    A highly efficient process of simultaneous saccharification and fermentation (SSF) of cellulose using fungal cellulose and yeast to produce ethanol from lignocellulose pretreated with ammonia was developed. The process entails steeping the biomass with ammonia at ambient temperature to remove and extract lignin. This is followed by dilute acid hydrolysis at 100-108{degrees}C under atmospheric pressure to remove and recover a xylose-rich hemicellulose fraction as hemicellulose hydrolysate. This xylose-rich (92% xylose) hydrolysate was used as substrate for xylitol production by yeast and cellulose fraction was used for ethanol production in the SSF process with yeast. The same substrate was also used for 2,3-butanediol production in the SSF process with Klebsiella pneumonia. Experiments show that 98% of ammonia is recoverable for reuse and that the treated ground corn cob gives close to 86% theoretical yield of ethanol based on cellulose content. An ethanol concentration of over 60 g/L was obtained within 72 hours of SSF. 8 refs., 7 figs.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  16. 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.

  17. 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.

  18. Degradation of polyester polyurethane by a newly isolated soil bacterium, Bacillus subtilis strain MZA-75.

    Science.gov (United States)

    Shah, Ziaullah; Krumholz, Lee; Aktas, Deniz Fulya; Hasan, Fariha; Khattak, Mutiullah; Shah, Aamer Ali

    2013-11-01

    A polyurethane (PU) degrading bacterial strain MZA-75 was isolated from soil through enrichment technique. The bacterium was identified through 16S rRNA gene sequencing, the phylogenetic analysis indicated the strain MZA-75 belonged to genus Bacillus having maximum similarity with Bacillus subtilis strain JBE0016. The degradation of PU films by strain MZA-75 in mineral salt medium (MSM) was analyzed by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FT-IR) and gel permeation chromatography (GPC). SEM revealed the appearance of widespread cracks on the surface. FTIR spectrum showed decrease in ester functional group. Increase in polydispersity index was observed in GPC, which indicates chain scission as a result of microbial treatment. CO2 evolution and cell growth increased when PU was used as carbon source in MSM in Sturm test. Increase in both cell associated and extracellular esterases was observed in the presence of PU indicated by p-Nitrophenyl acetate (pNPA) hydrolysis assay. Analysis of cell free supernatant by gas chromatography-mass spectrometry (GC-MS) revealed that 1,4-butanediol and adipic acid monomers were produced. Bacillus subtilis strain MZA-75 can degrade the soft segment of polyester polyurethane, unfortunately no information about the fate of hard segment could be obtained. Growth of strain MZA-75 in the presence of these metabolites indicated mineralization of ester hydrolysis products into CO2 and H2O.

  19. 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

    2016-05-01

    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.

  20. 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.

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

    Science.gov (United States)

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

    2013-07-05

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

  3. 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.

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

    Science.gov (United States)

    Choi, Hwa-Jeong; Song, Young-Min; Chung, Ildoo; Ryu, Kwang-Sun; Jo, Nam-Ju

    2009-02-01

    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.

  5. 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

  6. 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.

  7. 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.

  8. Sensitive determination of parabens in human urine and serum using methacrylate monoliths and reversed-phase capillary liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Carrasco-Correa, Enrique Javier; Vela-Soria, Fernando; Ballesteros, Oscar; Ramis-Ramos, Guillermo; Herrero-Martínez, José Manuel

    2015-01-30

    A method for the determination of parabens in human urine and serum by capillary liquid chromatography (cLC) with UV-Vis and mass spectrometry (MS) detection using methacrylate ester-based monolithic columns has been developed. The influence of composition of polymerization mixture was studied. The optimum monolith was obtained with butyl methacrylate monomer at 60/40% (wt/wt) butyl methacrylate/ethylene dimethacrylate ratio and 50wt% porogens (composed of 36wt% of 1,4-butanediol, 54wt% 1-propanol and 10wt% water). Baseline resolution of analytes was achieved through a mobile phase of acetonitrile/water in gradient elution mode. Additionally, dispersive liquid-liquid microextraction (DLLME) was combined with both cLC-UV-Vis and cLC-MS to achieve the determination of parabens in human urine and serum samples with very low limits of detection. Satisfactory intra- and inter-day repeatabilities were obtained in UV-Vis and MS detection, although the latter provided lower detection limits (up to 300-fold) than the UV-Vis detection. Recoveries for the target analytes from spiked biological samples ranged from 95.2% to 106.7%. The proposed methodology for the ultra-low determination of parabens in human urine and serum samples is simple and fast, the consumption of reagents is very low, and very small samples can be analyzed.

  9. Development of an Integrated Biofuel and Chemical Refinery

    Energy Technology Data Exchange (ETDEWEB)

    Trawick, John [Genomatica, San Diego, CA (United States); Burk, Mark [Genomatica, San Diego, CA (United States); Barton, Nelson [Genomatica, San Diego, CA (United States)

    2017-02-06

    This project has demonstrated the level of commercial readiness for production of the industrial chemical, 1,4-butanediol (BDO), from lignocellulosic biomass by engineered E. coli. Targets were BDO titer, rate, and yield (TRY) and growth in lignocellulosic hydrolysates (Hz). A range of Hzs were used to assess limitations for biomass-to-BDO. Via adaptive evolution methods, whole-genome sequencing, and introduction of identified target genes, strains co-utilizing C5/ C6 sugars were made. The composition of Hz versus TRY led to a modified Hz composition. This was used in partnership with the DOE to redirect the project to focus on 1) several biomass Hz from new suppliers, 2) Hz specification due to the characteristics of the Genomatica BDO process, 3) a gene cassette to engineer any BDO producing strain for biomass, and 4) modified BDO recovery to more economically recover BDO at industry specifications. BDO TRY and growth of the E. coli strains were predictable based on Hz composition from several suppliers. This defined metrics for biomass Hz composition to achieve BDO TRY along with internal TEA to evaluate the economic potential of each modification to strain, Hz feed, and process. An improved biomass-to-BDO production strain reached BDO T-R in a 30 L fermentation above original objectives. Yield approached the proposed Y and modifications to BDO recovery were demonstrated. Genomatica is now in the position of being able to incorporate biomass feedstocks into the commercial GENO BDO process.

  10. STUDIES ON THE OXIDATION AND GRAFT COPOLYMERIZATION OF POLY(ETHER-URETHANE)

    Institute of Scientific and Technical Information of China (English)

    SUN Yanhui; QIU Kunyuan; FENG Xinde

    1983-01-01

    A new method of graft copolymerization of acrylamide (AAM) on poly(ether-urethane) (PEU)which was prepared from poly(tetramethylene ether) glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI) and ethylene diamine or butanediol extender was investigated. Hydroperoxide group was first introduced onto the surface of PEU through photo-oxidation in the presence of hydrogen peroxide, then it was reacted with ferrous ion or N,N-dimethyl toluidine (DMT) to initiate AAM graft copolymerization on PEU surface. The graft reaction could be carried out effectively at low temperature. The formation of graft copolymer has been verified by its water absorption % and the scanning electron microscopy photographs. Some model compounds of PEU soft segment and hard segment were synthesized in order to clarify the site of graft reaction. The results of oxidation and graft copolymerization of model compounds showed that this graft copolymerization possesses higher selectivity, and it takes place predominately at the polyether segments, because the ether linkage in soft segment is very sensitive to oxidation and can form hydroperoxide easily. Thus,the grafting site appears to be at a-carbon of the ether linkage.

  11. Production of 1,3-propanediol from glycerol using the newly isolated Klebsiella pneumoniae J2B.

    Science.gov (United States)

    Durgapal, Meetu; Kumar, Vinod; Yang, Taek Ho; Lee, Hee Jong; Seung, Doyoung; Park, Sunghoon

    2014-05-01

    Recently, novel Klebsiella pneumoniae J2B, which grows rapidly on glycerol as the carbon source without forming pathogenic and sticky lipopolysaccharides, was isolated. Current study examined the ability of K. pneumoniae J2B to produce 1,3-propanediol (PDO) from glycerol. To this end, a deletion mutant for lactate formation was constructed. The ldhA mutant strain produced negligible lactate but more 2,3-butanediol (BDO). When K. pneumoniae ΔldhA was cultivated in glycerol fed-batch mode, the PDO titer of 58.0 g/L with a yield of 0.35 g/g and an overall volumetric productivity of 1.3g/L/h were obtained. BDO was the main byproduct (26.6g/L). Less than 10 g/L of the other metabolites was produced. As PDO and other metabolites accumulated, the rate of PDO production decreased significantly due mainly to the toxic effects of these metabolites. This study highlights the potential of newly isolated K. pneumoniae J2B for the production of PDO from glycerol.

  12. Overexpressions of xylA and xylB in Klebsiella pneumoniae Lead to Enhanced 1,3-Propanediol Production by Cofermentation of Glycerol and Xylose.

    Science.gov (United States)

    Lu, Xinyao; Fu, Xiaomeng; Zong, Hong; Zhuge, Bin

    2016-07-28

    1,3-Propanediol (1,3-PD) is a valuable platform compound. Many studies have shown that the supplement of NADH plays a key role in the bioproduction of 1,3-PD from Klebsiella pneumoniae. In this study, the xylA and xylB genes from Escherichia coli were overexpressed individually or simultaneously in K. pneumoniae to improve the production of 1,3-PD by cofermentation of glycerol and xylose. Compared with the parent strain, the xylose consumption was significantly increased by the introduction of these two genes. The 1,3-PD titers were raised from 17.9 g/l to 23.5, 23.9, and 24.4 g/l, respectively, by the overexpression of xylA and xylB as well as their coexpression. The glycerol conversion rate (mol/mol) was enhanced from 54.1% to 73.8%. The concentration of 2,3-butanediol was increased by 50% at the middle stage but drastically decreased after that. The NADH and NADH/NAD(+) ratio were improved. This report suggests that overexpression of xylA or xylB is an effective strategy to improve the xylose assimilation rate to provide abundant reducing power for the biosynthesis of 1,3-PD in K. pneumoniae.

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

    Science.gov (United States)

    Hao, X; Taghavi, S; Xie, P; Orbach, M J; Alwathnani, H A; Rensing, C; Wei, G

    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 rhizobia or recombinant rhizobia with enhanced resistance, as well as co-inoculation with other plant growth promoting bacteria (PGPB) are discussed. However, the legume-rhizobia symbiosis appears to be sensitive to metals, and the effect of metal toxicity on the interaction between legumes and rhizobia is not clear. Therefore, to obtain the maximum benefits from legumes assisted by rhizobia for phytoremediation of metals, it is critical to have a good understanding of interactions between PGP traits, the symbiotic plant-rhizobia relationship and metals.

  14. Structural, thermal and surface characterization of thermoplastic polyurethanes based on poly(dimethylsiloxane

    Directory of Open Access Journals (Sweden)

    Pergal Marija V.

    2014-01-01

    Full Text Available In this study, the synthesis, structure and physical properties of two series of thermoplastic polyurethanes based on hydroxypropyl terminated poly(dimethylsiloxane (HP-PDMS or hydroxyethoxy propyl terminated poly(dimethylsiloxane (EO-PDMS as a soft segment, and 4,4’-methylenediphenyl diisocyanate and 1,4-butanediol as a hard segment were investigated. Each series is composed of samples prepared with a different soft segment. The polyurethanes were synthesized by two-step polyaddition in solution. The effects of the type and content of PDMS segments on the structure, thermal and surface properties of copolymers were studied by 1H NMR, 13C NMR and two-dimensional NMR (HMBC and ROESY spectroscopy, GPC, DSC, TGA, WAXS, SEM, water contact angle and water absorption measurements. Thermal properties investigated by DSC indicated that the presence of soft PDMS segments lowers the glass transition and melting temperatures of the hard phase as well as the degree of crystallinity. SEM analysis of copolymers with a lower soft segment content confirmed the presence of spherulite superstructures, which arise from the crystallization of the hard segments. When compared with polyurethanes prepared from HP-PDMS, copolymers synthesized from EO-PDMS with the same content of the soft segments have higher degree of crystallinity, better thermal stability and less hydrophobic surface. Our results show that the synthesized polyurethanes have good thermal and surface properties, which could be further modified by changing the type or content of the soft segments.

  15. 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.

  16. Hydrotreating of wheat straw in toluene and ethanol.

    Science.gov (United States)

    Murnieks, Raimonds; Kampars, Valdis; Malins, Kristaps; Apseniece, Lauma

    2014-07-01

    In the present work, wheat straw was hydroliquefied at a temperature of 300°C for 4h in ethanol or toluene in order to obtain bio-components which are useful for fuel purposes. The experiments were performed in a 100mL batch reactor under hydrogen pressure of 70 bar. Typically, 2g of straw and 0.1g of catalyst (66%Ni/SiO2-Al2O3) were dispersed in 15 g of solvent. The main compounds of the oil produced during the liquefaction of hemicellulose, cellulose and lignin of wheat straw in both solvents are: tetrahydrofuran-2-methanol, 1,2-butanediol and butyrolactone. Besides the mentioned compounds, ethanol favoured the decomposition of bigger molecules to short-chain alcohols such as 1-butanol, 1,2-propanediol and 1,2-ethanediol. Toluene contributes to the production of furans and other cyclic compounds. The light fractions distilled together with the solvent also contain the following: 1-propanol, 2-methyl-cyclopentanone, acetic acid and ethyl acetate.

  17. 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.

  18. Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus

    Science.gov (United States)

    Amavizca, Edgar; Bashan, Yoav; Ryu, Choong-Min; Farag, Mohamed A.; Bebout, Brad M.; de-Bashan, Luz E.

    2017-01-01

    Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga’s physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications. PMID:28145473

  19. Crystallization and preliminary X-ray analysis of a Kunitz-type inhibitor, textilinin-1 from Pseudonaja textilis textilis

    Energy Technology Data Exchange (ETDEWEB)

    Millers, Emma-Karin I. [School of Molecular and Microbial Sciences, University of Queensland, Brisbane 4072, QLD (Australia); Masci, Paul P. [School of Medicine, Southern Division, University of Queensland, Princess Alexandra Hospital, Woolloongabba, Brisbane 4102, QLD (Australia); Lavin, Martin F. [The Queensland Cancer Fund Research Unit, The Queensland Institute of Medical Research, PO Box, Royal Brisbane Hospital, Herston, Brisbane 4029, QLD (Australia); Jersey, John de; Guddat, Luke W., E-mail: luke.guddat@uq.edu.au [School of Molecular and Microbial Sciences, University of Queensland, Brisbane 4072, QLD (Australia)

    2006-07-01

    Crystals of a canonical inhibitor of plasmin from Australian Brown snake venom has been obtained. In complex with trypsin these diffract to 2.0 Å resolution, while the free inhibitor diffracts to 1.63 Å. Textilinin-1 (Txln-1), a Kunitz-type serine protease inhibitor, is a 59-amino-acid polypeptide isolated from the venom of the Australian Common Brown snake Pseudonaja textilis textilis. This molecule has been suggested as an alternative to aprotinin, also a Kunitz-type serine protease inhibitor, for use as an anti-bleeding agent in surgical procedures. Txln-1 shares only 47% amino-acid identity to aprotinin; however, six cysteine residues in the two peptides are in conserved locations. It is therefore expected that the overall fold of these molecules is similar but that they have contrasting surface features. Here, the crystallization of recombinant textilinin-1 (rTxln-1) as the free molecule and in complex with bovine trypsin (229 amino acids) is reported. Two organic solvents, phenol and 1,4-butanediol, were used as additives to facilitate the crystallization of free rTxln-1. Crystals of the rTxln-1–bovine trypsin complex diffracted to 2.0 Å resolution, while crystals of free rTxln-1 diffracted to 1.63 Å resolution.

  20. Thermal expansion of vitrified blood vessels permeated with DP6 and synthetic ice modulators.

    Science.gov (United States)

    Eisenberg, David P; Taylor, Michael J; Jimenez-Rios, Jorge L; Rabin, Yoed

    2014-06-01

    This study provides thermal expansion data for blood vessels permeated with the cryoprotective cocktail DP6, when combined with selected synthetic ice modulators (SIMs): 12% polyethylene glycol 400, 6% 1,3-cyclohexanediol, and 6% 2,3-butanediol. The general classification of SIMs includes molecules that modulate ice nucleation and growth, or possess properties of stabilizing the amorphous state, by virtue of their chemical structure and at concentrations that are not explained on a purely colligative basis. The current study is part of an ongoing effort to characterize thermo-mechanical effects on structural integrity of cryopreserved materials, where thermal expansion is the driving mechanism to thermo-mechanical stress. This study focuses on the lower part of the cryogenic temperature range, where the cryoprotective agent (CPA) behaves as a solid for all practical applications. By combining results obtained in the current study with literature data on the thermal expansion in the upper part of the cryogenic temperature range, unified thermal expansion curves are presented.

  1. Evaluation of two matrix materials intended for fiber-reinforced polymers.

    Science.gov (United States)

    Segerström, Susanna; Meriç, Gökçe; Knarvang, Torbjørn; Ruyter, I Eystein

    2005-10-01

    Two matrix resins for fiber composites that remain in a fluid state during storage and handling before polymerization were evaluated. The resin mixtures, based on methyl methacrylate (MMA), were produced with two different cross-linking agent systems: 1,4-butanediol dimethacrylate and ethylene glycol dimethacrylate or diethylene glycol dimethacrylate. Water sorption, water solubility, water uptake and residual MMA monomer were determined. Thermomechanical analysis was used to determine linear dimensional changes as a function of temperature. Flexural strength and modulus as well as fracture work and the maximum stress intensity factor were determined. The results revealed similar values for both matrix polymers regarding water sorption, water solubility, water uptake, residual MMA monomer (0.5 wt% (+/- 0.03)) and coefficient of linear thermal expansion. Flexural strength for polymer B was 68.7 MPa (+/- 9.8) compared to 56.0 MPa (+/- 13.3) for polymer A when tested dry and 64 MPa (+/- 6.1) compared to (54 MPa (+/- 3.3) when water-saturated. Fracture toughness tests showed higher maximum stress intensity factor values for polymer B (0.75 +/- 0.17) MPa x m1/2 than for polymer A (0.55 +/- 0.12) MPa x m1/2. The resin binders showed an appropriate consistency while remaining in a fluid state during storage and manipulation.

  2. Synthesis and characterization of thermoplastic polyurethane/nanoclay composites

    Energy Technology Data Exchange (ETDEWEB)

    Pizzatto, Leandro [Autotravi Borrachas e Plasticos Ltda, Caxias do Sul (Brazil); Lizot, Analice; Fiorio, Rudinei [Departamento de Engenharia Quimica, Universidade de Caxias do Sul, Caxias do Sul (Brazil); Amorim, Cintia L.; Machado, Giovanna [Programa de Pos-Graduacao em Materiais, Universidade de Caxias do Sul, Caxias do Sul (Brazil); Giovanela, Marcelo [Departamento de Fisica e Quimica, Universidade de Caxias do Sul, Caxias do Sul (Brazil); Zattera, Ademir J. [Departamento de Engenharia Quimica, Universidade de Caxias do Sul, Caxias do Sul (Brazil); Crespo, Janaina S. [Grupo de Materiais Elastomericos, Universidade de Caxias do Sul, Caxias do Sul (Brazil)], E-mail: jscrespo@ucs.br

    2009-03-01

    In this study thermoplastic polyurethane (TPU) composites were obtained with different nanoclay contents (0, 1, 3 for all cases and 10 wt.% in some cases). The nanoclay Cloisite (registered) 30B (C30B) 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 polyesterpolyol (molecular weight 2000 g mol{sup -1}) and diphenylmethanediisocyanate (MDI) 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, before and after ageing, 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 performed through determination of the tensile and tear strengths. 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)

  3. 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)

  4. Effect of impregnating agent and relative humidity on surface characteristics of sorbents determined by inverse gas chromatography.

    Science.gov (United States)

    Kasperkowiak, M; Kołodziejek, J; Strzemiecka, B; Voelkel, A

    2013-05-03

    Sorbents that potentially can be used for separation of the products of biotechnological conversion of glycerol were examined. Properties of Zeolite 5A, resins: Amberlite, Diaion and their samples impregnated with an aqueous solutions of 1,2,3-propanetriol, 1,3-propanediol, 2,3-butanediol, acetic acid, succinic acid and model fermentation broth were investigated. Because surface properties will probably depend on the ambient humidity the IGC experiments were carried out under different conditions of relative humidity RH=0, 40 and 80%. Activity of the sorbents surface was expressed by the value of the dispersive component of the free surface energy. Inverse gas chromatography was also used to express acid-base properties of materials described by KA and KD parameters. The changes in the activity of investigated sorbents significantly varied depending on the type of impregnating agent. Moreover, the obtained results demonstrate that humidity can strongly influence, in some cases, the dispersive component of the free surface energy and the ability to specific interactions (KA and KD).

  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.

  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 (κexp) responsible for the polar interactions within polyurethane chains were calculated by (1)H NMR method. Obtained results were confronted with the analogous parameter values (κtheor) 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 κexp 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Study on the structure and morphology of supramolecular shape memory polyurethane containing pyridine moieties

    Science.gov (United States)

    Chen, S. J.; Hu, J. L.; Chen, S. G.; Zhang, C. L.

    2011-06-01

    Fabricating smart materials has been an attractive research topic in recent years. In this study, a series of pyridine-containing shape memory polyurethanes (Py-SMPUs) with different pyridine contents were synthesized. Based on the theoretical analysis, the structure and morphology of Py-SMPUs were studied systematically with FT-IR, DSC, WAXD, DMA, AFM, etc. Results show that a hydrogen-bonded supramolecular structure is formed in the Py-SMPUs. Hydrogen bonds present in the urethane group and pyridine ring are the most favorable hydrogen bonds which play an important role in the movement of the polymer chain. Microphase separation consisting of a soft phase and hard phase occurs in the Py-SMPUs. The soft phase is influenced greatly by the N, N-bis(2-hydroxyl ethyl) isonicotinamide (BINA) unit and the hard phase is mainly a result of the hexamethylene diisocyanate and 1,4-butanediol (HDI-BDO) units. As the BINA content decreases, the soft phase tends to change gradually from a continuous amorphous phase to a droplet-like dispersion phase, whereas the hard phase develops from a droplet-like dispersion amorphous phase to a continuous crystalline phase.

  9. 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.

  10. 水性聚氨酯性能的影响因素研究%Study on Factors Influencing the Performance of Waterborne Polyurethane

    Institute of Scientific and Technical Information of China (English)

    王安民

    2009-01-01

    Series of waterborne polyurethane dispersion and film therefrom are prepared under different conditions with poly (tetramethylene oxide) (PTMG-1000), isophorone diisocyanate (IPDI) and TDI as main materials, dimethylol propionic acid (DMPA) as hydrophilic chain extender, 1,4-butanediol (BDO) and ethylenediamine (EA) as micromolecular chain extender. The effects of molecular structure and dispersion conditions on the stability of emulsion and properties of emulsion film are analyzed by studying the hardness, water absorption, adhesion and etc. of the emulsion film.%以聚四氢呋喃二醇(PTMG-1000)、异佛尔酮二异氰酸酯(IPDI)、甲苯2,4-二异氰酸酯(TDI)为主要原料,二羟甲基丙酸(DMPA)为亲水性扩链剂,1,4-丁二醇(BDO)和乙二胺(EA)为小分子扩链剂,在不同条件下制备了系列水性聚氨酯分散体并制备胶膜.通过对胶膜硬度、吸水率以及附着力等的研究,分析分子结构及分散条件对乳液稳定性和胶膜性能的影响.

  11. Study on the Preparation Technique of Waterborne Polyurethane Dispersion%水性聚氨酯分散体制备技术的研究

    Institute of Scientific and Technical Information of China (English)

    孙道兴; 崔琳

    2012-01-01

    The series of waterborne polyurethane dispersion were prepared in different conditions by use of IPDI, TDI, polycarbonate diol ( L5652-2000 )and polytetrahydrofuran glycol ( PTMG-2000 )as main materials, dimethylol propionic acid as hydrophilic monomer, and 1, 4-butanediol (BDO)and ethanediamine as chain extender. The influences of molecular structure and dispersing condition on the dispersion stability and film performance were analyzed by the study of hardness, water absorption and adhesion of films.%以异佛尔酮二异氰酸酯(IPDI)、甲苯-2,4-二异氰酸酯(TDI)、聚碳酸酯二醇(L5652—2000)和聚四氢呋喃二醇(PTMG-2000)为主要原料,2,2-二羟甲基丙酸(DMPA)为亲水单体,1,4-丁二醇(BDO)和乙二胺(EA)为扩链剂,在不同条件下制备了系列水性聚氨酯分散体。通过对胶膜硬度、吸水率以及附着力等的研究,分析了分子结构及分散条件对分散体稳定性和胶膜性能的影响。

  12. Preparation and investigation of the gas separation properties of polyurethane-TiO{sub 2} nanocomposite membranes

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Morteza; Afarani, Hajar Taheri; Tarashi, Zohreh [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-01-15

    The effect of TiO{sub 2} nanoparticles on the gas separation properties of polyurethane has been investigated. Polyurethane was synthesized using hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO) as hard segment and poly(tetramethylene glycol) (PTMG, 2,000 g/mol) as soft segment. The synthesized polymer was in a 1 : 2 : 1 molar ratio of polyol : diisocyanate : chain extender through bulk two-step polymerization. PU membranes were prepared by thermal phase inversion method. Scanning electron microscopy (SEM), X-ray diffraction and Fourier Transform Infrared (FTIR) analyses characterized the prepared membranes. FTIR and SEM results indicate the good interaction between particles and polymer matrix and also the nanoscale dispersion of TiO{sub 2} particles in polymer matrix. Gas permeation properties of PU-TiO{sub 2} nanocomposite membranes with TiO{sub 2} contents up to 30 wt% were studied for N{sub 2}, O{sub 2}, CH{sub 4} and CO{sub 2} gases at 10 bar and 25 .deg. C. Results suggest a decrease in permeability of studied gases and increase in gas selectivities as TiO{sub 2} content increases.

  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. Comparison of analytical protein separation characteristics for three amine-based capillary-channeled polymer (C-CP) stationary phases.

    Science.gov (United States)

    Jiang, Liuwei; Marcus, R Kenneth

    2016-02-01

    Capillary-channeled polymer (C-CP) fiber stationary phases are finding utility in the realms of protein analytics as well as downstream processing. We have recently described the modification of poly(ethylene terephthalate) (PET) C-CP fibers to affect amine-rich phases for the weak anion-exchange (WAX) separation of proteins. Polyethylenimine (PEI) is covalently coupled to the PET surface, with subsequent cross-linking imparted by treatment with 1,4-butanediol diglycidyl ether (BUDGE). These modifications yield vastly improved dynamic binding capacities over the unmodified fibers. We have also previously employed native (unmodified) nylon 6 C-CP fibers as weak anion/cation-exchange (mixed-mode) and hydrophobic interaction chromatography (HIC) phases for protein separations. Polyamide, nylon 6, consists of amide groups along the polymer backbone, with primary amines and carboxylic acid end groups. The analytical separation characteristics of these three amine-based C-CP fiber phases are compared here. Each of the C-CP fiber columns in this study was shown to be able to separate a bovine serum albumin/hemoglobin/lysozyme mixture at high mobile phase linear velocity (∼70 mm s(-1)) but with different elution characteristics. These differences reflect the types of protein-surface interactions that are occurring, based on the active group composition of the fiber surfaces. This study provides important fundamental understanding for the development of surface-modified C-CP fiber columns for protein separation.

  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

    2011-01-06

    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. Viscosity-dependent drain current noise of AlGaN/GaN high electron mobility transistor in polar liquids

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J. Y.; Hsu, C. P.; Kang, Y. W.; Fang, K. C.; Kao, W. L.; Yao, D. J.; Chen, C. C.; Li, S. S.; Yeh, J. A.; Wang, Y. L. [Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 300, Taiwan (China); Lee, G. Y.; Chyi, J. I. [Department of Electrical engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan (China); Hsu, C. H. [Division of Medical Engineering, National Health Research Institutes, MiaoLi, Taiwan (China); Huang, Y. F. [Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Ren, F. [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2013-11-28

    The drain current fluctuation of ungated AlGaN/GaN high electron mobility transistors (HEMTs) measured in different fluids at a drain-source voltage of 0.5 V was investigated. The HEMTs with metal on the gate region showed good current stability in deionized water, while a large fluctuation in drain current was observed for HEMTs without gate metal. The fluctuation in drain current for the HEMTs without gate metal was observed and calculated as standard deviation from a real-time measurement in air, deionized water, ethanol, dimethyl sulfoxide, ethylene glycol, 1,2-butanediol, and glycerol. At room temperature, the fluctuation in drain current for the HEMTs without gate metal was found to be relevant to the dipole moment and the viscosity of the liquids. A liquid with a larger viscosity showed a smaller fluctuation in drain current. The viscosity-dependent fluctuation of the drain current was ascribed to the Brownian motions of the liquid molecules, which induced a variation in the surface dipole of the gate region. This study uncovers the causes of the fluctuation in drain current of HEMTs in fluids. The results show that the AlGaN/GaN HEMTs may be used as sensors to measure the viscosity of liquids within a certain range of viscosity.

  17. Engineering and Evolution of Saccharomyces cerevisiae to Produce Biofuels and Chemicals.

    Science.gov (United States)

    Turner, Timothy L; Kim, Heejin; Kong, In Iok; Liu, Jing-Jing; Zhang, Guo-Chang; Jin, Yong-Su

    2016-12-03

    To mitigate global climate change caused partly by the use of fossil fuels, the production of fuels and chemicals from renewable biomass has been attempted. The conversion of various sugars from renewable biomass into biofuels by engineered baker's yeast (Saccharomyces cerevisiae) is one major direction which has grown dramatically in recent years. As well as shifting away from fossil fuels, the production of commodity chemicals by engineered S. cerevisiae has also increased significantly. The traditional approaches of biochemical and metabolic engineering to develop economic bioconversion processes in laboratory and industrial settings have been accelerated by rapid advancements in the areas of yeast genomics, synthetic biology, and systems biology. Together, these innovations have resulted in rapid and efficient manipulation of S. cerevisiae to expand fermentable substrates and diversify value-added products. Here, we discuss recent and major advances in rational (relying on prior experimentally-derived knowledge) and combinatorial (relying on high-throughput screening and genomics) approaches to engineer S. cerevisiae for producing ethanol, butanol, 2,3-butanediol, fatty acid ethyl esters, isoprenoids, organic acids, rare sugars, antioxidants, and sugar alcohols from glucose, xylose, cellobiose, galactose, acetate, alginate, mannitol, arabinose, and lactose.

  18. 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.

  19. Effect of roasting on the volatile constituents of Trichosanthes kirilowii seeds

    Directory of Open Access Journals (Sweden)

    Shimin Wu

    2014-09-01

    Full Text Available Roasted Trichosanthes kirilowii seeds have much more intense flavor than the raw seeds, and are commonly used as food and in the preparations of many medicinal formulations. Volatile constituents in the raw and roasted T. kirilowii seeds were separated by simultaneous distillation and extraction, and analyzed by gas chromatography–mass spectrometry on two capillary gas chromatography columns of different polarities (DB-WAX and HP-1. A total of 40 volatile compounds were identified in the raw seeds, with pentanal, 2-pentanol, styrene, (Z-2-heptenal, (+-calarene, and α-muurolene being the predominant compounds; 40 volatile compounds were also identified in the roasted seeds, with 3-methylbutanal, ethanol, 2-butanol, 2,3-butanediol, (E,E-2,4-nonadienal, and 2-isopropyl-5-methyl-9-methylene-bicyclo[4.4.0]dec-1-ene being the most abundant compounds. A total of 15 compounds, mostly aldehydes, were common in both seeds. Roasting of T. kirilowii seeds resulted in a significant decrease in the levels of sesquiterpenes and short-chain aliphatic aldehydes. By contrast, high concentrations of 3-methylbutanal, ethanol, 2-butanol, and alkyl pyrazines were generated, which was responsible for the unique flavor of the roasted seeds. The study results may be useful for optimizing the roasting process and oil processing of T. kirilowii seeds.

  20. 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.

  1. 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.

  2. Effect of Added Salts or Polyols on the Cloud Point and the Liquid-Crystalline Structures of Polyoxyethylene-Modified Silicone.

    Science.gov (United States)

    Iwanaga; Kunieda

    2000-07-15

    The effect of added salts (NaCl, Na(2)SO(4), and NaSCN) or polyols (glycerin (Gly), 1,3-butanediol (1,3-BD), ethylene glycol (EG), and polyethylene glycol (PEG400)) on the hexagonal liquid-crystalline structure of polyoxyethylene-modified silicone was investigated by means of small angle X-ray scattering (SAXS). The effective cross-sectional area of the lipophilic part of the aggregate, a(s), in the hexagonal phase decreases upon the addition of salts, on one hand, lowering the cloud point in the dilute aqueous siloxane surfactant solutions. On the other hand, if added salt raises the cloud point, the a(s) increases. Similar results were obtained in the case of the addition of polyols. Since the a(s) mainly depends on the EO chain length, the above results are direct evidence that the hydration or dehydration of the EO chain is affected by these additives. The static fluorescence probe method was applied to the Gly and 1,3-BD systems using 8-anilino-1-naphthalene-sulfonic acid, ANS, to know the change in hydration of the EO chains. In the Gly system, the hydration of the EO chain monotonically decreases whereas 1,3-BD first increases the hydration and then decreases it at high 1,3-BD content. These results are very consistent with the SAXS and cloud temperature results. Copyright 2000 Academic Press.

  3. 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.

  4. 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.

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reiznautt, Quelen B. [Laboratory of Instrumentation and Molecular Dynamics, Department of Physical Chemistry, Chemistry Institute, Federal University of Rio Grande do Sul, Av. Bento Goncalves 9500, CEP: 91501-970, Porto Alegre (Brazil); Garcia, Irene T.S. [Department of Analytical and Inorganic Chemistry, Chemistry and Geosciences Institute, Federal University of Pelotas, 96010-900, Pelotas (Brazil); Samios, Dimitrios, E-mail: dsamios@iq.ufrgs.br [Laboratory of Instrumentation and Molecular Dynamics, Department of Physical Chemistry, Chemistry Institute, Federal University of Rio Grande do Sul, Av. Bento Goncalves 9500, CEP: 91501-970, Porto Alegre (Brazil)

    2009-08-31

    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 {sup 1}H and {sup 13}C 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

  9. 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.

  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. Response of the cytoplasmic and membrane proteome of Corynebacterium glutamicum ATCC 13032 to pH changes

    Directory of Open Access Journals (Sweden)

    Poetsch Ansgar

    2008-12-01

    Full Text Available Abstract Background C. glutamicum has traditionally been grown in neutral-pH media for amino acid production, but in a previous article we reported that this microorganism is a moderate alkaliphile since it grows optimally at pH 7.0–9.0, as shown in fermentor studies under tightly controlled pH conditions. We determined the best pH values to study differential expression of several genes after acidic or basic pH conditions (pH 6.0 for acidic expression and pH 9.0 for alkaline expression. Thus, it was interesting to perform a detailed analysis of the pH-adaptation response of the proteome of C. glutamicum ATCC 13032 to clarify the circuits involved in stress responses in this bacterium. In this paper we used the above indicated pH conditions, based on transcriptional studies, to confirm that pH adaptation results in significant changes in cytoplasmatic and membrane proteins. Results The cytoplasmatic and membrane proteome of Corynebacterium glutamicum ATCC 13032 at different pH conditions (6.0, 7.0 and 9.0 was analyzed by classical 2D-electrophoresis, and by anion exchange chromatography followed by SDS-PAGE (AIEC/SDS-PAGE. A few cytoplasmatic proteins showed differential expression at the three pH values with the classical 2D-technique including a hypothetical protein cg2797, L-2.3-butanediol dehydrogenase (ButA, and catalase (KatA. The AIEC/SDS-PAGE technique revealed several membrane proteins that respond to pH changes, including the succinate dehydrogenase complex (SdhABCD, F0F1-ATP synthase complex subunits b, α and δ (AtpF, AtpH and AtpA, the nitrate reductase II α subunit (NarG, and a hypothetical secreted/membrane protein cg0752. Induction of the F0F1-ATP synthase complex β subunit (AtpD at pH 9.0 was evidenced by Western analysis. By contrast, L-2.3-butanediol dehydrogenase (ButA, an ATPase with chaperone activity, the ATP-binding subunit (ClpC of an ATP-dependent protease complex, a 7 TMHs hypothetical protein cg0896, a conserved

  12. 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

  13. 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

  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. 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.

  16. 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

  17. 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

  18. 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.

  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. 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.

  1. 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.

  2. Design of a microchannel-nanochannel-microchannel array based nanoelectroporation system for precise gene transfection.

    Science.gov (United States)

    Gao, Keliang; Li, Lei; He, Lingna; Hinkle, Kevin; Wu, Yun; Ma, Junyu; Chang, Lingqian; Zhao, Xi; Perez, Daniel Gallego; Eckardt, Sigrid; McLaughlin, John; Liu, Boyu; Farson, Dave F; Lee, L James

    2014-03-12

    A micro/nano-fabrication process of a nanochannel electroporation (NEP) array and its application for precise delivery of plasmid for non-viral gene transfection is described. A dip-combing device is optimized to produce DNA nanowires across a microridge array patterned on the polydimethylsiloxane (PDMS) surface with a yield up to 95%. Molecular imprinting based on a low viscosity resin, 1,4-butanediol diacrylate (1,4-BDDA), adopted to convert the microridge-nanowire-microridge array into a microchannel-nanochannel-microchannel (MNM) array. Secondary machining by femtosecond laser ablation is applied to shorten one side of microchannels from 3000 to 50 μm to facilitate cell loading and unloading. The biochip is then sealed in a packaging case with reservoirs and microfluidic channels to enable cell and plasmid loading, and to protect the biochip from leakage and contamination. The package case can be opened for cell unloading after NEP to allow for the follow-up cell culture and analysis. These NEP cases can be placed in a spinning disc and up to ten discs can be piled together for spinning. The resulting centrifugal force can simultaneously manipulate hundreds or thousands of cells into microchannels of NEP arrays within 3 minutes. To demonstrate its application, a 13 kbp OSKM plasmid of induced pluripotent stem cell (iPSC) is injected into mouse embryonic fibroblasts cells (MEFCs). Fluorescence detection of transfected cells within the NEP biochips shows that the delivered dosage is high and much more uniform compared with similar gene transfection carried out by the conventional bulk electroporation (BEP) method.

  3. 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.

  4. 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.

  5. Transcriptional responses to sucrose mimic the plant-associated life style of the plant growth promoting endophyte Enterobacter sp. 638.

    Science.gov (United States)

    Taghavi, Safiyh; Wu, Xiao; Ouyang, Liming; Zhang, Yian Biao; Stadler, Andrea; McCorkle, Sean; Zhu, Wei; Maslov, Sergei; van der Lelie, Daniel

    2015-01-01

    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.

  6. Epigenetic events determine tissue-specific toxicity of inhalational exposure to the genotoxic chemical 1,3-butadiene in male C57BL/6J mice.

    Science.gov (United States)

    Chappell, Grace; Kobets, Tetyana; O'Brien, Bridget; Tretyakova, Natalia; Sangaraju, Dewakar; Kosyk, Oksana; Sexton, Kenneth G; Bodnar, Wanda; Pogribny, Igor P; Rusyn, Ivan

    2014-12-01

    1,3-Butadiene (BD), a widely used industrial chemical and a ubiquitous environmental pollutant, is a known human carcinogen. Although genotoxicity is an established mechanism of the tumorigenicity of BD, epigenetic effects have also been observed in livers of mice exposed to the chemical. To better characterize the diverse molecular mechanisms of BD tumorigenicity, we evaluated genotoxic and epigenotoxic effects of BD exposure in mouse tissues that are target (lung and liver) and non-target (kidney) for BD-induced tumors. We hypothesized that epigenetic alterations may explain, at least in part, the tissue-specific differences in BD tumorigenicity in mice. We evaluated the level of N-7-(2,3,4-trihydroxybut-1-yl)guanine adducts and 1,4-bis-(guan-7-yl)-2,3-butanediol crosslinks, DNA methylation, and histone modifications in male C57BL/6 mice exposed to filtered air or 425 ppm of BD by inhalation (6 h/day, 5 days/week) for 2 weeks. Although DNA damage was observed in all three tissues of BD-exposed mice, variation in epigenetic effects clearly existed between the kidneys, liver, and lungs. Epigenetic alterations indicative of genomic instability, including demethylation of repetitive DNA sequences and alterations in histone-lysine acetylation, were evident in the liver and lung tissues of BD-exposed mice. Changes in DNA methylation were insignificant in the kidneys of treated mice, whereas marks of condensed heterochromatin and transcriptional silencing (histone-lysine trimethylation) were increased. These modifications may represent a potential mechanistic explanation for the lack of tumorigenesis in the kidney. Our results indicate that differential tissue susceptibility to chemical-induced tumorigenesis may be attributed to tissue-specific epigenetic alterations.

  7. Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content.

    Science.gov (United States)

    Li, Yanbing; Nishino, Naoki

    2013-09-01

    The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages.

  8. 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

  9. Analysis of GHB and 4-methyl-GHB in postmortem matrices after long-term storage.

    Science.gov (United States)

    Marinetti, Laureen J; Isenschmid, Daniel S; Hepler, Bradford R; Kanluen, Sawait

    2005-01-01

    Postmortem heart blood, peripheral blood, vitreous humor, urine, and bile specimens from 26 autopsy cases were analyzed for the presence of gamma-hydroxybutyric acid (GHB) and gamma-methyl gamma-hydroxybutyric acid (4-Me-GHB) after long-term freezer storage. Cases were selected for which exogenous GHB, gamma-butyrolactone (GBL), gamma valerolactone (GVL), or 1,4-butanediol use was not suspected. One documented positive GHB case subjected to the same storage conditions was also evaluated for comparison. Specimens did not contain any preservatives or additives except heart blood, which contained sodium fluoride (2% w/v). The results of the analysis for GHB in vitreous humor (n = 26) demonstrated, with one exception, concentrations below the limit of detection for the method (5 mg/L). In the exception case, the value was determined to be 7 mg/L. Documented cases of GHB positive fatalities showed vitreous humor concentrations (n = 6) that exceeded this range by a factor of 12 or more. There was no apparent relationship between storage times and GHB concentrations. The data developed in this study demonstrate a postmortem endogenous range for GHB in vitreous humor that is less than or equal to 7 mg/L. Studies of the stored GHB-positive case demonstrated no significant change in concentration over the time period studied. None of the specimens analyzed in this study contained detectable amounts of 4-Me-GHB. This would support the contention that when 4-Me-GHB is detected, it is most likely due to the exogenous consumption of GVL.

  10. A hydrophilic interaction liquid chromatography electrospray tandem mass spectrometry method for the simultaneous determination of γ-hydroxybutyrate and its precursors in forensic whole blood.

    Science.gov (United States)

    Sørensen, Lambert K; Hasselstrøm, Jørgen B

    2012-10-10

    A liquid-chromatography-tandem-mass-spectrometry method using pneumatically assisted electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of γ-hydroxybutyric acid (GHB), γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in human ante-mortem and post-mortem whole blood. The blood proteins were precipitated using a mixture of methanol and acetonitrile, and the extract was cleaned-up by passage through a polymeric strong cation exchange sorbent. Separation of the analytes and their structural isomers was obtained using a column with a zwitterionic stationary phase. Matrix-matched calibrants, combined with isotope dilution, were used for quantitative analysis. GHB was determined in both positive and negative ion modes. The relative intra-laboratory reproducibility standard deviations were better than 10% and 6% for blood samples at concentrations of 2 mg/L and 20-150 mg/L, respectively. The mean true extraction recoveries were 80% for GHB and greater than 90% for GBL and 1,4-BD at concentration levels of 20-50 mg/L. The limits of detection were approximately 0.5 mg/L for GHB and GBL, and 0.02 mg/L for 1,4-BD in ante-mortem blood. The corresponding lower limits of quantification were less than 1 mg/L for GHB and GBL, and less than 0.1 mg/L for 1,4-BD. GBL was unstable in whole blood freshly preserved with a sodium fluoride oxalate mixture, but the stability could be improved significantly by preservation with a sodium fluoride citrate EDTA mixture.

  11. 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.

  12. Quantitative Analysis of Humectants in Tobacco Products Using Gas Chromatography (GC with Simultaneous Mass Spectrometry (MSD and Flame Ionization Detection (FID

    Directory of Open Access Journals (Sweden)

    Rainey CL

    2014-12-01

    Full Text Available This paper describes the modification of an existing gas chromatographic (GC method to incorporate simultaneous mass spectrometric (MSD and flame ionization detection (FID into the analysis of tobacco humectants. Glycerol, propylene glycol, and triethylene glycol were analyzed in tobacco labeled as roll-your-own (RYO, cigar, cigarette, moist snuff, and hookah tobacco. Tobacco was extracted in methanol containing 1,3-butanediol (internal standard, filtered, and separated on a 15 m megabore DB-Wax column. Post-column flow was distributed using a microfluidic splitter between the MSD and FID for simultaneous detection. The limits of detection for the FID detector were 0.5 μg/mL (propylene glycol and triethylene glycol and 0.25 μg/mL (glycerol with a linear range of 2-2000 μg/mL (propylene glycol and triethylene glycol and 1-4000 μg/mL (glycerol. The limits of detection for the MSD detector were 2 μg/mL (propylene glycol and triethylene glycol and 4 μg/mL (glycerol with a linear range of 20-2000 μg/mL (propylene glycol and triethylene glycol and 40-4000 μg/mL (glycerol. Significant improvement in the sensitivity of the MSD can be achieved by employing selective ion monitoring (SIM detection mode. Although a high degree of correlation was observed between the results from FID and MSD analyses, marginal chromatographic resolution between glycerol and triethylene glycol limits the applicability of FID to samples containing low levels of both of these humectants. Utilizing MSD greatly improves the reliability of quantitative results because compensation for inadequate chromatographic resolution can be accomplished with mass selectivity in detection.

  13. 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.

  14. SO3 H-functionalized ionic liquids and their uses as dual solvent-catalysts for esterifications%SO3 H-功能化离子液体的合成及用于催化酯化反应的研究

    Institute of Scientific and Technical Information of China (English)

    杨雨林; 肖明; 王跃川

    2013-01-01

    A SO3H-functionalized ionic liquid catalyst,based on 4-dimethyl aminopyridine(DMAP),is synthesized by a two-step proceeding and its use as dual solvent-catalyst for esterification reaction of 1,4-butanediol with acetic acid is investigated.Reaction of DMAP with 1,3-propane sultone produces a monosubstituted zwitterionic compound ,whose tertiary amine nitrogen atom bearing the appended sulfonic acid group ,in high yields.The functional ionic liquid has good catalytic activity ,with the product yield reac-hing 88.1%,and selectivity approximately 100%at 40℃for 5 h.The synthesized esters could be separated by decantation ,and the ionic liquid could be reused after the removal of water.This stable ,eco-friendly ionic liquid may be an ideal catalyst for esterifica-tion of polyhydric alcohols.%  采用两步法制备了一种基于4-二甲氨基吡啶( DMAP)的SO3 H-功能化Br碬nsted酸性离子液体,并将其应用于催化1,4-丁二醇与乙酸的酯化反应。 DMAP与1,3-丙烷磺酸内酯(PS)反应生成单一的两性离子化合物,收率接近100%。该离子液体对1,4-丁二醇与乙酸的酯化反应催化活性较高,在温度为40℃时酯化率可达88.1%,选择性为100%,催化剂易与产物分离,且可以循环使用。

  15. The novel silicon-containing epoxy/PEPA phosphate flame retardant for transparent intumescent fire resistant coating

    Science.gov (United States)

    Shi, Yanchao; Wang, Guojian

    2016-11-01

    A series of novel silicon-containing epoxy/PEPA phosphate flame retardants (EPPSi) were synthesized by polyphosphoric acid (PPA), caged bicyclic phosphate 1-oxo-4-hydroxymethyl-2,6,7-trioxa-L-phosphabicyclo [2.2.2] octane (PEPA), and different ratios of silicon-containing epoxy 1,1,3,3-tetramethyl-1,3-bis(3-(oxiran-2-ylmethoxy)propyl)disiloxane (TMSEP) to 1,4-butanediol diglycidyl ether (BDE). The chemical structure of EPPSi was confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). Afterwards, the transparent intumescent fire resistant coatings were prepared by mixing EPPSi and melamine formaldehyde resin. The influence of silicon on the fire protection of coatings was intensively investigated by fire protection test, intumescence ratio, scanning electron microscope (SEM), compressive strength test, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and real-time FTIR. It was found that the fire resistant coatings obtained the best fire protection when the ratio of TMESP/BDE was 20/100, while excessive TMSEP made the fire protection of coatings deceased sharply. The intumescence ratio, compressive strength test and SEM result showed that a synergistic effect existed between phosphorus and silicon, which improved the foam structure and compressive strength of the char layer significantly. XPS result proved the out-migration effect of silicon. The high concentration silicon on surface played an important protecting role for the inner char residue and improved the fire protection of the coatings. TGA result demonstrated that silicon enhanced the thermo-oxidation resistance of coatings efficiently. Furthermore, real-time FTIR revealed the intumescent process of the fire resistant coatings according to the chemical structure changes of char residue.

  16. Influence of polyols on the formation of nanocrystalline nickel ferrite inside silica matrices

    Science.gov (United States)

    Stoia, Marcela; Barvinschi, Paul; Barbu-Tudoran, Lucian; Bunoiu, Mădălin

    2017-01-01

    We have synthesized nickel ferrite/silica nanocomposites, using a modified sol-gel method that combines the sol-gel processing with the thermal decomposition of metal-organic precursors, leading to a homogenous dispersion of ferrite nanoparticles within the silica matrix and a narrow size distribution. We used as starting materials tetraethyl orthosilicate (TEOS) as source of silica, Fe(III) and Ni(II) nitrates as sources of metal cations, and polyols as reducing agent (polyvinyl alcohol, 1,4-butanediol and their mixture). TG/DTA coupled technique evidenced the redox interaction between the polyol and the mixture of metal nitrates during the heating of the gel, with formation of nickel ferrite precursors in the pores of the silica-gels. FT-IR spectroscopy confirmed the formation of metal carboxylates inside the silica-gels and the interaction of the polyols with the Si-OH groups of the polysiloxane network. X-ray diffractometry evidenced that in case of nanocomposites obtained by using a single polyol, nickel ferrite forms as single crystalline phase inside the amorphous silica matrix, while in case of using a mixture of polyols the nickel oxide appears as a secondary phase. TEM microscopy and elemental mapping evidenced the fine nature of the obtained nickel ferrite nanoparticles that are homogenously dispersed within the silica matrix. The obtained nanocomposites exhibit magnetic behavior very close to superparamagnetism slightly depending on the presence and nature of the organic compounds used in synthesis; the magnetization reached at 5 kOe magnetic field was 7 emu/g for all composites.

  17. 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.

  18. Differences in Butadiene Adduct Formation between Rats and Mice Not Due to Selective Inhibition of CYP2E1 by Butadiene Metabolites

    Science.gov (United States)

    Pianalto, Kaila M.; Hartman, Jessica H.; Boysen, Gunnar; Miller, Grover P.

    2013-01-01

    CYP2E1 metabolizes 1,3-butadiene (BD) into genotoxic and possibly carcinogenic 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol (EB-diol). The dose response of DNA and protein adducts derived from BD metabolites increase linearly at low BD exposures and then saturate at higher exposures in rats, but not mice. It was hypothesized that differences in adduct formation between rodents reflect more efficient BD oxidation in mice than rats. Herein, we assessed whether BD-derived metabolites selectively inhibit rat but not mouse CYP2E1 activity using B6C3F1 mouse and Fisher 344 rat liver microsomes. Basal CYP2E1 activities toward 4-nitrophenol were similar between rodents. Through IC50 studies, EB was the strongest inhibitor (IC50 54 μM, mouse; 98 μM, rat), BD-diol considerably weaker (IC50 1200 μM, mouse; 1000 μM, rat), and DEB inhibition nonexistent (IC50 >25 mM). Kinetic studies showed that in both species EB and BD-diol inhibited 4-nitrophenol oxidation through two-site mechanisms in which inhibition constants reflected trends observed in IC50 studies. None of the reactive epoxide metabolites inactivated CYP2E1 irreversibly. Thus, there was no selective inhibition or inactivation of rat CYP2E1 by BD metabolites relative to mouse Cyp2e1, and it can be inferred that CYP2E1 activity toward BD between rodent species would similarly not be impacted by the presence of BD metabolites. Inhibition of CYP2E1 by BD metabolites is then not responsible for the reported species difference in BD metabolism, formation of BD-derived DNA and protein adducts, mutagenicity and tumorigenesis. PMID:24021170

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qi; Guo, Longhai [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Xiao, Weidong; Du, Dianxing [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2016-07-30

    Highlights: • A diol with side-chain trimethoxysilane (DEA-Si) was synthesized using 3-(methacryloxypropyl)trimethoxysilane (MAPTS) and diethanolamine (DEA). • The crosslinking structure could in situ formed within the WPU matrix through sol-gel process. • The Si tends to shift to the polymer-air interface due to the flexible long alkyl-ester side chain. • The incorporation of DEA-Si enhanced mechanical and surface hydrophobic properties of WPU films. - Abstract: 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.

  20. 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.

  1. 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)

  2. 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.

  3. 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。

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 聚(L-丙交酯-co-乙交酯)的制备及性能研究%Preparation and Properties of Poly(L-lactide-co-glycolide)

    Institute of Scientific and Technical Information of China (English)

    侯昭升; 孙斌; 曲文强; 董芳芳

    2014-01-01

    The poly(L-lactide-co-glycolide)(PLGA),in which the mass fraction ratio of glycolide and L-lactide was 6∶4, were prepared by bulk ring-opening polymerization at high temperature and high vacuum using stannous octoate as catalyst and 1 ,4-butanediol as initiator.The chemical structure of the polymer was characterized by IR and 1 H NMR,and the properties were researched by DSC,TGA,XRD and rheometer.The results show that PLGA has high thermal stability and it is amorphous.The melt of PLGA is shear-thinning fluid,it has lower storage modulus and higher loss modulus.%以辛酸亚锡为催化剂、1,4-丁二醇为引发剂,在高温、高真空条件下本体开环聚合制备了乙交酯与L-丙交酯质量比例为6∶4的聚(L-丙交酯-co-乙交酯)(PLGA)。通过IR、1 H NMR对聚合物的结构进行了表征,用DSC、TGA、XRD、流变仪等对聚合物的热性能、结晶性、流变性能进行了研究。研究结果表明PLGA具有较高的热稳定性,且是以非晶态存在的;其熔融流体为剪切变稀流体,储能模量较低,损耗模量较高。

  9. 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.

  10. 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.

  11. Hygroscopic and phase separation properties of ammonium sulfate/organic/water ternary solutions

    Science.gov (United States)

    Zawadowicz, M. A.; Proud, S. R.; Seppalainen, S. S.; Cziczo, D. J.

    2015-03-01

    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.

  12. Hygroscopic and phase separation properties of ammonium sulfate/organics/water ternary solutions

    Science.gov (United States)

    Zawadowicz, M. A.; Proud, S. R.; Seppalainen, S. S.; Cziczo, D. J.

    2015-08-01

    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. 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. 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 (Fourier transform infrared) 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. Some results of this study tend to be in agreement with previous microscopy experiments, but others, such as phase separation properties of 1,2,6-hexanetriol, do not agree with previous work. Because the particles studied in this experiment are of a smaller size than those used in microscopy studies, the discrepancies found could be a size-related effect.

  13. 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.

  14. 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。

  15. Synthesis of High Solid Carboxylate/Sulfonate Waterborne Polyurethane Dispersions%高固含量羧酸/磺酸盐型水性聚氨酯乳液的合成

    Institute of Scientific and Technical Information of China (English)

    刘新迁; 屠晓华; 徐欣欣; 郦聪; 吴建一

    2013-01-01

    With poly( 1,4 - butanediol adipate) ( PBA) as soft chain segment and isophorone diisocya-nate (IPDI) as hard chain segment, N - (2 - aminoethyl) - 2 - amino sodium ethyl sulfonate (AAS) and dimethylol propionic acid ( DMPA) as hydrophilic chain extender, a carboxylate/sulfonate waterborne polyurethane dispersions(PUDs) was synthesized. The polyurethane molecule containing sulfonic acid groups was confirmed by infrared spectroscopic analysis. The effect of the -NCO/-OH ratio, the content of DMPA and AAS was systematically investigated. The results showed that the emulsion and PUDs film with optimal properties could be obtained when the -NCO/-OH ratio was 1. 6 and the content of DMPA and AAS was 0. 8% and 3. 5% respectively.%以聚己二酸-1,4-丁二醇酯(PBA)和异佛尔酮二异氰酸酯(IPDI)为原料,以乙二胺基乙磺酸钠(AAS)和二羟甲基丙酸(DMPA)为亲水扩链剂制备了高固含量羧酸/磺酸盐型水性聚氨酯乳液.聚氨酯薄膜经红外光谱分析证实聚氨酯分子中含有磺酸基团.系统研究了-NCO/-OH物质的量比(R值)、DMPA含量和AAS含量对乳液及胶膜性能的影响.研究结果表明:当R值为1.6、DMPA含量为0.8%~1.0%、AAS含量为3.5%时,获得的乳液和胶膜的综合性能最佳.

  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. 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.

  18. 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.

  19. Head Space Solid Phase Micro-Extraction (HS - SPME of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636

    Directory of Open Access Journals (Sweden)

    Eunice Valduga

    2010-12-01

    Full Text Available The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636 using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME. Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm, temperature (25-60 ºC, extraction time (10-30 minutes, and sample volume (2-3 mL. The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD. The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v. In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm, temperature (23-33 ºC, pH (4.0-8.0, precursor concentration (0.02-0.1%, mannitol (0-6%, and asparagine concentration (0-0.2% was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

  20. 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.

  1. Preparation and catalytic application of tungstovanadophosphoric heteropolyacid with Keggin structure for the synthesis of tetrahydrofuran%磷钨钒杂多酸的制备、表征及催化合成四氢呋喃

    Institute of Scientific and Technical Information of China (English)

    严平; 徐常龙; 谢宝华; 陶春元; 占昌朝

    2012-01-01

    Series of tungstovanadophosphoric heteropolyacid with Keggin structure were prepared by hydrothermal synthesis and characterized by FT-IR,UV-Vis. The results indicated that the heteropolyacids had Keggin structure. The catalytic performance in synthesis of tetrahydrofuran from 1,4-butane-diol was investigated. The main effects of the reaction were optimized with orthogonal experiments. The results showed that under the optimal condition,i. e. the vanadium atom number was three, the mass ratio of the catalyst to total reactant was 3. 93% ,the reaction temperature was 180 - 190 ℃ , the reaction time was SO min, the yield of tetrahydrofuran could reach 85. 4% . The catalyst could be reused for 3 times and the yield was still above 82. 3% . This method provided a green, safe and operation simple process to produce tetrahydrofuran.%通过水热法制备了系列Keggin结构磷钨钒杂多酸催化剂,并通过FT-IR、UV-Vis对催化剂结构进行表征.以1,4-丁二醇脱水合成四氢呋喃为探针反应,考察催化剂催化性能.通过正交实验确定了反应的优化条件:钒原子取代个数为3,催化剂质量分数为3.93%(相对1,4-丁二醇质量),反应温度180 ~ 190℃,反应时间50 min,四氢呋喃平均收率达85.4%.催化剂重复使用3次,收率仍可达82.3%.本工艺具有绿色、安全、操作简单等优点.

  2. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  3. Surface and buried interfacial structures of epoxy resins used as underfills studied by sum frequency generation vibrational spectroscopy.

    Science.gov (United States)

    Vázquez, Anne V; Holden, Brad; Kristalyn, Cornelius; Fuller, Mike; Wilkerson, Brett; Chen, Zhan

    2011-05-01

    Flip chip technology has greatly improved the performance of semiconductor devices, but relies heavily on the performance of epoxy underfill adhesives. Because epoxy underfills are cured in situ in flip chip semiconductor devices, understanding their surface and interfacial structures is critical for understanding their adhesion to various substrates. Here, sum frequency generation (SFG) vibrational spectroscopy was used to study surface and buried interfacial structures of two model epoxy resins used as underfills in flip chip devices, bisphenol A digylcidyl ether (BADGE) and 1,4-butanediol diglycidyl ether (BDDGE). The surface structures of these epoxies were compared before and after cure, and the orientations of their surface functional groups were deduced to understand how surface structural changes during cure may affect adhesion properties. Further, the effect of moisture exposure, a known cause of adhesion failure, on surface structures was studied. It was found that the BADGE surface significantly restructured upon moisture exposure while the BDDGE surface did not, showing that BADGE adhesives may be more prone to moisture-induced delamination. Lastly, although surface structure can give some insight into adhesion, buried interfacial structures more directly correspond to adhesion properties of polymers. SFG was used to study buried interfaces between deuterated polystyrene (d-PS) and the epoxies before and after moisture exposure. It was shown that moisture exposure acted to disorder the buried interfaces, most likely due to swelling. These results correlated with lap shear adhesion testing showing a decrease in adhesion strength after moisture exposure. The presented work showed that surface and interfacial structures can be correlated to adhesive strength and may be helpful in understanding and designing optimized epoxy underfill adhesives.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. A new bi-layered scaffold for osteochondral tissue regeneration: In vitro and in vivo preclinical investigations.

    Science.gov (United States)

    Sartori, M; Pagani, S; Ferrari, A; Costa, V; Carina, V; Figallo, E; Maltarello, M C; Martini, L; Fini, M; Giavaresi, G

    2017-01-01

    Current treatments for acute or degenerative chondral and osteochondral lesions are in need of improvement, as these types of injuries lead to disability and worsen the quality of life in a high percentage of patients. The aim of this study was to develop a new bi-layered scaffold for osteochondral tissue regeneration through a "biomimetic" and "bioinspired" approach. For chondral regeneration, the scaffold was realized with an organic compound (type I collagen), while for the regeneration of the subchondral layer, bioactive magnesium-doped hydroxyapatite (Mg/HA) crystals were co-precipitated with the organic component of the scaffold. The entire scaffold structure was stabilized with a cross-linking agent, highly reactive bis-epoxyde (1,4-butanediol diglycidyl ether - BDDGE 1wt%). The developed scaffold was then characterized for its physico-chemical characteristics. Its structure and adhesion strength between the integrated layers were investigated. At the same time, in vitro cell culture studies were carried out to examine the ability of chondral and bone scaffold layers to separately support adhesion, proliferation and differentiation of human mesenchymal stem cells (hMSCs) into chondrocytes and osteoblasts, respectively. Moreover, an in vivo study with nude mice, transplanted with osteochondral scaffolds plain or engineered with undifferentiated hMSCs, was also set up with 4 and 8-week time points. The results showed that chondral and bone scaffold layers represented biocompatible scaffolds able to sustain hMSCs attachment and proliferation. Moreover, the association of scaffold stimuli and differentiation medium, induced hMSCs chondrogenic and osteogenic differentiation and deposition of extracellular matrix (ECM). The ectopic implantation of the engineered osteochondral scaffolds indicated that hMSCs were able to colonize the osteochondral scaffold in depth. The scaffold appeared permissive to tissue growth and penetration, ensuring the diffusion of

  13. DNA damage induced by three major metabolites of 1,3-butadiene in human hepatocyte L02 cells.

    Science.gov (United States)

    Zhang, Pan-Pan; Wen, Ying; An, Jing; Yu, Ying-Xin; Wu, Ming-Hong; Zhang, Xin-Yu

    2012-09-18

    1,3-Butadiene (BD) is a carcinogenic air pollutant. Its bioactivation produces four major metabolites, i.e., 3,4-epoxy-1-butene (EB), 3,4-epoxy-1,2-butanediol (EBD), 1,2,3,4-diepoxybutane (DEB), and 3-butene-1,2-diol (BDD). Studies have been mostly focused on DEB due to its strong mutagenicity/carcinogenicity. In contrast, studies of genotoxicity of EB, EBD, and BDD have been limited. In particular, genotoxicity of EBD and BDD using strand breaks as the endpoint has not been investigated. To obtain a more complete understanding of BD toxicity, in the present study, we used comet assay to investigate DNA damage induced by EB, EBD, and BDD in human hepatocyte L02 cells, with the aim to determine their relative potencies, the types of DNA damage, and the possible pathway to form strand breaks. Using alkaline comet assay (pH>13), it was observed that EB and EBD caused similar concentration-dependent increases in DNA migration from 50 to 1000μM. However, BDD induced a statistically significant increase only at 1000μM, and the increase itself was very small. EBD was as potent as EB at lower concentrations (≤200μM), and was slightly less potent than EB at higher concentrations. The results indicated that these metabolites could generate strand breaks in cells with the rank order of the potencies being EB>≈EBD≫BDD. All three compounds failed to cause statistically significant increases in DNA migration in pre-lysed cells, suggesting that they did not produce strand breaks through chemical pathways under our experimental conditions. By using comet assays at pH 11.9 and pH 9, it was demonstrated that EB and EBD generated both single-strand breaks (SSB) and alkali-labile sites, but BDD produced only SSB. To our knowledge, this is the first report to investigate EBD- and BDD-induced strand breaks in cells. The results implied that EBD could play an important role in toxicity of BD.

  14. Genome-Guided Insights into the Plant Growth Promotion Capabilities of the Physiologically Versatile Bacillus aryabhattai Strain AB211

    Science.gov (United States)

    Bhattacharyya, Chandrima; Bakshi, Utpal; Mallick, Ivy; Mukherji, Shayantan; Bera, Biswajit; Ghosh, Abhrajyoti

    2017-01-01

    Bacillus aryabhattai AB211 is a plant growth promoting, Gram-positive firmicute, isolated from the rhizosphere of tea (Camellia sinensis), one of the oldest perennial crops and a major non-alcoholic beverage widely consumed all over the world. The whole genome of B. aryabhattai AB211 was sequenced, annotated and evaluated with special focus on genomic elements related to plant microbe interaction. It’s genome sequence reveals the presence of a 5,403,026 bp chromosome. A total of 5226 putative protein-coding sequences, 16 rRNA, 120 tRNA, 8 ncRNAs, 58 non-protein coding genes, and 11 prophage regions were identified. Genome sequence comparisons between strain AB211 and other related environmental strains of B. aryabhattai, identified about 3558 genes conserved among all B. aryabhattai genomes analyzed. Most of the common genes involved in plant growth promotion activities were found to be present within core genes of all the genomes used for comparison, illustrating possible common plant growth promoting traits shared among all the strains of B. aryabhattai. Besides the core genes, some genes were exclusively identified in the genome of strain AB211. Functional annotation of the genes predicted in the strain AB211 revealed the presence of genes responsible for mineral phosphate solubilization, siderophores, acetoin, butanediol, exopolysaccharides, flagella biosynthesis, surface attachment/biofilm formation, and indole acetic acid production, most of which were experimentally verified in the present study. Genome analysis and experimental evidence suggested that AB211 has robust central carbohydrate metabolism implying that this bacterium can efficiently utilize the root exudates and other organic materials as an energy source. Genes for the production of peroxidases, catalases, and superoxide dismutases, that confer resistance to oxidative stresses in plants were identified in AB211 genome. Besides these, genes for heat shock tolerance, cold shock tolerance

  15. 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.

  16. Preparation of Anion-exchange Polymer-based Monolithic Column and Its Application in Ion Chromatography%阴离子交换聚合物整体柱的制备及其在离子色谱中的应用

    Institute of Scientific and Technical Information of China (English)

    李晶; 周琰春; 张嘉捷; 朱岩

    2012-01-01

    An anion-exchange monolithic column was prepared by a polymerization inside a stainless steel tube( 150 mm x 4. 6 i. d. mm) , taking glycidyl methacrylate( GMA) as functional monomer, ethylene dimethacrylate ( EDMA) as cross-linking agent and in the presence of 1, 4-butanediol, 1 -propanol and water as the porogen solvents and azobisisobutyronitrile ( AIBN) as a suitable initiator. Introduction of anion-exchange sites were achieved by reacting with tirmethylamine. Under the optimized reaction conditions and the modified conditions, the chromatographic characteristics of the prepared anion-exchange columns were further studied, and the separation of 5 common anions ( such as, acetate, bromate, nitrite, bromide, nitrate) on the prepared anion-exchange column was investigated. The prepared column exhibits more advantages such as simple preparation and low cost, and could be coupled with a commercial ion chromatography system directly, which will be favorable for more applications and investigations.%以偶氮二异丁腈( AIBN)为自由基引发剂,将甲基丙烯酸缩水甘油酯(GMA)单体和亚乙基二甲基丙烯酸酯(EDMA)交联剂通过原位聚合的方法,在不锈钢管柱(150 mm ×4.6 i.d.mm)中合成为具有一定机械性能和一定孔径结构的聚合物整体色谱柱;利用三甲胺动态修饰反应将整体柱改性为具有阴离子交换功能的整体型离子色谱分离柱.实验优化了制备条件和改性修饰条件,考察了相关离子交换容量、流体动力学参数和色谱性能等.采用直接紫外检测的方法,在205 nm检测波长下,常规阴离子乙酸根、溴酸根、亚硝酸根、溴离子、硝酸根均能得到较好的分离检测.结果表明,该阴离子交换整体色谱柱制备方法简便,成本较低,可以方便地与常规色谱系统进行联用,具有一定分析实用价值和较大的开发前景.

  17. 阳离子交换毛细管整体柱的制备及其在毛细管离子色谱中的应用%Preparation and Application of Cation-exchange Capillary Monolithic Column in Capillary Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    李晶; 朱岩

    2013-01-01

    Polymer-based cation exchange capillary monolithic column was prepared for capillary ion chromatography (CIC) by radical polymerization in a 320-μm-i. d. fused-silica capillary tube, taking glycidyl methacrylate ( GMA ) as the functional monomer, ethylene dimethacrylate ( EDMA) as the cross-linking agent and in the presence of 1 ,4-butanediol, 1-propanol and water as the porogen solvents and azobisisobutyronitrile (AIBN) as a suitable initiator. Introduction of cation exchange sites was achieved by reacting with Na2SO3. Coupled with the prepared cation exchange capillary monolithic column, a capillary ion chromatography system was constructed with a pump (in μL/min level) , a capillary detection cell and a UV detector, on which more chromatographic characteristics were further studied. With the CIC system, 9 common univalent and divalent cations (Li+ , Na+ , NH4+ , K+ , Cs+ , Mg2+, Ca2+ , Sr2+, Ba2+) were successfully separated and determined by flow rate gradient. Another interesting separation of cations and melamine was also tested on the prepared column.%以甲基丙烯酸缩水甘油酯(GMA)为功能单体,亚乙基二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为自由基引发剂,在三元致孔剂(正丙醇,1,4-丁二醇,水)的存在下,在320μm内径的弹性石英毛细管柱内制备得到带有环氧功能基团的聚合物整体柱基质;利用Na2SO3对其改性,制备得到磺酸基型阳离子交换毛细管整体柱.采用微流泵、毛细管检测池和紫外检测器构建了毛细管离子色谱系统,并对所制备的整体柱的流体力学参数、色谱性能参数进行评价;采用流速梯度洗脱的方式实现9种常见阳离子(Li+,Na+,NH4+,K+,Cs+,Mg2+,Ca2+,Sr2+,Ba2+)的分离分析;此色谱系统还可应用于牛奶中阳离子和三聚氰胺的分离检测.

  18. Synthesis of poly ( butylene succinate)%聚丁二酸丁二醇酯的合成

    Institute of Scientific and Technical Information of China (English)

    郑文俊; 黄关葆

    2011-01-01

    A poly(butylene succinate) (PBS) with higher relative molecular weight was synthesized by direct esterification-polycondensation of succinic acid(SA) and 1,4-butanediol( BD), and it was the first time to investigate the side reaction of esterification in PBS by using refractometric analysis. The results showed that the esterification rate was significantly affected by SA/BD ratio, temperature and catalysts. The side reaction increased with the increase of the amount of BD and rising of the temperature. The viscosity- average molecular weight of the synthesized PBS was from 5. 7 x 104 g/mol to 8. 0 x 104 g/mol, and the highest molecular weight PBS was obtained when the esterification temperature was 150 ℃ , SA/ BD ratio was 1: 1. 2, the amount of titanium catalyst was 0. 1% of SA( mole ratio) , and the temperature of polycondensation was 220 ℃.%通过直接酯化-缩聚法,以丁二酸、丁二醇为原料,合成了相对分子质量较高的聚丁二酸丁二醇酯(PBS),并首次采用折光率法研究了PBS酯化反应中的副反应.结果表明:酯化反应中,酸醇比、反应温度及催化剂对酯化率的影响较大;随着丁二醇加入量的增加,酯化反应中的副反应增强,随着反应温度的升高也增强;缩聚反应所合成PBS的黏均摩尔质量在5.7 ×104~8.0×104 g/mol之间,且在酯化反应温度为150℃,酸醇比为1∶1.2,采用钛系催化剂,其用量为所加入丁二酸的0.1%(物质的量比),缩聚反应温度为220℃时,所得产物分子质量最高.

  19. 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.

  20. Cloning and knockout of formate hydrogen lyase and H{sub 2}-uptake hydrogenase genes in Enterobacter aerogenes for enhanced hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hongxin; Ma, Kun; Lu, Yuan; Zhang, Chong; Wang, Liyan; Xing, Xin-Hui [Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Tsinghua Yuan, Beijing 100084 (China)

    2009-01-15

    A 5431-bp DNA fragment partially encoding the formate hydrogen lyase (FHL) gene cluster hycABCDE was isolated and identified from Enterobacter aerogenes IAM1183 chromosomal DNA. All the five putative gene products showed a high degree of homology to the reported bacterial FHL proteins. The gene hycA, encoding the FHL repressor protein, and hybO, encoding the small subunit of the uptake hydrogenase, were targeted for genetic knockout for improving the hydrogen production. The pYM-Red recombination system was adopted to form insertional mutations in the E. aerogenes genome, thereby creating mutant strains of IAM1183-A ({delta} hycA), IAM1183-O ({delta} hybO), and IAM1183-AO ({delta} hycA/ {delta} hybO double knockout). The hydrogen production experiments with these mutants showed that the maximum specific hydrogen productivities of IAM1183-A, IAM1183-O, and IAM1183-AO were 2879.466 {+-} 38.59, 2747.203 {+-} 13.25 and 3372.019 {+-} 4.39 (ml h{sup -1} g{sup -1}dry cell weight), respectively, higher than that of the wild strain (2321.861 {+-} 15.34 ml h{sup -1} g{sup -1}dry cell weight). The total H{sub 2} yields by the three mutants IAM1183-A, IAM1183-O and IAM1183-AO were 0.73, 0.78, and 0.83 mol-H{sub 2}/mol glucose, respectively, while the wild-type IAM1183 was only 0.65 mol-H{sub 2}/mol glucose. The metabolites of the mutants including acetate, ethanol, 2,3-butanediol and succinate were all increased compared with that of the wild type, implying the changed metabolic flux by the mutation. In the fermentor cultivation with IAM1183 {delta} hycA/ {delta} hybO, the total hydrogen volume after 16 h cultivation reached 4.4 L, while that for the wild type was only 2.9 L. (author)

  1. Exogenous ketone supplements reduce anxiety-related behavior in Sprague-Dawley and Wistar Albino Glaxo/Rijswijk rats

    Directory of Open Access Journals (Sweden)

    Csilla Ari

    2016-12-01

    Full Text Available Nutritional ketosis has been proven effective for seizure disorders and other neurological disorders. The focus of this study was to determine the effects of ketone supplementation on anxiety-related behavior in Sprague-Dawley (SPD and Wistar Albino Glaxo/Rijswijk (WAG/Rij rats. We tested exogenous ketone supplements added to food and fed chronically for 83 days in SPD rats and administered sub-chronically for 7 days in both rat models by daily intragastric gavage bolus followed by assessment of anxiety measures on elevated plus maze (EPM. The groups included standard diet (SD or SD + ketone supplementation. Low-dose ketone ester (LKE (1,3-butanediol-acetoacetate diester, ~10 g/kg/day, LKE, high dose ketone ester (HKE (~25 g/kg/day, HKE, beta-hydroxybutyrate-mineral salt (βHB-S (~25 g/kg/day, KS, and βHB-S + medium chain triglyceride (MCT (~25 g/kg/day, KSMCT were used as ketone supplementation for chronic administration. To extend our results, exogenous ketone supplements were also tested sub-chronically on SPD rats (KE, KS and KSMCT; 5 g/kg/day and on WAG/Rij rats (KE, KS and KSMCT; 2.5 g/kg/day. At the end of treatments behavioral data collection was conducted manually by a blinded observer and with a video-tracking system, after which blood βHB and glucose levels were measured. Ketone supplementation reduced anxiety on EPM as measured by less entries to closed arms (sub-chronic KE and KS: SPD rats and KSMCT: WAG/Rij rats, more time spent in open arms (sub-chronic KE: SPD and KSMCT: WAG/Rij rats; chronic KSMCT: SPD rats, more distance travelled in open arms (chronic KS and KSMCT: SPD rats, and by delayed latency to entrance to closed arms (chronic KSMCT: SPD rats, when compared to control. Our data indicates that chronic and sub-chronic ketone supplementation not only elevated blood βHB levels in both animal models, but reduced anxiety-related behavior. We conclude that ketone supplementation may represent a promising anxiolytic strategy

  2. 有机硅改性水性聚氨酯增深剂的合成及应用%Synthesis and application of silicone modified waterborne polyurethane darkening agent

    Institute of Scientific and Technical Information of China (English)

    李喜龙; 周向东; 张军军; 张路路

    2013-01-01

    Taking isophorone diisocyanate (IPDI) and polypropylene glycol (PPG) as raw material, polyure-thane prepolymer was synthesized under the catalysis of dibutyltin dilaurate (DBTDL). Cationic type of organic silicon modified waterbome polyurethane emulsion was prepared through the modification of the prepolymer with 3-aminopropyltriethoxysilane (KH-550) and through the chain extension with 1,4-butanediol (BDO) and triethanolamine (TEA). The effects of R value [n(-NCO)/n(-OH)], w(KH-550), and w(TEA) on the performance of emulsion were discussed. The structure and properties of the darkening agent were characterized by FT-IR, 1H-NMR and Zeta potential. The properties of the cotton fabrics and silk fabrics finished with the darkening agent were tested. The results showed that the deepening ratio of the black cotton fabrics and silk fabrics were 19.73% and 17.49%, respectively. The dry and wet rubbing fastness were both increased over half level. And the darkening effect of the finished fabrics had good washing durability.%以异佛尔酮二异氰酸酯(IPDI)和聚丙二醇(PPG,Mn =600)为原料,在催化剂二月桂酸二丁基锡(DBTDL)作用下合成聚氨酯预聚体,经3-氨丙基三乙氧基硅烷(KH-550)改性后,通过1,4-丁二醇(BDO)和三乙醇胺(TEA)扩链,合成了阳离子型有机硅改性水性聚氨酯乳液.讨论了R值[n(-NCO)/n(-OH)]、w(KH-550)以及w(TEA)对乳液性能的影响.利用红外光谱(FT-IR)、核磁共振氢谱(H-NMR)和Zeta电位表征了增深剂的结构及其性能,并测试了全棉织物和真丝织物经增深剂整理后的性能.结果表明:增深后的黑色全棉织物的增深百分率为19.73%,黑色真丝织物的增深百分率为17.49%,干、湿摩擦牢度提高0.5级以上,整理后织物的耐洗性能比较好.

  3. Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lei; Huang, Xiaojia, E-mail: hxj@xmu.edu.cn

    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

  4. 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

  5. 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

  6. 邻苯二甲酸酐与环氧氯丙烷反应合成聚酯树脂%Synthesis of Polyester Resin from Phthalic Anhydride and Epichlorohydrin

    Institute of Scientific and Technical Information of China (English)

    晋云全; 申屠宝卿; 翁志学

    2011-01-01

    以四乙基溴化胺为催化剂,1,4-丁二醇为起始剂,邻苯二甲酸酐和环氧氯丙烷为原料合成聚酯树脂,采用傅立叶红外光谱(FT-IR)和核磁共振(1H-NMR)对产物的结构进行表征,并考察了催化剂用量和反应温度对合成聚酯树脂的影响.结果表明,合成聚酯树脂的端基为羟基,且随着温度升高和催化剂用量增加,反应速率增加,合适的反应条件为温度100℃,邻苯二甲酸酐16.28g,环氧氯丙烷10.18g,1,4-丁二醇0.36g,四乙基溴化铵0.21g,溶剂N,N-二甲基甲酰胺4 mL.聚酯树脂的合成为一级反应,其表观活化能为91 kJ/mol,指前因子为4.99 min(-1).%The polyester resin was synthesized from phthalic anhydride(PA) and epichlorohydrin(ECH) over catalyst tetraethylammonium bromide(TEAB) using l,4-butanediol(BDO) as initiator and was characterized by means of Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H-NMR). The effects of reaction temperature and catalyst dosage on synthesis of polyester resin were investigated. The results showed that the product was polyester resin with hydroxyl end group. The reaction rate increased with the increase of temperature or catalyst dosage. The appropriate reaction conditions were temperature 100 ℃. PA 16.28 g. And ECH 10.18 g, BDO 0.36 g, TEAB 0.21 g. Solvent N,N-dimethy!formamide 4 mL. The synthesis of polyester resin was the first-order reaction and the apparent activation energy was 91 kJ/mol, the pre-exponential factor was 4.99 min-1.

  7. Lipase-catalyzed synthesis of aliphatic polyesters via copolymerization of lactone, dialkyl diester, and diol.

    Science.gov (United States)

    Jiang, Zhaozhong

    2008-11-01

    Candida antarctica lipase (CALB) has been successfully used as catalyst for copolymerization of dialkyl diester with diol and lactone to form aliphatic polyesters. The polymerization reactions were performed using a two stage process: first stage oligomerization under low vacuum followed by second stage polymerization under high vacuum. Use of the two-stage process is required to obtain products with high molecular weights at high yields for the following reasons: (i) the first stage reaction ensures that the monomer loss via evaporation is minimized to maintain 1:1 diester to diol stoichiometric ratio, and the monomers are converted to nonvolatile oligomers; (ii) use of high vacuum during the second stage accelerates equilibrium transesterification reactions to transform the oligomers to high molecular weight polymers. Thus, terpolymers of omega-pentadecalactone (PDL), diethyl succinate (DES), and 1,4-butanediol (BD) with a M w of whole product (nonfractionated) up to 77000 and M w/ M n between 1.7 and 4.0 were synthesized in high yields (e.g., 95% isolated yield). A desirable reaction temperature for the copolymerizations was found to be around 95 degrees C. At 1:1:1 PDL/DES/BD monomer molar ratio, the resultant terpolymers contained equal moles of PDL, succinate, and butylene repeat units in the polymer chains. (1)H and (13)C NMR analyses were used to determine the polyester microstructures. The synthesized PDL-DES-BD terpolymers possessed near random structures with all possible combinations of PDL, succinate, and butylene units via ester linkages in the polymer backbone. Furthermore, thermal stability and crystallinity of a pure PDL-DES-BD terpolymer with 1:1:1 PDL to succinate to butylene unit ratio and M w of 85400 were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The copolyester was found to be a semicrystalline material with a T g of -34 degrees C and a T m of 64 degrees C, which degrades in a single weight loss

  8. 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。

  9. 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.

  10. Syntheses and physical characterization of new aliphatic triblock poly(L-lactide-b-butylene succinate-b-L-lactide)s bearing soft and hard biodegradable building blocks.

    Science.gov (United States)

    Ba, Chaoyi; Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Cao, Amin

    2003-01-01

    This study presents chemical syntheses and physical characterization of a new aliphatic poly(L-lactide-b-butylene succinate-b-L-lactide) triblock copolyester with soft and hard biodegradable building blocks. First, poly(butylene succinate) (PBS) prepolymers terminated with hydroxyl functional groups were synthesized through melt polycondensation from succinic acid and 1,4-butanediol. Further, a series of new PLLA-b-PBS-b-PLLA triblock copolyesters bearing various average PLLA block lengths were prepared via ring opening polymerization of L-lactide with the synthesized hydroxyl capped PBS prepolymer (Mn = 4.9 KDa) and stannous octanoate as the macroinitiator and catalyst, respectively. By means of GPC, NMR, FTIR, DSC, TGA, and wide-angle X-ray diffractometer (WAXD), the macromolecular structures and physical properties were intensively studied for these synthesized PBS prepolymer and PLLA-b-PBS-b-PLLA triblock copolyesters. 13C NMR and GPC experimental results confirmed the formation of sequential block structures without any detectable transesterification under the present experimental conditions, and the molecular weights of triblock copolyesters could be readily regulated by adjusting the feeding molar ratio of L-lactide monomer to the PBS macroinitiator. DSC measurements showed all single glass transitions, and their glass transition temperatures were found to be between those of PLLA and PBS, depending on the lengths of PLLA blocks. It was noteworthy that the segmental flexibilities of the hard PLLA blocks were found to be remarkably enhanced by the more flexible PBS block partner, and the PBS and PLLA building blocks were well mixed in the amorphous regions. Results of TGA analyses indicated that thermal degradation and stabilities of the PLLA blocks strongly depended on the average PLLA block lengths of triblock copolyesters. In addition, FTIR and WAXD results showed the coexistence of the assembled PLLA and PBS crystal structures when the average PLLA block

  11. 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

  12. The novel silicon-containing epoxy/PEPA phosphate flame retardant for transparent intumescent fire resistant coating

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yanchao [School of Materials Science and Engineering, Tongji University, 4800 Cao' an Road, Shanghai 201804 (China); Wang, Guojian, E-mail: wanggj@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, 4800 Cao' an Road, Shanghai 201804 (China); Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, 4800 Cao' an Road, Shanghai 201804 (China)

    2016-11-01

    Highlights: • The novel halogen-free flame retardant containing silicon and caged bicyclic phosphate was synthesized. • A novel transparent intumescent fire resistant coating was developed by the P-Si synergistic flame retardant and melamine formaldehyde resin. • Excellent fire protection of the transparent intumescent fire resistant coating. • The P-Si synergistic flame retardant could improve the thermo-oxidation resistance of transparent fire resistant coating. - Abstract: A series of novel silicon-containing epoxy/PEPA phosphate flame retardants (EPPSi) were synthesized by polyphosphoric acid (PPA), caged bicyclic phosphate 1-oxo-4-hydroxymethyl-2,6,7-trioxa-L-phosphabicyclo [2.2.2] octane (PEPA), and different ratios of silicon-containing epoxy 1,1,3,3-tetramethyl-1,3-bis(3-(oxiran-2-ylmethoxy)propyl)disiloxane (TMSEP) to 1,4-butanediol diglycidyl ether (BDE). The chemical structure of EPPSi was confirmed by Fourier transform infrared spectroscopy (FTIR) and {sup 1}H nuclear magnetic resonance spectroscopy ({sup 1}H NMR). Afterwards, the transparent intumescent fire resistant coatings were prepared by mixing EPPSi and melamine formaldehyde resin. The influence of silicon on the fire protection of coatings was intensively investigated by fire protection test, intumescence ratio, scanning electron microscope (SEM), compressive strength test, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and real-time FTIR. It was found that the fire resistant coatings obtained the best fire protection when the ratio of TMESP/BDE was 20/100, while excessive TMSEP made the fire protection of coatings deceased sharply. The intumescence ratio, compressive strength test and SEM result showed that a synergistic effect existed between phosphorus and silicon, which improved the foam structure and compressive strength of the char layer significantly. XPS result proved the out-migration effect of silicon. The high concentration silicon on surface played

  13. Structurally characterized luminescent lanthanide zinc carboxylate precursors for Ln-Zn-O nanomaterials.

    Science.gov (United States)

    Boyle, Timothy J; Raymond, Rebecca; Boye, Daniel M; Ottley, Leigh Anna M; Lu, Ping

    2010-09-14

    A novel family of lanthanide zinc carboxylate compounds was synthesized, characterized (structural determination and luminescent behavior), and investigated for utility as single-source precursors to Ln-Zn-O nanoparticles. Carboxylic acids [H-ORc = H-OPc (H-O(2)CCH(CH(3))(2), H-OBc (H-O(2)CC(CH(3))(3), H-ONc (H-O(2)CCH(2)C(CH(3))(3))] were individually reacted with diethyl zinc (ZnEt(2)) to yield a set of previously unidentified zinc carboxylates: (i) [Zn(mu-ORc)(3)Zn(mu-ORc)](n) [ORc = OPc (1), ONc (2)], (ii) [(py)Zn](2)(mu-ORc)(4) [ORc = OBc (3), ONc (4), and py = pyridine], or (iii) Zn(ORc)(2)(solv)(2) [ORc/solv = OPc/py (5), O(c)Nc/H(2)O (6) (O(c)Rc = chelating)]. Introduction of lanthanide cation [Ln[N(SiMe(3))(2)](3), ZnEt(2), and HOBc in py] yielded the mixed cationic species structurally characterized as: (i) (O(c)Bc)Ln[(mu-OBc)(3)Zn(py)](2) [Ln = Pr (7), Nd (8), Sm (9)] or (ii) (py)(2)Zn(mu-OBc)(3)Ln(O(c)Bc)(2)(py) [Ln = Tb (10), Dy (11), Er (12), Y (13), Yb (14)]. Exploration of alternative starting materials [Ln(NO(3))(3).nH(2)O, Zn(O(2)CCH(3))(2), HOBc in py] led to the isolation of (NO(3)(c))Ln[(mu-OBc)(3)Zn(py)](2) [Ln = La (15), Ce (16), Pr (17), Nd (18), Sm (19), Eu (20), Gd (21), Tb (22) Dy (23), and Er (24); NO(3)(c) = chelating]. The UV-vis spectra of 7-24 revealed standard absorption spectra for the Ln cations. Representative compounds were used to generate nanoparticles from an established 1,4-butanediol-based solution precipitation route. The nanoproducts isolated adopted either a mixed zincite/lanthanum oxide (18n or 22n) or pure zincite (8n or 10n) phase dependent on NO(3) or OBc moiety. Fluorescence was not observed for any of these nanomaterials possibly due to phase separation, low crystallinity, surface traps, and/or quenching based on elevated Ln cation content.

  14. Effect of phosphate on 1,3-propanediol metabolism by marineKlebsiella pneumonia HSL4%磷酸根对海洋克雷伯氏菌合成1,3-丙二醇代谢的影响

    Institute of Scientific and Technical Information of China (English)

    李莉莉; 周胜; 高品; 郭传宇; 俞也频; 尼松伟; 李鹏飞; 秦启伟

    2015-01-01

    Klebsiella pneumoniae HSL4 is an excellent strain for the fermentation of 1,3-propanediol(1,3-PDO), which was isolated from coastal mangrove sediment environment. Many nutrient factors are involved in the culture medium ofK. pneumoniae HSL4. Among them, phosphate is one of the main factors, which have a significant impact on the fermentation. The effects of the low concentration of phosphate (LP: 1.6×10?4mol·L?1 PO43?) and the high concentration phosphate (HP: 5.0×10?3mol·L?1 PO43?) on cell growth, 1,3-PDO and by-product (acetic succinic acid, lactic acid, acid, 2,3-butanediol, and ethanol) production were studied. The impacts of phosphate on the metabolism ofK. pneumoniae HSL4 were characterized by metabolic flux analysis. The results showed that the final concentration of 1,3-PDO was 75g·L?1 under both LP and HP in the culture medium. Significantly, the 1,3-PDO conversion was higher, but the substrate glycerol consumption and by-products (except for 2,3-butanediol) accumulation were less under LP condition compared to HP condition. The productions of acetic acid and ethanol were higher under HP condition. The accumulations of acetic acid and ethanol will change the environment of fermentation and increase the difficulty of product separation in the downstream. Metabolic flux distributions in four fermentation periods (adjustmental phase, log phase, stationary phase, and decline phase) were analyzed. This study will help researchers to choose reasonable phosphate concentration in the culture broth and provide information for process control and metabolic regulation in 1,3-PDO fermentation byK. pneumoniae HSL4.%海洋克雷伯氏菌Klebsiella pneumoniaeHSL4是一株分离于海洋沉积物环境的用于发酵生产1,3-丙二醇(1,3-propanediol, 1,3-PDO)的优良菌株.K. pneumoniaeHSL4发酵生产1,3-PDO的培养基包含多种营养因子,其中磷酸根对发酵过程影响较大.利用5L发酵罐进行补料发酵实验,分别考察培养基中低磷(1.6

  15. 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

  16. 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

  17. 川维厂天然气化工和煤化工协同发展工艺流程研究%A study on synergetic development of natural gas-based and coal-based chemicals in SVW

    Institute of Scientific and Technical Information of China (English)

    朱成文

    2013-01-01

      In order to solve the problems in Sichuan Vinylon Works (SVW), such as the simple feedstock and product structure, low utilization efficiency of partial methanol equipment, methyl acetate and natural gas, an optimization scheme for acetic anhydride and 1,4-butanediol (BDO) integrated project was presented by utilizing the advantages of natural gas-based and coal-based syngas and incorporating the existing process. Additionally, analysis and selection were carried out in terms of the major process scheme through which the synergetic development of natural gas-based and coal-based chemicals can be achieved. The newly increased natural gas would be only used to produce acetylene through which the high valued-added BDO and its downstream products could be produced. The coal-based syngas would be used as the feedstock of methanol, acetic anhydride (co-producing acetic acid), ethylene glycol, ethanol, etc. This scheme could increase the diversification of SVW’s feedstock configuration, the high value-added products, and the utilization efficiency of natural gas, improve the product structure, revitalize the idle assets and reduce PVA production cost. Furthermore, it would create good conditions for developing high value-added industrial chain and achieve a significant economic, social and strategic benefit.%  针对川维厂原材料结构和产品结构单一、部分甲醇设备闲置、醋酸甲酯和天然气利用率不高等现状,利用煤和天然气制合成气各自优势,结合现有流程,提出醋酐和BDO一体化项目优化方案,并对主要工艺技术方案进行分析选择,实现天然气化工和煤化工协同发展,新增天然气仅用于生产乙炔,发展高附加值的BDO及其下游产品,其余合成气均由煤集中造气获得,作为甲醇、醋酐(联产醋酸)、乙二醇、乙醇等产品的原料。本方案可以让川维厂实现原材料资源配置多元化,增加高附加值产品,改善产

  18. 静态顶空气质联用法测定霞多丽在酒精发酵过程中香气的变化%Determination of aromatic components in chardonnay alcoholic fermentation by static headspace-GC-MS

    Institute of Scientific and Technical Information of China (English)

    范爱月; 苑伟; 张会宁; 薛晓燕; 祁新春; 缪成鹏

    2012-01-01

    The chardonnay aromatic compounds were analyzed every 12h during the alcoholic fermentation by static headspace-GC-MS. Their relative contents were determined by area normalization. 31 components were identified in the whole of alcoholic fermentation, including 11 alcohols, 13 esters and 7 other substances (acids, aldehydes and ketones). Aromatic components were different in before and after fermentation. The relative contents and variety of alcohols and esters increased gradually and other substances (acids, aldehydes and ketones) reduced. The main aromatic components were ethanol; 1-propanol, 2-methy-1; 1-butanol, 3-methy1-; 2, 3-butanediol; phenylethyl alcohol; 1-propanol; 1-hexanol; ethyl acetate; octanoic acid, ethyl ester; ethyl pelargonate; acetic acid, 2-phenylethyl ester; dodecanoic acid, ethyl ester; acetic acid, hexyl ester; acetic acid, 2-methylpropyl ester; 1-butanol, 3-methyl-acetate; hexanoic acid,ethyl ester and acetic acid.%运用静态顶空-气相色谱质谱联用法,从霞多丽葡萄汁到酒精发酵结束,每隔12h对其香气成分进行检测.检测得到的香气成分通过质谱谱库进行定性,色谱峰面积归一化法进行定量.测定结果显示:霞多丽在酒精发酵过程中共检测出31中香气物质,其中醇类物质有11种,酯类物质有13种,其他物质(酸、醛、酮)有7种.发酵前后香气成分的种类和相对含量变化显著.其中酯类和醇类物质的种类和相对含量随着发酵的进行有所增加,而其他类(酸、醛、酮)物质的种类和相对含量随着发酵的进行急剧下降.发酵结束后,发酵液的主要香气成分为:乙醇、2-甲基丙醇、3-甲基丁醇、2,3-丁二醇、苯乙醇、正丙醇、己醇、乙酸己酯、辛酸乙酯、壬酸乙酯、2-苯基乙酸乙酯、十二酸乙酯、乙酸乙酯、2-甲基乙酸丙酯、3-甲基乙酸丁酯、己酸乙酯、乙酸.

  19. 纳米纤维素气凝胶的制备、表征及其性能研究%Preparation and Shape Recovery Property of the Nanocellulose Aerogels

    Institute of Scientific and Technical Information of China (English)

    王蒙蒙; 王爱婷; 刘鹤; 刘仕伟; 于世涛

    2016-01-01

    以纳米纤维素纤丝( NCFs)为原料,在四氯化锡的催化下与1,4-丁二醇二缩水甘油醚( BDGE)发生交联反应制备了多孔的纳米纤维素气凝胶,采用扫描电镜、傅里叶变换红外光谱仪、X射线衍射仪、热重分析仪、X射线光电子能谱和全自动比表面积及物理吸附分析仪,对制备的纳米纤维素气凝胶的微观形貌、化学结构、晶型结构、热稳定性、表面元素及比表面积进行了表征,考察了纳米纤维素气凝胶的密度、溶剂吸收、形状恢复以及重复使用性能。结果表明:NCFs与BDGE发生了交联反应,制备的纳米纤维素气凝胶具有连续的多孔网络结构,其仍保持原来的纤维素I型结构,初始分解温度在300℃以上,m( BDGE)∶m( NCFs)为2∶1时,制备的气凝胶密度为0.0202 mg/cm3,比表面积为25.6 m2/g,吸水倍数为36.5 g/g。气凝胶在水中5 s能迅速恢复其原来形状,在DMSO中20 s能恢复形状的90%,气凝胶重复使用5次,吸水倍数仍高达30.4 g/g。%The porous nanocellulose aerogels were obtained by the cross-linked reaction of 1, 4-butanediol diglycidyl ether (BDGE) and nanocellulose fibers (NCFs) with the catalyst of SnCl4. The morphological feature, chemical characterization, crystal structure, thermostability, element of nanocellulose aerogels and surface aera were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermo gravimetric analysis, scanning electron microscopy, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller analysis, respectively. The density, solvent absorption ability, shape recovery property and reusability of nanocellulose aerogels were investigated. The results showed that aerogels with continuous network pore structure still maintain the cellulose I crystalline structure and the aerogels started to degrade above 300 ℃. When the amount of BDGE was 2 times as much as the mass of NCFs, the density of aerogels was 0. 020 2 mg/cm3 , and

  20. 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 .

  1. Effect of mixed chain extenders on the macroscopic properties of polyurethane elastomers%混合扩链剂对聚氨酯弹性体宏观性能的影响

    Institute of Scientific and Technical Information of China (English)

    罗建勋; 靳昊; 毛立新; 张立群

    2011-01-01

    A series of polyurethane elastomers have been synthesized from prepolymers ( component A) and chain extenders (component B). The prepolymers were prepared using 4,4'-diphenylmethane diisocyanate (MDI) and polytetrahydrofuran polyols (PTMG). The chain extenders were mixtures of trihydroxy polyether polyols (330N) with 1 ,4-butanediol (BDO) or ethylene glycol (EGO). The thermal and mechanical properties of polyurethane e-lastomers based on two different systems (330N/BDO and 330N/EGO) for a range of different mass ratios in each system were investigated. Differential scanning calorimetry (DSC) showed that the glass transition temperature of soft segments (Tgs) was lower in the 330N/BDO systems, whilst the melting heat of hard segments was higher in the 330N/BDO systems. The values of Tgs and the melting heat of hard segments increased with the decreasing 330N: BDO and 330N: EGO mass ratios. Measurements of mechanical properties and dynamic mechanical thermal analysis (DMTA) showed that tensile strength and the hardness were higher for the 330N/EGO system, while the elongation and hysteresis loss (tanδ) were lower. With decreasing 330N: BDO and 330N: EGO mass ratios, the tensile strength and hardness increased, but elongation and hysteresis loss (tanδ) decreased.%以4,4 -二苯基甲烷二异氰酸酯(MDI)和聚四氢呋喃均聚醚(PTMG)为原料合成聚氨酯(PU)预聚体(A组分),三羟基聚醚多元醇(330N)分别与1,4-丁二醇(BDO)或乙二醇(EGO)混合作为扩链剂(B组分),将A、B组分聚合制备PU弹性体.探讨330N/BDO与330N/EGO不同体系以及各体系不同质量比对PU弹性体热性能和机械性能的影响.结果表明,330N/BDO体系的软段玻璃化转变温度(Tgs)较低,硬段熔融热较高,随着330N/BDO质量比的下降,Tgs上升,硬段熔融热增加;330N/EGO体系的拉伸强度、硬度稍高,而断裂伸长率和滞后损失(tarδ)有较大落差,随着330N/EGO质量比的下降,弹性体的拉伸强度和硬度增加,

  2. Synthesis of Palm Acide Polyol Esters Catalyzed by Acidic Ionic Liquid%酸性离子液体催化合成棕榈油酸多元醇酯

    Institute of Scientific and Technical Information of China (English)

    牛玉莲; 邢宝妹; 陆杨; 李在均; 刘俊康; 黄路

    2011-01-01

    将5种酸性离子液体分别应用于棕榈油酸多元醇酯的合成反应,结果发现硫酸三乙基铵离子液体催化活性最大.利用硫酸三乙基铵盐的温控特点,设计出一种“高温反应”和“低温分离”相结合的棕榈油酸多元醇酯的合成方法,得到了合成棕榈油酸季戊四醇酯的最佳反应条件:油酸与季戊四醇的物质的量比为6:1,离子液体质量分数为5%,210℃的反应温度和3.5h的反应时间.在相应的最佳条件下,棕榈油酸季戊四醇酯、棕榈油酸三羟甲基丙烷酯、棕榈油酸二羟甲基新戊烷酯、棕榈油酸山梨醇酯和棕榈油酸1,3-丁二醇酯的转化率分别达94.6%,94.5%,97.0%,98.5%和99.2%.反应完成后,离子液体沉淀析出,可直接用于下一次的合成反应.对5种酯化产品理化性质的研究结果表明,棕榈油酸多元醇酯具有良好的流动及低温特性,其黏度指数和倾点范围分别在184~388和- 23~-40℃之间,可作为生物润滑剂基础油.%Five acidic ionic liquids were investigated to synthesize palm acide polyol esters, the results indicated triethylammonium sulfate offers best catalytic activity. Based on temperature-controlled characteristics of triethylammonium sulfate, we designed a novel method for preparation of palm acide polyol esters, in which the reaction under relatively high temperature combined with the separation of the ionic liquid under relatively low temperature. The optimal conditions to produce palm acide pentaerythritol esters were obtained, these include a6'l of palm acide/pentaerythritol, 5% of the ionic liquid, 210 ℃ of the reaction temperature and 3.5 h of reaction time. Under corresponding optimal conditions, five palm acide pentaerythritol esters, which includes palm acide pentaerythritol ester, palm acide trimethylolpropane ester, palm acide dihydroxymethylneopentane ester, palm acide sorbitol ester and palm acide 1,3-butanediol ester, were synthesized in the

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Study on influence factors of the flux for strong cation-exchange monolithic electroosmotic pump%强阳离子交换整体电渗泵流量影响因素研究

    Institute of Scientific and Technical Information of China (English)

    崔瑞红; 尤慧艳

    2011-01-01

    采用丙烯酸,2-丙烯酰胺-2-甲基丙磺酸为功能单体,N,N’-亚甲基双丙烯酰胺为交联剂,正十二醇、1,4-丁二醇及二甲基亚砜为致孔剂,偶氮二异丁腈为引发剂在原位聚合,制备出了以丙烯酰胺类强阳离子交换整体柱为核心的电渗泵.在乙腈-磷酸盐二元流动相体系下,考察了驱动电压,有机调节剂,盐浓度,pH对该泵流量的影响.流量与驱动电压呈线性关系(0.9991);当有机调节剂乙腈的浓度低于70%时,固定相溶胀为主要因素,流量随乙腈浓度的增加而有下降的趋势,但随着有机调节剂浓度的增加(>70%),此时粘度起主要作用,流量开始缓慢地增加;随着磷酸盐浓度逐渐增加,流量随之降低;在pH 3~9范围内,流量基本上保持恒定.%A strong cation-exchange monolithic electroosmotic column was prepared inside the fused-silica capillary bypolymerization. The solution was consisted of acrylanide, 2-acrylamido-2-methyl-l -propanesulfonicacid as a functional monomer, N, N' -methylenebisacrylanide as a cross-linking agent, dimethyl sulphoxide and dodecanol, 1, 4-Butanediol as organic porogenic reagents and azobisisobutyronitrile as an initiator. The monolithic column was severed as a key part of electroosmotic pump. Effects of applied voltage, the concentrations of organic modifier and salt solution, pH value on the flux were investigated. A good linear relationship between the applied voltage and the flux was obtained (0. 9991 ). The concentration of the organic modifier (CAN)was less than 70%. The swelling degree of stationary phase played a main role, and the flux decreased with increase of the concentration of CAN. However, its concentration was more than 70% , at this time the viscosity of mobile phase was the main influence factor, the flux began to increase slightly. The flux decreased as the concentration of phosphate increased. pH value was in the range of 3 ~ 9, it did not exert a significant change in

  10. Preparation of strong cation-exchange monolithic column and its application in polypeptide separation by capillary electrochromatography%强阳离子交换整体柱的研制及其在电色谱多肽分离中的应用

    Institute of Scientific and Technical Information of China (English)

    齐楠; 崔瑞红; 尤慧艳

    2011-01-01

    以丙烯酸、2-丙烯酰胺-2-甲基丙磺酸为功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,正十二醇、1,4-丁二醇及二甲基亚砜为致孔剂,偶氮二异丁腈为引发剂,原位聚合制备了丙烯酰胺类强阳离子交换整体柱.考察了驱动电压、有机调节剂、盐浓度、pH值等对电渗流的影响.结果表明,电渗流与驱动电压的线性关系良好,相关系数为0.998 1;有机调节剂乙腈对电渗流的影响除与流动相的黏度有关外,还与同定相的溶胀有关,当浓度低时,电渗流随乙腈浓度的增加有反常的下降趋势;随着磷酸盐浓度逐渐增加,电渗流降低,与理论相符;在pH值为3~9范围内,电渗流基本上保持恒定,体现了整体柱使用酸碱范围宽的优越性.在优化的实验条件下,采用毛细管电色谱法在此整体柱上成功分离了5种多肽,体现了该类整体柱在多肽分离研究中的优势,为进一步将其应用于蛋白质分离研究打下了基础.%A strong cation-exchange monolithic column was prepared by polymerization inside the fused-silica capillary. The solution consisted of acrylic acid and 2-acrylamido-2-methyl-l-propanesulfonic acid as functional monomers, 7V,AT'-methyIenebisacrylamide as a cross-linking agent, dimethyl sulphoxide and dodecanol, 1,4-butanediol as organic porogenic solvents and azobisisobutyronitrile as a suitable initiator. The effects of the applied voltage, concentrations of organic modifier and salt solution, pH value on the electroosmotic flow were investigated. The experimental results showed that there existed a good linear relationship between the applied voltage and electroosmotic flow with a correlation coefficient of 0. 998 1 ; When the concentration of organic modifier (acetonitrile, CAN) was less than 70% , the swelling degree of stationary phase played a main role and the electroosmotic flow was decreased abnormally with the increase of CAN concentration; The electroosmotic flow

  11. Effects of Soft Segments with Different Structures on Properties of PUR-T%不同软段结构对PUR-T性能影响研究

    Institute of Scientific and Technical Information of China (English)

    张敏; 路润峰; 王昊; 顾利民

    2014-01-01

    采用4,4′-二苯基甲烷二异氰酸酯为硬段,聚ε-己内酯、聚四氢呋喃醚二醇、聚乙二醇为软段,1,4-丁二醇为扩链剂合成了不同软段结构的热塑性聚氨酯弹性体(PUR-T),并用傅立叶变换红外光谱仪对其结构进行了表征,讨论了不同软段结构、不同软段分子量、不同软段浓度等因素对PUR-T力学性能和热性能的影响。结果表明,合成的PUR-T即为本研究的目标产物;PUR-T软段分子量越小其力学性能越优异,但对其热稳定性影响不大;软段结构对PUR-T的性能影响显著,其中聚酯型PUR-T的力学性能优于聚醚型PUR-T,但热稳定性较聚醚型PUR-T差;随着软段浓度的增加,PUR-T的拉伸强度和撕裂强度都呈先提高后降低的趋势,当软段浓度为60%时达到最高, PUR-T的热稳定性随软段浓度的增加而升高。%Different structures of thermoplastic polyurethane elastomer(PUR-T) was synthesized with 4,4′-diphenyl methane diisocyanate as hard segment,poly(ε-caprolactone),polyethylene tetrahydrofuran ether glycol,polyethylene glycol as soft segments,1,4-butanediol as chain extender.The structures were characterized by Fourier transform infrared spectrometer.The influences of soft segment structure,molecular weight and concentration on PUR-T mechanical properties and heat resistance were discussed.The results showed that the prepared PUR-T was the target product in this experiment.The lower the molecular weight of PUR-T soft segment,the more excellent the mechanical properties,but the effect on its thermal stability was little.The effect of soft segment structure on PUR-T performance was remarkable.The mechanical properties of polyester PUR-T type were better than those of polyether PUR-T type.While the thermal stability of polyether type PUR-T was better.With the increase of the concentration of soft segment,the tensile strength and tear strength increased first and then decreased,and they

  12. Synthesis and Properties of Hyperbranched Polyesters with Diol as a Core Monomer%二元醇为核单体的超支化聚酯的合成与性能

    Institute of Scientific and Technical Information of China (English)

    王勇; 朱延安; 孔霞; 瞿金清

    2013-01-01

      分别以乙基丁基丙二醇(BEPD)、1,4-丁二醇(BDO)和新戊二醇(NPG)为核单体,二羟甲基丙酸为AB2型单体,对甲苯磺酸为催化剂,采用准一步法合成了第三代超支化聚酯(HBP-1、HBP-2和HBP-3)。采用FT-IR、1H-NMR和GPC对其结构和分子量进行表征并测定了超支化聚酯的特性黏度。以甲苯二异氰酸酯加成物为固化剂,研究了超支化聚酯的固化涂膜性能,使用热重分析仪(TGA)考察了超支化聚酯涂膜的热稳定性能。结果表明,三种核单体成功合成了超支化聚酯,以BEPD为核单体的超支化聚酯HBP-1具有最高的支化度达到0.55。GPC测得的分子量与理论分子量接近,且以BEPD为核的HBP-1分子量分布最低为1.68。超支化聚酯在极性溶剂中有较好的溶解性能,在非极性溶剂中不溶,其中HBP-1具有更好的溶解性能和较低的特性黏度(4.24 mL⋅g−1)。超支化聚酯的固化涂膜具有较好的热稳定性、优异的附着力、柔韧性和较高的硬度。%  The third generation hyperbranched polyesters (HBPs) were synthesized by the pseudo-one step method with 2,2-bis(hydroxyl-methyl) propionic acid as AB2 monomer, p-toluene sulfonic acid as catalyst, in which 2-butyl-2-ethyl-1,3-propanediol (BEPD, HBP-1), 1,4-butanediol (BDO, HBP-2), and neopentyl glycol (NPG, HBP-3) were used as the core monomers, respectively. The structures and molecular weights of HBPs were characterized with FT-IR, NMR and GPC as well as their intrinsic viscosities were also given. The film properties of HBPs cured by the toluene diisocyanate adduct were tested. The thermal stability of cured HBPs films were also examined by thermogravimetric analysis (TGA). It was found that HBPs are successfully synthesized and HBP-1 displays the highest branching degree up to 0.55. The GPC measured molecular weights of HBPs approach to the theoretical values, and HBP-1 exhibits the lowest polydispersity index up to 1

  13. 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

  14. 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

  15. 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

  16. Synthesis and Application of Sodium 1,4 - Dihydroxybutane - 2 - Sulfonate in Synthesis of Polyurethane Ionomer Containing Sulfonate%1,4-二羟基丁烷-2-磺酸钠的合成及其在聚氨酯离子聚合物合成中的应用

    Institute of Scientific and Technical Information of China (English)

    黄书; 孙东成

    2012-01-01

    ionomer was synthesized by using poly ( hexamethylene neopentylene adipate) ( PHNA) ,isophorone diisocyanate ( IPDI) ,ethylene dimine(EDA) ,1,4- butanediol(BDO) and sodium 1,4- dihydroxybutane -2 - sulfonate which was used as a monomer containing ions by the acetone process. The structure of the polyurethane ionomer was confirmed by FT - IR. The results of tensile tests showed that the elongation strength of the polyurethane ionomer was 41. 3 MPa and the ultimate elongation was 1 700% . The primary properties of the polyurethane dispersion were tested. The results showed that the zeta potential of the polyurethane dispersion was -53. 85 mV and solid content was 50. 6% with the viscosity of 320 mPa · s and excellent stabilization. The polyurethane dispersion was featured by its high solid content and low viscosity.

  17. 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